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> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
272325c4 PZ |
52 | typedef int (*remote_function_f)(void *); |
53 | ||
fe4b04fa | 54 | struct remote_function_call { |
e7e7ee2e | 55 | struct task_struct *p; |
272325c4 | 56 | remote_function_f func; |
e7e7ee2e IM |
57 | void *info; |
58 | int ret; | |
fe4b04fa PZ |
59 | }; |
60 | ||
61 | static void remote_function(void *data) | |
62 | { | |
63 | struct remote_function_call *tfc = data; | |
64 | struct task_struct *p = tfc->p; | |
65 | ||
66 | if (p) { | |
0da4cf3e PZ |
67 | /* -EAGAIN */ |
68 | if (task_cpu(p) != smp_processor_id()) | |
69 | return; | |
70 | ||
71 | /* | |
72 | * Now that we're on right CPU with IRQs disabled, we can test | |
73 | * if we hit the right task without races. | |
74 | */ | |
75 | ||
76 | tfc->ret = -ESRCH; /* No such (running) process */ | |
77 | if (p != current) | |
fe4b04fa PZ |
78 | return; |
79 | } | |
80 | ||
81 | tfc->ret = tfc->func(tfc->info); | |
82 | } | |
83 | ||
84 | /** | |
85 | * task_function_call - call a function on the cpu on which a task runs | |
86 | * @p: the task to evaluate | |
87 | * @func: the function to be called | |
88 | * @info: the function call argument | |
89 | * | |
90 | * Calls the function @func when the task is currently running. This might | |
91 | * be on the current CPU, which just calls the function directly | |
92 | * | |
93 | * returns: @func return value, or | |
94 | * -ESRCH - when the process isn't running | |
95 | * -EAGAIN - when the process moved away | |
96 | */ | |
97 | static int | |
272325c4 | 98 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
99 | { |
100 | struct remote_function_call data = { | |
e7e7ee2e IM |
101 | .p = p, |
102 | .func = func, | |
103 | .info = info, | |
0da4cf3e | 104 | .ret = -EAGAIN, |
fe4b04fa | 105 | }; |
0da4cf3e | 106 | int ret; |
fe4b04fa | 107 | |
0da4cf3e PZ |
108 | do { |
109 | ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
110 | if (!ret) | |
111 | ret = data.ret; | |
112 | } while (ret == -EAGAIN); | |
fe4b04fa | 113 | |
0da4cf3e | 114 | return ret; |
fe4b04fa PZ |
115 | } |
116 | ||
117 | /** | |
118 | * cpu_function_call - call a function on the cpu | |
119 | * @func: the function to be called | |
120 | * @info: the function call argument | |
121 | * | |
122 | * Calls the function @func on the remote cpu. | |
123 | * | |
124 | * returns: @func return value or -ENXIO when the cpu is offline | |
125 | */ | |
272325c4 | 126 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
127 | { |
128 | struct remote_function_call data = { | |
e7e7ee2e IM |
129 | .p = NULL, |
130 | .func = func, | |
131 | .info = info, | |
132 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
133 | }; |
134 | ||
135 | smp_call_function_single(cpu, remote_function, &data, 1); | |
136 | ||
137 | return data.ret; | |
138 | } | |
139 | ||
fae3fde6 PZ |
140 | static inline struct perf_cpu_context * |
141 | __get_cpu_context(struct perf_event_context *ctx) | |
142 | { | |
143 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
144 | } | |
145 | ||
146 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
147 | struct perf_event_context *ctx) | |
0017960f | 148 | { |
fae3fde6 PZ |
149 | raw_spin_lock(&cpuctx->ctx.lock); |
150 | if (ctx) | |
151 | raw_spin_lock(&ctx->lock); | |
152 | } | |
153 | ||
154 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
155 | struct perf_event_context *ctx) | |
156 | { | |
157 | if (ctx) | |
158 | raw_spin_unlock(&ctx->lock); | |
159 | raw_spin_unlock(&cpuctx->ctx.lock); | |
160 | } | |
161 | ||
63b6da39 PZ |
162 | #define TASK_TOMBSTONE ((void *)-1L) |
163 | ||
164 | static bool is_kernel_event(struct perf_event *event) | |
165 | { | |
f47c02c0 | 166 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
167 | } |
168 | ||
39a43640 PZ |
169 | /* |
170 | * On task ctx scheduling... | |
171 | * | |
172 | * When !ctx->nr_events a task context will not be scheduled. This means | |
173 | * we can disable the scheduler hooks (for performance) without leaving | |
174 | * pending task ctx state. | |
175 | * | |
176 | * This however results in two special cases: | |
177 | * | |
178 | * - removing the last event from a task ctx; this is relatively straight | |
179 | * forward and is done in __perf_remove_from_context. | |
180 | * | |
181 | * - adding the first event to a task ctx; this is tricky because we cannot | |
182 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
183 | * See perf_install_in_context(). | |
184 | * | |
39a43640 PZ |
185 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. |
186 | */ | |
187 | ||
fae3fde6 PZ |
188 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
189 | struct perf_event_context *, void *); | |
190 | ||
191 | struct event_function_struct { | |
192 | struct perf_event *event; | |
193 | event_f func; | |
194 | void *data; | |
195 | }; | |
196 | ||
197 | static int event_function(void *info) | |
198 | { | |
199 | struct event_function_struct *efs = info; | |
200 | struct perf_event *event = efs->event; | |
0017960f | 201 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
202 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
203 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 204 | int ret = 0; |
fae3fde6 PZ |
205 | |
206 | WARN_ON_ONCE(!irqs_disabled()); | |
207 | ||
63b6da39 | 208 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
209 | /* |
210 | * Since we do the IPI call without holding ctx->lock things can have | |
211 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
212 | */ |
213 | if (ctx->task) { | |
63b6da39 | 214 | if (ctx->task != current) { |
0da4cf3e | 215 | ret = -ESRCH; |
63b6da39 PZ |
216 | goto unlock; |
217 | } | |
fae3fde6 | 218 | |
fae3fde6 PZ |
219 | /* |
220 | * We only use event_function_call() on established contexts, | |
221 | * and event_function() is only ever called when active (or | |
222 | * rather, we'll have bailed in task_function_call() or the | |
223 | * above ctx->task != current test), therefore we must have | |
224 | * ctx->is_active here. | |
225 | */ | |
226 | WARN_ON_ONCE(!ctx->is_active); | |
227 | /* | |
228 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
229 | * match. | |
230 | */ | |
63b6da39 PZ |
231 | WARN_ON_ONCE(task_ctx != ctx); |
232 | } else { | |
233 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 234 | } |
63b6da39 | 235 | |
fae3fde6 | 236 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 237 | unlock: |
fae3fde6 PZ |
238 | perf_ctx_unlock(cpuctx, task_ctx); |
239 | ||
63b6da39 | 240 | return ret; |
fae3fde6 PZ |
241 | } |
242 | ||
243 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
244 | { | |
245 | struct event_function_struct efs = { | |
246 | .event = event, | |
247 | .func = func, | |
248 | .data = data, | |
249 | }; | |
250 | ||
251 | int ret = event_function(&efs); | |
252 | WARN_ON_ONCE(ret); | |
253 | } | |
254 | ||
255 | static void event_function_call(struct perf_event *event, event_f func, void *data) | |
0017960f PZ |
256 | { |
257 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 258 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
259 | struct event_function_struct efs = { |
260 | .event = event, | |
261 | .func = func, | |
262 | .data = data, | |
263 | }; | |
0017960f | 264 | |
c97f4736 PZ |
265 | if (!event->parent) { |
266 | /* | |
267 | * If this is a !child event, we must hold ctx::mutex to | |
268 | * stabilize the the event->ctx relation. See | |
269 | * perf_event_ctx_lock(). | |
270 | */ | |
271 | lockdep_assert_held(&ctx->mutex); | |
272 | } | |
0017960f PZ |
273 | |
274 | if (!task) { | |
fae3fde6 | 275 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
276 | return; |
277 | } | |
278 | ||
63b6da39 PZ |
279 | if (task == TASK_TOMBSTONE) |
280 | return; | |
281 | ||
a096309b | 282 | again: |
fae3fde6 | 283 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
284 | return; |
285 | ||
286 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
287 | /* |
288 | * Reload the task pointer, it might have been changed by | |
289 | * a concurrent perf_event_context_sched_out(). | |
290 | */ | |
291 | task = ctx->task; | |
a096309b PZ |
292 | if (task == TASK_TOMBSTONE) { |
293 | raw_spin_unlock_irq(&ctx->lock); | |
294 | return; | |
0017960f | 295 | } |
a096309b PZ |
296 | if (ctx->is_active) { |
297 | raw_spin_unlock_irq(&ctx->lock); | |
298 | goto again; | |
299 | } | |
300 | func(event, NULL, ctx, data); | |
0017960f PZ |
301 | raw_spin_unlock_irq(&ctx->lock); |
302 | } | |
303 | ||
e5d1367f SE |
304 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
305 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
306 | PERF_FLAG_PID_CGROUP |\ |
307 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 308 | |
bce38cd5 SE |
309 | /* |
310 | * branch priv levels that need permission checks | |
311 | */ | |
312 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
313 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
314 | PERF_SAMPLE_BRANCH_HV) | |
315 | ||
0b3fcf17 SE |
316 | enum event_type_t { |
317 | EVENT_FLEXIBLE = 0x1, | |
318 | EVENT_PINNED = 0x2, | |
3cbaa590 | 319 | EVENT_TIME = 0x4, |
0b3fcf17 SE |
320 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
321 | }; | |
322 | ||
e5d1367f SE |
323 | /* |
324 | * perf_sched_events : >0 events exist | |
325 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
326 | */ | |
9107c89e PZ |
327 | |
328 | static void perf_sched_delayed(struct work_struct *work); | |
329 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
330 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
331 | static DEFINE_MUTEX(perf_sched_mutex); | |
332 | static atomic_t perf_sched_count; | |
333 | ||
e5d1367f | 334 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 335 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 336 | |
cdd6c482 IM |
337 | static atomic_t nr_mmap_events __read_mostly; |
338 | static atomic_t nr_comm_events __read_mostly; | |
339 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 340 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 341 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 342 | |
108b02cf PZ |
343 | static LIST_HEAD(pmus); |
344 | static DEFINE_MUTEX(pmus_lock); | |
345 | static struct srcu_struct pmus_srcu; | |
346 | ||
0764771d | 347 | /* |
cdd6c482 | 348 | * perf event paranoia level: |
0fbdea19 IM |
349 | * -1 - not paranoid at all |
350 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 351 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 352 | * 2 - disallow kernel profiling for unpriv |
0764771d | 353 | */ |
cdd6c482 | 354 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 355 | |
20443384 FW |
356 | /* Minimum for 512 kiB + 1 user control page */ |
357 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
358 | |
359 | /* | |
cdd6c482 | 360 | * max perf event sample rate |
df58ab24 | 361 | */ |
14c63f17 DH |
362 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
363 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
364 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
365 | ||
366 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
367 | ||
368 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
369 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
370 | ||
d9494cb4 PZ |
371 | static int perf_sample_allowed_ns __read_mostly = |
372 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 373 | |
18ab2cd3 | 374 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
375 | { |
376 | u64 tmp = perf_sample_period_ns; | |
377 | ||
378 | tmp *= sysctl_perf_cpu_time_max_percent; | |
91a612ee PZ |
379 | tmp = div_u64(tmp, 100); |
380 | if (!tmp) | |
381 | tmp = 1; | |
382 | ||
383 | WRITE_ONCE(perf_sample_allowed_ns, tmp); | |
14c63f17 | 384 | } |
163ec435 | 385 | |
9e630205 SE |
386 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
387 | ||
163ec435 PZ |
388 | int perf_proc_update_handler(struct ctl_table *table, int write, |
389 | void __user *buffer, size_t *lenp, | |
390 | loff_t *ppos) | |
391 | { | |
723478c8 | 392 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
393 | |
394 | if (ret || !write) | |
395 | return ret; | |
396 | ||
397 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
398 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
399 | update_perf_cpu_limits(); | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
404 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
405 | ||
406 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
407 | void __user *buffer, size_t *lenp, | |
408 | loff_t *ppos) | |
409 | { | |
410 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
411 | ||
412 | if (ret || !write) | |
413 | return ret; | |
414 | ||
91a612ee PZ |
415 | if (sysctl_perf_cpu_time_max_percent == 100) { |
416 | printk(KERN_WARNING | |
417 | "perf: Dynamic interrupt throttling disabled, can hang your system!\n"); | |
418 | WRITE_ONCE(perf_sample_allowed_ns, 0); | |
419 | } else { | |
420 | update_perf_cpu_limits(); | |
421 | } | |
163ec435 PZ |
422 | |
423 | return 0; | |
424 | } | |
1ccd1549 | 425 | |
14c63f17 DH |
426 | /* |
427 | * perf samples are done in some very critical code paths (NMIs). | |
428 | * If they take too much CPU time, the system can lock up and not | |
429 | * get any real work done. This will drop the sample rate when | |
430 | * we detect that events are taking too long. | |
431 | */ | |
432 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 433 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 434 | |
91a612ee PZ |
435 | static u64 __report_avg; |
436 | static u64 __report_allowed; | |
437 | ||
6a02ad66 | 438 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 439 | { |
6a02ad66 | 440 | printk_ratelimited(KERN_WARNING |
91a612ee PZ |
441 | "perf: interrupt took too long (%lld > %lld), lowering " |
442 | "kernel.perf_event_max_sample_rate to %d\n", | |
443 | __report_avg, __report_allowed, | |
444 | sysctl_perf_event_sample_rate); | |
6a02ad66 PZ |
445 | } |
446 | ||
447 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
448 | ||
449 | void perf_sample_event_took(u64 sample_len_ns) | |
450 | { | |
91a612ee PZ |
451 | u64 max_len = READ_ONCE(perf_sample_allowed_ns); |
452 | u64 running_len; | |
453 | u64 avg_len; | |
454 | u32 max; | |
14c63f17 | 455 | |
91a612ee | 456 | if (max_len == 0) |
14c63f17 DH |
457 | return; |
458 | ||
91a612ee PZ |
459 | /* Decay the counter by 1 average sample. */ |
460 | running_len = __this_cpu_read(running_sample_length); | |
461 | running_len -= running_len/NR_ACCUMULATED_SAMPLES; | |
462 | running_len += sample_len_ns; | |
463 | __this_cpu_write(running_sample_length, running_len); | |
14c63f17 DH |
464 | |
465 | /* | |
91a612ee PZ |
466 | * Note: this will be biased artifically low until we have |
467 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
14c63f17 DH |
468 | * from having to maintain a count. |
469 | */ | |
91a612ee PZ |
470 | avg_len = running_len/NR_ACCUMULATED_SAMPLES; |
471 | if (avg_len <= max_len) | |
14c63f17 DH |
472 | return; |
473 | ||
91a612ee PZ |
474 | __report_avg = avg_len; |
475 | __report_allowed = max_len; | |
14c63f17 | 476 | |
91a612ee PZ |
477 | /* |
478 | * Compute a throttle threshold 25% below the current duration. | |
479 | */ | |
480 | avg_len += avg_len / 4; | |
481 | max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent; | |
482 | if (avg_len < max) | |
483 | max /= (u32)avg_len; | |
484 | else | |
485 | max = 1; | |
14c63f17 | 486 | |
91a612ee PZ |
487 | WRITE_ONCE(perf_sample_allowed_ns, avg_len); |
488 | WRITE_ONCE(max_samples_per_tick, max); | |
489 | ||
490 | sysctl_perf_event_sample_rate = max * HZ; | |
491 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
6a02ad66 | 492 | |
cd578abb | 493 | if (!irq_work_queue(&perf_duration_work)) { |
91a612ee | 494 | early_printk("perf: interrupt took too long (%lld > %lld), lowering " |
cd578abb | 495 | "kernel.perf_event_max_sample_rate to %d\n", |
91a612ee | 496 | __report_avg, __report_allowed, |
cd578abb PZ |
497 | sysctl_perf_event_sample_rate); |
498 | } | |
14c63f17 DH |
499 | } |
500 | ||
cdd6c482 | 501 | static atomic64_t perf_event_id; |
a96bbc16 | 502 | |
0b3fcf17 SE |
503 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
504 | enum event_type_t event_type); | |
505 | ||
506 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
507 | enum event_type_t event_type, |
508 | struct task_struct *task); | |
509 | ||
510 | static void update_context_time(struct perf_event_context *ctx); | |
511 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 512 | |
cdd6c482 | 513 | void __weak perf_event_print_debug(void) { } |
0793a61d | 514 | |
84c79910 | 515 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 516 | { |
84c79910 | 517 | return "pmu"; |
0793a61d TG |
518 | } |
519 | ||
0b3fcf17 SE |
520 | static inline u64 perf_clock(void) |
521 | { | |
522 | return local_clock(); | |
523 | } | |
524 | ||
34f43927 PZ |
525 | static inline u64 perf_event_clock(struct perf_event *event) |
526 | { | |
527 | return event->clock(); | |
528 | } | |
529 | ||
e5d1367f SE |
530 | #ifdef CONFIG_CGROUP_PERF |
531 | ||
e5d1367f SE |
532 | static inline bool |
533 | perf_cgroup_match(struct perf_event *event) | |
534 | { | |
535 | struct perf_event_context *ctx = event->ctx; | |
536 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
537 | ||
ef824fa1 TH |
538 | /* @event doesn't care about cgroup */ |
539 | if (!event->cgrp) | |
540 | return true; | |
541 | ||
542 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
543 | if (!cpuctx->cgrp) | |
544 | return false; | |
545 | ||
546 | /* | |
547 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
548 | * also enabled for all its descendant cgroups. If @cpuctx's | |
549 | * cgroup is a descendant of @event's (the test covers identity | |
550 | * case), it's a match. | |
551 | */ | |
552 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
553 | event->cgrp->css.cgroup); | |
e5d1367f SE |
554 | } |
555 | ||
e5d1367f SE |
556 | static inline void perf_detach_cgroup(struct perf_event *event) |
557 | { | |
4e2ba650 | 558 | css_put(&event->cgrp->css); |
e5d1367f SE |
559 | event->cgrp = NULL; |
560 | } | |
561 | ||
562 | static inline int is_cgroup_event(struct perf_event *event) | |
563 | { | |
564 | return event->cgrp != NULL; | |
565 | } | |
566 | ||
567 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
568 | { | |
569 | struct perf_cgroup_info *t; | |
570 | ||
571 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
572 | return t->time; | |
573 | } | |
574 | ||
575 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
576 | { | |
577 | struct perf_cgroup_info *info; | |
578 | u64 now; | |
579 | ||
580 | now = perf_clock(); | |
581 | ||
582 | info = this_cpu_ptr(cgrp->info); | |
583 | ||
584 | info->time += now - info->timestamp; | |
585 | info->timestamp = now; | |
586 | } | |
587 | ||
588 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
589 | { | |
590 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
591 | if (cgrp_out) | |
592 | __update_cgrp_time(cgrp_out); | |
593 | } | |
594 | ||
595 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
596 | { | |
3f7cce3c SE |
597 | struct perf_cgroup *cgrp; |
598 | ||
e5d1367f | 599 | /* |
3f7cce3c SE |
600 | * ensure we access cgroup data only when needed and |
601 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 602 | */ |
3f7cce3c | 603 | if (!is_cgroup_event(event)) |
e5d1367f SE |
604 | return; |
605 | ||
614e4c4e | 606 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
607 | /* |
608 | * Do not update time when cgroup is not active | |
609 | */ | |
610 | if (cgrp == event->cgrp) | |
611 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
612 | } |
613 | ||
614 | static inline void | |
3f7cce3c SE |
615 | perf_cgroup_set_timestamp(struct task_struct *task, |
616 | struct perf_event_context *ctx) | |
e5d1367f SE |
617 | { |
618 | struct perf_cgroup *cgrp; | |
619 | struct perf_cgroup_info *info; | |
620 | ||
3f7cce3c SE |
621 | /* |
622 | * ctx->lock held by caller | |
623 | * ensure we do not access cgroup data | |
624 | * unless we have the cgroup pinned (css_get) | |
625 | */ | |
626 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
627 | return; |
628 | ||
614e4c4e | 629 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 630 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 631 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
632 | } |
633 | ||
634 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
635 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
636 | ||
637 | /* | |
638 | * reschedule events based on the cgroup constraint of task. | |
639 | * | |
640 | * mode SWOUT : schedule out everything | |
641 | * mode SWIN : schedule in based on cgroup for next | |
642 | */ | |
18ab2cd3 | 643 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
644 | { |
645 | struct perf_cpu_context *cpuctx; | |
646 | struct pmu *pmu; | |
647 | unsigned long flags; | |
648 | ||
649 | /* | |
650 | * disable interrupts to avoid geting nr_cgroup | |
651 | * changes via __perf_event_disable(). Also | |
652 | * avoids preemption. | |
653 | */ | |
654 | local_irq_save(flags); | |
655 | ||
656 | /* | |
657 | * we reschedule only in the presence of cgroup | |
658 | * constrained events. | |
659 | */ | |
e5d1367f SE |
660 | |
661 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 662 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
663 | if (cpuctx->unique_pmu != pmu) |
664 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 665 | |
e5d1367f SE |
666 | /* |
667 | * perf_cgroup_events says at least one | |
668 | * context on this CPU has cgroup events. | |
669 | * | |
670 | * ctx->nr_cgroups reports the number of cgroup | |
671 | * events for a context. | |
672 | */ | |
673 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
674 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
675 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
676 | |
677 | if (mode & PERF_CGROUP_SWOUT) { | |
678 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
679 | /* | |
680 | * must not be done before ctxswout due | |
681 | * to event_filter_match() in event_sched_out() | |
682 | */ | |
683 | cpuctx->cgrp = NULL; | |
684 | } | |
685 | ||
686 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 687 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
688 | /* |
689 | * set cgrp before ctxsw in to allow | |
690 | * event_filter_match() to not have to pass | |
691 | * task around | |
614e4c4e SE |
692 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
693 | * because cgorup events are only per-cpu | |
e5d1367f | 694 | */ |
614e4c4e | 695 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
696 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
697 | } | |
facc4307 PZ |
698 | perf_pmu_enable(cpuctx->ctx.pmu); |
699 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 700 | } |
e5d1367f SE |
701 | } |
702 | ||
e5d1367f SE |
703 | local_irq_restore(flags); |
704 | } | |
705 | ||
a8d757ef SE |
706 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
707 | struct task_struct *next) | |
e5d1367f | 708 | { |
a8d757ef SE |
709 | struct perf_cgroup *cgrp1; |
710 | struct perf_cgroup *cgrp2 = NULL; | |
711 | ||
ddaaf4e2 | 712 | rcu_read_lock(); |
a8d757ef SE |
713 | /* |
714 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
715 | * we do not need to pass the ctx here because we know |
716 | * we are holding the rcu lock | |
a8d757ef | 717 | */ |
614e4c4e | 718 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 719 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
720 | |
721 | /* | |
722 | * only schedule out current cgroup events if we know | |
723 | * that we are switching to a different cgroup. Otherwise, | |
724 | * do no touch the cgroup events. | |
725 | */ | |
726 | if (cgrp1 != cgrp2) | |
727 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
728 | |
729 | rcu_read_unlock(); | |
e5d1367f SE |
730 | } |
731 | ||
a8d757ef SE |
732 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
733 | struct task_struct *task) | |
e5d1367f | 734 | { |
a8d757ef SE |
735 | struct perf_cgroup *cgrp1; |
736 | struct perf_cgroup *cgrp2 = NULL; | |
737 | ||
ddaaf4e2 | 738 | rcu_read_lock(); |
a8d757ef SE |
739 | /* |
740 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
741 | * we do not need to pass the ctx here because we know |
742 | * we are holding the rcu lock | |
a8d757ef | 743 | */ |
614e4c4e | 744 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 745 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
746 | |
747 | /* | |
748 | * only need to schedule in cgroup events if we are changing | |
749 | * cgroup during ctxsw. Cgroup events were not scheduled | |
750 | * out of ctxsw out if that was not the case. | |
751 | */ | |
752 | if (cgrp1 != cgrp2) | |
753 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
754 | |
755 | rcu_read_unlock(); | |
e5d1367f SE |
756 | } |
757 | ||
758 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
759 | struct perf_event_attr *attr, | |
760 | struct perf_event *group_leader) | |
761 | { | |
762 | struct perf_cgroup *cgrp; | |
763 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
764 | struct fd f = fdget(fd); |
765 | int ret = 0; | |
e5d1367f | 766 | |
2903ff01 | 767 | if (!f.file) |
e5d1367f SE |
768 | return -EBADF; |
769 | ||
b583043e | 770 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 771 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
772 | if (IS_ERR(css)) { |
773 | ret = PTR_ERR(css); | |
774 | goto out; | |
775 | } | |
e5d1367f SE |
776 | |
777 | cgrp = container_of(css, struct perf_cgroup, css); | |
778 | event->cgrp = cgrp; | |
779 | ||
780 | /* | |
781 | * all events in a group must monitor | |
782 | * the same cgroup because a task belongs | |
783 | * to only one perf cgroup at a time | |
784 | */ | |
785 | if (group_leader && group_leader->cgrp != cgrp) { | |
786 | perf_detach_cgroup(event); | |
787 | ret = -EINVAL; | |
e5d1367f | 788 | } |
3db272c0 | 789 | out: |
2903ff01 | 790 | fdput(f); |
e5d1367f SE |
791 | return ret; |
792 | } | |
793 | ||
794 | static inline void | |
795 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
796 | { | |
797 | struct perf_cgroup_info *t; | |
798 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
799 | event->shadow_ctx_time = now - t->timestamp; | |
800 | } | |
801 | ||
802 | static inline void | |
803 | perf_cgroup_defer_enabled(struct perf_event *event) | |
804 | { | |
805 | /* | |
806 | * when the current task's perf cgroup does not match | |
807 | * the event's, we need to remember to call the | |
808 | * perf_mark_enable() function the first time a task with | |
809 | * a matching perf cgroup is scheduled in. | |
810 | */ | |
811 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
812 | event->cgrp_defer_enabled = 1; | |
813 | } | |
814 | ||
815 | static inline void | |
816 | perf_cgroup_mark_enabled(struct perf_event *event, | |
817 | struct perf_event_context *ctx) | |
818 | { | |
819 | struct perf_event *sub; | |
820 | u64 tstamp = perf_event_time(event); | |
821 | ||
822 | if (!event->cgrp_defer_enabled) | |
823 | return; | |
824 | ||
825 | event->cgrp_defer_enabled = 0; | |
826 | ||
827 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
828 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
829 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
830 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
831 | sub->cgrp_defer_enabled = 0; | |
832 | } | |
833 | } | |
834 | } | |
835 | #else /* !CONFIG_CGROUP_PERF */ | |
836 | ||
837 | static inline bool | |
838 | perf_cgroup_match(struct perf_event *event) | |
839 | { | |
840 | return true; | |
841 | } | |
842 | ||
843 | static inline void perf_detach_cgroup(struct perf_event *event) | |
844 | {} | |
845 | ||
846 | static inline int is_cgroup_event(struct perf_event *event) | |
847 | { | |
848 | return 0; | |
849 | } | |
850 | ||
851 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
852 | { | |
853 | return 0; | |
854 | } | |
855 | ||
856 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
857 | { | |
858 | } | |
859 | ||
860 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
861 | { | |
862 | } | |
863 | ||
a8d757ef SE |
864 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
865 | struct task_struct *next) | |
e5d1367f SE |
866 | { |
867 | } | |
868 | ||
a8d757ef SE |
869 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
870 | struct task_struct *task) | |
e5d1367f SE |
871 | { |
872 | } | |
873 | ||
874 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
875 | struct perf_event_attr *attr, | |
876 | struct perf_event *group_leader) | |
877 | { | |
878 | return -EINVAL; | |
879 | } | |
880 | ||
881 | static inline void | |
3f7cce3c SE |
882 | perf_cgroup_set_timestamp(struct task_struct *task, |
883 | struct perf_event_context *ctx) | |
e5d1367f SE |
884 | { |
885 | } | |
886 | ||
887 | void | |
888 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
889 | { | |
890 | } | |
891 | ||
892 | static inline void | |
893 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
894 | { | |
895 | } | |
896 | ||
897 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
898 | { | |
899 | return 0; | |
900 | } | |
901 | ||
902 | static inline void | |
903 | perf_cgroup_defer_enabled(struct perf_event *event) | |
904 | { | |
905 | } | |
906 | ||
907 | static inline void | |
908 | perf_cgroup_mark_enabled(struct perf_event *event, | |
909 | struct perf_event_context *ctx) | |
910 | { | |
911 | } | |
912 | #endif | |
913 | ||
9e630205 SE |
914 | /* |
915 | * set default to be dependent on timer tick just | |
916 | * like original code | |
917 | */ | |
918 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
919 | /* | |
920 | * function must be called with interrupts disbled | |
921 | */ | |
272325c4 | 922 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
923 | { |
924 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
925 | int rotations = 0; |
926 | ||
927 | WARN_ON(!irqs_disabled()); | |
928 | ||
929 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
930 | rotations = perf_rotate_context(cpuctx); |
931 | ||
4cfafd30 PZ |
932 | raw_spin_lock(&cpuctx->hrtimer_lock); |
933 | if (rotations) | |
9e630205 | 934 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
935 | else |
936 | cpuctx->hrtimer_active = 0; | |
937 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 938 | |
4cfafd30 | 939 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
940 | } |
941 | ||
272325c4 | 942 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 943 | { |
272325c4 | 944 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 945 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 946 | u64 interval; |
9e630205 SE |
947 | |
948 | /* no multiplexing needed for SW PMU */ | |
949 | if (pmu->task_ctx_nr == perf_sw_context) | |
950 | return; | |
951 | ||
62b85639 SE |
952 | /* |
953 | * check default is sane, if not set then force to | |
954 | * default interval (1/tick) | |
955 | */ | |
272325c4 PZ |
956 | interval = pmu->hrtimer_interval_ms; |
957 | if (interval < 1) | |
958 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 959 | |
272325c4 | 960 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 961 | |
4cfafd30 PZ |
962 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
963 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 964 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
965 | } |
966 | ||
272325c4 | 967 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 968 | { |
272325c4 | 969 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 970 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 971 | unsigned long flags; |
9e630205 SE |
972 | |
973 | /* not for SW PMU */ | |
974 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 975 | return 0; |
9e630205 | 976 | |
4cfafd30 PZ |
977 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
978 | if (!cpuctx->hrtimer_active) { | |
979 | cpuctx->hrtimer_active = 1; | |
980 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
981 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
982 | } | |
983 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 984 | |
272325c4 | 985 | return 0; |
9e630205 SE |
986 | } |
987 | ||
33696fc0 | 988 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 989 | { |
33696fc0 PZ |
990 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
991 | if (!(*count)++) | |
992 | pmu->pmu_disable(pmu); | |
9e35ad38 | 993 | } |
9e35ad38 | 994 | |
33696fc0 | 995 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 996 | { |
33696fc0 PZ |
997 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
998 | if (!--(*count)) | |
999 | pmu->pmu_enable(pmu); | |
9e35ad38 | 1000 | } |
9e35ad38 | 1001 | |
2fde4f94 | 1002 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
1003 | |
1004 | /* | |
2fde4f94 MR |
1005 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
1006 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
1007 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
1008 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 1009 | */ |
2fde4f94 | 1010 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 1011 | { |
2fde4f94 | 1012 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 1013 | |
e9d2b064 | 1014 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 1015 | |
2fde4f94 MR |
1016 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1017 | ||
1018 | list_add(&ctx->active_ctx_list, head); | |
1019 | } | |
1020 | ||
1021 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1022 | { | |
1023 | WARN_ON(!irqs_disabled()); | |
1024 | ||
1025 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1026 | ||
1027 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1028 | } |
9e35ad38 | 1029 | |
cdd6c482 | 1030 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1031 | { |
e5289d4a | 1032 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1033 | } |
1034 | ||
4af57ef2 YZ |
1035 | static void free_ctx(struct rcu_head *head) |
1036 | { | |
1037 | struct perf_event_context *ctx; | |
1038 | ||
1039 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1040 | kfree(ctx->task_ctx_data); | |
1041 | kfree(ctx); | |
1042 | } | |
1043 | ||
cdd6c482 | 1044 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1045 | { |
564c2b21 PM |
1046 | if (atomic_dec_and_test(&ctx->refcount)) { |
1047 | if (ctx->parent_ctx) | |
1048 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1049 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1050 | put_task_struct(ctx->task); |
4af57ef2 | 1051 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1052 | } |
a63eaf34 PM |
1053 | } |
1054 | ||
f63a8daa PZ |
1055 | /* |
1056 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1057 | * perf_pmu_migrate_context() we need some magic. | |
1058 | * | |
1059 | * Those places that change perf_event::ctx will hold both | |
1060 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1061 | * | |
8b10c5e2 PZ |
1062 | * Lock ordering is by mutex address. There are two other sites where |
1063 | * perf_event_context::mutex nests and those are: | |
1064 | * | |
1065 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1066 | * perf_event_exit_event() |
1067 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1068 | * |
1069 | * - perf_event_init_context() [ parent, 0 ] | |
1070 | * inherit_task_group() | |
1071 | * inherit_group() | |
1072 | * inherit_event() | |
1073 | * perf_event_alloc() | |
1074 | * perf_init_event() | |
1075 | * perf_try_init_event() [ child , 1 ] | |
1076 | * | |
1077 | * While it appears there is an obvious deadlock here -- the parent and child | |
1078 | * nesting levels are inverted between the two. This is in fact safe because | |
1079 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1080 | * spawning task cannot (yet) exit. | |
1081 | * | |
1082 | * But remember that that these are parent<->child context relations, and | |
1083 | * migration does not affect children, therefore these two orderings should not | |
1084 | * interact. | |
f63a8daa PZ |
1085 | * |
1086 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1087 | * because the sys_perf_event_open() case will install a new event and break | |
1088 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1089 | * concerned with cpuctx and that doesn't have children. | |
1090 | * | |
1091 | * The places that change perf_event::ctx will issue: | |
1092 | * | |
1093 | * perf_remove_from_context(); | |
1094 | * synchronize_rcu(); | |
1095 | * perf_install_in_context(); | |
1096 | * | |
1097 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1098 | * quiesce the event, after which we can install it in the new location. This | |
1099 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1100 | * while in transit. Therefore all such accessors should also acquire | |
1101 | * perf_event_context::mutex to serialize against this. | |
1102 | * | |
1103 | * However; because event->ctx can change while we're waiting to acquire | |
1104 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1105 | * function. | |
1106 | * | |
1107 | * Lock order: | |
1108 | * task_struct::perf_event_mutex | |
1109 | * perf_event_context::mutex | |
f63a8daa | 1110 | * perf_event::child_mutex; |
07c4a776 | 1111 | * perf_event_context::lock |
f63a8daa PZ |
1112 | * perf_event::mmap_mutex |
1113 | * mmap_sem | |
1114 | */ | |
a83fe28e PZ |
1115 | static struct perf_event_context * |
1116 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1117 | { |
1118 | struct perf_event_context *ctx; | |
1119 | ||
1120 | again: | |
1121 | rcu_read_lock(); | |
1122 | ctx = ACCESS_ONCE(event->ctx); | |
1123 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1124 | rcu_read_unlock(); | |
1125 | goto again; | |
1126 | } | |
1127 | rcu_read_unlock(); | |
1128 | ||
a83fe28e | 1129 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1130 | if (event->ctx != ctx) { |
1131 | mutex_unlock(&ctx->mutex); | |
1132 | put_ctx(ctx); | |
1133 | goto again; | |
1134 | } | |
1135 | ||
1136 | return ctx; | |
1137 | } | |
1138 | ||
a83fe28e PZ |
1139 | static inline struct perf_event_context * |
1140 | perf_event_ctx_lock(struct perf_event *event) | |
1141 | { | |
1142 | return perf_event_ctx_lock_nested(event, 0); | |
1143 | } | |
1144 | ||
f63a8daa PZ |
1145 | static void perf_event_ctx_unlock(struct perf_event *event, |
1146 | struct perf_event_context *ctx) | |
1147 | { | |
1148 | mutex_unlock(&ctx->mutex); | |
1149 | put_ctx(ctx); | |
1150 | } | |
1151 | ||
211de6eb PZ |
1152 | /* |
1153 | * This must be done under the ctx->lock, such as to serialize against | |
1154 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1155 | * calling scheduler related locks and ctx->lock nests inside those. | |
1156 | */ | |
1157 | static __must_check struct perf_event_context * | |
1158 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1159 | { |
211de6eb PZ |
1160 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1161 | ||
1162 | lockdep_assert_held(&ctx->lock); | |
1163 | ||
1164 | if (parent_ctx) | |
71a851b4 | 1165 | ctx->parent_ctx = NULL; |
5a3126d4 | 1166 | ctx->generation++; |
211de6eb PZ |
1167 | |
1168 | return parent_ctx; | |
71a851b4 PZ |
1169 | } |
1170 | ||
6844c09d ACM |
1171 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1172 | { | |
1173 | /* | |
1174 | * only top level events have the pid namespace they were created in | |
1175 | */ | |
1176 | if (event->parent) | |
1177 | event = event->parent; | |
1178 | ||
1179 | return task_tgid_nr_ns(p, event->ns); | |
1180 | } | |
1181 | ||
1182 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1183 | { | |
1184 | /* | |
1185 | * only top level events have the pid namespace they were created in | |
1186 | */ | |
1187 | if (event->parent) | |
1188 | event = event->parent; | |
1189 | ||
1190 | return task_pid_nr_ns(p, event->ns); | |
1191 | } | |
1192 | ||
7f453c24 | 1193 | /* |
cdd6c482 | 1194 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1195 | * to userspace. |
1196 | */ | |
cdd6c482 | 1197 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1198 | { |
cdd6c482 | 1199 | u64 id = event->id; |
7f453c24 | 1200 | |
cdd6c482 IM |
1201 | if (event->parent) |
1202 | id = event->parent->id; | |
7f453c24 PZ |
1203 | |
1204 | return id; | |
1205 | } | |
1206 | ||
25346b93 | 1207 | /* |
cdd6c482 | 1208 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1209 | * |
25346b93 PM |
1210 | * This has to cope with with the fact that until it is locked, |
1211 | * the context could get moved to another task. | |
1212 | */ | |
cdd6c482 | 1213 | static struct perf_event_context * |
8dc85d54 | 1214 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1215 | { |
cdd6c482 | 1216 | struct perf_event_context *ctx; |
25346b93 | 1217 | |
9ed6060d | 1218 | retry: |
058ebd0e PZ |
1219 | /* |
1220 | * One of the few rules of preemptible RCU is that one cannot do | |
1221 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1222 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1223 | * rcu_read_unlock_special(). |
1224 | * | |
1225 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1226 | * side critical section has interrupts disabled. |
058ebd0e | 1227 | */ |
2fd59077 | 1228 | local_irq_save(*flags); |
058ebd0e | 1229 | rcu_read_lock(); |
8dc85d54 | 1230 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1231 | if (ctx) { |
1232 | /* | |
1233 | * If this context is a clone of another, it might | |
1234 | * get swapped for another underneath us by | |
cdd6c482 | 1235 | * perf_event_task_sched_out, though the |
25346b93 PM |
1236 | * rcu_read_lock() protects us from any context |
1237 | * getting freed. Lock the context and check if it | |
1238 | * got swapped before we could get the lock, and retry | |
1239 | * if so. If we locked the right context, then it | |
1240 | * can't get swapped on us any more. | |
1241 | */ | |
2fd59077 | 1242 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1243 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1244 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1245 | rcu_read_unlock(); |
2fd59077 | 1246 | local_irq_restore(*flags); |
25346b93 PM |
1247 | goto retry; |
1248 | } | |
b49a9e7e | 1249 | |
63b6da39 PZ |
1250 | if (ctx->task == TASK_TOMBSTONE || |
1251 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1252 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1253 | ctx = NULL; |
828b6f0e PZ |
1254 | } else { |
1255 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1256 | } |
25346b93 PM |
1257 | } |
1258 | rcu_read_unlock(); | |
2fd59077 PM |
1259 | if (!ctx) |
1260 | local_irq_restore(*flags); | |
25346b93 PM |
1261 | return ctx; |
1262 | } | |
1263 | ||
1264 | /* | |
1265 | * Get the context for a task and increment its pin_count so it | |
1266 | * can't get swapped to another task. This also increments its | |
1267 | * reference count so that the context can't get freed. | |
1268 | */ | |
8dc85d54 PZ |
1269 | static struct perf_event_context * |
1270 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1271 | { |
cdd6c482 | 1272 | struct perf_event_context *ctx; |
25346b93 PM |
1273 | unsigned long flags; |
1274 | ||
8dc85d54 | 1275 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1276 | if (ctx) { |
1277 | ++ctx->pin_count; | |
e625cce1 | 1278 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1279 | } |
1280 | return ctx; | |
1281 | } | |
1282 | ||
cdd6c482 | 1283 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1284 | { |
1285 | unsigned long flags; | |
1286 | ||
e625cce1 | 1287 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1288 | --ctx->pin_count; |
e625cce1 | 1289 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1290 | } |
1291 | ||
f67218c3 PZ |
1292 | /* |
1293 | * Update the record of the current time in a context. | |
1294 | */ | |
1295 | static void update_context_time(struct perf_event_context *ctx) | |
1296 | { | |
1297 | u64 now = perf_clock(); | |
1298 | ||
1299 | ctx->time += now - ctx->timestamp; | |
1300 | ctx->timestamp = now; | |
1301 | } | |
1302 | ||
4158755d SE |
1303 | static u64 perf_event_time(struct perf_event *event) |
1304 | { | |
1305 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1306 | |
1307 | if (is_cgroup_event(event)) | |
1308 | return perf_cgroup_event_time(event); | |
1309 | ||
4158755d SE |
1310 | return ctx ? ctx->time : 0; |
1311 | } | |
1312 | ||
f67218c3 PZ |
1313 | /* |
1314 | * Update the total_time_enabled and total_time_running fields for a event. | |
1315 | */ | |
1316 | static void update_event_times(struct perf_event *event) | |
1317 | { | |
1318 | struct perf_event_context *ctx = event->ctx; | |
1319 | u64 run_end; | |
1320 | ||
3cbaa590 PZ |
1321 | lockdep_assert_held(&ctx->lock); |
1322 | ||
f67218c3 PZ |
1323 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
1324 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1325 | return; | |
3cbaa590 | 1326 | |
e5d1367f SE |
1327 | /* |
1328 | * in cgroup mode, time_enabled represents | |
1329 | * the time the event was enabled AND active | |
1330 | * tasks were in the monitored cgroup. This is | |
1331 | * independent of the activity of the context as | |
1332 | * there may be a mix of cgroup and non-cgroup events. | |
1333 | * | |
1334 | * That is why we treat cgroup events differently | |
1335 | * here. | |
1336 | */ | |
1337 | if (is_cgroup_event(event)) | |
46cd6a7f | 1338 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1339 | else if (ctx->is_active) |
1340 | run_end = ctx->time; | |
acd1d7c1 PZ |
1341 | else |
1342 | run_end = event->tstamp_stopped; | |
1343 | ||
1344 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1345 | |
1346 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1347 | run_end = event->tstamp_stopped; | |
1348 | else | |
4158755d | 1349 | run_end = perf_event_time(event); |
f67218c3 PZ |
1350 | |
1351 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1352 | |
f67218c3 PZ |
1353 | } |
1354 | ||
96c21a46 PZ |
1355 | /* |
1356 | * Update total_time_enabled and total_time_running for all events in a group. | |
1357 | */ | |
1358 | static void update_group_times(struct perf_event *leader) | |
1359 | { | |
1360 | struct perf_event *event; | |
1361 | ||
1362 | update_event_times(leader); | |
1363 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1364 | update_event_times(event); | |
1365 | } | |
1366 | ||
889ff015 FW |
1367 | static struct list_head * |
1368 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1369 | { | |
1370 | if (event->attr.pinned) | |
1371 | return &ctx->pinned_groups; | |
1372 | else | |
1373 | return &ctx->flexible_groups; | |
1374 | } | |
1375 | ||
fccc714b | 1376 | /* |
cdd6c482 | 1377 | * Add a event from the lists for its context. |
fccc714b PZ |
1378 | * Must be called with ctx->mutex and ctx->lock held. |
1379 | */ | |
04289bb9 | 1380 | static void |
cdd6c482 | 1381 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1382 | { |
c994d613 PZ |
1383 | lockdep_assert_held(&ctx->lock); |
1384 | ||
8a49542c PZ |
1385 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1386 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1387 | |
1388 | /* | |
8a49542c PZ |
1389 | * If we're a stand alone event or group leader, we go to the context |
1390 | * list, group events are kept attached to the group so that | |
1391 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1392 | */ |
8a49542c | 1393 | if (event->group_leader == event) { |
889ff015 FW |
1394 | struct list_head *list; |
1395 | ||
d6f962b5 FW |
1396 | if (is_software_event(event)) |
1397 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1398 | ||
889ff015 FW |
1399 | list = ctx_group_list(event, ctx); |
1400 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1401 | } |
592903cd | 1402 | |
08309379 | 1403 | if (is_cgroup_event(event)) |
e5d1367f | 1404 | ctx->nr_cgroups++; |
e5d1367f | 1405 | |
cdd6c482 IM |
1406 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1407 | ctx->nr_events++; | |
1408 | if (event->attr.inherit_stat) | |
bfbd3381 | 1409 | ctx->nr_stat++; |
5a3126d4 PZ |
1410 | |
1411 | ctx->generation++; | |
04289bb9 IM |
1412 | } |
1413 | ||
0231bb53 JO |
1414 | /* |
1415 | * Initialize event state based on the perf_event_attr::disabled. | |
1416 | */ | |
1417 | static inline void perf_event__state_init(struct perf_event *event) | |
1418 | { | |
1419 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1420 | PERF_EVENT_STATE_INACTIVE; | |
1421 | } | |
1422 | ||
a723968c | 1423 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1424 | { |
1425 | int entry = sizeof(u64); /* value */ | |
1426 | int size = 0; | |
1427 | int nr = 1; | |
1428 | ||
1429 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1430 | size += sizeof(u64); | |
1431 | ||
1432 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1433 | size += sizeof(u64); | |
1434 | ||
1435 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1436 | entry += sizeof(u64); | |
1437 | ||
1438 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1439 | nr += nr_siblings; |
c320c7b7 ACM |
1440 | size += sizeof(u64); |
1441 | } | |
1442 | ||
1443 | size += entry * nr; | |
1444 | event->read_size = size; | |
1445 | } | |
1446 | ||
a723968c | 1447 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1448 | { |
1449 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1450 | u16 size = 0; |
1451 | ||
c320c7b7 ACM |
1452 | if (sample_type & PERF_SAMPLE_IP) |
1453 | size += sizeof(data->ip); | |
1454 | ||
6844c09d ACM |
1455 | if (sample_type & PERF_SAMPLE_ADDR) |
1456 | size += sizeof(data->addr); | |
1457 | ||
1458 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1459 | size += sizeof(data->period); | |
1460 | ||
c3feedf2 AK |
1461 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1462 | size += sizeof(data->weight); | |
1463 | ||
6844c09d ACM |
1464 | if (sample_type & PERF_SAMPLE_READ) |
1465 | size += event->read_size; | |
1466 | ||
d6be9ad6 SE |
1467 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1468 | size += sizeof(data->data_src.val); | |
1469 | ||
fdfbbd07 AK |
1470 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1471 | size += sizeof(data->txn); | |
1472 | ||
6844c09d ACM |
1473 | event->header_size = size; |
1474 | } | |
1475 | ||
a723968c PZ |
1476 | /* |
1477 | * Called at perf_event creation and when events are attached/detached from a | |
1478 | * group. | |
1479 | */ | |
1480 | static void perf_event__header_size(struct perf_event *event) | |
1481 | { | |
1482 | __perf_event_read_size(event, | |
1483 | event->group_leader->nr_siblings); | |
1484 | __perf_event_header_size(event, event->attr.sample_type); | |
1485 | } | |
1486 | ||
6844c09d ACM |
1487 | static void perf_event__id_header_size(struct perf_event *event) |
1488 | { | |
1489 | struct perf_sample_data *data; | |
1490 | u64 sample_type = event->attr.sample_type; | |
1491 | u16 size = 0; | |
1492 | ||
c320c7b7 ACM |
1493 | if (sample_type & PERF_SAMPLE_TID) |
1494 | size += sizeof(data->tid_entry); | |
1495 | ||
1496 | if (sample_type & PERF_SAMPLE_TIME) | |
1497 | size += sizeof(data->time); | |
1498 | ||
ff3d527c AH |
1499 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1500 | size += sizeof(data->id); | |
1501 | ||
c320c7b7 ACM |
1502 | if (sample_type & PERF_SAMPLE_ID) |
1503 | size += sizeof(data->id); | |
1504 | ||
1505 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1506 | size += sizeof(data->stream_id); | |
1507 | ||
1508 | if (sample_type & PERF_SAMPLE_CPU) | |
1509 | size += sizeof(data->cpu_entry); | |
1510 | ||
6844c09d | 1511 | event->id_header_size = size; |
c320c7b7 ACM |
1512 | } |
1513 | ||
a723968c PZ |
1514 | static bool perf_event_validate_size(struct perf_event *event) |
1515 | { | |
1516 | /* | |
1517 | * The values computed here will be over-written when we actually | |
1518 | * attach the event. | |
1519 | */ | |
1520 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1521 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1522 | perf_event__id_header_size(event); | |
1523 | ||
1524 | /* | |
1525 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1526 | * Conservative limit to allow for callchains and other variable fields. | |
1527 | */ | |
1528 | if (event->read_size + event->header_size + | |
1529 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1530 | return false; | |
1531 | ||
1532 | return true; | |
1533 | } | |
1534 | ||
8a49542c PZ |
1535 | static void perf_group_attach(struct perf_event *event) |
1536 | { | |
c320c7b7 | 1537 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1538 | |
74c3337c PZ |
1539 | /* |
1540 | * We can have double attach due to group movement in perf_event_open. | |
1541 | */ | |
1542 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1543 | return; | |
1544 | ||
8a49542c PZ |
1545 | event->attach_state |= PERF_ATTACH_GROUP; |
1546 | ||
1547 | if (group_leader == event) | |
1548 | return; | |
1549 | ||
652884fe PZ |
1550 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1551 | ||
8a49542c PZ |
1552 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1553 | !is_software_event(event)) | |
1554 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1555 | ||
1556 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1557 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1558 | |
1559 | perf_event__header_size(group_leader); | |
1560 | ||
1561 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1562 | perf_event__header_size(pos); | |
8a49542c PZ |
1563 | } |
1564 | ||
a63eaf34 | 1565 | /* |
cdd6c482 | 1566 | * Remove a event from the lists for its context. |
fccc714b | 1567 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1568 | */ |
04289bb9 | 1569 | static void |
cdd6c482 | 1570 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1571 | { |
68cacd29 | 1572 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1573 | |
1574 | WARN_ON_ONCE(event->ctx != ctx); | |
1575 | lockdep_assert_held(&ctx->lock); | |
1576 | ||
8a49542c PZ |
1577 | /* |
1578 | * We can have double detach due to exit/hot-unplug + close. | |
1579 | */ | |
1580 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1581 | return; |
8a49542c PZ |
1582 | |
1583 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1584 | ||
68cacd29 | 1585 | if (is_cgroup_event(event)) { |
e5d1367f | 1586 | ctx->nr_cgroups--; |
70a01657 PZ |
1587 | /* |
1588 | * Because cgroup events are always per-cpu events, this will | |
1589 | * always be called from the right CPU. | |
1590 | */ | |
68cacd29 SE |
1591 | cpuctx = __get_cpu_context(ctx); |
1592 | /* | |
70a01657 PZ |
1593 | * If there are no more cgroup events then clear cgrp to avoid |
1594 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1595 | */ |
1596 | if (!ctx->nr_cgroups) | |
1597 | cpuctx->cgrp = NULL; | |
1598 | } | |
e5d1367f | 1599 | |
cdd6c482 IM |
1600 | ctx->nr_events--; |
1601 | if (event->attr.inherit_stat) | |
bfbd3381 | 1602 | ctx->nr_stat--; |
8bc20959 | 1603 | |
cdd6c482 | 1604 | list_del_rcu(&event->event_entry); |
04289bb9 | 1605 | |
8a49542c PZ |
1606 | if (event->group_leader == event) |
1607 | list_del_init(&event->group_entry); | |
5c148194 | 1608 | |
96c21a46 | 1609 | update_group_times(event); |
b2e74a26 SE |
1610 | |
1611 | /* | |
1612 | * If event was in error state, then keep it | |
1613 | * that way, otherwise bogus counts will be | |
1614 | * returned on read(). The only way to get out | |
1615 | * of error state is by explicit re-enabling | |
1616 | * of the event | |
1617 | */ | |
1618 | if (event->state > PERF_EVENT_STATE_OFF) | |
1619 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1620 | |
1621 | ctx->generation++; | |
050735b0 PZ |
1622 | } |
1623 | ||
8a49542c | 1624 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1625 | { |
1626 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1627 | struct list_head *list = NULL; |
1628 | ||
1629 | /* | |
1630 | * We can have double detach due to exit/hot-unplug + close. | |
1631 | */ | |
1632 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1633 | return; | |
1634 | ||
1635 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1636 | ||
1637 | /* | |
1638 | * If this is a sibling, remove it from its group. | |
1639 | */ | |
1640 | if (event->group_leader != event) { | |
1641 | list_del_init(&event->group_entry); | |
1642 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1643 | goto out; |
8a49542c PZ |
1644 | } |
1645 | ||
1646 | if (!list_empty(&event->group_entry)) | |
1647 | list = &event->group_entry; | |
2e2af50b | 1648 | |
04289bb9 | 1649 | /* |
cdd6c482 IM |
1650 | * If this was a group event with sibling events then |
1651 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1652 | * to whatever list we are on. |
04289bb9 | 1653 | */ |
cdd6c482 | 1654 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1655 | if (list) |
1656 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1657 | sibling->group_leader = sibling; |
d6f962b5 FW |
1658 | |
1659 | /* Inherit group flags from the previous leader */ | |
1660 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1661 | |
1662 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1663 | } |
c320c7b7 ACM |
1664 | |
1665 | out: | |
1666 | perf_event__header_size(event->group_leader); | |
1667 | ||
1668 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1669 | perf_event__header_size(tmp); | |
04289bb9 IM |
1670 | } |
1671 | ||
fadfe7be JO |
1672 | static bool is_orphaned_event(struct perf_event *event) |
1673 | { | |
a69b0ca4 | 1674 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1675 | } |
1676 | ||
66eb579e MR |
1677 | static inline int pmu_filter_match(struct perf_event *event) |
1678 | { | |
1679 | struct pmu *pmu = event->pmu; | |
1680 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1681 | } | |
1682 | ||
fa66f07a SE |
1683 | static inline int |
1684 | event_filter_match(struct perf_event *event) | |
1685 | { | |
e5d1367f | 1686 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1687 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1688 | } |
1689 | ||
9ffcfa6f SE |
1690 | static void |
1691 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1692 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1693 | struct perf_event_context *ctx) |
3b6f9e5c | 1694 | { |
4158755d | 1695 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1696 | u64 delta; |
652884fe PZ |
1697 | |
1698 | WARN_ON_ONCE(event->ctx != ctx); | |
1699 | lockdep_assert_held(&ctx->lock); | |
1700 | ||
fa66f07a SE |
1701 | /* |
1702 | * An event which could not be activated because of | |
1703 | * filter mismatch still needs to have its timings | |
1704 | * maintained, otherwise bogus information is return | |
1705 | * via read() for time_enabled, time_running: | |
1706 | */ | |
1707 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1708 | && !event_filter_match(event)) { | |
e5d1367f | 1709 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1710 | event->tstamp_running += delta; |
4158755d | 1711 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1712 | } |
1713 | ||
cdd6c482 | 1714 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1715 | return; |
3b6f9e5c | 1716 | |
44377277 AS |
1717 | perf_pmu_disable(event->pmu); |
1718 | ||
28a967c3 PZ |
1719 | event->tstamp_stopped = tstamp; |
1720 | event->pmu->del(event, 0); | |
1721 | event->oncpu = -1; | |
cdd6c482 IM |
1722 | event->state = PERF_EVENT_STATE_INACTIVE; |
1723 | if (event->pending_disable) { | |
1724 | event->pending_disable = 0; | |
1725 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1726 | } |
3b6f9e5c | 1727 | |
cdd6c482 | 1728 | if (!is_software_event(event)) |
3b6f9e5c | 1729 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1730 | if (!--ctx->nr_active) |
1731 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1732 | if (event->attr.freq && event->attr.sample_freq) |
1733 | ctx->nr_freq--; | |
cdd6c482 | 1734 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1735 | cpuctx->exclusive = 0; |
44377277 AS |
1736 | |
1737 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1738 | } |
1739 | ||
d859e29f | 1740 | static void |
cdd6c482 | 1741 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1742 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1743 | struct perf_event_context *ctx) |
d859e29f | 1744 | { |
cdd6c482 | 1745 | struct perf_event *event; |
fa66f07a | 1746 | int state = group_event->state; |
d859e29f | 1747 | |
cdd6c482 | 1748 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1749 | |
1750 | /* | |
1751 | * Schedule out siblings (if any): | |
1752 | */ | |
cdd6c482 IM |
1753 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1754 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1755 | |
fa66f07a | 1756 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1757 | cpuctx->exclusive = 0; |
1758 | } | |
1759 | ||
45a0e07a | 1760 | #define DETACH_GROUP 0x01UL |
0017960f | 1761 | |
0793a61d | 1762 | /* |
cdd6c482 | 1763 | * Cross CPU call to remove a performance event |
0793a61d | 1764 | * |
cdd6c482 | 1765 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1766 | * remove it from the context list. |
1767 | */ | |
fae3fde6 PZ |
1768 | static void |
1769 | __perf_remove_from_context(struct perf_event *event, | |
1770 | struct perf_cpu_context *cpuctx, | |
1771 | struct perf_event_context *ctx, | |
1772 | void *info) | |
0793a61d | 1773 | { |
45a0e07a | 1774 | unsigned long flags = (unsigned long)info; |
0793a61d | 1775 | |
cdd6c482 | 1776 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1777 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1778 | perf_group_detach(event); |
cdd6c482 | 1779 | list_del_event(event, ctx); |
39a43640 PZ |
1780 | |
1781 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1782 | ctx->is_active = 0; |
39a43640 PZ |
1783 | if (ctx->task) { |
1784 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1785 | cpuctx->task_ctx = NULL; | |
1786 | } | |
64ce3126 | 1787 | } |
0793a61d TG |
1788 | } |
1789 | ||
0793a61d | 1790 | /* |
cdd6c482 | 1791 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1792 | * |
cdd6c482 IM |
1793 | * If event->ctx is a cloned context, callers must make sure that |
1794 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1795 | * remains valid. This is OK when called from perf_release since |
1796 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1797 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1798 | * context has been detached from its task. |
0793a61d | 1799 | */ |
45a0e07a | 1800 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1801 | { |
fae3fde6 | 1802 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1803 | |
45a0e07a | 1804 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1805 | } |
1806 | ||
d859e29f | 1807 | /* |
cdd6c482 | 1808 | * Cross CPU call to disable a performance event |
d859e29f | 1809 | */ |
fae3fde6 PZ |
1810 | static void __perf_event_disable(struct perf_event *event, |
1811 | struct perf_cpu_context *cpuctx, | |
1812 | struct perf_event_context *ctx, | |
1813 | void *info) | |
7b648018 | 1814 | { |
fae3fde6 PZ |
1815 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1816 | return; | |
7b648018 | 1817 | |
fae3fde6 PZ |
1818 | update_context_time(ctx); |
1819 | update_cgrp_time_from_event(event); | |
1820 | update_group_times(event); | |
1821 | if (event == event->group_leader) | |
1822 | group_sched_out(event, cpuctx, ctx); | |
1823 | else | |
1824 | event_sched_out(event, cpuctx, ctx); | |
1825 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1826 | } |
1827 | ||
d859e29f | 1828 | /* |
cdd6c482 | 1829 | * Disable a event. |
c93f7669 | 1830 | * |
cdd6c482 IM |
1831 | * If event->ctx is a cloned context, callers must make sure that |
1832 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1833 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1834 | * perf_event_for_each_child or perf_event_for_each because they |
1835 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1836 | * goes to exit will block in perf_event_exit_event(). |
1837 | * | |
cdd6c482 | 1838 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1839 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1840 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1841 | */ |
f63a8daa | 1842 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1843 | { |
cdd6c482 | 1844 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1845 | |
e625cce1 | 1846 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1847 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1848 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1849 | return; |
53cfbf59 | 1850 | } |
e625cce1 | 1851 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1852 | |
fae3fde6 PZ |
1853 | event_function_call(event, __perf_event_disable, NULL); |
1854 | } | |
1855 | ||
1856 | void perf_event_disable_local(struct perf_event *event) | |
1857 | { | |
1858 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1859 | } |
f63a8daa PZ |
1860 | |
1861 | /* | |
1862 | * Strictly speaking kernel users cannot create groups and therefore this | |
1863 | * interface does not need the perf_event_ctx_lock() magic. | |
1864 | */ | |
1865 | void perf_event_disable(struct perf_event *event) | |
1866 | { | |
1867 | struct perf_event_context *ctx; | |
1868 | ||
1869 | ctx = perf_event_ctx_lock(event); | |
1870 | _perf_event_disable(event); | |
1871 | perf_event_ctx_unlock(event, ctx); | |
1872 | } | |
dcfce4a0 | 1873 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1874 | |
e5d1367f SE |
1875 | static void perf_set_shadow_time(struct perf_event *event, |
1876 | struct perf_event_context *ctx, | |
1877 | u64 tstamp) | |
1878 | { | |
1879 | /* | |
1880 | * use the correct time source for the time snapshot | |
1881 | * | |
1882 | * We could get by without this by leveraging the | |
1883 | * fact that to get to this function, the caller | |
1884 | * has most likely already called update_context_time() | |
1885 | * and update_cgrp_time_xx() and thus both timestamp | |
1886 | * are identical (or very close). Given that tstamp is, | |
1887 | * already adjusted for cgroup, we could say that: | |
1888 | * tstamp - ctx->timestamp | |
1889 | * is equivalent to | |
1890 | * tstamp - cgrp->timestamp. | |
1891 | * | |
1892 | * Then, in perf_output_read(), the calculation would | |
1893 | * work with no changes because: | |
1894 | * - event is guaranteed scheduled in | |
1895 | * - no scheduled out in between | |
1896 | * - thus the timestamp would be the same | |
1897 | * | |
1898 | * But this is a bit hairy. | |
1899 | * | |
1900 | * So instead, we have an explicit cgroup call to remain | |
1901 | * within the time time source all along. We believe it | |
1902 | * is cleaner and simpler to understand. | |
1903 | */ | |
1904 | if (is_cgroup_event(event)) | |
1905 | perf_cgroup_set_shadow_time(event, tstamp); | |
1906 | else | |
1907 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1908 | } | |
1909 | ||
4fe757dd PZ |
1910 | #define MAX_INTERRUPTS (~0ULL) |
1911 | ||
1912 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1913 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1914 | |
235c7fc7 | 1915 | static int |
9ffcfa6f | 1916 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1917 | struct perf_cpu_context *cpuctx, |
6e37738a | 1918 | struct perf_event_context *ctx) |
235c7fc7 | 1919 | { |
4158755d | 1920 | u64 tstamp = perf_event_time(event); |
44377277 | 1921 | int ret = 0; |
4158755d | 1922 | |
63342411 PZ |
1923 | lockdep_assert_held(&ctx->lock); |
1924 | ||
cdd6c482 | 1925 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1926 | return 0; |
1927 | ||
95ff4ca2 AS |
1928 | WRITE_ONCE(event->oncpu, smp_processor_id()); |
1929 | /* | |
1930 | * Order event::oncpu write to happen before the ACTIVE state | |
1931 | * is visible. | |
1932 | */ | |
1933 | smp_wmb(); | |
1934 | WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE); | |
4fe757dd PZ |
1935 | |
1936 | /* | |
1937 | * Unthrottle events, since we scheduled we might have missed several | |
1938 | * ticks already, also for a heavily scheduling task there is little | |
1939 | * guarantee it'll get a tick in a timely manner. | |
1940 | */ | |
1941 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1942 | perf_log_throttle(event, 1); | |
1943 | event->hw.interrupts = 0; | |
1944 | } | |
1945 | ||
235c7fc7 IM |
1946 | /* |
1947 | * The new state must be visible before we turn it on in the hardware: | |
1948 | */ | |
1949 | smp_wmb(); | |
1950 | ||
44377277 AS |
1951 | perf_pmu_disable(event->pmu); |
1952 | ||
72f669c0 SL |
1953 | perf_set_shadow_time(event, ctx, tstamp); |
1954 | ||
ec0d7729 AS |
1955 | perf_log_itrace_start(event); |
1956 | ||
a4eaf7f1 | 1957 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1958 | event->state = PERF_EVENT_STATE_INACTIVE; |
1959 | event->oncpu = -1; | |
44377277 AS |
1960 | ret = -EAGAIN; |
1961 | goto out; | |
235c7fc7 IM |
1962 | } |
1963 | ||
00a2916f PZ |
1964 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1965 | ||
cdd6c482 | 1966 | if (!is_software_event(event)) |
3b6f9e5c | 1967 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1968 | if (!ctx->nr_active++) |
1969 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1970 | if (event->attr.freq && event->attr.sample_freq) |
1971 | ctx->nr_freq++; | |
235c7fc7 | 1972 | |
cdd6c482 | 1973 | if (event->attr.exclusive) |
3b6f9e5c PM |
1974 | cpuctx->exclusive = 1; |
1975 | ||
44377277 AS |
1976 | out: |
1977 | perf_pmu_enable(event->pmu); | |
1978 | ||
1979 | return ret; | |
235c7fc7 IM |
1980 | } |
1981 | ||
6751b71e | 1982 | static int |
cdd6c482 | 1983 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1984 | struct perf_cpu_context *cpuctx, |
6e37738a | 1985 | struct perf_event_context *ctx) |
6751b71e | 1986 | { |
6bde9b6c | 1987 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1988 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1989 | u64 now = ctx->time; |
1990 | bool simulate = false; | |
6751b71e | 1991 | |
cdd6c482 | 1992 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1993 | return 0; |
1994 | ||
fbbe0701 | 1995 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1996 | |
9ffcfa6f | 1997 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1998 | pmu->cancel_txn(pmu); |
272325c4 | 1999 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 2000 | return -EAGAIN; |
90151c35 | 2001 | } |
6751b71e PM |
2002 | |
2003 | /* | |
2004 | * Schedule in siblings as one group (if any): | |
2005 | */ | |
cdd6c482 | 2006 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 2007 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 2008 | partial_group = event; |
6751b71e PM |
2009 | goto group_error; |
2010 | } | |
2011 | } | |
2012 | ||
9ffcfa6f | 2013 | if (!pmu->commit_txn(pmu)) |
6e85158c | 2014 | return 0; |
9ffcfa6f | 2015 | |
6751b71e PM |
2016 | group_error: |
2017 | /* | |
2018 | * Groups can be scheduled in as one unit only, so undo any | |
2019 | * partial group before returning: | |
d7842da4 SE |
2020 | * The events up to the failed event are scheduled out normally, |
2021 | * tstamp_stopped will be updated. | |
2022 | * | |
2023 | * The failed events and the remaining siblings need to have | |
2024 | * their timings updated as if they had gone thru event_sched_in() | |
2025 | * and event_sched_out(). This is required to get consistent timings | |
2026 | * across the group. This also takes care of the case where the group | |
2027 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2028 | * the time the event was actually stopped, such that time delta | |
2029 | * calculation in update_event_times() is correct. | |
6751b71e | 2030 | */ |
cdd6c482 IM |
2031 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2032 | if (event == partial_group) | |
d7842da4 SE |
2033 | simulate = true; |
2034 | ||
2035 | if (simulate) { | |
2036 | event->tstamp_running += now - event->tstamp_stopped; | |
2037 | event->tstamp_stopped = now; | |
2038 | } else { | |
2039 | event_sched_out(event, cpuctx, ctx); | |
2040 | } | |
6751b71e | 2041 | } |
9ffcfa6f | 2042 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2043 | |
ad5133b7 | 2044 | pmu->cancel_txn(pmu); |
90151c35 | 2045 | |
272325c4 | 2046 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2047 | |
6751b71e PM |
2048 | return -EAGAIN; |
2049 | } | |
2050 | ||
3b6f9e5c | 2051 | /* |
cdd6c482 | 2052 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2053 | */ |
cdd6c482 | 2054 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2055 | struct perf_cpu_context *cpuctx, |
2056 | int can_add_hw) | |
2057 | { | |
2058 | /* | |
cdd6c482 | 2059 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2060 | */ |
d6f962b5 | 2061 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2062 | return 1; |
2063 | /* | |
2064 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2065 | * events can go on. |
3b6f9e5c PM |
2066 | */ |
2067 | if (cpuctx->exclusive) | |
2068 | return 0; | |
2069 | /* | |
2070 | * If this group is exclusive and there are already | |
cdd6c482 | 2071 | * events on the CPU, it can't go on. |
3b6f9e5c | 2072 | */ |
cdd6c482 | 2073 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2074 | return 0; |
2075 | /* | |
2076 | * Otherwise, try to add it if all previous groups were able | |
2077 | * to go on. | |
2078 | */ | |
2079 | return can_add_hw; | |
2080 | } | |
2081 | ||
cdd6c482 IM |
2082 | static void add_event_to_ctx(struct perf_event *event, |
2083 | struct perf_event_context *ctx) | |
53cfbf59 | 2084 | { |
4158755d SE |
2085 | u64 tstamp = perf_event_time(event); |
2086 | ||
cdd6c482 | 2087 | list_add_event(event, ctx); |
8a49542c | 2088 | perf_group_attach(event); |
4158755d SE |
2089 | event->tstamp_enabled = tstamp; |
2090 | event->tstamp_running = tstamp; | |
2091 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2092 | } |
2093 | ||
bd2afa49 PZ |
2094 | static void ctx_sched_out(struct perf_event_context *ctx, |
2095 | struct perf_cpu_context *cpuctx, | |
2096 | enum event_type_t event_type); | |
2c29ef0f PZ |
2097 | static void |
2098 | ctx_sched_in(struct perf_event_context *ctx, | |
2099 | struct perf_cpu_context *cpuctx, | |
2100 | enum event_type_t event_type, | |
2101 | struct task_struct *task); | |
fe4b04fa | 2102 | |
bd2afa49 PZ |
2103 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2104 | struct perf_event_context *ctx) | |
2105 | { | |
2106 | if (!cpuctx->task_ctx) | |
2107 | return; | |
2108 | ||
2109 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2110 | return; | |
2111 | ||
2112 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); | |
2113 | } | |
2114 | ||
dce5855b PZ |
2115 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2116 | struct perf_event_context *ctx, | |
2117 | struct task_struct *task) | |
2118 | { | |
2119 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2120 | if (ctx) | |
2121 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2122 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2123 | if (ctx) | |
2124 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2125 | } | |
2126 | ||
3e349507 PZ |
2127 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2128 | struct perf_event_context *task_ctx) | |
0017960f | 2129 | { |
3e349507 PZ |
2130 | perf_pmu_disable(cpuctx->ctx.pmu); |
2131 | if (task_ctx) | |
2132 | task_ctx_sched_out(cpuctx, task_ctx); | |
2133 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2134 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2135 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2136 | } |
2137 | ||
0793a61d | 2138 | /* |
cdd6c482 | 2139 | * Cross CPU call to install and enable a performance event |
682076ae | 2140 | * |
a096309b PZ |
2141 | * Very similar to remote_function() + event_function() but cannot assume that |
2142 | * things like ctx->is_active and cpuctx->task_ctx are set. | |
0793a61d | 2143 | */ |
fe4b04fa | 2144 | static int __perf_install_in_context(void *info) |
0793a61d | 2145 | { |
a096309b PZ |
2146 | struct perf_event *event = info; |
2147 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2148 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2149 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
a096309b PZ |
2150 | bool activate = true; |
2151 | int ret = 0; | |
0793a61d | 2152 | |
63b6da39 | 2153 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2154 | if (ctx->task) { |
b58f6b0d PZ |
2155 | raw_spin_lock(&ctx->lock); |
2156 | task_ctx = ctx; | |
a096309b PZ |
2157 | |
2158 | /* If we're on the wrong CPU, try again */ | |
2159 | if (task_cpu(ctx->task) != smp_processor_id()) { | |
2160 | ret = -ESRCH; | |
63b6da39 | 2161 | goto unlock; |
a096309b | 2162 | } |
b58f6b0d | 2163 | |
39a43640 | 2164 | /* |
a096309b PZ |
2165 | * If we're on the right CPU, see if the task we target is |
2166 | * current, if not we don't have to activate the ctx, a future | |
2167 | * context switch will do that for us. | |
39a43640 | 2168 | */ |
a096309b PZ |
2169 | if (ctx->task != current) |
2170 | activate = false; | |
2171 | else | |
2172 | WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx); | |
2173 | ||
63b6da39 PZ |
2174 | } else if (task_ctx) { |
2175 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2176 | } |
b58f6b0d | 2177 | |
a096309b PZ |
2178 | if (activate) { |
2179 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2180 | add_event_to_ctx(event, ctx); | |
2181 | ctx_resched(cpuctx, task_ctx); | |
2182 | } else { | |
2183 | add_event_to_ctx(event, ctx); | |
2184 | } | |
2185 | ||
63b6da39 | 2186 | unlock: |
2c29ef0f | 2187 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa | 2188 | |
a096309b | 2189 | return ret; |
0793a61d TG |
2190 | } |
2191 | ||
2192 | /* | |
a096309b PZ |
2193 | * Attach a performance event to a context. |
2194 | * | |
2195 | * Very similar to event_function_call, see comment there. | |
0793a61d TG |
2196 | */ |
2197 | static void | |
cdd6c482 IM |
2198 | perf_install_in_context(struct perf_event_context *ctx, |
2199 | struct perf_event *event, | |
0793a61d TG |
2200 | int cpu) |
2201 | { | |
a096309b | 2202 | struct task_struct *task = READ_ONCE(ctx->task); |
39a43640 | 2203 | |
fe4b04fa PZ |
2204 | lockdep_assert_held(&ctx->mutex); |
2205 | ||
c3f00c70 | 2206 | event->ctx = ctx; |
0cda4c02 YZ |
2207 | if (event->cpu != -1) |
2208 | event->cpu = cpu; | |
c3f00c70 | 2209 | |
a096309b PZ |
2210 | if (!task) { |
2211 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2212 | return; | |
2213 | } | |
2214 | ||
2215 | /* | |
2216 | * Should not happen, we validate the ctx is still alive before calling. | |
2217 | */ | |
2218 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) | |
2219 | return; | |
2220 | ||
39a43640 PZ |
2221 | /* |
2222 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2223 | * to be set in case this is the nr_events 0 -> 1 transition. | |
39a43640 | 2224 | */ |
a096309b | 2225 | again: |
63b6da39 | 2226 | /* |
a096309b PZ |
2227 | * Cannot use task_function_call() because we need to run on the task's |
2228 | * CPU regardless of whether its current or not. | |
63b6da39 | 2229 | */ |
a096309b PZ |
2230 | if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event)) |
2231 | return; | |
2232 | ||
2233 | raw_spin_lock_irq(&ctx->lock); | |
2234 | task = ctx->task; | |
84c4e620 | 2235 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
a096309b PZ |
2236 | /* |
2237 | * Cannot happen because we already checked above (which also | |
2238 | * cannot happen), and we hold ctx->mutex, which serializes us | |
2239 | * against perf_event_exit_task_context(). | |
2240 | */ | |
63b6da39 PZ |
2241 | raw_spin_unlock_irq(&ctx->lock); |
2242 | return; | |
2243 | } | |
39a43640 | 2244 | raw_spin_unlock_irq(&ctx->lock); |
39a43640 | 2245 | /* |
a096309b PZ |
2246 | * Since !ctx->is_active doesn't mean anything, we must IPI |
2247 | * unconditionally. | |
39a43640 | 2248 | */ |
a096309b | 2249 | goto again; |
0793a61d TG |
2250 | } |
2251 | ||
fa289bec | 2252 | /* |
cdd6c482 | 2253 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2254 | * Enabling the leader of a group effectively enables all |
2255 | * the group members that aren't explicitly disabled, so we | |
2256 | * have to update their ->tstamp_enabled also. | |
2257 | * Note: this works for group members as well as group leaders | |
2258 | * since the non-leader members' sibling_lists will be empty. | |
2259 | */ | |
1d9b482e | 2260 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2261 | { |
cdd6c482 | 2262 | struct perf_event *sub; |
4158755d | 2263 | u64 tstamp = perf_event_time(event); |
fa289bec | 2264 | |
cdd6c482 | 2265 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2266 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2267 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2268 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2269 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2270 | } |
fa289bec PM |
2271 | } |
2272 | ||
d859e29f | 2273 | /* |
cdd6c482 | 2274 | * Cross CPU call to enable a performance event |
d859e29f | 2275 | */ |
fae3fde6 PZ |
2276 | static void __perf_event_enable(struct perf_event *event, |
2277 | struct perf_cpu_context *cpuctx, | |
2278 | struct perf_event_context *ctx, | |
2279 | void *info) | |
04289bb9 | 2280 | { |
cdd6c482 | 2281 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2282 | struct perf_event_context *task_ctx; |
04289bb9 | 2283 | |
6e801e01 PZ |
2284 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2285 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2286 | return; |
3cbed429 | 2287 | |
bd2afa49 PZ |
2288 | if (ctx->is_active) |
2289 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2290 | ||
1d9b482e | 2291 | __perf_event_mark_enabled(event); |
04289bb9 | 2292 | |
fae3fde6 PZ |
2293 | if (!ctx->is_active) |
2294 | return; | |
2295 | ||
e5d1367f | 2296 | if (!event_filter_match(event)) { |
bd2afa49 | 2297 | if (is_cgroup_event(event)) |
e5d1367f | 2298 | perf_cgroup_defer_enabled(event); |
bd2afa49 | 2299 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); |
fae3fde6 | 2300 | return; |
e5d1367f | 2301 | } |
f4c4176f | 2302 | |
04289bb9 | 2303 | /* |
cdd6c482 | 2304 | * If the event is in a group and isn't the group leader, |
d859e29f | 2305 | * then don't put it on unless the group is on. |
04289bb9 | 2306 | */ |
bd2afa49 PZ |
2307 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) { |
2308 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
fae3fde6 | 2309 | return; |
bd2afa49 | 2310 | } |
fe4b04fa | 2311 | |
fae3fde6 PZ |
2312 | task_ctx = cpuctx->task_ctx; |
2313 | if (ctx->task) | |
2314 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2315 | |
fae3fde6 | 2316 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2317 | } |
2318 | ||
d859e29f | 2319 | /* |
cdd6c482 | 2320 | * Enable a event. |
c93f7669 | 2321 | * |
cdd6c482 IM |
2322 | * If event->ctx is a cloned context, callers must make sure that |
2323 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2324 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2325 | * perf_event_for_each_child or perf_event_for_each as described |
2326 | * for perf_event_disable. | |
d859e29f | 2327 | */ |
f63a8daa | 2328 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2329 | { |
cdd6c482 | 2330 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2331 | |
7b648018 | 2332 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2333 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2334 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2335 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2336 | return; |
2337 | } | |
2338 | ||
d859e29f | 2339 | /* |
cdd6c482 | 2340 | * If the event is in error state, clear that first. |
7b648018 PZ |
2341 | * |
2342 | * That way, if we see the event in error state below, we know that it | |
2343 | * has gone back into error state, as distinct from the task having | |
2344 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2345 | */ |
cdd6c482 IM |
2346 | if (event->state == PERF_EVENT_STATE_ERROR) |
2347 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2348 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2349 | |
fae3fde6 | 2350 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2351 | } |
f63a8daa PZ |
2352 | |
2353 | /* | |
2354 | * See perf_event_disable(); | |
2355 | */ | |
2356 | void perf_event_enable(struct perf_event *event) | |
2357 | { | |
2358 | struct perf_event_context *ctx; | |
2359 | ||
2360 | ctx = perf_event_ctx_lock(event); | |
2361 | _perf_event_enable(event); | |
2362 | perf_event_ctx_unlock(event, ctx); | |
2363 | } | |
dcfce4a0 | 2364 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2365 | |
95ff4ca2 AS |
2366 | static int __perf_event_stop(void *info) |
2367 | { | |
2368 | struct perf_event *event = info; | |
2369 | ||
2370 | /* for AUX events, our job is done if the event is already inactive */ | |
2371 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) | |
2372 | return 0; | |
2373 | ||
2374 | /* matches smp_wmb() in event_sched_in() */ | |
2375 | smp_rmb(); | |
2376 | ||
2377 | /* | |
2378 | * There is a window with interrupts enabled before we get here, | |
2379 | * so we need to check again lest we try to stop another CPU's event. | |
2380 | */ | |
2381 | if (READ_ONCE(event->oncpu) != smp_processor_id()) | |
2382 | return -EAGAIN; | |
2383 | ||
2384 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2385 | ||
2386 | return 0; | |
2387 | } | |
2388 | ||
f63a8daa | 2389 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2390 | { |
2023b359 | 2391 | /* |
cdd6c482 | 2392 | * not supported on inherited events |
2023b359 | 2393 | */ |
2e939d1d | 2394 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2395 | return -EINVAL; |
2396 | ||
cdd6c482 | 2397 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2398 | _perf_event_enable(event); |
2023b359 PZ |
2399 | |
2400 | return 0; | |
79f14641 | 2401 | } |
f63a8daa PZ |
2402 | |
2403 | /* | |
2404 | * See perf_event_disable() | |
2405 | */ | |
2406 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2407 | { | |
2408 | struct perf_event_context *ctx; | |
2409 | int ret; | |
2410 | ||
2411 | ctx = perf_event_ctx_lock(event); | |
2412 | ret = _perf_event_refresh(event, refresh); | |
2413 | perf_event_ctx_unlock(event, ctx); | |
2414 | ||
2415 | return ret; | |
2416 | } | |
26ca5c11 | 2417 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2418 | |
5b0311e1 FW |
2419 | static void ctx_sched_out(struct perf_event_context *ctx, |
2420 | struct perf_cpu_context *cpuctx, | |
2421 | enum event_type_t event_type) | |
235c7fc7 | 2422 | { |
db24d33e | 2423 | int is_active = ctx->is_active; |
c994d613 | 2424 | struct perf_event *event; |
235c7fc7 | 2425 | |
c994d613 | 2426 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2427 | |
39a43640 PZ |
2428 | if (likely(!ctx->nr_events)) { |
2429 | /* | |
2430 | * See __perf_remove_from_context(). | |
2431 | */ | |
2432 | WARN_ON_ONCE(ctx->is_active); | |
2433 | if (ctx->task) | |
2434 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2435 | return; |
39a43640 PZ |
2436 | } |
2437 | ||
db24d33e | 2438 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2439 | if (!(ctx->is_active & EVENT_ALL)) |
2440 | ctx->is_active = 0; | |
2441 | ||
63e30d3e PZ |
2442 | if (ctx->task) { |
2443 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2444 | if (!ctx->is_active) | |
2445 | cpuctx->task_ctx = NULL; | |
2446 | } | |
facc4307 | 2447 | |
8fdc6539 PZ |
2448 | /* |
2449 | * Always update time if it was set; not only when it changes. | |
2450 | * Otherwise we can 'forget' to update time for any but the last | |
2451 | * context we sched out. For example: | |
2452 | * | |
2453 | * ctx_sched_out(.event_type = EVENT_FLEXIBLE) | |
2454 | * ctx_sched_out(.event_type = EVENT_PINNED) | |
2455 | * | |
2456 | * would only update time for the pinned events. | |
2457 | */ | |
3cbaa590 PZ |
2458 | if (is_active & EVENT_TIME) { |
2459 | /* update (and stop) ctx time */ | |
2460 | update_context_time(ctx); | |
2461 | update_cgrp_time_from_cpuctx(cpuctx); | |
2462 | } | |
2463 | ||
8fdc6539 PZ |
2464 | is_active ^= ctx->is_active; /* changed bits */ |
2465 | ||
3cbaa590 | 2466 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) |
facc4307 | 2467 | return; |
5b0311e1 | 2468 | |
075e0b00 | 2469 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2470 | if (is_active & EVENT_PINNED) { |
889ff015 FW |
2471 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2472 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2473 | } |
889ff015 | 2474 | |
3cbaa590 | 2475 | if (is_active & EVENT_FLEXIBLE) { |
889ff015 | 2476 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2477 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2478 | } |
1b9a644f | 2479 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2480 | } |
2481 | ||
564c2b21 | 2482 | /* |
5a3126d4 PZ |
2483 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2484 | * cloned from the same version of the same context. | |
2485 | * | |
2486 | * Equivalence is measured using a generation number in the context that is | |
2487 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2488 | * and list_del_event(). | |
564c2b21 | 2489 | */ |
cdd6c482 IM |
2490 | static int context_equiv(struct perf_event_context *ctx1, |
2491 | struct perf_event_context *ctx2) | |
564c2b21 | 2492 | { |
211de6eb PZ |
2493 | lockdep_assert_held(&ctx1->lock); |
2494 | lockdep_assert_held(&ctx2->lock); | |
2495 | ||
5a3126d4 PZ |
2496 | /* Pinning disables the swap optimization */ |
2497 | if (ctx1->pin_count || ctx2->pin_count) | |
2498 | return 0; | |
2499 | ||
2500 | /* If ctx1 is the parent of ctx2 */ | |
2501 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2502 | return 1; | |
2503 | ||
2504 | /* If ctx2 is the parent of ctx1 */ | |
2505 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2506 | return 1; | |
2507 | ||
2508 | /* | |
2509 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2510 | * hierarchy, see perf_event_init_context(). | |
2511 | */ | |
2512 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2513 | ctx1->parent_gen == ctx2->parent_gen) | |
2514 | return 1; | |
2515 | ||
2516 | /* Unmatched */ | |
2517 | return 0; | |
564c2b21 PM |
2518 | } |
2519 | ||
cdd6c482 IM |
2520 | static void __perf_event_sync_stat(struct perf_event *event, |
2521 | struct perf_event *next_event) | |
bfbd3381 PZ |
2522 | { |
2523 | u64 value; | |
2524 | ||
cdd6c482 | 2525 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2526 | return; |
2527 | ||
2528 | /* | |
cdd6c482 | 2529 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2530 | * because we're in the middle of a context switch and have IRQs |
2531 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2532 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2533 | * don't need to use it. |
2534 | */ | |
cdd6c482 IM |
2535 | switch (event->state) { |
2536 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2537 | event->pmu->read(event); |
2538 | /* fall-through */ | |
bfbd3381 | 2539 | |
cdd6c482 IM |
2540 | case PERF_EVENT_STATE_INACTIVE: |
2541 | update_event_times(event); | |
bfbd3381 PZ |
2542 | break; |
2543 | ||
2544 | default: | |
2545 | break; | |
2546 | } | |
2547 | ||
2548 | /* | |
cdd6c482 | 2549 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2550 | * values when we flip the contexts. |
2551 | */ | |
e7850595 PZ |
2552 | value = local64_read(&next_event->count); |
2553 | value = local64_xchg(&event->count, value); | |
2554 | local64_set(&next_event->count, value); | |
bfbd3381 | 2555 | |
cdd6c482 IM |
2556 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2557 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2558 | |
bfbd3381 | 2559 | /* |
19d2e755 | 2560 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2561 | */ |
cdd6c482 IM |
2562 | perf_event_update_userpage(event); |
2563 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2564 | } |
2565 | ||
cdd6c482 IM |
2566 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2567 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2568 | { |
cdd6c482 | 2569 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2570 | |
2571 | if (!ctx->nr_stat) | |
2572 | return; | |
2573 | ||
02ffdbc8 PZ |
2574 | update_context_time(ctx); |
2575 | ||
cdd6c482 IM |
2576 | event = list_first_entry(&ctx->event_list, |
2577 | struct perf_event, event_entry); | |
bfbd3381 | 2578 | |
cdd6c482 IM |
2579 | next_event = list_first_entry(&next_ctx->event_list, |
2580 | struct perf_event, event_entry); | |
bfbd3381 | 2581 | |
cdd6c482 IM |
2582 | while (&event->event_entry != &ctx->event_list && |
2583 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2584 | |
cdd6c482 | 2585 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2586 | |
cdd6c482 IM |
2587 | event = list_next_entry(event, event_entry); |
2588 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2589 | } |
2590 | } | |
2591 | ||
fe4b04fa PZ |
2592 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2593 | struct task_struct *next) | |
0793a61d | 2594 | { |
8dc85d54 | 2595 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2596 | struct perf_event_context *next_ctx; |
5a3126d4 | 2597 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2598 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2599 | int do_switch = 1; |
0793a61d | 2600 | |
108b02cf PZ |
2601 | if (likely(!ctx)) |
2602 | return; | |
10989fb2 | 2603 | |
108b02cf PZ |
2604 | cpuctx = __get_cpu_context(ctx); |
2605 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2606 | return; |
2607 | ||
c93f7669 | 2608 | rcu_read_lock(); |
8dc85d54 | 2609 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2610 | if (!next_ctx) |
2611 | goto unlock; | |
2612 | ||
2613 | parent = rcu_dereference(ctx->parent_ctx); | |
2614 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2615 | ||
2616 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2617 | if (!parent && !next_parent) |
5a3126d4 PZ |
2618 | goto unlock; |
2619 | ||
2620 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2621 | /* |
2622 | * Looks like the two contexts are clones, so we might be | |
2623 | * able to optimize the context switch. We lock both | |
2624 | * contexts and check that they are clones under the | |
2625 | * lock (including re-checking that neither has been | |
2626 | * uncloned in the meantime). It doesn't matter which | |
2627 | * order we take the locks because no other cpu could | |
2628 | * be trying to lock both of these tasks. | |
2629 | */ | |
e625cce1 TG |
2630 | raw_spin_lock(&ctx->lock); |
2631 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2632 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2633 | WRITE_ONCE(ctx->task, next); |
2634 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2635 | |
2636 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2637 | ||
63b6da39 PZ |
2638 | /* |
2639 | * RCU_INIT_POINTER here is safe because we've not | |
2640 | * modified the ctx and the above modification of | |
2641 | * ctx->task and ctx->task_ctx_data are immaterial | |
2642 | * since those values are always verified under | |
2643 | * ctx->lock which we're now holding. | |
2644 | */ | |
2645 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2646 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2647 | ||
c93f7669 | 2648 | do_switch = 0; |
bfbd3381 | 2649 | |
cdd6c482 | 2650 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2651 | } |
e625cce1 TG |
2652 | raw_spin_unlock(&next_ctx->lock); |
2653 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2654 | } |
5a3126d4 | 2655 | unlock: |
c93f7669 | 2656 | rcu_read_unlock(); |
564c2b21 | 2657 | |
c93f7669 | 2658 | if (do_switch) { |
facc4307 | 2659 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2660 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2661 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2662 | } |
0793a61d TG |
2663 | } |
2664 | ||
ba532500 YZ |
2665 | void perf_sched_cb_dec(struct pmu *pmu) |
2666 | { | |
2667 | this_cpu_dec(perf_sched_cb_usages); | |
2668 | } | |
2669 | ||
2670 | void perf_sched_cb_inc(struct pmu *pmu) | |
2671 | { | |
2672 | this_cpu_inc(perf_sched_cb_usages); | |
2673 | } | |
2674 | ||
2675 | /* | |
2676 | * This function provides the context switch callback to the lower code | |
2677 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2678 | */ | |
2679 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2680 | struct task_struct *next, | |
2681 | bool sched_in) | |
2682 | { | |
2683 | struct perf_cpu_context *cpuctx; | |
2684 | struct pmu *pmu; | |
2685 | unsigned long flags; | |
2686 | ||
2687 | if (prev == next) | |
2688 | return; | |
2689 | ||
2690 | local_irq_save(flags); | |
2691 | ||
2692 | rcu_read_lock(); | |
2693 | ||
2694 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2695 | if (pmu->sched_task) { | |
2696 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2697 | ||
2698 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2699 | ||
2700 | perf_pmu_disable(pmu); | |
2701 | ||
2702 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2703 | ||
2704 | perf_pmu_enable(pmu); | |
2705 | ||
2706 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2707 | } | |
2708 | } | |
2709 | ||
2710 | rcu_read_unlock(); | |
2711 | ||
2712 | local_irq_restore(flags); | |
2713 | } | |
2714 | ||
45ac1403 AH |
2715 | static void perf_event_switch(struct task_struct *task, |
2716 | struct task_struct *next_prev, bool sched_in); | |
2717 | ||
8dc85d54 PZ |
2718 | #define for_each_task_context_nr(ctxn) \ |
2719 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2720 | ||
2721 | /* | |
2722 | * Called from scheduler to remove the events of the current task, | |
2723 | * with interrupts disabled. | |
2724 | * | |
2725 | * We stop each event and update the event value in event->count. | |
2726 | * | |
2727 | * This does not protect us against NMI, but disable() | |
2728 | * sets the disabled bit in the control field of event _before_ | |
2729 | * accessing the event control register. If a NMI hits, then it will | |
2730 | * not restart the event. | |
2731 | */ | |
ab0cce56 JO |
2732 | void __perf_event_task_sched_out(struct task_struct *task, |
2733 | struct task_struct *next) | |
8dc85d54 PZ |
2734 | { |
2735 | int ctxn; | |
2736 | ||
ba532500 YZ |
2737 | if (__this_cpu_read(perf_sched_cb_usages)) |
2738 | perf_pmu_sched_task(task, next, false); | |
2739 | ||
45ac1403 AH |
2740 | if (atomic_read(&nr_switch_events)) |
2741 | perf_event_switch(task, next, false); | |
2742 | ||
8dc85d54 PZ |
2743 | for_each_task_context_nr(ctxn) |
2744 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2745 | |
2746 | /* | |
2747 | * if cgroup events exist on this CPU, then we need | |
2748 | * to check if we have to switch out PMU state. | |
2749 | * cgroup event are system-wide mode only | |
2750 | */ | |
4a32fea9 | 2751 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2752 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2753 | } |
2754 | ||
5b0311e1 FW |
2755 | /* |
2756 | * Called with IRQs disabled | |
2757 | */ | |
2758 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2759 | enum event_type_t event_type) | |
2760 | { | |
2761 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2762 | } |
2763 | ||
235c7fc7 | 2764 | static void |
5b0311e1 | 2765 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2766 | struct perf_cpu_context *cpuctx) |
0793a61d | 2767 | { |
cdd6c482 | 2768 | struct perf_event *event; |
0793a61d | 2769 | |
889ff015 FW |
2770 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2771 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2772 | continue; |
5632ab12 | 2773 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2774 | continue; |
2775 | ||
e5d1367f SE |
2776 | /* may need to reset tstamp_enabled */ |
2777 | if (is_cgroup_event(event)) | |
2778 | perf_cgroup_mark_enabled(event, ctx); | |
2779 | ||
8c9ed8e1 | 2780 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2781 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2782 | |
2783 | /* | |
2784 | * If this pinned group hasn't been scheduled, | |
2785 | * put it in error state. | |
2786 | */ | |
cdd6c482 IM |
2787 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2788 | update_group_times(event); | |
2789 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2790 | } |
3b6f9e5c | 2791 | } |
5b0311e1 FW |
2792 | } |
2793 | ||
2794 | static void | |
2795 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2796 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2797 | { |
2798 | struct perf_event *event; | |
2799 | int can_add_hw = 1; | |
3b6f9e5c | 2800 | |
889ff015 FW |
2801 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2802 | /* Ignore events in OFF or ERROR state */ | |
2803 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2804 | continue; |
04289bb9 IM |
2805 | /* |
2806 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2807 | * of events: |
04289bb9 | 2808 | */ |
5632ab12 | 2809 | if (!event_filter_match(event)) |
0793a61d TG |
2810 | continue; |
2811 | ||
e5d1367f SE |
2812 | /* may need to reset tstamp_enabled */ |
2813 | if (is_cgroup_event(event)) | |
2814 | perf_cgroup_mark_enabled(event, ctx); | |
2815 | ||
9ed6060d | 2816 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2817 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2818 | can_add_hw = 0; |
9ed6060d | 2819 | } |
0793a61d | 2820 | } |
5b0311e1 FW |
2821 | } |
2822 | ||
2823 | static void | |
2824 | ctx_sched_in(struct perf_event_context *ctx, | |
2825 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2826 | enum event_type_t event_type, |
2827 | struct task_struct *task) | |
5b0311e1 | 2828 | { |
db24d33e | 2829 | int is_active = ctx->is_active; |
c994d613 PZ |
2830 | u64 now; |
2831 | ||
2832 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2833 | |
5b0311e1 | 2834 | if (likely(!ctx->nr_events)) |
facc4307 | 2835 | return; |
5b0311e1 | 2836 | |
3cbaa590 | 2837 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
2838 | if (ctx->task) { |
2839 | if (!is_active) | |
2840 | cpuctx->task_ctx = ctx; | |
2841 | else | |
2842 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2843 | } | |
2844 | ||
3cbaa590 PZ |
2845 | is_active ^= ctx->is_active; /* changed bits */ |
2846 | ||
2847 | if (is_active & EVENT_TIME) { | |
2848 | /* start ctx time */ | |
2849 | now = perf_clock(); | |
2850 | ctx->timestamp = now; | |
2851 | perf_cgroup_set_timestamp(task, ctx); | |
2852 | } | |
2853 | ||
5b0311e1 FW |
2854 | /* |
2855 | * First go through the list and put on any pinned groups | |
2856 | * in order to give them the best chance of going on. | |
2857 | */ | |
3cbaa590 | 2858 | if (is_active & EVENT_PINNED) |
6e37738a | 2859 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2860 | |
2861 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 2862 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 2863 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2864 | } |
2865 | ||
329c0e01 | 2866 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2867 | enum event_type_t event_type, |
2868 | struct task_struct *task) | |
329c0e01 FW |
2869 | { |
2870 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2871 | ||
e5d1367f | 2872 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2873 | } |
2874 | ||
e5d1367f SE |
2875 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2876 | struct task_struct *task) | |
235c7fc7 | 2877 | { |
108b02cf | 2878 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2879 | |
108b02cf | 2880 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2881 | if (cpuctx->task_ctx == ctx) |
2882 | return; | |
2883 | ||
facc4307 | 2884 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2885 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2886 | /* |
2887 | * We want to keep the following priority order: | |
2888 | * cpu pinned (that don't need to move), task pinned, | |
2889 | * cpu flexible, task flexible. | |
2890 | */ | |
2891 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2892 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2893 | perf_pmu_enable(ctx->pmu); |
2894 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2895 | } |
2896 | ||
8dc85d54 PZ |
2897 | /* |
2898 | * Called from scheduler to add the events of the current task | |
2899 | * with interrupts disabled. | |
2900 | * | |
2901 | * We restore the event value and then enable it. | |
2902 | * | |
2903 | * This does not protect us against NMI, but enable() | |
2904 | * sets the enabled bit in the control field of event _before_ | |
2905 | * accessing the event control register. If a NMI hits, then it will | |
2906 | * keep the event running. | |
2907 | */ | |
ab0cce56 JO |
2908 | void __perf_event_task_sched_in(struct task_struct *prev, |
2909 | struct task_struct *task) | |
8dc85d54 PZ |
2910 | { |
2911 | struct perf_event_context *ctx; | |
2912 | int ctxn; | |
2913 | ||
7e41d177 PZ |
2914 | /* |
2915 | * If cgroup events exist on this CPU, then we need to check if we have | |
2916 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2917 | * | |
2918 | * Since cgroup events are CPU events, we must schedule these in before | |
2919 | * we schedule in the task events. | |
2920 | */ | |
2921 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2922 | perf_cgroup_sched_in(prev, task); | |
2923 | ||
8dc85d54 PZ |
2924 | for_each_task_context_nr(ctxn) { |
2925 | ctx = task->perf_event_ctxp[ctxn]; | |
2926 | if (likely(!ctx)) | |
2927 | continue; | |
2928 | ||
e5d1367f | 2929 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2930 | } |
d010b332 | 2931 | |
45ac1403 AH |
2932 | if (atomic_read(&nr_switch_events)) |
2933 | perf_event_switch(task, prev, true); | |
2934 | ||
ba532500 YZ |
2935 | if (__this_cpu_read(perf_sched_cb_usages)) |
2936 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2937 | } |
2938 | ||
abd50713 PZ |
2939 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2940 | { | |
2941 | u64 frequency = event->attr.sample_freq; | |
2942 | u64 sec = NSEC_PER_SEC; | |
2943 | u64 divisor, dividend; | |
2944 | ||
2945 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2946 | ||
2947 | count_fls = fls64(count); | |
2948 | nsec_fls = fls64(nsec); | |
2949 | frequency_fls = fls64(frequency); | |
2950 | sec_fls = 30; | |
2951 | ||
2952 | /* | |
2953 | * We got @count in @nsec, with a target of sample_freq HZ | |
2954 | * the target period becomes: | |
2955 | * | |
2956 | * @count * 10^9 | |
2957 | * period = ------------------- | |
2958 | * @nsec * sample_freq | |
2959 | * | |
2960 | */ | |
2961 | ||
2962 | /* | |
2963 | * Reduce accuracy by one bit such that @a and @b converge | |
2964 | * to a similar magnitude. | |
2965 | */ | |
fe4b04fa | 2966 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2967 | do { \ |
2968 | if (a##_fls > b##_fls) { \ | |
2969 | a >>= 1; \ | |
2970 | a##_fls--; \ | |
2971 | } else { \ | |
2972 | b >>= 1; \ | |
2973 | b##_fls--; \ | |
2974 | } \ | |
2975 | } while (0) | |
2976 | ||
2977 | /* | |
2978 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2979 | * the other, so that finally we can do a u64/u64 division. | |
2980 | */ | |
2981 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2982 | REDUCE_FLS(nsec, frequency); | |
2983 | REDUCE_FLS(sec, count); | |
2984 | } | |
2985 | ||
2986 | if (count_fls + sec_fls > 64) { | |
2987 | divisor = nsec * frequency; | |
2988 | ||
2989 | while (count_fls + sec_fls > 64) { | |
2990 | REDUCE_FLS(count, sec); | |
2991 | divisor >>= 1; | |
2992 | } | |
2993 | ||
2994 | dividend = count * sec; | |
2995 | } else { | |
2996 | dividend = count * sec; | |
2997 | ||
2998 | while (nsec_fls + frequency_fls > 64) { | |
2999 | REDUCE_FLS(nsec, frequency); | |
3000 | dividend >>= 1; | |
3001 | } | |
3002 | ||
3003 | divisor = nsec * frequency; | |
3004 | } | |
3005 | ||
f6ab91ad PZ |
3006 | if (!divisor) |
3007 | return dividend; | |
3008 | ||
abd50713 PZ |
3009 | return div64_u64(dividend, divisor); |
3010 | } | |
3011 | ||
e050e3f0 SE |
3012 | static DEFINE_PER_CPU(int, perf_throttled_count); |
3013 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
3014 | ||
f39d47ff | 3015 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 3016 | { |
cdd6c482 | 3017 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 3018 | s64 period, sample_period; |
bd2b5b12 PZ |
3019 | s64 delta; |
3020 | ||
abd50713 | 3021 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
3022 | |
3023 | delta = (s64)(period - hwc->sample_period); | |
3024 | delta = (delta + 7) / 8; /* low pass filter */ | |
3025 | ||
3026 | sample_period = hwc->sample_period + delta; | |
3027 | ||
3028 | if (!sample_period) | |
3029 | sample_period = 1; | |
3030 | ||
bd2b5b12 | 3031 | hwc->sample_period = sample_period; |
abd50713 | 3032 | |
e7850595 | 3033 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
3034 | if (disable) |
3035 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3036 | ||
e7850595 | 3037 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
3038 | |
3039 | if (disable) | |
3040 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 3041 | } |
bd2b5b12 PZ |
3042 | } |
3043 | ||
e050e3f0 SE |
3044 | /* |
3045 | * combine freq adjustment with unthrottling to avoid two passes over the | |
3046 | * events. At the same time, make sure, having freq events does not change | |
3047 | * the rate of unthrottling as that would introduce bias. | |
3048 | */ | |
3049 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
3050 | int needs_unthr) | |
60db5e09 | 3051 | { |
cdd6c482 IM |
3052 | struct perf_event *event; |
3053 | struct hw_perf_event *hwc; | |
e050e3f0 | 3054 | u64 now, period = TICK_NSEC; |
abd50713 | 3055 | s64 delta; |
60db5e09 | 3056 | |
e050e3f0 SE |
3057 | /* |
3058 | * only need to iterate over all events iff: | |
3059 | * - context have events in frequency mode (needs freq adjust) | |
3060 | * - there are events to unthrottle on this cpu | |
3061 | */ | |
3062 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
3063 | return; |
3064 | ||
e050e3f0 | 3065 | raw_spin_lock(&ctx->lock); |
f39d47ff | 3066 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 3067 | |
03541f8b | 3068 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 3069 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
3070 | continue; |
3071 | ||
5632ab12 | 3072 | if (!event_filter_match(event)) |
5d27c23d PZ |
3073 | continue; |
3074 | ||
44377277 AS |
3075 | perf_pmu_disable(event->pmu); |
3076 | ||
cdd6c482 | 3077 | hwc = &event->hw; |
6a24ed6c | 3078 | |
ae23bff1 | 3079 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 3080 | hwc->interrupts = 0; |
cdd6c482 | 3081 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3082 | event->pmu->start(event, 0); |
a78ac325 PZ |
3083 | } |
3084 | ||
cdd6c482 | 3085 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3086 | goto next; |
60db5e09 | 3087 | |
e050e3f0 SE |
3088 | /* |
3089 | * stop the event and update event->count | |
3090 | */ | |
3091 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3092 | ||
e7850595 | 3093 | now = local64_read(&event->count); |
abd50713 PZ |
3094 | delta = now - hwc->freq_count_stamp; |
3095 | hwc->freq_count_stamp = now; | |
60db5e09 | 3096 | |
e050e3f0 SE |
3097 | /* |
3098 | * restart the event | |
3099 | * reload only if value has changed | |
f39d47ff SE |
3100 | * we have stopped the event so tell that |
3101 | * to perf_adjust_period() to avoid stopping it | |
3102 | * twice. | |
e050e3f0 | 3103 | */ |
abd50713 | 3104 | if (delta > 0) |
f39d47ff | 3105 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3106 | |
3107 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3108 | next: |
3109 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3110 | } |
e050e3f0 | 3111 | |
f39d47ff | 3112 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3113 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3114 | } |
3115 | ||
235c7fc7 | 3116 | /* |
cdd6c482 | 3117 | * Round-robin a context's events: |
235c7fc7 | 3118 | */ |
cdd6c482 | 3119 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3120 | { |
dddd3379 TG |
3121 | /* |
3122 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3123 | * disabled by the inheritance code. | |
3124 | */ | |
3125 | if (!ctx->rotate_disable) | |
3126 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3127 | } |
3128 | ||
9e630205 | 3129 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3130 | { |
8dc85d54 | 3131 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3132 | int rotate = 0; |
7fc23a53 | 3133 | |
b5ab4cd5 | 3134 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3135 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3136 | rotate = 1; | |
3137 | } | |
235c7fc7 | 3138 | |
8dc85d54 | 3139 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3140 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3141 | if (ctx->nr_events != ctx->nr_active) |
3142 | rotate = 1; | |
3143 | } | |
9717e6cd | 3144 | |
e050e3f0 | 3145 | if (!rotate) |
0f5a2601 PZ |
3146 | goto done; |
3147 | ||
facc4307 | 3148 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3149 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3150 | |
e050e3f0 SE |
3151 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3152 | if (ctx) | |
3153 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3154 | |
e050e3f0 SE |
3155 | rotate_ctx(&cpuctx->ctx); |
3156 | if (ctx) | |
3157 | rotate_ctx(ctx); | |
235c7fc7 | 3158 | |
e050e3f0 | 3159 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3160 | |
0f5a2601 PZ |
3161 | perf_pmu_enable(cpuctx->ctx.pmu); |
3162 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3163 | done: |
9e630205 SE |
3164 | |
3165 | return rotate; | |
e9d2b064 PZ |
3166 | } |
3167 | ||
3168 | void perf_event_task_tick(void) | |
3169 | { | |
2fde4f94 MR |
3170 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3171 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3172 | int throttled; |
b5ab4cd5 | 3173 | |
e9d2b064 PZ |
3174 | WARN_ON(!irqs_disabled()); |
3175 | ||
e050e3f0 SE |
3176 | __this_cpu_inc(perf_throttled_seq); |
3177 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
555e0c1e | 3178 | tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
e050e3f0 | 3179 | |
2fde4f94 | 3180 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3181 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3182 | } |
3183 | ||
889ff015 FW |
3184 | static int event_enable_on_exec(struct perf_event *event, |
3185 | struct perf_event_context *ctx) | |
3186 | { | |
3187 | if (!event->attr.enable_on_exec) | |
3188 | return 0; | |
3189 | ||
3190 | event->attr.enable_on_exec = 0; | |
3191 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3192 | return 0; | |
3193 | ||
1d9b482e | 3194 | __perf_event_mark_enabled(event); |
889ff015 FW |
3195 | |
3196 | return 1; | |
3197 | } | |
3198 | ||
57e7986e | 3199 | /* |
cdd6c482 | 3200 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3201 | * This expects task == current. |
3202 | */ | |
c1274499 | 3203 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3204 | { |
c1274499 | 3205 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3206 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3207 | struct perf_event *event; |
57e7986e PM |
3208 | unsigned long flags; |
3209 | int enabled = 0; | |
3210 | ||
3211 | local_irq_save(flags); | |
c1274499 | 3212 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3213 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3214 | goto out; |
3215 | ||
3e349507 PZ |
3216 | cpuctx = __get_cpu_context(ctx); |
3217 | perf_ctx_lock(cpuctx, ctx); | |
7fce2509 | 3218 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
3e349507 PZ |
3219 | list_for_each_entry(event, &ctx->event_list, event_entry) |
3220 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3221 | |
3222 | /* | |
3e349507 | 3223 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3224 | */ |
3e349507 | 3225 | if (enabled) { |
211de6eb | 3226 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3227 | ctx_resched(cpuctx, ctx); |
3228 | } | |
3229 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3230 | |
9ed6060d | 3231 | out: |
57e7986e | 3232 | local_irq_restore(flags); |
211de6eb PZ |
3233 | |
3234 | if (clone_ctx) | |
3235 | put_ctx(clone_ctx); | |
57e7986e PM |
3236 | } |
3237 | ||
e041e328 PZ |
3238 | void perf_event_exec(void) |
3239 | { | |
e041e328 PZ |
3240 | int ctxn; |
3241 | ||
3242 | rcu_read_lock(); | |
c1274499 PZ |
3243 | for_each_task_context_nr(ctxn) |
3244 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3245 | rcu_read_unlock(); |
3246 | } | |
3247 | ||
0492d4c5 PZ |
3248 | struct perf_read_data { |
3249 | struct perf_event *event; | |
3250 | bool group; | |
7d88962e | 3251 | int ret; |
0492d4c5 PZ |
3252 | }; |
3253 | ||
0793a61d | 3254 | /* |
cdd6c482 | 3255 | * Cross CPU call to read the hardware event |
0793a61d | 3256 | */ |
cdd6c482 | 3257 | static void __perf_event_read(void *info) |
0793a61d | 3258 | { |
0492d4c5 PZ |
3259 | struct perf_read_data *data = info; |
3260 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3261 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3262 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3263 | struct pmu *pmu = event->pmu; |
621a01ea | 3264 | |
e1ac3614 PM |
3265 | /* |
3266 | * If this is a task context, we need to check whether it is | |
3267 | * the current task context of this cpu. If not it has been | |
3268 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3269 | * event->count would have been updated to a recent sample |
3270 | * when the event was scheduled out. | |
e1ac3614 PM |
3271 | */ |
3272 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3273 | return; | |
3274 | ||
e625cce1 | 3275 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3276 | if (ctx->is_active) { |
542e72fc | 3277 | update_context_time(ctx); |
e5d1367f SE |
3278 | update_cgrp_time_from_event(event); |
3279 | } | |
0492d4c5 | 3280 | |
cdd6c482 | 3281 | update_event_times(event); |
4a00c16e SB |
3282 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3283 | goto unlock; | |
0492d4c5 | 3284 | |
4a00c16e SB |
3285 | if (!data->group) { |
3286 | pmu->read(event); | |
3287 | data->ret = 0; | |
0492d4c5 | 3288 | goto unlock; |
4a00c16e SB |
3289 | } |
3290 | ||
3291 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3292 | ||
3293 | pmu->read(event); | |
0492d4c5 PZ |
3294 | |
3295 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3296 | update_event_times(sub); | |
4a00c16e SB |
3297 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3298 | /* | |
3299 | * Use sibling's PMU rather than @event's since | |
3300 | * sibling could be on different (eg: software) PMU. | |
3301 | */ | |
0492d4c5 | 3302 | sub->pmu->read(sub); |
4a00c16e | 3303 | } |
0492d4c5 | 3304 | } |
4a00c16e SB |
3305 | |
3306 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3307 | |
3308 | unlock: | |
e625cce1 | 3309 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3310 | } |
3311 | ||
b5e58793 PZ |
3312 | static inline u64 perf_event_count(struct perf_event *event) |
3313 | { | |
eacd3ecc MF |
3314 | if (event->pmu->count) |
3315 | return event->pmu->count(event); | |
3316 | ||
3317 | return __perf_event_count(event); | |
b5e58793 PZ |
3318 | } |
3319 | ||
ffe8690c KX |
3320 | /* |
3321 | * NMI-safe method to read a local event, that is an event that | |
3322 | * is: | |
3323 | * - either for the current task, or for this CPU | |
3324 | * - does not have inherit set, for inherited task events | |
3325 | * will not be local and we cannot read them atomically | |
3326 | * - must not have a pmu::count method | |
3327 | */ | |
3328 | u64 perf_event_read_local(struct perf_event *event) | |
3329 | { | |
3330 | unsigned long flags; | |
3331 | u64 val; | |
3332 | ||
3333 | /* | |
3334 | * Disabling interrupts avoids all counter scheduling (context | |
3335 | * switches, timer based rotation and IPIs). | |
3336 | */ | |
3337 | local_irq_save(flags); | |
3338 | ||
3339 | /* If this is a per-task event, it must be for current */ | |
3340 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3341 | event->hw.target != current); | |
3342 | ||
3343 | /* If this is a per-CPU event, it must be for this CPU */ | |
3344 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3345 | event->cpu != smp_processor_id()); | |
3346 | ||
3347 | /* | |
3348 | * It must not be an event with inherit set, we cannot read | |
3349 | * all child counters from atomic context. | |
3350 | */ | |
3351 | WARN_ON_ONCE(event->attr.inherit); | |
3352 | ||
3353 | /* | |
3354 | * It must not have a pmu::count method, those are not | |
3355 | * NMI safe. | |
3356 | */ | |
3357 | WARN_ON_ONCE(event->pmu->count); | |
3358 | ||
3359 | /* | |
3360 | * If the event is currently on this CPU, its either a per-task event, | |
3361 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3362 | * oncpu == -1). | |
3363 | */ | |
3364 | if (event->oncpu == smp_processor_id()) | |
3365 | event->pmu->read(event); | |
3366 | ||
3367 | val = local64_read(&event->count); | |
3368 | local_irq_restore(flags); | |
3369 | ||
3370 | return val; | |
3371 | } | |
3372 | ||
7d88962e | 3373 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3374 | { |
7d88962e SB |
3375 | int ret = 0; |
3376 | ||
0793a61d | 3377 | /* |
cdd6c482 IM |
3378 | * If event is enabled and currently active on a CPU, update the |
3379 | * value in the event structure: | |
0793a61d | 3380 | */ |
cdd6c482 | 3381 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3382 | struct perf_read_data data = { |
3383 | .event = event, | |
3384 | .group = group, | |
7d88962e | 3385 | .ret = 0, |
0492d4c5 | 3386 | }; |
cdd6c482 | 3387 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3388 | __perf_event_read, &data, 1); |
7d88962e | 3389 | ret = data.ret; |
cdd6c482 | 3390 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3391 | struct perf_event_context *ctx = event->ctx; |
3392 | unsigned long flags; | |
3393 | ||
e625cce1 | 3394 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3395 | /* |
3396 | * may read while context is not active | |
3397 | * (e.g., thread is blocked), in that case | |
3398 | * we cannot update context time | |
3399 | */ | |
e5d1367f | 3400 | if (ctx->is_active) { |
c530ccd9 | 3401 | update_context_time(ctx); |
e5d1367f SE |
3402 | update_cgrp_time_from_event(event); |
3403 | } | |
0492d4c5 PZ |
3404 | if (group) |
3405 | update_group_times(event); | |
3406 | else | |
3407 | update_event_times(event); | |
e625cce1 | 3408 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3409 | } |
7d88962e SB |
3410 | |
3411 | return ret; | |
0793a61d TG |
3412 | } |
3413 | ||
a63eaf34 | 3414 | /* |
cdd6c482 | 3415 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3416 | */ |
eb184479 | 3417 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3418 | { |
e625cce1 | 3419 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3420 | mutex_init(&ctx->mutex); |
2fde4f94 | 3421 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3422 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3423 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3424 | INIT_LIST_HEAD(&ctx->event_list); |
3425 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3426 | } |
3427 | ||
3428 | static struct perf_event_context * | |
3429 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3430 | { | |
3431 | struct perf_event_context *ctx; | |
3432 | ||
3433 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3434 | if (!ctx) | |
3435 | return NULL; | |
3436 | ||
3437 | __perf_event_init_context(ctx); | |
3438 | if (task) { | |
3439 | ctx->task = task; | |
3440 | get_task_struct(task); | |
0793a61d | 3441 | } |
eb184479 PZ |
3442 | ctx->pmu = pmu; |
3443 | ||
3444 | return ctx; | |
a63eaf34 PM |
3445 | } |
3446 | ||
2ebd4ffb MH |
3447 | static struct task_struct * |
3448 | find_lively_task_by_vpid(pid_t vpid) | |
3449 | { | |
3450 | struct task_struct *task; | |
3451 | int err; | |
0793a61d TG |
3452 | |
3453 | rcu_read_lock(); | |
2ebd4ffb | 3454 | if (!vpid) |
0793a61d TG |
3455 | task = current; |
3456 | else | |
2ebd4ffb | 3457 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3458 | if (task) |
3459 | get_task_struct(task); | |
3460 | rcu_read_unlock(); | |
3461 | ||
3462 | if (!task) | |
3463 | return ERR_PTR(-ESRCH); | |
3464 | ||
0793a61d | 3465 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3466 | err = -EACCES; |
caaee623 | 3467 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3468 | goto errout; |
3469 | ||
2ebd4ffb MH |
3470 | return task; |
3471 | errout: | |
3472 | put_task_struct(task); | |
3473 | return ERR_PTR(err); | |
3474 | ||
3475 | } | |
3476 | ||
fe4b04fa PZ |
3477 | /* |
3478 | * Returns a matching context with refcount and pincount. | |
3479 | */ | |
108b02cf | 3480 | static struct perf_event_context * |
4af57ef2 YZ |
3481 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3482 | struct perf_event *event) | |
0793a61d | 3483 | { |
211de6eb | 3484 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3485 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3486 | void *task_ctx_data = NULL; |
25346b93 | 3487 | unsigned long flags; |
8dc85d54 | 3488 | int ctxn, err; |
4af57ef2 | 3489 | int cpu = event->cpu; |
0793a61d | 3490 | |
22a4ec72 | 3491 | if (!task) { |
cdd6c482 | 3492 | /* Must be root to operate on a CPU event: */ |
0764771d | 3493 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3494 | return ERR_PTR(-EACCES); |
3495 | ||
0793a61d | 3496 | /* |
cdd6c482 | 3497 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3498 | * offline CPU and activate it when the CPU comes up, but |
3499 | * that's for later. | |
3500 | */ | |
f6325e30 | 3501 | if (!cpu_online(cpu)) |
0793a61d TG |
3502 | return ERR_PTR(-ENODEV); |
3503 | ||
108b02cf | 3504 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3505 | ctx = &cpuctx->ctx; |
c93f7669 | 3506 | get_ctx(ctx); |
fe4b04fa | 3507 | ++ctx->pin_count; |
0793a61d | 3508 | |
0793a61d TG |
3509 | return ctx; |
3510 | } | |
3511 | ||
8dc85d54 PZ |
3512 | err = -EINVAL; |
3513 | ctxn = pmu->task_ctx_nr; | |
3514 | if (ctxn < 0) | |
3515 | goto errout; | |
3516 | ||
4af57ef2 YZ |
3517 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3518 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3519 | if (!task_ctx_data) { | |
3520 | err = -ENOMEM; | |
3521 | goto errout; | |
3522 | } | |
3523 | } | |
3524 | ||
9ed6060d | 3525 | retry: |
8dc85d54 | 3526 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3527 | if (ctx) { |
211de6eb | 3528 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3529 | ++ctx->pin_count; |
4af57ef2 YZ |
3530 | |
3531 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3532 | ctx->task_ctx_data = task_ctx_data; | |
3533 | task_ctx_data = NULL; | |
3534 | } | |
e625cce1 | 3535 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3536 | |
3537 | if (clone_ctx) | |
3538 | put_ctx(clone_ctx); | |
9137fb28 | 3539 | } else { |
eb184479 | 3540 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3541 | err = -ENOMEM; |
3542 | if (!ctx) | |
3543 | goto errout; | |
eb184479 | 3544 | |
4af57ef2 YZ |
3545 | if (task_ctx_data) { |
3546 | ctx->task_ctx_data = task_ctx_data; | |
3547 | task_ctx_data = NULL; | |
3548 | } | |
3549 | ||
dbe08d82 ON |
3550 | err = 0; |
3551 | mutex_lock(&task->perf_event_mutex); | |
3552 | /* | |
3553 | * If it has already passed perf_event_exit_task(). | |
3554 | * we must see PF_EXITING, it takes this mutex too. | |
3555 | */ | |
3556 | if (task->flags & PF_EXITING) | |
3557 | err = -ESRCH; | |
3558 | else if (task->perf_event_ctxp[ctxn]) | |
3559 | err = -EAGAIN; | |
fe4b04fa | 3560 | else { |
9137fb28 | 3561 | get_ctx(ctx); |
fe4b04fa | 3562 | ++ctx->pin_count; |
dbe08d82 | 3563 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3564 | } |
dbe08d82 ON |
3565 | mutex_unlock(&task->perf_event_mutex); |
3566 | ||
3567 | if (unlikely(err)) { | |
9137fb28 | 3568 | put_ctx(ctx); |
dbe08d82 ON |
3569 | |
3570 | if (err == -EAGAIN) | |
3571 | goto retry; | |
3572 | goto errout; | |
a63eaf34 PM |
3573 | } |
3574 | } | |
3575 | ||
4af57ef2 | 3576 | kfree(task_ctx_data); |
0793a61d | 3577 | return ctx; |
c93f7669 | 3578 | |
9ed6060d | 3579 | errout: |
4af57ef2 | 3580 | kfree(task_ctx_data); |
c93f7669 | 3581 | return ERR_PTR(err); |
0793a61d TG |
3582 | } |
3583 | ||
6fb2915d | 3584 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3585 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3586 | |
cdd6c482 | 3587 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3588 | { |
cdd6c482 | 3589 | struct perf_event *event; |
592903cd | 3590 | |
cdd6c482 IM |
3591 | event = container_of(head, struct perf_event, rcu_head); |
3592 | if (event->ns) | |
3593 | put_pid_ns(event->ns); | |
6fb2915d | 3594 | perf_event_free_filter(event); |
cdd6c482 | 3595 | kfree(event); |
592903cd PZ |
3596 | } |
3597 | ||
b69cf536 PZ |
3598 | static void ring_buffer_attach(struct perf_event *event, |
3599 | struct ring_buffer *rb); | |
925d519a | 3600 | |
4beb31f3 | 3601 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3602 | { |
4beb31f3 FW |
3603 | if (event->parent) |
3604 | return; | |
3605 | ||
4beb31f3 FW |
3606 | if (is_cgroup_event(event)) |
3607 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3608 | } | |
925d519a | 3609 | |
555e0c1e FW |
3610 | #ifdef CONFIG_NO_HZ_FULL |
3611 | static DEFINE_SPINLOCK(nr_freq_lock); | |
3612 | #endif | |
3613 | ||
3614 | static void unaccount_freq_event_nohz(void) | |
3615 | { | |
3616 | #ifdef CONFIG_NO_HZ_FULL | |
3617 | spin_lock(&nr_freq_lock); | |
3618 | if (atomic_dec_and_test(&nr_freq_events)) | |
3619 | tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS); | |
3620 | spin_unlock(&nr_freq_lock); | |
3621 | #endif | |
3622 | } | |
3623 | ||
3624 | static void unaccount_freq_event(void) | |
3625 | { | |
3626 | if (tick_nohz_full_enabled()) | |
3627 | unaccount_freq_event_nohz(); | |
3628 | else | |
3629 | atomic_dec(&nr_freq_events); | |
3630 | } | |
3631 | ||
4beb31f3 FW |
3632 | static void unaccount_event(struct perf_event *event) |
3633 | { | |
25432ae9 PZ |
3634 | bool dec = false; |
3635 | ||
4beb31f3 FW |
3636 | if (event->parent) |
3637 | return; | |
3638 | ||
3639 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3640 | dec = true; |
4beb31f3 FW |
3641 | if (event->attr.mmap || event->attr.mmap_data) |
3642 | atomic_dec(&nr_mmap_events); | |
3643 | if (event->attr.comm) | |
3644 | atomic_dec(&nr_comm_events); | |
3645 | if (event->attr.task) | |
3646 | atomic_dec(&nr_task_events); | |
948b26b6 | 3647 | if (event->attr.freq) |
555e0c1e | 3648 | unaccount_freq_event(); |
45ac1403 | 3649 | if (event->attr.context_switch) { |
25432ae9 | 3650 | dec = true; |
45ac1403 AH |
3651 | atomic_dec(&nr_switch_events); |
3652 | } | |
4beb31f3 | 3653 | if (is_cgroup_event(event)) |
25432ae9 | 3654 | dec = true; |
4beb31f3 | 3655 | if (has_branch_stack(event)) |
25432ae9 PZ |
3656 | dec = true; |
3657 | ||
9107c89e PZ |
3658 | if (dec) { |
3659 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
3660 | schedule_delayed_work(&perf_sched_work, HZ); | |
3661 | } | |
4beb31f3 FW |
3662 | |
3663 | unaccount_event_cpu(event, event->cpu); | |
3664 | } | |
925d519a | 3665 | |
9107c89e PZ |
3666 | static void perf_sched_delayed(struct work_struct *work) |
3667 | { | |
3668 | mutex_lock(&perf_sched_mutex); | |
3669 | if (atomic_dec_and_test(&perf_sched_count)) | |
3670 | static_branch_disable(&perf_sched_events); | |
3671 | mutex_unlock(&perf_sched_mutex); | |
3672 | } | |
3673 | ||
bed5b25a AS |
3674 | /* |
3675 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3676 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3677 | * at a time, so we disallow creating events that might conflict, namely: | |
3678 | * | |
3679 | * 1) cpu-wide events in the presence of per-task events, | |
3680 | * 2) per-task events in the presence of cpu-wide events, | |
3681 | * 3) two matching events on the same context. | |
3682 | * | |
3683 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3684 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3685 | */ |
3686 | static int exclusive_event_init(struct perf_event *event) | |
3687 | { | |
3688 | struct pmu *pmu = event->pmu; | |
3689 | ||
3690 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3691 | return 0; | |
3692 | ||
3693 | /* | |
3694 | * Prevent co-existence of per-task and cpu-wide events on the | |
3695 | * same exclusive pmu. | |
3696 | * | |
3697 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3698 | * events on this "exclusive" pmu, positive means there are | |
3699 | * per-task events. | |
3700 | * | |
3701 | * Since this is called in perf_event_alloc() path, event::ctx | |
3702 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3703 | * to mean "per-task event", because unlike other attach states it | |
3704 | * never gets cleared. | |
3705 | */ | |
3706 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3707 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3708 | return -EBUSY; | |
3709 | } else { | |
3710 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3711 | return -EBUSY; | |
3712 | } | |
3713 | ||
3714 | return 0; | |
3715 | } | |
3716 | ||
3717 | static void exclusive_event_destroy(struct perf_event *event) | |
3718 | { | |
3719 | struct pmu *pmu = event->pmu; | |
3720 | ||
3721 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3722 | return; | |
3723 | ||
3724 | /* see comment in exclusive_event_init() */ | |
3725 | if (event->attach_state & PERF_ATTACH_TASK) | |
3726 | atomic_dec(&pmu->exclusive_cnt); | |
3727 | else | |
3728 | atomic_inc(&pmu->exclusive_cnt); | |
3729 | } | |
3730 | ||
3731 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3732 | { | |
3733 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3734 | (e1->cpu == e2->cpu || | |
3735 | e1->cpu == -1 || | |
3736 | e2->cpu == -1)) | |
3737 | return true; | |
3738 | return false; | |
3739 | } | |
3740 | ||
3741 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3742 | static bool exclusive_event_installable(struct perf_event *event, | |
3743 | struct perf_event_context *ctx) | |
3744 | { | |
3745 | struct perf_event *iter_event; | |
3746 | struct pmu *pmu = event->pmu; | |
3747 | ||
3748 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3749 | return true; | |
3750 | ||
3751 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3752 | if (exclusive_event_match(iter_event, event)) | |
3753 | return false; | |
3754 | } | |
3755 | ||
3756 | return true; | |
3757 | } | |
3758 | ||
683ede43 | 3759 | static void _free_event(struct perf_event *event) |
f1600952 | 3760 | { |
e360adbe | 3761 | irq_work_sync(&event->pending); |
925d519a | 3762 | |
4beb31f3 | 3763 | unaccount_event(event); |
9ee318a7 | 3764 | |
76369139 | 3765 | if (event->rb) { |
9bb5d40c PZ |
3766 | /* |
3767 | * Can happen when we close an event with re-directed output. | |
3768 | * | |
3769 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3770 | * over us; possibly making our ring_buffer_put() the last. | |
3771 | */ | |
3772 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3773 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3774 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3775 | } |
3776 | ||
e5d1367f SE |
3777 | if (is_cgroup_event(event)) |
3778 | perf_detach_cgroup(event); | |
3779 | ||
a0733e69 PZ |
3780 | if (!event->parent) { |
3781 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3782 | put_callchain_buffers(); | |
3783 | } | |
3784 | ||
3785 | perf_event_free_bpf_prog(event); | |
3786 | ||
3787 | if (event->destroy) | |
3788 | event->destroy(event); | |
3789 | ||
3790 | if (event->ctx) | |
3791 | put_ctx(event->ctx); | |
3792 | ||
3793 | if (event->pmu) { | |
3794 | exclusive_event_destroy(event); | |
3795 | module_put(event->pmu->module); | |
3796 | } | |
3797 | ||
3798 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3799 | } |
3800 | ||
683ede43 PZ |
3801 | /* |
3802 | * Used to free events which have a known refcount of 1, such as in error paths | |
3803 | * where the event isn't exposed yet and inherited events. | |
3804 | */ | |
3805 | static void free_event(struct perf_event *event) | |
0793a61d | 3806 | { |
683ede43 PZ |
3807 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3808 | "unexpected event refcount: %ld; ptr=%p\n", | |
3809 | atomic_long_read(&event->refcount), event)) { | |
3810 | /* leak to avoid use-after-free */ | |
3811 | return; | |
3812 | } | |
0793a61d | 3813 | |
683ede43 | 3814 | _free_event(event); |
0793a61d TG |
3815 | } |
3816 | ||
a66a3052 | 3817 | /* |
f8697762 | 3818 | * Remove user event from the owner task. |
a66a3052 | 3819 | */ |
f8697762 | 3820 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3821 | { |
8882135b | 3822 | struct task_struct *owner; |
fb0459d7 | 3823 | |
8882135b | 3824 | rcu_read_lock(); |
8882135b | 3825 | /* |
f47c02c0 PZ |
3826 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3827 | * observe !owner it means the list deletion is complete and we can | |
3828 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3829 | * owner->perf_event_mutex. |
3830 | */ | |
f47c02c0 | 3831 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3832 | if (owner) { |
3833 | /* | |
3834 | * Since delayed_put_task_struct() also drops the last | |
3835 | * task reference we can safely take a new reference | |
3836 | * while holding the rcu_read_lock(). | |
3837 | */ | |
3838 | get_task_struct(owner); | |
3839 | } | |
3840 | rcu_read_unlock(); | |
3841 | ||
3842 | if (owner) { | |
f63a8daa PZ |
3843 | /* |
3844 | * If we're here through perf_event_exit_task() we're already | |
3845 | * holding ctx->mutex which would be an inversion wrt. the | |
3846 | * normal lock order. | |
3847 | * | |
3848 | * However we can safely take this lock because its the child | |
3849 | * ctx->mutex. | |
3850 | */ | |
3851 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3852 | ||
8882135b PZ |
3853 | /* |
3854 | * We have to re-check the event->owner field, if it is cleared | |
3855 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3856 | * ensured they're done, and we can proceed with freeing the | |
3857 | * event. | |
3858 | */ | |
f47c02c0 | 3859 | if (event->owner) { |
8882135b | 3860 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3861 | smp_store_release(&event->owner, NULL); |
3862 | } | |
8882135b PZ |
3863 | mutex_unlock(&owner->perf_event_mutex); |
3864 | put_task_struct(owner); | |
3865 | } | |
f8697762 JO |
3866 | } |
3867 | ||
f8697762 JO |
3868 | static void put_event(struct perf_event *event) |
3869 | { | |
f8697762 JO |
3870 | if (!atomic_long_dec_and_test(&event->refcount)) |
3871 | return; | |
3872 | ||
c6e5b732 PZ |
3873 | _free_event(event); |
3874 | } | |
3875 | ||
3876 | /* | |
3877 | * Kill an event dead; while event:refcount will preserve the event | |
3878 | * object, it will not preserve its functionality. Once the last 'user' | |
3879 | * gives up the object, we'll destroy the thing. | |
3880 | */ | |
3881 | int perf_event_release_kernel(struct perf_event *event) | |
3882 | { | |
a4f4bb6d | 3883 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
3884 | struct perf_event *child, *tmp; |
3885 | ||
a4f4bb6d PZ |
3886 | /* |
3887 | * If we got here through err_file: fput(event_file); we will not have | |
3888 | * attached to a context yet. | |
3889 | */ | |
3890 | if (!ctx) { | |
3891 | WARN_ON_ONCE(event->attach_state & | |
3892 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
3893 | goto no_ctx; | |
3894 | } | |
3895 | ||
f8697762 JO |
3896 | if (!is_kernel_event(event)) |
3897 | perf_remove_from_owner(event); | |
8882135b | 3898 | |
5fa7c8ec | 3899 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3900 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 3901 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 3902 | |
a69b0ca4 | 3903 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 3904 | /* |
a69b0ca4 PZ |
3905 | * Mark this even as STATE_DEAD, there is no external reference to it |
3906 | * anymore. | |
683ede43 | 3907 | * |
a69b0ca4 PZ |
3908 | * Anybody acquiring event->child_mutex after the below loop _must_ |
3909 | * also see this, most importantly inherit_event() which will avoid | |
3910 | * placing more children on the list. | |
683ede43 | 3911 | * |
c6e5b732 PZ |
3912 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3913 | * child events. | |
683ede43 | 3914 | */ |
a69b0ca4 PZ |
3915 | event->state = PERF_EVENT_STATE_DEAD; |
3916 | raw_spin_unlock_irq(&ctx->lock); | |
3917 | ||
3918 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 3919 | |
c6e5b732 PZ |
3920 | again: |
3921 | mutex_lock(&event->child_mutex); | |
3922 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3923 | |
c6e5b732 PZ |
3924 | /* |
3925 | * Cannot change, child events are not migrated, see the | |
3926 | * comment with perf_event_ctx_lock_nested(). | |
3927 | */ | |
3928 | ctx = lockless_dereference(child->ctx); | |
3929 | /* | |
3930 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3931 | * through hoops. We start by grabbing a reference on the ctx. | |
3932 | * | |
3933 | * Since the event cannot get freed while we hold the | |
3934 | * child_mutex, the context must also exist and have a !0 | |
3935 | * reference count. | |
3936 | */ | |
3937 | get_ctx(ctx); | |
3938 | ||
3939 | /* | |
3940 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3941 | * acquire ctx::mutex without fear of it going away. Then we | |
3942 | * can re-acquire child_mutex. | |
3943 | */ | |
3944 | mutex_unlock(&event->child_mutex); | |
3945 | mutex_lock(&ctx->mutex); | |
3946 | mutex_lock(&event->child_mutex); | |
3947 | ||
3948 | /* | |
3949 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3950 | * state, if child is still the first entry, it didn't get freed | |
3951 | * and we can continue doing so. | |
3952 | */ | |
3953 | tmp = list_first_entry_or_null(&event->child_list, | |
3954 | struct perf_event, child_list); | |
3955 | if (tmp == child) { | |
3956 | perf_remove_from_context(child, DETACH_GROUP); | |
3957 | list_del(&child->child_list); | |
3958 | free_event(child); | |
3959 | /* | |
3960 | * This matches the refcount bump in inherit_event(); | |
3961 | * this can't be the last reference. | |
3962 | */ | |
3963 | put_event(event); | |
3964 | } | |
3965 | ||
3966 | mutex_unlock(&event->child_mutex); | |
3967 | mutex_unlock(&ctx->mutex); | |
3968 | put_ctx(ctx); | |
3969 | goto again; | |
3970 | } | |
3971 | mutex_unlock(&event->child_mutex); | |
3972 | ||
a4f4bb6d PZ |
3973 | no_ctx: |
3974 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
3975 | return 0; |
3976 | } | |
3977 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3978 | ||
8b10c5e2 PZ |
3979 | /* |
3980 | * Called when the last reference to the file is gone. | |
3981 | */ | |
a6fa941d AV |
3982 | static int perf_release(struct inode *inode, struct file *file) |
3983 | { | |
c6e5b732 | 3984 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3985 | return 0; |
fb0459d7 | 3986 | } |
fb0459d7 | 3987 | |
59ed446f | 3988 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3989 | { |
cdd6c482 | 3990 | struct perf_event *child; |
e53c0994 PZ |
3991 | u64 total = 0; |
3992 | ||
59ed446f PZ |
3993 | *enabled = 0; |
3994 | *running = 0; | |
3995 | ||
6f10581a | 3996 | mutex_lock(&event->child_mutex); |
01add3ea | 3997 | |
7d88962e | 3998 | (void)perf_event_read(event, false); |
01add3ea SB |
3999 | total += perf_event_count(event); |
4000 | ||
59ed446f PZ |
4001 | *enabled += event->total_time_enabled + |
4002 | atomic64_read(&event->child_total_time_enabled); | |
4003 | *running += event->total_time_running + | |
4004 | atomic64_read(&event->child_total_time_running); | |
4005 | ||
4006 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 4007 | (void)perf_event_read(child, false); |
01add3ea | 4008 | total += perf_event_count(child); |
59ed446f PZ |
4009 | *enabled += child->total_time_enabled; |
4010 | *running += child->total_time_running; | |
4011 | } | |
6f10581a | 4012 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
4013 | |
4014 | return total; | |
4015 | } | |
fb0459d7 | 4016 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 4017 | |
7d88962e | 4018 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 4019 | u64 read_format, u64 *values) |
3dab77fb | 4020 | { |
fa8c2693 PZ |
4021 | struct perf_event *sub; |
4022 | int n = 1; /* skip @nr */ | |
7d88962e | 4023 | int ret; |
f63a8daa | 4024 | |
7d88962e SB |
4025 | ret = perf_event_read(leader, true); |
4026 | if (ret) | |
4027 | return ret; | |
abf4868b | 4028 | |
fa8c2693 PZ |
4029 | /* |
4030 | * Since we co-schedule groups, {enabled,running} times of siblings | |
4031 | * will be identical to those of the leader, so we only publish one | |
4032 | * set. | |
4033 | */ | |
4034 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
4035 | values[n++] += leader->total_time_enabled + | |
4036 | atomic64_read(&leader->child_total_time_enabled); | |
4037 | } | |
3dab77fb | 4038 | |
fa8c2693 PZ |
4039 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
4040 | values[n++] += leader->total_time_running + | |
4041 | atomic64_read(&leader->child_total_time_running); | |
4042 | } | |
4043 | ||
4044 | /* | |
4045 | * Write {count,id} tuples for every sibling. | |
4046 | */ | |
4047 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
4048 | if (read_format & PERF_FORMAT_ID) |
4049 | values[n++] = primary_event_id(leader); | |
3dab77fb | 4050 | |
fa8c2693 PZ |
4051 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
4052 | values[n++] += perf_event_count(sub); | |
4053 | if (read_format & PERF_FORMAT_ID) | |
4054 | values[n++] = primary_event_id(sub); | |
4055 | } | |
7d88962e SB |
4056 | |
4057 | return 0; | |
fa8c2693 | 4058 | } |
3dab77fb | 4059 | |
fa8c2693 PZ |
4060 | static int perf_read_group(struct perf_event *event, |
4061 | u64 read_format, char __user *buf) | |
4062 | { | |
4063 | struct perf_event *leader = event->group_leader, *child; | |
4064 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 4065 | int ret; |
fa8c2693 | 4066 | u64 *values; |
3dab77fb | 4067 | |
fa8c2693 | 4068 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 4069 | |
fa8c2693 PZ |
4070 | values = kzalloc(event->read_size, GFP_KERNEL); |
4071 | if (!values) | |
4072 | return -ENOMEM; | |
3dab77fb | 4073 | |
fa8c2693 PZ |
4074 | values[0] = 1 + leader->nr_siblings; |
4075 | ||
4076 | /* | |
4077 | * By locking the child_mutex of the leader we effectively | |
4078 | * lock the child list of all siblings.. XXX explain how. | |
4079 | */ | |
4080 | mutex_lock(&leader->child_mutex); | |
abf4868b | 4081 | |
7d88962e SB |
4082 | ret = __perf_read_group_add(leader, read_format, values); |
4083 | if (ret) | |
4084 | goto unlock; | |
4085 | ||
4086 | list_for_each_entry(child, &leader->child_list, child_list) { | |
4087 | ret = __perf_read_group_add(child, read_format, values); | |
4088 | if (ret) | |
4089 | goto unlock; | |
4090 | } | |
abf4868b | 4091 | |
fa8c2693 | 4092 | mutex_unlock(&leader->child_mutex); |
abf4868b | 4093 | |
7d88962e | 4094 | ret = event->read_size; |
fa8c2693 PZ |
4095 | if (copy_to_user(buf, values, event->read_size)) |
4096 | ret = -EFAULT; | |
7d88962e | 4097 | goto out; |
fa8c2693 | 4098 | |
7d88962e SB |
4099 | unlock: |
4100 | mutex_unlock(&leader->child_mutex); | |
4101 | out: | |
fa8c2693 | 4102 | kfree(values); |
abf4868b | 4103 | return ret; |
3dab77fb PZ |
4104 | } |
4105 | ||
b15f495b | 4106 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4107 | u64 read_format, char __user *buf) |
4108 | { | |
59ed446f | 4109 | u64 enabled, running; |
3dab77fb PZ |
4110 | u64 values[4]; |
4111 | int n = 0; | |
4112 | ||
59ed446f PZ |
4113 | values[n++] = perf_event_read_value(event, &enabled, &running); |
4114 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4115 | values[n++] = enabled; | |
4116 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4117 | values[n++] = running; | |
3dab77fb | 4118 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4119 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4120 | |
4121 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4122 | return -EFAULT; | |
4123 | ||
4124 | return n * sizeof(u64); | |
4125 | } | |
4126 | ||
dc633982 JO |
4127 | static bool is_event_hup(struct perf_event *event) |
4128 | { | |
4129 | bool no_children; | |
4130 | ||
a69b0ca4 | 4131 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4132 | return false; |
4133 | ||
4134 | mutex_lock(&event->child_mutex); | |
4135 | no_children = list_empty(&event->child_list); | |
4136 | mutex_unlock(&event->child_mutex); | |
4137 | return no_children; | |
4138 | } | |
4139 | ||
0793a61d | 4140 | /* |
cdd6c482 | 4141 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4142 | */ |
4143 | static ssize_t | |
b15f495b | 4144 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4145 | { |
cdd6c482 | 4146 | u64 read_format = event->attr.read_format; |
3dab77fb | 4147 | int ret; |
0793a61d | 4148 | |
3b6f9e5c | 4149 | /* |
cdd6c482 | 4150 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4151 | * error state (i.e. because it was pinned but it couldn't be |
4152 | * scheduled on to the CPU at some point). | |
4153 | */ | |
cdd6c482 | 4154 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4155 | return 0; |
4156 | ||
c320c7b7 | 4157 | if (count < event->read_size) |
3dab77fb PZ |
4158 | return -ENOSPC; |
4159 | ||
cdd6c482 | 4160 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4161 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4162 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4163 | else |
b15f495b | 4164 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4165 | |
3dab77fb | 4166 | return ret; |
0793a61d TG |
4167 | } |
4168 | ||
0793a61d TG |
4169 | static ssize_t |
4170 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4171 | { | |
cdd6c482 | 4172 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4173 | struct perf_event_context *ctx; |
4174 | int ret; | |
0793a61d | 4175 | |
f63a8daa | 4176 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4177 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4178 | perf_event_ctx_unlock(event, ctx); |
4179 | ||
4180 | return ret; | |
0793a61d TG |
4181 | } |
4182 | ||
4183 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4184 | { | |
cdd6c482 | 4185 | struct perf_event *event = file->private_data; |
76369139 | 4186 | struct ring_buffer *rb; |
61b67684 | 4187 | unsigned int events = POLLHUP; |
c7138f37 | 4188 | |
e708d7ad | 4189 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4190 | |
dc633982 | 4191 | if (is_event_hup(event)) |
179033b3 | 4192 | return events; |
c7138f37 | 4193 | |
10c6db11 | 4194 | /* |
9bb5d40c PZ |
4195 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4196 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4197 | */ |
4198 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4199 | rb = event->rb; |
4200 | if (rb) | |
76369139 | 4201 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4202 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4203 | return events; |
4204 | } | |
4205 | ||
f63a8daa | 4206 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4207 | { |
7d88962e | 4208 | (void)perf_event_read(event, false); |
e7850595 | 4209 | local64_set(&event->count, 0); |
cdd6c482 | 4210 | perf_event_update_userpage(event); |
3df5edad PZ |
4211 | } |
4212 | ||
c93f7669 | 4213 | /* |
cdd6c482 IM |
4214 | * Holding the top-level event's child_mutex means that any |
4215 | * descendant process that has inherited this event will block | |
8ba289b8 | 4216 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4217 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4218 | */ |
cdd6c482 IM |
4219 | static void perf_event_for_each_child(struct perf_event *event, |
4220 | void (*func)(struct perf_event *)) | |
3df5edad | 4221 | { |
cdd6c482 | 4222 | struct perf_event *child; |
3df5edad | 4223 | |
cdd6c482 | 4224 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4225 | |
cdd6c482 IM |
4226 | mutex_lock(&event->child_mutex); |
4227 | func(event); | |
4228 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4229 | func(child); |
cdd6c482 | 4230 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4231 | } |
4232 | ||
cdd6c482 IM |
4233 | static void perf_event_for_each(struct perf_event *event, |
4234 | void (*func)(struct perf_event *)) | |
3df5edad | 4235 | { |
cdd6c482 IM |
4236 | struct perf_event_context *ctx = event->ctx; |
4237 | struct perf_event *sibling; | |
3df5edad | 4238 | |
f63a8daa PZ |
4239 | lockdep_assert_held(&ctx->mutex); |
4240 | ||
cdd6c482 | 4241 | event = event->group_leader; |
75f937f2 | 4242 | |
cdd6c482 | 4243 | perf_event_for_each_child(event, func); |
cdd6c482 | 4244 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4245 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4246 | } |
4247 | ||
fae3fde6 PZ |
4248 | static void __perf_event_period(struct perf_event *event, |
4249 | struct perf_cpu_context *cpuctx, | |
4250 | struct perf_event_context *ctx, | |
4251 | void *info) | |
c7999c6f | 4252 | { |
fae3fde6 | 4253 | u64 value = *((u64 *)info); |
c7999c6f | 4254 | bool active; |
08247e31 | 4255 | |
cdd6c482 | 4256 | if (event->attr.freq) { |
cdd6c482 | 4257 | event->attr.sample_freq = value; |
08247e31 | 4258 | } else { |
cdd6c482 IM |
4259 | event->attr.sample_period = value; |
4260 | event->hw.sample_period = value; | |
08247e31 | 4261 | } |
bad7192b PZ |
4262 | |
4263 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4264 | if (active) { | |
4265 | perf_pmu_disable(ctx->pmu); | |
1e02cd40 PZ |
4266 | /* |
4267 | * We could be throttled; unthrottle now to avoid the tick | |
4268 | * trying to unthrottle while we already re-started the event. | |
4269 | */ | |
4270 | if (event->hw.interrupts == MAX_INTERRUPTS) { | |
4271 | event->hw.interrupts = 0; | |
4272 | perf_log_throttle(event, 1); | |
4273 | } | |
bad7192b PZ |
4274 | event->pmu->stop(event, PERF_EF_UPDATE); |
4275 | } | |
4276 | ||
4277 | local64_set(&event->hw.period_left, 0); | |
4278 | ||
4279 | if (active) { | |
4280 | event->pmu->start(event, PERF_EF_RELOAD); | |
4281 | perf_pmu_enable(ctx->pmu); | |
4282 | } | |
c7999c6f PZ |
4283 | } |
4284 | ||
4285 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4286 | { | |
c7999c6f PZ |
4287 | u64 value; |
4288 | ||
4289 | if (!is_sampling_event(event)) | |
4290 | return -EINVAL; | |
4291 | ||
4292 | if (copy_from_user(&value, arg, sizeof(value))) | |
4293 | return -EFAULT; | |
4294 | ||
4295 | if (!value) | |
4296 | return -EINVAL; | |
4297 | ||
4298 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4299 | return -EINVAL; | |
4300 | ||
fae3fde6 | 4301 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4302 | |
c7999c6f | 4303 | return 0; |
08247e31 PZ |
4304 | } |
4305 | ||
ac9721f3 PZ |
4306 | static const struct file_operations perf_fops; |
4307 | ||
2903ff01 | 4308 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4309 | { |
2903ff01 AV |
4310 | struct fd f = fdget(fd); |
4311 | if (!f.file) | |
4312 | return -EBADF; | |
ac9721f3 | 4313 | |
2903ff01 AV |
4314 | if (f.file->f_op != &perf_fops) { |
4315 | fdput(f); | |
4316 | return -EBADF; | |
ac9721f3 | 4317 | } |
2903ff01 AV |
4318 | *p = f; |
4319 | return 0; | |
ac9721f3 PZ |
4320 | } |
4321 | ||
4322 | static int perf_event_set_output(struct perf_event *event, | |
4323 | struct perf_event *output_event); | |
6fb2915d | 4324 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4325 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4326 | |
f63a8daa | 4327 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4328 | { |
cdd6c482 | 4329 | void (*func)(struct perf_event *); |
3df5edad | 4330 | u32 flags = arg; |
d859e29f PM |
4331 | |
4332 | switch (cmd) { | |
cdd6c482 | 4333 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4334 | func = _perf_event_enable; |
d859e29f | 4335 | break; |
cdd6c482 | 4336 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4337 | func = _perf_event_disable; |
79f14641 | 4338 | break; |
cdd6c482 | 4339 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4340 | func = _perf_event_reset; |
6de6a7b9 | 4341 | break; |
3df5edad | 4342 | |
cdd6c482 | 4343 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4344 | return _perf_event_refresh(event, arg); |
08247e31 | 4345 | |
cdd6c482 IM |
4346 | case PERF_EVENT_IOC_PERIOD: |
4347 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4348 | |
cf4957f1 JO |
4349 | case PERF_EVENT_IOC_ID: |
4350 | { | |
4351 | u64 id = primary_event_id(event); | |
4352 | ||
4353 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4354 | return -EFAULT; | |
4355 | return 0; | |
4356 | } | |
4357 | ||
cdd6c482 | 4358 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4359 | { |
ac9721f3 | 4360 | int ret; |
ac9721f3 | 4361 | if (arg != -1) { |
2903ff01 AV |
4362 | struct perf_event *output_event; |
4363 | struct fd output; | |
4364 | ret = perf_fget_light(arg, &output); | |
4365 | if (ret) | |
4366 | return ret; | |
4367 | output_event = output.file->private_data; | |
4368 | ret = perf_event_set_output(event, output_event); | |
4369 | fdput(output); | |
4370 | } else { | |
4371 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4372 | } |
ac9721f3 PZ |
4373 | return ret; |
4374 | } | |
a4be7c27 | 4375 | |
6fb2915d LZ |
4376 | case PERF_EVENT_IOC_SET_FILTER: |
4377 | return perf_event_set_filter(event, (void __user *)arg); | |
4378 | ||
2541517c AS |
4379 | case PERF_EVENT_IOC_SET_BPF: |
4380 | return perf_event_set_bpf_prog(event, arg); | |
4381 | ||
d859e29f | 4382 | default: |
3df5edad | 4383 | return -ENOTTY; |
d859e29f | 4384 | } |
3df5edad PZ |
4385 | |
4386 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4387 | perf_event_for_each(event, func); |
3df5edad | 4388 | else |
cdd6c482 | 4389 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4390 | |
4391 | return 0; | |
d859e29f PM |
4392 | } |
4393 | ||
f63a8daa PZ |
4394 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4395 | { | |
4396 | struct perf_event *event = file->private_data; | |
4397 | struct perf_event_context *ctx; | |
4398 | long ret; | |
4399 | ||
4400 | ctx = perf_event_ctx_lock(event); | |
4401 | ret = _perf_ioctl(event, cmd, arg); | |
4402 | perf_event_ctx_unlock(event, ctx); | |
4403 | ||
4404 | return ret; | |
4405 | } | |
4406 | ||
b3f20785 PM |
4407 | #ifdef CONFIG_COMPAT |
4408 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4409 | unsigned long arg) | |
4410 | { | |
4411 | switch (_IOC_NR(cmd)) { | |
4412 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4413 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4414 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4415 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4416 | cmd &= ~IOCSIZE_MASK; | |
4417 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4418 | } | |
4419 | break; | |
4420 | } | |
4421 | return perf_ioctl(file, cmd, arg); | |
4422 | } | |
4423 | #else | |
4424 | # define perf_compat_ioctl NULL | |
4425 | #endif | |
4426 | ||
cdd6c482 | 4427 | int perf_event_task_enable(void) |
771d7cde | 4428 | { |
f63a8daa | 4429 | struct perf_event_context *ctx; |
cdd6c482 | 4430 | struct perf_event *event; |
771d7cde | 4431 | |
cdd6c482 | 4432 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4433 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4434 | ctx = perf_event_ctx_lock(event); | |
4435 | perf_event_for_each_child(event, _perf_event_enable); | |
4436 | perf_event_ctx_unlock(event, ctx); | |
4437 | } | |
cdd6c482 | 4438 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4439 | |
4440 | return 0; | |
4441 | } | |
4442 | ||
cdd6c482 | 4443 | int perf_event_task_disable(void) |
771d7cde | 4444 | { |
f63a8daa | 4445 | struct perf_event_context *ctx; |
cdd6c482 | 4446 | struct perf_event *event; |
771d7cde | 4447 | |
cdd6c482 | 4448 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4449 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4450 | ctx = perf_event_ctx_lock(event); | |
4451 | perf_event_for_each_child(event, _perf_event_disable); | |
4452 | perf_event_ctx_unlock(event, ctx); | |
4453 | } | |
cdd6c482 | 4454 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4455 | |
4456 | return 0; | |
4457 | } | |
4458 | ||
cdd6c482 | 4459 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4460 | { |
a4eaf7f1 PZ |
4461 | if (event->hw.state & PERF_HES_STOPPED) |
4462 | return 0; | |
4463 | ||
cdd6c482 | 4464 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4465 | return 0; |
4466 | ||
35edc2a5 | 4467 | return event->pmu->event_idx(event); |
194002b2 PZ |
4468 | } |
4469 | ||
c4794295 | 4470 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4471 | u64 *now, |
7f310a5d EM |
4472 | u64 *enabled, |
4473 | u64 *running) | |
c4794295 | 4474 | { |
e3f3541c | 4475 | u64 ctx_time; |
c4794295 | 4476 | |
e3f3541c PZ |
4477 | *now = perf_clock(); |
4478 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4479 | *enabled = ctx_time - event->tstamp_enabled; |
4480 | *running = ctx_time - event->tstamp_running; | |
4481 | } | |
4482 | ||
fa731587 PZ |
4483 | static void perf_event_init_userpage(struct perf_event *event) |
4484 | { | |
4485 | struct perf_event_mmap_page *userpg; | |
4486 | struct ring_buffer *rb; | |
4487 | ||
4488 | rcu_read_lock(); | |
4489 | rb = rcu_dereference(event->rb); | |
4490 | if (!rb) | |
4491 | goto unlock; | |
4492 | ||
4493 | userpg = rb->user_page; | |
4494 | ||
4495 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4496 | userpg->cap_bit0_is_deprecated = 1; | |
4497 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4498 | userpg->data_offset = PAGE_SIZE; |
4499 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4500 | |
4501 | unlock: | |
4502 | rcu_read_unlock(); | |
4503 | } | |
4504 | ||
c1317ec2 AL |
4505 | void __weak arch_perf_update_userpage( |
4506 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4507 | { |
4508 | } | |
4509 | ||
38ff667b PZ |
4510 | /* |
4511 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4512 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4513 | * code calls this from NMI context. | |
4514 | */ | |
cdd6c482 | 4515 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4516 | { |
cdd6c482 | 4517 | struct perf_event_mmap_page *userpg; |
76369139 | 4518 | struct ring_buffer *rb; |
e3f3541c | 4519 | u64 enabled, running, now; |
38ff667b PZ |
4520 | |
4521 | rcu_read_lock(); | |
5ec4c599 PZ |
4522 | rb = rcu_dereference(event->rb); |
4523 | if (!rb) | |
4524 | goto unlock; | |
4525 | ||
0d641208 EM |
4526 | /* |
4527 | * compute total_time_enabled, total_time_running | |
4528 | * based on snapshot values taken when the event | |
4529 | * was last scheduled in. | |
4530 | * | |
4531 | * we cannot simply called update_context_time() | |
4532 | * because of locking issue as we can be called in | |
4533 | * NMI context | |
4534 | */ | |
e3f3541c | 4535 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4536 | |
76369139 | 4537 | userpg = rb->user_page; |
7b732a75 PZ |
4538 | /* |
4539 | * Disable preemption so as to not let the corresponding user-space | |
4540 | * spin too long if we get preempted. | |
4541 | */ | |
4542 | preempt_disable(); | |
37d81828 | 4543 | ++userpg->lock; |
92f22a38 | 4544 | barrier(); |
cdd6c482 | 4545 | userpg->index = perf_event_index(event); |
b5e58793 | 4546 | userpg->offset = perf_event_count(event); |
365a4038 | 4547 | if (userpg->index) |
e7850595 | 4548 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4549 | |
0d641208 | 4550 | userpg->time_enabled = enabled + |
cdd6c482 | 4551 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4552 | |
0d641208 | 4553 | userpg->time_running = running + |
cdd6c482 | 4554 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4555 | |
c1317ec2 | 4556 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4557 | |
92f22a38 | 4558 | barrier(); |
37d81828 | 4559 | ++userpg->lock; |
7b732a75 | 4560 | preempt_enable(); |
38ff667b | 4561 | unlock: |
7b732a75 | 4562 | rcu_read_unlock(); |
37d81828 PM |
4563 | } |
4564 | ||
906010b2 PZ |
4565 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4566 | { | |
4567 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4568 | struct ring_buffer *rb; |
906010b2 PZ |
4569 | int ret = VM_FAULT_SIGBUS; |
4570 | ||
4571 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4572 | if (vmf->pgoff == 0) | |
4573 | ret = 0; | |
4574 | return ret; | |
4575 | } | |
4576 | ||
4577 | rcu_read_lock(); | |
76369139 FW |
4578 | rb = rcu_dereference(event->rb); |
4579 | if (!rb) | |
906010b2 PZ |
4580 | goto unlock; |
4581 | ||
4582 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4583 | goto unlock; | |
4584 | ||
76369139 | 4585 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4586 | if (!vmf->page) |
4587 | goto unlock; | |
4588 | ||
4589 | get_page(vmf->page); | |
4590 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4591 | vmf->page->index = vmf->pgoff; | |
4592 | ||
4593 | ret = 0; | |
4594 | unlock: | |
4595 | rcu_read_unlock(); | |
4596 | ||
4597 | return ret; | |
4598 | } | |
4599 | ||
10c6db11 PZ |
4600 | static void ring_buffer_attach(struct perf_event *event, |
4601 | struct ring_buffer *rb) | |
4602 | { | |
b69cf536 | 4603 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4604 | unsigned long flags; |
4605 | ||
b69cf536 PZ |
4606 | if (event->rb) { |
4607 | /* | |
4608 | * Should be impossible, we set this when removing | |
4609 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4610 | */ | |
4611 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4612 | |
b69cf536 | 4613 | old_rb = event->rb; |
b69cf536 PZ |
4614 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4615 | list_del_rcu(&event->rb_entry); | |
4616 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4617 | |
2f993cf0 ON |
4618 | event->rcu_batches = get_state_synchronize_rcu(); |
4619 | event->rcu_pending = 1; | |
b69cf536 | 4620 | } |
10c6db11 | 4621 | |
b69cf536 | 4622 | if (rb) { |
2f993cf0 ON |
4623 | if (event->rcu_pending) { |
4624 | cond_synchronize_rcu(event->rcu_batches); | |
4625 | event->rcu_pending = 0; | |
4626 | } | |
4627 | ||
b69cf536 PZ |
4628 | spin_lock_irqsave(&rb->event_lock, flags); |
4629 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4630 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4631 | } | |
4632 | ||
4633 | rcu_assign_pointer(event->rb, rb); | |
4634 | ||
4635 | if (old_rb) { | |
4636 | ring_buffer_put(old_rb); | |
4637 | /* | |
4638 | * Since we detached before setting the new rb, so that we | |
4639 | * could attach the new rb, we could have missed a wakeup. | |
4640 | * Provide it now. | |
4641 | */ | |
4642 | wake_up_all(&event->waitq); | |
4643 | } | |
10c6db11 PZ |
4644 | } |
4645 | ||
4646 | static void ring_buffer_wakeup(struct perf_event *event) | |
4647 | { | |
4648 | struct ring_buffer *rb; | |
4649 | ||
4650 | rcu_read_lock(); | |
4651 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4652 | if (rb) { |
4653 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4654 | wake_up_all(&event->waitq); | |
4655 | } | |
10c6db11 PZ |
4656 | rcu_read_unlock(); |
4657 | } | |
4658 | ||
fdc26706 | 4659 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4660 | { |
76369139 | 4661 | struct ring_buffer *rb; |
7b732a75 | 4662 | |
ac9721f3 | 4663 | rcu_read_lock(); |
76369139 FW |
4664 | rb = rcu_dereference(event->rb); |
4665 | if (rb) { | |
4666 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4667 | rb = NULL; | |
ac9721f3 PZ |
4668 | } |
4669 | rcu_read_unlock(); | |
4670 | ||
76369139 | 4671 | return rb; |
ac9721f3 PZ |
4672 | } |
4673 | ||
fdc26706 | 4674 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4675 | { |
76369139 | 4676 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4677 | return; |
7b732a75 | 4678 | |
9bb5d40c | 4679 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4680 | |
76369139 | 4681 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4682 | } |
4683 | ||
4684 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4685 | { | |
cdd6c482 | 4686 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4687 | |
cdd6c482 | 4688 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4689 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4690 | |
45bfb2e5 PZ |
4691 | if (vma->vm_pgoff) |
4692 | atomic_inc(&event->rb->aux_mmap_count); | |
4693 | ||
1e0fb9ec AL |
4694 | if (event->pmu->event_mapped) |
4695 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4696 | } |
4697 | ||
95ff4ca2 AS |
4698 | static void perf_pmu_output_stop(struct perf_event *event); |
4699 | ||
9bb5d40c PZ |
4700 | /* |
4701 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4702 | * event, or through other events by use of perf_event_set_output(). | |
4703 | * | |
4704 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4705 | * the buffer here, where we still have a VM context. This means we need | |
4706 | * to detach all events redirecting to us. | |
4707 | */ | |
7b732a75 PZ |
4708 | static void perf_mmap_close(struct vm_area_struct *vma) |
4709 | { | |
cdd6c482 | 4710 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4711 | |
b69cf536 | 4712 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4713 | struct user_struct *mmap_user = rb->mmap_user; |
4714 | int mmap_locked = rb->mmap_locked; | |
4715 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4716 | |
1e0fb9ec AL |
4717 | if (event->pmu->event_unmapped) |
4718 | event->pmu->event_unmapped(event); | |
4719 | ||
45bfb2e5 PZ |
4720 | /* |
4721 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4722 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4723 | * serialize with perf_mmap here. | |
4724 | */ | |
4725 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4726 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
95ff4ca2 AS |
4727 | /* |
4728 | * Stop all AUX events that are writing to this buffer, | |
4729 | * so that we can free its AUX pages and corresponding PMU | |
4730 | * data. Note that after rb::aux_mmap_count dropped to zero, | |
4731 | * they won't start any more (see perf_aux_output_begin()). | |
4732 | */ | |
4733 | perf_pmu_output_stop(event); | |
4734 | ||
4735 | /* now it's safe to free the pages */ | |
45bfb2e5 PZ |
4736 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); |
4737 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4738 | ||
95ff4ca2 | 4739 | /* this has to be the last one */ |
45bfb2e5 | 4740 | rb_free_aux(rb); |
95ff4ca2 AS |
4741 | WARN_ON_ONCE(atomic_read(&rb->aux_refcount)); |
4742 | ||
45bfb2e5 PZ |
4743 | mutex_unlock(&event->mmap_mutex); |
4744 | } | |
4745 | ||
9bb5d40c PZ |
4746 | atomic_dec(&rb->mmap_count); |
4747 | ||
4748 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4749 | goto out_put; |
9bb5d40c | 4750 | |
b69cf536 | 4751 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4752 | mutex_unlock(&event->mmap_mutex); |
4753 | ||
4754 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4755 | if (atomic_read(&rb->mmap_count)) |
4756 | goto out_put; | |
ac9721f3 | 4757 | |
9bb5d40c PZ |
4758 | /* |
4759 | * No other mmap()s, detach from all other events that might redirect | |
4760 | * into the now unreachable buffer. Somewhat complicated by the | |
4761 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4762 | */ | |
4763 | again: | |
4764 | rcu_read_lock(); | |
4765 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4766 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4767 | /* | |
4768 | * This event is en-route to free_event() which will | |
4769 | * detach it and remove it from the list. | |
4770 | */ | |
4771 | continue; | |
4772 | } | |
4773 | rcu_read_unlock(); | |
789f90fc | 4774 | |
9bb5d40c PZ |
4775 | mutex_lock(&event->mmap_mutex); |
4776 | /* | |
4777 | * Check we didn't race with perf_event_set_output() which can | |
4778 | * swizzle the rb from under us while we were waiting to | |
4779 | * acquire mmap_mutex. | |
4780 | * | |
4781 | * If we find a different rb; ignore this event, a next | |
4782 | * iteration will no longer find it on the list. We have to | |
4783 | * still restart the iteration to make sure we're not now | |
4784 | * iterating the wrong list. | |
4785 | */ | |
b69cf536 PZ |
4786 | if (event->rb == rb) |
4787 | ring_buffer_attach(event, NULL); | |
4788 | ||
cdd6c482 | 4789 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4790 | put_event(event); |
ac9721f3 | 4791 | |
9bb5d40c PZ |
4792 | /* |
4793 | * Restart the iteration; either we're on the wrong list or | |
4794 | * destroyed its integrity by doing a deletion. | |
4795 | */ | |
4796 | goto again; | |
7b732a75 | 4797 | } |
9bb5d40c PZ |
4798 | rcu_read_unlock(); |
4799 | ||
4800 | /* | |
4801 | * It could be there's still a few 0-ref events on the list; they'll | |
4802 | * get cleaned up by free_event() -- they'll also still have their | |
4803 | * ref on the rb and will free it whenever they are done with it. | |
4804 | * | |
4805 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4806 | * undo the VM accounting. | |
4807 | */ | |
4808 | ||
4809 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4810 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4811 | free_uid(mmap_user); | |
4812 | ||
b69cf536 | 4813 | out_put: |
9bb5d40c | 4814 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4815 | } |
4816 | ||
f0f37e2f | 4817 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4818 | .open = perf_mmap_open, |
45bfb2e5 | 4819 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4820 | .fault = perf_mmap_fault, |
4821 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4822 | }; |
4823 | ||
4824 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4825 | { | |
cdd6c482 | 4826 | struct perf_event *event = file->private_data; |
22a4f650 | 4827 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4828 | struct user_struct *user = current_user(); |
22a4f650 | 4829 | unsigned long locked, lock_limit; |
45bfb2e5 | 4830 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4831 | unsigned long vma_size; |
4832 | unsigned long nr_pages; | |
45bfb2e5 | 4833 | long user_extra = 0, extra = 0; |
d57e34fd | 4834 | int ret = 0, flags = 0; |
37d81828 | 4835 | |
c7920614 PZ |
4836 | /* |
4837 | * Don't allow mmap() of inherited per-task counters. This would | |
4838 | * create a performance issue due to all children writing to the | |
76369139 | 4839 | * same rb. |
c7920614 PZ |
4840 | */ |
4841 | if (event->cpu == -1 && event->attr.inherit) | |
4842 | return -EINVAL; | |
4843 | ||
43a21ea8 | 4844 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4845 | return -EINVAL; |
7b732a75 PZ |
4846 | |
4847 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4848 | |
4849 | if (vma->vm_pgoff == 0) { | |
4850 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4851 | } else { | |
4852 | /* | |
4853 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4854 | * mapped, all subsequent mappings should have the same size | |
4855 | * and offset. Must be above the normal perf buffer. | |
4856 | */ | |
4857 | u64 aux_offset, aux_size; | |
4858 | ||
4859 | if (!event->rb) | |
4860 | return -EINVAL; | |
4861 | ||
4862 | nr_pages = vma_size / PAGE_SIZE; | |
4863 | ||
4864 | mutex_lock(&event->mmap_mutex); | |
4865 | ret = -EINVAL; | |
4866 | ||
4867 | rb = event->rb; | |
4868 | if (!rb) | |
4869 | goto aux_unlock; | |
4870 | ||
4871 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4872 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4873 | ||
4874 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4875 | goto aux_unlock; | |
4876 | ||
4877 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4878 | goto aux_unlock; | |
4879 | ||
4880 | /* already mapped with a different offset */ | |
4881 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4882 | goto aux_unlock; | |
4883 | ||
4884 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4885 | goto aux_unlock; | |
4886 | ||
4887 | /* already mapped with a different size */ | |
4888 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4889 | goto aux_unlock; | |
4890 | ||
4891 | if (!is_power_of_2(nr_pages)) | |
4892 | goto aux_unlock; | |
4893 | ||
4894 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4895 | goto aux_unlock; | |
4896 | ||
4897 | if (rb_has_aux(rb)) { | |
4898 | atomic_inc(&rb->aux_mmap_count); | |
4899 | ret = 0; | |
4900 | goto unlock; | |
4901 | } | |
4902 | ||
4903 | atomic_set(&rb->aux_mmap_count, 1); | |
4904 | user_extra = nr_pages; | |
4905 | ||
4906 | goto accounting; | |
4907 | } | |
7b732a75 | 4908 | |
7730d865 | 4909 | /* |
76369139 | 4910 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4911 | * can do bitmasks instead of modulo. |
4912 | */ | |
2ed11312 | 4913 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4914 | return -EINVAL; |
4915 | ||
7b732a75 | 4916 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4917 | return -EINVAL; |
4918 | ||
cdd6c482 | 4919 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4920 | again: |
cdd6c482 | 4921 | mutex_lock(&event->mmap_mutex); |
76369139 | 4922 | if (event->rb) { |
9bb5d40c | 4923 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4924 | ret = -EINVAL; |
9bb5d40c PZ |
4925 | goto unlock; |
4926 | } | |
4927 | ||
4928 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4929 | /* | |
4930 | * Raced against perf_mmap_close() through | |
4931 | * perf_event_set_output(). Try again, hope for better | |
4932 | * luck. | |
4933 | */ | |
4934 | mutex_unlock(&event->mmap_mutex); | |
4935 | goto again; | |
4936 | } | |
4937 | ||
ebb3c4c4 PZ |
4938 | goto unlock; |
4939 | } | |
4940 | ||
789f90fc | 4941 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4942 | |
4943 | accounting: | |
cdd6c482 | 4944 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4945 | |
4946 | /* | |
4947 | * Increase the limit linearly with more CPUs: | |
4948 | */ | |
4949 | user_lock_limit *= num_online_cpus(); | |
4950 | ||
789f90fc | 4951 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4952 | |
789f90fc PZ |
4953 | if (user_locked > user_lock_limit) |
4954 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4955 | |
78d7d407 | 4956 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4957 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4958 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4959 | |
459ec28a IM |
4960 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4961 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4962 | ret = -EPERM; |
4963 | goto unlock; | |
4964 | } | |
7b732a75 | 4965 | |
45bfb2e5 | 4966 | WARN_ON(!rb && event->rb); |
906010b2 | 4967 | |
d57e34fd | 4968 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4969 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4970 | |
76369139 | 4971 | if (!rb) { |
45bfb2e5 PZ |
4972 | rb = rb_alloc(nr_pages, |
4973 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4974 | event->cpu, flags); | |
26cb63ad | 4975 | |
45bfb2e5 PZ |
4976 | if (!rb) { |
4977 | ret = -ENOMEM; | |
4978 | goto unlock; | |
4979 | } | |
43a21ea8 | 4980 | |
45bfb2e5 PZ |
4981 | atomic_set(&rb->mmap_count, 1); |
4982 | rb->mmap_user = get_current_user(); | |
4983 | rb->mmap_locked = extra; | |
26cb63ad | 4984 | |
45bfb2e5 | 4985 | ring_buffer_attach(event, rb); |
ac9721f3 | 4986 | |
45bfb2e5 PZ |
4987 | perf_event_init_userpage(event); |
4988 | perf_event_update_userpage(event); | |
4989 | } else { | |
1a594131 AS |
4990 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4991 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4992 | if (!ret) |
4993 | rb->aux_mmap_locked = extra; | |
4994 | } | |
9a0f05cb | 4995 | |
ebb3c4c4 | 4996 | unlock: |
45bfb2e5 PZ |
4997 | if (!ret) { |
4998 | atomic_long_add(user_extra, &user->locked_vm); | |
4999 | vma->vm_mm->pinned_vm += extra; | |
5000 | ||
ac9721f3 | 5001 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
5002 | } else if (rb) { |
5003 | atomic_dec(&rb->mmap_count); | |
5004 | } | |
5005 | aux_unlock: | |
cdd6c482 | 5006 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 5007 | |
9bb5d40c PZ |
5008 | /* |
5009 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
5010 | * vma. | |
5011 | */ | |
26cb63ad | 5012 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 5013 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 5014 | |
1e0fb9ec AL |
5015 | if (event->pmu->event_mapped) |
5016 | event->pmu->event_mapped(event); | |
5017 | ||
7b732a75 | 5018 | return ret; |
37d81828 PM |
5019 | } |
5020 | ||
3c446b3d PZ |
5021 | static int perf_fasync(int fd, struct file *filp, int on) |
5022 | { | |
496ad9aa | 5023 | struct inode *inode = file_inode(filp); |
cdd6c482 | 5024 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
5025 | int retval; |
5026 | ||
5955102c | 5027 | inode_lock(inode); |
cdd6c482 | 5028 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 5029 | inode_unlock(inode); |
3c446b3d PZ |
5030 | |
5031 | if (retval < 0) | |
5032 | return retval; | |
5033 | ||
5034 | return 0; | |
5035 | } | |
5036 | ||
0793a61d | 5037 | static const struct file_operations perf_fops = { |
3326c1ce | 5038 | .llseek = no_llseek, |
0793a61d TG |
5039 | .release = perf_release, |
5040 | .read = perf_read, | |
5041 | .poll = perf_poll, | |
d859e29f | 5042 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 5043 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 5044 | .mmap = perf_mmap, |
3c446b3d | 5045 | .fasync = perf_fasync, |
0793a61d TG |
5046 | }; |
5047 | ||
925d519a | 5048 | /* |
cdd6c482 | 5049 | * Perf event wakeup |
925d519a PZ |
5050 | * |
5051 | * If there's data, ensure we set the poll() state and publish everything | |
5052 | * to user-space before waking everybody up. | |
5053 | */ | |
5054 | ||
fed66e2c PZ |
5055 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
5056 | { | |
5057 | /* only the parent has fasync state */ | |
5058 | if (event->parent) | |
5059 | event = event->parent; | |
5060 | return &event->fasync; | |
5061 | } | |
5062 | ||
cdd6c482 | 5063 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 5064 | { |
10c6db11 | 5065 | ring_buffer_wakeup(event); |
4c9e2542 | 5066 | |
cdd6c482 | 5067 | if (event->pending_kill) { |
fed66e2c | 5068 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 5069 | event->pending_kill = 0; |
4c9e2542 | 5070 | } |
925d519a PZ |
5071 | } |
5072 | ||
e360adbe | 5073 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 5074 | { |
cdd6c482 IM |
5075 | struct perf_event *event = container_of(entry, |
5076 | struct perf_event, pending); | |
d525211f PZ |
5077 | int rctx; |
5078 | ||
5079 | rctx = perf_swevent_get_recursion_context(); | |
5080 | /* | |
5081 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
5082 | * and we won't recurse 'further'. | |
5083 | */ | |
79f14641 | 5084 | |
cdd6c482 IM |
5085 | if (event->pending_disable) { |
5086 | event->pending_disable = 0; | |
fae3fde6 | 5087 | perf_event_disable_local(event); |
79f14641 PZ |
5088 | } |
5089 | ||
cdd6c482 IM |
5090 | if (event->pending_wakeup) { |
5091 | event->pending_wakeup = 0; | |
5092 | perf_event_wakeup(event); | |
79f14641 | 5093 | } |
d525211f PZ |
5094 | |
5095 | if (rctx >= 0) | |
5096 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
5097 | } |
5098 | ||
39447b38 ZY |
5099 | /* |
5100 | * We assume there is only KVM supporting the callbacks. | |
5101 | * Later on, we might change it to a list if there is | |
5102 | * another virtualization implementation supporting the callbacks. | |
5103 | */ | |
5104 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
5105 | ||
5106 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5107 | { | |
5108 | perf_guest_cbs = cbs; | |
5109 | return 0; | |
5110 | } | |
5111 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
5112 | ||
5113 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5114 | { | |
5115 | perf_guest_cbs = NULL; | |
5116 | return 0; | |
5117 | } | |
5118 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5119 | ||
4018994f JO |
5120 | static void |
5121 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5122 | struct pt_regs *regs, u64 mask) | |
5123 | { | |
5124 | int bit; | |
5125 | ||
5126 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
5127 | sizeof(mask) * BITS_PER_BYTE) { | |
5128 | u64 val; | |
5129 | ||
5130 | val = perf_reg_value(regs, bit); | |
5131 | perf_output_put(handle, val); | |
5132 | } | |
5133 | } | |
5134 | ||
60e2364e | 5135 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5136 | struct pt_regs *regs, |
5137 | struct pt_regs *regs_user_copy) | |
4018994f | 5138 | { |
88a7c26a AL |
5139 | if (user_mode(regs)) { |
5140 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5141 | regs_user->regs = regs; |
88a7c26a AL |
5142 | } else if (current->mm) { |
5143 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5144 | } else { |
5145 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5146 | regs_user->regs = NULL; | |
4018994f JO |
5147 | } |
5148 | } | |
5149 | ||
60e2364e SE |
5150 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5151 | struct pt_regs *regs) | |
5152 | { | |
5153 | regs_intr->regs = regs; | |
5154 | regs_intr->abi = perf_reg_abi(current); | |
5155 | } | |
5156 | ||
5157 | ||
c5ebcedb JO |
5158 | /* |
5159 | * Get remaining task size from user stack pointer. | |
5160 | * | |
5161 | * It'd be better to take stack vma map and limit this more | |
5162 | * precisly, but there's no way to get it safely under interrupt, | |
5163 | * so using TASK_SIZE as limit. | |
5164 | */ | |
5165 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5166 | { | |
5167 | unsigned long addr = perf_user_stack_pointer(regs); | |
5168 | ||
5169 | if (!addr || addr >= TASK_SIZE) | |
5170 | return 0; | |
5171 | ||
5172 | return TASK_SIZE - addr; | |
5173 | } | |
5174 | ||
5175 | static u16 | |
5176 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5177 | struct pt_regs *regs) | |
5178 | { | |
5179 | u64 task_size; | |
5180 | ||
5181 | /* No regs, no stack pointer, no dump. */ | |
5182 | if (!regs) | |
5183 | return 0; | |
5184 | ||
5185 | /* | |
5186 | * Check if we fit in with the requested stack size into the: | |
5187 | * - TASK_SIZE | |
5188 | * If we don't, we limit the size to the TASK_SIZE. | |
5189 | * | |
5190 | * - remaining sample size | |
5191 | * If we don't, we customize the stack size to | |
5192 | * fit in to the remaining sample size. | |
5193 | */ | |
5194 | ||
5195 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5196 | stack_size = min(stack_size, (u16) task_size); | |
5197 | ||
5198 | /* Current header size plus static size and dynamic size. */ | |
5199 | header_size += 2 * sizeof(u64); | |
5200 | ||
5201 | /* Do we fit in with the current stack dump size? */ | |
5202 | if ((u16) (header_size + stack_size) < header_size) { | |
5203 | /* | |
5204 | * If we overflow the maximum size for the sample, | |
5205 | * we customize the stack dump size to fit in. | |
5206 | */ | |
5207 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5208 | stack_size = round_up(stack_size, sizeof(u64)); | |
5209 | } | |
5210 | ||
5211 | return stack_size; | |
5212 | } | |
5213 | ||
5214 | static void | |
5215 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5216 | struct pt_regs *regs) | |
5217 | { | |
5218 | /* Case of a kernel thread, nothing to dump */ | |
5219 | if (!regs) { | |
5220 | u64 size = 0; | |
5221 | perf_output_put(handle, size); | |
5222 | } else { | |
5223 | unsigned long sp; | |
5224 | unsigned int rem; | |
5225 | u64 dyn_size; | |
5226 | ||
5227 | /* | |
5228 | * We dump: | |
5229 | * static size | |
5230 | * - the size requested by user or the best one we can fit | |
5231 | * in to the sample max size | |
5232 | * data | |
5233 | * - user stack dump data | |
5234 | * dynamic size | |
5235 | * - the actual dumped size | |
5236 | */ | |
5237 | ||
5238 | /* Static size. */ | |
5239 | perf_output_put(handle, dump_size); | |
5240 | ||
5241 | /* Data. */ | |
5242 | sp = perf_user_stack_pointer(regs); | |
5243 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5244 | dyn_size = dump_size - rem; | |
5245 | ||
5246 | perf_output_skip(handle, rem); | |
5247 | ||
5248 | /* Dynamic size. */ | |
5249 | perf_output_put(handle, dyn_size); | |
5250 | } | |
5251 | } | |
5252 | ||
c980d109 ACM |
5253 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5254 | struct perf_sample_data *data, | |
5255 | struct perf_event *event) | |
6844c09d ACM |
5256 | { |
5257 | u64 sample_type = event->attr.sample_type; | |
5258 | ||
5259 | data->type = sample_type; | |
5260 | header->size += event->id_header_size; | |
5261 | ||
5262 | if (sample_type & PERF_SAMPLE_TID) { | |
5263 | /* namespace issues */ | |
5264 | data->tid_entry.pid = perf_event_pid(event, current); | |
5265 | data->tid_entry.tid = perf_event_tid(event, current); | |
5266 | } | |
5267 | ||
5268 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5269 | data->time = perf_event_clock(event); |
6844c09d | 5270 | |
ff3d527c | 5271 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5272 | data->id = primary_event_id(event); |
5273 | ||
5274 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5275 | data->stream_id = event->id; | |
5276 | ||
5277 | if (sample_type & PERF_SAMPLE_CPU) { | |
5278 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5279 | data->cpu_entry.reserved = 0; | |
5280 | } | |
5281 | } | |
5282 | ||
76369139 FW |
5283 | void perf_event_header__init_id(struct perf_event_header *header, |
5284 | struct perf_sample_data *data, | |
5285 | struct perf_event *event) | |
c980d109 ACM |
5286 | { |
5287 | if (event->attr.sample_id_all) | |
5288 | __perf_event_header__init_id(header, data, event); | |
5289 | } | |
5290 | ||
5291 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5292 | struct perf_sample_data *data) | |
5293 | { | |
5294 | u64 sample_type = data->type; | |
5295 | ||
5296 | if (sample_type & PERF_SAMPLE_TID) | |
5297 | perf_output_put(handle, data->tid_entry); | |
5298 | ||
5299 | if (sample_type & PERF_SAMPLE_TIME) | |
5300 | perf_output_put(handle, data->time); | |
5301 | ||
5302 | if (sample_type & PERF_SAMPLE_ID) | |
5303 | perf_output_put(handle, data->id); | |
5304 | ||
5305 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5306 | perf_output_put(handle, data->stream_id); | |
5307 | ||
5308 | if (sample_type & PERF_SAMPLE_CPU) | |
5309 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5310 | |
5311 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5312 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5313 | } |
5314 | ||
76369139 FW |
5315 | void perf_event__output_id_sample(struct perf_event *event, |
5316 | struct perf_output_handle *handle, | |
5317 | struct perf_sample_data *sample) | |
c980d109 ACM |
5318 | { |
5319 | if (event->attr.sample_id_all) | |
5320 | __perf_event__output_id_sample(handle, sample); | |
5321 | } | |
5322 | ||
3dab77fb | 5323 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5324 | struct perf_event *event, |
5325 | u64 enabled, u64 running) | |
3dab77fb | 5326 | { |
cdd6c482 | 5327 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5328 | u64 values[4]; |
5329 | int n = 0; | |
5330 | ||
b5e58793 | 5331 | values[n++] = perf_event_count(event); |
3dab77fb | 5332 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5333 | values[n++] = enabled + |
cdd6c482 | 5334 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5335 | } |
5336 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5337 | values[n++] = running + |
cdd6c482 | 5338 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5339 | } |
5340 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5341 | values[n++] = primary_event_id(event); |
3dab77fb | 5342 | |
76369139 | 5343 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5344 | } |
5345 | ||
5346 | /* | |
cdd6c482 | 5347 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5348 | */ |
5349 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5350 | struct perf_event *event, |
5351 | u64 enabled, u64 running) | |
3dab77fb | 5352 | { |
cdd6c482 IM |
5353 | struct perf_event *leader = event->group_leader, *sub; |
5354 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5355 | u64 values[5]; |
5356 | int n = 0; | |
5357 | ||
5358 | values[n++] = 1 + leader->nr_siblings; | |
5359 | ||
5360 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5361 | values[n++] = enabled; |
3dab77fb PZ |
5362 | |
5363 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5364 | values[n++] = running; |
3dab77fb | 5365 | |
cdd6c482 | 5366 | if (leader != event) |
3dab77fb PZ |
5367 | leader->pmu->read(leader); |
5368 | ||
b5e58793 | 5369 | values[n++] = perf_event_count(leader); |
3dab77fb | 5370 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5371 | values[n++] = primary_event_id(leader); |
3dab77fb | 5372 | |
76369139 | 5373 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5374 | |
65abc865 | 5375 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5376 | n = 0; |
5377 | ||
6f5ab001 JO |
5378 | if ((sub != event) && |
5379 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5380 | sub->pmu->read(sub); |
5381 | ||
b5e58793 | 5382 | values[n++] = perf_event_count(sub); |
3dab77fb | 5383 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5384 | values[n++] = primary_event_id(sub); |
3dab77fb | 5385 | |
76369139 | 5386 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5387 | } |
5388 | } | |
5389 | ||
eed01528 SE |
5390 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5391 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5392 | ||
3dab77fb | 5393 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5394 | struct perf_event *event) |
3dab77fb | 5395 | { |
e3f3541c | 5396 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5397 | u64 read_format = event->attr.read_format; |
5398 | ||
5399 | /* | |
5400 | * compute total_time_enabled, total_time_running | |
5401 | * based on snapshot values taken when the event | |
5402 | * was last scheduled in. | |
5403 | * | |
5404 | * we cannot simply called update_context_time() | |
5405 | * because of locking issue as we are called in | |
5406 | * NMI context | |
5407 | */ | |
c4794295 | 5408 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5409 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5410 | |
cdd6c482 | 5411 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5412 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5413 | else |
eed01528 | 5414 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5415 | } |
5416 | ||
5622f295 MM |
5417 | void perf_output_sample(struct perf_output_handle *handle, |
5418 | struct perf_event_header *header, | |
5419 | struct perf_sample_data *data, | |
cdd6c482 | 5420 | struct perf_event *event) |
5622f295 MM |
5421 | { |
5422 | u64 sample_type = data->type; | |
5423 | ||
5424 | perf_output_put(handle, *header); | |
5425 | ||
ff3d527c AH |
5426 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5427 | perf_output_put(handle, data->id); | |
5428 | ||
5622f295 MM |
5429 | if (sample_type & PERF_SAMPLE_IP) |
5430 | perf_output_put(handle, data->ip); | |
5431 | ||
5432 | if (sample_type & PERF_SAMPLE_TID) | |
5433 | perf_output_put(handle, data->tid_entry); | |
5434 | ||
5435 | if (sample_type & PERF_SAMPLE_TIME) | |
5436 | perf_output_put(handle, data->time); | |
5437 | ||
5438 | if (sample_type & PERF_SAMPLE_ADDR) | |
5439 | perf_output_put(handle, data->addr); | |
5440 | ||
5441 | if (sample_type & PERF_SAMPLE_ID) | |
5442 | perf_output_put(handle, data->id); | |
5443 | ||
5444 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5445 | perf_output_put(handle, data->stream_id); | |
5446 | ||
5447 | if (sample_type & PERF_SAMPLE_CPU) | |
5448 | perf_output_put(handle, data->cpu_entry); | |
5449 | ||
5450 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5451 | perf_output_put(handle, data->period); | |
5452 | ||
5453 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5454 | perf_output_read(handle, event); |
5622f295 MM |
5455 | |
5456 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5457 | if (data->callchain) { | |
5458 | int size = 1; | |
5459 | ||
5460 | if (data->callchain) | |
5461 | size += data->callchain->nr; | |
5462 | ||
5463 | size *= sizeof(u64); | |
5464 | ||
76369139 | 5465 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5466 | } else { |
5467 | u64 nr = 0; | |
5468 | perf_output_put(handle, nr); | |
5469 | } | |
5470 | } | |
5471 | ||
5472 | if (sample_type & PERF_SAMPLE_RAW) { | |
5473 | if (data->raw) { | |
fa128e6a AS |
5474 | u32 raw_size = data->raw->size; |
5475 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5476 | sizeof(u64)) - sizeof(u32); | |
5477 | u64 zero = 0; | |
5478 | ||
5479 | perf_output_put(handle, real_size); | |
5480 | __output_copy(handle, data->raw->data, raw_size); | |
5481 | if (real_size - raw_size) | |
5482 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5483 | } else { |
5484 | struct { | |
5485 | u32 size; | |
5486 | u32 data; | |
5487 | } raw = { | |
5488 | .size = sizeof(u32), | |
5489 | .data = 0, | |
5490 | }; | |
5491 | perf_output_put(handle, raw); | |
5492 | } | |
5493 | } | |
a7ac67ea | 5494 | |
bce38cd5 SE |
5495 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5496 | if (data->br_stack) { | |
5497 | size_t size; | |
5498 | ||
5499 | size = data->br_stack->nr | |
5500 | * sizeof(struct perf_branch_entry); | |
5501 | ||
5502 | perf_output_put(handle, data->br_stack->nr); | |
5503 | perf_output_copy(handle, data->br_stack->entries, size); | |
5504 | } else { | |
5505 | /* | |
5506 | * we always store at least the value of nr | |
5507 | */ | |
5508 | u64 nr = 0; | |
5509 | perf_output_put(handle, nr); | |
5510 | } | |
5511 | } | |
4018994f JO |
5512 | |
5513 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5514 | u64 abi = data->regs_user.abi; | |
5515 | ||
5516 | /* | |
5517 | * If there are no regs to dump, notice it through | |
5518 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5519 | */ | |
5520 | perf_output_put(handle, abi); | |
5521 | ||
5522 | if (abi) { | |
5523 | u64 mask = event->attr.sample_regs_user; | |
5524 | perf_output_sample_regs(handle, | |
5525 | data->regs_user.regs, | |
5526 | mask); | |
5527 | } | |
5528 | } | |
c5ebcedb | 5529 | |
a5cdd40c | 5530 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5531 | perf_output_sample_ustack(handle, |
5532 | data->stack_user_size, | |
5533 | data->regs_user.regs); | |
a5cdd40c | 5534 | } |
c3feedf2 AK |
5535 | |
5536 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5537 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5538 | |
5539 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5540 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5541 | |
fdfbbd07 AK |
5542 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5543 | perf_output_put(handle, data->txn); | |
5544 | ||
60e2364e SE |
5545 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5546 | u64 abi = data->regs_intr.abi; | |
5547 | /* | |
5548 | * If there are no regs to dump, notice it through | |
5549 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5550 | */ | |
5551 | perf_output_put(handle, abi); | |
5552 | ||
5553 | if (abi) { | |
5554 | u64 mask = event->attr.sample_regs_intr; | |
5555 | ||
5556 | perf_output_sample_regs(handle, | |
5557 | data->regs_intr.regs, | |
5558 | mask); | |
5559 | } | |
5560 | } | |
5561 | ||
a5cdd40c PZ |
5562 | if (!event->attr.watermark) { |
5563 | int wakeup_events = event->attr.wakeup_events; | |
5564 | ||
5565 | if (wakeup_events) { | |
5566 | struct ring_buffer *rb = handle->rb; | |
5567 | int events = local_inc_return(&rb->events); | |
5568 | ||
5569 | if (events >= wakeup_events) { | |
5570 | local_sub(wakeup_events, &rb->events); | |
5571 | local_inc(&rb->wakeup); | |
5572 | } | |
5573 | } | |
5574 | } | |
5622f295 MM |
5575 | } |
5576 | ||
5577 | void perf_prepare_sample(struct perf_event_header *header, | |
5578 | struct perf_sample_data *data, | |
cdd6c482 | 5579 | struct perf_event *event, |
5622f295 | 5580 | struct pt_regs *regs) |
7b732a75 | 5581 | { |
cdd6c482 | 5582 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5583 | |
cdd6c482 | 5584 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5585 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5586 | |
5587 | header->misc = 0; | |
5588 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5589 | |
c980d109 | 5590 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5591 | |
c320c7b7 | 5592 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5593 | data->ip = perf_instruction_pointer(regs); |
5594 | ||
b23f3325 | 5595 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5596 | int size = 1; |
394ee076 | 5597 | |
e6dab5ff | 5598 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5599 | |
5600 | if (data->callchain) | |
5601 | size += data->callchain->nr; | |
5602 | ||
5603 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5604 | } |
5605 | ||
3a43ce68 | 5606 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5607 | int size = sizeof(u32); |
5608 | ||
5609 | if (data->raw) | |
5610 | size += data->raw->size; | |
5611 | else | |
5612 | size += sizeof(u32); | |
5613 | ||
fa128e6a | 5614 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5615 | } |
bce38cd5 SE |
5616 | |
5617 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5618 | int size = sizeof(u64); /* nr */ | |
5619 | if (data->br_stack) { | |
5620 | size += data->br_stack->nr | |
5621 | * sizeof(struct perf_branch_entry); | |
5622 | } | |
5623 | header->size += size; | |
5624 | } | |
4018994f | 5625 | |
2565711f | 5626 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5627 | perf_sample_regs_user(&data->regs_user, regs, |
5628 | &data->regs_user_copy); | |
2565711f | 5629 | |
4018994f JO |
5630 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5631 | /* regs dump ABI info */ | |
5632 | int size = sizeof(u64); | |
5633 | ||
4018994f JO |
5634 | if (data->regs_user.regs) { |
5635 | u64 mask = event->attr.sample_regs_user; | |
5636 | size += hweight64(mask) * sizeof(u64); | |
5637 | } | |
5638 | ||
5639 | header->size += size; | |
5640 | } | |
c5ebcedb JO |
5641 | |
5642 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5643 | /* | |
5644 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5645 | * processed as the last one or have additional check added | |
5646 | * in case new sample type is added, because we could eat | |
5647 | * up the rest of the sample size. | |
5648 | */ | |
c5ebcedb JO |
5649 | u16 stack_size = event->attr.sample_stack_user; |
5650 | u16 size = sizeof(u64); | |
5651 | ||
c5ebcedb | 5652 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5653 | data->regs_user.regs); |
c5ebcedb JO |
5654 | |
5655 | /* | |
5656 | * If there is something to dump, add space for the dump | |
5657 | * itself and for the field that tells the dynamic size, | |
5658 | * which is how many have been actually dumped. | |
5659 | */ | |
5660 | if (stack_size) | |
5661 | size += sizeof(u64) + stack_size; | |
5662 | ||
5663 | data->stack_user_size = stack_size; | |
5664 | header->size += size; | |
5665 | } | |
60e2364e SE |
5666 | |
5667 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5668 | /* regs dump ABI info */ | |
5669 | int size = sizeof(u64); | |
5670 | ||
5671 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5672 | ||
5673 | if (data->regs_intr.regs) { | |
5674 | u64 mask = event->attr.sample_regs_intr; | |
5675 | ||
5676 | size += hweight64(mask) * sizeof(u64); | |
5677 | } | |
5678 | ||
5679 | header->size += size; | |
5680 | } | |
5622f295 | 5681 | } |
7f453c24 | 5682 | |
21509084 YZ |
5683 | void perf_event_output(struct perf_event *event, |
5684 | struct perf_sample_data *data, | |
5685 | struct pt_regs *regs) | |
5622f295 MM |
5686 | { |
5687 | struct perf_output_handle handle; | |
5688 | struct perf_event_header header; | |
689802b2 | 5689 | |
927c7a9e FW |
5690 | /* protect the callchain buffers */ |
5691 | rcu_read_lock(); | |
5692 | ||
cdd6c482 | 5693 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5694 | |
a7ac67ea | 5695 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5696 | goto exit; |
0322cd6e | 5697 | |
cdd6c482 | 5698 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5699 | |
8a057d84 | 5700 | perf_output_end(&handle); |
927c7a9e FW |
5701 | |
5702 | exit: | |
5703 | rcu_read_unlock(); | |
0322cd6e PZ |
5704 | } |
5705 | ||
38b200d6 | 5706 | /* |
cdd6c482 | 5707 | * read event_id |
38b200d6 PZ |
5708 | */ |
5709 | ||
5710 | struct perf_read_event { | |
5711 | struct perf_event_header header; | |
5712 | ||
5713 | u32 pid; | |
5714 | u32 tid; | |
38b200d6 PZ |
5715 | }; |
5716 | ||
5717 | static void | |
cdd6c482 | 5718 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5719 | struct task_struct *task) |
5720 | { | |
5721 | struct perf_output_handle handle; | |
c980d109 | 5722 | struct perf_sample_data sample; |
dfc65094 | 5723 | struct perf_read_event read_event = { |
38b200d6 | 5724 | .header = { |
cdd6c482 | 5725 | .type = PERF_RECORD_READ, |
38b200d6 | 5726 | .misc = 0, |
c320c7b7 | 5727 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5728 | }, |
cdd6c482 IM |
5729 | .pid = perf_event_pid(event, task), |
5730 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5731 | }; |
3dab77fb | 5732 | int ret; |
38b200d6 | 5733 | |
c980d109 | 5734 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5735 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5736 | if (ret) |
5737 | return; | |
5738 | ||
dfc65094 | 5739 | perf_output_put(&handle, read_event); |
cdd6c482 | 5740 | perf_output_read(&handle, event); |
c980d109 | 5741 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5742 | |
38b200d6 PZ |
5743 | perf_output_end(&handle); |
5744 | } | |
5745 | ||
52d857a8 JO |
5746 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5747 | ||
5748 | static void | |
5749 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5750 | perf_event_aux_output_cb output, |
5751 | void *data) | |
5752 | { | |
5753 | struct perf_event *event; | |
5754 | ||
5755 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5756 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5757 | continue; | |
5758 | if (!event_filter_match(event)) | |
5759 | continue; | |
67516844 | 5760 | output(event, data); |
52d857a8 JO |
5761 | } |
5762 | } | |
5763 | ||
4e93ad60 JO |
5764 | static void |
5765 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5766 | struct perf_event_context *task_ctx) | |
5767 | { | |
5768 | rcu_read_lock(); | |
5769 | preempt_disable(); | |
5770 | perf_event_aux_ctx(task_ctx, output, data); | |
5771 | preempt_enable(); | |
5772 | rcu_read_unlock(); | |
5773 | } | |
5774 | ||
52d857a8 | 5775 | static void |
67516844 | 5776 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5777 | struct perf_event_context *task_ctx) |
5778 | { | |
5779 | struct perf_cpu_context *cpuctx; | |
5780 | struct perf_event_context *ctx; | |
5781 | struct pmu *pmu; | |
5782 | int ctxn; | |
5783 | ||
4e93ad60 JO |
5784 | /* |
5785 | * If we have task_ctx != NULL we only notify | |
5786 | * the task context itself. The task_ctx is set | |
5787 | * only for EXIT events before releasing task | |
5788 | * context. | |
5789 | */ | |
5790 | if (task_ctx) { | |
5791 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5792 | return; | |
5793 | } | |
5794 | ||
52d857a8 JO |
5795 | rcu_read_lock(); |
5796 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5797 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5798 | if (cpuctx->unique_pmu != pmu) | |
5799 | goto next; | |
67516844 | 5800 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5801 | ctxn = pmu->task_ctx_nr; |
5802 | if (ctxn < 0) | |
5803 | goto next; | |
5804 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5805 | if (ctx) | |
67516844 | 5806 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5807 | next: |
5808 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5809 | } | |
52d857a8 | 5810 | rcu_read_unlock(); |
95ff4ca2 AS |
5811 | } |
5812 | ||
5813 | struct remote_output { | |
5814 | struct ring_buffer *rb; | |
5815 | int err; | |
5816 | }; | |
5817 | ||
5818 | static void __perf_event_output_stop(struct perf_event *event, void *data) | |
5819 | { | |
5820 | struct perf_event *parent = event->parent; | |
5821 | struct remote_output *ro = data; | |
5822 | struct ring_buffer *rb = ro->rb; | |
5823 | ||
5824 | if (!has_aux(event)) | |
5825 | return; | |
5826 | ||
5827 | if (!parent) | |
5828 | parent = event; | |
5829 | ||
5830 | /* | |
5831 | * In case of inheritance, it will be the parent that links to the | |
5832 | * ring-buffer, but it will be the child that's actually using it: | |
5833 | */ | |
5834 | if (rcu_dereference(parent->rb) == rb) | |
5835 | ro->err = __perf_event_stop(event); | |
5836 | } | |
5837 | ||
5838 | static int __perf_pmu_output_stop(void *info) | |
5839 | { | |
5840 | struct perf_event *event = info; | |
5841 | struct pmu *pmu = event->pmu; | |
5842 | struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5843 | struct remote_output ro = { | |
5844 | .rb = event->rb, | |
5845 | }; | |
5846 | ||
5847 | rcu_read_lock(); | |
5848 | perf_event_aux_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro); | |
5849 | if (cpuctx->task_ctx) | |
5850 | perf_event_aux_ctx(cpuctx->task_ctx, __perf_event_output_stop, | |
5851 | &ro); | |
5852 | rcu_read_unlock(); | |
5853 | ||
5854 | return ro.err; | |
5855 | } | |
5856 | ||
5857 | static void perf_pmu_output_stop(struct perf_event *event) | |
5858 | { | |
5859 | struct perf_event *iter; | |
5860 | int err, cpu; | |
5861 | ||
5862 | restart: | |
5863 | rcu_read_lock(); | |
5864 | list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { | |
5865 | /* | |
5866 | * For per-CPU events, we need to make sure that neither they | |
5867 | * nor their children are running; for cpu==-1 events it's | |
5868 | * sufficient to stop the event itself if it's active, since | |
5869 | * it can't have children. | |
5870 | */ | |
5871 | cpu = iter->cpu; | |
5872 | if (cpu == -1) | |
5873 | cpu = READ_ONCE(iter->oncpu); | |
5874 | ||
5875 | if (cpu == -1) | |
5876 | continue; | |
5877 | ||
5878 | err = cpu_function_call(cpu, __perf_pmu_output_stop, event); | |
5879 | if (err == -EAGAIN) { | |
5880 | rcu_read_unlock(); | |
5881 | goto restart; | |
5882 | } | |
5883 | } | |
5884 | rcu_read_unlock(); | |
52d857a8 JO |
5885 | } |
5886 | ||
60313ebe | 5887 | /* |
9f498cc5 PZ |
5888 | * task tracking -- fork/exit |
5889 | * | |
13d7a241 | 5890 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5891 | */ |
5892 | ||
9f498cc5 | 5893 | struct perf_task_event { |
3a80b4a3 | 5894 | struct task_struct *task; |
cdd6c482 | 5895 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5896 | |
5897 | struct { | |
5898 | struct perf_event_header header; | |
5899 | ||
5900 | u32 pid; | |
5901 | u32 ppid; | |
9f498cc5 PZ |
5902 | u32 tid; |
5903 | u32 ptid; | |
393b2ad8 | 5904 | u64 time; |
cdd6c482 | 5905 | } event_id; |
60313ebe PZ |
5906 | }; |
5907 | ||
67516844 JO |
5908 | static int perf_event_task_match(struct perf_event *event) |
5909 | { | |
13d7a241 SE |
5910 | return event->attr.comm || event->attr.mmap || |
5911 | event->attr.mmap2 || event->attr.mmap_data || | |
5912 | event->attr.task; | |
67516844 JO |
5913 | } |
5914 | ||
cdd6c482 | 5915 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5916 | void *data) |
60313ebe | 5917 | { |
52d857a8 | 5918 | struct perf_task_event *task_event = data; |
60313ebe | 5919 | struct perf_output_handle handle; |
c980d109 | 5920 | struct perf_sample_data sample; |
9f498cc5 | 5921 | struct task_struct *task = task_event->task; |
c980d109 | 5922 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5923 | |
67516844 JO |
5924 | if (!perf_event_task_match(event)) |
5925 | return; | |
5926 | ||
c980d109 | 5927 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5928 | |
c980d109 | 5929 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5930 | task_event->event_id.header.size); |
ef60777c | 5931 | if (ret) |
c980d109 | 5932 | goto out; |
60313ebe | 5933 | |
cdd6c482 IM |
5934 | task_event->event_id.pid = perf_event_pid(event, task); |
5935 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5936 | |
cdd6c482 IM |
5937 | task_event->event_id.tid = perf_event_tid(event, task); |
5938 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5939 | |
34f43927 PZ |
5940 | task_event->event_id.time = perf_event_clock(event); |
5941 | ||
cdd6c482 | 5942 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5943 | |
c980d109 ACM |
5944 | perf_event__output_id_sample(event, &handle, &sample); |
5945 | ||
60313ebe | 5946 | perf_output_end(&handle); |
c980d109 ACM |
5947 | out: |
5948 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5949 | } |
5950 | ||
cdd6c482 IM |
5951 | static void perf_event_task(struct task_struct *task, |
5952 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5953 | int new) |
60313ebe | 5954 | { |
9f498cc5 | 5955 | struct perf_task_event task_event; |
60313ebe | 5956 | |
cdd6c482 IM |
5957 | if (!atomic_read(&nr_comm_events) && |
5958 | !atomic_read(&nr_mmap_events) && | |
5959 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5960 | return; |
5961 | ||
9f498cc5 | 5962 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5963 | .task = task, |
5964 | .task_ctx = task_ctx, | |
cdd6c482 | 5965 | .event_id = { |
60313ebe | 5966 | .header = { |
cdd6c482 | 5967 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5968 | .misc = 0, |
cdd6c482 | 5969 | .size = sizeof(task_event.event_id), |
60313ebe | 5970 | }, |
573402db PZ |
5971 | /* .pid */ |
5972 | /* .ppid */ | |
9f498cc5 PZ |
5973 | /* .tid */ |
5974 | /* .ptid */ | |
34f43927 | 5975 | /* .time */ |
60313ebe PZ |
5976 | }, |
5977 | }; | |
5978 | ||
67516844 | 5979 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5980 | &task_event, |
5981 | task_ctx); | |
9f498cc5 PZ |
5982 | } |
5983 | ||
cdd6c482 | 5984 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5985 | { |
cdd6c482 | 5986 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5987 | } |
5988 | ||
8d1b2d93 PZ |
5989 | /* |
5990 | * comm tracking | |
5991 | */ | |
5992 | ||
5993 | struct perf_comm_event { | |
22a4f650 IM |
5994 | struct task_struct *task; |
5995 | char *comm; | |
8d1b2d93 PZ |
5996 | int comm_size; |
5997 | ||
5998 | struct { | |
5999 | struct perf_event_header header; | |
6000 | ||
6001 | u32 pid; | |
6002 | u32 tid; | |
cdd6c482 | 6003 | } event_id; |
8d1b2d93 PZ |
6004 | }; |
6005 | ||
67516844 JO |
6006 | static int perf_event_comm_match(struct perf_event *event) |
6007 | { | |
6008 | return event->attr.comm; | |
6009 | } | |
6010 | ||
cdd6c482 | 6011 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 6012 | void *data) |
8d1b2d93 | 6013 | { |
52d857a8 | 6014 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 6015 | struct perf_output_handle handle; |
c980d109 | 6016 | struct perf_sample_data sample; |
cdd6c482 | 6017 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
6018 | int ret; |
6019 | ||
67516844 JO |
6020 | if (!perf_event_comm_match(event)) |
6021 | return; | |
6022 | ||
c980d109 ACM |
6023 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
6024 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6025 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
6026 | |
6027 | if (ret) | |
c980d109 | 6028 | goto out; |
8d1b2d93 | 6029 | |
cdd6c482 IM |
6030 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
6031 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 6032 | |
cdd6c482 | 6033 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 6034 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 6035 | comm_event->comm_size); |
c980d109 ACM |
6036 | |
6037 | perf_event__output_id_sample(event, &handle, &sample); | |
6038 | ||
8d1b2d93 | 6039 | perf_output_end(&handle); |
c980d109 ACM |
6040 | out: |
6041 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
6042 | } |
6043 | ||
cdd6c482 | 6044 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 6045 | { |
413ee3b4 | 6046 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 6047 | unsigned int size; |
8d1b2d93 | 6048 | |
413ee3b4 | 6049 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 6050 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 6051 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
6052 | |
6053 | comm_event->comm = comm; | |
6054 | comm_event->comm_size = size; | |
6055 | ||
cdd6c482 | 6056 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 6057 | |
67516844 | 6058 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
6059 | comm_event, |
6060 | NULL); | |
8d1b2d93 PZ |
6061 | } |
6062 | ||
82b89778 | 6063 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 6064 | { |
9ee318a7 PZ |
6065 | struct perf_comm_event comm_event; |
6066 | ||
cdd6c482 | 6067 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 6068 | return; |
a63eaf34 | 6069 | |
9ee318a7 | 6070 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 6071 | .task = task, |
573402db PZ |
6072 | /* .comm */ |
6073 | /* .comm_size */ | |
cdd6c482 | 6074 | .event_id = { |
573402db | 6075 | .header = { |
cdd6c482 | 6076 | .type = PERF_RECORD_COMM, |
82b89778 | 6077 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
6078 | /* .size */ |
6079 | }, | |
6080 | /* .pid */ | |
6081 | /* .tid */ | |
8d1b2d93 PZ |
6082 | }, |
6083 | }; | |
6084 | ||
cdd6c482 | 6085 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
6086 | } |
6087 | ||
0a4a9391 PZ |
6088 | /* |
6089 | * mmap tracking | |
6090 | */ | |
6091 | ||
6092 | struct perf_mmap_event { | |
089dd79d PZ |
6093 | struct vm_area_struct *vma; |
6094 | ||
6095 | const char *file_name; | |
6096 | int file_size; | |
13d7a241 SE |
6097 | int maj, min; |
6098 | u64 ino; | |
6099 | u64 ino_generation; | |
f972eb63 | 6100 | u32 prot, flags; |
0a4a9391 PZ |
6101 | |
6102 | struct { | |
6103 | struct perf_event_header header; | |
6104 | ||
6105 | u32 pid; | |
6106 | u32 tid; | |
6107 | u64 start; | |
6108 | u64 len; | |
6109 | u64 pgoff; | |
cdd6c482 | 6110 | } event_id; |
0a4a9391 PZ |
6111 | }; |
6112 | ||
67516844 JO |
6113 | static int perf_event_mmap_match(struct perf_event *event, |
6114 | void *data) | |
6115 | { | |
6116 | struct perf_mmap_event *mmap_event = data; | |
6117 | struct vm_area_struct *vma = mmap_event->vma; | |
6118 | int executable = vma->vm_flags & VM_EXEC; | |
6119 | ||
6120 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 6121 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
6122 | } |
6123 | ||
cdd6c482 | 6124 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 6125 | void *data) |
0a4a9391 | 6126 | { |
52d857a8 | 6127 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 6128 | struct perf_output_handle handle; |
c980d109 | 6129 | struct perf_sample_data sample; |
cdd6c482 | 6130 | int size = mmap_event->event_id.header.size; |
c980d109 | 6131 | int ret; |
0a4a9391 | 6132 | |
67516844 JO |
6133 | if (!perf_event_mmap_match(event, data)) |
6134 | return; | |
6135 | ||
13d7a241 SE |
6136 | if (event->attr.mmap2) { |
6137 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
6138 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
6139 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
6140 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 6141 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
6142 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
6143 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
6144 | } |
6145 | ||
c980d109 ACM |
6146 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
6147 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6148 | mmap_event->event_id.header.size); |
0a4a9391 | 6149 | if (ret) |
c980d109 | 6150 | goto out; |
0a4a9391 | 6151 | |
cdd6c482 IM |
6152 | mmap_event->event_id.pid = perf_event_pid(event, current); |
6153 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 6154 | |
cdd6c482 | 6155 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
6156 | |
6157 | if (event->attr.mmap2) { | |
6158 | perf_output_put(&handle, mmap_event->maj); | |
6159 | perf_output_put(&handle, mmap_event->min); | |
6160 | perf_output_put(&handle, mmap_event->ino); | |
6161 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
6162 | perf_output_put(&handle, mmap_event->prot); |
6163 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
6164 | } |
6165 | ||
76369139 | 6166 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 6167 | mmap_event->file_size); |
c980d109 ACM |
6168 | |
6169 | perf_event__output_id_sample(event, &handle, &sample); | |
6170 | ||
78d613eb | 6171 | perf_output_end(&handle); |
c980d109 ACM |
6172 | out: |
6173 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
6174 | } |
6175 | ||
cdd6c482 | 6176 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 6177 | { |
089dd79d PZ |
6178 | struct vm_area_struct *vma = mmap_event->vma; |
6179 | struct file *file = vma->vm_file; | |
13d7a241 SE |
6180 | int maj = 0, min = 0; |
6181 | u64 ino = 0, gen = 0; | |
f972eb63 | 6182 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
6183 | unsigned int size; |
6184 | char tmp[16]; | |
6185 | char *buf = NULL; | |
2c42cfbf | 6186 | char *name; |
413ee3b4 | 6187 | |
0a4a9391 | 6188 | if (file) { |
13d7a241 SE |
6189 | struct inode *inode; |
6190 | dev_t dev; | |
3ea2f2b9 | 6191 | |
2c42cfbf | 6192 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 6193 | if (!buf) { |
c7e548b4 ON |
6194 | name = "//enomem"; |
6195 | goto cpy_name; | |
0a4a9391 | 6196 | } |
413ee3b4 | 6197 | /* |
3ea2f2b9 | 6198 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
6199 | * need to add enough zero bytes after the string to handle |
6200 | * the 64bit alignment we do later. | |
6201 | */ | |
9bf39ab2 | 6202 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 6203 | if (IS_ERR(name)) { |
c7e548b4 ON |
6204 | name = "//toolong"; |
6205 | goto cpy_name; | |
0a4a9391 | 6206 | } |
13d7a241 SE |
6207 | inode = file_inode(vma->vm_file); |
6208 | dev = inode->i_sb->s_dev; | |
6209 | ino = inode->i_ino; | |
6210 | gen = inode->i_generation; | |
6211 | maj = MAJOR(dev); | |
6212 | min = MINOR(dev); | |
f972eb63 PZ |
6213 | |
6214 | if (vma->vm_flags & VM_READ) | |
6215 | prot |= PROT_READ; | |
6216 | if (vma->vm_flags & VM_WRITE) | |
6217 | prot |= PROT_WRITE; | |
6218 | if (vma->vm_flags & VM_EXEC) | |
6219 | prot |= PROT_EXEC; | |
6220 | ||
6221 | if (vma->vm_flags & VM_MAYSHARE) | |
6222 | flags = MAP_SHARED; | |
6223 | else | |
6224 | flags = MAP_PRIVATE; | |
6225 | ||
6226 | if (vma->vm_flags & VM_DENYWRITE) | |
6227 | flags |= MAP_DENYWRITE; | |
6228 | if (vma->vm_flags & VM_MAYEXEC) | |
6229 | flags |= MAP_EXECUTABLE; | |
6230 | if (vma->vm_flags & VM_LOCKED) | |
6231 | flags |= MAP_LOCKED; | |
6232 | if (vma->vm_flags & VM_HUGETLB) | |
6233 | flags |= MAP_HUGETLB; | |
6234 | ||
c7e548b4 | 6235 | goto got_name; |
0a4a9391 | 6236 | } else { |
fbe26abe JO |
6237 | if (vma->vm_ops && vma->vm_ops->name) { |
6238 | name = (char *) vma->vm_ops->name(vma); | |
6239 | if (name) | |
6240 | goto cpy_name; | |
6241 | } | |
6242 | ||
2c42cfbf | 6243 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6244 | if (name) |
6245 | goto cpy_name; | |
089dd79d | 6246 | |
32c5fb7e | 6247 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6248 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6249 | name = "[heap]"; |
6250 | goto cpy_name; | |
32c5fb7e ON |
6251 | } |
6252 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6253 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6254 | name = "[stack]"; |
6255 | goto cpy_name; | |
089dd79d PZ |
6256 | } |
6257 | ||
c7e548b4 ON |
6258 | name = "//anon"; |
6259 | goto cpy_name; | |
0a4a9391 PZ |
6260 | } |
6261 | ||
c7e548b4 ON |
6262 | cpy_name: |
6263 | strlcpy(tmp, name, sizeof(tmp)); | |
6264 | name = tmp; | |
0a4a9391 | 6265 | got_name: |
2c42cfbf PZ |
6266 | /* |
6267 | * Since our buffer works in 8 byte units we need to align our string | |
6268 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6269 | * zero'd out to avoid leaking random bits to userspace. | |
6270 | */ | |
6271 | size = strlen(name)+1; | |
6272 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6273 | name[size++] = '\0'; | |
0a4a9391 PZ |
6274 | |
6275 | mmap_event->file_name = name; | |
6276 | mmap_event->file_size = size; | |
13d7a241 SE |
6277 | mmap_event->maj = maj; |
6278 | mmap_event->min = min; | |
6279 | mmap_event->ino = ino; | |
6280 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6281 | mmap_event->prot = prot; |
6282 | mmap_event->flags = flags; | |
0a4a9391 | 6283 | |
2fe85427 SE |
6284 | if (!(vma->vm_flags & VM_EXEC)) |
6285 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6286 | ||
cdd6c482 | 6287 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6288 | |
67516844 | 6289 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6290 | mmap_event, |
6291 | NULL); | |
665c2142 | 6292 | |
0a4a9391 PZ |
6293 | kfree(buf); |
6294 | } | |
6295 | ||
3af9e859 | 6296 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6297 | { |
9ee318a7 PZ |
6298 | struct perf_mmap_event mmap_event; |
6299 | ||
cdd6c482 | 6300 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6301 | return; |
6302 | ||
6303 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6304 | .vma = vma, |
573402db PZ |
6305 | /* .file_name */ |
6306 | /* .file_size */ | |
cdd6c482 | 6307 | .event_id = { |
573402db | 6308 | .header = { |
cdd6c482 | 6309 | .type = PERF_RECORD_MMAP, |
39447b38 | 6310 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6311 | /* .size */ |
6312 | }, | |
6313 | /* .pid */ | |
6314 | /* .tid */ | |
089dd79d PZ |
6315 | .start = vma->vm_start, |
6316 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6317 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6318 | }, |
13d7a241 SE |
6319 | /* .maj (attr_mmap2 only) */ |
6320 | /* .min (attr_mmap2 only) */ | |
6321 | /* .ino (attr_mmap2 only) */ | |
6322 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6323 | /* .prot (attr_mmap2 only) */ |
6324 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6325 | }; |
6326 | ||
cdd6c482 | 6327 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6328 | } |
6329 | ||
68db7e98 AS |
6330 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6331 | unsigned long size, u64 flags) | |
6332 | { | |
6333 | struct perf_output_handle handle; | |
6334 | struct perf_sample_data sample; | |
6335 | struct perf_aux_event { | |
6336 | struct perf_event_header header; | |
6337 | u64 offset; | |
6338 | u64 size; | |
6339 | u64 flags; | |
6340 | } rec = { | |
6341 | .header = { | |
6342 | .type = PERF_RECORD_AUX, | |
6343 | .misc = 0, | |
6344 | .size = sizeof(rec), | |
6345 | }, | |
6346 | .offset = head, | |
6347 | .size = size, | |
6348 | .flags = flags, | |
6349 | }; | |
6350 | int ret; | |
6351 | ||
6352 | perf_event_header__init_id(&rec.header, &sample, event); | |
6353 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6354 | ||
6355 | if (ret) | |
6356 | return; | |
6357 | ||
6358 | perf_output_put(&handle, rec); | |
6359 | perf_event__output_id_sample(event, &handle, &sample); | |
6360 | ||
6361 | perf_output_end(&handle); | |
6362 | } | |
6363 | ||
f38b0dbb KL |
6364 | /* |
6365 | * Lost/dropped samples logging | |
6366 | */ | |
6367 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6368 | { | |
6369 | struct perf_output_handle handle; | |
6370 | struct perf_sample_data sample; | |
6371 | int ret; | |
6372 | ||
6373 | struct { | |
6374 | struct perf_event_header header; | |
6375 | u64 lost; | |
6376 | } lost_samples_event = { | |
6377 | .header = { | |
6378 | .type = PERF_RECORD_LOST_SAMPLES, | |
6379 | .misc = 0, | |
6380 | .size = sizeof(lost_samples_event), | |
6381 | }, | |
6382 | .lost = lost, | |
6383 | }; | |
6384 | ||
6385 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6386 | ||
6387 | ret = perf_output_begin(&handle, event, | |
6388 | lost_samples_event.header.size); | |
6389 | if (ret) | |
6390 | return; | |
6391 | ||
6392 | perf_output_put(&handle, lost_samples_event); | |
6393 | perf_event__output_id_sample(event, &handle, &sample); | |
6394 | perf_output_end(&handle); | |
6395 | } | |
6396 | ||
45ac1403 AH |
6397 | /* |
6398 | * context_switch tracking | |
6399 | */ | |
6400 | ||
6401 | struct perf_switch_event { | |
6402 | struct task_struct *task; | |
6403 | struct task_struct *next_prev; | |
6404 | ||
6405 | struct { | |
6406 | struct perf_event_header header; | |
6407 | u32 next_prev_pid; | |
6408 | u32 next_prev_tid; | |
6409 | } event_id; | |
6410 | }; | |
6411 | ||
6412 | static int perf_event_switch_match(struct perf_event *event) | |
6413 | { | |
6414 | return event->attr.context_switch; | |
6415 | } | |
6416 | ||
6417 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6418 | { | |
6419 | struct perf_switch_event *se = data; | |
6420 | struct perf_output_handle handle; | |
6421 | struct perf_sample_data sample; | |
6422 | int ret; | |
6423 | ||
6424 | if (!perf_event_switch_match(event)) | |
6425 | return; | |
6426 | ||
6427 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6428 | if (event->ctx->task) { | |
6429 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6430 | se->event_id.header.size = sizeof(se->event_id.header); | |
6431 | } else { | |
6432 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6433 | se->event_id.header.size = sizeof(se->event_id); | |
6434 | se->event_id.next_prev_pid = | |
6435 | perf_event_pid(event, se->next_prev); | |
6436 | se->event_id.next_prev_tid = | |
6437 | perf_event_tid(event, se->next_prev); | |
6438 | } | |
6439 | ||
6440 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6441 | ||
6442 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6443 | if (ret) | |
6444 | return; | |
6445 | ||
6446 | if (event->ctx->task) | |
6447 | perf_output_put(&handle, se->event_id.header); | |
6448 | else | |
6449 | perf_output_put(&handle, se->event_id); | |
6450 | ||
6451 | perf_event__output_id_sample(event, &handle, &sample); | |
6452 | ||
6453 | perf_output_end(&handle); | |
6454 | } | |
6455 | ||
6456 | static void perf_event_switch(struct task_struct *task, | |
6457 | struct task_struct *next_prev, bool sched_in) | |
6458 | { | |
6459 | struct perf_switch_event switch_event; | |
6460 | ||
6461 | /* N.B. caller checks nr_switch_events != 0 */ | |
6462 | ||
6463 | switch_event = (struct perf_switch_event){ | |
6464 | .task = task, | |
6465 | .next_prev = next_prev, | |
6466 | .event_id = { | |
6467 | .header = { | |
6468 | /* .type */ | |
6469 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6470 | /* .size */ | |
6471 | }, | |
6472 | /* .next_prev_pid */ | |
6473 | /* .next_prev_tid */ | |
6474 | }, | |
6475 | }; | |
6476 | ||
6477 | perf_event_aux(perf_event_switch_output, | |
6478 | &switch_event, | |
6479 | NULL); | |
6480 | } | |
6481 | ||
a78ac325 PZ |
6482 | /* |
6483 | * IRQ throttle logging | |
6484 | */ | |
6485 | ||
cdd6c482 | 6486 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6487 | { |
6488 | struct perf_output_handle handle; | |
c980d109 | 6489 | struct perf_sample_data sample; |
a78ac325 PZ |
6490 | int ret; |
6491 | ||
6492 | struct { | |
6493 | struct perf_event_header header; | |
6494 | u64 time; | |
cca3f454 | 6495 | u64 id; |
7f453c24 | 6496 | u64 stream_id; |
a78ac325 PZ |
6497 | } throttle_event = { |
6498 | .header = { | |
cdd6c482 | 6499 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6500 | .misc = 0, |
6501 | .size = sizeof(throttle_event), | |
6502 | }, | |
34f43927 | 6503 | .time = perf_event_clock(event), |
cdd6c482 IM |
6504 | .id = primary_event_id(event), |
6505 | .stream_id = event->id, | |
a78ac325 PZ |
6506 | }; |
6507 | ||
966ee4d6 | 6508 | if (enable) |
cdd6c482 | 6509 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6510 | |
c980d109 ACM |
6511 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6512 | ||
6513 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6514 | throttle_event.header.size); |
a78ac325 PZ |
6515 | if (ret) |
6516 | return; | |
6517 | ||
6518 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6519 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6520 | perf_output_end(&handle); |
6521 | } | |
6522 | ||
ec0d7729 AS |
6523 | static void perf_log_itrace_start(struct perf_event *event) |
6524 | { | |
6525 | struct perf_output_handle handle; | |
6526 | struct perf_sample_data sample; | |
6527 | struct perf_aux_event { | |
6528 | struct perf_event_header header; | |
6529 | u32 pid; | |
6530 | u32 tid; | |
6531 | } rec; | |
6532 | int ret; | |
6533 | ||
6534 | if (event->parent) | |
6535 | event = event->parent; | |
6536 | ||
6537 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6538 | event->hw.itrace_started) | |
6539 | return; | |
6540 | ||
ec0d7729 AS |
6541 | rec.header.type = PERF_RECORD_ITRACE_START; |
6542 | rec.header.misc = 0; | |
6543 | rec.header.size = sizeof(rec); | |
6544 | rec.pid = perf_event_pid(event, current); | |
6545 | rec.tid = perf_event_tid(event, current); | |
6546 | ||
6547 | perf_event_header__init_id(&rec.header, &sample, event); | |
6548 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6549 | ||
6550 | if (ret) | |
6551 | return; | |
6552 | ||
6553 | perf_output_put(&handle, rec); | |
6554 | perf_event__output_id_sample(event, &handle, &sample); | |
6555 | ||
6556 | perf_output_end(&handle); | |
6557 | } | |
6558 | ||
f6c7d5fe | 6559 | /* |
cdd6c482 | 6560 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6561 | */ |
6562 | ||
a8b0ca17 | 6563 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6564 | int throttle, struct perf_sample_data *data, |
6565 | struct pt_regs *regs) | |
f6c7d5fe | 6566 | { |
cdd6c482 IM |
6567 | int events = atomic_read(&event->event_limit); |
6568 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6569 | u64 seq; |
79f14641 PZ |
6570 | int ret = 0; |
6571 | ||
96398826 PZ |
6572 | /* |
6573 | * Non-sampling counters might still use the PMI to fold short | |
6574 | * hardware counters, ignore those. | |
6575 | */ | |
6576 | if (unlikely(!is_sampling_event(event))) | |
6577 | return 0; | |
6578 | ||
e050e3f0 SE |
6579 | seq = __this_cpu_read(perf_throttled_seq); |
6580 | if (seq != hwc->interrupts_seq) { | |
6581 | hwc->interrupts_seq = seq; | |
6582 | hwc->interrupts = 1; | |
6583 | } else { | |
6584 | hwc->interrupts++; | |
6585 | if (unlikely(throttle | |
6586 | && hwc->interrupts >= max_samples_per_tick)) { | |
6587 | __this_cpu_inc(perf_throttled_count); | |
555e0c1e | 6588 | tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
163ec435 PZ |
6589 | hwc->interrupts = MAX_INTERRUPTS; |
6590 | perf_log_throttle(event, 0); | |
a78ac325 PZ |
6591 | ret = 1; |
6592 | } | |
e050e3f0 | 6593 | } |
60db5e09 | 6594 | |
cdd6c482 | 6595 | if (event->attr.freq) { |
def0a9b2 | 6596 | u64 now = perf_clock(); |
abd50713 | 6597 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6598 | |
abd50713 | 6599 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6600 | |
abd50713 | 6601 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6602 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6603 | } |
6604 | ||
2023b359 PZ |
6605 | /* |
6606 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6607 | * events |
2023b359 PZ |
6608 | */ |
6609 | ||
cdd6c482 IM |
6610 | event->pending_kill = POLL_IN; |
6611 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6612 | ret = 1; |
cdd6c482 | 6613 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6614 | event->pending_disable = 1; |
6615 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6616 | } |
6617 | ||
453f19ee | 6618 | if (event->overflow_handler) |
a8b0ca17 | 6619 | event->overflow_handler(event, data, regs); |
453f19ee | 6620 | else |
a8b0ca17 | 6621 | perf_event_output(event, data, regs); |
453f19ee | 6622 | |
fed66e2c | 6623 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6624 | event->pending_wakeup = 1; |
6625 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6626 | } |
6627 | ||
79f14641 | 6628 | return ret; |
f6c7d5fe PZ |
6629 | } |
6630 | ||
a8b0ca17 | 6631 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6632 | struct perf_sample_data *data, |
6633 | struct pt_regs *regs) | |
850bc73f | 6634 | { |
a8b0ca17 | 6635 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6636 | } |
6637 | ||
15dbf27c | 6638 | /* |
cdd6c482 | 6639 | * Generic software event infrastructure |
15dbf27c PZ |
6640 | */ |
6641 | ||
b28ab83c PZ |
6642 | struct swevent_htable { |
6643 | struct swevent_hlist *swevent_hlist; | |
6644 | struct mutex hlist_mutex; | |
6645 | int hlist_refcount; | |
6646 | ||
6647 | /* Recursion avoidance in each contexts */ | |
6648 | int recursion[PERF_NR_CONTEXTS]; | |
6649 | }; | |
6650 | ||
6651 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6652 | ||
7b4b6658 | 6653 | /* |
cdd6c482 IM |
6654 | * We directly increment event->count and keep a second value in |
6655 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6656 | * is kept in the range [-sample_period, 0] so that we can use the |
6657 | * sign as trigger. | |
6658 | */ | |
6659 | ||
ab573844 | 6660 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6661 | { |
cdd6c482 | 6662 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6663 | u64 period = hwc->last_period; |
6664 | u64 nr, offset; | |
6665 | s64 old, val; | |
6666 | ||
6667 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6668 | |
6669 | again: | |
e7850595 | 6670 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6671 | if (val < 0) |
6672 | return 0; | |
15dbf27c | 6673 | |
7b4b6658 PZ |
6674 | nr = div64_u64(period + val, period); |
6675 | offset = nr * period; | |
6676 | val -= offset; | |
e7850595 | 6677 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6678 | goto again; |
15dbf27c | 6679 | |
7b4b6658 | 6680 | return nr; |
15dbf27c PZ |
6681 | } |
6682 | ||
0cff784a | 6683 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6684 | struct perf_sample_data *data, |
5622f295 | 6685 | struct pt_regs *regs) |
15dbf27c | 6686 | { |
cdd6c482 | 6687 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6688 | int throttle = 0; |
15dbf27c | 6689 | |
0cff784a PZ |
6690 | if (!overflow) |
6691 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6692 | |
7b4b6658 PZ |
6693 | if (hwc->interrupts == MAX_INTERRUPTS) |
6694 | return; | |
15dbf27c | 6695 | |
7b4b6658 | 6696 | for (; overflow; overflow--) { |
a8b0ca17 | 6697 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6698 | data, regs)) { |
7b4b6658 PZ |
6699 | /* |
6700 | * We inhibit the overflow from happening when | |
6701 | * hwc->interrupts == MAX_INTERRUPTS. | |
6702 | */ | |
6703 | break; | |
6704 | } | |
cf450a73 | 6705 | throttle = 1; |
7b4b6658 | 6706 | } |
15dbf27c PZ |
6707 | } |
6708 | ||
a4eaf7f1 | 6709 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6710 | struct perf_sample_data *data, |
5622f295 | 6711 | struct pt_regs *regs) |
7b4b6658 | 6712 | { |
cdd6c482 | 6713 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6714 | |
e7850595 | 6715 | local64_add(nr, &event->count); |
d6d020e9 | 6716 | |
0cff784a PZ |
6717 | if (!regs) |
6718 | return; | |
6719 | ||
6c7e550f | 6720 | if (!is_sampling_event(event)) |
7b4b6658 | 6721 | return; |
d6d020e9 | 6722 | |
5d81e5cf AV |
6723 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6724 | data->period = nr; | |
6725 | return perf_swevent_overflow(event, 1, data, regs); | |
6726 | } else | |
6727 | data->period = event->hw.last_period; | |
6728 | ||
0cff784a | 6729 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6730 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6731 | |
e7850595 | 6732 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6733 | return; |
df1a132b | 6734 | |
a8b0ca17 | 6735 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6736 | } |
6737 | ||
f5ffe02e FW |
6738 | static int perf_exclude_event(struct perf_event *event, |
6739 | struct pt_regs *regs) | |
6740 | { | |
a4eaf7f1 | 6741 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6742 | return 1; |
a4eaf7f1 | 6743 | |
f5ffe02e FW |
6744 | if (regs) { |
6745 | if (event->attr.exclude_user && user_mode(regs)) | |
6746 | return 1; | |
6747 | ||
6748 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6749 | return 1; | |
6750 | } | |
6751 | ||
6752 | return 0; | |
6753 | } | |
6754 | ||
cdd6c482 | 6755 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6756 | enum perf_type_id type, |
6fb2915d LZ |
6757 | u32 event_id, |
6758 | struct perf_sample_data *data, | |
6759 | struct pt_regs *regs) | |
15dbf27c | 6760 | { |
cdd6c482 | 6761 | if (event->attr.type != type) |
a21ca2ca | 6762 | return 0; |
f5ffe02e | 6763 | |
cdd6c482 | 6764 | if (event->attr.config != event_id) |
15dbf27c PZ |
6765 | return 0; |
6766 | ||
f5ffe02e FW |
6767 | if (perf_exclude_event(event, regs)) |
6768 | return 0; | |
15dbf27c PZ |
6769 | |
6770 | return 1; | |
6771 | } | |
6772 | ||
76e1d904 FW |
6773 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6774 | { | |
6775 | u64 val = event_id | (type << 32); | |
6776 | ||
6777 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6778 | } | |
6779 | ||
49f135ed FW |
6780 | static inline struct hlist_head * |
6781 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6782 | { |
49f135ed FW |
6783 | u64 hash = swevent_hash(type, event_id); |
6784 | ||
6785 | return &hlist->heads[hash]; | |
6786 | } | |
76e1d904 | 6787 | |
49f135ed FW |
6788 | /* For the read side: events when they trigger */ |
6789 | static inline struct hlist_head * | |
b28ab83c | 6790 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6791 | { |
6792 | struct swevent_hlist *hlist; | |
76e1d904 | 6793 | |
b28ab83c | 6794 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6795 | if (!hlist) |
6796 | return NULL; | |
6797 | ||
49f135ed FW |
6798 | return __find_swevent_head(hlist, type, event_id); |
6799 | } | |
6800 | ||
6801 | /* For the event head insertion and removal in the hlist */ | |
6802 | static inline struct hlist_head * | |
b28ab83c | 6803 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6804 | { |
6805 | struct swevent_hlist *hlist; | |
6806 | u32 event_id = event->attr.config; | |
6807 | u64 type = event->attr.type; | |
6808 | ||
6809 | /* | |
6810 | * Event scheduling is always serialized against hlist allocation | |
6811 | * and release. Which makes the protected version suitable here. | |
6812 | * The context lock guarantees that. | |
6813 | */ | |
b28ab83c | 6814 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6815 | lockdep_is_held(&event->ctx->lock)); |
6816 | if (!hlist) | |
6817 | return NULL; | |
6818 | ||
6819 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6820 | } |
6821 | ||
6822 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6823 | u64 nr, |
76e1d904 FW |
6824 | struct perf_sample_data *data, |
6825 | struct pt_regs *regs) | |
15dbf27c | 6826 | { |
4a32fea9 | 6827 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6828 | struct perf_event *event; |
76e1d904 | 6829 | struct hlist_head *head; |
15dbf27c | 6830 | |
76e1d904 | 6831 | rcu_read_lock(); |
b28ab83c | 6832 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6833 | if (!head) |
6834 | goto end; | |
6835 | ||
b67bfe0d | 6836 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6837 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6838 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6839 | } |
76e1d904 FW |
6840 | end: |
6841 | rcu_read_unlock(); | |
15dbf27c PZ |
6842 | } |
6843 | ||
86038c5e PZI |
6844 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6845 | ||
4ed7c92d | 6846 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6847 | { |
4a32fea9 | 6848 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6849 | |
b28ab83c | 6850 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6851 | } |
645e8cc0 | 6852 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6853 | |
fa9f90be | 6854 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6855 | { |
4a32fea9 | 6856 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6857 | |
b28ab83c | 6858 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6859 | } |
15dbf27c | 6860 | |
86038c5e | 6861 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6862 | { |
a4234bfc | 6863 | struct perf_sample_data data; |
4ed7c92d | 6864 | |
86038c5e | 6865 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6866 | return; |
a4234bfc | 6867 | |
fd0d000b | 6868 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6869 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6870 | } |
6871 | ||
6872 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6873 | { | |
6874 | int rctx; | |
6875 | ||
6876 | preempt_disable_notrace(); | |
6877 | rctx = perf_swevent_get_recursion_context(); | |
6878 | if (unlikely(rctx < 0)) | |
6879 | goto fail; | |
6880 | ||
6881 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6882 | |
6883 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6884 | fail: |
1c024eca | 6885 | preempt_enable_notrace(); |
b8e83514 PZ |
6886 | } |
6887 | ||
cdd6c482 | 6888 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6889 | { |
15dbf27c PZ |
6890 | } |
6891 | ||
a4eaf7f1 | 6892 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6893 | { |
4a32fea9 | 6894 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6895 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6896 | struct hlist_head *head; |
6897 | ||
6c7e550f | 6898 | if (is_sampling_event(event)) { |
7b4b6658 | 6899 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6900 | perf_swevent_set_period(event); |
7b4b6658 | 6901 | } |
76e1d904 | 6902 | |
a4eaf7f1 PZ |
6903 | hwc->state = !(flags & PERF_EF_START); |
6904 | ||
b28ab83c | 6905 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6906 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6907 | return -EINVAL; |
6908 | ||
6909 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6910 | perf_event_update_userpage(event); |
76e1d904 | 6911 | |
15dbf27c PZ |
6912 | return 0; |
6913 | } | |
6914 | ||
a4eaf7f1 | 6915 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6916 | { |
76e1d904 | 6917 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6918 | } |
6919 | ||
a4eaf7f1 | 6920 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6921 | { |
a4eaf7f1 | 6922 | event->hw.state = 0; |
d6d020e9 | 6923 | } |
aa9c4c0f | 6924 | |
a4eaf7f1 | 6925 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6926 | { |
a4eaf7f1 | 6927 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6928 | } |
6929 | ||
49f135ed FW |
6930 | /* Deref the hlist from the update side */ |
6931 | static inline struct swevent_hlist * | |
b28ab83c | 6932 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6933 | { |
b28ab83c PZ |
6934 | return rcu_dereference_protected(swhash->swevent_hlist, |
6935 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6936 | } |
6937 | ||
b28ab83c | 6938 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6939 | { |
b28ab83c | 6940 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6941 | |
49f135ed | 6942 | if (!hlist) |
76e1d904 FW |
6943 | return; |
6944 | ||
70691d4a | 6945 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6946 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6947 | } |
6948 | ||
3b364d7b | 6949 | static void swevent_hlist_put_cpu(int cpu) |
76e1d904 | 6950 | { |
b28ab83c | 6951 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6952 | |
b28ab83c | 6953 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6954 | |
b28ab83c PZ |
6955 | if (!--swhash->hlist_refcount) |
6956 | swevent_hlist_release(swhash); | |
76e1d904 | 6957 | |
b28ab83c | 6958 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6959 | } |
6960 | ||
3b364d7b | 6961 | static void swevent_hlist_put(void) |
76e1d904 FW |
6962 | { |
6963 | int cpu; | |
6964 | ||
76e1d904 | 6965 | for_each_possible_cpu(cpu) |
3b364d7b | 6966 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
6967 | } |
6968 | ||
3b364d7b | 6969 | static int swevent_hlist_get_cpu(int cpu) |
76e1d904 | 6970 | { |
b28ab83c | 6971 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6972 | int err = 0; |
6973 | ||
b28ab83c | 6974 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6975 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6976 | struct swevent_hlist *hlist; |
6977 | ||
6978 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6979 | if (!hlist) { | |
6980 | err = -ENOMEM; | |
6981 | goto exit; | |
6982 | } | |
b28ab83c | 6983 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6984 | } |
b28ab83c | 6985 | swhash->hlist_refcount++; |
9ed6060d | 6986 | exit: |
b28ab83c | 6987 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6988 | |
6989 | return err; | |
6990 | } | |
6991 | ||
3b364d7b | 6992 | static int swevent_hlist_get(void) |
76e1d904 | 6993 | { |
3b364d7b | 6994 | int err, cpu, failed_cpu; |
76e1d904 | 6995 | |
76e1d904 FW |
6996 | get_online_cpus(); |
6997 | for_each_possible_cpu(cpu) { | |
3b364d7b | 6998 | err = swevent_hlist_get_cpu(cpu); |
76e1d904 FW |
6999 | if (err) { |
7000 | failed_cpu = cpu; | |
7001 | goto fail; | |
7002 | } | |
7003 | } | |
7004 | put_online_cpus(); | |
7005 | ||
7006 | return 0; | |
9ed6060d | 7007 | fail: |
76e1d904 FW |
7008 | for_each_possible_cpu(cpu) { |
7009 | if (cpu == failed_cpu) | |
7010 | break; | |
3b364d7b | 7011 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
7012 | } |
7013 | ||
7014 | put_online_cpus(); | |
7015 | return err; | |
7016 | } | |
7017 | ||
c5905afb | 7018 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 7019 | |
b0a873eb PZ |
7020 | static void sw_perf_event_destroy(struct perf_event *event) |
7021 | { | |
7022 | u64 event_id = event->attr.config; | |
95476b64 | 7023 | |
b0a873eb PZ |
7024 | WARN_ON(event->parent); |
7025 | ||
c5905afb | 7026 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
3b364d7b | 7027 | swevent_hlist_put(); |
b0a873eb PZ |
7028 | } |
7029 | ||
7030 | static int perf_swevent_init(struct perf_event *event) | |
7031 | { | |
8176cced | 7032 | u64 event_id = event->attr.config; |
b0a873eb PZ |
7033 | |
7034 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7035 | return -ENOENT; | |
7036 | ||
2481c5fa SE |
7037 | /* |
7038 | * no branch sampling for software events | |
7039 | */ | |
7040 | if (has_branch_stack(event)) | |
7041 | return -EOPNOTSUPP; | |
7042 | ||
b0a873eb PZ |
7043 | switch (event_id) { |
7044 | case PERF_COUNT_SW_CPU_CLOCK: | |
7045 | case PERF_COUNT_SW_TASK_CLOCK: | |
7046 | return -ENOENT; | |
7047 | ||
7048 | default: | |
7049 | break; | |
7050 | } | |
7051 | ||
ce677831 | 7052 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
7053 | return -ENOENT; |
7054 | ||
7055 | if (!event->parent) { | |
7056 | int err; | |
7057 | ||
3b364d7b | 7058 | err = swevent_hlist_get(); |
b0a873eb PZ |
7059 | if (err) |
7060 | return err; | |
7061 | ||
c5905afb | 7062 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
7063 | event->destroy = sw_perf_event_destroy; |
7064 | } | |
7065 | ||
7066 | return 0; | |
7067 | } | |
7068 | ||
7069 | static struct pmu perf_swevent = { | |
89a1e187 | 7070 | .task_ctx_nr = perf_sw_context, |
95476b64 | 7071 | |
34f43927 PZ |
7072 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7073 | ||
b0a873eb | 7074 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
7075 | .add = perf_swevent_add, |
7076 | .del = perf_swevent_del, | |
7077 | .start = perf_swevent_start, | |
7078 | .stop = perf_swevent_stop, | |
1c024eca | 7079 | .read = perf_swevent_read, |
1c024eca PZ |
7080 | }; |
7081 | ||
b0a873eb PZ |
7082 | #ifdef CONFIG_EVENT_TRACING |
7083 | ||
1c024eca PZ |
7084 | static int perf_tp_filter_match(struct perf_event *event, |
7085 | struct perf_sample_data *data) | |
7086 | { | |
7087 | void *record = data->raw->data; | |
7088 | ||
b71b437e PZ |
7089 | /* only top level events have filters set */ |
7090 | if (event->parent) | |
7091 | event = event->parent; | |
7092 | ||
1c024eca PZ |
7093 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
7094 | return 1; | |
7095 | return 0; | |
7096 | } | |
7097 | ||
7098 | static int perf_tp_event_match(struct perf_event *event, | |
7099 | struct perf_sample_data *data, | |
7100 | struct pt_regs *regs) | |
7101 | { | |
a0f7d0f7 FW |
7102 | if (event->hw.state & PERF_HES_STOPPED) |
7103 | return 0; | |
580d607c PZ |
7104 | /* |
7105 | * All tracepoints are from kernel-space. | |
7106 | */ | |
7107 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
7108 | return 0; |
7109 | ||
7110 | if (!perf_tp_filter_match(event, data)) | |
7111 | return 0; | |
7112 | ||
7113 | return 1; | |
7114 | } | |
7115 | ||
7116 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
7117 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
7118 | struct task_struct *task) | |
95476b64 FW |
7119 | { |
7120 | struct perf_sample_data data; | |
1c024eca | 7121 | struct perf_event *event; |
1c024eca | 7122 | |
95476b64 FW |
7123 | struct perf_raw_record raw = { |
7124 | .size = entry_size, | |
7125 | .data = record, | |
7126 | }; | |
7127 | ||
fd0d000b | 7128 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
7129 | data.raw = &raw; |
7130 | ||
b67bfe0d | 7131 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 7132 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 7133 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 7134 | } |
ecc55f84 | 7135 | |
e6dab5ff AV |
7136 | /* |
7137 | * If we got specified a target task, also iterate its context and | |
7138 | * deliver this event there too. | |
7139 | */ | |
7140 | if (task && task != current) { | |
7141 | struct perf_event_context *ctx; | |
7142 | struct trace_entry *entry = record; | |
7143 | ||
7144 | rcu_read_lock(); | |
7145 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
7146 | if (!ctx) | |
7147 | goto unlock; | |
7148 | ||
7149 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
7150 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7151 | continue; | |
7152 | if (event->attr.config != entry->type) | |
7153 | continue; | |
7154 | if (perf_tp_event_match(event, &data, regs)) | |
7155 | perf_swevent_event(event, count, &data, regs); | |
7156 | } | |
7157 | unlock: | |
7158 | rcu_read_unlock(); | |
7159 | } | |
7160 | ||
ecc55f84 | 7161 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
7162 | } |
7163 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
7164 | ||
cdd6c482 | 7165 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 7166 | { |
1c024eca | 7167 | perf_trace_destroy(event); |
e077df4f PZ |
7168 | } |
7169 | ||
b0a873eb | 7170 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 7171 | { |
76e1d904 FW |
7172 | int err; |
7173 | ||
b0a873eb PZ |
7174 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
7175 | return -ENOENT; | |
7176 | ||
2481c5fa SE |
7177 | /* |
7178 | * no branch sampling for tracepoint events | |
7179 | */ | |
7180 | if (has_branch_stack(event)) | |
7181 | return -EOPNOTSUPP; | |
7182 | ||
1c024eca PZ |
7183 | err = perf_trace_init(event); |
7184 | if (err) | |
b0a873eb | 7185 | return err; |
e077df4f | 7186 | |
cdd6c482 | 7187 | event->destroy = tp_perf_event_destroy; |
e077df4f | 7188 | |
b0a873eb PZ |
7189 | return 0; |
7190 | } | |
7191 | ||
7192 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
7193 | .task_ctx_nr = perf_sw_context, |
7194 | ||
b0a873eb | 7195 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
7196 | .add = perf_trace_add, |
7197 | .del = perf_trace_del, | |
7198 | .start = perf_swevent_start, | |
7199 | .stop = perf_swevent_stop, | |
b0a873eb | 7200 | .read = perf_swevent_read, |
b0a873eb PZ |
7201 | }; |
7202 | ||
7203 | static inline void perf_tp_register(void) | |
7204 | { | |
2e80a82a | 7205 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 7206 | } |
6fb2915d LZ |
7207 | |
7208 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7209 | { | |
7210 | char *filter_str; | |
7211 | int ret; | |
7212 | ||
7213 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7214 | return -EINVAL; | |
7215 | ||
7216 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7217 | if (IS_ERR(filter_str)) | |
7218 | return PTR_ERR(filter_str); | |
7219 | ||
7220 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
7221 | ||
7222 | kfree(filter_str); | |
7223 | return ret; | |
7224 | } | |
7225 | ||
7226 | static void perf_event_free_filter(struct perf_event *event) | |
7227 | { | |
7228 | ftrace_profile_free_filter(event); | |
7229 | } | |
7230 | ||
2541517c AS |
7231 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7232 | { | |
7233 | struct bpf_prog *prog; | |
7234 | ||
7235 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7236 | return -EINVAL; | |
7237 | ||
7238 | if (event->tp_event->prog) | |
7239 | return -EEXIST; | |
7240 | ||
04a22fae WN |
7241 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7242 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7243 | return -EINVAL; |
7244 | ||
7245 | prog = bpf_prog_get(prog_fd); | |
7246 | if (IS_ERR(prog)) | |
7247 | return PTR_ERR(prog); | |
7248 | ||
6c373ca8 | 7249 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7250 | /* valid fd, but invalid bpf program type */ |
7251 | bpf_prog_put(prog); | |
7252 | return -EINVAL; | |
7253 | } | |
7254 | ||
7255 | event->tp_event->prog = prog; | |
7256 | ||
7257 | return 0; | |
7258 | } | |
7259 | ||
7260 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7261 | { | |
7262 | struct bpf_prog *prog; | |
7263 | ||
7264 | if (!event->tp_event) | |
7265 | return; | |
7266 | ||
7267 | prog = event->tp_event->prog; | |
7268 | if (prog) { | |
7269 | event->tp_event->prog = NULL; | |
7270 | bpf_prog_put(prog); | |
7271 | } | |
7272 | } | |
7273 | ||
e077df4f | 7274 | #else |
6fb2915d | 7275 | |
b0a873eb | 7276 | static inline void perf_tp_register(void) |
e077df4f | 7277 | { |
e077df4f | 7278 | } |
6fb2915d LZ |
7279 | |
7280 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7281 | { | |
7282 | return -ENOENT; | |
7283 | } | |
7284 | ||
7285 | static void perf_event_free_filter(struct perf_event *event) | |
7286 | { | |
7287 | } | |
7288 | ||
2541517c AS |
7289 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7290 | { | |
7291 | return -ENOENT; | |
7292 | } | |
7293 | ||
7294 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7295 | { | |
7296 | } | |
07b139c8 | 7297 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7298 | |
24f1e32c | 7299 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7300 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7301 | { |
f5ffe02e FW |
7302 | struct perf_sample_data sample; |
7303 | struct pt_regs *regs = data; | |
7304 | ||
fd0d000b | 7305 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7306 | |
a4eaf7f1 | 7307 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7308 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7309 | } |
7310 | #endif | |
7311 | ||
b0a873eb PZ |
7312 | /* |
7313 | * hrtimer based swevent callback | |
7314 | */ | |
f29ac756 | 7315 | |
b0a873eb | 7316 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7317 | { |
b0a873eb PZ |
7318 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7319 | struct perf_sample_data data; | |
7320 | struct pt_regs *regs; | |
7321 | struct perf_event *event; | |
7322 | u64 period; | |
f29ac756 | 7323 | |
b0a873eb | 7324 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7325 | |
7326 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7327 | return HRTIMER_NORESTART; | |
7328 | ||
b0a873eb | 7329 | event->pmu->read(event); |
f344011c | 7330 | |
fd0d000b | 7331 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7332 | regs = get_irq_regs(); |
7333 | ||
7334 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7335 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7336 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7337 | ret = HRTIMER_NORESTART; |
7338 | } | |
24f1e32c | 7339 | |
b0a873eb PZ |
7340 | period = max_t(u64, 10000, event->hw.sample_period); |
7341 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7342 | |
b0a873eb | 7343 | return ret; |
f29ac756 PZ |
7344 | } |
7345 | ||
b0a873eb | 7346 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7347 | { |
b0a873eb | 7348 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7349 | s64 period; |
7350 | ||
7351 | if (!is_sampling_event(event)) | |
7352 | return; | |
f5ffe02e | 7353 | |
5d508e82 FBH |
7354 | period = local64_read(&hwc->period_left); |
7355 | if (period) { | |
7356 | if (period < 0) | |
7357 | period = 10000; | |
fa407f35 | 7358 | |
5d508e82 FBH |
7359 | local64_set(&hwc->period_left, 0); |
7360 | } else { | |
7361 | period = max_t(u64, 10000, hwc->sample_period); | |
7362 | } | |
3497d206 TG |
7363 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7364 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7365 | } |
b0a873eb PZ |
7366 | |
7367 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7368 | { |
b0a873eb PZ |
7369 | struct hw_perf_event *hwc = &event->hw; |
7370 | ||
6c7e550f | 7371 | if (is_sampling_event(event)) { |
b0a873eb | 7372 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7373 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7374 | |
7375 | hrtimer_cancel(&hwc->hrtimer); | |
7376 | } | |
24f1e32c FW |
7377 | } |
7378 | ||
ba3dd36c PZ |
7379 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7380 | { | |
7381 | struct hw_perf_event *hwc = &event->hw; | |
7382 | ||
7383 | if (!is_sampling_event(event)) | |
7384 | return; | |
7385 | ||
7386 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7387 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7388 | ||
7389 | /* | |
7390 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7391 | * mapping and avoid the whole period adjust feedback stuff. | |
7392 | */ | |
7393 | if (event->attr.freq) { | |
7394 | long freq = event->attr.sample_freq; | |
7395 | ||
7396 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7397 | hwc->sample_period = event->attr.sample_period; | |
7398 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7399 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7400 | event->attr.freq = 0; |
7401 | } | |
7402 | } | |
7403 | ||
b0a873eb PZ |
7404 | /* |
7405 | * Software event: cpu wall time clock | |
7406 | */ | |
7407 | ||
7408 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7409 | { |
b0a873eb PZ |
7410 | s64 prev; |
7411 | u64 now; | |
7412 | ||
a4eaf7f1 | 7413 | now = local_clock(); |
b0a873eb PZ |
7414 | prev = local64_xchg(&event->hw.prev_count, now); |
7415 | local64_add(now - prev, &event->count); | |
24f1e32c | 7416 | } |
24f1e32c | 7417 | |
a4eaf7f1 | 7418 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7419 | { |
a4eaf7f1 | 7420 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7421 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7422 | } |
7423 | ||
a4eaf7f1 | 7424 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7425 | { |
b0a873eb PZ |
7426 | perf_swevent_cancel_hrtimer(event); |
7427 | cpu_clock_event_update(event); | |
7428 | } | |
f29ac756 | 7429 | |
a4eaf7f1 PZ |
7430 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7431 | { | |
7432 | if (flags & PERF_EF_START) | |
7433 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7434 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7435 | |
7436 | return 0; | |
7437 | } | |
7438 | ||
7439 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7440 | { | |
7441 | cpu_clock_event_stop(event, flags); | |
7442 | } | |
7443 | ||
b0a873eb PZ |
7444 | static void cpu_clock_event_read(struct perf_event *event) |
7445 | { | |
7446 | cpu_clock_event_update(event); | |
7447 | } | |
f344011c | 7448 | |
b0a873eb PZ |
7449 | static int cpu_clock_event_init(struct perf_event *event) |
7450 | { | |
7451 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7452 | return -ENOENT; | |
7453 | ||
7454 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7455 | return -ENOENT; | |
7456 | ||
2481c5fa SE |
7457 | /* |
7458 | * no branch sampling for software events | |
7459 | */ | |
7460 | if (has_branch_stack(event)) | |
7461 | return -EOPNOTSUPP; | |
7462 | ||
ba3dd36c PZ |
7463 | perf_swevent_init_hrtimer(event); |
7464 | ||
b0a873eb | 7465 | return 0; |
f29ac756 PZ |
7466 | } |
7467 | ||
b0a873eb | 7468 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7469 | .task_ctx_nr = perf_sw_context, |
7470 | ||
34f43927 PZ |
7471 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7472 | ||
b0a873eb | 7473 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7474 | .add = cpu_clock_event_add, |
7475 | .del = cpu_clock_event_del, | |
7476 | .start = cpu_clock_event_start, | |
7477 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7478 | .read = cpu_clock_event_read, |
7479 | }; | |
7480 | ||
7481 | /* | |
7482 | * Software event: task time clock | |
7483 | */ | |
7484 | ||
7485 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7486 | { |
b0a873eb PZ |
7487 | u64 prev; |
7488 | s64 delta; | |
5c92d124 | 7489 | |
b0a873eb PZ |
7490 | prev = local64_xchg(&event->hw.prev_count, now); |
7491 | delta = now - prev; | |
7492 | local64_add(delta, &event->count); | |
7493 | } | |
5c92d124 | 7494 | |
a4eaf7f1 | 7495 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7496 | { |
a4eaf7f1 | 7497 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7498 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7499 | } |
7500 | ||
a4eaf7f1 | 7501 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7502 | { |
7503 | perf_swevent_cancel_hrtimer(event); | |
7504 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7505 | } |
7506 | ||
7507 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7508 | { | |
7509 | if (flags & PERF_EF_START) | |
7510 | task_clock_event_start(event, flags); | |
6a694a60 | 7511 | perf_event_update_userpage(event); |
b0a873eb | 7512 | |
a4eaf7f1 PZ |
7513 | return 0; |
7514 | } | |
7515 | ||
7516 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7517 | { | |
7518 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7519 | } |
7520 | ||
7521 | static void task_clock_event_read(struct perf_event *event) | |
7522 | { | |
768a06e2 PZ |
7523 | u64 now = perf_clock(); |
7524 | u64 delta = now - event->ctx->timestamp; | |
7525 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7526 | |
7527 | task_clock_event_update(event, time); | |
7528 | } | |
7529 | ||
7530 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7531 | { |
b0a873eb PZ |
7532 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7533 | return -ENOENT; | |
7534 | ||
7535 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7536 | return -ENOENT; | |
7537 | ||
2481c5fa SE |
7538 | /* |
7539 | * no branch sampling for software events | |
7540 | */ | |
7541 | if (has_branch_stack(event)) | |
7542 | return -EOPNOTSUPP; | |
7543 | ||
ba3dd36c PZ |
7544 | perf_swevent_init_hrtimer(event); |
7545 | ||
b0a873eb | 7546 | return 0; |
6fb2915d LZ |
7547 | } |
7548 | ||
b0a873eb | 7549 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7550 | .task_ctx_nr = perf_sw_context, |
7551 | ||
34f43927 PZ |
7552 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7553 | ||
b0a873eb | 7554 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7555 | .add = task_clock_event_add, |
7556 | .del = task_clock_event_del, | |
7557 | .start = task_clock_event_start, | |
7558 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7559 | .read = task_clock_event_read, |
7560 | }; | |
6fb2915d | 7561 | |
ad5133b7 | 7562 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7563 | { |
e077df4f | 7564 | } |
6fb2915d | 7565 | |
fbbe0701 SB |
7566 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7567 | { | |
7568 | } | |
7569 | ||
ad5133b7 | 7570 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7571 | { |
ad5133b7 | 7572 | return 0; |
6fb2915d LZ |
7573 | } |
7574 | ||
18ab2cd3 | 7575 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7576 | |
7577 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7578 | { |
fbbe0701 SB |
7579 | __this_cpu_write(nop_txn_flags, flags); |
7580 | ||
7581 | if (flags & ~PERF_PMU_TXN_ADD) | |
7582 | return; | |
7583 | ||
ad5133b7 | 7584 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7585 | } |
7586 | ||
ad5133b7 PZ |
7587 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7588 | { | |
fbbe0701 SB |
7589 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7590 | ||
7591 | __this_cpu_write(nop_txn_flags, 0); | |
7592 | ||
7593 | if (flags & ~PERF_PMU_TXN_ADD) | |
7594 | return 0; | |
7595 | ||
ad5133b7 PZ |
7596 | perf_pmu_enable(pmu); |
7597 | return 0; | |
7598 | } | |
e077df4f | 7599 | |
ad5133b7 | 7600 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7601 | { |
fbbe0701 SB |
7602 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7603 | ||
7604 | __this_cpu_write(nop_txn_flags, 0); | |
7605 | ||
7606 | if (flags & ~PERF_PMU_TXN_ADD) | |
7607 | return; | |
7608 | ||
ad5133b7 | 7609 | perf_pmu_enable(pmu); |
24f1e32c FW |
7610 | } |
7611 | ||
35edc2a5 PZ |
7612 | static int perf_event_idx_default(struct perf_event *event) |
7613 | { | |
c719f560 | 7614 | return 0; |
35edc2a5 PZ |
7615 | } |
7616 | ||
8dc85d54 PZ |
7617 | /* |
7618 | * Ensures all contexts with the same task_ctx_nr have the same | |
7619 | * pmu_cpu_context too. | |
7620 | */ | |
9e317041 | 7621 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7622 | { |
8dc85d54 | 7623 | struct pmu *pmu; |
b326e956 | 7624 | |
8dc85d54 PZ |
7625 | if (ctxn < 0) |
7626 | return NULL; | |
24f1e32c | 7627 | |
8dc85d54 PZ |
7628 | list_for_each_entry(pmu, &pmus, entry) { |
7629 | if (pmu->task_ctx_nr == ctxn) | |
7630 | return pmu->pmu_cpu_context; | |
7631 | } | |
24f1e32c | 7632 | |
8dc85d54 | 7633 | return NULL; |
24f1e32c FW |
7634 | } |
7635 | ||
51676957 | 7636 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7637 | { |
51676957 PZ |
7638 | int cpu; |
7639 | ||
7640 | for_each_possible_cpu(cpu) { | |
7641 | struct perf_cpu_context *cpuctx; | |
7642 | ||
7643 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7644 | ||
3f1f3320 PZ |
7645 | if (cpuctx->unique_pmu == old_pmu) |
7646 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7647 | } |
7648 | } | |
7649 | ||
7650 | static void free_pmu_context(struct pmu *pmu) | |
7651 | { | |
7652 | struct pmu *i; | |
f5ffe02e | 7653 | |
8dc85d54 | 7654 | mutex_lock(&pmus_lock); |
0475f9ea | 7655 | /* |
8dc85d54 | 7656 | * Like a real lame refcount. |
0475f9ea | 7657 | */ |
51676957 PZ |
7658 | list_for_each_entry(i, &pmus, entry) { |
7659 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7660 | update_pmu_context(i, pmu); | |
8dc85d54 | 7661 | goto out; |
51676957 | 7662 | } |
8dc85d54 | 7663 | } |
d6d020e9 | 7664 | |
51676957 | 7665 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7666 | out: |
7667 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7668 | } |
2e80a82a | 7669 | static struct idr pmu_idr; |
d6d020e9 | 7670 | |
abe43400 PZ |
7671 | static ssize_t |
7672 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7673 | { | |
7674 | struct pmu *pmu = dev_get_drvdata(dev); | |
7675 | ||
7676 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7677 | } | |
90826ca7 | 7678 | static DEVICE_ATTR_RO(type); |
abe43400 | 7679 | |
62b85639 SE |
7680 | static ssize_t |
7681 | perf_event_mux_interval_ms_show(struct device *dev, | |
7682 | struct device_attribute *attr, | |
7683 | char *page) | |
7684 | { | |
7685 | struct pmu *pmu = dev_get_drvdata(dev); | |
7686 | ||
7687 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7688 | } | |
7689 | ||
272325c4 PZ |
7690 | static DEFINE_MUTEX(mux_interval_mutex); |
7691 | ||
62b85639 SE |
7692 | static ssize_t |
7693 | perf_event_mux_interval_ms_store(struct device *dev, | |
7694 | struct device_attribute *attr, | |
7695 | const char *buf, size_t count) | |
7696 | { | |
7697 | struct pmu *pmu = dev_get_drvdata(dev); | |
7698 | int timer, cpu, ret; | |
7699 | ||
7700 | ret = kstrtoint(buf, 0, &timer); | |
7701 | if (ret) | |
7702 | return ret; | |
7703 | ||
7704 | if (timer < 1) | |
7705 | return -EINVAL; | |
7706 | ||
7707 | /* same value, noting to do */ | |
7708 | if (timer == pmu->hrtimer_interval_ms) | |
7709 | return count; | |
7710 | ||
272325c4 | 7711 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7712 | pmu->hrtimer_interval_ms = timer; |
7713 | ||
7714 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7715 | get_online_cpus(); |
7716 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7717 | struct perf_cpu_context *cpuctx; |
7718 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7719 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7720 | ||
272325c4 PZ |
7721 | cpu_function_call(cpu, |
7722 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7723 | } |
272325c4 PZ |
7724 | put_online_cpus(); |
7725 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7726 | |
7727 | return count; | |
7728 | } | |
90826ca7 | 7729 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7730 | |
90826ca7 GKH |
7731 | static struct attribute *pmu_dev_attrs[] = { |
7732 | &dev_attr_type.attr, | |
7733 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7734 | NULL, | |
abe43400 | 7735 | }; |
90826ca7 | 7736 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7737 | |
7738 | static int pmu_bus_running; | |
7739 | static struct bus_type pmu_bus = { | |
7740 | .name = "event_source", | |
90826ca7 | 7741 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7742 | }; |
7743 | ||
7744 | static void pmu_dev_release(struct device *dev) | |
7745 | { | |
7746 | kfree(dev); | |
7747 | } | |
7748 | ||
7749 | static int pmu_dev_alloc(struct pmu *pmu) | |
7750 | { | |
7751 | int ret = -ENOMEM; | |
7752 | ||
7753 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7754 | if (!pmu->dev) | |
7755 | goto out; | |
7756 | ||
0c9d42ed | 7757 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7758 | device_initialize(pmu->dev); |
7759 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7760 | if (ret) | |
7761 | goto free_dev; | |
7762 | ||
7763 | dev_set_drvdata(pmu->dev, pmu); | |
7764 | pmu->dev->bus = &pmu_bus; | |
7765 | pmu->dev->release = pmu_dev_release; | |
7766 | ret = device_add(pmu->dev); | |
7767 | if (ret) | |
7768 | goto free_dev; | |
7769 | ||
7770 | out: | |
7771 | return ret; | |
7772 | ||
7773 | free_dev: | |
7774 | put_device(pmu->dev); | |
7775 | goto out; | |
7776 | } | |
7777 | ||
547e9fd7 | 7778 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7779 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7780 | |
03d8e80b | 7781 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7782 | { |
108b02cf | 7783 | int cpu, ret; |
24f1e32c | 7784 | |
b0a873eb | 7785 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7786 | ret = -ENOMEM; |
7787 | pmu->pmu_disable_count = alloc_percpu(int); | |
7788 | if (!pmu->pmu_disable_count) | |
7789 | goto unlock; | |
f29ac756 | 7790 | |
2e80a82a PZ |
7791 | pmu->type = -1; |
7792 | if (!name) | |
7793 | goto skip_type; | |
7794 | pmu->name = name; | |
7795 | ||
7796 | if (type < 0) { | |
0e9c3be2 TH |
7797 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7798 | if (type < 0) { | |
7799 | ret = type; | |
2e80a82a PZ |
7800 | goto free_pdc; |
7801 | } | |
7802 | } | |
7803 | pmu->type = type; | |
7804 | ||
abe43400 PZ |
7805 | if (pmu_bus_running) { |
7806 | ret = pmu_dev_alloc(pmu); | |
7807 | if (ret) | |
7808 | goto free_idr; | |
7809 | } | |
7810 | ||
2e80a82a | 7811 | skip_type: |
26657848 PZ |
7812 | if (pmu->task_ctx_nr == perf_hw_context) { |
7813 | static int hw_context_taken = 0; | |
7814 | ||
7815 | if (WARN_ON_ONCE(hw_context_taken)) | |
7816 | pmu->task_ctx_nr = perf_invalid_context; | |
7817 | ||
7818 | hw_context_taken = 1; | |
7819 | } | |
7820 | ||
8dc85d54 PZ |
7821 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7822 | if (pmu->pmu_cpu_context) | |
7823 | goto got_cpu_context; | |
f29ac756 | 7824 | |
c4814202 | 7825 | ret = -ENOMEM; |
108b02cf PZ |
7826 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7827 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7828 | goto free_dev; |
f344011c | 7829 | |
108b02cf PZ |
7830 | for_each_possible_cpu(cpu) { |
7831 | struct perf_cpu_context *cpuctx; | |
7832 | ||
7833 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7834 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7835 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7836 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7837 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7838 | |
272325c4 | 7839 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7840 | |
3f1f3320 | 7841 | cpuctx->unique_pmu = pmu; |
108b02cf | 7842 | } |
76e1d904 | 7843 | |
8dc85d54 | 7844 | got_cpu_context: |
ad5133b7 PZ |
7845 | if (!pmu->start_txn) { |
7846 | if (pmu->pmu_enable) { | |
7847 | /* | |
7848 | * If we have pmu_enable/pmu_disable calls, install | |
7849 | * transaction stubs that use that to try and batch | |
7850 | * hardware accesses. | |
7851 | */ | |
7852 | pmu->start_txn = perf_pmu_start_txn; | |
7853 | pmu->commit_txn = perf_pmu_commit_txn; | |
7854 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7855 | } else { | |
fbbe0701 | 7856 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7857 | pmu->commit_txn = perf_pmu_nop_int; |
7858 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7859 | } |
5c92d124 | 7860 | } |
15dbf27c | 7861 | |
ad5133b7 PZ |
7862 | if (!pmu->pmu_enable) { |
7863 | pmu->pmu_enable = perf_pmu_nop_void; | |
7864 | pmu->pmu_disable = perf_pmu_nop_void; | |
7865 | } | |
7866 | ||
35edc2a5 PZ |
7867 | if (!pmu->event_idx) |
7868 | pmu->event_idx = perf_event_idx_default; | |
7869 | ||
b0a873eb | 7870 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7871 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7872 | ret = 0; |
7873 | unlock: | |
b0a873eb PZ |
7874 | mutex_unlock(&pmus_lock); |
7875 | ||
33696fc0 | 7876 | return ret; |
108b02cf | 7877 | |
abe43400 PZ |
7878 | free_dev: |
7879 | device_del(pmu->dev); | |
7880 | put_device(pmu->dev); | |
7881 | ||
2e80a82a PZ |
7882 | free_idr: |
7883 | if (pmu->type >= PERF_TYPE_MAX) | |
7884 | idr_remove(&pmu_idr, pmu->type); | |
7885 | ||
108b02cf PZ |
7886 | free_pdc: |
7887 | free_percpu(pmu->pmu_disable_count); | |
7888 | goto unlock; | |
f29ac756 | 7889 | } |
c464c76e | 7890 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7891 | |
b0a873eb | 7892 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7893 | { |
b0a873eb PZ |
7894 | mutex_lock(&pmus_lock); |
7895 | list_del_rcu(&pmu->entry); | |
7896 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7897 | |
0475f9ea | 7898 | /* |
cde8e884 PZ |
7899 | * We dereference the pmu list under both SRCU and regular RCU, so |
7900 | * synchronize against both of those. | |
0475f9ea | 7901 | */ |
b0a873eb | 7902 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7903 | synchronize_rcu(); |
d6d020e9 | 7904 | |
33696fc0 | 7905 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7906 | if (pmu->type >= PERF_TYPE_MAX) |
7907 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7908 | device_del(pmu->dev); |
7909 | put_device(pmu->dev); | |
51676957 | 7910 | free_pmu_context(pmu); |
b0a873eb | 7911 | } |
c464c76e | 7912 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7913 | |
cc34b98b MR |
7914 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7915 | { | |
ccd41c86 | 7916 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7917 | int ret; |
7918 | ||
7919 | if (!try_module_get(pmu->module)) | |
7920 | return -ENODEV; | |
ccd41c86 PZ |
7921 | |
7922 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7923 | /* |
7924 | * This ctx->mutex can nest when we're called through | |
7925 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7926 | */ | |
7927 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7928 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7929 | BUG_ON(!ctx); |
7930 | } | |
7931 | ||
cc34b98b MR |
7932 | event->pmu = pmu; |
7933 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7934 | |
7935 | if (ctx) | |
7936 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7937 | ||
cc34b98b MR |
7938 | if (ret) |
7939 | module_put(pmu->module); | |
7940 | ||
7941 | return ret; | |
7942 | } | |
7943 | ||
18ab2cd3 | 7944 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7945 | { |
7946 | struct pmu *pmu = NULL; | |
7947 | int idx; | |
940c5b29 | 7948 | int ret; |
b0a873eb PZ |
7949 | |
7950 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7951 | |
7952 | rcu_read_lock(); | |
7953 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7954 | rcu_read_unlock(); | |
940c5b29 | 7955 | if (pmu) { |
cc34b98b | 7956 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7957 | if (ret) |
7958 | pmu = ERR_PTR(ret); | |
2e80a82a | 7959 | goto unlock; |
940c5b29 | 7960 | } |
2e80a82a | 7961 | |
b0a873eb | 7962 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7963 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7964 | if (!ret) |
e5f4d339 | 7965 | goto unlock; |
76e1d904 | 7966 | |
b0a873eb PZ |
7967 | if (ret != -ENOENT) { |
7968 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7969 | goto unlock; |
f344011c | 7970 | } |
5c92d124 | 7971 | } |
e5f4d339 PZ |
7972 | pmu = ERR_PTR(-ENOENT); |
7973 | unlock: | |
b0a873eb | 7974 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7975 | |
4aeb0b42 | 7976 | return pmu; |
5c92d124 IM |
7977 | } |
7978 | ||
4beb31f3 FW |
7979 | static void account_event_cpu(struct perf_event *event, int cpu) |
7980 | { | |
7981 | if (event->parent) | |
7982 | return; | |
7983 | ||
4beb31f3 FW |
7984 | if (is_cgroup_event(event)) |
7985 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7986 | } | |
7987 | ||
555e0c1e FW |
7988 | /* Freq events need the tick to stay alive (see perf_event_task_tick). */ |
7989 | static void account_freq_event_nohz(void) | |
7990 | { | |
7991 | #ifdef CONFIG_NO_HZ_FULL | |
7992 | /* Lock so we don't race with concurrent unaccount */ | |
7993 | spin_lock(&nr_freq_lock); | |
7994 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7995 | tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS); | |
7996 | spin_unlock(&nr_freq_lock); | |
7997 | #endif | |
7998 | } | |
7999 | ||
8000 | static void account_freq_event(void) | |
8001 | { | |
8002 | if (tick_nohz_full_enabled()) | |
8003 | account_freq_event_nohz(); | |
8004 | else | |
8005 | atomic_inc(&nr_freq_events); | |
8006 | } | |
8007 | ||
8008 | ||
766d6c07 FW |
8009 | static void account_event(struct perf_event *event) |
8010 | { | |
25432ae9 PZ |
8011 | bool inc = false; |
8012 | ||
4beb31f3 FW |
8013 | if (event->parent) |
8014 | return; | |
8015 | ||
766d6c07 | 8016 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 8017 | inc = true; |
766d6c07 FW |
8018 | if (event->attr.mmap || event->attr.mmap_data) |
8019 | atomic_inc(&nr_mmap_events); | |
8020 | if (event->attr.comm) | |
8021 | atomic_inc(&nr_comm_events); | |
8022 | if (event->attr.task) | |
8023 | atomic_inc(&nr_task_events); | |
555e0c1e FW |
8024 | if (event->attr.freq) |
8025 | account_freq_event(); | |
45ac1403 AH |
8026 | if (event->attr.context_switch) { |
8027 | atomic_inc(&nr_switch_events); | |
25432ae9 | 8028 | inc = true; |
45ac1403 | 8029 | } |
4beb31f3 | 8030 | if (has_branch_stack(event)) |
25432ae9 | 8031 | inc = true; |
4beb31f3 | 8032 | if (is_cgroup_event(event)) |
25432ae9 PZ |
8033 | inc = true; |
8034 | ||
9107c89e PZ |
8035 | if (inc) { |
8036 | if (atomic_inc_not_zero(&perf_sched_count)) | |
8037 | goto enabled; | |
8038 | ||
8039 | mutex_lock(&perf_sched_mutex); | |
8040 | if (!atomic_read(&perf_sched_count)) { | |
8041 | static_branch_enable(&perf_sched_events); | |
8042 | /* | |
8043 | * Guarantee that all CPUs observe they key change and | |
8044 | * call the perf scheduling hooks before proceeding to | |
8045 | * install events that need them. | |
8046 | */ | |
8047 | synchronize_sched(); | |
8048 | } | |
8049 | /* | |
8050 | * Now that we have waited for the sync_sched(), allow further | |
8051 | * increments to by-pass the mutex. | |
8052 | */ | |
8053 | atomic_inc(&perf_sched_count); | |
8054 | mutex_unlock(&perf_sched_mutex); | |
8055 | } | |
8056 | enabled: | |
4beb31f3 FW |
8057 | |
8058 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
8059 | } |
8060 | ||
0793a61d | 8061 | /* |
cdd6c482 | 8062 | * Allocate and initialize a event structure |
0793a61d | 8063 | */ |
cdd6c482 | 8064 | static struct perf_event * |
c3f00c70 | 8065 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
8066 | struct task_struct *task, |
8067 | struct perf_event *group_leader, | |
8068 | struct perf_event *parent_event, | |
4dc0da86 | 8069 | perf_overflow_handler_t overflow_handler, |
79dff51e | 8070 | void *context, int cgroup_fd) |
0793a61d | 8071 | { |
51b0fe39 | 8072 | struct pmu *pmu; |
cdd6c482 IM |
8073 | struct perf_event *event; |
8074 | struct hw_perf_event *hwc; | |
90983b16 | 8075 | long err = -EINVAL; |
0793a61d | 8076 | |
66832eb4 ON |
8077 | if ((unsigned)cpu >= nr_cpu_ids) { |
8078 | if (!task || cpu != -1) | |
8079 | return ERR_PTR(-EINVAL); | |
8080 | } | |
8081 | ||
c3f00c70 | 8082 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 8083 | if (!event) |
d5d2bc0d | 8084 | return ERR_PTR(-ENOMEM); |
0793a61d | 8085 | |
04289bb9 | 8086 | /* |
cdd6c482 | 8087 | * Single events are their own group leaders, with an |
04289bb9 IM |
8088 | * empty sibling list: |
8089 | */ | |
8090 | if (!group_leader) | |
cdd6c482 | 8091 | group_leader = event; |
04289bb9 | 8092 | |
cdd6c482 IM |
8093 | mutex_init(&event->child_mutex); |
8094 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 8095 | |
cdd6c482 IM |
8096 | INIT_LIST_HEAD(&event->group_entry); |
8097 | INIT_LIST_HEAD(&event->event_entry); | |
8098 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 8099 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 8100 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
8101 | INIT_HLIST_NODE(&event->hlist_entry); |
8102 | ||
10c6db11 | 8103 | |
cdd6c482 | 8104 | init_waitqueue_head(&event->waitq); |
e360adbe | 8105 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 8106 | |
cdd6c482 | 8107 | mutex_init(&event->mmap_mutex); |
7b732a75 | 8108 | |
a6fa941d | 8109 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
8110 | event->cpu = cpu; |
8111 | event->attr = *attr; | |
8112 | event->group_leader = group_leader; | |
8113 | event->pmu = NULL; | |
cdd6c482 | 8114 | event->oncpu = -1; |
a96bbc16 | 8115 | |
cdd6c482 | 8116 | event->parent = parent_event; |
b84fbc9f | 8117 | |
17cf22c3 | 8118 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 8119 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 8120 | |
cdd6c482 | 8121 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 8122 | |
d580ff86 PZ |
8123 | if (task) { |
8124 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 8125 | /* |
50f16a8b PZ |
8126 | * XXX pmu::event_init needs to know what task to account to |
8127 | * and we cannot use the ctx information because we need the | |
8128 | * pmu before we get a ctx. | |
d580ff86 | 8129 | */ |
50f16a8b | 8130 | event->hw.target = task; |
d580ff86 PZ |
8131 | } |
8132 | ||
34f43927 PZ |
8133 | event->clock = &local_clock; |
8134 | if (parent_event) | |
8135 | event->clock = parent_event->clock; | |
8136 | ||
4dc0da86 | 8137 | if (!overflow_handler && parent_event) { |
b326e956 | 8138 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
8139 | context = parent_event->overflow_handler_context; |
8140 | } | |
66832eb4 | 8141 | |
b326e956 | 8142 | event->overflow_handler = overflow_handler; |
4dc0da86 | 8143 | event->overflow_handler_context = context; |
97eaf530 | 8144 | |
0231bb53 | 8145 | perf_event__state_init(event); |
a86ed508 | 8146 | |
4aeb0b42 | 8147 | pmu = NULL; |
b8e83514 | 8148 | |
cdd6c482 | 8149 | hwc = &event->hw; |
bd2b5b12 | 8150 | hwc->sample_period = attr->sample_period; |
0d48696f | 8151 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 8152 | hwc->sample_period = 1; |
eced1dfc | 8153 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 8154 | |
e7850595 | 8155 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 8156 | |
2023b359 | 8157 | /* |
cdd6c482 | 8158 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 8159 | */ |
3dab77fb | 8160 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 8161 | goto err_ns; |
a46a2300 YZ |
8162 | |
8163 | if (!has_branch_stack(event)) | |
8164 | event->attr.branch_sample_type = 0; | |
2023b359 | 8165 | |
79dff51e MF |
8166 | if (cgroup_fd != -1) { |
8167 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
8168 | if (err) | |
8169 | goto err_ns; | |
8170 | } | |
8171 | ||
b0a873eb | 8172 | pmu = perf_init_event(event); |
4aeb0b42 | 8173 | if (!pmu) |
90983b16 FW |
8174 | goto err_ns; |
8175 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 8176 | err = PTR_ERR(pmu); |
90983b16 | 8177 | goto err_ns; |
621a01ea | 8178 | } |
d5d2bc0d | 8179 | |
bed5b25a AS |
8180 | err = exclusive_event_init(event); |
8181 | if (err) | |
8182 | goto err_pmu; | |
8183 | ||
cdd6c482 | 8184 | if (!event->parent) { |
927c7a9e FW |
8185 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
8186 | err = get_callchain_buffers(); | |
90983b16 | 8187 | if (err) |
bed5b25a | 8188 | goto err_per_task; |
d010b332 | 8189 | } |
f344011c | 8190 | } |
9ee318a7 | 8191 | |
927a5570 AS |
8192 | /* symmetric to unaccount_event() in _free_event() */ |
8193 | account_event(event); | |
8194 | ||
cdd6c482 | 8195 | return event; |
90983b16 | 8196 | |
bed5b25a AS |
8197 | err_per_task: |
8198 | exclusive_event_destroy(event); | |
8199 | ||
90983b16 FW |
8200 | err_pmu: |
8201 | if (event->destroy) | |
8202 | event->destroy(event); | |
c464c76e | 8203 | module_put(pmu->module); |
90983b16 | 8204 | err_ns: |
79dff51e MF |
8205 | if (is_cgroup_event(event)) |
8206 | perf_detach_cgroup(event); | |
90983b16 FW |
8207 | if (event->ns) |
8208 | put_pid_ns(event->ns); | |
8209 | kfree(event); | |
8210 | ||
8211 | return ERR_PTR(err); | |
0793a61d TG |
8212 | } |
8213 | ||
cdd6c482 IM |
8214 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
8215 | struct perf_event_attr *attr) | |
974802ea | 8216 | { |
974802ea | 8217 | u32 size; |
cdf8073d | 8218 | int ret; |
974802ea PZ |
8219 | |
8220 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
8221 | return -EFAULT; | |
8222 | ||
8223 | /* | |
8224 | * zero the full structure, so that a short copy will be nice. | |
8225 | */ | |
8226 | memset(attr, 0, sizeof(*attr)); | |
8227 | ||
8228 | ret = get_user(size, &uattr->size); | |
8229 | if (ret) | |
8230 | return ret; | |
8231 | ||
8232 | if (size > PAGE_SIZE) /* silly large */ | |
8233 | goto err_size; | |
8234 | ||
8235 | if (!size) /* abi compat */ | |
8236 | size = PERF_ATTR_SIZE_VER0; | |
8237 | ||
8238 | if (size < PERF_ATTR_SIZE_VER0) | |
8239 | goto err_size; | |
8240 | ||
8241 | /* | |
8242 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
8243 | * ensure all the unknown bits are 0 - i.e. new |
8244 | * user-space does not rely on any kernel feature | |
8245 | * extensions we dont know about yet. | |
974802ea PZ |
8246 | */ |
8247 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
8248 | unsigned char __user *addr; |
8249 | unsigned char __user *end; | |
8250 | unsigned char val; | |
974802ea | 8251 | |
cdf8073d IS |
8252 | addr = (void __user *)uattr + sizeof(*attr); |
8253 | end = (void __user *)uattr + size; | |
974802ea | 8254 | |
cdf8073d | 8255 | for (; addr < end; addr++) { |
974802ea PZ |
8256 | ret = get_user(val, addr); |
8257 | if (ret) | |
8258 | return ret; | |
8259 | if (val) | |
8260 | goto err_size; | |
8261 | } | |
b3e62e35 | 8262 | size = sizeof(*attr); |
974802ea PZ |
8263 | } |
8264 | ||
8265 | ret = copy_from_user(attr, uattr, size); | |
8266 | if (ret) | |
8267 | return -EFAULT; | |
8268 | ||
cd757645 | 8269 | if (attr->__reserved_1) |
974802ea PZ |
8270 | return -EINVAL; |
8271 | ||
8272 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8273 | return -EINVAL; | |
8274 | ||
8275 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8276 | return -EINVAL; | |
8277 | ||
bce38cd5 SE |
8278 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8279 | u64 mask = attr->branch_sample_type; | |
8280 | ||
8281 | /* only using defined bits */ | |
8282 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8283 | return -EINVAL; | |
8284 | ||
8285 | /* at least one branch bit must be set */ | |
8286 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8287 | return -EINVAL; | |
8288 | ||
bce38cd5 SE |
8289 | /* propagate priv level, when not set for branch */ |
8290 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8291 | ||
8292 | /* exclude_kernel checked on syscall entry */ | |
8293 | if (!attr->exclude_kernel) | |
8294 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8295 | ||
8296 | if (!attr->exclude_user) | |
8297 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8298 | ||
8299 | if (!attr->exclude_hv) | |
8300 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8301 | /* | |
8302 | * adjust user setting (for HW filter setup) | |
8303 | */ | |
8304 | attr->branch_sample_type = mask; | |
8305 | } | |
e712209a SE |
8306 | /* privileged levels capture (kernel, hv): check permissions */ |
8307 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8308 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8309 | return -EACCES; | |
bce38cd5 | 8310 | } |
4018994f | 8311 | |
c5ebcedb | 8312 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8313 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8314 | if (ret) |
8315 | return ret; | |
8316 | } | |
8317 | ||
8318 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8319 | if (!arch_perf_have_user_stack_dump()) | |
8320 | return -ENOSYS; | |
8321 | ||
8322 | /* | |
8323 | * We have __u32 type for the size, but so far | |
8324 | * we can only use __u16 as maximum due to the | |
8325 | * __u16 sample size limit. | |
8326 | */ | |
8327 | if (attr->sample_stack_user >= USHRT_MAX) | |
8328 | ret = -EINVAL; | |
8329 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8330 | ret = -EINVAL; | |
8331 | } | |
4018994f | 8332 | |
60e2364e SE |
8333 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8334 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8335 | out: |
8336 | return ret; | |
8337 | ||
8338 | err_size: | |
8339 | put_user(sizeof(*attr), &uattr->size); | |
8340 | ret = -E2BIG; | |
8341 | goto out; | |
8342 | } | |
8343 | ||
ac9721f3 PZ |
8344 | static int |
8345 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8346 | { |
b69cf536 | 8347 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8348 | int ret = -EINVAL; |
8349 | ||
ac9721f3 | 8350 | if (!output_event) |
a4be7c27 PZ |
8351 | goto set; |
8352 | ||
ac9721f3 PZ |
8353 | /* don't allow circular references */ |
8354 | if (event == output_event) | |
a4be7c27 PZ |
8355 | goto out; |
8356 | ||
0f139300 PZ |
8357 | /* |
8358 | * Don't allow cross-cpu buffers | |
8359 | */ | |
8360 | if (output_event->cpu != event->cpu) | |
8361 | goto out; | |
8362 | ||
8363 | /* | |
76369139 | 8364 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8365 | */ |
8366 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8367 | goto out; | |
8368 | ||
34f43927 PZ |
8369 | /* |
8370 | * Mixing clocks in the same buffer is trouble you don't need. | |
8371 | */ | |
8372 | if (output_event->clock != event->clock) | |
8373 | goto out; | |
8374 | ||
45bfb2e5 PZ |
8375 | /* |
8376 | * If both events generate aux data, they must be on the same PMU | |
8377 | */ | |
8378 | if (has_aux(event) && has_aux(output_event) && | |
8379 | event->pmu != output_event->pmu) | |
8380 | goto out; | |
8381 | ||
a4be7c27 | 8382 | set: |
cdd6c482 | 8383 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8384 | /* Can't redirect output if we've got an active mmap() */ |
8385 | if (atomic_read(&event->mmap_count)) | |
8386 | goto unlock; | |
a4be7c27 | 8387 | |
ac9721f3 | 8388 | if (output_event) { |
76369139 FW |
8389 | /* get the rb we want to redirect to */ |
8390 | rb = ring_buffer_get(output_event); | |
8391 | if (!rb) | |
ac9721f3 | 8392 | goto unlock; |
a4be7c27 PZ |
8393 | } |
8394 | ||
b69cf536 | 8395 | ring_buffer_attach(event, rb); |
9bb5d40c | 8396 | |
a4be7c27 | 8397 | ret = 0; |
ac9721f3 PZ |
8398 | unlock: |
8399 | mutex_unlock(&event->mmap_mutex); | |
8400 | ||
a4be7c27 | 8401 | out: |
a4be7c27 PZ |
8402 | return ret; |
8403 | } | |
8404 | ||
f63a8daa PZ |
8405 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8406 | { | |
8407 | if (b < a) | |
8408 | swap(a, b); | |
8409 | ||
8410 | mutex_lock(a); | |
8411 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8412 | } | |
8413 | ||
34f43927 PZ |
8414 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8415 | { | |
8416 | bool nmi_safe = false; | |
8417 | ||
8418 | switch (clk_id) { | |
8419 | case CLOCK_MONOTONIC: | |
8420 | event->clock = &ktime_get_mono_fast_ns; | |
8421 | nmi_safe = true; | |
8422 | break; | |
8423 | ||
8424 | case CLOCK_MONOTONIC_RAW: | |
8425 | event->clock = &ktime_get_raw_fast_ns; | |
8426 | nmi_safe = true; | |
8427 | break; | |
8428 | ||
8429 | case CLOCK_REALTIME: | |
8430 | event->clock = &ktime_get_real_ns; | |
8431 | break; | |
8432 | ||
8433 | case CLOCK_BOOTTIME: | |
8434 | event->clock = &ktime_get_boot_ns; | |
8435 | break; | |
8436 | ||
8437 | case CLOCK_TAI: | |
8438 | event->clock = &ktime_get_tai_ns; | |
8439 | break; | |
8440 | ||
8441 | default: | |
8442 | return -EINVAL; | |
8443 | } | |
8444 | ||
8445 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8446 | return -EINVAL; | |
8447 | ||
8448 | return 0; | |
8449 | } | |
8450 | ||
0793a61d | 8451 | /** |
cdd6c482 | 8452 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8453 | * |
cdd6c482 | 8454 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8455 | * @pid: target pid |
9f66a381 | 8456 | * @cpu: target cpu |
cdd6c482 | 8457 | * @group_fd: group leader event fd |
0793a61d | 8458 | */ |
cdd6c482 IM |
8459 | SYSCALL_DEFINE5(perf_event_open, |
8460 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8461 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8462 | { |
b04243ef PZ |
8463 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8464 | struct perf_event *event, *sibling; | |
cdd6c482 | 8465 | struct perf_event_attr attr; |
f63a8daa | 8466 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8467 | struct file *event_file = NULL; |
2903ff01 | 8468 | struct fd group = {NULL, 0}; |
38a81da2 | 8469 | struct task_struct *task = NULL; |
89a1e187 | 8470 | struct pmu *pmu; |
ea635c64 | 8471 | int event_fd; |
b04243ef | 8472 | int move_group = 0; |
dc86cabe | 8473 | int err; |
a21b0b35 | 8474 | int f_flags = O_RDWR; |
79dff51e | 8475 | int cgroup_fd = -1; |
0793a61d | 8476 | |
2743a5b0 | 8477 | /* for future expandability... */ |
e5d1367f | 8478 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8479 | return -EINVAL; |
8480 | ||
dc86cabe IM |
8481 | err = perf_copy_attr(attr_uptr, &attr); |
8482 | if (err) | |
8483 | return err; | |
eab656ae | 8484 | |
0764771d PZ |
8485 | if (!attr.exclude_kernel) { |
8486 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8487 | return -EACCES; | |
8488 | } | |
8489 | ||
df58ab24 | 8490 | if (attr.freq) { |
cdd6c482 | 8491 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8492 | return -EINVAL; |
0819b2e3 PZ |
8493 | } else { |
8494 | if (attr.sample_period & (1ULL << 63)) | |
8495 | return -EINVAL; | |
df58ab24 PZ |
8496 | } |
8497 | ||
e5d1367f SE |
8498 | /* |
8499 | * In cgroup mode, the pid argument is used to pass the fd | |
8500 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8501 | * designates the cpu on which to monitor threads from that | |
8502 | * cgroup. | |
8503 | */ | |
8504 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8505 | return -EINVAL; | |
8506 | ||
a21b0b35 YD |
8507 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8508 | f_flags |= O_CLOEXEC; | |
8509 | ||
8510 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8511 | if (event_fd < 0) |
8512 | return event_fd; | |
8513 | ||
ac9721f3 | 8514 | if (group_fd != -1) { |
2903ff01 AV |
8515 | err = perf_fget_light(group_fd, &group); |
8516 | if (err) | |
d14b12d7 | 8517 | goto err_fd; |
2903ff01 | 8518 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8519 | if (flags & PERF_FLAG_FD_OUTPUT) |
8520 | output_event = group_leader; | |
8521 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8522 | group_leader = NULL; | |
8523 | } | |
8524 | ||
e5d1367f | 8525 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8526 | task = find_lively_task_by_vpid(pid); |
8527 | if (IS_ERR(task)) { | |
8528 | err = PTR_ERR(task); | |
8529 | goto err_group_fd; | |
8530 | } | |
8531 | } | |
8532 | ||
1f4ee503 PZ |
8533 | if (task && group_leader && |
8534 | group_leader->attr.inherit != attr.inherit) { | |
8535 | err = -EINVAL; | |
8536 | goto err_task; | |
8537 | } | |
8538 | ||
fbfc623f YZ |
8539 | get_online_cpus(); |
8540 | ||
79dff51e MF |
8541 | if (flags & PERF_FLAG_PID_CGROUP) |
8542 | cgroup_fd = pid; | |
8543 | ||
4dc0da86 | 8544 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8545 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8546 | if (IS_ERR(event)) { |
8547 | err = PTR_ERR(event); | |
1f4ee503 | 8548 | goto err_cpus; |
d14b12d7 SE |
8549 | } |
8550 | ||
53b25335 VW |
8551 | if (is_sampling_event(event)) { |
8552 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8553 | err = -ENOTSUPP; | |
8554 | goto err_alloc; | |
8555 | } | |
8556 | } | |
8557 | ||
89a1e187 PZ |
8558 | /* |
8559 | * Special case software events and allow them to be part of | |
8560 | * any hardware group. | |
8561 | */ | |
8562 | pmu = event->pmu; | |
b04243ef | 8563 | |
34f43927 PZ |
8564 | if (attr.use_clockid) { |
8565 | err = perf_event_set_clock(event, attr.clockid); | |
8566 | if (err) | |
8567 | goto err_alloc; | |
8568 | } | |
8569 | ||
b04243ef PZ |
8570 | if (group_leader && |
8571 | (is_software_event(event) != is_software_event(group_leader))) { | |
8572 | if (is_software_event(event)) { | |
8573 | /* | |
8574 | * If event and group_leader are not both a software | |
8575 | * event, and event is, then group leader is not. | |
8576 | * | |
8577 | * Allow the addition of software events to !software | |
8578 | * groups, this is safe because software events never | |
8579 | * fail to schedule. | |
8580 | */ | |
8581 | pmu = group_leader->pmu; | |
8582 | } else if (is_software_event(group_leader) && | |
8583 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8584 | /* | |
8585 | * In case the group is a pure software group, and we | |
8586 | * try to add a hardware event, move the whole group to | |
8587 | * the hardware context. | |
8588 | */ | |
8589 | move_group = 1; | |
8590 | } | |
8591 | } | |
89a1e187 PZ |
8592 | |
8593 | /* | |
8594 | * Get the target context (task or percpu): | |
8595 | */ | |
4af57ef2 | 8596 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8597 | if (IS_ERR(ctx)) { |
8598 | err = PTR_ERR(ctx); | |
c6be5a5c | 8599 | goto err_alloc; |
89a1e187 PZ |
8600 | } |
8601 | ||
bed5b25a AS |
8602 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8603 | err = -EBUSY; | |
8604 | goto err_context; | |
8605 | } | |
8606 | ||
fd1edb3a PZ |
8607 | if (task) { |
8608 | put_task_struct(task); | |
8609 | task = NULL; | |
8610 | } | |
8611 | ||
ccff286d | 8612 | /* |
cdd6c482 | 8613 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8614 | */ |
ac9721f3 | 8615 | if (group_leader) { |
dc86cabe | 8616 | err = -EINVAL; |
04289bb9 | 8617 | |
04289bb9 | 8618 | /* |
ccff286d IM |
8619 | * Do not allow a recursive hierarchy (this new sibling |
8620 | * becoming part of another group-sibling): | |
8621 | */ | |
8622 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8623 | goto err_context; |
34f43927 PZ |
8624 | |
8625 | /* All events in a group should have the same clock */ | |
8626 | if (group_leader->clock != event->clock) | |
8627 | goto err_context; | |
8628 | ||
ccff286d IM |
8629 | /* |
8630 | * Do not allow to attach to a group in a different | |
8631 | * task or CPU context: | |
04289bb9 | 8632 | */ |
b04243ef | 8633 | if (move_group) { |
c3c87e77 PZ |
8634 | /* |
8635 | * Make sure we're both on the same task, or both | |
8636 | * per-cpu events. | |
8637 | */ | |
8638 | if (group_leader->ctx->task != ctx->task) | |
8639 | goto err_context; | |
8640 | ||
8641 | /* | |
8642 | * Make sure we're both events for the same CPU; | |
8643 | * grouping events for different CPUs is broken; since | |
8644 | * you can never concurrently schedule them anyhow. | |
8645 | */ | |
8646 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8647 | goto err_context; |
8648 | } else { | |
8649 | if (group_leader->ctx != ctx) | |
8650 | goto err_context; | |
8651 | } | |
8652 | ||
3b6f9e5c PM |
8653 | /* |
8654 | * Only a group leader can be exclusive or pinned | |
8655 | */ | |
0d48696f | 8656 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8657 | goto err_context; |
ac9721f3 PZ |
8658 | } |
8659 | ||
8660 | if (output_event) { | |
8661 | err = perf_event_set_output(event, output_event); | |
8662 | if (err) | |
c3f00c70 | 8663 | goto err_context; |
ac9721f3 | 8664 | } |
0793a61d | 8665 | |
a21b0b35 YD |
8666 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8667 | f_flags); | |
ea635c64 AV |
8668 | if (IS_ERR(event_file)) { |
8669 | err = PTR_ERR(event_file); | |
201c2f85 | 8670 | event_file = NULL; |
c3f00c70 | 8671 | goto err_context; |
ea635c64 | 8672 | } |
9b51f66d | 8673 | |
b04243ef | 8674 | if (move_group) { |
f63a8daa | 8675 | gctx = group_leader->ctx; |
f55fc2a5 | 8676 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
84c4e620 PZ |
8677 | if (gctx->task == TASK_TOMBSTONE) { |
8678 | err = -ESRCH; | |
8679 | goto err_locked; | |
8680 | } | |
f55fc2a5 PZ |
8681 | } else { |
8682 | mutex_lock(&ctx->mutex); | |
8683 | } | |
8684 | ||
84c4e620 PZ |
8685 | if (ctx->task == TASK_TOMBSTONE) { |
8686 | err = -ESRCH; | |
8687 | goto err_locked; | |
8688 | } | |
8689 | ||
a723968c PZ |
8690 | if (!perf_event_validate_size(event)) { |
8691 | err = -E2BIG; | |
8692 | goto err_locked; | |
8693 | } | |
8694 | ||
f55fc2a5 PZ |
8695 | /* |
8696 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8697 | * because we need to serialize with concurrent event creation. | |
8698 | */ | |
8699 | if (!exclusive_event_installable(event, ctx)) { | |
8700 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8701 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8702 | |
f55fc2a5 PZ |
8703 | err = -EBUSY; |
8704 | goto err_locked; | |
8705 | } | |
f63a8daa | 8706 | |
f55fc2a5 PZ |
8707 | WARN_ON_ONCE(ctx->parent_ctx); |
8708 | ||
8709 | if (move_group) { | |
f63a8daa PZ |
8710 | /* |
8711 | * See perf_event_ctx_lock() for comments on the details | |
8712 | * of swizzling perf_event::ctx. | |
8713 | */ | |
45a0e07a | 8714 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8715 | |
b04243ef PZ |
8716 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8717 | group_entry) { | |
45a0e07a | 8718 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8719 | put_ctx(gctx); |
8720 | } | |
b04243ef | 8721 | |
f63a8daa PZ |
8722 | /* |
8723 | * Wait for everybody to stop referencing the events through | |
8724 | * the old lists, before installing it on new lists. | |
8725 | */ | |
0cda4c02 | 8726 | synchronize_rcu(); |
f63a8daa | 8727 | |
8f95b435 PZI |
8728 | /* |
8729 | * Install the group siblings before the group leader. | |
8730 | * | |
8731 | * Because a group leader will try and install the entire group | |
8732 | * (through the sibling list, which is still in-tact), we can | |
8733 | * end up with siblings installed in the wrong context. | |
8734 | * | |
8735 | * By installing siblings first we NO-OP because they're not | |
8736 | * reachable through the group lists. | |
8737 | */ | |
b04243ef PZ |
8738 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8739 | group_entry) { | |
8f95b435 | 8740 | perf_event__state_init(sibling); |
9fc81d87 | 8741 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8742 | get_ctx(ctx); |
8743 | } | |
8f95b435 PZI |
8744 | |
8745 | /* | |
8746 | * Removing from the context ends up with disabled | |
8747 | * event. What we want here is event in the initial | |
8748 | * startup state, ready to be add into new context. | |
8749 | */ | |
8750 | perf_event__state_init(group_leader); | |
8751 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8752 | get_ctx(ctx); | |
b04243ef | 8753 | |
f55fc2a5 PZ |
8754 | /* |
8755 | * Now that all events are installed in @ctx, nothing | |
8756 | * references @gctx anymore, so drop the last reference we have | |
8757 | * on it. | |
8758 | */ | |
8759 | put_ctx(gctx); | |
bed5b25a AS |
8760 | } |
8761 | ||
f73e22ab PZ |
8762 | /* |
8763 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8764 | * that we're serialized against further additions and before | |
8765 | * perf_install_in_context() which is the point the event is active and | |
8766 | * can use these values. | |
8767 | */ | |
8768 | perf_event__header_size(event); | |
8769 | perf_event__id_header_size(event); | |
8770 | ||
78cd2c74 PZ |
8771 | event->owner = current; |
8772 | ||
e2d37cd2 | 8773 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8774 | perf_unpin_context(ctx); |
f63a8daa | 8775 | |
f55fc2a5 | 8776 | if (move_group) |
f63a8daa | 8777 | mutex_unlock(&gctx->mutex); |
d859e29f | 8778 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8779 | |
fbfc623f YZ |
8780 | put_online_cpus(); |
8781 | ||
cdd6c482 IM |
8782 | mutex_lock(¤t->perf_event_mutex); |
8783 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8784 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8785 | |
8a49542c PZ |
8786 | /* |
8787 | * Drop the reference on the group_event after placing the | |
8788 | * new event on the sibling_list. This ensures destruction | |
8789 | * of the group leader will find the pointer to itself in | |
8790 | * perf_group_detach(). | |
8791 | */ | |
2903ff01 | 8792 | fdput(group); |
ea635c64 AV |
8793 | fd_install(event_fd, event_file); |
8794 | return event_fd; | |
0793a61d | 8795 | |
f55fc2a5 PZ |
8796 | err_locked: |
8797 | if (move_group) | |
8798 | mutex_unlock(&gctx->mutex); | |
8799 | mutex_unlock(&ctx->mutex); | |
8800 | /* err_file: */ | |
8801 | fput(event_file); | |
c3f00c70 | 8802 | err_context: |
fe4b04fa | 8803 | perf_unpin_context(ctx); |
ea635c64 | 8804 | put_ctx(ctx); |
c6be5a5c | 8805 | err_alloc: |
13005627 PZ |
8806 | /* |
8807 | * If event_file is set, the fput() above will have called ->release() | |
8808 | * and that will take care of freeing the event. | |
8809 | */ | |
8810 | if (!event_file) | |
8811 | free_event(event); | |
1f4ee503 | 8812 | err_cpus: |
fbfc623f | 8813 | put_online_cpus(); |
1f4ee503 | 8814 | err_task: |
e7d0bc04 PZ |
8815 | if (task) |
8816 | put_task_struct(task); | |
89a1e187 | 8817 | err_group_fd: |
2903ff01 | 8818 | fdput(group); |
ea635c64 AV |
8819 | err_fd: |
8820 | put_unused_fd(event_fd); | |
dc86cabe | 8821 | return err; |
0793a61d TG |
8822 | } |
8823 | ||
fb0459d7 AV |
8824 | /** |
8825 | * perf_event_create_kernel_counter | |
8826 | * | |
8827 | * @attr: attributes of the counter to create | |
8828 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8829 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8830 | */ |
8831 | struct perf_event * | |
8832 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8833 | struct task_struct *task, |
4dc0da86 AK |
8834 | perf_overflow_handler_t overflow_handler, |
8835 | void *context) | |
fb0459d7 | 8836 | { |
fb0459d7 | 8837 | struct perf_event_context *ctx; |
c3f00c70 | 8838 | struct perf_event *event; |
fb0459d7 | 8839 | int err; |
d859e29f | 8840 | |
fb0459d7 AV |
8841 | /* |
8842 | * Get the target context (task or percpu): | |
8843 | */ | |
d859e29f | 8844 | |
4dc0da86 | 8845 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8846 | overflow_handler, context, -1); |
c3f00c70 PZ |
8847 | if (IS_ERR(event)) { |
8848 | err = PTR_ERR(event); | |
8849 | goto err; | |
8850 | } | |
d859e29f | 8851 | |
f8697762 | 8852 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8853 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8854 | |
4af57ef2 | 8855 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8856 | if (IS_ERR(ctx)) { |
8857 | err = PTR_ERR(ctx); | |
c3f00c70 | 8858 | goto err_free; |
d859e29f | 8859 | } |
fb0459d7 | 8860 | |
fb0459d7 AV |
8861 | WARN_ON_ONCE(ctx->parent_ctx); |
8862 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
8863 | if (ctx->task == TASK_TOMBSTONE) { |
8864 | err = -ESRCH; | |
8865 | goto err_unlock; | |
8866 | } | |
8867 | ||
bed5b25a | 8868 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 8869 | err = -EBUSY; |
84c4e620 | 8870 | goto err_unlock; |
bed5b25a AS |
8871 | } |
8872 | ||
fb0459d7 | 8873 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8874 | perf_unpin_context(ctx); |
fb0459d7 AV |
8875 | mutex_unlock(&ctx->mutex); |
8876 | ||
fb0459d7 AV |
8877 | return event; |
8878 | ||
84c4e620 PZ |
8879 | err_unlock: |
8880 | mutex_unlock(&ctx->mutex); | |
8881 | perf_unpin_context(ctx); | |
8882 | put_ctx(ctx); | |
c3f00c70 PZ |
8883 | err_free: |
8884 | free_event(event); | |
8885 | err: | |
c6567f64 | 8886 | return ERR_PTR(err); |
9b51f66d | 8887 | } |
fb0459d7 | 8888 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8889 | |
0cda4c02 YZ |
8890 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8891 | { | |
8892 | struct perf_event_context *src_ctx; | |
8893 | struct perf_event_context *dst_ctx; | |
8894 | struct perf_event *event, *tmp; | |
8895 | LIST_HEAD(events); | |
8896 | ||
8897 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8898 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8899 | ||
f63a8daa PZ |
8900 | /* |
8901 | * See perf_event_ctx_lock() for comments on the details | |
8902 | * of swizzling perf_event::ctx. | |
8903 | */ | |
8904 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8905 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8906 | event_entry) { | |
45a0e07a | 8907 | perf_remove_from_context(event, 0); |
9a545de0 | 8908 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8909 | put_ctx(src_ctx); |
9886167d | 8910 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8911 | } |
0cda4c02 | 8912 | |
8f95b435 PZI |
8913 | /* |
8914 | * Wait for the events to quiesce before re-instating them. | |
8915 | */ | |
0cda4c02 YZ |
8916 | synchronize_rcu(); |
8917 | ||
8f95b435 PZI |
8918 | /* |
8919 | * Re-instate events in 2 passes. | |
8920 | * | |
8921 | * Skip over group leaders and only install siblings on this first | |
8922 | * pass, siblings will not get enabled without a leader, however a | |
8923 | * leader will enable its siblings, even if those are still on the old | |
8924 | * context. | |
8925 | */ | |
8926 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8927 | if (event->group_leader == event) | |
8928 | continue; | |
8929 | ||
8930 | list_del(&event->migrate_entry); | |
8931 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8932 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8933 | account_event_cpu(event, dst_cpu); | |
8934 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8935 | get_ctx(dst_ctx); | |
8936 | } | |
8937 | ||
8938 | /* | |
8939 | * Once all the siblings are setup properly, install the group leaders | |
8940 | * to make it go. | |
8941 | */ | |
9886167d PZ |
8942 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8943 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8944 | if (event->state >= PERF_EVENT_STATE_OFF) |
8945 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8946 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8947 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8948 | get_ctx(dst_ctx); | |
8949 | } | |
8950 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8951 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8952 | } |
8953 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8954 | ||
cdd6c482 | 8955 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8956 | struct task_struct *child) |
d859e29f | 8957 | { |
cdd6c482 | 8958 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8959 | u64 child_val; |
d859e29f | 8960 | |
cdd6c482 IM |
8961 | if (child_event->attr.inherit_stat) |
8962 | perf_event_read_event(child_event, child); | |
38b200d6 | 8963 | |
b5e58793 | 8964 | child_val = perf_event_count(child_event); |
d859e29f PM |
8965 | |
8966 | /* | |
8967 | * Add back the child's count to the parent's count: | |
8968 | */ | |
a6e6dea6 | 8969 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8970 | atomic64_add(child_event->total_time_enabled, |
8971 | &parent_event->child_total_time_enabled); | |
8972 | atomic64_add(child_event->total_time_running, | |
8973 | &parent_event->child_total_time_running); | |
d859e29f PM |
8974 | } |
8975 | ||
9b51f66d | 8976 | static void |
8ba289b8 PZ |
8977 | perf_event_exit_event(struct perf_event *child_event, |
8978 | struct perf_event_context *child_ctx, | |
8979 | struct task_struct *child) | |
9b51f66d | 8980 | { |
8ba289b8 PZ |
8981 | struct perf_event *parent_event = child_event->parent; |
8982 | ||
1903d50c PZ |
8983 | /* |
8984 | * Do not destroy the 'original' grouping; because of the context | |
8985 | * switch optimization the original events could've ended up in a | |
8986 | * random child task. | |
8987 | * | |
8988 | * If we were to destroy the original group, all group related | |
8989 | * operations would cease to function properly after this random | |
8990 | * child dies. | |
8991 | * | |
8992 | * Do destroy all inherited groups, we don't care about those | |
8993 | * and being thorough is better. | |
8994 | */ | |
32132a3d PZ |
8995 | raw_spin_lock_irq(&child_ctx->lock); |
8996 | WARN_ON_ONCE(child_ctx->is_active); | |
8997 | ||
8ba289b8 | 8998 | if (parent_event) |
32132a3d PZ |
8999 | perf_group_detach(child_event); |
9000 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 9001 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 9002 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 9003 | |
9b51f66d | 9004 | /* |
8ba289b8 | 9005 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 9006 | */ |
8ba289b8 | 9007 | if (!parent_event) { |
179033b3 | 9008 | perf_event_wakeup(child_event); |
8ba289b8 | 9009 | return; |
4bcf349a | 9010 | } |
8ba289b8 PZ |
9011 | /* |
9012 | * Child events can be cleaned up. | |
9013 | */ | |
9014 | ||
9015 | sync_child_event(child_event, child); | |
9016 | ||
9017 | /* | |
9018 | * Remove this event from the parent's list | |
9019 | */ | |
9020 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
9021 | mutex_lock(&parent_event->child_mutex); | |
9022 | list_del_init(&child_event->child_list); | |
9023 | mutex_unlock(&parent_event->child_mutex); | |
9024 | ||
9025 | /* | |
9026 | * Kick perf_poll() for is_event_hup(). | |
9027 | */ | |
9028 | perf_event_wakeup(parent_event); | |
9029 | free_event(child_event); | |
9030 | put_event(parent_event); | |
9b51f66d IM |
9031 | } |
9032 | ||
8dc85d54 | 9033 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 9034 | { |
211de6eb | 9035 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 9036 | struct perf_event *child_event, *next; |
63b6da39 PZ |
9037 | |
9038 | WARN_ON_ONCE(child != current); | |
9b51f66d | 9039 | |
6a3351b6 | 9040 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 9041 | if (!child_ctx) |
9b51f66d IM |
9042 | return; |
9043 | ||
ad3a37de | 9044 | /* |
6a3351b6 PZ |
9045 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
9046 | * ctx::mutex over the entire thing. This serializes against almost | |
9047 | * everything that wants to access the ctx. | |
9048 | * | |
9049 | * The exception is sys_perf_event_open() / | |
9050 | * perf_event_create_kernel_count() which does find_get_context() | |
9051 | * without ctx::mutex (it cannot because of the move_group double mutex | |
9052 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 9053 | */ |
6a3351b6 | 9054 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
9055 | |
9056 | /* | |
6a3351b6 PZ |
9057 | * In a single ctx::lock section, de-schedule the events and detach the |
9058 | * context from the task such that we cannot ever get it scheduled back | |
9059 | * in. | |
c93f7669 | 9060 | */ |
6a3351b6 | 9061 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 9062 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 9063 | |
71a851b4 | 9064 | /* |
63b6da39 PZ |
9065 | * Now that the context is inactive, destroy the task <-> ctx relation |
9066 | * and mark the context dead. | |
71a851b4 | 9067 | */ |
63b6da39 PZ |
9068 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
9069 | put_ctx(child_ctx); /* cannot be last */ | |
9070 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
9071 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 9072 | |
211de6eb | 9073 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 9074 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 9075 | |
211de6eb PZ |
9076 | if (clone_ctx) |
9077 | put_ctx(clone_ctx); | |
4a1c0f26 | 9078 | |
9f498cc5 | 9079 | /* |
cdd6c482 IM |
9080 | * Report the task dead after unscheduling the events so that we |
9081 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
9082 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 9083 | */ |
cdd6c482 | 9084 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 9085 | |
ebf905fc | 9086 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 9087 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 9088 | |
a63eaf34 PM |
9089 | mutex_unlock(&child_ctx->mutex); |
9090 | ||
9091 | put_ctx(child_ctx); | |
9b51f66d IM |
9092 | } |
9093 | ||
8dc85d54 PZ |
9094 | /* |
9095 | * When a child task exits, feed back event values to parent events. | |
9096 | */ | |
9097 | void perf_event_exit_task(struct task_struct *child) | |
9098 | { | |
8882135b | 9099 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
9100 | int ctxn; |
9101 | ||
8882135b PZ |
9102 | mutex_lock(&child->perf_event_mutex); |
9103 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
9104 | owner_entry) { | |
9105 | list_del_init(&event->owner_entry); | |
9106 | ||
9107 | /* | |
9108 | * Ensure the list deletion is visible before we clear | |
9109 | * the owner, closes a race against perf_release() where | |
9110 | * we need to serialize on the owner->perf_event_mutex. | |
9111 | */ | |
f47c02c0 | 9112 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
9113 | } |
9114 | mutex_unlock(&child->perf_event_mutex); | |
9115 | ||
8dc85d54 PZ |
9116 | for_each_task_context_nr(ctxn) |
9117 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
9118 | |
9119 | /* | |
9120 | * The perf_event_exit_task_context calls perf_event_task | |
9121 | * with child's task_ctx, which generates EXIT events for | |
9122 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
9123 | * At this point we need to send EXIT events to cpu contexts. | |
9124 | */ | |
9125 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
9126 | } |
9127 | ||
889ff015 FW |
9128 | static void perf_free_event(struct perf_event *event, |
9129 | struct perf_event_context *ctx) | |
9130 | { | |
9131 | struct perf_event *parent = event->parent; | |
9132 | ||
9133 | if (WARN_ON_ONCE(!parent)) | |
9134 | return; | |
9135 | ||
9136 | mutex_lock(&parent->child_mutex); | |
9137 | list_del_init(&event->child_list); | |
9138 | mutex_unlock(&parent->child_mutex); | |
9139 | ||
a6fa941d | 9140 | put_event(parent); |
889ff015 | 9141 | |
652884fe | 9142 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 9143 | perf_group_detach(event); |
889ff015 | 9144 | list_del_event(event, ctx); |
652884fe | 9145 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
9146 | free_event(event); |
9147 | } | |
9148 | ||
bbbee908 | 9149 | /* |
652884fe | 9150 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 9151 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
9152 | * |
9153 | * Not all locks are strictly required, but take them anyway to be nice and | |
9154 | * help out with the lockdep assertions. | |
bbbee908 | 9155 | */ |
cdd6c482 | 9156 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 9157 | { |
8dc85d54 | 9158 | struct perf_event_context *ctx; |
cdd6c482 | 9159 | struct perf_event *event, *tmp; |
8dc85d54 | 9160 | int ctxn; |
bbbee908 | 9161 | |
8dc85d54 PZ |
9162 | for_each_task_context_nr(ctxn) { |
9163 | ctx = task->perf_event_ctxp[ctxn]; | |
9164 | if (!ctx) | |
9165 | continue; | |
bbbee908 | 9166 | |
8dc85d54 | 9167 | mutex_lock(&ctx->mutex); |
bbbee908 | 9168 | again: |
8dc85d54 PZ |
9169 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
9170 | group_entry) | |
9171 | perf_free_event(event, ctx); | |
bbbee908 | 9172 | |
8dc85d54 PZ |
9173 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
9174 | group_entry) | |
9175 | perf_free_event(event, ctx); | |
bbbee908 | 9176 | |
8dc85d54 PZ |
9177 | if (!list_empty(&ctx->pinned_groups) || |
9178 | !list_empty(&ctx->flexible_groups)) | |
9179 | goto again; | |
bbbee908 | 9180 | |
8dc85d54 | 9181 | mutex_unlock(&ctx->mutex); |
bbbee908 | 9182 | |
8dc85d54 PZ |
9183 | put_ctx(ctx); |
9184 | } | |
889ff015 FW |
9185 | } |
9186 | ||
4e231c79 PZ |
9187 | void perf_event_delayed_put(struct task_struct *task) |
9188 | { | |
9189 | int ctxn; | |
9190 | ||
9191 | for_each_task_context_nr(ctxn) | |
9192 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
9193 | } | |
9194 | ||
e03e7ee3 | 9195 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 9196 | { |
e03e7ee3 | 9197 | struct file *file; |
ffe8690c | 9198 | |
e03e7ee3 AS |
9199 | file = fget_raw(fd); |
9200 | if (!file) | |
9201 | return ERR_PTR(-EBADF); | |
ffe8690c | 9202 | |
e03e7ee3 AS |
9203 | if (file->f_op != &perf_fops) { |
9204 | fput(file); | |
9205 | return ERR_PTR(-EBADF); | |
9206 | } | |
ffe8690c | 9207 | |
e03e7ee3 | 9208 | return file; |
ffe8690c KX |
9209 | } |
9210 | ||
9211 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
9212 | { | |
9213 | if (!event) | |
9214 | return ERR_PTR(-EINVAL); | |
9215 | ||
9216 | return &event->attr; | |
9217 | } | |
9218 | ||
97dee4f3 PZ |
9219 | /* |
9220 | * inherit a event from parent task to child task: | |
9221 | */ | |
9222 | static struct perf_event * | |
9223 | inherit_event(struct perf_event *parent_event, | |
9224 | struct task_struct *parent, | |
9225 | struct perf_event_context *parent_ctx, | |
9226 | struct task_struct *child, | |
9227 | struct perf_event *group_leader, | |
9228 | struct perf_event_context *child_ctx) | |
9229 | { | |
1929def9 | 9230 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 9231 | struct perf_event *child_event; |
cee010ec | 9232 | unsigned long flags; |
97dee4f3 PZ |
9233 | |
9234 | /* | |
9235 | * Instead of creating recursive hierarchies of events, | |
9236 | * we link inherited events back to the original parent, | |
9237 | * which has a filp for sure, which we use as the reference | |
9238 | * count: | |
9239 | */ | |
9240 | if (parent_event->parent) | |
9241 | parent_event = parent_event->parent; | |
9242 | ||
9243 | child_event = perf_event_alloc(&parent_event->attr, | |
9244 | parent_event->cpu, | |
d580ff86 | 9245 | child, |
97dee4f3 | 9246 | group_leader, parent_event, |
79dff51e | 9247 | NULL, NULL, -1); |
97dee4f3 PZ |
9248 | if (IS_ERR(child_event)) |
9249 | return child_event; | |
a6fa941d | 9250 | |
c6e5b732 PZ |
9251 | /* |
9252 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
9253 | * must be under the same lock in order to serialize against | |
9254 | * perf_event_release_kernel(), such that either we must observe | |
9255 | * is_orphaned_event() or they will observe us on the child_list. | |
9256 | */ | |
9257 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
9258 | if (is_orphaned_event(parent_event) || |
9259 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 9260 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
9261 | free_event(child_event); |
9262 | return NULL; | |
9263 | } | |
9264 | ||
97dee4f3 PZ |
9265 | get_ctx(child_ctx); |
9266 | ||
9267 | /* | |
9268 | * Make the child state follow the state of the parent event, | |
9269 | * not its attr.disabled bit. We hold the parent's mutex, | |
9270 | * so we won't race with perf_event_{en, dis}able_family. | |
9271 | */ | |
1929def9 | 9272 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
9273 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
9274 | else | |
9275 | child_event->state = PERF_EVENT_STATE_OFF; | |
9276 | ||
9277 | if (parent_event->attr.freq) { | |
9278 | u64 sample_period = parent_event->hw.sample_period; | |
9279 | struct hw_perf_event *hwc = &child_event->hw; | |
9280 | ||
9281 | hwc->sample_period = sample_period; | |
9282 | hwc->last_period = sample_period; | |
9283 | ||
9284 | local64_set(&hwc->period_left, sample_period); | |
9285 | } | |
9286 | ||
9287 | child_event->ctx = child_ctx; | |
9288 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9289 | child_event->overflow_handler_context |
9290 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9291 | |
614b6780 TG |
9292 | /* |
9293 | * Precalculate sample_data sizes | |
9294 | */ | |
9295 | perf_event__header_size(child_event); | |
6844c09d | 9296 | perf_event__id_header_size(child_event); |
614b6780 | 9297 | |
97dee4f3 PZ |
9298 | /* |
9299 | * Link it up in the child's context: | |
9300 | */ | |
cee010ec | 9301 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9302 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9303 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9304 | |
97dee4f3 PZ |
9305 | /* |
9306 | * Link this into the parent event's child list | |
9307 | */ | |
97dee4f3 PZ |
9308 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9309 | mutex_unlock(&parent_event->child_mutex); | |
9310 | ||
9311 | return child_event; | |
9312 | } | |
9313 | ||
9314 | static int inherit_group(struct perf_event *parent_event, | |
9315 | struct task_struct *parent, | |
9316 | struct perf_event_context *parent_ctx, | |
9317 | struct task_struct *child, | |
9318 | struct perf_event_context *child_ctx) | |
9319 | { | |
9320 | struct perf_event *leader; | |
9321 | struct perf_event *sub; | |
9322 | struct perf_event *child_ctr; | |
9323 | ||
9324 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9325 | child, NULL, child_ctx); | |
9326 | if (IS_ERR(leader)) | |
9327 | return PTR_ERR(leader); | |
9328 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9329 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9330 | child, leader, child_ctx); | |
9331 | if (IS_ERR(child_ctr)) | |
9332 | return PTR_ERR(child_ctr); | |
9333 | } | |
9334 | return 0; | |
889ff015 FW |
9335 | } |
9336 | ||
9337 | static int | |
9338 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9339 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9340 | struct task_struct *child, int ctxn, |
889ff015 FW |
9341 | int *inherited_all) |
9342 | { | |
9343 | int ret; | |
8dc85d54 | 9344 | struct perf_event_context *child_ctx; |
889ff015 FW |
9345 | |
9346 | if (!event->attr.inherit) { | |
9347 | *inherited_all = 0; | |
9348 | return 0; | |
bbbee908 PZ |
9349 | } |
9350 | ||
fe4b04fa | 9351 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9352 | if (!child_ctx) { |
9353 | /* | |
9354 | * This is executed from the parent task context, so | |
9355 | * inherit events that have been marked for cloning. | |
9356 | * First allocate and initialize a context for the | |
9357 | * child. | |
9358 | */ | |
bbbee908 | 9359 | |
734df5ab | 9360 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9361 | if (!child_ctx) |
9362 | return -ENOMEM; | |
bbbee908 | 9363 | |
8dc85d54 | 9364 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9365 | } |
9366 | ||
9367 | ret = inherit_group(event, parent, parent_ctx, | |
9368 | child, child_ctx); | |
9369 | ||
9370 | if (ret) | |
9371 | *inherited_all = 0; | |
9372 | ||
9373 | return ret; | |
bbbee908 PZ |
9374 | } |
9375 | ||
9b51f66d | 9376 | /* |
cdd6c482 | 9377 | * Initialize the perf_event context in task_struct |
9b51f66d | 9378 | */ |
985c8dcb | 9379 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9380 | { |
889ff015 | 9381 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9382 | struct perf_event_context *cloned_ctx; |
9383 | struct perf_event *event; | |
9b51f66d | 9384 | struct task_struct *parent = current; |
564c2b21 | 9385 | int inherited_all = 1; |
dddd3379 | 9386 | unsigned long flags; |
6ab423e0 | 9387 | int ret = 0; |
9b51f66d | 9388 | |
8dc85d54 | 9389 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9390 | return 0; |
9391 | ||
ad3a37de | 9392 | /* |
25346b93 PM |
9393 | * If the parent's context is a clone, pin it so it won't get |
9394 | * swapped under us. | |
ad3a37de | 9395 | */ |
8dc85d54 | 9396 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9397 | if (!parent_ctx) |
9398 | return 0; | |
25346b93 | 9399 | |
ad3a37de PM |
9400 | /* |
9401 | * No need to check if parent_ctx != NULL here; since we saw | |
9402 | * it non-NULL earlier, the only reason for it to become NULL | |
9403 | * is if we exit, and since we're currently in the middle of | |
9404 | * a fork we can't be exiting at the same time. | |
9405 | */ | |
ad3a37de | 9406 | |
9b51f66d IM |
9407 | /* |
9408 | * Lock the parent list. No need to lock the child - not PID | |
9409 | * hashed yet and not running, so nobody can access it. | |
9410 | */ | |
d859e29f | 9411 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9412 | |
9413 | /* | |
9414 | * We dont have to disable NMIs - we are only looking at | |
9415 | * the list, not manipulating it: | |
9416 | */ | |
889ff015 | 9417 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9418 | ret = inherit_task_group(event, parent, parent_ctx, |
9419 | child, ctxn, &inherited_all); | |
889ff015 FW |
9420 | if (ret) |
9421 | break; | |
9422 | } | |
b93f7978 | 9423 | |
dddd3379 TG |
9424 | /* |
9425 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9426 | * to allocations, but we need to prevent rotation because | |
9427 | * rotate_ctx() will change the list from interrupt context. | |
9428 | */ | |
9429 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9430 | parent_ctx->rotate_disable = 1; | |
9431 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9432 | ||
889ff015 | 9433 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9434 | ret = inherit_task_group(event, parent, parent_ctx, |
9435 | child, ctxn, &inherited_all); | |
889ff015 | 9436 | if (ret) |
9b51f66d | 9437 | break; |
564c2b21 PM |
9438 | } |
9439 | ||
dddd3379 TG |
9440 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9441 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9442 | |
8dc85d54 | 9443 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9444 | |
05cbaa28 | 9445 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9446 | /* |
9447 | * Mark the child context as a clone of the parent | |
9448 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9449 | * |
9450 | * Note that if the parent is a clone, the holding of | |
9451 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9452 | */ |
c5ed5145 | 9453 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9454 | if (cloned_ctx) { |
9455 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9456 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9457 | } else { |
9458 | child_ctx->parent_ctx = parent_ctx; | |
9459 | child_ctx->parent_gen = parent_ctx->generation; | |
9460 | } | |
9461 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9462 | } |
9463 | ||
c5ed5145 | 9464 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9465 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9466 | |
25346b93 | 9467 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9468 | put_ctx(parent_ctx); |
ad3a37de | 9469 | |
6ab423e0 | 9470 | return ret; |
9b51f66d IM |
9471 | } |
9472 | ||
8dc85d54 PZ |
9473 | /* |
9474 | * Initialize the perf_event context in task_struct | |
9475 | */ | |
9476 | int perf_event_init_task(struct task_struct *child) | |
9477 | { | |
9478 | int ctxn, ret; | |
9479 | ||
8550d7cb ON |
9480 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9481 | mutex_init(&child->perf_event_mutex); | |
9482 | INIT_LIST_HEAD(&child->perf_event_list); | |
9483 | ||
8dc85d54 PZ |
9484 | for_each_task_context_nr(ctxn) { |
9485 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9486 | if (ret) { |
9487 | perf_event_free_task(child); | |
8dc85d54 | 9488 | return ret; |
6c72e350 | 9489 | } |
8dc85d54 PZ |
9490 | } |
9491 | ||
9492 | return 0; | |
9493 | } | |
9494 | ||
220b140b PM |
9495 | static void __init perf_event_init_all_cpus(void) |
9496 | { | |
b28ab83c | 9497 | struct swevent_htable *swhash; |
220b140b | 9498 | int cpu; |
220b140b PM |
9499 | |
9500 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9501 | swhash = &per_cpu(swevent_htable, cpu); |
9502 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9503 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9504 | } |
9505 | } | |
9506 | ||
0db0628d | 9507 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9508 | { |
108b02cf | 9509 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9510 | |
b28ab83c | 9511 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 9512 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
9513 | struct swevent_hlist *hlist; |
9514 | ||
b28ab83c PZ |
9515 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9516 | WARN_ON(!hlist); | |
9517 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9518 | } |
b28ab83c | 9519 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9520 | } |
9521 | ||
2965faa5 | 9522 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9523 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9524 | { |
108b02cf | 9525 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9526 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9527 | struct perf_event *event; | |
0793a61d | 9528 | |
fae3fde6 PZ |
9529 | raw_spin_lock(&ctx->lock); |
9530 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9531 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9532 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9533 | } |
108b02cf PZ |
9534 | |
9535 | static void perf_event_exit_cpu_context(int cpu) | |
9536 | { | |
9537 | struct perf_event_context *ctx; | |
9538 | struct pmu *pmu; | |
9539 | int idx; | |
9540 | ||
9541 | idx = srcu_read_lock(&pmus_srcu); | |
9542 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9543 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9544 | |
9545 | mutex_lock(&ctx->mutex); | |
9546 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9547 | mutex_unlock(&ctx->mutex); | |
9548 | } | |
9549 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9550 | } |
9551 | ||
cdd6c482 | 9552 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9553 | { |
e3703f8c | 9554 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9555 | } |
9556 | #else | |
cdd6c482 | 9557 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9558 | #endif |
9559 | ||
c277443c PZ |
9560 | static int |
9561 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9562 | { | |
9563 | int cpu; | |
9564 | ||
9565 | for_each_online_cpu(cpu) | |
9566 | perf_event_exit_cpu(cpu); | |
9567 | ||
9568 | return NOTIFY_OK; | |
9569 | } | |
9570 | ||
9571 | /* | |
9572 | * Run the perf reboot notifier at the very last possible moment so that | |
9573 | * the generic watchdog code runs as long as possible. | |
9574 | */ | |
9575 | static struct notifier_block perf_reboot_notifier = { | |
9576 | .notifier_call = perf_reboot, | |
9577 | .priority = INT_MIN, | |
9578 | }; | |
9579 | ||
0db0628d | 9580 | static int |
0793a61d TG |
9581 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9582 | { | |
9583 | unsigned int cpu = (long)hcpu; | |
9584 | ||
4536e4d1 | 9585 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9586 | |
9587 | case CPU_UP_PREPARE: | |
1dcaac1c PZ |
9588 | /* |
9589 | * This must be done before the CPU comes alive, because the | |
9590 | * moment we can run tasks we can encounter (software) events. | |
9591 | * | |
9592 | * Specifically, someone can have inherited events on kthreadd | |
9593 | * or a pre-existing worker thread that gets re-bound. | |
9594 | */ | |
cdd6c482 | 9595 | perf_event_init_cpu(cpu); |
0793a61d TG |
9596 | break; |
9597 | ||
9598 | case CPU_DOWN_PREPARE: | |
1dcaac1c PZ |
9599 | /* |
9600 | * This must be done before the CPU dies because after that an | |
9601 | * active event might want to IPI the CPU and that'll not work | |
9602 | * so great for dead CPUs. | |
9603 | * | |
9604 | * XXX smp_call_function_single() return -ENXIO without a warn | |
9605 | * so we could possibly deal with this. | |
9606 | * | |
9607 | * This is safe against new events arriving because | |
9608 | * sys_perf_event_open() serializes against hotplug using | |
9609 | * get_online_cpus(). | |
9610 | */ | |
cdd6c482 | 9611 | perf_event_exit_cpu(cpu); |
0793a61d | 9612 | break; |
0793a61d TG |
9613 | default: |
9614 | break; | |
9615 | } | |
9616 | ||
9617 | return NOTIFY_OK; | |
9618 | } | |
9619 | ||
cdd6c482 | 9620 | void __init perf_event_init(void) |
0793a61d | 9621 | { |
3c502e7a JW |
9622 | int ret; |
9623 | ||
2e80a82a PZ |
9624 | idr_init(&pmu_idr); |
9625 | ||
220b140b | 9626 | perf_event_init_all_cpus(); |
b0a873eb | 9627 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9628 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9629 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9630 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9631 | perf_tp_register(); |
9632 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9633 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9634 | |
9635 | ret = init_hw_breakpoint(); | |
9636 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 9637 | |
b01c3a00 JO |
9638 | /* |
9639 | * Build time assertion that we keep the data_head at the intended | |
9640 | * location. IOW, validation we got the __reserved[] size right. | |
9641 | */ | |
9642 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9643 | != 1024); | |
0793a61d | 9644 | } |
abe43400 | 9645 | |
fd979c01 CS |
9646 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9647 | char *page) | |
9648 | { | |
9649 | struct perf_pmu_events_attr *pmu_attr = | |
9650 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9651 | ||
9652 | if (pmu_attr->event_str) | |
9653 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9654 | ||
9655 | return 0; | |
9656 | } | |
675965b0 | 9657 | EXPORT_SYMBOL_GPL(perf_event_sysfs_show); |
fd979c01 | 9658 | |
abe43400 PZ |
9659 | static int __init perf_event_sysfs_init(void) |
9660 | { | |
9661 | struct pmu *pmu; | |
9662 | int ret; | |
9663 | ||
9664 | mutex_lock(&pmus_lock); | |
9665 | ||
9666 | ret = bus_register(&pmu_bus); | |
9667 | if (ret) | |
9668 | goto unlock; | |
9669 | ||
9670 | list_for_each_entry(pmu, &pmus, entry) { | |
9671 | if (!pmu->name || pmu->type < 0) | |
9672 | continue; | |
9673 | ||
9674 | ret = pmu_dev_alloc(pmu); | |
9675 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9676 | } | |
9677 | pmu_bus_running = 1; | |
9678 | ret = 0; | |
9679 | ||
9680 | unlock: | |
9681 | mutex_unlock(&pmus_lock); | |
9682 | ||
9683 | return ret; | |
9684 | } | |
9685 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9686 | |
9687 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9688 | static struct cgroup_subsys_state * |
9689 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9690 | { |
9691 | struct perf_cgroup *jc; | |
e5d1367f | 9692 | |
1b15d055 | 9693 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9694 | if (!jc) |
9695 | return ERR_PTR(-ENOMEM); | |
9696 | ||
e5d1367f SE |
9697 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9698 | if (!jc->info) { | |
9699 | kfree(jc); | |
9700 | return ERR_PTR(-ENOMEM); | |
9701 | } | |
9702 | ||
e5d1367f SE |
9703 | return &jc->css; |
9704 | } | |
9705 | ||
eb95419b | 9706 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9707 | { |
eb95419b TH |
9708 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9709 | ||
e5d1367f SE |
9710 | free_percpu(jc->info); |
9711 | kfree(jc); | |
9712 | } | |
9713 | ||
9714 | static int __perf_cgroup_move(void *info) | |
9715 | { | |
9716 | struct task_struct *task = info; | |
ddaaf4e2 | 9717 | rcu_read_lock(); |
e5d1367f | 9718 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9719 | rcu_read_unlock(); |
e5d1367f SE |
9720 | return 0; |
9721 | } | |
9722 | ||
1f7dd3e5 | 9723 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9724 | { |
bb9d97b6 | 9725 | struct task_struct *task; |
1f7dd3e5 | 9726 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9727 | |
1f7dd3e5 | 9728 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9729 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9730 | } |
9731 | ||
073219e9 | 9732 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9733 | .css_alloc = perf_cgroup_css_alloc, |
9734 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9735 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9736 | }; |
9737 | #endif /* CONFIG_CGROUP_PERF */ |