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);
907 * cpuctx->cgrp is NULL until a cgroup event is sched in or
908 * ctx->nr_cgroup == 0 .
910 if (add && perf_cgroup_from_task(current, ctx) == event->cgrp)
911 cpuctx->cgrp = event->cgrp;
916 #else /* !CONFIG_CGROUP_PERF */
919 perf_cgroup_match(struct perf_event *event)
924 static inline void perf_detach_cgroup(struct perf_event *event)
927 static inline int is_cgroup_event(struct perf_event *event)
932 static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
937 static inline void update_cgrp_time_from_event(struct perf_event *event)
941 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
945 static inline void perf_cgroup_sched_out(struct task_struct *task,
946 struct task_struct *next)
950 static inline void perf_cgroup_sched_in(struct task_struct *prev,
951 struct task_struct *task)
955 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
956 struct perf_event_attr *attr,
957 struct perf_event *group_leader)
963 perf_cgroup_set_timestamp(struct task_struct *task,
964 struct perf_event_context *ctx)
969 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
974 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
978 static inline u64 perf_cgroup_event_time(struct perf_event *event)
984 perf_cgroup_defer_enabled(struct perf_event *event)
989 perf_cgroup_mark_enabled(struct perf_event *event,
990 struct perf_event_context *ctx)
995 list_update_cgroup_event(struct perf_event *event,
996 struct perf_event_context *ctx, bool add)
1003 * set default to be dependent on timer tick just
1004 * like original code
1006 #define PERF_CPU_HRTIMER (1000 / HZ)
1008 * function must be called with interrupts disbled
1010 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
1012 struct perf_cpu_context *cpuctx;
1015 WARN_ON(!irqs_disabled());
1017 cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
1018 rotations = perf_rotate_context(cpuctx);
1020 raw_spin_lock(&cpuctx->hrtimer_lock);
1022 hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
1024 cpuctx->hrtimer_active = 0;
1025 raw_spin_unlock(&cpuctx->hrtimer_lock);
1027 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
1030 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
1032 struct hrtimer *timer = &cpuctx->hrtimer;
1033 struct pmu *pmu = cpuctx->ctx.pmu;
1036 /* no multiplexing needed for SW PMU */
1037 if (pmu->task_ctx_nr == perf_sw_context)
1041 * check default is sane, if not set then force to
1042 * default interval (1/tick)
1044 interval = pmu->hrtimer_interval_ms;
1046 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
1048 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
1050 raw_spin_lock_init(&cpuctx->hrtimer_lock);
1051 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1052 timer->function = perf_mux_hrtimer_handler;
1055 static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
1057 struct hrtimer *timer = &cpuctx->hrtimer;
1058 struct pmu *pmu = cpuctx->ctx.pmu;
1059 unsigned long flags;
1061 /* not for SW PMU */
1062 if (pmu->task_ctx_nr == perf_sw_context)
1065 raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
1066 if (!cpuctx->hrtimer_active) {
1067 cpuctx->hrtimer_active = 1;
1068 hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
1069 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
1071 raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
1076 void perf_pmu_disable(struct pmu *pmu)
1078 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1080 pmu->pmu_disable(pmu);
1083 void perf_pmu_enable(struct pmu *pmu)
1085 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1087 pmu->pmu_enable(pmu);
1090 static DEFINE_PER_CPU(struct list_head, active_ctx_list);
1093 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1094 * perf_event_task_tick() are fully serialized because they're strictly cpu
1095 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1096 * disabled, while perf_event_task_tick is called from IRQ context.
1098 static void perf_event_ctx_activate(struct perf_event_context *ctx)
1100 struct list_head *head = this_cpu_ptr(&active_ctx_list);
1102 WARN_ON(!irqs_disabled());
1104 WARN_ON(!list_empty(&ctx->active_ctx_list));
1106 list_add(&ctx->active_ctx_list, head);
1109 static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
1111 WARN_ON(!irqs_disabled());
1113 WARN_ON(list_empty(&ctx->active_ctx_list));
1115 list_del_init(&ctx->active_ctx_list);
1118 static void get_ctx(struct perf_event_context *ctx)
1120 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
1123 static void free_ctx(struct rcu_head *head)
1125 struct perf_event_context *ctx;
1127 ctx = container_of(head, struct perf_event_context, rcu_head);
1128 kfree(ctx->task_ctx_data);
1132 static void put_ctx(struct perf_event_context *ctx)
1134 if (atomic_dec_and_test(&ctx->refcount)) {
1135 if (ctx->parent_ctx)
1136 put_ctx(ctx->parent_ctx);
1137 if (ctx->task && ctx->task != TASK_TOMBSTONE)
1138 put_task_struct(ctx->task);
1139 call_rcu(&ctx->rcu_head, free_ctx);
1144 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1145 * perf_pmu_migrate_context() we need some magic.
1147 * Those places that change perf_event::ctx will hold both
1148 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1150 * Lock ordering is by mutex address. There are two other sites where
1151 * perf_event_context::mutex nests and those are:
1153 * - perf_event_exit_task_context() [ child , 0 ]
1154 * perf_event_exit_event()
1155 * put_event() [ parent, 1 ]
1157 * - perf_event_init_context() [ parent, 0 ]
1158 * inherit_task_group()
1161 * perf_event_alloc()
1163 * perf_try_init_event() [ child , 1 ]
1165 * While it appears there is an obvious deadlock here -- the parent and child
1166 * nesting levels are inverted between the two. This is in fact safe because
1167 * life-time rules separate them. That is an exiting task cannot fork, and a
1168 * spawning task cannot (yet) exit.
1170 * But remember that that these are parent<->child context relations, and
1171 * migration does not affect children, therefore these two orderings should not
1174 * The change in perf_event::ctx does not affect children (as claimed above)
1175 * because the sys_perf_event_open() case will install a new event and break
1176 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1177 * concerned with cpuctx and that doesn't have children.
1179 * The places that change perf_event::ctx will issue:
1181 * perf_remove_from_context();
1182 * synchronize_rcu();
1183 * perf_install_in_context();
1185 * to affect the change. The remove_from_context() + synchronize_rcu() should
1186 * quiesce the event, after which we can install it in the new location. This
1187 * means that only external vectors (perf_fops, prctl) can perturb the event
1188 * while in transit. Therefore all such accessors should also acquire
1189 * perf_event_context::mutex to serialize against this.
1191 * However; because event->ctx can change while we're waiting to acquire
1192 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1197 * task_struct::perf_event_mutex
1198 * perf_event_context::mutex
1199 * perf_event::child_mutex;
1200 * perf_event_context::lock
1201 * perf_event::mmap_mutex
1204 static struct perf_event_context *
1205 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
1207 struct perf_event_context *ctx;
1211 ctx = ACCESS_ONCE(event->ctx);
1212 if (!atomic_inc_not_zero(&ctx->refcount)) {
1218 mutex_lock_nested(&ctx->mutex, nesting);
1219 if (event->ctx != ctx) {
1220 mutex_unlock(&ctx->mutex);
1228 static inline struct perf_event_context *
1229 perf_event_ctx_lock(struct perf_event *event)
1231 return perf_event_ctx_lock_nested(event, 0);
1234 static void perf_event_ctx_unlock(struct perf_event *event,
1235 struct perf_event_context *ctx)
1237 mutex_unlock(&ctx->mutex);
1242 * This must be done under the ctx->lock, such as to serialize against
1243 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1244 * calling scheduler related locks and ctx->lock nests inside those.
1246 static __must_check struct perf_event_context *
1247 unclone_ctx(struct perf_event_context *ctx)
1249 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1251 lockdep_assert_held(&ctx->lock);
1254 ctx->parent_ctx = NULL;
1260 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1263 * only top level events have the pid namespace they were created in
1266 event = event->parent;
1268 return task_tgid_nr_ns(p, event->ns);
1271 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1274 * only top level events have the pid namespace they were created in
1277 event = event->parent;
1279 return task_pid_nr_ns(p, event->ns);
1283 * If we inherit events we want to return the parent event id
1286 static u64 primary_event_id(struct perf_event *event)
1291 id = event->parent->id;
1297 * Get the perf_event_context for a task and lock it.
1299 * This has to cope with with the fact that until it is locked,
1300 * the context could get moved to another task.
1302 static struct perf_event_context *
1303 perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
1305 struct perf_event_context *ctx;
1309 * One of the few rules of preemptible RCU is that one cannot do
1310 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1311 * part of the read side critical section was irqs-enabled -- see
1312 * rcu_read_unlock_special().
1314 * Since ctx->lock nests under rq->lock we must ensure the entire read
1315 * side critical section has interrupts disabled.
1317 local_irq_save(*flags);
1319 ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
1322 * If this context is a clone of another, it might
1323 * get swapped for another underneath us by
1324 * perf_event_task_sched_out, though the
1325 * rcu_read_lock() protects us from any context
1326 * getting freed. Lock the context and check if it
1327 * got swapped before we could get the lock, and retry
1328 * if so. If we locked the right context, then it
1329 * can't get swapped on us any more.
1331 raw_spin_lock(&ctx->lock);
1332 if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
1333 raw_spin_unlock(&ctx->lock);
1335 local_irq_restore(*flags);
1339 if (ctx->task == TASK_TOMBSTONE ||
1340 !atomic_inc_not_zero(&ctx->refcount)) {
1341 raw_spin_unlock(&ctx->lock);
1344 WARN_ON_ONCE(ctx->task != task);
1349 local_irq_restore(*flags);
1354 * Get the context for a task and increment its pin_count so it
1355 * can't get swapped to another task. This also increments its
1356 * reference count so that the context can't get freed.
1358 static struct perf_event_context *
1359 perf_pin_task_context(struct task_struct *task, int ctxn)
1361 struct perf_event_context *ctx;
1362 unsigned long flags;
1364 ctx = perf_lock_task_context(task, ctxn, &flags);
1367 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1372 static void perf_unpin_context(struct perf_event_context *ctx)
1374 unsigned long flags;
1376 raw_spin_lock_irqsave(&ctx->lock, flags);
1378 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1382 * Update the record of the current time in a context.
1384 static void update_context_time(struct perf_event_context *ctx)
1386 u64 now = perf_clock();
1388 ctx->time += now - ctx->timestamp;
1389 ctx->timestamp = now;
1392 static u64 perf_event_time(struct perf_event *event)
1394 struct perf_event_context *ctx = event->ctx;
1396 if (is_cgroup_event(event))
1397 return perf_cgroup_event_time(event);
1399 return ctx ? ctx->time : 0;
1403 * Update the total_time_enabled and total_time_running fields for a event.
1405 static void update_event_times(struct perf_event *event)
1407 struct perf_event_context *ctx = event->ctx;
1410 lockdep_assert_held(&ctx->lock);
1412 if (event->state < PERF_EVENT_STATE_INACTIVE ||
1413 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
1417 * in cgroup mode, time_enabled represents
1418 * the time the event was enabled AND active
1419 * tasks were in the monitored cgroup. This is
1420 * independent of the activity of the context as
1421 * there may be a mix of cgroup and non-cgroup events.
1423 * That is why we treat cgroup events differently
1426 if (is_cgroup_event(event))
1427 run_end = perf_cgroup_event_time(event);
1428 else if (ctx->is_active)
1429 run_end = ctx->time;
1431 run_end = event->tstamp_stopped;
1433 event->total_time_enabled = run_end - event->tstamp_enabled;
1435 if (event->state == PERF_EVENT_STATE_INACTIVE)
1436 run_end = event->tstamp_stopped;
1438 run_end = perf_event_time(event);
1440 event->total_time_running = run_end - event->tstamp_running;
1445 * Update total_time_enabled and total_time_running for all events in a group.
1447 static void update_group_times(struct perf_event *leader)
1449 struct perf_event *event;
1451 update_event_times(leader);
1452 list_for_each_entry(event, &leader->sibling_list, group_entry)
1453 update_event_times(event);
1456 static struct list_head *
1457 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
1459 if (event->attr.pinned)
1460 return &ctx->pinned_groups;
1462 return &ctx->flexible_groups;
1466 * Add a event from the lists for its context.
1467 * Must be called with ctx->mutex and ctx->lock held.
1470 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1473 lockdep_assert_held(&ctx->lock);
1475 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1476 event->attach_state |= PERF_ATTACH_CONTEXT;
1479 * If we're a stand alone event or group leader, we go to the context
1480 * list, group events are kept attached to the group so that
1481 * perf_group_detach can, at all times, locate all siblings.
1483 if (event->group_leader == event) {
1484 struct list_head *list;
1486 event->group_caps = event->event_caps;
1488 list = ctx_group_list(event, ctx);
1489 list_add_tail(&event->group_entry, list);
1492 list_update_cgroup_event(event, ctx, true);
1494 list_add_rcu(&event->event_entry, &ctx->event_list);
1496 if (event->attr.inherit_stat)
1503 * Initialize event state based on the perf_event_attr::disabled.
1505 static inline void perf_event__state_init(struct perf_event *event)
1507 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1508 PERF_EVENT_STATE_INACTIVE;
1511 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1513 int entry = sizeof(u64); /* value */
1517 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1518 size += sizeof(u64);
1520 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1521 size += sizeof(u64);
1523 if (event->attr.read_format & PERF_FORMAT_ID)
1524 entry += sizeof(u64);
1526 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1528 size += sizeof(u64);
1532 event->read_size = size;
1535 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1537 struct perf_sample_data *data;
1540 if (sample_type & PERF_SAMPLE_IP)
1541 size += sizeof(data->ip);
1543 if (sample_type & PERF_SAMPLE_ADDR)
1544 size += sizeof(data->addr);
1546 if (sample_type & PERF_SAMPLE_PERIOD)
1547 size += sizeof(data->period);
1549 if (sample_type & PERF_SAMPLE_WEIGHT)
1550 size += sizeof(data->weight);
1552 if (sample_type & PERF_SAMPLE_READ)
1553 size += event->read_size;
1555 if (sample_type & PERF_SAMPLE_DATA_SRC)
1556 size += sizeof(data->data_src.val);
1558 if (sample_type & PERF_SAMPLE_TRANSACTION)
1559 size += sizeof(data->txn);
1561 event->header_size = size;
1565 * Called at perf_event creation and when events are attached/detached from a
1568 static void perf_event__header_size(struct perf_event *event)
1570 __perf_event_read_size(event,
1571 event->group_leader->nr_siblings);
1572 __perf_event_header_size(event, event->attr.sample_type);
1575 static void perf_event__id_header_size(struct perf_event *event)
1577 struct perf_sample_data *data;
1578 u64 sample_type = event->attr.sample_type;
1581 if (sample_type & PERF_SAMPLE_TID)
1582 size += sizeof(data->tid_entry);
1584 if (sample_type & PERF_SAMPLE_TIME)
1585 size += sizeof(data->time);
1587 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1588 size += sizeof(data->id);
1590 if (sample_type & PERF_SAMPLE_ID)
1591 size += sizeof(data->id);
1593 if (sample_type & PERF_SAMPLE_STREAM_ID)
1594 size += sizeof(data->stream_id);
1596 if (sample_type & PERF_SAMPLE_CPU)
1597 size += sizeof(data->cpu_entry);
1599 event->id_header_size = size;
1602 static bool perf_event_validate_size(struct perf_event *event)
1605 * The values computed here will be over-written when we actually
1608 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1609 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1610 perf_event__id_header_size(event);
1613 * Sum the lot; should not exceed the 64k limit we have on records.
1614 * Conservative limit to allow for callchains and other variable fields.
1616 if (event->read_size + event->header_size +
1617 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1623 static void perf_group_attach(struct perf_event *event)
1625 struct perf_event *group_leader = event->group_leader, *pos;
1628 * We can have double attach due to group movement in perf_event_open.
1630 if (event->attach_state & PERF_ATTACH_GROUP)
1633 event->attach_state |= PERF_ATTACH_GROUP;
1635 if (group_leader == event)
1638 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1640 group_leader->group_caps &= event->event_caps;
1642 list_add_tail(&event->group_entry, &group_leader->sibling_list);
1643 group_leader->nr_siblings++;
1645 perf_event__header_size(group_leader);
1647 list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
1648 perf_event__header_size(pos);
1652 * Remove a event from the lists for its context.
1653 * Must be called with ctx->mutex and ctx->lock held.
1656 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1658 WARN_ON_ONCE(event->ctx != ctx);
1659 lockdep_assert_held(&ctx->lock);
1662 * We can have double detach due to exit/hot-unplug + close.
1664 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1667 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1669 list_update_cgroup_event(event, ctx, false);
1672 if (event->attr.inherit_stat)
1675 list_del_rcu(&event->event_entry);
1677 if (event->group_leader == event)
1678 list_del_init(&event->group_entry);
1680 update_group_times(event);
1683 * If event was in error state, then keep it
1684 * that way, otherwise bogus counts will be
1685 * returned on read(). The only way to get out
1686 * of error state is by explicit re-enabling
1689 if (event->state > PERF_EVENT_STATE_OFF)
1690 event->state = PERF_EVENT_STATE_OFF;
1695 static void perf_group_detach(struct perf_event *event)
1697 struct perf_event *sibling, *tmp;
1698 struct list_head *list = NULL;
1701 * We can have double detach due to exit/hot-unplug + close.
1703 if (!(event->attach_state & PERF_ATTACH_GROUP))
1706 event->attach_state &= ~PERF_ATTACH_GROUP;
1709 * If this is a sibling, remove it from its group.
1711 if (event->group_leader != event) {
1712 list_del_init(&event->group_entry);
1713 event->group_leader->nr_siblings--;
1717 if (!list_empty(&event->group_entry))
1718 list = &event->group_entry;
1721 * If this was a group event with sibling events then
1722 * upgrade the siblings to singleton events by adding them
1723 * to whatever list we are on.
1725 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
1727 list_move_tail(&sibling->group_entry, list);
1728 sibling->group_leader = sibling;
1730 /* Inherit group flags from the previous leader */
1731 sibling->group_caps = event->group_caps;
1733 WARN_ON_ONCE(sibling->ctx != event->ctx);
1737 perf_event__header_size(event->group_leader);
1739 list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
1740 perf_event__header_size(tmp);
1743 static bool is_orphaned_event(struct perf_event *event)
1745 return event->state == PERF_EVENT_STATE_DEAD;
1748 static inline int __pmu_filter_match(struct perf_event *event)
1750 struct pmu *pmu = event->pmu;
1751 return pmu->filter_match ? pmu->filter_match(event) : 1;
1755 * Check whether we should attempt to schedule an event group based on
1756 * PMU-specific filtering. An event group can consist of HW and SW events,
1757 * potentially with a SW leader, so we must check all the filters, to
1758 * determine whether a group is schedulable:
1760 static inline int pmu_filter_match(struct perf_event *event)
1762 struct perf_event *child;
1764 if (!__pmu_filter_match(event))
1767 list_for_each_entry(child, &event->sibling_list, group_entry) {
1768 if (!__pmu_filter_match(child))
1776 event_filter_match(struct perf_event *event)
1778 return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
1779 perf_cgroup_match(event) && pmu_filter_match(event);
1783 event_sched_out(struct perf_event *event,
1784 struct perf_cpu_context *cpuctx,
1785 struct perf_event_context *ctx)
1787 u64 tstamp = perf_event_time(event);
1790 WARN_ON_ONCE(event->ctx != ctx);
1791 lockdep_assert_held(&ctx->lock);
1794 * An event which could not be activated because of
1795 * filter mismatch still needs to have its timings
1796 * maintained, otherwise bogus information is return
1797 * via read() for time_enabled, time_running:
1799 if (event->state == PERF_EVENT_STATE_INACTIVE &&
1800 !event_filter_match(event)) {
1801 delta = tstamp - event->tstamp_stopped;
1802 event->tstamp_running += delta;
1803 event->tstamp_stopped = tstamp;
1806 if (event->state != PERF_EVENT_STATE_ACTIVE)
1809 perf_pmu_disable(event->pmu);
1811 event->tstamp_stopped = tstamp;
1812 event->pmu->del(event, 0);
1814 event->state = PERF_EVENT_STATE_INACTIVE;
1815 if (event->pending_disable) {
1816 event->pending_disable = 0;
1817 event->state = PERF_EVENT_STATE_OFF;
1820 if (!is_software_event(event))
1821 cpuctx->active_oncpu--;
1822 if (!--ctx->nr_active)
1823 perf_event_ctx_deactivate(ctx);
1824 if (event->attr.freq && event->attr.sample_freq)
1826 if (event->attr.exclusive || !cpuctx->active_oncpu)
1827 cpuctx->exclusive = 0;
1829 perf_pmu_enable(event->pmu);
1833 group_sched_out(struct perf_event *group_event,
1834 struct perf_cpu_context *cpuctx,
1835 struct perf_event_context *ctx)
1837 struct perf_event *event;
1838 int state = group_event->state;
1840 perf_pmu_disable(ctx->pmu);
1842 event_sched_out(group_event, cpuctx, ctx);
1845 * Schedule out siblings (if any):
1847 list_for_each_entry(event, &group_event->sibling_list, group_entry)
1848 event_sched_out(event, cpuctx, ctx);
1850 perf_pmu_enable(ctx->pmu);
1852 if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
1853 cpuctx->exclusive = 0;
1856 #define DETACH_GROUP 0x01UL
1859 * Cross CPU call to remove a performance event
1861 * We disable the event on the hardware level first. After that we
1862 * remove it from the context list.
1865 __perf_remove_from_context(struct perf_event *event,
1866 struct perf_cpu_context *cpuctx,
1867 struct perf_event_context *ctx,
1870 unsigned long flags = (unsigned long)info;
1872 event_sched_out(event, cpuctx, ctx);
1873 if (flags & DETACH_GROUP)
1874 perf_group_detach(event);
1875 list_del_event(event, ctx);
1877 if (!ctx->nr_events && ctx->is_active) {
1880 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
1881 cpuctx->task_ctx = NULL;
1887 * Remove the event from a task's (or a CPU's) list of events.
1889 * If event->ctx is a cloned context, callers must make sure that
1890 * every task struct that event->ctx->task could possibly point to
1891 * remains valid. This is OK when called from perf_release since
1892 * that only calls us on the top-level context, which can't be a clone.
1893 * When called from perf_event_exit_task, it's OK because the
1894 * context has been detached from its task.
1896 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
1898 lockdep_assert_held(&event->ctx->mutex);
1900 event_function_call(event, __perf_remove_from_context, (void *)flags);
1904 * Cross CPU call to disable a performance event
1906 static void __perf_event_disable(struct perf_event *event,
1907 struct perf_cpu_context *cpuctx,
1908 struct perf_event_context *ctx,
1911 if (event->state < PERF_EVENT_STATE_INACTIVE)
1914 update_context_time(ctx);
1915 update_cgrp_time_from_event(event);
1916 update_group_times(event);
1917 if (event == event->group_leader)
1918 group_sched_out(event, cpuctx, ctx);
1920 event_sched_out(event, cpuctx, ctx);
1921 event->state = PERF_EVENT_STATE_OFF;
1927 * If event->ctx is a cloned context, callers must make sure that
1928 * every task struct that event->ctx->task could possibly point to
1929 * remains valid. This condition is satisifed when called through
1930 * perf_event_for_each_child or perf_event_for_each because they
1931 * hold the top-level event's child_mutex, so any descendant that
1932 * goes to exit will block in perf_event_exit_event().
1934 * When called from perf_pending_event it's OK because event->ctx
1935 * is the current context on this CPU and preemption is disabled,
1936 * hence we can't get into perf_event_task_sched_out for this context.
1938 static void _perf_event_disable(struct perf_event *event)
1940 struct perf_event_context *ctx = event->ctx;
1942 raw_spin_lock_irq(&ctx->lock);
1943 if (event->state <= PERF_EVENT_STATE_OFF) {
1944 raw_spin_unlock_irq(&ctx->lock);
1947 raw_spin_unlock_irq(&ctx->lock);
1949 event_function_call(event, __perf_event_disable, NULL);
1952 void perf_event_disable_local(struct perf_event *event)
1954 event_function_local(event, __perf_event_disable, NULL);
1958 * Strictly speaking kernel users cannot create groups and therefore this
1959 * interface does not need the perf_event_ctx_lock() magic.
1961 void perf_event_disable(struct perf_event *event)
1963 struct perf_event_context *ctx;
1965 ctx = perf_event_ctx_lock(event);
1966 _perf_event_disable(event);
1967 perf_event_ctx_unlock(event, ctx);
1969 EXPORT_SYMBOL_GPL(perf_event_disable);
1971 void perf_event_disable_inatomic(struct perf_event *event)
1973 event->pending_disable = 1;
1974 irq_work_queue(&event->pending);
1977 static void perf_set_shadow_time(struct perf_event *event,
1978 struct perf_event_context *ctx,
1982 * use the correct time source for the time snapshot
1984 * We could get by without this by leveraging the
1985 * fact that to get to this function, the caller
1986 * has most likely already called update_context_time()
1987 * and update_cgrp_time_xx() and thus both timestamp
1988 * are identical (or very close). Given that tstamp is,
1989 * already adjusted for cgroup, we could say that:
1990 * tstamp - ctx->timestamp
1992 * tstamp - cgrp->timestamp.
1994 * Then, in perf_output_read(), the calculation would
1995 * work with no changes because:
1996 * - event is guaranteed scheduled in
1997 * - no scheduled out in between
1998 * - thus the timestamp would be the same
2000 * But this is a bit hairy.
2002 * So instead, we have an explicit cgroup call to remain
2003 * within the time time source all along. We believe it
2004 * is cleaner and simpler to understand.
2006 if (is_cgroup_event(event))
2007 perf_cgroup_set_shadow_time(event, tstamp);
2009 event->shadow_ctx_time = tstamp - ctx->timestamp;
2012 #define MAX_INTERRUPTS (~0ULL)
2014 static void perf_log_throttle(struct perf_event *event, int enable);
2015 static void perf_log_itrace_start(struct perf_event *event);
2018 event_sched_in(struct perf_event *event,
2019 struct perf_cpu_context *cpuctx,
2020 struct perf_event_context *ctx)
2022 u64 tstamp = perf_event_time(event);
2025 lockdep_assert_held(&ctx->lock);
2027 if (event->state <= PERF_EVENT_STATE_OFF)
2030 WRITE_ONCE(event->oncpu, smp_processor_id());
2032 * Order event::oncpu write to happen before the ACTIVE state
2036 WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE);
2039 * Unthrottle events, since we scheduled we might have missed several
2040 * ticks already, also for a heavily scheduling task there is little
2041 * guarantee it'll get a tick in a timely manner.
2043 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
2044 perf_log_throttle(event, 1);
2045 event->hw.interrupts = 0;
2049 * The new state must be visible before we turn it on in the hardware:
2053 perf_pmu_disable(event->pmu);
2055 perf_set_shadow_time(event, ctx, tstamp);
2057 perf_log_itrace_start(event);
2059 if (event->pmu->add(event, PERF_EF_START)) {
2060 event->state = PERF_EVENT_STATE_INACTIVE;
2066 event->tstamp_running += tstamp - event->tstamp_stopped;
2068 if (!is_software_event(event))
2069 cpuctx->active_oncpu++;
2070 if (!ctx->nr_active++)
2071 perf_event_ctx_activate(ctx);
2072 if (event->attr.freq && event->attr.sample_freq)
2075 if (event->attr.exclusive)
2076 cpuctx->exclusive = 1;
2079 perf_pmu_enable(event->pmu);
2085 group_sched_in(struct perf_event *group_event,
2086 struct perf_cpu_context *cpuctx,
2087 struct perf_event_context *ctx)
2089 struct perf_event *event, *partial_group = NULL;
2090 struct pmu *pmu = ctx->pmu;
2091 u64 now = ctx->time;
2092 bool simulate = false;
2094 if (group_event->state == PERF_EVENT_STATE_OFF)
2097 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
2099 if (event_sched_in(group_event, cpuctx, ctx)) {
2100 pmu->cancel_txn(pmu);
2101 perf_mux_hrtimer_restart(cpuctx);
2106 * Schedule in siblings as one group (if any):
2108 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2109 if (event_sched_in(event, cpuctx, ctx)) {
2110 partial_group = event;
2115 if (!pmu->commit_txn(pmu))
2120 * Groups can be scheduled in as one unit only, so undo any
2121 * partial group before returning:
2122 * The events up to the failed event are scheduled out normally,
2123 * tstamp_stopped will be updated.
2125 * The failed events and the remaining siblings need to have
2126 * their timings updated as if they had gone thru event_sched_in()
2127 * and event_sched_out(). This is required to get consistent timings
2128 * across the group. This also takes care of the case where the group
2129 * could never be scheduled by ensuring tstamp_stopped is set to mark
2130 * the time the event was actually stopped, such that time delta
2131 * calculation in update_event_times() is correct.
2133 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2134 if (event == partial_group)
2138 event->tstamp_running += now - event->tstamp_stopped;
2139 event->tstamp_stopped = now;
2141 event_sched_out(event, cpuctx, ctx);
2144 event_sched_out(group_event, cpuctx, ctx);
2146 pmu->cancel_txn(pmu);
2148 perf_mux_hrtimer_restart(cpuctx);
2154 * Work out whether we can put this event group on the CPU now.
2156 static int group_can_go_on(struct perf_event *event,
2157 struct perf_cpu_context *cpuctx,
2161 * Groups consisting entirely of software events can always go on.
2163 if (event->group_caps & PERF_EV_CAP_SOFTWARE)
2166 * If an exclusive group is already on, no other hardware
2169 if (cpuctx->exclusive)
2172 * If this group is exclusive and there are already
2173 * events on the CPU, it can't go on.
2175 if (event->attr.exclusive && cpuctx->active_oncpu)
2178 * Otherwise, try to add it if all previous groups were able
2184 static void add_event_to_ctx(struct perf_event *event,
2185 struct perf_event_context *ctx)
2187 u64 tstamp = perf_event_time(event);
2189 list_add_event(event, ctx);
2190 perf_group_attach(event);
2191 event->tstamp_enabled = tstamp;
2192 event->tstamp_running = tstamp;
2193 event->tstamp_stopped = tstamp;
2196 static void ctx_sched_out(struct perf_event_context *ctx,
2197 struct perf_cpu_context *cpuctx,
2198 enum event_type_t event_type);
2200 ctx_sched_in(struct perf_event_context *ctx,
2201 struct perf_cpu_context *cpuctx,
2202 enum event_type_t event_type,
2203 struct task_struct *task);
2205 static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
2206 struct perf_event_context *ctx)
2208 if (!cpuctx->task_ctx)
2211 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2214 ctx_sched_out(ctx, cpuctx, EVENT_ALL);
2217 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2218 struct perf_event_context *ctx,
2219 struct task_struct *task)
2221 cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
2223 ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
2224 cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
2226 ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
2229 static void ctx_resched(struct perf_cpu_context *cpuctx,
2230 struct perf_event_context *task_ctx)
2232 perf_pmu_disable(cpuctx->ctx.pmu);
2234 task_ctx_sched_out(cpuctx, task_ctx);
2235 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
2236 perf_event_sched_in(cpuctx, task_ctx, current);
2237 perf_pmu_enable(cpuctx->ctx.pmu);
2241 * Cross CPU call to install and enable a performance event
2243 * Very similar to remote_function() + event_function() but cannot assume that
2244 * things like ctx->is_active and cpuctx->task_ctx are set.
2246 static int __perf_install_in_context(void *info)
2248 struct perf_event *event = info;
2249 struct perf_event_context *ctx = event->ctx;
2250 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2251 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2252 bool activate = true;
2255 raw_spin_lock(&cpuctx->ctx.lock);
2257 raw_spin_lock(&ctx->lock);
2260 /* If we're on the wrong CPU, try again */
2261 if (task_cpu(ctx->task) != smp_processor_id()) {
2267 * If we're on the right CPU, see if the task we target is
2268 * current, if not we don't have to activate the ctx, a future
2269 * context switch will do that for us.
2271 if (ctx->task != current)
2274 WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2276 } else if (task_ctx) {
2277 raw_spin_lock(&task_ctx->lock);
2281 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2282 add_event_to_ctx(event, ctx);
2283 ctx_resched(cpuctx, task_ctx);
2285 add_event_to_ctx(event, ctx);
2289 perf_ctx_unlock(cpuctx, task_ctx);
2295 * Attach a performance event to a context.
2297 * Very similar to event_function_call, see comment there.
2300 perf_install_in_context(struct perf_event_context *ctx,
2301 struct perf_event *event,
2304 struct task_struct *task = READ_ONCE(ctx->task);
2306 lockdep_assert_held(&ctx->mutex);
2308 if (event->cpu != -1)
2312 * Ensures that if we can observe event->ctx, both the event and ctx
2313 * will be 'complete'. See perf_iterate_sb_cpu().
2315 smp_store_release(&event->ctx, ctx);
2318 cpu_function_call(cpu, __perf_install_in_context, event);
2323 * Should not happen, we validate the ctx is still alive before calling.
2325 if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
2329 * Installing events is tricky because we cannot rely on ctx->is_active
2330 * to be set in case this is the nr_events 0 -> 1 transition.
2334 * Cannot use task_function_call() because we need to run on the task's
2335 * CPU regardless of whether its current or not.
2337 if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event))
2340 raw_spin_lock_irq(&ctx->lock);
2342 if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
2344 * Cannot happen because we already checked above (which also
2345 * cannot happen), and we hold ctx->mutex, which serializes us
2346 * against perf_event_exit_task_context().
2348 raw_spin_unlock_irq(&ctx->lock);
2351 raw_spin_unlock_irq(&ctx->lock);
2353 * Since !ctx->is_active doesn't mean anything, we must IPI
2360 * Put a event into inactive state and update time fields.
2361 * Enabling the leader of a group effectively enables all
2362 * the group members that aren't explicitly disabled, so we
2363 * have to update their ->tstamp_enabled also.
2364 * Note: this works for group members as well as group leaders
2365 * since the non-leader members' sibling_lists will be empty.
2367 static void __perf_event_mark_enabled(struct perf_event *event)
2369 struct perf_event *sub;
2370 u64 tstamp = perf_event_time(event);
2372 event->state = PERF_EVENT_STATE_INACTIVE;
2373 event->tstamp_enabled = tstamp - event->total_time_enabled;
2374 list_for_each_entry(sub, &event->sibling_list, group_entry) {
2375 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
2376 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
2381 * Cross CPU call to enable a performance event
2383 static void __perf_event_enable(struct perf_event *event,
2384 struct perf_cpu_context *cpuctx,
2385 struct perf_event_context *ctx,
2388 struct perf_event *leader = event->group_leader;
2389 struct perf_event_context *task_ctx;
2391 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2392 event->state <= PERF_EVENT_STATE_ERROR)
2396 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2398 __perf_event_mark_enabled(event);
2400 if (!ctx->is_active)
2403 if (!event_filter_match(event)) {
2404 if (is_cgroup_event(event))
2405 perf_cgroup_defer_enabled(event);
2406 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2411 * If the event is in a group and isn't the group leader,
2412 * then don't put it on unless the group is on.
2414 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
2415 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2419 task_ctx = cpuctx->task_ctx;
2421 WARN_ON_ONCE(task_ctx != ctx);
2423 ctx_resched(cpuctx, task_ctx);
2429 * If event->ctx is a cloned context, callers must make sure that
2430 * every task struct that event->ctx->task could possibly point to
2431 * remains valid. This condition is satisfied when called through
2432 * perf_event_for_each_child or perf_event_for_each as described
2433 * for perf_event_disable.
2435 static void _perf_event_enable(struct perf_event *event)
2437 struct perf_event_context *ctx = event->ctx;
2439 raw_spin_lock_irq(&ctx->lock);
2440 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2441 event->state < PERF_EVENT_STATE_ERROR) {
2442 raw_spin_unlock_irq(&ctx->lock);
2447 * If the event is in error state, clear that first.
2449 * That way, if we see the event in error state below, we know that it
2450 * has gone back into error state, as distinct from the task having
2451 * been scheduled away before the cross-call arrived.
2453 if (event->state == PERF_EVENT_STATE_ERROR)
2454 event->state = PERF_EVENT_STATE_OFF;
2455 raw_spin_unlock_irq(&ctx->lock);
2457 event_function_call(event, __perf_event_enable, NULL);
2461 * See perf_event_disable();
2463 void perf_event_enable(struct perf_event *event)
2465 struct perf_event_context *ctx;
2467 ctx = perf_event_ctx_lock(event);
2468 _perf_event_enable(event);
2469 perf_event_ctx_unlock(event, ctx);
2471 EXPORT_SYMBOL_GPL(perf_event_enable);
2473 struct stop_event_data {
2474 struct perf_event *event;
2475 unsigned int restart;
2478 static int __perf_event_stop(void *info)
2480 struct stop_event_data *sd = info;
2481 struct perf_event *event = sd->event;
2483 /* if it's already INACTIVE, do nothing */
2484 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2487 /* matches smp_wmb() in event_sched_in() */
2491 * There is a window with interrupts enabled before we get here,
2492 * so we need to check again lest we try to stop another CPU's event.
2494 if (READ_ONCE(event->oncpu) != smp_processor_id())
2497 event->pmu->stop(event, PERF_EF_UPDATE);
2500 * May race with the actual stop (through perf_pmu_output_stop()),
2501 * but it is only used for events with AUX ring buffer, and such
2502 * events will refuse to restart because of rb::aux_mmap_count==0,
2503 * see comments in perf_aux_output_begin().
2505 * Since this is happening on a event-local CPU, no trace is lost
2509 event->pmu->start(event, 0);
2514 static int perf_event_stop(struct perf_event *event, int restart)
2516 struct stop_event_data sd = {
2523 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2526 /* matches smp_wmb() in event_sched_in() */
2530 * We only want to restart ACTIVE events, so if the event goes
2531 * inactive here (event->oncpu==-1), there's nothing more to do;
2532 * fall through with ret==-ENXIO.
2534 ret = cpu_function_call(READ_ONCE(event->oncpu),
2535 __perf_event_stop, &sd);
2536 } while (ret == -EAGAIN);
2542 * In order to contain the amount of racy and tricky in the address filter
2543 * configuration management, it is a two part process:
2545 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2546 * we update the addresses of corresponding vmas in
2547 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2548 * (p2) when an event is scheduled in (pmu::add), it calls
2549 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2550 * if the generation has changed since the previous call.
2552 * If (p1) happens while the event is active, we restart it to force (p2).
2554 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2555 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2557 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2558 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2560 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2563 void perf_event_addr_filters_sync(struct perf_event *event)
2565 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
2567 if (!has_addr_filter(event))
2570 raw_spin_lock(&ifh->lock);
2571 if (event->addr_filters_gen != event->hw.addr_filters_gen) {
2572 event->pmu->addr_filters_sync(event);
2573 event->hw.addr_filters_gen = event->addr_filters_gen;
2575 raw_spin_unlock(&ifh->lock);
2577 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
2579 static int _perf_event_refresh(struct perf_event *event, int refresh)
2582 * not supported on inherited events
2584 if (event->attr.inherit || !is_sampling_event(event))
2587 atomic_add(refresh, &event->event_limit);
2588 _perf_event_enable(event);
2594 * See perf_event_disable()
2596 int perf_event_refresh(struct perf_event *event, int refresh)
2598 struct perf_event_context *ctx;
2601 ctx = perf_event_ctx_lock(event);
2602 ret = _perf_event_refresh(event, refresh);
2603 perf_event_ctx_unlock(event, ctx);
2607 EXPORT_SYMBOL_GPL(perf_event_refresh);
2609 static void ctx_sched_out(struct perf_event_context *ctx,
2610 struct perf_cpu_context *cpuctx,
2611 enum event_type_t event_type)
2613 int is_active = ctx->is_active;
2614 struct perf_event *event;
2616 lockdep_assert_held(&ctx->lock);
2618 if (likely(!ctx->nr_events)) {
2620 * See __perf_remove_from_context().
2622 WARN_ON_ONCE(ctx->is_active);
2624 WARN_ON_ONCE(cpuctx->task_ctx);
2628 ctx->is_active &= ~event_type;
2629 if (!(ctx->is_active & EVENT_ALL))
2633 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
2634 if (!ctx->is_active)
2635 cpuctx->task_ctx = NULL;
2639 * Always update time if it was set; not only when it changes.
2640 * Otherwise we can 'forget' to update time for any but the last
2641 * context we sched out. For example:
2643 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2644 * ctx_sched_out(.event_type = EVENT_PINNED)
2646 * would only update time for the pinned events.
2648 if (is_active & EVENT_TIME) {
2649 /* update (and stop) ctx time */
2650 update_context_time(ctx);
2651 update_cgrp_time_from_cpuctx(cpuctx);
2654 is_active ^= ctx->is_active; /* changed bits */
2656 if (!ctx->nr_active || !(is_active & EVENT_ALL))
2659 perf_pmu_disable(ctx->pmu);
2660 if (is_active & EVENT_PINNED) {
2661 list_for_each_entry(event, &ctx->pinned_groups, group_entry)
2662 group_sched_out(event, cpuctx, ctx);
2665 if (is_active & EVENT_FLEXIBLE) {
2666 list_for_each_entry(event, &ctx->flexible_groups, group_entry)
2667 group_sched_out(event, cpuctx, ctx);
2669 perf_pmu_enable(ctx->pmu);
2673 * Test whether two contexts are equivalent, i.e. whether they have both been
2674 * cloned from the same version of the same context.
2676 * Equivalence is measured using a generation number in the context that is
2677 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2678 * and list_del_event().
2680 static int context_equiv(struct perf_event_context *ctx1,
2681 struct perf_event_context *ctx2)
2683 lockdep_assert_held(&ctx1->lock);
2684 lockdep_assert_held(&ctx2->lock);
2686 /* Pinning disables the swap optimization */
2687 if (ctx1->pin_count || ctx2->pin_count)
2690 /* If ctx1 is the parent of ctx2 */
2691 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
2694 /* If ctx2 is the parent of ctx1 */
2695 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
2699 * If ctx1 and ctx2 have the same parent; we flatten the parent
2700 * hierarchy, see perf_event_init_context().
2702 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
2703 ctx1->parent_gen == ctx2->parent_gen)
2710 static void __perf_event_sync_stat(struct perf_event *event,
2711 struct perf_event *next_event)
2715 if (!event->attr.inherit_stat)
2719 * Update the event value, we cannot use perf_event_read()
2720 * because we're in the middle of a context switch and have IRQs
2721 * disabled, which upsets smp_call_function_single(), however
2722 * we know the event must be on the current CPU, therefore we
2723 * don't need to use it.
2725 switch (event->state) {
2726 case PERF_EVENT_STATE_ACTIVE:
2727 event->pmu->read(event);
2730 case PERF_EVENT_STATE_INACTIVE:
2731 update_event_times(event);
2739 * In order to keep per-task stats reliable we need to flip the event
2740 * values when we flip the contexts.
2742 value = local64_read(&next_event->count);
2743 value = local64_xchg(&event->count, value);
2744 local64_set(&next_event->count, value);
2746 swap(event->total_time_enabled, next_event->total_time_enabled);
2747 swap(event->total_time_running, next_event->total_time_running);
2750 * Since we swizzled the values, update the user visible data too.
2752 perf_event_update_userpage(event);
2753 perf_event_update_userpage(next_event);
2756 static void perf_event_sync_stat(struct perf_event_context *ctx,
2757 struct perf_event_context *next_ctx)
2759 struct perf_event *event, *next_event;
2764 update_context_time(ctx);
2766 event = list_first_entry(&ctx->event_list,
2767 struct perf_event, event_entry);
2769 next_event = list_first_entry(&next_ctx->event_list,
2770 struct perf_event, event_entry);
2772 while (&event->event_entry != &ctx->event_list &&
2773 &next_event->event_entry != &next_ctx->event_list) {
2775 __perf_event_sync_stat(event, next_event);
2777 event = list_next_entry(event, event_entry);
2778 next_event = list_next_entry(next_event, event_entry);
2782 static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
2783 struct task_struct *next)
2785 struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
2786 struct perf_event_context *next_ctx;
2787 struct perf_event_context *parent, *next_parent;
2788 struct perf_cpu_context *cpuctx;
2794 cpuctx = __get_cpu_context(ctx);
2795 if (!cpuctx->task_ctx)
2799 next_ctx = next->perf_event_ctxp[ctxn];
2803 parent = rcu_dereference(ctx->parent_ctx);
2804 next_parent = rcu_dereference(next_ctx->parent_ctx);
2806 /* If neither context have a parent context; they cannot be clones. */
2807 if (!parent && !next_parent)
2810 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
2812 * Looks like the two contexts are clones, so we might be
2813 * able to optimize the context switch. We lock both
2814 * contexts and check that they are clones under the
2815 * lock (including re-checking that neither has been
2816 * uncloned in the meantime). It doesn't matter which
2817 * order we take the locks because no other cpu could
2818 * be trying to lock both of these tasks.
2820 raw_spin_lock(&ctx->lock);
2821 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
2822 if (context_equiv(ctx, next_ctx)) {
2823 WRITE_ONCE(ctx->task, next);
2824 WRITE_ONCE(next_ctx->task, task);
2826 swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
2829 * RCU_INIT_POINTER here is safe because we've not
2830 * modified the ctx and the above modification of
2831 * ctx->task and ctx->task_ctx_data are immaterial
2832 * since those values are always verified under
2833 * ctx->lock which we're now holding.
2835 RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx);
2836 RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx);
2840 perf_event_sync_stat(ctx, next_ctx);
2842 raw_spin_unlock(&next_ctx->lock);
2843 raw_spin_unlock(&ctx->lock);
2849 raw_spin_lock(&ctx->lock);
2850 task_ctx_sched_out(cpuctx, ctx);
2851 raw_spin_unlock(&ctx->lock);
2855 static DEFINE_PER_CPU(struct list_head, sched_cb_list);
2857 void perf_sched_cb_dec(struct pmu *pmu)
2859 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2861 this_cpu_dec(perf_sched_cb_usages);
2863 if (!--cpuctx->sched_cb_usage)
2864 list_del(&cpuctx->sched_cb_entry);
2868 void perf_sched_cb_inc(struct pmu *pmu)
2870 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2872 if (!cpuctx->sched_cb_usage++)
2873 list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
2875 this_cpu_inc(perf_sched_cb_usages);
2879 * This function provides the context switch callback to the lower code
2880 * layer. It is invoked ONLY when the context switch callback is enabled.
2882 * This callback is relevant even to per-cpu events; for example multi event
2883 * PEBS requires this to provide PID/TID information. This requires we flush
2884 * all queued PEBS records before we context switch to a new task.
2886 static void perf_pmu_sched_task(struct task_struct *prev,
2887 struct task_struct *next,
2890 struct perf_cpu_context *cpuctx;
2896 list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
2897 pmu = cpuctx->unique_pmu; /* software PMUs will not have sched_task */
2899 if (WARN_ON_ONCE(!pmu->sched_task))
2902 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
2903 perf_pmu_disable(pmu);
2905 pmu->sched_task(cpuctx->task_ctx, sched_in);
2907 perf_pmu_enable(pmu);
2908 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2912 static void perf_event_switch(struct task_struct *task,
2913 struct task_struct *next_prev, bool sched_in);
2915 #define for_each_task_context_nr(ctxn) \
2916 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2919 * Called from scheduler to remove the events of the current task,
2920 * with interrupts disabled.
2922 * We stop each event and update the event value in event->count.
2924 * This does not protect us against NMI, but disable()
2925 * sets the disabled bit in the control field of event _before_
2926 * accessing the event control register. If a NMI hits, then it will
2927 * not restart the event.
2929 void __perf_event_task_sched_out(struct task_struct *task,
2930 struct task_struct *next)
2934 if (__this_cpu_read(perf_sched_cb_usages))
2935 perf_pmu_sched_task(task, next, false);
2937 if (atomic_read(&nr_switch_events))
2938 perf_event_switch(task, next, false);
2940 for_each_task_context_nr(ctxn)
2941 perf_event_context_sched_out(task, ctxn, next);
2944 * if cgroup events exist on this CPU, then we need
2945 * to check if we have to switch out PMU state.
2946 * cgroup event are system-wide mode only
2948 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
2949 perf_cgroup_sched_out(task, next);
2953 * Called with IRQs disabled
2955 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
2956 enum event_type_t event_type)
2958 ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
2962 ctx_pinned_sched_in(struct perf_event_context *ctx,
2963 struct perf_cpu_context *cpuctx)
2965 struct perf_event *event;
2967 list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
2968 if (event->state <= PERF_EVENT_STATE_OFF)
2970 if (!event_filter_match(event))
2973 /* may need to reset tstamp_enabled */
2974 if (is_cgroup_event(event))
2975 perf_cgroup_mark_enabled(event, ctx);
2977 if (group_can_go_on(event, cpuctx, 1))
2978 group_sched_in(event, cpuctx, ctx);
2981 * If this pinned group hasn't been scheduled,
2982 * put it in error state.
2984 if (event->state == PERF_EVENT_STATE_INACTIVE) {
2985 update_group_times(event);
2986 event->state = PERF_EVENT_STATE_ERROR;
2992 ctx_flexible_sched_in(struct perf_event_context *ctx,
2993 struct perf_cpu_context *cpuctx)
2995 struct perf_event *event;
2998 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
2999 /* Ignore events in OFF or ERROR state */
3000 if (event->state <= PERF_EVENT_STATE_OFF)
3003 * Listen to the 'cpu' scheduling filter constraint
3006 if (!event_filter_match(event))
3009 /* may need to reset tstamp_enabled */
3010 if (is_cgroup_event(event))
3011 perf_cgroup_mark_enabled(event, ctx);
3013 if (group_can_go_on(event, cpuctx, can_add_hw)) {
3014 if (group_sched_in(event, cpuctx, ctx))
3021 ctx_sched_in(struct perf_event_context *ctx,
3022 struct perf_cpu_context *cpuctx,
3023 enum event_type_t event_type,
3024 struct task_struct *task)
3026 int is_active = ctx->is_active;
3029 lockdep_assert_held(&ctx->lock);
3031 if (likely(!ctx->nr_events))
3034 ctx->is_active |= (event_type | EVENT_TIME);
3037 cpuctx->task_ctx = ctx;
3039 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3042 is_active ^= ctx->is_active; /* changed bits */
3044 if (is_active & EVENT_TIME) {
3045 /* start ctx time */
3047 ctx->timestamp = now;
3048 perf_cgroup_set_timestamp(task, ctx);
3052 * First go through the list and put on any pinned groups
3053 * in order to give them the best chance of going on.
3055 if (is_active & EVENT_PINNED)
3056 ctx_pinned_sched_in(ctx, cpuctx);
3058 /* Then walk through the lower prio flexible groups */
3059 if (is_active & EVENT_FLEXIBLE)
3060 ctx_flexible_sched_in(ctx, cpuctx);
3063 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
3064 enum event_type_t event_type,
3065 struct task_struct *task)
3067 struct perf_event_context *ctx = &cpuctx->ctx;
3069 ctx_sched_in(ctx, cpuctx, event_type, task);
3072 static void perf_event_context_sched_in(struct perf_event_context *ctx,
3073 struct task_struct *task)
3075 struct perf_cpu_context *cpuctx;
3077 cpuctx = __get_cpu_context(ctx);
3078 if (cpuctx->task_ctx == ctx)
3081 perf_ctx_lock(cpuctx, ctx);
3082 perf_pmu_disable(ctx->pmu);
3084 * We want to keep the following priority order:
3085 * cpu pinned (that don't need to move), task pinned,
3086 * cpu flexible, task flexible.
3088 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3089 perf_event_sched_in(cpuctx, ctx, task);
3090 perf_pmu_enable(ctx->pmu);
3091 perf_ctx_unlock(cpuctx, ctx);
3095 * Called from scheduler to add the events of the current task
3096 * with interrupts disabled.
3098 * We restore the event value and then enable it.
3100 * This does not protect us against NMI, but enable()
3101 * sets the enabled bit in the control field of event _before_
3102 * accessing the event control register. If a NMI hits, then it will
3103 * keep the event running.
3105 void __perf_event_task_sched_in(struct task_struct *prev,
3106 struct task_struct *task)
3108 struct perf_event_context *ctx;
3112 * If cgroup events exist on this CPU, then we need to check if we have
3113 * to switch in PMU state; cgroup event are system-wide mode only.
3115 * Since cgroup events are CPU events, we must schedule these in before
3116 * we schedule in the task events.
3118 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
3119 perf_cgroup_sched_in(prev, task);
3121 for_each_task_context_nr(ctxn) {
3122 ctx = task->perf_event_ctxp[ctxn];
3126 perf_event_context_sched_in(ctx, task);
3129 if (atomic_read(&nr_switch_events))
3130 perf_event_switch(task, prev, true);
3132 if (__this_cpu_read(perf_sched_cb_usages))
3133 perf_pmu_sched_task(prev, task, true);
3136 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
3138 u64 frequency = event->attr.sample_freq;
3139 u64 sec = NSEC_PER_SEC;
3140 u64 divisor, dividend;
3142 int count_fls, nsec_fls, frequency_fls, sec_fls;
3144 count_fls = fls64(count);
3145 nsec_fls = fls64(nsec);
3146 frequency_fls = fls64(frequency);
3150 * We got @count in @nsec, with a target of sample_freq HZ
3151 * the target period becomes:
3154 * period = -------------------
3155 * @nsec * sample_freq
3160 * Reduce accuracy by one bit such that @a and @b converge
3161 * to a similar magnitude.
3163 #define REDUCE_FLS(a, b) \
3165 if (a##_fls > b##_fls) { \
3175 * Reduce accuracy until either term fits in a u64, then proceed with
3176 * the other, so that finally we can do a u64/u64 division.
3178 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
3179 REDUCE_FLS(nsec, frequency);
3180 REDUCE_FLS(sec, count);
3183 if (count_fls + sec_fls > 64) {
3184 divisor = nsec * frequency;
3186 while (count_fls + sec_fls > 64) {
3187 REDUCE_FLS(count, sec);
3191 dividend = count * sec;
3193 dividend = count * sec;
3195 while (nsec_fls + frequency_fls > 64) {
3196 REDUCE_FLS(nsec, frequency);
3200 divisor = nsec * frequency;
3206 return div64_u64(dividend, divisor);
3209 static DEFINE_PER_CPU(int, perf_throttled_count);
3210 static DEFINE_PER_CPU(u64, perf_throttled_seq);
3212 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
3214 struct hw_perf_event *hwc = &event->hw;
3215 s64 period, sample_period;
3218 period = perf_calculate_period(event, nsec, count);
3220 delta = (s64)(period - hwc->sample_period);
3221 delta = (delta + 7) / 8; /* low pass filter */
3223 sample_period = hwc->sample_period + delta;
3228 hwc->sample_period = sample_period;
3230 if (local64_read(&hwc->period_left) > 8*sample_period) {
3232 event->pmu->stop(event, PERF_EF_UPDATE);
3234 local64_set(&hwc->period_left, 0);
3237 event->pmu->start(event, PERF_EF_RELOAD);
3242 * combine freq adjustment with unthrottling to avoid two passes over the
3243 * events. At the same time, make sure, having freq events does not change
3244 * the rate of unthrottling as that would introduce bias.
3246 static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
3249 struct perf_event *event;
3250 struct hw_perf_event *hwc;
3251 u64 now, period = TICK_NSEC;
3255 * only need to iterate over all events iff:
3256 * - context have events in frequency mode (needs freq adjust)
3257 * - there are events to unthrottle on this cpu
3259 if (!(ctx->nr_freq || needs_unthr))
3262 raw_spin_lock(&ctx->lock);
3263 perf_pmu_disable(ctx->pmu);
3265 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3266 if (event->state != PERF_EVENT_STATE_ACTIVE)
3269 if (!event_filter_match(event))
3272 perf_pmu_disable(event->pmu);
3276 if (hwc->interrupts == MAX_INTERRUPTS) {
3277 hwc->interrupts = 0;
3278 perf_log_throttle(event, 1);
3279 event->pmu->start(event, 0);
3282 if (!event->attr.freq || !event->attr.sample_freq)
3286 * stop the event and update event->count
3288 event->pmu->stop(event, PERF_EF_UPDATE);
3290 now = local64_read(&event->count);
3291 delta = now - hwc->freq_count_stamp;
3292 hwc->freq_count_stamp = now;
3296 * reload only if value has changed
3297 * we have stopped the event so tell that
3298 * to perf_adjust_period() to avoid stopping it
3302 perf_adjust_period(event, period, delta, false);
3304 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
3306 perf_pmu_enable(event->pmu);
3309 perf_pmu_enable(ctx->pmu);
3310 raw_spin_unlock(&ctx->lock);
3314 * Round-robin a context's events:
3316 static void rotate_ctx(struct perf_event_context *ctx)
3319 * Rotate the first entry last of non-pinned groups. Rotation might be
3320 * disabled by the inheritance code.
3322 if (!ctx->rotate_disable)
3323 list_rotate_left(&ctx->flexible_groups);
3326 static int perf_rotate_context(struct perf_cpu_context *cpuctx)
3328 struct perf_event_context *ctx = NULL;
3331 if (cpuctx->ctx.nr_events) {
3332 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
3336 ctx = cpuctx->task_ctx;
3337 if (ctx && ctx->nr_events) {
3338 if (ctx->nr_events != ctx->nr_active)
3345 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3346 perf_pmu_disable(cpuctx->ctx.pmu);
3348 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3350 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
3352 rotate_ctx(&cpuctx->ctx);
3356 perf_event_sched_in(cpuctx, ctx, current);
3358 perf_pmu_enable(cpuctx->ctx.pmu);
3359 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3365 void perf_event_task_tick(void)
3367 struct list_head *head = this_cpu_ptr(&active_ctx_list);
3368 struct perf_event_context *ctx, *tmp;
3371 WARN_ON(!irqs_disabled());
3373 __this_cpu_inc(perf_throttled_seq);
3374 throttled = __this_cpu_xchg(perf_throttled_count, 0);
3375 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
3377 list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
3378 perf_adjust_freq_unthr_context(ctx, throttled);
3381 static int event_enable_on_exec(struct perf_event *event,
3382 struct perf_event_context *ctx)
3384 if (!event->attr.enable_on_exec)
3387 event->attr.enable_on_exec = 0;
3388 if (event->state >= PERF_EVENT_STATE_INACTIVE)
3391 __perf_event_mark_enabled(event);
3397 * Enable all of a task's events that have been marked enable-on-exec.
3398 * This expects task == current.
3400 static void perf_event_enable_on_exec(int ctxn)
3402 struct perf_event_context *ctx, *clone_ctx = NULL;
3403 struct perf_cpu_context *cpuctx;
3404 struct perf_event *event;
3405 unsigned long flags;
3408 local_irq_save(flags);
3409 ctx = current->perf_event_ctxp[ctxn];
3410 if (!ctx || !ctx->nr_events)
3413 cpuctx = __get_cpu_context(ctx);
3414 perf_ctx_lock(cpuctx, ctx);
3415 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
3416 list_for_each_entry(event, &ctx->event_list, event_entry)
3417 enabled |= event_enable_on_exec(event, ctx);
3420 * Unclone and reschedule this context if we enabled any event.
3423 clone_ctx = unclone_ctx(ctx);
3424 ctx_resched(cpuctx, ctx);
3426 perf_ctx_unlock(cpuctx, ctx);
3429 local_irq_restore(flags);
3435 struct perf_read_data {
3436 struct perf_event *event;
3441 static int find_cpu_to_read(struct perf_event *event, int local_cpu)
3443 int event_cpu = event->oncpu;
3444 u16 local_pkg, event_pkg;
3446 if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) {
3447 event_pkg = topology_physical_package_id(event_cpu);
3448 local_pkg = topology_physical_package_id(local_cpu);
3450 if (event_pkg == local_pkg)
3458 * Cross CPU call to read the hardware event
3460 static void __perf_event_read(void *info)
3462 struct perf_read_data *data = info;
3463 struct perf_event *sub, *event = data->event;
3464 struct perf_event_context *ctx = event->ctx;
3465 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
3466 struct pmu *pmu = event->pmu;
3469 * If this is a task context, we need to check whether it is
3470 * the current task context of this cpu. If not it has been
3471 * scheduled out before the smp call arrived. In that case
3472 * event->count would have been updated to a recent sample
3473 * when the event was scheduled out.
3475 if (ctx->task && cpuctx->task_ctx != ctx)
3478 raw_spin_lock(&ctx->lock);
3479 if (ctx->is_active) {
3480 update_context_time(ctx);
3481 update_cgrp_time_from_event(event);
3484 update_event_times(event);
3485 if (event->state != PERF_EVENT_STATE_ACTIVE)
3494 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
3498 list_for_each_entry(sub, &event->sibling_list, group_entry) {
3499 update_event_times(sub);
3500 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
3502 * Use sibling's PMU rather than @event's since
3503 * sibling could be on different (eg: software) PMU.
3505 sub->pmu->read(sub);
3509 data->ret = pmu->commit_txn(pmu);
3512 raw_spin_unlock(&ctx->lock);
3515 static inline u64 perf_event_count(struct perf_event *event)
3517 if (event->pmu->count)
3518 return event->pmu->count(event);
3520 return __perf_event_count(event);
3524 * NMI-safe method to read a local event, that is an event that
3526 * - either for the current task, or for this CPU
3527 * - does not have inherit set, for inherited task events
3528 * will not be local and we cannot read them atomically
3529 * - must not have a pmu::count method
3531 u64 perf_event_read_local(struct perf_event *event)
3533 unsigned long flags;
3537 * Disabling interrupts avoids all counter scheduling (context
3538 * switches, timer based rotation and IPIs).
3540 local_irq_save(flags);
3542 /* If this is a per-task event, it must be for current */
3543 WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
3544 event->hw.target != current);
3546 /* If this is a per-CPU event, it must be for this CPU */
3547 WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
3548 event->cpu != smp_processor_id());
3551 * It must not be an event with inherit set, we cannot read
3552 * all child counters from atomic context.
3554 WARN_ON_ONCE(event->attr.inherit);
3557 * It must not have a pmu::count method, those are not
3560 WARN_ON_ONCE(event->pmu->count);
3563 * If the event is currently on this CPU, its either a per-task event,
3564 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3567 if (event->oncpu == smp_processor_id())
3568 event->pmu->read(event);
3570 val = local64_read(&event->count);
3571 local_irq_restore(flags);
3576 static int perf_event_read(struct perf_event *event, bool group)
3578 int ret = 0, cpu_to_read, local_cpu;
3581 * If event is enabled and currently active on a CPU, update the
3582 * value in the event structure:
3584 if (event->state == PERF_EVENT_STATE_ACTIVE) {
3585 struct perf_read_data data = {
3591 local_cpu = get_cpu();
3592 cpu_to_read = find_cpu_to_read(event, local_cpu);
3596 * Purposely ignore the smp_call_function_single() return
3599 * If event->oncpu isn't a valid CPU it means the event got
3600 * scheduled out and that will have updated the event count.
3602 * Therefore, either way, we'll have an up-to-date event count
3605 (void)smp_call_function_single(cpu_to_read, __perf_event_read, &data, 1);
3607 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
3608 struct perf_event_context *ctx = event->ctx;
3609 unsigned long flags;
3611 raw_spin_lock_irqsave(&ctx->lock, flags);
3613 * may read while context is not active
3614 * (e.g., thread is blocked), in that case
3615 * we cannot update context time
3617 if (ctx->is_active) {
3618 update_context_time(ctx);
3619 update_cgrp_time_from_event(event);
3622 update_group_times(event);
3624 update_event_times(event);
3625 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3632 * Initialize the perf_event context in a task_struct:
3634 static void __perf_event_init_context(struct perf_event_context *ctx)
3636 raw_spin_lock_init(&ctx->lock);
3637 mutex_init(&ctx->mutex);
3638 INIT_LIST_HEAD(&ctx->active_ctx_list);
3639 INIT_LIST_HEAD(&ctx->pinned_groups);
3640 INIT_LIST_HEAD(&ctx->flexible_groups);
3641 INIT_LIST_HEAD(&ctx->event_list);
3642 atomic_set(&ctx->refcount, 1);
3645 static struct perf_event_context *
3646 alloc_perf_context(struct pmu *pmu, struct task_struct *task)
3648 struct perf_event_context *ctx;
3650 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
3654 __perf_event_init_context(ctx);
3657 get_task_struct(task);
3664 static struct task_struct *
3665 find_lively_task_by_vpid(pid_t vpid)
3667 struct task_struct *task;
3673 task = find_task_by_vpid(vpid);
3675 get_task_struct(task);
3679 return ERR_PTR(-ESRCH);
3685 * Returns a matching context with refcount and pincount.
3687 static struct perf_event_context *
3688 find_get_context(struct pmu *pmu, struct task_struct *task,
3689 struct perf_event *event)
3691 struct perf_event_context *ctx, *clone_ctx = NULL;
3692 struct perf_cpu_context *cpuctx;
3693 void *task_ctx_data = NULL;
3694 unsigned long flags;
3696 int cpu = event->cpu;
3699 /* Must be root to operate on a CPU event: */
3700 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
3701 return ERR_PTR(-EACCES);
3704 * We could be clever and allow to attach a event to an
3705 * offline CPU and activate it when the CPU comes up, but
3708 if (!cpu_online(cpu))
3709 return ERR_PTR(-ENODEV);
3711 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
3720 ctxn = pmu->task_ctx_nr;
3724 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
3725 task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
3726 if (!task_ctx_data) {
3733 ctx = perf_lock_task_context(task, ctxn, &flags);
3735 clone_ctx = unclone_ctx(ctx);
3738 if (task_ctx_data && !ctx->task_ctx_data) {
3739 ctx->task_ctx_data = task_ctx_data;
3740 task_ctx_data = NULL;
3742 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3747 ctx = alloc_perf_context(pmu, task);
3752 if (task_ctx_data) {
3753 ctx->task_ctx_data = task_ctx_data;
3754 task_ctx_data = NULL;
3758 mutex_lock(&task->perf_event_mutex);
3760 * If it has already passed perf_event_exit_task().
3761 * we must see PF_EXITING, it takes this mutex too.
3763 if (task->flags & PF_EXITING)
3765 else if (task->perf_event_ctxp[ctxn])
3770 rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
3772 mutex_unlock(&task->perf_event_mutex);
3774 if (unlikely(err)) {
3783 kfree(task_ctx_data);
3787 kfree(task_ctx_data);
3788 return ERR_PTR(err);
3791 static void perf_event_free_filter(struct perf_event *event);
3792 static void perf_event_free_bpf_prog(struct perf_event *event);
3794 static void free_event_rcu(struct rcu_head *head)
3796 struct perf_event *event;
3798 event = container_of(head, struct perf_event, rcu_head);
3800 put_pid_ns(event->ns);
3801 perf_event_free_filter(event);
3805 static void ring_buffer_attach(struct perf_event *event,
3806 struct ring_buffer *rb);
3808 static void detach_sb_event(struct perf_event *event)
3810 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
3812 raw_spin_lock(&pel->lock);
3813 list_del_rcu(&event->sb_list);
3814 raw_spin_unlock(&pel->lock);
3817 static bool is_sb_event(struct perf_event *event)
3819 struct perf_event_attr *attr = &event->attr;
3824 if (event->attach_state & PERF_ATTACH_TASK)
3827 if (attr->mmap || attr->mmap_data || attr->mmap2 ||
3828 attr->comm || attr->comm_exec ||
3830 attr->context_switch)
3835 static void unaccount_pmu_sb_event(struct perf_event *event)
3837 if (is_sb_event(event))
3838 detach_sb_event(event);
3841 static void unaccount_event_cpu(struct perf_event *event, int cpu)
3846 if (is_cgroup_event(event))
3847 atomic_dec(&per_cpu(perf_cgroup_events, cpu));
3850 #ifdef CONFIG_NO_HZ_FULL
3851 static DEFINE_SPINLOCK(nr_freq_lock);
3854 static void unaccount_freq_event_nohz(void)
3856 #ifdef CONFIG_NO_HZ_FULL
3857 spin_lock(&nr_freq_lock);
3858 if (atomic_dec_and_test(&nr_freq_events))
3859 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
3860 spin_unlock(&nr_freq_lock);
3864 static void unaccount_freq_event(void)
3866 if (tick_nohz_full_enabled())
3867 unaccount_freq_event_nohz();
3869 atomic_dec(&nr_freq_events);
3872 static void unaccount_event(struct perf_event *event)
3879 if (event->attach_state & PERF_ATTACH_TASK)
3881 if (event->attr.mmap || event->attr.mmap_data)
3882 atomic_dec(&nr_mmap_events);
3883 if (event->attr.comm)
3884 atomic_dec(&nr_comm_events);
3885 if (event->attr.task)
3886 atomic_dec(&nr_task_events);
3887 if (event->attr.freq)
3888 unaccount_freq_event();
3889 if (event->attr.context_switch) {
3891 atomic_dec(&nr_switch_events);
3893 if (is_cgroup_event(event))
3895 if (has_branch_stack(event))
3899 if (!atomic_add_unless(&perf_sched_count, -1, 1))
3900 schedule_delayed_work(&perf_sched_work, HZ);
3903 unaccount_event_cpu(event, event->cpu);
3905 unaccount_pmu_sb_event(event);
3908 static void perf_sched_delayed(struct work_struct *work)
3910 mutex_lock(&perf_sched_mutex);
3911 if (atomic_dec_and_test(&perf_sched_count))
3912 static_branch_disable(&perf_sched_events);
3913 mutex_unlock(&perf_sched_mutex);
3917 * The following implement mutual exclusion of events on "exclusive" pmus
3918 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3919 * at a time, so we disallow creating events that might conflict, namely:
3921 * 1) cpu-wide events in the presence of per-task events,
3922 * 2) per-task events in the presence of cpu-wide events,
3923 * 3) two matching events on the same context.
3925 * The former two cases are handled in the allocation path (perf_event_alloc(),
3926 * _free_event()), the latter -- before the first perf_install_in_context().
3928 static int exclusive_event_init(struct perf_event *event)
3930 struct pmu *pmu = event->pmu;
3932 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3936 * Prevent co-existence of per-task and cpu-wide events on the
3937 * same exclusive pmu.
3939 * Negative pmu::exclusive_cnt means there are cpu-wide
3940 * events on this "exclusive" pmu, positive means there are
3943 * Since this is called in perf_event_alloc() path, event::ctx
3944 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3945 * to mean "per-task event", because unlike other attach states it
3946 * never gets cleared.
3948 if (event->attach_state & PERF_ATTACH_TASK) {
3949 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
3952 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
3959 static void exclusive_event_destroy(struct perf_event *event)
3961 struct pmu *pmu = event->pmu;
3963 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3966 /* see comment in exclusive_event_init() */
3967 if (event->attach_state & PERF_ATTACH_TASK)
3968 atomic_dec(&pmu->exclusive_cnt);
3970 atomic_inc(&pmu->exclusive_cnt);
3973 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
3975 if ((e1->pmu == e2->pmu) &&
3976 (e1->cpu == e2->cpu ||
3983 /* Called under the same ctx::mutex as perf_install_in_context() */
3984 static bool exclusive_event_installable(struct perf_event *event,
3985 struct perf_event_context *ctx)
3987 struct perf_event *iter_event;
3988 struct pmu *pmu = event->pmu;
3990 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3993 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
3994 if (exclusive_event_match(iter_event, event))
4001 static void perf_addr_filters_splice(struct perf_event *event,
4002 struct list_head *head);
4004 static void _free_event(struct perf_event *event)
4006 irq_work_sync(&event->pending);
4008 unaccount_event(event);
4012 * Can happen when we close an event with re-directed output.
4014 * Since we have a 0 refcount, perf_mmap_close() will skip
4015 * over us; possibly making our ring_buffer_put() the last.
4017 mutex_lock(&event->mmap_mutex);
4018 ring_buffer_attach(event, NULL);
4019 mutex_unlock(&event->mmap_mutex);
4022 if (is_cgroup_event(event))
4023 perf_detach_cgroup(event);
4025 if (!event->parent) {
4026 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
4027 put_callchain_buffers();
4030 perf_event_free_bpf_prog(event);
4031 perf_addr_filters_splice(event, NULL);
4032 kfree(event->addr_filters_offs);
4035 event->destroy(event);
4038 put_ctx(event->ctx);
4040 exclusive_event_destroy(event);
4041 module_put(event->pmu->module);
4043 call_rcu(&event->rcu_head, free_event_rcu);
4047 * Used to free events which have a known refcount of 1, such as in error paths
4048 * where the event isn't exposed yet and inherited events.
4050 static void free_event(struct perf_event *event)
4052 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
4053 "unexpected event refcount: %ld; ptr=%p\n",
4054 atomic_long_read(&event->refcount), event)) {
4055 /* leak to avoid use-after-free */
4063 * Remove user event from the owner task.
4065 static void perf_remove_from_owner(struct perf_event *event)
4067 struct task_struct *owner;
4071 * Matches the smp_store_release() in perf_event_exit_task(). If we
4072 * observe !owner it means the list deletion is complete and we can
4073 * indeed free this event, otherwise we need to serialize on
4074 * owner->perf_event_mutex.
4076 owner = lockless_dereference(event->owner);
4079 * Since delayed_put_task_struct() also drops the last
4080 * task reference we can safely take a new reference
4081 * while holding the rcu_read_lock().
4083 get_task_struct(owner);
4089 * If we're here through perf_event_exit_task() we're already
4090 * holding ctx->mutex which would be an inversion wrt. the
4091 * normal lock order.
4093 * However we can safely take this lock because its the child
4096 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
4099 * We have to re-check the event->owner field, if it is cleared
4100 * we raced with perf_event_exit_task(), acquiring the mutex
4101 * ensured they're done, and we can proceed with freeing the
4105 list_del_init(&event->owner_entry);
4106 smp_store_release(&event->owner, NULL);
4108 mutex_unlock(&owner->perf_event_mutex);
4109 put_task_struct(owner);
4113 static void put_event(struct perf_event *event)
4115 if (!atomic_long_dec_and_test(&event->refcount))
4122 * Kill an event dead; while event:refcount will preserve the event
4123 * object, it will not preserve its functionality. Once the last 'user'
4124 * gives up the object, we'll destroy the thing.
4126 int perf_event_release_kernel(struct perf_event *event)
4128 struct perf_event_context *ctx = event->ctx;
4129 struct perf_event *child, *tmp;
4132 * If we got here through err_file: fput(event_file); we will not have
4133 * attached to a context yet.
4136 WARN_ON_ONCE(event->attach_state &
4137 (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
4141 if (!is_kernel_event(event))
4142 perf_remove_from_owner(event);
4144 ctx = perf_event_ctx_lock(event);
4145 WARN_ON_ONCE(ctx->parent_ctx);
4146 perf_remove_from_context(event, DETACH_GROUP);
4148 raw_spin_lock_irq(&ctx->lock);
4150 * Mark this even as STATE_DEAD, there is no external reference to it
4153 * Anybody acquiring event->child_mutex after the below loop _must_
4154 * also see this, most importantly inherit_event() which will avoid
4155 * placing more children on the list.
4157 * Thus this guarantees that we will in fact observe and kill _ALL_
4160 event->state = PERF_EVENT_STATE_DEAD;
4161 raw_spin_unlock_irq(&ctx->lock);
4163 perf_event_ctx_unlock(event, ctx);
4166 mutex_lock(&event->child_mutex);
4167 list_for_each_entry(child, &event->child_list, child_list) {
4170 * Cannot change, child events are not migrated, see the
4171 * comment with perf_event_ctx_lock_nested().
4173 ctx = lockless_dereference(child->ctx);
4175 * Since child_mutex nests inside ctx::mutex, we must jump
4176 * through hoops. We start by grabbing a reference on the ctx.
4178 * Since the event cannot get freed while we hold the
4179 * child_mutex, the context must also exist and have a !0
4185 * Now that we have a ctx ref, we can drop child_mutex, and
4186 * acquire ctx::mutex without fear of it going away. Then we
4187 * can re-acquire child_mutex.
4189 mutex_unlock(&event->child_mutex);
4190 mutex_lock(&ctx->mutex);
4191 mutex_lock(&event->child_mutex);
4194 * Now that we hold ctx::mutex and child_mutex, revalidate our
4195 * state, if child is still the first entry, it didn't get freed
4196 * and we can continue doing so.
4198 tmp = list_first_entry_or_null(&event->child_list,
4199 struct perf_event, child_list);
4201 perf_remove_from_context(child, DETACH_GROUP);
4202 list_del(&child->child_list);
4205 * This matches the refcount bump in inherit_event();
4206 * this can't be the last reference.
4211 mutex_unlock(&event->child_mutex);
4212 mutex_unlock(&ctx->mutex);
4216 mutex_unlock(&event->child_mutex);
4219 put_event(event); /* Must be the 'last' reference */
4222 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
4225 * Called when the last reference to the file is gone.
4227 static int perf_release(struct inode *inode, struct file *file)
4229 perf_event_release_kernel(file->private_data);
4233 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
4235 struct perf_event *child;
4241 mutex_lock(&event->child_mutex);
4243 (void)perf_event_read(event, false);
4244 total += perf_event_count(event);
4246 *enabled += event->total_time_enabled +
4247 atomic64_read(&event->child_total_time_enabled);
4248 *running += event->total_time_running +
4249 atomic64_read(&event->child_total_time_running);
4251 list_for_each_entry(child, &event->child_list, child_list) {
4252 (void)perf_event_read(child, false);
4253 total += perf_event_count(child);
4254 *enabled += child->total_time_enabled;
4255 *running += child->total_time_running;
4257 mutex_unlock(&event->child_mutex);
4261 EXPORT_SYMBOL_GPL(perf_event_read_value);
4263 static int __perf_read_group_add(struct perf_event *leader,
4264 u64 read_format, u64 *values)
4266 struct perf_event *sub;
4267 int n = 1; /* skip @nr */
4270 ret = perf_event_read(leader, true);
4275 * Since we co-schedule groups, {enabled,running} times of siblings
4276 * will be identical to those of the leader, so we only publish one
4279 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
4280 values[n++] += leader->total_time_enabled +
4281 atomic64_read(&leader->child_total_time_enabled);
4284 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
4285 values[n++] += leader->total_time_running +
4286 atomic64_read(&leader->child_total_time_running);
4290 * Write {count,id} tuples for every sibling.
4292 values[n++] += perf_event_count(leader);
4293 if (read_format & PERF_FORMAT_ID)
4294 values[n++] = primary_event_id(leader);
4296 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
4297 values[n++] += perf_event_count(sub);
4298 if (read_format & PERF_FORMAT_ID)
4299 values[n++] = primary_event_id(sub);
4305 static int perf_read_group(struct perf_event *event,
4306 u64 read_format, char __user *buf)
4308 struct perf_event *leader = event->group_leader, *child;
4309 struct perf_event_context *ctx = leader->ctx;
4313 lockdep_assert_held(&ctx->mutex);
4315 values = kzalloc(event->read_size, GFP_KERNEL);
4319 values[0] = 1 + leader->nr_siblings;
4322 * By locking the child_mutex of the leader we effectively
4323 * lock the child list of all siblings.. XXX explain how.
4325 mutex_lock(&leader->child_mutex);
4327 ret = __perf_read_group_add(leader, read_format, values);
4331 list_for_each_entry(child, &leader->child_list, child_list) {
4332 ret = __perf_read_group_add(child, read_format, values);
4337 mutex_unlock(&leader->child_mutex);
4339 ret = event->read_size;
4340 if (copy_to_user(buf, values, event->read_size))
4345 mutex_unlock(&leader->child_mutex);
4351 static int perf_read_one(struct perf_event *event,
4352 u64 read_format, char __user *buf)
4354 u64 enabled, running;
4358 values[n++] = perf_event_read_value(event, &enabled, &running);
4359 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
4360 values[n++] = enabled;
4361 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
4362 values[n++] = running;
4363 if (read_format & PERF_FORMAT_ID)
4364 values[n++] = primary_event_id(event);
4366 if (copy_to_user(buf, values, n * sizeof(u64)))
4369 return n * sizeof(u64);
4372 static bool is_event_hup(struct perf_event *event)
4376 if (event->state > PERF_EVENT_STATE_EXIT)
4379 mutex_lock(&event->child_mutex);
4380 no_children = list_empty(&event->child_list);
4381 mutex_unlock(&event->child_mutex);
4386 * Read the performance event - simple non blocking version for now
4389 __perf_read(struct perf_event *event, char __user *buf, size_t count)
4391 u64 read_format = event->attr.read_format;
4395 * Return end-of-file for a read on a event that is in
4396 * error state (i.e. because it was pinned but it couldn't be
4397 * scheduled on to the CPU at some point).
4399 if (event->state == PERF_EVENT_STATE_ERROR)
4402 if (count < event->read_size)
4405 WARN_ON_ONCE(event->ctx->parent_ctx);
4406 if (read_format & PERF_FORMAT_GROUP)
4407 ret = perf_read_group(event, read_format, buf);
4409 ret = perf_read_one(event, read_format, buf);
4415 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
4417 struct perf_event *event = file->private_data;
4418 struct perf_event_context *ctx;
4421 ctx = perf_event_ctx_lock(event);
4422 ret = __perf_read(event, buf, count);
4423 perf_event_ctx_unlock(event, ctx);
4428 static unsigned int perf_poll(struct file *file, poll_table *wait)
4430 struct perf_event *event = file->private_data;
4431 struct ring_buffer *rb;
4432 unsigned int events = POLLHUP;
4434 poll_wait(file, &event->waitq, wait);
4436 if (is_event_hup(event))
4440 * Pin the event->rb by taking event->mmap_mutex; otherwise
4441 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4443 mutex_lock(&event->mmap_mutex);
4446 events = atomic_xchg(&rb->poll, 0);
4447 mutex_unlock(&event->mmap_mutex);
4451 static void _perf_event_reset(struct perf_event *event)
4453 (void)perf_event_read(event, false);
4454 local64_set(&event->count, 0);
4455 perf_event_update_userpage(event);
4459 * Holding the top-level event's child_mutex means that any
4460 * descendant process that has inherited this event will block
4461 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4462 * task existence requirements of perf_event_enable/disable.
4464 static void perf_event_for_each_child(struct perf_event *event,
4465 void (*func)(struct perf_event *))
4467 struct perf_event *child;
4469 WARN_ON_ONCE(event->ctx->parent_ctx);
4471 mutex_lock(&event->child_mutex);
4473 list_for_each_entry(child, &event->child_list, child_list)
4475 mutex_unlock(&event->child_mutex);
4478 static void perf_event_for_each(struct perf_event *event,
4479 void (*func)(struct perf_event *))
4481 struct perf_event_context *ctx = event->ctx;
4482 struct perf_event *sibling;
4484 lockdep_assert_held(&ctx->mutex);
4486 event = event->group_leader;
4488 perf_event_for_each_child(event, func);
4489 list_for_each_entry(sibling, &event->sibling_list, group_entry)
4490 perf_event_for_each_child(sibling, func);
4493 static void __perf_event_period(struct perf_event *event,
4494 struct perf_cpu_context *cpuctx,
4495 struct perf_event_context *ctx,
4498 u64 value = *((u64 *)info);
4501 if (event->attr.freq) {
4502 event->attr.sample_freq = value;
4504 event->attr.sample_period = value;
4505 event->hw.sample_period = value;
4508 active = (event->state == PERF_EVENT_STATE_ACTIVE);
4510 perf_pmu_disable(ctx->pmu);
4512 * We could be throttled; unthrottle now to avoid the tick
4513 * trying to unthrottle while we already re-started the event.
4515 if (event->hw.interrupts == MAX_INTERRUPTS) {
4516 event->hw.interrupts = 0;
4517 perf_log_throttle(event, 1);
4519 event->pmu->stop(event, PERF_EF_UPDATE);
4522 local64_set(&event->hw.period_left, 0);
4525 event->pmu->start(event, PERF_EF_RELOAD);
4526 perf_pmu_enable(ctx->pmu);
4530 static int perf_event_period(struct perf_event *event, u64 __user *arg)
4534 if (!is_sampling_event(event))
4537 if (copy_from_user(&value, arg, sizeof(value)))
4543 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
4546 event_function_call(event, __perf_event_period, &value);
4551 static const struct file_operations perf_fops;
4553 static inline int perf_fget_light(int fd, struct fd *p)
4555 struct fd f = fdget(fd);
4559 if (f.file->f_op != &perf_fops) {
4567 static int perf_event_set_output(struct perf_event *event,
4568 struct perf_event *output_event);
4569 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
4570 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd);
4572 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
4574 void (*func)(struct perf_event *);
4578 case PERF_EVENT_IOC_ENABLE:
4579 func = _perf_event_enable;
4581 case PERF_EVENT_IOC_DISABLE:
4582 func = _perf_event_disable;
4584 case PERF_EVENT_IOC_RESET:
4585 func = _perf_event_reset;
4588 case PERF_EVENT_IOC_REFRESH:
4589 return _perf_event_refresh(event, arg);
4591 case PERF_EVENT_IOC_PERIOD:
4592 return perf_event_period(event, (u64 __user *)arg);
4594 case PERF_EVENT_IOC_ID:
4596 u64 id = primary_event_id(event);
4598 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
4603 case PERF_EVENT_IOC_SET_OUTPUT:
4607 struct perf_event *output_event;
4609 ret = perf_fget_light(arg, &output);
4612 output_event = output.file->private_data;
4613 ret = perf_event_set_output(event, output_event);
4616 ret = perf_event_set_output(event, NULL);
4621 case PERF_EVENT_IOC_SET_FILTER:
4622 return perf_event_set_filter(event, (void __user *)arg);
4624 case PERF_EVENT_IOC_SET_BPF:
4625 return perf_event_set_bpf_prog(event, arg);
4627 case PERF_EVENT_IOC_PAUSE_OUTPUT: {
4628 struct ring_buffer *rb;
4631 rb = rcu_dereference(event->rb);
4632 if (!rb || !rb->nr_pages) {
4636 rb_toggle_paused(rb, !!arg);
4644 if (flags & PERF_IOC_FLAG_GROUP)
4645 perf_event_for_each(event, func);
4647 perf_event_for_each_child(event, func);
4652 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4654 struct perf_event *event = file->private_data;
4655 struct perf_event_context *ctx;
4658 ctx = perf_event_ctx_lock(event);
4659 ret = _perf_ioctl(event, cmd, arg);
4660 perf_event_ctx_unlock(event, ctx);
4665 #ifdef CONFIG_COMPAT
4666 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
4669 switch (_IOC_NR(cmd)) {
4670 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
4671 case _IOC_NR(PERF_EVENT_IOC_ID):
4672 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4673 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
4674 cmd &= ~IOCSIZE_MASK;
4675 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
4679 return perf_ioctl(file, cmd, arg);
4682 # define perf_compat_ioctl NULL
4685 int perf_event_task_enable(void)
4687 struct perf_event_context *ctx;
4688 struct perf_event *event;
4690 mutex_lock(¤t->perf_event_mutex);
4691 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4692 ctx = perf_event_ctx_lock(event);
4693 perf_event_for_each_child(event, _perf_event_enable);
4694 perf_event_ctx_unlock(event, ctx);
4696 mutex_unlock(¤t->perf_event_mutex);
4701 int perf_event_task_disable(void)
4703 struct perf_event_context *ctx;
4704 struct perf_event *event;
4706 mutex_lock(¤t->perf_event_mutex);
4707 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4708 ctx = perf_event_ctx_lock(event);
4709 perf_event_for_each_child(event, _perf_event_disable);
4710 perf_event_ctx_unlock(event, ctx);
4712 mutex_unlock(¤t->perf_event_mutex);
4717 static int perf_event_index(struct perf_event *event)
4719 if (event->hw.state & PERF_HES_STOPPED)
4722 if (event->state != PERF_EVENT_STATE_ACTIVE)
4725 return event->pmu->event_idx(event);
4728 static void calc_timer_values(struct perf_event *event,
4735 *now = perf_clock();
4736 ctx_time = event->shadow_ctx_time + *now;
4737 *enabled = ctx_time - event->tstamp_enabled;
4738 *running = ctx_time - event->tstamp_running;
4741 static void perf_event_init_userpage(struct perf_event *event)
4743 struct perf_event_mmap_page *userpg;
4744 struct ring_buffer *rb;
4747 rb = rcu_dereference(event->rb);
4751 userpg = rb->user_page;
4753 /* Allow new userspace to detect that bit 0 is deprecated */
4754 userpg->cap_bit0_is_deprecated = 1;
4755 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
4756 userpg->data_offset = PAGE_SIZE;
4757 userpg->data_size = perf_data_size(rb);
4763 void __weak arch_perf_update_userpage(
4764 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
4769 * Callers need to ensure there can be no nesting of this function, otherwise
4770 * the seqlock logic goes bad. We can not serialize this because the arch
4771 * code calls this from NMI context.
4773 void perf_event_update_userpage(struct perf_event *event)
4775 struct perf_event_mmap_page *userpg;
4776 struct ring_buffer *rb;
4777 u64 enabled, running, now;
4780 rb = rcu_dereference(event->rb);
4785 * compute total_time_enabled, total_time_running
4786 * based on snapshot values taken when the event
4787 * was last scheduled in.
4789 * we cannot simply called update_context_time()
4790 * because of locking issue as we can be called in
4793 calc_timer_values(event, &now, &enabled, &running);
4795 userpg = rb->user_page;
4797 * Disable preemption so as to not let the corresponding user-space
4798 * spin too long if we get preempted.
4803 userpg->index = perf_event_index(event);
4804 userpg->offset = perf_event_count(event);
4806 userpg->offset -= local64_read(&event->hw.prev_count);
4808 userpg->time_enabled = enabled +
4809 atomic64_read(&event->child_total_time_enabled);
4811 userpg->time_running = running +
4812 atomic64_read(&event->child_total_time_running);
4814 arch_perf_update_userpage(event, userpg, now);
4823 static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
4825 struct perf_event *event = vma->vm_file->private_data;
4826 struct ring_buffer *rb;
4827 int ret = VM_FAULT_SIGBUS;
4829 if (vmf->flags & FAULT_FLAG_MKWRITE) {
4830 if (vmf->pgoff == 0)
4836 rb = rcu_dereference(event->rb);
4840 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
4843 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
4847 get_page(vmf->page);
4848 vmf->page->mapping = vma->vm_file->f_mapping;
4849 vmf->page->index = vmf->pgoff;
4858 static void ring_buffer_attach(struct perf_event *event,
4859 struct ring_buffer *rb)
4861 struct ring_buffer *old_rb = NULL;
4862 unsigned long flags;
4866 * Should be impossible, we set this when removing
4867 * event->rb_entry and wait/clear when adding event->rb_entry.
4869 WARN_ON_ONCE(event->rcu_pending);
4872 spin_lock_irqsave(&old_rb->event_lock, flags);
4873 list_del_rcu(&event->rb_entry);
4874 spin_unlock_irqrestore(&old_rb->event_lock, flags);
4876 event->rcu_batches = get_state_synchronize_rcu();
4877 event->rcu_pending = 1;
4881 if (event->rcu_pending) {
4882 cond_synchronize_rcu(event->rcu_batches);
4883 event->rcu_pending = 0;
4886 spin_lock_irqsave(&rb->event_lock, flags);
4887 list_add_rcu(&event->rb_entry, &rb->event_list);
4888 spin_unlock_irqrestore(&rb->event_lock, flags);
4892 * Avoid racing with perf_mmap_close(AUX): stop the event
4893 * before swizzling the event::rb pointer; if it's getting
4894 * unmapped, its aux_mmap_count will be 0 and it won't
4895 * restart. See the comment in __perf_pmu_output_stop().
4897 * Data will inevitably be lost when set_output is done in
4898 * mid-air, but then again, whoever does it like this is
4899 * not in for the data anyway.
4902 perf_event_stop(event, 0);
4904 rcu_assign_pointer(event->rb, rb);
4907 ring_buffer_put(old_rb);
4909 * Since we detached before setting the new rb, so that we
4910 * could attach the new rb, we could have missed a wakeup.
4913 wake_up_all(&event->waitq);
4917 static void ring_buffer_wakeup(struct perf_event *event)
4919 struct ring_buffer *rb;
4922 rb = rcu_dereference(event->rb);
4924 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
4925 wake_up_all(&event->waitq);
4930 struct ring_buffer *ring_buffer_get(struct perf_event *event)
4932 struct ring_buffer *rb;
4935 rb = rcu_dereference(event->rb);
4937 if (!atomic_inc_not_zero(&rb->refcount))
4945 void ring_buffer_put(struct ring_buffer *rb)
4947 if (!atomic_dec_and_test(&rb->refcount))
4950 WARN_ON_ONCE(!list_empty(&rb->event_list));
4952 call_rcu(&rb->rcu_head, rb_free_rcu);
4955 static void perf_mmap_open(struct vm_area_struct *vma)
4957 struct perf_event *event = vma->vm_file->private_data;
4959 atomic_inc(&event->mmap_count);
4960 atomic_inc(&event->rb->mmap_count);
4963 atomic_inc(&event->rb->aux_mmap_count);
4965 if (event->pmu->event_mapped)
4966 event->pmu->event_mapped(event);
4969 static void perf_pmu_output_stop(struct perf_event *event);
4972 * A buffer can be mmap()ed multiple times; either directly through the same
4973 * event, or through other events by use of perf_event_set_output().
4975 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4976 * the buffer here, where we still have a VM context. This means we need
4977 * to detach all events redirecting to us.
4979 static void perf_mmap_close(struct vm_area_struct *vma)
4981 struct perf_event *event = vma->vm_file->private_data;
4983 struct ring_buffer *rb = ring_buffer_get(event);
4984 struct user_struct *mmap_user = rb->mmap_user;
4985 int mmap_locked = rb->mmap_locked;
4986 unsigned long size = perf_data_size(rb);
4988 if (event->pmu->event_unmapped)
4989 event->pmu->event_unmapped(event);
4992 * rb->aux_mmap_count will always drop before rb->mmap_count and
4993 * event->mmap_count, so it is ok to use event->mmap_mutex to
4994 * serialize with perf_mmap here.
4996 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
4997 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
4999 * Stop all AUX events that are writing to this buffer,
5000 * so that we can free its AUX pages and corresponding PMU
5001 * data. Note that after rb::aux_mmap_count dropped to zero,
5002 * they won't start any more (see perf_aux_output_begin()).
5004 perf_pmu_output_stop(event);
5006 /* now it's safe to free the pages */
5007 atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm);
5008 vma->vm_mm->pinned_vm -= rb->aux_mmap_locked;
5010 /* this has to be the last one */
5012 WARN_ON_ONCE(atomic_read(&rb->aux_refcount));
5014 mutex_unlock(&event->mmap_mutex);
5017 atomic_dec(&rb->mmap_count);
5019 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
5022 ring_buffer_attach(event, NULL);
5023 mutex_unlock(&event->mmap_mutex);
5025 /* If there's still other mmap()s of this buffer, we're done. */
5026 if (atomic_read(&rb->mmap_count))
5030 * No other mmap()s, detach from all other events that might redirect
5031 * into the now unreachable buffer. Somewhat complicated by the
5032 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5036 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
5037 if (!atomic_long_inc_not_zero(&event->refcount)) {
5039 * This event is en-route to free_event() which will
5040 * detach it and remove it from the list.
5046 mutex_lock(&event->mmap_mutex);
5048 * Check we didn't race with perf_event_set_output() which can
5049 * swizzle the rb from under us while we were waiting to
5050 * acquire mmap_mutex.
5052 * If we find a different rb; ignore this event, a next
5053 * iteration will no longer find it on the list. We have to
5054 * still restart the iteration to make sure we're not now
5055 * iterating the wrong list.
5057 if (event->rb == rb)
5058 ring_buffer_attach(event, NULL);
5060 mutex_unlock(&event->mmap_mutex);
5064 * Restart the iteration; either we're on the wrong list or
5065 * destroyed its integrity by doing a deletion.
5072 * It could be there's still a few 0-ref events on the list; they'll
5073 * get cleaned up by free_event() -- they'll also still have their
5074 * ref on the rb and will free it whenever they are done with it.
5076 * Aside from that, this buffer is 'fully' detached and unmapped,
5077 * undo the VM accounting.
5080 atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
5081 vma->vm_mm->pinned_vm -= mmap_locked;
5082 free_uid(mmap_user);
5085 ring_buffer_put(rb); /* could be last */
5088 static const struct vm_operations_struct perf_mmap_vmops = {
5089 .open = perf_mmap_open,
5090 .close = perf_mmap_close, /* non mergable */
5091 .fault = perf_mmap_fault,
5092 .page_mkwrite = perf_mmap_fault,
5095 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
5097 struct perf_event *event = file->private_data;
5098 unsigned long user_locked, user_lock_limit;
5099 struct user_struct *user = current_user();
5100 unsigned long locked, lock_limit;
5101 struct ring_buffer *rb = NULL;
5102 unsigned long vma_size;
5103 unsigned long nr_pages;
5104 long user_extra = 0, extra = 0;
5105 int ret = 0, flags = 0;
5108 * Don't allow mmap() of inherited per-task counters. This would
5109 * create a performance issue due to all children writing to the
5112 if (event->cpu == -1 && event->attr.inherit)
5115 if (!(vma->vm_flags & VM_SHARED))
5118 vma_size = vma->vm_end - vma->vm_start;
5120 if (vma->vm_pgoff == 0) {
5121 nr_pages = (vma_size / PAGE_SIZE) - 1;
5124 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5125 * mapped, all subsequent mappings should have the same size
5126 * and offset. Must be above the normal perf buffer.
5128 u64 aux_offset, aux_size;
5133 nr_pages = vma_size / PAGE_SIZE;
5135 mutex_lock(&event->mmap_mutex);
5142 aux_offset = ACCESS_ONCE(rb->user_page->aux_offset);
5143 aux_size = ACCESS_ONCE(rb->user_page->aux_size);
5145 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
5148 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
5151 /* already mapped with a different offset */
5152 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
5155 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
5158 /* already mapped with a different size */
5159 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
5162 if (!is_power_of_2(nr_pages))
5165 if (!atomic_inc_not_zero(&rb->mmap_count))
5168 if (rb_has_aux(rb)) {
5169 atomic_inc(&rb->aux_mmap_count);
5174 atomic_set(&rb->aux_mmap_count, 1);
5175 user_extra = nr_pages;
5181 * If we have rb pages ensure they're a power-of-two number, so we
5182 * can do bitmasks instead of modulo.
5184 if (nr_pages != 0 && !is_power_of_2(nr_pages))
5187 if (vma_size != PAGE_SIZE * (1 + nr_pages))
5190 WARN_ON_ONCE(event->ctx->parent_ctx);
5192 mutex_lock(&event->mmap_mutex);
5194 if (event->rb->nr_pages != nr_pages) {
5199 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
5201 * Raced against perf_mmap_close() through
5202 * perf_event_set_output(). Try again, hope for better
5205 mutex_unlock(&event->mmap_mutex);
5212 user_extra = nr_pages + 1;
5215 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
5218 * Increase the limit linearly with more CPUs:
5220 user_lock_limit *= num_online_cpus();
5222 user_locked = atomic_long_read(&user->locked_vm) + user_extra;
5224 if (user_locked > user_lock_limit)
5225 extra = user_locked - user_lock_limit;
5227 lock_limit = rlimit(RLIMIT_MEMLOCK);
5228 lock_limit >>= PAGE_SHIFT;
5229 locked = vma->vm_mm->pinned_vm + extra;
5231 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
5232 !capable(CAP_IPC_LOCK)) {
5237 WARN_ON(!rb && event->rb);
5239 if (vma->vm_flags & VM_WRITE)
5240 flags |= RING_BUFFER_WRITABLE;
5243 rb = rb_alloc(nr_pages,
5244 event->attr.watermark ? event->attr.wakeup_watermark : 0,
5252 atomic_set(&rb->mmap_count, 1);
5253 rb->mmap_user = get_current_user();
5254 rb->mmap_locked = extra;
5256 ring_buffer_attach(event, rb);
5258 perf_event_init_userpage(event);
5259 perf_event_update_userpage(event);
5261 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
5262 event->attr.aux_watermark, flags);
5264 rb->aux_mmap_locked = extra;
5269 atomic_long_add(user_extra, &user->locked_vm);
5270 vma->vm_mm->pinned_vm += extra;
5272 atomic_inc(&event->mmap_count);
5274 atomic_dec(&rb->mmap_count);
5277 mutex_unlock(&event->mmap_mutex);
5280 * Since pinned accounting is per vm we cannot allow fork() to copy our
5283 vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
5284 vma->vm_ops = &perf_mmap_vmops;
5286 if (event->pmu->event_mapped)
5287 event->pmu->event_mapped(event);
5292 static int perf_fasync(int fd, struct file *filp, int on)
5294 struct inode *inode = file_inode(filp);
5295 struct perf_event *event = filp->private_data;
5299 retval = fasync_helper(fd, filp, on, &event->fasync);
5300 inode_unlock(inode);
5308 static const struct file_operations perf_fops = {
5309 .llseek = no_llseek,
5310 .release = perf_release,
5313 .unlocked_ioctl = perf_ioctl,
5314 .compat_ioctl = perf_compat_ioctl,
5316 .fasync = perf_fasync,
5322 * If there's data, ensure we set the poll() state and publish everything
5323 * to user-space before waking everybody up.
5326 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
5328 /* only the parent has fasync state */
5330 event = event->parent;
5331 return &event->fasync;
5334 void perf_event_wakeup(struct perf_event *event)
5336 ring_buffer_wakeup(event);
5338 if (event->pending_kill) {
5339 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
5340 event->pending_kill = 0;
5344 static void perf_pending_event(struct irq_work *entry)
5346 struct perf_event *event = container_of(entry,
5347 struct perf_event, pending);
5350 rctx = perf_swevent_get_recursion_context();
5352 * If we 'fail' here, that's OK, it means recursion is already disabled
5353 * and we won't recurse 'further'.
5356 if (event->pending_disable) {
5357 event->pending_disable = 0;
5358 perf_event_disable_local(event);
5361 if (event->pending_wakeup) {
5362 event->pending_wakeup = 0;
5363 perf_event_wakeup(event);
5367 perf_swevent_put_recursion_context(rctx);
5371 * We assume there is only KVM supporting the callbacks.
5372 * Later on, we might change it to a list if there is
5373 * another virtualization implementation supporting the callbacks.
5375 struct perf_guest_info_callbacks *perf_guest_cbs;
5377 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5379 perf_guest_cbs = cbs;
5382 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
5384 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5386 perf_guest_cbs = NULL;
5389 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
5392 perf_output_sample_regs(struct perf_output_handle *handle,
5393 struct pt_regs *regs, u64 mask)
5396 DECLARE_BITMAP(_mask, 64);
5398 bitmap_from_u64(_mask, mask);
5399 for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) {
5402 val = perf_reg_value(regs, bit);
5403 perf_output_put(handle, val);
5407 static void perf_sample_regs_user(struct perf_regs *regs_user,
5408 struct pt_regs *regs,
5409 struct pt_regs *regs_user_copy)
5411 if (user_mode(regs)) {
5412 regs_user->abi = perf_reg_abi(current);
5413 regs_user->regs = regs;
5414 } else if (current->mm) {
5415 perf_get_regs_user(regs_user, regs, regs_user_copy);
5417 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
5418 regs_user->regs = NULL;
5422 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
5423 struct pt_regs *regs)
5425 regs_intr->regs = regs;
5426 regs_intr->abi = perf_reg_abi(current);
5431 * Get remaining task size from user stack pointer.
5433 * It'd be better to take stack vma map and limit this more
5434 * precisly, but there's no way to get it safely under interrupt,
5435 * so using TASK_SIZE as limit.
5437 static u64 perf_ustack_task_size(struct pt_regs *regs)
5439 unsigned long addr = perf_user_stack_pointer(regs);
5441 if (!addr || addr >= TASK_SIZE)
5444 return TASK_SIZE - addr;
5448 perf_sample_ustack_size(u16 stack_size, u16 header_size,
5449 struct pt_regs *regs)
5453 /* No regs, no stack pointer, no dump. */
5458 * Check if we fit in with the requested stack size into the:
5460 * If we don't, we limit the size to the TASK_SIZE.
5462 * - remaining sample size
5463 * If we don't, we customize the stack size to
5464 * fit in to the remaining sample size.
5467 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
5468 stack_size = min(stack_size, (u16) task_size);
5470 /* Current header size plus static size and dynamic size. */
5471 header_size += 2 * sizeof(u64);
5473 /* Do we fit in with the current stack dump size? */
5474 if ((u16) (header_size + stack_size) < header_size) {
5476 * If we overflow the maximum size for the sample,
5477 * we customize the stack dump size to fit in.
5479 stack_size = USHRT_MAX - header_size - sizeof(u64);
5480 stack_size = round_up(stack_size, sizeof(u64));
5487 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
5488 struct pt_regs *regs)
5490 /* Case of a kernel thread, nothing to dump */
5493 perf_output_put(handle, size);
5502 * - the size requested by user or the best one we can fit
5503 * in to the sample max size
5505 * - user stack dump data
5507 * - the actual dumped size
5511 perf_output_put(handle, dump_size);
5514 sp = perf_user_stack_pointer(regs);
5515 rem = __output_copy_user(handle, (void *) sp, dump_size);
5516 dyn_size = dump_size - rem;
5518 perf_output_skip(handle, rem);
5521 perf_output_put(handle, dyn_size);
5525 static void __perf_event_header__init_id(struct perf_event_header *header,
5526 struct perf_sample_data *data,
5527 struct perf_event *event)
5529 u64 sample_type = event->attr.sample_type;
5531 data->type = sample_type;
5532 header->size += event->id_header_size;
5534 if (sample_type & PERF_SAMPLE_TID) {
5535 /* namespace issues */
5536 data->tid_entry.pid = perf_event_pid(event, current);
5537 data->tid_entry.tid = perf_event_tid(event, current);
5540 if (sample_type & PERF_SAMPLE_TIME)
5541 data->time = perf_event_clock(event);
5543 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
5544 data->id = primary_event_id(event);
5546 if (sample_type & PERF_SAMPLE_STREAM_ID)
5547 data->stream_id = event->id;
5549 if (sample_type & PERF_SAMPLE_CPU) {
5550 data->cpu_entry.cpu = raw_smp_processor_id();
5551 data->cpu_entry.reserved = 0;
5555 void perf_event_header__init_id(struct perf_event_header *header,
5556 struct perf_sample_data *data,
5557 struct perf_event *event)
5559 if (event->attr.sample_id_all)
5560 __perf_event_header__init_id(header, data, event);
5563 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
5564 struct perf_sample_data *data)
5566 u64 sample_type = data->type;
5568 if (sample_type & PERF_SAMPLE_TID)
5569 perf_output_put(handle, data->tid_entry);
5571 if (sample_type & PERF_SAMPLE_TIME)
5572 perf_output_put(handle, data->time);
5574 if (sample_type & PERF_SAMPLE_ID)
5575 perf_output_put(handle, data->id);
5577 if (sample_type & PERF_SAMPLE_STREAM_ID)
5578 perf_output_put(handle, data->stream_id);
5580 if (sample_type & PERF_SAMPLE_CPU)
5581 perf_output_put(handle, data->cpu_entry);
5583 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5584 perf_output_put(handle, data->id);
5587 void perf_event__output_id_sample(struct perf_event *event,
5588 struct perf_output_handle *handle,
5589 struct perf_sample_data *sample)
5591 if (event->attr.sample_id_all)
5592 __perf_event__output_id_sample(handle, sample);
5595 static void perf_output_read_one(struct perf_output_handle *handle,
5596 struct perf_event *event,
5597 u64 enabled, u64 running)
5599 u64 read_format = event->attr.read_format;
5603 values[n++] = perf_event_count(event);
5604 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5605 values[n++] = enabled +
5606 atomic64_read(&event->child_total_time_enabled);
5608 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5609 values[n++] = running +
5610 atomic64_read(&event->child_total_time_running);
5612 if (read_format & PERF_FORMAT_ID)
5613 values[n++] = primary_event_id(event);
5615 __output_copy(handle, values, n * sizeof(u64));
5619 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5621 static void perf_output_read_group(struct perf_output_handle *handle,
5622 struct perf_event *event,
5623 u64 enabled, u64 running)
5625 struct perf_event *leader = event->group_leader, *sub;
5626 u64 read_format = event->attr.read_format;
5630 values[n++] = 1 + leader->nr_siblings;
5632 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5633 values[n++] = enabled;
5635 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5636 values[n++] = running;
5638 if (leader != event)
5639 leader->pmu->read(leader);
5641 values[n++] = perf_event_count(leader);
5642 if (read_format & PERF_FORMAT_ID)
5643 values[n++] = primary_event_id(leader);
5645 __output_copy(handle, values, n * sizeof(u64));
5647 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
5650 if ((sub != event) &&
5651 (sub->state == PERF_EVENT_STATE_ACTIVE))
5652 sub->pmu->read(sub);
5654 values[n++] = perf_event_count(sub);
5655 if (read_format & PERF_FORMAT_ID)
5656 values[n++] = primary_event_id(sub);
5658 __output_copy(handle, values, n * sizeof(u64));
5662 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5663 PERF_FORMAT_TOTAL_TIME_RUNNING)
5665 static void perf_output_read(struct perf_output_handle *handle,
5666 struct perf_event *event)
5668 u64 enabled = 0, running = 0, now;
5669 u64 read_format = event->attr.read_format;
5672 * compute total_time_enabled, total_time_running
5673 * based on snapshot values taken when the event
5674 * was last scheduled in.
5676 * we cannot simply called update_context_time()
5677 * because of locking issue as we are called in
5680 if (read_format & PERF_FORMAT_TOTAL_TIMES)
5681 calc_timer_values(event, &now, &enabled, &running);
5683 if (event->attr.read_format & PERF_FORMAT_GROUP)
5684 perf_output_read_group(handle, event, enabled, running);
5686 perf_output_read_one(handle, event, enabled, running);
5689 void perf_output_sample(struct perf_output_handle *handle,
5690 struct perf_event_header *header,
5691 struct perf_sample_data *data,
5692 struct perf_event *event)
5694 u64 sample_type = data->type;
5696 perf_output_put(handle, *header);
5698 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5699 perf_output_put(handle, data->id);
5701 if (sample_type & PERF_SAMPLE_IP)
5702 perf_output_put(handle, data->ip);
5704 if (sample_type & PERF_SAMPLE_TID)
5705 perf_output_put(handle, data->tid_entry);
5707 if (sample_type & PERF_SAMPLE_TIME)
5708 perf_output_put(handle, data->time);
5710 if (sample_type & PERF_SAMPLE_ADDR)
5711 perf_output_put(handle, data->addr);
5713 if (sample_type & PERF_SAMPLE_ID)
5714 perf_output_put(handle, data->id);
5716 if (sample_type & PERF_SAMPLE_STREAM_ID)
5717 perf_output_put(handle, data->stream_id);
5719 if (sample_type & PERF_SAMPLE_CPU)
5720 perf_output_put(handle, data->cpu_entry);
5722 if (sample_type & PERF_SAMPLE_PERIOD)
5723 perf_output_put(handle, data->period);
5725 if (sample_type & PERF_SAMPLE_READ)
5726 perf_output_read(handle, event);
5728 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5729 if (data->callchain) {
5732 if (data->callchain)
5733 size += data->callchain->nr;
5735 size *= sizeof(u64);
5737 __output_copy(handle, data->callchain, size);
5740 perf_output_put(handle, nr);
5744 if (sample_type & PERF_SAMPLE_RAW) {
5745 struct perf_raw_record *raw = data->raw;
5748 struct perf_raw_frag *frag = &raw->frag;
5750 perf_output_put(handle, raw->size);
5753 __output_custom(handle, frag->copy,
5754 frag->data, frag->size);
5756 __output_copy(handle, frag->data,
5759 if (perf_raw_frag_last(frag))
5764 __output_skip(handle, NULL, frag->pad);
5770 .size = sizeof(u32),
5773 perf_output_put(handle, raw);
5777 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5778 if (data->br_stack) {
5781 size = data->br_stack->nr
5782 * sizeof(struct perf_branch_entry);
5784 perf_output_put(handle, data->br_stack->nr);
5785 perf_output_copy(handle, data->br_stack->entries, size);
5788 * we always store at least the value of nr
5791 perf_output_put(handle, nr);
5795 if (sample_type & PERF_SAMPLE_REGS_USER) {
5796 u64 abi = data->regs_user.abi;
5799 * If there are no regs to dump, notice it through
5800 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5802 perf_output_put(handle, abi);
5805 u64 mask = event->attr.sample_regs_user;
5806 perf_output_sample_regs(handle,
5807 data->regs_user.regs,
5812 if (sample_type & PERF_SAMPLE_STACK_USER) {
5813 perf_output_sample_ustack(handle,
5814 data->stack_user_size,
5815 data->regs_user.regs);
5818 if (sample_type & PERF_SAMPLE_WEIGHT)
5819 perf_output_put(handle, data->weight);
5821 if (sample_type & PERF_SAMPLE_DATA_SRC)
5822 perf_output_put(handle, data->data_src.val);
5824 if (sample_type & PERF_SAMPLE_TRANSACTION)
5825 perf_output_put(handle, data->txn);
5827 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5828 u64 abi = data->regs_intr.abi;
5830 * If there are no regs to dump, notice it through
5831 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5833 perf_output_put(handle, abi);
5836 u64 mask = event->attr.sample_regs_intr;
5838 perf_output_sample_regs(handle,
5839 data->regs_intr.regs,
5844 if (!event->attr.watermark) {
5845 int wakeup_events = event->attr.wakeup_events;
5847 if (wakeup_events) {
5848 struct ring_buffer *rb = handle->rb;
5849 int events = local_inc_return(&rb->events);
5851 if (events >= wakeup_events) {
5852 local_sub(wakeup_events, &rb->events);
5853 local_inc(&rb->wakeup);
5859 void perf_prepare_sample(struct perf_event_header *header,
5860 struct perf_sample_data *data,
5861 struct perf_event *event,
5862 struct pt_regs *regs)
5864 u64 sample_type = event->attr.sample_type;
5866 header->type = PERF_RECORD_SAMPLE;
5867 header->size = sizeof(*header) + event->header_size;
5870 header->misc |= perf_misc_flags(regs);
5872 __perf_event_header__init_id(header, data, event);
5874 if (sample_type & PERF_SAMPLE_IP)
5875 data->ip = perf_instruction_pointer(regs);
5877 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5880 data->callchain = perf_callchain(event, regs);
5882 if (data->callchain)
5883 size += data->callchain->nr;
5885 header->size += size * sizeof(u64);
5888 if (sample_type & PERF_SAMPLE_RAW) {
5889 struct perf_raw_record *raw = data->raw;
5893 struct perf_raw_frag *frag = &raw->frag;
5898 if (perf_raw_frag_last(frag))
5903 size = round_up(sum + sizeof(u32), sizeof(u64));
5904 raw->size = size - sizeof(u32);
5905 frag->pad = raw->size - sum;
5910 header->size += size;
5913 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5914 int size = sizeof(u64); /* nr */
5915 if (data->br_stack) {
5916 size += data->br_stack->nr
5917 * sizeof(struct perf_branch_entry);
5919 header->size += size;
5922 if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
5923 perf_sample_regs_user(&data->regs_user, regs,
5924 &data->regs_user_copy);
5926 if (sample_type & PERF_SAMPLE_REGS_USER) {
5927 /* regs dump ABI info */
5928 int size = sizeof(u64);
5930 if (data->regs_user.regs) {
5931 u64 mask = event->attr.sample_regs_user;
5932 size += hweight64(mask) * sizeof(u64);
5935 header->size += size;
5938 if (sample_type & PERF_SAMPLE_STACK_USER) {
5940 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5941 * processed as the last one or have additional check added
5942 * in case new sample type is added, because we could eat
5943 * up the rest of the sample size.
5945 u16 stack_size = event->attr.sample_stack_user;
5946 u16 size = sizeof(u64);
5948 stack_size = perf_sample_ustack_size(stack_size, header->size,
5949 data->regs_user.regs);
5952 * If there is something to dump, add space for the dump
5953 * itself and for the field that tells the dynamic size,
5954 * which is how many have been actually dumped.
5957 size += sizeof(u64) + stack_size;
5959 data->stack_user_size = stack_size;
5960 header->size += size;
5963 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5964 /* regs dump ABI info */
5965 int size = sizeof(u64);
5967 perf_sample_regs_intr(&data->regs_intr, regs);
5969 if (data->regs_intr.regs) {
5970 u64 mask = event->attr.sample_regs_intr;
5972 size += hweight64(mask) * sizeof(u64);
5975 header->size += size;
5979 static void __always_inline
5980 __perf_event_output(struct perf_event *event,
5981 struct perf_sample_data *data,
5982 struct pt_regs *regs,
5983 int (*output_begin)(struct perf_output_handle *,
5984 struct perf_event *,
5987 struct perf_output_handle handle;
5988 struct perf_event_header header;
5990 /* protect the callchain buffers */
5993 perf_prepare_sample(&header, data, event, regs);
5995 if (output_begin(&handle, event, header.size))
5998 perf_output_sample(&handle, &header, data, event);
6000 perf_output_end(&handle);
6007 perf_event_output_forward(struct perf_event *event,
6008 struct perf_sample_data *data,
6009 struct pt_regs *regs)
6011 __perf_event_output(event, data, regs, perf_output_begin_forward);
6015 perf_event_output_backward(struct perf_event *event,
6016 struct perf_sample_data *data,
6017 struct pt_regs *regs)
6019 __perf_event_output(event, data, regs, perf_output_begin_backward);
6023 perf_event_output(struct perf_event *event,
6024 struct perf_sample_data *data,
6025 struct pt_regs *regs)
6027 __perf_event_output(event, data, regs, perf_output_begin);
6034 struct perf_read_event {
6035 struct perf_event_header header;
6042 perf_event_read_event(struct perf_event *event,
6043 struct task_struct *task)
6045 struct perf_output_handle handle;
6046 struct perf_sample_data sample;
6047 struct perf_read_event read_event = {
6049 .type = PERF_RECORD_READ,
6051 .size = sizeof(read_event) + event->read_size,
6053 .pid = perf_event_pid(event, task),
6054 .tid = perf_event_tid(event, task),
6058 perf_event_header__init_id(&read_event.header, &sample, event);
6059 ret = perf_output_begin(&handle, event, read_event.header.size);
6063 perf_output_put(&handle, read_event);
6064 perf_output_read(&handle, event);
6065 perf_event__output_id_sample(event, &handle, &sample);
6067 perf_output_end(&handle);
6070 typedef void (perf_iterate_f)(struct perf_event *event, void *data);
6073 perf_iterate_ctx(struct perf_event_context *ctx,
6074 perf_iterate_f output,
6075 void *data, bool all)
6077 struct perf_event *event;
6079 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
6081 if (event->state < PERF_EVENT_STATE_INACTIVE)
6083 if (!event_filter_match(event))
6087 output(event, data);
6091 static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
6093 struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
6094 struct perf_event *event;
6096 list_for_each_entry_rcu(event, &pel->list, sb_list) {
6098 * Skip events that are not fully formed yet; ensure that
6099 * if we observe event->ctx, both event and ctx will be
6100 * complete enough. See perf_install_in_context().
6102 if (!smp_load_acquire(&event->ctx))
6105 if (event->state < PERF_EVENT_STATE_INACTIVE)
6107 if (!event_filter_match(event))
6109 output(event, data);
6114 * Iterate all events that need to receive side-band events.
6116 * For new callers; ensure that account_pmu_sb_event() includes
6117 * your event, otherwise it might not get delivered.
6120 perf_iterate_sb(perf_iterate_f output, void *data,
6121 struct perf_event_context *task_ctx)
6123 struct perf_event_context *ctx;
6130 * If we have task_ctx != NULL we only notify the task context itself.
6131 * The task_ctx is set only for EXIT events before releasing task
6135 perf_iterate_ctx(task_ctx, output, data, false);
6139 perf_iterate_sb_cpu(output, data);
6141 for_each_task_context_nr(ctxn) {
6142 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6144 perf_iterate_ctx(ctx, output, data, false);
6152 * Clear all file-based filters at exec, they'll have to be
6153 * re-instated when/if these objects are mmapped again.
6155 static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
6157 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6158 struct perf_addr_filter *filter;
6159 unsigned int restart = 0, count = 0;
6160 unsigned long flags;
6162 if (!has_addr_filter(event))
6165 raw_spin_lock_irqsave(&ifh->lock, flags);
6166 list_for_each_entry(filter, &ifh->list, entry) {
6167 if (filter->inode) {
6168 event->addr_filters_offs[count] = 0;
6176 event->addr_filters_gen++;
6177 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6180 perf_event_stop(event, 1);
6183 void perf_event_exec(void)
6185 struct perf_event_context *ctx;
6189 for_each_task_context_nr(ctxn) {
6190 ctx = current->perf_event_ctxp[ctxn];
6194 perf_event_enable_on_exec(ctxn);
6196 perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL,
6202 struct remote_output {
6203 struct ring_buffer *rb;
6207 static void __perf_event_output_stop(struct perf_event *event, void *data)
6209 struct perf_event *parent = event->parent;
6210 struct remote_output *ro = data;
6211 struct ring_buffer *rb = ro->rb;
6212 struct stop_event_data sd = {
6216 if (!has_aux(event))
6223 * In case of inheritance, it will be the parent that links to the
6224 * ring-buffer, but it will be the child that's actually using it.
6226 * We are using event::rb to determine if the event should be stopped,
6227 * however this may race with ring_buffer_attach() (through set_output),
6228 * which will make us skip the event that actually needs to be stopped.
6229 * So ring_buffer_attach() has to stop an aux event before re-assigning
6232 if (rcu_dereference(parent->rb) == rb)
6233 ro->err = __perf_event_stop(&sd);
6236 static int __perf_pmu_output_stop(void *info)
6238 struct perf_event *event = info;
6239 struct pmu *pmu = event->pmu;
6240 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
6241 struct remote_output ro = {
6246 perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
6247 if (cpuctx->task_ctx)
6248 perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
6255 static void perf_pmu_output_stop(struct perf_event *event)
6257 struct perf_event *iter;
6262 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
6264 * For per-CPU events, we need to make sure that neither they
6265 * nor their children are running; for cpu==-1 events it's
6266 * sufficient to stop the event itself if it's active, since
6267 * it can't have children.
6271 cpu = READ_ONCE(iter->oncpu);
6276 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
6277 if (err == -EAGAIN) {
6286 * task tracking -- fork/exit
6288 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6291 struct perf_task_event {
6292 struct task_struct *task;
6293 struct perf_event_context *task_ctx;
6296 struct perf_event_header header;
6306 static int perf_event_task_match(struct perf_event *event)
6308 return event->attr.comm || event->attr.mmap ||
6309 event->attr.mmap2 || event->attr.mmap_data ||
6313 static void perf_event_task_output(struct perf_event *event,
6316 struct perf_task_event *task_event = data;
6317 struct perf_output_handle handle;
6318 struct perf_sample_data sample;
6319 struct task_struct *task = task_event->task;
6320 int ret, size = task_event->event_id.header.size;
6322 if (!perf_event_task_match(event))
6325 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
6327 ret = perf_output_begin(&handle, event,
6328 task_event->event_id.header.size);
6332 task_event->event_id.pid = perf_event_pid(event, task);
6333 task_event->event_id.ppid = perf_event_pid(event, current);
6335 task_event->event_id.tid = perf_event_tid(event, task);
6336 task_event->event_id.ptid = perf_event_tid(event, current);
6338 task_event->event_id.time = perf_event_clock(event);
6340 perf_output_put(&handle, task_event->event_id);
6342 perf_event__output_id_sample(event, &handle, &sample);
6344 perf_output_end(&handle);
6346 task_event->event_id.header.size = size;
6349 static void perf_event_task(struct task_struct *task,
6350 struct perf_event_context *task_ctx,
6353 struct perf_task_event task_event;
6355 if (!atomic_read(&nr_comm_events) &&
6356 !atomic_read(&nr_mmap_events) &&
6357 !atomic_read(&nr_task_events))
6360 task_event = (struct perf_task_event){
6362 .task_ctx = task_ctx,
6365 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
6367 .size = sizeof(task_event.event_id),
6377 perf_iterate_sb(perf_event_task_output,
6382 void perf_event_fork(struct task_struct *task)
6384 perf_event_task(task, NULL, 1);
6391 struct perf_comm_event {
6392 struct task_struct *task;
6397 struct perf_event_header header;
6404 static int perf_event_comm_match(struct perf_event *event)
6406 return event->attr.comm;
6409 static void perf_event_comm_output(struct perf_event *event,
6412 struct perf_comm_event *comm_event = data;
6413 struct perf_output_handle handle;
6414 struct perf_sample_data sample;
6415 int size = comm_event->event_id.header.size;
6418 if (!perf_event_comm_match(event))
6421 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
6422 ret = perf_output_begin(&handle, event,
6423 comm_event->event_id.header.size);
6428 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
6429 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
6431 perf_output_put(&handle, comm_event->event_id);
6432 __output_copy(&handle, comm_event->comm,
6433 comm_event->comm_size);
6435 perf_event__output_id_sample(event, &handle, &sample);
6437 perf_output_end(&handle);
6439 comm_event->event_id.header.size = size;
6442 static void perf_event_comm_event(struct perf_comm_event *comm_event)
6444 char comm[TASK_COMM_LEN];
6447 memset(comm, 0, sizeof(comm));
6448 strlcpy(comm, comm_event->task->comm, sizeof(comm));
6449 size = ALIGN(strlen(comm)+1, sizeof(u64));
6451 comm_event->comm = comm;
6452 comm_event->comm_size = size;
6454 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
6456 perf_iterate_sb(perf_event_comm_output,
6461 void perf_event_comm(struct task_struct *task, bool exec)
6463 struct perf_comm_event comm_event;
6465 if (!atomic_read(&nr_comm_events))
6468 comm_event = (struct perf_comm_event){
6474 .type = PERF_RECORD_COMM,
6475 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
6483 perf_event_comm_event(&comm_event);
6490 struct perf_mmap_event {
6491 struct vm_area_struct *vma;
6493 const char *file_name;
6501 struct perf_event_header header;
6511 static int perf_event_mmap_match(struct perf_event *event,
6514 struct perf_mmap_event *mmap_event = data;
6515 struct vm_area_struct *vma = mmap_event->vma;
6516 int executable = vma->vm_flags & VM_EXEC;
6518 return (!executable && event->attr.mmap_data) ||
6519 (executable && (event->attr.mmap || event->attr.mmap2));
6522 static void perf_event_mmap_output(struct perf_event *event,
6525 struct perf_mmap_event *mmap_event = data;
6526 struct perf_output_handle handle;
6527 struct perf_sample_data sample;
6528 int size = mmap_event->event_id.header.size;
6531 if (!perf_event_mmap_match(event, data))
6534 if (event->attr.mmap2) {
6535 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
6536 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
6537 mmap_event->event_id.header.size += sizeof(mmap_event->min);
6538 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
6539 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
6540 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
6541 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
6544 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
6545 ret = perf_output_begin(&handle, event,
6546 mmap_event->event_id.header.size);
6550 mmap_event->event_id.pid = perf_event_pid(event, current);
6551 mmap_event->event_id.tid = perf_event_tid(event, current);
6553 perf_output_put(&handle, mmap_event->event_id);
6555 if (event->attr.mmap2) {
6556 perf_output_put(&handle, mmap_event->maj);
6557 perf_output_put(&handle, mmap_event->min);
6558 perf_output_put(&handle, mmap_event->ino);
6559 perf_output_put(&handle, mmap_event->ino_generation);
6560 perf_output_put(&handle, mmap_event->prot);
6561 perf_output_put(&handle, mmap_event->flags);
6564 __output_copy(&handle, mmap_event->file_name,
6565 mmap_event->file_size);
6567 perf_event__output_id_sample(event, &handle, &sample);
6569 perf_output_end(&handle);
6571 mmap_event->event_id.header.size = size;
6574 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
6576 struct vm_area_struct *vma = mmap_event->vma;
6577 struct file *file = vma->vm_file;
6578 int maj = 0, min = 0;
6579 u64 ino = 0, gen = 0;
6580 u32 prot = 0, flags = 0;
6587 struct inode *inode;
6590 buf = kmalloc(PATH_MAX, GFP_KERNEL);
6596 * d_path() works from the end of the rb backwards, so we
6597 * need to add enough zero bytes after the string to handle
6598 * the 64bit alignment we do later.
6600 name = file_path(file, buf, PATH_MAX - sizeof(u64));
6605 inode = file_inode(vma->vm_file);
6606 dev = inode->i_sb->s_dev;
6608 gen = inode->i_generation;
6612 if (vma->vm_flags & VM_READ)
6614 if (vma->vm_flags & VM_WRITE)
6616 if (vma->vm_flags & VM_EXEC)
6619 if (vma->vm_flags & VM_MAYSHARE)
6622 flags = MAP_PRIVATE;
6624 if (vma->vm_flags & VM_DENYWRITE)
6625 flags |= MAP_DENYWRITE;
6626 if (vma->vm_flags & VM_MAYEXEC)
6627 flags |= MAP_EXECUTABLE;
6628 if (vma->vm_flags & VM_LOCKED)
6629 flags |= MAP_LOCKED;
6630 if (vma->vm_flags & VM_HUGETLB)
6631 flags |= MAP_HUGETLB;
6635 if (vma->vm_ops && vma->vm_ops->name) {
6636 name = (char *) vma->vm_ops->name(vma);
6641 name = (char *)arch_vma_name(vma);
6645 if (vma->vm_start <= vma->vm_mm->start_brk &&
6646 vma->vm_end >= vma->vm_mm->brk) {
6650 if (vma->vm_start <= vma->vm_mm->start_stack &&
6651 vma->vm_end >= vma->vm_mm->start_stack) {
6661 strlcpy(tmp, name, sizeof(tmp));
6665 * Since our buffer works in 8 byte units we need to align our string
6666 * size to a multiple of 8. However, we must guarantee the tail end is
6667 * zero'd out to avoid leaking random bits to userspace.
6669 size = strlen(name)+1;
6670 while (!IS_ALIGNED(size, sizeof(u64)))
6671 name[size++] = '\0';
6673 mmap_event->file_name = name;
6674 mmap_event->file_size = size;
6675 mmap_event->maj = maj;
6676 mmap_event->min = min;
6677 mmap_event->ino = ino;
6678 mmap_event->ino_generation = gen;
6679 mmap_event->prot = prot;
6680 mmap_event->flags = flags;
6682 if (!(vma->vm_flags & VM_EXEC))
6683 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
6685 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
6687 perf_iterate_sb(perf_event_mmap_output,
6695 * Check whether inode and address range match filter criteria.
6697 static bool perf_addr_filter_match(struct perf_addr_filter *filter,
6698 struct file *file, unsigned long offset,
6701 if (filter->inode != file->f_inode)
6704 if (filter->offset > offset + size)
6707 if (filter->offset + filter->size < offset)
6713 static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
6715 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6716 struct vm_area_struct *vma = data;
6717 unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags;
6718 struct file *file = vma->vm_file;
6719 struct perf_addr_filter *filter;
6720 unsigned int restart = 0, count = 0;
6722 if (!has_addr_filter(event))
6728 raw_spin_lock_irqsave(&ifh->lock, flags);
6729 list_for_each_entry(filter, &ifh->list, entry) {
6730 if (perf_addr_filter_match(filter, file, off,
6731 vma->vm_end - vma->vm_start)) {
6732 event->addr_filters_offs[count] = vma->vm_start;
6740 event->addr_filters_gen++;
6741 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6744 perf_event_stop(event, 1);
6748 * Adjust all task's events' filters to the new vma
6750 static void perf_addr_filters_adjust(struct vm_area_struct *vma)
6752 struct perf_event_context *ctx;
6756 * Data tracing isn't supported yet and as such there is no need
6757 * to keep track of anything that isn't related to executable code:
6759 if (!(vma->vm_flags & VM_EXEC))
6763 for_each_task_context_nr(ctxn) {
6764 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6768 perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
6773 void perf_event_mmap(struct vm_area_struct *vma)
6775 struct perf_mmap_event mmap_event;
6777 if (!atomic_read(&nr_mmap_events))
6780 mmap_event = (struct perf_mmap_event){
6786 .type = PERF_RECORD_MMAP,
6787 .misc = PERF_RECORD_MISC_USER,
6792 .start = vma->vm_start,
6793 .len = vma->vm_end - vma->vm_start,
6794 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
6796 /* .maj (attr_mmap2 only) */
6797 /* .min (attr_mmap2 only) */
6798 /* .ino (attr_mmap2 only) */
6799 /* .ino_generation (attr_mmap2 only) */
6800 /* .prot (attr_mmap2 only) */
6801 /* .flags (attr_mmap2 only) */
6804 perf_addr_filters_adjust(vma);
6805 perf_event_mmap_event(&mmap_event);
6808 void perf_event_aux_event(struct perf_event *event, unsigned long head,
6809 unsigned long size, u64 flags)
6811 struct perf_output_handle handle;
6812 struct perf_sample_data sample;
6813 struct perf_aux_event {
6814 struct perf_event_header header;
6820 .type = PERF_RECORD_AUX,
6822 .size = sizeof(rec),
6830 perf_event_header__init_id(&rec.header, &sample, event);
6831 ret = perf_output_begin(&handle, event, rec.header.size);
6836 perf_output_put(&handle, rec);
6837 perf_event__output_id_sample(event, &handle, &sample);
6839 perf_output_end(&handle);
6843 * Lost/dropped samples logging
6845 void perf_log_lost_samples(struct perf_event *event, u64 lost)
6847 struct perf_output_handle handle;
6848 struct perf_sample_data sample;
6852 struct perf_event_header header;
6854 } lost_samples_event = {
6856 .type = PERF_RECORD_LOST_SAMPLES,
6858 .size = sizeof(lost_samples_event),
6863 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
6865 ret = perf_output_begin(&handle, event,
6866 lost_samples_event.header.size);
6870 perf_output_put(&handle, lost_samples_event);
6871 perf_event__output_id_sample(event, &handle, &sample);
6872 perf_output_end(&handle);
6876 * context_switch tracking
6879 struct perf_switch_event {
6880 struct task_struct *task;
6881 struct task_struct *next_prev;
6884 struct perf_event_header header;
6890 static int perf_event_switch_match(struct perf_event *event)
6892 return event->attr.context_switch;
6895 static void perf_event_switch_output(struct perf_event *event, void *data)
6897 struct perf_switch_event *se = data;
6898 struct perf_output_handle handle;
6899 struct perf_sample_data sample;
6902 if (!perf_event_switch_match(event))
6905 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6906 if (event->ctx->task) {
6907 se->event_id.header.type = PERF_RECORD_SWITCH;
6908 se->event_id.header.size = sizeof(se->event_id.header);
6910 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
6911 se->event_id.header.size = sizeof(se->event_id);
6912 se->event_id.next_prev_pid =
6913 perf_event_pid(event, se->next_prev);
6914 se->event_id.next_prev_tid =
6915 perf_event_tid(event, se->next_prev);
6918 perf_event_header__init_id(&se->event_id.header, &sample, event);
6920 ret = perf_output_begin(&handle, event, se->event_id.header.size);
6924 if (event->ctx->task)
6925 perf_output_put(&handle, se->event_id.header);
6927 perf_output_put(&handle, se->event_id);
6929 perf_event__output_id_sample(event, &handle, &sample);
6931 perf_output_end(&handle);
6934 static void perf_event_switch(struct task_struct *task,
6935 struct task_struct *next_prev, bool sched_in)
6937 struct perf_switch_event switch_event;
6939 /* N.B. caller checks nr_switch_events != 0 */
6941 switch_event = (struct perf_switch_event){
6943 .next_prev = next_prev,
6947 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
6950 /* .next_prev_pid */
6951 /* .next_prev_tid */
6955 perf_iterate_sb(perf_event_switch_output,
6961 * IRQ throttle logging
6964 static void perf_log_throttle(struct perf_event *event, int enable)
6966 struct perf_output_handle handle;
6967 struct perf_sample_data sample;
6971 struct perf_event_header header;
6975 } throttle_event = {
6977 .type = PERF_RECORD_THROTTLE,
6979 .size = sizeof(throttle_event),
6981 .time = perf_event_clock(event),
6982 .id = primary_event_id(event),
6983 .stream_id = event->id,
6987 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
6989 perf_event_header__init_id(&throttle_event.header, &sample, event);
6991 ret = perf_output_begin(&handle, event,
6992 throttle_event.header.size);
6996 perf_output_put(&handle, throttle_event);
6997 perf_event__output_id_sample(event, &handle, &sample);
6998 perf_output_end(&handle);
7001 static void perf_log_itrace_start(struct perf_event *event)
7003 struct perf_output_handle handle;
7004 struct perf_sample_data sample;
7005 struct perf_aux_event {
7006 struct perf_event_header header;
7013 event = event->parent;
7015 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
7016 event->hw.itrace_started)
7019 rec.header.type = PERF_RECORD_ITRACE_START;
7020 rec.header.misc = 0;
7021 rec.header.size = sizeof(rec);
7022 rec.pid = perf_event_pid(event, current);
7023 rec.tid = perf_event_tid(event, current);
7025 perf_event_header__init_id(&rec.header, &sample, event);
7026 ret = perf_output_begin(&handle, event, rec.header.size);
7031 perf_output_put(&handle, rec);
7032 perf_event__output_id_sample(event, &handle, &sample);
7034 perf_output_end(&handle);
7038 * Generic event overflow handling, sampling.
7041 static int __perf_event_overflow(struct perf_event *event,
7042 int throttle, struct perf_sample_data *data,
7043 struct pt_regs *regs)
7045 int events = atomic_read(&event->event_limit);
7046 struct hw_perf_event *hwc = &event->hw;
7051 * Non-sampling counters might still use the PMI to fold short
7052 * hardware counters, ignore those.
7054 if (unlikely(!is_sampling_event(event)))
7057 seq = __this_cpu_read(perf_throttled_seq);
7058 if (seq != hwc->interrupts_seq) {
7059 hwc->interrupts_seq = seq;
7060 hwc->interrupts = 1;
7063 if (unlikely(throttle
7064 && hwc->interrupts >= max_samples_per_tick)) {
7065 __this_cpu_inc(perf_throttled_count);
7066 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
7067 hwc->interrupts = MAX_INTERRUPTS;
7068 perf_log_throttle(event, 0);
7073 if (event->attr.freq) {
7074 u64 now = perf_clock();
7075 s64 delta = now - hwc->freq_time_stamp;
7077 hwc->freq_time_stamp = now;
7079 if (delta > 0 && delta < 2*TICK_NSEC)
7080 perf_adjust_period(event, delta, hwc->last_period, true);
7084 * XXX event_limit might not quite work as expected on inherited
7088 event->pending_kill = POLL_IN;
7089 if (events && atomic_dec_and_test(&event->event_limit)) {
7091 event->pending_kill = POLL_HUP;
7093 perf_event_disable_inatomic(event);
7096 READ_ONCE(event->overflow_handler)(event, data, regs);
7098 if (*perf_event_fasync(event) && event->pending_kill) {
7099 event->pending_wakeup = 1;
7100 irq_work_queue(&event->pending);
7106 int perf_event_overflow(struct perf_event *event,
7107 struct perf_sample_data *data,
7108 struct pt_regs *regs)
7110 return __perf_event_overflow(event, 1, data, regs);
7114 * Generic software event infrastructure
7117 struct swevent_htable {
7118 struct swevent_hlist *swevent_hlist;
7119 struct mutex hlist_mutex;
7122 /* Recursion avoidance in each contexts */
7123 int recursion[PERF_NR_CONTEXTS];
7126 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
7129 * We directly increment event->count and keep a second value in
7130 * event->hw.period_left to count intervals. This period event
7131 * is kept in the range [-sample_period, 0] so that we can use the
7135 u64 perf_swevent_set_period(struct perf_event *event)
7137 struct hw_perf_event *hwc = &event->hw;
7138 u64 period = hwc->last_period;
7142 hwc->last_period = hwc->sample_period;
7145 old = val = local64_read(&hwc->period_left);
7149 nr = div64_u64(period + val, period);
7150 offset = nr * period;
7152 if (local64_cmpxchg(&hwc->period_left, old, val) != old)
7158 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
7159 struct perf_sample_data *data,
7160 struct pt_regs *regs)
7162 struct hw_perf_event *hwc = &event->hw;
7166 overflow = perf_swevent_set_period(event);
7168 if (hwc->interrupts == MAX_INTERRUPTS)
7171 for (; overflow; overflow--) {
7172 if (__perf_event_overflow(event, throttle,
7175 * We inhibit the overflow from happening when
7176 * hwc->interrupts == MAX_INTERRUPTS.
7184 static void perf_swevent_event(struct perf_event *event, u64 nr,
7185 struct perf_sample_data *data,
7186 struct pt_regs *regs)
7188 struct hw_perf_event *hwc = &event->hw;
7190 local64_add(nr, &event->count);
7195 if (!is_sampling_event(event))
7198 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
7200 return perf_swevent_overflow(event, 1, data, regs);
7202 data->period = event->hw.last_period;
7204 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
7205 return perf_swevent_overflow(event, 1, data, regs);
7207 if (local64_add_negative(nr, &hwc->period_left))
7210 perf_swevent_overflow(event, 0, data, regs);
7213 static int perf_exclude_event(struct perf_event *event,
7214 struct pt_regs *regs)
7216 if (event->hw.state & PERF_HES_STOPPED)
7220 if (event->attr.exclude_user && user_mode(regs))
7223 if (event->attr.exclude_kernel && !user_mode(regs))
7230 static int perf_swevent_match(struct perf_event *event,
7231 enum perf_type_id type,
7233 struct perf_sample_data *data,
7234 struct pt_regs *regs)
7236 if (event->attr.type != type)
7239 if (event->attr.config != event_id)
7242 if (perf_exclude_event(event, regs))
7248 static inline u64 swevent_hash(u64 type, u32 event_id)
7250 u64 val = event_id | (type << 32);
7252 return hash_64(val, SWEVENT_HLIST_BITS);
7255 static inline struct hlist_head *
7256 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
7258 u64 hash = swevent_hash(type, event_id);
7260 return &hlist->heads[hash];
7263 /* For the read side: events when they trigger */
7264 static inline struct hlist_head *
7265 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
7267 struct swevent_hlist *hlist;
7269 hlist = rcu_dereference(swhash->swevent_hlist);
7273 return __find_swevent_head(hlist, type, event_id);
7276 /* For the event head insertion and removal in the hlist */
7277 static inline struct hlist_head *
7278 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
7280 struct swevent_hlist *hlist;
7281 u32 event_id = event->attr.config;
7282 u64 type = event->attr.type;
7285 * Event scheduling is always serialized against hlist allocation
7286 * and release. Which makes the protected version suitable here.
7287 * The context lock guarantees that.
7289 hlist = rcu_dereference_protected(swhash->swevent_hlist,
7290 lockdep_is_held(&event->ctx->lock));
7294 return __find_swevent_head(hlist, type, event_id);
7297 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
7299 struct perf_sample_data *data,
7300 struct pt_regs *regs)
7302 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7303 struct perf_event *event;
7304 struct hlist_head *head;
7307 head = find_swevent_head_rcu(swhash, type, event_id);
7311 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7312 if (perf_swevent_match(event, type, event_id, data, regs))
7313 perf_swevent_event(event, nr, data, regs);
7319 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
7321 int perf_swevent_get_recursion_context(void)
7323 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7325 return get_recursion_context(swhash->recursion);
7327 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
7329 void perf_swevent_put_recursion_context(int rctx)
7331 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7333 put_recursion_context(swhash->recursion, rctx);
7336 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7338 struct perf_sample_data data;
7340 if (WARN_ON_ONCE(!regs))
7343 perf_sample_data_init(&data, addr, 0);
7344 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
7347 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7351 preempt_disable_notrace();
7352 rctx = perf_swevent_get_recursion_context();
7353 if (unlikely(rctx < 0))
7356 ___perf_sw_event(event_id, nr, regs, addr);
7358 perf_swevent_put_recursion_context(rctx);
7360 preempt_enable_notrace();
7363 static void perf_swevent_read(struct perf_event *event)
7367 static int perf_swevent_add(struct perf_event *event, int flags)
7369 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7370 struct hw_perf_event *hwc = &event->hw;
7371 struct hlist_head *head;
7373 if (is_sampling_event(event)) {
7374 hwc->last_period = hwc->sample_period;
7375 perf_swevent_set_period(event);
7378 hwc->state = !(flags & PERF_EF_START);
7380 head = find_swevent_head(swhash, event);
7381 if (WARN_ON_ONCE(!head))
7384 hlist_add_head_rcu(&event->hlist_entry, head);
7385 perf_event_update_userpage(event);
7390 static void perf_swevent_del(struct perf_event *event, int flags)
7392 hlist_del_rcu(&event->hlist_entry);
7395 static void perf_swevent_start(struct perf_event *event, int flags)
7397 event->hw.state = 0;
7400 static void perf_swevent_stop(struct perf_event *event, int flags)
7402 event->hw.state = PERF_HES_STOPPED;
7405 /* Deref the hlist from the update side */
7406 static inline struct swevent_hlist *
7407 swevent_hlist_deref(struct swevent_htable *swhash)
7409 return rcu_dereference_protected(swhash->swevent_hlist,
7410 lockdep_is_held(&swhash->hlist_mutex));
7413 static void swevent_hlist_release(struct swevent_htable *swhash)
7415 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
7420 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
7421 kfree_rcu(hlist, rcu_head);
7424 static void swevent_hlist_put_cpu(int cpu)
7426 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7428 mutex_lock(&swhash->hlist_mutex);
7430 if (!--swhash->hlist_refcount)
7431 swevent_hlist_release(swhash);
7433 mutex_unlock(&swhash->hlist_mutex);
7436 static void swevent_hlist_put(void)
7440 for_each_possible_cpu(cpu)
7441 swevent_hlist_put_cpu(cpu);
7444 static int swevent_hlist_get_cpu(int cpu)
7446 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7449 mutex_lock(&swhash->hlist_mutex);
7450 if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
7451 struct swevent_hlist *hlist;
7453 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
7458 rcu_assign_pointer(swhash->swevent_hlist, hlist);
7460 swhash->hlist_refcount++;
7462 mutex_unlock(&swhash->hlist_mutex);
7467 static int swevent_hlist_get(void)
7469 int err, cpu, failed_cpu;
7472 for_each_possible_cpu(cpu) {
7473 err = swevent_hlist_get_cpu(cpu);
7483 for_each_possible_cpu(cpu) {
7484 if (cpu == failed_cpu)
7486 swevent_hlist_put_cpu(cpu);
7493 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
7495 static void sw_perf_event_destroy(struct perf_event *event)
7497 u64 event_id = event->attr.config;
7499 WARN_ON(event->parent);
7501 static_key_slow_dec(&perf_swevent_enabled[event_id]);
7502 swevent_hlist_put();
7505 static int perf_swevent_init(struct perf_event *event)
7507 u64 event_id = event->attr.config;
7509 if (event->attr.type != PERF_TYPE_SOFTWARE)
7513 * no branch sampling for software events
7515 if (has_branch_stack(event))
7519 case PERF_COUNT_SW_CPU_CLOCK:
7520 case PERF_COUNT_SW_TASK_CLOCK:
7527 if (event_id >= PERF_COUNT_SW_MAX)
7530 if (!event->parent) {
7533 err = swevent_hlist_get();
7537 static_key_slow_inc(&perf_swevent_enabled[event_id]);
7538 event->destroy = sw_perf_event_destroy;
7544 static struct pmu perf_swevent = {
7545 .task_ctx_nr = perf_sw_context,
7547 .capabilities = PERF_PMU_CAP_NO_NMI,
7549 .event_init = perf_swevent_init,
7550 .add = perf_swevent_add,
7551 .del = perf_swevent_del,
7552 .start = perf_swevent_start,
7553 .stop = perf_swevent_stop,
7554 .read = perf_swevent_read,
7557 #ifdef CONFIG_EVENT_TRACING
7559 static int perf_tp_filter_match(struct perf_event *event,
7560 struct perf_sample_data *data)
7562 void *record = data->raw->frag.data;
7564 /* only top level events have filters set */
7566 event = event->parent;
7568 if (likely(!event->filter) || filter_match_preds(event->filter, record))
7573 static int perf_tp_event_match(struct perf_event *event,
7574 struct perf_sample_data *data,
7575 struct pt_regs *regs)
7577 if (event->hw.state & PERF_HES_STOPPED)
7580 * All tracepoints are from kernel-space.
7582 if (event->attr.exclude_kernel)
7585 if (!perf_tp_filter_match(event, data))
7591 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
7592 struct trace_event_call *call, u64 count,
7593 struct pt_regs *regs, struct hlist_head *head,
7594 struct task_struct *task)
7596 struct bpf_prog *prog = call->prog;
7599 *(struct pt_regs **)raw_data = regs;
7600 if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) {
7601 perf_swevent_put_recursion_context(rctx);
7605 perf_tp_event(call->event.type, count, raw_data, size, regs, head,
7608 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
7610 void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
7611 struct pt_regs *regs, struct hlist_head *head, int rctx,
7612 struct task_struct *task)
7614 struct perf_sample_data data;
7615 struct perf_event *event;
7617 struct perf_raw_record raw = {
7624 perf_sample_data_init(&data, 0, 0);
7627 perf_trace_buf_update(record, event_type);
7629 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7630 if (perf_tp_event_match(event, &data, regs))
7631 perf_swevent_event(event, count, &data, regs);
7635 * If we got specified a target task, also iterate its context and
7636 * deliver this event there too.
7638 if (task && task != current) {
7639 struct perf_event_context *ctx;
7640 struct trace_entry *entry = record;
7643 ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
7647 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
7648 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7650 if (event->attr.config != entry->type)
7652 if (perf_tp_event_match(event, &data, regs))
7653 perf_swevent_event(event, count, &data, regs);
7659 perf_swevent_put_recursion_context(rctx);
7661 EXPORT_SYMBOL_GPL(perf_tp_event);
7663 static void tp_perf_event_destroy(struct perf_event *event)
7665 perf_trace_destroy(event);
7668 static int perf_tp_event_init(struct perf_event *event)
7672 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7676 * no branch sampling for tracepoint events
7678 if (has_branch_stack(event))
7681 err = perf_trace_init(event);
7685 event->destroy = tp_perf_event_destroy;
7690 static struct pmu perf_tracepoint = {
7691 .task_ctx_nr = perf_sw_context,
7693 .event_init = perf_tp_event_init,
7694 .add = perf_trace_add,
7695 .del = perf_trace_del,
7696 .start = perf_swevent_start,
7697 .stop = perf_swevent_stop,
7698 .read = perf_swevent_read,
7701 static inline void perf_tp_register(void)
7703 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
7706 static void perf_event_free_filter(struct perf_event *event)
7708 ftrace_profile_free_filter(event);
7711 #ifdef CONFIG_BPF_SYSCALL
7712 static void bpf_overflow_handler(struct perf_event *event,
7713 struct perf_sample_data *data,
7714 struct pt_regs *regs)
7716 struct bpf_perf_event_data_kern ctx = {
7723 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
7726 ret = BPF_PROG_RUN(event->prog, (void *)&ctx);
7729 __this_cpu_dec(bpf_prog_active);
7734 event->orig_overflow_handler(event, data, regs);
7737 static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
7739 struct bpf_prog *prog;
7741 if (event->overflow_handler_context)
7742 /* hw breakpoint or kernel counter */
7748 prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT);
7750 return PTR_ERR(prog);
7753 event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
7754 WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
7758 static void perf_event_free_bpf_handler(struct perf_event *event)
7760 struct bpf_prog *prog = event->prog;
7765 WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler);
7770 static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
7774 static void perf_event_free_bpf_handler(struct perf_event *event)
7779 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7781 bool is_kprobe, is_tracepoint;
7782 struct bpf_prog *prog;
7784 if (event->attr.type == PERF_TYPE_HARDWARE ||
7785 event->attr.type == PERF_TYPE_SOFTWARE)
7786 return perf_event_set_bpf_handler(event, prog_fd);
7788 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7791 if (event->tp_event->prog)
7794 is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE;
7795 is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
7796 if (!is_kprobe && !is_tracepoint)
7797 /* bpf programs can only be attached to u/kprobe or tracepoint */
7800 prog = bpf_prog_get(prog_fd);
7802 return PTR_ERR(prog);
7804 if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) ||
7805 (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT)) {
7806 /* valid fd, but invalid bpf program type */
7811 if (is_tracepoint) {
7812 int off = trace_event_get_offsets(event->tp_event);
7814 if (prog->aux->max_ctx_offset > off) {
7819 event->tp_event->prog = prog;
7824 static void perf_event_free_bpf_prog(struct perf_event *event)
7826 struct bpf_prog *prog;
7828 perf_event_free_bpf_handler(event);
7830 if (!event->tp_event)
7833 prog = event->tp_event->prog;
7835 event->tp_event->prog = NULL;
7842 static inline void perf_tp_register(void)
7846 static void perf_event_free_filter(struct perf_event *event)
7850 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7855 static void perf_event_free_bpf_prog(struct perf_event *event)
7858 #endif /* CONFIG_EVENT_TRACING */
7860 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7861 void perf_bp_event(struct perf_event *bp, void *data)
7863 struct perf_sample_data sample;
7864 struct pt_regs *regs = data;
7866 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
7868 if (!bp->hw.state && !perf_exclude_event(bp, regs))
7869 perf_swevent_event(bp, 1, &sample, regs);
7874 * Allocate a new address filter
7876 static struct perf_addr_filter *
7877 perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
7879 int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
7880 struct perf_addr_filter *filter;
7882 filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
7886 INIT_LIST_HEAD(&filter->entry);
7887 list_add_tail(&filter->entry, filters);
7892 static void free_filters_list(struct list_head *filters)
7894 struct perf_addr_filter *filter, *iter;
7896 list_for_each_entry_safe(filter, iter, filters, entry) {
7898 iput(filter->inode);
7899 list_del(&filter->entry);
7905 * Free existing address filters and optionally install new ones
7907 static void perf_addr_filters_splice(struct perf_event *event,
7908 struct list_head *head)
7910 unsigned long flags;
7913 if (!has_addr_filter(event))
7916 /* don't bother with children, they don't have their own filters */
7920 raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
7922 list_splice_init(&event->addr_filters.list, &list);
7924 list_splice(head, &event->addr_filters.list);
7926 raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
7928 free_filters_list(&list);
7932 * Scan through mm's vmas and see if one of them matches the
7933 * @filter; if so, adjust filter's address range.
7934 * Called with mm::mmap_sem down for reading.
7936 static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter,
7937 struct mm_struct *mm)
7939 struct vm_area_struct *vma;
7941 for (vma = mm->mmap; vma; vma = vma->vm_next) {
7942 struct file *file = vma->vm_file;
7943 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
7944 unsigned long vma_size = vma->vm_end - vma->vm_start;
7949 if (!perf_addr_filter_match(filter, file, off, vma_size))
7952 return vma->vm_start;
7959 * Update event's address range filters based on the
7960 * task's existing mappings, if any.
7962 static void perf_event_addr_filters_apply(struct perf_event *event)
7964 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
7965 struct task_struct *task = READ_ONCE(event->ctx->task);
7966 struct perf_addr_filter *filter;
7967 struct mm_struct *mm = NULL;
7968 unsigned int count = 0;
7969 unsigned long flags;
7972 * We may observe TASK_TOMBSTONE, which means that the event tear-down
7973 * will stop on the parent's child_mutex that our caller is also holding
7975 if (task == TASK_TOMBSTONE)
7978 mm = get_task_mm(event->ctx->task);
7982 down_read(&mm->mmap_sem);
7984 raw_spin_lock_irqsave(&ifh->lock, flags);
7985 list_for_each_entry(filter, &ifh->list, entry) {
7986 event->addr_filters_offs[count] = 0;
7989 * Adjust base offset if the filter is associated to a binary
7990 * that needs to be mapped:
7993 event->addr_filters_offs[count] =
7994 perf_addr_filter_apply(filter, mm);
7999 event->addr_filters_gen++;
8000 raw_spin_unlock_irqrestore(&ifh->lock, flags);
8002 up_read(&mm->mmap_sem);
8007 perf_event_stop(event, 1);
8011 * Address range filtering: limiting the data to certain
8012 * instruction address ranges. Filters are ioctl()ed to us from
8013 * userspace as ascii strings.
8015 * Filter string format:
8018 * where ACTION is one of the
8019 * * "filter": limit the trace to this region
8020 * * "start": start tracing from this address
8021 * * "stop": stop tracing at this address/region;
8023 * * for kernel addresses: <start address>[/<size>]
8024 * * for object files: <start address>[/<size>]@</path/to/object/file>
8026 * if <size> is not specified, the range is treated as a single address.
8040 IF_STATE_ACTION = 0,
8045 static const match_table_t if_tokens = {
8046 { IF_ACT_FILTER, "filter" },
8047 { IF_ACT_START, "start" },
8048 { IF_ACT_STOP, "stop" },
8049 { IF_SRC_FILE, "%u/%u@%s" },
8050 { IF_SRC_KERNEL, "%u/%u" },
8051 { IF_SRC_FILEADDR, "%u@%s" },
8052 { IF_SRC_KERNELADDR, "%u" },
8053 { IF_ACT_NONE, NULL },
8057 * Address filter string parser
8060 perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
8061 struct list_head *filters)
8063 struct perf_addr_filter *filter = NULL;
8064 char *start, *orig, *filename = NULL;
8066 substring_t args[MAX_OPT_ARGS];
8067 int state = IF_STATE_ACTION, token;
8068 unsigned int kernel = 0;
8071 orig = fstr = kstrdup(fstr, GFP_KERNEL);
8075 while ((start = strsep(&fstr, " ,\n")) != NULL) {
8081 /* filter definition begins */
8082 if (state == IF_STATE_ACTION) {
8083 filter = perf_addr_filter_new(event, filters);
8088 token = match_token(start, if_tokens, args);
8095 if (state != IF_STATE_ACTION)
8098 state = IF_STATE_SOURCE;
8101 case IF_SRC_KERNELADDR:
8105 case IF_SRC_FILEADDR:
8107 if (state != IF_STATE_SOURCE)
8110 if (token == IF_SRC_FILE || token == IF_SRC_KERNEL)
8114 ret = kstrtoul(args[0].from, 0, &filter->offset);
8118 if (filter->range) {
8120 ret = kstrtoul(args[1].from, 0, &filter->size);
8125 if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
8126 int fpos = filter->range ? 2 : 1;
8128 filename = match_strdup(&args[fpos]);
8135 state = IF_STATE_END;
8143 * Filter definition is fully parsed, validate and install it.
8144 * Make sure that it doesn't contradict itself or the event's
8147 if (state == IF_STATE_END) {
8148 if (kernel && event->attr.exclude_kernel)
8155 /* look up the path and grab its inode */
8156 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
8158 goto fail_free_name;
8160 filter->inode = igrab(d_inode(path.dentry));
8166 if (!filter->inode ||
8167 !S_ISREG(filter->inode->i_mode))
8168 /* free_filters_list() will iput() */
8172 /* ready to consume more filters */
8173 state = IF_STATE_ACTION;
8178 if (state != IF_STATE_ACTION)
8188 free_filters_list(filters);
8195 perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
8201 * Since this is called in perf_ioctl() path, we're already holding
8204 lockdep_assert_held(&event->ctx->mutex);
8206 if (WARN_ON_ONCE(event->parent))
8210 * For now, we only support filtering in per-task events; doing so
8211 * for CPU-wide events requires additional context switching trickery,
8212 * since same object code will be mapped at different virtual
8213 * addresses in different processes.
8215 if (!event->ctx->task)
8218 ret = perf_event_parse_addr_filter(event, filter_str, &filters);
8222 ret = event->pmu->addr_filters_validate(&filters);
8224 free_filters_list(&filters);
8228 /* remove existing filters, if any */
8229 perf_addr_filters_splice(event, &filters);
8231 /* install new filters */
8232 perf_event_for_each_child(event, perf_event_addr_filters_apply);
8237 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
8242 if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
8243 !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
8244 !has_addr_filter(event))
8247 filter_str = strndup_user(arg, PAGE_SIZE);
8248 if (IS_ERR(filter_str))
8249 return PTR_ERR(filter_str);
8251 if (IS_ENABLED(CONFIG_EVENT_TRACING) &&
8252 event->attr.type == PERF_TYPE_TRACEPOINT)
8253 ret = ftrace_profile_set_filter(event, event->attr.config,
8255 else if (has_addr_filter(event))
8256 ret = perf_event_set_addr_filter(event, filter_str);
8263 * hrtimer based swevent callback
8266 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
8268 enum hrtimer_restart ret = HRTIMER_RESTART;
8269 struct perf_sample_data data;
8270 struct pt_regs *regs;
8271 struct perf_event *event;
8274 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
8276 if (event->state != PERF_EVENT_STATE_ACTIVE)
8277 return HRTIMER_NORESTART;
8279 event->pmu->read(event);
8281 perf_sample_data_init(&data, 0, event->hw.last_period);
8282 regs = get_irq_regs();
8284 if (regs && !perf_exclude_event(event, regs)) {
8285 if (!(event->attr.exclude_idle && is_idle_task(current)))
8286 if (__perf_event_overflow(event, 1, &data, regs))
8287 ret = HRTIMER_NORESTART;
8290 period = max_t(u64, 10000, event->hw.sample_period);
8291 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
8296 static void perf_swevent_start_hrtimer(struct perf_event *event)
8298 struct hw_perf_event *hwc = &event->hw;
8301 if (!is_sampling_event(event))
8304 period = local64_read(&hwc->period_left);
8309 local64_set(&hwc->period_left, 0);
8311 period = max_t(u64, 10000, hwc->sample_period);
8313 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
8314 HRTIMER_MODE_REL_PINNED);
8317 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
8319 struct hw_perf_event *hwc = &event->hw;
8321 if (is_sampling_event(event)) {
8322 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
8323 local64_set(&hwc->period_left, ktime_to_ns(remaining));
8325 hrtimer_cancel(&hwc->hrtimer);
8329 static void perf_swevent_init_hrtimer(struct perf_event *event)
8331 struct hw_perf_event *hwc = &event->hw;
8333 if (!is_sampling_event(event))
8336 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
8337 hwc->hrtimer.function = perf_swevent_hrtimer;
8340 * Since hrtimers have a fixed rate, we can do a static freq->period
8341 * mapping and avoid the whole period adjust feedback stuff.
8343 if (event->attr.freq) {
8344 long freq = event->attr.sample_freq;
8346 event->attr.sample_period = NSEC_PER_SEC / freq;
8347 hwc->sample_period = event->attr.sample_period;
8348 local64_set(&hwc->period_left, hwc->sample_period);
8349 hwc->last_period = hwc->sample_period;
8350 event->attr.freq = 0;
8355 * Software event: cpu wall time clock
8358 static void cpu_clock_event_update(struct perf_event *event)
8363 now = local_clock();
8364 prev = local64_xchg(&event->hw.prev_count, now);
8365 local64_add(now - prev, &event->count);
8368 static void cpu_clock_event_start(struct perf_event *event, int flags)
8370 local64_set(&event->hw.prev_count, local_clock());
8371 perf_swevent_start_hrtimer(event);
8374 static void cpu_clock_event_stop(struct perf_event *event, int flags)
8376 perf_swevent_cancel_hrtimer(event);
8377 cpu_clock_event_update(event);
8380 static int cpu_clock_event_add(struct perf_event *event, int flags)
8382 if (flags & PERF_EF_START)
8383 cpu_clock_event_start(event, flags);
8384 perf_event_update_userpage(event);
8389 static void cpu_clock_event_del(struct perf_event *event, int flags)
8391 cpu_clock_event_stop(event, flags);
8394 static void cpu_clock_event_read(struct perf_event *event)
8396 cpu_clock_event_update(event);
8399 static int cpu_clock_event_init(struct perf_event *event)
8401 if (event->attr.type != PERF_TYPE_SOFTWARE)
8404 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
8408 * no branch sampling for software events
8410 if (has_branch_stack(event))
8413 perf_swevent_init_hrtimer(event);
8418 static struct pmu perf_cpu_clock = {
8419 .task_ctx_nr = perf_sw_context,
8421 .capabilities = PERF_PMU_CAP_NO_NMI,
8423 .event_init = cpu_clock_event_init,
8424 .add = cpu_clock_event_add,
8425 .del = cpu_clock_event_del,
8426 .start = cpu_clock_event_start,
8427 .stop = cpu_clock_event_stop,
8428 .read = cpu_clock_event_read,
8432 * Software event: task time clock
8435 static void task_clock_event_update(struct perf_event *event, u64 now)
8440 prev = local64_xchg(&event->hw.prev_count, now);
8442 local64_add(delta, &event->count);
8445 static void task_clock_event_start(struct perf_event *event, int flags)
8447 local64_set(&event->hw.prev_count, event->ctx->time);
8448 perf_swevent_start_hrtimer(event);
8451 static void task_clock_event_stop(struct perf_event *event, int flags)
8453 perf_swevent_cancel_hrtimer(event);
8454 task_clock_event_update(event, event->ctx->time);
8457 static int task_clock_event_add(struct perf_event *event, int flags)
8459 if (flags & PERF_EF_START)
8460 task_clock_event_start(event, flags);
8461 perf_event_update_userpage(event);
8466 static void task_clock_event_del(struct perf_event *event, int flags)
8468 task_clock_event_stop(event, PERF_EF_UPDATE);
8471 static void task_clock_event_read(struct perf_event *event)
8473 u64 now = perf_clock();
8474 u64 delta = now - event->ctx->timestamp;
8475 u64 time = event->ctx->time + delta;
8477 task_clock_event_update(event, time);
8480 static int task_clock_event_init(struct perf_event *event)
8482 if (event->attr.type != PERF_TYPE_SOFTWARE)
8485 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
8489 * no branch sampling for software events
8491 if (has_branch_stack(event))
8494 perf_swevent_init_hrtimer(event);
8499 static struct pmu perf_task_clock = {
8500 .task_ctx_nr = perf_sw_context,
8502 .capabilities = PERF_PMU_CAP_NO_NMI,
8504 .event_init = task_clock_event_init,
8505 .add = task_clock_event_add,
8506 .del = task_clock_event_del,
8507 .start = task_clock_event_start,
8508 .stop = task_clock_event_stop,
8509 .read = task_clock_event_read,
8512 static void perf_pmu_nop_void(struct pmu *pmu)
8516 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
8520 static int perf_pmu_nop_int(struct pmu *pmu)
8525 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
8527 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
8529 __this_cpu_write(nop_txn_flags, flags);
8531 if (flags & ~PERF_PMU_TXN_ADD)
8534 perf_pmu_disable(pmu);
8537 static int perf_pmu_commit_txn(struct pmu *pmu)
8539 unsigned int flags = __this_cpu_read(nop_txn_flags);
8541 __this_cpu_write(nop_txn_flags, 0);
8543 if (flags & ~PERF_PMU_TXN_ADD)
8546 perf_pmu_enable(pmu);
8550 static void perf_pmu_cancel_txn(struct pmu *pmu)
8552 unsigned int flags = __this_cpu_read(nop_txn_flags);
8554 __this_cpu_write(nop_txn_flags, 0);
8556 if (flags & ~PERF_PMU_TXN_ADD)
8559 perf_pmu_enable(pmu);
8562 static int perf_event_idx_default(struct perf_event *event)
8568 * Ensures all contexts with the same task_ctx_nr have the same
8569 * pmu_cpu_context too.
8571 static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
8578 list_for_each_entry(pmu, &pmus, entry) {
8579 if (pmu->task_ctx_nr == ctxn)
8580 return pmu->pmu_cpu_context;
8586 static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
8590 for_each_possible_cpu(cpu) {
8591 struct perf_cpu_context *cpuctx;
8593 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8595 if (cpuctx->unique_pmu == old_pmu)
8596 cpuctx->unique_pmu = pmu;
8600 static void free_pmu_context(struct pmu *pmu)
8604 mutex_lock(&pmus_lock);
8606 * Like a real lame refcount.
8608 list_for_each_entry(i, &pmus, entry) {
8609 if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
8610 update_pmu_context(i, pmu);
8615 free_percpu(pmu->pmu_cpu_context);
8617 mutex_unlock(&pmus_lock);
8621 * Let userspace know that this PMU supports address range filtering:
8623 static ssize_t nr_addr_filters_show(struct device *dev,
8624 struct device_attribute *attr,
8627 struct pmu *pmu = dev_get_drvdata(dev);
8629 return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters);
8631 DEVICE_ATTR_RO(nr_addr_filters);
8633 static struct idr pmu_idr;
8636 type_show(struct device *dev, struct device_attribute *attr, char *page)
8638 struct pmu *pmu = dev_get_drvdata(dev);
8640 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
8642 static DEVICE_ATTR_RO(type);
8645 perf_event_mux_interval_ms_show(struct device *dev,
8646 struct device_attribute *attr,
8649 struct pmu *pmu = dev_get_drvdata(dev);
8651 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
8654 static DEFINE_MUTEX(mux_interval_mutex);
8657 perf_event_mux_interval_ms_store(struct device *dev,
8658 struct device_attribute *attr,
8659 const char *buf, size_t count)
8661 struct pmu *pmu = dev_get_drvdata(dev);
8662 int timer, cpu, ret;
8664 ret = kstrtoint(buf, 0, &timer);
8671 /* same value, noting to do */
8672 if (timer == pmu->hrtimer_interval_ms)
8675 mutex_lock(&mux_interval_mutex);
8676 pmu->hrtimer_interval_ms = timer;
8678 /* update all cpuctx for this PMU */
8680 for_each_online_cpu(cpu) {
8681 struct perf_cpu_context *cpuctx;
8682 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8683 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
8685 cpu_function_call(cpu,
8686 (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
8689 mutex_unlock(&mux_interval_mutex);
8693 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
8695 static struct attribute *pmu_dev_attrs[] = {
8696 &dev_attr_type.attr,
8697 &dev_attr_perf_event_mux_interval_ms.attr,
8700 ATTRIBUTE_GROUPS(pmu_dev);
8702 static int pmu_bus_running;
8703 static struct bus_type pmu_bus = {
8704 .name = "event_source",
8705 .dev_groups = pmu_dev_groups,
8708 static void pmu_dev_release(struct device *dev)
8713 static int pmu_dev_alloc(struct pmu *pmu)
8717 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
8721 pmu->dev->groups = pmu->attr_groups;
8722 device_initialize(pmu->dev);
8723 ret = dev_set_name(pmu->dev, "%s", pmu->name);
8727 dev_set_drvdata(pmu->dev, pmu);
8728 pmu->dev->bus = &pmu_bus;
8729 pmu->dev->release = pmu_dev_release;
8730 ret = device_add(pmu->dev);
8734 /* For PMUs with address filters, throw in an extra attribute: */
8735 if (pmu->nr_addr_filters)
8736 ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
8745 device_del(pmu->dev);
8748 put_device(pmu->dev);
8752 static struct lock_class_key cpuctx_mutex;
8753 static struct lock_class_key cpuctx_lock;
8755 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
8759 mutex_lock(&pmus_lock);
8761 pmu->pmu_disable_count = alloc_percpu(int);
8762 if (!pmu->pmu_disable_count)
8771 type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
8779 if (pmu_bus_running) {
8780 ret = pmu_dev_alloc(pmu);
8786 if (pmu->task_ctx_nr == perf_hw_context) {
8787 static int hw_context_taken = 0;
8790 * Other than systems with heterogeneous CPUs, it never makes
8791 * sense for two PMUs to share perf_hw_context. PMUs which are
8792 * uncore must use perf_invalid_context.
8794 if (WARN_ON_ONCE(hw_context_taken &&
8795 !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS)))
8796 pmu->task_ctx_nr = perf_invalid_context;
8798 hw_context_taken = 1;
8801 pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
8802 if (pmu->pmu_cpu_context)
8803 goto got_cpu_context;
8806 pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
8807 if (!pmu->pmu_cpu_context)
8810 for_each_possible_cpu(cpu) {
8811 struct perf_cpu_context *cpuctx;
8813 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8814 __perf_event_init_context(&cpuctx->ctx);
8815 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
8816 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
8817 cpuctx->ctx.pmu = pmu;
8819 __perf_mux_hrtimer_init(cpuctx, cpu);
8821 cpuctx->unique_pmu = pmu;
8825 if (!pmu->start_txn) {
8826 if (pmu->pmu_enable) {
8828 * If we have pmu_enable/pmu_disable calls, install
8829 * transaction stubs that use that to try and batch
8830 * hardware accesses.
8832 pmu->start_txn = perf_pmu_start_txn;
8833 pmu->commit_txn = perf_pmu_commit_txn;
8834 pmu->cancel_txn = perf_pmu_cancel_txn;
8836 pmu->start_txn = perf_pmu_nop_txn;
8837 pmu->commit_txn = perf_pmu_nop_int;
8838 pmu->cancel_txn = perf_pmu_nop_void;
8842 if (!pmu->pmu_enable) {
8843 pmu->pmu_enable = perf_pmu_nop_void;
8844 pmu->pmu_disable = perf_pmu_nop_void;
8847 if (!pmu->event_idx)
8848 pmu->event_idx = perf_event_idx_default;
8850 list_add_rcu(&pmu->entry, &pmus);
8851 atomic_set(&pmu->exclusive_cnt, 0);
8854 mutex_unlock(&pmus_lock);
8859 device_del(pmu->dev);
8860 put_device(pmu->dev);
8863 if (pmu->type >= PERF_TYPE_MAX)
8864 idr_remove(&pmu_idr, pmu->type);
8867 free_percpu(pmu->pmu_disable_count);
8870 EXPORT_SYMBOL_GPL(perf_pmu_register);
8872 void perf_pmu_unregister(struct pmu *pmu)
8876 mutex_lock(&pmus_lock);
8877 remove_device = pmu_bus_running;
8878 list_del_rcu(&pmu->entry);
8879 mutex_unlock(&pmus_lock);
8882 * We dereference the pmu list under both SRCU and regular RCU, so
8883 * synchronize against both of those.
8885 synchronize_srcu(&pmus_srcu);
8888 free_percpu(pmu->pmu_disable_count);
8889 if (pmu->type >= PERF_TYPE_MAX)
8890 idr_remove(&pmu_idr, pmu->type);
8891 if (remove_device) {
8892 if (pmu->nr_addr_filters)
8893 device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
8894 device_del(pmu->dev);
8895 put_device(pmu->dev);
8897 free_pmu_context(pmu);
8899 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
8901 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
8903 struct perf_event_context *ctx = NULL;
8906 if (!try_module_get(pmu->module))
8909 if (event->group_leader != event) {
8911 * This ctx->mutex can nest when we're called through
8912 * inheritance. See the perf_event_ctx_lock_nested() comment.
8914 ctx = perf_event_ctx_lock_nested(event->group_leader,
8915 SINGLE_DEPTH_NESTING);
8920 ret = pmu->event_init(event);
8923 perf_event_ctx_unlock(event->group_leader, ctx);
8926 module_put(pmu->module);
8931 static struct pmu *perf_init_event(struct perf_event *event)
8933 struct pmu *pmu = NULL;
8937 idx = srcu_read_lock(&pmus_srcu);
8940 pmu = idr_find(&pmu_idr, event->attr.type);
8943 ret = perf_try_init_event(pmu, event);
8949 list_for_each_entry_rcu(pmu, &pmus, entry) {
8950 ret = perf_try_init_event(pmu, event);
8954 if (ret != -ENOENT) {
8959 pmu = ERR_PTR(-ENOENT);
8961 srcu_read_unlock(&pmus_srcu, idx);
8966 static void attach_sb_event(struct perf_event *event)
8968 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
8970 raw_spin_lock(&pel->lock);
8971 list_add_rcu(&event->sb_list, &pel->list);
8972 raw_spin_unlock(&pel->lock);
8976 * We keep a list of all !task (and therefore per-cpu) events
8977 * that need to receive side-band records.
8979 * This avoids having to scan all the various PMU per-cpu contexts
8982 static void account_pmu_sb_event(struct perf_event *event)
8984 if (is_sb_event(event))
8985 attach_sb_event(event);
8988 static void account_event_cpu(struct perf_event *event, int cpu)
8993 if (is_cgroup_event(event))
8994 atomic_inc(&per_cpu(perf_cgroup_events, cpu));
8997 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
8998 static void account_freq_event_nohz(void)
9000 #ifdef CONFIG_NO_HZ_FULL
9001 /* Lock so we don't race with concurrent unaccount */
9002 spin_lock(&nr_freq_lock);
9003 if (atomic_inc_return(&nr_freq_events) == 1)
9004 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
9005 spin_unlock(&nr_freq_lock);
9009 static void account_freq_event(void)
9011 if (tick_nohz_full_enabled())
9012 account_freq_event_nohz();
9014 atomic_inc(&nr_freq_events);
9018 static void account_event(struct perf_event *event)
9025 if (event->attach_state & PERF_ATTACH_TASK)
9027 if (event->attr.mmap || event->attr.mmap_data)
9028 atomic_inc(&nr_mmap_events);
9029 if (event->attr.comm)
9030 atomic_inc(&nr_comm_events);
9031 if (event->attr.task)
9032 atomic_inc(&nr_task_events);
9033 if (event->attr.freq)
9034 account_freq_event();
9035 if (event->attr.context_switch) {
9036 atomic_inc(&nr_switch_events);
9039 if (has_branch_stack(event))
9041 if (is_cgroup_event(event))
9045 if (atomic_inc_not_zero(&perf_sched_count))
9048 mutex_lock(&perf_sched_mutex);
9049 if (!atomic_read(&perf_sched_count)) {
9050 static_branch_enable(&perf_sched_events);
9052 * Guarantee that all CPUs observe they key change and
9053 * call the perf scheduling hooks before proceeding to
9054 * install events that need them.
9056 synchronize_sched();
9059 * Now that we have waited for the sync_sched(), allow further
9060 * increments to by-pass the mutex.
9062 atomic_inc(&perf_sched_count);
9063 mutex_unlock(&perf_sched_mutex);
9067 account_event_cpu(event, event->cpu);
9069 account_pmu_sb_event(event);
9073 * Allocate and initialize a event structure
9075 static struct perf_event *
9076 perf_event_alloc(struct perf_event_attr *attr, int cpu,
9077 struct task_struct *task,
9078 struct perf_event *group_leader,
9079 struct perf_event *parent_event,
9080 perf_overflow_handler_t overflow_handler,
9081 void *context, int cgroup_fd)
9084 struct perf_event *event;
9085 struct hw_perf_event *hwc;
9088 if ((unsigned)cpu >= nr_cpu_ids) {
9089 if (!task || cpu != -1)
9090 return ERR_PTR(-EINVAL);
9093 event = kzalloc(sizeof(*event), GFP_KERNEL);
9095 return ERR_PTR(-ENOMEM);
9098 * Single events are their own group leaders, with an
9099 * empty sibling list:
9102 group_leader = event;
9104 mutex_init(&event->child_mutex);
9105 INIT_LIST_HEAD(&event->child_list);
9107 INIT_LIST_HEAD(&event->group_entry);
9108 INIT_LIST_HEAD(&event->event_entry);
9109 INIT_LIST_HEAD(&event->sibling_list);
9110 INIT_LIST_HEAD(&event->rb_entry);
9111 INIT_LIST_HEAD(&event->active_entry);
9112 INIT_LIST_HEAD(&event->addr_filters.list);
9113 INIT_HLIST_NODE(&event->hlist_entry);
9116 init_waitqueue_head(&event->waitq);
9117 init_irq_work(&event->pending, perf_pending_event);
9119 mutex_init(&event->mmap_mutex);
9120 raw_spin_lock_init(&event->addr_filters.lock);
9122 atomic_long_set(&event->refcount, 1);
9124 event->attr = *attr;
9125 event->group_leader = group_leader;
9129 event->parent = parent_event;
9131 event->ns = get_pid_ns(task_active_pid_ns(current));
9132 event->id = atomic64_inc_return(&perf_event_id);
9134 event->state = PERF_EVENT_STATE_INACTIVE;
9137 event->attach_state = PERF_ATTACH_TASK;
9139 * XXX pmu::event_init needs to know what task to account to
9140 * and we cannot use the ctx information because we need the
9141 * pmu before we get a ctx.
9143 event->hw.target = task;
9146 event->clock = &local_clock;
9148 event->clock = parent_event->clock;
9150 if (!overflow_handler && parent_event) {
9151 overflow_handler = parent_event->overflow_handler;
9152 context = parent_event->overflow_handler_context;
9153 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9154 if (overflow_handler == bpf_overflow_handler) {
9155 struct bpf_prog *prog = bpf_prog_inc(parent_event->prog);
9158 err = PTR_ERR(prog);
9162 event->orig_overflow_handler =
9163 parent_event->orig_overflow_handler;
9168 if (overflow_handler) {
9169 event->overflow_handler = overflow_handler;
9170 event->overflow_handler_context = context;
9171 } else if (is_write_backward(event)){
9172 event->overflow_handler = perf_event_output_backward;
9173 event->overflow_handler_context = NULL;
9175 event->overflow_handler = perf_event_output_forward;
9176 event->overflow_handler_context = NULL;
9179 perf_event__state_init(event);
9184 hwc->sample_period = attr->sample_period;
9185 if (attr->freq && attr->sample_freq)
9186 hwc->sample_period = 1;
9187 hwc->last_period = hwc->sample_period;
9189 local64_set(&hwc->period_left, hwc->sample_period);
9192 * we currently do not support PERF_FORMAT_GROUP on inherited events
9194 if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
9197 if (!has_branch_stack(event))
9198 event->attr.branch_sample_type = 0;
9200 if (cgroup_fd != -1) {
9201 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
9206 pmu = perf_init_event(event);
9209 else if (IS_ERR(pmu)) {
9214 err = exclusive_event_init(event);
9218 if (has_addr_filter(event)) {
9219 event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
9220 sizeof(unsigned long),
9222 if (!event->addr_filters_offs)
9225 /* force hw sync on the address filters */
9226 event->addr_filters_gen = 1;
9229 if (!event->parent) {
9230 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
9231 err = get_callchain_buffers(attr->sample_max_stack);
9233 goto err_addr_filters;
9237 /* symmetric to unaccount_event() in _free_event() */
9238 account_event(event);
9243 kfree(event->addr_filters_offs);
9246 exclusive_event_destroy(event);
9250 event->destroy(event);
9251 module_put(pmu->module);
9253 if (is_cgroup_event(event))
9254 perf_detach_cgroup(event);
9256 put_pid_ns(event->ns);
9259 return ERR_PTR(err);
9262 static int perf_copy_attr(struct perf_event_attr __user *uattr,
9263 struct perf_event_attr *attr)
9268 if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
9272 * zero the full structure, so that a short copy will be nice.
9274 memset(attr, 0, sizeof(*attr));
9276 ret = get_user(size, &uattr->size);
9280 if (size > PAGE_SIZE) /* silly large */
9283 if (!size) /* abi compat */
9284 size = PERF_ATTR_SIZE_VER0;
9286 if (size < PERF_ATTR_SIZE_VER0)
9290 * If we're handed a bigger struct than we know of,
9291 * ensure all the unknown bits are 0 - i.e. new
9292 * user-space does not rely on any kernel feature
9293 * extensions we dont know about yet.
9295 if (size > sizeof(*attr)) {
9296 unsigned char __user *addr;
9297 unsigned char __user *end;
9300 addr = (void __user *)uattr + sizeof(*attr);
9301 end = (void __user *)uattr + size;
9303 for (; addr < end; addr++) {
9304 ret = get_user(val, addr);
9310 size = sizeof(*attr);
9313 ret = copy_from_user(attr, uattr, size);
9317 if (attr->__reserved_1)
9320 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
9323 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
9326 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
9327 u64 mask = attr->branch_sample_type;
9329 /* only using defined bits */
9330 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
9333 /* at least one branch bit must be set */
9334 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
9337 /* propagate priv level, when not set for branch */
9338 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
9340 /* exclude_kernel checked on syscall entry */
9341 if (!attr->exclude_kernel)
9342 mask |= PERF_SAMPLE_BRANCH_KERNEL;
9344 if (!attr->exclude_user)
9345 mask |= PERF_SAMPLE_BRANCH_USER;
9347 if (!attr->exclude_hv)
9348 mask |= PERF_SAMPLE_BRANCH_HV;
9350 * adjust user setting (for HW filter setup)
9352 attr->branch_sample_type = mask;
9354 /* privileged levels capture (kernel, hv): check permissions */
9355 if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
9356 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9360 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
9361 ret = perf_reg_validate(attr->sample_regs_user);
9366 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
9367 if (!arch_perf_have_user_stack_dump())
9371 * We have __u32 type for the size, but so far
9372 * we can only use __u16 as maximum due to the
9373 * __u16 sample size limit.
9375 if (attr->sample_stack_user >= USHRT_MAX)
9377 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
9381 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
9382 ret = perf_reg_validate(attr->sample_regs_intr);
9387 put_user(sizeof(*attr), &uattr->size);
9393 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
9395 struct ring_buffer *rb = NULL;
9401 /* don't allow circular references */
9402 if (event == output_event)
9406 * Don't allow cross-cpu buffers
9408 if (output_event->cpu != event->cpu)
9412 * If its not a per-cpu rb, it must be the same task.
9414 if (output_event->cpu == -1 && output_event->ctx != event->ctx)
9418 * Mixing clocks in the same buffer is trouble you don't need.
9420 if (output_event->clock != event->clock)
9424 * Either writing ring buffer from beginning or from end.
9425 * Mixing is not allowed.
9427 if (is_write_backward(output_event) != is_write_backward(event))
9431 * If both events generate aux data, they must be on the same PMU
9433 if (has_aux(event) && has_aux(output_event) &&
9434 event->pmu != output_event->pmu)
9438 mutex_lock(&event->mmap_mutex);
9439 /* Can't redirect output if we've got an active mmap() */
9440 if (atomic_read(&event->mmap_count))
9444 /* get the rb we want to redirect to */
9445 rb = ring_buffer_get(output_event);
9450 ring_buffer_attach(event, rb);
9454 mutex_unlock(&event->mmap_mutex);
9460 static void mutex_lock_double(struct mutex *a, struct mutex *b)
9466 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
9469 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
9471 bool nmi_safe = false;
9474 case CLOCK_MONOTONIC:
9475 event->clock = &ktime_get_mono_fast_ns;
9479 case CLOCK_MONOTONIC_RAW:
9480 event->clock = &ktime_get_raw_fast_ns;
9484 case CLOCK_REALTIME:
9485 event->clock = &ktime_get_real_ns;
9488 case CLOCK_BOOTTIME:
9489 event->clock = &ktime_get_boot_ns;
9493 event->clock = &ktime_get_tai_ns;
9500 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
9507 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9509 * @attr_uptr: event_id type attributes for monitoring/sampling
9512 * @group_fd: group leader event fd
9514 SYSCALL_DEFINE5(perf_event_open,
9515 struct perf_event_attr __user *, attr_uptr,
9516 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
9518 struct perf_event *group_leader = NULL, *output_event = NULL;
9519 struct perf_event *event, *sibling;
9520 struct perf_event_attr attr;
9521 struct perf_event_context *ctx, *uninitialized_var(gctx);
9522 struct file *event_file = NULL;
9523 struct fd group = {NULL, 0};
9524 struct task_struct *task = NULL;
9529 int f_flags = O_RDWR;
9532 /* for future expandability... */
9533 if (flags & ~PERF_FLAG_ALL)
9536 err = perf_copy_attr(attr_uptr, &attr);
9540 if (!attr.exclude_kernel) {
9541 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9546 if (attr.sample_freq > sysctl_perf_event_sample_rate)
9549 if (attr.sample_period & (1ULL << 63))
9553 if (!attr.sample_max_stack)
9554 attr.sample_max_stack = sysctl_perf_event_max_stack;
9557 * In cgroup mode, the pid argument is used to pass the fd
9558 * opened to the cgroup directory in cgroupfs. The cpu argument
9559 * designates the cpu on which to monitor threads from that
9562 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
9565 if (flags & PERF_FLAG_FD_CLOEXEC)
9566 f_flags |= O_CLOEXEC;
9568 event_fd = get_unused_fd_flags(f_flags);
9572 if (group_fd != -1) {
9573 err = perf_fget_light(group_fd, &group);
9576 group_leader = group.file->private_data;
9577 if (flags & PERF_FLAG_FD_OUTPUT)
9578 output_event = group_leader;
9579 if (flags & PERF_FLAG_FD_NO_GROUP)
9580 group_leader = NULL;
9583 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
9584 task = find_lively_task_by_vpid(pid);
9586 err = PTR_ERR(task);
9591 if (task && group_leader &&
9592 group_leader->attr.inherit != attr.inherit) {
9600 err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
9605 * Reuse ptrace permission checks for now.
9607 * We must hold cred_guard_mutex across this and any potential
9608 * perf_install_in_context() call for this new event to
9609 * serialize against exec() altering our credentials (and the
9610 * perf_event_exit_task() that could imply).
9613 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
9617 if (flags & PERF_FLAG_PID_CGROUP)
9620 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
9621 NULL, NULL, cgroup_fd);
9622 if (IS_ERR(event)) {
9623 err = PTR_ERR(event);
9627 if (is_sampling_event(event)) {
9628 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
9635 * Special case software events and allow them to be part of
9636 * any hardware group.
9640 if (attr.use_clockid) {
9641 err = perf_event_set_clock(event, attr.clockid);
9646 if (pmu->task_ctx_nr == perf_sw_context)
9647 event->event_caps |= PERF_EV_CAP_SOFTWARE;
9650 (is_software_event(event) != is_software_event(group_leader))) {
9651 if (is_software_event(event)) {
9653 * If event and group_leader are not both a software
9654 * event, and event is, then group leader is not.
9656 * Allow the addition of software events to !software
9657 * groups, this is safe because software events never
9660 pmu = group_leader->pmu;
9661 } else if (is_software_event(group_leader) &&
9662 (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
9664 * In case the group is a pure software group, and we
9665 * try to add a hardware event, move the whole group to
9666 * the hardware context.
9673 * Get the target context (task or percpu):
9675 ctx = find_get_context(pmu, task, event);
9681 if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) {
9687 * Look up the group leader (we will attach this event to it):
9693 * Do not allow a recursive hierarchy (this new sibling
9694 * becoming part of another group-sibling):
9696 if (group_leader->group_leader != group_leader)
9699 /* All events in a group should have the same clock */
9700 if (group_leader->clock != event->clock)
9704 * Do not allow to attach to a group in a different
9705 * task or CPU context:
9709 * Make sure we're both on the same task, or both
9712 if (group_leader->ctx->task != ctx->task)
9716 * Make sure we're both events for the same CPU;
9717 * grouping events for different CPUs is broken; since
9718 * you can never concurrently schedule them anyhow.
9720 if (group_leader->cpu != event->cpu)
9723 if (group_leader->ctx != ctx)
9728 * Only a group leader can be exclusive or pinned
9730 if (attr.exclusive || attr.pinned)
9735 err = perf_event_set_output(event, output_event);
9740 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
9742 if (IS_ERR(event_file)) {
9743 err = PTR_ERR(event_file);
9749 gctx = group_leader->ctx;
9750 mutex_lock_double(&gctx->mutex, &ctx->mutex);
9751 if (gctx->task == TASK_TOMBSTONE) {
9756 mutex_lock(&ctx->mutex);
9759 if (ctx->task == TASK_TOMBSTONE) {
9764 if (!perf_event_validate_size(event)) {
9770 * Must be under the same ctx::mutex as perf_install_in_context(),
9771 * because we need to serialize with concurrent event creation.
9773 if (!exclusive_event_installable(event, ctx)) {
9774 /* exclusive and group stuff are assumed mutually exclusive */
9775 WARN_ON_ONCE(move_group);
9781 WARN_ON_ONCE(ctx->parent_ctx);
9784 * This is the point on no return; we cannot fail hereafter. This is
9785 * where we start modifying current state.
9790 * See perf_event_ctx_lock() for comments on the details
9791 * of swizzling perf_event::ctx.
9793 perf_remove_from_context(group_leader, 0);
9795 list_for_each_entry(sibling, &group_leader->sibling_list,
9797 perf_remove_from_context(sibling, 0);
9802 * Wait for everybody to stop referencing the events through
9803 * the old lists, before installing it on new lists.
9808 * Install the group siblings before the group leader.
9810 * Because a group leader will try and install the entire group
9811 * (through the sibling list, which is still in-tact), we can
9812 * end up with siblings installed in the wrong context.
9814 * By installing siblings first we NO-OP because they're not
9815 * reachable through the group lists.
9817 list_for_each_entry(sibling, &group_leader->sibling_list,
9819 perf_event__state_init(sibling);
9820 perf_install_in_context(ctx, sibling, sibling->cpu);
9825 * Removing from the context ends up with disabled
9826 * event. What we want here is event in the initial
9827 * startup state, ready to be add into new context.
9829 perf_event__state_init(group_leader);
9830 perf_install_in_context(ctx, group_leader, group_leader->cpu);
9834 * Now that all events are installed in @ctx, nothing
9835 * references @gctx anymore, so drop the last reference we have
9842 * Precalculate sample_data sizes; do while holding ctx::mutex such
9843 * that we're serialized against further additions and before
9844 * perf_install_in_context() which is the point the event is active and
9845 * can use these values.
9847 perf_event__header_size(event);
9848 perf_event__id_header_size(event);
9850 event->owner = current;
9852 perf_install_in_context(ctx, event, event->cpu);
9853 perf_unpin_context(ctx);
9856 mutex_unlock(&gctx->mutex);
9857 mutex_unlock(&ctx->mutex);
9860 mutex_unlock(&task->signal->cred_guard_mutex);
9861 put_task_struct(task);
9866 mutex_lock(¤t->perf_event_mutex);
9867 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
9868 mutex_unlock(¤t->perf_event_mutex);
9871 * Drop the reference on the group_event after placing the
9872 * new event on the sibling_list. This ensures destruction
9873 * of the group leader will find the pointer to itself in
9874 * perf_group_detach().
9877 fd_install(event_fd, event_file);
9882 mutex_unlock(&gctx->mutex);
9883 mutex_unlock(&ctx->mutex);
9887 perf_unpin_context(ctx);
9891 * If event_file is set, the fput() above will have called ->release()
9892 * and that will take care of freeing the event.
9898 mutex_unlock(&task->signal->cred_guard_mutex);
9903 put_task_struct(task);
9907 put_unused_fd(event_fd);
9912 * perf_event_create_kernel_counter
9914 * @attr: attributes of the counter to create
9915 * @cpu: cpu in which the counter is bound
9916 * @task: task to profile (NULL for percpu)
9919 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
9920 struct task_struct *task,
9921 perf_overflow_handler_t overflow_handler,
9924 struct perf_event_context *ctx;
9925 struct perf_event *event;
9929 * Get the target context (task or percpu):
9932 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
9933 overflow_handler, context, -1);
9934 if (IS_ERR(event)) {
9935 err = PTR_ERR(event);
9939 /* Mark owner so we could distinguish it from user events. */
9940 event->owner = TASK_TOMBSTONE;
9942 ctx = find_get_context(event->pmu, task, event);
9948 WARN_ON_ONCE(ctx->parent_ctx);
9949 mutex_lock(&ctx->mutex);
9950 if (ctx->task == TASK_TOMBSTONE) {
9955 if (!exclusive_event_installable(event, ctx)) {
9960 perf_install_in_context(ctx, event, cpu);
9961 perf_unpin_context(ctx);
9962 mutex_unlock(&ctx->mutex);
9967 mutex_unlock(&ctx->mutex);
9968 perf_unpin_context(ctx);
9973 return ERR_PTR(err);
9975 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
9977 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
9979 struct perf_event_context *src_ctx;
9980 struct perf_event_context *dst_ctx;
9981 struct perf_event *event, *tmp;
9984 src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
9985 dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
9988 * See perf_event_ctx_lock() for comments on the details
9989 * of swizzling perf_event::ctx.
9991 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
9992 list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
9994 perf_remove_from_context(event, 0);
9995 unaccount_event_cpu(event, src_cpu);
9997 list_add(&event->migrate_entry, &events);
10001 * Wait for the events to quiesce before re-instating them.
10006 * Re-instate events in 2 passes.
10008 * Skip over group leaders and only install siblings on this first
10009 * pass, siblings will not get enabled without a leader, however a
10010 * leader will enable its siblings, even if those are still on the old
10013 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
10014 if (event->group_leader == event)
10017 list_del(&event->migrate_entry);
10018 if (event->state >= PERF_EVENT_STATE_OFF)
10019 event->state = PERF_EVENT_STATE_INACTIVE;
10020 account_event_cpu(event, dst_cpu);
10021 perf_install_in_context(dst_ctx, event, dst_cpu);
10026 * Once all the siblings are setup properly, install the group leaders
10029 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
10030 list_del(&event->migrate_entry);
10031 if (event->state >= PERF_EVENT_STATE_OFF)
10032 event->state = PERF_EVENT_STATE_INACTIVE;
10033 account_event_cpu(event, dst_cpu);
10034 perf_install_in_context(dst_ctx, event, dst_cpu);
10037 mutex_unlock(&dst_ctx->mutex);
10038 mutex_unlock(&src_ctx->mutex);
10040 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
10042 static void sync_child_event(struct perf_event *child_event,
10043 struct task_struct *child)
10045 struct perf_event *parent_event = child_event->parent;
10048 if (child_event->attr.inherit_stat)
10049 perf_event_read_event(child_event, child);
10051 child_val = perf_event_count(child_event);
10054 * Add back the child's count to the parent's count:
10056 atomic64_add(child_val, &parent_event->child_count);
10057 atomic64_add(child_event->total_time_enabled,
10058 &parent_event->child_total_time_enabled);
10059 atomic64_add(child_event->total_time_running,
10060 &parent_event->child_total_time_running);
10064 perf_event_exit_event(struct perf_event *child_event,
10065 struct perf_event_context *child_ctx,
10066 struct task_struct *child)
10068 struct perf_event *parent_event = child_event->parent;
10071 * Do not destroy the 'original' grouping; because of the context
10072 * switch optimization the original events could've ended up in a
10073 * random child task.
10075 * If we were to destroy the original group, all group related
10076 * operations would cease to function properly after this random
10079 * Do destroy all inherited groups, we don't care about those
10080 * and being thorough is better.
10082 raw_spin_lock_irq(&child_ctx->lock);
10083 WARN_ON_ONCE(child_ctx->is_active);
10086 perf_group_detach(child_event);
10087 list_del_event(child_event, child_ctx);
10088 child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
10089 raw_spin_unlock_irq(&child_ctx->lock);
10092 * Parent events are governed by their filedesc, retain them.
10094 if (!parent_event) {
10095 perf_event_wakeup(child_event);
10099 * Child events can be cleaned up.
10102 sync_child_event(child_event, child);
10105 * Remove this event from the parent's list
10107 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
10108 mutex_lock(&parent_event->child_mutex);
10109 list_del_init(&child_event->child_list);
10110 mutex_unlock(&parent_event->child_mutex);
10113 * Kick perf_poll() for is_event_hup().
10115 perf_event_wakeup(parent_event);
10116 free_event(child_event);
10117 put_event(parent_event);
10120 static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
10122 struct perf_event_context *child_ctx, *clone_ctx = NULL;
10123 struct perf_event *child_event, *next;
10125 WARN_ON_ONCE(child != current);
10127 child_ctx = perf_pin_task_context(child, ctxn);
10132 * In order to reduce the amount of tricky in ctx tear-down, we hold
10133 * ctx::mutex over the entire thing. This serializes against almost
10134 * everything that wants to access the ctx.
10136 * The exception is sys_perf_event_open() /
10137 * perf_event_create_kernel_count() which does find_get_context()
10138 * without ctx::mutex (it cannot because of the move_group double mutex
10139 * lock thing). See the comments in perf_install_in_context().
10141 mutex_lock(&child_ctx->mutex);
10144 * In a single ctx::lock section, de-schedule the events and detach the
10145 * context from the task such that we cannot ever get it scheduled back
10148 raw_spin_lock_irq(&child_ctx->lock);
10149 task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx);
10152 * Now that the context is inactive, destroy the task <-> ctx relation
10153 * and mark the context dead.
10155 RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL);
10156 put_ctx(child_ctx); /* cannot be last */
10157 WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
10158 put_task_struct(current); /* cannot be last */
10160 clone_ctx = unclone_ctx(child_ctx);
10161 raw_spin_unlock_irq(&child_ctx->lock);
10164 put_ctx(clone_ctx);
10167 * Report the task dead after unscheduling the events so that we
10168 * won't get any samples after PERF_RECORD_EXIT. We can however still
10169 * get a few PERF_RECORD_READ events.
10171 perf_event_task(child, child_ctx, 0);
10173 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
10174 perf_event_exit_event(child_event, child_ctx, child);
10176 mutex_unlock(&child_ctx->mutex);
10178 put_ctx(child_ctx);
10182 * When a child task exits, feed back event values to parent events.
10184 * Can be called with cred_guard_mutex held when called from
10185 * install_exec_creds().
10187 void perf_event_exit_task(struct task_struct *child)
10189 struct perf_event *event, *tmp;
10192 mutex_lock(&child->perf_event_mutex);
10193 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
10195 list_del_init(&event->owner_entry);
10198 * Ensure the list deletion is visible before we clear
10199 * the owner, closes a race against perf_release() where
10200 * we need to serialize on the owner->perf_event_mutex.
10202 smp_store_release(&event->owner, NULL);
10204 mutex_unlock(&child->perf_event_mutex);
10206 for_each_task_context_nr(ctxn)
10207 perf_event_exit_task_context(child, ctxn);
10210 * The perf_event_exit_task_context calls perf_event_task
10211 * with child's task_ctx, which generates EXIT events for
10212 * child contexts and sets child->perf_event_ctxp[] to NULL.
10213 * At this point we need to send EXIT events to cpu contexts.
10215 perf_event_task(child, NULL, 0);
10218 static void perf_free_event(struct perf_event *event,
10219 struct perf_event_context *ctx)
10221 struct perf_event *parent = event->parent;
10223 if (WARN_ON_ONCE(!parent))
10226 mutex_lock(&parent->child_mutex);
10227 list_del_init(&event->child_list);
10228 mutex_unlock(&parent->child_mutex);
10232 raw_spin_lock_irq(&ctx->lock);
10233 perf_group_detach(event);
10234 list_del_event(event, ctx);
10235 raw_spin_unlock_irq(&ctx->lock);
10240 * Free an unexposed, unused context as created by inheritance by
10241 * perf_event_init_task below, used by fork() in case of fail.
10243 * Not all locks are strictly required, but take them anyway to be nice and
10244 * help out with the lockdep assertions.
10246 void perf_event_free_task(struct task_struct *task)
10248 struct perf_event_context *ctx;
10249 struct perf_event *event, *tmp;
10252 for_each_task_context_nr(ctxn) {
10253 ctx = task->perf_event_ctxp[ctxn];
10257 mutex_lock(&ctx->mutex);
10259 list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
10261 perf_free_event(event, ctx);
10263 list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
10265 perf_free_event(event, ctx);
10267 if (!list_empty(&ctx->pinned_groups) ||
10268 !list_empty(&ctx->flexible_groups))
10271 mutex_unlock(&ctx->mutex);
10277 void perf_event_delayed_put(struct task_struct *task)
10281 for_each_task_context_nr(ctxn)
10282 WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
10285 struct file *perf_event_get(unsigned int fd)
10289 file = fget_raw(fd);
10291 return ERR_PTR(-EBADF);
10293 if (file->f_op != &perf_fops) {
10295 return ERR_PTR(-EBADF);
10301 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
10304 return ERR_PTR(-EINVAL);
10306 return &event->attr;
10310 * inherit a event from parent task to child task:
10312 static struct perf_event *
10313 inherit_event(struct perf_event *parent_event,
10314 struct task_struct *parent,
10315 struct perf_event_context *parent_ctx,
10316 struct task_struct *child,
10317 struct perf_event *group_leader,
10318 struct perf_event_context *child_ctx)
10320 enum perf_event_active_state parent_state = parent_event->state;
10321 struct perf_event *child_event;
10322 unsigned long flags;
10325 * Instead of creating recursive hierarchies of events,
10326 * we link inherited events back to the original parent,
10327 * which has a filp for sure, which we use as the reference
10330 if (parent_event->parent)
10331 parent_event = parent_event->parent;
10333 child_event = perf_event_alloc(&parent_event->attr,
10336 group_leader, parent_event,
10338 if (IS_ERR(child_event))
10339 return child_event;
10342 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10343 * must be under the same lock in order to serialize against
10344 * perf_event_release_kernel(), such that either we must observe
10345 * is_orphaned_event() or they will observe us on the child_list.
10347 mutex_lock(&parent_event->child_mutex);
10348 if (is_orphaned_event(parent_event) ||
10349 !atomic_long_inc_not_zero(&parent_event->refcount)) {
10350 mutex_unlock(&parent_event->child_mutex);
10351 free_event(child_event);
10355 get_ctx(child_ctx);
10358 * Make the child state follow the state of the parent event,
10359 * not its attr.disabled bit. We hold the parent's mutex,
10360 * so we won't race with perf_event_{en, dis}able_family.
10362 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
10363 child_event->state = PERF_EVENT_STATE_INACTIVE;
10365 child_event->state = PERF_EVENT_STATE_OFF;
10367 if (parent_event->attr.freq) {
10368 u64 sample_period = parent_event->hw.sample_period;
10369 struct hw_perf_event *hwc = &child_event->hw;
10371 hwc->sample_period = sample_period;
10372 hwc->last_period = sample_period;
10374 local64_set(&hwc->period_left, sample_period);
10377 child_event->ctx = child_ctx;
10378 child_event->overflow_handler = parent_event->overflow_handler;
10379 child_event->overflow_handler_context
10380 = parent_event->overflow_handler_context;
10383 * Precalculate sample_data sizes
10385 perf_event__header_size(child_event);
10386 perf_event__id_header_size(child_event);
10389 * Link it up in the child's context:
10391 raw_spin_lock_irqsave(&child_ctx->lock, flags);
10392 add_event_to_ctx(child_event, child_ctx);
10393 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
10396 * Link this into the parent event's child list
10398 list_add_tail(&child_event->child_list, &parent_event->child_list);
10399 mutex_unlock(&parent_event->child_mutex);
10401 return child_event;
10404 static int inherit_group(struct perf_event *parent_event,
10405 struct task_struct *parent,
10406 struct perf_event_context *parent_ctx,
10407 struct task_struct *child,
10408 struct perf_event_context *child_ctx)
10410 struct perf_event *leader;
10411 struct perf_event *sub;
10412 struct perf_event *child_ctr;
10414 leader = inherit_event(parent_event, parent, parent_ctx,
10415 child, NULL, child_ctx);
10416 if (IS_ERR(leader))
10417 return PTR_ERR(leader);
10418 list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
10419 child_ctr = inherit_event(sub, parent, parent_ctx,
10420 child, leader, child_ctx);
10421 if (IS_ERR(child_ctr))
10422 return PTR_ERR(child_ctr);
10428 inherit_task_group(struct perf_event *event, struct task_struct *parent,
10429 struct perf_event_context *parent_ctx,
10430 struct task_struct *child, int ctxn,
10431 int *inherited_all)
10434 struct perf_event_context *child_ctx;
10436 if (!event->attr.inherit) {
10437 *inherited_all = 0;
10441 child_ctx = child->perf_event_ctxp[ctxn];
10444 * This is executed from the parent task context, so
10445 * inherit events that have been marked for cloning.
10446 * First allocate and initialize a context for the
10450 child_ctx = alloc_perf_context(parent_ctx->pmu, child);
10454 child->perf_event_ctxp[ctxn] = child_ctx;
10457 ret = inherit_group(event, parent, parent_ctx,
10461 *inherited_all = 0;
10467 * Initialize the perf_event context in task_struct
10469 static int perf_event_init_context(struct task_struct *child, int ctxn)
10471 struct perf_event_context *child_ctx, *parent_ctx;
10472 struct perf_event_context *cloned_ctx;
10473 struct perf_event *event;
10474 struct task_struct *parent = current;
10475 int inherited_all = 1;
10476 unsigned long flags;
10479 if (likely(!parent->perf_event_ctxp[ctxn]))
10483 * If the parent's context is a clone, pin it so it won't get
10484 * swapped under us.
10486 parent_ctx = perf_pin_task_context(parent, ctxn);
10491 * No need to check if parent_ctx != NULL here; since we saw
10492 * it non-NULL earlier, the only reason for it to become NULL
10493 * is if we exit, and since we're currently in the middle of
10494 * a fork we can't be exiting at the same time.
10498 * Lock the parent list. No need to lock the child - not PID
10499 * hashed yet and not running, so nobody can access it.
10501 mutex_lock(&parent_ctx->mutex);
10504 * We dont have to disable NMIs - we are only looking at
10505 * the list, not manipulating it:
10507 list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
10508 ret = inherit_task_group(event, parent, parent_ctx,
10509 child, ctxn, &inherited_all);
10515 * We can't hold ctx->lock when iterating the ->flexible_group list due
10516 * to allocations, but we need to prevent rotation because
10517 * rotate_ctx() will change the list from interrupt context.
10519 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10520 parent_ctx->rotate_disable = 1;
10521 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10523 list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
10524 ret = inherit_task_group(event, parent, parent_ctx,
10525 child, ctxn, &inherited_all);
10530 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10531 parent_ctx->rotate_disable = 0;
10533 child_ctx = child->perf_event_ctxp[ctxn];
10535 if (child_ctx && inherited_all) {
10537 * Mark the child context as a clone of the parent
10538 * context, or of whatever the parent is a clone of.
10540 * Note that if the parent is a clone, the holding of
10541 * parent_ctx->lock avoids it from being uncloned.
10543 cloned_ctx = parent_ctx->parent_ctx;
10545 child_ctx->parent_ctx = cloned_ctx;
10546 child_ctx->parent_gen = parent_ctx->parent_gen;
10548 child_ctx->parent_ctx = parent_ctx;
10549 child_ctx->parent_gen = parent_ctx->generation;
10551 get_ctx(child_ctx->parent_ctx);
10554 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10555 mutex_unlock(&parent_ctx->mutex);
10557 perf_unpin_context(parent_ctx);
10558 put_ctx(parent_ctx);
10564 * Initialize the perf_event context in task_struct
10566 int perf_event_init_task(struct task_struct *child)
10570 memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
10571 mutex_init(&child->perf_event_mutex);
10572 INIT_LIST_HEAD(&child->perf_event_list);
10574 for_each_task_context_nr(ctxn) {
10575 ret = perf_event_init_context(child, ctxn);
10577 perf_event_free_task(child);
10585 static void __init perf_event_init_all_cpus(void)
10587 struct swevent_htable *swhash;
10590 for_each_possible_cpu(cpu) {
10591 swhash = &per_cpu(swevent_htable, cpu);
10592 mutex_init(&swhash->hlist_mutex);
10593 INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
10595 INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
10596 raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
10598 INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
10602 int perf_event_init_cpu(unsigned int cpu)
10604 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
10606 mutex_lock(&swhash->hlist_mutex);
10607 if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
10608 struct swevent_hlist *hlist;
10610 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
10612 rcu_assign_pointer(swhash->swevent_hlist, hlist);
10614 mutex_unlock(&swhash->hlist_mutex);
10618 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10619 static void __perf_event_exit_context(void *__info)
10621 struct perf_event_context *ctx = __info;
10622 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
10623 struct perf_event *event;
10625 raw_spin_lock(&ctx->lock);
10626 list_for_each_entry(event, &ctx->event_list, event_entry)
10627 __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
10628 raw_spin_unlock(&ctx->lock);
10631 static void perf_event_exit_cpu_context(int cpu)
10633 struct perf_event_context *ctx;
10637 idx = srcu_read_lock(&pmus_srcu);
10638 list_for_each_entry_rcu(pmu, &pmus, entry) {
10639 ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
10641 mutex_lock(&ctx->mutex);
10642 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
10643 mutex_unlock(&ctx->mutex);
10645 srcu_read_unlock(&pmus_srcu, idx);
10649 static void perf_event_exit_cpu_context(int cpu) { }
10653 int perf_event_exit_cpu(unsigned int cpu)
10655 perf_event_exit_cpu_context(cpu);
10660 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
10664 for_each_online_cpu(cpu)
10665 perf_event_exit_cpu(cpu);
10671 * Run the perf reboot notifier at the very last possible moment so that
10672 * the generic watchdog code runs as long as possible.
10674 static struct notifier_block perf_reboot_notifier = {
10675 .notifier_call = perf_reboot,
10676 .priority = INT_MIN,
10679 void __init perf_event_init(void)
10683 idr_init(&pmu_idr);
10685 perf_event_init_all_cpus();
10686 init_srcu_struct(&pmus_srcu);
10687 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
10688 perf_pmu_register(&perf_cpu_clock, NULL, -1);
10689 perf_pmu_register(&perf_task_clock, NULL, -1);
10690 perf_tp_register();
10691 perf_event_init_cpu(smp_processor_id());
10692 register_reboot_notifier(&perf_reboot_notifier);
10694 ret = init_hw_breakpoint();
10695 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
10698 * Build time assertion that we keep the data_head at the intended
10699 * location. IOW, validation we got the __reserved[] size right.
10701 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
10705 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
10708 struct perf_pmu_events_attr *pmu_attr =
10709 container_of(attr, struct perf_pmu_events_attr, attr);
10711 if (pmu_attr->event_str)
10712 return sprintf(page, "%s\n", pmu_attr->event_str);
10716 EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
10718 static int __init perf_event_sysfs_init(void)
10723 mutex_lock(&pmus_lock);
10725 ret = bus_register(&pmu_bus);
10729 list_for_each_entry(pmu, &pmus, entry) {
10730 if (!pmu->name || pmu->type < 0)
10733 ret = pmu_dev_alloc(pmu);
10734 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
10736 pmu_bus_running = 1;
10740 mutex_unlock(&pmus_lock);
10744 device_initcall(perf_event_sysfs_init);
10746 #ifdef CONFIG_CGROUP_PERF
10747 static struct cgroup_subsys_state *
10748 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
10750 struct perf_cgroup *jc;
10752 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
10754 return ERR_PTR(-ENOMEM);
10756 jc->info = alloc_percpu(struct perf_cgroup_info);
10759 return ERR_PTR(-ENOMEM);
10765 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
10767 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
10769 free_percpu(jc->info);
10773 static int __perf_cgroup_move(void *info)
10775 struct task_struct *task = info;
10777 perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
10782 static void perf_cgroup_attach(struct cgroup_taskset *tset)
10784 struct task_struct *task;
10785 struct cgroup_subsys_state *css;
10787 cgroup_taskset_for_each(task, css, tset)
10788 task_function_call(task, __perf_cgroup_move, task);
10791 struct cgroup_subsys perf_event_cgrp_subsys = {
10792 .css_alloc = perf_cgroup_css_alloc,
10793 .css_free = perf_cgroup_css_free,
10794 .attach = perf_cgroup_attach,
10796 #endif /* CONFIG_CGROUP_PERF */