2 * Performance events core code:
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
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
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/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
52 #include <asm/irq_regs.h>
54 typedef int (*remote_function_f)(void *);
56 struct remote_function_call {
57 struct task_struct *p;
58 remote_function_f func;
63 static void remote_function(void *data)
65 struct remote_function_call *tfc = data;
66 struct task_struct *p = tfc->p;
70 if (task_cpu(p) != smp_processor_id())
74 * Now that we're on right CPU with IRQs disabled, we can test
75 * if we hit the right task without races.
78 tfc->ret = -ESRCH; /* No such (running) process */
83 tfc->ret = tfc->func(tfc->info);
87 * task_function_call - call a function on the cpu on which a task runs
88 * @p: the task to evaluate
89 * @func: the function to be called
90 * @info: the function call argument
92 * Calls the function @func when the task is currently running. This might
93 * be on the current CPU, which just calls the function directly
95 * returns: @func return value, or
96 * -ESRCH - when the process isn't running
97 * -EAGAIN - when the process moved away
100 task_function_call(struct task_struct *p, remote_function_f func, void *info)
102 struct remote_function_call data = {
111 ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1);
114 } while (ret == -EAGAIN);
120 * cpu_function_call - call a function on the cpu
121 * @func: the function to be called
122 * @info: the function call argument
124 * Calls the function @func on the remote cpu.
126 * returns: @func return value or -ENXIO when the cpu is offline
128 static int cpu_function_call(int cpu, remote_function_f func, void *info)
130 struct remote_function_call data = {
134 .ret = -ENXIO, /* No such CPU */
137 smp_call_function_single(cpu, remote_function, &data, 1);
142 static inline struct perf_cpu_context *
143 __get_cpu_context(struct perf_event_context *ctx)
145 return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
148 static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
149 struct perf_event_context *ctx)
151 raw_spin_lock(&cpuctx->ctx.lock);
153 raw_spin_lock(&ctx->lock);
156 static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
157 struct perf_event_context *ctx)
160 raw_spin_unlock(&ctx->lock);
161 raw_spin_unlock(&cpuctx->ctx.lock);
164 #define TASK_TOMBSTONE ((void *)-1L)
166 static bool is_kernel_event(struct perf_event *event)
168 return READ_ONCE(event->owner) == TASK_TOMBSTONE;
172 * On task ctx scheduling...
174 * When !ctx->nr_events a task context will not be scheduled. This means
175 * we can disable the scheduler hooks (for performance) without leaving
176 * pending task ctx state.
178 * This however results in two special cases:
180 * - removing the last event from a task ctx; this is relatively straight
181 * forward and is done in __perf_remove_from_context.
183 * - adding the first event to a task ctx; this is tricky because we cannot
184 * rely on ctx->is_active and therefore cannot use event_function_call().
185 * See perf_install_in_context().
187 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
190 typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
191 struct perf_event_context *, void *);
193 struct event_function_struct {
194 struct perf_event *event;
199 static int event_function(void *info)
201 struct event_function_struct *efs = info;
202 struct perf_event *event = efs->event;
203 struct perf_event_context *ctx = event->ctx;
204 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
205 struct perf_event_context *task_ctx = cpuctx->task_ctx;
208 WARN_ON_ONCE(!irqs_disabled());
210 perf_ctx_lock(cpuctx, task_ctx);
212 * Since we do the IPI call without holding ctx->lock things can have
213 * changed, double check we hit the task we set out to hit.
216 if (ctx->task != current) {
222 * We only use event_function_call() on established contexts,
223 * and event_function() is only ever called when active (or
224 * rather, we'll have bailed in task_function_call() or the
225 * above ctx->task != current test), therefore we must have
226 * ctx->is_active here.
228 WARN_ON_ONCE(!ctx->is_active);
230 * And since we have ctx->is_active, cpuctx->task_ctx must
233 WARN_ON_ONCE(task_ctx != ctx);
235 WARN_ON_ONCE(&cpuctx->ctx != ctx);
238 efs->func(event, cpuctx, ctx, efs->data);
240 perf_ctx_unlock(cpuctx, task_ctx);
245 static void event_function_call(struct perf_event *event, event_f func, void *data)
247 struct perf_event_context *ctx = event->ctx;
248 struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
249 struct event_function_struct efs = {
255 if (!event->parent) {
257 * If this is a !child event, we must hold ctx::mutex to
258 * stabilize the the event->ctx relation. See
259 * perf_event_ctx_lock().
261 lockdep_assert_held(&ctx->mutex);
265 cpu_function_call(event->cpu, event_function, &efs);
269 if (task == TASK_TOMBSTONE)
273 if (!task_function_call(task, event_function, &efs))
276 raw_spin_lock_irq(&ctx->lock);
278 * Reload the task pointer, it might have been changed by
279 * a concurrent perf_event_context_sched_out().
282 if (task == TASK_TOMBSTONE) {
283 raw_spin_unlock_irq(&ctx->lock);
286 if (ctx->is_active) {
287 raw_spin_unlock_irq(&ctx->lock);
290 func(event, NULL, ctx, data);
291 raw_spin_unlock_irq(&ctx->lock);
295 * Similar to event_function_call() + event_function(), but hard assumes IRQs
296 * are already disabled and we're on the right CPU.
298 static void event_function_local(struct perf_event *event, event_f func, void *data)
300 struct perf_event_context *ctx = event->ctx;
301 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
302 struct task_struct *task = READ_ONCE(ctx->task);
303 struct perf_event_context *task_ctx = NULL;
305 WARN_ON_ONCE(!irqs_disabled());
308 if (task == TASK_TOMBSTONE)
314 perf_ctx_lock(cpuctx, task_ctx);
317 if (task == TASK_TOMBSTONE)
322 * We must be either inactive or active and the right task,
323 * otherwise we're screwed, since we cannot IPI to somewhere
326 if (ctx->is_active) {
327 if (WARN_ON_ONCE(task != current))
330 if (WARN_ON_ONCE(cpuctx->task_ctx != ctx))
334 WARN_ON_ONCE(&cpuctx->ctx != ctx);
337 func(event, cpuctx, ctx, data);
339 perf_ctx_unlock(cpuctx, task_ctx);
342 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
343 PERF_FLAG_FD_OUTPUT |\
344 PERF_FLAG_PID_CGROUP |\
345 PERF_FLAG_FD_CLOEXEC)
348 * branch priv levels that need permission checks
350 #define PERF_SAMPLE_BRANCH_PERM_PLM \
351 (PERF_SAMPLE_BRANCH_KERNEL |\
352 PERF_SAMPLE_BRANCH_HV)
355 EVENT_FLEXIBLE = 0x1,
358 EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
362 * perf_sched_events : >0 events exist
363 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
366 static void perf_sched_delayed(struct work_struct *work);
367 DEFINE_STATIC_KEY_FALSE(perf_sched_events);
368 static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
369 static DEFINE_MUTEX(perf_sched_mutex);
370 static atomic_t perf_sched_count;
372 static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
373 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
374 static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
376 static atomic_t nr_mmap_events __read_mostly;
377 static atomic_t nr_comm_events __read_mostly;
378 static atomic_t nr_task_events __read_mostly;
379 static atomic_t nr_freq_events __read_mostly;
380 static atomic_t nr_switch_events __read_mostly;
382 static LIST_HEAD(pmus);
383 static DEFINE_MUTEX(pmus_lock);
384 static struct srcu_struct pmus_srcu;
387 * perf event paranoia level:
388 * -1 - not paranoid at all
389 * 0 - disallow raw tracepoint access for unpriv
390 * 1 - disallow cpu events for unpriv
391 * 2 - disallow kernel profiling for unpriv
393 int sysctl_perf_event_paranoid __read_mostly = 2;
395 /* Minimum for 512 kiB + 1 user control page */
396 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
399 * max perf event sample rate
401 #define DEFAULT_MAX_SAMPLE_RATE 100000
402 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
403 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
405 int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
407 static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
408 static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
410 static int perf_sample_allowed_ns __read_mostly =
411 DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
413 static void update_perf_cpu_limits(void)
415 u64 tmp = perf_sample_period_ns;
417 tmp *= sysctl_perf_cpu_time_max_percent;
418 tmp = div_u64(tmp, 100);
422 WRITE_ONCE(perf_sample_allowed_ns, tmp);
425 static int perf_rotate_context(struct perf_cpu_context *cpuctx);
427 int perf_proc_update_handler(struct ctl_table *table, int write,
428 void __user *buffer, size_t *lenp,
431 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
437 * If throttling is disabled don't allow the write:
439 if (sysctl_perf_cpu_time_max_percent == 100 ||
440 sysctl_perf_cpu_time_max_percent == 0)
443 max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
444 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
445 update_perf_cpu_limits();
450 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
452 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
453 void __user *buffer, size_t *lenp,
456 int ret = proc_dointvec(table, write, buffer, lenp, ppos);
461 if (sysctl_perf_cpu_time_max_percent == 100 ||
462 sysctl_perf_cpu_time_max_percent == 0) {
464 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
465 WRITE_ONCE(perf_sample_allowed_ns, 0);
467 update_perf_cpu_limits();
474 * perf samples are done in some very critical code paths (NMIs).
475 * If they take too much CPU time, the system can lock up and not
476 * get any real work done. This will drop the sample rate when
477 * we detect that events are taking too long.
479 #define NR_ACCUMULATED_SAMPLES 128
480 static DEFINE_PER_CPU(u64, running_sample_length);
482 static u64 __report_avg;
483 static u64 __report_allowed;
485 static void perf_duration_warn(struct irq_work *w)
487 printk_ratelimited(KERN_INFO
488 "perf: interrupt took too long (%lld > %lld), lowering "
489 "kernel.perf_event_max_sample_rate to %d\n",
490 __report_avg, __report_allowed,
491 sysctl_perf_event_sample_rate);
494 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
496 void perf_sample_event_took(u64 sample_len_ns)
498 u64 max_len = READ_ONCE(perf_sample_allowed_ns);
506 /* Decay the counter by 1 average sample. */
507 running_len = __this_cpu_read(running_sample_length);
508 running_len -= running_len/NR_ACCUMULATED_SAMPLES;
509 running_len += sample_len_ns;
510 __this_cpu_write(running_sample_length, running_len);
513 * Note: this will be biased artifically low until we have
514 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
515 * from having to maintain a count.
517 avg_len = running_len/NR_ACCUMULATED_SAMPLES;
518 if (avg_len <= max_len)
521 __report_avg = avg_len;
522 __report_allowed = max_len;
525 * Compute a throttle threshold 25% below the current duration.
527 avg_len += avg_len / 4;
528 max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
534 WRITE_ONCE(perf_sample_allowed_ns, avg_len);
535 WRITE_ONCE(max_samples_per_tick, max);
537 sysctl_perf_event_sample_rate = max * HZ;
538 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
540 if (!irq_work_queue(&perf_duration_work)) {
541 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
542 "kernel.perf_event_max_sample_rate to %d\n",
543 __report_avg, __report_allowed,
544 sysctl_perf_event_sample_rate);
548 static atomic64_t perf_event_id;
550 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
551 enum event_type_t event_type);
553 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
554 enum event_type_t event_type,
555 struct task_struct *task);
557 static void update_context_time(struct perf_event_context *ctx);
558 static u64 perf_event_time(struct perf_event *event);
560 void __weak perf_event_print_debug(void) { }
562 extern __weak const char *perf_pmu_name(void)
567 static inline u64 perf_clock(void)
569 return local_clock();
572 static inline u64 perf_event_clock(struct perf_event *event)
574 return event->clock();
577 #ifdef CONFIG_CGROUP_PERF
580 perf_cgroup_match(struct perf_event *event)
582 struct perf_event_context *ctx = event->ctx;
583 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
585 /* @event doesn't care about cgroup */
589 /* wants specific cgroup scope but @cpuctx isn't associated with any */
594 * Cgroup scoping is recursive. An event enabled for a cgroup is
595 * also enabled for all its descendant cgroups. If @cpuctx's
596 * cgroup is a descendant of @event's (the test covers identity
597 * case), it's a match.
599 return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
600 event->cgrp->css.cgroup);
603 static inline void perf_detach_cgroup(struct perf_event *event)
605 css_put(&event->cgrp->css);
609 static inline int is_cgroup_event(struct perf_event *event)
611 return event->cgrp != NULL;
614 static inline u64 perf_cgroup_event_time(struct perf_event *event)
616 struct perf_cgroup_info *t;
618 t = per_cpu_ptr(event->cgrp->info, event->cpu);
622 static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
624 struct perf_cgroup_info *info;
629 info = this_cpu_ptr(cgrp->info);
631 info->time += now - info->timestamp;
632 info->timestamp = now;
635 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
637 struct perf_cgroup *cgrp_out = cpuctx->cgrp;
639 __update_cgrp_time(cgrp_out);
642 static inline void update_cgrp_time_from_event(struct perf_event *event)
644 struct perf_cgroup *cgrp;
647 * ensure we access cgroup data only when needed and
648 * when we know the cgroup is pinned (css_get)
650 if (!is_cgroup_event(event))
653 cgrp = perf_cgroup_from_task(current, event->ctx);
655 * Do not update time when cgroup is not active
657 if (cgrp == event->cgrp)
658 __update_cgrp_time(event->cgrp);
662 perf_cgroup_set_timestamp(struct task_struct *task,
663 struct perf_event_context *ctx)
665 struct perf_cgroup *cgrp;
666 struct perf_cgroup_info *info;
669 * ctx->lock held by caller
670 * ensure we do not access cgroup data
671 * unless we have the cgroup pinned (css_get)
673 if (!task || !ctx->nr_cgroups)
676 cgrp = perf_cgroup_from_task(task, ctx);
677 info = this_cpu_ptr(cgrp->info);
678 info->timestamp = ctx->timestamp;
681 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
682 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
685 * reschedule events based on the cgroup constraint of task.
687 * mode SWOUT : schedule out everything
688 * mode SWIN : schedule in based on cgroup for next
690 static void perf_cgroup_switch(struct task_struct *task, int mode)
692 struct perf_cpu_context *cpuctx;
697 * disable interrupts to avoid geting nr_cgroup
698 * changes via __perf_event_disable(). Also
701 local_irq_save(flags);
704 * we reschedule only in the presence of cgroup
705 * constrained events.
708 list_for_each_entry_rcu(pmu, &pmus, entry) {
709 cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
710 if (cpuctx->unique_pmu != pmu)
711 continue; /* ensure we process each cpuctx once */
714 * perf_cgroup_events says at least one
715 * context on this CPU has cgroup events.
717 * ctx->nr_cgroups reports the number of cgroup
718 * events for a context.
720 if (cpuctx->ctx.nr_cgroups > 0) {
721 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
722 perf_pmu_disable(cpuctx->ctx.pmu);
724 if (mode & PERF_CGROUP_SWOUT) {
725 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
727 * must not be done before ctxswout due
728 * to event_filter_match() in event_sched_out()
733 if (mode & PERF_CGROUP_SWIN) {
734 WARN_ON_ONCE(cpuctx->cgrp);
736 * set cgrp before ctxsw in to allow
737 * event_filter_match() to not have to pass
739 * we pass the cpuctx->ctx to perf_cgroup_from_task()
740 * because cgorup events are only per-cpu
742 cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
743 cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
745 perf_pmu_enable(cpuctx->ctx.pmu);
746 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
750 local_irq_restore(flags);
753 static inline void perf_cgroup_sched_out(struct task_struct *task,
754 struct task_struct *next)
756 struct perf_cgroup *cgrp1;
757 struct perf_cgroup *cgrp2 = NULL;
761 * we come here when we know perf_cgroup_events > 0
762 * we do not need to pass the ctx here because we know
763 * we are holding the rcu lock
765 cgrp1 = perf_cgroup_from_task(task, NULL);
766 cgrp2 = perf_cgroup_from_task(next, NULL);
769 * only schedule out current cgroup events if we know
770 * that we are switching to a different cgroup. Otherwise,
771 * do no touch the cgroup events.
774 perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
779 static inline void perf_cgroup_sched_in(struct task_struct *prev,
780 struct task_struct *task)
782 struct perf_cgroup *cgrp1;
783 struct perf_cgroup *cgrp2 = NULL;
787 * we come here when we know perf_cgroup_events > 0
788 * we do not need to pass the ctx here because we know
789 * we are holding the rcu lock
791 cgrp1 = perf_cgroup_from_task(task, NULL);
792 cgrp2 = perf_cgroup_from_task(prev, NULL);
795 * only need to schedule in cgroup events if we are changing
796 * cgroup during ctxsw. Cgroup events were not scheduled
797 * out of ctxsw out if that was not the case.
800 perf_cgroup_switch(task, PERF_CGROUP_SWIN);
805 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
806 struct perf_event_attr *attr,
807 struct perf_event *group_leader)
809 struct perf_cgroup *cgrp;
810 struct cgroup_subsys_state *css;
811 struct fd f = fdget(fd);
817 css = css_tryget_online_from_dir(f.file->f_path.dentry,
818 &perf_event_cgrp_subsys);
824 cgrp = container_of(css, struct perf_cgroup, css);
828 * all events in a group must monitor
829 * the same cgroup because a task belongs
830 * to only one perf cgroup at a time
832 if (group_leader && group_leader->cgrp != cgrp) {
833 perf_detach_cgroup(event);
842 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
844 struct perf_cgroup_info *t;
845 t = per_cpu_ptr(event->cgrp->info, event->cpu);
846 event->shadow_ctx_time = now - t->timestamp;
850 perf_cgroup_defer_enabled(struct perf_event *event)
853 * when the current task's perf cgroup does not match
854 * the event's, we need to remember to call the
855 * perf_mark_enable() function the first time a task with
856 * a matching perf cgroup is scheduled in.
858 if (is_cgroup_event(event) && !perf_cgroup_match(event))
859 event->cgrp_defer_enabled = 1;
863 perf_cgroup_mark_enabled(struct perf_event *event,
864 struct perf_event_context *ctx)
866 struct perf_event *sub;
867 u64 tstamp = perf_event_time(event);
869 if (!event->cgrp_defer_enabled)
872 event->cgrp_defer_enabled = 0;
874 event->tstamp_enabled = tstamp - event->total_time_enabled;
875 list_for_each_entry(sub, &event->sibling_list, group_entry) {
876 if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
877 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
878 sub->cgrp_defer_enabled = 0;
884 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
885 * cleared when last cgroup event is removed.
888 list_update_cgroup_event(struct perf_event *event,
889 struct perf_event_context *ctx, bool add)
891 struct perf_cpu_context *cpuctx;
893 if (!is_cgroup_event(event))
896 if (add && ctx->nr_cgroups++)
898 else if (!add && --ctx->nr_cgroups)
901 * Because cgroup events are always per-cpu events,
902 * this will always be called from the right CPU.
904 cpuctx = __get_cpu_context(ctx);
905 cpuctx->cgrp = add ? event->cgrp : NULL;
908 #else /* !CONFIG_CGROUP_PERF */
911 perf_cgroup_match(struct perf_event *event)
916 static inline void perf_detach_cgroup(struct perf_event *event)
919 static inline int is_cgroup_event(struct perf_event *event)
924 static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
929 static inline void update_cgrp_time_from_event(struct perf_event *event)
933 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
937 static inline void perf_cgroup_sched_out(struct task_struct *task,
938 struct task_struct *next)
942 static inline void perf_cgroup_sched_in(struct task_struct *prev,
943 struct task_struct *task)
947 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
948 struct perf_event_attr *attr,
949 struct perf_event *group_leader)
955 perf_cgroup_set_timestamp(struct task_struct *task,
956 struct perf_event_context *ctx)
961 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
966 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
970 static inline u64 perf_cgroup_event_time(struct perf_event *event)
976 perf_cgroup_defer_enabled(struct perf_event *event)
981 perf_cgroup_mark_enabled(struct perf_event *event,
982 struct perf_event_context *ctx)
987 list_update_cgroup_event(struct perf_event *event,
988 struct perf_event_context *ctx, bool add)
995 * set default to be dependent on timer tick just
998 #define PERF_CPU_HRTIMER (1000 / HZ)
1000 * function must be called with interrupts disbled
1002 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
1004 struct perf_cpu_context *cpuctx;
1007 WARN_ON(!irqs_disabled());
1009 cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
1010 rotations = perf_rotate_context(cpuctx);
1012 raw_spin_lock(&cpuctx->hrtimer_lock);
1014 hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
1016 cpuctx->hrtimer_active = 0;
1017 raw_spin_unlock(&cpuctx->hrtimer_lock);
1019 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
1022 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
1024 struct hrtimer *timer = &cpuctx->hrtimer;
1025 struct pmu *pmu = cpuctx->ctx.pmu;
1028 /* no multiplexing needed for SW PMU */
1029 if (pmu->task_ctx_nr == perf_sw_context)
1033 * check default is sane, if not set then force to
1034 * default interval (1/tick)
1036 interval = pmu->hrtimer_interval_ms;
1038 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
1040 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
1042 raw_spin_lock_init(&cpuctx->hrtimer_lock);
1043 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1044 timer->function = perf_mux_hrtimer_handler;
1047 static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
1049 struct hrtimer *timer = &cpuctx->hrtimer;
1050 struct pmu *pmu = cpuctx->ctx.pmu;
1051 unsigned long flags;
1053 /* not for SW PMU */
1054 if (pmu->task_ctx_nr == perf_sw_context)
1057 raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
1058 if (!cpuctx->hrtimer_active) {
1059 cpuctx->hrtimer_active = 1;
1060 hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
1061 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
1063 raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
1068 void perf_pmu_disable(struct pmu *pmu)
1070 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1072 pmu->pmu_disable(pmu);
1075 void perf_pmu_enable(struct pmu *pmu)
1077 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1079 pmu->pmu_enable(pmu);
1082 static DEFINE_PER_CPU(struct list_head, active_ctx_list);
1085 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1086 * perf_event_task_tick() are fully serialized because they're strictly cpu
1087 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1088 * disabled, while perf_event_task_tick is called from IRQ context.
1090 static void perf_event_ctx_activate(struct perf_event_context *ctx)
1092 struct list_head *head = this_cpu_ptr(&active_ctx_list);
1094 WARN_ON(!irqs_disabled());
1096 WARN_ON(!list_empty(&ctx->active_ctx_list));
1098 list_add(&ctx->active_ctx_list, head);
1101 static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
1103 WARN_ON(!irqs_disabled());
1105 WARN_ON(list_empty(&ctx->active_ctx_list));
1107 list_del_init(&ctx->active_ctx_list);
1110 static void get_ctx(struct perf_event_context *ctx)
1112 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
1115 static void free_ctx(struct rcu_head *head)
1117 struct perf_event_context *ctx;
1119 ctx = container_of(head, struct perf_event_context, rcu_head);
1120 kfree(ctx->task_ctx_data);
1124 static void put_ctx(struct perf_event_context *ctx)
1126 if (atomic_dec_and_test(&ctx->refcount)) {
1127 if (ctx->parent_ctx)
1128 put_ctx(ctx->parent_ctx);
1129 if (ctx->task && ctx->task != TASK_TOMBSTONE)
1130 put_task_struct(ctx->task);
1131 call_rcu(&ctx->rcu_head, free_ctx);
1136 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1137 * perf_pmu_migrate_context() we need some magic.
1139 * Those places that change perf_event::ctx will hold both
1140 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1142 * Lock ordering is by mutex address. There are two other sites where
1143 * perf_event_context::mutex nests and those are:
1145 * - perf_event_exit_task_context() [ child , 0 ]
1146 * perf_event_exit_event()
1147 * put_event() [ parent, 1 ]
1149 * - perf_event_init_context() [ parent, 0 ]
1150 * inherit_task_group()
1153 * perf_event_alloc()
1155 * perf_try_init_event() [ child , 1 ]
1157 * While it appears there is an obvious deadlock here -- the parent and child
1158 * nesting levels are inverted between the two. This is in fact safe because
1159 * life-time rules separate them. That is an exiting task cannot fork, and a
1160 * spawning task cannot (yet) exit.
1162 * But remember that that these are parent<->child context relations, and
1163 * migration does not affect children, therefore these two orderings should not
1166 * The change in perf_event::ctx does not affect children (as claimed above)
1167 * because the sys_perf_event_open() case will install a new event and break
1168 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1169 * concerned with cpuctx and that doesn't have children.
1171 * The places that change perf_event::ctx will issue:
1173 * perf_remove_from_context();
1174 * synchronize_rcu();
1175 * perf_install_in_context();
1177 * to affect the change. The remove_from_context() + synchronize_rcu() should
1178 * quiesce the event, after which we can install it in the new location. This
1179 * means that only external vectors (perf_fops, prctl) can perturb the event
1180 * while in transit. Therefore all such accessors should also acquire
1181 * perf_event_context::mutex to serialize against this.
1183 * However; because event->ctx can change while we're waiting to acquire
1184 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1189 * task_struct::perf_event_mutex
1190 * perf_event_context::mutex
1191 * perf_event::child_mutex;
1192 * perf_event_context::lock
1193 * perf_event::mmap_mutex
1196 static struct perf_event_context *
1197 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
1199 struct perf_event_context *ctx;
1203 ctx = ACCESS_ONCE(event->ctx);
1204 if (!atomic_inc_not_zero(&ctx->refcount)) {
1210 mutex_lock_nested(&ctx->mutex, nesting);
1211 if (event->ctx != ctx) {
1212 mutex_unlock(&ctx->mutex);
1220 static inline struct perf_event_context *
1221 perf_event_ctx_lock(struct perf_event *event)
1223 return perf_event_ctx_lock_nested(event, 0);
1226 static void perf_event_ctx_unlock(struct perf_event *event,
1227 struct perf_event_context *ctx)
1229 mutex_unlock(&ctx->mutex);
1234 * This must be done under the ctx->lock, such as to serialize against
1235 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1236 * calling scheduler related locks and ctx->lock nests inside those.
1238 static __must_check struct perf_event_context *
1239 unclone_ctx(struct perf_event_context *ctx)
1241 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1243 lockdep_assert_held(&ctx->lock);
1246 ctx->parent_ctx = NULL;
1252 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1255 * only top level events have the pid namespace they were created in
1258 event = event->parent;
1260 return task_tgid_nr_ns(p, event->ns);
1263 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1266 * only top level events have the pid namespace they were created in
1269 event = event->parent;
1271 return task_pid_nr_ns(p, event->ns);
1275 * If we inherit events we want to return the parent event id
1278 static u64 primary_event_id(struct perf_event *event)
1283 id = event->parent->id;
1289 * Get the perf_event_context for a task and lock it.
1291 * This has to cope with with the fact that until it is locked,
1292 * the context could get moved to another task.
1294 static struct perf_event_context *
1295 perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
1297 struct perf_event_context *ctx;
1301 * One of the few rules of preemptible RCU is that one cannot do
1302 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1303 * part of the read side critical section was irqs-enabled -- see
1304 * rcu_read_unlock_special().
1306 * Since ctx->lock nests under rq->lock we must ensure the entire read
1307 * side critical section has interrupts disabled.
1309 local_irq_save(*flags);
1311 ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
1314 * If this context is a clone of another, it might
1315 * get swapped for another underneath us by
1316 * perf_event_task_sched_out, though the
1317 * rcu_read_lock() protects us from any context
1318 * getting freed. Lock the context and check if it
1319 * got swapped before we could get the lock, and retry
1320 * if so. If we locked the right context, then it
1321 * can't get swapped on us any more.
1323 raw_spin_lock(&ctx->lock);
1324 if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
1325 raw_spin_unlock(&ctx->lock);
1327 local_irq_restore(*flags);
1331 if (ctx->task == TASK_TOMBSTONE ||
1332 !atomic_inc_not_zero(&ctx->refcount)) {
1333 raw_spin_unlock(&ctx->lock);
1336 WARN_ON_ONCE(ctx->task != task);
1341 local_irq_restore(*flags);
1346 * Get the context for a task and increment its pin_count so it
1347 * can't get swapped to another task. This also increments its
1348 * reference count so that the context can't get freed.
1350 static struct perf_event_context *
1351 perf_pin_task_context(struct task_struct *task, int ctxn)
1353 struct perf_event_context *ctx;
1354 unsigned long flags;
1356 ctx = perf_lock_task_context(task, ctxn, &flags);
1359 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1364 static void perf_unpin_context(struct perf_event_context *ctx)
1366 unsigned long flags;
1368 raw_spin_lock_irqsave(&ctx->lock, flags);
1370 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1374 * Update the record of the current time in a context.
1376 static void update_context_time(struct perf_event_context *ctx)
1378 u64 now = perf_clock();
1380 ctx->time += now - ctx->timestamp;
1381 ctx->timestamp = now;
1384 static u64 perf_event_time(struct perf_event *event)
1386 struct perf_event_context *ctx = event->ctx;
1388 if (is_cgroup_event(event))
1389 return perf_cgroup_event_time(event);
1391 return ctx ? ctx->time : 0;
1395 * Update the total_time_enabled and total_time_running fields for a event.
1397 static void update_event_times(struct perf_event *event)
1399 struct perf_event_context *ctx = event->ctx;
1402 lockdep_assert_held(&ctx->lock);
1404 if (event->state < PERF_EVENT_STATE_INACTIVE ||
1405 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
1409 * in cgroup mode, time_enabled represents
1410 * the time the event was enabled AND active
1411 * tasks were in the monitored cgroup. This is
1412 * independent of the activity of the context as
1413 * there may be a mix of cgroup and non-cgroup events.
1415 * That is why we treat cgroup events differently
1418 if (is_cgroup_event(event))
1419 run_end = perf_cgroup_event_time(event);
1420 else if (ctx->is_active)
1421 run_end = ctx->time;
1423 run_end = event->tstamp_stopped;
1425 event->total_time_enabled = run_end - event->tstamp_enabled;
1427 if (event->state == PERF_EVENT_STATE_INACTIVE)
1428 run_end = event->tstamp_stopped;
1430 run_end = perf_event_time(event);
1432 event->total_time_running = run_end - event->tstamp_running;
1437 * Update total_time_enabled and total_time_running for all events in a group.
1439 static void update_group_times(struct perf_event *leader)
1441 struct perf_event *event;
1443 update_event_times(leader);
1444 list_for_each_entry(event, &leader->sibling_list, group_entry)
1445 update_event_times(event);
1448 static struct list_head *
1449 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
1451 if (event->attr.pinned)
1452 return &ctx->pinned_groups;
1454 return &ctx->flexible_groups;
1458 * Add a event from the lists for its context.
1459 * Must be called with ctx->mutex and ctx->lock held.
1462 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1465 lockdep_assert_held(&ctx->lock);
1467 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1468 event->attach_state |= PERF_ATTACH_CONTEXT;
1471 * If we're a stand alone event or group leader, we go to the context
1472 * list, group events are kept attached to the group so that
1473 * perf_group_detach can, at all times, locate all siblings.
1475 if (event->group_leader == event) {
1476 struct list_head *list;
1478 if (is_software_event(event))
1479 event->group_flags |= PERF_GROUP_SOFTWARE;
1481 list = ctx_group_list(event, ctx);
1482 list_add_tail(&event->group_entry, list);
1485 list_update_cgroup_event(event, ctx, true);
1487 list_add_rcu(&event->event_entry, &ctx->event_list);
1489 if (event->attr.inherit_stat)
1496 * Initialize event state based on the perf_event_attr::disabled.
1498 static inline void perf_event__state_init(struct perf_event *event)
1500 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1501 PERF_EVENT_STATE_INACTIVE;
1504 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1506 int entry = sizeof(u64); /* value */
1510 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1511 size += sizeof(u64);
1513 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1514 size += sizeof(u64);
1516 if (event->attr.read_format & PERF_FORMAT_ID)
1517 entry += sizeof(u64);
1519 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1521 size += sizeof(u64);
1525 event->read_size = size;
1528 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1530 struct perf_sample_data *data;
1533 if (sample_type & PERF_SAMPLE_IP)
1534 size += sizeof(data->ip);
1536 if (sample_type & PERF_SAMPLE_ADDR)
1537 size += sizeof(data->addr);
1539 if (sample_type & PERF_SAMPLE_PERIOD)
1540 size += sizeof(data->period);
1542 if (sample_type & PERF_SAMPLE_WEIGHT)
1543 size += sizeof(data->weight);
1545 if (sample_type & PERF_SAMPLE_READ)
1546 size += event->read_size;
1548 if (sample_type & PERF_SAMPLE_DATA_SRC)
1549 size += sizeof(data->data_src.val);
1551 if (sample_type & PERF_SAMPLE_TRANSACTION)
1552 size += sizeof(data->txn);
1554 event->header_size = size;
1558 * Called at perf_event creation and when events are attached/detached from a
1561 static void perf_event__header_size(struct perf_event *event)
1563 __perf_event_read_size(event,
1564 event->group_leader->nr_siblings);
1565 __perf_event_header_size(event, event->attr.sample_type);
1568 static void perf_event__id_header_size(struct perf_event *event)
1570 struct perf_sample_data *data;
1571 u64 sample_type = event->attr.sample_type;
1574 if (sample_type & PERF_SAMPLE_TID)
1575 size += sizeof(data->tid_entry);
1577 if (sample_type & PERF_SAMPLE_TIME)
1578 size += sizeof(data->time);
1580 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1581 size += sizeof(data->id);
1583 if (sample_type & PERF_SAMPLE_ID)
1584 size += sizeof(data->id);
1586 if (sample_type & PERF_SAMPLE_STREAM_ID)
1587 size += sizeof(data->stream_id);
1589 if (sample_type & PERF_SAMPLE_CPU)
1590 size += sizeof(data->cpu_entry);
1592 event->id_header_size = size;
1595 static bool perf_event_validate_size(struct perf_event *event)
1598 * The values computed here will be over-written when we actually
1601 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1602 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1603 perf_event__id_header_size(event);
1606 * Sum the lot; should not exceed the 64k limit we have on records.
1607 * Conservative limit to allow for callchains and other variable fields.
1609 if (event->read_size + event->header_size +
1610 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1616 static void perf_group_attach(struct perf_event *event)
1618 struct perf_event *group_leader = event->group_leader, *pos;
1621 * We can have double attach due to group movement in perf_event_open.
1623 if (event->attach_state & PERF_ATTACH_GROUP)
1626 event->attach_state |= PERF_ATTACH_GROUP;
1628 if (group_leader == event)
1631 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1633 if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
1634 !is_software_event(event))
1635 group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
1637 list_add_tail(&event->group_entry, &group_leader->sibling_list);
1638 group_leader->nr_siblings++;
1640 perf_event__header_size(group_leader);
1642 list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
1643 perf_event__header_size(pos);
1647 * Remove a event from the lists for its context.
1648 * Must be called with ctx->mutex and ctx->lock held.
1651 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1653 WARN_ON_ONCE(event->ctx != ctx);
1654 lockdep_assert_held(&ctx->lock);
1657 * We can have double detach due to exit/hot-unplug + close.
1659 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1662 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1664 list_update_cgroup_event(event, ctx, false);
1667 if (event->attr.inherit_stat)
1670 list_del_rcu(&event->event_entry);
1672 if (event->group_leader == event)
1673 list_del_init(&event->group_entry);
1675 update_group_times(event);
1678 * If event was in error state, then keep it
1679 * that way, otherwise bogus counts will be
1680 * returned on read(). The only way to get out
1681 * of error state is by explicit re-enabling
1684 if (event->state > PERF_EVENT_STATE_OFF)
1685 event->state = PERF_EVENT_STATE_OFF;
1690 static void perf_group_detach(struct perf_event *event)
1692 struct perf_event *sibling, *tmp;
1693 struct list_head *list = NULL;
1696 * We can have double detach due to exit/hot-unplug + close.
1698 if (!(event->attach_state & PERF_ATTACH_GROUP))
1701 event->attach_state &= ~PERF_ATTACH_GROUP;
1704 * If this is a sibling, remove it from its group.
1706 if (event->group_leader != event) {
1707 list_del_init(&event->group_entry);
1708 event->group_leader->nr_siblings--;
1712 if (!list_empty(&event->group_entry))
1713 list = &event->group_entry;
1716 * If this was a group event with sibling events then
1717 * upgrade the siblings to singleton events by adding them
1718 * to whatever list we are on.
1720 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
1722 list_move_tail(&sibling->group_entry, list);
1723 sibling->group_leader = sibling;
1725 /* Inherit group flags from the previous leader */
1726 sibling->group_flags = event->group_flags;
1728 WARN_ON_ONCE(sibling->ctx != event->ctx);
1732 perf_event__header_size(event->group_leader);
1734 list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
1735 perf_event__header_size(tmp);
1738 static bool is_orphaned_event(struct perf_event *event)
1740 return event->state == PERF_EVENT_STATE_DEAD;
1743 static inline int __pmu_filter_match(struct perf_event *event)
1745 struct pmu *pmu = event->pmu;
1746 return pmu->filter_match ? pmu->filter_match(event) : 1;
1750 * Check whether we should attempt to schedule an event group based on
1751 * PMU-specific filtering. An event group can consist of HW and SW events,
1752 * potentially with a SW leader, so we must check all the filters, to
1753 * determine whether a group is schedulable:
1755 static inline int pmu_filter_match(struct perf_event *event)
1757 struct perf_event *child;
1759 if (!__pmu_filter_match(event))
1762 list_for_each_entry(child, &event->sibling_list, group_entry) {
1763 if (!__pmu_filter_match(child))
1771 event_filter_match(struct perf_event *event)
1773 return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
1774 perf_cgroup_match(event) && pmu_filter_match(event);
1778 event_sched_out(struct perf_event *event,
1779 struct perf_cpu_context *cpuctx,
1780 struct perf_event_context *ctx)
1782 u64 tstamp = perf_event_time(event);
1785 WARN_ON_ONCE(event->ctx != ctx);
1786 lockdep_assert_held(&ctx->lock);
1789 * An event which could not be activated because of
1790 * filter mismatch still needs to have its timings
1791 * maintained, otherwise bogus information is return
1792 * via read() for time_enabled, time_running:
1794 if (event->state == PERF_EVENT_STATE_INACTIVE &&
1795 !event_filter_match(event)) {
1796 delta = tstamp - event->tstamp_stopped;
1797 event->tstamp_running += delta;
1798 event->tstamp_stopped = tstamp;
1801 if (event->state != PERF_EVENT_STATE_ACTIVE)
1804 perf_pmu_disable(event->pmu);
1806 event->tstamp_stopped = tstamp;
1807 event->pmu->del(event, 0);
1809 event->state = PERF_EVENT_STATE_INACTIVE;
1810 if (event->pending_disable) {
1811 event->pending_disable = 0;
1812 event->state = PERF_EVENT_STATE_OFF;
1815 if (!is_software_event(event))
1816 cpuctx->active_oncpu--;
1817 if (!--ctx->nr_active)
1818 perf_event_ctx_deactivate(ctx);
1819 if (event->attr.freq && event->attr.sample_freq)
1821 if (event->attr.exclusive || !cpuctx->active_oncpu)
1822 cpuctx->exclusive = 0;
1824 perf_pmu_enable(event->pmu);
1828 group_sched_out(struct perf_event *group_event,
1829 struct perf_cpu_context *cpuctx,
1830 struct perf_event_context *ctx)
1832 struct perf_event *event;
1833 int state = group_event->state;
1835 event_sched_out(group_event, cpuctx, ctx);
1838 * Schedule out siblings (if any):
1840 list_for_each_entry(event, &group_event->sibling_list, group_entry)
1841 event_sched_out(event, cpuctx, ctx);
1843 if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
1844 cpuctx->exclusive = 0;
1847 #define DETACH_GROUP 0x01UL
1850 * Cross CPU call to remove a performance event
1852 * We disable the event on the hardware level first. After that we
1853 * remove it from the context list.
1856 __perf_remove_from_context(struct perf_event *event,
1857 struct perf_cpu_context *cpuctx,
1858 struct perf_event_context *ctx,
1861 unsigned long flags = (unsigned long)info;
1863 event_sched_out(event, cpuctx, ctx);
1864 if (flags & DETACH_GROUP)
1865 perf_group_detach(event);
1866 list_del_event(event, ctx);
1868 if (!ctx->nr_events && ctx->is_active) {
1871 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
1872 cpuctx->task_ctx = NULL;
1878 * Remove the event from a task's (or a CPU's) list of events.
1880 * If event->ctx is a cloned context, callers must make sure that
1881 * every task struct that event->ctx->task could possibly point to
1882 * remains valid. This is OK when called from perf_release since
1883 * that only calls us on the top-level context, which can't be a clone.
1884 * When called from perf_event_exit_task, it's OK because the
1885 * context has been detached from its task.
1887 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
1889 lockdep_assert_held(&event->ctx->mutex);
1891 event_function_call(event, __perf_remove_from_context, (void *)flags);
1895 * Cross CPU call to disable a performance event
1897 static void __perf_event_disable(struct perf_event *event,
1898 struct perf_cpu_context *cpuctx,
1899 struct perf_event_context *ctx,
1902 if (event->state < PERF_EVENT_STATE_INACTIVE)
1905 update_context_time(ctx);
1906 update_cgrp_time_from_event(event);
1907 update_group_times(event);
1908 if (event == event->group_leader)
1909 group_sched_out(event, cpuctx, ctx);
1911 event_sched_out(event, cpuctx, ctx);
1912 event->state = PERF_EVENT_STATE_OFF;
1918 * If event->ctx is a cloned context, callers must make sure that
1919 * every task struct that event->ctx->task could possibly point to
1920 * remains valid. This condition is satisifed when called through
1921 * perf_event_for_each_child or perf_event_for_each because they
1922 * hold the top-level event's child_mutex, so any descendant that
1923 * goes to exit will block in perf_event_exit_event().
1925 * When called from perf_pending_event it's OK because event->ctx
1926 * is the current context on this CPU and preemption is disabled,
1927 * hence we can't get into perf_event_task_sched_out for this context.
1929 static void _perf_event_disable(struct perf_event *event)
1931 struct perf_event_context *ctx = event->ctx;
1933 raw_spin_lock_irq(&ctx->lock);
1934 if (event->state <= PERF_EVENT_STATE_OFF) {
1935 raw_spin_unlock_irq(&ctx->lock);
1938 raw_spin_unlock_irq(&ctx->lock);
1940 event_function_call(event, __perf_event_disable, NULL);
1943 void perf_event_disable_local(struct perf_event *event)
1945 event_function_local(event, __perf_event_disable, NULL);
1949 * Strictly speaking kernel users cannot create groups and therefore this
1950 * interface does not need the perf_event_ctx_lock() magic.
1952 void perf_event_disable(struct perf_event *event)
1954 struct perf_event_context *ctx;
1956 ctx = perf_event_ctx_lock(event);
1957 _perf_event_disable(event);
1958 perf_event_ctx_unlock(event, ctx);
1960 EXPORT_SYMBOL_GPL(perf_event_disable);
1962 static void perf_set_shadow_time(struct perf_event *event,
1963 struct perf_event_context *ctx,
1967 * use the correct time source for the time snapshot
1969 * We could get by without this by leveraging the
1970 * fact that to get to this function, the caller
1971 * has most likely already called update_context_time()
1972 * and update_cgrp_time_xx() and thus both timestamp
1973 * are identical (or very close). Given that tstamp is,
1974 * already adjusted for cgroup, we could say that:
1975 * tstamp - ctx->timestamp
1977 * tstamp - cgrp->timestamp.
1979 * Then, in perf_output_read(), the calculation would
1980 * work with no changes because:
1981 * - event is guaranteed scheduled in
1982 * - no scheduled out in between
1983 * - thus the timestamp would be the same
1985 * But this is a bit hairy.
1987 * So instead, we have an explicit cgroup call to remain
1988 * within the time time source all along. We believe it
1989 * is cleaner and simpler to understand.
1991 if (is_cgroup_event(event))
1992 perf_cgroup_set_shadow_time(event, tstamp);
1994 event->shadow_ctx_time = tstamp - ctx->timestamp;
1997 #define MAX_INTERRUPTS (~0ULL)
1999 static void perf_log_throttle(struct perf_event *event, int enable);
2000 static void perf_log_itrace_start(struct perf_event *event);
2003 event_sched_in(struct perf_event *event,
2004 struct perf_cpu_context *cpuctx,
2005 struct perf_event_context *ctx)
2007 u64 tstamp = perf_event_time(event);
2010 lockdep_assert_held(&ctx->lock);
2012 if (event->state <= PERF_EVENT_STATE_OFF)
2015 WRITE_ONCE(event->oncpu, smp_processor_id());
2017 * Order event::oncpu write to happen before the ACTIVE state
2021 WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE);
2024 * Unthrottle events, since we scheduled we might have missed several
2025 * ticks already, also for a heavily scheduling task there is little
2026 * guarantee it'll get a tick in a timely manner.
2028 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
2029 perf_log_throttle(event, 1);
2030 event->hw.interrupts = 0;
2034 * The new state must be visible before we turn it on in the hardware:
2038 perf_pmu_disable(event->pmu);
2040 perf_set_shadow_time(event, ctx, tstamp);
2042 perf_log_itrace_start(event);
2044 if (event->pmu->add(event, PERF_EF_START)) {
2045 event->state = PERF_EVENT_STATE_INACTIVE;
2051 event->tstamp_running += tstamp - event->tstamp_stopped;
2053 if (!is_software_event(event))
2054 cpuctx->active_oncpu++;
2055 if (!ctx->nr_active++)
2056 perf_event_ctx_activate(ctx);
2057 if (event->attr.freq && event->attr.sample_freq)
2060 if (event->attr.exclusive)
2061 cpuctx->exclusive = 1;
2064 perf_pmu_enable(event->pmu);
2070 group_sched_in(struct perf_event *group_event,
2071 struct perf_cpu_context *cpuctx,
2072 struct perf_event_context *ctx)
2074 struct perf_event *event, *partial_group = NULL;
2075 struct pmu *pmu = ctx->pmu;
2076 u64 now = ctx->time;
2077 bool simulate = false;
2079 if (group_event->state == PERF_EVENT_STATE_OFF)
2082 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
2084 if (event_sched_in(group_event, cpuctx, ctx)) {
2085 pmu->cancel_txn(pmu);
2086 perf_mux_hrtimer_restart(cpuctx);
2091 * Schedule in siblings as one group (if any):
2093 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2094 if (event_sched_in(event, cpuctx, ctx)) {
2095 partial_group = event;
2100 if (!pmu->commit_txn(pmu))
2105 * Groups can be scheduled in as one unit only, so undo any
2106 * partial group before returning:
2107 * The events up to the failed event are scheduled out normally,
2108 * tstamp_stopped will be updated.
2110 * The failed events and the remaining siblings need to have
2111 * their timings updated as if they had gone thru event_sched_in()
2112 * and event_sched_out(). This is required to get consistent timings
2113 * across the group. This also takes care of the case where the group
2114 * could never be scheduled by ensuring tstamp_stopped is set to mark
2115 * the time the event was actually stopped, such that time delta
2116 * calculation in update_event_times() is correct.
2118 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2119 if (event == partial_group)
2123 event->tstamp_running += now - event->tstamp_stopped;
2124 event->tstamp_stopped = now;
2126 event_sched_out(event, cpuctx, ctx);
2129 event_sched_out(group_event, cpuctx, ctx);
2131 pmu->cancel_txn(pmu);
2133 perf_mux_hrtimer_restart(cpuctx);
2139 * Work out whether we can put this event group on the CPU now.
2141 static int group_can_go_on(struct perf_event *event,
2142 struct perf_cpu_context *cpuctx,
2146 * Groups consisting entirely of software events can always go on.
2148 if (event->group_flags & PERF_GROUP_SOFTWARE)
2151 * If an exclusive group is already on, no other hardware
2154 if (cpuctx->exclusive)
2157 * If this group is exclusive and there are already
2158 * events on the CPU, it can't go on.
2160 if (event->attr.exclusive && cpuctx->active_oncpu)
2163 * Otherwise, try to add it if all previous groups were able
2169 static void add_event_to_ctx(struct perf_event *event,
2170 struct perf_event_context *ctx)
2172 u64 tstamp = perf_event_time(event);
2174 list_add_event(event, ctx);
2175 perf_group_attach(event);
2176 event->tstamp_enabled = tstamp;
2177 event->tstamp_running = tstamp;
2178 event->tstamp_stopped = tstamp;
2181 static void ctx_sched_out(struct perf_event_context *ctx,
2182 struct perf_cpu_context *cpuctx,
2183 enum event_type_t event_type);
2185 ctx_sched_in(struct perf_event_context *ctx,
2186 struct perf_cpu_context *cpuctx,
2187 enum event_type_t event_type,
2188 struct task_struct *task);
2190 static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
2191 struct perf_event_context *ctx)
2193 if (!cpuctx->task_ctx)
2196 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2199 ctx_sched_out(ctx, cpuctx, EVENT_ALL);
2202 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2203 struct perf_event_context *ctx,
2204 struct task_struct *task)
2206 cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
2208 ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
2209 cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
2211 ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
2214 static void ctx_resched(struct perf_cpu_context *cpuctx,
2215 struct perf_event_context *task_ctx)
2217 perf_pmu_disable(cpuctx->ctx.pmu);
2219 task_ctx_sched_out(cpuctx, task_ctx);
2220 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
2221 perf_event_sched_in(cpuctx, task_ctx, current);
2222 perf_pmu_enable(cpuctx->ctx.pmu);
2226 * Cross CPU call to install and enable a performance event
2228 * Very similar to remote_function() + event_function() but cannot assume that
2229 * things like ctx->is_active and cpuctx->task_ctx are set.
2231 static int __perf_install_in_context(void *info)
2233 struct perf_event *event = info;
2234 struct perf_event_context *ctx = event->ctx;
2235 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2236 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2237 bool activate = true;
2240 raw_spin_lock(&cpuctx->ctx.lock);
2242 raw_spin_lock(&ctx->lock);
2245 /* If we're on the wrong CPU, try again */
2246 if (task_cpu(ctx->task) != smp_processor_id()) {
2252 * If we're on the right CPU, see if the task we target is
2253 * current, if not we don't have to activate the ctx, a future
2254 * context switch will do that for us.
2256 if (ctx->task != current)
2259 WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2261 } else if (task_ctx) {
2262 raw_spin_lock(&task_ctx->lock);
2266 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2267 add_event_to_ctx(event, ctx);
2268 ctx_resched(cpuctx, task_ctx);
2270 add_event_to_ctx(event, ctx);
2274 perf_ctx_unlock(cpuctx, task_ctx);
2280 * Attach a performance event to a context.
2282 * Very similar to event_function_call, see comment there.
2285 perf_install_in_context(struct perf_event_context *ctx,
2286 struct perf_event *event,
2289 struct task_struct *task = READ_ONCE(ctx->task);
2291 lockdep_assert_held(&ctx->mutex);
2293 if (event->cpu != -1)
2297 * Ensures that if we can observe event->ctx, both the event and ctx
2298 * will be 'complete'. See perf_iterate_sb_cpu().
2300 smp_store_release(&event->ctx, ctx);
2303 cpu_function_call(cpu, __perf_install_in_context, event);
2308 * Should not happen, we validate the ctx is still alive before calling.
2310 if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
2314 * Installing events is tricky because we cannot rely on ctx->is_active
2315 * to be set in case this is the nr_events 0 -> 1 transition.
2319 * Cannot use task_function_call() because we need to run on the task's
2320 * CPU regardless of whether its current or not.
2322 if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event))
2325 raw_spin_lock_irq(&ctx->lock);
2327 if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
2329 * Cannot happen because we already checked above (which also
2330 * cannot happen), and we hold ctx->mutex, which serializes us
2331 * against perf_event_exit_task_context().
2333 raw_spin_unlock_irq(&ctx->lock);
2336 raw_spin_unlock_irq(&ctx->lock);
2338 * Since !ctx->is_active doesn't mean anything, we must IPI
2345 * Put a event into inactive state and update time fields.
2346 * Enabling the leader of a group effectively enables all
2347 * the group members that aren't explicitly disabled, so we
2348 * have to update their ->tstamp_enabled also.
2349 * Note: this works for group members as well as group leaders
2350 * since the non-leader members' sibling_lists will be empty.
2352 static void __perf_event_mark_enabled(struct perf_event *event)
2354 struct perf_event *sub;
2355 u64 tstamp = perf_event_time(event);
2357 event->state = PERF_EVENT_STATE_INACTIVE;
2358 event->tstamp_enabled = tstamp - event->total_time_enabled;
2359 list_for_each_entry(sub, &event->sibling_list, group_entry) {
2360 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
2361 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
2366 * Cross CPU call to enable a performance event
2368 static void __perf_event_enable(struct perf_event *event,
2369 struct perf_cpu_context *cpuctx,
2370 struct perf_event_context *ctx,
2373 struct perf_event *leader = event->group_leader;
2374 struct perf_event_context *task_ctx;
2376 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2377 event->state <= PERF_EVENT_STATE_ERROR)
2381 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2383 __perf_event_mark_enabled(event);
2385 if (!ctx->is_active)
2388 if (!event_filter_match(event)) {
2389 if (is_cgroup_event(event))
2390 perf_cgroup_defer_enabled(event);
2391 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2396 * If the event is in a group and isn't the group leader,
2397 * then don't put it on unless the group is on.
2399 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
2400 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2404 task_ctx = cpuctx->task_ctx;
2406 WARN_ON_ONCE(task_ctx != ctx);
2408 ctx_resched(cpuctx, task_ctx);
2414 * If event->ctx is a cloned context, callers must make sure that
2415 * every task struct that event->ctx->task could possibly point to
2416 * remains valid. This condition is satisfied when called through
2417 * perf_event_for_each_child or perf_event_for_each as described
2418 * for perf_event_disable.
2420 static void _perf_event_enable(struct perf_event *event)
2422 struct perf_event_context *ctx = event->ctx;
2424 raw_spin_lock_irq(&ctx->lock);
2425 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2426 event->state < PERF_EVENT_STATE_ERROR) {
2427 raw_spin_unlock_irq(&ctx->lock);
2432 * If the event is in error state, clear that first.
2434 * That way, if we see the event in error state below, we know that it
2435 * has gone back into error state, as distinct from the task having
2436 * been scheduled away before the cross-call arrived.
2438 if (event->state == PERF_EVENT_STATE_ERROR)
2439 event->state = PERF_EVENT_STATE_OFF;
2440 raw_spin_unlock_irq(&ctx->lock);
2442 event_function_call(event, __perf_event_enable, NULL);
2446 * See perf_event_disable();
2448 void perf_event_enable(struct perf_event *event)
2450 struct perf_event_context *ctx;
2452 ctx = perf_event_ctx_lock(event);
2453 _perf_event_enable(event);
2454 perf_event_ctx_unlock(event, ctx);
2456 EXPORT_SYMBOL_GPL(perf_event_enable);
2458 struct stop_event_data {
2459 struct perf_event *event;
2460 unsigned int restart;
2463 static int __perf_event_stop(void *info)
2465 struct stop_event_data *sd = info;
2466 struct perf_event *event = sd->event;
2468 /* if it's already INACTIVE, do nothing */
2469 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2472 /* matches smp_wmb() in event_sched_in() */
2476 * There is a window with interrupts enabled before we get here,
2477 * so we need to check again lest we try to stop another CPU's event.
2479 if (READ_ONCE(event->oncpu) != smp_processor_id())
2482 event->pmu->stop(event, PERF_EF_UPDATE);
2485 * May race with the actual stop (through perf_pmu_output_stop()),
2486 * but it is only used for events with AUX ring buffer, and such
2487 * events will refuse to restart because of rb::aux_mmap_count==0,
2488 * see comments in perf_aux_output_begin().
2490 * Since this is happening on a event-local CPU, no trace is lost
2494 event->pmu->start(event, PERF_EF_START);
2499 static int perf_event_restart(struct perf_event *event)
2501 struct stop_event_data sd = {
2508 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2511 /* matches smp_wmb() in event_sched_in() */
2515 * We only want to restart ACTIVE events, so if the event goes
2516 * inactive here (event->oncpu==-1), there's nothing more to do;
2517 * fall through with ret==-ENXIO.
2519 ret = cpu_function_call(READ_ONCE(event->oncpu),
2520 __perf_event_stop, &sd);
2521 } while (ret == -EAGAIN);
2527 * In order to contain the amount of racy and tricky in the address filter
2528 * configuration management, it is a two part process:
2530 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2531 * we update the addresses of corresponding vmas in
2532 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2533 * (p2) when an event is scheduled in (pmu::add), it calls
2534 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2535 * if the generation has changed since the previous call.
2537 * If (p1) happens while the event is active, we restart it to force (p2).
2539 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2540 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2542 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2543 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2545 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2548 void perf_event_addr_filters_sync(struct perf_event *event)
2550 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
2552 if (!has_addr_filter(event))
2555 raw_spin_lock(&ifh->lock);
2556 if (event->addr_filters_gen != event->hw.addr_filters_gen) {
2557 event->pmu->addr_filters_sync(event);
2558 event->hw.addr_filters_gen = event->addr_filters_gen;
2560 raw_spin_unlock(&ifh->lock);
2562 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
2564 static int _perf_event_refresh(struct perf_event *event, int refresh)
2567 * not supported on inherited events
2569 if (event->attr.inherit || !is_sampling_event(event))
2572 atomic_add(refresh, &event->event_limit);
2573 _perf_event_enable(event);
2579 * See perf_event_disable()
2581 int perf_event_refresh(struct perf_event *event, int refresh)
2583 struct perf_event_context *ctx;
2586 ctx = perf_event_ctx_lock(event);
2587 ret = _perf_event_refresh(event, refresh);
2588 perf_event_ctx_unlock(event, ctx);
2592 EXPORT_SYMBOL_GPL(perf_event_refresh);
2594 static void ctx_sched_out(struct perf_event_context *ctx,
2595 struct perf_cpu_context *cpuctx,
2596 enum event_type_t event_type)
2598 int is_active = ctx->is_active;
2599 struct perf_event *event;
2601 lockdep_assert_held(&ctx->lock);
2603 if (likely(!ctx->nr_events)) {
2605 * See __perf_remove_from_context().
2607 WARN_ON_ONCE(ctx->is_active);
2609 WARN_ON_ONCE(cpuctx->task_ctx);
2613 ctx->is_active &= ~event_type;
2614 if (!(ctx->is_active & EVENT_ALL))
2618 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
2619 if (!ctx->is_active)
2620 cpuctx->task_ctx = NULL;
2624 * Always update time if it was set; not only when it changes.
2625 * Otherwise we can 'forget' to update time for any but the last
2626 * context we sched out. For example:
2628 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2629 * ctx_sched_out(.event_type = EVENT_PINNED)
2631 * would only update time for the pinned events.
2633 if (is_active & EVENT_TIME) {
2634 /* update (and stop) ctx time */
2635 update_context_time(ctx);
2636 update_cgrp_time_from_cpuctx(cpuctx);
2639 is_active ^= ctx->is_active; /* changed bits */
2641 if (!ctx->nr_active || !(is_active & EVENT_ALL))
2644 perf_pmu_disable(ctx->pmu);
2645 if (is_active & EVENT_PINNED) {
2646 list_for_each_entry(event, &ctx->pinned_groups, group_entry)
2647 group_sched_out(event, cpuctx, ctx);
2650 if (is_active & EVENT_FLEXIBLE) {
2651 list_for_each_entry(event, &ctx->flexible_groups, group_entry)
2652 group_sched_out(event, cpuctx, ctx);
2654 perf_pmu_enable(ctx->pmu);
2658 * Test whether two contexts are equivalent, i.e. whether they have both been
2659 * cloned from the same version of the same context.
2661 * Equivalence is measured using a generation number in the context that is
2662 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2663 * and list_del_event().
2665 static int context_equiv(struct perf_event_context *ctx1,
2666 struct perf_event_context *ctx2)
2668 lockdep_assert_held(&ctx1->lock);
2669 lockdep_assert_held(&ctx2->lock);
2671 /* Pinning disables the swap optimization */
2672 if (ctx1->pin_count || ctx2->pin_count)
2675 /* If ctx1 is the parent of ctx2 */
2676 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
2679 /* If ctx2 is the parent of ctx1 */
2680 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
2684 * If ctx1 and ctx2 have the same parent; we flatten the parent
2685 * hierarchy, see perf_event_init_context().
2687 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
2688 ctx1->parent_gen == ctx2->parent_gen)
2695 static void __perf_event_sync_stat(struct perf_event *event,
2696 struct perf_event *next_event)
2700 if (!event->attr.inherit_stat)
2704 * Update the event value, we cannot use perf_event_read()
2705 * because we're in the middle of a context switch and have IRQs
2706 * disabled, which upsets smp_call_function_single(), however
2707 * we know the event must be on the current CPU, therefore we
2708 * don't need to use it.
2710 switch (event->state) {
2711 case PERF_EVENT_STATE_ACTIVE:
2712 event->pmu->read(event);
2715 case PERF_EVENT_STATE_INACTIVE:
2716 update_event_times(event);
2724 * In order to keep per-task stats reliable we need to flip the event
2725 * values when we flip the contexts.
2727 value = local64_read(&next_event->count);
2728 value = local64_xchg(&event->count, value);
2729 local64_set(&next_event->count, value);
2731 swap(event->total_time_enabled, next_event->total_time_enabled);
2732 swap(event->total_time_running, next_event->total_time_running);
2735 * Since we swizzled the values, update the user visible data too.
2737 perf_event_update_userpage(event);
2738 perf_event_update_userpage(next_event);
2741 static void perf_event_sync_stat(struct perf_event_context *ctx,
2742 struct perf_event_context *next_ctx)
2744 struct perf_event *event, *next_event;
2749 update_context_time(ctx);
2751 event = list_first_entry(&ctx->event_list,
2752 struct perf_event, event_entry);
2754 next_event = list_first_entry(&next_ctx->event_list,
2755 struct perf_event, event_entry);
2757 while (&event->event_entry != &ctx->event_list &&
2758 &next_event->event_entry != &next_ctx->event_list) {
2760 __perf_event_sync_stat(event, next_event);
2762 event = list_next_entry(event, event_entry);
2763 next_event = list_next_entry(next_event, event_entry);
2767 static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
2768 struct task_struct *next)
2770 struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
2771 struct perf_event_context *next_ctx;
2772 struct perf_event_context *parent, *next_parent;
2773 struct perf_cpu_context *cpuctx;
2779 cpuctx = __get_cpu_context(ctx);
2780 if (!cpuctx->task_ctx)
2784 next_ctx = next->perf_event_ctxp[ctxn];
2788 parent = rcu_dereference(ctx->parent_ctx);
2789 next_parent = rcu_dereference(next_ctx->parent_ctx);
2791 /* If neither context have a parent context; they cannot be clones. */
2792 if (!parent && !next_parent)
2795 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
2797 * Looks like the two contexts are clones, so we might be
2798 * able to optimize the context switch. We lock both
2799 * contexts and check that they are clones under the
2800 * lock (including re-checking that neither has been
2801 * uncloned in the meantime). It doesn't matter which
2802 * order we take the locks because no other cpu could
2803 * be trying to lock both of these tasks.
2805 raw_spin_lock(&ctx->lock);
2806 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
2807 if (context_equiv(ctx, next_ctx)) {
2808 WRITE_ONCE(ctx->task, next);
2809 WRITE_ONCE(next_ctx->task, task);
2811 swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
2814 * RCU_INIT_POINTER here is safe because we've not
2815 * modified the ctx and the above modification of
2816 * ctx->task and ctx->task_ctx_data are immaterial
2817 * since those values are always verified under
2818 * ctx->lock which we're now holding.
2820 RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx);
2821 RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx);
2825 perf_event_sync_stat(ctx, next_ctx);
2827 raw_spin_unlock(&next_ctx->lock);
2828 raw_spin_unlock(&ctx->lock);
2834 raw_spin_lock(&ctx->lock);
2835 task_ctx_sched_out(cpuctx, ctx);
2836 raw_spin_unlock(&ctx->lock);
2840 void perf_sched_cb_dec(struct pmu *pmu)
2842 this_cpu_dec(perf_sched_cb_usages);
2845 void perf_sched_cb_inc(struct pmu *pmu)
2847 this_cpu_inc(perf_sched_cb_usages);
2851 * This function provides the context switch callback to the lower code
2852 * layer. It is invoked ONLY when the context switch callback is enabled.
2854 static void perf_pmu_sched_task(struct task_struct *prev,
2855 struct task_struct *next,
2858 struct perf_cpu_context *cpuctx;
2860 unsigned long flags;
2865 local_irq_save(flags);
2869 list_for_each_entry_rcu(pmu, &pmus, entry) {
2870 if (pmu->sched_task) {
2871 cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2873 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
2875 perf_pmu_disable(pmu);
2877 pmu->sched_task(cpuctx->task_ctx, sched_in);
2879 perf_pmu_enable(pmu);
2881 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2887 local_irq_restore(flags);
2890 static void perf_event_switch(struct task_struct *task,
2891 struct task_struct *next_prev, bool sched_in);
2893 #define for_each_task_context_nr(ctxn) \
2894 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2897 * Called from scheduler to remove the events of the current task,
2898 * with interrupts disabled.
2900 * We stop each event and update the event value in event->count.
2902 * This does not protect us against NMI, but disable()
2903 * sets the disabled bit in the control field of event _before_
2904 * accessing the event control register. If a NMI hits, then it will
2905 * not restart the event.
2907 void __perf_event_task_sched_out(struct task_struct *task,
2908 struct task_struct *next)
2912 if (__this_cpu_read(perf_sched_cb_usages))
2913 perf_pmu_sched_task(task, next, false);
2915 if (atomic_read(&nr_switch_events))
2916 perf_event_switch(task, next, false);
2918 for_each_task_context_nr(ctxn)
2919 perf_event_context_sched_out(task, ctxn, next);
2922 * if cgroup events exist on this CPU, then we need
2923 * to check if we have to switch out PMU state.
2924 * cgroup event are system-wide mode only
2926 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
2927 perf_cgroup_sched_out(task, next);
2931 * Called with IRQs disabled
2933 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
2934 enum event_type_t event_type)
2936 ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
2940 ctx_pinned_sched_in(struct perf_event_context *ctx,
2941 struct perf_cpu_context *cpuctx)
2943 struct perf_event *event;
2945 list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
2946 if (event->state <= PERF_EVENT_STATE_OFF)
2948 if (!event_filter_match(event))
2951 /* may need to reset tstamp_enabled */
2952 if (is_cgroup_event(event))
2953 perf_cgroup_mark_enabled(event, ctx);
2955 if (group_can_go_on(event, cpuctx, 1))
2956 group_sched_in(event, cpuctx, ctx);
2959 * If this pinned group hasn't been scheduled,
2960 * put it in error state.
2962 if (event->state == PERF_EVENT_STATE_INACTIVE) {
2963 update_group_times(event);
2964 event->state = PERF_EVENT_STATE_ERROR;
2970 ctx_flexible_sched_in(struct perf_event_context *ctx,
2971 struct perf_cpu_context *cpuctx)
2973 struct perf_event *event;
2976 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
2977 /* Ignore events in OFF or ERROR state */
2978 if (event->state <= PERF_EVENT_STATE_OFF)
2981 * Listen to the 'cpu' scheduling filter constraint
2984 if (!event_filter_match(event))
2987 /* may need to reset tstamp_enabled */
2988 if (is_cgroup_event(event))
2989 perf_cgroup_mark_enabled(event, ctx);
2991 if (group_can_go_on(event, cpuctx, can_add_hw)) {
2992 if (group_sched_in(event, cpuctx, ctx))
2999 ctx_sched_in(struct perf_event_context *ctx,
3000 struct perf_cpu_context *cpuctx,
3001 enum event_type_t event_type,
3002 struct task_struct *task)
3004 int is_active = ctx->is_active;
3007 lockdep_assert_held(&ctx->lock);
3009 if (likely(!ctx->nr_events))
3012 ctx->is_active |= (event_type | EVENT_TIME);
3015 cpuctx->task_ctx = ctx;
3017 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3020 is_active ^= ctx->is_active; /* changed bits */
3022 if (is_active & EVENT_TIME) {
3023 /* start ctx time */
3025 ctx->timestamp = now;
3026 perf_cgroup_set_timestamp(task, ctx);
3030 * First go through the list and put on any pinned groups
3031 * in order to give them the best chance of going on.
3033 if (is_active & EVENT_PINNED)
3034 ctx_pinned_sched_in(ctx, cpuctx);
3036 /* Then walk through the lower prio flexible groups */
3037 if (is_active & EVENT_FLEXIBLE)
3038 ctx_flexible_sched_in(ctx, cpuctx);
3041 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
3042 enum event_type_t event_type,
3043 struct task_struct *task)
3045 struct perf_event_context *ctx = &cpuctx->ctx;
3047 ctx_sched_in(ctx, cpuctx, event_type, task);
3050 static void perf_event_context_sched_in(struct perf_event_context *ctx,
3051 struct task_struct *task)
3053 struct perf_cpu_context *cpuctx;
3055 cpuctx = __get_cpu_context(ctx);
3056 if (cpuctx->task_ctx == ctx)
3059 perf_ctx_lock(cpuctx, ctx);
3060 perf_pmu_disable(ctx->pmu);
3062 * We want to keep the following priority order:
3063 * cpu pinned (that don't need to move), task pinned,
3064 * cpu flexible, task flexible.
3066 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3067 perf_event_sched_in(cpuctx, ctx, task);
3068 perf_pmu_enable(ctx->pmu);
3069 perf_ctx_unlock(cpuctx, ctx);
3073 * Called from scheduler to add the events of the current task
3074 * with interrupts disabled.
3076 * We restore the event value and then enable it.
3078 * This does not protect us against NMI, but enable()
3079 * sets the enabled bit in the control field of event _before_
3080 * accessing the event control register. If a NMI hits, then it will
3081 * keep the event running.
3083 void __perf_event_task_sched_in(struct task_struct *prev,
3084 struct task_struct *task)
3086 struct perf_event_context *ctx;
3090 * If cgroup events exist on this CPU, then we need to check if we have
3091 * to switch in PMU state; cgroup event are system-wide mode only.
3093 * Since cgroup events are CPU events, we must schedule these in before
3094 * we schedule in the task events.
3096 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
3097 perf_cgroup_sched_in(prev, task);
3099 for_each_task_context_nr(ctxn) {
3100 ctx = task->perf_event_ctxp[ctxn];
3104 perf_event_context_sched_in(ctx, task);
3107 if (atomic_read(&nr_switch_events))
3108 perf_event_switch(task, prev, true);
3110 if (__this_cpu_read(perf_sched_cb_usages))
3111 perf_pmu_sched_task(prev, task, true);
3114 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
3116 u64 frequency = event->attr.sample_freq;
3117 u64 sec = NSEC_PER_SEC;
3118 u64 divisor, dividend;
3120 int count_fls, nsec_fls, frequency_fls, sec_fls;
3122 count_fls = fls64(count);
3123 nsec_fls = fls64(nsec);
3124 frequency_fls = fls64(frequency);
3128 * We got @count in @nsec, with a target of sample_freq HZ
3129 * the target period becomes:
3132 * period = -------------------
3133 * @nsec * sample_freq
3138 * Reduce accuracy by one bit such that @a and @b converge
3139 * to a similar magnitude.
3141 #define REDUCE_FLS(a, b) \
3143 if (a##_fls > b##_fls) { \
3153 * Reduce accuracy until either term fits in a u64, then proceed with
3154 * the other, so that finally we can do a u64/u64 division.
3156 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
3157 REDUCE_FLS(nsec, frequency);
3158 REDUCE_FLS(sec, count);
3161 if (count_fls + sec_fls > 64) {
3162 divisor = nsec * frequency;
3164 while (count_fls + sec_fls > 64) {
3165 REDUCE_FLS(count, sec);
3169 dividend = count * sec;
3171 dividend = count * sec;
3173 while (nsec_fls + frequency_fls > 64) {
3174 REDUCE_FLS(nsec, frequency);
3178 divisor = nsec * frequency;
3184 return div64_u64(dividend, divisor);
3187 static DEFINE_PER_CPU(int, perf_throttled_count);
3188 static DEFINE_PER_CPU(u64, perf_throttled_seq);
3190 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
3192 struct hw_perf_event *hwc = &event->hw;
3193 s64 period, sample_period;
3196 period = perf_calculate_period(event, nsec, count);
3198 delta = (s64)(period - hwc->sample_period);
3199 delta = (delta + 7) / 8; /* low pass filter */
3201 sample_period = hwc->sample_period + delta;
3206 hwc->sample_period = sample_period;
3208 if (local64_read(&hwc->period_left) > 8*sample_period) {
3210 event->pmu->stop(event, PERF_EF_UPDATE);
3212 local64_set(&hwc->period_left, 0);
3215 event->pmu->start(event, PERF_EF_RELOAD);
3220 * combine freq adjustment with unthrottling to avoid two passes over the
3221 * events. At the same time, make sure, having freq events does not change
3222 * the rate of unthrottling as that would introduce bias.
3224 static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
3227 struct perf_event *event;
3228 struct hw_perf_event *hwc;
3229 u64 now, period = TICK_NSEC;
3233 * only need to iterate over all events iff:
3234 * - context have events in frequency mode (needs freq adjust)
3235 * - there are events to unthrottle on this cpu
3237 if (!(ctx->nr_freq || needs_unthr))
3240 raw_spin_lock(&ctx->lock);
3241 perf_pmu_disable(ctx->pmu);
3243 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3244 if (event->state != PERF_EVENT_STATE_ACTIVE)
3247 if (!event_filter_match(event))
3250 perf_pmu_disable(event->pmu);
3254 if (hwc->interrupts == MAX_INTERRUPTS) {
3255 hwc->interrupts = 0;
3256 perf_log_throttle(event, 1);
3257 event->pmu->start(event, 0);
3260 if (!event->attr.freq || !event->attr.sample_freq)
3264 * stop the event and update event->count
3266 event->pmu->stop(event, PERF_EF_UPDATE);
3268 now = local64_read(&event->count);
3269 delta = now - hwc->freq_count_stamp;
3270 hwc->freq_count_stamp = now;
3274 * reload only if value has changed
3275 * we have stopped the event so tell that
3276 * to perf_adjust_period() to avoid stopping it
3280 perf_adjust_period(event, period, delta, false);
3282 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
3284 perf_pmu_enable(event->pmu);
3287 perf_pmu_enable(ctx->pmu);
3288 raw_spin_unlock(&ctx->lock);
3292 * Round-robin a context's events:
3294 static void rotate_ctx(struct perf_event_context *ctx)
3297 * Rotate the first entry last of non-pinned groups. Rotation might be
3298 * disabled by the inheritance code.
3300 if (!ctx->rotate_disable)
3301 list_rotate_left(&ctx->flexible_groups);
3304 static int perf_rotate_context(struct perf_cpu_context *cpuctx)
3306 struct perf_event_context *ctx = NULL;
3309 if (cpuctx->ctx.nr_events) {
3310 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
3314 ctx = cpuctx->task_ctx;
3315 if (ctx && ctx->nr_events) {
3316 if (ctx->nr_events != ctx->nr_active)
3323 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3324 perf_pmu_disable(cpuctx->ctx.pmu);
3326 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3328 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
3330 rotate_ctx(&cpuctx->ctx);
3334 perf_event_sched_in(cpuctx, ctx, current);
3336 perf_pmu_enable(cpuctx->ctx.pmu);
3337 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3343 void perf_event_task_tick(void)
3345 struct list_head *head = this_cpu_ptr(&active_ctx_list);
3346 struct perf_event_context *ctx, *tmp;
3349 WARN_ON(!irqs_disabled());
3351 __this_cpu_inc(perf_throttled_seq);
3352 throttled = __this_cpu_xchg(perf_throttled_count, 0);
3353 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
3355 list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
3356 perf_adjust_freq_unthr_context(ctx, throttled);
3359 static int event_enable_on_exec(struct perf_event *event,
3360 struct perf_event_context *ctx)
3362 if (!event->attr.enable_on_exec)
3365 event->attr.enable_on_exec = 0;
3366 if (event->state >= PERF_EVENT_STATE_INACTIVE)
3369 __perf_event_mark_enabled(event);
3375 * Enable all of a task's events that have been marked enable-on-exec.
3376 * This expects task == current.
3378 static void perf_event_enable_on_exec(int ctxn)
3380 struct perf_event_context *ctx, *clone_ctx = NULL;
3381 struct perf_cpu_context *cpuctx;
3382 struct perf_event *event;
3383 unsigned long flags;
3386 local_irq_save(flags);
3387 ctx = current->perf_event_ctxp[ctxn];
3388 if (!ctx || !ctx->nr_events)
3391 cpuctx = __get_cpu_context(ctx);
3392 perf_ctx_lock(cpuctx, ctx);
3393 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
3394 list_for_each_entry(event, &ctx->event_list, event_entry)
3395 enabled |= event_enable_on_exec(event, ctx);
3398 * Unclone and reschedule this context if we enabled any event.
3401 clone_ctx = unclone_ctx(ctx);
3402 ctx_resched(cpuctx, ctx);
3404 perf_ctx_unlock(cpuctx, ctx);
3407 local_irq_restore(flags);
3413 struct perf_read_data {
3414 struct perf_event *event;
3420 * Cross CPU call to read the hardware event
3422 static void __perf_event_read(void *info)
3424 struct perf_read_data *data = info;
3425 struct perf_event *sub, *event = data->event;
3426 struct perf_event_context *ctx = event->ctx;
3427 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
3428 struct pmu *pmu = event->pmu;
3431 * If this is a task context, we need to check whether it is
3432 * the current task context of this cpu. If not it has been
3433 * scheduled out before the smp call arrived. In that case
3434 * event->count would have been updated to a recent sample
3435 * when the event was scheduled out.
3437 if (ctx->task && cpuctx->task_ctx != ctx)
3440 raw_spin_lock(&ctx->lock);
3441 if (ctx->is_active) {
3442 update_context_time(ctx);
3443 update_cgrp_time_from_event(event);
3446 update_event_times(event);
3447 if (event->state != PERF_EVENT_STATE_ACTIVE)
3456 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
3460 list_for_each_entry(sub, &event->sibling_list, group_entry) {
3461 update_event_times(sub);
3462 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
3464 * Use sibling's PMU rather than @event's since
3465 * sibling could be on different (eg: software) PMU.
3467 sub->pmu->read(sub);
3471 data->ret = pmu->commit_txn(pmu);
3474 raw_spin_unlock(&ctx->lock);
3477 static inline u64 perf_event_count(struct perf_event *event)
3479 if (event->pmu->count)
3480 return event->pmu->count(event);
3482 return __perf_event_count(event);
3486 * NMI-safe method to read a local event, that is an event that
3488 * - either for the current task, or for this CPU
3489 * - does not have inherit set, for inherited task events
3490 * will not be local and we cannot read them atomically
3491 * - must not have a pmu::count method
3493 u64 perf_event_read_local(struct perf_event *event)
3495 unsigned long flags;
3499 * Disabling interrupts avoids all counter scheduling (context
3500 * switches, timer based rotation and IPIs).
3502 local_irq_save(flags);
3504 /* If this is a per-task event, it must be for current */
3505 WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
3506 event->hw.target != current);
3508 /* If this is a per-CPU event, it must be for this CPU */
3509 WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
3510 event->cpu != smp_processor_id());
3513 * It must not be an event with inherit set, we cannot read
3514 * all child counters from atomic context.
3516 WARN_ON_ONCE(event->attr.inherit);
3519 * It must not have a pmu::count method, those are not
3522 WARN_ON_ONCE(event->pmu->count);
3525 * If the event is currently on this CPU, its either a per-task event,
3526 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3529 if (event->oncpu == smp_processor_id())
3530 event->pmu->read(event);
3532 val = local64_read(&event->count);
3533 local_irq_restore(flags);
3538 static int perf_event_read(struct perf_event *event, bool group)
3543 * If event is enabled and currently active on a CPU, update the
3544 * value in the event structure:
3546 if (event->state == PERF_EVENT_STATE_ACTIVE) {
3547 struct perf_read_data data = {
3552 ret = smp_call_function_single(event->oncpu, __perf_event_read, &data, 1);
3553 /* The event must have been read from an online CPU: */
3555 ret = ret ? : data.ret;
3556 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
3557 struct perf_event_context *ctx = event->ctx;
3558 unsigned long flags;
3560 raw_spin_lock_irqsave(&ctx->lock, flags);
3562 * may read while context is not active
3563 * (e.g., thread is blocked), in that case
3564 * we cannot update context time
3566 if (ctx->is_active) {
3567 update_context_time(ctx);
3568 update_cgrp_time_from_event(event);
3571 update_group_times(event);
3573 update_event_times(event);
3574 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3581 * Initialize the perf_event context in a task_struct:
3583 static void __perf_event_init_context(struct perf_event_context *ctx)
3585 raw_spin_lock_init(&ctx->lock);
3586 mutex_init(&ctx->mutex);
3587 INIT_LIST_HEAD(&ctx->active_ctx_list);
3588 INIT_LIST_HEAD(&ctx->pinned_groups);
3589 INIT_LIST_HEAD(&ctx->flexible_groups);
3590 INIT_LIST_HEAD(&ctx->event_list);
3591 atomic_set(&ctx->refcount, 1);
3594 static struct perf_event_context *
3595 alloc_perf_context(struct pmu *pmu, struct task_struct *task)
3597 struct perf_event_context *ctx;
3599 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
3603 __perf_event_init_context(ctx);
3606 get_task_struct(task);
3613 static struct task_struct *
3614 find_lively_task_by_vpid(pid_t vpid)
3616 struct task_struct *task;
3622 task = find_task_by_vpid(vpid);
3624 get_task_struct(task);
3628 return ERR_PTR(-ESRCH);
3634 * Returns a matching context with refcount and pincount.
3636 static struct perf_event_context *
3637 find_get_context(struct pmu *pmu, struct task_struct *task,
3638 struct perf_event *event)
3640 struct perf_event_context *ctx, *clone_ctx = NULL;
3641 struct perf_cpu_context *cpuctx;
3642 void *task_ctx_data = NULL;
3643 unsigned long flags;
3645 int cpu = event->cpu;
3648 /* Must be root to operate on a CPU event: */
3649 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
3650 return ERR_PTR(-EACCES);
3653 * We could be clever and allow to attach a event to an
3654 * offline CPU and activate it when the CPU comes up, but
3657 if (!cpu_online(cpu))
3658 return ERR_PTR(-ENODEV);
3660 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
3669 ctxn = pmu->task_ctx_nr;
3673 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
3674 task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
3675 if (!task_ctx_data) {
3682 ctx = perf_lock_task_context(task, ctxn, &flags);
3684 clone_ctx = unclone_ctx(ctx);
3687 if (task_ctx_data && !ctx->task_ctx_data) {
3688 ctx->task_ctx_data = task_ctx_data;
3689 task_ctx_data = NULL;
3691 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3696 ctx = alloc_perf_context(pmu, task);
3701 if (task_ctx_data) {
3702 ctx->task_ctx_data = task_ctx_data;
3703 task_ctx_data = NULL;
3707 mutex_lock(&task->perf_event_mutex);
3709 * If it has already passed perf_event_exit_task().
3710 * we must see PF_EXITING, it takes this mutex too.
3712 if (task->flags & PF_EXITING)
3714 else if (task->perf_event_ctxp[ctxn])
3719 rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
3721 mutex_unlock(&task->perf_event_mutex);
3723 if (unlikely(err)) {
3732 kfree(task_ctx_data);
3736 kfree(task_ctx_data);
3737 return ERR_PTR(err);
3740 static void perf_event_free_filter(struct perf_event *event);
3741 static void perf_event_free_bpf_prog(struct perf_event *event);
3743 static void free_event_rcu(struct rcu_head *head)
3745 struct perf_event *event;
3747 event = container_of(head, struct perf_event, rcu_head);
3749 put_pid_ns(event->ns);
3750 perf_event_free_filter(event);
3754 static void ring_buffer_attach(struct perf_event *event,
3755 struct ring_buffer *rb);
3757 static void detach_sb_event(struct perf_event *event)
3759 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
3761 raw_spin_lock(&pel->lock);
3762 list_del_rcu(&event->sb_list);
3763 raw_spin_unlock(&pel->lock);
3766 static bool is_sb_event(struct perf_event *event)
3768 struct perf_event_attr *attr = &event->attr;
3773 if (event->attach_state & PERF_ATTACH_TASK)
3776 if (attr->mmap || attr->mmap_data || attr->mmap2 ||
3777 attr->comm || attr->comm_exec ||
3779 attr->context_switch)
3784 static void unaccount_pmu_sb_event(struct perf_event *event)
3786 if (is_sb_event(event))
3787 detach_sb_event(event);
3790 static void unaccount_event_cpu(struct perf_event *event, int cpu)
3795 if (is_cgroup_event(event))
3796 atomic_dec(&per_cpu(perf_cgroup_events, cpu));
3799 #ifdef CONFIG_NO_HZ_FULL
3800 static DEFINE_SPINLOCK(nr_freq_lock);
3803 static void unaccount_freq_event_nohz(void)
3805 #ifdef CONFIG_NO_HZ_FULL
3806 spin_lock(&nr_freq_lock);
3807 if (atomic_dec_and_test(&nr_freq_events))
3808 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
3809 spin_unlock(&nr_freq_lock);
3813 static void unaccount_freq_event(void)
3815 if (tick_nohz_full_enabled())
3816 unaccount_freq_event_nohz();
3818 atomic_dec(&nr_freq_events);
3821 static void unaccount_event(struct perf_event *event)
3828 if (event->attach_state & PERF_ATTACH_TASK)
3830 if (event->attr.mmap || event->attr.mmap_data)
3831 atomic_dec(&nr_mmap_events);
3832 if (event->attr.comm)
3833 atomic_dec(&nr_comm_events);
3834 if (event->attr.task)
3835 atomic_dec(&nr_task_events);
3836 if (event->attr.freq)
3837 unaccount_freq_event();
3838 if (event->attr.context_switch) {
3840 atomic_dec(&nr_switch_events);
3842 if (is_cgroup_event(event))
3844 if (has_branch_stack(event))
3848 if (!atomic_add_unless(&perf_sched_count, -1, 1))
3849 schedule_delayed_work(&perf_sched_work, HZ);
3852 unaccount_event_cpu(event, event->cpu);
3854 unaccount_pmu_sb_event(event);
3857 static void perf_sched_delayed(struct work_struct *work)
3859 mutex_lock(&perf_sched_mutex);
3860 if (atomic_dec_and_test(&perf_sched_count))
3861 static_branch_disable(&perf_sched_events);
3862 mutex_unlock(&perf_sched_mutex);
3866 * The following implement mutual exclusion of events on "exclusive" pmus
3867 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3868 * at a time, so we disallow creating events that might conflict, namely:
3870 * 1) cpu-wide events in the presence of per-task events,
3871 * 2) per-task events in the presence of cpu-wide events,
3872 * 3) two matching events on the same context.
3874 * The former two cases are handled in the allocation path (perf_event_alloc(),
3875 * _free_event()), the latter -- before the first perf_install_in_context().
3877 static int exclusive_event_init(struct perf_event *event)
3879 struct pmu *pmu = event->pmu;
3881 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3885 * Prevent co-existence of per-task and cpu-wide events on the
3886 * same exclusive pmu.
3888 * Negative pmu::exclusive_cnt means there are cpu-wide
3889 * events on this "exclusive" pmu, positive means there are
3892 * Since this is called in perf_event_alloc() path, event::ctx
3893 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3894 * to mean "per-task event", because unlike other attach states it
3895 * never gets cleared.
3897 if (event->attach_state & PERF_ATTACH_TASK) {
3898 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
3901 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
3908 static void exclusive_event_destroy(struct perf_event *event)
3910 struct pmu *pmu = event->pmu;
3912 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3915 /* see comment in exclusive_event_init() */
3916 if (event->attach_state & PERF_ATTACH_TASK)
3917 atomic_dec(&pmu->exclusive_cnt);
3919 atomic_inc(&pmu->exclusive_cnt);
3922 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
3924 if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
3925 (e1->cpu == e2->cpu ||
3932 /* Called under the same ctx::mutex as perf_install_in_context() */
3933 static bool exclusive_event_installable(struct perf_event *event,
3934 struct perf_event_context *ctx)
3936 struct perf_event *iter_event;
3937 struct pmu *pmu = event->pmu;
3939 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3942 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
3943 if (exclusive_event_match(iter_event, event))
3950 static void perf_addr_filters_splice(struct perf_event *event,
3951 struct list_head *head);
3953 static void _free_event(struct perf_event *event)
3955 irq_work_sync(&event->pending);
3957 unaccount_event(event);
3961 * Can happen when we close an event with re-directed output.
3963 * Since we have a 0 refcount, perf_mmap_close() will skip
3964 * over us; possibly making our ring_buffer_put() the last.
3966 mutex_lock(&event->mmap_mutex);
3967 ring_buffer_attach(event, NULL);
3968 mutex_unlock(&event->mmap_mutex);
3971 if (is_cgroup_event(event))
3972 perf_detach_cgroup(event);
3974 if (!event->parent) {
3975 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
3976 put_callchain_buffers();
3979 perf_event_free_bpf_prog(event);
3980 perf_addr_filters_splice(event, NULL);
3981 kfree(event->addr_filters_offs);
3984 event->destroy(event);
3987 put_ctx(event->ctx);
3989 exclusive_event_destroy(event);
3990 module_put(event->pmu->module);
3992 call_rcu(&event->rcu_head, free_event_rcu);
3996 * Used to free events which have a known refcount of 1, such as in error paths
3997 * where the event isn't exposed yet and inherited events.
3999 static void free_event(struct perf_event *event)
4001 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
4002 "unexpected event refcount: %ld; ptr=%p\n",
4003 atomic_long_read(&event->refcount), event)) {
4004 /* leak to avoid use-after-free */
4012 * Remove user event from the owner task.
4014 static void perf_remove_from_owner(struct perf_event *event)
4016 struct task_struct *owner;
4020 * Matches the smp_store_release() in perf_event_exit_task(). If we
4021 * observe !owner it means the list deletion is complete and we can
4022 * indeed free this event, otherwise we need to serialize on
4023 * owner->perf_event_mutex.
4025 owner = lockless_dereference(event->owner);
4028 * Since delayed_put_task_struct() also drops the last
4029 * task reference we can safely take a new reference
4030 * while holding the rcu_read_lock().
4032 get_task_struct(owner);
4038 * If we're here through perf_event_exit_task() we're already
4039 * holding ctx->mutex which would be an inversion wrt. the
4040 * normal lock order.
4042 * However we can safely take this lock because its the child
4045 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
4048 * We have to re-check the event->owner field, if it is cleared
4049 * we raced with perf_event_exit_task(), acquiring the mutex
4050 * ensured they're done, and we can proceed with freeing the
4054 list_del_init(&event->owner_entry);
4055 smp_store_release(&event->owner, NULL);
4057 mutex_unlock(&owner->perf_event_mutex);
4058 put_task_struct(owner);
4062 static void put_event(struct perf_event *event)
4064 if (!atomic_long_dec_and_test(&event->refcount))
4071 * Kill an event dead; while event:refcount will preserve the event
4072 * object, it will not preserve its functionality. Once the last 'user'
4073 * gives up the object, we'll destroy the thing.
4075 int perf_event_release_kernel(struct perf_event *event)
4077 struct perf_event_context *ctx = event->ctx;
4078 struct perf_event *child, *tmp;
4081 * If we got here through err_file: fput(event_file); we will not have
4082 * attached to a context yet.
4085 WARN_ON_ONCE(event->attach_state &
4086 (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
4090 if (!is_kernel_event(event))
4091 perf_remove_from_owner(event);
4093 ctx = perf_event_ctx_lock(event);
4094 WARN_ON_ONCE(ctx->parent_ctx);
4095 perf_remove_from_context(event, DETACH_GROUP);
4097 raw_spin_lock_irq(&ctx->lock);
4099 * Mark this even as STATE_DEAD, there is no external reference to it
4102 * Anybody acquiring event->child_mutex after the below loop _must_
4103 * also see this, most importantly inherit_event() which will avoid
4104 * placing more children on the list.
4106 * Thus this guarantees that we will in fact observe and kill _ALL_
4109 event->state = PERF_EVENT_STATE_DEAD;
4110 raw_spin_unlock_irq(&ctx->lock);
4112 perf_event_ctx_unlock(event, ctx);
4115 mutex_lock(&event->child_mutex);
4116 list_for_each_entry(child, &event->child_list, child_list) {
4119 * Cannot change, child events are not migrated, see the
4120 * comment with perf_event_ctx_lock_nested().
4122 ctx = lockless_dereference(child->ctx);
4124 * Since child_mutex nests inside ctx::mutex, we must jump
4125 * through hoops. We start by grabbing a reference on the ctx.
4127 * Since the event cannot get freed while we hold the
4128 * child_mutex, the context must also exist and have a !0
4134 * Now that we have a ctx ref, we can drop child_mutex, and
4135 * acquire ctx::mutex without fear of it going away. Then we
4136 * can re-acquire child_mutex.
4138 mutex_unlock(&event->child_mutex);
4139 mutex_lock(&ctx->mutex);
4140 mutex_lock(&event->child_mutex);
4143 * Now that we hold ctx::mutex and child_mutex, revalidate our
4144 * state, if child is still the first entry, it didn't get freed
4145 * and we can continue doing so.
4147 tmp = list_first_entry_or_null(&event->child_list,
4148 struct perf_event, child_list);
4150 perf_remove_from_context(child, DETACH_GROUP);
4151 list_del(&child->child_list);
4154 * This matches the refcount bump in inherit_event();
4155 * this can't be the last reference.
4160 mutex_unlock(&event->child_mutex);
4161 mutex_unlock(&ctx->mutex);
4165 mutex_unlock(&event->child_mutex);
4168 put_event(event); /* Must be the 'last' reference */
4171 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
4174 * Called when the last reference to the file is gone.
4176 static int perf_release(struct inode *inode, struct file *file)
4178 perf_event_release_kernel(file->private_data);
4182 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
4184 struct perf_event *child;
4190 mutex_lock(&event->child_mutex);
4192 (void)perf_event_read(event, false);
4193 total += perf_event_count(event);
4195 *enabled += event->total_time_enabled +
4196 atomic64_read(&event->child_total_time_enabled);
4197 *running += event->total_time_running +
4198 atomic64_read(&event->child_total_time_running);
4200 list_for_each_entry(child, &event->child_list, child_list) {
4201 (void)perf_event_read(child, false);
4202 total += perf_event_count(child);
4203 *enabled += child->total_time_enabled;
4204 *running += child->total_time_running;
4206 mutex_unlock(&event->child_mutex);
4210 EXPORT_SYMBOL_GPL(perf_event_read_value);
4212 static int __perf_read_group_add(struct perf_event *leader,
4213 u64 read_format, u64 *values)
4215 struct perf_event *sub;
4216 int n = 1; /* skip @nr */
4219 ret = perf_event_read(leader, true);
4224 * Since we co-schedule groups, {enabled,running} times of siblings
4225 * will be identical to those of the leader, so we only publish one
4228 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
4229 values[n++] += leader->total_time_enabled +
4230 atomic64_read(&leader->child_total_time_enabled);
4233 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
4234 values[n++] += leader->total_time_running +
4235 atomic64_read(&leader->child_total_time_running);
4239 * Write {count,id} tuples for every sibling.
4241 values[n++] += perf_event_count(leader);
4242 if (read_format & PERF_FORMAT_ID)
4243 values[n++] = primary_event_id(leader);
4245 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
4246 values[n++] += perf_event_count(sub);
4247 if (read_format & PERF_FORMAT_ID)
4248 values[n++] = primary_event_id(sub);
4254 static int perf_read_group(struct perf_event *event,
4255 u64 read_format, char __user *buf)
4257 struct perf_event *leader = event->group_leader, *child;
4258 struct perf_event_context *ctx = leader->ctx;
4262 lockdep_assert_held(&ctx->mutex);
4264 values = kzalloc(event->read_size, GFP_KERNEL);
4268 values[0] = 1 + leader->nr_siblings;
4271 * By locking the child_mutex of the leader we effectively
4272 * lock the child list of all siblings.. XXX explain how.
4274 mutex_lock(&leader->child_mutex);
4276 ret = __perf_read_group_add(leader, read_format, values);
4280 list_for_each_entry(child, &leader->child_list, child_list) {
4281 ret = __perf_read_group_add(child, read_format, values);
4286 mutex_unlock(&leader->child_mutex);
4288 ret = event->read_size;
4289 if (copy_to_user(buf, values, event->read_size))
4294 mutex_unlock(&leader->child_mutex);
4300 static int perf_read_one(struct perf_event *event,
4301 u64 read_format, char __user *buf)
4303 u64 enabled, running;
4307 values[n++] = perf_event_read_value(event, &enabled, &running);
4308 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
4309 values[n++] = enabled;
4310 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
4311 values[n++] = running;
4312 if (read_format & PERF_FORMAT_ID)
4313 values[n++] = primary_event_id(event);
4315 if (copy_to_user(buf, values, n * sizeof(u64)))
4318 return n * sizeof(u64);
4321 static bool is_event_hup(struct perf_event *event)
4325 if (event->state > PERF_EVENT_STATE_EXIT)
4328 mutex_lock(&event->child_mutex);
4329 no_children = list_empty(&event->child_list);
4330 mutex_unlock(&event->child_mutex);
4335 * Read the performance event - simple non blocking version for now
4338 __perf_read(struct perf_event *event, char __user *buf, size_t count)
4340 u64 read_format = event->attr.read_format;
4344 * Return end-of-file for a read on a event that is in
4345 * error state (i.e. because it was pinned but it couldn't be
4346 * scheduled on to the CPU at some point).
4348 if (event->state == PERF_EVENT_STATE_ERROR)
4351 if (count < event->read_size)
4354 WARN_ON_ONCE(event->ctx->parent_ctx);
4355 if (read_format & PERF_FORMAT_GROUP)
4356 ret = perf_read_group(event, read_format, buf);
4358 ret = perf_read_one(event, read_format, buf);
4364 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
4366 struct perf_event *event = file->private_data;
4367 struct perf_event_context *ctx;
4370 ctx = perf_event_ctx_lock(event);
4371 ret = __perf_read(event, buf, count);
4372 perf_event_ctx_unlock(event, ctx);
4377 static unsigned int perf_poll(struct file *file, poll_table *wait)
4379 struct perf_event *event = file->private_data;
4380 struct ring_buffer *rb;
4381 unsigned int events = POLLHUP;
4383 poll_wait(file, &event->waitq, wait);
4385 if (is_event_hup(event))
4389 * Pin the event->rb by taking event->mmap_mutex; otherwise
4390 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4392 mutex_lock(&event->mmap_mutex);
4395 events = atomic_xchg(&rb->poll, 0);
4396 mutex_unlock(&event->mmap_mutex);
4400 static void _perf_event_reset(struct perf_event *event)
4402 (void)perf_event_read(event, false);
4403 local64_set(&event->count, 0);
4404 perf_event_update_userpage(event);
4408 * Holding the top-level event's child_mutex means that any
4409 * descendant process that has inherited this event will block
4410 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4411 * task existence requirements of perf_event_enable/disable.
4413 static void perf_event_for_each_child(struct perf_event *event,
4414 void (*func)(struct perf_event *))
4416 struct perf_event *child;
4418 WARN_ON_ONCE(event->ctx->parent_ctx);
4420 mutex_lock(&event->child_mutex);
4422 list_for_each_entry(child, &event->child_list, child_list)
4424 mutex_unlock(&event->child_mutex);
4427 static void perf_event_for_each(struct perf_event *event,
4428 void (*func)(struct perf_event *))
4430 struct perf_event_context *ctx = event->ctx;
4431 struct perf_event *sibling;
4433 lockdep_assert_held(&ctx->mutex);
4435 event = event->group_leader;
4437 perf_event_for_each_child(event, func);
4438 list_for_each_entry(sibling, &event->sibling_list, group_entry)
4439 perf_event_for_each_child(sibling, func);
4442 static void __perf_event_period(struct perf_event *event,
4443 struct perf_cpu_context *cpuctx,
4444 struct perf_event_context *ctx,
4447 u64 value = *((u64 *)info);
4450 if (event->attr.freq) {
4451 event->attr.sample_freq = value;
4453 event->attr.sample_period = value;
4454 event->hw.sample_period = value;
4457 active = (event->state == PERF_EVENT_STATE_ACTIVE);
4459 perf_pmu_disable(ctx->pmu);
4461 * We could be throttled; unthrottle now to avoid the tick
4462 * trying to unthrottle while we already re-started the event.
4464 if (event->hw.interrupts == MAX_INTERRUPTS) {
4465 event->hw.interrupts = 0;
4466 perf_log_throttle(event, 1);
4468 event->pmu->stop(event, PERF_EF_UPDATE);
4471 local64_set(&event->hw.period_left, 0);
4474 event->pmu->start(event, PERF_EF_RELOAD);
4475 perf_pmu_enable(ctx->pmu);
4479 static int perf_event_period(struct perf_event *event, u64 __user *arg)
4483 if (!is_sampling_event(event))
4486 if (copy_from_user(&value, arg, sizeof(value)))
4492 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
4495 event_function_call(event, __perf_event_period, &value);
4500 static const struct file_operations perf_fops;
4502 static inline int perf_fget_light(int fd, struct fd *p)
4504 struct fd f = fdget(fd);
4508 if (f.file->f_op != &perf_fops) {
4516 static int perf_event_set_output(struct perf_event *event,
4517 struct perf_event *output_event);
4518 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
4519 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd);
4521 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
4523 void (*func)(struct perf_event *);
4527 case PERF_EVENT_IOC_ENABLE:
4528 func = _perf_event_enable;
4530 case PERF_EVENT_IOC_DISABLE:
4531 func = _perf_event_disable;
4533 case PERF_EVENT_IOC_RESET:
4534 func = _perf_event_reset;
4537 case PERF_EVENT_IOC_REFRESH:
4538 return _perf_event_refresh(event, arg);
4540 case PERF_EVENT_IOC_PERIOD:
4541 return perf_event_period(event, (u64 __user *)arg);
4543 case PERF_EVENT_IOC_ID:
4545 u64 id = primary_event_id(event);
4547 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
4552 case PERF_EVENT_IOC_SET_OUTPUT:
4556 struct perf_event *output_event;
4558 ret = perf_fget_light(arg, &output);
4561 output_event = output.file->private_data;
4562 ret = perf_event_set_output(event, output_event);
4565 ret = perf_event_set_output(event, NULL);
4570 case PERF_EVENT_IOC_SET_FILTER:
4571 return perf_event_set_filter(event, (void __user *)arg);
4573 case PERF_EVENT_IOC_SET_BPF:
4574 return perf_event_set_bpf_prog(event, arg);
4576 case PERF_EVENT_IOC_PAUSE_OUTPUT: {
4577 struct ring_buffer *rb;
4580 rb = rcu_dereference(event->rb);
4581 if (!rb || !rb->nr_pages) {
4585 rb_toggle_paused(rb, !!arg);
4593 if (flags & PERF_IOC_FLAG_GROUP)
4594 perf_event_for_each(event, func);
4596 perf_event_for_each_child(event, func);
4601 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4603 struct perf_event *event = file->private_data;
4604 struct perf_event_context *ctx;
4607 ctx = perf_event_ctx_lock(event);
4608 ret = _perf_ioctl(event, cmd, arg);
4609 perf_event_ctx_unlock(event, ctx);
4614 #ifdef CONFIG_COMPAT
4615 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
4618 switch (_IOC_NR(cmd)) {
4619 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
4620 case _IOC_NR(PERF_EVENT_IOC_ID):
4621 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4622 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
4623 cmd &= ~IOCSIZE_MASK;
4624 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
4628 return perf_ioctl(file, cmd, arg);
4631 # define perf_compat_ioctl NULL
4634 int perf_event_task_enable(void)
4636 struct perf_event_context *ctx;
4637 struct perf_event *event;
4639 mutex_lock(¤t->perf_event_mutex);
4640 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4641 ctx = perf_event_ctx_lock(event);
4642 perf_event_for_each_child(event, _perf_event_enable);
4643 perf_event_ctx_unlock(event, ctx);
4645 mutex_unlock(¤t->perf_event_mutex);
4650 int perf_event_task_disable(void)
4652 struct perf_event_context *ctx;
4653 struct perf_event *event;
4655 mutex_lock(¤t->perf_event_mutex);
4656 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4657 ctx = perf_event_ctx_lock(event);
4658 perf_event_for_each_child(event, _perf_event_disable);
4659 perf_event_ctx_unlock(event, ctx);
4661 mutex_unlock(¤t->perf_event_mutex);
4666 static int perf_event_index(struct perf_event *event)
4668 if (event->hw.state & PERF_HES_STOPPED)
4671 if (event->state != PERF_EVENT_STATE_ACTIVE)
4674 return event->pmu->event_idx(event);
4677 static void calc_timer_values(struct perf_event *event,
4684 *now = perf_clock();
4685 ctx_time = event->shadow_ctx_time + *now;
4686 *enabled = ctx_time - event->tstamp_enabled;
4687 *running = ctx_time - event->tstamp_running;
4690 static void perf_event_init_userpage(struct perf_event *event)
4692 struct perf_event_mmap_page *userpg;
4693 struct ring_buffer *rb;
4696 rb = rcu_dereference(event->rb);
4700 userpg = rb->user_page;
4702 /* Allow new userspace to detect that bit 0 is deprecated */
4703 userpg->cap_bit0_is_deprecated = 1;
4704 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
4705 userpg->data_offset = PAGE_SIZE;
4706 userpg->data_size = perf_data_size(rb);
4712 void __weak arch_perf_update_userpage(
4713 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
4718 * Callers need to ensure there can be no nesting of this function, otherwise
4719 * the seqlock logic goes bad. We can not serialize this because the arch
4720 * code calls this from NMI context.
4722 void perf_event_update_userpage(struct perf_event *event)
4724 struct perf_event_mmap_page *userpg;
4725 struct ring_buffer *rb;
4726 u64 enabled, running, now;
4729 rb = rcu_dereference(event->rb);
4734 * compute total_time_enabled, total_time_running
4735 * based on snapshot values taken when the event
4736 * was last scheduled in.
4738 * we cannot simply called update_context_time()
4739 * because of locking issue as we can be called in
4742 calc_timer_values(event, &now, &enabled, &running);
4744 userpg = rb->user_page;
4746 * Disable preemption so as to not let the corresponding user-space
4747 * spin too long if we get preempted.
4752 userpg->index = perf_event_index(event);
4753 userpg->offset = perf_event_count(event);
4755 userpg->offset -= local64_read(&event->hw.prev_count);
4757 userpg->time_enabled = enabled +
4758 atomic64_read(&event->child_total_time_enabled);
4760 userpg->time_running = running +
4761 atomic64_read(&event->child_total_time_running);
4763 arch_perf_update_userpage(event, userpg, now);
4772 static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
4774 struct perf_event *event = vma->vm_file->private_data;
4775 struct ring_buffer *rb;
4776 int ret = VM_FAULT_SIGBUS;
4778 if (vmf->flags & FAULT_FLAG_MKWRITE) {
4779 if (vmf->pgoff == 0)
4785 rb = rcu_dereference(event->rb);
4789 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
4792 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
4796 get_page(vmf->page);
4797 vmf->page->mapping = vma->vm_file->f_mapping;
4798 vmf->page->index = vmf->pgoff;
4807 static void ring_buffer_attach(struct perf_event *event,
4808 struct ring_buffer *rb)
4810 struct ring_buffer *old_rb = NULL;
4811 unsigned long flags;
4815 * Should be impossible, we set this when removing
4816 * event->rb_entry and wait/clear when adding event->rb_entry.
4818 WARN_ON_ONCE(event->rcu_pending);
4821 spin_lock_irqsave(&old_rb->event_lock, flags);
4822 list_del_rcu(&event->rb_entry);
4823 spin_unlock_irqrestore(&old_rb->event_lock, flags);
4825 event->rcu_batches = get_state_synchronize_rcu();
4826 event->rcu_pending = 1;
4830 if (event->rcu_pending) {
4831 cond_synchronize_rcu(event->rcu_batches);
4832 event->rcu_pending = 0;
4835 spin_lock_irqsave(&rb->event_lock, flags);
4836 list_add_rcu(&event->rb_entry, &rb->event_list);
4837 spin_unlock_irqrestore(&rb->event_lock, flags);
4840 rcu_assign_pointer(event->rb, rb);
4843 ring_buffer_put(old_rb);
4845 * Since we detached before setting the new rb, so that we
4846 * could attach the new rb, we could have missed a wakeup.
4849 wake_up_all(&event->waitq);
4853 static void ring_buffer_wakeup(struct perf_event *event)
4855 struct ring_buffer *rb;
4858 rb = rcu_dereference(event->rb);
4860 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
4861 wake_up_all(&event->waitq);
4866 struct ring_buffer *ring_buffer_get(struct perf_event *event)
4868 struct ring_buffer *rb;
4871 rb = rcu_dereference(event->rb);
4873 if (!atomic_inc_not_zero(&rb->refcount))
4881 void ring_buffer_put(struct ring_buffer *rb)
4883 if (!atomic_dec_and_test(&rb->refcount))
4886 WARN_ON_ONCE(!list_empty(&rb->event_list));
4888 call_rcu(&rb->rcu_head, rb_free_rcu);
4891 static void perf_mmap_open(struct vm_area_struct *vma)
4893 struct perf_event *event = vma->vm_file->private_data;
4895 atomic_inc(&event->mmap_count);
4896 atomic_inc(&event->rb->mmap_count);
4899 atomic_inc(&event->rb->aux_mmap_count);
4901 if (event->pmu->event_mapped)
4902 event->pmu->event_mapped(event);
4905 static void perf_pmu_output_stop(struct perf_event *event);
4908 * A buffer can be mmap()ed multiple times; either directly through the same
4909 * event, or through other events by use of perf_event_set_output().
4911 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4912 * the buffer here, where we still have a VM context. This means we need
4913 * to detach all events redirecting to us.
4915 static void perf_mmap_close(struct vm_area_struct *vma)
4917 struct perf_event *event = vma->vm_file->private_data;
4919 struct ring_buffer *rb = ring_buffer_get(event);
4920 struct user_struct *mmap_user = rb->mmap_user;
4921 int mmap_locked = rb->mmap_locked;
4922 unsigned long size = perf_data_size(rb);
4924 if (event->pmu->event_unmapped)
4925 event->pmu->event_unmapped(event);
4928 * rb->aux_mmap_count will always drop before rb->mmap_count and
4929 * event->mmap_count, so it is ok to use event->mmap_mutex to
4930 * serialize with perf_mmap here.
4932 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
4933 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
4935 * Stop all AUX events that are writing to this buffer,
4936 * so that we can free its AUX pages and corresponding PMU
4937 * data. Note that after rb::aux_mmap_count dropped to zero,
4938 * they won't start any more (see perf_aux_output_begin()).
4940 perf_pmu_output_stop(event);
4942 /* now it's safe to free the pages */
4943 atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm);
4944 vma->vm_mm->pinned_vm -= rb->aux_mmap_locked;
4946 /* this has to be the last one */
4948 WARN_ON_ONCE(atomic_read(&rb->aux_refcount));
4950 mutex_unlock(&event->mmap_mutex);
4953 atomic_dec(&rb->mmap_count);
4955 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
4958 ring_buffer_attach(event, NULL);
4959 mutex_unlock(&event->mmap_mutex);
4961 /* If there's still other mmap()s of this buffer, we're done. */
4962 if (atomic_read(&rb->mmap_count))
4966 * No other mmap()s, detach from all other events that might redirect
4967 * into the now unreachable buffer. Somewhat complicated by the
4968 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4972 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
4973 if (!atomic_long_inc_not_zero(&event->refcount)) {
4975 * This event is en-route to free_event() which will
4976 * detach it and remove it from the list.
4982 mutex_lock(&event->mmap_mutex);
4984 * Check we didn't race with perf_event_set_output() which can
4985 * swizzle the rb from under us while we were waiting to
4986 * acquire mmap_mutex.
4988 * If we find a different rb; ignore this event, a next
4989 * iteration will no longer find it on the list. We have to
4990 * still restart the iteration to make sure we're not now
4991 * iterating the wrong list.
4993 if (event->rb == rb)
4994 ring_buffer_attach(event, NULL);
4996 mutex_unlock(&event->mmap_mutex);
5000 * Restart the iteration; either we're on the wrong list or
5001 * destroyed its integrity by doing a deletion.
5008 * It could be there's still a few 0-ref events on the list; they'll
5009 * get cleaned up by free_event() -- they'll also still have their
5010 * ref on the rb and will free it whenever they are done with it.
5012 * Aside from that, this buffer is 'fully' detached and unmapped,
5013 * undo the VM accounting.
5016 atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
5017 vma->vm_mm->pinned_vm -= mmap_locked;
5018 free_uid(mmap_user);
5021 ring_buffer_put(rb); /* could be last */
5024 static const struct vm_operations_struct perf_mmap_vmops = {
5025 .open = perf_mmap_open,
5026 .close = perf_mmap_close, /* non mergable */
5027 .fault = perf_mmap_fault,
5028 .page_mkwrite = perf_mmap_fault,
5031 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
5033 struct perf_event *event = file->private_data;
5034 unsigned long user_locked, user_lock_limit;
5035 struct user_struct *user = current_user();
5036 unsigned long locked, lock_limit;
5037 struct ring_buffer *rb = NULL;
5038 unsigned long vma_size;
5039 unsigned long nr_pages;
5040 long user_extra = 0, extra = 0;
5041 int ret = 0, flags = 0;
5044 * Don't allow mmap() of inherited per-task counters. This would
5045 * create a performance issue due to all children writing to the
5048 if (event->cpu == -1 && event->attr.inherit)
5051 if (!(vma->vm_flags & VM_SHARED))
5054 vma_size = vma->vm_end - vma->vm_start;
5056 if (vma->vm_pgoff == 0) {
5057 nr_pages = (vma_size / PAGE_SIZE) - 1;
5060 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5061 * mapped, all subsequent mappings should have the same size
5062 * and offset. Must be above the normal perf buffer.
5064 u64 aux_offset, aux_size;
5069 nr_pages = vma_size / PAGE_SIZE;
5071 mutex_lock(&event->mmap_mutex);
5078 aux_offset = ACCESS_ONCE(rb->user_page->aux_offset);
5079 aux_size = ACCESS_ONCE(rb->user_page->aux_size);
5081 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
5084 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
5087 /* already mapped with a different offset */
5088 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
5091 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
5094 /* already mapped with a different size */
5095 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
5098 if (!is_power_of_2(nr_pages))
5101 if (!atomic_inc_not_zero(&rb->mmap_count))
5104 if (rb_has_aux(rb)) {
5105 atomic_inc(&rb->aux_mmap_count);
5110 atomic_set(&rb->aux_mmap_count, 1);
5111 user_extra = nr_pages;
5117 * If we have rb pages ensure they're a power-of-two number, so we
5118 * can do bitmasks instead of modulo.
5120 if (nr_pages != 0 && !is_power_of_2(nr_pages))
5123 if (vma_size != PAGE_SIZE * (1 + nr_pages))
5126 WARN_ON_ONCE(event->ctx->parent_ctx);
5128 mutex_lock(&event->mmap_mutex);
5130 if (event->rb->nr_pages != nr_pages) {
5135 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
5137 * Raced against perf_mmap_close() through
5138 * perf_event_set_output(). Try again, hope for better
5141 mutex_unlock(&event->mmap_mutex);
5148 user_extra = nr_pages + 1;
5151 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
5154 * Increase the limit linearly with more CPUs:
5156 user_lock_limit *= num_online_cpus();
5158 user_locked = atomic_long_read(&user->locked_vm) + user_extra;
5160 if (user_locked > user_lock_limit)
5161 extra = user_locked - user_lock_limit;
5163 lock_limit = rlimit(RLIMIT_MEMLOCK);
5164 lock_limit >>= PAGE_SHIFT;
5165 locked = vma->vm_mm->pinned_vm + extra;
5167 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
5168 !capable(CAP_IPC_LOCK)) {
5173 WARN_ON(!rb && event->rb);
5175 if (vma->vm_flags & VM_WRITE)
5176 flags |= RING_BUFFER_WRITABLE;
5179 rb = rb_alloc(nr_pages,
5180 event->attr.watermark ? event->attr.wakeup_watermark : 0,
5188 atomic_set(&rb->mmap_count, 1);
5189 rb->mmap_user = get_current_user();
5190 rb->mmap_locked = extra;
5192 ring_buffer_attach(event, rb);
5194 perf_event_init_userpage(event);
5195 perf_event_update_userpage(event);
5197 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
5198 event->attr.aux_watermark, flags);
5200 rb->aux_mmap_locked = extra;
5205 atomic_long_add(user_extra, &user->locked_vm);
5206 vma->vm_mm->pinned_vm += extra;
5208 atomic_inc(&event->mmap_count);
5210 atomic_dec(&rb->mmap_count);
5213 mutex_unlock(&event->mmap_mutex);
5216 * Since pinned accounting is per vm we cannot allow fork() to copy our
5219 vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
5220 vma->vm_ops = &perf_mmap_vmops;
5222 if (event->pmu->event_mapped)
5223 event->pmu->event_mapped(event);
5228 static int perf_fasync(int fd, struct file *filp, int on)
5230 struct inode *inode = file_inode(filp);
5231 struct perf_event *event = filp->private_data;
5235 retval = fasync_helper(fd, filp, on, &event->fasync);
5236 inode_unlock(inode);
5244 static const struct file_operations perf_fops = {
5245 .llseek = no_llseek,
5246 .release = perf_release,
5249 .unlocked_ioctl = perf_ioctl,
5250 .compat_ioctl = perf_compat_ioctl,
5252 .fasync = perf_fasync,
5258 * If there's data, ensure we set the poll() state and publish everything
5259 * to user-space before waking everybody up.
5262 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
5264 /* only the parent has fasync state */
5266 event = event->parent;
5267 return &event->fasync;
5270 void perf_event_wakeup(struct perf_event *event)
5272 ring_buffer_wakeup(event);
5274 if (event->pending_kill) {
5275 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
5276 event->pending_kill = 0;
5280 static void perf_pending_event(struct irq_work *entry)
5282 struct perf_event *event = container_of(entry,
5283 struct perf_event, pending);
5286 rctx = perf_swevent_get_recursion_context();
5288 * If we 'fail' here, that's OK, it means recursion is already disabled
5289 * and we won't recurse 'further'.
5292 if (event->pending_disable) {
5293 event->pending_disable = 0;
5294 perf_event_disable_local(event);
5297 if (event->pending_wakeup) {
5298 event->pending_wakeup = 0;
5299 perf_event_wakeup(event);
5303 perf_swevent_put_recursion_context(rctx);
5307 * We assume there is only KVM supporting the callbacks.
5308 * Later on, we might change it to a list if there is
5309 * another virtualization implementation supporting the callbacks.
5311 struct perf_guest_info_callbacks *perf_guest_cbs;
5313 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5315 perf_guest_cbs = cbs;
5318 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
5320 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5322 perf_guest_cbs = NULL;
5325 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
5328 perf_output_sample_regs(struct perf_output_handle *handle,
5329 struct pt_regs *regs, u64 mask)
5333 for_each_set_bit(bit, (const unsigned long *) &mask,
5334 sizeof(mask) * BITS_PER_BYTE) {
5337 val = perf_reg_value(regs, bit);
5338 perf_output_put(handle, val);
5342 static void perf_sample_regs_user(struct perf_regs *regs_user,
5343 struct pt_regs *regs,
5344 struct pt_regs *regs_user_copy)
5346 if (user_mode(regs)) {
5347 regs_user->abi = perf_reg_abi(current);
5348 regs_user->regs = regs;
5349 } else if (current->mm) {
5350 perf_get_regs_user(regs_user, regs, regs_user_copy);
5352 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
5353 regs_user->regs = NULL;
5357 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
5358 struct pt_regs *regs)
5360 regs_intr->regs = regs;
5361 regs_intr->abi = perf_reg_abi(current);
5366 * Get remaining task size from user stack pointer.
5368 * It'd be better to take stack vma map and limit this more
5369 * precisly, but there's no way to get it safely under interrupt,
5370 * so using TASK_SIZE as limit.
5372 static u64 perf_ustack_task_size(struct pt_regs *regs)
5374 unsigned long addr = perf_user_stack_pointer(regs);
5376 if (!addr || addr >= TASK_SIZE)
5379 return TASK_SIZE - addr;
5383 perf_sample_ustack_size(u16 stack_size, u16 header_size,
5384 struct pt_regs *regs)
5388 /* No regs, no stack pointer, no dump. */
5393 * Check if we fit in with the requested stack size into the:
5395 * If we don't, we limit the size to the TASK_SIZE.
5397 * - remaining sample size
5398 * If we don't, we customize the stack size to
5399 * fit in to the remaining sample size.
5402 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
5403 stack_size = min(stack_size, (u16) task_size);
5405 /* Current header size plus static size and dynamic size. */
5406 header_size += 2 * sizeof(u64);
5408 /* Do we fit in with the current stack dump size? */
5409 if ((u16) (header_size + stack_size) < header_size) {
5411 * If we overflow the maximum size for the sample,
5412 * we customize the stack dump size to fit in.
5414 stack_size = USHRT_MAX - header_size - sizeof(u64);
5415 stack_size = round_up(stack_size, sizeof(u64));
5422 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
5423 struct pt_regs *regs)
5425 /* Case of a kernel thread, nothing to dump */
5428 perf_output_put(handle, size);
5437 * - the size requested by user or the best one we can fit
5438 * in to the sample max size
5440 * - user stack dump data
5442 * - the actual dumped size
5446 perf_output_put(handle, dump_size);
5449 sp = perf_user_stack_pointer(regs);
5450 rem = __output_copy_user(handle, (void *) sp, dump_size);
5451 dyn_size = dump_size - rem;
5453 perf_output_skip(handle, rem);
5456 perf_output_put(handle, dyn_size);
5460 static void __perf_event_header__init_id(struct perf_event_header *header,
5461 struct perf_sample_data *data,
5462 struct perf_event *event)
5464 u64 sample_type = event->attr.sample_type;
5466 data->type = sample_type;
5467 header->size += event->id_header_size;
5469 if (sample_type & PERF_SAMPLE_TID) {
5470 /* namespace issues */
5471 data->tid_entry.pid = perf_event_pid(event, current);
5472 data->tid_entry.tid = perf_event_tid(event, current);
5475 if (sample_type & PERF_SAMPLE_TIME)
5476 data->time = perf_event_clock(event);
5478 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
5479 data->id = primary_event_id(event);
5481 if (sample_type & PERF_SAMPLE_STREAM_ID)
5482 data->stream_id = event->id;
5484 if (sample_type & PERF_SAMPLE_CPU) {
5485 data->cpu_entry.cpu = raw_smp_processor_id();
5486 data->cpu_entry.reserved = 0;
5490 void perf_event_header__init_id(struct perf_event_header *header,
5491 struct perf_sample_data *data,
5492 struct perf_event *event)
5494 if (event->attr.sample_id_all)
5495 __perf_event_header__init_id(header, data, event);
5498 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
5499 struct perf_sample_data *data)
5501 u64 sample_type = data->type;
5503 if (sample_type & PERF_SAMPLE_TID)
5504 perf_output_put(handle, data->tid_entry);
5506 if (sample_type & PERF_SAMPLE_TIME)
5507 perf_output_put(handle, data->time);
5509 if (sample_type & PERF_SAMPLE_ID)
5510 perf_output_put(handle, data->id);
5512 if (sample_type & PERF_SAMPLE_STREAM_ID)
5513 perf_output_put(handle, data->stream_id);
5515 if (sample_type & PERF_SAMPLE_CPU)
5516 perf_output_put(handle, data->cpu_entry);
5518 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5519 perf_output_put(handle, data->id);
5522 void perf_event__output_id_sample(struct perf_event *event,
5523 struct perf_output_handle *handle,
5524 struct perf_sample_data *sample)
5526 if (event->attr.sample_id_all)
5527 __perf_event__output_id_sample(handle, sample);
5530 static void perf_output_read_one(struct perf_output_handle *handle,
5531 struct perf_event *event,
5532 u64 enabled, u64 running)
5534 u64 read_format = event->attr.read_format;
5538 values[n++] = perf_event_count(event);
5539 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5540 values[n++] = enabled +
5541 atomic64_read(&event->child_total_time_enabled);
5543 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5544 values[n++] = running +
5545 atomic64_read(&event->child_total_time_running);
5547 if (read_format & PERF_FORMAT_ID)
5548 values[n++] = primary_event_id(event);
5550 __output_copy(handle, values, n * sizeof(u64));
5554 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5556 static void perf_output_read_group(struct perf_output_handle *handle,
5557 struct perf_event *event,
5558 u64 enabled, u64 running)
5560 struct perf_event *leader = event->group_leader, *sub;
5561 u64 read_format = event->attr.read_format;
5565 values[n++] = 1 + leader->nr_siblings;
5567 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5568 values[n++] = enabled;
5570 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5571 values[n++] = running;
5573 if (leader != event)
5574 leader->pmu->read(leader);
5576 values[n++] = perf_event_count(leader);
5577 if (read_format & PERF_FORMAT_ID)
5578 values[n++] = primary_event_id(leader);
5580 __output_copy(handle, values, n * sizeof(u64));
5582 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
5585 if ((sub != event) &&
5586 (sub->state == PERF_EVENT_STATE_ACTIVE))
5587 sub->pmu->read(sub);
5589 values[n++] = perf_event_count(sub);
5590 if (read_format & PERF_FORMAT_ID)
5591 values[n++] = primary_event_id(sub);
5593 __output_copy(handle, values, n * sizeof(u64));
5597 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5598 PERF_FORMAT_TOTAL_TIME_RUNNING)
5600 static void perf_output_read(struct perf_output_handle *handle,
5601 struct perf_event *event)
5603 u64 enabled = 0, running = 0, now;
5604 u64 read_format = event->attr.read_format;
5607 * compute total_time_enabled, total_time_running
5608 * based on snapshot values taken when the event
5609 * was last scheduled in.
5611 * we cannot simply called update_context_time()
5612 * because of locking issue as we are called in
5615 if (read_format & PERF_FORMAT_TOTAL_TIMES)
5616 calc_timer_values(event, &now, &enabled, &running);
5618 if (event->attr.read_format & PERF_FORMAT_GROUP)
5619 perf_output_read_group(handle, event, enabled, running);
5621 perf_output_read_one(handle, event, enabled, running);
5624 void perf_output_sample(struct perf_output_handle *handle,
5625 struct perf_event_header *header,
5626 struct perf_sample_data *data,
5627 struct perf_event *event)
5629 u64 sample_type = data->type;
5631 perf_output_put(handle, *header);
5633 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5634 perf_output_put(handle, data->id);
5636 if (sample_type & PERF_SAMPLE_IP)
5637 perf_output_put(handle, data->ip);
5639 if (sample_type & PERF_SAMPLE_TID)
5640 perf_output_put(handle, data->tid_entry);
5642 if (sample_type & PERF_SAMPLE_TIME)
5643 perf_output_put(handle, data->time);
5645 if (sample_type & PERF_SAMPLE_ADDR)
5646 perf_output_put(handle, data->addr);
5648 if (sample_type & PERF_SAMPLE_ID)
5649 perf_output_put(handle, data->id);
5651 if (sample_type & PERF_SAMPLE_STREAM_ID)
5652 perf_output_put(handle, data->stream_id);
5654 if (sample_type & PERF_SAMPLE_CPU)
5655 perf_output_put(handle, data->cpu_entry);
5657 if (sample_type & PERF_SAMPLE_PERIOD)
5658 perf_output_put(handle, data->period);
5660 if (sample_type & PERF_SAMPLE_READ)
5661 perf_output_read(handle, event);
5663 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5664 if (data->callchain) {
5667 if (data->callchain)
5668 size += data->callchain->nr;
5670 size *= sizeof(u64);
5672 __output_copy(handle, data->callchain, size);
5675 perf_output_put(handle, nr);
5679 if (sample_type & PERF_SAMPLE_RAW) {
5680 struct perf_raw_record *raw = data->raw;
5683 struct perf_raw_frag *frag = &raw->frag;
5685 perf_output_put(handle, raw->size);
5688 __output_custom(handle, frag->copy,
5689 frag->data, frag->size);
5691 __output_copy(handle, frag->data,
5694 if (perf_raw_frag_last(frag))
5699 __output_skip(handle, NULL, frag->pad);
5705 .size = sizeof(u32),
5708 perf_output_put(handle, raw);
5712 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5713 if (data->br_stack) {
5716 size = data->br_stack->nr
5717 * sizeof(struct perf_branch_entry);
5719 perf_output_put(handle, data->br_stack->nr);
5720 perf_output_copy(handle, data->br_stack->entries, size);
5723 * we always store at least the value of nr
5726 perf_output_put(handle, nr);
5730 if (sample_type & PERF_SAMPLE_REGS_USER) {
5731 u64 abi = data->regs_user.abi;
5734 * If there are no regs to dump, notice it through
5735 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5737 perf_output_put(handle, abi);
5740 u64 mask = event->attr.sample_regs_user;
5741 perf_output_sample_regs(handle,
5742 data->regs_user.regs,
5747 if (sample_type & PERF_SAMPLE_STACK_USER) {
5748 perf_output_sample_ustack(handle,
5749 data->stack_user_size,
5750 data->regs_user.regs);
5753 if (sample_type & PERF_SAMPLE_WEIGHT)
5754 perf_output_put(handle, data->weight);
5756 if (sample_type & PERF_SAMPLE_DATA_SRC)
5757 perf_output_put(handle, data->data_src.val);
5759 if (sample_type & PERF_SAMPLE_TRANSACTION)
5760 perf_output_put(handle, data->txn);
5762 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5763 u64 abi = data->regs_intr.abi;
5765 * If there are no regs to dump, notice it through
5766 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5768 perf_output_put(handle, abi);
5771 u64 mask = event->attr.sample_regs_intr;
5773 perf_output_sample_regs(handle,
5774 data->regs_intr.regs,
5779 if (!event->attr.watermark) {
5780 int wakeup_events = event->attr.wakeup_events;
5782 if (wakeup_events) {
5783 struct ring_buffer *rb = handle->rb;
5784 int events = local_inc_return(&rb->events);
5786 if (events >= wakeup_events) {
5787 local_sub(wakeup_events, &rb->events);
5788 local_inc(&rb->wakeup);
5794 void perf_prepare_sample(struct perf_event_header *header,
5795 struct perf_sample_data *data,
5796 struct perf_event *event,
5797 struct pt_regs *regs)
5799 u64 sample_type = event->attr.sample_type;
5801 header->type = PERF_RECORD_SAMPLE;
5802 header->size = sizeof(*header) + event->header_size;
5805 header->misc |= perf_misc_flags(regs);
5807 __perf_event_header__init_id(header, data, event);
5809 if (sample_type & PERF_SAMPLE_IP)
5810 data->ip = perf_instruction_pointer(regs);
5812 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5815 data->callchain = perf_callchain(event, regs);
5817 if (data->callchain)
5818 size += data->callchain->nr;
5820 header->size += size * sizeof(u64);
5823 if (sample_type & PERF_SAMPLE_RAW) {
5824 struct perf_raw_record *raw = data->raw;
5828 struct perf_raw_frag *frag = &raw->frag;
5833 if (perf_raw_frag_last(frag))
5838 size = round_up(sum + sizeof(u32), sizeof(u64));
5839 raw->size = size - sizeof(u32);
5840 frag->pad = raw->size - sum;
5845 header->size += size;
5848 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5849 int size = sizeof(u64); /* nr */
5850 if (data->br_stack) {
5851 size += data->br_stack->nr
5852 * sizeof(struct perf_branch_entry);
5854 header->size += size;
5857 if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
5858 perf_sample_regs_user(&data->regs_user, regs,
5859 &data->regs_user_copy);
5861 if (sample_type & PERF_SAMPLE_REGS_USER) {
5862 /* regs dump ABI info */
5863 int size = sizeof(u64);
5865 if (data->regs_user.regs) {
5866 u64 mask = event->attr.sample_regs_user;
5867 size += hweight64(mask) * sizeof(u64);
5870 header->size += size;
5873 if (sample_type & PERF_SAMPLE_STACK_USER) {
5875 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5876 * processed as the last one or have additional check added
5877 * in case new sample type is added, because we could eat
5878 * up the rest of the sample size.
5880 u16 stack_size = event->attr.sample_stack_user;
5881 u16 size = sizeof(u64);
5883 stack_size = perf_sample_ustack_size(stack_size, header->size,
5884 data->regs_user.regs);
5887 * If there is something to dump, add space for the dump
5888 * itself and for the field that tells the dynamic size,
5889 * which is how many have been actually dumped.
5892 size += sizeof(u64) + stack_size;
5894 data->stack_user_size = stack_size;
5895 header->size += size;
5898 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5899 /* regs dump ABI info */
5900 int size = sizeof(u64);
5902 perf_sample_regs_intr(&data->regs_intr, regs);
5904 if (data->regs_intr.regs) {
5905 u64 mask = event->attr.sample_regs_intr;
5907 size += hweight64(mask) * sizeof(u64);
5910 header->size += size;
5914 static void __always_inline
5915 __perf_event_output(struct perf_event *event,
5916 struct perf_sample_data *data,
5917 struct pt_regs *regs,
5918 int (*output_begin)(struct perf_output_handle *,
5919 struct perf_event *,
5922 struct perf_output_handle handle;
5923 struct perf_event_header header;
5925 /* protect the callchain buffers */
5928 perf_prepare_sample(&header, data, event, regs);
5930 if (output_begin(&handle, event, header.size))
5933 perf_output_sample(&handle, &header, data, event);
5935 perf_output_end(&handle);
5942 perf_event_output_forward(struct perf_event *event,
5943 struct perf_sample_data *data,
5944 struct pt_regs *regs)
5946 __perf_event_output(event, data, regs, perf_output_begin_forward);
5950 perf_event_output_backward(struct perf_event *event,
5951 struct perf_sample_data *data,
5952 struct pt_regs *regs)
5954 __perf_event_output(event, data, regs, perf_output_begin_backward);
5958 perf_event_output(struct perf_event *event,
5959 struct perf_sample_data *data,
5960 struct pt_regs *regs)
5962 __perf_event_output(event, data, regs, perf_output_begin);
5969 struct perf_read_event {
5970 struct perf_event_header header;
5977 perf_event_read_event(struct perf_event *event,
5978 struct task_struct *task)
5980 struct perf_output_handle handle;
5981 struct perf_sample_data sample;
5982 struct perf_read_event read_event = {
5984 .type = PERF_RECORD_READ,
5986 .size = sizeof(read_event) + event->read_size,
5988 .pid = perf_event_pid(event, task),
5989 .tid = perf_event_tid(event, task),
5993 perf_event_header__init_id(&read_event.header, &sample, event);
5994 ret = perf_output_begin(&handle, event, read_event.header.size);
5998 perf_output_put(&handle, read_event);
5999 perf_output_read(&handle, event);
6000 perf_event__output_id_sample(event, &handle, &sample);
6002 perf_output_end(&handle);
6005 typedef void (perf_iterate_f)(struct perf_event *event, void *data);
6008 perf_iterate_ctx(struct perf_event_context *ctx,
6009 perf_iterate_f output,
6010 void *data, bool all)
6012 struct perf_event *event;
6014 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
6016 if (event->state < PERF_EVENT_STATE_INACTIVE)
6018 if (!event_filter_match(event))
6022 output(event, data);
6026 static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
6028 struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
6029 struct perf_event *event;
6031 list_for_each_entry_rcu(event, &pel->list, sb_list) {
6033 * Skip events that are not fully formed yet; ensure that
6034 * if we observe event->ctx, both event and ctx will be
6035 * complete enough. See perf_install_in_context().
6037 if (!smp_load_acquire(&event->ctx))
6040 if (event->state < PERF_EVENT_STATE_INACTIVE)
6042 if (!event_filter_match(event))
6044 output(event, data);
6049 * Iterate all events that need to receive side-band events.
6051 * For new callers; ensure that account_pmu_sb_event() includes
6052 * your event, otherwise it might not get delivered.
6055 perf_iterate_sb(perf_iterate_f output, void *data,
6056 struct perf_event_context *task_ctx)
6058 struct perf_event_context *ctx;
6065 * If we have task_ctx != NULL we only notify the task context itself.
6066 * The task_ctx is set only for EXIT events before releasing task
6070 perf_iterate_ctx(task_ctx, output, data, false);
6074 perf_iterate_sb_cpu(output, data);
6076 for_each_task_context_nr(ctxn) {
6077 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6079 perf_iterate_ctx(ctx, output, data, false);
6087 * Clear all file-based filters at exec, they'll have to be
6088 * re-instated when/if these objects are mmapped again.
6090 static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
6092 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6093 struct perf_addr_filter *filter;
6094 unsigned int restart = 0, count = 0;
6095 unsigned long flags;
6097 if (!has_addr_filter(event))
6100 raw_spin_lock_irqsave(&ifh->lock, flags);
6101 list_for_each_entry(filter, &ifh->list, entry) {
6102 if (filter->inode) {
6103 event->addr_filters_offs[count] = 0;
6111 event->addr_filters_gen++;
6112 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6115 perf_event_restart(event);
6118 void perf_event_exec(void)
6120 struct perf_event_context *ctx;
6124 for_each_task_context_nr(ctxn) {
6125 ctx = current->perf_event_ctxp[ctxn];
6129 perf_event_enable_on_exec(ctxn);
6131 perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL,
6137 struct remote_output {
6138 struct ring_buffer *rb;
6142 static void __perf_event_output_stop(struct perf_event *event, void *data)
6144 struct perf_event *parent = event->parent;
6145 struct remote_output *ro = data;
6146 struct ring_buffer *rb = ro->rb;
6147 struct stop_event_data sd = {
6151 if (!has_aux(event))
6158 * In case of inheritance, it will be the parent that links to the
6159 * ring-buffer, but it will be the child that's actually using it:
6161 if (rcu_dereference(parent->rb) == rb)
6162 ro->err = __perf_event_stop(&sd);
6165 static int __perf_pmu_output_stop(void *info)
6167 struct perf_event *event = info;
6168 struct pmu *pmu = event->pmu;
6169 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
6170 struct remote_output ro = {
6175 perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
6176 if (cpuctx->task_ctx)
6177 perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
6184 static void perf_pmu_output_stop(struct perf_event *event)
6186 struct perf_event *iter;
6191 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
6193 * For per-CPU events, we need to make sure that neither they
6194 * nor their children are running; for cpu==-1 events it's
6195 * sufficient to stop the event itself if it's active, since
6196 * it can't have children.
6200 cpu = READ_ONCE(iter->oncpu);
6205 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
6206 if (err == -EAGAIN) {
6215 * task tracking -- fork/exit
6217 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6220 struct perf_task_event {
6221 struct task_struct *task;
6222 struct perf_event_context *task_ctx;
6225 struct perf_event_header header;
6235 static int perf_event_task_match(struct perf_event *event)
6237 return event->attr.comm || event->attr.mmap ||
6238 event->attr.mmap2 || event->attr.mmap_data ||
6242 static void perf_event_task_output(struct perf_event *event,
6245 struct perf_task_event *task_event = data;
6246 struct perf_output_handle handle;
6247 struct perf_sample_data sample;
6248 struct task_struct *task = task_event->task;
6249 int ret, size = task_event->event_id.header.size;
6251 if (!perf_event_task_match(event))
6254 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
6256 ret = perf_output_begin(&handle, event,
6257 task_event->event_id.header.size);
6261 task_event->event_id.pid = perf_event_pid(event, task);
6262 task_event->event_id.ppid = perf_event_pid(event, current);
6264 task_event->event_id.tid = perf_event_tid(event, task);
6265 task_event->event_id.ptid = perf_event_tid(event, current);
6267 task_event->event_id.time = perf_event_clock(event);
6269 perf_output_put(&handle, task_event->event_id);
6271 perf_event__output_id_sample(event, &handle, &sample);
6273 perf_output_end(&handle);
6275 task_event->event_id.header.size = size;
6278 static void perf_event_task(struct task_struct *task,
6279 struct perf_event_context *task_ctx,
6282 struct perf_task_event task_event;
6284 if (!atomic_read(&nr_comm_events) &&
6285 !atomic_read(&nr_mmap_events) &&
6286 !atomic_read(&nr_task_events))
6289 task_event = (struct perf_task_event){
6291 .task_ctx = task_ctx,
6294 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
6296 .size = sizeof(task_event.event_id),
6306 perf_iterate_sb(perf_event_task_output,
6311 void perf_event_fork(struct task_struct *task)
6313 perf_event_task(task, NULL, 1);
6320 struct perf_comm_event {
6321 struct task_struct *task;
6326 struct perf_event_header header;
6333 static int perf_event_comm_match(struct perf_event *event)
6335 return event->attr.comm;
6338 static void perf_event_comm_output(struct perf_event *event,
6341 struct perf_comm_event *comm_event = data;
6342 struct perf_output_handle handle;
6343 struct perf_sample_data sample;
6344 int size = comm_event->event_id.header.size;
6347 if (!perf_event_comm_match(event))
6350 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
6351 ret = perf_output_begin(&handle, event,
6352 comm_event->event_id.header.size);
6357 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
6358 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
6360 perf_output_put(&handle, comm_event->event_id);
6361 __output_copy(&handle, comm_event->comm,
6362 comm_event->comm_size);
6364 perf_event__output_id_sample(event, &handle, &sample);
6366 perf_output_end(&handle);
6368 comm_event->event_id.header.size = size;
6371 static void perf_event_comm_event(struct perf_comm_event *comm_event)
6373 char comm[TASK_COMM_LEN];
6376 memset(comm, 0, sizeof(comm));
6377 strlcpy(comm, comm_event->task->comm, sizeof(comm));
6378 size = ALIGN(strlen(comm)+1, sizeof(u64));
6380 comm_event->comm = comm;
6381 comm_event->comm_size = size;
6383 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
6385 perf_iterate_sb(perf_event_comm_output,
6390 void perf_event_comm(struct task_struct *task, bool exec)
6392 struct perf_comm_event comm_event;
6394 if (!atomic_read(&nr_comm_events))
6397 comm_event = (struct perf_comm_event){
6403 .type = PERF_RECORD_COMM,
6404 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
6412 perf_event_comm_event(&comm_event);
6419 struct perf_mmap_event {
6420 struct vm_area_struct *vma;
6422 const char *file_name;
6430 struct perf_event_header header;
6440 static int perf_event_mmap_match(struct perf_event *event,
6443 struct perf_mmap_event *mmap_event = data;
6444 struct vm_area_struct *vma = mmap_event->vma;
6445 int executable = vma->vm_flags & VM_EXEC;
6447 return (!executable && event->attr.mmap_data) ||
6448 (executable && (event->attr.mmap || event->attr.mmap2));
6451 static void perf_event_mmap_output(struct perf_event *event,
6454 struct perf_mmap_event *mmap_event = data;
6455 struct perf_output_handle handle;
6456 struct perf_sample_data sample;
6457 int size = mmap_event->event_id.header.size;
6460 if (!perf_event_mmap_match(event, data))
6463 if (event->attr.mmap2) {
6464 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
6465 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
6466 mmap_event->event_id.header.size += sizeof(mmap_event->min);
6467 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
6468 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
6469 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
6470 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
6473 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
6474 ret = perf_output_begin(&handle, event,
6475 mmap_event->event_id.header.size);
6479 mmap_event->event_id.pid = perf_event_pid(event, current);
6480 mmap_event->event_id.tid = perf_event_tid(event, current);
6482 perf_output_put(&handle, mmap_event->event_id);
6484 if (event->attr.mmap2) {
6485 perf_output_put(&handle, mmap_event->maj);
6486 perf_output_put(&handle, mmap_event->min);
6487 perf_output_put(&handle, mmap_event->ino);
6488 perf_output_put(&handle, mmap_event->ino_generation);
6489 perf_output_put(&handle, mmap_event->prot);
6490 perf_output_put(&handle, mmap_event->flags);
6493 __output_copy(&handle, mmap_event->file_name,
6494 mmap_event->file_size);
6496 perf_event__output_id_sample(event, &handle, &sample);
6498 perf_output_end(&handle);
6500 mmap_event->event_id.header.size = size;
6503 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
6505 struct vm_area_struct *vma = mmap_event->vma;
6506 struct file *file = vma->vm_file;
6507 int maj = 0, min = 0;
6508 u64 ino = 0, gen = 0;
6509 u32 prot = 0, flags = 0;
6516 struct inode *inode;
6519 buf = kmalloc(PATH_MAX, GFP_KERNEL);
6525 * d_path() works from the end of the rb backwards, so we
6526 * need to add enough zero bytes after the string to handle
6527 * the 64bit alignment we do later.
6529 name = file_path(file, buf, PATH_MAX - sizeof(u64));
6534 inode = file_inode(vma->vm_file);
6535 dev = inode->i_sb->s_dev;
6537 gen = inode->i_generation;
6541 if (vma->vm_flags & VM_READ)
6543 if (vma->vm_flags & VM_WRITE)
6545 if (vma->vm_flags & VM_EXEC)
6548 if (vma->vm_flags & VM_MAYSHARE)
6551 flags = MAP_PRIVATE;
6553 if (vma->vm_flags & VM_DENYWRITE)
6554 flags |= MAP_DENYWRITE;
6555 if (vma->vm_flags & VM_MAYEXEC)
6556 flags |= MAP_EXECUTABLE;
6557 if (vma->vm_flags & VM_LOCKED)
6558 flags |= MAP_LOCKED;
6559 if (vma->vm_flags & VM_HUGETLB)
6560 flags |= MAP_HUGETLB;
6564 if (vma->vm_ops && vma->vm_ops->name) {
6565 name = (char *) vma->vm_ops->name(vma);
6570 name = (char *)arch_vma_name(vma);
6574 if (vma->vm_start <= vma->vm_mm->start_brk &&
6575 vma->vm_end >= vma->vm_mm->brk) {
6579 if (vma->vm_start <= vma->vm_mm->start_stack &&
6580 vma->vm_end >= vma->vm_mm->start_stack) {
6590 strlcpy(tmp, name, sizeof(tmp));
6594 * Since our buffer works in 8 byte units we need to align our string
6595 * size to a multiple of 8. However, we must guarantee the tail end is
6596 * zero'd out to avoid leaking random bits to userspace.
6598 size = strlen(name)+1;
6599 while (!IS_ALIGNED(size, sizeof(u64)))
6600 name[size++] = '\0';
6602 mmap_event->file_name = name;
6603 mmap_event->file_size = size;
6604 mmap_event->maj = maj;
6605 mmap_event->min = min;
6606 mmap_event->ino = ino;
6607 mmap_event->ino_generation = gen;
6608 mmap_event->prot = prot;
6609 mmap_event->flags = flags;
6611 if (!(vma->vm_flags & VM_EXEC))
6612 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
6614 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
6616 perf_iterate_sb(perf_event_mmap_output,
6624 * Check whether inode and address range match filter criteria.
6626 static bool perf_addr_filter_match(struct perf_addr_filter *filter,
6627 struct file *file, unsigned long offset,
6630 if (filter->inode != file->f_inode)
6633 if (filter->offset > offset + size)
6636 if (filter->offset + filter->size < offset)
6642 static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
6644 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6645 struct vm_area_struct *vma = data;
6646 unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags;
6647 struct file *file = vma->vm_file;
6648 struct perf_addr_filter *filter;
6649 unsigned int restart = 0, count = 0;
6651 if (!has_addr_filter(event))
6657 raw_spin_lock_irqsave(&ifh->lock, flags);
6658 list_for_each_entry(filter, &ifh->list, entry) {
6659 if (perf_addr_filter_match(filter, file, off,
6660 vma->vm_end - vma->vm_start)) {
6661 event->addr_filters_offs[count] = vma->vm_start;
6669 event->addr_filters_gen++;
6670 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6673 perf_event_restart(event);
6677 * Adjust all task's events' filters to the new vma
6679 static void perf_addr_filters_adjust(struct vm_area_struct *vma)
6681 struct perf_event_context *ctx;
6685 * Data tracing isn't supported yet and as such there is no need
6686 * to keep track of anything that isn't related to executable code:
6688 if (!(vma->vm_flags & VM_EXEC))
6692 for_each_task_context_nr(ctxn) {
6693 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6697 perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
6702 void perf_event_mmap(struct vm_area_struct *vma)
6704 struct perf_mmap_event mmap_event;
6706 if (!atomic_read(&nr_mmap_events))
6709 mmap_event = (struct perf_mmap_event){
6715 .type = PERF_RECORD_MMAP,
6716 .misc = PERF_RECORD_MISC_USER,
6721 .start = vma->vm_start,
6722 .len = vma->vm_end - vma->vm_start,
6723 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
6725 /* .maj (attr_mmap2 only) */
6726 /* .min (attr_mmap2 only) */
6727 /* .ino (attr_mmap2 only) */
6728 /* .ino_generation (attr_mmap2 only) */
6729 /* .prot (attr_mmap2 only) */
6730 /* .flags (attr_mmap2 only) */
6733 perf_addr_filters_adjust(vma);
6734 perf_event_mmap_event(&mmap_event);
6737 void perf_event_aux_event(struct perf_event *event, unsigned long head,
6738 unsigned long size, u64 flags)
6740 struct perf_output_handle handle;
6741 struct perf_sample_data sample;
6742 struct perf_aux_event {
6743 struct perf_event_header header;
6749 .type = PERF_RECORD_AUX,
6751 .size = sizeof(rec),
6759 perf_event_header__init_id(&rec.header, &sample, event);
6760 ret = perf_output_begin(&handle, event, rec.header.size);
6765 perf_output_put(&handle, rec);
6766 perf_event__output_id_sample(event, &handle, &sample);
6768 perf_output_end(&handle);
6772 * Lost/dropped samples logging
6774 void perf_log_lost_samples(struct perf_event *event, u64 lost)
6776 struct perf_output_handle handle;
6777 struct perf_sample_data sample;
6781 struct perf_event_header header;
6783 } lost_samples_event = {
6785 .type = PERF_RECORD_LOST_SAMPLES,
6787 .size = sizeof(lost_samples_event),
6792 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
6794 ret = perf_output_begin(&handle, event,
6795 lost_samples_event.header.size);
6799 perf_output_put(&handle, lost_samples_event);
6800 perf_event__output_id_sample(event, &handle, &sample);
6801 perf_output_end(&handle);
6805 * context_switch tracking
6808 struct perf_switch_event {
6809 struct task_struct *task;
6810 struct task_struct *next_prev;
6813 struct perf_event_header header;
6819 static int perf_event_switch_match(struct perf_event *event)
6821 return event->attr.context_switch;
6824 static void perf_event_switch_output(struct perf_event *event, void *data)
6826 struct perf_switch_event *se = data;
6827 struct perf_output_handle handle;
6828 struct perf_sample_data sample;
6831 if (!perf_event_switch_match(event))
6834 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6835 if (event->ctx->task) {
6836 se->event_id.header.type = PERF_RECORD_SWITCH;
6837 se->event_id.header.size = sizeof(se->event_id.header);
6839 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
6840 se->event_id.header.size = sizeof(se->event_id);
6841 se->event_id.next_prev_pid =
6842 perf_event_pid(event, se->next_prev);
6843 se->event_id.next_prev_tid =
6844 perf_event_tid(event, se->next_prev);
6847 perf_event_header__init_id(&se->event_id.header, &sample, event);
6849 ret = perf_output_begin(&handle, event, se->event_id.header.size);
6853 if (event->ctx->task)
6854 perf_output_put(&handle, se->event_id.header);
6856 perf_output_put(&handle, se->event_id);
6858 perf_event__output_id_sample(event, &handle, &sample);
6860 perf_output_end(&handle);
6863 static void perf_event_switch(struct task_struct *task,
6864 struct task_struct *next_prev, bool sched_in)
6866 struct perf_switch_event switch_event;
6868 /* N.B. caller checks nr_switch_events != 0 */
6870 switch_event = (struct perf_switch_event){
6872 .next_prev = next_prev,
6876 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
6879 /* .next_prev_pid */
6880 /* .next_prev_tid */
6884 perf_iterate_sb(perf_event_switch_output,
6890 * IRQ throttle logging
6893 static void perf_log_throttle(struct perf_event *event, int enable)
6895 struct perf_output_handle handle;
6896 struct perf_sample_data sample;
6900 struct perf_event_header header;
6904 } throttle_event = {
6906 .type = PERF_RECORD_THROTTLE,
6908 .size = sizeof(throttle_event),
6910 .time = perf_event_clock(event),
6911 .id = primary_event_id(event),
6912 .stream_id = event->id,
6916 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
6918 perf_event_header__init_id(&throttle_event.header, &sample, event);
6920 ret = perf_output_begin(&handle, event,
6921 throttle_event.header.size);
6925 perf_output_put(&handle, throttle_event);
6926 perf_event__output_id_sample(event, &handle, &sample);
6927 perf_output_end(&handle);
6930 static void perf_log_itrace_start(struct perf_event *event)
6932 struct perf_output_handle handle;
6933 struct perf_sample_data sample;
6934 struct perf_aux_event {
6935 struct perf_event_header header;
6942 event = event->parent;
6944 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
6945 event->hw.itrace_started)
6948 rec.header.type = PERF_RECORD_ITRACE_START;
6949 rec.header.misc = 0;
6950 rec.header.size = sizeof(rec);
6951 rec.pid = perf_event_pid(event, current);
6952 rec.tid = perf_event_tid(event, current);
6954 perf_event_header__init_id(&rec.header, &sample, event);
6955 ret = perf_output_begin(&handle, event, rec.header.size);
6960 perf_output_put(&handle, rec);
6961 perf_event__output_id_sample(event, &handle, &sample);
6963 perf_output_end(&handle);
6967 * Generic event overflow handling, sampling.
6970 static int __perf_event_overflow(struct perf_event *event,
6971 int throttle, struct perf_sample_data *data,
6972 struct pt_regs *regs)
6974 int events = atomic_read(&event->event_limit);
6975 struct hw_perf_event *hwc = &event->hw;
6980 * Non-sampling counters might still use the PMI to fold short
6981 * hardware counters, ignore those.
6983 if (unlikely(!is_sampling_event(event)))
6986 seq = __this_cpu_read(perf_throttled_seq);
6987 if (seq != hwc->interrupts_seq) {
6988 hwc->interrupts_seq = seq;
6989 hwc->interrupts = 1;
6992 if (unlikely(throttle
6993 && hwc->interrupts >= max_samples_per_tick)) {
6994 __this_cpu_inc(perf_throttled_count);
6995 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
6996 hwc->interrupts = MAX_INTERRUPTS;
6997 perf_log_throttle(event, 0);
7002 if (event->attr.freq) {
7003 u64 now = perf_clock();
7004 s64 delta = now - hwc->freq_time_stamp;
7006 hwc->freq_time_stamp = now;
7008 if (delta > 0 && delta < 2*TICK_NSEC)
7009 perf_adjust_period(event, delta, hwc->last_period, true);
7013 * XXX event_limit might not quite work as expected on inherited
7017 event->pending_kill = POLL_IN;
7018 if (events && atomic_dec_and_test(&event->event_limit)) {
7020 event->pending_kill = POLL_HUP;
7021 event->pending_disable = 1;
7022 irq_work_queue(&event->pending);
7025 event->overflow_handler(event, data, regs);
7027 if (*perf_event_fasync(event) && event->pending_kill) {
7028 event->pending_wakeup = 1;
7029 irq_work_queue(&event->pending);
7035 int perf_event_overflow(struct perf_event *event,
7036 struct perf_sample_data *data,
7037 struct pt_regs *regs)
7039 return __perf_event_overflow(event, 1, data, regs);
7043 * Generic software event infrastructure
7046 struct swevent_htable {
7047 struct swevent_hlist *swevent_hlist;
7048 struct mutex hlist_mutex;
7051 /* Recursion avoidance in each contexts */
7052 int recursion[PERF_NR_CONTEXTS];
7055 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
7058 * We directly increment event->count and keep a second value in
7059 * event->hw.period_left to count intervals. This period event
7060 * is kept in the range [-sample_period, 0] so that we can use the
7064 u64 perf_swevent_set_period(struct perf_event *event)
7066 struct hw_perf_event *hwc = &event->hw;
7067 u64 period = hwc->last_period;
7071 hwc->last_period = hwc->sample_period;
7074 old = val = local64_read(&hwc->period_left);
7078 nr = div64_u64(period + val, period);
7079 offset = nr * period;
7081 if (local64_cmpxchg(&hwc->period_left, old, val) != old)
7087 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
7088 struct perf_sample_data *data,
7089 struct pt_regs *regs)
7091 struct hw_perf_event *hwc = &event->hw;
7095 overflow = perf_swevent_set_period(event);
7097 if (hwc->interrupts == MAX_INTERRUPTS)
7100 for (; overflow; overflow--) {
7101 if (__perf_event_overflow(event, throttle,
7104 * We inhibit the overflow from happening when
7105 * hwc->interrupts == MAX_INTERRUPTS.
7113 static void perf_swevent_event(struct perf_event *event, u64 nr,
7114 struct perf_sample_data *data,
7115 struct pt_regs *regs)
7117 struct hw_perf_event *hwc = &event->hw;
7119 local64_add(nr, &event->count);
7124 if (!is_sampling_event(event))
7127 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
7129 return perf_swevent_overflow(event, 1, data, regs);
7131 data->period = event->hw.last_period;
7133 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
7134 return perf_swevent_overflow(event, 1, data, regs);
7136 if (local64_add_negative(nr, &hwc->period_left))
7139 perf_swevent_overflow(event, 0, data, regs);
7142 static int perf_exclude_event(struct perf_event *event,
7143 struct pt_regs *regs)
7145 if (event->hw.state & PERF_HES_STOPPED)
7149 if (event->attr.exclude_user && user_mode(regs))
7152 if (event->attr.exclude_kernel && !user_mode(regs))
7159 static int perf_swevent_match(struct perf_event *event,
7160 enum perf_type_id type,
7162 struct perf_sample_data *data,
7163 struct pt_regs *regs)
7165 if (event->attr.type != type)
7168 if (event->attr.config != event_id)
7171 if (perf_exclude_event(event, regs))
7177 static inline u64 swevent_hash(u64 type, u32 event_id)
7179 u64 val = event_id | (type << 32);
7181 return hash_64(val, SWEVENT_HLIST_BITS);
7184 static inline struct hlist_head *
7185 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
7187 u64 hash = swevent_hash(type, event_id);
7189 return &hlist->heads[hash];
7192 /* For the read side: events when they trigger */
7193 static inline struct hlist_head *
7194 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
7196 struct swevent_hlist *hlist;
7198 hlist = rcu_dereference(swhash->swevent_hlist);
7202 return __find_swevent_head(hlist, type, event_id);
7205 /* For the event head insertion and removal in the hlist */
7206 static inline struct hlist_head *
7207 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
7209 struct swevent_hlist *hlist;
7210 u32 event_id = event->attr.config;
7211 u64 type = event->attr.type;
7214 * Event scheduling is always serialized against hlist allocation
7215 * and release. Which makes the protected version suitable here.
7216 * The context lock guarantees that.
7218 hlist = rcu_dereference_protected(swhash->swevent_hlist,
7219 lockdep_is_held(&event->ctx->lock));
7223 return __find_swevent_head(hlist, type, event_id);
7226 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
7228 struct perf_sample_data *data,
7229 struct pt_regs *regs)
7231 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7232 struct perf_event *event;
7233 struct hlist_head *head;
7236 head = find_swevent_head_rcu(swhash, type, event_id);
7240 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7241 if (perf_swevent_match(event, type, event_id, data, regs))
7242 perf_swevent_event(event, nr, data, regs);
7248 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
7250 int perf_swevent_get_recursion_context(void)
7252 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7254 return get_recursion_context(swhash->recursion);
7256 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
7258 void perf_swevent_put_recursion_context(int rctx)
7260 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7262 put_recursion_context(swhash->recursion, rctx);
7265 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7267 struct perf_sample_data data;
7269 if (WARN_ON_ONCE(!regs))
7272 perf_sample_data_init(&data, addr, 0);
7273 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
7276 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7280 preempt_disable_notrace();
7281 rctx = perf_swevent_get_recursion_context();
7282 if (unlikely(rctx < 0))
7285 ___perf_sw_event(event_id, nr, regs, addr);
7287 perf_swevent_put_recursion_context(rctx);
7289 preempt_enable_notrace();
7292 static void perf_swevent_read(struct perf_event *event)
7296 static int perf_swevent_add(struct perf_event *event, int flags)
7298 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7299 struct hw_perf_event *hwc = &event->hw;
7300 struct hlist_head *head;
7302 if (is_sampling_event(event)) {
7303 hwc->last_period = hwc->sample_period;
7304 perf_swevent_set_period(event);
7307 hwc->state = !(flags & PERF_EF_START);
7309 head = find_swevent_head(swhash, event);
7310 if (WARN_ON_ONCE(!head))
7313 hlist_add_head_rcu(&event->hlist_entry, head);
7314 perf_event_update_userpage(event);
7319 static void perf_swevent_del(struct perf_event *event, int flags)
7321 hlist_del_rcu(&event->hlist_entry);
7324 static void perf_swevent_start(struct perf_event *event, int flags)
7326 event->hw.state = 0;
7329 static void perf_swevent_stop(struct perf_event *event, int flags)
7331 event->hw.state = PERF_HES_STOPPED;
7334 /* Deref the hlist from the update side */
7335 static inline struct swevent_hlist *
7336 swevent_hlist_deref(struct swevent_htable *swhash)
7338 return rcu_dereference_protected(swhash->swevent_hlist,
7339 lockdep_is_held(&swhash->hlist_mutex));
7342 static void swevent_hlist_release(struct swevent_htable *swhash)
7344 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
7349 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
7350 kfree_rcu(hlist, rcu_head);
7353 static void swevent_hlist_put_cpu(int cpu)
7355 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7357 mutex_lock(&swhash->hlist_mutex);
7359 if (!--swhash->hlist_refcount)
7360 swevent_hlist_release(swhash);
7362 mutex_unlock(&swhash->hlist_mutex);
7365 static void swevent_hlist_put(void)
7369 for_each_possible_cpu(cpu)
7370 swevent_hlist_put_cpu(cpu);
7373 static int swevent_hlist_get_cpu(int cpu)
7375 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7378 mutex_lock(&swhash->hlist_mutex);
7379 if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
7380 struct swevent_hlist *hlist;
7382 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
7387 rcu_assign_pointer(swhash->swevent_hlist, hlist);
7389 swhash->hlist_refcount++;
7391 mutex_unlock(&swhash->hlist_mutex);
7396 static int swevent_hlist_get(void)
7398 int err, cpu, failed_cpu;
7401 for_each_possible_cpu(cpu) {
7402 err = swevent_hlist_get_cpu(cpu);
7412 for_each_possible_cpu(cpu) {
7413 if (cpu == failed_cpu)
7415 swevent_hlist_put_cpu(cpu);
7422 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
7424 static void sw_perf_event_destroy(struct perf_event *event)
7426 u64 event_id = event->attr.config;
7428 WARN_ON(event->parent);
7430 static_key_slow_dec(&perf_swevent_enabled[event_id]);
7431 swevent_hlist_put();
7434 static int perf_swevent_init(struct perf_event *event)
7436 u64 event_id = event->attr.config;
7438 if (event->attr.type != PERF_TYPE_SOFTWARE)
7442 * no branch sampling for software events
7444 if (has_branch_stack(event))
7448 case PERF_COUNT_SW_CPU_CLOCK:
7449 case PERF_COUNT_SW_TASK_CLOCK:
7456 if (event_id >= PERF_COUNT_SW_MAX)
7459 if (!event->parent) {
7462 err = swevent_hlist_get();
7466 static_key_slow_inc(&perf_swevent_enabled[event_id]);
7467 event->destroy = sw_perf_event_destroy;
7473 static struct pmu perf_swevent = {
7474 .task_ctx_nr = perf_sw_context,
7476 .capabilities = PERF_PMU_CAP_NO_NMI,
7478 .event_init = perf_swevent_init,
7479 .add = perf_swevent_add,
7480 .del = perf_swevent_del,
7481 .start = perf_swevent_start,
7482 .stop = perf_swevent_stop,
7483 .read = perf_swevent_read,
7486 #ifdef CONFIG_EVENT_TRACING
7488 static int perf_tp_filter_match(struct perf_event *event,
7489 struct perf_sample_data *data)
7491 void *record = data->raw->frag.data;
7493 /* only top level events have filters set */
7495 event = event->parent;
7497 if (likely(!event->filter) || filter_match_preds(event->filter, record))
7502 static int perf_tp_event_match(struct perf_event *event,
7503 struct perf_sample_data *data,
7504 struct pt_regs *regs)
7506 if (event->hw.state & PERF_HES_STOPPED)
7509 * All tracepoints are from kernel-space.
7511 if (event->attr.exclude_kernel)
7514 if (!perf_tp_filter_match(event, data))
7520 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
7521 struct trace_event_call *call, u64 count,
7522 struct pt_regs *regs, struct hlist_head *head,
7523 struct task_struct *task)
7525 struct bpf_prog *prog = call->prog;
7528 *(struct pt_regs **)raw_data = regs;
7529 if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) {
7530 perf_swevent_put_recursion_context(rctx);
7534 perf_tp_event(call->event.type, count, raw_data, size, regs, head,
7537 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
7539 void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
7540 struct pt_regs *regs, struct hlist_head *head, int rctx,
7541 struct task_struct *task)
7543 struct perf_sample_data data;
7544 struct perf_event *event;
7546 struct perf_raw_record raw = {
7553 perf_sample_data_init(&data, 0, 0);
7556 perf_trace_buf_update(record, event_type);
7558 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7559 if (perf_tp_event_match(event, &data, regs))
7560 perf_swevent_event(event, count, &data, regs);
7564 * If we got specified a target task, also iterate its context and
7565 * deliver this event there too.
7567 if (task && task != current) {
7568 struct perf_event_context *ctx;
7569 struct trace_entry *entry = record;
7572 ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
7576 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
7577 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7579 if (event->attr.config != entry->type)
7581 if (perf_tp_event_match(event, &data, regs))
7582 perf_swevent_event(event, count, &data, regs);
7588 perf_swevent_put_recursion_context(rctx);
7590 EXPORT_SYMBOL_GPL(perf_tp_event);
7592 static void tp_perf_event_destroy(struct perf_event *event)
7594 perf_trace_destroy(event);
7597 static int perf_tp_event_init(struct perf_event *event)
7601 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7605 * no branch sampling for tracepoint events
7607 if (has_branch_stack(event))
7610 err = perf_trace_init(event);
7614 event->destroy = tp_perf_event_destroy;
7619 static struct pmu perf_tracepoint = {
7620 .task_ctx_nr = perf_sw_context,
7622 .event_init = perf_tp_event_init,
7623 .add = perf_trace_add,
7624 .del = perf_trace_del,
7625 .start = perf_swevent_start,
7626 .stop = perf_swevent_stop,
7627 .read = perf_swevent_read,
7630 static inline void perf_tp_register(void)
7632 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
7635 static void perf_event_free_filter(struct perf_event *event)
7637 ftrace_profile_free_filter(event);
7640 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7642 bool is_kprobe, is_tracepoint;
7643 struct bpf_prog *prog;
7645 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7648 if (event->tp_event->prog)
7651 is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE;
7652 is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
7653 if (!is_kprobe && !is_tracepoint)
7654 /* bpf programs can only be attached to u/kprobe or tracepoint */
7657 prog = bpf_prog_get(prog_fd);
7659 return PTR_ERR(prog);
7661 if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) ||
7662 (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT)) {
7663 /* valid fd, but invalid bpf program type */
7668 if (is_tracepoint) {
7669 int off = trace_event_get_offsets(event->tp_event);
7671 if (prog->aux->max_ctx_offset > off) {
7676 event->tp_event->prog = prog;
7681 static void perf_event_free_bpf_prog(struct perf_event *event)
7683 struct bpf_prog *prog;
7685 if (!event->tp_event)
7688 prog = event->tp_event->prog;
7690 event->tp_event->prog = NULL;
7697 static inline void perf_tp_register(void)
7701 static void perf_event_free_filter(struct perf_event *event)
7705 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7710 static void perf_event_free_bpf_prog(struct perf_event *event)
7713 #endif /* CONFIG_EVENT_TRACING */
7715 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7716 void perf_bp_event(struct perf_event *bp, void *data)
7718 struct perf_sample_data sample;
7719 struct pt_regs *regs = data;
7721 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
7723 if (!bp->hw.state && !perf_exclude_event(bp, regs))
7724 perf_swevent_event(bp, 1, &sample, regs);
7729 * Allocate a new address filter
7731 static struct perf_addr_filter *
7732 perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
7734 int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
7735 struct perf_addr_filter *filter;
7737 filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
7741 INIT_LIST_HEAD(&filter->entry);
7742 list_add_tail(&filter->entry, filters);
7747 static void free_filters_list(struct list_head *filters)
7749 struct perf_addr_filter *filter, *iter;
7751 list_for_each_entry_safe(filter, iter, filters, entry) {
7753 iput(filter->inode);
7754 list_del(&filter->entry);
7760 * Free existing address filters and optionally install new ones
7762 static void perf_addr_filters_splice(struct perf_event *event,
7763 struct list_head *head)
7765 unsigned long flags;
7768 if (!has_addr_filter(event))
7771 /* don't bother with children, they don't have their own filters */
7775 raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
7777 list_splice_init(&event->addr_filters.list, &list);
7779 list_splice(head, &event->addr_filters.list);
7781 raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
7783 free_filters_list(&list);
7787 * Scan through mm's vmas and see if one of them matches the
7788 * @filter; if so, adjust filter's address range.
7789 * Called with mm::mmap_sem down for reading.
7791 static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter,
7792 struct mm_struct *mm)
7794 struct vm_area_struct *vma;
7796 for (vma = mm->mmap; vma; vma = vma->vm_next) {
7797 struct file *file = vma->vm_file;
7798 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
7799 unsigned long vma_size = vma->vm_end - vma->vm_start;
7804 if (!perf_addr_filter_match(filter, file, off, vma_size))
7807 return vma->vm_start;
7814 * Update event's address range filters based on the
7815 * task's existing mappings, if any.
7817 static void perf_event_addr_filters_apply(struct perf_event *event)
7819 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
7820 struct task_struct *task = READ_ONCE(event->ctx->task);
7821 struct perf_addr_filter *filter;
7822 struct mm_struct *mm = NULL;
7823 unsigned int count = 0;
7824 unsigned long flags;
7827 * We may observe TASK_TOMBSTONE, which means that the event tear-down
7828 * will stop on the parent's child_mutex that our caller is also holding
7830 if (task == TASK_TOMBSTONE)
7833 mm = get_task_mm(event->ctx->task);
7837 down_read(&mm->mmap_sem);
7839 raw_spin_lock_irqsave(&ifh->lock, flags);
7840 list_for_each_entry(filter, &ifh->list, entry) {
7841 event->addr_filters_offs[count] = 0;
7844 * Adjust base offset if the filter is associated to a binary
7845 * that needs to be mapped:
7848 event->addr_filters_offs[count] =
7849 perf_addr_filter_apply(filter, mm);
7854 event->addr_filters_gen++;
7855 raw_spin_unlock_irqrestore(&ifh->lock, flags);
7857 up_read(&mm->mmap_sem);
7862 perf_event_restart(event);
7866 * Address range filtering: limiting the data to certain
7867 * instruction address ranges. Filters are ioctl()ed to us from
7868 * userspace as ascii strings.
7870 * Filter string format:
7873 * where ACTION is one of the
7874 * * "filter": limit the trace to this region
7875 * * "start": start tracing from this address
7876 * * "stop": stop tracing at this address/region;
7878 * * for kernel addresses: <start address>[/<size>]
7879 * * for object files: <start address>[/<size>]@</path/to/object/file>
7881 * if <size> is not specified, the range is treated as a single address.
7894 IF_STATE_ACTION = 0,
7899 static const match_table_t if_tokens = {
7900 { IF_ACT_FILTER, "filter" },
7901 { IF_ACT_START, "start" },
7902 { IF_ACT_STOP, "stop" },
7903 { IF_SRC_FILE, "%u/%u@%s" },
7904 { IF_SRC_KERNEL, "%u/%u" },
7905 { IF_SRC_FILEADDR, "%u@%s" },
7906 { IF_SRC_KERNELADDR, "%u" },
7910 * Address filter string parser
7913 perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
7914 struct list_head *filters)
7916 struct perf_addr_filter *filter = NULL;
7917 char *start, *orig, *filename = NULL;
7919 substring_t args[MAX_OPT_ARGS];
7920 int state = IF_STATE_ACTION, token;
7921 unsigned int kernel = 0;
7924 orig = fstr = kstrdup(fstr, GFP_KERNEL);
7928 while ((start = strsep(&fstr, " ,\n")) != NULL) {
7934 /* filter definition begins */
7935 if (state == IF_STATE_ACTION) {
7936 filter = perf_addr_filter_new(event, filters);
7941 token = match_token(start, if_tokens, args);
7948 if (state != IF_STATE_ACTION)
7951 state = IF_STATE_SOURCE;
7954 case IF_SRC_KERNELADDR:
7958 case IF_SRC_FILEADDR:
7960 if (state != IF_STATE_SOURCE)
7963 if (token == IF_SRC_FILE || token == IF_SRC_KERNEL)
7967 ret = kstrtoul(args[0].from, 0, &filter->offset);
7971 if (filter->range) {
7973 ret = kstrtoul(args[1].from, 0, &filter->size);
7978 if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
7979 int fpos = filter->range ? 2 : 1;
7981 filename = match_strdup(&args[fpos]);
7988 state = IF_STATE_END;
7996 * Filter definition is fully parsed, validate and install it.
7997 * Make sure that it doesn't contradict itself or the event's
8000 if (state == IF_STATE_END) {
8001 if (kernel && event->attr.exclude_kernel)
8008 /* look up the path and grab its inode */
8009 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
8011 goto fail_free_name;
8013 filter->inode = igrab(d_inode(path.dentry));
8019 if (!filter->inode ||
8020 !S_ISREG(filter->inode->i_mode))
8021 /* free_filters_list() will iput() */
8025 /* ready to consume more filters */
8026 state = IF_STATE_ACTION;
8031 if (state != IF_STATE_ACTION)
8041 free_filters_list(filters);
8048 perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
8054 * Since this is called in perf_ioctl() path, we're already holding
8057 lockdep_assert_held(&event->ctx->mutex);
8059 if (WARN_ON_ONCE(event->parent))
8063 * For now, we only support filtering in per-task events; doing so
8064 * for CPU-wide events requires additional context switching trickery,
8065 * since same object code will be mapped at different virtual
8066 * addresses in different processes.
8068 if (!event->ctx->task)
8071 ret = perf_event_parse_addr_filter(event, filter_str, &filters);
8075 ret = event->pmu->addr_filters_validate(&filters);
8077 free_filters_list(&filters);
8081 /* remove existing filters, if any */
8082 perf_addr_filters_splice(event, &filters);
8084 /* install new filters */
8085 perf_event_for_each_child(event, perf_event_addr_filters_apply);
8090 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
8095 if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
8096 !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
8097 !has_addr_filter(event))
8100 filter_str = strndup_user(arg, PAGE_SIZE);
8101 if (IS_ERR(filter_str))
8102 return PTR_ERR(filter_str);
8104 if (IS_ENABLED(CONFIG_EVENT_TRACING) &&
8105 event->attr.type == PERF_TYPE_TRACEPOINT)
8106 ret = ftrace_profile_set_filter(event, event->attr.config,
8108 else if (has_addr_filter(event))
8109 ret = perf_event_set_addr_filter(event, filter_str);
8116 * hrtimer based swevent callback
8119 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
8121 enum hrtimer_restart ret = HRTIMER_RESTART;
8122 struct perf_sample_data data;
8123 struct pt_regs *regs;
8124 struct perf_event *event;
8127 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
8129 if (event->state != PERF_EVENT_STATE_ACTIVE)
8130 return HRTIMER_NORESTART;
8132 event->pmu->read(event);
8134 perf_sample_data_init(&data, 0, event->hw.last_period);
8135 regs = get_irq_regs();
8137 if (regs && !perf_exclude_event(event, regs)) {
8138 if (!(event->attr.exclude_idle && is_idle_task(current)))
8139 if (__perf_event_overflow(event, 1, &data, regs))
8140 ret = HRTIMER_NORESTART;
8143 period = max_t(u64, 10000, event->hw.sample_period);
8144 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
8149 static void perf_swevent_start_hrtimer(struct perf_event *event)
8151 struct hw_perf_event *hwc = &event->hw;
8154 if (!is_sampling_event(event))
8157 period = local64_read(&hwc->period_left);
8162 local64_set(&hwc->period_left, 0);
8164 period = max_t(u64, 10000, hwc->sample_period);
8166 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
8167 HRTIMER_MODE_REL_PINNED);
8170 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
8172 struct hw_perf_event *hwc = &event->hw;
8174 if (is_sampling_event(event)) {
8175 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
8176 local64_set(&hwc->period_left, ktime_to_ns(remaining));
8178 hrtimer_cancel(&hwc->hrtimer);
8182 static void perf_swevent_init_hrtimer(struct perf_event *event)
8184 struct hw_perf_event *hwc = &event->hw;
8186 if (!is_sampling_event(event))
8189 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
8190 hwc->hrtimer.function = perf_swevent_hrtimer;
8193 * Since hrtimers have a fixed rate, we can do a static freq->period
8194 * mapping and avoid the whole period adjust feedback stuff.
8196 if (event->attr.freq) {
8197 long freq = event->attr.sample_freq;
8199 event->attr.sample_period = NSEC_PER_SEC / freq;
8200 hwc->sample_period = event->attr.sample_period;
8201 local64_set(&hwc->period_left, hwc->sample_period);
8202 hwc->last_period = hwc->sample_period;
8203 event->attr.freq = 0;
8208 * Software event: cpu wall time clock
8211 static void cpu_clock_event_update(struct perf_event *event)
8216 now = local_clock();
8217 prev = local64_xchg(&event->hw.prev_count, now);
8218 local64_add(now - prev, &event->count);
8221 static void cpu_clock_event_start(struct perf_event *event, int flags)
8223 local64_set(&event->hw.prev_count, local_clock());
8224 perf_swevent_start_hrtimer(event);
8227 static void cpu_clock_event_stop(struct perf_event *event, int flags)
8229 perf_swevent_cancel_hrtimer(event);
8230 cpu_clock_event_update(event);
8233 static int cpu_clock_event_add(struct perf_event *event, int flags)
8235 if (flags & PERF_EF_START)
8236 cpu_clock_event_start(event, flags);
8237 perf_event_update_userpage(event);
8242 static void cpu_clock_event_del(struct perf_event *event, int flags)
8244 cpu_clock_event_stop(event, flags);
8247 static void cpu_clock_event_read(struct perf_event *event)
8249 cpu_clock_event_update(event);
8252 static int cpu_clock_event_init(struct perf_event *event)
8254 if (event->attr.type != PERF_TYPE_SOFTWARE)
8257 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
8261 * no branch sampling for software events
8263 if (has_branch_stack(event))
8266 perf_swevent_init_hrtimer(event);
8271 static struct pmu perf_cpu_clock = {
8272 .task_ctx_nr = perf_sw_context,
8274 .capabilities = PERF_PMU_CAP_NO_NMI,
8276 .event_init = cpu_clock_event_init,
8277 .add = cpu_clock_event_add,
8278 .del = cpu_clock_event_del,
8279 .start = cpu_clock_event_start,
8280 .stop = cpu_clock_event_stop,
8281 .read = cpu_clock_event_read,
8285 * Software event: task time clock
8288 static void task_clock_event_update(struct perf_event *event, u64 now)
8293 prev = local64_xchg(&event->hw.prev_count, now);
8295 local64_add(delta, &event->count);
8298 static void task_clock_event_start(struct perf_event *event, int flags)
8300 local64_set(&event->hw.prev_count, event->ctx->time);
8301 perf_swevent_start_hrtimer(event);
8304 static void task_clock_event_stop(struct perf_event *event, int flags)
8306 perf_swevent_cancel_hrtimer(event);
8307 task_clock_event_update(event, event->ctx->time);
8310 static int task_clock_event_add(struct perf_event *event, int flags)
8312 if (flags & PERF_EF_START)
8313 task_clock_event_start(event, flags);
8314 perf_event_update_userpage(event);
8319 static void task_clock_event_del(struct perf_event *event, int flags)
8321 task_clock_event_stop(event, PERF_EF_UPDATE);
8324 static void task_clock_event_read(struct perf_event *event)
8326 u64 now = perf_clock();
8327 u64 delta = now - event->ctx->timestamp;
8328 u64 time = event->ctx->time + delta;
8330 task_clock_event_update(event, time);
8333 static int task_clock_event_init(struct perf_event *event)
8335 if (event->attr.type != PERF_TYPE_SOFTWARE)
8338 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
8342 * no branch sampling for software events
8344 if (has_branch_stack(event))
8347 perf_swevent_init_hrtimer(event);
8352 static struct pmu perf_task_clock = {
8353 .task_ctx_nr = perf_sw_context,
8355 .capabilities = PERF_PMU_CAP_NO_NMI,
8357 .event_init = task_clock_event_init,
8358 .add = task_clock_event_add,
8359 .del = task_clock_event_del,
8360 .start = task_clock_event_start,
8361 .stop = task_clock_event_stop,
8362 .read = task_clock_event_read,
8365 static void perf_pmu_nop_void(struct pmu *pmu)
8369 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
8373 static int perf_pmu_nop_int(struct pmu *pmu)
8378 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
8380 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
8382 __this_cpu_write(nop_txn_flags, flags);
8384 if (flags & ~PERF_PMU_TXN_ADD)
8387 perf_pmu_disable(pmu);
8390 static int perf_pmu_commit_txn(struct pmu *pmu)
8392 unsigned int flags = __this_cpu_read(nop_txn_flags);
8394 __this_cpu_write(nop_txn_flags, 0);
8396 if (flags & ~PERF_PMU_TXN_ADD)
8399 perf_pmu_enable(pmu);
8403 static void perf_pmu_cancel_txn(struct pmu *pmu)
8405 unsigned int flags = __this_cpu_read(nop_txn_flags);
8407 __this_cpu_write(nop_txn_flags, 0);
8409 if (flags & ~PERF_PMU_TXN_ADD)
8412 perf_pmu_enable(pmu);
8415 static int perf_event_idx_default(struct perf_event *event)
8421 * Ensures all contexts with the same task_ctx_nr have the same
8422 * pmu_cpu_context too.
8424 static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
8431 list_for_each_entry(pmu, &pmus, entry) {
8432 if (pmu->task_ctx_nr == ctxn)
8433 return pmu->pmu_cpu_context;
8439 static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
8443 for_each_possible_cpu(cpu) {
8444 struct perf_cpu_context *cpuctx;
8446 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8448 if (cpuctx->unique_pmu == old_pmu)
8449 cpuctx->unique_pmu = pmu;
8453 static void free_pmu_context(struct pmu *pmu)
8457 mutex_lock(&pmus_lock);
8459 * Like a real lame refcount.
8461 list_for_each_entry(i, &pmus, entry) {
8462 if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
8463 update_pmu_context(i, pmu);
8468 free_percpu(pmu->pmu_cpu_context);
8470 mutex_unlock(&pmus_lock);
8474 * Let userspace know that this PMU supports address range filtering:
8476 static ssize_t nr_addr_filters_show(struct device *dev,
8477 struct device_attribute *attr,
8480 struct pmu *pmu = dev_get_drvdata(dev);
8482 return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters);
8484 DEVICE_ATTR_RO(nr_addr_filters);
8486 static struct idr pmu_idr;
8489 type_show(struct device *dev, struct device_attribute *attr, char *page)
8491 struct pmu *pmu = dev_get_drvdata(dev);
8493 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
8495 static DEVICE_ATTR_RO(type);
8498 perf_event_mux_interval_ms_show(struct device *dev,
8499 struct device_attribute *attr,
8502 struct pmu *pmu = dev_get_drvdata(dev);
8504 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
8507 static DEFINE_MUTEX(mux_interval_mutex);
8510 perf_event_mux_interval_ms_store(struct device *dev,
8511 struct device_attribute *attr,
8512 const char *buf, size_t count)
8514 struct pmu *pmu = dev_get_drvdata(dev);
8515 int timer, cpu, ret;
8517 ret = kstrtoint(buf, 0, &timer);
8524 /* same value, noting to do */
8525 if (timer == pmu->hrtimer_interval_ms)
8528 mutex_lock(&mux_interval_mutex);
8529 pmu->hrtimer_interval_ms = timer;
8531 /* update all cpuctx for this PMU */
8533 for_each_online_cpu(cpu) {
8534 struct perf_cpu_context *cpuctx;
8535 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8536 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
8538 cpu_function_call(cpu,
8539 (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
8542 mutex_unlock(&mux_interval_mutex);
8546 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
8548 static struct attribute *pmu_dev_attrs[] = {
8549 &dev_attr_type.attr,
8550 &dev_attr_perf_event_mux_interval_ms.attr,
8553 ATTRIBUTE_GROUPS(pmu_dev);
8555 static int pmu_bus_running;
8556 static struct bus_type pmu_bus = {
8557 .name = "event_source",
8558 .dev_groups = pmu_dev_groups,
8561 static void pmu_dev_release(struct device *dev)
8566 static int pmu_dev_alloc(struct pmu *pmu)
8570 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
8574 pmu->dev->groups = pmu->attr_groups;
8575 device_initialize(pmu->dev);
8576 ret = dev_set_name(pmu->dev, "%s", pmu->name);
8580 dev_set_drvdata(pmu->dev, pmu);
8581 pmu->dev->bus = &pmu_bus;
8582 pmu->dev->release = pmu_dev_release;
8583 ret = device_add(pmu->dev);
8587 /* For PMUs with address filters, throw in an extra attribute: */
8588 if (pmu->nr_addr_filters)
8589 ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
8598 device_del(pmu->dev);
8601 put_device(pmu->dev);
8605 static struct lock_class_key cpuctx_mutex;
8606 static struct lock_class_key cpuctx_lock;
8608 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
8612 mutex_lock(&pmus_lock);
8614 pmu->pmu_disable_count = alloc_percpu(int);
8615 if (!pmu->pmu_disable_count)
8624 type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
8632 if (pmu_bus_running) {
8633 ret = pmu_dev_alloc(pmu);
8639 if (pmu->task_ctx_nr == perf_hw_context) {
8640 static int hw_context_taken = 0;
8643 * Other than systems with heterogeneous CPUs, it never makes
8644 * sense for two PMUs to share perf_hw_context. PMUs which are
8645 * uncore must use perf_invalid_context.
8647 if (WARN_ON_ONCE(hw_context_taken &&
8648 !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS)))
8649 pmu->task_ctx_nr = perf_invalid_context;
8651 hw_context_taken = 1;
8654 pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
8655 if (pmu->pmu_cpu_context)
8656 goto got_cpu_context;
8659 pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
8660 if (!pmu->pmu_cpu_context)
8663 for_each_possible_cpu(cpu) {
8664 struct perf_cpu_context *cpuctx;
8666 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8667 __perf_event_init_context(&cpuctx->ctx);
8668 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
8669 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
8670 cpuctx->ctx.pmu = pmu;
8672 __perf_mux_hrtimer_init(cpuctx, cpu);
8674 cpuctx->unique_pmu = pmu;
8678 if (!pmu->start_txn) {
8679 if (pmu->pmu_enable) {
8681 * If we have pmu_enable/pmu_disable calls, install
8682 * transaction stubs that use that to try and batch
8683 * hardware accesses.
8685 pmu->start_txn = perf_pmu_start_txn;
8686 pmu->commit_txn = perf_pmu_commit_txn;
8687 pmu->cancel_txn = perf_pmu_cancel_txn;
8689 pmu->start_txn = perf_pmu_nop_txn;
8690 pmu->commit_txn = perf_pmu_nop_int;
8691 pmu->cancel_txn = perf_pmu_nop_void;
8695 if (!pmu->pmu_enable) {
8696 pmu->pmu_enable = perf_pmu_nop_void;
8697 pmu->pmu_disable = perf_pmu_nop_void;
8700 if (!pmu->event_idx)
8701 pmu->event_idx = perf_event_idx_default;
8703 list_add_rcu(&pmu->entry, &pmus);
8704 atomic_set(&pmu->exclusive_cnt, 0);
8707 mutex_unlock(&pmus_lock);
8712 device_del(pmu->dev);
8713 put_device(pmu->dev);
8716 if (pmu->type >= PERF_TYPE_MAX)
8717 idr_remove(&pmu_idr, pmu->type);
8720 free_percpu(pmu->pmu_disable_count);
8723 EXPORT_SYMBOL_GPL(perf_pmu_register);
8725 void perf_pmu_unregister(struct pmu *pmu)
8727 mutex_lock(&pmus_lock);
8728 list_del_rcu(&pmu->entry);
8729 mutex_unlock(&pmus_lock);
8732 * We dereference the pmu list under both SRCU and regular RCU, so
8733 * synchronize against both of those.
8735 synchronize_srcu(&pmus_srcu);
8738 free_percpu(pmu->pmu_disable_count);
8739 if (pmu->type >= PERF_TYPE_MAX)
8740 idr_remove(&pmu_idr, pmu->type);
8741 if (pmu->nr_addr_filters)
8742 device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
8743 device_del(pmu->dev);
8744 put_device(pmu->dev);
8745 free_pmu_context(pmu);
8747 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
8749 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
8751 struct perf_event_context *ctx = NULL;
8754 if (!try_module_get(pmu->module))
8757 if (event->group_leader != event) {
8759 * This ctx->mutex can nest when we're called through
8760 * inheritance. See the perf_event_ctx_lock_nested() comment.
8762 ctx = perf_event_ctx_lock_nested(event->group_leader,
8763 SINGLE_DEPTH_NESTING);
8768 ret = pmu->event_init(event);
8771 perf_event_ctx_unlock(event->group_leader, ctx);
8774 module_put(pmu->module);
8779 static struct pmu *perf_init_event(struct perf_event *event)
8781 struct pmu *pmu = NULL;
8785 idx = srcu_read_lock(&pmus_srcu);
8788 pmu = idr_find(&pmu_idr, event->attr.type);
8791 ret = perf_try_init_event(pmu, event);
8797 list_for_each_entry_rcu(pmu, &pmus, entry) {
8798 ret = perf_try_init_event(pmu, event);
8802 if (ret != -ENOENT) {
8807 pmu = ERR_PTR(-ENOENT);
8809 srcu_read_unlock(&pmus_srcu, idx);
8814 static void attach_sb_event(struct perf_event *event)
8816 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
8818 raw_spin_lock(&pel->lock);
8819 list_add_rcu(&event->sb_list, &pel->list);
8820 raw_spin_unlock(&pel->lock);
8824 * We keep a list of all !task (and therefore per-cpu) events
8825 * that need to receive side-band records.
8827 * This avoids having to scan all the various PMU per-cpu contexts
8830 static void account_pmu_sb_event(struct perf_event *event)
8832 if (is_sb_event(event))
8833 attach_sb_event(event);
8836 static void account_event_cpu(struct perf_event *event, int cpu)
8841 if (is_cgroup_event(event))
8842 atomic_inc(&per_cpu(perf_cgroup_events, cpu));
8845 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
8846 static void account_freq_event_nohz(void)
8848 #ifdef CONFIG_NO_HZ_FULL
8849 /* Lock so we don't race with concurrent unaccount */
8850 spin_lock(&nr_freq_lock);
8851 if (atomic_inc_return(&nr_freq_events) == 1)
8852 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
8853 spin_unlock(&nr_freq_lock);
8857 static void account_freq_event(void)
8859 if (tick_nohz_full_enabled())
8860 account_freq_event_nohz();
8862 atomic_inc(&nr_freq_events);
8866 static void account_event(struct perf_event *event)
8873 if (event->attach_state & PERF_ATTACH_TASK)
8875 if (event->attr.mmap || event->attr.mmap_data)
8876 atomic_inc(&nr_mmap_events);
8877 if (event->attr.comm)
8878 atomic_inc(&nr_comm_events);
8879 if (event->attr.task)
8880 atomic_inc(&nr_task_events);
8881 if (event->attr.freq)
8882 account_freq_event();
8883 if (event->attr.context_switch) {
8884 atomic_inc(&nr_switch_events);
8887 if (has_branch_stack(event))
8889 if (is_cgroup_event(event))
8893 if (atomic_inc_not_zero(&perf_sched_count))
8896 mutex_lock(&perf_sched_mutex);
8897 if (!atomic_read(&perf_sched_count)) {
8898 static_branch_enable(&perf_sched_events);
8900 * Guarantee that all CPUs observe they key change and
8901 * call the perf scheduling hooks before proceeding to
8902 * install events that need them.
8904 synchronize_sched();
8907 * Now that we have waited for the sync_sched(), allow further
8908 * increments to by-pass the mutex.
8910 atomic_inc(&perf_sched_count);
8911 mutex_unlock(&perf_sched_mutex);
8915 account_event_cpu(event, event->cpu);
8917 account_pmu_sb_event(event);
8921 * Allocate and initialize a event structure
8923 static struct perf_event *
8924 perf_event_alloc(struct perf_event_attr *attr, int cpu,
8925 struct task_struct *task,
8926 struct perf_event *group_leader,
8927 struct perf_event *parent_event,
8928 perf_overflow_handler_t overflow_handler,
8929 void *context, int cgroup_fd)
8932 struct perf_event *event;
8933 struct hw_perf_event *hwc;
8936 if ((unsigned)cpu >= nr_cpu_ids) {
8937 if (!task || cpu != -1)
8938 return ERR_PTR(-EINVAL);
8941 event = kzalloc(sizeof(*event), GFP_KERNEL);
8943 return ERR_PTR(-ENOMEM);
8946 * Single events are their own group leaders, with an
8947 * empty sibling list:
8950 group_leader = event;
8952 mutex_init(&event->child_mutex);
8953 INIT_LIST_HEAD(&event->child_list);
8955 INIT_LIST_HEAD(&event->group_entry);
8956 INIT_LIST_HEAD(&event->event_entry);
8957 INIT_LIST_HEAD(&event->sibling_list);
8958 INIT_LIST_HEAD(&event->rb_entry);
8959 INIT_LIST_HEAD(&event->active_entry);
8960 INIT_LIST_HEAD(&event->addr_filters.list);
8961 INIT_HLIST_NODE(&event->hlist_entry);
8964 init_waitqueue_head(&event->waitq);
8965 init_irq_work(&event->pending, perf_pending_event);
8967 mutex_init(&event->mmap_mutex);
8968 raw_spin_lock_init(&event->addr_filters.lock);
8970 atomic_long_set(&event->refcount, 1);
8972 event->attr = *attr;
8973 event->group_leader = group_leader;
8977 event->parent = parent_event;
8979 event->ns = get_pid_ns(task_active_pid_ns(current));
8980 event->id = atomic64_inc_return(&perf_event_id);
8982 event->state = PERF_EVENT_STATE_INACTIVE;
8985 event->attach_state = PERF_ATTACH_TASK;
8987 * XXX pmu::event_init needs to know what task to account to
8988 * and we cannot use the ctx information because we need the
8989 * pmu before we get a ctx.
8991 event->hw.target = task;
8994 event->clock = &local_clock;
8996 event->clock = parent_event->clock;
8998 if (!overflow_handler && parent_event) {
8999 overflow_handler = parent_event->overflow_handler;
9000 context = parent_event->overflow_handler_context;
9003 if (overflow_handler) {
9004 event->overflow_handler = overflow_handler;
9005 event->overflow_handler_context = context;
9006 } else if (is_write_backward(event)){
9007 event->overflow_handler = perf_event_output_backward;
9008 event->overflow_handler_context = NULL;
9010 event->overflow_handler = perf_event_output_forward;
9011 event->overflow_handler_context = NULL;
9014 perf_event__state_init(event);
9019 hwc->sample_period = attr->sample_period;
9020 if (attr->freq && attr->sample_freq)
9021 hwc->sample_period = 1;
9022 hwc->last_period = hwc->sample_period;
9024 local64_set(&hwc->period_left, hwc->sample_period);
9027 * we currently do not support PERF_FORMAT_GROUP on inherited events
9029 if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
9032 if (!has_branch_stack(event))
9033 event->attr.branch_sample_type = 0;
9035 if (cgroup_fd != -1) {
9036 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
9041 pmu = perf_init_event(event);
9044 else if (IS_ERR(pmu)) {
9049 err = exclusive_event_init(event);
9053 if (has_addr_filter(event)) {
9054 event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
9055 sizeof(unsigned long),
9057 if (!event->addr_filters_offs)
9060 /* force hw sync on the address filters */
9061 event->addr_filters_gen = 1;
9064 if (!event->parent) {
9065 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
9066 err = get_callchain_buffers(attr->sample_max_stack);
9068 goto err_addr_filters;
9072 /* symmetric to unaccount_event() in _free_event() */
9073 account_event(event);
9078 kfree(event->addr_filters_offs);
9081 exclusive_event_destroy(event);
9085 event->destroy(event);
9086 module_put(pmu->module);
9088 if (is_cgroup_event(event))
9089 perf_detach_cgroup(event);
9091 put_pid_ns(event->ns);
9094 return ERR_PTR(err);
9097 static int perf_copy_attr(struct perf_event_attr __user *uattr,
9098 struct perf_event_attr *attr)
9103 if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
9107 * zero the full structure, so that a short copy will be nice.
9109 memset(attr, 0, sizeof(*attr));
9111 ret = get_user(size, &uattr->size);
9115 if (size > PAGE_SIZE) /* silly large */
9118 if (!size) /* abi compat */
9119 size = PERF_ATTR_SIZE_VER0;
9121 if (size < PERF_ATTR_SIZE_VER0)
9125 * If we're handed a bigger struct than we know of,
9126 * ensure all the unknown bits are 0 - i.e. new
9127 * user-space does not rely on any kernel feature
9128 * extensions we dont know about yet.
9130 if (size > sizeof(*attr)) {
9131 unsigned char __user *addr;
9132 unsigned char __user *end;
9135 addr = (void __user *)uattr + sizeof(*attr);
9136 end = (void __user *)uattr + size;
9138 for (; addr < end; addr++) {
9139 ret = get_user(val, addr);
9145 size = sizeof(*attr);
9148 ret = copy_from_user(attr, uattr, size);
9152 if (attr->__reserved_1)
9155 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
9158 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
9161 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
9162 u64 mask = attr->branch_sample_type;
9164 /* only using defined bits */
9165 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
9168 /* at least one branch bit must be set */
9169 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
9172 /* propagate priv level, when not set for branch */
9173 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
9175 /* exclude_kernel checked on syscall entry */
9176 if (!attr->exclude_kernel)
9177 mask |= PERF_SAMPLE_BRANCH_KERNEL;
9179 if (!attr->exclude_user)
9180 mask |= PERF_SAMPLE_BRANCH_USER;
9182 if (!attr->exclude_hv)
9183 mask |= PERF_SAMPLE_BRANCH_HV;
9185 * adjust user setting (for HW filter setup)
9187 attr->branch_sample_type = mask;
9189 /* privileged levels capture (kernel, hv): check permissions */
9190 if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
9191 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9195 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
9196 ret = perf_reg_validate(attr->sample_regs_user);
9201 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
9202 if (!arch_perf_have_user_stack_dump())
9206 * We have __u32 type for the size, but so far
9207 * we can only use __u16 as maximum due to the
9208 * __u16 sample size limit.
9210 if (attr->sample_stack_user >= USHRT_MAX)
9212 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
9216 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
9217 ret = perf_reg_validate(attr->sample_regs_intr);
9222 put_user(sizeof(*attr), &uattr->size);
9228 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
9230 struct ring_buffer *rb = NULL;
9236 /* don't allow circular references */
9237 if (event == output_event)
9241 * Don't allow cross-cpu buffers
9243 if (output_event->cpu != event->cpu)
9247 * If its not a per-cpu rb, it must be the same task.
9249 if (output_event->cpu == -1 && output_event->ctx != event->ctx)
9253 * Mixing clocks in the same buffer is trouble you don't need.
9255 if (output_event->clock != event->clock)
9259 * Either writing ring buffer from beginning or from end.
9260 * Mixing is not allowed.
9262 if (is_write_backward(output_event) != is_write_backward(event))
9266 * If both events generate aux data, they must be on the same PMU
9268 if (has_aux(event) && has_aux(output_event) &&
9269 event->pmu != output_event->pmu)
9273 mutex_lock(&event->mmap_mutex);
9274 /* Can't redirect output if we've got an active mmap() */
9275 if (atomic_read(&event->mmap_count))
9279 /* get the rb we want to redirect to */
9280 rb = ring_buffer_get(output_event);
9285 ring_buffer_attach(event, rb);
9289 mutex_unlock(&event->mmap_mutex);
9295 static void mutex_lock_double(struct mutex *a, struct mutex *b)
9301 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
9304 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
9306 bool nmi_safe = false;
9309 case CLOCK_MONOTONIC:
9310 event->clock = &ktime_get_mono_fast_ns;
9314 case CLOCK_MONOTONIC_RAW:
9315 event->clock = &ktime_get_raw_fast_ns;
9319 case CLOCK_REALTIME:
9320 event->clock = &ktime_get_real_ns;
9323 case CLOCK_BOOTTIME:
9324 event->clock = &ktime_get_boot_ns;
9328 event->clock = &ktime_get_tai_ns;
9335 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
9342 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9344 * @attr_uptr: event_id type attributes for monitoring/sampling
9347 * @group_fd: group leader event fd
9349 SYSCALL_DEFINE5(perf_event_open,
9350 struct perf_event_attr __user *, attr_uptr,
9351 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
9353 struct perf_event *group_leader = NULL, *output_event = NULL;
9354 struct perf_event *event, *sibling;
9355 struct perf_event_attr attr;
9356 struct perf_event_context *ctx, *uninitialized_var(gctx);
9357 struct file *event_file = NULL;
9358 struct fd group = {NULL, 0};
9359 struct task_struct *task = NULL;
9364 int f_flags = O_RDWR;
9367 /* for future expandability... */
9368 if (flags & ~PERF_FLAG_ALL)
9371 err = perf_copy_attr(attr_uptr, &attr);
9375 if (!attr.exclude_kernel) {
9376 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9381 if (attr.sample_freq > sysctl_perf_event_sample_rate)
9384 if (attr.sample_period & (1ULL << 63))
9388 if (!attr.sample_max_stack)
9389 attr.sample_max_stack = sysctl_perf_event_max_stack;
9392 * In cgroup mode, the pid argument is used to pass the fd
9393 * opened to the cgroup directory in cgroupfs. The cpu argument
9394 * designates the cpu on which to monitor threads from that
9397 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
9400 if (flags & PERF_FLAG_FD_CLOEXEC)
9401 f_flags |= O_CLOEXEC;
9403 event_fd = get_unused_fd_flags(f_flags);
9407 if (group_fd != -1) {
9408 err = perf_fget_light(group_fd, &group);
9411 group_leader = group.file->private_data;
9412 if (flags & PERF_FLAG_FD_OUTPUT)
9413 output_event = group_leader;
9414 if (flags & PERF_FLAG_FD_NO_GROUP)
9415 group_leader = NULL;
9418 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
9419 task = find_lively_task_by_vpid(pid);
9421 err = PTR_ERR(task);
9426 if (task && group_leader &&
9427 group_leader->attr.inherit != attr.inherit) {
9435 err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
9440 * Reuse ptrace permission checks for now.
9442 * We must hold cred_guard_mutex across this and any potential
9443 * perf_install_in_context() call for this new event to
9444 * serialize against exec() altering our credentials (and the
9445 * perf_event_exit_task() that could imply).
9448 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
9452 if (flags & PERF_FLAG_PID_CGROUP)
9455 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
9456 NULL, NULL, cgroup_fd);
9457 if (IS_ERR(event)) {
9458 err = PTR_ERR(event);
9462 if (is_sampling_event(event)) {
9463 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
9470 * Special case software events and allow them to be part of
9471 * any hardware group.
9475 if (attr.use_clockid) {
9476 err = perf_event_set_clock(event, attr.clockid);
9482 (is_software_event(event) != is_software_event(group_leader))) {
9483 if (is_software_event(event)) {
9485 * If event and group_leader are not both a software
9486 * event, and event is, then group leader is not.
9488 * Allow the addition of software events to !software
9489 * groups, this is safe because software events never
9492 pmu = group_leader->pmu;
9493 } else if (is_software_event(group_leader) &&
9494 (group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
9496 * In case the group is a pure software group, and we
9497 * try to add a hardware event, move the whole group to
9498 * the hardware context.
9505 * Get the target context (task or percpu):
9507 ctx = find_get_context(pmu, task, event);
9513 if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) {
9519 * Look up the group leader (we will attach this event to it):
9525 * Do not allow a recursive hierarchy (this new sibling
9526 * becoming part of another group-sibling):
9528 if (group_leader->group_leader != group_leader)
9531 /* All events in a group should have the same clock */
9532 if (group_leader->clock != event->clock)
9536 * Do not allow to attach to a group in a different
9537 * task or CPU context:
9541 * Make sure we're both on the same task, or both
9544 if (group_leader->ctx->task != ctx->task)
9548 * Make sure we're both events for the same CPU;
9549 * grouping events for different CPUs is broken; since
9550 * you can never concurrently schedule them anyhow.
9552 if (group_leader->cpu != event->cpu)
9555 if (group_leader->ctx != ctx)
9560 * Only a group leader can be exclusive or pinned
9562 if (attr.exclusive || attr.pinned)
9567 err = perf_event_set_output(event, output_event);
9572 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
9574 if (IS_ERR(event_file)) {
9575 err = PTR_ERR(event_file);
9581 gctx = group_leader->ctx;
9582 mutex_lock_double(&gctx->mutex, &ctx->mutex);
9583 if (gctx->task == TASK_TOMBSTONE) {
9588 mutex_lock(&ctx->mutex);
9591 if (ctx->task == TASK_TOMBSTONE) {
9596 if (!perf_event_validate_size(event)) {
9602 * Must be under the same ctx::mutex as perf_install_in_context(),
9603 * because we need to serialize with concurrent event creation.
9605 if (!exclusive_event_installable(event, ctx)) {
9606 /* exclusive and group stuff are assumed mutually exclusive */
9607 WARN_ON_ONCE(move_group);
9613 WARN_ON_ONCE(ctx->parent_ctx);
9616 * This is the point on no return; we cannot fail hereafter. This is
9617 * where we start modifying current state.
9622 * See perf_event_ctx_lock() for comments on the details
9623 * of swizzling perf_event::ctx.
9625 perf_remove_from_context(group_leader, 0);
9627 list_for_each_entry(sibling, &group_leader->sibling_list,
9629 perf_remove_from_context(sibling, 0);
9634 * Wait for everybody to stop referencing the events through
9635 * the old lists, before installing it on new lists.
9640 * Install the group siblings before the group leader.
9642 * Because a group leader will try and install the entire group
9643 * (through the sibling list, which is still in-tact), we can
9644 * end up with siblings installed in the wrong context.
9646 * By installing siblings first we NO-OP because they're not
9647 * reachable through the group lists.
9649 list_for_each_entry(sibling, &group_leader->sibling_list,
9651 perf_event__state_init(sibling);
9652 perf_install_in_context(ctx, sibling, sibling->cpu);
9657 * Removing from the context ends up with disabled
9658 * event. What we want here is event in the initial
9659 * startup state, ready to be add into new context.
9661 perf_event__state_init(group_leader);
9662 perf_install_in_context(ctx, group_leader, group_leader->cpu);
9666 * Now that all events are installed in @ctx, nothing
9667 * references @gctx anymore, so drop the last reference we have
9674 * Precalculate sample_data sizes; do while holding ctx::mutex such
9675 * that we're serialized against further additions and before
9676 * perf_install_in_context() which is the point the event is active and
9677 * can use these values.
9679 perf_event__header_size(event);
9680 perf_event__id_header_size(event);
9682 event->owner = current;
9684 perf_install_in_context(ctx, event, event->cpu);
9685 perf_unpin_context(ctx);
9688 mutex_unlock(&gctx->mutex);
9689 mutex_unlock(&ctx->mutex);
9692 mutex_unlock(&task->signal->cred_guard_mutex);
9693 put_task_struct(task);
9698 mutex_lock(¤t->perf_event_mutex);
9699 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
9700 mutex_unlock(¤t->perf_event_mutex);
9703 * Drop the reference on the group_event after placing the
9704 * new event on the sibling_list. This ensures destruction
9705 * of the group leader will find the pointer to itself in
9706 * perf_group_detach().
9709 fd_install(event_fd, event_file);
9714 mutex_unlock(&gctx->mutex);
9715 mutex_unlock(&ctx->mutex);
9719 perf_unpin_context(ctx);
9723 * If event_file is set, the fput() above will have called ->release()
9724 * and that will take care of freeing the event.
9730 mutex_unlock(&task->signal->cred_guard_mutex);
9735 put_task_struct(task);
9739 put_unused_fd(event_fd);
9744 * perf_event_create_kernel_counter
9746 * @attr: attributes of the counter to create
9747 * @cpu: cpu in which the counter is bound
9748 * @task: task to profile (NULL for percpu)
9751 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
9752 struct task_struct *task,
9753 perf_overflow_handler_t overflow_handler,
9756 struct perf_event_context *ctx;
9757 struct perf_event *event;
9761 * Get the target context (task or percpu):
9764 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
9765 overflow_handler, context, -1);
9766 if (IS_ERR(event)) {
9767 err = PTR_ERR(event);
9771 /* Mark owner so we could distinguish it from user events. */
9772 event->owner = TASK_TOMBSTONE;
9774 ctx = find_get_context(event->pmu, task, event);
9780 WARN_ON_ONCE(ctx->parent_ctx);
9781 mutex_lock(&ctx->mutex);
9782 if (ctx->task == TASK_TOMBSTONE) {
9787 if (!exclusive_event_installable(event, ctx)) {
9792 perf_install_in_context(ctx, event, cpu);
9793 perf_unpin_context(ctx);
9794 mutex_unlock(&ctx->mutex);
9799 mutex_unlock(&ctx->mutex);
9800 perf_unpin_context(ctx);
9805 return ERR_PTR(err);
9807 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
9809 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
9811 struct perf_event_context *src_ctx;
9812 struct perf_event_context *dst_ctx;
9813 struct perf_event *event, *tmp;
9816 src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
9817 dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
9820 * See perf_event_ctx_lock() for comments on the details
9821 * of swizzling perf_event::ctx.
9823 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
9824 list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
9826 perf_remove_from_context(event, 0);
9827 unaccount_event_cpu(event, src_cpu);
9829 list_add(&event->migrate_entry, &events);
9833 * Wait for the events to quiesce before re-instating them.
9838 * Re-instate events in 2 passes.
9840 * Skip over group leaders and only install siblings on this first
9841 * pass, siblings will not get enabled without a leader, however a
9842 * leader will enable its siblings, even if those are still on the old
9845 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
9846 if (event->group_leader == event)
9849 list_del(&event->migrate_entry);
9850 if (event->state >= PERF_EVENT_STATE_OFF)
9851 event->state = PERF_EVENT_STATE_INACTIVE;
9852 account_event_cpu(event, dst_cpu);
9853 perf_install_in_context(dst_ctx, event, dst_cpu);
9858 * Once all the siblings are setup properly, install the group leaders
9861 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
9862 list_del(&event->migrate_entry);
9863 if (event->state >= PERF_EVENT_STATE_OFF)
9864 event->state = PERF_EVENT_STATE_INACTIVE;
9865 account_event_cpu(event, dst_cpu);
9866 perf_install_in_context(dst_ctx, event, dst_cpu);
9869 mutex_unlock(&dst_ctx->mutex);
9870 mutex_unlock(&src_ctx->mutex);
9872 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
9874 static void sync_child_event(struct perf_event *child_event,
9875 struct task_struct *child)
9877 struct perf_event *parent_event = child_event->parent;
9880 if (child_event->attr.inherit_stat)
9881 perf_event_read_event(child_event, child);
9883 child_val = perf_event_count(child_event);
9886 * Add back the child's count to the parent's count:
9888 atomic64_add(child_val, &parent_event->child_count);
9889 atomic64_add(child_event->total_time_enabled,
9890 &parent_event->child_total_time_enabled);
9891 atomic64_add(child_event->total_time_running,
9892 &parent_event->child_total_time_running);
9896 perf_event_exit_event(struct perf_event *child_event,
9897 struct perf_event_context *child_ctx,
9898 struct task_struct *child)
9900 struct perf_event *parent_event = child_event->parent;
9903 * Do not destroy the 'original' grouping; because of the context
9904 * switch optimization the original events could've ended up in a
9905 * random child task.
9907 * If we were to destroy the original group, all group related
9908 * operations would cease to function properly after this random
9911 * Do destroy all inherited groups, we don't care about those
9912 * and being thorough is better.
9914 raw_spin_lock_irq(&child_ctx->lock);
9915 WARN_ON_ONCE(child_ctx->is_active);
9918 perf_group_detach(child_event);
9919 list_del_event(child_event, child_ctx);
9920 child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
9921 raw_spin_unlock_irq(&child_ctx->lock);
9924 * Parent events are governed by their filedesc, retain them.
9926 if (!parent_event) {
9927 perf_event_wakeup(child_event);
9931 * Child events can be cleaned up.
9934 sync_child_event(child_event, child);
9937 * Remove this event from the parent's list
9939 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
9940 mutex_lock(&parent_event->child_mutex);
9941 list_del_init(&child_event->child_list);
9942 mutex_unlock(&parent_event->child_mutex);
9945 * Kick perf_poll() for is_event_hup().
9947 perf_event_wakeup(parent_event);
9948 free_event(child_event);
9949 put_event(parent_event);
9952 static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
9954 struct perf_event_context *child_ctx, *clone_ctx = NULL;
9955 struct perf_event *child_event, *next;
9957 WARN_ON_ONCE(child != current);
9959 child_ctx = perf_pin_task_context(child, ctxn);
9964 * In order to reduce the amount of tricky in ctx tear-down, we hold
9965 * ctx::mutex over the entire thing. This serializes against almost
9966 * everything that wants to access the ctx.
9968 * The exception is sys_perf_event_open() /
9969 * perf_event_create_kernel_count() which does find_get_context()
9970 * without ctx::mutex (it cannot because of the move_group double mutex
9971 * lock thing). See the comments in perf_install_in_context().
9973 mutex_lock(&child_ctx->mutex);
9976 * In a single ctx::lock section, de-schedule the events and detach the
9977 * context from the task such that we cannot ever get it scheduled back
9980 raw_spin_lock_irq(&child_ctx->lock);
9981 task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx);
9984 * Now that the context is inactive, destroy the task <-> ctx relation
9985 * and mark the context dead.
9987 RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL);
9988 put_ctx(child_ctx); /* cannot be last */
9989 WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
9990 put_task_struct(current); /* cannot be last */
9992 clone_ctx = unclone_ctx(child_ctx);
9993 raw_spin_unlock_irq(&child_ctx->lock);
9999 * Report the task dead after unscheduling the events so that we
10000 * won't get any samples after PERF_RECORD_EXIT. We can however still
10001 * get a few PERF_RECORD_READ events.
10003 perf_event_task(child, child_ctx, 0);
10005 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
10006 perf_event_exit_event(child_event, child_ctx, child);
10008 mutex_unlock(&child_ctx->mutex);
10010 put_ctx(child_ctx);
10014 * When a child task exits, feed back event values to parent events.
10016 * Can be called with cred_guard_mutex held when called from
10017 * install_exec_creds().
10019 void perf_event_exit_task(struct task_struct *child)
10021 struct perf_event *event, *tmp;
10024 mutex_lock(&child->perf_event_mutex);
10025 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
10027 list_del_init(&event->owner_entry);
10030 * Ensure the list deletion is visible before we clear
10031 * the owner, closes a race against perf_release() where
10032 * we need to serialize on the owner->perf_event_mutex.
10034 smp_store_release(&event->owner, NULL);
10036 mutex_unlock(&child->perf_event_mutex);
10038 for_each_task_context_nr(ctxn)
10039 perf_event_exit_task_context(child, ctxn);
10042 * The perf_event_exit_task_context calls perf_event_task
10043 * with child's task_ctx, which generates EXIT events for
10044 * child contexts and sets child->perf_event_ctxp[] to NULL.
10045 * At this point we need to send EXIT events to cpu contexts.
10047 perf_event_task(child, NULL, 0);
10050 static void perf_free_event(struct perf_event *event,
10051 struct perf_event_context *ctx)
10053 struct perf_event *parent = event->parent;
10055 if (WARN_ON_ONCE(!parent))
10058 mutex_lock(&parent->child_mutex);
10059 list_del_init(&event->child_list);
10060 mutex_unlock(&parent->child_mutex);
10064 raw_spin_lock_irq(&ctx->lock);
10065 perf_group_detach(event);
10066 list_del_event(event, ctx);
10067 raw_spin_unlock_irq(&ctx->lock);
10072 * Free an unexposed, unused context as created by inheritance by
10073 * perf_event_init_task below, used by fork() in case of fail.
10075 * Not all locks are strictly required, but take them anyway to be nice and
10076 * help out with the lockdep assertions.
10078 void perf_event_free_task(struct task_struct *task)
10080 struct perf_event_context *ctx;
10081 struct perf_event *event, *tmp;
10084 for_each_task_context_nr(ctxn) {
10085 ctx = task->perf_event_ctxp[ctxn];
10089 mutex_lock(&ctx->mutex);
10091 list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
10093 perf_free_event(event, ctx);
10095 list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
10097 perf_free_event(event, ctx);
10099 if (!list_empty(&ctx->pinned_groups) ||
10100 !list_empty(&ctx->flexible_groups))
10103 mutex_unlock(&ctx->mutex);
10109 void perf_event_delayed_put(struct task_struct *task)
10113 for_each_task_context_nr(ctxn)
10114 WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
10117 struct file *perf_event_get(unsigned int fd)
10121 file = fget_raw(fd);
10123 return ERR_PTR(-EBADF);
10125 if (file->f_op != &perf_fops) {
10127 return ERR_PTR(-EBADF);
10133 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
10136 return ERR_PTR(-EINVAL);
10138 return &event->attr;
10142 * inherit a event from parent task to child task:
10144 static struct perf_event *
10145 inherit_event(struct perf_event *parent_event,
10146 struct task_struct *parent,
10147 struct perf_event_context *parent_ctx,
10148 struct task_struct *child,
10149 struct perf_event *group_leader,
10150 struct perf_event_context *child_ctx)
10152 enum perf_event_active_state parent_state = parent_event->state;
10153 struct perf_event *child_event;
10154 unsigned long flags;
10157 * Instead of creating recursive hierarchies of events,
10158 * we link inherited events back to the original parent,
10159 * which has a filp for sure, which we use as the reference
10162 if (parent_event->parent)
10163 parent_event = parent_event->parent;
10165 child_event = perf_event_alloc(&parent_event->attr,
10168 group_leader, parent_event,
10170 if (IS_ERR(child_event))
10171 return child_event;
10174 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10175 * must be under the same lock in order to serialize against
10176 * perf_event_release_kernel(), such that either we must observe
10177 * is_orphaned_event() or they will observe us on the child_list.
10179 mutex_lock(&parent_event->child_mutex);
10180 if (is_orphaned_event(parent_event) ||
10181 !atomic_long_inc_not_zero(&parent_event->refcount)) {
10182 mutex_unlock(&parent_event->child_mutex);
10183 free_event(child_event);
10187 get_ctx(child_ctx);
10190 * Make the child state follow the state of the parent event,
10191 * not its attr.disabled bit. We hold the parent's mutex,
10192 * so we won't race with perf_event_{en, dis}able_family.
10194 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
10195 child_event->state = PERF_EVENT_STATE_INACTIVE;
10197 child_event->state = PERF_EVENT_STATE_OFF;
10199 if (parent_event->attr.freq) {
10200 u64 sample_period = parent_event->hw.sample_period;
10201 struct hw_perf_event *hwc = &child_event->hw;
10203 hwc->sample_period = sample_period;
10204 hwc->last_period = sample_period;
10206 local64_set(&hwc->period_left, sample_period);
10209 child_event->ctx = child_ctx;
10210 child_event->overflow_handler = parent_event->overflow_handler;
10211 child_event->overflow_handler_context
10212 = parent_event->overflow_handler_context;
10215 * Precalculate sample_data sizes
10217 perf_event__header_size(child_event);
10218 perf_event__id_header_size(child_event);
10221 * Link it up in the child's context:
10223 raw_spin_lock_irqsave(&child_ctx->lock, flags);
10224 add_event_to_ctx(child_event, child_ctx);
10225 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
10228 * Link this into the parent event's child list
10230 list_add_tail(&child_event->child_list, &parent_event->child_list);
10231 mutex_unlock(&parent_event->child_mutex);
10233 return child_event;
10236 static int inherit_group(struct perf_event *parent_event,
10237 struct task_struct *parent,
10238 struct perf_event_context *parent_ctx,
10239 struct task_struct *child,
10240 struct perf_event_context *child_ctx)
10242 struct perf_event *leader;
10243 struct perf_event *sub;
10244 struct perf_event *child_ctr;
10246 leader = inherit_event(parent_event, parent, parent_ctx,
10247 child, NULL, child_ctx);
10248 if (IS_ERR(leader))
10249 return PTR_ERR(leader);
10250 list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
10251 child_ctr = inherit_event(sub, parent, parent_ctx,
10252 child, leader, child_ctx);
10253 if (IS_ERR(child_ctr))
10254 return PTR_ERR(child_ctr);
10260 inherit_task_group(struct perf_event *event, struct task_struct *parent,
10261 struct perf_event_context *parent_ctx,
10262 struct task_struct *child, int ctxn,
10263 int *inherited_all)
10266 struct perf_event_context *child_ctx;
10268 if (!event->attr.inherit) {
10269 *inherited_all = 0;
10273 child_ctx = child->perf_event_ctxp[ctxn];
10276 * This is executed from the parent task context, so
10277 * inherit events that have been marked for cloning.
10278 * First allocate and initialize a context for the
10282 child_ctx = alloc_perf_context(parent_ctx->pmu, child);
10286 child->perf_event_ctxp[ctxn] = child_ctx;
10289 ret = inherit_group(event, parent, parent_ctx,
10293 *inherited_all = 0;
10299 * Initialize the perf_event context in task_struct
10301 static int perf_event_init_context(struct task_struct *child, int ctxn)
10303 struct perf_event_context *child_ctx, *parent_ctx;
10304 struct perf_event_context *cloned_ctx;
10305 struct perf_event *event;
10306 struct task_struct *parent = current;
10307 int inherited_all = 1;
10308 unsigned long flags;
10311 if (likely(!parent->perf_event_ctxp[ctxn]))
10315 * If the parent's context is a clone, pin it so it won't get
10316 * swapped under us.
10318 parent_ctx = perf_pin_task_context(parent, ctxn);
10323 * No need to check if parent_ctx != NULL here; since we saw
10324 * it non-NULL earlier, the only reason for it to become NULL
10325 * is if we exit, and since we're currently in the middle of
10326 * a fork we can't be exiting at the same time.
10330 * Lock the parent list. No need to lock the child - not PID
10331 * hashed yet and not running, so nobody can access it.
10333 mutex_lock(&parent_ctx->mutex);
10336 * We dont have to disable NMIs - we are only looking at
10337 * the list, not manipulating it:
10339 list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
10340 ret = inherit_task_group(event, parent, parent_ctx,
10341 child, ctxn, &inherited_all);
10347 * We can't hold ctx->lock when iterating the ->flexible_group list due
10348 * to allocations, but we need to prevent rotation because
10349 * rotate_ctx() will change the list from interrupt context.
10351 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10352 parent_ctx->rotate_disable = 1;
10353 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10355 list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
10356 ret = inherit_task_group(event, parent, parent_ctx,
10357 child, ctxn, &inherited_all);
10362 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10363 parent_ctx->rotate_disable = 0;
10365 child_ctx = child->perf_event_ctxp[ctxn];
10367 if (child_ctx && inherited_all) {
10369 * Mark the child context as a clone of the parent
10370 * context, or of whatever the parent is a clone of.
10372 * Note that if the parent is a clone, the holding of
10373 * parent_ctx->lock avoids it from being uncloned.
10375 cloned_ctx = parent_ctx->parent_ctx;
10377 child_ctx->parent_ctx = cloned_ctx;
10378 child_ctx->parent_gen = parent_ctx->parent_gen;
10380 child_ctx->parent_ctx = parent_ctx;
10381 child_ctx->parent_gen = parent_ctx->generation;
10383 get_ctx(child_ctx->parent_ctx);
10386 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10387 mutex_unlock(&parent_ctx->mutex);
10389 perf_unpin_context(parent_ctx);
10390 put_ctx(parent_ctx);
10396 * Initialize the perf_event context in task_struct
10398 int perf_event_init_task(struct task_struct *child)
10402 memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
10403 mutex_init(&child->perf_event_mutex);
10404 INIT_LIST_HEAD(&child->perf_event_list);
10406 for_each_task_context_nr(ctxn) {
10407 ret = perf_event_init_context(child, ctxn);
10409 perf_event_free_task(child);
10417 static void __init perf_event_init_all_cpus(void)
10419 struct swevent_htable *swhash;
10422 for_each_possible_cpu(cpu) {
10423 swhash = &per_cpu(swevent_htable, cpu);
10424 mutex_init(&swhash->hlist_mutex);
10425 INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
10427 INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
10428 raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
10432 int perf_event_init_cpu(unsigned int cpu)
10434 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
10436 mutex_lock(&swhash->hlist_mutex);
10437 if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
10438 struct swevent_hlist *hlist;
10440 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
10442 rcu_assign_pointer(swhash->swevent_hlist, hlist);
10444 mutex_unlock(&swhash->hlist_mutex);
10448 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10449 static void __perf_event_exit_context(void *__info)
10451 struct perf_event_context *ctx = __info;
10452 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
10453 struct perf_event *event;
10455 raw_spin_lock(&ctx->lock);
10456 list_for_each_entry(event, &ctx->event_list, event_entry)
10457 __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
10458 raw_spin_unlock(&ctx->lock);
10461 static void perf_event_exit_cpu_context(int cpu)
10463 struct perf_event_context *ctx;
10467 idx = srcu_read_lock(&pmus_srcu);
10468 list_for_each_entry_rcu(pmu, &pmus, entry) {
10469 ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
10471 mutex_lock(&ctx->mutex);
10472 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
10473 mutex_unlock(&ctx->mutex);
10475 srcu_read_unlock(&pmus_srcu, idx);
10479 static void perf_event_exit_cpu_context(int cpu) { }
10483 int perf_event_exit_cpu(unsigned int cpu)
10485 perf_event_exit_cpu_context(cpu);
10490 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
10494 for_each_online_cpu(cpu)
10495 perf_event_exit_cpu(cpu);
10501 * Run the perf reboot notifier at the very last possible moment so that
10502 * the generic watchdog code runs as long as possible.
10504 static struct notifier_block perf_reboot_notifier = {
10505 .notifier_call = perf_reboot,
10506 .priority = INT_MIN,
10509 void __init perf_event_init(void)
10513 idr_init(&pmu_idr);
10515 perf_event_init_all_cpus();
10516 init_srcu_struct(&pmus_srcu);
10517 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
10518 perf_pmu_register(&perf_cpu_clock, NULL, -1);
10519 perf_pmu_register(&perf_task_clock, NULL, -1);
10520 perf_tp_register();
10521 perf_event_init_cpu(smp_processor_id());
10522 register_reboot_notifier(&perf_reboot_notifier);
10524 ret = init_hw_breakpoint();
10525 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
10528 * Build time assertion that we keep the data_head at the intended
10529 * location. IOW, validation we got the __reserved[] size right.
10531 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
10535 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
10538 struct perf_pmu_events_attr *pmu_attr =
10539 container_of(attr, struct perf_pmu_events_attr, attr);
10541 if (pmu_attr->event_str)
10542 return sprintf(page, "%s\n", pmu_attr->event_str);
10546 EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
10548 static int __init perf_event_sysfs_init(void)
10553 mutex_lock(&pmus_lock);
10555 ret = bus_register(&pmu_bus);
10559 list_for_each_entry(pmu, &pmus, entry) {
10560 if (!pmu->name || pmu->type < 0)
10563 ret = pmu_dev_alloc(pmu);
10564 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
10566 pmu_bus_running = 1;
10570 mutex_unlock(&pmus_lock);
10574 device_initcall(perf_event_sysfs_init);
10576 #ifdef CONFIG_CGROUP_PERF
10577 static struct cgroup_subsys_state *
10578 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
10580 struct perf_cgroup *jc;
10582 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
10584 return ERR_PTR(-ENOMEM);
10586 jc->info = alloc_percpu(struct perf_cgroup_info);
10589 return ERR_PTR(-ENOMEM);
10595 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
10597 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
10599 free_percpu(jc->info);
10603 static int __perf_cgroup_move(void *info)
10605 struct task_struct *task = info;
10607 perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
10612 static void perf_cgroup_attach(struct cgroup_taskset *tset)
10614 struct task_struct *task;
10615 struct cgroup_subsys_state *css;
10617 cgroup_taskset_for_each(task, css, tset)
10618 task_function_call(task, __perf_cgroup_move, task);
10621 struct cgroup_subsys perf_event_cgrp_subsys = {
10622 .css_alloc = perf_cgroup_css_alloc,
10623 .css_free = perf_cgroup_css_free,
10624 .attach = perf_cgroup_attach,
10626 #endif /* CONFIG_CGROUP_PERF */