2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 lockdep_assert_irqs_disabled();
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 lockdep_assert_irqs_disabled();
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
392 static cpumask_var_t perf_online_mask
;
395 * perf event paranoia level:
396 * -1 - not paranoid at all
397 * 0 - disallow raw tracepoint access for unpriv
398 * 1 - disallow cpu events for unpriv
399 * 2 - disallow kernel profiling for unpriv
401 int sysctl_perf_event_paranoid __read_mostly
= 2;
403 /* Minimum for 512 kiB + 1 user control page */
404 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
407 * max perf event sample rate
409 #define DEFAULT_MAX_SAMPLE_RATE 100000
410 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
411 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
413 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
415 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
416 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
418 static int perf_sample_allowed_ns __read_mostly
=
419 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
421 static void update_perf_cpu_limits(void)
423 u64 tmp
= perf_sample_period_ns
;
425 tmp
*= sysctl_perf_cpu_time_max_percent
;
426 tmp
= div_u64(tmp
, 100);
430 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
433 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
435 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
436 void __user
*buffer
, size_t *lenp
,
439 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
445 * If throttling is disabled don't allow the write:
447 if (sysctl_perf_cpu_time_max_percent
== 100 ||
448 sysctl_perf_cpu_time_max_percent
== 0)
451 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
452 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
453 update_perf_cpu_limits();
458 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
460 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
461 void __user
*buffer
, size_t *lenp
,
464 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
469 if (sysctl_perf_cpu_time_max_percent
== 100 ||
470 sysctl_perf_cpu_time_max_percent
== 0) {
472 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
473 WRITE_ONCE(perf_sample_allowed_ns
, 0);
475 update_perf_cpu_limits();
482 * perf samples are done in some very critical code paths (NMIs).
483 * If they take too much CPU time, the system can lock up and not
484 * get any real work done. This will drop the sample rate when
485 * we detect that events are taking too long.
487 #define NR_ACCUMULATED_SAMPLES 128
488 static DEFINE_PER_CPU(u64
, running_sample_length
);
490 static u64 __report_avg
;
491 static u64 __report_allowed
;
493 static void perf_duration_warn(struct irq_work
*w
)
495 printk_ratelimited(KERN_INFO
496 "perf: interrupt took too long (%lld > %lld), lowering "
497 "kernel.perf_event_max_sample_rate to %d\n",
498 __report_avg
, __report_allowed
,
499 sysctl_perf_event_sample_rate
);
502 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
504 void perf_sample_event_took(u64 sample_len_ns
)
506 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
514 /* Decay the counter by 1 average sample. */
515 running_len
= __this_cpu_read(running_sample_length
);
516 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
517 running_len
+= sample_len_ns
;
518 __this_cpu_write(running_sample_length
, running_len
);
521 * Note: this will be biased artifically low until we have
522 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
523 * from having to maintain a count.
525 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
526 if (avg_len
<= max_len
)
529 __report_avg
= avg_len
;
530 __report_allowed
= max_len
;
533 * Compute a throttle threshold 25% below the current duration.
535 avg_len
+= avg_len
/ 4;
536 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
542 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
543 WRITE_ONCE(max_samples_per_tick
, max
);
545 sysctl_perf_event_sample_rate
= max
* HZ
;
546 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
548 if (!irq_work_queue(&perf_duration_work
)) {
549 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
550 "kernel.perf_event_max_sample_rate to %d\n",
551 __report_avg
, __report_allowed
,
552 sysctl_perf_event_sample_rate
);
556 static atomic64_t perf_event_id
;
558 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
559 enum event_type_t event_type
);
561 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
562 enum event_type_t event_type
,
563 struct task_struct
*task
);
565 static void update_context_time(struct perf_event_context
*ctx
);
566 static u64
perf_event_time(struct perf_event
*event
);
568 void __weak
perf_event_print_debug(void) { }
570 extern __weak
const char *perf_pmu_name(void)
575 static inline u64
perf_clock(void)
577 return local_clock();
580 static inline u64
perf_event_clock(struct perf_event
*event
)
582 return event
->clock();
586 * State based event timekeeping...
588 * The basic idea is to use event->state to determine which (if any) time
589 * fields to increment with the current delta. This means we only need to
590 * update timestamps when we change state or when they are explicitly requested
593 * Event groups make things a little more complicated, but not terribly so. The
594 * rules for a group are that if the group leader is OFF the entire group is
595 * OFF, irrespecive of what the group member states are. This results in
596 * __perf_effective_state().
598 * A futher ramification is that when a group leader flips between OFF and
599 * !OFF, we need to update all group member times.
602 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
603 * need to make sure the relevant context time is updated before we try and
604 * update our timestamps.
607 static __always_inline
enum perf_event_state
608 __perf_effective_state(struct perf_event
*event
)
610 struct perf_event
*leader
= event
->group_leader
;
612 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
613 return leader
->state
;
618 static __always_inline
void
619 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
621 enum perf_event_state state
= __perf_effective_state(event
);
622 u64 delta
= now
- event
->tstamp
;
624 *enabled
= event
->total_time_enabled
;
625 if (state
>= PERF_EVENT_STATE_INACTIVE
)
628 *running
= event
->total_time_running
;
629 if (state
>= PERF_EVENT_STATE_ACTIVE
)
633 static void perf_event_update_time(struct perf_event
*event
)
635 u64 now
= perf_event_time(event
);
637 __perf_update_times(event
, now
, &event
->total_time_enabled
,
638 &event
->total_time_running
);
642 static void perf_event_update_sibling_time(struct perf_event
*leader
)
644 struct perf_event
*sibling
;
646 list_for_each_entry(sibling
, &leader
->sibling_list
, group_entry
)
647 perf_event_update_time(sibling
);
651 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
653 if (event
->state
== state
)
656 perf_event_update_time(event
);
658 * If a group leader gets enabled/disabled all its siblings
661 if ((event
->state
< 0) ^ (state
< 0))
662 perf_event_update_sibling_time(event
);
664 WRITE_ONCE(event
->state
, state
);
667 #ifdef CONFIG_CGROUP_PERF
670 perf_cgroup_match(struct perf_event
*event
)
672 struct perf_event_context
*ctx
= event
->ctx
;
673 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
675 /* @event doesn't care about cgroup */
679 /* wants specific cgroup scope but @cpuctx isn't associated with any */
684 * Cgroup scoping is recursive. An event enabled for a cgroup is
685 * also enabled for all its descendant cgroups. If @cpuctx's
686 * cgroup is a descendant of @event's (the test covers identity
687 * case), it's a match.
689 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
690 event
->cgrp
->css
.cgroup
);
693 static inline void perf_detach_cgroup(struct perf_event
*event
)
695 css_put(&event
->cgrp
->css
);
699 static inline int is_cgroup_event(struct perf_event
*event
)
701 return event
->cgrp
!= NULL
;
704 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
706 struct perf_cgroup_info
*t
;
708 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
712 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
714 struct perf_cgroup_info
*info
;
719 info
= this_cpu_ptr(cgrp
->info
);
721 info
->time
+= now
- info
->timestamp
;
722 info
->timestamp
= now
;
725 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
727 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
729 __update_cgrp_time(cgrp_out
);
732 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
734 struct perf_cgroup
*cgrp
;
737 * ensure we access cgroup data only when needed and
738 * when we know the cgroup is pinned (css_get)
740 if (!is_cgroup_event(event
))
743 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
745 * Do not update time when cgroup is not active
747 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
748 __update_cgrp_time(event
->cgrp
);
752 perf_cgroup_set_timestamp(struct task_struct
*task
,
753 struct perf_event_context
*ctx
)
755 struct perf_cgroup
*cgrp
;
756 struct perf_cgroup_info
*info
;
759 * ctx->lock held by caller
760 * ensure we do not access cgroup data
761 * unless we have the cgroup pinned (css_get)
763 if (!task
|| !ctx
->nr_cgroups
)
766 cgrp
= perf_cgroup_from_task(task
, ctx
);
767 info
= this_cpu_ptr(cgrp
->info
);
768 info
->timestamp
= ctx
->timestamp
;
771 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
773 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
774 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
777 * reschedule events based on the cgroup constraint of task.
779 * mode SWOUT : schedule out everything
780 * mode SWIN : schedule in based on cgroup for next
782 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
784 struct perf_cpu_context
*cpuctx
;
785 struct list_head
*list
;
789 * Disable interrupts and preemption to avoid this CPU's
790 * cgrp_cpuctx_entry to change under us.
792 local_irq_save(flags
);
794 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
795 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
796 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
798 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
799 perf_pmu_disable(cpuctx
->ctx
.pmu
);
801 if (mode
& PERF_CGROUP_SWOUT
) {
802 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
804 * must not be done before ctxswout due
805 * to event_filter_match() in event_sched_out()
810 if (mode
& PERF_CGROUP_SWIN
) {
811 WARN_ON_ONCE(cpuctx
->cgrp
);
813 * set cgrp before ctxsw in to allow
814 * event_filter_match() to not have to pass
816 * we pass the cpuctx->ctx to perf_cgroup_from_task()
817 * because cgorup events are only per-cpu
819 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
821 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
823 perf_pmu_enable(cpuctx
->ctx
.pmu
);
824 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
827 local_irq_restore(flags
);
830 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
831 struct task_struct
*next
)
833 struct perf_cgroup
*cgrp1
;
834 struct perf_cgroup
*cgrp2
= NULL
;
838 * we come here when we know perf_cgroup_events > 0
839 * we do not need to pass the ctx here because we know
840 * we are holding the rcu lock
842 cgrp1
= perf_cgroup_from_task(task
, NULL
);
843 cgrp2
= perf_cgroup_from_task(next
, NULL
);
846 * only schedule out current cgroup events if we know
847 * that we are switching to a different cgroup. Otherwise,
848 * do no touch the cgroup events.
851 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
856 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
857 struct task_struct
*task
)
859 struct perf_cgroup
*cgrp1
;
860 struct perf_cgroup
*cgrp2
= NULL
;
864 * we come here when we know perf_cgroup_events > 0
865 * we do not need to pass the ctx here because we know
866 * we are holding the rcu lock
868 cgrp1
= perf_cgroup_from_task(task
, NULL
);
869 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
872 * only need to schedule in cgroup events if we are changing
873 * cgroup during ctxsw. Cgroup events were not scheduled
874 * out of ctxsw out if that was not the case.
877 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
882 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
883 struct perf_event_attr
*attr
,
884 struct perf_event
*group_leader
)
886 struct perf_cgroup
*cgrp
;
887 struct cgroup_subsys_state
*css
;
888 struct fd f
= fdget(fd
);
894 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
895 &perf_event_cgrp_subsys
);
901 cgrp
= container_of(css
, struct perf_cgroup
, css
);
905 * all events in a group must monitor
906 * the same cgroup because a task belongs
907 * to only one perf cgroup at a time
909 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
910 perf_detach_cgroup(event
);
919 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
921 struct perf_cgroup_info
*t
;
922 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
923 event
->shadow_ctx_time
= now
- t
->timestamp
;
927 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
928 * cleared when last cgroup event is removed.
931 list_update_cgroup_event(struct perf_event
*event
,
932 struct perf_event_context
*ctx
, bool add
)
934 struct perf_cpu_context
*cpuctx
;
935 struct list_head
*cpuctx_entry
;
937 if (!is_cgroup_event(event
))
940 if (add
&& ctx
->nr_cgroups
++)
942 else if (!add
&& --ctx
->nr_cgroups
)
945 * Because cgroup events are always per-cpu events,
946 * this will always be called from the right CPU.
948 cpuctx
= __get_cpu_context(ctx
);
949 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
950 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
952 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
954 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
955 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
958 list_del(cpuctx_entry
);
963 #else /* !CONFIG_CGROUP_PERF */
966 perf_cgroup_match(struct perf_event
*event
)
971 static inline void perf_detach_cgroup(struct perf_event
*event
)
974 static inline int is_cgroup_event(struct perf_event
*event
)
979 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
983 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
987 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
988 struct task_struct
*next
)
992 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
993 struct task_struct
*task
)
997 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
998 struct perf_event_attr
*attr
,
999 struct perf_event
*group_leader
)
1005 perf_cgroup_set_timestamp(struct task_struct
*task
,
1006 struct perf_event_context
*ctx
)
1011 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1016 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1020 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1026 list_update_cgroup_event(struct perf_event
*event
,
1027 struct perf_event_context
*ctx
, bool add
)
1034 * set default to be dependent on timer tick just
1035 * like original code
1037 #define PERF_CPU_HRTIMER (1000 / HZ)
1039 * function must be called with interrupts disabled
1041 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1043 struct perf_cpu_context
*cpuctx
;
1046 lockdep_assert_irqs_disabled();
1048 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1049 rotations
= perf_rotate_context(cpuctx
);
1051 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1053 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1055 cpuctx
->hrtimer_active
= 0;
1056 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1058 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1061 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1063 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1064 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1067 /* no multiplexing needed for SW PMU */
1068 if (pmu
->task_ctx_nr
== perf_sw_context
)
1072 * check default is sane, if not set then force to
1073 * default interval (1/tick)
1075 interval
= pmu
->hrtimer_interval_ms
;
1077 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1079 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1081 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1082 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1083 timer
->function
= perf_mux_hrtimer_handler
;
1086 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1088 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1089 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1090 unsigned long flags
;
1092 /* not for SW PMU */
1093 if (pmu
->task_ctx_nr
== perf_sw_context
)
1096 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1097 if (!cpuctx
->hrtimer_active
) {
1098 cpuctx
->hrtimer_active
= 1;
1099 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1100 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1102 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1107 void perf_pmu_disable(struct pmu
*pmu
)
1109 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1111 pmu
->pmu_disable(pmu
);
1114 void perf_pmu_enable(struct pmu
*pmu
)
1116 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1118 pmu
->pmu_enable(pmu
);
1121 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1124 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1125 * perf_event_task_tick() are fully serialized because they're strictly cpu
1126 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1127 * disabled, while perf_event_task_tick is called from IRQ context.
1129 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1131 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1133 lockdep_assert_irqs_disabled();
1135 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1137 list_add(&ctx
->active_ctx_list
, head
);
1140 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1142 lockdep_assert_irqs_disabled();
1144 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1146 list_del_init(&ctx
->active_ctx_list
);
1149 static void get_ctx(struct perf_event_context
*ctx
)
1151 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1154 static void free_ctx(struct rcu_head
*head
)
1156 struct perf_event_context
*ctx
;
1158 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1159 kfree(ctx
->task_ctx_data
);
1163 static void put_ctx(struct perf_event_context
*ctx
)
1165 if (atomic_dec_and_test(&ctx
->refcount
)) {
1166 if (ctx
->parent_ctx
)
1167 put_ctx(ctx
->parent_ctx
);
1168 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1169 put_task_struct(ctx
->task
);
1170 call_rcu(&ctx
->rcu_head
, free_ctx
);
1175 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1176 * perf_pmu_migrate_context() we need some magic.
1178 * Those places that change perf_event::ctx will hold both
1179 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1181 * Lock ordering is by mutex address. There are two other sites where
1182 * perf_event_context::mutex nests and those are:
1184 * - perf_event_exit_task_context() [ child , 0 ]
1185 * perf_event_exit_event()
1186 * put_event() [ parent, 1 ]
1188 * - perf_event_init_context() [ parent, 0 ]
1189 * inherit_task_group()
1192 * perf_event_alloc()
1194 * perf_try_init_event() [ child , 1 ]
1196 * While it appears there is an obvious deadlock here -- the parent and child
1197 * nesting levels are inverted between the two. This is in fact safe because
1198 * life-time rules separate them. That is an exiting task cannot fork, and a
1199 * spawning task cannot (yet) exit.
1201 * But remember that that these are parent<->child context relations, and
1202 * migration does not affect children, therefore these two orderings should not
1205 * The change in perf_event::ctx does not affect children (as claimed above)
1206 * because the sys_perf_event_open() case will install a new event and break
1207 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1208 * concerned with cpuctx and that doesn't have children.
1210 * The places that change perf_event::ctx will issue:
1212 * perf_remove_from_context();
1213 * synchronize_rcu();
1214 * perf_install_in_context();
1216 * to affect the change. The remove_from_context() + synchronize_rcu() should
1217 * quiesce the event, after which we can install it in the new location. This
1218 * means that only external vectors (perf_fops, prctl) can perturb the event
1219 * while in transit. Therefore all such accessors should also acquire
1220 * perf_event_context::mutex to serialize against this.
1222 * However; because event->ctx can change while we're waiting to acquire
1223 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1228 * task_struct::perf_event_mutex
1229 * perf_event_context::mutex
1230 * perf_event::child_mutex;
1231 * perf_event_context::lock
1232 * perf_event::mmap_mutex
1237 * cpuctx->mutex / perf_event_context::mutex
1239 static struct perf_event_context
*
1240 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1242 struct perf_event_context
*ctx
;
1246 ctx
= READ_ONCE(event
->ctx
);
1247 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1253 mutex_lock_nested(&ctx
->mutex
, nesting
);
1254 if (event
->ctx
!= ctx
) {
1255 mutex_unlock(&ctx
->mutex
);
1263 static inline struct perf_event_context
*
1264 perf_event_ctx_lock(struct perf_event
*event
)
1266 return perf_event_ctx_lock_nested(event
, 0);
1269 static void perf_event_ctx_unlock(struct perf_event
*event
,
1270 struct perf_event_context
*ctx
)
1272 mutex_unlock(&ctx
->mutex
);
1277 * This must be done under the ctx->lock, such as to serialize against
1278 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1279 * calling scheduler related locks and ctx->lock nests inside those.
1281 static __must_check
struct perf_event_context
*
1282 unclone_ctx(struct perf_event_context
*ctx
)
1284 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1286 lockdep_assert_held(&ctx
->lock
);
1289 ctx
->parent_ctx
= NULL
;
1295 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1300 * only top level events have the pid namespace they were created in
1303 event
= event
->parent
;
1305 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1306 /* avoid -1 if it is idle thread or runs in another ns */
1307 if (!nr
&& !pid_alive(p
))
1312 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1314 return perf_event_pid_type(event
, p
, __PIDTYPE_TGID
);
1317 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1319 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1323 * If we inherit events we want to return the parent event id
1326 static u64
primary_event_id(struct perf_event
*event
)
1331 id
= event
->parent
->id
;
1337 * Get the perf_event_context for a task and lock it.
1339 * This has to cope with with the fact that until it is locked,
1340 * the context could get moved to another task.
1342 static struct perf_event_context
*
1343 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1345 struct perf_event_context
*ctx
;
1349 * One of the few rules of preemptible RCU is that one cannot do
1350 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1351 * part of the read side critical section was irqs-enabled -- see
1352 * rcu_read_unlock_special().
1354 * Since ctx->lock nests under rq->lock we must ensure the entire read
1355 * side critical section has interrupts disabled.
1357 local_irq_save(*flags
);
1359 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1362 * If this context is a clone of another, it might
1363 * get swapped for another underneath us by
1364 * perf_event_task_sched_out, though the
1365 * rcu_read_lock() protects us from any context
1366 * getting freed. Lock the context and check if it
1367 * got swapped before we could get the lock, and retry
1368 * if so. If we locked the right context, then it
1369 * can't get swapped on us any more.
1371 raw_spin_lock(&ctx
->lock
);
1372 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1373 raw_spin_unlock(&ctx
->lock
);
1375 local_irq_restore(*flags
);
1379 if (ctx
->task
== TASK_TOMBSTONE
||
1380 !atomic_inc_not_zero(&ctx
->refcount
)) {
1381 raw_spin_unlock(&ctx
->lock
);
1384 WARN_ON_ONCE(ctx
->task
!= task
);
1389 local_irq_restore(*flags
);
1394 * Get the context for a task and increment its pin_count so it
1395 * can't get swapped to another task. This also increments its
1396 * reference count so that the context can't get freed.
1398 static struct perf_event_context
*
1399 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1401 struct perf_event_context
*ctx
;
1402 unsigned long flags
;
1404 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1407 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1412 static void perf_unpin_context(struct perf_event_context
*ctx
)
1414 unsigned long flags
;
1416 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1418 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1422 * Update the record of the current time in a context.
1424 static void update_context_time(struct perf_event_context
*ctx
)
1426 u64 now
= perf_clock();
1428 ctx
->time
+= now
- ctx
->timestamp
;
1429 ctx
->timestamp
= now
;
1432 static u64
perf_event_time(struct perf_event
*event
)
1434 struct perf_event_context
*ctx
= event
->ctx
;
1436 if (is_cgroup_event(event
))
1437 return perf_cgroup_event_time(event
);
1439 return ctx
? ctx
->time
: 0;
1442 static enum event_type_t
get_event_type(struct perf_event
*event
)
1444 struct perf_event_context
*ctx
= event
->ctx
;
1445 enum event_type_t event_type
;
1447 lockdep_assert_held(&ctx
->lock
);
1450 * It's 'group type', really, because if our group leader is
1451 * pinned, so are we.
1453 if (event
->group_leader
!= event
)
1454 event
= event
->group_leader
;
1456 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1458 event_type
|= EVENT_CPU
;
1463 static struct list_head
*
1464 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1466 if (event
->attr
.pinned
)
1467 return &ctx
->pinned_groups
;
1469 return &ctx
->flexible_groups
;
1473 * Add a event from the lists for its context.
1474 * Must be called with ctx->mutex and ctx->lock held.
1477 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1479 lockdep_assert_held(&ctx
->lock
);
1481 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1482 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1484 event
->tstamp
= perf_event_time(event
);
1487 * If we're a stand alone event or group leader, we go to the context
1488 * list, group events are kept attached to the group so that
1489 * perf_group_detach can, at all times, locate all siblings.
1491 if (event
->group_leader
== event
) {
1492 struct list_head
*list
;
1494 event
->group_caps
= event
->event_caps
;
1496 list
= ctx_group_list(event
, ctx
);
1497 list_add_tail(&event
->group_entry
, list
);
1500 list_update_cgroup_event(event
, ctx
, true);
1502 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1504 if (event
->attr
.inherit_stat
)
1511 * Initialize event state based on the perf_event_attr::disabled.
1513 static inline void perf_event__state_init(struct perf_event
*event
)
1515 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1516 PERF_EVENT_STATE_INACTIVE
;
1519 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1521 int entry
= sizeof(u64
); /* value */
1525 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1526 size
+= sizeof(u64
);
1528 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1529 size
+= sizeof(u64
);
1531 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1532 entry
+= sizeof(u64
);
1534 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1536 size
+= sizeof(u64
);
1540 event
->read_size
= size
;
1543 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1545 struct perf_sample_data
*data
;
1548 if (sample_type
& PERF_SAMPLE_IP
)
1549 size
+= sizeof(data
->ip
);
1551 if (sample_type
& PERF_SAMPLE_ADDR
)
1552 size
+= sizeof(data
->addr
);
1554 if (sample_type
& PERF_SAMPLE_PERIOD
)
1555 size
+= sizeof(data
->period
);
1557 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1558 size
+= sizeof(data
->weight
);
1560 if (sample_type
& PERF_SAMPLE_READ
)
1561 size
+= event
->read_size
;
1563 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1564 size
+= sizeof(data
->data_src
.val
);
1566 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1567 size
+= sizeof(data
->txn
);
1569 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1570 size
+= sizeof(data
->phys_addr
);
1572 event
->header_size
= size
;
1576 * Called at perf_event creation and when events are attached/detached from a
1579 static void perf_event__header_size(struct perf_event
*event
)
1581 __perf_event_read_size(event
,
1582 event
->group_leader
->nr_siblings
);
1583 __perf_event_header_size(event
, event
->attr
.sample_type
);
1586 static void perf_event__id_header_size(struct perf_event
*event
)
1588 struct perf_sample_data
*data
;
1589 u64 sample_type
= event
->attr
.sample_type
;
1592 if (sample_type
& PERF_SAMPLE_TID
)
1593 size
+= sizeof(data
->tid_entry
);
1595 if (sample_type
& PERF_SAMPLE_TIME
)
1596 size
+= sizeof(data
->time
);
1598 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1599 size
+= sizeof(data
->id
);
1601 if (sample_type
& PERF_SAMPLE_ID
)
1602 size
+= sizeof(data
->id
);
1604 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1605 size
+= sizeof(data
->stream_id
);
1607 if (sample_type
& PERF_SAMPLE_CPU
)
1608 size
+= sizeof(data
->cpu_entry
);
1610 event
->id_header_size
= size
;
1613 static bool perf_event_validate_size(struct perf_event
*event
)
1616 * The values computed here will be over-written when we actually
1619 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1620 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1621 perf_event__id_header_size(event
);
1624 * Sum the lot; should not exceed the 64k limit we have on records.
1625 * Conservative limit to allow for callchains and other variable fields.
1627 if (event
->read_size
+ event
->header_size
+
1628 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1634 static void perf_group_attach(struct perf_event
*event
)
1636 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1638 lockdep_assert_held(&event
->ctx
->lock
);
1641 * We can have double attach due to group movement in perf_event_open.
1643 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1646 event
->attach_state
|= PERF_ATTACH_GROUP
;
1648 if (group_leader
== event
)
1651 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1653 group_leader
->group_caps
&= event
->event_caps
;
1655 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1656 group_leader
->nr_siblings
++;
1658 perf_event__header_size(group_leader
);
1660 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1661 perf_event__header_size(pos
);
1665 * Remove a event from the lists for its context.
1666 * Must be called with ctx->mutex and ctx->lock held.
1669 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1671 WARN_ON_ONCE(event
->ctx
!= ctx
);
1672 lockdep_assert_held(&ctx
->lock
);
1675 * We can have double detach due to exit/hot-unplug + close.
1677 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1680 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1682 list_update_cgroup_event(event
, ctx
, false);
1685 if (event
->attr
.inherit_stat
)
1688 list_del_rcu(&event
->event_entry
);
1690 if (event
->group_leader
== event
)
1691 list_del_init(&event
->group_entry
);
1694 * If event was in error state, then keep it
1695 * that way, otherwise bogus counts will be
1696 * returned on read(). The only way to get out
1697 * of error state is by explicit re-enabling
1700 if (event
->state
> PERF_EVENT_STATE_OFF
)
1701 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1706 static void perf_group_detach(struct perf_event
*event
)
1708 struct perf_event
*sibling
, *tmp
;
1709 struct list_head
*list
= NULL
;
1711 lockdep_assert_held(&event
->ctx
->lock
);
1714 * We can have double detach due to exit/hot-unplug + close.
1716 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1719 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1722 * If this is a sibling, remove it from its group.
1724 if (event
->group_leader
!= event
) {
1725 list_del_init(&event
->group_entry
);
1726 event
->group_leader
->nr_siblings
--;
1730 if (!list_empty(&event
->group_entry
))
1731 list
= &event
->group_entry
;
1734 * If this was a group event with sibling events then
1735 * upgrade the siblings to singleton events by adding them
1736 * to whatever list we are on.
1738 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1740 list_move_tail(&sibling
->group_entry
, list
);
1741 sibling
->group_leader
= sibling
;
1743 /* Inherit group flags from the previous leader */
1744 sibling
->group_caps
= event
->group_caps
;
1746 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1750 perf_event__header_size(event
->group_leader
);
1752 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1753 perf_event__header_size(tmp
);
1756 static bool is_orphaned_event(struct perf_event
*event
)
1758 return event
->state
== PERF_EVENT_STATE_DEAD
;
1761 static inline int __pmu_filter_match(struct perf_event
*event
)
1763 struct pmu
*pmu
= event
->pmu
;
1764 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1768 * Check whether we should attempt to schedule an event group based on
1769 * PMU-specific filtering. An event group can consist of HW and SW events,
1770 * potentially with a SW leader, so we must check all the filters, to
1771 * determine whether a group is schedulable:
1773 static inline int pmu_filter_match(struct perf_event
*event
)
1775 struct perf_event
*child
;
1777 if (!__pmu_filter_match(event
))
1780 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1781 if (!__pmu_filter_match(child
))
1789 event_filter_match(struct perf_event
*event
)
1791 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1792 perf_cgroup_match(event
) && pmu_filter_match(event
);
1796 event_sched_out(struct perf_event
*event
,
1797 struct perf_cpu_context
*cpuctx
,
1798 struct perf_event_context
*ctx
)
1800 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
1802 WARN_ON_ONCE(event
->ctx
!= ctx
);
1803 lockdep_assert_held(&ctx
->lock
);
1805 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1808 perf_pmu_disable(event
->pmu
);
1810 event
->pmu
->del(event
, 0);
1813 if (event
->pending_disable
) {
1814 event
->pending_disable
= 0;
1815 state
= PERF_EVENT_STATE_OFF
;
1817 perf_event_set_state(event
, state
);
1819 if (!is_software_event(event
))
1820 cpuctx
->active_oncpu
--;
1821 if (!--ctx
->nr_active
)
1822 perf_event_ctx_deactivate(ctx
);
1823 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1825 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1826 cpuctx
->exclusive
= 0;
1828 perf_pmu_enable(event
->pmu
);
1832 group_sched_out(struct perf_event
*group_event
,
1833 struct perf_cpu_context
*cpuctx
,
1834 struct perf_event_context
*ctx
)
1836 struct perf_event
*event
;
1838 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1841 perf_pmu_disable(ctx
->pmu
);
1843 event_sched_out(group_event
, cpuctx
, ctx
);
1846 * Schedule out siblings (if any):
1848 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1849 event_sched_out(event
, cpuctx
, ctx
);
1851 perf_pmu_enable(ctx
->pmu
);
1853 if (group_event
->attr
.exclusive
)
1854 cpuctx
->exclusive
= 0;
1857 #define DETACH_GROUP 0x01UL
1860 * Cross CPU call to remove a performance event
1862 * We disable the event on the hardware level first. After that we
1863 * remove it from the context list.
1866 __perf_remove_from_context(struct perf_event
*event
,
1867 struct perf_cpu_context
*cpuctx
,
1868 struct perf_event_context
*ctx
,
1871 unsigned long flags
= (unsigned long)info
;
1873 if (ctx
->is_active
& EVENT_TIME
) {
1874 update_context_time(ctx
);
1875 update_cgrp_time_from_cpuctx(cpuctx
);
1878 event_sched_out(event
, cpuctx
, ctx
);
1879 if (flags
& DETACH_GROUP
)
1880 perf_group_detach(event
);
1881 list_del_event(event
, ctx
);
1883 if (!ctx
->nr_events
&& ctx
->is_active
) {
1886 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1887 cpuctx
->task_ctx
= NULL
;
1893 * Remove the event from a task's (or a CPU's) list of events.
1895 * If event->ctx is a cloned context, callers must make sure that
1896 * every task struct that event->ctx->task could possibly point to
1897 * remains valid. This is OK when called from perf_release since
1898 * that only calls us on the top-level context, which can't be a clone.
1899 * When called from perf_event_exit_task, it's OK because the
1900 * context has been detached from its task.
1902 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1904 struct perf_event_context
*ctx
= event
->ctx
;
1906 lockdep_assert_held(&ctx
->mutex
);
1908 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1911 * The above event_function_call() can NO-OP when it hits
1912 * TASK_TOMBSTONE. In that case we must already have been detached
1913 * from the context (by perf_event_exit_event()) but the grouping
1914 * might still be in-tact.
1916 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1917 if ((flags
& DETACH_GROUP
) &&
1918 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1920 * Since in that case we cannot possibly be scheduled, simply
1923 raw_spin_lock_irq(&ctx
->lock
);
1924 perf_group_detach(event
);
1925 raw_spin_unlock_irq(&ctx
->lock
);
1930 * Cross CPU call to disable a performance event
1932 static void __perf_event_disable(struct perf_event
*event
,
1933 struct perf_cpu_context
*cpuctx
,
1934 struct perf_event_context
*ctx
,
1937 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1940 if (ctx
->is_active
& EVENT_TIME
) {
1941 update_context_time(ctx
);
1942 update_cgrp_time_from_event(event
);
1945 if (event
== event
->group_leader
)
1946 group_sched_out(event
, cpuctx
, ctx
);
1948 event_sched_out(event
, cpuctx
, ctx
);
1950 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1956 * If event->ctx is a cloned context, callers must make sure that
1957 * every task struct that event->ctx->task could possibly point to
1958 * remains valid. This condition is satisifed when called through
1959 * perf_event_for_each_child or perf_event_for_each because they
1960 * hold the top-level event's child_mutex, so any descendant that
1961 * goes to exit will block in perf_event_exit_event().
1963 * When called from perf_pending_event it's OK because event->ctx
1964 * is the current context on this CPU and preemption is disabled,
1965 * hence we can't get into perf_event_task_sched_out for this context.
1967 static void _perf_event_disable(struct perf_event
*event
)
1969 struct perf_event_context
*ctx
= event
->ctx
;
1971 raw_spin_lock_irq(&ctx
->lock
);
1972 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1973 raw_spin_unlock_irq(&ctx
->lock
);
1976 raw_spin_unlock_irq(&ctx
->lock
);
1978 event_function_call(event
, __perf_event_disable
, NULL
);
1981 void perf_event_disable_local(struct perf_event
*event
)
1983 event_function_local(event
, __perf_event_disable
, NULL
);
1987 * Strictly speaking kernel users cannot create groups and therefore this
1988 * interface does not need the perf_event_ctx_lock() magic.
1990 void perf_event_disable(struct perf_event
*event
)
1992 struct perf_event_context
*ctx
;
1994 ctx
= perf_event_ctx_lock(event
);
1995 _perf_event_disable(event
);
1996 perf_event_ctx_unlock(event
, ctx
);
1998 EXPORT_SYMBOL_GPL(perf_event_disable
);
2000 void perf_event_disable_inatomic(struct perf_event
*event
)
2002 event
->pending_disable
= 1;
2003 irq_work_queue(&event
->pending
);
2006 static void perf_set_shadow_time(struct perf_event
*event
,
2007 struct perf_event_context
*ctx
)
2010 * use the correct time source for the time snapshot
2012 * We could get by without this by leveraging the
2013 * fact that to get to this function, the caller
2014 * has most likely already called update_context_time()
2015 * and update_cgrp_time_xx() and thus both timestamp
2016 * are identical (or very close). Given that tstamp is,
2017 * already adjusted for cgroup, we could say that:
2018 * tstamp - ctx->timestamp
2020 * tstamp - cgrp->timestamp.
2022 * Then, in perf_output_read(), the calculation would
2023 * work with no changes because:
2024 * - event is guaranteed scheduled in
2025 * - no scheduled out in between
2026 * - thus the timestamp would be the same
2028 * But this is a bit hairy.
2030 * So instead, we have an explicit cgroup call to remain
2031 * within the time time source all along. We believe it
2032 * is cleaner and simpler to understand.
2034 if (is_cgroup_event(event
))
2035 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2037 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2040 #define MAX_INTERRUPTS (~0ULL)
2042 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2043 static void perf_log_itrace_start(struct perf_event
*event
);
2046 event_sched_in(struct perf_event
*event
,
2047 struct perf_cpu_context
*cpuctx
,
2048 struct perf_event_context
*ctx
)
2052 lockdep_assert_held(&ctx
->lock
);
2054 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2057 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2059 * Order event::oncpu write to happen before the ACTIVE state is
2060 * visible. This allows perf_event_{stop,read}() to observe the correct
2061 * ->oncpu if it sees ACTIVE.
2064 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2067 * Unthrottle events, since we scheduled we might have missed several
2068 * ticks already, also for a heavily scheduling task there is little
2069 * guarantee it'll get a tick in a timely manner.
2071 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2072 perf_log_throttle(event
, 1);
2073 event
->hw
.interrupts
= 0;
2076 perf_pmu_disable(event
->pmu
);
2078 perf_set_shadow_time(event
, ctx
);
2080 perf_log_itrace_start(event
);
2082 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2083 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2089 if (!is_software_event(event
))
2090 cpuctx
->active_oncpu
++;
2091 if (!ctx
->nr_active
++)
2092 perf_event_ctx_activate(ctx
);
2093 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2096 if (event
->attr
.exclusive
)
2097 cpuctx
->exclusive
= 1;
2100 perf_pmu_enable(event
->pmu
);
2106 group_sched_in(struct perf_event
*group_event
,
2107 struct perf_cpu_context
*cpuctx
,
2108 struct perf_event_context
*ctx
)
2110 struct perf_event
*event
, *partial_group
= NULL
;
2111 struct pmu
*pmu
= ctx
->pmu
;
2113 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2116 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2118 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2119 pmu
->cancel_txn(pmu
);
2120 perf_mux_hrtimer_restart(cpuctx
);
2125 * Schedule in siblings as one group (if any):
2127 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2128 if (event_sched_in(event
, cpuctx
, ctx
)) {
2129 partial_group
= event
;
2134 if (!pmu
->commit_txn(pmu
))
2139 * Groups can be scheduled in as one unit only, so undo any
2140 * partial group before returning:
2141 * The events up to the failed event are scheduled out normally.
2143 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2144 if (event
== partial_group
)
2147 event_sched_out(event
, cpuctx
, ctx
);
2149 event_sched_out(group_event
, cpuctx
, ctx
);
2151 pmu
->cancel_txn(pmu
);
2153 perf_mux_hrtimer_restart(cpuctx
);
2159 * Work out whether we can put this event group on the CPU now.
2161 static int group_can_go_on(struct perf_event
*event
,
2162 struct perf_cpu_context
*cpuctx
,
2166 * Groups consisting entirely of software events can always go on.
2168 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2171 * If an exclusive group is already on, no other hardware
2174 if (cpuctx
->exclusive
)
2177 * If this group is exclusive and there are already
2178 * events on the CPU, it can't go on.
2180 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2183 * Otherwise, try to add it if all previous groups were able
2189 static void add_event_to_ctx(struct perf_event
*event
,
2190 struct perf_event_context
*ctx
)
2192 list_add_event(event
, ctx
);
2193 perf_group_attach(event
);
2196 static void ctx_sched_out(struct perf_event_context
*ctx
,
2197 struct perf_cpu_context
*cpuctx
,
2198 enum event_type_t event_type
);
2200 ctx_sched_in(struct perf_event_context
*ctx
,
2201 struct perf_cpu_context
*cpuctx
,
2202 enum event_type_t event_type
,
2203 struct task_struct
*task
);
2205 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2206 struct perf_event_context
*ctx
,
2207 enum event_type_t event_type
)
2209 if (!cpuctx
->task_ctx
)
2212 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2215 ctx_sched_out(ctx
, cpuctx
, event_type
);
2218 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2219 struct perf_event_context
*ctx
,
2220 struct task_struct
*task
)
2222 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2224 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2225 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2227 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2231 * We want to maintain the following priority of scheduling:
2232 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2233 * - task pinned (EVENT_PINNED)
2234 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2235 * - task flexible (EVENT_FLEXIBLE).
2237 * In order to avoid unscheduling and scheduling back in everything every
2238 * time an event is added, only do it for the groups of equal priority and
2241 * This can be called after a batch operation on task events, in which case
2242 * event_type is a bit mask of the types of events involved. For CPU events,
2243 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2245 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2246 struct perf_event_context
*task_ctx
,
2247 enum event_type_t event_type
)
2249 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2250 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2253 * If pinned groups are involved, flexible groups also need to be
2256 if (event_type
& EVENT_PINNED
)
2257 event_type
|= EVENT_FLEXIBLE
;
2259 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2261 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2264 * Decide which cpu ctx groups to schedule out based on the types
2265 * of events that caused rescheduling:
2266 * - EVENT_CPU: schedule out corresponding groups;
2267 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2268 * - otherwise, do nothing more.
2271 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2272 else if (ctx_event_type
& EVENT_PINNED
)
2273 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2275 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2276 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2280 * Cross CPU call to install and enable a performance event
2282 * Very similar to remote_function() + event_function() but cannot assume that
2283 * things like ctx->is_active and cpuctx->task_ctx are set.
2285 static int __perf_install_in_context(void *info
)
2287 struct perf_event
*event
= info
;
2288 struct perf_event_context
*ctx
= event
->ctx
;
2289 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2290 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2291 bool reprogram
= true;
2294 raw_spin_lock(&cpuctx
->ctx
.lock
);
2296 raw_spin_lock(&ctx
->lock
);
2299 reprogram
= (ctx
->task
== current
);
2302 * If the task is running, it must be running on this CPU,
2303 * otherwise we cannot reprogram things.
2305 * If its not running, we don't care, ctx->lock will
2306 * serialize against it becoming runnable.
2308 if (task_curr(ctx
->task
) && !reprogram
) {
2313 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2314 } else if (task_ctx
) {
2315 raw_spin_lock(&task_ctx
->lock
);
2319 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2320 add_event_to_ctx(event
, ctx
);
2321 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2323 add_event_to_ctx(event
, ctx
);
2327 perf_ctx_unlock(cpuctx
, task_ctx
);
2333 * Attach a performance event to a context.
2335 * Very similar to event_function_call, see comment there.
2338 perf_install_in_context(struct perf_event_context
*ctx
,
2339 struct perf_event
*event
,
2342 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2344 lockdep_assert_held(&ctx
->mutex
);
2346 if (event
->cpu
!= -1)
2350 * Ensures that if we can observe event->ctx, both the event and ctx
2351 * will be 'complete'. See perf_iterate_sb_cpu().
2353 smp_store_release(&event
->ctx
, ctx
);
2356 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2361 * Should not happen, we validate the ctx is still alive before calling.
2363 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2367 * Installing events is tricky because we cannot rely on ctx->is_active
2368 * to be set in case this is the nr_events 0 -> 1 transition.
2370 * Instead we use task_curr(), which tells us if the task is running.
2371 * However, since we use task_curr() outside of rq::lock, we can race
2372 * against the actual state. This means the result can be wrong.
2374 * If we get a false positive, we retry, this is harmless.
2376 * If we get a false negative, things are complicated. If we are after
2377 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2378 * value must be correct. If we're before, it doesn't matter since
2379 * perf_event_context_sched_in() will program the counter.
2381 * However, this hinges on the remote context switch having observed
2382 * our task->perf_event_ctxp[] store, such that it will in fact take
2383 * ctx::lock in perf_event_context_sched_in().
2385 * We do this by task_function_call(), if the IPI fails to hit the task
2386 * we know any future context switch of task must see the
2387 * perf_event_ctpx[] store.
2391 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2392 * task_cpu() load, such that if the IPI then does not find the task
2393 * running, a future context switch of that task must observe the
2398 if (!task_function_call(task
, __perf_install_in_context
, event
))
2401 raw_spin_lock_irq(&ctx
->lock
);
2403 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2405 * Cannot happen because we already checked above (which also
2406 * cannot happen), and we hold ctx->mutex, which serializes us
2407 * against perf_event_exit_task_context().
2409 raw_spin_unlock_irq(&ctx
->lock
);
2413 * If the task is not running, ctx->lock will avoid it becoming so,
2414 * thus we can safely install the event.
2416 if (task_curr(task
)) {
2417 raw_spin_unlock_irq(&ctx
->lock
);
2420 add_event_to_ctx(event
, ctx
);
2421 raw_spin_unlock_irq(&ctx
->lock
);
2425 * Cross CPU call to enable a performance event
2427 static void __perf_event_enable(struct perf_event
*event
,
2428 struct perf_cpu_context
*cpuctx
,
2429 struct perf_event_context
*ctx
,
2432 struct perf_event
*leader
= event
->group_leader
;
2433 struct perf_event_context
*task_ctx
;
2435 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2436 event
->state
<= PERF_EVENT_STATE_ERROR
)
2440 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2442 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2444 if (!ctx
->is_active
)
2447 if (!event_filter_match(event
)) {
2448 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2453 * If the event is in a group and isn't the group leader,
2454 * then don't put it on unless the group is on.
2456 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2457 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2461 task_ctx
= cpuctx
->task_ctx
;
2463 WARN_ON_ONCE(task_ctx
!= ctx
);
2465 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2471 * If event->ctx is a cloned context, callers must make sure that
2472 * every task struct that event->ctx->task could possibly point to
2473 * remains valid. This condition is satisfied when called through
2474 * perf_event_for_each_child or perf_event_for_each as described
2475 * for perf_event_disable.
2477 static void _perf_event_enable(struct perf_event
*event
)
2479 struct perf_event_context
*ctx
= event
->ctx
;
2481 raw_spin_lock_irq(&ctx
->lock
);
2482 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2483 event
->state
< PERF_EVENT_STATE_ERROR
) {
2484 raw_spin_unlock_irq(&ctx
->lock
);
2489 * If the event is in error state, clear that first.
2491 * That way, if we see the event in error state below, we know that it
2492 * has gone back into error state, as distinct from the task having
2493 * been scheduled away before the cross-call arrived.
2495 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2496 event
->state
= PERF_EVENT_STATE_OFF
;
2497 raw_spin_unlock_irq(&ctx
->lock
);
2499 event_function_call(event
, __perf_event_enable
, NULL
);
2503 * See perf_event_disable();
2505 void perf_event_enable(struct perf_event
*event
)
2507 struct perf_event_context
*ctx
;
2509 ctx
= perf_event_ctx_lock(event
);
2510 _perf_event_enable(event
);
2511 perf_event_ctx_unlock(event
, ctx
);
2513 EXPORT_SYMBOL_GPL(perf_event_enable
);
2515 struct stop_event_data
{
2516 struct perf_event
*event
;
2517 unsigned int restart
;
2520 static int __perf_event_stop(void *info
)
2522 struct stop_event_data
*sd
= info
;
2523 struct perf_event
*event
= sd
->event
;
2525 /* if it's already INACTIVE, do nothing */
2526 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2529 /* matches smp_wmb() in event_sched_in() */
2533 * There is a window with interrupts enabled before we get here,
2534 * so we need to check again lest we try to stop another CPU's event.
2536 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2539 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2542 * May race with the actual stop (through perf_pmu_output_stop()),
2543 * but it is only used for events with AUX ring buffer, and such
2544 * events will refuse to restart because of rb::aux_mmap_count==0,
2545 * see comments in perf_aux_output_begin().
2547 * Since this is happening on a event-local CPU, no trace is lost
2551 event
->pmu
->start(event
, 0);
2556 static int perf_event_stop(struct perf_event
*event
, int restart
)
2558 struct stop_event_data sd
= {
2565 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2568 /* matches smp_wmb() in event_sched_in() */
2572 * We only want to restart ACTIVE events, so if the event goes
2573 * inactive here (event->oncpu==-1), there's nothing more to do;
2574 * fall through with ret==-ENXIO.
2576 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2577 __perf_event_stop
, &sd
);
2578 } while (ret
== -EAGAIN
);
2584 * In order to contain the amount of racy and tricky in the address filter
2585 * configuration management, it is a two part process:
2587 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2588 * we update the addresses of corresponding vmas in
2589 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2590 * (p2) when an event is scheduled in (pmu::add), it calls
2591 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2592 * if the generation has changed since the previous call.
2594 * If (p1) happens while the event is active, we restart it to force (p2).
2596 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2597 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2599 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2600 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2602 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2605 void perf_event_addr_filters_sync(struct perf_event
*event
)
2607 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2609 if (!has_addr_filter(event
))
2612 raw_spin_lock(&ifh
->lock
);
2613 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2614 event
->pmu
->addr_filters_sync(event
);
2615 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2617 raw_spin_unlock(&ifh
->lock
);
2619 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2621 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2624 * not supported on inherited events
2626 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2629 atomic_add(refresh
, &event
->event_limit
);
2630 _perf_event_enable(event
);
2636 * See perf_event_disable()
2638 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2640 struct perf_event_context
*ctx
;
2643 ctx
= perf_event_ctx_lock(event
);
2644 ret
= _perf_event_refresh(event
, refresh
);
2645 perf_event_ctx_unlock(event
, ctx
);
2649 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2651 static void ctx_sched_out(struct perf_event_context
*ctx
,
2652 struct perf_cpu_context
*cpuctx
,
2653 enum event_type_t event_type
)
2655 int is_active
= ctx
->is_active
;
2656 struct perf_event
*event
;
2658 lockdep_assert_held(&ctx
->lock
);
2660 if (likely(!ctx
->nr_events
)) {
2662 * See __perf_remove_from_context().
2664 WARN_ON_ONCE(ctx
->is_active
);
2666 WARN_ON_ONCE(cpuctx
->task_ctx
);
2670 ctx
->is_active
&= ~event_type
;
2671 if (!(ctx
->is_active
& EVENT_ALL
))
2675 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2676 if (!ctx
->is_active
)
2677 cpuctx
->task_ctx
= NULL
;
2681 * Always update time if it was set; not only when it changes.
2682 * Otherwise we can 'forget' to update time for any but the last
2683 * context we sched out. For example:
2685 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2686 * ctx_sched_out(.event_type = EVENT_PINNED)
2688 * would only update time for the pinned events.
2690 if (is_active
& EVENT_TIME
) {
2691 /* update (and stop) ctx time */
2692 update_context_time(ctx
);
2693 update_cgrp_time_from_cpuctx(cpuctx
);
2696 is_active
^= ctx
->is_active
; /* changed bits */
2698 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2701 perf_pmu_disable(ctx
->pmu
);
2702 if (is_active
& EVENT_PINNED
) {
2703 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2704 group_sched_out(event
, cpuctx
, ctx
);
2707 if (is_active
& EVENT_FLEXIBLE
) {
2708 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2709 group_sched_out(event
, cpuctx
, ctx
);
2711 perf_pmu_enable(ctx
->pmu
);
2715 * Test whether two contexts are equivalent, i.e. whether they have both been
2716 * cloned from the same version of the same context.
2718 * Equivalence is measured using a generation number in the context that is
2719 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2720 * and list_del_event().
2722 static int context_equiv(struct perf_event_context
*ctx1
,
2723 struct perf_event_context
*ctx2
)
2725 lockdep_assert_held(&ctx1
->lock
);
2726 lockdep_assert_held(&ctx2
->lock
);
2728 /* Pinning disables the swap optimization */
2729 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2732 /* If ctx1 is the parent of ctx2 */
2733 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2736 /* If ctx2 is the parent of ctx1 */
2737 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2741 * If ctx1 and ctx2 have the same parent; we flatten the parent
2742 * hierarchy, see perf_event_init_context().
2744 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2745 ctx1
->parent_gen
== ctx2
->parent_gen
)
2752 static void __perf_event_sync_stat(struct perf_event
*event
,
2753 struct perf_event
*next_event
)
2757 if (!event
->attr
.inherit_stat
)
2761 * Update the event value, we cannot use perf_event_read()
2762 * because we're in the middle of a context switch and have IRQs
2763 * disabled, which upsets smp_call_function_single(), however
2764 * we know the event must be on the current CPU, therefore we
2765 * don't need to use it.
2767 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2768 event
->pmu
->read(event
);
2770 perf_event_update_time(event
);
2773 * In order to keep per-task stats reliable we need to flip the event
2774 * values when we flip the contexts.
2776 value
= local64_read(&next_event
->count
);
2777 value
= local64_xchg(&event
->count
, value
);
2778 local64_set(&next_event
->count
, value
);
2780 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2781 swap(event
->total_time_running
, next_event
->total_time_running
);
2784 * Since we swizzled the values, update the user visible data too.
2786 perf_event_update_userpage(event
);
2787 perf_event_update_userpage(next_event
);
2790 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2791 struct perf_event_context
*next_ctx
)
2793 struct perf_event
*event
, *next_event
;
2798 update_context_time(ctx
);
2800 event
= list_first_entry(&ctx
->event_list
,
2801 struct perf_event
, event_entry
);
2803 next_event
= list_first_entry(&next_ctx
->event_list
,
2804 struct perf_event
, event_entry
);
2806 while (&event
->event_entry
!= &ctx
->event_list
&&
2807 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2809 __perf_event_sync_stat(event
, next_event
);
2811 event
= list_next_entry(event
, event_entry
);
2812 next_event
= list_next_entry(next_event
, event_entry
);
2816 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2817 struct task_struct
*next
)
2819 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2820 struct perf_event_context
*next_ctx
;
2821 struct perf_event_context
*parent
, *next_parent
;
2822 struct perf_cpu_context
*cpuctx
;
2828 cpuctx
= __get_cpu_context(ctx
);
2829 if (!cpuctx
->task_ctx
)
2833 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2837 parent
= rcu_dereference(ctx
->parent_ctx
);
2838 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2840 /* If neither context have a parent context; they cannot be clones. */
2841 if (!parent
&& !next_parent
)
2844 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2846 * Looks like the two contexts are clones, so we might be
2847 * able to optimize the context switch. We lock both
2848 * contexts and check that they are clones under the
2849 * lock (including re-checking that neither has been
2850 * uncloned in the meantime). It doesn't matter which
2851 * order we take the locks because no other cpu could
2852 * be trying to lock both of these tasks.
2854 raw_spin_lock(&ctx
->lock
);
2855 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2856 if (context_equiv(ctx
, next_ctx
)) {
2857 WRITE_ONCE(ctx
->task
, next
);
2858 WRITE_ONCE(next_ctx
->task
, task
);
2860 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2863 * RCU_INIT_POINTER here is safe because we've not
2864 * modified the ctx and the above modification of
2865 * ctx->task and ctx->task_ctx_data are immaterial
2866 * since those values are always verified under
2867 * ctx->lock which we're now holding.
2869 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2870 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2874 perf_event_sync_stat(ctx
, next_ctx
);
2876 raw_spin_unlock(&next_ctx
->lock
);
2877 raw_spin_unlock(&ctx
->lock
);
2883 raw_spin_lock(&ctx
->lock
);
2884 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2885 raw_spin_unlock(&ctx
->lock
);
2889 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2891 void perf_sched_cb_dec(struct pmu
*pmu
)
2893 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2895 this_cpu_dec(perf_sched_cb_usages
);
2897 if (!--cpuctx
->sched_cb_usage
)
2898 list_del(&cpuctx
->sched_cb_entry
);
2902 void perf_sched_cb_inc(struct pmu
*pmu
)
2904 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2906 if (!cpuctx
->sched_cb_usage
++)
2907 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2909 this_cpu_inc(perf_sched_cb_usages
);
2913 * This function provides the context switch callback to the lower code
2914 * layer. It is invoked ONLY when the context switch callback is enabled.
2916 * This callback is relevant even to per-cpu events; for example multi event
2917 * PEBS requires this to provide PID/TID information. This requires we flush
2918 * all queued PEBS records before we context switch to a new task.
2920 static void perf_pmu_sched_task(struct task_struct
*prev
,
2921 struct task_struct
*next
,
2924 struct perf_cpu_context
*cpuctx
;
2930 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2931 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2933 if (WARN_ON_ONCE(!pmu
->sched_task
))
2936 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2937 perf_pmu_disable(pmu
);
2939 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2941 perf_pmu_enable(pmu
);
2942 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2946 static void perf_event_switch(struct task_struct
*task
,
2947 struct task_struct
*next_prev
, bool sched_in
);
2949 #define for_each_task_context_nr(ctxn) \
2950 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2953 * Called from scheduler to remove the events of the current task,
2954 * with interrupts disabled.
2956 * We stop each event and update the event value in event->count.
2958 * This does not protect us against NMI, but disable()
2959 * sets the disabled bit in the control field of event _before_
2960 * accessing the event control register. If a NMI hits, then it will
2961 * not restart the event.
2963 void __perf_event_task_sched_out(struct task_struct
*task
,
2964 struct task_struct
*next
)
2968 if (__this_cpu_read(perf_sched_cb_usages
))
2969 perf_pmu_sched_task(task
, next
, false);
2971 if (atomic_read(&nr_switch_events
))
2972 perf_event_switch(task
, next
, false);
2974 for_each_task_context_nr(ctxn
)
2975 perf_event_context_sched_out(task
, ctxn
, next
);
2978 * if cgroup events exist on this CPU, then we need
2979 * to check if we have to switch out PMU state.
2980 * cgroup event are system-wide mode only
2982 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2983 perf_cgroup_sched_out(task
, next
);
2987 * Called with IRQs disabled
2989 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2990 enum event_type_t event_type
)
2992 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2996 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2997 struct perf_cpu_context
*cpuctx
)
2999 struct perf_event
*event
;
3001 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3002 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3004 if (!event_filter_match(event
))
3007 if (group_can_go_on(event
, cpuctx
, 1))
3008 group_sched_in(event
, cpuctx
, ctx
);
3011 * If this pinned group hasn't been scheduled,
3012 * put it in error state.
3014 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3015 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3020 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3021 struct perf_cpu_context
*cpuctx
)
3023 struct perf_event
*event
;
3026 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3027 /* Ignore events in OFF or ERROR state */
3028 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3031 * Listen to the 'cpu' scheduling filter constraint
3034 if (!event_filter_match(event
))
3037 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3038 if (group_sched_in(event
, cpuctx
, ctx
))
3045 ctx_sched_in(struct perf_event_context
*ctx
,
3046 struct perf_cpu_context
*cpuctx
,
3047 enum event_type_t event_type
,
3048 struct task_struct
*task
)
3050 int is_active
= ctx
->is_active
;
3053 lockdep_assert_held(&ctx
->lock
);
3055 if (likely(!ctx
->nr_events
))
3058 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3061 cpuctx
->task_ctx
= ctx
;
3063 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3066 is_active
^= ctx
->is_active
; /* changed bits */
3068 if (is_active
& EVENT_TIME
) {
3069 /* start ctx time */
3071 ctx
->timestamp
= now
;
3072 perf_cgroup_set_timestamp(task
, ctx
);
3076 * First go through the list and put on any pinned groups
3077 * in order to give them the best chance of going on.
3079 if (is_active
& EVENT_PINNED
)
3080 ctx_pinned_sched_in(ctx
, cpuctx
);
3082 /* Then walk through the lower prio flexible groups */
3083 if (is_active
& EVENT_FLEXIBLE
)
3084 ctx_flexible_sched_in(ctx
, cpuctx
);
3087 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3088 enum event_type_t event_type
,
3089 struct task_struct
*task
)
3091 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3093 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3096 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3097 struct task_struct
*task
)
3099 struct perf_cpu_context
*cpuctx
;
3101 cpuctx
= __get_cpu_context(ctx
);
3102 if (cpuctx
->task_ctx
== ctx
)
3105 perf_ctx_lock(cpuctx
, ctx
);
3107 * We must check ctx->nr_events while holding ctx->lock, such
3108 * that we serialize against perf_install_in_context().
3110 if (!ctx
->nr_events
)
3113 perf_pmu_disable(ctx
->pmu
);
3115 * We want to keep the following priority order:
3116 * cpu pinned (that don't need to move), task pinned,
3117 * cpu flexible, task flexible.
3119 * However, if task's ctx is not carrying any pinned
3120 * events, no need to flip the cpuctx's events around.
3122 if (!list_empty(&ctx
->pinned_groups
))
3123 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3124 perf_event_sched_in(cpuctx
, ctx
, task
);
3125 perf_pmu_enable(ctx
->pmu
);
3128 perf_ctx_unlock(cpuctx
, ctx
);
3132 * Called from scheduler to add the events of the current task
3133 * with interrupts disabled.
3135 * We restore the event value and then enable it.
3137 * This does not protect us against NMI, but enable()
3138 * sets the enabled bit in the control field of event _before_
3139 * accessing the event control register. If a NMI hits, then it will
3140 * keep the event running.
3142 void __perf_event_task_sched_in(struct task_struct
*prev
,
3143 struct task_struct
*task
)
3145 struct perf_event_context
*ctx
;
3149 * If cgroup events exist on this CPU, then we need to check if we have
3150 * to switch in PMU state; cgroup event are system-wide mode only.
3152 * Since cgroup events are CPU events, we must schedule these in before
3153 * we schedule in the task events.
3155 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3156 perf_cgroup_sched_in(prev
, task
);
3158 for_each_task_context_nr(ctxn
) {
3159 ctx
= task
->perf_event_ctxp
[ctxn
];
3163 perf_event_context_sched_in(ctx
, task
);
3166 if (atomic_read(&nr_switch_events
))
3167 perf_event_switch(task
, prev
, true);
3169 if (__this_cpu_read(perf_sched_cb_usages
))
3170 perf_pmu_sched_task(prev
, task
, true);
3173 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3175 u64 frequency
= event
->attr
.sample_freq
;
3176 u64 sec
= NSEC_PER_SEC
;
3177 u64 divisor
, dividend
;
3179 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3181 count_fls
= fls64(count
);
3182 nsec_fls
= fls64(nsec
);
3183 frequency_fls
= fls64(frequency
);
3187 * We got @count in @nsec, with a target of sample_freq HZ
3188 * the target period becomes:
3191 * period = -------------------
3192 * @nsec * sample_freq
3197 * Reduce accuracy by one bit such that @a and @b converge
3198 * to a similar magnitude.
3200 #define REDUCE_FLS(a, b) \
3202 if (a##_fls > b##_fls) { \
3212 * Reduce accuracy until either term fits in a u64, then proceed with
3213 * the other, so that finally we can do a u64/u64 division.
3215 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3216 REDUCE_FLS(nsec
, frequency
);
3217 REDUCE_FLS(sec
, count
);
3220 if (count_fls
+ sec_fls
> 64) {
3221 divisor
= nsec
* frequency
;
3223 while (count_fls
+ sec_fls
> 64) {
3224 REDUCE_FLS(count
, sec
);
3228 dividend
= count
* sec
;
3230 dividend
= count
* sec
;
3232 while (nsec_fls
+ frequency_fls
> 64) {
3233 REDUCE_FLS(nsec
, frequency
);
3237 divisor
= nsec
* frequency
;
3243 return div64_u64(dividend
, divisor
);
3246 static DEFINE_PER_CPU(int, perf_throttled_count
);
3247 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3249 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3251 struct hw_perf_event
*hwc
= &event
->hw
;
3252 s64 period
, sample_period
;
3255 period
= perf_calculate_period(event
, nsec
, count
);
3257 delta
= (s64
)(period
- hwc
->sample_period
);
3258 delta
= (delta
+ 7) / 8; /* low pass filter */
3260 sample_period
= hwc
->sample_period
+ delta
;
3265 hwc
->sample_period
= sample_period
;
3267 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3269 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3271 local64_set(&hwc
->period_left
, 0);
3274 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3279 * combine freq adjustment with unthrottling to avoid two passes over the
3280 * events. At the same time, make sure, having freq events does not change
3281 * the rate of unthrottling as that would introduce bias.
3283 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3286 struct perf_event
*event
;
3287 struct hw_perf_event
*hwc
;
3288 u64 now
, period
= TICK_NSEC
;
3292 * only need to iterate over all events iff:
3293 * - context have events in frequency mode (needs freq adjust)
3294 * - there are events to unthrottle on this cpu
3296 if (!(ctx
->nr_freq
|| needs_unthr
))
3299 raw_spin_lock(&ctx
->lock
);
3300 perf_pmu_disable(ctx
->pmu
);
3302 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3303 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3306 if (!event_filter_match(event
))
3309 perf_pmu_disable(event
->pmu
);
3313 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3314 hwc
->interrupts
= 0;
3315 perf_log_throttle(event
, 1);
3316 event
->pmu
->start(event
, 0);
3319 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3323 * stop the event and update event->count
3325 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3327 now
= local64_read(&event
->count
);
3328 delta
= now
- hwc
->freq_count_stamp
;
3329 hwc
->freq_count_stamp
= now
;
3333 * reload only if value has changed
3334 * we have stopped the event so tell that
3335 * to perf_adjust_period() to avoid stopping it
3339 perf_adjust_period(event
, period
, delta
, false);
3341 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3343 perf_pmu_enable(event
->pmu
);
3346 perf_pmu_enable(ctx
->pmu
);
3347 raw_spin_unlock(&ctx
->lock
);
3351 * Round-robin a context's events:
3353 static void rotate_ctx(struct perf_event_context
*ctx
)
3356 * Rotate the first entry last of non-pinned groups. Rotation might be
3357 * disabled by the inheritance code.
3359 if (!ctx
->rotate_disable
)
3360 list_rotate_left(&ctx
->flexible_groups
);
3363 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3365 struct perf_event_context
*ctx
= NULL
;
3368 if (cpuctx
->ctx
.nr_events
) {
3369 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3373 ctx
= cpuctx
->task_ctx
;
3374 if (ctx
&& ctx
->nr_events
) {
3375 if (ctx
->nr_events
!= ctx
->nr_active
)
3382 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3383 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3385 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3387 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3389 rotate_ctx(&cpuctx
->ctx
);
3393 perf_event_sched_in(cpuctx
, ctx
, current
);
3395 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3396 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3402 void perf_event_task_tick(void)
3404 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3405 struct perf_event_context
*ctx
, *tmp
;
3408 lockdep_assert_irqs_disabled();
3410 __this_cpu_inc(perf_throttled_seq
);
3411 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3412 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3414 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3415 perf_adjust_freq_unthr_context(ctx
, throttled
);
3418 static int event_enable_on_exec(struct perf_event
*event
,
3419 struct perf_event_context
*ctx
)
3421 if (!event
->attr
.enable_on_exec
)
3424 event
->attr
.enable_on_exec
= 0;
3425 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3428 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3434 * Enable all of a task's events that have been marked enable-on-exec.
3435 * This expects task == current.
3437 static void perf_event_enable_on_exec(int ctxn
)
3439 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3440 enum event_type_t event_type
= 0;
3441 struct perf_cpu_context
*cpuctx
;
3442 struct perf_event
*event
;
3443 unsigned long flags
;
3446 local_irq_save(flags
);
3447 ctx
= current
->perf_event_ctxp
[ctxn
];
3448 if (!ctx
|| !ctx
->nr_events
)
3451 cpuctx
= __get_cpu_context(ctx
);
3452 perf_ctx_lock(cpuctx
, ctx
);
3453 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3454 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3455 enabled
|= event_enable_on_exec(event
, ctx
);
3456 event_type
|= get_event_type(event
);
3460 * Unclone and reschedule this context if we enabled any event.
3463 clone_ctx
= unclone_ctx(ctx
);
3464 ctx_resched(cpuctx
, ctx
, event_type
);
3466 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3468 perf_ctx_unlock(cpuctx
, ctx
);
3471 local_irq_restore(flags
);
3477 struct perf_read_data
{
3478 struct perf_event
*event
;
3483 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3485 u16 local_pkg
, event_pkg
;
3487 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3488 int local_cpu
= smp_processor_id();
3490 event_pkg
= topology_physical_package_id(event_cpu
);
3491 local_pkg
= topology_physical_package_id(local_cpu
);
3493 if (event_pkg
== local_pkg
)
3501 * Cross CPU call to read the hardware event
3503 static void __perf_event_read(void *info
)
3505 struct perf_read_data
*data
= info
;
3506 struct perf_event
*sub
, *event
= data
->event
;
3507 struct perf_event_context
*ctx
= event
->ctx
;
3508 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3509 struct pmu
*pmu
= event
->pmu
;
3512 * If this is a task context, we need to check whether it is
3513 * the current task context of this cpu. If not it has been
3514 * scheduled out before the smp call arrived. In that case
3515 * event->count would have been updated to a recent sample
3516 * when the event was scheduled out.
3518 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3521 raw_spin_lock(&ctx
->lock
);
3522 if (ctx
->is_active
& EVENT_TIME
) {
3523 update_context_time(ctx
);
3524 update_cgrp_time_from_event(event
);
3527 perf_event_update_time(event
);
3529 perf_event_update_sibling_time(event
);
3531 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3540 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3544 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3545 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3547 * Use sibling's PMU rather than @event's since
3548 * sibling could be on different (eg: software) PMU.
3550 sub
->pmu
->read(sub
);
3554 data
->ret
= pmu
->commit_txn(pmu
);
3557 raw_spin_unlock(&ctx
->lock
);
3560 static inline u64
perf_event_count(struct perf_event
*event
)
3562 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3566 * NMI-safe method to read a local event, that is an event that
3568 * - either for the current task, or for this CPU
3569 * - does not have inherit set, for inherited task events
3570 * will not be local and we cannot read them atomically
3571 * - must not have a pmu::count method
3573 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
3574 u64
*enabled
, u64
*running
)
3576 unsigned long flags
;
3580 * Disabling interrupts avoids all counter scheduling (context
3581 * switches, timer based rotation and IPIs).
3583 local_irq_save(flags
);
3586 * It must not be an event with inherit set, we cannot read
3587 * all child counters from atomic context.
3589 if (event
->attr
.inherit
) {
3594 /* If this is a per-task event, it must be for current */
3595 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3596 event
->hw
.target
!= current
) {
3601 /* If this is a per-CPU event, it must be for this CPU */
3602 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3603 event
->cpu
!= smp_processor_id()) {
3609 * If the event is currently on this CPU, its either a per-task event,
3610 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3613 if (event
->oncpu
== smp_processor_id())
3614 event
->pmu
->read(event
);
3616 *value
= local64_read(&event
->count
);
3617 if (enabled
|| running
) {
3618 u64 now
= event
->shadow_ctx_time
+ perf_clock();
3619 u64 __enabled
, __running
;
3621 __perf_update_times(event
, now
, &__enabled
, &__running
);
3623 *enabled
= __enabled
;
3625 *running
= __running
;
3628 local_irq_restore(flags
);
3633 static int perf_event_read(struct perf_event
*event
, bool group
)
3635 enum perf_event_state state
= READ_ONCE(event
->state
);
3636 int event_cpu
, ret
= 0;
3639 * If event is enabled and currently active on a CPU, update the
3640 * value in the event structure:
3643 if (state
== PERF_EVENT_STATE_ACTIVE
) {
3644 struct perf_read_data data
;
3647 * Orders the ->state and ->oncpu loads such that if we see
3648 * ACTIVE we must also see the right ->oncpu.
3650 * Matches the smp_wmb() from event_sched_in().
3654 event_cpu
= READ_ONCE(event
->oncpu
);
3655 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3658 data
= (struct perf_read_data
){
3665 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3668 * Purposely ignore the smp_call_function_single() return
3671 * If event_cpu isn't a valid CPU it means the event got
3672 * scheduled out and that will have updated the event count.
3674 * Therefore, either way, we'll have an up-to-date event count
3677 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3681 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
3682 struct perf_event_context
*ctx
= event
->ctx
;
3683 unsigned long flags
;
3685 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3686 state
= event
->state
;
3687 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
3688 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3693 * May read while context is not active (e.g., thread is
3694 * blocked), in that case we cannot update context time
3696 if (ctx
->is_active
& EVENT_TIME
) {
3697 update_context_time(ctx
);
3698 update_cgrp_time_from_event(event
);
3701 perf_event_update_time(event
);
3703 perf_event_update_sibling_time(event
);
3704 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3711 * Initialize the perf_event context in a task_struct:
3713 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3715 raw_spin_lock_init(&ctx
->lock
);
3716 mutex_init(&ctx
->mutex
);
3717 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3718 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3719 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3720 INIT_LIST_HEAD(&ctx
->event_list
);
3721 atomic_set(&ctx
->refcount
, 1);
3724 static struct perf_event_context
*
3725 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3727 struct perf_event_context
*ctx
;
3729 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3733 __perf_event_init_context(ctx
);
3736 get_task_struct(task
);
3743 static struct task_struct
*
3744 find_lively_task_by_vpid(pid_t vpid
)
3746 struct task_struct
*task
;
3752 task
= find_task_by_vpid(vpid
);
3754 get_task_struct(task
);
3758 return ERR_PTR(-ESRCH
);
3764 * Returns a matching context with refcount and pincount.
3766 static struct perf_event_context
*
3767 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3768 struct perf_event
*event
)
3770 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3771 struct perf_cpu_context
*cpuctx
;
3772 void *task_ctx_data
= NULL
;
3773 unsigned long flags
;
3775 int cpu
= event
->cpu
;
3778 /* Must be root to operate on a CPU event: */
3779 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3780 return ERR_PTR(-EACCES
);
3782 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3791 ctxn
= pmu
->task_ctx_nr
;
3795 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3796 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3797 if (!task_ctx_data
) {
3804 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3806 clone_ctx
= unclone_ctx(ctx
);
3809 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3810 ctx
->task_ctx_data
= task_ctx_data
;
3811 task_ctx_data
= NULL
;
3813 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3818 ctx
= alloc_perf_context(pmu
, task
);
3823 if (task_ctx_data
) {
3824 ctx
->task_ctx_data
= task_ctx_data
;
3825 task_ctx_data
= NULL
;
3829 mutex_lock(&task
->perf_event_mutex
);
3831 * If it has already passed perf_event_exit_task().
3832 * we must see PF_EXITING, it takes this mutex too.
3834 if (task
->flags
& PF_EXITING
)
3836 else if (task
->perf_event_ctxp
[ctxn
])
3841 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3843 mutex_unlock(&task
->perf_event_mutex
);
3845 if (unlikely(err
)) {
3854 kfree(task_ctx_data
);
3858 kfree(task_ctx_data
);
3859 return ERR_PTR(err
);
3862 static void perf_event_free_filter(struct perf_event
*event
);
3863 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3865 static void free_event_rcu(struct rcu_head
*head
)
3867 struct perf_event
*event
;
3869 event
= container_of(head
, struct perf_event
, rcu_head
);
3871 put_pid_ns(event
->ns
);
3872 perf_event_free_filter(event
);
3876 static void ring_buffer_attach(struct perf_event
*event
,
3877 struct ring_buffer
*rb
);
3879 static void detach_sb_event(struct perf_event
*event
)
3881 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3883 raw_spin_lock(&pel
->lock
);
3884 list_del_rcu(&event
->sb_list
);
3885 raw_spin_unlock(&pel
->lock
);
3888 static bool is_sb_event(struct perf_event
*event
)
3890 struct perf_event_attr
*attr
= &event
->attr
;
3895 if (event
->attach_state
& PERF_ATTACH_TASK
)
3898 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3899 attr
->comm
|| attr
->comm_exec
||
3901 attr
->context_switch
)
3906 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3908 if (is_sb_event(event
))
3909 detach_sb_event(event
);
3912 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3917 if (is_cgroup_event(event
))
3918 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3921 #ifdef CONFIG_NO_HZ_FULL
3922 static DEFINE_SPINLOCK(nr_freq_lock
);
3925 static void unaccount_freq_event_nohz(void)
3927 #ifdef CONFIG_NO_HZ_FULL
3928 spin_lock(&nr_freq_lock
);
3929 if (atomic_dec_and_test(&nr_freq_events
))
3930 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3931 spin_unlock(&nr_freq_lock
);
3935 static void unaccount_freq_event(void)
3937 if (tick_nohz_full_enabled())
3938 unaccount_freq_event_nohz();
3940 atomic_dec(&nr_freq_events
);
3943 static void unaccount_event(struct perf_event
*event
)
3950 if (event
->attach_state
& PERF_ATTACH_TASK
)
3952 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3953 atomic_dec(&nr_mmap_events
);
3954 if (event
->attr
.comm
)
3955 atomic_dec(&nr_comm_events
);
3956 if (event
->attr
.namespaces
)
3957 atomic_dec(&nr_namespaces_events
);
3958 if (event
->attr
.task
)
3959 atomic_dec(&nr_task_events
);
3960 if (event
->attr
.freq
)
3961 unaccount_freq_event();
3962 if (event
->attr
.context_switch
) {
3964 atomic_dec(&nr_switch_events
);
3966 if (is_cgroup_event(event
))
3968 if (has_branch_stack(event
))
3972 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3973 schedule_delayed_work(&perf_sched_work
, HZ
);
3976 unaccount_event_cpu(event
, event
->cpu
);
3978 unaccount_pmu_sb_event(event
);
3981 static void perf_sched_delayed(struct work_struct
*work
)
3983 mutex_lock(&perf_sched_mutex
);
3984 if (atomic_dec_and_test(&perf_sched_count
))
3985 static_branch_disable(&perf_sched_events
);
3986 mutex_unlock(&perf_sched_mutex
);
3990 * The following implement mutual exclusion of events on "exclusive" pmus
3991 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3992 * at a time, so we disallow creating events that might conflict, namely:
3994 * 1) cpu-wide events in the presence of per-task events,
3995 * 2) per-task events in the presence of cpu-wide events,
3996 * 3) two matching events on the same context.
3998 * The former two cases are handled in the allocation path (perf_event_alloc(),
3999 * _free_event()), the latter -- before the first perf_install_in_context().
4001 static int exclusive_event_init(struct perf_event
*event
)
4003 struct pmu
*pmu
= event
->pmu
;
4005 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4009 * Prevent co-existence of per-task and cpu-wide events on the
4010 * same exclusive pmu.
4012 * Negative pmu::exclusive_cnt means there are cpu-wide
4013 * events on this "exclusive" pmu, positive means there are
4016 * Since this is called in perf_event_alloc() path, event::ctx
4017 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4018 * to mean "per-task event", because unlike other attach states it
4019 * never gets cleared.
4021 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4022 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4025 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4032 static void exclusive_event_destroy(struct perf_event
*event
)
4034 struct pmu
*pmu
= event
->pmu
;
4036 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4039 /* see comment in exclusive_event_init() */
4040 if (event
->attach_state
& PERF_ATTACH_TASK
)
4041 atomic_dec(&pmu
->exclusive_cnt
);
4043 atomic_inc(&pmu
->exclusive_cnt
);
4046 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4048 if ((e1
->pmu
== e2
->pmu
) &&
4049 (e1
->cpu
== e2
->cpu
||
4056 /* Called under the same ctx::mutex as perf_install_in_context() */
4057 static bool exclusive_event_installable(struct perf_event
*event
,
4058 struct perf_event_context
*ctx
)
4060 struct perf_event
*iter_event
;
4061 struct pmu
*pmu
= event
->pmu
;
4063 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4066 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4067 if (exclusive_event_match(iter_event
, event
))
4074 static void perf_addr_filters_splice(struct perf_event
*event
,
4075 struct list_head
*head
);
4077 static void _free_event(struct perf_event
*event
)
4079 irq_work_sync(&event
->pending
);
4081 unaccount_event(event
);
4085 * Can happen when we close an event with re-directed output.
4087 * Since we have a 0 refcount, perf_mmap_close() will skip
4088 * over us; possibly making our ring_buffer_put() the last.
4090 mutex_lock(&event
->mmap_mutex
);
4091 ring_buffer_attach(event
, NULL
);
4092 mutex_unlock(&event
->mmap_mutex
);
4095 if (is_cgroup_event(event
))
4096 perf_detach_cgroup(event
);
4098 if (!event
->parent
) {
4099 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4100 put_callchain_buffers();
4103 perf_event_free_bpf_prog(event
);
4104 perf_addr_filters_splice(event
, NULL
);
4105 kfree(event
->addr_filters_offs
);
4108 event
->destroy(event
);
4111 put_ctx(event
->ctx
);
4113 exclusive_event_destroy(event
);
4114 module_put(event
->pmu
->module
);
4116 call_rcu(&event
->rcu_head
, free_event_rcu
);
4120 * Used to free events which have a known refcount of 1, such as in error paths
4121 * where the event isn't exposed yet and inherited events.
4123 static void free_event(struct perf_event
*event
)
4125 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4126 "unexpected event refcount: %ld; ptr=%p\n",
4127 atomic_long_read(&event
->refcount
), event
)) {
4128 /* leak to avoid use-after-free */
4136 * Remove user event from the owner task.
4138 static void perf_remove_from_owner(struct perf_event
*event
)
4140 struct task_struct
*owner
;
4144 * Matches the smp_store_release() in perf_event_exit_task(). If we
4145 * observe !owner it means the list deletion is complete and we can
4146 * indeed free this event, otherwise we need to serialize on
4147 * owner->perf_event_mutex.
4149 owner
= READ_ONCE(event
->owner
);
4152 * Since delayed_put_task_struct() also drops the last
4153 * task reference we can safely take a new reference
4154 * while holding the rcu_read_lock().
4156 get_task_struct(owner
);
4162 * If we're here through perf_event_exit_task() we're already
4163 * holding ctx->mutex which would be an inversion wrt. the
4164 * normal lock order.
4166 * However we can safely take this lock because its the child
4169 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4172 * We have to re-check the event->owner field, if it is cleared
4173 * we raced with perf_event_exit_task(), acquiring the mutex
4174 * ensured they're done, and we can proceed with freeing the
4178 list_del_init(&event
->owner_entry
);
4179 smp_store_release(&event
->owner
, NULL
);
4181 mutex_unlock(&owner
->perf_event_mutex
);
4182 put_task_struct(owner
);
4186 static void put_event(struct perf_event
*event
)
4188 if (!atomic_long_dec_and_test(&event
->refcount
))
4195 * Kill an event dead; while event:refcount will preserve the event
4196 * object, it will not preserve its functionality. Once the last 'user'
4197 * gives up the object, we'll destroy the thing.
4199 int perf_event_release_kernel(struct perf_event
*event
)
4201 struct perf_event_context
*ctx
= event
->ctx
;
4202 struct perf_event
*child
, *tmp
;
4203 LIST_HEAD(free_list
);
4206 * If we got here through err_file: fput(event_file); we will not have
4207 * attached to a context yet.
4210 WARN_ON_ONCE(event
->attach_state
&
4211 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4215 if (!is_kernel_event(event
))
4216 perf_remove_from_owner(event
);
4218 ctx
= perf_event_ctx_lock(event
);
4219 WARN_ON_ONCE(ctx
->parent_ctx
);
4220 perf_remove_from_context(event
, DETACH_GROUP
);
4222 raw_spin_lock_irq(&ctx
->lock
);
4224 * Mark this event as STATE_DEAD, there is no external reference to it
4227 * Anybody acquiring event->child_mutex after the below loop _must_
4228 * also see this, most importantly inherit_event() which will avoid
4229 * placing more children on the list.
4231 * Thus this guarantees that we will in fact observe and kill _ALL_
4234 event
->state
= PERF_EVENT_STATE_DEAD
;
4235 raw_spin_unlock_irq(&ctx
->lock
);
4237 perf_event_ctx_unlock(event
, ctx
);
4240 mutex_lock(&event
->child_mutex
);
4241 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4244 * Cannot change, child events are not migrated, see the
4245 * comment with perf_event_ctx_lock_nested().
4247 ctx
= READ_ONCE(child
->ctx
);
4249 * Since child_mutex nests inside ctx::mutex, we must jump
4250 * through hoops. We start by grabbing a reference on the ctx.
4252 * Since the event cannot get freed while we hold the
4253 * child_mutex, the context must also exist and have a !0
4259 * Now that we have a ctx ref, we can drop child_mutex, and
4260 * acquire ctx::mutex without fear of it going away. Then we
4261 * can re-acquire child_mutex.
4263 mutex_unlock(&event
->child_mutex
);
4264 mutex_lock(&ctx
->mutex
);
4265 mutex_lock(&event
->child_mutex
);
4268 * Now that we hold ctx::mutex and child_mutex, revalidate our
4269 * state, if child is still the first entry, it didn't get freed
4270 * and we can continue doing so.
4272 tmp
= list_first_entry_or_null(&event
->child_list
,
4273 struct perf_event
, child_list
);
4275 perf_remove_from_context(child
, DETACH_GROUP
);
4276 list_move(&child
->child_list
, &free_list
);
4278 * This matches the refcount bump in inherit_event();
4279 * this can't be the last reference.
4284 mutex_unlock(&event
->child_mutex
);
4285 mutex_unlock(&ctx
->mutex
);
4289 mutex_unlock(&event
->child_mutex
);
4291 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4292 list_del(&child
->child_list
);
4297 put_event(event
); /* Must be the 'last' reference */
4300 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4303 * Called when the last reference to the file is gone.
4305 static int perf_release(struct inode
*inode
, struct file
*file
)
4307 perf_event_release_kernel(file
->private_data
);
4311 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4313 struct perf_event
*child
;
4319 mutex_lock(&event
->child_mutex
);
4321 (void)perf_event_read(event
, false);
4322 total
+= perf_event_count(event
);
4324 *enabled
+= event
->total_time_enabled
+
4325 atomic64_read(&event
->child_total_time_enabled
);
4326 *running
+= event
->total_time_running
+
4327 atomic64_read(&event
->child_total_time_running
);
4329 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4330 (void)perf_event_read(child
, false);
4331 total
+= perf_event_count(child
);
4332 *enabled
+= child
->total_time_enabled
;
4333 *running
+= child
->total_time_running
;
4335 mutex_unlock(&event
->child_mutex
);
4340 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4342 struct perf_event_context
*ctx
;
4345 ctx
= perf_event_ctx_lock(event
);
4346 count
= __perf_event_read_value(event
, enabled
, running
);
4347 perf_event_ctx_unlock(event
, ctx
);
4351 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4353 static int __perf_read_group_add(struct perf_event
*leader
,
4354 u64 read_format
, u64
*values
)
4356 struct perf_event_context
*ctx
= leader
->ctx
;
4357 struct perf_event
*sub
;
4358 unsigned long flags
;
4359 int n
= 1; /* skip @nr */
4362 ret
= perf_event_read(leader
, true);
4366 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4369 * Since we co-schedule groups, {enabled,running} times of siblings
4370 * will be identical to those of the leader, so we only publish one
4373 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4374 values
[n
++] += leader
->total_time_enabled
+
4375 atomic64_read(&leader
->child_total_time_enabled
);
4378 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4379 values
[n
++] += leader
->total_time_running
+
4380 atomic64_read(&leader
->child_total_time_running
);
4384 * Write {count,id} tuples for every sibling.
4386 values
[n
++] += perf_event_count(leader
);
4387 if (read_format
& PERF_FORMAT_ID
)
4388 values
[n
++] = primary_event_id(leader
);
4390 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4391 values
[n
++] += perf_event_count(sub
);
4392 if (read_format
& PERF_FORMAT_ID
)
4393 values
[n
++] = primary_event_id(sub
);
4396 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4400 static int perf_read_group(struct perf_event
*event
,
4401 u64 read_format
, char __user
*buf
)
4403 struct perf_event
*leader
= event
->group_leader
, *child
;
4404 struct perf_event_context
*ctx
= leader
->ctx
;
4408 lockdep_assert_held(&ctx
->mutex
);
4410 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4414 values
[0] = 1 + leader
->nr_siblings
;
4417 * By locking the child_mutex of the leader we effectively
4418 * lock the child list of all siblings.. XXX explain how.
4420 mutex_lock(&leader
->child_mutex
);
4422 ret
= __perf_read_group_add(leader
, read_format
, values
);
4426 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4427 ret
= __perf_read_group_add(child
, read_format
, values
);
4432 mutex_unlock(&leader
->child_mutex
);
4434 ret
= event
->read_size
;
4435 if (copy_to_user(buf
, values
, event
->read_size
))
4440 mutex_unlock(&leader
->child_mutex
);
4446 static int perf_read_one(struct perf_event
*event
,
4447 u64 read_format
, char __user
*buf
)
4449 u64 enabled
, running
;
4453 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4454 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4455 values
[n
++] = enabled
;
4456 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4457 values
[n
++] = running
;
4458 if (read_format
& PERF_FORMAT_ID
)
4459 values
[n
++] = primary_event_id(event
);
4461 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4464 return n
* sizeof(u64
);
4467 static bool is_event_hup(struct perf_event
*event
)
4471 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4474 mutex_lock(&event
->child_mutex
);
4475 no_children
= list_empty(&event
->child_list
);
4476 mutex_unlock(&event
->child_mutex
);
4481 * Read the performance event - simple non blocking version for now
4484 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4486 u64 read_format
= event
->attr
.read_format
;
4490 * Return end-of-file for a read on a event that is in
4491 * error state (i.e. because it was pinned but it couldn't be
4492 * scheduled on to the CPU at some point).
4494 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4497 if (count
< event
->read_size
)
4500 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4501 if (read_format
& PERF_FORMAT_GROUP
)
4502 ret
= perf_read_group(event
, read_format
, buf
);
4504 ret
= perf_read_one(event
, read_format
, buf
);
4510 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4512 struct perf_event
*event
= file
->private_data
;
4513 struct perf_event_context
*ctx
;
4516 ctx
= perf_event_ctx_lock(event
);
4517 ret
= __perf_read(event
, buf
, count
);
4518 perf_event_ctx_unlock(event
, ctx
);
4523 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4525 struct perf_event
*event
= file
->private_data
;
4526 struct ring_buffer
*rb
;
4527 unsigned int events
= POLLHUP
;
4529 poll_wait(file
, &event
->waitq
, wait
);
4531 if (is_event_hup(event
))
4535 * Pin the event->rb by taking event->mmap_mutex; otherwise
4536 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4538 mutex_lock(&event
->mmap_mutex
);
4541 events
= atomic_xchg(&rb
->poll
, 0);
4542 mutex_unlock(&event
->mmap_mutex
);
4546 static void _perf_event_reset(struct perf_event
*event
)
4548 (void)perf_event_read(event
, false);
4549 local64_set(&event
->count
, 0);
4550 perf_event_update_userpage(event
);
4554 * Holding the top-level event's child_mutex means that any
4555 * descendant process that has inherited this event will block
4556 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4557 * task existence requirements of perf_event_enable/disable.
4559 static void perf_event_for_each_child(struct perf_event
*event
,
4560 void (*func
)(struct perf_event
*))
4562 struct perf_event
*child
;
4564 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4566 mutex_lock(&event
->child_mutex
);
4568 list_for_each_entry(child
, &event
->child_list
, child_list
)
4570 mutex_unlock(&event
->child_mutex
);
4573 static void perf_event_for_each(struct perf_event
*event
,
4574 void (*func
)(struct perf_event
*))
4576 struct perf_event_context
*ctx
= event
->ctx
;
4577 struct perf_event
*sibling
;
4579 lockdep_assert_held(&ctx
->mutex
);
4581 event
= event
->group_leader
;
4583 perf_event_for_each_child(event
, func
);
4584 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4585 perf_event_for_each_child(sibling
, func
);
4588 static void __perf_event_period(struct perf_event
*event
,
4589 struct perf_cpu_context
*cpuctx
,
4590 struct perf_event_context
*ctx
,
4593 u64 value
= *((u64
*)info
);
4596 if (event
->attr
.freq
) {
4597 event
->attr
.sample_freq
= value
;
4599 event
->attr
.sample_period
= value
;
4600 event
->hw
.sample_period
= value
;
4603 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4605 perf_pmu_disable(ctx
->pmu
);
4607 * We could be throttled; unthrottle now to avoid the tick
4608 * trying to unthrottle while we already re-started the event.
4610 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4611 event
->hw
.interrupts
= 0;
4612 perf_log_throttle(event
, 1);
4614 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4617 local64_set(&event
->hw
.period_left
, 0);
4620 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4621 perf_pmu_enable(ctx
->pmu
);
4625 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4629 if (!is_sampling_event(event
))
4632 if (copy_from_user(&value
, arg
, sizeof(value
)))
4638 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4641 event_function_call(event
, __perf_event_period
, &value
);
4646 static const struct file_operations perf_fops
;
4648 static inline int perf_fget_light(int fd
, struct fd
*p
)
4650 struct fd f
= fdget(fd
);
4654 if (f
.file
->f_op
!= &perf_fops
) {
4662 static int perf_event_set_output(struct perf_event
*event
,
4663 struct perf_event
*output_event
);
4664 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4665 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4667 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4669 void (*func
)(struct perf_event
*);
4673 case PERF_EVENT_IOC_ENABLE
:
4674 func
= _perf_event_enable
;
4676 case PERF_EVENT_IOC_DISABLE
:
4677 func
= _perf_event_disable
;
4679 case PERF_EVENT_IOC_RESET
:
4680 func
= _perf_event_reset
;
4683 case PERF_EVENT_IOC_REFRESH
:
4684 return _perf_event_refresh(event
, arg
);
4686 case PERF_EVENT_IOC_PERIOD
:
4687 return perf_event_period(event
, (u64 __user
*)arg
);
4689 case PERF_EVENT_IOC_ID
:
4691 u64 id
= primary_event_id(event
);
4693 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4698 case PERF_EVENT_IOC_SET_OUTPUT
:
4702 struct perf_event
*output_event
;
4704 ret
= perf_fget_light(arg
, &output
);
4707 output_event
= output
.file
->private_data
;
4708 ret
= perf_event_set_output(event
, output_event
);
4711 ret
= perf_event_set_output(event
, NULL
);
4716 case PERF_EVENT_IOC_SET_FILTER
:
4717 return perf_event_set_filter(event
, (void __user
*)arg
);
4719 case PERF_EVENT_IOC_SET_BPF
:
4720 return perf_event_set_bpf_prog(event
, arg
);
4722 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4723 struct ring_buffer
*rb
;
4726 rb
= rcu_dereference(event
->rb
);
4727 if (!rb
|| !rb
->nr_pages
) {
4731 rb_toggle_paused(rb
, !!arg
);
4739 if (flags
& PERF_IOC_FLAG_GROUP
)
4740 perf_event_for_each(event
, func
);
4742 perf_event_for_each_child(event
, func
);
4747 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4749 struct perf_event
*event
= file
->private_data
;
4750 struct perf_event_context
*ctx
;
4753 ctx
= perf_event_ctx_lock(event
);
4754 ret
= _perf_ioctl(event
, cmd
, arg
);
4755 perf_event_ctx_unlock(event
, ctx
);
4760 #ifdef CONFIG_COMPAT
4761 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4764 switch (_IOC_NR(cmd
)) {
4765 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4766 case _IOC_NR(PERF_EVENT_IOC_ID
):
4767 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4768 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4769 cmd
&= ~IOCSIZE_MASK
;
4770 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4774 return perf_ioctl(file
, cmd
, arg
);
4777 # define perf_compat_ioctl NULL
4780 int perf_event_task_enable(void)
4782 struct perf_event_context
*ctx
;
4783 struct perf_event
*event
;
4785 mutex_lock(¤t
->perf_event_mutex
);
4786 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4787 ctx
= perf_event_ctx_lock(event
);
4788 perf_event_for_each_child(event
, _perf_event_enable
);
4789 perf_event_ctx_unlock(event
, ctx
);
4791 mutex_unlock(¤t
->perf_event_mutex
);
4796 int perf_event_task_disable(void)
4798 struct perf_event_context
*ctx
;
4799 struct perf_event
*event
;
4801 mutex_lock(¤t
->perf_event_mutex
);
4802 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4803 ctx
= perf_event_ctx_lock(event
);
4804 perf_event_for_each_child(event
, _perf_event_disable
);
4805 perf_event_ctx_unlock(event
, ctx
);
4807 mutex_unlock(¤t
->perf_event_mutex
);
4812 static int perf_event_index(struct perf_event
*event
)
4814 if (event
->hw
.state
& PERF_HES_STOPPED
)
4817 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4820 return event
->pmu
->event_idx(event
);
4823 static void calc_timer_values(struct perf_event
*event
,
4830 *now
= perf_clock();
4831 ctx_time
= event
->shadow_ctx_time
+ *now
;
4832 __perf_update_times(event
, ctx_time
, enabled
, running
);
4835 static void perf_event_init_userpage(struct perf_event
*event
)
4837 struct perf_event_mmap_page
*userpg
;
4838 struct ring_buffer
*rb
;
4841 rb
= rcu_dereference(event
->rb
);
4845 userpg
= rb
->user_page
;
4847 /* Allow new userspace to detect that bit 0 is deprecated */
4848 userpg
->cap_bit0_is_deprecated
= 1;
4849 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4850 userpg
->data_offset
= PAGE_SIZE
;
4851 userpg
->data_size
= perf_data_size(rb
);
4857 void __weak
arch_perf_update_userpage(
4858 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4863 * Callers need to ensure there can be no nesting of this function, otherwise
4864 * the seqlock logic goes bad. We can not serialize this because the arch
4865 * code calls this from NMI context.
4867 void perf_event_update_userpage(struct perf_event
*event
)
4869 struct perf_event_mmap_page
*userpg
;
4870 struct ring_buffer
*rb
;
4871 u64 enabled
, running
, now
;
4874 rb
= rcu_dereference(event
->rb
);
4879 * compute total_time_enabled, total_time_running
4880 * based on snapshot values taken when the event
4881 * was last scheduled in.
4883 * we cannot simply called update_context_time()
4884 * because of locking issue as we can be called in
4887 calc_timer_values(event
, &now
, &enabled
, &running
);
4889 userpg
= rb
->user_page
;
4891 * Disable preemption so as to not let the corresponding user-space
4892 * spin too long if we get preempted.
4897 userpg
->index
= perf_event_index(event
);
4898 userpg
->offset
= perf_event_count(event
);
4900 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4902 userpg
->time_enabled
= enabled
+
4903 atomic64_read(&event
->child_total_time_enabled
);
4905 userpg
->time_running
= running
+
4906 atomic64_read(&event
->child_total_time_running
);
4908 arch_perf_update_userpage(event
, userpg
, now
);
4917 static int perf_mmap_fault(struct vm_fault
*vmf
)
4919 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4920 struct ring_buffer
*rb
;
4921 int ret
= VM_FAULT_SIGBUS
;
4923 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4924 if (vmf
->pgoff
== 0)
4930 rb
= rcu_dereference(event
->rb
);
4934 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4937 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4941 get_page(vmf
->page
);
4942 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4943 vmf
->page
->index
= vmf
->pgoff
;
4952 static void ring_buffer_attach(struct perf_event
*event
,
4953 struct ring_buffer
*rb
)
4955 struct ring_buffer
*old_rb
= NULL
;
4956 unsigned long flags
;
4960 * Should be impossible, we set this when removing
4961 * event->rb_entry and wait/clear when adding event->rb_entry.
4963 WARN_ON_ONCE(event
->rcu_pending
);
4966 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4967 list_del_rcu(&event
->rb_entry
);
4968 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4970 event
->rcu_batches
= get_state_synchronize_rcu();
4971 event
->rcu_pending
= 1;
4975 if (event
->rcu_pending
) {
4976 cond_synchronize_rcu(event
->rcu_batches
);
4977 event
->rcu_pending
= 0;
4980 spin_lock_irqsave(&rb
->event_lock
, flags
);
4981 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4982 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4986 * Avoid racing with perf_mmap_close(AUX): stop the event
4987 * before swizzling the event::rb pointer; if it's getting
4988 * unmapped, its aux_mmap_count will be 0 and it won't
4989 * restart. See the comment in __perf_pmu_output_stop().
4991 * Data will inevitably be lost when set_output is done in
4992 * mid-air, but then again, whoever does it like this is
4993 * not in for the data anyway.
4996 perf_event_stop(event
, 0);
4998 rcu_assign_pointer(event
->rb
, rb
);
5001 ring_buffer_put(old_rb
);
5003 * Since we detached before setting the new rb, so that we
5004 * could attach the new rb, we could have missed a wakeup.
5007 wake_up_all(&event
->waitq
);
5011 static void ring_buffer_wakeup(struct perf_event
*event
)
5013 struct ring_buffer
*rb
;
5016 rb
= rcu_dereference(event
->rb
);
5018 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5019 wake_up_all(&event
->waitq
);
5024 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5026 struct ring_buffer
*rb
;
5029 rb
= rcu_dereference(event
->rb
);
5031 if (!atomic_inc_not_zero(&rb
->refcount
))
5039 void ring_buffer_put(struct ring_buffer
*rb
)
5041 if (!atomic_dec_and_test(&rb
->refcount
))
5044 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5046 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5049 static void perf_mmap_open(struct vm_area_struct
*vma
)
5051 struct perf_event
*event
= vma
->vm_file
->private_data
;
5053 atomic_inc(&event
->mmap_count
);
5054 atomic_inc(&event
->rb
->mmap_count
);
5057 atomic_inc(&event
->rb
->aux_mmap_count
);
5059 if (event
->pmu
->event_mapped
)
5060 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5063 static void perf_pmu_output_stop(struct perf_event
*event
);
5066 * A buffer can be mmap()ed multiple times; either directly through the same
5067 * event, or through other events by use of perf_event_set_output().
5069 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5070 * the buffer here, where we still have a VM context. This means we need
5071 * to detach all events redirecting to us.
5073 static void perf_mmap_close(struct vm_area_struct
*vma
)
5075 struct perf_event
*event
= vma
->vm_file
->private_data
;
5077 struct ring_buffer
*rb
= ring_buffer_get(event
);
5078 struct user_struct
*mmap_user
= rb
->mmap_user
;
5079 int mmap_locked
= rb
->mmap_locked
;
5080 unsigned long size
= perf_data_size(rb
);
5082 if (event
->pmu
->event_unmapped
)
5083 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5086 * rb->aux_mmap_count will always drop before rb->mmap_count and
5087 * event->mmap_count, so it is ok to use event->mmap_mutex to
5088 * serialize with perf_mmap here.
5090 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5091 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5093 * Stop all AUX events that are writing to this buffer,
5094 * so that we can free its AUX pages and corresponding PMU
5095 * data. Note that after rb::aux_mmap_count dropped to zero,
5096 * they won't start any more (see perf_aux_output_begin()).
5098 perf_pmu_output_stop(event
);
5100 /* now it's safe to free the pages */
5101 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5102 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5104 /* this has to be the last one */
5106 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5108 mutex_unlock(&event
->mmap_mutex
);
5111 atomic_dec(&rb
->mmap_count
);
5113 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5116 ring_buffer_attach(event
, NULL
);
5117 mutex_unlock(&event
->mmap_mutex
);
5119 /* If there's still other mmap()s of this buffer, we're done. */
5120 if (atomic_read(&rb
->mmap_count
))
5124 * No other mmap()s, detach from all other events that might redirect
5125 * into the now unreachable buffer. Somewhat complicated by the
5126 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5130 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5131 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5133 * This event is en-route to free_event() which will
5134 * detach it and remove it from the list.
5140 mutex_lock(&event
->mmap_mutex
);
5142 * Check we didn't race with perf_event_set_output() which can
5143 * swizzle the rb from under us while we were waiting to
5144 * acquire mmap_mutex.
5146 * If we find a different rb; ignore this event, a next
5147 * iteration will no longer find it on the list. We have to
5148 * still restart the iteration to make sure we're not now
5149 * iterating the wrong list.
5151 if (event
->rb
== rb
)
5152 ring_buffer_attach(event
, NULL
);
5154 mutex_unlock(&event
->mmap_mutex
);
5158 * Restart the iteration; either we're on the wrong list or
5159 * destroyed its integrity by doing a deletion.
5166 * It could be there's still a few 0-ref events on the list; they'll
5167 * get cleaned up by free_event() -- they'll also still have their
5168 * ref on the rb and will free it whenever they are done with it.
5170 * Aside from that, this buffer is 'fully' detached and unmapped,
5171 * undo the VM accounting.
5174 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5175 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5176 free_uid(mmap_user
);
5179 ring_buffer_put(rb
); /* could be last */
5182 static const struct vm_operations_struct perf_mmap_vmops
= {
5183 .open
= perf_mmap_open
,
5184 .close
= perf_mmap_close
, /* non mergable */
5185 .fault
= perf_mmap_fault
,
5186 .page_mkwrite
= perf_mmap_fault
,
5189 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5191 struct perf_event
*event
= file
->private_data
;
5192 unsigned long user_locked
, user_lock_limit
;
5193 struct user_struct
*user
= current_user();
5194 unsigned long locked
, lock_limit
;
5195 struct ring_buffer
*rb
= NULL
;
5196 unsigned long vma_size
;
5197 unsigned long nr_pages
;
5198 long user_extra
= 0, extra
= 0;
5199 int ret
= 0, flags
= 0;
5202 * Don't allow mmap() of inherited per-task counters. This would
5203 * create a performance issue due to all children writing to the
5206 if (event
->cpu
== -1 && event
->attr
.inherit
)
5209 if (!(vma
->vm_flags
& VM_SHARED
))
5212 vma_size
= vma
->vm_end
- vma
->vm_start
;
5214 if (vma
->vm_pgoff
== 0) {
5215 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5218 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5219 * mapped, all subsequent mappings should have the same size
5220 * and offset. Must be above the normal perf buffer.
5222 u64 aux_offset
, aux_size
;
5227 nr_pages
= vma_size
/ PAGE_SIZE
;
5229 mutex_lock(&event
->mmap_mutex
);
5236 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5237 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5239 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5242 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5245 /* already mapped with a different offset */
5246 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5249 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5252 /* already mapped with a different size */
5253 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5256 if (!is_power_of_2(nr_pages
))
5259 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5262 if (rb_has_aux(rb
)) {
5263 atomic_inc(&rb
->aux_mmap_count
);
5268 atomic_set(&rb
->aux_mmap_count
, 1);
5269 user_extra
= nr_pages
;
5275 * If we have rb pages ensure they're a power-of-two number, so we
5276 * can do bitmasks instead of modulo.
5278 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5281 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5284 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5286 mutex_lock(&event
->mmap_mutex
);
5288 if (event
->rb
->nr_pages
!= nr_pages
) {
5293 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5295 * Raced against perf_mmap_close() through
5296 * perf_event_set_output(). Try again, hope for better
5299 mutex_unlock(&event
->mmap_mutex
);
5306 user_extra
= nr_pages
+ 1;
5309 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5312 * Increase the limit linearly with more CPUs:
5314 user_lock_limit
*= num_online_cpus();
5316 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5318 if (user_locked
> user_lock_limit
)
5319 extra
= user_locked
- user_lock_limit
;
5321 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5322 lock_limit
>>= PAGE_SHIFT
;
5323 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5325 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5326 !capable(CAP_IPC_LOCK
)) {
5331 WARN_ON(!rb
&& event
->rb
);
5333 if (vma
->vm_flags
& VM_WRITE
)
5334 flags
|= RING_BUFFER_WRITABLE
;
5337 rb
= rb_alloc(nr_pages
,
5338 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5346 atomic_set(&rb
->mmap_count
, 1);
5347 rb
->mmap_user
= get_current_user();
5348 rb
->mmap_locked
= extra
;
5350 ring_buffer_attach(event
, rb
);
5352 perf_event_init_userpage(event
);
5353 perf_event_update_userpage(event
);
5355 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5356 event
->attr
.aux_watermark
, flags
);
5358 rb
->aux_mmap_locked
= extra
;
5363 atomic_long_add(user_extra
, &user
->locked_vm
);
5364 vma
->vm_mm
->pinned_vm
+= extra
;
5366 atomic_inc(&event
->mmap_count
);
5368 atomic_dec(&rb
->mmap_count
);
5371 mutex_unlock(&event
->mmap_mutex
);
5374 * Since pinned accounting is per vm we cannot allow fork() to copy our
5377 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5378 vma
->vm_ops
= &perf_mmap_vmops
;
5380 if (event
->pmu
->event_mapped
)
5381 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5386 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5388 struct inode
*inode
= file_inode(filp
);
5389 struct perf_event
*event
= filp
->private_data
;
5393 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5394 inode_unlock(inode
);
5402 static const struct file_operations perf_fops
= {
5403 .llseek
= no_llseek
,
5404 .release
= perf_release
,
5407 .unlocked_ioctl
= perf_ioctl
,
5408 .compat_ioctl
= perf_compat_ioctl
,
5410 .fasync
= perf_fasync
,
5416 * If there's data, ensure we set the poll() state and publish everything
5417 * to user-space before waking everybody up.
5420 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5422 /* only the parent has fasync state */
5424 event
= event
->parent
;
5425 return &event
->fasync
;
5428 void perf_event_wakeup(struct perf_event
*event
)
5430 ring_buffer_wakeup(event
);
5432 if (event
->pending_kill
) {
5433 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5434 event
->pending_kill
= 0;
5438 static void perf_pending_event(struct irq_work
*entry
)
5440 struct perf_event
*event
= container_of(entry
,
5441 struct perf_event
, pending
);
5444 rctx
= perf_swevent_get_recursion_context();
5446 * If we 'fail' here, that's OK, it means recursion is already disabled
5447 * and we won't recurse 'further'.
5450 if (event
->pending_disable
) {
5451 event
->pending_disable
= 0;
5452 perf_event_disable_local(event
);
5455 if (event
->pending_wakeup
) {
5456 event
->pending_wakeup
= 0;
5457 perf_event_wakeup(event
);
5461 perf_swevent_put_recursion_context(rctx
);
5465 * We assume there is only KVM supporting the callbacks.
5466 * Later on, we might change it to a list if there is
5467 * another virtualization implementation supporting the callbacks.
5469 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5471 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5473 perf_guest_cbs
= cbs
;
5476 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5478 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5480 perf_guest_cbs
= NULL
;
5483 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5486 perf_output_sample_regs(struct perf_output_handle
*handle
,
5487 struct pt_regs
*regs
, u64 mask
)
5490 DECLARE_BITMAP(_mask
, 64);
5492 bitmap_from_u64(_mask
, mask
);
5493 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5496 val
= perf_reg_value(regs
, bit
);
5497 perf_output_put(handle
, val
);
5501 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5502 struct pt_regs
*regs
,
5503 struct pt_regs
*regs_user_copy
)
5505 if (user_mode(regs
)) {
5506 regs_user
->abi
= perf_reg_abi(current
);
5507 regs_user
->regs
= regs
;
5508 } else if (current
->mm
) {
5509 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5511 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5512 regs_user
->regs
= NULL
;
5516 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5517 struct pt_regs
*regs
)
5519 regs_intr
->regs
= regs
;
5520 regs_intr
->abi
= perf_reg_abi(current
);
5525 * Get remaining task size from user stack pointer.
5527 * It'd be better to take stack vma map and limit this more
5528 * precisly, but there's no way to get it safely under interrupt,
5529 * so using TASK_SIZE as limit.
5531 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5533 unsigned long addr
= perf_user_stack_pointer(regs
);
5535 if (!addr
|| addr
>= TASK_SIZE
)
5538 return TASK_SIZE
- addr
;
5542 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5543 struct pt_regs
*regs
)
5547 /* No regs, no stack pointer, no dump. */
5552 * Check if we fit in with the requested stack size into the:
5554 * If we don't, we limit the size to the TASK_SIZE.
5556 * - remaining sample size
5557 * If we don't, we customize the stack size to
5558 * fit in to the remaining sample size.
5561 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5562 stack_size
= min(stack_size
, (u16
) task_size
);
5564 /* Current header size plus static size and dynamic size. */
5565 header_size
+= 2 * sizeof(u64
);
5567 /* Do we fit in with the current stack dump size? */
5568 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5570 * If we overflow the maximum size for the sample,
5571 * we customize the stack dump size to fit in.
5573 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5574 stack_size
= round_up(stack_size
, sizeof(u64
));
5581 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5582 struct pt_regs
*regs
)
5584 /* Case of a kernel thread, nothing to dump */
5587 perf_output_put(handle
, size
);
5596 * - the size requested by user or the best one we can fit
5597 * in to the sample max size
5599 * - user stack dump data
5601 * - the actual dumped size
5605 perf_output_put(handle
, dump_size
);
5608 sp
= perf_user_stack_pointer(regs
);
5609 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5610 dyn_size
= dump_size
- rem
;
5612 perf_output_skip(handle
, rem
);
5615 perf_output_put(handle
, dyn_size
);
5619 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5620 struct perf_sample_data
*data
,
5621 struct perf_event
*event
)
5623 u64 sample_type
= event
->attr
.sample_type
;
5625 data
->type
= sample_type
;
5626 header
->size
+= event
->id_header_size
;
5628 if (sample_type
& PERF_SAMPLE_TID
) {
5629 /* namespace issues */
5630 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5631 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5634 if (sample_type
& PERF_SAMPLE_TIME
)
5635 data
->time
= perf_event_clock(event
);
5637 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5638 data
->id
= primary_event_id(event
);
5640 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5641 data
->stream_id
= event
->id
;
5643 if (sample_type
& PERF_SAMPLE_CPU
) {
5644 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5645 data
->cpu_entry
.reserved
= 0;
5649 void perf_event_header__init_id(struct perf_event_header
*header
,
5650 struct perf_sample_data
*data
,
5651 struct perf_event
*event
)
5653 if (event
->attr
.sample_id_all
)
5654 __perf_event_header__init_id(header
, data
, event
);
5657 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5658 struct perf_sample_data
*data
)
5660 u64 sample_type
= data
->type
;
5662 if (sample_type
& PERF_SAMPLE_TID
)
5663 perf_output_put(handle
, data
->tid_entry
);
5665 if (sample_type
& PERF_SAMPLE_TIME
)
5666 perf_output_put(handle
, data
->time
);
5668 if (sample_type
& PERF_SAMPLE_ID
)
5669 perf_output_put(handle
, data
->id
);
5671 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5672 perf_output_put(handle
, data
->stream_id
);
5674 if (sample_type
& PERF_SAMPLE_CPU
)
5675 perf_output_put(handle
, data
->cpu_entry
);
5677 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5678 perf_output_put(handle
, data
->id
);
5681 void perf_event__output_id_sample(struct perf_event
*event
,
5682 struct perf_output_handle
*handle
,
5683 struct perf_sample_data
*sample
)
5685 if (event
->attr
.sample_id_all
)
5686 __perf_event__output_id_sample(handle
, sample
);
5689 static void perf_output_read_one(struct perf_output_handle
*handle
,
5690 struct perf_event
*event
,
5691 u64 enabled
, u64 running
)
5693 u64 read_format
= event
->attr
.read_format
;
5697 values
[n
++] = perf_event_count(event
);
5698 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5699 values
[n
++] = enabled
+
5700 atomic64_read(&event
->child_total_time_enabled
);
5702 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5703 values
[n
++] = running
+
5704 atomic64_read(&event
->child_total_time_running
);
5706 if (read_format
& PERF_FORMAT_ID
)
5707 values
[n
++] = primary_event_id(event
);
5709 __output_copy(handle
, values
, n
* sizeof(u64
));
5712 static void perf_output_read_group(struct perf_output_handle
*handle
,
5713 struct perf_event
*event
,
5714 u64 enabled
, u64 running
)
5716 struct perf_event
*leader
= event
->group_leader
, *sub
;
5717 u64 read_format
= event
->attr
.read_format
;
5721 values
[n
++] = 1 + leader
->nr_siblings
;
5723 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5724 values
[n
++] = enabled
;
5726 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5727 values
[n
++] = running
;
5729 if (leader
!= event
)
5730 leader
->pmu
->read(leader
);
5732 values
[n
++] = perf_event_count(leader
);
5733 if (read_format
& PERF_FORMAT_ID
)
5734 values
[n
++] = primary_event_id(leader
);
5736 __output_copy(handle
, values
, n
* sizeof(u64
));
5738 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5741 if ((sub
!= event
) &&
5742 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5743 sub
->pmu
->read(sub
);
5745 values
[n
++] = perf_event_count(sub
);
5746 if (read_format
& PERF_FORMAT_ID
)
5747 values
[n
++] = primary_event_id(sub
);
5749 __output_copy(handle
, values
, n
* sizeof(u64
));
5753 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5754 PERF_FORMAT_TOTAL_TIME_RUNNING)
5757 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5759 * The problem is that its both hard and excessively expensive to iterate the
5760 * child list, not to mention that its impossible to IPI the children running
5761 * on another CPU, from interrupt/NMI context.
5763 static void perf_output_read(struct perf_output_handle
*handle
,
5764 struct perf_event
*event
)
5766 u64 enabled
= 0, running
= 0, now
;
5767 u64 read_format
= event
->attr
.read_format
;
5770 * compute total_time_enabled, total_time_running
5771 * based on snapshot values taken when the event
5772 * was last scheduled in.
5774 * we cannot simply called update_context_time()
5775 * because of locking issue as we are called in
5778 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5779 calc_timer_values(event
, &now
, &enabled
, &running
);
5781 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5782 perf_output_read_group(handle
, event
, enabled
, running
);
5784 perf_output_read_one(handle
, event
, enabled
, running
);
5787 void perf_output_sample(struct perf_output_handle
*handle
,
5788 struct perf_event_header
*header
,
5789 struct perf_sample_data
*data
,
5790 struct perf_event
*event
)
5792 u64 sample_type
= data
->type
;
5794 perf_output_put(handle
, *header
);
5796 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5797 perf_output_put(handle
, data
->id
);
5799 if (sample_type
& PERF_SAMPLE_IP
)
5800 perf_output_put(handle
, data
->ip
);
5802 if (sample_type
& PERF_SAMPLE_TID
)
5803 perf_output_put(handle
, data
->tid_entry
);
5805 if (sample_type
& PERF_SAMPLE_TIME
)
5806 perf_output_put(handle
, data
->time
);
5808 if (sample_type
& PERF_SAMPLE_ADDR
)
5809 perf_output_put(handle
, data
->addr
);
5811 if (sample_type
& PERF_SAMPLE_ID
)
5812 perf_output_put(handle
, data
->id
);
5814 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5815 perf_output_put(handle
, data
->stream_id
);
5817 if (sample_type
& PERF_SAMPLE_CPU
)
5818 perf_output_put(handle
, data
->cpu_entry
);
5820 if (sample_type
& PERF_SAMPLE_PERIOD
)
5821 perf_output_put(handle
, data
->period
);
5823 if (sample_type
& PERF_SAMPLE_READ
)
5824 perf_output_read(handle
, event
);
5826 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5827 if (data
->callchain
) {
5830 if (data
->callchain
)
5831 size
+= data
->callchain
->nr
;
5833 size
*= sizeof(u64
);
5835 __output_copy(handle
, data
->callchain
, size
);
5838 perf_output_put(handle
, nr
);
5842 if (sample_type
& PERF_SAMPLE_RAW
) {
5843 struct perf_raw_record
*raw
= data
->raw
;
5846 struct perf_raw_frag
*frag
= &raw
->frag
;
5848 perf_output_put(handle
, raw
->size
);
5851 __output_custom(handle
, frag
->copy
,
5852 frag
->data
, frag
->size
);
5854 __output_copy(handle
, frag
->data
,
5857 if (perf_raw_frag_last(frag
))
5862 __output_skip(handle
, NULL
, frag
->pad
);
5868 .size
= sizeof(u32
),
5871 perf_output_put(handle
, raw
);
5875 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5876 if (data
->br_stack
) {
5879 size
= data
->br_stack
->nr
5880 * sizeof(struct perf_branch_entry
);
5882 perf_output_put(handle
, data
->br_stack
->nr
);
5883 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5886 * we always store at least the value of nr
5889 perf_output_put(handle
, nr
);
5893 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5894 u64 abi
= data
->regs_user
.abi
;
5897 * If there are no regs to dump, notice it through
5898 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5900 perf_output_put(handle
, abi
);
5903 u64 mask
= event
->attr
.sample_regs_user
;
5904 perf_output_sample_regs(handle
,
5905 data
->regs_user
.regs
,
5910 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5911 perf_output_sample_ustack(handle
,
5912 data
->stack_user_size
,
5913 data
->regs_user
.regs
);
5916 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5917 perf_output_put(handle
, data
->weight
);
5919 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5920 perf_output_put(handle
, data
->data_src
.val
);
5922 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5923 perf_output_put(handle
, data
->txn
);
5925 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5926 u64 abi
= data
->regs_intr
.abi
;
5928 * If there are no regs to dump, notice it through
5929 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5931 perf_output_put(handle
, abi
);
5934 u64 mask
= event
->attr
.sample_regs_intr
;
5936 perf_output_sample_regs(handle
,
5937 data
->regs_intr
.regs
,
5942 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
5943 perf_output_put(handle
, data
->phys_addr
);
5945 if (!event
->attr
.watermark
) {
5946 int wakeup_events
= event
->attr
.wakeup_events
;
5948 if (wakeup_events
) {
5949 struct ring_buffer
*rb
= handle
->rb
;
5950 int events
= local_inc_return(&rb
->events
);
5952 if (events
>= wakeup_events
) {
5953 local_sub(wakeup_events
, &rb
->events
);
5954 local_inc(&rb
->wakeup
);
5960 static u64
perf_virt_to_phys(u64 virt
)
5963 struct page
*p
= NULL
;
5968 if (virt
>= TASK_SIZE
) {
5969 /* If it's vmalloc()d memory, leave phys_addr as 0 */
5970 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
5971 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
5972 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
5975 * Walking the pages tables for user address.
5976 * Interrupts are disabled, so it prevents any tear down
5977 * of the page tables.
5978 * Try IRQ-safe __get_user_pages_fast first.
5979 * If failed, leave phys_addr as 0.
5981 if ((current
->mm
!= NULL
) &&
5982 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
5983 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
5992 void perf_prepare_sample(struct perf_event_header
*header
,
5993 struct perf_sample_data
*data
,
5994 struct perf_event
*event
,
5995 struct pt_regs
*regs
)
5997 u64 sample_type
= event
->attr
.sample_type
;
5999 header
->type
= PERF_RECORD_SAMPLE
;
6000 header
->size
= sizeof(*header
) + event
->header_size
;
6003 header
->misc
|= perf_misc_flags(regs
);
6005 __perf_event_header__init_id(header
, data
, event
);
6007 if (sample_type
& PERF_SAMPLE_IP
)
6008 data
->ip
= perf_instruction_pointer(regs
);
6010 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6013 data
->callchain
= perf_callchain(event
, regs
);
6015 if (data
->callchain
)
6016 size
+= data
->callchain
->nr
;
6018 header
->size
+= size
* sizeof(u64
);
6021 if (sample_type
& PERF_SAMPLE_RAW
) {
6022 struct perf_raw_record
*raw
= data
->raw
;
6026 struct perf_raw_frag
*frag
= &raw
->frag
;
6031 if (perf_raw_frag_last(frag
))
6036 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6037 raw
->size
= size
- sizeof(u32
);
6038 frag
->pad
= raw
->size
- sum
;
6043 header
->size
+= size
;
6046 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6047 int size
= sizeof(u64
); /* nr */
6048 if (data
->br_stack
) {
6049 size
+= data
->br_stack
->nr
6050 * sizeof(struct perf_branch_entry
);
6052 header
->size
+= size
;
6055 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6056 perf_sample_regs_user(&data
->regs_user
, regs
,
6057 &data
->regs_user_copy
);
6059 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6060 /* regs dump ABI info */
6061 int size
= sizeof(u64
);
6063 if (data
->regs_user
.regs
) {
6064 u64 mask
= event
->attr
.sample_regs_user
;
6065 size
+= hweight64(mask
) * sizeof(u64
);
6068 header
->size
+= size
;
6071 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6073 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6074 * processed as the last one or have additional check added
6075 * in case new sample type is added, because we could eat
6076 * up the rest of the sample size.
6078 u16 stack_size
= event
->attr
.sample_stack_user
;
6079 u16 size
= sizeof(u64
);
6081 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6082 data
->regs_user
.regs
);
6085 * If there is something to dump, add space for the dump
6086 * itself and for the field that tells the dynamic size,
6087 * which is how many have been actually dumped.
6090 size
+= sizeof(u64
) + stack_size
;
6092 data
->stack_user_size
= stack_size
;
6093 header
->size
+= size
;
6096 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6097 /* regs dump ABI info */
6098 int size
= sizeof(u64
);
6100 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6102 if (data
->regs_intr
.regs
) {
6103 u64 mask
= event
->attr
.sample_regs_intr
;
6105 size
+= hweight64(mask
) * sizeof(u64
);
6108 header
->size
+= size
;
6111 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6112 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6115 static void __always_inline
6116 __perf_event_output(struct perf_event
*event
,
6117 struct perf_sample_data
*data
,
6118 struct pt_regs
*regs
,
6119 int (*output_begin
)(struct perf_output_handle
*,
6120 struct perf_event
*,
6123 struct perf_output_handle handle
;
6124 struct perf_event_header header
;
6126 /* protect the callchain buffers */
6129 perf_prepare_sample(&header
, data
, event
, regs
);
6131 if (output_begin(&handle
, event
, header
.size
))
6134 perf_output_sample(&handle
, &header
, data
, event
);
6136 perf_output_end(&handle
);
6143 perf_event_output_forward(struct perf_event
*event
,
6144 struct perf_sample_data
*data
,
6145 struct pt_regs
*regs
)
6147 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6151 perf_event_output_backward(struct perf_event
*event
,
6152 struct perf_sample_data
*data
,
6153 struct pt_regs
*regs
)
6155 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6159 perf_event_output(struct perf_event
*event
,
6160 struct perf_sample_data
*data
,
6161 struct pt_regs
*regs
)
6163 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6170 struct perf_read_event
{
6171 struct perf_event_header header
;
6178 perf_event_read_event(struct perf_event
*event
,
6179 struct task_struct
*task
)
6181 struct perf_output_handle handle
;
6182 struct perf_sample_data sample
;
6183 struct perf_read_event read_event
= {
6185 .type
= PERF_RECORD_READ
,
6187 .size
= sizeof(read_event
) + event
->read_size
,
6189 .pid
= perf_event_pid(event
, task
),
6190 .tid
= perf_event_tid(event
, task
),
6194 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6195 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6199 perf_output_put(&handle
, read_event
);
6200 perf_output_read(&handle
, event
);
6201 perf_event__output_id_sample(event
, &handle
, &sample
);
6203 perf_output_end(&handle
);
6206 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6209 perf_iterate_ctx(struct perf_event_context
*ctx
,
6210 perf_iterate_f output
,
6211 void *data
, bool all
)
6213 struct perf_event
*event
;
6215 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6217 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6219 if (!event_filter_match(event
))
6223 output(event
, data
);
6227 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6229 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6230 struct perf_event
*event
;
6232 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6234 * Skip events that are not fully formed yet; ensure that
6235 * if we observe event->ctx, both event and ctx will be
6236 * complete enough. See perf_install_in_context().
6238 if (!smp_load_acquire(&event
->ctx
))
6241 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6243 if (!event_filter_match(event
))
6245 output(event
, data
);
6250 * Iterate all events that need to receive side-band events.
6252 * For new callers; ensure that account_pmu_sb_event() includes
6253 * your event, otherwise it might not get delivered.
6256 perf_iterate_sb(perf_iterate_f output
, void *data
,
6257 struct perf_event_context
*task_ctx
)
6259 struct perf_event_context
*ctx
;
6266 * If we have task_ctx != NULL we only notify the task context itself.
6267 * The task_ctx is set only for EXIT events before releasing task
6271 perf_iterate_ctx(task_ctx
, output
, data
, false);
6275 perf_iterate_sb_cpu(output
, data
);
6277 for_each_task_context_nr(ctxn
) {
6278 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6280 perf_iterate_ctx(ctx
, output
, data
, false);
6288 * Clear all file-based filters at exec, they'll have to be
6289 * re-instated when/if these objects are mmapped again.
6291 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6293 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6294 struct perf_addr_filter
*filter
;
6295 unsigned int restart
= 0, count
= 0;
6296 unsigned long flags
;
6298 if (!has_addr_filter(event
))
6301 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6302 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6303 if (filter
->inode
) {
6304 event
->addr_filters_offs
[count
] = 0;
6312 event
->addr_filters_gen
++;
6313 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6316 perf_event_stop(event
, 1);
6319 void perf_event_exec(void)
6321 struct perf_event_context
*ctx
;
6325 for_each_task_context_nr(ctxn
) {
6326 ctx
= current
->perf_event_ctxp
[ctxn
];
6330 perf_event_enable_on_exec(ctxn
);
6332 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6338 struct remote_output
{
6339 struct ring_buffer
*rb
;
6343 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6345 struct perf_event
*parent
= event
->parent
;
6346 struct remote_output
*ro
= data
;
6347 struct ring_buffer
*rb
= ro
->rb
;
6348 struct stop_event_data sd
= {
6352 if (!has_aux(event
))
6359 * In case of inheritance, it will be the parent that links to the
6360 * ring-buffer, but it will be the child that's actually using it.
6362 * We are using event::rb to determine if the event should be stopped,
6363 * however this may race with ring_buffer_attach() (through set_output),
6364 * which will make us skip the event that actually needs to be stopped.
6365 * So ring_buffer_attach() has to stop an aux event before re-assigning
6368 if (rcu_dereference(parent
->rb
) == rb
)
6369 ro
->err
= __perf_event_stop(&sd
);
6372 static int __perf_pmu_output_stop(void *info
)
6374 struct perf_event
*event
= info
;
6375 struct pmu
*pmu
= event
->pmu
;
6376 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6377 struct remote_output ro
= {
6382 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6383 if (cpuctx
->task_ctx
)
6384 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6391 static void perf_pmu_output_stop(struct perf_event
*event
)
6393 struct perf_event
*iter
;
6398 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6400 * For per-CPU events, we need to make sure that neither they
6401 * nor their children are running; for cpu==-1 events it's
6402 * sufficient to stop the event itself if it's active, since
6403 * it can't have children.
6407 cpu
= READ_ONCE(iter
->oncpu
);
6412 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6413 if (err
== -EAGAIN
) {
6422 * task tracking -- fork/exit
6424 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6427 struct perf_task_event
{
6428 struct task_struct
*task
;
6429 struct perf_event_context
*task_ctx
;
6432 struct perf_event_header header
;
6442 static int perf_event_task_match(struct perf_event
*event
)
6444 return event
->attr
.comm
|| event
->attr
.mmap
||
6445 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6449 static void perf_event_task_output(struct perf_event
*event
,
6452 struct perf_task_event
*task_event
= data
;
6453 struct perf_output_handle handle
;
6454 struct perf_sample_data sample
;
6455 struct task_struct
*task
= task_event
->task
;
6456 int ret
, size
= task_event
->event_id
.header
.size
;
6458 if (!perf_event_task_match(event
))
6461 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6463 ret
= perf_output_begin(&handle
, event
,
6464 task_event
->event_id
.header
.size
);
6468 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6469 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6471 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6472 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6474 task_event
->event_id
.time
= perf_event_clock(event
);
6476 perf_output_put(&handle
, task_event
->event_id
);
6478 perf_event__output_id_sample(event
, &handle
, &sample
);
6480 perf_output_end(&handle
);
6482 task_event
->event_id
.header
.size
= size
;
6485 static void perf_event_task(struct task_struct
*task
,
6486 struct perf_event_context
*task_ctx
,
6489 struct perf_task_event task_event
;
6491 if (!atomic_read(&nr_comm_events
) &&
6492 !atomic_read(&nr_mmap_events
) &&
6493 !atomic_read(&nr_task_events
))
6496 task_event
= (struct perf_task_event
){
6498 .task_ctx
= task_ctx
,
6501 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6503 .size
= sizeof(task_event
.event_id
),
6513 perf_iterate_sb(perf_event_task_output
,
6518 void perf_event_fork(struct task_struct
*task
)
6520 perf_event_task(task
, NULL
, 1);
6521 perf_event_namespaces(task
);
6528 struct perf_comm_event
{
6529 struct task_struct
*task
;
6534 struct perf_event_header header
;
6541 static int perf_event_comm_match(struct perf_event
*event
)
6543 return event
->attr
.comm
;
6546 static void perf_event_comm_output(struct perf_event
*event
,
6549 struct perf_comm_event
*comm_event
= data
;
6550 struct perf_output_handle handle
;
6551 struct perf_sample_data sample
;
6552 int size
= comm_event
->event_id
.header
.size
;
6555 if (!perf_event_comm_match(event
))
6558 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6559 ret
= perf_output_begin(&handle
, event
,
6560 comm_event
->event_id
.header
.size
);
6565 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6566 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6568 perf_output_put(&handle
, comm_event
->event_id
);
6569 __output_copy(&handle
, comm_event
->comm
,
6570 comm_event
->comm_size
);
6572 perf_event__output_id_sample(event
, &handle
, &sample
);
6574 perf_output_end(&handle
);
6576 comm_event
->event_id
.header
.size
= size
;
6579 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6581 char comm
[TASK_COMM_LEN
];
6584 memset(comm
, 0, sizeof(comm
));
6585 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6586 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6588 comm_event
->comm
= comm
;
6589 comm_event
->comm_size
= size
;
6591 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6593 perf_iterate_sb(perf_event_comm_output
,
6598 void perf_event_comm(struct task_struct
*task
, bool exec
)
6600 struct perf_comm_event comm_event
;
6602 if (!atomic_read(&nr_comm_events
))
6605 comm_event
= (struct perf_comm_event
){
6611 .type
= PERF_RECORD_COMM
,
6612 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6620 perf_event_comm_event(&comm_event
);
6624 * namespaces tracking
6627 struct perf_namespaces_event
{
6628 struct task_struct
*task
;
6631 struct perf_event_header header
;
6636 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6640 static int perf_event_namespaces_match(struct perf_event
*event
)
6642 return event
->attr
.namespaces
;
6645 static void perf_event_namespaces_output(struct perf_event
*event
,
6648 struct perf_namespaces_event
*namespaces_event
= data
;
6649 struct perf_output_handle handle
;
6650 struct perf_sample_data sample
;
6651 u16 header_size
= namespaces_event
->event_id
.header
.size
;
6654 if (!perf_event_namespaces_match(event
))
6657 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6659 ret
= perf_output_begin(&handle
, event
,
6660 namespaces_event
->event_id
.header
.size
);
6664 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6665 namespaces_event
->task
);
6666 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6667 namespaces_event
->task
);
6669 perf_output_put(&handle
, namespaces_event
->event_id
);
6671 perf_event__output_id_sample(event
, &handle
, &sample
);
6673 perf_output_end(&handle
);
6675 namespaces_event
->event_id
.header
.size
= header_size
;
6678 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6679 struct task_struct
*task
,
6680 const struct proc_ns_operations
*ns_ops
)
6682 struct path ns_path
;
6683 struct inode
*ns_inode
;
6686 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6688 ns_inode
= ns_path
.dentry
->d_inode
;
6689 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6690 ns_link_info
->ino
= ns_inode
->i_ino
;
6695 void perf_event_namespaces(struct task_struct
*task
)
6697 struct perf_namespaces_event namespaces_event
;
6698 struct perf_ns_link_info
*ns_link_info
;
6700 if (!atomic_read(&nr_namespaces_events
))
6703 namespaces_event
= (struct perf_namespaces_event
){
6707 .type
= PERF_RECORD_NAMESPACES
,
6709 .size
= sizeof(namespaces_event
.event_id
),
6713 .nr_namespaces
= NR_NAMESPACES
,
6714 /* .link_info[NR_NAMESPACES] */
6718 ns_link_info
= namespaces_event
.event_id
.link_info
;
6720 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6721 task
, &mntns_operations
);
6723 #ifdef CONFIG_USER_NS
6724 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6725 task
, &userns_operations
);
6727 #ifdef CONFIG_NET_NS
6728 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6729 task
, &netns_operations
);
6731 #ifdef CONFIG_UTS_NS
6732 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6733 task
, &utsns_operations
);
6735 #ifdef CONFIG_IPC_NS
6736 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6737 task
, &ipcns_operations
);
6739 #ifdef CONFIG_PID_NS
6740 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6741 task
, &pidns_operations
);
6743 #ifdef CONFIG_CGROUPS
6744 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6745 task
, &cgroupns_operations
);
6748 perf_iterate_sb(perf_event_namespaces_output
,
6757 struct perf_mmap_event
{
6758 struct vm_area_struct
*vma
;
6760 const char *file_name
;
6768 struct perf_event_header header
;
6778 static int perf_event_mmap_match(struct perf_event
*event
,
6781 struct perf_mmap_event
*mmap_event
= data
;
6782 struct vm_area_struct
*vma
= mmap_event
->vma
;
6783 int executable
= vma
->vm_flags
& VM_EXEC
;
6785 return (!executable
&& event
->attr
.mmap_data
) ||
6786 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6789 static void perf_event_mmap_output(struct perf_event
*event
,
6792 struct perf_mmap_event
*mmap_event
= data
;
6793 struct perf_output_handle handle
;
6794 struct perf_sample_data sample
;
6795 int size
= mmap_event
->event_id
.header
.size
;
6798 if (!perf_event_mmap_match(event
, data
))
6801 if (event
->attr
.mmap2
) {
6802 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6803 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6804 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6805 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6806 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6807 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6808 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6811 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6812 ret
= perf_output_begin(&handle
, event
,
6813 mmap_event
->event_id
.header
.size
);
6817 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6818 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6820 perf_output_put(&handle
, mmap_event
->event_id
);
6822 if (event
->attr
.mmap2
) {
6823 perf_output_put(&handle
, mmap_event
->maj
);
6824 perf_output_put(&handle
, mmap_event
->min
);
6825 perf_output_put(&handle
, mmap_event
->ino
);
6826 perf_output_put(&handle
, mmap_event
->ino_generation
);
6827 perf_output_put(&handle
, mmap_event
->prot
);
6828 perf_output_put(&handle
, mmap_event
->flags
);
6831 __output_copy(&handle
, mmap_event
->file_name
,
6832 mmap_event
->file_size
);
6834 perf_event__output_id_sample(event
, &handle
, &sample
);
6836 perf_output_end(&handle
);
6838 mmap_event
->event_id
.header
.size
= size
;
6841 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6843 struct vm_area_struct
*vma
= mmap_event
->vma
;
6844 struct file
*file
= vma
->vm_file
;
6845 int maj
= 0, min
= 0;
6846 u64 ino
= 0, gen
= 0;
6847 u32 prot
= 0, flags
= 0;
6853 if (vma
->vm_flags
& VM_READ
)
6855 if (vma
->vm_flags
& VM_WRITE
)
6857 if (vma
->vm_flags
& VM_EXEC
)
6860 if (vma
->vm_flags
& VM_MAYSHARE
)
6863 flags
= MAP_PRIVATE
;
6865 if (vma
->vm_flags
& VM_DENYWRITE
)
6866 flags
|= MAP_DENYWRITE
;
6867 if (vma
->vm_flags
& VM_MAYEXEC
)
6868 flags
|= MAP_EXECUTABLE
;
6869 if (vma
->vm_flags
& VM_LOCKED
)
6870 flags
|= MAP_LOCKED
;
6871 if (vma
->vm_flags
& VM_HUGETLB
)
6872 flags
|= MAP_HUGETLB
;
6875 struct inode
*inode
;
6878 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6884 * d_path() works from the end of the rb backwards, so we
6885 * need to add enough zero bytes after the string to handle
6886 * the 64bit alignment we do later.
6888 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6893 inode
= file_inode(vma
->vm_file
);
6894 dev
= inode
->i_sb
->s_dev
;
6896 gen
= inode
->i_generation
;
6902 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6903 name
= (char *) vma
->vm_ops
->name(vma
);
6908 name
= (char *)arch_vma_name(vma
);
6912 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6913 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6917 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6918 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6928 strlcpy(tmp
, name
, sizeof(tmp
));
6932 * Since our buffer works in 8 byte units we need to align our string
6933 * size to a multiple of 8. However, we must guarantee the tail end is
6934 * zero'd out to avoid leaking random bits to userspace.
6936 size
= strlen(name
)+1;
6937 while (!IS_ALIGNED(size
, sizeof(u64
)))
6938 name
[size
++] = '\0';
6940 mmap_event
->file_name
= name
;
6941 mmap_event
->file_size
= size
;
6942 mmap_event
->maj
= maj
;
6943 mmap_event
->min
= min
;
6944 mmap_event
->ino
= ino
;
6945 mmap_event
->ino_generation
= gen
;
6946 mmap_event
->prot
= prot
;
6947 mmap_event
->flags
= flags
;
6949 if (!(vma
->vm_flags
& VM_EXEC
))
6950 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6952 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6954 perf_iterate_sb(perf_event_mmap_output
,
6962 * Check whether inode and address range match filter criteria.
6964 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6965 struct file
*file
, unsigned long offset
,
6968 if (filter
->inode
!= file_inode(file
))
6971 if (filter
->offset
> offset
+ size
)
6974 if (filter
->offset
+ filter
->size
< offset
)
6980 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6982 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6983 struct vm_area_struct
*vma
= data
;
6984 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6985 struct file
*file
= vma
->vm_file
;
6986 struct perf_addr_filter
*filter
;
6987 unsigned int restart
= 0, count
= 0;
6989 if (!has_addr_filter(event
))
6995 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6996 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6997 if (perf_addr_filter_match(filter
, file
, off
,
6998 vma
->vm_end
- vma
->vm_start
)) {
6999 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7007 event
->addr_filters_gen
++;
7008 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7011 perf_event_stop(event
, 1);
7015 * Adjust all task's events' filters to the new vma
7017 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7019 struct perf_event_context
*ctx
;
7023 * Data tracing isn't supported yet and as such there is no need
7024 * to keep track of anything that isn't related to executable code:
7026 if (!(vma
->vm_flags
& VM_EXEC
))
7030 for_each_task_context_nr(ctxn
) {
7031 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7035 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7040 void perf_event_mmap(struct vm_area_struct
*vma
)
7042 struct perf_mmap_event mmap_event
;
7044 if (!atomic_read(&nr_mmap_events
))
7047 mmap_event
= (struct perf_mmap_event
){
7053 .type
= PERF_RECORD_MMAP
,
7054 .misc
= PERF_RECORD_MISC_USER
,
7059 .start
= vma
->vm_start
,
7060 .len
= vma
->vm_end
- vma
->vm_start
,
7061 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7063 /* .maj (attr_mmap2 only) */
7064 /* .min (attr_mmap2 only) */
7065 /* .ino (attr_mmap2 only) */
7066 /* .ino_generation (attr_mmap2 only) */
7067 /* .prot (attr_mmap2 only) */
7068 /* .flags (attr_mmap2 only) */
7071 perf_addr_filters_adjust(vma
);
7072 perf_event_mmap_event(&mmap_event
);
7075 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7076 unsigned long size
, u64 flags
)
7078 struct perf_output_handle handle
;
7079 struct perf_sample_data sample
;
7080 struct perf_aux_event
{
7081 struct perf_event_header header
;
7087 .type
= PERF_RECORD_AUX
,
7089 .size
= sizeof(rec
),
7097 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7098 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7103 perf_output_put(&handle
, rec
);
7104 perf_event__output_id_sample(event
, &handle
, &sample
);
7106 perf_output_end(&handle
);
7110 * Lost/dropped samples logging
7112 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7114 struct perf_output_handle handle
;
7115 struct perf_sample_data sample
;
7119 struct perf_event_header header
;
7121 } lost_samples_event
= {
7123 .type
= PERF_RECORD_LOST_SAMPLES
,
7125 .size
= sizeof(lost_samples_event
),
7130 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7132 ret
= perf_output_begin(&handle
, event
,
7133 lost_samples_event
.header
.size
);
7137 perf_output_put(&handle
, lost_samples_event
);
7138 perf_event__output_id_sample(event
, &handle
, &sample
);
7139 perf_output_end(&handle
);
7143 * context_switch tracking
7146 struct perf_switch_event
{
7147 struct task_struct
*task
;
7148 struct task_struct
*next_prev
;
7151 struct perf_event_header header
;
7157 static int perf_event_switch_match(struct perf_event
*event
)
7159 return event
->attr
.context_switch
;
7162 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7164 struct perf_switch_event
*se
= data
;
7165 struct perf_output_handle handle
;
7166 struct perf_sample_data sample
;
7169 if (!perf_event_switch_match(event
))
7172 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7173 if (event
->ctx
->task
) {
7174 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7175 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7177 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7178 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7179 se
->event_id
.next_prev_pid
=
7180 perf_event_pid(event
, se
->next_prev
);
7181 se
->event_id
.next_prev_tid
=
7182 perf_event_tid(event
, se
->next_prev
);
7185 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7187 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7191 if (event
->ctx
->task
)
7192 perf_output_put(&handle
, se
->event_id
.header
);
7194 perf_output_put(&handle
, se
->event_id
);
7196 perf_event__output_id_sample(event
, &handle
, &sample
);
7198 perf_output_end(&handle
);
7201 static void perf_event_switch(struct task_struct
*task
,
7202 struct task_struct
*next_prev
, bool sched_in
)
7204 struct perf_switch_event switch_event
;
7206 /* N.B. caller checks nr_switch_events != 0 */
7208 switch_event
= (struct perf_switch_event
){
7210 .next_prev
= next_prev
,
7214 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7217 /* .next_prev_pid */
7218 /* .next_prev_tid */
7222 perf_iterate_sb(perf_event_switch_output
,
7228 * IRQ throttle logging
7231 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7233 struct perf_output_handle handle
;
7234 struct perf_sample_data sample
;
7238 struct perf_event_header header
;
7242 } throttle_event
= {
7244 .type
= PERF_RECORD_THROTTLE
,
7246 .size
= sizeof(throttle_event
),
7248 .time
= perf_event_clock(event
),
7249 .id
= primary_event_id(event
),
7250 .stream_id
= event
->id
,
7254 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7256 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7258 ret
= perf_output_begin(&handle
, event
,
7259 throttle_event
.header
.size
);
7263 perf_output_put(&handle
, throttle_event
);
7264 perf_event__output_id_sample(event
, &handle
, &sample
);
7265 perf_output_end(&handle
);
7268 void perf_event_itrace_started(struct perf_event
*event
)
7270 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7273 static void perf_log_itrace_start(struct perf_event
*event
)
7275 struct perf_output_handle handle
;
7276 struct perf_sample_data sample
;
7277 struct perf_aux_event
{
7278 struct perf_event_header header
;
7285 event
= event
->parent
;
7287 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7288 event
->attach_state
& PERF_ATTACH_ITRACE
)
7291 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7292 rec
.header
.misc
= 0;
7293 rec
.header
.size
= sizeof(rec
);
7294 rec
.pid
= perf_event_pid(event
, current
);
7295 rec
.tid
= perf_event_tid(event
, current
);
7297 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7298 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7303 perf_output_put(&handle
, rec
);
7304 perf_event__output_id_sample(event
, &handle
, &sample
);
7306 perf_output_end(&handle
);
7310 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7312 struct hw_perf_event
*hwc
= &event
->hw
;
7316 seq
= __this_cpu_read(perf_throttled_seq
);
7317 if (seq
!= hwc
->interrupts_seq
) {
7318 hwc
->interrupts_seq
= seq
;
7319 hwc
->interrupts
= 1;
7322 if (unlikely(throttle
7323 && hwc
->interrupts
>= max_samples_per_tick
)) {
7324 __this_cpu_inc(perf_throttled_count
);
7325 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7326 hwc
->interrupts
= MAX_INTERRUPTS
;
7327 perf_log_throttle(event
, 0);
7332 if (event
->attr
.freq
) {
7333 u64 now
= perf_clock();
7334 s64 delta
= now
- hwc
->freq_time_stamp
;
7336 hwc
->freq_time_stamp
= now
;
7338 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7339 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7345 int perf_event_account_interrupt(struct perf_event
*event
)
7347 return __perf_event_account_interrupt(event
, 1);
7351 * Generic event overflow handling, sampling.
7354 static int __perf_event_overflow(struct perf_event
*event
,
7355 int throttle
, struct perf_sample_data
*data
,
7356 struct pt_regs
*regs
)
7358 int events
= atomic_read(&event
->event_limit
);
7362 * Non-sampling counters might still use the PMI to fold short
7363 * hardware counters, ignore those.
7365 if (unlikely(!is_sampling_event(event
)))
7368 ret
= __perf_event_account_interrupt(event
, throttle
);
7371 * XXX event_limit might not quite work as expected on inherited
7375 event
->pending_kill
= POLL_IN
;
7376 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7378 event
->pending_kill
= POLL_HUP
;
7380 perf_event_disable_inatomic(event
);
7383 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7385 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7386 event
->pending_wakeup
= 1;
7387 irq_work_queue(&event
->pending
);
7393 int perf_event_overflow(struct perf_event
*event
,
7394 struct perf_sample_data
*data
,
7395 struct pt_regs
*regs
)
7397 return __perf_event_overflow(event
, 1, data
, regs
);
7401 * Generic software event infrastructure
7404 struct swevent_htable
{
7405 struct swevent_hlist
*swevent_hlist
;
7406 struct mutex hlist_mutex
;
7409 /* Recursion avoidance in each contexts */
7410 int recursion
[PERF_NR_CONTEXTS
];
7413 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7416 * We directly increment event->count and keep a second value in
7417 * event->hw.period_left to count intervals. This period event
7418 * is kept in the range [-sample_period, 0] so that we can use the
7422 u64
perf_swevent_set_period(struct perf_event
*event
)
7424 struct hw_perf_event
*hwc
= &event
->hw
;
7425 u64 period
= hwc
->last_period
;
7429 hwc
->last_period
= hwc
->sample_period
;
7432 old
= val
= local64_read(&hwc
->period_left
);
7436 nr
= div64_u64(period
+ val
, period
);
7437 offset
= nr
* period
;
7439 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7445 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7446 struct perf_sample_data
*data
,
7447 struct pt_regs
*regs
)
7449 struct hw_perf_event
*hwc
= &event
->hw
;
7453 overflow
= perf_swevent_set_period(event
);
7455 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7458 for (; overflow
; overflow
--) {
7459 if (__perf_event_overflow(event
, throttle
,
7462 * We inhibit the overflow from happening when
7463 * hwc->interrupts == MAX_INTERRUPTS.
7471 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7472 struct perf_sample_data
*data
,
7473 struct pt_regs
*regs
)
7475 struct hw_perf_event
*hwc
= &event
->hw
;
7477 local64_add(nr
, &event
->count
);
7482 if (!is_sampling_event(event
))
7485 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7487 return perf_swevent_overflow(event
, 1, data
, regs
);
7489 data
->period
= event
->hw
.last_period
;
7491 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7492 return perf_swevent_overflow(event
, 1, data
, regs
);
7494 if (local64_add_negative(nr
, &hwc
->period_left
))
7497 perf_swevent_overflow(event
, 0, data
, regs
);
7500 static int perf_exclude_event(struct perf_event
*event
,
7501 struct pt_regs
*regs
)
7503 if (event
->hw
.state
& PERF_HES_STOPPED
)
7507 if (event
->attr
.exclude_user
&& user_mode(regs
))
7510 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7517 static int perf_swevent_match(struct perf_event
*event
,
7518 enum perf_type_id type
,
7520 struct perf_sample_data
*data
,
7521 struct pt_regs
*regs
)
7523 if (event
->attr
.type
!= type
)
7526 if (event
->attr
.config
!= event_id
)
7529 if (perf_exclude_event(event
, regs
))
7535 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7537 u64 val
= event_id
| (type
<< 32);
7539 return hash_64(val
, SWEVENT_HLIST_BITS
);
7542 static inline struct hlist_head
*
7543 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7545 u64 hash
= swevent_hash(type
, event_id
);
7547 return &hlist
->heads
[hash
];
7550 /* For the read side: events when they trigger */
7551 static inline struct hlist_head
*
7552 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7554 struct swevent_hlist
*hlist
;
7556 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7560 return __find_swevent_head(hlist
, type
, event_id
);
7563 /* For the event head insertion and removal in the hlist */
7564 static inline struct hlist_head
*
7565 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7567 struct swevent_hlist
*hlist
;
7568 u32 event_id
= event
->attr
.config
;
7569 u64 type
= event
->attr
.type
;
7572 * Event scheduling is always serialized against hlist allocation
7573 * and release. Which makes the protected version suitable here.
7574 * The context lock guarantees that.
7576 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7577 lockdep_is_held(&event
->ctx
->lock
));
7581 return __find_swevent_head(hlist
, type
, event_id
);
7584 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7586 struct perf_sample_data
*data
,
7587 struct pt_regs
*regs
)
7589 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7590 struct perf_event
*event
;
7591 struct hlist_head
*head
;
7594 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7598 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7599 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7600 perf_swevent_event(event
, nr
, data
, regs
);
7606 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7608 int perf_swevent_get_recursion_context(void)
7610 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7612 return get_recursion_context(swhash
->recursion
);
7614 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7616 void perf_swevent_put_recursion_context(int rctx
)
7618 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7620 put_recursion_context(swhash
->recursion
, rctx
);
7623 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7625 struct perf_sample_data data
;
7627 if (WARN_ON_ONCE(!regs
))
7630 perf_sample_data_init(&data
, addr
, 0);
7631 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7634 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7638 preempt_disable_notrace();
7639 rctx
= perf_swevent_get_recursion_context();
7640 if (unlikely(rctx
< 0))
7643 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7645 perf_swevent_put_recursion_context(rctx
);
7647 preempt_enable_notrace();
7650 static void perf_swevent_read(struct perf_event
*event
)
7654 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7656 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7657 struct hw_perf_event
*hwc
= &event
->hw
;
7658 struct hlist_head
*head
;
7660 if (is_sampling_event(event
)) {
7661 hwc
->last_period
= hwc
->sample_period
;
7662 perf_swevent_set_period(event
);
7665 hwc
->state
= !(flags
& PERF_EF_START
);
7667 head
= find_swevent_head(swhash
, event
);
7668 if (WARN_ON_ONCE(!head
))
7671 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7672 perf_event_update_userpage(event
);
7677 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7679 hlist_del_rcu(&event
->hlist_entry
);
7682 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7684 event
->hw
.state
= 0;
7687 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7689 event
->hw
.state
= PERF_HES_STOPPED
;
7692 /* Deref the hlist from the update side */
7693 static inline struct swevent_hlist
*
7694 swevent_hlist_deref(struct swevent_htable
*swhash
)
7696 return rcu_dereference_protected(swhash
->swevent_hlist
,
7697 lockdep_is_held(&swhash
->hlist_mutex
));
7700 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7702 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7707 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7708 kfree_rcu(hlist
, rcu_head
);
7711 static void swevent_hlist_put_cpu(int cpu
)
7713 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7715 mutex_lock(&swhash
->hlist_mutex
);
7717 if (!--swhash
->hlist_refcount
)
7718 swevent_hlist_release(swhash
);
7720 mutex_unlock(&swhash
->hlist_mutex
);
7723 static void swevent_hlist_put(void)
7727 for_each_possible_cpu(cpu
)
7728 swevent_hlist_put_cpu(cpu
);
7731 static int swevent_hlist_get_cpu(int cpu
)
7733 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7736 mutex_lock(&swhash
->hlist_mutex
);
7737 if (!swevent_hlist_deref(swhash
) &&
7738 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7739 struct swevent_hlist
*hlist
;
7741 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7746 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7748 swhash
->hlist_refcount
++;
7750 mutex_unlock(&swhash
->hlist_mutex
);
7755 static int swevent_hlist_get(void)
7757 int err
, cpu
, failed_cpu
;
7759 mutex_lock(&pmus_lock
);
7760 for_each_possible_cpu(cpu
) {
7761 err
= swevent_hlist_get_cpu(cpu
);
7767 mutex_unlock(&pmus_lock
);
7770 for_each_possible_cpu(cpu
) {
7771 if (cpu
== failed_cpu
)
7773 swevent_hlist_put_cpu(cpu
);
7775 mutex_unlock(&pmus_lock
);
7779 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7781 static void sw_perf_event_destroy(struct perf_event
*event
)
7783 u64 event_id
= event
->attr
.config
;
7785 WARN_ON(event
->parent
);
7787 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7788 swevent_hlist_put();
7791 static int perf_swevent_init(struct perf_event
*event
)
7793 u64 event_id
= event
->attr
.config
;
7795 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7799 * no branch sampling for software events
7801 if (has_branch_stack(event
))
7805 case PERF_COUNT_SW_CPU_CLOCK
:
7806 case PERF_COUNT_SW_TASK_CLOCK
:
7813 if (event_id
>= PERF_COUNT_SW_MAX
)
7816 if (!event
->parent
) {
7819 err
= swevent_hlist_get();
7823 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7824 event
->destroy
= sw_perf_event_destroy
;
7830 static struct pmu perf_swevent
= {
7831 .task_ctx_nr
= perf_sw_context
,
7833 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7835 .event_init
= perf_swevent_init
,
7836 .add
= perf_swevent_add
,
7837 .del
= perf_swevent_del
,
7838 .start
= perf_swevent_start
,
7839 .stop
= perf_swevent_stop
,
7840 .read
= perf_swevent_read
,
7843 #ifdef CONFIG_EVENT_TRACING
7845 static int perf_tp_filter_match(struct perf_event
*event
,
7846 struct perf_sample_data
*data
)
7848 void *record
= data
->raw
->frag
.data
;
7850 /* only top level events have filters set */
7852 event
= event
->parent
;
7854 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7859 static int perf_tp_event_match(struct perf_event
*event
,
7860 struct perf_sample_data
*data
,
7861 struct pt_regs
*regs
)
7863 if (event
->hw
.state
& PERF_HES_STOPPED
)
7866 * All tracepoints are from kernel-space.
7868 if (event
->attr
.exclude_kernel
)
7871 if (!perf_tp_filter_match(event
, data
))
7877 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7878 struct trace_event_call
*call
, u64 count
,
7879 struct pt_regs
*regs
, struct hlist_head
*head
,
7880 struct task_struct
*task
)
7882 if (bpf_prog_array_valid(call
)) {
7883 *(struct pt_regs
**)raw_data
= regs
;
7884 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
7885 perf_swevent_put_recursion_context(rctx
);
7889 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7892 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7894 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7895 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7896 struct task_struct
*task
)
7898 struct perf_sample_data data
;
7899 struct perf_event
*event
;
7901 struct perf_raw_record raw
= {
7908 perf_sample_data_init(&data
, 0, 0);
7911 perf_trace_buf_update(record
, event_type
);
7913 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7914 if (perf_tp_event_match(event
, &data
, regs
))
7915 perf_swevent_event(event
, count
, &data
, regs
);
7919 * If we got specified a target task, also iterate its context and
7920 * deliver this event there too.
7922 if (task
&& task
!= current
) {
7923 struct perf_event_context
*ctx
;
7924 struct trace_entry
*entry
= record
;
7927 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7931 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7932 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7934 if (event
->attr
.config
!= entry
->type
)
7936 if (perf_tp_event_match(event
, &data
, regs
))
7937 perf_swevent_event(event
, count
, &data
, regs
);
7943 perf_swevent_put_recursion_context(rctx
);
7945 EXPORT_SYMBOL_GPL(perf_tp_event
);
7947 static void tp_perf_event_destroy(struct perf_event
*event
)
7949 perf_trace_destroy(event
);
7952 static int perf_tp_event_init(struct perf_event
*event
)
7956 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7960 * no branch sampling for tracepoint events
7962 if (has_branch_stack(event
))
7965 err
= perf_trace_init(event
);
7969 event
->destroy
= tp_perf_event_destroy
;
7974 static struct pmu perf_tracepoint
= {
7975 .task_ctx_nr
= perf_sw_context
,
7977 .event_init
= perf_tp_event_init
,
7978 .add
= perf_trace_add
,
7979 .del
= perf_trace_del
,
7980 .start
= perf_swevent_start
,
7981 .stop
= perf_swevent_stop
,
7982 .read
= perf_swevent_read
,
7985 static inline void perf_tp_register(void)
7987 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7990 static void perf_event_free_filter(struct perf_event
*event
)
7992 ftrace_profile_free_filter(event
);
7995 #ifdef CONFIG_BPF_SYSCALL
7996 static void bpf_overflow_handler(struct perf_event
*event
,
7997 struct perf_sample_data
*data
,
7998 struct pt_regs
*regs
)
8000 struct bpf_perf_event_data_kern ctx
= {
8006 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
8008 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8011 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8014 __this_cpu_dec(bpf_prog_active
);
8019 event
->orig_overflow_handler(event
, data
, regs
);
8022 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8024 struct bpf_prog
*prog
;
8026 if (event
->overflow_handler_context
)
8027 /* hw breakpoint or kernel counter */
8033 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8035 return PTR_ERR(prog
);
8038 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8039 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8043 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8045 struct bpf_prog
*prog
= event
->prog
;
8050 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8055 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8059 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8064 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8066 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8067 struct bpf_prog
*prog
;
8070 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8071 return perf_event_set_bpf_handler(event
, prog_fd
);
8073 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8074 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8075 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8076 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8077 /* bpf programs can only be attached to u/kprobe or tracepoint */
8080 prog
= bpf_prog_get(prog_fd
);
8082 return PTR_ERR(prog
);
8084 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8085 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8086 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8087 /* valid fd, but invalid bpf program type */
8092 if (is_tracepoint
|| is_syscall_tp
) {
8093 int off
= trace_event_get_offsets(event
->tp_event
);
8095 if (prog
->aux
->max_ctx_offset
> off
) {
8101 ret
= perf_event_attach_bpf_prog(event
, prog
);
8107 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8109 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
) {
8110 perf_event_free_bpf_handler(event
);
8113 perf_event_detach_bpf_prog(event
);
8118 static inline void perf_tp_register(void)
8122 static void perf_event_free_filter(struct perf_event
*event
)
8126 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8131 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8134 #endif /* CONFIG_EVENT_TRACING */
8136 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8137 void perf_bp_event(struct perf_event
*bp
, void *data
)
8139 struct perf_sample_data sample
;
8140 struct pt_regs
*regs
= data
;
8142 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8144 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8145 perf_swevent_event(bp
, 1, &sample
, regs
);
8150 * Allocate a new address filter
8152 static struct perf_addr_filter
*
8153 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8155 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8156 struct perf_addr_filter
*filter
;
8158 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8162 INIT_LIST_HEAD(&filter
->entry
);
8163 list_add_tail(&filter
->entry
, filters
);
8168 static void free_filters_list(struct list_head
*filters
)
8170 struct perf_addr_filter
*filter
, *iter
;
8172 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8174 iput(filter
->inode
);
8175 list_del(&filter
->entry
);
8181 * Free existing address filters and optionally install new ones
8183 static void perf_addr_filters_splice(struct perf_event
*event
,
8184 struct list_head
*head
)
8186 unsigned long flags
;
8189 if (!has_addr_filter(event
))
8192 /* don't bother with children, they don't have their own filters */
8196 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8198 list_splice_init(&event
->addr_filters
.list
, &list
);
8200 list_splice(head
, &event
->addr_filters
.list
);
8202 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8204 free_filters_list(&list
);
8208 * Scan through mm's vmas and see if one of them matches the
8209 * @filter; if so, adjust filter's address range.
8210 * Called with mm::mmap_sem down for reading.
8212 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8213 struct mm_struct
*mm
)
8215 struct vm_area_struct
*vma
;
8217 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8218 struct file
*file
= vma
->vm_file
;
8219 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8220 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8225 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8228 return vma
->vm_start
;
8235 * Update event's address range filters based on the
8236 * task's existing mappings, if any.
8238 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8240 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8241 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8242 struct perf_addr_filter
*filter
;
8243 struct mm_struct
*mm
= NULL
;
8244 unsigned int count
= 0;
8245 unsigned long flags
;
8248 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8249 * will stop on the parent's child_mutex that our caller is also holding
8251 if (task
== TASK_TOMBSTONE
)
8254 if (!ifh
->nr_file_filters
)
8257 mm
= get_task_mm(event
->ctx
->task
);
8261 down_read(&mm
->mmap_sem
);
8263 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8264 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8265 event
->addr_filters_offs
[count
] = 0;
8268 * Adjust base offset if the filter is associated to a binary
8269 * that needs to be mapped:
8272 event
->addr_filters_offs
[count
] =
8273 perf_addr_filter_apply(filter
, mm
);
8278 event
->addr_filters_gen
++;
8279 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8281 up_read(&mm
->mmap_sem
);
8286 perf_event_stop(event
, 1);
8290 * Address range filtering: limiting the data to certain
8291 * instruction address ranges. Filters are ioctl()ed to us from
8292 * userspace as ascii strings.
8294 * Filter string format:
8297 * where ACTION is one of the
8298 * * "filter": limit the trace to this region
8299 * * "start": start tracing from this address
8300 * * "stop": stop tracing at this address/region;
8302 * * for kernel addresses: <start address>[/<size>]
8303 * * for object files: <start address>[/<size>]@</path/to/object/file>
8305 * if <size> is not specified, the range is treated as a single address.
8319 IF_STATE_ACTION
= 0,
8324 static const match_table_t if_tokens
= {
8325 { IF_ACT_FILTER
, "filter" },
8326 { IF_ACT_START
, "start" },
8327 { IF_ACT_STOP
, "stop" },
8328 { IF_SRC_FILE
, "%u/%u@%s" },
8329 { IF_SRC_KERNEL
, "%u/%u" },
8330 { IF_SRC_FILEADDR
, "%u@%s" },
8331 { IF_SRC_KERNELADDR
, "%u" },
8332 { IF_ACT_NONE
, NULL
},
8336 * Address filter string parser
8339 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8340 struct list_head
*filters
)
8342 struct perf_addr_filter
*filter
= NULL
;
8343 char *start
, *orig
, *filename
= NULL
;
8345 substring_t args
[MAX_OPT_ARGS
];
8346 int state
= IF_STATE_ACTION
, token
;
8347 unsigned int kernel
= 0;
8350 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8354 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8360 /* filter definition begins */
8361 if (state
== IF_STATE_ACTION
) {
8362 filter
= perf_addr_filter_new(event
, filters
);
8367 token
= match_token(start
, if_tokens
, args
);
8374 if (state
!= IF_STATE_ACTION
)
8377 state
= IF_STATE_SOURCE
;
8380 case IF_SRC_KERNELADDR
:
8384 case IF_SRC_FILEADDR
:
8386 if (state
!= IF_STATE_SOURCE
)
8389 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8393 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8397 if (filter
->range
) {
8399 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8404 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8405 int fpos
= filter
->range
? 2 : 1;
8407 filename
= match_strdup(&args
[fpos
]);
8414 state
= IF_STATE_END
;
8422 * Filter definition is fully parsed, validate and install it.
8423 * Make sure that it doesn't contradict itself or the event's
8426 if (state
== IF_STATE_END
) {
8428 if (kernel
&& event
->attr
.exclude_kernel
)
8436 * For now, we only support file-based filters
8437 * in per-task events; doing so for CPU-wide
8438 * events requires additional context switching
8439 * trickery, since same object code will be
8440 * mapped at different virtual addresses in
8441 * different processes.
8444 if (!event
->ctx
->task
)
8445 goto fail_free_name
;
8447 /* look up the path and grab its inode */
8448 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8450 goto fail_free_name
;
8452 filter
->inode
= igrab(d_inode(path
.dentry
));
8458 if (!filter
->inode
||
8459 !S_ISREG(filter
->inode
->i_mode
))
8460 /* free_filters_list() will iput() */
8463 event
->addr_filters
.nr_file_filters
++;
8466 /* ready to consume more filters */
8467 state
= IF_STATE_ACTION
;
8472 if (state
!= IF_STATE_ACTION
)
8482 free_filters_list(filters
);
8489 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8495 * Since this is called in perf_ioctl() path, we're already holding
8498 lockdep_assert_held(&event
->ctx
->mutex
);
8500 if (WARN_ON_ONCE(event
->parent
))
8503 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8505 goto fail_clear_files
;
8507 ret
= event
->pmu
->addr_filters_validate(&filters
);
8509 goto fail_free_filters
;
8511 /* remove existing filters, if any */
8512 perf_addr_filters_splice(event
, &filters
);
8514 /* install new filters */
8515 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8520 free_filters_list(&filters
);
8523 event
->addr_filters
.nr_file_filters
= 0;
8529 perf_tracepoint_set_filter(struct perf_event
*event
, char *filter_str
)
8531 struct perf_event_context
*ctx
= event
->ctx
;
8535 * Beware, here be dragons!!
8537 * the tracepoint muck will deadlock against ctx->mutex, but the tracepoint
8538 * stuff does not actually need it. So temporarily drop ctx->mutex. As per
8539 * perf_event_ctx_lock() we already have a reference on ctx.
8541 * This can result in event getting moved to a different ctx, but that
8542 * does not affect the tracepoint state.
8544 mutex_unlock(&ctx
->mutex
);
8545 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
8546 mutex_lock(&ctx
->mutex
);
8551 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8556 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8557 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8558 !has_addr_filter(event
))
8561 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8562 if (IS_ERR(filter_str
))
8563 return PTR_ERR(filter_str
);
8565 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8566 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8567 ret
= perf_tracepoint_set_filter(event
, filter_str
);
8568 else if (has_addr_filter(event
))
8569 ret
= perf_event_set_addr_filter(event
, filter_str
);
8576 * hrtimer based swevent callback
8579 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8581 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8582 struct perf_sample_data data
;
8583 struct pt_regs
*regs
;
8584 struct perf_event
*event
;
8587 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8589 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8590 return HRTIMER_NORESTART
;
8592 event
->pmu
->read(event
);
8594 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8595 regs
= get_irq_regs();
8597 if (regs
&& !perf_exclude_event(event
, regs
)) {
8598 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8599 if (__perf_event_overflow(event
, 1, &data
, regs
))
8600 ret
= HRTIMER_NORESTART
;
8603 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8604 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8609 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8611 struct hw_perf_event
*hwc
= &event
->hw
;
8614 if (!is_sampling_event(event
))
8617 period
= local64_read(&hwc
->period_left
);
8622 local64_set(&hwc
->period_left
, 0);
8624 period
= max_t(u64
, 10000, hwc
->sample_period
);
8626 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8627 HRTIMER_MODE_REL_PINNED
);
8630 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8632 struct hw_perf_event
*hwc
= &event
->hw
;
8634 if (is_sampling_event(event
)) {
8635 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8636 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8638 hrtimer_cancel(&hwc
->hrtimer
);
8642 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8644 struct hw_perf_event
*hwc
= &event
->hw
;
8646 if (!is_sampling_event(event
))
8649 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8650 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8653 * Since hrtimers have a fixed rate, we can do a static freq->period
8654 * mapping and avoid the whole period adjust feedback stuff.
8656 if (event
->attr
.freq
) {
8657 long freq
= event
->attr
.sample_freq
;
8659 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8660 hwc
->sample_period
= event
->attr
.sample_period
;
8661 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8662 hwc
->last_period
= hwc
->sample_period
;
8663 event
->attr
.freq
= 0;
8668 * Software event: cpu wall time clock
8671 static void cpu_clock_event_update(struct perf_event
*event
)
8676 now
= local_clock();
8677 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8678 local64_add(now
- prev
, &event
->count
);
8681 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8683 local64_set(&event
->hw
.prev_count
, local_clock());
8684 perf_swevent_start_hrtimer(event
);
8687 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8689 perf_swevent_cancel_hrtimer(event
);
8690 cpu_clock_event_update(event
);
8693 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8695 if (flags
& PERF_EF_START
)
8696 cpu_clock_event_start(event
, flags
);
8697 perf_event_update_userpage(event
);
8702 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8704 cpu_clock_event_stop(event
, flags
);
8707 static void cpu_clock_event_read(struct perf_event
*event
)
8709 cpu_clock_event_update(event
);
8712 static int cpu_clock_event_init(struct perf_event
*event
)
8714 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8717 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8721 * no branch sampling for software events
8723 if (has_branch_stack(event
))
8726 perf_swevent_init_hrtimer(event
);
8731 static struct pmu perf_cpu_clock
= {
8732 .task_ctx_nr
= perf_sw_context
,
8734 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8736 .event_init
= cpu_clock_event_init
,
8737 .add
= cpu_clock_event_add
,
8738 .del
= cpu_clock_event_del
,
8739 .start
= cpu_clock_event_start
,
8740 .stop
= cpu_clock_event_stop
,
8741 .read
= cpu_clock_event_read
,
8745 * Software event: task time clock
8748 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8753 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8755 local64_add(delta
, &event
->count
);
8758 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8760 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8761 perf_swevent_start_hrtimer(event
);
8764 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8766 perf_swevent_cancel_hrtimer(event
);
8767 task_clock_event_update(event
, event
->ctx
->time
);
8770 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8772 if (flags
& PERF_EF_START
)
8773 task_clock_event_start(event
, flags
);
8774 perf_event_update_userpage(event
);
8779 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8781 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8784 static void task_clock_event_read(struct perf_event
*event
)
8786 u64 now
= perf_clock();
8787 u64 delta
= now
- event
->ctx
->timestamp
;
8788 u64 time
= event
->ctx
->time
+ delta
;
8790 task_clock_event_update(event
, time
);
8793 static int task_clock_event_init(struct perf_event
*event
)
8795 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8798 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8802 * no branch sampling for software events
8804 if (has_branch_stack(event
))
8807 perf_swevent_init_hrtimer(event
);
8812 static struct pmu perf_task_clock
= {
8813 .task_ctx_nr
= perf_sw_context
,
8815 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8817 .event_init
= task_clock_event_init
,
8818 .add
= task_clock_event_add
,
8819 .del
= task_clock_event_del
,
8820 .start
= task_clock_event_start
,
8821 .stop
= task_clock_event_stop
,
8822 .read
= task_clock_event_read
,
8825 static void perf_pmu_nop_void(struct pmu
*pmu
)
8829 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8833 static int perf_pmu_nop_int(struct pmu
*pmu
)
8838 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8840 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8842 __this_cpu_write(nop_txn_flags
, flags
);
8844 if (flags
& ~PERF_PMU_TXN_ADD
)
8847 perf_pmu_disable(pmu
);
8850 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8852 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8854 __this_cpu_write(nop_txn_flags
, 0);
8856 if (flags
& ~PERF_PMU_TXN_ADD
)
8859 perf_pmu_enable(pmu
);
8863 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8865 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8867 __this_cpu_write(nop_txn_flags
, 0);
8869 if (flags
& ~PERF_PMU_TXN_ADD
)
8872 perf_pmu_enable(pmu
);
8875 static int perf_event_idx_default(struct perf_event
*event
)
8881 * Ensures all contexts with the same task_ctx_nr have the same
8882 * pmu_cpu_context too.
8884 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8891 list_for_each_entry(pmu
, &pmus
, entry
) {
8892 if (pmu
->task_ctx_nr
== ctxn
)
8893 return pmu
->pmu_cpu_context
;
8899 static void free_pmu_context(struct pmu
*pmu
)
8902 * Static contexts such as perf_sw_context have a global lifetime
8903 * and may be shared between different PMUs. Avoid freeing them
8904 * when a single PMU is going away.
8906 if (pmu
->task_ctx_nr
> perf_invalid_context
)
8909 mutex_lock(&pmus_lock
);
8910 free_percpu(pmu
->pmu_cpu_context
);
8911 mutex_unlock(&pmus_lock
);
8915 * Let userspace know that this PMU supports address range filtering:
8917 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8918 struct device_attribute
*attr
,
8921 struct pmu
*pmu
= dev_get_drvdata(dev
);
8923 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8925 DEVICE_ATTR_RO(nr_addr_filters
);
8927 static struct idr pmu_idr
;
8930 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8932 struct pmu
*pmu
= dev_get_drvdata(dev
);
8934 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8936 static DEVICE_ATTR_RO(type
);
8939 perf_event_mux_interval_ms_show(struct device
*dev
,
8940 struct device_attribute
*attr
,
8943 struct pmu
*pmu
= dev_get_drvdata(dev
);
8945 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8948 static DEFINE_MUTEX(mux_interval_mutex
);
8951 perf_event_mux_interval_ms_store(struct device
*dev
,
8952 struct device_attribute
*attr
,
8953 const char *buf
, size_t count
)
8955 struct pmu
*pmu
= dev_get_drvdata(dev
);
8956 int timer
, cpu
, ret
;
8958 ret
= kstrtoint(buf
, 0, &timer
);
8965 /* same value, noting to do */
8966 if (timer
== pmu
->hrtimer_interval_ms
)
8969 mutex_lock(&mux_interval_mutex
);
8970 pmu
->hrtimer_interval_ms
= timer
;
8972 /* update all cpuctx for this PMU */
8974 for_each_online_cpu(cpu
) {
8975 struct perf_cpu_context
*cpuctx
;
8976 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8977 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8979 cpu_function_call(cpu
,
8980 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8983 mutex_unlock(&mux_interval_mutex
);
8987 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8989 static struct attribute
*pmu_dev_attrs
[] = {
8990 &dev_attr_type
.attr
,
8991 &dev_attr_perf_event_mux_interval_ms
.attr
,
8994 ATTRIBUTE_GROUPS(pmu_dev
);
8996 static int pmu_bus_running
;
8997 static struct bus_type pmu_bus
= {
8998 .name
= "event_source",
8999 .dev_groups
= pmu_dev_groups
,
9002 static void pmu_dev_release(struct device
*dev
)
9007 static int pmu_dev_alloc(struct pmu
*pmu
)
9011 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9015 pmu
->dev
->groups
= pmu
->attr_groups
;
9016 device_initialize(pmu
->dev
);
9017 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9021 dev_set_drvdata(pmu
->dev
, pmu
);
9022 pmu
->dev
->bus
= &pmu_bus
;
9023 pmu
->dev
->release
= pmu_dev_release
;
9024 ret
= device_add(pmu
->dev
);
9028 /* For PMUs with address filters, throw in an extra attribute: */
9029 if (pmu
->nr_addr_filters
)
9030 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9039 device_del(pmu
->dev
);
9042 put_device(pmu
->dev
);
9046 static struct lock_class_key cpuctx_mutex
;
9047 static struct lock_class_key cpuctx_lock
;
9049 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9053 mutex_lock(&pmus_lock
);
9055 pmu
->pmu_disable_count
= alloc_percpu(int);
9056 if (!pmu
->pmu_disable_count
)
9065 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9073 if (pmu_bus_running
) {
9074 ret
= pmu_dev_alloc(pmu
);
9080 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9081 static int hw_context_taken
= 0;
9084 * Other than systems with heterogeneous CPUs, it never makes
9085 * sense for two PMUs to share perf_hw_context. PMUs which are
9086 * uncore must use perf_invalid_context.
9088 if (WARN_ON_ONCE(hw_context_taken
&&
9089 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9090 pmu
->task_ctx_nr
= perf_invalid_context
;
9092 hw_context_taken
= 1;
9095 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9096 if (pmu
->pmu_cpu_context
)
9097 goto got_cpu_context
;
9100 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9101 if (!pmu
->pmu_cpu_context
)
9104 for_each_possible_cpu(cpu
) {
9105 struct perf_cpu_context
*cpuctx
;
9107 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9108 __perf_event_init_context(&cpuctx
->ctx
);
9109 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9110 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9111 cpuctx
->ctx
.pmu
= pmu
;
9112 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9114 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9118 if (!pmu
->start_txn
) {
9119 if (pmu
->pmu_enable
) {
9121 * If we have pmu_enable/pmu_disable calls, install
9122 * transaction stubs that use that to try and batch
9123 * hardware accesses.
9125 pmu
->start_txn
= perf_pmu_start_txn
;
9126 pmu
->commit_txn
= perf_pmu_commit_txn
;
9127 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9129 pmu
->start_txn
= perf_pmu_nop_txn
;
9130 pmu
->commit_txn
= perf_pmu_nop_int
;
9131 pmu
->cancel_txn
= perf_pmu_nop_void
;
9135 if (!pmu
->pmu_enable
) {
9136 pmu
->pmu_enable
= perf_pmu_nop_void
;
9137 pmu
->pmu_disable
= perf_pmu_nop_void
;
9140 if (!pmu
->event_idx
)
9141 pmu
->event_idx
= perf_event_idx_default
;
9143 list_add_rcu(&pmu
->entry
, &pmus
);
9144 atomic_set(&pmu
->exclusive_cnt
, 0);
9147 mutex_unlock(&pmus_lock
);
9152 device_del(pmu
->dev
);
9153 put_device(pmu
->dev
);
9156 if (pmu
->type
>= PERF_TYPE_MAX
)
9157 idr_remove(&pmu_idr
, pmu
->type
);
9160 free_percpu(pmu
->pmu_disable_count
);
9163 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9165 void perf_pmu_unregister(struct pmu
*pmu
)
9169 mutex_lock(&pmus_lock
);
9170 remove_device
= pmu_bus_running
;
9171 list_del_rcu(&pmu
->entry
);
9172 mutex_unlock(&pmus_lock
);
9175 * We dereference the pmu list under both SRCU and regular RCU, so
9176 * synchronize against both of those.
9178 synchronize_srcu(&pmus_srcu
);
9181 free_percpu(pmu
->pmu_disable_count
);
9182 if (pmu
->type
>= PERF_TYPE_MAX
)
9183 idr_remove(&pmu_idr
, pmu
->type
);
9184 if (remove_device
) {
9185 if (pmu
->nr_addr_filters
)
9186 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9187 device_del(pmu
->dev
);
9188 put_device(pmu
->dev
);
9190 free_pmu_context(pmu
);
9192 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9194 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9196 struct perf_event_context
*ctx
= NULL
;
9199 if (!try_module_get(pmu
->module
))
9203 * A number of pmu->event_init() methods iterate the sibling_list to,
9204 * for example, validate if the group fits on the PMU. Therefore,
9205 * if this is a sibling event, acquire the ctx->mutex to protect
9208 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
9210 * This ctx->mutex can nest when we're called through
9211 * inheritance. See the perf_event_ctx_lock_nested() comment.
9213 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9214 SINGLE_DEPTH_NESTING
);
9219 ret
= pmu
->event_init(event
);
9222 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9225 module_put(pmu
->module
);
9230 static struct pmu
*perf_init_event(struct perf_event
*event
)
9236 idx
= srcu_read_lock(&pmus_srcu
);
9238 /* Try parent's PMU first: */
9239 if (event
->parent
&& event
->parent
->pmu
) {
9240 pmu
= event
->parent
->pmu
;
9241 ret
= perf_try_init_event(pmu
, event
);
9247 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9250 ret
= perf_try_init_event(pmu
, event
);
9256 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9257 ret
= perf_try_init_event(pmu
, event
);
9261 if (ret
!= -ENOENT
) {
9266 pmu
= ERR_PTR(-ENOENT
);
9268 srcu_read_unlock(&pmus_srcu
, idx
);
9273 static void attach_sb_event(struct perf_event
*event
)
9275 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9277 raw_spin_lock(&pel
->lock
);
9278 list_add_rcu(&event
->sb_list
, &pel
->list
);
9279 raw_spin_unlock(&pel
->lock
);
9283 * We keep a list of all !task (and therefore per-cpu) events
9284 * that need to receive side-band records.
9286 * This avoids having to scan all the various PMU per-cpu contexts
9289 static void account_pmu_sb_event(struct perf_event
*event
)
9291 if (is_sb_event(event
))
9292 attach_sb_event(event
);
9295 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9300 if (is_cgroup_event(event
))
9301 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9304 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9305 static void account_freq_event_nohz(void)
9307 #ifdef CONFIG_NO_HZ_FULL
9308 /* Lock so we don't race with concurrent unaccount */
9309 spin_lock(&nr_freq_lock
);
9310 if (atomic_inc_return(&nr_freq_events
) == 1)
9311 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9312 spin_unlock(&nr_freq_lock
);
9316 static void account_freq_event(void)
9318 if (tick_nohz_full_enabled())
9319 account_freq_event_nohz();
9321 atomic_inc(&nr_freq_events
);
9325 static void account_event(struct perf_event
*event
)
9332 if (event
->attach_state
& PERF_ATTACH_TASK
)
9334 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9335 atomic_inc(&nr_mmap_events
);
9336 if (event
->attr
.comm
)
9337 atomic_inc(&nr_comm_events
);
9338 if (event
->attr
.namespaces
)
9339 atomic_inc(&nr_namespaces_events
);
9340 if (event
->attr
.task
)
9341 atomic_inc(&nr_task_events
);
9342 if (event
->attr
.freq
)
9343 account_freq_event();
9344 if (event
->attr
.context_switch
) {
9345 atomic_inc(&nr_switch_events
);
9348 if (has_branch_stack(event
))
9350 if (is_cgroup_event(event
))
9355 * We need the mutex here because static_branch_enable()
9356 * must complete *before* the perf_sched_count increment
9359 if (atomic_inc_not_zero(&perf_sched_count
))
9362 mutex_lock(&perf_sched_mutex
);
9363 if (!atomic_read(&perf_sched_count
)) {
9364 static_branch_enable(&perf_sched_events
);
9366 * Guarantee that all CPUs observe they key change and
9367 * call the perf scheduling hooks before proceeding to
9368 * install events that need them.
9370 synchronize_sched();
9373 * Now that we have waited for the sync_sched(), allow further
9374 * increments to by-pass the mutex.
9376 atomic_inc(&perf_sched_count
);
9377 mutex_unlock(&perf_sched_mutex
);
9381 account_event_cpu(event
, event
->cpu
);
9383 account_pmu_sb_event(event
);
9387 * Allocate and initialize a event structure
9389 static struct perf_event
*
9390 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9391 struct task_struct
*task
,
9392 struct perf_event
*group_leader
,
9393 struct perf_event
*parent_event
,
9394 perf_overflow_handler_t overflow_handler
,
9395 void *context
, int cgroup_fd
)
9398 struct perf_event
*event
;
9399 struct hw_perf_event
*hwc
;
9402 if ((unsigned)cpu
>= nr_cpu_ids
) {
9403 if (!task
|| cpu
!= -1)
9404 return ERR_PTR(-EINVAL
);
9407 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9409 return ERR_PTR(-ENOMEM
);
9412 * Single events are their own group leaders, with an
9413 * empty sibling list:
9416 group_leader
= event
;
9418 mutex_init(&event
->child_mutex
);
9419 INIT_LIST_HEAD(&event
->child_list
);
9421 INIT_LIST_HEAD(&event
->group_entry
);
9422 INIT_LIST_HEAD(&event
->event_entry
);
9423 INIT_LIST_HEAD(&event
->sibling_list
);
9424 INIT_LIST_HEAD(&event
->rb_entry
);
9425 INIT_LIST_HEAD(&event
->active_entry
);
9426 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9427 INIT_HLIST_NODE(&event
->hlist_entry
);
9430 init_waitqueue_head(&event
->waitq
);
9431 init_irq_work(&event
->pending
, perf_pending_event
);
9433 mutex_init(&event
->mmap_mutex
);
9434 raw_spin_lock_init(&event
->addr_filters
.lock
);
9436 atomic_long_set(&event
->refcount
, 1);
9438 event
->attr
= *attr
;
9439 event
->group_leader
= group_leader
;
9443 event
->parent
= parent_event
;
9445 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9446 event
->id
= atomic64_inc_return(&perf_event_id
);
9448 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9451 event
->attach_state
= PERF_ATTACH_TASK
;
9453 * XXX pmu::event_init needs to know what task to account to
9454 * and we cannot use the ctx information because we need the
9455 * pmu before we get a ctx.
9457 event
->hw
.target
= task
;
9460 event
->clock
= &local_clock
;
9462 event
->clock
= parent_event
->clock
;
9464 if (!overflow_handler
&& parent_event
) {
9465 overflow_handler
= parent_event
->overflow_handler
;
9466 context
= parent_event
->overflow_handler_context
;
9467 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9468 if (overflow_handler
== bpf_overflow_handler
) {
9469 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9472 err
= PTR_ERR(prog
);
9476 event
->orig_overflow_handler
=
9477 parent_event
->orig_overflow_handler
;
9482 if (overflow_handler
) {
9483 event
->overflow_handler
= overflow_handler
;
9484 event
->overflow_handler_context
= context
;
9485 } else if (is_write_backward(event
)){
9486 event
->overflow_handler
= perf_event_output_backward
;
9487 event
->overflow_handler_context
= NULL
;
9489 event
->overflow_handler
= perf_event_output_forward
;
9490 event
->overflow_handler_context
= NULL
;
9493 perf_event__state_init(event
);
9498 hwc
->sample_period
= attr
->sample_period
;
9499 if (attr
->freq
&& attr
->sample_freq
)
9500 hwc
->sample_period
= 1;
9501 hwc
->last_period
= hwc
->sample_period
;
9503 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9506 * We currently do not support PERF_SAMPLE_READ on inherited events.
9507 * See perf_output_read().
9509 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9512 if (!has_branch_stack(event
))
9513 event
->attr
.branch_sample_type
= 0;
9515 if (cgroup_fd
!= -1) {
9516 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9521 pmu
= perf_init_event(event
);
9527 err
= exclusive_event_init(event
);
9531 if (has_addr_filter(event
)) {
9532 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9533 sizeof(unsigned long),
9535 if (!event
->addr_filters_offs
) {
9540 /* force hw sync on the address filters */
9541 event
->addr_filters_gen
= 1;
9544 if (!event
->parent
) {
9545 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9546 err
= get_callchain_buffers(attr
->sample_max_stack
);
9548 goto err_addr_filters
;
9552 /* symmetric to unaccount_event() in _free_event() */
9553 account_event(event
);
9558 kfree(event
->addr_filters_offs
);
9561 exclusive_event_destroy(event
);
9565 event
->destroy(event
);
9566 module_put(pmu
->module
);
9568 if (is_cgroup_event(event
))
9569 perf_detach_cgroup(event
);
9571 put_pid_ns(event
->ns
);
9574 return ERR_PTR(err
);
9577 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9578 struct perf_event_attr
*attr
)
9583 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9587 * zero the full structure, so that a short copy will be nice.
9589 memset(attr
, 0, sizeof(*attr
));
9591 ret
= get_user(size
, &uattr
->size
);
9595 if (size
> PAGE_SIZE
) /* silly large */
9598 if (!size
) /* abi compat */
9599 size
= PERF_ATTR_SIZE_VER0
;
9601 if (size
< PERF_ATTR_SIZE_VER0
)
9605 * If we're handed a bigger struct than we know of,
9606 * ensure all the unknown bits are 0 - i.e. new
9607 * user-space does not rely on any kernel feature
9608 * extensions we dont know about yet.
9610 if (size
> sizeof(*attr
)) {
9611 unsigned char __user
*addr
;
9612 unsigned char __user
*end
;
9615 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9616 end
= (void __user
*)uattr
+ size
;
9618 for (; addr
< end
; addr
++) {
9619 ret
= get_user(val
, addr
);
9625 size
= sizeof(*attr
);
9628 ret
= copy_from_user(attr
, uattr
, size
);
9634 if (attr
->__reserved_1
)
9637 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9640 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9643 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9644 u64 mask
= attr
->branch_sample_type
;
9646 /* only using defined bits */
9647 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9650 /* at least one branch bit must be set */
9651 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9654 /* propagate priv level, when not set for branch */
9655 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9657 /* exclude_kernel checked on syscall entry */
9658 if (!attr
->exclude_kernel
)
9659 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9661 if (!attr
->exclude_user
)
9662 mask
|= PERF_SAMPLE_BRANCH_USER
;
9664 if (!attr
->exclude_hv
)
9665 mask
|= PERF_SAMPLE_BRANCH_HV
;
9667 * adjust user setting (for HW filter setup)
9669 attr
->branch_sample_type
= mask
;
9671 /* privileged levels capture (kernel, hv): check permissions */
9672 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9673 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9677 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9678 ret
= perf_reg_validate(attr
->sample_regs_user
);
9683 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9684 if (!arch_perf_have_user_stack_dump())
9688 * We have __u32 type for the size, but so far
9689 * we can only use __u16 as maximum due to the
9690 * __u16 sample size limit.
9692 if (attr
->sample_stack_user
>= USHRT_MAX
)
9694 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9698 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9699 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9704 put_user(sizeof(*attr
), &uattr
->size
);
9710 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9712 struct ring_buffer
*rb
= NULL
;
9718 /* don't allow circular references */
9719 if (event
== output_event
)
9723 * Don't allow cross-cpu buffers
9725 if (output_event
->cpu
!= event
->cpu
)
9729 * If its not a per-cpu rb, it must be the same task.
9731 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9735 * Mixing clocks in the same buffer is trouble you don't need.
9737 if (output_event
->clock
!= event
->clock
)
9741 * Either writing ring buffer from beginning or from end.
9742 * Mixing is not allowed.
9744 if (is_write_backward(output_event
) != is_write_backward(event
))
9748 * If both events generate aux data, they must be on the same PMU
9750 if (has_aux(event
) && has_aux(output_event
) &&
9751 event
->pmu
!= output_event
->pmu
)
9755 mutex_lock(&event
->mmap_mutex
);
9756 /* Can't redirect output if we've got an active mmap() */
9757 if (atomic_read(&event
->mmap_count
))
9761 /* get the rb we want to redirect to */
9762 rb
= ring_buffer_get(output_event
);
9767 ring_buffer_attach(event
, rb
);
9771 mutex_unlock(&event
->mmap_mutex
);
9777 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9783 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9786 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9788 bool nmi_safe
= false;
9791 case CLOCK_MONOTONIC
:
9792 event
->clock
= &ktime_get_mono_fast_ns
;
9796 case CLOCK_MONOTONIC_RAW
:
9797 event
->clock
= &ktime_get_raw_fast_ns
;
9801 case CLOCK_REALTIME
:
9802 event
->clock
= &ktime_get_real_ns
;
9805 case CLOCK_BOOTTIME
:
9806 event
->clock
= &ktime_get_boot_ns
;
9810 event
->clock
= &ktime_get_tai_ns
;
9817 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9824 * Variation on perf_event_ctx_lock_nested(), except we take two context
9827 static struct perf_event_context
*
9828 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9829 struct perf_event_context
*ctx
)
9831 struct perf_event_context
*gctx
;
9835 gctx
= READ_ONCE(group_leader
->ctx
);
9836 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9842 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9844 if (group_leader
->ctx
!= gctx
) {
9845 mutex_unlock(&ctx
->mutex
);
9846 mutex_unlock(&gctx
->mutex
);
9855 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9857 * @attr_uptr: event_id type attributes for monitoring/sampling
9860 * @group_fd: group leader event fd
9862 SYSCALL_DEFINE5(perf_event_open
,
9863 struct perf_event_attr __user
*, attr_uptr
,
9864 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9866 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9867 struct perf_event
*event
, *sibling
;
9868 struct perf_event_attr attr
;
9869 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9870 struct file
*event_file
= NULL
;
9871 struct fd group
= {NULL
, 0};
9872 struct task_struct
*task
= NULL
;
9877 int f_flags
= O_RDWR
;
9880 /* for future expandability... */
9881 if (flags
& ~PERF_FLAG_ALL
)
9884 err
= perf_copy_attr(attr_uptr
, &attr
);
9888 if (!attr
.exclude_kernel
) {
9889 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9893 if (attr
.namespaces
) {
9894 if (!capable(CAP_SYS_ADMIN
))
9899 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9902 if (attr
.sample_period
& (1ULL << 63))
9906 /* Only privileged users can get physical addresses */
9907 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
9908 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9911 if (!attr
.sample_max_stack
)
9912 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9915 * In cgroup mode, the pid argument is used to pass the fd
9916 * opened to the cgroup directory in cgroupfs. The cpu argument
9917 * designates the cpu on which to monitor threads from that
9920 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9923 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9924 f_flags
|= O_CLOEXEC
;
9926 event_fd
= get_unused_fd_flags(f_flags
);
9930 if (group_fd
!= -1) {
9931 err
= perf_fget_light(group_fd
, &group
);
9934 group_leader
= group
.file
->private_data
;
9935 if (flags
& PERF_FLAG_FD_OUTPUT
)
9936 output_event
= group_leader
;
9937 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9938 group_leader
= NULL
;
9941 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9942 task
= find_lively_task_by_vpid(pid
);
9944 err
= PTR_ERR(task
);
9949 if (task
&& group_leader
&&
9950 group_leader
->attr
.inherit
!= attr
.inherit
) {
9956 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9961 * Reuse ptrace permission checks for now.
9963 * We must hold cred_guard_mutex across this and any potential
9964 * perf_install_in_context() call for this new event to
9965 * serialize against exec() altering our credentials (and the
9966 * perf_event_exit_task() that could imply).
9969 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9973 if (flags
& PERF_FLAG_PID_CGROUP
)
9976 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9977 NULL
, NULL
, cgroup_fd
);
9978 if (IS_ERR(event
)) {
9979 err
= PTR_ERR(event
);
9983 if (is_sampling_event(event
)) {
9984 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9991 * Special case software events and allow them to be part of
9992 * any hardware group.
9996 if (attr
.use_clockid
) {
9997 err
= perf_event_set_clock(event
, attr
.clockid
);
10002 if (pmu
->task_ctx_nr
== perf_sw_context
)
10003 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
10005 if (group_leader
&&
10006 (is_software_event(event
) != is_software_event(group_leader
))) {
10007 if (is_software_event(event
)) {
10009 * If event and group_leader are not both a software
10010 * event, and event is, then group leader is not.
10012 * Allow the addition of software events to !software
10013 * groups, this is safe because software events never
10014 * fail to schedule.
10016 pmu
= group_leader
->pmu
;
10017 } else if (is_software_event(group_leader
) &&
10018 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10020 * In case the group is a pure software group, and we
10021 * try to add a hardware event, move the whole group to
10022 * the hardware context.
10029 * Get the target context (task or percpu):
10031 ctx
= find_get_context(pmu
, task
, event
);
10033 err
= PTR_ERR(ctx
);
10037 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10043 * Look up the group leader (we will attach this event to it):
10045 if (group_leader
) {
10049 * Do not allow a recursive hierarchy (this new sibling
10050 * becoming part of another group-sibling):
10052 if (group_leader
->group_leader
!= group_leader
)
10055 /* All events in a group should have the same clock */
10056 if (group_leader
->clock
!= event
->clock
)
10060 * Make sure we're both events for the same CPU;
10061 * grouping events for different CPUs is broken; since
10062 * you can never concurrently schedule them anyhow.
10064 if (group_leader
->cpu
!= event
->cpu
)
10068 * Make sure we're both on the same task, or both
10071 if (group_leader
->ctx
->task
!= ctx
->task
)
10075 * Do not allow to attach to a group in a different task
10076 * or CPU context. If we're moving SW events, we'll fix
10077 * this up later, so allow that.
10079 if (!move_group
&& group_leader
->ctx
!= ctx
)
10083 * Only a group leader can be exclusive or pinned
10085 if (attr
.exclusive
|| attr
.pinned
)
10089 if (output_event
) {
10090 err
= perf_event_set_output(event
, output_event
);
10095 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10097 if (IS_ERR(event_file
)) {
10098 err
= PTR_ERR(event_file
);
10104 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10106 if (gctx
->task
== TASK_TOMBSTONE
) {
10112 * Check if we raced against another sys_perf_event_open() call
10113 * moving the software group underneath us.
10115 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10117 * If someone moved the group out from under us, check
10118 * if this new event wound up on the same ctx, if so
10119 * its the regular !move_group case, otherwise fail.
10125 perf_event_ctx_unlock(group_leader
, gctx
);
10130 mutex_lock(&ctx
->mutex
);
10133 if (ctx
->task
== TASK_TOMBSTONE
) {
10138 if (!perf_event_validate_size(event
)) {
10145 * Check if the @cpu we're creating an event for is online.
10147 * We use the perf_cpu_context::ctx::mutex to serialize against
10148 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10150 struct perf_cpu_context
*cpuctx
=
10151 container_of(ctx
, struct perf_cpu_context
, ctx
);
10153 if (!cpuctx
->online
) {
10161 * Must be under the same ctx::mutex as perf_install_in_context(),
10162 * because we need to serialize with concurrent event creation.
10164 if (!exclusive_event_installable(event
, ctx
)) {
10165 /* exclusive and group stuff are assumed mutually exclusive */
10166 WARN_ON_ONCE(move_group
);
10172 WARN_ON_ONCE(ctx
->parent_ctx
);
10175 * This is the point on no return; we cannot fail hereafter. This is
10176 * where we start modifying current state.
10181 * See perf_event_ctx_lock() for comments on the details
10182 * of swizzling perf_event::ctx.
10184 perf_remove_from_context(group_leader
, 0);
10187 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10189 perf_remove_from_context(sibling
, 0);
10194 * Wait for everybody to stop referencing the events through
10195 * the old lists, before installing it on new lists.
10200 * Install the group siblings before the group leader.
10202 * Because a group leader will try and install the entire group
10203 * (through the sibling list, which is still in-tact), we can
10204 * end up with siblings installed in the wrong context.
10206 * By installing siblings first we NO-OP because they're not
10207 * reachable through the group lists.
10209 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10211 perf_event__state_init(sibling
);
10212 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10217 * Removing from the context ends up with disabled
10218 * event. What we want here is event in the initial
10219 * startup state, ready to be add into new context.
10221 perf_event__state_init(group_leader
);
10222 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10227 * Precalculate sample_data sizes; do while holding ctx::mutex such
10228 * that we're serialized against further additions and before
10229 * perf_install_in_context() which is the point the event is active and
10230 * can use these values.
10232 perf_event__header_size(event
);
10233 perf_event__id_header_size(event
);
10235 event
->owner
= current
;
10237 perf_install_in_context(ctx
, event
, event
->cpu
);
10238 perf_unpin_context(ctx
);
10241 perf_event_ctx_unlock(group_leader
, gctx
);
10242 mutex_unlock(&ctx
->mutex
);
10245 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10246 put_task_struct(task
);
10249 mutex_lock(¤t
->perf_event_mutex
);
10250 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10251 mutex_unlock(¤t
->perf_event_mutex
);
10254 * Drop the reference on the group_event after placing the
10255 * new event on the sibling_list. This ensures destruction
10256 * of the group leader will find the pointer to itself in
10257 * perf_group_detach().
10260 fd_install(event_fd
, event_file
);
10265 perf_event_ctx_unlock(group_leader
, gctx
);
10266 mutex_unlock(&ctx
->mutex
);
10270 perf_unpin_context(ctx
);
10274 * If event_file is set, the fput() above will have called ->release()
10275 * and that will take care of freeing the event.
10281 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10284 put_task_struct(task
);
10288 put_unused_fd(event_fd
);
10293 * perf_event_create_kernel_counter
10295 * @attr: attributes of the counter to create
10296 * @cpu: cpu in which the counter is bound
10297 * @task: task to profile (NULL for percpu)
10299 struct perf_event
*
10300 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10301 struct task_struct
*task
,
10302 perf_overflow_handler_t overflow_handler
,
10305 struct perf_event_context
*ctx
;
10306 struct perf_event
*event
;
10310 * Get the target context (task or percpu):
10313 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10314 overflow_handler
, context
, -1);
10315 if (IS_ERR(event
)) {
10316 err
= PTR_ERR(event
);
10320 /* Mark owner so we could distinguish it from user events. */
10321 event
->owner
= TASK_TOMBSTONE
;
10323 ctx
= find_get_context(event
->pmu
, task
, event
);
10325 err
= PTR_ERR(ctx
);
10329 WARN_ON_ONCE(ctx
->parent_ctx
);
10330 mutex_lock(&ctx
->mutex
);
10331 if (ctx
->task
== TASK_TOMBSTONE
) {
10338 * Check if the @cpu we're creating an event for is online.
10340 * We use the perf_cpu_context::ctx::mutex to serialize against
10341 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10343 struct perf_cpu_context
*cpuctx
=
10344 container_of(ctx
, struct perf_cpu_context
, ctx
);
10345 if (!cpuctx
->online
) {
10351 if (!exclusive_event_installable(event
, ctx
)) {
10356 perf_install_in_context(ctx
, event
, cpu
);
10357 perf_unpin_context(ctx
);
10358 mutex_unlock(&ctx
->mutex
);
10363 mutex_unlock(&ctx
->mutex
);
10364 perf_unpin_context(ctx
);
10369 return ERR_PTR(err
);
10371 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10373 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10375 struct perf_event_context
*src_ctx
;
10376 struct perf_event_context
*dst_ctx
;
10377 struct perf_event
*event
, *tmp
;
10380 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10381 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10384 * See perf_event_ctx_lock() for comments on the details
10385 * of swizzling perf_event::ctx.
10387 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10388 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10390 perf_remove_from_context(event
, 0);
10391 unaccount_event_cpu(event
, src_cpu
);
10393 list_add(&event
->migrate_entry
, &events
);
10397 * Wait for the events to quiesce before re-instating them.
10402 * Re-instate events in 2 passes.
10404 * Skip over group leaders and only install siblings on this first
10405 * pass, siblings will not get enabled without a leader, however a
10406 * leader will enable its siblings, even if those are still on the old
10409 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10410 if (event
->group_leader
== event
)
10413 list_del(&event
->migrate_entry
);
10414 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10415 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10416 account_event_cpu(event
, dst_cpu
);
10417 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10422 * Once all the siblings are setup properly, install the group leaders
10425 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10426 list_del(&event
->migrate_entry
);
10427 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10428 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10429 account_event_cpu(event
, dst_cpu
);
10430 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10433 mutex_unlock(&dst_ctx
->mutex
);
10434 mutex_unlock(&src_ctx
->mutex
);
10436 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10438 static void sync_child_event(struct perf_event
*child_event
,
10439 struct task_struct
*child
)
10441 struct perf_event
*parent_event
= child_event
->parent
;
10444 if (child_event
->attr
.inherit_stat
)
10445 perf_event_read_event(child_event
, child
);
10447 child_val
= perf_event_count(child_event
);
10450 * Add back the child's count to the parent's count:
10452 atomic64_add(child_val
, &parent_event
->child_count
);
10453 atomic64_add(child_event
->total_time_enabled
,
10454 &parent_event
->child_total_time_enabled
);
10455 atomic64_add(child_event
->total_time_running
,
10456 &parent_event
->child_total_time_running
);
10460 perf_event_exit_event(struct perf_event
*child_event
,
10461 struct perf_event_context
*child_ctx
,
10462 struct task_struct
*child
)
10464 struct perf_event
*parent_event
= child_event
->parent
;
10467 * Do not destroy the 'original' grouping; because of the context
10468 * switch optimization the original events could've ended up in a
10469 * random child task.
10471 * If we were to destroy the original group, all group related
10472 * operations would cease to function properly after this random
10475 * Do destroy all inherited groups, we don't care about those
10476 * and being thorough is better.
10478 raw_spin_lock_irq(&child_ctx
->lock
);
10479 WARN_ON_ONCE(child_ctx
->is_active
);
10482 perf_group_detach(child_event
);
10483 list_del_event(child_event
, child_ctx
);
10484 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
10485 raw_spin_unlock_irq(&child_ctx
->lock
);
10488 * Parent events are governed by their filedesc, retain them.
10490 if (!parent_event
) {
10491 perf_event_wakeup(child_event
);
10495 * Child events can be cleaned up.
10498 sync_child_event(child_event
, child
);
10501 * Remove this event from the parent's list
10503 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10504 mutex_lock(&parent_event
->child_mutex
);
10505 list_del_init(&child_event
->child_list
);
10506 mutex_unlock(&parent_event
->child_mutex
);
10509 * Kick perf_poll() for is_event_hup().
10511 perf_event_wakeup(parent_event
);
10512 free_event(child_event
);
10513 put_event(parent_event
);
10516 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10518 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10519 struct perf_event
*child_event
, *next
;
10521 WARN_ON_ONCE(child
!= current
);
10523 child_ctx
= perf_pin_task_context(child
, ctxn
);
10528 * In order to reduce the amount of tricky in ctx tear-down, we hold
10529 * ctx::mutex over the entire thing. This serializes against almost
10530 * everything that wants to access the ctx.
10532 * The exception is sys_perf_event_open() /
10533 * perf_event_create_kernel_count() which does find_get_context()
10534 * without ctx::mutex (it cannot because of the move_group double mutex
10535 * lock thing). See the comments in perf_install_in_context().
10537 mutex_lock(&child_ctx
->mutex
);
10540 * In a single ctx::lock section, de-schedule the events and detach the
10541 * context from the task such that we cannot ever get it scheduled back
10544 raw_spin_lock_irq(&child_ctx
->lock
);
10545 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10548 * Now that the context is inactive, destroy the task <-> ctx relation
10549 * and mark the context dead.
10551 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10552 put_ctx(child_ctx
); /* cannot be last */
10553 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10554 put_task_struct(current
); /* cannot be last */
10556 clone_ctx
= unclone_ctx(child_ctx
);
10557 raw_spin_unlock_irq(&child_ctx
->lock
);
10560 put_ctx(clone_ctx
);
10563 * Report the task dead after unscheduling the events so that we
10564 * won't get any samples after PERF_RECORD_EXIT. We can however still
10565 * get a few PERF_RECORD_READ events.
10567 perf_event_task(child
, child_ctx
, 0);
10569 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10570 perf_event_exit_event(child_event
, child_ctx
, child
);
10572 mutex_unlock(&child_ctx
->mutex
);
10574 put_ctx(child_ctx
);
10578 * When a child task exits, feed back event values to parent events.
10580 * Can be called with cred_guard_mutex held when called from
10581 * install_exec_creds().
10583 void perf_event_exit_task(struct task_struct
*child
)
10585 struct perf_event
*event
, *tmp
;
10588 mutex_lock(&child
->perf_event_mutex
);
10589 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10591 list_del_init(&event
->owner_entry
);
10594 * Ensure the list deletion is visible before we clear
10595 * the owner, closes a race against perf_release() where
10596 * we need to serialize on the owner->perf_event_mutex.
10598 smp_store_release(&event
->owner
, NULL
);
10600 mutex_unlock(&child
->perf_event_mutex
);
10602 for_each_task_context_nr(ctxn
)
10603 perf_event_exit_task_context(child
, ctxn
);
10606 * The perf_event_exit_task_context calls perf_event_task
10607 * with child's task_ctx, which generates EXIT events for
10608 * child contexts and sets child->perf_event_ctxp[] to NULL.
10609 * At this point we need to send EXIT events to cpu contexts.
10611 perf_event_task(child
, NULL
, 0);
10614 static void perf_free_event(struct perf_event
*event
,
10615 struct perf_event_context
*ctx
)
10617 struct perf_event
*parent
= event
->parent
;
10619 if (WARN_ON_ONCE(!parent
))
10622 mutex_lock(&parent
->child_mutex
);
10623 list_del_init(&event
->child_list
);
10624 mutex_unlock(&parent
->child_mutex
);
10628 raw_spin_lock_irq(&ctx
->lock
);
10629 perf_group_detach(event
);
10630 list_del_event(event
, ctx
);
10631 raw_spin_unlock_irq(&ctx
->lock
);
10636 * Free an unexposed, unused context as created by inheritance by
10637 * perf_event_init_task below, used by fork() in case of fail.
10639 * Not all locks are strictly required, but take them anyway to be nice and
10640 * help out with the lockdep assertions.
10642 void perf_event_free_task(struct task_struct
*task
)
10644 struct perf_event_context
*ctx
;
10645 struct perf_event
*event
, *tmp
;
10648 for_each_task_context_nr(ctxn
) {
10649 ctx
= task
->perf_event_ctxp
[ctxn
];
10653 mutex_lock(&ctx
->mutex
);
10654 raw_spin_lock_irq(&ctx
->lock
);
10656 * Destroy the task <-> ctx relation and mark the context dead.
10658 * This is important because even though the task hasn't been
10659 * exposed yet the context has been (through child_list).
10661 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10662 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10663 put_task_struct(task
); /* cannot be last */
10664 raw_spin_unlock_irq(&ctx
->lock
);
10666 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10667 perf_free_event(event
, ctx
);
10669 mutex_unlock(&ctx
->mutex
);
10674 void perf_event_delayed_put(struct task_struct
*task
)
10678 for_each_task_context_nr(ctxn
)
10679 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10682 struct file
*perf_event_get(unsigned int fd
)
10686 file
= fget_raw(fd
);
10688 return ERR_PTR(-EBADF
);
10690 if (file
->f_op
!= &perf_fops
) {
10692 return ERR_PTR(-EBADF
);
10698 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10701 return ERR_PTR(-EINVAL
);
10703 return &event
->attr
;
10707 * Inherit a event from parent task to child task.
10710 * - valid pointer on success
10711 * - NULL for orphaned events
10712 * - IS_ERR() on error
10714 static struct perf_event
*
10715 inherit_event(struct perf_event
*parent_event
,
10716 struct task_struct
*parent
,
10717 struct perf_event_context
*parent_ctx
,
10718 struct task_struct
*child
,
10719 struct perf_event
*group_leader
,
10720 struct perf_event_context
*child_ctx
)
10722 enum perf_event_state parent_state
= parent_event
->state
;
10723 struct perf_event
*child_event
;
10724 unsigned long flags
;
10727 * Instead of creating recursive hierarchies of events,
10728 * we link inherited events back to the original parent,
10729 * which has a filp for sure, which we use as the reference
10732 if (parent_event
->parent
)
10733 parent_event
= parent_event
->parent
;
10735 child_event
= perf_event_alloc(&parent_event
->attr
,
10738 group_leader
, parent_event
,
10740 if (IS_ERR(child_event
))
10741 return child_event
;
10744 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10745 * must be under the same lock in order to serialize against
10746 * perf_event_release_kernel(), such that either we must observe
10747 * is_orphaned_event() or they will observe us on the child_list.
10749 mutex_lock(&parent_event
->child_mutex
);
10750 if (is_orphaned_event(parent_event
) ||
10751 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10752 mutex_unlock(&parent_event
->child_mutex
);
10753 free_event(child_event
);
10757 get_ctx(child_ctx
);
10760 * Make the child state follow the state of the parent event,
10761 * not its attr.disabled bit. We hold the parent's mutex,
10762 * so we won't race with perf_event_{en, dis}able_family.
10764 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10765 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10767 child_event
->state
= PERF_EVENT_STATE_OFF
;
10769 if (parent_event
->attr
.freq
) {
10770 u64 sample_period
= parent_event
->hw
.sample_period
;
10771 struct hw_perf_event
*hwc
= &child_event
->hw
;
10773 hwc
->sample_period
= sample_period
;
10774 hwc
->last_period
= sample_period
;
10776 local64_set(&hwc
->period_left
, sample_period
);
10779 child_event
->ctx
= child_ctx
;
10780 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10781 child_event
->overflow_handler_context
10782 = parent_event
->overflow_handler_context
;
10785 * Precalculate sample_data sizes
10787 perf_event__header_size(child_event
);
10788 perf_event__id_header_size(child_event
);
10791 * Link it up in the child's context:
10793 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10794 add_event_to_ctx(child_event
, child_ctx
);
10795 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10798 * Link this into the parent event's child list
10800 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10801 mutex_unlock(&parent_event
->child_mutex
);
10803 return child_event
;
10807 * Inherits an event group.
10809 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10810 * This matches with perf_event_release_kernel() removing all child events.
10816 static int inherit_group(struct perf_event
*parent_event
,
10817 struct task_struct
*parent
,
10818 struct perf_event_context
*parent_ctx
,
10819 struct task_struct
*child
,
10820 struct perf_event_context
*child_ctx
)
10822 struct perf_event
*leader
;
10823 struct perf_event
*sub
;
10824 struct perf_event
*child_ctr
;
10826 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10827 child
, NULL
, child_ctx
);
10828 if (IS_ERR(leader
))
10829 return PTR_ERR(leader
);
10831 * @leader can be NULL here because of is_orphaned_event(). In this
10832 * case inherit_event() will create individual events, similar to what
10833 * perf_group_detach() would do anyway.
10835 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10836 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10837 child
, leader
, child_ctx
);
10838 if (IS_ERR(child_ctr
))
10839 return PTR_ERR(child_ctr
);
10845 * Creates the child task context and tries to inherit the event-group.
10847 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10848 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10849 * consistent with perf_event_release_kernel() removing all child events.
10856 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10857 struct perf_event_context
*parent_ctx
,
10858 struct task_struct
*child
, int ctxn
,
10859 int *inherited_all
)
10862 struct perf_event_context
*child_ctx
;
10864 if (!event
->attr
.inherit
) {
10865 *inherited_all
= 0;
10869 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10872 * This is executed from the parent task context, so
10873 * inherit events that have been marked for cloning.
10874 * First allocate and initialize a context for the
10877 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10881 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10884 ret
= inherit_group(event
, parent
, parent_ctx
,
10888 *inherited_all
= 0;
10894 * Initialize the perf_event context in task_struct
10896 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10898 struct perf_event_context
*child_ctx
, *parent_ctx
;
10899 struct perf_event_context
*cloned_ctx
;
10900 struct perf_event
*event
;
10901 struct task_struct
*parent
= current
;
10902 int inherited_all
= 1;
10903 unsigned long flags
;
10906 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10910 * If the parent's context is a clone, pin it so it won't get
10911 * swapped under us.
10913 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10918 * No need to check if parent_ctx != NULL here; since we saw
10919 * it non-NULL earlier, the only reason for it to become NULL
10920 * is if we exit, and since we're currently in the middle of
10921 * a fork we can't be exiting at the same time.
10925 * Lock the parent list. No need to lock the child - not PID
10926 * hashed yet and not running, so nobody can access it.
10928 mutex_lock(&parent_ctx
->mutex
);
10931 * We dont have to disable NMIs - we are only looking at
10932 * the list, not manipulating it:
10934 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10935 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10936 child
, ctxn
, &inherited_all
);
10942 * We can't hold ctx->lock when iterating the ->flexible_group list due
10943 * to allocations, but we need to prevent rotation because
10944 * rotate_ctx() will change the list from interrupt context.
10946 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10947 parent_ctx
->rotate_disable
= 1;
10948 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10950 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10951 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10952 child
, ctxn
, &inherited_all
);
10957 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10958 parent_ctx
->rotate_disable
= 0;
10960 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10962 if (child_ctx
&& inherited_all
) {
10964 * Mark the child context as a clone of the parent
10965 * context, or of whatever the parent is a clone of.
10967 * Note that if the parent is a clone, the holding of
10968 * parent_ctx->lock avoids it from being uncloned.
10970 cloned_ctx
= parent_ctx
->parent_ctx
;
10972 child_ctx
->parent_ctx
= cloned_ctx
;
10973 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10975 child_ctx
->parent_ctx
= parent_ctx
;
10976 child_ctx
->parent_gen
= parent_ctx
->generation
;
10978 get_ctx(child_ctx
->parent_ctx
);
10981 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10983 mutex_unlock(&parent_ctx
->mutex
);
10985 perf_unpin_context(parent_ctx
);
10986 put_ctx(parent_ctx
);
10992 * Initialize the perf_event context in task_struct
10994 int perf_event_init_task(struct task_struct
*child
)
10998 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10999 mutex_init(&child
->perf_event_mutex
);
11000 INIT_LIST_HEAD(&child
->perf_event_list
);
11002 for_each_task_context_nr(ctxn
) {
11003 ret
= perf_event_init_context(child
, ctxn
);
11005 perf_event_free_task(child
);
11013 static void __init
perf_event_init_all_cpus(void)
11015 struct swevent_htable
*swhash
;
11018 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
11020 for_each_possible_cpu(cpu
) {
11021 swhash
= &per_cpu(swevent_htable
, cpu
);
11022 mutex_init(&swhash
->hlist_mutex
);
11023 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11025 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11026 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11028 #ifdef CONFIG_CGROUP_PERF
11029 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11031 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11035 void perf_swevent_init_cpu(unsigned int cpu
)
11037 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11039 mutex_lock(&swhash
->hlist_mutex
);
11040 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11041 struct swevent_hlist
*hlist
;
11043 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11045 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11047 mutex_unlock(&swhash
->hlist_mutex
);
11050 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11051 static void __perf_event_exit_context(void *__info
)
11053 struct perf_event_context
*ctx
= __info
;
11054 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11055 struct perf_event
*event
;
11057 raw_spin_lock(&ctx
->lock
);
11058 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
11059 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11060 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11061 raw_spin_unlock(&ctx
->lock
);
11064 static void perf_event_exit_cpu_context(int cpu
)
11066 struct perf_cpu_context
*cpuctx
;
11067 struct perf_event_context
*ctx
;
11070 mutex_lock(&pmus_lock
);
11071 list_for_each_entry(pmu
, &pmus
, entry
) {
11072 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11073 ctx
= &cpuctx
->ctx
;
11075 mutex_lock(&ctx
->mutex
);
11076 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11077 cpuctx
->online
= 0;
11078 mutex_unlock(&ctx
->mutex
);
11080 cpumask_clear_cpu(cpu
, perf_online_mask
);
11081 mutex_unlock(&pmus_lock
);
11085 static void perf_event_exit_cpu_context(int cpu
) { }
11089 int perf_event_init_cpu(unsigned int cpu
)
11091 struct perf_cpu_context
*cpuctx
;
11092 struct perf_event_context
*ctx
;
11095 perf_swevent_init_cpu(cpu
);
11097 mutex_lock(&pmus_lock
);
11098 cpumask_set_cpu(cpu
, perf_online_mask
);
11099 list_for_each_entry(pmu
, &pmus
, entry
) {
11100 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11101 ctx
= &cpuctx
->ctx
;
11103 mutex_lock(&ctx
->mutex
);
11104 cpuctx
->online
= 1;
11105 mutex_unlock(&ctx
->mutex
);
11107 mutex_unlock(&pmus_lock
);
11112 int perf_event_exit_cpu(unsigned int cpu
)
11114 perf_event_exit_cpu_context(cpu
);
11119 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11123 for_each_online_cpu(cpu
)
11124 perf_event_exit_cpu(cpu
);
11130 * Run the perf reboot notifier at the very last possible moment so that
11131 * the generic watchdog code runs as long as possible.
11133 static struct notifier_block perf_reboot_notifier
= {
11134 .notifier_call
= perf_reboot
,
11135 .priority
= INT_MIN
,
11138 void __init
perf_event_init(void)
11142 idr_init(&pmu_idr
);
11144 perf_event_init_all_cpus();
11145 init_srcu_struct(&pmus_srcu
);
11146 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11147 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11148 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11149 perf_tp_register();
11150 perf_event_init_cpu(smp_processor_id());
11151 register_reboot_notifier(&perf_reboot_notifier
);
11153 ret
= init_hw_breakpoint();
11154 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11157 * Build time assertion that we keep the data_head at the intended
11158 * location. IOW, validation we got the __reserved[] size right.
11160 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11164 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11167 struct perf_pmu_events_attr
*pmu_attr
=
11168 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11170 if (pmu_attr
->event_str
)
11171 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11175 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11177 static int __init
perf_event_sysfs_init(void)
11182 mutex_lock(&pmus_lock
);
11184 ret
= bus_register(&pmu_bus
);
11188 list_for_each_entry(pmu
, &pmus
, entry
) {
11189 if (!pmu
->name
|| pmu
->type
< 0)
11192 ret
= pmu_dev_alloc(pmu
);
11193 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11195 pmu_bus_running
= 1;
11199 mutex_unlock(&pmus_lock
);
11203 device_initcall(perf_event_sysfs_init
);
11205 #ifdef CONFIG_CGROUP_PERF
11206 static struct cgroup_subsys_state
*
11207 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11209 struct perf_cgroup
*jc
;
11211 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11213 return ERR_PTR(-ENOMEM
);
11215 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11218 return ERR_PTR(-ENOMEM
);
11224 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11226 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11228 free_percpu(jc
->info
);
11232 static int __perf_cgroup_move(void *info
)
11234 struct task_struct
*task
= info
;
11236 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11241 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11243 struct task_struct
*task
;
11244 struct cgroup_subsys_state
*css
;
11246 cgroup_taskset_for_each(task
, css
, tset
)
11247 task_function_call(task
, __perf_cgroup_move
, task
);
11250 struct cgroup_subsys perf_event_cgrp_subsys
= {
11251 .css_alloc
= perf_cgroup_css_alloc
,
11252 .css_free
= perf_cgroup_css_free
,
11253 .attach
= perf_cgroup_attach
,
11255 * Implicitly enable on dfl hierarchy so that perf events can
11256 * always be filtered by cgroup2 path as long as perf_event
11257 * controller is not mounted on a legacy hierarchy.
11259 .implicit_on_dfl
= true,
11262 #endif /* CONFIG_CGROUP_PERF */