1 // SPDX-License-Identifier: GPL-2.0
3 * Performance events core code:
5 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
6 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
7 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
8 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <linux/idr.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/hash.h>
20 #include <linux/tick.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/hugetlb.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>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
53 #include <linux/min_heap.h>
54 #include <linux/highmem.h>
55 #include <linux/pgtable.h>
56 #include <linux/buildid.h>
57 #include <linux/task_work.h>
61 #include <asm/irq_regs.h>
63 typedef int (*remote_function_f)(void *);
65 struct remote_function_call {
66 struct task_struct *p;
67 remote_function_f func;
72 static void remote_function(void *data)
74 struct remote_function_call *tfc = data;
75 struct task_struct *p = tfc->p;
79 if (task_cpu(p) != smp_processor_id())
83 * Now that we're on right CPU with IRQs disabled, we can test
84 * if we hit the right task without races.
87 tfc->ret = -ESRCH; /* No such (running) process */
92 tfc->ret = tfc->func(tfc->info);
96 * task_function_call - call a function on the cpu on which a task runs
97 * @p: the task to evaluate
98 * @func: the function to be called
99 * @info: the function call argument
101 * Calls the function @func when the task is currently running. This might
102 * be on the current CPU, which just calls the function directly. This will
103 * retry due to any failures in smp_call_function_single(), such as if the
104 * task_cpu() goes offline concurrently.
106 * returns @func return value or -ESRCH or -ENXIO when the process isn't running
109 task_function_call(struct task_struct *p, remote_function_f func, void *info)
111 struct remote_function_call data = {
120 ret = smp_call_function_single(task_cpu(p), remote_function,
135 * cpu_function_call - call a function on the cpu
136 * @cpu: target cpu to queue this function
137 * @func: the function to be called
138 * @info: the function call argument
140 * Calls the function @func on the remote cpu.
142 * returns: @func return value or -ENXIO when the cpu is offline
144 static int cpu_function_call(int cpu, remote_function_f func, void *info)
146 struct remote_function_call data = {
150 .ret = -ENXIO, /* No such CPU */
153 smp_call_function_single(cpu, remote_function, &data, 1);
158 static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
159 struct perf_event_context *ctx)
161 raw_spin_lock(&cpuctx->ctx.lock);
163 raw_spin_lock(&ctx->lock);
166 static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
167 struct perf_event_context *ctx)
170 raw_spin_unlock(&ctx->lock);
171 raw_spin_unlock(&cpuctx->ctx.lock);
174 #define TASK_TOMBSTONE ((void *)-1L)
176 static bool is_kernel_event(struct perf_event *event)
178 return READ_ONCE(event->owner) == TASK_TOMBSTONE;
181 static DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
183 struct perf_event_context *perf_cpu_task_ctx(void)
185 lockdep_assert_irqs_disabled();
186 return this_cpu_ptr(&perf_cpu_context)->task_ctx;
190 * On task ctx scheduling...
192 * When !ctx->nr_events a task context will not be scheduled. This means
193 * we can disable the scheduler hooks (for performance) without leaving
194 * pending task ctx state.
196 * This however results in two special cases:
198 * - removing the last event from a task ctx; this is relatively straight
199 * forward and is done in __perf_remove_from_context.
201 * - adding the first event to a task ctx; this is tricky because we cannot
202 * rely on ctx->is_active and therefore cannot use event_function_call().
203 * See perf_install_in_context().
205 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
208 typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
209 struct perf_event_context *, void *);
211 struct event_function_struct {
212 struct perf_event *event;
217 static int event_function(void *info)
219 struct event_function_struct *efs = info;
220 struct perf_event *event = efs->event;
221 struct perf_event_context *ctx = event->ctx;
222 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
223 struct perf_event_context *task_ctx = cpuctx->task_ctx;
226 lockdep_assert_irqs_disabled();
228 perf_ctx_lock(cpuctx, task_ctx);
230 * Since we do the IPI call without holding ctx->lock things can have
231 * changed, double check we hit the task we set out to hit.
234 if (ctx->task != current) {
240 * We only use event_function_call() on established contexts,
241 * and event_function() is only ever called when active (or
242 * rather, we'll have bailed in task_function_call() or the
243 * above ctx->task != current test), therefore we must have
244 * ctx->is_active here.
246 WARN_ON_ONCE(!ctx->is_active);
248 * And since we have ctx->is_active, cpuctx->task_ctx must
251 WARN_ON_ONCE(task_ctx != ctx);
253 WARN_ON_ONCE(&cpuctx->ctx != ctx);
256 efs->func(event, cpuctx, ctx, efs->data);
258 perf_ctx_unlock(cpuctx, task_ctx);
263 static void event_function_call(struct perf_event *event, event_f func, void *data)
265 struct perf_event_context *ctx = event->ctx;
266 struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
267 struct event_function_struct efs = {
273 if (!event->parent) {
275 * If this is a !child event, we must hold ctx::mutex to
276 * stabilize the event->ctx relation. See
277 * perf_event_ctx_lock().
279 lockdep_assert_held(&ctx->mutex);
283 cpu_function_call(event->cpu, event_function, &efs);
287 if (task == TASK_TOMBSTONE)
291 if (!task_function_call(task, event_function, &efs))
294 raw_spin_lock_irq(&ctx->lock);
296 * Reload the task pointer, it might have been changed by
297 * a concurrent perf_event_context_sched_out().
300 if (task == TASK_TOMBSTONE) {
301 raw_spin_unlock_irq(&ctx->lock);
304 if (ctx->is_active) {
305 raw_spin_unlock_irq(&ctx->lock);
308 func(event, NULL, ctx, data);
309 raw_spin_unlock_irq(&ctx->lock);
313 * Similar to event_function_call() + event_function(), but hard assumes IRQs
314 * are already disabled and we're on the right CPU.
316 static void event_function_local(struct perf_event *event, event_f func, void *data)
318 struct perf_event_context *ctx = event->ctx;
319 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
320 struct task_struct *task = READ_ONCE(ctx->task);
321 struct perf_event_context *task_ctx = NULL;
323 lockdep_assert_irqs_disabled();
326 if (task == TASK_TOMBSTONE)
332 perf_ctx_lock(cpuctx, task_ctx);
335 if (task == TASK_TOMBSTONE)
340 * We must be either inactive or active and the right task,
341 * otherwise we're screwed, since we cannot IPI to somewhere
344 if (ctx->is_active) {
345 if (WARN_ON_ONCE(task != current))
348 if (WARN_ON_ONCE(cpuctx->task_ctx != ctx))
352 WARN_ON_ONCE(&cpuctx->ctx != ctx);
355 func(event, cpuctx, ctx, data);
357 perf_ctx_unlock(cpuctx, task_ctx);
360 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
361 PERF_FLAG_FD_OUTPUT |\
362 PERF_FLAG_PID_CGROUP |\
363 PERF_FLAG_FD_CLOEXEC)
366 * branch priv levels that need permission checks
368 #define PERF_SAMPLE_BRANCH_PERM_PLM \
369 (PERF_SAMPLE_BRANCH_KERNEL |\
370 PERF_SAMPLE_BRANCH_HV)
373 EVENT_FLEXIBLE = 0x1,
376 /* see ctx_resched() for details */
379 EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
383 * perf_sched_events : >0 events exist
386 static void perf_sched_delayed(struct work_struct *work);
387 DEFINE_STATIC_KEY_FALSE(perf_sched_events);
388 static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
389 static DEFINE_MUTEX(perf_sched_mutex);
390 static atomic_t perf_sched_count;
392 static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
394 static atomic_t nr_mmap_events __read_mostly;
395 static atomic_t nr_comm_events __read_mostly;
396 static atomic_t nr_namespaces_events __read_mostly;
397 static atomic_t nr_task_events __read_mostly;
398 static atomic_t nr_freq_events __read_mostly;
399 static atomic_t nr_switch_events __read_mostly;
400 static atomic_t nr_ksymbol_events __read_mostly;
401 static atomic_t nr_bpf_events __read_mostly;
402 static atomic_t nr_cgroup_events __read_mostly;
403 static atomic_t nr_text_poke_events __read_mostly;
404 static atomic_t nr_build_id_events __read_mostly;
406 static LIST_HEAD(pmus);
407 static DEFINE_MUTEX(pmus_lock);
408 static struct srcu_struct pmus_srcu;
409 static cpumask_var_t perf_online_mask;
410 static struct kmem_cache *perf_event_cache;
413 * perf event paranoia level:
414 * -1 - not paranoid at all
415 * 0 - disallow raw tracepoint access for unpriv
416 * 1 - disallow cpu events for unpriv
417 * 2 - disallow kernel profiling for unpriv
419 int sysctl_perf_event_paranoid __read_mostly = 2;
421 /* Minimum for 512 kiB + 1 user control page */
422 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
425 * max perf event sample rate
427 #define DEFAULT_MAX_SAMPLE_RATE 100000
428 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
429 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
431 int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
433 static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
434 static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
436 static int perf_sample_allowed_ns __read_mostly =
437 DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
439 static void update_perf_cpu_limits(void)
441 u64 tmp = perf_sample_period_ns;
443 tmp *= sysctl_perf_cpu_time_max_percent;
444 tmp = div_u64(tmp, 100);
448 WRITE_ONCE(perf_sample_allowed_ns, tmp);
451 static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc);
453 int perf_event_max_sample_rate_handler(struct ctl_table *table, int write,
454 void *buffer, size_t *lenp, loff_t *ppos)
457 int perf_cpu = sysctl_perf_cpu_time_max_percent;
459 * If throttling is disabled don't allow the write:
461 if (write && (perf_cpu == 100 || perf_cpu == 0))
464 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
468 max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
469 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
470 update_perf_cpu_limits();
475 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
477 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
478 void *buffer, size_t *lenp, loff_t *ppos)
480 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
485 if (sysctl_perf_cpu_time_max_percent == 100 ||
486 sysctl_perf_cpu_time_max_percent == 0) {
488 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
489 WRITE_ONCE(perf_sample_allowed_ns, 0);
491 update_perf_cpu_limits();
498 * perf samples are done in some very critical code paths (NMIs).
499 * If they take too much CPU time, the system can lock up and not
500 * get any real work done. This will drop the sample rate when
501 * we detect that events are taking too long.
503 #define NR_ACCUMULATED_SAMPLES 128
504 static DEFINE_PER_CPU(u64, running_sample_length);
506 static u64 __report_avg;
507 static u64 __report_allowed;
509 static void perf_duration_warn(struct irq_work *w)
511 printk_ratelimited(KERN_INFO
512 "perf: interrupt took too long (%lld > %lld), lowering "
513 "kernel.perf_event_max_sample_rate to %d\n",
514 __report_avg, __report_allowed,
515 sysctl_perf_event_sample_rate);
518 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
520 void perf_sample_event_took(u64 sample_len_ns)
522 u64 max_len = READ_ONCE(perf_sample_allowed_ns);
530 /* Decay the counter by 1 average sample. */
531 running_len = __this_cpu_read(running_sample_length);
532 running_len -= running_len/NR_ACCUMULATED_SAMPLES;
533 running_len += sample_len_ns;
534 __this_cpu_write(running_sample_length, running_len);
537 * Note: this will be biased artifically low until we have
538 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
539 * from having to maintain a count.
541 avg_len = running_len/NR_ACCUMULATED_SAMPLES;
542 if (avg_len <= max_len)
545 __report_avg = avg_len;
546 __report_allowed = max_len;
549 * Compute a throttle threshold 25% below the current duration.
551 avg_len += avg_len / 4;
552 max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
558 WRITE_ONCE(perf_sample_allowed_ns, avg_len);
559 WRITE_ONCE(max_samples_per_tick, max);
561 sysctl_perf_event_sample_rate = max * HZ;
562 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
564 if (!irq_work_queue(&perf_duration_work)) {
565 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
566 "kernel.perf_event_max_sample_rate to %d\n",
567 __report_avg, __report_allowed,
568 sysctl_perf_event_sample_rate);
572 static atomic64_t perf_event_id;
574 static void update_context_time(struct perf_event_context *ctx);
575 static u64 perf_event_time(struct perf_event *event);
577 void __weak perf_event_print_debug(void) { }
579 static inline u64 perf_clock(void)
581 return local_clock();
584 static inline u64 perf_event_clock(struct perf_event *event)
586 return event->clock();
590 * State based event timekeeping...
592 * The basic idea is to use event->state to determine which (if any) time
593 * fields to increment with the current delta. This means we only need to
594 * update timestamps when we change state or when they are explicitly requested
597 * Event groups make things a little more complicated, but not terribly so. The
598 * rules for a group are that if the group leader is OFF the entire group is
599 * OFF, irrespecive of what the group member states are. This results in
600 * __perf_effective_state().
602 * A futher ramification is that when a group leader flips between OFF and
603 * !OFF, we need to update all group member times.
606 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
607 * need to make sure the relevant context time is updated before we try and
608 * update our timestamps.
611 static __always_inline enum perf_event_state
612 __perf_effective_state(struct perf_event *event)
614 struct perf_event *leader = event->group_leader;
616 if (leader->state <= PERF_EVENT_STATE_OFF)
617 return leader->state;
622 static __always_inline void
623 __perf_update_times(struct perf_event *event, u64 now, u64 *enabled, u64 *running)
625 enum perf_event_state state = __perf_effective_state(event);
626 u64 delta = now - event->tstamp;
628 *enabled = event->total_time_enabled;
629 if (state >= PERF_EVENT_STATE_INACTIVE)
632 *running = event->total_time_running;
633 if (state >= PERF_EVENT_STATE_ACTIVE)
637 static void perf_event_update_time(struct perf_event *event)
639 u64 now = perf_event_time(event);
641 __perf_update_times(event, now, &event->total_time_enabled,
642 &event->total_time_running);
646 static void perf_event_update_sibling_time(struct perf_event *leader)
648 struct perf_event *sibling;
650 for_each_sibling_event(sibling, leader)
651 perf_event_update_time(sibling);
655 perf_event_set_state(struct perf_event *event, enum perf_event_state state)
657 if (event->state == state)
660 perf_event_update_time(event);
662 * If a group leader gets enabled/disabled all its siblings
665 if ((event->state < 0) ^ (state < 0))
666 perf_event_update_sibling_time(event);
668 WRITE_ONCE(event->state, state);
672 * UP store-release, load-acquire
675 #define __store_release(ptr, val) \
678 WRITE_ONCE(*(ptr), (val)); \
681 #define __load_acquire(ptr) \
683 __unqual_scalar_typeof(*(ptr)) ___p = READ_ONCE(*(ptr)); \
688 static void perf_ctx_disable(struct perf_event_context *ctx, bool cgroup)
690 struct perf_event_pmu_context *pmu_ctx;
692 list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
693 if (cgroup && !pmu_ctx->nr_cgroups)
695 perf_pmu_disable(pmu_ctx->pmu);
699 static void perf_ctx_enable(struct perf_event_context *ctx, bool cgroup)
701 struct perf_event_pmu_context *pmu_ctx;
703 list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
704 if (cgroup && !pmu_ctx->nr_cgroups)
706 perf_pmu_enable(pmu_ctx->pmu);
710 static void ctx_sched_out(struct perf_event_context *ctx, enum event_type_t event_type);
711 static void ctx_sched_in(struct perf_event_context *ctx, enum event_type_t event_type);
713 #ifdef CONFIG_CGROUP_PERF
716 perf_cgroup_match(struct perf_event *event)
718 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
720 /* @event doesn't care about cgroup */
724 /* wants specific cgroup scope but @cpuctx isn't associated with any */
729 * Cgroup scoping is recursive. An event enabled for a cgroup is
730 * also enabled for all its descendant cgroups. If @cpuctx's
731 * cgroup is a descendant of @event's (the test covers identity
732 * case), it's a match.
734 return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
735 event->cgrp->css.cgroup);
738 static inline void perf_detach_cgroup(struct perf_event *event)
740 css_put(&event->cgrp->css);
744 static inline int is_cgroup_event(struct perf_event *event)
746 return event->cgrp != NULL;
749 static inline u64 perf_cgroup_event_time(struct perf_event *event)
751 struct perf_cgroup_info *t;
753 t = per_cpu_ptr(event->cgrp->info, event->cpu);
757 static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
759 struct perf_cgroup_info *t;
761 t = per_cpu_ptr(event->cgrp->info, event->cpu);
762 if (!__load_acquire(&t->active))
764 now += READ_ONCE(t->timeoffset);
768 static inline void __update_cgrp_time(struct perf_cgroup_info *info, u64 now, bool adv)
771 info->time += now - info->timestamp;
772 info->timestamp = now;
774 * see update_context_time()
776 WRITE_ONCE(info->timeoffset, info->time - info->timestamp);
779 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx, bool final)
781 struct perf_cgroup *cgrp = cpuctx->cgrp;
782 struct cgroup_subsys_state *css;
783 struct perf_cgroup_info *info;
786 u64 now = perf_clock();
788 for (css = &cgrp->css; css; css = css->parent) {
789 cgrp = container_of(css, struct perf_cgroup, css);
790 info = this_cpu_ptr(cgrp->info);
792 __update_cgrp_time(info, now, true);
794 __store_release(&info->active, 0);
799 static inline void update_cgrp_time_from_event(struct perf_event *event)
801 struct perf_cgroup_info *info;
804 * ensure we access cgroup data only when needed and
805 * when we know the cgroup is pinned (css_get)
807 if (!is_cgroup_event(event))
810 info = this_cpu_ptr(event->cgrp->info);
812 * Do not update time when cgroup is not active
815 __update_cgrp_time(info, perf_clock(), true);
819 perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
821 struct perf_event_context *ctx = &cpuctx->ctx;
822 struct perf_cgroup *cgrp = cpuctx->cgrp;
823 struct perf_cgroup_info *info;
824 struct cgroup_subsys_state *css;
827 * ctx->lock held by caller
828 * ensure we do not access cgroup data
829 * unless we have the cgroup pinned (css_get)
834 WARN_ON_ONCE(!ctx->nr_cgroups);
836 for (css = &cgrp->css; css; css = css->parent) {
837 cgrp = container_of(css, struct perf_cgroup, css);
838 info = this_cpu_ptr(cgrp->info);
839 __update_cgrp_time(info, ctx->timestamp, false);
840 __store_release(&info->active, 1);
845 * reschedule events based on the cgroup constraint of task.
847 static void perf_cgroup_switch(struct task_struct *task)
849 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
850 struct perf_cgroup *cgrp;
853 * cpuctx->cgrp is set when the first cgroup event enabled,
854 * and is cleared when the last cgroup event disabled.
856 if (READ_ONCE(cpuctx->cgrp) == NULL)
859 WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);
861 cgrp = perf_cgroup_from_task(task, NULL);
862 if (READ_ONCE(cpuctx->cgrp) == cgrp)
865 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
866 perf_ctx_disable(&cpuctx->ctx, true);
868 ctx_sched_out(&cpuctx->ctx, EVENT_ALL|EVENT_CGROUP);
870 * must not be done before ctxswout due
871 * to update_cgrp_time_from_cpuctx() in
876 * set cgrp before ctxsw in to allow
877 * perf_cgroup_set_timestamp() in ctx_sched_in()
878 * to not have to pass task around
880 ctx_sched_in(&cpuctx->ctx, EVENT_ALL|EVENT_CGROUP);
882 perf_ctx_enable(&cpuctx->ctx, true);
883 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
886 static int perf_cgroup_ensure_storage(struct perf_event *event,
887 struct cgroup_subsys_state *css)
889 struct perf_cpu_context *cpuctx;
890 struct perf_event **storage;
891 int cpu, heap_size, ret = 0;
894 * Allow storage to have sufficent space for an iterator for each
895 * possibly nested cgroup plus an iterator for events with no cgroup.
897 for (heap_size = 1; css; css = css->parent)
900 for_each_possible_cpu(cpu) {
901 cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
902 if (heap_size <= cpuctx->heap_size)
905 storage = kmalloc_node(heap_size * sizeof(struct perf_event *),
906 GFP_KERNEL, cpu_to_node(cpu));
912 raw_spin_lock_irq(&cpuctx->ctx.lock);
913 if (cpuctx->heap_size < heap_size) {
914 swap(cpuctx->heap, storage);
915 if (storage == cpuctx->heap_default)
917 cpuctx->heap_size = heap_size;
919 raw_spin_unlock_irq(&cpuctx->ctx.lock);
927 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
928 struct perf_event_attr *attr,
929 struct perf_event *group_leader)
931 struct perf_cgroup *cgrp;
932 struct cgroup_subsys_state *css;
933 struct fd f = fdget(fd);
939 css = css_tryget_online_from_dir(f.file->f_path.dentry,
940 &perf_event_cgrp_subsys);
946 ret = perf_cgroup_ensure_storage(event, css);
950 cgrp = container_of(css, struct perf_cgroup, css);
954 * all events in a group must monitor
955 * the same cgroup because a task belongs
956 * to only one perf cgroup at a time
958 if (group_leader && group_leader->cgrp != cgrp) {
959 perf_detach_cgroup(event);
968 perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
970 struct perf_cpu_context *cpuctx;
972 if (!is_cgroup_event(event))
975 event->pmu_ctx->nr_cgroups++;
978 * Because cgroup events are always per-cpu events,
979 * @ctx == &cpuctx->ctx.
981 cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
983 if (ctx->nr_cgroups++)
986 cpuctx->cgrp = perf_cgroup_from_task(current, ctx);
990 perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
992 struct perf_cpu_context *cpuctx;
994 if (!is_cgroup_event(event))
997 event->pmu_ctx->nr_cgroups--;
1000 * Because cgroup events are always per-cpu events,
1001 * @ctx == &cpuctx->ctx.
1003 cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
1005 if (--ctx->nr_cgroups)
1008 cpuctx->cgrp = NULL;
1011 #else /* !CONFIG_CGROUP_PERF */
1014 perf_cgroup_match(struct perf_event *event)
1019 static inline void perf_detach_cgroup(struct perf_event *event)
1022 static inline int is_cgroup_event(struct perf_event *event)
1027 static inline void update_cgrp_time_from_event(struct perf_event *event)
1031 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx,
1036 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
1037 struct perf_event_attr *attr,
1038 struct perf_event *group_leader)
1044 perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
1048 static inline u64 perf_cgroup_event_time(struct perf_event *event)
1053 static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
1059 perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
1064 perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
1068 static void perf_cgroup_switch(struct task_struct *task)
1074 * set default to be dependent on timer tick just
1075 * like original code
1077 #define PERF_CPU_HRTIMER (1000 / HZ)
1079 * function must be called with interrupts disabled
1081 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
1083 struct perf_cpu_pmu_context *cpc;
1086 lockdep_assert_irqs_disabled();
1088 cpc = container_of(hr, struct perf_cpu_pmu_context, hrtimer);
1089 rotations = perf_rotate_context(cpc);
1091 raw_spin_lock(&cpc->hrtimer_lock);
1093 hrtimer_forward_now(hr, cpc->hrtimer_interval);
1095 cpc->hrtimer_active = 0;
1096 raw_spin_unlock(&cpc->hrtimer_lock);
1098 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
1101 static void __perf_mux_hrtimer_init(struct perf_cpu_pmu_context *cpc, int cpu)
1103 struct hrtimer *timer = &cpc->hrtimer;
1104 struct pmu *pmu = cpc->epc.pmu;
1108 * check default is sane, if not set then force to
1109 * default interval (1/tick)
1111 interval = pmu->hrtimer_interval_ms;
1113 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
1115 cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
1117 raw_spin_lock_init(&cpc->hrtimer_lock);
1118 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
1119 timer->function = perf_mux_hrtimer_handler;
1122 static int perf_mux_hrtimer_restart(struct perf_cpu_pmu_context *cpc)
1124 struct hrtimer *timer = &cpc->hrtimer;
1125 unsigned long flags;
1127 raw_spin_lock_irqsave(&cpc->hrtimer_lock, flags);
1128 if (!cpc->hrtimer_active) {
1129 cpc->hrtimer_active = 1;
1130 hrtimer_forward_now(timer, cpc->hrtimer_interval);
1131 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
1133 raw_spin_unlock_irqrestore(&cpc->hrtimer_lock, flags);
1138 static int perf_mux_hrtimer_restart_ipi(void *arg)
1140 return perf_mux_hrtimer_restart(arg);
1143 void perf_pmu_disable(struct pmu *pmu)
1145 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1147 pmu->pmu_disable(pmu);
1150 void perf_pmu_enable(struct pmu *pmu)
1152 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1154 pmu->pmu_enable(pmu);
1157 static void perf_assert_pmu_disabled(struct pmu *pmu)
1159 WARN_ON_ONCE(*this_cpu_ptr(pmu->pmu_disable_count) == 0);
1162 static void get_ctx(struct perf_event_context *ctx)
1164 refcount_inc(&ctx->refcount);
1167 static void *alloc_task_ctx_data(struct pmu *pmu)
1169 if (pmu->task_ctx_cache)
1170 return kmem_cache_zalloc(pmu->task_ctx_cache, GFP_KERNEL);
1175 static void free_task_ctx_data(struct pmu *pmu, void *task_ctx_data)
1177 if (pmu->task_ctx_cache && task_ctx_data)
1178 kmem_cache_free(pmu->task_ctx_cache, task_ctx_data);
1181 static void free_ctx(struct rcu_head *head)
1183 struct perf_event_context *ctx;
1185 ctx = container_of(head, struct perf_event_context, rcu_head);
1189 static void put_ctx(struct perf_event_context *ctx)
1191 if (refcount_dec_and_test(&ctx->refcount)) {
1192 if (ctx->parent_ctx)
1193 put_ctx(ctx->parent_ctx);
1194 if (ctx->task && ctx->task != TASK_TOMBSTONE)
1195 put_task_struct(ctx->task);
1196 call_rcu(&ctx->rcu_head, free_ctx);
1201 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1202 * perf_pmu_migrate_context() we need some magic.
1204 * Those places that change perf_event::ctx will hold both
1205 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1207 * Lock ordering is by mutex address. There are two other sites where
1208 * perf_event_context::mutex nests and those are:
1210 * - perf_event_exit_task_context() [ child , 0 ]
1211 * perf_event_exit_event()
1212 * put_event() [ parent, 1 ]
1214 * - perf_event_init_context() [ parent, 0 ]
1215 * inherit_task_group()
1218 * perf_event_alloc()
1220 * perf_try_init_event() [ child , 1 ]
1222 * While it appears there is an obvious deadlock here -- the parent and child
1223 * nesting levels are inverted between the two. This is in fact safe because
1224 * life-time rules separate them. That is an exiting task cannot fork, and a
1225 * spawning task cannot (yet) exit.
1227 * But remember that these are parent<->child context relations, and
1228 * migration does not affect children, therefore these two orderings should not
1231 * The change in perf_event::ctx does not affect children (as claimed above)
1232 * because the sys_perf_event_open() case will install a new event and break
1233 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1234 * concerned with cpuctx and that doesn't have children.
1236 * The places that change perf_event::ctx will issue:
1238 * perf_remove_from_context();
1239 * synchronize_rcu();
1240 * perf_install_in_context();
1242 * to affect the change. The remove_from_context() + synchronize_rcu() should
1243 * quiesce the event, after which we can install it in the new location. This
1244 * means that only external vectors (perf_fops, prctl) can perturb the event
1245 * while in transit. Therefore all such accessors should also acquire
1246 * perf_event_context::mutex to serialize against this.
1248 * However; because event->ctx can change while we're waiting to acquire
1249 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1254 * task_struct::perf_event_mutex
1255 * perf_event_context::mutex
1256 * perf_event::child_mutex;
1257 * perf_event_context::lock
1258 * perf_event::mmap_mutex
1260 * perf_addr_filters_head::lock
1264 * cpuctx->mutex / perf_event_context::mutex
1266 static struct perf_event_context *
1267 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
1269 struct perf_event_context *ctx;
1273 ctx = READ_ONCE(event->ctx);
1274 if (!refcount_inc_not_zero(&ctx->refcount)) {
1280 mutex_lock_nested(&ctx->mutex, nesting);
1281 if (event->ctx != ctx) {
1282 mutex_unlock(&ctx->mutex);
1290 static inline struct perf_event_context *
1291 perf_event_ctx_lock(struct perf_event *event)
1293 return perf_event_ctx_lock_nested(event, 0);
1296 static void perf_event_ctx_unlock(struct perf_event *event,
1297 struct perf_event_context *ctx)
1299 mutex_unlock(&ctx->mutex);
1304 * This must be done under the ctx->lock, such as to serialize against
1305 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1306 * calling scheduler related locks and ctx->lock nests inside those.
1308 static __must_check struct perf_event_context *
1309 unclone_ctx(struct perf_event_context *ctx)
1311 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1313 lockdep_assert_held(&ctx->lock);
1316 ctx->parent_ctx = NULL;
1322 static u32 perf_event_pid_type(struct perf_event *event, struct task_struct *p,
1327 * only top level events have the pid namespace they were created in
1330 event = event->parent;
1332 nr = __task_pid_nr_ns(p, type, event->ns);
1333 /* avoid -1 if it is idle thread or runs in another ns */
1334 if (!nr && !pid_alive(p))
1339 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1341 return perf_event_pid_type(event, p, PIDTYPE_TGID);
1344 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1346 return perf_event_pid_type(event, p, PIDTYPE_PID);
1350 * If we inherit events we want to return the parent event id
1353 static u64 primary_event_id(struct perf_event *event)
1358 id = event->parent->id;
1364 * Get the perf_event_context for a task and lock it.
1366 * This has to cope with the fact that until it is locked,
1367 * the context could get moved to another task.
1369 static struct perf_event_context *
1370 perf_lock_task_context(struct task_struct *task, unsigned long *flags)
1372 struct perf_event_context *ctx;
1376 * One of the few rules of preemptible RCU is that one cannot do
1377 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1378 * part of the read side critical section was irqs-enabled -- see
1379 * rcu_read_unlock_special().
1381 * Since ctx->lock nests under rq->lock we must ensure the entire read
1382 * side critical section has interrupts disabled.
1384 local_irq_save(*flags);
1386 ctx = rcu_dereference(task->perf_event_ctxp);
1389 * If this context is a clone of another, it might
1390 * get swapped for another underneath us by
1391 * perf_event_task_sched_out, though the
1392 * rcu_read_lock() protects us from any context
1393 * getting freed. Lock the context and check if it
1394 * got swapped before we could get the lock, and retry
1395 * if so. If we locked the right context, then it
1396 * can't get swapped on us any more.
1398 raw_spin_lock(&ctx->lock);
1399 if (ctx != rcu_dereference(task->perf_event_ctxp)) {
1400 raw_spin_unlock(&ctx->lock);
1402 local_irq_restore(*flags);
1406 if (ctx->task == TASK_TOMBSTONE ||
1407 !refcount_inc_not_zero(&ctx->refcount)) {
1408 raw_spin_unlock(&ctx->lock);
1411 WARN_ON_ONCE(ctx->task != task);
1416 local_irq_restore(*flags);
1421 * Get the context for a task and increment its pin_count so it
1422 * can't get swapped to another task. This also increments its
1423 * reference count so that the context can't get freed.
1425 static struct perf_event_context *
1426 perf_pin_task_context(struct task_struct *task)
1428 struct perf_event_context *ctx;
1429 unsigned long flags;
1431 ctx = perf_lock_task_context(task, &flags);
1434 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1439 static void perf_unpin_context(struct perf_event_context *ctx)
1441 unsigned long flags;
1443 raw_spin_lock_irqsave(&ctx->lock, flags);
1445 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1449 * Update the record of the current time in a context.
1451 static void __update_context_time(struct perf_event_context *ctx, bool adv)
1453 u64 now = perf_clock();
1455 lockdep_assert_held(&ctx->lock);
1458 ctx->time += now - ctx->timestamp;
1459 ctx->timestamp = now;
1462 * The above: time' = time + (now - timestamp), can be re-arranged
1463 * into: time` = now + (time - timestamp), which gives a single value
1464 * offset to compute future time without locks on.
1466 * See perf_event_time_now(), which can be used from NMI context where
1467 * it's (obviously) not possible to acquire ctx->lock in order to read
1468 * both the above values in a consistent manner.
1470 WRITE_ONCE(ctx->timeoffset, ctx->time - ctx->timestamp);
1473 static void update_context_time(struct perf_event_context *ctx)
1475 __update_context_time(ctx, true);
1478 static u64 perf_event_time(struct perf_event *event)
1480 struct perf_event_context *ctx = event->ctx;
1485 if (is_cgroup_event(event))
1486 return perf_cgroup_event_time(event);
1491 static u64 perf_event_time_now(struct perf_event *event, u64 now)
1493 struct perf_event_context *ctx = event->ctx;
1498 if (is_cgroup_event(event))
1499 return perf_cgroup_event_time_now(event, now);
1501 if (!(__load_acquire(&ctx->is_active) & EVENT_TIME))
1504 now += READ_ONCE(ctx->timeoffset);
1508 static enum event_type_t get_event_type(struct perf_event *event)
1510 struct perf_event_context *ctx = event->ctx;
1511 enum event_type_t event_type;
1513 lockdep_assert_held(&ctx->lock);
1516 * It's 'group type', really, because if our group leader is
1517 * pinned, so are we.
1519 if (event->group_leader != event)
1520 event = event->group_leader;
1522 event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE;
1524 event_type |= EVENT_CPU;
1530 * Helper function to initialize event group nodes.
1532 static void init_event_group(struct perf_event *event)
1534 RB_CLEAR_NODE(&event->group_node);
1535 event->group_index = 0;
1539 * Extract pinned or flexible groups from the context
1540 * based on event attrs bits.
1542 static struct perf_event_groups *
1543 get_event_groups(struct perf_event *event, struct perf_event_context *ctx)
1545 if (event->attr.pinned)
1546 return &ctx->pinned_groups;
1548 return &ctx->flexible_groups;
1552 * Helper function to initializes perf_event_group trees.
1554 static void perf_event_groups_init(struct perf_event_groups *groups)
1556 groups->tree = RB_ROOT;
1560 static inline struct cgroup *event_cgroup(const struct perf_event *event)
1562 struct cgroup *cgroup = NULL;
1564 #ifdef CONFIG_CGROUP_PERF
1566 cgroup = event->cgrp->css.cgroup;
1573 * Compare function for event groups;
1575 * Implements complex key that first sorts by CPU and then by virtual index
1576 * which provides ordering when rotating groups for the same CPU.
1578 static __always_inline int
1579 perf_event_groups_cmp(const int left_cpu, const struct pmu *left_pmu,
1580 const struct cgroup *left_cgroup, const u64 left_group_index,
1581 const struct perf_event *right)
1583 if (left_cpu < right->cpu)
1585 if (left_cpu > right->cpu)
1589 if (left_pmu < right->pmu_ctx->pmu)
1591 if (left_pmu > right->pmu_ctx->pmu)
1595 #ifdef CONFIG_CGROUP_PERF
1597 const struct cgroup *right_cgroup = event_cgroup(right);
1599 if (left_cgroup != right_cgroup) {
1602 * Left has no cgroup but right does, no
1603 * cgroups come first.
1607 if (!right_cgroup) {
1609 * Right has no cgroup but left does, no
1610 * cgroups come first.
1614 /* Two dissimilar cgroups, order by id. */
1615 if (cgroup_id(left_cgroup) < cgroup_id(right_cgroup))
1623 if (left_group_index < right->group_index)
1625 if (left_group_index > right->group_index)
1631 #define __node_2_pe(node) \
1632 rb_entry((node), struct perf_event, group_node)
1634 static inline bool __group_less(struct rb_node *a, const struct rb_node *b)
1636 struct perf_event *e = __node_2_pe(a);
1637 return perf_event_groups_cmp(e->cpu, e->pmu_ctx->pmu, event_cgroup(e),
1638 e->group_index, __node_2_pe(b)) < 0;
1641 struct __group_key {
1644 struct cgroup *cgroup;
1647 static inline int __group_cmp(const void *key, const struct rb_node *node)
1649 const struct __group_key *a = key;
1650 const struct perf_event *b = __node_2_pe(node);
1652 /* partial/subtree match: @cpu, @pmu, @cgroup; ignore: @group_index */
1653 return perf_event_groups_cmp(a->cpu, a->pmu, a->cgroup, b->group_index, b);
1657 __group_cmp_ignore_cgroup(const void *key, const struct rb_node *node)
1659 const struct __group_key *a = key;
1660 const struct perf_event *b = __node_2_pe(node);
1662 /* partial/subtree match: @cpu, @pmu, ignore: @cgroup, @group_index */
1663 return perf_event_groups_cmp(a->cpu, a->pmu, event_cgroup(b),
1668 * Insert @event into @groups' tree; using
1669 * {@event->cpu, @event->pmu_ctx->pmu, event_cgroup(@event), ++@groups->index}
1670 * as key. This places it last inside the {cpu,pmu,cgroup} subtree.
1673 perf_event_groups_insert(struct perf_event_groups *groups,
1674 struct perf_event *event)
1676 event->group_index = ++groups->index;
1678 rb_add(&event->group_node, &groups->tree, __group_less);
1682 * Helper function to insert event into the pinned or flexible groups.
1685 add_event_to_groups(struct perf_event *event, struct perf_event_context *ctx)
1687 struct perf_event_groups *groups;
1689 groups = get_event_groups(event, ctx);
1690 perf_event_groups_insert(groups, event);
1694 * Delete a group from a tree.
1697 perf_event_groups_delete(struct perf_event_groups *groups,
1698 struct perf_event *event)
1700 WARN_ON_ONCE(RB_EMPTY_NODE(&event->group_node) ||
1701 RB_EMPTY_ROOT(&groups->tree));
1703 rb_erase(&event->group_node, &groups->tree);
1704 init_event_group(event);
1708 * Helper function to delete event from its groups.
1711 del_event_from_groups(struct perf_event *event, struct perf_event_context *ctx)
1713 struct perf_event_groups *groups;
1715 groups = get_event_groups(event, ctx);
1716 perf_event_groups_delete(groups, event);
1720 * Get the leftmost event in the {cpu,pmu,cgroup} subtree.
1722 static struct perf_event *
1723 perf_event_groups_first(struct perf_event_groups *groups, int cpu,
1724 struct pmu *pmu, struct cgroup *cgrp)
1726 struct __group_key key = {
1731 struct rb_node *node;
1733 node = rb_find_first(&key, &groups->tree, __group_cmp);
1735 return __node_2_pe(node);
1740 static struct perf_event *
1741 perf_event_groups_next(struct perf_event *event, struct pmu *pmu)
1743 struct __group_key key = {
1746 .cgroup = event_cgroup(event),
1748 struct rb_node *next;
1750 next = rb_next_match(&key, &event->group_node, __group_cmp);
1752 return __node_2_pe(next);
1757 #define perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu) \
1758 for (event = perf_event_groups_first(groups, cpu, pmu, NULL); \
1759 event; event = perf_event_groups_next(event, pmu))
1762 * Iterate through the whole groups tree.
1764 #define perf_event_groups_for_each(event, groups) \
1765 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1766 typeof(*event), group_node); event; \
1767 event = rb_entry_safe(rb_next(&event->group_node), \
1768 typeof(*event), group_node))
1771 * Add an event from the lists for its context.
1772 * Must be called with ctx->mutex and ctx->lock held.
1775 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1777 lockdep_assert_held(&ctx->lock);
1779 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1780 event->attach_state |= PERF_ATTACH_CONTEXT;
1782 event->tstamp = perf_event_time(event);
1785 * If we're a stand alone event or group leader, we go to the context
1786 * list, group events are kept attached to the group so that
1787 * perf_group_detach can, at all times, locate all siblings.
1789 if (event->group_leader == event) {
1790 event->group_caps = event->event_caps;
1791 add_event_to_groups(event, ctx);
1794 list_add_rcu(&event->event_entry, &ctx->event_list);
1796 if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
1798 if (event->attr.inherit_stat)
1801 if (event->state > PERF_EVENT_STATE_OFF)
1802 perf_cgroup_event_enable(event, ctx);
1805 event->pmu_ctx->nr_events++;
1809 * Initialize event state based on the perf_event_attr::disabled.
1811 static inline void perf_event__state_init(struct perf_event *event)
1813 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1814 PERF_EVENT_STATE_INACTIVE;
1817 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1819 int entry = sizeof(u64); /* value */
1823 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1824 size += sizeof(u64);
1826 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1827 size += sizeof(u64);
1829 if (event->attr.read_format & PERF_FORMAT_ID)
1830 entry += sizeof(u64);
1832 if (event->attr.read_format & PERF_FORMAT_LOST)
1833 entry += sizeof(u64);
1835 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1837 size += sizeof(u64);
1841 event->read_size = size;
1844 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1846 struct perf_sample_data *data;
1849 if (sample_type & PERF_SAMPLE_IP)
1850 size += sizeof(data->ip);
1852 if (sample_type & PERF_SAMPLE_ADDR)
1853 size += sizeof(data->addr);
1855 if (sample_type & PERF_SAMPLE_PERIOD)
1856 size += sizeof(data->period);
1858 if (sample_type & PERF_SAMPLE_WEIGHT_TYPE)
1859 size += sizeof(data->weight.full);
1861 if (sample_type & PERF_SAMPLE_READ)
1862 size += event->read_size;
1864 if (sample_type & PERF_SAMPLE_DATA_SRC)
1865 size += sizeof(data->data_src.val);
1867 if (sample_type & PERF_SAMPLE_TRANSACTION)
1868 size += sizeof(data->txn);
1870 if (sample_type & PERF_SAMPLE_PHYS_ADDR)
1871 size += sizeof(data->phys_addr);
1873 if (sample_type & PERF_SAMPLE_CGROUP)
1874 size += sizeof(data->cgroup);
1876 if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
1877 size += sizeof(data->data_page_size);
1879 if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
1880 size += sizeof(data->code_page_size);
1882 event->header_size = size;
1886 * Called at perf_event creation and when events are attached/detached from a
1889 static void perf_event__header_size(struct perf_event *event)
1891 __perf_event_read_size(event,
1892 event->group_leader->nr_siblings);
1893 __perf_event_header_size(event, event->attr.sample_type);
1896 static void perf_event__id_header_size(struct perf_event *event)
1898 struct perf_sample_data *data;
1899 u64 sample_type = event->attr.sample_type;
1902 if (sample_type & PERF_SAMPLE_TID)
1903 size += sizeof(data->tid_entry);
1905 if (sample_type & PERF_SAMPLE_TIME)
1906 size += sizeof(data->time);
1908 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1909 size += sizeof(data->id);
1911 if (sample_type & PERF_SAMPLE_ID)
1912 size += sizeof(data->id);
1914 if (sample_type & PERF_SAMPLE_STREAM_ID)
1915 size += sizeof(data->stream_id);
1917 if (sample_type & PERF_SAMPLE_CPU)
1918 size += sizeof(data->cpu_entry);
1920 event->id_header_size = size;
1923 static bool perf_event_validate_size(struct perf_event *event)
1926 * The values computed here will be over-written when we actually
1929 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1930 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1931 perf_event__id_header_size(event);
1934 * Sum the lot; should not exceed the 64k limit we have on records.
1935 * Conservative limit to allow for callchains and other variable fields.
1937 if (event->read_size + event->header_size +
1938 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1944 static void perf_group_attach(struct perf_event *event)
1946 struct perf_event *group_leader = event->group_leader, *pos;
1948 lockdep_assert_held(&event->ctx->lock);
1951 * We can have double attach due to group movement (move_group) in
1952 * perf_event_open().
1954 if (event->attach_state & PERF_ATTACH_GROUP)
1957 event->attach_state |= PERF_ATTACH_GROUP;
1959 if (group_leader == event)
1962 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1964 group_leader->group_caps &= event->event_caps;
1966 list_add_tail(&event->sibling_list, &group_leader->sibling_list);
1967 group_leader->nr_siblings++;
1968 group_leader->group_generation++;
1970 perf_event__header_size(group_leader);
1972 for_each_sibling_event(pos, group_leader)
1973 perf_event__header_size(pos);
1977 * Remove an event from the lists for its context.
1978 * Must be called with ctx->mutex and ctx->lock held.
1981 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1983 WARN_ON_ONCE(event->ctx != ctx);
1984 lockdep_assert_held(&ctx->lock);
1987 * We can have double detach due to exit/hot-unplug + close.
1989 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1992 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1995 if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
1997 if (event->attr.inherit_stat)
2000 list_del_rcu(&event->event_entry);
2002 if (event->group_leader == event)
2003 del_event_from_groups(event, ctx);
2006 * If event was in error state, then keep it
2007 * that way, otherwise bogus counts will be
2008 * returned on read(). The only way to get out
2009 * of error state is by explicit re-enabling
2012 if (event->state > PERF_EVENT_STATE_OFF) {
2013 perf_cgroup_event_disable(event, ctx);
2014 perf_event_set_state(event, PERF_EVENT_STATE_OFF);
2018 event->pmu_ctx->nr_events--;
2022 perf_aux_output_match(struct perf_event *event, struct perf_event *aux_event)
2024 if (!has_aux(aux_event))
2027 if (!event->pmu->aux_output_match)
2030 return event->pmu->aux_output_match(aux_event);
2033 static void put_event(struct perf_event *event);
2034 static void event_sched_out(struct perf_event *event,
2035 struct perf_event_context *ctx);
2037 static void perf_put_aux_event(struct perf_event *event)
2039 struct perf_event_context *ctx = event->ctx;
2040 struct perf_event *iter;
2043 * If event uses aux_event tear down the link
2045 if (event->aux_event) {
2046 iter = event->aux_event;
2047 event->aux_event = NULL;
2053 * If the event is an aux_event, tear down all links to
2054 * it from other events.
2056 for_each_sibling_event(iter, event->group_leader) {
2057 if (iter->aux_event != event)
2060 iter->aux_event = NULL;
2064 * If it's ACTIVE, schedule it out and put it into ERROR
2065 * state so that we don't try to schedule it again. Note
2066 * that perf_event_enable() will clear the ERROR status.
2068 event_sched_out(iter, ctx);
2069 perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
2073 static bool perf_need_aux_event(struct perf_event *event)
2075 return !!event->attr.aux_output || !!event->attr.aux_sample_size;
2078 static int perf_get_aux_event(struct perf_event *event,
2079 struct perf_event *group_leader)
2082 * Our group leader must be an aux event if we want to be
2083 * an aux_output. This way, the aux event will precede its
2084 * aux_output events in the group, and therefore will always
2091 * aux_output and aux_sample_size are mutually exclusive.
2093 if (event->attr.aux_output && event->attr.aux_sample_size)
2096 if (event->attr.aux_output &&
2097 !perf_aux_output_match(event, group_leader))
2100 if (event->attr.aux_sample_size && !group_leader->pmu->snapshot_aux)
2103 if (!atomic_long_inc_not_zero(&group_leader->refcount))
2107 * Link aux_outputs to their aux event; this is undone in
2108 * perf_group_detach() by perf_put_aux_event(). When the
2109 * group in torn down, the aux_output events loose their
2110 * link to the aux_event and can't schedule any more.
2112 event->aux_event = group_leader;
2117 static inline struct list_head *get_event_list(struct perf_event *event)
2119 return event->attr.pinned ? &event->pmu_ctx->pinned_active :
2120 &event->pmu_ctx->flexible_active;
2124 * Events that have PERF_EV_CAP_SIBLING require being part of a group and
2125 * cannot exist on their own, schedule them out and move them into the ERROR
2126 * state. Also see _perf_event_enable(), it will not be able to recover
2129 static inline void perf_remove_sibling_event(struct perf_event *event)
2131 event_sched_out(event, event->ctx);
2132 perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
2135 static void perf_group_detach(struct perf_event *event)
2137 struct perf_event *leader = event->group_leader;
2138 struct perf_event *sibling, *tmp;
2139 struct perf_event_context *ctx = event->ctx;
2141 lockdep_assert_held(&ctx->lock);
2144 * We can have double detach due to exit/hot-unplug + close.
2146 if (!(event->attach_state & PERF_ATTACH_GROUP))
2149 event->attach_state &= ~PERF_ATTACH_GROUP;
2151 perf_put_aux_event(event);
2154 * If this is a sibling, remove it from its group.
2156 if (leader != event) {
2157 list_del_init(&event->sibling_list);
2158 event->group_leader->nr_siblings--;
2159 event->group_leader->group_generation++;
2164 * If this was a group event with sibling events then
2165 * upgrade the siblings to singleton events by adding them
2166 * to whatever list we are on.
2168 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, sibling_list) {
2170 if (sibling->event_caps & PERF_EV_CAP_SIBLING)
2171 perf_remove_sibling_event(sibling);
2173 sibling->group_leader = sibling;
2174 list_del_init(&sibling->sibling_list);
2176 /* Inherit group flags from the previous leader */
2177 sibling->group_caps = event->group_caps;
2179 if (sibling->attach_state & PERF_ATTACH_CONTEXT) {
2180 add_event_to_groups(sibling, event->ctx);
2182 if (sibling->state == PERF_EVENT_STATE_ACTIVE)
2183 list_add_tail(&sibling->active_list, get_event_list(sibling));
2186 WARN_ON_ONCE(sibling->ctx != event->ctx);
2190 for_each_sibling_event(tmp, leader)
2191 perf_event__header_size(tmp);
2193 perf_event__header_size(leader);
2196 static void sync_child_event(struct perf_event *child_event);
2198 static void perf_child_detach(struct perf_event *event)
2200 struct perf_event *parent_event = event->parent;
2202 if (!(event->attach_state & PERF_ATTACH_CHILD))
2205 event->attach_state &= ~PERF_ATTACH_CHILD;
2207 if (WARN_ON_ONCE(!parent_event))
2210 lockdep_assert_held(&parent_event->child_mutex);
2212 sync_child_event(event);
2213 list_del_init(&event->child_list);
2216 static bool is_orphaned_event(struct perf_event *event)
2218 return event->state == PERF_EVENT_STATE_DEAD;
2222 event_filter_match(struct perf_event *event)
2224 return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
2225 perf_cgroup_match(event);
2229 event_sched_out(struct perf_event *event, struct perf_event_context *ctx)
2231 struct perf_event_pmu_context *epc = event->pmu_ctx;
2232 struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
2233 enum perf_event_state state = PERF_EVENT_STATE_INACTIVE;
2235 // XXX cpc serialization, probably per-cpu IRQ disabled
2237 WARN_ON_ONCE(event->ctx != ctx);
2238 lockdep_assert_held(&ctx->lock);
2240 if (event->state != PERF_EVENT_STATE_ACTIVE)
2244 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2245 * we can schedule events _OUT_ individually through things like
2246 * __perf_remove_from_context().
2248 list_del_init(&event->active_list);
2250 perf_pmu_disable(event->pmu);
2252 event->pmu->del(event, 0);
2255 if (event->pending_disable) {
2256 event->pending_disable = 0;
2257 perf_cgroup_event_disable(event, ctx);
2258 state = PERF_EVENT_STATE_OFF;
2261 if (event->pending_sigtrap) {
2264 event->pending_sigtrap = 0;
2265 if (state != PERF_EVENT_STATE_OFF &&
2266 !event->pending_work) {
2267 event->pending_work = 1;
2269 WARN_ON_ONCE(!atomic_long_inc_not_zero(&event->refcount));
2270 task_work_add(current, &event->pending_task, TWA_RESUME);
2273 local_dec(&event->ctx->nr_pending);
2276 perf_event_set_state(event, state);
2278 if (!is_software_event(event))
2279 cpc->active_oncpu--;
2280 if (event->attr.freq && event->attr.sample_freq)
2282 if (event->attr.exclusive || !cpc->active_oncpu)
2285 perf_pmu_enable(event->pmu);
2289 group_sched_out(struct perf_event *group_event, struct perf_event_context *ctx)
2291 struct perf_event *event;
2293 if (group_event->state != PERF_EVENT_STATE_ACTIVE)
2296 perf_assert_pmu_disabled(group_event->pmu_ctx->pmu);
2298 event_sched_out(group_event, ctx);
2301 * Schedule out siblings (if any):
2303 for_each_sibling_event(event, group_event)
2304 event_sched_out(event, ctx);
2307 #define DETACH_GROUP 0x01UL
2308 #define DETACH_CHILD 0x02UL
2309 #define DETACH_DEAD 0x04UL
2312 * Cross CPU call to remove a performance event
2314 * We disable the event on the hardware level first. After that we
2315 * remove it from the context list.
2318 __perf_remove_from_context(struct perf_event *event,
2319 struct perf_cpu_context *cpuctx,
2320 struct perf_event_context *ctx,
2323 struct perf_event_pmu_context *pmu_ctx = event->pmu_ctx;
2324 unsigned long flags = (unsigned long)info;
2326 if (ctx->is_active & EVENT_TIME) {
2327 update_context_time(ctx);
2328 update_cgrp_time_from_cpuctx(cpuctx, false);
2332 * Ensure event_sched_out() switches to OFF, at the very least
2333 * this avoids raising perf_pending_task() at this time.
2335 if (flags & DETACH_DEAD)
2336 event->pending_disable = 1;
2337 event_sched_out(event, ctx);
2338 if (flags & DETACH_GROUP)
2339 perf_group_detach(event);
2340 if (flags & DETACH_CHILD)
2341 perf_child_detach(event);
2342 list_del_event(event, ctx);
2343 if (flags & DETACH_DEAD)
2344 event->state = PERF_EVENT_STATE_DEAD;
2346 if (!pmu_ctx->nr_events) {
2347 pmu_ctx->rotate_necessary = 0;
2349 if (ctx->task && ctx->is_active) {
2350 struct perf_cpu_pmu_context *cpc;
2352 cpc = this_cpu_ptr(pmu_ctx->pmu->cpu_pmu_context);
2353 WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
2354 cpc->task_epc = NULL;
2358 if (!ctx->nr_events && ctx->is_active) {
2359 if (ctx == &cpuctx->ctx)
2360 update_cgrp_time_from_cpuctx(cpuctx, true);
2364 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
2365 cpuctx->task_ctx = NULL;
2371 * Remove the event from a task's (or a CPU's) list of events.
2373 * If event->ctx is a cloned context, callers must make sure that
2374 * every task struct that event->ctx->task could possibly point to
2375 * remains valid. This is OK when called from perf_release since
2376 * that only calls us on the top-level context, which can't be a clone.
2377 * When called from perf_event_exit_task, it's OK because the
2378 * context has been detached from its task.
2380 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
2382 struct perf_event_context *ctx = event->ctx;
2384 lockdep_assert_held(&ctx->mutex);
2387 * Because of perf_event_exit_task(), perf_remove_from_context() ought
2388 * to work in the face of TASK_TOMBSTONE, unlike every other
2389 * event_function_call() user.
2391 raw_spin_lock_irq(&ctx->lock);
2392 if (!ctx->is_active) {
2393 __perf_remove_from_context(event, this_cpu_ptr(&perf_cpu_context),
2394 ctx, (void *)flags);
2395 raw_spin_unlock_irq(&ctx->lock);
2398 raw_spin_unlock_irq(&ctx->lock);
2400 event_function_call(event, __perf_remove_from_context, (void *)flags);
2404 * Cross CPU call to disable a performance event
2406 static void __perf_event_disable(struct perf_event *event,
2407 struct perf_cpu_context *cpuctx,
2408 struct perf_event_context *ctx,
2411 if (event->state < PERF_EVENT_STATE_INACTIVE)
2414 if (ctx->is_active & EVENT_TIME) {
2415 update_context_time(ctx);
2416 update_cgrp_time_from_event(event);
2419 perf_pmu_disable(event->pmu_ctx->pmu);
2421 if (event == event->group_leader)
2422 group_sched_out(event, ctx);
2424 event_sched_out(event, ctx);
2426 perf_event_set_state(event, PERF_EVENT_STATE_OFF);
2427 perf_cgroup_event_disable(event, ctx);
2429 perf_pmu_enable(event->pmu_ctx->pmu);
2435 * If event->ctx is a cloned context, callers must make sure that
2436 * every task struct that event->ctx->task could possibly point to
2437 * remains valid. This condition is satisfied when called through
2438 * perf_event_for_each_child or perf_event_for_each because they
2439 * hold the top-level event's child_mutex, so any descendant that
2440 * goes to exit will block in perf_event_exit_event().
2442 * When called from perf_pending_irq it's OK because event->ctx
2443 * is the current context on this CPU and preemption is disabled,
2444 * hence we can't get into perf_event_task_sched_out for this context.
2446 static void _perf_event_disable(struct perf_event *event)
2448 struct perf_event_context *ctx = event->ctx;
2450 raw_spin_lock_irq(&ctx->lock);
2451 if (event->state <= PERF_EVENT_STATE_OFF) {
2452 raw_spin_unlock_irq(&ctx->lock);
2455 raw_spin_unlock_irq(&ctx->lock);
2457 event_function_call(event, __perf_event_disable, NULL);
2460 void perf_event_disable_local(struct perf_event *event)
2462 event_function_local(event, __perf_event_disable, NULL);
2466 * Strictly speaking kernel users cannot create groups and therefore this
2467 * interface does not need the perf_event_ctx_lock() magic.
2469 void perf_event_disable(struct perf_event *event)
2471 struct perf_event_context *ctx;
2473 ctx = perf_event_ctx_lock(event);
2474 _perf_event_disable(event);
2475 perf_event_ctx_unlock(event, ctx);
2477 EXPORT_SYMBOL_GPL(perf_event_disable);
2479 void perf_event_disable_inatomic(struct perf_event *event)
2481 event->pending_disable = 1;
2482 irq_work_queue(&event->pending_irq);
2485 #define MAX_INTERRUPTS (~0ULL)
2487 static void perf_log_throttle(struct perf_event *event, int enable);
2488 static void perf_log_itrace_start(struct perf_event *event);
2491 event_sched_in(struct perf_event *event, struct perf_event_context *ctx)
2493 struct perf_event_pmu_context *epc = event->pmu_ctx;
2494 struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
2497 WARN_ON_ONCE(event->ctx != ctx);
2499 lockdep_assert_held(&ctx->lock);
2501 if (event->state <= PERF_EVENT_STATE_OFF)
2504 WRITE_ONCE(event->oncpu, smp_processor_id());
2506 * Order event::oncpu write to happen before the ACTIVE state is
2507 * visible. This allows perf_event_{stop,read}() to observe the correct
2508 * ->oncpu if it sees ACTIVE.
2511 perf_event_set_state(event, PERF_EVENT_STATE_ACTIVE);
2514 * Unthrottle events, since we scheduled we might have missed several
2515 * ticks already, also for a heavily scheduling task there is little
2516 * guarantee it'll get a tick in a timely manner.
2518 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
2519 perf_log_throttle(event, 1);
2520 event->hw.interrupts = 0;
2523 perf_pmu_disable(event->pmu);
2525 perf_log_itrace_start(event);
2527 if (event->pmu->add(event, PERF_EF_START)) {
2528 perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
2534 if (!is_software_event(event))
2535 cpc->active_oncpu++;
2536 if (event->attr.freq && event->attr.sample_freq)
2539 if (event->attr.exclusive)
2543 perf_pmu_enable(event->pmu);
2549 group_sched_in(struct perf_event *group_event, struct perf_event_context *ctx)
2551 struct perf_event *event, *partial_group = NULL;
2552 struct pmu *pmu = group_event->pmu_ctx->pmu;
2554 if (group_event->state == PERF_EVENT_STATE_OFF)
2557 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
2559 if (event_sched_in(group_event, ctx))
2563 * Schedule in siblings as one group (if any):
2565 for_each_sibling_event(event, group_event) {
2566 if (event_sched_in(event, ctx)) {
2567 partial_group = event;
2572 if (!pmu->commit_txn(pmu))
2577 * Groups can be scheduled in as one unit only, so undo any
2578 * partial group before returning:
2579 * The events up to the failed event are scheduled out normally.
2581 for_each_sibling_event(event, group_event) {
2582 if (event == partial_group)
2585 event_sched_out(event, ctx);
2587 event_sched_out(group_event, ctx);
2590 pmu->cancel_txn(pmu);
2595 * Work out whether we can put this event group on the CPU now.
2597 static int group_can_go_on(struct perf_event *event, int can_add_hw)
2599 struct perf_event_pmu_context *epc = event->pmu_ctx;
2600 struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
2603 * Groups consisting entirely of software events can always go on.
2605 if (event->group_caps & PERF_EV_CAP_SOFTWARE)
2608 * If an exclusive group is already on, no other hardware
2614 * If this group is exclusive and there are already
2615 * events on the CPU, it can't go on.
2617 if (event->attr.exclusive && !list_empty(get_event_list(event)))
2620 * Otherwise, try to add it if all previous groups were able
2626 static void add_event_to_ctx(struct perf_event *event,
2627 struct perf_event_context *ctx)
2629 list_add_event(event, ctx);
2630 perf_group_attach(event);
2633 static void task_ctx_sched_out(struct perf_event_context *ctx,
2634 enum event_type_t event_type)
2636 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
2638 if (!cpuctx->task_ctx)
2641 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2644 ctx_sched_out(ctx, event_type);
2647 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2648 struct perf_event_context *ctx)
2650 ctx_sched_in(&cpuctx->ctx, EVENT_PINNED);
2652 ctx_sched_in(ctx, EVENT_PINNED);
2653 ctx_sched_in(&cpuctx->ctx, EVENT_FLEXIBLE);
2655 ctx_sched_in(ctx, EVENT_FLEXIBLE);
2659 * We want to maintain the following priority of scheduling:
2660 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2661 * - task pinned (EVENT_PINNED)
2662 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2663 * - task flexible (EVENT_FLEXIBLE).
2665 * In order to avoid unscheduling and scheduling back in everything every
2666 * time an event is added, only do it for the groups of equal priority and
2669 * This can be called after a batch operation on task events, in which case
2670 * event_type is a bit mask of the types of events involved. For CPU events,
2671 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2674 * XXX: ctx_resched() reschedule entire perf_event_context while adding new
2675 * event to the context or enabling existing event in the context. We can
2676 * probably optimize it by rescheduling only affected pmu_ctx.
2678 static void ctx_resched(struct perf_cpu_context *cpuctx,
2679 struct perf_event_context *task_ctx,
2680 enum event_type_t event_type)
2682 bool cpu_event = !!(event_type & EVENT_CPU);
2685 * If pinned groups are involved, flexible groups also need to be
2688 if (event_type & EVENT_PINNED)
2689 event_type |= EVENT_FLEXIBLE;
2691 event_type &= EVENT_ALL;
2693 perf_ctx_disable(&cpuctx->ctx, false);
2695 perf_ctx_disable(task_ctx, false);
2696 task_ctx_sched_out(task_ctx, event_type);
2700 * Decide which cpu ctx groups to schedule out based on the types
2701 * of events that caused rescheduling:
2702 * - EVENT_CPU: schedule out corresponding groups;
2703 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2704 * - otherwise, do nothing more.
2707 ctx_sched_out(&cpuctx->ctx, event_type);
2708 else if (event_type & EVENT_PINNED)
2709 ctx_sched_out(&cpuctx->ctx, EVENT_FLEXIBLE);
2711 perf_event_sched_in(cpuctx, task_ctx);
2713 perf_ctx_enable(&cpuctx->ctx, false);
2715 perf_ctx_enable(task_ctx, false);
2718 void perf_pmu_resched(struct pmu *pmu)
2720 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
2721 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2723 perf_ctx_lock(cpuctx, task_ctx);
2724 ctx_resched(cpuctx, task_ctx, EVENT_ALL|EVENT_CPU);
2725 perf_ctx_unlock(cpuctx, task_ctx);
2729 * Cross CPU call to install and enable a performance event
2731 * Very similar to remote_function() + event_function() but cannot assume that
2732 * things like ctx->is_active and cpuctx->task_ctx are set.
2734 static int __perf_install_in_context(void *info)
2736 struct perf_event *event = info;
2737 struct perf_event_context *ctx = event->ctx;
2738 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
2739 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2740 bool reprogram = true;
2743 raw_spin_lock(&cpuctx->ctx.lock);
2745 raw_spin_lock(&ctx->lock);
2748 reprogram = (ctx->task == current);
2751 * If the task is running, it must be running on this CPU,
2752 * otherwise we cannot reprogram things.
2754 * If its not running, we don't care, ctx->lock will
2755 * serialize against it becoming runnable.
2757 if (task_curr(ctx->task) && !reprogram) {
2762 WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2763 } else if (task_ctx) {
2764 raw_spin_lock(&task_ctx->lock);
2767 #ifdef CONFIG_CGROUP_PERF
2768 if (event->state > PERF_EVENT_STATE_OFF && is_cgroup_event(event)) {
2770 * If the current cgroup doesn't match the event's
2771 * cgroup, we should not try to schedule it.
2773 struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
2774 reprogram = cgroup_is_descendant(cgrp->css.cgroup,
2775 event->cgrp->css.cgroup);
2780 ctx_sched_out(ctx, EVENT_TIME);
2781 add_event_to_ctx(event, ctx);
2782 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2784 add_event_to_ctx(event, ctx);
2788 perf_ctx_unlock(cpuctx, task_ctx);
2793 static bool exclusive_event_installable(struct perf_event *event,
2794 struct perf_event_context *ctx);
2797 * Attach a performance event to a context.
2799 * Very similar to event_function_call, see comment there.
2802 perf_install_in_context(struct perf_event_context *ctx,
2803 struct perf_event *event,
2806 struct task_struct *task = READ_ONCE(ctx->task);
2808 lockdep_assert_held(&ctx->mutex);
2810 WARN_ON_ONCE(!exclusive_event_installable(event, ctx));
2812 if (event->cpu != -1)
2813 WARN_ON_ONCE(event->cpu != cpu);
2816 * Ensures that if we can observe event->ctx, both the event and ctx
2817 * will be 'complete'. See perf_iterate_sb_cpu().
2819 smp_store_release(&event->ctx, ctx);
2822 * perf_event_attr::disabled events will not run and can be initialized
2823 * without IPI. Except when this is the first event for the context, in
2824 * that case we need the magic of the IPI to set ctx->is_active.
2826 * The IOC_ENABLE that is sure to follow the creation of a disabled
2827 * event will issue the IPI and reprogram the hardware.
2829 if (__perf_effective_state(event) == PERF_EVENT_STATE_OFF &&
2830 ctx->nr_events && !is_cgroup_event(event)) {
2831 raw_spin_lock_irq(&ctx->lock);
2832 if (ctx->task == TASK_TOMBSTONE) {
2833 raw_spin_unlock_irq(&ctx->lock);
2836 add_event_to_ctx(event, ctx);
2837 raw_spin_unlock_irq(&ctx->lock);
2842 cpu_function_call(cpu, __perf_install_in_context, event);
2847 * Should not happen, we validate the ctx is still alive before calling.
2849 if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
2853 * Installing events is tricky because we cannot rely on ctx->is_active
2854 * to be set in case this is the nr_events 0 -> 1 transition.
2856 * Instead we use task_curr(), which tells us if the task is running.
2857 * However, since we use task_curr() outside of rq::lock, we can race
2858 * against the actual state. This means the result can be wrong.
2860 * If we get a false positive, we retry, this is harmless.
2862 * If we get a false negative, things are complicated. If we are after
2863 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2864 * value must be correct. If we're before, it doesn't matter since
2865 * perf_event_context_sched_in() will program the counter.
2867 * However, this hinges on the remote context switch having observed
2868 * our task->perf_event_ctxp[] store, such that it will in fact take
2869 * ctx::lock in perf_event_context_sched_in().
2871 * We do this by task_function_call(), if the IPI fails to hit the task
2872 * we know any future context switch of task must see the
2873 * perf_event_ctpx[] store.
2877 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2878 * task_cpu() load, such that if the IPI then does not find the task
2879 * running, a future context switch of that task must observe the
2884 if (!task_function_call(task, __perf_install_in_context, event))
2887 raw_spin_lock_irq(&ctx->lock);
2889 if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
2891 * Cannot happen because we already checked above (which also
2892 * cannot happen), and we hold ctx->mutex, which serializes us
2893 * against perf_event_exit_task_context().
2895 raw_spin_unlock_irq(&ctx->lock);
2899 * If the task is not running, ctx->lock will avoid it becoming so,
2900 * thus we can safely install the event.
2902 if (task_curr(task)) {
2903 raw_spin_unlock_irq(&ctx->lock);
2906 add_event_to_ctx(event, ctx);
2907 raw_spin_unlock_irq(&ctx->lock);
2911 * Cross CPU call to enable a performance event
2913 static void __perf_event_enable(struct perf_event *event,
2914 struct perf_cpu_context *cpuctx,
2915 struct perf_event_context *ctx,
2918 struct perf_event *leader = event->group_leader;
2919 struct perf_event_context *task_ctx;
2921 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2922 event->state <= PERF_EVENT_STATE_ERROR)
2926 ctx_sched_out(ctx, EVENT_TIME);
2928 perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
2929 perf_cgroup_event_enable(event, ctx);
2931 if (!ctx->is_active)
2934 if (!event_filter_match(event)) {
2935 ctx_sched_in(ctx, EVENT_TIME);
2940 * If the event is in a group and isn't the group leader,
2941 * then don't put it on unless the group is on.
2943 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
2944 ctx_sched_in(ctx, EVENT_TIME);
2948 task_ctx = cpuctx->task_ctx;
2950 WARN_ON_ONCE(task_ctx != ctx);
2952 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2958 * If event->ctx is a cloned context, callers must make sure that
2959 * every task struct that event->ctx->task could possibly point to
2960 * remains valid. This condition is satisfied when called through
2961 * perf_event_for_each_child or perf_event_for_each as described
2962 * for perf_event_disable.
2964 static void _perf_event_enable(struct perf_event *event)
2966 struct perf_event_context *ctx = event->ctx;
2968 raw_spin_lock_irq(&ctx->lock);
2969 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2970 event->state < PERF_EVENT_STATE_ERROR) {
2972 raw_spin_unlock_irq(&ctx->lock);
2977 * If the event is in error state, clear that first.
2979 * That way, if we see the event in error state below, we know that it
2980 * has gone back into error state, as distinct from the task having
2981 * been scheduled away before the cross-call arrived.
2983 if (event->state == PERF_EVENT_STATE_ERROR) {
2985 * Detached SIBLING events cannot leave ERROR state.
2987 if (event->event_caps & PERF_EV_CAP_SIBLING &&
2988 event->group_leader == event)
2991 event->state = PERF_EVENT_STATE_OFF;
2993 raw_spin_unlock_irq(&ctx->lock);
2995 event_function_call(event, __perf_event_enable, NULL);
2999 * See perf_event_disable();
3001 void perf_event_enable(struct perf_event *event)
3003 struct perf_event_context *ctx;
3005 ctx = perf_event_ctx_lock(event);
3006 _perf_event_enable(event);
3007 perf_event_ctx_unlock(event, ctx);
3009 EXPORT_SYMBOL_GPL(perf_event_enable);
3011 struct stop_event_data {
3012 struct perf_event *event;
3013 unsigned int restart;
3016 static int __perf_event_stop(void *info)
3018 struct stop_event_data *sd = info;
3019 struct perf_event *event = sd->event;
3021 /* if it's already INACTIVE, do nothing */
3022 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
3025 /* matches smp_wmb() in event_sched_in() */
3029 * There is a window with interrupts enabled before we get here,
3030 * so we need to check again lest we try to stop another CPU's event.
3032 if (READ_ONCE(event->oncpu) != smp_processor_id())
3035 event->pmu->stop(event, PERF_EF_UPDATE);
3038 * May race with the actual stop (through perf_pmu_output_stop()),
3039 * but it is only used for events with AUX ring buffer, and such
3040 * events will refuse to restart because of rb::aux_mmap_count==0,
3041 * see comments in perf_aux_output_begin().
3043 * Since this is happening on an event-local CPU, no trace is lost
3047 event->pmu->start(event, 0);
3052 static int perf_event_stop(struct perf_event *event, int restart)
3054 struct stop_event_data sd = {
3061 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
3064 /* matches smp_wmb() in event_sched_in() */
3068 * We only want to restart ACTIVE events, so if the event goes
3069 * inactive here (event->oncpu==-1), there's nothing more to do;
3070 * fall through with ret==-ENXIO.
3072 ret = cpu_function_call(READ_ONCE(event->oncpu),
3073 __perf_event_stop, &sd);
3074 } while (ret == -EAGAIN);
3080 * In order to contain the amount of racy and tricky in the address filter
3081 * configuration management, it is a two part process:
3083 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
3084 * we update the addresses of corresponding vmas in
3085 * event::addr_filter_ranges array and bump the event::addr_filters_gen;
3086 * (p2) when an event is scheduled in (pmu::add), it calls
3087 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
3088 * if the generation has changed since the previous call.
3090 * If (p1) happens while the event is active, we restart it to force (p2).
3092 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
3093 * pre-existing mappings, called once when new filters arrive via SET_FILTER
3095 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
3096 * registered mapping, called for every new mmap(), with mm::mmap_lock down
3098 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
3101 void perf_event_addr_filters_sync(struct perf_event *event)
3103 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
3105 if (!has_addr_filter(event))
3108 raw_spin_lock(&ifh->lock);
3109 if (event->addr_filters_gen != event->hw.addr_filters_gen) {
3110 event->pmu->addr_filters_sync(event);
3111 event->hw.addr_filters_gen = event->addr_filters_gen;
3113 raw_spin_unlock(&ifh->lock);
3115 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
3117 static int _perf_event_refresh(struct perf_event *event, int refresh)
3120 * not supported on inherited events
3122 if (event->attr.inherit || !is_sampling_event(event))
3125 atomic_add(refresh, &event->event_limit);
3126 _perf_event_enable(event);
3132 * See perf_event_disable()
3134 int perf_event_refresh(struct perf_event *event, int refresh)
3136 struct perf_event_context *ctx;
3139 ctx = perf_event_ctx_lock(event);
3140 ret = _perf_event_refresh(event, refresh);
3141 perf_event_ctx_unlock(event, ctx);
3145 EXPORT_SYMBOL_GPL(perf_event_refresh);
3147 static int perf_event_modify_breakpoint(struct perf_event *bp,
3148 struct perf_event_attr *attr)
3152 _perf_event_disable(bp);
3154 err = modify_user_hw_breakpoint_check(bp, attr, true);
3156 if (!bp->attr.disabled)
3157 _perf_event_enable(bp);
3163 * Copy event-type-independent attributes that may be modified.
3165 static void perf_event_modify_copy_attr(struct perf_event_attr *to,
3166 const struct perf_event_attr *from)
3168 to->sig_data = from->sig_data;
3171 static int perf_event_modify_attr(struct perf_event *event,
3172 struct perf_event_attr *attr)
3174 int (*func)(struct perf_event *, struct perf_event_attr *);
3175 struct perf_event *child;
3178 if (event->attr.type != attr->type)
3181 switch (event->attr.type) {
3182 case PERF_TYPE_BREAKPOINT:
3183 func = perf_event_modify_breakpoint;
3186 /* Place holder for future additions. */
3190 WARN_ON_ONCE(event->ctx->parent_ctx);
3192 mutex_lock(&event->child_mutex);
3194 * Event-type-independent attributes must be copied before event-type
3195 * modification, which will validate that final attributes match the
3196 * source attributes after all relevant attributes have been copied.
3198 perf_event_modify_copy_attr(&event->attr, attr);
3199 err = func(event, attr);
3202 list_for_each_entry(child, &event->child_list, child_list) {
3203 perf_event_modify_copy_attr(&child->attr, attr);
3204 err = func(child, attr);
3209 mutex_unlock(&event->child_mutex);
3213 static void __pmu_ctx_sched_out(struct perf_event_pmu_context *pmu_ctx,
3214 enum event_type_t event_type)
3216 struct perf_event_context *ctx = pmu_ctx->ctx;
3217 struct perf_event *event, *tmp;
3218 struct pmu *pmu = pmu_ctx->pmu;
3220 if (ctx->task && !ctx->is_active) {
3221 struct perf_cpu_pmu_context *cpc;
3223 cpc = this_cpu_ptr(pmu->cpu_pmu_context);
3224 WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
3225 cpc->task_epc = NULL;
3231 perf_pmu_disable(pmu);
3232 if (event_type & EVENT_PINNED) {
3233 list_for_each_entry_safe(event, tmp,
3234 &pmu_ctx->pinned_active,
3236 group_sched_out(event, ctx);
3239 if (event_type & EVENT_FLEXIBLE) {
3240 list_for_each_entry_safe(event, tmp,
3241 &pmu_ctx->flexible_active,
3243 group_sched_out(event, ctx);
3245 * Since we cleared EVENT_FLEXIBLE, also clear
3246 * rotate_necessary, is will be reset by
3247 * ctx_flexible_sched_in() when needed.
3249 pmu_ctx->rotate_necessary = 0;
3251 perf_pmu_enable(pmu);
3255 ctx_sched_out(struct perf_event_context *ctx, enum event_type_t event_type)
3257 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
3258 struct perf_event_pmu_context *pmu_ctx;
3259 int is_active = ctx->is_active;
3260 bool cgroup = event_type & EVENT_CGROUP;
3262 event_type &= ~EVENT_CGROUP;
3264 lockdep_assert_held(&ctx->lock);
3266 if (likely(!ctx->nr_events)) {
3268 * See __perf_remove_from_context().
3270 WARN_ON_ONCE(ctx->is_active);
3272 WARN_ON_ONCE(cpuctx->task_ctx);
3277 * Always update time if it was set; not only when it changes.
3278 * Otherwise we can 'forget' to update time for any but the last
3279 * context we sched out. For example:
3281 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
3282 * ctx_sched_out(.event_type = EVENT_PINNED)
3284 * would only update time for the pinned events.
3286 if (is_active & EVENT_TIME) {
3287 /* update (and stop) ctx time */
3288 update_context_time(ctx);
3289 update_cgrp_time_from_cpuctx(cpuctx, ctx == &cpuctx->ctx);
3291 * CPU-release for the below ->is_active store,
3292 * see __load_acquire() in perf_event_time_now()
3297 ctx->is_active &= ~event_type;
3298 if (!(ctx->is_active & EVENT_ALL))
3302 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3303 if (!ctx->is_active)
3304 cpuctx->task_ctx = NULL;
3307 is_active ^= ctx->is_active; /* changed bits */
3309 list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
3310 if (cgroup && !pmu_ctx->nr_cgroups)
3312 __pmu_ctx_sched_out(pmu_ctx, is_active);
3317 * Test whether two contexts are equivalent, i.e. whether they have both been
3318 * cloned from the same version of the same context.
3320 * Equivalence is measured using a generation number in the context that is
3321 * incremented on each modification to it; see unclone_ctx(), list_add_event()
3322 * and list_del_event().
3324 static int context_equiv(struct perf_event_context *ctx1,
3325 struct perf_event_context *ctx2)
3327 lockdep_assert_held(&ctx1->lock);
3328 lockdep_assert_held(&ctx2->lock);
3330 /* Pinning disables the swap optimization */
3331 if (ctx1->pin_count || ctx2->pin_count)
3334 /* If ctx1 is the parent of ctx2 */
3335 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
3338 /* If ctx2 is the parent of ctx1 */
3339 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
3343 * If ctx1 and ctx2 have the same parent; we flatten the parent
3344 * hierarchy, see perf_event_init_context().
3346 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
3347 ctx1->parent_gen == ctx2->parent_gen)
3354 static void __perf_event_sync_stat(struct perf_event *event,
3355 struct perf_event *next_event)
3359 if (!event->attr.inherit_stat)
3363 * Update the event value, we cannot use perf_event_read()
3364 * because we're in the middle of a context switch and have IRQs
3365 * disabled, which upsets smp_call_function_single(), however
3366 * we know the event must be on the current CPU, therefore we
3367 * don't need to use it.
3369 if (event->state == PERF_EVENT_STATE_ACTIVE)
3370 event->pmu->read(event);
3372 perf_event_update_time(event);
3375 * In order to keep per-task stats reliable we need to flip the event
3376 * values when we flip the contexts.
3378 value = local64_read(&next_event->count);
3379 value = local64_xchg(&event->count, value);
3380 local64_set(&next_event->count, value);
3382 swap(event->total_time_enabled, next_event->total_time_enabled);
3383 swap(event->total_time_running, next_event->total_time_running);
3386 * Since we swizzled the values, update the user visible data too.
3388 perf_event_update_userpage(event);
3389 perf_event_update_userpage(next_event);
3392 static void perf_event_sync_stat(struct perf_event_context *ctx,
3393 struct perf_event_context *next_ctx)
3395 struct perf_event *event, *next_event;
3400 update_context_time(ctx);
3402 event = list_first_entry(&ctx->event_list,
3403 struct perf_event, event_entry);
3405 next_event = list_first_entry(&next_ctx->event_list,
3406 struct perf_event, event_entry);
3408 while (&event->event_entry != &ctx->event_list &&
3409 &next_event->event_entry != &next_ctx->event_list) {
3411 __perf_event_sync_stat(event, next_event);
3413 event = list_next_entry(event, event_entry);
3414 next_event = list_next_entry(next_event, event_entry);
3418 #define double_list_for_each_entry(pos1, pos2, head1, head2, member) \
3419 for (pos1 = list_first_entry(head1, typeof(*pos1), member), \
3420 pos2 = list_first_entry(head2, typeof(*pos2), member); \
3421 !list_entry_is_head(pos1, head1, member) && \
3422 !list_entry_is_head(pos2, head2, member); \
3423 pos1 = list_next_entry(pos1, member), \
3424 pos2 = list_next_entry(pos2, member))
3426 static void perf_event_swap_task_ctx_data(struct perf_event_context *prev_ctx,
3427 struct perf_event_context *next_ctx)
3429 struct perf_event_pmu_context *prev_epc, *next_epc;
3431 if (!prev_ctx->nr_task_data)
3434 double_list_for_each_entry(prev_epc, next_epc,
3435 &prev_ctx->pmu_ctx_list, &next_ctx->pmu_ctx_list,
3438 if (WARN_ON_ONCE(prev_epc->pmu != next_epc->pmu))
3442 * PMU specific parts of task perf context can require
3443 * additional synchronization. As an example of such
3444 * synchronization see implementation details of Intel
3445 * LBR call stack data profiling;
3447 if (prev_epc->pmu->swap_task_ctx)
3448 prev_epc->pmu->swap_task_ctx(prev_epc, next_epc);
3450 swap(prev_epc->task_ctx_data, next_epc->task_ctx_data);
3454 static void perf_ctx_sched_task_cb(struct perf_event_context *ctx, bool sched_in)
3456 struct perf_event_pmu_context *pmu_ctx;
3457 struct perf_cpu_pmu_context *cpc;
3459 list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
3460 cpc = this_cpu_ptr(pmu_ctx->pmu->cpu_pmu_context);
3462 if (cpc->sched_cb_usage && pmu_ctx->pmu->sched_task)
3463 pmu_ctx->pmu->sched_task(pmu_ctx, sched_in);
3468 perf_event_context_sched_out(struct task_struct *task, struct task_struct *next)
3470 struct perf_event_context *ctx = task->perf_event_ctxp;
3471 struct perf_event_context *next_ctx;
3472 struct perf_event_context *parent, *next_parent;
3479 next_ctx = rcu_dereference(next->perf_event_ctxp);
3483 parent = rcu_dereference(ctx->parent_ctx);
3484 next_parent = rcu_dereference(next_ctx->parent_ctx);
3486 /* If neither context have a parent context; they cannot be clones. */
3487 if (!parent && !next_parent)
3490 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
3492 * Looks like the two contexts are clones, so we might be
3493 * able to optimize the context switch. We lock both
3494 * contexts and check that they are clones under the
3495 * lock (including re-checking that neither has been
3496 * uncloned in the meantime). It doesn't matter which
3497 * order we take the locks because no other cpu could
3498 * be trying to lock both of these tasks.
3500 raw_spin_lock(&ctx->lock);
3501 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
3502 if (context_equiv(ctx, next_ctx)) {
3504 perf_ctx_disable(ctx, false);
3506 /* PMIs are disabled; ctx->nr_pending is stable. */
3507 if (local_read(&ctx->nr_pending) ||
3508 local_read(&next_ctx->nr_pending)) {
3510 * Must not swap out ctx when there's pending
3511 * events that rely on the ctx->task relation.
3513 raw_spin_unlock(&next_ctx->lock);
3518 WRITE_ONCE(ctx->task, next);
3519 WRITE_ONCE(next_ctx->task, task);
3521 perf_ctx_sched_task_cb(ctx, false);
3522 perf_event_swap_task_ctx_data(ctx, next_ctx);
3524 perf_ctx_enable(ctx, false);
3527 * RCU_INIT_POINTER here is safe because we've not
3528 * modified the ctx and the above modification of
3529 * ctx->task and ctx->task_ctx_data are immaterial
3530 * since those values are always verified under
3531 * ctx->lock which we're now holding.
3533 RCU_INIT_POINTER(task->perf_event_ctxp, next_ctx);
3534 RCU_INIT_POINTER(next->perf_event_ctxp, ctx);
3538 perf_event_sync_stat(ctx, next_ctx);
3540 raw_spin_unlock(&next_ctx->lock);
3541 raw_spin_unlock(&ctx->lock);
3547 raw_spin_lock(&ctx->lock);
3548 perf_ctx_disable(ctx, false);
3551 perf_ctx_sched_task_cb(ctx, false);
3552 task_ctx_sched_out(ctx, EVENT_ALL);
3554 perf_ctx_enable(ctx, false);
3555 raw_spin_unlock(&ctx->lock);
3559 static DEFINE_PER_CPU(struct list_head, sched_cb_list);
3560 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
3562 void perf_sched_cb_dec(struct pmu *pmu)
3564 struct perf_cpu_pmu_context *cpc = this_cpu_ptr(pmu->cpu_pmu_context);
3566 this_cpu_dec(perf_sched_cb_usages);
3569 if (!--cpc->sched_cb_usage)
3570 list_del(&cpc->sched_cb_entry);
3574 void perf_sched_cb_inc(struct pmu *pmu)
3576 struct perf_cpu_pmu_context *cpc = this_cpu_ptr(pmu->cpu_pmu_context);
3578 if (!cpc->sched_cb_usage++)
3579 list_add(&cpc->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
3582 this_cpu_inc(perf_sched_cb_usages);
3586 * This function provides the context switch callback to the lower code
3587 * layer. It is invoked ONLY when the context switch callback is enabled.
3589 * This callback is relevant even to per-cpu events; for example multi event
3590 * PEBS requires this to provide PID/TID information. This requires we flush
3591 * all queued PEBS records before we context switch to a new task.
3593 static void __perf_pmu_sched_task(struct perf_cpu_pmu_context *cpc, bool sched_in)
3595 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
3600 /* software PMUs will not have sched_task */
3601 if (WARN_ON_ONCE(!pmu->sched_task))
3604 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3605 perf_pmu_disable(pmu);
3607 pmu->sched_task(cpc->task_epc, sched_in);
3609 perf_pmu_enable(pmu);
3610 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3613 static void perf_pmu_sched_task(struct task_struct *prev,
3614 struct task_struct *next,
3617 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
3618 struct perf_cpu_pmu_context *cpc;
3620 /* cpuctx->task_ctx will be handled in perf_event_context_sched_in/out */
3621 if (prev == next || cpuctx->task_ctx)
3624 list_for_each_entry(cpc, this_cpu_ptr(&sched_cb_list), sched_cb_entry)
3625 __perf_pmu_sched_task(cpc, sched_in);
3628 static void perf_event_switch(struct task_struct *task,
3629 struct task_struct *next_prev, bool sched_in);
3632 * Called from scheduler to remove the events of the current task,
3633 * with interrupts disabled.
3635 * We stop each event and update the event value in event->count.
3637 * This does not protect us against NMI, but disable()
3638 * sets the disabled bit in the control field of event _before_
3639 * accessing the event control register. If a NMI hits, then it will
3640 * not restart the event.
3642 void __perf_event_task_sched_out(struct task_struct *task,
3643 struct task_struct *next)
3645 if (__this_cpu_read(perf_sched_cb_usages))
3646 perf_pmu_sched_task(task, next, false);
3648 if (atomic_read(&nr_switch_events))
3649 perf_event_switch(task, next, false);
3651 perf_event_context_sched_out(task, next);
3654 * if cgroup events exist on this CPU, then we need
3655 * to check if we have to switch out PMU state.
3656 * cgroup event are system-wide mode only
3658 perf_cgroup_switch(next);
3661 static bool perf_less_group_idx(const void *l, const void *r)
3663 const struct perf_event *le = *(const struct perf_event **)l;
3664 const struct perf_event *re = *(const struct perf_event **)r;
3666 return le->group_index < re->group_index;
3669 static void swap_ptr(void *l, void *r)
3671 void **lp = l, **rp = r;
3676 static const struct min_heap_callbacks perf_min_heap = {
3677 .elem_size = sizeof(struct perf_event *),
3678 .less = perf_less_group_idx,
3682 static void __heap_add(struct min_heap *heap, struct perf_event *event)
3684 struct perf_event **itrs = heap->data;
3687 itrs[heap->nr] = event;
3692 static void __link_epc(struct perf_event_pmu_context *pmu_ctx)
3694 struct perf_cpu_pmu_context *cpc;
3696 if (!pmu_ctx->ctx->task)
3699 cpc = this_cpu_ptr(pmu_ctx->pmu->cpu_pmu_context);
3700 WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
3701 cpc->task_epc = pmu_ctx;
3704 static noinline int visit_groups_merge(struct perf_event_context *ctx,
3705 struct perf_event_groups *groups, int cpu,
3707 int (*func)(struct perf_event *, void *),
3710 #ifdef CONFIG_CGROUP_PERF
3711 struct cgroup_subsys_state *css = NULL;
3713 struct perf_cpu_context *cpuctx = NULL;
3714 /* Space for per CPU and/or any CPU event iterators. */
3715 struct perf_event *itrs[2];
3716 struct min_heap event_heap;
3717 struct perf_event **evt;
3720 if (pmu->filter && pmu->filter(pmu, cpu))
3724 cpuctx = this_cpu_ptr(&perf_cpu_context);
3725 event_heap = (struct min_heap){
3726 .data = cpuctx->heap,
3728 .size = cpuctx->heap_size,
3731 lockdep_assert_held(&cpuctx->ctx.lock);
3733 #ifdef CONFIG_CGROUP_PERF
3735 css = &cpuctx->cgrp->css;
3738 event_heap = (struct min_heap){
3741 .size = ARRAY_SIZE(itrs),
3743 /* Events not within a CPU context may be on any CPU. */
3744 __heap_add(&event_heap, perf_event_groups_first(groups, -1, pmu, NULL));
3746 evt = event_heap.data;
3748 __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, NULL));
3750 #ifdef CONFIG_CGROUP_PERF
3751 for (; css; css = css->parent)
3752 __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, css->cgroup));
3755 if (event_heap.nr) {
3756 __link_epc((*evt)->pmu_ctx);
3757 perf_assert_pmu_disabled((*evt)->pmu_ctx->pmu);
3760 min_heapify_all(&event_heap, &perf_min_heap);
3762 while (event_heap.nr) {
3763 ret = func(*evt, data);
3767 *evt = perf_event_groups_next(*evt, pmu);
3769 min_heapify(&event_heap, 0, &perf_min_heap);
3771 min_heap_pop(&event_heap, &perf_min_heap);
3778 * Because the userpage is strictly per-event (there is no concept of context,
3779 * so there cannot be a context indirection), every userpage must be updated
3780 * when context time starts :-(
3782 * IOW, we must not miss EVENT_TIME edges.
3784 static inline bool event_update_userpage(struct perf_event *event)
3786 if (likely(!atomic_read(&event->mmap_count)))
3789 perf_event_update_time(event);
3790 perf_event_update_userpage(event);
3795 static inline void group_update_userpage(struct perf_event *group_event)
3797 struct perf_event *event;
3799 if (!event_update_userpage(group_event))
3802 for_each_sibling_event(event, group_event)
3803 event_update_userpage(event);
3806 static int merge_sched_in(struct perf_event *event, void *data)
3808 struct perf_event_context *ctx = event->ctx;
3809 int *can_add_hw = data;
3811 if (event->state <= PERF_EVENT_STATE_OFF)
3814 if (!event_filter_match(event))
3817 if (group_can_go_on(event, *can_add_hw)) {
3818 if (!group_sched_in(event, ctx))
3819 list_add_tail(&event->active_list, get_event_list(event));
3822 if (event->state == PERF_EVENT_STATE_INACTIVE) {
3824 if (event->attr.pinned) {
3825 perf_cgroup_event_disable(event, ctx);
3826 perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
3828 struct perf_cpu_pmu_context *cpc;
3830 event->pmu_ctx->rotate_necessary = 1;
3831 cpc = this_cpu_ptr(event->pmu_ctx->pmu->cpu_pmu_context);
3832 perf_mux_hrtimer_restart(cpc);
3833 group_update_userpage(event);
3840 static void pmu_groups_sched_in(struct perf_event_context *ctx,
3841 struct perf_event_groups *groups,
3845 visit_groups_merge(ctx, groups, smp_processor_id(), pmu,
3846 merge_sched_in, &can_add_hw);
3849 static void ctx_groups_sched_in(struct perf_event_context *ctx,
3850 struct perf_event_groups *groups,
3853 struct perf_event_pmu_context *pmu_ctx;
3855 list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
3856 if (cgroup && !pmu_ctx->nr_cgroups)
3858 pmu_groups_sched_in(ctx, groups, pmu_ctx->pmu);
3862 static void __pmu_ctx_sched_in(struct perf_event_context *ctx,
3865 pmu_groups_sched_in(ctx, &ctx->flexible_groups, pmu);
3869 ctx_sched_in(struct perf_event_context *ctx, enum event_type_t event_type)
3871 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
3872 int is_active = ctx->is_active;
3873 bool cgroup = event_type & EVENT_CGROUP;
3875 event_type &= ~EVENT_CGROUP;
3877 lockdep_assert_held(&ctx->lock);
3879 if (likely(!ctx->nr_events))
3882 if (!(is_active & EVENT_TIME)) {
3883 /* start ctx time */
3884 __update_context_time(ctx, false);
3885 perf_cgroup_set_timestamp(cpuctx);
3887 * CPU-release for the below ->is_active store,
3888 * see __load_acquire() in perf_event_time_now()
3893 ctx->is_active |= (event_type | EVENT_TIME);
3896 cpuctx->task_ctx = ctx;
3898 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3901 is_active ^= ctx->is_active; /* changed bits */
3904 * First go through the list and put on any pinned groups
3905 * in order to give them the best chance of going on.
3907 if (is_active & EVENT_PINNED)
3908 ctx_groups_sched_in(ctx, &ctx->pinned_groups, cgroup);
3910 /* Then walk through the lower prio flexible groups */
3911 if (is_active & EVENT_FLEXIBLE)
3912 ctx_groups_sched_in(ctx, &ctx->flexible_groups, cgroup);
3915 static void perf_event_context_sched_in(struct task_struct *task)
3917 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
3918 struct perf_event_context *ctx;
3921 ctx = rcu_dereference(task->perf_event_ctxp);
3925 if (cpuctx->task_ctx == ctx) {
3926 perf_ctx_lock(cpuctx, ctx);
3927 perf_ctx_disable(ctx, false);
3929 perf_ctx_sched_task_cb(ctx, true);
3931 perf_ctx_enable(ctx, false);
3932 perf_ctx_unlock(cpuctx, ctx);
3936 perf_ctx_lock(cpuctx, ctx);
3938 * We must check ctx->nr_events while holding ctx->lock, such
3939 * that we serialize against perf_install_in_context().
3941 if (!ctx->nr_events)
3944 perf_ctx_disable(ctx, false);
3946 * We want to keep the following priority order:
3947 * cpu pinned (that don't need to move), task pinned,
3948 * cpu flexible, task flexible.
3950 * However, if task's ctx is not carrying any pinned
3951 * events, no need to flip the cpuctx's events around.
3953 if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) {
3954 perf_ctx_disable(&cpuctx->ctx, false);
3955 ctx_sched_out(&cpuctx->ctx, EVENT_FLEXIBLE);
3958 perf_event_sched_in(cpuctx, ctx);
3960 perf_ctx_sched_task_cb(cpuctx->task_ctx, true);
3962 if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
3963 perf_ctx_enable(&cpuctx->ctx, false);
3965 perf_ctx_enable(ctx, false);
3968 perf_ctx_unlock(cpuctx, ctx);
3974 * Called from scheduler to add the events of the current task
3975 * with interrupts disabled.
3977 * We restore the event value and then enable it.
3979 * This does not protect us against NMI, but enable()
3980 * sets the enabled bit in the control field of event _before_
3981 * accessing the event control register. If a NMI hits, then it will
3982 * keep the event running.
3984 void __perf_event_task_sched_in(struct task_struct *prev,
3985 struct task_struct *task)
3987 perf_event_context_sched_in(task);
3989 if (atomic_read(&nr_switch_events))
3990 perf_event_switch(task, prev, true);
3992 if (__this_cpu_read(perf_sched_cb_usages))
3993 perf_pmu_sched_task(prev, task, true);
3996 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
3998 u64 frequency = event->attr.sample_freq;
3999 u64 sec = NSEC_PER_SEC;
4000 u64 divisor, dividend;
4002 int count_fls, nsec_fls, frequency_fls, sec_fls;
4004 count_fls = fls64(count);
4005 nsec_fls = fls64(nsec);
4006 frequency_fls = fls64(frequency);
4010 * We got @count in @nsec, with a target of sample_freq HZ
4011 * the target period becomes:
4014 * period = -------------------
4015 * @nsec * sample_freq
4020 * Reduce accuracy by one bit such that @a and @b converge
4021 * to a similar magnitude.
4023 #define REDUCE_FLS(a, b) \
4025 if (a##_fls > b##_fls) { \
4035 * Reduce accuracy until either term fits in a u64, then proceed with
4036 * the other, so that finally we can do a u64/u64 division.
4038 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
4039 REDUCE_FLS(nsec, frequency);
4040 REDUCE_FLS(sec, count);
4043 if (count_fls + sec_fls > 64) {
4044 divisor = nsec * frequency;
4046 while (count_fls + sec_fls > 64) {
4047 REDUCE_FLS(count, sec);
4051 dividend = count * sec;
4053 dividend = count * sec;
4055 while (nsec_fls + frequency_fls > 64) {
4056 REDUCE_FLS(nsec, frequency);
4060 divisor = nsec * frequency;
4066 return div64_u64(dividend, divisor);
4069 static DEFINE_PER_CPU(int, perf_throttled_count);
4070 static DEFINE_PER_CPU(u64, perf_throttled_seq);
4072 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
4074 struct hw_perf_event *hwc = &event->hw;
4075 s64 period, sample_period;
4078 period = perf_calculate_period(event, nsec, count);
4080 delta = (s64)(period - hwc->sample_period);
4081 delta = (delta + 7) / 8; /* low pass filter */
4083 sample_period = hwc->sample_period + delta;
4088 hwc->sample_period = sample_period;
4090 if (local64_read(&hwc->period_left) > 8*sample_period) {
4092 event->pmu->stop(event, PERF_EF_UPDATE);
4094 local64_set(&hwc->period_left, 0);
4097 event->pmu->start(event, PERF_EF_RELOAD);
4102 * combine freq adjustment with unthrottling to avoid two passes over the
4103 * events. At the same time, make sure, having freq events does not change
4104 * the rate of unthrottling as that would introduce bias.
4107 perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
4109 struct perf_event *event;
4110 struct hw_perf_event *hwc;
4111 u64 now, period = TICK_NSEC;
4115 * only need to iterate over all events iff:
4116 * - context have events in frequency mode (needs freq adjust)
4117 * - there are events to unthrottle on this cpu
4119 if (!(ctx->nr_freq || unthrottle))
4122 raw_spin_lock(&ctx->lock);
4124 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
4125 if (event->state != PERF_EVENT_STATE_ACTIVE)
4128 // XXX use visit thingy to avoid the -1,cpu match
4129 if (!event_filter_match(event))
4132 perf_pmu_disable(event->pmu);
4136 if (hwc->interrupts == MAX_INTERRUPTS) {
4137 hwc->interrupts = 0;
4138 perf_log_throttle(event, 1);
4139 event->pmu->start(event, 0);
4142 if (!event->attr.freq || !event->attr.sample_freq)
4146 * stop the event and update event->count
4148 event->pmu->stop(event, PERF_EF_UPDATE);
4150 now = local64_read(&event->count);
4151 delta = now - hwc->freq_count_stamp;
4152 hwc->freq_count_stamp = now;
4156 * reload only if value has changed
4157 * we have stopped the event so tell that
4158 * to perf_adjust_period() to avoid stopping it
4162 perf_adjust_period(event, period, delta, false);
4164 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
4166 perf_pmu_enable(event->pmu);
4169 raw_spin_unlock(&ctx->lock);
4173 * Move @event to the tail of the @ctx's elegible events.
4175 static void rotate_ctx(struct perf_event_context *ctx, struct perf_event *event)
4178 * Rotate the first entry last of non-pinned groups. Rotation might be
4179 * disabled by the inheritance code.
4181 if (ctx->rotate_disable)
4184 perf_event_groups_delete(&ctx->flexible_groups, event);
4185 perf_event_groups_insert(&ctx->flexible_groups, event);
4188 /* pick an event from the flexible_groups to rotate */
4189 static inline struct perf_event *
4190 ctx_event_to_rotate(struct perf_event_pmu_context *pmu_ctx)
4192 struct perf_event *event;
4193 struct rb_node *node;
4194 struct rb_root *tree;
4195 struct __group_key key = {
4196 .pmu = pmu_ctx->pmu,
4199 /* pick the first active flexible event */
4200 event = list_first_entry_or_null(&pmu_ctx->flexible_active,
4201 struct perf_event, active_list);
4205 /* if no active flexible event, pick the first event */
4206 tree = &pmu_ctx->ctx->flexible_groups.tree;
4208 if (!pmu_ctx->ctx->task) {
4209 key.cpu = smp_processor_id();
4211 node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
4213 event = __node_2_pe(node);
4218 node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
4220 event = __node_2_pe(node);
4224 key.cpu = smp_processor_id();
4225 node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
4227 event = __node_2_pe(node);
4231 * Unconditionally clear rotate_necessary; if ctx_flexible_sched_in()
4232 * finds there are unschedulable events, it will set it again.
4234 pmu_ctx->rotate_necessary = 0;
4239 static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc)
4241 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
4242 struct perf_event_pmu_context *cpu_epc, *task_epc = NULL;
4243 struct perf_event *cpu_event = NULL, *task_event = NULL;
4244 int cpu_rotate, task_rotate;
4248 * Since we run this from IRQ context, nobody can install new
4249 * events, thus the event count values are stable.
4252 cpu_epc = &cpc->epc;
4254 task_epc = cpc->task_epc;
4256 cpu_rotate = cpu_epc->rotate_necessary;
4257 task_rotate = task_epc ? task_epc->rotate_necessary : 0;
4259 if (!(cpu_rotate || task_rotate))
4262 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
4263 perf_pmu_disable(pmu);
4266 task_event = ctx_event_to_rotate(task_epc);
4268 cpu_event = ctx_event_to_rotate(cpu_epc);
4271 * As per the order given at ctx_resched() first 'pop' task flexible
4272 * and then, if needed CPU flexible.
4274 if (task_event || (task_epc && cpu_event)) {
4275 update_context_time(task_epc->ctx);
4276 __pmu_ctx_sched_out(task_epc, EVENT_FLEXIBLE);
4280 update_context_time(&cpuctx->ctx);
4281 __pmu_ctx_sched_out(cpu_epc, EVENT_FLEXIBLE);
4282 rotate_ctx(&cpuctx->ctx, cpu_event);
4283 __pmu_ctx_sched_in(&cpuctx->ctx, pmu);
4287 rotate_ctx(task_epc->ctx, task_event);
4289 if (task_event || (task_epc && cpu_event))
4290 __pmu_ctx_sched_in(task_epc->ctx, pmu);
4292 perf_pmu_enable(pmu);
4293 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
4298 void perf_event_task_tick(void)
4300 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
4301 struct perf_event_context *ctx;
4304 lockdep_assert_irqs_disabled();
4306 __this_cpu_inc(perf_throttled_seq);
4307 throttled = __this_cpu_xchg(perf_throttled_count, 0);
4308 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
4310 perf_adjust_freq_unthr_context(&cpuctx->ctx, !!throttled);
4313 ctx = rcu_dereference(current->perf_event_ctxp);
4315 perf_adjust_freq_unthr_context(ctx, !!throttled);
4319 static int event_enable_on_exec(struct perf_event *event,
4320 struct perf_event_context *ctx)
4322 if (!event->attr.enable_on_exec)
4325 event->attr.enable_on_exec = 0;
4326 if (event->state >= PERF_EVENT_STATE_INACTIVE)
4329 perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
4335 * Enable all of a task's events that have been marked enable-on-exec.
4336 * This expects task == current.
4338 static void perf_event_enable_on_exec(struct perf_event_context *ctx)
4340 struct perf_event_context *clone_ctx = NULL;
4341 enum event_type_t event_type = 0;
4342 struct perf_cpu_context *cpuctx;
4343 struct perf_event *event;
4344 unsigned long flags;
4347 local_irq_save(flags);
4348 if (WARN_ON_ONCE(current->perf_event_ctxp != ctx))
4351 if (!ctx->nr_events)
4354 cpuctx = this_cpu_ptr(&perf_cpu_context);
4355 perf_ctx_lock(cpuctx, ctx);
4356 ctx_sched_out(ctx, EVENT_TIME);
4358 list_for_each_entry(event, &ctx->event_list, event_entry) {
4359 enabled |= event_enable_on_exec(event, ctx);
4360 event_type |= get_event_type(event);
4364 * Unclone and reschedule this context if we enabled any event.
4367 clone_ctx = unclone_ctx(ctx);
4368 ctx_resched(cpuctx, ctx, event_type);
4370 ctx_sched_in(ctx, EVENT_TIME);
4372 perf_ctx_unlock(cpuctx, ctx);
4375 local_irq_restore(flags);
4381 static void perf_remove_from_owner(struct perf_event *event);
4382 static void perf_event_exit_event(struct perf_event *event,
4383 struct perf_event_context *ctx);
4386 * Removes all events from the current task that have been marked
4387 * remove-on-exec, and feeds their values back to parent events.
4389 static void perf_event_remove_on_exec(struct perf_event_context *ctx)
4391 struct perf_event_context *clone_ctx = NULL;
4392 struct perf_event *event, *next;
4393 unsigned long flags;
4394 bool modified = false;
4396 mutex_lock(&ctx->mutex);
4398 if (WARN_ON_ONCE(ctx->task != current))
4401 list_for_each_entry_safe(event, next, &ctx->event_list, event_entry) {
4402 if (!event->attr.remove_on_exec)
4405 if (!is_kernel_event(event))
4406 perf_remove_from_owner(event);
4410 perf_event_exit_event(event, ctx);
4413 raw_spin_lock_irqsave(&ctx->lock, flags);
4415 clone_ctx = unclone_ctx(ctx);
4416 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4419 mutex_unlock(&ctx->mutex);
4425 struct perf_read_data {
4426 struct perf_event *event;
4431 static int __perf_event_read_cpu(struct perf_event *event, int event_cpu)
4433 u16 local_pkg, event_pkg;
4435 if ((unsigned)event_cpu >= nr_cpu_ids)
4438 if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) {
4439 int local_cpu = smp_processor_id();
4441 event_pkg = topology_physical_package_id(event_cpu);
4442 local_pkg = topology_physical_package_id(local_cpu);
4444 if (event_pkg == local_pkg)
4452 * Cross CPU call to read the hardware event
4454 static void __perf_event_read(void *info)
4456 struct perf_read_data *data = info;
4457 struct perf_event *sub, *event = data->event;
4458 struct perf_event_context *ctx = event->ctx;
4459 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
4460 struct pmu *pmu = event->pmu;
4463 * If this is a task context, we need to check whether it is
4464 * the current task context of this cpu. If not it has been
4465 * scheduled out before the smp call arrived. In that case
4466 * event->count would have been updated to a recent sample
4467 * when the event was scheduled out.
4469 if (ctx->task && cpuctx->task_ctx != ctx)
4472 raw_spin_lock(&ctx->lock);
4473 if (ctx->is_active & EVENT_TIME) {
4474 update_context_time(ctx);
4475 update_cgrp_time_from_event(event);
4478 perf_event_update_time(event);
4480 perf_event_update_sibling_time(event);
4482 if (event->state != PERF_EVENT_STATE_ACTIVE)
4491 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
4495 for_each_sibling_event(sub, event) {
4496 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
4498 * Use sibling's PMU rather than @event's since
4499 * sibling could be on different (eg: software) PMU.
4501 sub->pmu->read(sub);
4505 data->ret = pmu->commit_txn(pmu);
4508 raw_spin_unlock(&ctx->lock);
4511 static inline u64 perf_event_count(struct perf_event *event)
4513 return local64_read(&event->count) + atomic64_read(&event->child_count);
4516 static void calc_timer_values(struct perf_event *event,
4523 *now = perf_clock();
4524 ctx_time = perf_event_time_now(event, *now);
4525 __perf_update_times(event, ctx_time, enabled, running);
4529 * NMI-safe method to read a local event, that is an event that
4531 * - either for the current task, or for this CPU
4532 * - does not have inherit set, for inherited task events
4533 * will not be local and we cannot read them atomically
4534 * - must not have a pmu::count method
4536 int perf_event_read_local(struct perf_event *event, u64 *value,
4537 u64 *enabled, u64 *running)
4539 unsigned long flags;
4545 * Disabling interrupts avoids all counter scheduling (context
4546 * switches, timer based rotation and IPIs).
4548 local_irq_save(flags);
4551 * It must not be an event with inherit set, we cannot read
4552 * all child counters from atomic context.
4554 if (event->attr.inherit) {
4559 /* If this is a per-task event, it must be for current */
4560 if ((event->attach_state & PERF_ATTACH_TASK) &&
4561 event->hw.target != current) {
4567 * Get the event CPU numbers, and adjust them to local if the event is
4568 * a per-package event that can be read locally
4570 event_oncpu = __perf_event_read_cpu(event, event->oncpu);
4571 event_cpu = __perf_event_read_cpu(event, event->cpu);
4573 /* If this is a per-CPU event, it must be for this CPU */
4574 if (!(event->attach_state & PERF_ATTACH_TASK) &&
4575 event_cpu != smp_processor_id()) {
4580 /* If this is a pinned event it must be running on this CPU */
4581 if (event->attr.pinned && event_oncpu != smp_processor_id()) {
4587 * If the event is currently on this CPU, its either a per-task event,
4588 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
4591 if (event_oncpu == smp_processor_id())
4592 event->pmu->read(event);
4594 *value = local64_read(&event->count);
4595 if (enabled || running) {
4596 u64 __enabled, __running, __now;
4598 calc_timer_values(event, &__now, &__enabled, &__running);
4600 *enabled = __enabled;
4602 *running = __running;
4605 local_irq_restore(flags);
4610 static int perf_event_read(struct perf_event *event, bool group)
4612 enum perf_event_state state = READ_ONCE(event->state);
4613 int event_cpu, ret = 0;
4616 * If event is enabled and currently active on a CPU, update the
4617 * value in the event structure:
4620 if (state == PERF_EVENT_STATE_ACTIVE) {
4621 struct perf_read_data data;
4624 * Orders the ->state and ->oncpu loads such that if we see
4625 * ACTIVE we must also see the right ->oncpu.
4627 * Matches the smp_wmb() from event_sched_in().
4631 event_cpu = READ_ONCE(event->oncpu);
4632 if ((unsigned)event_cpu >= nr_cpu_ids)
4635 data = (struct perf_read_data){
4642 event_cpu = __perf_event_read_cpu(event, event_cpu);
4645 * Purposely ignore the smp_call_function_single() return
4648 * If event_cpu isn't a valid CPU it means the event got
4649 * scheduled out and that will have updated the event count.
4651 * Therefore, either way, we'll have an up-to-date event count
4654 (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1);
4658 } else if (state == PERF_EVENT_STATE_INACTIVE) {
4659 struct perf_event_context *ctx = event->ctx;
4660 unsigned long flags;
4662 raw_spin_lock_irqsave(&ctx->lock, flags);
4663 state = event->state;
4664 if (state != PERF_EVENT_STATE_INACTIVE) {
4665 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4670 * May read while context is not active (e.g., thread is
4671 * blocked), in that case we cannot update context time
4673 if (ctx->is_active & EVENT_TIME) {
4674 update_context_time(ctx);
4675 update_cgrp_time_from_event(event);
4678 perf_event_update_time(event);
4680 perf_event_update_sibling_time(event);
4681 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4688 * Initialize the perf_event context in a task_struct:
4690 static void __perf_event_init_context(struct perf_event_context *ctx)
4692 raw_spin_lock_init(&ctx->lock);
4693 mutex_init(&ctx->mutex);
4694 INIT_LIST_HEAD(&ctx->pmu_ctx_list);
4695 perf_event_groups_init(&ctx->pinned_groups);
4696 perf_event_groups_init(&ctx->flexible_groups);
4697 INIT_LIST_HEAD(&ctx->event_list);
4698 refcount_set(&ctx->refcount, 1);
4702 __perf_init_event_pmu_context(struct perf_event_pmu_context *epc, struct pmu *pmu)
4705 INIT_LIST_HEAD(&epc->pmu_ctx_entry);
4706 INIT_LIST_HEAD(&epc->pinned_active);
4707 INIT_LIST_HEAD(&epc->flexible_active);
4708 atomic_set(&epc->refcount, 1);
4711 static struct perf_event_context *
4712 alloc_perf_context(struct task_struct *task)
4714 struct perf_event_context *ctx;
4716 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
4720 __perf_event_init_context(ctx);
4722 ctx->task = get_task_struct(task);
4727 static struct task_struct *
4728 find_lively_task_by_vpid(pid_t vpid)
4730 struct task_struct *task;
4736 task = find_task_by_vpid(vpid);
4738 get_task_struct(task);
4742 return ERR_PTR(-ESRCH);
4748 * Returns a matching context with refcount and pincount.
4750 static struct perf_event_context *
4751 find_get_context(struct task_struct *task, struct perf_event *event)
4753 struct perf_event_context *ctx, *clone_ctx = NULL;
4754 struct perf_cpu_context *cpuctx;
4755 unsigned long flags;
4759 /* Must be root to operate on a CPU event: */
4760 err = perf_allow_cpu(&event->attr);
4762 return ERR_PTR(err);
4764 cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu);
4767 raw_spin_lock_irqsave(&ctx->lock, flags);
4769 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4776 ctx = perf_lock_task_context(task, &flags);
4778 clone_ctx = unclone_ctx(ctx);
4781 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4786 ctx = alloc_perf_context(task);
4792 mutex_lock(&task->perf_event_mutex);
4794 * If it has already passed perf_event_exit_task().
4795 * we must see PF_EXITING, it takes this mutex too.
4797 if (task->flags & PF_EXITING)
4799 else if (task->perf_event_ctxp)
4804 rcu_assign_pointer(task->perf_event_ctxp, ctx);
4806 mutex_unlock(&task->perf_event_mutex);
4808 if (unlikely(err)) {
4820 return ERR_PTR(err);
4823 static struct perf_event_pmu_context *
4824 find_get_pmu_context(struct pmu *pmu, struct perf_event_context *ctx,
4825 struct perf_event *event)
4827 struct perf_event_pmu_context *new = NULL, *epc;
4828 void *task_ctx_data = NULL;
4832 * perf_pmu_migrate_context() / __perf_pmu_install_event()
4833 * relies on the fact that find_get_pmu_context() cannot fail
4836 struct perf_cpu_pmu_context *cpc;
4838 cpc = per_cpu_ptr(pmu->cpu_pmu_context, event->cpu);
4840 raw_spin_lock_irq(&ctx->lock);
4842 atomic_set(&epc->refcount, 1);
4844 list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
4847 WARN_ON_ONCE(epc->ctx != ctx);
4848 atomic_inc(&epc->refcount);
4850 raw_spin_unlock_irq(&ctx->lock);
4854 new = kzalloc(sizeof(*epc), GFP_KERNEL);
4856 return ERR_PTR(-ENOMEM);
4858 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
4859 task_ctx_data = alloc_task_ctx_data(pmu);
4860 if (!task_ctx_data) {
4862 return ERR_PTR(-ENOMEM);
4866 __perf_init_event_pmu_context(new, pmu);
4871 * lockdep_assert_held(&ctx->mutex);
4873 * can't because perf_event_init_task() doesn't actually hold the
4877 raw_spin_lock_irq(&ctx->lock);
4878 list_for_each_entry(epc, &ctx->pmu_ctx_list, pmu_ctx_entry) {
4879 if (epc->pmu == pmu) {
4880 WARN_ON_ONCE(epc->ctx != ctx);
4881 atomic_inc(&epc->refcount);
4889 list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
4893 if (task_ctx_data && !epc->task_ctx_data) {
4894 epc->task_ctx_data = task_ctx_data;
4895 task_ctx_data = NULL;
4896 ctx->nr_task_data++;
4898 raw_spin_unlock_irq(&ctx->lock);
4900 free_task_ctx_data(pmu, task_ctx_data);
4906 static void get_pmu_ctx(struct perf_event_pmu_context *epc)
4908 WARN_ON_ONCE(!atomic_inc_not_zero(&epc->refcount));
4911 static void free_epc_rcu(struct rcu_head *head)
4913 struct perf_event_pmu_context *epc = container_of(head, typeof(*epc), rcu_head);
4915 kfree(epc->task_ctx_data);
4919 static void put_pmu_ctx(struct perf_event_pmu_context *epc)
4921 struct perf_event_context *ctx = epc->ctx;
4922 unsigned long flags;
4927 * lockdep_assert_held(&ctx->mutex);
4929 * can't because of the call-site in _free_event()/put_event()
4930 * which isn't always called under ctx->mutex.
4932 if (!atomic_dec_and_raw_lock_irqsave(&epc->refcount, &ctx->lock, flags))
4935 WARN_ON_ONCE(list_empty(&epc->pmu_ctx_entry));
4937 list_del_init(&epc->pmu_ctx_entry);
4940 WARN_ON_ONCE(!list_empty(&epc->pinned_active));
4941 WARN_ON_ONCE(!list_empty(&epc->flexible_active));
4943 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4948 call_rcu(&epc->rcu_head, free_epc_rcu);
4951 static void perf_event_free_filter(struct perf_event *event);
4953 static void free_event_rcu(struct rcu_head *head)
4955 struct perf_event *event = container_of(head, typeof(*event), rcu_head);
4958 put_pid_ns(event->ns);
4959 perf_event_free_filter(event);
4960 kmem_cache_free(perf_event_cache, event);
4963 static void ring_buffer_attach(struct perf_event *event,
4964 struct perf_buffer *rb);
4966 static void detach_sb_event(struct perf_event *event)
4968 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
4970 raw_spin_lock(&pel->lock);
4971 list_del_rcu(&event->sb_list);
4972 raw_spin_unlock(&pel->lock);
4975 static bool is_sb_event(struct perf_event *event)
4977 struct perf_event_attr *attr = &event->attr;
4982 if (event->attach_state & PERF_ATTACH_TASK)
4985 if (attr->mmap || attr->mmap_data || attr->mmap2 ||
4986 attr->comm || attr->comm_exec ||
4987 attr->task || attr->ksymbol ||
4988 attr->context_switch || attr->text_poke ||
4994 static void unaccount_pmu_sb_event(struct perf_event *event)
4996 if (is_sb_event(event))
4997 detach_sb_event(event);
5000 #ifdef CONFIG_NO_HZ_FULL
5001 static DEFINE_SPINLOCK(nr_freq_lock);
5004 static void unaccount_freq_event_nohz(void)
5006 #ifdef CONFIG_NO_HZ_FULL
5007 spin_lock(&nr_freq_lock);
5008 if (atomic_dec_and_test(&nr_freq_events))
5009 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
5010 spin_unlock(&nr_freq_lock);
5014 static void unaccount_freq_event(void)
5016 if (tick_nohz_full_enabled())
5017 unaccount_freq_event_nohz();
5019 atomic_dec(&nr_freq_events);
5022 static void unaccount_event(struct perf_event *event)
5029 if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
5031 if (event->attr.mmap || event->attr.mmap_data)
5032 atomic_dec(&nr_mmap_events);
5033 if (event->attr.build_id)
5034 atomic_dec(&nr_build_id_events);
5035 if (event->attr.comm)
5036 atomic_dec(&nr_comm_events);
5037 if (event->attr.namespaces)
5038 atomic_dec(&nr_namespaces_events);
5039 if (event->attr.cgroup)
5040 atomic_dec(&nr_cgroup_events);
5041 if (event->attr.task)
5042 atomic_dec(&nr_task_events);
5043 if (event->attr.freq)
5044 unaccount_freq_event();
5045 if (event->attr.context_switch) {
5047 atomic_dec(&nr_switch_events);
5049 if (is_cgroup_event(event))
5051 if (has_branch_stack(event))
5053 if (event->attr.ksymbol)
5054 atomic_dec(&nr_ksymbol_events);
5055 if (event->attr.bpf_event)
5056 atomic_dec(&nr_bpf_events);
5057 if (event->attr.text_poke)
5058 atomic_dec(&nr_text_poke_events);
5061 if (!atomic_add_unless(&perf_sched_count, -1, 1))
5062 schedule_delayed_work(&perf_sched_work, HZ);
5065 unaccount_pmu_sb_event(event);
5068 static void perf_sched_delayed(struct work_struct *work)
5070 mutex_lock(&perf_sched_mutex);
5071 if (atomic_dec_and_test(&perf_sched_count))
5072 static_branch_disable(&perf_sched_events);
5073 mutex_unlock(&perf_sched_mutex);
5077 * The following implement mutual exclusion of events on "exclusive" pmus
5078 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
5079 * at a time, so we disallow creating events that might conflict, namely:
5081 * 1) cpu-wide events in the presence of per-task events,
5082 * 2) per-task events in the presence of cpu-wide events,
5083 * 3) two matching events on the same perf_event_context.
5085 * The former two cases are handled in the allocation path (perf_event_alloc(),
5086 * _free_event()), the latter -- before the first perf_install_in_context().
5088 static int exclusive_event_init(struct perf_event *event)
5090 struct pmu *pmu = event->pmu;
5092 if (!is_exclusive_pmu(pmu))
5096 * Prevent co-existence of per-task and cpu-wide events on the
5097 * same exclusive pmu.
5099 * Negative pmu::exclusive_cnt means there are cpu-wide
5100 * events on this "exclusive" pmu, positive means there are
5103 * Since this is called in perf_event_alloc() path, event::ctx
5104 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
5105 * to mean "per-task event", because unlike other attach states it
5106 * never gets cleared.
5108 if (event->attach_state & PERF_ATTACH_TASK) {
5109 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
5112 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
5119 static void exclusive_event_destroy(struct perf_event *event)
5121 struct pmu *pmu = event->pmu;
5123 if (!is_exclusive_pmu(pmu))
5126 /* see comment in exclusive_event_init() */
5127 if (event->attach_state & PERF_ATTACH_TASK)
5128 atomic_dec(&pmu->exclusive_cnt);
5130 atomic_inc(&pmu->exclusive_cnt);
5133 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
5135 if ((e1->pmu == e2->pmu) &&
5136 (e1->cpu == e2->cpu ||
5143 static bool exclusive_event_installable(struct perf_event *event,
5144 struct perf_event_context *ctx)
5146 struct perf_event *iter_event;
5147 struct pmu *pmu = event->pmu;
5149 lockdep_assert_held(&ctx->mutex);
5151 if (!is_exclusive_pmu(pmu))
5154 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
5155 if (exclusive_event_match(iter_event, event))
5162 static void perf_addr_filters_splice(struct perf_event *event,
5163 struct list_head *head);
5165 static void _free_event(struct perf_event *event)
5167 irq_work_sync(&event->pending_irq);
5169 unaccount_event(event);
5171 security_perf_event_free(event);
5175 * Can happen when we close an event with re-directed output.
5177 * Since we have a 0 refcount, perf_mmap_close() will skip
5178 * over us; possibly making our ring_buffer_put() the last.
5180 mutex_lock(&event->mmap_mutex);
5181 ring_buffer_attach(event, NULL);
5182 mutex_unlock(&event->mmap_mutex);
5185 if (is_cgroup_event(event))
5186 perf_detach_cgroup(event);
5188 if (!event->parent) {
5189 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
5190 put_callchain_buffers();
5193 perf_event_free_bpf_prog(event);
5194 perf_addr_filters_splice(event, NULL);
5195 kfree(event->addr_filter_ranges);
5198 event->destroy(event);
5201 * Must be after ->destroy(), due to uprobe_perf_close() using
5204 if (event->hw.target)
5205 put_task_struct(event->hw.target);
5208 put_pmu_ctx(event->pmu_ctx);
5211 * perf_event_free_task() relies on put_ctx() being 'last', in particular
5212 * all task references must be cleaned up.
5215 put_ctx(event->ctx);
5217 exclusive_event_destroy(event);
5218 module_put(event->pmu->module);
5220 call_rcu(&event->rcu_head, free_event_rcu);
5224 * Used to free events which have a known refcount of 1, such as in error paths
5225 * where the event isn't exposed yet and inherited events.
5227 static void free_event(struct perf_event *event)
5229 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
5230 "unexpected event refcount: %ld; ptr=%p\n",
5231 atomic_long_read(&event->refcount), event)) {
5232 /* leak to avoid use-after-free */
5240 * Remove user event from the owner task.
5242 static void perf_remove_from_owner(struct perf_event *event)
5244 struct task_struct *owner;
5248 * Matches the smp_store_release() in perf_event_exit_task(). If we
5249 * observe !owner it means the list deletion is complete and we can
5250 * indeed free this event, otherwise we need to serialize on
5251 * owner->perf_event_mutex.
5253 owner = READ_ONCE(event->owner);
5256 * Since delayed_put_task_struct() also drops the last
5257 * task reference we can safely take a new reference
5258 * while holding the rcu_read_lock().
5260 get_task_struct(owner);
5266 * If we're here through perf_event_exit_task() we're already
5267 * holding ctx->mutex which would be an inversion wrt. the
5268 * normal lock order.
5270 * However we can safely take this lock because its the child
5273 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
5276 * We have to re-check the event->owner field, if it is cleared
5277 * we raced with perf_event_exit_task(), acquiring the mutex
5278 * ensured they're done, and we can proceed with freeing the
5282 list_del_init(&event->owner_entry);
5283 smp_store_release(&event->owner, NULL);
5285 mutex_unlock(&owner->perf_event_mutex);
5286 put_task_struct(owner);
5290 static void put_event(struct perf_event *event)
5292 if (!atomic_long_dec_and_test(&event->refcount))
5299 * Kill an event dead; while event:refcount will preserve the event
5300 * object, it will not preserve its functionality. Once the last 'user'
5301 * gives up the object, we'll destroy the thing.
5303 int perf_event_release_kernel(struct perf_event *event)
5305 struct perf_event_context *ctx = event->ctx;
5306 struct perf_event *child, *tmp;
5307 LIST_HEAD(free_list);
5310 * If we got here through err_alloc: free_event(event); we will not
5311 * have attached to a context yet.
5314 WARN_ON_ONCE(event->attach_state &
5315 (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
5319 if (!is_kernel_event(event))
5320 perf_remove_from_owner(event);
5322 ctx = perf_event_ctx_lock(event);
5323 WARN_ON_ONCE(ctx->parent_ctx);
5326 * Mark this event as STATE_DEAD, there is no external reference to it
5329 * Anybody acquiring event->child_mutex after the below loop _must_
5330 * also see this, most importantly inherit_event() which will avoid
5331 * placing more children on the list.
5333 * Thus this guarantees that we will in fact observe and kill _ALL_
5336 perf_remove_from_context(event, DETACH_GROUP|DETACH_DEAD);
5338 perf_event_ctx_unlock(event, ctx);
5341 mutex_lock(&event->child_mutex);
5342 list_for_each_entry(child, &event->child_list, child_list) {
5345 * Cannot change, child events are not migrated, see the
5346 * comment with perf_event_ctx_lock_nested().
5348 ctx = READ_ONCE(child->ctx);
5350 * Since child_mutex nests inside ctx::mutex, we must jump
5351 * through hoops. We start by grabbing a reference on the ctx.
5353 * Since the event cannot get freed while we hold the
5354 * child_mutex, the context must also exist and have a !0
5360 * Now that we have a ctx ref, we can drop child_mutex, and
5361 * acquire ctx::mutex without fear of it going away. Then we
5362 * can re-acquire child_mutex.
5364 mutex_unlock(&event->child_mutex);
5365 mutex_lock(&ctx->mutex);
5366 mutex_lock(&event->child_mutex);
5369 * Now that we hold ctx::mutex and child_mutex, revalidate our
5370 * state, if child is still the first entry, it didn't get freed
5371 * and we can continue doing so.
5373 tmp = list_first_entry_or_null(&event->child_list,
5374 struct perf_event, child_list);
5376 perf_remove_from_context(child, DETACH_GROUP);
5377 list_move(&child->child_list, &free_list);
5379 * This matches the refcount bump in inherit_event();
5380 * this can't be the last reference.
5385 mutex_unlock(&event->child_mutex);
5386 mutex_unlock(&ctx->mutex);
5390 mutex_unlock(&event->child_mutex);
5392 list_for_each_entry_safe(child, tmp, &free_list, child_list) {
5393 void *var = &child->ctx->refcount;
5395 list_del(&child->child_list);
5399 * Wake any perf_event_free_task() waiting for this event to be
5402 smp_mb(); /* pairs with wait_var_event() */
5407 put_event(event); /* Must be the 'last' reference */
5410 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
5413 * Called when the last reference to the file is gone.
5415 static int perf_release(struct inode *inode, struct file *file)
5417 perf_event_release_kernel(file->private_data);
5421 static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
5423 struct perf_event *child;
5429 mutex_lock(&event->child_mutex);
5431 (void)perf_event_read(event, false);
5432 total += perf_event_count(event);
5434 *enabled += event->total_time_enabled +
5435 atomic64_read(&event->child_total_time_enabled);
5436 *running += event->total_time_running +
5437 atomic64_read(&event->child_total_time_running);
5439 list_for_each_entry(child, &event->child_list, child_list) {
5440 (void)perf_event_read(child, false);
5441 total += perf_event_count(child);
5442 *enabled += child->total_time_enabled;
5443 *running += child->total_time_running;
5445 mutex_unlock(&event->child_mutex);
5450 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
5452 struct perf_event_context *ctx;
5455 ctx = perf_event_ctx_lock(event);
5456 count = __perf_event_read_value(event, enabled, running);
5457 perf_event_ctx_unlock(event, ctx);
5461 EXPORT_SYMBOL_GPL(perf_event_read_value);
5463 static int __perf_read_group_add(struct perf_event *leader,
5464 u64 read_format, u64 *values)
5466 struct perf_event_context *ctx = leader->ctx;
5467 struct perf_event *sub, *parent;
5468 unsigned long flags;
5469 int n = 1; /* skip @nr */
5472 ret = perf_event_read(leader, true);
5476 raw_spin_lock_irqsave(&ctx->lock, flags);
5478 * Verify the grouping between the parent and child (inherited)
5479 * events is still in tact.
5482 * - leader->ctx->lock pins leader->sibling_list
5483 * - parent->child_mutex pins parent->child_list
5484 * - parent->ctx->mutex pins parent->sibling_list
5486 * Because parent->ctx != leader->ctx (and child_list nests inside
5487 * ctx->mutex), group destruction is not atomic between children, also
5488 * see perf_event_release_kernel(). Additionally, parent can grow the
5491 * Therefore it is possible to have parent and child groups in a
5492 * different configuration and summing over such a beast makes no sense
5497 parent = leader->parent;
5499 (parent->group_generation != leader->group_generation ||
5500 parent->nr_siblings != leader->nr_siblings)) {
5506 * Since we co-schedule groups, {enabled,running} times of siblings
5507 * will be identical to those of the leader, so we only publish one
5510 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5511 values[n++] += leader->total_time_enabled +
5512 atomic64_read(&leader->child_total_time_enabled);
5515 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5516 values[n++] += leader->total_time_running +
5517 atomic64_read(&leader->child_total_time_running);
5521 * Write {count,id} tuples for every sibling.
5523 values[n++] += perf_event_count(leader);
5524 if (read_format & PERF_FORMAT_ID)
5525 values[n++] = primary_event_id(leader);
5526 if (read_format & PERF_FORMAT_LOST)
5527 values[n++] = atomic64_read(&leader->lost_samples);
5529 for_each_sibling_event(sub, leader) {
5530 values[n++] += perf_event_count(sub);
5531 if (read_format & PERF_FORMAT_ID)
5532 values[n++] = primary_event_id(sub);
5533 if (read_format & PERF_FORMAT_LOST)
5534 values[n++] = atomic64_read(&sub->lost_samples);
5538 raw_spin_unlock_irqrestore(&ctx->lock, flags);
5542 static int perf_read_group(struct perf_event *event,
5543 u64 read_format, char __user *buf)
5545 struct perf_event *leader = event->group_leader, *child;
5546 struct perf_event_context *ctx = leader->ctx;
5550 lockdep_assert_held(&ctx->mutex);
5552 values = kzalloc(event->read_size, GFP_KERNEL);
5556 values[0] = 1 + leader->nr_siblings;
5558 mutex_lock(&leader->child_mutex);
5560 ret = __perf_read_group_add(leader, read_format, values);
5564 list_for_each_entry(child, &leader->child_list, child_list) {
5565 ret = __perf_read_group_add(child, read_format, values);
5570 mutex_unlock(&leader->child_mutex);
5572 ret = event->read_size;
5573 if (copy_to_user(buf, values, event->read_size))
5578 mutex_unlock(&leader->child_mutex);
5584 static int perf_read_one(struct perf_event *event,
5585 u64 read_format, char __user *buf)
5587 u64 enabled, running;
5591 values[n++] = __perf_event_read_value(event, &enabled, &running);
5592 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5593 values[n++] = enabled;
5594 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5595 values[n++] = running;
5596 if (read_format & PERF_FORMAT_ID)
5597 values[n++] = primary_event_id(event);
5598 if (read_format & PERF_FORMAT_LOST)
5599 values[n++] = atomic64_read(&event->lost_samples);
5601 if (copy_to_user(buf, values, n * sizeof(u64)))
5604 return n * sizeof(u64);
5607 static bool is_event_hup(struct perf_event *event)
5611 if (event->state > PERF_EVENT_STATE_EXIT)
5614 mutex_lock(&event->child_mutex);
5615 no_children = list_empty(&event->child_list);
5616 mutex_unlock(&event->child_mutex);
5621 * Read the performance event - simple non blocking version for now
5624 __perf_read(struct perf_event *event, char __user *buf, size_t count)
5626 u64 read_format = event->attr.read_format;
5630 * Return end-of-file for a read on an event that is in
5631 * error state (i.e. because it was pinned but it couldn't be
5632 * scheduled on to the CPU at some point).
5634 if (event->state == PERF_EVENT_STATE_ERROR)
5637 if (count < event->read_size)
5640 WARN_ON_ONCE(event->ctx->parent_ctx);
5641 if (read_format & PERF_FORMAT_GROUP)
5642 ret = perf_read_group(event, read_format, buf);
5644 ret = perf_read_one(event, read_format, buf);
5650 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
5652 struct perf_event *event = file->private_data;
5653 struct perf_event_context *ctx;
5656 ret = security_perf_event_read(event);
5660 ctx = perf_event_ctx_lock(event);
5661 ret = __perf_read(event, buf, count);
5662 perf_event_ctx_unlock(event, ctx);
5667 static __poll_t perf_poll(struct file *file, poll_table *wait)
5669 struct perf_event *event = file->private_data;
5670 struct perf_buffer *rb;
5671 __poll_t events = EPOLLHUP;
5673 poll_wait(file, &event->waitq, wait);
5675 if (is_event_hup(event))
5679 * Pin the event->rb by taking event->mmap_mutex; otherwise
5680 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
5682 mutex_lock(&event->mmap_mutex);
5685 events = atomic_xchg(&rb->poll, 0);
5686 mutex_unlock(&event->mmap_mutex);
5690 static void _perf_event_reset(struct perf_event *event)
5692 (void)perf_event_read(event, false);
5693 local64_set(&event->count, 0);
5694 perf_event_update_userpage(event);
5697 /* Assume it's not an event with inherit set. */
5698 u64 perf_event_pause(struct perf_event *event, bool reset)
5700 struct perf_event_context *ctx;
5703 ctx = perf_event_ctx_lock(event);
5704 WARN_ON_ONCE(event->attr.inherit);
5705 _perf_event_disable(event);
5706 count = local64_read(&event->count);
5708 local64_set(&event->count, 0);
5709 perf_event_ctx_unlock(event, ctx);
5713 EXPORT_SYMBOL_GPL(perf_event_pause);
5716 * Holding the top-level event's child_mutex means that any
5717 * descendant process that has inherited this event will block
5718 * in perf_event_exit_event() if it goes to exit, thus satisfying the
5719 * task existence requirements of perf_event_enable/disable.
5721 static void perf_event_for_each_child(struct perf_event *event,
5722 void (*func)(struct perf_event *))
5724 struct perf_event *child;
5726 WARN_ON_ONCE(event->ctx->parent_ctx);
5728 mutex_lock(&event->child_mutex);
5730 list_for_each_entry(child, &event->child_list, child_list)
5732 mutex_unlock(&event->child_mutex);
5735 static void perf_event_for_each(struct perf_event *event,
5736 void (*func)(struct perf_event *))
5738 struct perf_event_context *ctx = event->ctx;
5739 struct perf_event *sibling;
5741 lockdep_assert_held(&ctx->mutex);
5743 event = event->group_leader;
5745 perf_event_for_each_child(event, func);
5746 for_each_sibling_event(sibling, event)
5747 perf_event_for_each_child(sibling, func);
5750 static void __perf_event_period(struct perf_event *event,
5751 struct perf_cpu_context *cpuctx,
5752 struct perf_event_context *ctx,
5755 u64 value = *((u64 *)info);
5758 if (event->attr.freq) {
5759 event->attr.sample_freq = value;
5761 event->attr.sample_period = value;
5762 event->hw.sample_period = value;
5765 active = (event->state == PERF_EVENT_STATE_ACTIVE);
5767 perf_pmu_disable(event->pmu);
5769 * We could be throttled; unthrottle now to avoid the tick
5770 * trying to unthrottle while we already re-started the event.
5772 if (event->hw.interrupts == MAX_INTERRUPTS) {
5773 event->hw.interrupts = 0;
5774 perf_log_throttle(event, 1);
5776 event->pmu->stop(event, PERF_EF_UPDATE);
5779 local64_set(&event->hw.period_left, 0);
5782 event->pmu->start(event, PERF_EF_RELOAD);
5783 perf_pmu_enable(event->pmu);
5787 static int perf_event_check_period(struct perf_event *event, u64 value)
5789 return event->pmu->check_period(event, value);
5792 static int _perf_event_period(struct perf_event *event, u64 value)
5794 if (!is_sampling_event(event))
5800 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
5803 if (perf_event_check_period(event, value))
5806 if (!event->attr.freq && (value & (1ULL << 63)))
5809 event_function_call(event, __perf_event_period, &value);
5814 int perf_event_period(struct perf_event *event, u64 value)
5816 struct perf_event_context *ctx;
5819 ctx = perf_event_ctx_lock(event);
5820 ret = _perf_event_period(event, value);
5821 perf_event_ctx_unlock(event, ctx);
5825 EXPORT_SYMBOL_GPL(perf_event_period);
5827 static const struct file_operations perf_fops;
5829 static inline int perf_fget_light(int fd, struct fd *p)
5831 struct fd f = fdget(fd);
5835 if (f.file->f_op != &perf_fops) {
5843 static int perf_event_set_output(struct perf_event *event,
5844 struct perf_event *output_event);
5845 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
5846 static int perf_copy_attr(struct perf_event_attr __user *uattr,
5847 struct perf_event_attr *attr);
5849 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
5851 void (*func)(struct perf_event *);
5855 case PERF_EVENT_IOC_ENABLE:
5856 func = _perf_event_enable;
5858 case PERF_EVENT_IOC_DISABLE:
5859 func = _perf_event_disable;
5861 case PERF_EVENT_IOC_RESET:
5862 func = _perf_event_reset;
5865 case PERF_EVENT_IOC_REFRESH:
5866 return _perf_event_refresh(event, arg);
5868 case PERF_EVENT_IOC_PERIOD:
5872 if (copy_from_user(&value, (u64 __user *)arg, sizeof(value)))
5875 return _perf_event_period(event, value);
5877 case PERF_EVENT_IOC_ID:
5879 u64 id = primary_event_id(event);
5881 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
5886 case PERF_EVENT_IOC_SET_OUTPUT:
5890 struct perf_event *output_event;
5892 ret = perf_fget_light(arg, &output);
5895 output_event = output.file->private_data;
5896 ret = perf_event_set_output(event, output_event);
5899 ret = perf_event_set_output(event, NULL);
5904 case PERF_EVENT_IOC_SET_FILTER:
5905 return perf_event_set_filter(event, (void __user *)arg);
5907 case PERF_EVENT_IOC_SET_BPF:
5909 struct bpf_prog *prog;
5912 prog = bpf_prog_get(arg);
5914 return PTR_ERR(prog);
5916 err = perf_event_set_bpf_prog(event, prog, 0);
5925 case PERF_EVENT_IOC_PAUSE_OUTPUT: {
5926 struct perf_buffer *rb;
5929 rb = rcu_dereference(event->rb);
5930 if (!rb || !rb->nr_pages) {
5934 rb_toggle_paused(rb, !!arg);
5939 case PERF_EVENT_IOC_QUERY_BPF:
5940 return perf_event_query_prog_array(event, (void __user *)arg);
5942 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES: {
5943 struct perf_event_attr new_attr;
5944 int err = perf_copy_attr((struct perf_event_attr __user *)arg,
5950 return perf_event_modify_attr(event, &new_attr);
5956 if (flags & PERF_IOC_FLAG_GROUP)
5957 perf_event_for_each(event, func);
5959 perf_event_for_each_child(event, func);
5964 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5966 struct perf_event *event = file->private_data;
5967 struct perf_event_context *ctx;
5970 /* Treat ioctl like writes as it is likely a mutating operation. */
5971 ret = security_perf_event_write(event);
5975 ctx = perf_event_ctx_lock(event);
5976 ret = _perf_ioctl(event, cmd, arg);
5977 perf_event_ctx_unlock(event, ctx);
5982 #ifdef CONFIG_COMPAT
5983 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
5986 switch (_IOC_NR(cmd)) {
5987 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
5988 case _IOC_NR(PERF_EVENT_IOC_ID):
5989 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF):
5990 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES):
5991 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5992 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
5993 cmd &= ~IOCSIZE_MASK;
5994 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
5998 return perf_ioctl(file, cmd, arg);
6001 # define perf_compat_ioctl NULL
6004 int perf_event_task_enable(void)
6006 struct perf_event_context *ctx;
6007 struct perf_event *event;
6009 mutex_lock(¤t->perf_event_mutex);
6010 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
6011 ctx = perf_event_ctx_lock(event);
6012 perf_event_for_each_child(event, _perf_event_enable);
6013 perf_event_ctx_unlock(event, ctx);
6015 mutex_unlock(¤t->perf_event_mutex);
6020 int perf_event_task_disable(void)
6022 struct perf_event_context *ctx;
6023 struct perf_event *event;
6025 mutex_lock(¤t->perf_event_mutex);
6026 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
6027 ctx = perf_event_ctx_lock(event);
6028 perf_event_for_each_child(event, _perf_event_disable);
6029 perf_event_ctx_unlock(event, ctx);
6031 mutex_unlock(¤t->perf_event_mutex);
6036 static int perf_event_index(struct perf_event *event)
6038 if (event->hw.state & PERF_HES_STOPPED)
6041 if (event->state != PERF_EVENT_STATE_ACTIVE)
6044 return event->pmu->event_idx(event);
6047 static void perf_event_init_userpage(struct perf_event *event)
6049 struct perf_event_mmap_page *userpg;
6050 struct perf_buffer *rb;
6053 rb = rcu_dereference(event->rb);
6057 userpg = rb->user_page;
6059 /* Allow new userspace to detect that bit 0 is deprecated */
6060 userpg->cap_bit0_is_deprecated = 1;
6061 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
6062 userpg->data_offset = PAGE_SIZE;
6063 userpg->data_size = perf_data_size(rb);
6069 void __weak arch_perf_update_userpage(
6070 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
6075 * Callers need to ensure there can be no nesting of this function, otherwise
6076 * the seqlock logic goes bad. We can not serialize this because the arch
6077 * code calls this from NMI context.
6079 void perf_event_update_userpage(struct perf_event *event)
6081 struct perf_event_mmap_page *userpg;
6082 struct perf_buffer *rb;
6083 u64 enabled, running, now;
6086 rb = rcu_dereference(event->rb);
6091 * compute total_time_enabled, total_time_running
6092 * based on snapshot values taken when the event
6093 * was last scheduled in.
6095 * we cannot simply called update_context_time()
6096 * because of locking issue as we can be called in
6099 calc_timer_values(event, &now, &enabled, &running);
6101 userpg = rb->user_page;
6103 * Disable preemption to guarantee consistent time stamps are stored to
6109 userpg->index = perf_event_index(event);
6110 userpg->offset = perf_event_count(event);
6112 userpg->offset -= local64_read(&event->hw.prev_count);
6114 userpg->time_enabled = enabled +
6115 atomic64_read(&event->child_total_time_enabled);
6117 userpg->time_running = running +
6118 atomic64_read(&event->child_total_time_running);
6120 arch_perf_update_userpage(event, userpg, now);
6128 EXPORT_SYMBOL_GPL(perf_event_update_userpage);
6130 static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
6132 struct perf_event *event = vmf->vma->vm_file->private_data;
6133 struct perf_buffer *rb;
6134 vm_fault_t ret = VM_FAULT_SIGBUS;
6136 if (vmf->flags & FAULT_FLAG_MKWRITE) {
6137 if (vmf->pgoff == 0)
6143 rb = rcu_dereference(event->rb);
6147 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
6150 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
6154 get_page(vmf->page);
6155 vmf->page->mapping = vmf->vma->vm_file->f_mapping;
6156 vmf->page->index = vmf->pgoff;
6165 static void ring_buffer_attach(struct perf_event *event,
6166 struct perf_buffer *rb)
6168 struct perf_buffer *old_rb = NULL;
6169 unsigned long flags;
6171 WARN_ON_ONCE(event->parent);
6175 * Should be impossible, we set this when removing
6176 * event->rb_entry and wait/clear when adding event->rb_entry.
6178 WARN_ON_ONCE(event->rcu_pending);
6181 spin_lock_irqsave(&old_rb->event_lock, flags);
6182 list_del_rcu(&event->rb_entry);
6183 spin_unlock_irqrestore(&old_rb->event_lock, flags);
6185 event->rcu_batches = get_state_synchronize_rcu();
6186 event->rcu_pending = 1;
6190 if (event->rcu_pending) {
6191 cond_synchronize_rcu(event->rcu_batches);
6192 event->rcu_pending = 0;
6195 spin_lock_irqsave(&rb->event_lock, flags);
6196 list_add_rcu(&event->rb_entry, &rb->event_list);
6197 spin_unlock_irqrestore(&rb->event_lock, flags);
6201 * Avoid racing with perf_mmap_close(AUX): stop the event
6202 * before swizzling the event::rb pointer; if it's getting
6203 * unmapped, its aux_mmap_count will be 0 and it won't
6204 * restart. See the comment in __perf_pmu_output_stop().
6206 * Data will inevitably be lost when set_output is done in
6207 * mid-air, but then again, whoever does it like this is
6208 * not in for the data anyway.
6211 perf_event_stop(event, 0);
6213 rcu_assign_pointer(event->rb, rb);
6216 ring_buffer_put(old_rb);
6218 * Since we detached before setting the new rb, so that we
6219 * could attach the new rb, we could have missed a wakeup.
6222 wake_up_all(&event->waitq);
6226 static void ring_buffer_wakeup(struct perf_event *event)
6228 struct perf_buffer *rb;
6231 event = event->parent;
6234 rb = rcu_dereference(event->rb);
6236 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
6237 wake_up_all(&event->waitq);
6242 struct perf_buffer *ring_buffer_get(struct perf_event *event)
6244 struct perf_buffer *rb;
6247 event = event->parent;
6250 rb = rcu_dereference(event->rb);
6252 if (!refcount_inc_not_zero(&rb->refcount))
6260 void ring_buffer_put(struct perf_buffer *rb)
6262 if (!refcount_dec_and_test(&rb->refcount))
6265 WARN_ON_ONCE(!list_empty(&rb->event_list));
6267 call_rcu(&rb->rcu_head, rb_free_rcu);
6270 static void perf_mmap_open(struct vm_area_struct *vma)
6272 struct perf_event *event = vma->vm_file->private_data;
6274 atomic_inc(&event->mmap_count);
6275 atomic_inc(&event->rb->mmap_count);
6278 atomic_inc(&event->rb->aux_mmap_count);
6280 if (event->pmu->event_mapped)
6281 event->pmu->event_mapped(event, vma->vm_mm);
6284 static void perf_pmu_output_stop(struct perf_event *event);
6287 * A buffer can be mmap()ed multiple times; either directly through the same
6288 * event, or through other events by use of perf_event_set_output().
6290 * In order to undo the VM accounting done by perf_mmap() we need to destroy
6291 * the buffer here, where we still have a VM context. This means we need
6292 * to detach all events redirecting to us.
6294 static void perf_mmap_close(struct vm_area_struct *vma)
6296 struct perf_event *event = vma->vm_file->private_data;
6297 struct perf_buffer *rb = ring_buffer_get(event);
6298 struct user_struct *mmap_user = rb->mmap_user;
6299 int mmap_locked = rb->mmap_locked;
6300 unsigned long size = perf_data_size(rb);
6301 bool detach_rest = false;
6303 if (event->pmu->event_unmapped)
6304 event->pmu->event_unmapped(event, vma->vm_mm);
6307 * rb->aux_mmap_count will always drop before rb->mmap_count and
6308 * event->mmap_count, so it is ok to use event->mmap_mutex to
6309 * serialize with perf_mmap here.
6311 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
6312 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
6314 * Stop all AUX events that are writing to this buffer,
6315 * so that we can free its AUX pages and corresponding PMU
6316 * data. Note that after rb::aux_mmap_count dropped to zero,
6317 * they won't start any more (see perf_aux_output_begin()).
6319 perf_pmu_output_stop(event);
6321 /* now it's safe to free the pages */
6322 atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->locked_vm);
6323 atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm);
6325 /* this has to be the last one */
6327 WARN_ON_ONCE(refcount_read(&rb->aux_refcount));
6329 mutex_unlock(&event->mmap_mutex);
6332 if (atomic_dec_and_test(&rb->mmap_count))
6335 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
6338 ring_buffer_attach(event, NULL);
6339 mutex_unlock(&event->mmap_mutex);
6341 /* If there's still other mmap()s of this buffer, we're done. */
6346 * No other mmap()s, detach from all other events that might redirect
6347 * into the now unreachable buffer. Somewhat complicated by the
6348 * fact that rb::event_lock otherwise nests inside mmap_mutex.
6352 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
6353 if (!atomic_long_inc_not_zero(&event->refcount)) {
6355 * This event is en-route to free_event() which will
6356 * detach it and remove it from the list.
6362 mutex_lock(&event->mmap_mutex);
6364 * Check we didn't race with perf_event_set_output() which can
6365 * swizzle the rb from under us while we were waiting to
6366 * acquire mmap_mutex.
6368 * If we find a different rb; ignore this event, a next
6369 * iteration will no longer find it on the list. We have to
6370 * still restart the iteration to make sure we're not now
6371 * iterating the wrong list.
6373 if (event->rb == rb)
6374 ring_buffer_attach(event, NULL);
6376 mutex_unlock(&event->mmap_mutex);
6380 * Restart the iteration; either we're on the wrong list or
6381 * destroyed its integrity by doing a deletion.
6388 * It could be there's still a few 0-ref events on the list; they'll
6389 * get cleaned up by free_event() -- they'll also still have their
6390 * ref on the rb and will free it whenever they are done with it.
6392 * Aside from that, this buffer is 'fully' detached and unmapped,
6393 * undo the VM accounting.
6396 atomic_long_sub((size >> PAGE_SHIFT) + 1 - mmap_locked,
6397 &mmap_user->locked_vm);
6398 atomic64_sub(mmap_locked, &vma->vm_mm->pinned_vm);
6399 free_uid(mmap_user);
6402 ring_buffer_put(rb); /* could be last */
6405 static const struct vm_operations_struct perf_mmap_vmops = {
6406 .open = perf_mmap_open,
6407 .close = perf_mmap_close, /* non mergeable */
6408 .fault = perf_mmap_fault,
6409 .page_mkwrite = perf_mmap_fault,
6412 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
6414 struct perf_event *event = file->private_data;
6415 unsigned long user_locked, user_lock_limit;
6416 struct user_struct *user = current_user();
6417 struct perf_buffer *rb = NULL;
6418 unsigned long locked, lock_limit;
6419 unsigned long vma_size;
6420 unsigned long nr_pages;
6421 long user_extra = 0, extra = 0;
6422 int ret = 0, flags = 0;
6425 * Don't allow mmap() of inherited per-task counters. This would
6426 * create a performance issue due to all children writing to the
6429 if (event->cpu == -1 && event->attr.inherit)
6432 if (!(vma->vm_flags & VM_SHARED))
6435 ret = security_perf_event_read(event);
6439 vma_size = vma->vm_end - vma->vm_start;
6441 if (vma->vm_pgoff == 0) {
6442 nr_pages = (vma_size / PAGE_SIZE) - 1;
6445 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
6446 * mapped, all subsequent mappings should have the same size
6447 * and offset. Must be above the normal perf buffer.
6449 u64 aux_offset, aux_size;
6454 nr_pages = vma_size / PAGE_SIZE;
6456 mutex_lock(&event->mmap_mutex);
6463 aux_offset = READ_ONCE(rb->user_page->aux_offset);
6464 aux_size = READ_ONCE(rb->user_page->aux_size);
6466 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
6469 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
6472 /* already mapped with a different offset */
6473 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
6476 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
6479 /* already mapped with a different size */
6480 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
6483 if (!is_power_of_2(nr_pages))
6486 if (!atomic_inc_not_zero(&rb->mmap_count))
6489 if (rb_has_aux(rb)) {
6490 atomic_inc(&rb->aux_mmap_count);
6495 atomic_set(&rb->aux_mmap_count, 1);
6496 user_extra = nr_pages;
6502 * If we have rb pages ensure they're a power-of-two number, so we
6503 * can do bitmasks instead of modulo.
6505 if (nr_pages != 0 && !is_power_of_2(nr_pages))
6508 if (vma_size != PAGE_SIZE * (1 + nr_pages))
6511 WARN_ON_ONCE(event->ctx->parent_ctx);
6513 mutex_lock(&event->mmap_mutex);
6515 if (data_page_nr(event->rb) != nr_pages) {
6520 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
6522 * Raced against perf_mmap_close(); remove the
6523 * event and try again.
6525 ring_buffer_attach(event, NULL);
6526 mutex_unlock(&event->mmap_mutex);
6533 user_extra = nr_pages + 1;
6536 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
6539 * Increase the limit linearly with more CPUs:
6541 user_lock_limit *= num_online_cpus();
6543 user_locked = atomic_long_read(&user->locked_vm);
6546 * sysctl_perf_event_mlock may have changed, so that
6547 * user->locked_vm > user_lock_limit
6549 if (user_locked > user_lock_limit)
6550 user_locked = user_lock_limit;
6551 user_locked += user_extra;
6553 if (user_locked > user_lock_limit) {
6555 * charge locked_vm until it hits user_lock_limit;
6556 * charge the rest from pinned_vm
6558 extra = user_locked - user_lock_limit;
6559 user_extra -= extra;
6562 lock_limit = rlimit(RLIMIT_MEMLOCK);
6563 lock_limit >>= PAGE_SHIFT;
6564 locked = atomic64_read(&vma->vm_mm->pinned_vm) + extra;
6566 if ((locked > lock_limit) && perf_is_paranoid() &&
6567 !capable(CAP_IPC_LOCK)) {
6572 WARN_ON(!rb && event->rb);
6574 if (vma->vm_flags & VM_WRITE)
6575 flags |= RING_BUFFER_WRITABLE;
6578 rb = rb_alloc(nr_pages,
6579 event->attr.watermark ? event->attr.wakeup_watermark : 0,
6587 atomic_set(&rb->mmap_count, 1);
6588 rb->mmap_user = get_current_user();
6589 rb->mmap_locked = extra;
6591 ring_buffer_attach(event, rb);
6593 perf_event_update_time(event);
6594 perf_event_init_userpage(event);
6595 perf_event_update_userpage(event);
6597 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
6598 event->attr.aux_watermark, flags);
6600 rb->aux_mmap_locked = extra;
6605 atomic_long_add(user_extra, &user->locked_vm);
6606 atomic64_add(extra, &vma->vm_mm->pinned_vm);
6608 atomic_inc(&event->mmap_count);
6610 atomic_dec(&rb->mmap_count);
6613 mutex_unlock(&event->mmap_mutex);
6616 * Since pinned accounting is per vm we cannot allow fork() to copy our
6619 vm_flags_set(vma, VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP);
6620 vma->vm_ops = &perf_mmap_vmops;
6622 if (event->pmu->event_mapped)
6623 event->pmu->event_mapped(event, vma->vm_mm);
6628 static int perf_fasync(int fd, struct file *filp, int on)
6630 struct inode *inode = file_inode(filp);
6631 struct perf_event *event = filp->private_data;
6635 retval = fasync_helper(fd, filp, on, &event->fasync);
6636 inode_unlock(inode);
6644 static const struct file_operations perf_fops = {
6645 .llseek = no_llseek,
6646 .release = perf_release,
6649 .unlocked_ioctl = perf_ioctl,
6650 .compat_ioctl = perf_compat_ioctl,
6652 .fasync = perf_fasync,
6658 * If there's data, ensure we set the poll() state and publish everything
6659 * to user-space before waking everybody up.
6662 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
6664 /* only the parent has fasync state */
6666 event = event->parent;
6667 return &event->fasync;
6670 void perf_event_wakeup(struct perf_event *event)
6672 ring_buffer_wakeup(event);
6674 if (event->pending_kill) {
6675 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
6676 event->pending_kill = 0;
6680 static void perf_sigtrap(struct perf_event *event)
6683 * We'd expect this to only occur if the irq_work is delayed and either
6684 * ctx->task or current has changed in the meantime. This can be the
6685 * case on architectures that do not implement arch_irq_work_raise().
6687 if (WARN_ON_ONCE(event->ctx->task != current))
6691 * Both perf_pending_task() and perf_pending_irq() can race with the
6694 if (current->flags & PF_EXITING)
6697 send_sig_perf((void __user *)event->pending_addr,
6698 event->orig_type, event->attr.sig_data);
6702 * Deliver the pending work in-event-context or follow the context.
6704 static void __perf_pending_irq(struct perf_event *event)
6706 int cpu = READ_ONCE(event->oncpu);
6709 * If the event isn't running; we done. event_sched_out() will have
6710 * taken care of things.
6716 * Yay, we hit home and are in the context of the event.
6718 if (cpu == smp_processor_id()) {
6719 if (event->pending_sigtrap) {
6720 event->pending_sigtrap = 0;
6721 perf_sigtrap(event);
6722 local_dec(&event->ctx->nr_pending);
6724 if (event->pending_disable) {
6725 event->pending_disable = 0;
6726 perf_event_disable_local(event);
6734 * perf_event_disable_inatomic()
6735 * @pending_disable = CPU-A;
6739 * @pending_disable = -1;
6742 * perf_event_disable_inatomic()
6743 * @pending_disable = CPU-B;
6744 * irq_work_queue(); // FAILS
6747 * perf_pending_irq()
6749 * But the event runs on CPU-B and wants disabling there.
6751 irq_work_queue_on(&event->pending_irq, cpu);
6754 static void perf_pending_irq(struct irq_work *entry)
6756 struct perf_event *event = container_of(entry, struct perf_event, pending_irq);
6760 * If we 'fail' here, that's OK, it means recursion is already disabled
6761 * and we won't recurse 'further'.
6763 rctx = perf_swevent_get_recursion_context();
6766 * The wakeup isn't bound to the context of the event -- it can happen
6767 * irrespective of where the event is.
6769 if (event->pending_wakeup) {
6770 event->pending_wakeup = 0;
6771 perf_event_wakeup(event);
6774 __perf_pending_irq(event);
6777 perf_swevent_put_recursion_context(rctx);
6780 static void perf_pending_task(struct callback_head *head)
6782 struct perf_event *event = container_of(head, struct perf_event, pending_task);
6786 * If we 'fail' here, that's OK, it means recursion is already disabled
6787 * and we won't recurse 'further'.
6789 preempt_disable_notrace();
6790 rctx = perf_swevent_get_recursion_context();
6792 if (event->pending_work) {
6793 event->pending_work = 0;
6794 perf_sigtrap(event);
6795 local_dec(&event->ctx->nr_pending);
6799 perf_swevent_put_recursion_context(rctx);
6800 preempt_enable_notrace();
6805 #ifdef CONFIG_GUEST_PERF_EVENTS
6806 struct perf_guest_info_callbacks __rcu *perf_guest_cbs;
6808 DEFINE_STATIC_CALL_RET0(__perf_guest_state, *perf_guest_cbs->state);
6809 DEFINE_STATIC_CALL_RET0(__perf_guest_get_ip, *perf_guest_cbs->get_ip);
6810 DEFINE_STATIC_CALL_RET0(__perf_guest_handle_intel_pt_intr, *perf_guest_cbs->handle_intel_pt_intr);
6812 void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
6814 if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs)))
6817 rcu_assign_pointer(perf_guest_cbs, cbs);
6818 static_call_update(__perf_guest_state, cbs->state);
6819 static_call_update(__perf_guest_get_ip, cbs->get_ip);
6821 /* Implementing ->handle_intel_pt_intr is optional. */
6822 if (cbs->handle_intel_pt_intr)
6823 static_call_update(__perf_guest_handle_intel_pt_intr,
6824 cbs->handle_intel_pt_intr);
6826 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
6828 void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
6830 if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs))
6833 rcu_assign_pointer(perf_guest_cbs, NULL);
6834 static_call_update(__perf_guest_state, (void *)&__static_call_return0);
6835 static_call_update(__perf_guest_get_ip, (void *)&__static_call_return0);
6836 static_call_update(__perf_guest_handle_intel_pt_intr,
6837 (void *)&__static_call_return0);
6840 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
6844 perf_output_sample_regs(struct perf_output_handle *handle,
6845 struct pt_regs *regs, u64 mask)
6848 DECLARE_BITMAP(_mask, 64);
6850 bitmap_from_u64(_mask, mask);
6851 for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) {
6854 val = perf_reg_value(regs, bit);
6855 perf_output_put(handle, val);
6859 static void perf_sample_regs_user(struct perf_regs *regs_user,
6860 struct pt_regs *regs)
6862 if (user_mode(regs)) {
6863 regs_user->abi = perf_reg_abi(current);
6864 regs_user->regs = regs;
6865 } else if (!(current->flags & PF_KTHREAD)) {
6866 perf_get_regs_user(regs_user, regs);
6868 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
6869 regs_user->regs = NULL;
6873 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
6874 struct pt_regs *regs)
6876 regs_intr->regs = regs;
6877 regs_intr->abi = perf_reg_abi(current);
6882 * Get remaining task size from user stack pointer.
6884 * It'd be better to take stack vma map and limit this more
6885 * precisely, but there's no way to get it safely under interrupt,
6886 * so using TASK_SIZE as limit.
6888 static u64 perf_ustack_task_size(struct pt_regs *regs)
6890 unsigned long addr = perf_user_stack_pointer(regs);
6892 if (!addr || addr >= TASK_SIZE)
6895 return TASK_SIZE - addr;
6899 perf_sample_ustack_size(u16 stack_size, u16 header_size,
6900 struct pt_regs *regs)
6904 /* No regs, no stack pointer, no dump. */
6909 * Check if we fit in with the requested stack size into the:
6911 * If we don't, we limit the size to the TASK_SIZE.
6913 * - remaining sample size
6914 * If we don't, we customize the stack size to
6915 * fit in to the remaining sample size.
6918 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
6919 stack_size = min(stack_size, (u16) task_size);
6921 /* Current header size plus static size and dynamic size. */
6922 header_size += 2 * sizeof(u64);
6924 /* Do we fit in with the current stack dump size? */
6925 if ((u16) (header_size + stack_size) < header_size) {
6927 * If we overflow the maximum size for the sample,
6928 * we customize the stack dump size to fit in.
6930 stack_size = USHRT_MAX - header_size - sizeof(u64);
6931 stack_size = round_up(stack_size, sizeof(u64));
6938 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
6939 struct pt_regs *regs)
6941 /* Case of a kernel thread, nothing to dump */
6944 perf_output_put(handle, size);
6953 * - the size requested by user or the best one we can fit
6954 * in to the sample max size
6956 * - user stack dump data
6958 * - the actual dumped size
6962 perf_output_put(handle, dump_size);
6965 sp = perf_user_stack_pointer(regs);
6966 rem = __output_copy_user(handle, (void *) sp, dump_size);
6967 dyn_size = dump_size - rem;
6969 perf_output_skip(handle, rem);
6972 perf_output_put(handle, dyn_size);
6976 static unsigned long perf_prepare_sample_aux(struct perf_event *event,
6977 struct perf_sample_data *data,
6980 struct perf_event *sampler = event->aux_event;
6981 struct perf_buffer *rb;
6988 if (WARN_ON_ONCE(READ_ONCE(sampler->state) != PERF_EVENT_STATE_ACTIVE))
6991 if (WARN_ON_ONCE(READ_ONCE(sampler->oncpu) != smp_processor_id()))
6994 rb = ring_buffer_get(sampler);
6999 * If this is an NMI hit inside sampling code, don't take
7000 * the sample. See also perf_aux_sample_output().
7002 if (READ_ONCE(rb->aux_in_sampling)) {
7005 size = min_t(size_t, size, perf_aux_size(rb));
7006 data->aux_size = ALIGN(size, sizeof(u64));
7008 ring_buffer_put(rb);
7011 return data->aux_size;
7014 static long perf_pmu_snapshot_aux(struct perf_buffer *rb,
7015 struct perf_event *event,
7016 struct perf_output_handle *handle,
7019 unsigned long flags;
7023 * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
7024 * paths. If we start calling them in NMI context, they may race with
7025 * the IRQ ones, that is, for example, re-starting an event that's just
7026 * been stopped, which is why we're using a separate callback that
7027 * doesn't change the event state.
7029 * IRQs need to be disabled to prevent IPIs from racing with us.
7031 local_irq_save(flags);
7033 * Guard against NMI hits inside the critical section;
7034 * see also perf_prepare_sample_aux().
7036 WRITE_ONCE(rb->aux_in_sampling, 1);
7039 ret = event->pmu->snapshot_aux(event, handle, size);
7042 WRITE_ONCE(rb->aux_in_sampling, 0);
7043 local_irq_restore(flags);
7048 static void perf_aux_sample_output(struct perf_event *event,
7049 struct perf_output_handle *handle,
7050 struct perf_sample_data *data)
7052 struct perf_event *sampler = event->aux_event;
7053 struct perf_buffer *rb;
7057 if (WARN_ON_ONCE(!sampler || !data->aux_size))
7060 rb = ring_buffer_get(sampler);
7064 size = perf_pmu_snapshot_aux(rb, sampler, handle, data->aux_size);
7067 * An error here means that perf_output_copy() failed (returned a
7068 * non-zero surplus that it didn't copy), which in its current
7069 * enlightened implementation is not possible. If that changes, we'd
7072 if (WARN_ON_ONCE(size < 0))
7076 * The pad comes from ALIGN()ing data->aux_size up to u64 in
7077 * perf_prepare_sample_aux(), so should not be more than that.
7079 pad = data->aux_size - size;
7080 if (WARN_ON_ONCE(pad >= sizeof(u64)))
7085 perf_output_copy(handle, &zero, pad);
7089 ring_buffer_put(rb);
7093 * A set of common sample data types saved even for non-sample records
7094 * when event->attr.sample_id_all is set.
7096 #define PERF_SAMPLE_ID_ALL (PERF_SAMPLE_TID | PERF_SAMPLE_TIME | \
7097 PERF_SAMPLE_ID | PERF_SAMPLE_STREAM_ID | \
7098 PERF_SAMPLE_CPU | PERF_SAMPLE_IDENTIFIER)
7100 static void __perf_event_header__init_id(struct perf_sample_data *data,
7101 struct perf_event *event,
7104 data->type = event->attr.sample_type;
7105 data->sample_flags |= data->type & PERF_SAMPLE_ID_ALL;
7107 if (sample_type & PERF_SAMPLE_TID) {
7108 /* namespace issues */
7109 data->tid_entry.pid = perf_event_pid(event, current);
7110 data->tid_entry.tid = perf_event_tid(event, current);
7113 if (sample_type & PERF_SAMPLE_TIME)
7114 data->time = perf_event_clock(event);
7116 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
7117 data->id = primary_event_id(event);
7119 if (sample_type & PERF_SAMPLE_STREAM_ID)
7120 data->stream_id = event->id;
7122 if (sample_type & PERF_SAMPLE_CPU) {
7123 data->cpu_entry.cpu = raw_smp_processor_id();
7124 data->cpu_entry.reserved = 0;
7128 void perf_event_header__init_id(struct perf_event_header *header,
7129 struct perf_sample_data *data,
7130 struct perf_event *event)
7132 if (event->attr.sample_id_all) {
7133 header->size += event->id_header_size;
7134 __perf_event_header__init_id(data, event, event->attr.sample_type);
7138 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
7139 struct perf_sample_data *data)
7141 u64 sample_type = data->type;
7143 if (sample_type & PERF_SAMPLE_TID)
7144 perf_output_put(handle, data->tid_entry);
7146 if (sample_type & PERF_SAMPLE_TIME)
7147 perf_output_put(handle, data->time);
7149 if (sample_type & PERF_SAMPLE_ID)
7150 perf_output_put(handle, data->id);
7152 if (sample_type & PERF_SAMPLE_STREAM_ID)
7153 perf_output_put(handle, data->stream_id);
7155 if (sample_type & PERF_SAMPLE_CPU)
7156 perf_output_put(handle, data->cpu_entry);
7158 if (sample_type & PERF_SAMPLE_IDENTIFIER)
7159 perf_output_put(handle, data->id);
7162 void perf_event__output_id_sample(struct perf_event *event,
7163 struct perf_output_handle *handle,
7164 struct perf_sample_data *sample)
7166 if (event->attr.sample_id_all)
7167 __perf_event__output_id_sample(handle, sample);
7170 static void perf_output_read_one(struct perf_output_handle *handle,
7171 struct perf_event *event,
7172 u64 enabled, u64 running)
7174 u64 read_format = event->attr.read_format;
7178 values[n++] = perf_event_count(event);
7179 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
7180 values[n++] = enabled +
7181 atomic64_read(&event->child_total_time_enabled);
7183 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
7184 values[n++] = running +
7185 atomic64_read(&event->child_total_time_running);
7187 if (read_format & PERF_FORMAT_ID)
7188 values[n++] = primary_event_id(event);
7189 if (read_format & PERF_FORMAT_LOST)
7190 values[n++] = atomic64_read(&event->lost_samples);
7192 __output_copy(handle, values, n * sizeof(u64));
7195 static void perf_output_read_group(struct perf_output_handle *handle,
7196 struct perf_event *event,
7197 u64 enabled, u64 running)
7199 struct perf_event *leader = event->group_leader, *sub;
7200 u64 read_format = event->attr.read_format;
7201 unsigned long flags;
7206 * Disabling interrupts avoids all counter scheduling
7207 * (context switches, timer based rotation and IPIs).
7209 local_irq_save(flags);
7211 values[n++] = 1 + leader->nr_siblings;
7213 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
7214 values[n++] = enabled;
7216 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
7217 values[n++] = running;
7219 if ((leader != event) &&
7220 (leader->state == PERF_EVENT_STATE_ACTIVE))
7221 leader->pmu->read(leader);
7223 values[n++] = perf_event_count(leader);
7224 if (read_format & PERF_FORMAT_ID)
7225 values[n++] = primary_event_id(leader);
7226 if (read_format & PERF_FORMAT_LOST)
7227 values[n++] = atomic64_read(&leader->lost_samples);
7229 __output_copy(handle, values, n * sizeof(u64));
7231 for_each_sibling_event(sub, leader) {
7234 if ((sub != event) &&
7235 (sub->state == PERF_EVENT_STATE_ACTIVE))
7236 sub->pmu->read(sub);
7238 values[n++] = perf_event_count(sub);
7239 if (read_format & PERF_FORMAT_ID)
7240 values[n++] = primary_event_id(sub);
7241 if (read_format & PERF_FORMAT_LOST)
7242 values[n++] = atomic64_read(&sub->lost_samples);
7244 __output_copy(handle, values, n * sizeof(u64));
7247 local_irq_restore(flags);
7250 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
7251 PERF_FORMAT_TOTAL_TIME_RUNNING)
7254 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
7256 * The problem is that its both hard and excessively expensive to iterate the
7257 * child list, not to mention that its impossible to IPI the children running
7258 * on another CPU, from interrupt/NMI context.
7260 static void perf_output_read(struct perf_output_handle *handle,
7261 struct perf_event *event)
7263 u64 enabled = 0, running = 0, now;
7264 u64 read_format = event->attr.read_format;
7267 * compute total_time_enabled, total_time_running
7268 * based on snapshot values taken when the event
7269 * was last scheduled in.
7271 * we cannot simply called update_context_time()
7272 * because of locking issue as we are called in
7275 if (read_format & PERF_FORMAT_TOTAL_TIMES)
7276 calc_timer_values(event, &now, &enabled, &running);
7278 if (event->attr.read_format & PERF_FORMAT_GROUP)
7279 perf_output_read_group(handle, event, enabled, running);
7281 perf_output_read_one(handle, event, enabled, running);
7284 void perf_output_sample(struct perf_output_handle *handle,
7285 struct perf_event_header *header,
7286 struct perf_sample_data *data,
7287 struct perf_event *event)
7289 u64 sample_type = data->type;
7291 perf_output_put(handle, *header);
7293 if (sample_type & PERF_SAMPLE_IDENTIFIER)
7294 perf_output_put(handle, data->id);
7296 if (sample_type & PERF_SAMPLE_IP)
7297 perf_output_put(handle, data->ip);
7299 if (sample_type & PERF_SAMPLE_TID)
7300 perf_output_put(handle, data->tid_entry);
7302 if (sample_type & PERF_SAMPLE_TIME)
7303 perf_output_put(handle, data->time);
7305 if (sample_type & PERF_SAMPLE_ADDR)
7306 perf_output_put(handle, data->addr);
7308 if (sample_type & PERF_SAMPLE_ID)
7309 perf_output_put(handle, data->id);
7311 if (sample_type & PERF_SAMPLE_STREAM_ID)
7312 perf_output_put(handle, data->stream_id);
7314 if (sample_type & PERF_SAMPLE_CPU)
7315 perf_output_put(handle, data->cpu_entry);
7317 if (sample_type & PERF_SAMPLE_PERIOD)
7318 perf_output_put(handle, data->period);
7320 if (sample_type & PERF_SAMPLE_READ)
7321 perf_output_read(handle, event);
7323 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
7326 size += data->callchain->nr;
7327 size *= sizeof(u64);
7328 __output_copy(handle, data->callchain, size);
7331 if (sample_type & PERF_SAMPLE_RAW) {
7332 struct perf_raw_record *raw = data->raw;
7335 struct perf_raw_frag *frag = &raw->frag;
7337 perf_output_put(handle, raw->size);
7340 __output_custom(handle, frag->copy,
7341 frag->data, frag->size);
7343 __output_copy(handle, frag->data,
7346 if (perf_raw_frag_last(frag))
7351 __output_skip(handle, NULL, frag->pad);
7357 .size = sizeof(u32),
7360 perf_output_put(handle, raw);
7364 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
7365 if (data->br_stack) {
7368 size = data->br_stack->nr
7369 * sizeof(struct perf_branch_entry);
7371 perf_output_put(handle, data->br_stack->nr);
7372 if (branch_sample_hw_index(event))
7373 perf_output_put(handle, data->br_stack->hw_idx);
7374 perf_output_copy(handle, data->br_stack->entries, size);
7376 * Add the extension space which is appended
7377 * right after the struct perf_branch_stack.
7379 if (data->br_stack_cntr) {
7380 size = data->br_stack->nr * sizeof(u64);
7381 perf_output_copy(handle, data->br_stack_cntr, size);
7385 * we always store at least the value of nr
7388 perf_output_put(handle, nr);
7392 if (sample_type & PERF_SAMPLE_REGS_USER) {
7393 u64 abi = data->regs_user.abi;
7396 * If there are no regs to dump, notice it through
7397 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
7399 perf_output_put(handle, abi);
7402 u64 mask = event->attr.sample_regs_user;
7403 perf_output_sample_regs(handle,
7404 data->regs_user.regs,
7409 if (sample_type & PERF_SAMPLE_STACK_USER) {
7410 perf_output_sample_ustack(handle,
7411 data->stack_user_size,
7412 data->regs_user.regs);
7415 if (sample_type & PERF_SAMPLE_WEIGHT_TYPE)
7416 perf_output_put(handle, data->weight.full);
7418 if (sample_type & PERF_SAMPLE_DATA_SRC)
7419 perf_output_put(handle, data->data_src.val);
7421 if (sample_type & PERF_SAMPLE_TRANSACTION)
7422 perf_output_put(handle, data->txn);
7424 if (sample_type & PERF_SAMPLE_REGS_INTR) {
7425 u64 abi = data->regs_intr.abi;
7427 * If there are no regs to dump, notice it through
7428 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
7430 perf_output_put(handle, abi);
7433 u64 mask = event->attr.sample_regs_intr;
7435 perf_output_sample_regs(handle,
7436 data->regs_intr.regs,
7441 if (sample_type & PERF_SAMPLE_PHYS_ADDR)
7442 perf_output_put(handle, data->phys_addr);
7444 if (sample_type & PERF_SAMPLE_CGROUP)
7445 perf_output_put(handle, data->cgroup);
7447 if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
7448 perf_output_put(handle, data->data_page_size);
7450 if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
7451 perf_output_put(handle, data->code_page_size);
7453 if (sample_type & PERF_SAMPLE_AUX) {
7454 perf_output_put(handle, data->aux_size);
7457 perf_aux_sample_output(event, handle, data);
7460 if (!event->attr.watermark) {
7461 int wakeup_events = event->attr.wakeup_events;
7463 if (wakeup_events) {
7464 struct perf_buffer *rb = handle->rb;
7465 int events = local_inc_return(&rb->events);
7467 if (events >= wakeup_events) {
7468 local_sub(wakeup_events, &rb->events);
7469 local_inc(&rb->wakeup);
7475 static u64 perf_virt_to_phys(u64 virt)
7482 if (virt >= TASK_SIZE) {
7483 /* If it's vmalloc()d memory, leave phys_addr as 0 */
7484 if (virt_addr_valid((void *)(uintptr_t)virt) &&
7485 !(virt >= VMALLOC_START && virt < VMALLOC_END))
7486 phys_addr = (u64)virt_to_phys((void *)(uintptr_t)virt);
7489 * Walking the pages tables for user address.
7490 * Interrupts are disabled, so it prevents any tear down
7491 * of the page tables.
7492 * Try IRQ-safe get_user_page_fast_only first.
7493 * If failed, leave phys_addr as 0.
7495 if (current->mm != NULL) {
7498 pagefault_disable();
7499 if (get_user_page_fast_only(virt, 0, &p)) {
7500 phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
7511 * Return the pagetable size of a given virtual address.
7513 static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
7517 #ifdef CONFIG_HAVE_FAST_GUP
7524 pgdp = pgd_offset(mm, addr);
7525 pgd = READ_ONCE(*pgdp);
7530 return pgd_leaf_size(pgd);
7532 p4dp = p4d_offset_lockless(pgdp, pgd, addr);
7533 p4d = READ_ONCE(*p4dp);
7534 if (!p4d_present(p4d))
7538 return p4d_leaf_size(p4d);
7540 pudp = pud_offset_lockless(p4dp, p4d, addr);
7541 pud = READ_ONCE(*pudp);
7542 if (!pud_present(pud))
7546 return pud_leaf_size(pud);
7548 pmdp = pmd_offset_lockless(pudp, pud, addr);
7550 pmd = pmdp_get_lockless(pmdp);
7551 if (!pmd_present(pmd))
7555 return pmd_leaf_size(pmd);
7557 ptep = pte_offset_map(&pmd, addr);
7561 pte = ptep_get_lockless(ptep);
7562 if (pte_present(pte))
7563 size = pte_leaf_size(pte);
7565 #endif /* CONFIG_HAVE_FAST_GUP */
7570 static u64 perf_get_page_size(unsigned long addr)
7572 struct mm_struct *mm;
7573 unsigned long flags;
7580 * Software page-table walkers must disable IRQs,
7581 * which prevents any tear down of the page tables.
7583 local_irq_save(flags);
7588 * For kernel threads and the like, use init_mm so that
7589 * we can find kernel memory.
7594 size = perf_get_pgtable_size(mm, addr);
7596 local_irq_restore(flags);
7601 static struct perf_callchain_entry __empty_callchain = { .nr = 0, };
7603 struct perf_callchain_entry *
7604 perf_callchain(struct perf_event *event, struct pt_regs *regs)
7606 bool kernel = !event->attr.exclude_callchain_kernel;
7607 bool user = !event->attr.exclude_callchain_user;
7608 /* Disallow cross-task user callchains. */
7609 bool crosstask = event->ctx->task && event->ctx->task != current;
7610 const u32 max_stack = event->attr.sample_max_stack;
7611 struct perf_callchain_entry *callchain;
7613 if (!kernel && !user)
7614 return &__empty_callchain;
7616 callchain = get_perf_callchain(regs, 0, kernel, user,
7617 max_stack, crosstask, true);
7618 return callchain ?: &__empty_callchain;
7621 static __always_inline u64 __cond_set(u64 flags, u64 s, u64 d)
7623 return d * !!(flags & s);
7626 void perf_prepare_sample(struct perf_sample_data *data,
7627 struct perf_event *event,
7628 struct pt_regs *regs)
7630 u64 sample_type = event->attr.sample_type;
7631 u64 filtered_sample_type;
7634 * Add the sample flags that are dependent to others. And clear the
7635 * sample flags that have already been done by the PMU driver.
7637 filtered_sample_type = sample_type;
7638 filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_CODE_PAGE_SIZE,
7640 filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_DATA_PAGE_SIZE |
7641 PERF_SAMPLE_PHYS_ADDR, PERF_SAMPLE_ADDR);
7642 filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_STACK_USER,
7643 PERF_SAMPLE_REGS_USER);
7644 filtered_sample_type &= ~data->sample_flags;
7646 if (filtered_sample_type == 0) {
7647 /* Make sure it has the correct data->type for output */
7648 data->type = event->attr.sample_type;
7652 __perf_event_header__init_id(data, event, filtered_sample_type);
7654 if (filtered_sample_type & PERF_SAMPLE_IP) {
7655 data->ip = perf_instruction_pointer(regs);
7656 data->sample_flags |= PERF_SAMPLE_IP;
7659 if (filtered_sample_type & PERF_SAMPLE_CALLCHAIN)
7660 perf_sample_save_callchain(data, event, regs);
7662 if (filtered_sample_type & PERF_SAMPLE_RAW) {
7664 data->dyn_size += sizeof(u64);
7665 data->sample_flags |= PERF_SAMPLE_RAW;
7668 if (filtered_sample_type & PERF_SAMPLE_BRANCH_STACK) {
7669 data->br_stack = NULL;
7670 data->dyn_size += sizeof(u64);
7671 data->sample_flags |= PERF_SAMPLE_BRANCH_STACK;
7674 if (filtered_sample_type & PERF_SAMPLE_REGS_USER)
7675 perf_sample_regs_user(&data->regs_user, regs);
7678 * It cannot use the filtered_sample_type here as REGS_USER can be set
7679 * by STACK_USER (using __cond_set() above) and we don't want to update
7680 * the dyn_size if it's not requested by users.
7682 if ((sample_type & ~data->sample_flags) & PERF_SAMPLE_REGS_USER) {
7683 /* regs dump ABI info */
7684 int size = sizeof(u64);
7686 if (data->regs_user.regs) {
7687 u64 mask = event->attr.sample_regs_user;
7688 size += hweight64(mask) * sizeof(u64);
7691 data->dyn_size += size;
7692 data->sample_flags |= PERF_SAMPLE_REGS_USER;
7695 if (filtered_sample_type & PERF_SAMPLE_STACK_USER) {
7697 * Either we need PERF_SAMPLE_STACK_USER bit to be always
7698 * processed as the last one or have additional check added
7699 * in case new sample type is added, because we could eat
7700 * up the rest of the sample size.
7702 u16 stack_size = event->attr.sample_stack_user;
7703 u16 header_size = perf_sample_data_size(data, event);
7704 u16 size = sizeof(u64);
7706 stack_size = perf_sample_ustack_size(stack_size, header_size,
7707 data->regs_user.regs);
7710 * If there is something to dump, add space for the dump
7711 * itself and for the field that tells the dynamic size,
7712 * which is how many have been actually dumped.
7715 size += sizeof(u64) + stack_size;
7717 data->stack_user_size = stack_size;
7718 data->dyn_size += size;
7719 data->sample_flags |= PERF_SAMPLE_STACK_USER;
7722 if (filtered_sample_type & PERF_SAMPLE_WEIGHT_TYPE) {
7723 data->weight.full = 0;
7724 data->sample_flags |= PERF_SAMPLE_WEIGHT_TYPE;
7727 if (filtered_sample_type & PERF_SAMPLE_DATA_SRC) {
7728 data->data_src.val = PERF_MEM_NA;
7729 data->sample_flags |= PERF_SAMPLE_DATA_SRC;
7732 if (filtered_sample_type & PERF_SAMPLE_TRANSACTION) {
7734 data->sample_flags |= PERF_SAMPLE_TRANSACTION;
7737 if (filtered_sample_type & PERF_SAMPLE_ADDR) {
7739 data->sample_flags |= PERF_SAMPLE_ADDR;
7742 if (filtered_sample_type & PERF_SAMPLE_REGS_INTR) {
7743 /* regs dump ABI info */
7744 int size = sizeof(u64);
7746 perf_sample_regs_intr(&data->regs_intr, regs);
7748 if (data->regs_intr.regs) {
7749 u64 mask = event->attr.sample_regs_intr;
7751 size += hweight64(mask) * sizeof(u64);
7754 data->dyn_size += size;
7755 data->sample_flags |= PERF_SAMPLE_REGS_INTR;
7758 if (filtered_sample_type & PERF_SAMPLE_PHYS_ADDR) {
7759 data->phys_addr = perf_virt_to_phys(data->addr);
7760 data->sample_flags |= PERF_SAMPLE_PHYS_ADDR;
7763 #ifdef CONFIG_CGROUP_PERF
7764 if (filtered_sample_type & PERF_SAMPLE_CGROUP) {
7765 struct cgroup *cgrp;
7767 /* protected by RCU */
7768 cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup;
7769 data->cgroup = cgroup_id(cgrp);
7770 data->sample_flags |= PERF_SAMPLE_CGROUP;
7775 * PERF_DATA_PAGE_SIZE requires PERF_SAMPLE_ADDR. If the user doesn't
7776 * require PERF_SAMPLE_ADDR, kernel implicitly retrieve the data->addr,
7777 * but the value will not dump to the userspace.
7779 if (filtered_sample_type & PERF_SAMPLE_DATA_PAGE_SIZE) {
7780 data->data_page_size = perf_get_page_size(data->addr);
7781 data->sample_flags |= PERF_SAMPLE_DATA_PAGE_SIZE;
7784 if (filtered_sample_type & PERF_SAMPLE_CODE_PAGE_SIZE) {
7785 data->code_page_size = perf_get_page_size(data->ip);
7786 data->sample_flags |= PERF_SAMPLE_CODE_PAGE_SIZE;
7789 if (filtered_sample_type & PERF_SAMPLE_AUX) {
7791 u16 header_size = perf_sample_data_size(data, event);
7793 header_size += sizeof(u64); /* size */
7796 * Given the 16bit nature of header::size, an AUX sample can
7797 * easily overflow it, what with all the preceding sample bits.
7798 * Make sure this doesn't happen by using up to U16_MAX bytes
7799 * per sample in total (rounded down to 8 byte boundary).
7801 size = min_t(size_t, U16_MAX - header_size,
7802 event->attr.aux_sample_size);
7803 size = rounddown(size, 8);
7804 size = perf_prepare_sample_aux(event, data, size);
7806 WARN_ON_ONCE(size + header_size > U16_MAX);
7807 data->dyn_size += size + sizeof(u64); /* size above */
7808 data->sample_flags |= PERF_SAMPLE_AUX;
7812 void perf_prepare_header(struct perf_event_header *header,
7813 struct perf_sample_data *data,
7814 struct perf_event *event,
7815 struct pt_regs *regs)
7817 header->type = PERF_RECORD_SAMPLE;
7818 header->size = perf_sample_data_size(data, event);
7819 header->misc = perf_misc_flags(regs);
7822 * If you're adding more sample types here, you likely need to do
7823 * something about the overflowing header::size, like repurpose the
7824 * lowest 3 bits of size, which should be always zero at the moment.
7825 * This raises a more important question, do we really need 512k sized
7826 * samples and why, so good argumentation is in order for whatever you
7829 WARN_ON_ONCE(header->size & 7);
7832 static __always_inline int
7833 __perf_event_output(struct perf_event *event,
7834 struct perf_sample_data *data,
7835 struct pt_regs *regs,
7836 int (*output_begin)(struct perf_output_handle *,
7837 struct perf_sample_data *,
7838 struct perf_event *,
7841 struct perf_output_handle handle;
7842 struct perf_event_header header;
7845 /* protect the callchain buffers */
7848 perf_prepare_sample(data, event, regs);
7849 perf_prepare_header(&header, data, event, regs);
7851 err = output_begin(&handle, data, event, header.size);
7855 perf_output_sample(&handle, &header, data, event);
7857 perf_output_end(&handle);
7865 perf_event_output_forward(struct perf_event *event,
7866 struct perf_sample_data *data,
7867 struct pt_regs *regs)
7869 __perf_event_output(event, data, regs, perf_output_begin_forward);
7873 perf_event_output_backward(struct perf_event *event,
7874 struct perf_sample_data *data,
7875 struct pt_regs *regs)
7877 __perf_event_output(event, data, regs, perf_output_begin_backward);
7881 perf_event_output(struct perf_event *event,
7882 struct perf_sample_data *data,
7883 struct pt_regs *regs)
7885 return __perf_event_output(event, data, regs, perf_output_begin);
7892 struct perf_read_event {
7893 struct perf_event_header header;
7900 perf_event_read_event(struct perf_event *event,
7901 struct task_struct *task)
7903 struct perf_output_handle handle;
7904 struct perf_sample_data sample;
7905 struct perf_read_event read_event = {
7907 .type = PERF_RECORD_READ,
7909 .size = sizeof(read_event) + event->read_size,
7911 .pid = perf_event_pid(event, task),
7912 .tid = perf_event_tid(event, task),
7916 perf_event_header__init_id(&read_event.header, &sample, event);
7917 ret = perf_output_begin(&handle, &sample, event, read_event.header.size);
7921 perf_output_put(&handle, read_event);
7922 perf_output_read(&handle, event);
7923 perf_event__output_id_sample(event, &handle, &sample);
7925 perf_output_end(&handle);
7928 typedef void (perf_iterate_f)(struct perf_event *event, void *data);
7931 perf_iterate_ctx(struct perf_event_context *ctx,
7932 perf_iterate_f output,
7933 void *data, bool all)
7935 struct perf_event *event;
7937 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
7939 if (event->state < PERF_EVENT_STATE_INACTIVE)
7941 if (!event_filter_match(event))
7945 output(event, data);
7949 static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
7951 struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
7952 struct perf_event *event;
7954 list_for_each_entry_rcu(event, &pel->list, sb_list) {
7956 * Skip events that are not fully formed yet; ensure that
7957 * if we observe event->ctx, both event and ctx will be
7958 * complete enough. See perf_install_in_context().
7960 if (!smp_load_acquire(&event->ctx))
7963 if (event->state < PERF_EVENT_STATE_INACTIVE)
7965 if (!event_filter_match(event))
7967 output(event, data);
7972 * Iterate all events that need to receive side-band events.
7974 * For new callers; ensure that account_pmu_sb_event() includes
7975 * your event, otherwise it might not get delivered.
7978 perf_iterate_sb(perf_iterate_f output, void *data,
7979 struct perf_event_context *task_ctx)
7981 struct perf_event_context *ctx;
7987 * If we have task_ctx != NULL we only notify the task context itself.
7988 * The task_ctx is set only for EXIT events before releasing task
7992 perf_iterate_ctx(task_ctx, output, data, false);
7996 perf_iterate_sb_cpu(output, data);
7998 ctx = rcu_dereference(current->perf_event_ctxp);
8000 perf_iterate_ctx(ctx, output, data, false);
8007 * Clear all file-based filters at exec, they'll have to be
8008 * re-instated when/if these objects are mmapped again.
8010 static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
8012 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
8013 struct perf_addr_filter *filter;
8014 unsigned int restart = 0, count = 0;
8015 unsigned long flags;
8017 if (!has_addr_filter(event))
8020 raw_spin_lock_irqsave(&ifh->lock, flags);
8021 list_for_each_entry(filter, &ifh->list, entry) {
8022 if (filter->path.dentry) {
8023 event->addr_filter_ranges[count].start = 0;
8024 event->addr_filter_ranges[count].size = 0;
8032 event->addr_filters_gen++;
8033 raw_spin_unlock_irqrestore(&ifh->lock, flags);
8036 perf_event_stop(event, 1);
8039 void perf_event_exec(void)
8041 struct perf_event_context *ctx;
8043 ctx = perf_pin_task_context(current);
8047 perf_event_enable_on_exec(ctx);
8048 perf_event_remove_on_exec(ctx);
8049 perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true);
8051 perf_unpin_context(ctx);
8055 struct remote_output {
8056 struct perf_buffer *rb;
8060 static void __perf_event_output_stop(struct perf_event *event, void *data)
8062 struct perf_event *parent = event->parent;
8063 struct remote_output *ro = data;
8064 struct perf_buffer *rb = ro->rb;
8065 struct stop_event_data sd = {
8069 if (!has_aux(event))
8076 * In case of inheritance, it will be the parent that links to the
8077 * ring-buffer, but it will be the child that's actually using it.
8079 * We are using event::rb to determine if the event should be stopped,
8080 * however this may race with ring_buffer_attach() (through set_output),
8081 * which will make us skip the event that actually needs to be stopped.
8082 * So ring_buffer_attach() has to stop an aux event before re-assigning
8085 if (rcu_dereference(parent->rb) == rb)
8086 ro->err = __perf_event_stop(&sd);
8089 static int __perf_pmu_output_stop(void *info)
8091 struct perf_event *event = info;
8092 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
8093 struct remote_output ro = {
8098 perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
8099 if (cpuctx->task_ctx)
8100 perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
8107 static void perf_pmu_output_stop(struct perf_event *event)
8109 struct perf_event *iter;
8114 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
8116 * For per-CPU events, we need to make sure that neither they
8117 * nor their children are running; for cpu==-1 events it's
8118 * sufficient to stop the event itself if it's active, since
8119 * it can't have children.
8123 cpu = READ_ONCE(iter->oncpu);
8128 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
8129 if (err == -EAGAIN) {
8138 * task tracking -- fork/exit
8140 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
8143 struct perf_task_event {
8144 struct task_struct *task;
8145 struct perf_event_context *task_ctx;
8148 struct perf_event_header header;
8158 static int perf_event_task_match(struct perf_event *event)
8160 return event->attr.comm || event->attr.mmap ||
8161 event->attr.mmap2 || event->attr.mmap_data ||
8165 static void perf_event_task_output(struct perf_event *event,
8168 struct perf_task_event *task_event = data;
8169 struct perf_output_handle handle;
8170 struct perf_sample_data sample;
8171 struct task_struct *task = task_event->task;
8172 int ret, size = task_event->event_id.header.size;
8174 if (!perf_event_task_match(event))
8177 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
8179 ret = perf_output_begin(&handle, &sample, event,
8180 task_event->event_id.header.size);
8184 task_event->event_id.pid = perf_event_pid(event, task);
8185 task_event->event_id.tid = perf_event_tid(event, task);
8187 if (task_event->event_id.header.type == PERF_RECORD_EXIT) {
8188 task_event->event_id.ppid = perf_event_pid(event,
8190 task_event->event_id.ptid = perf_event_pid(event,
8192 } else { /* PERF_RECORD_FORK */
8193 task_event->event_id.ppid = perf_event_pid(event, current);
8194 task_event->event_id.ptid = perf_event_tid(event, current);
8197 task_event->event_id.time = perf_event_clock(event);
8199 perf_output_put(&handle, task_event->event_id);
8201 perf_event__output_id_sample(event, &handle, &sample);
8203 perf_output_end(&handle);
8205 task_event->event_id.header.size = size;
8208 static void perf_event_task(struct task_struct *task,
8209 struct perf_event_context *task_ctx,
8212 struct perf_task_event task_event;
8214 if (!atomic_read(&nr_comm_events) &&
8215 !atomic_read(&nr_mmap_events) &&
8216 !atomic_read(&nr_task_events))
8219 task_event = (struct perf_task_event){
8221 .task_ctx = task_ctx,
8224 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
8226 .size = sizeof(task_event.event_id),
8236 perf_iterate_sb(perf_event_task_output,
8241 void perf_event_fork(struct task_struct *task)
8243 perf_event_task(task, NULL, 1);
8244 perf_event_namespaces(task);
8251 struct perf_comm_event {
8252 struct task_struct *task;
8257 struct perf_event_header header;
8264 static int perf_event_comm_match(struct perf_event *event)
8266 return event->attr.comm;
8269 static void perf_event_comm_output(struct perf_event *event,
8272 struct perf_comm_event *comm_event = data;
8273 struct perf_output_handle handle;
8274 struct perf_sample_data sample;
8275 int size = comm_event->event_id.header.size;
8278 if (!perf_event_comm_match(event))
8281 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
8282 ret = perf_output_begin(&handle, &sample, event,
8283 comm_event->event_id.header.size);
8288 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
8289 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
8291 perf_output_put(&handle, comm_event->event_id);
8292 __output_copy(&handle, comm_event->comm,
8293 comm_event->comm_size);
8295 perf_event__output_id_sample(event, &handle, &sample);
8297 perf_output_end(&handle);
8299 comm_event->event_id.header.size = size;
8302 static void perf_event_comm_event(struct perf_comm_event *comm_event)
8304 char comm[TASK_COMM_LEN];
8307 memset(comm, 0, sizeof(comm));
8308 strscpy(comm, comm_event->task->comm, sizeof(comm));
8309 size = ALIGN(strlen(comm)+1, sizeof(u64));
8311 comm_event->comm = comm;
8312 comm_event->comm_size = size;
8314 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
8316 perf_iterate_sb(perf_event_comm_output,
8321 void perf_event_comm(struct task_struct *task, bool exec)
8323 struct perf_comm_event comm_event;
8325 if (!atomic_read(&nr_comm_events))
8328 comm_event = (struct perf_comm_event){
8334 .type = PERF_RECORD_COMM,
8335 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
8343 perf_event_comm_event(&comm_event);
8347 * namespaces tracking
8350 struct perf_namespaces_event {
8351 struct task_struct *task;
8354 struct perf_event_header header;
8359 struct perf_ns_link_info link_info[NR_NAMESPACES];
8363 static int perf_event_namespaces_match(struct perf_event *event)
8365 return event->attr.namespaces;
8368 static void perf_event_namespaces_output(struct perf_event *event,
8371 struct perf_namespaces_event *namespaces_event = data;
8372 struct perf_output_handle handle;
8373 struct perf_sample_data sample;
8374 u16 header_size = namespaces_event->event_id.header.size;
8377 if (!perf_event_namespaces_match(event))
8380 perf_event_header__init_id(&namespaces_event->event_id.header,
8382 ret = perf_output_begin(&handle, &sample, event,
8383 namespaces_event->event_id.header.size);
8387 namespaces_event->event_id.pid = perf_event_pid(event,
8388 namespaces_event->task);
8389 namespaces_event->event_id.tid = perf_event_tid(event,
8390 namespaces_event->task);
8392 perf_output_put(&handle, namespaces_event->event_id);
8394 perf_event__output_id_sample(event, &handle, &sample);
8396 perf_output_end(&handle);
8398 namespaces_event->event_id.header.size = header_size;
8401 static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
8402 struct task_struct *task,
8403 const struct proc_ns_operations *ns_ops)
8405 struct path ns_path;
8406 struct inode *ns_inode;
8409 error = ns_get_path(&ns_path, task, ns_ops);
8411 ns_inode = ns_path.dentry->d_inode;
8412 ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev);
8413 ns_link_info->ino = ns_inode->i_ino;
8418 void perf_event_namespaces(struct task_struct *task)
8420 struct perf_namespaces_event namespaces_event;
8421 struct perf_ns_link_info *ns_link_info;
8423 if (!atomic_read(&nr_namespaces_events))
8426 namespaces_event = (struct perf_namespaces_event){
8430 .type = PERF_RECORD_NAMESPACES,
8432 .size = sizeof(namespaces_event.event_id),
8436 .nr_namespaces = NR_NAMESPACES,
8437 /* .link_info[NR_NAMESPACES] */
8441 ns_link_info = namespaces_event.event_id.link_info;
8443 perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX],
8444 task, &mntns_operations);
8446 #ifdef CONFIG_USER_NS
8447 perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX],
8448 task, &userns_operations);
8450 #ifdef CONFIG_NET_NS
8451 perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX],
8452 task, &netns_operations);
8454 #ifdef CONFIG_UTS_NS
8455 perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX],
8456 task, &utsns_operations);
8458 #ifdef CONFIG_IPC_NS
8459 perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX],
8460 task, &ipcns_operations);
8462 #ifdef CONFIG_PID_NS
8463 perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX],
8464 task, &pidns_operations);
8466 #ifdef CONFIG_CGROUPS
8467 perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX],
8468 task, &cgroupns_operations);
8471 perf_iterate_sb(perf_event_namespaces_output,
8479 #ifdef CONFIG_CGROUP_PERF
8481 struct perf_cgroup_event {
8485 struct perf_event_header header;
8491 static int perf_event_cgroup_match(struct perf_event *event)
8493 return event->attr.cgroup;
8496 static void perf_event_cgroup_output(struct perf_event *event, void *data)
8498 struct perf_cgroup_event *cgroup_event = data;
8499 struct perf_output_handle handle;
8500 struct perf_sample_data sample;
8501 u16 header_size = cgroup_event->event_id.header.size;
8504 if (!perf_event_cgroup_match(event))
8507 perf_event_header__init_id(&cgroup_event->event_id.header,
8509 ret = perf_output_begin(&handle, &sample, event,
8510 cgroup_event->event_id.header.size);
8514 perf_output_put(&handle, cgroup_event->event_id);
8515 __output_copy(&handle, cgroup_event->path, cgroup_event->path_size);
8517 perf_event__output_id_sample(event, &handle, &sample);
8519 perf_output_end(&handle);
8521 cgroup_event->event_id.header.size = header_size;
8524 static void perf_event_cgroup(struct cgroup *cgrp)
8526 struct perf_cgroup_event cgroup_event;
8527 char path_enomem[16] = "//enomem";
8531 if (!atomic_read(&nr_cgroup_events))
8534 cgroup_event = (struct perf_cgroup_event){
8537 .type = PERF_RECORD_CGROUP,
8539 .size = sizeof(cgroup_event.event_id),
8541 .id = cgroup_id(cgrp),
8545 pathname = kmalloc(PATH_MAX, GFP_KERNEL);
8546 if (pathname == NULL) {
8547 cgroup_event.path = path_enomem;
8549 /* just to be sure to have enough space for alignment */
8550 cgroup_path(cgrp, pathname, PATH_MAX - sizeof(u64));
8551 cgroup_event.path = pathname;
8555 * Since our buffer works in 8 byte units we need to align our string
8556 * size to a multiple of 8. However, we must guarantee the tail end is
8557 * zero'd out to avoid leaking random bits to userspace.
8559 size = strlen(cgroup_event.path) + 1;
8560 while (!IS_ALIGNED(size, sizeof(u64)))
8561 cgroup_event.path[size++] = '\0';
8563 cgroup_event.event_id.header.size += size;
8564 cgroup_event.path_size = size;
8566 perf_iterate_sb(perf_event_cgroup_output,
8579 struct perf_mmap_event {
8580 struct vm_area_struct *vma;
8582 const char *file_name;
8588 u8 build_id[BUILD_ID_SIZE_MAX];
8592 struct perf_event_header header;
8602 static int perf_event_mmap_match(struct perf_event *event,
8605 struct perf_mmap_event *mmap_event = data;
8606 struct vm_area_struct *vma = mmap_event->vma;
8607 int executable = vma->vm_flags & VM_EXEC;
8609 return (!executable && event->attr.mmap_data) ||
8610 (executable && (event->attr.mmap || event->attr.mmap2));
8613 static void perf_event_mmap_output(struct perf_event *event,
8616 struct perf_mmap_event *mmap_event = data;
8617 struct perf_output_handle handle;
8618 struct perf_sample_data sample;
8619 int size = mmap_event->event_id.header.size;
8620 u32 type = mmap_event->event_id.header.type;
8624 if (!perf_event_mmap_match(event, data))
8627 if (event->attr.mmap2) {
8628 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
8629 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
8630 mmap_event->event_id.header.size += sizeof(mmap_event->min);
8631 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
8632 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
8633 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
8634 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
8637 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
8638 ret = perf_output_begin(&handle, &sample, event,
8639 mmap_event->event_id.header.size);
8643 mmap_event->event_id.pid = perf_event_pid(event, current);
8644 mmap_event->event_id.tid = perf_event_tid(event, current);
8646 use_build_id = event->attr.build_id && mmap_event->build_id_size;
8648 if (event->attr.mmap2 && use_build_id)
8649 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;
8651 perf_output_put(&handle, mmap_event->event_id);
8653 if (event->attr.mmap2) {
8655 u8 size[4] = { (u8) mmap_event->build_id_size, 0, 0, 0 };
8657 __output_copy(&handle, size, 4);
8658 __output_copy(&handle, mmap_event->build_id, BUILD_ID_SIZE_MAX);
8660 perf_output_put(&handle, mmap_event->maj);
8661 perf_output_put(&handle, mmap_event->min);
8662 perf_output_put(&handle, mmap_event->ino);
8663 perf_output_put(&handle, mmap_event->ino_generation);
8665 perf_output_put(&handle, mmap_event->prot);
8666 perf_output_put(&handle, mmap_event->flags);
8669 __output_copy(&handle, mmap_event->file_name,
8670 mmap_event->file_size);
8672 perf_event__output_id_sample(event, &handle, &sample);
8674 perf_output_end(&handle);
8676 mmap_event->event_id.header.size = size;
8677 mmap_event->event_id.header.type = type;
8680 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
8682 struct vm_area_struct *vma = mmap_event->vma;
8683 struct file *file = vma->vm_file;
8684 int maj = 0, min = 0;
8685 u64 ino = 0, gen = 0;
8686 u32 prot = 0, flags = 0;
8692 if (vma->vm_flags & VM_READ)
8694 if (vma->vm_flags & VM_WRITE)
8696 if (vma->vm_flags & VM_EXEC)
8699 if (vma->vm_flags & VM_MAYSHARE)
8702 flags = MAP_PRIVATE;
8704 if (vma->vm_flags & VM_LOCKED)
8705 flags |= MAP_LOCKED;
8706 if (is_vm_hugetlb_page(vma))
8707 flags |= MAP_HUGETLB;
8710 struct inode *inode;
8713 buf = kmalloc(PATH_MAX, GFP_KERNEL);
8719 * d_path() works from the end of the rb backwards, so we
8720 * need to add enough zero bytes after the string to handle
8721 * the 64bit alignment we do later.
8723 name = file_path(file, buf, PATH_MAX - sizeof(u64));
8728 inode = file_inode(vma->vm_file);
8729 dev = inode->i_sb->s_dev;
8731 gen = inode->i_generation;
8737 if (vma->vm_ops && vma->vm_ops->name)
8738 name = (char *) vma->vm_ops->name(vma);
8740 name = (char *)arch_vma_name(vma);
8742 if (vma_is_initial_heap(vma))
8744 else if (vma_is_initial_stack(vma))
8752 strscpy(tmp, name, sizeof(tmp));
8756 * Since our buffer works in 8 byte units we need to align our string
8757 * size to a multiple of 8. However, we must guarantee the tail end is
8758 * zero'd out to avoid leaking random bits to userspace.
8760 size = strlen(name)+1;
8761 while (!IS_ALIGNED(size, sizeof(u64)))
8762 name[size++] = '\0';
8764 mmap_event->file_name = name;
8765 mmap_event->file_size = size;
8766 mmap_event->maj = maj;
8767 mmap_event->min = min;
8768 mmap_event->ino = ino;
8769 mmap_event->ino_generation = gen;
8770 mmap_event->prot = prot;
8771 mmap_event->flags = flags;
8773 if (!(vma->vm_flags & VM_EXEC))
8774 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
8776 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
8778 if (atomic_read(&nr_build_id_events))
8779 build_id_parse(vma, mmap_event->build_id, &mmap_event->build_id_size);
8781 perf_iterate_sb(perf_event_mmap_output,
8789 * Check whether inode and address range match filter criteria.
8791 static bool perf_addr_filter_match(struct perf_addr_filter *filter,
8792 struct file *file, unsigned long offset,
8795 /* d_inode(NULL) won't be equal to any mapped user-space file */
8796 if (!filter->path.dentry)
8799 if (d_inode(filter->path.dentry) != file_inode(file))
8802 if (filter->offset > offset + size)
8805 if (filter->offset + filter->size < offset)
8811 static bool perf_addr_filter_vma_adjust(struct perf_addr_filter *filter,
8812 struct vm_area_struct *vma,
8813 struct perf_addr_filter_range *fr)
8815 unsigned long vma_size = vma->vm_end - vma->vm_start;
8816 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
8817 struct file *file = vma->vm_file;
8819 if (!perf_addr_filter_match(filter, file, off, vma_size))
8822 if (filter->offset < off) {
8823 fr->start = vma->vm_start;
8824 fr->size = min(vma_size, filter->size - (off - filter->offset));
8826 fr->start = vma->vm_start + filter->offset - off;
8827 fr->size = min(vma->vm_end - fr->start, filter->size);
8833 static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
8835 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
8836 struct vm_area_struct *vma = data;
8837 struct perf_addr_filter *filter;
8838 unsigned int restart = 0, count = 0;
8839 unsigned long flags;
8841 if (!has_addr_filter(event))
8847 raw_spin_lock_irqsave(&ifh->lock, flags);
8848 list_for_each_entry(filter, &ifh->list, entry) {
8849 if (perf_addr_filter_vma_adjust(filter, vma,
8850 &event->addr_filter_ranges[count]))
8857 event->addr_filters_gen++;
8858 raw_spin_unlock_irqrestore(&ifh->lock, flags);
8861 perf_event_stop(event, 1);
8865 * Adjust all task's events' filters to the new vma
8867 static void perf_addr_filters_adjust(struct vm_area_struct *vma)
8869 struct perf_event_context *ctx;
8872 * Data tracing isn't supported yet and as such there is no need
8873 * to keep track of anything that isn't related to executable code:
8875 if (!(vma->vm_flags & VM_EXEC))
8879 ctx = rcu_dereference(current->perf_event_ctxp);
8881 perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
8885 void perf_event_mmap(struct vm_area_struct *vma)
8887 struct perf_mmap_event mmap_event;
8889 if (!atomic_read(&nr_mmap_events))
8892 mmap_event = (struct perf_mmap_event){
8898 .type = PERF_RECORD_MMAP,
8899 .misc = PERF_RECORD_MISC_USER,
8904 .start = vma->vm_start,
8905 .len = vma->vm_end - vma->vm_start,
8906 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
8908 /* .maj (attr_mmap2 only) */
8909 /* .min (attr_mmap2 only) */
8910 /* .ino (attr_mmap2 only) */
8911 /* .ino_generation (attr_mmap2 only) */
8912 /* .prot (attr_mmap2 only) */
8913 /* .flags (attr_mmap2 only) */
8916 perf_addr_filters_adjust(vma);
8917 perf_event_mmap_event(&mmap_event);
8920 void perf_event_aux_event(struct perf_event *event, unsigned long head,
8921 unsigned long size, u64 flags)
8923 struct perf_output_handle handle;
8924 struct perf_sample_data sample;
8925 struct perf_aux_event {
8926 struct perf_event_header header;
8932 .type = PERF_RECORD_AUX,
8934 .size = sizeof(rec),
8942 perf_event_header__init_id(&rec.header, &sample, event);
8943 ret = perf_output_begin(&handle, &sample, event, rec.header.size);
8948 perf_output_put(&handle, rec);
8949 perf_event__output_id_sample(event, &handle, &sample);
8951 perf_output_end(&handle);
8955 * Lost/dropped samples logging
8957 void perf_log_lost_samples(struct perf_event *event, u64 lost)
8959 struct perf_output_handle handle;
8960 struct perf_sample_data sample;
8964 struct perf_event_header header;
8966 } lost_samples_event = {
8968 .type = PERF_RECORD_LOST_SAMPLES,
8970 .size = sizeof(lost_samples_event),
8975 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
8977 ret = perf_output_begin(&handle, &sample, event,
8978 lost_samples_event.header.size);
8982 perf_output_put(&handle, lost_samples_event);
8983 perf_event__output_id_sample(event, &handle, &sample);
8984 perf_output_end(&handle);
8988 * context_switch tracking
8991 struct perf_switch_event {
8992 struct task_struct *task;
8993 struct task_struct *next_prev;
8996 struct perf_event_header header;
9002 static int perf_event_switch_match(struct perf_event *event)
9004 return event->attr.context_switch;
9007 static void perf_event_switch_output(struct perf_event *event, void *data)
9009 struct perf_switch_event *se = data;
9010 struct perf_output_handle handle;
9011 struct perf_sample_data sample;
9014 if (!perf_event_switch_match(event))
9017 /* Only CPU-wide events are allowed to see next/prev pid/tid */
9018 if (event->ctx->task) {
9019 se->event_id.header.type = PERF_RECORD_SWITCH;
9020 se->event_id.header.size = sizeof(se->event_id.header);
9022 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
9023 se->event_id.header.size = sizeof(se->event_id);
9024 se->event_id.next_prev_pid =
9025 perf_event_pid(event, se->next_prev);
9026 se->event_id.next_prev_tid =
9027 perf_event_tid(event, se->next_prev);
9030 perf_event_header__init_id(&se->event_id.header, &sample, event);
9032 ret = perf_output_begin(&handle, &sample, event, se->event_id.header.size);
9036 if (event->ctx->task)
9037 perf_output_put(&handle, se->event_id.header);
9039 perf_output_put(&handle, se->event_id);
9041 perf_event__output_id_sample(event, &handle, &sample);
9043 perf_output_end(&handle);
9046 static void perf_event_switch(struct task_struct *task,
9047 struct task_struct *next_prev, bool sched_in)
9049 struct perf_switch_event switch_event;
9051 /* N.B. caller checks nr_switch_events != 0 */
9053 switch_event = (struct perf_switch_event){
9055 .next_prev = next_prev,
9059 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
9062 /* .next_prev_pid */
9063 /* .next_prev_tid */
9067 if (!sched_in && task->on_rq) {
9068 switch_event.event_id.header.misc |=
9069 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT;
9072 perf_iterate_sb(perf_event_switch_output, &switch_event, NULL);
9076 * IRQ throttle logging
9079 static void perf_log_throttle(struct perf_event *event, int enable)
9081 struct perf_output_handle handle;
9082 struct perf_sample_data sample;
9086 struct perf_event_header header;
9090 } throttle_event = {
9092 .type = PERF_RECORD_THROTTLE,
9094 .size = sizeof(throttle_event),
9096 .time = perf_event_clock(event),
9097 .id = primary_event_id(event),
9098 .stream_id = event->id,
9102 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
9104 perf_event_header__init_id(&throttle_event.header, &sample, event);
9106 ret = perf_output_begin(&handle, &sample, event,
9107 throttle_event.header.size);
9111 perf_output_put(&handle, throttle_event);
9112 perf_event__output_id_sample(event, &handle, &sample);
9113 perf_output_end(&handle);
9117 * ksymbol register/unregister tracking
9120 struct perf_ksymbol_event {
9124 struct perf_event_header header;
9132 static int perf_event_ksymbol_match(struct perf_event *event)
9134 return event->attr.ksymbol;
9137 static void perf_event_ksymbol_output(struct perf_event *event, void *data)
9139 struct perf_ksymbol_event *ksymbol_event = data;
9140 struct perf_output_handle handle;
9141 struct perf_sample_data sample;
9144 if (!perf_event_ksymbol_match(event))
9147 perf_event_header__init_id(&ksymbol_event->event_id.header,
9149 ret = perf_output_begin(&handle, &sample, event,
9150 ksymbol_event->event_id.header.size);
9154 perf_output_put(&handle, ksymbol_event->event_id);
9155 __output_copy(&handle, ksymbol_event->name, ksymbol_event->name_len);
9156 perf_event__output_id_sample(event, &handle, &sample);
9158 perf_output_end(&handle);
9161 void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister,
9164 struct perf_ksymbol_event ksymbol_event;
9165 char name[KSYM_NAME_LEN];
9169 if (!atomic_read(&nr_ksymbol_events))
9172 if (ksym_type >= PERF_RECORD_KSYMBOL_TYPE_MAX ||
9173 ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN)
9176 strscpy(name, sym, KSYM_NAME_LEN);
9177 name_len = strlen(name) + 1;
9178 while (!IS_ALIGNED(name_len, sizeof(u64)))
9179 name[name_len++] = '\0';
9180 BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64));
9183 flags |= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER;
9185 ksymbol_event = (struct perf_ksymbol_event){
9187 .name_len = name_len,
9190 .type = PERF_RECORD_KSYMBOL,
9191 .size = sizeof(ksymbol_event.event_id) +
9196 .ksym_type = ksym_type,
9201 perf_iterate_sb(perf_event_ksymbol_output, &ksymbol_event, NULL);
9204 WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__, ksym_type);
9208 * bpf program load/unload tracking
9211 struct perf_bpf_event {
9212 struct bpf_prog *prog;
9214 struct perf_event_header header;
9218 u8 tag[BPF_TAG_SIZE];
9222 static int perf_event_bpf_match(struct perf_event *event)
9224 return event->attr.bpf_event;
9227 static void perf_event_bpf_output(struct perf_event *event, void *data)
9229 struct perf_bpf_event *bpf_event = data;
9230 struct perf_output_handle handle;
9231 struct perf_sample_data sample;
9234 if (!perf_event_bpf_match(event))
9237 perf_event_header__init_id(&bpf_event->event_id.header,
9239 ret = perf_output_begin(&handle, &sample, event,
9240 bpf_event->event_id.header.size);
9244 perf_output_put(&handle, bpf_event->event_id);
9245 perf_event__output_id_sample(event, &handle, &sample);
9247 perf_output_end(&handle);
9250 static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog,
9251 enum perf_bpf_event_type type)
9253 bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD;
9256 if (prog->aux->func_cnt == 0) {
9257 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF,
9258 (u64)(unsigned long)prog->bpf_func,
9259 prog->jited_len, unregister,
9260 prog->aux->ksym.name);
9262 for (i = 0; i < prog->aux->func_cnt; i++) {
9263 struct bpf_prog *subprog = prog->aux->func[i];
9266 PERF_RECORD_KSYMBOL_TYPE_BPF,
9267 (u64)(unsigned long)subprog->bpf_func,
9268 subprog->jited_len, unregister,
9269 subprog->aux->ksym.name);
9274 void perf_event_bpf_event(struct bpf_prog *prog,
9275 enum perf_bpf_event_type type,
9278 struct perf_bpf_event bpf_event;
9280 if (type <= PERF_BPF_EVENT_UNKNOWN ||
9281 type >= PERF_BPF_EVENT_MAX)
9285 case PERF_BPF_EVENT_PROG_LOAD:
9286 case PERF_BPF_EVENT_PROG_UNLOAD:
9287 if (atomic_read(&nr_ksymbol_events))
9288 perf_event_bpf_emit_ksymbols(prog, type);
9294 if (!atomic_read(&nr_bpf_events))
9297 bpf_event = (struct perf_bpf_event){
9301 .type = PERF_RECORD_BPF_EVENT,
9302 .size = sizeof(bpf_event.event_id),
9306 .id = prog->aux->id,
9310 BUILD_BUG_ON(BPF_TAG_SIZE % sizeof(u64));
9312 memcpy(bpf_event.event_id.tag, prog->tag, BPF_TAG_SIZE);
9313 perf_iterate_sb(perf_event_bpf_output, &bpf_event, NULL);
9316 struct perf_text_poke_event {
9317 const void *old_bytes;
9318 const void *new_bytes;
9324 struct perf_event_header header;
9330 static int perf_event_text_poke_match(struct perf_event *event)
9332 return event->attr.text_poke;
9335 static void perf_event_text_poke_output(struct perf_event *event, void *data)
9337 struct perf_text_poke_event *text_poke_event = data;
9338 struct perf_output_handle handle;
9339 struct perf_sample_data sample;
9343 if (!perf_event_text_poke_match(event))
9346 perf_event_header__init_id(&text_poke_event->event_id.header, &sample, event);
9348 ret = perf_output_begin(&handle, &sample, event,
9349 text_poke_event->event_id.header.size);
9353 perf_output_put(&handle, text_poke_event->event_id);
9354 perf_output_put(&handle, text_poke_event->old_len);
9355 perf_output_put(&handle, text_poke_event->new_len);
9357 __output_copy(&handle, text_poke_event->old_bytes, text_poke_event->old_len);
9358 __output_copy(&handle, text_poke_event->new_bytes, text_poke_event->new_len);
9360 if (text_poke_event->pad)
9361 __output_copy(&handle, &padding, text_poke_event->pad);
9363 perf_event__output_id_sample(event, &handle, &sample);
9365 perf_output_end(&handle);
9368 void perf_event_text_poke(const void *addr, const void *old_bytes,
9369 size_t old_len, const void *new_bytes, size_t new_len)
9371 struct perf_text_poke_event text_poke_event;
9374 if (!atomic_read(&nr_text_poke_events))
9377 tot = sizeof(text_poke_event.old_len) + old_len;
9378 tot += sizeof(text_poke_event.new_len) + new_len;
9379 pad = ALIGN(tot, sizeof(u64)) - tot;
9381 text_poke_event = (struct perf_text_poke_event){
9382 .old_bytes = old_bytes,
9383 .new_bytes = new_bytes,
9389 .type = PERF_RECORD_TEXT_POKE,
9390 .misc = PERF_RECORD_MISC_KERNEL,
9391 .size = sizeof(text_poke_event.event_id) + tot + pad,
9393 .addr = (unsigned long)addr,
9397 perf_iterate_sb(perf_event_text_poke_output, &text_poke_event, NULL);
9400 void perf_event_itrace_started(struct perf_event *event)
9402 event->attach_state |= PERF_ATTACH_ITRACE;
9405 static void perf_log_itrace_start(struct perf_event *event)
9407 struct perf_output_handle handle;
9408 struct perf_sample_data sample;
9409 struct perf_aux_event {
9410 struct perf_event_header header;
9417 event = event->parent;
9419 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
9420 event->attach_state & PERF_ATTACH_ITRACE)
9423 rec.header.type = PERF_RECORD_ITRACE_START;
9424 rec.header.misc = 0;
9425 rec.header.size = sizeof(rec);
9426 rec.pid = perf_event_pid(event, current);
9427 rec.tid = perf_event_tid(event, current);
9429 perf_event_header__init_id(&rec.header, &sample, event);
9430 ret = perf_output_begin(&handle, &sample, event, rec.header.size);
9435 perf_output_put(&handle, rec);
9436 perf_event__output_id_sample(event, &handle, &sample);
9438 perf_output_end(&handle);
9441 void perf_report_aux_output_id(struct perf_event *event, u64 hw_id)
9443 struct perf_output_handle handle;
9444 struct perf_sample_data sample;
9445 struct perf_aux_event {
9446 struct perf_event_header header;
9452 event = event->parent;
9454 rec.header.type = PERF_RECORD_AUX_OUTPUT_HW_ID;
9455 rec.header.misc = 0;
9456 rec.header.size = sizeof(rec);
9459 perf_event_header__init_id(&rec.header, &sample, event);
9460 ret = perf_output_begin(&handle, &sample, event, rec.header.size);
9465 perf_output_put(&handle, rec);
9466 perf_event__output_id_sample(event, &handle, &sample);
9468 perf_output_end(&handle);
9470 EXPORT_SYMBOL_GPL(perf_report_aux_output_id);
9473 __perf_event_account_interrupt(struct perf_event *event, int throttle)
9475 struct hw_perf_event *hwc = &event->hw;
9479 seq = __this_cpu_read(perf_throttled_seq);
9480 if (seq != hwc->interrupts_seq) {
9481 hwc->interrupts_seq = seq;
9482 hwc->interrupts = 1;
9485 if (unlikely(throttle &&
9486 hwc->interrupts > max_samples_per_tick)) {
9487 __this_cpu_inc(perf_throttled_count);
9488 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
9489 hwc->interrupts = MAX_INTERRUPTS;
9490 perf_log_throttle(event, 0);
9495 if (event->attr.freq) {
9496 u64 now = perf_clock();
9497 s64 delta = now - hwc->freq_time_stamp;
9499 hwc->freq_time_stamp = now;
9501 if (delta > 0 && delta < 2*TICK_NSEC)
9502 perf_adjust_period(event, delta, hwc->last_period, true);
9508 int perf_event_account_interrupt(struct perf_event *event)
9510 return __perf_event_account_interrupt(event, 1);
9513 static inline bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs)
9516 * Due to interrupt latency (AKA "skid"), we may enter the
9517 * kernel before taking an overflow, even if the PMU is only
9518 * counting user events.
9520 if (event->attr.exclude_kernel && !user_mode(regs))
9527 * Generic event overflow handling, sampling.
9530 static int __perf_event_overflow(struct perf_event *event,
9531 int throttle, struct perf_sample_data *data,
9532 struct pt_regs *regs)
9534 int events = atomic_read(&event->event_limit);
9538 * Non-sampling counters might still use the PMI to fold short
9539 * hardware counters, ignore those.
9541 if (unlikely(!is_sampling_event(event)))
9544 ret = __perf_event_account_interrupt(event, throttle);
9547 * XXX event_limit might not quite work as expected on inherited
9551 event->pending_kill = POLL_IN;
9552 if (events && atomic_dec_and_test(&event->event_limit)) {
9554 event->pending_kill = POLL_HUP;
9555 perf_event_disable_inatomic(event);
9558 if (event->attr.sigtrap) {
9560 * The desired behaviour of sigtrap vs invalid samples is a bit
9561 * tricky; on the one hand, one should not loose the SIGTRAP if
9562 * it is the first event, on the other hand, we should also not
9563 * trigger the WARN or override the data address.
9565 bool valid_sample = sample_is_allowed(event, regs);
9566 unsigned int pending_id = 1;
9569 pending_id = hash32_ptr((void *)instruction_pointer(regs)) ?: 1;
9570 if (!event->pending_sigtrap) {
9571 event->pending_sigtrap = pending_id;
9572 local_inc(&event->ctx->nr_pending);
9573 } else if (event->attr.exclude_kernel && valid_sample) {
9575 * Should not be able to return to user space without
9576 * consuming pending_sigtrap; with exceptions:
9578 * 1. Where !exclude_kernel, events can overflow again
9579 * in the kernel without returning to user space.
9581 * 2. Events that can overflow again before the IRQ-
9582 * work without user space progress (e.g. hrtimer).
9583 * To approximate progress (with false negatives),
9584 * check 32-bit hash of the current IP.
9586 WARN_ON_ONCE(event->pending_sigtrap != pending_id);
9589 event->pending_addr = 0;
9590 if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))
9591 event->pending_addr = data->addr;
9592 irq_work_queue(&event->pending_irq);
9595 READ_ONCE(event->overflow_handler)(event, data, regs);
9597 if (*perf_event_fasync(event) && event->pending_kill) {
9598 event->pending_wakeup = 1;
9599 irq_work_queue(&event->pending_irq);
9605 int perf_event_overflow(struct perf_event *event,
9606 struct perf_sample_data *data,
9607 struct pt_regs *regs)
9609 return __perf_event_overflow(event, 1, data, regs);
9613 * Generic software event infrastructure
9616 struct swevent_htable {
9617 struct swevent_hlist *swevent_hlist;
9618 struct mutex hlist_mutex;
9621 /* Recursion avoidance in each contexts */
9622 int recursion[PERF_NR_CONTEXTS];
9625 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
9628 * We directly increment event->count and keep a second value in
9629 * event->hw.period_left to count intervals. This period event
9630 * is kept in the range [-sample_period, 0] so that we can use the
9634 u64 perf_swevent_set_period(struct perf_event *event)
9636 struct hw_perf_event *hwc = &event->hw;
9637 u64 period = hwc->last_period;
9641 hwc->last_period = hwc->sample_period;
9643 old = local64_read(&hwc->period_left);
9649 nr = div64_u64(period + val, period);
9650 offset = nr * period;
9652 } while (!local64_try_cmpxchg(&hwc->period_left, &old, val));
9657 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
9658 struct perf_sample_data *data,
9659 struct pt_regs *regs)
9661 struct hw_perf_event *hwc = &event->hw;
9665 overflow = perf_swevent_set_period(event);
9667 if (hwc->interrupts == MAX_INTERRUPTS)
9670 for (; overflow; overflow--) {
9671 if (__perf_event_overflow(event, throttle,
9674 * We inhibit the overflow from happening when
9675 * hwc->interrupts == MAX_INTERRUPTS.
9683 static void perf_swevent_event(struct perf_event *event, u64 nr,
9684 struct perf_sample_data *data,
9685 struct pt_regs *regs)
9687 struct hw_perf_event *hwc = &event->hw;
9689 local64_add(nr, &event->count);
9694 if (!is_sampling_event(event))
9697 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
9699 return perf_swevent_overflow(event, 1, data, regs);
9701 data->period = event->hw.last_period;
9703 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
9704 return perf_swevent_overflow(event, 1, data, regs);
9706 if (local64_add_negative(nr, &hwc->period_left))
9709 perf_swevent_overflow(event, 0, data, regs);
9712 static int perf_exclude_event(struct perf_event *event,
9713 struct pt_regs *regs)
9715 if (event->hw.state & PERF_HES_STOPPED)
9719 if (event->attr.exclude_user && user_mode(regs))
9722 if (event->attr.exclude_kernel && !user_mode(regs))
9729 static int perf_swevent_match(struct perf_event *event,
9730 enum perf_type_id type,
9732 struct perf_sample_data *data,
9733 struct pt_regs *regs)
9735 if (event->attr.type != type)
9738 if (event->attr.config != event_id)
9741 if (perf_exclude_event(event, regs))
9747 static inline u64 swevent_hash(u64 type, u32 event_id)
9749 u64 val = event_id | (type << 32);
9751 return hash_64(val, SWEVENT_HLIST_BITS);
9754 static inline struct hlist_head *
9755 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
9757 u64 hash = swevent_hash(type, event_id);
9759 return &hlist->heads[hash];
9762 /* For the read side: events when they trigger */
9763 static inline struct hlist_head *
9764 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
9766 struct swevent_hlist *hlist;
9768 hlist = rcu_dereference(swhash->swevent_hlist);
9772 return __find_swevent_head(hlist, type, event_id);
9775 /* For the event head insertion and removal in the hlist */
9776 static inline struct hlist_head *
9777 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
9779 struct swevent_hlist *hlist;
9780 u32 event_id = event->attr.config;
9781 u64 type = event->attr.type;
9784 * Event scheduling is always serialized against hlist allocation
9785 * and release. Which makes the protected version suitable here.
9786 * The context lock guarantees that.
9788 hlist = rcu_dereference_protected(swhash->swevent_hlist,
9789 lockdep_is_held(&event->ctx->lock));
9793 return __find_swevent_head(hlist, type, event_id);
9796 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
9798 struct perf_sample_data *data,
9799 struct pt_regs *regs)
9801 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
9802 struct perf_event *event;
9803 struct hlist_head *head;
9806 head = find_swevent_head_rcu(swhash, type, event_id);
9810 hlist_for_each_entry_rcu(event, head, hlist_entry) {
9811 if (perf_swevent_match(event, type, event_id, data, regs))
9812 perf_swevent_event(event, nr, data, regs);
9818 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
9820 int perf_swevent_get_recursion_context(void)
9822 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
9824 return get_recursion_context(swhash->recursion);
9826 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
9828 void perf_swevent_put_recursion_context(int rctx)
9830 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
9832 put_recursion_context(swhash->recursion, rctx);
9835 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
9837 struct perf_sample_data data;
9839 if (WARN_ON_ONCE(!regs))
9842 perf_sample_data_init(&data, addr, 0);
9843 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
9846 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
9850 preempt_disable_notrace();
9851 rctx = perf_swevent_get_recursion_context();
9852 if (unlikely(rctx < 0))
9855 ___perf_sw_event(event_id, nr, regs, addr);
9857 perf_swevent_put_recursion_context(rctx);
9859 preempt_enable_notrace();
9862 static void perf_swevent_read(struct perf_event *event)
9866 static int perf_swevent_add(struct perf_event *event, int flags)
9868 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
9869 struct hw_perf_event *hwc = &event->hw;
9870 struct hlist_head *head;
9872 if (is_sampling_event(event)) {
9873 hwc->last_period = hwc->sample_period;
9874 perf_swevent_set_period(event);
9877 hwc->state = !(flags & PERF_EF_START);
9879 head = find_swevent_head(swhash, event);
9880 if (WARN_ON_ONCE(!head))
9883 hlist_add_head_rcu(&event->hlist_entry, head);
9884 perf_event_update_userpage(event);
9889 static void perf_swevent_del(struct perf_event *event, int flags)
9891 hlist_del_rcu(&event->hlist_entry);
9894 static void perf_swevent_start(struct perf_event *event, int flags)
9896 event->hw.state = 0;
9899 static void perf_swevent_stop(struct perf_event *event, int flags)
9901 event->hw.state = PERF_HES_STOPPED;
9904 /* Deref the hlist from the update side */
9905 static inline struct swevent_hlist *
9906 swevent_hlist_deref(struct swevent_htable *swhash)
9908 return rcu_dereference_protected(swhash->swevent_hlist,
9909 lockdep_is_held(&swhash->hlist_mutex));
9912 static void swevent_hlist_release(struct swevent_htable *swhash)
9914 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
9919 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
9920 kfree_rcu(hlist, rcu_head);
9923 static void swevent_hlist_put_cpu(int cpu)
9925 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
9927 mutex_lock(&swhash->hlist_mutex);
9929 if (!--swhash->hlist_refcount)
9930 swevent_hlist_release(swhash);
9932 mutex_unlock(&swhash->hlist_mutex);
9935 static void swevent_hlist_put(void)
9939 for_each_possible_cpu(cpu)
9940 swevent_hlist_put_cpu(cpu);
9943 static int swevent_hlist_get_cpu(int cpu)
9945 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
9948 mutex_lock(&swhash->hlist_mutex);
9949 if (!swevent_hlist_deref(swhash) &&
9950 cpumask_test_cpu(cpu, perf_online_mask)) {
9951 struct swevent_hlist *hlist;
9953 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
9958 rcu_assign_pointer(swhash->swevent_hlist, hlist);
9960 swhash->hlist_refcount++;
9962 mutex_unlock(&swhash->hlist_mutex);
9967 static int swevent_hlist_get(void)
9969 int err, cpu, failed_cpu;
9971 mutex_lock(&pmus_lock);
9972 for_each_possible_cpu(cpu) {
9973 err = swevent_hlist_get_cpu(cpu);
9979 mutex_unlock(&pmus_lock);
9982 for_each_possible_cpu(cpu) {
9983 if (cpu == failed_cpu)
9985 swevent_hlist_put_cpu(cpu);
9987 mutex_unlock(&pmus_lock);
9991 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
9993 static void sw_perf_event_destroy(struct perf_event *event)
9995 u64 event_id = event->attr.config;
9997 WARN_ON(event->parent);
9999 static_key_slow_dec(&perf_swevent_enabled[event_id]);
10000 swevent_hlist_put();
10003 static struct pmu perf_cpu_clock; /* fwd declaration */
10004 static struct pmu perf_task_clock;
10006 static int perf_swevent_init(struct perf_event *event)
10008 u64 event_id = event->attr.config;
10010 if (event->attr.type != PERF_TYPE_SOFTWARE)
10014 * no branch sampling for software events
10016 if (has_branch_stack(event))
10017 return -EOPNOTSUPP;
10019 switch (event_id) {
10020 case PERF_COUNT_SW_CPU_CLOCK:
10021 event->attr.type = perf_cpu_clock.type;
10023 case PERF_COUNT_SW_TASK_CLOCK:
10024 event->attr.type = perf_task_clock.type;
10031 if (event_id >= PERF_COUNT_SW_MAX)
10034 if (!event->parent) {
10037 err = swevent_hlist_get();
10041 static_key_slow_inc(&perf_swevent_enabled[event_id]);
10042 event->destroy = sw_perf_event_destroy;
10048 static struct pmu perf_swevent = {
10049 .task_ctx_nr = perf_sw_context,
10051 .capabilities = PERF_PMU_CAP_NO_NMI,
10053 .event_init = perf_swevent_init,
10054 .add = perf_swevent_add,
10055 .del = perf_swevent_del,
10056 .start = perf_swevent_start,
10057 .stop = perf_swevent_stop,
10058 .read = perf_swevent_read,
10061 #ifdef CONFIG_EVENT_TRACING
10063 static void tp_perf_event_destroy(struct perf_event *event)
10065 perf_trace_destroy(event);
10068 static int perf_tp_event_init(struct perf_event *event)
10072 if (event->attr.type != PERF_TYPE_TRACEPOINT)
10076 * no branch sampling for tracepoint events
10078 if (has_branch_stack(event))
10079 return -EOPNOTSUPP;
10081 err = perf_trace_init(event);
10085 event->destroy = tp_perf_event_destroy;
10090 static struct pmu perf_tracepoint = {
10091 .task_ctx_nr = perf_sw_context,
10093 .event_init = perf_tp_event_init,
10094 .add = perf_trace_add,
10095 .del = perf_trace_del,
10096 .start = perf_swevent_start,
10097 .stop = perf_swevent_stop,
10098 .read = perf_swevent_read,
10101 static int perf_tp_filter_match(struct perf_event *event,
10102 struct perf_sample_data *data)
10104 void *record = data->raw->frag.data;
10106 /* only top level events have filters set */
10108 event = event->parent;
10110 if (likely(!event->filter) || filter_match_preds(event->filter, record))
10115 static int perf_tp_event_match(struct perf_event *event,
10116 struct perf_sample_data *data,
10117 struct pt_regs *regs)
10119 if (event->hw.state & PERF_HES_STOPPED)
10122 * If exclude_kernel, only trace user-space tracepoints (uprobes)
10124 if (event->attr.exclude_kernel && !user_mode(regs))
10127 if (!perf_tp_filter_match(event, data))
10133 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
10134 struct trace_event_call *call, u64 count,
10135 struct pt_regs *regs, struct hlist_head *head,
10136 struct task_struct *task)
10138 if (bpf_prog_array_valid(call)) {
10139 *(struct pt_regs **)raw_data = regs;
10140 if (!trace_call_bpf(call, raw_data) || hlist_empty(head)) {
10141 perf_swevent_put_recursion_context(rctx);
10145 perf_tp_event(call->event.type, count, raw_data, size, regs, head,
10148 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
10150 static void __perf_tp_event_target_task(u64 count, void *record,
10151 struct pt_regs *regs,
10152 struct perf_sample_data *data,
10153 struct perf_event *event)
10155 struct trace_entry *entry = record;
10157 if (event->attr.config != entry->type)
10159 /* Cannot deliver synchronous signal to other task. */
10160 if (event->attr.sigtrap)
10162 if (perf_tp_event_match(event, data, regs))
10163 perf_swevent_event(event, count, data, regs);
10166 static void perf_tp_event_target_task(u64 count, void *record,
10167 struct pt_regs *regs,
10168 struct perf_sample_data *data,
10169 struct perf_event_context *ctx)
10171 unsigned int cpu = smp_processor_id();
10172 struct pmu *pmu = &perf_tracepoint;
10173 struct perf_event *event, *sibling;
10175 perf_event_groups_for_cpu_pmu(event, &ctx->pinned_groups, cpu, pmu) {
10176 __perf_tp_event_target_task(count, record, regs, data, event);
10177 for_each_sibling_event(sibling, event)
10178 __perf_tp_event_target_task(count, record, regs, data, sibling);
10181 perf_event_groups_for_cpu_pmu(event, &ctx->flexible_groups, cpu, pmu) {
10182 __perf_tp_event_target_task(count, record, regs, data, event);
10183 for_each_sibling_event(sibling, event)
10184 __perf_tp_event_target_task(count, record, regs, data, sibling);
10188 void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
10189 struct pt_regs *regs, struct hlist_head *head, int rctx,
10190 struct task_struct *task)
10192 struct perf_sample_data data;
10193 struct perf_event *event;
10195 struct perf_raw_record raw = {
10197 .size = entry_size,
10202 perf_sample_data_init(&data, 0, 0);
10203 perf_sample_save_raw_data(&data, &raw);
10205 perf_trace_buf_update(record, event_type);
10207 hlist_for_each_entry_rcu(event, head, hlist_entry) {
10208 if (perf_tp_event_match(event, &data, regs)) {
10209 perf_swevent_event(event, count, &data, regs);
10212 * Here use the same on-stack perf_sample_data,
10213 * some members in data are event-specific and
10214 * need to be re-computed for different sweveents.
10215 * Re-initialize data->sample_flags safely to avoid
10216 * the problem that next event skips preparing data
10217 * because data->sample_flags is set.
10219 perf_sample_data_init(&data, 0, 0);
10220 perf_sample_save_raw_data(&data, &raw);
10225 * If we got specified a target task, also iterate its context and
10226 * deliver this event there too.
10228 if (task && task != current) {
10229 struct perf_event_context *ctx;
10232 ctx = rcu_dereference(task->perf_event_ctxp);
10236 raw_spin_lock(&ctx->lock);
10237 perf_tp_event_target_task(count, record, regs, &data, ctx);
10238 raw_spin_unlock(&ctx->lock);
10243 perf_swevent_put_recursion_context(rctx);
10245 EXPORT_SYMBOL_GPL(perf_tp_event);
10247 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
10249 * Flags in config, used by dynamic PMU kprobe and uprobe
10250 * The flags should match following PMU_FORMAT_ATTR().
10252 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
10253 * if not set, create kprobe/uprobe
10255 * The following values specify a reference counter (or semaphore in the
10256 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
10257 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
10259 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
10260 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
10262 enum perf_probe_config {
10263 PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */
10264 PERF_UPROBE_REF_CTR_OFFSET_BITS = 32,
10265 PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS,
10268 PMU_FORMAT_ATTR(retprobe, "config:0");
10271 #ifdef CONFIG_KPROBE_EVENTS
10272 static struct attribute *kprobe_attrs[] = {
10273 &format_attr_retprobe.attr,
10277 static struct attribute_group kprobe_format_group = {
10279 .attrs = kprobe_attrs,
10282 static const struct attribute_group *kprobe_attr_groups[] = {
10283 &kprobe_format_group,
10287 static int perf_kprobe_event_init(struct perf_event *event);
10288 static struct pmu perf_kprobe = {
10289 .task_ctx_nr = perf_sw_context,
10290 .event_init = perf_kprobe_event_init,
10291 .add = perf_trace_add,
10292 .del = perf_trace_del,
10293 .start = perf_swevent_start,
10294 .stop = perf_swevent_stop,
10295 .read = perf_swevent_read,
10296 .attr_groups = kprobe_attr_groups,
10299 static int perf_kprobe_event_init(struct perf_event *event)
10304 if (event->attr.type != perf_kprobe.type)
10307 if (!perfmon_capable())
10311 * no branch sampling for probe events
10313 if (has_branch_stack(event))
10314 return -EOPNOTSUPP;
10316 is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
10317 err = perf_kprobe_init(event, is_retprobe);
10321 event->destroy = perf_kprobe_destroy;
10325 #endif /* CONFIG_KPROBE_EVENTS */
10327 #ifdef CONFIG_UPROBE_EVENTS
10328 PMU_FORMAT_ATTR(ref_ctr_offset, "config:32-63");
10330 static struct attribute *uprobe_attrs[] = {
10331 &format_attr_retprobe.attr,
10332 &format_attr_ref_ctr_offset.attr,
10336 static struct attribute_group uprobe_format_group = {
10338 .attrs = uprobe_attrs,
10341 static const struct attribute_group *uprobe_attr_groups[] = {
10342 &uprobe_format_group,
10346 static int perf_uprobe_event_init(struct perf_event *event);
10347 static struct pmu perf_uprobe = {
10348 .task_ctx_nr = perf_sw_context,
10349 .event_init = perf_uprobe_event_init,
10350 .add = perf_trace_add,
10351 .del = perf_trace_del,
10352 .start = perf_swevent_start,
10353 .stop = perf_swevent_stop,
10354 .read = perf_swevent_read,
10355 .attr_groups = uprobe_attr_groups,
10358 static int perf_uprobe_event_init(struct perf_event *event)
10361 unsigned long ref_ctr_offset;
10364 if (event->attr.type != perf_uprobe.type)
10367 if (!perfmon_capable())
10371 * no branch sampling for probe events
10373 if (has_branch_stack(event))
10374 return -EOPNOTSUPP;
10376 is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
10377 ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
10378 err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe);
10382 event->destroy = perf_uprobe_destroy;
10386 #endif /* CONFIG_UPROBE_EVENTS */
10388 static inline void perf_tp_register(void)
10390 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
10391 #ifdef CONFIG_KPROBE_EVENTS
10392 perf_pmu_register(&perf_kprobe, "kprobe", -1);
10394 #ifdef CONFIG_UPROBE_EVENTS
10395 perf_pmu_register(&perf_uprobe, "uprobe", -1);
10399 static void perf_event_free_filter(struct perf_event *event)
10401 ftrace_profile_free_filter(event);
10404 #ifdef CONFIG_BPF_SYSCALL
10405 static void bpf_overflow_handler(struct perf_event *event,
10406 struct perf_sample_data *data,
10407 struct pt_regs *regs)
10409 struct bpf_perf_event_data_kern ctx = {
10413 struct bpf_prog *prog;
10416 ctx.regs = perf_arch_bpf_user_pt_regs(regs);
10417 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
10420 prog = READ_ONCE(event->prog);
10422 perf_prepare_sample(data, event, regs);
10423 ret = bpf_prog_run(prog, &ctx);
10427 __this_cpu_dec(bpf_prog_active);
10431 event->orig_overflow_handler(event, data, regs);
10434 static int perf_event_set_bpf_handler(struct perf_event *event,
10435 struct bpf_prog *prog,
10438 if (event->overflow_handler_context)
10439 /* hw breakpoint or kernel counter */
10445 if (prog->type != BPF_PROG_TYPE_PERF_EVENT)
10448 if (event->attr.precise_ip &&
10449 prog->call_get_stack &&
10450 (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) ||
10451 event->attr.exclude_callchain_kernel ||
10452 event->attr.exclude_callchain_user)) {
10454 * On perf_event with precise_ip, calling bpf_get_stack()
10455 * may trigger unwinder warnings and occasional crashes.
10456 * bpf_get_[stack|stackid] works around this issue by using
10457 * callchain attached to perf_sample_data. If the
10458 * perf_event does not full (kernel and user) callchain
10459 * attached to perf_sample_data, do not allow attaching BPF
10460 * program that calls bpf_get_[stack|stackid].
10465 event->prog = prog;
10466 event->bpf_cookie = bpf_cookie;
10467 event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
10468 WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
10472 static void perf_event_free_bpf_handler(struct perf_event *event)
10474 struct bpf_prog *prog = event->prog;
10479 WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler);
10480 event->prog = NULL;
10481 bpf_prog_put(prog);
10484 static int perf_event_set_bpf_handler(struct perf_event *event,
10485 struct bpf_prog *prog,
10488 return -EOPNOTSUPP;
10490 static void perf_event_free_bpf_handler(struct perf_event *event)
10496 * returns true if the event is a tracepoint, or a kprobe/upprobe created
10497 * with perf_event_open()
10499 static inline bool perf_event_is_tracing(struct perf_event *event)
10501 if (event->pmu == &perf_tracepoint)
10503 #ifdef CONFIG_KPROBE_EVENTS
10504 if (event->pmu == &perf_kprobe)
10507 #ifdef CONFIG_UPROBE_EVENTS
10508 if (event->pmu == &perf_uprobe)
10514 int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog,
10517 bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp;
10519 if (!perf_event_is_tracing(event))
10520 return perf_event_set_bpf_handler(event, prog, bpf_cookie);
10522 is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE;
10523 is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE;
10524 is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
10525 is_syscall_tp = is_syscall_trace_event(event->tp_event);
10526 if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp)
10527 /* bpf programs can only be attached to u/kprobe or tracepoint */
10530 if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) ||
10531 (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) ||
10532 (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT))
10535 if (prog->type == BPF_PROG_TYPE_KPROBE && prog->aux->sleepable && !is_uprobe)
10536 /* only uprobe programs are allowed to be sleepable */
10539 /* Kprobe override only works for kprobes, not uprobes. */
10540 if (prog->kprobe_override && !is_kprobe)
10543 if (is_tracepoint || is_syscall_tp) {
10544 int off = trace_event_get_offsets(event->tp_event);
10546 if (prog->aux->max_ctx_offset > off)
10550 return perf_event_attach_bpf_prog(event, prog, bpf_cookie);
10553 void perf_event_free_bpf_prog(struct perf_event *event)
10555 if (!perf_event_is_tracing(event)) {
10556 perf_event_free_bpf_handler(event);
10559 perf_event_detach_bpf_prog(event);
10564 static inline void perf_tp_register(void)
10568 static void perf_event_free_filter(struct perf_event *event)
10572 int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog,
10578 void perf_event_free_bpf_prog(struct perf_event *event)
10581 #endif /* CONFIG_EVENT_TRACING */
10583 #ifdef CONFIG_HAVE_HW_BREAKPOINT
10584 void perf_bp_event(struct perf_event *bp, void *data)
10586 struct perf_sample_data sample;
10587 struct pt_regs *regs = data;
10589 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
10591 if (!bp->hw.state && !perf_exclude_event(bp, regs))
10592 perf_swevent_event(bp, 1, &sample, regs);
10597 * Allocate a new address filter
10599 static struct perf_addr_filter *
10600 perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
10602 int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
10603 struct perf_addr_filter *filter;
10605 filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
10609 INIT_LIST_HEAD(&filter->entry);
10610 list_add_tail(&filter->entry, filters);
10615 static void free_filters_list(struct list_head *filters)
10617 struct perf_addr_filter *filter, *iter;
10619 list_for_each_entry_safe(filter, iter, filters, entry) {
10620 path_put(&filter->path);
10621 list_del(&filter->entry);
10627 * Free existing address filters and optionally install new ones
10629 static void perf_addr_filters_splice(struct perf_event *event,
10630 struct list_head *head)
10632 unsigned long flags;
10635 if (!has_addr_filter(event))
10638 /* don't bother with children, they don't have their own filters */
10642 raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
10644 list_splice_init(&event->addr_filters.list, &list);
10646 list_splice(head, &event->addr_filters.list);
10648 raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
10650 free_filters_list(&list);
10654 * Scan through mm's vmas and see if one of them matches the
10655 * @filter; if so, adjust filter's address range.
10656 * Called with mm::mmap_lock down for reading.
10658 static void perf_addr_filter_apply(struct perf_addr_filter *filter,
10659 struct mm_struct *mm,
10660 struct perf_addr_filter_range *fr)
10662 struct vm_area_struct *vma;
10663 VMA_ITERATOR(vmi, mm, 0);
10665 for_each_vma(vmi, vma) {
10669 if (perf_addr_filter_vma_adjust(filter, vma, fr))
10675 * Update event's address range filters based on the
10676 * task's existing mappings, if any.
10678 static void perf_event_addr_filters_apply(struct perf_event *event)
10680 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
10681 struct task_struct *task = READ_ONCE(event->ctx->task);
10682 struct perf_addr_filter *filter;
10683 struct mm_struct *mm = NULL;
10684 unsigned int count = 0;
10685 unsigned long flags;
10688 * We may observe TASK_TOMBSTONE, which means that the event tear-down
10689 * will stop on the parent's child_mutex that our caller is also holding
10691 if (task == TASK_TOMBSTONE)
10694 if (ifh->nr_file_filters) {
10695 mm = get_task_mm(task);
10699 mmap_read_lock(mm);
10702 raw_spin_lock_irqsave(&ifh->lock, flags);
10703 list_for_each_entry(filter, &ifh->list, entry) {
10704 if (filter->path.dentry) {
10706 * Adjust base offset if the filter is associated to a
10707 * binary that needs to be mapped:
10709 event->addr_filter_ranges[count].start = 0;
10710 event->addr_filter_ranges[count].size = 0;
10712 perf_addr_filter_apply(filter, mm, &event->addr_filter_ranges[count]);
10714 event->addr_filter_ranges[count].start = filter->offset;
10715 event->addr_filter_ranges[count].size = filter->size;
10721 event->addr_filters_gen++;
10722 raw_spin_unlock_irqrestore(&ifh->lock, flags);
10724 if (ifh->nr_file_filters) {
10725 mmap_read_unlock(mm);
10731 perf_event_stop(event, 1);
10735 * Address range filtering: limiting the data to certain
10736 * instruction address ranges. Filters are ioctl()ed to us from
10737 * userspace as ascii strings.
10739 * Filter string format:
10741 * ACTION RANGE_SPEC
10742 * where ACTION is one of the
10743 * * "filter": limit the trace to this region
10744 * * "start": start tracing from this address
10745 * * "stop": stop tracing at this address/region;
10747 * * for kernel addresses: <start address>[/<size>]
10748 * * for object files: <start address>[/<size>]@</path/to/object/file>
10750 * if <size> is not specified or is zero, the range is treated as a single
10751 * address; not valid for ACTION=="filter".
10765 IF_STATE_ACTION = 0,
10770 static const match_table_t if_tokens = {
10771 { IF_ACT_FILTER, "filter" },
10772 { IF_ACT_START, "start" },
10773 { IF_ACT_STOP, "stop" },
10774 { IF_SRC_FILE, "%u/%u@%s" },
10775 { IF_SRC_KERNEL, "%u/%u" },
10776 { IF_SRC_FILEADDR, "%u@%s" },
10777 { IF_SRC_KERNELADDR, "%u" },
10778 { IF_ACT_NONE, NULL },
10782 * Address filter string parser
10785 perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
10786 struct list_head *filters)
10788 struct perf_addr_filter *filter = NULL;
10789 char *start, *orig, *filename = NULL;
10790 substring_t args[MAX_OPT_ARGS];
10791 int state = IF_STATE_ACTION, token;
10792 unsigned int kernel = 0;
10795 orig = fstr = kstrdup(fstr, GFP_KERNEL);
10799 while ((start = strsep(&fstr, " ,\n")) != NULL) {
10800 static const enum perf_addr_filter_action_t actions[] = {
10801 [IF_ACT_FILTER] = PERF_ADDR_FILTER_ACTION_FILTER,
10802 [IF_ACT_START] = PERF_ADDR_FILTER_ACTION_START,
10803 [IF_ACT_STOP] = PERF_ADDR_FILTER_ACTION_STOP,
10810 /* filter definition begins */
10811 if (state == IF_STATE_ACTION) {
10812 filter = perf_addr_filter_new(event, filters);
10817 token = match_token(start, if_tokens, args);
10819 case IF_ACT_FILTER:
10822 if (state != IF_STATE_ACTION)
10825 filter->action = actions[token];
10826 state = IF_STATE_SOURCE;
10829 case IF_SRC_KERNELADDR:
10830 case IF_SRC_KERNEL:
10834 case IF_SRC_FILEADDR:
10836 if (state != IF_STATE_SOURCE)
10840 ret = kstrtoul(args[0].from, 0, &filter->offset);
10844 if (token == IF_SRC_KERNEL || token == IF_SRC_FILE) {
10846 ret = kstrtoul(args[1].from, 0, &filter->size);
10851 if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
10852 int fpos = token == IF_SRC_FILE ? 2 : 1;
10855 filename = match_strdup(&args[fpos]);
10862 state = IF_STATE_END;
10870 * Filter definition is fully parsed, validate and install it.
10871 * Make sure that it doesn't contradict itself or the event's
10874 if (state == IF_STATE_END) {
10878 * ACTION "filter" must have a non-zero length region
10881 if (filter->action == PERF_ADDR_FILTER_ACTION_FILTER &&
10890 * For now, we only support file-based filters
10891 * in per-task events; doing so for CPU-wide
10892 * events requires additional context switching
10893 * trickery, since same object code will be
10894 * mapped at different virtual addresses in
10895 * different processes.
10898 if (!event->ctx->task)
10901 /* look up the path and grab its inode */
10902 ret = kern_path(filename, LOOKUP_FOLLOW,
10908 if (!filter->path.dentry ||
10909 !S_ISREG(d_inode(filter->path.dentry)
10913 event->addr_filters.nr_file_filters++;
10916 /* ready to consume more filters */
10919 state = IF_STATE_ACTION;
10925 if (state != IF_STATE_ACTION)
10935 free_filters_list(filters);
10942 perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
10944 LIST_HEAD(filters);
10948 * Since this is called in perf_ioctl() path, we're already holding
10951 lockdep_assert_held(&event->ctx->mutex);
10953 if (WARN_ON_ONCE(event->parent))
10956 ret = perf_event_parse_addr_filter(event, filter_str, &filters);
10958 goto fail_clear_files;
10960 ret = event->pmu->addr_filters_validate(&filters);
10962 goto fail_free_filters;
10964 /* remove existing filters, if any */
10965 perf_addr_filters_splice(event, &filters);
10967 /* install new filters */
10968 perf_event_for_each_child(event, perf_event_addr_filters_apply);
10973 free_filters_list(&filters);
10976 event->addr_filters.nr_file_filters = 0;
10981 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
10986 filter_str = strndup_user(arg, PAGE_SIZE);
10987 if (IS_ERR(filter_str))
10988 return PTR_ERR(filter_str);
10990 #ifdef CONFIG_EVENT_TRACING
10991 if (perf_event_is_tracing(event)) {
10992 struct perf_event_context *ctx = event->ctx;
10995 * Beware, here be dragons!!
10997 * the tracepoint muck will deadlock against ctx->mutex, but
10998 * the tracepoint stuff does not actually need it. So
10999 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
11000 * already have a reference on ctx.
11002 * This can result in event getting moved to a different ctx,
11003 * but that does not affect the tracepoint state.
11005 mutex_unlock(&ctx->mutex);
11006 ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
11007 mutex_lock(&ctx->mutex);
11010 if (has_addr_filter(event))
11011 ret = perf_event_set_addr_filter(event, filter_str);
11018 * hrtimer based swevent callback
11021 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
11023 enum hrtimer_restart ret = HRTIMER_RESTART;
11024 struct perf_sample_data data;
11025 struct pt_regs *regs;
11026 struct perf_event *event;
11029 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
11031 if (event->state != PERF_EVENT_STATE_ACTIVE)
11032 return HRTIMER_NORESTART;
11034 event->pmu->read(event);
11036 perf_sample_data_init(&data, 0, event->hw.last_period);
11037 regs = get_irq_regs();
11039 if (regs && !perf_exclude_event(event, regs)) {
11040 if (!(event->attr.exclude_idle && is_idle_task(current)))
11041 if (__perf_event_overflow(event, 1, &data, regs))
11042 ret = HRTIMER_NORESTART;
11045 period = max_t(u64, 10000, event->hw.sample_period);
11046 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
11051 static void perf_swevent_start_hrtimer(struct perf_event *event)
11053 struct hw_perf_event *hwc = &event->hw;
11056 if (!is_sampling_event(event))
11059 period = local64_read(&hwc->period_left);
11064 local64_set(&hwc->period_left, 0);
11066 period = max_t(u64, 10000, hwc->sample_period);
11068 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
11069 HRTIMER_MODE_REL_PINNED_HARD);
11072 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
11074 struct hw_perf_event *hwc = &event->hw;
11076 if (is_sampling_event(event)) {
11077 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
11078 local64_set(&hwc->period_left, ktime_to_ns(remaining));
11080 hrtimer_cancel(&hwc->hrtimer);
11084 static void perf_swevent_init_hrtimer(struct perf_event *event)
11086 struct hw_perf_event *hwc = &event->hw;
11088 if (!is_sampling_event(event))
11091 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
11092 hwc->hrtimer.function = perf_swevent_hrtimer;
11095 * Since hrtimers have a fixed rate, we can do a static freq->period
11096 * mapping and avoid the whole period adjust feedback stuff.
11098 if (event->attr.freq) {
11099 long freq = event->attr.sample_freq;
11101 event->attr.sample_period = NSEC_PER_SEC / freq;
11102 hwc->sample_period = event->attr.sample_period;
11103 local64_set(&hwc->period_left, hwc->sample_period);
11104 hwc->last_period = hwc->sample_period;
11105 event->attr.freq = 0;
11110 * Software event: cpu wall time clock
11113 static void cpu_clock_event_update(struct perf_event *event)
11118 now = local_clock();
11119 prev = local64_xchg(&event->hw.prev_count, now);
11120 local64_add(now - prev, &event->count);
11123 static void cpu_clock_event_start(struct perf_event *event, int flags)
11125 local64_set(&event->hw.prev_count, local_clock());
11126 perf_swevent_start_hrtimer(event);
11129 static void cpu_clock_event_stop(struct perf_event *event, int flags)
11131 perf_swevent_cancel_hrtimer(event);
11132 cpu_clock_event_update(event);
11135 static int cpu_clock_event_add(struct perf_event *event, int flags)
11137 if (flags & PERF_EF_START)
11138 cpu_clock_event_start(event, flags);
11139 perf_event_update_userpage(event);
11144 static void cpu_clock_event_del(struct perf_event *event, int flags)
11146 cpu_clock_event_stop(event, flags);
11149 static void cpu_clock_event_read(struct perf_event *event)
11151 cpu_clock_event_update(event);
11154 static int cpu_clock_event_init(struct perf_event *event)
11156 if (event->attr.type != perf_cpu_clock.type)
11159 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
11163 * no branch sampling for software events
11165 if (has_branch_stack(event))
11166 return -EOPNOTSUPP;
11168 perf_swevent_init_hrtimer(event);
11173 static struct pmu perf_cpu_clock = {
11174 .task_ctx_nr = perf_sw_context,
11176 .capabilities = PERF_PMU_CAP_NO_NMI,
11177 .dev = PMU_NULL_DEV,
11179 .event_init = cpu_clock_event_init,
11180 .add = cpu_clock_event_add,
11181 .del = cpu_clock_event_del,
11182 .start = cpu_clock_event_start,
11183 .stop = cpu_clock_event_stop,
11184 .read = cpu_clock_event_read,
11188 * Software event: task time clock
11191 static void task_clock_event_update(struct perf_event *event, u64 now)
11196 prev = local64_xchg(&event->hw.prev_count, now);
11197 delta = now - prev;
11198 local64_add(delta, &event->count);
11201 static void task_clock_event_start(struct perf_event *event, int flags)
11203 local64_set(&event->hw.prev_count, event->ctx->time);
11204 perf_swevent_start_hrtimer(event);
11207 static void task_clock_event_stop(struct perf_event *event, int flags)
11209 perf_swevent_cancel_hrtimer(event);
11210 task_clock_event_update(event, event->ctx->time);
11213 static int task_clock_event_add(struct perf_event *event, int flags)
11215 if (flags & PERF_EF_START)
11216 task_clock_event_start(event, flags);
11217 perf_event_update_userpage(event);
11222 static void task_clock_event_del(struct perf_event *event, int flags)
11224 task_clock_event_stop(event, PERF_EF_UPDATE);
11227 static void task_clock_event_read(struct perf_event *event)
11229 u64 now = perf_clock();
11230 u64 delta = now - event->ctx->timestamp;
11231 u64 time = event->ctx->time + delta;
11233 task_clock_event_update(event, time);
11236 static int task_clock_event_init(struct perf_event *event)
11238 if (event->attr.type != perf_task_clock.type)
11241 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
11245 * no branch sampling for software events
11247 if (has_branch_stack(event))
11248 return -EOPNOTSUPP;
11250 perf_swevent_init_hrtimer(event);
11255 static struct pmu perf_task_clock = {
11256 .task_ctx_nr = perf_sw_context,
11258 .capabilities = PERF_PMU_CAP_NO_NMI,
11259 .dev = PMU_NULL_DEV,
11261 .event_init = task_clock_event_init,
11262 .add = task_clock_event_add,
11263 .del = task_clock_event_del,
11264 .start = task_clock_event_start,
11265 .stop = task_clock_event_stop,
11266 .read = task_clock_event_read,
11269 static void perf_pmu_nop_void(struct pmu *pmu)
11273 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
11277 static int perf_pmu_nop_int(struct pmu *pmu)
11282 static int perf_event_nop_int(struct perf_event *event, u64 value)
11287 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
11289 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
11291 __this_cpu_write(nop_txn_flags, flags);
11293 if (flags & ~PERF_PMU_TXN_ADD)
11296 perf_pmu_disable(pmu);
11299 static int perf_pmu_commit_txn(struct pmu *pmu)
11301 unsigned int flags = __this_cpu_read(nop_txn_flags);
11303 __this_cpu_write(nop_txn_flags, 0);
11305 if (flags & ~PERF_PMU_TXN_ADD)
11308 perf_pmu_enable(pmu);
11312 static void perf_pmu_cancel_txn(struct pmu *pmu)
11314 unsigned int flags = __this_cpu_read(nop_txn_flags);
11316 __this_cpu_write(nop_txn_flags, 0);
11318 if (flags & ~PERF_PMU_TXN_ADD)
11321 perf_pmu_enable(pmu);
11324 static int perf_event_idx_default(struct perf_event *event)
11329 static void free_pmu_context(struct pmu *pmu)
11331 free_percpu(pmu->cpu_pmu_context);
11335 * Let userspace know that this PMU supports address range filtering:
11337 static ssize_t nr_addr_filters_show(struct device *dev,
11338 struct device_attribute *attr,
11341 struct pmu *pmu = dev_get_drvdata(dev);
11343 return scnprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters);
11345 DEVICE_ATTR_RO(nr_addr_filters);
11347 static struct idr pmu_idr;
11350 type_show(struct device *dev, struct device_attribute *attr, char *page)
11352 struct pmu *pmu = dev_get_drvdata(dev);
11354 return scnprintf(page, PAGE_SIZE - 1, "%d\n", pmu->type);
11356 static DEVICE_ATTR_RO(type);
11359 perf_event_mux_interval_ms_show(struct device *dev,
11360 struct device_attribute *attr,
11363 struct pmu *pmu = dev_get_drvdata(dev);
11365 return scnprintf(page, PAGE_SIZE - 1, "%d\n", pmu->hrtimer_interval_ms);
11368 static DEFINE_MUTEX(mux_interval_mutex);
11371 perf_event_mux_interval_ms_store(struct device *dev,
11372 struct device_attribute *attr,
11373 const char *buf, size_t count)
11375 struct pmu *pmu = dev_get_drvdata(dev);
11376 int timer, cpu, ret;
11378 ret = kstrtoint(buf, 0, &timer);
11385 /* same value, noting to do */
11386 if (timer == pmu->hrtimer_interval_ms)
11389 mutex_lock(&mux_interval_mutex);
11390 pmu->hrtimer_interval_ms = timer;
11392 /* update all cpuctx for this PMU */
11394 for_each_online_cpu(cpu) {
11395 struct perf_cpu_pmu_context *cpc;
11396 cpc = per_cpu_ptr(pmu->cpu_pmu_context, cpu);
11397 cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
11399 cpu_function_call(cpu, perf_mux_hrtimer_restart_ipi, cpc);
11401 cpus_read_unlock();
11402 mutex_unlock(&mux_interval_mutex);
11406 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
11408 static struct attribute *pmu_dev_attrs[] = {
11409 &dev_attr_type.attr,
11410 &dev_attr_perf_event_mux_interval_ms.attr,
11413 ATTRIBUTE_GROUPS(pmu_dev);
11415 static int pmu_bus_running;
11416 static struct bus_type pmu_bus = {
11417 .name = "event_source",
11418 .dev_groups = pmu_dev_groups,
11421 static void pmu_dev_release(struct device *dev)
11426 static int pmu_dev_alloc(struct pmu *pmu)
11430 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
11434 pmu->dev->groups = pmu->attr_groups;
11435 device_initialize(pmu->dev);
11437 dev_set_drvdata(pmu->dev, pmu);
11438 pmu->dev->bus = &pmu_bus;
11439 pmu->dev->parent = pmu->parent;
11440 pmu->dev->release = pmu_dev_release;
11442 ret = dev_set_name(pmu->dev, "%s", pmu->name);
11446 ret = device_add(pmu->dev);
11450 /* For PMUs with address filters, throw in an extra attribute: */
11451 if (pmu->nr_addr_filters)
11452 ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
11457 if (pmu->attr_update)
11458 ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);
11467 device_del(pmu->dev);
11470 put_device(pmu->dev);
11474 static struct lock_class_key cpuctx_mutex;
11475 static struct lock_class_key cpuctx_lock;
11477 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
11479 int cpu, ret, max = PERF_TYPE_MAX;
11481 mutex_lock(&pmus_lock);
11483 pmu->pmu_disable_count = alloc_percpu(int);
11484 if (!pmu->pmu_disable_count)
11488 if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) {
11498 ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL);
11502 WARN_ON(type >= 0 && ret != type);
11507 if (pmu_bus_running && !pmu->dev) {
11508 ret = pmu_dev_alloc(pmu);
11514 pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context);
11515 if (!pmu->cpu_pmu_context)
11518 for_each_possible_cpu(cpu) {
11519 struct perf_cpu_pmu_context *cpc;
11521 cpc = per_cpu_ptr(pmu->cpu_pmu_context, cpu);
11522 __perf_init_event_pmu_context(&cpc->epc, pmu);
11523 __perf_mux_hrtimer_init(cpc, cpu);
11526 if (!pmu->start_txn) {
11527 if (pmu->pmu_enable) {
11529 * If we have pmu_enable/pmu_disable calls, install
11530 * transaction stubs that use that to try and batch
11531 * hardware accesses.
11533 pmu->start_txn = perf_pmu_start_txn;
11534 pmu->commit_txn = perf_pmu_commit_txn;
11535 pmu->cancel_txn = perf_pmu_cancel_txn;
11537 pmu->start_txn = perf_pmu_nop_txn;
11538 pmu->commit_txn = perf_pmu_nop_int;
11539 pmu->cancel_txn = perf_pmu_nop_void;
11543 if (!pmu->pmu_enable) {
11544 pmu->pmu_enable = perf_pmu_nop_void;
11545 pmu->pmu_disable = perf_pmu_nop_void;
11548 if (!pmu->check_period)
11549 pmu->check_period = perf_event_nop_int;
11551 if (!pmu->event_idx)
11552 pmu->event_idx = perf_event_idx_default;
11554 list_add_rcu(&pmu->entry, &pmus);
11555 atomic_set(&pmu->exclusive_cnt, 0);
11558 mutex_unlock(&pmus_lock);
11563 if (pmu->dev && pmu->dev != PMU_NULL_DEV) {
11564 device_del(pmu->dev);
11565 put_device(pmu->dev);
11569 idr_remove(&pmu_idr, pmu->type);
11572 free_percpu(pmu->pmu_disable_count);
11575 EXPORT_SYMBOL_GPL(perf_pmu_register);
11577 void perf_pmu_unregister(struct pmu *pmu)
11579 mutex_lock(&pmus_lock);
11580 list_del_rcu(&pmu->entry);
11583 * We dereference the pmu list under both SRCU and regular RCU, so
11584 * synchronize against both of those.
11586 synchronize_srcu(&pmus_srcu);
11589 free_percpu(pmu->pmu_disable_count);
11590 idr_remove(&pmu_idr, pmu->type);
11591 if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) {
11592 if (pmu->nr_addr_filters)
11593 device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
11594 device_del(pmu->dev);
11595 put_device(pmu->dev);
11597 free_pmu_context(pmu);
11598 mutex_unlock(&pmus_lock);
11600 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
11602 static inline bool has_extended_regs(struct perf_event *event)
11604 return (event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK) ||
11605 (event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK);
11608 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
11610 struct perf_event_context *ctx = NULL;
11613 if (!try_module_get(pmu->module))
11617 * A number of pmu->event_init() methods iterate the sibling_list to,
11618 * for example, validate if the group fits on the PMU. Therefore,
11619 * if this is a sibling event, acquire the ctx->mutex to protect
11620 * the sibling_list.
11622 if (event->group_leader != event && pmu->task_ctx_nr != perf_sw_context) {
11624 * This ctx->mutex can nest when we're called through
11625 * inheritance. See the perf_event_ctx_lock_nested() comment.
11627 ctx = perf_event_ctx_lock_nested(event->group_leader,
11628 SINGLE_DEPTH_NESTING);
11633 ret = pmu->event_init(event);
11636 perf_event_ctx_unlock(event->group_leader, ctx);
11639 if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
11640 has_extended_regs(event))
11643 if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE &&
11644 event_has_any_exclude_flag(event))
11647 if (ret && event->destroy)
11648 event->destroy(event);
11652 module_put(pmu->module);
11657 static struct pmu *perf_init_event(struct perf_event *event)
11659 bool extended_type = false;
11660 int idx, type, ret;
11663 idx = srcu_read_lock(&pmus_srcu);
11666 * Save original type before calling pmu->event_init() since certain
11667 * pmus overwrites event->attr.type to forward event to another pmu.
11669 event->orig_type = event->attr.type;
11671 /* Try parent's PMU first: */
11672 if (event->parent && event->parent->pmu) {
11673 pmu = event->parent->pmu;
11674 ret = perf_try_init_event(pmu, event);
11680 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
11681 * are often aliases for PERF_TYPE_RAW.
11683 type = event->attr.type;
11684 if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE) {
11685 type = event->attr.config >> PERF_PMU_TYPE_SHIFT;
11687 type = PERF_TYPE_RAW;
11689 extended_type = true;
11690 event->attr.config &= PERF_HW_EVENT_MASK;
11696 pmu = idr_find(&pmu_idr, type);
11699 if (event->attr.type != type && type != PERF_TYPE_RAW &&
11700 !(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
11703 ret = perf_try_init_event(pmu, event);
11704 if (ret == -ENOENT && event->attr.type != type && !extended_type) {
11705 type = event->attr.type;
11710 pmu = ERR_PTR(ret);
11715 list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) {
11716 ret = perf_try_init_event(pmu, event);
11720 if (ret != -ENOENT) {
11721 pmu = ERR_PTR(ret);
11726 pmu = ERR_PTR(-ENOENT);
11728 srcu_read_unlock(&pmus_srcu, idx);
11733 static void attach_sb_event(struct perf_event *event)
11735 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
11737 raw_spin_lock(&pel->lock);
11738 list_add_rcu(&event->sb_list, &pel->list);
11739 raw_spin_unlock(&pel->lock);
11743 * We keep a list of all !task (and therefore per-cpu) events
11744 * that need to receive side-band records.
11746 * This avoids having to scan all the various PMU per-cpu contexts
11747 * looking for them.
11749 static void account_pmu_sb_event(struct perf_event *event)
11751 if (is_sb_event(event))
11752 attach_sb_event(event);
11755 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
11756 static void account_freq_event_nohz(void)
11758 #ifdef CONFIG_NO_HZ_FULL
11759 /* Lock so we don't race with concurrent unaccount */
11760 spin_lock(&nr_freq_lock);
11761 if (atomic_inc_return(&nr_freq_events) == 1)
11762 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
11763 spin_unlock(&nr_freq_lock);
11767 static void account_freq_event(void)
11769 if (tick_nohz_full_enabled())
11770 account_freq_event_nohz();
11772 atomic_inc(&nr_freq_events);
11776 static void account_event(struct perf_event *event)
11783 if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
11785 if (event->attr.mmap || event->attr.mmap_data)
11786 atomic_inc(&nr_mmap_events);
11787 if (event->attr.build_id)
11788 atomic_inc(&nr_build_id_events);
11789 if (event->attr.comm)
11790 atomic_inc(&nr_comm_events);
11791 if (event->attr.namespaces)
11792 atomic_inc(&nr_namespaces_events);
11793 if (event->attr.cgroup)
11794 atomic_inc(&nr_cgroup_events);
11795 if (event->attr.task)
11796 atomic_inc(&nr_task_events);
11797 if (event->attr.freq)
11798 account_freq_event();
11799 if (event->attr.context_switch) {
11800 atomic_inc(&nr_switch_events);
11803 if (has_branch_stack(event))
11805 if (is_cgroup_event(event))
11807 if (event->attr.ksymbol)
11808 atomic_inc(&nr_ksymbol_events);
11809 if (event->attr.bpf_event)
11810 atomic_inc(&nr_bpf_events);
11811 if (event->attr.text_poke)
11812 atomic_inc(&nr_text_poke_events);
11816 * We need the mutex here because static_branch_enable()
11817 * must complete *before* the perf_sched_count increment
11820 if (atomic_inc_not_zero(&perf_sched_count))
11823 mutex_lock(&perf_sched_mutex);
11824 if (!atomic_read(&perf_sched_count)) {
11825 static_branch_enable(&perf_sched_events);
11827 * Guarantee that all CPUs observe they key change and
11828 * call the perf scheduling hooks before proceeding to
11829 * install events that need them.
11834 * Now that we have waited for the sync_sched(), allow further
11835 * increments to by-pass the mutex.
11837 atomic_inc(&perf_sched_count);
11838 mutex_unlock(&perf_sched_mutex);
11842 account_pmu_sb_event(event);
11846 * Allocate and initialize an event structure
11848 static struct perf_event *
11849 perf_event_alloc(struct perf_event_attr *attr, int cpu,
11850 struct task_struct *task,
11851 struct perf_event *group_leader,
11852 struct perf_event *parent_event,
11853 perf_overflow_handler_t overflow_handler,
11854 void *context, int cgroup_fd)
11857 struct perf_event *event;
11858 struct hw_perf_event *hwc;
11859 long err = -EINVAL;
11862 if ((unsigned)cpu >= nr_cpu_ids) {
11863 if (!task || cpu != -1)
11864 return ERR_PTR(-EINVAL);
11866 if (attr->sigtrap && !task) {
11867 /* Requires a task: avoid signalling random tasks. */
11868 return ERR_PTR(-EINVAL);
11871 node = (cpu >= 0) ? cpu_to_node(cpu) : -1;
11872 event = kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO,
11875 return ERR_PTR(-ENOMEM);
11878 * Single events are their own group leaders, with an
11879 * empty sibling list:
11882 group_leader = event;
11884 mutex_init(&event->child_mutex);
11885 INIT_LIST_HEAD(&event->child_list);
11887 INIT_LIST_HEAD(&event->event_entry);
11888 INIT_LIST_HEAD(&event->sibling_list);
11889 INIT_LIST_HEAD(&event->active_list);
11890 init_event_group(event);
11891 INIT_LIST_HEAD(&event->rb_entry);
11892 INIT_LIST_HEAD(&event->active_entry);
11893 INIT_LIST_HEAD(&event->addr_filters.list);
11894 INIT_HLIST_NODE(&event->hlist_entry);
11897 init_waitqueue_head(&event->waitq);
11898 init_irq_work(&event->pending_irq, perf_pending_irq);
11899 init_task_work(&event->pending_task, perf_pending_task);
11901 mutex_init(&event->mmap_mutex);
11902 raw_spin_lock_init(&event->addr_filters.lock);
11904 atomic_long_set(&event->refcount, 1);
11906 event->attr = *attr;
11907 event->group_leader = group_leader;
11911 event->parent = parent_event;
11913 event->ns = get_pid_ns(task_active_pid_ns(current));
11914 event->id = atomic64_inc_return(&perf_event_id);
11916 event->state = PERF_EVENT_STATE_INACTIVE;
11919 event->event_caps = parent_event->event_caps;
11922 event->attach_state = PERF_ATTACH_TASK;
11924 * XXX pmu::event_init needs to know what task to account to
11925 * and we cannot use the ctx information because we need the
11926 * pmu before we get a ctx.
11928 event->hw.target = get_task_struct(task);
11931 event->clock = &local_clock;
11933 event->clock = parent_event->clock;
11935 if (!overflow_handler && parent_event) {
11936 overflow_handler = parent_event->overflow_handler;
11937 context = parent_event->overflow_handler_context;
11938 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
11939 if (overflow_handler == bpf_overflow_handler) {
11940 struct bpf_prog *prog = parent_event->prog;
11942 bpf_prog_inc(prog);
11943 event->prog = prog;
11944 event->orig_overflow_handler =
11945 parent_event->orig_overflow_handler;
11950 if (overflow_handler) {
11951 event->overflow_handler = overflow_handler;
11952 event->overflow_handler_context = context;
11953 } else if (is_write_backward(event)){
11954 event->overflow_handler = perf_event_output_backward;
11955 event->overflow_handler_context = NULL;
11957 event->overflow_handler = perf_event_output_forward;
11958 event->overflow_handler_context = NULL;
11961 perf_event__state_init(event);
11966 hwc->sample_period = attr->sample_period;
11967 if (attr->freq && attr->sample_freq)
11968 hwc->sample_period = 1;
11969 hwc->last_period = hwc->sample_period;
11971 local64_set(&hwc->period_left, hwc->sample_period);
11974 * We currently do not support PERF_SAMPLE_READ on inherited events.
11975 * See perf_output_read().
11977 if (attr->inherit && (attr->sample_type & PERF_SAMPLE_READ))
11980 if (!has_branch_stack(event))
11981 event->attr.branch_sample_type = 0;
11983 pmu = perf_init_event(event);
11985 err = PTR_ERR(pmu);
11990 * Disallow uncore-task events. Similarly, disallow uncore-cgroup
11991 * events (they don't make sense as the cgroup will be different
11992 * on other CPUs in the uncore mask).
11994 if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1)) {
11999 if (event->attr.aux_output &&
12000 !(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT)) {
12005 if (cgroup_fd != -1) {
12006 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
12011 err = exclusive_event_init(event);
12015 if (has_addr_filter(event)) {
12016 event->addr_filter_ranges = kcalloc(pmu->nr_addr_filters,
12017 sizeof(struct perf_addr_filter_range),
12019 if (!event->addr_filter_ranges) {
12025 * Clone the parent's vma offsets: they are valid until exec()
12026 * even if the mm is not shared with the parent.
12028 if (event->parent) {
12029 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
12031 raw_spin_lock_irq(&ifh->lock);
12032 memcpy(event->addr_filter_ranges,
12033 event->parent->addr_filter_ranges,
12034 pmu->nr_addr_filters * sizeof(struct perf_addr_filter_range));
12035 raw_spin_unlock_irq(&ifh->lock);
12038 /* force hw sync on the address filters */
12039 event->addr_filters_gen = 1;
12042 if (!event->parent) {
12043 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
12044 err = get_callchain_buffers(attr->sample_max_stack);
12046 goto err_addr_filters;
12050 err = security_perf_event_alloc(event);
12052 goto err_callchain_buffer;
12054 /* symmetric to unaccount_event() in _free_event() */
12055 account_event(event);
12059 err_callchain_buffer:
12060 if (!event->parent) {
12061 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
12062 put_callchain_buffers();
12065 kfree(event->addr_filter_ranges);
12068 exclusive_event_destroy(event);
12071 if (is_cgroup_event(event))
12072 perf_detach_cgroup(event);
12073 if (event->destroy)
12074 event->destroy(event);
12075 module_put(pmu->module);
12077 if (event->hw.target)
12078 put_task_struct(event->hw.target);
12079 call_rcu(&event->rcu_head, free_event_rcu);
12081 return ERR_PTR(err);
12084 static int perf_copy_attr(struct perf_event_attr __user *uattr,
12085 struct perf_event_attr *attr)
12090 /* Zero the full structure, so that a short copy will be nice. */
12091 memset(attr, 0, sizeof(*attr));
12093 ret = get_user(size, &uattr->size);
12097 /* ABI compatibility quirk: */
12099 size = PERF_ATTR_SIZE_VER0;
12100 if (size < PERF_ATTR_SIZE_VER0 || size > PAGE_SIZE)
12103 ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size);
12112 if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
12115 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
12118 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
12121 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
12122 u64 mask = attr->branch_sample_type;
12124 /* only using defined bits */
12125 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
12128 /* at least one branch bit must be set */
12129 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
12132 /* propagate priv level, when not set for branch */
12133 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
12135 /* exclude_kernel checked on syscall entry */
12136 if (!attr->exclude_kernel)
12137 mask |= PERF_SAMPLE_BRANCH_KERNEL;
12139 if (!attr->exclude_user)
12140 mask |= PERF_SAMPLE_BRANCH_USER;
12142 if (!attr->exclude_hv)
12143 mask |= PERF_SAMPLE_BRANCH_HV;
12145 * adjust user setting (for HW filter setup)
12147 attr->branch_sample_type = mask;
12149 /* privileged levels capture (kernel, hv): check permissions */
12150 if (mask & PERF_SAMPLE_BRANCH_PERM_PLM) {
12151 ret = perf_allow_kernel(attr);
12157 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
12158 ret = perf_reg_validate(attr->sample_regs_user);
12163 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
12164 if (!arch_perf_have_user_stack_dump())
12168 * We have __u32 type for the size, but so far
12169 * we can only use __u16 as maximum due to the
12170 * __u16 sample size limit.
12172 if (attr->sample_stack_user >= USHRT_MAX)
12174 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
12178 if (!attr->sample_max_stack)
12179 attr->sample_max_stack = sysctl_perf_event_max_stack;
12181 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
12182 ret = perf_reg_validate(attr->sample_regs_intr);
12184 #ifndef CONFIG_CGROUP_PERF
12185 if (attr->sample_type & PERF_SAMPLE_CGROUP)
12188 if ((attr->sample_type & PERF_SAMPLE_WEIGHT) &&
12189 (attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT))
12192 if (!attr->inherit && attr->inherit_thread)
12195 if (attr->remove_on_exec && attr->enable_on_exec)
12198 if (attr->sigtrap && !attr->remove_on_exec)
12205 put_user(sizeof(*attr), &uattr->size);
12210 static void mutex_lock_double(struct mutex *a, struct mutex *b)
12216 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
12220 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
12222 struct perf_buffer *rb = NULL;
12225 if (!output_event) {
12226 mutex_lock(&event->mmap_mutex);
12230 /* don't allow circular references */
12231 if (event == output_event)
12235 * Don't allow cross-cpu buffers
12237 if (output_event->cpu != event->cpu)
12241 * If its not a per-cpu rb, it must be the same task.
12243 if (output_event->cpu == -1 && output_event->hw.target != event->hw.target)
12247 * Mixing clocks in the same buffer is trouble you don't need.
12249 if (output_event->clock != event->clock)
12253 * Either writing ring buffer from beginning or from end.
12254 * Mixing is not allowed.
12256 if (is_write_backward(output_event) != is_write_backward(event))
12260 * If both events generate aux data, they must be on the same PMU
12262 if (has_aux(event) && has_aux(output_event) &&
12263 event->pmu != output_event->pmu)
12267 * Hold both mmap_mutex to serialize against perf_mmap_close(). Since
12268 * output_event is already on rb->event_list, and the list iteration
12269 * restarts after every removal, it is guaranteed this new event is
12270 * observed *OR* if output_event is already removed, it's guaranteed we
12271 * observe !rb->mmap_count.
12273 mutex_lock_double(&event->mmap_mutex, &output_event->mmap_mutex);
12275 /* Can't redirect output if we've got an active mmap() */
12276 if (atomic_read(&event->mmap_count))
12279 if (output_event) {
12280 /* get the rb we want to redirect to */
12281 rb = ring_buffer_get(output_event);
12285 /* did we race against perf_mmap_close() */
12286 if (!atomic_read(&rb->mmap_count)) {
12287 ring_buffer_put(rb);
12292 ring_buffer_attach(event, rb);
12296 mutex_unlock(&event->mmap_mutex);
12298 mutex_unlock(&output_event->mmap_mutex);
12304 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
12306 bool nmi_safe = false;
12309 case CLOCK_MONOTONIC:
12310 event->clock = &ktime_get_mono_fast_ns;
12314 case CLOCK_MONOTONIC_RAW:
12315 event->clock = &ktime_get_raw_fast_ns;
12319 case CLOCK_REALTIME:
12320 event->clock = &ktime_get_real_ns;
12323 case CLOCK_BOOTTIME:
12324 event->clock = &ktime_get_boottime_ns;
12328 event->clock = &ktime_get_clocktai_ns;
12335 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
12342 perf_check_permission(struct perf_event_attr *attr, struct task_struct *task)
12344 unsigned int ptrace_mode = PTRACE_MODE_READ_REALCREDS;
12345 bool is_capable = perfmon_capable();
12347 if (attr->sigtrap) {
12349 * perf_event_attr::sigtrap sends signals to the other task.
12350 * Require the current task to also have CAP_KILL.
12353 is_capable &= ns_capable(__task_cred(task)->user_ns, CAP_KILL);
12357 * If the required capabilities aren't available, checks for
12358 * ptrace permissions: upgrade to ATTACH, since sending signals
12359 * can effectively change the target task.
12361 ptrace_mode = PTRACE_MODE_ATTACH_REALCREDS;
12365 * Preserve ptrace permission check for backwards compatibility. The
12366 * ptrace check also includes checks that the current task and other
12367 * task have matching uids, and is therefore not done here explicitly.
12369 return is_capable || ptrace_may_access(task, ptrace_mode);
12373 * sys_perf_event_open - open a performance event, associate it to a task/cpu
12375 * @attr_uptr: event_id type attributes for monitoring/sampling
12378 * @group_fd: group leader event fd
12379 * @flags: perf event open flags
12381 SYSCALL_DEFINE5(perf_event_open,
12382 struct perf_event_attr __user *, attr_uptr,
12383 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
12385 struct perf_event *group_leader = NULL, *output_event = NULL;
12386 struct perf_event_pmu_context *pmu_ctx;
12387 struct perf_event *event, *sibling;
12388 struct perf_event_attr attr;
12389 struct perf_event_context *ctx;
12390 struct file *event_file = NULL;
12391 struct fd group = {NULL, 0};
12392 struct task_struct *task = NULL;
12395 int move_group = 0;
12397 int f_flags = O_RDWR;
12398 int cgroup_fd = -1;
12400 /* for future expandability... */
12401 if (flags & ~PERF_FLAG_ALL)
12404 err = perf_copy_attr(attr_uptr, &attr);
12408 /* Do we allow access to perf_event_open(2) ? */
12409 err = security_perf_event_open(&attr, PERF_SECURITY_OPEN);
12413 if (!attr.exclude_kernel) {
12414 err = perf_allow_kernel(&attr);
12419 if (attr.namespaces) {
12420 if (!perfmon_capable())
12425 if (attr.sample_freq > sysctl_perf_event_sample_rate)
12428 if (attr.sample_period & (1ULL << 63))
12432 /* Only privileged users can get physical addresses */
12433 if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR)) {
12434 err = perf_allow_kernel(&attr);
12439 /* REGS_INTR can leak data, lockdown must prevent this */
12440 if (attr.sample_type & PERF_SAMPLE_REGS_INTR) {
12441 err = security_locked_down(LOCKDOWN_PERF);
12447 * In cgroup mode, the pid argument is used to pass the fd
12448 * opened to the cgroup directory in cgroupfs. The cpu argument
12449 * designates the cpu on which to monitor threads from that
12452 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
12455 if (flags & PERF_FLAG_FD_CLOEXEC)
12456 f_flags |= O_CLOEXEC;
12458 event_fd = get_unused_fd_flags(f_flags);
12462 if (group_fd != -1) {
12463 err = perf_fget_light(group_fd, &group);
12466 group_leader = group.file->private_data;
12467 if (flags & PERF_FLAG_FD_OUTPUT)
12468 output_event = group_leader;
12469 if (flags & PERF_FLAG_FD_NO_GROUP)
12470 group_leader = NULL;
12473 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
12474 task = find_lively_task_by_vpid(pid);
12475 if (IS_ERR(task)) {
12476 err = PTR_ERR(task);
12481 if (task && group_leader &&
12482 group_leader->attr.inherit != attr.inherit) {
12487 if (flags & PERF_FLAG_PID_CGROUP)
12490 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
12491 NULL, NULL, cgroup_fd);
12492 if (IS_ERR(event)) {
12493 err = PTR_ERR(event);
12497 if (is_sampling_event(event)) {
12498 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
12505 * Special case software events and allow them to be part of
12506 * any hardware group.
12510 if (attr.use_clockid) {
12511 err = perf_event_set_clock(event, attr.clockid);
12516 if (pmu->task_ctx_nr == perf_sw_context)
12517 event->event_caps |= PERF_EV_CAP_SOFTWARE;
12520 err = down_read_interruptible(&task->signal->exec_update_lock);
12525 * We must hold exec_update_lock across this and any potential
12526 * perf_install_in_context() call for this new event to
12527 * serialize against exec() altering our credentials (and the
12528 * perf_event_exit_task() that could imply).
12531 if (!perf_check_permission(&attr, task))
12536 * Get the target context (task or percpu):
12538 ctx = find_get_context(task, event);
12540 err = PTR_ERR(ctx);
12544 mutex_lock(&ctx->mutex);
12546 if (ctx->task == TASK_TOMBSTONE) {
12553 * Check if the @cpu we're creating an event for is online.
12555 * We use the perf_cpu_context::ctx::mutex to serialize against
12556 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
12558 struct perf_cpu_context *cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu);
12560 if (!cpuctx->online) {
12566 if (group_leader) {
12570 * Do not allow a recursive hierarchy (this new sibling
12571 * becoming part of another group-sibling):
12573 if (group_leader->group_leader != group_leader)
12576 /* All events in a group should have the same clock */
12577 if (group_leader->clock != event->clock)
12581 * Make sure we're both events for the same CPU;
12582 * grouping events for different CPUs is broken; since
12583 * you can never concurrently schedule them anyhow.
12585 if (group_leader->cpu != event->cpu)
12589 * Make sure we're both on the same context; either task or cpu.
12591 if (group_leader->ctx != ctx)
12595 * Only a group leader can be exclusive or pinned
12597 if (attr.exclusive || attr.pinned)
12600 if (is_software_event(event) &&
12601 !in_software_context(group_leader)) {
12603 * If the event is a sw event, but the group_leader
12604 * is on hw context.
12606 * Allow the addition of software events to hw
12607 * groups, this is safe because software events
12608 * never fail to schedule.
12610 * Note the comment that goes with struct
12611 * perf_event_pmu_context.
12613 pmu = group_leader->pmu_ctx->pmu;
12614 } else if (!is_software_event(event)) {
12615 if (is_software_event(group_leader) &&
12616 (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
12618 * In case the group is a pure software group, and we
12619 * try to add a hardware event, move the whole group to
12620 * the hardware context.
12625 /* Don't allow group of multiple hw events from different pmus */
12626 if (!in_software_context(group_leader) &&
12627 group_leader->pmu_ctx->pmu != pmu)
12633 * Now that we're certain of the pmu; find the pmu_ctx.
12635 pmu_ctx = find_get_pmu_context(pmu, ctx, event);
12636 if (IS_ERR(pmu_ctx)) {
12637 err = PTR_ERR(pmu_ctx);
12640 event->pmu_ctx = pmu_ctx;
12642 if (output_event) {
12643 err = perf_event_set_output(event, output_event);
12648 if (!perf_event_validate_size(event)) {
12653 if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader)) {
12659 * Must be under the same ctx::mutex as perf_install_in_context(),
12660 * because we need to serialize with concurrent event creation.
12662 if (!exclusive_event_installable(event, ctx)) {
12667 WARN_ON_ONCE(ctx->parent_ctx);
12669 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, f_flags);
12670 if (IS_ERR(event_file)) {
12671 err = PTR_ERR(event_file);
12677 * This is the point on no return; we cannot fail hereafter. This is
12678 * where we start modifying current state.
12682 perf_remove_from_context(group_leader, 0);
12683 put_pmu_ctx(group_leader->pmu_ctx);
12685 for_each_sibling_event(sibling, group_leader) {
12686 perf_remove_from_context(sibling, 0);
12687 put_pmu_ctx(sibling->pmu_ctx);
12691 * Install the group siblings before the group leader.
12693 * Because a group leader will try and install the entire group
12694 * (through the sibling list, which is still in-tact), we can
12695 * end up with siblings installed in the wrong context.
12697 * By installing siblings first we NO-OP because they're not
12698 * reachable through the group lists.
12700 for_each_sibling_event(sibling, group_leader) {
12701 sibling->pmu_ctx = pmu_ctx;
12702 get_pmu_ctx(pmu_ctx);
12703 perf_event__state_init(sibling);
12704 perf_install_in_context(ctx, sibling, sibling->cpu);
12708 * Removing from the context ends up with disabled
12709 * event. What we want here is event in the initial
12710 * startup state, ready to be add into new context.
12712 group_leader->pmu_ctx = pmu_ctx;
12713 get_pmu_ctx(pmu_ctx);
12714 perf_event__state_init(group_leader);
12715 perf_install_in_context(ctx, group_leader, group_leader->cpu);
12719 * Precalculate sample_data sizes; do while holding ctx::mutex such
12720 * that we're serialized against further additions and before
12721 * perf_install_in_context() which is the point the event is active and
12722 * can use these values.
12724 perf_event__header_size(event);
12725 perf_event__id_header_size(event);
12727 event->owner = current;
12729 perf_install_in_context(ctx, event, event->cpu);
12730 perf_unpin_context(ctx);
12732 mutex_unlock(&ctx->mutex);
12735 up_read(&task->signal->exec_update_lock);
12736 put_task_struct(task);
12739 mutex_lock(¤t->perf_event_mutex);
12740 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
12741 mutex_unlock(¤t->perf_event_mutex);
12744 * Drop the reference on the group_event after placing the
12745 * new event on the sibling_list. This ensures destruction
12746 * of the group leader will find the pointer to itself in
12747 * perf_group_detach().
12750 fd_install(event_fd, event_file);
12754 put_pmu_ctx(event->pmu_ctx);
12755 event->pmu_ctx = NULL; /* _free_event() */
12757 mutex_unlock(&ctx->mutex);
12758 perf_unpin_context(ctx);
12762 up_read(&task->signal->exec_update_lock);
12767 put_task_struct(task);
12771 put_unused_fd(event_fd);
12776 * perf_event_create_kernel_counter
12778 * @attr: attributes of the counter to create
12779 * @cpu: cpu in which the counter is bound
12780 * @task: task to profile (NULL for percpu)
12781 * @overflow_handler: callback to trigger when we hit the event
12782 * @context: context data could be used in overflow_handler callback
12784 struct perf_event *
12785 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
12786 struct task_struct *task,
12787 perf_overflow_handler_t overflow_handler,
12790 struct perf_event_pmu_context *pmu_ctx;
12791 struct perf_event_context *ctx;
12792 struct perf_event *event;
12797 * Grouping is not supported for kernel events, neither is 'AUX',
12798 * make sure the caller's intentions are adjusted.
12800 if (attr->aux_output)
12801 return ERR_PTR(-EINVAL);
12803 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
12804 overflow_handler, context, -1);
12805 if (IS_ERR(event)) {
12806 err = PTR_ERR(event);
12810 /* Mark owner so we could distinguish it from user events. */
12811 event->owner = TASK_TOMBSTONE;
12814 if (pmu->task_ctx_nr == perf_sw_context)
12815 event->event_caps |= PERF_EV_CAP_SOFTWARE;
12818 * Get the target context (task or percpu):
12820 ctx = find_get_context(task, event);
12822 err = PTR_ERR(ctx);
12826 WARN_ON_ONCE(ctx->parent_ctx);
12827 mutex_lock(&ctx->mutex);
12828 if (ctx->task == TASK_TOMBSTONE) {
12833 pmu_ctx = find_get_pmu_context(pmu, ctx, event);
12834 if (IS_ERR(pmu_ctx)) {
12835 err = PTR_ERR(pmu_ctx);
12838 event->pmu_ctx = pmu_ctx;
12842 * Check if the @cpu we're creating an event for is online.
12844 * We use the perf_cpu_context::ctx::mutex to serialize against
12845 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
12847 struct perf_cpu_context *cpuctx =
12848 container_of(ctx, struct perf_cpu_context, ctx);
12849 if (!cpuctx->online) {
12855 if (!exclusive_event_installable(event, ctx)) {
12860 perf_install_in_context(ctx, event, event->cpu);
12861 perf_unpin_context(ctx);
12862 mutex_unlock(&ctx->mutex);
12867 put_pmu_ctx(pmu_ctx);
12868 event->pmu_ctx = NULL; /* _free_event() */
12870 mutex_unlock(&ctx->mutex);
12871 perf_unpin_context(ctx);
12876 return ERR_PTR(err);
12878 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
12880 static void __perf_pmu_remove(struct perf_event_context *ctx,
12881 int cpu, struct pmu *pmu,
12882 struct perf_event_groups *groups,
12883 struct list_head *events)
12885 struct perf_event *event, *sibling;
12887 perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu) {
12888 perf_remove_from_context(event, 0);
12889 put_pmu_ctx(event->pmu_ctx);
12890 list_add(&event->migrate_entry, events);
12892 for_each_sibling_event(sibling, event) {
12893 perf_remove_from_context(sibling, 0);
12894 put_pmu_ctx(sibling->pmu_ctx);
12895 list_add(&sibling->migrate_entry, events);
12900 static void __perf_pmu_install_event(struct pmu *pmu,
12901 struct perf_event_context *ctx,
12902 int cpu, struct perf_event *event)
12904 struct perf_event_pmu_context *epc;
12905 struct perf_event_context *old_ctx = event->ctx;
12907 get_ctx(ctx); /* normally find_get_context() */
12910 epc = find_get_pmu_context(pmu, ctx, event);
12911 event->pmu_ctx = epc;
12913 if (event->state >= PERF_EVENT_STATE_OFF)
12914 event->state = PERF_EVENT_STATE_INACTIVE;
12915 perf_install_in_context(ctx, event, cpu);
12918 * Now that event->ctx is updated and visible, put the old ctx.
12923 static void __perf_pmu_install(struct perf_event_context *ctx,
12924 int cpu, struct pmu *pmu, struct list_head *events)
12926 struct perf_event *event, *tmp;
12929 * Re-instate events in 2 passes.
12931 * Skip over group leaders and only install siblings on this first
12932 * pass, siblings will not get enabled without a leader, however a
12933 * leader will enable its siblings, even if those are still on the old
12936 list_for_each_entry_safe(event, tmp, events, migrate_entry) {
12937 if (event->group_leader == event)
12940 list_del(&event->migrate_entry);
12941 __perf_pmu_install_event(pmu, ctx, cpu, event);
12945 * Once all the siblings are setup properly, install the group leaders
12948 list_for_each_entry_safe(event, tmp, events, migrate_entry) {
12949 list_del(&event->migrate_entry);
12950 __perf_pmu_install_event(pmu, ctx, cpu, event);
12954 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
12956 struct perf_event_context *src_ctx, *dst_ctx;
12960 * Since per-cpu context is persistent, no need to grab an extra
12963 src_ctx = &per_cpu_ptr(&perf_cpu_context, src_cpu)->ctx;
12964 dst_ctx = &per_cpu_ptr(&perf_cpu_context, dst_cpu)->ctx;
12967 * See perf_event_ctx_lock() for comments on the details
12968 * of swizzling perf_event::ctx.
12970 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
12972 __perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->pinned_groups, &events);
12973 __perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->flexible_groups, &events);
12975 if (!list_empty(&events)) {
12977 * Wait for the events to quiesce before re-instating them.
12981 __perf_pmu_install(dst_ctx, dst_cpu, pmu, &events);
12984 mutex_unlock(&dst_ctx->mutex);
12985 mutex_unlock(&src_ctx->mutex);
12987 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
12989 static void sync_child_event(struct perf_event *child_event)
12991 struct perf_event *parent_event = child_event->parent;
12994 if (child_event->attr.inherit_stat) {
12995 struct task_struct *task = child_event->ctx->task;
12997 if (task && task != TASK_TOMBSTONE)
12998 perf_event_read_event(child_event, task);
13001 child_val = perf_event_count(child_event);
13004 * Add back the child's count to the parent's count:
13006 atomic64_add(child_val, &parent_event->child_count);
13007 atomic64_add(child_event->total_time_enabled,
13008 &parent_event->child_total_time_enabled);
13009 atomic64_add(child_event->total_time_running,
13010 &parent_event->child_total_time_running);
13014 perf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx)
13016 struct perf_event *parent_event = event->parent;
13017 unsigned long detach_flags = 0;
13019 if (parent_event) {
13021 * Do not destroy the 'original' grouping; because of the
13022 * context switch optimization the original events could've
13023 * ended up in a random child task.
13025 * If we were to destroy the original group, all group related
13026 * operations would cease to function properly after this
13027 * random child dies.
13029 * Do destroy all inherited groups, we don't care about those
13030 * and being thorough is better.
13032 detach_flags = DETACH_GROUP | DETACH_CHILD;
13033 mutex_lock(&parent_event->child_mutex);
13036 perf_remove_from_context(event, detach_flags);
13038 raw_spin_lock_irq(&ctx->lock);
13039 if (event->state > PERF_EVENT_STATE_EXIT)
13040 perf_event_set_state(event, PERF_EVENT_STATE_EXIT);
13041 raw_spin_unlock_irq(&ctx->lock);
13044 * Child events can be freed.
13046 if (parent_event) {
13047 mutex_unlock(&parent_event->child_mutex);
13049 * Kick perf_poll() for is_event_hup();
13051 perf_event_wakeup(parent_event);
13053 put_event(parent_event);
13058 * Parent events are governed by their filedesc, retain them.
13060 perf_event_wakeup(event);
13063 static void perf_event_exit_task_context(struct task_struct *child)
13065 struct perf_event_context *child_ctx, *clone_ctx = NULL;
13066 struct perf_event *child_event, *next;
13068 WARN_ON_ONCE(child != current);
13070 child_ctx = perf_pin_task_context(child);
13075 * In order to reduce the amount of tricky in ctx tear-down, we hold
13076 * ctx::mutex over the entire thing. This serializes against almost
13077 * everything that wants to access the ctx.
13079 * The exception is sys_perf_event_open() /
13080 * perf_event_create_kernel_count() which does find_get_context()
13081 * without ctx::mutex (it cannot because of the move_group double mutex
13082 * lock thing). See the comments in perf_install_in_context().
13084 mutex_lock(&child_ctx->mutex);
13087 * In a single ctx::lock section, de-schedule the events and detach the
13088 * context from the task such that we cannot ever get it scheduled back
13091 raw_spin_lock_irq(&child_ctx->lock);
13092 task_ctx_sched_out(child_ctx, EVENT_ALL);
13095 * Now that the context is inactive, destroy the task <-> ctx relation
13096 * and mark the context dead.
13098 RCU_INIT_POINTER(child->perf_event_ctxp, NULL);
13099 put_ctx(child_ctx); /* cannot be last */
13100 WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
13101 put_task_struct(current); /* cannot be last */
13103 clone_ctx = unclone_ctx(child_ctx);
13104 raw_spin_unlock_irq(&child_ctx->lock);
13107 put_ctx(clone_ctx);
13110 * Report the task dead after unscheduling the events so that we
13111 * won't get any samples after PERF_RECORD_EXIT. We can however still
13112 * get a few PERF_RECORD_READ events.
13114 perf_event_task(child, child_ctx, 0);
13116 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
13117 perf_event_exit_event(child_event, child_ctx);
13119 mutex_unlock(&child_ctx->mutex);
13121 put_ctx(child_ctx);
13125 * When a child task exits, feed back event values to parent events.
13127 * Can be called with exec_update_lock held when called from
13128 * setup_new_exec().
13130 void perf_event_exit_task(struct task_struct *child)
13132 struct perf_event *event, *tmp;
13134 mutex_lock(&child->perf_event_mutex);
13135 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
13137 list_del_init(&event->owner_entry);
13140 * Ensure the list deletion is visible before we clear
13141 * the owner, closes a race against perf_release() where
13142 * we need to serialize on the owner->perf_event_mutex.
13144 smp_store_release(&event->owner, NULL);
13146 mutex_unlock(&child->perf_event_mutex);
13148 perf_event_exit_task_context(child);
13151 * The perf_event_exit_task_context calls perf_event_task
13152 * with child's task_ctx, which generates EXIT events for
13153 * child contexts and sets child->perf_event_ctxp[] to NULL.
13154 * At this point we need to send EXIT events to cpu contexts.
13156 perf_event_task(child, NULL, 0);
13159 static void perf_free_event(struct perf_event *event,
13160 struct perf_event_context *ctx)
13162 struct perf_event *parent = event->parent;
13164 if (WARN_ON_ONCE(!parent))
13167 mutex_lock(&parent->child_mutex);
13168 list_del_init(&event->child_list);
13169 mutex_unlock(&parent->child_mutex);
13173 raw_spin_lock_irq(&ctx->lock);
13174 perf_group_detach(event);
13175 list_del_event(event, ctx);
13176 raw_spin_unlock_irq(&ctx->lock);
13181 * Free a context as created by inheritance by perf_event_init_task() below,
13182 * used by fork() in case of fail.
13184 * Even though the task has never lived, the context and events have been
13185 * exposed through the child_list, so we must take care tearing it all down.
13187 void perf_event_free_task(struct task_struct *task)
13189 struct perf_event_context *ctx;
13190 struct perf_event *event, *tmp;
13192 ctx = rcu_access_pointer(task->perf_event_ctxp);
13196 mutex_lock(&ctx->mutex);
13197 raw_spin_lock_irq(&ctx->lock);
13199 * Destroy the task <-> ctx relation and mark the context dead.
13201 * This is important because even though the task hasn't been
13202 * exposed yet the context has been (through child_list).
13204 RCU_INIT_POINTER(task->perf_event_ctxp, NULL);
13205 WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
13206 put_task_struct(task); /* cannot be last */
13207 raw_spin_unlock_irq(&ctx->lock);
13210 list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry)
13211 perf_free_event(event, ctx);
13213 mutex_unlock(&ctx->mutex);
13216 * perf_event_release_kernel() could've stolen some of our
13217 * child events and still have them on its free_list. In that
13218 * case we must wait for these events to have been freed (in
13219 * particular all their references to this task must've been
13222 * Without this copy_process() will unconditionally free this
13223 * task (irrespective of its reference count) and
13224 * _free_event()'s put_task_struct(event->hw.target) will be a
13227 * Wait for all events to drop their context reference.
13229 wait_var_event(&ctx->refcount, refcount_read(&ctx->refcount) == 1);
13230 put_ctx(ctx); /* must be last */
13233 void perf_event_delayed_put(struct task_struct *task)
13235 WARN_ON_ONCE(task->perf_event_ctxp);
13238 struct file *perf_event_get(unsigned int fd)
13240 struct file *file = fget(fd);
13242 return ERR_PTR(-EBADF);
13244 if (file->f_op != &perf_fops) {
13246 return ERR_PTR(-EBADF);
13252 const struct perf_event *perf_get_event(struct file *file)
13254 if (file->f_op != &perf_fops)
13255 return ERR_PTR(-EINVAL);
13257 return file->private_data;
13260 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
13263 return ERR_PTR(-EINVAL);
13265 return &event->attr;
13269 * Inherit an event from parent task to child task.
13272 * - valid pointer on success
13273 * - NULL for orphaned events
13274 * - IS_ERR() on error
13276 static struct perf_event *
13277 inherit_event(struct perf_event *parent_event,
13278 struct task_struct *parent,
13279 struct perf_event_context *parent_ctx,
13280 struct task_struct *child,
13281 struct perf_event *group_leader,
13282 struct perf_event_context *child_ctx)
13284 enum perf_event_state parent_state = parent_event->state;
13285 struct perf_event_pmu_context *pmu_ctx;
13286 struct perf_event *child_event;
13287 unsigned long flags;
13290 * Instead of creating recursive hierarchies of events,
13291 * we link inherited events back to the original parent,
13292 * which has a filp for sure, which we use as the reference
13295 if (parent_event->parent)
13296 parent_event = parent_event->parent;
13298 child_event = perf_event_alloc(&parent_event->attr,
13301 group_leader, parent_event,
13303 if (IS_ERR(child_event))
13304 return child_event;
13306 pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
13307 if (IS_ERR(pmu_ctx)) {
13308 free_event(child_event);
13309 return ERR_CAST(pmu_ctx);
13311 child_event->pmu_ctx = pmu_ctx;
13314 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
13315 * must be under the same lock in order to serialize against
13316 * perf_event_release_kernel(), such that either we must observe
13317 * is_orphaned_event() or they will observe us on the child_list.
13319 mutex_lock(&parent_event->child_mutex);
13320 if (is_orphaned_event(parent_event) ||
13321 !atomic_long_inc_not_zero(&parent_event->refcount)) {
13322 mutex_unlock(&parent_event->child_mutex);
13323 /* task_ctx_data is freed with child_ctx */
13324 free_event(child_event);
13328 get_ctx(child_ctx);
13331 * Make the child state follow the state of the parent event,
13332 * not its attr.disabled bit. We hold the parent's mutex,
13333 * so we won't race with perf_event_{en, dis}able_family.
13335 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
13336 child_event->state = PERF_EVENT_STATE_INACTIVE;
13338 child_event->state = PERF_EVENT_STATE_OFF;
13340 if (parent_event->attr.freq) {
13341 u64 sample_period = parent_event->hw.sample_period;
13342 struct hw_perf_event *hwc = &child_event->hw;
13344 hwc->sample_period = sample_period;
13345 hwc->last_period = sample_period;
13347 local64_set(&hwc->period_left, sample_period);
13350 child_event->ctx = child_ctx;
13351 child_event->overflow_handler = parent_event->overflow_handler;
13352 child_event->overflow_handler_context
13353 = parent_event->overflow_handler_context;
13356 * Precalculate sample_data sizes
13358 perf_event__header_size(child_event);
13359 perf_event__id_header_size(child_event);
13362 * Link it up in the child's context:
13364 raw_spin_lock_irqsave(&child_ctx->lock, flags);
13365 add_event_to_ctx(child_event, child_ctx);
13366 child_event->attach_state |= PERF_ATTACH_CHILD;
13367 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
13370 * Link this into the parent event's child list
13372 list_add_tail(&child_event->child_list, &parent_event->child_list);
13373 mutex_unlock(&parent_event->child_mutex);
13375 return child_event;
13379 * Inherits an event group.
13381 * This will quietly suppress orphaned events; !inherit_event() is not an error.
13382 * This matches with perf_event_release_kernel() removing all child events.
13388 static int inherit_group(struct perf_event *parent_event,
13389 struct task_struct *parent,
13390 struct perf_event_context *parent_ctx,
13391 struct task_struct *child,
13392 struct perf_event_context *child_ctx)
13394 struct perf_event *leader;
13395 struct perf_event *sub;
13396 struct perf_event *child_ctr;
13398 leader = inherit_event(parent_event, parent, parent_ctx,
13399 child, NULL, child_ctx);
13400 if (IS_ERR(leader))
13401 return PTR_ERR(leader);
13403 * @leader can be NULL here because of is_orphaned_event(). In this
13404 * case inherit_event() will create individual events, similar to what
13405 * perf_group_detach() would do anyway.
13407 for_each_sibling_event(sub, parent_event) {
13408 child_ctr = inherit_event(sub, parent, parent_ctx,
13409 child, leader, child_ctx);
13410 if (IS_ERR(child_ctr))
13411 return PTR_ERR(child_ctr);
13413 if (sub->aux_event == parent_event && child_ctr &&
13414 !perf_get_aux_event(child_ctr, leader))
13418 leader->group_generation = parent_event->group_generation;
13423 * Creates the child task context and tries to inherit the event-group.
13425 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
13426 * inherited_all set when we 'fail' to inherit an orphaned event; this is
13427 * consistent with perf_event_release_kernel() removing all child events.
13434 inherit_task_group(struct perf_event *event, struct task_struct *parent,
13435 struct perf_event_context *parent_ctx,
13436 struct task_struct *child,
13437 u64 clone_flags, int *inherited_all)
13439 struct perf_event_context *child_ctx;
13442 if (!event->attr.inherit ||
13443 (event->attr.inherit_thread && !(clone_flags & CLONE_THREAD)) ||
13444 /* Do not inherit if sigtrap and signal handlers were cleared. */
13445 (event->attr.sigtrap && (clone_flags & CLONE_CLEAR_SIGHAND))) {
13446 *inherited_all = 0;
13450 child_ctx = child->perf_event_ctxp;
13453 * This is executed from the parent task context, so
13454 * inherit events that have been marked for cloning.
13455 * First allocate and initialize a context for the
13458 child_ctx = alloc_perf_context(child);
13462 child->perf_event_ctxp = child_ctx;
13465 ret = inherit_group(event, parent, parent_ctx, child, child_ctx);
13467 *inherited_all = 0;
13473 * Initialize the perf_event context in task_struct
13475 static int perf_event_init_context(struct task_struct *child, u64 clone_flags)
13477 struct perf_event_context *child_ctx, *parent_ctx;
13478 struct perf_event_context *cloned_ctx;
13479 struct perf_event *event;
13480 struct task_struct *parent = current;
13481 int inherited_all = 1;
13482 unsigned long flags;
13485 if (likely(!parent->perf_event_ctxp))
13489 * If the parent's context is a clone, pin it so it won't get
13490 * swapped under us.
13492 parent_ctx = perf_pin_task_context(parent);
13497 * No need to check if parent_ctx != NULL here; since we saw
13498 * it non-NULL earlier, the only reason for it to become NULL
13499 * is if we exit, and since we're currently in the middle of
13500 * a fork we can't be exiting at the same time.
13504 * Lock the parent list. No need to lock the child - not PID
13505 * hashed yet and not running, so nobody can access it.
13507 mutex_lock(&parent_ctx->mutex);
13510 * We dont have to disable NMIs - we are only looking at
13511 * the list, not manipulating it:
13513 perf_event_groups_for_each(event, &parent_ctx->pinned_groups) {
13514 ret = inherit_task_group(event, parent, parent_ctx,
13515 child, clone_flags, &inherited_all);
13521 * We can't hold ctx->lock when iterating the ->flexible_group list due
13522 * to allocations, but we need to prevent rotation because
13523 * rotate_ctx() will change the list from interrupt context.
13525 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
13526 parent_ctx->rotate_disable = 1;
13527 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
13529 perf_event_groups_for_each(event, &parent_ctx->flexible_groups) {
13530 ret = inherit_task_group(event, parent, parent_ctx,
13531 child, clone_flags, &inherited_all);
13536 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
13537 parent_ctx->rotate_disable = 0;
13539 child_ctx = child->perf_event_ctxp;
13541 if (child_ctx && inherited_all) {
13543 * Mark the child context as a clone of the parent
13544 * context, or of whatever the parent is a clone of.
13546 * Note that if the parent is a clone, the holding of
13547 * parent_ctx->lock avoids it from being uncloned.
13549 cloned_ctx = parent_ctx->parent_ctx;
13551 child_ctx->parent_ctx = cloned_ctx;
13552 child_ctx->parent_gen = parent_ctx->parent_gen;
13554 child_ctx->parent_ctx = parent_ctx;
13555 child_ctx->parent_gen = parent_ctx->generation;
13557 get_ctx(child_ctx->parent_ctx);
13560 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
13562 mutex_unlock(&parent_ctx->mutex);
13564 perf_unpin_context(parent_ctx);
13565 put_ctx(parent_ctx);
13571 * Initialize the perf_event context in task_struct
13573 int perf_event_init_task(struct task_struct *child, u64 clone_flags)
13577 child->perf_event_ctxp = NULL;
13578 mutex_init(&child->perf_event_mutex);
13579 INIT_LIST_HEAD(&child->perf_event_list);
13581 ret = perf_event_init_context(child, clone_flags);
13583 perf_event_free_task(child);
13590 static void __init perf_event_init_all_cpus(void)
13592 struct swevent_htable *swhash;
13593 struct perf_cpu_context *cpuctx;
13596 zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL);
13598 for_each_possible_cpu(cpu) {
13599 swhash = &per_cpu(swevent_htable, cpu);
13600 mutex_init(&swhash->hlist_mutex);
13602 INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
13603 raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
13605 INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
13607 cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
13608 __perf_event_init_context(&cpuctx->ctx);
13609 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
13610 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
13611 cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
13612 cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default);
13613 cpuctx->heap = cpuctx->heap_default;
13617 static void perf_swevent_init_cpu(unsigned int cpu)
13619 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
13621 mutex_lock(&swhash->hlist_mutex);
13622 if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
13623 struct swevent_hlist *hlist;
13625 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
13627 rcu_assign_pointer(swhash->swevent_hlist, hlist);
13629 mutex_unlock(&swhash->hlist_mutex);
13632 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
13633 static void __perf_event_exit_context(void *__info)
13635 struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
13636 struct perf_event_context *ctx = __info;
13637 struct perf_event *event;
13639 raw_spin_lock(&ctx->lock);
13640 ctx_sched_out(ctx, EVENT_TIME);
13641 list_for_each_entry(event, &ctx->event_list, event_entry)
13642 __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
13643 raw_spin_unlock(&ctx->lock);
13646 static void perf_event_exit_cpu_context(int cpu)
13648 struct perf_cpu_context *cpuctx;
13649 struct perf_event_context *ctx;
13651 // XXX simplify cpuctx->online
13652 mutex_lock(&pmus_lock);
13653 cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
13654 ctx = &cpuctx->ctx;
13656 mutex_lock(&ctx->mutex);
13657 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
13658 cpuctx->online = 0;
13659 mutex_unlock(&ctx->mutex);
13660 cpumask_clear_cpu(cpu, perf_online_mask);
13661 mutex_unlock(&pmus_lock);
13665 static void perf_event_exit_cpu_context(int cpu) { }
13669 int perf_event_init_cpu(unsigned int cpu)
13671 struct perf_cpu_context *cpuctx;
13672 struct perf_event_context *ctx;
13674 perf_swevent_init_cpu(cpu);
13676 mutex_lock(&pmus_lock);
13677 cpumask_set_cpu(cpu, perf_online_mask);
13678 cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
13679 ctx = &cpuctx->ctx;
13681 mutex_lock(&ctx->mutex);
13682 cpuctx->online = 1;
13683 mutex_unlock(&ctx->mutex);
13684 mutex_unlock(&pmus_lock);
13689 int perf_event_exit_cpu(unsigned int cpu)
13691 perf_event_exit_cpu_context(cpu);
13696 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
13700 for_each_online_cpu(cpu)
13701 perf_event_exit_cpu(cpu);
13707 * Run the perf reboot notifier at the very last possible moment so that
13708 * the generic watchdog code runs as long as possible.
13710 static struct notifier_block perf_reboot_notifier = {
13711 .notifier_call = perf_reboot,
13712 .priority = INT_MIN,
13715 void __init perf_event_init(void)
13719 idr_init(&pmu_idr);
13721 perf_event_init_all_cpus();
13722 init_srcu_struct(&pmus_srcu);
13723 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
13724 perf_pmu_register(&perf_cpu_clock, "cpu_clock", -1);
13725 perf_pmu_register(&perf_task_clock, "task_clock", -1);
13726 perf_tp_register();
13727 perf_event_init_cpu(smp_processor_id());
13728 register_reboot_notifier(&perf_reboot_notifier);
13730 ret = init_hw_breakpoint();
13731 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
13733 perf_event_cache = KMEM_CACHE(perf_event, SLAB_PANIC);
13736 * Build time assertion that we keep the data_head at the intended
13737 * location. IOW, validation we got the __reserved[] size right.
13739 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
13743 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
13746 struct perf_pmu_events_attr *pmu_attr =
13747 container_of(attr, struct perf_pmu_events_attr, attr);
13749 if (pmu_attr->event_str)
13750 return sprintf(page, "%s\n", pmu_attr->event_str);
13754 EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
13756 static int __init perf_event_sysfs_init(void)
13761 mutex_lock(&pmus_lock);
13763 ret = bus_register(&pmu_bus);
13767 list_for_each_entry(pmu, &pmus, entry) {
13771 ret = pmu_dev_alloc(pmu);
13772 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
13774 pmu_bus_running = 1;
13778 mutex_unlock(&pmus_lock);
13782 device_initcall(perf_event_sysfs_init);
13784 #ifdef CONFIG_CGROUP_PERF
13785 static struct cgroup_subsys_state *
13786 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
13788 struct perf_cgroup *jc;
13790 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
13792 return ERR_PTR(-ENOMEM);
13794 jc->info = alloc_percpu(struct perf_cgroup_info);
13797 return ERR_PTR(-ENOMEM);
13803 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
13805 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
13807 free_percpu(jc->info);
13811 static int perf_cgroup_css_online(struct cgroup_subsys_state *css)
13813 perf_event_cgroup(css->cgroup);
13817 static int __perf_cgroup_move(void *info)
13819 struct task_struct *task = info;
13822 perf_cgroup_switch(task);
13828 static void perf_cgroup_attach(struct cgroup_taskset *tset)
13830 struct task_struct *task;
13831 struct cgroup_subsys_state *css;
13833 cgroup_taskset_for_each(task, css, tset)
13834 task_function_call(task, __perf_cgroup_move, task);
13837 struct cgroup_subsys perf_event_cgrp_subsys = {
13838 .css_alloc = perf_cgroup_css_alloc,
13839 .css_free = perf_cgroup_css_free,
13840 .css_online = perf_cgroup_css_online,
13841 .attach = perf_cgroup_attach,
13843 * Implicitly enable on dfl hierarchy so that perf events can
13844 * always be filtered by cgroup2 path as long as perf_event
13845 * controller is not mounted on a legacy hierarchy.
13847 .implicit_on_dfl = true,
13850 #endif /* CONFIG_CGROUP_PERF */
13852 DEFINE_STATIC_CALL_RET0(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);