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1 | /* | |
2 | * Performance events core code: | |
3 | * | |
4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> | |
5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar | |
6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> | |
7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> | |
8 | * | |
9 | * For licensing details see kernel-base/COPYING | |
10 | */ | |
11 | ||
12 | #include <linux/fs.h> | |
13 | #include <linux/mm.h> | |
14 | #include <linux/cpu.h> | |
15 | #include <linux/smp.h> | |
16 | #include <linux/idr.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/poll.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/hash.h> | |
21 | #include <linux/tick.h> | |
22 | #include <linux/sysfs.h> | |
23 | #include <linux/dcache.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/ptrace.h> | |
26 | #include <linux/reboot.h> | |
27 | #include <linux/vmstat.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/export.h> | |
30 | #include <linux/vmalloc.h> | |
31 | #include <linux/hardirq.h> | |
32 | #include <linux/rculist.h> | |
33 | #include <linux/uaccess.h> | |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
36 | #include <linux/kernel_stat.h> | |
37 | #include <linux/perf_event.h> | |
38 | #include <linux/ftrace_event.h> | |
39 | #include <linux/hw_breakpoint.h> | |
40 | #include <linux/mm_types.h> | |
41 | #include <linux/cgroup.h> | |
42 | #include <linux/module.h> | |
43 | #include <linux/mman.h> | |
44 | #include <linux/compat.h> | |
45 | ||
46 | #include "internal.h" | |
47 | ||
48 | #include <asm/irq_regs.h> | |
49 | ||
50 | static struct workqueue_struct *perf_wq; | |
51 | ||
52 | struct remote_function_call { | |
53 | struct task_struct *p; | |
54 | int (*func)(void *info); | |
55 | void *info; | |
56 | int ret; | |
57 | }; | |
58 | ||
59 | static void remote_function(void *data) | |
60 | { | |
61 | struct remote_function_call *tfc = data; | |
62 | struct task_struct *p = tfc->p; | |
63 | ||
64 | if (p) { | |
65 | tfc->ret = -EAGAIN; | |
66 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
67 | return; | |
68 | } | |
69 | ||
70 | tfc->ret = tfc->func(tfc->info); | |
71 | } | |
72 | ||
73 | /** | |
74 | * task_function_call - call a function on the cpu on which a task runs | |
75 | * @p: the task to evaluate | |
76 | * @func: the function to be called | |
77 | * @info: the function call argument | |
78 | * | |
79 | * Calls the function @func when the task is currently running. This might | |
80 | * be on the current CPU, which just calls the function directly | |
81 | * | |
82 | * returns: @func return value, or | |
83 | * -ESRCH - when the process isn't running | |
84 | * -EAGAIN - when the process moved away | |
85 | */ | |
86 | static int | |
87 | task_function_call(struct task_struct *p, int (*func) (void *info), void *info) | |
88 | { | |
89 | struct remote_function_call data = { | |
90 | .p = p, | |
91 | .func = func, | |
92 | .info = info, | |
93 | .ret = -ESRCH, /* No such (running) process */ | |
94 | }; | |
95 | ||
96 | if (task_curr(p)) | |
97 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
98 | ||
99 | return data.ret; | |
100 | } | |
101 | ||
102 | /** | |
103 | * cpu_function_call - call a function on the cpu | |
104 | * @func: the function to be called | |
105 | * @info: the function call argument | |
106 | * | |
107 | * Calls the function @func on the remote cpu. | |
108 | * | |
109 | * returns: @func return value or -ENXIO when the cpu is offline | |
110 | */ | |
111 | static int cpu_function_call(int cpu, int (*func) (void *info), void *info) | |
112 | { | |
113 | struct remote_function_call data = { | |
114 | .p = NULL, | |
115 | .func = func, | |
116 | .info = info, | |
117 | .ret = -ENXIO, /* No such CPU */ | |
118 | }; | |
119 | ||
120 | smp_call_function_single(cpu, remote_function, &data, 1); | |
121 | ||
122 | return data.ret; | |
123 | } | |
124 | ||
125 | #define EVENT_OWNER_KERNEL ((void *) -1) | |
126 | ||
127 | static bool is_kernel_event(struct perf_event *event) | |
128 | { | |
129 | return event->owner == EVENT_OWNER_KERNEL; | |
130 | } | |
131 | ||
132 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ | |
133 | PERF_FLAG_FD_OUTPUT |\ | |
134 | PERF_FLAG_PID_CGROUP |\ | |
135 | PERF_FLAG_FD_CLOEXEC) | |
136 | ||
137 | /* | |
138 | * branch priv levels that need permission checks | |
139 | */ | |
140 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
141 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
142 | PERF_SAMPLE_BRANCH_HV) | |
143 | ||
144 | enum event_type_t { | |
145 | EVENT_FLEXIBLE = 0x1, | |
146 | EVENT_PINNED = 0x2, | |
147 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
148 | }; | |
149 | ||
150 | /* | |
151 | * perf_sched_events : >0 events exist | |
152 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
153 | */ | |
154 | struct static_key_deferred perf_sched_events __read_mostly; | |
155 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); | |
156 | static DEFINE_PER_CPU(atomic_t, perf_branch_stack_events); | |
157 | ||
158 | static atomic_t nr_mmap_events __read_mostly; | |
159 | static atomic_t nr_comm_events __read_mostly; | |
160 | static atomic_t nr_task_events __read_mostly; | |
161 | static atomic_t nr_freq_events __read_mostly; | |
162 | ||
163 | static LIST_HEAD(pmus); | |
164 | static DEFINE_MUTEX(pmus_lock); | |
165 | static struct srcu_struct pmus_srcu; | |
166 | ||
167 | /* | |
168 | * perf event paranoia level: | |
169 | * -1 - not paranoid at all | |
170 | * 0 - disallow raw tracepoint access for unpriv | |
171 | * 1 - disallow cpu events for unpriv | |
172 | * 2 - disallow kernel profiling for unpriv | |
173 | */ | |
174 | int sysctl_perf_event_paranoid __read_mostly = 1; | |
175 | ||
176 | /* Minimum for 512 kiB + 1 user control page */ | |
177 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
178 | ||
179 | /* | |
180 | * max perf event sample rate | |
181 | */ | |
182 | #define DEFAULT_MAX_SAMPLE_RATE 100000 | |
183 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
184 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
185 | ||
186 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
187 | ||
188 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
189 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
190 | ||
191 | static int perf_sample_allowed_ns __read_mostly = | |
192 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
193 | ||
194 | void update_perf_cpu_limits(void) | |
195 | { | |
196 | u64 tmp = perf_sample_period_ns; | |
197 | ||
198 | tmp *= sysctl_perf_cpu_time_max_percent; | |
199 | do_div(tmp, 100); | |
200 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; | |
201 | } | |
202 | ||
203 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); | |
204 | ||
205 | int perf_proc_update_handler(struct ctl_table *table, int write, | |
206 | void __user *buffer, size_t *lenp, | |
207 | loff_t *ppos) | |
208 | { | |
209 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); | |
210 | ||
211 | if (ret || !write) | |
212 | return ret; | |
213 | ||
214 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
215 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
216 | update_perf_cpu_limits(); | |
217 | ||
218 | return 0; | |
219 | } | |
220 | ||
221 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
222 | ||
223 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
224 | void __user *buffer, size_t *lenp, | |
225 | loff_t *ppos) | |
226 | { | |
227 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
228 | ||
229 | if (ret || !write) | |
230 | return ret; | |
231 | ||
232 | update_perf_cpu_limits(); | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | /* | |
238 | * perf samples are done in some very critical code paths (NMIs). | |
239 | * If they take too much CPU time, the system can lock up and not | |
240 | * get any real work done. This will drop the sample rate when | |
241 | * we detect that events are taking too long. | |
242 | */ | |
243 | #define NR_ACCUMULATED_SAMPLES 128 | |
244 | static DEFINE_PER_CPU(u64, running_sample_length); | |
245 | ||
246 | static void perf_duration_warn(struct irq_work *w) | |
247 | { | |
248 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); | |
249 | u64 avg_local_sample_len; | |
250 | u64 local_samples_len; | |
251 | ||
252 | local_samples_len = __this_cpu_read(running_sample_length); | |
253 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
254 | ||
255 | printk_ratelimited(KERN_WARNING | |
256 | "perf interrupt took too long (%lld > %lld), lowering " | |
257 | "kernel.perf_event_max_sample_rate to %d\n", | |
258 | avg_local_sample_len, allowed_ns >> 1, | |
259 | sysctl_perf_event_sample_rate); | |
260 | } | |
261 | ||
262 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
263 | ||
264 | void perf_sample_event_took(u64 sample_len_ns) | |
265 | { | |
266 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); | |
267 | u64 avg_local_sample_len; | |
268 | u64 local_samples_len; | |
269 | ||
270 | if (allowed_ns == 0) | |
271 | return; | |
272 | ||
273 | /* decay the counter by 1 average sample */ | |
274 | local_samples_len = __this_cpu_read(running_sample_length); | |
275 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; | |
276 | local_samples_len += sample_len_ns; | |
277 | __this_cpu_write(running_sample_length, local_samples_len); | |
278 | ||
279 | /* | |
280 | * note: this will be biased artifically low until we have | |
281 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
282 | * from having to maintain a count. | |
283 | */ | |
284 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
285 | ||
286 | if (avg_local_sample_len <= allowed_ns) | |
287 | return; | |
288 | ||
289 | if (max_samples_per_tick <= 1) | |
290 | return; | |
291 | ||
292 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
293 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
294 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
295 | ||
296 | update_perf_cpu_limits(); | |
297 | ||
298 | if (!irq_work_queue(&perf_duration_work)) { | |
299 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
300 | "kernel.perf_event_max_sample_rate to %d\n", | |
301 | avg_local_sample_len, allowed_ns >> 1, | |
302 | sysctl_perf_event_sample_rate); | |
303 | } | |
304 | } | |
305 | ||
306 | static atomic64_t perf_event_id; | |
307 | ||
308 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
309 | enum event_type_t event_type); | |
310 | ||
311 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
312 | enum event_type_t event_type, | |
313 | struct task_struct *task); | |
314 | ||
315 | static void update_context_time(struct perf_event_context *ctx); | |
316 | static u64 perf_event_time(struct perf_event *event); | |
317 | ||
318 | void __weak perf_event_print_debug(void) { } | |
319 | ||
320 | extern __weak const char *perf_pmu_name(void) | |
321 | { | |
322 | return "pmu"; | |
323 | } | |
324 | ||
325 | static inline u64 perf_clock(void) | |
326 | { | |
327 | return local_clock(); | |
328 | } | |
329 | ||
330 | static inline struct perf_cpu_context * | |
331 | __get_cpu_context(struct perf_event_context *ctx) | |
332 | { | |
333 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
334 | } | |
335 | ||
336 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
337 | struct perf_event_context *ctx) | |
338 | { | |
339 | raw_spin_lock(&cpuctx->ctx.lock); | |
340 | if (ctx) | |
341 | raw_spin_lock(&ctx->lock); | |
342 | } | |
343 | ||
344 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
345 | struct perf_event_context *ctx) | |
346 | { | |
347 | if (ctx) | |
348 | raw_spin_unlock(&ctx->lock); | |
349 | raw_spin_unlock(&cpuctx->ctx.lock); | |
350 | } | |
351 | ||
352 | #ifdef CONFIG_CGROUP_PERF | |
353 | ||
354 | /* | |
355 | * perf_cgroup_info keeps track of time_enabled for a cgroup. | |
356 | * This is a per-cpu dynamically allocated data structure. | |
357 | */ | |
358 | struct perf_cgroup_info { | |
359 | u64 time; | |
360 | u64 timestamp; | |
361 | }; | |
362 | ||
363 | struct perf_cgroup { | |
364 | struct cgroup_subsys_state css; | |
365 | struct perf_cgroup_info __percpu *info; | |
366 | }; | |
367 | ||
368 | /* | |
369 | * Must ensure cgroup is pinned (css_get) before calling | |
370 | * this function. In other words, we cannot call this function | |
371 | * if there is no cgroup event for the current CPU context. | |
372 | */ | |
373 | static inline struct perf_cgroup * | |
374 | perf_cgroup_from_task(struct task_struct *task) | |
375 | { | |
376 | return container_of(task_css(task, perf_event_cgrp_id), | |
377 | struct perf_cgroup, css); | |
378 | } | |
379 | ||
380 | static inline bool | |
381 | perf_cgroup_match(struct perf_event *event) | |
382 | { | |
383 | struct perf_event_context *ctx = event->ctx; | |
384 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
385 | ||
386 | /* @event doesn't care about cgroup */ | |
387 | if (!event->cgrp) | |
388 | return true; | |
389 | ||
390 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
391 | if (!cpuctx->cgrp) | |
392 | return false; | |
393 | ||
394 | /* | |
395 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
396 | * also enabled for all its descendant cgroups. If @cpuctx's | |
397 | * cgroup is a descendant of @event's (the test covers identity | |
398 | * case), it's a match. | |
399 | */ | |
400 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
401 | event->cgrp->css.cgroup); | |
402 | } | |
403 | ||
404 | static inline void perf_detach_cgroup(struct perf_event *event) | |
405 | { | |
406 | css_put(&event->cgrp->css); | |
407 | event->cgrp = NULL; | |
408 | } | |
409 | ||
410 | static inline int is_cgroup_event(struct perf_event *event) | |
411 | { | |
412 | return event->cgrp != NULL; | |
413 | } | |
414 | ||
415 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
416 | { | |
417 | struct perf_cgroup_info *t; | |
418 | ||
419 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
420 | return t->time; | |
421 | } | |
422 | ||
423 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
424 | { | |
425 | struct perf_cgroup_info *info; | |
426 | u64 now; | |
427 | ||
428 | now = perf_clock(); | |
429 | ||
430 | info = this_cpu_ptr(cgrp->info); | |
431 | ||
432 | info->time += now - info->timestamp; | |
433 | info->timestamp = now; | |
434 | } | |
435 | ||
436 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
437 | { | |
438 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
439 | if (cgrp_out) | |
440 | __update_cgrp_time(cgrp_out); | |
441 | } | |
442 | ||
443 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
444 | { | |
445 | struct perf_cgroup *cgrp; | |
446 | ||
447 | /* | |
448 | * ensure we access cgroup data only when needed and | |
449 | * when we know the cgroup is pinned (css_get) | |
450 | */ | |
451 | if (!is_cgroup_event(event)) | |
452 | return; | |
453 | ||
454 | cgrp = perf_cgroup_from_task(current); | |
455 | /* | |
456 | * Do not update time when cgroup is not active | |
457 | */ | |
458 | if (cgrp == event->cgrp) | |
459 | __update_cgrp_time(event->cgrp); | |
460 | } | |
461 | ||
462 | static inline void | |
463 | perf_cgroup_set_timestamp(struct task_struct *task, | |
464 | struct perf_event_context *ctx) | |
465 | { | |
466 | struct perf_cgroup *cgrp; | |
467 | struct perf_cgroup_info *info; | |
468 | ||
469 | /* | |
470 | * ctx->lock held by caller | |
471 | * ensure we do not access cgroup data | |
472 | * unless we have the cgroup pinned (css_get) | |
473 | */ | |
474 | if (!task || !ctx->nr_cgroups) | |
475 | return; | |
476 | ||
477 | cgrp = perf_cgroup_from_task(task); | |
478 | info = this_cpu_ptr(cgrp->info); | |
479 | info->timestamp = ctx->timestamp; | |
480 | } | |
481 | ||
482 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
483 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
484 | ||
485 | /* | |
486 | * reschedule events based on the cgroup constraint of task. | |
487 | * | |
488 | * mode SWOUT : schedule out everything | |
489 | * mode SWIN : schedule in based on cgroup for next | |
490 | */ | |
491 | void perf_cgroup_switch(struct task_struct *task, int mode) | |
492 | { | |
493 | struct perf_cpu_context *cpuctx; | |
494 | struct pmu *pmu; | |
495 | unsigned long flags; | |
496 | ||
497 | /* | |
498 | * disable interrupts to avoid geting nr_cgroup | |
499 | * changes via __perf_event_disable(). Also | |
500 | * avoids preemption. | |
501 | */ | |
502 | local_irq_save(flags); | |
503 | ||
504 | /* | |
505 | * we reschedule only in the presence of cgroup | |
506 | * constrained events. | |
507 | */ | |
508 | rcu_read_lock(); | |
509 | ||
510 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
511 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
512 | if (cpuctx->unique_pmu != pmu) | |
513 | continue; /* ensure we process each cpuctx once */ | |
514 | ||
515 | /* | |
516 | * perf_cgroup_events says at least one | |
517 | * context on this CPU has cgroup events. | |
518 | * | |
519 | * ctx->nr_cgroups reports the number of cgroup | |
520 | * events for a context. | |
521 | */ | |
522 | if (cpuctx->ctx.nr_cgroups > 0) { | |
523 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
524 | perf_pmu_disable(cpuctx->ctx.pmu); | |
525 | ||
526 | if (mode & PERF_CGROUP_SWOUT) { | |
527 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
528 | /* | |
529 | * must not be done before ctxswout due | |
530 | * to event_filter_match() in event_sched_out() | |
531 | */ | |
532 | cpuctx->cgrp = NULL; | |
533 | } | |
534 | ||
535 | if (mode & PERF_CGROUP_SWIN) { | |
536 | WARN_ON_ONCE(cpuctx->cgrp); | |
537 | /* | |
538 | * set cgrp before ctxsw in to allow | |
539 | * event_filter_match() to not have to pass | |
540 | * task around | |
541 | */ | |
542 | cpuctx->cgrp = perf_cgroup_from_task(task); | |
543 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); | |
544 | } | |
545 | perf_pmu_enable(cpuctx->ctx.pmu); | |
546 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
547 | } | |
548 | } | |
549 | ||
550 | rcu_read_unlock(); | |
551 | ||
552 | local_irq_restore(flags); | |
553 | } | |
554 | ||
555 | static inline void perf_cgroup_sched_out(struct task_struct *task, | |
556 | struct task_struct *next) | |
557 | { | |
558 | struct perf_cgroup *cgrp1; | |
559 | struct perf_cgroup *cgrp2 = NULL; | |
560 | ||
561 | /* | |
562 | * we come here when we know perf_cgroup_events > 0 | |
563 | */ | |
564 | cgrp1 = perf_cgroup_from_task(task); | |
565 | ||
566 | /* | |
567 | * next is NULL when called from perf_event_enable_on_exec() | |
568 | * that will systematically cause a cgroup_switch() | |
569 | */ | |
570 | if (next) | |
571 | cgrp2 = perf_cgroup_from_task(next); | |
572 | ||
573 | /* | |
574 | * only schedule out current cgroup events if we know | |
575 | * that we are switching to a different cgroup. Otherwise, | |
576 | * do no touch the cgroup events. | |
577 | */ | |
578 | if (cgrp1 != cgrp2) | |
579 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
580 | } | |
581 | ||
582 | static inline void perf_cgroup_sched_in(struct task_struct *prev, | |
583 | struct task_struct *task) | |
584 | { | |
585 | struct perf_cgroup *cgrp1; | |
586 | struct perf_cgroup *cgrp2 = NULL; | |
587 | ||
588 | /* | |
589 | * we come here when we know perf_cgroup_events > 0 | |
590 | */ | |
591 | cgrp1 = perf_cgroup_from_task(task); | |
592 | ||
593 | /* prev can never be NULL */ | |
594 | cgrp2 = perf_cgroup_from_task(prev); | |
595 | ||
596 | /* | |
597 | * only need to schedule in cgroup events if we are changing | |
598 | * cgroup during ctxsw. Cgroup events were not scheduled | |
599 | * out of ctxsw out if that was not the case. | |
600 | */ | |
601 | if (cgrp1 != cgrp2) | |
602 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
603 | } | |
604 | ||
605 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
606 | struct perf_event_attr *attr, | |
607 | struct perf_event *group_leader) | |
608 | { | |
609 | struct perf_cgroup *cgrp; | |
610 | struct cgroup_subsys_state *css; | |
611 | struct fd f = fdget(fd); | |
612 | int ret = 0; | |
613 | ||
614 | if (!f.file) | |
615 | return -EBADF; | |
616 | ||
617 | css = css_tryget_online_from_dir(f.file->f_path.dentry, | |
618 | &perf_event_cgrp_subsys); | |
619 | if (IS_ERR(css)) { | |
620 | ret = PTR_ERR(css); | |
621 | goto out; | |
622 | } | |
623 | ||
624 | cgrp = container_of(css, struct perf_cgroup, css); | |
625 | event->cgrp = cgrp; | |
626 | ||
627 | /* | |
628 | * all events in a group must monitor | |
629 | * the same cgroup because a task belongs | |
630 | * to only one perf cgroup at a time | |
631 | */ | |
632 | if (group_leader && group_leader->cgrp != cgrp) { | |
633 | perf_detach_cgroup(event); | |
634 | ret = -EINVAL; | |
635 | } | |
636 | out: | |
637 | fdput(f); | |
638 | return ret; | |
639 | } | |
640 | ||
641 | static inline void | |
642 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
643 | { | |
644 | struct perf_cgroup_info *t; | |
645 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
646 | event->shadow_ctx_time = now - t->timestamp; | |
647 | } | |
648 | ||
649 | static inline void | |
650 | perf_cgroup_defer_enabled(struct perf_event *event) | |
651 | { | |
652 | /* | |
653 | * when the current task's perf cgroup does not match | |
654 | * the event's, we need to remember to call the | |
655 | * perf_mark_enable() function the first time a task with | |
656 | * a matching perf cgroup is scheduled in. | |
657 | */ | |
658 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
659 | event->cgrp_defer_enabled = 1; | |
660 | } | |
661 | ||
662 | static inline void | |
663 | perf_cgroup_mark_enabled(struct perf_event *event, | |
664 | struct perf_event_context *ctx) | |
665 | { | |
666 | struct perf_event *sub; | |
667 | u64 tstamp = perf_event_time(event); | |
668 | ||
669 | if (!event->cgrp_defer_enabled) | |
670 | return; | |
671 | ||
672 | event->cgrp_defer_enabled = 0; | |
673 | ||
674 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
675 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
676 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
677 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
678 | sub->cgrp_defer_enabled = 0; | |
679 | } | |
680 | } | |
681 | } | |
682 | #else /* !CONFIG_CGROUP_PERF */ | |
683 | ||
684 | static inline bool | |
685 | perf_cgroup_match(struct perf_event *event) | |
686 | { | |
687 | return true; | |
688 | } | |
689 | ||
690 | static inline void perf_detach_cgroup(struct perf_event *event) | |
691 | {} | |
692 | ||
693 | static inline int is_cgroup_event(struct perf_event *event) | |
694 | { | |
695 | return 0; | |
696 | } | |
697 | ||
698 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
699 | { | |
700 | return 0; | |
701 | } | |
702 | ||
703 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
704 | { | |
705 | } | |
706 | ||
707 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
708 | { | |
709 | } | |
710 | ||
711 | static inline void perf_cgroup_sched_out(struct task_struct *task, | |
712 | struct task_struct *next) | |
713 | { | |
714 | } | |
715 | ||
716 | static inline void perf_cgroup_sched_in(struct task_struct *prev, | |
717 | struct task_struct *task) | |
718 | { | |
719 | } | |
720 | ||
721 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
722 | struct perf_event_attr *attr, | |
723 | struct perf_event *group_leader) | |
724 | { | |
725 | return -EINVAL; | |
726 | } | |
727 | ||
728 | static inline void | |
729 | perf_cgroup_set_timestamp(struct task_struct *task, | |
730 | struct perf_event_context *ctx) | |
731 | { | |
732 | } | |
733 | ||
734 | void | |
735 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
736 | { | |
737 | } | |
738 | ||
739 | static inline void | |
740 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
741 | { | |
742 | } | |
743 | ||
744 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
745 | { | |
746 | return 0; | |
747 | } | |
748 | ||
749 | static inline void | |
750 | perf_cgroup_defer_enabled(struct perf_event *event) | |
751 | { | |
752 | } | |
753 | ||
754 | static inline void | |
755 | perf_cgroup_mark_enabled(struct perf_event *event, | |
756 | struct perf_event_context *ctx) | |
757 | { | |
758 | } | |
759 | #endif | |
760 | ||
761 | /* | |
762 | * set default to be dependent on timer tick just | |
763 | * like original code | |
764 | */ | |
765 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
766 | /* | |
767 | * function must be called with interrupts disbled | |
768 | */ | |
769 | static enum hrtimer_restart perf_cpu_hrtimer_handler(struct hrtimer *hr) | |
770 | { | |
771 | struct perf_cpu_context *cpuctx; | |
772 | enum hrtimer_restart ret = HRTIMER_NORESTART; | |
773 | int rotations = 0; | |
774 | ||
775 | WARN_ON(!irqs_disabled()); | |
776 | ||
777 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
778 | ||
779 | rotations = perf_rotate_context(cpuctx); | |
780 | ||
781 | /* | |
782 | * arm timer if needed | |
783 | */ | |
784 | if (rotations) { | |
785 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); | |
786 | ret = HRTIMER_RESTART; | |
787 | } | |
788 | ||
789 | return ret; | |
790 | } | |
791 | ||
792 | /* CPU is going down */ | |
793 | void perf_cpu_hrtimer_cancel(int cpu) | |
794 | { | |
795 | struct perf_cpu_context *cpuctx; | |
796 | struct pmu *pmu; | |
797 | unsigned long flags; | |
798 | ||
799 | if (WARN_ON(cpu != smp_processor_id())) | |
800 | return; | |
801 | ||
802 | local_irq_save(flags); | |
803 | ||
804 | rcu_read_lock(); | |
805 | ||
806 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
807 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
808 | ||
809 | if (pmu->task_ctx_nr == perf_sw_context) | |
810 | continue; | |
811 | ||
812 | hrtimer_cancel(&cpuctx->hrtimer); | |
813 | } | |
814 | ||
815 | rcu_read_unlock(); | |
816 | ||
817 | local_irq_restore(flags); | |
818 | } | |
819 | ||
820 | static void __perf_cpu_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) | |
821 | { | |
822 | struct hrtimer *hr = &cpuctx->hrtimer; | |
823 | struct pmu *pmu = cpuctx->ctx.pmu; | |
824 | int timer; | |
825 | ||
826 | /* no multiplexing needed for SW PMU */ | |
827 | if (pmu->task_ctx_nr == perf_sw_context) | |
828 | return; | |
829 | ||
830 | /* | |
831 | * check default is sane, if not set then force to | |
832 | * default interval (1/tick) | |
833 | */ | |
834 | timer = pmu->hrtimer_interval_ms; | |
835 | if (timer < 1) | |
836 | timer = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
837 | ||
838 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
839 | ||
840 | hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED); | |
841 | hr->function = perf_cpu_hrtimer_handler; | |
842 | } | |
843 | ||
844 | static void perf_cpu_hrtimer_restart(struct perf_cpu_context *cpuctx) | |
845 | { | |
846 | struct hrtimer *hr = &cpuctx->hrtimer; | |
847 | struct pmu *pmu = cpuctx->ctx.pmu; | |
848 | ||
849 | /* not for SW PMU */ | |
850 | if (pmu->task_ctx_nr == perf_sw_context) | |
851 | return; | |
852 | ||
853 | if (hrtimer_active(hr)) | |
854 | return; | |
855 | ||
856 | if (!hrtimer_callback_running(hr)) | |
857 | __hrtimer_start_range_ns(hr, cpuctx->hrtimer_interval, | |
858 | 0, HRTIMER_MODE_REL_PINNED, 0); | |
859 | } | |
860 | ||
861 | void perf_pmu_disable(struct pmu *pmu) | |
862 | { | |
863 | int *count = this_cpu_ptr(pmu->pmu_disable_count); | |
864 | if (!(*count)++) | |
865 | pmu->pmu_disable(pmu); | |
866 | } | |
867 | ||
868 | void perf_pmu_enable(struct pmu *pmu) | |
869 | { | |
870 | int *count = this_cpu_ptr(pmu->pmu_disable_count); | |
871 | if (!--(*count)) | |
872 | pmu->pmu_enable(pmu); | |
873 | } | |
874 | ||
875 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); | |
876 | ||
877 | /* | |
878 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and | |
879 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
880 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
881 | * disabled, while perf_event_task_tick is called from IRQ context. | |
882 | */ | |
883 | static void perf_event_ctx_activate(struct perf_event_context *ctx) | |
884 | { | |
885 | struct list_head *head = this_cpu_ptr(&active_ctx_list); | |
886 | ||
887 | WARN_ON(!irqs_disabled()); | |
888 | ||
889 | WARN_ON(!list_empty(&ctx->active_ctx_list)); | |
890 | ||
891 | list_add(&ctx->active_ctx_list, head); | |
892 | } | |
893 | ||
894 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
895 | { | |
896 | WARN_ON(!irqs_disabled()); | |
897 | ||
898 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
899 | ||
900 | list_del_init(&ctx->active_ctx_list); | |
901 | } | |
902 | ||
903 | static void get_ctx(struct perf_event_context *ctx) | |
904 | { | |
905 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); | |
906 | } | |
907 | ||
908 | static void put_ctx(struct perf_event_context *ctx) | |
909 | { | |
910 | if (atomic_dec_and_test(&ctx->refcount)) { | |
911 | if (ctx->parent_ctx) | |
912 | put_ctx(ctx->parent_ctx); | |
913 | if (ctx->task) | |
914 | put_task_struct(ctx->task); | |
915 | kfree_rcu(ctx, rcu_head); | |
916 | } | |
917 | } | |
918 | ||
919 | /* | |
920 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
921 | * perf_pmu_migrate_context() we need some magic. | |
922 | * | |
923 | * Those places that change perf_event::ctx will hold both | |
924 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
925 | * | |
926 | * Lock ordering is by mutex address. There is one other site where | |
927 | * perf_event_context::mutex nests and that is put_event(). But remember that | |
928 | * that is a parent<->child context relation, and migration does not affect | |
929 | * children, therefore these two orderings should not interact. | |
930 | * | |
931 | * The change in perf_event::ctx does not affect children (as claimed above) | |
932 | * because the sys_perf_event_open() case will install a new event and break | |
933 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
934 | * concerned with cpuctx and that doesn't have children. | |
935 | * | |
936 | * The places that change perf_event::ctx will issue: | |
937 | * | |
938 | * perf_remove_from_context(); | |
939 | * synchronize_rcu(); | |
940 | * perf_install_in_context(); | |
941 | * | |
942 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
943 | * quiesce the event, after which we can install it in the new location. This | |
944 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
945 | * while in transit. Therefore all such accessors should also acquire | |
946 | * perf_event_context::mutex to serialize against this. | |
947 | * | |
948 | * However; because event->ctx can change while we're waiting to acquire | |
949 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
950 | * function. | |
951 | * | |
952 | * Lock order: | |
953 | * task_struct::perf_event_mutex | |
954 | * perf_event_context::mutex | |
955 | * perf_event_context::lock | |
956 | * perf_event::child_mutex; | |
957 | * perf_event::mmap_mutex | |
958 | * mmap_sem | |
959 | */ | |
960 | static struct perf_event_context * | |
961 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
962 | { | |
963 | struct perf_event_context *ctx; | |
964 | ||
965 | again: | |
966 | rcu_read_lock(); | |
967 | ctx = ACCESS_ONCE(event->ctx); | |
968 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
969 | rcu_read_unlock(); | |
970 | goto again; | |
971 | } | |
972 | rcu_read_unlock(); | |
973 | ||
974 | mutex_lock_nested(&ctx->mutex, nesting); | |
975 | if (event->ctx != ctx) { | |
976 | mutex_unlock(&ctx->mutex); | |
977 | put_ctx(ctx); | |
978 | goto again; | |
979 | } | |
980 | ||
981 | return ctx; | |
982 | } | |
983 | ||
984 | static inline struct perf_event_context * | |
985 | perf_event_ctx_lock(struct perf_event *event) | |
986 | { | |
987 | return perf_event_ctx_lock_nested(event, 0); | |
988 | } | |
989 | ||
990 | static void perf_event_ctx_unlock(struct perf_event *event, | |
991 | struct perf_event_context *ctx) | |
992 | { | |
993 | mutex_unlock(&ctx->mutex); | |
994 | put_ctx(ctx); | |
995 | } | |
996 | ||
997 | /* | |
998 | * This must be done under the ctx->lock, such as to serialize against | |
999 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1000 | * calling scheduler related locks and ctx->lock nests inside those. | |
1001 | */ | |
1002 | static __must_check struct perf_event_context * | |
1003 | unclone_ctx(struct perf_event_context *ctx) | |
1004 | { | |
1005 | struct perf_event_context *parent_ctx = ctx->parent_ctx; | |
1006 | ||
1007 | lockdep_assert_held(&ctx->lock); | |
1008 | ||
1009 | if (parent_ctx) | |
1010 | ctx->parent_ctx = NULL; | |
1011 | ctx->generation++; | |
1012 | ||
1013 | return parent_ctx; | |
1014 | } | |
1015 | ||
1016 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) | |
1017 | { | |
1018 | /* | |
1019 | * only top level events have the pid namespace they were created in | |
1020 | */ | |
1021 | if (event->parent) | |
1022 | event = event->parent; | |
1023 | ||
1024 | return task_tgid_nr_ns(p, event->ns); | |
1025 | } | |
1026 | ||
1027 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1028 | { | |
1029 | /* | |
1030 | * only top level events have the pid namespace they were created in | |
1031 | */ | |
1032 | if (event->parent) | |
1033 | event = event->parent; | |
1034 | ||
1035 | return task_pid_nr_ns(p, event->ns); | |
1036 | } | |
1037 | ||
1038 | /* | |
1039 | * If we inherit events we want to return the parent event id | |
1040 | * to userspace. | |
1041 | */ | |
1042 | static u64 primary_event_id(struct perf_event *event) | |
1043 | { | |
1044 | u64 id = event->id; | |
1045 | ||
1046 | if (event->parent) | |
1047 | id = event->parent->id; | |
1048 | ||
1049 | return id; | |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * Get the perf_event_context for a task and lock it. | |
1054 | * This has to cope with with the fact that until it is locked, | |
1055 | * the context could get moved to another task. | |
1056 | */ | |
1057 | static struct perf_event_context * | |
1058 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) | |
1059 | { | |
1060 | struct perf_event_context *ctx; | |
1061 | ||
1062 | retry: | |
1063 | /* | |
1064 | * One of the few rules of preemptible RCU is that one cannot do | |
1065 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
1066 | * part of the read side critical section was preemptible -- see | |
1067 | * rcu_read_unlock_special(). | |
1068 | * | |
1069 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
1070 | * side critical section is non-preemptible. | |
1071 | */ | |
1072 | preempt_disable(); | |
1073 | rcu_read_lock(); | |
1074 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); | |
1075 | if (ctx) { | |
1076 | /* | |
1077 | * If this context is a clone of another, it might | |
1078 | * get swapped for another underneath us by | |
1079 | * perf_event_task_sched_out, though the | |
1080 | * rcu_read_lock() protects us from any context | |
1081 | * getting freed. Lock the context and check if it | |
1082 | * got swapped before we could get the lock, and retry | |
1083 | * if so. If we locked the right context, then it | |
1084 | * can't get swapped on us any more. | |
1085 | */ | |
1086 | raw_spin_lock_irqsave(&ctx->lock, *flags); | |
1087 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { | |
1088 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); | |
1089 | rcu_read_unlock(); | |
1090 | preempt_enable(); | |
1091 | goto retry; | |
1092 | } | |
1093 | ||
1094 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1095 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); | |
1096 | ctx = NULL; | |
1097 | } | |
1098 | } | |
1099 | rcu_read_unlock(); | |
1100 | preempt_enable(); | |
1101 | return ctx; | |
1102 | } | |
1103 | ||
1104 | /* | |
1105 | * Get the context for a task and increment its pin_count so it | |
1106 | * can't get swapped to another task. This also increments its | |
1107 | * reference count so that the context can't get freed. | |
1108 | */ | |
1109 | static struct perf_event_context * | |
1110 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
1111 | { | |
1112 | struct perf_event_context *ctx; | |
1113 | unsigned long flags; | |
1114 | ||
1115 | ctx = perf_lock_task_context(task, ctxn, &flags); | |
1116 | if (ctx) { | |
1117 | ++ctx->pin_count; | |
1118 | raw_spin_unlock_irqrestore(&ctx->lock, flags); | |
1119 | } | |
1120 | return ctx; | |
1121 | } | |
1122 | ||
1123 | static void perf_unpin_context(struct perf_event_context *ctx) | |
1124 | { | |
1125 | unsigned long flags; | |
1126 | ||
1127 | raw_spin_lock_irqsave(&ctx->lock, flags); | |
1128 | --ctx->pin_count; | |
1129 | raw_spin_unlock_irqrestore(&ctx->lock, flags); | |
1130 | } | |
1131 | ||
1132 | /* | |
1133 | * Update the record of the current time in a context. | |
1134 | */ | |
1135 | static void update_context_time(struct perf_event_context *ctx) | |
1136 | { | |
1137 | u64 now = perf_clock(); | |
1138 | ||
1139 | ctx->time += now - ctx->timestamp; | |
1140 | ctx->timestamp = now; | |
1141 | } | |
1142 | ||
1143 | static u64 perf_event_time(struct perf_event *event) | |
1144 | { | |
1145 | struct perf_event_context *ctx = event->ctx; | |
1146 | ||
1147 | if (is_cgroup_event(event)) | |
1148 | return perf_cgroup_event_time(event); | |
1149 | ||
1150 | return ctx ? ctx->time : 0; | |
1151 | } | |
1152 | ||
1153 | /* | |
1154 | * Update the total_time_enabled and total_time_running fields for a event. | |
1155 | * The caller of this function needs to hold the ctx->lock. | |
1156 | */ | |
1157 | static void update_event_times(struct perf_event *event) | |
1158 | { | |
1159 | struct perf_event_context *ctx = event->ctx; | |
1160 | u64 run_end; | |
1161 | ||
1162 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1163 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1164 | return; | |
1165 | /* | |
1166 | * in cgroup mode, time_enabled represents | |
1167 | * the time the event was enabled AND active | |
1168 | * tasks were in the monitored cgroup. This is | |
1169 | * independent of the activity of the context as | |
1170 | * there may be a mix of cgroup and non-cgroup events. | |
1171 | * | |
1172 | * That is why we treat cgroup events differently | |
1173 | * here. | |
1174 | */ | |
1175 | if (is_cgroup_event(event)) | |
1176 | run_end = perf_cgroup_event_time(event); | |
1177 | else if (ctx->is_active) | |
1178 | run_end = ctx->time; | |
1179 | else | |
1180 | run_end = event->tstamp_stopped; | |
1181 | ||
1182 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
1183 | ||
1184 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1185 | run_end = event->tstamp_stopped; | |
1186 | else | |
1187 | run_end = perf_event_time(event); | |
1188 | ||
1189 | event->total_time_running = run_end - event->tstamp_running; | |
1190 | ||
1191 | } | |
1192 | ||
1193 | /* | |
1194 | * Update total_time_enabled and total_time_running for all events in a group. | |
1195 | */ | |
1196 | static void update_group_times(struct perf_event *leader) | |
1197 | { | |
1198 | struct perf_event *event; | |
1199 | ||
1200 | update_event_times(leader); | |
1201 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1202 | update_event_times(event); | |
1203 | } | |
1204 | ||
1205 | static struct list_head * | |
1206 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1207 | { | |
1208 | if (event->attr.pinned) | |
1209 | return &ctx->pinned_groups; | |
1210 | else | |
1211 | return &ctx->flexible_groups; | |
1212 | } | |
1213 | ||
1214 | /* | |
1215 | * Add a event from the lists for its context. | |
1216 | * Must be called with ctx->mutex and ctx->lock held. | |
1217 | */ | |
1218 | static void | |
1219 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) | |
1220 | { | |
1221 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); | |
1222 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
1223 | ||
1224 | /* | |
1225 | * If we're a stand alone event or group leader, we go to the context | |
1226 | * list, group events are kept attached to the group so that | |
1227 | * perf_group_detach can, at all times, locate all siblings. | |
1228 | */ | |
1229 | if (event->group_leader == event) { | |
1230 | struct list_head *list; | |
1231 | ||
1232 | if (is_software_event(event)) | |
1233 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1234 | ||
1235 | list = ctx_group_list(event, ctx); | |
1236 | list_add_tail(&event->group_entry, list); | |
1237 | } | |
1238 | ||
1239 | if (is_cgroup_event(event)) | |
1240 | ctx->nr_cgroups++; | |
1241 | ||
1242 | if (has_branch_stack(event)) | |
1243 | ctx->nr_branch_stack++; | |
1244 | ||
1245 | list_add_rcu(&event->event_entry, &ctx->event_list); | |
1246 | ctx->nr_events++; | |
1247 | if (event->attr.inherit_stat) | |
1248 | ctx->nr_stat++; | |
1249 | ||
1250 | ctx->generation++; | |
1251 | } | |
1252 | ||
1253 | /* | |
1254 | * Initialize event state based on the perf_event_attr::disabled. | |
1255 | */ | |
1256 | static inline void perf_event__state_init(struct perf_event *event) | |
1257 | { | |
1258 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1259 | PERF_EVENT_STATE_INACTIVE; | |
1260 | } | |
1261 | ||
1262 | /* | |
1263 | * Called at perf_event creation and when events are attached/detached from a | |
1264 | * group. | |
1265 | */ | |
1266 | static void perf_event__read_size(struct perf_event *event) | |
1267 | { | |
1268 | int entry = sizeof(u64); /* value */ | |
1269 | int size = 0; | |
1270 | int nr = 1; | |
1271 | ||
1272 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1273 | size += sizeof(u64); | |
1274 | ||
1275 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1276 | size += sizeof(u64); | |
1277 | ||
1278 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1279 | entry += sizeof(u64); | |
1280 | ||
1281 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
1282 | nr += event->group_leader->nr_siblings; | |
1283 | size += sizeof(u64); | |
1284 | } | |
1285 | ||
1286 | size += entry * nr; | |
1287 | event->read_size = size; | |
1288 | } | |
1289 | ||
1290 | static void perf_event__header_size(struct perf_event *event) | |
1291 | { | |
1292 | struct perf_sample_data *data; | |
1293 | u64 sample_type = event->attr.sample_type; | |
1294 | u16 size = 0; | |
1295 | ||
1296 | perf_event__read_size(event); | |
1297 | ||
1298 | if (sample_type & PERF_SAMPLE_IP) | |
1299 | size += sizeof(data->ip); | |
1300 | ||
1301 | if (sample_type & PERF_SAMPLE_ADDR) | |
1302 | size += sizeof(data->addr); | |
1303 | ||
1304 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1305 | size += sizeof(data->period); | |
1306 | ||
1307 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
1308 | size += sizeof(data->weight); | |
1309 | ||
1310 | if (sample_type & PERF_SAMPLE_READ) | |
1311 | size += event->read_size; | |
1312 | ||
1313 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
1314 | size += sizeof(data->data_src.val); | |
1315 | ||
1316 | if (sample_type & PERF_SAMPLE_TRANSACTION) | |
1317 | size += sizeof(data->txn); | |
1318 | ||
1319 | event->header_size = size; | |
1320 | } | |
1321 | ||
1322 | static void perf_event__id_header_size(struct perf_event *event) | |
1323 | { | |
1324 | struct perf_sample_data *data; | |
1325 | u64 sample_type = event->attr.sample_type; | |
1326 | u16 size = 0; | |
1327 | ||
1328 | if (sample_type & PERF_SAMPLE_TID) | |
1329 | size += sizeof(data->tid_entry); | |
1330 | ||
1331 | if (sample_type & PERF_SAMPLE_TIME) | |
1332 | size += sizeof(data->time); | |
1333 | ||
1334 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
1335 | size += sizeof(data->id); | |
1336 | ||
1337 | if (sample_type & PERF_SAMPLE_ID) | |
1338 | size += sizeof(data->id); | |
1339 | ||
1340 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1341 | size += sizeof(data->stream_id); | |
1342 | ||
1343 | if (sample_type & PERF_SAMPLE_CPU) | |
1344 | size += sizeof(data->cpu_entry); | |
1345 | ||
1346 | event->id_header_size = size; | |
1347 | } | |
1348 | ||
1349 | static void perf_group_attach(struct perf_event *event) | |
1350 | { | |
1351 | struct perf_event *group_leader = event->group_leader, *pos; | |
1352 | ||
1353 | /* | |
1354 | * We can have double attach due to group movement in perf_event_open. | |
1355 | */ | |
1356 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1357 | return; | |
1358 | ||
1359 | event->attach_state |= PERF_ATTACH_GROUP; | |
1360 | ||
1361 | if (group_leader == event) | |
1362 | return; | |
1363 | ||
1364 | WARN_ON_ONCE(group_leader->ctx != event->ctx); | |
1365 | ||
1366 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && | |
1367 | !is_software_event(event)) | |
1368 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1369 | ||
1370 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1371 | group_leader->nr_siblings++; | |
1372 | ||
1373 | perf_event__header_size(group_leader); | |
1374 | ||
1375 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1376 | perf_event__header_size(pos); | |
1377 | } | |
1378 | ||
1379 | /* | |
1380 | * Remove a event from the lists for its context. | |
1381 | * Must be called with ctx->mutex and ctx->lock held. | |
1382 | */ | |
1383 | static void | |
1384 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) | |
1385 | { | |
1386 | struct perf_cpu_context *cpuctx; | |
1387 | ||
1388 | WARN_ON_ONCE(event->ctx != ctx); | |
1389 | lockdep_assert_held(&ctx->lock); | |
1390 | ||
1391 | /* | |
1392 | * We can have double detach due to exit/hot-unplug + close. | |
1393 | */ | |
1394 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
1395 | return; | |
1396 | ||
1397 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1398 | ||
1399 | if (is_cgroup_event(event)) { | |
1400 | ctx->nr_cgroups--; | |
1401 | cpuctx = __get_cpu_context(ctx); | |
1402 | /* | |
1403 | * if there are no more cgroup events | |
1404 | * then cler cgrp to avoid stale pointer | |
1405 | * in update_cgrp_time_from_cpuctx() | |
1406 | */ | |
1407 | if (!ctx->nr_cgroups) | |
1408 | cpuctx->cgrp = NULL; | |
1409 | } | |
1410 | ||
1411 | if (has_branch_stack(event)) | |
1412 | ctx->nr_branch_stack--; | |
1413 | ||
1414 | ctx->nr_events--; | |
1415 | if (event->attr.inherit_stat) | |
1416 | ctx->nr_stat--; | |
1417 | ||
1418 | list_del_rcu(&event->event_entry); | |
1419 | ||
1420 | if (event->group_leader == event) | |
1421 | list_del_init(&event->group_entry); | |
1422 | ||
1423 | update_group_times(event); | |
1424 | ||
1425 | /* | |
1426 | * If event was in error state, then keep it | |
1427 | * that way, otherwise bogus counts will be | |
1428 | * returned on read(). The only way to get out | |
1429 | * of error state is by explicit re-enabling | |
1430 | * of the event | |
1431 | */ | |
1432 | if (event->state > PERF_EVENT_STATE_OFF) | |
1433 | event->state = PERF_EVENT_STATE_OFF; | |
1434 | ||
1435 | ctx->generation++; | |
1436 | } | |
1437 | ||
1438 | static void perf_group_detach(struct perf_event *event) | |
1439 | { | |
1440 | struct perf_event *sibling, *tmp; | |
1441 | struct list_head *list = NULL; | |
1442 | ||
1443 | /* | |
1444 | * We can have double detach due to exit/hot-unplug + close. | |
1445 | */ | |
1446 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1447 | return; | |
1448 | ||
1449 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1450 | ||
1451 | /* | |
1452 | * If this is a sibling, remove it from its group. | |
1453 | */ | |
1454 | if (event->group_leader != event) { | |
1455 | list_del_init(&event->group_entry); | |
1456 | event->group_leader->nr_siblings--; | |
1457 | goto out; | |
1458 | } | |
1459 | ||
1460 | if (!list_empty(&event->group_entry)) | |
1461 | list = &event->group_entry; | |
1462 | ||
1463 | /* | |
1464 | * If this was a group event with sibling events then | |
1465 | * upgrade the siblings to singleton events by adding them | |
1466 | * to whatever list we are on. | |
1467 | */ | |
1468 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { | |
1469 | if (list) | |
1470 | list_move_tail(&sibling->group_entry, list); | |
1471 | sibling->group_leader = sibling; | |
1472 | ||
1473 | /* Inherit group flags from the previous leader */ | |
1474 | sibling->group_flags = event->group_flags; | |
1475 | ||
1476 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
1477 | } | |
1478 | ||
1479 | out: | |
1480 | perf_event__header_size(event->group_leader); | |
1481 | ||
1482 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1483 | perf_event__header_size(tmp); | |
1484 | } | |
1485 | ||
1486 | /* | |
1487 | * User event without the task. | |
1488 | */ | |
1489 | static bool is_orphaned_event(struct perf_event *event) | |
1490 | { | |
1491 | return event && !is_kernel_event(event) && !event->owner; | |
1492 | } | |
1493 | ||
1494 | /* | |
1495 | * Event has a parent but parent's task finished and it's | |
1496 | * alive only because of children holding refference. | |
1497 | */ | |
1498 | static bool is_orphaned_child(struct perf_event *event) | |
1499 | { | |
1500 | return is_orphaned_event(event->parent); | |
1501 | } | |
1502 | ||
1503 | static void orphans_remove_work(struct work_struct *work); | |
1504 | ||
1505 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1506 | { | |
1507 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1508 | return; | |
1509 | ||
1510 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1511 | get_ctx(ctx); | |
1512 | ctx->orphans_remove_sched = true; | |
1513 | } | |
1514 | } | |
1515 | ||
1516 | static int __init perf_workqueue_init(void) | |
1517 | { | |
1518 | perf_wq = create_singlethread_workqueue("perf"); | |
1519 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1520 | return perf_wq ? 0 : -1; | |
1521 | } | |
1522 | ||
1523 | core_initcall(perf_workqueue_init); | |
1524 | ||
1525 | static inline int | |
1526 | event_filter_match(struct perf_event *event) | |
1527 | { | |
1528 | return (event->cpu == -1 || event->cpu == smp_processor_id()) | |
1529 | && perf_cgroup_match(event); | |
1530 | } | |
1531 | ||
1532 | static void | |
1533 | event_sched_out(struct perf_event *event, | |
1534 | struct perf_cpu_context *cpuctx, | |
1535 | struct perf_event_context *ctx) | |
1536 | { | |
1537 | u64 tstamp = perf_event_time(event); | |
1538 | u64 delta; | |
1539 | ||
1540 | WARN_ON_ONCE(event->ctx != ctx); | |
1541 | lockdep_assert_held(&ctx->lock); | |
1542 | ||
1543 | /* | |
1544 | * An event which could not be activated because of | |
1545 | * filter mismatch still needs to have its timings | |
1546 | * maintained, otherwise bogus information is return | |
1547 | * via read() for time_enabled, time_running: | |
1548 | */ | |
1549 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1550 | && !event_filter_match(event)) { | |
1551 | delta = tstamp - event->tstamp_stopped; | |
1552 | event->tstamp_running += delta; | |
1553 | event->tstamp_stopped = tstamp; | |
1554 | } | |
1555 | ||
1556 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
1557 | return; | |
1558 | ||
1559 | perf_pmu_disable(event->pmu); | |
1560 | ||
1561 | event->state = PERF_EVENT_STATE_INACTIVE; | |
1562 | if (event->pending_disable) { | |
1563 | event->pending_disable = 0; | |
1564 | event->state = PERF_EVENT_STATE_OFF; | |
1565 | } | |
1566 | event->tstamp_stopped = tstamp; | |
1567 | event->pmu->del(event, 0); | |
1568 | event->oncpu = -1; | |
1569 | ||
1570 | if (!is_software_event(event)) | |
1571 | cpuctx->active_oncpu--; | |
1572 | if (!--ctx->nr_active) | |
1573 | perf_event_ctx_deactivate(ctx); | |
1574 | if (event->attr.freq && event->attr.sample_freq) | |
1575 | ctx->nr_freq--; | |
1576 | if (event->attr.exclusive || !cpuctx->active_oncpu) | |
1577 | cpuctx->exclusive = 0; | |
1578 | ||
1579 | if (is_orphaned_child(event)) | |
1580 | schedule_orphans_remove(ctx); | |
1581 | ||
1582 | perf_pmu_enable(event->pmu); | |
1583 | } | |
1584 | ||
1585 | static void | |
1586 | group_sched_out(struct perf_event *group_event, | |
1587 | struct perf_cpu_context *cpuctx, | |
1588 | struct perf_event_context *ctx) | |
1589 | { | |
1590 | struct perf_event *event; | |
1591 | int state = group_event->state; | |
1592 | ||
1593 | event_sched_out(group_event, cpuctx, ctx); | |
1594 | ||
1595 | /* | |
1596 | * Schedule out siblings (if any): | |
1597 | */ | |
1598 | list_for_each_entry(event, &group_event->sibling_list, group_entry) | |
1599 | event_sched_out(event, cpuctx, ctx); | |
1600 | ||
1601 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) | |
1602 | cpuctx->exclusive = 0; | |
1603 | } | |
1604 | ||
1605 | struct remove_event { | |
1606 | struct perf_event *event; | |
1607 | bool detach_group; | |
1608 | }; | |
1609 | ||
1610 | /* | |
1611 | * Cross CPU call to remove a performance event | |
1612 | * | |
1613 | * We disable the event on the hardware level first. After that we | |
1614 | * remove it from the context list. | |
1615 | */ | |
1616 | static int __perf_remove_from_context(void *info) | |
1617 | { | |
1618 | struct remove_event *re = info; | |
1619 | struct perf_event *event = re->event; | |
1620 | struct perf_event_context *ctx = event->ctx; | |
1621 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
1622 | ||
1623 | raw_spin_lock(&ctx->lock); | |
1624 | event_sched_out(event, cpuctx, ctx); | |
1625 | if (re->detach_group) | |
1626 | perf_group_detach(event); | |
1627 | list_del_event(event, ctx); | |
1628 | if (!ctx->nr_events && cpuctx->task_ctx == ctx) { | |
1629 | ctx->is_active = 0; | |
1630 | cpuctx->task_ctx = NULL; | |
1631 | } | |
1632 | raw_spin_unlock(&ctx->lock); | |
1633 | ||
1634 | return 0; | |
1635 | } | |
1636 | ||
1637 | ||
1638 | /* | |
1639 | * Remove the event from a task's (or a CPU's) list of events. | |
1640 | * | |
1641 | * CPU events are removed with a smp call. For task events we only | |
1642 | * call when the task is on a CPU. | |
1643 | * | |
1644 | * If event->ctx is a cloned context, callers must make sure that | |
1645 | * every task struct that event->ctx->task could possibly point to | |
1646 | * remains valid. This is OK when called from perf_release since | |
1647 | * that only calls us on the top-level context, which can't be a clone. | |
1648 | * When called from perf_event_exit_task, it's OK because the | |
1649 | * context has been detached from its task. | |
1650 | */ | |
1651 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) | |
1652 | { | |
1653 | struct perf_event_context *ctx = event->ctx; | |
1654 | struct task_struct *task = ctx->task; | |
1655 | struct remove_event re = { | |
1656 | .event = event, | |
1657 | .detach_group = detach_group, | |
1658 | }; | |
1659 | ||
1660 | lockdep_assert_held(&ctx->mutex); | |
1661 | ||
1662 | if (!task) { | |
1663 | /* | |
1664 | * Per cpu events are removed via an smp call. The removal can | |
1665 | * fail if the CPU is currently offline, but in that case we | |
1666 | * already called __perf_remove_from_context from | |
1667 | * perf_event_exit_cpu. | |
1668 | */ | |
1669 | cpu_function_call(event->cpu, __perf_remove_from_context, &re); | |
1670 | return; | |
1671 | } | |
1672 | ||
1673 | retry: | |
1674 | if (!task_function_call(task, __perf_remove_from_context, &re)) | |
1675 | return; | |
1676 | ||
1677 | raw_spin_lock_irq(&ctx->lock); | |
1678 | /* | |
1679 | * If we failed to find a running task, but find the context active now | |
1680 | * that we've acquired the ctx->lock, retry. | |
1681 | */ | |
1682 | if (ctx->is_active) { | |
1683 | raw_spin_unlock_irq(&ctx->lock); | |
1684 | /* | |
1685 | * Reload the task pointer, it might have been changed by | |
1686 | * a concurrent perf_event_context_sched_out(). | |
1687 | */ | |
1688 | task = ctx->task; | |
1689 | goto retry; | |
1690 | } | |
1691 | ||
1692 | /* | |
1693 | * Since the task isn't running, its safe to remove the event, us | |
1694 | * holding the ctx->lock ensures the task won't get scheduled in. | |
1695 | */ | |
1696 | if (detach_group) | |
1697 | perf_group_detach(event); | |
1698 | list_del_event(event, ctx); | |
1699 | raw_spin_unlock_irq(&ctx->lock); | |
1700 | } | |
1701 | ||
1702 | /* | |
1703 | * Cross CPU call to disable a performance event | |
1704 | */ | |
1705 | int __perf_event_disable(void *info) | |
1706 | { | |
1707 | struct perf_event *event = info; | |
1708 | struct perf_event_context *ctx = event->ctx; | |
1709 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
1710 | ||
1711 | /* | |
1712 | * If this is a per-task event, need to check whether this | |
1713 | * event's task is the current task on this cpu. | |
1714 | * | |
1715 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1716 | * flipping contexts around. | |
1717 | */ | |
1718 | if (ctx->task && cpuctx->task_ctx != ctx) | |
1719 | return -EINVAL; | |
1720 | ||
1721 | raw_spin_lock(&ctx->lock); | |
1722 | ||
1723 | /* | |
1724 | * If the event is on, turn it off. | |
1725 | * If it is in error state, leave it in error state. | |
1726 | */ | |
1727 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
1728 | update_context_time(ctx); | |
1729 | update_cgrp_time_from_event(event); | |
1730 | update_group_times(event); | |
1731 | if (event == event->group_leader) | |
1732 | group_sched_out(event, cpuctx, ctx); | |
1733 | else | |
1734 | event_sched_out(event, cpuctx, ctx); | |
1735 | event->state = PERF_EVENT_STATE_OFF; | |
1736 | } | |
1737 | ||
1738 | raw_spin_unlock(&ctx->lock); | |
1739 | ||
1740 | return 0; | |
1741 | } | |
1742 | ||
1743 | /* | |
1744 | * Disable a event. | |
1745 | * | |
1746 | * If event->ctx is a cloned context, callers must make sure that | |
1747 | * every task struct that event->ctx->task could possibly point to | |
1748 | * remains valid. This condition is satisifed when called through | |
1749 | * perf_event_for_each_child or perf_event_for_each because they | |
1750 | * hold the top-level event's child_mutex, so any descendant that | |
1751 | * goes to exit will block in sync_child_event. | |
1752 | * When called from perf_pending_event it's OK because event->ctx | |
1753 | * is the current context on this CPU and preemption is disabled, | |
1754 | * hence we can't get into perf_event_task_sched_out for this context. | |
1755 | */ | |
1756 | static void _perf_event_disable(struct perf_event *event) | |
1757 | { | |
1758 | struct perf_event_context *ctx = event->ctx; | |
1759 | struct task_struct *task = ctx->task; | |
1760 | ||
1761 | if (!task) { | |
1762 | /* | |
1763 | * Disable the event on the cpu that it's on | |
1764 | */ | |
1765 | cpu_function_call(event->cpu, __perf_event_disable, event); | |
1766 | return; | |
1767 | } | |
1768 | ||
1769 | retry: | |
1770 | if (!task_function_call(task, __perf_event_disable, event)) | |
1771 | return; | |
1772 | ||
1773 | raw_spin_lock_irq(&ctx->lock); | |
1774 | /* | |
1775 | * If the event is still active, we need to retry the cross-call. | |
1776 | */ | |
1777 | if (event->state == PERF_EVENT_STATE_ACTIVE) { | |
1778 | raw_spin_unlock_irq(&ctx->lock); | |
1779 | /* | |
1780 | * Reload the task pointer, it might have been changed by | |
1781 | * a concurrent perf_event_context_sched_out(). | |
1782 | */ | |
1783 | task = ctx->task; | |
1784 | goto retry; | |
1785 | } | |
1786 | ||
1787 | /* | |
1788 | * Since we have the lock this context can't be scheduled | |
1789 | * in, so we can change the state safely. | |
1790 | */ | |
1791 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
1792 | update_group_times(event); | |
1793 | event->state = PERF_EVENT_STATE_OFF; | |
1794 | } | |
1795 | raw_spin_unlock_irq(&ctx->lock); | |
1796 | } | |
1797 | ||
1798 | /* | |
1799 | * Strictly speaking kernel users cannot create groups and therefore this | |
1800 | * interface does not need the perf_event_ctx_lock() magic. | |
1801 | */ | |
1802 | void perf_event_disable(struct perf_event *event) | |
1803 | { | |
1804 | struct perf_event_context *ctx; | |
1805 | ||
1806 | ctx = perf_event_ctx_lock(event); | |
1807 | _perf_event_disable(event); | |
1808 | perf_event_ctx_unlock(event, ctx); | |
1809 | } | |
1810 | EXPORT_SYMBOL_GPL(perf_event_disable); | |
1811 | ||
1812 | static void perf_set_shadow_time(struct perf_event *event, | |
1813 | struct perf_event_context *ctx, | |
1814 | u64 tstamp) | |
1815 | { | |
1816 | /* | |
1817 | * use the correct time source for the time snapshot | |
1818 | * | |
1819 | * We could get by without this by leveraging the | |
1820 | * fact that to get to this function, the caller | |
1821 | * has most likely already called update_context_time() | |
1822 | * and update_cgrp_time_xx() and thus both timestamp | |
1823 | * are identical (or very close). Given that tstamp is, | |
1824 | * already adjusted for cgroup, we could say that: | |
1825 | * tstamp - ctx->timestamp | |
1826 | * is equivalent to | |
1827 | * tstamp - cgrp->timestamp. | |
1828 | * | |
1829 | * Then, in perf_output_read(), the calculation would | |
1830 | * work with no changes because: | |
1831 | * - event is guaranteed scheduled in | |
1832 | * - no scheduled out in between | |
1833 | * - thus the timestamp would be the same | |
1834 | * | |
1835 | * But this is a bit hairy. | |
1836 | * | |
1837 | * So instead, we have an explicit cgroup call to remain | |
1838 | * within the time time source all along. We believe it | |
1839 | * is cleaner and simpler to understand. | |
1840 | */ | |
1841 | if (is_cgroup_event(event)) | |
1842 | perf_cgroup_set_shadow_time(event, tstamp); | |
1843 | else | |
1844 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1845 | } | |
1846 | ||
1847 | #define MAX_INTERRUPTS (~0ULL) | |
1848 | ||
1849 | static void perf_log_throttle(struct perf_event *event, int enable); | |
1850 | ||
1851 | static int | |
1852 | event_sched_in(struct perf_event *event, | |
1853 | struct perf_cpu_context *cpuctx, | |
1854 | struct perf_event_context *ctx) | |
1855 | { | |
1856 | u64 tstamp = perf_event_time(event); | |
1857 | int ret = 0; | |
1858 | ||
1859 | lockdep_assert_held(&ctx->lock); | |
1860 | ||
1861 | if (event->state <= PERF_EVENT_STATE_OFF) | |
1862 | return 0; | |
1863 | ||
1864 | event->state = PERF_EVENT_STATE_ACTIVE; | |
1865 | event->oncpu = smp_processor_id(); | |
1866 | ||
1867 | /* | |
1868 | * Unthrottle events, since we scheduled we might have missed several | |
1869 | * ticks already, also for a heavily scheduling task there is little | |
1870 | * guarantee it'll get a tick in a timely manner. | |
1871 | */ | |
1872 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1873 | perf_log_throttle(event, 1); | |
1874 | event->hw.interrupts = 0; | |
1875 | } | |
1876 | ||
1877 | /* | |
1878 | * The new state must be visible before we turn it on in the hardware: | |
1879 | */ | |
1880 | smp_wmb(); | |
1881 | ||
1882 | perf_pmu_disable(event->pmu); | |
1883 | ||
1884 | if (event->pmu->add(event, PERF_EF_START)) { | |
1885 | event->state = PERF_EVENT_STATE_INACTIVE; | |
1886 | event->oncpu = -1; | |
1887 | ret = -EAGAIN; | |
1888 | goto out; | |
1889 | } | |
1890 | ||
1891 | event->tstamp_running += tstamp - event->tstamp_stopped; | |
1892 | ||
1893 | perf_set_shadow_time(event, ctx, tstamp); | |
1894 | ||
1895 | if (!is_software_event(event)) | |
1896 | cpuctx->active_oncpu++; | |
1897 | if (!ctx->nr_active++) | |
1898 | perf_event_ctx_activate(ctx); | |
1899 | if (event->attr.freq && event->attr.sample_freq) | |
1900 | ctx->nr_freq++; | |
1901 | ||
1902 | if (event->attr.exclusive) | |
1903 | cpuctx->exclusive = 1; | |
1904 | ||
1905 | if (is_orphaned_child(event)) | |
1906 | schedule_orphans_remove(ctx); | |
1907 | ||
1908 | out: | |
1909 | perf_pmu_enable(event->pmu); | |
1910 | ||
1911 | return ret; | |
1912 | } | |
1913 | ||
1914 | static int | |
1915 | group_sched_in(struct perf_event *group_event, | |
1916 | struct perf_cpu_context *cpuctx, | |
1917 | struct perf_event_context *ctx) | |
1918 | { | |
1919 | struct perf_event *event, *partial_group = NULL; | |
1920 | struct pmu *pmu = ctx->pmu; | |
1921 | u64 now = ctx->time; | |
1922 | bool simulate = false; | |
1923 | ||
1924 | if (group_event->state == PERF_EVENT_STATE_OFF) | |
1925 | return 0; | |
1926 | ||
1927 | pmu->start_txn(pmu); | |
1928 | ||
1929 | if (event_sched_in(group_event, cpuctx, ctx)) { | |
1930 | pmu->cancel_txn(pmu); | |
1931 | perf_cpu_hrtimer_restart(cpuctx); | |
1932 | return -EAGAIN; | |
1933 | } | |
1934 | ||
1935 | /* | |
1936 | * Schedule in siblings as one group (if any): | |
1937 | */ | |
1938 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { | |
1939 | if (event_sched_in(event, cpuctx, ctx)) { | |
1940 | partial_group = event; | |
1941 | goto group_error; | |
1942 | } | |
1943 | } | |
1944 | ||
1945 | if (!pmu->commit_txn(pmu)) | |
1946 | return 0; | |
1947 | ||
1948 | group_error: | |
1949 | /* | |
1950 | * Groups can be scheduled in as one unit only, so undo any | |
1951 | * partial group before returning: | |
1952 | * The events up to the failed event are scheduled out normally, | |
1953 | * tstamp_stopped will be updated. | |
1954 | * | |
1955 | * The failed events and the remaining siblings need to have | |
1956 | * their timings updated as if they had gone thru event_sched_in() | |
1957 | * and event_sched_out(). This is required to get consistent timings | |
1958 | * across the group. This also takes care of the case where the group | |
1959 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1960 | * the time the event was actually stopped, such that time delta | |
1961 | * calculation in update_event_times() is correct. | |
1962 | */ | |
1963 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { | |
1964 | if (event == partial_group) | |
1965 | simulate = true; | |
1966 | ||
1967 | if (simulate) { | |
1968 | event->tstamp_running += now - event->tstamp_stopped; | |
1969 | event->tstamp_stopped = now; | |
1970 | } else { | |
1971 | event_sched_out(event, cpuctx, ctx); | |
1972 | } | |
1973 | } | |
1974 | event_sched_out(group_event, cpuctx, ctx); | |
1975 | ||
1976 | pmu->cancel_txn(pmu); | |
1977 | ||
1978 | perf_cpu_hrtimer_restart(cpuctx); | |
1979 | ||
1980 | return -EAGAIN; | |
1981 | } | |
1982 | ||
1983 | /* | |
1984 | * Work out whether we can put this event group on the CPU now. | |
1985 | */ | |
1986 | static int group_can_go_on(struct perf_event *event, | |
1987 | struct perf_cpu_context *cpuctx, | |
1988 | int can_add_hw) | |
1989 | { | |
1990 | /* | |
1991 | * Groups consisting entirely of software events can always go on. | |
1992 | */ | |
1993 | if (event->group_flags & PERF_GROUP_SOFTWARE) | |
1994 | return 1; | |
1995 | /* | |
1996 | * If an exclusive group is already on, no other hardware | |
1997 | * events can go on. | |
1998 | */ | |
1999 | if (cpuctx->exclusive) | |
2000 | return 0; | |
2001 | /* | |
2002 | * If this group is exclusive and there are already | |
2003 | * events on the CPU, it can't go on. | |
2004 | */ | |
2005 | if (event->attr.exclusive && cpuctx->active_oncpu) | |
2006 | return 0; | |
2007 | /* | |
2008 | * Otherwise, try to add it if all previous groups were able | |
2009 | * to go on. | |
2010 | */ | |
2011 | return can_add_hw; | |
2012 | } | |
2013 | ||
2014 | static void add_event_to_ctx(struct perf_event *event, | |
2015 | struct perf_event_context *ctx) | |
2016 | { | |
2017 | u64 tstamp = perf_event_time(event); | |
2018 | ||
2019 | list_add_event(event, ctx); | |
2020 | perf_group_attach(event); | |
2021 | event->tstamp_enabled = tstamp; | |
2022 | event->tstamp_running = tstamp; | |
2023 | event->tstamp_stopped = tstamp; | |
2024 | } | |
2025 | ||
2026 | static void task_ctx_sched_out(struct perf_event_context *ctx); | |
2027 | static void | |
2028 | ctx_sched_in(struct perf_event_context *ctx, | |
2029 | struct perf_cpu_context *cpuctx, | |
2030 | enum event_type_t event_type, | |
2031 | struct task_struct *task); | |
2032 | ||
2033 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, | |
2034 | struct perf_event_context *ctx, | |
2035 | struct task_struct *task) | |
2036 | { | |
2037 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2038 | if (ctx) | |
2039 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2040 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2041 | if (ctx) | |
2042 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2043 | } | |
2044 | ||
2045 | /* | |
2046 | * Cross CPU call to install and enable a performance event | |
2047 | * | |
2048 | * Must be called with ctx->mutex held | |
2049 | */ | |
2050 | static int __perf_install_in_context(void *info) | |
2051 | { | |
2052 | struct perf_event *event = info; | |
2053 | struct perf_event_context *ctx = event->ctx; | |
2054 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
2055 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
2056 | struct task_struct *task = current; | |
2057 | ||
2058 | perf_ctx_lock(cpuctx, task_ctx); | |
2059 | perf_pmu_disable(cpuctx->ctx.pmu); | |
2060 | ||
2061 | /* | |
2062 | * If there was an active task_ctx schedule it out. | |
2063 | */ | |
2064 | if (task_ctx) | |
2065 | task_ctx_sched_out(task_ctx); | |
2066 | ||
2067 | /* | |
2068 | * If the context we're installing events in is not the | |
2069 | * active task_ctx, flip them. | |
2070 | */ | |
2071 | if (ctx->task && task_ctx != ctx) { | |
2072 | if (task_ctx) | |
2073 | raw_spin_unlock(&task_ctx->lock); | |
2074 | raw_spin_lock(&ctx->lock); | |
2075 | task_ctx = ctx; | |
2076 | } | |
2077 | ||
2078 | if (task_ctx) { | |
2079 | cpuctx->task_ctx = task_ctx; | |
2080 | task = task_ctx->task; | |
2081 | } | |
2082 | ||
2083 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2084 | ||
2085 | update_context_time(ctx); | |
2086 | /* | |
2087 | * update cgrp time only if current cgrp | |
2088 | * matches event->cgrp. Must be done before | |
2089 | * calling add_event_to_ctx() | |
2090 | */ | |
2091 | update_cgrp_time_from_event(event); | |
2092 | ||
2093 | add_event_to_ctx(event, ctx); | |
2094 | ||
2095 | /* | |
2096 | * Schedule everything back in | |
2097 | */ | |
2098 | perf_event_sched_in(cpuctx, task_ctx, task); | |
2099 | ||
2100 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2101 | perf_ctx_unlock(cpuctx, task_ctx); | |
2102 | ||
2103 | return 0; | |
2104 | } | |
2105 | ||
2106 | /* | |
2107 | * Attach a performance event to a context | |
2108 | * | |
2109 | * First we add the event to the list with the hardware enable bit | |
2110 | * in event->hw_config cleared. | |
2111 | * | |
2112 | * If the event is attached to a task which is on a CPU we use a smp | |
2113 | * call to enable it in the task context. The task might have been | |
2114 | * scheduled away, but we check this in the smp call again. | |
2115 | */ | |
2116 | static void | |
2117 | perf_install_in_context(struct perf_event_context *ctx, | |
2118 | struct perf_event *event, | |
2119 | int cpu) | |
2120 | { | |
2121 | struct task_struct *task = ctx->task; | |
2122 | ||
2123 | lockdep_assert_held(&ctx->mutex); | |
2124 | ||
2125 | event->ctx = ctx; | |
2126 | if (event->cpu != -1) | |
2127 | event->cpu = cpu; | |
2128 | ||
2129 | if (!task) { | |
2130 | /* | |
2131 | * Per cpu events are installed via an smp call and | |
2132 | * the install is always successful. | |
2133 | */ | |
2134 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2135 | return; | |
2136 | } | |
2137 | ||
2138 | retry: | |
2139 | if (!task_function_call(task, __perf_install_in_context, event)) | |
2140 | return; | |
2141 | ||
2142 | raw_spin_lock_irq(&ctx->lock); | |
2143 | /* | |
2144 | * If we failed to find a running task, but find the context active now | |
2145 | * that we've acquired the ctx->lock, retry. | |
2146 | */ | |
2147 | if (ctx->is_active) { | |
2148 | raw_spin_unlock_irq(&ctx->lock); | |
2149 | /* | |
2150 | * Reload the task pointer, it might have been changed by | |
2151 | * a concurrent perf_event_context_sched_out(). | |
2152 | */ | |
2153 | task = ctx->task; | |
2154 | goto retry; | |
2155 | } | |
2156 | ||
2157 | /* | |
2158 | * Since the task isn't running, its safe to add the event, us holding | |
2159 | * the ctx->lock ensures the task won't get scheduled in. | |
2160 | */ | |
2161 | add_event_to_ctx(event, ctx); | |
2162 | raw_spin_unlock_irq(&ctx->lock); | |
2163 | } | |
2164 | ||
2165 | /* | |
2166 | * Put a event into inactive state and update time fields. | |
2167 | * Enabling the leader of a group effectively enables all | |
2168 | * the group members that aren't explicitly disabled, so we | |
2169 | * have to update their ->tstamp_enabled also. | |
2170 | * Note: this works for group members as well as group leaders | |
2171 | * since the non-leader members' sibling_lists will be empty. | |
2172 | */ | |
2173 | static void __perf_event_mark_enabled(struct perf_event *event) | |
2174 | { | |
2175 | struct perf_event *sub; | |
2176 | u64 tstamp = perf_event_time(event); | |
2177 | ||
2178 | event->state = PERF_EVENT_STATE_INACTIVE; | |
2179 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
2180 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
2181 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) | |
2182 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
2183 | } | |
2184 | } | |
2185 | ||
2186 | /* | |
2187 | * Cross CPU call to enable a performance event | |
2188 | */ | |
2189 | static int __perf_event_enable(void *info) | |
2190 | { | |
2191 | struct perf_event *event = info; | |
2192 | struct perf_event_context *ctx = event->ctx; | |
2193 | struct perf_event *leader = event->group_leader; | |
2194 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
2195 | int err; | |
2196 | ||
2197 | /* | |
2198 | * There's a time window between 'ctx->is_active' check | |
2199 | * in perf_event_enable function and this place having: | |
2200 | * - IRQs on | |
2201 | * - ctx->lock unlocked | |
2202 | * | |
2203 | * where the task could be killed and 'ctx' deactivated | |
2204 | * by perf_event_exit_task. | |
2205 | */ | |
2206 | if (!ctx->is_active) | |
2207 | return -EINVAL; | |
2208 | ||
2209 | raw_spin_lock(&ctx->lock); | |
2210 | update_context_time(ctx); | |
2211 | ||
2212 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
2213 | goto unlock; | |
2214 | ||
2215 | /* | |
2216 | * set current task's cgroup time reference point | |
2217 | */ | |
2218 | perf_cgroup_set_timestamp(current, ctx); | |
2219 | ||
2220 | __perf_event_mark_enabled(event); | |
2221 | ||
2222 | if (!event_filter_match(event)) { | |
2223 | if (is_cgroup_event(event)) | |
2224 | perf_cgroup_defer_enabled(event); | |
2225 | goto unlock; | |
2226 | } | |
2227 | ||
2228 | /* | |
2229 | * If the event is in a group and isn't the group leader, | |
2230 | * then don't put it on unless the group is on. | |
2231 | */ | |
2232 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) | |
2233 | goto unlock; | |
2234 | ||
2235 | if (!group_can_go_on(event, cpuctx, 1)) { | |
2236 | err = -EEXIST; | |
2237 | } else { | |
2238 | if (event == leader) | |
2239 | err = group_sched_in(event, cpuctx, ctx); | |
2240 | else | |
2241 | err = event_sched_in(event, cpuctx, ctx); | |
2242 | } | |
2243 | ||
2244 | if (err) { | |
2245 | /* | |
2246 | * If this event can't go on and it's part of a | |
2247 | * group, then the whole group has to come off. | |
2248 | */ | |
2249 | if (leader != event) { | |
2250 | group_sched_out(leader, cpuctx, ctx); | |
2251 | perf_cpu_hrtimer_restart(cpuctx); | |
2252 | } | |
2253 | if (leader->attr.pinned) { | |
2254 | update_group_times(leader); | |
2255 | leader->state = PERF_EVENT_STATE_ERROR; | |
2256 | } | |
2257 | } | |
2258 | ||
2259 | unlock: | |
2260 | raw_spin_unlock(&ctx->lock); | |
2261 | ||
2262 | return 0; | |
2263 | } | |
2264 | ||
2265 | /* | |
2266 | * Enable a event. | |
2267 | * | |
2268 | * If event->ctx is a cloned context, callers must make sure that | |
2269 | * every task struct that event->ctx->task could possibly point to | |
2270 | * remains valid. This condition is satisfied when called through | |
2271 | * perf_event_for_each_child or perf_event_for_each as described | |
2272 | * for perf_event_disable. | |
2273 | */ | |
2274 | static void _perf_event_enable(struct perf_event *event) | |
2275 | { | |
2276 | struct perf_event_context *ctx = event->ctx; | |
2277 | struct task_struct *task = ctx->task; | |
2278 | ||
2279 | if (!task) { | |
2280 | /* | |
2281 | * Enable the event on the cpu that it's on | |
2282 | */ | |
2283 | cpu_function_call(event->cpu, __perf_event_enable, event); | |
2284 | return; | |
2285 | } | |
2286 | ||
2287 | raw_spin_lock_irq(&ctx->lock); | |
2288 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
2289 | goto out; | |
2290 | ||
2291 | /* | |
2292 | * If the event is in error state, clear that first. | |
2293 | * That way, if we see the event in error state below, we | |
2294 | * know that it has gone back into error state, as distinct | |
2295 | * from the task having been scheduled away before the | |
2296 | * cross-call arrived. | |
2297 | */ | |
2298 | if (event->state == PERF_EVENT_STATE_ERROR) | |
2299 | event->state = PERF_EVENT_STATE_OFF; | |
2300 | ||
2301 | retry: | |
2302 | if (!ctx->is_active) { | |
2303 | __perf_event_mark_enabled(event); | |
2304 | goto out; | |
2305 | } | |
2306 | ||
2307 | raw_spin_unlock_irq(&ctx->lock); | |
2308 | ||
2309 | if (!task_function_call(task, __perf_event_enable, event)) | |
2310 | return; | |
2311 | ||
2312 | raw_spin_lock_irq(&ctx->lock); | |
2313 | ||
2314 | /* | |
2315 | * If the context is active and the event is still off, | |
2316 | * we need to retry the cross-call. | |
2317 | */ | |
2318 | if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) { | |
2319 | /* | |
2320 | * task could have been flipped by a concurrent | |
2321 | * perf_event_context_sched_out() | |
2322 | */ | |
2323 | task = ctx->task; | |
2324 | goto retry; | |
2325 | } | |
2326 | ||
2327 | out: | |
2328 | raw_spin_unlock_irq(&ctx->lock); | |
2329 | } | |
2330 | ||
2331 | /* | |
2332 | * See perf_event_disable(); | |
2333 | */ | |
2334 | void perf_event_enable(struct perf_event *event) | |
2335 | { | |
2336 | struct perf_event_context *ctx; | |
2337 | ||
2338 | ctx = perf_event_ctx_lock(event); | |
2339 | _perf_event_enable(event); | |
2340 | perf_event_ctx_unlock(event, ctx); | |
2341 | } | |
2342 | EXPORT_SYMBOL_GPL(perf_event_enable); | |
2343 | ||
2344 | static int _perf_event_refresh(struct perf_event *event, int refresh) | |
2345 | { | |
2346 | /* | |
2347 | * not supported on inherited events | |
2348 | */ | |
2349 | if (event->attr.inherit || !is_sampling_event(event)) | |
2350 | return -EINVAL; | |
2351 | ||
2352 | atomic_add(refresh, &event->event_limit); | |
2353 | _perf_event_enable(event); | |
2354 | ||
2355 | return 0; | |
2356 | } | |
2357 | ||
2358 | /* | |
2359 | * See perf_event_disable() | |
2360 | */ | |
2361 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2362 | { | |
2363 | struct perf_event_context *ctx; | |
2364 | int ret; | |
2365 | ||
2366 | ctx = perf_event_ctx_lock(event); | |
2367 | ret = _perf_event_refresh(event, refresh); | |
2368 | perf_event_ctx_unlock(event, ctx); | |
2369 | ||
2370 | return ret; | |
2371 | } | |
2372 | EXPORT_SYMBOL_GPL(perf_event_refresh); | |
2373 | ||
2374 | static void ctx_sched_out(struct perf_event_context *ctx, | |
2375 | struct perf_cpu_context *cpuctx, | |
2376 | enum event_type_t event_type) | |
2377 | { | |
2378 | struct perf_event *event; | |
2379 | int is_active = ctx->is_active; | |
2380 | ||
2381 | ctx->is_active &= ~event_type; | |
2382 | if (likely(!ctx->nr_events)) | |
2383 | return; | |
2384 | ||
2385 | update_context_time(ctx); | |
2386 | update_cgrp_time_from_cpuctx(cpuctx); | |
2387 | if (!ctx->nr_active) | |
2388 | return; | |
2389 | ||
2390 | perf_pmu_disable(ctx->pmu); | |
2391 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { | |
2392 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) | |
2393 | group_sched_out(event, cpuctx, ctx); | |
2394 | } | |
2395 | ||
2396 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { | |
2397 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) | |
2398 | group_sched_out(event, cpuctx, ctx); | |
2399 | } | |
2400 | perf_pmu_enable(ctx->pmu); | |
2401 | } | |
2402 | ||
2403 | /* | |
2404 | * Test whether two contexts are equivalent, i.e. whether they have both been | |
2405 | * cloned from the same version of the same context. | |
2406 | * | |
2407 | * Equivalence is measured using a generation number in the context that is | |
2408 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2409 | * and list_del_event(). | |
2410 | */ | |
2411 | static int context_equiv(struct perf_event_context *ctx1, | |
2412 | struct perf_event_context *ctx2) | |
2413 | { | |
2414 | lockdep_assert_held(&ctx1->lock); | |
2415 | lockdep_assert_held(&ctx2->lock); | |
2416 | ||
2417 | /* Pinning disables the swap optimization */ | |
2418 | if (ctx1->pin_count || ctx2->pin_count) | |
2419 | return 0; | |
2420 | ||
2421 | /* If ctx1 is the parent of ctx2 */ | |
2422 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2423 | return 1; | |
2424 | ||
2425 | /* If ctx2 is the parent of ctx1 */ | |
2426 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2427 | return 1; | |
2428 | ||
2429 | /* | |
2430 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2431 | * hierarchy, see perf_event_init_context(). | |
2432 | */ | |
2433 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2434 | ctx1->parent_gen == ctx2->parent_gen) | |
2435 | return 1; | |
2436 | ||
2437 | /* Unmatched */ | |
2438 | return 0; | |
2439 | } | |
2440 | ||
2441 | static void __perf_event_sync_stat(struct perf_event *event, | |
2442 | struct perf_event *next_event) | |
2443 | { | |
2444 | u64 value; | |
2445 | ||
2446 | if (!event->attr.inherit_stat) | |
2447 | return; | |
2448 | ||
2449 | /* | |
2450 | * Update the event value, we cannot use perf_event_read() | |
2451 | * because we're in the middle of a context switch and have IRQs | |
2452 | * disabled, which upsets smp_call_function_single(), however | |
2453 | * we know the event must be on the current CPU, therefore we | |
2454 | * don't need to use it. | |
2455 | */ | |
2456 | switch (event->state) { | |
2457 | case PERF_EVENT_STATE_ACTIVE: | |
2458 | event->pmu->read(event); | |
2459 | /* fall-through */ | |
2460 | ||
2461 | case PERF_EVENT_STATE_INACTIVE: | |
2462 | update_event_times(event); | |
2463 | break; | |
2464 | ||
2465 | default: | |
2466 | break; | |
2467 | } | |
2468 | ||
2469 | /* | |
2470 | * In order to keep per-task stats reliable we need to flip the event | |
2471 | * values when we flip the contexts. | |
2472 | */ | |
2473 | value = local64_read(&next_event->count); | |
2474 | value = local64_xchg(&event->count, value); | |
2475 | local64_set(&next_event->count, value); | |
2476 | ||
2477 | swap(event->total_time_enabled, next_event->total_time_enabled); | |
2478 | swap(event->total_time_running, next_event->total_time_running); | |
2479 | ||
2480 | /* | |
2481 | * Since we swizzled the values, update the user visible data too. | |
2482 | */ | |
2483 | perf_event_update_userpage(event); | |
2484 | perf_event_update_userpage(next_event); | |
2485 | } | |
2486 | ||
2487 | static void perf_event_sync_stat(struct perf_event_context *ctx, | |
2488 | struct perf_event_context *next_ctx) | |
2489 | { | |
2490 | struct perf_event *event, *next_event; | |
2491 | ||
2492 | if (!ctx->nr_stat) | |
2493 | return; | |
2494 | ||
2495 | update_context_time(ctx); | |
2496 | ||
2497 | event = list_first_entry(&ctx->event_list, | |
2498 | struct perf_event, event_entry); | |
2499 | ||
2500 | next_event = list_first_entry(&next_ctx->event_list, | |
2501 | struct perf_event, event_entry); | |
2502 | ||
2503 | while (&event->event_entry != &ctx->event_list && | |
2504 | &next_event->event_entry != &next_ctx->event_list) { | |
2505 | ||
2506 | __perf_event_sync_stat(event, next_event); | |
2507 | ||
2508 | event = list_next_entry(event, event_entry); | |
2509 | next_event = list_next_entry(next_event, event_entry); | |
2510 | } | |
2511 | } | |
2512 | ||
2513 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, | |
2514 | struct task_struct *next) | |
2515 | { | |
2516 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; | |
2517 | struct perf_event_context *next_ctx; | |
2518 | struct perf_event_context *parent, *next_parent; | |
2519 | struct perf_cpu_context *cpuctx; | |
2520 | int do_switch = 1; | |
2521 | ||
2522 | if (likely(!ctx)) | |
2523 | return; | |
2524 | ||
2525 | cpuctx = __get_cpu_context(ctx); | |
2526 | if (!cpuctx->task_ctx) | |
2527 | return; | |
2528 | ||
2529 | rcu_read_lock(); | |
2530 | next_ctx = next->perf_event_ctxp[ctxn]; | |
2531 | if (!next_ctx) | |
2532 | goto unlock; | |
2533 | ||
2534 | parent = rcu_dereference(ctx->parent_ctx); | |
2535 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2536 | ||
2537 | /* If neither context have a parent context; they cannot be clones. */ | |
2538 | if (!parent && !next_parent) | |
2539 | goto unlock; | |
2540 | ||
2541 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
2542 | /* | |
2543 | * Looks like the two contexts are clones, so we might be | |
2544 | * able to optimize the context switch. We lock both | |
2545 | * contexts and check that they are clones under the | |
2546 | * lock (including re-checking that neither has been | |
2547 | * uncloned in the meantime). It doesn't matter which | |
2548 | * order we take the locks because no other cpu could | |
2549 | * be trying to lock both of these tasks. | |
2550 | */ | |
2551 | raw_spin_lock(&ctx->lock); | |
2552 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
2553 | if (context_equiv(ctx, next_ctx)) { | |
2554 | /* | |
2555 | * XXX do we need a memory barrier of sorts | |
2556 | * wrt to rcu_dereference() of perf_event_ctxp | |
2557 | */ | |
2558 | task->perf_event_ctxp[ctxn] = next_ctx; | |
2559 | next->perf_event_ctxp[ctxn] = ctx; | |
2560 | ctx->task = next; | |
2561 | next_ctx->task = task; | |
2562 | do_switch = 0; | |
2563 | ||
2564 | perf_event_sync_stat(ctx, next_ctx); | |
2565 | } | |
2566 | raw_spin_unlock(&next_ctx->lock); | |
2567 | raw_spin_unlock(&ctx->lock); | |
2568 | } | |
2569 | unlock: | |
2570 | rcu_read_unlock(); | |
2571 | ||
2572 | if (do_switch) { | |
2573 | raw_spin_lock(&ctx->lock); | |
2574 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); | |
2575 | cpuctx->task_ctx = NULL; | |
2576 | raw_spin_unlock(&ctx->lock); | |
2577 | } | |
2578 | } | |
2579 | ||
2580 | #define for_each_task_context_nr(ctxn) \ | |
2581 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2582 | ||
2583 | /* | |
2584 | * Called from scheduler to remove the events of the current task, | |
2585 | * with interrupts disabled. | |
2586 | * | |
2587 | * We stop each event and update the event value in event->count. | |
2588 | * | |
2589 | * This does not protect us against NMI, but disable() | |
2590 | * sets the disabled bit in the control field of event _before_ | |
2591 | * accessing the event control register. If a NMI hits, then it will | |
2592 | * not restart the event. | |
2593 | */ | |
2594 | void __perf_event_task_sched_out(struct task_struct *task, | |
2595 | struct task_struct *next) | |
2596 | { | |
2597 | int ctxn; | |
2598 | ||
2599 | for_each_task_context_nr(ctxn) | |
2600 | perf_event_context_sched_out(task, ctxn, next); | |
2601 | ||
2602 | /* | |
2603 | * if cgroup events exist on this CPU, then we need | |
2604 | * to check if we have to switch out PMU state. | |
2605 | * cgroup event are system-wide mode only | |
2606 | */ | |
2607 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2608 | perf_cgroup_sched_out(task, next); | |
2609 | } | |
2610 | ||
2611 | static void task_ctx_sched_out(struct perf_event_context *ctx) | |
2612 | { | |
2613 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
2614 | ||
2615 | if (!cpuctx->task_ctx) | |
2616 | return; | |
2617 | ||
2618 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2619 | return; | |
2620 | ||
2621 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); | |
2622 | cpuctx->task_ctx = NULL; | |
2623 | } | |
2624 | ||
2625 | /* | |
2626 | * Called with IRQs disabled | |
2627 | */ | |
2628 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2629 | enum event_type_t event_type) | |
2630 | { | |
2631 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
2632 | } | |
2633 | ||
2634 | static void | |
2635 | ctx_pinned_sched_in(struct perf_event_context *ctx, | |
2636 | struct perf_cpu_context *cpuctx) | |
2637 | { | |
2638 | struct perf_event *event; | |
2639 | ||
2640 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { | |
2641 | if (event->state <= PERF_EVENT_STATE_OFF) | |
2642 | continue; | |
2643 | if (!event_filter_match(event)) | |
2644 | continue; | |
2645 | ||
2646 | /* may need to reset tstamp_enabled */ | |
2647 | if (is_cgroup_event(event)) | |
2648 | perf_cgroup_mark_enabled(event, ctx); | |
2649 | ||
2650 | if (group_can_go_on(event, cpuctx, 1)) | |
2651 | group_sched_in(event, cpuctx, ctx); | |
2652 | ||
2653 | /* | |
2654 | * If this pinned group hasn't been scheduled, | |
2655 | * put it in error state. | |
2656 | */ | |
2657 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
2658 | update_group_times(event); | |
2659 | event->state = PERF_EVENT_STATE_ERROR; | |
2660 | } | |
2661 | } | |
2662 | } | |
2663 | ||
2664 | static void | |
2665 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
2666 | struct perf_cpu_context *cpuctx) | |
2667 | { | |
2668 | struct perf_event *event; | |
2669 | int can_add_hw = 1; | |
2670 | ||
2671 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { | |
2672 | /* Ignore events in OFF or ERROR state */ | |
2673 | if (event->state <= PERF_EVENT_STATE_OFF) | |
2674 | continue; | |
2675 | /* | |
2676 | * Listen to the 'cpu' scheduling filter constraint | |
2677 | * of events: | |
2678 | */ | |
2679 | if (!event_filter_match(event)) | |
2680 | continue; | |
2681 | ||
2682 | /* may need to reset tstamp_enabled */ | |
2683 | if (is_cgroup_event(event)) | |
2684 | perf_cgroup_mark_enabled(event, ctx); | |
2685 | ||
2686 | if (group_can_go_on(event, cpuctx, can_add_hw)) { | |
2687 | if (group_sched_in(event, cpuctx, ctx)) | |
2688 | can_add_hw = 0; | |
2689 | } | |
2690 | } | |
2691 | } | |
2692 | ||
2693 | static void | |
2694 | ctx_sched_in(struct perf_event_context *ctx, | |
2695 | struct perf_cpu_context *cpuctx, | |
2696 | enum event_type_t event_type, | |
2697 | struct task_struct *task) | |
2698 | { | |
2699 | u64 now; | |
2700 | int is_active = ctx->is_active; | |
2701 | ||
2702 | ctx->is_active |= event_type; | |
2703 | if (likely(!ctx->nr_events)) | |
2704 | return; | |
2705 | ||
2706 | now = perf_clock(); | |
2707 | ctx->timestamp = now; | |
2708 | perf_cgroup_set_timestamp(task, ctx); | |
2709 | /* | |
2710 | * First go through the list and put on any pinned groups | |
2711 | * in order to give them the best chance of going on. | |
2712 | */ | |
2713 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) | |
2714 | ctx_pinned_sched_in(ctx, cpuctx); | |
2715 | ||
2716 | /* Then walk through the lower prio flexible groups */ | |
2717 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) | |
2718 | ctx_flexible_sched_in(ctx, cpuctx); | |
2719 | } | |
2720 | ||
2721 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
2722 | enum event_type_t event_type, | |
2723 | struct task_struct *task) | |
2724 | { | |
2725 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2726 | ||
2727 | ctx_sched_in(ctx, cpuctx, event_type, task); | |
2728 | } | |
2729 | ||
2730 | static void perf_event_context_sched_in(struct perf_event_context *ctx, | |
2731 | struct task_struct *task) | |
2732 | { | |
2733 | struct perf_cpu_context *cpuctx; | |
2734 | ||
2735 | cpuctx = __get_cpu_context(ctx); | |
2736 | if (cpuctx->task_ctx == ctx) | |
2737 | return; | |
2738 | ||
2739 | perf_ctx_lock(cpuctx, ctx); | |
2740 | perf_pmu_disable(ctx->pmu); | |
2741 | /* | |
2742 | * We want to keep the following priority order: | |
2743 | * cpu pinned (that don't need to move), task pinned, | |
2744 | * cpu flexible, task flexible. | |
2745 | */ | |
2746 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2747 | ||
2748 | if (ctx->nr_events) | |
2749 | cpuctx->task_ctx = ctx; | |
2750 | ||
2751 | perf_event_sched_in(cpuctx, cpuctx->task_ctx, task); | |
2752 | ||
2753 | perf_pmu_enable(ctx->pmu); | |
2754 | perf_ctx_unlock(cpuctx, ctx); | |
2755 | } | |
2756 | ||
2757 | /* | |
2758 | * When sampling the branck stack in system-wide, it may be necessary | |
2759 | * to flush the stack on context switch. This happens when the branch | |
2760 | * stack does not tag its entries with the pid of the current task. | |
2761 | * Otherwise it becomes impossible to associate a branch entry with a | |
2762 | * task. This ambiguity is more likely to appear when the branch stack | |
2763 | * supports priv level filtering and the user sets it to monitor only | |
2764 | * at the user level (which could be a useful measurement in system-wide | |
2765 | * mode). In that case, the risk is high of having a branch stack with | |
2766 | * branch from multiple tasks. Flushing may mean dropping the existing | |
2767 | * entries or stashing them somewhere in the PMU specific code layer. | |
2768 | * | |
2769 | * This function provides the context switch callback to the lower code | |
2770 | * layer. It is invoked ONLY when there is at least one system-wide context | |
2771 | * with at least one active event using taken branch sampling. | |
2772 | */ | |
2773 | static void perf_branch_stack_sched_in(struct task_struct *prev, | |
2774 | struct task_struct *task) | |
2775 | { | |
2776 | struct perf_cpu_context *cpuctx; | |
2777 | struct pmu *pmu; | |
2778 | unsigned long flags; | |
2779 | ||
2780 | /* no need to flush branch stack if not changing task */ | |
2781 | if (prev == task) | |
2782 | return; | |
2783 | ||
2784 | local_irq_save(flags); | |
2785 | ||
2786 | rcu_read_lock(); | |
2787 | ||
2788 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2789 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2790 | ||
2791 | /* | |
2792 | * check if the context has at least one | |
2793 | * event using PERF_SAMPLE_BRANCH_STACK | |
2794 | */ | |
2795 | if (cpuctx->ctx.nr_branch_stack > 0 | |
2796 | && pmu->flush_branch_stack) { | |
2797 | ||
2798 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2799 | ||
2800 | perf_pmu_disable(pmu); | |
2801 | ||
2802 | pmu->flush_branch_stack(); | |
2803 | ||
2804 | perf_pmu_enable(pmu); | |
2805 | ||
2806 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2807 | } | |
2808 | } | |
2809 | ||
2810 | rcu_read_unlock(); | |
2811 | ||
2812 | local_irq_restore(flags); | |
2813 | } | |
2814 | ||
2815 | /* | |
2816 | * Called from scheduler to add the events of the current task | |
2817 | * with interrupts disabled. | |
2818 | * | |
2819 | * We restore the event value and then enable it. | |
2820 | * | |
2821 | * This does not protect us against NMI, but enable() | |
2822 | * sets the enabled bit in the control field of event _before_ | |
2823 | * accessing the event control register. If a NMI hits, then it will | |
2824 | * keep the event running. | |
2825 | */ | |
2826 | void __perf_event_task_sched_in(struct task_struct *prev, | |
2827 | struct task_struct *task) | |
2828 | { | |
2829 | struct perf_event_context *ctx; | |
2830 | int ctxn; | |
2831 | ||
2832 | for_each_task_context_nr(ctxn) { | |
2833 | ctx = task->perf_event_ctxp[ctxn]; | |
2834 | if (likely(!ctx)) | |
2835 | continue; | |
2836 | ||
2837 | perf_event_context_sched_in(ctx, task); | |
2838 | } | |
2839 | /* | |
2840 | * if cgroup events exist on this CPU, then we need | |
2841 | * to check if we have to switch in PMU state. | |
2842 | * cgroup event are system-wide mode only | |
2843 | */ | |
2844 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2845 | perf_cgroup_sched_in(prev, task); | |
2846 | ||
2847 | /* check for system-wide branch_stack events */ | |
2848 | if (atomic_read(this_cpu_ptr(&perf_branch_stack_events))) | |
2849 | perf_branch_stack_sched_in(prev, task); | |
2850 | } | |
2851 | ||
2852 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) | |
2853 | { | |
2854 | u64 frequency = event->attr.sample_freq; | |
2855 | u64 sec = NSEC_PER_SEC; | |
2856 | u64 divisor, dividend; | |
2857 | ||
2858 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2859 | ||
2860 | count_fls = fls64(count); | |
2861 | nsec_fls = fls64(nsec); | |
2862 | frequency_fls = fls64(frequency); | |
2863 | sec_fls = 30; | |
2864 | ||
2865 | /* | |
2866 | * We got @count in @nsec, with a target of sample_freq HZ | |
2867 | * the target period becomes: | |
2868 | * | |
2869 | * @count * 10^9 | |
2870 | * period = ------------------- | |
2871 | * @nsec * sample_freq | |
2872 | * | |
2873 | */ | |
2874 | ||
2875 | /* | |
2876 | * Reduce accuracy by one bit such that @a and @b converge | |
2877 | * to a similar magnitude. | |
2878 | */ | |
2879 | #define REDUCE_FLS(a, b) \ | |
2880 | do { \ | |
2881 | if (a##_fls > b##_fls) { \ | |
2882 | a >>= 1; \ | |
2883 | a##_fls--; \ | |
2884 | } else { \ | |
2885 | b >>= 1; \ | |
2886 | b##_fls--; \ | |
2887 | } \ | |
2888 | } while (0) | |
2889 | ||
2890 | /* | |
2891 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2892 | * the other, so that finally we can do a u64/u64 division. | |
2893 | */ | |
2894 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2895 | REDUCE_FLS(nsec, frequency); | |
2896 | REDUCE_FLS(sec, count); | |
2897 | } | |
2898 | ||
2899 | if (count_fls + sec_fls > 64) { | |
2900 | divisor = nsec * frequency; | |
2901 | ||
2902 | while (count_fls + sec_fls > 64) { | |
2903 | REDUCE_FLS(count, sec); | |
2904 | divisor >>= 1; | |
2905 | } | |
2906 | ||
2907 | dividend = count * sec; | |
2908 | } else { | |
2909 | dividend = count * sec; | |
2910 | ||
2911 | while (nsec_fls + frequency_fls > 64) { | |
2912 | REDUCE_FLS(nsec, frequency); | |
2913 | dividend >>= 1; | |
2914 | } | |
2915 | ||
2916 | divisor = nsec * frequency; | |
2917 | } | |
2918 | ||
2919 | if (!divisor) | |
2920 | return dividend; | |
2921 | ||
2922 | return div64_u64(dividend, divisor); | |
2923 | } | |
2924 | ||
2925 | static DEFINE_PER_CPU(int, perf_throttled_count); | |
2926 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2927 | ||
2928 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) | |
2929 | { | |
2930 | struct hw_perf_event *hwc = &event->hw; | |
2931 | s64 period, sample_period; | |
2932 | s64 delta; | |
2933 | ||
2934 | period = perf_calculate_period(event, nsec, count); | |
2935 | ||
2936 | delta = (s64)(period - hwc->sample_period); | |
2937 | delta = (delta + 7) / 8; /* low pass filter */ | |
2938 | ||
2939 | sample_period = hwc->sample_period + delta; | |
2940 | ||
2941 | if (!sample_period) | |
2942 | sample_period = 1; | |
2943 | ||
2944 | hwc->sample_period = sample_period; | |
2945 | ||
2946 | if (local64_read(&hwc->period_left) > 8*sample_period) { | |
2947 | if (disable) | |
2948 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2949 | ||
2950 | local64_set(&hwc->period_left, 0); | |
2951 | ||
2952 | if (disable) | |
2953 | event->pmu->start(event, PERF_EF_RELOAD); | |
2954 | } | |
2955 | } | |
2956 | ||
2957 | /* | |
2958 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2959 | * events. At the same time, make sure, having freq events does not change | |
2960 | * the rate of unthrottling as that would introduce bias. | |
2961 | */ | |
2962 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2963 | int needs_unthr) | |
2964 | { | |
2965 | struct perf_event *event; | |
2966 | struct hw_perf_event *hwc; | |
2967 | u64 now, period = TICK_NSEC; | |
2968 | s64 delta; | |
2969 | ||
2970 | /* | |
2971 | * only need to iterate over all events iff: | |
2972 | * - context have events in frequency mode (needs freq adjust) | |
2973 | * - there are events to unthrottle on this cpu | |
2974 | */ | |
2975 | if (!(ctx->nr_freq || needs_unthr)) | |
2976 | return; | |
2977 | ||
2978 | raw_spin_lock(&ctx->lock); | |
2979 | perf_pmu_disable(ctx->pmu); | |
2980 | ||
2981 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
2982 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
2983 | continue; | |
2984 | ||
2985 | if (!event_filter_match(event)) | |
2986 | continue; | |
2987 | ||
2988 | perf_pmu_disable(event->pmu); | |
2989 | ||
2990 | hwc = &event->hw; | |
2991 | ||
2992 | if (hwc->interrupts == MAX_INTERRUPTS) { | |
2993 | hwc->interrupts = 0; | |
2994 | perf_log_throttle(event, 1); | |
2995 | event->pmu->start(event, 0); | |
2996 | } | |
2997 | ||
2998 | if (!event->attr.freq || !event->attr.sample_freq) | |
2999 | goto next; | |
3000 | ||
3001 | /* | |
3002 | * stop the event and update event->count | |
3003 | */ | |
3004 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3005 | ||
3006 | now = local64_read(&event->count); | |
3007 | delta = now - hwc->freq_count_stamp; | |
3008 | hwc->freq_count_stamp = now; | |
3009 | ||
3010 | /* | |
3011 | * restart the event | |
3012 | * reload only if value has changed | |
3013 | * we have stopped the event so tell that | |
3014 | * to perf_adjust_period() to avoid stopping it | |
3015 | * twice. | |
3016 | */ | |
3017 | if (delta > 0) | |
3018 | perf_adjust_period(event, period, delta, false); | |
3019 | ||
3020 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
3021 | next: | |
3022 | perf_pmu_enable(event->pmu); | |
3023 | } | |
3024 | ||
3025 | perf_pmu_enable(ctx->pmu); | |
3026 | raw_spin_unlock(&ctx->lock); | |
3027 | } | |
3028 | ||
3029 | /* | |
3030 | * Round-robin a context's events: | |
3031 | */ | |
3032 | static void rotate_ctx(struct perf_event_context *ctx) | |
3033 | { | |
3034 | /* | |
3035 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3036 | * disabled by the inheritance code. | |
3037 | */ | |
3038 | if (!ctx->rotate_disable) | |
3039 | list_rotate_left(&ctx->flexible_groups); | |
3040 | } | |
3041 | ||
3042 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) | |
3043 | { | |
3044 | struct perf_event_context *ctx = NULL; | |
3045 | int rotate = 0; | |
3046 | ||
3047 | if (cpuctx->ctx.nr_events) { | |
3048 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) | |
3049 | rotate = 1; | |
3050 | } | |
3051 | ||
3052 | ctx = cpuctx->task_ctx; | |
3053 | if (ctx && ctx->nr_events) { | |
3054 | if (ctx->nr_events != ctx->nr_active) | |
3055 | rotate = 1; | |
3056 | } | |
3057 | ||
3058 | if (!rotate) | |
3059 | goto done; | |
3060 | ||
3061 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
3062 | perf_pmu_disable(cpuctx->ctx.pmu); | |
3063 | ||
3064 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
3065 | if (ctx) | |
3066 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
3067 | ||
3068 | rotate_ctx(&cpuctx->ctx); | |
3069 | if (ctx) | |
3070 | rotate_ctx(ctx); | |
3071 | ||
3072 | perf_event_sched_in(cpuctx, ctx, current); | |
3073 | ||
3074 | perf_pmu_enable(cpuctx->ctx.pmu); | |
3075 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
3076 | done: | |
3077 | ||
3078 | return rotate; | |
3079 | } | |
3080 | ||
3081 | #ifdef CONFIG_NO_HZ_FULL | |
3082 | bool perf_event_can_stop_tick(void) | |
3083 | { | |
3084 | if (atomic_read(&nr_freq_events) || | |
3085 | __this_cpu_read(perf_throttled_count)) | |
3086 | return false; | |
3087 | else | |
3088 | return true; | |
3089 | } | |
3090 | #endif | |
3091 | ||
3092 | void perf_event_task_tick(void) | |
3093 | { | |
3094 | struct list_head *head = this_cpu_ptr(&active_ctx_list); | |
3095 | struct perf_event_context *ctx, *tmp; | |
3096 | int throttled; | |
3097 | ||
3098 | WARN_ON(!irqs_disabled()); | |
3099 | ||
3100 | __this_cpu_inc(perf_throttled_seq); | |
3101 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3102 | ||
3103 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) | |
3104 | perf_adjust_freq_unthr_context(ctx, throttled); | |
3105 | } | |
3106 | ||
3107 | static int event_enable_on_exec(struct perf_event *event, | |
3108 | struct perf_event_context *ctx) | |
3109 | { | |
3110 | if (!event->attr.enable_on_exec) | |
3111 | return 0; | |
3112 | ||
3113 | event->attr.enable_on_exec = 0; | |
3114 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3115 | return 0; | |
3116 | ||
3117 | __perf_event_mark_enabled(event); | |
3118 | ||
3119 | return 1; | |
3120 | } | |
3121 | ||
3122 | /* | |
3123 | * Enable all of a task's events that have been marked enable-on-exec. | |
3124 | * This expects task == current. | |
3125 | */ | |
3126 | static void perf_event_enable_on_exec(struct perf_event_context *ctx) | |
3127 | { | |
3128 | struct perf_event_context *clone_ctx = NULL; | |
3129 | struct perf_event *event; | |
3130 | unsigned long flags; | |
3131 | int enabled = 0; | |
3132 | int ret; | |
3133 | ||
3134 | local_irq_save(flags); | |
3135 | if (!ctx || !ctx->nr_events) | |
3136 | goto out; | |
3137 | ||
3138 | /* | |
3139 | * We must ctxsw out cgroup events to avoid conflict | |
3140 | * when invoking perf_task_event_sched_in() later on | |
3141 | * in this function. Otherwise we end up trying to | |
3142 | * ctxswin cgroup events which are already scheduled | |
3143 | * in. | |
3144 | */ | |
3145 | perf_cgroup_sched_out(current, NULL); | |
3146 | ||
3147 | raw_spin_lock(&ctx->lock); | |
3148 | task_ctx_sched_out(ctx); | |
3149 | ||
3150 | list_for_each_entry(event, &ctx->event_list, event_entry) { | |
3151 | ret = event_enable_on_exec(event, ctx); | |
3152 | if (ret) | |
3153 | enabled = 1; | |
3154 | } | |
3155 | ||
3156 | /* | |
3157 | * Unclone this context if we enabled any event. | |
3158 | */ | |
3159 | if (enabled) | |
3160 | clone_ctx = unclone_ctx(ctx); | |
3161 | ||
3162 | raw_spin_unlock(&ctx->lock); | |
3163 | ||
3164 | /* | |
3165 | * Also calls ctxswin for cgroup events, if any: | |
3166 | */ | |
3167 | perf_event_context_sched_in(ctx, ctx->task); | |
3168 | out: | |
3169 | local_irq_restore(flags); | |
3170 | ||
3171 | if (clone_ctx) | |
3172 | put_ctx(clone_ctx); | |
3173 | } | |
3174 | ||
3175 | void perf_event_exec(void) | |
3176 | { | |
3177 | struct perf_event_context *ctx; | |
3178 | int ctxn; | |
3179 | ||
3180 | rcu_read_lock(); | |
3181 | for_each_task_context_nr(ctxn) { | |
3182 | ctx = current->perf_event_ctxp[ctxn]; | |
3183 | if (!ctx) | |
3184 | continue; | |
3185 | ||
3186 | perf_event_enable_on_exec(ctx); | |
3187 | } | |
3188 | rcu_read_unlock(); | |
3189 | } | |
3190 | ||
3191 | /* | |
3192 | * Cross CPU call to read the hardware event | |
3193 | */ | |
3194 | static void __perf_event_read(void *info) | |
3195 | { | |
3196 | struct perf_event *event = info; | |
3197 | struct perf_event_context *ctx = event->ctx; | |
3198 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
3199 | ||
3200 | /* | |
3201 | * If this is a task context, we need to check whether it is | |
3202 | * the current task context of this cpu. If not it has been | |
3203 | * scheduled out before the smp call arrived. In that case | |
3204 | * event->count would have been updated to a recent sample | |
3205 | * when the event was scheduled out. | |
3206 | */ | |
3207 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3208 | return; | |
3209 | ||
3210 | raw_spin_lock(&ctx->lock); | |
3211 | if (ctx->is_active) { | |
3212 | update_context_time(ctx); | |
3213 | update_cgrp_time_from_event(event); | |
3214 | } | |
3215 | update_event_times(event); | |
3216 | if (event->state == PERF_EVENT_STATE_ACTIVE) | |
3217 | event->pmu->read(event); | |
3218 | raw_spin_unlock(&ctx->lock); | |
3219 | } | |
3220 | ||
3221 | static inline u64 perf_event_count(struct perf_event *event) | |
3222 | { | |
3223 | return local64_read(&event->count) + atomic64_read(&event->child_count); | |
3224 | } | |
3225 | ||
3226 | static u64 perf_event_read(struct perf_event *event) | |
3227 | { | |
3228 | /* | |
3229 | * If event is enabled and currently active on a CPU, update the | |
3230 | * value in the event structure: | |
3231 | */ | |
3232 | if (event->state == PERF_EVENT_STATE_ACTIVE) { | |
3233 | smp_call_function_single(event->oncpu, | |
3234 | __perf_event_read, event, 1); | |
3235 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
3236 | struct perf_event_context *ctx = event->ctx; | |
3237 | unsigned long flags; | |
3238 | ||
3239 | raw_spin_lock_irqsave(&ctx->lock, flags); | |
3240 | /* | |
3241 | * may read while context is not active | |
3242 | * (e.g., thread is blocked), in that case | |
3243 | * we cannot update context time | |
3244 | */ | |
3245 | if (ctx->is_active) { | |
3246 | update_context_time(ctx); | |
3247 | update_cgrp_time_from_event(event); | |
3248 | } | |
3249 | update_event_times(event); | |
3250 | raw_spin_unlock_irqrestore(&ctx->lock, flags); | |
3251 | } | |
3252 | ||
3253 | return perf_event_count(event); | |
3254 | } | |
3255 | ||
3256 | /* | |
3257 | * Initialize the perf_event context in a task_struct: | |
3258 | */ | |
3259 | static void __perf_event_init_context(struct perf_event_context *ctx) | |
3260 | { | |
3261 | raw_spin_lock_init(&ctx->lock); | |
3262 | mutex_init(&ctx->mutex); | |
3263 | INIT_LIST_HEAD(&ctx->active_ctx_list); | |
3264 | INIT_LIST_HEAD(&ctx->pinned_groups); | |
3265 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
3266 | INIT_LIST_HEAD(&ctx->event_list); | |
3267 | atomic_set(&ctx->refcount, 1); | |
3268 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); | |
3269 | } | |
3270 | ||
3271 | static struct perf_event_context * | |
3272 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3273 | { | |
3274 | struct perf_event_context *ctx; | |
3275 | ||
3276 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3277 | if (!ctx) | |
3278 | return NULL; | |
3279 | ||
3280 | __perf_event_init_context(ctx); | |
3281 | if (task) { | |
3282 | ctx->task = task; | |
3283 | get_task_struct(task); | |
3284 | } | |
3285 | ctx->pmu = pmu; | |
3286 | ||
3287 | return ctx; | |
3288 | } | |
3289 | ||
3290 | static struct task_struct * | |
3291 | find_lively_task_by_vpid(pid_t vpid) | |
3292 | { | |
3293 | struct task_struct *task; | |
3294 | int err; | |
3295 | ||
3296 | rcu_read_lock(); | |
3297 | if (!vpid) | |
3298 | task = current; | |
3299 | else | |
3300 | task = find_task_by_vpid(vpid); | |
3301 | if (task) | |
3302 | get_task_struct(task); | |
3303 | rcu_read_unlock(); | |
3304 | ||
3305 | if (!task) | |
3306 | return ERR_PTR(-ESRCH); | |
3307 | ||
3308 | /* Reuse ptrace permission checks for now. */ | |
3309 | err = -EACCES; | |
3310 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3311 | goto errout; | |
3312 | ||
3313 | return task; | |
3314 | errout: | |
3315 | put_task_struct(task); | |
3316 | return ERR_PTR(err); | |
3317 | ||
3318 | } | |
3319 | ||
3320 | /* | |
3321 | * Returns a matching context with refcount and pincount. | |
3322 | */ | |
3323 | static struct perf_event_context * | |
3324 | find_get_context(struct pmu *pmu, struct task_struct *task, int cpu) | |
3325 | { | |
3326 | struct perf_event_context *ctx, *clone_ctx = NULL; | |
3327 | struct perf_cpu_context *cpuctx; | |
3328 | unsigned long flags; | |
3329 | int ctxn, err; | |
3330 | ||
3331 | if (!task) { | |
3332 | /* Must be root to operate on a CPU event: */ | |
3333 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) | |
3334 | return ERR_PTR(-EACCES); | |
3335 | ||
3336 | /* | |
3337 | * We could be clever and allow to attach a event to an | |
3338 | * offline CPU and activate it when the CPU comes up, but | |
3339 | * that's for later. | |
3340 | */ | |
3341 | if (!cpu_online(cpu)) | |
3342 | return ERR_PTR(-ENODEV); | |
3343 | ||
3344 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
3345 | ctx = &cpuctx->ctx; | |
3346 | get_ctx(ctx); | |
3347 | ++ctx->pin_count; | |
3348 | ||
3349 | return ctx; | |
3350 | } | |
3351 | ||
3352 | err = -EINVAL; | |
3353 | ctxn = pmu->task_ctx_nr; | |
3354 | if (ctxn < 0) | |
3355 | goto errout; | |
3356 | ||
3357 | retry: | |
3358 | ctx = perf_lock_task_context(task, ctxn, &flags); | |
3359 | if (ctx) { | |
3360 | clone_ctx = unclone_ctx(ctx); | |
3361 | ++ctx->pin_count; | |
3362 | raw_spin_unlock_irqrestore(&ctx->lock, flags); | |
3363 | ||
3364 | if (clone_ctx) | |
3365 | put_ctx(clone_ctx); | |
3366 | } else { | |
3367 | ctx = alloc_perf_context(pmu, task); | |
3368 | err = -ENOMEM; | |
3369 | if (!ctx) | |
3370 | goto errout; | |
3371 | ||
3372 | err = 0; | |
3373 | mutex_lock(&task->perf_event_mutex); | |
3374 | /* | |
3375 | * If it has already passed perf_event_exit_task(). | |
3376 | * we must see PF_EXITING, it takes this mutex too. | |
3377 | */ | |
3378 | if (task->flags & PF_EXITING) | |
3379 | err = -ESRCH; | |
3380 | else if (task->perf_event_ctxp[ctxn]) | |
3381 | err = -EAGAIN; | |
3382 | else { | |
3383 | get_ctx(ctx); | |
3384 | ++ctx->pin_count; | |
3385 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); | |
3386 | } | |
3387 | mutex_unlock(&task->perf_event_mutex); | |
3388 | ||
3389 | if (unlikely(err)) { | |
3390 | put_ctx(ctx); | |
3391 | ||
3392 | if (err == -EAGAIN) | |
3393 | goto retry; | |
3394 | goto errout; | |
3395 | } | |
3396 | } | |
3397 | ||
3398 | return ctx; | |
3399 | ||
3400 | errout: | |
3401 | return ERR_PTR(err); | |
3402 | } | |
3403 | ||
3404 | static void perf_event_free_filter(struct perf_event *event); | |
3405 | ||
3406 | static void free_event_rcu(struct rcu_head *head) | |
3407 | { | |
3408 | struct perf_event *event; | |
3409 | ||
3410 | event = container_of(head, struct perf_event, rcu_head); | |
3411 | if (event->ns) | |
3412 | put_pid_ns(event->ns); | |
3413 | perf_event_free_filter(event); | |
3414 | kfree(event); | |
3415 | } | |
3416 | ||
3417 | static void ring_buffer_put(struct ring_buffer *rb); | |
3418 | static void ring_buffer_attach(struct perf_event *event, | |
3419 | struct ring_buffer *rb); | |
3420 | ||
3421 | static void unaccount_event_cpu(struct perf_event *event, int cpu) | |
3422 | { | |
3423 | if (event->parent) | |
3424 | return; | |
3425 | ||
3426 | if (has_branch_stack(event)) { | |
3427 | if (!(event->attach_state & PERF_ATTACH_TASK)) | |
3428 | atomic_dec(&per_cpu(perf_branch_stack_events, cpu)); | |
3429 | } | |
3430 | if (is_cgroup_event(event)) | |
3431 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3432 | } | |
3433 | ||
3434 | static void unaccount_event(struct perf_event *event) | |
3435 | { | |
3436 | if (event->parent) | |
3437 | return; | |
3438 | ||
3439 | if (event->attach_state & PERF_ATTACH_TASK) | |
3440 | static_key_slow_dec_deferred(&perf_sched_events); | |
3441 | if (event->attr.mmap || event->attr.mmap_data) | |
3442 | atomic_dec(&nr_mmap_events); | |
3443 | if (event->attr.comm) | |
3444 | atomic_dec(&nr_comm_events); | |
3445 | if (event->attr.task) | |
3446 | atomic_dec(&nr_task_events); | |
3447 | if (event->attr.freq) | |
3448 | atomic_dec(&nr_freq_events); | |
3449 | if (is_cgroup_event(event)) | |
3450 | static_key_slow_dec_deferred(&perf_sched_events); | |
3451 | if (has_branch_stack(event)) | |
3452 | static_key_slow_dec_deferred(&perf_sched_events); | |
3453 | ||
3454 | unaccount_event_cpu(event, event->cpu); | |
3455 | } | |
3456 | ||
3457 | static void __free_event(struct perf_event *event) | |
3458 | { | |
3459 | if (!event->parent) { | |
3460 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3461 | put_callchain_buffers(); | |
3462 | } | |
3463 | ||
3464 | if (event->destroy) | |
3465 | event->destroy(event); | |
3466 | ||
3467 | if (event->ctx) | |
3468 | put_ctx(event->ctx); | |
3469 | ||
3470 | if (event->pmu) | |
3471 | module_put(event->pmu->module); | |
3472 | ||
3473 | call_rcu(&event->rcu_head, free_event_rcu); | |
3474 | } | |
3475 | ||
3476 | static void _free_event(struct perf_event *event) | |
3477 | { | |
3478 | irq_work_sync(&event->pending); | |
3479 | ||
3480 | unaccount_event(event); | |
3481 | ||
3482 | if (event->rb) { | |
3483 | /* | |
3484 | * Can happen when we close an event with re-directed output. | |
3485 | * | |
3486 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3487 | * over us; possibly making our ring_buffer_put() the last. | |
3488 | */ | |
3489 | mutex_lock(&event->mmap_mutex); | |
3490 | ring_buffer_attach(event, NULL); | |
3491 | mutex_unlock(&event->mmap_mutex); | |
3492 | } | |
3493 | ||
3494 | if (is_cgroup_event(event)) | |
3495 | perf_detach_cgroup(event); | |
3496 | ||
3497 | __free_event(event); | |
3498 | } | |
3499 | ||
3500 | /* | |
3501 | * Used to free events which have a known refcount of 1, such as in error paths | |
3502 | * where the event isn't exposed yet and inherited events. | |
3503 | */ | |
3504 | static void free_event(struct perf_event *event) | |
3505 | { | |
3506 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, | |
3507 | "unexpected event refcount: %ld; ptr=%p\n", | |
3508 | atomic_long_read(&event->refcount), event)) { | |
3509 | /* leak to avoid use-after-free */ | |
3510 | return; | |
3511 | } | |
3512 | ||
3513 | _free_event(event); | |
3514 | } | |
3515 | ||
3516 | /* | |
3517 | * Remove user event from the owner task. | |
3518 | */ | |
3519 | static void perf_remove_from_owner(struct perf_event *event) | |
3520 | { | |
3521 | struct task_struct *owner; | |
3522 | ||
3523 | rcu_read_lock(); | |
3524 | owner = ACCESS_ONCE(event->owner); | |
3525 | /* | |
3526 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3527 | * !owner it means the list deletion is complete and we can indeed | |
3528 | * free this event, otherwise we need to serialize on | |
3529 | * owner->perf_event_mutex. | |
3530 | */ | |
3531 | smp_read_barrier_depends(); | |
3532 | if (owner) { | |
3533 | /* | |
3534 | * Since delayed_put_task_struct() also drops the last | |
3535 | * task reference we can safely take a new reference | |
3536 | * while holding the rcu_read_lock(). | |
3537 | */ | |
3538 | get_task_struct(owner); | |
3539 | } | |
3540 | rcu_read_unlock(); | |
3541 | ||
3542 | if (owner) { | |
3543 | /* | |
3544 | * If we're here through perf_event_exit_task() we're already | |
3545 | * holding ctx->mutex which would be an inversion wrt. the | |
3546 | * normal lock order. | |
3547 | * | |
3548 | * However we can safely take this lock because its the child | |
3549 | * ctx->mutex. | |
3550 | */ | |
3551 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3552 | ||
3553 | /* | |
3554 | * We have to re-check the event->owner field, if it is cleared | |
3555 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3556 | * ensured they're done, and we can proceed with freeing the | |
3557 | * event. | |
3558 | */ | |
3559 | if (event->owner) | |
3560 | list_del_init(&event->owner_entry); | |
3561 | mutex_unlock(&owner->perf_event_mutex); | |
3562 | put_task_struct(owner); | |
3563 | } | |
3564 | } | |
3565 | ||
3566 | /* | |
3567 | * Called when the last reference to the file is gone. | |
3568 | */ | |
3569 | static void put_event(struct perf_event *event) | |
3570 | { | |
3571 | struct perf_event_context *ctx; | |
3572 | ||
3573 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3574 | return; | |
3575 | ||
3576 | if (!is_kernel_event(event)) | |
3577 | perf_remove_from_owner(event); | |
3578 | ||
3579 | /* | |
3580 | * There are two ways this annotation is useful: | |
3581 | * | |
3582 | * 1) there is a lock recursion from perf_event_exit_task | |
3583 | * see the comment there. | |
3584 | * | |
3585 | * 2) there is a lock-inversion with mmap_sem through | |
3586 | * perf_event_read_group(), which takes faults while | |
3587 | * holding ctx->mutex, however this is called after | |
3588 | * the last filedesc died, so there is no possibility | |
3589 | * to trigger the AB-BA case. | |
3590 | */ | |
3591 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); | |
3592 | WARN_ON_ONCE(ctx->parent_ctx); | |
3593 | perf_remove_from_context(event, true); | |
3594 | mutex_unlock(&ctx->mutex); | |
3595 | ||
3596 | _free_event(event); | |
3597 | } | |
3598 | ||
3599 | int perf_event_release_kernel(struct perf_event *event) | |
3600 | { | |
3601 | put_event(event); | |
3602 | return 0; | |
3603 | } | |
3604 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3605 | ||
3606 | static int perf_release(struct inode *inode, struct file *file) | |
3607 | { | |
3608 | put_event(file->private_data); | |
3609 | return 0; | |
3610 | } | |
3611 | ||
3612 | /* | |
3613 | * Remove all orphanes events from the context. | |
3614 | */ | |
3615 | static void orphans_remove_work(struct work_struct *work) | |
3616 | { | |
3617 | struct perf_event_context *ctx; | |
3618 | struct perf_event *event, *tmp; | |
3619 | ||
3620 | ctx = container_of(work, struct perf_event_context, | |
3621 | orphans_remove.work); | |
3622 | ||
3623 | mutex_lock(&ctx->mutex); | |
3624 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3625 | struct perf_event *parent_event = event->parent; | |
3626 | ||
3627 | if (!is_orphaned_child(event)) | |
3628 | continue; | |
3629 | ||
3630 | perf_remove_from_context(event, true); | |
3631 | ||
3632 | mutex_lock(&parent_event->child_mutex); | |
3633 | list_del_init(&event->child_list); | |
3634 | mutex_unlock(&parent_event->child_mutex); | |
3635 | ||
3636 | free_event(event); | |
3637 | put_event(parent_event); | |
3638 | } | |
3639 | ||
3640 | raw_spin_lock_irq(&ctx->lock); | |
3641 | ctx->orphans_remove_sched = false; | |
3642 | raw_spin_unlock_irq(&ctx->lock); | |
3643 | mutex_unlock(&ctx->mutex); | |
3644 | ||
3645 | put_ctx(ctx); | |
3646 | } | |
3647 | ||
3648 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) | |
3649 | { | |
3650 | struct perf_event *child; | |
3651 | u64 total = 0; | |
3652 | ||
3653 | *enabled = 0; | |
3654 | *running = 0; | |
3655 | ||
3656 | mutex_lock(&event->child_mutex); | |
3657 | total += perf_event_read(event); | |
3658 | *enabled += event->total_time_enabled + | |
3659 | atomic64_read(&event->child_total_time_enabled); | |
3660 | *running += event->total_time_running + | |
3661 | atomic64_read(&event->child_total_time_running); | |
3662 | ||
3663 | list_for_each_entry(child, &event->child_list, child_list) { | |
3664 | total += perf_event_read(child); | |
3665 | *enabled += child->total_time_enabled; | |
3666 | *running += child->total_time_running; | |
3667 | } | |
3668 | mutex_unlock(&event->child_mutex); | |
3669 | ||
3670 | return total; | |
3671 | } | |
3672 | EXPORT_SYMBOL_GPL(perf_event_read_value); | |
3673 | ||
3674 | static int perf_event_read_group(struct perf_event *event, | |
3675 | u64 read_format, char __user *buf) | |
3676 | { | |
3677 | struct perf_event *leader = event->group_leader, *sub; | |
3678 | struct perf_event_context *ctx = leader->ctx; | |
3679 | int n = 0, size = 0, ret; | |
3680 | u64 count, enabled, running; | |
3681 | u64 values[5]; | |
3682 | ||
3683 | lockdep_assert_held(&ctx->mutex); | |
3684 | ||
3685 | count = perf_event_read_value(leader, &enabled, &running); | |
3686 | ||
3687 | values[n++] = 1 + leader->nr_siblings; | |
3688 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3689 | values[n++] = enabled; | |
3690 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3691 | values[n++] = running; | |
3692 | values[n++] = count; | |
3693 | if (read_format & PERF_FORMAT_ID) | |
3694 | values[n++] = primary_event_id(leader); | |
3695 | ||
3696 | size = n * sizeof(u64); | |
3697 | ||
3698 | if (copy_to_user(buf, values, size)) | |
3699 | return -EFAULT; | |
3700 | ||
3701 | ret = size; | |
3702 | ||
3703 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { | |
3704 | n = 0; | |
3705 | ||
3706 | values[n++] = perf_event_read_value(sub, &enabled, &running); | |
3707 | if (read_format & PERF_FORMAT_ID) | |
3708 | values[n++] = primary_event_id(sub); | |
3709 | ||
3710 | size = n * sizeof(u64); | |
3711 | ||
3712 | if (copy_to_user(buf + ret, values, size)) { | |
3713 | return -EFAULT; | |
3714 | } | |
3715 | ||
3716 | ret += size; | |
3717 | } | |
3718 | ||
3719 | return ret; | |
3720 | } | |
3721 | ||
3722 | static int perf_event_read_one(struct perf_event *event, | |
3723 | u64 read_format, char __user *buf) | |
3724 | { | |
3725 | u64 enabled, running; | |
3726 | u64 values[4]; | |
3727 | int n = 0; | |
3728 | ||
3729 | values[n++] = perf_event_read_value(event, &enabled, &running); | |
3730 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3731 | values[n++] = enabled; | |
3732 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3733 | values[n++] = running; | |
3734 | if (read_format & PERF_FORMAT_ID) | |
3735 | values[n++] = primary_event_id(event); | |
3736 | ||
3737 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3738 | return -EFAULT; | |
3739 | ||
3740 | return n * sizeof(u64); | |
3741 | } | |
3742 | ||
3743 | static bool is_event_hup(struct perf_event *event) | |
3744 | { | |
3745 | bool no_children; | |
3746 | ||
3747 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3748 | return false; | |
3749 | ||
3750 | mutex_lock(&event->child_mutex); | |
3751 | no_children = list_empty(&event->child_list); | |
3752 | mutex_unlock(&event->child_mutex); | |
3753 | return no_children; | |
3754 | } | |
3755 | ||
3756 | /* | |
3757 | * Read the performance event - simple non blocking version for now | |
3758 | */ | |
3759 | static ssize_t | |
3760 | perf_read_hw(struct perf_event *event, char __user *buf, size_t count) | |
3761 | { | |
3762 | u64 read_format = event->attr.read_format; | |
3763 | int ret; | |
3764 | ||
3765 | /* | |
3766 | * Return end-of-file for a read on a event that is in | |
3767 | * error state (i.e. because it was pinned but it couldn't be | |
3768 | * scheduled on to the CPU at some point). | |
3769 | */ | |
3770 | if (event->state == PERF_EVENT_STATE_ERROR) | |
3771 | return 0; | |
3772 | ||
3773 | if (count < event->read_size) | |
3774 | return -ENOSPC; | |
3775 | ||
3776 | WARN_ON_ONCE(event->ctx->parent_ctx); | |
3777 | if (read_format & PERF_FORMAT_GROUP) | |
3778 | ret = perf_event_read_group(event, read_format, buf); | |
3779 | else | |
3780 | ret = perf_event_read_one(event, read_format, buf); | |
3781 | ||
3782 | return ret; | |
3783 | } | |
3784 | ||
3785 | static ssize_t | |
3786 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
3787 | { | |
3788 | struct perf_event *event = file->private_data; | |
3789 | struct perf_event_context *ctx; | |
3790 | int ret; | |
3791 | ||
3792 | ctx = perf_event_ctx_lock(event); | |
3793 | ret = perf_read_hw(event, buf, count); | |
3794 | perf_event_ctx_unlock(event, ctx); | |
3795 | ||
3796 | return ret; | |
3797 | } | |
3798 | ||
3799 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
3800 | { | |
3801 | struct perf_event *event = file->private_data; | |
3802 | struct ring_buffer *rb; | |
3803 | unsigned int events = POLLHUP; | |
3804 | ||
3805 | poll_wait(file, &event->waitq, wait); | |
3806 | ||
3807 | if (is_event_hup(event)) | |
3808 | return events; | |
3809 | ||
3810 | /* | |
3811 | * Pin the event->rb by taking event->mmap_mutex; otherwise | |
3812 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
3813 | */ | |
3814 | mutex_lock(&event->mmap_mutex); | |
3815 | rb = event->rb; | |
3816 | if (rb) | |
3817 | events = atomic_xchg(&rb->poll, 0); | |
3818 | mutex_unlock(&event->mmap_mutex); | |
3819 | return events; | |
3820 | } | |
3821 | ||
3822 | static void _perf_event_reset(struct perf_event *event) | |
3823 | { | |
3824 | (void)perf_event_read(event); | |
3825 | local64_set(&event->count, 0); | |
3826 | perf_event_update_userpage(event); | |
3827 | } | |
3828 | ||
3829 | /* | |
3830 | * Holding the top-level event's child_mutex means that any | |
3831 | * descendant process that has inherited this event will block | |
3832 | * in sync_child_event if it goes to exit, thus satisfying the | |
3833 | * task existence requirements of perf_event_enable/disable. | |
3834 | */ | |
3835 | static void perf_event_for_each_child(struct perf_event *event, | |
3836 | void (*func)(struct perf_event *)) | |
3837 | { | |
3838 | struct perf_event *child; | |
3839 | ||
3840 | WARN_ON_ONCE(event->ctx->parent_ctx); | |
3841 | ||
3842 | mutex_lock(&event->child_mutex); | |
3843 | func(event); | |
3844 | list_for_each_entry(child, &event->child_list, child_list) | |
3845 | func(child); | |
3846 | mutex_unlock(&event->child_mutex); | |
3847 | } | |
3848 | ||
3849 | static void perf_event_for_each(struct perf_event *event, | |
3850 | void (*func)(struct perf_event *)) | |
3851 | { | |
3852 | struct perf_event_context *ctx = event->ctx; | |
3853 | struct perf_event *sibling; | |
3854 | ||
3855 | lockdep_assert_held(&ctx->mutex); | |
3856 | ||
3857 | event = event->group_leader; | |
3858 | ||
3859 | perf_event_for_each_child(event, func); | |
3860 | list_for_each_entry(sibling, &event->sibling_list, group_entry) | |
3861 | perf_event_for_each_child(sibling, func); | |
3862 | } | |
3863 | ||
3864 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
3865 | { | |
3866 | struct perf_event_context *ctx = event->ctx; | |
3867 | int ret = 0, active; | |
3868 | u64 value; | |
3869 | ||
3870 | if (!is_sampling_event(event)) | |
3871 | return -EINVAL; | |
3872 | ||
3873 | if (copy_from_user(&value, arg, sizeof(value))) | |
3874 | return -EFAULT; | |
3875 | ||
3876 | if (!value) | |
3877 | return -EINVAL; | |
3878 | ||
3879 | raw_spin_lock_irq(&ctx->lock); | |
3880 | if (event->attr.freq) { | |
3881 | if (value > sysctl_perf_event_sample_rate) { | |
3882 | ret = -EINVAL; | |
3883 | goto unlock; | |
3884 | } | |
3885 | ||
3886 | event->attr.sample_freq = value; | |
3887 | } else { | |
3888 | event->attr.sample_period = value; | |
3889 | event->hw.sample_period = value; | |
3890 | } | |
3891 | ||
3892 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
3893 | if (active) { | |
3894 | perf_pmu_disable(ctx->pmu); | |
3895 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3896 | } | |
3897 | ||
3898 | local64_set(&event->hw.period_left, 0); | |
3899 | ||
3900 | if (active) { | |
3901 | event->pmu->start(event, PERF_EF_RELOAD); | |
3902 | perf_pmu_enable(ctx->pmu); | |
3903 | } | |
3904 | ||
3905 | unlock: | |
3906 | raw_spin_unlock_irq(&ctx->lock); | |
3907 | ||
3908 | return ret; | |
3909 | } | |
3910 | ||
3911 | static const struct file_operations perf_fops; | |
3912 | ||
3913 | static inline int perf_fget_light(int fd, struct fd *p) | |
3914 | { | |
3915 | struct fd f = fdget(fd); | |
3916 | if (!f.file) | |
3917 | return -EBADF; | |
3918 | ||
3919 | if (f.file->f_op != &perf_fops) { | |
3920 | fdput(f); | |
3921 | return -EBADF; | |
3922 | } | |
3923 | *p = f; | |
3924 | return 0; | |
3925 | } | |
3926 | ||
3927 | static int perf_event_set_output(struct perf_event *event, | |
3928 | struct perf_event *output_event); | |
3929 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); | |
3930 | ||
3931 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) | |
3932 | { | |
3933 | void (*func)(struct perf_event *); | |
3934 | u32 flags = arg; | |
3935 | ||
3936 | switch (cmd) { | |
3937 | case PERF_EVENT_IOC_ENABLE: | |
3938 | func = _perf_event_enable; | |
3939 | break; | |
3940 | case PERF_EVENT_IOC_DISABLE: | |
3941 | func = _perf_event_disable; | |
3942 | break; | |
3943 | case PERF_EVENT_IOC_RESET: | |
3944 | func = _perf_event_reset; | |
3945 | break; | |
3946 | ||
3947 | case PERF_EVENT_IOC_REFRESH: | |
3948 | return _perf_event_refresh(event, arg); | |
3949 | ||
3950 | case PERF_EVENT_IOC_PERIOD: | |
3951 | return perf_event_period(event, (u64 __user *)arg); | |
3952 | ||
3953 | case PERF_EVENT_IOC_ID: | |
3954 | { | |
3955 | u64 id = primary_event_id(event); | |
3956 | ||
3957 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
3958 | return -EFAULT; | |
3959 | return 0; | |
3960 | } | |
3961 | ||
3962 | case PERF_EVENT_IOC_SET_OUTPUT: | |
3963 | { | |
3964 | int ret; | |
3965 | if (arg != -1) { | |
3966 | struct perf_event *output_event; | |
3967 | struct fd output; | |
3968 | ret = perf_fget_light(arg, &output); | |
3969 | if (ret) | |
3970 | return ret; | |
3971 | output_event = output.file->private_data; | |
3972 | ret = perf_event_set_output(event, output_event); | |
3973 | fdput(output); | |
3974 | } else { | |
3975 | ret = perf_event_set_output(event, NULL); | |
3976 | } | |
3977 | return ret; | |
3978 | } | |
3979 | ||
3980 | case PERF_EVENT_IOC_SET_FILTER: | |
3981 | return perf_event_set_filter(event, (void __user *)arg); | |
3982 | ||
3983 | default: | |
3984 | return -ENOTTY; | |
3985 | } | |
3986 | ||
3987 | if (flags & PERF_IOC_FLAG_GROUP) | |
3988 | perf_event_for_each(event, func); | |
3989 | else | |
3990 | perf_event_for_each_child(event, func); | |
3991 | ||
3992 | return 0; | |
3993 | } | |
3994 | ||
3995 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
3996 | { | |
3997 | struct perf_event *event = file->private_data; | |
3998 | struct perf_event_context *ctx; | |
3999 | long ret; | |
4000 | ||
4001 | ctx = perf_event_ctx_lock(event); | |
4002 | ret = _perf_ioctl(event, cmd, arg); | |
4003 | perf_event_ctx_unlock(event, ctx); | |
4004 | ||
4005 | return ret; | |
4006 | } | |
4007 | ||
4008 | #ifdef CONFIG_COMPAT | |
4009 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4010 | unsigned long arg) | |
4011 | { | |
4012 | switch (_IOC_NR(cmd)) { | |
4013 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4014 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4015 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4016 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4017 | cmd &= ~IOCSIZE_MASK; | |
4018 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4019 | } | |
4020 | break; | |
4021 | } | |
4022 | return perf_ioctl(file, cmd, arg); | |
4023 | } | |
4024 | #else | |
4025 | # define perf_compat_ioctl NULL | |
4026 | #endif | |
4027 | ||
4028 | int perf_event_task_enable(void) | |
4029 | { | |
4030 | struct perf_event_context *ctx; | |
4031 | struct perf_event *event; | |
4032 | ||
4033 | mutex_lock(¤t->perf_event_mutex); | |
4034 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { | |
4035 | ctx = perf_event_ctx_lock(event); | |
4036 | perf_event_for_each_child(event, _perf_event_enable); | |
4037 | perf_event_ctx_unlock(event, ctx); | |
4038 | } | |
4039 | mutex_unlock(¤t->perf_event_mutex); | |
4040 | ||
4041 | return 0; | |
4042 | } | |
4043 | ||
4044 | int perf_event_task_disable(void) | |
4045 | { | |
4046 | struct perf_event_context *ctx; | |
4047 | struct perf_event *event; | |
4048 | ||
4049 | mutex_lock(¤t->perf_event_mutex); | |
4050 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { | |
4051 | ctx = perf_event_ctx_lock(event); | |
4052 | perf_event_for_each_child(event, _perf_event_disable); | |
4053 | perf_event_ctx_unlock(event, ctx); | |
4054 | } | |
4055 | mutex_unlock(¤t->perf_event_mutex); | |
4056 | ||
4057 | return 0; | |
4058 | } | |
4059 | ||
4060 | static int perf_event_index(struct perf_event *event) | |
4061 | { | |
4062 | if (event->hw.state & PERF_HES_STOPPED) | |
4063 | return 0; | |
4064 | ||
4065 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
4066 | return 0; | |
4067 | ||
4068 | return event->pmu->event_idx(event); | |
4069 | } | |
4070 | ||
4071 | static void calc_timer_values(struct perf_event *event, | |
4072 | u64 *now, | |
4073 | u64 *enabled, | |
4074 | u64 *running) | |
4075 | { | |
4076 | u64 ctx_time; | |
4077 | ||
4078 | *now = perf_clock(); | |
4079 | ctx_time = event->shadow_ctx_time + *now; | |
4080 | *enabled = ctx_time - event->tstamp_enabled; | |
4081 | *running = ctx_time - event->tstamp_running; | |
4082 | } | |
4083 | ||
4084 | static void perf_event_init_userpage(struct perf_event *event) | |
4085 | { | |
4086 | struct perf_event_mmap_page *userpg; | |
4087 | struct ring_buffer *rb; | |
4088 | ||
4089 | rcu_read_lock(); | |
4090 | rb = rcu_dereference(event->rb); | |
4091 | if (!rb) | |
4092 | goto unlock; | |
4093 | ||
4094 | userpg = rb->user_page; | |
4095 | ||
4096 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4097 | userpg->cap_bit0_is_deprecated = 1; | |
4098 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
4099 | ||
4100 | unlock: | |
4101 | rcu_read_unlock(); | |
4102 | } | |
4103 | ||
4104 | void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now) | |
4105 | { | |
4106 | } | |
4107 | ||
4108 | /* | |
4109 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4110 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4111 | * code calls this from NMI context. | |
4112 | */ | |
4113 | void perf_event_update_userpage(struct perf_event *event) | |
4114 | { | |
4115 | struct perf_event_mmap_page *userpg; | |
4116 | struct ring_buffer *rb; | |
4117 | u64 enabled, running, now; | |
4118 | ||
4119 | rcu_read_lock(); | |
4120 | rb = rcu_dereference(event->rb); | |
4121 | if (!rb) | |
4122 | goto unlock; | |
4123 | ||
4124 | /* | |
4125 | * compute total_time_enabled, total_time_running | |
4126 | * based on snapshot values taken when the event | |
4127 | * was last scheduled in. | |
4128 | * | |
4129 | * we cannot simply called update_context_time() | |
4130 | * because of locking issue as we can be called in | |
4131 | * NMI context | |
4132 | */ | |
4133 | calc_timer_values(event, &now, &enabled, &running); | |
4134 | ||
4135 | userpg = rb->user_page; | |
4136 | /* | |
4137 | * Disable preemption so as to not let the corresponding user-space | |
4138 | * spin too long if we get preempted. | |
4139 | */ | |
4140 | preempt_disable(); | |
4141 | ++userpg->lock; | |
4142 | barrier(); | |
4143 | userpg->index = perf_event_index(event); | |
4144 | userpg->offset = perf_event_count(event); | |
4145 | if (userpg->index) | |
4146 | userpg->offset -= local64_read(&event->hw.prev_count); | |
4147 | ||
4148 | userpg->time_enabled = enabled + | |
4149 | atomic64_read(&event->child_total_time_enabled); | |
4150 | ||
4151 | userpg->time_running = running + | |
4152 | atomic64_read(&event->child_total_time_running); | |
4153 | ||
4154 | arch_perf_update_userpage(userpg, now); | |
4155 | ||
4156 | barrier(); | |
4157 | ++userpg->lock; | |
4158 | preempt_enable(); | |
4159 | unlock: | |
4160 | rcu_read_unlock(); | |
4161 | } | |
4162 | ||
4163 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
4164 | { | |
4165 | struct perf_event *event = vma->vm_file->private_data; | |
4166 | struct ring_buffer *rb; | |
4167 | int ret = VM_FAULT_SIGBUS; | |
4168 | ||
4169 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4170 | if (vmf->pgoff == 0) | |
4171 | ret = 0; | |
4172 | return ret; | |
4173 | } | |
4174 | ||
4175 | rcu_read_lock(); | |
4176 | rb = rcu_dereference(event->rb); | |
4177 | if (!rb) | |
4178 | goto unlock; | |
4179 | ||
4180 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4181 | goto unlock; | |
4182 | ||
4183 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); | |
4184 | if (!vmf->page) | |
4185 | goto unlock; | |
4186 | ||
4187 | get_page(vmf->page); | |
4188 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4189 | vmf->page->index = vmf->pgoff; | |
4190 | ||
4191 | ret = 0; | |
4192 | unlock: | |
4193 | rcu_read_unlock(); | |
4194 | ||
4195 | return ret; | |
4196 | } | |
4197 | ||
4198 | static void ring_buffer_attach(struct perf_event *event, | |
4199 | struct ring_buffer *rb) | |
4200 | { | |
4201 | struct ring_buffer *old_rb = NULL; | |
4202 | unsigned long flags; | |
4203 | ||
4204 | if (event->rb) { | |
4205 | /* | |
4206 | * Should be impossible, we set this when removing | |
4207 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4208 | */ | |
4209 | WARN_ON_ONCE(event->rcu_pending); | |
4210 | ||
4211 | old_rb = event->rb; | |
4212 | event->rcu_batches = get_state_synchronize_rcu(); | |
4213 | event->rcu_pending = 1; | |
4214 | ||
4215 | spin_lock_irqsave(&old_rb->event_lock, flags); | |
4216 | list_del_rcu(&event->rb_entry); | |
4217 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
4218 | } | |
4219 | ||
4220 | if (event->rcu_pending && rb) { | |
4221 | cond_synchronize_rcu(event->rcu_batches); | |
4222 | event->rcu_pending = 0; | |
4223 | } | |
4224 | ||
4225 | if (rb) { | |
4226 | spin_lock_irqsave(&rb->event_lock, flags); | |
4227 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4228 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4229 | } | |
4230 | ||
4231 | rcu_assign_pointer(event->rb, rb); | |
4232 | ||
4233 | if (old_rb) { | |
4234 | ring_buffer_put(old_rb); | |
4235 | /* | |
4236 | * Since we detached before setting the new rb, so that we | |
4237 | * could attach the new rb, we could have missed a wakeup. | |
4238 | * Provide it now. | |
4239 | */ | |
4240 | wake_up_all(&event->waitq); | |
4241 | } | |
4242 | } | |
4243 | ||
4244 | static void ring_buffer_wakeup(struct perf_event *event) | |
4245 | { | |
4246 | struct ring_buffer *rb; | |
4247 | ||
4248 | rcu_read_lock(); | |
4249 | rb = rcu_dereference(event->rb); | |
4250 | if (rb) { | |
4251 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4252 | wake_up_all(&event->waitq); | |
4253 | } | |
4254 | rcu_read_unlock(); | |
4255 | } | |
4256 | ||
4257 | static void rb_free_rcu(struct rcu_head *rcu_head) | |
4258 | { | |
4259 | struct ring_buffer *rb; | |
4260 | ||
4261 | rb = container_of(rcu_head, struct ring_buffer, rcu_head); | |
4262 | rb_free(rb); | |
4263 | } | |
4264 | ||
4265 | static struct ring_buffer *ring_buffer_get(struct perf_event *event) | |
4266 | { | |
4267 | struct ring_buffer *rb; | |
4268 | ||
4269 | rcu_read_lock(); | |
4270 | rb = rcu_dereference(event->rb); | |
4271 | if (rb) { | |
4272 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4273 | rb = NULL; | |
4274 | } | |
4275 | rcu_read_unlock(); | |
4276 | ||
4277 | return rb; | |
4278 | } | |
4279 | ||
4280 | static void ring_buffer_put(struct ring_buffer *rb) | |
4281 | { | |
4282 | if (!atomic_dec_and_test(&rb->refcount)) | |
4283 | return; | |
4284 | ||
4285 | WARN_ON_ONCE(!list_empty(&rb->event_list)); | |
4286 | ||
4287 | call_rcu(&rb->rcu_head, rb_free_rcu); | |
4288 | } | |
4289 | ||
4290 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4291 | { | |
4292 | struct perf_event *event = vma->vm_file->private_data; | |
4293 | ||
4294 | atomic_inc(&event->mmap_count); | |
4295 | atomic_inc(&event->rb->mmap_count); | |
4296 | ||
4297 | if (event->pmu->event_mapped) | |
4298 | event->pmu->event_mapped(event); | |
4299 | } | |
4300 | ||
4301 | /* | |
4302 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4303 | * event, or through other events by use of perf_event_set_output(). | |
4304 | * | |
4305 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4306 | * the buffer here, where we still have a VM context. This means we need | |
4307 | * to detach all events redirecting to us. | |
4308 | */ | |
4309 | static void perf_mmap_close(struct vm_area_struct *vma) | |
4310 | { | |
4311 | struct perf_event *event = vma->vm_file->private_data; | |
4312 | ||
4313 | struct ring_buffer *rb = ring_buffer_get(event); | |
4314 | struct user_struct *mmap_user = rb->mmap_user; | |
4315 | int mmap_locked = rb->mmap_locked; | |
4316 | unsigned long size = perf_data_size(rb); | |
4317 | ||
4318 | if (event->pmu->event_unmapped) | |
4319 | event->pmu->event_unmapped(event); | |
4320 | ||
4321 | atomic_dec(&rb->mmap_count); | |
4322 | ||
4323 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
4324 | goto out_put; | |
4325 | ||
4326 | ring_buffer_attach(event, NULL); | |
4327 | mutex_unlock(&event->mmap_mutex); | |
4328 | ||
4329 | /* If there's still other mmap()s of this buffer, we're done. */ | |
4330 | if (atomic_read(&rb->mmap_count)) | |
4331 | goto out_put; | |
4332 | ||
4333 | /* | |
4334 | * No other mmap()s, detach from all other events that might redirect | |
4335 | * into the now unreachable buffer. Somewhat complicated by the | |
4336 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4337 | */ | |
4338 | again: | |
4339 | rcu_read_lock(); | |
4340 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4341 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4342 | /* | |
4343 | * This event is en-route to free_event() which will | |
4344 | * detach it and remove it from the list. | |
4345 | */ | |
4346 | continue; | |
4347 | } | |
4348 | rcu_read_unlock(); | |
4349 | ||
4350 | mutex_lock(&event->mmap_mutex); | |
4351 | /* | |
4352 | * Check we didn't race with perf_event_set_output() which can | |
4353 | * swizzle the rb from under us while we were waiting to | |
4354 | * acquire mmap_mutex. | |
4355 | * | |
4356 | * If we find a different rb; ignore this event, a next | |
4357 | * iteration will no longer find it on the list. We have to | |
4358 | * still restart the iteration to make sure we're not now | |
4359 | * iterating the wrong list. | |
4360 | */ | |
4361 | if (event->rb == rb) | |
4362 | ring_buffer_attach(event, NULL); | |
4363 | ||
4364 | mutex_unlock(&event->mmap_mutex); | |
4365 | put_event(event); | |
4366 | ||
4367 | /* | |
4368 | * Restart the iteration; either we're on the wrong list or | |
4369 | * destroyed its integrity by doing a deletion. | |
4370 | */ | |
4371 | goto again; | |
4372 | } | |
4373 | rcu_read_unlock(); | |
4374 | ||
4375 | /* | |
4376 | * It could be there's still a few 0-ref events on the list; they'll | |
4377 | * get cleaned up by free_event() -- they'll also still have their | |
4378 | * ref on the rb and will free it whenever they are done with it. | |
4379 | * | |
4380 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4381 | * undo the VM accounting. | |
4382 | */ | |
4383 | ||
4384 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4385 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4386 | free_uid(mmap_user); | |
4387 | ||
4388 | out_put: | |
4389 | ring_buffer_put(rb); /* could be last */ | |
4390 | } | |
4391 | ||
4392 | static const struct vm_operations_struct perf_mmap_vmops = { | |
4393 | .open = perf_mmap_open, | |
4394 | .close = perf_mmap_close, | |
4395 | .fault = perf_mmap_fault, | |
4396 | .page_mkwrite = perf_mmap_fault, | |
4397 | }; | |
4398 | ||
4399 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4400 | { | |
4401 | struct perf_event *event = file->private_data; | |
4402 | unsigned long user_locked, user_lock_limit; | |
4403 | struct user_struct *user = current_user(); | |
4404 | unsigned long locked, lock_limit; | |
4405 | struct ring_buffer *rb; | |
4406 | unsigned long vma_size; | |
4407 | unsigned long nr_pages; | |
4408 | long user_extra, extra; | |
4409 | int ret = 0, flags = 0; | |
4410 | ||
4411 | /* | |
4412 | * Don't allow mmap() of inherited per-task counters. This would | |
4413 | * create a performance issue due to all children writing to the | |
4414 | * same rb. | |
4415 | */ | |
4416 | if (event->cpu == -1 && event->attr.inherit) | |
4417 | return -EINVAL; | |
4418 | ||
4419 | if (!(vma->vm_flags & VM_SHARED)) | |
4420 | return -EINVAL; | |
4421 | ||
4422 | vma_size = vma->vm_end - vma->vm_start; | |
4423 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4424 | ||
4425 | /* | |
4426 | * If we have rb pages ensure they're a power-of-two number, so we | |
4427 | * can do bitmasks instead of modulo. | |
4428 | */ | |
4429 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) | |
4430 | return -EINVAL; | |
4431 | ||
4432 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) | |
4433 | return -EINVAL; | |
4434 | ||
4435 | if (vma->vm_pgoff != 0) | |
4436 | return -EINVAL; | |
4437 | ||
4438 | WARN_ON_ONCE(event->ctx->parent_ctx); | |
4439 | again: | |
4440 | mutex_lock(&event->mmap_mutex); | |
4441 | if (event->rb) { | |
4442 | if (event->rb->nr_pages != nr_pages) { | |
4443 | ret = -EINVAL; | |
4444 | goto unlock; | |
4445 | } | |
4446 | ||
4447 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4448 | /* | |
4449 | * Raced against perf_mmap_close() through | |
4450 | * perf_event_set_output(). Try again, hope for better | |
4451 | * luck. | |
4452 | */ | |
4453 | mutex_unlock(&event->mmap_mutex); | |
4454 | goto again; | |
4455 | } | |
4456 | ||
4457 | goto unlock; | |
4458 | } | |
4459 | ||
4460 | user_extra = nr_pages + 1; | |
4461 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); | |
4462 | ||
4463 | /* | |
4464 | * Increase the limit linearly with more CPUs: | |
4465 | */ | |
4466 | user_lock_limit *= num_online_cpus(); | |
4467 | ||
4468 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; | |
4469 | ||
4470 | extra = 0; | |
4471 | if (user_locked > user_lock_limit) | |
4472 | extra = user_locked - user_lock_limit; | |
4473 | ||
4474 | lock_limit = rlimit(RLIMIT_MEMLOCK); | |
4475 | lock_limit >>= PAGE_SHIFT; | |
4476 | locked = vma->vm_mm->pinned_vm + extra; | |
4477 | ||
4478 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && | |
4479 | !capable(CAP_IPC_LOCK)) { | |
4480 | ret = -EPERM; | |
4481 | goto unlock; | |
4482 | } | |
4483 | ||
4484 | WARN_ON(event->rb); | |
4485 | ||
4486 | if (vma->vm_flags & VM_WRITE) | |
4487 | flags |= RING_BUFFER_WRITABLE; | |
4488 | ||
4489 | rb = rb_alloc(nr_pages, | |
4490 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4491 | event->cpu, flags); | |
4492 | ||
4493 | if (!rb) { | |
4494 | ret = -ENOMEM; | |
4495 | goto unlock; | |
4496 | } | |
4497 | ||
4498 | atomic_set(&rb->mmap_count, 1); | |
4499 | rb->mmap_locked = extra; | |
4500 | rb->mmap_user = get_current_user(); | |
4501 | ||
4502 | atomic_long_add(user_extra, &user->locked_vm); | |
4503 | vma->vm_mm->pinned_vm += extra; | |
4504 | ||
4505 | ring_buffer_attach(event, rb); | |
4506 | ||
4507 | perf_event_init_userpage(event); | |
4508 | perf_event_update_userpage(event); | |
4509 | ||
4510 | unlock: | |
4511 | if (!ret) | |
4512 | atomic_inc(&event->mmap_count); | |
4513 | mutex_unlock(&event->mmap_mutex); | |
4514 | ||
4515 | /* | |
4516 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4517 | * vma. | |
4518 | */ | |
4519 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; | |
4520 | vma->vm_ops = &perf_mmap_vmops; | |
4521 | ||
4522 | if (event->pmu->event_mapped) | |
4523 | event->pmu->event_mapped(event); | |
4524 | ||
4525 | return ret; | |
4526 | } | |
4527 | ||
4528 | static int perf_fasync(int fd, struct file *filp, int on) | |
4529 | { | |
4530 | struct inode *inode = file_inode(filp); | |
4531 | struct perf_event *event = filp->private_data; | |
4532 | int retval; | |
4533 | ||
4534 | mutex_lock(&inode->i_mutex); | |
4535 | retval = fasync_helper(fd, filp, on, &event->fasync); | |
4536 | mutex_unlock(&inode->i_mutex); | |
4537 | ||
4538 | if (retval < 0) | |
4539 | return retval; | |
4540 | ||
4541 | return 0; | |
4542 | } | |
4543 | ||
4544 | static const struct file_operations perf_fops = { | |
4545 | .llseek = no_llseek, | |
4546 | .release = perf_release, | |
4547 | .read = perf_read, | |
4548 | .poll = perf_poll, | |
4549 | .unlocked_ioctl = perf_ioctl, | |
4550 | .compat_ioctl = perf_compat_ioctl, | |
4551 | .mmap = perf_mmap, | |
4552 | .fasync = perf_fasync, | |
4553 | }; | |
4554 | ||
4555 | /* | |
4556 | * Perf event wakeup | |
4557 | * | |
4558 | * If there's data, ensure we set the poll() state and publish everything | |
4559 | * to user-space before waking everybody up. | |
4560 | */ | |
4561 | ||
4562 | void perf_event_wakeup(struct perf_event *event) | |
4563 | { | |
4564 | ring_buffer_wakeup(event); | |
4565 | ||
4566 | if (event->pending_kill) { | |
4567 | kill_fasync(&event->fasync, SIGIO, event->pending_kill); | |
4568 | event->pending_kill = 0; | |
4569 | } | |
4570 | } | |
4571 | ||
4572 | static void perf_pending_event(struct irq_work *entry) | |
4573 | { | |
4574 | struct perf_event *event = container_of(entry, | |
4575 | struct perf_event, pending); | |
4576 | ||
4577 | if (event->pending_disable) { | |
4578 | event->pending_disable = 0; | |
4579 | __perf_event_disable(event); | |
4580 | } | |
4581 | ||
4582 | if (event->pending_wakeup) { | |
4583 | event->pending_wakeup = 0; | |
4584 | perf_event_wakeup(event); | |
4585 | } | |
4586 | } | |
4587 | ||
4588 | /* | |
4589 | * We assume there is only KVM supporting the callbacks. | |
4590 | * Later on, we might change it to a list if there is | |
4591 | * another virtualization implementation supporting the callbacks. | |
4592 | */ | |
4593 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4594 | ||
4595 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4596 | { | |
4597 | perf_guest_cbs = cbs; | |
4598 | return 0; | |
4599 | } | |
4600 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4601 | ||
4602 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4603 | { | |
4604 | perf_guest_cbs = NULL; | |
4605 | return 0; | |
4606 | } | |
4607 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4608 | ||
4609 | static void | |
4610 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4611 | struct pt_regs *regs, u64 mask) | |
4612 | { | |
4613 | int bit; | |
4614 | ||
4615 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4616 | sizeof(mask) * BITS_PER_BYTE) { | |
4617 | u64 val; | |
4618 | ||
4619 | val = perf_reg_value(regs, bit); | |
4620 | perf_output_put(handle, val); | |
4621 | } | |
4622 | } | |
4623 | ||
4624 | static void perf_sample_regs_user(struct perf_regs *regs_user, | |
4625 | struct pt_regs *regs, | |
4626 | struct pt_regs *regs_user_copy) | |
4627 | { | |
4628 | if (user_mode(regs)) { | |
4629 | regs_user->abi = perf_reg_abi(current); | |
4630 | regs_user->regs = regs; | |
4631 | } else if (current->mm) { | |
4632 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
4633 | } else { | |
4634 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4635 | regs_user->regs = NULL; | |
4636 | } | |
4637 | } | |
4638 | ||
4639 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, | |
4640 | struct pt_regs *regs) | |
4641 | { | |
4642 | regs_intr->regs = regs; | |
4643 | regs_intr->abi = perf_reg_abi(current); | |
4644 | } | |
4645 | ||
4646 | ||
4647 | /* | |
4648 | * Get remaining task size from user stack pointer. | |
4649 | * | |
4650 | * It'd be better to take stack vma map and limit this more | |
4651 | * precisly, but there's no way to get it safely under interrupt, | |
4652 | * so using TASK_SIZE as limit. | |
4653 | */ | |
4654 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
4655 | { | |
4656 | unsigned long addr = perf_user_stack_pointer(regs); | |
4657 | ||
4658 | if (!addr || addr >= TASK_SIZE) | |
4659 | return 0; | |
4660 | ||
4661 | return TASK_SIZE - addr; | |
4662 | } | |
4663 | ||
4664 | static u16 | |
4665 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
4666 | struct pt_regs *regs) | |
4667 | { | |
4668 | u64 task_size; | |
4669 | ||
4670 | /* No regs, no stack pointer, no dump. */ | |
4671 | if (!regs) | |
4672 | return 0; | |
4673 | ||
4674 | /* | |
4675 | * Check if we fit in with the requested stack size into the: | |
4676 | * - TASK_SIZE | |
4677 | * If we don't, we limit the size to the TASK_SIZE. | |
4678 | * | |
4679 | * - remaining sample size | |
4680 | * If we don't, we customize the stack size to | |
4681 | * fit in to the remaining sample size. | |
4682 | */ | |
4683 | ||
4684 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
4685 | stack_size = min(stack_size, (u16) task_size); | |
4686 | ||
4687 | /* Current header size plus static size and dynamic size. */ | |
4688 | header_size += 2 * sizeof(u64); | |
4689 | ||
4690 | /* Do we fit in with the current stack dump size? */ | |
4691 | if ((u16) (header_size + stack_size) < header_size) { | |
4692 | /* | |
4693 | * If we overflow the maximum size for the sample, | |
4694 | * we customize the stack dump size to fit in. | |
4695 | */ | |
4696 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
4697 | stack_size = round_up(stack_size, sizeof(u64)); | |
4698 | } | |
4699 | ||
4700 | return stack_size; | |
4701 | } | |
4702 | ||
4703 | static void | |
4704 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
4705 | struct pt_regs *regs) | |
4706 | { | |
4707 | /* Case of a kernel thread, nothing to dump */ | |
4708 | if (!regs) { | |
4709 | u64 size = 0; | |
4710 | perf_output_put(handle, size); | |
4711 | } else { | |
4712 | unsigned long sp; | |
4713 | unsigned int rem; | |
4714 | u64 dyn_size; | |
4715 | ||
4716 | /* | |
4717 | * We dump: | |
4718 | * static size | |
4719 | * - the size requested by user or the best one we can fit | |
4720 | * in to the sample max size | |
4721 | * data | |
4722 | * - user stack dump data | |
4723 | * dynamic size | |
4724 | * - the actual dumped size | |
4725 | */ | |
4726 | ||
4727 | /* Static size. */ | |
4728 | perf_output_put(handle, dump_size); | |
4729 | ||
4730 | /* Data. */ | |
4731 | sp = perf_user_stack_pointer(regs); | |
4732 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
4733 | dyn_size = dump_size - rem; | |
4734 | ||
4735 | perf_output_skip(handle, rem); | |
4736 | ||
4737 | /* Dynamic size. */ | |
4738 | perf_output_put(handle, dyn_size); | |
4739 | } | |
4740 | } | |
4741 | ||
4742 | static void __perf_event_header__init_id(struct perf_event_header *header, | |
4743 | struct perf_sample_data *data, | |
4744 | struct perf_event *event) | |
4745 | { | |
4746 | u64 sample_type = event->attr.sample_type; | |
4747 | ||
4748 | data->type = sample_type; | |
4749 | header->size += event->id_header_size; | |
4750 | ||
4751 | if (sample_type & PERF_SAMPLE_TID) { | |
4752 | /* namespace issues */ | |
4753 | data->tid_entry.pid = perf_event_pid(event, current); | |
4754 | data->tid_entry.tid = perf_event_tid(event, current); | |
4755 | } | |
4756 | ||
4757 | if (sample_type & PERF_SAMPLE_TIME) | |
4758 | data->time = perf_clock(); | |
4759 | ||
4760 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) | |
4761 | data->id = primary_event_id(event); | |
4762 | ||
4763 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4764 | data->stream_id = event->id; | |
4765 | ||
4766 | if (sample_type & PERF_SAMPLE_CPU) { | |
4767 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
4768 | data->cpu_entry.reserved = 0; | |
4769 | } | |
4770 | } | |
4771 | ||
4772 | void perf_event_header__init_id(struct perf_event_header *header, | |
4773 | struct perf_sample_data *data, | |
4774 | struct perf_event *event) | |
4775 | { | |
4776 | if (event->attr.sample_id_all) | |
4777 | __perf_event_header__init_id(header, data, event); | |
4778 | } | |
4779 | ||
4780 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
4781 | struct perf_sample_data *data) | |
4782 | { | |
4783 | u64 sample_type = data->type; | |
4784 | ||
4785 | if (sample_type & PERF_SAMPLE_TID) | |
4786 | perf_output_put(handle, data->tid_entry); | |
4787 | ||
4788 | if (sample_type & PERF_SAMPLE_TIME) | |
4789 | perf_output_put(handle, data->time); | |
4790 | ||
4791 | if (sample_type & PERF_SAMPLE_ID) | |
4792 | perf_output_put(handle, data->id); | |
4793 | ||
4794 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4795 | perf_output_put(handle, data->stream_id); | |
4796 | ||
4797 | if (sample_type & PERF_SAMPLE_CPU) | |
4798 | perf_output_put(handle, data->cpu_entry); | |
4799 | ||
4800 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
4801 | perf_output_put(handle, data->id); | |
4802 | } | |
4803 | ||
4804 | void perf_event__output_id_sample(struct perf_event *event, | |
4805 | struct perf_output_handle *handle, | |
4806 | struct perf_sample_data *sample) | |
4807 | { | |
4808 | if (event->attr.sample_id_all) | |
4809 | __perf_event__output_id_sample(handle, sample); | |
4810 | } | |
4811 | ||
4812 | static void perf_output_read_one(struct perf_output_handle *handle, | |
4813 | struct perf_event *event, | |
4814 | u64 enabled, u64 running) | |
4815 | { | |
4816 | u64 read_format = event->attr.read_format; | |
4817 | u64 values[4]; | |
4818 | int n = 0; | |
4819 | ||
4820 | values[n++] = perf_event_count(event); | |
4821 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
4822 | values[n++] = enabled + | |
4823 | atomic64_read(&event->child_total_time_enabled); | |
4824 | } | |
4825 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
4826 | values[n++] = running + | |
4827 | atomic64_read(&event->child_total_time_running); | |
4828 | } | |
4829 | if (read_format & PERF_FORMAT_ID) | |
4830 | values[n++] = primary_event_id(event); | |
4831 | ||
4832 | __output_copy(handle, values, n * sizeof(u64)); | |
4833 | } | |
4834 | ||
4835 | /* | |
4836 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. | |
4837 | */ | |
4838 | static void perf_output_read_group(struct perf_output_handle *handle, | |
4839 | struct perf_event *event, | |
4840 | u64 enabled, u64 running) | |
4841 | { | |
4842 | struct perf_event *leader = event->group_leader, *sub; | |
4843 | u64 read_format = event->attr.read_format; | |
4844 | u64 values[5]; | |
4845 | int n = 0; | |
4846 | ||
4847 | values[n++] = 1 + leader->nr_siblings; | |
4848 | ||
4849 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4850 | values[n++] = enabled; | |
4851 | ||
4852 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4853 | values[n++] = running; | |
4854 | ||
4855 | if (leader != event) | |
4856 | leader->pmu->read(leader); | |
4857 | ||
4858 | values[n++] = perf_event_count(leader); | |
4859 | if (read_format & PERF_FORMAT_ID) | |
4860 | values[n++] = primary_event_id(leader); | |
4861 | ||
4862 | __output_copy(handle, values, n * sizeof(u64)); | |
4863 | ||
4864 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { | |
4865 | n = 0; | |
4866 | ||
4867 | if ((sub != event) && | |
4868 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
4869 | sub->pmu->read(sub); | |
4870 | ||
4871 | values[n++] = perf_event_count(sub); | |
4872 | if (read_format & PERF_FORMAT_ID) | |
4873 | values[n++] = primary_event_id(sub); | |
4874 | ||
4875 | __output_copy(handle, values, n * sizeof(u64)); | |
4876 | } | |
4877 | } | |
4878 | ||
4879 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ | |
4880 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4881 | ||
4882 | static void perf_output_read(struct perf_output_handle *handle, | |
4883 | struct perf_event *event) | |
4884 | { | |
4885 | u64 enabled = 0, running = 0, now; | |
4886 | u64 read_format = event->attr.read_format; | |
4887 | ||
4888 | /* | |
4889 | * compute total_time_enabled, total_time_running | |
4890 | * based on snapshot values taken when the event | |
4891 | * was last scheduled in. | |
4892 | * | |
4893 | * we cannot simply called update_context_time() | |
4894 | * because of locking issue as we are called in | |
4895 | * NMI context | |
4896 | */ | |
4897 | if (read_format & PERF_FORMAT_TOTAL_TIMES) | |
4898 | calc_timer_values(event, &now, &enabled, &running); | |
4899 | ||
4900 | if (event->attr.read_format & PERF_FORMAT_GROUP) | |
4901 | perf_output_read_group(handle, event, enabled, running); | |
4902 | else | |
4903 | perf_output_read_one(handle, event, enabled, running); | |
4904 | } | |
4905 | ||
4906 | void perf_output_sample(struct perf_output_handle *handle, | |
4907 | struct perf_event_header *header, | |
4908 | struct perf_sample_data *data, | |
4909 | struct perf_event *event) | |
4910 | { | |
4911 | u64 sample_type = data->type; | |
4912 | ||
4913 | perf_output_put(handle, *header); | |
4914 | ||
4915 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
4916 | perf_output_put(handle, data->id); | |
4917 | ||
4918 | if (sample_type & PERF_SAMPLE_IP) | |
4919 | perf_output_put(handle, data->ip); | |
4920 | ||
4921 | if (sample_type & PERF_SAMPLE_TID) | |
4922 | perf_output_put(handle, data->tid_entry); | |
4923 | ||
4924 | if (sample_type & PERF_SAMPLE_TIME) | |
4925 | perf_output_put(handle, data->time); | |
4926 | ||
4927 | if (sample_type & PERF_SAMPLE_ADDR) | |
4928 | perf_output_put(handle, data->addr); | |
4929 | ||
4930 | if (sample_type & PERF_SAMPLE_ID) | |
4931 | perf_output_put(handle, data->id); | |
4932 | ||
4933 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4934 | perf_output_put(handle, data->stream_id); | |
4935 | ||
4936 | if (sample_type & PERF_SAMPLE_CPU) | |
4937 | perf_output_put(handle, data->cpu_entry); | |
4938 | ||
4939 | if (sample_type & PERF_SAMPLE_PERIOD) | |
4940 | perf_output_put(handle, data->period); | |
4941 | ||
4942 | if (sample_type & PERF_SAMPLE_READ) | |
4943 | perf_output_read(handle, event); | |
4944 | ||
4945 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
4946 | if (data->callchain) { | |
4947 | int size = 1; | |
4948 | ||
4949 | if (data->callchain) | |
4950 | size += data->callchain->nr; | |
4951 | ||
4952 | size *= sizeof(u64); | |
4953 | ||
4954 | __output_copy(handle, data->callchain, size); | |
4955 | } else { | |
4956 | u64 nr = 0; | |
4957 | perf_output_put(handle, nr); | |
4958 | } | |
4959 | } | |
4960 | ||
4961 | if (sample_type & PERF_SAMPLE_RAW) { | |
4962 | if (data->raw) { | |
4963 | perf_output_put(handle, data->raw->size); | |
4964 | __output_copy(handle, data->raw->data, | |
4965 | data->raw->size); | |
4966 | } else { | |
4967 | struct { | |
4968 | u32 size; | |
4969 | u32 data; | |
4970 | } raw = { | |
4971 | .size = sizeof(u32), | |
4972 | .data = 0, | |
4973 | }; | |
4974 | perf_output_put(handle, raw); | |
4975 | } | |
4976 | } | |
4977 | ||
4978 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
4979 | if (data->br_stack) { | |
4980 | size_t size; | |
4981 | ||
4982 | size = data->br_stack->nr | |
4983 | * sizeof(struct perf_branch_entry); | |
4984 | ||
4985 | perf_output_put(handle, data->br_stack->nr); | |
4986 | perf_output_copy(handle, data->br_stack->entries, size); | |
4987 | } else { | |
4988 | /* | |
4989 | * we always store at least the value of nr | |
4990 | */ | |
4991 | u64 nr = 0; | |
4992 | perf_output_put(handle, nr); | |
4993 | } | |
4994 | } | |
4995 | ||
4996 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
4997 | u64 abi = data->regs_user.abi; | |
4998 | ||
4999 | /* | |
5000 | * If there are no regs to dump, notice it through | |
5001 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5002 | */ | |
5003 | perf_output_put(handle, abi); | |
5004 | ||
5005 | if (abi) { | |
5006 | u64 mask = event->attr.sample_regs_user; | |
5007 | perf_output_sample_regs(handle, | |
5008 | data->regs_user.regs, | |
5009 | mask); | |
5010 | } | |
5011 | } | |
5012 | ||
5013 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5014 | perf_output_sample_ustack(handle, | |
5015 | data->stack_user_size, | |
5016 | data->regs_user.regs); | |
5017 | } | |
5018 | ||
5019 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5020 | perf_output_put(handle, data->weight); | |
5021 | ||
5022 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5023 | perf_output_put(handle, data->data_src.val); | |
5024 | ||
5025 | if (sample_type & PERF_SAMPLE_TRANSACTION) | |
5026 | perf_output_put(handle, data->txn); | |
5027 | ||
5028 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5029 | u64 abi = data->regs_intr.abi; | |
5030 | /* | |
5031 | * If there are no regs to dump, notice it through | |
5032 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5033 | */ | |
5034 | perf_output_put(handle, abi); | |
5035 | ||
5036 | if (abi) { | |
5037 | u64 mask = event->attr.sample_regs_intr; | |
5038 | ||
5039 | perf_output_sample_regs(handle, | |
5040 | data->regs_intr.regs, | |
5041 | mask); | |
5042 | } | |
5043 | } | |
5044 | ||
5045 | if (!event->attr.watermark) { | |
5046 | int wakeup_events = event->attr.wakeup_events; | |
5047 | ||
5048 | if (wakeup_events) { | |
5049 | struct ring_buffer *rb = handle->rb; | |
5050 | int events = local_inc_return(&rb->events); | |
5051 | ||
5052 | if (events >= wakeup_events) { | |
5053 | local_sub(wakeup_events, &rb->events); | |
5054 | local_inc(&rb->wakeup); | |
5055 | } | |
5056 | } | |
5057 | } | |
5058 | } | |
5059 | ||
5060 | void perf_prepare_sample(struct perf_event_header *header, | |
5061 | struct perf_sample_data *data, | |
5062 | struct perf_event *event, | |
5063 | struct pt_regs *regs) | |
5064 | { | |
5065 | u64 sample_type = event->attr.sample_type; | |
5066 | ||
5067 | header->type = PERF_RECORD_SAMPLE; | |
5068 | header->size = sizeof(*header) + event->header_size; | |
5069 | ||
5070 | header->misc = 0; | |
5071 | header->misc |= perf_misc_flags(regs); | |
5072 | ||
5073 | __perf_event_header__init_id(header, data, event); | |
5074 | ||
5075 | if (sample_type & PERF_SAMPLE_IP) | |
5076 | data->ip = perf_instruction_pointer(regs); | |
5077 | ||
5078 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5079 | int size = 1; | |
5080 | ||
5081 | data->callchain = perf_callchain(event, regs); | |
5082 | ||
5083 | if (data->callchain) | |
5084 | size += data->callchain->nr; | |
5085 | ||
5086 | header->size += size * sizeof(u64); | |
5087 | } | |
5088 | ||
5089 | if (sample_type & PERF_SAMPLE_RAW) { | |
5090 | int size = sizeof(u32); | |
5091 | ||
5092 | if (data->raw) | |
5093 | size += data->raw->size; | |
5094 | else | |
5095 | size += sizeof(u32); | |
5096 | ||
5097 | WARN_ON_ONCE(size & (sizeof(u64)-1)); | |
5098 | header->size += size; | |
5099 | } | |
5100 | ||
5101 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5102 | int size = sizeof(u64); /* nr */ | |
5103 | if (data->br_stack) { | |
5104 | size += data->br_stack->nr | |
5105 | * sizeof(struct perf_branch_entry); | |
5106 | } | |
5107 | header->size += size; | |
5108 | } | |
5109 | ||
5110 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) | |
5111 | perf_sample_regs_user(&data->regs_user, regs, | |
5112 | &data->regs_user_copy); | |
5113 | ||
5114 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5115 | /* regs dump ABI info */ | |
5116 | int size = sizeof(u64); | |
5117 | ||
5118 | if (data->regs_user.regs) { | |
5119 | u64 mask = event->attr.sample_regs_user; | |
5120 | size += hweight64(mask) * sizeof(u64); | |
5121 | } | |
5122 | ||
5123 | header->size += size; | |
5124 | } | |
5125 | ||
5126 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5127 | /* | |
5128 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5129 | * processed as the last one or have additional check added | |
5130 | * in case new sample type is added, because we could eat | |
5131 | * up the rest of the sample size. | |
5132 | */ | |
5133 | u16 stack_size = event->attr.sample_stack_user; | |
5134 | u16 size = sizeof(u64); | |
5135 | ||
5136 | stack_size = perf_sample_ustack_size(stack_size, header->size, | |
5137 | data->regs_user.regs); | |
5138 | ||
5139 | /* | |
5140 | * If there is something to dump, add space for the dump | |
5141 | * itself and for the field that tells the dynamic size, | |
5142 | * which is how many have been actually dumped. | |
5143 | */ | |
5144 | if (stack_size) | |
5145 | size += sizeof(u64) + stack_size; | |
5146 | ||
5147 | data->stack_user_size = stack_size; | |
5148 | header->size += size; | |
5149 | } | |
5150 | ||
5151 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5152 | /* regs dump ABI info */ | |
5153 | int size = sizeof(u64); | |
5154 | ||
5155 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5156 | ||
5157 | if (data->regs_intr.regs) { | |
5158 | u64 mask = event->attr.sample_regs_intr; | |
5159 | ||
5160 | size += hweight64(mask) * sizeof(u64); | |
5161 | } | |
5162 | ||
5163 | header->size += size; | |
5164 | } | |
5165 | } | |
5166 | ||
5167 | static void perf_event_output(struct perf_event *event, | |
5168 | struct perf_sample_data *data, | |
5169 | struct pt_regs *regs) | |
5170 | { | |
5171 | struct perf_output_handle handle; | |
5172 | struct perf_event_header header; | |
5173 | ||
5174 | /* protect the callchain buffers */ | |
5175 | rcu_read_lock(); | |
5176 | ||
5177 | perf_prepare_sample(&header, data, event, regs); | |
5178 | ||
5179 | if (perf_output_begin(&handle, event, header.size)) | |
5180 | goto exit; | |
5181 | ||
5182 | perf_output_sample(&handle, &header, data, event); | |
5183 | ||
5184 | perf_output_end(&handle); | |
5185 | ||
5186 | exit: | |
5187 | rcu_read_unlock(); | |
5188 | } | |
5189 | ||
5190 | /* | |
5191 | * read event_id | |
5192 | */ | |
5193 | ||
5194 | struct perf_read_event { | |
5195 | struct perf_event_header header; | |
5196 | ||
5197 | u32 pid; | |
5198 | u32 tid; | |
5199 | }; | |
5200 | ||
5201 | static void | |
5202 | perf_event_read_event(struct perf_event *event, | |
5203 | struct task_struct *task) | |
5204 | { | |
5205 | struct perf_output_handle handle; | |
5206 | struct perf_sample_data sample; | |
5207 | struct perf_read_event read_event = { | |
5208 | .header = { | |
5209 | .type = PERF_RECORD_READ, | |
5210 | .misc = 0, | |
5211 | .size = sizeof(read_event) + event->read_size, | |
5212 | }, | |
5213 | .pid = perf_event_pid(event, task), | |
5214 | .tid = perf_event_tid(event, task), | |
5215 | }; | |
5216 | int ret; | |
5217 | ||
5218 | perf_event_header__init_id(&read_event.header, &sample, event); | |
5219 | ret = perf_output_begin(&handle, event, read_event.header.size); | |
5220 | if (ret) | |
5221 | return; | |
5222 | ||
5223 | perf_output_put(&handle, read_event); | |
5224 | perf_output_read(&handle, event); | |
5225 | perf_event__output_id_sample(event, &handle, &sample); | |
5226 | ||
5227 | perf_output_end(&handle); | |
5228 | } | |
5229 | ||
5230 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); | |
5231 | ||
5232 | static void | |
5233 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
5234 | perf_event_aux_output_cb output, | |
5235 | void *data) | |
5236 | { | |
5237 | struct perf_event *event; | |
5238 | ||
5239 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5240 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5241 | continue; | |
5242 | if (!event_filter_match(event)) | |
5243 | continue; | |
5244 | output(event, data); | |
5245 | } | |
5246 | } | |
5247 | ||
5248 | static void | |
5249 | perf_event_aux(perf_event_aux_output_cb output, void *data, | |
5250 | struct perf_event_context *task_ctx) | |
5251 | { | |
5252 | struct perf_cpu_context *cpuctx; | |
5253 | struct perf_event_context *ctx; | |
5254 | struct pmu *pmu; | |
5255 | int ctxn; | |
5256 | ||
5257 | rcu_read_lock(); | |
5258 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5259 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5260 | if (cpuctx->unique_pmu != pmu) | |
5261 | goto next; | |
5262 | perf_event_aux_ctx(&cpuctx->ctx, output, data); | |
5263 | if (task_ctx) | |
5264 | goto next; | |
5265 | ctxn = pmu->task_ctx_nr; | |
5266 | if (ctxn < 0) | |
5267 | goto next; | |
5268 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5269 | if (ctx) | |
5270 | perf_event_aux_ctx(ctx, output, data); | |
5271 | next: | |
5272 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5273 | } | |
5274 | ||
5275 | if (task_ctx) { | |
5276 | preempt_disable(); | |
5277 | perf_event_aux_ctx(task_ctx, output, data); | |
5278 | preempt_enable(); | |
5279 | } | |
5280 | rcu_read_unlock(); | |
5281 | } | |
5282 | ||
5283 | /* | |
5284 | * task tracking -- fork/exit | |
5285 | * | |
5286 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task | |
5287 | */ | |
5288 | ||
5289 | struct perf_task_event { | |
5290 | struct task_struct *task; | |
5291 | struct perf_event_context *task_ctx; | |
5292 | ||
5293 | struct { | |
5294 | struct perf_event_header header; | |
5295 | ||
5296 | u32 pid; | |
5297 | u32 ppid; | |
5298 | u32 tid; | |
5299 | u32 ptid; | |
5300 | u64 time; | |
5301 | } event_id; | |
5302 | }; | |
5303 | ||
5304 | static int perf_event_task_match(struct perf_event *event) | |
5305 | { | |
5306 | return event->attr.comm || event->attr.mmap || | |
5307 | event->attr.mmap2 || event->attr.mmap_data || | |
5308 | event->attr.task; | |
5309 | } | |
5310 | ||
5311 | static void perf_event_task_output(struct perf_event *event, | |
5312 | void *data) | |
5313 | { | |
5314 | struct perf_task_event *task_event = data; | |
5315 | struct perf_output_handle handle; | |
5316 | struct perf_sample_data sample; | |
5317 | struct task_struct *task = task_event->task; | |
5318 | int ret, size = task_event->event_id.header.size; | |
5319 | ||
5320 | if (!perf_event_task_match(event)) | |
5321 | return; | |
5322 | ||
5323 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); | |
5324 | ||
5325 | ret = perf_output_begin(&handle, event, | |
5326 | task_event->event_id.header.size); | |
5327 | if (ret) | |
5328 | goto out; | |
5329 | ||
5330 | task_event->event_id.pid = perf_event_pid(event, task); | |
5331 | task_event->event_id.ppid = perf_event_pid(event, current); | |
5332 | ||
5333 | task_event->event_id.tid = perf_event_tid(event, task); | |
5334 | task_event->event_id.ptid = perf_event_tid(event, current); | |
5335 | ||
5336 | perf_output_put(&handle, task_event->event_id); | |
5337 | ||
5338 | perf_event__output_id_sample(event, &handle, &sample); | |
5339 | ||
5340 | perf_output_end(&handle); | |
5341 | out: | |
5342 | task_event->event_id.header.size = size; | |
5343 | } | |
5344 | ||
5345 | static void perf_event_task(struct task_struct *task, | |
5346 | struct perf_event_context *task_ctx, | |
5347 | int new) | |
5348 | { | |
5349 | struct perf_task_event task_event; | |
5350 | ||
5351 | if (!atomic_read(&nr_comm_events) && | |
5352 | !atomic_read(&nr_mmap_events) && | |
5353 | !atomic_read(&nr_task_events)) | |
5354 | return; | |
5355 | ||
5356 | task_event = (struct perf_task_event){ | |
5357 | .task = task, | |
5358 | .task_ctx = task_ctx, | |
5359 | .event_id = { | |
5360 | .header = { | |
5361 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, | |
5362 | .misc = 0, | |
5363 | .size = sizeof(task_event.event_id), | |
5364 | }, | |
5365 | /* .pid */ | |
5366 | /* .ppid */ | |
5367 | /* .tid */ | |
5368 | /* .ptid */ | |
5369 | .time = perf_clock(), | |
5370 | }, | |
5371 | }; | |
5372 | ||
5373 | perf_event_aux(perf_event_task_output, | |
5374 | &task_event, | |
5375 | task_ctx); | |
5376 | } | |
5377 | ||
5378 | void perf_event_fork(struct task_struct *task) | |
5379 | { | |
5380 | perf_event_task(task, NULL, 1); | |
5381 | } | |
5382 | ||
5383 | /* | |
5384 | * comm tracking | |
5385 | */ | |
5386 | ||
5387 | struct perf_comm_event { | |
5388 | struct task_struct *task; | |
5389 | char *comm; | |
5390 | int comm_size; | |
5391 | ||
5392 | struct { | |
5393 | struct perf_event_header header; | |
5394 | ||
5395 | u32 pid; | |
5396 | u32 tid; | |
5397 | } event_id; | |
5398 | }; | |
5399 | ||
5400 | static int perf_event_comm_match(struct perf_event *event) | |
5401 | { | |
5402 | return event->attr.comm; | |
5403 | } | |
5404 | ||
5405 | static void perf_event_comm_output(struct perf_event *event, | |
5406 | void *data) | |
5407 | { | |
5408 | struct perf_comm_event *comm_event = data; | |
5409 | struct perf_output_handle handle; | |
5410 | struct perf_sample_data sample; | |
5411 | int size = comm_event->event_id.header.size; | |
5412 | int ret; | |
5413 | ||
5414 | if (!perf_event_comm_match(event)) | |
5415 | return; | |
5416 | ||
5417 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); | |
5418 | ret = perf_output_begin(&handle, event, | |
5419 | comm_event->event_id.header.size); | |
5420 | ||
5421 | if (ret) | |
5422 | goto out; | |
5423 | ||
5424 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); | |
5425 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
5426 | ||
5427 | perf_output_put(&handle, comm_event->event_id); | |
5428 | __output_copy(&handle, comm_event->comm, | |
5429 | comm_event->comm_size); | |
5430 | ||
5431 | perf_event__output_id_sample(event, &handle, &sample); | |
5432 | ||
5433 | perf_output_end(&handle); | |
5434 | out: | |
5435 | comm_event->event_id.header.size = size; | |
5436 | } | |
5437 | ||
5438 | static void perf_event_comm_event(struct perf_comm_event *comm_event) | |
5439 | { | |
5440 | char comm[TASK_COMM_LEN]; | |
5441 | unsigned int size; | |
5442 | ||
5443 | memset(comm, 0, sizeof(comm)); | |
5444 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); | |
5445 | size = ALIGN(strlen(comm)+1, sizeof(u64)); | |
5446 | ||
5447 | comm_event->comm = comm; | |
5448 | comm_event->comm_size = size; | |
5449 | ||
5450 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; | |
5451 | ||
5452 | perf_event_aux(perf_event_comm_output, | |
5453 | comm_event, | |
5454 | NULL); | |
5455 | } | |
5456 | ||
5457 | void perf_event_comm(struct task_struct *task, bool exec) | |
5458 | { | |
5459 | struct perf_comm_event comm_event; | |
5460 | ||
5461 | if (!atomic_read(&nr_comm_events)) | |
5462 | return; | |
5463 | ||
5464 | comm_event = (struct perf_comm_event){ | |
5465 | .task = task, | |
5466 | /* .comm */ | |
5467 | /* .comm_size */ | |
5468 | .event_id = { | |
5469 | .header = { | |
5470 | .type = PERF_RECORD_COMM, | |
5471 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, | |
5472 | /* .size */ | |
5473 | }, | |
5474 | /* .pid */ | |
5475 | /* .tid */ | |
5476 | }, | |
5477 | }; | |
5478 | ||
5479 | perf_event_comm_event(&comm_event); | |
5480 | } | |
5481 | ||
5482 | /* | |
5483 | * mmap tracking | |
5484 | */ | |
5485 | ||
5486 | struct perf_mmap_event { | |
5487 | struct vm_area_struct *vma; | |
5488 | ||
5489 | const char *file_name; | |
5490 | int file_size; | |
5491 | int maj, min; | |
5492 | u64 ino; | |
5493 | u64 ino_generation; | |
5494 | u32 prot, flags; | |
5495 | ||
5496 | struct { | |
5497 | struct perf_event_header header; | |
5498 | ||
5499 | u32 pid; | |
5500 | u32 tid; | |
5501 | u64 start; | |
5502 | u64 len; | |
5503 | u64 pgoff; | |
5504 | } event_id; | |
5505 | }; | |
5506 | ||
5507 | static int perf_event_mmap_match(struct perf_event *event, | |
5508 | void *data) | |
5509 | { | |
5510 | struct perf_mmap_event *mmap_event = data; | |
5511 | struct vm_area_struct *vma = mmap_event->vma; | |
5512 | int executable = vma->vm_flags & VM_EXEC; | |
5513 | ||
5514 | return (!executable && event->attr.mmap_data) || | |
5515 | (executable && (event->attr.mmap || event->attr.mmap2)); | |
5516 | } | |
5517 | ||
5518 | static void perf_event_mmap_output(struct perf_event *event, | |
5519 | void *data) | |
5520 | { | |
5521 | struct perf_mmap_event *mmap_event = data; | |
5522 | struct perf_output_handle handle; | |
5523 | struct perf_sample_data sample; | |
5524 | int size = mmap_event->event_id.header.size; | |
5525 | int ret; | |
5526 | ||
5527 | if (!perf_event_mmap_match(event, data)) | |
5528 | return; | |
5529 | ||
5530 | if (event->attr.mmap2) { | |
5531 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5532 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5533 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5534 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
5535 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); | |
5536 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); | |
5537 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
5538 | } | |
5539 | ||
5540 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); | |
5541 | ret = perf_output_begin(&handle, event, | |
5542 | mmap_event->event_id.header.size); | |
5543 | if (ret) | |
5544 | goto out; | |
5545 | ||
5546 | mmap_event->event_id.pid = perf_event_pid(event, current); | |
5547 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
5548 | ||
5549 | perf_output_put(&handle, mmap_event->event_id); | |
5550 | ||
5551 | if (event->attr.mmap2) { | |
5552 | perf_output_put(&handle, mmap_event->maj); | |
5553 | perf_output_put(&handle, mmap_event->min); | |
5554 | perf_output_put(&handle, mmap_event->ino); | |
5555 | perf_output_put(&handle, mmap_event->ino_generation); | |
5556 | perf_output_put(&handle, mmap_event->prot); | |
5557 | perf_output_put(&handle, mmap_event->flags); | |
5558 | } | |
5559 | ||
5560 | __output_copy(&handle, mmap_event->file_name, | |
5561 | mmap_event->file_size); | |
5562 | ||
5563 | perf_event__output_id_sample(event, &handle, &sample); | |
5564 | ||
5565 | perf_output_end(&handle); | |
5566 | out: | |
5567 | mmap_event->event_id.header.size = size; | |
5568 | } | |
5569 | ||
5570 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) | |
5571 | { | |
5572 | struct vm_area_struct *vma = mmap_event->vma; | |
5573 | struct file *file = vma->vm_file; | |
5574 | int maj = 0, min = 0; | |
5575 | u64 ino = 0, gen = 0; | |
5576 | u32 prot = 0, flags = 0; | |
5577 | unsigned int size; | |
5578 | char tmp[16]; | |
5579 | char *buf = NULL; | |
5580 | char *name; | |
5581 | ||
5582 | if (file) { | |
5583 | struct inode *inode; | |
5584 | dev_t dev; | |
5585 | ||
5586 | buf = kmalloc(PATH_MAX, GFP_KERNEL); | |
5587 | if (!buf) { | |
5588 | name = "//enomem"; | |
5589 | goto cpy_name; | |
5590 | } | |
5591 | /* | |
5592 | * d_path() works from the end of the rb backwards, so we | |
5593 | * need to add enough zero bytes after the string to handle | |
5594 | * the 64bit alignment we do later. | |
5595 | */ | |
5596 | name = d_path(&file->f_path, buf, PATH_MAX - sizeof(u64)); | |
5597 | if (IS_ERR(name)) { | |
5598 | name = "//toolong"; | |
5599 | goto cpy_name; | |
5600 | } | |
5601 | inode = file_inode(vma->vm_file); | |
5602 | dev = inode->i_sb->s_dev; | |
5603 | ino = inode->i_ino; | |
5604 | gen = inode->i_generation; | |
5605 | maj = MAJOR(dev); | |
5606 | min = MINOR(dev); | |
5607 | ||
5608 | if (vma->vm_flags & VM_READ) | |
5609 | prot |= PROT_READ; | |
5610 | if (vma->vm_flags & VM_WRITE) | |
5611 | prot |= PROT_WRITE; | |
5612 | if (vma->vm_flags & VM_EXEC) | |
5613 | prot |= PROT_EXEC; | |
5614 | ||
5615 | if (vma->vm_flags & VM_MAYSHARE) | |
5616 | flags = MAP_SHARED; | |
5617 | else | |
5618 | flags = MAP_PRIVATE; | |
5619 | ||
5620 | if (vma->vm_flags & VM_DENYWRITE) | |
5621 | flags |= MAP_DENYWRITE; | |
5622 | if (vma->vm_flags & VM_MAYEXEC) | |
5623 | flags |= MAP_EXECUTABLE; | |
5624 | if (vma->vm_flags & VM_LOCKED) | |
5625 | flags |= MAP_LOCKED; | |
5626 | if (vma->vm_flags & VM_HUGETLB) | |
5627 | flags |= MAP_HUGETLB; | |
5628 | ||
5629 | goto got_name; | |
5630 | } else { | |
5631 | if (vma->vm_ops && vma->vm_ops->name) { | |
5632 | name = (char *) vma->vm_ops->name(vma); | |
5633 | if (name) | |
5634 | goto cpy_name; | |
5635 | } | |
5636 | ||
5637 | name = (char *)arch_vma_name(vma); | |
5638 | if (name) | |
5639 | goto cpy_name; | |
5640 | ||
5641 | if (vma->vm_start <= vma->vm_mm->start_brk && | |
5642 | vma->vm_end >= vma->vm_mm->brk) { | |
5643 | name = "[heap]"; | |
5644 | goto cpy_name; | |
5645 | } | |
5646 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
5647 | vma->vm_end >= vma->vm_mm->start_stack) { | |
5648 | name = "[stack]"; | |
5649 | goto cpy_name; | |
5650 | } | |
5651 | ||
5652 | name = "//anon"; | |
5653 | goto cpy_name; | |
5654 | } | |
5655 | ||
5656 | cpy_name: | |
5657 | strlcpy(tmp, name, sizeof(tmp)); | |
5658 | name = tmp; | |
5659 | got_name: | |
5660 | /* | |
5661 | * Since our buffer works in 8 byte units we need to align our string | |
5662 | * size to a multiple of 8. However, we must guarantee the tail end is | |
5663 | * zero'd out to avoid leaking random bits to userspace. | |
5664 | */ | |
5665 | size = strlen(name)+1; | |
5666 | while (!IS_ALIGNED(size, sizeof(u64))) | |
5667 | name[size++] = '\0'; | |
5668 | ||
5669 | mmap_event->file_name = name; | |
5670 | mmap_event->file_size = size; | |
5671 | mmap_event->maj = maj; | |
5672 | mmap_event->min = min; | |
5673 | mmap_event->ino = ino; | |
5674 | mmap_event->ino_generation = gen; | |
5675 | mmap_event->prot = prot; | |
5676 | mmap_event->flags = flags; | |
5677 | ||
5678 | if (!(vma->vm_flags & VM_EXEC)) | |
5679 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
5680 | ||
5681 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; | |
5682 | ||
5683 | perf_event_aux(perf_event_mmap_output, | |
5684 | mmap_event, | |
5685 | NULL); | |
5686 | ||
5687 | kfree(buf); | |
5688 | } | |
5689 | ||
5690 | void perf_event_mmap(struct vm_area_struct *vma) | |
5691 | { | |
5692 | struct perf_mmap_event mmap_event; | |
5693 | ||
5694 | if (!atomic_read(&nr_mmap_events)) | |
5695 | return; | |
5696 | ||
5697 | mmap_event = (struct perf_mmap_event){ | |
5698 | .vma = vma, | |
5699 | /* .file_name */ | |
5700 | /* .file_size */ | |
5701 | .event_id = { | |
5702 | .header = { | |
5703 | .type = PERF_RECORD_MMAP, | |
5704 | .misc = PERF_RECORD_MISC_USER, | |
5705 | /* .size */ | |
5706 | }, | |
5707 | /* .pid */ | |
5708 | /* .tid */ | |
5709 | .start = vma->vm_start, | |
5710 | .len = vma->vm_end - vma->vm_start, | |
5711 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, | |
5712 | }, | |
5713 | /* .maj (attr_mmap2 only) */ | |
5714 | /* .min (attr_mmap2 only) */ | |
5715 | /* .ino (attr_mmap2 only) */ | |
5716 | /* .ino_generation (attr_mmap2 only) */ | |
5717 | /* .prot (attr_mmap2 only) */ | |
5718 | /* .flags (attr_mmap2 only) */ | |
5719 | }; | |
5720 | ||
5721 | perf_event_mmap_event(&mmap_event); | |
5722 | } | |
5723 | ||
5724 | /* | |
5725 | * IRQ throttle logging | |
5726 | */ | |
5727 | ||
5728 | static void perf_log_throttle(struct perf_event *event, int enable) | |
5729 | { | |
5730 | struct perf_output_handle handle; | |
5731 | struct perf_sample_data sample; | |
5732 | int ret; | |
5733 | ||
5734 | struct { | |
5735 | struct perf_event_header header; | |
5736 | u64 time; | |
5737 | u64 id; | |
5738 | u64 stream_id; | |
5739 | } throttle_event = { | |
5740 | .header = { | |
5741 | .type = PERF_RECORD_THROTTLE, | |
5742 | .misc = 0, | |
5743 | .size = sizeof(throttle_event), | |
5744 | }, | |
5745 | .time = perf_clock(), | |
5746 | .id = primary_event_id(event), | |
5747 | .stream_id = event->id, | |
5748 | }; | |
5749 | ||
5750 | if (enable) | |
5751 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; | |
5752 | ||
5753 | perf_event_header__init_id(&throttle_event.header, &sample, event); | |
5754 | ||
5755 | ret = perf_output_begin(&handle, event, | |
5756 | throttle_event.header.size); | |
5757 | if (ret) | |
5758 | return; | |
5759 | ||
5760 | perf_output_put(&handle, throttle_event); | |
5761 | perf_event__output_id_sample(event, &handle, &sample); | |
5762 | perf_output_end(&handle); | |
5763 | } | |
5764 | ||
5765 | /* | |
5766 | * Generic event overflow handling, sampling. | |
5767 | */ | |
5768 | ||
5769 | static int __perf_event_overflow(struct perf_event *event, | |
5770 | int throttle, struct perf_sample_data *data, | |
5771 | struct pt_regs *regs) | |
5772 | { | |
5773 | int events = atomic_read(&event->event_limit); | |
5774 | struct hw_perf_event *hwc = &event->hw; | |
5775 | u64 seq; | |
5776 | int ret = 0; | |
5777 | ||
5778 | /* | |
5779 | * Non-sampling counters might still use the PMI to fold short | |
5780 | * hardware counters, ignore those. | |
5781 | */ | |
5782 | if (unlikely(!is_sampling_event(event))) | |
5783 | return 0; | |
5784 | ||
5785 | seq = __this_cpu_read(perf_throttled_seq); | |
5786 | if (seq != hwc->interrupts_seq) { | |
5787 | hwc->interrupts_seq = seq; | |
5788 | hwc->interrupts = 1; | |
5789 | } else { | |
5790 | hwc->interrupts++; | |
5791 | if (unlikely(throttle | |
5792 | && hwc->interrupts >= max_samples_per_tick)) { | |
5793 | __this_cpu_inc(perf_throttled_count); | |
5794 | hwc->interrupts = MAX_INTERRUPTS; | |
5795 | perf_log_throttle(event, 0); | |
5796 | tick_nohz_full_kick(); | |
5797 | ret = 1; | |
5798 | } | |
5799 | } | |
5800 | ||
5801 | if (event->attr.freq) { | |
5802 | u64 now = perf_clock(); | |
5803 | s64 delta = now - hwc->freq_time_stamp; | |
5804 | ||
5805 | hwc->freq_time_stamp = now; | |
5806 | ||
5807 | if (delta > 0 && delta < 2*TICK_NSEC) | |
5808 | perf_adjust_period(event, delta, hwc->last_period, true); | |
5809 | } | |
5810 | ||
5811 | /* | |
5812 | * XXX event_limit might not quite work as expected on inherited | |
5813 | * events | |
5814 | */ | |
5815 | ||
5816 | event->pending_kill = POLL_IN; | |
5817 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
5818 | ret = 1; | |
5819 | event->pending_kill = POLL_HUP; | |
5820 | event->pending_disable = 1; | |
5821 | irq_work_queue(&event->pending); | |
5822 | } | |
5823 | ||
5824 | if (event->overflow_handler) | |
5825 | event->overflow_handler(event, data, regs); | |
5826 | else | |
5827 | perf_event_output(event, data, regs); | |
5828 | ||
5829 | if (event->fasync && event->pending_kill) { | |
5830 | event->pending_wakeup = 1; | |
5831 | irq_work_queue(&event->pending); | |
5832 | } | |
5833 | ||
5834 | return ret; | |
5835 | } | |
5836 | ||
5837 | int perf_event_overflow(struct perf_event *event, | |
5838 | struct perf_sample_data *data, | |
5839 | struct pt_regs *regs) | |
5840 | { | |
5841 | return __perf_event_overflow(event, 1, data, regs); | |
5842 | } | |
5843 | ||
5844 | /* | |
5845 | * Generic software event infrastructure | |
5846 | */ | |
5847 | ||
5848 | struct swevent_htable { | |
5849 | struct swevent_hlist *swevent_hlist; | |
5850 | struct mutex hlist_mutex; | |
5851 | int hlist_refcount; | |
5852 | ||
5853 | /* Recursion avoidance in each contexts */ | |
5854 | int recursion[PERF_NR_CONTEXTS]; | |
5855 | ||
5856 | /* Keeps track of cpu being initialized/exited */ | |
5857 | bool online; | |
5858 | }; | |
5859 | ||
5860 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
5861 | ||
5862 | /* | |
5863 | * We directly increment event->count and keep a second value in | |
5864 | * event->hw.period_left to count intervals. This period event | |
5865 | * is kept in the range [-sample_period, 0] so that we can use the | |
5866 | * sign as trigger. | |
5867 | */ | |
5868 | ||
5869 | u64 perf_swevent_set_period(struct perf_event *event) | |
5870 | { | |
5871 | struct hw_perf_event *hwc = &event->hw; | |
5872 | u64 period = hwc->last_period; | |
5873 | u64 nr, offset; | |
5874 | s64 old, val; | |
5875 | ||
5876 | hwc->last_period = hwc->sample_period; | |
5877 | ||
5878 | again: | |
5879 | old = val = local64_read(&hwc->period_left); | |
5880 | if (val < 0) | |
5881 | return 0; | |
5882 | ||
5883 | nr = div64_u64(period + val, period); | |
5884 | offset = nr * period; | |
5885 | val -= offset; | |
5886 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) | |
5887 | goto again; | |
5888 | ||
5889 | return nr; | |
5890 | } | |
5891 | ||
5892 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, | |
5893 | struct perf_sample_data *data, | |
5894 | struct pt_regs *regs) | |
5895 | { | |
5896 | struct hw_perf_event *hwc = &event->hw; | |
5897 | int throttle = 0; | |
5898 | ||
5899 | if (!overflow) | |
5900 | overflow = perf_swevent_set_period(event); | |
5901 | ||
5902 | if (hwc->interrupts == MAX_INTERRUPTS) | |
5903 | return; | |
5904 | ||
5905 | for (; overflow; overflow--) { | |
5906 | if (__perf_event_overflow(event, throttle, | |
5907 | data, regs)) { | |
5908 | /* | |
5909 | * We inhibit the overflow from happening when | |
5910 | * hwc->interrupts == MAX_INTERRUPTS. | |
5911 | */ | |
5912 | break; | |
5913 | } | |
5914 | throttle = 1; | |
5915 | } | |
5916 | } | |
5917 | ||
5918 | static void perf_swevent_event(struct perf_event *event, u64 nr, | |
5919 | struct perf_sample_data *data, | |
5920 | struct pt_regs *regs) | |
5921 | { | |
5922 | struct hw_perf_event *hwc = &event->hw; | |
5923 | ||
5924 | local64_add(nr, &event->count); | |
5925 | ||
5926 | if (!regs) | |
5927 | return; | |
5928 | ||
5929 | if (!is_sampling_event(event)) | |
5930 | return; | |
5931 | ||
5932 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { | |
5933 | data->period = nr; | |
5934 | return perf_swevent_overflow(event, 1, data, regs); | |
5935 | } else | |
5936 | data->period = event->hw.last_period; | |
5937 | ||
5938 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) | |
5939 | return perf_swevent_overflow(event, 1, data, regs); | |
5940 | ||
5941 | if (local64_add_negative(nr, &hwc->period_left)) | |
5942 | return; | |
5943 | ||
5944 | perf_swevent_overflow(event, 0, data, regs); | |
5945 | } | |
5946 | ||
5947 | static int perf_exclude_event(struct perf_event *event, | |
5948 | struct pt_regs *regs) | |
5949 | { | |
5950 | if (event->hw.state & PERF_HES_STOPPED) | |
5951 | return 1; | |
5952 | ||
5953 | if (regs) { | |
5954 | if (event->attr.exclude_user && user_mode(regs)) | |
5955 | return 1; | |
5956 | ||
5957 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
5958 | return 1; | |
5959 | } | |
5960 | ||
5961 | return 0; | |
5962 | } | |
5963 | ||
5964 | static int perf_swevent_match(struct perf_event *event, | |
5965 | enum perf_type_id type, | |
5966 | u32 event_id, | |
5967 | struct perf_sample_data *data, | |
5968 | struct pt_regs *regs) | |
5969 | { | |
5970 | if (event->attr.type != type) | |
5971 | return 0; | |
5972 | ||
5973 | if (event->attr.config != event_id) | |
5974 | return 0; | |
5975 | ||
5976 | if (perf_exclude_event(event, regs)) | |
5977 | return 0; | |
5978 | ||
5979 | return 1; | |
5980 | } | |
5981 | ||
5982 | static inline u64 swevent_hash(u64 type, u32 event_id) | |
5983 | { | |
5984 | u64 val = event_id | (type << 32); | |
5985 | ||
5986 | return hash_64(val, SWEVENT_HLIST_BITS); | |
5987 | } | |
5988 | ||
5989 | static inline struct hlist_head * | |
5990 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
5991 | { | |
5992 | u64 hash = swevent_hash(type, event_id); | |
5993 | ||
5994 | return &hlist->heads[hash]; | |
5995 | } | |
5996 | ||
5997 | /* For the read side: events when they trigger */ | |
5998 | static inline struct hlist_head * | |
5999 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) | |
6000 | { | |
6001 | struct swevent_hlist *hlist; | |
6002 | ||
6003 | hlist = rcu_dereference(swhash->swevent_hlist); | |
6004 | if (!hlist) | |
6005 | return NULL; | |
6006 | ||
6007 | return __find_swevent_head(hlist, type, event_id); | |
6008 | } | |
6009 | ||
6010 | /* For the event head insertion and removal in the hlist */ | |
6011 | static inline struct hlist_head * | |
6012 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) | |
6013 | { | |
6014 | struct swevent_hlist *hlist; | |
6015 | u32 event_id = event->attr.config; | |
6016 | u64 type = event->attr.type; | |
6017 | ||
6018 | /* | |
6019 | * Event scheduling is always serialized against hlist allocation | |
6020 | * and release. Which makes the protected version suitable here. | |
6021 | * The context lock guarantees that. | |
6022 | */ | |
6023 | hlist = rcu_dereference_protected(swhash->swevent_hlist, | |
6024 | lockdep_is_held(&event->ctx->lock)); | |
6025 | if (!hlist) | |
6026 | return NULL; | |
6027 | ||
6028 | return __find_swevent_head(hlist, type, event_id); | |
6029 | } | |
6030 | ||
6031 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
6032 | u64 nr, | |
6033 | struct perf_sample_data *data, | |
6034 | struct pt_regs *regs) | |
6035 | { | |
6036 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); | |
6037 | struct perf_event *event; | |
6038 | struct hlist_head *head; | |
6039 | ||
6040 | rcu_read_lock(); | |
6041 | head = find_swevent_head_rcu(swhash, type, event_id); | |
6042 | if (!head) | |
6043 | goto end; | |
6044 | ||
6045 | hlist_for_each_entry_rcu(event, head, hlist_entry) { | |
6046 | if (perf_swevent_match(event, type, event_id, data, regs)) | |
6047 | perf_swevent_event(event, nr, data, regs); | |
6048 | } | |
6049 | end: | |
6050 | rcu_read_unlock(); | |
6051 | } | |
6052 | ||
6053 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); | |
6054 | ||
6055 | int perf_swevent_get_recursion_context(void) | |
6056 | { | |
6057 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); | |
6058 | ||
6059 | return get_recursion_context(swhash->recursion); | |
6060 | } | |
6061 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); | |
6062 | ||
6063 | inline void perf_swevent_put_recursion_context(int rctx) | |
6064 | { | |
6065 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); | |
6066 | ||
6067 | put_recursion_context(swhash->recursion, rctx); | |
6068 | } | |
6069 | ||
6070 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6071 | { | |
6072 | struct perf_sample_data data; | |
6073 | ||
6074 | if (WARN_ON_ONCE(!regs)) | |
6075 | return; | |
6076 | ||
6077 | perf_sample_data_init(&data, addr, 0); | |
6078 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); | |
6079 | } | |
6080 | ||
6081 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6082 | { | |
6083 | int rctx; | |
6084 | ||
6085 | preempt_disable_notrace(); | |
6086 | rctx = perf_swevent_get_recursion_context(); | |
6087 | if (unlikely(rctx < 0)) | |
6088 | goto fail; | |
6089 | ||
6090 | ___perf_sw_event(event_id, nr, regs, addr); | |
6091 | ||
6092 | perf_swevent_put_recursion_context(rctx); | |
6093 | fail: | |
6094 | preempt_enable_notrace(); | |
6095 | } | |
6096 | ||
6097 | static void perf_swevent_read(struct perf_event *event) | |
6098 | { | |
6099 | } | |
6100 | ||
6101 | static int perf_swevent_add(struct perf_event *event, int flags) | |
6102 | { | |
6103 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); | |
6104 | struct hw_perf_event *hwc = &event->hw; | |
6105 | struct hlist_head *head; | |
6106 | ||
6107 | if (is_sampling_event(event)) { | |
6108 | hwc->last_period = hwc->sample_period; | |
6109 | perf_swevent_set_period(event); | |
6110 | } | |
6111 | ||
6112 | hwc->state = !(flags & PERF_EF_START); | |
6113 | ||
6114 | head = find_swevent_head(swhash, event); | |
6115 | if (!head) { | |
6116 | /* | |
6117 | * We can race with cpu hotplug code. Do not | |
6118 | * WARN if the cpu just got unplugged. | |
6119 | */ | |
6120 | WARN_ON_ONCE(swhash->online); | |
6121 | return -EINVAL; | |
6122 | } | |
6123 | ||
6124 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6125 | ||
6126 | return 0; | |
6127 | } | |
6128 | ||
6129 | static void perf_swevent_del(struct perf_event *event, int flags) | |
6130 | { | |
6131 | hlist_del_rcu(&event->hlist_entry); | |
6132 | } | |
6133 | ||
6134 | static void perf_swevent_start(struct perf_event *event, int flags) | |
6135 | { | |
6136 | event->hw.state = 0; | |
6137 | } | |
6138 | ||
6139 | static void perf_swevent_stop(struct perf_event *event, int flags) | |
6140 | { | |
6141 | event->hw.state = PERF_HES_STOPPED; | |
6142 | } | |
6143 | ||
6144 | /* Deref the hlist from the update side */ | |
6145 | static inline struct swevent_hlist * | |
6146 | swevent_hlist_deref(struct swevent_htable *swhash) | |
6147 | { | |
6148 | return rcu_dereference_protected(swhash->swevent_hlist, | |
6149 | lockdep_is_held(&swhash->hlist_mutex)); | |
6150 | } | |
6151 | ||
6152 | static void swevent_hlist_release(struct swevent_htable *swhash) | |
6153 | { | |
6154 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); | |
6155 | ||
6156 | if (!hlist) | |
6157 | return; | |
6158 | ||
6159 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); | |
6160 | kfree_rcu(hlist, rcu_head); | |
6161 | } | |
6162 | ||
6163 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6164 | { | |
6165 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); | |
6166 | ||
6167 | mutex_lock(&swhash->hlist_mutex); | |
6168 | ||
6169 | if (!--swhash->hlist_refcount) | |
6170 | swevent_hlist_release(swhash); | |
6171 | ||
6172 | mutex_unlock(&swhash->hlist_mutex); | |
6173 | } | |
6174 | ||
6175 | static void swevent_hlist_put(struct perf_event *event) | |
6176 | { | |
6177 | int cpu; | |
6178 | ||
6179 | for_each_possible_cpu(cpu) | |
6180 | swevent_hlist_put_cpu(event, cpu); | |
6181 | } | |
6182 | ||
6183 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6184 | { | |
6185 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); | |
6186 | int err = 0; | |
6187 | ||
6188 | mutex_lock(&swhash->hlist_mutex); | |
6189 | ||
6190 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { | |
6191 | struct swevent_hlist *hlist; | |
6192 | ||
6193 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6194 | if (!hlist) { | |
6195 | err = -ENOMEM; | |
6196 | goto exit; | |
6197 | } | |
6198 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
6199 | } | |
6200 | swhash->hlist_refcount++; | |
6201 | exit: | |
6202 | mutex_unlock(&swhash->hlist_mutex); | |
6203 | ||
6204 | return err; | |
6205 | } | |
6206 | ||
6207 | static int swevent_hlist_get(struct perf_event *event) | |
6208 | { | |
6209 | int err; | |
6210 | int cpu, failed_cpu; | |
6211 | ||
6212 | get_online_cpus(); | |
6213 | for_each_possible_cpu(cpu) { | |
6214 | err = swevent_hlist_get_cpu(event, cpu); | |
6215 | if (err) { | |
6216 | failed_cpu = cpu; | |
6217 | goto fail; | |
6218 | } | |
6219 | } | |
6220 | put_online_cpus(); | |
6221 | ||
6222 | return 0; | |
6223 | fail: | |
6224 | for_each_possible_cpu(cpu) { | |
6225 | if (cpu == failed_cpu) | |
6226 | break; | |
6227 | swevent_hlist_put_cpu(event, cpu); | |
6228 | } | |
6229 | ||
6230 | put_online_cpus(); | |
6231 | return err; | |
6232 | } | |
6233 | ||
6234 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; | |
6235 | ||
6236 | static void sw_perf_event_destroy(struct perf_event *event) | |
6237 | { | |
6238 | u64 event_id = event->attr.config; | |
6239 | ||
6240 | WARN_ON(event->parent); | |
6241 | ||
6242 | static_key_slow_dec(&perf_swevent_enabled[event_id]); | |
6243 | swevent_hlist_put(event); | |
6244 | } | |
6245 | ||
6246 | static int perf_swevent_init(struct perf_event *event) | |
6247 | { | |
6248 | u64 event_id = event->attr.config; | |
6249 | ||
6250 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6251 | return -ENOENT; | |
6252 | ||
6253 | /* | |
6254 | * no branch sampling for software events | |
6255 | */ | |
6256 | if (has_branch_stack(event)) | |
6257 | return -EOPNOTSUPP; | |
6258 | ||
6259 | switch (event_id) { | |
6260 | case PERF_COUNT_SW_CPU_CLOCK: | |
6261 | case PERF_COUNT_SW_TASK_CLOCK: | |
6262 | return -ENOENT; | |
6263 | ||
6264 | default: | |
6265 | break; | |
6266 | } | |
6267 | ||
6268 | if (event_id >= PERF_COUNT_SW_MAX) | |
6269 | return -ENOENT; | |
6270 | ||
6271 | if (!event->parent) { | |
6272 | int err; | |
6273 | ||
6274 | err = swevent_hlist_get(event); | |
6275 | if (err) | |
6276 | return err; | |
6277 | ||
6278 | static_key_slow_inc(&perf_swevent_enabled[event_id]); | |
6279 | event->destroy = sw_perf_event_destroy; | |
6280 | } | |
6281 | ||
6282 | return 0; | |
6283 | } | |
6284 | ||
6285 | static struct pmu perf_swevent = { | |
6286 | .task_ctx_nr = perf_sw_context, | |
6287 | ||
6288 | .event_init = perf_swevent_init, | |
6289 | .add = perf_swevent_add, | |
6290 | .del = perf_swevent_del, | |
6291 | .start = perf_swevent_start, | |
6292 | .stop = perf_swevent_stop, | |
6293 | .read = perf_swevent_read, | |
6294 | }; | |
6295 | ||
6296 | #ifdef CONFIG_EVENT_TRACING | |
6297 | ||
6298 | static int perf_tp_filter_match(struct perf_event *event, | |
6299 | struct perf_sample_data *data) | |
6300 | { | |
6301 | void *record = data->raw->data; | |
6302 | ||
6303 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) | |
6304 | return 1; | |
6305 | return 0; | |
6306 | } | |
6307 | ||
6308 | static int perf_tp_event_match(struct perf_event *event, | |
6309 | struct perf_sample_data *data, | |
6310 | struct pt_regs *regs) | |
6311 | { | |
6312 | if (event->hw.state & PERF_HES_STOPPED) | |
6313 | return 0; | |
6314 | /* | |
6315 | * All tracepoints are from kernel-space. | |
6316 | */ | |
6317 | if (event->attr.exclude_kernel) | |
6318 | return 0; | |
6319 | ||
6320 | if (!perf_tp_filter_match(event, data)) | |
6321 | return 0; | |
6322 | ||
6323 | return 1; | |
6324 | } | |
6325 | ||
6326 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
6327 | struct pt_regs *regs, struct hlist_head *head, int rctx, | |
6328 | struct task_struct *task) | |
6329 | { | |
6330 | struct perf_sample_data data; | |
6331 | struct perf_event *event; | |
6332 | ||
6333 | struct perf_raw_record raw = { | |
6334 | .size = entry_size, | |
6335 | .data = record, | |
6336 | }; | |
6337 | ||
6338 | perf_sample_data_init(&data, addr, 0); | |
6339 | data.raw = &raw; | |
6340 | ||
6341 | hlist_for_each_entry_rcu(event, head, hlist_entry) { | |
6342 | if (perf_tp_event_match(event, &data, regs)) | |
6343 | perf_swevent_event(event, count, &data, regs); | |
6344 | } | |
6345 | ||
6346 | /* | |
6347 | * If we got specified a target task, also iterate its context and | |
6348 | * deliver this event there too. | |
6349 | */ | |
6350 | if (task && task != current) { | |
6351 | struct perf_event_context *ctx; | |
6352 | struct trace_entry *entry = record; | |
6353 | ||
6354 | rcu_read_lock(); | |
6355 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6356 | if (!ctx) | |
6357 | goto unlock; | |
6358 | ||
6359 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6360 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6361 | continue; | |
6362 | if (event->attr.config != entry->type) | |
6363 | continue; | |
6364 | if (perf_tp_event_match(event, &data, regs)) | |
6365 | perf_swevent_event(event, count, &data, regs); | |
6366 | } | |
6367 | unlock: | |
6368 | rcu_read_unlock(); | |
6369 | } | |
6370 | ||
6371 | perf_swevent_put_recursion_context(rctx); | |
6372 | } | |
6373 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6374 | ||
6375 | static void tp_perf_event_destroy(struct perf_event *event) | |
6376 | { | |
6377 | perf_trace_destroy(event); | |
6378 | } | |
6379 | ||
6380 | static int perf_tp_event_init(struct perf_event *event) | |
6381 | { | |
6382 | int err; | |
6383 | ||
6384 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6385 | return -ENOENT; | |
6386 | ||
6387 | /* | |
6388 | * no branch sampling for tracepoint events | |
6389 | */ | |
6390 | if (has_branch_stack(event)) | |
6391 | return -EOPNOTSUPP; | |
6392 | ||
6393 | err = perf_trace_init(event); | |
6394 | if (err) | |
6395 | return err; | |
6396 | ||
6397 | event->destroy = tp_perf_event_destroy; | |
6398 | ||
6399 | return 0; | |
6400 | } | |
6401 | ||
6402 | static struct pmu perf_tracepoint = { | |
6403 | .task_ctx_nr = perf_sw_context, | |
6404 | ||
6405 | .event_init = perf_tp_event_init, | |
6406 | .add = perf_trace_add, | |
6407 | .del = perf_trace_del, | |
6408 | .start = perf_swevent_start, | |
6409 | .stop = perf_swevent_stop, | |
6410 | .read = perf_swevent_read, | |
6411 | }; | |
6412 | ||
6413 | static inline void perf_tp_register(void) | |
6414 | { | |
6415 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); | |
6416 | } | |
6417 | ||
6418 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6419 | { | |
6420 | char *filter_str; | |
6421 | int ret; | |
6422 | ||
6423 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6424 | return -EINVAL; | |
6425 | ||
6426 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6427 | if (IS_ERR(filter_str)) | |
6428 | return PTR_ERR(filter_str); | |
6429 | ||
6430 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6431 | ||
6432 | kfree(filter_str); | |
6433 | return ret; | |
6434 | } | |
6435 | ||
6436 | static void perf_event_free_filter(struct perf_event *event) | |
6437 | { | |
6438 | ftrace_profile_free_filter(event); | |
6439 | } | |
6440 | ||
6441 | #else | |
6442 | ||
6443 | static inline void perf_tp_register(void) | |
6444 | { | |
6445 | } | |
6446 | ||
6447 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6448 | { | |
6449 | return -ENOENT; | |
6450 | } | |
6451 | ||
6452 | static void perf_event_free_filter(struct perf_event *event) | |
6453 | { | |
6454 | } | |
6455 | ||
6456 | #endif /* CONFIG_EVENT_TRACING */ | |
6457 | ||
6458 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
6459 | void perf_bp_event(struct perf_event *bp, void *data) | |
6460 | { | |
6461 | struct perf_sample_data sample; | |
6462 | struct pt_regs *regs = data; | |
6463 | ||
6464 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); | |
6465 | ||
6466 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) | |
6467 | perf_swevent_event(bp, 1, &sample, regs); | |
6468 | } | |
6469 | #endif | |
6470 | ||
6471 | /* | |
6472 | * hrtimer based swevent callback | |
6473 | */ | |
6474 | ||
6475 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) | |
6476 | { | |
6477 | enum hrtimer_restart ret = HRTIMER_RESTART; | |
6478 | struct perf_sample_data data; | |
6479 | struct pt_regs *regs; | |
6480 | struct perf_event *event; | |
6481 | u64 period; | |
6482 | ||
6483 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); | |
6484 | ||
6485 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
6486 | return HRTIMER_NORESTART; | |
6487 | ||
6488 | event->pmu->read(event); | |
6489 | ||
6490 | perf_sample_data_init(&data, 0, event->hw.last_period); | |
6491 | regs = get_irq_regs(); | |
6492 | ||
6493 | if (regs && !perf_exclude_event(event, regs)) { | |
6494 | if (!(event->attr.exclude_idle && is_idle_task(current))) | |
6495 | if (__perf_event_overflow(event, 1, &data, regs)) | |
6496 | ret = HRTIMER_NORESTART; | |
6497 | } | |
6498 | ||
6499 | period = max_t(u64, 10000, event->hw.sample_period); | |
6500 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
6501 | ||
6502 | return ret; | |
6503 | } | |
6504 | ||
6505 | static void perf_swevent_start_hrtimer(struct perf_event *event) | |
6506 | { | |
6507 | struct hw_perf_event *hwc = &event->hw; | |
6508 | s64 period; | |
6509 | ||
6510 | if (!is_sampling_event(event)) | |
6511 | return; | |
6512 | ||
6513 | period = local64_read(&hwc->period_left); | |
6514 | if (period) { | |
6515 | if (period < 0) | |
6516 | period = 10000; | |
6517 | ||
6518 | local64_set(&hwc->period_left, 0); | |
6519 | } else { | |
6520 | period = max_t(u64, 10000, hwc->sample_period); | |
6521 | } | |
6522 | __hrtimer_start_range_ns(&hwc->hrtimer, | |
6523 | ns_to_ktime(period), 0, | |
6524 | HRTIMER_MODE_REL_PINNED, 0); | |
6525 | } | |
6526 | ||
6527 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
6528 | { | |
6529 | struct hw_perf_event *hwc = &event->hw; | |
6530 | ||
6531 | if (is_sampling_event(event)) { | |
6532 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); | |
6533 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); | |
6534 | ||
6535 | hrtimer_cancel(&hwc->hrtimer); | |
6536 | } | |
6537 | } | |
6538 | ||
6539 | static void perf_swevent_init_hrtimer(struct perf_event *event) | |
6540 | { | |
6541 | struct hw_perf_event *hwc = &event->hw; | |
6542 | ||
6543 | if (!is_sampling_event(event)) | |
6544 | return; | |
6545 | ||
6546 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
6547 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
6548 | ||
6549 | /* | |
6550 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
6551 | * mapping and avoid the whole period adjust feedback stuff. | |
6552 | */ | |
6553 | if (event->attr.freq) { | |
6554 | long freq = event->attr.sample_freq; | |
6555 | ||
6556 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
6557 | hwc->sample_period = event->attr.sample_period; | |
6558 | local64_set(&hwc->period_left, hwc->sample_period); | |
6559 | hwc->last_period = hwc->sample_period; | |
6560 | event->attr.freq = 0; | |
6561 | } | |
6562 | } | |
6563 | ||
6564 | /* | |
6565 | * Software event: cpu wall time clock | |
6566 | */ | |
6567 | ||
6568 | static void cpu_clock_event_update(struct perf_event *event) | |
6569 | { | |
6570 | s64 prev; | |
6571 | u64 now; | |
6572 | ||
6573 | now = local_clock(); | |
6574 | prev = local64_xchg(&event->hw.prev_count, now); | |
6575 | local64_add(now - prev, &event->count); | |
6576 | } | |
6577 | ||
6578 | static void cpu_clock_event_start(struct perf_event *event, int flags) | |
6579 | { | |
6580 | local64_set(&event->hw.prev_count, local_clock()); | |
6581 | perf_swevent_start_hrtimer(event); | |
6582 | } | |
6583 | ||
6584 | static void cpu_clock_event_stop(struct perf_event *event, int flags) | |
6585 | { | |
6586 | perf_swevent_cancel_hrtimer(event); | |
6587 | cpu_clock_event_update(event); | |
6588 | } | |
6589 | ||
6590 | static int cpu_clock_event_add(struct perf_event *event, int flags) | |
6591 | { | |
6592 | if (flags & PERF_EF_START) | |
6593 | cpu_clock_event_start(event, flags); | |
6594 | ||
6595 | return 0; | |
6596 | } | |
6597 | ||
6598 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
6599 | { | |
6600 | cpu_clock_event_stop(event, flags); | |
6601 | } | |
6602 | ||
6603 | static void cpu_clock_event_read(struct perf_event *event) | |
6604 | { | |
6605 | cpu_clock_event_update(event); | |
6606 | } | |
6607 | ||
6608 | static int cpu_clock_event_init(struct perf_event *event) | |
6609 | { | |
6610 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6611 | return -ENOENT; | |
6612 | ||
6613 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
6614 | return -ENOENT; | |
6615 | ||
6616 | /* | |
6617 | * no branch sampling for software events | |
6618 | */ | |
6619 | if (has_branch_stack(event)) | |
6620 | return -EOPNOTSUPP; | |
6621 | ||
6622 | perf_swevent_init_hrtimer(event); | |
6623 | ||
6624 | return 0; | |
6625 | } | |
6626 | ||
6627 | static struct pmu perf_cpu_clock = { | |
6628 | .task_ctx_nr = perf_sw_context, | |
6629 | ||
6630 | .event_init = cpu_clock_event_init, | |
6631 | .add = cpu_clock_event_add, | |
6632 | .del = cpu_clock_event_del, | |
6633 | .start = cpu_clock_event_start, | |
6634 | .stop = cpu_clock_event_stop, | |
6635 | .read = cpu_clock_event_read, | |
6636 | }; | |
6637 | ||
6638 | /* | |
6639 | * Software event: task time clock | |
6640 | */ | |
6641 | ||
6642 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
6643 | { | |
6644 | u64 prev; | |
6645 | s64 delta; | |
6646 | ||
6647 | prev = local64_xchg(&event->hw.prev_count, now); | |
6648 | delta = now - prev; | |
6649 | local64_add(delta, &event->count); | |
6650 | } | |
6651 | ||
6652 | static void task_clock_event_start(struct perf_event *event, int flags) | |
6653 | { | |
6654 | local64_set(&event->hw.prev_count, event->ctx->time); | |
6655 | perf_swevent_start_hrtimer(event); | |
6656 | } | |
6657 | ||
6658 | static void task_clock_event_stop(struct perf_event *event, int flags) | |
6659 | { | |
6660 | perf_swevent_cancel_hrtimer(event); | |
6661 | task_clock_event_update(event, event->ctx->time); | |
6662 | } | |
6663 | ||
6664 | static int task_clock_event_add(struct perf_event *event, int flags) | |
6665 | { | |
6666 | if (flags & PERF_EF_START) | |
6667 | task_clock_event_start(event, flags); | |
6668 | ||
6669 | return 0; | |
6670 | } | |
6671 | ||
6672 | static void task_clock_event_del(struct perf_event *event, int flags) | |
6673 | { | |
6674 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
6675 | } | |
6676 | ||
6677 | static void task_clock_event_read(struct perf_event *event) | |
6678 | { | |
6679 | u64 now = perf_clock(); | |
6680 | u64 delta = now - event->ctx->timestamp; | |
6681 | u64 time = event->ctx->time + delta; | |
6682 | ||
6683 | task_clock_event_update(event, time); | |
6684 | } | |
6685 | ||
6686 | static int task_clock_event_init(struct perf_event *event) | |
6687 | { | |
6688 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6689 | return -ENOENT; | |
6690 | ||
6691 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
6692 | return -ENOENT; | |
6693 | ||
6694 | /* | |
6695 | * no branch sampling for software events | |
6696 | */ | |
6697 | if (has_branch_stack(event)) | |
6698 | return -EOPNOTSUPP; | |
6699 | ||
6700 | perf_swevent_init_hrtimer(event); | |
6701 | ||
6702 | return 0; | |
6703 | } | |
6704 | ||
6705 | static struct pmu perf_task_clock = { | |
6706 | .task_ctx_nr = perf_sw_context, | |
6707 | ||
6708 | .event_init = task_clock_event_init, | |
6709 | .add = task_clock_event_add, | |
6710 | .del = task_clock_event_del, | |
6711 | .start = task_clock_event_start, | |
6712 | .stop = task_clock_event_stop, | |
6713 | .read = task_clock_event_read, | |
6714 | }; | |
6715 | ||
6716 | static void perf_pmu_nop_void(struct pmu *pmu) | |
6717 | { | |
6718 | } | |
6719 | ||
6720 | static int perf_pmu_nop_int(struct pmu *pmu) | |
6721 | { | |
6722 | return 0; | |
6723 | } | |
6724 | ||
6725 | static void perf_pmu_start_txn(struct pmu *pmu) | |
6726 | { | |
6727 | perf_pmu_disable(pmu); | |
6728 | } | |
6729 | ||
6730 | static int perf_pmu_commit_txn(struct pmu *pmu) | |
6731 | { | |
6732 | perf_pmu_enable(pmu); | |
6733 | return 0; | |
6734 | } | |
6735 | ||
6736 | static void perf_pmu_cancel_txn(struct pmu *pmu) | |
6737 | { | |
6738 | perf_pmu_enable(pmu); | |
6739 | } | |
6740 | ||
6741 | static int perf_event_idx_default(struct perf_event *event) | |
6742 | { | |
6743 | return 0; | |
6744 | } | |
6745 | ||
6746 | /* | |
6747 | * Ensures all contexts with the same task_ctx_nr have the same | |
6748 | * pmu_cpu_context too. | |
6749 | */ | |
6750 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) | |
6751 | { | |
6752 | struct pmu *pmu; | |
6753 | ||
6754 | if (ctxn < 0) | |
6755 | return NULL; | |
6756 | ||
6757 | list_for_each_entry(pmu, &pmus, entry) { | |
6758 | if (pmu->task_ctx_nr == ctxn) | |
6759 | return pmu->pmu_cpu_context; | |
6760 | } | |
6761 | ||
6762 | return NULL; | |
6763 | } | |
6764 | ||
6765 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) | |
6766 | { | |
6767 | int cpu; | |
6768 | ||
6769 | for_each_possible_cpu(cpu) { | |
6770 | struct perf_cpu_context *cpuctx; | |
6771 | ||
6772 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
6773 | ||
6774 | if (cpuctx->unique_pmu == old_pmu) | |
6775 | cpuctx->unique_pmu = pmu; | |
6776 | } | |
6777 | } | |
6778 | ||
6779 | static void free_pmu_context(struct pmu *pmu) | |
6780 | { | |
6781 | struct pmu *i; | |
6782 | ||
6783 | mutex_lock(&pmus_lock); | |
6784 | /* | |
6785 | * Like a real lame refcount. | |
6786 | */ | |
6787 | list_for_each_entry(i, &pmus, entry) { | |
6788 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
6789 | update_pmu_context(i, pmu); | |
6790 | goto out; | |
6791 | } | |
6792 | } | |
6793 | ||
6794 | free_percpu(pmu->pmu_cpu_context); | |
6795 | out: | |
6796 | mutex_unlock(&pmus_lock); | |
6797 | } | |
6798 | static struct idr pmu_idr; | |
6799 | ||
6800 | static ssize_t | |
6801 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
6802 | { | |
6803 | struct pmu *pmu = dev_get_drvdata(dev); | |
6804 | ||
6805 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
6806 | } | |
6807 | static DEVICE_ATTR_RO(type); | |
6808 | ||
6809 | static ssize_t | |
6810 | perf_event_mux_interval_ms_show(struct device *dev, | |
6811 | struct device_attribute *attr, | |
6812 | char *page) | |
6813 | { | |
6814 | struct pmu *pmu = dev_get_drvdata(dev); | |
6815 | ||
6816 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
6817 | } | |
6818 | ||
6819 | static ssize_t | |
6820 | perf_event_mux_interval_ms_store(struct device *dev, | |
6821 | struct device_attribute *attr, | |
6822 | const char *buf, size_t count) | |
6823 | { | |
6824 | struct pmu *pmu = dev_get_drvdata(dev); | |
6825 | int timer, cpu, ret; | |
6826 | ||
6827 | ret = kstrtoint(buf, 0, &timer); | |
6828 | if (ret) | |
6829 | return ret; | |
6830 | ||
6831 | if (timer < 1) | |
6832 | return -EINVAL; | |
6833 | ||
6834 | /* same value, noting to do */ | |
6835 | if (timer == pmu->hrtimer_interval_ms) | |
6836 | return count; | |
6837 | ||
6838 | pmu->hrtimer_interval_ms = timer; | |
6839 | ||
6840 | /* update all cpuctx for this PMU */ | |
6841 | for_each_possible_cpu(cpu) { | |
6842 | struct perf_cpu_context *cpuctx; | |
6843 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
6844 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
6845 | ||
6846 | if (hrtimer_active(&cpuctx->hrtimer)) | |
6847 | hrtimer_forward_now(&cpuctx->hrtimer, cpuctx->hrtimer_interval); | |
6848 | } | |
6849 | ||
6850 | return count; | |
6851 | } | |
6852 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); | |
6853 | ||
6854 | static struct attribute *pmu_dev_attrs[] = { | |
6855 | &dev_attr_type.attr, | |
6856 | &dev_attr_perf_event_mux_interval_ms.attr, | |
6857 | NULL, | |
6858 | }; | |
6859 | ATTRIBUTE_GROUPS(pmu_dev); | |
6860 | ||
6861 | static int pmu_bus_running; | |
6862 | static struct bus_type pmu_bus = { | |
6863 | .name = "event_source", | |
6864 | .dev_groups = pmu_dev_groups, | |
6865 | }; | |
6866 | ||
6867 | static void pmu_dev_release(struct device *dev) | |
6868 | { | |
6869 | kfree(dev); | |
6870 | } | |
6871 | ||
6872 | static int pmu_dev_alloc(struct pmu *pmu) | |
6873 | { | |
6874 | int ret = -ENOMEM; | |
6875 | ||
6876 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
6877 | if (!pmu->dev) | |
6878 | goto out; | |
6879 | ||
6880 | pmu->dev->groups = pmu->attr_groups; | |
6881 | device_initialize(pmu->dev); | |
6882 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
6883 | if (ret) | |
6884 | goto free_dev; | |
6885 | ||
6886 | dev_set_drvdata(pmu->dev, pmu); | |
6887 | pmu->dev->bus = &pmu_bus; | |
6888 | pmu->dev->release = pmu_dev_release; | |
6889 | ret = device_add(pmu->dev); | |
6890 | if (ret) | |
6891 | goto free_dev; | |
6892 | ||
6893 | out: | |
6894 | return ret; | |
6895 | ||
6896 | free_dev: | |
6897 | put_device(pmu->dev); | |
6898 | goto out; | |
6899 | } | |
6900 | ||
6901 | static struct lock_class_key cpuctx_mutex; | |
6902 | static struct lock_class_key cpuctx_lock; | |
6903 | ||
6904 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) | |
6905 | { | |
6906 | int cpu, ret; | |
6907 | ||
6908 | mutex_lock(&pmus_lock); | |
6909 | ret = -ENOMEM; | |
6910 | pmu->pmu_disable_count = alloc_percpu(int); | |
6911 | if (!pmu->pmu_disable_count) | |
6912 | goto unlock; | |
6913 | ||
6914 | pmu->type = -1; | |
6915 | if (!name) | |
6916 | goto skip_type; | |
6917 | pmu->name = name; | |
6918 | ||
6919 | if (type < 0) { | |
6920 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); | |
6921 | if (type < 0) { | |
6922 | ret = type; | |
6923 | goto free_pdc; | |
6924 | } | |
6925 | } | |
6926 | pmu->type = type; | |
6927 | ||
6928 | if (pmu_bus_running) { | |
6929 | ret = pmu_dev_alloc(pmu); | |
6930 | if (ret) | |
6931 | goto free_idr; | |
6932 | } | |
6933 | ||
6934 | skip_type: | |
6935 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); | |
6936 | if (pmu->pmu_cpu_context) | |
6937 | goto got_cpu_context; | |
6938 | ||
6939 | ret = -ENOMEM; | |
6940 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); | |
6941 | if (!pmu->pmu_cpu_context) | |
6942 | goto free_dev; | |
6943 | ||
6944 | for_each_possible_cpu(cpu) { | |
6945 | struct perf_cpu_context *cpuctx; | |
6946 | ||
6947 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
6948 | __perf_event_init_context(&cpuctx->ctx); | |
6949 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); | |
6950 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); | |
6951 | cpuctx->ctx.pmu = pmu; | |
6952 | ||
6953 | __perf_cpu_hrtimer_init(cpuctx, cpu); | |
6954 | ||
6955 | cpuctx->unique_pmu = pmu; | |
6956 | } | |
6957 | ||
6958 | got_cpu_context: | |
6959 | if (!pmu->start_txn) { | |
6960 | if (pmu->pmu_enable) { | |
6961 | /* | |
6962 | * If we have pmu_enable/pmu_disable calls, install | |
6963 | * transaction stubs that use that to try and batch | |
6964 | * hardware accesses. | |
6965 | */ | |
6966 | pmu->start_txn = perf_pmu_start_txn; | |
6967 | pmu->commit_txn = perf_pmu_commit_txn; | |
6968 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
6969 | } else { | |
6970 | pmu->start_txn = perf_pmu_nop_void; | |
6971 | pmu->commit_txn = perf_pmu_nop_int; | |
6972 | pmu->cancel_txn = perf_pmu_nop_void; | |
6973 | } | |
6974 | } | |
6975 | ||
6976 | if (!pmu->pmu_enable) { | |
6977 | pmu->pmu_enable = perf_pmu_nop_void; | |
6978 | pmu->pmu_disable = perf_pmu_nop_void; | |
6979 | } | |
6980 | ||
6981 | if (!pmu->event_idx) | |
6982 | pmu->event_idx = perf_event_idx_default; | |
6983 | ||
6984 | list_add_rcu(&pmu->entry, &pmus); | |
6985 | ret = 0; | |
6986 | unlock: | |
6987 | mutex_unlock(&pmus_lock); | |
6988 | ||
6989 | return ret; | |
6990 | ||
6991 | free_dev: | |
6992 | device_del(pmu->dev); | |
6993 | put_device(pmu->dev); | |
6994 | ||
6995 | free_idr: | |
6996 | if (pmu->type >= PERF_TYPE_MAX) | |
6997 | idr_remove(&pmu_idr, pmu->type); | |
6998 | ||
6999 | free_pdc: | |
7000 | free_percpu(pmu->pmu_disable_count); | |
7001 | goto unlock; | |
7002 | } | |
7003 | EXPORT_SYMBOL_GPL(perf_pmu_register); | |
7004 | ||
7005 | void perf_pmu_unregister(struct pmu *pmu) | |
7006 | { | |
7007 | mutex_lock(&pmus_lock); | |
7008 | list_del_rcu(&pmu->entry); | |
7009 | mutex_unlock(&pmus_lock); | |
7010 | ||
7011 | /* | |
7012 | * We dereference the pmu list under both SRCU and regular RCU, so | |
7013 | * synchronize against both of those. | |
7014 | */ | |
7015 | synchronize_srcu(&pmus_srcu); | |
7016 | synchronize_rcu(); | |
7017 | ||
7018 | free_percpu(pmu->pmu_disable_count); | |
7019 | if (pmu->type >= PERF_TYPE_MAX) | |
7020 | idr_remove(&pmu_idr, pmu->type); | |
7021 | device_del(pmu->dev); | |
7022 | put_device(pmu->dev); | |
7023 | free_pmu_context(pmu); | |
7024 | } | |
7025 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); | |
7026 | ||
7027 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) | |
7028 | { | |
7029 | int ret; | |
7030 | ||
7031 | if (!try_module_get(pmu->module)) | |
7032 | return -ENODEV; | |
7033 | event->pmu = pmu; | |
7034 | ret = pmu->event_init(event); | |
7035 | if (ret) | |
7036 | module_put(pmu->module); | |
7037 | ||
7038 | return ret; | |
7039 | } | |
7040 | ||
7041 | struct pmu *perf_init_event(struct perf_event *event) | |
7042 | { | |
7043 | struct pmu *pmu = NULL; | |
7044 | int idx; | |
7045 | int ret; | |
7046 | ||
7047 | idx = srcu_read_lock(&pmus_srcu); | |
7048 | ||
7049 | rcu_read_lock(); | |
7050 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7051 | rcu_read_unlock(); | |
7052 | if (pmu) { | |
7053 | ret = perf_try_init_event(pmu, event); | |
7054 | if (ret) | |
7055 | pmu = ERR_PTR(ret); | |
7056 | goto unlock; | |
7057 | } | |
7058 | ||
7059 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
7060 | ret = perf_try_init_event(pmu, event); | |
7061 | if (!ret) | |
7062 | goto unlock; | |
7063 | ||
7064 | if (ret != -ENOENT) { | |
7065 | pmu = ERR_PTR(ret); | |
7066 | goto unlock; | |
7067 | } | |
7068 | } | |
7069 | pmu = ERR_PTR(-ENOENT); | |
7070 | unlock: | |
7071 | srcu_read_unlock(&pmus_srcu, idx); | |
7072 | ||
7073 | return pmu; | |
7074 | } | |
7075 | ||
7076 | static void account_event_cpu(struct perf_event *event, int cpu) | |
7077 | { | |
7078 | if (event->parent) | |
7079 | return; | |
7080 | ||
7081 | if (has_branch_stack(event)) { | |
7082 | if (!(event->attach_state & PERF_ATTACH_TASK)) | |
7083 | atomic_inc(&per_cpu(perf_branch_stack_events, cpu)); | |
7084 | } | |
7085 | if (is_cgroup_event(event)) | |
7086 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7087 | } | |
7088 | ||
7089 | static void account_event(struct perf_event *event) | |
7090 | { | |
7091 | if (event->parent) | |
7092 | return; | |
7093 | ||
7094 | if (event->attach_state & PERF_ATTACH_TASK) | |
7095 | static_key_slow_inc(&perf_sched_events.key); | |
7096 | if (event->attr.mmap || event->attr.mmap_data) | |
7097 | atomic_inc(&nr_mmap_events); | |
7098 | if (event->attr.comm) | |
7099 | atomic_inc(&nr_comm_events); | |
7100 | if (event->attr.task) | |
7101 | atomic_inc(&nr_task_events); | |
7102 | if (event->attr.freq) { | |
7103 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7104 | tick_nohz_full_kick_all(); | |
7105 | } | |
7106 | if (has_branch_stack(event)) | |
7107 | static_key_slow_inc(&perf_sched_events.key); | |
7108 | if (is_cgroup_event(event)) | |
7109 | static_key_slow_inc(&perf_sched_events.key); | |
7110 | ||
7111 | account_event_cpu(event, event->cpu); | |
7112 | } | |
7113 | ||
7114 | /* | |
7115 | * Allocate and initialize a event structure | |
7116 | */ | |
7117 | static struct perf_event * | |
7118 | perf_event_alloc(struct perf_event_attr *attr, int cpu, | |
7119 | struct task_struct *task, | |
7120 | struct perf_event *group_leader, | |
7121 | struct perf_event *parent_event, | |
7122 | perf_overflow_handler_t overflow_handler, | |
7123 | void *context) | |
7124 | { | |
7125 | struct pmu *pmu; | |
7126 | struct perf_event *event; | |
7127 | struct hw_perf_event *hwc; | |
7128 | long err = -EINVAL; | |
7129 | ||
7130 | if ((unsigned)cpu >= nr_cpu_ids) { | |
7131 | if (!task || cpu != -1) | |
7132 | return ERR_PTR(-EINVAL); | |
7133 | } | |
7134 | ||
7135 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
7136 | if (!event) | |
7137 | return ERR_PTR(-ENOMEM); | |
7138 | ||
7139 | /* | |
7140 | * Single events are their own group leaders, with an | |
7141 | * empty sibling list: | |
7142 | */ | |
7143 | if (!group_leader) | |
7144 | group_leader = event; | |
7145 | ||
7146 | mutex_init(&event->child_mutex); | |
7147 | INIT_LIST_HEAD(&event->child_list); | |
7148 | ||
7149 | INIT_LIST_HEAD(&event->group_entry); | |
7150 | INIT_LIST_HEAD(&event->event_entry); | |
7151 | INIT_LIST_HEAD(&event->sibling_list); | |
7152 | INIT_LIST_HEAD(&event->rb_entry); | |
7153 | INIT_LIST_HEAD(&event->active_entry); | |
7154 | INIT_HLIST_NODE(&event->hlist_entry); | |
7155 | ||
7156 | ||
7157 | init_waitqueue_head(&event->waitq); | |
7158 | init_irq_work(&event->pending, perf_pending_event); | |
7159 | ||
7160 | mutex_init(&event->mmap_mutex); | |
7161 | ||
7162 | atomic_long_set(&event->refcount, 1); | |
7163 | event->cpu = cpu; | |
7164 | event->attr = *attr; | |
7165 | event->group_leader = group_leader; | |
7166 | event->pmu = NULL; | |
7167 | event->oncpu = -1; | |
7168 | ||
7169 | event->parent = parent_event; | |
7170 | ||
7171 | event->ns = get_pid_ns(task_active_pid_ns(current)); | |
7172 | event->id = atomic64_inc_return(&perf_event_id); | |
7173 | ||
7174 | event->state = PERF_EVENT_STATE_INACTIVE; | |
7175 | ||
7176 | if (task) { | |
7177 | event->attach_state = PERF_ATTACH_TASK; | |
7178 | ||
7179 | if (attr->type == PERF_TYPE_TRACEPOINT) | |
7180 | event->hw.tp_target = task; | |
7181 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
7182 | /* | |
7183 | * hw_breakpoint is a bit difficult here.. | |
7184 | */ | |
7185 | else if (attr->type == PERF_TYPE_BREAKPOINT) | |
7186 | event->hw.bp_target = task; | |
7187 | #endif | |
7188 | } | |
7189 | ||
7190 | if (!overflow_handler && parent_event) { | |
7191 | overflow_handler = parent_event->overflow_handler; | |
7192 | context = parent_event->overflow_handler_context; | |
7193 | } | |
7194 | ||
7195 | event->overflow_handler = overflow_handler; | |
7196 | event->overflow_handler_context = context; | |
7197 | ||
7198 | perf_event__state_init(event); | |
7199 | ||
7200 | pmu = NULL; | |
7201 | ||
7202 | hwc = &event->hw; | |
7203 | hwc->sample_period = attr->sample_period; | |
7204 | if (attr->freq && attr->sample_freq) | |
7205 | hwc->sample_period = 1; | |
7206 | hwc->last_period = hwc->sample_period; | |
7207 | ||
7208 | local64_set(&hwc->period_left, hwc->sample_period); | |
7209 | ||
7210 | /* | |
7211 | * we currently do not support PERF_FORMAT_GROUP on inherited events | |
7212 | */ | |
7213 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) | |
7214 | goto err_ns; | |
7215 | ||
7216 | pmu = perf_init_event(event); | |
7217 | if (!pmu) | |
7218 | goto err_ns; | |
7219 | else if (IS_ERR(pmu)) { | |
7220 | err = PTR_ERR(pmu); | |
7221 | goto err_ns; | |
7222 | } | |
7223 | ||
7224 | if (!event->parent) { | |
7225 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { | |
7226 | err = get_callchain_buffers(); | |
7227 | if (err) | |
7228 | goto err_pmu; | |
7229 | } | |
7230 | } | |
7231 | ||
7232 | return event; | |
7233 | ||
7234 | err_pmu: | |
7235 | if (event->destroy) | |
7236 | event->destroy(event); | |
7237 | module_put(pmu->module); | |
7238 | err_ns: | |
7239 | if (event->ns) | |
7240 | put_pid_ns(event->ns); | |
7241 | kfree(event); | |
7242 | ||
7243 | return ERR_PTR(err); | |
7244 | } | |
7245 | ||
7246 | static int perf_copy_attr(struct perf_event_attr __user *uattr, | |
7247 | struct perf_event_attr *attr) | |
7248 | { | |
7249 | u32 size; | |
7250 | int ret; | |
7251 | ||
7252 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7253 | return -EFAULT; | |
7254 | ||
7255 | /* | |
7256 | * zero the full structure, so that a short copy will be nice. | |
7257 | */ | |
7258 | memset(attr, 0, sizeof(*attr)); | |
7259 | ||
7260 | ret = get_user(size, &uattr->size); | |
7261 | if (ret) | |
7262 | return ret; | |
7263 | ||
7264 | if (size > PAGE_SIZE) /* silly large */ | |
7265 | goto err_size; | |
7266 | ||
7267 | if (!size) /* abi compat */ | |
7268 | size = PERF_ATTR_SIZE_VER0; | |
7269 | ||
7270 | if (size < PERF_ATTR_SIZE_VER0) | |
7271 | goto err_size; | |
7272 | ||
7273 | /* | |
7274 | * If we're handed a bigger struct than we know of, | |
7275 | * ensure all the unknown bits are 0 - i.e. new | |
7276 | * user-space does not rely on any kernel feature | |
7277 | * extensions we dont know about yet. | |
7278 | */ | |
7279 | if (size > sizeof(*attr)) { | |
7280 | unsigned char __user *addr; | |
7281 | unsigned char __user *end; | |
7282 | unsigned char val; | |
7283 | ||
7284 | addr = (void __user *)uattr + sizeof(*attr); | |
7285 | end = (void __user *)uattr + size; | |
7286 | ||
7287 | for (; addr < end; addr++) { | |
7288 | ret = get_user(val, addr); | |
7289 | if (ret) | |
7290 | return ret; | |
7291 | if (val) | |
7292 | goto err_size; | |
7293 | } | |
7294 | size = sizeof(*attr); | |
7295 | } | |
7296 | ||
7297 | ret = copy_from_user(attr, uattr, size); | |
7298 | if (ret) | |
7299 | return -EFAULT; | |
7300 | ||
7301 | if (attr->__reserved_1) | |
7302 | return -EINVAL; | |
7303 | ||
7304 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7305 | return -EINVAL; | |
7306 | ||
7307 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
7308 | return -EINVAL; | |
7309 | ||
7310 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
7311 | u64 mask = attr->branch_sample_type; | |
7312 | ||
7313 | /* only using defined bits */ | |
7314 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
7315 | return -EINVAL; | |
7316 | ||
7317 | /* at least one branch bit must be set */ | |
7318 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
7319 | return -EINVAL; | |
7320 | ||
7321 | /* propagate priv level, when not set for branch */ | |
7322 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
7323 | ||
7324 | /* exclude_kernel checked on syscall entry */ | |
7325 | if (!attr->exclude_kernel) | |
7326 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
7327 | ||
7328 | if (!attr->exclude_user) | |
7329 | mask |= PERF_SAMPLE_BRANCH_USER; | |
7330 | ||
7331 | if (!attr->exclude_hv) | |
7332 | mask |= PERF_SAMPLE_BRANCH_HV; | |
7333 | /* | |
7334 | * adjust user setting (for HW filter setup) | |
7335 | */ | |
7336 | attr->branch_sample_type = mask; | |
7337 | } | |
7338 | /* privileged levels capture (kernel, hv): check permissions */ | |
7339 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
7340 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
7341 | return -EACCES; | |
7342 | } | |
7343 | ||
7344 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { | |
7345 | ret = perf_reg_validate(attr->sample_regs_user); | |
7346 | if (ret) | |
7347 | return ret; | |
7348 | } | |
7349 | ||
7350 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
7351 | if (!arch_perf_have_user_stack_dump()) | |
7352 | return -ENOSYS; | |
7353 | ||
7354 | /* | |
7355 | * We have __u32 type for the size, but so far | |
7356 | * we can only use __u16 as maximum due to the | |
7357 | * __u16 sample size limit. | |
7358 | */ | |
7359 | if (attr->sample_stack_user >= USHRT_MAX) | |
7360 | ret = -EINVAL; | |
7361 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
7362 | ret = -EINVAL; | |
7363 | } | |
7364 | ||
7365 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) | |
7366 | ret = perf_reg_validate(attr->sample_regs_intr); | |
7367 | out: | |
7368 | return ret; | |
7369 | ||
7370 | err_size: | |
7371 | put_user(sizeof(*attr), &uattr->size); | |
7372 | ret = -E2BIG; | |
7373 | goto out; | |
7374 | } | |
7375 | ||
7376 | static int | |
7377 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
7378 | { | |
7379 | struct ring_buffer *rb = NULL; | |
7380 | int ret = -EINVAL; | |
7381 | ||
7382 | if (!output_event) | |
7383 | goto set; | |
7384 | ||
7385 | /* don't allow circular references */ | |
7386 | if (event == output_event) | |
7387 | goto out; | |
7388 | ||
7389 | /* | |
7390 | * Don't allow cross-cpu buffers | |
7391 | */ | |
7392 | if (output_event->cpu != event->cpu) | |
7393 | goto out; | |
7394 | ||
7395 | /* | |
7396 | * If its not a per-cpu rb, it must be the same task. | |
7397 | */ | |
7398 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
7399 | goto out; | |
7400 | ||
7401 | set: | |
7402 | mutex_lock(&event->mmap_mutex); | |
7403 | /* Can't redirect output if we've got an active mmap() */ | |
7404 | if (atomic_read(&event->mmap_count)) | |
7405 | goto unlock; | |
7406 | ||
7407 | if (output_event) { | |
7408 | /* get the rb we want to redirect to */ | |
7409 | rb = ring_buffer_get(output_event); | |
7410 | if (!rb) | |
7411 | goto unlock; | |
7412 | } | |
7413 | ||
7414 | ring_buffer_attach(event, rb); | |
7415 | ||
7416 | ret = 0; | |
7417 | unlock: | |
7418 | mutex_unlock(&event->mmap_mutex); | |
7419 | ||
7420 | out: | |
7421 | return ret; | |
7422 | } | |
7423 | ||
7424 | static void mutex_lock_double(struct mutex *a, struct mutex *b) | |
7425 | { | |
7426 | if (b < a) | |
7427 | swap(a, b); | |
7428 | ||
7429 | mutex_lock(a); | |
7430 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
7431 | } | |
7432 | ||
7433 | /** | |
7434 | * sys_perf_event_open - open a performance event, associate it to a task/cpu | |
7435 | * | |
7436 | * @attr_uptr: event_id type attributes for monitoring/sampling | |
7437 | * @pid: target pid | |
7438 | * @cpu: target cpu | |
7439 | * @group_fd: group leader event fd | |
7440 | */ | |
7441 | SYSCALL_DEFINE5(perf_event_open, | |
7442 | struct perf_event_attr __user *, attr_uptr, | |
7443 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) | |
7444 | { | |
7445 | struct perf_event *group_leader = NULL, *output_event = NULL; | |
7446 | struct perf_event *event, *sibling; | |
7447 | struct perf_event_attr attr; | |
7448 | struct perf_event_context *ctx, *uninitialized_var(gctx); | |
7449 | struct file *event_file = NULL; | |
7450 | struct fd group = {NULL, 0}; | |
7451 | struct task_struct *task = NULL; | |
7452 | struct pmu *pmu; | |
7453 | int event_fd; | |
7454 | int move_group = 0; | |
7455 | int err; | |
7456 | int f_flags = O_RDWR; | |
7457 | ||
7458 | /* for future expandability... */ | |
7459 | if (flags & ~PERF_FLAG_ALL) | |
7460 | return -EINVAL; | |
7461 | ||
7462 | err = perf_copy_attr(attr_uptr, &attr); | |
7463 | if (err) | |
7464 | return err; | |
7465 | ||
7466 | if (!attr.exclude_kernel) { | |
7467 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
7468 | return -EACCES; | |
7469 | } | |
7470 | ||
7471 | if (attr.freq) { | |
7472 | if (attr.sample_freq > sysctl_perf_event_sample_rate) | |
7473 | return -EINVAL; | |
7474 | } else { | |
7475 | if (attr.sample_period & (1ULL << 63)) | |
7476 | return -EINVAL; | |
7477 | } | |
7478 | ||
7479 | /* | |
7480 | * In cgroup mode, the pid argument is used to pass the fd | |
7481 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
7482 | * designates the cpu on which to monitor threads from that | |
7483 | * cgroup. | |
7484 | */ | |
7485 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
7486 | return -EINVAL; | |
7487 | ||
7488 | if (flags & PERF_FLAG_FD_CLOEXEC) | |
7489 | f_flags |= O_CLOEXEC; | |
7490 | ||
7491 | event_fd = get_unused_fd_flags(f_flags); | |
7492 | if (event_fd < 0) | |
7493 | return event_fd; | |
7494 | ||
7495 | if (group_fd != -1) { | |
7496 | err = perf_fget_light(group_fd, &group); | |
7497 | if (err) | |
7498 | goto err_fd; | |
7499 | group_leader = group.file->private_data; | |
7500 | if (flags & PERF_FLAG_FD_OUTPUT) | |
7501 | output_event = group_leader; | |
7502 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
7503 | group_leader = NULL; | |
7504 | } | |
7505 | ||
7506 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { | |
7507 | task = find_lively_task_by_vpid(pid); | |
7508 | if (IS_ERR(task)) { | |
7509 | err = PTR_ERR(task); | |
7510 | goto err_group_fd; | |
7511 | } | |
7512 | } | |
7513 | ||
7514 | if (task && group_leader && | |
7515 | group_leader->attr.inherit != attr.inherit) { | |
7516 | err = -EINVAL; | |
7517 | goto err_task; | |
7518 | } | |
7519 | ||
7520 | get_online_cpus(); | |
7521 | ||
7522 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, | |
7523 | NULL, NULL); | |
7524 | if (IS_ERR(event)) { | |
7525 | err = PTR_ERR(event); | |
7526 | goto err_cpus; | |
7527 | } | |
7528 | ||
7529 | if (flags & PERF_FLAG_PID_CGROUP) { | |
7530 | err = perf_cgroup_connect(pid, event, &attr, group_leader); | |
7531 | if (err) { | |
7532 | __free_event(event); | |
7533 | goto err_cpus; | |
7534 | } | |
7535 | } | |
7536 | ||
7537 | if (is_sampling_event(event)) { | |
7538 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
7539 | err = -ENOTSUPP; | |
7540 | goto err_alloc; | |
7541 | } | |
7542 | } | |
7543 | ||
7544 | account_event(event); | |
7545 | ||
7546 | /* | |
7547 | * Special case software events and allow them to be part of | |
7548 | * any hardware group. | |
7549 | */ | |
7550 | pmu = event->pmu; | |
7551 | ||
7552 | if (group_leader && | |
7553 | (is_software_event(event) != is_software_event(group_leader))) { | |
7554 | if (is_software_event(event)) { | |
7555 | /* | |
7556 | * If event and group_leader are not both a software | |
7557 | * event, and event is, then group leader is not. | |
7558 | * | |
7559 | * Allow the addition of software events to !software | |
7560 | * groups, this is safe because software events never | |
7561 | * fail to schedule. | |
7562 | */ | |
7563 | pmu = group_leader->pmu; | |
7564 | } else if (is_software_event(group_leader) && | |
7565 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
7566 | /* | |
7567 | * In case the group is a pure software group, and we | |
7568 | * try to add a hardware event, move the whole group to | |
7569 | * the hardware context. | |
7570 | */ | |
7571 | move_group = 1; | |
7572 | } | |
7573 | } | |
7574 | ||
7575 | /* | |
7576 | * Get the target context (task or percpu): | |
7577 | */ | |
7578 | ctx = find_get_context(pmu, task, event->cpu); | |
7579 | if (IS_ERR(ctx)) { | |
7580 | err = PTR_ERR(ctx); | |
7581 | goto err_alloc; | |
7582 | } | |
7583 | ||
7584 | if (task) { | |
7585 | put_task_struct(task); | |
7586 | task = NULL; | |
7587 | } | |
7588 | ||
7589 | /* | |
7590 | * Look up the group leader (we will attach this event to it): | |
7591 | */ | |
7592 | if (group_leader) { | |
7593 | err = -EINVAL; | |
7594 | ||
7595 | /* | |
7596 | * Do not allow a recursive hierarchy (this new sibling | |
7597 | * becoming part of another group-sibling): | |
7598 | */ | |
7599 | if (group_leader->group_leader != group_leader) | |
7600 | goto err_context; | |
7601 | /* | |
7602 | * Do not allow to attach to a group in a different | |
7603 | * task or CPU context: | |
7604 | */ | |
7605 | if (move_group) { | |
7606 | /* | |
7607 | * Make sure we're both on the same task, or both | |
7608 | * per-cpu events. | |
7609 | */ | |
7610 | if (group_leader->ctx->task != ctx->task) | |
7611 | goto err_context; | |
7612 | ||
7613 | /* | |
7614 | * Make sure we're both events for the same CPU; | |
7615 | * grouping events for different CPUs is broken; since | |
7616 | * you can never concurrently schedule them anyhow. | |
7617 | */ | |
7618 | if (group_leader->cpu != event->cpu) | |
7619 | goto err_context; | |
7620 | } else { | |
7621 | if (group_leader->ctx != ctx) | |
7622 | goto err_context; | |
7623 | } | |
7624 | ||
7625 | /* | |
7626 | * Only a group leader can be exclusive or pinned | |
7627 | */ | |
7628 | if (attr.exclusive || attr.pinned) | |
7629 | goto err_context; | |
7630 | } | |
7631 | ||
7632 | if (output_event) { | |
7633 | err = perf_event_set_output(event, output_event); | |
7634 | if (err) | |
7635 | goto err_context; | |
7636 | } | |
7637 | ||
7638 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, | |
7639 | f_flags); | |
7640 | if (IS_ERR(event_file)) { | |
7641 | err = PTR_ERR(event_file); | |
7642 | goto err_context; | |
7643 | } | |
7644 | ||
7645 | if (move_group) { | |
7646 | gctx = group_leader->ctx; | |
7647 | ||
7648 | /* | |
7649 | * See perf_event_ctx_lock() for comments on the details | |
7650 | * of swizzling perf_event::ctx. | |
7651 | */ | |
7652 | mutex_lock_double(&gctx->mutex, &ctx->mutex); | |
7653 | ||
7654 | perf_remove_from_context(group_leader, false); | |
7655 | ||
7656 | list_for_each_entry(sibling, &group_leader->sibling_list, | |
7657 | group_entry) { | |
7658 | perf_remove_from_context(sibling, false); | |
7659 | put_ctx(gctx); | |
7660 | } | |
7661 | } else { | |
7662 | mutex_lock(&ctx->mutex); | |
7663 | } | |
7664 | ||
7665 | WARN_ON_ONCE(ctx->parent_ctx); | |
7666 | ||
7667 | if (move_group) { | |
7668 | /* | |
7669 | * Wait for everybody to stop referencing the events through | |
7670 | * the old lists, before installing it on new lists. | |
7671 | */ | |
7672 | synchronize_rcu(); | |
7673 | ||
7674 | /* | |
7675 | * Install the group siblings before the group leader. | |
7676 | * | |
7677 | * Because a group leader will try and install the entire group | |
7678 | * (through the sibling list, which is still in-tact), we can | |
7679 | * end up with siblings installed in the wrong context. | |
7680 | * | |
7681 | * By installing siblings first we NO-OP because they're not | |
7682 | * reachable through the group lists. | |
7683 | */ | |
7684 | list_for_each_entry(sibling, &group_leader->sibling_list, | |
7685 | group_entry) { | |
7686 | perf_event__state_init(sibling); | |
7687 | perf_install_in_context(ctx, sibling, sibling->cpu); | |
7688 | get_ctx(ctx); | |
7689 | } | |
7690 | ||
7691 | /* | |
7692 | * Removing from the context ends up with disabled | |
7693 | * event. What we want here is event in the initial | |
7694 | * startup state, ready to be add into new context. | |
7695 | */ | |
7696 | perf_event__state_init(group_leader); | |
7697 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
7698 | get_ctx(ctx); | |
7699 | } | |
7700 | ||
7701 | perf_install_in_context(ctx, event, event->cpu); | |
7702 | perf_unpin_context(ctx); | |
7703 | ||
7704 | if (move_group) { | |
7705 | mutex_unlock(&gctx->mutex); | |
7706 | put_ctx(gctx); | |
7707 | } | |
7708 | mutex_unlock(&ctx->mutex); | |
7709 | ||
7710 | put_online_cpus(); | |
7711 | ||
7712 | event->owner = current; | |
7713 | ||
7714 | mutex_lock(¤t->perf_event_mutex); | |
7715 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
7716 | mutex_unlock(¤t->perf_event_mutex); | |
7717 | ||
7718 | /* | |
7719 | * Precalculate sample_data sizes | |
7720 | */ | |
7721 | perf_event__header_size(event); | |
7722 | perf_event__id_header_size(event); | |
7723 | ||
7724 | /* | |
7725 | * Drop the reference on the group_event after placing the | |
7726 | * new event on the sibling_list. This ensures destruction | |
7727 | * of the group leader will find the pointer to itself in | |
7728 | * perf_group_detach(). | |
7729 | */ | |
7730 | fdput(group); | |
7731 | fd_install(event_fd, event_file); | |
7732 | return event_fd; | |
7733 | ||
7734 | err_context: | |
7735 | perf_unpin_context(ctx); | |
7736 | put_ctx(ctx); | |
7737 | err_alloc: | |
7738 | free_event(event); | |
7739 | err_cpus: | |
7740 | put_online_cpus(); | |
7741 | err_task: | |
7742 | if (task) | |
7743 | put_task_struct(task); | |
7744 | err_group_fd: | |
7745 | fdput(group); | |
7746 | err_fd: | |
7747 | put_unused_fd(event_fd); | |
7748 | return err; | |
7749 | } | |
7750 | ||
7751 | /** | |
7752 | * perf_event_create_kernel_counter | |
7753 | * | |
7754 | * @attr: attributes of the counter to create | |
7755 | * @cpu: cpu in which the counter is bound | |
7756 | * @task: task to profile (NULL for percpu) | |
7757 | */ | |
7758 | struct perf_event * | |
7759 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
7760 | struct task_struct *task, | |
7761 | perf_overflow_handler_t overflow_handler, | |
7762 | void *context) | |
7763 | { | |
7764 | struct perf_event_context *ctx; | |
7765 | struct perf_event *event; | |
7766 | int err; | |
7767 | ||
7768 | /* | |
7769 | * Get the target context (task or percpu): | |
7770 | */ | |
7771 | ||
7772 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, | |
7773 | overflow_handler, context); | |
7774 | if (IS_ERR(event)) { | |
7775 | err = PTR_ERR(event); | |
7776 | goto err; | |
7777 | } | |
7778 | ||
7779 | /* Mark owner so we could distinguish it from user events. */ | |
7780 | event->owner = EVENT_OWNER_KERNEL; | |
7781 | ||
7782 | account_event(event); | |
7783 | ||
7784 | ctx = find_get_context(event->pmu, task, cpu); | |
7785 | if (IS_ERR(ctx)) { | |
7786 | err = PTR_ERR(ctx); | |
7787 | goto err_free; | |
7788 | } | |
7789 | ||
7790 | WARN_ON_ONCE(ctx->parent_ctx); | |
7791 | mutex_lock(&ctx->mutex); | |
7792 | perf_install_in_context(ctx, event, cpu); | |
7793 | perf_unpin_context(ctx); | |
7794 | mutex_unlock(&ctx->mutex); | |
7795 | ||
7796 | return event; | |
7797 | ||
7798 | err_free: | |
7799 | free_event(event); | |
7800 | err: | |
7801 | return ERR_PTR(err); | |
7802 | } | |
7803 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); | |
7804 | ||
7805 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) | |
7806 | { | |
7807 | struct perf_event_context *src_ctx; | |
7808 | struct perf_event_context *dst_ctx; | |
7809 | struct perf_event *event, *tmp; | |
7810 | LIST_HEAD(events); | |
7811 | ||
7812 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
7813 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
7814 | ||
7815 | /* | |
7816 | * See perf_event_ctx_lock() for comments on the details | |
7817 | * of swizzling perf_event::ctx. | |
7818 | */ | |
7819 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
7820 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, | |
7821 | event_entry) { | |
7822 | perf_remove_from_context(event, false); | |
7823 | unaccount_event_cpu(event, src_cpu); | |
7824 | put_ctx(src_ctx); | |
7825 | list_add(&event->migrate_entry, &events); | |
7826 | } | |
7827 | ||
7828 | /* | |
7829 | * Wait for the events to quiesce before re-instating them. | |
7830 | */ | |
7831 | synchronize_rcu(); | |
7832 | ||
7833 | /* | |
7834 | * Re-instate events in 2 passes. | |
7835 | * | |
7836 | * Skip over group leaders and only install siblings on this first | |
7837 | * pass, siblings will not get enabled without a leader, however a | |
7838 | * leader will enable its siblings, even if those are still on the old | |
7839 | * context. | |
7840 | */ | |
7841 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
7842 | if (event->group_leader == event) | |
7843 | continue; | |
7844 | ||
7845 | list_del(&event->migrate_entry); | |
7846 | if (event->state >= PERF_EVENT_STATE_OFF) | |
7847 | event->state = PERF_EVENT_STATE_INACTIVE; | |
7848 | account_event_cpu(event, dst_cpu); | |
7849 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
7850 | get_ctx(dst_ctx); | |
7851 | } | |
7852 | ||
7853 | /* | |
7854 | * Once all the siblings are setup properly, install the group leaders | |
7855 | * to make it go. | |
7856 | */ | |
7857 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
7858 | list_del(&event->migrate_entry); | |
7859 | if (event->state >= PERF_EVENT_STATE_OFF) | |
7860 | event->state = PERF_EVENT_STATE_INACTIVE; | |
7861 | account_event_cpu(event, dst_cpu); | |
7862 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
7863 | get_ctx(dst_ctx); | |
7864 | } | |
7865 | mutex_unlock(&dst_ctx->mutex); | |
7866 | mutex_unlock(&src_ctx->mutex); | |
7867 | } | |
7868 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
7869 | ||
7870 | static void sync_child_event(struct perf_event *child_event, | |
7871 | struct task_struct *child) | |
7872 | { | |
7873 | struct perf_event *parent_event = child_event->parent; | |
7874 | u64 child_val; | |
7875 | ||
7876 | if (child_event->attr.inherit_stat) | |
7877 | perf_event_read_event(child_event, child); | |
7878 | ||
7879 | child_val = perf_event_count(child_event); | |
7880 | ||
7881 | /* | |
7882 | * Add back the child's count to the parent's count: | |
7883 | */ | |
7884 | atomic64_add(child_val, &parent_event->child_count); | |
7885 | atomic64_add(child_event->total_time_enabled, | |
7886 | &parent_event->child_total_time_enabled); | |
7887 | atomic64_add(child_event->total_time_running, | |
7888 | &parent_event->child_total_time_running); | |
7889 | ||
7890 | /* | |
7891 | * Remove this event from the parent's list | |
7892 | */ | |
7893 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
7894 | mutex_lock(&parent_event->child_mutex); | |
7895 | list_del_init(&child_event->child_list); | |
7896 | mutex_unlock(&parent_event->child_mutex); | |
7897 | ||
7898 | /* | |
7899 | * Make sure user/parent get notified, that we just | |
7900 | * lost one event. | |
7901 | */ | |
7902 | perf_event_wakeup(parent_event); | |
7903 | ||
7904 | /* | |
7905 | * Release the parent event, if this was the last | |
7906 | * reference to it. | |
7907 | */ | |
7908 | put_event(parent_event); | |
7909 | } | |
7910 | ||
7911 | static void | |
7912 | __perf_event_exit_task(struct perf_event *child_event, | |
7913 | struct perf_event_context *child_ctx, | |
7914 | struct task_struct *child) | |
7915 | { | |
7916 | /* | |
7917 | * Do not destroy the 'original' grouping; because of the context | |
7918 | * switch optimization the original events could've ended up in a | |
7919 | * random child task. | |
7920 | * | |
7921 | * If we were to destroy the original group, all group related | |
7922 | * operations would cease to function properly after this random | |
7923 | * child dies. | |
7924 | * | |
7925 | * Do destroy all inherited groups, we don't care about those | |
7926 | * and being thorough is better. | |
7927 | */ | |
7928 | perf_remove_from_context(child_event, !!child_event->parent); | |
7929 | ||
7930 | /* | |
7931 | * It can happen that the parent exits first, and has events | |
7932 | * that are still around due to the child reference. These | |
7933 | * events need to be zapped. | |
7934 | */ | |
7935 | if (child_event->parent) { | |
7936 | sync_child_event(child_event, child); | |
7937 | free_event(child_event); | |
7938 | } else { | |
7939 | child_event->state = PERF_EVENT_STATE_EXIT; | |
7940 | perf_event_wakeup(child_event); | |
7941 | } | |
7942 | } | |
7943 | ||
7944 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) | |
7945 | { | |
7946 | struct perf_event *child_event, *next; | |
7947 | struct perf_event_context *child_ctx, *clone_ctx = NULL; | |
7948 | unsigned long flags; | |
7949 | ||
7950 | if (likely(!child->perf_event_ctxp[ctxn])) { | |
7951 | perf_event_task(child, NULL, 0); | |
7952 | return; | |
7953 | } | |
7954 | ||
7955 | local_irq_save(flags); | |
7956 | /* | |
7957 | * We can't reschedule here because interrupts are disabled, | |
7958 | * and either child is current or it is a task that can't be | |
7959 | * scheduled, so we are now safe from rescheduling changing | |
7960 | * our context. | |
7961 | */ | |
7962 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); | |
7963 | ||
7964 | /* | |
7965 | * Take the context lock here so that if find_get_context is | |
7966 | * reading child->perf_event_ctxp, we wait until it has | |
7967 | * incremented the context's refcount before we do put_ctx below. | |
7968 | */ | |
7969 | raw_spin_lock(&child_ctx->lock); | |
7970 | task_ctx_sched_out(child_ctx); | |
7971 | child->perf_event_ctxp[ctxn] = NULL; | |
7972 | ||
7973 | /* | |
7974 | * If this context is a clone; unclone it so it can't get | |
7975 | * swapped to another process while we're removing all | |
7976 | * the events from it. | |
7977 | */ | |
7978 | clone_ctx = unclone_ctx(child_ctx); | |
7979 | update_context_time(child_ctx); | |
7980 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); | |
7981 | ||
7982 | if (clone_ctx) | |
7983 | put_ctx(clone_ctx); | |
7984 | ||
7985 | /* | |
7986 | * Report the task dead after unscheduling the events so that we | |
7987 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
7988 | * get a few PERF_RECORD_READ events. | |
7989 | */ | |
7990 | perf_event_task(child, child_ctx, 0); | |
7991 | ||
7992 | /* | |
7993 | * We can recurse on the same lock type through: | |
7994 | * | |
7995 | * __perf_event_exit_task() | |
7996 | * sync_child_event() | |
7997 | * put_event() | |
7998 | * mutex_lock(&ctx->mutex) | |
7999 | * | |
8000 | * But since its the parent context it won't be the same instance. | |
8001 | */ | |
8002 | mutex_lock(&child_ctx->mutex); | |
8003 | ||
8004 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) | |
8005 | __perf_event_exit_task(child_event, child_ctx, child); | |
8006 | ||
8007 | mutex_unlock(&child_ctx->mutex); | |
8008 | ||
8009 | put_ctx(child_ctx); | |
8010 | } | |
8011 | ||
8012 | /* | |
8013 | * When a child task exits, feed back event values to parent events. | |
8014 | */ | |
8015 | void perf_event_exit_task(struct task_struct *child) | |
8016 | { | |
8017 | struct perf_event *event, *tmp; | |
8018 | int ctxn; | |
8019 | ||
8020 | mutex_lock(&child->perf_event_mutex); | |
8021 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8022 | owner_entry) { | |
8023 | list_del_init(&event->owner_entry); | |
8024 | ||
8025 | /* | |
8026 | * Ensure the list deletion is visible before we clear | |
8027 | * the owner, closes a race against perf_release() where | |
8028 | * we need to serialize on the owner->perf_event_mutex. | |
8029 | */ | |
8030 | smp_wmb(); | |
8031 | event->owner = NULL; | |
8032 | } | |
8033 | mutex_unlock(&child->perf_event_mutex); | |
8034 | ||
8035 | for_each_task_context_nr(ctxn) | |
8036 | perf_event_exit_task_context(child, ctxn); | |
8037 | } | |
8038 | ||
8039 | static void perf_free_event(struct perf_event *event, | |
8040 | struct perf_event_context *ctx) | |
8041 | { | |
8042 | struct perf_event *parent = event->parent; | |
8043 | ||
8044 | if (WARN_ON_ONCE(!parent)) | |
8045 | return; | |
8046 | ||
8047 | mutex_lock(&parent->child_mutex); | |
8048 | list_del_init(&event->child_list); | |
8049 | mutex_unlock(&parent->child_mutex); | |
8050 | ||
8051 | put_event(parent); | |
8052 | ||
8053 | raw_spin_lock_irq(&ctx->lock); | |
8054 | perf_group_detach(event); | |
8055 | list_del_event(event, ctx); | |
8056 | raw_spin_unlock_irq(&ctx->lock); | |
8057 | free_event(event); | |
8058 | } | |
8059 | ||
8060 | /* | |
8061 | * Free an unexposed, unused context as created by inheritance by | |
8062 | * perf_event_init_task below, used by fork() in case of fail. | |
8063 | * | |
8064 | * Not all locks are strictly required, but take them anyway to be nice and | |
8065 | * help out with the lockdep assertions. | |
8066 | */ | |
8067 | void perf_event_free_task(struct task_struct *task) | |
8068 | { | |
8069 | struct perf_event_context *ctx; | |
8070 | struct perf_event *event, *tmp; | |
8071 | int ctxn; | |
8072 | ||
8073 | for_each_task_context_nr(ctxn) { | |
8074 | ctx = task->perf_event_ctxp[ctxn]; | |
8075 | if (!ctx) | |
8076 | continue; | |
8077 | ||
8078 | mutex_lock(&ctx->mutex); | |
8079 | again: | |
8080 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, | |
8081 | group_entry) | |
8082 | perf_free_event(event, ctx); | |
8083 | ||
8084 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, | |
8085 | group_entry) | |
8086 | perf_free_event(event, ctx); | |
8087 | ||
8088 | if (!list_empty(&ctx->pinned_groups) || | |
8089 | !list_empty(&ctx->flexible_groups)) | |
8090 | goto again; | |
8091 | ||
8092 | mutex_unlock(&ctx->mutex); | |
8093 | ||
8094 | put_ctx(ctx); | |
8095 | } | |
8096 | } | |
8097 | ||
8098 | void perf_event_delayed_put(struct task_struct *task) | |
8099 | { | |
8100 | int ctxn; | |
8101 | ||
8102 | for_each_task_context_nr(ctxn) | |
8103 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8104 | } | |
8105 | ||
8106 | /* | |
8107 | * inherit a event from parent task to child task: | |
8108 | */ | |
8109 | static struct perf_event * | |
8110 | inherit_event(struct perf_event *parent_event, | |
8111 | struct task_struct *parent, | |
8112 | struct perf_event_context *parent_ctx, | |
8113 | struct task_struct *child, | |
8114 | struct perf_event *group_leader, | |
8115 | struct perf_event_context *child_ctx) | |
8116 | { | |
8117 | enum perf_event_active_state parent_state = parent_event->state; | |
8118 | struct perf_event *child_event; | |
8119 | unsigned long flags; | |
8120 | ||
8121 | /* | |
8122 | * Instead of creating recursive hierarchies of events, | |
8123 | * we link inherited events back to the original parent, | |
8124 | * which has a filp for sure, which we use as the reference | |
8125 | * count: | |
8126 | */ | |
8127 | if (parent_event->parent) | |
8128 | parent_event = parent_event->parent; | |
8129 | ||
8130 | child_event = perf_event_alloc(&parent_event->attr, | |
8131 | parent_event->cpu, | |
8132 | child, | |
8133 | group_leader, parent_event, | |
8134 | NULL, NULL); | |
8135 | if (IS_ERR(child_event)) | |
8136 | return child_event; | |
8137 | ||
8138 | if (is_orphaned_event(parent_event) || | |
8139 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
8140 | free_event(child_event); | |
8141 | return NULL; | |
8142 | } | |
8143 | ||
8144 | get_ctx(child_ctx); | |
8145 | ||
8146 | /* | |
8147 | * Make the child state follow the state of the parent event, | |
8148 | * not its attr.disabled bit. We hold the parent's mutex, | |
8149 | * so we won't race with perf_event_{en, dis}able_family. | |
8150 | */ | |
8151 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) | |
8152 | child_event->state = PERF_EVENT_STATE_INACTIVE; | |
8153 | else | |
8154 | child_event->state = PERF_EVENT_STATE_OFF; | |
8155 | ||
8156 | if (parent_event->attr.freq) { | |
8157 | u64 sample_period = parent_event->hw.sample_period; | |
8158 | struct hw_perf_event *hwc = &child_event->hw; | |
8159 | ||
8160 | hwc->sample_period = sample_period; | |
8161 | hwc->last_period = sample_period; | |
8162 | ||
8163 | local64_set(&hwc->period_left, sample_period); | |
8164 | } | |
8165 | ||
8166 | child_event->ctx = child_ctx; | |
8167 | child_event->overflow_handler = parent_event->overflow_handler; | |
8168 | child_event->overflow_handler_context | |
8169 | = parent_event->overflow_handler_context; | |
8170 | ||
8171 | /* | |
8172 | * Precalculate sample_data sizes | |
8173 | */ | |
8174 | perf_event__header_size(child_event); | |
8175 | perf_event__id_header_size(child_event); | |
8176 | ||
8177 | /* | |
8178 | * Link it up in the child's context: | |
8179 | */ | |
8180 | raw_spin_lock_irqsave(&child_ctx->lock, flags); | |
8181 | add_event_to_ctx(child_event, child_ctx); | |
8182 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); | |
8183 | ||
8184 | /* | |
8185 | * Link this into the parent event's child list | |
8186 | */ | |
8187 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8188 | mutex_lock(&parent_event->child_mutex); | |
8189 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
8190 | mutex_unlock(&parent_event->child_mutex); | |
8191 | ||
8192 | return child_event; | |
8193 | } | |
8194 | ||
8195 | static int inherit_group(struct perf_event *parent_event, | |
8196 | struct task_struct *parent, | |
8197 | struct perf_event_context *parent_ctx, | |
8198 | struct task_struct *child, | |
8199 | struct perf_event_context *child_ctx) | |
8200 | { | |
8201 | struct perf_event *leader; | |
8202 | struct perf_event *sub; | |
8203 | struct perf_event *child_ctr; | |
8204 | ||
8205 | leader = inherit_event(parent_event, parent, parent_ctx, | |
8206 | child, NULL, child_ctx); | |
8207 | if (IS_ERR(leader)) | |
8208 | return PTR_ERR(leader); | |
8209 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
8210 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
8211 | child, leader, child_ctx); | |
8212 | if (IS_ERR(child_ctr)) | |
8213 | return PTR_ERR(child_ctr); | |
8214 | } | |
8215 | return 0; | |
8216 | } | |
8217 | ||
8218 | static int | |
8219 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
8220 | struct perf_event_context *parent_ctx, | |
8221 | struct task_struct *child, int ctxn, | |
8222 | int *inherited_all) | |
8223 | { | |
8224 | int ret; | |
8225 | struct perf_event_context *child_ctx; | |
8226 | ||
8227 | if (!event->attr.inherit) { | |
8228 | *inherited_all = 0; | |
8229 | return 0; | |
8230 | } | |
8231 | ||
8232 | child_ctx = child->perf_event_ctxp[ctxn]; | |
8233 | if (!child_ctx) { | |
8234 | /* | |
8235 | * This is executed from the parent task context, so | |
8236 | * inherit events that have been marked for cloning. | |
8237 | * First allocate and initialize a context for the | |
8238 | * child. | |
8239 | */ | |
8240 | ||
8241 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); | |
8242 | if (!child_ctx) | |
8243 | return -ENOMEM; | |
8244 | ||
8245 | child->perf_event_ctxp[ctxn] = child_ctx; | |
8246 | } | |
8247 | ||
8248 | ret = inherit_group(event, parent, parent_ctx, | |
8249 | child, child_ctx); | |
8250 | ||
8251 | if (ret) | |
8252 | *inherited_all = 0; | |
8253 | ||
8254 | return ret; | |
8255 | } | |
8256 | ||
8257 | /* | |
8258 | * Initialize the perf_event context in task_struct | |
8259 | */ | |
8260 | static int perf_event_init_context(struct task_struct *child, int ctxn) | |
8261 | { | |
8262 | struct perf_event_context *child_ctx, *parent_ctx; | |
8263 | struct perf_event_context *cloned_ctx; | |
8264 | struct perf_event *event; | |
8265 | struct task_struct *parent = current; | |
8266 | int inherited_all = 1; | |
8267 | unsigned long flags; | |
8268 | int ret = 0; | |
8269 | ||
8270 | if (likely(!parent->perf_event_ctxp[ctxn])) | |
8271 | return 0; | |
8272 | ||
8273 | /* | |
8274 | * If the parent's context is a clone, pin it so it won't get | |
8275 | * swapped under us. | |
8276 | */ | |
8277 | parent_ctx = perf_pin_task_context(parent, ctxn); | |
8278 | if (!parent_ctx) | |
8279 | return 0; | |
8280 | ||
8281 | /* | |
8282 | * No need to check if parent_ctx != NULL here; since we saw | |
8283 | * it non-NULL earlier, the only reason for it to become NULL | |
8284 | * is if we exit, and since we're currently in the middle of | |
8285 | * a fork we can't be exiting at the same time. | |
8286 | */ | |
8287 | ||
8288 | /* | |
8289 | * Lock the parent list. No need to lock the child - not PID | |
8290 | * hashed yet and not running, so nobody can access it. | |
8291 | */ | |
8292 | mutex_lock(&parent_ctx->mutex); | |
8293 | ||
8294 | /* | |
8295 | * We dont have to disable NMIs - we are only looking at | |
8296 | * the list, not manipulating it: | |
8297 | */ | |
8298 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { | |
8299 | ret = inherit_task_group(event, parent, parent_ctx, | |
8300 | child, ctxn, &inherited_all); | |
8301 | if (ret) | |
8302 | break; | |
8303 | } | |
8304 | ||
8305 | /* | |
8306 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
8307 | * to allocations, but we need to prevent rotation because | |
8308 | * rotate_ctx() will change the list from interrupt context. | |
8309 | */ | |
8310 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
8311 | parent_ctx->rotate_disable = 1; | |
8312 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
8313 | ||
8314 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { | |
8315 | ret = inherit_task_group(event, parent, parent_ctx, | |
8316 | child, ctxn, &inherited_all); | |
8317 | if (ret) | |
8318 | break; | |
8319 | } | |
8320 | ||
8321 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
8322 | parent_ctx->rotate_disable = 0; | |
8323 | ||
8324 | child_ctx = child->perf_event_ctxp[ctxn]; | |
8325 | ||
8326 | if (child_ctx && inherited_all) { | |
8327 | /* | |
8328 | * Mark the child context as a clone of the parent | |
8329 | * context, or of whatever the parent is a clone of. | |
8330 | * | |
8331 | * Note that if the parent is a clone, the holding of | |
8332 | * parent_ctx->lock avoids it from being uncloned. | |
8333 | */ | |
8334 | cloned_ctx = parent_ctx->parent_ctx; | |
8335 | if (cloned_ctx) { | |
8336 | child_ctx->parent_ctx = cloned_ctx; | |
8337 | child_ctx->parent_gen = parent_ctx->parent_gen; | |
8338 | } else { | |
8339 | child_ctx->parent_ctx = parent_ctx; | |
8340 | child_ctx->parent_gen = parent_ctx->generation; | |
8341 | } | |
8342 | get_ctx(child_ctx->parent_ctx); | |
8343 | } | |
8344 | ||
8345 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
8346 | mutex_unlock(&parent_ctx->mutex); | |
8347 | ||
8348 | perf_unpin_context(parent_ctx); | |
8349 | put_ctx(parent_ctx); | |
8350 | ||
8351 | return ret; | |
8352 | } | |
8353 | ||
8354 | /* | |
8355 | * Initialize the perf_event context in task_struct | |
8356 | */ | |
8357 | int perf_event_init_task(struct task_struct *child) | |
8358 | { | |
8359 | int ctxn, ret; | |
8360 | ||
8361 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); | |
8362 | mutex_init(&child->perf_event_mutex); | |
8363 | INIT_LIST_HEAD(&child->perf_event_list); | |
8364 | ||
8365 | for_each_task_context_nr(ctxn) { | |
8366 | ret = perf_event_init_context(child, ctxn); | |
8367 | if (ret) { | |
8368 | perf_event_free_task(child); | |
8369 | return ret; | |
8370 | } | |
8371 | } | |
8372 | ||
8373 | return 0; | |
8374 | } | |
8375 | ||
8376 | static void __init perf_event_init_all_cpus(void) | |
8377 | { | |
8378 | struct swevent_htable *swhash; | |
8379 | int cpu; | |
8380 | ||
8381 | for_each_possible_cpu(cpu) { | |
8382 | swhash = &per_cpu(swevent_htable, cpu); | |
8383 | mutex_init(&swhash->hlist_mutex); | |
8384 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); | |
8385 | } | |
8386 | } | |
8387 | ||
8388 | static void perf_event_init_cpu(int cpu) | |
8389 | { | |
8390 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); | |
8391 | ||
8392 | mutex_lock(&swhash->hlist_mutex); | |
8393 | swhash->online = true; | |
8394 | if (swhash->hlist_refcount > 0) { | |
8395 | struct swevent_hlist *hlist; | |
8396 | ||
8397 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); | |
8398 | WARN_ON(!hlist); | |
8399 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
8400 | } | |
8401 | mutex_unlock(&swhash->hlist_mutex); | |
8402 | } | |
8403 | ||
8404 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC | |
8405 | static void __perf_event_exit_context(void *__info) | |
8406 | { | |
8407 | struct remove_event re = { .detach_group = true }; | |
8408 | struct perf_event_context *ctx = __info; | |
8409 | ||
8410 | rcu_read_lock(); | |
8411 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) | |
8412 | __perf_remove_from_context(&re); | |
8413 | rcu_read_unlock(); | |
8414 | } | |
8415 | ||
8416 | static void perf_event_exit_cpu_context(int cpu) | |
8417 | { | |
8418 | struct perf_event_context *ctx; | |
8419 | struct pmu *pmu; | |
8420 | int idx; | |
8421 | ||
8422 | idx = srcu_read_lock(&pmus_srcu); | |
8423 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
8424 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; | |
8425 | ||
8426 | mutex_lock(&ctx->mutex); | |
8427 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
8428 | mutex_unlock(&ctx->mutex); | |
8429 | } | |
8430 | srcu_read_unlock(&pmus_srcu, idx); | |
8431 | } | |
8432 | ||
8433 | static void perf_event_exit_cpu(int cpu) | |
8434 | { | |
8435 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); | |
8436 | ||
8437 | perf_event_exit_cpu_context(cpu); | |
8438 | ||
8439 | mutex_lock(&swhash->hlist_mutex); | |
8440 | swhash->online = false; | |
8441 | swevent_hlist_release(swhash); | |
8442 | mutex_unlock(&swhash->hlist_mutex); | |
8443 | } | |
8444 | #else | |
8445 | static inline void perf_event_exit_cpu(int cpu) { } | |
8446 | #endif | |
8447 | ||
8448 | static int | |
8449 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
8450 | { | |
8451 | int cpu; | |
8452 | ||
8453 | for_each_online_cpu(cpu) | |
8454 | perf_event_exit_cpu(cpu); | |
8455 | ||
8456 | return NOTIFY_OK; | |
8457 | } | |
8458 | ||
8459 | /* | |
8460 | * Run the perf reboot notifier at the very last possible moment so that | |
8461 | * the generic watchdog code runs as long as possible. | |
8462 | */ | |
8463 | static struct notifier_block perf_reboot_notifier = { | |
8464 | .notifier_call = perf_reboot, | |
8465 | .priority = INT_MIN, | |
8466 | }; | |
8467 | ||
8468 | static int | |
8469 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) | |
8470 | { | |
8471 | unsigned int cpu = (long)hcpu; | |
8472 | ||
8473 | switch (action & ~CPU_TASKS_FROZEN) { | |
8474 | ||
8475 | case CPU_UP_PREPARE: | |
8476 | case CPU_DOWN_FAILED: | |
8477 | perf_event_init_cpu(cpu); | |
8478 | break; | |
8479 | ||
8480 | case CPU_UP_CANCELED: | |
8481 | case CPU_DOWN_PREPARE: | |
8482 | perf_event_exit_cpu(cpu); | |
8483 | break; | |
8484 | default: | |
8485 | break; | |
8486 | } | |
8487 | ||
8488 | return NOTIFY_OK; | |
8489 | } | |
8490 | ||
8491 | void __init perf_event_init(void) | |
8492 | { | |
8493 | int ret; | |
8494 | ||
8495 | idr_init(&pmu_idr); | |
8496 | ||
8497 | perf_event_init_all_cpus(); | |
8498 | init_srcu_struct(&pmus_srcu); | |
8499 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); | |
8500 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
8501 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
8502 | perf_tp_register(); | |
8503 | perf_cpu_notifier(perf_cpu_notify); | |
8504 | register_reboot_notifier(&perf_reboot_notifier); | |
8505 | ||
8506 | ret = init_hw_breakpoint(); | |
8507 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
8508 | ||
8509 | /* do not patch jump label more than once per second */ | |
8510 | jump_label_rate_limit(&perf_sched_events, HZ); | |
8511 | ||
8512 | /* | |
8513 | * Build time assertion that we keep the data_head at the intended | |
8514 | * location. IOW, validation we got the __reserved[] size right. | |
8515 | */ | |
8516 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
8517 | != 1024); | |
8518 | } | |
8519 | ||
8520 | static int __init perf_event_sysfs_init(void) | |
8521 | { | |
8522 | struct pmu *pmu; | |
8523 | int ret; | |
8524 | ||
8525 | mutex_lock(&pmus_lock); | |
8526 | ||
8527 | ret = bus_register(&pmu_bus); | |
8528 | if (ret) | |
8529 | goto unlock; | |
8530 | ||
8531 | list_for_each_entry(pmu, &pmus, entry) { | |
8532 | if (!pmu->name || pmu->type < 0) | |
8533 | continue; | |
8534 | ||
8535 | ret = pmu_dev_alloc(pmu); | |
8536 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
8537 | } | |
8538 | pmu_bus_running = 1; | |
8539 | ret = 0; | |
8540 | ||
8541 | unlock: | |
8542 | mutex_unlock(&pmus_lock); | |
8543 | ||
8544 | return ret; | |
8545 | } | |
8546 | device_initcall(perf_event_sysfs_init); | |
8547 | ||
8548 | #ifdef CONFIG_CGROUP_PERF | |
8549 | static struct cgroup_subsys_state * | |
8550 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
8551 | { | |
8552 | struct perf_cgroup *jc; | |
8553 | ||
8554 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); | |
8555 | if (!jc) | |
8556 | return ERR_PTR(-ENOMEM); | |
8557 | ||
8558 | jc->info = alloc_percpu(struct perf_cgroup_info); | |
8559 | if (!jc->info) { | |
8560 | kfree(jc); | |
8561 | return ERR_PTR(-ENOMEM); | |
8562 | } | |
8563 | ||
8564 | return &jc->css; | |
8565 | } | |
8566 | ||
8567 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) | |
8568 | { | |
8569 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); | |
8570 | ||
8571 | free_percpu(jc->info); | |
8572 | kfree(jc); | |
8573 | } | |
8574 | ||
8575 | static int __perf_cgroup_move(void *info) | |
8576 | { | |
8577 | struct task_struct *task = info; | |
8578 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); | |
8579 | return 0; | |
8580 | } | |
8581 | ||
8582 | static void perf_cgroup_attach(struct cgroup_subsys_state *css, | |
8583 | struct cgroup_taskset *tset) | |
8584 | { | |
8585 | struct task_struct *task; | |
8586 | ||
8587 | cgroup_taskset_for_each(task, tset) | |
8588 | task_function_call(task, __perf_cgroup_move, task); | |
8589 | } | |
8590 | ||
8591 | static void perf_cgroup_exit(struct cgroup_subsys_state *css, | |
8592 | struct cgroup_subsys_state *old_css, | |
8593 | struct task_struct *task) | |
8594 | { | |
8595 | /* | |
8596 | * cgroup_exit() is called in the copy_process() failure path. | |
8597 | * Ignore this case since the task hasn't ran yet, this avoids | |
8598 | * trying to poke a half freed task state from generic code. | |
8599 | */ | |
8600 | if (!(task->flags & PF_EXITING)) | |
8601 | return; | |
8602 | ||
8603 | task_function_call(task, __perf_cgroup_move, task); | |
8604 | } | |
8605 | ||
8606 | struct cgroup_subsys perf_event_cgrp_subsys = { | |
8607 | .css_alloc = perf_cgroup_css_alloc, | |
8608 | .css_free = perf_cgroup_css_free, | |
8609 | .exit = perf_cgroup_exit, | |
8610 | .attach = perf_cgroup_attach, | |
8611 | }; | |
8612 | #endif /* CONFIG_CGROUP_PERF */ |