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> | |
0793a61d | 49 | |
76369139 FW |
50 | #include "internal.h" |
51 | ||
4e193bd4 TB |
52 | #include <asm/irq_regs.h> |
53 | ||
272325c4 PZ |
54 | typedef int (*remote_function_f)(void *); |
55 | ||
fe4b04fa | 56 | struct remote_function_call { |
e7e7ee2e | 57 | struct task_struct *p; |
272325c4 | 58 | remote_function_f func; |
e7e7ee2e IM |
59 | void *info; |
60 | int ret; | |
fe4b04fa PZ |
61 | }; |
62 | ||
63 | static void remote_function(void *data) | |
64 | { | |
65 | struct remote_function_call *tfc = data; | |
66 | struct task_struct *p = tfc->p; | |
67 | ||
68 | if (p) { | |
0da4cf3e PZ |
69 | /* -EAGAIN */ |
70 | if (task_cpu(p) != smp_processor_id()) | |
71 | return; | |
72 | ||
73 | /* | |
74 | * Now that we're on right CPU with IRQs disabled, we can test | |
75 | * if we hit the right task without races. | |
76 | */ | |
77 | ||
78 | tfc->ret = -ESRCH; /* No such (running) process */ | |
79 | if (p != current) | |
fe4b04fa PZ |
80 | return; |
81 | } | |
82 | ||
83 | tfc->ret = tfc->func(tfc->info); | |
84 | } | |
85 | ||
86 | /** | |
87 | * task_function_call - call a function on the cpu on which a task runs | |
88 | * @p: the task to evaluate | |
89 | * @func: the function to be called | |
90 | * @info: the function call argument | |
91 | * | |
92 | * Calls the function @func when the task is currently running. This might | |
93 | * be on the current CPU, which just calls the function directly | |
94 | * | |
95 | * returns: @func return value, or | |
96 | * -ESRCH - when the process isn't running | |
97 | * -EAGAIN - when the process moved away | |
98 | */ | |
99 | static int | |
272325c4 | 100 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
101 | { |
102 | struct remote_function_call data = { | |
e7e7ee2e IM |
103 | .p = p, |
104 | .func = func, | |
105 | .info = info, | |
0da4cf3e | 106 | .ret = -EAGAIN, |
fe4b04fa | 107 | }; |
0da4cf3e | 108 | int ret; |
fe4b04fa | 109 | |
0da4cf3e PZ |
110 | do { |
111 | ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
112 | if (!ret) | |
113 | ret = data.ret; | |
114 | } while (ret == -EAGAIN); | |
fe4b04fa | 115 | |
0da4cf3e | 116 | return ret; |
fe4b04fa PZ |
117 | } |
118 | ||
119 | /** | |
120 | * cpu_function_call - call a function on the cpu | |
121 | * @func: the function to be called | |
122 | * @info: the function call argument | |
123 | * | |
124 | * Calls the function @func on the remote cpu. | |
125 | * | |
126 | * returns: @func return value or -ENXIO when the cpu is offline | |
127 | */ | |
272325c4 | 128 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
129 | { |
130 | struct remote_function_call data = { | |
e7e7ee2e IM |
131 | .p = NULL, |
132 | .func = func, | |
133 | .info = info, | |
134 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
135 | }; |
136 | ||
137 | smp_call_function_single(cpu, remote_function, &data, 1); | |
138 | ||
139 | return data.ret; | |
140 | } | |
141 | ||
fae3fde6 PZ |
142 | static inline struct perf_cpu_context * |
143 | __get_cpu_context(struct perf_event_context *ctx) | |
144 | { | |
145 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
146 | } | |
147 | ||
148 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
149 | struct perf_event_context *ctx) | |
0017960f | 150 | { |
fae3fde6 PZ |
151 | raw_spin_lock(&cpuctx->ctx.lock); |
152 | if (ctx) | |
153 | raw_spin_lock(&ctx->lock); | |
154 | } | |
155 | ||
156 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
157 | struct perf_event_context *ctx) | |
158 | { | |
159 | if (ctx) | |
160 | raw_spin_unlock(&ctx->lock); | |
161 | raw_spin_unlock(&cpuctx->ctx.lock); | |
162 | } | |
163 | ||
63b6da39 PZ |
164 | #define TASK_TOMBSTONE ((void *)-1L) |
165 | ||
166 | static bool is_kernel_event(struct perf_event *event) | |
167 | { | |
f47c02c0 | 168 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
169 | } |
170 | ||
39a43640 PZ |
171 | /* |
172 | * On task ctx scheduling... | |
173 | * | |
174 | * When !ctx->nr_events a task context will not be scheduled. This means | |
175 | * we can disable the scheduler hooks (for performance) without leaving | |
176 | * pending task ctx state. | |
177 | * | |
178 | * This however results in two special cases: | |
179 | * | |
180 | * - removing the last event from a task ctx; this is relatively straight | |
181 | * forward and is done in __perf_remove_from_context. | |
182 | * | |
183 | * - adding the first event to a task ctx; this is tricky because we cannot | |
184 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
185 | * See perf_install_in_context(). | |
186 | * | |
39a43640 PZ |
187 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. |
188 | */ | |
189 | ||
fae3fde6 PZ |
190 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
191 | struct perf_event_context *, void *); | |
192 | ||
193 | struct event_function_struct { | |
194 | struct perf_event *event; | |
195 | event_f func; | |
196 | void *data; | |
197 | }; | |
198 | ||
199 | static int event_function(void *info) | |
200 | { | |
201 | struct event_function_struct *efs = info; | |
202 | struct perf_event *event = efs->event; | |
0017960f | 203 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
204 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
205 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 206 | int ret = 0; |
fae3fde6 PZ |
207 | |
208 | WARN_ON_ONCE(!irqs_disabled()); | |
209 | ||
63b6da39 | 210 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
211 | /* |
212 | * Since we do the IPI call without holding ctx->lock things can have | |
213 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
214 | */ |
215 | if (ctx->task) { | |
63b6da39 | 216 | if (ctx->task != current) { |
0da4cf3e | 217 | ret = -ESRCH; |
63b6da39 PZ |
218 | goto unlock; |
219 | } | |
fae3fde6 | 220 | |
fae3fde6 PZ |
221 | /* |
222 | * We only use event_function_call() on established contexts, | |
223 | * and event_function() is only ever called when active (or | |
224 | * rather, we'll have bailed in task_function_call() or the | |
225 | * above ctx->task != current test), therefore we must have | |
226 | * ctx->is_active here. | |
227 | */ | |
228 | WARN_ON_ONCE(!ctx->is_active); | |
229 | /* | |
230 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
231 | * match. | |
232 | */ | |
63b6da39 PZ |
233 | WARN_ON_ONCE(task_ctx != ctx); |
234 | } else { | |
235 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 236 | } |
63b6da39 | 237 | |
fae3fde6 | 238 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 239 | unlock: |
fae3fde6 PZ |
240 | perf_ctx_unlock(cpuctx, task_ctx); |
241 | ||
63b6da39 | 242 | return ret; |
fae3fde6 PZ |
243 | } |
244 | ||
245 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
246 | { | |
247 | struct event_function_struct efs = { | |
248 | .event = event, | |
249 | .func = func, | |
250 | .data = data, | |
251 | }; | |
252 | ||
253 | int ret = event_function(&efs); | |
254 | WARN_ON_ONCE(ret); | |
255 | } | |
256 | ||
257 | static void event_function_call(struct perf_event *event, event_f func, void *data) | |
0017960f PZ |
258 | { |
259 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 260 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
261 | struct event_function_struct efs = { |
262 | .event = event, | |
263 | .func = func, | |
264 | .data = data, | |
265 | }; | |
0017960f | 266 | |
c97f4736 PZ |
267 | if (!event->parent) { |
268 | /* | |
269 | * If this is a !child event, we must hold ctx::mutex to | |
270 | * stabilize the the event->ctx relation. See | |
271 | * perf_event_ctx_lock(). | |
272 | */ | |
273 | lockdep_assert_held(&ctx->mutex); | |
274 | } | |
0017960f PZ |
275 | |
276 | if (!task) { | |
fae3fde6 | 277 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
278 | return; |
279 | } | |
280 | ||
63b6da39 PZ |
281 | if (task == TASK_TOMBSTONE) |
282 | return; | |
283 | ||
a096309b | 284 | again: |
fae3fde6 | 285 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
286 | return; |
287 | ||
288 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
289 | /* |
290 | * Reload the task pointer, it might have been changed by | |
291 | * a concurrent perf_event_context_sched_out(). | |
292 | */ | |
293 | task = ctx->task; | |
a096309b PZ |
294 | if (task == TASK_TOMBSTONE) { |
295 | raw_spin_unlock_irq(&ctx->lock); | |
296 | return; | |
0017960f | 297 | } |
a096309b PZ |
298 | if (ctx->is_active) { |
299 | raw_spin_unlock_irq(&ctx->lock); | |
300 | goto again; | |
301 | } | |
302 | func(event, NULL, ctx, data); | |
0017960f PZ |
303 | raw_spin_unlock_irq(&ctx->lock); |
304 | } | |
305 | ||
e5d1367f SE |
306 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
307 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
308 | PERF_FLAG_PID_CGROUP |\ |
309 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 310 | |
bce38cd5 SE |
311 | /* |
312 | * branch priv levels that need permission checks | |
313 | */ | |
314 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
315 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
316 | PERF_SAMPLE_BRANCH_HV) | |
317 | ||
0b3fcf17 SE |
318 | enum event_type_t { |
319 | EVENT_FLEXIBLE = 0x1, | |
320 | EVENT_PINNED = 0x2, | |
3cbaa590 | 321 | EVENT_TIME = 0x4, |
0b3fcf17 SE |
322 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
323 | }; | |
324 | ||
e5d1367f SE |
325 | /* |
326 | * perf_sched_events : >0 events exist | |
327 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
328 | */ | |
9107c89e PZ |
329 | |
330 | static void perf_sched_delayed(struct work_struct *work); | |
331 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
332 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
333 | static DEFINE_MUTEX(perf_sched_mutex); | |
334 | static atomic_t perf_sched_count; | |
335 | ||
e5d1367f | 336 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 337 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 338 | |
cdd6c482 IM |
339 | static atomic_t nr_mmap_events __read_mostly; |
340 | static atomic_t nr_comm_events __read_mostly; | |
341 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 342 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 343 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 344 | |
108b02cf PZ |
345 | static LIST_HEAD(pmus); |
346 | static DEFINE_MUTEX(pmus_lock); | |
347 | static struct srcu_struct pmus_srcu; | |
348 | ||
0764771d | 349 | /* |
cdd6c482 | 350 | * perf event paranoia level: |
0fbdea19 IM |
351 | * -1 - not paranoid at all |
352 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 353 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 354 | * 2 - disallow kernel profiling for unpriv |
0764771d | 355 | */ |
cdd6c482 | 356 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 357 | |
20443384 FW |
358 | /* Minimum for 512 kiB + 1 user control page */ |
359 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
360 | |
361 | /* | |
cdd6c482 | 362 | * max perf event sample rate |
df58ab24 | 363 | */ |
14c63f17 DH |
364 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
365 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
366 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
367 | ||
368 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
369 | ||
370 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
371 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
372 | ||
d9494cb4 PZ |
373 | static int perf_sample_allowed_ns __read_mostly = |
374 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 375 | |
18ab2cd3 | 376 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
377 | { |
378 | u64 tmp = perf_sample_period_ns; | |
379 | ||
380 | tmp *= sysctl_perf_cpu_time_max_percent; | |
91a612ee PZ |
381 | tmp = div_u64(tmp, 100); |
382 | if (!tmp) | |
383 | tmp = 1; | |
384 | ||
385 | WRITE_ONCE(perf_sample_allowed_ns, tmp); | |
14c63f17 | 386 | } |
163ec435 | 387 | |
9e630205 SE |
388 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
389 | ||
163ec435 PZ |
390 | int perf_proc_update_handler(struct ctl_table *table, int write, |
391 | void __user *buffer, size_t *lenp, | |
392 | loff_t *ppos) | |
393 | { | |
723478c8 | 394 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
395 | |
396 | if (ret || !write) | |
397 | return ret; | |
398 | ||
399 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
400 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
401 | update_perf_cpu_limits(); | |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
406 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
407 | ||
408 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
409 | void __user *buffer, size_t *lenp, | |
410 | loff_t *ppos) | |
411 | { | |
412 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
413 | ||
414 | if (ret || !write) | |
415 | return ret; | |
416 | ||
b303e7c1 PZ |
417 | if (sysctl_perf_cpu_time_max_percent == 100 || |
418 | sysctl_perf_cpu_time_max_percent == 0) { | |
91a612ee PZ |
419 | printk(KERN_WARNING |
420 | "perf: Dynamic interrupt throttling disabled, can hang your system!\n"); | |
421 | WRITE_ONCE(perf_sample_allowed_ns, 0); | |
422 | } else { | |
423 | update_perf_cpu_limits(); | |
424 | } | |
163ec435 PZ |
425 | |
426 | return 0; | |
427 | } | |
1ccd1549 | 428 | |
14c63f17 DH |
429 | /* |
430 | * perf samples are done in some very critical code paths (NMIs). | |
431 | * If they take too much CPU time, the system can lock up and not | |
432 | * get any real work done. This will drop the sample rate when | |
433 | * we detect that events are taking too long. | |
434 | */ | |
435 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 436 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 437 | |
91a612ee PZ |
438 | static u64 __report_avg; |
439 | static u64 __report_allowed; | |
440 | ||
6a02ad66 | 441 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 442 | { |
6a02ad66 | 443 | printk_ratelimited(KERN_WARNING |
91a612ee PZ |
444 | "perf: interrupt took too long (%lld > %lld), lowering " |
445 | "kernel.perf_event_max_sample_rate to %d\n", | |
446 | __report_avg, __report_allowed, | |
447 | sysctl_perf_event_sample_rate); | |
6a02ad66 PZ |
448 | } |
449 | ||
450 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
451 | ||
452 | void perf_sample_event_took(u64 sample_len_ns) | |
453 | { | |
91a612ee PZ |
454 | u64 max_len = READ_ONCE(perf_sample_allowed_ns); |
455 | u64 running_len; | |
456 | u64 avg_len; | |
457 | u32 max; | |
14c63f17 | 458 | |
91a612ee | 459 | if (max_len == 0) |
14c63f17 DH |
460 | return; |
461 | ||
91a612ee PZ |
462 | /* Decay the counter by 1 average sample. */ |
463 | running_len = __this_cpu_read(running_sample_length); | |
464 | running_len -= running_len/NR_ACCUMULATED_SAMPLES; | |
465 | running_len += sample_len_ns; | |
466 | __this_cpu_write(running_sample_length, running_len); | |
14c63f17 DH |
467 | |
468 | /* | |
91a612ee PZ |
469 | * Note: this will be biased artifically low until we have |
470 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
14c63f17 DH |
471 | * from having to maintain a count. |
472 | */ | |
91a612ee PZ |
473 | avg_len = running_len/NR_ACCUMULATED_SAMPLES; |
474 | if (avg_len <= max_len) | |
14c63f17 DH |
475 | return; |
476 | ||
91a612ee PZ |
477 | __report_avg = avg_len; |
478 | __report_allowed = max_len; | |
14c63f17 | 479 | |
91a612ee PZ |
480 | /* |
481 | * Compute a throttle threshold 25% below the current duration. | |
482 | */ | |
483 | avg_len += avg_len / 4; | |
484 | max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent; | |
485 | if (avg_len < max) | |
486 | max /= (u32)avg_len; | |
487 | else | |
488 | max = 1; | |
14c63f17 | 489 | |
91a612ee PZ |
490 | WRITE_ONCE(perf_sample_allowed_ns, avg_len); |
491 | WRITE_ONCE(max_samples_per_tick, max); | |
492 | ||
493 | sysctl_perf_event_sample_rate = max * HZ; | |
494 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
6a02ad66 | 495 | |
cd578abb | 496 | if (!irq_work_queue(&perf_duration_work)) { |
91a612ee | 497 | early_printk("perf: interrupt took too long (%lld > %lld), lowering " |
cd578abb | 498 | "kernel.perf_event_max_sample_rate to %d\n", |
91a612ee | 499 | __report_avg, __report_allowed, |
cd578abb PZ |
500 | sysctl_perf_event_sample_rate); |
501 | } | |
14c63f17 DH |
502 | } |
503 | ||
cdd6c482 | 504 | static atomic64_t perf_event_id; |
a96bbc16 | 505 | |
0b3fcf17 SE |
506 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
507 | enum event_type_t event_type); | |
508 | ||
509 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
510 | enum event_type_t event_type, |
511 | struct task_struct *task); | |
512 | ||
513 | static void update_context_time(struct perf_event_context *ctx); | |
514 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 515 | |
cdd6c482 | 516 | void __weak perf_event_print_debug(void) { } |
0793a61d | 517 | |
84c79910 | 518 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 519 | { |
84c79910 | 520 | return "pmu"; |
0793a61d TG |
521 | } |
522 | ||
0b3fcf17 SE |
523 | static inline u64 perf_clock(void) |
524 | { | |
525 | return local_clock(); | |
526 | } | |
527 | ||
34f43927 PZ |
528 | static inline u64 perf_event_clock(struct perf_event *event) |
529 | { | |
530 | return event->clock(); | |
531 | } | |
532 | ||
e5d1367f SE |
533 | #ifdef CONFIG_CGROUP_PERF |
534 | ||
e5d1367f SE |
535 | static inline bool |
536 | perf_cgroup_match(struct perf_event *event) | |
537 | { | |
538 | struct perf_event_context *ctx = event->ctx; | |
539 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
540 | ||
ef824fa1 TH |
541 | /* @event doesn't care about cgroup */ |
542 | if (!event->cgrp) | |
543 | return true; | |
544 | ||
545 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
546 | if (!cpuctx->cgrp) | |
547 | return false; | |
548 | ||
549 | /* | |
550 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
551 | * also enabled for all its descendant cgroups. If @cpuctx's | |
552 | * cgroup is a descendant of @event's (the test covers identity | |
553 | * case), it's a match. | |
554 | */ | |
555 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
556 | event->cgrp->css.cgroup); | |
e5d1367f SE |
557 | } |
558 | ||
e5d1367f SE |
559 | static inline void perf_detach_cgroup(struct perf_event *event) |
560 | { | |
4e2ba650 | 561 | css_put(&event->cgrp->css); |
e5d1367f SE |
562 | event->cgrp = NULL; |
563 | } | |
564 | ||
565 | static inline int is_cgroup_event(struct perf_event *event) | |
566 | { | |
567 | return event->cgrp != NULL; | |
568 | } | |
569 | ||
570 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
571 | { | |
572 | struct perf_cgroup_info *t; | |
573 | ||
574 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
575 | return t->time; | |
576 | } | |
577 | ||
578 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
579 | { | |
580 | struct perf_cgroup_info *info; | |
581 | u64 now; | |
582 | ||
583 | now = perf_clock(); | |
584 | ||
585 | info = this_cpu_ptr(cgrp->info); | |
586 | ||
587 | info->time += now - info->timestamp; | |
588 | info->timestamp = now; | |
589 | } | |
590 | ||
591 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
592 | { | |
593 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
594 | if (cgrp_out) | |
595 | __update_cgrp_time(cgrp_out); | |
596 | } | |
597 | ||
598 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
599 | { | |
3f7cce3c SE |
600 | struct perf_cgroup *cgrp; |
601 | ||
e5d1367f | 602 | /* |
3f7cce3c SE |
603 | * ensure we access cgroup data only when needed and |
604 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 605 | */ |
3f7cce3c | 606 | if (!is_cgroup_event(event)) |
e5d1367f SE |
607 | return; |
608 | ||
614e4c4e | 609 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
610 | /* |
611 | * Do not update time when cgroup is not active | |
612 | */ | |
613 | if (cgrp == event->cgrp) | |
614 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
615 | } |
616 | ||
617 | static inline void | |
3f7cce3c SE |
618 | perf_cgroup_set_timestamp(struct task_struct *task, |
619 | struct perf_event_context *ctx) | |
e5d1367f SE |
620 | { |
621 | struct perf_cgroup *cgrp; | |
622 | struct perf_cgroup_info *info; | |
623 | ||
3f7cce3c SE |
624 | /* |
625 | * ctx->lock held by caller | |
626 | * ensure we do not access cgroup data | |
627 | * unless we have the cgroup pinned (css_get) | |
628 | */ | |
629 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
630 | return; |
631 | ||
614e4c4e | 632 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 633 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 634 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
635 | } |
636 | ||
637 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
638 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
639 | ||
640 | /* | |
641 | * reschedule events based on the cgroup constraint of task. | |
642 | * | |
643 | * mode SWOUT : schedule out everything | |
644 | * mode SWIN : schedule in based on cgroup for next | |
645 | */ | |
18ab2cd3 | 646 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
647 | { |
648 | struct perf_cpu_context *cpuctx; | |
649 | struct pmu *pmu; | |
650 | unsigned long flags; | |
651 | ||
652 | /* | |
653 | * disable interrupts to avoid geting nr_cgroup | |
654 | * changes via __perf_event_disable(). Also | |
655 | * avoids preemption. | |
656 | */ | |
657 | local_irq_save(flags); | |
658 | ||
659 | /* | |
660 | * we reschedule only in the presence of cgroup | |
661 | * constrained events. | |
662 | */ | |
e5d1367f SE |
663 | |
664 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 665 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
666 | if (cpuctx->unique_pmu != pmu) |
667 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 668 | |
e5d1367f SE |
669 | /* |
670 | * perf_cgroup_events says at least one | |
671 | * context on this CPU has cgroup events. | |
672 | * | |
673 | * ctx->nr_cgroups reports the number of cgroup | |
674 | * events for a context. | |
675 | */ | |
676 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
677 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
678 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
679 | |
680 | if (mode & PERF_CGROUP_SWOUT) { | |
681 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
682 | /* | |
683 | * must not be done before ctxswout due | |
684 | * to event_filter_match() in event_sched_out() | |
685 | */ | |
686 | cpuctx->cgrp = NULL; | |
687 | } | |
688 | ||
689 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 690 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
691 | /* |
692 | * set cgrp before ctxsw in to allow | |
693 | * event_filter_match() to not have to pass | |
694 | * task around | |
614e4c4e SE |
695 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
696 | * because cgorup events are only per-cpu | |
e5d1367f | 697 | */ |
614e4c4e | 698 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
699 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
700 | } | |
facc4307 PZ |
701 | perf_pmu_enable(cpuctx->ctx.pmu); |
702 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 703 | } |
e5d1367f SE |
704 | } |
705 | ||
e5d1367f SE |
706 | local_irq_restore(flags); |
707 | } | |
708 | ||
a8d757ef SE |
709 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
710 | struct task_struct *next) | |
e5d1367f | 711 | { |
a8d757ef SE |
712 | struct perf_cgroup *cgrp1; |
713 | struct perf_cgroup *cgrp2 = NULL; | |
714 | ||
ddaaf4e2 | 715 | rcu_read_lock(); |
a8d757ef SE |
716 | /* |
717 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
718 | * we do not need to pass the ctx here because we know |
719 | * we are holding the rcu lock | |
a8d757ef | 720 | */ |
614e4c4e | 721 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 722 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
723 | |
724 | /* | |
725 | * only schedule out current cgroup events if we know | |
726 | * that we are switching to a different cgroup. Otherwise, | |
727 | * do no touch the cgroup events. | |
728 | */ | |
729 | if (cgrp1 != cgrp2) | |
730 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
731 | |
732 | rcu_read_unlock(); | |
e5d1367f SE |
733 | } |
734 | ||
a8d757ef SE |
735 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
736 | struct task_struct *task) | |
e5d1367f | 737 | { |
a8d757ef SE |
738 | struct perf_cgroup *cgrp1; |
739 | struct perf_cgroup *cgrp2 = NULL; | |
740 | ||
ddaaf4e2 | 741 | rcu_read_lock(); |
a8d757ef SE |
742 | /* |
743 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
744 | * we do not need to pass the ctx here because we know |
745 | * we are holding the rcu lock | |
a8d757ef | 746 | */ |
614e4c4e | 747 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 748 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
749 | |
750 | /* | |
751 | * only need to schedule in cgroup events if we are changing | |
752 | * cgroup during ctxsw. Cgroup events were not scheduled | |
753 | * out of ctxsw out if that was not the case. | |
754 | */ | |
755 | if (cgrp1 != cgrp2) | |
756 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
757 | |
758 | rcu_read_unlock(); | |
e5d1367f SE |
759 | } |
760 | ||
761 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
762 | struct perf_event_attr *attr, | |
763 | struct perf_event *group_leader) | |
764 | { | |
765 | struct perf_cgroup *cgrp; | |
766 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
767 | struct fd f = fdget(fd); |
768 | int ret = 0; | |
e5d1367f | 769 | |
2903ff01 | 770 | if (!f.file) |
e5d1367f SE |
771 | return -EBADF; |
772 | ||
b583043e | 773 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 774 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
775 | if (IS_ERR(css)) { |
776 | ret = PTR_ERR(css); | |
777 | goto out; | |
778 | } | |
e5d1367f SE |
779 | |
780 | cgrp = container_of(css, struct perf_cgroup, css); | |
781 | event->cgrp = cgrp; | |
782 | ||
783 | /* | |
784 | * all events in a group must monitor | |
785 | * the same cgroup because a task belongs | |
786 | * to only one perf cgroup at a time | |
787 | */ | |
788 | if (group_leader && group_leader->cgrp != cgrp) { | |
789 | perf_detach_cgroup(event); | |
790 | ret = -EINVAL; | |
e5d1367f | 791 | } |
3db272c0 | 792 | out: |
2903ff01 | 793 | fdput(f); |
e5d1367f SE |
794 | return ret; |
795 | } | |
796 | ||
797 | static inline void | |
798 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
799 | { | |
800 | struct perf_cgroup_info *t; | |
801 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
802 | event->shadow_ctx_time = now - t->timestamp; | |
803 | } | |
804 | ||
805 | static inline void | |
806 | perf_cgroup_defer_enabled(struct perf_event *event) | |
807 | { | |
808 | /* | |
809 | * when the current task's perf cgroup does not match | |
810 | * the event's, we need to remember to call the | |
811 | * perf_mark_enable() function the first time a task with | |
812 | * a matching perf cgroup is scheduled in. | |
813 | */ | |
814 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
815 | event->cgrp_defer_enabled = 1; | |
816 | } | |
817 | ||
818 | static inline void | |
819 | perf_cgroup_mark_enabled(struct perf_event *event, | |
820 | struct perf_event_context *ctx) | |
821 | { | |
822 | struct perf_event *sub; | |
823 | u64 tstamp = perf_event_time(event); | |
824 | ||
825 | if (!event->cgrp_defer_enabled) | |
826 | return; | |
827 | ||
828 | event->cgrp_defer_enabled = 0; | |
829 | ||
830 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
831 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
832 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
833 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
834 | sub->cgrp_defer_enabled = 0; | |
835 | } | |
836 | } | |
837 | } | |
838 | #else /* !CONFIG_CGROUP_PERF */ | |
839 | ||
840 | static inline bool | |
841 | perf_cgroup_match(struct perf_event *event) | |
842 | { | |
843 | return true; | |
844 | } | |
845 | ||
846 | static inline void perf_detach_cgroup(struct perf_event *event) | |
847 | {} | |
848 | ||
849 | static inline int is_cgroup_event(struct perf_event *event) | |
850 | { | |
851 | return 0; | |
852 | } | |
853 | ||
854 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
855 | { | |
856 | return 0; | |
857 | } | |
858 | ||
859 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
860 | { | |
861 | } | |
862 | ||
863 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
864 | { | |
865 | } | |
866 | ||
a8d757ef SE |
867 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
868 | struct task_struct *next) | |
e5d1367f SE |
869 | { |
870 | } | |
871 | ||
a8d757ef SE |
872 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
873 | struct task_struct *task) | |
e5d1367f SE |
874 | { |
875 | } | |
876 | ||
877 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
878 | struct perf_event_attr *attr, | |
879 | struct perf_event *group_leader) | |
880 | { | |
881 | return -EINVAL; | |
882 | } | |
883 | ||
884 | static inline void | |
3f7cce3c SE |
885 | perf_cgroup_set_timestamp(struct task_struct *task, |
886 | struct perf_event_context *ctx) | |
e5d1367f SE |
887 | { |
888 | } | |
889 | ||
890 | void | |
891 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
892 | { | |
893 | } | |
894 | ||
895 | static inline void | |
896 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
897 | { | |
898 | } | |
899 | ||
900 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
901 | { | |
902 | return 0; | |
903 | } | |
904 | ||
905 | static inline void | |
906 | perf_cgroup_defer_enabled(struct perf_event *event) | |
907 | { | |
908 | } | |
909 | ||
910 | static inline void | |
911 | perf_cgroup_mark_enabled(struct perf_event *event, | |
912 | struct perf_event_context *ctx) | |
913 | { | |
914 | } | |
915 | #endif | |
916 | ||
9e630205 SE |
917 | /* |
918 | * set default to be dependent on timer tick just | |
919 | * like original code | |
920 | */ | |
921 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
922 | /* | |
923 | * function must be called with interrupts disbled | |
924 | */ | |
272325c4 | 925 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
926 | { |
927 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
928 | int rotations = 0; |
929 | ||
930 | WARN_ON(!irqs_disabled()); | |
931 | ||
932 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
933 | rotations = perf_rotate_context(cpuctx); |
934 | ||
4cfafd30 PZ |
935 | raw_spin_lock(&cpuctx->hrtimer_lock); |
936 | if (rotations) | |
9e630205 | 937 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
938 | else |
939 | cpuctx->hrtimer_active = 0; | |
940 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 941 | |
4cfafd30 | 942 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
943 | } |
944 | ||
272325c4 | 945 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 946 | { |
272325c4 | 947 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 948 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 949 | u64 interval; |
9e630205 SE |
950 | |
951 | /* no multiplexing needed for SW PMU */ | |
952 | if (pmu->task_ctx_nr == perf_sw_context) | |
953 | return; | |
954 | ||
62b85639 SE |
955 | /* |
956 | * check default is sane, if not set then force to | |
957 | * default interval (1/tick) | |
958 | */ | |
272325c4 PZ |
959 | interval = pmu->hrtimer_interval_ms; |
960 | if (interval < 1) | |
961 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 962 | |
272325c4 | 963 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 964 | |
4cfafd30 PZ |
965 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
966 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 967 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
968 | } |
969 | ||
272325c4 | 970 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 971 | { |
272325c4 | 972 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 973 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 974 | unsigned long flags; |
9e630205 SE |
975 | |
976 | /* not for SW PMU */ | |
977 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 978 | return 0; |
9e630205 | 979 | |
4cfafd30 PZ |
980 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
981 | if (!cpuctx->hrtimer_active) { | |
982 | cpuctx->hrtimer_active = 1; | |
983 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
984 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
985 | } | |
986 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 987 | |
272325c4 | 988 | return 0; |
9e630205 SE |
989 | } |
990 | ||
33696fc0 | 991 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 992 | { |
33696fc0 PZ |
993 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
994 | if (!(*count)++) | |
995 | pmu->pmu_disable(pmu); | |
9e35ad38 | 996 | } |
9e35ad38 | 997 | |
33696fc0 | 998 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 999 | { |
33696fc0 PZ |
1000 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
1001 | if (!--(*count)) | |
1002 | pmu->pmu_enable(pmu); | |
9e35ad38 | 1003 | } |
9e35ad38 | 1004 | |
2fde4f94 | 1005 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
1006 | |
1007 | /* | |
2fde4f94 MR |
1008 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
1009 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
1010 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
1011 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 1012 | */ |
2fde4f94 | 1013 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 1014 | { |
2fde4f94 | 1015 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 1016 | |
e9d2b064 | 1017 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 1018 | |
2fde4f94 MR |
1019 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1020 | ||
1021 | list_add(&ctx->active_ctx_list, head); | |
1022 | } | |
1023 | ||
1024 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1025 | { | |
1026 | WARN_ON(!irqs_disabled()); | |
1027 | ||
1028 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1029 | ||
1030 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1031 | } |
9e35ad38 | 1032 | |
cdd6c482 | 1033 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1034 | { |
e5289d4a | 1035 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1036 | } |
1037 | ||
4af57ef2 YZ |
1038 | static void free_ctx(struct rcu_head *head) |
1039 | { | |
1040 | struct perf_event_context *ctx; | |
1041 | ||
1042 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1043 | kfree(ctx->task_ctx_data); | |
1044 | kfree(ctx); | |
1045 | } | |
1046 | ||
cdd6c482 | 1047 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1048 | { |
564c2b21 PM |
1049 | if (atomic_dec_and_test(&ctx->refcount)) { |
1050 | if (ctx->parent_ctx) | |
1051 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1052 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1053 | put_task_struct(ctx->task); |
4af57ef2 | 1054 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1055 | } |
a63eaf34 PM |
1056 | } |
1057 | ||
f63a8daa PZ |
1058 | /* |
1059 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1060 | * perf_pmu_migrate_context() we need some magic. | |
1061 | * | |
1062 | * Those places that change perf_event::ctx will hold both | |
1063 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1064 | * | |
8b10c5e2 PZ |
1065 | * Lock ordering is by mutex address. There are two other sites where |
1066 | * perf_event_context::mutex nests and those are: | |
1067 | * | |
1068 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1069 | * perf_event_exit_event() |
1070 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1071 | * |
1072 | * - perf_event_init_context() [ parent, 0 ] | |
1073 | * inherit_task_group() | |
1074 | * inherit_group() | |
1075 | * inherit_event() | |
1076 | * perf_event_alloc() | |
1077 | * perf_init_event() | |
1078 | * perf_try_init_event() [ child , 1 ] | |
1079 | * | |
1080 | * While it appears there is an obvious deadlock here -- the parent and child | |
1081 | * nesting levels are inverted between the two. This is in fact safe because | |
1082 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1083 | * spawning task cannot (yet) exit. | |
1084 | * | |
1085 | * But remember that that these are parent<->child context relations, and | |
1086 | * migration does not affect children, therefore these two orderings should not | |
1087 | * interact. | |
f63a8daa PZ |
1088 | * |
1089 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1090 | * because the sys_perf_event_open() case will install a new event and break | |
1091 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1092 | * concerned with cpuctx and that doesn't have children. | |
1093 | * | |
1094 | * The places that change perf_event::ctx will issue: | |
1095 | * | |
1096 | * perf_remove_from_context(); | |
1097 | * synchronize_rcu(); | |
1098 | * perf_install_in_context(); | |
1099 | * | |
1100 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1101 | * quiesce the event, after which we can install it in the new location. This | |
1102 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1103 | * while in transit. Therefore all such accessors should also acquire | |
1104 | * perf_event_context::mutex to serialize against this. | |
1105 | * | |
1106 | * However; because event->ctx can change while we're waiting to acquire | |
1107 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1108 | * function. | |
1109 | * | |
1110 | * Lock order: | |
79c9ce57 | 1111 | * cred_guard_mutex |
f63a8daa PZ |
1112 | * task_struct::perf_event_mutex |
1113 | * perf_event_context::mutex | |
f63a8daa | 1114 | * perf_event::child_mutex; |
07c4a776 | 1115 | * perf_event_context::lock |
f63a8daa PZ |
1116 | * perf_event::mmap_mutex |
1117 | * mmap_sem | |
1118 | */ | |
a83fe28e PZ |
1119 | static struct perf_event_context * |
1120 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1121 | { |
1122 | struct perf_event_context *ctx; | |
1123 | ||
1124 | again: | |
1125 | rcu_read_lock(); | |
1126 | ctx = ACCESS_ONCE(event->ctx); | |
1127 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1128 | rcu_read_unlock(); | |
1129 | goto again; | |
1130 | } | |
1131 | rcu_read_unlock(); | |
1132 | ||
a83fe28e | 1133 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1134 | if (event->ctx != ctx) { |
1135 | mutex_unlock(&ctx->mutex); | |
1136 | put_ctx(ctx); | |
1137 | goto again; | |
1138 | } | |
1139 | ||
1140 | return ctx; | |
1141 | } | |
1142 | ||
a83fe28e PZ |
1143 | static inline struct perf_event_context * |
1144 | perf_event_ctx_lock(struct perf_event *event) | |
1145 | { | |
1146 | return perf_event_ctx_lock_nested(event, 0); | |
1147 | } | |
1148 | ||
f63a8daa PZ |
1149 | static void perf_event_ctx_unlock(struct perf_event *event, |
1150 | struct perf_event_context *ctx) | |
1151 | { | |
1152 | mutex_unlock(&ctx->mutex); | |
1153 | put_ctx(ctx); | |
1154 | } | |
1155 | ||
211de6eb PZ |
1156 | /* |
1157 | * This must be done under the ctx->lock, such as to serialize against | |
1158 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1159 | * calling scheduler related locks and ctx->lock nests inside those. | |
1160 | */ | |
1161 | static __must_check struct perf_event_context * | |
1162 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1163 | { |
211de6eb PZ |
1164 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1165 | ||
1166 | lockdep_assert_held(&ctx->lock); | |
1167 | ||
1168 | if (parent_ctx) | |
71a851b4 | 1169 | ctx->parent_ctx = NULL; |
5a3126d4 | 1170 | ctx->generation++; |
211de6eb PZ |
1171 | |
1172 | return parent_ctx; | |
71a851b4 PZ |
1173 | } |
1174 | ||
6844c09d ACM |
1175 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1176 | { | |
1177 | /* | |
1178 | * only top level events have the pid namespace they were created in | |
1179 | */ | |
1180 | if (event->parent) | |
1181 | event = event->parent; | |
1182 | ||
1183 | return task_tgid_nr_ns(p, event->ns); | |
1184 | } | |
1185 | ||
1186 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1187 | { | |
1188 | /* | |
1189 | * only top level events have the pid namespace they were created in | |
1190 | */ | |
1191 | if (event->parent) | |
1192 | event = event->parent; | |
1193 | ||
1194 | return task_pid_nr_ns(p, event->ns); | |
1195 | } | |
1196 | ||
7f453c24 | 1197 | /* |
cdd6c482 | 1198 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1199 | * to userspace. |
1200 | */ | |
cdd6c482 | 1201 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1202 | { |
cdd6c482 | 1203 | u64 id = event->id; |
7f453c24 | 1204 | |
cdd6c482 IM |
1205 | if (event->parent) |
1206 | id = event->parent->id; | |
7f453c24 PZ |
1207 | |
1208 | return id; | |
1209 | } | |
1210 | ||
25346b93 | 1211 | /* |
cdd6c482 | 1212 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1213 | * |
25346b93 PM |
1214 | * This has to cope with with the fact that until it is locked, |
1215 | * the context could get moved to another task. | |
1216 | */ | |
cdd6c482 | 1217 | static struct perf_event_context * |
8dc85d54 | 1218 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1219 | { |
cdd6c482 | 1220 | struct perf_event_context *ctx; |
25346b93 | 1221 | |
9ed6060d | 1222 | retry: |
058ebd0e PZ |
1223 | /* |
1224 | * One of the few rules of preemptible RCU is that one cannot do | |
1225 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1226 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1227 | * rcu_read_unlock_special(). |
1228 | * | |
1229 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1230 | * side critical section has interrupts disabled. |
058ebd0e | 1231 | */ |
2fd59077 | 1232 | local_irq_save(*flags); |
058ebd0e | 1233 | rcu_read_lock(); |
8dc85d54 | 1234 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1235 | if (ctx) { |
1236 | /* | |
1237 | * If this context is a clone of another, it might | |
1238 | * get swapped for another underneath us by | |
cdd6c482 | 1239 | * perf_event_task_sched_out, though the |
25346b93 PM |
1240 | * rcu_read_lock() protects us from any context |
1241 | * getting freed. Lock the context and check if it | |
1242 | * got swapped before we could get the lock, and retry | |
1243 | * if so. If we locked the right context, then it | |
1244 | * can't get swapped on us any more. | |
1245 | */ | |
2fd59077 | 1246 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1247 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1248 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1249 | rcu_read_unlock(); |
2fd59077 | 1250 | local_irq_restore(*flags); |
25346b93 PM |
1251 | goto retry; |
1252 | } | |
b49a9e7e | 1253 | |
63b6da39 PZ |
1254 | if (ctx->task == TASK_TOMBSTONE || |
1255 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1256 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1257 | ctx = NULL; |
828b6f0e PZ |
1258 | } else { |
1259 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1260 | } |
25346b93 PM |
1261 | } |
1262 | rcu_read_unlock(); | |
2fd59077 PM |
1263 | if (!ctx) |
1264 | local_irq_restore(*flags); | |
25346b93 PM |
1265 | return ctx; |
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * Get the context for a task and increment its pin_count so it | |
1270 | * can't get swapped to another task. This also increments its | |
1271 | * reference count so that the context can't get freed. | |
1272 | */ | |
8dc85d54 PZ |
1273 | static struct perf_event_context * |
1274 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1275 | { |
cdd6c482 | 1276 | struct perf_event_context *ctx; |
25346b93 PM |
1277 | unsigned long flags; |
1278 | ||
8dc85d54 | 1279 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1280 | if (ctx) { |
1281 | ++ctx->pin_count; | |
e625cce1 | 1282 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1283 | } |
1284 | return ctx; | |
1285 | } | |
1286 | ||
cdd6c482 | 1287 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1288 | { |
1289 | unsigned long flags; | |
1290 | ||
e625cce1 | 1291 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1292 | --ctx->pin_count; |
e625cce1 | 1293 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1294 | } |
1295 | ||
f67218c3 PZ |
1296 | /* |
1297 | * Update the record of the current time in a context. | |
1298 | */ | |
1299 | static void update_context_time(struct perf_event_context *ctx) | |
1300 | { | |
1301 | u64 now = perf_clock(); | |
1302 | ||
1303 | ctx->time += now - ctx->timestamp; | |
1304 | ctx->timestamp = now; | |
1305 | } | |
1306 | ||
4158755d SE |
1307 | static u64 perf_event_time(struct perf_event *event) |
1308 | { | |
1309 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1310 | |
1311 | if (is_cgroup_event(event)) | |
1312 | return perf_cgroup_event_time(event); | |
1313 | ||
4158755d SE |
1314 | return ctx ? ctx->time : 0; |
1315 | } | |
1316 | ||
f67218c3 PZ |
1317 | /* |
1318 | * Update the total_time_enabled and total_time_running fields for a event. | |
1319 | */ | |
1320 | static void update_event_times(struct perf_event *event) | |
1321 | { | |
1322 | struct perf_event_context *ctx = event->ctx; | |
1323 | u64 run_end; | |
1324 | ||
3cbaa590 PZ |
1325 | lockdep_assert_held(&ctx->lock); |
1326 | ||
f67218c3 PZ |
1327 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
1328 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1329 | return; | |
3cbaa590 | 1330 | |
e5d1367f SE |
1331 | /* |
1332 | * in cgroup mode, time_enabled represents | |
1333 | * the time the event was enabled AND active | |
1334 | * tasks were in the monitored cgroup. This is | |
1335 | * independent of the activity of the context as | |
1336 | * there may be a mix of cgroup and non-cgroup events. | |
1337 | * | |
1338 | * That is why we treat cgroup events differently | |
1339 | * here. | |
1340 | */ | |
1341 | if (is_cgroup_event(event)) | |
46cd6a7f | 1342 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1343 | else if (ctx->is_active) |
1344 | run_end = ctx->time; | |
acd1d7c1 PZ |
1345 | else |
1346 | run_end = event->tstamp_stopped; | |
1347 | ||
1348 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1349 | |
1350 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1351 | run_end = event->tstamp_stopped; | |
1352 | else | |
4158755d | 1353 | run_end = perf_event_time(event); |
f67218c3 PZ |
1354 | |
1355 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1356 | |
f67218c3 PZ |
1357 | } |
1358 | ||
96c21a46 PZ |
1359 | /* |
1360 | * Update total_time_enabled and total_time_running for all events in a group. | |
1361 | */ | |
1362 | static void update_group_times(struct perf_event *leader) | |
1363 | { | |
1364 | struct perf_event *event; | |
1365 | ||
1366 | update_event_times(leader); | |
1367 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1368 | update_event_times(event); | |
1369 | } | |
1370 | ||
889ff015 FW |
1371 | static struct list_head * |
1372 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1373 | { | |
1374 | if (event->attr.pinned) | |
1375 | return &ctx->pinned_groups; | |
1376 | else | |
1377 | return &ctx->flexible_groups; | |
1378 | } | |
1379 | ||
fccc714b | 1380 | /* |
cdd6c482 | 1381 | * Add a event from the lists for its context. |
fccc714b PZ |
1382 | * Must be called with ctx->mutex and ctx->lock held. |
1383 | */ | |
04289bb9 | 1384 | static void |
cdd6c482 | 1385 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1386 | { |
c994d613 PZ |
1387 | lockdep_assert_held(&ctx->lock); |
1388 | ||
8a49542c PZ |
1389 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1390 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1391 | |
1392 | /* | |
8a49542c PZ |
1393 | * If we're a stand alone event or group leader, we go to the context |
1394 | * list, group events are kept attached to the group so that | |
1395 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1396 | */ |
8a49542c | 1397 | if (event->group_leader == event) { |
889ff015 FW |
1398 | struct list_head *list; |
1399 | ||
d6f962b5 FW |
1400 | if (is_software_event(event)) |
1401 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1402 | ||
889ff015 FW |
1403 | list = ctx_group_list(event, ctx); |
1404 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1405 | } |
592903cd | 1406 | |
08309379 | 1407 | if (is_cgroup_event(event)) |
e5d1367f | 1408 | ctx->nr_cgroups++; |
e5d1367f | 1409 | |
cdd6c482 IM |
1410 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1411 | ctx->nr_events++; | |
1412 | if (event->attr.inherit_stat) | |
bfbd3381 | 1413 | ctx->nr_stat++; |
5a3126d4 PZ |
1414 | |
1415 | ctx->generation++; | |
04289bb9 IM |
1416 | } |
1417 | ||
0231bb53 JO |
1418 | /* |
1419 | * Initialize event state based on the perf_event_attr::disabled. | |
1420 | */ | |
1421 | static inline void perf_event__state_init(struct perf_event *event) | |
1422 | { | |
1423 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1424 | PERF_EVENT_STATE_INACTIVE; | |
1425 | } | |
1426 | ||
a723968c | 1427 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1428 | { |
1429 | int entry = sizeof(u64); /* value */ | |
1430 | int size = 0; | |
1431 | int nr = 1; | |
1432 | ||
1433 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1434 | size += sizeof(u64); | |
1435 | ||
1436 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1437 | size += sizeof(u64); | |
1438 | ||
1439 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1440 | entry += sizeof(u64); | |
1441 | ||
1442 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1443 | nr += nr_siblings; |
c320c7b7 ACM |
1444 | size += sizeof(u64); |
1445 | } | |
1446 | ||
1447 | size += entry * nr; | |
1448 | event->read_size = size; | |
1449 | } | |
1450 | ||
a723968c | 1451 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1452 | { |
1453 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1454 | u16 size = 0; |
1455 | ||
c320c7b7 ACM |
1456 | if (sample_type & PERF_SAMPLE_IP) |
1457 | size += sizeof(data->ip); | |
1458 | ||
6844c09d ACM |
1459 | if (sample_type & PERF_SAMPLE_ADDR) |
1460 | size += sizeof(data->addr); | |
1461 | ||
1462 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1463 | size += sizeof(data->period); | |
1464 | ||
c3feedf2 AK |
1465 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1466 | size += sizeof(data->weight); | |
1467 | ||
6844c09d ACM |
1468 | if (sample_type & PERF_SAMPLE_READ) |
1469 | size += event->read_size; | |
1470 | ||
d6be9ad6 SE |
1471 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1472 | size += sizeof(data->data_src.val); | |
1473 | ||
fdfbbd07 AK |
1474 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1475 | size += sizeof(data->txn); | |
1476 | ||
6844c09d ACM |
1477 | event->header_size = size; |
1478 | } | |
1479 | ||
a723968c PZ |
1480 | /* |
1481 | * Called at perf_event creation and when events are attached/detached from a | |
1482 | * group. | |
1483 | */ | |
1484 | static void perf_event__header_size(struct perf_event *event) | |
1485 | { | |
1486 | __perf_event_read_size(event, | |
1487 | event->group_leader->nr_siblings); | |
1488 | __perf_event_header_size(event, event->attr.sample_type); | |
1489 | } | |
1490 | ||
6844c09d ACM |
1491 | static void perf_event__id_header_size(struct perf_event *event) |
1492 | { | |
1493 | struct perf_sample_data *data; | |
1494 | u64 sample_type = event->attr.sample_type; | |
1495 | u16 size = 0; | |
1496 | ||
c320c7b7 ACM |
1497 | if (sample_type & PERF_SAMPLE_TID) |
1498 | size += sizeof(data->tid_entry); | |
1499 | ||
1500 | if (sample_type & PERF_SAMPLE_TIME) | |
1501 | size += sizeof(data->time); | |
1502 | ||
ff3d527c AH |
1503 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1504 | size += sizeof(data->id); | |
1505 | ||
c320c7b7 ACM |
1506 | if (sample_type & PERF_SAMPLE_ID) |
1507 | size += sizeof(data->id); | |
1508 | ||
1509 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1510 | size += sizeof(data->stream_id); | |
1511 | ||
1512 | if (sample_type & PERF_SAMPLE_CPU) | |
1513 | size += sizeof(data->cpu_entry); | |
1514 | ||
6844c09d | 1515 | event->id_header_size = size; |
c320c7b7 ACM |
1516 | } |
1517 | ||
a723968c PZ |
1518 | static bool perf_event_validate_size(struct perf_event *event) |
1519 | { | |
1520 | /* | |
1521 | * The values computed here will be over-written when we actually | |
1522 | * attach the event. | |
1523 | */ | |
1524 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1525 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1526 | perf_event__id_header_size(event); | |
1527 | ||
1528 | /* | |
1529 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1530 | * Conservative limit to allow for callchains and other variable fields. | |
1531 | */ | |
1532 | if (event->read_size + event->header_size + | |
1533 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1534 | return false; | |
1535 | ||
1536 | return true; | |
1537 | } | |
1538 | ||
8a49542c PZ |
1539 | static void perf_group_attach(struct perf_event *event) |
1540 | { | |
c320c7b7 | 1541 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1542 | |
74c3337c PZ |
1543 | /* |
1544 | * We can have double attach due to group movement in perf_event_open. | |
1545 | */ | |
1546 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1547 | return; | |
1548 | ||
8a49542c PZ |
1549 | event->attach_state |= PERF_ATTACH_GROUP; |
1550 | ||
1551 | if (group_leader == event) | |
1552 | return; | |
1553 | ||
652884fe PZ |
1554 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1555 | ||
8a49542c PZ |
1556 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1557 | !is_software_event(event)) | |
1558 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1559 | ||
1560 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1561 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1562 | |
1563 | perf_event__header_size(group_leader); | |
1564 | ||
1565 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1566 | perf_event__header_size(pos); | |
8a49542c PZ |
1567 | } |
1568 | ||
a63eaf34 | 1569 | /* |
cdd6c482 | 1570 | * Remove a event from the lists for its context. |
fccc714b | 1571 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1572 | */ |
04289bb9 | 1573 | static void |
cdd6c482 | 1574 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1575 | { |
68cacd29 | 1576 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1577 | |
1578 | WARN_ON_ONCE(event->ctx != ctx); | |
1579 | lockdep_assert_held(&ctx->lock); | |
1580 | ||
8a49542c PZ |
1581 | /* |
1582 | * We can have double detach due to exit/hot-unplug + close. | |
1583 | */ | |
1584 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1585 | return; |
8a49542c PZ |
1586 | |
1587 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1588 | ||
68cacd29 | 1589 | if (is_cgroup_event(event)) { |
e5d1367f | 1590 | ctx->nr_cgroups--; |
70a01657 PZ |
1591 | /* |
1592 | * Because cgroup events are always per-cpu events, this will | |
1593 | * always be called from the right CPU. | |
1594 | */ | |
68cacd29 SE |
1595 | cpuctx = __get_cpu_context(ctx); |
1596 | /* | |
70a01657 PZ |
1597 | * If there are no more cgroup events then clear cgrp to avoid |
1598 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1599 | */ |
1600 | if (!ctx->nr_cgroups) | |
1601 | cpuctx->cgrp = NULL; | |
1602 | } | |
e5d1367f | 1603 | |
cdd6c482 IM |
1604 | ctx->nr_events--; |
1605 | if (event->attr.inherit_stat) | |
bfbd3381 | 1606 | ctx->nr_stat--; |
8bc20959 | 1607 | |
cdd6c482 | 1608 | list_del_rcu(&event->event_entry); |
04289bb9 | 1609 | |
8a49542c PZ |
1610 | if (event->group_leader == event) |
1611 | list_del_init(&event->group_entry); | |
5c148194 | 1612 | |
96c21a46 | 1613 | update_group_times(event); |
b2e74a26 SE |
1614 | |
1615 | /* | |
1616 | * If event was in error state, then keep it | |
1617 | * that way, otherwise bogus counts will be | |
1618 | * returned on read(). The only way to get out | |
1619 | * of error state is by explicit re-enabling | |
1620 | * of the event | |
1621 | */ | |
1622 | if (event->state > PERF_EVENT_STATE_OFF) | |
1623 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1624 | |
1625 | ctx->generation++; | |
050735b0 PZ |
1626 | } |
1627 | ||
8a49542c | 1628 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1629 | { |
1630 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1631 | struct list_head *list = NULL; |
1632 | ||
1633 | /* | |
1634 | * We can have double detach due to exit/hot-unplug + close. | |
1635 | */ | |
1636 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1637 | return; | |
1638 | ||
1639 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1640 | ||
1641 | /* | |
1642 | * If this is a sibling, remove it from its group. | |
1643 | */ | |
1644 | if (event->group_leader != event) { | |
1645 | list_del_init(&event->group_entry); | |
1646 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1647 | goto out; |
8a49542c PZ |
1648 | } |
1649 | ||
1650 | if (!list_empty(&event->group_entry)) | |
1651 | list = &event->group_entry; | |
2e2af50b | 1652 | |
04289bb9 | 1653 | /* |
cdd6c482 IM |
1654 | * If this was a group event with sibling events then |
1655 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1656 | * to whatever list we are on. |
04289bb9 | 1657 | */ |
cdd6c482 | 1658 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1659 | if (list) |
1660 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1661 | sibling->group_leader = sibling; |
d6f962b5 FW |
1662 | |
1663 | /* Inherit group flags from the previous leader */ | |
1664 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1665 | |
1666 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1667 | } |
c320c7b7 ACM |
1668 | |
1669 | out: | |
1670 | perf_event__header_size(event->group_leader); | |
1671 | ||
1672 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1673 | perf_event__header_size(tmp); | |
04289bb9 IM |
1674 | } |
1675 | ||
fadfe7be JO |
1676 | static bool is_orphaned_event(struct perf_event *event) |
1677 | { | |
a69b0ca4 | 1678 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1679 | } |
1680 | ||
66eb579e MR |
1681 | static inline int pmu_filter_match(struct perf_event *event) |
1682 | { | |
1683 | struct pmu *pmu = event->pmu; | |
1684 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1685 | } | |
1686 | ||
fa66f07a SE |
1687 | static inline int |
1688 | event_filter_match(struct perf_event *event) | |
1689 | { | |
e5d1367f | 1690 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1691 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1692 | } |
1693 | ||
9ffcfa6f SE |
1694 | static void |
1695 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1696 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1697 | struct perf_event_context *ctx) |
3b6f9e5c | 1698 | { |
4158755d | 1699 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1700 | u64 delta; |
652884fe PZ |
1701 | |
1702 | WARN_ON_ONCE(event->ctx != ctx); | |
1703 | lockdep_assert_held(&ctx->lock); | |
1704 | ||
fa66f07a SE |
1705 | /* |
1706 | * An event which could not be activated because of | |
1707 | * filter mismatch still needs to have its timings | |
1708 | * maintained, otherwise bogus information is return | |
1709 | * via read() for time_enabled, time_running: | |
1710 | */ | |
1711 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1712 | && !event_filter_match(event)) { | |
e5d1367f | 1713 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1714 | event->tstamp_running += delta; |
4158755d | 1715 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1716 | } |
1717 | ||
cdd6c482 | 1718 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1719 | return; |
3b6f9e5c | 1720 | |
44377277 AS |
1721 | perf_pmu_disable(event->pmu); |
1722 | ||
28a967c3 PZ |
1723 | event->tstamp_stopped = tstamp; |
1724 | event->pmu->del(event, 0); | |
1725 | event->oncpu = -1; | |
cdd6c482 IM |
1726 | event->state = PERF_EVENT_STATE_INACTIVE; |
1727 | if (event->pending_disable) { | |
1728 | event->pending_disable = 0; | |
1729 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1730 | } |
3b6f9e5c | 1731 | |
cdd6c482 | 1732 | if (!is_software_event(event)) |
3b6f9e5c | 1733 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1734 | if (!--ctx->nr_active) |
1735 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1736 | if (event->attr.freq && event->attr.sample_freq) |
1737 | ctx->nr_freq--; | |
cdd6c482 | 1738 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1739 | cpuctx->exclusive = 0; |
44377277 AS |
1740 | |
1741 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1742 | } |
1743 | ||
d859e29f | 1744 | static void |
cdd6c482 | 1745 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1746 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1747 | struct perf_event_context *ctx) |
d859e29f | 1748 | { |
cdd6c482 | 1749 | struct perf_event *event; |
fa66f07a | 1750 | int state = group_event->state; |
d859e29f | 1751 | |
cdd6c482 | 1752 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1753 | |
1754 | /* | |
1755 | * Schedule out siblings (if any): | |
1756 | */ | |
cdd6c482 IM |
1757 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1758 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1759 | |
fa66f07a | 1760 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1761 | cpuctx->exclusive = 0; |
1762 | } | |
1763 | ||
45a0e07a | 1764 | #define DETACH_GROUP 0x01UL |
0017960f | 1765 | |
0793a61d | 1766 | /* |
cdd6c482 | 1767 | * Cross CPU call to remove a performance event |
0793a61d | 1768 | * |
cdd6c482 | 1769 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1770 | * remove it from the context list. |
1771 | */ | |
fae3fde6 PZ |
1772 | static void |
1773 | __perf_remove_from_context(struct perf_event *event, | |
1774 | struct perf_cpu_context *cpuctx, | |
1775 | struct perf_event_context *ctx, | |
1776 | void *info) | |
0793a61d | 1777 | { |
45a0e07a | 1778 | unsigned long flags = (unsigned long)info; |
0793a61d | 1779 | |
cdd6c482 | 1780 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1781 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1782 | perf_group_detach(event); |
cdd6c482 | 1783 | list_del_event(event, ctx); |
39a43640 PZ |
1784 | |
1785 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1786 | ctx->is_active = 0; |
39a43640 PZ |
1787 | if (ctx->task) { |
1788 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1789 | cpuctx->task_ctx = NULL; | |
1790 | } | |
64ce3126 | 1791 | } |
0793a61d TG |
1792 | } |
1793 | ||
0793a61d | 1794 | /* |
cdd6c482 | 1795 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1796 | * |
cdd6c482 IM |
1797 | * If event->ctx is a cloned context, callers must make sure that |
1798 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1799 | * remains valid. This is OK when called from perf_release since |
1800 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1801 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1802 | * context has been detached from its task. |
0793a61d | 1803 | */ |
45a0e07a | 1804 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1805 | { |
fae3fde6 | 1806 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1807 | |
45a0e07a | 1808 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1809 | } |
1810 | ||
d859e29f | 1811 | /* |
cdd6c482 | 1812 | * Cross CPU call to disable a performance event |
d859e29f | 1813 | */ |
fae3fde6 PZ |
1814 | static void __perf_event_disable(struct perf_event *event, |
1815 | struct perf_cpu_context *cpuctx, | |
1816 | struct perf_event_context *ctx, | |
1817 | void *info) | |
7b648018 | 1818 | { |
fae3fde6 PZ |
1819 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1820 | return; | |
7b648018 | 1821 | |
fae3fde6 PZ |
1822 | update_context_time(ctx); |
1823 | update_cgrp_time_from_event(event); | |
1824 | update_group_times(event); | |
1825 | if (event == event->group_leader) | |
1826 | group_sched_out(event, cpuctx, ctx); | |
1827 | else | |
1828 | event_sched_out(event, cpuctx, ctx); | |
1829 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1830 | } |
1831 | ||
d859e29f | 1832 | /* |
cdd6c482 | 1833 | * Disable a event. |
c93f7669 | 1834 | * |
cdd6c482 IM |
1835 | * If event->ctx is a cloned context, callers must make sure that |
1836 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1837 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1838 | * perf_event_for_each_child or perf_event_for_each because they |
1839 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1840 | * goes to exit will block in perf_event_exit_event(). |
1841 | * | |
cdd6c482 | 1842 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1843 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1844 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1845 | */ |
f63a8daa | 1846 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1847 | { |
cdd6c482 | 1848 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1849 | |
e625cce1 | 1850 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1851 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1852 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1853 | return; |
53cfbf59 | 1854 | } |
e625cce1 | 1855 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1856 | |
fae3fde6 PZ |
1857 | event_function_call(event, __perf_event_disable, NULL); |
1858 | } | |
1859 | ||
1860 | void perf_event_disable_local(struct perf_event *event) | |
1861 | { | |
1862 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1863 | } |
f63a8daa PZ |
1864 | |
1865 | /* | |
1866 | * Strictly speaking kernel users cannot create groups and therefore this | |
1867 | * interface does not need the perf_event_ctx_lock() magic. | |
1868 | */ | |
1869 | void perf_event_disable(struct perf_event *event) | |
1870 | { | |
1871 | struct perf_event_context *ctx; | |
1872 | ||
1873 | ctx = perf_event_ctx_lock(event); | |
1874 | _perf_event_disable(event); | |
1875 | perf_event_ctx_unlock(event, ctx); | |
1876 | } | |
dcfce4a0 | 1877 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1878 | |
e5d1367f SE |
1879 | static void perf_set_shadow_time(struct perf_event *event, |
1880 | struct perf_event_context *ctx, | |
1881 | u64 tstamp) | |
1882 | { | |
1883 | /* | |
1884 | * use the correct time source for the time snapshot | |
1885 | * | |
1886 | * We could get by without this by leveraging the | |
1887 | * fact that to get to this function, the caller | |
1888 | * has most likely already called update_context_time() | |
1889 | * and update_cgrp_time_xx() and thus both timestamp | |
1890 | * are identical (or very close). Given that tstamp is, | |
1891 | * already adjusted for cgroup, we could say that: | |
1892 | * tstamp - ctx->timestamp | |
1893 | * is equivalent to | |
1894 | * tstamp - cgrp->timestamp. | |
1895 | * | |
1896 | * Then, in perf_output_read(), the calculation would | |
1897 | * work with no changes because: | |
1898 | * - event is guaranteed scheduled in | |
1899 | * - no scheduled out in between | |
1900 | * - thus the timestamp would be the same | |
1901 | * | |
1902 | * But this is a bit hairy. | |
1903 | * | |
1904 | * So instead, we have an explicit cgroup call to remain | |
1905 | * within the time time source all along. We believe it | |
1906 | * is cleaner and simpler to understand. | |
1907 | */ | |
1908 | if (is_cgroup_event(event)) | |
1909 | perf_cgroup_set_shadow_time(event, tstamp); | |
1910 | else | |
1911 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1912 | } | |
1913 | ||
4fe757dd PZ |
1914 | #define MAX_INTERRUPTS (~0ULL) |
1915 | ||
1916 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1917 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1918 | |
235c7fc7 | 1919 | static int |
9ffcfa6f | 1920 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1921 | struct perf_cpu_context *cpuctx, |
6e37738a | 1922 | struct perf_event_context *ctx) |
235c7fc7 | 1923 | { |
4158755d | 1924 | u64 tstamp = perf_event_time(event); |
44377277 | 1925 | int ret = 0; |
4158755d | 1926 | |
63342411 PZ |
1927 | lockdep_assert_held(&ctx->lock); |
1928 | ||
cdd6c482 | 1929 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1930 | return 0; |
1931 | ||
95ff4ca2 AS |
1932 | WRITE_ONCE(event->oncpu, smp_processor_id()); |
1933 | /* | |
1934 | * Order event::oncpu write to happen before the ACTIVE state | |
1935 | * is visible. | |
1936 | */ | |
1937 | smp_wmb(); | |
1938 | WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE); | |
4fe757dd PZ |
1939 | |
1940 | /* | |
1941 | * Unthrottle events, since we scheduled we might have missed several | |
1942 | * ticks already, also for a heavily scheduling task there is little | |
1943 | * guarantee it'll get a tick in a timely manner. | |
1944 | */ | |
1945 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1946 | perf_log_throttle(event, 1); | |
1947 | event->hw.interrupts = 0; | |
1948 | } | |
1949 | ||
235c7fc7 IM |
1950 | /* |
1951 | * The new state must be visible before we turn it on in the hardware: | |
1952 | */ | |
1953 | smp_wmb(); | |
1954 | ||
44377277 AS |
1955 | perf_pmu_disable(event->pmu); |
1956 | ||
72f669c0 SL |
1957 | perf_set_shadow_time(event, ctx, tstamp); |
1958 | ||
ec0d7729 AS |
1959 | perf_log_itrace_start(event); |
1960 | ||
a4eaf7f1 | 1961 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1962 | event->state = PERF_EVENT_STATE_INACTIVE; |
1963 | event->oncpu = -1; | |
44377277 AS |
1964 | ret = -EAGAIN; |
1965 | goto out; | |
235c7fc7 IM |
1966 | } |
1967 | ||
00a2916f PZ |
1968 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1969 | ||
cdd6c482 | 1970 | if (!is_software_event(event)) |
3b6f9e5c | 1971 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1972 | if (!ctx->nr_active++) |
1973 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1974 | if (event->attr.freq && event->attr.sample_freq) |
1975 | ctx->nr_freq++; | |
235c7fc7 | 1976 | |
cdd6c482 | 1977 | if (event->attr.exclusive) |
3b6f9e5c PM |
1978 | cpuctx->exclusive = 1; |
1979 | ||
44377277 AS |
1980 | out: |
1981 | perf_pmu_enable(event->pmu); | |
1982 | ||
1983 | return ret; | |
235c7fc7 IM |
1984 | } |
1985 | ||
6751b71e | 1986 | static int |
cdd6c482 | 1987 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1988 | struct perf_cpu_context *cpuctx, |
6e37738a | 1989 | struct perf_event_context *ctx) |
6751b71e | 1990 | { |
6bde9b6c | 1991 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1992 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1993 | u64 now = ctx->time; |
1994 | bool simulate = false; | |
6751b71e | 1995 | |
cdd6c482 | 1996 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1997 | return 0; |
1998 | ||
fbbe0701 | 1999 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 2000 | |
9ffcfa6f | 2001 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 2002 | pmu->cancel_txn(pmu); |
272325c4 | 2003 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 2004 | return -EAGAIN; |
90151c35 | 2005 | } |
6751b71e PM |
2006 | |
2007 | /* | |
2008 | * Schedule in siblings as one group (if any): | |
2009 | */ | |
cdd6c482 | 2010 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 2011 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 2012 | partial_group = event; |
6751b71e PM |
2013 | goto group_error; |
2014 | } | |
2015 | } | |
2016 | ||
9ffcfa6f | 2017 | if (!pmu->commit_txn(pmu)) |
6e85158c | 2018 | return 0; |
9ffcfa6f | 2019 | |
6751b71e PM |
2020 | group_error: |
2021 | /* | |
2022 | * Groups can be scheduled in as one unit only, so undo any | |
2023 | * partial group before returning: | |
d7842da4 SE |
2024 | * The events up to the failed event are scheduled out normally, |
2025 | * tstamp_stopped will be updated. | |
2026 | * | |
2027 | * The failed events and the remaining siblings need to have | |
2028 | * their timings updated as if they had gone thru event_sched_in() | |
2029 | * and event_sched_out(). This is required to get consistent timings | |
2030 | * across the group. This also takes care of the case where the group | |
2031 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2032 | * the time the event was actually stopped, such that time delta | |
2033 | * calculation in update_event_times() is correct. | |
6751b71e | 2034 | */ |
cdd6c482 IM |
2035 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2036 | if (event == partial_group) | |
d7842da4 SE |
2037 | simulate = true; |
2038 | ||
2039 | if (simulate) { | |
2040 | event->tstamp_running += now - event->tstamp_stopped; | |
2041 | event->tstamp_stopped = now; | |
2042 | } else { | |
2043 | event_sched_out(event, cpuctx, ctx); | |
2044 | } | |
6751b71e | 2045 | } |
9ffcfa6f | 2046 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2047 | |
ad5133b7 | 2048 | pmu->cancel_txn(pmu); |
90151c35 | 2049 | |
272325c4 | 2050 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2051 | |
6751b71e PM |
2052 | return -EAGAIN; |
2053 | } | |
2054 | ||
3b6f9e5c | 2055 | /* |
cdd6c482 | 2056 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2057 | */ |
cdd6c482 | 2058 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2059 | struct perf_cpu_context *cpuctx, |
2060 | int can_add_hw) | |
2061 | { | |
2062 | /* | |
cdd6c482 | 2063 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2064 | */ |
d6f962b5 | 2065 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2066 | return 1; |
2067 | /* | |
2068 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2069 | * events can go on. |
3b6f9e5c PM |
2070 | */ |
2071 | if (cpuctx->exclusive) | |
2072 | return 0; | |
2073 | /* | |
2074 | * If this group is exclusive and there are already | |
cdd6c482 | 2075 | * events on the CPU, it can't go on. |
3b6f9e5c | 2076 | */ |
cdd6c482 | 2077 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2078 | return 0; |
2079 | /* | |
2080 | * Otherwise, try to add it if all previous groups were able | |
2081 | * to go on. | |
2082 | */ | |
2083 | return can_add_hw; | |
2084 | } | |
2085 | ||
cdd6c482 IM |
2086 | static void add_event_to_ctx(struct perf_event *event, |
2087 | struct perf_event_context *ctx) | |
53cfbf59 | 2088 | { |
4158755d SE |
2089 | u64 tstamp = perf_event_time(event); |
2090 | ||
cdd6c482 | 2091 | list_add_event(event, ctx); |
8a49542c | 2092 | perf_group_attach(event); |
4158755d SE |
2093 | event->tstamp_enabled = tstamp; |
2094 | event->tstamp_running = tstamp; | |
2095 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2096 | } |
2097 | ||
bd2afa49 PZ |
2098 | static void ctx_sched_out(struct perf_event_context *ctx, |
2099 | struct perf_cpu_context *cpuctx, | |
2100 | enum event_type_t event_type); | |
2c29ef0f PZ |
2101 | static void |
2102 | ctx_sched_in(struct perf_event_context *ctx, | |
2103 | struct perf_cpu_context *cpuctx, | |
2104 | enum event_type_t event_type, | |
2105 | struct task_struct *task); | |
fe4b04fa | 2106 | |
bd2afa49 PZ |
2107 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2108 | struct perf_event_context *ctx) | |
2109 | { | |
2110 | if (!cpuctx->task_ctx) | |
2111 | return; | |
2112 | ||
2113 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2114 | return; | |
2115 | ||
2116 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); | |
2117 | } | |
2118 | ||
dce5855b PZ |
2119 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2120 | struct perf_event_context *ctx, | |
2121 | struct task_struct *task) | |
2122 | { | |
2123 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2124 | if (ctx) | |
2125 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2126 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2127 | if (ctx) | |
2128 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2129 | } | |
2130 | ||
3e349507 PZ |
2131 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2132 | struct perf_event_context *task_ctx) | |
0017960f | 2133 | { |
3e349507 PZ |
2134 | perf_pmu_disable(cpuctx->ctx.pmu); |
2135 | if (task_ctx) | |
2136 | task_ctx_sched_out(cpuctx, task_ctx); | |
2137 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2138 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2139 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2140 | } |
2141 | ||
0793a61d | 2142 | /* |
cdd6c482 | 2143 | * Cross CPU call to install and enable a performance event |
682076ae | 2144 | * |
a096309b PZ |
2145 | * Very similar to remote_function() + event_function() but cannot assume that |
2146 | * things like ctx->is_active and cpuctx->task_ctx are set. | |
0793a61d | 2147 | */ |
fe4b04fa | 2148 | static int __perf_install_in_context(void *info) |
0793a61d | 2149 | { |
a096309b PZ |
2150 | struct perf_event *event = info; |
2151 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2152 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2153 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
a096309b PZ |
2154 | bool activate = true; |
2155 | int ret = 0; | |
0793a61d | 2156 | |
63b6da39 | 2157 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2158 | if (ctx->task) { |
b58f6b0d PZ |
2159 | raw_spin_lock(&ctx->lock); |
2160 | task_ctx = ctx; | |
a096309b PZ |
2161 | |
2162 | /* If we're on the wrong CPU, try again */ | |
2163 | if (task_cpu(ctx->task) != smp_processor_id()) { | |
2164 | ret = -ESRCH; | |
63b6da39 | 2165 | goto unlock; |
a096309b | 2166 | } |
b58f6b0d | 2167 | |
39a43640 | 2168 | /* |
a096309b PZ |
2169 | * If we're on the right CPU, see if the task we target is |
2170 | * current, if not we don't have to activate the ctx, a future | |
2171 | * context switch will do that for us. | |
39a43640 | 2172 | */ |
a096309b PZ |
2173 | if (ctx->task != current) |
2174 | activate = false; | |
2175 | else | |
2176 | WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx); | |
2177 | ||
63b6da39 PZ |
2178 | } else if (task_ctx) { |
2179 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2180 | } |
b58f6b0d | 2181 | |
a096309b PZ |
2182 | if (activate) { |
2183 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2184 | add_event_to_ctx(event, ctx); | |
2185 | ctx_resched(cpuctx, task_ctx); | |
2186 | } else { | |
2187 | add_event_to_ctx(event, ctx); | |
2188 | } | |
2189 | ||
63b6da39 | 2190 | unlock: |
2c29ef0f | 2191 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa | 2192 | |
a096309b | 2193 | return ret; |
0793a61d TG |
2194 | } |
2195 | ||
2196 | /* | |
a096309b PZ |
2197 | * Attach a performance event to a context. |
2198 | * | |
2199 | * Very similar to event_function_call, see comment there. | |
0793a61d TG |
2200 | */ |
2201 | static void | |
cdd6c482 IM |
2202 | perf_install_in_context(struct perf_event_context *ctx, |
2203 | struct perf_event *event, | |
0793a61d TG |
2204 | int cpu) |
2205 | { | |
a096309b | 2206 | struct task_struct *task = READ_ONCE(ctx->task); |
39a43640 | 2207 | |
fe4b04fa PZ |
2208 | lockdep_assert_held(&ctx->mutex); |
2209 | ||
c3f00c70 | 2210 | event->ctx = ctx; |
0cda4c02 YZ |
2211 | if (event->cpu != -1) |
2212 | event->cpu = cpu; | |
c3f00c70 | 2213 | |
a096309b PZ |
2214 | if (!task) { |
2215 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2216 | return; | |
2217 | } | |
2218 | ||
2219 | /* | |
2220 | * Should not happen, we validate the ctx is still alive before calling. | |
2221 | */ | |
2222 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) | |
2223 | return; | |
2224 | ||
39a43640 PZ |
2225 | /* |
2226 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2227 | * to be set in case this is the nr_events 0 -> 1 transition. | |
39a43640 | 2228 | */ |
a096309b | 2229 | again: |
63b6da39 | 2230 | /* |
a096309b PZ |
2231 | * Cannot use task_function_call() because we need to run on the task's |
2232 | * CPU regardless of whether its current or not. | |
63b6da39 | 2233 | */ |
a096309b PZ |
2234 | if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event)) |
2235 | return; | |
2236 | ||
2237 | raw_spin_lock_irq(&ctx->lock); | |
2238 | task = ctx->task; | |
84c4e620 | 2239 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
a096309b PZ |
2240 | /* |
2241 | * Cannot happen because we already checked above (which also | |
2242 | * cannot happen), and we hold ctx->mutex, which serializes us | |
2243 | * against perf_event_exit_task_context(). | |
2244 | */ | |
63b6da39 PZ |
2245 | raw_spin_unlock_irq(&ctx->lock); |
2246 | return; | |
2247 | } | |
39a43640 | 2248 | raw_spin_unlock_irq(&ctx->lock); |
39a43640 | 2249 | /* |
a096309b PZ |
2250 | * Since !ctx->is_active doesn't mean anything, we must IPI |
2251 | * unconditionally. | |
39a43640 | 2252 | */ |
a096309b | 2253 | goto again; |
0793a61d TG |
2254 | } |
2255 | ||
fa289bec | 2256 | /* |
cdd6c482 | 2257 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2258 | * Enabling the leader of a group effectively enables all |
2259 | * the group members that aren't explicitly disabled, so we | |
2260 | * have to update their ->tstamp_enabled also. | |
2261 | * Note: this works for group members as well as group leaders | |
2262 | * since the non-leader members' sibling_lists will be empty. | |
2263 | */ | |
1d9b482e | 2264 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2265 | { |
cdd6c482 | 2266 | struct perf_event *sub; |
4158755d | 2267 | u64 tstamp = perf_event_time(event); |
fa289bec | 2268 | |
cdd6c482 | 2269 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2270 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2271 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2272 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2273 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2274 | } |
fa289bec PM |
2275 | } |
2276 | ||
d859e29f | 2277 | /* |
cdd6c482 | 2278 | * Cross CPU call to enable a performance event |
d859e29f | 2279 | */ |
fae3fde6 PZ |
2280 | static void __perf_event_enable(struct perf_event *event, |
2281 | struct perf_cpu_context *cpuctx, | |
2282 | struct perf_event_context *ctx, | |
2283 | void *info) | |
04289bb9 | 2284 | { |
cdd6c482 | 2285 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2286 | struct perf_event_context *task_ctx; |
04289bb9 | 2287 | |
6e801e01 PZ |
2288 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2289 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2290 | return; |
3cbed429 | 2291 | |
bd2afa49 PZ |
2292 | if (ctx->is_active) |
2293 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2294 | ||
1d9b482e | 2295 | __perf_event_mark_enabled(event); |
04289bb9 | 2296 | |
fae3fde6 PZ |
2297 | if (!ctx->is_active) |
2298 | return; | |
2299 | ||
e5d1367f | 2300 | if (!event_filter_match(event)) { |
bd2afa49 | 2301 | if (is_cgroup_event(event)) |
e5d1367f | 2302 | perf_cgroup_defer_enabled(event); |
bd2afa49 | 2303 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); |
fae3fde6 | 2304 | return; |
e5d1367f | 2305 | } |
f4c4176f | 2306 | |
04289bb9 | 2307 | /* |
cdd6c482 | 2308 | * If the event is in a group and isn't the group leader, |
d859e29f | 2309 | * then don't put it on unless the group is on. |
04289bb9 | 2310 | */ |
bd2afa49 PZ |
2311 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) { |
2312 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
fae3fde6 | 2313 | return; |
bd2afa49 | 2314 | } |
fe4b04fa | 2315 | |
fae3fde6 PZ |
2316 | task_ctx = cpuctx->task_ctx; |
2317 | if (ctx->task) | |
2318 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2319 | |
fae3fde6 | 2320 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2321 | } |
2322 | ||
d859e29f | 2323 | /* |
cdd6c482 | 2324 | * Enable a event. |
c93f7669 | 2325 | * |
cdd6c482 IM |
2326 | * If event->ctx is a cloned context, callers must make sure that |
2327 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2328 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2329 | * perf_event_for_each_child or perf_event_for_each as described |
2330 | * for perf_event_disable. | |
d859e29f | 2331 | */ |
f63a8daa | 2332 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2333 | { |
cdd6c482 | 2334 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2335 | |
7b648018 | 2336 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2337 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2338 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2339 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2340 | return; |
2341 | } | |
2342 | ||
d859e29f | 2343 | /* |
cdd6c482 | 2344 | * If the event is in error state, clear that first. |
7b648018 PZ |
2345 | * |
2346 | * That way, if we see the event in error state below, we know that it | |
2347 | * has gone back into error state, as distinct from the task having | |
2348 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2349 | */ |
cdd6c482 IM |
2350 | if (event->state == PERF_EVENT_STATE_ERROR) |
2351 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2352 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2353 | |
fae3fde6 | 2354 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2355 | } |
f63a8daa PZ |
2356 | |
2357 | /* | |
2358 | * See perf_event_disable(); | |
2359 | */ | |
2360 | void perf_event_enable(struct perf_event *event) | |
2361 | { | |
2362 | struct perf_event_context *ctx; | |
2363 | ||
2364 | ctx = perf_event_ctx_lock(event); | |
2365 | _perf_event_enable(event); | |
2366 | perf_event_ctx_unlock(event, ctx); | |
2367 | } | |
dcfce4a0 | 2368 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2369 | |
375637bc AS |
2370 | struct stop_event_data { |
2371 | struct perf_event *event; | |
2372 | unsigned int restart; | |
2373 | }; | |
2374 | ||
95ff4ca2 AS |
2375 | static int __perf_event_stop(void *info) |
2376 | { | |
375637bc AS |
2377 | struct stop_event_data *sd = info; |
2378 | struct perf_event *event = sd->event; | |
95ff4ca2 | 2379 | |
375637bc | 2380 | /* if it's already INACTIVE, do nothing */ |
95ff4ca2 AS |
2381 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) |
2382 | return 0; | |
2383 | ||
2384 | /* matches smp_wmb() in event_sched_in() */ | |
2385 | smp_rmb(); | |
2386 | ||
2387 | /* | |
2388 | * There is a window with interrupts enabled before we get here, | |
2389 | * so we need to check again lest we try to stop another CPU's event. | |
2390 | */ | |
2391 | if (READ_ONCE(event->oncpu) != smp_processor_id()) | |
2392 | return -EAGAIN; | |
2393 | ||
2394 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2395 | ||
375637bc AS |
2396 | /* |
2397 | * May race with the actual stop (through perf_pmu_output_stop()), | |
2398 | * but it is only used for events with AUX ring buffer, and such | |
2399 | * events will refuse to restart because of rb::aux_mmap_count==0, | |
2400 | * see comments in perf_aux_output_begin(). | |
2401 | * | |
2402 | * Since this is happening on a event-local CPU, no trace is lost | |
2403 | * while restarting. | |
2404 | */ | |
2405 | if (sd->restart) | |
2406 | event->pmu->start(event, PERF_EF_START); | |
2407 | ||
95ff4ca2 AS |
2408 | return 0; |
2409 | } | |
2410 | ||
375637bc AS |
2411 | static int perf_event_restart(struct perf_event *event) |
2412 | { | |
2413 | struct stop_event_data sd = { | |
2414 | .event = event, | |
2415 | .restart = 1, | |
2416 | }; | |
2417 | int ret = 0; | |
2418 | ||
2419 | do { | |
2420 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) | |
2421 | return 0; | |
2422 | ||
2423 | /* matches smp_wmb() in event_sched_in() */ | |
2424 | smp_rmb(); | |
2425 | ||
2426 | /* | |
2427 | * We only want to restart ACTIVE events, so if the event goes | |
2428 | * inactive here (event->oncpu==-1), there's nothing more to do; | |
2429 | * fall through with ret==-ENXIO. | |
2430 | */ | |
2431 | ret = cpu_function_call(READ_ONCE(event->oncpu), | |
2432 | __perf_event_stop, &sd); | |
2433 | } while (ret == -EAGAIN); | |
2434 | ||
2435 | return ret; | |
2436 | } | |
2437 | ||
2438 | /* | |
2439 | * In order to contain the amount of racy and tricky in the address filter | |
2440 | * configuration management, it is a two part process: | |
2441 | * | |
2442 | * (p1) when userspace mappings change as a result of (1) or (2) or (3) below, | |
2443 | * we update the addresses of corresponding vmas in | |
2444 | * event::addr_filters_offs array and bump the event::addr_filters_gen; | |
2445 | * (p2) when an event is scheduled in (pmu::add), it calls | |
2446 | * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync() | |
2447 | * if the generation has changed since the previous call. | |
2448 | * | |
2449 | * If (p1) happens while the event is active, we restart it to force (p2). | |
2450 | * | |
2451 | * (1) perf_addr_filters_apply(): adjusting filters' offsets based on | |
2452 | * pre-existing mappings, called once when new filters arrive via SET_FILTER | |
2453 | * ioctl; | |
2454 | * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly | |
2455 | * registered mapping, called for every new mmap(), with mm::mmap_sem down | |
2456 | * for reading; | |
2457 | * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process | |
2458 | * of exec. | |
2459 | */ | |
2460 | void perf_event_addr_filters_sync(struct perf_event *event) | |
2461 | { | |
2462 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
2463 | ||
2464 | if (!has_addr_filter(event)) | |
2465 | return; | |
2466 | ||
2467 | raw_spin_lock(&ifh->lock); | |
2468 | if (event->addr_filters_gen != event->hw.addr_filters_gen) { | |
2469 | event->pmu->addr_filters_sync(event); | |
2470 | event->hw.addr_filters_gen = event->addr_filters_gen; | |
2471 | } | |
2472 | raw_spin_unlock(&ifh->lock); | |
2473 | } | |
2474 | EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync); | |
2475 | ||
f63a8daa | 2476 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2477 | { |
2023b359 | 2478 | /* |
cdd6c482 | 2479 | * not supported on inherited events |
2023b359 | 2480 | */ |
2e939d1d | 2481 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2482 | return -EINVAL; |
2483 | ||
cdd6c482 | 2484 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2485 | _perf_event_enable(event); |
2023b359 PZ |
2486 | |
2487 | return 0; | |
79f14641 | 2488 | } |
f63a8daa PZ |
2489 | |
2490 | /* | |
2491 | * See perf_event_disable() | |
2492 | */ | |
2493 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2494 | { | |
2495 | struct perf_event_context *ctx; | |
2496 | int ret; | |
2497 | ||
2498 | ctx = perf_event_ctx_lock(event); | |
2499 | ret = _perf_event_refresh(event, refresh); | |
2500 | perf_event_ctx_unlock(event, ctx); | |
2501 | ||
2502 | return ret; | |
2503 | } | |
26ca5c11 | 2504 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2505 | |
5b0311e1 FW |
2506 | static void ctx_sched_out(struct perf_event_context *ctx, |
2507 | struct perf_cpu_context *cpuctx, | |
2508 | enum event_type_t event_type) | |
235c7fc7 | 2509 | { |
db24d33e | 2510 | int is_active = ctx->is_active; |
c994d613 | 2511 | struct perf_event *event; |
235c7fc7 | 2512 | |
c994d613 | 2513 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2514 | |
39a43640 PZ |
2515 | if (likely(!ctx->nr_events)) { |
2516 | /* | |
2517 | * See __perf_remove_from_context(). | |
2518 | */ | |
2519 | WARN_ON_ONCE(ctx->is_active); | |
2520 | if (ctx->task) | |
2521 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2522 | return; |
39a43640 PZ |
2523 | } |
2524 | ||
db24d33e | 2525 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2526 | if (!(ctx->is_active & EVENT_ALL)) |
2527 | ctx->is_active = 0; | |
2528 | ||
63e30d3e PZ |
2529 | if (ctx->task) { |
2530 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2531 | if (!ctx->is_active) | |
2532 | cpuctx->task_ctx = NULL; | |
2533 | } | |
facc4307 | 2534 | |
8fdc6539 PZ |
2535 | /* |
2536 | * Always update time if it was set; not only when it changes. | |
2537 | * Otherwise we can 'forget' to update time for any but the last | |
2538 | * context we sched out. For example: | |
2539 | * | |
2540 | * ctx_sched_out(.event_type = EVENT_FLEXIBLE) | |
2541 | * ctx_sched_out(.event_type = EVENT_PINNED) | |
2542 | * | |
2543 | * would only update time for the pinned events. | |
2544 | */ | |
3cbaa590 PZ |
2545 | if (is_active & EVENT_TIME) { |
2546 | /* update (and stop) ctx time */ | |
2547 | update_context_time(ctx); | |
2548 | update_cgrp_time_from_cpuctx(cpuctx); | |
2549 | } | |
2550 | ||
8fdc6539 PZ |
2551 | is_active ^= ctx->is_active; /* changed bits */ |
2552 | ||
3cbaa590 | 2553 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) |
facc4307 | 2554 | return; |
5b0311e1 | 2555 | |
075e0b00 | 2556 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2557 | if (is_active & EVENT_PINNED) { |
889ff015 FW |
2558 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2559 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2560 | } |
889ff015 | 2561 | |
3cbaa590 | 2562 | if (is_active & EVENT_FLEXIBLE) { |
889ff015 | 2563 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2564 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2565 | } |
1b9a644f | 2566 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2567 | } |
2568 | ||
564c2b21 | 2569 | /* |
5a3126d4 PZ |
2570 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2571 | * cloned from the same version of the same context. | |
2572 | * | |
2573 | * Equivalence is measured using a generation number in the context that is | |
2574 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2575 | * and list_del_event(). | |
564c2b21 | 2576 | */ |
cdd6c482 IM |
2577 | static int context_equiv(struct perf_event_context *ctx1, |
2578 | struct perf_event_context *ctx2) | |
564c2b21 | 2579 | { |
211de6eb PZ |
2580 | lockdep_assert_held(&ctx1->lock); |
2581 | lockdep_assert_held(&ctx2->lock); | |
2582 | ||
5a3126d4 PZ |
2583 | /* Pinning disables the swap optimization */ |
2584 | if (ctx1->pin_count || ctx2->pin_count) | |
2585 | return 0; | |
2586 | ||
2587 | /* If ctx1 is the parent of ctx2 */ | |
2588 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2589 | return 1; | |
2590 | ||
2591 | /* If ctx2 is the parent of ctx1 */ | |
2592 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2593 | return 1; | |
2594 | ||
2595 | /* | |
2596 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2597 | * hierarchy, see perf_event_init_context(). | |
2598 | */ | |
2599 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2600 | ctx1->parent_gen == ctx2->parent_gen) | |
2601 | return 1; | |
2602 | ||
2603 | /* Unmatched */ | |
2604 | return 0; | |
564c2b21 PM |
2605 | } |
2606 | ||
cdd6c482 IM |
2607 | static void __perf_event_sync_stat(struct perf_event *event, |
2608 | struct perf_event *next_event) | |
bfbd3381 PZ |
2609 | { |
2610 | u64 value; | |
2611 | ||
cdd6c482 | 2612 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2613 | return; |
2614 | ||
2615 | /* | |
cdd6c482 | 2616 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2617 | * because we're in the middle of a context switch and have IRQs |
2618 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2619 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2620 | * don't need to use it. |
2621 | */ | |
cdd6c482 IM |
2622 | switch (event->state) { |
2623 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2624 | event->pmu->read(event); |
2625 | /* fall-through */ | |
bfbd3381 | 2626 | |
cdd6c482 IM |
2627 | case PERF_EVENT_STATE_INACTIVE: |
2628 | update_event_times(event); | |
bfbd3381 PZ |
2629 | break; |
2630 | ||
2631 | default: | |
2632 | break; | |
2633 | } | |
2634 | ||
2635 | /* | |
cdd6c482 | 2636 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2637 | * values when we flip the contexts. |
2638 | */ | |
e7850595 PZ |
2639 | value = local64_read(&next_event->count); |
2640 | value = local64_xchg(&event->count, value); | |
2641 | local64_set(&next_event->count, value); | |
bfbd3381 | 2642 | |
cdd6c482 IM |
2643 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2644 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2645 | |
bfbd3381 | 2646 | /* |
19d2e755 | 2647 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2648 | */ |
cdd6c482 IM |
2649 | perf_event_update_userpage(event); |
2650 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2651 | } |
2652 | ||
cdd6c482 IM |
2653 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2654 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2655 | { |
cdd6c482 | 2656 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2657 | |
2658 | if (!ctx->nr_stat) | |
2659 | return; | |
2660 | ||
02ffdbc8 PZ |
2661 | update_context_time(ctx); |
2662 | ||
cdd6c482 IM |
2663 | event = list_first_entry(&ctx->event_list, |
2664 | struct perf_event, event_entry); | |
bfbd3381 | 2665 | |
cdd6c482 IM |
2666 | next_event = list_first_entry(&next_ctx->event_list, |
2667 | struct perf_event, event_entry); | |
bfbd3381 | 2668 | |
cdd6c482 IM |
2669 | while (&event->event_entry != &ctx->event_list && |
2670 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2671 | |
cdd6c482 | 2672 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2673 | |
cdd6c482 IM |
2674 | event = list_next_entry(event, event_entry); |
2675 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2676 | } |
2677 | } | |
2678 | ||
fe4b04fa PZ |
2679 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2680 | struct task_struct *next) | |
0793a61d | 2681 | { |
8dc85d54 | 2682 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2683 | struct perf_event_context *next_ctx; |
5a3126d4 | 2684 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2685 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2686 | int do_switch = 1; |
0793a61d | 2687 | |
108b02cf PZ |
2688 | if (likely(!ctx)) |
2689 | return; | |
10989fb2 | 2690 | |
108b02cf PZ |
2691 | cpuctx = __get_cpu_context(ctx); |
2692 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2693 | return; |
2694 | ||
c93f7669 | 2695 | rcu_read_lock(); |
8dc85d54 | 2696 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2697 | if (!next_ctx) |
2698 | goto unlock; | |
2699 | ||
2700 | parent = rcu_dereference(ctx->parent_ctx); | |
2701 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2702 | ||
2703 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2704 | if (!parent && !next_parent) |
5a3126d4 PZ |
2705 | goto unlock; |
2706 | ||
2707 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2708 | /* |
2709 | * Looks like the two contexts are clones, so we might be | |
2710 | * able to optimize the context switch. We lock both | |
2711 | * contexts and check that they are clones under the | |
2712 | * lock (including re-checking that neither has been | |
2713 | * uncloned in the meantime). It doesn't matter which | |
2714 | * order we take the locks because no other cpu could | |
2715 | * be trying to lock both of these tasks. | |
2716 | */ | |
e625cce1 TG |
2717 | raw_spin_lock(&ctx->lock); |
2718 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2719 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2720 | WRITE_ONCE(ctx->task, next); |
2721 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2722 | |
2723 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2724 | ||
63b6da39 PZ |
2725 | /* |
2726 | * RCU_INIT_POINTER here is safe because we've not | |
2727 | * modified the ctx and the above modification of | |
2728 | * ctx->task and ctx->task_ctx_data are immaterial | |
2729 | * since those values are always verified under | |
2730 | * ctx->lock which we're now holding. | |
2731 | */ | |
2732 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2733 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2734 | ||
c93f7669 | 2735 | do_switch = 0; |
bfbd3381 | 2736 | |
cdd6c482 | 2737 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2738 | } |
e625cce1 TG |
2739 | raw_spin_unlock(&next_ctx->lock); |
2740 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2741 | } |
5a3126d4 | 2742 | unlock: |
c93f7669 | 2743 | rcu_read_unlock(); |
564c2b21 | 2744 | |
c93f7669 | 2745 | if (do_switch) { |
facc4307 | 2746 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2747 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2748 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2749 | } |
0793a61d TG |
2750 | } |
2751 | ||
ba532500 YZ |
2752 | void perf_sched_cb_dec(struct pmu *pmu) |
2753 | { | |
2754 | this_cpu_dec(perf_sched_cb_usages); | |
2755 | } | |
2756 | ||
2757 | void perf_sched_cb_inc(struct pmu *pmu) | |
2758 | { | |
2759 | this_cpu_inc(perf_sched_cb_usages); | |
2760 | } | |
2761 | ||
2762 | /* | |
2763 | * This function provides the context switch callback to the lower code | |
2764 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2765 | */ | |
2766 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2767 | struct task_struct *next, | |
2768 | bool sched_in) | |
2769 | { | |
2770 | struct perf_cpu_context *cpuctx; | |
2771 | struct pmu *pmu; | |
2772 | unsigned long flags; | |
2773 | ||
2774 | if (prev == next) | |
2775 | return; | |
2776 | ||
2777 | local_irq_save(flags); | |
2778 | ||
2779 | rcu_read_lock(); | |
2780 | ||
2781 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2782 | if (pmu->sched_task) { | |
2783 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2784 | ||
2785 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2786 | ||
2787 | perf_pmu_disable(pmu); | |
2788 | ||
2789 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2790 | ||
2791 | perf_pmu_enable(pmu); | |
2792 | ||
2793 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2794 | } | |
2795 | } | |
2796 | ||
2797 | rcu_read_unlock(); | |
2798 | ||
2799 | local_irq_restore(flags); | |
2800 | } | |
2801 | ||
45ac1403 AH |
2802 | static void perf_event_switch(struct task_struct *task, |
2803 | struct task_struct *next_prev, bool sched_in); | |
2804 | ||
8dc85d54 PZ |
2805 | #define for_each_task_context_nr(ctxn) \ |
2806 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2807 | ||
2808 | /* | |
2809 | * Called from scheduler to remove the events of the current task, | |
2810 | * with interrupts disabled. | |
2811 | * | |
2812 | * We stop each event and update the event value in event->count. | |
2813 | * | |
2814 | * This does not protect us against NMI, but disable() | |
2815 | * sets the disabled bit in the control field of event _before_ | |
2816 | * accessing the event control register. If a NMI hits, then it will | |
2817 | * not restart the event. | |
2818 | */ | |
ab0cce56 JO |
2819 | void __perf_event_task_sched_out(struct task_struct *task, |
2820 | struct task_struct *next) | |
8dc85d54 PZ |
2821 | { |
2822 | int ctxn; | |
2823 | ||
ba532500 YZ |
2824 | if (__this_cpu_read(perf_sched_cb_usages)) |
2825 | perf_pmu_sched_task(task, next, false); | |
2826 | ||
45ac1403 AH |
2827 | if (atomic_read(&nr_switch_events)) |
2828 | perf_event_switch(task, next, false); | |
2829 | ||
8dc85d54 PZ |
2830 | for_each_task_context_nr(ctxn) |
2831 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2832 | |
2833 | /* | |
2834 | * if cgroup events exist on this CPU, then we need | |
2835 | * to check if we have to switch out PMU state. | |
2836 | * cgroup event are system-wide mode only | |
2837 | */ | |
4a32fea9 | 2838 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2839 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2840 | } |
2841 | ||
5b0311e1 FW |
2842 | /* |
2843 | * Called with IRQs disabled | |
2844 | */ | |
2845 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2846 | enum event_type_t event_type) | |
2847 | { | |
2848 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2849 | } |
2850 | ||
235c7fc7 | 2851 | static void |
5b0311e1 | 2852 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2853 | struct perf_cpu_context *cpuctx) |
0793a61d | 2854 | { |
cdd6c482 | 2855 | struct perf_event *event; |
0793a61d | 2856 | |
889ff015 FW |
2857 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2858 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2859 | continue; |
5632ab12 | 2860 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2861 | continue; |
2862 | ||
e5d1367f SE |
2863 | /* may need to reset tstamp_enabled */ |
2864 | if (is_cgroup_event(event)) | |
2865 | perf_cgroup_mark_enabled(event, ctx); | |
2866 | ||
8c9ed8e1 | 2867 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2868 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2869 | |
2870 | /* | |
2871 | * If this pinned group hasn't been scheduled, | |
2872 | * put it in error state. | |
2873 | */ | |
cdd6c482 IM |
2874 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2875 | update_group_times(event); | |
2876 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2877 | } |
3b6f9e5c | 2878 | } |
5b0311e1 FW |
2879 | } |
2880 | ||
2881 | static void | |
2882 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2883 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2884 | { |
2885 | struct perf_event *event; | |
2886 | int can_add_hw = 1; | |
3b6f9e5c | 2887 | |
889ff015 FW |
2888 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2889 | /* Ignore events in OFF or ERROR state */ | |
2890 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2891 | continue; |
04289bb9 IM |
2892 | /* |
2893 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2894 | * of events: |
04289bb9 | 2895 | */ |
5632ab12 | 2896 | if (!event_filter_match(event)) |
0793a61d TG |
2897 | continue; |
2898 | ||
e5d1367f SE |
2899 | /* may need to reset tstamp_enabled */ |
2900 | if (is_cgroup_event(event)) | |
2901 | perf_cgroup_mark_enabled(event, ctx); | |
2902 | ||
9ed6060d | 2903 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2904 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2905 | can_add_hw = 0; |
9ed6060d | 2906 | } |
0793a61d | 2907 | } |
5b0311e1 FW |
2908 | } |
2909 | ||
2910 | static void | |
2911 | ctx_sched_in(struct perf_event_context *ctx, | |
2912 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2913 | enum event_type_t event_type, |
2914 | struct task_struct *task) | |
5b0311e1 | 2915 | { |
db24d33e | 2916 | int is_active = ctx->is_active; |
c994d613 PZ |
2917 | u64 now; |
2918 | ||
2919 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2920 | |
5b0311e1 | 2921 | if (likely(!ctx->nr_events)) |
facc4307 | 2922 | return; |
5b0311e1 | 2923 | |
3cbaa590 | 2924 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
2925 | if (ctx->task) { |
2926 | if (!is_active) | |
2927 | cpuctx->task_ctx = ctx; | |
2928 | else | |
2929 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2930 | } | |
2931 | ||
3cbaa590 PZ |
2932 | is_active ^= ctx->is_active; /* changed bits */ |
2933 | ||
2934 | if (is_active & EVENT_TIME) { | |
2935 | /* start ctx time */ | |
2936 | now = perf_clock(); | |
2937 | ctx->timestamp = now; | |
2938 | perf_cgroup_set_timestamp(task, ctx); | |
2939 | } | |
2940 | ||
5b0311e1 FW |
2941 | /* |
2942 | * First go through the list and put on any pinned groups | |
2943 | * in order to give them the best chance of going on. | |
2944 | */ | |
3cbaa590 | 2945 | if (is_active & EVENT_PINNED) |
6e37738a | 2946 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2947 | |
2948 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 2949 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 2950 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2951 | } |
2952 | ||
329c0e01 | 2953 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2954 | enum event_type_t event_type, |
2955 | struct task_struct *task) | |
329c0e01 FW |
2956 | { |
2957 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2958 | ||
e5d1367f | 2959 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2960 | } |
2961 | ||
e5d1367f SE |
2962 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2963 | struct task_struct *task) | |
235c7fc7 | 2964 | { |
108b02cf | 2965 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2966 | |
108b02cf | 2967 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2968 | if (cpuctx->task_ctx == ctx) |
2969 | return; | |
2970 | ||
facc4307 | 2971 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2972 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2973 | /* |
2974 | * We want to keep the following priority order: | |
2975 | * cpu pinned (that don't need to move), task pinned, | |
2976 | * cpu flexible, task flexible. | |
2977 | */ | |
2978 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2979 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2980 | perf_pmu_enable(ctx->pmu); |
2981 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2982 | } |
2983 | ||
8dc85d54 PZ |
2984 | /* |
2985 | * Called from scheduler to add the events of the current task | |
2986 | * with interrupts disabled. | |
2987 | * | |
2988 | * We restore the event value and then enable it. | |
2989 | * | |
2990 | * This does not protect us against NMI, but enable() | |
2991 | * sets the enabled bit in the control field of event _before_ | |
2992 | * accessing the event control register. If a NMI hits, then it will | |
2993 | * keep the event running. | |
2994 | */ | |
ab0cce56 JO |
2995 | void __perf_event_task_sched_in(struct task_struct *prev, |
2996 | struct task_struct *task) | |
8dc85d54 PZ |
2997 | { |
2998 | struct perf_event_context *ctx; | |
2999 | int ctxn; | |
3000 | ||
7e41d177 PZ |
3001 | /* |
3002 | * If cgroup events exist on this CPU, then we need to check if we have | |
3003 | * to switch in PMU state; cgroup event are system-wide mode only. | |
3004 | * | |
3005 | * Since cgroup events are CPU events, we must schedule these in before | |
3006 | * we schedule in the task events. | |
3007 | */ | |
3008 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
3009 | perf_cgroup_sched_in(prev, task); | |
3010 | ||
8dc85d54 PZ |
3011 | for_each_task_context_nr(ctxn) { |
3012 | ctx = task->perf_event_ctxp[ctxn]; | |
3013 | if (likely(!ctx)) | |
3014 | continue; | |
3015 | ||
e5d1367f | 3016 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 3017 | } |
d010b332 | 3018 | |
45ac1403 AH |
3019 | if (atomic_read(&nr_switch_events)) |
3020 | perf_event_switch(task, prev, true); | |
3021 | ||
ba532500 YZ |
3022 | if (__this_cpu_read(perf_sched_cb_usages)) |
3023 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
3024 | } |
3025 | ||
abd50713 PZ |
3026 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
3027 | { | |
3028 | u64 frequency = event->attr.sample_freq; | |
3029 | u64 sec = NSEC_PER_SEC; | |
3030 | u64 divisor, dividend; | |
3031 | ||
3032 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
3033 | ||
3034 | count_fls = fls64(count); | |
3035 | nsec_fls = fls64(nsec); | |
3036 | frequency_fls = fls64(frequency); | |
3037 | sec_fls = 30; | |
3038 | ||
3039 | /* | |
3040 | * We got @count in @nsec, with a target of sample_freq HZ | |
3041 | * the target period becomes: | |
3042 | * | |
3043 | * @count * 10^9 | |
3044 | * period = ------------------- | |
3045 | * @nsec * sample_freq | |
3046 | * | |
3047 | */ | |
3048 | ||
3049 | /* | |
3050 | * Reduce accuracy by one bit such that @a and @b converge | |
3051 | * to a similar magnitude. | |
3052 | */ | |
fe4b04fa | 3053 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
3054 | do { \ |
3055 | if (a##_fls > b##_fls) { \ | |
3056 | a >>= 1; \ | |
3057 | a##_fls--; \ | |
3058 | } else { \ | |
3059 | b >>= 1; \ | |
3060 | b##_fls--; \ | |
3061 | } \ | |
3062 | } while (0) | |
3063 | ||
3064 | /* | |
3065 | * Reduce accuracy until either term fits in a u64, then proceed with | |
3066 | * the other, so that finally we can do a u64/u64 division. | |
3067 | */ | |
3068 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
3069 | REDUCE_FLS(nsec, frequency); | |
3070 | REDUCE_FLS(sec, count); | |
3071 | } | |
3072 | ||
3073 | if (count_fls + sec_fls > 64) { | |
3074 | divisor = nsec * frequency; | |
3075 | ||
3076 | while (count_fls + sec_fls > 64) { | |
3077 | REDUCE_FLS(count, sec); | |
3078 | divisor >>= 1; | |
3079 | } | |
3080 | ||
3081 | dividend = count * sec; | |
3082 | } else { | |
3083 | dividend = count * sec; | |
3084 | ||
3085 | while (nsec_fls + frequency_fls > 64) { | |
3086 | REDUCE_FLS(nsec, frequency); | |
3087 | dividend >>= 1; | |
3088 | } | |
3089 | ||
3090 | divisor = nsec * frequency; | |
3091 | } | |
3092 | ||
f6ab91ad PZ |
3093 | if (!divisor) |
3094 | return dividend; | |
3095 | ||
abd50713 PZ |
3096 | return div64_u64(dividend, divisor); |
3097 | } | |
3098 | ||
e050e3f0 SE |
3099 | static DEFINE_PER_CPU(int, perf_throttled_count); |
3100 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
3101 | ||
f39d47ff | 3102 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 3103 | { |
cdd6c482 | 3104 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 3105 | s64 period, sample_period; |
bd2b5b12 PZ |
3106 | s64 delta; |
3107 | ||
abd50713 | 3108 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
3109 | |
3110 | delta = (s64)(period - hwc->sample_period); | |
3111 | delta = (delta + 7) / 8; /* low pass filter */ | |
3112 | ||
3113 | sample_period = hwc->sample_period + delta; | |
3114 | ||
3115 | if (!sample_period) | |
3116 | sample_period = 1; | |
3117 | ||
bd2b5b12 | 3118 | hwc->sample_period = sample_period; |
abd50713 | 3119 | |
e7850595 | 3120 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
3121 | if (disable) |
3122 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3123 | ||
e7850595 | 3124 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
3125 | |
3126 | if (disable) | |
3127 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 3128 | } |
bd2b5b12 PZ |
3129 | } |
3130 | ||
e050e3f0 SE |
3131 | /* |
3132 | * combine freq adjustment with unthrottling to avoid two passes over the | |
3133 | * events. At the same time, make sure, having freq events does not change | |
3134 | * the rate of unthrottling as that would introduce bias. | |
3135 | */ | |
3136 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
3137 | int needs_unthr) | |
60db5e09 | 3138 | { |
cdd6c482 IM |
3139 | struct perf_event *event; |
3140 | struct hw_perf_event *hwc; | |
e050e3f0 | 3141 | u64 now, period = TICK_NSEC; |
abd50713 | 3142 | s64 delta; |
60db5e09 | 3143 | |
e050e3f0 SE |
3144 | /* |
3145 | * only need to iterate over all events iff: | |
3146 | * - context have events in frequency mode (needs freq adjust) | |
3147 | * - there are events to unthrottle on this cpu | |
3148 | */ | |
3149 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
3150 | return; |
3151 | ||
e050e3f0 | 3152 | raw_spin_lock(&ctx->lock); |
f39d47ff | 3153 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 3154 | |
03541f8b | 3155 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 3156 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
3157 | continue; |
3158 | ||
5632ab12 | 3159 | if (!event_filter_match(event)) |
5d27c23d PZ |
3160 | continue; |
3161 | ||
44377277 AS |
3162 | perf_pmu_disable(event->pmu); |
3163 | ||
cdd6c482 | 3164 | hwc = &event->hw; |
6a24ed6c | 3165 | |
ae23bff1 | 3166 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 3167 | hwc->interrupts = 0; |
cdd6c482 | 3168 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3169 | event->pmu->start(event, 0); |
a78ac325 PZ |
3170 | } |
3171 | ||
cdd6c482 | 3172 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3173 | goto next; |
60db5e09 | 3174 | |
e050e3f0 SE |
3175 | /* |
3176 | * stop the event and update event->count | |
3177 | */ | |
3178 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3179 | ||
e7850595 | 3180 | now = local64_read(&event->count); |
abd50713 PZ |
3181 | delta = now - hwc->freq_count_stamp; |
3182 | hwc->freq_count_stamp = now; | |
60db5e09 | 3183 | |
e050e3f0 SE |
3184 | /* |
3185 | * restart the event | |
3186 | * reload only if value has changed | |
f39d47ff SE |
3187 | * we have stopped the event so tell that |
3188 | * to perf_adjust_period() to avoid stopping it | |
3189 | * twice. | |
e050e3f0 | 3190 | */ |
abd50713 | 3191 | if (delta > 0) |
f39d47ff | 3192 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3193 | |
3194 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3195 | next: |
3196 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3197 | } |
e050e3f0 | 3198 | |
f39d47ff | 3199 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3200 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3201 | } |
3202 | ||
235c7fc7 | 3203 | /* |
cdd6c482 | 3204 | * Round-robin a context's events: |
235c7fc7 | 3205 | */ |
cdd6c482 | 3206 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3207 | { |
dddd3379 TG |
3208 | /* |
3209 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3210 | * disabled by the inheritance code. | |
3211 | */ | |
3212 | if (!ctx->rotate_disable) | |
3213 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3214 | } |
3215 | ||
9e630205 | 3216 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3217 | { |
8dc85d54 | 3218 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3219 | int rotate = 0; |
7fc23a53 | 3220 | |
b5ab4cd5 | 3221 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3222 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3223 | rotate = 1; | |
3224 | } | |
235c7fc7 | 3225 | |
8dc85d54 | 3226 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3227 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3228 | if (ctx->nr_events != ctx->nr_active) |
3229 | rotate = 1; | |
3230 | } | |
9717e6cd | 3231 | |
e050e3f0 | 3232 | if (!rotate) |
0f5a2601 PZ |
3233 | goto done; |
3234 | ||
facc4307 | 3235 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3236 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3237 | |
e050e3f0 SE |
3238 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3239 | if (ctx) | |
3240 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3241 | |
e050e3f0 SE |
3242 | rotate_ctx(&cpuctx->ctx); |
3243 | if (ctx) | |
3244 | rotate_ctx(ctx); | |
235c7fc7 | 3245 | |
e050e3f0 | 3246 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3247 | |
0f5a2601 PZ |
3248 | perf_pmu_enable(cpuctx->ctx.pmu); |
3249 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3250 | done: |
9e630205 SE |
3251 | |
3252 | return rotate; | |
e9d2b064 PZ |
3253 | } |
3254 | ||
3255 | void perf_event_task_tick(void) | |
3256 | { | |
2fde4f94 MR |
3257 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3258 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3259 | int throttled; |
b5ab4cd5 | 3260 | |
e9d2b064 PZ |
3261 | WARN_ON(!irqs_disabled()); |
3262 | ||
e050e3f0 SE |
3263 | __this_cpu_inc(perf_throttled_seq); |
3264 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
555e0c1e | 3265 | tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
e050e3f0 | 3266 | |
2fde4f94 | 3267 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3268 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3269 | } |
3270 | ||
889ff015 FW |
3271 | static int event_enable_on_exec(struct perf_event *event, |
3272 | struct perf_event_context *ctx) | |
3273 | { | |
3274 | if (!event->attr.enable_on_exec) | |
3275 | return 0; | |
3276 | ||
3277 | event->attr.enable_on_exec = 0; | |
3278 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3279 | return 0; | |
3280 | ||
1d9b482e | 3281 | __perf_event_mark_enabled(event); |
889ff015 FW |
3282 | |
3283 | return 1; | |
3284 | } | |
3285 | ||
57e7986e | 3286 | /* |
cdd6c482 | 3287 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3288 | * This expects task == current. |
3289 | */ | |
c1274499 | 3290 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3291 | { |
c1274499 | 3292 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3293 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3294 | struct perf_event *event; |
57e7986e PM |
3295 | unsigned long flags; |
3296 | int enabled = 0; | |
3297 | ||
3298 | local_irq_save(flags); | |
c1274499 | 3299 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3300 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3301 | goto out; |
3302 | ||
3e349507 PZ |
3303 | cpuctx = __get_cpu_context(ctx); |
3304 | perf_ctx_lock(cpuctx, ctx); | |
7fce2509 | 3305 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
3e349507 PZ |
3306 | list_for_each_entry(event, &ctx->event_list, event_entry) |
3307 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3308 | |
3309 | /* | |
3e349507 | 3310 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3311 | */ |
3e349507 | 3312 | if (enabled) { |
211de6eb | 3313 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3314 | ctx_resched(cpuctx, ctx); |
3315 | } | |
3316 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3317 | |
9ed6060d | 3318 | out: |
57e7986e | 3319 | local_irq_restore(flags); |
211de6eb PZ |
3320 | |
3321 | if (clone_ctx) | |
3322 | put_ctx(clone_ctx); | |
57e7986e PM |
3323 | } |
3324 | ||
0492d4c5 PZ |
3325 | struct perf_read_data { |
3326 | struct perf_event *event; | |
3327 | bool group; | |
7d88962e | 3328 | int ret; |
0492d4c5 PZ |
3329 | }; |
3330 | ||
0793a61d | 3331 | /* |
cdd6c482 | 3332 | * Cross CPU call to read the hardware event |
0793a61d | 3333 | */ |
cdd6c482 | 3334 | static void __perf_event_read(void *info) |
0793a61d | 3335 | { |
0492d4c5 PZ |
3336 | struct perf_read_data *data = info; |
3337 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3338 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3339 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3340 | struct pmu *pmu = event->pmu; |
621a01ea | 3341 | |
e1ac3614 PM |
3342 | /* |
3343 | * If this is a task context, we need to check whether it is | |
3344 | * the current task context of this cpu. If not it has been | |
3345 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3346 | * event->count would have been updated to a recent sample |
3347 | * when the event was scheduled out. | |
e1ac3614 PM |
3348 | */ |
3349 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3350 | return; | |
3351 | ||
e625cce1 | 3352 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3353 | if (ctx->is_active) { |
542e72fc | 3354 | update_context_time(ctx); |
e5d1367f SE |
3355 | update_cgrp_time_from_event(event); |
3356 | } | |
0492d4c5 | 3357 | |
cdd6c482 | 3358 | update_event_times(event); |
4a00c16e SB |
3359 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3360 | goto unlock; | |
0492d4c5 | 3361 | |
4a00c16e SB |
3362 | if (!data->group) { |
3363 | pmu->read(event); | |
3364 | data->ret = 0; | |
0492d4c5 | 3365 | goto unlock; |
4a00c16e SB |
3366 | } |
3367 | ||
3368 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3369 | ||
3370 | pmu->read(event); | |
0492d4c5 PZ |
3371 | |
3372 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3373 | update_event_times(sub); | |
4a00c16e SB |
3374 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3375 | /* | |
3376 | * Use sibling's PMU rather than @event's since | |
3377 | * sibling could be on different (eg: software) PMU. | |
3378 | */ | |
0492d4c5 | 3379 | sub->pmu->read(sub); |
4a00c16e | 3380 | } |
0492d4c5 | 3381 | } |
4a00c16e SB |
3382 | |
3383 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3384 | |
3385 | unlock: | |
e625cce1 | 3386 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3387 | } |
3388 | ||
b5e58793 PZ |
3389 | static inline u64 perf_event_count(struct perf_event *event) |
3390 | { | |
eacd3ecc MF |
3391 | if (event->pmu->count) |
3392 | return event->pmu->count(event); | |
3393 | ||
3394 | return __perf_event_count(event); | |
b5e58793 PZ |
3395 | } |
3396 | ||
ffe8690c KX |
3397 | /* |
3398 | * NMI-safe method to read a local event, that is an event that | |
3399 | * is: | |
3400 | * - either for the current task, or for this CPU | |
3401 | * - does not have inherit set, for inherited task events | |
3402 | * will not be local and we cannot read them atomically | |
3403 | * - must not have a pmu::count method | |
3404 | */ | |
3405 | u64 perf_event_read_local(struct perf_event *event) | |
3406 | { | |
3407 | unsigned long flags; | |
3408 | u64 val; | |
3409 | ||
3410 | /* | |
3411 | * Disabling interrupts avoids all counter scheduling (context | |
3412 | * switches, timer based rotation and IPIs). | |
3413 | */ | |
3414 | local_irq_save(flags); | |
3415 | ||
3416 | /* If this is a per-task event, it must be for current */ | |
3417 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3418 | event->hw.target != current); | |
3419 | ||
3420 | /* If this is a per-CPU event, it must be for this CPU */ | |
3421 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3422 | event->cpu != smp_processor_id()); | |
3423 | ||
3424 | /* | |
3425 | * It must not be an event with inherit set, we cannot read | |
3426 | * all child counters from atomic context. | |
3427 | */ | |
3428 | WARN_ON_ONCE(event->attr.inherit); | |
3429 | ||
3430 | /* | |
3431 | * It must not have a pmu::count method, those are not | |
3432 | * NMI safe. | |
3433 | */ | |
3434 | WARN_ON_ONCE(event->pmu->count); | |
3435 | ||
3436 | /* | |
3437 | * If the event is currently on this CPU, its either a per-task event, | |
3438 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3439 | * oncpu == -1). | |
3440 | */ | |
3441 | if (event->oncpu == smp_processor_id()) | |
3442 | event->pmu->read(event); | |
3443 | ||
3444 | val = local64_read(&event->count); | |
3445 | local_irq_restore(flags); | |
3446 | ||
3447 | return val; | |
3448 | } | |
3449 | ||
7d88962e | 3450 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3451 | { |
7d88962e SB |
3452 | int ret = 0; |
3453 | ||
0793a61d | 3454 | /* |
cdd6c482 IM |
3455 | * If event is enabled and currently active on a CPU, update the |
3456 | * value in the event structure: | |
0793a61d | 3457 | */ |
cdd6c482 | 3458 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3459 | struct perf_read_data data = { |
3460 | .event = event, | |
3461 | .group = group, | |
7d88962e | 3462 | .ret = 0, |
0492d4c5 | 3463 | }; |
cdd6c482 | 3464 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3465 | __perf_event_read, &data, 1); |
7d88962e | 3466 | ret = data.ret; |
cdd6c482 | 3467 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3468 | struct perf_event_context *ctx = event->ctx; |
3469 | unsigned long flags; | |
3470 | ||
e625cce1 | 3471 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3472 | /* |
3473 | * may read while context is not active | |
3474 | * (e.g., thread is blocked), in that case | |
3475 | * we cannot update context time | |
3476 | */ | |
e5d1367f | 3477 | if (ctx->is_active) { |
c530ccd9 | 3478 | update_context_time(ctx); |
e5d1367f SE |
3479 | update_cgrp_time_from_event(event); |
3480 | } | |
0492d4c5 PZ |
3481 | if (group) |
3482 | update_group_times(event); | |
3483 | else | |
3484 | update_event_times(event); | |
e625cce1 | 3485 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3486 | } |
7d88962e SB |
3487 | |
3488 | return ret; | |
0793a61d TG |
3489 | } |
3490 | ||
a63eaf34 | 3491 | /* |
cdd6c482 | 3492 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3493 | */ |
eb184479 | 3494 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3495 | { |
e625cce1 | 3496 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3497 | mutex_init(&ctx->mutex); |
2fde4f94 | 3498 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3499 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3500 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3501 | INIT_LIST_HEAD(&ctx->event_list); |
3502 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3503 | } |
3504 | ||
3505 | static struct perf_event_context * | |
3506 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3507 | { | |
3508 | struct perf_event_context *ctx; | |
3509 | ||
3510 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3511 | if (!ctx) | |
3512 | return NULL; | |
3513 | ||
3514 | __perf_event_init_context(ctx); | |
3515 | if (task) { | |
3516 | ctx->task = task; | |
3517 | get_task_struct(task); | |
0793a61d | 3518 | } |
eb184479 PZ |
3519 | ctx->pmu = pmu; |
3520 | ||
3521 | return ctx; | |
a63eaf34 PM |
3522 | } |
3523 | ||
2ebd4ffb MH |
3524 | static struct task_struct * |
3525 | find_lively_task_by_vpid(pid_t vpid) | |
3526 | { | |
3527 | struct task_struct *task; | |
0793a61d TG |
3528 | |
3529 | rcu_read_lock(); | |
2ebd4ffb | 3530 | if (!vpid) |
0793a61d TG |
3531 | task = current; |
3532 | else | |
2ebd4ffb | 3533 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3534 | if (task) |
3535 | get_task_struct(task); | |
3536 | rcu_read_unlock(); | |
3537 | ||
3538 | if (!task) | |
3539 | return ERR_PTR(-ESRCH); | |
3540 | ||
2ebd4ffb | 3541 | return task; |
2ebd4ffb MH |
3542 | } |
3543 | ||
fe4b04fa PZ |
3544 | /* |
3545 | * Returns a matching context with refcount and pincount. | |
3546 | */ | |
108b02cf | 3547 | static struct perf_event_context * |
4af57ef2 YZ |
3548 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3549 | struct perf_event *event) | |
0793a61d | 3550 | { |
211de6eb | 3551 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3552 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3553 | void *task_ctx_data = NULL; |
25346b93 | 3554 | unsigned long flags; |
8dc85d54 | 3555 | int ctxn, err; |
4af57ef2 | 3556 | int cpu = event->cpu; |
0793a61d | 3557 | |
22a4ec72 | 3558 | if (!task) { |
cdd6c482 | 3559 | /* Must be root to operate on a CPU event: */ |
0764771d | 3560 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3561 | return ERR_PTR(-EACCES); |
3562 | ||
0793a61d | 3563 | /* |
cdd6c482 | 3564 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3565 | * offline CPU and activate it when the CPU comes up, but |
3566 | * that's for later. | |
3567 | */ | |
f6325e30 | 3568 | if (!cpu_online(cpu)) |
0793a61d TG |
3569 | return ERR_PTR(-ENODEV); |
3570 | ||
108b02cf | 3571 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3572 | ctx = &cpuctx->ctx; |
c93f7669 | 3573 | get_ctx(ctx); |
fe4b04fa | 3574 | ++ctx->pin_count; |
0793a61d | 3575 | |
0793a61d TG |
3576 | return ctx; |
3577 | } | |
3578 | ||
8dc85d54 PZ |
3579 | err = -EINVAL; |
3580 | ctxn = pmu->task_ctx_nr; | |
3581 | if (ctxn < 0) | |
3582 | goto errout; | |
3583 | ||
4af57ef2 YZ |
3584 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3585 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3586 | if (!task_ctx_data) { | |
3587 | err = -ENOMEM; | |
3588 | goto errout; | |
3589 | } | |
3590 | } | |
3591 | ||
9ed6060d | 3592 | retry: |
8dc85d54 | 3593 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3594 | if (ctx) { |
211de6eb | 3595 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3596 | ++ctx->pin_count; |
4af57ef2 YZ |
3597 | |
3598 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3599 | ctx->task_ctx_data = task_ctx_data; | |
3600 | task_ctx_data = NULL; | |
3601 | } | |
e625cce1 | 3602 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3603 | |
3604 | if (clone_ctx) | |
3605 | put_ctx(clone_ctx); | |
9137fb28 | 3606 | } else { |
eb184479 | 3607 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3608 | err = -ENOMEM; |
3609 | if (!ctx) | |
3610 | goto errout; | |
eb184479 | 3611 | |
4af57ef2 YZ |
3612 | if (task_ctx_data) { |
3613 | ctx->task_ctx_data = task_ctx_data; | |
3614 | task_ctx_data = NULL; | |
3615 | } | |
3616 | ||
dbe08d82 ON |
3617 | err = 0; |
3618 | mutex_lock(&task->perf_event_mutex); | |
3619 | /* | |
3620 | * If it has already passed perf_event_exit_task(). | |
3621 | * we must see PF_EXITING, it takes this mutex too. | |
3622 | */ | |
3623 | if (task->flags & PF_EXITING) | |
3624 | err = -ESRCH; | |
3625 | else if (task->perf_event_ctxp[ctxn]) | |
3626 | err = -EAGAIN; | |
fe4b04fa | 3627 | else { |
9137fb28 | 3628 | get_ctx(ctx); |
fe4b04fa | 3629 | ++ctx->pin_count; |
dbe08d82 | 3630 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3631 | } |
dbe08d82 ON |
3632 | mutex_unlock(&task->perf_event_mutex); |
3633 | ||
3634 | if (unlikely(err)) { | |
9137fb28 | 3635 | put_ctx(ctx); |
dbe08d82 ON |
3636 | |
3637 | if (err == -EAGAIN) | |
3638 | goto retry; | |
3639 | goto errout; | |
a63eaf34 PM |
3640 | } |
3641 | } | |
3642 | ||
4af57ef2 | 3643 | kfree(task_ctx_data); |
0793a61d | 3644 | return ctx; |
c93f7669 | 3645 | |
9ed6060d | 3646 | errout: |
4af57ef2 | 3647 | kfree(task_ctx_data); |
c93f7669 | 3648 | return ERR_PTR(err); |
0793a61d TG |
3649 | } |
3650 | ||
6fb2915d | 3651 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3652 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3653 | |
cdd6c482 | 3654 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3655 | { |
cdd6c482 | 3656 | struct perf_event *event; |
592903cd | 3657 | |
cdd6c482 IM |
3658 | event = container_of(head, struct perf_event, rcu_head); |
3659 | if (event->ns) | |
3660 | put_pid_ns(event->ns); | |
6fb2915d | 3661 | perf_event_free_filter(event); |
cdd6c482 | 3662 | kfree(event); |
592903cd PZ |
3663 | } |
3664 | ||
b69cf536 PZ |
3665 | static void ring_buffer_attach(struct perf_event *event, |
3666 | struct ring_buffer *rb); | |
925d519a | 3667 | |
4beb31f3 | 3668 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3669 | { |
4beb31f3 FW |
3670 | if (event->parent) |
3671 | return; | |
3672 | ||
4beb31f3 FW |
3673 | if (is_cgroup_event(event)) |
3674 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3675 | } | |
925d519a | 3676 | |
555e0c1e FW |
3677 | #ifdef CONFIG_NO_HZ_FULL |
3678 | static DEFINE_SPINLOCK(nr_freq_lock); | |
3679 | #endif | |
3680 | ||
3681 | static void unaccount_freq_event_nohz(void) | |
3682 | { | |
3683 | #ifdef CONFIG_NO_HZ_FULL | |
3684 | spin_lock(&nr_freq_lock); | |
3685 | if (atomic_dec_and_test(&nr_freq_events)) | |
3686 | tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS); | |
3687 | spin_unlock(&nr_freq_lock); | |
3688 | #endif | |
3689 | } | |
3690 | ||
3691 | static void unaccount_freq_event(void) | |
3692 | { | |
3693 | if (tick_nohz_full_enabled()) | |
3694 | unaccount_freq_event_nohz(); | |
3695 | else | |
3696 | atomic_dec(&nr_freq_events); | |
3697 | } | |
3698 | ||
4beb31f3 FW |
3699 | static void unaccount_event(struct perf_event *event) |
3700 | { | |
25432ae9 PZ |
3701 | bool dec = false; |
3702 | ||
4beb31f3 FW |
3703 | if (event->parent) |
3704 | return; | |
3705 | ||
3706 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3707 | dec = true; |
4beb31f3 FW |
3708 | if (event->attr.mmap || event->attr.mmap_data) |
3709 | atomic_dec(&nr_mmap_events); | |
3710 | if (event->attr.comm) | |
3711 | atomic_dec(&nr_comm_events); | |
3712 | if (event->attr.task) | |
3713 | atomic_dec(&nr_task_events); | |
948b26b6 | 3714 | if (event->attr.freq) |
555e0c1e | 3715 | unaccount_freq_event(); |
45ac1403 | 3716 | if (event->attr.context_switch) { |
25432ae9 | 3717 | dec = true; |
45ac1403 AH |
3718 | atomic_dec(&nr_switch_events); |
3719 | } | |
4beb31f3 | 3720 | if (is_cgroup_event(event)) |
25432ae9 | 3721 | dec = true; |
4beb31f3 | 3722 | if (has_branch_stack(event)) |
25432ae9 PZ |
3723 | dec = true; |
3724 | ||
9107c89e PZ |
3725 | if (dec) { |
3726 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
3727 | schedule_delayed_work(&perf_sched_work, HZ); | |
3728 | } | |
4beb31f3 FW |
3729 | |
3730 | unaccount_event_cpu(event, event->cpu); | |
3731 | } | |
925d519a | 3732 | |
9107c89e PZ |
3733 | static void perf_sched_delayed(struct work_struct *work) |
3734 | { | |
3735 | mutex_lock(&perf_sched_mutex); | |
3736 | if (atomic_dec_and_test(&perf_sched_count)) | |
3737 | static_branch_disable(&perf_sched_events); | |
3738 | mutex_unlock(&perf_sched_mutex); | |
3739 | } | |
3740 | ||
bed5b25a AS |
3741 | /* |
3742 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3743 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3744 | * at a time, so we disallow creating events that might conflict, namely: | |
3745 | * | |
3746 | * 1) cpu-wide events in the presence of per-task events, | |
3747 | * 2) per-task events in the presence of cpu-wide events, | |
3748 | * 3) two matching events on the same context. | |
3749 | * | |
3750 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3751 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3752 | */ |
3753 | static int exclusive_event_init(struct perf_event *event) | |
3754 | { | |
3755 | struct pmu *pmu = event->pmu; | |
3756 | ||
3757 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3758 | return 0; | |
3759 | ||
3760 | /* | |
3761 | * Prevent co-existence of per-task and cpu-wide events on the | |
3762 | * same exclusive pmu. | |
3763 | * | |
3764 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3765 | * events on this "exclusive" pmu, positive means there are | |
3766 | * per-task events. | |
3767 | * | |
3768 | * Since this is called in perf_event_alloc() path, event::ctx | |
3769 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3770 | * to mean "per-task event", because unlike other attach states it | |
3771 | * never gets cleared. | |
3772 | */ | |
3773 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3774 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3775 | return -EBUSY; | |
3776 | } else { | |
3777 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3778 | return -EBUSY; | |
3779 | } | |
3780 | ||
3781 | return 0; | |
3782 | } | |
3783 | ||
3784 | static void exclusive_event_destroy(struct perf_event *event) | |
3785 | { | |
3786 | struct pmu *pmu = event->pmu; | |
3787 | ||
3788 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3789 | return; | |
3790 | ||
3791 | /* see comment in exclusive_event_init() */ | |
3792 | if (event->attach_state & PERF_ATTACH_TASK) | |
3793 | atomic_dec(&pmu->exclusive_cnt); | |
3794 | else | |
3795 | atomic_inc(&pmu->exclusive_cnt); | |
3796 | } | |
3797 | ||
3798 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3799 | { | |
3800 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3801 | (e1->cpu == e2->cpu || | |
3802 | e1->cpu == -1 || | |
3803 | e2->cpu == -1)) | |
3804 | return true; | |
3805 | return false; | |
3806 | } | |
3807 | ||
3808 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3809 | static bool exclusive_event_installable(struct perf_event *event, | |
3810 | struct perf_event_context *ctx) | |
3811 | { | |
3812 | struct perf_event *iter_event; | |
3813 | struct pmu *pmu = event->pmu; | |
3814 | ||
3815 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3816 | return true; | |
3817 | ||
3818 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3819 | if (exclusive_event_match(iter_event, event)) | |
3820 | return false; | |
3821 | } | |
3822 | ||
3823 | return true; | |
3824 | } | |
3825 | ||
375637bc AS |
3826 | static void perf_addr_filters_splice(struct perf_event *event, |
3827 | struct list_head *head); | |
3828 | ||
683ede43 | 3829 | static void _free_event(struct perf_event *event) |
f1600952 | 3830 | { |
e360adbe | 3831 | irq_work_sync(&event->pending); |
925d519a | 3832 | |
4beb31f3 | 3833 | unaccount_event(event); |
9ee318a7 | 3834 | |
76369139 | 3835 | if (event->rb) { |
9bb5d40c PZ |
3836 | /* |
3837 | * Can happen when we close an event with re-directed output. | |
3838 | * | |
3839 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3840 | * over us; possibly making our ring_buffer_put() the last. | |
3841 | */ | |
3842 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3843 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3844 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3845 | } |
3846 | ||
e5d1367f SE |
3847 | if (is_cgroup_event(event)) |
3848 | perf_detach_cgroup(event); | |
3849 | ||
a0733e69 PZ |
3850 | if (!event->parent) { |
3851 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3852 | put_callchain_buffers(); | |
3853 | } | |
3854 | ||
3855 | perf_event_free_bpf_prog(event); | |
375637bc AS |
3856 | perf_addr_filters_splice(event, NULL); |
3857 | kfree(event->addr_filters_offs); | |
a0733e69 PZ |
3858 | |
3859 | if (event->destroy) | |
3860 | event->destroy(event); | |
3861 | ||
3862 | if (event->ctx) | |
3863 | put_ctx(event->ctx); | |
3864 | ||
3865 | if (event->pmu) { | |
3866 | exclusive_event_destroy(event); | |
3867 | module_put(event->pmu->module); | |
3868 | } | |
3869 | ||
3870 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3871 | } |
3872 | ||
683ede43 PZ |
3873 | /* |
3874 | * Used to free events which have a known refcount of 1, such as in error paths | |
3875 | * where the event isn't exposed yet and inherited events. | |
3876 | */ | |
3877 | static void free_event(struct perf_event *event) | |
0793a61d | 3878 | { |
683ede43 PZ |
3879 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3880 | "unexpected event refcount: %ld; ptr=%p\n", | |
3881 | atomic_long_read(&event->refcount), event)) { | |
3882 | /* leak to avoid use-after-free */ | |
3883 | return; | |
3884 | } | |
0793a61d | 3885 | |
683ede43 | 3886 | _free_event(event); |
0793a61d TG |
3887 | } |
3888 | ||
a66a3052 | 3889 | /* |
f8697762 | 3890 | * Remove user event from the owner task. |
a66a3052 | 3891 | */ |
f8697762 | 3892 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3893 | { |
8882135b | 3894 | struct task_struct *owner; |
fb0459d7 | 3895 | |
8882135b | 3896 | rcu_read_lock(); |
8882135b | 3897 | /* |
f47c02c0 PZ |
3898 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3899 | * observe !owner it means the list deletion is complete and we can | |
3900 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3901 | * owner->perf_event_mutex. |
3902 | */ | |
f47c02c0 | 3903 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3904 | if (owner) { |
3905 | /* | |
3906 | * Since delayed_put_task_struct() also drops the last | |
3907 | * task reference we can safely take a new reference | |
3908 | * while holding the rcu_read_lock(). | |
3909 | */ | |
3910 | get_task_struct(owner); | |
3911 | } | |
3912 | rcu_read_unlock(); | |
3913 | ||
3914 | if (owner) { | |
f63a8daa PZ |
3915 | /* |
3916 | * If we're here through perf_event_exit_task() we're already | |
3917 | * holding ctx->mutex which would be an inversion wrt. the | |
3918 | * normal lock order. | |
3919 | * | |
3920 | * However we can safely take this lock because its the child | |
3921 | * ctx->mutex. | |
3922 | */ | |
3923 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3924 | ||
8882135b PZ |
3925 | /* |
3926 | * We have to re-check the event->owner field, if it is cleared | |
3927 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3928 | * ensured they're done, and we can proceed with freeing the | |
3929 | * event. | |
3930 | */ | |
f47c02c0 | 3931 | if (event->owner) { |
8882135b | 3932 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3933 | smp_store_release(&event->owner, NULL); |
3934 | } | |
8882135b PZ |
3935 | mutex_unlock(&owner->perf_event_mutex); |
3936 | put_task_struct(owner); | |
3937 | } | |
f8697762 JO |
3938 | } |
3939 | ||
f8697762 JO |
3940 | static void put_event(struct perf_event *event) |
3941 | { | |
f8697762 JO |
3942 | if (!atomic_long_dec_and_test(&event->refcount)) |
3943 | return; | |
3944 | ||
c6e5b732 PZ |
3945 | _free_event(event); |
3946 | } | |
3947 | ||
3948 | /* | |
3949 | * Kill an event dead; while event:refcount will preserve the event | |
3950 | * object, it will not preserve its functionality. Once the last 'user' | |
3951 | * gives up the object, we'll destroy the thing. | |
3952 | */ | |
3953 | int perf_event_release_kernel(struct perf_event *event) | |
3954 | { | |
a4f4bb6d | 3955 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
3956 | struct perf_event *child, *tmp; |
3957 | ||
a4f4bb6d PZ |
3958 | /* |
3959 | * If we got here through err_file: fput(event_file); we will not have | |
3960 | * attached to a context yet. | |
3961 | */ | |
3962 | if (!ctx) { | |
3963 | WARN_ON_ONCE(event->attach_state & | |
3964 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
3965 | goto no_ctx; | |
3966 | } | |
3967 | ||
f8697762 JO |
3968 | if (!is_kernel_event(event)) |
3969 | perf_remove_from_owner(event); | |
8882135b | 3970 | |
5fa7c8ec | 3971 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3972 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 3973 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 3974 | |
a69b0ca4 | 3975 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 3976 | /* |
a69b0ca4 PZ |
3977 | * Mark this even as STATE_DEAD, there is no external reference to it |
3978 | * anymore. | |
683ede43 | 3979 | * |
a69b0ca4 PZ |
3980 | * Anybody acquiring event->child_mutex after the below loop _must_ |
3981 | * also see this, most importantly inherit_event() which will avoid | |
3982 | * placing more children on the list. | |
683ede43 | 3983 | * |
c6e5b732 PZ |
3984 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3985 | * child events. | |
683ede43 | 3986 | */ |
a69b0ca4 PZ |
3987 | event->state = PERF_EVENT_STATE_DEAD; |
3988 | raw_spin_unlock_irq(&ctx->lock); | |
3989 | ||
3990 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 3991 | |
c6e5b732 PZ |
3992 | again: |
3993 | mutex_lock(&event->child_mutex); | |
3994 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3995 | |
c6e5b732 PZ |
3996 | /* |
3997 | * Cannot change, child events are not migrated, see the | |
3998 | * comment with perf_event_ctx_lock_nested(). | |
3999 | */ | |
4000 | ctx = lockless_dereference(child->ctx); | |
4001 | /* | |
4002 | * Since child_mutex nests inside ctx::mutex, we must jump | |
4003 | * through hoops. We start by grabbing a reference on the ctx. | |
4004 | * | |
4005 | * Since the event cannot get freed while we hold the | |
4006 | * child_mutex, the context must also exist and have a !0 | |
4007 | * reference count. | |
4008 | */ | |
4009 | get_ctx(ctx); | |
4010 | ||
4011 | /* | |
4012 | * Now that we have a ctx ref, we can drop child_mutex, and | |
4013 | * acquire ctx::mutex without fear of it going away. Then we | |
4014 | * can re-acquire child_mutex. | |
4015 | */ | |
4016 | mutex_unlock(&event->child_mutex); | |
4017 | mutex_lock(&ctx->mutex); | |
4018 | mutex_lock(&event->child_mutex); | |
4019 | ||
4020 | /* | |
4021 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
4022 | * state, if child is still the first entry, it didn't get freed | |
4023 | * and we can continue doing so. | |
4024 | */ | |
4025 | tmp = list_first_entry_or_null(&event->child_list, | |
4026 | struct perf_event, child_list); | |
4027 | if (tmp == child) { | |
4028 | perf_remove_from_context(child, DETACH_GROUP); | |
4029 | list_del(&child->child_list); | |
4030 | free_event(child); | |
4031 | /* | |
4032 | * This matches the refcount bump in inherit_event(); | |
4033 | * this can't be the last reference. | |
4034 | */ | |
4035 | put_event(event); | |
4036 | } | |
4037 | ||
4038 | mutex_unlock(&event->child_mutex); | |
4039 | mutex_unlock(&ctx->mutex); | |
4040 | put_ctx(ctx); | |
4041 | goto again; | |
4042 | } | |
4043 | mutex_unlock(&event->child_mutex); | |
4044 | ||
a4f4bb6d PZ |
4045 | no_ctx: |
4046 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
4047 | return 0; |
4048 | } | |
4049 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
4050 | ||
8b10c5e2 PZ |
4051 | /* |
4052 | * Called when the last reference to the file is gone. | |
4053 | */ | |
a6fa941d AV |
4054 | static int perf_release(struct inode *inode, struct file *file) |
4055 | { | |
c6e5b732 | 4056 | perf_event_release_kernel(file->private_data); |
a6fa941d | 4057 | return 0; |
fb0459d7 | 4058 | } |
fb0459d7 | 4059 | |
59ed446f | 4060 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 4061 | { |
cdd6c482 | 4062 | struct perf_event *child; |
e53c0994 PZ |
4063 | u64 total = 0; |
4064 | ||
59ed446f PZ |
4065 | *enabled = 0; |
4066 | *running = 0; | |
4067 | ||
6f10581a | 4068 | mutex_lock(&event->child_mutex); |
01add3ea | 4069 | |
7d88962e | 4070 | (void)perf_event_read(event, false); |
01add3ea SB |
4071 | total += perf_event_count(event); |
4072 | ||
59ed446f PZ |
4073 | *enabled += event->total_time_enabled + |
4074 | atomic64_read(&event->child_total_time_enabled); | |
4075 | *running += event->total_time_running + | |
4076 | atomic64_read(&event->child_total_time_running); | |
4077 | ||
4078 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 4079 | (void)perf_event_read(child, false); |
01add3ea | 4080 | total += perf_event_count(child); |
59ed446f PZ |
4081 | *enabled += child->total_time_enabled; |
4082 | *running += child->total_time_running; | |
4083 | } | |
6f10581a | 4084 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
4085 | |
4086 | return total; | |
4087 | } | |
fb0459d7 | 4088 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 4089 | |
7d88962e | 4090 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 4091 | u64 read_format, u64 *values) |
3dab77fb | 4092 | { |
fa8c2693 PZ |
4093 | struct perf_event *sub; |
4094 | int n = 1; /* skip @nr */ | |
7d88962e | 4095 | int ret; |
f63a8daa | 4096 | |
7d88962e SB |
4097 | ret = perf_event_read(leader, true); |
4098 | if (ret) | |
4099 | return ret; | |
abf4868b | 4100 | |
fa8c2693 PZ |
4101 | /* |
4102 | * Since we co-schedule groups, {enabled,running} times of siblings | |
4103 | * will be identical to those of the leader, so we only publish one | |
4104 | * set. | |
4105 | */ | |
4106 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
4107 | values[n++] += leader->total_time_enabled + | |
4108 | atomic64_read(&leader->child_total_time_enabled); | |
4109 | } | |
3dab77fb | 4110 | |
fa8c2693 PZ |
4111 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
4112 | values[n++] += leader->total_time_running + | |
4113 | atomic64_read(&leader->child_total_time_running); | |
4114 | } | |
4115 | ||
4116 | /* | |
4117 | * Write {count,id} tuples for every sibling. | |
4118 | */ | |
4119 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
4120 | if (read_format & PERF_FORMAT_ID) |
4121 | values[n++] = primary_event_id(leader); | |
3dab77fb | 4122 | |
fa8c2693 PZ |
4123 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
4124 | values[n++] += perf_event_count(sub); | |
4125 | if (read_format & PERF_FORMAT_ID) | |
4126 | values[n++] = primary_event_id(sub); | |
4127 | } | |
7d88962e SB |
4128 | |
4129 | return 0; | |
fa8c2693 | 4130 | } |
3dab77fb | 4131 | |
fa8c2693 PZ |
4132 | static int perf_read_group(struct perf_event *event, |
4133 | u64 read_format, char __user *buf) | |
4134 | { | |
4135 | struct perf_event *leader = event->group_leader, *child; | |
4136 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 4137 | int ret; |
fa8c2693 | 4138 | u64 *values; |
3dab77fb | 4139 | |
fa8c2693 | 4140 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 4141 | |
fa8c2693 PZ |
4142 | values = kzalloc(event->read_size, GFP_KERNEL); |
4143 | if (!values) | |
4144 | return -ENOMEM; | |
3dab77fb | 4145 | |
fa8c2693 PZ |
4146 | values[0] = 1 + leader->nr_siblings; |
4147 | ||
4148 | /* | |
4149 | * By locking the child_mutex of the leader we effectively | |
4150 | * lock the child list of all siblings.. XXX explain how. | |
4151 | */ | |
4152 | mutex_lock(&leader->child_mutex); | |
abf4868b | 4153 | |
7d88962e SB |
4154 | ret = __perf_read_group_add(leader, read_format, values); |
4155 | if (ret) | |
4156 | goto unlock; | |
4157 | ||
4158 | list_for_each_entry(child, &leader->child_list, child_list) { | |
4159 | ret = __perf_read_group_add(child, read_format, values); | |
4160 | if (ret) | |
4161 | goto unlock; | |
4162 | } | |
abf4868b | 4163 | |
fa8c2693 | 4164 | mutex_unlock(&leader->child_mutex); |
abf4868b | 4165 | |
7d88962e | 4166 | ret = event->read_size; |
fa8c2693 PZ |
4167 | if (copy_to_user(buf, values, event->read_size)) |
4168 | ret = -EFAULT; | |
7d88962e | 4169 | goto out; |
fa8c2693 | 4170 | |
7d88962e SB |
4171 | unlock: |
4172 | mutex_unlock(&leader->child_mutex); | |
4173 | out: | |
fa8c2693 | 4174 | kfree(values); |
abf4868b | 4175 | return ret; |
3dab77fb PZ |
4176 | } |
4177 | ||
b15f495b | 4178 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4179 | u64 read_format, char __user *buf) |
4180 | { | |
59ed446f | 4181 | u64 enabled, running; |
3dab77fb PZ |
4182 | u64 values[4]; |
4183 | int n = 0; | |
4184 | ||
59ed446f PZ |
4185 | values[n++] = perf_event_read_value(event, &enabled, &running); |
4186 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4187 | values[n++] = enabled; | |
4188 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4189 | values[n++] = running; | |
3dab77fb | 4190 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4191 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4192 | |
4193 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4194 | return -EFAULT; | |
4195 | ||
4196 | return n * sizeof(u64); | |
4197 | } | |
4198 | ||
dc633982 JO |
4199 | static bool is_event_hup(struct perf_event *event) |
4200 | { | |
4201 | bool no_children; | |
4202 | ||
a69b0ca4 | 4203 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4204 | return false; |
4205 | ||
4206 | mutex_lock(&event->child_mutex); | |
4207 | no_children = list_empty(&event->child_list); | |
4208 | mutex_unlock(&event->child_mutex); | |
4209 | return no_children; | |
4210 | } | |
4211 | ||
0793a61d | 4212 | /* |
cdd6c482 | 4213 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4214 | */ |
4215 | static ssize_t | |
b15f495b | 4216 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4217 | { |
cdd6c482 | 4218 | u64 read_format = event->attr.read_format; |
3dab77fb | 4219 | int ret; |
0793a61d | 4220 | |
3b6f9e5c | 4221 | /* |
cdd6c482 | 4222 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4223 | * error state (i.e. because it was pinned but it couldn't be |
4224 | * scheduled on to the CPU at some point). | |
4225 | */ | |
cdd6c482 | 4226 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4227 | return 0; |
4228 | ||
c320c7b7 | 4229 | if (count < event->read_size) |
3dab77fb PZ |
4230 | return -ENOSPC; |
4231 | ||
cdd6c482 | 4232 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4233 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4234 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4235 | else |
b15f495b | 4236 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4237 | |
3dab77fb | 4238 | return ret; |
0793a61d TG |
4239 | } |
4240 | ||
0793a61d TG |
4241 | static ssize_t |
4242 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4243 | { | |
cdd6c482 | 4244 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4245 | struct perf_event_context *ctx; |
4246 | int ret; | |
0793a61d | 4247 | |
f63a8daa | 4248 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4249 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4250 | perf_event_ctx_unlock(event, ctx); |
4251 | ||
4252 | return ret; | |
0793a61d TG |
4253 | } |
4254 | ||
4255 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4256 | { | |
cdd6c482 | 4257 | struct perf_event *event = file->private_data; |
76369139 | 4258 | struct ring_buffer *rb; |
61b67684 | 4259 | unsigned int events = POLLHUP; |
c7138f37 | 4260 | |
e708d7ad | 4261 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4262 | |
dc633982 | 4263 | if (is_event_hup(event)) |
179033b3 | 4264 | return events; |
c7138f37 | 4265 | |
10c6db11 | 4266 | /* |
9bb5d40c PZ |
4267 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4268 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4269 | */ |
4270 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4271 | rb = event->rb; |
4272 | if (rb) | |
76369139 | 4273 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4274 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4275 | return events; |
4276 | } | |
4277 | ||
f63a8daa | 4278 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4279 | { |
7d88962e | 4280 | (void)perf_event_read(event, false); |
e7850595 | 4281 | local64_set(&event->count, 0); |
cdd6c482 | 4282 | perf_event_update_userpage(event); |
3df5edad PZ |
4283 | } |
4284 | ||
c93f7669 | 4285 | /* |
cdd6c482 IM |
4286 | * Holding the top-level event's child_mutex means that any |
4287 | * descendant process that has inherited this event will block | |
8ba289b8 | 4288 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4289 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4290 | */ |
cdd6c482 IM |
4291 | static void perf_event_for_each_child(struct perf_event *event, |
4292 | void (*func)(struct perf_event *)) | |
3df5edad | 4293 | { |
cdd6c482 | 4294 | struct perf_event *child; |
3df5edad | 4295 | |
cdd6c482 | 4296 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4297 | |
cdd6c482 IM |
4298 | mutex_lock(&event->child_mutex); |
4299 | func(event); | |
4300 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4301 | func(child); |
cdd6c482 | 4302 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4303 | } |
4304 | ||
cdd6c482 IM |
4305 | static void perf_event_for_each(struct perf_event *event, |
4306 | void (*func)(struct perf_event *)) | |
3df5edad | 4307 | { |
cdd6c482 IM |
4308 | struct perf_event_context *ctx = event->ctx; |
4309 | struct perf_event *sibling; | |
3df5edad | 4310 | |
f63a8daa PZ |
4311 | lockdep_assert_held(&ctx->mutex); |
4312 | ||
cdd6c482 | 4313 | event = event->group_leader; |
75f937f2 | 4314 | |
cdd6c482 | 4315 | perf_event_for_each_child(event, func); |
cdd6c482 | 4316 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4317 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4318 | } |
4319 | ||
fae3fde6 PZ |
4320 | static void __perf_event_period(struct perf_event *event, |
4321 | struct perf_cpu_context *cpuctx, | |
4322 | struct perf_event_context *ctx, | |
4323 | void *info) | |
c7999c6f | 4324 | { |
fae3fde6 | 4325 | u64 value = *((u64 *)info); |
c7999c6f | 4326 | bool active; |
08247e31 | 4327 | |
cdd6c482 | 4328 | if (event->attr.freq) { |
cdd6c482 | 4329 | event->attr.sample_freq = value; |
08247e31 | 4330 | } else { |
cdd6c482 IM |
4331 | event->attr.sample_period = value; |
4332 | event->hw.sample_period = value; | |
08247e31 | 4333 | } |
bad7192b PZ |
4334 | |
4335 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4336 | if (active) { | |
4337 | perf_pmu_disable(ctx->pmu); | |
1e02cd40 PZ |
4338 | /* |
4339 | * We could be throttled; unthrottle now to avoid the tick | |
4340 | * trying to unthrottle while we already re-started the event. | |
4341 | */ | |
4342 | if (event->hw.interrupts == MAX_INTERRUPTS) { | |
4343 | event->hw.interrupts = 0; | |
4344 | perf_log_throttle(event, 1); | |
4345 | } | |
bad7192b PZ |
4346 | event->pmu->stop(event, PERF_EF_UPDATE); |
4347 | } | |
4348 | ||
4349 | local64_set(&event->hw.period_left, 0); | |
4350 | ||
4351 | if (active) { | |
4352 | event->pmu->start(event, PERF_EF_RELOAD); | |
4353 | perf_pmu_enable(ctx->pmu); | |
4354 | } | |
c7999c6f PZ |
4355 | } |
4356 | ||
4357 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4358 | { | |
c7999c6f PZ |
4359 | u64 value; |
4360 | ||
4361 | if (!is_sampling_event(event)) | |
4362 | return -EINVAL; | |
4363 | ||
4364 | if (copy_from_user(&value, arg, sizeof(value))) | |
4365 | return -EFAULT; | |
4366 | ||
4367 | if (!value) | |
4368 | return -EINVAL; | |
4369 | ||
4370 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4371 | return -EINVAL; | |
4372 | ||
fae3fde6 | 4373 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4374 | |
c7999c6f | 4375 | return 0; |
08247e31 PZ |
4376 | } |
4377 | ||
ac9721f3 PZ |
4378 | static const struct file_operations perf_fops; |
4379 | ||
2903ff01 | 4380 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4381 | { |
2903ff01 AV |
4382 | struct fd f = fdget(fd); |
4383 | if (!f.file) | |
4384 | return -EBADF; | |
ac9721f3 | 4385 | |
2903ff01 AV |
4386 | if (f.file->f_op != &perf_fops) { |
4387 | fdput(f); | |
4388 | return -EBADF; | |
ac9721f3 | 4389 | } |
2903ff01 AV |
4390 | *p = f; |
4391 | return 0; | |
ac9721f3 PZ |
4392 | } |
4393 | ||
4394 | static int perf_event_set_output(struct perf_event *event, | |
4395 | struct perf_event *output_event); | |
6fb2915d | 4396 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4397 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4398 | |
f63a8daa | 4399 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4400 | { |
cdd6c482 | 4401 | void (*func)(struct perf_event *); |
3df5edad | 4402 | u32 flags = arg; |
d859e29f PM |
4403 | |
4404 | switch (cmd) { | |
cdd6c482 | 4405 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4406 | func = _perf_event_enable; |
d859e29f | 4407 | break; |
cdd6c482 | 4408 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4409 | func = _perf_event_disable; |
79f14641 | 4410 | break; |
cdd6c482 | 4411 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4412 | func = _perf_event_reset; |
6de6a7b9 | 4413 | break; |
3df5edad | 4414 | |
cdd6c482 | 4415 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4416 | return _perf_event_refresh(event, arg); |
08247e31 | 4417 | |
cdd6c482 IM |
4418 | case PERF_EVENT_IOC_PERIOD: |
4419 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4420 | |
cf4957f1 JO |
4421 | case PERF_EVENT_IOC_ID: |
4422 | { | |
4423 | u64 id = primary_event_id(event); | |
4424 | ||
4425 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4426 | return -EFAULT; | |
4427 | return 0; | |
4428 | } | |
4429 | ||
cdd6c482 | 4430 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4431 | { |
ac9721f3 | 4432 | int ret; |
ac9721f3 | 4433 | if (arg != -1) { |
2903ff01 AV |
4434 | struct perf_event *output_event; |
4435 | struct fd output; | |
4436 | ret = perf_fget_light(arg, &output); | |
4437 | if (ret) | |
4438 | return ret; | |
4439 | output_event = output.file->private_data; | |
4440 | ret = perf_event_set_output(event, output_event); | |
4441 | fdput(output); | |
4442 | } else { | |
4443 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4444 | } |
ac9721f3 PZ |
4445 | return ret; |
4446 | } | |
a4be7c27 | 4447 | |
6fb2915d LZ |
4448 | case PERF_EVENT_IOC_SET_FILTER: |
4449 | return perf_event_set_filter(event, (void __user *)arg); | |
4450 | ||
2541517c AS |
4451 | case PERF_EVENT_IOC_SET_BPF: |
4452 | return perf_event_set_bpf_prog(event, arg); | |
4453 | ||
86e7972f WN |
4454 | case PERF_EVENT_IOC_PAUSE_OUTPUT: { |
4455 | struct ring_buffer *rb; | |
4456 | ||
4457 | rcu_read_lock(); | |
4458 | rb = rcu_dereference(event->rb); | |
4459 | if (!rb || !rb->nr_pages) { | |
4460 | rcu_read_unlock(); | |
4461 | return -EINVAL; | |
4462 | } | |
4463 | rb_toggle_paused(rb, !!arg); | |
4464 | rcu_read_unlock(); | |
4465 | return 0; | |
4466 | } | |
d859e29f | 4467 | default: |
3df5edad | 4468 | return -ENOTTY; |
d859e29f | 4469 | } |
3df5edad PZ |
4470 | |
4471 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4472 | perf_event_for_each(event, func); |
3df5edad | 4473 | else |
cdd6c482 | 4474 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4475 | |
4476 | return 0; | |
d859e29f PM |
4477 | } |
4478 | ||
f63a8daa PZ |
4479 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4480 | { | |
4481 | struct perf_event *event = file->private_data; | |
4482 | struct perf_event_context *ctx; | |
4483 | long ret; | |
4484 | ||
4485 | ctx = perf_event_ctx_lock(event); | |
4486 | ret = _perf_ioctl(event, cmd, arg); | |
4487 | perf_event_ctx_unlock(event, ctx); | |
4488 | ||
4489 | return ret; | |
4490 | } | |
4491 | ||
b3f20785 PM |
4492 | #ifdef CONFIG_COMPAT |
4493 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4494 | unsigned long arg) | |
4495 | { | |
4496 | switch (_IOC_NR(cmd)) { | |
4497 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4498 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4499 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4500 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4501 | cmd &= ~IOCSIZE_MASK; | |
4502 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4503 | } | |
4504 | break; | |
4505 | } | |
4506 | return perf_ioctl(file, cmd, arg); | |
4507 | } | |
4508 | #else | |
4509 | # define perf_compat_ioctl NULL | |
4510 | #endif | |
4511 | ||
cdd6c482 | 4512 | int perf_event_task_enable(void) |
771d7cde | 4513 | { |
f63a8daa | 4514 | struct perf_event_context *ctx; |
cdd6c482 | 4515 | struct perf_event *event; |
771d7cde | 4516 | |
cdd6c482 | 4517 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4518 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4519 | ctx = perf_event_ctx_lock(event); | |
4520 | perf_event_for_each_child(event, _perf_event_enable); | |
4521 | perf_event_ctx_unlock(event, ctx); | |
4522 | } | |
cdd6c482 | 4523 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4524 | |
4525 | return 0; | |
4526 | } | |
4527 | ||
cdd6c482 | 4528 | int perf_event_task_disable(void) |
771d7cde | 4529 | { |
f63a8daa | 4530 | struct perf_event_context *ctx; |
cdd6c482 | 4531 | struct perf_event *event; |
771d7cde | 4532 | |
cdd6c482 | 4533 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4534 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4535 | ctx = perf_event_ctx_lock(event); | |
4536 | perf_event_for_each_child(event, _perf_event_disable); | |
4537 | perf_event_ctx_unlock(event, ctx); | |
4538 | } | |
cdd6c482 | 4539 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4540 | |
4541 | return 0; | |
4542 | } | |
4543 | ||
cdd6c482 | 4544 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4545 | { |
a4eaf7f1 PZ |
4546 | if (event->hw.state & PERF_HES_STOPPED) |
4547 | return 0; | |
4548 | ||
cdd6c482 | 4549 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4550 | return 0; |
4551 | ||
35edc2a5 | 4552 | return event->pmu->event_idx(event); |
194002b2 PZ |
4553 | } |
4554 | ||
c4794295 | 4555 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4556 | u64 *now, |
7f310a5d EM |
4557 | u64 *enabled, |
4558 | u64 *running) | |
c4794295 | 4559 | { |
e3f3541c | 4560 | u64 ctx_time; |
c4794295 | 4561 | |
e3f3541c PZ |
4562 | *now = perf_clock(); |
4563 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4564 | *enabled = ctx_time - event->tstamp_enabled; |
4565 | *running = ctx_time - event->tstamp_running; | |
4566 | } | |
4567 | ||
fa731587 PZ |
4568 | static void perf_event_init_userpage(struct perf_event *event) |
4569 | { | |
4570 | struct perf_event_mmap_page *userpg; | |
4571 | struct ring_buffer *rb; | |
4572 | ||
4573 | rcu_read_lock(); | |
4574 | rb = rcu_dereference(event->rb); | |
4575 | if (!rb) | |
4576 | goto unlock; | |
4577 | ||
4578 | userpg = rb->user_page; | |
4579 | ||
4580 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4581 | userpg->cap_bit0_is_deprecated = 1; | |
4582 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4583 | userpg->data_offset = PAGE_SIZE; |
4584 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4585 | |
4586 | unlock: | |
4587 | rcu_read_unlock(); | |
4588 | } | |
4589 | ||
c1317ec2 AL |
4590 | void __weak arch_perf_update_userpage( |
4591 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4592 | { |
4593 | } | |
4594 | ||
38ff667b PZ |
4595 | /* |
4596 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4597 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4598 | * code calls this from NMI context. | |
4599 | */ | |
cdd6c482 | 4600 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4601 | { |
cdd6c482 | 4602 | struct perf_event_mmap_page *userpg; |
76369139 | 4603 | struct ring_buffer *rb; |
e3f3541c | 4604 | u64 enabled, running, now; |
38ff667b PZ |
4605 | |
4606 | rcu_read_lock(); | |
5ec4c599 PZ |
4607 | rb = rcu_dereference(event->rb); |
4608 | if (!rb) | |
4609 | goto unlock; | |
4610 | ||
0d641208 EM |
4611 | /* |
4612 | * compute total_time_enabled, total_time_running | |
4613 | * based on snapshot values taken when the event | |
4614 | * was last scheduled in. | |
4615 | * | |
4616 | * we cannot simply called update_context_time() | |
4617 | * because of locking issue as we can be called in | |
4618 | * NMI context | |
4619 | */ | |
e3f3541c | 4620 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4621 | |
76369139 | 4622 | userpg = rb->user_page; |
7b732a75 PZ |
4623 | /* |
4624 | * Disable preemption so as to not let the corresponding user-space | |
4625 | * spin too long if we get preempted. | |
4626 | */ | |
4627 | preempt_disable(); | |
37d81828 | 4628 | ++userpg->lock; |
92f22a38 | 4629 | barrier(); |
cdd6c482 | 4630 | userpg->index = perf_event_index(event); |
b5e58793 | 4631 | userpg->offset = perf_event_count(event); |
365a4038 | 4632 | if (userpg->index) |
e7850595 | 4633 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4634 | |
0d641208 | 4635 | userpg->time_enabled = enabled + |
cdd6c482 | 4636 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4637 | |
0d641208 | 4638 | userpg->time_running = running + |
cdd6c482 | 4639 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4640 | |
c1317ec2 | 4641 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4642 | |
92f22a38 | 4643 | barrier(); |
37d81828 | 4644 | ++userpg->lock; |
7b732a75 | 4645 | preempt_enable(); |
38ff667b | 4646 | unlock: |
7b732a75 | 4647 | rcu_read_unlock(); |
37d81828 PM |
4648 | } |
4649 | ||
906010b2 PZ |
4650 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4651 | { | |
4652 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4653 | struct ring_buffer *rb; |
906010b2 PZ |
4654 | int ret = VM_FAULT_SIGBUS; |
4655 | ||
4656 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4657 | if (vmf->pgoff == 0) | |
4658 | ret = 0; | |
4659 | return ret; | |
4660 | } | |
4661 | ||
4662 | rcu_read_lock(); | |
76369139 FW |
4663 | rb = rcu_dereference(event->rb); |
4664 | if (!rb) | |
906010b2 PZ |
4665 | goto unlock; |
4666 | ||
4667 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4668 | goto unlock; | |
4669 | ||
76369139 | 4670 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4671 | if (!vmf->page) |
4672 | goto unlock; | |
4673 | ||
4674 | get_page(vmf->page); | |
4675 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4676 | vmf->page->index = vmf->pgoff; | |
4677 | ||
4678 | ret = 0; | |
4679 | unlock: | |
4680 | rcu_read_unlock(); | |
4681 | ||
4682 | return ret; | |
4683 | } | |
4684 | ||
10c6db11 PZ |
4685 | static void ring_buffer_attach(struct perf_event *event, |
4686 | struct ring_buffer *rb) | |
4687 | { | |
b69cf536 | 4688 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4689 | unsigned long flags; |
4690 | ||
b69cf536 PZ |
4691 | if (event->rb) { |
4692 | /* | |
4693 | * Should be impossible, we set this when removing | |
4694 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4695 | */ | |
4696 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4697 | |
b69cf536 | 4698 | old_rb = event->rb; |
b69cf536 PZ |
4699 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4700 | list_del_rcu(&event->rb_entry); | |
4701 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4702 | |
2f993cf0 ON |
4703 | event->rcu_batches = get_state_synchronize_rcu(); |
4704 | event->rcu_pending = 1; | |
b69cf536 | 4705 | } |
10c6db11 | 4706 | |
b69cf536 | 4707 | if (rb) { |
2f993cf0 ON |
4708 | if (event->rcu_pending) { |
4709 | cond_synchronize_rcu(event->rcu_batches); | |
4710 | event->rcu_pending = 0; | |
4711 | } | |
4712 | ||
b69cf536 PZ |
4713 | spin_lock_irqsave(&rb->event_lock, flags); |
4714 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4715 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4716 | } | |
4717 | ||
4718 | rcu_assign_pointer(event->rb, rb); | |
4719 | ||
4720 | if (old_rb) { | |
4721 | ring_buffer_put(old_rb); | |
4722 | /* | |
4723 | * Since we detached before setting the new rb, so that we | |
4724 | * could attach the new rb, we could have missed a wakeup. | |
4725 | * Provide it now. | |
4726 | */ | |
4727 | wake_up_all(&event->waitq); | |
4728 | } | |
10c6db11 PZ |
4729 | } |
4730 | ||
4731 | static void ring_buffer_wakeup(struct perf_event *event) | |
4732 | { | |
4733 | struct ring_buffer *rb; | |
4734 | ||
4735 | rcu_read_lock(); | |
4736 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4737 | if (rb) { |
4738 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4739 | wake_up_all(&event->waitq); | |
4740 | } | |
10c6db11 PZ |
4741 | rcu_read_unlock(); |
4742 | } | |
4743 | ||
fdc26706 | 4744 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4745 | { |
76369139 | 4746 | struct ring_buffer *rb; |
7b732a75 | 4747 | |
ac9721f3 | 4748 | rcu_read_lock(); |
76369139 FW |
4749 | rb = rcu_dereference(event->rb); |
4750 | if (rb) { | |
4751 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4752 | rb = NULL; | |
ac9721f3 PZ |
4753 | } |
4754 | rcu_read_unlock(); | |
4755 | ||
76369139 | 4756 | return rb; |
ac9721f3 PZ |
4757 | } |
4758 | ||
fdc26706 | 4759 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4760 | { |
76369139 | 4761 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4762 | return; |
7b732a75 | 4763 | |
9bb5d40c | 4764 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4765 | |
76369139 | 4766 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4767 | } |
4768 | ||
4769 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4770 | { | |
cdd6c482 | 4771 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4772 | |
cdd6c482 | 4773 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4774 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4775 | |
45bfb2e5 PZ |
4776 | if (vma->vm_pgoff) |
4777 | atomic_inc(&event->rb->aux_mmap_count); | |
4778 | ||
1e0fb9ec AL |
4779 | if (event->pmu->event_mapped) |
4780 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4781 | } |
4782 | ||
95ff4ca2 AS |
4783 | static void perf_pmu_output_stop(struct perf_event *event); |
4784 | ||
9bb5d40c PZ |
4785 | /* |
4786 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4787 | * event, or through other events by use of perf_event_set_output(). | |
4788 | * | |
4789 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4790 | * the buffer here, where we still have a VM context. This means we need | |
4791 | * to detach all events redirecting to us. | |
4792 | */ | |
7b732a75 PZ |
4793 | static void perf_mmap_close(struct vm_area_struct *vma) |
4794 | { | |
cdd6c482 | 4795 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4796 | |
b69cf536 | 4797 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4798 | struct user_struct *mmap_user = rb->mmap_user; |
4799 | int mmap_locked = rb->mmap_locked; | |
4800 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4801 | |
1e0fb9ec AL |
4802 | if (event->pmu->event_unmapped) |
4803 | event->pmu->event_unmapped(event); | |
4804 | ||
45bfb2e5 PZ |
4805 | /* |
4806 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4807 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4808 | * serialize with perf_mmap here. | |
4809 | */ | |
4810 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4811 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
95ff4ca2 AS |
4812 | /* |
4813 | * Stop all AUX events that are writing to this buffer, | |
4814 | * so that we can free its AUX pages and corresponding PMU | |
4815 | * data. Note that after rb::aux_mmap_count dropped to zero, | |
4816 | * they won't start any more (see perf_aux_output_begin()). | |
4817 | */ | |
4818 | perf_pmu_output_stop(event); | |
4819 | ||
4820 | /* now it's safe to free the pages */ | |
45bfb2e5 PZ |
4821 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); |
4822 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4823 | ||
95ff4ca2 | 4824 | /* this has to be the last one */ |
45bfb2e5 | 4825 | rb_free_aux(rb); |
95ff4ca2 AS |
4826 | WARN_ON_ONCE(atomic_read(&rb->aux_refcount)); |
4827 | ||
45bfb2e5 PZ |
4828 | mutex_unlock(&event->mmap_mutex); |
4829 | } | |
4830 | ||
9bb5d40c PZ |
4831 | atomic_dec(&rb->mmap_count); |
4832 | ||
4833 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4834 | goto out_put; |
9bb5d40c | 4835 | |
b69cf536 | 4836 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4837 | mutex_unlock(&event->mmap_mutex); |
4838 | ||
4839 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4840 | if (atomic_read(&rb->mmap_count)) |
4841 | goto out_put; | |
ac9721f3 | 4842 | |
9bb5d40c PZ |
4843 | /* |
4844 | * No other mmap()s, detach from all other events that might redirect | |
4845 | * into the now unreachable buffer. Somewhat complicated by the | |
4846 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4847 | */ | |
4848 | again: | |
4849 | rcu_read_lock(); | |
4850 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4851 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4852 | /* | |
4853 | * This event is en-route to free_event() which will | |
4854 | * detach it and remove it from the list. | |
4855 | */ | |
4856 | continue; | |
4857 | } | |
4858 | rcu_read_unlock(); | |
789f90fc | 4859 | |
9bb5d40c PZ |
4860 | mutex_lock(&event->mmap_mutex); |
4861 | /* | |
4862 | * Check we didn't race with perf_event_set_output() which can | |
4863 | * swizzle the rb from under us while we were waiting to | |
4864 | * acquire mmap_mutex. | |
4865 | * | |
4866 | * If we find a different rb; ignore this event, a next | |
4867 | * iteration will no longer find it on the list. We have to | |
4868 | * still restart the iteration to make sure we're not now | |
4869 | * iterating the wrong list. | |
4870 | */ | |
b69cf536 PZ |
4871 | if (event->rb == rb) |
4872 | ring_buffer_attach(event, NULL); | |
4873 | ||
cdd6c482 | 4874 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4875 | put_event(event); |
ac9721f3 | 4876 | |
9bb5d40c PZ |
4877 | /* |
4878 | * Restart the iteration; either we're on the wrong list or | |
4879 | * destroyed its integrity by doing a deletion. | |
4880 | */ | |
4881 | goto again; | |
7b732a75 | 4882 | } |
9bb5d40c PZ |
4883 | rcu_read_unlock(); |
4884 | ||
4885 | /* | |
4886 | * It could be there's still a few 0-ref events on the list; they'll | |
4887 | * get cleaned up by free_event() -- they'll also still have their | |
4888 | * ref on the rb and will free it whenever they are done with it. | |
4889 | * | |
4890 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4891 | * undo the VM accounting. | |
4892 | */ | |
4893 | ||
4894 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4895 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4896 | free_uid(mmap_user); | |
4897 | ||
b69cf536 | 4898 | out_put: |
9bb5d40c | 4899 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4900 | } |
4901 | ||
f0f37e2f | 4902 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4903 | .open = perf_mmap_open, |
45bfb2e5 | 4904 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4905 | .fault = perf_mmap_fault, |
4906 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4907 | }; |
4908 | ||
4909 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4910 | { | |
cdd6c482 | 4911 | struct perf_event *event = file->private_data; |
22a4f650 | 4912 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4913 | struct user_struct *user = current_user(); |
22a4f650 | 4914 | unsigned long locked, lock_limit; |
45bfb2e5 | 4915 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4916 | unsigned long vma_size; |
4917 | unsigned long nr_pages; | |
45bfb2e5 | 4918 | long user_extra = 0, extra = 0; |
d57e34fd | 4919 | int ret = 0, flags = 0; |
37d81828 | 4920 | |
c7920614 PZ |
4921 | /* |
4922 | * Don't allow mmap() of inherited per-task counters. This would | |
4923 | * create a performance issue due to all children writing to the | |
76369139 | 4924 | * same rb. |
c7920614 PZ |
4925 | */ |
4926 | if (event->cpu == -1 && event->attr.inherit) | |
4927 | return -EINVAL; | |
4928 | ||
43a21ea8 | 4929 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4930 | return -EINVAL; |
7b732a75 PZ |
4931 | |
4932 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4933 | |
4934 | if (vma->vm_pgoff == 0) { | |
4935 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4936 | } else { | |
4937 | /* | |
4938 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4939 | * mapped, all subsequent mappings should have the same size | |
4940 | * and offset. Must be above the normal perf buffer. | |
4941 | */ | |
4942 | u64 aux_offset, aux_size; | |
4943 | ||
4944 | if (!event->rb) | |
4945 | return -EINVAL; | |
4946 | ||
4947 | nr_pages = vma_size / PAGE_SIZE; | |
4948 | ||
4949 | mutex_lock(&event->mmap_mutex); | |
4950 | ret = -EINVAL; | |
4951 | ||
4952 | rb = event->rb; | |
4953 | if (!rb) | |
4954 | goto aux_unlock; | |
4955 | ||
4956 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4957 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4958 | ||
4959 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4960 | goto aux_unlock; | |
4961 | ||
4962 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4963 | goto aux_unlock; | |
4964 | ||
4965 | /* already mapped with a different offset */ | |
4966 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4967 | goto aux_unlock; | |
4968 | ||
4969 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4970 | goto aux_unlock; | |
4971 | ||
4972 | /* already mapped with a different size */ | |
4973 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4974 | goto aux_unlock; | |
4975 | ||
4976 | if (!is_power_of_2(nr_pages)) | |
4977 | goto aux_unlock; | |
4978 | ||
4979 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4980 | goto aux_unlock; | |
4981 | ||
4982 | if (rb_has_aux(rb)) { | |
4983 | atomic_inc(&rb->aux_mmap_count); | |
4984 | ret = 0; | |
4985 | goto unlock; | |
4986 | } | |
4987 | ||
4988 | atomic_set(&rb->aux_mmap_count, 1); | |
4989 | user_extra = nr_pages; | |
4990 | ||
4991 | goto accounting; | |
4992 | } | |
7b732a75 | 4993 | |
7730d865 | 4994 | /* |
76369139 | 4995 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4996 | * can do bitmasks instead of modulo. |
4997 | */ | |
2ed11312 | 4998 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4999 | return -EINVAL; |
5000 | ||
7b732a75 | 5001 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
5002 | return -EINVAL; |
5003 | ||
cdd6c482 | 5004 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 5005 | again: |
cdd6c482 | 5006 | mutex_lock(&event->mmap_mutex); |
76369139 | 5007 | if (event->rb) { |
9bb5d40c | 5008 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 5009 | ret = -EINVAL; |
9bb5d40c PZ |
5010 | goto unlock; |
5011 | } | |
5012 | ||
5013 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
5014 | /* | |
5015 | * Raced against perf_mmap_close() through | |
5016 | * perf_event_set_output(). Try again, hope for better | |
5017 | * luck. | |
5018 | */ | |
5019 | mutex_unlock(&event->mmap_mutex); | |
5020 | goto again; | |
5021 | } | |
5022 | ||
ebb3c4c4 PZ |
5023 | goto unlock; |
5024 | } | |
5025 | ||
789f90fc | 5026 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
5027 | |
5028 | accounting: | |
cdd6c482 | 5029 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
5030 | |
5031 | /* | |
5032 | * Increase the limit linearly with more CPUs: | |
5033 | */ | |
5034 | user_lock_limit *= num_online_cpus(); | |
5035 | ||
789f90fc | 5036 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 5037 | |
789f90fc PZ |
5038 | if (user_locked > user_lock_limit) |
5039 | extra = user_locked - user_lock_limit; | |
7b732a75 | 5040 | |
78d7d407 | 5041 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 5042 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 5043 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 5044 | |
459ec28a IM |
5045 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
5046 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
5047 | ret = -EPERM; |
5048 | goto unlock; | |
5049 | } | |
7b732a75 | 5050 | |
45bfb2e5 | 5051 | WARN_ON(!rb && event->rb); |
906010b2 | 5052 | |
d57e34fd | 5053 | if (vma->vm_flags & VM_WRITE) |
76369139 | 5054 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 5055 | |
76369139 | 5056 | if (!rb) { |
45bfb2e5 PZ |
5057 | rb = rb_alloc(nr_pages, |
5058 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
5059 | event->cpu, flags); | |
26cb63ad | 5060 | |
45bfb2e5 PZ |
5061 | if (!rb) { |
5062 | ret = -ENOMEM; | |
5063 | goto unlock; | |
5064 | } | |
43a21ea8 | 5065 | |
45bfb2e5 PZ |
5066 | atomic_set(&rb->mmap_count, 1); |
5067 | rb->mmap_user = get_current_user(); | |
5068 | rb->mmap_locked = extra; | |
26cb63ad | 5069 | |
45bfb2e5 | 5070 | ring_buffer_attach(event, rb); |
ac9721f3 | 5071 | |
45bfb2e5 PZ |
5072 | perf_event_init_userpage(event); |
5073 | perf_event_update_userpage(event); | |
5074 | } else { | |
1a594131 AS |
5075 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
5076 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
5077 | if (!ret) |
5078 | rb->aux_mmap_locked = extra; | |
5079 | } | |
9a0f05cb | 5080 | |
ebb3c4c4 | 5081 | unlock: |
45bfb2e5 PZ |
5082 | if (!ret) { |
5083 | atomic_long_add(user_extra, &user->locked_vm); | |
5084 | vma->vm_mm->pinned_vm += extra; | |
5085 | ||
ac9721f3 | 5086 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
5087 | } else if (rb) { |
5088 | atomic_dec(&rb->mmap_count); | |
5089 | } | |
5090 | aux_unlock: | |
cdd6c482 | 5091 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 5092 | |
9bb5d40c PZ |
5093 | /* |
5094 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
5095 | * vma. | |
5096 | */ | |
26cb63ad | 5097 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 5098 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 5099 | |
1e0fb9ec AL |
5100 | if (event->pmu->event_mapped) |
5101 | event->pmu->event_mapped(event); | |
5102 | ||
7b732a75 | 5103 | return ret; |
37d81828 PM |
5104 | } |
5105 | ||
3c446b3d PZ |
5106 | static int perf_fasync(int fd, struct file *filp, int on) |
5107 | { | |
496ad9aa | 5108 | struct inode *inode = file_inode(filp); |
cdd6c482 | 5109 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
5110 | int retval; |
5111 | ||
5955102c | 5112 | inode_lock(inode); |
cdd6c482 | 5113 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 5114 | inode_unlock(inode); |
3c446b3d PZ |
5115 | |
5116 | if (retval < 0) | |
5117 | return retval; | |
5118 | ||
5119 | return 0; | |
5120 | } | |
5121 | ||
0793a61d | 5122 | static const struct file_operations perf_fops = { |
3326c1ce | 5123 | .llseek = no_llseek, |
0793a61d TG |
5124 | .release = perf_release, |
5125 | .read = perf_read, | |
5126 | .poll = perf_poll, | |
d859e29f | 5127 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 5128 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 5129 | .mmap = perf_mmap, |
3c446b3d | 5130 | .fasync = perf_fasync, |
0793a61d TG |
5131 | }; |
5132 | ||
925d519a | 5133 | /* |
cdd6c482 | 5134 | * Perf event wakeup |
925d519a PZ |
5135 | * |
5136 | * If there's data, ensure we set the poll() state and publish everything | |
5137 | * to user-space before waking everybody up. | |
5138 | */ | |
5139 | ||
fed66e2c PZ |
5140 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
5141 | { | |
5142 | /* only the parent has fasync state */ | |
5143 | if (event->parent) | |
5144 | event = event->parent; | |
5145 | return &event->fasync; | |
5146 | } | |
5147 | ||
cdd6c482 | 5148 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 5149 | { |
10c6db11 | 5150 | ring_buffer_wakeup(event); |
4c9e2542 | 5151 | |
cdd6c482 | 5152 | if (event->pending_kill) { |
fed66e2c | 5153 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 5154 | event->pending_kill = 0; |
4c9e2542 | 5155 | } |
925d519a PZ |
5156 | } |
5157 | ||
e360adbe | 5158 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 5159 | { |
cdd6c482 IM |
5160 | struct perf_event *event = container_of(entry, |
5161 | struct perf_event, pending); | |
d525211f PZ |
5162 | int rctx; |
5163 | ||
5164 | rctx = perf_swevent_get_recursion_context(); | |
5165 | /* | |
5166 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
5167 | * and we won't recurse 'further'. | |
5168 | */ | |
79f14641 | 5169 | |
cdd6c482 IM |
5170 | if (event->pending_disable) { |
5171 | event->pending_disable = 0; | |
fae3fde6 | 5172 | perf_event_disable_local(event); |
79f14641 PZ |
5173 | } |
5174 | ||
cdd6c482 IM |
5175 | if (event->pending_wakeup) { |
5176 | event->pending_wakeup = 0; | |
5177 | perf_event_wakeup(event); | |
79f14641 | 5178 | } |
d525211f PZ |
5179 | |
5180 | if (rctx >= 0) | |
5181 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
5182 | } |
5183 | ||
39447b38 ZY |
5184 | /* |
5185 | * We assume there is only KVM supporting the callbacks. | |
5186 | * Later on, we might change it to a list if there is | |
5187 | * another virtualization implementation supporting the callbacks. | |
5188 | */ | |
5189 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
5190 | ||
5191 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5192 | { | |
5193 | perf_guest_cbs = cbs; | |
5194 | return 0; | |
5195 | } | |
5196 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
5197 | ||
5198 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5199 | { | |
5200 | perf_guest_cbs = NULL; | |
5201 | return 0; | |
5202 | } | |
5203 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5204 | ||
4018994f JO |
5205 | static void |
5206 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5207 | struct pt_regs *regs, u64 mask) | |
5208 | { | |
5209 | int bit; | |
5210 | ||
5211 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
5212 | sizeof(mask) * BITS_PER_BYTE) { | |
5213 | u64 val; | |
5214 | ||
5215 | val = perf_reg_value(regs, bit); | |
5216 | perf_output_put(handle, val); | |
5217 | } | |
5218 | } | |
5219 | ||
60e2364e | 5220 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5221 | struct pt_regs *regs, |
5222 | struct pt_regs *regs_user_copy) | |
4018994f | 5223 | { |
88a7c26a AL |
5224 | if (user_mode(regs)) { |
5225 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5226 | regs_user->regs = regs; |
88a7c26a AL |
5227 | } else if (current->mm) { |
5228 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5229 | } else { |
5230 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5231 | regs_user->regs = NULL; | |
4018994f JO |
5232 | } |
5233 | } | |
5234 | ||
60e2364e SE |
5235 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5236 | struct pt_regs *regs) | |
5237 | { | |
5238 | regs_intr->regs = regs; | |
5239 | regs_intr->abi = perf_reg_abi(current); | |
5240 | } | |
5241 | ||
5242 | ||
c5ebcedb JO |
5243 | /* |
5244 | * Get remaining task size from user stack pointer. | |
5245 | * | |
5246 | * It'd be better to take stack vma map and limit this more | |
5247 | * precisly, but there's no way to get it safely under interrupt, | |
5248 | * so using TASK_SIZE as limit. | |
5249 | */ | |
5250 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5251 | { | |
5252 | unsigned long addr = perf_user_stack_pointer(regs); | |
5253 | ||
5254 | if (!addr || addr >= TASK_SIZE) | |
5255 | return 0; | |
5256 | ||
5257 | return TASK_SIZE - addr; | |
5258 | } | |
5259 | ||
5260 | static u16 | |
5261 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5262 | struct pt_regs *regs) | |
5263 | { | |
5264 | u64 task_size; | |
5265 | ||
5266 | /* No regs, no stack pointer, no dump. */ | |
5267 | if (!regs) | |
5268 | return 0; | |
5269 | ||
5270 | /* | |
5271 | * Check if we fit in with the requested stack size into the: | |
5272 | * - TASK_SIZE | |
5273 | * If we don't, we limit the size to the TASK_SIZE. | |
5274 | * | |
5275 | * - remaining sample size | |
5276 | * If we don't, we customize the stack size to | |
5277 | * fit in to the remaining sample size. | |
5278 | */ | |
5279 | ||
5280 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5281 | stack_size = min(stack_size, (u16) task_size); | |
5282 | ||
5283 | /* Current header size plus static size and dynamic size. */ | |
5284 | header_size += 2 * sizeof(u64); | |
5285 | ||
5286 | /* Do we fit in with the current stack dump size? */ | |
5287 | if ((u16) (header_size + stack_size) < header_size) { | |
5288 | /* | |
5289 | * If we overflow the maximum size for the sample, | |
5290 | * we customize the stack dump size to fit in. | |
5291 | */ | |
5292 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5293 | stack_size = round_up(stack_size, sizeof(u64)); | |
5294 | } | |
5295 | ||
5296 | return stack_size; | |
5297 | } | |
5298 | ||
5299 | static void | |
5300 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5301 | struct pt_regs *regs) | |
5302 | { | |
5303 | /* Case of a kernel thread, nothing to dump */ | |
5304 | if (!regs) { | |
5305 | u64 size = 0; | |
5306 | perf_output_put(handle, size); | |
5307 | } else { | |
5308 | unsigned long sp; | |
5309 | unsigned int rem; | |
5310 | u64 dyn_size; | |
5311 | ||
5312 | /* | |
5313 | * We dump: | |
5314 | * static size | |
5315 | * - the size requested by user or the best one we can fit | |
5316 | * in to the sample max size | |
5317 | * data | |
5318 | * - user stack dump data | |
5319 | * dynamic size | |
5320 | * - the actual dumped size | |
5321 | */ | |
5322 | ||
5323 | /* Static size. */ | |
5324 | perf_output_put(handle, dump_size); | |
5325 | ||
5326 | /* Data. */ | |
5327 | sp = perf_user_stack_pointer(regs); | |
5328 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5329 | dyn_size = dump_size - rem; | |
5330 | ||
5331 | perf_output_skip(handle, rem); | |
5332 | ||
5333 | /* Dynamic size. */ | |
5334 | perf_output_put(handle, dyn_size); | |
5335 | } | |
5336 | } | |
5337 | ||
c980d109 ACM |
5338 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5339 | struct perf_sample_data *data, | |
5340 | struct perf_event *event) | |
6844c09d ACM |
5341 | { |
5342 | u64 sample_type = event->attr.sample_type; | |
5343 | ||
5344 | data->type = sample_type; | |
5345 | header->size += event->id_header_size; | |
5346 | ||
5347 | if (sample_type & PERF_SAMPLE_TID) { | |
5348 | /* namespace issues */ | |
5349 | data->tid_entry.pid = perf_event_pid(event, current); | |
5350 | data->tid_entry.tid = perf_event_tid(event, current); | |
5351 | } | |
5352 | ||
5353 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5354 | data->time = perf_event_clock(event); |
6844c09d | 5355 | |
ff3d527c | 5356 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5357 | data->id = primary_event_id(event); |
5358 | ||
5359 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5360 | data->stream_id = event->id; | |
5361 | ||
5362 | if (sample_type & PERF_SAMPLE_CPU) { | |
5363 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5364 | data->cpu_entry.reserved = 0; | |
5365 | } | |
5366 | } | |
5367 | ||
76369139 FW |
5368 | void perf_event_header__init_id(struct perf_event_header *header, |
5369 | struct perf_sample_data *data, | |
5370 | struct perf_event *event) | |
c980d109 ACM |
5371 | { |
5372 | if (event->attr.sample_id_all) | |
5373 | __perf_event_header__init_id(header, data, event); | |
5374 | } | |
5375 | ||
5376 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5377 | struct perf_sample_data *data) | |
5378 | { | |
5379 | u64 sample_type = data->type; | |
5380 | ||
5381 | if (sample_type & PERF_SAMPLE_TID) | |
5382 | perf_output_put(handle, data->tid_entry); | |
5383 | ||
5384 | if (sample_type & PERF_SAMPLE_TIME) | |
5385 | perf_output_put(handle, data->time); | |
5386 | ||
5387 | if (sample_type & PERF_SAMPLE_ID) | |
5388 | perf_output_put(handle, data->id); | |
5389 | ||
5390 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5391 | perf_output_put(handle, data->stream_id); | |
5392 | ||
5393 | if (sample_type & PERF_SAMPLE_CPU) | |
5394 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5395 | |
5396 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5397 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5398 | } |
5399 | ||
76369139 FW |
5400 | void perf_event__output_id_sample(struct perf_event *event, |
5401 | struct perf_output_handle *handle, | |
5402 | struct perf_sample_data *sample) | |
c980d109 ACM |
5403 | { |
5404 | if (event->attr.sample_id_all) | |
5405 | __perf_event__output_id_sample(handle, sample); | |
5406 | } | |
5407 | ||
3dab77fb | 5408 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5409 | struct perf_event *event, |
5410 | u64 enabled, u64 running) | |
3dab77fb | 5411 | { |
cdd6c482 | 5412 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5413 | u64 values[4]; |
5414 | int n = 0; | |
5415 | ||
b5e58793 | 5416 | values[n++] = perf_event_count(event); |
3dab77fb | 5417 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5418 | values[n++] = enabled + |
cdd6c482 | 5419 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5420 | } |
5421 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5422 | values[n++] = running + |
cdd6c482 | 5423 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5424 | } |
5425 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5426 | values[n++] = primary_event_id(event); |
3dab77fb | 5427 | |
76369139 | 5428 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5429 | } |
5430 | ||
5431 | /* | |
cdd6c482 | 5432 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5433 | */ |
5434 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5435 | struct perf_event *event, |
5436 | u64 enabled, u64 running) | |
3dab77fb | 5437 | { |
cdd6c482 IM |
5438 | struct perf_event *leader = event->group_leader, *sub; |
5439 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5440 | u64 values[5]; |
5441 | int n = 0; | |
5442 | ||
5443 | values[n++] = 1 + leader->nr_siblings; | |
5444 | ||
5445 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5446 | values[n++] = enabled; |
3dab77fb PZ |
5447 | |
5448 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5449 | values[n++] = running; |
3dab77fb | 5450 | |
cdd6c482 | 5451 | if (leader != event) |
3dab77fb PZ |
5452 | leader->pmu->read(leader); |
5453 | ||
b5e58793 | 5454 | values[n++] = perf_event_count(leader); |
3dab77fb | 5455 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5456 | values[n++] = primary_event_id(leader); |
3dab77fb | 5457 | |
76369139 | 5458 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5459 | |
65abc865 | 5460 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5461 | n = 0; |
5462 | ||
6f5ab001 JO |
5463 | if ((sub != event) && |
5464 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5465 | sub->pmu->read(sub); |
5466 | ||
b5e58793 | 5467 | values[n++] = perf_event_count(sub); |
3dab77fb | 5468 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5469 | values[n++] = primary_event_id(sub); |
3dab77fb | 5470 | |
76369139 | 5471 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5472 | } |
5473 | } | |
5474 | ||
eed01528 SE |
5475 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5476 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5477 | ||
3dab77fb | 5478 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5479 | struct perf_event *event) |
3dab77fb | 5480 | { |
e3f3541c | 5481 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5482 | u64 read_format = event->attr.read_format; |
5483 | ||
5484 | /* | |
5485 | * compute total_time_enabled, total_time_running | |
5486 | * based on snapshot values taken when the event | |
5487 | * was last scheduled in. | |
5488 | * | |
5489 | * we cannot simply called update_context_time() | |
5490 | * because of locking issue as we are called in | |
5491 | * NMI context | |
5492 | */ | |
c4794295 | 5493 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5494 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5495 | |
cdd6c482 | 5496 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5497 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5498 | else |
eed01528 | 5499 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5500 | } |
5501 | ||
5622f295 MM |
5502 | void perf_output_sample(struct perf_output_handle *handle, |
5503 | struct perf_event_header *header, | |
5504 | struct perf_sample_data *data, | |
cdd6c482 | 5505 | struct perf_event *event) |
5622f295 MM |
5506 | { |
5507 | u64 sample_type = data->type; | |
5508 | ||
5509 | perf_output_put(handle, *header); | |
5510 | ||
ff3d527c AH |
5511 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5512 | perf_output_put(handle, data->id); | |
5513 | ||
5622f295 MM |
5514 | if (sample_type & PERF_SAMPLE_IP) |
5515 | perf_output_put(handle, data->ip); | |
5516 | ||
5517 | if (sample_type & PERF_SAMPLE_TID) | |
5518 | perf_output_put(handle, data->tid_entry); | |
5519 | ||
5520 | if (sample_type & PERF_SAMPLE_TIME) | |
5521 | perf_output_put(handle, data->time); | |
5522 | ||
5523 | if (sample_type & PERF_SAMPLE_ADDR) | |
5524 | perf_output_put(handle, data->addr); | |
5525 | ||
5526 | if (sample_type & PERF_SAMPLE_ID) | |
5527 | perf_output_put(handle, data->id); | |
5528 | ||
5529 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5530 | perf_output_put(handle, data->stream_id); | |
5531 | ||
5532 | if (sample_type & PERF_SAMPLE_CPU) | |
5533 | perf_output_put(handle, data->cpu_entry); | |
5534 | ||
5535 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5536 | perf_output_put(handle, data->period); | |
5537 | ||
5538 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5539 | perf_output_read(handle, event); |
5622f295 MM |
5540 | |
5541 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5542 | if (data->callchain) { | |
5543 | int size = 1; | |
5544 | ||
5545 | if (data->callchain) | |
5546 | size += data->callchain->nr; | |
5547 | ||
5548 | size *= sizeof(u64); | |
5549 | ||
76369139 | 5550 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5551 | } else { |
5552 | u64 nr = 0; | |
5553 | perf_output_put(handle, nr); | |
5554 | } | |
5555 | } | |
5556 | ||
5557 | if (sample_type & PERF_SAMPLE_RAW) { | |
5558 | if (data->raw) { | |
fa128e6a AS |
5559 | u32 raw_size = data->raw->size; |
5560 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5561 | sizeof(u64)) - sizeof(u32); | |
5562 | u64 zero = 0; | |
5563 | ||
5564 | perf_output_put(handle, real_size); | |
5565 | __output_copy(handle, data->raw->data, raw_size); | |
5566 | if (real_size - raw_size) | |
5567 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5568 | } else { |
5569 | struct { | |
5570 | u32 size; | |
5571 | u32 data; | |
5572 | } raw = { | |
5573 | .size = sizeof(u32), | |
5574 | .data = 0, | |
5575 | }; | |
5576 | perf_output_put(handle, raw); | |
5577 | } | |
5578 | } | |
a7ac67ea | 5579 | |
bce38cd5 SE |
5580 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5581 | if (data->br_stack) { | |
5582 | size_t size; | |
5583 | ||
5584 | size = data->br_stack->nr | |
5585 | * sizeof(struct perf_branch_entry); | |
5586 | ||
5587 | perf_output_put(handle, data->br_stack->nr); | |
5588 | perf_output_copy(handle, data->br_stack->entries, size); | |
5589 | } else { | |
5590 | /* | |
5591 | * we always store at least the value of nr | |
5592 | */ | |
5593 | u64 nr = 0; | |
5594 | perf_output_put(handle, nr); | |
5595 | } | |
5596 | } | |
4018994f JO |
5597 | |
5598 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5599 | u64 abi = data->regs_user.abi; | |
5600 | ||
5601 | /* | |
5602 | * If there are no regs to dump, notice it through | |
5603 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5604 | */ | |
5605 | perf_output_put(handle, abi); | |
5606 | ||
5607 | if (abi) { | |
5608 | u64 mask = event->attr.sample_regs_user; | |
5609 | perf_output_sample_regs(handle, | |
5610 | data->regs_user.regs, | |
5611 | mask); | |
5612 | } | |
5613 | } | |
c5ebcedb | 5614 | |
a5cdd40c | 5615 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5616 | perf_output_sample_ustack(handle, |
5617 | data->stack_user_size, | |
5618 | data->regs_user.regs); | |
a5cdd40c | 5619 | } |
c3feedf2 AK |
5620 | |
5621 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5622 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5623 | |
5624 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5625 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5626 | |
fdfbbd07 AK |
5627 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5628 | perf_output_put(handle, data->txn); | |
5629 | ||
60e2364e SE |
5630 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5631 | u64 abi = data->regs_intr.abi; | |
5632 | /* | |
5633 | * If there are no regs to dump, notice it through | |
5634 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5635 | */ | |
5636 | perf_output_put(handle, abi); | |
5637 | ||
5638 | if (abi) { | |
5639 | u64 mask = event->attr.sample_regs_intr; | |
5640 | ||
5641 | perf_output_sample_regs(handle, | |
5642 | data->regs_intr.regs, | |
5643 | mask); | |
5644 | } | |
5645 | } | |
5646 | ||
a5cdd40c PZ |
5647 | if (!event->attr.watermark) { |
5648 | int wakeup_events = event->attr.wakeup_events; | |
5649 | ||
5650 | if (wakeup_events) { | |
5651 | struct ring_buffer *rb = handle->rb; | |
5652 | int events = local_inc_return(&rb->events); | |
5653 | ||
5654 | if (events >= wakeup_events) { | |
5655 | local_sub(wakeup_events, &rb->events); | |
5656 | local_inc(&rb->wakeup); | |
5657 | } | |
5658 | } | |
5659 | } | |
5622f295 MM |
5660 | } |
5661 | ||
5662 | void perf_prepare_sample(struct perf_event_header *header, | |
5663 | struct perf_sample_data *data, | |
cdd6c482 | 5664 | struct perf_event *event, |
5622f295 | 5665 | struct pt_regs *regs) |
7b732a75 | 5666 | { |
cdd6c482 | 5667 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5668 | |
cdd6c482 | 5669 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5670 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5671 | |
5672 | header->misc = 0; | |
5673 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5674 | |
c980d109 | 5675 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5676 | |
c320c7b7 | 5677 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5678 | data->ip = perf_instruction_pointer(regs); |
5679 | ||
b23f3325 | 5680 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5681 | int size = 1; |
394ee076 | 5682 | |
e6dab5ff | 5683 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5684 | |
5685 | if (data->callchain) | |
5686 | size += data->callchain->nr; | |
5687 | ||
5688 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5689 | } |
5690 | ||
3a43ce68 | 5691 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5692 | int size = sizeof(u32); |
5693 | ||
5694 | if (data->raw) | |
5695 | size += data->raw->size; | |
5696 | else | |
5697 | size += sizeof(u32); | |
5698 | ||
fa128e6a | 5699 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5700 | } |
bce38cd5 SE |
5701 | |
5702 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5703 | int size = sizeof(u64); /* nr */ | |
5704 | if (data->br_stack) { | |
5705 | size += data->br_stack->nr | |
5706 | * sizeof(struct perf_branch_entry); | |
5707 | } | |
5708 | header->size += size; | |
5709 | } | |
4018994f | 5710 | |
2565711f | 5711 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5712 | perf_sample_regs_user(&data->regs_user, regs, |
5713 | &data->regs_user_copy); | |
2565711f | 5714 | |
4018994f JO |
5715 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5716 | /* regs dump ABI info */ | |
5717 | int size = sizeof(u64); | |
5718 | ||
4018994f JO |
5719 | if (data->regs_user.regs) { |
5720 | u64 mask = event->attr.sample_regs_user; | |
5721 | size += hweight64(mask) * sizeof(u64); | |
5722 | } | |
5723 | ||
5724 | header->size += size; | |
5725 | } | |
c5ebcedb JO |
5726 | |
5727 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5728 | /* | |
5729 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5730 | * processed as the last one or have additional check added | |
5731 | * in case new sample type is added, because we could eat | |
5732 | * up the rest of the sample size. | |
5733 | */ | |
c5ebcedb JO |
5734 | u16 stack_size = event->attr.sample_stack_user; |
5735 | u16 size = sizeof(u64); | |
5736 | ||
c5ebcedb | 5737 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5738 | data->regs_user.regs); |
c5ebcedb JO |
5739 | |
5740 | /* | |
5741 | * If there is something to dump, add space for the dump | |
5742 | * itself and for the field that tells the dynamic size, | |
5743 | * which is how many have been actually dumped. | |
5744 | */ | |
5745 | if (stack_size) | |
5746 | size += sizeof(u64) + stack_size; | |
5747 | ||
5748 | data->stack_user_size = stack_size; | |
5749 | header->size += size; | |
5750 | } | |
60e2364e SE |
5751 | |
5752 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5753 | /* regs dump ABI info */ | |
5754 | int size = sizeof(u64); | |
5755 | ||
5756 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5757 | ||
5758 | if (data->regs_intr.regs) { | |
5759 | u64 mask = event->attr.sample_regs_intr; | |
5760 | ||
5761 | size += hweight64(mask) * sizeof(u64); | |
5762 | } | |
5763 | ||
5764 | header->size += size; | |
5765 | } | |
5622f295 | 5766 | } |
7f453c24 | 5767 | |
9ecda41a WN |
5768 | static void __always_inline |
5769 | __perf_event_output(struct perf_event *event, | |
5770 | struct perf_sample_data *data, | |
5771 | struct pt_regs *regs, | |
5772 | int (*output_begin)(struct perf_output_handle *, | |
5773 | struct perf_event *, | |
5774 | unsigned int)) | |
5622f295 MM |
5775 | { |
5776 | struct perf_output_handle handle; | |
5777 | struct perf_event_header header; | |
689802b2 | 5778 | |
927c7a9e FW |
5779 | /* protect the callchain buffers */ |
5780 | rcu_read_lock(); | |
5781 | ||
cdd6c482 | 5782 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5783 | |
9ecda41a | 5784 | if (output_begin(&handle, event, header.size)) |
927c7a9e | 5785 | goto exit; |
0322cd6e | 5786 | |
cdd6c482 | 5787 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5788 | |
8a057d84 | 5789 | perf_output_end(&handle); |
927c7a9e FW |
5790 | |
5791 | exit: | |
5792 | rcu_read_unlock(); | |
0322cd6e PZ |
5793 | } |
5794 | ||
9ecda41a WN |
5795 | void |
5796 | perf_event_output_forward(struct perf_event *event, | |
5797 | struct perf_sample_data *data, | |
5798 | struct pt_regs *regs) | |
5799 | { | |
5800 | __perf_event_output(event, data, regs, perf_output_begin_forward); | |
5801 | } | |
5802 | ||
5803 | void | |
5804 | perf_event_output_backward(struct perf_event *event, | |
5805 | struct perf_sample_data *data, | |
5806 | struct pt_regs *regs) | |
5807 | { | |
5808 | __perf_event_output(event, data, regs, perf_output_begin_backward); | |
5809 | } | |
5810 | ||
5811 | void | |
5812 | perf_event_output(struct perf_event *event, | |
5813 | struct perf_sample_data *data, | |
5814 | struct pt_regs *regs) | |
5815 | { | |
5816 | __perf_event_output(event, data, regs, perf_output_begin); | |
5817 | } | |
5818 | ||
38b200d6 | 5819 | /* |
cdd6c482 | 5820 | * read event_id |
38b200d6 PZ |
5821 | */ |
5822 | ||
5823 | struct perf_read_event { | |
5824 | struct perf_event_header header; | |
5825 | ||
5826 | u32 pid; | |
5827 | u32 tid; | |
38b200d6 PZ |
5828 | }; |
5829 | ||
5830 | static void | |
cdd6c482 | 5831 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5832 | struct task_struct *task) |
5833 | { | |
5834 | struct perf_output_handle handle; | |
c980d109 | 5835 | struct perf_sample_data sample; |
dfc65094 | 5836 | struct perf_read_event read_event = { |
38b200d6 | 5837 | .header = { |
cdd6c482 | 5838 | .type = PERF_RECORD_READ, |
38b200d6 | 5839 | .misc = 0, |
c320c7b7 | 5840 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5841 | }, |
cdd6c482 IM |
5842 | .pid = perf_event_pid(event, task), |
5843 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5844 | }; |
3dab77fb | 5845 | int ret; |
38b200d6 | 5846 | |
c980d109 | 5847 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5848 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5849 | if (ret) |
5850 | return; | |
5851 | ||
dfc65094 | 5852 | perf_output_put(&handle, read_event); |
cdd6c482 | 5853 | perf_output_read(&handle, event); |
c980d109 | 5854 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5855 | |
38b200d6 PZ |
5856 | perf_output_end(&handle); |
5857 | } | |
5858 | ||
52d857a8 JO |
5859 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5860 | ||
5861 | static void | |
5862 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 | 5863 | perf_event_aux_output_cb output, |
b73e4fef | 5864 | void *data, bool all) |
52d857a8 JO |
5865 | { |
5866 | struct perf_event *event; | |
5867 | ||
5868 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
b73e4fef AS |
5869 | if (!all) { |
5870 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5871 | continue; | |
5872 | if (!event_filter_match(event)) | |
5873 | continue; | |
5874 | } | |
5875 | ||
67516844 | 5876 | output(event, data); |
52d857a8 JO |
5877 | } |
5878 | } | |
5879 | ||
4e93ad60 JO |
5880 | static void |
5881 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5882 | struct perf_event_context *task_ctx) | |
5883 | { | |
5884 | rcu_read_lock(); | |
5885 | preempt_disable(); | |
b73e4fef | 5886 | perf_event_aux_ctx(task_ctx, output, data, false); |
4e93ad60 JO |
5887 | preempt_enable(); |
5888 | rcu_read_unlock(); | |
5889 | } | |
5890 | ||
52d857a8 | 5891 | static void |
67516844 | 5892 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5893 | struct perf_event_context *task_ctx) |
5894 | { | |
5895 | struct perf_cpu_context *cpuctx; | |
5896 | struct perf_event_context *ctx; | |
5897 | struct pmu *pmu; | |
5898 | int ctxn; | |
5899 | ||
4e93ad60 JO |
5900 | /* |
5901 | * If we have task_ctx != NULL we only notify | |
5902 | * the task context itself. The task_ctx is set | |
5903 | * only for EXIT events before releasing task | |
5904 | * context. | |
5905 | */ | |
5906 | if (task_ctx) { | |
5907 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5908 | return; | |
5909 | } | |
5910 | ||
52d857a8 JO |
5911 | rcu_read_lock(); |
5912 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5913 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5914 | if (cpuctx->unique_pmu != pmu) | |
5915 | goto next; | |
b73e4fef | 5916 | perf_event_aux_ctx(&cpuctx->ctx, output, data, false); |
52d857a8 JO |
5917 | ctxn = pmu->task_ctx_nr; |
5918 | if (ctxn < 0) | |
5919 | goto next; | |
5920 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5921 | if (ctx) | |
b73e4fef | 5922 | perf_event_aux_ctx(ctx, output, data, false); |
52d857a8 JO |
5923 | next: |
5924 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5925 | } | |
52d857a8 | 5926 | rcu_read_unlock(); |
95ff4ca2 AS |
5927 | } |
5928 | ||
375637bc AS |
5929 | /* |
5930 | * Clear all file-based filters at exec, they'll have to be | |
5931 | * re-instated when/if these objects are mmapped again. | |
5932 | */ | |
5933 | static void perf_event_addr_filters_exec(struct perf_event *event, void *data) | |
5934 | { | |
5935 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
5936 | struct perf_addr_filter *filter; | |
5937 | unsigned int restart = 0, count = 0; | |
5938 | unsigned long flags; | |
5939 | ||
5940 | if (!has_addr_filter(event)) | |
5941 | return; | |
5942 | ||
5943 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
5944 | list_for_each_entry(filter, &ifh->list, entry) { | |
5945 | if (filter->inode) { | |
5946 | event->addr_filters_offs[count] = 0; | |
5947 | restart++; | |
5948 | } | |
5949 | ||
5950 | count++; | |
5951 | } | |
5952 | ||
5953 | if (restart) | |
5954 | event->addr_filters_gen++; | |
5955 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
5956 | ||
5957 | if (restart) | |
5958 | perf_event_restart(event); | |
5959 | } | |
5960 | ||
5961 | void perf_event_exec(void) | |
5962 | { | |
5963 | struct perf_event_context *ctx; | |
5964 | int ctxn; | |
5965 | ||
5966 | rcu_read_lock(); | |
5967 | for_each_task_context_nr(ctxn) { | |
5968 | ctx = current->perf_event_ctxp[ctxn]; | |
5969 | if (!ctx) | |
5970 | continue; | |
5971 | ||
5972 | perf_event_enable_on_exec(ctxn); | |
5973 | ||
5974 | perf_event_aux_ctx(ctx, perf_event_addr_filters_exec, NULL, | |
5975 | true); | |
5976 | } | |
5977 | rcu_read_unlock(); | |
5978 | } | |
5979 | ||
95ff4ca2 AS |
5980 | struct remote_output { |
5981 | struct ring_buffer *rb; | |
5982 | int err; | |
5983 | }; | |
5984 | ||
5985 | static void __perf_event_output_stop(struct perf_event *event, void *data) | |
5986 | { | |
5987 | struct perf_event *parent = event->parent; | |
5988 | struct remote_output *ro = data; | |
5989 | struct ring_buffer *rb = ro->rb; | |
375637bc AS |
5990 | struct stop_event_data sd = { |
5991 | .event = event, | |
5992 | }; | |
95ff4ca2 AS |
5993 | |
5994 | if (!has_aux(event)) | |
5995 | return; | |
5996 | ||
5997 | if (!parent) | |
5998 | parent = event; | |
5999 | ||
6000 | /* | |
6001 | * In case of inheritance, it will be the parent that links to the | |
6002 | * ring-buffer, but it will be the child that's actually using it: | |
6003 | */ | |
6004 | if (rcu_dereference(parent->rb) == rb) | |
375637bc | 6005 | ro->err = __perf_event_stop(&sd); |
95ff4ca2 AS |
6006 | } |
6007 | ||
6008 | static int __perf_pmu_output_stop(void *info) | |
6009 | { | |
6010 | struct perf_event *event = info; | |
6011 | struct pmu *pmu = event->pmu; | |
6012 | struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
6013 | struct remote_output ro = { | |
6014 | .rb = event->rb, | |
6015 | }; | |
6016 | ||
6017 | rcu_read_lock(); | |
b73e4fef | 6018 | perf_event_aux_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false); |
95ff4ca2 AS |
6019 | if (cpuctx->task_ctx) |
6020 | perf_event_aux_ctx(cpuctx->task_ctx, __perf_event_output_stop, | |
b73e4fef | 6021 | &ro, false); |
95ff4ca2 AS |
6022 | rcu_read_unlock(); |
6023 | ||
6024 | return ro.err; | |
6025 | } | |
6026 | ||
6027 | static void perf_pmu_output_stop(struct perf_event *event) | |
6028 | { | |
6029 | struct perf_event *iter; | |
6030 | int err, cpu; | |
6031 | ||
6032 | restart: | |
6033 | rcu_read_lock(); | |
6034 | list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { | |
6035 | /* | |
6036 | * For per-CPU events, we need to make sure that neither they | |
6037 | * nor their children are running; for cpu==-1 events it's | |
6038 | * sufficient to stop the event itself if it's active, since | |
6039 | * it can't have children. | |
6040 | */ | |
6041 | cpu = iter->cpu; | |
6042 | if (cpu == -1) | |
6043 | cpu = READ_ONCE(iter->oncpu); | |
6044 | ||
6045 | if (cpu == -1) | |
6046 | continue; | |
6047 | ||
6048 | err = cpu_function_call(cpu, __perf_pmu_output_stop, event); | |
6049 | if (err == -EAGAIN) { | |
6050 | rcu_read_unlock(); | |
6051 | goto restart; | |
6052 | } | |
6053 | } | |
6054 | rcu_read_unlock(); | |
52d857a8 JO |
6055 | } |
6056 | ||
60313ebe | 6057 | /* |
9f498cc5 PZ |
6058 | * task tracking -- fork/exit |
6059 | * | |
13d7a241 | 6060 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
6061 | */ |
6062 | ||
9f498cc5 | 6063 | struct perf_task_event { |
3a80b4a3 | 6064 | struct task_struct *task; |
cdd6c482 | 6065 | struct perf_event_context *task_ctx; |
60313ebe PZ |
6066 | |
6067 | struct { | |
6068 | struct perf_event_header header; | |
6069 | ||
6070 | u32 pid; | |
6071 | u32 ppid; | |
9f498cc5 PZ |
6072 | u32 tid; |
6073 | u32 ptid; | |
393b2ad8 | 6074 | u64 time; |
cdd6c482 | 6075 | } event_id; |
60313ebe PZ |
6076 | }; |
6077 | ||
67516844 JO |
6078 | static int perf_event_task_match(struct perf_event *event) |
6079 | { | |
13d7a241 SE |
6080 | return event->attr.comm || event->attr.mmap || |
6081 | event->attr.mmap2 || event->attr.mmap_data || | |
6082 | event->attr.task; | |
67516844 JO |
6083 | } |
6084 | ||
cdd6c482 | 6085 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 6086 | void *data) |
60313ebe | 6087 | { |
52d857a8 | 6088 | struct perf_task_event *task_event = data; |
60313ebe | 6089 | struct perf_output_handle handle; |
c980d109 | 6090 | struct perf_sample_data sample; |
9f498cc5 | 6091 | struct task_struct *task = task_event->task; |
c980d109 | 6092 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 6093 | |
67516844 JO |
6094 | if (!perf_event_task_match(event)) |
6095 | return; | |
6096 | ||
c980d109 | 6097 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 6098 | |
c980d109 | 6099 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 6100 | task_event->event_id.header.size); |
ef60777c | 6101 | if (ret) |
c980d109 | 6102 | goto out; |
60313ebe | 6103 | |
cdd6c482 IM |
6104 | task_event->event_id.pid = perf_event_pid(event, task); |
6105 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 6106 | |
cdd6c482 IM |
6107 | task_event->event_id.tid = perf_event_tid(event, task); |
6108 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 6109 | |
34f43927 PZ |
6110 | task_event->event_id.time = perf_event_clock(event); |
6111 | ||
cdd6c482 | 6112 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 6113 | |
c980d109 ACM |
6114 | perf_event__output_id_sample(event, &handle, &sample); |
6115 | ||
60313ebe | 6116 | perf_output_end(&handle); |
c980d109 ACM |
6117 | out: |
6118 | task_event->event_id.header.size = size; | |
60313ebe PZ |
6119 | } |
6120 | ||
cdd6c482 IM |
6121 | static void perf_event_task(struct task_struct *task, |
6122 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 6123 | int new) |
60313ebe | 6124 | { |
9f498cc5 | 6125 | struct perf_task_event task_event; |
60313ebe | 6126 | |
cdd6c482 IM |
6127 | if (!atomic_read(&nr_comm_events) && |
6128 | !atomic_read(&nr_mmap_events) && | |
6129 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
6130 | return; |
6131 | ||
9f498cc5 | 6132 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
6133 | .task = task, |
6134 | .task_ctx = task_ctx, | |
cdd6c482 | 6135 | .event_id = { |
60313ebe | 6136 | .header = { |
cdd6c482 | 6137 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 6138 | .misc = 0, |
cdd6c482 | 6139 | .size = sizeof(task_event.event_id), |
60313ebe | 6140 | }, |
573402db PZ |
6141 | /* .pid */ |
6142 | /* .ppid */ | |
9f498cc5 PZ |
6143 | /* .tid */ |
6144 | /* .ptid */ | |
34f43927 | 6145 | /* .time */ |
60313ebe PZ |
6146 | }, |
6147 | }; | |
6148 | ||
67516844 | 6149 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
6150 | &task_event, |
6151 | task_ctx); | |
9f498cc5 PZ |
6152 | } |
6153 | ||
cdd6c482 | 6154 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 6155 | { |
cdd6c482 | 6156 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
6157 | } |
6158 | ||
8d1b2d93 PZ |
6159 | /* |
6160 | * comm tracking | |
6161 | */ | |
6162 | ||
6163 | struct perf_comm_event { | |
22a4f650 IM |
6164 | struct task_struct *task; |
6165 | char *comm; | |
8d1b2d93 PZ |
6166 | int comm_size; |
6167 | ||
6168 | struct { | |
6169 | struct perf_event_header header; | |
6170 | ||
6171 | u32 pid; | |
6172 | u32 tid; | |
cdd6c482 | 6173 | } event_id; |
8d1b2d93 PZ |
6174 | }; |
6175 | ||
67516844 JO |
6176 | static int perf_event_comm_match(struct perf_event *event) |
6177 | { | |
6178 | return event->attr.comm; | |
6179 | } | |
6180 | ||
cdd6c482 | 6181 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 6182 | void *data) |
8d1b2d93 | 6183 | { |
52d857a8 | 6184 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 6185 | struct perf_output_handle handle; |
c980d109 | 6186 | struct perf_sample_data sample; |
cdd6c482 | 6187 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
6188 | int ret; |
6189 | ||
67516844 JO |
6190 | if (!perf_event_comm_match(event)) |
6191 | return; | |
6192 | ||
c980d109 ACM |
6193 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
6194 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6195 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
6196 | |
6197 | if (ret) | |
c980d109 | 6198 | goto out; |
8d1b2d93 | 6199 | |
cdd6c482 IM |
6200 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
6201 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 6202 | |
cdd6c482 | 6203 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 6204 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 6205 | comm_event->comm_size); |
c980d109 ACM |
6206 | |
6207 | perf_event__output_id_sample(event, &handle, &sample); | |
6208 | ||
8d1b2d93 | 6209 | perf_output_end(&handle); |
c980d109 ACM |
6210 | out: |
6211 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
6212 | } |
6213 | ||
cdd6c482 | 6214 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 6215 | { |
413ee3b4 | 6216 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 6217 | unsigned int size; |
8d1b2d93 | 6218 | |
413ee3b4 | 6219 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 6220 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 6221 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
6222 | |
6223 | comm_event->comm = comm; | |
6224 | comm_event->comm_size = size; | |
6225 | ||
cdd6c482 | 6226 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 6227 | |
67516844 | 6228 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
6229 | comm_event, |
6230 | NULL); | |
8d1b2d93 PZ |
6231 | } |
6232 | ||
82b89778 | 6233 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 6234 | { |
9ee318a7 PZ |
6235 | struct perf_comm_event comm_event; |
6236 | ||
cdd6c482 | 6237 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 6238 | return; |
a63eaf34 | 6239 | |
9ee318a7 | 6240 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 6241 | .task = task, |
573402db PZ |
6242 | /* .comm */ |
6243 | /* .comm_size */ | |
cdd6c482 | 6244 | .event_id = { |
573402db | 6245 | .header = { |
cdd6c482 | 6246 | .type = PERF_RECORD_COMM, |
82b89778 | 6247 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
6248 | /* .size */ |
6249 | }, | |
6250 | /* .pid */ | |
6251 | /* .tid */ | |
8d1b2d93 PZ |
6252 | }, |
6253 | }; | |
6254 | ||
cdd6c482 | 6255 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
6256 | } |
6257 | ||
0a4a9391 PZ |
6258 | /* |
6259 | * mmap tracking | |
6260 | */ | |
6261 | ||
6262 | struct perf_mmap_event { | |
089dd79d PZ |
6263 | struct vm_area_struct *vma; |
6264 | ||
6265 | const char *file_name; | |
6266 | int file_size; | |
13d7a241 SE |
6267 | int maj, min; |
6268 | u64 ino; | |
6269 | u64 ino_generation; | |
f972eb63 | 6270 | u32 prot, flags; |
0a4a9391 PZ |
6271 | |
6272 | struct { | |
6273 | struct perf_event_header header; | |
6274 | ||
6275 | u32 pid; | |
6276 | u32 tid; | |
6277 | u64 start; | |
6278 | u64 len; | |
6279 | u64 pgoff; | |
cdd6c482 | 6280 | } event_id; |
0a4a9391 PZ |
6281 | }; |
6282 | ||
67516844 JO |
6283 | static int perf_event_mmap_match(struct perf_event *event, |
6284 | void *data) | |
6285 | { | |
6286 | struct perf_mmap_event *mmap_event = data; | |
6287 | struct vm_area_struct *vma = mmap_event->vma; | |
6288 | int executable = vma->vm_flags & VM_EXEC; | |
6289 | ||
6290 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 6291 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
6292 | } |
6293 | ||
cdd6c482 | 6294 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 6295 | void *data) |
0a4a9391 | 6296 | { |
52d857a8 | 6297 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 6298 | struct perf_output_handle handle; |
c980d109 | 6299 | struct perf_sample_data sample; |
cdd6c482 | 6300 | int size = mmap_event->event_id.header.size; |
c980d109 | 6301 | int ret; |
0a4a9391 | 6302 | |
67516844 JO |
6303 | if (!perf_event_mmap_match(event, data)) |
6304 | return; | |
6305 | ||
13d7a241 SE |
6306 | if (event->attr.mmap2) { |
6307 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
6308 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
6309 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
6310 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 6311 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
6312 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
6313 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
6314 | } |
6315 | ||
c980d109 ACM |
6316 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
6317 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6318 | mmap_event->event_id.header.size); |
0a4a9391 | 6319 | if (ret) |
c980d109 | 6320 | goto out; |
0a4a9391 | 6321 | |
cdd6c482 IM |
6322 | mmap_event->event_id.pid = perf_event_pid(event, current); |
6323 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 6324 | |
cdd6c482 | 6325 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
6326 | |
6327 | if (event->attr.mmap2) { | |
6328 | perf_output_put(&handle, mmap_event->maj); | |
6329 | perf_output_put(&handle, mmap_event->min); | |
6330 | perf_output_put(&handle, mmap_event->ino); | |
6331 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
6332 | perf_output_put(&handle, mmap_event->prot); |
6333 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
6334 | } |
6335 | ||
76369139 | 6336 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 6337 | mmap_event->file_size); |
c980d109 ACM |
6338 | |
6339 | perf_event__output_id_sample(event, &handle, &sample); | |
6340 | ||
78d613eb | 6341 | perf_output_end(&handle); |
c980d109 ACM |
6342 | out: |
6343 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
6344 | } |
6345 | ||
cdd6c482 | 6346 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 6347 | { |
089dd79d PZ |
6348 | struct vm_area_struct *vma = mmap_event->vma; |
6349 | struct file *file = vma->vm_file; | |
13d7a241 SE |
6350 | int maj = 0, min = 0; |
6351 | u64 ino = 0, gen = 0; | |
f972eb63 | 6352 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
6353 | unsigned int size; |
6354 | char tmp[16]; | |
6355 | char *buf = NULL; | |
2c42cfbf | 6356 | char *name; |
413ee3b4 | 6357 | |
0a4a9391 | 6358 | if (file) { |
13d7a241 SE |
6359 | struct inode *inode; |
6360 | dev_t dev; | |
3ea2f2b9 | 6361 | |
2c42cfbf | 6362 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 6363 | if (!buf) { |
c7e548b4 ON |
6364 | name = "//enomem"; |
6365 | goto cpy_name; | |
0a4a9391 | 6366 | } |
413ee3b4 | 6367 | /* |
3ea2f2b9 | 6368 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
6369 | * need to add enough zero bytes after the string to handle |
6370 | * the 64bit alignment we do later. | |
6371 | */ | |
9bf39ab2 | 6372 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 6373 | if (IS_ERR(name)) { |
c7e548b4 ON |
6374 | name = "//toolong"; |
6375 | goto cpy_name; | |
0a4a9391 | 6376 | } |
13d7a241 SE |
6377 | inode = file_inode(vma->vm_file); |
6378 | dev = inode->i_sb->s_dev; | |
6379 | ino = inode->i_ino; | |
6380 | gen = inode->i_generation; | |
6381 | maj = MAJOR(dev); | |
6382 | min = MINOR(dev); | |
f972eb63 PZ |
6383 | |
6384 | if (vma->vm_flags & VM_READ) | |
6385 | prot |= PROT_READ; | |
6386 | if (vma->vm_flags & VM_WRITE) | |
6387 | prot |= PROT_WRITE; | |
6388 | if (vma->vm_flags & VM_EXEC) | |
6389 | prot |= PROT_EXEC; | |
6390 | ||
6391 | if (vma->vm_flags & VM_MAYSHARE) | |
6392 | flags = MAP_SHARED; | |
6393 | else | |
6394 | flags = MAP_PRIVATE; | |
6395 | ||
6396 | if (vma->vm_flags & VM_DENYWRITE) | |
6397 | flags |= MAP_DENYWRITE; | |
6398 | if (vma->vm_flags & VM_MAYEXEC) | |
6399 | flags |= MAP_EXECUTABLE; | |
6400 | if (vma->vm_flags & VM_LOCKED) | |
6401 | flags |= MAP_LOCKED; | |
6402 | if (vma->vm_flags & VM_HUGETLB) | |
6403 | flags |= MAP_HUGETLB; | |
6404 | ||
c7e548b4 | 6405 | goto got_name; |
0a4a9391 | 6406 | } else { |
fbe26abe JO |
6407 | if (vma->vm_ops && vma->vm_ops->name) { |
6408 | name = (char *) vma->vm_ops->name(vma); | |
6409 | if (name) | |
6410 | goto cpy_name; | |
6411 | } | |
6412 | ||
2c42cfbf | 6413 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6414 | if (name) |
6415 | goto cpy_name; | |
089dd79d | 6416 | |
32c5fb7e | 6417 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6418 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6419 | name = "[heap]"; |
6420 | goto cpy_name; | |
32c5fb7e ON |
6421 | } |
6422 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6423 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6424 | name = "[stack]"; |
6425 | goto cpy_name; | |
089dd79d PZ |
6426 | } |
6427 | ||
c7e548b4 ON |
6428 | name = "//anon"; |
6429 | goto cpy_name; | |
0a4a9391 PZ |
6430 | } |
6431 | ||
c7e548b4 ON |
6432 | cpy_name: |
6433 | strlcpy(tmp, name, sizeof(tmp)); | |
6434 | name = tmp; | |
0a4a9391 | 6435 | got_name: |
2c42cfbf PZ |
6436 | /* |
6437 | * Since our buffer works in 8 byte units we need to align our string | |
6438 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6439 | * zero'd out to avoid leaking random bits to userspace. | |
6440 | */ | |
6441 | size = strlen(name)+1; | |
6442 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6443 | name[size++] = '\0'; | |
0a4a9391 PZ |
6444 | |
6445 | mmap_event->file_name = name; | |
6446 | mmap_event->file_size = size; | |
13d7a241 SE |
6447 | mmap_event->maj = maj; |
6448 | mmap_event->min = min; | |
6449 | mmap_event->ino = ino; | |
6450 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6451 | mmap_event->prot = prot; |
6452 | mmap_event->flags = flags; | |
0a4a9391 | 6453 | |
2fe85427 SE |
6454 | if (!(vma->vm_flags & VM_EXEC)) |
6455 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6456 | ||
cdd6c482 | 6457 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6458 | |
67516844 | 6459 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6460 | mmap_event, |
6461 | NULL); | |
665c2142 | 6462 | |
0a4a9391 PZ |
6463 | kfree(buf); |
6464 | } | |
6465 | ||
375637bc AS |
6466 | /* |
6467 | * Whether this @filter depends on a dynamic object which is not loaded | |
6468 | * yet or its load addresses are not known. | |
6469 | */ | |
6470 | static bool perf_addr_filter_needs_mmap(struct perf_addr_filter *filter) | |
6471 | { | |
6472 | return filter->filter && filter->inode; | |
6473 | } | |
6474 | ||
6475 | /* | |
6476 | * Check whether inode and address range match filter criteria. | |
6477 | */ | |
6478 | static bool perf_addr_filter_match(struct perf_addr_filter *filter, | |
6479 | struct file *file, unsigned long offset, | |
6480 | unsigned long size) | |
6481 | { | |
6482 | if (filter->inode != file->f_inode) | |
6483 | return false; | |
6484 | ||
6485 | if (filter->offset > offset + size) | |
6486 | return false; | |
6487 | ||
6488 | if (filter->offset + filter->size < offset) | |
6489 | return false; | |
6490 | ||
6491 | return true; | |
6492 | } | |
6493 | ||
6494 | static void __perf_addr_filters_adjust(struct perf_event *event, void *data) | |
6495 | { | |
6496 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
6497 | struct vm_area_struct *vma = data; | |
6498 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags; | |
6499 | struct file *file = vma->vm_file; | |
6500 | struct perf_addr_filter *filter; | |
6501 | unsigned int restart = 0, count = 0; | |
6502 | ||
6503 | if (!has_addr_filter(event)) | |
6504 | return; | |
6505 | ||
6506 | if (!file) | |
6507 | return; | |
6508 | ||
6509 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
6510 | list_for_each_entry(filter, &ifh->list, entry) { | |
6511 | if (perf_addr_filter_match(filter, file, off, | |
6512 | vma->vm_end - vma->vm_start)) { | |
6513 | event->addr_filters_offs[count] = vma->vm_start; | |
6514 | restart++; | |
6515 | } | |
6516 | ||
6517 | count++; | |
6518 | } | |
6519 | ||
6520 | if (restart) | |
6521 | event->addr_filters_gen++; | |
6522 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
6523 | ||
6524 | if (restart) | |
6525 | perf_event_restart(event); | |
6526 | } | |
6527 | ||
6528 | /* | |
6529 | * Adjust all task's events' filters to the new vma | |
6530 | */ | |
6531 | static void perf_addr_filters_adjust(struct vm_area_struct *vma) | |
6532 | { | |
6533 | struct perf_event_context *ctx; | |
6534 | int ctxn; | |
6535 | ||
6536 | rcu_read_lock(); | |
6537 | for_each_task_context_nr(ctxn) { | |
6538 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
6539 | if (!ctx) | |
6540 | continue; | |
6541 | ||
6542 | perf_event_aux_ctx(ctx, __perf_addr_filters_adjust, vma, true); | |
6543 | } | |
6544 | rcu_read_unlock(); | |
6545 | } | |
6546 | ||
3af9e859 | 6547 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6548 | { |
9ee318a7 PZ |
6549 | struct perf_mmap_event mmap_event; |
6550 | ||
cdd6c482 | 6551 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6552 | return; |
6553 | ||
6554 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6555 | .vma = vma, |
573402db PZ |
6556 | /* .file_name */ |
6557 | /* .file_size */ | |
cdd6c482 | 6558 | .event_id = { |
573402db | 6559 | .header = { |
cdd6c482 | 6560 | .type = PERF_RECORD_MMAP, |
39447b38 | 6561 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6562 | /* .size */ |
6563 | }, | |
6564 | /* .pid */ | |
6565 | /* .tid */ | |
089dd79d PZ |
6566 | .start = vma->vm_start, |
6567 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6568 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6569 | }, |
13d7a241 SE |
6570 | /* .maj (attr_mmap2 only) */ |
6571 | /* .min (attr_mmap2 only) */ | |
6572 | /* .ino (attr_mmap2 only) */ | |
6573 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6574 | /* .prot (attr_mmap2 only) */ |
6575 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6576 | }; |
6577 | ||
375637bc | 6578 | perf_addr_filters_adjust(vma); |
cdd6c482 | 6579 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6580 | } |
6581 | ||
68db7e98 AS |
6582 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6583 | unsigned long size, u64 flags) | |
6584 | { | |
6585 | struct perf_output_handle handle; | |
6586 | struct perf_sample_data sample; | |
6587 | struct perf_aux_event { | |
6588 | struct perf_event_header header; | |
6589 | u64 offset; | |
6590 | u64 size; | |
6591 | u64 flags; | |
6592 | } rec = { | |
6593 | .header = { | |
6594 | .type = PERF_RECORD_AUX, | |
6595 | .misc = 0, | |
6596 | .size = sizeof(rec), | |
6597 | }, | |
6598 | .offset = head, | |
6599 | .size = size, | |
6600 | .flags = flags, | |
6601 | }; | |
6602 | int ret; | |
6603 | ||
6604 | perf_event_header__init_id(&rec.header, &sample, event); | |
6605 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6606 | ||
6607 | if (ret) | |
6608 | return; | |
6609 | ||
6610 | perf_output_put(&handle, rec); | |
6611 | perf_event__output_id_sample(event, &handle, &sample); | |
6612 | ||
6613 | perf_output_end(&handle); | |
6614 | } | |
6615 | ||
f38b0dbb KL |
6616 | /* |
6617 | * Lost/dropped samples logging | |
6618 | */ | |
6619 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6620 | { | |
6621 | struct perf_output_handle handle; | |
6622 | struct perf_sample_data sample; | |
6623 | int ret; | |
6624 | ||
6625 | struct { | |
6626 | struct perf_event_header header; | |
6627 | u64 lost; | |
6628 | } lost_samples_event = { | |
6629 | .header = { | |
6630 | .type = PERF_RECORD_LOST_SAMPLES, | |
6631 | .misc = 0, | |
6632 | .size = sizeof(lost_samples_event), | |
6633 | }, | |
6634 | .lost = lost, | |
6635 | }; | |
6636 | ||
6637 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6638 | ||
6639 | ret = perf_output_begin(&handle, event, | |
6640 | lost_samples_event.header.size); | |
6641 | if (ret) | |
6642 | return; | |
6643 | ||
6644 | perf_output_put(&handle, lost_samples_event); | |
6645 | perf_event__output_id_sample(event, &handle, &sample); | |
6646 | perf_output_end(&handle); | |
6647 | } | |
6648 | ||
45ac1403 AH |
6649 | /* |
6650 | * context_switch tracking | |
6651 | */ | |
6652 | ||
6653 | struct perf_switch_event { | |
6654 | struct task_struct *task; | |
6655 | struct task_struct *next_prev; | |
6656 | ||
6657 | struct { | |
6658 | struct perf_event_header header; | |
6659 | u32 next_prev_pid; | |
6660 | u32 next_prev_tid; | |
6661 | } event_id; | |
6662 | }; | |
6663 | ||
6664 | static int perf_event_switch_match(struct perf_event *event) | |
6665 | { | |
6666 | return event->attr.context_switch; | |
6667 | } | |
6668 | ||
6669 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6670 | { | |
6671 | struct perf_switch_event *se = data; | |
6672 | struct perf_output_handle handle; | |
6673 | struct perf_sample_data sample; | |
6674 | int ret; | |
6675 | ||
6676 | if (!perf_event_switch_match(event)) | |
6677 | return; | |
6678 | ||
6679 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6680 | if (event->ctx->task) { | |
6681 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6682 | se->event_id.header.size = sizeof(se->event_id.header); | |
6683 | } else { | |
6684 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6685 | se->event_id.header.size = sizeof(se->event_id); | |
6686 | se->event_id.next_prev_pid = | |
6687 | perf_event_pid(event, se->next_prev); | |
6688 | se->event_id.next_prev_tid = | |
6689 | perf_event_tid(event, se->next_prev); | |
6690 | } | |
6691 | ||
6692 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6693 | ||
6694 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6695 | if (ret) | |
6696 | return; | |
6697 | ||
6698 | if (event->ctx->task) | |
6699 | perf_output_put(&handle, se->event_id.header); | |
6700 | else | |
6701 | perf_output_put(&handle, se->event_id); | |
6702 | ||
6703 | perf_event__output_id_sample(event, &handle, &sample); | |
6704 | ||
6705 | perf_output_end(&handle); | |
6706 | } | |
6707 | ||
6708 | static void perf_event_switch(struct task_struct *task, | |
6709 | struct task_struct *next_prev, bool sched_in) | |
6710 | { | |
6711 | struct perf_switch_event switch_event; | |
6712 | ||
6713 | /* N.B. caller checks nr_switch_events != 0 */ | |
6714 | ||
6715 | switch_event = (struct perf_switch_event){ | |
6716 | .task = task, | |
6717 | .next_prev = next_prev, | |
6718 | .event_id = { | |
6719 | .header = { | |
6720 | /* .type */ | |
6721 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6722 | /* .size */ | |
6723 | }, | |
6724 | /* .next_prev_pid */ | |
6725 | /* .next_prev_tid */ | |
6726 | }, | |
6727 | }; | |
6728 | ||
6729 | perf_event_aux(perf_event_switch_output, | |
6730 | &switch_event, | |
6731 | NULL); | |
6732 | } | |
6733 | ||
a78ac325 PZ |
6734 | /* |
6735 | * IRQ throttle logging | |
6736 | */ | |
6737 | ||
cdd6c482 | 6738 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6739 | { |
6740 | struct perf_output_handle handle; | |
c980d109 | 6741 | struct perf_sample_data sample; |
a78ac325 PZ |
6742 | int ret; |
6743 | ||
6744 | struct { | |
6745 | struct perf_event_header header; | |
6746 | u64 time; | |
cca3f454 | 6747 | u64 id; |
7f453c24 | 6748 | u64 stream_id; |
a78ac325 PZ |
6749 | } throttle_event = { |
6750 | .header = { | |
cdd6c482 | 6751 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6752 | .misc = 0, |
6753 | .size = sizeof(throttle_event), | |
6754 | }, | |
34f43927 | 6755 | .time = perf_event_clock(event), |
cdd6c482 IM |
6756 | .id = primary_event_id(event), |
6757 | .stream_id = event->id, | |
a78ac325 PZ |
6758 | }; |
6759 | ||
966ee4d6 | 6760 | if (enable) |
cdd6c482 | 6761 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6762 | |
c980d109 ACM |
6763 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6764 | ||
6765 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6766 | throttle_event.header.size); |
a78ac325 PZ |
6767 | if (ret) |
6768 | return; | |
6769 | ||
6770 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6771 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6772 | perf_output_end(&handle); |
6773 | } | |
6774 | ||
ec0d7729 AS |
6775 | static void perf_log_itrace_start(struct perf_event *event) |
6776 | { | |
6777 | struct perf_output_handle handle; | |
6778 | struct perf_sample_data sample; | |
6779 | struct perf_aux_event { | |
6780 | struct perf_event_header header; | |
6781 | u32 pid; | |
6782 | u32 tid; | |
6783 | } rec; | |
6784 | int ret; | |
6785 | ||
6786 | if (event->parent) | |
6787 | event = event->parent; | |
6788 | ||
6789 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6790 | event->hw.itrace_started) | |
6791 | return; | |
6792 | ||
ec0d7729 AS |
6793 | rec.header.type = PERF_RECORD_ITRACE_START; |
6794 | rec.header.misc = 0; | |
6795 | rec.header.size = sizeof(rec); | |
6796 | rec.pid = perf_event_pid(event, current); | |
6797 | rec.tid = perf_event_tid(event, current); | |
6798 | ||
6799 | perf_event_header__init_id(&rec.header, &sample, event); | |
6800 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6801 | ||
6802 | if (ret) | |
6803 | return; | |
6804 | ||
6805 | perf_output_put(&handle, rec); | |
6806 | perf_event__output_id_sample(event, &handle, &sample); | |
6807 | ||
6808 | perf_output_end(&handle); | |
6809 | } | |
6810 | ||
f6c7d5fe | 6811 | /* |
cdd6c482 | 6812 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6813 | */ |
6814 | ||
a8b0ca17 | 6815 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6816 | int throttle, struct perf_sample_data *data, |
6817 | struct pt_regs *regs) | |
f6c7d5fe | 6818 | { |
cdd6c482 IM |
6819 | int events = atomic_read(&event->event_limit); |
6820 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6821 | u64 seq; |
79f14641 PZ |
6822 | int ret = 0; |
6823 | ||
96398826 PZ |
6824 | /* |
6825 | * Non-sampling counters might still use the PMI to fold short | |
6826 | * hardware counters, ignore those. | |
6827 | */ | |
6828 | if (unlikely(!is_sampling_event(event))) | |
6829 | return 0; | |
6830 | ||
e050e3f0 SE |
6831 | seq = __this_cpu_read(perf_throttled_seq); |
6832 | if (seq != hwc->interrupts_seq) { | |
6833 | hwc->interrupts_seq = seq; | |
6834 | hwc->interrupts = 1; | |
6835 | } else { | |
6836 | hwc->interrupts++; | |
6837 | if (unlikely(throttle | |
6838 | && hwc->interrupts >= max_samples_per_tick)) { | |
6839 | __this_cpu_inc(perf_throttled_count); | |
555e0c1e | 6840 | tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
163ec435 PZ |
6841 | hwc->interrupts = MAX_INTERRUPTS; |
6842 | perf_log_throttle(event, 0); | |
a78ac325 PZ |
6843 | ret = 1; |
6844 | } | |
e050e3f0 | 6845 | } |
60db5e09 | 6846 | |
cdd6c482 | 6847 | if (event->attr.freq) { |
def0a9b2 | 6848 | u64 now = perf_clock(); |
abd50713 | 6849 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6850 | |
abd50713 | 6851 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6852 | |
abd50713 | 6853 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6854 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6855 | } |
6856 | ||
2023b359 PZ |
6857 | /* |
6858 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6859 | * events |
2023b359 PZ |
6860 | */ |
6861 | ||
cdd6c482 IM |
6862 | event->pending_kill = POLL_IN; |
6863 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6864 | ret = 1; |
cdd6c482 | 6865 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6866 | event->pending_disable = 1; |
6867 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6868 | } |
6869 | ||
1879445d | 6870 | event->overflow_handler(event, data, regs); |
453f19ee | 6871 | |
fed66e2c | 6872 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6873 | event->pending_wakeup = 1; |
6874 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6875 | } |
6876 | ||
79f14641 | 6877 | return ret; |
f6c7d5fe PZ |
6878 | } |
6879 | ||
a8b0ca17 | 6880 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6881 | struct perf_sample_data *data, |
6882 | struct pt_regs *regs) | |
850bc73f | 6883 | { |
a8b0ca17 | 6884 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6885 | } |
6886 | ||
15dbf27c | 6887 | /* |
cdd6c482 | 6888 | * Generic software event infrastructure |
15dbf27c PZ |
6889 | */ |
6890 | ||
b28ab83c PZ |
6891 | struct swevent_htable { |
6892 | struct swevent_hlist *swevent_hlist; | |
6893 | struct mutex hlist_mutex; | |
6894 | int hlist_refcount; | |
6895 | ||
6896 | /* Recursion avoidance in each contexts */ | |
6897 | int recursion[PERF_NR_CONTEXTS]; | |
6898 | }; | |
6899 | ||
6900 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6901 | ||
7b4b6658 | 6902 | /* |
cdd6c482 IM |
6903 | * We directly increment event->count and keep a second value in |
6904 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6905 | * is kept in the range [-sample_period, 0] so that we can use the |
6906 | * sign as trigger. | |
6907 | */ | |
6908 | ||
ab573844 | 6909 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6910 | { |
cdd6c482 | 6911 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6912 | u64 period = hwc->last_period; |
6913 | u64 nr, offset; | |
6914 | s64 old, val; | |
6915 | ||
6916 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6917 | |
6918 | again: | |
e7850595 | 6919 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6920 | if (val < 0) |
6921 | return 0; | |
15dbf27c | 6922 | |
7b4b6658 PZ |
6923 | nr = div64_u64(period + val, period); |
6924 | offset = nr * period; | |
6925 | val -= offset; | |
e7850595 | 6926 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6927 | goto again; |
15dbf27c | 6928 | |
7b4b6658 | 6929 | return nr; |
15dbf27c PZ |
6930 | } |
6931 | ||
0cff784a | 6932 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6933 | struct perf_sample_data *data, |
5622f295 | 6934 | struct pt_regs *regs) |
15dbf27c | 6935 | { |
cdd6c482 | 6936 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6937 | int throttle = 0; |
15dbf27c | 6938 | |
0cff784a PZ |
6939 | if (!overflow) |
6940 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6941 | |
7b4b6658 PZ |
6942 | if (hwc->interrupts == MAX_INTERRUPTS) |
6943 | return; | |
15dbf27c | 6944 | |
7b4b6658 | 6945 | for (; overflow; overflow--) { |
a8b0ca17 | 6946 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6947 | data, regs)) { |
7b4b6658 PZ |
6948 | /* |
6949 | * We inhibit the overflow from happening when | |
6950 | * hwc->interrupts == MAX_INTERRUPTS. | |
6951 | */ | |
6952 | break; | |
6953 | } | |
cf450a73 | 6954 | throttle = 1; |
7b4b6658 | 6955 | } |
15dbf27c PZ |
6956 | } |
6957 | ||
a4eaf7f1 | 6958 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6959 | struct perf_sample_data *data, |
5622f295 | 6960 | struct pt_regs *regs) |
7b4b6658 | 6961 | { |
cdd6c482 | 6962 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6963 | |
e7850595 | 6964 | local64_add(nr, &event->count); |
d6d020e9 | 6965 | |
0cff784a PZ |
6966 | if (!regs) |
6967 | return; | |
6968 | ||
6c7e550f | 6969 | if (!is_sampling_event(event)) |
7b4b6658 | 6970 | return; |
d6d020e9 | 6971 | |
5d81e5cf AV |
6972 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6973 | data->period = nr; | |
6974 | return perf_swevent_overflow(event, 1, data, regs); | |
6975 | } else | |
6976 | data->period = event->hw.last_period; | |
6977 | ||
0cff784a | 6978 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6979 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6980 | |
e7850595 | 6981 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6982 | return; |
df1a132b | 6983 | |
a8b0ca17 | 6984 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6985 | } |
6986 | ||
f5ffe02e FW |
6987 | static int perf_exclude_event(struct perf_event *event, |
6988 | struct pt_regs *regs) | |
6989 | { | |
a4eaf7f1 | 6990 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6991 | return 1; |
a4eaf7f1 | 6992 | |
f5ffe02e FW |
6993 | if (regs) { |
6994 | if (event->attr.exclude_user && user_mode(regs)) | |
6995 | return 1; | |
6996 | ||
6997 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6998 | return 1; | |
6999 | } | |
7000 | ||
7001 | return 0; | |
7002 | } | |
7003 | ||
cdd6c482 | 7004 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 7005 | enum perf_type_id type, |
6fb2915d LZ |
7006 | u32 event_id, |
7007 | struct perf_sample_data *data, | |
7008 | struct pt_regs *regs) | |
15dbf27c | 7009 | { |
cdd6c482 | 7010 | if (event->attr.type != type) |
a21ca2ca | 7011 | return 0; |
f5ffe02e | 7012 | |
cdd6c482 | 7013 | if (event->attr.config != event_id) |
15dbf27c PZ |
7014 | return 0; |
7015 | ||
f5ffe02e FW |
7016 | if (perf_exclude_event(event, regs)) |
7017 | return 0; | |
15dbf27c PZ |
7018 | |
7019 | return 1; | |
7020 | } | |
7021 | ||
76e1d904 FW |
7022 | static inline u64 swevent_hash(u64 type, u32 event_id) |
7023 | { | |
7024 | u64 val = event_id | (type << 32); | |
7025 | ||
7026 | return hash_64(val, SWEVENT_HLIST_BITS); | |
7027 | } | |
7028 | ||
49f135ed FW |
7029 | static inline struct hlist_head * |
7030 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 7031 | { |
49f135ed FW |
7032 | u64 hash = swevent_hash(type, event_id); |
7033 | ||
7034 | return &hlist->heads[hash]; | |
7035 | } | |
76e1d904 | 7036 | |
49f135ed FW |
7037 | /* For the read side: events when they trigger */ |
7038 | static inline struct hlist_head * | |
b28ab83c | 7039 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
7040 | { |
7041 | struct swevent_hlist *hlist; | |
76e1d904 | 7042 | |
b28ab83c | 7043 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
7044 | if (!hlist) |
7045 | return NULL; | |
7046 | ||
49f135ed FW |
7047 | return __find_swevent_head(hlist, type, event_id); |
7048 | } | |
7049 | ||
7050 | /* For the event head insertion and removal in the hlist */ | |
7051 | static inline struct hlist_head * | |
b28ab83c | 7052 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
7053 | { |
7054 | struct swevent_hlist *hlist; | |
7055 | u32 event_id = event->attr.config; | |
7056 | u64 type = event->attr.type; | |
7057 | ||
7058 | /* | |
7059 | * Event scheduling is always serialized against hlist allocation | |
7060 | * and release. Which makes the protected version suitable here. | |
7061 | * The context lock guarantees that. | |
7062 | */ | |
b28ab83c | 7063 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
7064 | lockdep_is_held(&event->ctx->lock)); |
7065 | if (!hlist) | |
7066 | return NULL; | |
7067 | ||
7068 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
7069 | } |
7070 | ||
7071 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 7072 | u64 nr, |
76e1d904 FW |
7073 | struct perf_sample_data *data, |
7074 | struct pt_regs *regs) | |
15dbf27c | 7075 | { |
4a32fea9 | 7076 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 7077 | struct perf_event *event; |
76e1d904 | 7078 | struct hlist_head *head; |
15dbf27c | 7079 | |
76e1d904 | 7080 | rcu_read_lock(); |
b28ab83c | 7081 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
7082 | if (!head) |
7083 | goto end; | |
7084 | ||
b67bfe0d | 7085 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 7086 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 7087 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 7088 | } |
76e1d904 FW |
7089 | end: |
7090 | rcu_read_unlock(); | |
15dbf27c PZ |
7091 | } |
7092 | ||
86038c5e PZI |
7093 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
7094 | ||
4ed7c92d | 7095 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 7096 | { |
4a32fea9 | 7097 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 7098 | |
b28ab83c | 7099 | return get_recursion_context(swhash->recursion); |
96f6d444 | 7100 | } |
645e8cc0 | 7101 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 7102 | |
fa9f90be | 7103 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 7104 | { |
4a32fea9 | 7105 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 7106 | |
b28ab83c | 7107 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 7108 | } |
15dbf27c | 7109 | |
86038c5e | 7110 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 7111 | { |
a4234bfc | 7112 | struct perf_sample_data data; |
4ed7c92d | 7113 | |
86038c5e | 7114 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 7115 | return; |
a4234bfc | 7116 | |
fd0d000b | 7117 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 7118 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
7119 | } |
7120 | ||
7121 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
7122 | { | |
7123 | int rctx; | |
7124 | ||
7125 | preempt_disable_notrace(); | |
7126 | rctx = perf_swevent_get_recursion_context(); | |
7127 | if (unlikely(rctx < 0)) | |
7128 | goto fail; | |
7129 | ||
7130 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
7131 | |
7132 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 7133 | fail: |
1c024eca | 7134 | preempt_enable_notrace(); |
b8e83514 PZ |
7135 | } |
7136 | ||
cdd6c482 | 7137 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 7138 | { |
15dbf27c PZ |
7139 | } |
7140 | ||
a4eaf7f1 | 7141 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 7142 | { |
4a32fea9 | 7143 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 7144 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
7145 | struct hlist_head *head; |
7146 | ||
6c7e550f | 7147 | if (is_sampling_event(event)) { |
7b4b6658 | 7148 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 7149 | perf_swevent_set_period(event); |
7b4b6658 | 7150 | } |
76e1d904 | 7151 | |
a4eaf7f1 PZ |
7152 | hwc->state = !(flags & PERF_EF_START); |
7153 | ||
b28ab83c | 7154 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 7155 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
7156 | return -EINVAL; |
7157 | ||
7158 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 7159 | perf_event_update_userpage(event); |
76e1d904 | 7160 | |
15dbf27c PZ |
7161 | return 0; |
7162 | } | |
7163 | ||
a4eaf7f1 | 7164 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 7165 | { |
76e1d904 | 7166 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
7167 | } |
7168 | ||
a4eaf7f1 | 7169 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 7170 | { |
a4eaf7f1 | 7171 | event->hw.state = 0; |
d6d020e9 | 7172 | } |
aa9c4c0f | 7173 | |
a4eaf7f1 | 7174 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 7175 | { |
a4eaf7f1 | 7176 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
7177 | } |
7178 | ||
49f135ed FW |
7179 | /* Deref the hlist from the update side */ |
7180 | static inline struct swevent_hlist * | |
b28ab83c | 7181 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 7182 | { |
b28ab83c PZ |
7183 | return rcu_dereference_protected(swhash->swevent_hlist, |
7184 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
7185 | } |
7186 | ||
b28ab83c | 7187 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 7188 | { |
b28ab83c | 7189 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 7190 | |
49f135ed | 7191 | if (!hlist) |
76e1d904 FW |
7192 | return; |
7193 | ||
70691d4a | 7194 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 7195 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
7196 | } |
7197 | ||
3b364d7b | 7198 | static void swevent_hlist_put_cpu(int cpu) |
76e1d904 | 7199 | { |
b28ab83c | 7200 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 7201 | |
b28ab83c | 7202 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 7203 | |
b28ab83c PZ |
7204 | if (!--swhash->hlist_refcount) |
7205 | swevent_hlist_release(swhash); | |
76e1d904 | 7206 | |
b28ab83c | 7207 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
7208 | } |
7209 | ||
3b364d7b | 7210 | static void swevent_hlist_put(void) |
76e1d904 FW |
7211 | { |
7212 | int cpu; | |
7213 | ||
76e1d904 | 7214 | for_each_possible_cpu(cpu) |
3b364d7b | 7215 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
7216 | } |
7217 | ||
3b364d7b | 7218 | static int swevent_hlist_get_cpu(int cpu) |
76e1d904 | 7219 | { |
b28ab83c | 7220 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
7221 | int err = 0; |
7222 | ||
b28ab83c | 7223 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 7224 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
7225 | struct swevent_hlist *hlist; |
7226 | ||
7227 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
7228 | if (!hlist) { | |
7229 | err = -ENOMEM; | |
7230 | goto exit; | |
7231 | } | |
b28ab83c | 7232 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 7233 | } |
b28ab83c | 7234 | swhash->hlist_refcount++; |
9ed6060d | 7235 | exit: |
b28ab83c | 7236 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
7237 | |
7238 | return err; | |
7239 | } | |
7240 | ||
3b364d7b | 7241 | static int swevent_hlist_get(void) |
76e1d904 | 7242 | { |
3b364d7b | 7243 | int err, cpu, failed_cpu; |
76e1d904 | 7244 | |
76e1d904 FW |
7245 | get_online_cpus(); |
7246 | for_each_possible_cpu(cpu) { | |
3b364d7b | 7247 | err = swevent_hlist_get_cpu(cpu); |
76e1d904 FW |
7248 | if (err) { |
7249 | failed_cpu = cpu; | |
7250 | goto fail; | |
7251 | } | |
7252 | } | |
7253 | put_online_cpus(); | |
7254 | ||
7255 | return 0; | |
9ed6060d | 7256 | fail: |
76e1d904 FW |
7257 | for_each_possible_cpu(cpu) { |
7258 | if (cpu == failed_cpu) | |
7259 | break; | |
3b364d7b | 7260 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
7261 | } |
7262 | ||
7263 | put_online_cpus(); | |
7264 | return err; | |
7265 | } | |
7266 | ||
c5905afb | 7267 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 7268 | |
b0a873eb PZ |
7269 | static void sw_perf_event_destroy(struct perf_event *event) |
7270 | { | |
7271 | u64 event_id = event->attr.config; | |
95476b64 | 7272 | |
b0a873eb PZ |
7273 | WARN_ON(event->parent); |
7274 | ||
c5905afb | 7275 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
3b364d7b | 7276 | swevent_hlist_put(); |
b0a873eb PZ |
7277 | } |
7278 | ||
7279 | static int perf_swevent_init(struct perf_event *event) | |
7280 | { | |
8176cced | 7281 | u64 event_id = event->attr.config; |
b0a873eb PZ |
7282 | |
7283 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7284 | return -ENOENT; | |
7285 | ||
2481c5fa SE |
7286 | /* |
7287 | * no branch sampling for software events | |
7288 | */ | |
7289 | if (has_branch_stack(event)) | |
7290 | return -EOPNOTSUPP; | |
7291 | ||
b0a873eb PZ |
7292 | switch (event_id) { |
7293 | case PERF_COUNT_SW_CPU_CLOCK: | |
7294 | case PERF_COUNT_SW_TASK_CLOCK: | |
7295 | return -ENOENT; | |
7296 | ||
7297 | default: | |
7298 | break; | |
7299 | } | |
7300 | ||
ce677831 | 7301 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
7302 | return -ENOENT; |
7303 | ||
7304 | if (!event->parent) { | |
7305 | int err; | |
7306 | ||
3b364d7b | 7307 | err = swevent_hlist_get(); |
b0a873eb PZ |
7308 | if (err) |
7309 | return err; | |
7310 | ||
c5905afb | 7311 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
7312 | event->destroy = sw_perf_event_destroy; |
7313 | } | |
7314 | ||
7315 | return 0; | |
7316 | } | |
7317 | ||
7318 | static struct pmu perf_swevent = { | |
89a1e187 | 7319 | .task_ctx_nr = perf_sw_context, |
95476b64 | 7320 | |
34f43927 PZ |
7321 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7322 | ||
b0a873eb | 7323 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
7324 | .add = perf_swevent_add, |
7325 | .del = perf_swevent_del, | |
7326 | .start = perf_swevent_start, | |
7327 | .stop = perf_swevent_stop, | |
1c024eca | 7328 | .read = perf_swevent_read, |
1c024eca PZ |
7329 | }; |
7330 | ||
b0a873eb PZ |
7331 | #ifdef CONFIG_EVENT_TRACING |
7332 | ||
1c024eca PZ |
7333 | static int perf_tp_filter_match(struct perf_event *event, |
7334 | struct perf_sample_data *data) | |
7335 | { | |
7336 | void *record = data->raw->data; | |
7337 | ||
b71b437e PZ |
7338 | /* only top level events have filters set */ |
7339 | if (event->parent) | |
7340 | event = event->parent; | |
7341 | ||
1c024eca PZ |
7342 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
7343 | return 1; | |
7344 | return 0; | |
7345 | } | |
7346 | ||
7347 | static int perf_tp_event_match(struct perf_event *event, | |
7348 | struct perf_sample_data *data, | |
7349 | struct pt_regs *regs) | |
7350 | { | |
a0f7d0f7 FW |
7351 | if (event->hw.state & PERF_HES_STOPPED) |
7352 | return 0; | |
580d607c PZ |
7353 | /* |
7354 | * All tracepoints are from kernel-space. | |
7355 | */ | |
7356 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
7357 | return 0; |
7358 | ||
7359 | if (!perf_tp_filter_match(event, data)) | |
7360 | return 0; | |
7361 | ||
7362 | return 1; | |
7363 | } | |
7364 | ||
7365 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
7366 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
7367 | struct task_struct *task) | |
95476b64 FW |
7368 | { |
7369 | struct perf_sample_data data; | |
1c024eca | 7370 | struct perf_event *event; |
1c024eca | 7371 | |
95476b64 FW |
7372 | struct perf_raw_record raw = { |
7373 | .size = entry_size, | |
7374 | .data = record, | |
7375 | }; | |
7376 | ||
fd0d000b | 7377 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
7378 | data.raw = &raw; |
7379 | ||
b67bfe0d | 7380 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 7381 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 7382 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 7383 | } |
ecc55f84 | 7384 | |
e6dab5ff AV |
7385 | /* |
7386 | * If we got specified a target task, also iterate its context and | |
7387 | * deliver this event there too. | |
7388 | */ | |
7389 | if (task && task != current) { | |
7390 | struct perf_event_context *ctx; | |
7391 | struct trace_entry *entry = record; | |
7392 | ||
7393 | rcu_read_lock(); | |
7394 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
7395 | if (!ctx) | |
7396 | goto unlock; | |
7397 | ||
7398 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
7399 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7400 | continue; | |
7401 | if (event->attr.config != entry->type) | |
7402 | continue; | |
7403 | if (perf_tp_event_match(event, &data, regs)) | |
7404 | perf_swevent_event(event, count, &data, regs); | |
7405 | } | |
7406 | unlock: | |
7407 | rcu_read_unlock(); | |
7408 | } | |
7409 | ||
ecc55f84 | 7410 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
7411 | } |
7412 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
7413 | ||
cdd6c482 | 7414 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 7415 | { |
1c024eca | 7416 | perf_trace_destroy(event); |
e077df4f PZ |
7417 | } |
7418 | ||
b0a873eb | 7419 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 7420 | { |
76e1d904 FW |
7421 | int err; |
7422 | ||
b0a873eb PZ |
7423 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
7424 | return -ENOENT; | |
7425 | ||
2481c5fa SE |
7426 | /* |
7427 | * no branch sampling for tracepoint events | |
7428 | */ | |
7429 | if (has_branch_stack(event)) | |
7430 | return -EOPNOTSUPP; | |
7431 | ||
1c024eca PZ |
7432 | err = perf_trace_init(event); |
7433 | if (err) | |
b0a873eb | 7434 | return err; |
e077df4f | 7435 | |
cdd6c482 | 7436 | event->destroy = tp_perf_event_destroy; |
e077df4f | 7437 | |
b0a873eb PZ |
7438 | return 0; |
7439 | } | |
7440 | ||
7441 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
7442 | .task_ctx_nr = perf_sw_context, |
7443 | ||
b0a873eb | 7444 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
7445 | .add = perf_trace_add, |
7446 | .del = perf_trace_del, | |
7447 | .start = perf_swevent_start, | |
7448 | .stop = perf_swevent_stop, | |
b0a873eb | 7449 | .read = perf_swevent_read, |
b0a873eb PZ |
7450 | }; |
7451 | ||
7452 | static inline void perf_tp_register(void) | |
7453 | { | |
2e80a82a | 7454 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 7455 | } |
6fb2915d | 7456 | |
6fb2915d LZ |
7457 | static void perf_event_free_filter(struct perf_event *event) |
7458 | { | |
7459 | ftrace_profile_free_filter(event); | |
7460 | } | |
7461 | ||
2541517c AS |
7462 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7463 | { | |
7464 | struct bpf_prog *prog; | |
7465 | ||
7466 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7467 | return -EINVAL; | |
7468 | ||
7469 | if (event->tp_event->prog) | |
7470 | return -EEXIST; | |
7471 | ||
04a22fae WN |
7472 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7473 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7474 | return -EINVAL; |
7475 | ||
7476 | prog = bpf_prog_get(prog_fd); | |
7477 | if (IS_ERR(prog)) | |
7478 | return PTR_ERR(prog); | |
7479 | ||
6c373ca8 | 7480 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7481 | /* valid fd, but invalid bpf program type */ |
7482 | bpf_prog_put(prog); | |
7483 | return -EINVAL; | |
7484 | } | |
7485 | ||
7486 | event->tp_event->prog = prog; | |
7487 | ||
7488 | return 0; | |
7489 | } | |
7490 | ||
7491 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7492 | { | |
7493 | struct bpf_prog *prog; | |
7494 | ||
7495 | if (!event->tp_event) | |
7496 | return; | |
7497 | ||
7498 | prog = event->tp_event->prog; | |
7499 | if (prog) { | |
7500 | event->tp_event->prog = NULL; | |
7501 | bpf_prog_put(prog); | |
7502 | } | |
7503 | } | |
7504 | ||
e077df4f | 7505 | #else |
6fb2915d | 7506 | |
b0a873eb | 7507 | static inline void perf_tp_register(void) |
e077df4f | 7508 | { |
e077df4f | 7509 | } |
6fb2915d | 7510 | |
6fb2915d LZ |
7511 | static void perf_event_free_filter(struct perf_event *event) |
7512 | { | |
7513 | } | |
7514 | ||
2541517c AS |
7515 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7516 | { | |
7517 | return -ENOENT; | |
7518 | } | |
7519 | ||
7520 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7521 | { | |
7522 | } | |
07b139c8 | 7523 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7524 | |
24f1e32c | 7525 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7526 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7527 | { |
f5ffe02e FW |
7528 | struct perf_sample_data sample; |
7529 | struct pt_regs *regs = data; | |
7530 | ||
fd0d000b | 7531 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7532 | |
a4eaf7f1 | 7533 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7534 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7535 | } |
7536 | #endif | |
7537 | ||
375637bc AS |
7538 | /* |
7539 | * Allocate a new address filter | |
7540 | */ | |
7541 | static struct perf_addr_filter * | |
7542 | perf_addr_filter_new(struct perf_event *event, struct list_head *filters) | |
7543 | { | |
7544 | int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu); | |
7545 | struct perf_addr_filter *filter; | |
7546 | ||
7547 | filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node); | |
7548 | if (!filter) | |
7549 | return NULL; | |
7550 | ||
7551 | INIT_LIST_HEAD(&filter->entry); | |
7552 | list_add_tail(&filter->entry, filters); | |
7553 | ||
7554 | return filter; | |
7555 | } | |
7556 | ||
7557 | static void free_filters_list(struct list_head *filters) | |
7558 | { | |
7559 | struct perf_addr_filter *filter, *iter; | |
7560 | ||
7561 | list_for_each_entry_safe(filter, iter, filters, entry) { | |
7562 | if (filter->inode) | |
7563 | iput(filter->inode); | |
7564 | list_del(&filter->entry); | |
7565 | kfree(filter); | |
7566 | } | |
7567 | } | |
7568 | ||
7569 | /* | |
7570 | * Free existing address filters and optionally install new ones | |
7571 | */ | |
7572 | static void perf_addr_filters_splice(struct perf_event *event, | |
7573 | struct list_head *head) | |
7574 | { | |
7575 | unsigned long flags; | |
7576 | LIST_HEAD(list); | |
7577 | ||
7578 | if (!has_addr_filter(event)) | |
7579 | return; | |
7580 | ||
7581 | /* don't bother with children, they don't have their own filters */ | |
7582 | if (event->parent) | |
7583 | return; | |
7584 | ||
7585 | raw_spin_lock_irqsave(&event->addr_filters.lock, flags); | |
7586 | ||
7587 | list_splice_init(&event->addr_filters.list, &list); | |
7588 | if (head) | |
7589 | list_splice(head, &event->addr_filters.list); | |
7590 | ||
7591 | raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags); | |
7592 | ||
7593 | free_filters_list(&list); | |
7594 | } | |
7595 | ||
7596 | /* | |
7597 | * Scan through mm's vmas and see if one of them matches the | |
7598 | * @filter; if so, adjust filter's address range. | |
7599 | * Called with mm::mmap_sem down for reading. | |
7600 | */ | |
7601 | static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter, | |
7602 | struct mm_struct *mm) | |
7603 | { | |
7604 | struct vm_area_struct *vma; | |
7605 | ||
7606 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
7607 | struct file *file = vma->vm_file; | |
7608 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT; | |
7609 | unsigned long vma_size = vma->vm_end - vma->vm_start; | |
7610 | ||
7611 | if (!file) | |
7612 | continue; | |
7613 | ||
7614 | if (!perf_addr_filter_match(filter, file, off, vma_size)) | |
7615 | continue; | |
7616 | ||
7617 | return vma->vm_start; | |
7618 | } | |
7619 | ||
7620 | return 0; | |
7621 | } | |
7622 | ||
7623 | /* | |
7624 | * Update event's address range filters based on the | |
7625 | * task's existing mappings, if any. | |
7626 | */ | |
7627 | static void perf_event_addr_filters_apply(struct perf_event *event) | |
7628 | { | |
7629 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
7630 | struct task_struct *task = READ_ONCE(event->ctx->task); | |
7631 | struct perf_addr_filter *filter; | |
7632 | struct mm_struct *mm = NULL; | |
7633 | unsigned int count = 0; | |
7634 | unsigned long flags; | |
7635 | ||
7636 | /* | |
7637 | * We may observe TASK_TOMBSTONE, which means that the event tear-down | |
7638 | * will stop on the parent's child_mutex that our caller is also holding | |
7639 | */ | |
7640 | if (task == TASK_TOMBSTONE) | |
7641 | return; | |
7642 | ||
7643 | mm = get_task_mm(event->ctx->task); | |
7644 | if (!mm) | |
7645 | goto restart; | |
7646 | ||
7647 | down_read(&mm->mmap_sem); | |
7648 | ||
7649 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
7650 | list_for_each_entry(filter, &ifh->list, entry) { | |
7651 | event->addr_filters_offs[count] = 0; | |
7652 | ||
7653 | if (perf_addr_filter_needs_mmap(filter)) | |
7654 | event->addr_filters_offs[count] = | |
7655 | perf_addr_filter_apply(filter, mm); | |
7656 | ||
7657 | count++; | |
7658 | } | |
7659 | ||
7660 | event->addr_filters_gen++; | |
7661 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
7662 | ||
7663 | up_read(&mm->mmap_sem); | |
7664 | ||
7665 | mmput(mm); | |
7666 | ||
7667 | restart: | |
7668 | perf_event_restart(event); | |
7669 | } | |
7670 | ||
7671 | /* | |
7672 | * Address range filtering: limiting the data to certain | |
7673 | * instruction address ranges. Filters are ioctl()ed to us from | |
7674 | * userspace as ascii strings. | |
7675 | * | |
7676 | * Filter string format: | |
7677 | * | |
7678 | * ACTION RANGE_SPEC | |
7679 | * where ACTION is one of the | |
7680 | * * "filter": limit the trace to this region | |
7681 | * * "start": start tracing from this address | |
7682 | * * "stop": stop tracing at this address/region; | |
7683 | * RANGE_SPEC is | |
7684 | * * for kernel addresses: <start address>[/<size>] | |
7685 | * * for object files: <start address>[/<size>]@</path/to/object/file> | |
7686 | * | |
7687 | * if <size> is not specified, the range is treated as a single address. | |
7688 | */ | |
7689 | enum { | |
7690 | IF_ACT_FILTER, | |
7691 | IF_ACT_START, | |
7692 | IF_ACT_STOP, | |
7693 | IF_SRC_FILE, | |
7694 | IF_SRC_KERNEL, | |
7695 | IF_SRC_FILEADDR, | |
7696 | IF_SRC_KERNELADDR, | |
7697 | }; | |
7698 | ||
7699 | enum { | |
7700 | IF_STATE_ACTION = 0, | |
7701 | IF_STATE_SOURCE, | |
7702 | IF_STATE_END, | |
7703 | }; | |
7704 | ||
7705 | static const match_table_t if_tokens = { | |
7706 | { IF_ACT_FILTER, "filter" }, | |
7707 | { IF_ACT_START, "start" }, | |
7708 | { IF_ACT_STOP, "stop" }, | |
7709 | { IF_SRC_FILE, "%u/%u@%s" }, | |
7710 | { IF_SRC_KERNEL, "%u/%u" }, | |
7711 | { IF_SRC_FILEADDR, "%u@%s" }, | |
7712 | { IF_SRC_KERNELADDR, "%u" }, | |
7713 | }; | |
7714 | ||
7715 | /* | |
7716 | * Address filter string parser | |
7717 | */ | |
7718 | static int | |
7719 | perf_event_parse_addr_filter(struct perf_event *event, char *fstr, | |
7720 | struct list_head *filters) | |
7721 | { | |
7722 | struct perf_addr_filter *filter = NULL; | |
7723 | char *start, *orig, *filename = NULL; | |
7724 | struct path path; | |
7725 | substring_t args[MAX_OPT_ARGS]; | |
7726 | int state = IF_STATE_ACTION, token; | |
7727 | unsigned int kernel = 0; | |
7728 | int ret = -EINVAL; | |
7729 | ||
7730 | orig = fstr = kstrdup(fstr, GFP_KERNEL); | |
7731 | if (!fstr) | |
7732 | return -ENOMEM; | |
7733 | ||
7734 | while ((start = strsep(&fstr, " ,\n")) != NULL) { | |
7735 | ret = -EINVAL; | |
7736 | ||
7737 | if (!*start) | |
7738 | continue; | |
7739 | ||
7740 | /* filter definition begins */ | |
7741 | if (state == IF_STATE_ACTION) { | |
7742 | filter = perf_addr_filter_new(event, filters); | |
7743 | if (!filter) | |
7744 | goto fail; | |
7745 | } | |
7746 | ||
7747 | token = match_token(start, if_tokens, args); | |
7748 | switch (token) { | |
7749 | case IF_ACT_FILTER: | |
7750 | case IF_ACT_START: | |
7751 | filter->filter = 1; | |
7752 | ||
7753 | case IF_ACT_STOP: | |
7754 | if (state != IF_STATE_ACTION) | |
7755 | goto fail; | |
7756 | ||
7757 | state = IF_STATE_SOURCE; | |
7758 | break; | |
7759 | ||
7760 | case IF_SRC_KERNELADDR: | |
7761 | case IF_SRC_KERNEL: | |
7762 | kernel = 1; | |
7763 | ||
7764 | case IF_SRC_FILEADDR: | |
7765 | case IF_SRC_FILE: | |
7766 | if (state != IF_STATE_SOURCE) | |
7767 | goto fail; | |
7768 | ||
7769 | if (token == IF_SRC_FILE || token == IF_SRC_KERNEL) | |
7770 | filter->range = 1; | |
7771 | ||
7772 | *args[0].to = 0; | |
7773 | ret = kstrtoul(args[0].from, 0, &filter->offset); | |
7774 | if (ret) | |
7775 | goto fail; | |
7776 | ||
7777 | if (filter->range) { | |
7778 | *args[1].to = 0; | |
7779 | ret = kstrtoul(args[1].from, 0, &filter->size); | |
7780 | if (ret) | |
7781 | goto fail; | |
7782 | } | |
7783 | ||
7784 | if (token == IF_SRC_FILE) { | |
7785 | filename = match_strdup(&args[2]); | |
7786 | if (!filename) { | |
7787 | ret = -ENOMEM; | |
7788 | goto fail; | |
7789 | } | |
7790 | } | |
7791 | ||
7792 | state = IF_STATE_END; | |
7793 | break; | |
7794 | ||
7795 | default: | |
7796 | goto fail; | |
7797 | } | |
7798 | ||
7799 | /* | |
7800 | * Filter definition is fully parsed, validate and install it. | |
7801 | * Make sure that it doesn't contradict itself or the event's | |
7802 | * attribute. | |
7803 | */ | |
7804 | if (state == IF_STATE_END) { | |
7805 | if (kernel && event->attr.exclude_kernel) | |
7806 | goto fail; | |
7807 | ||
7808 | if (!kernel) { | |
7809 | if (!filename) | |
7810 | goto fail; | |
7811 | ||
7812 | /* look up the path and grab its inode */ | |
7813 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
7814 | if (ret) | |
7815 | goto fail_free_name; | |
7816 | ||
7817 | filter->inode = igrab(d_inode(path.dentry)); | |
7818 | path_put(&path); | |
7819 | kfree(filename); | |
7820 | filename = NULL; | |
7821 | ||
7822 | ret = -EINVAL; | |
7823 | if (!filter->inode || | |
7824 | !S_ISREG(filter->inode->i_mode)) | |
7825 | /* free_filters_list() will iput() */ | |
7826 | goto fail; | |
7827 | } | |
7828 | ||
7829 | /* ready to consume more filters */ | |
7830 | state = IF_STATE_ACTION; | |
7831 | filter = NULL; | |
7832 | } | |
7833 | } | |
7834 | ||
7835 | if (state != IF_STATE_ACTION) | |
7836 | goto fail; | |
7837 | ||
7838 | kfree(orig); | |
7839 | ||
7840 | return 0; | |
7841 | ||
7842 | fail_free_name: | |
7843 | kfree(filename); | |
7844 | fail: | |
7845 | free_filters_list(filters); | |
7846 | kfree(orig); | |
7847 | ||
7848 | return ret; | |
7849 | } | |
7850 | ||
7851 | static int | |
7852 | perf_event_set_addr_filter(struct perf_event *event, char *filter_str) | |
7853 | { | |
7854 | LIST_HEAD(filters); | |
7855 | int ret; | |
7856 | ||
7857 | /* | |
7858 | * Since this is called in perf_ioctl() path, we're already holding | |
7859 | * ctx::mutex. | |
7860 | */ | |
7861 | lockdep_assert_held(&event->ctx->mutex); | |
7862 | ||
7863 | if (WARN_ON_ONCE(event->parent)) | |
7864 | return -EINVAL; | |
7865 | ||
7866 | /* | |
7867 | * For now, we only support filtering in per-task events; doing so | |
7868 | * for CPU-wide events requires additional context switching trickery, | |
7869 | * since same object code will be mapped at different virtual | |
7870 | * addresses in different processes. | |
7871 | */ | |
7872 | if (!event->ctx->task) | |
7873 | return -EOPNOTSUPP; | |
7874 | ||
7875 | ret = perf_event_parse_addr_filter(event, filter_str, &filters); | |
7876 | if (ret) | |
7877 | return ret; | |
7878 | ||
7879 | ret = event->pmu->addr_filters_validate(&filters); | |
7880 | if (ret) { | |
7881 | free_filters_list(&filters); | |
7882 | return ret; | |
7883 | } | |
7884 | ||
7885 | /* remove existing filters, if any */ | |
7886 | perf_addr_filters_splice(event, &filters); | |
7887 | ||
7888 | /* install new filters */ | |
7889 | perf_event_for_each_child(event, perf_event_addr_filters_apply); | |
7890 | ||
7891 | return ret; | |
7892 | } | |
7893 | ||
c796bbbe AS |
7894 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) |
7895 | { | |
7896 | char *filter_str; | |
7897 | int ret = -EINVAL; | |
7898 | ||
375637bc AS |
7899 | if ((event->attr.type != PERF_TYPE_TRACEPOINT || |
7900 | !IS_ENABLED(CONFIG_EVENT_TRACING)) && | |
7901 | !has_addr_filter(event)) | |
c796bbbe AS |
7902 | return -EINVAL; |
7903 | ||
7904 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7905 | if (IS_ERR(filter_str)) | |
7906 | return PTR_ERR(filter_str); | |
7907 | ||
7908 | if (IS_ENABLED(CONFIG_EVENT_TRACING) && | |
7909 | event->attr.type == PERF_TYPE_TRACEPOINT) | |
7910 | ret = ftrace_profile_set_filter(event, event->attr.config, | |
7911 | filter_str); | |
375637bc AS |
7912 | else if (has_addr_filter(event)) |
7913 | ret = perf_event_set_addr_filter(event, filter_str); | |
c796bbbe AS |
7914 | |
7915 | kfree(filter_str); | |
7916 | return ret; | |
7917 | } | |
7918 | ||
b0a873eb PZ |
7919 | /* |
7920 | * hrtimer based swevent callback | |
7921 | */ | |
f29ac756 | 7922 | |
b0a873eb | 7923 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7924 | { |
b0a873eb PZ |
7925 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7926 | struct perf_sample_data data; | |
7927 | struct pt_regs *regs; | |
7928 | struct perf_event *event; | |
7929 | u64 period; | |
f29ac756 | 7930 | |
b0a873eb | 7931 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7932 | |
7933 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7934 | return HRTIMER_NORESTART; | |
7935 | ||
b0a873eb | 7936 | event->pmu->read(event); |
f344011c | 7937 | |
fd0d000b | 7938 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7939 | regs = get_irq_regs(); |
7940 | ||
7941 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7942 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7943 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7944 | ret = HRTIMER_NORESTART; |
7945 | } | |
24f1e32c | 7946 | |
b0a873eb PZ |
7947 | period = max_t(u64, 10000, event->hw.sample_period); |
7948 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7949 | |
b0a873eb | 7950 | return ret; |
f29ac756 PZ |
7951 | } |
7952 | ||
b0a873eb | 7953 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7954 | { |
b0a873eb | 7955 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7956 | s64 period; |
7957 | ||
7958 | if (!is_sampling_event(event)) | |
7959 | return; | |
f5ffe02e | 7960 | |
5d508e82 FBH |
7961 | period = local64_read(&hwc->period_left); |
7962 | if (period) { | |
7963 | if (period < 0) | |
7964 | period = 10000; | |
fa407f35 | 7965 | |
5d508e82 FBH |
7966 | local64_set(&hwc->period_left, 0); |
7967 | } else { | |
7968 | period = max_t(u64, 10000, hwc->sample_period); | |
7969 | } | |
3497d206 TG |
7970 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7971 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7972 | } |
b0a873eb PZ |
7973 | |
7974 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7975 | { |
b0a873eb PZ |
7976 | struct hw_perf_event *hwc = &event->hw; |
7977 | ||
6c7e550f | 7978 | if (is_sampling_event(event)) { |
b0a873eb | 7979 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7980 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7981 | |
7982 | hrtimer_cancel(&hwc->hrtimer); | |
7983 | } | |
24f1e32c FW |
7984 | } |
7985 | ||
ba3dd36c PZ |
7986 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7987 | { | |
7988 | struct hw_perf_event *hwc = &event->hw; | |
7989 | ||
7990 | if (!is_sampling_event(event)) | |
7991 | return; | |
7992 | ||
7993 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7994 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7995 | ||
7996 | /* | |
7997 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7998 | * mapping and avoid the whole period adjust feedback stuff. | |
7999 | */ | |
8000 | if (event->attr.freq) { | |
8001 | long freq = event->attr.sample_freq; | |
8002 | ||
8003 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
8004 | hwc->sample_period = event->attr.sample_period; | |
8005 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 8006 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
8007 | event->attr.freq = 0; |
8008 | } | |
8009 | } | |
8010 | ||
b0a873eb PZ |
8011 | /* |
8012 | * Software event: cpu wall time clock | |
8013 | */ | |
8014 | ||
8015 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 8016 | { |
b0a873eb PZ |
8017 | s64 prev; |
8018 | u64 now; | |
8019 | ||
a4eaf7f1 | 8020 | now = local_clock(); |
b0a873eb PZ |
8021 | prev = local64_xchg(&event->hw.prev_count, now); |
8022 | local64_add(now - prev, &event->count); | |
24f1e32c | 8023 | } |
24f1e32c | 8024 | |
a4eaf7f1 | 8025 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 8026 | { |
a4eaf7f1 | 8027 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 8028 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
8029 | } |
8030 | ||
a4eaf7f1 | 8031 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 8032 | { |
b0a873eb PZ |
8033 | perf_swevent_cancel_hrtimer(event); |
8034 | cpu_clock_event_update(event); | |
8035 | } | |
f29ac756 | 8036 | |
a4eaf7f1 PZ |
8037 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
8038 | { | |
8039 | if (flags & PERF_EF_START) | |
8040 | cpu_clock_event_start(event, flags); | |
6a694a60 | 8041 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
8042 | |
8043 | return 0; | |
8044 | } | |
8045 | ||
8046 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
8047 | { | |
8048 | cpu_clock_event_stop(event, flags); | |
8049 | } | |
8050 | ||
b0a873eb PZ |
8051 | static void cpu_clock_event_read(struct perf_event *event) |
8052 | { | |
8053 | cpu_clock_event_update(event); | |
8054 | } | |
f344011c | 8055 | |
b0a873eb PZ |
8056 | static int cpu_clock_event_init(struct perf_event *event) |
8057 | { | |
8058 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
8059 | return -ENOENT; | |
8060 | ||
8061 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
8062 | return -ENOENT; | |
8063 | ||
2481c5fa SE |
8064 | /* |
8065 | * no branch sampling for software events | |
8066 | */ | |
8067 | if (has_branch_stack(event)) | |
8068 | return -EOPNOTSUPP; | |
8069 | ||
ba3dd36c PZ |
8070 | perf_swevent_init_hrtimer(event); |
8071 | ||
b0a873eb | 8072 | return 0; |
f29ac756 PZ |
8073 | } |
8074 | ||
b0a873eb | 8075 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
8076 | .task_ctx_nr = perf_sw_context, |
8077 | ||
34f43927 PZ |
8078 | .capabilities = PERF_PMU_CAP_NO_NMI, |
8079 | ||
b0a873eb | 8080 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
8081 | .add = cpu_clock_event_add, |
8082 | .del = cpu_clock_event_del, | |
8083 | .start = cpu_clock_event_start, | |
8084 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
8085 | .read = cpu_clock_event_read, |
8086 | }; | |
8087 | ||
8088 | /* | |
8089 | * Software event: task time clock | |
8090 | */ | |
8091 | ||
8092 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 8093 | { |
b0a873eb PZ |
8094 | u64 prev; |
8095 | s64 delta; | |
5c92d124 | 8096 | |
b0a873eb PZ |
8097 | prev = local64_xchg(&event->hw.prev_count, now); |
8098 | delta = now - prev; | |
8099 | local64_add(delta, &event->count); | |
8100 | } | |
5c92d124 | 8101 | |
a4eaf7f1 | 8102 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 8103 | { |
a4eaf7f1 | 8104 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 8105 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
8106 | } |
8107 | ||
a4eaf7f1 | 8108 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
8109 | { |
8110 | perf_swevent_cancel_hrtimer(event); | |
8111 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
8112 | } |
8113 | ||
8114 | static int task_clock_event_add(struct perf_event *event, int flags) | |
8115 | { | |
8116 | if (flags & PERF_EF_START) | |
8117 | task_clock_event_start(event, flags); | |
6a694a60 | 8118 | perf_event_update_userpage(event); |
b0a873eb | 8119 | |
a4eaf7f1 PZ |
8120 | return 0; |
8121 | } | |
8122 | ||
8123 | static void task_clock_event_del(struct perf_event *event, int flags) | |
8124 | { | |
8125 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
8126 | } |
8127 | ||
8128 | static void task_clock_event_read(struct perf_event *event) | |
8129 | { | |
768a06e2 PZ |
8130 | u64 now = perf_clock(); |
8131 | u64 delta = now - event->ctx->timestamp; | |
8132 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
8133 | |
8134 | task_clock_event_update(event, time); | |
8135 | } | |
8136 | ||
8137 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 8138 | { |
b0a873eb PZ |
8139 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
8140 | return -ENOENT; | |
8141 | ||
8142 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
8143 | return -ENOENT; | |
8144 | ||
2481c5fa SE |
8145 | /* |
8146 | * no branch sampling for software events | |
8147 | */ | |
8148 | if (has_branch_stack(event)) | |
8149 | return -EOPNOTSUPP; | |
8150 | ||
ba3dd36c PZ |
8151 | perf_swevent_init_hrtimer(event); |
8152 | ||
b0a873eb | 8153 | return 0; |
6fb2915d LZ |
8154 | } |
8155 | ||
b0a873eb | 8156 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
8157 | .task_ctx_nr = perf_sw_context, |
8158 | ||
34f43927 PZ |
8159 | .capabilities = PERF_PMU_CAP_NO_NMI, |
8160 | ||
b0a873eb | 8161 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
8162 | .add = task_clock_event_add, |
8163 | .del = task_clock_event_del, | |
8164 | .start = task_clock_event_start, | |
8165 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
8166 | .read = task_clock_event_read, |
8167 | }; | |
6fb2915d | 8168 | |
ad5133b7 | 8169 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 8170 | { |
e077df4f | 8171 | } |
6fb2915d | 8172 | |
fbbe0701 SB |
8173 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
8174 | { | |
8175 | } | |
8176 | ||
ad5133b7 | 8177 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 8178 | { |
ad5133b7 | 8179 | return 0; |
6fb2915d LZ |
8180 | } |
8181 | ||
18ab2cd3 | 8182 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
8183 | |
8184 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 8185 | { |
fbbe0701 SB |
8186 | __this_cpu_write(nop_txn_flags, flags); |
8187 | ||
8188 | if (flags & ~PERF_PMU_TXN_ADD) | |
8189 | return; | |
8190 | ||
ad5133b7 | 8191 | perf_pmu_disable(pmu); |
6fb2915d LZ |
8192 | } |
8193 | ||
ad5133b7 PZ |
8194 | static int perf_pmu_commit_txn(struct pmu *pmu) |
8195 | { | |
fbbe0701 SB |
8196 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
8197 | ||
8198 | __this_cpu_write(nop_txn_flags, 0); | |
8199 | ||
8200 | if (flags & ~PERF_PMU_TXN_ADD) | |
8201 | return 0; | |
8202 | ||
ad5133b7 PZ |
8203 | perf_pmu_enable(pmu); |
8204 | return 0; | |
8205 | } | |
e077df4f | 8206 | |
ad5133b7 | 8207 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 8208 | { |
fbbe0701 SB |
8209 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
8210 | ||
8211 | __this_cpu_write(nop_txn_flags, 0); | |
8212 | ||
8213 | if (flags & ~PERF_PMU_TXN_ADD) | |
8214 | return; | |
8215 | ||
ad5133b7 | 8216 | perf_pmu_enable(pmu); |
24f1e32c FW |
8217 | } |
8218 | ||
35edc2a5 PZ |
8219 | static int perf_event_idx_default(struct perf_event *event) |
8220 | { | |
c719f560 | 8221 | return 0; |
35edc2a5 PZ |
8222 | } |
8223 | ||
8dc85d54 PZ |
8224 | /* |
8225 | * Ensures all contexts with the same task_ctx_nr have the same | |
8226 | * pmu_cpu_context too. | |
8227 | */ | |
9e317041 | 8228 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 8229 | { |
8dc85d54 | 8230 | struct pmu *pmu; |
b326e956 | 8231 | |
8dc85d54 PZ |
8232 | if (ctxn < 0) |
8233 | return NULL; | |
24f1e32c | 8234 | |
8dc85d54 PZ |
8235 | list_for_each_entry(pmu, &pmus, entry) { |
8236 | if (pmu->task_ctx_nr == ctxn) | |
8237 | return pmu->pmu_cpu_context; | |
8238 | } | |
24f1e32c | 8239 | |
8dc85d54 | 8240 | return NULL; |
24f1e32c FW |
8241 | } |
8242 | ||
51676957 | 8243 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 8244 | { |
51676957 PZ |
8245 | int cpu; |
8246 | ||
8247 | for_each_possible_cpu(cpu) { | |
8248 | struct perf_cpu_context *cpuctx; | |
8249 | ||
8250 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
8251 | ||
3f1f3320 PZ |
8252 | if (cpuctx->unique_pmu == old_pmu) |
8253 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
8254 | } |
8255 | } | |
8256 | ||
8257 | static void free_pmu_context(struct pmu *pmu) | |
8258 | { | |
8259 | struct pmu *i; | |
f5ffe02e | 8260 | |
8dc85d54 | 8261 | mutex_lock(&pmus_lock); |
0475f9ea | 8262 | /* |
8dc85d54 | 8263 | * Like a real lame refcount. |
0475f9ea | 8264 | */ |
51676957 PZ |
8265 | list_for_each_entry(i, &pmus, entry) { |
8266 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
8267 | update_pmu_context(i, pmu); | |
8dc85d54 | 8268 | goto out; |
51676957 | 8269 | } |
8dc85d54 | 8270 | } |
d6d020e9 | 8271 | |
51676957 | 8272 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
8273 | out: |
8274 | mutex_unlock(&pmus_lock); | |
24f1e32c | 8275 | } |
2e80a82a | 8276 | static struct idr pmu_idr; |
d6d020e9 | 8277 | |
abe43400 PZ |
8278 | static ssize_t |
8279 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
8280 | { | |
8281 | struct pmu *pmu = dev_get_drvdata(dev); | |
8282 | ||
8283 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
8284 | } | |
90826ca7 | 8285 | static DEVICE_ATTR_RO(type); |
abe43400 | 8286 | |
62b85639 SE |
8287 | static ssize_t |
8288 | perf_event_mux_interval_ms_show(struct device *dev, | |
8289 | struct device_attribute *attr, | |
8290 | char *page) | |
8291 | { | |
8292 | struct pmu *pmu = dev_get_drvdata(dev); | |
8293 | ||
8294 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
8295 | } | |
8296 | ||
272325c4 PZ |
8297 | static DEFINE_MUTEX(mux_interval_mutex); |
8298 | ||
62b85639 SE |
8299 | static ssize_t |
8300 | perf_event_mux_interval_ms_store(struct device *dev, | |
8301 | struct device_attribute *attr, | |
8302 | const char *buf, size_t count) | |
8303 | { | |
8304 | struct pmu *pmu = dev_get_drvdata(dev); | |
8305 | int timer, cpu, ret; | |
8306 | ||
8307 | ret = kstrtoint(buf, 0, &timer); | |
8308 | if (ret) | |
8309 | return ret; | |
8310 | ||
8311 | if (timer < 1) | |
8312 | return -EINVAL; | |
8313 | ||
8314 | /* same value, noting to do */ | |
8315 | if (timer == pmu->hrtimer_interval_ms) | |
8316 | return count; | |
8317 | ||
272325c4 | 8318 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
8319 | pmu->hrtimer_interval_ms = timer; |
8320 | ||
8321 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
8322 | get_online_cpus(); |
8323 | for_each_online_cpu(cpu) { | |
62b85639 SE |
8324 | struct perf_cpu_context *cpuctx; |
8325 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
8326 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
8327 | ||
272325c4 PZ |
8328 | cpu_function_call(cpu, |
8329 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 8330 | } |
272325c4 PZ |
8331 | put_online_cpus(); |
8332 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
8333 | |
8334 | return count; | |
8335 | } | |
90826ca7 | 8336 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 8337 | |
90826ca7 GKH |
8338 | static struct attribute *pmu_dev_attrs[] = { |
8339 | &dev_attr_type.attr, | |
8340 | &dev_attr_perf_event_mux_interval_ms.attr, | |
8341 | NULL, | |
abe43400 | 8342 | }; |
90826ca7 | 8343 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
8344 | |
8345 | static int pmu_bus_running; | |
8346 | static struct bus_type pmu_bus = { | |
8347 | .name = "event_source", | |
90826ca7 | 8348 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
8349 | }; |
8350 | ||
8351 | static void pmu_dev_release(struct device *dev) | |
8352 | { | |
8353 | kfree(dev); | |
8354 | } | |
8355 | ||
8356 | static int pmu_dev_alloc(struct pmu *pmu) | |
8357 | { | |
8358 | int ret = -ENOMEM; | |
8359 | ||
8360 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
8361 | if (!pmu->dev) | |
8362 | goto out; | |
8363 | ||
0c9d42ed | 8364 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
8365 | device_initialize(pmu->dev); |
8366 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
8367 | if (ret) | |
8368 | goto free_dev; | |
8369 | ||
8370 | dev_set_drvdata(pmu->dev, pmu); | |
8371 | pmu->dev->bus = &pmu_bus; | |
8372 | pmu->dev->release = pmu_dev_release; | |
8373 | ret = device_add(pmu->dev); | |
8374 | if (ret) | |
8375 | goto free_dev; | |
8376 | ||
8377 | out: | |
8378 | return ret; | |
8379 | ||
8380 | free_dev: | |
8381 | put_device(pmu->dev); | |
8382 | goto out; | |
8383 | } | |
8384 | ||
547e9fd7 | 8385 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 8386 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 8387 | |
03d8e80b | 8388 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 8389 | { |
108b02cf | 8390 | int cpu, ret; |
24f1e32c | 8391 | |
b0a873eb | 8392 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
8393 | ret = -ENOMEM; |
8394 | pmu->pmu_disable_count = alloc_percpu(int); | |
8395 | if (!pmu->pmu_disable_count) | |
8396 | goto unlock; | |
f29ac756 | 8397 | |
2e80a82a PZ |
8398 | pmu->type = -1; |
8399 | if (!name) | |
8400 | goto skip_type; | |
8401 | pmu->name = name; | |
8402 | ||
8403 | if (type < 0) { | |
0e9c3be2 TH |
8404 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
8405 | if (type < 0) { | |
8406 | ret = type; | |
2e80a82a PZ |
8407 | goto free_pdc; |
8408 | } | |
8409 | } | |
8410 | pmu->type = type; | |
8411 | ||
abe43400 PZ |
8412 | if (pmu_bus_running) { |
8413 | ret = pmu_dev_alloc(pmu); | |
8414 | if (ret) | |
8415 | goto free_idr; | |
8416 | } | |
8417 | ||
2e80a82a | 8418 | skip_type: |
26657848 PZ |
8419 | if (pmu->task_ctx_nr == perf_hw_context) { |
8420 | static int hw_context_taken = 0; | |
8421 | ||
8422 | if (WARN_ON_ONCE(hw_context_taken)) | |
8423 | pmu->task_ctx_nr = perf_invalid_context; | |
8424 | ||
8425 | hw_context_taken = 1; | |
8426 | } | |
8427 | ||
8dc85d54 PZ |
8428 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
8429 | if (pmu->pmu_cpu_context) | |
8430 | goto got_cpu_context; | |
f29ac756 | 8431 | |
c4814202 | 8432 | ret = -ENOMEM; |
108b02cf PZ |
8433 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
8434 | if (!pmu->pmu_cpu_context) | |
abe43400 | 8435 | goto free_dev; |
f344011c | 8436 | |
108b02cf PZ |
8437 | for_each_possible_cpu(cpu) { |
8438 | struct perf_cpu_context *cpuctx; | |
8439 | ||
8440 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 8441 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 8442 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 8443 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 8444 | cpuctx->ctx.pmu = pmu; |
9e630205 | 8445 | |
272325c4 | 8446 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 8447 | |
3f1f3320 | 8448 | cpuctx->unique_pmu = pmu; |
108b02cf | 8449 | } |
76e1d904 | 8450 | |
8dc85d54 | 8451 | got_cpu_context: |
ad5133b7 PZ |
8452 | if (!pmu->start_txn) { |
8453 | if (pmu->pmu_enable) { | |
8454 | /* | |
8455 | * If we have pmu_enable/pmu_disable calls, install | |
8456 | * transaction stubs that use that to try and batch | |
8457 | * hardware accesses. | |
8458 | */ | |
8459 | pmu->start_txn = perf_pmu_start_txn; | |
8460 | pmu->commit_txn = perf_pmu_commit_txn; | |
8461 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
8462 | } else { | |
fbbe0701 | 8463 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
8464 | pmu->commit_txn = perf_pmu_nop_int; |
8465 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 8466 | } |
5c92d124 | 8467 | } |
15dbf27c | 8468 | |
ad5133b7 PZ |
8469 | if (!pmu->pmu_enable) { |
8470 | pmu->pmu_enable = perf_pmu_nop_void; | |
8471 | pmu->pmu_disable = perf_pmu_nop_void; | |
8472 | } | |
8473 | ||
35edc2a5 PZ |
8474 | if (!pmu->event_idx) |
8475 | pmu->event_idx = perf_event_idx_default; | |
8476 | ||
b0a873eb | 8477 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 8478 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
8479 | ret = 0; |
8480 | unlock: | |
b0a873eb PZ |
8481 | mutex_unlock(&pmus_lock); |
8482 | ||
33696fc0 | 8483 | return ret; |
108b02cf | 8484 | |
abe43400 PZ |
8485 | free_dev: |
8486 | device_del(pmu->dev); | |
8487 | put_device(pmu->dev); | |
8488 | ||
2e80a82a PZ |
8489 | free_idr: |
8490 | if (pmu->type >= PERF_TYPE_MAX) | |
8491 | idr_remove(&pmu_idr, pmu->type); | |
8492 | ||
108b02cf PZ |
8493 | free_pdc: |
8494 | free_percpu(pmu->pmu_disable_count); | |
8495 | goto unlock; | |
f29ac756 | 8496 | } |
c464c76e | 8497 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 8498 | |
b0a873eb | 8499 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 8500 | { |
b0a873eb PZ |
8501 | mutex_lock(&pmus_lock); |
8502 | list_del_rcu(&pmu->entry); | |
8503 | mutex_unlock(&pmus_lock); | |
5c92d124 | 8504 | |
0475f9ea | 8505 | /* |
cde8e884 PZ |
8506 | * We dereference the pmu list under both SRCU and regular RCU, so |
8507 | * synchronize against both of those. | |
0475f9ea | 8508 | */ |
b0a873eb | 8509 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 8510 | synchronize_rcu(); |
d6d020e9 | 8511 | |
33696fc0 | 8512 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
8513 | if (pmu->type >= PERF_TYPE_MAX) |
8514 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
8515 | device_del(pmu->dev); |
8516 | put_device(pmu->dev); | |
51676957 | 8517 | free_pmu_context(pmu); |
b0a873eb | 8518 | } |
c464c76e | 8519 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 8520 | |
cc34b98b MR |
8521 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
8522 | { | |
ccd41c86 | 8523 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
8524 | int ret; |
8525 | ||
8526 | if (!try_module_get(pmu->module)) | |
8527 | return -ENODEV; | |
ccd41c86 PZ |
8528 | |
8529 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
8530 | /* |
8531 | * This ctx->mutex can nest when we're called through | |
8532 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
8533 | */ | |
8534 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
8535 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
8536 | BUG_ON(!ctx); |
8537 | } | |
8538 | ||
cc34b98b MR |
8539 | event->pmu = pmu; |
8540 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
8541 | |
8542 | if (ctx) | |
8543 | perf_event_ctx_unlock(event->group_leader, ctx); | |
8544 | ||
cc34b98b MR |
8545 | if (ret) |
8546 | module_put(pmu->module); | |
8547 | ||
8548 | return ret; | |
8549 | } | |
8550 | ||
18ab2cd3 | 8551 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
8552 | { |
8553 | struct pmu *pmu = NULL; | |
8554 | int idx; | |
940c5b29 | 8555 | int ret; |
b0a873eb PZ |
8556 | |
8557 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
8558 | |
8559 | rcu_read_lock(); | |
8560 | pmu = idr_find(&pmu_idr, event->attr.type); | |
8561 | rcu_read_unlock(); | |
940c5b29 | 8562 | if (pmu) { |
cc34b98b | 8563 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
8564 | if (ret) |
8565 | pmu = ERR_PTR(ret); | |
2e80a82a | 8566 | goto unlock; |
940c5b29 | 8567 | } |
2e80a82a | 8568 | |
b0a873eb | 8569 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 8570 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 8571 | if (!ret) |
e5f4d339 | 8572 | goto unlock; |
76e1d904 | 8573 | |
b0a873eb PZ |
8574 | if (ret != -ENOENT) { |
8575 | pmu = ERR_PTR(ret); | |
e5f4d339 | 8576 | goto unlock; |
f344011c | 8577 | } |
5c92d124 | 8578 | } |
e5f4d339 PZ |
8579 | pmu = ERR_PTR(-ENOENT); |
8580 | unlock: | |
b0a873eb | 8581 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 8582 | |
4aeb0b42 | 8583 | return pmu; |
5c92d124 IM |
8584 | } |
8585 | ||
4beb31f3 FW |
8586 | static void account_event_cpu(struct perf_event *event, int cpu) |
8587 | { | |
8588 | if (event->parent) | |
8589 | return; | |
8590 | ||
4beb31f3 FW |
8591 | if (is_cgroup_event(event)) |
8592 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
8593 | } | |
8594 | ||
555e0c1e FW |
8595 | /* Freq events need the tick to stay alive (see perf_event_task_tick). */ |
8596 | static void account_freq_event_nohz(void) | |
8597 | { | |
8598 | #ifdef CONFIG_NO_HZ_FULL | |
8599 | /* Lock so we don't race with concurrent unaccount */ | |
8600 | spin_lock(&nr_freq_lock); | |
8601 | if (atomic_inc_return(&nr_freq_events) == 1) | |
8602 | tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS); | |
8603 | spin_unlock(&nr_freq_lock); | |
8604 | #endif | |
8605 | } | |
8606 | ||
8607 | static void account_freq_event(void) | |
8608 | { | |
8609 | if (tick_nohz_full_enabled()) | |
8610 | account_freq_event_nohz(); | |
8611 | else | |
8612 | atomic_inc(&nr_freq_events); | |
8613 | } | |
8614 | ||
8615 | ||
766d6c07 FW |
8616 | static void account_event(struct perf_event *event) |
8617 | { | |
25432ae9 PZ |
8618 | bool inc = false; |
8619 | ||
4beb31f3 FW |
8620 | if (event->parent) |
8621 | return; | |
8622 | ||
766d6c07 | 8623 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 8624 | inc = true; |
766d6c07 FW |
8625 | if (event->attr.mmap || event->attr.mmap_data) |
8626 | atomic_inc(&nr_mmap_events); | |
8627 | if (event->attr.comm) | |
8628 | atomic_inc(&nr_comm_events); | |
8629 | if (event->attr.task) | |
8630 | atomic_inc(&nr_task_events); | |
555e0c1e FW |
8631 | if (event->attr.freq) |
8632 | account_freq_event(); | |
45ac1403 AH |
8633 | if (event->attr.context_switch) { |
8634 | atomic_inc(&nr_switch_events); | |
25432ae9 | 8635 | inc = true; |
45ac1403 | 8636 | } |
4beb31f3 | 8637 | if (has_branch_stack(event)) |
25432ae9 | 8638 | inc = true; |
4beb31f3 | 8639 | if (is_cgroup_event(event)) |
25432ae9 PZ |
8640 | inc = true; |
8641 | ||
9107c89e PZ |
8642 | if (inc) { |
8643 | if (atomic_inc_not_zero(&perf_sched_count)) | |
8644 | goto enabled; | |
8645 | ||
8646 | mutex_lock(&perf_sched_mutex); | |
8647 | if (!atomic_read(&perf_sched_count)) { | |
8648 | static_branch_enable(&perf_sched_events); | |
8649 | /* | |
8650 | * Guarantee that all CPUs observe they key change and | |
8651 | * call the perf scheduling hooks before proceeding to | |
8652 | * install events that need them. | |
8653 | */ | |
8654 | synchronize_sched(); | |
8655 | } | |
8656 | /* | |
8657 | * Now that we have waited for the sync_sched(), allow further | |
8658 | * increments to by-pass the mutex. | |
8659 | */ | |
8660 | atomic_inc(&perf_sched_count); | |
8661 | mutex_unlock(&perf_sched_mutex); | |
8662 | } | |
8663 | enabled: | |
4beb31f3 FW |
8664 | |
8665 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
8666 | } |
8667 | ||
0793a61d | 8668 | /* |
cdd6c482 | 8669 | * Allocate and initialize a event structure |
0793a61d | 8670 | */ |
cdd6c482 | 8671 | static struct perf_event * |
c3f00c70 | 8672 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
8673 | struct task_struct *task, |
8674 | struct perf_event *group_leader, | |
8675 | struct perf_event *parent_event, | |
4dc0da86 | 8676 | perf_overflow_handler_t overflow_handler, |
79dff51e | 8677 | void *context, int cgroup_fd) |
0793a61d | 8678 | { |
51b0fe39 | 8679 | struct pmu *pmu; |
cdd6c482 IM |
8680 | struct perf_event *event; |
8681 | struct hw_perf_event *hwc; | |
90983b16 | 8682 | long err = -EINVAL; |
0793a61d | 8683 | |
66832eb4 ON |
8684 | if ((unsigned)cpu >= nr_cpu_ids) { |
8685 | if (!task || cpu != -1) | |
8686 | return ERR_PTR(-EINVAL); | |
8687 | } | |
8688 | ||
c3f00c70 | 8689 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 8690 | if (!event) |
d5d2bc0d | 8691 | return ERR_PTR(-ENOMEM); |
0793a61d | 8692 | |
04289bb9 | 8693 | /* |
cdd6c482 | 8694 | * Single events are their own group leaders, with an |
04289bb9 IM |
8695 | * empty sibling list: |
8696 | */ | |
8697 | if (!group_leader) | |
cdd6c482 | 8698 | group_leader = event; |
04289bb9 | 8699 | |
cdd6c482 IM |
8700 | mutex_init(&event->child_mutex); |
8701 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 8702 | |
cdd6c482 IM |
8703 | INIT_LIST_HEAD(&event->group_entry); |
8704 | INIT_LIST_HEAD(&event->event_entry); | |
8705 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 8706 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 8707 | INIT_LIST_HEAD(&event->active_entry); |
375637bc | 8708 | INIT_LIST_HEAD(&event->addr_filters.list); |
f3ae75de SE |
8709 | INIT_HLIST_NODE(&event->hlist_entry); |
8710 | ||
10c6db11 | 8711 | |
cdd6c482 | 8712 | init_waitqueue_head(&event->waitq); |
e360adbe | 8713 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 8714 | |
cdd6c482 | 8715 | mutex_init(&event->mmap_mutex); |
375637bc | 8716 | raw_spin_lock_init(&event->addr_filters.lock); |
7b732a75 | 8717 | |
a6fa941d | 8718 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
8719 | event->cpu = cpu; |
8720 | event->attr = *attr; | |
8721 | event->group_leader = group_leader; | |
8722 | event->pmu = NULL; | |
cdd6c482 | 8723 | event->oncpu = -1; |
a96bbc16 | 8724 | |
cdd6c482 | 8725 | event->parent = parent_event; |
b84fbc9f | 8726 | |
17cf22c3 | 8727 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 8728 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 8729 | |
cdd6c482 | 8730 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 8731 | |
d580ff86 PZ |
8732 | if (task) { |
8733 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 8734 | /* |
50f16a8b PZ |
8735 | * XXX pmu::event_init needs to know what task to account to |
8736 | * and we cannot use the ctx information because we need the | |
8737 | * pmu before we get a ctx. | |
d580ff86 | 8738 | */ |
50f16a8b | 8739 | event->hw.target = task; |
d580ff86 PZ |
8740 | } |
8741 | ||
34f43927 PZ |
8742 | event->clock = &local_clock; |
8743 | if (parent_event) | |
8744 | event->clock = parent_event->clock; | |
8745 | ||
4dc0da86 | 8746 | if (!overflow_handler && parent_event) { |
b326e956 | 8747 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
8748 | context = parent_event->overflow_handler_context; |
8749 | } | |
66832eb4 | 8750 | |
1879445d WN |
8751 | if (overflow_handler) { |
8752 | event->overflow_handler = overflow_handler; | |
8753 | event->overflow_handler_context = context; | |
9ecda41a WN |
8754 | } else if (is_write_backward(event)){ |
8755 | event->overflow_handler = perf_event_output_backward; | |
8756 | event->overflow_handler_context = NULL; | |
1879445d | 8757 | } else { |
9ecda41a | 8758 | event->overflow_handler = perf_event_output_forward; |
1879445d WN |
8759 | event->overflow_handler_context = NULL; |
8760 | } | |
97eaf530 | 8761 | |
0231bb53 | 8762 | perf_event__state_init(event); |
a86ed508 | 8763 | |
4aeb0b42 | 8764 | pmu = NULL; |
b8e83514 | 8765 | |
cdd6c482 | 8766 | hwc = &event->hw; |
bd2b5b12 | 8767 | hwc->sample_period = attr->sample_period; |
0d48696f | 8768 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 8769 | hwc->sample_period = 1; |
eced1dfc | 8770 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 8771 | |
e7850595 | 8772 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 8773 | |
2023b359 | 8774 | /* |
cdd6c482 | 8775 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 8776 | */ |
3dab77fb | 8777 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 8778 | goto err_ns; |
a46a2300 YZ |
8779 | |
8780 | if (!has_branch_stack(event)) | |
8781 | event->attr.branch_sample_type = 0; | |
2023b359 | 8782 | |
79dff51e MF |
8783 | if (cgroup_fd != -1) { |
8784 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
8785 | if (err) | |
8786 | goto err_ns; | |
8787 | } | |
8788 | ||
b0a873eb | 8789 | pmu = perf_init_event(event); |
4aeb0b42 | 8790 | if (!pmu) |
90983b16 FW |
8791 | goto err_ns; |
8792 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 8793 | err = PTR_ERR(pmu); |
90983b16 | 8794 | goto err_ns; |
621a01ea | 8795 | } |
d5d2bc0d | 8796 | |
bed5b25a AS |
8797 | err = exclusive_event_init(event); |
8798 | if (err) | |
8799 | goto err_pmu; | |
8800 | ||
375637bc AS |
8801 | if (has_addr_filter(event)) { |
8802 | event->addr_filters_offs = kcalloc(pmu->nr_addr_filters, | |
8803 | sizeof(unsigned long), | |
8804 | GFP_KERNEL); | |
8805 | if (!event->addr_filters_offs) | |
8806 | goto err_per_task; | |
8807 | ||
8808 | /* force hw sync on the address filters */ | |
8809 | event->addr_filters_gen = 1; | |
8810 | } | |
8811 | ||
cdd6c482 | 8812 | if (!event->parent) { |
927c7a9e FW |
8813 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
8814 | err = get_callchain_buffers(); | |
90983b16 | 8815 | if (err) |
375637bc | 8816 | goto err_addr_filters; |
d010b332 | 8817 | } |
f344011c | 8818 | } |
9ee318a7 | 8819 | |
927a5570 AS |
8820 | /* symmetric to unaccount_event() in _free_event() */ |
8821 | account_event(event); | |
8822 | ||
cdd6c482 | 8823 | return event; |
90983b16 | 8824 | |
375637bc AS |
8825 | err_addr_filters: |
8826 | kfree(event->addr_filters_offs); | |
8827 | ||
bed5b25a AS |
8828 | err_per_task: |
8829 | exclusive_event_destroy(event); | |
8830 | ||
90983b16 FW |
8831 | err_pmu: |
8832 | if (event->destroy) | |
8833 | event->destroy(event); | |
c464c76e | 8834 | module_put(pmu->module); |
90983b16 | 8835 | err_ns: |
79dff51e MF |
8836 | if (is_cgroup_event(event)) |
8837 | perf_detach_cgroup(event); | |
90983b16 FW |
8838 | if (event->ns) |
8839 | put_pid_ns(event->ns); | |
8840 | kfree(event); | |
8841 | ||
8842 | return ERR_PTR(err); | |
0793a61d TG |
8843 | } |
8844 | ||
cdd6c482 IM |
8845 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
8846 | struct perf_event_attr *attr) | |
974802ea | 8847 | { |
974802ea | 8848 | u32 size; |
cdf8073d | 8849 | int ret; |
974802ea PZ |
8850 | |
8851 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
8852 | return -EFAULT; | |
8853 | ||
8854 | /* | |
8855 | * zero the full structure, so that a short copy will be nice. | |
8856 | */ | |
8857 | memset(attr, 0, sizeof(*attr)); | |
8858 | ||
8859 | ret = get_user(size, &uattr->size); | |
8860 | if (ret) | |
8861 | return ret; | |
8862 | ||
8863 | if (size > PAGE_SIZE) /* silly large */ | |
8864 | goto err_size; | |
8865 | ||
8866 | if (!size) /* abi compat */ | |
8867 | size = PERF_ATTR_SIZE_VER0; | |
8868 | ||
8869 | if (size < PERF_ATTR_SIZE_VER0) | |
8870 | goto err_size; | |
8871 | ||
8872 | /* | |
8873 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
8874 | * ensure all the unknown bits are 0 - i.e. new |
8875 | * user-space does not rely on any kernel feature | |
8876 | * extensions we dont know about yet. | |
974802ea PZ |
8877 | */ |
8878 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
8879 | unsigned char __user *addr; |
8880 | unsigned char __user *end; | |
8881 | unsigned char val; | |
974802ea | 8882 | |
cdf8073d IS |
8883 | addr = (void __user *)uattr + sizeof(*attr); |
8884 | end = (void __user *)uattr + size; | |
974802ea | 8885 | |
cdf8073d | 8886 | for (; addr < end; addr++) { |
974802ea PZ |
8887 | ret = get_user(val, addr); |
8888 | if (ret) | |
8889 | return ret; | |
8890 | if (val) | |
8891 | goto err_size; | |
8892 | } | |
b3e62e35 | 8893 | size = sizeof(*attr); |
974802ea PZ |
8894 | } |
8895 | ||
8896 | ret = copy_from_user(attr, uattr, size); | |
8897 | if (ret) | |
8898 | return -EFAULT; | |
8899 | ||
cd757645 | 8900 | if (attr->__reserved_1) |
974802ea PZ |
8901 | return -EINVAL; |
8902 | ||
8903 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8904 | return -EINVAL; | |
8905 | ||
8906 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8907 | return -EINVAL; | |
8908 | ||
bce38cd5 SE |
8909 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8910 | u64 mask = attr->branch_sample_type; | |
8911 | ||
8912 | /* only using defined bits */ | |
8913 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8914 | return -EINVAL; | |
8915 | ||
8916 | /* at least one branch bit must be set */ | |
8917 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8918 | return -EINVAL; | |
8919 | ||
bce38cd5 SE |
8920 | /* propagate priv level, when not set for branch */ |
8921 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8922 | ||
8923 | /* exclude_kernel checked on syscall entry */ | |
8924 | if (!attr->exclude_kernel) | |
8925 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8926 | ||
8927 | if (!attr->exclude_user) | |
8928 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8929 | ||
8930 | if (!attr->exclude_hv) | |
8931 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8932 | /* | |
8933 | * adjust user setting (for HW filter setup) | |
8934 | */ | |
8935 | attr->branch_sample_type = mask; | |
8936 | } | |
e712209a SE |
8937 | /* privileged levels capture (kernel, hv): check permissions */ |
8938 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8939 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8940 | return -EACCES; | |
bce38cd5 | 8941 | } |
4018994f | 8942 | |
c5ebcedb | 8943 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8944 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8945 | if (ret) |
8946 | return ret; | |
8947 | } | |
8948 | ||
8949 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8950 | if (!arch_perf_have_user_stack_dump()) | |
8951 | return -ENOSYS; | |
8952 | ||
8953 | /* | |
8954 | * We have __u32 type for the size, but so far | |
8955 | * we can only use __u16 as maximum due to the | |
8956 | * __u16 sample size limit. | |
8957 | */ | |
8958 | if (attr->sample_stack_user >= USHRT_MAX) | |
8959 | ret = -EINVAL; | |
8960 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8961 | ret = -EINVAL; | |
8962 | } | |
4018994f | 8963 | |
60e2364e SE |
8964 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8965 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8966 | out: |
8967 | return ret; | |
8968 | ||
8969 | err_size: | |
8970 | put_user(sizeof(*attr), &uattr->size); | |
8971 | ret = -E2BIG; | |
8972 | goto out; | |
8973 | } | |
8974 | ||
ac9721f3 PZ |
8975 | static int |
8976 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8977 | { |
b69cf536 | 8978 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8979 | int ret = -EINVAL; |
8980 | ||
ac9721f3 | 8981 | if (!output_event) |
a4be7c27 PZ |
8982 | goto set; |
8983 | ||
ac9721f3 PZ |
8984 | /* don't allow circular references */ |
8985 | if (event == output_event) | |
a4be7c27 PZ |
8986 | goto out; |
8987 | ||
0f139300 PZ |
8988 | /* |
8989 | * Don't allow cross-cpu buffers | |
8990 | */ | |
8991 | if (output_event->cpu != event->cpu) | |
8992 | goto out; | |
8993 | ||
8994 | /* | |
76369139 | 8995 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8996 | */ |
8997 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8998 | goto out; | |
8999 | ||
34f43927 PZ |
9000 | /* |
9001 | * Mixing clocks in the same buffer is trouble you don't need. | |
9002 | */ | |
9003 | if (output_event->clock != event->clock) | |
9004 | goto out; | |
9005 | ||
9ecda41a WN |
9006 | /* |
9007 | * Either writing ring buffer from beginning or from end. | |
9008 | * Mixing is not allowed. | |
9009 | */ | |
9010 | if (is_write_backward(output_event) != is_write_backward(event)) | |
9011 | goto out; | |
9012 | ||
45bfb2e5 PZ |
9013 | /* |
9014 | * If both events generate aux data, they must be on the same PMU | |
9015 | */ | |
9016 | if (has_aux(event) && has_aux(output_event) && | |
9017 | event->pmu != output_event->pmu) | |
9018 | goto out; | |
9019 | ||
a4be7c27 | 9020 | set: |
cdd6c482 | 9021 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
9022 | /* Can't redirect output if we've got an active mmap() */ |
9023 | if (atomic_read(&event->mmap_count)) | |
9024 | goto unlock; | |
a4be7c27 | 9025 | |
ac9721f3 | 9026 | if (output_event) { |
76369139 FW |
9027 | /* get the rb we want to redirect to */ |
9028 | rb = ring_buffer_get(output_event); | |
9029 | if (!rb) | |
ac9721f3 | 9030 | goto unlock; |
a4be7c27 PZ |
9031 | } |
9032 | ||
b69cf536 | 9033 | ring_buffer_attach(event, rb); |
9bb5d40c | 9034 | |
a4be7c27 | 9035 | ret = 0; |
ac9721f3 PZ |
9036 | unlock: |
9037 | mutex_unlock(&event->mmap_mutex); | |
9038 | ||
a4be7c27 | 9039 | out: |
a4be7c27 PZ |
9040 | return ret; |
9041 | } | |
9042 | ||
f63a8daa PZ |
9043 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
9044 | { | |
9045 | if (b < a) | |
9046 | swap(a, b); | |
9047 | ||
9048 | mutex_lock(a); | |
9049 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
9050 | } | |
9051 | ||
34f43927 PZ |
9052 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
9053 | { | |
9054 | bool nmi_safe = false; | |
9055 | ||
9056 | switch (clk_id) { | |
9057 | case CLOCK_MONOTONIC: | |
9058 | event->clock = &ktime_get_mono_fast_ns; | |
9059 | nmi_safe = true; | |
9060 | break; | |
9061 | ||
9062 | case CLOCK_MONOTONIC_RAW: | |
9063 | event->clock = &ktime_get_raw_fast_ns; | |
9064 | nmi_safe = true; | |
9065 | break; | |
9066 | ||
9067 | case CLOCK_REALTIME: | |
9068 | event->clock = &ktime_get_real_ns; | |
9069 | break; | |
9070 | ||
9071 | case CLOCK_BOOTTIME: | |
9072 | event->clock = &ktime_get_boot_ns; | |
9073 | break; | |
9074 | ||
9075 | case CLOCK_TAI: | |
9076 | event->clock = &ktime_get_tai_ns; | |
9077 | break; | |
9078 | ||
9079 | default: | |
9080 | return -EINVAL; | |
9081 | } | |
9082 | ||
9083 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
9084 | return -EINVAL; | |
9085 | ||
9086 | return 0; | |
9087 | } | |
9088 | ||
0793a61d | 9089 | /** |
cdd6c482 | 9090 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 9091 | * |
cdd6c482 | 9092 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 9093 | * @pid: target pid |
9f66a381 | 9094 | * @cpu: target cpu |
cdd6c482 | 9095 | * @group_fd: group leader event fd |
0793a61d | 9096 | */ |
cdd6c482 IM |
9097 | SYSCALL_DEFINE5(perf_event_open, |
9098 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 9099 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 9100 | { |
b04243ef PZ |
9101 | struct perf_event *group_leader = NULL, *output_event = NULL; |
9102 | struct perf_event *event, *sibling; | |
cdd6c482 | 9103 | struct perf_event_attr attr; |
f63a8daa | 9104 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 9105 | struct file *event_file = NULL; |
2903ff01 | 9106 | struct fd group = {NULL, 0}; |
38a81da2 | 9107 | struct task_struct *task = NULL; |
89a1e187 | 9108 | struct pmu *pmu; |
ea635c64 | 9109 | int event_fd; |
b04243ef | 9110 | int move_group = 0; |
dc86cabe | 9111 | int err; |
a21b0b35 | 9112 | int f_flags = O_RDWR; |
79dff51e | 9113 | int cgroup_fd = -1; |
0793a61d | 9114 | |
2743a5b0 | 9115 | /* for future expandability... */ |
e5d1367f | 9116 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
9117 | return -EINVAL; |
9118 | ||
dc86cabe IM |
9119 | err = perf_copy_attr(attr_uptr, &attr); |
9120 | if (err) | |
9121 | return err; | |
eab656ae | 9122 | |
0764771d PZ |
9123 | if (!attr.exclude_kernel) { |
9124 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
9125 | return -EACCES; | |
9126 | } | |
9127 | ||
df58ab24 | 9128 | if (attr.freq) { |
cdd6c482 | 9129 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 9130 | return -EINVAL; |
0819b2e3 PZ |
9131 | } else { |
9132 | if (attr.sample_period & (1ULL << 63)) | |
9133 | return -EINVAL; | |
df58ab24 PZ |
9134 | } |
9135 | ||
e5d1367f SE |
9136 | /* |
9137 | * In cgroup mode, the pid argument is used to pass the fd | |
9138 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
9139 | * designates the cpu on which to monitor threads from that | |
9140 | * cgroup. | |
9141 | */ | |
9142 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
9143 | return -EINVAL; | |
9144 | ||
a21b0b35 YD |
9145 | if (flags & PERF_FLAG_FD_CLOEXEC) |
9146 | f_flags |= O_CLOEXEC; | |
9147 | ||
9148 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
9149 | if (event_fd < 0) |
9150 | return event_fd; | |
9151 | ||
ac9721f3 | 9152 | if (group_fd != -1) { |
2903ff01 AV |
9153 | err = perf_fget_light(group_fd, &group); |
9154 | if (err) | |
d14b12d7 | 9155 | goto err_fd; |
2903ff01 | 9156 | group_leader = group.file->private_data; |
ac9721f3 PZ |
9157 | if (flags & PERF_FLAG_FD_OUTPUT) |
9158 | output_event = group_leader; | |
9159 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
9160 | group_leader = NULL; | |
9161 | } | |
9162 | ||
e5d1367f | 9163 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
9164 | task = find_lively_task_by_vpid(pid); |
9165 | if (IS_ERR(task)) { | |
9166 | err = PTR_ERR(task); | |
9167 | goto err_group_fd; | |
9168 | } | |
9169 | } | |
9170 | ||
1f4ee503 PZ |
9171 | if (task && group_leader && |
9172 | group_leader->attr.inherit != attr.inherit) { | |
9173 | err = -EINVAL; | |
9174 | goto err_task; | |
9175 | } | |
9176 | ||
fbfc623f YZ |
9177 | get_online_cpus(); |
9178 | ||
79c9ce57 PZ |
9179 | if (task) { |
9180 | err = mutex_lock_interruptible(&task->signal->cred_guard_mutex); | |
9181 | if (err) | |
9182 | goto err_cpus; | |
9183 | ||
9184 | /* | |
9185 | * Reuse ptrace permission checks for now. | |
9186 | * | |
9187 | * We must hold cred_guard_mutex across this and any potential | |
9188 | * perf_install_in_context() call for this new event to | |
9189 | * serialize against exec() altering our credentials (and the | |
9190 | * perf_event_exit_task() that could imply). | |
9191 | */ | |
9192 | err = -EACCES; | |
9193 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) | |
9194 | goto err_cred; | |
9195 | } | |
9196 | ||
79dff51e MF |
9197 | if (flags & PERF_FLAG_PID_CGROUP) |
9198 | cgroup_fd = pid; | |
9199 | ||
4dc0da86 | 9200 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 9201 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
9202 | if (IS_ERR(event)) { |
9203 | err = PTR_ERR(event); | |
79c9ce57 | 9204 | goto err_cred; |
d14b12d7 SE |
9205 | } |
9206 | ||
53b25335 VW |
9207 | if (is_sampling_event(event)) { |
9208 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
9209 | err = -ENOTSUPP; | |
9210 | goto err_alloc; | |
9211 | } | |
9212 | } | |
9213 | ||
89a1e187 PZ |
9214 | /* |
9215 | * Special case software events and allow them to be part of | |
9216 | * any hardware group. | |
9217 | */ | |
9218 | pmu = event->pmu; | |
b04243ef | 9219 | |
34f43927 PZ |
9220 | if (attr.use_clockid) { |
9221 | err = perf_event_set_clock(event, attr.clockid); | |
9222 | if (err) | |
9223 | goto err_alloc; | |
9224 | } | |
9225 | ||
b04243ef PZ |
9226 | if (group_leader && |
9227 | (is_software_event(event) != is_software_event(group_leader))) { | |
9228 | if (is_software_event(event)) { | |
9229 | /* | |
9230 | * If event and group_leader are not both a software | |
9231 | * event, and event is, then group leader is not. | |
9232 | * | |
9233 | * Allow the addition of software events to !software | |
9234 | * groups, this is safe because software events never | |
9235 | * fail to schedule. | |
9236 | */ | |
9237 | pmu = group_leader->pmu; | |
9238 | } else if (is_software_event(group_leader) && | |
9239 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
9240 | /* | |
9241 | * In case the group is a pure software group, and we | |
9242 | * try to add a hardware event, move the whole group to | |
9243 | * the hardware context. | |
9244 | */ | |
9245 | move_group = 1; | |
9246 | } | |
9247 | } | |
89a1e187 PZ |
9248 | |
9249 | /* | |
9250 | * Get the target context (task or percpu): | |
9251 | */ | |
4af57ef2 | 9252 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
9253 | if (IS_ERR(ctx)) { |
9254 | err = PTR_ERR(ctx); | |
c6be5a5c | 9255 | goto err_alloc; |
89a1e187 PZ |
9256 | } |
9257 | ||
bed5b25a AS |
9258 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
9259 | err = -EBUSY; | |
9260 | goto err_context; | |
9261 | } | |
9262 | ||
ccff286d | 9263 | /* |
cdd6c482 | 9264 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 9265 | */ |
ac9721f3 | 9266 | if (group_leader) { |
dc86cabe | 9267 | err = -EINVAL; |
04289bb9 | 9268 | |
04289bb9 | 9269 | /* |
ccff286d IM |
9270 | * Do not allow a recursive hierarchy (this new sibling |
9271 | * becoming part of another group-sibling): | |
9272 | */ | |
9273 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 9274 | goto err_context; |
34f43927 PZ |
9275 | |
9276 | /* All events in a group should have the same clock */ | |
9277 | if (group_leader->clock != event->clock) | |
9278 | goto err_context; | |
9279 | ||
ccff286d IM |
9280 | /* |
9281 | * Do not allow to attach to a group in a different | |
9282 | * task or CPU context: | |
04289bb9 | 9283 | */ |
b04243ef | 9284 | if (move_group) { |
c3c87e77 PZ |
9285 | /* |
9286 | * Make sure we're both on the same task, or both | |
9287 | * per-cpu events. | |
9288 | */ | |
9289 | if (group_leader->ctx->task != ctx->task) | |
9290 | goto err_context; | |
9291 | ||
9292 | /* | |
9293 | * Make sure we're both events for the same CPU; | |
9294 | * grouping events for different CPUs is broken; since | |
9295 | * you can never concurrently schedule them anyhow. | |
9296 | */ | |
9297 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
9298 | goto err_context; |
9299 | } else { | |
9300 | if (group_leader->ctx != ctx) | |
9301 | goto err_context; | |
9302 | } | |
9303 | ||
3b6f9e5c PM |
9304 | /* |
9305 | * Only a group leader can be exclusive or pinned | |
9306 | */ | |
0d48696f | 9307 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 9308 | goto err_context; |
ac9721f3 PZ |
9309 | } |
9310 | ||
9311 | if (output_event) { | |
9312 | err = perf_event_set_output(event, output_event); | |
9313 | if (err) | |
c3f00c70 | 9314 | goto err_context; |
ac9721f3 | 9315 | } |
0793a61d | 9316 | |
a21b0b35 YD |
9317 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
9318 | f_flags); | |
ea635c64 AV |
9319 | if (IS_ERR(event_file)) { |
9320 | err = PTR_ERR(event_file); | |
201c2f85 | 9321 | event_file = NULL; |
c3f00c70 | 9322 | goto err_context; |
ea635c64 | 9323 | } |
9b51f66d | 9324 | |
b04243ef | 9325 | if (move_group) { |
f63a8daa | 9326 | gctx = group_leader->ctx; |
f55fc2a5 | 9327 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
84c4e620 PZ |
9328 | if (gctx->task == TASK_TOMBSTONE) { |
9329 | err = -ESRCH; | |
9330 | goto err_locked; | |
9331 | } | |
f55fc2a5 PZ |
9332 | } else { |
9333 | mutex_lock(&ctx->mutex); | |
9334 | } | |
9335 | ||
84c4e620 PZ |
9336 | if (ctx->task == TASK_TOMBSTONE) { |
9337 | err = -ESRCH; | |
9338 | goto err_locked; | |
9339 | } | |
9340 | ||
a723968c PZ |
9341 | if (!perf_event_validate_size(event)) { |
9342 | err = -E2BIG; | |
9343 | goto err_locked; | |
9344 | } | |
9345 | ||
f55fc2a5 PZ |
9346 | /* |
9347 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
9348 | * because we need to serialize with concurrent event creation. | |
9349 | */ | |
9350 | if (!exclusive_event_installable(event, ctx)) { | |
9351 | /* exclusive and group stuff are assumed mutually exclusive */ | |
9352 | WARN_ON_ONCE(move_group); | |
f63a8daa | 9353 | |
f55fc2a5 PZ |
9354 | err = -EBUSY; |
9355 | goto err_locked; | |
9356 | } | |
f63a8daa | 9357 | |
f55fc2a5 PZ |
9358 | WARN_ON_ONCE(ctx->parent_ctx); |
9359 | ||
79c9ce57 PZ |
9360 | /* |
9361 | * This is the point on no return; we cannot fail hereafter. This is | |
9362 | * where we start modifying current state. | |
9363 | */ | |
9364 | ||
f55fc2a5 | 9365 | if (move_group) { |
f63a8daa PZ |
9366 | /* |
9367 | * See perf_event_ctx_lock() for comments on the details | |
9368 | * of swizzling perf_event::ctx. | |
9369 | */ | |
45a0e07a | 9370 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 9371 | |
b04243ef PZ |
9372 | list_for_each_entry(sibling, &group_leader->sibling_list, |
9373 | group_entry) { | |
45a0e07a | 9374 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
9375 | put_ctx(gctx); |
9376 | } | |
b04243ef | 9377 | |
f63a8daa PZ |
9378 | /* |
9379 | * Wait for everybody to stop referencing the events through | |
9380 | * the old lists, before installing it on new lists. | |
9381 | */ | |
0cda4c02 | 9382 | synchronize_rcu(); |
f63a8daa | 9383 | |
8f95b435 PZI |
9384 | /* |
9385 | * Install the group siblings before the group leader. | |
9386 | * | |
9387 | * Because a group leader will try and install the entire group | |
9388 | * (through the sibling list, which is still in-tact), we can | |
9389 | * end up with siblings installed in the wrong context. | |
9390 | * | |
9391 | * By installing siblings first we NO-OP because they're not | |
9392 | * reachable through the group lists. | |
9393 | */ | |
b04243ef PZ |
9394 | list_for_each_entry(sibling, &group_leader->sibling_list, |
9395 | group_entry) { | |
8f95b435 | 9396 | perf_event__state_init(sibling); |
9fc81d87 | 9397 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
9398 | get_ctx(ctx); |
9399 | } | |
8f95b435 PZI |
9400 | |
9401 | /* | |
9402 | * Removing from the context ends up with disabled | |
9403 | * event. What we want here is event in the initial | |
9404 | * startup state, ready to be add into new context. | |
9405 | */ | |
9406 | perf_event__state_init(group_leader); | |
9407 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
9408 | get_ctx(ctx); | |
b04243ef | 9409 | |
f55fc2a5 PZ |
9410 | /* |
9411 | * Now that all events are installed in @ctx, nothing | |
9412 | * references @gctx anymore, so drop the last reference we have | |
9413 | * on it. | |
9414 | */ | |
9415 | put_ctx(gctx); | |
bed5b25a AS |
9416 | } |
9417 | ||
f73e22ab PZ |
9418 | /* |
9419 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
9420 | * that we're serialized against further additions and before | |
9421 | * perf_install_in_context() which is the point the event is active and | |
9422 | * can use these values. | |
9423 | */ | |
9424 | perf_event__header_size(event); | |
9425 | perf_event__id_header_size(event); | |
9426 | ||
78cd2c74 PZ |
9427 | event->owner = current; |
9428 | ||
e2d37cd2 | 9429 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 9430 | perf_unpin_context(ctx); |
f63a8daa | 9431 | |
f55fc2a5 | 9432 | if (move_group) |
f63a8daa | 9433 | mutex_unlock(&gctx->mutex); |
d859e29f | 9434 | mutex_unlock(&ctx->mutex); |
9b51f66d | 9435 | |
79c9ce57 PZ |
9436 | if (task) { |
9437 | mutex_unlock(&task->signal->cred_guard_mutex); | |
9438 | put_task_struct(task); | |
9439 | } | |
9440 | ||
fbfc623f YZ |
9441 | put_online_cpus(); |
9442 | ||
cdd6c482 IM |
9443 | mutex_lock(¤t->perf_event_mutex); |
9444 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
9445 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 9446 | |
8a49542c PZ |
9447 | /* |
9448 | * Drop the reference on the group_event after placing the | |
9449 | * new event on the sibling_list. This ensures destruction | |
9450 | * of the group leader will find the pointer to itself in | |
9451 | * perf_group_detach(). | |
9452 | */ | |
2903ff01 | 9453 | fdput(group); |
ea635c64 AV |
9454 | fd_install(event_fd, event_file); |
9455 | return event_fd; | |
0793a61d | 9456 | |
f55fc2a5 PZ |
9457 | err_locked: |
9458 | if (move_group) | |
9459 | mutex_unlock(&gctx->mutex); | |
9460 | mutex_unlock(&ctx->mutex); | |
9461 | /* err_file: */ | |
9462 | fput(event_file); | |
c3f00c70 | 9463 | err_context: |
fe4b04fa | 9464 | perf_unpin_context(ctx); |
ea635c64 | 9465 | put_ctx(ctx); |
c6be5a5c | 9466 | err_alloc: |
13005627 PZ |
9467 | /* |
9468 | * If event_file is set, the fput() above will have called ->release() | |
9469 | * and that will take care of freeing the event. | |
9470 | */ | |
9471 | if (!event_file) | |
9472 | free_event(event); | |
79c9ce57 PZ |
9473 | err_cred: |
9474 | if (task) | |
9475 | mutex_unlock(&task->signal->cred_guard_mutex); | |
1f4ee503 | 9476 | err_cpus: |
fbfc623f | 9477 | put_online_cpus(); |
1f4ee503 | 9478 | err_task: |
e7d0bc04 PZ |
9479 | if (task) |
9480 | put_task_struct(task); | |
89a1e187 | 9481 | err_group_fd: |
2903ff01 | 9482 | fdput(group); |
ea635c64 AV |
9483 | err_fd: |
9484 | put_unused_fd(event_fd); | |
dc86cabe | 9485 | return err; |
0793a61d TG |
9486 | } |
9487 | ||
fb0459d7 AV |
9488 | /** |
9489 | * perf_event_create_kernel_counter | |
9490 | * | |
9491 | * @attr: attributes of the counter to create | |
9492 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 9493 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
9494 | */ |
9495 | struct perf_event * | |
9496 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 9497 | struct task_struct *task, |
4dc0da86 AK |
9498 | perf_overflow_handler_t overflow_handler, |
9499 | void *context) | |
fb0459d7 | 9500 | { |
fb0459d7 | 9501 | struct perf_event_context *ctx; |
c3f00c70 | 9502 | struct perf_event *event; |
fb0459d7 | 9503 | int err; |
d859e29f | 9504 | |
fb0459d7 AV |
9505 | /* |
9506 | * Get the target context (task or percpu): | |
9507 | */ | |
d859e29f | 9508 | |
4dc0da86 | 9509 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 9510 | overflow_handler, context, -1); |
c3f00c70 PZ |
9511 | if (IS_ERR(event)) { |
9512 | err = PTR_ERR(event); | |
9513 | goto err; | |
9514 | } | |
d859e29f | 9515 | |
f8697762 | 9516 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 9517 | event->owner = TASK_TOMBSTONE; |
f8697762 | 9518 | |
4af57ef2 | 9519 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
9520 | if (IS_ERR(ctx)) { |
9521 | err = PTR_ERR(ctx); | |
c3f00c70 | 9522 | goto err_free; |
d859e29f | 9523 | } |
fb0459d7 | 9524 | |
fb0459d7 AV |
9525 | WARN_ON_ONCE(ctx->parent_ctx); |
9526 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
9527 | if (ctx->task == TASK_TOMBSTONE) { |
9528 | err = -ESRCH; | |
9529 | goto err_unlock; | |
9530 | } | |
9531 | ||
bed5b25a | 9532 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 9533 | err = -EBUSY; |
84c4e620 | 9534 | goto err_unlock; |
bed5b25a AS |
9535 | } |
9536 | ||
fb0459d7 | 9537 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 9538 | perf_unpin_context(ctx); |
fb0459d7 AV |
9539 | mutex_unlock(&ctx->mutex); |
9540 | ||
fb0459d7 AV |
9541 | return event; |
9542 | ||
84c4e620 PZ |
9543 | err_unlock: |
9544 | mutex_unlock(&ctx->mutex); | |
9545 | perf_unpin_context(ctx); | |
9546 | put_ctx(ctx); | |
c3f00c70 PZ |
9547 | err_free: |
9548 | free_event(event); | |
9549 | err: | |
c6567f64 | 9550 | return ERR_PTR(err); |
9b51f66d | 9551 | } |
fb0459d7 | 9552 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 9553 | |
0cda4c02 YZ |
9554 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
9555 | { | |
9556 | struct perf_event_context *src_ctx; | |
9557 | struct perf_event_context *dst_ctx; | |
9558 | struct perf_event *event, *tmp; | |
9559 | LIST_HEAD(events); | |
9560 | ||
9561 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
9562 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
9563 | ||
f63a8daa PZ |
9564 | /* |
9565 | * See perf_event_ctx_lock() for comments on the details | |
9566 | * of swizzling perf_event::ctx. | |
9567 | */ | |
9568 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
9569 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
9570 | event_entry) { | |
45a0e07a | 9571 | perf_remove_from_context(event, 0); |
9a545de0 | 9572 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 9573 | put_ctx(src_ctx); |
9886167d | 9574 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 9575 | } |
0cda4c02 | 9576 | |
8f95b435 PZI |
9577 | /* |
9578 | * Wait for the events to quiesce before re-instating them. | |
9579 | */ | |
0cda4c02 YZ |
9580 | synchronize_rcu(); |
9581 | ||
8f95b435 PZI |
9582 | /* |
9583 | * Re-instate events in 2 passes. | |
9584 | * | |
9585 | * Skip over group leaders and only install siblings on this first | |
9586 | * pass, siblings will not get enabled without a leader, however a | |
9587 | * leader will enable its siblings, even if those are still on the old | |
9588 | * context. | |
9589 | */ | |
9590 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
9591 | if (event->group_leader == event) | |
9592 | continue; | |
9593 | ||
9594 | list_del(&event->migrate_entry); | |
9595 | if (event->state >= PERF_EVENT_STATE_OFF) | |
9596 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9597 | account_event_cpu(event, dst_cpu); | |
9598 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
9599 | get_ctx(dst_ctx); | |
9600 | } | |
9601 | ||
9602 | /* | |
9603 | * Once all the siblings are setup properly, install the group leaders | |
9604 | * to make it go. | |
9605 | */ | |
9886167d PZ |
9606 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
9607 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
9608 | if (event->state >= PERF_EVENT_STATE_OFF) |
9609 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 9610 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
9611 | perf_install_in_context(dst_ctx, event, dst_cpu); |
9612 | get_ctx(dst_ctx); | |
9613 | } | |
9614 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 9615 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
9616 | } |
9617 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
9618 | ||
cdd6c482 | 9619 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 9620 | struct task_struct *child) |
d859e29f | 9621 | { |
cdd6c482 | 9622 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 9623 | u64 child_val; |
d859e29f | 9624 | |
cdd6c482 IM |
9625 | if (child_event->attr.inherit_stat) |
9626 | perf_event_read_event(child_event, child); | |
38b200d6 | 9627 | |
b5e58793 | 9628 | child_val = perf_event_count(child_event); |
d859e29f PM |
9629 | |
9630 | /* | |
9631 | * Add back the child's count to the parent's count: | |
9632 | */ | |
a6e6dea6 | 9633 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
9634 | atomic64_add(child_event->total_time_enabled, |
9635 | &parent_event->child_total_time_enabled); | |
9636 | atomic64_add(child_event->total_time_running, | |
9637 | &parent_event->child_total_time_running); | |
d859e29f PM |
9638 | } |
9639 | ||
9b51f66d | 9640 | static void |
8ba289b8 PZ |
9641 | perf_event_exit_event(struct perf_event *child_event, |
9642 | struct perf_event_context *child_ctx, | |
9643 | struct task_struct *child) | |
9b51f66d | 9644 | { |
8ba289b8 PZ |
9645 | struct perf_event *parent_event = child_event->parent; |
9646 | ||
1903d50c PZ |
9647 | /* |
9648 | * Do not destroy the 'original' grouping; because of the context | |
9649 | * switch optimization the original events could've ended up in a | |
9650 | * random child task. | |
9651 | * | |
9652 | * If we were to destroy the original group, all group related | |
9653 | * operations would cease to function properly after this random | |
9654 | * child dies. | |
9655 | * | |
9656 | * Do destroy all inherited groups, we don't care about those | |
9657 | * and being thorough is better. | |
9658 | */ | |
32132a3d PZ |
9659 | raw_spin_lock_irq(&child_ctx->lock); |
9660 | WARN_ON_ONCE(child_ctx->is_active); | |
9661 | ||
8ba289b8 | 9662 | if (parent_event) |
32132a3d PZ |
9663 | perf_group_detach(child_event); |
9664 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 9665 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 9666 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 9667 | |
9b51f66d | 9668 | /* |
8ba289b8 | 9669 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 9670 | */ |
8ba289b8 | 9671 | if (!parent_event) { |
179033b3 | 9672 | perf_event_wakeup(child_event); |
8ba289b8 | 9673 | return; |
4bcf349a | 9674 | } |
8ba289b8 PZ |
9675 | /* |
9676 | * Child events can be cleaned up. | |
9677 | */ | |
9678 | ||
9679 | sync_child_event(child_event, child); | |
9680 | ||
9681 | /* | |
9682 | * Remove this event from the parent's list | |
9683 | */ | |
9684 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
9685 | mutex_lock(&parent_event->child_mutex); | |
9686 | list_del_init(&child_event->child_list); | |
9687 | mutex_unlock(&parent_event->child_mutex); | |
9688 | ||
9689 | /* | |
9690 | * Kick perf_poll() for is_event_hup(). | |
9691 | */ | |
9692 | perf_event_wakeup(parent_event); | |
9693 | free_event(child_event); | |
9694 | put_event(parent_event); | |
9b51f66d IM |
9695 | } |
9696 | ||
8dc85d54 | 9697 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 9698 | { |
211de6eb | 9699 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 9700 | struct perf_event *child_event, *next; |
63b6da39 PZ |
9701 | |
9702 | WARN_ON_ONCE(child != current); | |
9b51f66d | 9703 | |
6a3351b6 | 9704 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 9705 | if (!child_ctx) |
9b51f66d IM |
9706 | return; |
9707 | ||
ad3a37de | 9708 | /* |
6a3351b6 PZ |
9709 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
9710 | * ctx::mutex over the entire thing. This serializes against almost | |
9711 | * everything that wants to access the ctx. | |
9712 | * | |
9713 | * The exception is sys_perf_event_open() / | |
9714 | * perf_event_create_kernel_count() which does find_get_context() | |
9715 | * without ctx::mutex (it cannot because of the move_group double mutex | |
9716 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 9717 | */ |
6a3351b6 | 9718 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
9719 | |
9720 | /* | |
6a3351b6 PZ |
9721 | * In a single ctx::lock section, de-schedule the events and detach the |
9722 | * context from the task such that we cannot ever get it scheduled back | |
9723 | * in. | |
c93f7669 | 9724 | */ |
6a3351b6 | 9725 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 9726 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 9727 | |
71a851b4 | 9728 | /* |
63b6da39 PZ |
9729 | * Now that the context is inactive, destroy the task <-> ctx relation |
9730 | * and mark the context dead. | |
71a851b4 | 9731 | */ |
63b6da39 PZ |
9732 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
9733 | put_ctx(child_ctx); /* cannot be last */ | |
9734 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
9735 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 9736 | |
211de6eb | 9737 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 9738 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 9739 | |
211de6eb PZ |
9740 | if (clone_ctx) |
9741 | put_ctx(clone_ctx); | |
4a1c0f26 | 9742 | |
9f498cc5 | 9743 | /* |
cdd6c482 IM |
9744 | * Report the task dead after unscheduling the events so that we |
9745 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
9746 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 9747 | */ |
cdd6c482 | 9748 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 9749 | |
ebf905fc | 9750 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 9751 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 9752 | |
a63eaf34 PM |
9753 | mutex_unlock(&child_ctx->mutex); |
9754 | ||
9755 | put_ctx(child_ctx); | |
9b51f66d IM |
9756 | } |
9757 | ||
8dc85d54 PZ |
9758 | /* |
9759 | * When a child task exits, feed back event values to parent events. | |
79c9ce57 PZ |
9760 | * |
9761 | * Can be called with cred_guard_mutex held when called from | |
9762 | * install_exec_creds(). | |
8dc85d54 PZ |
9763 | */ |
9764 | void perf_event_exit_task(struct task_struct *child) | |
9765 | { | |
8882135b | 9766 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
9767 | int ctxn; |
9768 | ||
8882135b PZ |
9769 | mutex_lock(&child->perf_event_mutex); |
9770 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
9771 | owner_entry) { | |
9772 | list_del_init(&event->owner_entry); | |
9773 | ||
9774 | /* | |
9775 | * Ensure the list deletion is visible before we clear | |
9776 | * the owner, closes a race against perf_release() where | |
9777 | * we need to serialize on the owner->perf_event_mutex. | |
9778 | */ | |
f47c02c0 | 9779 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
9780 | } |
9781 | mutex_unlock(&child->perf_event_mutex); | |
9782 | ||
8dc85d54 PZ |
9783 | for_each_task_context_nr(ctxn) |
9784 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
9785 | |
9786 | /* | |
9787 | * The perf_event_exit_task_context calls perf_event_task | |
9788 | * with child's task_ctx, which generates EXIT events for | |
9789 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
9790 | * At this point we need to send EXIT events to cpu contexts. | |
9791 | */ | |
9792 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
9793 | } |
9794 | ||
889ff015 FW |
9795 | static void perf_free_event(struct perf_event *event, |
9796 | struct perf_event_context *ctx) | |
9797 | { | |
9798 | struct perf_event *parent = event->parent; | |
9799 | ||
9800 | if (WARN_ON_ONCE(!parent)) | |
9801 | return; | |
9802 | ||
9803 | mutex_lock(&parent->child_mutex); | |
9804 | list_del_init(&event->child_list); | |
9805 | mutex_unlock(&parent->child_mutex); | |
9806 | ||
a6fa941d | 9807 | put_event(parent); |
889ff015 | 9808 | |
652884fe | 9809 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 9810 | perf_group_detach(event); |
889ff015 | 9811 | list_del_event(event, ctx); |
652884fe | 9812 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
9813 | free_event(event); |
9814 | } | |
9815 | ||
bbbee908 | 9816 | /* |
652884fe | 9817 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 9818 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
9819 | * |
9820 | * Not all locks are strictly required, but take them anyway to be nice and | |
9821 | * help out with the lockdep assertions. | |
bbbee908 | 9822 | */ |
cdd6c482 | 9823 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 9824 | { |
8dc85d54 | 9825 | struct perf_event_context *ctx; |
cdd6c482 | 9826 | struct perf_event *event, *tmp; |
8dc85d54 | 9827 | int ctxn; |
bbbee908 | 9828 | |
8dc85d54 PZ |
9829 | for_each_task_context_nr(ctxn) { |
9830 | ctx = task->perf_event_ctxp[ctxn]; | |
9831 | if (!ctx) | |
9832 | continue; | |
bbbee908 | 9833 | |
8dc85d54 | 9834 | mutex_lock(&ctx->mutex); |
bbbee908 | 9835 | again: |
8dc85d54 PZ |
9836 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
9837 | group_entry) | |
9838 | perf_free_event(event, ctx); | |
bbbee908 | 9839 | |
8dc85d54 PZ |
9840 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
9841 | group_entry) | |
9842 | perf_free_event(event, ctx); | |
bbbee908 | 9843 | |
8dc85d54 PZ |
9844 | if (!list_empty(&ctx->pinned_groups) || |
9845 | !list_empty(&ctx->flexible_groups)) | |
9846 | goto again; | |
bbbee908 | 9847 | |
8dc85d54 | 9848 | mutex_unlock(&ctx->mutex); |
bbbee908 | 9849 | |
8dc85d54 PZ |
9850 | put_ctx(ctx); |
9851 | } | |
889ff015 FW |
9852 | } |
9853 | ||
4e231c79 PZ |
9854 | void perf_event_delayed_put(struct task_struct *task) |
9855 | { | |
9856 | int ctxn; | |
9857 | ||
9858 | for_each_task_context_nr(ctxn) | |
9859 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
9860 | } | |
9861 | ||
e03e7ee3 | 9862 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 9863 | { |
e03e7ee3 | 9864 | struct file *file; |
ffe8690c | 9865 | |
e03e7ee3 AS |
9866 | file = fget_raw(fd); |
9867 | if (!file) | |
9868 | return ERR_PTR(-EBADF); | |
ffe8690c | 9869 | |
e03e7ee3 AS |
9870 | if (file->f_op != &perf_fops) { |
9871 | fput(file); | |
9872 | return ERR_PTR(-EBADF); | |
9873 | } | |
ffe8690c | 9874 | |
e03e7ee3 | 9875 | return file; |
ffe8690c KX |
9876 | } |
9877 | ||
9878 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
9879 | { | |
9880 | if (!event) | |
9881 | return ERR_PTR(-EINVAL); | |
9882 | ||
9883 | return &event->attr; | |
9884 | } | |
9885 | ||
97dee4f3 PZ |
9886 | /* |
9887 | * inherit a event from parent task to child task: | |
9888 | */ | |
9889 | static struct perf_event * | |
9890 | inherit_event(struct perf_event *parent_event, | |
9891 | struct task_struct *parent, | |
9892 | struct perf_event_context *parent_ctx, | |
9893 | struct task_struct *child, | |
9894 | struct perf_event *group_leader, | |
9895 | struct perf_event_context *child_ctx) | |
9896 | { | |
1929def9 | 9897 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 9898 | struct perf_event *child_event; |
cee010ec | 9899 | unsigned long flags; |
97dee4f3 PZ |
9900 | |
9901 | /* | |
9902 | * Instead of creating recursive hierarchies of events, | |
9903 | * we link inherited events back to the original parent, | |
9904 | * which has a filp for sure, which we use as the reference | |
9905 | * count: | |
9906 | */ | |
9907 | if (parent_event->parent) | |
9908 | parent_event = parent_event->parent; | |
9909 | ||
9910 | child_event = perf_event_alloc(&parent_event->attr, | |
9911 | parent_event->cpu, | |
d580ff86 | 9912 | child, |
97dee4f3 | 9913 | group_leader, parent_event, |
79dff51e | 9914 | NULL, NULL, -1); |
97dee4f3 PZ |
9915 | if (IS_ERR(child_event)) |
9916 | return child_event; | |
a6fa941d | 9917 | |
c6e5b732 PZ |
9918 | /* |
9919 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
9920 | * must be under the same lock in order to serialize against | |
9921 | * perf_event_release_kernel(), such that either we must observe | |
9922 | * is_orphaned_event() or they will observe us on the child_list. | |
9923 | */ | |
9924 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
9925 | if (is_orphaned_event(parent_event) || |
9926 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 9927 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
9928 | free_event(child_event); |
9929 | return NULL; | |
9930 | } | |
9931 | ||
97dee4f3 PZ |
9932 | get_ctx(child_ctx); |
9933 | ||
9934 | /* | |
9935 | * Make the child state follow the state of the parent event, | |
9936 | * not its attr.disabled bit. We hold the parent's mutex, | |
9937 | * so we won't race with perf_event_{en, dis}able_family. | |
9938 | */ | |
1929def9 | 9939 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
9940 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
9941 | else | |
9942 | child_event->state = PERF_EVENT_STATE_OFF; | |
9943 | ||
9944 | if (parent_event->attr.freq) { | |
9945 | u64 sample_period = parent_event->hw.sample_period; | |
9946 | struct hw_perf_event *hwc = &child_event->hw; | |
9947 | ||
9948 | hwc->sample_period = sample_period; | |
9949 | hwc->last_period = sample_period; | |
9950 | ||
9951 | local64_set(&hwc->period_left, sample_period); | |
9952 | } | |
9953 | ||
9954 | child_event->ctx = child_ctx; | |
9955 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9956 | child_event->overflow_handler_context |
9957 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9958 | |
614b6780 TG |
9959 | /* |
9960 | * Precalculate sample_data sizes | |
9961 | */ | |
9962 | perf_event__header_size(child_event); | |
6844c09d | 9963 | perf_event__id_header_size(child_event); |
614b6780 | 9964 | |
97dee4f3 PZ |
9965 | /* |
9966 | * Link it up in the child's context: | |
9967 | */ | |
cee010ec | 9968 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9969 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9970 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9971 | |
97dee4f3 PZ |
9972 | /* |
9973 | * Link this into the parent event's child list | |
9974 | */ | |
97dee4f3 PZ |
9975 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9976 | mutex_unlock(&parent_event->child_mutex); | |
9977 | ||
9978 | return child_event; | |
9979 | } | |
9980 | ||
9981 | static int inherit_group(struct perf_event *parent_event, | |
9982 | struct task_struct *parent, | |
9983 | struct perf_event_context *parent_ctx, | |
9984 | struct task_struct *child, | |
9985 | struct perf_event_context *child_ctx) | |
9986 | { | |
9987 | struct perf_event *leader; | |
9988 | struct perf_event *sub; | |
9989 | struct perf_event *child_ctr; | |
9990 | ||
9991 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9992 | child, NULL, child_ctx); | |
9993 | if (IS_ERR(leader)) | |
9994 | return PTR_ERR(leader); | |
9995 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9996 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9997 | child, leader, child_ctx); | |
9998 | if (IS_ERR(child_ctr)) | |
9999 | return PTR_ERR(child_ctr); | |
10000 | } | |
10001 | return 0; | |
889ff015 FW |
10002 | } |
10003 | ||
10004 | static int | |
10005 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
10006 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 10007 | struct task_struct *child, int ctxn, |
889ff015 FW |
10008 | int *inherited_all) |
10009 | { | |
10010 | int ret; | |
8dc85d54 | 10011 | struct perf_event_context *child_ctx; |
889ff015 FW |
10012 | |
10013 | if (!event->attr.inherit) { | |
10014 | *inherited_all = 0; | |
10015 | return 0; | |
bbbee908 PZ |
10016 | } |
10017 | ||
fe4b04fa | 10018 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
10019 | if (!child_ctx) { |
10020 | /* | |
10021 | * This is executed from the parent task context, so | |
10022 | * inherit events that have been marked for cloning. | |
10023 | * First allocate and initialize a context for the | |
10024 | * child. | |
10025 | */ | |
bbbee908 | 10026 | |
734df5ab | 10027 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
10028 | if (!child_ctx) |
10029 | return -ENOMEM; | |
bbbee908 | 10030 | |
8dc85d54 | 10031 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
10032 | } |
10033 | ||
10034 | ret = inherit_group(event, parent, parent_ctx, | |
10035 | child, child_ctx); | |
10036 | ||
10037 | if (ret) | |
10038 | *inherited_all = 0; | |
10039 | ||
10040 | return ret; | |
bbbee908 PZ |
10041 | } |
10042 | ||
9b51f66d | 10043 | /* |
cdd6c482 | 10044 | * Initialize the perf_event context in task_struct |
9b51f66d | 10045 | */ |
985c8dcb | 10046 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 10047 | { |
889ff015 | 10048 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
10049 | struct perf_event_context *cloned_ctx; |
10050 | struct perf_event *event; | |
9b51f66d | 10051 | struct task_struct *parent = current; |
564c2b21 | 10052 | int inherited_all = 1; |
dddd3379 | 10053 | unsigned long flags; |
6ab423e0 | 10054 | int ret = 0; |
9b51f66d | 10055 | |
8dc85d54 | 10056 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
10057 | return 0; |
10058 | ||
ad3a37de | 10059 | /* |
25346b93 PM |
10060 | * If the parent's context is a clone, pin it so it won't get |
10061 | * swapped under us. | |
ad3a37de | 10062 | */ |
8dc85d54 | 10063 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
10064 | if (!parent_ctx) |
10065 | return 0; | |
25346b93 | 10066 | |
ad3a37de PM |
10067 | /* |
10068 | * No need to check if parent_ctx != NULL here; since we saw | |
10069 | * it non-NULL earlier, the only reason for it to become NULL | |
10070 | * is if we exit, and since we're currently in the middle of | |
10071 | * a fork we can't be exiting at the same time. | |
10072 | */ | |
ad3a37de | 10073 | |
9b51f66d IM |
10074 | /* |
10075 | * Lock the parent list. No need to lock the child - not PID | |
10076 | * hashed yet and not running, so nobody can access it. | |
10077 | */ | |
d859e29f | 10078 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
10079 | |
10080 | /* | |
10081 | * We dont have to disable NMIs - we are only looking at | |
10082 | * the list, not manipulating it: | |
10083 | */ | |
889ff015 | 10084 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
10085 | ret = inherit_task_group(event, parent, parent_ctx, |
10086 | child, ctxn, &inherited_all); | |
889ff015 FW |
10087 | if (ret) |
10088 | break; | |
10089 | } | |
b93f7978 | 10090 | |
dddd3379 TG |
10091 | /* |
10092 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
10093 | * to allocations, but we need to prevent rotation because | |
10094 | * rotate_ctx() will change the list from interrupt context. | |
10095 | */ | |
10096 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
10097 | parent_ctx->rotate_disable = 1; | |
10098 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
10099 | ||
889ff015 | 10100 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
10101 | ret = inherit_task_group(event, parent, parent_ctx, |
10102 | child, ctxn, &inherited_all); | |
889ff015 | 10103 | if (ret) |
9b51f66d | 10104 | break; |
564c2b21 PM |
10105 | } |
10106 | ||
dddd3379 TG |
10107 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
10108 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 10109 | |
8dc85d54 | 10110 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 10111 | |
05cbaa28 | 10112 | if (child_ctx && inherited_all) { |
564c2b21 PM |
10113 | /* |
10114 | * Mark the child context as a clone of the parent | |
10115 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
10116 | * |
10117 | * Note that if the parent is a clone, the holding of | |
10118 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 10119 | */ |
c5ed5145 | 10120 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
10121 | if (cloned_ctx) { |
10122 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 10123 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
10124 | } else { |
10125 | child_ctx->parent_ctx = parent_ctx; | |
10126 | child_ctx->parent_gen = parent_ctx->generation; | |
10127 | } | |
10128 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
10129 | } |
10130 | ||
c5ed5145 | 10131 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 10132 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 10133 | |
25346b93 | 10134 | perf_unpin_context(parent_ctx); |
fe4b04fa | 10135 | put_ctx(parent_ctx); |
ad3a37de | 10136 | |
6ab423e0 | 10137 | return ret; |
9b51f66d IM |
10138 | } |
10139 | ||
8dc85d54 PZ |
10140 | /* |
10141 | * Initialize the perf_event context in task_struct | |
10142 | */ | |
10143 | int perf_event_init_task(struct task_struct *child) | |
10144 | { | |
10145 | int ctxn, ret; | |
10146 | ||
8550d7cb ON |
10147 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
10148 | mutex_init(&child->perf_event_mutex); | |
10149 | INIT_LIST_HEAD(&child->perf_event_list); | |
10150 | ||
8dc85d54 PZ |
10151 | for_each_task_context_nr(ctxn) { |
10152 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
10153 | if (ret) { |
10154 | perf_event_free_task(child); | |
8dc85d54 | 10155 | return ret; |
6c72e350 | 10156 | } |
8dc85d54 PZ |
10157 | } |
10158 | ||
10159 | return 0; | |
10160 | } | |
10161 | ||
220b140b PM |
10162 | static void __init perf_event_init_all_cpus(void) |
10163 | { | |
b28ab83c | 10164 | struct swevent_htable *swhash; |
220b140b | 10165 | int cpu; |
220b140b PM |
10166 | |
10167 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
10168 | swhash = &per_cpu(swevent_htable, cpu); |
10169 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 10170 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
10171 | } |
10172 | } | |
10173 | ||
0db0628d | 10174 | static void perf_event_init_cpu(int cpu) |
0793a61d | 10175 | { |
108b02cf | 10176 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 10177 | |
b28ab83c | 10178 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 10179 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
10180 | struct swevent_hlist *hlist; |
10181 | ||
b28ab83c PZ |
10182 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
10183 | WARN_ON(!hlist); | |
10184 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 10185 | } |
b28ab83c | 10186 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
10187 | } |
10188 | ||
2965faa5 | 10189 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 10190 | static void __perf_event_exit_context(void *__info) |
0793a61d | 10191 | { |
108b02cf | 10192 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
10193 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
10194 | struct perf_event *event; | |
0793a61d | 10195 | |
fae3fde6 PZ |
10196 | raw_spin_lock(&ctx->lock); |
10197 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 10198 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 10199 | raw_spin_unlock(&ctx->lock); |
0793a61d | 10200 | } |
108b02cf PZ |
10201 | |
10202 | static void perf_event_exit_cpu_context(int cpu) | |
10203 | { | |
10204 | struct perf_event_context *ctx; | |
10205 | struct pmu *pmu; | |
10206 | int idx; | |
10207 | ||
10208 | idx = srcu_read_lock(&pmus_srcu); | |
10209 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 10210 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
10211 | |
10212 | mutex_lock(&ctx->mutex); | |
10213 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
10214 | mutex_unlock(&ctx->mutex); | |
10215 | } | |
10216 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
10217 | } |
10218 | ||
cdd6c482 | 10219 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 10220 | { |
e3703f8c | 10221 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
10222 | } |
10223 | #else | |
cdd6c482 | 10224 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
10225 | #endif |
10226 | ||
c277443c PZ |
10227 | static int |
10228 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
10229 | { | |
10230 | int cpu; | |
10231 | ||
10232 | for_each_online_cpu(cpu) | |
10233 | perf_event_exit_cpu(cpu); | |
10234 | ||
10235 | return NOTIFY_OK; | |
10236 | } | |
10237 | ||
10238 | /* | |
10239 | * Run the perf reboot notifier at the very last possible moment so that | |
10240 | * the generic watchdog code runs as long as possible. | |
10241 | */ | |
10242 | static struct notifier_block perf_reboot_notifier = { | |
10243 | .notifier_call = perf_reboot, | |
10244 | .priority = INT_MIN, | |
10245 | }; | |
10246 | ||
0db0628d | 10247 | static int |
0793a61d TG |
10248 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
10249 | { | |
10250 | unsigned int cpu = (long)hcpu; | |
10251 | ||
4536e4d1 | 10252 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
10253 | |
10254 | case CPU_UP_PREPARE: | |
1dcaac1c PZ |
10255 | /* |
10256 | * This must be done before the CPU comes alive, because the | |
10257 | * moment we can run tasks we can encounter (software) events. | |
10258 | * | |
10259 | * Specifically, someone can have inherited events on kthreadd | |
10260 | * or a pre-existing worker thread that gets re-bound. | |
10261 | */ | |
cdd6c482 | 10262 | perf_event_init_cpu(cpu); |
0793a61d TG |
10263 | break; |
10264 | ||
10265 | case CPU_DOWN_PREPARE: | |
1dcaac1c PZ |
10266 | /* |
10267 | * This must be done before the CPU dies because after that an | |
10268 | * active event might want to IPI the CPU and that'll not work | |
10269 | * so great for dead CPUs. | |
10270 | * | |
10271 | * XXX smp_call_function_single() return -ENXIO without a warn | |
10272 | * so we could possibly deal with this. | |
10273 | * | |
10274 | * This is safe against new events arriving because | |
10275 | * sys_perf_event_open() serializes against hotplug using | |
10276 | * get_online_cpus(). | |
10277 | */ | |
cdd6c482 | 10278 | perf_event_exit_cpu(cpu); |
0793a61d | 10279 | break; |
0793a61d TG |
10280 | default: |
10281 | break; | |
10282 | } | |
10283 | ||
10284 | return NOTIFY_OK; | |
10285 | } | |
10286 | ||
cdd6c482 | 10287 | void __init perf_event_init(void) |
0793a61d | 10288 | { |
3c502e7a JW |
10289 | int ret; |
10290 | ||
2e80a82a PZ |
10291 | idr_init(&pmu_idr); |
10292 | ||
220b140b | 10293 | perf_event_init_all_cpus(); |
b0a873eb | 10294 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
10295 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
10296 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
10297 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
10298 | perf_tp_register(); |
10299 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 10300 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
10301 | |
10302 | ret = init_hw_breakpoint(); | |
10303 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 10304 | |
b01c3a00 JO |
10305 | /* |
10306 | * Build time assertion that we keep the data_head at the intended | |
10307 | * location. IOW, validation we got the __reserved[] size right. | |
10308 | */ | |
10309 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
10310 | != 1024); | |
0793a61d | 10311 | } |
abe43400 | 10312 | |
fd979c01 CS |
10313 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
10314 | char *page) | |
10315 | { | |
10316 | struct perf_pmu_events_attr *pmu_attr = | |
10317 | container_of(attr, struct perf_pmu_events_attr, attr); | |
10318 | ||
10319 | if (pmu_attr->event_str) | |
10320 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
10321 | ||
10322 | return 0; | |
10323 | } | |
675965b0 | 10324 | EXPORT_SYMBOL_GPL(perf_event_sysfs_show); |
fd979c01 | 10325 | |
abe43400 PZ |
10326 | static int __init perf_event_sysfs_init(void) |
10327 | { | |
10328 | struct pmu *pmu; | |
10329 | int ret; | |
10330 | ||
10331 | mutex_lock(&pmus_lock); | |
10332 | ||
10333 | ret = bus_register(&pmu_bus); | |
10334 | if (ret) | |
10335 | goto unlock; | |
10336 | ||
10337 | list_for_each_entry(pmu, &pmus, entry) { | |
10338 | if (!pmu->name || pmu->type < 0) | |
10339 | continue; | |
10340 | ||
10341 | ret = pmu_dev_alloc(pmu); | |
10342 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
10343 | } | |
10344 | pmu_bus_running = 1; | |
10345 | ret = 0; | |
10346 | ||
10347 | unlock: | |
10348 | mutex_unlock(&pmus_lock); | |
10349 | ||
10350 | return ret; | |
10351 | } | |
10352 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
10353 | |
10354 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
10355 | static struct cgroup_subsys_state * |
10356 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
10357 | { |
10358 | struct perf_cgroup *jc; | |
e5d1367f | 10359 | |
1b15d055 | 10360 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
10361 | if (!jc) |
10362 | return ERR_PTR(-ENOMEM); | |
10363 | ||
e5d1367f SE |
10364 | jc->info = alloc_percpu(struct perf_cgroup_info); |
10365 | if (!jc->info) { | |
10366 | kfree(jc); | |
10367 | return ERR_PTR(-ENOMEM); | |
10368 | } | |
10369 | ||
e5d1367f SE |
10370 | return &jc->css; |
10371 | } | |
10372 | ||
eb95419b | 10373 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 10374 | { |
eb95419b TH |
10375 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
10376 | ||
e5d1367f SE |
10377 | free_percpu(jc->info); |
10378 | kfree(jc); | |
10379 | } | |
10380 | ||
10381 | static int __perf_cgroup_move(void *info) | |
10382 | { | |
10383 | struct task_struct *task = info; | |
ddaaf4e2 | 10384 | rcu_read_lock(); |
e5d1367f | 10385 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 10386 | rcu_read_unlock(); |
e5d1367f SE |
10387 | return 0; |
10388 | } | |
10389 | ||
1f7dd3e5 | 10390 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 10391 | { |
bb9d97b6 | 10392 | struct task_struct *task; |
1f7dd3e5 | 10393 | struct cgroup_subsys_state *css; |
bb9d97b6 | 10394 | |
1f7dd3e5 | 10395 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 10396 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
10397 | } |
10398 | ||
073219e9 | 10399 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
10400 | .css_alloc = perf_cgroup_css_alloc, |
10401 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 10402 | .attach = perf_cgroup_attach, |
e5d1367f SE |
10403 | }; |
10404 | #endif /* CONFIG_CGROUP_PERF */ |