Commit | Line | Data |
---|---|---|
0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
375637bc AS |
47 | #include <linux/namei.h> |
48 | #include <linux/parser.h> | |
e6017571 | 49 | #include <linux/sched/clock.h> |
6e84f315 | 50 | #include <linux/sched/mm.h> |
e4222673 HB |
51 | #include <linux/proc_ns.h> |
52 | #include <linux/mount.h> | |
0793a61d | 53 | |
76369139 FW |
54 | #include "internal.h" |
55 | ||
4e193bd4 TB |
56 | #include <asm/irq_regs.h> |
57 | ||
272325c4 PZ |
58 | typedef int (*remote_function_f)(void *); |
59 | ||
fe4b04fa | 60 | struct remote_function_call { |
e7e7ee2e | 61 | struct task_struct *p; |
272325c4 | 62 | remote_function_f func; |
e7e7ee2e IM |
63 | void *info; |
64 | int ret; | |
fe4b04fa PZ |
65 | }; |
66 | ||
67 | static void remote_function(void *data) | |
68 | { | |
69 | struct remote_function_call *tfc = data; | |
70 | struct task_struct *p = tfc->p; | |
71 | ||
72 | if (p) { | |
0da4cf3e PZ |
73 | /* -EAGAIN */ |
74 | if (task_cpu(p) != smp_processor_id()) | |
75 | return; | |
76 | ||
77 | /* | |
78 | * Now that we're on right CPU with IRQs disabled, we can test | |
79 | * if we hit the right task without races. | |
80 | */ | |
81 | ||
82 | tfc->ret = -ESRCH; /* No such (running) process */ | |
83 | if (p != current) | |
fe4b04fa PZ |
84 | return; |
85 | } | |
86 | ||
87 | tfc->ret = tfc->func(tfc->info); | |
88 | } | |
89 | ||
90 | /** | |
91 | * task_function_call - call a function on the cpu on which a task runs | |
92 | * @p: the task to evaluate | |
93 | * @func: the function to be called | |
94 | * @info: the function call argument | |
95 | * | |
96 | * Calls the function @func when the task is currently running. This might | |
97 | * be on the current CPU, which just calls the function directly | |
98 | * | |
99 | * returns: @func return value, or | |
100 | * -ESRCH - when the process isn't running | |
101 | * -EAGAIN - when the process moved away | |
102 | */ | |
103 | static int | |
272325c4 | 104 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
105 | { |
106 | struct remote_function_call data = { | |
e7e7ee2e IM |
107 | .p = p, |
108 | .func = func, | |
109 | .info = info, | |
0da4cf3e | 110 | .ret = -EAGAIN, |
fe4b04fa | 111 | }; |
0da4cf3e | 112 | int ret; |
fe4b04fa | 113 | |
0da4cf3e PZ |
114 | do { |
115 | ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
116 | if (!ret) | |
117 | ret = data.ret; | |
118 | } while (ret == -EAGAIN); | |
fe4b04fa | 119 | |
0da4cf3e | 120 | return ret; |
fe4b04fa PZ |
121 | } |
122 | ||
123 | /** | |
124 | * cpu_function_call - call a function on the cpu | |
125 | * @func: the function to be called | |
126 | * @info: the function call argument | |
127 | * | |
128 | * Calls the function @func on the remote cpu. | |
129 | * | |
130 | * returns: @func return value or -ENXIO when the cpu is offline | |
131 | */ | |
272325c4 | 132 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
133 | { |
134 | struct remote_function_call data = { | |
e7e7ee2e IM |
135 | .p = NULL, |
136 | .func = func, | |
137 | .info = info, | |
138 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
139 | }; |
140 | ||
141 | smp_call_function_single(cpu, remote_function, &data, 1); | |
142 | ||
143 | return data.ret; | |
144 | } | |
145 | ||
fae3fde6 PZ |
146 | static inline struct perf_cpu_context * |
147 | __get_cpu_context(struct perf_event_context *ctx) | |
148 | { | |
149 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
150 | } | |
151 | ||
152 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
153 | struct perf_event_context *ctx) | |
0017960f | 154 | { |
fae3fde6 PZ |
155 | raw_spin_lock(&cpuctx->ctx.lock); |
156 | if (ctx) | |
157 | raw_spin_lock(&ctx->lock); | |
158 | } | |
159 | ||
160 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
161 | struct perf_event_context *ctx) | |
162 | { | |
163 | if (ctx) | |
164 | raw_spin_unlock(&ctx->lock); | |
165 | raw_spin_unlock(&cpuctx->ctx.lock); | |
166 | } | |
167 | ||
63b6da39 PZ |
168 | #define TASK_TOMBSTONE ((void *)-1L) |
169 | ||
170 | static bool is_kernel_event(struct perf_event *event) | |
171 | { | |
f47c02c0 | 172 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
173 | } |
174 | ||
39a43640 PZ |
175 | /* |
176 | * On task ctx scheduling... | |
177 | * | |
178 | * When !ctx->nr_events a task context will not be scheduled. This means | |
179 | * we can disable the scheduler hooks (for performance) without leaving | |
180 | * pending task ctx state. | |
181 | * | |
182 | * This however results in two special cases: | |
183 | * | |
184 | * - removing the last event from a task ctx; this is relatively straight | |
185 | * forward and is done in __perf_remove_from_context. | |
186 | * | |
187 | * - adding the first event to a task ctx; this is tricky because we cannot | |
188 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
189 | * See perf_install_in_context(). | |
190 | * | |
39a43640 PZ |
191 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. |
192 | */ | |
193 | ||
fae3fde6 PZ |
194 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
195 | struct perf_event_context *, void *); | |
196 | ||
197 | struct event_function_struct { | |
198 | struct perf_event *event; | |
199 | event_f func; | |
200 | void *data; | |
201 | }; | |
202 | ||
203 | static int event_function(void *info) | |
204 | { | |
205 | struct event_function_struct *efs = info; | |
206 | struct perf_event *event = efs->event; | |
0017960f | 207 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
208 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
209 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 210 | int ret = 0; |
fae3fde6 | 211 | |
16444645 | 212 | lockdep_assert_irqs_disabled(); |
fae3fde6 | 213 | |
63b6da39 | 214 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
215 | /* |
216 | * Since we do the IPI call without holding ctx->lock things can have | |
217 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
218 | */ |
219 | if (ctx->task) { | |
63b6da39 | 220 | if (ctx->task != current) { |
0da4cf3e | 221 | ret = -ESRCH; |
63b6da39 PZ |
222 | goto unlock; |
223 | } | |
fae3fde6 | 224 | |
fae3fde6 PZ |
225 | /* |
226 | * We only use event_function_call() on established contexts, | |
227 | * and event_function() is only ever called when active (or | |
228 | * rather, we'll have bailed in task_function_call() or the | |
229 | * above ctx->task != current test), therefore we must have | |
230 | * ctx->is_active here. | |
231 | */ | |
232 | WARN_ON_ONCE(!ctx->is_active); | |
233 | /* | |
234 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
235 | * match. | |
236 | */ | |
63b6da39 PZ |
237 | WARN_ON_ONCE(task_ctx != ctx); |
238 | } else { | |
239 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 240 | } |
63b6da39 | 241 | |
fae3fde6 | 242 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 243 | unlock: |
fae3fde6 PZ |
244 | perf_ctx_unlock(cpuctx, task_ctx); |
245 | ||
63b6da39 | 246 | return ret; |
fae3fde6 PZ |
247 | } |
248 | ||
fae3fde6 | 249 | static void event_function_call(struct perf_event *event, event_f func, void *data) |
0017960f PZ |
250 | { |
251 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 252 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
253 | struct event_function_struct efs = { |
254 | .event = event, | |
255 | .func = func, | |
256 | .data = data, | |
257 | }; | |
0017960f | 258 | |
c97f4736 PZ |
259 | if (!event->parent) { |
260 | /* | |
261 | * If this is a !child event, we must hold ctx::mutex to | |
262 | * stabilize the the event->ctx relation. See | |
263 | * perf_event_ctx_lock(). | |
264 | */ | |
265 | lockdep_assert_held(&ctx->mutex); | |
266 | } | |
0017960f PZ |
267 | |
268 | if (!task) { | |
fae3fde6 | 269 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
270 | return; |
271 | } | |
272 | ||
63b6da39 PZ |
273 | if (task == TASK_TOMBSTONE) |
274 | return; | |
275 | ||
a096309b | 276 | again: |
fae3fde6 | 277 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
278 | return; |
279 | ||
280 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
281 | /* |
282 | * Reload the task pointer, it might have been changed by | |
283 | * a concurrent perf_event_context_sched_out(). | |
284 | */ | |
285 | task = ctx->task; | |
a096309b PZ |
286 | if (task == TASK_TOMBSTONE) { |
287 | raw_spin_unlock_irq(&ctx->lock); | |
288 | return; | |
0017960f | 289 | } |
a096309b PZ |
290 | if (ctx->is_active) { |
291 | raw_spin_unlock_irq(&ctx->lock); | |
292 | goto again; | |
293 | } | |
294 | func(event, NULL, ctx, data); | |
0017960f PZ |
295 | raw_spin_unlock_irq(&ctx->lock); |
296 | } | |
297 | ||
cca20946 PZ |
298 | /* |
299 | * Similar to event_function_call() + event_function(), but hard assumes IRQs | |
300 | * are already disabled and we're on the right CPU. | |
301 | */ | |
302 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
303 | { | |
304 | struct perf_event_context *ctx = event->ctx; | |
305 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
306 | struct task_struct *task = READ_ONCE(ctx->task); | |
307 | struct perf_event_context *task_ctx = NULL; | |
308 | ||
16444645 | 309 | lockdep_assert_irqs_disabled(); |
cca20946 PZ |
310 | |
311 | if (task) { | |
312 | if (task == TASK_TOMBSTONE) | |
313 | return; | |
314 | ||
315 | task_ctx = ctx; | |
316 | } | |
317 | ||
318 | perf_ctx_lock(cpuctx, task_ctx); | |
319 | ||
320 | task = ctx->task; | |
321 | if (task == TASK_TOMBSTONE) | |
322 | goto unlock; | |
323 | ||
324 | if (task) { | |
325 | /* | |
326 | * We must be either inactive or active and the right task, | |
327 | * otherwise we're screwed, since we cannot IPI to somewhere | |
328 | * else. | |
329 | */ | |
330 | if (ctx->is_active) { | |
331 | if (WARN_ON_ONCE(task != current)) | |
332 | goto unlock; | |
333 | ||
334 | if (WARN_ON_ONCE(cpuctx->task_ctx != ctx)) | |
335 | goto unlock; | |
336 | } | |
337 | } else { | |
338 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
339 | } | |
340 | ||
341 | func(event, cpuctx, ctx, data); | |
342 | unlock: | |
343 | perf_ctx_unlock(cpuctx, task_ctx); | |
344 | } | |
345 | ||
e5d1367f SE |
346 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
347 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
348 | PERF_FLAG_PID_CGROUP |\ |
349 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 350 | |
bce38cd5 SE |
351 | /* |
352 | * branch priv levels that need permission checks | |
353 | */ | |
354 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
355 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
356 | PERF_SAMPLE_BRANCH_HV) | |
357 | ||
0b3fcf17 SE |
358 | enum event_type_t { |
359 | EVENT_FLEXIBLE = 0x1, | |
360 | EVENT_PINNED = 0x2, | |
3cbaa590 | 361 | EVENT_TIME = 0x4, |
487f05e1 AS |
362 | /* see ctx_resched() for details */ |
363 | EVENT_CPU = 0x8, | |
0b3fcf17 SE |
364 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
365 | }; | |
366 | ||
e5d1367f SE |
367 | /* |
368 | * perf_sched_events : >0 events exist | |
369 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
370 | */ | |
9107c89e PZ |
371 | |
372 | static void perf_sched_delayed(struct work_struct *work); | |
373 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
374 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
375 | static DEFINE_MUTEX(perf_sched_mutex); | |
376 | static atomic_t perf_sched_count; | |
377 | ||
e5d1367f | 378 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 379 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
f2fb6bef | 380 | static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events); |
e5d1367f | 381 | |
cdd6c482 IM |
382 | static atomic_t nr_mmap_events __read_mostly; |
383 | static atomic_t nr_comm_events __read_mostly; | |
e4222673 | 384 | static atomic_t nr_namespaces_events __read_mostly; |
cdd6c482 | 385 | static atomic_t nr_task_events __read_mostly; |
948b26b6 | 386 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 387 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 388 | |
108b02cf PZ |
389 | static LIST_HEAD(pmus); |
390 | static DEFINE_MUTEX(pmus_lock); | |
391 | static struct srcu_struct pmus_srcu; | |
a63fbed7 | 392 | static cpumask_var_t perf_online_mask; |
108b02cf | 393 | |
0764771d | 394 | /* |
cdd6c482 | 395 | * perf event paranoia level: |
0fbdea19 IM |
396 | * -1 - not paranoid at all |
397 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 398 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 399 | * 2 - disallow kernel profiling for unpriv |
0764771d | 400 | */ |
0161028b | 401 | int sysctl_perf_event_paranoid __read_mostly = 2; |
0764771d | 402 | |
20443384 FW |
403 | /* Minimum for 512 kiB + 1 user control page */ |
404 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
405 | |
406 | /* | |
cdd6c482 | 407 | * max perf event sample rate |
df58ab24 | 408 | */ |
14c63f17 DH |
409 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
410 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
411 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
412 | ||
413 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
414 | ||
415 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
416 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
417 | ||
d9494cb4 PZ |
418 | static int perf_sample_allowed_ns __read_mostly = |
419 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 420 | |
18ab2cd3 | 421 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
422 | { |
423 | u64 tmp = perf_sample_period_ns; | |
424 | ||
425 | tmp *= sysctl_perf_cpu_time_max_percent; | |
91a612ee PZ |
426 | tmp = div_u64(tmp, 100); |
427 | if (!tmp) | |
428 | tmp = 1; | |
429 | ||
430 | WRITE_ONCE(perf_sample_allowed_ns, tmp); | |
14c63f17 | 431 | } |
163ec435 | 432 | |
8d5bce0c | 433 | static bool perf_rotate_context(struct perf_cpu_context *cpuctx); |
9e630205 | 434 | |
163ec435 PZ |
435 | int perf_proc_update_handler(struct ctl_table *table, int write, |
436 | void __user *buffer, size_t *lenp, | |
437 | loff_t *ppos) | |
438 | { | |
723478c8 | 439 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
440 | |
441 | if (ret || !write) | |
442 | return ret; | |
443 | ||
ab7fdefb KL |
444 | /* |
445 | * If throttling is disabled don't allow the write: | |
446 | */ | |
447 | if (sysctl_perf_cpu_time_max_percent == 100 || | |
448 | sysctl_perf_cpu_time_max_percent == 0) | |
449 | return -EINVAL; | |
450 | ||
163ec435 | 451 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); |
14c63f17 DH |
452 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
453 | update_perf_cpu_limits(); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | ||
458 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
459 | ||
460 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
461 | void __user *buffer, size_t *lenp, | |
462 | loff_t *ppos) | |
463 | { | |
1572e45a | 464 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
14c63f17 DH |
465 | |
466 | if (ret || !write) | |
467 | return ret; | |
468 | ||
b303e7c1 PZ |
469 | if (sysctl_perf_cpu_time_max_percent == 100 || |
470 | sysctl_perf_cpu_time_max_percent == 0) { | |
91a612ee PZ |
471 | printk(KERN_WARNING |
472 | "perf: Dynamic interrupt throttling disabled, can hang your system!\n"); | |
473 | WRITE_ONCE(perf_sample_allowed_ns, 0); | |
474 | } else { | |
475 | update_perf_cpu_limits(); | |
476 | } | |
163ec435 PZ |
477 | |
478 | return 0; | |
479 | } | |
1ccd1549 | 480 | |
14c63f17 DH |
481 | /* |
482 | * perf samples are done in some very critical code paths (NMIs). | |
483 | * If they take too much CPU time, the system can lock up and not | |
484 | * get any real work done. This will drop the sample rate when | |
485 | * we detect that events are taking too long. | |
486 | */ | |
487 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 488 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 489 | |
91a612ee PZ |
490 | static u64 __report_avg; |
491 | static u64 __report_allowed; | |
492 | ||
6a02ad66 | 493 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 494 | { |
0d87d7ec | 495 | printk_ratelimited(KERN_INFO |
91a612ee PZ |
496 | "perf: interrupt took too long (%lld > %lld), lowering " |
497 | "kernel.perf_event_max_sample_rate to %d\n", | |
498 | __report_avg, __report_allowed, | |
499 | sysctl_perf_event_sample_rate); | |
6a02ad66 PZ |
500 | } |
501 | ||
502 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
503 | ||
504 | void perf_sample_event_took(u64 sample_len_ns) | |
505 | { | |
91a612ee PZ |
506 | u64 max_len = READ_ONCE(perf_sample_allowed_ns); |
507 | u64 running_len; | |
508 | u64 avg_len; | |
509 | u32 max; | |
14c63f17 | 510 | |
91a612ee | 511 | if (max_len == 0) |
14c63f17 DH |
512 | return; |
513 | ||
91a612ee PZ |
514 | /* Decay the counter by 1 average sample. */ |
515 | running_len = __this_cpu_read(running_sample_length); | |
516 | running_len -= running_len/NR_ACCUMULATED_SAMPLES; | |
517 | running_len += sample_len_ns; | |
518 | __this_cpu_write(running_sample_length, running_len); | |
14c63f17 DH |
519 | |
520 | /* | |
91a612ee PZ |
521 | * Note: this will be biased artifically low until we have |
522 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
14c63f17 DH |
523 | * from having to maintain a count. |
524 | */ | |
91a612ee PZ |
525 | avg_len = running_len/NR_ACCUMULATED_SAMPLES; |
526 | if (avg_len <= max_len) | |
14c63f17 DH |
527 | return; |
528 | ||
91a612ee PZ |
529 | __report_avg = avg_len; |
530 | __report_allowed = max_len; | |
14c63f17 | 531 | |
91a612ee PZ |
532 | /* |
533 | * Compute a throttle threshold 25% below the current duration. | |
534 | */ | |
535 | avg_len += avg_len / 4; | |
536 | max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent; | |
537 | if (avg_len < max) | |
538 | max /= (u32)avg_len; | |
539 | else | |
540 | max = 1; | |
14c63f17 | 541 | |
91a612ee PZ |
542 | WRITE_ONCE(perf_sample_allowed_ns, avg_len); |
543 | WRITE_ONCE(max_samples_per_tick, max); | |
544 | ||
545 | sysctl_perf_event_sample_rate = max * HZ; | |
546 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
6a02ad66 | 547 | |
cd578abb | 548 | if (!irq_work_queue(&perf_duration_work)) { |
91a612ee | 549 | early_printk("perf: interrupt took too long (%lld > %lld), lowering " |
cd578abb | 550 | "kernel.perf_event_max_sample_rate to %d\n", |
91a612ee | 551 | __report_avg, __report_allowed, |
cd578abb PZ |
552 | sysctl_perf_event_sample_rate); |
553 | } | |
14c63f17 DH |
554 | } |
555 | ||
cdd6c482 | 556 | static atomic64_t perf_event_id; |
a96bbc16 | 557 | |
0b3fcf17 SE |
558 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
559 | enum event_type_t event_type); | |
560 | ||
561 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
562 | enum event_type_t event_type, |
563 | struct task_struct *task); | |
564 | ||
565 | static void update_context_time(struct perf_event_context *ctx); | |
566 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 567 | |
cdd6c482 | 568 | void __weak perf_event_print_debug(void) { } |
0793a61d | 569 | |
84c79910 | 570 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 571 | { |
84c79910 | 572 | return "pmu"; |
0793a61d TG |
573 | } |
574 | ||
0b3fcf17 SE |
575 | static inline u64 perf_clock(void) |
576 | { | |
577 | return local_clock(); | |
578 | } | |
579 | ||
34f43927 PZ |
580 | static inline u64 perf_event_clock(struct perf_event *event) |
581 | { | |
582 | return event->clock(); | |
583 | } | |
584 | ||
0d3d73aa PZ |
585 | /* |
586 | * State based event timekeeping... | |
587 | * | |
588 | * The basic idea is to use event->state to determine which (if any) time | |
589 | * fields to increment with the current delta. This means we only need to | |
590 | * update timestamps when we change state or when they are explicitly requested | |
591 | * (read). | |
592 | * | |
593 | * Event groups make things a little more complicated, but not terribly so. The | |
594 | * rules for a group are that if the group leader is OFF the entire group is | |
595 | * OFF, irrespecive of what the group member states are. This results in | |
596 | * __perf_effective_state(). | |
597 | * | |
598 | * A futher ramification is that when a group leader flips between OFF and | |
599 | * !OFF, we need to update all group member times. | |
600 | * | |
601 | * | |
602 | * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we | |
603 | * need to make sure the relevant context time is updated before we try and | |
604 | * update our timestamps. | |
605 | */ | |
606 | ||
607 | static __always_inline enum perf_event_state | |
608 | __perf_effective_state(struct perf_event *event) | |
609 | { | |
610 | struct perf_event *leader = event->group_leader; | |
611 | ||
612 | if (leader->state <= PERF_EVENT_STATE_OFF) | |
613 | return leader->state; | |
614 | ||
615 | return event->state; | |
616 | } | |
617 | ||
618 | static __always_inline void | |
619 | __perf_update_times(struct perf_event *event, u64 now, u64 *enabled, u64 *running) | |
620 | { | |
621 | enum perf_event_state state = __perf_effective_state(event); | |
622 | u64 delta = now - event->tstamp; | |
623 | ||
624 | *enabled = event->total_time_enabled; | |
625 | if (state >= PERF_EVENT_STATE_INACTIVE) | |
626 | *enabled += delta; | |
627 | ||
628 | *running = event->total_time_running; | |
629 | if (state >= PERF_EVENT_STATE_ACTIVE) | |
630 | *running += delta; | |
631 | } | |
632 | ||
633 | static void perf_event_update_time(struct perf_event *event) | |
634 | { | |
635 | u64 now = perf_event_time(event); | |
636 | ||
637 | __perf_update_times(event, now, &event->total_time_enabled, | |
638 | &event->total_time_running); | |
639 | event->tstamp = now; | |
640 | } | |
641 | ||
642 | static void perf_event_update_sibling_time(struct perf_event *leader) | |
643 | { | |
644 | struct perf_event *sibling; | |
645 | ||
edb39592 | 646 | for_each_sibling_event(sibling, leader) |
0d3d73aa PZ |
647 | perf_event_update_time(sibling); |
648 | } | |
649 | ||
650 | static void | |
651 | perf_event_set_state(struct perf_event *event, enum perf_event_state state) | |
652 | { | |
653 | if (event->state == state) | |
654 | return; | |
655 | ||
656 | perf_event_update_time(event); | |
657 | /* | |
658 | * If a group leader gets enabled/disabled all its siblings | |
659 | * are affected too. | |
660 | */ | |
661 | if ((event->state < 0) ^ (state < 0)) | |
662 | perf_event_update_sibling_time(event); | |
663 | ||
664 | WRITE_ONCE(event->state, state); | |
665 | } | |
666 | ||
e5d1367f SE |
667 | #ifdef CONFIG_CGROUP_PERF |
668 | ||
e5d1367f SE |
669 | static inline bool |
670 | perf_cgroup_match(struct perf_event *event) | |
671 | { | |
672 | struct perf_event_context *ctx = event->ctx; | |
673 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
674 | ||
ef824fa1 TH |
675 | /* @event doesn't care about cgroup */ |
676 | if (!event->cgrp) | |
677 | return true; | |
678 | ||
679 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
680 | if (!cpuctx->cgrp) | |
681 | return false; | |
682 | ||
683 | /* | |
684 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
685 | * also enabled for all its descendant cgroups. If @cpuctx's | |
686 | * cgroup is a descendant of @event's (the test covers identity | |
687 | * case), it's a match. | |
688 | */ | |
689 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
690 | event->cgrp->css.cgroup); | |
e5d1367f SE |
691 | } |
692 | ||
e5d1367f SE |
693 | static inline void perf_detach_cgroup(struct perf_event *event) |
694 | { | |
4e2ba650 | 695 | css_put(&event->cgrp->css); |
e5d1367f SE |
696 | event->cgrp = NULL; |
697 | } | |
698 | ||
699 | static inline int is_cgroup_event(struct perf_event *event) | |
700 | { | |
701 | return event->cgrp != NULL; | |
702 | } | |
703 | ||
704 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
705 | { | |
706 | struct perf_cgroup_info *t; | |
707 | ||
708 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
709 | return t->time; | |
710 | } | |
711 | ||
712 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
713 | { | |
714 | struct perf_cgroup_info *info; | |
715 | u64 now; | |
716 | ||
717 | now = perf_clock(); | |
718 | ||
719 | info = this_cpu_ptr(cgrp->info); | |
720 | ||
721 | info->time += now - info->timestamp; | |
722 | info->timestamp = now; | |
723 | } | |
724 | ||
725 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
726 | { | |
c917e0f2 SL |
727 | struct perf_cgroup *cgrp = cpuctx->cgrp; |
728 | struct cgroup_subsys_state *css; | |
729 | ||
730 | if (cgrp) { | |
731 | for (css = &cgrp->css; css; css = css->parent) { | |
732 | cgrp = container_of(css, struct perf_cgroup, css); | |
733 | __update_cgrp_time(cgrp); | |
734 | } | |
735 | } | |
e5d1367f SE |
736 | } |
737 | ||
738 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
739 | { | |
3f7cce3c SE |
740 | struct perf_cgroup *cgrp; |
741 | ||
e5d1367f | 742 | /* |
3f7cce3c SE |
743 | * ensure we access cgroup data only when needed and |
744 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 745 | */ |
3f7cce3c | 746 | if (!is_cgroup_event(event)) |
e5d1367f SE |
747 | return; |
748 | ||
614e4c4e | 749 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
750 | /* |
751 | * Do not update time when cgroup is not active | |
752 | */ | |
e6a52033 | 753 | if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) |
3f7cce3c | 754 | __update_cgrp_time(event->cgrp); |
e5d1367f SE |
755 | } |
756 | ||
757 | static inline void | |
3f7cce3c SE |
758 | perf_cgroup_set_timestamp(struct task_struct *task, |
759 | struct perf_event_context *ctx) | |
e5d1367f SE |
760 | { |
761 | struct perf_cgroup *cgrp; | |
762 | struct perf_cgroup_info *info; | |
c917e0f2 | 763 | struct cgroup_subsys_state *css; |
e5d1367f | 764 | |
3f7cce3c SE |
765 | /* |
766 | * ctx->lock held by caller | |
767 | * ensure we do not access cgroup data | |
768 | * unless we have the cgroup pinned (css_get) | |
769 | */ | |
770 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
771 | return; |
772 | ||
614e4c4e | 773 | cgrp = perf_cgroup_from_task(task, ctx); |
c917e0f2 SL |
774 | |
775 | for (css = &cgrp->css; css; css = css->parent) { | |
776 | cgrp = container_of(css, struct perf_cgroup, css); | |
777 | info = this_cpu_ptr(cgrp->info); | |
778 | info->timestamp = ctx->timestamp; | |
779 | } | |
e5d1367f SE |
780 | } |
781 | ||
058fe1c0 DCC |
782 | static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list); |
783 | ||
e5d1367f SE |
784 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ |
785 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
786 | ||
787 | /* | |
788 | * reschedule events based on the cgroup constraint of task. | |
789 | * | |
790 | * mode SWOUT : schedule out everything | |
791 | * mode SWIN : schedule in based on cgroup for next | |
792 | */ | |
18ab2cd3 | 793 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
794 | { |
795 | struct perf_cpu_context *cpuctx; | |
058fe1c0 | 796 | struct list_head *list; |
e5d1367f SE |
797 | unsigned long flags; |
798 | ||
799 | /* | |
058fe1c0 DCC |
800 | * Disable interrupts and preemption to avoid this CPU's |
801 | * cgrp_cpuctx_entry to change under us. | |
e5d1367f SE |
802 | */ |
803 | local_irq_save(flags); | |
804 | ||
058fe1c0 DCC |
805 | list = this_cpu_ptr(&cgrp_cpuctx_list); |
806 | list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) { | |
807 | WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0); | |
e5d1367f | 808 | |
058fe1c0 DCC |
809 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
810 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f | 811 | |
058fe1c0 DCC |
812 | if (mode & PERF_CGROUP_SWOUT) { |
813 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
814 | /* | |
815 | * must not be done before ctxswout due | |
816 | * to event_filter_match() in event_sched_out() | |
817 | */ | |
818 | cpuctx->cgrp = NULL; | |
819 | } | |
e5d1367f | 820 | |
058fe1c0 DCC |
821 | if (mode & PERF_CGROUP_SWIN) { |
822 | WARN_ON_ONCE(cpuctx->cgrp); | |
823 | /* | |
824 | * set cgrp before ctxsw in to allow | |
825 | * event_filter_match() to not have to pass | |
826 | * task around | |
827 | * we pass the cpuctx->ctx to perf_cgroup_from_task() | |
828 | * because cgorup events are only per-cpu | |
829 | */ | |
830 | cpuctx->cgrp = perf_cgroup_from_task(task, | |
831 | &cpuctx->ctx); | |
832 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); | |
e5d1367f | 833 | } |
058fe1c0 DCC |
834 | perf_pmu_enable(cpuctx->ctx.pmu); |
835 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f SE |
836 | } |
837 | ||
e5d1367f SE |
838 | local_irq_restore(flags); |
839 | } | |
840 | ||
a8d757ef SE |
841 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
842 | struct task_struct *next) | |
e5d1367f | 843 | { |
a8d757ef SE |
844 | struct perf_cgroup *cgrp1; |
845 | struct perf_cgroup *cgrp2 = NULL; | |
846 | ||
ddaaf4e2 | 847 | rcu_read_lock(); |
a8d757ef SE |
848 | /* |
849 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
850 | * we do not need to pass the ctx here because we know |
851 | * we are holding the rcu lock | |
a8d757ef | 852 | */ |
614e4c4e | 853 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 854 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
855 | |
856 | /* | |
857 | * only schedule out current cgroup events if we know | |
858 | * that we are switching to a different cgroup. Otherwise, | |
859 | * do no touch the cgroup events. | |
860 | */ | |
861 | if (cgrp1 != cgrp2) | |
862 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
863 | |
864 | rcu_read_unlock(); | |
e5d1367f SE |
865 | } |
866 | ||
a8d757ef SE |
867 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
868 | struct task_struct *task) | |
e5d1367f | 869 | { |
a8d757ef SE |
870 | struct perf_cgroup *cgrp1; |
871 | struct perf_cgroup *cgrp2 = NULL; | |
872 | ||
ddaaf4e2 | 873 | rcu_read_lock(); |
a8d757ef SE |
874 | /* |
875 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
876 | * we do not need to pass the ctx here because we know |
877 | * we are holding the rcu lock | |
a8d757ef | 878 | */ |
614e4c4e | 879 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 880 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
881 | |
882 | /* | |
883 | * only need to schedule in cgroup events if we are changing | |
884 | * cgroup during ctxsw. Cgroup events were not scheduled | |
885 | * out of ctxsw out if that was not the case. | |
886 | */ | |
887 | if (cgrp1 != cgrp2) | |
888 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
889 | |
890 | rcu_read_unlock(); | |
e5d1367f SE |
891 | } |
892 | ||
893 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
894 | struct perf_event_attr *attr, | |
895 | struct perf_event *group_leader) | |
896 | { | |
897 | struct perf_cgroup *cgrp; | |
898 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
899 | struct fd f = fdget(fd); |
900 | int ret = 0; | |
e5d1367f | 901 | |
2903ff01 | 902 | if (!f.file) |
e5d1367f SE |
903 | return -EBADF; |
904 | ||
b583043e | 905 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 906 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
907 | if (IS_ERR(css)) { |
908 | ret = PTR_ERR(css); | |
909 | goto out; | |
910 | } | |
e5d1367f SE |
911 | |
912 | cgrp = container_of(css, struct perf_cgroup, css); | |
913 | event->cgrp = cgrp; | |
914 | ||
915 | /* | |
916 | * all events in a group must monitor | |
917 | * the same cgroup because a task belongs | |
918 | * to only one perf cgroup at a time | |
919 | */ | |
920 | if (group_leader && group_leader->cgrp != cgrp) { | |
921 | perf_detach_cgroup(event); | |
922 | ret = -EINVAL; | |
e5d1367f | 923 | } |
3db272c0 | 924 | out: |
2903ff01 | 925 | fdput(f); |
e5d1367f SE |
926 | return ret; |
927 | } | |
928 | ||
929 | static inline void | |
930 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
931 | { | |
932 | struct perf_cgroup_info *t; | |
933 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
934 | event->shadow_ctx_time = now - t->timestamp; | |
935 | } | |
936 | ||
db4a8356 DCC |
937 | /* |
938 | * Update cpuctx->cgrp so that it is set when first cgroup event is added and | |
939 | * cleared when last cgroup event is removed. | |
940 | */ | |
941 | static inline void | |
942 | list_update_cgroup_event(struct perf_event *event, | |
943 | struct perf_event_context *ctx, bool add) | |
944 | { | |
945 | struct perf_cpu_context *cpuctx; | |
058fe1c0 | 946 | struct list_head *cpuctx_entry; |
db4a8356 DCC |
947 | |
948 | if (!is_cgroup_event(event)) | |
949 | return; | |
950 | ||
db4a8356 DCC |
951 | /* |
952 | * Because cgroup events are always per-cpu events, | |
953 | * this will always be called from the right CPU. | |
954 | */ | |
955 | cpuctx = __get_cpu_context(ctx); | |
33801b94 | 956 | |
957 | /* | |
958 | * Since setting cpuctx->cgrp is conditional on the current @cgrp | |
959 | * matching the event's cgroup, we must do this for every new event, | |
960 | * because if the first would mismatch, the second would not try again | |
961 | * and we would leave cpuctx->cgrp unset. | |
962 | */ | |
963 | if (add && !cpuctx->cgrp) { | |
be96b316 TH |
964 | struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); |
965 | ||
be96b316 TH |
966 | if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) |
967 | cpuctx->cgrp = cgrp; | |
058fe1c0 | 968 | } |
33801b94 | 969 | |
970 | if (add && ctx->nr_cgroups++) | |
971 | return; | |
972 | else if (!add && --ctx->nr_cgroups) | |
973 | return; | |
974 | ||
975 | /* no cgroup running */ | |
976 | if (!add) | |
977 | cpuctx->cgrp = NULL; | |
978 | ||
979 | cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; | |
980 | if (add) | |
981 | list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); | |
982 | else | |
983 | list_del(cpuctx_entry); | |
db4a8356 DCC |
984 | } |
985 | ||
e5d1367f SE |
986 | #else /* !CONFIG_CGROUP_PERF */ |
987 | ||
988 | static inline bool | |
989 | perf_cgroup_match(struct perf_event *event) | |
990 | { | |
991 | return true; | |
992 | } | |
993 | ||
994 | static inline void perf_detach_cgroup(struct perf_event *event) | |
995 | {} | |
996 | ||
997 | static inline int is_cgroup_event(struct perf_event *event) | |
998 | { | |
999 | return 0; | |
1000 | } | |
1001 | ||
e5d1367f SE |
1002 | static inline void update_cgrp_time_from_event(struct perf_event *event) |
1003 | { | |
1004 | } | |
1005 | ||
1006 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
1007 | { | |
1008 | } | |
1009 | ||
a8d757ef SE |
1010 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
1011 | struct task_struct *next) | |
e5d1367f SE |
1012 | { |
1013 | } | |
1014 | ||
a8d757ef SE |
1015 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
1016 | struct task_struct *task) | |
e5d1367f SE |
1017 | { |
1018 | } | |
1019 | ||
1020 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
1021 | struct perf_event_attr *attr, | |
1022 | struct perf_event *group_leader) | |
1023 | { | |
1024 | return -EINVAL; | |
1025 | } | |
1026 | ||
1027 | static inline void | |
3f7cce3c SE |
1028 | perf_cgroup_set_timestamp(struct task_struct *task, |
1029 | struct perf_event_context *ctx) | |
e5d1367f SE |
1030 | { |
1031 | } | |
1032 | ||
1033 | void | |
1034 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
1035 | { | |
1036 | } | |
1037 | ||
1038 | static inline void | |
1039 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
1040 | { | |
1041 | } | |
1042 | ||
1043 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
1044 | { | |
1045 | return 0; | |
1046 | } | |
1047 | ||
db4a8356 DCC |
1048 | static inline void |
1049 | list_update_cgroup_event(struct perf_event *event, | |
1050 | struct perf_event_context *ctx, bool add) | |
1051 | { | |
1052 | } | |
1053 | ||
e5d1367f SE |
1054 | #endif |
1055 | ||
9e630205 SE |
1056 | /* |
1057 | * set default to be dependent on timer tick just | |
1058 | * like original code | |
1059 | */ | |
1060 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
1061 | /* | |
8a1115ff | 1062 | * function must be called with interrupts disabled |
9e630205 | 1063 | */ |
272325c4 | 1064 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
1065 | { |
1066 | struct perf_cpu_context *cpuctx; | |
8d5bce0c | 1067 | bool rotations; |
9e630205 | 1068 | |
16444645 | 1069 | lockdep_assert_irqs_disabled(); |
9e630205 SE |
1070 | |
1071 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
1072 | rotations = perf_rotate_context(cpuctx); |
1073 | ||
4cfafd30 PZ |
1074 | raw_spin_lock(&cpuctx->hrtimer_lock); |
1075 | if (rotations) | |
9e630205 | 1076 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
1077 | else |
1078 | cpuctx->hrtimer_active = 0; | |
1079 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 1080 | |
4cfafd30 | 1081 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
1082 | } |
1083 | ||
272325c4 | 1084 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 1085 | { |
272325c4 | 1086 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 1087 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 1088 | u64 interval; |
9e630205 SE |
1089 | |
1090 | /* no multiplexing needed for SW PMU */ | |
1091 | if (pmu->task_ctx_nr == perf_sw_context) | |
1092 | return; | |
1093 | ||
62b85639 SE |
1094 | /* |
1095 | * check default is sane, if not set then force to | |
1096 | * default interval (1/tick) | |
1097 | */ | |
272325c4 PZ |
1098 | interval = pmu->hrtimer_interval_ms; |
1099 | if (interval < 1) | |
1100 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 1101 | |
272325c4 | 1102 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 1103 | |
4cfafd30 PZ |
1104 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
1105 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 1106 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
1107 | } |
1108 | ||
272325c4 | 1109 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 1110 | { |
272325c4 | 1111 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 1112 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 1113 | unsigned long flags; |
9e630205 SE |
1114 | |
1115 | /* not for SW PMU */ | |
1116 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 1117 | return 0; |
9e630205 | 1118 | |
4cfafd30 PZ |
1119 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
1120 | if (!cpuctx->hrtimer_active) { | |
1121 | cpuctx->hrtimer_active = 1; | |
1122 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
1123 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
1124 | } | |
1125 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 1126 | |
272325c4 | 1127 | return 0; |
9e630205 SE |
1128 | } |
1129 | ||
33696fc0 | 1130 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 1131 | { |
33696fc0 PZ |
1132 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
1133 | if (!(*count)++) | |
1134 | pmu->pmu_disable(pmu); | |
9e35ad38 | 1135 | } |
9e35ad38 | 1136 | |
33696fc0 | 1137 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 1138 | { |
33696fc0 PZ |
1139 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
1140 | if (!--(*count)) | |
1141 | pmu->pmu_enable(pmu); | |
9e35ad38 | 1142 | } |
9e35ad38 | 1143 | |
2fde4f94 | 1144 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
1145 | |
1146 | /* | |
2fde4f94 MR |
1147 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
1148 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
1149 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
1150 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 1151 | */ |
2fde4f94 | 1152 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 1153 | { |
2fde4f94 | 1154 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 1155 | |
16444645 | 1156 | lockdep_assert_irqs_disabled(); |
b5ab4cd5 | 1157 | |
2fde4f94 MR |
1158 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1159 | ||
1160 | list_add(&ctx->active_ctx_list, head); | |
1161 | } | |
1162 | ||
1163 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1164 | { | |
16444645 | 1165 | lockdep_assert_irqs_disabled(); |
2fde4f94 MR |
1166 | |
1167 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1168 | ||
1169 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1170 | } |
9e35ad38 | 1171 | |
cdd6c482 | 1172 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1173 | { |
e5289d4a | 1174 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1175 | } |
1176 | ||
4af57ef2 YZ |
1177 | static void free_ctx(struct rcu_head *head) |
1178 | { | |
1179 | struct perf_event_context *ctx; | |
1180 | ||
1181 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1182 | kfree(ctx->task_ctx_data); | |
1183 | kfree(ctx); | |
1184 | } | |
1185 | ||
cdd6c482 | 1186 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1187 | { |
564c2b21 PM |
1188 | if (atomic_dec_and_test(&ctx->refcount)) { |
1189 | if (ctx->parent_ctx) | |
1190 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1191 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1192 | put_task_struct(ctx->task); |
4af57ef2 | 1193 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1194 | } |
a63eaf34 PM |
1195 | } |
1196 | ||
f63a8daa PZ |
1197 | /* |
1198 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1199 | * perf_pmu_migrate_context() we need some magic. | |
1200 | * | |
1201 | * Those places that change perf_event::ctx will hold both | |
1202 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1203 | * | |
8b10c5e2 PZ |
1204 | * Lock ordering is by mutex address. There are two other sites where |
1205 | * perf_event_context::mutex nests and those are: | |
1206 | * | |
1207 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1208 | * perf_event_exit_event() |
1209 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1210 | * |
1211 | * - perf_event_init_context() [ parent, 0 ] | |
1212 | * inherit_task_group() | |
1213 | * inherit_group() | |
1214 | * inherit_event() | |
1215 | * perf_event_alloc() | |
1216 | * perf_init_event() | |
1217 | * perf_try_init_event() [ child , 1 ] | |
1218 | * | |
1219 | * While it appears there is an obvious deadlock here -- the parent and child | |
1220 | * nesting levels are inverted between the two. This is in fact safe because | |
1221 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1222 | * spawning task cannot (yet) exit. | |
1223 | * | |
1224 | * But remember that that these are parent<->child context relations, and | |
1225 | * migration does not affect children, therefore these two orderings should not | |
1226 | * interact. | |
f63a8daa PZ |
1227 | * |
1228 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1229 | * because the sys_perf_event_open() case will install a new event and break | |
1230 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1231 | * concerned with cpuctx and that doesn't have children. | |
1232 | * | |
1233 | * The places that change perf_event::ctx will issue: | |
1234 | * | |
1235 | * perf_remove_from_context(); | |
1236 | * synchronize_rcu(); | |
1237 | * perf_install_in_context(); | |
1238 | * | |
1239 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1240 | * quiesce the event, after which we can install it in the new location. This | |
1241 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1242 | * while in transit. Therefore all such accessors should also acquire | |
1243 | * perf_event_context::mutex to serialize against this. | |
1244 | * | |
1245 | * However; because event->ctx can change while we're waiting to acquire | |
1246 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1247 | * function. | |
1248 | * | |
1249 | * Lock order: | |
79c9ce57 | 1250 | * cred_guard_mutex |
f63a8daa PZ |
1251 | * task_struct::perf_event_mutex |
1252 | * perf_event_context::mutex | |
f63a8daa | 1253 | * perf_event::child_mutex; |
07c4a776 | 1254 | * perf_event_context::lock |
f63a8daa PZ |
1255 | * perf_event::mmap_mutex |
1256 | * mmap_sem | |
82d94856 PZ |
1257 | * |
1258 | * cpu_hotplug_lock | |
1259 | * pmus_lock | |
1260 | * cpuctx->mutex / perf_event_context::mutex | |
f63a8daa | 1261 | */ |
a83fe28e PZ |
1262 | static struct perf_event_context * |
1263 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1264 | { |
1265 | struct perf_event_context *ctx; | |
1266 | ||
1267 | again: | |
1268 | rcu_read_lock(); | |
6aa7de05 | 1269 | ctx = READ_ONCE(event->ctx); |
f63a8daa PZ |
1270 | if (!atomic_inc_not_zero(&ctx->refcount)) { |
1271 | rcu_read_unlock(); | |
1272 | goto again; | |
1273 | } | |
1274 | rcu_read_unlock(); | |
1275 | ||
a83fe28e | 1276 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1277 | if (event->ctx != ctx) { |
1278 | mutex_unlock(&ctx->mutex); | |
1279 | put_ctx(ctx); | |
1280 | goto again; | |
1281 | } | |
1282 | ||
1283 | return ctx; | |
1284 | } | |
1285 | ||
a83fe28e PZ |
1286 | static inline struct perf_event_context * |
1287 | perf_event_ctx_lock(struct perf_event *event) | |
1288 | { | |
1289 | return perf_event_ctx_lock_nested(event, 0); | |
1290 | } | |
1291 | ||
f63a8daa PZ |
1292 | static void perf_event_ctx_unlock(struct perf_event *event, |
1293 | struct perf_event_context *ctx) | |
1294 | { | |
1295 | mutex_unlock(&ctx->mutex); | |
1296 | put_ctx(ctx); | |
1297 | } | |
1298 | ||
211de6eb PZ |
1299 | /* |
1300 | * This must be done under the ctx->lock, such as to serialize against | |
1301 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1302 | * calling scheduler related locks and ctx->lock nests inside those. | |
1303 | */ | |
1304 | static __must_check struct perf_event_context * | |
1305 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1306 | { |
211de6eb PZ |
1307 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1308 | ||
1309 | lockdep_assert_held(&ctx->lock); | |
1310 | ||
1311 | if (parent_ctx) | |
71a851b4 | 1312 | ctx->parent_ctx = NULL; |
5a3126d4 | 1313 | ctx->generation++; |
211de6eb PZ |
1314 | |
1315 | return parent_ctx; | |
71a851b4 PZ |
1316 | } |
1317 | ||
1d953111 ON |
1318 | static u32 perf_event_pid_type(struct perf_event *event, struct task_struct *p, |
1319 | enum pid_type type) | |
6844c09d | 1320 | { |
1d953111 | 1321 | u32 nr; |
6844c09d ACM |
1322 | /* |
1323 | * only top level events have the pid namespace they were created in | |
1324 | */ | |
1325 | if (event->parent) | |
1326 | event = event->parent; | |
1327 | ||
1d953111 ON |
1328 | nr = __task_pid_nr_ns(p, type, event->ns); |
1329 | /* avoid -1 if it is idle thread or runs in another ns */ | |
1330 | if (!nr && !pid_alive(p)) | |
1331 | nr = -1; | |
1332 | return nr; | |
6844c09d ACM |
1333 | } |
1334 | ||
1d953111 | 1335 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
6844c09d | 1336 | { |
1d953111 ON |
1337 | return perf_event_pid_type(event, p, __PIDTYPE_TGID); |
1338 | } | |
6844c09d | 1339 | |
1d953111 ON |
1340 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) |
1341 | { | |
1342 | return perf_event_pid_type(event, p, PIDTYPE_PID); | |
6844c09d ACM |
1343 | } |
1344 | ||
7f453c24 | 1345 | /* |
cdd6c482 | 1346 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1347 | * to userspace. |
1348 | */ | |
cdd6c482 | 1349 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1350 | { |
cdd6c482 | 1351 | u64 id = event->id; |
7f453c24 | 1352 | |
cdd6c482 IM |
1353 | if (event->parent) |
1354 | id = event->parent->id; | |
7f453c24 PZ |
1355 | |
1356 | return id; | |
1357 | } | |
1358 | ||
25346b93 | 1359 | /* |
cdd6c482 | 1360 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1361 | * |
25346b93 PM |
1362 | * This has to cope with with the fact that until it is locked, |
1363 | * the context could get moved to another task. | |
1364 | */ | |
cdd6c482 | 1365 | static struct perf_event_context * |
8dc85d54 | 1366 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1367 | { |
cdd6c482 | 1368 | struct perf_event_context *ctx; |
25346b93 | 1369 | |
9ed6060d | 1370 | retry: |
058ebd0e PZ |
1371 | /* |
1372 | * One of the few rules of preemptible RCU is that one cannot do | |
1373 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1374 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1375 | * rcu_read_unlock_special(). |
1376 | * | |
1377 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1378 | * side critical section has interrupts disabled. |
058ebd0e | 1379 | */ |
2fd59077 | 1380 | local_irq_save(*flags); |
058ebd0e | 1381 | rcu_read_lock(); |
8dc85d54 | 1382 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1383 | if (ctx) { |
1384 | /* | |
1385 | * If this context is a clone of another, it might | |
1386 | * get swapped for another underneath us by | |
cdd6c482 | 1387 | * perf_event_task_sched_out, though the |
25346b93 PM |
1388 | * rcu_read_lock() protects us from any context |
1389 | * getting freed. Lock the context and check if it | |
1390 | * got swapped before we could get the lock, and retry | |
1391 | * if so. If we locked the right context, then it | |
1392 | * can't get swapped on us any more. | |
1393 | */ | |
2fd59077 | 1394 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1395 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1396 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1397 | rcu_read_unlock(); |
2fd59077 | 1398 | local_irq_restore(*flags); |
25346b93 PM |
1399 | goto retry; |
1400 | } | |
b49a9e7e | 1401 | |
63b6da39 PZ |
1402 | if (ctx->task == TASK_TOMBSTONE || |
1403 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1404 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1405 | ctx = NULL; |
828b6f0e PZ |
1406 | } else { |
1407 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1408 | } |
25346b93 PM |
1409 | } |
1410 | rcu_read_unlock(); | |
2fd59077 PM |
1411 | if (!ctx) |
1412 | local_irq_restore(*flags); | |
25346b93 PM |
1413 | return ctx; |
1414 | } | |
1415 | ||
1416 | /* | |
1417 | * Get the context for a task and increment its pin_count so it | |
1418 | * can't get swapped to another task. This also increments its | |
1419 | * reference count so that the context can't get freed. | |
1420 | */ | |
8dc85d54 PZ |
1421 | static struct perf_event_context * |
1422 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1423 | { |
cdd6c482 | 1424 | struct perf_event_context *ctx; |
25346b93 PM |
1425 | unsigned long flags; |
1426 | ||
8dc85d54 | 1427 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1428 | if (ctx) { |
1429 | ++ctx->pin_count; | |
e625cce1 | 1430 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1431 | } |
1432 | return ctx; | |
1433 | } | |
1434 | ||
cdd6c482 | 1435 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1436 | { |
1437 | unsigned long flags; | |
1438 | ||
e625cce1 | 1439 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1440 | --ctx->pin_count; |
e625cce1 | 1441 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1442 | } |
1443 | ||
f67218c3 PZ |
1444 | /* |
1445 | * Update the record of the current time in a context. | |
1446 | */ | |
1447 | static void update_context_time(struct perf_event_context *ctx) | |
1448 | { | |
1449 | u64 now = perf_clock(); | |
1450 | ||
1451 | ctx->time += now - ctx->timestamp; | |
1452 | ctx->timestamp = now; | |
1453 | } | |
1454 | ||
4158755d SE |
1455 | static u64 perf_event_time(struct perf_event *event) |
1456 | { | |
1457 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1458 | |
1459 | if (is_cgroup_event(event)) | |
1460 | return perf_cgroup_event_time(event); | |
1461 | ||
4158755d SE |
1462 | return ctx ? ctx->time : 0; |
1463 | } | |
1464 | ||
487f05e1 AS |
1465 | static enum event_type_t get_event_type(struct perf_event *event) |
1466 | { | |
1467 | struct perf_event_context *ctx = event->ctx; | |
1468 | enum event_type_t event_type; | |
1469 | ||
1470 | lockdep_assert_held(&ctx->lock); | |
1471 | ||
3bda69c1 AS |
1472 | /* |
1473 | * It's 'group type', really, because if our group leader is | |
1474 | * pinned, so are we. | |
1475 | */ | |
1476 | if (event->group_leader != event) | |
1477 | event = event->group_leader; | |
1478 | ||
487f05e1 AS |
1479 | event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE; |
1480 | if (!ctx->task) | |
1481 | event_type |= EVENT_CPU; | |
1482 | ||
1483 | return event_type; | |
1484 | } | |
1485 | ||
8e1a2031 | 1486 | /* |
161c85fa | 1487 | * Helper function to initialize event group nodes. |
8e1a2031 | 1488 | */ |
161c85fa | 1489 | static void init_event_group(struct perf_event *event) |
8e1a2031 AB |
1490 | { |
1491 | RB_CLEAR_NODE(&event->group_node); | |
1492 | event->group_index = 0; | |
1493 | } | |
1494 | ||
1495 | /* | |
1496 | * Extract pinned or flexible groups from the context | |
161c85fa | 1497 | * based on event attrs bits. |
8e1a2031 AB |
1498 | */ |
1499 | static struct perf_event_groups * | |
1500 | get_event_groups(struct perf_event *event, struct perf_event_context *ctx) | |
889ff015 FW |
1501 | { |
1502 | if (event->attr.pinned) | |
1503 | return &ctx->pinned_groups; | |
1504 | else | |
1505 | return &ctx->flexible_groups; | |
1506 | } | |
1507 | ||
8e1a2031 | 1508 | /* |
161c85fa | 1509 | * Helper function to initializes perf_event_group trees. |
8e1a2031 | 1510 | */ |
161c85fa | 1511 | static void perf_event_groups_init(struct perf_event_groups *groups) |
8e1a2031 AB |
1512 | { |
1513 | groups->tree = RB_ROOT; | |
1514 | groups->index = 0; | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Compare function for event groups; | |
161c85fa PZ |
1519 | * |
1520 | * Implements complex key that first sorts by CPU and then by virtual index | |
1521 | * which provides ordering when rotating groups for the same CPU. | |
8e1a2031 | 1522 | */ |
161c85fa PZ |
1523 | static bool |
1524 | perf_event_groups_less(struct perf_event *left, struct perf_event *right) | |
8e1a2031 | 1525 | { |
161c85fa PZ |
1526 | if (left->cpu < right->cpu) |
1527 | return true; | |
1528 | if (left->cpu > right->cpu) | |
1529 | return false; | |
1530 | ||
1531 | if (left->group_index < right->group_index) | |
1532 | return true; | |
1533 | if (left->group_index > right->group_index) | |
1534 | return false; | |
1535 | ||
1536 | return false; | |
8e1a2031 AB |
1537 | } |
1538 | ||
1539 | /* | |
161c85fa PZ |
1540 | * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for |
1541 | * key (see perf_event_groups_less). This places it last inside the CPU | |
1542 | * subtree. | |
8e1a2031 AB |
1543 | */ |
1544 | static void | |
1545 | perf_event_groups_insert(struct perf_event_groups *groups, | |
161c85fa | 1546 | struct perf_event *event) |
8e1a2031 AB |
1547 | { |
1548 | struct perf_event *node_event; | |
1549 | struct rb_node *parent; | |
1550 | struct rb_node **node; | |
1551 | ||
1552 | event->group_index = ++groups->index; | |
1553 | ||
1554 | node = &groups->tree.rb_node; | |
1555 | parent = *node; | |
1556 | ||
1557 | while (*node) { | |
1558 | parent = *node; | |
161c85fa | 1559 | node_event = container_of(*node, struct perf_event, group_node); |
8e1a2031 AB |
1560 | |
1561 | if (perf_event_groups_less(event, node_event)) | |
1562 | node = &parent->rb_left; | |
1563 | else | |
1564 | node = &parent->rb_right; | |
1565 | } | |
1566 | ||
1567 | rb_link_node(&event->group_node, parent, node); | |
1568 | rb_insert_color(&event->group_node, &groups->tree); | |
1569 | } | |
1570 | ||
1571 | /* | |
161c85fa | 1572 | * Helper function to insert event into the pinned or flexible groups. |
8e1a2031 AB |
1573 | */ |
1574 | static void | |
1575 | add_event_to_groups(struct perf_event *event, struct perf_event_context *ctx) | |
1576 | { | |
1577 | struct perf_event_groups *groups; | |
1578 | ||
1579 | groups = get_event_groups(event, ctx); | |
1580 | perf_event_groups_insert(groups, event); | |
1581 | } | |
1582 | ||
1583 | /* | |
161c85fa | 1584 | * Delete a group from a tree. |
8e1a2031 AB |
1585 | */ |
1586 | static void | |
1587 | perf_event_groups_delete(struct perf_event_groups *groups, | |
161c85fa | 1588 | struct perf_event *event) |
8e1a2031 | 1589 | { |
161c85fa PZ |
1590 | WARN_ON_ONCE(RB_EMPTY_NODE(&event->group_node) || |
1591 | RB_EMPTY_ROOT(&groups->tree)); | |
8e1a2031 | 1592 | |
161c85fa | 1593 | rb_erase(&event->group_node, &groups->tree); |
8e1a2031 AB |
1594 | init_event_group(event); |
1595 | } | |
1596 | ||
1597 | /* | |
161c85fa | 1598 | * Helper function to delete event from its groups. |
8e1a2031 AB |
1599 | */ |
1600 | static void | |
1601 | del_event_from_groups(struct perf_event *event, struct perf_event_context *ctx) | |
1602 | { | |
1603 | struct perf_event_groups *groups; | |
1604 | ||
1605 | groups = get_event_groups(event, ctx); | |
1606 | perf_event_groups_delete(groups, event); | |
1607 | } | |
1608 | ||
1609 | /* | |
161c85fa | 1610 | * Get the leftmost event in the @cpu subtree. |
8e1a2031 AB |
1611 | */ |
1612 | static struct perf_event * | |
1613 | perf_event_groups_first(struct perf_event_groups *groups, int cpu) | |
1614 | { | |
1615 | struct perf_event *node_event = NULL, *match = NULL; | |
1616 | struct rb_node *node = groups->tree.rb_node; | |
1617 | ||
1618 | while (node) { | |
161c85fa | 1619 | node_event = container_of(node, struct perf_event, group_node); |
8e1a2031 AB |
1620 | |
1621 | if (cpu < node_event->cpu) { | |
1622 | node = node->rb_left; | |
1623 | } else if (cpu > node_event->cpu) { | |
1624 | node = node->rb_right; | |
1625 | } else { | |
1626 | match = node_event; | |
1627 | node = node->rb_left; | |
1628 | } | |
1629 | } | |
1630 | ||
1631 | return match; | |
1632 | } | |
1633 | ||
1cac7b1a PZ |
1634 | /* |
1635 | * Like rb_entry_next_safe() for the @cpu subtree. | |
1636 | */ | |
1637 | static struct perf_event * | |
1638 | perf_event_groups_next(struct perf_event *event) | |
1639 | { | |
1640 | struct perf_event *next; | |
1641 | ||
1642 | next = rb_entry_safe(rb_next(&event->group_node), typeof(*event), group_node); | |
1643 | if (next && next->cpu == event->cpu) | |
1644 | return next; | |
1645 | ||
1646 | return NULL; | |
1647 | } | |
1648 | ||
8e1a2031 | 1649 | /* |
161c85fa | 1650 | * Iterate through the whole groups tree. |
8e1a2031 | 1651 | */ |
6e6804d2 PZ |
1652 | #define perf_event_groups_for_each(event, groups) \ |
1653 | for (event = rb_entry_safe(rb_first(&((groups)->tree)), \ | |
1654 | typeof(*event), group_node); event; \ | |
1655 | event = rb_entry_safe(rb_next(&event->group_node), \ | |
1656 | typeof(*event), group_node)) | |
8e1a2031 | 1657 | |
fccc714b | 1658 | /* |
cdd6c482 | 1659 | * Add a event from the lists for its context. |
fccc714b PZ |
1660 | * Must be called with ctx->mutex and ctx->lock held. |
1661 | */ | |
04289bb9 | 1662 | static void |
cdd6c482 | 1663 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1664 | { |
c994d613 PZ |
1665 | lockdep_assert_held(&ctx->lock); |
1666 | ||
8a49542c PZ |
1667 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1668 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 | 1669 | |
0d3d73aa PZ |
1670 | event->tstamp = perf_event_time(event); |
1671 | ||
04289bb9 | 1672 | /* |
8a49542c PZ |
1673 | * If we're a stand alone event or group leader, we go to the context |
1674 | * list, group events are kept attached to the group so that | |
1675 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1676 | */ |
8a49542c | 1677 | if (event->group_leader == event) { |
4ff6a8de | 1678 | event->group_caps = event->event_caps; |
8e1a2031 | 1679 | add_event_to_groups(event, ctx); |
5c148194 | 1680 | } |
592903cd | 1681 | |
db4a8356 | 1682 | list_update_cgroup_event(event, ctx, true); |
e5d1367f | 1683 | |
cdd6c482 IM |
1684 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1685 | ctx->nr_events++; | |
1686 | if (event->attr.inherit_stat) | |
bfbd3381 | 1687 | ctx->nr_stat++; |
5a3126d4 PZ |
1688 | |
1689 | ctx->generation++; | |
04289bb9 IM |
1690 | } |
1691 | ||
0231bb53 JO |
1692 | /* |
1693 | * Initialize event state based on the perf_event_attr::disabled. | |
1694 | */ | |
1695 | static inline void perf_event__state_init(struct perf_event *event) | |
1696 | { | |
1697 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1698 | PERF_EVENT_STATE_INACTIVE; | |
1699 | } | |
1700 | ||
a723968c | 1701 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1702 | { |
1703 | int entry = sizeof(u64); /* value */ | |
1704 | int size = 0; | |
1705 | int nr = 1; | |
1706 | ||
1707 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1708 | size += sizeof(u64); | |
1709 | ||
1710 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1711 | size += sizeof(u64); | |
1712 | ||
1713 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1714 | entry += sizeof(u64); | |
1715 | ||
1716 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1717 | nr += nr_siblings; |
c320c7b7 ACM |
1718 | size += sizeof(u64); |
1719 | } | |
1720 | ||
1721 | size += entry * nr; | |
1722 | event->read_size = size; | |
1723 | } | |
1724 | ||
a723968c | 1725 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1726 | { |
1727 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1728 | u16 size = 0; |
1729 | ||
c320c7b7 ACM |
1730 | if (sample_type & PERF_SAMPLE_IP) |
1731 | size += sizeof(data->ip); | |
1732 | ||
6844c09d ACM |
1733 | if (sample_type & PERF_SAMPLE_ADDR) |
1734 | size += sizeof(data->addr); | |
1735 | ||
1736 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1737 | size += sizeof(data->period); | |
1738 | ||
c3feedf2 AK |
1739 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1740 | size += sizeof(data->weight); | |
1741 | ||
6844c09d ACM |
1742 | if (sample_type & PERF_SAMPLE_READ) |
1743 | size += event->read_size; | |
1744 | ||
d6be9ad6 SE |
1745 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1746 | size += sizeof(data->data_src.val); | |
1747 | ||
fdfbbd07 AK |
1748 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1749 | size += sizeof(data->txn); | |
1750 | ||
fc7ce9c7 KL |
1751 | if (sample_type & PERF_SAMPLE_PHYS_ADDR) |
1752 | size += sizeof(data->phys_addr); | |
1753 | ||
6844c09d ACM |
1754 | event->header_size = size; |
1755 | } | |
1756 | ||
a723968c PZ |
1757 | /* |
1758 | * Called at perf_event creation and when events are attached/detached from a | |
1759 | * group. | |
1760 | */ | |
1761 | static void perf_event__header_size(struct perf_event *event) | |
1762 | { | |
1763 | __perf_event_read_size(event, | |
1764 | event->group_leader->nr_siblings); | |
1765 | __perf_event_header_size(event, event->attr.sample_type); | |
1766 | } | |
1767 | ||
6844c09d ACM |
1768 | static void perf_event__id_header_size(struct perf_event *event) |
1769 | { | |
1770 | struct perf_sample_data *data; | |
1771 | u64 sample_type = event->attr.sample_type; | |
1772 | u16 size = 0; | |
1773 | ||
c320c7b7 ACM |
1774 | if (sample_type & PERF_SAMPLE_TID) |
1775 | size += sizeof(data->tid_entry); | |
1776 | ||
1777 | if (sample_type & PERF_SAMPLE_TIME) | |
1778 | size += sizeof(data->time); | |
1779 | ||
ff3d527c AH |
1780 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1781 | size += sizeof(data->id); | |
1782 | ||
c320c7b7 ACM |
1783 | if (sample_type & PERF_SAMPLE_ID) |
1784 | size += sizeof(data->id); | |
1785 | ||
1786 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1787 | size += sizeof(data->stream_id); | |
1788 | ||
1789 | if (sample_type & PERF_SAMPLE_CPU) | |
1790 | size += sizeof(data->cpu_entry); | |
1791 | ||
6844c09d | 1792 | event->id_header_size = size; |
c320c7b7 ACM |
1793 | } |
1794 | ||
a723968c PZ |
1795 | static bool perf_event_validate_size(struct perf_event *event) |
1796 | { | |
1797 | /* | |
1798 | * The values computed here will be over-written when we actually | |
1799 | * attach the event. | |
1800 | */ | |
1801 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1802 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1803 | perf_event__id_header_size(event); | |
1804 | ||
1805 | /* | |
1806 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1807 | * Conservative limit to allow for callchains and other variable fields. | |
1808 | */ | |
1809 | if (event->read_size + event->header_size + | |
1810 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1811 | return false; | |
1812 | ||
1813 | return true; | |
1814 | } | |
1815 | ||
8a49542c PZ |
1816 | static void perf_group_attach(struct perf_event *event) |
1817 | { | |
c320c7b7 | 1818 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1819 | |
a76a82a3 PZ |
1820 | lockdep_assert_held(&event->ctx->lock); |
1821 | ||
74c3337c PZ |
1822 | /* |
1823 | * We can have double attach due to group movement in perf_event_open. | |
1824 | */ | |
1825 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1826 | return; | |
1827 | ||
8a49542c PZ |
1828 | event->attach_state |= PERF_ATTACH_GROUP; |
1829 | ||
1830 | if (group_leader == event) | |
1831 | return; | |
1832 | ||
652884fe PZ |
1833 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1834 | ||
4ff6a8de | 1835 | group_leader->group_caps &= event->event_caps; |
8a49542c | 1836 | |
8343aae6 | 1837 | list_add_tail(&event->sibling_list, &group_leader->sibling_list); |
8a49542c | 1838 | group_leader->nr_siblings++; |
c320c7b7 ACM |
1839 | |
1840 | perf_event__header_size(group_leader); | |
1841 | ||
edb39592 | 1842 | for_each_sibling_event(pos, group_leader) |
c320c7b7 | 1843 | perf_event__header_size(pos); |
8a49542c PZ |
1844 | } |
1845 | ||
a63eaf34 | 1846 | /* |
cdd6c482 | 1847 | * Remove a event from the lists for its context. |
fccc714b | 1848 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1849 | */ |
04289bb9 | 1850 | static void |
cdd6c482 | 1851 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1852 | { |
652884fe PZ |
1853 | WARN_ON_ONCE(event->ctx != ctx); |
1854 | lockdep_assert_held(&ctx->lock); | |
1855 | ||
8a49542c PZ |
1856 | /* |
1857 | * We can have double detach due to exit/hot-unplug + close. | |
1858 | */ | |
1859 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1860 | return; |
8a49542c PZ |
1861 | |
1862 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1863 | ||
db4a8356 | 1864 | list_update_cgroup_event(event, ctx, false); |
e5d1367f | 1865 | |
cdd6c482 IM |
1866 | ctx->nr_events--; |
1867 | if (event->attr.inherit_stat) | |
bfbd3381 | 1868 | ctx->nr_stat--; |
8bc20959 | 1869 | |
cdd6c482 | 1870 | list_del_rcu(&event->event_entry); |
04289bb9 | 1871 | |
8a49542c | 1872 | if (event->group_leader == event) |
8e1a2031 | 1873 | del_event_from_groups(event, ctx); |
5c148194 | 1874 | |
b2e74a26 SE |
1875 | /* |
1876 | * If event was in error state, then keep it | |
1877 | * that way, otherwise bogus counts will be | |
1878 | * returned on read(). The only way to get out | |
1879 | * of error state is by explicit re-enabling | |
1880 | * of the event | |
1881 | */ | |
1882 | if (event->state > PERF_EVENT_STATE_OFF) | |
0d3d73aa | 1883 | perf_event_set_state(event, PERF_EVENT_STATE_OFF); |
5a3126d4 PZ |
1884 | |
1885 | ctx->generation++; | |
050735b0 PZ |
1886 | } |
1887 | ||
8a49542c | 1888 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1889 | { |
1890 | struct perf_event *sibling, *tmp; | |
6668128a | 1891 | struct perf_event_context *ctx = event->ctx; |
8a49542c | 1892 | |
6668128a | 1893 | lockdep_assert_held(&ctx->lock); |
a76a82a3 | 1894 | |
8a49542c PZ |
1895 | /* |
1896 | * We can have double detach due to exit/hot-unplug + close. | |
1897 | */ | |
1898 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1899 | return; | |
1900 | ||
1901 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1902 | ||
1903 | /* | |
1904 | * If this is a sibling, remove it from its group. | |
1905 | */ | |
1906 | if (event->group_leader != event) { | |
8343aae6 | 1907 | list_del_init(&event->sibling_list); |
8a49542c | 1908 | event->group_leader->nr_siblings--; |
c320c7b7 | 1909 | goto out; |
8a49542c PZ |
1910 | } |
1911 | ||
04289bb9 | 1912 | /* |
cdd6c482 IM |
1913 | * If this was a group event with sibling events then |
1914 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1915 | * to whatever list we are on. |
04289bb9 | 1916 | */ |
8343aae6 | 1917 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, sibling_list) { |
8e1a2031 | 1918 | |
04289bb9 | 1919 | sibling->group_leader = sibling; |
24868367 | 1920 | list_del_init(&sibling->sibling_list); |
d6f962b5 FW |
1921 | |
1922 | /* Inherit group flags from the previous leader */ | |
4ff6a8de | 1923 | sibling->group_caps = event->group_caps; |
652884fe | 1924 | |
8e1a2031 | 1925 | if (!RB_EMPTY_NODE(&event->group_node)) { |
8e1a2031 | 1926 | add_event_to_groups(sibling, event->ctx); |
6668128a PZ |
1927 | |
1928 | if (sibling->state == PERF_EVENT_STATE_ACTIVE) { | |
1929 | struct list_head *list = sibling->attr.pinned ? | |
1930 | &ctx->pinned_active : &ctx->flexible_active; | |
1931 | ||
1932 | list_add_tail(&sibling->active_list, list); | |
1933 | } | |
8e1a2031 AB |
1934 | } |
1935 | ||
652884fe | 1936 | WARN_ON_ONCE(sibling->ctx != event->ctx); |
04289bb9 | 1937 | } |
c320c7b7 ACM |
1938 | |
1939 | out: | |
1940 | perf_event__header_size(event->group_leader); | |
1941 | ||
edb39592 | 1942 | for_each_sibling_event(tmp, event->group_leader) |
c320c7b7 | 1943 | perf_event__header_size(tmp); |
04289bb9 IM |
1944 | } |
1945 | ||
fadfe7be JO |
1946 | static bool is_orphaned_event(struct perf_event *event) |
1947 | { | |
a69b0ca4 | 1948 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1949 | } |
1950 | ||
2c81a647 | 1951 | static inline int __pmu_filter_match(struct perf_event *event) |
66eb579e MR |
1952 | { |
1953 | struct pmu *pmu = event->pmu; | |
1954 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1955 | } | |
1956 | ||
2c81a647 MR |
1957 | /* |
1958 | * Check whether we should attempt to schedule an event group based on | |
1959 | * PMU-specific filtering. An event group can consist of HW and SW events, | |
1960 | * potentially with a SW leader, so we must check all the filters, to | |
1961 | * determine whether a group is schedulable: | |
1962 | */ | |
1963 | static inline int pmu_filter_match(struct perf_event *event) | |
1964 | { | |
edb39592 | 1965 | struct perf_event *sibling; |
2c81a647 MR |
1966 | |
1967 | if (!__pmu_filter_match(event)) | |
1968 | return 0; | |
1969 | ||
edb39592 PZ |
1970 | for_each_sibling_event(sibling, event) { |
1971 | if (!__pmu_filter_match(sibling)) | |
2c81a647 MR |
1972 | return 0; |
1973 | } | |
1974 | ||
1975 | return 1; | |
1976 | } | |
1977 | ||
fa66f07a SE |
1978 | static inline int |
1979 | event_filter_match(struct perf_event *event) | |
1980 | { | |
0b8f1e2e PZ |
1981 | return (event->cpu == -1 || event->cpu == smp_processor_id()) && |
1982 | perf_cgroup_match(event) && pmu_filter_match(event); | |
fa66f07a SE |
1983 | } |
1984 | ||
9ffcfa6f SE |
1985 | static void |
1986 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1987 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1988 | struct perf_event_context *ctx) |
3b6f9e5c | 1989 | { |
0d3d73aa | 1990 | enum perf_event_state state = PERF_EVENT_STATE_INACTIVE; |
652884fe PZ |
1991 | |
1992 | WARN_ON_ONCE(event->ctx != ctx); | |
1993 | lockdep_assert_held(&ctx->lock); | |
1994 | ||
cdd6c482 | 1995 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1996 | return; |
3b6f9e5c | 1997 | |
6668128a PZ |
1998 | /* |
1999 | * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but | |
2000 | * we can schedule events _OUT_ individually through things like | |
2001 | * __perf_remove_from_context(). | |
2002 | */ | |
2003 | list_del_init(&event->active_list); | |
2004 | ||
44377277 AS |
2005 | perf_pmu_disable(event->pmu); |
2006 | ||
28a967c3 PZ |
2007 | event->pmu->del(event, 0); |
2008 | event->oncpu = -1; | |
0d3d73aa | 2009 | |
cdd6c482 IM |
2010 | if (event->pending_disable) { |
2011 | event->pending_disable = 0; | |
0d3d73aa | 2012 | state = PERF_EVENT_STATE_OFF; |
970892a9 | 2013 | } |
0d3d73aa | 2014 | perf_event_set_state(event, state); |
3b6f9e5c | 2015 | |
cdd6c482 | 2016 | if (!is_software_event(event)) |
3b6f9e5c | 2017 | cpuctx->active_oncpu--; |
2fde4f94 MR |
2018 | if (!--ctx->nr_active) |
2019 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
2020 | if (event->attr.freq && event->attr.sample_freq) |
2021 | ctx->nr_freq--; | |
cdd6c482 | 2022 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 2023 | cpuctx->exclusive = 0; |
44377277 AS |
2024 | |
2025 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
2026 | } |
2027 | ||
d859e29f | 2028 | static void |
cdd6c482 | 2029 | group_sched_out(struct perf_event *group_event, |
d859e29f | 2030 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 2031 | struct perf_event_context *ctx) |
d859e29f | 2032 | { |
cdd6c482 | 2033 | struct perf_event *event; |
0d3d73aa PZ |
2034 | |
2035 | if (group_event->state != PERF_EVENT_STATE_ACTIVE) | |
2036 | return; | |
d859e29f | 2037 | |
3f005e7d MR |
2038 | perf_pmu_disable(ctx->pmu); |
2039 | ||
cdd6c482 | 2040 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
2041 | |
2042 | /* | |
2043 | * Schedule out siblings (if any): | |
2044 | */ | |
edb39592 | 2045 | for_each_sibling_event(event, group_event) |
cdd6c482 | 2046 | event_sched_out(event, cpuctx, ctx); |
d859e29f | 2047 | |
3f005e7d MR |
2048 | perf_pmu_enable(ctx->pmu); |
2049 | ||
0d3d73aa | 2050 | if (group_event->attr.exclusive) |
d859e29f PM |
2051 | cpuctx->exclusive = 0; |
2052 | } | |
2053 | ||
45a0e07a | 2054 | #define DETACH_GROUP 0x01UL |
0017960f | 2055 | |
0793a61d | 2056 | /* |
cdd6c482 | 2057 | * Cross CPU call to remove a performance event |
0793a61d | 2058 | * |
cdd6c482 | 2059 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
2060 | * remove it from the context list. |
2061 | */ | |
fae3fde6 PZ |
2062 | static void |
2063 | __perf_remove_from_context(struct perf_event *event, | |
2064 | struct perf_cpu_context *cpuctx, | |
2065 | struct perf_event_context *ctx, | |
2066 | void *info) | |
0793a61d | 2067 | { |
45a0e07a | 2068 | unsigned long flags = (unsigned long)info; |
0793a61d | 2069 | |
3c5c8711 PZ |
2070 | if (ctx->is_active & EVENT_TIME) { |
2071 | update_context_time(ctx); | |
2072 | update_cgrp_time_from_cpuctx(cpuctx); | |
2073 | } | |
2074 | ||
cdd6c482 | 2075 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 2076 | if (flags & DETACH_GROUP) |
46ce0fe9 | 2077 | perf_group_detach(event); |
cdd6c482 | 2078 | list_del_event(event, ctx); |
39a43640 PZ |
2079 | |
2080 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 2081 | ctx->is_active = 0; |
39a43640 PZ |
2082 | if (ctx->task) { |
2083 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2084 | cpuctx->task_ctx = NULL; | |
2085 | } | |
64ce3126 | 2086 | } |
0793a61d TG |
2087 | } |
2088 | ||
0793a61d | 2089 | /* |
cdd6c482 | 2090 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 2091 | * |
cdd6c482 IM |
2092 | * If event->ctx is a cloned context, callers must make sure that |
2093 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
2094 | * remains valid. This is OK when called from perf_release since |
2095 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 2096 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 2097 | * context has been detached from its task. |
0793a61d | 2098 | */ |
45a0e07a | 2099 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 2100 | { |
a76a82a3 PZ |
2101 | struct perf_event_context *ctx = event->ctx; |
2102 | ||
2103 | lockdep_assert_held(&ctx->mutex); | |
0793a61d | 2104 | |
45a0e07a | 2105 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
a76a82a3 PZ |
2106 | |
2107 | /* | |
2108 | * The above event_function_call() can NO-OP when it hits | |
2109 | * TASK_TOMBSTONE. In that case we must already have been detached | |
2110 | * from the context (by perf_event_exit_event()) but the grouping | |
2111 | * might still be in-tact. | |
2112 | */ | |
2113 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); | |
2114 | if ((flags & DETACH_GROUP) && | |
2115 | (event->attach_state & PERF_ATTACH_GROUP)) { | |
2116 | /* | |
2117 | * Since in that case we cannot possibly be scheduled, simply | |
2118 | * detach now. | |
2119 | */ | |
2120 | raw_spin_lock_irq(&ctx->lock); | |
2121 | perf_group_detach(event); | |
2122 | raw_spin_unlock_irq(&ctx->lock); | |
2123 | } | |
0793a61d TG |
2124 | } |
2125 | ||
d859e29f | 2126 | /* |
cdd6c482 | 2127 | * Cross CPU call to disable a performance event |
d859e29f | 2128 | */ |
fae3fde6 PZ |
2129 | static void __perf_event_disable(struct perf_event *event, |
2130 | struct perf_cpu_context *cpuctx, | |
2131 | struct perf_event_context *ctx, | |
2132 | void *info) | |
7b648018 | 2133 | { |
fae3fde6 PZ |
2134 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
2135 | return; | |
7b648018 | 2136 | |
3c5c8711 PZ |
2137 | if (ctx->is_active & EVENT_TIME) { |
2138 | update_context_time(ctx); | |
2139 | update_cgrp_time_from_event(event); | |
2140 | } | |
2141 | ||
fae3fde6 PZ |
2142 | if (event == event->group_leader) |
2143 | group_sched_out(event, cpuctx, ctx); | |
2144 | else | |
2145 | event_sched_out(event, cpuctx, ctx); | |
0d3d73aa PZ |
2146 | |
2147 | perf_event_set_state(event, PERF_EVENT_STATE_OFF); | |
7b648018 PZ |
2148 | } |
2149 | ||
d859e29f | 2150 | /* |
cdd6c482 | 2151 | * Disable a event. |
c93f7669 | 2152 | * |
cdd6c482 IM |
2153 | * If event->ctx is a cloned context, callers must make sure that |
2154 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2155 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
2156 | * perf_event_for_each_child or perf_event_for_each because they |
2157 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
2158 | * goes to exit will block in perf_event_exit_event(). |
2159 | * | |
cdd6c482 | 2160 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 2161 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 2162 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 2163 | */ |
f63a8daa | 2164 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 2165 | { |
cdd6c482 | 2166 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2167 | |
e625cce1 | 2168 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 2169 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 2170 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 2171 | return; |
53cfbf59 | 2172 | } |
e625cce1 | 2173 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 2174 | |
fae3fde6 PZ |
2175 | event_function_call(event, __perf_event_disable, NULL); |
2176 | } | |
2177 | ||
2178 | void perf_event_disable_local(struct perf_event *event) | |
2179 | { | |
2180 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 2181 | } |
f63a8daa PZ |
2182 | |
2183 | /* | |
2184 | * Strictly speaking kernel users cannot create groups and therefore this | |
2185 | * interface does not need the perf_event_ctx_lock() magic. | |
2186 | */ | |
2187 | void perf_event_disable(struct perf_event *event) | |
2188 | { | |
2189 | struct perf_event_context *ctx; | |
2190 | ||
2191 | ctx = perf_event_ctx_lock(event); | |
2192 | _perf_event_disable(event); | |
2193 | perf_event_ctx_unlock(event, ctx); | |
2194 | } | |
dcfce4a0 | 2195 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 2196 | |
5aab90ce JO |
2197 | void perf_event_disable_inatomic(struct perf_event *event) |
2198 | { | |
2199 | event->pending_disable = 1; | |
2200 | irq_work_queue(&event->pending); | |
2201 | } | |
2202 | ||
e5d1367f | 2203 | static void perf_set_shadow_time(struct perf_event *event, |
0d3d73aa | 2204 | struct perf_event_context *ctx) |
e5d1367f SE |
2205 | { |
2206 | /* | |
2207 | * use the correct time source for the time snapshot | |
2208 | * | |
2209 | * We could get by without this by leveraging the | |
2210 | * fact that to get to this function, the caller | |
2211 | * has most likely already called update_context_time() | |
2212 | * and update_cgrp_time_xx() and thus both timestamp | |
2213 | * are identical (or very close). Given that tstamp is, | |
2214 | * already adjusted for cgroup, we could say that: | |
2215 | * tstamp - ctx->timestamp | |
2216 | * is equivalent to | |
2217 | * tstamp - cgrp->timestamp. | |
2218 | * | |
2219 | * Then, in perf_output_read(), the calculation would | |
2220 | * work with no changes because: | |
2221 | * - event is guaranteed scheduled in | |
2222 | * - no scheduled out in between | |
2223 | * - thus the timestamp would be the same | |
2224 | * | |
2225 | * But this is a bit hairy. | |
2226 | * | |
2227 | * So instead, we have an explicit cgroup call to remain | |
2228 | * within the time time source all along. We believe it | |
2229 | * is cleaner and simpler to understand. | |
2230 | */ | |
2231 | if (is_cgroup_event(event)) | |
0d3d73aa | 2232 | perf_cgroup_set_shadow_time(event, event->tstamp); |
e5d1367f | 2233 | else |
0d3d73aa | 2234 | event->shadow_ctx_time = event->tstamp - ctx->timestamp; |
e5d1367f SE |
2235 | } |
2236 | ||
4fe757dd PZ |
2237 | #define MAX_INTERRUPTS (~0ULL) |
2238 | ||
2239 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 2240 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 2241 | |
235c7fc7 | 2242 | static int |
9ffcfa6f | 2243 | event_sched_in(struct perf_event *event, |
235c7fc7 | 2244 | struct perf_cpu_context *cpuctx, |
6e37738a | 2245 | struct perf_event_context *ctx) |
235c7fc7 | 2246 | { |
44377277 | 2247 | int ret = 0; |
4158755d | 2248 | |
63342411 PZ |
2249 | lockdep_assert_held(&ctx->lock); |
2250 | ||
cdd6c482 | 2251 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
2252 | return 0; |
2253 | ||
95ff4ca2 AS |
2254 | WRITE_ONCE(event->oncpu, smp_processor_id()); |
2255 | /* | |
0c1cbc18 PZ |
2256 | * Order event::oncpu write to happen before the ACTIVE state is |
2257 | * visible. This allows perf_event_{stop,read}() to observe the correct | |
2258 | * ->oncpu if it sees ACTIVE. | |
95ff4ca2 AS |
2259 | */ |
2260 | smp_wmb(); | |
0d3d73aa | 2261 | perf_event_set_state(event, PERF_EVENT_STATE_ACTIVE); |
4fe757dd PZ |
2262 | |
2263 | /* | |
2264 | * Unthrottle events, since we scheduled we might have missed several | |
2265 | * ticks already, also for a heavily scheduling task there is little | |
2266 | * guarantee it'll get a tick in a timely manner. | |
2267 | */ | |
2268 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
2269 | perf_log_throttle(event, 1); | |
2270 | event->hw.interrupts = 0; | |
2271 | } | |
2272 | ||
44377277 AS |
2273 | perf_pmu_disable(event->pmu); |
2274 | ||
0d3d73aa | 2275 | perf_set_shadow_time(event, ctx); |
72f669c0 | 2276 | |
ec0d7729 AS |
2277 | perf_log_itrace_start(event); |
2278 | ||
a4eaf7f1 | 2279 | if (event->pmu->add(event, PERF_EF_START)) { |
0d3d73aa | 2280 | perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); |
cdd6c482 | 2281 | event->oncpu = -1; |
44377277 AS |
2282 | ret = -EAGAIN; |
2283 | goto out; | |
235c7fc7 IM |
2284 | } |
2285 | ||
cdd6c482 | 2286 | if (!is_software_event(event)) |
3b6f9e5c | 2287 | cpuctx->active_oncpu++; |
2fde4f94 MR |
2288 | if (!ctx->nr_active++) |
2289 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
2290 | if (event->attr.freq && event->attr.sample_freq) |
2291 | ctx->nr_freq++; | |
235c7fc7 | 2292 | |
cdd6c482 | 2293 | if (event->attr.exclusive) |
3b6f9e5c PM |
2294 | cpuctx->exclusive = 1; |
2295 | ||
44377277 AS |
2296 | out: |
2297 | perf_pmu_enable(event->pmu); | |
2298 | ||
2299 | return ret; | |
235c7fc7 IM |
2300 | } |
2301 | ||
6751b71e | 2302 | static int |
cdd6c482 | 2303 | group_sched_in(struct perf_event *group_event, |
6751b71e | 2304 | struct perf_cpu_context *cpuctx, |
6e37738a | 2305 | struct perf_event_context *ctx) |
6751b71e | 2306 | { |
6bde9b6c | 2307 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 2308 | struct pmu *pmu = ctx->pmu; |
6751b71e | 2309 | |
cdd6c482 | 2310 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
2311 | return 0; |
2312 | ||
fbbe0701 | 2313 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 2314 | |
9ffcfa6f | 2315 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 2316 | pmu->cancel_txn(pmu); |
272325c4 | 2317 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 2318 | return -EAGAIN; |
90151c35 | 2319 | } |
6751b71e PM |
2320 | |
2321 | /* | |
2322 | * Schedule in siblings as one group (if any): | |
2323 | */ | |
edb39592 | 2324 | for_each_sibling_event(event, group_event) { |
9ffcfa6f | 2325 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 2326 | partial_group = event; |
6751b71e PM |
2327 | goto group_error; |
2328 | } | |
2329 | } | |
2330 | ||
9ffcfa6f | 2331 | if (!pmu->commit_txn(pmu)) |
6e85158c | 2332 | return 0; |
9ffcfa6f | 2333 | |
6751b71e PM |
2334 | group_error: |
2335 | /* | |
2336 | * Groups can be scheduled in as one unit only, so undo any | |
2337 | * partial group before returning: | |
0d3d73aa | 2338 | * The events up to the failed event are scheduled out normally. |
6751b71e | 2339 | */ |
edb39592 | 2340 | for_each_sibling_event(event, group_event) { |
cdd6c482 | 2341 | if (event == partial_group) |
0d3d73aa | 2342 | break; |
d7842da4 | 2343 | |
0d3d73aa | 2344 | event_sched_out(event, cpuctx, ctx); |
6751b71e | 2345 | } |
9ffcfa6f | 2346 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2347 | |
ad5133b7 | 2348 | pmu->cancel_txn(pmu); |
90151c35 | 2349 | |
272325c4 | 2350 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2351 | |
6751b71e PM |
2352 | return -EAGAIN; |
2353 | } | |
2354 | ||
3b6f9e5c | 2355 | /* |
cdd6c482 | 2356 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2357 | */ |
cdd6c482 | 2358 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2359 | struct perf_cpu_context *cpuctx, |
2360 | int can_add_hw) | |
2361 | { | |
2362 | /* | |
cdd6c482 | 2363 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2364 | */ |
4ff6a8de | 2365 | if (event->group_caps & PERF_EV_CAP_SOFTWARE) |
3b6f9e5c PM |
2366 | return 1; |
2367 | /* | |
2368 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2369 | * events can go on. |
3b6f9e5c PM |
2370 | */ |
2371 | if (cpuctx->exclusive) | |
2372 | return 0; | |
2373 | /* | |
2374 | * If this group is exclusive and there are already | |
cdd6c482 | 2375 | * events on the CPU, it can't go on. |
3b6f9e5c | 2376 | */ |
cdd6c482 | 2377 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2378 | return 0; |
2379 | /* | |
2380 | * Otherwise, try to add it if all previous groups were able | |
2381 | * to go on. | |
2382 | */ | |
2383 | return can_add_hw; | |
2384 | } | |
2385 | ||
cdd6c482 IM |
2386 | static void add_event_to_ctx(struct perf_event *event, |
2387 | struct perf_event_context *ctx) | |
53cfbf59 | 2388 | { |
cdd6c482 | 2389 | list_add_event(event, ctx); |
8a49542c | 2390 | perf_group_attach(event); |
53cfbf59 PM |
2391 | } |
2392 | ||
bd2afa49 PZ |
2393 | static void ctx_sched_out(struct perf_event_context *ctx, |
2394 | struct perf_cpu_context *cpuctx, | |
2395 | enum event_type_t event_type); | |
2c29ef0f PZ |
2396 | static void |
2397 | ctx_sched_in(struct perf_event_context *ctx, | |
2398 | struct perf_cpu_context *cpuctx, | |
2399 | enum event_type_t event_type, | |
2400 | struct task_struct *task); | |
fe4b04fa | 2401 | |
bd2afa49 | 2402 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
487f05e1 AS |
2403 | struct perf_event_context *ctx, |
2404 | enum event_type_t event_type) | |
bd2afa49 PZ |
2405 | { |
2406 | if (!cpuctx->task_ctx) | |
2407 | return; | |
2408 | ||
2409 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2410 | return; | |
2411 | ||
487f05e1 | 2412 | ctx_sched_out(ctx, cpuctx, event_type); |
bd2afa49 PZ |
2413 | } |
2414 | ||
dce5855b PZ |
2415 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2416 | struct perf_event_context *ctx, | |
2417 | struct task_struct *task) | |
2418 | { | |
2419 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2420 | if (ctx) | |
2421 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2422 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2423 | if (ctx) | |
2424 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2425 | } | |
2426 | ||
487f05e1 AS |
2427 | /* |
2428 | * We want to maintain the following priority of scheduling: | |
2429 | * - CPU pinned (EVENT_CPU | EVENT_PINNED) | |
2430 | * - task pinned (EVENT_PINNED) | |
2431 | * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE) | |
2432 | * - task flexible (EVENT_FLEXIBLE). | |
2433 | * | |
2434 | * In order to avoid unscheduling and scheduling back in everything every | |
2435 | * time an event is added, only do it for the groups of equal priority and | |
2436 | * below. | |
2437 | * | |
2438 | * This can be called after a batch operation on task events, in which case | |
2439 | * event_type is a bit mask of the types of events involved. For CPU events, | |
2440 | * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE. | |
2441 | */ | |
3e349507 | 2442 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
487f05e1 AS |
2443 | struct perf_event_context *task_ctx, |
2444 | enum event_type_t event_type) | |
0017960f | 2445 | { |
bd903afe | 2446 | enum event_type_t ctx_event_type; |
487f05e1 AS |
2447 | bool cpu_event = !!(event_type & EVENT_CPU); |
2448 | ||
2449 | /* | |
2450 | * If pinned groups are involved, flexible groups also need to be | |
2451 | * scheduled out. | |
2452 | */ | |
2453 | if (event_type & EVENT_PINNED) | |
2454 | event_type |= EVENT_FLEXIBLE; | |
2455 | ||
bd903afe SL |
2456 | ctx_event_type = event_type & EVENT_ALL; |
2457 | ||
3e349507 PZ |
2458 | perf_pmu_disable(cpuctx->ctx.pmu); |
2459 | if (task_ctx) | |
487f05e1 AS |
2460 | task_ctx_sched_out(cpuctx, task_ctx, event_type); |
2461 | ||
2462 | /* | |
2463 | * Decide which cpu ctx groups to schedule out based on the types | |
2464 | * of events that caused rescheduling: | |
2465 | * - EVENT_CPU: schedule out corresponding groups; | |
2466 | * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups; | |
2467 | * - otherwise, do nothing more. | |
2468 | */ | |
2469 | if (cpu_event) | |
2470 | cpu_ctx_sched_out(cpuctx, ctx_event_type); | |
2471 | else if (ctx_event_type & EVENT_PINNED) | |
2472 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2473 | ||
3e349507 PZ |
2474 | perf_event_sched_in(cpuctx, task_ctx, current); |
2475 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2476 | } |
2477 | ||
0793a61d | 2478 | /* |
cdd6c482 | 2479 | * Cross CPU call to install and enable a performance event |
682076ae | 2480 | * |
a096309b PZ |
2481 | * Very similar to remote_function() + event_function() but cannot assume that |
2482 | * things like ctx->is_active and cpuctx->task_ctx are set. | |
0793a61d | 2483 | */ |
fe4b04fa | 2484 | static int __perf_install_in_context(void *info) |
0793a61d | 2485 | { |
a096309b PZ |
2486 | struct perf_event *event = info; |
2487 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2488 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2489 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
63cae12b | 2490 | bool reprogram = true; |
a096309b | 2491 | int ret = 0; |
0793a61d | 2492 | |
63b6da39 | 2493 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2494 | if (ctx->task) { |
b58f6b0d PZ |
2495 | raw_spin_lock(&ctx->lock); |
2496 | task_ctx = ctx; | |
a096309b | 2497 | |
63cae12b | 2498 | reprogram = (ctx->task == current); |
b58f6b0d | 2499 | |
39a43640 | 2500 | /* |
63cae12b PZ |
2501 | * If the task is running, it must be running on this CPU, |
2502 | * otherwise we cannot reprogram things. | |
2503 | * | |
2504 | * If its not running, we don't care, ctx->lock will | |
2505 | * serialize against it becoming runnable. | |
39a43640 | 2506 | */ |
63cae12b PZ |
2507 | if (task_curr(ctx->task) && !reprogram) { |
2508 | ret = -ESRCH; | |
2509 | goto unlock; | |
2510 | } | |
a096309b | 2511 | |
63cae12b | 2512 | WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx); |
63b6da39 PZ |
2513 | } else if (task_ctx) { |
2514 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2515 | } |
b58f6b0d | 2516 | |
33801b94 | 2517 | #ifdef CONFIG_CGROUP_PERF |
2518 | if (is_cgroup_event(event)) { | |
2519 | /* | |
2520 | * If the current cgroup doesn't match the event's | |
2521 | * cgroup, we should not try to schedule it. | |
2522 | */ | |
2523 | struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); | |
2524 | reprogram = cgroup_is_descendant(cgrp->css.cgroup, | |
2525 | event->cgrp->css.cgroup); | |
2526 | } | |
2527 | #endif | |
2528 | ||
63cae12b | 2529 | if (reprogram) { |
a096309b PZ |
2530 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
2531 | add_event_to_ctx(event, ctx); | |
487f05e1 | 2532 | ctx_resched(cpuctx, task_ctx, get_event_type(event)); |
a096309b PZ |
2533 | } else { |
2534 | add_event_to_ctx(event, ctx); | |
2535 | } | |
2536 | ||
63b6da39 | 2537 | unlock: |
2c29ef0f | 2538 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa | 2539 | |
a096309b | 2540 | return ret; |
0793a61d TG |
2541 | } |
2542 | ||
2543 | /* | |
a096309b PZ |
2544 | * Attach a performance event to a context. |
2545 | * | |
2546 | * Very similar to event_function_call, see comment there. | |
0793a61d TG |
2547 | */ |
2548 | static void | |
cdd6c482 IM |
2549 | perf_install_in_context(struct perf_event_context *ctx, |
2550 | struct perf_event *event, | |
0793a61d TG |
2551 | int cpu) |
2552 | { | |
a096309b | 2553 | struct task_struct *task = READ_ONCE(ctx->task); |
39a43640 | 2554 | |
fe4b04fa PZ |
2555 | lockdep_assert_held(&ctx->mutex); |
2556 | ||
0cda4c02 YZ |
2557 | if (event->cpu != -1) |
2558 | event->cpu = cpu; | |
c3f00c70 | 2559 | |
0b8f1e2e PZ |
2560 | /* |
2561 | * Ensures that if we can observe event->ctx, both the event and ctx | |
2562 | * will be 'complete'. See perf_iterate_sb_cpu(). | |
2563 | */ | |
2564 | smp_store_release(&event->ctx, ctx); | |
2565 | ||
a096309b PZ |
2566 | if (!task) { |
2567 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2568 | return; | |
2569 | } | |
2570 | ||
2571 | /* | |
2572 | * Should not happen, we validate the ctx is still alive before calling. | |
2573 | */ | |
2574 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) | |
2575 | return; | |
2576 | ||
39a43640 PZ |
2577 | /* |
2578 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2579 | * to be set in case this is the nr_events 0 -> 1 transition. | |
63cae12b PZ |
2580 | * |
2581 | * Instead we use task_curr(), which tells us if the task is running. | |
2582 | * However, since we use task_curr() outside of rq::lock, we can race | |
2583 | * against the actual state. This means the result can be wrong. | |
2584 | * | |
2585 | * If we get a false positive, we retry, this is harmless. | |
2586 | * | |
2587 | * If we get a false negative, things are complicated. If we are after | |
2588 | * perf_event_context_sched_in() ctx::lock will serialize us, and the | |
2589 | * value must be correct. If we're before, it doesn't matter since | |
2590 | * perf_event_context_sched_in() will program the counter. | |
2591 | * | |
2592 | * However, this hinges on the remote context switch having observed | |
2593 | * our task->perf_event_ctxp[] store, such that it will in fact take | |
2594 | * ctx::lock in perf_event_context_sched_in(). | |
2595 | * | |
2596 | * We do this by task_function_call(), if the IPI fails to hit the task | |
2597 | * we know any future context switch of task must see the | |
2598 | * perf_event_ctpx[] store. | |
39a43640 | 2599 | */ |
63cae12b | 2600 | |
63b6da39 | 2601 | /* |
63cae12b PZ |
2602 | * This smp_mb() orders the task->perf_event_ctxp[] store with the |
2603 | * task_cpu() load, such that if the IPI then does not find the task | |
2604 | * running, a future context switch of that task must observe the | |
2605 | * store. | |
63b6da39 | 2606 | */ |
63cae12b PZ |
2607 | smp_mb(); |
2608 | again: | |
2609 | if (!task_function_call(task, __perf_install_in_context, event)) | |
a096309b PZ |
2610 | return; |
2611 | ||
2612 | raw_spin_lock_irq(&ctx->lock); | |
2613 | task = ctx->task; | |
84c4e620 | 2614 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
a096309b PZ |
2615 | /* |
2616 | * Cannot happen because we already checked above (which also | |
2617 | * cannot happen), and we hold ctx->mutex, which serializes us | |
2618 | * against perf_event_exit_task_context(). | |
2619 | */ | |
63b6da39 PZ |
2620 | raw_spin_unlock_irq(&ctx->lock); |
2621 | return; | |
2622 | } | |
39a43640 | 2623 | /* |
63cae12b PZ |
2624 | * If the task is not running, ctx->lock will avoid it becoming so, |
2625 | * thus we can safely install the event. | |
39a43640 | 2626 | */ |
63cae12b PZ |
2627 | if (task_curr(task)) { |
2628 | raw_spin_unlock_irq(&ctx->lock); | |
2629 | goto again; | |
2630 | } | |
2631 | add_event_to_ctx(event, ctx); | |
2632 | raw_spin_unlock_irq(&ctx->lock); | |
0793a61d TG |
2633 | } |
2634 | ||
d859e29f | 2635 | /* |
cdd6c482 | 2636 | * Cross CPU call to enable a performance event |
d859e29f | 2637 | */ |
fae3fde6 PZ |
2638 | static void __perf_event_enable(struct perf_event *event, |
2639 | struct perf_cpu_context *cpuctx, | |
2640 | struct perf_event_context *ctx, | |
2641 | void *info) | |
04289bb9 | 2642 | { |
cdd6c482 | 2643 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2644 | struct perf_event_context *task_ctx; |
04289bb9 | 2645 | |
6e801e01 PZ |
2646 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2647 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2648 | return; |
3cbed429 | 2649 | |
bd2afa49 PZ |
2650 | if (ctx->is_active) |
2651 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2652 | ||
0d3d73aa | 2653 | perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); |
04289bb9 | 2654 | |
fae3fde6 PZ |
2655 | if (!ctx->is_active) |
2656 | return; | |
2657 | ||
e5d1367f | 2658 | if (!event_filter_match(event)) { |
bd2afa49 | 2659 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); |
fae3fde6 | 2660 | return; |
e5d1367f | 2661 | } |
f4c4176f | 2662 | |
04289bb9 | 2663 | /* |
cdd6c482 | 2664 | * If the event is in a group and isn't the group leader, |
d859e29f | 2665 | * then don't put it on unless the group is on. |
04289bb9 | 2666 | */ |
bd2afa49 PZ |
2667 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) { |
2668 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
fae3fde6 | 2669 | return; |
bd2afa49 | 2670 | } |
fe4b04fa | 2671 | |
fae3fde6 PZ |
2672 | task_ctx = cpuctx->task_ctx; |
2673 | if (ctx->task) | |
2674 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2675 | |
487f05e1 | 2676 | ctx_resched(cpuctx, task_ctx, get_event_type(event)); |
7b648018 PZ |
2677 | } |
2678 | ||
d859e29f | 2679 | /* |
cdd6c482 | 2680 | * Enable a event. |
c93f7669 | 2681 | * |
cdd6c482 IM |
2682 | * If event->ctx is a cloned context, callers must make sure that |
2683 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2684 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2685 | * perf_event_for_each_child or perf_event_for_each as described |
2686 | * for perf_event_disable. | |
d859e29f | 2687 | */ |
f63a8daa | 2688 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2689 | { |
cdd6c482 | 2690 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2691 | |
7b648018 | 2692 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2693 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2694 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2695 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2696 | return; |
2697 | } | |
2698 | ||
d859e29f | 2699 | /* |
cdd6c482 | 2700 | * If the event is in error state, clear that first. |
7b648018 PZ |
2701 | * |
2702 | * That way, if we see the event in error state below, we know that it | |
2703 | * has gone back into error state, as distinct from the task having | |
2704 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2705 | */ |
cdd6c482 IM |
2706 | if (event->state == PERF_EVENT_STATE_ERROR) |
2707 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2708 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2709 | |
fae3fde6 | 2710 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2711 | } |
f63a8daa PZ |
2712 | |
2713 | /* | |
2714 | * See perf_event_disable(); | |
2715 | */ | |
2716 | void perf_event_enable(struct perf_event *event) | |
2717 | { | |
2718 | struct perf_event_context *ctx; | |
2719 | ||
2720 | ctx = perf_event_ctx_lock(event); | |
2721 | _perf_event_enable(event); | |
2722 | perf_event_ctx_unlock(event, ctx); | |
2723 | } | |
dcfce4a0 | 2724 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2725 | |
375637bc AS |
2726 | struct stop_event_data { |
2727 | struct perf_event *event; | |
2728 | unsigned int restart; | |
2729 | }; | |
2730 | ||
95ff4ca2 AS |
2731 | static int __perf_event_stop(void *info) |
2732 | { | |
375637bc AS |
2733 | struct stop_event_data *sd = info; |
2734 | struct perf_event *event = sd->event; | |
95ff4ca2 | 2735 | |
375637bc | 2736 | /* if it's already INACTIVE, do nothing */ |
95ff4ca2 AS |
2737 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) |
2738 | return 0; | |
2739 | ||
2740 | /* matches smp_wmb() in event_sched_in() */ | |
2741 | smp_rmb(); | |
2742 | ||
2743 | /* | |
2744 | * There is a window with interrupts enabled before we get here, | |
2745 | * so we need to check again lest we try to stop another CPU's event. | |
2746 | */ | |
2747 | if (READ_ONCE(event->oncpu) != smp_processor_id()) | |
2748 | return -EAGAIN; | |
2749 | ||
2750 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2751 | ||
375637bc AS |
2752 | /* |
2753 | * May race with the actual stop (through perf_pmu_output_stop()), | |
2754 | * but it is only used for events with AUX ring buffer, and such | |
2755 | * events will refuse to restart because of rb::aux_mmap_count==0, | |
2756 | * see comments in perf_aux_output_begin(). | |
2757 | * | |
2758 | * Since this is happening on a event-local CPU, no trace is lost | |
2759 | * while restarting. | |
2760 | */ | |
2761 | if (sd->restart) | |
c9bbdd48 | 2762 | event->pmu->start(event, 0); |
375637bc | 2763 | |
95ff4ca2 AS |
2764 | return 0; |
2765 | } | |
2766 | ||
767ae086 | 2767 | static int perf_event_stop(struct perf_event *event, int restart) |
375637bc AS |
2768 | { |
2769 | struct stop_event_data sd = { | |
2770 | .event = event, | |
767ae086 | 2771 | .restart = restart, |
375637bc AS |
2772 | }; |
2773 | int ret = 0; | |
2774 | ||
2775 | do { | |
2776 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) | |
2777 | return 0; | |
2778 | ||
2779 | /* matches smp_wmb() in event_sched_in() */ | |
2780 | smp_rmb(); | |
2781 | ||
2782 | /* | |
2783 | * We only want to restart ACTIVE events, so if the event goes | |
2784 | * inactive here (event->oncpu==-1), there's nothing more to do; | |
2785 | * fall through with ret==-ENXIO. | |
2786 | */ | |
2787 | ret = cpu_function_call(READ_ONCE(event->oncpu), | |
2788 | __perf_event_stop, &sd); | |
2789 | } while (ret == -EAGAIN); | |
2790 | ||
2791 | return ret; | |
2792 | } | |
2793 | ||
2794 | /* | |
2795 | * In order to contain the amount of racy and tricky in the address filter | |
2796 | * configuration management, it is a two part process: | |
2797 | * | |
2798 | * (p1) when userspace mappings change as a result of (1) or (2) or (3) below, | |
2799 | * we update the addresses of corresponding vmas in | |
2800 | * event::addr_filters_offs array and bump the event::addr_filters_gen; | |
2801 | * (p2) when an event is scheduled in (pmu::add), it calls | |
2802 | * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync() | |
2803 | * if the generation has changed since the previous call. | |
2804 | * | |
2805 | * If (p1) happens while the event is active, we restart it to force (p2). | |
2806 | * | |
2807 | * (1) perf_addr_filters_apply(): adjusting filters' offsets based on | |
2808 | * pre-existing mappings, called once when new filters arrive via SET_FILTER | |
2809 | * ioctl; | |
2810 | * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly | |
2811 | * registered mapping, called for every new mmap(), with mm::mmap_sem down | |
2812 | * for reading; | |
2813 | * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process | |
2814 | * of exec. | |
2815 | */ | |
2816 | void perf_event_addr_filters_sync(struct perf_event *event) | |
2817 | { | |
2818 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
2819 | ||
2820 | if (!has_addr_filter(event)) | |
2821 | return; | |
2822 | ||
2823 | raw_spin_lock(&ifh->lock); | |
2824 | if (event->addr_filters_gen != event->hw.addr_filters_gen) { | |
2825 | event->pmu->addr_filters_sync(event); | |
2826 | event->hw.addr_filters_gen = event->addr_filters_gen; | |
2827 | } | |
2828 | raw_spin_unlock(&ifh->lock); | |
2829 | } | |
2830 | EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync); | |
2831 | ||
f63a8daa | 2832 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2833 | { |
2023b359 | 2834 | /* |
cdd6c482 | 2835 | * not supported on inherited events |
2023b359 | 2836 | */ |
2e939d1d | 2837 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2838 | return -EINVAL; |
2839 | ||
cdd6c482 | 2840 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2841 | _perf_event_enable(event); |
2023b359 PZ |
2842 | |
2843 | return 0; | |
79f14641 | 2844 | } |
f63a8daa PZ |
2845 | |
2846 | /* | |
2847 | * See perf_event_disable() | |
2848 | */ | |
2849 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2850 | { | |
2851 | struct perf_event_context *ctx; | |
2852 | int ret; | |
2853 | ||
2854 | ctx = perf_event_ctx_lock(event); | |
2855 | ret = _perf_event_refresh(event, refresh); | |
2856 | perf_event_ctx_unlock(event, ctx); | |
2857 | ||
2858 | return ret; | |
2859 | } | |
26ca5c11 | 2860 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2861 | |
32ff77e8 MC |
2862 | static int perf_event_modify_breakpoint(struct perf_event *bp, |
2863 | struct perf_event_attr *attr) | |
2864 | { | |
2865 | int err; | |
2866 | ||
2867 | _perf_event_disable(bp); | |
2868 | ||
2869 | err = modify_user_hw_breakpoint_check(bp, attr, true); | |
2870 | if (err) { | |
2871 | if (!bp->attr.disabled) | |
2872 | _perf_event_enable(bp); | |
2873 | ||
2874 | return err; | |
2875 | } | |
2876 | ||
2877 | if (!attr->disabled) | |
2878 | _perf_event_enable(bp); | |
2879 | return 0; | |
2880 | } | |
2881 | ||
2882 | static int perf_event_modify_attr(struct perf_event *event, | |
2883 | struct perf_event_attr *attr) | |
2884 | { | |
2885 | if (event->attr.type != attr->type) | |
2886 | return -EINVAL; | |
2887 | ||
2888 | switch (event->attr.type) { | |
2889 | case PERF_TYPE_BREAKPOINT: | |
2890 | return perf_event_modify_breakpoint(event, attr); | |
2891 | default: | |
2892 | /* Place holder for future additions. */ | |
2893 | return -EOPNOTSUPP; | |
2894 | } | |
2895 | } | |
2896 | ||
5b0311e1 FW |
2897 | static void ctx_sched_out(struct perf_event_context *ctx, |
2898 | struct perf_cpu_context *cpuctx, | |
2899 | enum event_type_t event_type) | |
235c7fc7 | 2900 | { |
6668128a | 2901 | struct perf_event *event, *tmp; |
db24d33e | 2902 | int is_active = ctx->is_active; |
235c7fc7 | 2903 | |
c994d613 | 2904 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2905 | |
39a43640 PZ |
2906 | if (likely(!ctx->nr_events)) { |
2907 | /* | |
2908 | * See __perf_remove_from_context(). | |
2909 | */ | |
2910 | WARN_ON_ONCE(ctx->is_active); | |
2911 | if (ctx->task) | |
2912 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2913 | return; |
39a43640 PZ |
2914 | } |
2915 | ||
db24d33e | 2916 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2917 | if (!(ctx->is_active & EVENT_ALL)) |
2918 | ctx->is_active = 0; | |
2919 | ||
63e30d3e PZ |
2920 | if (ctx->task) { |
2921 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2922 | if (!ctx->is_active) | |
2923 | cpuctx->task_ctx = NULL; | |
2924 | } | |
facc4307 | 2925 | |
8fdc6539 PZ |
2926 | /* |
2927 | * Always update time if it was set; not only when it changes. | |
2928 | * Otherwise we can 'forget' to update time for any but the last | |
2929 | * context we sched out. For example: | |
2930 | * | |
2931 | * ctx_sched_out(.event_type = EVENT_FLEXIBLE) | |
2932 | * ctx_sched_out(.event_type = EVENT_PINNED) | |
2933 | * | |
2934 | * would only update time for the pinned events. | |
2935 | */ | |
3cbaa590 PZ |
2936 | if (is_active & EVENT_TIME) { |
2937 | /* update (and stop) ctx time */ | |
2938 | update_context_time(ctx); | |
2939 | update_cgrp_time_from_cpuctx(cpuctx); | |
2940 | } | |
2941 | ||
8fdc6539 PZ |
2942 | is_active ^= ctx->is_active; /* changed bits */ |
2943 | ||
3cbaa590 | 2944 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) |
facc4307 | 2945 | return; |
5b0311e1 | 2946 | |
075e0b00 | 2947 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2948 | if (is_active & EVENT_PINNED) { |
6668128a | 2949 | list_for_each_entry_safe(event, tmp, &ctx->pinned_active, active_list) |
889ff015 | 2950 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2951 | } |
889ff015 | 2952 | |
3cbaa590 | 2953 | if (is_active & EVENT_FLEXIBLE) { |
6668128a | 2954 | list_for_each_entry_safe(event, tmp, &ctx->flexible_active, active_list) |
8c9ed8e1 | 2955 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2956 | } |
1b9a644f | 2957 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2958 | } |
2959 | ||
564c2b21 | 2960 | /* |
5a3126d4 PZ |
2961 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2962 | * cloned from the same version of the same context. | |
2963 | * | |
2964 | * Equivalence is measured using a generation number in the context that is | |
2965 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2966 | * and list_del_event(). | |
564c2b21 | 2967 | */ |
cdd6c482 IM |
2968 | static int context_equiv(struct perf_event_context *ctx1, |
2969 | struct perf_event_context *ctx2) | |
564c2b21 | 2970 | { |
211de6eb PZ |
2971 | lockdep_assert_held(&ctx1->lock); |
2972 | lockdep_assert_held(&ctx2->lock); | |
2973 | ||
5a3126d4 PZ |
2974 | /* Pinning disables the swap optimization */ |
2975 | if (ctx1->pin_count || ctx2->pin_count) | |
2976 | return 0; | |
2977 | ||
2978 | /* If ctx1 is the parent of ctx2 */ | |
2979 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2980 | return 1; | |
2981 | ||
2982 | /* If ctx2 is the parent of ctx1 */ | |
2983 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2984 | return 1; | |
2985 | ||
2986 | /* | |
2987 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2988 | * hierarchy, see perf_event_init_context(). | |
2989 | */ | |
2990 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2991 | ctx1->parent_gen == ctx2->parent_gen) | |
2992 | return 1; | |
2993 | ||
2994 | /* Unmatched */ | |
2995 | return 0; | |
564c2b21 PM |
2996 | } |
2997 | ||
cdd6c482 IM |
2998 | static void __perf_event_sync_stat(struct perf_event *event, |
2999 | struct perf_event *next_event) | |
bfbd3381 PZ |
3000 | { |
3001 | u64 value; | |
3002 | ||
cdd6c482 | 3003 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
3004 | return; |
3005 | ||
3006 | /* | |
cdd6c482 | 3007 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
3008 | * because we're in the middle of a context switch and have IRQs |
3009 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 3010 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
3011 | * don't need to use it. |
3012 | */ | |
0d3d73aa | 3013 | if (event->state == PERF_EVENT_STATE_ACTIVE) |
3dbebf15 | 3014 | event->pmu->read(event); |
bfbd3381 | 3015 | |
0d3d73aa | 3016 | perf_event_update_time(event); |
bfbd3381 PZ |
3017 | |
3018 | /* | |
cdd6c482 | 3019 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
3020 | * values when we flip the contexts. |
3021 | */ | |
e7850595 PZ |
3022 | value = local64_read(&next_event->count); |
3023 | value = local64_xchg(&event->count, value); | |
3024 | local64_set(&next_event->count, value); | |
bfbd3381 | 3025 | |
cdd6c482 IM |
3026 | swap(event->total_time_enabled, next_event->total_time_enabled); |
3027 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 3028 | |
bfbd3381 | 3029 | /* |
19d2e755 | 3030 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 3031 | */ |
cdd6c482 IM |
3032 | perf_event_update_userpage(event); |
3033 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
3034 | } |
3035 | ||
cdd6c482 IM |
3036 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
3037 | struct perf_event_context *next_ctx) | |
bfbd3381 | 3038 | { |
cdd6c482 | 3039 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
3040 | |
3041 | if (!ctx->nr_stat) | |
3042 | return; | |
3043 | ||
02ffdbc8 PZ |
3044 | update_context_time(ctx); |
3045 | ||
cdd6c482 IM |
3046 | event = list_first_entry(&ctx->event_list, |
3047 | struct perf_event, event_entry); | |
bfbd3381 | 3048 | |
cdd6c482 IM |
3049 | next_event = list_first_entry(&next_ctx->event_list, |
3050 | struct perf_event, event_entry); | |
bfbd3381 | 3051 | |
cdd6c482 IM |
3052 | while (&event->event_entry != &ctx->event_list && |
3053 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 3054 | |
cdd6c482 | 3055 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 3056 | |
cdd6c482 IM |
3057 | event = list_next_entry(event, event_entry); |
3058 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
3059 | } |
3060 | } | |
3061 | ||
fe4b04fa PZ |
3062 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
3063 | struct task_struct *next) | |
0793a61d | 3064 | { |
8dc85d54 | 3065 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 3066 | struct perf_event_context *next_ctx; |
5a3126d4 | 3067 | struct perf_event_context *parent, *next_parent; |
108b02cf | 3068 | struct perf_cpu_context *cpuctx; |
c93f7669 | 3069 | int do_switch = 1; |
0793a61d | 3070 | |
108b02cf PZ |
3071 | if (likely(!ctx)) |
3072 | return; | |
10989fb2 | 3073 | |
108b02cf PZ |
3074 | cpuctx = __get_cpu_context(ctx); |
3075 | if (!cpuctx->task_ctx) | |
0793a61d TG |
3076 | return; |
3077 | ||
c93f7669 | 3078 | rcu_read_lock(); |
8dc85d54 | 3079 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
3080 | if (!next_ctx) |
3081 | goto unlock; | |
3082 | ||
3083 | parent = rcu_dereference(ctx->parent_ctx); | |
3084 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
3085 | ||
3086 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 3087 | if (!parent && !next_parent) |
5a3126d4 PZ |
3088 | goto unlock; |
3089 | ||
3090 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
3091 | /* |
3092 | * Looks like the two contexts are clones, so we might be | |
3093 | * able to optimize the context switch. We lock both | |
3094 | * contexts and check that they are clones under the | |
3095 | * lock (including re-checking that neither has been | |
3096 | * uncloned in the meantime). It doesn't matter which | |
3097 | * order we take the locks because no other cpu could | |
3098 | * be trying to lock both of these tasks. | |
3099 | */ | |
e625cce1 TG |
3100 | raw_spin_lock(&ctx->lock); |
3101 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 3102 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
3103 | WRITE_ONCE(ctx->task, next); |
3104 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
3105 | |
3106 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
3107 | ||
63b6da39 PZ |
3108 | /* |
3109 | * RCU_INIT_POINTER here is safe because we've not | |
3110 | * modified the ctx and the above modification of | |
3111 | * ctx->task and ctx->task_ctx_data are immaterial | |
3112 | * since those values are always verified under | |
3113 | * ctx->lock which we're now holding. | |
3114 | */ | |
3115 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
3116 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
3117 | ||
c93f7669 | 3118 | do_switch = 0; |
bfbd3381 | 3119 | |
cdd6c482 | 3120 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 3121 | } |
e625cce1 TG |
3122 | raw_spin_unlock(&next_ctx->lock); |
3123 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 3124 | } |
5a3126d4 | 3125 | unlock: |
c93f7669 | 3126 | rcu_read_unlock(); |
564c2b21 | 3127 | |
c93f7669 | 3128 | if (do_switch) { |
facc4307 | 3129 | raw_spin_lock(&ctx->lock); |
487f05e1 | 3130 | task_ctx_sched_out(cpuctx, ctx, EVENT_ALL); |
facc4307 | 3131 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 3132 | } |
0793a61d TG |
3133 | } |
3134 | ||
e48c1788 PZ |
3135 | static DEFINE_PER_CPU(struct list_head, sched_cb_list); |
3136 | ||
ba532500 YZ |
3137 | void perf_sched_cb_dec(struct pmu *pmu) |
3138 | { | |
e48c1788 PZ |
3139 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
3140 | ||
ba532500 | 3141 | this_cpu_dec(perf_sched_cb_usages); |
e48c1788 PZ |
3142 | |
3143 | if (!--cpuctx->sched_cb_usage) | |
3144 | list_del(&cpuctx->sched_cb_entry); | |
ba532500 YZ |
3145 | } |
3146 | ||
e48c1788 | 3147 | |
ba532500 YZ |
3148 | void perf_sched_cb_inc(struct pmu *pmu) |
3149 | { | |
e48c1788 PZ |
3150 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
3151 | ||
3152 | if (!cpuctx->sched_cb_usage++) | |
3153 | list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list)); | |
3154 | ||
ba532500 YZ |
3155 | this_cpu_inc(perf_sched_cb_usages); |
3156 | } | |
3157 | ||
3158 | /* | |
3159 | * This function provides the context switch callback to the lower code | |
3160 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
09e61b4f PZ |
3161 | * |
3162 | * This callback is relevant even to per-cpu events; for example multi event | |
3163 | * PEBS requires this to provide PID/TID information. This requires we flush | |
3164 | * all queued PEBS records before we context switch to a new task. | |
ba532500 YZ |
3165 | */ |
3166 | static void perf_pmu_sched_task(struct task_struct *prev, | |
3167 | struct task_struct *next, | |
3168 | bool sched_in) | |
3169 | { | |
3170 | struct perf_cpu_context *cpuctx; | |
3171 | struct pmu *pmu; | |
ba532500 YZ |
3172 | |
3173 | if (prev == next) | |
3174 | return; | |
3175 | ||
e48c1788 | 3176 | list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) { |
1fd7e416 | 3177 | pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */ |
ba532500 | 3178 | |
e48c1788 PZ |
3179 | if (WARN_ON_ONCE(!pmu->sched_task)) |
3180 | continue; | |
ba532500 | 3181 | |
e48c1788 PZ |
3182 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
3183 | perf_pmu_disable(pmu); | |
ba532500 | 3184 | |
e48c1788 | 3185 | pmu->sched_task(cpuctx->task_ctx, sched_in); |
ba532500 | 3186 | |
e48c1788 PZ |
3187 | perf_pmu_enable(pmu); |
3188 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
ba532500 | 3189 | } |
ba532500 YZ |
3190 | } |
3191 | ||
45ac1403 AH |
3192 | static void perf_event_switch(struct task_struct *task, |
3193 | struct task_struct *next_prev, bool sched_in); | |
3194 | ||
8dc85d54 PZ |
3195 | #define for_each_task_context_nr(ctxn) \ |
3196 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
3197 | ||
3198 | /* | |
3199 | * Called from scheduler to remove the events of the current task, | |
3200 | * with interrupts disabled. | |
3201 | * | |
3202 | * We stop each event and update the event value in event->count. | |
3203 | * | |
3204 | * This does not protect us against NMI, but disable() | |
3205 | * sets the disabled bit in the control field of event _before_ | |
3206 | * accessing the event control register. If a NMI hits, then it will | |
3207 | * not restart the event. | |
3208 | */ | |
ab0cce56 JO |
3209 | void __perf_event_task_sched_out(struct task_struct *task, |
3210 | struct task_struct *next) | |
8dc85d54 PZ |
3211 | { |
3212 | int ctxn; | |
3213 | ||
ba532500 YZ |
3214 | if (__this_cpu_read(perf_sched_cb_usages)) |
3215 | perf_pmu_sched_task(task, next, false); | |
3216 | ||
45ac1403 AH |
3217 | if (atomic_read(&nr_switch_events)) |
3218 | perf_event_switch(task, next, false); | |
3219 | ||
8dc85d54 PZ |
3220 | for_each_task_context_nr(ctxn) |
3221 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
3222 | |
3223 | /* | |
3224 | * if cgroup events exist on this CPU, then we need | |
3225 | * to check if we have to switch out PMU state. | |
3226 | * cgroup event are system-wide mode only | |
3227 | */ | |
4a32fea9 | 3228 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 3229 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
3230 | } |
3231 | ||
5b0311e1 FW |
3232 | /* |
3233 | * Called with IRQs disabled | |
3234 | */ | |
3235 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
3236 | enum event_type_t event_type) | |
3237 | { | |
3238 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
3239 | } |
3240 | ||
1cac7b1a PZ |
3241 | static int visit_groups_merge(struct perf_event_groups *groups, int cpu, |
3242 | int (*func)(struct perf_event *, void *), void *data) | |
0793a61d | 3243 | { |
1cac7b1a PZ |
3244 | struct perf_event **evt, *evt1, *evt2; |
3245 | int ret; | |
8e1a2031 | 3246 | |
1cac7b1a PZ |
3247 | evt1 = perf_event_groups_first(groups, -1); |
3248 | evt2 = perf_event_groups_first(groups, cpu); | |
3249 | ||
3250 | while (evt1 || evt2) { | |
3251 | if (evt1 && evt2) { | |
3252 | if (evt1->group_index < evt2->group_index) | |
3253 | evt = &evt1; | |
3254 | else | |
3255 | evt = &evt2; | |
3256 | } else if (evt1) { | |
3257 | evt = &evt1; | |
3258 | } else { | |
3259 | evt = &evt2; | |
8e1a2031 | 3260 | } |
1cac7b1a PZ |
3261 | |
3262 | ret = func(*evt, data); | |
3263 | if (ret) | |
3264 | return ret; | |
3265 | ||
3266 | *evt = perf_event_groups_next(*evt); | |
8e1a2031 | 3267 | } |
0793a61d | 3268 | |
1cac7b1a PZ |
3269 | return 0; |
3270 | } | |
3271 | ||
3272 | struct sched_in_data { | |
3273 | struct perf_event_context *ctx; | |
3274 | struct perf_cpu_context *cpuctx; | |
3275 | int can_add_hw; | |
3276 | }; | |
3277 | ||
3278 | static int pinned_sched_in(struct perf_event *event, void *data) | |
3279 | { | |
3280 | struct sched_in_data *sid = data; | |
3281 | ||
3282 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3283 | return 0; | |
3284 | ||
3285 | if (!event_filter_match(event)) | |
3286 | return 0; | |
3287 | ||
6668128a PZ |
3288 | if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) { |
3289 | if (!group_sched_in(event, sid->cpuctx, sid->ctx)) | |
3290 | list_add_tail(&event->active_list, &sid->ctx->pinned_active); | |
3291 | } | |
1cac7b1a PZ |
3292 | |
3293 | /* | |
3294 | * If this pinned group hasn't been scheduled, | |
3295 | * put it in error state. | |
3296 | */ | |
3297 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
3298 | perf_event_set_state(event, PERF_EVENT_STATE_ERROR); | |
3299 | ||
3300 | return 0; | |
3301 | } | |
3302 | ||
3303 | static int flexible_sched_in(struct perf_event *event, void *data) | |
3304 | { | |
3305 | struct sched_in_data *sid = data; | |
3306 | ||
3307 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3308 | return 0; | |
3309 | ||
3310 | if (!event_filter_match(event)) | |
3311 | return 0; | |
3312 | ||
3313 | if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) { | |
6668128a PZ |
3314 | if (!group_sched_in(event, sid->cpuctx, sid->ctx)) |
3315 | list_add_tail(&event->active_list, &sid->ctx->flexible_active); | |
3316 | else | |
1cac7b1a | 3317 | sid->can_add_hw = 0; |
3b6f9e5c | 3318 | } |
1cac7b1a PZ |
3319 | |
3320 | return 0; | |
5b0311e1 FW |
3321 | } |
3322 | ||
3323 | static void | |
1cac7b1a PZ |
3324 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
3325 | struct perf_cpu_context *cpuctx) | |
5b0311e1 | 3326 | { |
1cac7b1a PZ |
3327 | struct sched_in_data sid = { |
3328 | .ctx = ctx, | |
3329 | .cpuctx = cpuctx, | |
3330 | .can_add_hw = 1, | |
3331 | }; | |
3b6f9e5c | 3332 | |
1cac7b1a PZ |
3333 | visit_groups_merge(&ctx->pinned_groups, |
3334 | smp_processor_id(), | |
3335 | pinned_sched_in, &sid); | |
3336 | } | |
8e1a2031 | 3337 | |
1cac7b1a PZ |
3338 | static void |
3339 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
3340 | struct perf_cpu_context *cpuctx) | |
3341 | { | |
3342 | struct sched_in_data sid = { | |
3343 | .ctx = ctx, | |
3344 | .cpuctx = cpuctx, | |
3345 | .can_add_hw = 1, | |
3346 | }; | |
0793a61d | 3347 | |
1cac7b1a PZ |
3348 | visit_groups_merge(&ctx->flexible_groups, |
3349 | smp_processor_id(), | |
3350 | flexible_sched_in, &sid); | |
5b0311e1 FW |
3351 | } |
3352 | ||
3353 | static void | |
3354 | ctx_sched_in(struct perf_event_context *ctx, | |
3355 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
3356 | enum event_type_t event_type, |
3357 | struct task_struct *task) | |
5b0311e1 | 3358 | { |
db24d33e | 3359 | int is_active = ctx->is_active; |
c994d613 PZ |
3360 | u64 now; |
3361 | ||
3362 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 3363 | |
5b0311e1 | 3364 | if (likely(!ctx->nr_events)) |
facc4307 | 3365 | return; |
5b0311e1 | 3366 | |
3cbaa590 | 3367 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
3368 | if (ctx->task) { |
3369 | if (!is_active) | |
3370 | cpuctx->task_ctx = ctx; | |
3371 | else | |
3372 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
3373 | } | |
3374 | ||
3cbaa590 PZ |
3375 | is_active ^= ctx->is_active; /* changed bits */ |
3376 | ||
3377 | if (is_active & EVENT_TIME) { | |
3378 | /* start ctx time */ | |
3379 | now = perf_clock(); | |
3380 | ctx->timestamp = now; | |
3381 | perf_cgroup_set_timestamp(task, ctx); | |
3382 | } | |
3383 | ||
5b0311e1 FW |
3384 | /* |
3385 | * First go through the list and put on any pinned groups | |
3386 | * in order to give them the best chance of going on. | |
3387 | */ | |
3cbaa590 | 3388 | if (is_active & EVENT_PINNED) |
6e37738a | 3389 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
3390 | |
3391 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 3392 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 3393 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
3394 | } |
3395 | ||
329c0e01 | 3396 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
3397 | enum event_type_t event_type, |
3398 | struct task_struct *task) | |
329c0e01 FW |
3399 | { |
3400 | struct perf_event_context *ctx = &cpuctx->ctx; | |
3401 | ||
e5d1367f | 3402 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
3403 | } |
3404 | ||
e5d1367f SE |
3405 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
3406 | struct task_struct *task) | |
235c7fc7 | 3407 | { |
108b02cf | 3408 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 3409 | |
108b02cf | 3410 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
3411 | if (cpuctx->task_ctx == ctx) |
3412 | return; | |
3413 | ||
facc4307 | 3414 | perf_ctx_lock(cpuctx, ctx); |
fdccc3fb | 3415 | /* |
3416 | * We must check ctx->nr_events while holding ctx->lock, such | |
3417 | * that we serialize against perf_install_in_context(). | |
3418 | */ | |
3419 | if (!ctx->nr_events) | |
3420 | goto unlock; | |
3421 | ||
1b9a644f | 3422 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
3423 | /* |
3424 | * We want to keep the following priority order: | |
3425 | * cpu pinned (that don't need to move), task pinned, | |
3426 | * cpu flexible, task flexible. | |
fe45bafb AS |
3427 | * |
3428 | * However, if task's ctx is not carrying any pinned | |
3429 | * events, no need to flip the cpuctx's events around. | |
329c0e01 | 3430 | */ |
8e1a2031 | 3431 | if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) |
fe45bafb | 3432 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
63e30d3e | 3433 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 | 3434 | perf_pmu_enable(ctx->pmu); |
fdccc3fb | 3435 | |
3436 | unlock: | |
facc4307 | 3437 | perf_ctx_unlock(cpuctx, ctx); |
235c7fc7 IM |
3438 | } |
3439 | ||
8dc85d54 PZ |
3440 | /* |
3441 | * Called from scheduler to add the events of the current task | |
3442 | * with interrupts disabled. | |
3443 | * | |
3444 | * We restore the event value and then enable it. | |
3445 | * | |
3446 | * This does not protect us against NMI, but enable() | |
3447 | * sets the enabled bit in the control field of event _before_ | |
3448 | * accessing the event control register. If a NMI hits, then it will | |
3449 | * keep the event running. | |
3450 | */ | |
ab0cce56 JO |
3451 | void __perf_event_task_sched_in(struct task_struct *prev, |
3452 | struct task_struct *task) | |
8dc85d54 PZ |
3453 | { |
3454 | struct perf_event_context *ctx; | |
3455 | int ctxn; | |
3456 | ||
7e41d177 PZ |
3457 | /* |
3458 | * If cgroup events exist on this CPU, then we need to check if we have | |
3459 | * to switch in PMU state; cgroup event are system-wide mode only. | |
3460 | * | |
3461 | * Since cgroup events are CPU events, we must schedule these in before | |
3462 | * we schedule in the task events. | |
3463 | */ | |
3464 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
3465 | perf_cgroup_sched_in(prev, task); | |
3466 | ||
8dc85d54 PZ |
3467 | for_each_task_context_nr(ctxn) { |
3468 | ctx = task->perf_event_ctxp[ctxn]; | |
3469 | if (likely(!ctx)) | |
3470 | continue; | |
3471 | ||
e5d1367f | 3472 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 3473 | } |
d010b332 | 3474 | |
45ac1403 AH |
3475 | if (atomic_read(&nr_switch_events)) |
3476 | perf_event_switch(task, prev, true); | |
3477 | ||
ba532500 YZ |
3478 | if (__this_cpu_read(perf_sched_cb_usages)) |
3479 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
3480 | } |
3481 | ||
abd50713 PZ |
3482 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
3483 | { | |
3484 | u64 frequency = event->attr.sample_freq; | |
3485 | u64 sec = NSEC_PER_SEC; | |
3486 | u64 divisor, dividend; | |
3487 | ||
3488 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
3489 | ||
3490 | count_fls = fls64(count); | |
3491 | nsec_fls = fls64(nsec); | |
3492 | frequency_fls = fls64(frequency); | |
3493 | sec_fls = 30; | |
3494 | ||
3495 | /* | |
3496 | * We got @count in @nsec, with a target of sample_freq HZ | |
3497 | * the target period becomes: | |
3498 | * | |
3499 | * @count * 10^9 | |
3500 | * period = ------------------- | |
3501 | * @nsec * sample_freq | |
3502 | * | |
3503 | */ | |
3504 | ||
3505 | /* | |
3506 | * Reduce accuracy by one bit such that @a and @b converge | |
3507 | * to a similar magnitude. | |
3508 | */ | |
fe4b04fa | 3509 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
3510 | do { \ |
3511 | if (a##_fls > b##_fls) { \ | |
3512 | a >>= 1; \ | |
3513 | a##_fls--; \ | |
3514 | } else { \ | |
3515 | b >>= 1; \ | |
3516 | b##_fls--; \ | |
3517 | } \ | |
3518 | } while (0) | |
3519 | ||
3520 | /* | |
3521 | * Reduce accuracy until either term fits in a u64, then proceed with | |
3522 | * the other, so that finally we can do a u64/u64 division. | |
3523 | */ | |
3524 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
3525 | REDUCE_FLS(nsec, frequency); | |
3526 | REDUCE_FLS(sec, count); | |
3527 | } | |
3528 | ||
3529 | if (count_fls + sec_fls > 64) { | |
3530 | divisor = nsec * frequency; | |
3531 | ||
3532 | while (count_fls + sec_fls > 64) { | |
3533 | REDUCE_FLS(count, sec); | |
3534 | divisor >>= 1; | |
3535 | } | |
3536 | ||
3537 | dividend = count * sec; | |
3538 | } else { | |
3539 | dividend = count * sec; | |
3540 | ||
3541 | while (nsec_fls + frequency_fls > 64) { | |
3542 | REDUCE_FLS(nsec, frequency); | |
3543 | dividend >>= 1; | |
3544 | } | |
3545 | ||
3546 | divisor = nsec * frequency; | |
3547 | } | |
3548 | ||
f6ab91ad PZ |
3549 | if (!divisor) |
3550 | return dividend; | |
3551 | ||
abd50713 PZ |
3552 | return div64_u64(dividend, divisor); |
3553 | } | |
3554 | ||
e050e3f0 SE |
3555 | static DEFINE_PER_CPU(int, perf_throttled_count); |
3556 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
3557 | ||
f39d47ff | 3558 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 3559 | { |
cdd6c482 | 3560 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 3561 | s64 period, sample_period; |
bd2b5b12 PZ |
3562 | s64 delta; |
3563 | ||
abd50713 | 3564 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
3565 | |
3566 | delta = (s64)(period - hwc->sample_period); | |
3567 | delta = (delta + 7) / 8; /* low pass filter */ | |
3568 | ||
3569 | sample_period = hwc->sample_period + delta; | |
3570 | ||
3571 | if (!sample_period) | |
3572 | sample_period = 1; | |
3573 | ||
bd2b5b12 | 3574 | hwc->sample_period = sample_period; |
abd50713 | 3575 | |
e7850595 | 3576 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
3577 | if (disable) |
3578 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3579 | ||
e7850595 | 3580 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
3581 | |
3582 | if (disable) | |
3583 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 3584 | } |
bd2b5b12 PZ |
3585 | } |
3586 | ||
e050e3f0 SE |
3587 | /* |
3588 | * combine freq adjustment with unthrottling to avoid two passes over the | |
3589 | * events. At the same time, make sure, having freq events does not change | |
3590 | * the rate of unthrottling as that would introduce bias. | |
3591 | */ | |
3592 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
3593 | int needs_unthr) | |
60db5e09 | 3594 | { |
cdd6c482 IM |
3595 | struct perf_event *event; |
3596 | struct hw_perf_event *hwc; | |
e050e3f0 | 3597 | u64 now, period = TICK_NSEC; |
abd50713 | 3598 | s64 delta; |
60db5e09 | 3599 | |
e050e3f0 SE |
3600 | /* |
3601 | * only need to iterate over all events iff: | |
3602 | * - context have events in frequency mode (needs freq adjust) | |
3603 | * - there are events to unthrottle on this cpu | |
3604 | */ | |
3605 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
3606 | return; |
3607 | ||
e050e3f0 | 3608 | raw_spin_lock(&ctx->lock); |
f39d47ff | 3609 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 3610 | |
03541f8b | 3611 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 3612 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
3613 | continue; |
3614 | ||
5632ab12 | 3615 | if (!event_filter_match(event)) |
5d27c23d PZ |
3616 | continue; |
3617 | ||
44377277 AS |
3618 | perf_pmu_disable(event->pmu); |
3619 | ||
cdd6c482 | 3620 | hwc = &event->hw; |
6a24ed6c | 3621 | |
ae23bff1 | 3622 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 3623 | hwc->interrupts = 0; |
cdd6c482 | 3624 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3625 | event->pmu->start(event, 0); |
a78ac325 PZ |
3626 | } |
3627 | ||
cdd6c482 | 3628 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3629 | goto next; |
60db5e09 | 3630 | |
e050e3f0 SE |
3631 | /* |
3632 | * stop the event and update event->count | |
3633 | */ | |
3634 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3635 | ||
e7850595 | 3636 | now = local64_read(&event->count); |
abd50713 PZ |
3637 | delta = now - hwc->freq_count_stamp; |
3638 | hwc->freq_count_stamp = now; | |
60db5e09 | 3639 | |
e050e3f0 SE |
3640 | /* |
3641 | * restart the event | |
3642 | * reload only if value has changed | |
f39d47ff SE |
3643 | * we have stopped the event so tell that |
3644 | * to perf_adjust_period() to avoid stopping it | |
3645 | * twice. | |
e050e3f0 | 3646 | */ |
abd50713 | 3647 | if (delta > 0) |
f39d47ff | 3648 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3649 | |
3650 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3651 | next: |
3652 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3653 | } |
e050e3f0 | 3654 | |
f39d47ff | 3655 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3656 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3657 | } |
3658 | ||
235c7fc7 | 3659 | /* |
8703a7cf | 3660 | * Move @event to the tail of the @ctx's elegible events. |
235c7fc7 | 3661 | */ |
8703a7cf | 3662 | static void rotate_ctx(struct perf_event_context *ctx, struct perf_event *event) |
0793a61d | 3663 | { |
dddd3379 TG |
3664 | /* |
3665 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3666 | * disabled by the inheritance code. | |
3667 | */ | |
8703a7cf PZ |
3668 | if (ctx->rotate_disable) |
3669 | return; | |
8e1a2031 | 3670 | |
8703a7cf PZ |
3671 | perf_event_groups_delete(&ctx->flexible_groups, event); |
3672 | perf_event_groups_insert(&ctx->flexible_groups, event); | |
235c7fc7 IM |
3673 | } |
3674 | ||
8d5bce0c PZ |
3675 | static inline struct perf_event * |
3676 | ctx_first_active(struct perf_event_context *ctx) | |
235c7fc7 | 3677 | { |
8d5bce0c PZ |
3678 | return list_first_entry_or_null(&ctx->flexible_active, |
3679 | struct perf_event, active_list); | |
3680 | } | |
3681 | ||
3682 | static bool perf_rotate_context(struct perf_cpu_context *cpuctx) | |
3683 | { | |
3684 | struct perf_event *cpu_event = NULL, *task_event = NULL; | |
3685 | bool cpu_rotate = false, task_rotate = false; | |
8dc85d54 | 3686 | struct perf_event_context *ctx = NULL; |
8d5bce0c PZ |
3687 | |
3688 | /* | |
3689 | * Since we run this from IRQ context, nobody can install new | |
3690 | * events, thus the event count values are stable. | |
3691 | */ | |
7fc23a53 | 3692 | |
b5ab4cd5 | 3693 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 | 3694 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
8d5bce0c | 3695 | cpu_rotate = true; |
b5ab4cd5 | 3696 | } |
235c7fc7 | 3697 | |
8dc85d54 | 3698 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3699 | if (ctx && ctx->nr_events) { |
b5ab4cd5 | 3700 | if (ctx->nr_events != ctx->nr_active) |
8d5bce0c | 3701 | task_rotate = true; |
b5ab4cd5 | 3702 | } |
9717e6cd | 3703 | |
8d5bce0c PZ |
3704 | if (!(cpu_rotate || task_rotate)) |
3705 | return false; | |
0f5a2601 | 3706 | |
facc4307 | 3707 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3708 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3709 | |
8d5bce0c PZ |
3710 | if (task_rotate) |
3711 | task_event = ctx_first_active(ctx); | |
3712 | if (cpu_rotate) | |
3713 | cpu_event = ctx_first_active(&cpuctx->ctx); | |
8703a7cf | 3714 | |
8d5bce0c PZ |
3715 | /* |
3716 | * As per the order given at ctx_resched() first 'pop' task flexible | |
3717 | * and then, if needed CPU flexible. | |
3718 | */ | |
3719 | if (task_event || (ctx && cpu_event)) | |
e050e3f0 | 3720 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); |
8d5bce0c PZ |
3721 | if (cpu_event) |
3722 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3723 | |
8d5bce0c PZ |
3724 | if (task_event) |
3725 | rotate_ctx(ctx, task_event); | |
3726 | if (cpu_event) | |
3727 | rotate_ctx(&cpuctx->ctx, cpu_event); | |
235c7fc7 | 3728 | |
e050e3f0 | 3729 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3730 | |
0f5a2601 PZ |
3731 | perf_pmu_enable(cpuctx->ctx.pmu); |
3732 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
9e630205 | 3733 | |
8d5bce0c | 3734 | return true; |
e9d2b064 PZ |
3735 | } |
3736 | ||
3737 | void perf_event_task_tick(void) | |
3738 | { | |
2fde4f94 MR |
3739 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3740 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3741 | int throttled; |
b5ab4cd5 | 3742 | |
16444645 | 3743 | lockdep_assert_irqs_disabled(); |
e9d2b064 | 3744 | |
e050e3f0 SE |
3745 | __this_cpu_inc(perf_throttled_seq); |
3746 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
555e0c1e | 3747 | tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
e050e3f0 | 3748 | |
2fde4f94 | 3749 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3750 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3751 | } |
3752 | ||
889ff015 FW |
3753 | static int event_enable_on_exec(struct perf_event *event, |
3754 | struct perf_event_context *ctx) | |
3755 | { | |
3756 | if (!event->attr.enable_on_exec) | |
3757 | return 0; | |
3758 | ||
3759 | event->attr.enable_on_exec = 0; | |
3760 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3761 | return 0; | |
3762 | ||
0d3d73aa | 3763 | perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); |
889ff015 FW |
3764 | |
3765 | return 1; | |
3766 | } | |
3767 | ||
57e7986e | 3768 | /* |
cdd6c482 | 3769 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3770 | * This expects task == current. |
3771 | */ | |
c1274499 | 3772 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3773 | { |
c1274499 | 3774 | struct perf_event_context *ctx, *clone_ctx = NULL; |
487f05e1 | 3775 | enum event_type_t event_type = 0; |
3e349507 | 3776 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3777 | struct perf_event *event; |
57e7986e PM |
3778 | unsigned long flags; |
3779 | int enabled = 0; | |
3780 | ||
3781 | local_irq_save(flags); | |
c1274499 | 3782 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3783 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3784 | goto out; |
3785 | ||
3e349507 PZ |
3786 | cpuctx = __get_cpu_context(ctx); |
3787 | perf_ctx_lock(cpuctx, ctx); | |
7fce2509 | 3788 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
487f05e1 | 3789 | list_for_each_entry(event, &ctx->event_list, event_entry) { |
3e349507 | 3790 | enabled |= event_enable_on_exec(event, ctx); |
487f05e1 AS |
3791 | event_type |= get_event_type(event); |
3792 | } | |
57e7986e PM |
3793 | |
3794 | /* | |
3e349507 | 3795 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3796 | */ |
3e349507 | 3797 | if (enabled) { |
211de6eb | 3798 | clone_ctx = unclone_ctx(ctx); |
487f05e1 | 3799 | ctx_resched(cpuctx, ctx, event_type); |
7bbba0eb PZ |
3800 | } else { |
3801 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
3e349507 PZ |
3802 | } |
3803 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3804 | |
9ed6060d | 3805 | out: |
57e7986e | 3806 | local_irq_restore(flags); |
211de6eb PZ |
3807 | |
3808 | if (clone_ctx) | |
3809 | put_ctx(clone_ctx); | |
57e7986e PM |
3810 | } |
3811 | ||
0492d4c5 PZ |
3812 | struct perf_read_data { |
3813 | struct perf_event *event; | |
3814 | bool group; | |
7d88962e | 3815 | int ret; |
0492d4c5 PZ |
3816 | }; |
3817 | ||
451d24d1 | 3818 | static int __perf_event_read_cpu(struct perf_event *event, int event_cpu) |
d6a2f903 | 3819 | { |
d6a2f903 DCC |
3820 | u16 local_pkg, event_pkg; |
3821 | ||
3822 | if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { | |
451d24d1 PZ |
3823 | int local_cpu = smp_processor_id(); |
3824 | ||
3825 | event_pkg = topology_physical_package_id(event_cpu); | |
3826 | local_pkg = topology_physical_package_id(local_cpu); | |
d6a2f903 DCC |
3827 | |
3828 | if (event_pkg == local_pkg) | |
3829 | return local_cpu; | |
3830 | } | |
3831 | ||
3832 | return event_cpu; | |
3833 | } | |
3834 | ||
0793a61d | 3835 | /* |
cdd6c482 | 3836 | * Cross CPU call to read the hardware event |
0793a61d | 3837 | */ |
cdd6c482 | 3838 | static void __perf_event_read(void *info) |
0793a61d | 3839 | { |
0492d4c5 PZ |
3840 | struct perf_read_data *data = info; |
3841 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3842 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3843 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3844 | struct pmu *pmu = event->pmu; |
621a01ea | 3845 | |
e1ac3614 PM |
3846 | /* |
3847 | * If this is a task context, we need to check whether it is | |
3848 | * the current task context of this cpu. If not it has been | |
3849 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3850 | * event->count would have been updated to a recent sample |
3851 | * when the event was scheduled out. | |
e1ac3614 PM |
3852 | */ |
3853 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3854 | return; | |
3855 | ||
e625cce1 | 3856 | raw_spin_lock(&ctx->lock); |
0c1cbc18 | 3857 | if (ctx->is_active & EVENT_TIME) { |
542e72fc | 3858 | update_context_time(ctx); |
e5d1367f SE |
3859 | update_cgrp_time_from_event(event); |
3860 | } | |
0492d4c5 | 3861 | |
0d3d73aa PZ |
3862 | perf_event_update_time(event); |
3863 | if (data->group) | |
3864 | perf_event_update_sibling_time(event); | |
0c1cbc18 | 3865 | |
4a00c16e SB |
3866 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3867 | goto unlock; | |
0492d4c5 | 3868 | |
4a00c16e SB |
3869 | if (!data->group) { |
3870 | pmu->read(event); | |
3871 | data->ret = 0; | |
0492d4c5 | 3872 | goto unlock; |
4a00c16e SB |
3873 | } |
3874 | ||
3875 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3876 | ||
3877 | pmu->read(event); | |
0492d4c5 | 3878 | |
edb39592 | 3879 | for_each_sibling_event(sub, event) { |
4a00c16e SB |
3880 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3881 | /* | |
3882 | * Use sibling's PMU rather than @event's since | |
3883 | * sibling could be on different (eg: software) PMU. | |
3884 | */ | |
0492d4c5 | 3885 | sub->pmu->read(sub); |
4a00c16e | 3886 | } |
0492d4c5 | 3887 | } |
4a00c16e SB |
3888 | |
3889 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3890 | |
3891 | unlock: | |
e625cce1 | 3892 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3893 | } |
3894 | ||
b5e58793 PZ |
3895 | static inline u64 perf_event_count(struct perf_event *event) |
3896 | { | |
c39a0e2c | 3897 | return local64_read(&event->count) + atomic64_read(&event->child_count); |
b5e58793 PZ |
3898 | } |
3899 | ||
ffe8690c KX |
3900 | /* |
3901 | * NMI-safe method to read a local event, that is an event that | |
3902 | * is: | |
3903 | * - either for the current task, or for this CPU | |
3904 | * - does not have inherit set, for inherited task events | |
3905 | * will not be local and we cannot read them atomically | |
3906 | * - must not have a pmu::count method | |
3907 | */ | |
7d9285e8 YS |
3908 | int perf_event_read_local(struct perf_event *event, u64 *value, |
3909 | u64 *enabled, u64 *running) | |
ffe8690c KX |
3910 | { |
3911 | unsigned long flags; | |
f91840a3 | 3912 | int ret = 0; |
ffe8690c KX |
3913 | |
3914 | /* | |
3915 | * Disabling interrupts avoids all counter scheduling (context | |
3916 | * switches, timer based rotation and IPIs). | |
3917 | */ | |
3918 | local_irq_save(flags); | |
3919 | ||
ffe8690c KX |
3920 | /* |
3921 | * It must not be an event with inherit set, we cannot read | |
3922 | * all child counters from atomic context. | |
3923 | */ | |
f91840a3 AS |
3924 | if (event->attr.inherit) { |
3925 | ret = -EOPNOTSUPP; | |
3926 | goto out; | |
3927 | } | |
ffe8690c | 3928 | |
f91840a3 AS |
3929 | /* If this is a per-task event, it must be for current */ |
3930 | if ((event->attach_state & PERF_ATTACH_TASK) && | |
3931 | event->hw.target != current) { | |
3932 | ret = -EINVAL; | |
3933 | goto out; | |
3934 | } | |
3935 | ||
3936 | /* If this is a per-CPU event, it must be for this CPU */ | |
3937 | if (!(event->attach_state & PERF_ATTACH_TASK) && | |
3938 | event->cpu != smp_processor_id()) { | |
3939 | ret = -EINVAL; | |
3940 | goto out; | |
3941 | } | |
ffe8690c KX |
3942 | |
3943 | /* | |
3944 | * If the event is currently on this CPU, its either a per-task event, | |
3945 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3946 | * oncpu == -1). | |
3947 | */ | |
3948 | if (event->oncpu == smp_processor_id()) | |
3949 | event->pmu->read(event); | |
3950 | ||
f91840a3 | 3951 | *value = local64_read(&event->count); |
0d3d73aa PZ |
3952 | if (enabled || running) { |
3953 | u64 now = event->shadow_ctx_time + perf_clock(); | |
3954 | u64 __enabled, __running; | |
3955 | ||
3956 | __perf_update_times(event, now, &__enabled, &__running); | |
3957 | if (enabled) | |
3958 | *enabled = __enabled; | |
3959 | if (running) | |
3960 | *running = __running; | |
3961 | } | |
f91840a3 | 3962 | out: |
ffe8690c KX |
3963 | local_irq_restore(flags); |
3964 | ||
f91840a3 | 3965 | return ret; |
ffe8690c KX |
3966 | } |
3967 | ||
7d88962e | 3968 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3969 | { |
0c1cbc18 | 3970 | enum perf_event_state state = READ_ONCE(event->state); |
451d24d1 | 3971 | int event_cpu, ret = 0; |
7d88962e | 3972 | |
0793a61d | 3973 | /* |
cdd6c482 IM |
3974 | * If event is enabled and currently active on a CPU, update the |
3975 | * value in the event structure: | |
0793a61d | 3976 | */ |
0c1cbc18 PZ |
3977 | again: |
3978 | if (state == PERF_EVENT_STATE_ACTIVE) { | |
3979 | struct perf_read_data data; | |
3980 | ||
3981 | /* | |
3982 | * Orders the ->state and ->oncpu loads such that if we see | |
3983 | * ACTIVE we must also see the right ->oncpu. | |
3984 | * | |
3985 | * Matches the smp_wmb() from event_sched_in(). | |
3986 | */ | |
3987 | smp_rmb(); | |
d6a2f903 | 3988 | |
451d24d1 PZ |
3989 | event_cpu = READ_ONCE(event->oncpu); |
3990 | if ((unsigned)event_cpu >= nr_cpu_ids) | |
3991 | return 0; | |
3992 | ||
0c1cbc18 PZ |
3993 | data = (struct perf_read_data){ |
3994 | .event = event, | |
3995 | .group = group, | |
3996 | .ret = 0, | |
3997 | }; | |
3998 | ||
451d24d1 PZ |
3999 | preempt_disable(); |
4000 | event_cpu = __perf_event_read_cpu(event, event_cpu); | |
d6a2f903 | 4001 | |
58763148 PZ |
4002 | /* |
4003 | * Purposely ignore the smp_call_function_single() return | |
4004 | * value. | |
4005 | * | |
451d24d1 | 4006 | * If event_cpu isn't a valid CPU it means the event got |
58763148 PZ |
4007 | * scheduled out and that will have updated the event count. |
4008 | * | |
4009 | * Therefore, either way, we'll have an up-to-date event count | |
4010 | * after this. | |
4011 | */ | |
451d24d1 PZ |
4012 | (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); |
4013 | preempt_enable(); | |
58763148 | 4014 | ret = data.ret; |
0c1cbc18 PZ |
4015 | |
4016 | } else if (state == PERF_EVENT_STATE_INACTIVE) { | |
2b8988c9 PZ |
4017 | struct perf_event_context *ctx = event->ctx; |
4018 | unsigned long flags; | |
4019 | ||
e625cce1 | 4020 | raw_spin_lock_irqsave(&ctx->lock, flags); |
0c1cbc18 PZ |
4021 | state = event->state; |
4022 | if (state != PERF_EVENT_STATE_INACTIVE) { | |
4023 | raw_spin_unlock_irqrestore(&ctx->lock, flags); | |
4024 | goto again; | |
4025 | } | |
4026 | ||
c530ccd9 | 4027 | /* |
0c1cbc18 PZ |
4028 | * May read while context is not active (e.g., thread is |
4029 | * blocked), in that case we cannot update context time | |
c530ccd9 | 4030 | */ |
0c1cbc18 | 4031 | if (ctx->is_active & EVENT_TIME) { |
c530ccd9 | 4032 | update_context_time(ctx); |
e5d1367f SE |
4033 | update_cgrp_time_from_event(event); |
4034 | } | |
0c1cbc18 | 4035 | |
0d3d73aa | 4036 | perf_event_update_time(event); |
0492d4c5 | 4037 | if (group) |
0d3d73aa | 4038 | perf_event_update_sibling_time(event); |
e625cce1 | 4039 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 4040 | } |
7d88962e SB |
4041 | |
4042 | return ret; | |
0793a61d TG |
4043 | } |
4044 | ||
a63eaf34 | 4045 | /* |
cdd6c482 | 4046 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 4047 | */ |
eb184479 | 4048 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 4049 | { |
e625cce1 | 4050 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 4051 | mutex_init(&ctx->mutex); |
2fde4f94 | 4052 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
8e1a2031 AB |
4053 | perf_event_groups_init(&ctx->pinned_groups); |
4054 | perf_event_groups_init(&ctx->flexible_groups); | |
a63eaf34 | 4055 | INIT_LIST_HEAD(&ctx->event_list); |
6668128a PZ |
4056 | INIT_LIST_HEAD(&ctx->pinned_active); |
4057 | INIT_LIST_HEAD(&ctx->flexible_active); | |
a63eaf34 | 4058 | atomic_set(&ctx->refcount, 1); |
eb184479 PZ |
4059 | } |
4060 | ||
4061 | static struct perf_event_context * | |
4062 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
4063 | { | |
4064 | struct perf_event_context *ctx; | |
4065 | ||
4066 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
4067 | if (!ctx) | |
4068 | return NULL; | |
4069 | ||
4070 | __perf_event_init_context(ctx); | |
4071 | if (task) { | |
4072 | ctx->task = task; | |
4073 | get_task_struct(task); | |
0793a61d | 4074 | } |
eb184479 PZ |
4075 | ctx->pmu = pmu; |
4076 | ||
4077 | return ctx; | |
a63eaf34 PM |
4078 | } |
4079 | ||
2ebd4ffb MH |
4080 | static struct task_struct * |
4081 | find_lively_task_by_vpid(pid_t vpid) | |
4082 | { | |
4083 | struct task_struct *task; | |
0793a61d TG |
4084 | |
4085 | rcu_read_lock(); | |
2ebd4ffb | 4086 | if (!vpid) |
0793a61d TG |
4087 | task = current; |
4088 | else | |
2ebd4ffb | 4089 | task = find_task_by_vpid(vpid); |
0793a61d TG |
4090 | if (task) |
4091 | get_task_struct(task); | |
4092 | rcu_read_unlock(); | |
4093 | ||
4094 | if (!task) | |
4095 | return ERR_PTR(-ESRCH); | |
4096 | ||
2ebd4ffb | 4097 | return task; |
2ebd4ffb MH |
4098 | } |
4099 | ||
fe4b04fa PZ |
4100 | /* |
4101 | * Returns a matching context with refcount and pincount. | |
4102 | */ | |
108b02cf | 4103 | static struct perf_event_context * |
4af57ef2 YZ |
4104 | find_get_context(struct pmu *pmu, struct task_struct *task, |
4105 | struct perf_event *event) | |
0793a61d | 4106 | { |
211de6eb | 4107 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 4108 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 4109 | void *task_ctx_data = NULL; |
25346b93 | 4110 | unsigned long flags; |
8dc85d54 | 4111 | int ctxn, err; |
4af57ef2 | 4112 | int cpu = event->cpu; |
0793a61d | 4113 | |
22a4ec72 | 4114 | if (!task) { |
cdd6c482 | 4115 | /* Must be root to operate on a CPU event: */ |
0764771d | 4116 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
4117 | return ERR_PTR(-EACCES); |
4118 | ||
108b02cf | 4119 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 4120 | ctx = &cpuctx->ctx; |
c93f7669 | 4121 | get_ctx(ctx); |
fe4b04fa | 4122 | ++ctx->pin_count; |
0793a61d | 4123 | |
0793a61d TG |
4124 | return ctx; |
4125 | } | |
4126 | ||
8dc85d54 PZ |
4127 | err = -EINVAL; |
4128 | ctxn = pmu->task_ctx_nr; | |
4129 | if (ctxn < 0) | |
4130 | goto errout; | |
4131 | ||
4af57ef2 YZ |
4132 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
4133 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
4134 | if (!task_ctx_data) { | |
4135 | err = -ENOMEM; | |
4136 | goto errout; | |
4137 | } | |
4138 | } | |
4139 | ||
9ed6060d | 4140 | retry: |
8dc85d54 | 4141 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 4142 | if (ctx) { |
211de6eb | 4143 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 4144 | ++ctx->pin_count; |
4af57ef2 YZ |
4145 | |
4146 | if (task_ctx_data && !ctx->task_ctx_data) { | |
4147 | ctx->task_ctx_data = task_ctx_data; | |
4148 | task_ctx_data = NULL; | |
4149 | } | |
e625cce1 | 4150 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
4151 | |
4152 | if (clone_ctx) | |
4153 | put_ctx(clone_ctx); | |
9137fb28 | 4154 | } else { |
eb184479 | 4155 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
4156 | err = -ENOMEM; |
4157 | if (!ctx) | |
4158 | goto errout; | |
eb184479 | 4159 | |
4af57ef2 YZ |
4160 | if (task_ctx_data) { |
4161 | ctx->task_ctx_data = task_ctx_data; | |
4162 | task_ctx_data = NULL; | |
4163 | } | |
4164 | ||
dbe08d82 ON |
4165 | err = 0; |
4166 | mutex_lock(&task->perf_event_mutex); | |
4167 | /* | |
4168 | * If it has already passed perf_event_exit_task(). | |
4169 | * we must see PF_EXITING, it takes this mutex too. | |
4170 | */ | |
4171 | if (task->flags & PF_EXITING) | |
4172 | err = -ESRCH; | |
4173 | else if (task->perf_event_ctxp[ctxn]) | |
4174 | err = -EAGAIN; | |
fe4b04fa | 4175 | else { |
9137fb28 | 4176 | get_ctx(ctx); |
fe4b04fa | 4177 | ++ctx->pin_count; |
dbe08d82 | 4178 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 4179 | } |
dbe08d82 ON |
4180 | mutex_unlock(&task->perf_event_mutex); |
4181 | ||
4182 | if (unlikely(err)) { | |
9137fb28 | 4183 | put_ctx(ctx); |
dbe08d82 ON |
4184 | |
4185 | if (err == -EAGAIN) | |
4186 | goto retry; | |
4187 | goto errout; | |
a63eaf34 PM |
4188 | } |
4189 | } | |
4190 | ||
4af57ef2 | 4191 | kfree(task_ctx_data); |
0793a61d | 4192 | return ctx; |
c93f7669 | 4193 | |
9ed6060d | 4194 | errout: |
4af57ef2 | 4195 | kfree(task_ctx_data); |
c93f7669 | 4196 | return ERR_PTR(err); |
0793a61d TG |
4197 | } |
4198 | ||
6fb2915d | 4199 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 4200 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 4201 | |
cdd6c482 | 4202 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 4203 | { |
cdd6c482 | 4204 | struct perf_event *event; |
592903cd | 4205 | |
cdd6c482 IM |
4206 | event = container_of(head, struct perf_event, rcu_head); |
4207 | if (event->ns) | |
4208 | put_pid_ns(event->ns); | |
6fb2915d | 4209 | perf_event_free_filter(event); |
cdd6c482 | 4210 | kfree(event); |
592903cd PZ |
4211 | } |
4212 | ||
b69cf536 PZ |
4213 | static void ring_buffer_attach(struct perf_event *event, |
4214 | struct ring_buffer *rb); | |
925d519a | 4215 | |
f2fb6bef KL |
4216 | static void detach_sb_event(struct perf_event *event) |
4217 | { | |
4218 | struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu); | |
4219 | ||
4220 | raw_spin_lock(&pel->lock); | |
4221 | list_del_rcu(&event->sb_list); | |
4222 | raw_spin_unlock(&pel->lock); | |
4223 | } | |
4224 | ||
a4f144eb | 4225 | static bool is_sb_event(struct perf_event *event) |
f2fb6bef | 4226 | { |
a4f144eb DCC |
4227 | struct perf_event_attr *attr = &event->attr; |
4228 | ||
f2fb6bef | 4229 | if (event->parent) |
a4f144eb | 4230 | return false; |
f2fb6bef KL |
4231 | |
4232 | if (event->attach_state & PERF_ATTACH_TASK) | |
a4f144eb | 4233 | return false; |
f2fb6bef | 4234 | |
a4f144eb DCC |
4235 | if (attr->mmap || attr->mmap_data || attr->mmap2 || |
4236 | attr->comm || attr->comm_exec || | |
4237 | attr->task || | |
4238 | attr->context_switch) | |
4239 | return true; | |
4240 | return false; | |
4241 | } | |
4242 | ||
4243 | static void unaccount_pmu_sb_event(struct perf_event *event) | |
4244 | { | |
4245 | if (is_sb_event(event)) | |
4246 | detach_sb_event(event); | |
f2fb6bef KL |
4247 | } |
4248 | ||
4beb31f3 | 4249 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 4250 | { |
4beb31f3 FW |
4251 | if (event->parent) |
4252 | return; | |
4253 | ||
4beb31f3 FW |
4254 | if (is_cgroup_event(event)) |
4255 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
4256 | } | |
925d519a | 4257 | |
555e0c1e FW |
4258 | #ifdef CONFIG_NO_HZ_FULL |
4259 | static DEFINE_SPINLOCK(nr_freq_lock); | |
4260 | #endif | |
4261 | ||
4262 | static void unaccount_freq_event_nohz(void) | |
4263 | { | |
4264 | #ifdef CONFIG_NO_HZ_FULL | |
4265 | spin_lock(&nr_freq_lock); | |
4266 | if (atomic_dec_and_test(&nr_freq_events)) | |
4267 | tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS); | |
4268 | spin_unlock(&nr_freq_lock); | |
4269 | #endif | |
4270 | } | |
4271 | ||
4272 | static void unaccount_freq_event(void) | |
4273 | { | |
4274 | if (tick_nohz_full_enabled()) | |
4275 | unaccount_freq_event_nohz(); | |
4276 | else | |
4277 | atomic_dec(&nr_freq_events); | |
4278 | } | |
4279 | ||
4beb31f3 FW |
4280 | static void unaccount_event(struct perf_event *event) |
4281 | { | |
25432ae9 PZ |
4282 | bool dec = false; |
4283 | ||
4beb31f3 FW |
4284 | if (event->parent) |
4285 | return; | |
4286 | ||
4287 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 4288 | dec = true; |
4beb31f3 FW |
4289 | if (event->attr.mmap || event->attr.mmap_data) |
4290 | atomic_dec(&nr_mmap_events); | |
4291 | if (event->attr.comm) | |
4292 | atomic_dec(&nr_comm_events); | |
e4222673 HB |
4293 | if (event->attr.namespaces) |
4294 | atomic_dec(&nr_namespaces_events); | |
4beb31f3 FW |
4295 | if (event->attr.task) |
4296 | atomic_dec(&nr_task_events); | |
948b26b6 | 4297 | if (event->attr.freq) |
555e0c1e | 4298 | unaccount_freq_event(); |
45ac1403 | 4299 | if (event->attr.context_switch) { |
25432ae9 | 4300 | dec = true; |
45ac1403 AH |
4301 | atomic_dec(&nr_switch_events); |
4302 | } | |
4beb31f3 | 4303 | if (is_cgroup_event(event)) |
25432ae9 | 4304 | dec = true; |
4beb31f3 | 4305 | if (has_branch_stack(event)) |
25432ae9 PZ |
4306 | dec = true; |
4307 | ||
9107c89e PZ |
4308 | if (dec) { |
4309 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
4310 | schedule_delayed_work(&perf_sched_work, HZ); | |
4311 | } | |
4beb31f3 FW |
4312 | |
4313 | unaccount_event_cpu(event, event->cpu); | |
f2fb6bef KL |
4314 | |
4315 | unaccount_pmu_sb_event(event); | |
4beb31f3 | 4316 | } |
925d519a | 4317 | |
9107c89e PZ |
4318 | static void perf_sched_delayed(struct work_struct *work) |
4319 | { | |
4320 | mutex_lock(&perf_sched_mutex); | |
4321 | if (atomic_dec_and_test(&perf_sched_count)) | |
4322 | static_branch_disable(&perf_sched_events); | |
4323 | mutex_unlock(&perf_sched_mutex); | |
4324 | } | |
4325 | ||
bed5b25a AS |
4326 | /* |
4327 | * The following implement mutual exclusion of events on "exclusive" pmus | |
4328 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
4329 | * at a time, so we disallow creating events that might conflict, namely: | |
4330 | * | |
4331 | * 1) cpu-wide events in the presence of per-task events, | |
4332 | * 2) per-task events in the presence of cpu-wide events, | |
4333 | * 3) two matching events on the same context. | |
4334 | * | |
4335 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 4336 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
4337 | */ |
4338 | static int exclusive_event_init(struct perf_event *event) | |
4339 | { | |
4340 | struct pmu *pmu = event->pmu; | |
4341 | ||
4342 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4343 | return 0; | |
4344 | ||
4345 | /* | |
4346 | * Prevent co-existence of per-task and cpu-wide events on the | |
4347 | * same exclusive pmu. | |
4348 | * | |
4349 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
4350 | * events on this "exclusive" pmu, positive means there are | |
4351 | * per-task events. | |
4352 | * | |
4353 | * Since this is called in perf_event_alloc() path, event::ctx | |
4354 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
4355 | * to mean "per-task event", because unlike other attach states it | |
4356 | * never gets cleared. | |
4357 | */ | |
4358 | if (event->attach_state & PERF_ATTACH_TASK) { | |
4359 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
4360 | return -EBUSY; | |
4361 | } else { | |
4362 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
4363 | return -EBUSY; | |
4364 | } | |
4365 | ||
4366 | return 0; | |
4367 | } | |
4368 | ||
4369 | static void exclusive_event_destroy(struct perf_event *event) | |
4370 | { | |
4371 | struct pmu *pmu = event->pmu; | |
4372 | ||
4373 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4374 | return; | |
4375 | ||
4376 | /* see comment in exclusive_event_init() */ | |
4377 | if (event->attach_state & PERF_ATTACH_TASK) | |
4378 | atomic_dec(&pmu->exclusive_cnt); | |
4379 | else | |
4380 | atomic_inc(&pmu->exclusive_cnt); | |
4381 | } | |
4382 | ||
4383 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
4384 | { | |
3bf6215a | 4385 | if ((e1->pmu == e2->pmu) && |
bed5b25a AS |
4386 | (e1->cpu == e2->cpu || |
4387 | e1->cpu == -1 || | |
4388 | e2->cpu == -1)) | |
4389 | return true; | |
4390 | return false; | |
4391 | } | |
4392 | ||
4393 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
4394 | static bool exclusive_event_installable(struct perf_event *event, | |
4395 | struct perf_event_context *ctx) | |
4396 | { | |
4397 | struct perf_event *iter_event; | |
4398 | struct pmu *pmu = event->pmu; | |
4399 | ||
4400 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4401 | return true; | |
4402 | ||
4403 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
4404 | if (exclusive_event_match(iter_event, event)) | |
4405 | return false; | |
4406 | } | |
4407 | ||
4408 | return true; | |
4409 | } | |
4410 | ||
375637bc AS |
4411 | static void perf_addr_filters_splice(struct perf_event *event, |
4412 | struct list_head *head); | |
4413 | ||
683ede43 | 4414 | static void _free_event(struct perf_event *event) |
f1600952 | 4415 | { |
e360adbe | 4416 | irq_work_sync(&event->pending); |
925d519a | 4417 | |
4beb31f3 | 4418 | unaccount_event(event); |
9ee318a7 | 4419 | |
76369139 | 4420 | if (event->rb) { |
9bb5d40c PZ |
4421 | /* |
4422 | * Can happen when we close an event with re-directed output. | |
4423 | * | |
4424 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
4425 | * over us; possibly making our ring_buffer_put() the last. | |
4426 | */ | |
4427 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 4428 | ring_buffer_attach(event, NULL); |
9bb5d40c | 4429 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
4430 | } |
4431 | ||
e5d1367f SE |
4432 | if (is_cgroup_event(event)) |
4433 | perf_detach_cgroup(event); | |
4434 | ||
a0733e69 PZ |
4435 | if (!event->parent) { |
4436 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
4437 | put_callchain_buffers(); | |
4438 | } | |
4439 | ||
4440 | perf_event_free_bpf_prog(event); | |
375637bc AS |
4441 | perf_addr_filters_splice(event, NULL); |
4442 | kfree(event->addr_filters_offs); | |
a0733e69 PZ |
4443 | |
4444 | if (event->destroy) | |
4445 | event->destroy(event); | |
4446 | ||
4447 | if (event->ctx) | |
4448 | put_ctx(event->ctx); | |
4449 | ||
621b6d2e PB |
4450 | if (event->hw.target) |
4451 | put_task_struct(event->hw.target); | |
4452 | ||
62a92c8f AS |
4453 | exclusive_event_destroy(event); |
4454 | module_put(event->pmu->module); | |
a0733e69 PZ |
4455 | |
4456 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
4457 | } |
4458 | ||
683ede43 PZ |
4459 | /* |
4460 | * Used to free events which have a known refcount of 1, such as in error paths | |
4461 | * where the event isn't exposed yet and inherited events. | |
4462 | */ | |
4463 | static void free_event(struct perf_event *event) | |
0793a61d | 4464 | { |
683ede43 PZ |
4465 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
4466 | "unexpected event refcount: %ld; ptr=%p\n", | |
4467 | atomic_long_read(&event->refcount), event)) { | |
4468 | /* leak to avoid use-after-free */ | |
4469 | return; | |
4470 | } | |
0793a61d | 4471 | |
683ede43 | 4472 | _free_event(event); |
0793a61d TG |
4473 | } |
4474 | ||
a66a3052 | 4475 | /* |
f8697762 | 4476 | * Remove user event from the owner task. |
a66a3052 | 4477 | */ |
f8697762 | 4478 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 4479 | { |
8882135b | 4480 | struct task_struct *owner; |
fb0459d7 | 4481 | |
8882135b | 4482 | rcu_read_lock(); |
8882135b | 4483 | /* |
f47c02c0 PZ |
4484 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
4485 | * observe !owner it means the list deletion is complete and we can | |
4486 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
4487 | * owner->perf_event_mutex. |
4488 | */ | |
506458ef | 4489 | owner = READ_ONCE(event->owner); |
8882135b PZ |
4490 | if (owner) { |
4491 | /* | |
4492 | * Since delayed_put_task_struct() also drops the last | |
4493 | * task reference we can safely take a new reference | |
4494 | * while holding the rcu_read_lock(). | |
4495 | */ | |
4496 | get_task_struct(owner); | |
4497 | } | |
4498 | rcu_read_unlock(); | |
4499 | ||
4500 | if (owner) { | |
f63a8daa PZ |
4501 | /* |
4502 | * If we're here through perf_event_exit_task() we're already | |
4503 | * holding ctx->mutex which would be an inversion wrt. the | |
4504 | * normal lock order. | |
4505 | * | |
4506 | * However we can safely take this lock because its the child | |
4507 | * ctx->mutex. | |
4508 | */ | |
4509 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
4510 | ||
8882135b PZ |
4511 | /* |
4512 | * We have to re-check the event->owner field, if it is cleared | |
4513 | * we raced with perf_event_exit_task(), acquiring the mutex | |
4514 | * ensured they're done, and we can proceed with freeing the | |
4515 | * event. | |
4516 | */ | |
f47c02c0 | 4517 | if (event->owner) { |
8882135b | 4518 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
4519 | smp_store_release(&event->owner, NULL); |
4520 | } | |
8882135b PZ |
4521 | mutex_unlock(&owner->perf_event_mutex); |
4522 | put_task_struct(owner); | |
4523 | } | |
f8697762 JO |
4524 | } |
4525 | ||
f8697762 JO |
4526 | static void put_event(struct perf_event *event) |
4527 | { | |
f8697762 JO |
4528 | if (!atomic_long_dec_and_test(&event->refcount)) |
4529 | return; | |
4530 | ||
c6e5b732 PZ |
4531 | _free_event(event); |
4532 | } | |
4533 | ||
4534 | /* | |
4535 | * Kill an event dead; while event:refcount will preserve the event | |
4536 | * object, it will not preserve its functionality. Once the last 'user' | |
4537 | * gives up the object, we'll destroy the thing. | |
4538 | */ | |
4539 | int perf_event_release_kernel(struct perf_event *event) | |
4540 | { | |
a4f4bb6d | 4541 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 | 4542 | struct perf_event *child, *tmp; |
82d94856 | 4543 | LIST_HEAD(free_list); |
c6e5b732 | 4544 | |
a4f4bb6d PZ |
4545 | /* |
4546 | * If we got here through err_file: fput(event_file); we will not have | |
4547 | * attached to a context yet. | |
4548 | */ | |
4549 | if (!ctx) { | |
4550 | WARN_ON_ONCE(event->attach_state & | |
4551 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
4552 | goto no_ctx; | |
4553 | } | |
4554 | ||
f8697762 JO |
4555 | if (!is_kernel_event(event)) |
4556 | perf_remove_from_owner(event); | |
8882135b | 4557 | |
5fa7c8ec | 4558 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 4559 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 4560 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 4561 | |
a69b0ca4 | 4562 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 4563 | /* |
d8a8cfc7 | 4564 | * Mark this event as STATE_DEAD, there is no external reference to it |
a69b0ca4 | 4565 | * anymore. |
683ede43 | 4566 | * |
a69b0ca4 PZ |
4567 | * Anybody acquiring event->child_mutex after the below loop _must_ |
4568 | * also see this, most importantly inherit_event() which will avoid | |
4569 | * placing more children on the list. | |
683ede43 | 4570 | * |
c6e5b732 PZ |
4571 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
4572 | * child events. | |
683ede43 | 4573 | */ |
a69b0ca4 PZ |
4574 | event->state = PERF_EVENT_STATE_DEAD; |
4575 | raw_spin_unlock_irq(&ctx->lock); | |
4576 | ||
4577 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 4578 | |
c6e5b732 PZ |
4579 | again: |
4580 | mutex_lock(&event->child_mutex); | |
4581 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 4582 | |
c6e5b732 PZ |
4583 | /* |
4584 | * Cannot change, child events are not migrated, see the | |
4585 | * comment with perf_event_ctx_lock_nested(). | |
4586 | */ | |
506458ef | 4587 | ctx = READ_ONCE(child->ctx); |
c6e5b732 PZ |
4588 | /* |
4589 | * Since child_mutex nests inside ctx::mutex, we must jump | |
4590 | * through hoops. We start by grabbing a reference on the ctx. | |
4591 | * | |
4592 | * Since the event cannot get freed while we hold the | |
4593 | * child_mutex, the context must also exist and have a !0 | |
4594 | * reference count. | |
4595 | */ | |
4596 | get_ctx(ctx); | |
4597 | ||
4598 | /* | |
4599 | * Now that we have a ctx ref, we can drop child_mutex, and | |
4600 | * acquire ctx::mutex without fear of it going away. Then we | |
4601 | * can re-acquire child_mutex. | |
4602 | */ | |
4603 | mutex_unlock(&event->child_mutex); | |
4604 | mutex_lock(&ctx->mutex); | |
4605 | mutex_lock(&event->child_mutex); | |
4606 | ||
4607 | /* | |
4608 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
4609 | * state, if child is still the first entry, it didn't get freed | |
4610 | * and we can continue doing so. | |
4611 | */ | |
4612 | tmp = list_first_entry_or_null(&event->child_list, | |
4613 | struct perf_event, child_list); | |
4614 | if (tmp == child) { | |
4615 | perf_remove_from_context(child, DETACH_GROUP); | |
82d94856 | 4616 | list_move(&child->child_list, &free_list); |
c6e5b732 PZ |
4617 | /* |
4618 | * This matches the refcount bump in inherit_event(); | |
4619 | * this can't be the last reference. | |
4620 | */ | |
4621 | put_event(event); | |
4622 | } | |
4623 | ||
4624 | mutex_unlock(&event->child_mutex); | |
4625 | mutex_unlock(&ctx->mutex); | |
4626 | put_ctx(ctx); | |
4627 | goto again; | |
4628 | } | |
4629 | mutex_unlock(&event->child_mutex); | |
4630 | ||
82d94856 PZ |
4631 | list_for_each_entry_safe(child, tmp, &free_list, child_list) { |
4632 | list_del(&child->child_list); | |
4633 | free_event(child); | |
4634 | } | |
4635 | ||
a4f4bb6d PZ |
4636 | no_ctx: |
4637 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
4638 | return 0; |
4639 | } | |
4640 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
4641 | ||
8b10c5e2 PZ |
4642 | /* |
4643 | * Called when the last reference to the file is gone. | |
4644 | */ | |
a6fa941d AV |
4645 | static int perf_release(struct inode *inode, struct file *file) |
4646 | { | |
c6e5b732 | 4647 | perf_event_release_kernel(file->private_data); |
a6fa941d | 4648 | return 0; |
fb0459d7 | 4649 | } |
fb0459d7 | 4650 | |
ca0dd44c | 4651 | static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 4652 | { |
cdd6c482 | 4653 | struct perf_event *child; |
e53c0994 PZ |
4654 | u64 total = 0; |
4655 | ||
59ed446f PZ |
4656 | *enabled = 0; |
4657 | *running = 0; | |
4658 | ||
6f10581a | 4659 | mutex_lock(&event->child_mutex); |
01add3ea | 4660 | |
7d88962e | 4661 | (void)perf_event_read(event, false); |
01add3ea SB |
4662 | total += perf_event_count(event); |
4663 | ||
59ed446f PZ |
4664 | *enabled += event->total_time_enabled + |
4665 | atomic64_read(&event->child_total_time_enabled); | |
4666 | *running += event->total_time_running + | |
4667 | atomic64_read(&event->child_total_time_running); | |
4668 | ||
4669 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 4670 | (void)perf_event_read(child, false); |
01add3ea | 4671 | total += perf_event_count(child); |
59ed446f PZ |
4672 | *enabled += child->total_time_enabled; |
4673 | *running += child->total_time_running; | |
4674 | } | |
6f10581a | 4675 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
4676 | |
4677 | return total; | |
4678 | } | |
ca0dd44c PZ |
4679 | |
4680 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) | |
4681 | { | |
4682 | struct perf_event_context *ctx; | |
4683 | u64 count; | |
4684 | ||
4685 | ctx = perf_event_ctx_lock(event); | |
4686 | count = __perf_event_read_value(event, enabled, running); | |
4687 | perf_event_ctx_unlock(event, ctx); | |
4688 | ||
4689 | return count; | |
4690 | } | |
fb0459d7 | 4691 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 4692 | |
7d88962e | 4693 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 4694 | u64 read_format, u64 *values) |
3dab77fb | 4695 | { |
2aeb1883 | 4696 | struct perf_event_context *ctx = leader->ctx; |
fa8c2693 | 4697 | struct perf_event *sub; |
2aeb1883 | 4698 | unsigned long flags; |
fa8c2693 | 4699 | int n = 1; /* skip @nr */ |
7d88962e | 4700 | int ret; |
f63a8daa | 4701 | |
7d88962e SB |
4702 | ret = perf_event_read(leader, true); |
4703 | if (ret) | |
4704 | return ret; | |
abf4868b | 4705 | |
a9cd8194 PZ |
4706 | raw_spin_lock_irqsave(&ctx->lock, flags); |
4707 | ||
fa8c2693 PZ |
4708 | /* |
4709 | * Since we co-schedule groups, {enabled,running} times of siblings | |
4710 | * will be identical to those of the leader, so we only publish one | |
4711 | * set. | |
4712 | */ | |
4713 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
4714 | values[n++] += leader->total_time_enabled + | |
4715 | atomic64_read(&leader->child_total_time_enabled); | |
4716 | } | |
3dab77fb | 4717 | |
fa8c2693 PZ |
4718 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
4719 | values[n++] += leader->total_time_running + | |
4720 | atomic64_read(&leader->child_total_time_running); | |
4721 | } | |
4722 | ||
4723 | /* | |
4724 | * Write {count,id} tuples for every sibling. | |
4725 | */ | |
4726 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
4727 | if (read_format & PERF_FORMAT_ID) |
4728 | values[n++] = primary_event_id(leader); | |
3dab77fb | 4729 | |
edb39592 | 4730 | for_each_sibling_event(sub, leader) { |
fa8c2693 PZ |
4731 | values[n++] += perf_event_count(sub); |
4732 | if (read_format & PERF_FORMAT_ID) | |
4733 | values[n++] = primary_event_id(sub); | |
4734 | } | |
7d88962e | 4735 | |
2aeb1883 | 4736 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
7d88962e | 4737 | return 0; |
fa8c2693 | 4738 | } |
3dab77fb | 4739 | |
fa8c2693 PZ |
4740 | static int perf_read_group(struct perf_event *event, |
4741 | u64 read_format, char __user *buf) | |
4742 | { | |
4743 | struct perf_event *leader = event->group_leader, *child; | |
4744 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 4745 | int ret; |
fa8c2693 | 4746 | u64 *values; |
3dab77fb | 4747 | |
fa8c2693 | 4748 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 4749 | |
fa8c2693 PZ |
4750 | values = kzalloc(event->read_size, GFP_KERNEL); |
4751 | if (!values) | |
4752 | return -ENOMEM; | |
3dab77fb | 4753 | |
fa8c2693 PZ |
4754 | values[0] = 1 + leader->nr_siblings; |
4755 | ||
4756 | /* | |
4757 | * By locking the child_mutex of the leader we effectively | |
4758 | * lock the child list of all siblings.. XXX explain how. | |
4759 | */ | |
4760 | mutex_lock(&leader->child_mutex); | |
abf4868b | 4761 | |
7d88962e SB |
4762 | ret = __perf_read_group_add(leader, read_format, values); |
4763 | if (ret) | |
4764 | goto unlock; | |
4765 | ||
4766 | list_for_each_entry(child, &leader->child_list, child_list) { | |
4767 | ret = __perf_read_group_add(child, read_format, values); | |
4768 | if (ret) | |
4769 | goto unlock; | |
4770 | } | |
abf4868b | 4771 | |
fa8c2693 | 4772 | mutex_unlock(&leader->child_mutex); |
abf4868b | 4773 | |
7d88962e | 4774 | ret = event->read_size; |
fa8c2693 PZ |
4775 | if (copy_to_user(buf, values, event->read_size)) |
4776 | ret = -EFAULT; | |
7d88962e | 4777 | goto out; |
fa8c2693 | 4778 | |
7d88962e SB |
4779 | unlock: |
4780 | mutex_unlock(&leader->child_mutex); | |
4781 | out: | |
fa8c2693 | 4782 | kfree(values); |
abf4868b | 4783 | return ret; |
3dab77fb PZ |
4784 | } |
4785 | ||
b15f495b | 4786 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4787 | u64 read_format, char __user *buf) |
4788 | { | |
59ed446f | 4789 | u64 enabled, running; |
3dab77fb PZ |
4790 | u64 values[4]; |
4791 | int n = 0; | |
4792 | ||
ca0dd44c | 4793 | values[n++] = __perf_event_read_value(event, &enabled, &running); |
59ed446f PZ |
4794 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
4795 | values[n++] = enabled; | |
4796 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4797 | values[n++] = running; | |
3dab77fb | 4798 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4799 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4800 | |
4801 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4802 | return -EFAULT; | |
4803 | ||
4804 | return n * sizeof(u64); | |
4805 | } | |
4806 | ||
dc633982 JO |
4807 | static bool is_event_hup(struct perf_event *event) |
4808 | { | |
4809 | bool no_children; | |
4810 | ||
a69b0ca4 | 4811 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4812 | return false; |
4813 | ||
4814 | mutex_lock(&event->child_mutex); | |
4815 | no_children = list_empty(&event->child_list); | |
4816 | mutex_unlock(&event->child_mutex); | |
4817 | return no_children; | |
4818 | } | |
4819 | ||
0793a61d | 4820 | /* |
cdd6c482 | 4821 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4822 | */ |
4823 | static ssize_t | |
b15f495b | 4824 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4825 | { |
cdd6c482 | 4826 | u64 read_format = event->attr.read_format; |
3dab77fb | 4827 | int ret; |
0793a61d | 4828 | |
3b6f9e5c | 4829 | /* |
cdd6c482 | 4830 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4831 | * error state (i.e. because it was pinned but it couldn't be |
4832 | * scheduled on to the CPU at some point). | |
4833 | */ | |
cdd6c482 | 4834 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4835 | return 0; |
4836 | ||
c320c7b7 | 4837 | if (count < event->read_size) |
3dab77fb PZ |
4838 | return -ENOSPC; |
4839 | ||
cdd6c482 | 4840 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4841 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4842 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4843 | else |
b15f495b | 4844 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4845 | |
3dab77fb | 4846 | return ret; |
0793a61d TG |
4847 | } |
4848 | ||
0793a61d TG |
4849 | static ssize_t |
4850 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4851 | { | |
cdd6c482 | 4852 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4853 | struct perf_event_context *ctx; |
4854 | int ret; | |
0793a61d | 4855 | |
f63a8daa | 4856 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4857 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4858 | perf_event_ctx_unlock(event, ctx); |
4859 | ||
4860 | return ret; | |
0793a61d TG |
4861 | } |
4862 | ||
9dd95748 | 4863 | static __poll_t perf_poll(struct file *file, poll_table *wait) |
0793a61d | 4864 | { |
cdd6c482 | 4865 | struct perf_event *event = file->private_data; |
76369139 | 4866 | struct ring_buffer *rb; |
a9a08845 | 4867 | __poll_t events = EPOLLHUP; |
c7138f37 | 4868 | |
e708d7ad | 4869 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4870 | |
dc633982 | 4871 | if (is_event_hup(event)) |
179033b3 | 4872 | return events; |
c7138f37 | 4873 | |
10c6db11 | 4874 | /* |
9bb5d40c PZ |
4875 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4876 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4877 | */ |
4878 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4879 | rb = event->rb; |
4880 | if (rb) | |
76369139 | 4881 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4882 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4883 | return events; |
4884 | } | |
4885 | ||
f63a8daa | 4886 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4887 | { |
7d88962e | 4888 | (void)perf_event_read(event, false); |
e7850595 | 4889 | local64_set(&event->count, 0); |
cdd6c482 | 4890 | perf_event_update_userpage(event); |
3df5edad PZ |
4891 | } |
4892 | ||
c93f7669 | 4893 | /* |
cdd6c482 IM |
4894 | * Holding the top-level event's child_mutex means that any |
4895 | * descendant process that has inherited this event will block | |
8ba289b8 | 4896 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4897 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4898 | */ |
cdd6c482 IM |
4899 | static void perf_event_for_each_child(struct perf_event *event, |
4900 | void (*func)(struct perf_event *)) | |
3df5edad | 4901 | { |
cdd6c482 | 4902 | struct perf_event *child; |
3df5edad | 4903 | |
cdd6c482 | 4904 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4905 | |
cdd6c482 IM |
4906 | mutex_lock(&event->child_mutex); |
4907 | func(event); | |
4908 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4909 | func(child); |
cdd6c482 | 4910 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4911 | } |
4912 | ||
cdd6c482 IM |
4913 | static void perf_event_for_each(struct perf_event *event, |
4914 | void (*func)(struct perf_event *)) | |
3df5edad | 4915 | { |
cdd6c482 IM |
4916 | struct perf_event_context *ctx = event->ctx; |
4917 | struct perf_event *sibling; | |
3df5edad | 4918 | |
f63a8daa PZ |
4919 | lockdep_assert_held(&ctx->mutex); |
4920 | ||
cdd6c482 | 4921 | event = event->group_leader; |
75f937f2 | 4922 | |
cdd6c482 | 4923 | perf_event_for_each_child(event, func); |
edb39592 | 4924 | for_each_sibling_event(sibling, event) |
724b6daa | 4925 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4926 | } |
4927 | ||
fae3fde6 PZ |
4928 | static void __perf_event_period(struct perf_event *event, |
4929 | struct perf_cpu_context *cpuctx, | |
4930 | struct perf_event_context *ctx, | |
4931 | void *info) | |
c7999c6f | 4932 | { |
fae3fde6 | 4933 | u64 value = *((u64 *)info); |
c7999c6f | 4934 | bool active; |
08247e31 | 4935 | |
cdd6c482 | 4936 | if (event->attr.freq) { |
cdd6c482 | 4937 | event->attr.sample_freq = value; |
08247e31 | 4938 | } else { |
cdd6c482 IM |
4939 | event->attr.sample_period = value; |
4940 | event->hw.sample_period = value; | |
08247e31 | 4941 | } |
bad7192b PZ |
4942 | |
4943 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4944 | if (active) { | |
4945 | perf_pmu_disable(ctx->pmu); | |
1e02cd40 PZ |
4946 | /* |
4947 | * We could be throttled; unthrottle now to avoid the tick | |
4948 | * trying to unthrottle while we already re-started the event. | |
4949 | */ | |
4950 | if (event->hw.interrupts == MAX_INTERRUPTS) { | |
4951 | event->hw.interrupts = 0; | |
4952 | perf_log_throttle(event, 1); | |
4953 | } | |
bad7192b PZ |
4954 | event->pmu->stop(event, PERF_EF_UPDATE); |
4955 | } | |
4956 | ||
4957 | local64_set(&event->hw.period_left, 0); | |
4958 | ||
4959 | if (active) { | |
4960 | event->pmu->start(event, PERF_EF_RELOAD); | |
4961 | perf_pmu_enable(ctx->pmu); | |
4962 | } | |
c7999c6f PZ |
4963 | } |
4964 | ||
4965 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4966 | { | |
c7999c6f PZ |
4967 | u64 value; |
4968 | ||
4969 | if (!is_sampling_event(event)) | |
4970 | return -EINVAL; | |
4971 | ||
4972 | if (copy_from_user(&value, arg, sizeof(value))) | |
4973 | return -EFAULT; | |
4974 | ||
4975 | if (!value) | |
4976 | return -EINVAL; | |
4977 | ||
4978 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4979 | return -EINVAL; | |
4980 | ||
fae3fde6 | 4981 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4982 | |
c7999c6f | 4983 | return 0; |
08247e31 PZ |
4984 | } |
4985 | ||
ac9721f3 PZ |
4986 | static const struct file_operations perf_fops; |
4987 | ||
2903ff01 | 4988 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4989 | { |
2903ff01 AV |
4990 | struct fd f = fdget(fd); |
4991 | if (!f.file) | |
4992 | return -EBADF; | |
ac9721f3 | 4993 | |
2903ff01 AV |
4994 | if (f.file->f_op != &perf_fops) { |
4995 | fdput(f); | |
4996 | return -EBADF; | |
ac9721f3 | 4997 | } |
2903ff01 AV |
4998 | *p = f; |
4999 | return 0; | |
ac9721f3 PZ |
5000 | } |
5001 | ||
5002 | static int perf_event_set_output(struct perf_event *event, | |
5003 | struct perf_event *output_event); | |
6fb2915d | 5004 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 5005 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
32ff77e8 MC |
5006 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
5007 | struct perf_event_attr *attr); | |
a4be7c27 | 5008 | |
f63a8daa | 5009 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 5010 | { |
cdd6c482 | 5011 | void (*func)(struct perf_event *); |
3df5edad | 5012 | u32 flags = arg; |
d859e29f PM |
5013 | |
5014 | switch (cmd) { | |
cdd6c482 | 5015 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 5016 | func = _perf_event_enable; |
d859e29f | 5017 | break; |
cdd6c482 | 5018 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 5019 | func = _perf_event_disable; |
79f14641 | 5020 | break; |
cdd6c482 | 5021 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 5022 | func = _perf_event_reset; |
6de6a7b9 | 5023 | break; |
3df5edad | 5024 | |
cdd6c482 | 5025 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 5026 | return _perf_event_refresh(event, arg); |
08247e31 | 5027 | |
cdd6c482 IM |
5028 | case PERF_EVENT_IOC_PERIOD: |
5029 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 5030 | |
cf4957f1 JO |
5031 | case PERF_EVENT_IOC_ID: |
5032 | { | |
5033 | u64 id = primary_event_id(event); | |
5034 | ||
5035 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
5036 | return -EFAULT; | |
5037 | return 0; | |
5038 | } | |
5039 | ||
cdd6c482 | 5040 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 5041 | { |
ac9721f3 | 5042 | int ret; |
ac9721f3 | 5043 | if (arg != -1) { |
2903ff01 AV |
5044 | struct perf_event *output_event; |
5045 | struct fd output; | |
5046 | ret = perf_fget_light(arg, &output); | |
5047 | if (ret) | |
5048 | return ret; | |
5049 | output_event = output.file->private_data; | |
5050 | ret = perf_event_set_output(event, output_event); | |
5051 | fdput(output); | |
5052 | } else { | |
5053 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 5054 | } |
ac9721f3 PZ |
5055 | return ret; |
5056 | } | |
a4be7c27 | 5057 | |
6fb2915d LZ |
5058 | case PERF_EVENT_IOC_SET_FILTER: |
5059 | return perf_event_set_filter(event, (void __user *)arg); | |
5060 | ||
2541517c AS |
5061 | case PERF_EVENT_IOC_SET_BPF: |
5062 | return perf_event_set_bpf_prog(event, arg); | |
5063 | ||
86e7972f WN |
5064 | case PERF_EVENT_IOC_PAUSE_OUTPUT: { |
5065 | struct ring_buffer *rb; | |
5066 | ||
5067 | rcu_read_lock(); | |
5068 | rb = rcu_dereference(event->rb); | |
5069 | if (!rb || !rb->nr_pages) { | |
5070 | rcu_read_unlock(); | |
5071 | return -EINVAL; | |
5072 | } | |
5073 | rb_toggle_paused(rb, !!arg); | |
5074 | rcu_read_unlock(); | |
5075 | return 0; | |
5076 | } | |
f371b304 YS |
5077 | |
5078 | case PERF_EVENT_IOC_QUERY_BPF: | |
f4e2298e | 5079 | return perf_event_query_prog_array(event, (void __user *)arg); |
32ff77e8 MC |
5080 | |
5081 | case PERF_EVENT_IOC_MODIFY_ATTRIBUTES: { | |
5082 | struct perf_event_attr new_attr; | |
5083 | int err = perf_copy_attr((struct perf_event_attr __user *)arg, | |
5084 | &new_attr); | |
5085 | ||
5086 | if (err) | |
5087 | return err; | |
5088 | ||
5089 | return perf_event_modify_attr(event, &new_attr); | |
5090 | } | |
d859e29f | 5091 | default: |
3df5edad | 5092 | return -ENOTTY; |
d859e29f | 5093 | } |
3df5edad PZ |
5094 | |
5095 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 5096 | perf_event_for_each(event, func); |
3df5edad | 5097 | else |
cdd6c482 | 5098 | perf_event_for_each_child(event, func); |
3df5edad PZ |
5099 | |
5100 | return 0; | |
d859e29f PM |
5101 | } |
5102 | ||
f63a8daa PZ |
5103 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
5104 | { | |
5105 | struct perf_event *event = file->private_data; | |
5106 | struct perf_event_context *ctx; | |
5107 | long ret; | |
5108 | ||
5109 | ctx = perf_event_ctx_lock(event); | |
5110 | ret = _perf_ioctl(event, cmd, arg); | |
5111 | perf_event_ctx_unlock(event, ctx); | |
5112 | ||
5113 | return ret; | |
5114 | } | |
5115 | ||
b3f20785 PM |
5116 | #ifdef CONFIG_COMPAT |
5117 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
5118 | unsigned long arg) | |
5119 | { | |
5120 | switch (_IOC_NR(cmd)) { | |
5121 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
5122 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
82489c5f ES |
5123 | case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF): |
5124 | case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES): | |
b3f20785 PM |
5125 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ |
5126 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
5127 | cmd &= ~IOCSIZE_MASK; | |
5128 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
5129 | } | |
5130 | break; | |
5131 | } | |
5132 | return perf_ioctl(file, cmd, arg); | |
5133 | } | |
5134 | #else | |
5135 | # define perf_compat_ioctl NULL | |
5136 | #endif | |
5137 | ||
cdd6c482 | 5138 | int perf_event_task_enable(void) |
771d7cde | 5139 | { |
f63a8daa | 5140 | struct perf_event_context *ctx; |
cdd6c482 | 5141 | struct perf_event *event; |
771d7cde | 5142 | |
cdd6c482 | 5143 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
5144 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
5145 | ctx = perf_event_ctx_lock(event); | |
5146 | perf_event_for_each_child(event, _perf_event_enable); | |
5147 | perf_event_ctx_unlock(event, ctx); | |
5148 | } | |
cdd6c482 | 5149 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
5150 | |
5151 | return 0; | |
5152 | } | |
5153 | ||
cdd6c482 | 5154 | int perf_event_task_disable(void) |
771d7cde | 5155 | { |
f63a8daa | 5156 | struct perf_event_context *ctx; |
cdd6c482 | 5157 | struct perf_event *event; |
771d7cde | 5158 | |
cdd6c482 | 5159 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
5160 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
5161 | ctx = perf_event_ctx_lock(event); | |
5162 | perf_event_for_each_child(event, _perf_event_disable); | |
5163 | perf_event_ctx_unlock(event, ctx); | |
5164 | } | |
cdd6c482 | 5165 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
5166 | |
5167 | return 0; | |
5168 | } | |
5169 | ||
cdd6c482 | 5170 | static int perf_event_index(struct perf_event *event) |
194002b2 | 5171 | { |
a4eaf7f1 PZ |
5172 | if (event->hw.state & PERF_HES_STOPPED) |
5173 | return 0; | |
5174 | ||
cdd6c482 | 5175 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
5176 | return 0; |
5177 | ||
35edc2a5 | 5178 | return event->pmu->event_idx(event); |
194002b2 PZ |
5179 | } |
5180 | ||
c4794295 | 5181 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 5182 | u64 *now, |
7f310a5d EM |
5183 | u64 *enabled, |
5184 | u64 *running) | |
c4794295 | 5185 | { |
e3f3541c | 5186 | u64 ctx_time; |
c4794295 | 5187 | |
e3f3541c PZ |
5188 | *now = perf_clock(); |
5189 | ctx_time = event->shadow_ctx_time + *now; | |
0d3d73aa | 5190 | __perf_update_times(event, ctx_time, enabled, running); |
c4794295 EM |
5191 | } |
5192 | ||
fa731587 PZ |
5193 | static void perf_event_init_userpage(struct perf_event *event) |
5194 | { | |
5195 | struct perf_event_mmap_page *userpg; | |
5196 | struct ring_buffer *rb; | |
5197 | ||
5198 | rcu_read_lock(); | |
5199 | rb = rcu_dereference(event->rb); | |
5200 | if (!rb) | |
5201 | goto unlock; | |
5202 | ||
5203 | userpg = rb->user_page; | |
5204 | ||
5205 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
5206 | userpg->cap_bit0_is_deprecated = 1; | |
5207 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
5208 | userpg->data_offset = PAGE_SIZE; |
5209 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
5210 | |
5211 | unlock: | |
5212 | rcu_read_unlock(); | |
5213 | } | |
5214 | ||
c1317ec2 AL |
5215 | void __weak arch_perf_update_userpage( |
5216 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
5217 | { |
5218 | } | |
5219 | ||
38ff667b PZ |
5220 | /* |
5221 | * Callers need to ensure there can be no nesting of this function, otherwise | |
5222 | * the seqlock logic goes bad. We can not serialize this because the arch | |
5223 | * code calls this from NMI context. | |
5224 | */ | |
cdd6c482 | 5225 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 5226 | { |
cdd6c482 | 5227 | struct perf_event_mmap_page *userpg; |
76369139 | 5228 | struct ring_buffer *rb; |
e3f3541c | 5229 | u64 enabled, running, now; |
38ff667b PZ |
5230 | |
5231 | rcu_read_lock(); | |
5ec4c599 PZ |
5232 | rb = rcu_dereference(event->rb); |
5233 | if (!rb) | |
5234 | goto unlock; | |
5235 | ||
0d641208 EM |
5236 | /* |
5237 | * compute total_time_enabled, total_time_running | |
5238 | * based on snapshot values taken when the event | |
5239 | * was last scheduled in. | |
5240 | * | |
5241 | * we cannot simply called update_context_time() | |
5242 | * because of locking issue as we can be called in | |
5243 | * NMI context | |
5244 | */ | |
e3f3541c | 5245 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 5246 | |
76369139 | 5247 | userpg = rb->user_page; |
7b732a75 PZ |
5248 | /* |
5249 | * Disable preemption so as to not let the corresponding user-space | |
5250 | * spin too long if we get preempted. | |
5251 | */ | |
5252 | preempt_disable(); | |
37d81828 | 5253 | ++userpg->lock; |
92f22a38 | 5254 | barrier(); |
cdd6c482 | 5255 | userpg->index = perf_event_index(event); |
b5e58793 | 5256 | userpg->offset = perf_event_count(event); |
365a4038 | 5257 | if (userpg->index) |
e7850595 | 5258 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 5259 | |
0d641208 | 5260 | userpg->time_enabled = enabled + |
cdd6c482 | 5261 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 5262 | |
0d641208 | 5263 | userpg->time_running = running + |
cdd6c482 | 5264 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 5265 | |
c1317ec2 | 5266 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 5267 | |
92f22a38 | 5268 | barrier(); |
37d81828 | 5269 | ++userpg->lock; |
7b732a75 | 5270 | preempt_enable(); |
38ff667b | 5271 | unlock: |
7b732a75 | 5272 | rcu_read_unlock(); |
37d81828 | 5273 | } |
82975c46 | 5274 | EXPORT_SYMBOL_GPL(perf_event_update_userpage); |
37d81828 | 5275 | |
11bac800 | 5276 | static int perf_mmap_fault(struct vm_fault *vmf) |
906010b2 | 5277 | { |
11bac800 | 5278 | struct perf_event *event = vmf->vma->vm_file->private_data; |
76369139 | 5279 | struct ring_buffer *rb; |
906010b2 PZ |
5280 | int ret = VM_FAULT_SIGBUS; |
5281 | ||
5282 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
5283 | if (vmf->pgoff == 0) | |
5284 | ret = 0; | |
5285 | return ret; | |
5286 | } | |
5287 | ||
5288 | rcu_read_lock(); | |
76369139 FW |
5289 | rb = rcu_dereference(event->rb); |
5290 | if (!rb) | |
906010b2 PZ |
5291 | goto unlock; |
5292 | ||
5293 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
5294 | goto unlock; | |
5295 | ||
76369139 | 5296 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
5297 | if (!vmf->page) |
5298 | goto unlock; | |
5299 | ||
5300 | get_page(vmf->page); | |
11bac800 | 5301 | vmf->page->mapping = vmf->vma->vm_file->f_mapping; |
906010b2 PZ |
5302 | vmf->page->index = vmf->pgoff; |
5303 | ||
5304 | ret = 0; | |
5305 | unlock: | |
5306 | rcu_read_unlock(); | |
5307 | ||
5308 | return ret; | |
5309 | } | |
5310 | ||
10c6db11 PZ |
5311 | static void ring_buffer_attach(struct perf_event *event, |
5312 | struct ring_buffer *rb) | |
5313 | { | |
b69cf536 | 5314 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
5315 | unsigned long flags; |
5316 | ||
b69cf536 PZ |
5317 | if (event->rb) { |
5318 | /* | |
5319 | * Should be impossible, we set this when removing | |
5320 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
5321 | */ | |
5322 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 5323 | |
b69cf536 | 5324 | old_rb = event->rb; |
b69cf536 PZ |
5325 | spin_lock_irqsave(&old_rb->event_lock, flags); |
5326 | list_del_rcu(&event->rb_entry); | |
5327 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 5328 | |
2f993cf0 ON |
5329 | event->rcu_batches = get_state_synchronize_rcu(); |
5330 | event->rcu_pending = 1; | |
b69cf536 | 5331 | } |
10c6db11 | 5332 | |
b69cf536 | 5333 | if (rb) { |
2f993cf0 ON |
5334 | if (event->rcu_pending) { |
5335 | cond_synchronize_rcu(event->rcu_batches); | |
5336 | event->rcu_pending = 0; | |
5337 | } | |
5338 | ||
b69cf536 PZ |
5339 | spin_lock_irqsave(&rb->event_lock, flags); |
5340 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
5341 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
5342 | } | |
5343 | ||
767ae086 AS |
5344 | /* |
5345 | * Avoid racing with perf_mmap_close(AUX): stop the event | |
5346 | * before swizzling the event::rb pointer; if it's getting | |
5347 | * unmapped, its aux_mmap_count will be 0 and it won't | |
5348 | * restart. See the comment in __perf_pmu_output_stop(). | |
5349 | * | |
5350 | * Data will inevitably be lost when set_output is done in | |
5351 | * mid-air, but then again, whoever does it like this is | |
5352 | * not in for the data anyway. | |
5353 | */ | |
5354 | if (has_aux(event)) | |
5355 | perf_event_stop(event, 0); | |
5356 | ||
b69cf536 PZ |
5357 | rcu_assign_pointer(event->rb, rb); |
5358 | ||
5359 | if (old_rb) { | |
5360 | ring_buffer_put(old_rb); | |
5361 | /* | |
5362 | * Since we detached before setting the new rb, so that we | |
5363 | * could attach the new rb, we could have missed a wakeup. | |
5364 | * Provide it now. | |
5365 | */ | |
5366 | wake_up_all(&event->waitq); | |
5367 | } | |
10c6db11 PZ |
5368 | } |
5369 | ||
5370 | static void ring_buffer_wakeup(struct perf_event *event) | |
5371 | { | |
5372 | struct ring_buffer *rb; | |
5373 | ||
5374 | rcu_read_lock(); | |
5375 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
5376 | if (rb) { |
5377 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
5378 | wake_up_all(&event->waitq); | |
5379 | } | |
10c6db11 PZ |
5380 | rcu_read_unlock(); |
5381 | } | |
5382 | ||
fdc26706 | 5383 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 5384 | { |
76369139 | 5385 | struct ring_buffer *rb; |
7b732a75 | 5386 | |
ac9721f3 | 5387 | rcu_read_lock(); |
76369139 FW |
5388 | rb = rcu_dereference(event->rb); |
5389 | if (rb) { | |
5390 | if (!atomic_inc_not_zero(&rb->refcount)) | |
5391 | rb = NULL; | |
ac9721f3 PZ |
5392 | } |
5393 | rcu_read_unlock(); | |
5394 | ||
76369139 | 5395 | return rb; |
ac9721f3 PZ |
5396 | } |
5397 | ||
fdc26706 | 5398 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 5399 | { |
76369139 | 5400 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 5401 | return; |
7b732a75 | 5402 | |
9bb5d40c | 5403 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 5404 | |
76369139 | 5405 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
5406 | } |
5407 | ||
5408 | static void perf_mmap_open(struct vm_area_struct *vma) | |
5409 | { | |
cdd6c482 | 5410 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 5411 | |
cdd6c482 | 5412 | atomic_inc(&event->mmap_count); |
9bb5d40c | 5413 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 5414 | |
45bfb2e5 PZ |
5415 | if (vma->vm_pgoff) |
5416 | atomic_inc(&event->rb->aux_mmap_count); | |
5417 | ||
1e0fb9ec | 5418 | if (event->pmu->event_mapped) |
bfe33492 | 5419 | event->pmu->event_mapped(event, vma->vm_mm); |
7b732a75 PZ |
5420 | } |
5421 | ||
95ff4ca2 AS |
5422 | static void perf_pmu_output_stop(struct perf_event *event); |
5423 | ||
9bb5d40c PZ |
5424 | /* |
5425 | * A buffer can be mmap()ed multiple times; either directly through the same | |
5426 | * event, or through other events by use of perf_event_set_output(). | |
5427 | * | |
5428 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
5429 | * the buffer here, where we still have a VM context. This means we need | |
5430 | * to detach all events redirecting to us. | |
5431 | */ | |
7b732a75 PZ |
5432 | static void perf_mmap_close(struct vm_area_struct *vma) |
5433 | { | |
cdd6c482 | 5434 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 5435 | |
b69cf536 | 5436 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
5437 | struct user_struct *mmap_user = rb->mmap_user; |
5438 | int mmap_locked = rb->mmap_locked; | |
5439 | unsigned long size = perf_data_size(rb); | |
789f90fc | 5440 | |
1e0fb9ec | 5441 | if (event->pmu->event_unmapped) |
bfe33492 | 5442 | event->pmu->event_unmapped(event, vma->vm_mm); |
1e0fb9ec | 5443 | |
45bfb2e5 PZ |
5444 | /* |
5445 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
5446 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
5447 | * serialize with perf_mmap here. | |
5448 | */ | |
5449 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
5450 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
95ff4ca2 AS |
5451 | /* |
5452 | * Stop all AUX events that are writing to this buffer, | |
5453 | * so that we can free its AUX pages and corresponding PMU | |
5454 | * data. Note that after rb::aux_mmap_count dropped to zero, | |
5455 | * they won't start any more (see perf_aux_output_begin()). | |
5456 | */ | |
5457 | perf_pmu_output_stop(event); | |
5458 | ||
5459 | /* now it's safe to free the pages */ | |
45bfb2e5 PZ |
5460 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); |
5461 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
5462 | ||
95ff4ca2 | 5463 | /* this has to be the last one */ |
45bfb2e5 | 5464 | rb_free_aux(rb); |
95ff4ca2 AS |
5465 | WARN_ON_ONCE(atomic_read(&rb->aux_refcount)); |
5466 | ||
45bfb2e5 PZ |
5467 | mutex_unlock(&event->mmap_mutex); |
5468 | } | |
5469 | ||
9bb5d40c PZ |
5470 | atomic_dec(&rb->mmap_count); |
5471 | ||
5472 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 5473 | goto out_put; |
9bb5d40c | 5474 | |
b69cf536 | 5475 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
5476 | mutex_unlock(&event->mmap_mutex); |
5477 | ||
5478 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
5479 | if (atomic_read(&rb->mmap_count)) |
5480 | goto out_put; | |
ac9721f3 | 5481 | |
9bb5d40c PZ |
5482 | /* |
5483 | * No other mmap()s, detach from all other events that might redirect | |
5484 | * into the now unreachable buffer. Somewhat complicated by the | |
5485 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
5486 | */ | |
5487 | again: | |
5488 | rcu_read_lock(); | |
5489 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
5490 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
5491 | /* | |
5492 | * This event is en-route to free_event() which will | |
5493 | * detach it and remove it from the list. | |
5494 | */ | |
5495 | continue; | |
5496 | } | |
5497 | rcu_read_unlock(); | |
789f90fc | 5498 | |
9bb5d40c PZ |
5499 | mutex_lock(&event->mmap_mutex); |
5500 | /* | |
5501 | * Check we didn't race with perf_event_set_output() which can | |
5502 | * swizzle the rb from under us while we were waiting to | |
5503 | * acquire mmap_mutex. | |
5504 | * | |
5505 | * If we find a different rb; ignore this event, a next | |
5506 | * iteration will no longer find it on the list. We have to | |
5507 | * still restart the iteration to make sure we're not now | |
5508 | * iterating the wrong list. | |
5509 | */ | |
b69cf536 PZ |
5510 | if (event->rb == rb) |
5511 | ring_buffer_attach(event, NULL); | |
5512 | ||
cdd6c482 | 5513 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 5514 | put_event(event); |
ac9721f3 | 5515 | |
9bb5d40c PZ |
5516 | /* |
5517 | * Restart the iteration; either we're on the wrong list or | |
5518 | * destroyed its integrity by doing a deletion. | |
5519 | */ | |
5520 | goto again; | |
7b732a75 | 5521 | } |
9bb5d40c PZ |
5522 | rcu_read_unlock(); |
5523 | ||
5524 | /* | |
5525 | * It could be there's still a few 0-ref events on the list; they'll | |
5526 | * get cleaned up by free_event() -- they'll also still have their | |
5527 | * ref on the rb and will free it whenever they are done with it. | |
5528 | * | |
5529 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
5530 | * undo the VM accounting. | |
5531 | */ | |
5532 | ||
5533 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
5534 | vma->vm_mm->pinned_vm -= mmap_locked; | |
5535 | free_uid(mmap_user); | |
5536 | ||
b69cf536 | 5537 | out_put: |
9bb5d40c | 5538 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
5539 | } |
5540 | ||
f0f37e2f | 5541 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 5542 | .open = perf_mmap_open, |
45bfb2e5 | 5543 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
5544 | .fault = perf_mmap_fault, |
5545 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
5546 | }; |
5547 | ||
5548 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
5549 | { | |
cdd6c482 | 5550 | struct perf_event *event = file->private_data; |
22a4f650 | 5551 | unsigned long user_locked, user_lock_limit; |
789f90fc | 5552 | struct user_struct *user = current_user(); |
22a4f650 | 5553 | unsigned long locked, lock_limit; |
45bfb2e5 | 5554 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
5555 | unsigned long vma_size; |
5556 | unsigned long nr_pages; | |
45bfb2e5 | 5557 | long user_extra = 0, extra = 0; |
d57e34fd | 5558 | int ret = 0, flags = 0; |
37d81828 | 5559 | |
c7920614 PZ |
5560 | /* |
5561 | * Don't allow mmap() of inherited per-task counters. This would | |
5562 | * create a performance issue due to all children writing to the | |
76369139 | 5563 | * same rb. |
c7920614 PZ |
5564 | */ |
5565 | if (event->cpu == -1 && event->attr.inherit) | |
5566 | return -EINVAL; | |
5567 | ||
43a21ea8 | 5568 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 5569 | return -EINVAL; |
7b732a75 PZ |
5570 | |
5571 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
5572 | |
5573 | if (vma->vm_pgoff == 0) { | |
5574 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
5575 | } else { | |
5576 | /* | |
5577 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
5578 | * mapped, all subsequent mappings should have the same size | |
5579 | * and offset. Must be above the normal perf buffer. | |
5580 | */ | |
5581 | u64 aux_offset, aux_size; | |
5582 | ||
5583 | if (!event->rb) | |
5584 | return -EINVAL; | |
5585 | ||
5586 | nr_pages = vma_size / PAGE_SIZE; | |
5587 | ||
5588 | mutex_lock(&event->mmap_mutex); | |
5589 | ret = -EINVAL; | |
5590 | ||
5591 | rb = event->rb; | |
5592 | if (!rb) | |
5593 | goto aux_unlock; | |
5594 | ||
6aa7de05 MR |
5595 | aux_offset = READ_ONCE(rb->user_page->aux_offset); |
5596 | aux_size = READ_ONCE(rb->user_page->aux_size); | |
45bfb2e5 PZ |
5597 | |
5598 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
5599 | goto aux_unlock; | |
5600 | ||
5601 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
5602 | goto aux_unlock; | |
5603 | ||
5604 | /* already mapped with a different offset */ | |
5605 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
5606 | goto aux_unlock; | |
5607 | ||
5608 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
5609 | goto aux_unlock; | |
5610 | ||
5611 | /* already mapped with a different size */ | |
5612 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
5613 | goto aux_unlock; | |
5614 | ||
5615 | if (!is_power_of_2(nr_pages)) | |
5616 | goto aux_unlock; | |
5617 | ||
5618 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
5619 | goto aux_unlock; | |
5620 | ||
5621 | if (rb_has_aux(rb)) { | |
5622 | atomic_inc(&rb->aux_mmap_count); | |
5623 | ret = 0; | |
5624 | goto unlock; | |
5625 | } | |
5626 | ||
5627 | atomic_set(&rb->aux_mmap_count, 1); | |
5628 | user_extra = nr_pages; | |
5629 | ||
5630 | goto accounting; | |
5631 | } | |
7b732a75 | 5632 | |
7730d865 | 5633 | /* |
76369139 | 5634 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
5635 | * can do bitmasks instead of modulo. |
5636 | */ | |
2ed11312 | 5637 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
5638 | return -EINVAL; |
5639 | ||
7b732a75 | 5640 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
5641 | return -EINVAL; |
5642 | ||
cdd6c482 | 5643 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 5644 | again: |
cdd6c482 | 5645 | mutex_lock(&event->mmap_mutex); |
76369139 | 5646 | if (event->rb) { |
9bb5d40c | 5647 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 5648 | ret = -EINVAL; |
9bb5d40c PZ |
5649 | goto unlock; |
5650 | } | |
5651 | ||
5652 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
5653 | /* | |
5654 | * Raced against perf_mmap_close() through | |
5655 | * perf_event_set_output(). Try again, hope for better | |
5656 | * luck. | |
5657 | */ | |
5658 | mutex_unlock(&event->mmap_mutex); | |
5659 | goto again; | |
5660 | } | |
5661 | ||
ebb3c4c4 PZ |
5662 | goto unlock; |
5663 | } | |
5664 | ||
789f90fc | 5665 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
5666 | |
5667 | accounting: | |
cdd6c482 | 5668 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
5669 | |
5670 | /* | |
5671 | * Increase the limit linearly with more CPUs: | |
5672 | */ | |
5673 | user_lock_limit *= num_online_cpus(); | |
5674 | ||
789f90fc | 5675 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 5676 | |
789f90fc PZ |
5677 | if (user_locked > user_lock_limit) |
5678 | extra = user_locked - user_lock_limit; | |
7b732a75 | 5679 | |
78d7d407 | 5680 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 5681 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 5682 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 5683 | |
459ec28a IM |
5684 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
5685 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
5686 | ret = -EPERM; |
5687 | goto unlock; | |
5688 | } | |
7b732a75 | 5689 | |
45bfb2e5 | 5690 | WARN_ON(!rb && event->rb); |
906010b2 | 5691 | |
d57e34fd | 5692 | if (vma->vm_flags & VM_WRITE) |
76369139 | 5693 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 5694 | |
76369139 | 5695 | if (!rb) { |
45bfb2e5 PZ |
5696 | rb = rb_alloc(nr_pages, |
5697 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
5698 | event->cpu, flags); | |
26cb63ad | 5699 | |
45bfb2e5 PZ |
5700 | if (!rb) { |
5701 | ret = -ENOMEM; | |
5702 | goto unlock; | |
5703 | } | |
43a21ea8 | 5704 | |
45bfb2e5 PZ |
5705 | atomic_set(&rb->mmap_count, 1); |
5706 | rb->mmap_user = get_current_user(); | |
5707 | rb->mmap_locked = extra; | |
26cb63ad | 5708 | |
45bfb2e5 | 5709 | ring_buffer_attach(event, rb); |
ac9721f3 | 5710 | |
45bfb2e5 PZ |
5711 | perf_event_init_userpage(event); |
5712 | perf_event_update_userpage(event); | |
5713 | } else { | |
1a594131 AS |
5714 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
5715 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
5716 | if (!ret) |
5717 | rb->aux_mmap_locked = extra; | |
5718 | } | |
9a0f05cb | 5719 | |
ebb3c4c4 | 5720 | unlock: |
45bfb2e5 PZ |
5721 | if (!ret) { |
5722 | atomic_long_add(user_extra, &user->locked_vm); | |
5723 | vma->vm_mm->pinned_vm += extra; | |
5724 | ||
ac9721f3 | 5725 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
5726 | } else if (rb) { |
5727 | atomic_dec(&rb->mmap_count); | |
5728 | } | |
5729 | aux_unlock: | |
cdd6c482 | 5730 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 5731 | |
9bb5d40c PZ |
5732 | /* |
5733 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
5734 | * vma. | |
5735 | */ | |
26cb63ad | 5736 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 5737 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 5738 | |
1e0fb9ec | 5739 | if (event->pmu->event_mapped) |
bfe33492 | 5740 | event->pmu->event_mapped(event, vma->vm_mm); |
1e0fb9ec | 5741 | |
7b732a75 | 5742 | return ret; |
37d81828 PM |
5743 | } |
5744 | ||
3c446b3d PZ |
5745 | static int perf_fasync(int fd, struct file *filp, int on) |
5746 | { | |
496ad9aa | 5747 | struct inode *inode = file_inode(filp); |
cdd6c482 | 5748 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
5749 | int retval; |
5750 | ||
5955102c | 5751 | inode_lock(inode); |
cdd6c482 | 5752 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 5753 | inode_unlock(inode); |
3c446b3d PZ |
5754 | |
5755 | if (retval < 0) | |
5756 | return retval; | |
5757 | ||
5758 | return 0; | |
5759 | } | |
5760 | ||
0793a61d | 5761 | static const struct file_operations perf_fops = { |
3326c1ce | 5762 | .llseek = no_llseek, |
0793a61d TG |
5763 | .release = perf_release, |
5764 | .read = perf_read, | |
5765 | .poll = perf_poll, | |
d859e29f | 5766 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 5767 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 5768 | .mmap = perf_mmap, |
3c446b3d | 5769 | .fasync = perf_fasync, |
0793a61d TG |
5770 | }; |
5771 | ||
925d519a | 5772 | /* |
cdd6c482 | 5773 | * Perf event wakeup |
925d519a PZ |
5774 | * |
5775 | * If there's data, ensure we set the poll() state and publish everything | |
5776 | * to user-space before waking everybody up. | |
5777 | */ | |
5778 | ||
fed66e2c PZ |
5779 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
5780 | { | |
5781 | /* only the parent has fasync state */ | |
5782 | if (event->parent) | |
5783 | event = event->parent; | |
5784 | return &event->fasync; | |
5785 | } | |
5786 | ||
cdd6c482 | 5787 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 5788 | { |
10c6db11 | 5789 | ring_buffer_wakeup(event); |
4c9e2542 | 5790 | |
cdd6c482 | 5791 | if (event->pending_kill) { |
fed66e2c | 5792 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 5793 | event->pending_kill = 0; |
4c9e2542 | 5794 | } |
925d519a PZ |
5795 | } |
5796 | ||
e360adbe | 5797 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 5798 | { |
cdd6c482 IM |
5799 | struct perf_event *event = container_of(entry, |
5800 | struct perf_event, pending); | |
d525211f PZ |
5801 | int rctx; |
5802 | ||
5803 | rctx = perf_swevent_get_recursion_context(); | |
5804 | /* | |
5805 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
5806 | * and we won't recurse 'further'. | |
5807 | */ | |
79f14641 | 5808 | |
cdd6c482 IM |
5809 | if (event->pending_disable) { |
5810 | event->pending_disable = 0; | |
fae3fde6 | 5811 | perf_event_disable_local(event); |
79f14641 PZ |
5812 | } |
5813 | ||
cdd6c482 IM |
5814 | if (event->pending_wakeup) { |
5815 | event->pending_wakeup = 0; | |
5816 | perf_event_wakeup(event); | |
79f14641 | 5817 | } |
d525211f PZ |
5818 | |
5819 | if (rctx >= 0) | |
5820 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
5821 | } |
5822 | ||
39447b38 ZY |
5823 | /* |
5824 | * We assume there is only KVM supporting the callbacks. | |
5825 | * Later on, we might change it to a list if there is | |
5826 | * another virtualization implementation supporting the callbacks. | |
5827 | */ | |
5828 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
5829 | ||
5830 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5831 | { | |
5832 | perf_guest_cbs = cbs; | |
5833 | return 0; | |
5834 | } | |
5835 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
5836 | ||
5837 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5838 | { | |
5839 | perf_guest_cbs = NULL; | |
5840 | return 0; | |
5841 | } | |
5842 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5843 | ||
4018994f JO |
5844 | static void |
5845 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5846 | struct pt_regs *regs, u64 mask) | |
5847 | { | |
5848 | int bit; | |
29dd3288 | 5849 | DECLARE_BITMAP(_mask, 64); |
4018994f | 5850 | |
29dd3288 MS |
5851 | bitmap_from_u64(_mask, mask); |
5852 | for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) { | |
4018994f JO |
5853 | u64 val; |
5854 | ||
5855 | val = perf_reg_value(regs, bit); | |
5856 | perf_output_put(handle, val); | |
5857 | } | |
5858 | } | |
5859 | ||
60e2364e | 5860 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5861 | struct pt_regs *regs, |
5862 | struct pt_regs *regs_user_copy) | |
4018994f | 5863 | { |
88a7c26a AL |
5864 | if (user_mode(regs)) { |
5865 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5866 | regs_user->regs = regs; |
88a7c26a AL |
5867 | } else if (current->mm) { |
5868 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5869 | } else { |
5870 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5871 | regs_user->regs = NULL; | |
4018994f JO |
5872 | } |
5873 | } | |
5874 | ||
60e2364e SE |
5875 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5876 | struct pt_regs *regs) | |
5877 | { | |
5878 | regs_intr->regs = regs; | |
5879 | regs_intr->abi = perf_reg_abi(current); | |
5880 | } | |
5881 | ||
5882 | ||
c5ebcedb JO |
5883 | /* |
5884 | * Get remaining task size from user stack pointer. | |
5885 | * | |
5886 | * It'd be better to take stack vma map and limit this more | |
5887 | * precisly, but there's no way to get it safely under interrupt, | |
5888 | * so using TASK_SIZE as limit. | |
5889 | */ | |
5890 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5891 | { | |
5892 | unsigned long addr = perf_user_stack_pointer(regs); | |
5893 | ||
5894 | if (!addr || addr >= TASK_SIZE) | |
5895 | return 0; | |
5896 | ||
5897 | return TASK_SIZE - addr; | |
5898 | } | |
5899 | ||
5900 | static u16 | |
5901 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5902 | struct pt_regs *regs) | |
5903 | { | |
5904 | u64 task_size; | |
5905 | ||
5906 | /* No regs, no stack pointer, no dump. */ | |
5907 | if (!regs) | |
5908 | return 0; | |
5909 | ||
5910 | /* | |
5911 | * Check if we fit in with the requested stack size into the: | |
5912 | * - TASK_SIZE | |
5913 | * If we don't, we limit the size to the TASK_SIZE. | |
5914 | * | |
5915 | * - remaining sample size | |
5916 | * If we don't, we customize the stack size to | |
5917 | * fit in to the remaining sample size. | |
5918 | */ | |
5919 | ||
5920 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5921 | stack_size = min(stack_size, (u16) task_size); | |
5922 | ||
5923 | /* Current header size plus static size and dynamic size. */ | |
5924 | header_size += 2 * sizeof(u64); | |
5925 | ||
5926 | /* Do we fit in with the current stack dump size? */ | |
5927 | if ((u16) (header_size + stack_size) < header_size) { | |
5928 | /* | |
5929 | * If we overflow the maximum size for the sample, | |
5930 | * we customize the stack dump size to fit in. | |
5931 | */ | |
5932 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5933 | stack_size = round_up(stack_size, sizeof(u64)); | |
5934 | } | |
5935 | ||
5936 | return stack_size; | |
5937 | } | |
5938 | ||
5939 | static void | |
5940 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5941 | struct pt_regs *regs) | |
5942 | { | |
5943 | /* Case of a kernel thread, nothing to dump */ | |
5944 | if (!regs) { | |
5945 | u64 size = 0; | |
5946 | perf_output_put(handle, size); | |
5947 | } else { | |
5948 | unsigned long sp; | |
5949 | unsigned int rem; | |
5950 | u64 dyn_size; | |
5951 | ||
5952 | /* | |
5953 | * We dump: | |
5954 | * static size | |
5955 | * - the size requested by user or the best one we can fit | |
5956 | * in to the sample max size | |
5957 | * data | |
5958 | * - user stack dump data | |
5959 | * dynamic size | |
5960 | * - the actual dumped size | |
5961 | */ | |
5962 | ||
5963 | /* Static size. */ | |
5964 | perf_output_put(handle, dump_size); | |
5965 | ||
5966 | /* Data. */ | |
5967 | sp = perf_user_stack_pointer(regs); | |
5968 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5969 | dyn_size = dump_size - rem; | |
5970 | ||
5971 | perf_output_skip(handle, rem); | |
5972 | ||
5973 | /* Dynamic size. */ | |
5974 | perf_output_put(handle, dyn_size); | |
5975 | } | |
5976 | } | |
5977 | ||
c980d109 ACM |
5978 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5979 | struct perf_sample_data *data, | |
5980 | struct perf_event *event) | |
6844c09d ACM |
5981 | { |
5982 | u64 sample_type = event->attr.sample_type; | |
5983 | ||
5984 | data->type = sample_type; | |
5985 | header->size += event->id_header_size; | |
5986 | ||
5987 | if (sample_type & PERF_SAMPLE_TID) { | |
5988 | /* namespace issues */ | |
5989 | data->tid_entry.pid = perf_event_pid(event, current); | |
5990 | data->tid_entry.tid = perf_event_tid(event, current); | |
5991 | } | |
5992 | ||
5993 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5994 | data->time = perf_event_clock(event); |
6844c09d | 5995 | |
ff3d527c | 5996 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5997 | data->id = primary_event_id(event); |
5998 | ||
5999 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
6000 | data->stream_id = event->id; | |
6001 | ||
6002 | if (sample_type & PERF_SAMPLE_CPU) { | |
6003 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
6004 | data->cpu_entry.reserved = 0; | |
6005 | } | |
6006 | } | |
6007 | ||
76369139 FW |
6008 | void perf_event_header__init_id(struct perf_event_header *header, |
6009 | struct perf_sample_data *data, | |
6010 | struct perf_event *event) | |
c980d109 ACM |
6011 | { |
6012 | if (event->attr.sample_id_all) | |
6013 | __perf_event_header__init_id(header, data, event); | |
6014 | } | |
6015 | ||
6016 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
6017 | struct perf_sample_data *data) | |
6018 | { | |
6019 | u64 sample_type = data->type; | |
6020 | ||
6021 | if (sample_type & PERF_SAMPLE_TID) | |
6022 | perf_output_put(handle, data->tid_entry); | |
6023 | ||
6024 | if (sample_type & PERF_SAMPLE_TIME) | |
6025 | perf_output_put(handle, data->time); | |
6026 | ||
6027 | if (sample_type & PERF_SAMPLE_ID) | |
6028 | perf_output_put(handle, data->id); | |
6029 | ||
6030 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
6031 | perf_output_put(handle, data->stream_id); | |
6032 | ||
6033 | if (sample_type & PERF_SAMPLE_CPU) | |
6034 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
6035 | |
6036 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
6037 | perf_output_put(handle, data->id); | |
c980d109 ACM |
6038 | } |
6039 | ||
76369139 FW |
6040 | void perf_event__output_id_sample(struct perf_event *event, |
6041 | struct perf_output_handle *handle, | |
6042 | struct perf_sample_data *sample) | |
c980d109 ACM |
6043 | { |
6044 | if (event->attr.sample_id_all) | |
6045 | __perf_event__output_id_sample(handle, sample); | |
6046 | } | |
6047 | ||
3dab77fb | 6048 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
6049 | struct perf_event *event, |
6050 | u64 enabled, u64 running) | |
3dab77fb | 6051 | { |
cdd6c482 | 6052 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
6053 | u64 values[4]; |
6054 | int n = 0; | |
6055 | ||
b5e58793 | 6056 | values[n++] = perf_event_count(event); |
3dab77fb | 6057 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 6058 | values[n++] = enabled + |
cdd6c482 | 6059 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
6060 | } |
6061 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 6062 | values[n++] = running + |
cdd6c482 | 6063 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
6064 | } |
6065 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 6066 | values[n++] = primary_event_id(event); |
3dab77fb | 6067 | |
76369139 | 6068 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
6069 | } |
6070 | ||
3dab77fb | 6071 | static void perf_output_read_group(struct perf_output_handle *handle, |
eed01528 SE |
6072 | struct perf_event *event, |
6073 | u64 enabled, u64 running) | |
3dab77fb | 6074 | { |
cdd6c482 IM |
6075 | struct perf_event *leader = event->group_leader, *sub; |
6076 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
6077 | u64 values[5]; |
6078 | int n = 0; | |
6079 | ||
6080 | values[n++] = 1 + leader->nr_siblings; | |
6081 | ||
6082 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 6083 | values[n++] = enabled; |
3dab77fb PZ |
6084 | |
6085 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 6086 | values[n++] = running; |
3dab77fb | 6087 | |
9e5b127d PZ |
6088 | if ((leader != event) && |
6089 | (leader->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
6090 | leader->pmu->read(leader); |
6091 | ||
b5e58793 | 6092 | values[n++] = perf_event_count(leader); |
3dab77fb | 6093 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 6094 | values[n++] = primary_event_id(leader); |
3dab77fb | 6095 | |
76369139 | 6096 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 6097 | |
edb39592 | 6098 | for_each_sibling_event(sub, leader) { |
3dab77fb PZ |
6099 | n = 0; |
6100 | ||
6f5ab001 JO |
6101 | if ((sub != event) && |
6102 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
6103 | sub->pmu->read(sub); |
6104 | ||
b5e58793 | 6105 | values[n++] = perf_event_count(sub); |
3dab77fb | 6106 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 6107 | values[n++] = primary_event_id(sub); |
3dab77fb | 6108 | |
76369139 | 6109 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
6110 | } |
6111 | } | |
6112 | ||
eed01528 SE |
6113 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
6114 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
6115 | ||
ba5213ae PZ |
6116 | /* |
6117 | * XXX PERF_SAMPLE_READ vs inherited events seems difficult. | |
6118 | * | |
6119 | * The problem is that its both hard and excessively expensive to iterate the | |
6120 | * child list, not to mention that its impossible to IPI the children running | |
6121 | * on another CPU, from interrupt/NMI context. | |
6122 | */ | |
3dab77fb | 6123 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 6124 | struct perf_event *event) |
3dab77fb | 6125 | { |
e3f3541c | 6126 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
6127 | u64 read_format = event->attr.read_format; |
6128 | ||
6129 | /* | |
6130 | * compute total_time_enabled, total_time_running | |
6131 | * based on snapshot values taken when the event | |
6132 | * was last scheduled in. | |
6133 | * | |
6134 | * we cannot simply called update_context_time() | |
6135 | * because of locking issue as we are called in | |
6136 | * NMI context | |
6137 | */ | |
c4794295 | 6138 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 6139 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 6140 | |
cdd6c482 | 6141 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 6142 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 6143 | else |
eed01528 | 6144 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
6145 | } |
6146 | ||
5622f295 MM |
6147 | void perf_output_sample(struct perf_output_handle *handle, |
6148 | struct perf_event_header *header, | |
6149 | struct perf_sample_data *data, | |
cdd6c482 | 6150 | struct perf_event *event) |
5622f295 MM |
6151 | { |
6152 | u64 sample_type = data->type; | |
6153 | ||
6154 | perf_output_put(handle, *header); | |
6155 | ||
ff3d527c AH |
6156 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
6157 | perf_output_put(handle, data->id); | |
6158 | ||
5622f295 MM |
6159 | if (sample_type & PERF_SAMPLE_IP) |
6160 | perf_output_put(handle, data->ip); | |
6161 | ||
6162 | if (sample_type & PERF_SAMPLE_TID) | |
6163 | perf_output_put(handle, data->tid_entry); | |
6164 | ||
6165 | if (sample_type & PERF_SAMPLE_TIME) | |
6166 | perf_output_put(handle, data->time); | |
6167 | ||
6168 | if (sample_type & PERF_SAMPLE_ADDR) | |
6169 | perf_output_put(handle, data->addr); | |
6170 | ||
6171 | if (sample_type & PERF_SAMPLE_ID) | |
6172 | perf_output_put(handle, data->id); | |
6173 | ||
6174 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
6175 | perf_output_put(handle, data->stream_id); | |
6176 | ||
6177 | if (sample_type & PERF_SAMPLE_CPU) | |
6178 | perf_output_put(handle, data->cpu_entry); | |
6179 | ||
6180 | if (sample_type & PERF_SAMPLE_PERIOD) | |
6181 | perf_output_put(handle, data->period); | |
6182 | ||
6183 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 6184 | perf_output_read(handle, event); |
5622f295 MM |
6185 | |
6186 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
99e818cc | 6187 | int size = 1; |
5622f295 | 6188 | |
99e818cc JO |
6189 | size += data->callchain->nr; |
6190 | size *= sizeof(u64); | |
6191 | __output_copy(handle, data->callchain, size); | |
5622f295 MM |
6192 | } |
6193 | ||
6194 | if (sample_type & PERF_SAMPLE_RAW) { | |
7e3f977e DB |
6195 | struct perf_raw_record *raw = data->raw; |
6196 | ||
6197 | if (raw) { | |
6198 | struct perf_raw_frag *frag = &raw->frag; | |
6199 | ||
6200 | perf_output_put(handle, raw->size); | |
6201 | do { | |
6202 | if (frag->copy) { | |
6203 | __output_custom(handle, frag->copy, | |
6204 | frag->data, frag->size); | |
6205 | } else { | |
6206 | __output_copy(handle, frag->data, | |
6207 | frag->size); | |
6208 | } | |
6209 | if (perf_raw_frag_last(frag)) | |
6210 | break; | |
6211 | frag = frag->next; | |
6212 | } while (1); | |
6213 | if (frag->pad) | |
6214 | __output_skip(handle, NULL, frag->pad); | |
5622f295 MM |
6215 | } else { |
6216 | struct { | |
6217 | u32 size; | |
6218 | u32 data; | |
6219 | } raw = { | |
6220 | .size = sizeof(u32), | |
6221 | .data = 0, | |
6222 | }; | |
6223 | perf_output_put(handle, raw); | |
6224 | } | |
6225 | } | |
a7ac67ea | 6226 | |
bce38cd5 SE |
6227 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
6228 | if (data->br_stack) { | |
6229 | size_t size; | |
6230 | ||
6231 | size = data->br_stack->nr | |
6232 | * sizeof(struct perf_branch_entry); | |
6233 | ||
6234 | perf_output_put(handle, data->br_stack->nr); | |
6235 | perf_output_copy(handle, data->br_stack->entries, size); | |
6236 | } else { | |
6237 | /* | |
6238 | * we always store at least the value of nr | |
6239 | */ | |
6240 | u64 nr = 0; | |
6241 | perf_output_put(handle, nr); | |
6242 | } | |
6243 | } | |
4018994f JO |
6244 | |
6245 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
6246 | u64 abi = data->regs_user.abi; | |
6247 | ||
6248 | /* | |
6249 | * If there are no regs to dump, notice it through | |
6250 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
6251 | */ | |
6252 | perf_output_put(handle, abi); | |
6253 | ||
6254 | if (abi) { | |
6255 | u64 mask = event->attr.sample_regs_user; | |
6256 | perf_output_sample_regs(handle, | |
6257 | data->regs_user.regs, | |
6258 | mask); | |
6259 | } | |
6260 | } | |
c5ebcedb | 6261 | |
a5cdd40c | 6262 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
6263 | perf_output_sample_ustack(handle, |
6264 | data->stack_user_size, | |
6265 | data->regs_user.regs); | |
a5cdd40c | 6266 | } |
c3feedf2 AK |
6267 | |
6268 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
6269 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
6270 | |
6271 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
6272 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 6273 | |
fdfbbd07 AK |
6274 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
6275 | perf_output_put(handle, data->txn); | |
6276 | ||
60e2364e SE |
6277 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
6278 | u64 abi = data->regs_intr.abi; | |
6279 | /* | |
6280 | * If there are no regs to dump, notice it through | |
6281 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
6282 | */ | |
6283 | perf_output_put(handle, abi); | |
6284 | ||
6285 | if (abi) { | |
6286 | u64 mask = event->attr.sample_regs_intr; | |
6287 | ||
6288 | perf_output_sample_regs(handle, | |
6289 | data->regs_intr.regs, | |
6290 | mask); | |
6291 | } | |
6292 | } | |
6293 | ||
fc7ce9c7 KL |
6294 | if (sample_type & PERF_SAMPLE_PHYS_ADDR) |
6295 | perf_output_put(handle, data->phys_addr); | |
6296 | ||
a5cdd40c PZ |
6297 | if (!event->attr.watermark) { |
6298 | int wakeup_events = event->attr.wakeup_events; | |
6299 | ||
6300 | if (wakeup_events) { | |
6301 | struct ring_buffer *rb = handle->rb; | |
6302 | int events = local_inc_return(&rb->events); | |
6303 | ||
6304 | if (events >= wakeup_events) { | |
6305 | local_sub(wakeup_events, &rb->events); | |
6306 | local_inc(&rb->wakeup); | |
6307 | } | |
6308 | } | |
6309 | } | |
5622f295 MM |
6310 | } |
6311 | ||
fc7ce9c7 KL |
6312 | static u64 perf_virt_to_phys(u64 virt) |
6313 | { | |
6314 | u64 phys_addr = 0; | |
6315 | struct page *p = NULL; | |
6316 | ||
6317 | if (!virt) | |
6318 | return 0; | |
6319 | ||
6320 | if (virt >= TASK_SIZE) { | |
6321 | /* If it's vmalloc()d memory, leave phys_addr as 0 */ | |
6322 | if (virt_addr_valid((void *)(uintptr_t)virt) && | |
6323 | !(virt >= VMALLOC_START && virt < VMALLOC_END)) | |
6324 | phys_addr = (u64)virt_to_phys((void *)(uintptr_t)virt); | |
6325 | } else { | |
6326 | /* | |
6327 | * Walking the pages tables for user address. | |
6328 | * Interrupts are disabled, so it prevents any tear down | |
6329 | * of the page tables. | |
6330 | * Try IRQ-safe __get_user_pages_fast first. | |
6331 | * If failed, leave phys_addr as 0. | |
6332 | */ | |
6333 | if ((current->mm != NULL) && | |
6334 | (__get_user_pages_fast(virt, 1, 0, &p) == 1)) | |
6335 | phys_addr = page_to_phys(p) + virt % PAGE_SIZE; | |
6336 | ||
6337 | if (p) | |
6338 | put_page(p); | |
6339 | } | |
6340 | ||
6341 | return phys_addr; | |
6342 | } | |
6343 | ||
99e818cc JO |
6344 | static struct perf_callchain_entry __empty_callchain = { .nr = 0, }; |
6345 | ||
8cf7e0e2 JO |
6346 | static struct perf_callchain_entry * |
6347 | perf_callchain(struct perf_event *event, struct pt_regs *regs) | |
6348 | { | |
6349 | bool kernel = !event->attr.exclude_callchain_kernel; | |
6350 | bool user = !event->attr.exclude_callchain_user; | |
6351 | /* Disallow cross-task user callchains. */ | |
6352 | bool crosstask = event->ctx->task && event->ctx->task != current; | |
6353 | const u32 max_stack = event->attr.sample_max_stack; | |
99e818cc | 6354 | struct perf_callchain_entry *callchain; |
8cf7e0e2 JO |
6355 | |
6356 | if (!kernel && !user) | |
99e818cc | 6357 | return &__empty_callchain; |
8cf7e0e2 | 6358 | |
99e818cc JO |
6359 | callchain = get_perf_callchain(regs, 0, kernel, user, |
6360 | max_stack, crosstask, true); | |
6361 | return callchain ?: &__empty_callchain; | |
8cf7e0e2 JO |
6362 | } |
6363 | ||
5622f295 MM |
6364 | void perf_prepare_sample(struct perf_event_header *header, |
6365 | struct perf_sample_data *data, | |
cdd6c482 | 6366 | struct perf_event *event, |
5622f295 | 6367 | struct pt_regs *regs) |
7b732a75 | 6368 | { |
cdd6c482 | 6369 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 6370 | |
cdd6c482 | 6371 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 6372 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
6373 | |
6374 | header->misc = 0; | |
6375 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 6376 | |
c980d109 | 6377 | __perf_event_header__init_id(header, data, event); |
6844c09d | 6378 | |
c320c7b7 | 6379 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
6380 | data->ip = perf_instruction_pointer(regs); |
6381 | ||
b23f3325 | 6382 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 6383 | int size = 1; |
394ee076 | 6384 | |
e6dab5ff | 6385 | data->callchain = perf_callchain(event, regs); |
99e818cc | 6386 | size += data->callchain->nr; |
5622f295 MM |
6387 | |
6388 | header->size += size * sizeof(u64); | |
394ee076 PZ |
6389 | } |
6390 | ||
3a43ce68 | 6391 | if (sample_type & PERF_SAMPLE_RAW) { |
7e3f977e DB |
6392 | struct perf_raw_record *raw = data->raw; |
6393 | int size; | |
6394 | ||
6395 | if (raw) { | |
6396 | struct perf_raw_frag *frag = &raw->frag; | |
6397 | u32 sum = 0; | |
6398 | ||
6399 | do { | |
6400 | sum += frag->size; | |
6401 | if (perf_raw_frag_last(frag)) | |
6402 | break; | |
6403 | frag = frag->next; | |
6404 | } while (1); | |
6405 | ||
6406 | size = round_up(sum + sizeof(u32), sizeof(u64)); | |
6407 | raw->size = size - sizeof(u32); | |
6408 | frag->pad = raw->size - sum; | |
6409 | } else { | |
6410 | size = sizeof(u64); | |
6411 | } | |
a044560c | 6412 | |
7e3f977e | 6413 | header->size += size; |
7f453c24 | 6414 | } |
bce38cd5 SE |
6415 | |
6416 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
6417 | int size = sizeof(u64); /* nr */ | |
6418 | if (data->br_stack) { | |
6419 | size += data->br_stack->nr | |
6420 | * sizeof(struct perf_branch_entry); | |
6421 | } | |
6422 | header->size += size; | |
6423 | } | |
4018994f | 6424 | |
2565711f | 6425 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
6426 | perf_sample_regs_user(&data->regs_user, regs, |
6427 | &data->regs_user_copy); | |
2565711f | 6428 | |
4018994f JO |
6429 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
6430 | /* regs dump ABI info */ | |
6431 | int size = sizeof(u64); | |
6432 | ||
4018994f JO |
6433 | if (data->regs_user.regs) { |
6434 | u64 mask = event->attr.sample_regs_user; | |
6435 | size += hweight64(mask) * sizeof(u64); | |
6436 | } | |
6437 | ||
6438 | header->size += size; | |
6439 | } | |
c5ebcedb JO |
6440 | |
6441 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
6442 | /* | |
6443 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
6444 | * processed as the last one or have additional check added | |
6445 | * in case new sample type is added, because we could eat | |
6446 | * up the rest of the sample size. | |
6447 | */ | |
c5ebcedb JO |
6448 | u16 stack_size = event->attr.sample_stack_user; |
6449 | u16 size = sizeof(u64); | |
6450 | ||
c5ebcedb | 6451 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 6452 | data->regs_user.regs); |
c5ebcedb JO |
6453 | |
6454 | /* | |
6455 | * If there is something to dump, add space for the dump | |
6456 | * itself and for the field that tells the dynamic size, | |
6457 | * which is how many have been actually dumped. | |
6458 | */ | |
6459 | if (stack_size) | |
6460 | size += sizeof(u64) + stack_size; | |
6461 | ||
6462 | data->stack_user_size = stack_size; | |
6463 | header->size += size; | |
6464 | } | |
60e2364e SE |
6465 | |
6466 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
6467 | /* regs dump ABI info */ | |
6468 | int size = sizeof(u64); | |
6469 | ||
6470 | perf_sample_regs_intr(&data->regs_intr, regs); | |
6471 | ||
6472 | if (data->regs_intr.regs) { | |
6473 | u64 mask = event->attr.sample_regs_intr; | |
6474 | ||
6475 | size += hweight64(mask) * sizeof(u64); | |
6476 | } | |
6477 | ||
6478 | header->size += size; | |
6479 | } | |
fc7ce9c7 KL |
6480 | |
6481 | if (sample_type & PERF_SAMPLE_PHYS_ADDR) | |
6482 | data->phys_addr = perf_virt_to_phys(data->addr); | |
5622f295 | 6483 | } |
7f453c24 | 6484 | |
9ecda41a WN |
6485 | static void __always_inline |
6486 | __perf_event_output(struct perf_event *event, | |
6487 | struct perf_sample_data *data, | |
6488 | struct pt_regs *regs, | |
6489 | int (*output_begin)(struct perf_output_handle *, | |
6490 | struct perf_event *, | |
6491 | unsigned int)) | |
5622f295 MM |
6492 | { |
6493 | struct perf_output_handle handle; | |
6494 | struct perf_event_header header; | |
689802b2 | 6495 | |
927c7a9e FW |
6496 | /* protect the callchain buffers */ |
6497 | rcu_read_lock(); | |
6498 | ||
cdd6c482 | 6499 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 6500 | |
9ecda41a | 6501 | if (output_begin(&handle, event, header.size)) |
927c7a9e | 6502 | goto exit; |
0322cd6e | 6503 | |
cdd6c482 | 6504 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 6505 | |
8a057d84 | 6506 | perf_output_end(&handle); |
927c7a9e FW |
6507 | |
6508 | exit: | |
6509 | rcu_read_unlock(); | |
0322cd6e PZ |
6510 | } |
6511 | ||
9ecda41a WN |
6512 | void |
6513 | perf_event_output_forward(struct perf_event *event, | |
6514 | struct perf_sample_data *data, | |
6515 | struct pt_regs *regs) | |
6516 | { | |
6517 | __perf_event_output(event, data, regs, perf_output_begin_forward); | |
6518 | } | |
6519 | ||
6520 | void | |
6521 | perf_event_output_backward(struct perf_event *event, | |
6522 | struct perf_sample_data *data, | |
6523 | struct pt_regs *regs) | |
6524 | { | |
6525 | __perf_event_output(event, data, regs, perf_output_begin_backward); | |
6526 | } | |
6527 | ||
6528 | void | |
6529 | perf_event_output(struct perf_event *event, | |
6530 | struct perf_sample_data *data, | |
6531 | struct pt_regs *regs) | |
6532 | { | |
6533 | __perf_event_output(event, data, regs, perf_output_begin); | |
6534 | } | |
6535 | ||
38b200d6 | 6536 | /* |
cdd6c482 | 6537 | * read event_id |
38b200d6 PZ |
6538 | */ |
6539 | ||
6540 | struct perf_read_event { | |
6541 | struct perf_event_header header; | |
6542 | ||
6543 | u32 pid; | |
6544 | u32 tid; | |
38b200d6 PZ |
6545 | }; |
6546 | ||
6547 | static void | |
cdd6c482 | 6548 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
6549 | struct task_struct *task) |
6550 | { | |
6551 | struct perf_output_handle handle; | |
c980d109 | 6552 | struct perf_sample_data sample; |
dfc65094 | 6553 | struct perf_read_event read_event = { |
38b200d6 | 6554 | .header = { |
cdd6c482 | 6555 | .type = PERF_RECORD_READ, |
38b200d6 | 6556 | .misc = 0, |
c320c7b7 | 6557 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 6558 | }, |
cdd6c482 IM |
6559 | .pid = perf_event_pid(event, task), |
6560 | .tid = perf_event_tid(event, task), | |
38b200d6 | 6561 | }; |
3dab77fb | 6562 | int ret; |
38b200d6 | 6563 | |
c980d109 | 6564 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 6565 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
6566 | if (ret) |
6567 | return; | |
6568 | ||
dfc65094 | 6569 | perf_output_put(&handle, read_event); |
cdd6c482 | 6570 | perf_output_read(&handle, event); |
c980d109 | 6571 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 6572 | |
38b200d6 PZ |
6573 | perf_output_end(&handle); |
6574 | } | |
6575 | ||
aab5b71e | 6576 | typedef void (perf_iterate_f)(struct perf_event *event, void *data); |
52d857a8 JO |
6577 | |
6578 | static void | |
aab5b71e PZ |
6579 | perf_iterate_ctx(struct perf_event_context *ctx, |
6580 | perf_iterate_f output, | |
b73e4fef | 6581 | void *data, bool all) |
52d857a8 JO |
6582 | { |
6583 | struct perf_event *event; | |
6584 | ||
6585 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
b73e4fef AS |
6586 | if (!all) { |
6587 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
6588 | continue; | |
6589 | if (!event_filter_match(event)) | |
6590 | continue; | |
6591 | } | |
6592 | ||
67516844 | 6593 | output(event, data); |
52d857a8 JO |
6594 | } |
6595 | } | |
6596 | ||
aab5b71e | 6597 | static void perf_iterate_sb_cpu(perf_iterate_f output, void *data) |
f2fb6bef KL |
6598 | { |
6599 | struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events); | |
6600 | struct perf_event *event; | |
6601 | ||
6602 | list_for_each_entry_rcu(event, &pel->list, sb_list) { | |
0b8f1e2e PZ |
6603 | /* |
6604 | * Skip events that are not fully formed yet; ensure that | |
6605 | * if we observe event->ctx, both event and ctx will be | |
6606 | * complete enough. See perf_install_in_context(). | |
6607 | */ | |
6608 | if (!smp_load_acquire(&event->ctx)) | |
6609 | continue; | |
6610 | ||
f2fb6bef KL |
6611 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
6612 | continue; | |
6613 | if (!event_filter_match(event)) | |
6614 | continue; | |
6615 | output(event, data); | |
6616 | } | |
6617 | } | |
6618 | ||
aab5b71e PZ |
6619 | /* |
6620 | * Iterate all events that need to receive side-band events. | |
6621 | * | |
6622 | * For new callers; ensure that account_pmu_sb_event() includes | |
6623 | * your event, otherwise it might not get delivered. | |
6624 | */ | |
52d857a8 | 6625 | static void |
aab5b71e | 6626 | perf_iterate_sb(perf_iterate_f output, void *data, |
52d857a8 JO |
6627 | struct perf_event_context *task_ctx) |
6628 | { | |
52d857a8 | 6629 | struct perf_event_context *ctx; |
52d857a8 JO |
6630 | int ctxn; |
6631 | ||
aab5b71e PZ |
6632 | rcu_read_lock(); |
6633 | preempt_disable(); | |
6634 | ||
4e93ad60 | 6635 | /* |
aab5b71e PZ |
6636 | * If we have task_ctx != NULL we only notify the task context itself. |
6637 | * The task_ctx is set only for EXIT events before releasing task | |
4e93ad60 JO |
6638 | * context. |
6639 | */ | |
6640 | if (task_ctx) { | |
aab5b71e PZ |
6641 | perf_iterate_ctx(task_ctx, output, data, false); |
6642 | goto done; | |
4e93ad60 JO |
6643 | } |
6644 | ||
aab5b71e | 6645 | perf_iterate_sb_cpu(output, data); |
f2fb6bef KL |
6646 | |
6647 | for_each_task_context_nr(ctxn) { | |
52d857a8 JO |
6648 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); |
6649 | if (ctx) | |
aab5b71e | 6650 | perf_iterate_ctx(ctx, output, data, false); |
52d857a8 | 6651 | } |
aab5b71e | 6652 | done: |
f2fb6bef | 6653 | preempt_enable(); |
52d857a8 | 6654 | rcu_read_unlock(); |
95ff4ca2 AS |
6655 | } |
6656 | ||
375637bc AS |
6657 | /* |
6658 | * Clear all file-based filters at exec, they'll have to be | |
6659 | * re-instated when/if these objects are mmapped again. | |
6660 | */ | |
6661 | static void perf_event_addr_filters_exec(struct perf_event *event, void *data) | |
6662 | { | |
6663 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
6664 | struct perf_addr_filter *filter; | |
6665 | unsigned int restart = 0, count = 0; | |
6666 | unsigned long flags; | |
6667 | ||
6668 | if (!has_addr_filter(event)) | |
6669 | return; | |
6670 | ||
6671 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
6672 | list_for_each_entry(filter, &ifh->list, entry) { | |
9511bce9 | 6673 | if (filter->path.dentry) { |
375637bc AS |
6674 | event->addr_filters_offs[count] = 0; |
6675 | restart++; | |
6676 | } | |
6677 | ||
6678 | count++; | |
6679 | } | |
6680 | ||
6681 | if (restart) | |
6682 | event->addr_filters_gen++; | |
6683 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
6684 | ||
6685 | if (restart) | |
767ae086 | 6686 | perf_event_stop(event, 1); |
375637bc AS |
6687 | } |
6688 | ||
6689 | void perf_event_exec(void) | |
6690 | { | |
6691 | struct perf_event_context *ctx; | |
6692 | int ctxn; | |
6693 | ||
6694 | rcu_read_lock(); | |
6695 | for_each_task_context_nr(ctxn) { | |
6696 | ctx = current->perf_event_ctxp[ctxn]; | |
6697 | if (!ctx) | |
6698 | continue; | |
6699 | ||
6700 | perf_event_enable_on_exec(ctxn); | |
6701 | ||
aab5b71e | 6702 | perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, |
375637bc AS |
6703 | true); |
6704 | } | |
6705 | rcu_read_unlock(); | |
6706 | } | |
6707 | ||
95ff4ca2 AS |
6708 | struct remote_output { |
6709 | struct ring_buffer *rb; | |
6710 | int err; | |
6711 | }; | |
6712 | ||
6713 | static void __perf_event_output_stop(struct perf_event *event, void *data) | |
6714 | { | |
6715 | struct perf_event *parent = event->parent; | |
6716 | struct remote_output *ro = data; | |
6717 | struct ring_buffer *rb = ro->rb; | |
375637bc AS |
6718 | struct stop_event_data sd = { |
6719 | .event = event, | |
6720 | }; | |
95ff4ca2 AS |
6721 | |
6722 | if (!has_aux(event)) | |
6723 | return; | |
6724 | ||
6725 | if (!parent) | |
6726 | parent = event; | |
6727 | ||
6728 | /* | |
6729 | * In case of inheritance, it will be the parent that links to the | |
767ae086 AS |
6730 | * ring-buffer, but it will be the child that's actually using it. |
6731 | * | |
6732 | * We are using event::rb to determine if the event should be stopped, | |
6733 | * however this may race with ring_buffer_attach() (through set_output), | |
6734 | * which will make us skip the event that actually needs to be stopped. | |
6735 | * So ring_buffer_attach() has to stop an aux event before re-assigning | |
6736 | * its rb pointer. | |
95ff4ca2 AS |
6737 | */ |
6738 | if (rcu_dereference(parent->rb) == rb) | |
375637bc | 6739 | ro->err = __perf_event_stop(&sd); |
95ff4ca2 AS |
6740 | } |
6741 | ||
6742 | static int __perf_pmu_output_stop(void *info) | |
6743 | { | |
6744 | struct perf_event *event = info; | |
6745 | struct pmu *pmu = event->pmu; | |
8b6a3fe8 | 6746 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95ff4ca2 AS |
6747 | struct remote_output ro = { |
6748 | .rb = event->rb, | |
6749 | }; | |
6750 | ||
6751 | rcu_read_lock(); | |
aab5b71e | 6752 | perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false); |
95ff4ca2 | 6753 | if (cpuctx->task_ctx) |
aab5b71e | 6754 | perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop, |
b73e4fef | 6755 | &ro, false); |
95ff4ca2 AS |
6756 | rcu_read_unlock(); |
6757 | ||
6758 | return ro.err; | |
6759 | } | |
6760 | ||
6761 | static void perf_pmu_output_stop(struct perf_event *event) | |
6762 | { | |
6763 | struct perf_event *iter; | |
6764 | int err, cpu; | |
6765 | ||
6766 | restart: | |
6767 | rcu_read_lock(); | |
6768 | list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { | |
6769 | /* | |
6770 | * For per-CPU events, we need to make sure that neither they | |
6771 | * nor their children are running; for cpu==-1 events it's | |
6772 | * sufficient to stop the event itself if it's active, since | |
6773 | * it can't have children. | |
6774 | */ | |
6775 | cpu = iter->cpu; | |
6776 | if (cpu == -1) | |
6777 | cpu = READ_ONCE(iter->oncpu); | |
6778 | ||
6779 | if (cpu == -1) | |
6780 | continue; | |
6781 | ||
6782 | err = cpu_function_call(cpu, __perf_pmu_output_stop, event); | |
6783 | if (err == -EAGAIN) { | |
6784 | rcu_read_unlock(); | |
6785 | goto restart; | |
6786 | } | |
6787 | } | |
6788 | rcu_read_unlock(); | |
52d857a8 JO |
6789 | } |
6790 | ||
60313ebe | 6791 | /* |
9f498cc5 PZ |
6792 | * task tracking -- fork/exit |
6793 | * | |
13d7a241 | 6794 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
6795 | */ |
6796 | ||
9f498cc5 | 6797 | struct perf_task_event { |
3a80b4a3 | 6798 | struct task_struct *task; |
cdd6c482 | 6799 | struct perf_event_context *task_ctx; |
60313ebe PZ |
6800 | |
6801 | struct { | |
6802 | struct perf_event_header header; | |
6803 | ||
6804 | u32 pid; | |
6805 | u32 ppid; | |
9f498cc5 PZ |
6806 | u32 tid; |
6807 | u32 ptid; | |
393b2ad8 | 6808 | u64 time; |
cdd6c482 | 6809 | } event_id; |
60313ebe PZ |
6810 | }; |
6811 | ||
67516844 JO |
6812 | static int perf_event_task_match(struct perf_event *event) |
6813 | { | |
13d7a241 SE |
6814 | return event->attr.comm || event->attr.mmap || |
6815 | event->attr.mmap2 || event->attr.mmap_data || | |
6816 | event->attr.task; | |
67516844 JO |
6817 | } |
6818 | ||
cdd6c482 | 6819 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 6820 | void *data) |
60313ebe | 6821 | { |
52d857a8 | 6822 | struct perf_task_event *task_event = data; |
60313ebe | 6823 | struct perf_output_handle handle; |
c980d109 | 6824 | struct perf_sample_data sample; |
9f498cc5 | 6825 | struct task_struct *task = task_event->task; |
c980d109 | 6826 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 6827 | |
67516844 JO |
6828 | if (!perf_event_task_match(event)) |
6829 | return; | |
6830 | ||
c980d109 | 6831 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 6832 | |
c980d109 | 6833 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 6834 | task_event->event_id.header.size); |
ef60777c | 6835 | if (ret) |
c980d109 | 6836 | goto out; |
60313ebe | 6837 | |
cdd6c482 IM |
6838 | task_event->event_id.pid = perf_event_pid(event, task); |
6839 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 6840 | |
cdd6c482 IM |
6841 | task_event->event_id.tid = perf_event_tid(event, task); |
6842 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 6843 | |
34f43927 PZ |
6844 | task_event->event_id.time = perf_event_clock(event); |
6845 | ||
cdd6c482 | 6846 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 6847 | |
c980d109 ACM |
6848 | perf_event__output_id_sample(event, &handle, &sample); |
6849 | ||
60313ebe | 6850 | perf_output_end(&handle); |
c980d109 ACM |
6851 | out: |
6852 | task_event->event_id.header.size = size; | |
60313ebe PZ |
6853 | } |
6854 | ||
cdd6c482 IM |
6855 | static void perf_event_task(struct task_struct *task, |
6856 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 6857 | int new) |
60313ebe | 6858 | { |
9f498cc5 | 6859 | struct perf_task_event task_event; |
60313ebe | 6860 | |
cdd6c482 IM |
6861 | if (!atomic_read(&nr_comm_events) && |
6862 | !atomic_read(&nr_mmap_events) && | |
6863 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
6864 | return; |
6865 | ||
9f498cc5 | 6866 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
6867 | .task = task, |
6868 | .task_ctx = task_ctx, | |
cdd6c482 | 6869 | .event_id = { |
60313ebe | 6870 | .header = { |
cdd6c482 | 6871 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 6872 | .misc = 0, |
cdd6c482 | 6873 | .size = sizeof(task_event.event_id), |
60313ebe | 6874 | }, |
573402db PZ |
6875 | /* .pid */ |
6876 | /* .ppid */ | |
9f498cc5 PZ |
6877 | /* .tid */ |
6878 | /* .ptid */ | |
34f43927 | 6879 | /* .time */ |
60313ebe PZ |
6880 | }, |
6881 | }; | |
6882 | ||
aab5b71e | 6883 | perf_iterate_sb(perf_event_task_output, |
52d857a8 JO |
6884 | &task_event, |
6885 | task_ctx); | |
9f498cc5 PZ |
6886 | } |
6887 | ||
cdd6c482 | 6888 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 6889 | { |
cdd6c482 | 6890 | perf_event_task(task, NULL, 1); |
e4222673 | 6891 | perf_event_namespaces(task); |
60313ebe PZ |
6892 | } |
6893 | ||
8d1b2d93 PZ |
6894 | /* |
6895 | * comm tracking | |
6896 | */ | |
6897 | ||
6898 | struct perf_comm_event { | |
22a4f650 IM |
6899 | struct task_struct *task; |
6900 | char *comm; | |
8d1b2d93 PZ |
6901 | int comm_size; |
6902 | ||
6903 | struct { | |
6904 | struct perf_event_header header; | |
6905 | ||
6906 | u32 pid; | |
6907 | u32 tid; | |
cdd6c482 | 6908 | } event_id; |
8d1b2d93 PZ |
6909 | }; |
6910 | ||
67516844 JO |
6911 | static int perf_event_comm_match(struct perf_event *event) |
6912 | { | |
6913 | return event->attr.comm; | |
6914 | } | |
6915 | ||
cdd6c482 | 6916 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 6917 | void *data) |
8d1b2d93 | 6918 | { |
52d857a8 | 6919 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 6920 | struct perf_output_handle handle; |
c980d109 | 6921 | struct perf_sample_data sample; |
cdd6c482 | 6922 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
6923 | int ret; |
6924 | ||
67516844 JO |
6925 | if (!perf_event_comm_match(event)) |
6926 | return; | |
6927 | ||
c980d109 ACM |
6928 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
6929 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6930 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
6931 | |
6932 | if (ret) | |
c980d109 | 6933 | goto out; |
8d1b2d93 | 6934 | |
cdd6c482 IM |
6935 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
6936 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 6937 | |
cdd6c482 | 6938 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 6939 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 6940 | comm_event->comm_size); |
c980d109 ACM |
6941 | |
6942 | perf_event__output_id_sample(event, &handle, &sample); | |
6943 | ||
8d1b2d93 | 6944 | perf_output_end(&handle); |
c980d109 ACM |
6945 | out: |
6946 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
6947 | } |
6948 | ||
cdd6c482 | 6949 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 6950 | { |
413ee3b4 | 6951 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 6952 | unsigned int size; |
8d1b2d93 | 6953 | |
413ee3b4 | 6954 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 6955 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 6956 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
6957 | |
6958 | comm_event->comm = comm; | |
6959 | comm_event->comm_size = size; | |
6960 | ||
cdd6c482 | 6961 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 6962 | |
aab5b71e | 6963 | perf_iterate_sb(perf_event_comm_output, |
52d857a8 JO |
6964 | comm_event, |
6965 | NULL); | |
8d1b2d93 PZ |
6966 | } |
6967 | ||
82b89778 | 6968 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 6969 | { |
9ee318a7 PZ |
6970 | struct perf_comm_event comm_event; |
6971 | ||
cdd6c482 | 6972 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 6973 | return; |
a63eaf34 | 6974 | |
9ee318a7 | 6975 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 6976 | .task = task, |
573402db PZ |
6977 | /* .comm */ |
6978 | /* .comm_size */ | |
cdd6c482 | 6979 | .event_id = { |
573402db | 6980 | .header = { |
cdd6c482 | 6981 | .type = PERF_RECORD_COMM, |
82b89778 | 6982 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
6983 | /* .size */ |
6984 | }, | |
6985 | /* .pid */ | |
6986 | /* .tid */ | |
8d1b2d93 PZ |
6987 | }, |
6988 | }; | |
6989 | ||
cdd6c482 | 6990 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
6991 | } |
6992 | ||
e4222673 HB |
6993 | /* |
6994 | * namespaces tracking | |
6995 | */ | |
6996 | ||
6997 | struct perf_namespaces_event { | |
6998 | struct task_struct *task; | |
6999 | ||
7000 | struct { | |
7001 | struct perf_event_header header; | |
7002 | ||
7003 | u32 pid; | |
7004 | u32 tid; | |
7005 | u64 nr_namespaces; | |
7006 | struct perf_ns_link_info link_info[NR_NAMESPACES]; | |
7007 | } event_id; | |
7008 | }; | |
7009 | ||
7010 | static int perf_event_namespaces_match(struct perf_event *event) | |
7011 | { | |
7012 | return event->attr.namespaces; | |
7013 | } | |
7014 | ||
7015 | static void perf_event_namespaces_output(struct perf_event *event, | |
7016 | void *data) | |
7017 | { | |
7018 | struct perf_namespaces_event *namespaces_event = data; | |
7019 | struct perf_output_handle handle; | |
7020 | struct perf_sample_data sample; | |
34900ec5 | 7021 | u16 header_size = namespaces_event->event_id.header.size; |
e4222673 HB |
7022 | int ret; |
7023 | ||
7024 | if (!perf_event_namespaces_match(event)) | |
7025 | return; | |
7026 | ||
7027 | perf_event_header__init_id(&namespaces_event->event_id.header, | |
7028 | &sample, event); | |
7029 | ret = perf_output_begin(&handle, event, | |
7030 | namespaces_event->event_id.header.size); | |
7031 | if (ret) | |
34900ec5 | 7032 | goto out; |
e4222673 HB |
7033 | |
7034 | namespaces_event->event_id.pid = perf_event_pid(event, | |
7035 | namespaces_event->task); | |
7036 | namespaces_event->event_id.tid = perf_event_tid(event, | |
7037 | namespaces_event->task); | |
7038 | ||
7039 | perf_output_put(&handle, namespaces_event->event_id); | |
7040 | ||
7041 | perf_event__output_id_sample(event, &handle, &sample); | |
7042 | ||
7043 | perf_output_end(&handle); | |
34900ec5 JO |
7044 | out: |
7045 | namespaces_event->event_id.header.size = header_size; | |
e4222673 HB |
7046 | } |
7047 | ||
7048 | static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, | |
7049 | struct task_struct *task, | |
7050 | const struct proc_ns_operations *ns_ops) | |
7051 | { | |
7052 | struct path ns_path; | |
7053 | struct inode *ns_inode; | |
7054 | void *error; | |
7055 | ||
7056 | error = ns_get_path(&ns_path, task, ns_ops); | |
7057 | if (!error) { | |
7058 | ns_inode = ns_path.dentry->d_inode; | |
7059 | ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev); | |
7060 | ns_link_info->ino = ns_inode->i_ino; | |
0e18dd12 | 7061 | path_put(&ns_path); |
e4222673 HB |
7062 | } |
7063 | } | |
7064 | ||
7065 | void perf_event_namespaces(struct task_struct *task) | |
7066 | { | |
7067 | struct perf_namespaces_event namespaces_event; | |
7068 | struct perf_ns_link_info *ns_link_info; | |
7069 | ||
7070 | if (!atomic_read(&nr_namespaces_events)) | |
7071 | return; | |
7072 | ||
7073 | namespaces_event = (struct perf_namespaces_event){ | |
7074 | .task = task, | |
7075 | .event_id = { | |
7076 | .header = { | |
7077 | .type = PERF_RECORD_NAMESPACES, | |
7078 | .misc = 0, | |
7079 | .size = sizeof(namespaces_event.event_id), | |
7080 | }, | |
7081 | /* .pid */ | |
7082 | /* .tid */ | |
7083 | .nr_namespaces = NR_NAMESPACES, | |
7084 | /* .link_info[NR_NAMESPACES] */ | |
7085 | }, | |
7086 | }; | |
7087 | ||
7088 | ns_link_info = namespaces_event.event_id.link_info; | |
7089 | ||
7090 | perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX], | |
7091 | task, &mntns_operations); | |
7092 | ||
7093 | #ifdef CONFIG_USER_NS | |
7094 | perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX], | |
7095 | task, &userns_operations); | |
7096 | #endif | |
7097 | #ifdef CONFIG_NET_NS | |
7098 | perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX], | |
7099 | task, &netns_operations); | |
7100 | #endif | |
7101 | #ifdef CONFIG_UTS_NS | |
7102 | perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX], | |
7103 | task, &utsns_operations); | |
7104 | #endif | |
7105 | #ifdef CONFIG_IPC_NS | |
7106 | perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX], | |
7107 | task, &ipcns_operations); | |
7108 | #endif | |
7109 | #ifdef CONFIG_PID_NS | |
7110 | perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX], | |
7111 | task, &pidns_operations); | |
7112 | #endif | |
7113 | #ifdef CONFIG_CGROUPS | |
7114 | perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX], | |
7115 | task, &cgroupns_operations); | |
7116 | #endif | |
7117 | ||
7118 | perf_iterate_sb(perf_event_namespaces_output, | |
7119 | &namespaces_event, | |
7120 | NULL); | |
7121 | } | |
7122 | ||
0a4a9391 PZ |
7123 | /* |
7124 | * mmap tracking | |
7125 | */ | |
7126 | ||
7127 | struct perf_mmap_event { | |
089dd79d PZ |
7128 | struct vm_area_struct *vma; |
7129 | ||
7130 | const char *file_name; | |
7131 | int file_size; | |
13d7a241 SE |
7132 | int maj, min; |
7133 | u64 ino; | |
7134 | u64 ino_generation; | |
f972eb63 | 7135 | u32 prot, flags; |
0a4a9391 PZ |
7136 | |
7137 | struct { | |
7138 | struct perf_event_header header; | |
7139 | ||
7140 | u32 pid; | |
7141 | u32 tid; | |
7142 | u64 start; | |
7143 | u64 len; | |
7144 | u64 pgoff; | |
cdd6c482 | 7145 | } event_id; |
0a4a9391 PZ |
7146 | }; |
7147 | ||
67516844 JO |
7148 | static int perf_event_mmap_match(struct perf_event *event, |
7149 | void *data) | |
7150 | { | |
7151 | struct perf_mmap_event *mmap_event = data; | |
7152 | struct vm_area_struct *vma = mmap_event->vma; | |
7153 | int executable = vma->vm_flags & VM_EXEC; | |
7154 | ||
7155 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 7156 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
7157 | } |
7158 | ||
cdd6c482 | 7159 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 7160 | void *data) |
0a4a9391 | 7161 | { |
52d857a8 | 7162 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 7163 | struct perf_output_handle handle; |
c980d109 | 7164 | struct perf_sample_data sample; |
cdd6c482 | 7165 | int size = mmap_event->event_id.header.size; |
c980d109 | 7166 | int ret; |
0a4a9391 | 7167 | |
67516844 JO |
7168 | if (!perf_event_mmap_match(event, data)) |
7169 | return; | |
7170 | ||
13d7a241 SE |
7171 | if (event->attr.mmap2) { |
7172 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
7173 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
7174 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
7175 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 7176 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
7177 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
7178 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
7179 | } |
7180 | ||
c980d109 ACM |
7181 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
7182 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 7183 | mmap_event->event_id.header.size); |
0a4a9391 | 7184 | if (ret) |
c980d109 | 7185 | goto out; |
0a4a9391 | 7186 | |
cdd6c482 IM |
7187 | mmap_event->event_id.pid = perf_event_pid(event, current); |
7188 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 7189 | |
cdd6c482 | 7190 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
7191 | |
7192 | if (event->attr.mmap2) { | |
7193 | perf_output_put(&handle, mmap_event->maj); | |
7194 | perf_output_put(&handle, mmap_event->min); | |
7195 | perf_output_put(&handle, mmap_event->ino); | |
7196 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
7197 | perf_output_put(&handle, mmap_event->prot); |
7198 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
7199 | } |
7200 | ||
76369139 | 7201 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 7202 | mmap_event->file_size); |
c980d109 ACM |
7203 | |
7204 | perf_event__output_id_sample(event, &handle, &sample); | |
7205 | ||
78d613eb | 7206 | perf_output_end(&handle); |
c980d109 ACM |
7207 | out: |
7208 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
7209 | } |
7210 | ||
cdd6c482 | 7211 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 7212 | { |
089dd79d PZ |
7213 | struct vm_area_struct *vma = mmap_event->vma; |
7214 | struct file *file = vma->vm_file; | |
13d7a241 SE |
7215 | int maj = 0, min = 0; |
7216 | u64 ino = 0, gen = 0; | |
f972eb63 | 7217 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
7218 | unsigned int size; |
7219 | char tmp[16]; | |
7220 | char *buf = NULL; | |
2c42cfbf | 7221 | char *name; |
413ee3b4 | 7222 | |
0b3589be PZ |
7223 | if (vma->vm_flags & VM_READ) |
7224 | prot |= PROT_READ; | |
7225 | if (vma->vm_flags & VM_WRITE) | |
7226 | prot |= PROT_WRITE; | |
7227 | if (vma->vm_flags & VM_EXEC) | |
7228 | prot |= PROT_EXEC; | |
7229 | ||
7230 | if (vma->vm_flags & VM_MAYSHARE) | |
7231 | flags = MAP_SHARED; | |
7232 | else | |
7233 | flags = MAP_PRIVATE; | |
7234 | ||
7235 | if (vma->vm_flags & VM_DENYWRITE) | |
7236 | flags |= MAP_DENYWRITE; | |
7237 | if (vma->vm_flags & VM_MAYEXEC) | |
7238 | flags |= MAP_EXECUTABLE; | |
7239 | if (vma->vm_flags & VM_LOCKED) | |
7240 | flags |= MAP_LOCKED; | |
7241 | if (vma->vm_flags & VM_HUGETLB) | |
7242 | flags |= MAP_HUGETLB; | |
7243 | ||
0a4a9391 | 7244 | if (file) { |
13d7a241 SE |
7245 | struct inode *inode; |
7246 | dev_t dev; | |
3ea2f2b9 | 7247 | |
2c42cfbf | 7248 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 7249 | if (!buf) { |
c7e548b4 ON |
7250 | name = "//enomem"; |
7251 | goto cpy_name; | |
0a4a9391 | 7252 | } |
413ee3b4 | 7253 | /* |
3ea2f2b9 | 7254 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
7255 | * need to add enough zero bytes after the string to handle |
7256 | * the 64bit alignment we do later. | |
7257 | */ | |
9bf39ab2 | 7258 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 7259 | if (IS_ERR(name)) { |
c7e548b4 ON |
7260 | name = "//toolong"; |
7261 | goto cpy_name; | |
0a4a9391 | 7262 | } |
13d7a241 SE |
7263 | inode = file_inode(vma->vm_file); |
7264 | dev = inode->i_sb->s_dev; | |
7265 | ino = inode->i_ino; | |
7266 | gen = inode->i_generation; | |
7267 | maj = MAJOR(dev); | |
7268 | min = MINOR(dev); | |
f972eb63 | 7269 | |
c7e548b4 | 7270 | goto got_name; |
0a4a9391 | 7271 | } else { |
fbe26abe JO |
7272 | if (vma->vm_ops && vma->vm_ops->name) { |
7273 | name = (char *) vma->vm_ops->name(vma); | |
7274 | if (name) | |
7275 | goto cpy_name; | |
7276 | } | |
7277 | ||
2c42cfbf | 7278 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
7279 | if (name) |
7280 | goto cpy_name; | |
089dd79d | 7281 | |
32c5fb7e | 7282 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 7283 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
7284 | name = "[heap]"; |
7285 | goto cpy_name; | |
32c5fb7e ON |
7286 | } |
7287 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 7288 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
7289 | name = "[stack]"; |
7290 | goto cpy_name; | |
089dd79d PZ |
7291 | } |
7292 | ||
c7e548b4 ON |
7293 | name = "//anon"; |
7294 | goto cpy_name; | |
0a4a9391 PZ |
7295 | } |
7296 | ||
c7e548b4 ON |
7297 | cpy_name: |
7298 | strlcpy(tmp, name, sizeof(tmp)); | |
7299 | name = tmp; | |
0a4a9391 | 7300 | got_name: |
2c42cfbf PZ |
7301 | /* |
7302 | * Since our buffer works in 8 byte units we need to align our string | |
7303 | * size to a multiple of 8. However, we must guarantee the tail end is | |
7304 | * zero'd out to avoid leaking random bits to userspace. | |
7305 | */ | |
7306 | size = strlen(name)+1; | |
7307 | while (!IS_ALIGNED(size, sizeof(u64))) | |
7308 | name[size++] = '\0'; | |
0a4a9391 PZ |
7309 | |
7310 | mmap_event->file_name = name; | |
7311 | mmap_event->file_size = size; | |
13d7a241 SE |
7312 | mmap_event->maj = maj; |
7313 | mmap_event->min = min; | |
7314 | mmap_event->ino = ino; | |
7315 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
7316 | mmap_event->prot = prot; |
7317 | mmap_event->flags = flags; | |
0a4a9391 | 7318 | |
2fe85427 SE |
7319 | if (!(vma->vm_flags & VM_EXEC)) |
7320 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
7321 | ||
cdd6c482 | 7322 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 7323 | |
aab5b71e | 7324 | perf_iterate_sb(perf_event_mmap_output, |
52d857a8 JO |
7325 | mmap_event, |
7326 | NULL); | |
665c2142 | 7327 | |
0a4a9391 PZ |
7328 | kfree(buf); |
7329 | } | |
7330 | ||
375637bc AS |
7331 | /* |
7332 | * Check whether inode and address range match filter criteria. | |
7333 | */ | |
7334 | static bool perf_addr_filter_match(struct perf_addr_filter *filter, | |
7335 | struct file *file, unsigned long offset, | |
7336 | unsigned long size) | |
7337 | { | |
9511bce9 | 7338 | if (d_inode(filter->path.dentry) != file_inode(file)) |
375637bc AS |
7339 | return false; |
7340 | ||
7341 | if (filter->offset > offset + size) | |
7342 | return false; | |
7343 | ||
7344 | if (filter->offset + filter->size < offset) | |
7345 | return false; | |
7346 | ||
7347 | return true; | |
7348 | } | |
7349 | ||
7350 | static void __perf_addr_filters_adjust(struct perf_event *event, void *data) | |
7351 | { | |
7352 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
7353 | struct vm_area_struct *vma = data; | |
7354 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags; | |
7355 | struct file *file = vma->vm_file; | |
7356 | struct perf_addr_filter *filter; | |
7357 | unsigned int restart = 0, count = 0; | |
7358 | ||
7359 | if (!has_addr_filter(event)) | |
7360 | return; | |
7361 | ||
7362 | if (!file) | |
7363 | return; | |
7364 | ||
7365 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
7366 | list_for_each_entry(filter, &ifh->list, entry) { | |
7367 | if (perf_addr_filter_match(filter, file, off, | |
7368 | vma->vm_end - vma->vm_start)) { | |
7369 | event->addr_filters_offs[count] = vma->vm_start; | |
7370 | restart++; | |
7371 | } | |
7372 | ||
7373 | count++; | |
7374 | } | |
7375 | ||
7376 | if (restart) | |
7377 | event->addr_filters_gen++; | |
7378 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
7379 | ||
7380 | if (restart) | |
767ae086 | 7381 | perf_event_stop(event, 1); |
375637bc AS |
7382 | } |
7383 | ||
7384 | /* | |
7385 | * Adjust all task's events' filters to the new vma | |
7386 | */ | |
7387 | static void perf_addr_filters_adjust(struct vm_area_struct *vma) | |
7388 | { | |
7389 | struct perf_event_context *ctx; | |
7390 | int ctxn; | |
7391 | ||
12b40a23 MP |
7392 | /* |
7393 | * Data tracing isn't supported yet and as such there is no need | |
7394 | * to keep track of anything that isn't related to executable code: | |
7395 | */ | |
7396 | if (!(vma->vm_flags & VM_EXEC)) | |
7397 | return; | |
7398 | ||
375637bc AS |
7399 | rcu_read_lock(); |
7400 | for_each_task_context_nr(ctxn) { | |
7401 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
7402 | if (!ctx) | |
7403 | continue; | |
7404 | ||
aab5b71e | 7405 | perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true); |
375637bc AS |
7406 | } |
7407 | rcu_read_unlock(); | |
7408 | } | |
7409 | ||
3af9e859 | 7410 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 7411 | { |
9ee318a7 PZ |
7412 | struct perf_mmap_event mmap_event; |
7413 | ||
cdd6c482 | 7414 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
7415 | return; |
7416 | ||
7417 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 7418 | .vma = vma, |
573402db PZ |
7419 | /* .file_name */ |
7420 | /* .file_size */ | |
cdd6c482 | 7421 | .event_id = { |
573402db | 7422 | .header = { |
cdd6c482 | 7423 | .type = PERF_RECORD_MMAP, |
39447b38 | 7424 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
7425 | /* .size */ |
7426 | }, | |
7427 | /* .pid */ | |
7428 | /* .tid */ | |
089dd79d PZ |
7429 | .start = vma->vm_start, |
7430 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 7431 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 7432 | }, |
13d7a241 SE |
7433 | /* .maj (attr_mmap2 only) */ |
7434 | /* .min (attr_mmap2 only) */ | |
7435 | /* .ino (attr_mmap2 only) */ | |
7436 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
7437 | /* .prot (attr_mmap2 only) */ |
7438 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
7439 | }; |
7440 | ||
375637bc | 7441 | perf_addr_filters_adjust(vma); |
cdd6c482 | 7442 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
7443 | } |
7444 | ||
68db7e98 AS |
7445 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
7446 | unsigned long size, u64 flags) | |
7447 | { | |
7448 | struct perf_output_handle handle; | |
7449 | struct perf_sample_data sample; | |
7450 | struct perf_aux_event { | |
7451 | struct perf_event_header header; | |
7452 | u64 offset; | |
7453 | u64 size; | |
7454 | u64 flags; | |
7455 | } rec = { | |
7456 | .header = { | |
7457 | .type = PERF_RECORD_AUX, | |
7458 | .misc = 0, | |
7459 | .size = sizeof(rec), | |
7460 | }, | |
7461 | .offset = head, | |
7462 | .size = size, | |
7463 | .flags = flags, | |
7464 | }; | |
7465 | int ret; | |
7466 | ||
7467 | perf_event_header__init_id(&rec.header, &sample, event); | |
7468 | ret = perf_output_begin(&handle, event, rec.header.size); | |
7469 | ||
7470 | if (ret) | |
7471 | return; | |
7472 | ||
7473 | perf_output_put(&handle, rec); | |
7474 | perf_event__output_id_sample(event, &handle, &sample); | |
7475 | ||
7476 | perf_output_end(&handle); | |
7477 | } | |
7478 | ||
f38b0dbb KL |
7479 | /* |
7480 | * Lost/dropped samples logging | |
7481 | */ | |
7482 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
7483 | { | |
7484 | struct perf_output_handle handle; | |
7485 | struct perf_sample_data sample; | |
7486 | int ret; | |
7487 | ||
7488 | struct { | |
7489 | struct perf_event_header header; | |
7490 | u64 lost; | |
7491 | } lost_samples_event = { | |
7492 | .header = { | |
7493 | .type = PERF_RECORD_LOST_SAMPLES, | |
7494 | .misc = 0, | |
7495 | .size = sizeof(lost_samples_event), | |
7496 | }, | |
7497 | .lost = lost, | |
7498 | }; | |
7499 | ||
7500 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
7501 | ||
7502 | ret = perf_output_begin(&handle, event, | |
7503 | lost_samples_event.header.size); | |
7504 | if (ret) | |
7505 | return; | |
7506 | ||
7507 | perf_output_put(&handle, lost_samples_event); | |
7508 | perf_event__output_id_sample(event, &handle, &sample); | |
7509 | perf_output_end(&handle); | |
7510 | } | |
7511 | ||
45ac1403 AH |
7512 | /* |
7513 | * context_switch tracking | |
7514 | */ | |
7515 | ||
7516 | struct perf_switch_event { | |
7517 | struct task_struct *task; | |
7518 | struct task_struct *next_prev; | |
7519 | ||
7520 | struct { | |
7521 | struct perf_event_header header; | |
7522 | u32 next_prev_pid; | |
7523 | u32 next_prev_tid; | |
7524 | } event_id; | |
7525 | }; | |
7526 | ||
7527 | static int perf_event_switch_match(struct perf_event *event) | |
7528 | { | |
7529 | return event->attr.context_switch; | |
7530 | } | |
7531 | ||
7532 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
7533 | { | |
7534 | struct perf_switch_event *se = data; | |
7535 | struct perf_output_handle handle; | |
7536 | struct perf_sample_data sample; | |
7537 | int ret; | |
7538 | ||
7539 | if (!perf_event_switch_match(event)) | |
7540 | return; | |
7541 | ||
7542 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
7543 | if (event->ctx->task) { | |
7544 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
7545 | se->event_id.header.size = sizeof(se->event_id.header); | |
7546 | } else { | |
7547 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
7548 | se->event_id.header.size = sizeof(se->event_id); | |
7549 | se->event_id.next_prev_pid = | |
7550 | perf_event_pid(event, se->next_prev); | |
7551 | se->event_id.next_prev_tid = | |
7552 | perf_event_tid(event, se->next_prev); | |
7553 | } | |
7554 | ||
7555 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
7556 | ||
7557 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
7558 | if (ret) | |
7559 | return; | |
7560 | ||
7561 | if (event->ctx->task) | |
7562 | perf_output_put(&handle, se->event_id.header); | |
7563 | else | |
7564 | perf_output_put(&handle, se->event_id); | |
7565 | ||
7566 | perf_event__output_id_sample(event, &handle, &sample); | |
7567 | ||
7568 | perf_output_end(&handle); | |
7569 | } | |
7570 | ||
7571 | static void perf_event_switch(struct task_struct *task, | |
7572 | struct task_struct *next_prev, bool sched_in) | |
7573 | { | |
7574 | struct perf_switch_event switch_event; | |
7575 | ||
7576 | /* N.B. caller checks nr_switch_events != 0 */ | |
7577 | ||
7578 | switch_event = (struct perf_switch_event){ | |
7579 | .task = task, | |
7580 | .next_prev = next_prev, | |
7581 | .event_id = { | |
7582 | .header = { | |
7583 | /* .type */ | |
7584 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
7585 | /* .size */ | |
7586 | }, | |
7587 | /* .next_prev_pid */ | |
7588 | /* .next_prev_tid */ | |
7589 | }, | |
7590 | }; | |
7591 | ||
101592b4 AB |
7592 | if (!sched_in && task->state == TASK_RUNNING) |
7593 | switch_event.event_id.header.misc |= | |
7594 | PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; | |
7595 | ||
aab5b71e | 7596 | perf_iterate_sb(perf_event_switch_output, |
45ac1403 AH |
7597 | &switch_event, |
7598 | NULL); | |
7599 | } | |
7600 | ||
a78ac325 PZ |
7601 | /* |
7602 | * IRQ throttle logging | |
7603 | */ | |
7604 | ||
cdd6c482 | 7605 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
7606 | { |
7607 | struct perf_output_handle handle; | |
c980d109 | 7608 | struct perf_sample_data sample; |
a78ac325 PZ |
7609 | int ret; |
7610 | ||
7611 | struct { | |
7612 | struct perf_event_header header; | |
7613 | u64 time; | |
cca3f454 | 7614 | u64 id; |
7f453c24 | 7615 | u64 stream_id; |
a78ac325 PZ |
7616 | } throttle_event = { |
7617 | .header = { | |
cdd6c482 | 7618 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
7619 | .misc = 0, |
7620 | .size = sizeof(throttle_event), | |
7621 | }, | |
34f43927 | 7622 | .time = perf_event_clock(event), |
cdd6c482 IM |
7623 | .id = primary_event_id(event), |
7624 | .stream_id = event->id, | |
a78ac325 PZ |
7625 | }; |
7626 | ||
966ee4d6 | 7627 | if (enable) |
cdd6c482 | 7628 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 7629 | |
c980d109 ACM |
7630 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
7631 | ||
7632 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 7633 | throttle_event.header.size); |
a78ac325 PZ |
7634 | if (ret) |
7635 | return; | |
7636 | ||
7637 | perf_output_put(&handle, throttle_event); | |
c980d109 | 7638 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
7639 | perf_output_end(&handle); |
7640 | } | |
7641 | ||
8d4e6c4c AS |
7642 | void perf_event_itrace_started(struct perf_event *event) |
7643 | { | |
7644 | event->attach_state |= PERF_ATTACH_ITRACE; | |
7645 | } | |
7646 | ||
ec0d7729 AS |
7647 | static void perf_log_itrace_start(struct perf_event *event) |
7648 | { | |
7649 | struct perf_output_handle handle; | |
7650 | struct perf_sample_data sample; | |
7651 | struct perf_aux_event { | |
7652 | struct perf_event_header header; | |
7653 | u32 pid; | |
7654 | u32 tid; | |
7655 | } rec; | |
7656 | int ret; | |
7657 | ||
7658 | if (event->parent) | |
7659 | event = event->parent; | |
7660 | ||
7661 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
8d4e6c4c | 7662 | event->attach_state & PERF_ATTACH_ITRACE) |
ec0d7729 AS |
7663 | return; |
7664 | ||
ec0d7729 AS |
7665 | rec.header.type = PERF_RECORD_ITRACE_START; |
7666 | rec.header.misc = 0; | |
7667 | rec.header.size = sizeof(rec); | |
7668 | rec.pid = perf_event_pid(event, current); | |
7669 | rec.tid = perf_event_tid(event, current); | |
7670 | ||
7671 | perf_event_header__init_id(&rec.header, &sample, event); | |
7672 | ret = perf_output_begin(&handle, event, rec.header.size); | |
7673 | ||
7674 | if (ret) | |
7675 | return; | |
7676 | ||
7677 | perf_output_put(&handle, rec); | |
7678 | perf_event__output_id_sample(event, &handle, &sample); | |
7679 | ||
7680 | perf_output_end(&handle); | |
7681 | } | |
7682 | ||
475113d9 JO |
7683 | static int |
7684 | __perf_event_account_interrupt(struct perf_event *event, int throttle) | |
f6c7d5fe | 7685 | { |
cdd6c482 | 7686 | struct hw_perf_event *hwc = &event->hw; |
79f14641 | 7687 | int ret = 0; |
475113d9 | 7688 | u64 seq; |
96398826 | 7689 | |
e050e3f0 SE |
7690 | seq = __this_cpu_read(perf_throttled_seq); |
7691 | if (seq != hwc->interrupts_seq) { | |
7692 | hwc->interrupts_seq = seq; | |
7693 | hwc->interrupts = 1; | |
7694 | } else { | |
7695 | hwc->interrupts++; | |
7696 | if (unlikely(throttle | |
7697 | && hwc->interrupts >= max_samples_per_tick)) { | |
7698 | __this_cpu_inc(perf_throttled_count); | |
555e0c1e | 7699 | tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
163ec435 PZ |
7700 | hwc->interrupts = MAX_INTERRUPTS; |
7701 | perf_log_throttle(event, 0); | |
a78ac325 PZ |
7702 | ret = 1; |
7703 | } | |
e050e3f0 | 7704 | } |
60db5e09 | 7705 | |
cdd6c482 | 7706 | if (event->attr.freq) { |
def0a9b2 | 7707 | u64 now = perf_clock(); |
abd50713 | 7708 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 7709 | |
abd50713 | 7710 | hwc->freq_time_stamp = now; |
bd2b5b12 | 7711 | |
abd50713 | 7712 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 7713 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
7714 | } |
7715 | ||
475113d9 JO |
7716 | return ret; |
7717 | } | |
7718 | ||
7719 | int perf_event_account_interrupt(struct perf_event *event) | |
7720 | { | |
7721 | return __perf_event_account_interrupt(event, 1); | |
7722 | } | |
7723 | ||
7724 | /* | |
7725 | * Generic event overflow handling, sampling. | |
7726 | */ | |
7727 | ||
7728 | static int __perf_event_overflow(struct perf_event *event, | |
7729 | int throttle, struct perf_sample_data *data, | |
7730 | struct pt_regs *regs) | |
7731 | { | |
7732 | int events = atomic_read(&event->event_limit); | |
7733 | int ret = 0; | |
7734 | ||
7735 | /* | |
7736 | * Non-sampling counters might still use the PMI to fold short | |
7737 | * hardware counters, ignore those. | |
7738 | */ | |
7739 | if (unlikely(!is_sampling_event(event))) | |
7740 | return 0; | |
7741 | ||
7742 | ret = __perf_event_account_interrupt(event, throttle); | |
cc1582c2 | 7743 | |
2023b359 PZ |
7744 | /* |
7745 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 7746 | * events |
2023b359 PZ |
7747 | */ |
7748 | ||
cdd6c482 IM |
7749 | event->pending_kill = POLL_IN; |
7750 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 7751 | ret = 1; |
cdd6c482 | 7752 | event->pending_kill = POLL_HUP; |
5aab90ce JO |
7753 | |
7754 | perf_event_disable_inatomic(event); | |
79f14641 PZ |
7755 | } |
7756 | ||
aa6a5f3c | 7757 | READ_ONCE(event->overflow_handler)(event, data, regs); |
453f19ee | 7758 | |
fed66e2c | 7759 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
7760 | event->pending_wakeup = 1; |
7761 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
7762 | } |
7763 | ||
79f14641 | 7764 | return ret; |
f6c7d5fe PZ |
7765 | } |
7766 | ||
a8b0ca17 | 7767 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
7768 | struct perf_sample_data *data, |
7769 | struct pt_regs *regs) | |
850bc73f | 7770 | { |
a8b0ca17 | 7771 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
7772 | } |
7773 | ||
15dbf27c | 7774 | /* |
cdd6c482 | 7775 | * Generic software event infrastructure |
15dbf27c PZ |
7776 | */ |
7777 | ||
b28ab83c PZ |
7778 | struct swevent_htable { |
7779 | struct swevent_hlist *swevent_hlist; | |
7780 | struct mutex hlist_mutex; | |
7781 | int hlist_refcount; | |
7782 | ||
7783 | /* Recursion avoidance in each contexts */ | |
7784 | int recursion[PERF_NR_CONTEXTS]; | |
7785 | }; | |
7786 | ||
7787 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
7788 | ||
7b4b6658 | 7789 | /* |
cdd6c482 IM |
7790 | * We directly increment event->count and keep a second value in |
7791 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
7792 | * is kept in the range [-sample_period, 0] so that we can use the |
7793 | * sign as trigger. | |
7794 | */ | |
7795 | ||
ab573844 | 7796 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 7797 | { |
cdd6c482 | 7798 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
7799 | u64 period = hwc->last_period; |
7800 | u64 nr, offset; | |
7801 | s64 old, val; | |
7802 | ||
7803 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
7804 | |
7805 | again: | |
e7850595 | 7806 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
7807 | if (val < 0) |
7808 | return 0; | |
15dbf27c | 7809 | |
7b4b6658 PZ |
7810 | nr = div64_u64(period + val, period); |
7811 | offset = nr * period; | |
7812 | val -= offset; | |
e7850595 | 7813 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 7814 | goto again; |
15dbf27c | 7815 | |
7b4b6658 | 7816 | return nr; |
15dbf27c PZ |
7817 | } |
7818 | ||
0cff784a | 7819 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 7820 | struct perf_sample_data *data, |
5622f295 | 7821 | struct pt_regs *regs) |
15dbf27c | 7822 | { |
cdd6c482 | 7823 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 7824 | int throttle = 0; |
15dbf27c | 7825 | |
0cff784a PZ |
7826 | if (!overflow) |
7827 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 7828 | |
7b4b6658 PZ |
7829 | if (hwc->interrupts == MAX_INTERRUPTS) |
7830 | return; | |
15dbf27c | 7831 | |
7b4b6658 | 7832 | for (; overflow; overflow--) { |
a8b0ca17 | 7833 | if (__perf_event_overflow(event, throttle, |
5622f295 | 7834 | data, regs)) { |
7b4b6658 PZ |
7835 | /* |
7836 | * We inhibit the overflow from happening when | |
7837 | * hwc->interrupts == MAX_INTERRUPTS. | |
7838 | */ | |
7839 | break; | |
7840 | } | |
cf450a73 | 7841 | throttle = 1; |
7b4b6658 | 7842 | } |
15dbf27c PZ |
7843 | } |
7844 | ||
a4eaf7f1 | 7845 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 7846 | struct perf_sample_data *data, |
5622f295 | 7847 | struct pt_regs *regs) |
7b4b6658 | 7848 | { |
cdd6c482 | 7849 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 7850 | |
e7850595 | 7851 | local64_add(nr, &event->count); |
d6d020e9 | 7852 | |
0cff784a PZ |
7853 | if (!regs) |
7854 | return; | |
7855 | ||
6c7e550f | 7856 | if (!is_sampling_event(event)) |
7b4b6658 | 7857 | return; |
d6d020e9 | 7858 | |
5d81e5cf AV |
7859 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
7860 | data->period = nr; | |
7861 | return perf_swevent_overflow(event, 1, data, regs); | |
7862 | } else | |
7863 | data->period = event->hw.last_period; | |
7864 | ||
0cff784a | 7865 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 7866 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 7867 | |
e7850595 | 7868 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 7869 | return; |
df1a132b | 7870 | |
a8b0ca17 | 7871 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
7872 | } |
7873 | ||
f5ffe02e FW |
7874 | static int perf_exclude_event(struct perf_event *event, |
7875 | struct pt_regs *regs) | |
7876 | { | |
a4eaf7f1 | 7877 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 7878 | return 1; |
a4eaf7f1 | 7879 | |
f5ffe02e FW |
7880 | if (regs) { |
7881 | if (event->attr.exclude_user && user_mode(regs)) | |
7882 | return 1; | |
7883 | ||
7884 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
7885 | return 1; | |
7886 | } | |
7887 | ||
7888 | return 0; | |
7889 | } | |
7890 | ||
cdd6c482 | 7891 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 7892 | enum perf_type_id type, |
6fb2915d LZ |
7893 | u32 event_id, |
7894 | struct perf_sample_data *data, | |
7895 | struct pt_regs *regs) | |
15dbf27c | 7896 | { |
cdd6c482 | 7897 | if (event->attr.type != type) |
a21ca2ca | 7898 | return 0; |
f5ffe02e | 7899 | |
cdd6c482 | 7900 | if (event->attr.config != event_id) |
15dbf27c PZ |
7901 | return 0; |
7902 | ||
f5ffe02e FW |
7903 | if (perf_exclude_event(event, regs)) |
7904 | return 0; | |
15dbf27c PZ |
7905 | |
7906 | return 1; | |
7907 | } | |
7908 | ||
76e1d904 FW |
7909 | static inline u64 swevent_hash(u64 type, u32 event_id) |
7910 | { | |
7911 | u64 val = event_id | (type << 32); | |
7912 | ||
7913 | return hash_64(val, SWEVENT_HLIST_BITS); | |
7914 | } | |
7915 | ||
49f135ed FW |
7916 | static inline struct hlist_head * |
7917 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 7918 | { |
49f135ed FW |
7919 | u64 hash = swevent_hash(type, event_id); |
7920 | ||
7921 | return &hlist->heads[hash]; | |
7922 | } | |
76e1d904 | 7923 | |
49f135ed FW |
7924 | /* For the read side: events when they trigger */ |
7925 | static inline struct hlist_head * | |
b28ab83c | 7926 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
7927 | { |
7928 | struct swevent_hlist *hlist; | |
76e1d904 | 7929 | |
b28ab83c | 7930 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
7931 | if (!hlist) |
7932 | return NULL; | |
7933 | ||
49f135ed FW |
7934 | return __find_swevent_head(hlist, type, event_id); |
7935 | } | |
7936 | ||
7937 | /* For the event head insertion and removal in the hlist */ | |
7938 | static inline struct hlist_head * | |
b28ab83c | 7939 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
7940 | { |
7941 | struct swevent_hlist *hlist; | |
7942 | u32 event_id = event->attr.config; | |
7943 | u64 type = event->attr.type; | |
7944 | ||
7945 | /* | |
7946 | * Event scheduling is always serialized against hlist allocation | |
7947 | * and release. Which makes the protected version suitable here. | |
7948 | * The context lock guarantees that. | |
7949 | */ | |
b28ab83c | 7950 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
7951 | lockdep_is_held(&event->ctx->lock)); |
7952 | if (!hlist) | |
7953 | return NULL; | |
7954 | ||
7955 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
7956 | } |
7957 | ||
7958 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 7959 | u64 nr, |
76e1d904 FW |
7960 | struct perf_sample_data *data, |
7961 | struct pt_regs *regs) | |
15dbf27c | 7962 | { |
4a32fea9 | 7963 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 7964 | struct perf_event *event; |
76e1d904 | 7965 | struct hlist_head *head; |
15dbf27c | 7966 | |
76e1d904 | 7967 | rcu_read_lock(); |
b28ab83c | 7968 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
7969 | if (!head) |
7970 | goto end; | |
7971 | ||
b67bfe0d | 7972 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 7973 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 7974 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 7975 | } |
76e1d904 FW |
7976 | end: |
7977 | rcu_read_unlock(); | |
15dbf27c PZ |
7978 | } |
7979 | ||
86038c5e PZI |
7980 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
7981 | ||
4ed7c92d | 7982 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 7983 | { |
4a32fea9 | 7984 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 7985 | |
b28ab83c | 7986 | return get_recursion_context(swhash->recursion); |
96f6d444 | 7987 | } |
645e8cc0 | 7988 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 7989 | |
98b5c2c6 | 7990 | void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 7991 | { |
4a32fea9 | 7992 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 7993 | |
b28ab83c | 7994 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 7995 | } |
15dbf27c | 7996 | |
86038c5e | 7997 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 7998 | { |
a4234bfc | 7999 | struct perf_sample_data data; |
4ed7c92d | 8000 | |
86038c5e | 8001 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 8002 | return; |
a4234bfc | 8003 | |
fd0d000b | 8004 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 8005 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
8006 | } |
8007 | ||
8008 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
8009 | { | |
8010 | int rctx; | |
8011 | ||
8012 | preempt_disable_notrace(); | |
8013 | rctx = perf_swevent_get_recursion_context(); | |
8014 | if (unlikely(rctx < 0)) | |
8015 | goto fail; | |
8016 | ||
8017 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
8018 | |
8019 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 8020 | fail: |
1c024eca | 8021 | preempt_enable_notrace(); |
b8e83514 PZ |
8022 | } |
8023 | ||
cdd6c482 | 8024 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 8025 | { |
15dbf27c PZ |
8026 | } |
8027 | ||
a4eaf7f1 | 8028 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 8029 | { |
4a32fea9 | 8030 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 8031 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
8032 | struct hlist_head *head; |
8033 | ||
6c7e550f | 8034 | if (is_sampling_event(event)) { |
7b4b6658 | 8035 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 8036 | perf_swevent_set_period(event); |
7b4b6658 | 8037 | } |
76e1d904 | 8038 | |
a4eaf7f1 PZ |
8039 | hwc->state = !(flags & PERF_EF_START); |
8040 | ||
b28ab83c | 8041 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 8042 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
8043 | return -EINVAL; |
8044 | ||
8045 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 8046 | perf_event_update_userpage(event); |
76e1d904 | 8047 | |
15dbf27c PZ |
8048 | return 0; |
8049 | } | |
8050 | ||
a4eaf7f1 | 8051 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 8052 | { |
76e1d904 | 8053 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
8054 | } |
8055 | ||
a4eaf7f1 | 8056 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 8057 | { |
a4eaf7f1 | 8058 | event->hw.state = 0; |
d6d020e9 | 8059 | } |
aa9c4c0f | 8060 | |
a4eaf7f1 | 8061 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 8062 | { |
a4eaf7f1 | 8063 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
8064 | } |
8065 | ||
49f135ed FW |
8066 | /* Deref the hlist from the update side */ |
8067 | static inline struct swevent_hlist * | |
b28ab83c | 8068 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 8069 | { |
b28ab83c PZ |
8070 | return rcu_dereference_protected(swhash->swevent_hlist, |
8071 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
8072 | } |
8073 | ||
b28ab83c | 8074 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 8075 | { |
b28ab83c | 8076 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 8077 | |
49f135ed | 8078 | if (!hlist) |
76e1d904 FW |
8079 | return; |
8080 | ||
70691d4a | 8081 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 8082 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
8083 | } |
8084 | ||
3b364d7b | 8085 | static void swevent_hlist_put_cpu(int cpu) |
76e1d904 | 8086 | { |
b28ab83c | 8087 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 8088 | |
b28ab83c | 8089 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 8090 | |
b28ab83c PZ |
8091 | if (!--swhash->hlist_refcount) |
8092 | swevent_hlist_release(swhash); | |
76e1d904 | 8093 | |
b28ab83c | 8094 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
8095 | } |
8096 | ||
3b364d7b | 8097 | static void swevent_hlist_put(void) |
76e1d904 FW |
8098 | { |
8099 | int cpu; | |
8100 | ||
76e1d904 | 8101 | for_each_possible_cpu(cpu) |
3b364d7b | 8102 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
8103 | } |
8104 | ||
3b364d7b | 8105 | static int swevent_hlist_get_cpu(int cpu) |
76e1d904 | 8106 | { |
b28ab83c | 8107 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
8108 | int err = 0; |
8109 | ||
b28ab83c | 8110 | mutex_lock(&swhash->hlist_mutex); |
a63fbed7 TG |
8111 | if (!swevent_hlist_deref(swhash) && |
8112 | cpumask_test_cpu(cpu, perf_online_mask)) { | |
76e1d904 FW |
8113 | struct swevent_hlist *hlist; |
8114 | ||
8115 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
8116 | if (!hlist) { | |
8117 | err = -ENOMEM; | |
8118 | goto exit; | |
8119 | } | |
b28ab83c | 8120 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 8121 | } |
b28ab83c | 8122 | swhash->hlist_refcount++; |
9ed6060d | 8123 | exit: |
b28ab83c | 8124 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
8125 | |
8126 | return err; | |
8127 | } | |
8128 | ||
3b364d7b | 8129 | static int swevent_hlist_get(void) |
76e1d904 | 8130 | { |
3b364d7b | 8131 | int err, cpu, failed_cpu; |
76e1d904 | 8132 | |
a63fbed7 | 8133 | mutex_lock(&pmus_lock); |
76e1d904 | 8134 | for_each_possible_cpu(cpu) { |
3b364d7b | 8135 | err = swevent_hlist_get_cpu(cpu); |
76e1d904 FW |
8136 | if (err) { |
8137 | failed_cpu = cpu; | |
8138 | goto fail; | |
8139 | } | |
8140 | } | |
a63fbed7 | 8141 | mutex_unlock(&pmus_lock); |
76e1d904 | 8142 | return 0; |
9ed6060d | 8143 | fail: |
76e1d904 FW |
8144 | for_each_possible_cpu(cpu) { |
8145 | if (cpu == failed_cpu) | |
8146 | break; | |
3b364d7b | 8147 | swevent_hlist_put_cpu(cpu); |
76e1d904 | 8148 | } |
a63fbed7 | 8149 | mutex_unlock(&pmus_lock); |
76e1d904 FW |
8150 | return err; |
8151 | } | |
8152 | ||
c5905afb | 8153 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 8154 | |
b0a873eb PZ |
8155 | static void sw_perf_event_destroy(struct perf_event *event) |
8156 | { | |
8157 | u64 event_id = event->attr.config; | |
95476b64 | 8158 | |
b0a873eb PZ |
8159 | WARN_ON(event->parent); |
8160 | ||
c5905afb | 8161 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
3b364d7b | 8162 | swevent_hlist_put(); |
b0a873eb PZ |
8163 | } |
8164 | ||
8165 | static int perf_swevent_init(struct perf_event *event) | |
8166 | { | |
8176cced | 8167 | u64 event_id = event->attr.config; |
b0a873eb PZ |
8168 | |
8169 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
8170 | return -ENOENT; | |
8171 | ||
2481c5fa SE |
8172 | /* |
8173 | * no branch sampling for software events | |
8174 | */ | |
8175 | if (has_branch_stack(event)) | |
8176 | return -EOPNOTSUPP; | |
8177 | ||
b0a873eb PZ |
8178 | switch (event_id) { |
8179 | case PERF_COUNT_SW_CPU_CLOCK: | |
8180 | case PERF_COUNT_SW_TASK_CLOCK: | |
8181 | return -ENOENT; | |
8182 | ||
8183 | default: | |
8184 | break; | |
8185 | } | |
8186 | ||
ce677831 | 8187 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
8188 | return -ENOENT; |
8189 | ||
8190 | if (!event->parent) { | |
8191 | int err; | |
8192 | ||
3b364d7b | 8193 | err = swevent_hlist_get(); |
b0a873eb PZ |
8194 | if (err) |
8195 | return err; | |
8196 | ||
c5905afb | 8197 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
8198 | event->destroy = sw_perf_event_destroy; |
8199 | } | |
8200 | ||
8201 | return 0; | |
8202 | } | |
8203 | ||
8204 | static struct pmu perf_swevent = { | |
89a1e187 | 8205 | .task_ctx_nr = perf_sw_context, |
95476b64 | 8206 | |
34f43927 PZ |
8207 | .capabilities = PERF_PMU_CAP_NO_NMI, |
8208 | ||
b0a873eb | 8209 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
8210 | .add = perf_swevent_add, |
8211 | .del = perf_swevent_del, | |
8212 | .start = perf_swevent_start, | |
8213 | .stop = perf_swevent_stop, | |
1c024eca | 8214 | .read = perf_swevent_read, |
1c024eca PZ |
8215 | }; |
8216 | ||
b0a873eb PZ |
8217 | #ifdef CONFIG_EVENT_TRACING |
8218 | ||
1c024eca PZ |
8219 | static int perf_tp_filter_match(struct perf_event *event, |
8220 | struct perf_sample_data *data) | |
8221 | { | |
7e3f977e | 8222 | void *record = data->raw->frag.data; |
1c024eca | 8223 | |
b71b437e PZ |
8224 | /* only top level events have filters set */ |
8225 | if (event->parent) | |
8226 | event = event->parent; | |
8227 | ||
1c024eca PZ |
8228 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
8229 | return 1; | |
8230 | return 0; | |
8231 | } | |
8232 | ||
8233 | static int perf_tp_event_match(struct perf_event *event, | |
8234 | struct perf_sample_data *data, | |
8235 | struct pt_regs *regs) | |
8236 | { | |
a0f7d0f7 FW |
8237 | if (event->hw.state & PERF_HES_STOPPED) |
8238 | return 0; | |
580d607c PZ |
8239 | /* |
8240 | * All tracepoints are from kernel-space. | |
8241 | */ | |
8242 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
8243 | return 0; |
8244 | ||
8245 | if (!perf_tp_filter_match(event, data)) | |
8246 | return 0; | |
8247 | ||
8248 | return 1; | |
8249 | } | |
8250 | ||
85b67bcb AS |
8251 | void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, |
8252 | struct trace_event_call *call, u64 count, | |
8253 | struct pt_regs *regs, struct hlist_head *head, | |
8254 | struct task_struct *task) | |
8255 | { | |
e87c6bc3 | 8256 | if (bpf_prog_array_valid(call)) { |
85b67bcb | 8257 | *(struct pt_regs **)raw_data = regs; |
e87c6bc3 | 8258 | if (!trace_call_bpf(call, raw_data) || hlist_empty(head)) { |
85b67bcb AS |
8259 | perf_swevent_put_recursion_context(rctx); |
8260 | return; | |
8261 | } | |
8262 | } | |
8263 | perf_tp_event(call->event.type, count, raw_data, size, regs, head, | |
8fd0fbbe | 8264 | rctx, task); |
85b67bcb AS |
8265 | } |
8266 | EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit); | |
8267 | ||
1e1dcd93 | 8268 | void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, |
e6dab5ff | 8269 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
8fd0fbbe | 8270 | struct task_struct *task) |
95476b64 FW |
8271 | { |
8272 | struct perf_sample_data data; | |
8fd0fbbe | 8273 | struct perf_event *event; |
1c024eca | 8274 | |
95476b64 | 8275 | struct perf_raw_record raw = { |
7e3f977e DB |
8276 | .frag = { |
8277 | .size = entry_size, | |
8278 | .data = record, | |
8279 | }, | |
95476b64 FW |
8280 | }; |
8281 | ||
1e1dcd93 | 8282 | perf_sample_data_init(&data, 0, 0); |
95476b64 FW |
8283 | data.raw = &raw; |
8284 | ||
1e1dcd93 AS |
8285 | perf_trace_buf_update(record, event_type); |
8286 | ||
8fd0fbbe | 8287 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 8288 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 8289 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 8290 | } |
ecc55f84 | 8291 | |
e6dab5ff AV |
8292 | /* |
8293 | * If we got specified a target task, also iterate its context and | |
8294 | * deliver this event there too. | |
8295 | */ | |
8296 | if (task && task != current) { | |
8297 | struct perf_event_context *ctx; | |
8298 | struct trace_entry *entry = record; | |
8299 | ||
8300 | rcu_read_lock(); | |
8301 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
8302 | if (!ctx) | |
8303 | goto unlock; | |
8304 | ||
8305 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
8306 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
8307 | continue; | |
8308 | if (event->attr.config != entry->type) | |
8309 | continue; | |
8310 | if (perf_tp_event_match(event, &data, regs)) | |
8311 | perf_swevent_event(event, count, &data, regs); | |
8312 | } | |
8313 | unlock: | |
8314 | rcu_read_unlock(); | |
8315 | } | |
8316 | ||
ecc55f84 | 8317 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
8318 | } |
8319 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
8320 | ||
cdd6c482 | 8321 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 8322 | { |
1c024eca | 8323 | perf_trace_destroy(event); |
e077df4f PZ |
8324 | } |
8325 | ||
b0a873eb | 8326 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 8327 | { |
76e1d904 FW |
8328 | int err; |
8329 | ||
b0a873eb PZ |
8330 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
8331 | return -ENOENT; | |
8332 | ||
2481c5fa SE |
8333 | /* |
8334 | * no branch sampling for tracepoint events | |
8335 | */ | |
8336 | if (has_branch_stack(event)) | |
8337 | return -EOPNOTSUPP; | |
8338 | ||
1c024eca PZ |
8339 | err = perf_trace_init(event); |
8340 | if (err) | |
b0a873eb | 8341 | return err; |
e077df4f | 8342 | |
cdd6c482 | 8343 | event->destroy = tp_perf_event_destroy; |
e077df4f | 8344 | |
b0a873eb PZ |
8345 | return 0; |
8346 | } | |
8347 | ||
8348 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
8349 | .task_ctx_nr = perf_sw_context, |
8350 | ||
b0a873eb | 8351 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
8352 | .add = perf_trace_add, |
8353 | .del = perf_trace_del, | |
8354 | .start = perf_swevent_start, | |
8355 | .stop = perf_swevent_stop, | |
b0a873eb | 8356 | .read = perf_swevent_read, |
b0a873eb PZ |
8357 | }; |
8358 | ||
33ea4b24 | 8359 | #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) |
e12f03d7 SL |
8360 | /* |
8361 | * Flags in config, used by dynamic PMU kprobe and uprobe | |
8362 | * The flags should match following PMU_FORMAT_ATTR(). | |
8363 | * | |
8364 | * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe | |
8365 | * if not set, create kprobe/uprobe | |
8366 | */ | |
8367 | enum perf_probe_config { | |
8368 | PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */ | |
8369 | }; | |
8370 | ||
8371 | PMU_FORMAT_ATTR(retprobe, "config:0"); | |
8372 | ||
8373 | static struct attribute *probe_attrs[] = { | |
8374 | &format_attr_retprobe.attr, | |
8375 | NULL, | |
8376 | }; | |
8377 | ||
8378 | static struct attribute_group probe_format_group = { | |
8379 | .name = "format", | |
8380 | .attrs = probe_attrs, | |
8381 | }; | |
8382 | ||
8383 | static const struct attribute_group *probe_attr_groups[] = { | |
8384 | &probe_format_group, | |
8385 | NULL, | |
8386 | }; | |
33ea4b24 | 8387 | #endif |
e12f03d7 | 8388 | |
33ea4b24 | 8389 | #ifdef CONFIG_KPROBE_EVENTS |
e12f03d7 SL |
8390 | static int perf_kprobe_event_init(struct perf_event *event); |
8391 | static struct pmu perf_kprobe = { | |
8392 | .task_ctx_nr = perf_sw_context, | |
8393 | .event_init = perf_kprobe_event_init, | |
8394 | .add = perf_trace_add, | |
8395 | .del = perf_trace_del, | |
8396 | .start = perf_swevent_start, | |
8397 | .stop = perf_swevent_stop, | |
8398 | .read = perf_swevent_read, | |
8399 | .attr_groups = probe_attr_groups, | |
8400 | }; | |
8401 | ||
8402 | static int perf_kprobe_event_init(struct perf_event *event) | |
8403 | { | |
8404 | int err; | |
8405 | bool is_retprobe; | |
8406 | ||
8407 | if (event->attr.type != perf_kprobe.type) | |
8408 | return -ENOENT; | |
32e6e967 SL |
8409 | |
8410 | if (!capable(CAP_SYS_ADMIN)) | |
8411 | return -EACCES; | |
8412 | ||
e12f03d7 SL |
8413 | /* |
8414 | * no branch sampling for probe events | |
8415 | */ | |
8416 | if (has_branch_stack(event)) | |
8417 | return -EOPNOTSUPP; | |
8418 | ||
8419 | is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; | |
8420 | err = perf_kprobe_init(event, is_retprobe); | |
8421 | if (err) | |
8422 | return err; | |
8423 | ||
8424 | event->destroy = perf_kprobe_destroy; | |
8425 | ||
8426 | return 0; | |
8427 | } | |
8428 | #endif /* CONFIG_KPROBE_EVENTS */ | |
8429 | ||
33ea4b24 SL |
8430 | #ifdef CONFIG_UPROBE_EVENTS |
8431 | static int perf_uprobe_event_init(struct perf_event *event); | |
8432 | static struct pmu perf_uprobe = { | |
8433 | .task_ctx_nr = perf_sw_context, | |
8434 | .event_init = perf_uprobe_event_init, | |
8435 | .add = perf_trace_add, | |
8436 | .del = perf_trace_del, | |
8437 | .start = perf_swevent_start, | |
8438 | .stop = perf_swevent_stop, | |
8439 | .read = perf_swevent_read, | |
8440 | .attr_groups = probe_attr_groups, | |
8441 | }; | |
8442 | ||
8443 | static int perf_uprobe_event_init(struct perf_event *event) | |
8444 | { | |
8445 | int err; | |
8446 | bool is_retprobe; | |
8447 | ||
8448 | if (event->attr.type != perf_uprobe.type) | |
8449 | return -ENOENT; | |
32e6e967 SL |
8450 | |
8451 | if (!capable(CAP_SYS_ADMIN)) | |
8452 | return -EACCES; | |
8453 | ||
33ea4b24 SL |
8454 | /* |
8455 | * no branch sampling for probe events | |
8456 | */ | |
8457 | if (has_branch_stack(event)) | |
8458 | return -EOPNOTSUPP; | |
8459 | ||
8460 | is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; | |
8461 | err = perf_uprobe_init(event, is_retprobe); | |
8462 | if (err) | |
8463 | return err; | |
8464 | ||
8465 | event->destroy = perf_uprobe_destroy; | |
8466 | ||
8467 | return 0; | |
8468 | } | |
8469 | #endif /* CONFIG_UPROBE_EVENTS */ | |
8470 | ||
b0a873eb PZ |
8471 | static inline void perf_tp_register(void) |
8472 | { | |
2e80a82a | 8473 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e12f03d7 SL |
8474 | #ifdef CONFIG_KPROBE_EVENTS |
8475 | perf_pmu_register(&perf_kprobe, "kprobe", -1); | |
8476 | #endif | |
33ea4b24 SL |
8477 | #ifdef CONFIG_UPROBE_EVENTS |
8478 | perf_pmu_register(&perf_uprobe, "uprobe", -1); | |
8479 | #endif | |
e077df4f | 8480 | } |
6fb2915d | 8481 | |
6fb2915d LZ |
8482 | static void perf_event_free_filter(struct perf_event *event) |
8483 | { | |
8484 | ftrace_profile_free_filter(event); | |
8485 | } | |
8486 | ||
aa6a5f3c AS |
8487 | #ifdef CONFIG_BPF_SYSCALL |
8488 | static void bpf_overflow_handler(struct perf_event *event, | |
8489 | struct perf_sample_data *data, | |
8490 | struct pt_regs *regs) | |
8491 | { | |
8492 | struct bpf_perf_event_data_kern ctx = { | |
8493 | .data = data, | |
7d9285e8 | 8494 | .event = event, |
aa6a5f3c AS |
8495 | }; |
8496 | int ret = 0; | |
8497 | ||
c895f6f7 | 8498 | ctx.regs = perf_arch_bpf_user_pt_regs(regs); |
aa6a5f3c AS |
8499 | preempt_disable(); |
8500 | if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) | |
8501 | goto out; | |
8502 | rcu_read_lock(); | |
88575199 | 8503 | ret = BPF_PROG_RUN(event->prog, &ctx); |
aa6a5f3c AS |
8504 | rcu_read_unlock(); |
8505 | out: | |
8506 | __this_cpu_dec(bpf_prog_active); | |
8507 | preempt_enable(); | |
8508 | if (!ret) | |
8509 | return; | |
8510 | ||
8511 | event->orig_overflow_handler(event, data, regs); | |
8512 | } | |
8513 | ||
8514 | static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) | |
8515 | { | |
8516 | struct bpf_prog *prog; | |
8517 | ||
8518 | if (event->overflow_handler_context) | |
8519 | /* hw breakpoint or kernel counter */ | |
8520 | return -EINVAL; | |
8521 | ||
8522 | if (event->prog) | |
8523 | return -EEXIST; | |
8524 | ||
8525 | prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); | |
8526 | if (IS_ERR(prog)) | |
8527 | return PTR_ERR(prog); | |
8528 | ||
8529 | event->prog = prog; | |
8530 | event->orig_overflow_handler = READ_ONCE(event->overflow_handler); | |
8531 | WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); | |
8532 | return 0; | |
8533 | } | |
8534 | ||
8535 | static void perf_event_free_bpf_handler(struct perf_event *event) | |
8536 | { | |
8537 | struct bpf_prog *prog = event->prog; | |
8538 | ||
8539 | if (!prog) | |
8540 | return; | |
8541 | ||
8542 | WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler); | |
8543 | event->prog = NULL; | |
8544 | bpf_prog_put(prog); | |
8545 | } | |
8546 | #else | |
8547 | static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) | |
8548 | { | |
8549 | return -EOPNOTSUPP; | |
8550 | } | |
8551 | static void perf_event_free_bpf_handler(struct perf_event *event) | |
8552 | { | |
8553 | } | |
8554 | #endif | |
8555 | ||
e12f03d7 SL |
8556 | /* |
8557 | * returns true if the event is a tracepoint, or a kprobe/upprobe created | |
8558 | * with perf_event_open() | |
8559 | */ | |
8560 | static inline bool perf_event_is_tracing(struct perf_event *event) | |
8561 | { | |
8562 | if (event->pmu == &perf_tracepoint) | |
8563 | return true; | |
8564 | #ifdef CONFIG_KPROBE_EVENTS | |
8565 | if (event->pmu == &perf_kprobe) | |
8566 | return true; | |
33ea4b24 SL |
8567 | #endif |
8568 | #ifdef CONFIG_UPROBE_EVENTS | |
8569 | if (event->pmu == &perf_uprobe) | |
8570 | return true; | |
e12f03d7 SL |
8571 | #endif |
8572 | return false; | |
8573 | } | |
8574 | ||
2541517c AS |
8575 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
8576 | { | |
cf5f5cea | 8577 | bool is_kprobe, is_tracepoint, is_syscall_tp; |
2541517c | 8578 | struct bpf_prog *prog; |
e87c6bc3 | 8579 | int ret; |
2541517c | 8580 | |
e12f03d7 | 8581 | if (!perf_event_is_tracing(event)) |
f91840a3 | 8582 | return perf_event_set_bpf_handler(event, prog_fd); |
2541517c | 8583 | |
98b5c2c6 AS |
8584 | is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; |
8585 | is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; | |
cf5f5cea YS |
8586 | is_syscall_tp = is_syscall_trace_event(event->tp_event); |
8587 | if (!is_kprobe && !is_tracepoint && !is_syscall_tp) | |
98b5c2c6 | 8588 | /* bpf programs can only be attached to u/kprobe or tracepoint */ |
2541517c AS |
8589 | return -EINVAL; |
8590 | ||
8591 | prog = bpf_prog_get(prog_fd); | |
8592 | if (IS_ERR(prog)) | |
8593 | return PTR_ERR(prog); | |
8594 | ||
98b5c2c6 | 8595 | if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || |
cf5f5cea YS |
8596 | (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || |
8597 | (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) { | |
2541517c AS |
8598 | /* valid fd, but invalid bpf program type */ |
8599 | bpf_prog_put(prog); | |
8600 | return -EINVAL; | |
8601 | } | |
8602 | ||
9802d865 JB |
8603 | /* Kprobe override only works for kprobes, not uprobes. */ |
8604 | if (prog->kprobe_override && | |
8605 | !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) { | |
8606 | bpf_prog_put(prog); | |
8607 | return -EINVAL; | |
8608 | } | |
8609 | ||
cf5f5cea | 8610 | if (is_tracepoint || is_syscall_tp) { |
32bbe007 AS |
8611 | int off = trace_event_get_offsets(event->tp_event); |
8612 | ||
8613 | if (prog->aux->max_ctx_offset > off) { | |
8614 | bpf_prog_put(prog); | |
8615 | return -EACCES; | |
8616 | } | |
8617 | } | |
2541517c | 8618 | |
e87c6bc3 YS |
8619 | ret = perf_event_attach_bpf_prog(event, prog); |
8620 | if (ret) | |
8621 | bpf_prog_put(prog); | |
8622 | return ret; | |
2541517c AS |
8623 | } |
8624 | ||
8625 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
8626 | { | |
e12f03d7 | 8627 | if (!perf_event_is_tracing(event)) { |
0b4c6841 | 8628 | perf_event_free_bpf_handler(event); |
2541517c | 8629 | return; |
2541517c | 8630 | } |
e87c6bc3 | 8631 | perf_event_detach_bpf_prog(event); |
2541517c AS |
8632 | } |
8633 | ||
e077df4f | 8634 | #else |
6fb2915d | 8635 | |
b0a873eb | 8636 | static inline void perf_tp_register(void) |
e077df4f | 8637 | { |
e077df4f | 8638 | } |
6fb2915d | 8639 | |
6fb2915d LZ |
8640 | static void perf_event_free_filter(struct perf_event *event) |
8641 | { | |
8642 | } | |
8643 | ||
2541517c AS |
8644 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
8645 | { | |
8646 | return -ENOENT; | |
8647 | } | |
8648 | ||
8649 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
8650 | { | |
8651 | } | |
07b139c8 | 8652 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 8653 | |
24f1e32c | 8654 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 8655 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 8656 | { |
f5ffe02e FW |
8657 | struct perf_sample_data sample; |
8658 | struct pt_regs *regs = data; | |
8659 | ||
fd0d000b | 8660 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 8661 | |
a4eaf7f1 | 8662 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 8663 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
8664 | } |
8665 | #endif | |
8666 | ||
375637bc AS |
8667 | /* |
8668 | * Allocate a new address filter | |
8669 | */ | |
8670 | static struct perf_addr_filter * | |
8671 | perf_addr_filter_new(struct perf_event *event, struct list_head *filters) | |
8672 | { | |
8673 | int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu); | |
8674 | struct perf_addr_filter *filter; | |
8675 | ||
8676 | filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node); | |
8677 | if (!filter) | |
8678 | return NULL; | |
8679 | ||
8680 | INIT_LIST_HEAD(&filter->entry); | |
8681 | list_add_tail(&filter->entry, filters); | |
8682 | ||
8683 | return filter; | |
8684 | } | |
8685 | ||
8686 | static void free_filters_list(struct list_head *filters) | |
8687 | { | |
8688 | struct perf_addr_filter *filter, *iter; | |
8689 | ||
8690 | list_for_each_entry_safe(filter, iter, filters, entry) { | |
9511bce9 | 8691 | path_put(&filter->path); |
375637bc AS |
8692 | list_del(&filter->entry); |
8693 | kfree(filter); | |
8694 | } | |
8695 | } | |
8696 | ||
8697 | /* | |
8698 | * Free existing address filters and optionally install new ones | |
8699 | */ | |
8700 | static void perf_addr_filters_splice(struct perf_event *event, | |
8701 | struct list_head *head) | |
8702 | { | |
8703 | unsigned long flags; | |
8704 | LIST_HEAD(list); | |
8705 | ||
8706 | if (!has_addr_filter(event)) | |
8707 | return; | |
8708 | ||
8709 | /* don't bother with children, they don't have their own filters */ | |
8710 | if (event->parent) | |
8711 | return; | |
8712 | ||
8713 | raw_spin_lock_irqsave(&event->addr_filters.lock, flags); | |
8714 | ||
8715 | list_splice_init(&event->addr_filters.list, &list); | |
8716 | if (head) | |
8717 | list_splice(head, &event->addr_filters.list); | |
8718 | ||
8719 | raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags); | |
8720 | ||
8721 | free_filters_list(&list); | |
8722 | } | |
8723 | ||
8724 | /* | |
8725 | * Scan through mm's vmas and see if one of them matches the | |
8726 | * @filter; if so, adjust filter's address range. | |
8727 | * Called with mm::mmap_sem down for reading. | |
8728 | */ | |
8729 | static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter, | |
8730 | struct mm_struct *mm) | |
8731 | { | |
8732 | struct vm_area_struct *vma; | |
8733 | ||
8734 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
8735 | struct file *file = vma->vm_file; | |
8736 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT; | |
8737 | unsigned long vma_size = vma->vm_end - vma->vm_start; | |
8738 | ||
8739 | if (!file) | |
8740 | continue; | |
8741 | ||
8742 | if (!perf_addr_filter_match(filter, file, off, vma_size)) | |
8743 | continue; | |
8744 | ||
8745 | return vma->vm_start; | |
8746 | } | |
8747 | ||
8748 | return 0; | |
8749 | } | |
8750 | ||
8751 | /* | |
8752 | * Update event's address range filters based on the | |
8753 | * task's existing mappings, if any. | |
8754 | */ | |
8755 | static void perf_event_addr_filters_apply(struct perf_event *event) | |
8756 | { | |
8757 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
8758 | struct task_struct *task = READ_ONCE(event->ctx->task); | |
8759 | struct perf_addr_filter *filter; | |
8760 | struct mm_struct *mm = NULL; | |
8761 | unsigned int count = 0; | |
8762 | unsigned long flags; | |
8763 | ||
8764 | /* | |
8765 | * We may observe TASK_TOMBSTONE, which means that the event tear-down | |
8766 | * will stop on the parent's child_mutex that our caller is also holding | |
8767 | */ | |
8768 | if (task == TASK_TOMBSTONE) | |
8769 | return; | |
8770 | ||
6ce77bfd AS |
8771 | if (!ifh->nr_file_filters) |
8772 | return; | |
8773 | ||
375637bc AS |
8774 | mm = get_task_mm(event->ctx->task); |
8775 | if (!mm) | |
8776 | goto restart; | |
8777 | ||
8778 | down_read(&mm->mmap_sem); | |
8779 | ||
8780 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
8781 | list_for_each_entry(filter, &ifh->list, entry) { | |
8782 | event->addr_filters_offs[count] = 0; | |
8783 | ||
99f5bc9b MP |
8784 | /* |
8785 | * Adjust base offset if the filter is associated to a binary | |
8786 | * that needs to be mapped: | |
8787 | */ | |
9511bce9 | 8788 | if (filter->path.dentry) |
375637bc AS |
8789 | event->addr_filters_offs[count] = |
8790 | perf_addr_filter_apply(filter, mm); | |
8791 | ||
8792 | count++; | |
8793 | } | |
8794 | ||
8795 | event->addr_filters_gen++; | |
8796 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
8797 | ||
8798 | up_read(&mm->mmap_sem); | |
8799 | ||
8800 | mmput(mm); | |
8801 | ||
8802 | restart: | |
767ae086 | 8803 | perf_event_stop(event, 1); |
375637bc AS |
8804 | } |
8805 | ||
8806 | /* | |
8807 | * Address range filtering: limiting the data to certain | |
8808 | * instruction address ranges. Filters are ioctl()ed to us from | |
8809 | * userspace as ascii strings. | |
8810 | * | |
8811 | * Filter string format: | |
8812 | * | |
8813 | * ACTION RANGE_SPEC | |
8814 | * where ACTION is one of the | |
8815 | * * "filter": limit the trace to this region | |
8816 | * * "start": start tracing from this address | |
8817 | * * "stop": stop tracing at this address/region; | |
8818 | * RANGE_SPEC is | |
8819 | * * for kernel addresses: <start address>[/<size>] | |
8820 | * * for object files: <start address>[/<size>]@</path/to/object/file> | |
8821 | * | |
6ed70cf3 AS |
8822 | * if <size> is not specified or is zero, the range is treated as a single |
8823 | * address; not valid for ACTION=="filter". | |
375637bc AS |
8824 | */ |
8825 | enum { | |
e96271f3 | 8826 | IF_ACT_NONE = -1, |
375637bc AS |
8827 | IF_ACT_FILTER, |
8828 | IF_ACT_START, | |
8829 | IF_ACT_STOP, | |
8830 | IF_SRC_FILE, | |
8831 | IF_SRC_KERNEL, | |
8832 | IF_SRC_FILEADDR, | |
8833 | IF_SRC_KERNELADDR, | |
8834 | }; | |
8835 | ||
8836 | enum { | |
8837 | IF_STATE_ACTION = 0, | |
8838 | IF_STATE_SOURCE, | |
8839 | IF_STATE_END, | |
8840 | }; | |
8841 | ||
8842 | static const match_table_t if_tokens = { | |
8843 | { IF_ACT_FILTER, "filter" }, | |
8844 | { IF_ACT_START, "start" }, | |
8845 | { IF_ACT_STOP, "stop" }, | |
8846 | { IF_SRC_FILE, "%u/%u@%s" }, | |
8847 | { IF_SRC_KERNEL, "%u/%u" }, | |
8848 | { IF_SRC_FILEADDR, "%u@%s" }, | |
8849 | { IF_SRC_KERNELADDR, "%u" }, | |
e96271f3 | 8850 | { IF_ACT_NONE, NULL }, |
375637bc AS |
8851 | }; |
8852 | ||
8853 | /* | |
8854 | * Address filter string parser | |
8855 | */ | |
8856 | static int | |
8857 | perf_event_parse_addr_filter(struct perf_event *event, char *fstr, | |
8858 | struct list_head *filters) | |
8859 | { | |
8860 | struct perf_addr_filter *filter = NULL; | |
8861 | char *start, *orig, *filename = NULL; | |
375637bc AS |
8862 | substring_t args[MAX_OPT_ARGS]; |
8863 | int state = IF_STATE_ACTION, token; | |
8864 | unsigned int kernel = 0; | |
8865 | int ret = -EINVAL; | |
8866 | ||
8867 | orig = fstr = kstrdup(fstr, GFP_KERNEL); | |
8868 | if (!fstr) | |
8869 | return -ENOMEM; | |
8870 | ||
8871 | while ((start = strsep(&fstr, " ,\n")) != NULL) { | |
6ed70cf3 AS |
8872 | static const enum perf_addr_filter_action_t actions[] = { |
8873 | [IF_ACT_FILTER] = PERF_ADDR_FILTER_ACTION_FILTER, | |
8874 | [IF_ACT_START] = PERF_ADDR_FILTER_ACTION_START, | |
8875 | [IF_ACT_STOP] = PERF_ADDR_FILTER_ACTION_STOP, | |
8876 | }; | |
375637bc AS |
8877 | ret = -EINVAL; |
8878 | ||
8879 | if (!*start) | |
8880 | continue; | |
8881 | ||
8882 | /* filter definition begins */ | |
8883 | if (state == IF_STATE_ACTION) { | |
8884 | filter = perf_addr_filter_new(event, filters); | |
8885 | if (!filter) | |
8886 | goto fail; | |
8887 | } | |
8888 | ||
8889 | token = match_token(start, if_tokens, args); | |
8890 | switch (token) { | |
8891 | case IF_ACT_FILTER: | |
8892 | case IF_ACT_START: | |
375637bc AS |
8893 | case IF_ACT_STOP: |
8894 | if (state != IF_STATE_ACTION) | |
8895 | goto fail; | |
8896 | ||
6ed70cf3 | 8897 | filter->action = actions[token]; |
375637bc AS |
8898 | state = IF_STATE_SOURCE; |
8899 | break; | |
8900 | ||
8901 | case IF_SRC_KERNELADDR: | |
8902 | case IF_SRC_KERNEL: | |
8903 | kernel = 1; | |
8904 | ||
8905 | case IF_SRC_FILEADDR: | |
8906 | case IF_SRC_FILE: | |
8907 | if (state != IF_STATE_SOURCE) | |
8908 | goto fail; | |
8909 | ||
375637bc AS |
8910 | *args[0].to = 0; |
8911 | ret = kstrtoul(args[0].from, 0, &filter->offset); | |
8912 | if (ret) | |
8913 | goto fail; | |
8914 | ||
6ed70cf3 | 8915 | if (token == IF_SRC_KERNEL || token == IF_SRC_FILE) { |
375637bc AS |
8916 | *args[1].to = 0; |
8917 | ret = kstrtoul(args[1].from, 0, &filter->size); | |
8918 | if (ret) | |
8919 | goto fail; | |
8920 | } | |
8921 | ||
4059ffd0 | 8922 | if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) { |
6ed70cf3 | 8923 | int fpos = token == IF_SRC_FILE ? 2 : 1; |
4059ffd0 MP |
8924 | |
8925 | filename = match_strdup(&args[fpos]); | |
375637bc AS |
8926 | if (!filename) { |
8927 | ret = -ENOMEM; | |
8928 | goto fail; | |
8929 | } | |
8930 | } | |
8931 | ||
8932 | state = IF_STATE_END; | |
8933 | break; | |
8934 | ||
8935 | default: | |
8936 | goto fail; | |
8937 | } | |
8938 | ||
8939 | /* | |
8940 | * Filter definition is fully parsed, validate and install it. | |
8941 | * Make sure that it doesn't contradict itself or the event's | |
8942 | * attribute. | |
8943 | */ | |
8944 | if (state == IF_STATE_END) { | |
9ccbfbb1 | 8945 | ret = -EINVAL; |
375637bc AS |
8946 | if (kernel && event->attr.exclude_kernel) |
8947 | goto fail; | |
8948 | ||
6ed70cf3 AS |
8949 | /* |
8950 | * ACTION "filter" must have a non-zero length region | |
8951 | * specified. | |
8952 | */ | |
8953 | if (filter->action == PERF_ADDR_FILTER_ACTION_FILTER && | |
8954 | !filter->size) | |
8955 | goto fail; | |
8956 | ||
375637bc AS |
8957 | if (!kernel) { |
8958 | if (!filename) | |
8959 | goto fail; | |
8960 | ||
6ce77bfd AS |
8961 | /* |
8962 | * For now, we only support file-based filters | |
8963 | * in per-task events; doing so for CPU-wide | |
8964 | * events requires additional context switching | |
8965 | * trickery, since same object code will be | |
8966 | * mapped at different virtual addresses in | |
8967 | * different processes. | |
8968 | */ | |
8969 | ret = -EOPNOTSUPP; | |
8970 | if (!event->ctx->task) | |
8971 | goto fail_free_name; | |
8972 | ||
375637bc | 8973 | /* look up the path and grab its inode */ |
9511bce9 SL |
8974 | ret = kern_path(filename, LOOKUP_FOLLOW, |
8975 | &filter->path); | |
375637bc AS |
8976 | if (ret) |
8977 | goto fail_free_name; | |
8978 | ||
375637bc AS |
8979 | kfree(filename); |
8980 | filename = NULL; | |
8981 | ||
8982 | ret = -EINVAL; | |
9511bce9 SL |
8983 | if (!filter->path.dentry || |
8984 | !S_ISREG(d_inode(filter->path.dentry) | |
8985 | ->i_mode)) | |
375637bc | 8986 | goto fail; |
6ce77bfd AS |
8987 | |
8988 | event->addr_filters.nr_file_filters++; | |
375637bc AS |
8989 | } |
8990 | ||
8991 | /* ready to consume more filters */ | |
8992 | state = IF_STATE_ACTION; | |
8993 | filter = NULL; | |
8994 | } | |
8995 | } | |
8996 | ||
8997 | if (state != IF_STATE_ACTION) | |
8998 | goto fail; | |
8999 | ||
9000 | kfree(orig); | |
9001 | ||
9002 | return 0; | |
9003 | ||
9004 | fail_free_name: | |
9005 | kfree(filename); | |
9006 | fail: | |
9007 | free_filters_list(filters); | |
9008 | kfree(orig); | |
9009 | ||
9010 | return ret; | |
9011 | } | |
9012 | ||
9013 | static int | |
9014 | perf_event_set_addr_filter(struct perf_event *event, char *filter_str) | |
9015 | { | |
9016 | LIST_HEAD(filters); | |
9017 | int ret; | |
9018 | ||
9019 | /* | |
9020 | * Since this is called in perf_ioctl() path, we're already holding | |
9021 | * ctx::mutex. | |
9022 | */ | |
9023 | lockdep_assert_held(&event->ctx->mutex); | |
9024 | ||
9025 | if (WARN_ON_ONCE(event->parent)) | |
9026 | return -EINVAL; | |
9027 | ||
375637bc AS |
9028 | ret = perf_event_parse_addr_filter(event, filter_str, &filters); |
9029 | if (ret) | |
6ce77bfd | 9030 | goto fail_clear_files; |
375637bc AS |
9031 | |
9032 | ret = event->pmu->addr_filters_validate(&filters); | |
6ce77bfd AS |
9033 | if (ret) |
9034 | goto fail_free_filters; | |
375637bc AS |
9035 | |
9036 | /* remove existing filters, if any */ | |
9037 | perf_addr_filters_splice(event, &filters); | |
9038 | ||
9039 | /* install new filters */ | |
9040 | perf_event_for_each_child(event, perf_event_addr_filters_apply); | |
9041 | ||
6ce77bfd AS |
9042 | return ret; |
9043 | ||
9044 | fail_free_filters: | |
9045 | free_filters_list(&filters); | |
9046 | ||
9047 | fail_clear_files: | |
9048 | event->addr_filters.nr_file_filters = 0; | |
9049 | ||
375637bc AS |
9050 | return ret; |
9051 | } | |
9052 | ||
c796bbbe AS |
9053 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) |
9054 | { | |
c796bbbe | 9055 | int ret = -EINVAL; |
e12f03d7 | 9056 | char *filter_str; |
c796bbbe AS |
9057 | |
9058 | filter_str = strndup_user(arg, PAGE_SIZE); | |
9059 | if (IS_ERR(filter_str)) | |
9060 | return PTR_ERR(filter_str); | |
9061 | ||
e12f03d7 SL |
9062 | #ifdef CONFIG_EVENT_TRACING |
9063 | if (perf_event_is_tracing(event)) { | |
9064 | struct perf_event_context *ctx = event->ctx; | |
9065 | ||
9066 | /* | |
9067 | * Beware, here be dragons!! | |
9068 | * | |
9069 | * the tracepoint muck will deadlock against ctx->mutex, but | |
9070 | * the tracepoint stuff does not actually need it. So | |
9071 | * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we | |
9072 | * already have a reference on ctx. | |
9073 | * | |
9074 | * This can result in event getting moved to a different ctx, | |
9075 | * but that does not affect the tracepoint state. | |
9076 | */ | |
9077 | mutex_unlock(&ctx->mutex); | |
9078 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
9079 | mutex_lock(&ctx->mutex); | |
9080 | } else | |
9081 | #endif | |
9082 | if (has_addr_filter(event)) | |
375637bc | 9083 | ret = perf_event_set_addr_filter(event, filter_str); |
c796bbbe AS |
9084 | |
9085 | kfree(filter_str); | |
9086 | return ret; | |
9087 | } | |
9088 | ||
b0a873eb PZ |
9089 | /* |
9090 | * hrtimer based swevent callback | |
9091 | */ | |
f29ac756 | 9092 | |
b0a873eb | 9093 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 9094 | { |
b0a873eb PZ |
9095 | enum hrtimer_restart ret = HRTIMER_RESTART; |
9096 | struct perf_sample_data data; | |
9097 | struct pt_regs *regs; | |
9098 | struct perf_event *event; | |
9099 | u64 period; | |
f29ac756 | 9100 | |
b0a873eb | 9101 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
9102 | |
9103 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
9104 | return HRTIMER_NORESTART; | |
9105 | ||
b0a873eb | 9106 | event->pmu->read(event); |
f344011c | 9107 | |
fd0d000b | 9108 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
9109 | regs = get_irq_regs(); |
9110 | ||
9111 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 9112 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 9113 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
9114 | ret = HRTIMER_NORESTART; |
9115 | } | |
24f1e32c | 9116 | |
b0a873eb PZ |
9117 | period = max_t(u64, 10000, event->hw.sample_period); |
9118 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 9119 | |
b0a873eb | 9120 | return ret; |
f29ac756 PZ |
9121 | } |
9122 | ||
b0a873eb | 9123 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 9124 | { |
b0a873eb | 9125 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
9126 | s64 period; |
9127 | ||
9128 | if (!is_sampling_event(event)) | |
9129 | return; | |
f5ffe02e | 9130 | |
5d508e82 FBH |
9131 | period = local64_read(&hwc->period_left); |
9132 | if (period) { | |
9133 | if (period < 0) | |
9134 | period = 10000; | |
fa407f35 | 9135 | |
5d508e82 FBH |
9136 | local64_set(&hwc->period_left, 0); |
9137 | } else { | |
9138 | period = max_t(u64, 10000, hwc->sample_period); | |
9139 | } | |
3497d206 TG |
9140 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
9141 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 9142 | } |
b0a873eb PZ |
9143 | |
9144 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 9145 | { |
b0a873eb PZ |
9146 | struct hw_perf_event *hwc = &event->hw; |
9147 | ||
6c7e550f | 9148 | if (is_sampling_event(event)) { |
b0a873eb | 9149 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 9150 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
9151 | |
9152 | hrtimer_cancel(&hwc->hrtimer); | |
9153 | } | |
24f1e32c FW |
9154 | } |
9155 | ||
ba3dd36c PZ |
9156 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
9157 | { | |
9158 | struct hw_perf_event *hwc = &event->hw; | |
9159 | ||
9160 | if (!is_sampling_event(event)) | |
9161 | return; | |
9162 | ||
9163 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
9164 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
9165 | ||
9166 | /* | |
9167 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
9168 | * mapping and avoid the whole period adjust feedback stuff. | |
9169 | */ | |
9170 | if (event->attr.freq) { | |
9171 | long freq = event->attr.sample_freq; | |
9172 | ||
9173 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
9174 | hwc->sample_period = event->attr.sample_period; | |
9175 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 9176 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
9177 | event->attr.freq = 0; |
9178 | } | |
9179 | } | |
9180 | ||
b0a873eb PZ |
9181 | /* |
9182 | * Software event: cpu wall time clock | |
9183 | */ | |
9184 | ||
9185 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 9186 | { |
b0a873eb PZ |
9187 | s64 prev; |
9188 | u64 now; | |
9189 | ||
a4eaf7f1 | 9190 | now = local_clock(); |
b0a873eb PZ |
9191 | prev = local64_xchg(&event->hw.prev_count, now); |
9192 | local64_add(now - prev, &event->count); | |
24f1e32c | 9193 | } |
24f1e32c | 9194 | |
a4eaf7f1 | 9195 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 9196 | { |
a4eaf7f1 | 9197 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 9198 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
9199 | } |
9200 | ||
a4eaf7f1 | 9201 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 9202 | { |
b0a873eb PZ |
9203 | perf_swevent_cancel_hrtimer(event); |
9204 | cpu_clock_event_update(event); | |
9205 | } | |
f29ac756 | 9206 | |
a4eaf7f1 PZ |
9207 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
9208 | { | |
9209 | if (flags & PERF_EF_START) | |
9210 | cpu_clock_event_start(event, flags); | |
6a694a60 | 9211 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
9212 | |
9213 | return 0; | |
9214 | } | |
9215 | ||
9216 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
9217 | { | |
9218 | cpu_clock_event_stop(event, flags); | |
9219 | } | |
9220 | ||
b0a873eb PZ |
9221 | static void cpu_clock_event_read(struct perf_event *event) |
9222 | { | |
9223 | cpu_clock_event_update(event); | |
9224 | } | |
f344011c | 9225 | |
b0a873eb PZ |
9226 | static int cpu_clock_event_init(struct perf_event *event) |
9227 | { | |
9228 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
9229 | return -ENOENT; | |
9230 | ||
9231 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
9232 | return -ENOENT; | |
9233 | ||
2481c5fa SE |
9234 | /* |
9235 | * no branch sampling for software events | |
9236 | */ | |
9237 | if (has_branch_stack(event)) | |
9238 | return -EOPNOTSUPP; | |
9239 | ||
ba3dd36c PZ |
9240 | perf_swevent_init_hrtimer(event); |
9241 | ||
b0a873eb | 9242 | return 0; |
f29ac756 PZ |
9243 | } |
9244 | ||
b0a873eb | 9245 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
9246 | .task_ctx_nr = perf_sw_context, |
9247 | ||
34f43927 PZ |
9248 | .capabilities = PERF_PMU_CAP_NO_NMI, |
9249 | ||
b0a873eb | 9250 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
9251 | .add = cpu_clock_event_add, |
9252 | .del = cpu_clock_event_del, | |
9253 | .start = cpu_clock_event_start, | |
9254 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
9255 | .read = cpu_clock_event_read, |
9256 | }; | |
9257 | ||
9258 | /* | |
9259 | * Software event: task time clock | |
9260 | */ | |
9261 | ||
9262 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 9263 | { |
b0a873eb PZ |
9264 | u64 prev; |
9265 | s64 delta; | |
5c92d124 | 9266 | |
b0a873eb PZ |
9267 | prev = local64_xchg(&event->hw.prev_count, now); |
9268 | delta = now - prev; | |
9269 | local64_add(delta, &event->count); | |
9270 | } | |
5c92d124 | 9271 | |
a4eaf7f1 | 9272 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 9273 | { |
a4eaf7f1 | 9274 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 9275 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
9276 | } |
9277 | ||
a4eaf7f1 | 9278 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
9279 | { |
9280 | perf_swevent_cancel_hrtimer(event); | |
9281 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
9282 | } |
9283 | ||
9284 | static int task_clock_event_add(struct perf_event *event, int flags) | |
9285 | { | |
9286 | if (flags & PERF_EF_START) | |
9287 | task_clock_event_start(event, flags); | |
6a694a60 | 9288 | perf_event_update_userpage(event); |
b0a873eb | 9289 | |
a4eaf7f1 PZ |
9290 | return 0; |
9291 | } | |
9292 | ||
9293 | static void task_clock_event_del(struct perf_event *event, int flags) | |
9294 | { | |
9295 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
9296 | } |
9297 | ||
9298 | static void task_clock_event_read(struct perf_event *event) | |
9299 | { | |
768a06e2 PZ |
9300 | u64 now = perf_clock(); |
9301 | u64 delta = now - event->ctx->timestamp; | |
9302 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
9303 | |
9304 | task_clock_event_update(event, time); | |
9305 | } | |
9306 | ||
9307 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 9308 | { |
b0a873eb PZ |
9309 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
9310 | return -ENOENT; | |
9311 | ||
9312 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
9313 | return -ENOENT; | |
9314 | ||
2481c5fa SE |
9315 | /* |
9316 | * no branch sampling for software events | |
9317 | */ | |
9318 | if (has_branch_stack(event)) | |
9319 | return -EOPNOTSUPP; | |
9320 | ||
ba3dd36c PZ |
9321 | perf_swevent_init_hrtimer(event); |
9322 | ||
b0a873eb | 9323 | return 0; |
6fb2915d LZ |
9324 | } |
9325 | ||
b0a873eb | 9326 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
9327 | .task_ctx_nr = perf_sw_context, |
9328 | ||
34f43927 PZ |
9329 | .capabilities = PERF_PMU_CAP_NO_NMI, |
9330 | ||
b0a873eb | 9331 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
9332 | .add = task_clock_event_add, |
9333 | .del = task_clock_event_del, | |
9334 | .start = task_clock_event_start, | |
9335 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
9336 | .read = task_clock_event_read, |
9337 | }; | |
6fb2915d | 9338 | |
ad5133b7 | 9339 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 9340 | { |
e077df4f | 9341 | } |
6fb2915d | 9342 | |
fbbe0701 SB |
9343 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
9344 | { | |
9345 | } | |
9346 | ||
ad5133b7 | 9347 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 9348 | { |
ad5133b7 | 9349 | return 0; |
6fb2915d LZ |
9350 | } |
9351 | ||
18ab2cd3 | 9352 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
9353 | |
9354 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 9355 | { |
fbbe0701 SB |
9356 | __this_cpu_write(nop_txn_flags, flags); |
9357 | ||
9358 | if (flags & ~PERF_PMU_TXN_ADD) | |
9359 | return; | |
9360 | ||
ad5133b7 | 9361 | perf_pmu_disable(pmu); |
6fb2915d LZ |
9362 | } |
9363 | ||
ad5133b7 PZ |
9364 | static int perf_pmu_commit_txn(struct pmu *pmu) |
9365 | { | |
fbbe0701 SB |
9366 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
9367 | ||
9368 | __this_cpu_write(nop_txn_flags, 0); | |
9369 | ||
9370 | if (flags & ~PERF_PMU_TXN_ADD) | |
9371 | return 0; | |
9372 | ||
ad5133b7 PZ |
9373 | perf_pmu_enable(pmu); |
9374 | return 0; | |
9375 | } | |
e077df4f | 9376 | |
ad5133b7 | 9377 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 9378 | { |
fbbe0701 SB |
9379 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
9380 | ||
9381 | __this_cpu_write(nop_txn_flags, 0); | |
9382 | ||
9383 | if (flags & ~PERF_PMU_TXN_ADD) | |
9384 | return; | |
9385 | ||
ad5133b7 | 9386 | perf_pmu_enable(pmu); |
24f1e32c FW |
9387 | } |
9388 | ||
35edc2a5 PZ |
9389 | static int perf_event_idx_default(struct perf_event *event) |
9390 | { | |
c719f560 | 9391 | return 0; |
35edc2a5 PZ |
9392 | } |
9393 | ||
8dc85d54 PZ |
9394 | /* |
9395 | * Ensures all contexts with the same task_ctx_nr have the same | |
9396 | * pmu_cpu_context too. | |
9397 | */ | |
9e317041 | 9398 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 9399 | { |
8dc85d54 | 9400 | struct pmu *pmu; |
b326e956 | 9401 | |
8dc85d54 PZ |
9402 | if (ctxn < 0) |
9403 | return NULL; | |
24f1e32c | 9404 | |
8dc85d54 PZ |
9405 | list_for_each_entry(pmu, &pmus, entry) { |
9406 | if (pmu->task_ctx_nr == ctxn) | |
9407 | return pmu->pmu_cpu_context; | |
9408 | } | |
24f1e32c | 9409 | |
8dc85d54 | 9410 | return NULL; |
24f1e32c FW |
9411 | } |
9412 | ||
51676957 PZ |
9413 | static void free_pmu_context(struct pmu *pmu) |
9414 | { | |
df0062b2 WD |
9415 | /* |
9416 | * Static contexts such as perf_sw_context have a global lifetime | |
9417 | * and may be shared between different PMUs. Avoid freeing them | |
9418 | * when a single PMU is going away. | |
9419 | */ | |
9420 | if (pmu->task_ctx_nr > perf_invalid_context) | |
9421 | return; | |
9422 | ||
8dc85d54 | 9423 | mutex_lock(&pmus_lock); |
51676957 | 9424 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 | 9425 | mutex_unlock(&pmus_lock); |
24f1e32c | 9426 | } |
6e855cd4 AS |
9427 | |
9428 | /* | |
9429 | * Let userspace know that this PMU supports address range filtering: | |
9430 | */ | |
9431 | static ssize_t nr_addr_filters_show(struct device *dev, | |
9432 | struct device_attribute *attr, | |
9433 | char *page) | |
9434 | { | |
9435 | struct pmu *pmu = dev_get_drvdata(dev); | |
9436 | ||
9437 | return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters); | |
9438 | } | |
9439 | DEVICE_ATTR_RO(nr_addr_filters); | |
9440 | ||
2e80a82a | 9441 | static struct idr pmu_idr; |
d6d020e9 | 9442 | |
abe43400 PZ |
9443 | static ssize_t |
9444 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
9445 | { | |
9446 | struct pmu *pmu = dev_get_drvdata(dev); | |
9447 | ||
9448 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
9449 | } | |
90826ca7 | 9450 | static DEVICE_ATTR_RO(type); |
abe43400 | 9451 | |
62b85639 SE |
9452 | static ssize_t |
9453 | perf_event_mux_interval_ms_show(struct device *dev, | |
9454 | struct device_attribute *attr, | |
9455 | char *page) | |
9456 | { | |
9457 | struct pmu *pmu = dev_get_drvdata(dev); | |
9458 | ||
9459 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
9460 | } | |
9461 | ||
272325c4 PZ |
9462 | static DEFINE_MUTEX(mux_interval_mutex); |
9463 | ||
62b85639 SE |
9464 | static ssize_t |
9465 | perf_event_mux_interval_ms_store(struct device *dev, | |
9466 | struct device_attribute *attr, | |
9467 | const char *buf, size_t count) | |
9468 | { | |
9469 | struct pmu *pmu = dev_get_drvdata(dev); | |
9470 | int timer, cpu, ret; | |
9471 | ||
9472 | ret = kstrtoint(buf, 0, &timer); | |
9473 | if (ret) | |
9474 | return ret; | |
9475 | ||
9476 | if (timer < 1) | |
9477 | return -EINVAL; | |
9478 | ||
9479 | /* same value, noting to do */ | |
9480 | if (timer == pmu->hrtimer_interval_ms) | |
9481 | return count; | |
9482 | ||
272325c4 | 9483 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
9484 | pmu->hrtimer_interval_ms = timer; |
9485 | ||
9486 | /* update all cpuctx for this PMU */ | |
a63fbed7 | 9487 | cpus_read_lock(); |
272325c4 | 9488 | for_each_online_cpu(cpu) { |
62b85639 SE |
9489 | struct perf_cpu_context *cpuctx; |
9490 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
9491 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
9492 | ||
272325c4 PZ |
9493 | cpu_function_call(cpu, |
9494 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 9495 | } |
a63fbed7 | 9496 | cpus_read_unlock(); |
272325c4 | 9497 | mutex_unlock(&mux_interval_mutex); |
62b85639 SE |
9498 | |
9499 | return count; | |
9500 | } | |
90826ca7 | 9501 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 9502 | |
90826ca7 GKH |
9503 | static struct attribute *pmu_dev_attrs[] = { |
9504 | &dev_attr_type.attr, | |
9505 | &dev_attr_perf_event_mux_interval_ms.attr, | |
9506 | NULL, | |
abe43400 | 9507 | }; |
90826ca7 | 9508 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
9509 | |
9510 | static int pmu_bus_running; | |
9511 | static struct bus_type pmu_bus = { | |
9512 | .name = "event_source", | |
90826ca7 | 9513 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
9514 | }; |
9515 | ||
9516 | static void pmu_dev_release(struct device *dev) | |
9517 | { | |
9518 | kfree(dev); | |
9519 | } | |
9520 | ||
9521 | static int pmu_dev_alloc(struct pmu *pmu) | |
9522 | { | |
9523 | int ret = -ENOMEM; | |
9524 | ||
9525 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
9526 | if (!pmu->dev) | |
9527 | goto out; | |
9528 | ||
0c9d42ed | 9529 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
9530 | device_initialize(pmu->dev); |
9531 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
9532 | if (ret) | |
9533 | goto free_dev; | |
9534 | ||
9535 | dev_set_drvdata(pmu->dev, pmu); | |
9536 | pmu->dev->bus = &pmu_bus; | |
9537 | pmu->dev->release = pmu_dev_release; | |
9538 | ret = device_add(pmu->dev); | |
9539 | if (ret) | |
9540 | goto free_dev; | |
9541 | ||
6e855cd4 AS |
9542 | /* For PMUs with address filters, throw in an extra attribute: */ |
9543 | if (pmu->nr_addr_filters) | |
9544 | ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters); | |
9545 | ||
9546 | if (ret) | |
9547 | goto del_dev; | |
9548 | ||
abe43400 PZ |
9549 | out: |
9550 | return ret; | |
9551 | ||
6e855cd4 AS |
9552 | del_dev: |
9553 | device_del(pmu->dev); | |
9554 | ||
abe43400 PZ |
9555 | free_dev: |
9556 | put_device(pmu->dev); | |
9557 | goto out; | |
9558 | } | |
9559 | ||
547e9fd7 | 9560 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 9561 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 9562 | |
03d8e80b | 9563 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 9564 | { |
108b02cf | 9565 | int cpu, ret; |
24f1e32c | 9566 | |
b0a873eb | 9567 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
9568 | ret = -ENOMEM; |
9569 | pmu->pmu_disable_count = alloc_percpu(int); | |
9570 | if (!pmu->pmu_disable_count) | |
9571 | goto unlock; | |
f29ac756 | 9572 | |
2e80a82a PZ |
9573 | pmu->type = -1; |
9574 | if (!name) | |
9575 | goto skip_type; | |
9576 | pmu->name = name; | |
9577 | ||
9578 | if (type < 0) { | |
0e9c3be2 TH |
9579 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
9580 | if (type < 0) { | |
9581 | ret = type; | |
2e80a82a PZ |
9582 | goto free_pdc; |
9583 | } | |
9584 | } | |
9585 | pmu->type = type; | |
9586 | ||
abe43400 PZ |
9587 | if (pmu_bus_running) { |
9588 | ret = pmu_dev_alloc(pmu); | |
9589 | if (ret) | |
9590 | goto free_idr; | |
9591 | } | |
9592 | ||
2e80a82a | 9593 | skip_type: |
26657848 PZ |
9594 | if (pmu->task_ctx_nr == perf_hw_context) { |
9595 | static int hw_context_taken = 0; | |
9596 | ||
5101ef20 MR |
9597 | /* |
9598 | * Other than systems with heterogeneous CPUs, it never makes | |
9599 | * sense for two PMUs to share perf_hw_context. PMUs which are | |
9600 | * uncore must use perf_invalid_context. | |
9601 | */ | |
9602 | if (WARN_ON_ONCE(hw_context_taken && | |
9603 | !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS))) | |
26657848 PZ |
9604 | pmu->task_ctx_nr = perf_invalid_context; |
9605 | ||
9606 | hw_context_taken = 1; | |
9607 | } | |
9608 | ||
8dc85d54 PZ |
9609 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
9610 | if (pmu->pmu_cpu_context) | |
9611 | goto got_cpu_context; | |
f29ac756 | 9612 | |
c4814202 | 9613 | ret = -ENOMEM; |
108b02cf PZ |
9614 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
9615 | if (!pmu->pmu_cpu_context) | |
abe43400 | 9616 | goto free_dev; |
f344011c | 9617 | |
108b02cf PZ |
9618 | for_each_possible_cpu(cpu) { |
9619 | struct perf_cpu_context *cpuctx; | |
9620 | ||
9621 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 9622 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 9623 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 9624 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 9625 | cpuctx->ctx.pmu = pmu; |
a63fbed7 | 9626 | cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask); |
9e630205 | 9627 | |
272325c4 | 9628 | __perf_mux_hrtimer_init(cpuctx, cpu); |
108b02cf | 9629 | } |
76e1d904 | 9630 | |
8dc85d54 | 9631 | got_cpu_context: |
ad5133b7 PZ |
9632 | if (!pmu->start_txn) { |
9633 | if (pmu->pmu_enable) { | |
9634 | /* | |
9635 | * If we have pmu_enable/pmu_disable calls, install | |
9636 | * transaction stubs that use that to try and batch | |
9637 | * hardware accesses. | |
9638 | */ | |
9639 | pmu->start_txn = perf_pmu_start_txn; | |
9640 | pmu->commit_txn = perf_pmu_commit_txn; | |
9641 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
9642 | } else { | |
fbbe0701 | 9643 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
9644 | pmu->commit_txn = perf_pmu_nop_int; |
9645 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 9646 | } |
5c92d124 | 9647 | } |
15dbf27c | 9648 | |
ad5133b7 PZ |
9649 | if (!pmu->pmu_enable) { |
9650 | pmu->pmu_enable = perf_pmu_nop_void; | |
9651 | pmu->pmu_disable = perf_pmu_nop_void; | |
9652 | } | |
9653 | ||
35edc2a5 PZ |
9654 | if (!pmu->event_idx) |
9655 | pmu->event_idx = perf_event_idx_default; | |
9656 | ||
b0a873eb | 9657 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 9658 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
9659 | ret = 0; |
9660 | unlock: | |
b0a873eb PZ |
9661 | mutex_unlock(&pmus_lock); |
9662 | ||
33696fc0 | 9663 | return ret; |
108b02cf | 9664 | |
abe43400 PZ |
9665 | free_dev: |
9666 | device_del(pmu->dev); | |
9667 | put_device(pmu->dev); | |
9668 | ||
2e80a82a PZ |
9669 | free_idr: |
9670 | if (pmu->type >= PERF_TYPE_MAX) | |
9671 | idr_remove(&pmu_idr, pmu->type); | |
9672 | ||
108b02cf PZ |
9673 | free_pdc: |
9674 | free_percpu(pmu->pmu_disable_count); | |
9675 | goto unlock; | |
f29ac756 | 9676 | } |
c464c76e | 9677 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 9678 | |
b0a873eb | 9679 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 9680 | { |
0933840a JO |
9681 | int remove_device; |
9682 | ||
b0a873eb | 9683 | mutex_lock(&pmus_lock); |
0933840a | 9684 | remove_device = pmu_bus_running; |
b0a873eb PZ |
9685 | list_del_rcu(&pmu->entry); |
9686 | mutex_unlock(&pmus_lock); | |
5c92d124 | 9687 | |
0475f9ea | 9688 | /* |
cde8e884 PZ |
9689 | * We dereference the pmu list under both SRCU and regular RCU, so |
9690 | * synchronize against both of those. | |
0475f9ea | 9691 | */ |
b0a873eb | 9692 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 9693 | synchronize_rcu(); |
d6d020e9 | 9694 | |
33696fc0 | 9695 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
9696 | if (pmu->type >= PERF_TYPE_MAX) |
9697 | idr_remove(&pmu_idr, pmu->type); | |
0933840a JO |
9698 | if (remove_device) { |
9699 | if (pmu->nr_addr_filters) | |
9700 | device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); | |
9701 | device_del(pmu->dev); | |
9702 | put_device(pmu->dev); | |
9703 | } | |
51676957 | 9704 | free_pmu_context(pmu); |
b0a873eb | 9705 | } |
c464c76e | 9706 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 9707 | |
cc34b98b MR |
9708 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
9709 | { | |
ccd41c86 | 9710 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
9711 | int ret; |
9712 | ||
9713 | if (!try_module_get(pmu->module)) | |
9714 | return -ENODEV; | |
ccd41c86 | 9715 | |
0c7296ca PZ |
9716 | /* |
9717 | * A number of pmu->event_init() methods iterate the sibling_list to, | |
9718 | * for example, validate if the group fits on the PMU. Therefore, | |
9719 | * if this is a sibling event, acquire the ctx->mutex to protect | |
9720 | * the sibling_list. | |
9721 | */ | |
9722 | if (event->group_leader != event && pmu->task_ctx_nr != perf_sw_context) { | |
8b10c5e2 PZ |
9723 | /* |
9724 | * This ctx->mutex can nest when we're called through | |
9725 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
9726 | */ | |
9727 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
9728 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
9729 | BUG_ON(!ctx); |
9730 | } | |
9731 | ||
cc34b98b MR |
9732 | event->pmu = pmu; |
9733 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
9734 | |
9735 | if (ctx) | |
9736 | perf_event_ctx_unlock(event->group_leader, ctx); | |
9737 | ||
cc34b98b MR |
9738 | if (ret) |
9739 | module_put(pmu->module); | |
9740 | ||
9741 | return ret; | |
9742 | } | |
9743 | ||
18ab2cd3 | 9744 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb | 9745 | { |
85c617ab | 9746 | struct pmu *pmu; |
b0a873eb | 9747 | int idx; |
940c5b29 | 9748 | int ret; |
b0a873eb PZ |
9749 | |
9750 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a | 9751 | |
40999312 KL |
9752 | /* Try parent's PMU first: */ |
9753 | if (event->parent && event->parent->pmu) { | |
9754 | pmu = event->parent->pmu; | |
9755 | ret = perf_try_init_event(pmu, event); | |
9756 | if (!ret) | |
9757 | goto unlock; | |
9758 | } | |
9759 | ||
2e80a82a PZ |
9760 | rcu_read_lock(); |
9761 | pmu = idr_find(&pmu_idr, event->attr.type); | |
9762 | rcu_read_unlock(); | |
940c5b29 | 9763 | if (pmu) { |
cc34b98b | 9764 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
9765 | if (ret) |
9766 | pmu = ERR_PTR(ret); | |
2e80a82a | 9767 | goto unlock; |
940c5b29 | 9768 | } |
2e80a82a | 9769 | |
b0a873eb | 9770 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 9771 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 9772 | if (!ret) |
e5f4d339 | 9773 | goto unlock; |
76e1d904 | 9774 | |
b0a873eb PZ |
9775 | if (ret != -ENOENT) { |
9776 | pmu = ERR_PTR(ret); | |
e5f4d339 | 9777 | goto unlock; |
f344011c | 9778 | } |
5c92d124 | 9779 | } |
e5f4d339 PZ |
9780 | pmu = ERR_PTR(-ENOENT); |
9781 | unlock: | |
b0a873eb | 9782 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 9783 | |
4aeb0b42 | 9784 | return pmu; |
5c92d124 IM |
9785 | } |
9786 | ||
f2fb6bef KL |
9787 | static void attach_sb_event(struct perf_event *event) |
9788 | { | |
9789 | struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu); | |
9790 | ||
9791 | raw_spin_lock(&pel->lock); | |
9792 | list_add_rcu(&event->sb_list, &pel->list); | |
9793 | raw_spin_unlock(&pel->lock); | |
9794 | } | |
9795 | ||
aab5b71e PZ |
9796 | /* |
9797 | * We keep a list of all !task (and therefore per-cpu) events | |
9798 | * that need to receive side-band records. | |
9799 | * | |
9800 | * This avoids having to scan all the various PMU per-cpu contexts | |
9801 | * looking for them. | |
9802 | */ | |
f2fb6bef KL |
9803 | static void account_pmu_sb_event(struct perf_event *event) |
9804 | { | |
a4f144eb | 9805 | if (is_sb_event(event)) |
f2fb6bef KL |
9806 | attach_sb_event(event); |
9807 | } | |
9808 | ||
4beb31f3 FW |
9809 | static void account_event_cpu(struct perf_event *event, int cpu) |
9810 | { | |
9811 | if (event->parent) | |
9812 | return; | |
9813 | ||
4beb31f3 FW |
9814 | if (is_cgroup_event(event)) |
9815 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
9816 | } | |
9817 | ||
555e0c1e FW |
9818 | /* Freq events need the tick to stay alive (see perf_event_task_tick). */ |
9819 | static void account_freq_event_nohz(void) | |
9820 | { | |
9821 | #ifdef CONFIG_NO_HZ_FULL | |
9822 | /* Lock so we don't race with concurrent unaccount */ | |
9823 | spin_lock(&nr_freq_lock); | |
9824 | if (atomic_inc_return(&nr_freq_events) == 1) | |
9825 | tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS); | |
9826 | spin_unlock(&nr_freq_lock); | |
9827 | #endif | |
9828 | } | |
9829 | ||
9830 | static void account_freq_event(void) | |
9831 | { | |
9832 | if (tick_nohz_full_enabled()) | |
9833 | account_freq_event_nohz(); | |
9834 | else | |
9835 | atomic_inc(&nr_freq_events); | |
9836 | } | |
9837 | ||
9838 | ||
766d6c07 FW |
9839 | static void account_event(struct perf_event *event) |
9840 | { | |
25432ae9 PZ |
9841 | bool inc = false; |
9842 | ||
4beb31f3 FW |
9843 | if (event->parent) |
9844 | return; | |
9845 | ||
766d6c07 | 9846 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 9847 | inc = true; |
766d6c07 FW |
9848 | if (event->attr.mmap || event->attr.mmap_data) |
9849 | atomic_inc(&nr_mmap_events); | |
9850 | if (event->attr.comm) | |
9851 | atomic_inc(&nr_comm_events); | |
e4222673 HB |
9852 | if (event->attr.namespaces) |
9853 | atomic_inc(&nr_namespaces_events); | |
766d6c07 FW |
9854 | if (event->attr.task) |
9855 | atomic_inc(&nr_task_events); | |
555e0c1e FW |
9856 | if (event->attr.freq) |
9857 | account_freq_event(); | |
45ac1403 AH |
9858 | if (event->attr.context_switch) { |
9859 | atomic_inc(&nr_switch_events); | |
25432ae9 | 9860 | inc = true; |
45ac1403 | 9861 | } |
4beb31f3 | 9862 | if (has_branch_stack(event)) |
25432ae9 | 9863 | inc = true; |
4beb31f3 | 9864 | if (is_cgroup_event(event)) |
25432ae9 PZ |
9865 | inc = true; |
9866 | ||
9107c89e | 9867 | if (inc) { |
5bce9db1 AS |
9868 | /* |
9869 | * We need the mutex here because static_branch_enable() | |
9870 | * must complete *before* the perf_sched_count increment | |
9871 | * becomes visible. | |
9872 | */ | |
9107c89e PZ |
9873 | if (atomic_inc_not_zero(&perf_sched_count)) |
9874 | goto enabled; | |
9875 | ||
9876 | mutex_lock(&perf_sched_mutex); | |
9877 | if (!atomic_read(&perf_sched_count)) { | |
9878 | static_branch_enable(&perf_sched_events); | |
9879 | /* | |
9880 | * Guarantee that all CPUs observe they key change and | |
9881 | * call the perf scheduling hooks before proceeding to | |
9882 | * install events that need them. | |
9883 | */ | |
9884 | synchronize_sched(); | |
9885 | } | |
9886 | /* | |
9887 | * Now that we have waited for the sync_sched(), allow further | |
9888 | * increments to by-pass the mutex. | |
9889 | */ | |
9890 | atomic_inc(&perf_sched_count); | |
9891 | mutex_unlock(&perf_sched_mutex); | |
9892 | } | |
9893 | enabled: | |
4beb31f3 FW |
9894 | |
9895 | account_event_cpu(event, event->cpu); | |
f2fb6bef KL |
9896 | |
9897 | account_pmu_sb_event(event); | |
766d6c07 FW |
9898 | } |
9899 | ||
0793a61d | 9900 | /* |
cdd6c482 | 9901 | * Allocate and initialize a event structure |
0793a61d | 9902 | */ |
cdd6c482 | 9903 | static struct perf_event * |
c3f00c70 | 9904 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
9905 | struct task_struct *task, |
9906 | struct perf_event *group_leader, | |
9907 | struct perf_event *parent_event, | |
4dc0da86 | 9908 | perf_overflow_handler_t overflow_handler, |
79dff51e | 9909 | void *context, int cgroup_fd) |
0793a61d | 9910 | { |
51b0fe39 | 9911 | struct pmu *pmu; |
cdd6c482 IM |
9912 | struct perf_event *event; |
9913 | struct hw_perf_event *hwc; | |
90983b16 | 9914 | long err = -EINVAL; |
0793a61d | 9915 | |
66832eb4 ON |
9916 | if ((unsigned)cpu >= nr_cpu_ids) { |
9917 | if (!task || cpu != -1) | |
9918 | return ERR_PTR(-EINVAL); | |
9919 | } | |
9920 | ||
c3f00c70 | 9921 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 9922 | if (!event) |
d5d2bc0d | 9923 | return ERR_PTR(-ENOMEM); |
0793a61d | 9924 | |
04289bb9 | 9925 | /* |
cdd6c482 | 9926 | * Single events are their own group leaders, with an |
04289bb9 IM |
9927 | * empty sibling list: |
9928 | */ | |
9929 | if (!group_leader) | |
cdd6c482 | 9930 | group_leader = event; |
04289bb9 | 9931 | |
cdd6c482 IM |
9932 | mutex_init(&event->child_mutex); |
9933 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 9934 | |
cdd6c482 IM |
9935 | INIT_LIST_HEAD(&event->event_entry); |
9936 | INIT_LIST_HEAD(&event->sibling_list); | |
6668128a | 9937 | INIT_LIST_HEAD(&event->active_list); |
8e1a2031 | 9938 | init_event_group(event); |
10c6db11 | 9939 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 9940 | INIT_LIST_HEAD(&event->active_entry); |
375637bc | 9941 | INIT_LIST_HEAD(&event->addr_filters.list); |
f3ae75de SE |
9942 | INIT_HLIST_NODE(&event->hlist_entry); |
9943 | ||
10c6db11 | 9944 | |
cdd6c482 | 9945 | init_waitqueue_head(&event->waitq); |
e360adbe | 9946 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 9947 | |
cdd6c482 | 9948 | mutex_init(&event->mmap_mutex); |
375637bc | 9949 | raw_spin_lock_init(&event->addr_filters.lock); |
7b732a75 | 9950 | |
a6fa941d | 9951 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
9952 | event->cpu = cpu; |
9953 | event->attr = *attr; | |
9954 | event->group_leader = group_leader; | |
9955 | event->pmu = NULL; | |
cdd6c482 | 9956 | event->oncpu = -1; |
a96bbc16 | 9957 | |
cdd6c482 | 9958 | event->parent = parent_event; |
b84fbc9f | 9959 | |
17cf22c3 | 9960 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 9961 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 9962 | |
cdd6c482 | 9963 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 9964 | |
d580ff86 PZ |
9965 | if (task) { |
9966 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 9967 | /* |
50f16a8b PZ |
9968 | * XXX pmu::event_init needs to know what task to account to |
9969 | * and we cannot use the ctx information because we need the | |
9970 | * pmu before we get a ctx. | |
d580ff86 | 9971 | */ |
621b6d2e | 9972 | get_task_struct(task); |
50f16a8b | 9973 | event->hw.target = task; |
d580ff86 PZ |
9974 | } |
9975 | ||
34f43927 PZ |
9976 | event->clock = &local_clock; |
9977 | if (parent_event) | |
9978 | event->clock = parent_event->clock; | |
9979 | ||
4dc0da86 | 9980 | if (!overflow_handler && parent_event) { |
b326e956 | 9981 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 | 9982 | context = parent_event->overflow_handler_context; |
f1e4ba5b | 9983 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING) |
aa6a5f3c AS |
9984 | if (overflow_handler == bpf_overflow_handler) { |
9985 | struct bpf_prog *prog = bpf_prog_inc(parent_event->prog); | |
9986 | ||
9987 | if (IS_ERR(prog)) { | |
9988 | err = PTR_ERR(prog); | |
9989 | goto err_ns; | |
9990 | } | |
9991 | event->prog = prog; | |
9992 | event->orig_overflow_handler = | |
9993 | parent_event->orig_overflow_handler; | |
9994 | } | |
9995 | #endif | |
4dc0da86 | 9996 | } |
66832eb4 | 9997 | |
1879445d WN |
9998 | if (overflow_handler) { |
9999 | event->overflow_handler = overflow_handler; | |
10000 | event->overflow_handler_context = context; | |
9ecda41a WN |
10001 | } else if (is_write_backward(event)){ |
10002 | event->overflow_handler = perf_event_output_backward; | |
10003 | event->overflow_handler_context = NULL; | |
1879445d | 10004 | } else { |
9ecda41a | 10005 | event->overflow_handler = perf_event_output_forward; |
1879445d WN |
10006 | event->overflow_handler_context = NULL; |
10007 | } | |
97eaf530 | 10008 | |
0231bb53 | 10009 | perf_event__state_init(event); |
a86ed508 | 10010 | |
4aeb0b42 | 10011 | pmu = NULL; |
b8e83514 | 10012 | |
cdd6c482 | 10013 | hwc = &event->hw; |
bd2b5b12 | 10014 | hwc->sample_period = attr->sample_period; |
0d48696f | 10015 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 10016 | hwc->sample_period = 1; |
eced1dfc | 10017 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 10018 | |
e7850595 | 10019 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 10020 | |
2023b359 | 10021 | /* |
ba5213ae PZ |
10022 | * We currently do not support PERF_SAMPLE_READ on inherited events. |
10023 | * See perf_output_read(). | |
2023b359 | 10024 | */ |
ba5213ae | 10025 | if (attr->inherit && (attr->sample_type & PERF_SAMPLE_READ)) |
90983b16 | 10026 | goto err_ns; |
a46a2300 YZ |
10027 | |
10028 | if (!has_branch_stack(event)) | |
10029 | event->attr.branch_sample_type = 0; | |
2023b359 | 10030 | |
79dff51e MF |
10031 | if (cgroup_fd != -1) { |
10032 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
10033 | if (err) | |
10034 | goto err_ns; | |
10035 | } | |
10036 | ||
b0a873eb | 10037 | pmu = perf_init_event(event); |
85c617ab | 10038 | if (IS_ERR(pmu)) { |
4aeb0b42 | 10039 | err = PTR_ERR(pmu); |
90983b16 | 10040 | goto err_ns; |
621a01ea | 10041 | } |
d5d2bc0d | 10042 | |
bed5b25a AS |
10043 | err = exclusive_event_init(event); |
10044 | if (err) | |
10045 | goto err_pmu; | |
10046 | ||
375637bc AS |
10047 | if (has_addr_filter(event)) { |
10048 | event->addr_filters_offs = kcalloc(pmu->nr_addr_filters, | |
10049 | sizeof(unsigned long), | |
10050 | GFP_KERNEL); | |
36cc2b92 DC |
10051 | if (!event->addr_filters_offs) { |
10052 | err = -ENOMEM; | |
375637bc | 10053 | goto err_per_task; |
36cc2b92 | 10054 | } |
375637bc AS |
10055 | |
10056 | /* force hw sync on the address filters */ | |
10057 | event->addr_filters_gen = 1; | |
10058 | } | |
10059 | ||
cdd6c482 | 10060 | if (!event->parent) { |
927c7a9e | 10061 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
97c79a38 | 10062 | err = get_callchain_buffers(attr->sample_max_stack); |
90983b16 | 10063 | if (err) |
375637bc | 10064 | goto err_addr_filters; |
d010b332 | 10065 | } |
f344011c | 10066 | } |
9ee318a7 | 10067 | |
927a5570 AS |
10068 | /* symmetric to unaccount_event() in _free_event() */ |
10069 | account_event(event); | |
10070 | ||
cdd6c482 | 10071 | return event; |
90983b16 | 10072 | |
375637bc AS |
10073 | err_addr_filters: |
10074 | kfree(event->addr_filters_offs); | |
10075 | ||
bed5b25a AS |
10076 | err_per_task: |
10077 | exclusive_event_destroy(event); | |
10078 | ||
90983b16 FW |
10079 | err_pmu: |
10080 | if (event->destroy) | |
10081 | event->destroy(event); | |
c464c76e | 10082 | module_put(pmu->module); |
90983b16 | 10083 | err_ns: |
79dff51e MF |
10084 | if (is_cgroup_event(event)) |
10085 | perf_detach_cgroup(event); | |
90983b16 FW |
10086 | if (event->ns) |
10087 | put_pid_ns(event->ns); | |
621b6d2e PB |
10088 | if (event->hw.target) |
10089 | put_task_struct(event->hw.target); | |
90983b16 FW |
10090 | kfree(event); |
10091 | ||
10092 | return ERR_PTR(err); | |
0793a61d TG |
10093 | } |
10094 | ||
cdd6c482 IM |
10095 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
10096 | struct perf_event_attr *attr) | |
974802ea | 10097 | { |
974802ea | 10098 | u32 size; |
cdf8073d | 10099 | int ret; |
974802ea PZ |
10100 | |
10101 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
10102 | return -EFAULT; | |
10103 | ||
10104 | /* | |
10105 | * zero the full structure, so that a short copy will be nice. | |
10106 | */ | |
10107 | memset(attr, 0, sizeof(*attr)); | |
10108 | ||
10109 | ret = get_user(size, &uattr->size); | |
10110 | if (ret) | |
10111 | return ret; | |
10112 | ||
10113 | if (size > PAGE_SIZE) /* silly large */ | |
10114 | goto err_size; | |
10115 | ||
10116 | if (!size) /* abi compat */ | |
10117 | size = PERF_ATTR_SIZE_VER0; | |
10118 | ||
10119 | if (size < PERF_ATTR_SIZE_VER0) | |
10120 | goto err_size; | |
10121 | ||
10122 | /* | |
10123 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
10124 | * ensure all the unknown bits are 0 - i.e. new |
10125 | * user-space does not rely on any kernel feature | |
10126 | * extensions we dont know about yet. | |
974802ea PZ |
10127 | */ |
10128 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
10129 | unsigned char __user *addr; |
10130 | unsigned char __user *end; | |
10131 | unsigned char val; | |
974802ea | 10132 | |
cdf8073d IS |
10133 | addr = (void __user *)uattr + sizeof(*attr); |
10134 | end = (void __user *)uattr + size; | |
974802ea | 10135 | |
cdf8073d | 10136 | for (; addr < end; addr++) { |
974802ea PZ |
10137 | ret = get_user(val, addr); |
10138 | if (ret) | |
10139 | return ret; | |
10140 | if (val) | |
10141 | goto err_size; | |
10142 | } | |
b3e62e35 | 10143 | size = sizeof(*attr); |
974802ea PZ |
10144 | } |
10145 | ||
10146 | ret = copy_from_user(attr, uattr, size); | |
10147 | if (ret) | |
10148 | return -EFAULT; | |
10149 | ||
f12f42ac MX |
10150 | attr->size = size; |
10151 | ||
cd757645 | 10152 | if (attr->__reserved_1) |
974802ea PZ |
10153 | return -EINVAL; |
10154 | ||
10155 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
10156 | return -EINVAL; | |
10157 | ||
10158 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
10159 | return -EINVAL; | |
10160 | ||
bce38cd5 SE |
10161 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
10162 | u64 mask = attr->branch_sample_type; | |
10163 | ||
10164 | /* only using defined bits */ | |
10165 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
10166 | return -EINVAL; | |
10167 | ||
10168 | /* at least one branch bit must be set */ | |
10169 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
10170 | return -EINVAL; | |
10171 | ||
bce38cd5 SE |
10172 | /* propagate priv level, when not set for branch */ |
10173 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
10174 | ||
10175 | /* exclude_kernel checked on syscall entry */ | |
10176 | if (!attr->exclude_kernel) | |
10177 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
10178 | ||
10179 | if (!attr->exclude_user) | |
10180 | mask |= PERF_SAMPLE_BRANCH_USER; | |
10181 | ||
10182 | if (!attr->exclude_hv) | |
10183 | mask |= PERF_SAMPLE_BRANCH_HV; | |
10184 | /* | |
10185 | * adjust user setting (for HW filter setup) | |
10186 | */ | |
10187 | attr->branch_sample_type = mask; | |
10188 | } | |
e712209a SE |
10189 | /* privileged levels capture (kernel, hv): check permissions */ |
10190 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
10191 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
10192 | return -EACCES; | |
bce38cd5 | 10193 | } |
4018994f | 10194 | |
c5ebcedb | 10195 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 10196 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
10197 | if (ret) |
10198 | return ret; | |
10199 | } | |
10200 | ||
10201 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
10202 | if (!arch_perf_have_user_stack_dump()) | |
10203 | return -ENOSYS; | |
10204 | ||
10205 | /* | |
10206 | * We have __u32 type for the size, but so far | |
10207 | * we can only use __u16 as maximum due to the | |
10208 | * __u16 sample size limit. | |
10209 | */ | |
10210 | if (attr->sample_stack_user >= USHRT_MAX) | |
78b562fb | 10211 | return -EINVAL; |
c5ebcedb | 10212 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) |
78b562fb | 10213 | return -EINVAL; |
c5ebcedb | 10214 | } |
4018994f | 10215 | |
5f970521 JO |
10216 | if (!attr->sample_max_stack) |
10217 | attr->sample_max_stack = sysctl_perf_event_max_stack; | |
10218 | ||
60e2364e SE |
10219 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
10220 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
10221 | out: |
10222 | return ret; | |
10223 | ||
10224 | err_size: | |
10225 | put_user(sizeof(*attr), &uattr->size); | |
10226 | ret = -E2BIG; | |
10227 | goto out; | |
10228 | } | |
10229 | ||
ac9721f3 PZ |
10230 | static int |
10231 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 10232 | { |
b69cf536 | 10233 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
10234 | int ret = -EINVAL; |
10235 | ||
ac9721f3 | 10236 | if (!output_event) |
a4be7c27 PZ |
10237 | goto set; |
10238 | ||
ac9721f3 PZ |
10239 | /* don't allow circular references */ |
10240 | if (event == output_event) | |
a4be7c27 PZ |
10241 | goto out; |
10242 | ||
0f139300 PZ |
10243 | /* |
10244 | * Don't allow cross-cpu buffers | |
10245 | */ | |
10246 | if (output_event->cpu != event->cpu) | |
10247 | goto out; | |
10248 | ||
10249 | /* | |
76369139 | 10250 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
10251 | */ |
10252 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
10253 | goto out; | |
10254 | ||
34f43927 PZ |
10255 | /* |
10256 | * Mixing clocks in the same buffer is trouble you don't need. | |
10257 | */ | |
10258 | if (output_event->clock != event->clock) | |
10259 | goto out; | |
10260 | ||
9ecda41a WN |
10261 | /* |
10262 | * Either writing ring buffer from beginning or from end. | |
10263 | * Mixing is not allowed. | |
10264 | */ | |
10265 | if (is_write_backward(output_event) != is_write_backward(event)) | |
10266 | goto out; | |
10267 | ||
45bfb2e5 PZ |
10268 | /* |
10269 | * If both events generate aux data, they must be on the same PMU | |
10270 | */ | |
10271 | if (has_aux(event) && has_aux(output_event) && | |
10272 | event->pmu != output_event->pmu) | |
10273 | goto out; | |
10274 | ||
a4be7c27 | 10275 | set: |
cdd6c482 | 10276 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
10277 | /* Can't redirect output if we've got an active mmap() */ |
10278 | if (atomic_read(&event->mmap_count)) | |
10279 | goto unlock; | |
a4be7c27 | 10280 | |
ac9721f3 | 10281 | if (output_event) { |
76369139 FW |
10282 | /* get the rb we want to redirect to */ |
10283 | rb = ring_buffer_get(output_event); | |
10284 | if (!rb) | |
ac9721f3 | 10285 | goto unlock; |
a4be7c27 PZ |
10286 | } |
10287 | ||
b69cf536 | 10288 | ring_buffer_attach(event, rb); |
9bb5d40c | 10289 | |
a4be7c27 | 10290 | ret = 0; |
ac9721f3 PZ |
10291 | unlock: |
10292 | mutex_unlock(&event->mmap_mutex); | |
10293 | ||
a4be7c27 | 10294 | out: |
a4be7c27 PZ |
10295 | return ret; |
10296 | } | |
10297 | ||
f63a8daa PZ |
10298 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
10299 | { | |
10300 | if (b < a) | |
10301 | swap(a, b); | |
10302 | ||
10303 | mutex_lock(a); | |
10304 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
10305 | } | |
10306 | ||
34f43927 PZ |
10307 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
10308 | { | |
10309 | bool nmi_safe = false; | |
10310 | ||
10311 | switch (clk_id) { | |
10312 | case CLOCK_MONOTONIC: | |
10313 | event->clock = &ktime_get_mono_fast_ns; | |
10314 | nmi_safe = true; | |
10315 | break; | |
10316 | ||
10317 | case CLOCK_MONOTONIC_RAW: | |
10318 | event->clock = &ktime_get_raw_fast_ns; | |
10319 | nmi_safe = true; | |
10320 | break; | |
10321 | ||
10322 | case CLOCK_REALTIME: | |
10323 | event->clock = &ktime_get_real_ns; | |
10324 | break; | |
10325 | ||
10326 | case CLOCK_BOOTTIME: | |
10327 | event->clock = &ktime_get_boot_ns; | |
10328 | break; | |
10329 | ||
10330 | case CLOCK_TAI: | |
10331 | event->clock = &ktime_get_tai_ns; | |
10332 | break; | |
10333 | ||
10334 | default: | |
10335 | return -EINVAL; | |
10336 | } | |
10337 | ||
10338 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
10339 | return -EINVAL; | |
10340 | ||
10341 | return 0; | |
10342 | } | |
10343 | ||
321027c1 PZ |
10344 | /* |
10345 | * Variation on perf_event_ctx_lock_nested(), except we take two context | |
10346 | * mutexes. | |
10347 | */ | |
10348 | static struct perf_event_context * | |
10349 | __perf_event_ctx_lock_double(struct perf_event *group_leader, | |
10350 | struct perf_event_context *ctx) | |
10351 | { | |
10352 | struct perf_event_context *gctx; | |
10353 | ||
10354 | again: | |
10355 | rcu_read_lock(); | |
10356 | gctx = READ_ONCE(group_leader->ctx); | |
10357 | if (!atomic_inc_not_zero(&gctx->refcount)) { | |
10358 | rcu_read_unlock(); | |
10359 | goto again; | |
10360 | } | |
10361 | rcu_read_unlock(); | |
10362 | ||
10363 | mutex_lock_double(&gctx->mutex, &ctx->mutex); | |
10364 | ||
10365 | if (group_leader->ctx != gctx) { | |
10366 | mutex_unlock(&ctx->mutex); | |
10367 | mutex_unlock(&gctx->mutex); | |
10368 | put_ctx(gctx); | |
10369 | goto again; | |
10370 | } | |
10371 | ||
10372 | return gctx; | |
10373 | } | |
10374 | ||
0793a61d | 10375 | /** |
cdd6c482 | 10376 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 10377 | * |
cdd6c482 | 10378 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 10379 | * @pid: target pid |
9f66a381 | 10380 | * @cpu: target cpu |
cdd6c482 | 10381 | * @group_fd: group leader event fd |
0793a61d | 10382 | */ |
cdd6c482 IM |
10383 | SYSCALL_DEFINE5(perf_event_open, |
10384 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 10385 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 10386 | { |
b04243ef PZ |
10387 | struct perf_event *group_leader = NULL, *output_event = NULL; |
10388 | struct perf_event *event, *sibling; | |
cdd6c482 | 10389 | struct perf_event_attr attr; |
f63a8daa | 10390 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 10391 | struct file *event_file = NULL; |
2903ff01 | 10392 | struct fd group = {NULL, 0}; |
38a81da2 | 10393 | struct task_struct *task = NULL; |
89a1e187 | 10394 | struct pmu *pmu; |
ea635c64 | 10395 | int event_fd; |
b04243ef | 10396 | int move_group = 0; |
dc86cabe | 10397 | int err; |
a21b0b35 | 10398 | int f_flags = O_RDWR; |
79dff51e | 10399 | int cgroup_fd = -1; |
0793a61d | 10400 | |
2743a5b0 | 10401 | /* for future expandability... */ |
e5d1367f | 10402 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
10403 | return -EINVAL; |
10404 | ||
dc86cabe IM |
10405 | err = perf_copy_attr(attr_uptr, &attr); |
10406 | if (err) | |
10407 | return err; | |
eab656ae | 10408 | |
0764771d PZ |
10409 | if (!attr.exclude_kernel) { |
10410 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
10411 | return -EACCES; | |
10412 | } | |
10413 | ||
e4222673 HB |
10414 | if (attr.namespaces) { |
10415 | if (!capable(CAP_SYS_ADMIN)) | |
10416 | return -EACCES; | |
10417 | } | |
10418 | ||
df58ab24 | 10419 | if (attr.freq) { |
cdd6c482 | 10420 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 10421 | return -EINVAL; |
0819b2e3 PZ |
10422 | } else { |
10423 | if (attr.sample_period & (1ULL << 63)) | |
10424 | return -EINVAL; | |
df58ab24 PZ |
10425 | } |
10426 | ||
fc7ce9c7 KL |
10427 | /* Only privileged users can get physical addresses */ |
10428 | if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) && | |
10429 | perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
10430 | return -EACCES; | |
10431 | ||
e5d1367f SE |
10432 | /* |
10433 | * In cgroup mode, the pid argument is used to pass the fd | |
10434 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
10435 | * designates the cpu on which to monitor threads from that | |
10436 | * cgroup. | |
10437 | */ | |
10438 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
10439 | return -EINVAL; | |
10440 | ||
a21b0b35 YD |
10441 | if (flags & PERF_FLAG_FD_CLOEXEC) |
10442 | f_flags |= O_CLOEXEC; | |
10443 | ||
10444 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
10445 | if (event_fd < 0) |
10446 | return event_fd; | |
10447 | ||
ac9721f3 | 10448 | if (group_fd != -1) { |
2903ff01 AV |
10449 | err = perf_fget_light(group_fd, &group); |
10450 | if (err) | |
d14b12d7 | 10451 | goto err_fd; |
2903ff01 | 10452 | group_leader = group.file->private_data; |
ac9721f3 PZ |
10453 | if (flags & PERF_FLAG_FD_OUTPUT) |
10454 | output_event = group_leader; | |
10455 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
10456 | group_leader = NULL; | |
10457 | } | |
10458 | ||
e5d1367f | 10459 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
10460 | task = find_lively_task_by_vpid(pid); |
10461 | if (IS_ERR(task)) { | |
10462 | err = PTR_ERR(task); | |
10463 | goto err_group_fd; | |
10464 | } | |
10465 | } | |
10466 | ||
1f4ee503 PZ |
10467 | if (task && group_leader && |
10468 | group_leader->attr.inherit != attr.inherit) { | |
10469 | err = -EINVAL; | |
10470 | goto err_task; | |
10471 | } | |
10472 | ||
79c9ce57 PZ |
10473 | if (task) { |
10474 | err = mutex_lock_interruptible(&task->signal->cred_guard_mutex); | |
10475 | if (err) | |
e5aeee51 | 10476 | goto err_task; |
79c9ce57 PZ |
10477 | |
10478 | /* | |
10479 | * Reuse ptrace permission checks for now. | |
10480 | * | |
10481 | * We must hold cred_guard_mutex across this and any potential | |
10482 | * perf_install_in_context() call for this new event to | |
10483 | * serialize against exec() altering our credentials (and the | |
10484 | * perf_event_exit_task() that could imply). | |
10485 | */ | |
10486 | err = -EACCES; | |
10487 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) | |
10488 | goto err_cred; | |
10489 | } | |
10490 | ||
79dff51e MF |
10491 | if (flags & PERF_FLAG_PID_CGROUP) |
10492 | cgroup_fd = pid; | |
10493 | ||
4dc0da86 | 10494 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 10495 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
10496 | if (IS_ERR(event)) { |
10497 | err = PTR_ERR(event); | |
79c9ce57 | 10498 | goto err_cred; |
d14b12d7 SE |
10499 | } |
10500 | ||
53b25335 VW |
10501 | if (is_sampling_event(event)) { |
10502 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
a1396555 | 10503 | err = -EOPNOTSUPP; |
53b25335 VW |
10504 | goto err_alloc; |
10505 | } | |
10506 | } | |
10507 | ||
89a1e187 PZ |
10508 | /* |
10509 | * Special case software events and allow them to be part of | |
10510 | * any hardware group. | |
10511 | */ | |
10512 | pmu = event->pmu; | |
b04243ef | 10513 | |
34f43927 PZ |
10514 | if (attr.use_clockid) { |
10515 | err = perf_event_set_clock(event, attr.clockid); | |
10516 | if (err) | |
10517 | goto err_alloc; | |
10518 | } | |
10519 | ||
4ff6a8de DCC |
10520 | if (pmu->task_ctx_nr == perf_sw_context) |
10521 | event->event_caps |= PERF_EV_CAP_SOFTWARE; | |
10522 | ||
a1150c20 SL |
10523 | if (group_leader) { |
10524 | if (is_software_event(event) && | |
10525 | !in_software_context(group_leader)) { | |
b04243ef | 10526 | /* |
a1150c20 SL |
10527 | * If the event is a sw event, but the group_leader |
10528 | * is on hw context. | |
b04243ef | 10529 | * |
a1150c20 SL |
10530 | * Allow the addition of software events to hw |
10531 | * groups, this is safe because software events | |
10532 | * never fail to schedule. | |
b04243ef | 10533 | */ |
a1150c20 SL |
10534 | pmu = group_leader->ctx->pmu; |
10535 | } else if (!is_software_event(event) && | |
10536 | is_software_event(group_leader) && | |
4ff6a8de | 10537 | (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) { |
b04243ef PZ |
10538 | /* |
10539 | * In case the group is a pure software group, and we | |
10540 | * try to add a hardware event, move the whole group to | |
10541 | * the hardware context. | |
10542 | */ | |
10543 | move_group = 1; | |
10544 | } | |
10545 | } | |
89a1e187 PZ |
10546 | |
10547 | /* | |
10548 | * Get the target context (task or percpu): | |
10549 | */ | |
4af57ef2 | 10550 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
10551 | if (IS_ERR(ctx)) { |
10552 | err = PTR_ERR(ctx); | |
c6be5a5c | 10553 | goto err_alloc; |
89a1e187 PZ |
10554 | } |
10555 | ||
bed5b25a AS |
10556 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
10557 | err = -EBUSY; | |
10558 | goto err_context; | |
10559 | } | |
10560 | ||
ccff286d | 10561 | /* |
cdd6c482 | 10562 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 10563 | */ |
ac9721f3 | 10564 | if (group_leader) { |
dc86cabe | 10565 | err = -EINVAL; |
04289bb9 | 10566 | |
04289bb9 | 10567 | /* |
ccff286d IM |
10568 | * Do not allow a recursive hierarchy (this new sibling |
10569 | * becoming part of another group-sibling): | |
10570 | */ | |
10571 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 10572 | goto err_context; |
34f43927 PZ |
10573 | |
10574 | /* All events in a group should have the same clock */ | |
10575 | if (group_leader->clock != event->clock) | |
10576 | goto err_context; | |
10577 | ||
ccff286d | 10578 | /* |
64aee2a9 MR |
10579 | * Make sure we're both events for the same CPU; |
10580 | * grouping events for different CPUs is broken; since | |
10581 | * you can never concurrently schedule them anyhow. | |
04289bb9 | 10582 | */ |
64aee2a9 MR |
10583 | if (group_leader->cpu != event->cpu) |
10584 | goto err_context; | |
c3c87e77 | 10585 | |
64aee2a9 MR |
10586 | /* |
10587 | * Make sure we're both on the same task, or both | |
10588 | * per-CPU events. | |
10589 | */ | |
10590 | if (group_leader->ctx->task != ctx->task) | |
10591 | goto err_context; | |
10592 | ||
10593 | /* | |
10594 | * Do not allow to attach to a group in a different task | |
10595 | * or CPU context. If we're moving SW events, we'll fix | |
10596 | * this up later, so allow that. | |
10597 | */ | |
10598 | if (!move_group && group_leader->ctx != ctx) | |
10599 | goto err_context; | |
b04243ef | 10600 | |
3b6f9e5c PM |
10601 | /* |
10602 | * Only a group leader can be exclusive or pinned | |
10603 | */ | |
0d48696f | 10604 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 10605 | goto err_context; |
ac9721f3 PZ |
10606 | } |
10607 | ||
10608 | if (output_event) { | |
10609 | err = perf_event_set_output(event, output_event); | |
10610 | if (err) | |
c3f00c70 | 10611 | goto err_context; |
ac9721f3 | 10612 | } |
0793a61d | 10613 | |
a21b0b35 YD |
10614 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
10615 | f_flags); | |
ea635c64 AV |
10616 | if (IS_ERR(event_file)) { |
10617 | err = PTR_ERR(event_file); | |
201c2f85 | 10618 | event_file = NULL; |
c3f00c70 | 10619 | goto err_context; |
ea635c64 | 10620 | } |
9b51f66d | 10621 | |
b04243ef | 10622 | if (move_group) { |
321027c1 PZ |
10623 | gctx = __perf_event_ctx_lock_double(group_leader, ctx); |
10624 | ||
84c4e620 PZ |
10625 | if (gctx->task == TASK_TOMBSTONE) { |
10626 | err = -ESRCH; | |
10627 | goto err_locked; | |
10628 | } | |
321027c1 PZ |
10629 | |
10630 | /* | |
10631 | * Check if we raced against another sys_perf_event_open() call | |
10632 | * moving the software group underneath us. | |
10633 | */ | |
10634 | if (!(group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) { | |
10635 | /* | |
10636 | * If someone moved the group out from under us, check | |
10637 | * if this new event wound up on the same ctx, if so | |
10638 | * its the regular !move_group case, otherwise fail. | |
10639 | */ | |
10640 | if (gctx != ctx) { | |
10641 | err = -EINVAL; | |
10642 | goto err_locked; | |
10643 | } else { | |
10644 | perf_event_ctx_unlock(group_leader, gctx); | |
10645 | move_group = 0; | |
10646 | } | |
10647 | } | |
f55fc2a5 PZ |
10648 | } else { |
10649 | mutex_lock(&ctx->mutex); | |
10650 | } | |
10651 | ||
84c4e620 PZ |
10652 | if (ctx->task == TASK_TOMBSTONE) { |
10653 | err = -ESRCH; | |
10654 | goto err_locked; | |
10655 | } | |
10656 | ||
a723968c PZ |
10657 | if (!perf_event_validate_size(event)) { |
10658 | err = -E2BIG; | |
10659 | goto err_locked; | |
10660 | } | |
10661 | ||
a63fbed7 TG |
10662 | if (!task) { |
10663 | /* | |
10664 | * Check if the @cpu we're creating an event for is online. | |
10665 | * | |
10666 | * We use the perf_cpu_context::ctx::mutex to serialize against | |
10667 | * the hotplug notifiers. See perf_event_{init,exit}_cpu(). | |
10668 | */ | |
10669 | struct perf_cpu_context *cpuctx = | |
10670 | container_of(ctx, struct perf_cpu_context, ctx); | |
10671 | ||
10672 | if (!cpuctx->online) { | |
10673 | err = -ENODEV; | |
10674 | goto err_locked; | |
10675 | } | |
10676 | } | |
10677 | ||
10678 | ||
f55fc2a5 PZ |
10679 | /* |
10680 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
10681 | * because we need to serialize with concurrent event creation. | |
10682 | */ | |
10683 | if (!exclusive_event_installable(event, ctx)) { | |
10684 | /* exclusive and group stuff are assumed mutually exclusive */ | |
10685 | WARN_ON_ONCE(move_group); | |
f63a8daa | 10686 | |
f55fc2a5 PZ |
10687 | err = -EBUSY; |
10688 | goto err_locked; | |
10689 | } | |
f63a8daa | 10690 | |
f55fc2a5 PZ |
10691 | WARN_ON_ONCE(ctx->parent_ctx); |
10692 | ||
79c9ce57 PZ |
10693 | /* |
10694 | * This is the point on no return; we cannot fail hereafter. This is | |
10695 | * where we start modifying current state. | |
10696 | */ | |
10697 | ||
f55fc2a5 | 10698 | if (move_group) { |
f63a8daa PZ |
10699 | /* |
10700 | * See perf_event_ctx_lock() for comments on the details | |
10701 | * of swizzling perf_event::ctx. | |
10702 | */ | |
45a0e07a | 10703 | perf_remove_from_context(group_leader, 0); |
279b5165 | 10704 | put_ctx(gctx); |
0231bb53 | 10705 | |
edb39592 | 10706 | for_each_sibling_event(sibling, group_leader) { |
45a0e07a | 10707 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
10708 | put_ctx(gctx); |
10709 | } | |
b04243ef | 10710 | |
f63a8daa PZ |
10711 | /* |
10712 | * Wait for everybody to stop referencing the events through | |
10713 | * the old lists, before installing it on new lists. | |
10714 | */ | |
0cda4c02 | 10715 | synchronize_rcu(); |
f63a8daa | 10716 | |
8f95b435 PZI |
10717 | /* |
10718 | * Install the group siblings before the group leader. | |
10719 | * | |
10720 | * Because a group leader will try and install the entire group | |
10721 | * (through the sibling list, which is still in-tact), we can | |
10722 | * end up with siblings installed in the wrong context. | |
10723 | * | |
10724 | * By installing siblings first we NO-OP because they're not | |
10725 | * reachable through the group lists. | |
10726 | */ | |
edb39592 | 10727 | for_each_sibling_event(sibling, group_leader) { |
8f95b435 | 10728 | perf_event__state_init(sibling); |
9fc81d87 | 10729 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
10730 | get_ctx(ctx); |
10731 | } | |
8f95b435 PZI |
10732 | |
10733 | /* | |
10734 | * Removing from the context ends up with disabled | |
10735 | * event. What we want here is event in the initial | |
10736 | * startup state, ready to be add into new context. | |
10737 | */ | |
10738 | perf_event__state_init(group_leader); | |
10739 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
10740 | get_ctx(ctx); | |
bed5b25a AS |
10741 | } |
10742 | ||
f73e22ab PZ |
10743 | /* |
10744 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
10745 | * that we're serialized against further additions and before | |
10746 | * perf_install_in_context() which is the point the event is active and | |
10747 | * can use these values. | |
10748 | */ | |
10749 | perf_event__header_size(event); | |
10750 | perf_event__id_header_size(event); | |
10751 | ||
78cd2c74 PZ |
10752 | event->owner = current; |
10753 | ||
e2d37cd2 | 10754 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 10755 | perf_unpin_context(ctx); |
f63a8daa | 10756 | |
f55fc2a5 | 10757 | if (move_group) |
321027c1 | 10758 | perf_event_ctx_unlock(group_leader, gctx); |
d859e29f | 10759 | mutex_unlock(&ctx->mutex); |
9b51f66d | 10760 | |
79c9ce57 PZ |
10761 | if (task) { |
10762 | mutex_unlock(&task->signal->cred_guard_mutex); | |
10763 | put_task_struct(task); | |
10764 | } | |
10765 | ||
cdd6c482 IM |
10766 | mutex_lock(¤t->perf_event_mutex); |
10767 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
10768 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 10769 | |
8a49542c PZ |
10770 | /* |
10771 | * Drop the reference on the group_event after placing the | |
10772 | * new event on the sibling_list. This ensures destruction | |
10773 | * of the group leader will find the pointer to itself in | |
10774 | * perf_group_detach(). | |
10775 | */ | |
2903ff01 | 10776 | fdput(group); |
ea635c64 AV |
10777 | fd_install(event_fd, event_file); |
10778 | return event_fd; | |
0793a61d | 10779 | |
f55fc2a5 PZ |
10780 | err_locked: |
10781 | if (move_group) | |
321027c1 | 10782 | perf_event_ctx_unlock(group_leader, gctx); |
f55fc2a5 PZ |
10783 | mutex_unlock(&ctx->mutex); |
10784 | /* err_file: */ | |
10785 | fput(event_file); | |
c3f00c70 | 10786 | err_context: |
fe4b04fa | 10787 | perf_unpin_context(ctx); |
ea635c64 | 10788 | put_ctx(ctx); |
c6be5a5c | 10789 | err_alloc: |
13005627 PZ |
10790 | /* |
10791 | * If event_file is set, the fput() above will have called ->release() | |
10792 | * and that will take care of freeing the event. | |
10793 | */ | |
10794 | if (!event_file) | |
10795 | free_event(event); | |
79c9ce57 PZ |
10796 | err_cred: |
10797 | if (task) | |
10798 | mutex_unlock(&task->signal->cred_guard_mutex); | |
1f4ee503 | 10799 | err_task: |
e7d0bc04 PZ |
10800 | if (task) |
10801 | put_task_struct(task); | |
89a1e187 | 10802 | err_group_fd: |
2903ff01 | 10803 | fdput(group); |
ea635c64 AV |
10804 | err_fd: |
10805 | put_unused_fd(event_fd); | |
dc86cabe | 10806 | return err; |
0793a61d TG |
10807 | } |
10808 | ||
fb0459d7 AV |
10809 | /** |
10810 | * perf_event_create_kernel_counter | |
10811 | * | |
10812 | * @attr: attributes of the counter to create | |
10813 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 10814 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
10815 | */ |
10816 | struct perf_event * | |
10817 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 10818 | struct task_struct *task, |
4dc0da86 AK |
10819 | perf_overflow_handler_t overflow_handler, |
10820 | void *context) | |
fb0459d7 | 10821 | { |
fb0459d7 | 10822 | struct perf_event_context *ctx; |
c3f00c70 | 10823 | struct perf_event *event; |
fb0459d7 | 10824 | int err; |
d859e29f | 10825 | |
fb0459d7 AV |
10826 | /* |
10827 | * Get the target context (task or percpu): | |
10828 | */ | |
d859e29f | 10829 | |
4dc0da86 | 10830 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 10831 | overflow_handler, context, -1); |
c3f00c70 PZ |
10832 | if (IS_ERR(event)) { |
10833 | err = PTR_ERR(event); | |
10834 | goto err; | |
10835 | } | |
d859e29f | 10836 | |
f8697762 | 10837 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 10838 | event->owner = TASK_TOMBSTONE; |
f8697762 | 10839 | |
4af57ef2 | 10840 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
10841 | if (IS_ERR(ctx)) { |
10842 | err = PTR_ERR(ctx); | |
c3f00c70 | 10843 | goto err_free; |
d859e29f | 10844 | } |
fb0459d7 | 10845 | |
fb0459d7 AV |
10846 | WARN_ON_ONCE(ctx->parent_ctx); |
10847 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
10848 | if (ctx->task == TASK_TOMBSTONE) { |
10849 | err = -ESRCH; | |
10850 | goto err_unlock; | |
10851 | } | |
10852 | ||
a63fbed7 TG |
10853 | if (!task) { |
10854 | /* | |
10855 | * Check if the @cpu we're creating an event for is online. | |
10856 | * | |
10857 | * We use the perf_cpu_context::ctx::mutex to serialize against | |
10858 | * the hotplug notifiers. See perf_event_{init,exit}_cpu(). | |
10859 | */ | |
10860 | struct perf_cpu_context *cpuctx = | |
10861 | container_of(ctx, struct perf_cpu_context, ctx); | |
10862 | if (!cpuctx->online) { | |
10863 | err = -ENODEV; | |
10864 | goto err_unlock; | |
10865 | } | |
10866 | } | |
10867 | ||
bed5b25a | 10868 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 10869 | err = -EBUSY; |
84c4e620 | 10870 | goto err_unlock; |
bed5b25a AS |
10871 | } |
10872 | ||
fb0459d7 | 10873 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 10874 | perf_unpin_context(ctx); |
fb0459d7 AV |
10875 | mutex_unlock(&ctx->mutex); |
10876 | ||
fb0459d7 AV |
10877 | return event; |
10878 | ||
84c4e620 PZ |
10879 | err_unlock: |
10880 | mutex_unlock(&ctx->mutex); | |
10881 | perf_unpin_context(ctx); | |
10882 | put_ctx(ctx); | |
c3f00c70 PZ |
10883 | err_free: |
10884 | free_event(event); | |
10885 | err: | |
c6567f64 | 10886 | return ERR_PTR(err); |
9b51f66d | 10887 | } |
fb0459d7 | 10888 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 10889 | |
0cda4c02 YZ |
10890 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
10891 | { | |
10892 | struct perf_event_context *src_ctx; | |
10893 | struct perf_event_context *dst_ctx; | |
10894 | struct perf_event *event, *tmp; | |
10895 | LIST_HEAD(events); | |
10896 | ||
10897 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
10898 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
10899 | ||
f63a8daa PZ |
10900 | /* |
10901 | * See perf_event_ctx_lock() for comments on the details | |
10902 | * of swizzling perf_event::ctx. | |
10903 | */ | |
10904 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
10905 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
10906 | event_entry) { | |
45a0e07a | 10907 | perf_remove_from_context(event, 0); |
9a545de0 | 10908 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 10909 | put_ctx(src_ctx); |
9886167d | 10910 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 10911 | } |
0cda4c02 | 10912 | |
8f95b435 PZI |
10913 | /* |
10914 | * Wait for the events to quiesce before re-instating them. | |
10915 | */ | |
0cda4c02 YZ |
10916 | synchronize_rcu(); |
10917 | ||
8f95b435 PZI |
10918 | /* |
10919 | * Re-instate events in 2 passes. | |
10920 | * | |
10921 | * Skip over group leaders and only install siblings on this first | |
10922 | * pass, siblings will not get enabled without a leader, however a | |
10923 | * leader will enable its siblings, even if those are still on the old | |
10924 | * context. | |
10925 | */ | |
10926 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
10927 | if (event->group_leader == event) | |
10928 | continue; | |
10929 | ||
10930 | list_del(&event->migrate_entry); | |
10931 | if (event->state >= PERF_EVENT_STATE_OFF) | |
10932 | event->state = PERF_EVENT_STATE_INACTIVE; | |
10933 | account_event_cpu(event, dst_cpu); | |
10934 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
10935 | get_ctx(dst_ctx); | |
10936 | } | |
10937 | ||
10938 | /* | |
10939 | * Once all the siblings are setup properly, install the group leaders | |
10940 | * to make it go. | |
10941 | */ | |
9886167d PZ |
10942 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
10943 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
10944 | if (event->state >= PERF_EVENT_STATE_OFF) |
10945 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 10946 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
10947 | perf_install_in_context(dst_ctx, event, dst_cpu); |
10948 | get_ctx(dst_ctx); | |
10949 | } | |
10950 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 10951 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
10952 | } |
10953 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
10954 | ||
cdd6c482 | 10955 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 10956 | struct task_struct *child) |
d859e29f | 10957 | { |
cdd6c482 | 10958 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 10959 | u64 child_val; |
d859e29f | 10960 | |
cdd6c482 IM |
10961 | if (child_event->attr.inherit_stat) |
10962 | perf_event_read_event(child_event, child); | |
38b200d6 | 10963 | |
b5e58793 | 10964 | child_val = perf_event_count(child_event); |
d859e29f PM |
10965 | |
10966 | /* | |
10967 | * Add back the child's count to the parent's count: | |
10968 | */ | |
a6e6dea6 | 10969 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
10970 | atomic64_add(child_event->total_time_enabled, |
10971 | &parent_event->child_total_time_enabled); | |
10972 | atomic64_add(child_event->total_time_running, | |
10973 | &parent_event->child_total_time_running); | |
d859e29f PM |
10974 | } |
10975 | ||
9b51f66d | 10976 | static void |
8ba289b8 PZ |
10977 | perf_event_exit_event(struct perf_event *child_event, |
10978 | struct perf_event_context *child_ctx, | |
10979 | struct task_struct *child) | |
9b51f66d | 10980 | { |
8ba289b8 PZ |
10981 | struct perf_event *parent_event = child_event->parent; |
10982 | ||
1903d50c PZ |
10983 | /* |
10984 | * Do not destroy the 'original' grouping; because of the context | |
10985 | * switch optimization the original events could've ended up in a | |
10986 | * random child task. | |
10987 | * | |
10988 | * If we were to destroy the original group, all group related | |
10989 | * operations would cease to function properly after this random | |
10990 | * child dies. | |
10991 | * | |
10992 | * Do destroy all inherited groups, we don't care about those | |
10993 | * and being thorough is better. | |
10994 | */ | |
32132a3d PZ |
10995 | raw_spin_lock_irq(&child_ctx->lock); |
10996 | WARN_ON_ONCE(child_ctx->is_active); | |
10997 | ||
8ba289b8 | 10998 | if (parent_event) |
32132a3d PZ |
10999 | perf_group_detach(child_event); |
11000 | list_del_event(child_event, child_ctx); | |
0d3d73aa | 11001 | perf_event_set_state(child_event, PERF_EVENT_STATE_EXIT); /* is_event_hup() */ |
32132a3d | 11002 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 11003 | |
9b51f66d | 11004 | /* |
8ba289b8 | 11005 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 11006 | */ |
8ba289b8 | 11007 | if (!parent_event) { |
179033b3 | 11008 | perf_event_wakeup(child_event); |
8ba289b8 | 11009 | return; |
4bcf349a | 11010 | } |
8ba289b8 PZ |
11011 | /* |
11012 | * Child events can be cleaned up. | |
11013 | */ | |
11014 | ||
11015 | sync_child_event(child_event, child); | |
11016 | ||
11017 | /* | |
11018 | * Remove this event from the parent's list | |
11019 | */ | |
11020 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
11021 | mutex_lock(&parent_event->child_mutex); | |
11022 | list_del_init(&child_event->child_list); | |
11023 | mutex_unlock(&parent_event->child_mutex); | |
11024 | ||
11025 | /* | |
11026 | * Kick perf_poll() for is_event_hup(). | |
11027 | */ | |
11028 | perf_event_wakeup(parent_event); | |
11029 | free_event(child_event); | |
11030 | put_event(parent_event); | |
9b51f66d IM |
11031 | } |
11032 | ||
8dc85d54 | 11033 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 11034 | { |
211de6eb | 11035 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 11036 | struct perf_event *child_event, *next; |
63b6da39 PZ |
11037 | |
11038 | WARN_ON_ONCE(child != current); | |
9b51f66d | 11039 | |
6a3351b6 | 11040 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 11041 | if (!child_ctx) |
9b51f66d IM |
11042 | return; |
11043 | ||
ad3a37de | 11044 | /* |
6a3351b6 PZ |
11045 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
11046 | * ctx::mutex over the entire thing. This serializes against almost | |
11047 | * everything that wants to access the ctx. | |
11048 | * | |
11049 | * The exception is sys_perf_event_open() / | |
11050 | * perf_event_create_kernel_count() which does find_get_context() | |
11051 | * without ctx::mutex (it cannot because of the move_group double mutex | |
11052 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 11053 | */ |
6a3351b6 | 11054 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
11055 | |
11056 | /* | |
6a3351b6 PZ |
11057 | * In a single ctx::lock section, de-schedule the events and detach the |
11058 | * context from the task such that we cannot ever get it scheduled back | |
11059 | * in. | |
c93f7669 | 11060 | */ |
6a3351b6 | 11061 | raw_spin_lock_irq(&child_ctx->lock); |
487f05e1 | 11062 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx, EVENT_ALL); |
4a1c0f26 | 11063 | |
71a851b4 | 11064 | /* |
63b6da39 PZ |
11065 | * Now that the context is inactive, destroy the task <-> ctx relation |
11066 | * and mark the context dead. | |
71a851b4 | 11067 | */ |
63b6da39 PZ |
11068 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
11069 | put_ctx(child_ctx); /* cannot be last */ | |
11070 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
11071 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 11072 | |
211de6eb | 11073 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 11074 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 11075 | |
211de6eb PZ |
11076 | if (clone_ctx) |
11077 | put_ctx(clone_ctx); | |
4a1c0f26 | 11078 | |
9f498cc5 | 11079 | /* |
cdd6c482 IM |
11080 | * Report the task dead after unscheduling the events so that we |
11081 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
11082 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 11083 | */ |
cdd6c482 | 11084 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 11085 | |
ebf905fc | 11086 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 11087 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 11088 | |
a63eaf34 PM |
11089 | mutex_unlock(&child_ctx->mutex); |
11090 | ||
11091 | put_ctx(child_ctx); | |
9b51f66d IM |
11092 | } |
11093 | ||
8dc85d54 PZ |
11094 | /* |
11095 | * When a child task exits, feed back event values to parent events. | |
79c9ce57 PZ |
11096 | * |
11097 | * Can be called with cred_guard_mutex held when called from | |
11098 | * install_exec_creds(). | |
8dc85d54 PZ |
11099 | */ |
11100 | void perf_event_exit_task(struct task_struct *child) | |
11101 | { | |
8882135b | 11102 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
11103 | int ctxn; |
11104 | ||
8882135b PZ |
11105 | mutex_lock(&child->perf_event_mutex); |
11106 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
11107 | owner_entry) { | |
11108 | list_del_init(&event->owner_entry); | |
11109 | ||
11110 | /* | |
11111 | * Ensure the list deletion is visible before we clear | |
11112 | * the owner, closes a race against perf_release() where | |
11113 | * we need to serialize on the owner->perf_event_mutex. | |
11114 | */ | |
f47c02c0 | 11115 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
11116 | } |
11117 | mutex_unlock(&child->perf_event_mutex); | |
11118 | ||
8dc85d54 PZ |
11119 | for_each_task_context_nr(ctxn) |
11120 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
11121 | |
11122 | /* | |
11123 | * The perf_event_exit_task_context calls perf_event_task | |
11124 | * with child's task_ctx, which generates EXIT events for | |
11125 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
11126 | * At this point we need to send EXIT events to cpu contexts. | |
11127 | */ | |
11128 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
11129 | } |
11130 | ||
889ff015 FW |
11131 | static void perf_free_event(struct perf_event *event, |
11132 | struct perf_event_context *ctx) | |
11133 | { | |
11134 | struct perf_event *parent = event->parent; | |
11135 | ||
11136 | if (WARN_ON_ONCE(!parent)) | |
11137 | return; | |
11138 | ||
11139 | mutex_lock(&parent->child_mutex); | |
11140 | list_del_init(&event->child_list); | |
11141 | mutex_unlock(&parent->child_mutex); | |
11142 | ||
a6fa941d | 11143 | put_event(parent); |
889ff015 | 11144 | |
652884fe | 11145 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 11146 | perf_group_detach(event); |
889ff015 | 11147 | list_del_event(event, ctx); |
652884fe | 11148 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
11149 | free_event(event); |
11150 | } | |
11151 | ||
bbbee908 | 11152 | /* |
652884fe | 11153 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 11154 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
11155 | * |
11156 | * Not all locks are strictly required, but take them anyway to be nice and | |
11157 | * help out with the lockdep assertions. | |
bbbee908 | 11158 | */ |
cdd6c482 | 11159 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 11160 | { |
8dc85d54 | 11161 | struct perf_event_context *ctx; |
cdd6c482 | 11162 | struct perf_event *event, *tmp; |
8dc85d54 | 11163 | int ctxn; |
bbbee908 | 11164 | |
8dc85d54 PZ |
11165 | for_each_task_context_nr(ctxn) { |
11166 | ctx = task->perf_event_ctxp[ctxn]; | |
11167 | if (!ctx) | |
11168 | continue; | |
bbbee908 | 11169 | |
8dc85d54 | 11170 | mutex_lock(&ctx->mutex); |
e552a838 PZ |
11171 | raw_spin_lock_irq(&ctx->lock); |
11172 | /* | |
11173 | * Destroy the task <-> ctx relation and mark the context dead. | |
11174 | * | |
11175 | * This is important because even though the task hasn't been | |
11176 | * exposed yet the context has been (through child_list). | |
11177 | */ | |
11178 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], NULL); | |
11179 | WRITE_ONCE(ctx->task, TASK_TOMBSTONE); | |
11180 | put_task_struct(task); /* cannot be last */ | |
11181 | raw_spin_unlock_irq(&ctx->lock); | |
bbbee908 | 11182 | |
15121c78 | 11183 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) |
8dc85d54 | 11184 | perf_free_event(event, ctx); |
bbbee908 | 11185 | |
8dc85d54 | 11186 | mutex_unlock(&ctx->mutex); |
8dc85d54 PZ |
11187 | put_ctx(ctx); |
11188 | } | |
889ff015 FW |
11189 | } |
11190 | ||
4e231c79 PZ |
11191 | void perf_event_delayed_put(struct task_struct *task) |
11192 | { | |
11193 | int ctxn; | |
11194 | ||
11195 | for_each_task_context_nr(ctxn) | |
11196 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
11197 | } | |
11198 | ||
e03e7ee3 | 11199 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 11200 | { |
e03e7ee3 | 11201 | struct file *file; |
ffe8690c | 11202 | |
e03e7ee3 AS |
11203 | file = fget_raw(fd); |
11204 | if (!file) | |
11205 | return ERR_PTR(-EBADF); | |
ffe8690c | 11206 | |
e03e7ee3 AS |
11207 | if (file->f_op != &perf_fops) { |
11208 | fput(file); | |
11209 | return ERR_PTR(-EBADF); | |
11210 | } | |
ffe8690c | 11211 | |
e03e7ee3 | 11212 | return file; |
ffe8690c KX |
11213 | } |
11214 | ||
f8d959a5 YS |
11215 | const struct perf_event *perf_get_event(struct file *file) |
11216 | { | |
11217 | if (file->f_op != &perf_fops) | |
11218 | return ERR_PTR(-EINVAL); | |
11219 | ||
11220 | return file->private_data; | |
11221 | } | |
11222 | ||
ffe8690c KX |
11223 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) |
11224 | { | |
11225 | if (!event) | |
11226 | return ERR_PTR(-EINVAL); | |
11227 | ||
11228 | return &event->attr; | |
11229 | } | |
11230 | ||
97dee4f3 | 11231 | /* |
d8a8cfc7 PZ |
11232 | * Inherit a event from parent task to child task. |
11233 | * | |
11234 | * Returns: | |
11235 | * - valid pointer on success | |
11236 | * - NULL for orphaned events | |
11237 | * - IS_ERR() on error | |
97dee4f3 PZ |
11238 | */ |
11239 | static struct perf_event * | |
11240 | inherit_event(struct perf_event *parent_event, | |
11241 | struct task_struct *parent, | |
11242 | struct perf_event_context *parent_ctx, | |
11243 | struct task_struct *child, | |
11244 | struct perf_event *group_leader, | |
11245 | struct perf_event_context *child_ctx) | |
11246 | { | |
8ca2bd41 | 11247 | enum perf_event_state parent_state = parent_event->state; |
97dee4f3 | 11248 | struct perf_event *child_event; |
cee010ec | 11249 | unsigned long flags; |
97dee4f3 PZ |
11250 | |
11251 | /* | |
11252 | * Instead of creating recursive hierarchies of events, | |
11253 | * we link inherited events back to the original parent, | |
11254 | * which has a filp for sure, which we use as the reference | |
11255 | * count: | |
11256 | */ | |
11257 | if (parent_event->parent) | |
11258 | parent_event = parent_event->parent; | |
11259 | ||
11260 | child_event = perf_event_alloc(&parent_event->attr, | |
11261 | parent_event->cpu, | |
d580ff86 | 11262 | child, |
97dee4f3 | 11263 | group_leader, parent_event, |
79dff51e | 11264 | NULL, NULL, -1); |
97dee4f3 PZ |
11265 | if (IS_ERR(child_event)) |
11266 | return child_event; | |
a6fa941d | 11267 | |
313ccb96 JO |
11268 | |
11269 | if ((child_event->attach_state & PERF_ATTACH_TASK_DATA) && | |
11270 | !child_ctx->task_ctx_data) { | |
11271 | struct pmu *pmu = child_event->pmu; | |
11272 | ||
11273 | child_ctx->task_ctx_data = kzalloc(pmu->task_ctx_size, | |
11274 | GFP_KERNEL); | |
11275 | if (!child_ctx->task_ctx_data) { | |
11276 | free_event(child_event); | |
11277 | return NULL; | |
11278 | } | |
11279 | } | |
11280 | ||
c6e5b732 PZ |
11281 | /* |
11282 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
11283 | * must be under the same lock in order to serialize against | |
11284 | * perf_event_release_kernel(), such that either we must observe | |
11285 | * is_orphaned_event() or they will observe us on the child_list. | |
11286 | */ | |
11287 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
11288 | if (is_orphaned_event(parent_event) || |
11289 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 11290 | mutex_unlock(&parent_event->child_mutex); |
313ccb96 | 11291 | /* task_ctx_data is freed with child_ctx */ |
a6fa941d AV |
11292 | free_event(child_event); |
11293 | return NULL; | |
11294 | } | |
11295 | ||
97dee4f3 PZ |
11296 | get_ctx(child_ctx); |
11297 | ||
11298 | /* | |
11299 | * Make the child state follow the state of the parent event, | |
11300 | * not its attr.disabled bit. We hold the parent's mutex, | |
11301 | * so we won't race with perf_event_{en, dis}able_family. | |
11302 | */ | |
1929def9 | 11303 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
11304 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
11305 | else | |
11306 | child_event->state = PERF_EVENT_STATE_OFF; | |
11307 | ||
11308 | if (parent_event->attr.freq) { | |
11309 | u64 sample_period = parent_event->hw.sample_period; | |
11310 | struct hw_perf_event *hwc = &child_event->hw; | |
11311 | ||
11312 | hwc->sample_period = sample_period; | |
11313 | hwc->last_period = sample_period; | |
11314 | ||
11315 | local64_set(&hwc->period_left, sample_period); | |
11316 | } | |
11317 | ||
11318 | child_event->ctx = child_ctx; | |
11319 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
11320 | child_event->overflow_handler_context |
11321 | = parent_event->overflow_handler_context; | |
97dee4f3 | 11322 | |
614b6780 TG |
11323 | /* |
11324 | * Precalculate sample_data sizes | |
11325 | */ | |
11326 | perf_event__header_size(child_event); | |
6844c09d | 11327 | perf_event__id_header_size(child_event); |
614b6780 | 11328 | |
97dee4f3 PZ |
11329 | /* |
11330 | * Link it up in the child's context: | |
11331 | */ | |
cee010ec | 11332 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 11333 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 11334 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 11335 | |
97dee4f3 PZ |
11336 | /* |
11337 | * Link this into the parent event's child list | |
11338 | */ | |
97dee4f3 PZ |
11339 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
11340 | mutex_unlock(&parent_event->child_mutex); | |
11341 | ||
11342 | return child_event; | |
11343 | } | |
11344 | ||
d8a8cfc7 PZ |
11345 | /* |
11346 | * Inherits an event group. | |
11347 | * | |
11348 | * This will quietly suppress orphaned events; !inherit_event() is not an error. | |
11349 | * This matches with perf_event_release_kernel() removing all child events. | |
11350 | * | |
11351 | * Returns: | |
11352 | * - 0 on success | |
11353 | * - <0 on error | |
11354 | */ | |
97dee4f3 PZ |
11355 | static int inherit_group(struct perf_event *parent_event, |
11356 | struct task_struct *parent, | |
11357 | struct perf_event_context *parent_ctx, | |
11358 | struct task_struct *child, | |
11359 | struct perf_event_context *child_ctx) | |
11360 | { | |
11361 | struct perf_event *leader; | |
11362 | struct perf_event *sub; | |
11363 | struct perf_event *child_ctr; | |
11364 | ||
11365 | leader = inherit_event(parent_event, parent, parent_ctx, | |
11366 | child, NULL, child_ctx); | |
11367 | if (IS_ERR(leader)) | |
11368 | return PTR_ERR(leader); | |
d8a8cfc7 PZ |
11369 | /* |
11370 | * @leader can be NULL here because of is_orphaned_event(). In this | |
11371 | * case inherit_event() will create individual events, similar to what | |
11372 | * perf_group_detach() would do anyway. | |
11373 | */ | |
edb39592 | 11374 | for_each_sibling_event(sub, parent_event) { |
97dee4f3 PZ |
11375 | child_ctr = inherit_event(sub, parent, parent_ctx, |
11376 | child, leader, child_ctx); | |
11377 | if (IS_ERR(child_ctr)) | |
11378 | return PTR_ERR(child_ctr); | |
11379 | } | |
11380 | return 0; | |
889ff015 FW |
11381 | } |
11382 | ||
d8a8cfc7 PZ |
11383 | /* |
11384 | * Creates the child task context and tries to inherit the event-group. | |
11385 | * | |
11386 | * Clears @inherited_all on !attr.inherited or error. Note that we'll leave | |
11387 | * inherited_all set when we 'fail' to inherit an orphaned event; this is | |
11388 | * consistent with perf_event_release_kernel() removing all child events. | |
11389 | * | |
11390 | * Returns: | |
11391 | * - 0 on success | |
11392 | * - <0 on error | |
11393 | */ | |
889ff015 FW |
11394 | static int |
11395 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
11396 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 11397 | struct task_struct *child, int ctxn, |
889ff015 FW |
11398 | int *inherited_all) |
11399 | { | |
11400 | int ret; | |
8dc85d54 | 11401 | struct perf_event_context *child_ctx; |
889ff015 FW |
11402 | |
11403 | if (!event->attr.inherit) { | |
11404 | *inherited_all = 0; | |
11405 | return 0; | |
bbbee908 PZ |
11406 | } |
11407 | ||
fe4b04fa | 11408 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
11409 | if (!child_ctx) { |
11410 | /* | |
11411 | * This is executed from the parent task context, so | |
11412 | * inherit events that have been marked for cloning. | |
11413 | * First allocate and initialize a context for the | |
11414 | * child. | |
11415 | */ | |
734df5ab | 11416 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
11417 | if (!child_ctx) |
11418 | return -ENOMEM; | |
bbbee908 | 11419 | |
8dc85d54 | 11420 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
11421 | } |
11422 | ||
11423 | ret = inherit_group(event, parent, parent_ctx, | |
11424 | child, child_ctx); | |
11425 | ||
11426 | if (ret) | |
11427 | *inherited_all = 0; | |
11428 | ||
11429 | return ret; | |
bbbee908 PZ |
11430 | } |
11431 | ||
9b51f66d | 11432 | /* |
cdd6c482 | 11433 | * Initialize the perf_event context in task_struct |
9b51f66d | 11434 | */ |
985c8dcb | 11435 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 11436 | { |
889ff015 | 11437 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
11438 | struct perf_event_context *cloned_ctx; |
11439 | struct perf_event *event; | |
9b51f66d | 11440 | struct task_struct *parent = current; |
564c2b21 | 11441 | int inherited_all = 1; |
dddd3379 | 11442 | unsigned long flags; |
6ab423e0 | 11443 | int ret = 0; |
9b51f66d | 11444 | |
8dc85d54 | 11445 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
11446 | return 0; |
11447 | ||
ad3a37de | 11448 | /* |
25346b93 PM |
11449 | * If the parent's context is a clone, pin it so it won't get |
11450 | * swapped under us. | |
ad3a37de | 11451 | */ |
8dc85d54 | 11452 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
11453 | if (!parent_ctx) |
11454 | return 0; | |
25346b93 | 11455 | |
ad3a37de PM |
11456 | /* |
11457 | * No need to check if parent_ctx != NULL here; since we saw | |
11458 | * it non-NULL earlier, the only reason for it to become NULL | |
11459 | * is if we exit, and since we're currently in the middle of | |
11460 | * a fork we can't be exiting at the same time. | |
11461 | */ | |
ad3a37de | 11462 | |
9b51f66d IM |
11463 | /* |
11464 | * Lock the parent list. No need to lock the child - not PID | |
11465 | * hashed yet and not running, so nobody can access it. | |
11466 | */ | |
d859e29f | 11467 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
11468 | |
11469 | /* | |
11470 | * We dont have to disable NMIs - we are only looking at | |
11471 | * the list, not manipulating it: | |
11472 | */ | |
6e6804d2 | 11473 | perf_event_groups_for_each(event, &parent_ctx->pinned_groups) { |
8dc85d54 PZ |
11474 | ret = inherit_task_group(event, parent, parent_ctx, |
11475 | child, ctxn, &inherited_all); | |
889ff015 | 11476 | if (ret) |
e7cc4865 | 11477 | goto out_unlock; |
889ff015 | 11478 | } |
b93f7978 | 11479 | |
dddd3379 TG |
11480 | /* |
11481 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
11482 | * to allocations, but we need to prevent rotation because | |
11483 | * rotate_ctx() will change the list from interrupt context. | |
11484 | */ | |
11485 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
11486 | parent_ctx->rotate_disable = 1; | |
11487 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
11488 | ||
6e6804d2 | 11489 | perf_event_groups_for_each(event, &parent_ctx->flexible_groups) { |
8dc85d54 PZ |
11490 | ret = inherit_task_group(event, parent, parent_ctx, |
11491 | child, ctxn, &inherited_all); | |
889ff015 | 11492 | if (ret) |
e7cc4865 | 11493 | goto out_unlock; |
564c2b21 PM |
11494 | } |
11495 | ||
dddd3379 TG |
11496 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
11497 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 11498 | |
8dc85d54 | 11499 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 11500 | |
05cbaa28 | 11501 | if (child_ctx && inherited_all) { |
564c2b21 PM |
11502 | /* |
11503 | * Mark the child context as a clone of the parent | |
11504 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
11505 | * |
11506 | * Note that if the parent is a clone, the holding of | |
11507 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 11508 | */ |
c5ed5145 | 11509 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
11510 | if (cloned_ctx) { |
11511 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 11512 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
11513 | } else { |
11514 | child_ctx->parent_ctx = parent_ctx; | |
11515 | child_ctx->parent_gen = parent_ctx->generation; | |
11516 | } | |
11517 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
11518 | } |
11519 | ||
c5ed5145 | 11520 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
e7cc4865 | 11521 | out_unlock: |
d859e29f | 11522 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 11523 | |
25346b93 | 11524 | perf_unpin_context(parent_ctx); |
fe4b04fa | 11525 | put_ctx(parent_ctx); |
ad3a37de | 11526 | |
6ab423e0 | 11527 | return ret; |
9b51f66d IM |
11528 | } |
11529 | ||
8dc85d54 PZ |
11530 | /* |
11531 | * Initialize the perf_event context in task_struct | |
11532 | */ | |
11533 | int perf_event_init_task(struct task_struct *child) | |
11534 | { | |
11535 | int ctxn, ret; | |
11536 | ||
8550d7cb ON |
11537 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
11538 | mutex_init(&child->perf_event_mutex); | |
11539 | INIT_LIST_HEAD(&child->perf_event_list); | |
11540 | ||
8dc85d54 PZ |
11541 | for_each_task_context_nr(ctxn) { |
11542 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
11543 | if (ret) { |
11544 | perf_event_free_task(child); | |
8dc85d54 | 11545 | return ret; |
6c72e350 | 11546 | } |
8dc85d54 PZ |
11547 | } |
11548 | ||
11549 | return 0; | |
11550 | } | |
11551 | ||
220b140b PM |
11552 | static void __init perf_event_init_all_cpus(void) |
11553 | { | |
b28ab83c | 11554 | struct swevent_htable *swhash; |
220b140b | 11555 | int cpu; |
220b140b | 11556 | |
a63fbed7 TG |
11557 | zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL); |
11558 | ||
220b140b | 11559 | for_each_possible_cpu(cpu) { |
b28ab83c PZ |
11560 | swhash = &per_cpu(swevent_htable, cpu); |
11561 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 11562 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
f2fb6bef KL |
11563 | |
11564 | INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu)); | |
11565 | raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu)); | |
e48c1788 | 11566 | |
058fe1c0 DCC |
11567 | #ifdef CONFIG_CGROUP_PERF |
11568 | INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list, cpu)); | |
11569 | #endif | |
e48c1788 | 11570 | INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu)); |
220b140b PM |
11571 | } |
11572 | } | |
11573 | ||
a63fbed7 | 11574 | void perf_swevent_init_cpu(unsigned int cpu) |
0793a61d | 11575 | { |
108b02cf | 11576 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 11577 | |
b28ab83c | 11578 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 11579 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
11580 | struct swevent_hlist *hlist; |
11581 | ||
b28ab83c PZ |
11582 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
11583 | WARN_ON(!hlist); | |
11584 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 11585 | } |
b28ab83c | 11586 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
11587 | } |
11588 | ||
2965faa5 | 11589 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 11590 | static void __perf_event_exit_context(void *__info) |
0793a61d | 11591 | { |
108b02cf | 11592 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
11593 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
11594 | struct perf_event *event; | |
0793a61d | 11595 | |
fae3fde6 | 11596 | raw_spin_lock(&ctx->lock); |
0ee098c9 | 11597 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
fae3fde6 | 11598 | list_for_each_entry(event, &ctx->event_list, event_entry) |
45a0e07a | 11599 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 11600 | raw_spin_unlock(&ctx->lock); |
0793a61d | 11601 | } |
108b02cf PZ |
11602 | |
11603 | static void perf_event_exit_cpu_context(int cpu) | |
11604 | { | |
a63fbed7 | 11605 | struct perf_cpu_context *cpuctx; |
108b02cf PZ |
11606 | struct perf_event_context *ctx; |
11607 | struct pmu *pmu; | |
108b02cf | 11608 | |
a63fbed7 TG |
11609 | mutex_lock(&pmus_lock); |
11610 | list_for_each_entry(pmu, &pmus, entry) { | |
11611 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
11612 | ctx = &cpuctx->ctx; | |
108b02cf PZ |
11613 | |
11614 | mutex_lock(&ctx->mutex); | |
11615 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
a63fbed7 | 11616 | cpuctx->online = 0; |
108b02cf PZ |
11617 | mutex_unlock(&ctx->mutex); |
11618 | } | |
a63fbed7 TG |
11619 | cpumask_clear_cpu(cpu, perf_online_mask); |
11620 | mutex_unlock(&pmus_lock); | |
108b02cf | 11621 | } |
00e16c3d TG |
11622 | #else |
11623 | ||
11624 | static void perf_event_exit_cpu_context(int cpu) { } | |
11625 | ||
11626 | #endif | |
108b02cf | 11627 | |
a63fbed7 TG |
11628 | int perf_event_init_cpu(unsigned int cpu) |
11629 | { | |
11630 | struct perf_cpu_context *cpuctx; | |
11631 | struct perf_event_context *ctx; | |
11632 | struct pmu *pmu; | |
11633 | ||
11634 | perf_swevent_init_cpu(cpu); | |
11635 | ||
11636 | mutex_lock(&pmus_lock); | |
11637 | cpumask_set_cpu(cpu, perf_online_mask); | |
11638 | list_for_each_entry(pmu, &pmus, entry) { | |
11639 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
11640 | ctx = &cpuctx->ctx; | |
11641 | ||
11642 | mutex_lock(&ctx->mutex); | |
11643 | cpuctx->online = 1; | |
11644 | mutex_unlock(&ctx->mutex); | |
11645 | } | |
11646 | mutex_unlock(&pmus_lock); | |
11647 | ||
11648 | return 0; | |
11649 | } | |
11650 | ||
00e16c3d | 11651 | int perf_event_exit_cpu(unsigned int cpu) |
0793a61d | 11652 | { |
e3703f8c | 11653 | perf_event_exit_cpu_context(cpu); |
00e16c3d | 11654 | return 0; |
0793a61d | 11655 | } |
0793a61d | 11656 | |
c277443c PZ |
11657 | static int |
11658 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
11659 | { | |
11660 | int cpu; | |
11661 | ||
11662 | for_each_online_cpu(cpu) | |
11663 | perf_event_exit_cpu(cpu); | |
11664 | ||
11665 | return NOTIFY_OK; | |
11666 | } | |
11667 | ||
11668 | /* | |
11669 | * Run the perf reboot notifier at the very last possible moment so that | |
11670 | * the generic watchdog code runs as long as possible. | |
11671 | */ | |
11672 | static struct notifier_block perf_reboot_notifier = { | |
11673 | .notifier_call = perf_reboot, | |
11674 | .priority = INT_MIN, | |
11675 | }; | |
11676 | ||
cdd6c482 | 11677 | void __init perf_event_init(void) |
0793a61d | 11678 | { |
3c502e7a JW |
11679 | int ret; |
11680 | ||
2e80a82a PZ |
11681 | idr_init(&pmu_idr); |
11682 | ||
220b140b | 11683 | perf_event_init_all_cpus(); |
b0a873eb | 11684 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
11685 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
11686 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
11687 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb | 11688 | perf_tp_register(); |
00e16c3d | 11689 | perf_event_init_cpu(smp_processor_id()); |
c277443c | 11690 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
11691 | |
11692 | ret = init_hw_breakpoint(); | |
11693 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 11694 | |
b01c3a00 JO |
11695 | /* |
11696 | * Build time assertion that we keep the data_head at the intended | |
11697 | * location. IOW, validation we got the __reserved[] size right. | |
11698 | */ | |
11699 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
11700 | != 1024); | |
0793a61d | 11701 | } |
abe43400 | 11702 | |
fd979c01 CS |
11703 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
11704 | char *page) | |
11705 | { | |
11706 | struct perf_pmu_events_attr *pmu_attr = | |
11707 | container_of(attr, struct perf_pmu_events_attr, attr); | |
11708 | ||
11709 | if (pmu_attr->event_str) | |
11710 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
11711 | ||
11712 | return 0; | |
11713 | } | |
675965b0 | 11714 | EXPORT_SYMBOL_GPL(perf_event_sysfs_show); |
fd979c01 | 11715 | |
abe43400 PZ |
11716 | static int __init perf_event_sysfs_init(void) |
11717 | { | |
11718 | struct pmu *pmu; | |
11719 | int ret; | |
11720 | ||
11721 | mutex_lock(&pmus_lock); | |
11722 | ||
11723 | ret = bus_register(&pmu_bus); | |
11724 | if (ret) | |
11725 | goto unlock; | |
11726 | ||
11727 | list_for_each_entry(pmu, &pmus, entry) { | |
11728 | if (!pmu->name || pmu->type < 0) | |
11729 | continue; | |
11730 | ||
11731 | ret = pmu_dev_alloc(pmu); | |
11732 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
11733 | } | |
11734 | pmu_bus_running = 1; | |
11735 | ret = 0; | |
11736 | ||
11737 | unlock: | |
11738 | mutex_unlock(&pmus_lock); | |
11739 | ||
11740 | return ret; | |
11741 | } | |
11742 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
11743 | |
11744 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
11745 | static struct cgroup_subsys_state * |
11746 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
11747 | { |
11748 | struct perf_cgroup *jc; | |
e5d1367f | 11749 | |
1b15d055 | 11750 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
11751 | if (!jc) |
11752 | return ERR_PTR(-ENOMEM); | |
11753 | ||
e5d1367f SE |
11754 | jc->info = alloc_percpu(struct perf_cgroup_info); |
11755 | if (!jc->info) { | |
11756 | kfree(jc); | |
11757 | return ERR_PTR(-ENOMEM); | |
11758 | } | |
11759 | ||
e5d1367f SE |
11760 | return &jc->css; |
11761 | } | |
11762 | ||
eb95419b | 11763 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 11764 | { |
eb95419b TH |
11765 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
11766 | ||
e5d1367f SE |
11767 | free_percpu(jc->info); |
11768 | kfree(jc); | |
11769 | } | |
11770 | ||
11771 | static int __perf_cgroup_move(void *info) | |
11772 | { | |
11773 | struct task_struct *task = info; | |
ddaaf4e2 | 11774 | rcu_read_lock(); |
e5d1367f | 11775 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 11776 | rcu_read_unlock(); |
e5d1367f SE |
11777 | return 0; |
11778 | } | |
11779 | ||
1f7dd3e5 | 11780 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 11781 | { |
bb9d97b6 | 11782 | struct task_struct *task; |
1f7dd3e5 | 11783 | struct cgroup_subsys_state *css; |
bb9d97b6 | 11784 | |
1f7dd3e5 | 11785 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 11786 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
11787 | } |
11788 | ||
073219e9 | 11789 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
11790 | .css_alloc = perf_cgroup_css_alloc, |
11791 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 11792 | .attach = perf_cgroup_attach, |
968ebff1 TH |
11793 | /* |
11794 | * Implicitly enable on dfl hierarchy so that perf events can | |
11795 | * always be filtered by cgroup2 path as long as perf_event | |
11796 | * controller is not mounted on a legacy hierarchy. | |
11797 | */ | |
11798 | .implicit_on_dfl = true, | |
8cfd8147 | 11799 | .threaded = true, |
e5d1367f SE |
11800 | }; |
11801 | #endif /* CONFIG_CGROUP_PERF */ |