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
1235 static struct perf_event_context
*
1236 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1238 struct perf_event_context
*ctx
;
1242 ctx
= READ_ONCE(event
->ctx
);
1243 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1249 mutex_lock_nested(&ctx
->mutex
, nesting
);
1250 if (event
->ctx
!= ctx
) {
1251 mutex_unlock(&ctx
->mutex
);
1259 static inline struct perf_event_context
*
1260 perf_event_ctx_lock(struct perf_event
*event
)
1262 return perf_event_ctx_lock_nested(event
, 0);
1265 static void perf_event_ctx_unlock(struct perf_event
*event
,
1266 struct perf_event_context
*ctx
)
1268 mutex_unlock(&ctx
->mutex
);
1273 * This must be done under the ctx->lock, such as to serialize against
1274 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1275 * calling scheduler related locks and ctx->lock nests inside those.
1277 static __must_check
struct perf_event_context
*
1278 unclone_ctx(struct perf_event_context
*ctx
)
1280 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1282 lockdep_assert_held(&ctx
->lock
);
1285 ctx
->parent_ctx
= NULL
;
1291 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1296 * only top level events have the pid namespace they were created in
1299 event
= event
->parent
;
1301 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1302 /* avoid -1 if it is idle thread or runs in another ns */
1303 if (!nr
&& !pid_alive(p
))
1308 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1310 return perf_event_pid_type(event
, p
, __PIDTYPE_TGID
);
1313 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1315 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1319 * If we inherit events we want to return the parent event id
1322 static u64
primary_event_id(struct perf_event
*event
)
1327 id
= event
->parent
->id
;
1333 * Get the perf_event_context for a task and lock it.
1335 * This has to cope with with the fact that until it is locked,
1336 * the context could get moved to another task.
1338 static struct perf_event_context
*
1339 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1341 struct perf_event_context
*ctx
;
1345 * One of the few rules of preemptible RCU is that one cannot do
1346 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1347 * part of the read side critical section was irqs-enabled -- see
1348 * rcu_read_unlock_special().
1350 * Since ctx->lock nests under rq->lock we must ensure the entire read
1351 * side critical section has interrupts disabled.
1353 local_irq_save(*flags
);
1355 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1358 * If this context is a clone of another, it might
1359 * get swapped for another underneath us by
1360 * perf_event_task_sched_out, though the
1361 * rcu_read_lock() protects us from any context
1362 * getting freed. Lock the context and check if it
1363 * got swapped before we could get the lock, and retry
1364 * if so. If we locked the right context, then it
1365 * can't get swapped on us any more.
1367 raw_spin_lock(&ctx
->lock
);
1368 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1369 raw_spin_unlock(&ctx
->lock
);
1371 local_irq_restore(*flags
);
1375 if (ctx
->task
== TASK_TOMBSTONE
||
1376 !atomic_inc_not_zero(&ctx
->refcount
)) {
1377 raw_spin_unlock(&ctx
->lock
);
1380 WARN_ON_ONCE(ctx
->task
!= task
);
1385 local_irq_restore(*flags
);
1390 * Get the context for a task and increment its pin_count so it
1391 * can't get swapped to another task. This also increments its
1392 * reference count so that the context can't get freed.
1394 static struct perf_event_context
*
1395 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1397 struct perf_event_context
*ctx
;
1398 unsigned long flags
;
1400 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1403 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1408 static void perf_unpin_context(struct perf_event_context
*ctx
)
1410 unsigned long flags
;
1412 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1414 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1418 * Update the record of the current time in a context.
1420 static void update_context_time(struct perf_event_context
*ctx
)
1422 u64 now
= perf_clock();
1424 ctx
->time
+= now
- ctx
->timestamp
;
1425 ctx
->timestamp
= now
;
1428 static u64
perf_event_time(struct perf_event
*event
)
1430 struct perf_event_context
*ctx
= event
->ctx
;
1432 if (is_cgroup_event(event
))
1433 return perf_cgroup_event_time(event
);
1435 return ctx
? ctx
->time
: 0;
1438 static enum event_type_t
get_event_type(struct perf_event
*event
)
1440 struct perf_event_context
*ctx
= event
->ctx
;
1441 enum event_type_t event_type
;
1443 lockdep_assert_held(&ctx
->lock
);
1446 * It's 'group type', really, because if our group leader is
1447 * pinned, so are we.
1449 if (event
->group_leader
!= event
)
1450 event
= event
->group_leader
;
1452 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1454 event_type
|= EVENT_CPU
;
1459 static struct list_head
*
1460 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1462 if (event
->attr
.pinned
)
1463 return &ctx
->pinned_groups
;
1465 return &ctx
->flexible_groups
;
1469 * Add a event from the lists for its context.
1470 * Must be called with ctx->mutex and ctx->lock held.
1473 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1475 lockdep_assert_held(&ctx
->lock
);
1477 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1478 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1480 event
->tstamp
= perf_event_time(event
);
1483 * If we're a stand alone event or group leader, we go to the context
1484 * list, group events are kept attached to the group so that
1485 * perf_group_detach can, at all times, locate all siblings.
1487 if (event
->group_leader
== event
) {
1488 struct list_head
*list
;
1490 event
->group_caps
= event
->event_caps
;
1492 list
= ctx_group_list(event
, ctx
);
1493 list_add_tail(&event
->group_entry
, list
);
1496 list_update_cgroup_event(event
, ctx
, true);
1498 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1500 if (event
->attr
.inherit_stat
)
1507 * Initialize event state based on the perf_event_attr::disabled.
1509 static inline void perf_event__state_init(struct perf_event
*event
)
1511 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1512 PERF_EVENT_STATE_INACTIVE
;
1515 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1517 int entry
= sizeof(u64
); /* value */
1521 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1522 size
+= sizeof(u64
);
1524 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1525 size
+= sizeof(u64
);
1527 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1528 entry
+= sizeof(u64
);
1530 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1532 size
+= sizeof(u64
);
1536 event
->read_size
= size
;
1539 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1541 struct perf_sample_data
*data
;
1544 if (sample_type
& PERF_SAMPLE_IP
)
1545 size
+= sizeof(data
->ip
);
1547 if (sample_type
& PERF_SAMPLE_ADDR
)
1548 size
+= sizeof(data
->addr
);
1550 if (sample_type
& PERF_SAMPLE_PERIOD
)
1551 size
+= sizeof(data
->period
);
1553 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1554 size
+= sizeof(data
->weight
);
1556 if (sample_type
& PERF_SAMPLE_READ
)
1557 size
+= event
->read_size
;
1559 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1560 size
+= sizeof(data
->data_src
.val
);
1562 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1563 size
+= sizeof(data
->txn
);
1565 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1566 size
+= sizeof(data
->phys_addr
);
1568 event
->header_size
= size
;
1572 * Called at perf_event creation and when events are attached/detached from a
1575 static void perf_event__header_size(struct perf_event
*event
)
1577 __perf_event_read_size(event
,
1578 event
->group_leader
->nr_siblings
);
1579 __perf_event_header_size(event
, event
->attr
.sample_type
);
1582 static void perf_event__id_header_size(struct perf_event
*event
)
1584 struct perf_sample_data
*data
;
1585 u64 sample_type
= event
->attr
.sample_type
;
1588 if (sample_type
& PERF_SAMPLE_TID
)
1589 size
+= sizeof(data
->tid_entry
);
1591 if (sample_type
& PERF_SAMPLE_TIME
)
1592 size
+= sizeof(data
->time
);
1594 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1595 size
+= sizeof(data
->id
);
1597 if (sample_type
& PERF_SAMPLE_ID
)
1598 size
+= sizeof(data
->id
);
1600 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1601 size
+= sizeof(data
->stream_id
);
1603 if (sample_type
& PERF_SAMPLE_CPU
)
1604 size
+= sizeof(data
->cpu_entry
);
1606 event
->id_header_size
= size
;
1609 static bool perf_event_validate_size(struct perf_event
*event
)
1612 * The values computed here will be over-written when we actually
1615 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1616 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1617 perf_event__id_header_size(event
);
1620 * Sum the lot; should not exceed the 64k limit we have on records.
1621 * Conservative limit to allow for callchains and other variable fields.
1623 if (event
->read_size
+ event
->header_size
+
1624 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1630 static void perf_group_attach(struct perf_event
*event
)
1632 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1634 lockdep_assert_held(&event
->ctx
->lock
);
1637 * We can have double attach due to group movement in perf_event_open.
1639 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1642 event
->attach_state
|= PERF_ATTACH_GROUP
;
1644 if (group_leader
== event
)
1647 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1649 group_leader
->group_caps
&= event
->event_caps
;
1651 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1652 group_leader
->nr_siblings
++;
1654 perf_event__header_size(group_leader
);
1656 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1657 perf_event__header_size(pos
);
1661 * Remove a event from the lists for its context.
1662 * Must be called with ctx->mutex and ctx->lock held.
1665 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1667 WARN_ON_ONCE(event
->ctx
!= ctx
);
1668 lockdep_assert_held(&ctx
->lock
);
1671 * We can have double detach due to exit/hot-unplug + close.
1673 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1676 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1678 list_update_cgroup_event(event
, ctx
, false);
1681 if (event
->attr
.inherit_stat
)
1684 list_del_rcu(&event
->event_entry
);
1686 if (event
->group_leader
== event
)
1687 list_del_init(&event
->group_entry
);
1690 * If event was in error state, then keep it
1691 * that way, otherwise bogus counts will be
1692 * returned on read(). The only way to get out
1693 * of error state is by explicit re-enabling
1696 if (event
->state
> PERF_EVENT_STATE_OFF
)
1697 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1702 static void perf_group_detach(struct perf_event
*event
)
1704 struct perf_event
*sibling
, *tmp
;
1705 struct list_head
*list
= NULL
;
1707 lockdep_assert_held(&event
->ctx
->lock
);
1710 * We can have double detach due to exit/hot-unplug + close.
1712 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1715 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1718 * If this is a sibling, remove it from its group.
1720 if (event
->group_leader
!= event
) {
1721 list_del_init(&event
->group_entry
);
1722 event
->group_leader
->nr_siblings
--;
1726 if (!list_empty(&event
->group_entry
))
1727 list
= &event
->group_entry
;
1730 * If this was a group event with sibling events then
1731 * upgrade the siblings to singleton events by adding them
1732 * to whatever list we are on.
1734 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1736 list_move_tail(&sibling
->group_entry
, list
);
1737 sibling
->group_leader
= sibling
;
1739 /* Inherit group flags from the previous leader */
1740 sibling
->group_caps
= event
->group_caps
;
1742 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1746 perf_event__header_size(event
->group_leader
);
1748 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1749 perf_event__header_size(tmp
);
1752 static bool is_orphaned_event(struct perf_event
*event
)
1754 return event
->state
== PERF_EVENT_STATE_DEAD
;
1757 static inline int __pmu_filter_match(struct perf_event
*event
)
1759 struct pmu
*pmu
= event
->pmu
;
1760 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1764 * Check whether we should attempt to schedule an event group based on
1765 * PMU-specific filtering. An event group can consist of HW and SW events,
1766 * potentially with a SW leader, so we must check all the filters, to
1767 * determine whether a group is schedulable:
1769 static inline int pmu_filter_match(struct perf_event
*event
)
1771 struct perf_event
*child
;
1773 if (!__pmu_filter_match(event
))
1776 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1777 if (!__pmu_filter_match(child
))
1785 event_filter_match(struct perf_event
*event
)
1787 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1788 perf_cgroup_match(event
) && pmu_filter_match(event
);
1792 event_sched_out(struct perf_event
*event
,
1793 struct perf_cpu_context
*cpuctx
,
1794 struct perf_event_context
*ctx
)
1796 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
1798 WARN_ON_ONCE(event
->ctx
!= ctx
);
1799 lockdep_assert_held(&ctx
->lock
);
1801 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1804 perf_pmu_disable(event
->pmu
);
1806 event
->pmu
->del(event
, 0);
1809 if (event
->pending_disable
) {
1810 event
->pending_disable
= 0;
1811 state
= PERF_EVENT_STATE_OFF
;
1813 perf_event_set_state(event
, state
);
1815 if (!is_software_event(event
))
1816 cpuctx
->active_oncpu
--;
1817 if (!--ctx
->nr_active
)
1818 perf_event_ctx_deactivate(ctx
);
1819 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1821 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1822 cpuctx
->exclusive
= 0;
1824 perf_pmu_enable(event
->pmu
);
1828 group_sched_out(struct perf_event
*group_event
,
1829 struct perf_cpu_context
*cpuctx
,
1830 struct perf_event_context
*ctx
)
1832 struct perf_event
*event
;
1834 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1837 perf_pmu_disable(ctx
->pmu
);
1839 event_sched_out(group_event
, cpuctx
, ctx
);
1842 * Schedule out siblings (if any):
1844 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1845 event_sched_out(event
, cpuctx
, ctx
);
1847 perf_pmu_enable(ctx
->pmu
);
1849 if (group_event
->attr
.exclusive
)
1850 cpuctx
->exclusive
= 0;
1853 #define DETACH_GROUP 0x01UL
1856 * Cross CPU call to remove a performance event
1858 * We disable the event on the hardware level first. After that we
1859 * remove it from the context list.
1862 __perf_remove_from_context(struct perf_event
*event
,
1863 struct perf_cpu_context
*cpuctx
,
1864 struct perf_event_context
*ctx
,
1867 unsigned long flags
= (unsigned long)info
;
1869 if (ctx
->is_active
& EVENT_TIME
) {
1870 update_context_time(ctx
);
1871 update_cgrp_time_from_cpuctx(cpuctx
);
1874 event_sched_out(event
, cpuctx
, ctx
);
1875 if (flags
& DETACH_GROUP
)
1876 perf_group_detach(event
);
1877 list_del_event(event
, ctx
);
1879 if (!ctx
->nr_events
&& ctx
->is_active
) {
1882 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1883 cpuctx
->task_ctx
= NULL
;
1889 * Remove the event from a task's (or a CPU's) list of events.
1891 * If event->ctx is a cloned context, callers must make sure that
1892 * every task struct that event->ctx->task could possibly point to
1893 * remains valid. This is OK when called from perf_release since
1894 * that only calls us on the top-level context, which can't be a clone.
1895 * When called from perf_event_exit_task, it's OK because the
1896 * context has been detached from its task.
1898 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1900 struct perf_event_context
*ctx
= event
->ctx
;
1902 lockdep_assert_held(&ctx
->mutex
);
1904 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1907 * The above event_function_call() can NO-OP when it hits
1908 * TASK_TOMBSTONE. In that case we must already have been detached
1909 * from the context (by perf_event_exit_event()) but the grouping
1910 * might still be in-tact.
1912 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1913 if ((flags
& DETACH_GROUP
) &&
1914 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1916 * Since in that case we cannot possibly be scheduled, simply
1919 raw_spin_lock_irq(&ctx
->lock
);
1920 perf_group_detach(event
);
1921 raw_spin_unlock_irq(&ctx
->lock
);
1926 * Cross CPU call to disable a performance event
1928 static void __perf_event_disable(struct perf_event
*event
,
1929 struct perf_cpu_context
*cpuctx
,
1930 struct perf_event_context
*ctx
,
1933 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1936 if (ctx
->is_active
& EVENT_TIME
) {
1937 update_context_time(ctx
);
1938 update_cgrp_time_from_event(event
);
1941 if (event
== event
->group_leader
)
1942 group_sched_out(event
, cpuctx
, ctx
);
1944 event_sched_out(event
, cpuctx
, ctx
);
1946 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1952 * If event->ctx is a cloned context, callers must make sure that
1953 * every task struct that event->ctx->task could possibly point to
1954 * remains valid. This condition is satisifed when called through
1955 * perf_event_for_each_child or perf_event_for_each because they
1956 * hold the top-level event's child_mutex, so any descendant that
1957 * goes to exit will block in perf_event_exit_event().
1959 * When called from perf_pending_event it's OK because event->ctx
1960 * is the current context on this CPU and preemption is disabled,
1961 * hence we can't get into perf_event_task_sched_out for this context.
1963 static void _perf_event_disable(struct perf_event
*event
)
1965 struct perf_event_context
*ctx
= event
->ctx
;
1967 raw_spin_lock_irq(&ctx
->lock
);
1968 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1969 raw_spin_unlock_irq(&ctx
->lock
);
1972 raw_spin_unlock_irq(&ctx
->lock
);
1974 event_function_call(event
, __perf_event_disable
, NULL
);
1977 void perf_event_disable_local(struct perf_event
*event
)
1979 event_function_local(event
, __perf_event_disable
, NULL
);
1983 * Strictly speaking kernel users cannot create groups and therefore this
1984 * interface does not need the perf_event_ctx_lock() magic.
1986 void perf_event_disable(struct perf_event
*event
)
1988 struct perf_event_context
*ctx
;
1990 ctx
= perf_event_ctx_lock(event
);
1991 _perf_event_disable(event
);
1992 perf_event_ctx_unlock(event
, ctx
);
1994 EXPORT_SYMBOL_GPL(perf_event_disable
);
1996 void perf_event_disable_inatomic(struct perf_event
*event
)
1998 event
->pending_disable
= 1;
1999 irq_work_queue(&event
->pending
);
2002 static void perf_set_shadow_time(struct perf_event
*event
,
2003 struct perf_event_context
*ctx
)
2006 * use the correct time source for the time snapshot
2008 * We could get by without this by leveraging the
2009 * fact that to get to this function, the caller
2010 * has most likely already called update_context_time()
2011 * and update_cgrp_time_xx() and thus both timestamp
2012 * are identical (or very close). Given that tstamp is,
2013 * already adjusted for cgroup, we could say that:
2014 * tstamp - ctx->timestamp
2016 * tstamp - cgrp->timestamp.
2018 * Then, in perf_output_read(), the calculation would
2019 * work with no changes because:
2020 * - event is guaranteed scheduled in
2021 * - no scheduled out in between
2022 * - thus the timestamp would be the same
2024 * But this is a bit hairy.
2026 * So instead, we have an explicit cgroup call to remain
2027 * within the time time source all along. We believe it
2028 * is cleaner and simpler to understand.
2030 if (is_cgroup_event(event
))
2031 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2033 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2036 #define MAX_INTERRUPTS (~0ULL)
2038 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2039 static void perf_log_itrace_start(struct perf_event
*event
);
2042 event_sched_in(struct perf_event
*event
,
2043 struct perf_cpu_context
*cpuctx
,
2044 struct perf_event_context
*ctx
)
2048 lockdep_assert_held(&ctx
->lock
);
2050 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2053 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2055 * Order event::oncpu write to happen before the ACTIVE state is
2056 * visible. This allows perf_event_{stop,read}() to observe the correct
2057 * ->oncpu if it sees ACTIVE.
2060 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2063 * Unthrottle events, since we scheduled we might have missed several
2064 * ticks already, also for a heavily scheduling task there is little
2065 * guarantee it'll get a tick in a timely manner.
2067 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2068 perf_log_throttle(event
, 1);
2069 event
->hw
.interrupts
= 0;
2072 perf_pmu_disable(event
->pmu
);
2074 perf_set_shadow_time(event
, ctx
);
2076 perf_log_itrace_start(event
);
2078 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2079 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2085 if (!is_software_event(event
))
2086 cpuctx
->active_oncpu
++;
2087 if (!ctx
->nr_active
++)
2088 perf_event_ctx_activate(ctx
);
2089 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2092 if (event
->attr
.exclusive
)
2093 cpuctx
->exclusive
= 1;
2096 perf_pmu_enable(event
->pmu
);
2102 group_sched_in(struct perf_event
*group_event
,
2103 struct perf_cpu_context
*cpuctx
,
2104 struct perf_event_context
*ctx
)
2106 struct perf_event
*event
, *partial_group
= NULL
;
2107 struct pmu
*pmu
= ctx
->pmu
;
2109 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2112 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2114 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2115 pmu
->cancel_txn(pmu
);
2116 perf_mux_hrtimer_restart(cpuctx
);
2121 * Schedule in siblings as one group (if any):
2123 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2124 if (event_sched_in(event
, cpuctx
, ctx
)) {
2125 partial_group
= event
;
2130 if (!pmu
->commit_txn(pmu
))
2135 * Groups can be scheduled in as one unit only, so undo any
2136 * partial group before returning:
2137 * The events up to the failed event are scheduled out normally.
2139 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2140 if (event
== partial_group
)
2143 event_sched_out(event
, cpuctx
, ctx
);
2145 event_sched_out(group_event
, cpuctx
, ctx
);
2147 pmu
->cancel_txn(pmu
);
2149 perf_mux_hrtimer_restart(cpuctx
);
2155 * Work out whether we can put this event group on the CPU now.
2157 static int group_can_go_on(struct perf_event
*event
,
2158 struct perf_cpu_context
*cpuctx
,
2162 * Groups consisting entirely of software events can always go on.
2164 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2167 * If an exclusive group is already on, no other hardware
2170 if (cpuctx
->exclusive
)
2173 * If this group is exclusive and there are already
2174 * events on the CPU, it can't go on.
2176 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2179 * Otherwise, try to add it if all previous groups were able
2185 static void add_event_to_ctx(struct perf_event
*event
,
2186 struct perf_event_context
*ctx
)
2188 list_add_event(event
, ctx
);
2189 perf_group_attach(event
);
2192 static void ctx_sched_out(struct perf_event_context
*ctx
,
2193 struct perf_cpu_context
*cpuctx
,
2194 enum event_type_t event_type
);
2196 ctx_sched_in(struct perf_event_context
*ctx
,
2197 struct perf_cpu_context
*cpuctx
,
2198 enum event_type_t event_type
,
2199 struct task_struct
*task
);
2201 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2202 struct perf_event_context
*ctx
,
2203 enum event_type_t event_type
)
2205 if (!cpuctx
->task_ctx
)
2208 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2211 ctx_sched_out(ctx
, cpuctx
, event_type
);
2214 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2215 struct perf_event_context
*ctx
,
2216 struct task_struct
*task
)
2218 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2220 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2221 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2223 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2227 * We want to maintain the following priority of scheduling:
2228 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2229 * - task pinned (EVENT_PINNED)
2230 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2231 * - task flexible (EVENT_FLEXIBLE).
2233 * In order to avoid unscheduling and scheduling back in everything every
2234 * time an event is added, only do it for the groups of equal priority and
2237 * This can be called after a batch operation on task events, in which case
2238 * event_type is a bit mask of the types of events involved. For CPU events,
2239 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2241 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2242 struct perf_event_context
*task_ctx
,
2243 enum event_type_t event_type
)
2245 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2246 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2249 * If pinned groups are involved, flexible groups also need to be
2252 if (event_type
& EVENT_PINNED
)
2253 event_type
|= EVENT_FLEXIBLE
;
2255 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2257 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2260 * Decide which cpu ctx groups to schedule out based on the types
2261 * of events that caused rescheduling:
2262 * - EVENT_CPU: schedule out corresponding groups;
2263 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2264 * - otherwise, do nothing more.
2267 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2268 else if (ctx_event_type
& EVENT_PINNED
)
2269 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2271 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2272 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2276 * Cross CPU call to install and enable a performance event
2278 * Very similar to remote_function() + event_function() but cannot assume that
2279 * things like ctx->is_active and cpuctx->task_ctx are set.
2281 static int __perf_install_in_context(void *info
)
2283 struct perf_event
*event
= info
;
2284 struct perf_event_context
*ctx
= event
->ctx
;
2285 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2286 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2287 bool reprogram
= true;
2290 raw_spin_lock(&cpuctx
->ctx
.lock
);
2292 raw_spin_lock(&ctx
->lock
);
2295 reprogram
= (ctx
->task
== current
);
2298 * If the task is running, it must be running on this CPU,
2299 * otherwise we cannot reprogram things.
2301 * If its not running, we don't care, ctx->lock will
2302 * serialize against it becoming runnable.
2304 if (task_curr(ctx
->task
) && !reprogram
) {
2309 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2310 } else if (task_ctx
) {
2311 raw_spin_lock(&task_ctx
->lock
);
2315 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2316 add_event_to_ctx(event
, ctx
);
2317 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2319 add_event_to_ctx(event
, ctx
);
2323 perf_ctx_unlock(cpuctx
, task_ctx
);
2329 * Attach a performance event to a context.
2331 * Very similar to event_function_call, see comment there.
2334 perf_install_in_context(struct perf_event_context
*ctx
,
2335 struct perf_event
*event
,
2338 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2340 lockdep_assert_held(&ctx
->mutex
);
2342 if (event
->cpu
!= -1)
2346 * Ensures that if we can observe event->ctx, both the event and ctx
2347 * will be 'complete'. See perf_iterate_sb_cpu().
2349 smp_store_release(&event
->ctx
, ctx
);
2352 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2357 * Should not happen, we validate the ctx is still alive before calling.
2359 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2363 * Installing events is tricky because we cannot rely on ctx->is_active
2364 * to be set in case this is the nr_events 0 -> 1 transition.
2366 * Instead we use task_curr(), which tells us if the task is running.
2367 * However, since we use task_curr() outside of rq::lock, we can race
2368 * against the actual state. This means the result can be wrong.
2370 * If we get a false positive, we retry, this is harmless.
2372 * If we get a false negative, things are complicated. If we are after
2373 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2374 * value must be correct. If we're before, it doesn't matter since
2375 * perf_event_context_sched_in() will program the counter.
2377 * However, this hinges on the remote context switch having observed
2378 * our task->perf_event_ctxp[] store, such that it will in fact take
2379 * ctx::lock in perf_event_context_sched_in().
2381 * We do this by task_function_call(), if the IPI fails to hit the task
2382 * we know any future context switch of task must see the
2383 * perf_event_ctpx[] store.
2387 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2388 * task_cpu() load, such that if the IPI then does not find the task
2389 * running, a future context switch of that task must observe the
2394 if (!task_function_call(task
, __perf_install_in_context
, event
))
2397 raw_spin_lock_irq(&ctx
->lock
);
2399 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2401 * Cannot happen because we already checked above (which also
2402 * cannot happen), and we hold ctx->mutex, which serializes us
2403 * against perf_event_exit_task_context().
2405 raw_spin_unlock_irq(&ctx
->lock
);
2409 * If the task is not running, ctx->lock will avoid it becoming so,
2410 * thus we can safely install the event.
2412 if (task_curr(task
)) {
2413 raw_spin_unlock_irq(&ctx
->lock
);
2416 add_event_to_ctx(event
, ctx
);
2417 raw_spin_unlock_irq(&ctx
->lock
);
2421 * Cross CPU call to enable a performance event
2423 static void __perf_event_enable(struct perf_event
*event
,
2424 struct perf_cpu_context
*cpuctx
,
2425 struct perf_event_context
*ctx
,
2428 struct perf_event
*leader
= event
->group_leader
;
2429 struct perf_event_context
*task_ctx
;
2431 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2432 event
->state
<= PERF_EVENT_STATE_ERROR
)
2436 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2438 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2440 if (!ctx
->is_active
)
2443 if (!event_filter_match(event
)) {
2444 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2449 * If the event is in a group and isn't the group leader,
2450 * then don't put it on unless the group is on.
2452 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2453 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2457 task_ctx
= cpuctx
->task_ctx
;
2459 WARN_ON_ONCE(task_ctx
!= ctx
);
2461 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2467 * If event->ctx is a cloned context, callers must make sure that
2468 * every task struct that event->ctx->task could possibly point to
2469 * remains valid. This condition is satisfied when called through
2470 * perf_event_for_each_child or perf_event_for_each as described
2471 * for perf_event_disable.
2473 static void _perf_event_enable(struct perf_event
*event
)
2475 struct perf_event_context
*ctx
= event
->ctx
;
2477 raw_spin_lock_irq(&ctx
->lock
);
2478 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2479 event
->state
< PERF_EVENT_STATE_ERROR
) {
2480 raw_spin_unlock_irq(&ctx
->lock
);
2485 * If the event is in error state, clear that first.
2487 * That way, if we see the event in error state below, we know that it
2488 * has gone back into error state, as distinct from the task having
2489 * been scheduled away before the cross-call arrived.
2491 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2492 event
->state
= PERF_EVENT_STATE_OFF
;
2493 raw_spin_unlock_irq(&ctx
->lock
);
2495 event_function_call(event
, __perf_event_enable
, NULL
);
2499 * See perf_event_disable();
2501 void perf_event_enable(struct perf_event
*event
)
2503 struct perf_event_context
*ctx
;
2505 ctx
= perf_event_ctx_lock(event
);
2506 _perf_event_enable(event
);
2507 perf_event_ctx_unlock(event
, ctx
);
2509 EXPORT_SYMBOL_GPL(perf_event_enable
);
2511 struct stop_event_data
{
2512 struct perf_event
*event
;
2513 unsigned int restart
;
2516 static int __perf_event_stop(void *info
)
2518 struct stop_event_data
*sd
= info
;
2519 struct perf_event
*event
= sd
->event
;
2521 /* if it's already INACTIVE, do nothing */
2522 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2525 /* matches smp_wmb() in event_sched_in() */
2529 * There is a window with interrupts enabled before we get here,
2530 * so we need to check again lest we try to stop another CPU's event.
2532 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2535 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2538 * May race with the actual stop (through perf_pmu_output_stop()),
2539 * but it is only used for events with AUX ring buffer, and such
2540 * events will refuse to restart because of rb::aux_mmap_count==0,
2541 * see comments in perf_aux_output_begin().
2543 * Since this is happening on a event-local CPU, no trace is lost
2547 event
->pmu
->start(event
, 0);
2552 static int perf_event_stop(struct perf_event
*event
, int restart
)
2554 struct stop_event_data sd
= {
2561 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2564 /* matches smp_wmb() in event_sched_in() */
2568 * We only want to restart ACTIVE events, so if the event goes
2569 * inactive here (event->oncpu==-1), there's nothing more to do;
2570 * fall through with ret==-ENXIO.
2572 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2573 __perf_event_stop
, &sd
);
2574 } while (ret
== -EAGAIN
);
2580 * In order to contain the amount of racy and tricky in the address filter
2581 * configuration management, it is a two part process:
2583 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2584 * we update the addresses of corresponding vmas in
2585 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2586 * (p2) when an event is scheduled in (pmu::add), it calls
2587 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2588 * if the generation has changed since the previous call.
2590 * If (p1) happens while the event is active, we restart it to force (p2).
2592 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2593 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2595 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2596 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2598 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2601 void perf_event_addr_filters_sync(struct perf_event
*event
)
2603 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2605 if (!has_addr_filter(event
))
2608 raw_spin_lock(&ifh
->lock
);
2609 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2610 event
->pmu
->addr_filters_sync(event
);
2611 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2613 raw_spin_unlock(&ifh
->lock
);
2615 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2617 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2620 * not supported on inherited events
2622 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2625 atomic_add(refresh
, &event
->event_limit
);
2626 _perf_event_enable(event
);
2632 * See perf_event_disable()
2634 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2636 struct perf_event_context
*ctx
;
2639 ctx
= perf_event_ctx_lock(event
);
2640 ret
= _perf_event_refresh(event
, refresh
);
2641 perf_event_ctx_unlock(event
, ctx
);
2645 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2647 static void ctx_sched_out(struct perf_event_context
*ctx
,
2648 struct perf_cpu_context
*cpuctx
,
2649 enum event_type_t event_type
)
2651 int is_active
= ctx
->is_active
;
2652 struct perf_event
*event
;
2654 lockdep_assert_held(&ctx
->lock
);
2656 if (likely(!ctx
->nr_events
)) {
2658 * See __perf_remove_from_context().
2660 WARN_ON_ONCE(ctx
->is_active
);
2662 WARN_ON_ONCE(cpuctx
->task_ctx
);
2666 ctx
->is_active
&= ~event_type
;
2667 if (!(ctx
->is_active
& EVENT_ALL
))
2671 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2672 if (!ctx
->is_active
)
2673 cpuctx
->task_ctx
= NULL
;
2677 * Always update time if it was set; not only when it changes.
2678 * Otherwise we can 'forget' to update time for any but the last
2679 * context we sched out. For example:
2681 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2682 * ctx_sched_out(.event_type = EVENT_PINNED)
2684 * would only update time for the pinned events.
2686 if (is_active
& EVENT_TIME
) {
2687 /* update (and stop) ctx time */
2688 update_context_time(ctx
);
2689 update_cgrp_time_from_cpuctx(cpuctx
);
2692 is_active
^= ctx
->is_active
; /* changed bits */
2694 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2697 perf_pmu_disable(ctx
->pmu
);
2698 if (is_active
& EVENT_PINNED
) {
2699 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2700 group_sched_out(event
, cpuctx
, ctx
);
2703 if (is_active
& EVENT_FLEXIBLE
) {
2704 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2705 group_sched_out(event
, cpuctx
, ctx
);
2707 perf_pmu_enable(ctx
->pmu
);
2711 * Test whether two contexts are equivalent, i.e. whether they have both been
2712 * cloned from the same version of the same context.
2714 * Equivalence is measured using a generation number in the context that is
2715 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2716 * and list_del_event().
2718 static int context_equiv(struct perf_event_context
*ctx1
,
2719 struct perf_event_context
*ctx2
)
2721 lockdep_assert_held(&ctx1
->lock
);
2722 lockdep_assert_held(&ctx2
->lock
);
2724 /* Pinning disables the swap optimization */
2725 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2728 /* If ctx1 is the parent of ctx2 */
2729 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2732 /* If ctx2 is the parent of ctx1 */
2733 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2737 * If ctx1 and ctx2 have the same parent; we flatten the parent
2738 * hierarchy, see perf_event_init_context().
2740 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2741 ctx1
->parent_gen
== ctx2
->parent_gen
)
2748 static void __perf_event_sync_stat(struct perf_event
*event
,
2749 struct perf_event
*next_event
)
2753 if (!event
->attr
.inherit_stat
)
2757 * Update the event value, we cannot use perf_event_read()
2758 * because we're in the middle of a context switch and have IRQs
2759 * disabled, which upsets smp_call_function_single(), however
2760 * we know the event must be on the current CPU, therefore we
2761 * don't need to use it.
2763 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2764 event
->pmu
->read(event
);
2766 perf_event_update_time(event
);
2769 * In order to keep per-task stats reliable we need to flip the event
2770 * values when we flip the contexts.
2772 value
= local64_read(&next_event
->count
);
2773 value
= local64_xchg(&event
->count
, value
);
2774 local64_set(&next_event
->count
, value
);
2776 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2777 swap(event
->total_time_running
, next_event
->total_time_running
);
2780 * Since we swizzled the values, update the user visible data too.
2782 perf_event_update_userpage(event
);
2783 perf_event_update_userpage(next_event
);
2786 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2787 struct perf_event_context
*next_ctx
)
2789 struct perf_event
*event
, *next_event
;
2794 update_context_time(ctx
);
2796 event
= list_first_entry(&ctx
->event_list
,
2797 struct perf_event
, event_entry
);
2799 next_event
= list_first_entry(&next_ctx
->event_list
,
2800 struct perf_event
, event_entry
);
2802 while (&event
->event_entry
!= &ctx
->event_list
&&
2803 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2805 __perf_event_sync_stat(event
, next_event
);
2807 event
= list_next_entry(event
, event_entry
);
2808 next_event
= list_next_entry(next_event
, event_entry
);
2812 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2813 struct task_struct
*next
)
2815 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2816 struct perf_event_context
*next_ctx
;
2817 struct perf_event_context
*parent
, *next_parent
;
2818 struct perf_cpu_context
*cpuctx
;
2824 cpuctx
= __get_cpu_context(ctx
);
2825 if (!cpuctx
->task_ctx
)
2829 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2833 parent
= rcu_dereference(ctx
->parent_ctx
);
2834 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2836 /* If neither context have a parent context; they cannot be clones. */
2837 if (!parent
&& !next_parent
)
2840 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2842 * Looks like the two contexts are clones, so we might be
2843 * able to optimize the context switch. We lock both
2844 * contexts and check that they are clones under the
2845 * lock (including re-checking that neither has been
2846 * uncloned in the meantime). It doesn't matter which
2847 * order we take the locks because no other cpu could
2848 * be trying to lock both of these tasks.
2850 raw_spin_lock(&ctx
->lock
);
2851 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2852 if (context_equiv(ctx
, next_ctx
)) {
2853 WRITE_ONCE(ctx
->task
, next
);
2854 WRITE_ONCE(next_ctx
->task
, task
);
2856 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2859 * RCU_INIT_POINTER here is safe because we've not
2860 * modified the ctx and the above modification of
2861 * ctx->task and ctx->task_ctx_data are immaterial
2862 * since those values are always verified under
2863 * ctx->lock which we're now holding.
2865 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2866 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2870 perf_event_sync_stat(ctx
, next_ctx
);
2872 raw_spin_unlock(&next_ctx
->lock
);
2873 raw_spin_unlock(&ctx
->lock
);
2879 raw_spin_lock(&ctx
->lock
);
2880 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2881 raw_spin_unlock(&ctx
->lock
);
2885 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2887 void perf_sched_cb_dec(struct pmu
*pmu
)
2889 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2891 this_cpu_dec(perf_sched_cb_usages
);
2893 if (!--cpuctx
->sched_cb_usage
)
2894 list_del(&cpuctx
->sched_cb_entry
);
2898 void perf_sched_cb_inc(struct pmu
*pmu
)
2900 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2902 if (!cpuctx
->sched_cb_usage
++)
2903 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2905 this_cpu_inc(perf_sched_cb_usages
);
2909 * This function provides the context switch callback to the lower code
2910 * layer. It is invoked ONLY when the context switch callback is enabled.
2912 * This callback is relevant even to per-cpu events; for example multi event
2913 * PEBS requires this to provide PID/TID information. This requires we flush
2914 * all queued PEBS records before we context switch to a new task.
2916 static void perf_pmu_sched_task(struct task_struct
*prev
,
2917 struct task_struct
*next
,
2920 struct perf_cpu_context
*cpuctx
;
2926 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2927 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2929 if (WARN_ON_ONCE(!pmu
->sched_task
))
2932 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2933 perf_pmu_disable(pmu
);
2935 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2937 perf_pmu_enable(pmu
);
2938 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2942 static void perf_event_switch(struct task_struct
*task
,
2943 struct task_struct
*next_prev
, bool sched_in
);
2945 #define for_each_task_context_nr(ctxn) \
2946 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2949 * Called from scheduler to remove the events of the current task,
2950 * with interrupts disabled.
2952 * We stop each event and update the event value in event->count.
2954 * This does not protect us against NMI, but disable()
2955 * sets the disabled bit in the control field of event _before_
2956 * accessing the event control register. If a NMI hits, then it will
2957 * not restart the event.
2959 void __perf_event_task_sched_out(struct task_struct
*task
,
2960 struct task_struct
*next
)
2964 if (__this_cpu_read(perf_sched_cb_usages
))
2965 perf_pmu_sched_task(task
, next
, false);
2967 if (atomic_read(&nr_switch_events
))
2968 perf_event_switch(task
, next
, false);
2970 for_each_task_context_nr(ctxn
)
2971 perf_event_context_sched_out(task
, ctxn
, next
);
2974 * if cgroup events exist on this CPU, then we need
2975 * to check if we have to switch out PMU state.
2976 * cgroup event are system-wide mode only
2978 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2979 perf_cgroup_sched_out(task
, next
);
2983 * Called with IRQs disabled
2985 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2986 enum event_type_t event_type
)
2988 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2992 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2993 struct perf_cpu_context
*cpuctx
)
2995 struct perf_event
*event
;
2997 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2998 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3000 if (!event_filter_match(event
))
3003 if (group_can_go_on(event
, cpuctx
, 1))
3004 group_sched_in(event
, cpuctx
, ctx
);
3007 * If this pinned group hasn't been scheduled,
3008 * put it in error state.
3010 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3011 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3016 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3017 struct perf_cpu_context
*cpuctx
)
3019 struct perf_event
*event
;
3022 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3023 /* Ignore events in OFF or ERROR state */
3024 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3027 * Listen to the 'cpu' scheduling filter constraint
3030 if (!event_filter_match(event
))
3033 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3034 if (group_sched_in(event
, cpuctx
, ctx
))
3041 ctx_sched_in(struct perf_event_context
*ctx
,
3042 struct perf_cpu_context
*cpuctx
,
3043 enum event_type_t event_type
,
3044 struct task_struct
*task
)
3046 int is_active
= ctx
->is_active
;
3049 lockdep_assert_held(&ctx
->lock
);
3051 if (likely(!ctx
->nr_events
))
3054 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3057 cpuctx
->task_ctx
= ctx
;
3059 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3062 is_active
^= ctx
->is_active
; /* changed bits */
3064 if (is_active
& EVENT_TIME
) {
3065 /* start ctx time */
3067 ctx
->timestamp
= now
;
3068 perf_cgroup_set_timestamp(task
, ctx
);
3072 * First go through the list and put on any pinned groups
3073 * in order to give them the best chance of going on.
3075 if (is_active
& EVENT_PINNED
)
3076 ctx_pinned_sched_in(ctx
, cpuctx
);
3078 /* Then walk through the lower prio flexible groups */
3079 if (is_active
& EVENT_FLEXIBLE
)
3080 ctx_flexible_sched_in(ctx
, cpuctx
);
3083 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3084 enum event_type_t event_type
,
3085 struct task_struct
*task
)
3087 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3089 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3092 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3093 struct task_struct
*task
)
3095 struct perf_cpu_context
*cpuctx
;
3097 cpuctx
= __get_cpu_context(ctx
);
3098 if (cpuctx
->task_ctx
== ctx
)
3101 perf_ctx_lock(cpuctx
, ctx
);
3103 * We must check ctx->nr_events while holding ctx->lock, such
3104 * that we serialize against perf_install_in_context().
3106 if (!ctx
->nr_events
)
3109 perf_pmu_disable(ctx
->pmu
);
3111 * We want to keep the following priority order:
3112 * cpu pinned (that don't need to move), task pinned,
3113 * cpu flexible, task flexible.
3115 * However, if task's ctx is not carrying any pinned
3116 * events, no need to flip the cpuctx's events around.
3118 if (!list_empty(&ctx
->pinned_groups
))
3119 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3120 perf_event_sched_in(cpuctx
, ctx
, task
);
3121 perf_pmu_enable(ctx
->pmu
);
3124 perf_ctx_unlock(cpuctx
, ctx
);
3128 * Called from scheduler to add the events of the current task
3129 * with interrupts disabled.
3131 * We restore the event value and then enable it.
3133 * This does not protect us against NMI, but enable()
3134 * sets the enabled bit in the control field of event _before_
3135 * accessing the event control register. If a NMI hits, then it will
3136 * keep the event running.
3138 void __perf_event_task_sched_in(struct task_struct
*prev
,
3139 struct task_struct
*task
)
3141 struct perf_event_context
*ctx
;
3145 * If cgroup events exist on this CPU, then we need to check if we have
3146 * to switch in PMU state; cgroup event are system-wide mode only.
3148 * Since cgroup events are CPU events, we must schedule these in before
3149 * we schedule in the task events.
3151 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3152 perf_cgroup_sched_in(prev
, task
);
3154 for_each_task_context_nr(ctxn
) {
3155 ctx
= task
->perf_event_ctxp
[ctxn
];
3159 perf_event_context_sched_in(ctx
, task
);
3162 if (atomic_read(&nr_switch_events
))
3163 perf_event_switch(task
, prev
, true);
3165 if (__this_cpu_read(perf_sched_cb_usages
))
3166 perf_pmu_sched_task(prev
, task
, true);
3169 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3171 u64 frequency
= event
->attr
.sample_freq
;
3172 u64 sec
= NSEC_PER_SEC
;
3173 u64 divisor
, dividend
;
3175 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3177 count_fls
= fls64(count
);
3178 nsec_fls
= fls64(nsec
);
3179 frequency_fls
= fls64(frequency
);
3183 * We got @count in @nsec, with a target of sample_freq HZ
3184 * the target period becomes:
3187 * period = -------------------
3188 * @nsec * sample_freq
3193 * Reduce accuracy by one bit such that @a and @b converge
3194 * to a similar magnitude.
3196 #define REDUCE_FLS(a, b) \
3198 if (a##_fls > b##_fls) { \
3208 * Reduce accuracy until either term fits in a u64, then proceed with
3209 * the other, so that finally we can do a u64/u64 division.
3211 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3212 REDUCE_FLS(nsec
, frequency
);
3213 REDUCE_FLS(sec
, count
);
3216 if (count_fls
+ sec_fls
> 64) {
3217 divisor
= nsec
* frequency
;
3219 while (count_fls
+ sec_fls
> 64) {
3220 REDUCE_FLS(count
, sec
);
3224 dividend
= count
* sec
;
3226 dividend
= count
* sec
;
3228 while (nsec_fls
+ frequency_fls
> 64) {
3229 REDUCE_FLS(nsec
, frequency
);
3233 divisor
= nsec
* frequency
;
3239 return div64_u64(dividend
, divisor
);
3242 static DEFINE_PER_CPU(int, perf_throttled_count
);
3243 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3245 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3247 struct hw_perf_event
*hwc
= &event
->hw
;
3248 s64 period
, sample_period
;
3251 period
= perf_calculate_period(event
, nsec
, count
);
3253 delta
= (s64
)(period
- hwc
->sample_period
);
3254 delta
= (delta
+ 7) / 8; /* low pass filter */
3256 sample_period
= hwc
->sample_period
+ delta
;
3261 hwc
->sample_period
= sample_period
;
3263 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3265 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3267 local64_set(&hwc
->period_left
, 0);
3270 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3275 * combine freq adjustment with unthrottling to avoid two passes over the
3276 * events. At the same time, make sure, having freq events does not change
3277 * the rate of unthrottling as that would introduce bias.
3279 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3282 struct perf_event
*event
;
3283 struct hw_perf_event
*hwc
;
3284 u64 now
, period
= TICK_NSEC
;
3288 * only need to iterate over all events iff:
3289 * - context have events in frequency mode (needs freq adjust)
3290 * - there are events to unthrottle on this cpu
3292 if (!(ctx
->nr_freq
|| needs_unthr
))
3295 raw_spin_lock(&ctx
->lock
);
3296 perf_pmu_disable(ctx
->pmu
);
3298 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3299 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3302 if (!event_filter_match(event
))
3305 perf_pmu_disable(event
->pmu
);
3309 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3310 hwc
->interrupts
= 0;
3311 perf_log_throttle(event
, 1);
3312 event
->pmu
->start(event
, 0);
3315 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3319 * stop the event and update event->count
3321 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3323 now
= local64_read(&event
->count
);
3324 delta
= now
- hwc
->freq_count_stamp
;
3325 hwc
->freq_count_stamp
= now
;
3329 * reload only if value has changed
3330 * we have stopped the event so tell that
3331 * to perf_adjust_period() to avoid stopping it
3335 perf_adjust_period(event
, period
, delta
, false);
3337 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3339 perf_pmu_enable(event
->pmu
);
3342 perf_pmu_enable(ctx
->pmu
);
3343 raw_spin_unlock(&ctx
->lock
);
3347 * Round-robin a context's events:
3349 static void rotate_ctx(struct perf_event_context
*ctx
)
3352 * Rotate the first entry last of non-pinned groups. Rotation might be
3353 * disabled by the inheritance code.
3355 if (!ctx
->rotate_disable
)
3356 list_rotate_left(&ctx
->flexible_groups
);
3359 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3361 struct perf_event_context
*ctx
= NULL
;
3364 if (cpuctx
->ctx
.nr_events
) {
3365 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3369 ctx
= cpuctx
->task_ctx
;
3370 if (ctx
&& ctx
->nr_events
) {
3371 if (ctx
->nr_events
!= ctx
->nr_active
)
3378 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3379 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3381 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3383 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3385 rotate_ctx(&cpuctx
->ctx
);
3389 perf_event_sched_in(cpuctx
, ctx
, current
);
3391 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3392 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3398 void perf_event_task_tick(void)
3400 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3401 struct perf_event_context
*ctx
, *tmp
;
3404 lockdep_assert_irqs_disabled();
3406 __this_cpu_inc(perf_throttled_seq
);
3407 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3408 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3410 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3411 perf_adjust_freq_unthr_context(ctx
, throttled
);
3414 static int event_enable_on_exec(struct perf_event
*event
,
3415 struct perf_event_context
*ctx
)
3417 if (!event
->attr
.enable_on_exec
)
3420 event
->attr
.enable_on_exec
= 0;
3421 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3424 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3430 * Enable all of a task's events that have been marked enable-on-exec.
3431 * This expects task == current.
3433 static void perf_event_enable_on_exec(int ctxn
)
3435 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3436 enum event_type_t event_type
= 0;
3437 struct perf_cpu_context
*cpuctx
;
3438 struct perf_event
*event
;
3439 unsigned long flags
;
3442 local_irq_save(flags
);
3443 ctx
= current
->perf_event_ctxp
[ctxn
];
3444 if (!ctx
|| !ctx
->nr_events
)
3447 cpuctx
= __get_cpu_context(ctx
);
3448 perf_ctx_lock(cpuctx
, ctx
);
3449 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3450 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3451 enabled
|= event_enable_on_exec(event
, ctx
);
3452 event_type
|= get_event_type(event
);
3456 * Unclone and reschedule this context if we enabled any event.
3459 clone_ctx
= unclone_ctx(ctx
);
3460 ctx_resched(cpuctx
, ctx
, event_type
);
3462 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3464 perf_ctx_unlock(cpuctx
, ctx
);
3467 local_irq_restore(flags
);
3473 struct perf_read_data
{
3474 struct perf_event
*event
;
3479 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3481 u16 local_pkg
, event_pkg
;
3483 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3484 int local_cpu
= smp_processor_id();
3486 event_pkg
= topology_physical_package_id(event_cpu
);
3487 local_pkg
= topology_physical_package_id(local_cpu
);
3489 if (event_pkg
== local_pkg
)
3497 * Cross CPU call to read the hardware event
3499 static void __perf_event_read(void *info
)
3501 struct perf_read_data
*data
= info
;
3502 struct perf_event
*sub
, *event
= data
->event
;
3503 struct perf_event_context
*ctx
= event
->ctx
;
3504 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3505 struct pmu
*pmu
= event
->pmu
;
3508 * If this is a task context, we need to check whether it is
3509 * the current task context of this cpu. If not it has been
3510 * scheduled out before the smp call arrived. In that case
3511 * event->count would have been updated to a recent sample
3512 * when the event was scheduled out.
3514 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3517 raw_spin_lock(&ctx
->lock
);
3518 if (ctx
->is_active
& EVENT_TIME
) {
3519 update_context_time(ctx
);
3520 update_cgrp_time_from_event(event
);
3523 perf_event_update_time(event
);
3525 perf_event_update_sibling_time(event
);
3527 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3536 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3540 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3541 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3543 * Use sibling's PMU rather than @event's since
3544 * sibling could be on different (eg: software) PMU.
3546 sub
->pmu
->read(sub
);
3550 data
->ret
= pmu
->commit_txn(pmu
);
3553 raw_spin_unlock(&ctx
->lock
);
3556 static inline u64
perf_event_count(struct perf_event
*event
)
3558 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3562 * NMI-safe method to read a local event, that is an event that
3564 * - either for the current task, or for this CPU
3565 * - does not have inherit set, for inherited task events
3566 * will not be local and we cannot read them atomically
3567 * - must not have a pmu::count method
3569 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
3570 u64
*enabled
, u64
*running
)
3572 unsigned long flags
;
3576 * Disabling interrupts avoids all counter scheduling (context
3577 * switches, timer based rotation and IPIs).
3579 local_irq_save(flags
);
3582 * It must not be an event with inherit set, we cannot read
3583 * all child counters from atomic context.
3585 if (event
->attr
.inherit
) {
3590 /* If this is a per-task event, it must be for current */
3591 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3592 event
->hw
.target
!= current
) {
3597 /* If this is a per-CPU event, it must be for this CPU */
3598 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3599 event
->cpu
!= smp_processor_id()) {
3605 * If the event is currently on this CPU, its either a per-task event,
3606 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3609 if (event
->oncpu
== smp_processor_id())
3610 event
->pmu
->read(event
);
3612 *value
= local64_read(&event
->count
);
3613 if (enabled
|| running
) {
3614 u64 now
= event
->shadow_ctx_time
+ perf_clock();
3615 u64 __enabled
, __running
;
3617 __perf_update_times(event
, now
, &__enabled
, &__running
);
3619 *enabled
= __enabled
;
3621 *running
= __running
;
3624 local_irq_restore(flags
);
3629 static int perf_event_read(struct perf_event
*event
, bool group
)
3631 enum perf_event_state state
= READ_ONCE(event
->state
);
3632 int event_cpu
, ret
= 0;
3635 * If event is enabled and currently active on a CPU, update the
3636 * value in the event structure:
3639 if (state
== PERF_EVENT_STATE_ACTIVE
) {
3640 struct perf_read_data data
;
3643 * Orders the ->state and ->oncpu loads such that if we see
3644 * ACTIVE we must also see the right ->oncpu.
3646 * Matches the smp_wmb() from event_sched_in().
3650 event_cpu
= READ_ONCE(event
->oncpu
);
3651 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3654 data
= (struct perf_read_data
){
3661 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3664 * Purposely ignore the smp_call_function_single() return
3667 * If event_cpu isn't a valid CPU it means the event got
3668 * scheduled out and that will have updated the event count.
3670 * Therefore, either way, we'll have an up-to-date event count
3673 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3677 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
3678 struct perf_event_context
*ctx
= event
->ctx
;
3679 unsigned long flags
;
3681 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3682 state
= event
->state
;
3683 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
3684 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3689 * May read while context is not active (e.g., thread is
3690 * blocked), in that case we cannot update context time
3692 if (ctx
->is_active
& EVENT_TIME
) {
3693 update_context_time(ctx
);
3694 update_cgrp_time_from_event(event
);
3697 perf_event_update_time(event
);
3699 perf_event_update_sibling_time(event
);
3700 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3707 * Initialize the perf_event context in a task_struct:
3709 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3711 raw_spin_lock_init(&ctx
->lock
);
3712 mutex_init(&ctx
->mutex
);
3713 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3714 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3715 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3716 INIT_LIST_HEAD(&ctx
->event_list
);
3717 atomic_set(&ctx
->refcount
, 1);
3720 static struct perf_event_context
*
3721 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3723 struct perf_event_context
*ctx
;
3725 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3729 __perf_event_init_context(ctx
);
3732 get_task_struct(task
);
3739 static struct task_struct
*
3740 find_lively_task_by_vpid(pid_t vpid
)
3742 struct task_struct
*task
;
3748 task
= find_task_by_vpid(vpid
);
3750 get_task_struct(task
);
3754 return ERR_PTR(-ESRCH
);
3760 * Returns a matching context with refcount and pincount.
3762 static struct perf_event_context
*
3763 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3764 struct perf_event
*event
)
3766 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3767 struct perf_cpu_context
*cpuctx
;
3768 void *task_ctx_data
= NULL
;
3769 unsigned long flags
;
3771 int cpu
= event
->cpu
;
3774 /* Must be root to operate on a CPU event: */
3775 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3776 return ERR_PTR(-EACCES
);
3778 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3787 ctxn
= pmu
->task_ctx_nr
;
3791 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3792 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3793 if (!task_ctx_data
) {
3800 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3802 clone_ctx
= unclone_ctx(ctx
);
3805 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3806 ctx
->task_ctx_data
= task_ctx_data
;
3807 task_ctx_data
= NULL
;
3809 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3814 ctx
= alloc_perf_context(pmu
, task
);
3819 if (task_ctx_data
) {
3820 ctx
->task_ctx_data
= task_ctx_data
;
3821 task_ctx_data
= NULL
;
3825 mutex_lock(&task
->perf_event_mutex
);
3827 * If it has already passed perf_event_exit_task().
3828 * we must see PF_EXITING, it takes this mutex too.
3830 if (task
->flags
& PF_EXITING
)
3832 else if (task
->perf_event_ctxp
[ctxn
])
3837 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3839 mutex_unlock(&task
->perf_event_mutex
);
3841 if (unlikely(err
)) {
3850 kfree(task_ctx_data
);
3854 kfree(task_ctx_data
);
3855 return ERR_PTR(err
);
3858 static void perf_event_free_filter(struct perf_event
*event
);
3859 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3861 static void free_event_rcu(struct rcu_head
*head
)
3863 struct perf_event
*event
;
3865 event
= container_of(head
, struct perf_event
, rcu_head
);
3867 put_pid_ns(event
->ns
);
3868 perf_event_free_filter(event
);
3872 static void ring_buffer_attach(struct perf_event
*event
,
3873 struct ring_buffer
*rb
);
3875 static void detach_sb_event(struct perf_event
*event
)
3877 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3879 raw_spin_lock(&pel
->lock
);
3880 list_del_rcu(&event
->sb_list
);
3881 raw_spin_unlock(&pel
->lock
);
3884 static bool is_sb_event(struct perf_event
*event
)
3886 struct perf_event_attr
*attr
= &event
->attr
;
3891 if (event
->attach_state
& PERF_ATTACH_TASK
)
3894 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3895 attr
->comm
|| attr
->comm_exec
||
3897 attr
->context_switch
)
3902 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3904 if (is_sb_event(event
))
3905 detach_sb_event(event
);
3908 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3913 if (is_cgroup_event(event
))
3914 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3917 #ifdef CONFIG_NO_HZ_FULL
3918 static DEFINE_SPINLOCK(nr_freq_lock
);
3921 static void unaccount_freq_event_nohz(void)
3923 #ifdef CONFIG_NO_HZ_FULL
3924 spin_lock(&nr_freq_lock
);
3925 if (atomic_dec_and_test(&nr_freq_events
))
3926 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3927 spin_unlock(&nr_freq_lock
);
3931 static void unaccount_freq_event(void)
3933 if (tick_nohz_full_enabled())
3934 unaccount_freq_event_nohz();
3936 atomic_dec(&nr_freq_events
);
3939 static void unaccount_event(struct perf_event
*event
)
3946 if (event
->attach_state
& PERF_ATTACH_TASK
)
3948 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3949 atomic_dec(&nr_mmap_events
);
3950 if (event
->attr
.comm
)
3951 atomic_dec(&nr_comm_events
);
3952 if (event
->attr
.namespaces
)
3953 atomic_dec(&nr_namespaces_events
);
3954 if (event
->attr
.task
)
3955 atomic_dec(&nr_task_events
);
3956 if (event
->attr
.freq
)
3957 unaccount_freq_event();
3958 if (event
->attr
.context_switch
) {
3960 atomic_dec(&nr_switch_events
);
3962 if (is_cgroup_event(event
))
3964 if (has_branch_stack(event
))
3968 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3969 schedule_delayed_work(&perf_sched_work
, HZ
);
3972 unaccount_event_cpu(event
, event
->cpu
);
3974 unaccount_pmu_sb_event(event
);
3977 static void perf_sched_delayed(struct work_struct
*work
)
3979 mutex_lock(&perf_sched_mutex
);
3980 if (atomic_dec_and_test(&perf_sched_count
))
3981 static_branch_disable(&perf_sched_events
);
3982 mutex_unlock(&perf_sched_mutex
);
3986 * The following implement mutual exclusion of events on "exclusive" pmus
3987 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3988 * at a time, so we disallow creating events that might conflict, namely:
3990 * 1) cpu-wide events in the presence of per-task events,
3991 * 2) per-task events in the presence of cpu-wide events,
3992 * 3) two matching events on the same context.
3994 * The former two cases are handled in the allocation path (perf_event_alloc(),
3995 * _free_event()), the latter -- before the first perf_install_in_context().
3997 static int exclusive_event_init(struct perf_event
*event
)
3999 struct pmu
*pmu
= event
->pmu
;
4001 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4005 * Prevent co-existence of per-task and cpu-wide events on the
4006 * same exclusive pmu.
4008 * Negative pmu::exclusive_cnt means there are cpu-wide
4009 * events on this "exclusive" pmu, positive means there are
4012 * Since this is called in perf_event_alloc() path, event::ctx
4013 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4014 * to mean "per-task event", because unlike other attach states it
4015 * never gets cleared.
4017 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4018 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4021 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4028 static void exclusive_event_destroy(struct perf_event
*event
)
4030 struct pmu
*pmu
= event
->pmu
;
4032 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4035 /* see comment in exclusive_event_init() */
4036 if (event
->attach_state
& PERF_ATTACH_TASK
)
4037 atomic_dec(&pmu
->exclusive_cnt
);
4039 atomic_inc(&pmu
->exclusive_cnt
);
4042 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4044 if ((e1
->pmu
== e2
->pmu
) &&
4045 (e1
->cpu
== e2
->cpu
||
4052 /* Called under the same ctx::mutex as perf_install_in_context() */
4053 static bool exclusive_event_installable(struct perf_event
*event
,
4054 struct perf_event_context
*ctx
)
4056 struct perf_event
*iter_event
;
4057 struct pmu
*pmu
= event
->pmu
;
4059 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4062 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4063 if (exclusive_event_match(iter_event
, event
))
4070 static void perf_addr_filters_splice(struct perf_event
*event
,
4071 struct list_head
*head
);
4073 static void _free_event(struct perf_event
*event
)
4075 irq_work_sync(&event
->pending
);
4077 unaccount_event(event
);
4081 * Can happen when we close an event with re-directed output.
4083 * Since we have a 0 refcount, perf_mmap_close() will skip
4084 * over us; possibly making our ring_buffer_put() the last.
4086 mutex_lock(&event
->mmap_mutex
);
4087 ring_buffer_attach(event
, NULL
);
4088 mutex_unlock(&event
->mmap_mutex
);
4091 if (is_cgroup_event(event
))
4092 perf_detach_cgroup(event
);
4094 if (!event
->parent
) {
4095 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4096 put_callchain_buffers();
4099 perf_event_free_bpf_prog(event
);
4100 perf_addr_filters_splice(event
, NULL
);
4101 kfree(event
->addr_filters_offs
);
4104 event
->destroy(event
);
4107 put_ctx(event
->ctx
);
4109 exclusive_event_destroy(event
);
4110 module_put(event
->pmu
->module
);
4112 call_rcu(&event
->rcu_head
, free_event_rcu
);
4116 * Used to free events which have a known refcount of 1, such as in error paths
4117 * where the event isn't exposed yet and inherited events.
4119 static void free_event(struct perf_event
*event
)
4121 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4122 "unexpected event refcount: %ld; ptr=%p\n",
4123 atomic_long_read(&event
->refcount
), event
)) {
4124 /* leak to avoid use-after-free */
4132 * Remove user event from the owner task.
4134 static void perf_remove_from_owner(struct perf_event
*event
)
4136 struct task_struct
*owner
;
4140 * Matches the smp_store_release() in perf_event_exit_task(). If we
4141 * observe !owner it means the list deletion is complete and we can
4142 * indeed free this event, otherwise we need to serialize on
4143 * owner->perf_event_mutex.
4145 owner
= READ_ONCE(event
->owner
);
4148 * Since delayed_put_task_struct() also drops the last
4149 * task reference we can safely take a new reference
4150 * while holding the rcu_read_lock().
4152 get_task_struct(owner
);
4158 * If we're here through perf_event_exit_task() we're already
4159 * holding ctx->mutex which would be an inversion wrt. the
4160 * normal lock order.
4162 * However we can safely take this lock because its the child
4165 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4168 * We have to re-check the event->owner field, if it is cleared
4169 * we raced with perf_event_exit_task(), acquiring the mutex
4170 * ensured they're done, and we can proceed with freeing the
4174 list_del_init(&event
->owner_entry
);
4175 smp_store_release(&event
->owner
, NULL
);
4177 mutex_unlock(&owner
->perf_event_mutex
);
4178 put_task_struct(owner
);
4182 static void put_event(struct perf_event
*event
)
4184 if (!atomic_long_dec_and_test(&event
->refcount
))
4191 * Kill an event dead; while event:refcount will preserve the event
4192 * object, it will not preserve its functionality. Once the last 'user'
4193 * gives up the object, we'll destroy the thing.
4195 int perf_event_release_kernel(struct perf_event
*event
)
4197 struct perf_event_context
*ctx
= event
->ctx
;
4198 struct perf_event
*child
, *tmp
;
4201 * If we got here through err_file: fput(event_file); we will not have
4202 * attached to a context yet.
4205 WARN_ON_ONCE(event
->attach_state
&
4206 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4210 if (!is_kernel_event(event
))
4211 perf_remove_from_owner(event
);
4213 ctx
= perf_event_ctx_lock(event
);
4214 WARN_ON_ONCE(ctx
->parent_ctx
);
4215 perf_remove_from_context(event
, DETACH_GROUP
);
4217 raw_spin_lock_irq(&ctx
->lock
);
4219 * Mark this event as STATE_DEAD, there is no external reference to it
4222 * Anybody acquiring event->child_mutex after the below loop _must_
4223 * also see this, most importantly inherit_event() which will avoid
4224 * placing more children on the list.
4226 * Thus this guarantees that we will in fact observe and kill _ALL_
4229 event
->state
= PERF_EVENT_STATE_DEAD
;
4230 raw_spin_unlock_irq(&ctx
->lock
);
4232 perf_event_ctx_unlock(event
, ctx
);
4235 mutex_lock(&event
->child_mutex
);
4236 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4239 * Cannot change, child events are not migrated, see the
4240 * comment with perf_event_ctx_lock_nested().
4242 ctx
= READ_ONCE(child
->ctx
);
4244 * Since child_mutex nests inside ctx::mutex, we must jump
4245 * through hoops. We start by grabbing a reference on the ctx.
4247 * Since the event cannot get freed while we hold the
4248 * child_mutex, the context must also exist and have a !0
4254 * Now that we have a ctx ref, we can drop child_mutex, and
4255 * acquire ctx::mutex without fear of it going away. Then we
4256 * can re-acquire child_mutex.
4258 mutex_unlock(&event
->child_mutex
);
4259 mutex_lock(&ctx
->mutex
);
4260 mutex_lock(&event
->child_mutex
);
4263 * Now that we hold ctx::mutex and child_mutex, revalidate our
4264 * state, if child is still the first entry, it didn't get freed
4265 * and we can continue doing so.
4267 tmp
= list_first_entry_or_null(&event
->child_list
,
4268 struct perf_event
, child_list
);
4270 perf_remove_from_context(child
, DETACH_GROUP
);
4271 list_del(&child
->child_list
);
4274 * This matches the refcount bump in inherit_event();
4275 * this can't be the last reference.
4280 mutex_unlock(&event
->child_mutex
);
4281 mutex_unlock(&ctx
->mutex
);
4285 mutex_unlock(&event
->child_mutex
);
4288 put_event(event
); /* Must be the 'last' reference */
4291 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4294 * Called when the last reference to the file is gone.
4296 static int perf_release(struct inode
*inode
, struct file
*file
)
4298 perf_event_release_kernel(file
->private_data
);
4302 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4304 struct perf_event
*child
;
4310 mutex_lock(&event
->child_mutex
);
4312 (void)perf_event_read(event
, false);
4313 total
+= perf_event_count(event
);
4315 *enabled
+= event
->total_time_enabled
+
4316 atomic64_read(&event
->child_total_time_enabled
);
4317 *running
+= event
->total_time_running
+
4318 atomic64_read(&event
->child_total_time_running
);
4320 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4321 (void)perf_event_read(child
, false);
4322 total
+= perf_event_count(child
);
4323 *enabled
+= child
->total_time_enabled
;
4324 *running
+= child
->total_time_running
;
4326 mutex_unlock(&event
->child_mutex
);
4331 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4333 struct perf_event_context
*ctx
;
4336 ctx
= perf_event_ctx_lock(event
);
4337 count
= __perf_event_read_value(event
, enabled
, running
);
4338 perf_event_ctx_unlock(event
, ctx
);
4342 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4344 static int __perf_read_group_add(struct perf_event
*leader
,
4345 u64 read_format
, u64
*values
)
4347 struct perf_event_context
*ctx
= leader
->ctx
;
4348 struct perf_event
*sub
;
4349 unsigned long flags
;
4350 int n
= 1; /* skip @nr */
4353 ret
= perf_event_read(leader
, true);
4357 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4360 * Since we co-schedule groups, {enabled,running} times of siblings
4361 * will be identical to those of the leader, so we only publish one
4364 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4365 values
[n
++] += leader
->total_time_enabled
+
4366 atomic64_read(&leader
->child_total_time_enabled
);
4369 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4370 values
[n
++] += leader
->total_time_running
+
4371 atomic64_read(&leader
->child_total_time_running
);
4375 * Write {count,id} tuples for every sibling.
4377 values
[n
++] += perf_event_count(leader
);
4378 if (read_format
& PERF_FORMAT_ID
)
4379 values
[n
++] = primary_event_id(leader
);
4381 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4382 values
[n
++] += perf_event_count(sub
);
4383 if (read_format
& PERF_FORMAT_ID
)
4384 values
[n
++] = primary_event_id(sub
);
4387 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4391 static int perf_read_group(struct perf_event
*event
,
4392 u64 read_format
, char __user
*buf
)
4394 struct perf_event
*leader
= event
->group_leader
, *child
;
4395 struct perf_event_context
*ctx
= leader
->ctx
;
4399 lockdep_assert_held(&ctx
->mutex
);
4401 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4405 values
[0] = 1 + leader
->nr_siblings
;
4408 * By locking the child_mutex of the leader we effectively
4409 * lock the child list of all siblings.. XXX explain how.
4411 mutex_lock(&leader
->child_mutex
);
4413 ret
= __perf_read_group_add(leader
, read_format
, values
);
4417 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4418 ret
= __perf_read_group_add(child
, read_format
, values
);
4423 mutex_unlock(&leader
->child_mutex
);
4425 ret
= event
->read_size
;
4426 if (copy_to_user(buf
, values
, event
->read_size
))
4431 mutex_unlock(&leader
->child_mutex
);
4437 static int perf_read_one(struct perf_event
*event
,
4438 u64 read_format
, char __user
*buf
)
4440 u64 enabled
, running
;
4444 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4445 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4446 values
[n
++] = enabled
;
4447 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4448 values
[n
++] = running
;
4449 if (read_format
& PERF_FORMAT_ID
)
4450 values
[n
++] = primary_event_id(event
);
4452 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4455 return n
* sizeof(u64
);
4458 static bool is_event_hup(struct perf_event
*event
)
4462 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4465 mutex_lock(&event
->child_mutex
);
4466 no_children
= list_empty(&event
->child_list
);
4467 mutex_unlock(&event
->child_mutex
);
4472 * Read the performance event - simple non blocking version for now
4475 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4477 u64 read_format
= event
->attr
.read_format
;
4481 * Return end-of-file for a read on a event that is in
4482 * error state (i.e. because it was pinned but it couldn't be
4483 * scheduled on to the CPU at some point).
4485 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4488 if (count
< event
->read_size
)
4491 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4492 if (read_format
& PERF_FORMAT_GROUP
)
4493 ret
= perf_read_group(event
, read_format
, buf
);
4495 ret
= perf_read_one(event
, read_format
, buf
);
4501 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4503 struct perf_event
*event
= file
->private_data
;
4504 struct perf_event_context
*ctx
;
4507 ctx
= perf_event_ctx_lock(event
);
4508 ret
= __perf_read(event
, buf
, count
);
4509 perf_event_ctx_unlock(event
, ctx
);
4514 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4516 struct perf_event
*event
= file
->private_data
;
4517 struct ring_buffer
*rb
;
4518 unsigned int events
= POLLHUP
;
4520 poll_wait(file
, &event
->waitq
, wait
);
4522 if (is_event_hup(event
))
4526 * Pin the event->rb by taking event->mmap_mutex; otherwise
4527 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4529 mutex_lock(&event
->mmap_mutex
);
4532 events
= atomic_xchg(&rb
->poll
, 0);
4533 mutex_unlock(&event
->mmap_mutex
);
4537 static void _perf_event_reset(struct perf_event
*event
)
4539 (void)perf_event_read(event
, false);
4540 local64_set(&event
->count
, 0);
4541 perf_event_update_userpage(event
);
4545 * Holding the top-level event's child_mutex means that any
4546 * descendant process that has inherited this event will block
4547 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4548 * task existence requirements of perf_event_enable/disable.
4550 static void perf_event_for_each_child(struct perf_event
*event
,
4551 void (*func
)(struct perf_event
*))
4553 struct perf_event
*child
;
4555 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4557 mutex_lock(&event
->child_mutex
);
4559 list_for_each_entry(child
, &event
->child_list
, child_list
)
4561 mutex_unlock(&event
->child_mutex
);
4564 static void perf_event_for_each(struct perf_event
*event
,
4565 void (*func
)(struct perf_event
*))
4567 struct perf_event_context
*ctx
= event
->ctx
;
4568 struct perf_event
*sibling
;
4570 lockdep_assert_held(&ctx
->mutex
);
4572 event
= event
->group_leader
;
4574 perf_event_for_each_child(event
, func
);
4575 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4576 perf_event_for_each_child(sibling
, func
);
4579 static void __perf_event_period(struct perf_event
*event
,
4580 struct perf_cpu_context
*cpuctx
,
4581 struct perf_event_context
*ctx
,
4584 u64 value
= *((u64
*)info
);
4587 if (event
->attr
.freq
) {
4588 event
->attr
.sample_freq
= value
;
4590 event
->attr
.sample_period
= value
;
4591 event
->hw
.sample_period
= value
;
4594 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4596 perf_pmu_disable(ctx
->pmu
);
4598 * We could be throttled; unthrottle now to avoid the tick
4599 * trying to unthrottle while we already re-started the event.
4601 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4602 event
->hw
.interrupts
= 0;
4603 perf_log_throttle(event
, 1);
4605 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4608 local64_set(&event
->hw
.period_left
, 0);
4611 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4612 perf_pmu_enable(ctx
->pmu
);
4616 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4620 if (!is_sampling_event(event
))
4623 if (copy_from_user(&value
, arg
, sizeof(value
)))
4629 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4632 event_function_call(event
, __perf_event_period
, &value
);
4637 static const struct file_operations perf_fops
;
4639 static inline int perf_fget_light(int fd
, struct fd
*p
)
4641 struct fd f
= fdget(fd
);
4645 if (f
.file
->f_op
!= &perf_fops
) {
4653 static int perf_event_set_output(struct perf_event
*event
,
4654 struct perf_event
*output_event
);
4655 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4656 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4658 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4660 void (*func
)(struct perf_event
*);
4664 case PERF_EVENT_IOC_ENABLE
:
4665 func
= _perf_event_enable
;
4667 case PERF_EVENT_IOC_DISABLE
:
4668 func
= _perf_event_disable
;
4670 case PERF_EVENT_IOC_RESET
:
4671 func
= _perf_event_reset
;
4674 case PERF_EVENT_IOC_REFRESH
:
4675 return _perf_event_refresh(event
, arg
);
4677 case PERF_EVENT_IOC_PERIOD
:
4678 return perf_event_period(event
, (u64 __user
*)arg
);
4680 case PERF_EVENT_IOC_ID
:
4682 u64 id
= primary_event_id(event
);
4684 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4689 case PERF_EVENT_IOC_SET_OUTPUT
:
4693 struct perf_event
*output_event
;
4695 ret
= perf_fget_light(arg
, &output
);
4698 output_event
= output
.file
->private_data
;
4699 ret
= perf_event_set_output(event
, output_event
);
4702 ret
= perf_event_set_output(event
, NULL
);
4707 case PERF_EVENT_IOC_SET_FILTER
:
4708 return perf_event_set_filter(event
, (void __user
*)arg
);
4710 case PERF_EVENT_IOC_SET_BPF
:
4711 return perf_event_set_bpf_prog(event
, arg
);
4713 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4714 struct ring_buffer
*rb
;
4717 rb
= rcu_dereference(event
->rb
);
4718 if (!rb
|| !rb
->nr_pages
) {
4722 rb_toggle_paused(rb
, !!arg
);
4730 if (flags
& PERF_IOC_FLAG_GROUP
)
4731 perf_event_for_each(event
, func
);
4733 perf_event_for_each_child(event
, func
);
4738 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4740 struct perf_event
*event
= file
->private_data
;
4741 struct perf_event_context
*ctx
;
4744 ctx
= perf_event_ctx_lock(event
);
4745 ret
= _perf_ioctl(event
, cmd
, arg
);
4746 perf_event_ctx_unlock(event
, ctx
);
4751 #ifdef CONFIG_COMPAT
4752 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4755 switch (_IOC_NR(cmd
)) {
4756 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4757 case _IOC_NR(PERF_EVENT_IOC_ID
):
4758 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4759 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4760 cmd
&= ~IOCSIZE_MASK
;
4761 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4765 return perf_ioctl(file
, cmd
, arg
);
4768 # define perf_compat_ioctl NULL
4771 int perf_event_task_enable(void)
4773 struct perf_event_context
*ctx
;
4774 struct perf_event
*event
;
4776 mutex_lock(¤t
->perf_event_mutex
);
4777 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4778 ctx
= perf_event_ctx_lock(event
);
4779 perf_event_for_each_child(event
, _perf_event_enable
);
4780 perf_event_ctx_unlock(event
, ctx
);
4782 mutex_unlock(¤t
->perf_event_mutex
);
4787 int perf_event_task_disable(void)
4789 struct perf_event_context
*ctx
;
4790 struct perf_event
*event
;
4792 mutex_lock(¤t
->perf_event_mutex
);
4793 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4794 ctx
= perf_event_ctx_lock(event
);
4795 perf_event_for_each_child(event
, _perf_event_disable
);
4796 perf_event_ctx_unlock(event
, ctx
);
4798 mutex_unlock(¤t
->perf_event_mutex
);
4803 static int perf_event_index(struct perf_event
*event
)
4805 if (event
->hw
.state
& PERF_HES_STOPPED
)
4808 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4811 return event
->pmu
->event_idx(event
);
4814 static void calc_timer_values(struct perf_event
*event
,
4821 *now
= perf_clock();
4822 ctx_time
= event
->shadow_ctx_time
+ *now
;
4823 __perf_update_times(event
, ctx_time
, enabled
, running
);
4826 static void perf_event_init_userpage(struct perf_event
*event
)
4828 struct perf_event_mmap_page
*userpg
;
4829 struct ring_buffer
*rb
;
4832 rb
= rcu_dereference(event
->rb
);
4836 userpg
= rb
->user_page
;
4838 /* Allow new userspace to detect that bit 0 is deprecated */
4839 userpg
->cap_bit0_is_deprecated
= 1;
4840 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4841 userpg
->data_offset
= PAGE_SIZE
;
4842 userpg
->data_size
= perf_data_size(rb
);
4848 void __weak
arch_perf_update_userpage(
4849 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4854 * Callers need to ensure there can be no nesting of this function, otherwise
4855 * the seqlock logic goes bad. We can not serialize this because the arch
4856 * code calls this from NMI context.
4858 void perf_event_update_userpage(struct perf_event
*event
)
4860 struct perf_event_mmap_page
*userpg
;
4861 struct ring_buffer
*rb
;
4862 u64 enabled
, running
, now
;
4865 rb
= rcu_dereference(event
->rb
);
4870 * compute total_time_enabled, total_time_running
4871 * based on snapshot values taken when the event
4872 * was last scheduled in.
4874 * we cannot simply called update_context_time()
4875 * because of locking issue as we can be called in
4878 calc_timer_values(event
, &now
, &enabled
, &running
);
4880 userpg
= rb
->user_page
;
4882 * Disable preemption so as to not let the corresponding user-space
4883 * spin too long if we get preempted.
4888 userpg
->index
= perf_event_index(event
);
4889 userpg
->offset
= perf_event_count(event
);
4891 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4893 userpg
->time_enabled
= enabled
+
4894 atomic64_read(&event
->child_total_time_enabled
);
4896 userpg
->time_running
= running
+
4897 atomic64_read(&event
->child_total_time_running
);
4899 arch_perf_update_userpage(event
, userpg
, now
);
4908 static int perf_mmap_fault(struct vm_fault
*vmf
)
4910 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4911 struct ring_buffer
*rb
;
4912 int ret
= VM_FAULT_SIGBUS
;
4914 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4915 if (vmf
->pgoff
== 0)
4921 rb
= rcu_dereference(event
->rb
);
4925 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4928 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4932 get_page(vmf
->page
);
4933 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4934 vmf
->page
->index
= vmf
->pgoff
;
4943 static void ring_buffer_attach(struct perf_event
*event
,
4944 struct ring_buffer
*rb
)
4946 struct ring_buffer
*old_rb
= NULL
;
4947 unsigned long flags
;
4951 * Should be impossible, we set this when removing
4952 * event->rb_entry and wait/clear when adding event->rb_entry.
4954 WARN_ON_ONCE(event
->rcu_pending
);
4957 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4958 list_del_rcu(&event
->rb_entry
);
4959 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4961 event
->rcu_batches
= get_state_synchronize_rcu();
4962 event
->rcu_pending
= 1;
4966 if (event
->rcu_pending
) {
4967 cond_synchronize_rcu(event
->rcu_batches
);
4968 event
->rcu_pending
= 0;
4971 spin_lock_irqsave(&rb
->event_lock
, flags
);
4972 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4973 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4977 * Avoid racing with perf_mmap_close(AUX): stop the event
4978 * before swizzling the event::rb pointer; if it's getting
4979 * unmapped, its aux_mmap_count will be 0 and it won't
4980 * restart. See the comment in __perf_pmu_output_stop().
4982 * Data will inevitably be lost when set_output is done in
4983 * mid-air, but then again, whoever does it like this is
4984 * not in for the data anyway.
4987 perf_event_stop(event
, 0);
4989 rcu_assign_pointer(event
->rb
, rb
);
4992 ring_buffer_put(old_rb
);
4994 * Since we detached before setting the new rb, so that we
4995 * could attach the new rb, we could have missed a wakeup.
4998 wake_up_all(&event
->waitq
);
5002 static void ring_buffer_wakeup(struct perf_event
*event
)
5004 struct ring_buffer
*rb
;
5007 rb
= rcu_dereference(event
->rb
);
5009 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5010 wake_up_all(&event
->waitq
);
5015 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5017 struct ring_buffer
*rb
;
5020 rb
= rcu_dereference(event
->rb
);
5022 if (!atomic_inc_not_zero(&rb
->refcount
))
5030 void ring_buffer_put(struct ring_buffer
*rb
)
5032 if (!atomic_dec_and_test(&rb
->refcount
))
5035 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5037 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5040 static void perf_mmap_open(struct vm_area_struct
*vma
)
5042 struct perf_event
*event
= vma
->vm_file
->private_data
;
5044 atomic_inc(&event
->mmap_count
);
5045 atomic_inc(&event
->rb
->mmap_count
);
5048 atomic_inc(&event
->rb
->aux_mmap_count
);
5050 if (event
->pmu
->event_mapped
)
5051 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5054 static void perf_pmu_output_stop(struct perf_event
*event
);
5057 * A buffer can be mmap()ed multiple times; either directly through the same
5058 * event, or through other events by use of perf_event_set_output().
5060 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5061 * the buffer here, where we still have a VM context. This means we need
5062 * to detach all events redirecting to us.
5064 static void perf_mmap_close(struct vm_area_struct
*vma
)
5066 struct perf_event
*event
= vma
->vm_file
->private_data
;
5068 struct ring_buffer
*rb
= ring_buffer_get(event
);
5069 struct user_struct
*mmap_user
= rb
->mmap_user
;
5070 int mmap_locked
= rb
->mmap_locked
;
5071 unsigned long size
= perf_data_size(rb
);
5073 if (event
->pmu
->event_unmapped
)
5074 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5077 * rb->aux_mmap_count will always drop before rb->mmap_count and
5078 * event->mmap_count, so it is ok to use event->mmap_mutex to
5079 * serialize with perf_mmap here.
5081 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5082 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5084 * Stop all AUX events that are writing to this buffer,
5085 * so that we can free its AUX pages and corresponding PMU
5086 * data. Note that after rb::aux_mmap_count dropped to zero,
5087 * they won't start any more (see perf_aux_output_begin()).
5089 perf_pmu_output_stop(event
);
5091 /* now it's safe to free the pages */
5092 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5093 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5095 /* this has to be the last one */
5097 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5099 mutex_unlock(&event
->mmap_mutex
);
5102 atomic_dec(&rb
->mmap_count
);
5104 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5107 ring_buffer_attach(event
, NULL
);
5108 mutex_unlock(&event
->mmap_mutex
);
5110 /* If there's still other mmap()s of this buffer, we're done. */
5111 if (atomic_read(&rb
->mmap_count
))
5115 * No other mmap()s, detach from all other events that might redirect
5116 * into the now unreachable buffer. Somewhat complicated by the
5117 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5121 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5122 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5124 * This event is en-route to free_event() which will
5125 * detach it and remove it from the list.
5131 mutex_lock(&event
->mmap_mutex
);
5133 * Check we didn't race with perf_event_set_output() which can
5134 * swizzle the rb from under us while we were waiting to
5135 * acquire mmap_mutex.
5137 * If we find a different rb; ignore this event, a next
5138 * iteration will no longer find it on the list. We have to
5139 * still restart the iteration to make sure we're not now
5140 * iterating the wrong list.
5142 if (event
->rb
== rb
)
5143 ring_buffer_attach(event
, NULL
);
5145 mutex_unlock(&event
->mmap_mutex
);
5149 * Restart the iteration; either we're on the wrong list or
5150 * destroyed its integrity by doing a deletion.
5157 * It could be there's still a few 0-ref events on the list; they'll
5158 * get cleaned up by free_event() -- they'll also still have their
5159 * ref on the rb and will free it whenever they are done with it.
5161 * Aside from that, this buffer is 'fully' detached and unmapped,
5162 * undo the VM accounting.
5165 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5166 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5167 free_uid(mmap_user
);
5170 ring_buffer_put(rb
); /* could be last */
5173 static const struct vm_operations_struct perf_mmap_vmops
= {
5174 .open
= perf_mmap_open
,
5175 .close
= perf_mmap_close
, /* non mergable */
5176 .fault
= perf_mmap_fault
,
5177 .page_mkwrite
= perf_mmap_fault
,
5180 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5182 struct perf_event
*event
= file
->private_data
;
5183 unsigned long user_locked
, user_lock_limit
;
5184 struct user_struct
*user
= current_user();
5185 unsigned long locked
, lock_limit
;
5186 struct ring_buffer
*rb
= NULL
;
5187 unsigned long vma_size
;
5188 unsigned long nr_pages
;
5189 long user_extra
= 0, extra
= 0;
5190 int ret
= 0, flags
= 0;
5193 * Don't allow mmap() of inherited per-task counters. This would
5194 * create a performance issue due to all children writing to the
5197 if (event
->cpu
== -1 && event
->attr
.inherit
)
5200 if (!(vma
->vm_flags
& VM_SHARED
))
5203 vma_size
= vma
->vm_end
- vma
->vm_start
;
5205 if (vma
->vm_pgoff
== 0) {
5206 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5209 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5210 * mapped, all subsequent mappings should have the same size
5211 * and offset. Must be above the normal perf buffer.
5213 u64 aux_offset
, aux_size
;
5218 nr_pages
= vma_size
/ PAGE_SIZE
;
5220 mutex_lock(&event
->mmap_mutex
);
5227 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5228 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5230 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5233 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5236 /* already mapped with a different offset */
5237 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5240 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5243 /* already mapped with a different size */
5244 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5247 if (!is_power_of_2(nr_pages
))
5250 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5253 if (rb_has_aux(rb
)) {
5254 atomic_inc(&rb
->aux_mmap_count
);
5259 atomic_set(&rb
->aux_mmap_count
, 1);
5260 user_extra
= nr_pages
;
5266 * If we have rb pages ensure they're a power-of-two number, so we
5267 * can do bitmasks instead of modulo.
5269 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5272 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5275 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5277 mutex_lock(&event
->mmap_mutex
);
5279 if (event
->rb
->nr_pages
!= nr_pages
) {
5284 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5286 * Raced against perf_mmap_close() through
5287 * perf_event_set_output(). Try again, hope for better
5290 mutex_unlock(&event
->mmap_mutex
);
5297 user_extra
= nr_pages
+ 1;
5300 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5303 * Increase the limit linearly with more CPUs:
5305 user_lock_limit
*= num_online_cpus();
5307 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5309 if (user_locked
> user_lock_limit
)
5310 extra
= user_locked
- user_lock_limit
;
5312 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5313 lock_limit
>>= PAGE_SHIFT
;
5314 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5316 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5317 !capable(CAP_IPC_LOCK
)) {
5322 WARN_ON(!rb
&& event
->rb
);
5324 if (vma
->vm_flags
& VM_WRITE
)
5325 flags
|= RING_BUFFER_WRITABLE
;
5328 rb
= rb_alloc(nr_pages
,
5329 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5337 atomic_set(&rb
->mmap_count
, 1);
5338 rb
->mmap_user
= get_current_user();
5339 rb
->mmap_locked
= extra
;
5341 ring_buffer_attach(event
, rb
);
5343 perf_event_init_userpage(event
);
5344 perf_event_update_userpage(event
);
5346 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5347 event
->attr
.aux_watermark
, flags
);
5349 rb
->aux_mmap_locked
= extra
;
5354 atomic_long_add(user_extra
, &user
->locked_vm
);
5355 vma
->vm_mm
->pinned_vm
+= extra
;
5357 atomic_inc(&event
->mmap_count
);
5359 atomic_dec(&rb
->mmap_count
);
5362 mutex_unlock(&event
->mmap_mutex
);
5365 * Since pinned accounting is per vm we cannot allow fork() to copy our
5368 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5369 vma
->vm_ops
= &perf_mmap_vmops
;
5371 if (event
->pmu
->event_mapped
)
5372 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5377 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5379 struct inode
*inode
= file_inode(filp
);
5380 struct perf_event
*event
= filp
->private_data
;
5384 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5385 inode_unlock(inode
);
5393 static const struct file_operations perf_fops
= {
5394 .llseek
= no_llseek
,
5395 .release
= perf_release
,
5398 .unlocked_ioctl
= perf_ioctl
,
5399 .compat_ioctl
= perf_compat_ioctl
,
5401 .fasync
= perf_fasync
,
5407 * If there's data, ensure we set the poll() state and publish everything
5408 * to user-space before waking everybody up.
5411 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5413 /* only the parent has fasync state */
5415 event
= event
->parent
;
5416 return &event
->fasync
;
5419 void perf_event_wakeup(struct perf_event
*event
)
5421 ring_buffer_wakeup(event
);
5423 if (event
->pending_kill
) {
5424 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5425 event
->pending_kill
= 0;
5429 static void perf_pending_event(struct irq_work
*entry
)
5431 struct perf_event
*event
= container_of(entry
,
5432 struct perf_event
, pending
);
5435 rctx
= perf_swevent_get_recursion_context();
5437 * If we 'fail' here, that's OK, it means recursion is already disabled
5438 * and we won't recurse 'further'.
5441 if (event
->pending_disable
) {
5442 event
->pending_disable
= 0;
5443 perf_event_disable_local(event
);
5446 if (event
->pending_wakeup
) {
5447 event
->pending_wakeup
= 0;
5448 perf_event_wakeup(event
);
5452 perf_swevent_put_recursion_context(rctx
);
5456 * We assume there is only KVM supporting the callbacks.
5457 * Later on, we might change it to a list if there is
5458 * another virtualization implementation supporting the callbacks.
5460 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5462 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5464 perf_guest_cbs
= cbs
;
5467 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5469 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5471 perf_guest_cbs
= NULL
;
5474 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5477 perf_output_sample_regs(struct perf_output_handle
*handle
,
5478 struct pt_regs
*regs
, u64 mask
)
5481 DECLARE_BITMAP(_mask
, 64);
5483 bitmap_from_u64(_mask
, mask
);
5484 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5487 val
= perf_reg_value(regs
, bit
);
5488 perf_output_put(handle
, val
);
5492 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5493 struct pt_regs
*regs
,
5494 struct pt_regs
*regs_user_copy
)
5496 if (user_mode(regs
)) {
5497 regs_user
->abi
= perf_reg_abi(current
);
5498 regs_user
->regs
= regs
;
5499 } else if (current
->mm
) {
5500 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5502 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5503 regs_user
->regs
= NULL
;
5507 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5508 struct pt_regs
*regs
)
5510 regs_intr
->regs
= regs
;
5511 regs_intr
->abi
= perf_reg_abi(current
);
5516 * Get remaining task size from user stack pointer.
5518 * It'd be better to take stack vma map and limit this more
5519 * precisly, but there's no way to get it safely under interrupt,
5520 * so using TASK_SIZE as limit.
5522 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5524 unsigned long addr
= perf_user_stack_pointer(regs
);
5526 if (!addr
|| addr
>= TASK_SIZE
)
5529 return TASK_SIZE
- addr
;
5533 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5534 struct pt_regs
*regs
)
5538 /* No regs, no stack pointer, no dump. */
5543 * Check if we fit in with the requested stack size into the:
5545 * If we don't, we limit the size to the TASK_SIZE.
5547 * - remaining sample size
5548 * If we don't, we customize the stack size to
5549 * fit in to the remaining sample size.
5552 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5553 stack_size
= min(stack_size
, (u16
) task_size
);
5555 /* Current header size plus static size and dynamic size. */
5556 header_size
+= 2 * sizeof(u64
);
5558 /* Do we fit in with the current stack dump size? */
5559 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5561 * If we overflow the maximum size for the sample,
5562 * we customize the stack dump size to fit in.
5564 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5565 stack_size
= round_up(stack_size
, sizeof(u64
));
5572 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5573 struct pt_regs
*regs
)
5575 /* Case of a kernel thread, nothing to dump */
5578 perf_output_put(handle
, size
);
5587 * - the size requested by user or the best one we can fit
5588 * in to the sample max size
5590 * - user stack dump data
5592 * - the actual dumped size
5596 perf_output_put(handle
, dump_size
);
5599 sp
= perf_user_stack_pointer(regs
);
5600 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5601 dyn_size
= dump_size
- rem
;
5603 perf_output_skip(handle
, rem
);
5606 perf_output_put(handle
, dyn_size
);
5610 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5611 struct perf_sample_data
*data
,
5612 struct perf_event
*event
)
5614 u64 sample_type
= event
->attr
.sample_type
;
5616 data
->type
= sample_type
;
5617 header
->size
+= event
->id_header_size
;
5619 if (sample_type
& PERF_SAMPLE_TID
) {
5620 /* namespace issues */
5621 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5622 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5625 if (sample_type
& PERF_SAMPLE_TIME
)
5626 data
->time
= perf_event_clock(event
);
5628 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5629 data
->id
= primary_event_id(event
);
5631 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5632 data
->stream_id
= event
->id
;
5634 if (sample_type
& PERF_SAMPLE_CPU
) {
5635 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5636 data
->cpu_entry
.reserved
= 0;
5640 void perf_event_header__init_id(struct perf_event_header
*header
,
5641 struct perf_sample_data
*data
,
5642 struct perf_event
*event
)
5644 if (event
->attr
.sample_id_all
)
5645 __perf_event_header__init_id(header
, data
, event
);
5648 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5649 struct perf_sample_data
*data
)
5651 u64 sample_type
= data
->type
;
5653 if (sample_type
& PERF_SAMPLE_TID
)
5654 perf_output_put(handle
, data
->tid_entry
);
5656 if (sample_type
& PERF_SAMPLE_TIME
)
5657 perf_output_put(handle
, data
->time
);
5659 if (sample_type
& PERF_SAMPLE_ID
)
5660 perf_output_put(handle
, data
->id
);
5662 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5663 perf_output_put(handle
, data
->stream_id
);
5665 if (sample_type
& PERF_SAMPLE_CPU
)
5666 perf_output_put(handle
, data
->cpu_entry
);
5668 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5669 perf_output_put(handle
, data
->id
);
5672 void perf_event__output_id_sample(struct perf_event
*event
,
5673 struct perf_output_handle
*handle
,
5674 struct perf_sample_data
*sample
)
5676 if (event
->attr
.sample_id_all
)
5677 __perf_event__output_id_sample(handle
, sample
);
5680 static void perf_output_read_one(struct perf_output_handle
*handle
,
5681 struct perf_event
*event
,
5682 u64 enabled
, u64 running
)
5684 u64 read_format
= event
->attr
.read_format
;
5688 values
[n
++] = perf_event_count(event
);
5689 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5690 values
[n
++] = enabled
+
5691 atomic64_read(&event
->child_total_time_enabled
);
5693 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5694 values
[n
++] = running
+
5695 atomic64_read(&event
->child_total_time_running
);
5697 if (read_format
& PERF_FORMAT_ID
)
5698 values
[n
++] = primary_event_id(event
);
5700 __output_copy(handle
, values
, n
* sizeof(u64
));
5703 static void perf_output_read_group(struct perf_output_handle
*handle
,
5704 struct perf_event
*event
,
5705 u64 enabled
, u64 running
)
5707 struct perf_event
*leader
= event
->group_leader
, *sub
;
5708 u64 read_format
= event
->attr
.read_format
;
5712 values
[n
++] = 1 + leader
->nr_siblings
;
5714 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5715 values
[n
++] = enabled
;
5717 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5718 values
[n
++] = running
;
5720 if (leader
!= event
)
5721 leader
->pmu
->read(leader
);
5723 values
[n
++] = perf_event_count(leader
);
5724 if (read_format
& PERF_FORMAT_ID
)
5725 values
[n
++] = primary_event_id(leader
);
5727 __output_copy(handle
, values
, n
* sizeof(u64
));
5729 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5732 if ((sub
!= event
) &&
5733 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5734 sub
->pmu
->read(sub
);
5736 values
[n
++] = perf_event_count(sub
);
5737 if (read_format
& PERF_FORMAT_ID
)
5738 values
[n
++] = primary_event_id(sub
);
5740 __output_copy(handle
, values
, n
* sizeof(u64
));
5744 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5745 PERF_FORMAT_TOTAL_TIME_RUNNING)
5748 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5750 * The problem is that its both hard and excessively expensive to iterate the
5751 * child list, not to mention that its impossible to IPI the children running
5752 * on another CPU, from interrupt/NMI context.
5754 static void perf_output_read(struct perf_output_handle
*handle
,
5755 struct perf_event
*event
)
5757 u64 enabled
= 0, running
= 0, now
;
5758 u64 read_format
= event
->attr
.read_format
;
5761 * compute total_time_enabled, total_time_running
5762 * based on snapshot values taken when the event
5763 * was last scheduled in.
5765 * we cannot simply called update_context_time()
5766 * because of locking issue as we are called in
5769 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5770 calc_timer_values(event
, &now
, &enabled
, &running
);
5772 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5773 perf_output_read_group(handle
, event
, enabled
, running
);
5775 perf_output_read_one(handle
, event
, enabled
, running
);
5778 void perf_output_sample(struct perf_output_handle
*handle
,
5779 struct perf_event_header
*header
,
5780 struct perf_sample_data
*data
,
5781 struct perf_event
*event
)
5783 u64 sample_type
= data
->type
;
5785 perf_output_put(handle
, *header
);
5787 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5788 perf_output_put(handle
, data
->id
);
5790 if (sample_type
& PERF_SAMPLE_IP
)
5791 perf_output_put(handle
, data
->ip
);
5793 if (sample_type
& PERF_SAMPLE_TID
)
5794 perf_output_put(handle
, data
->tid_entry
);
5796 if (sample_type
& PERF_SAMPLE_TIME
)
5797 perf_output_put(handle
, data
->time
);
5799 if (sample_type
& PERF_SAMPLE_ADDR
)
5800 perf_output_put(handle
, data
->addr
);
5802 if (sample_type
& PERF_SAMPLE_ID
)
5803 perf_output_put(handle
, data
->id
);
5805 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5806 perf_output_put(handle
, data
->stream_id
);
5808 if (sample_type
& PERF_SAMPLE_CPU
)
5809 perf_output_put(handle
, data
->cpu_entry
);
5811 if (sample_type
& PERF_SAMPLE_PERIOD
)
5812 perf_output_put(handle
, data
->period
);
5814 if (sample_type
& PERF_SAMPLE_READ
)
5815 perf_output_read(handle
, event
);
5817 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5818 if (data
->callchain
) {
5821 if (data
->callchain
)
5822 size
+= data
->callchain
->nr
;
5824 size
*= sizeof(u64
);
5826 __output_copy(handle
, data
->callchain
, size
);
5829 perf_output_put(handle
, nr
);
5833 if (sample_type
& PERF_SAMPLE_RAW
) {
5834 struct perf_raw_record
*raw
= data
->raw
;
5837 struct perf_raw_frag
*frag
= &raw
->frag
;
5839 perf_output_put(handle
, raw
->size
);
5842 __output_custom(handle
, frag
->copy
,
5843 frag
->data
, frag
->size
);
5845 __output_copy(handle
, frag
->data
,
5848 if (perf_raw_frag_last(frag
))
5853 __output_skip(handle
, NULL
, frag
->pad
);
5859 .size
= sizeof(u32
),
5862 perf_output_put(handle
, raw
);
5866 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5867 if (data
->br_stack
) {
5870 size
= data
->br_stack
->nr
5871 * sizeof(struct perf_branch_entry
);
5873 perf_output_put(handle
, data
->br_stack
->nr
);
5874 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5877 * we always store at least the value of nr
5880 perf_output_put(handle
, nr
);
5884 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5885 u64 abi
= data
->regs_user
.abi
;
5888 * If there are no regs to dump, notice it through
5889 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5891 perf_output_put(handle
, abi
);
5894 u64 mask
= event
->attr
.sample_regs_user
;
5895 perf_output_sample_regs(handle
,
5896 data
->regs_user
.regs
,
5901 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5902 perf_output_sample_ustack(handle
,
5903 data
->stack_user_size
,
5904 data
->regs_user
.regs
);
5907 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5908 perf_output_put(handle
, data
->weight
);
5910 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5911 perf_output_put(handle
, data
->data_src
.val
);
5913 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5914 perf_output_put(handle
, data
->txn
);
5916 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5917 u64 abi
= data
->regs_intr
.abi
;
5919 * If there are no regs to dump, notice it through
5920 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5922 perf_output_put(handle
, abi
);
5925 u64 mask
= event
->attr
.sample_regs_intr
;
5927 perf_output_sample_regs(handle
,
5928 data
->regs_intr
.regs
,
5933 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
5934 perf_output_put(handle
, data
->phys_addr
);
5936 if (!event
->attr
.watermark
) {
5937 int wakeup_events
= event
->attr
.wakeup_events
;
5939 if (wakeup_events
) {
5940 struct ring_buffer
*rb
= handle
->rb
;
5941 int events
= local_inc_return(&rb
->events
);
5943 if (events
>= wakeup_events
) {
5944 local_sub(wakeup_events
, &rb
->events
);
5945 local_inc(&rb
->wakeup
);
5951 static u64
perf_virt_to_phys(u64 virt
)
5954 struct page
*p
= NULL
;
5959 if (virt
>= TASK_SIZE
) {
5960 /* If it's vmalloc()d memory, leave phys_addr as 0 */
5961 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
5962 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
5963 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
5966 * Walking the pages tables for user address.
5967 * Interrupts are disabled, so it prevents any tear down
5968 * of the page tables.
5969 * Try IRQ-safe __get_user_pages_fast first.
5970 * If failed, leave phys_addr as 0.
5972 if ((current
->mm
!= NULL
) &&
5973 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
5974 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
5983 void perf_prepare_sample(struct perf_event_header
*header
,
5984 struct perf_sample_data
*data
,
5985 struct perf_event
*event
,
5986 struct pt_regs
*regs
)
5988 u64 sample_type
= event
->attr
.sample_type
;
5990 header
->type
= PERF_RECORD_SAMPLE
;
5991 header
->size
= sizeof(*header
) + event
->header_size
;
5994 header
->misc
|= perf_misc_flags(regs
);
5996 __perf_event_header__init_id(header
, data
, event
);
5998 if (sample_type
& PERF_SAMPLE_IP
)
5999 data
->ip
= perf_instruction_pointer(regs
);
6001 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6004 data
->callchain
= perf_callchain(event
, regs
);
6006 if (data
->callchain
)
6007 size
+= data
->callchain
->nr
;
6009 header
->size
+= size
* sizeof(u64
);
6012 if (sample_type
& PERF_SAMPLE_RAW
) {
6013 struct perf_raw_record
*raw
= data
->raw
;
6017 struct perf_raw_frag
*frag
= &raw
->frag
;
6022 if (perf_raw_frag_last(frag
))
6027 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6028 raw
->size
= size
- sizeof(u32
);
6029 frag
->pad
= raw
->size
- sum
;
6034 header
->size
+= size
;
6037 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6038 int size
= sizeof(u64
); /* nr */
6039 if (data
->br_stack
) {
6040 size
+= data
->br_stack
->nr
6041 * sizeof(struct perf_branch_entry
);
6043 header
->size
+= size
;
6046 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6047 perf_sample_regs_user(&data
->regs_user
, regs
,
6048 &data
->regs_user_copy
);
6050 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6051 /* regs dump ABI info */
6052 int size
= sizeof(u64
);
6054 if (data
->regs_user
.regs
) {
6055 u64 mask
= event
->attr
.sample_regs_user
;
6056 size
+= hweight64(mask
) * sizeof(u64
);
6059 header
->size
+= size
;
6062 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6064 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6065 * processed as the last one or have additional check added
6066 * in case new sample type is added, because we could eat
6067 * up the rest of the sample size.
6069 u16 stack_size
= event
->attr
.sample_stack_user
;
6070 u16 size
= sizeof(u64
);
6072 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6073 data
->regs_user
.regs
);
6076 * If there is something to dump, add space for the dump
6077 * itself and for the field that tells the dynamic size,
6078 * which is how many have been actually dumped.
6081 size
+= sizeof(u64
) + stack_size
;
6083 data
->stack_user_size
= stack_size
;
6084 header
->size
+= size
;
6087 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6088 /* regs dump ABI info */
6089 int size
= sizeof(u64
);
6091 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6093 if (data
->regs_intr
.regs
) {
6094 u64 mask
= event
->attr
.sample_regs_intr
;
6096 size
+= hweight64(mask
) * sizeof(u64
);
6099 header
->size
+= size
;
6102 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6103 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6106 static void __always_inline
6107 __perf_event_output(struct perf_event
*event
,
6108 struct perf_sample_data
*data
,
6109 struct pt_regs
*regs
,
6110 int (*output_begin
)(struct perf_output_handle
*,
6111 struct perf_event
*,
6114 struct perf_output_handle handle
;
6115 struct perf_event_header header
;
6117 /* protect the callchain buffers */
6120 perf_prepare_sample(&header
, data
, event
, regs
);
6122 if (output_begin(&handle
, event
, header
.size
))
6125 perf_output_sample(&handle
, &header
, data
, event
);
6127 perf_output_end(&handle
);
6134 perf_event_output_forward(struct perf_event
*event
,
6135 struct perf_sample_data
*data
,
6136 struct pt_regs
*regs
)
6138 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6142 perf_event_output_backward(struct perf_event
*event
,
6143 struct perf_sample_data
*data
,
6144 struct pt_regs
*regs
)
6146 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6150 perf_event_output(struct perf_event
*event
,
6151 struct perf_sample_data
*data
,
6152 struct pt_regs
*regs
)
6154 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6161 struct perf_read_event
{
6162 struct perf_event_header header
;
6169 perf_event_read_event(struct perf_event
*event
,
6170 struct task_struct
*task
)
6172 struct perf_output_handle handle
;
6173 struct perf_sample_data sample
;
6174 struct perf_read_event read_event
= {
6176 .type
= PERF_RECORD_READ
,
6178 .size
= sizeof(read_event
) + event
->read_size
,
6180 .pid
= perf_event_pid(event
, task
),
6181 .tid
= perf_event_tid(event
, task
),
6185 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6186 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6190 perf_output_put(&handle
, read_event
);
6191 perf_output_read(&handle
, event
);
6192 perf_event__output_id_sample(event
, &handle
, &sample
);
6194 perf_output_end(&handle
);
6197 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6200 perf_iterate_ctx(struct perf_event_context
*ctx
,
6201 perf_iterate_f output
,
6202 void *data
, bool all
)
6204 struct perf_event
*event
;
6206 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6208 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6210 if (!event_filter_match(event
))
6214 output(event
, data
);
6218 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6220 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6221 struct perf_event
*event
;
6223 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6225 * Skip events that are not fully formed yet; ensure that
6226 * if we observe event->ctx, both event and ctx will be
6227 * complete enough. See perf_install_in_context().
6229 if (!smp_load_acquire(&event
->ctx
))
6232 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6234 if (!event_filter_match(event
))
6236 output(event
, data
);
6241 * Iterate all events that need to receive side-band events.
6243 * For new callers; ensure that account_pmu_sb_event() includes
6244 * your event, otherwise it might not get delivered.
6247 perf_iterate_sb(perf_iterate_f output
, void *data
,
6248 struct perf_event_context
*task_ctx
)
6250 struct perf_event_context
*ctx
;
6257 * If we have task_ctx != NULL we only notify the task context itself.
6258 * The task_ctx is set only for EXIT events before releasing task
6262 perf_iterate_ctx(task_ctx
, output
, data
, false);
6266 perf_iterate_sb_cpu(output
, data
);
6268 for_each_task_context_nr(ctxn
) {
6269 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6271 perf_iterate_ctx(ctx
, output
, data
, false);
6279 * Clear all file-based filters at exec, they'll have to be
6280 * re-instated when/if these objects are mmapped again.
6282 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6284 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6285 struct perf_addr_filter
*filter
;
6286 unsigned int restart
= 0, count
= 0;
6287 unsigned long flags
;
6289 if (!has_addr_filter(event
))
6292 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6293 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6294 if (filter
->inode
) {
6295 event
->addr_filters_offs
[count
] = 0;
6303 event
->addr_filters_gen
++;
6304 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6307 perf_event_stop(event
, 1);
6310 void perf_event_exec(void)
6312 struct perf_event_context
*ctx
;
6316 for_each_task_context_nr(ctxn
) {
6317 ctx
= current
->perf_event_ctxp
[ctxn
];
6321 perf_event_enable_on_exec(ctxn
);
6323 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6329 struct remote_output
{
6330 struct ring_buffer
*rb
;
6334 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6336 struct perf_event
*parent
= event
->parent
;
6337 struct remote_output
*ro
= data
;
6338 struct ring_buffer
*rb
= ro
->rb
;
6339 struct stop_event_data sd
= {
6343 if (!has_aux(event
))
6350 * In case of inheritance, it will be the parent that links to the
6351 * ring-buffer, but it will be the child that's actually using it.
6353 * We are using event::rb to determine if the event should be stopped,
6354 * however this may race with ring_buffer_attach() (through set_output),
6355 * which will make us skip the event that actually needs to be stopped.
6356 * So ring_buffer_attach() has to stop an aux event before re-assigning
6359 if (rcu_dereference(parent
->rb
) == rb
)
6360 ro
->err
= __perf_event_stop(&sd
);
6363 static int __perf_pmu_output_stop(void *info
)
6365 struct perf_event
*event
= info
;
6366 struct pmu
*pmu
= event
->pmu
;
6367 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6368 struct remote_output ro
= {
6373 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6374 if (cpuctx
->task_ctx
)
6375 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6382 static void perf_pmu_output_stop(struct perf_event
*event
)
6384 struct perf_event
*iter
;
6389 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6391 * For per-CPU events, we need to make sure that neither they
6392 * nor their children are running; for cpu==-1 events it's
6393 * sufficient to stop the event itself if it's active, since
6394 * it can't have children.
6398 cpu
= READ_ONCE(iter
->oncpu
);
6403 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6404 if (err
== -EAGAIN
) {
6413 * task tracking -- fork/exit
6415 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6418 struct perf_task_event
{
6419 struct task_struct
*task
;
6420 struct perf_event_context
*task_ctx
;
6423 struct perf_event_header header
;
6433 static int perf_event_task_match(struct perf_event
*event
)
6435 return event
->attr
.comm
|| event
->attr
.mmap
||
6436 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6440 static void perf_event_task_output(struct perf_event
*event
,
6443 struct perf_task_event
*task_event
= data
;
6444 struct perf_output_handle handle
;
6445 struct perf_sample_data sample
;
6446 struct task_struct
*task
= task_event
->task
;
6447 int ret
, size
= task_event
->event_id
.header
.size
;
6449 if (!perf_event_task_match(event
))
6452 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6454 ret
= perf_output_begin(&handle
, event
,
6455 task_event
->event_id
.header
.size
);
6459 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6460 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6462 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6463 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6465 task_event
->event_id
.time
= perf_event_clock(event
);
6467 perf_output_put(&handle
, task_event
->event_id
);
6469 perf_event__output_id_sample(event
, &handle
, &sample
);
6471 perf_output_end(&handle
);
6473 task_event
->event_id
.header
.size
= size
;
6476 static void perf_event_task(struct task_struct
*task
,
6477 struct perf_event_context
*task_ctx
,
6480 struct perf_task_event task_event
;
6482 if (!atomic_read(&nr_comm_events
) &&
6483 !atomic_read(&nr_mmap_events
) &&
6484 !atomic_read(&nr_task_events
))
6487 task_event
= (struct perf_task_event
){
6489 .task_ctx
= task_ctx
,
6492 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6494 .size
= sizeof(task_event
.event_id
),
6504 perf_iterate_sb(perf_event_task_output
,
6509 void perf_event_fork(struct task_struct
*task
)
6511 perf_event_task(task
, NULL
, 1);
6512 perf_event_namespaces(task
);
6519 struct perf_comm_event
{
6520 struct task_struct
*task
;
6525 struct perf_event_header header
;
6532 static int perf_event_comm_match(struct perf_event
*event
)
6534 return event
->attr
.comm
;
6537 static void perf_event_comm_output(struct perf_event
*event
,
6540 struct perf_comm_event
*comm_event
= data
;
6541 struct perf_output_handle handle
;
6542 struct perf_sample_data sample
;
6543 int size
= comm_event
->event_id
.header
.size
;
6546 if (!perf_event_comm_match(event
))
6549 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6550 ret
= perf_output_begin(&handle
, event
,
6551 comm_event
->event_id
.header
.size
);
6556 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6557 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6559 perf_output_put(&handle
, comm_event
->event_id
);
6560 __output_copy(&handle
, comm_event
->comm
,
6561 comm_event
->comm_size
);
6563 perf_event__output_id_sample(event
, &handle
, &sample
);
6565 perf_output_end(&handle
);
6567 comm_event
->event_id
.header
.size
= size
;
6570 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6572 char comm
[TASK_COMM_LEN
];
6575 memset(comm
, 0, sizeof(comm
));
6576 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6577 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6579 comm_event
->comm
= comm
;
6580 comm_event
->comm_size
= size
;
6582 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6584 perf_iterate_sb(perf_event_comm_output
,
6589 void perf_event_comm(struct task_struct
*task
, bool exec
)
6591 struct perf_comm_event comm_event
;
6593 if (!atomic_read(&nr_comm_events
))
6596 comm_event
= (struct perf_comm_event
){
6602 .type
= PERF_RECORD_COMM
,
6603 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6611 perf_event_comm_event(&comm_event
);
6615 * namespaces tracking
6618 struct perf_namespaces_event
{
6619 struct task_struct
*task
;
6622 struct perf_event_header header
;
6627 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6631 static int perf_event_namespaces_match(struct perf_event
*event
)
6633 return event
->attr
.namespaces
;
6636 static void perf_event_namespaces_output(struct perf_event
*event
,
6639 struct perf_namespaces_event
*namespaces_event
= data
;
6640 struct perf_output_handle handle
;
6641 struct perf_sample_data sample
;
6644 if (!perf_event_namespaces_match(event
))
6647 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6649 ret
= perf_output_begin(&handle
, event
,
6650 namespaces_event
->event_id
.header
.size
);
6654 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6655 namespaces_event
->task
);
6656 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6657 namespaces_event
->task
);
6659 perf_output_put(&handle
, namespaces_event
->event_id
);
6661 perf_event__output_id_sample(event
, &handle
, &sample
);
6663 perf_output_end(&handle
);
6666 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6667 struct task_struct
*task
,
6668 const struct proc_ns_operations
*ns_ops
)
6670 struct path ns_path
;
6671 struct inode
*ns_inode
;
6674 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6676 ns_inode
= ns_path
.dentry
->d_inode
;
6677 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6678 ns_link_info
->ino
= ns_inode
->i_ino
;
6683 void perf_event_namespaces(struct task_struct
*task
)
6685 struct perf_namespaces_event namespaces_event
;
6686 struct perf_ns_link_info
*ns_link_info
;
6688 if (!atomic_read(&nr_namespaces_events
))
6691 namespaces_event
= (struct perf_namespaces_event
){
6695 .type
= PERF_RECORD_NAMESPACES
,
6697 .size
= sizeof(namespaces_event
.event_id
),
6701 .nr_namespaces
= NR_NAMESPACES
,
6702 /* .link_info[NR_NAMESPACES] */
6706 ns_link_info
= namespaces_event
.event_id
.link_info
;
6708 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6709 task
, &mntns_operations
);
6711 #ifdef CONFIG_USER_NS
6712 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6713 task
, &userns_operations
);
6715 #ifdef CONFIG_NET_NS
6716 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6717 task
, &netns_operations
);
6719 #ifdef CONFIG_UTS_NS
6720 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6721 task
, &utsns_operations
);
6723 #ifdef CONFIG_IPC_NS
6724 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6725 task
, &ipcns_operations
);
6727 #ifdef CONFIG_PID_NS
6728 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6729 task
, &pidns_operations
);
6731 #ifdef CONFIG_CGROUPS
6732 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6733 task
, &cgroupns_operations
);
6736 perf_iterate_sb(perf_event_namespaces_output
,
6745 struct perf_mmap_event
{
6746 struct vm_area_struct
*vma
;
6748 const char *file_name
;
6756 struct perf_event_header header
;
6766 static int perf_event_mmap_match(struct perf_event
*event
,
6769 struct perf_mmap_event
*mmap_event
= data
;
6770 struct vm_area_struct
*vma
= mmap_event
->vma
;
6771 int executable
= vma
->vm_flags
& VM_EXEC
;
6773 return (!executable
&& event
->attr
.mmap_data
) ||
6774 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6777 static void perf_event_mmap_output(struct perf_event
*event
,
6780 struct perf_mmap_event
*mmap_event
= data
;
6781 struct perf_output_handle handle
;
6782 struct perf_sample_data sample
;
6783 int size
= mmap_event
->event_id
.header
.size
;
6786 if (!perf_event_mmap_match(event
, data
))
6789 if (event
->attr
.mmap2
) {
6790 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6791 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6792 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6793 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6794 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6795 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6796 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6799 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6800 ret
= perf_output_begin(&handle
, event
,
6801 mmap_event
->event_id
.header
.size
);
6805 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6806 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6808 perf_output_put(&handle
, mmap_event
->event_id
);
6810 if (event
->attr
.mmap2
) {
6811 perf_output_put(&handle
, mmap_event
->maj
);
6812 perf_output_put(&handle
, mmap_event
->min
);
6813 perf_output_put(&handle
, mmap_event
->ino
);
6814 perf_output_put(&handle
, mmap_event
->ino_generation
);
6815 perf_output_put(&handle
, mmap_event
->prot
);
6816 perf_output_put(&handle
, mmap_event
->flags
);
6819 __output_copy(&handle
, mmap_event
->file_name
,
6820 mmap_event
->file_size
);
6822 perf_event__output_id_sample(event
, &handle
, &sample
);
6824 perf_output_end(&handle
);
6826 mmap_event
->event_id
.header
.size
= size
;
6829 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6831 struct vm_area_struct
*vma
= mmap_event
->vma
;
6832 struct file
*file
= vma
->vm_file
;
6833 int maj
= 0, min
= 0;
6834 u64 ino
= 0, gen
= 0;
6835 u32 prot
= 0, flags
= 0;
6841 if (vma
->vm_flags
& VM_READ
)
6843 if (vma
->vm_flags
& VM_WRITE
)
6845 if (vma
->vm_flags
& VM_EXEC
)
6848 if (vma
->vm_flags
& VM_MAYSHARE
)
6851 flags
= MAP_PRIVATE
;
6853 if (vma
->vm_flags
& VM_DENYWRITE
)
6854 flags
|= MAP_DENYWRITE
;
6855 if (vma
->vm_flags
& VM_MAYEXEC
)
6856 flags
|= MAP_EXECUTABLE
;
6857 if (vma
->vm_flags
& VM_LOCKED
)
6858 flags
|= MAP_LOCKED
;
6859 if (vma
->vm_flags
& VM_HUGETLB
)
6860 flags
|= MAP_HUGETLB
;
6863 struct inode
*inode
;
6866 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6872 * d_path() works from the end of the rb backwards, so we
6873 * need to add enough zero bytes after the string to handle
6874 * the 64bit alignment we do later.
6876 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6881 inode
= file_inode(vma
->vm_file
);
6882 dev
= inode
->i_sb
->s_dev
;
6884 gen
= inode
->i_generation
;
6890 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6891 name
= (char *) vma
->vm_ops
->name(vma
);
6896 name
= (char *)arch_vma_name(vma
);
6900 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6901 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6905 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6906 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6916 strlcpy(tmp
, name
, sizeof(tmp
));
6920 * Since our buffer works in 8 byte units we need to align our string
6921 * size to a multiple of 8. However, we must guarantee the tail end is
6922 * zero'd out to avoid leaking random bits to userspace.
6924 size
= strlen(name
)+1;
6925 while (!IS_ALIGNED(size
, sizeof(u64
)))
6926 name
[size
++] = '\0';
6928 mmap_event
->file_name
= name
;
6929 mmap_event
->file_size
= size
;
6930 mmap_event
->maj
= maj
;
6931 mmap_event
->min
= min
;
6932 mmap_event
->ino
= ino
;
6933 mmap_event
->ino_generation
= gen
;
6934 mmap_event
->prot
= prot
;
6935 mmap_event
->flags
= flags
;
6937 if (!(vma
->vm_flags
& VM_EXEC
))
6938 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6940 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6942 perf_iterate_sb(perf_event_mmap_output
,
6950 * Check whether inode and address range match filter criteria.
6952 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6953 struct file
*file
, unsigned long offset
,
6956 if (filter
->inode
!= file_inode(file
))
6959 if (filter
->offset
> offset
+ size
)
6962 if (filter
->offset
+ filter
->size
< offset
)
6968 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6970 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6971 struct vm_area_struct
*vma
= data
;
6972 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6973 struct file
*file
= vma
->vm_file
;
6974 struct perf_addr_filter
*filter
;
6975 unsigned int restart
= 0, count
= 0;
6977 if (!has_addr_filter(event
))
6983 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6984 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6985 if (perf_addr_filter_match(filter
, file
, off
,
6986 vma
->vm_end
- vma
->vm_start
)) {
6987 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6995 event
->addr_filters_gen
++;
6996 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6999 perf_event_stop(event
, 1);
7003 * Adjust all task's events' filters to the new vma
7005 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7007 struct perf_event_context
*ctx
;
7011 * Data tracing isn't supported yet and as such there is no need
7012 * to keep track of anything that isn't related to executable code:
7014 if (!(vma
->vm_flags
& VM_EXEC
))
7018 for_each_task_context_nr(ctxn
) {
7019 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7023 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7028 void perf_event_mmap(struct vm_area_struct
*vma
)
7030 struct perf_mmap_event mmap_event
;
7032 if (!atomic_read(&nr_mmap_events
))
7035 mmap_event
= (struct perf_mmap_event
){
7041 .type
= PERF_RECORD_MMAP
,
7042 .misc
= PERF_RECORD_MISC_USER
,
7047 .start
= vma
->vm_start
,
7048 .len
= vma
->vm_end
- vma
->vm_start
,
7049 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7051 /* .maj (attr_mmap2 only) */
7052 /* .min (attr_mmap2 only) */
7053 /* .ino (attr_mmap2 only) */
7054 /* .ino_generation (attr_mmap2 only) */
7055 /* .prot (attr_mmap2 only) */
7056 /* .flags (attr_mmap2 only) */
7059 perf_addr_filters_adjust(vma
);
7060 perf_event_mmap_event(&mmap_event
);
7063 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7064 unsigned long size
, u64 flags
)
7066 struct perf_output_handle handle
;
7067 struct perf_sample_data sample
;
7068 struct perf_aux_event
{
7069 struct perf_event_header header
;
7075 .type
= PERF_RECORD_AUX
,
7077 .size
= sizeof(rec
),
7085 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7086 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7091 perf_output_put(&handle
, rec
);
7092 perf_event__output_id_sample(event
, &handle
, &sample
);
7094 perf_output_end(&handle
);
7098 * Lost/dropped samples logging
7100 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7102 struct perf_output_handle handle
;
7103 struct perf_sample_data sample
;
7107 struct perf_event_header header
;
7109 } lost_samples_event
= {
7111 .type
= PERF_RECORD_LOST_SAMPLES
,
7113 .size
= sizeof(lost_samples_event
),
7118 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7120 ret
= perf_output_begin(&handle
, event
,
7121 lost_samples_event
.header
.size
);
7125 perf_output_put(&handle
, lost_samples_event
);
7126 perf_event__output_id_sample(event
, &handle
, &sample
);
7127 perf_output_end(&handle
);
7131 * context_switch tracking
7134 struct perf_switch_event
{
7135 struct task_struct
*task
;
7136 struct task_struct
*next_prev
;
7139 struct perf_event_header header
;
7145 static int perf_event_switch_match(struct perf_event
*event
)
7147 return event
->attr
.context_switch
;
7150 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7152 struct perf_switch_event
*se
= data
;
7153 struct perf_output_handle handle
;
7154 struct perf_sample_data sample
;
7157 if (!perf_event_switch_match(event
))
7160 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7161 if (event
->ctx
->task
) {
7162 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7163 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7165 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7166 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7167 se
->event_id
.next_prev_pid
=
7168 perf_event_pid(event
, se
->next_prev
);
7169 se
->event_id
.next_prev_tid
=
7170 perf_event_tid(event
, se
->next_prev
);
7173 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7175 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7179 if (event
->ctx
->task
)
7180 perf_output_put(&handle
, se
->event_id
.header
);
7182 perf_output_put(&handle
, se
->event_id
);
7184 perf_event__output_id_sample(event
, &handle
, &sample
);
7186 perf_output_end(&handle
);
7189 static void perf_event_switch(struct task_struct
*task
,
7190 struct task_struct
*next_prev
, bool sched_in
)
7192 struct perf_switch_event switch_event
;
7194 /* N.B. caller checks nr_switch_events != 0 */
7196 switch_event
= (struct perf_switch_event
){
7198 .next_prev
= next_prev
,
7202 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7205 /* .next_prev_pid */
7206 /* .next_prev_tid */
7210 perf_iterate_sb(perf_event_switch_output
,
7216 * IRQ throttle logging
7219 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7221 struct perf_output_handle handle
;
7222 struct perf_sample_data sample
;
7226 struct perf_event_header header
;
7230 } throttle_event
= {
7232 .type
= PERF_RECORD_THROTTLE
,
7234 .size
= sizeof(throttle_event
),
7236 .time
= perf_event_clock(event
),
7237 .id
= primary_event_id(event
),
7238 .stream_id
= event
->id
,
7242 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7244 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7246 ret
= perf_output_begin(&handle
, event
,
7247 throttle_event
.header
.size
);
7251 perf_output_put(&handle
, throttle_event
);
7252 perf_event__output_id_sample(event
, &handle
, &sample
);
7253 perf_output_end(&handle
);
7256 void perf_event_itrace_started(struct perf_event
*event
)
7258 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7261 static void perf_log_itrace_start(struct perf_event
*event
)
7263 struct perf_output_handle handle
;
7264 struct perf_sample_data sample
;
7265 struct perf_aux_event
{
7266 struct perf_event_header header
;
7273 event
= event
->parent
;
7275 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7276 event
->attach_state
& PERF_ATTACH_ITRACE
)
7279 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7280 rec
.header
.misc
= 0;
7281 rec
.header
.size
= sizeof(rec
);
7282 rec
.pid
= perf_event_pid(event
, current
);
7283 rec
.tid
= perf_event_tid(event
, current
);
7285 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7286 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7291 perf_output_put(&handle
, rec
);
7292 perf_event__output_id_sample(event
, &handle
, &sample
);
7294 perf_output_end(&handle
);
7298 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7300 struct hw_perf_event
*hwc
= &event
->hw
;
7304 seq
= __this_cpu_read(perf_throttled_seq
);
7305 if (seq
!= hwc
->interrupts_seq
) {
7306 hwc
->interrupts_seq
= seq
;
7307 hwc
->interrupts
= 1;
7310 if (unlikely(throttle
7311 && hwc
->interrupts
>= max_samples_per_tick
)) {
7312 __this_cpu_inc(perf_throttled_count
);
7313 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7314 hwc
->interrupts
= MAX_INTERRUPTS
;
7315 perf_log_throttle(event
, 0);
7320 if (event
->attr
.freq
) {
7321 u64 now
= perf_clock();
7322 s64 delta
= now
- hwc
->freq_time_stamp
;
7324 hwc
->freq_time_stamp
= now
;
7326 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7327 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7333 int perf_event_account_interrupt(struct perf_event
*event
)
7335 return __perf_event_account_interrupt(event
, 1);
7339 * Generic event overflow handling, sampling.
7342 static int __perf_event_overflow(struct perf_event
*event
,
7343 int throttle
, struct perf_sample_data
*data
,
7344 struct pt_regs
*regs
)
7346 int events
= atomic_read(&event
->event_limit
);
7350 * Non-sampling counters might still use the PMI to fold short
7351 * hardware counters, ignore those.
7353 if (unlikely(!is_sampling_event(event
)))
7356 ret
= __perf_event_account_interrupt(event
, throttle
);
7359 * XXX event_limit might not quite work as expected on inherited
7363 event
->pending_kill
= POLL_IN
;
7364 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7366 event
->pending_kill
= POLL_HUP
;
7368 perf_event_disable_inatomic(event
);
7371 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7373 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7374 event
->pending_wakeup
= 1;
7375 irq_work_queue(&event
->pending
);
7381 int perf_event_overflow(struct perf_event
*event
,
7382 struct perf_sample_data
*data
,
7383 struct pt_regs
*regs
)
7385 return __perf_event_overflow(event
, 1, data
, regs
);
7389 * Generic software event infrastructure
7392 struct swevent_htable
{
7393 struct swevent_hlist
*swevent_hlist
;
7394 struct mutex hlist_mutex
;
7397 /* Recursion avoidance in each contexts */
7398 int recursion
[PERF_NR_CONTEXTS
];
7401 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7404 * We directly increment event->count and keep a second value in
7405 * event->hw.period_left to count intervals. This period event
7406 * is kept in the range [-sample_period, 0] so that we can use the
7410 u64
perf_swevent_set_period(struct perf_event
*event
)
7412 struct hw_perf_event
*hwc
= &event
->hw
;
7413 u64 period
= hwc
->last_period
;
7417 hwc
->last_period
= hwc
->sample_period
;
7420 old
= val
= local64_read(&hwc
->period_left
);
7424 nr
= div64_u64(period
+ val
, period
);
7425 offset
= nr
* period
;
7427 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7433 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7434 struct perf_sample_data
*data
,
7435 struct pt_regs
*regs
)
7437 struct hw_perf_event
*hwc
= &event
->hw
;
7441 overflow
= perf_swevent_set_period(event
);
7443 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7446 for (; overflow
; overflow
--) {
7447 if (__perf_event_overflow(event
, throttle
,
7450 * We inhibit the overflow from happening when
7451 * hwc->interrupts == MAX_INTERRUPTS.
7459 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7460 struct perf_sample_data
*data
,
7461 struct pt_regs
*regs
)
7463 struct hw_perf_event
*hwc
= &event
->hw
;
7465 local64_add(nr
, &event
->count
);
7470 if (!is_sampling_event(event
))
7473 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7475 return perf_swevent_overflow(event
, 1, data
, regs
);
7477 data
->period
= event
->hw
.last_period
;
7479 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7480 return perf_swevent_overflow(event
, 1, data
, regs
);
7482 if (local64_add_negative(nr
, &hwc
->period_left
))
7485 perf_swevent_overflow(event
, 0, data
, regs
);
7488 static int perf_exclude_event(struct perf_event
*event
,
7489 struct pt_regs
*regs
)
7491 if (event
->hw
.state
& PERF_HES_STOPPED
)
7495 if (event
->attr
.exclude_user
&& user_mode(regs
))
7498 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7505 static int perf_swevent_match(struct perf_event
*event
,
7506 enum perf_type_id type
,
7508 struct perf_sample_data
*data
,
7509 struct pt_regs
*regs
)
7511 if (event
->attr
.type
!= type
)
7514 if (event
->attr
.config
!= event_id
)
7517 if (perf_exclude_event(event
, regs
))
7523 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7525 u64 val
= event_id
| (type
<< 32);
7527 return hash_64(val
, SWEVENT_HLIST_BITS
);
7530 static inline struct hlist_head
*
7531 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7533 u64 hash
= swevent_hash(type
, event_id
);
7535 return &hlist
->heads
[hash
];
7538 /* For the read side: events when they trigger */
7539 static inline struct hlist_head
*
7540 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7542 struct swevent_hlist
*hlist
;
7544 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7548 return __find_swevent_head(hlist
, type
, event_id
);
7551 /* For the event head insertion and removal in the hlist */
7552 static inline struct hlist_head
*
7553 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7555 struct swevent_hlist
*hlist
;
7556 u32 event_id
= event
->attr
.config
;
7557 u64 type
= event
->attr
.type
;
7560 * Event scheduling is always serialized against hlist allocation
7561 * and release. Which makes the protected version suitable here.
7562 * The context lock guarantees that.
7564 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7565 lockdep_is_held(&event
->ctx
->lock
));
7569 return __find_swevent_head(hlist
, type
, event_id
);
7572 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7574 struct perf_sample_data
*data
,
7575 struct pt_regs
*regs
)
7577 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7578 struct perf_event
*event
;
7579 struct hlist_head
*head
;
7582 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7586 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7587 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7588 perf_swevent_event(event
, nr
, data
, regs
);
7594 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7596 int perf_swevent_get_recursion_context(void)
7598 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7600 return get_recursion_context(swhash
->recursion
);
7602 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7604 void perf_swevent_put_recursion_context(int rctx
)
7606 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7608 put_recursion_context(swhash
->recursion
, rctx
);
7611 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7613 struct perf_sample_data data
;
7615 if (WARN_ON_ONCE(!regs
))
7618 perf_sample_data_init(&data
, addr
, 0);
7619 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7622 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7626 preempt_disable_notrace();
7627 rctx
= perf_swevent_get_recursion_context();
7628 if (unlikely(rctx
< 0))
7631 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7633 perf_swevent_put_recursion_context(rctx
);
7635 preempt_enable_notrace();
7638 static void perf_swevent_read(struct perf_event
*event
)
7642 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7644 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7645 struct hw_perf_event
*hwc
= &event
->hw
;
7646 struct hlist_head
*head
;
7648 if (is_sampling_event(event
)) {
7649 hwc
->last_period
= hwc
->sample_period
;
7650 perf_swevent_set_period(event
);
7653 hwc
->state
= !(flags
& PERF_EF_START
);
7655 head
= find_swevent_head(swhash
, event
);
7656 if (WARN_ON_ONCE(!head
))
7659 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7660 perf_event_update_userpage(event
);
7665 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7667 hlist_del_rcu(&event
->hlist_entry
);
7670 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7672 event
->hw
.state
= 0;
7675 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7677 event
->hw
.state
= PERF_HES_STOPPED
;
7680 /* Deref the hlist from the update side */
7681 static inline struct swevent_hlist
*
7682 swevent_hlist_deref(struct swevent_htable
*swhash
)
7684 return rcu_dereference_protected(swhash
->swevent_hlist
,
7685 lockdep_is_held(&swhash
->hlist_mutex
));
7688 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7690 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7695 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7696 kfree_rcu(hlist
, rcu_head
);
7699 static void swevent_hlist_put_cpu(int cpu
)
7701 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7703 mutex_lock(&swhash
->hlist_mutex
);
7705 if (!--swhash
->hlist_refcount
)
7706 swevent_hlist_release(swhash
);
7708 mutex_unlock(&swhash
->hlist_mutex
);
7711 static void swevent_hlist_put(void)
7715 for_each_possible_cpu(cpu
)
7716 swevent_hlist_put_cpu(cpu
);
7719 static int swevent_hlist_get_cpu(int cpu
)
7721 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7724 mutex_lock(&swhash
->hlist_mutex
);
7725 if (!swevent_hlist_deref(swhash
) &&
7726 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7727 struct swevent_hlist
*hlist
;
7729 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7734 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7736 swhash
->hlist_refcount
++;
7738 mutex_unlock(&swhash
->hlist_mutex
);
7743 static int swevent_hlist_get(void)
7745 int err
, cpu
, failed_cpu
;
7747 mutex_lock(&pmus_lock
);
7748 for_each_possible_cpu(cpu
) {
7749 err
= swevent_hlist_get_cpu(cpu
);
7755 mutex_unlock(&pmus_lock
);
7758 for_each_possible_cpu(cpu
) {
7759 if (cpu
== failed_cpu
)
7761 swevent_hlist_put_cpu(cpu
);
7763 mutex_unlock(&pmus_lock
);
7767 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7769 static void sw_perf_event_destroy(struct perf_event
*event
)
7771 u64 event_id
= event
->attr
.config
;
7773 WARN_ON(event
->parent
);
7775 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7776 swevent_hlist_put();
7779 static int perf_swevent_init(struct perf_event
*event
)
7781 u64 event_id
= event
->attr
.config
;
7783 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7787 * no branch sampling for software events
7789 if (has_branch_stack(event
))
7793 case PERF_COUNT_SW_CPU_CLOCK
:
7794 case PERF_COUNT_SW_TASK_CLOCK
:
7801 if (event_id
>= PERF_COUNT_SW_MAX
)
7804 if (!event
->parent
) {
7807 err
= swevent_hlist_get();
7811 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7812 event
->destroy
= sw_perf_event_destroy
;
7818 static struct pmu perf_swevent
= {
7819 .task_ctx_nr
= perf_sw_context
,
7821 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7823 .event_init
= perf_swevent_init
,
7824 .add
= perf_swevent_add
,
7825 .del
= perf_swevent_del
,
7826 .start
= perf_swevent_start
,
7827 .stop
= perf_swevent_stop
,
7828 .read
= perf_swevent_read
,
7831 #ifdef CONFIG_EVENT_TRACING
7833 static int perf_tp_filter_match(struct perf_event
*event
,
7834 struct perf_sample_data
*data
)
7836 void *record
= data
->raw
->frag
.data
;
7838 /* only top level events have filters set */
7840 event
= event
->parent
;
7842 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7847 static int perf_tp_event_match(struct perf_event
*event
,
7848 struct perf_sample_data
*data
,
7849 struct pt_regs
*regs
)
7851 if (event
->hw
.state
& PERF_HES_STOPPED
)
7854 * All tracepoints are from kernel-space.
7856 if (event
->attr
.exclude_kernel
)
7859 if (!perf_tp_filter_match(event
, data
))
7865 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7866 struct trace_event_call
*call
, u64 count
,
7867 struct pt_regs
*regs
, struct hlist_head
*head
,
7868 struct task_struct
*task
)
7870 if (bpf_prog_array_valid(call
)) {
7871 *(struct pt_regs
**)raw_data
= regs
;
7872 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
7873 perf_swevent_put_recursion_context(rctx
);
7877 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7880 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7882 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7883 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7884 struct task_struct
*task
)
7886 struct perf_sample_data data
;
7887 struct perf_event
*event
;
7889 struct perf_raw_record raw
= {
7896 perf_sample_data_init(&data
, 0, 0);
7899 perf_trace_buf_update(record
, event_type
);
7901 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7902 if (perf_tp_event_match(event
, &data
, regs
))
7903 perf_swevent_event(event
, count
, &data
, regs
);
7907 * If we got specified a target task, also iterate its context and
7908 * deliver this event there too.
7910 if (task
&& task
!= current
) {
7911 struct perf_event_context
*ctx
;
7912 struct trace_entry
*entry
= record
;
7915 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7919 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7920 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7922 if (event
->attr
.config
!= entry
->type
)
7924 if (perf_tp_event_match(event
, &data
, regs
))
7925 perf_swevent_event(event
, count
, &data
, regs
);
7931 perf_swevent_put_recursion_context(rctx
);
7933 EXPORT_SYMBOL_GPL(perf_tp_event
);
7935 static void tp_perf_event_destroy(struct perf_event
*event
)
7937 perf_trace_destroy(event
);
7940 static int perf_tp_event_init(struct perf_event
*event
)
7944 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7948 * no branch sampling for tracepoint events
7950 if (has_branch_stack(event
))
7953 err
= perf_trace_init(event
);
7957 event
->destroy
= tp_perf_event_destroy
;
7962 static struct pmu perf_tracepoint
= {
7963 .task_ctx_nr
= perf_sw_context
,
7965 .event_init
= perf_tp_event_init
,
7966 .add
= perf_trace_add
,
7967 .del
= perf_trace_del
,
7968 .start
= perf_swevent_start
,
7969 .stop
= perf_swevent_stop
,
7970 .read
= perf_swevent_read
,
7973 static inline void perf_tp_register(void)
7975 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7978 static void perf_event_free_filter(struct perf_event
*event
)
7980 ftrace_profile_free_filter(event
);
7983 #ifdef CONFIG_BPF_SYSCALL
7984 static void bpf_overflow_handler(struct perf_event
*event
,
7985 struct perf_sample_data
*data
,
7986 struct pt_regs
*regs
)
7988 struct bpf_perf_event_data_kern ctx
= {
7996 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
7999 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8002 __this_cpu_dec(bpf_prog_active
);
8007 event
->orig_overflow_handler(event
, data
, regs
);
8010 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8012 struct bpf_prog
*prog
;
8014 if (event
->overflow_handler_context
)
8015 /* hw breakpoint or kernel counter */
8021 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8023 return PTR_ERR(prog
);
8026 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8027 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8031 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8033 struct bpf_prog
*prog
= event
->prog
;
8038 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8043 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8047 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8052 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8054 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8055 struct bpf_prog
*prog
;
8058 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8059 return perf_event_set_bpf_handler(event
, prog_fd
);
8061 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8062 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8063 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8064 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8065 /* bpf programs can only be attached to u/kprobe or tracepoint */
8068 prog
= bpf_prog_get(prog_fd
);
8070 return PTR_ERR(prog
);
8072 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8073 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8074 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8075 /* valid fd, but invalid bpf program type */
8080 if (is_tracepoint
|| is_syscall_tp
) {
8081 int off
= trace_event_get_offsets(event
->tp_event
);
8083 if (prog
->aux
->max_ctx_offset
> off
) {
8089 ret
= perf_event_attach_bpf_prog(event
, prog
);
8095 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8097 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
) {
8098 perf_event_free_bpf_handler(event
);
8101 perf_event_detach_bpf_prog(event
);
8106 static inline void perf_tp_register(void)
8110 static void perf_event_free_filter(struct perf_event
*event
)
8114 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8119 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8122 #endif /* CONFIG_EVENT_TRACING */
8124 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8125 void perf_bp_event(struct perf_event
*bp
, void *data
)
8127 struct perf_sample_data sample
;
8128 struct pt_regs
*regs
= data
;
8130 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8132 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8133 perf_swevent_event(bp
, 1, &sample
, regs
);
8138 * Allocate a new address filter
8140 static struct perf_addr_filter
*
8141 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8143 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8144 struct perf_addr_filter
*filter
;
8146 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8150 INIT_LIST_HEAD(&filter
->entry
);
8151 list_add_tail(&filter
->entry
, filters
);
8156 static void free_filters_list(struct list_head
*filters
)
8158 struct perf_addr_filter
*filter
, *iter
;
8160 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8162 iput(filter
->inode
);
8163 list_del(&filter
->entry
);
8169 * Free existing address filters and optionally install new ones
8171 static void perf_addr_filters_splice(struct perf_event
*event
,
8172 struct list_head
*head
)
8174 unsigned long flags
;
8177 if (!has_addr_filter(event
))
8180 /* don't bother with children, they don't have their own filters */
8184 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8186 list_splice_init(&event
->addr_filters
.list
, &list
);
8188 list_splice(head
, &event
->addr_filters
.list
);
8190 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8192 free_filters_list(&list
);
8196 * Scan through mm's vmas and see if one of them matches the
8197 * @filter; if so, adjust filter's address range.
8198 * Called with mm::mmap_sem down for reading.
8200 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8201 struct mm_struct
*mm
)
8203 struct vm_area_struct
*vma
;
8205 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8206 struct file
*file
= vma
->vm_file
;
8207 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8208 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8213 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8216 return vma
->vm_start
;
8223 * Update event's address range filters based on the
8224 * task's existing mappings, if any.
8226 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8228 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8229 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8230 struct perf_addr_filter
*filter
;
8231 struct mm_struct
*mm
= NULL
;
8232 unsigned int count
= 0;
8233 unsigned long flags
;
8236 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8237 * will stop on the parent's child_mutex that our caller is also holding
8239 if (task
== TASK_TOMBSTONE
)
8242 if (!ifh
->nr_file_filters
)
8245 mm
= get_task_mm(event
->ctx
->task
);
8249 down_read(&mm
->mmap_sem
);
8251 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8252 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8253 event
->addr_filters_offs
[count
] = 0;
8256 * Adjust base offset if the filter is associated to a binary
8257 * that needs to be mapped:
8260 event
->addr_filters_offs
[count
] =
8261 perf_addr_filter_apply(filter
, mm
);
8266 event
->addr_filters_gen
++;
8267 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8269 up_read(&mm
->mmap_sem
);
8274 perf_event_stop(event
, 1);
8278 * Address range filtering: limiting the data to certain
8279 * instruction address ranges. Filters are ioctl()ed to us from
8280 * userspace as ascii strings.
8282 * Filter string format:
8285 * where ACTION is one of the
8286 * * "filter": limit the trace to this region
8287 * * "start": start tracing from this address
8288 * * "stop": stop tracing at this address/region;
8290 * * for kernel addresses: <start address>[/<size>]
8291 * * for object files: <start address>[/<size>]@</path/to/object/file>
8293 * if <size> is not specified, the range is treated as a single address.
8307 IF_STATE_ACTION
= 0,
8312 static const match_table_t if_tokens
= {
8313 { IF_ACT_FILTER
, "filter" },
8314 { IF_ACT_START
, "start" },
8315 { IF_ACT_STOP
, "stop" },
8316 { IF_SRC_FILE
, "%u/%u@%s" },
8317 { IF_SRC_KERNEL
, "%u/%u" },
8318 { IF_SRC_FILEADDR
, "%u@%s" },
8319 { IF_SRC_KERNELADDR
, "%u" },
8320 { IF_ACT_NONE
, NULL
},
8324 * Address filter string parser
8327 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8328 struct list_head
*filters
)
8330 struct perf_addr_filter
*filter
= NULL
;
8331 char *start
, *orig
, *filename
= NULL
;
8333 substring_t args
[MAX_OPT_ARGS
];
8334 int state
= IF_STATE_ACTION
, token
;
8335 unsigned int kernel
= 0;
8338 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8342 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8348 /* filter definition begins */
8349 if (state
== IF_STATE_ACTION
) {
8350 filter
= perf_addr_filter_new(event
, filters
);
8355 token
= match_token(start
, if_tokens
, args
);
8362 if (state
!= IF_STATE_ACTION
)
8365 state
= IF_STATE_SOURCE
;
8368 case IF_SRC_KERNELADDR
:
8372 case IF_SRC_FILEADDR
:
8374 if (state
!= IF_STATE_SOURCE
)
8377 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8381 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8385 if (filter
->range
) {
8387 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8392 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8393 int fpos
= filter
->range
? 2 : 1;
8395 filename
= match_strdup(&args
[fpos
]);
8402 state
= IF_STATE_END
;
8410 * Filter definition is fully parsed, validate and install it.
8411 * Make sure that it doesn't contradict itself or the event's
8414 if (state
== IF_STATE_END
) {
8416 if (kernel
&& event
->attr
.exclude_kernel
)
8424 * For now, we only support file-based filters
8425 * in per-task events; doing so for CPU-wide
8426 * events requires additional context switching
8427 * trickery, since same object code will be
8428 * mapped at different virtual addresses in
8429 * different processes.
8432 if (!event
->ctx
->task
)
8433 goto fail_free_name
;
8435 /* look up the path and grab its inode */
8436 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8438 goto fail_free_name
;
8440 filter
->inode
= igrab(d_inode(path
.dentry
));
8446 if (!filter
->inode
||
8447 !S_ISREG(filter
->inode
->i_mode
))
8448 /* free_filters_list() will iput() */
8451 event
->addr_filters
.nr_file_filters
++;
8454 /* ready to consume more filters */
8455 state
= IF_STATE_ACTION
;
8460 if (state
!= IF_STATE_ACTION
)
8470 free_filters_list(filters
);
8477 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8483 * Since this is called in perf_ioctl() path, we're already holding
8486 lockdep_assert_held(&event
->ctx
->mutex
);
8488 if (WARN_ON_ONCE(event
->parent
))
8491 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8493 goto fail_clear_files
;
8495 ret
= event
->pmu
->addr_filters_validate(&filters
);
8497 goto fail_free_filters
;
8499 /* remove existing filters, if any */
8500 perf_addr_filters_splice(event
, &filters
);
8502 /* install new filters */
8503 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8508 free_filters_list(&filters
);
8511 event
->addr_filters
.nr_file_filters
= 0;
8516 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8521 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8522 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8523 !has_addr_filter(event
))
8526 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8527 if (IS_ERR(filter_str
))
8528 return PTR_ERR(filter_str
);
8530 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8531 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8532 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8534 else if (has_addr_filter(event
))
8535 ret
= perf_event_set_addr_filter(event
, filter_str
);
8542 * hrtimer based swevent callback
8545 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8547 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8548 struct perf_sample_data data
;
8549 struct pt_regs
*regs
;
8550 struct perf_event
*event
;
8553 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8555 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8556 return HRTIMER_NORESTART
;
8558 event
->pmu
->read(event
);
8560 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8561 regs
= get_irq_regs();
8563 if (regs
&& !perf_exclude_event(event
, regs
)) {
8564 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8565 if (__perf_event_overflow(event
, 1, &data
, regs
))
8566 ret
= HRTIMER_NORESTART
;
8569 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8570 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8575 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8577 struct hw_perf_event
*hwc
= &event
->hw
;
8580 if (!is_sampling_event(event
))
8583 period
= local64_read(&hwc
->period_left
);
8588 local64_set(&hwc
->period_left
, 0);
8590 period
= max_t(u64
, 10000, hwc
->sample_period
);
8592 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8593 HRTIMER_MODE_REL_PINNED
);
8596 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8598 struct hw_perf_event
*hwc
= &event
->hw
;
8600 if (is_sampling_event(event
)) {
8601 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8602 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8604 hrtimer_cancel(&hwc
->hrtimer
);
8608 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8610 struct hw_perf_event
*hwc
= &event
->hw
;
8612 if (!is_sampling_event(event
))
8615 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8616 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8619 * Since hrtimers have a fixed rate, we can do a static freq->period
8620 * mapping and avoid the whole period adjust feedback stuff.
8622 if (event
->attr
.freq
) {
8623 long freq
= event
->attr
.sample_freq
;
8625 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8626 hwc
->sample_period
= event
->attr
.sample_period
;
8627 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8628 hwc
->last_period
= hwc
->sample_period
;
8629 event
->attr
.freq
= 0;
8634 * Software event: cpu wall time clock
8637 static void cpu_clock_event_update(struct perf_event
*event
)
8642 now
= local_clock();
8643 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8644 local64_add(now
- prev
, &event
->count
);
8647 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8649 local64_set(&event
->hw
.prev_count
, local_clock());
8650 perf_swevent_start_hrtimer(event
);
8653 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8655 perf_swevent_cancel_hrtimer(event
);
8656 cpu_clock_event_update(event
);
8659 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8661 if (flags
& PERF_EF_START
)
8662 cpu_clock_event_start(event
, flags
);
8663 perf_event_update_userpage(event
);
8668 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8670 cpu_clock_event_stop(event
, flags
);
8673 static void cpu_clock_event_read(struct perf_event
*event
)
8675 cpu_clock_event_update(event
);
8678 static int cpu_clock_event_init(struct perf_event
*event
)
8680 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8683 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8687 * no branch sampling for software events
8689 if (has_branch_stack(event
))
8692 perf_swevent_init_hrtimer(event
);
8697 static struct pmu perf_cpu_clock
= {
8698 .task_ctx_nr
= perf_sw_context
,
8700 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8702 .event_init
= cpu_clock_event_init
,
8703 .add
= cpu_clock_event_add
,
8704 .del
= cpu_clock_event_del
,
8705 .start
= cpu_clock_event_start
,
8706 .stop
= cpu_clock_event_stop
,
8707 .read
= cpu_clock_event_read
,
8711 * Software event: task time clock
8714 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8719 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8721 local64_add(delta
, &event
->count
);
8724 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8726 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8727 perf_swevent_start_hrtimer(event
);
8730 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8732 perf_swevent_cancel_hrtimer(event
);
8733 task_clock_event_update(event
, event
->ctx
->time
);
8736 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8738 if (flags
& PERF_EF_START
)
8739 task_clock_event_start(event
, flags
);
8740 perf_event_update_userpage(event
);
8745 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8747 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8750 static void task_clock_event_read(struct perf_event
*event
)
8752 u64 now
= perf_clock();
8753 u64 delta
= now
- event
->ctx
->timestamp
;
8754 u64 time
= event
->ctx
->time
+ delta
;
8756 task_clock_event_update(event
, time
);
8759 static int task_clock_event_init(struct perf_event
*event
)
8761 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8764 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8768 * no branch sampling for software events
8770 if (has_branch_stack(event
))
8773 perf_swevent_init_hrtimer(event
);
8778 static struct pmu perf_task_clock
= {
8779 .task_ctx_nr
= perf_sw_context
,
8781 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8783 .event_init
= task_clock_event_init
,
8784 .add
= task_clock_event_add
,
8785 .del
= task_clock_event_del
,
8786 .start
= task_clock_event_start
,
8787 .stop
= task_clock_event_stop
,
8788 .read
= task_clock_event_read
,
8791 static void perf_pmu_nop_void(struct pmu
*pmu
)
8795 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8799 static int perf_pmu_nop_int(struct pmu
*pmu
)
8804 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8806 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8808 __this_cpu_write(nop_txn_flags
, flags
);
8810 if (flags
& ~PERF_PMU_TXN_ADD
)
8813 perf_pmu_disable(pmu
);
8816 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8818 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8820 __this_cpu_write(nop_txn_flags
, 0);
8822 if (flags
& ~PERF_PMU_TXN_ADD
)
8825 perf_pmu_enable(pmu
);
8829 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8831 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8833 __this_cpu_write(nop_txn_flags
, 0);
8835 if (flags
& ~PERF_PMU_TXN_ADD
)
8838 perf_pmu_enable(pmu
);
8841 static int perf_event_idx_default(struct perf_event
*event
)
8847 * Ensures all contexts with the same task_ctx_nr have the same
8848 * pmu_cpu_context too.
8850 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8857 list_for_each_entry(pmu
, &pmus
, entry
) {
8858 if (pmu
->task_ctx_nr
== ctxn
)
8859 return pmu
->pmu_cpu_context
;
8865 static void free_pmu_context(struct pmu
*pmu
)
8868 * Static contexts such as perf_sw_context have a global lifetime
8869 * and may be shared between different PMUs. Avoid freeing them
8870 * when a single PMU is going away.
8872 if (pmu
->task_ctx_nr
> perf_invalid_context
)
8875 mutex_lock(&pmus_lock
);
8876 free_percpu(pmu
->pmu_cpu_context
);
8877 mutex_unlock(&pmus_lock
);
8881 * Let userspace know that this PMU supports address range filtering:
8883 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8884 struct device_attribute
*attr
,
8887 struct pmu
*pmu
= dev_get_drvdata(dev
);
8889 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8891 DEVICE_ATTR_RO(nr_addr_filters
);
8893 static struct idr pmu_idr
;
8896 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8898 struct pmu
*pmu
= dev_get_drvdata(dev
);
8900 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8902 static DEVICE_ATTR_RO(type
);
8905 perf_event_mux_interval_ms_show(struct device
*dev
,
8906 struct device_attribute
*attr
,
8909 struct pmu
*pmu
= dev_get_drvdata(dev
);
8911 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8914 static DEFINE_MUTEX(mux_interval_mutex
);
8917 perf_event_mux_interval_ms_store(struct device
*dev
,
8918 struct device_attribute
*attr
,
8919 const char *buf
, size_t count
)
8921 struct pmu
*pmu
= dev_get_drvdata(dev
);
8922 int timer
, cpu
, ret
;
8924 ret
= kstrtoint(buf
, 0, &timer
);
8931 /* same value, noting to do */
8932 if (timer
== pmu
->hrtimer_interval_ms
)
8935 mutex_lock(&mux_interval_mutex
);
8936 pmu
->hrtimer_interval_ms
= timer
;
8938 /* update all cpuctx for this PMU */
8940 for_each_online_cpu(cpu
) {
8941 struct perf_cpu_context
*cpuctx
;
8942 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8943 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8945 cpu_function_call(cpu
,
8946 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8949 mutex_unlock(&mux_interval_mutex
);
8953 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8955 static struct attribute
*pmu_dev_attrs
[] = {
8956 &dev_attr_type
.attr
,
8957 &dev_attr_perf_event_mux_interval_ms
.attr
,
8960 ATTRIBUTE_GROUPS(pmu_dev
);
8962 static int pmu_bus_running
;
8963 static struct bus_type pmu_bus
= {
8964 .name
= "event_source",
8965 .dev_groups
= pmu_dev_groups
,
8968 static void pmu_dev_release(struct device
*dev
)
8973 static int pmu_dev_alloc(struct pmu
*pmu
)
8977 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8981 pmu
->dev
->groups
= pmu
->attr_groups
;
8982 device_initialize(pmu
->dev
);
8983 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8987 dev_set_drvdata(pmu
->dev
, pmu
);
8988 pmu
->dev
->bus
= &pmu_bus
;
8989 pmu
->dev
->release
= pmu_dev_release
;
8990 ret
= device_add(pmu
->dev
);
8994 /* For PMUs with address filters, throw in an extra attribute: */
8995 if (pmu
->nr_addr_filters
)
8996 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9005 device_del(pmu
->dev
);
9008 put_device(pmu
->dev
);
9012 static struct lock_class_key cpuctx_mutex
;
9013 static struct lock_class_key cpuctx_lock
;
9015 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9019 mutex_lock(&pmus_lock
);
9021 pmu
->pmu_disable_count
= alloc_percpu(int);
9022 if (!pmu
->pmu_disable_count
)
9031 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9039 if (pmu_bus_running
) {
9040 ret
= pmu_dev_alloc(pmu
);
9046 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9047 static int hw_context_taken
= 0;
9050 * Other than systems with heterogeneous CPUs, it never makes
9051 * sense for two PMUs to share perf_hw_context. PMUs which are
9052 * uncore must use perf_invalid_context.
9054 if (WARN_ON_ONCE(hw_context_taken
&&
9055 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9056 pmu
->task_ctx_nr
= perf_invalid_context
;
9058 hw_context_taken
= 1;
9061 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9062 if (pmu
->pmu_cpu_context
)
9063 goto got_cpu_context
;
9066 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9067 if (!pmu
->pmu_cpu_context
)
9070 for_each_possible_cpu(cpu
) {
9071 struct perf_cpu_context
*cpuctx
;
9073 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9074 __perf_event_init_context(&cpuctx
->ctx
);
9075 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9076 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9077 cpuctx
->ctx
.pmu
= pmu
;
9078 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9080 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9084 if (!pmu
->start_txn
) {
9085 if (pmu
->pmu_enable
) {
9087 * If we have pmu_enable/pmu_disable calls, install
9088 * transaction stubs that use that to try and batch
9089 * hardware accesses.
9091 pmu
->start_txn
= perf_pmu_start_txn
;
9092 pmu
->commit_txn
= perf_pmu_commit_txn
;
9093 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9095 pmu
->start_txn
= perf_pmu_nop_txn
;
9096 pmu
->commit_txn
= perf_pmu_nop_int
;
9097 pmu
->cancel_txn
= perf_pmu_nop_void
;
9101 if (!pmu
->pmu_enable
) {
9102 pmu
->pmu_enable
= perf_pmu_nop_void
;
9103 pmu
->pmu_disable
= perf_pmu_nop_void
;
9106 if (!pmu
->event_idx
)
9107 pmu
->event_idx
= perf_event_idx_default
;
9109 list_add_rcu(&pmu
->entry
, &pmus
);
9110 atomic_set(&pmu
->exclusive_cnt
, 0);
9113 mutex_unlock(&pmus_lock
);
9118 device_del(pmu
->dev
);
9119 put_device(pmu
->dev
);
9122 if (pmu
->type
>= PERF_TYPE_MAX
)
9123 idr_remove(&pmu_idr
, pmu
->type
);
9126 free_percpu(pmu
->pmu_disable_count
);
9129 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9131 void perf_pmu_unregister(struct pmu
*pmu
)
9135 mutex_lock(&pmus_lock
);
9136 remove_device
= pmu_bus_running
;
9137 list_del_rcu(&pmu
->entry
);
9138 mutex_unlock(&pmus_lock
);
9141 * We dereference the pmu list under both SRCU and regular RCU, so
9142 * synchronize against both of those.
9144 synchronize_srcu(&pmus_srcu
);
9147 free_percpu(pmu
->pmu_disable_count
);
9148 if (pmu
->type
>= PERF_TYPE_MAX
)
9149 idr_remove(&pmu_idr
, pmu
->type
);
9150 if (remove_device
) {
9151 if (pmu
->nr_addr_filters
)
9152 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9153 device_del(pmu
->dev
);
9154 put_device(pmu
->dev
);
9156 free_pmu_context(pmu
);
9158 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9160 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9162 struct perf_event_context
*ctx
= NULL
;
9165 if (!try_module_get(pmu
->module
))
9168 if (event
->group_leader
!= event
) {
9170 * This ctx->mutex can nest when we're called through
9171 * inheritance. See the perf_event_ctx_lock_nested() comment.
9173 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9174 SINGLE_DEPTH_NESTING
);
9179 ret
= pmu
->event_init(event
);
9182 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9185 module_put(pmu
->module
);
9190 static struct pmu
*perf_init_event(struct perf_event
*event
)
9196 idx
= srcu_read_lock(&pmus_srcu
);
9198 /* Try parent's PMU first: */
9199 if (event
->parent
&& event
->parent
->pmu
) {
9200 pmu
= event
->parent
->pmu
;
9201 ret
= perf_try_init_event(pmu
, event
);
9207 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9210 ret
= perf_try_init_event(pmu
, event
);
9216 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9217 ret
= perf_try_init_event(pmu
, event
);
9221 if (ret
!= -ENOENT
) {
9226 pmu
= ERR_PTR(-ENOENT
);
9228 srcu_read_unlock(&pmus_srcu
, idx
);
9233 static void attach_sb_event(struct perf_event
*event
)
9235 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9237 raw_spin_lock(&pel
->lock
);
9238 list_add_rcu(&event
->sb_list
, &pel
->list
);
9239 raw_spin_unlock(&pel
->lock
);
9243 * We keep a list of all !task (and therefore per-cpu) events
9244 * that need to receive side-band records.
9246 * This avoids having to scan all the various PMU per-cpu contexts
9249 static void account_pmu_sb_event(struct perf_event
*event
)
9251 if (is_sb_event(event
))
9252 attach_sb_event(event
);
9255 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9260 if (is_cgroup_event(event
))
9261 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9264 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9265 static void account_freq_event_nohz(void)
9267 #ifdef CONFIG_NO_HZ_FULL
9268 /* Lock so we don't race with concurrent unaccount */
9269 spin_lock(&nr_freq_lock
);
9270 if (atomic_inc_return(&nr_freq_events
) == 1)
9271 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9272 spin_unlock(&nr_freq_lock
);
9276 static void account_freq_event(void)
9278 if (tick_nohz_full_enabled())
9279 account_freq_event_nohz();
9281 atomic_inc(&nr_freq_events
);
9285 static void account_event(struct perf_event
*event
)
9292 if (event
->attach_state
& PERF_ATTACH_TASK
)
9294 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9295 atomic_inc(&nr_mmap_events
);
9296 if (event
->attr
.comm
)
9297 atomic_inc(&nr_comm_events
);
9298 if (event
->attr
.namespaces
)
9299 atomic_inc(&nr_namespaces_events
);
9300 if (event
->attr
.task
)
9301 atomic_inc(&nr_task_events
);
9302 if (event
->attr
.freq
)
9303 account_freq_event();
9304 if (event
->attr
.context_switch
) {
9305 atomic_inc(&nr_switch_events
);
9308 if (has_branch_stack(event
))
9310 if (is_cgroup_event(event
))
9315 * We need the mutex here because static_branch_enable()
9316 * must complete *before* the perf_sched_count increment
9319 if (atomic_inc_not_zero(&perf_sched_count
))
9322 mutex_lock(&perf_sched_mutex
);
9323 if (!atomic_read(&perf_sched_count
)) {
9324 static_branch_enable(&perf_sched_events
);
9326 * Guarantee that all CPUs observe they key change and
9327 * call the perf scheduling hooks before proceeding to
9328 * install events that need them.
9330 synchronize_sched();
9333 * Now that we have waited for the sync_sched(), allow further
9334 * increments to by-pass the mutex.
9336 atomic_inc(&perf_sched_count
);
9337 mutex_unlock(&perf_sched_mutex
);
9341 account_event_cpu(event
, event
->cpu
);
9343 account_pmu_sb_event(event
);
9347 * Allocate and initialize a event structure
9349 static struct perf_event
*
9350 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9351 struct task_struct
*task
,
9352 struct perf_event
*group_leader
,
9353 struct perf_event
*parent_event
,
9354 perf_overflow_handler_t overflow_handler
,
9355 void *context
, int cgroup_fd
)
9358 struct perf_event
*event
;
9359 struct hw_perf_event
*hwc
;
9362 if ((unsigned)cpu
>= nr_cpu_ids
) {
9363 if (!task
|| cpu
!= -1)
9364 return ERR_PTR(-EINVAL
);
9367 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9369 return ERR_PTR(-ENOMEM
);
9372 * Single events are their own group leaders, with an
9373 * empty sibling list:
9376 group_leader
= event
;
9378 mutex_init(&event
->child_mutex
);
9379 INIT_LIST_HEAD(&event
->child_list
);
9381 INIT_LIST_HEAD(&event
->group_entry
);
9382 INIT_LIST_HEAD(&event
->event_entry
);
9383 INIT_LIST_HEAD(&event
->sibling_list
);
9384 INIT_LIST_HEAD(&event
->rb_entry
);
9385 INIT_LIST_HEAD(&event
->active_entry
);
9386 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9387 INIT_HLIST_NODE(&event
->hlist_entry
);
9390 init_waitqueue_head(&event
->waitq
);
9391 init_irq_work(&event
->pending
, perf_pending_event
);
9393 mutex_init(&event
->mmap_mutex
);
9394 raw_spin_lock_init(&event
->addr_filters
.lock
);
9396 atomic_long_set(&event
->refcount
, 1);
9398 event
->attr
= *attr
;
9399 event
->group_leader
= group_leader
;
9403 event
->parent
= parent_event
;
9405 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9406 event
->id
= atomic64_inc_return(&perf_event_id
);
9408 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9411 event
->attach_state
= PERF_ATTACH_TASK
;
9413 * XXX pmu::event_init needs to know what task to account to
9414 * and we cannot use the ctx information because we need the
9415 * pmu before we get a ctx.
9417 event
->hw
.target
= task
;
9420 event
->clock
= &local_clock
;
9422 event
->clock
= parent_event
->clock
;
9424 if (!overflow_handler
&& parent_event
) {
9425 overflow_handler
= parent_event
->overflow_handler
;
9426 context
= parent_event
->overflow_handler_context
;
9427 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9428 if (overflow_handler
== bpf_overflow_handler
) {
9429 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9432 err
= PTR_ERR(prog
);
9436 event
->orig_overflow_handler
=
9437 parent_event
->orig_overflow_handler
;
9442 if (overflow_handler
) {
9443 event
->overflow_handler
= overflow_handler
;
9444 event
->overflow_handler_context
= context
;
9445 } else if (is_write_backward(event
)){
9446 event
->overflow_handler
= perf_event_output_backward
;
9447 event
->overflow_handler_context
= NULL
;
9449 event
->overflow_handler
= perf_event_output_forward
;
9450 event
->overflow_handler_context
= NULL
;
9453 perf_event__state_init(event
);
9458 hwc
->sample_period
= attr
->sample_period
;
9459 if (attr
->freq
&& attr
->sample_freq
)
9460 hwc
->sample_period
= 1;
9461 hwc
->last_period
= hwc
->sample_period
;
9463 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9466 * We currently do not support PERF_SAMPLE_READ on inherited events.
9467 * See perf_output_read().
9469 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9472 if (!has_branch_stack(event
))
9473 event
->attr
.branch_sample_type
= 0;
9475 if (cgroup_fd
!= -1) {
9476 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9481 pmu
= perf_init_event(event
);
9487 err
= exclusive_event_init(event
);
9491 if (has_addr_filter(event
)) {
9492 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9493 sizeof(unsigned long),
9495 if (!event
->addr_filters_offs
) {
9500 /* force hw sync on the address filters */
9501 event
->addr_filters_gen
= 1;
9504 if (!event
->parent
) {
9505 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9506 err
= get_callchain_buffers(attr
->sample_max_stack
);
9508 goto err_addr_filters
;
9512 /* symmetric to unaccount_event() in _free_event() */
9513 account_event(event
);
9518 kfree(event
->addr_filters_offs
);
9521 exclusive_event_destroy(event
);
9525 event
->destroy(event
);
9526 module_put(pmu
->module
);
9528 if (is_cgroup_event(event
))
9529 perf_detach_cgroup(event
);
9531 put_pid_ns(event
->ns
);
9534 return ERR_PTR(err
);
9537 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9538 struct perf_event_attr
*attr
)
9543 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9547 * zero the full structure, so that a short copy will be nice.
9549 memset(attr
, 0, sizeof(*attr
));
9551 ret
= get_user(size
, &uattr
->size
);
9555 if (size
> PAGE_SIZE
) /* silly large */
9558 if (!size
) /* abi compat */
9559 size
= PERF_ATTR_SIZE_VER0
;
9561 if (size
< PERF_ATTR_SIZE_VER0
)
9565 * If we're handed a bigger struct than we know of,
9566 * ensure all the unknown bits are 0 - i.e. new
9567 * user-space does not rely on any kernel feature
9568 * extensions we dont know about yet.
9570 if (size
> sizeof(*attr
)) {
9571 unsigned char __user
*addr
;
9572 unsigned char __user
*end
;
9575 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9576 end
= (void __user
*)uattr
+ size
;
9578 for (; addr
< end
; addr
++) {
9579 ret
= get_user(val
, addr
);
9585 size
= sizeof(*attr
);
9588 ret
= copy_from_user(attr
, uattr
, size
);
9594 if (attr
->__reserved_1
)
9597 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9600 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9603 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9604 u64 mask
= attr
->branch_sample_type
;
9606 /* only using defined bits */
9607 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9610 /* at least one branch bit must be set */
9611 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9614 /* propagate priv level, when not set for branch */
9615 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9617 /* exclude_kernel checked on syscall entry */
9618 if (!attr
->exclude_kernel
)
9619 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9621 if (!attr
->exclude_user
)
9622 mask
|= PERF_SAMPLE_BRANCH_USER
;
9624 if (!attr
->exclude_hv
)
9625 mask
|= PERF_SAMPLE_BRANCH_HV
;
9627 * adjust user setting (for HW filter setup)
9629 attr
->branch_sample_type
= mask
;
9631 /* privileged levels capture (kernel, hv): check permissions */
9632 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9633 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9637 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9638 ret
= perf_reg_validate(attr
->sample_regs_user
);
9643 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9644 if (!arch_perf_have_user_stack_dump())
9648 * We have __u32 type for the size, but so far
9649 * we can only use __u16 as maximum due to the
9650 * __u16 sample size limit.
9652 if (attr
->sample_stack_user
>= USHRT_MAX
)
9654 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9658 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9659 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9664 put_user(sizeof(*attr
), &uattr
->size
);
9670 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9672 struct ring_buffer
*rb
= NULL
;
9678 /* don't allow circular references */
9679 if (event
== output_event
)
9683 * Don't allow cross-cpu buffers
9685 if (output_event
->cpu
!= event
->cpu
)
9689 * If its not a per-cpu rb, it must be the same task.
9691 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9695 * Mixing clocks in the same buffer is trouble you don't need.
9697 if (output_event
->clock
!= event
->clock
)
9701 * Either writing ring buffer from beginning or from end.
9702 * Mixing is not allowed.
9704 if (is_write_backward(output_event
) != is_write_backward(event
))
9708 * If both events generate aux data, they must be on the same PMU
9710 if (has_aux(event
) && has_aux(output_event
) &&
9711 event
->pmu
!= output_event
->pmu
)
9715 mutex_lock(&event
->mmap_mutex
);
9716 /* Can't redirect output if we've got an active mmap() */
9717 if (atomic_read(&event
->mmap_count
))
9721 /* get the rb we want to redirect to */
9722 rb
= ring_buffer_get(output_event
);
9727 ring_buffer_attach(event
, rb
);
9731 mutex_unlock(&event
->mmap_mutex
);
9737 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9743 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9746 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9748 bool nmi_safe
= false;
9751 case CLOCK_MONOTONIC
:
9752 event
->clock
= &ktime_get_mono_fast_ns
;
9756 case CLOCK_MONOTONIC_RAW
:
9757 event
->clock
= &ktime_get_raw_fast_ns
;
9761 case CLOCK_REALTIME
:
9762 event
->clock
= &ktime_get_real_ns
;
9765 case CLOCK_BOOTTIME
:
9766 event
->clock
= &ktime_get_boot_ns
;
9770 event
->clock
= &ktime_get_tai_ns
;
9777 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9784 * Variation on perf_event_ctx_lock_nested(), except we take two context
9787 static struct perf_event_context
*
9788 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9789 struct perf_event_context
*ctx
)
9791 struct perf_event_context
*gctx
;
9795 gctx
= READ_ONCE(group_leader
->ctx
);
9796 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9802 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9804 if (group_leader
->ctx
!= gctx
) {
9805 mutex_unlock(&ctx
->mutex
);
9806 mutex_unlock(&gctx
->mutex
);
9815 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9817 * @attr_uptr: event_id type attributes for monitoring/sampling
9820 * @group_fd: group leader event fd
9822 SYSCALL_DEFINE5(perf_event_open
,
9823 struct perf_event_attr __user
*, attr_uptr
,
9824 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9826 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9827 struct perf_event
*event
, *sibling
;
9828 struct perf_event_attr attr
;
9829 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9830 struct file
*event_file
= NULL
;
9831 struct fd group
= {NULL
, 0};
9832 struct task_struct
*task
= NULL
;
9837 int f_flags
= O_RDWR
;
9840 /* for future expandability... */
9841 if (flags
& ~PERF_FLAG_ALL
)
9844 err
= perf_copy_attr(attr_uptr
, &attr
);
9848 if (!attr
.exclude_kernel
) {
9849 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9853 if (attr
.namespaces
) {
9854 if (!capable(CAP_SYS_ADMIN
))
9859 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9862 if (attr
.sample_period
& (1ULL << 63))
9866 /* Only privileged users can get physical addresses */
9867 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
9868 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9871 if (!attr
.sample_max_stack
)
9872 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9875 * In cgroup mode, the pid argument is used to pass the fd
9876 * opened to the cgroup directory in cgroupfs. The cpu argument
9877 * designates the cpu on which to monitor threads from that
9880 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9883 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9884 f_flags
|= O_CLOEXEC
;
9886 event_fd
= get_unused_fd_flags(f_flags
);
9890 if (group_fd
!= -1) {
9891 err
= perf_fget_light(group_fd
, &group
);
9894 group_leader
= group
.file
->private_data
;
9895 if (flags
& PERF_FLAG_FD_OUTPUT
)
9896 output_event
= group_leader
;
9897 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9898 group_leader
= NULL
;
9901 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9902 task
= find_lively_task_by_vpid(pid
);
9904 err
= PTR_ERR(task
);
9909 if (task
&& group_leader
&&
9910 group_leader
->attr
.inherit
!= attr
.inherit
) {
9916 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9921 * Reuse ptrace permission checks for now.
9923 * We must hold cred_guard_mutex across this and any potential
9924 * perf_install_in_context() call for this new event to
9925 * serialize against exec() altering our credentials (and the
9926 * perf_event_exit_task() that could imply).
9929 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9933 if (flags
& PERF_FLAG_PID_CGROUP
)
9936 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9937 NULL
, NULL
, cgroup_fd
);
9938 if (IS_ERR(event
)) {
9939 err
= PTR_ERR(event
);
9943 if (is_sampling_event(event
)) {
9944 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9951 * Special case software events and allow them to be part of
9952 * any hardware group.
9956 if (attr
.use_clockid
) {
9957 err
= perf_event_set_clock(event
, attr
.clockid
);
9962 if (pmu
->task_ctx_nr
== perf_sw_context
)
9963 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9966 (is_software_event(event
) != is_software_event(group_leader
))) {
9967 if (is_software_event(event
)) {
9969 * If event and group_leader are not both a software
9970 * event, and event is, then group leader is not.
9972 * Allow the addition of software events to !software
9973 * groups, this is safe because software events never
9976 pmu
= group_leader
->pmu
;
9977 } else if (is_software_event(group_leader
) &&
9978 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9980 * In case the group is a pure software group, and we
9981 * try to add a hardware event, move the whole group to
9982 * the hardware context.
9989 * Get the target context (task or percpu):
9991 ctx
= find_get_context(pmu
, task
, event
);
9997 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10003 * Look up the group leader (we will attach this event to it):
10005 if (group_leader
) {
10009 * Do not allow a recursive hierarchy (this new sibling
10010 * becoming part of another group-sibling):
10012 if (group_leader
->group_leader
!= group_leader
)
10015 /* All events in a group should have the same clock */
10016 if (group_leader
->clock
!= event
->clock
)
10020 * Make sure we're both events for the same CPU;
10021 * grouping events for different CPUs is broken; since
10022 * you can never concurrently schedule them anyhow.
10024 if (group_leader
->cpu
!= event
->cpu
)
10028 * Make sure we're both on the same task, or both
10031 if (group_leader
->ctx
->task
!= ctx
->task
)
10035 * Do not allow to attach to a group in a different task
10036 * or CPU context. If we're moving SW events, we'll fix
10037 * this up later, so allow that.
10039 if (!move_group
&& group_leader
->ctx
!= ctx
)
10043 * Only a group leader can be exclusive or pinned
10045 if (attr
.exclusive
|| attr
.pinned
)
10049 if (output_event
) {
10050 err
= perf_event_set_output(event
, output_event
);
10055 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10057 if (IS_ERR(event_file
)) {
10058 err
= PTR_ERR(event_file
);
10064 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10066 if (gctx
->task
== TASK_TOMBSTONE
) {
10072 * Check if we raced against another sys_perf_event_open() call
10073 * moving the software group underneath us.
10075 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10077 * If someone moved the group out from under us, check
10078 * if this new event wound up on the same ctx, if so
10079 * its the regular !move_group case, otherwise fail.
10085 perf_event_ctx_unlock(group_leader
, gctx
);
10090 mutex_lock(&ctx
->mutex
);
10093 if (ctx
->task
== TASK_TOMBSTONE
) {
10098 if (!perf_event_validate_size(event
)) {
10105 * Check if the @cpu we're creating an event for is online.
10107 * We use the perf_cpu_context::ctx::mutex to serialize against
10108 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10110 struct perf_cpu_context
*cpuctx
=
10111 container_of(ctx
, struct perf_cpu_context
, ctx
);
10113 if (!cpuctx
->online
) {
10121 * Must be under the same ctx::mutex as perf_install_in_context(),
10122 * because we need to serialize with concurrent event creation.
10124 if (!exclusive_event_installable(event
, ctx
)) {
10125 /* exclusive and group stuff are assumed mutually exclusive */
10126 WARN_ON_ONCE(move_group
);
10132 WARN_ON_ONCE(ctx
->parent_ctx
);
10135 * This is the point on no return; we cannot fail hereafter. This is
10136 * where we start modifying current state.
10141 * See perf_event_ctx_lock() for comments on the details
10142 * of swizzling perf_event::ctx.
10144 perf_remove_from_context(group_leader
, 0);
10147 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10149 perf_remove_from_context(sibling
, 0);
10154 * Wait for everybody to stop referencing the events through
10155 * the old lists, before installing it on new lists.
10160 * Install the group siblings before the group leader.
10162 * Because a group leader will try and install the entire group
10163 * (through the sibling list, which is still in-tact), we can
10164 * end up with siblings installed in the wrong context.
10166 * By installing siblings first we NO-OP because they're not
10167 * reachable through the group lists.
10169 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10171 perf_event__state_init(sibling
);
10172 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10177 * Removing from the context ends up with disabled
10178 * event. What we want here is event in the initial
10179 * startup state, ready to be add into new context.
10181 perf_event__state_init(group_leader
);
10182 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10187 * Precalculate sample_data sizes; do while holding ctx::mutex such
10188 * that we're serialized against further additions and before
10189 * perf_install_in_context() which is the point the event is active and
10190 * can use these values.
10192 perf_event__header_size(event
);
10193 perf_event__id_header_size(event
);
10195 event
->owner
= current
;
10197 perf_install_in_context(ctx
, event
, event
->cpu
);
10198 perf_unpin_context(ctx
);
10201 perf_event_ctx_unlock(group_leader
, gctx
);
10202 mutex_unlock(&ctx
->mutex
);
10205 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10206 put_task_struct(task
);
10209 mutex_lock(¤t
->perf_event_mutex
);
10210 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10211 mutex_unlock(¤t
->perf_event_mutex
);
10214 * Drop the reference on the group_event after placing the
10215 * new event on the sibling_list. This ensures destruction
10216 * of the group leader will find the pointer to itself in
10217 * perf_group_detach().
10220 fd_install(event_fd
, event_file
);
10225 perf_event_ctx_unlock(group_leader
, gctx
);
10226 mutex_unlock(&ctx
->mutex
);
10230 perf_unpin_context(ctx
);
10234 * If event_file is set, the fput() above will have called ->release()
10235 * and that will take care of freeing the event.
10241 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10244 put_task_struct(task
);
10248 put_unused_fd(event_fd
);
10253 * perf_event_create_kernel_counter
10255 * @attr: attributes of the counter to create
10256 * @cpu: cpu in which the counter is bound
10257 * @task: task to profile (NULL for percpu)
10259 struct perf_event
*
10260 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10261 struct task_struct
*task
,
10262 perf_overflow_handler_t overflow_handler
,
10265 struct perf_event_context
*ctx
;
10266 struct perf_event
*event
;
10270 * Get the target context (task or percpu):
10273 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10274 overflow_handler
, context
, -1);
10275 if (IS_ERR(event
)) {
10276 err
= PTR_ERR(event
);
10280 /* Mark owner so we could distinguish it from user events. */
10281 event
->owner
= TASK_TOMBSTONE
;
10283 ctx
= find_get_context(event
->pmu
, task
, event
);
10285 err
= PTR_ERR(ctx
);
10289 WARN_ON_ONCE(ctx
->parent_ctx
);
10290 mutex_lock(&ctx
->mutex
);
10291 if (ctx
->task
== TASK_TOMBSTONE
) {
10298 * Check if the @cpu we're creating an event for is online.
10300 * We use the perf_cpu_context::ctx::mutex to serialize against
10301 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10303 struct perf_cpu_context
*cpuctx
=
10304 container_of(ctx
, struct perf_cpu_context
, ctx
);
10305 if (!cpuctx
->online
) {
10311 if (!exclusive_event_installable(event
, ctx
)) {
10316 perf_install_in_context(ctx
, event
, cpu
);
10317 perf_unpin_context(ctx
);
10318 mutex_unlock(&ctx
->mutex
);
10323 mutex_unlock(&ctx
->mutex
);
10324 perf_unpin_context(ctx
);
10329 return ERR_PTR(err
);
10331 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10333 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10335 struct perf_event_context
*src_ctx
;
10336 struct perf_event_context
*dst_ctx
;
10337 struct perf_event
*event
, *tmp
;
10340 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10341 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10344 * See perf_event_ctx_lock() for comments on the details
10345 * of swizzling perf_event::ctx.
10347 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10348 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10350 perf_remove_from_context(event
, 0);
10351 unaccount_event_cpu(event
, src_cpu
);
10353 list_add(&event
->migrate_entry
, &events
);
10357 * Wait for the events to quiesce before re-instating them.
10362 * Re-instate events in 2 passes.
10364 * Skip over group leaders and only install siblings on this first
10365 * pass, siblings will not get enabled without a leader, however a
10366 * leader will enable its siblings, even if those are still on the old
10369 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10370 if (event
->group_leader
== event
)
10373 list_del(&event
->migrate_entry
);
10374 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10375 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10376 account_event_cpu(event
, dst_cpu
);
10377 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10382 * Once all the siblings are setup properly, install the group leaders
10385 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10386 list_del(&event
->migrate_entry
);
10387 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10388 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10389 account_event_cpu(event
, dst_cpu
);
10390 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10393 mutex_unlock(&dst_ctx
->mutex
);
10394 mutex_unlock(&src_ctx
->mutex
);
10396 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10398 static void sync_child_event(struct perf_event
*child_event
,
10399 struct task_struct
*child
)
10401 struct perf_event
*parent_event
= child_event
->parent
;
10404 if (child_event
->attr
.inherit_stat
)
10405 perf_event_read_event(child_event
, child
);
10407 child_val
= perf_event_count(child_event
);
10410 * Add back the child's count to the parent's count:
10412 atomic64_add(child_val
, &parent_event
->child_count
);
10413 atomic64_add(child_event
->total_time_enabled
,
10414 &parent_event
->child_total_time_enabled
);
10415 atomic64_add(child_event
->total_time_running
,
10416 &parent_event
->child_total_time_running
);
10420 perf_event_exit_event(struct perf_event
*child_event
,
10421 struct perf_event_context
*child_ctx
,
10422 struct task_struct
*child
)
10424 struct perf_event
*parent_event
= child_event
->parent
;
10427 * Do not destroy the 'original' grouping; because of the context
10428 * switch optimization the original events could've ended up in a
10429 * random child task.
10431 * If we were to destroy the original group, all group related
10432 * operations would cease to function properly after this random
10435 * Do destroy all inherited groups, we don't care about those
10436 * and being thorough is better.
10438 raw_spin_lock_irq(&child_ctx
->lock
);
10439 WARN_ON_ONCE(child_ctx
->is_active
);
10442 perf_group_detach(child_event
);
10443 list_del_event(child_event
, child_ctx
);
10444 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
10445 raw_spin_unlock_irq(&child_ctx
->lock
);
10448 * Parent events are governed by their filedesc, retain them.
10450 if (!parent_event
) {
10451 perf_event_wakeup(child_event
);
10455 * Child events can be cleaned up.
10458 sync_child_event(child_event
, child
);
10461 * Remove this event from the parent's list
10463 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10464 mutex_lock(&parent_event
->child_mutex
);
10465 list_del_init(&child_event
->child_list
);
10466 mutex_unlock(&parent_event
->child_mutex
);
10469 * Kick perf_poll() for is_event_hup().
10471 perf_event_wakeup(parent_event
);
10472 free_event(child_event
);
10473 put_event(parent_event
);
10476 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10478 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10479 struct perf_event
*child_event
, *next
;
10481 WARN_ON_ONCE(child
!= current
);
10483 child_ctx
= perf_pin_task_context(child
, ctxn
);
10488 * In order to reduce the amount of tricky in ctx tear-down, we hold
10489 * ctx::mutex over the entire thing. This serializes against almost
10490 * everything that wants to access the ctx.
10492 * The exception is sys_perf_event_open() /
10493 * perf_event_create_kernel_count() which does find_get_context()
10494 * without ctx::mutex (it cannot because of the move_group double mutex
10495 * lock thing). See the comments in perf_install_in_context().
10497 mutex_lock(&child_ctx
->mutex
);
10500 * In a single ctx::lock section, de-schedule the events and detach the
10501 * context from the task such that we cannot ever get it scheduled back
10504 raw_spin_lock_irq(&child_ctx
->lock
);
10505 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10508 * Now that the context is inactive, destroy the task <-> ctx relation
10509 * and mark the context dead.
10511 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10512 put_ctx(child_ctx
); /* cannot be last */
10513 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10514 put_task_struct(current
); /* cannot be last */
10516 clone_ctx
= unclone_ctx(child_ctx
);
10517 raw_spin_unlock_irq(&child_ctx
->lock
);
10520 put_ctx(clone_ctx
);
10523 * Report the task dead after unscheduling the events so that we
10524 * won't get any samples after PERF_RECORD_EXIT. We can however still
10525 * get a few PERF_RECORD_READ events.
10527 perf_event_task(child
, child_ctx
, 0);
10529 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10530 perf_event_exit_event(child_event
, child_ctx
, child
);
10532 mutex_unlock(&child_ctx
->mutex
);
10534 put_ctx(child_ctx
);
10538 * When a child task exits, feed back event values to parent events.
10540 * Can be called with cred_guard_mutex held when called from
10541 * install_exec_creds().
10543 void perf_event_exit_task(struct task_struct
*child
)
10545 struct perf_event
*event
, *tmp
;
10548 mutex_lock(&child
->perf_event_mutex
);
10549 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10551 list_del_init(&event
->owner_entry
);
10554 * Ensure the list deletion is visible before we clear
10555 * the owner, closes a race against perf_release() where
10556 * we need to serialize on the owner->perf_event_mutex.
10558 smp_store_release(&event
->owner
, NULL
);
10560 mutex_unlock(&child
->perf_event_mutex
);
10562 for_each_task_context_nr(ctxn
)
10563 perf_event_exit_task_context(child
, ctxn
);
10566 * The perf_event_exit_task_context calls perf_event_task
10567 * with child's task_ctx, which generates EXIT events for
10568 * child contexts and sets child->perf_event_ctxp[] to NULL.
10569 * At this point we need to send EXIT events to cpu contexts.
10571 perf_event_task(child
, NULL
, 0);
10574 static void perf_free_event(struct perf_event
*event
,
10575 struct perf_event_context
*ctx
)
10577 struct perf_event
*parent
= event
->parent
;
10579 if (WARN_ON_ONCE(!parent
))
10582 mutex_lock(&parent
->child_mutex
);
10583 list_del_init(&event
->child_list
);
10584 mutex_unlock(&parent
->child_mutex
);
10588 raw_spin_lock_irq(&ctx
->lock
);
10589 perf_group_detach(event
);
10590 list_del_event(event
, ctx
);
10591 raw_spin_unlock_irq(&ctx
->lock
);
10596 * Free an unexposed, unused context as created by inheritance by
10597 * perf_event_init_task below, used by fork() in case of fail.
10599 * Not all locks are strictly required, but take them anyway to be nice and
10600 * help out with the lockdep assertions.
10602 void perf_event_free_task(struct task_struct
*task
)
10604 struct perf_event_context
*ctx
;
10605 struct perf_event
*event
, *tmp
;
10608 for_each_task_context_nr(ctxn
) {
10609 ctx
= task
->perf_event_ctxp
[ctxn
];
10613 mutex_lock(&ctx
->mutex
);
10614 raw_spin_lock_irq(&ctx
->lock
);
10616 * Destroy the task <-> ctx relation and mark the context dead.
10618 * This is important because even though the task hasn't been
10619 * exposed yet the context has been (through child_list).
10621 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10622 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10623 put_task_struct(task
); /* cannot be last */
10624 raw_spin_unlock_irq(&ctx
->lock
);
10626 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10627 perf_free_event(event
, ctx
);
10629 mutex_unlock(&ctx
->mutex
);
10634 void perf_event_delayed_put(struct task_struct
*task
)
10638 for_each_task_context_nr(ctxn
)
10639 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10642 struct file
*perf_event_get(unsigned int fd
)
10646 file
= fget_raw(fd
);
10648 return ERR_PTR(-EBADF
);
10650 if (file
->f_op
!= &perf_fops
) {
10652 return ERR_PTR(-EBADF
);
10658 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10661 return ERR_PTR(-EINVAL
);
10663 return &event
->attr
;
10667 * Inherit a event from parent task to child task.
10670 * - valid pointer on success
10671 * - NULL for orphaned events
10672 * - IS_ERR() on error
10674 static struct perf_event
*
10675 inherit_event(struct perf_event
*parent_event
,
10676 struct task_struct
*parent
,
10677 struct perf_event_context
*parent_ctx
,
10678 struct task_struct
*child
,
10679 struct perf_event
*group_leader
,
10680 struct perf_event_context
*child_ctx
)
10682 enum perf_event_state parent_state
= parent_event
->state
;
10683 struct perf_event
*child_event
;
10684 unsigned long flags
;
10687 * Instead of creating recursive hierarchies of events,
10688 * we link inherited events back to the original parent,
10689 * which has a filp for sure, which we use as the reference
10692 if (parent_event
->parent
)
10693 parent_event
= parent_event
->parent
;
10695 child_event
= perf_event_alloc(&parent_event
->attr
,
10698 group_leader
, parent_event
,
10700 if (IS_ERR(child_event
))
10701 return child_event
;
10704 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10705 * must be under the same lock in order to serialize against
10706 * perf_event_release_kernel(), such that either we must observe
10707 * is_orphaned_event() or they will observe us on the child_list.
10709 mutex_lock(&parent_event
->child_mutex
);
10710 if (is_orphaned_event(parent_event
) ||
10711 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10712 mutex_unlock(&parent_event
->child_mutex
);
10713 free_event(child_event
);
10717 get_ctx(child_ctx
);
10720 * Make the child state follow the state of the parent event,
10721 * not its attr.disabled bit. We hold the parent's mutex,
10722 * so we won't race with perf_event_{en, dis}able_family.
10724 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10725 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10727 child_event
->state
= PERF_EVENT_STATE_OFF
;
10729 if (parent_event
->attr
.freq
) {
10730 u64 sample_period
= parent_event
->hw
.sample_period
;
10731 struct hw_perf_event
*hwc
= &child_event
->hw
;
10733 hwc
->sample_period
= sample_period
;
10734 hwc
->last_period
= sample_period
;
10736 local64_set(&hwc
->period_left
, sample_period
);
10739 child_event
->ctx
= child_ctx
;
10740 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10741 child_event
->overflow_handler_context
10742 = parent_event
->overflow_handler_context
;
10745 * Precalculate sample_data sizes
10747 perf_event__header_size(child_event
);
10748 perf_event__id_header_size(child_event
);
10751 * Link it up in the child's context:
10753 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10754 add_event_to_ctx(child_event
, child_ctx
);
10755 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10758 * Link this into the parent event's child list
10760 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10761 mutex_unlock(&parent_event
->child_mutex
);
10763 return child_event
;
10767 * Inherits an event group.
10769 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10770 * This matches with perf_event_release_kernel() removing all child events.
10776 static int inherit_group(struct perf_event
*parent_event
,
10777 struct task_struct
*parent
,
10778 struct perf_event_context
*parent_ctx
,
10779 struct task_struct
*child
,
10780 struct perf_event_context
*child_ctx
)
10782 struct perf_event
*leader
;
10783 struct perf_event
*sub
;
10784 struct perf_event
*child_ctr
;
10786 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10787 child
, NULL
, child_ctx
);
10788 if (IS_ERR(leader
))
10789 return PTR_ERR(leader
);
10791 * @leader can be NULL here because of is_orphaned_event(). In this
10792 * case inherit_event() will create individual events, similar to what
10793 * perf_group_detach() would do anyway.
10795 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10796 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10797 child
, leader
, child_ctx
);
10798 if (IS_ERR(child_ctr
))
10799 return PTR_ERR(child_ctr
);
10805 * Creates the child task context and tries to inherit the event-group.
10807 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10808 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10809 * consistent with perf_event_release_kernel() removing all child events.
10816 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10817 struct perf_event_context
*parent_ctx
,
10818 struct task_struct
*child
, int ctxn
,
10819 int *inherited_all
)
10822 struct perf_event_context
*child_ctx
;
10824 if (!event
->attr
.inherit
) {
10825 *inherited_all
= 0;
10829 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10832 * This is executed from the parent task context, so
10833 * inherit events that have been marked for cloning.
10834 * First allocate and initialize a context for the
10837 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10841 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10844 ret
= inherit_group(event
, parent
, parent_ctx
,
10848 *inherited_all
= 0;
10854 * Initialize the perf_event context in task_struct
10856 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10858 struct perf_event_context
*child_ctx
, *parent_ctx
;
10859 struct perf_event_context
*cloned_ctx
;
10860 struct perf_event
*event
;
10861 struct task_struct
*parent
= current
;
10862 int inherited_all
= 1;
10863 unsigned long flags
;
10866 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10870 * If the parent's context is a clone, pin it so it won't get
10871 * swapped under us.
10873 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10878 * No need to check if parent_ctx != NULL here; since we saw
10879 * it non-NULL earlier, the only reason for it to become NULL
10880 * is if we exit, and since we're currently in the middle of
10881 * a fork we can't be exiting at the same time.
10885 * Lock the parent list. No need to lock the child - not PID
10886 * hashed yet and not running, so nobody can access it.
10888 mutex_lock(&parent_ctx
->mutex
);
10891 * We dont have to disable NMIs - we are only looking at
10892 * the list, not manipulating it:
10894 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10895 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10896 child
, ctxn
, &inherited_all
);
10902 * We can't hold ctx->lock when iterating the ->flexible_group list due
10903 * to allocations, but we need to prevent rotation because
10904 * rotate_ctx() will change the list from interrupt context.
10906 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10907 parent_ctx
->rotate_disable
= 1;
10908 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10910 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10911 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10912 child
, ctxn
, &inherited_all
);
10917 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10918 parent_ctx
->rotate_disable
= 0;
10920 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10922 if (child_ctx
&& inherited_all
) {
10924 * Mark the child context as a clone of the parent
10925 * context, or of whatever the parent is a clone of.
10927 * Note that if the parent is a clone, the holding of
10928 * parent_ctx->lock avoids it from being uncloned.
10930 cloned_ctx
= parent_ctx
->parent_ctx
;
10932 child_ctx
->parent_ctx
= cloned_ctx
;
10933 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10935 child_ctx
->parent_ctx
= parent_ctx
;
10936 child_ctx
->parent_gen
= parent_ctx
->generation
;
10938 get_ctx(child_ctx
->parent_ctx
);
10941 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10943 mutex_unlock(&parent_ctx
->mutex
);
10945 perf_unpin_context(parent_ctx
);
10946 put_ctx(parent_ctx
);
10952 * Initialize the perf_event context in task_struct
10954 int perf_event_init_task(struct task_struct
*child
)
10958 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10959 mutex_init(&child
->perf_event_mutex
);
10960 INIT_LIST_HEAD(&child
->perf_event_list
);
10962 for_each_task_context_nr(ctxn
) {
10963 ret
= perf_event_init_context(child
, ctxn
);
10965 perf_event_free_task(child
);
10973 static void __init
perf_event_init_all_cpus(void)
10975 struct swevent_htable
*swhash
;
10978 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
10980 for_each_possible_cpu(cpu
) {
10981 swhash
= &per_cpu(swevent_htable
, cpu
);
10982 mutex_init(&swhash
->hlist_mutex
);
10983 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10985 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10986 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10988 #ifdef CONFIG_CGROUP_PERF
10989 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
10991 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10995 void perf_swevent_init_cpu(unsigned int cpu
)
10997 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10999 mutex_lock(&swhash
->hlist_mutex
);
11000 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11001 struct swevent_hlist
*hlist
;
11003 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11005 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11007 mutex_unlock(&swhash
->hlist_mutex
);
11010 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11011 static void __perf_event_exit_context(void *__info
)
11013 struct perf_event_context
*ctx
= __info
;
11014 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11015 struct perf_event
*event
;
11017 raw_spin_lock(&ctx
->lock
);
11018 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
11019 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11020 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11021 raw_spin_unlock(&ctx
->lock
);
11024 static void perf_event_exit_cpu_context(int cpu
)
11026 struct perf_cpu_context
*cpuctx
;
11027 struct perf_event_context
*ctx
;
11030 mutex_lock(&pmus_lock
);
11031 list_for_each_entry(pmu
, &pmus
, entry
) {
11032 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11033 ctx
= &cpuctx
->ctx
;
11035 mutex_lock(&ctx
->mutex
);
11036 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11037 cpuctx
->online
= 0;
11038 mutex_unlock(&ctx
->mutex
);
11040 cpumask_clear_cpu(cpu
, perf_online_mask
);
11041 mutex_unlock(&pmus_lock
);
11045 static void perf_event_exit_cpu_context(int cpu
) { }
11049 int perf_event_init_cpu(unsigned int cpu
)
11051 struct perf_cpu_context
*cpuctx
;
11052 struct perf_event_context
*ctx
;
11055 perf_swevent_init_cpu(cpu
);
11057 mutex_lock(&pmus_lock
);
11058 cpumask_set_cpu(cpu
, perf_online_mask
);
11059 list_for_each_entry(pmu
, &pmus
, entry
) {
11060 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11061 ctx
= &cpuctx
->ctx
;
11063 mutex_lock(&ctx
->mutex
);
11064 cpuctx
->online
= 1;
11065 mutex_unlock(&ctx
->mutex
);
11067 mutex_unlock(&pmus_lock
);
11072 int perf_event_exit_cpu(unsigned int cpu
)
11074 perf_event_exit_cpu_context(cpu
);
11079 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11083 for_each_online_cpu(cpu
)
11084 perf_event_exit_cpu(cpu
);
11090 * Run the perf reboot notifier at the very last possible moment so that
11091 * the generic watchdog code runs as long as possible.
11093 static struct notifier_block perf_reboot_notifier
= {
11094 .notifier_call
= perf_reboot
,
11095 .priority
= INT_MIN
,
11098 void __init
perf_event_init(void)
11102 idr_init(&pmu_idr
);
11104 perf_event_init_all_cpus();
11105 init_srcu_struct(&pmus_srcu
);
11106 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11107 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11108 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11109 perf_tp_register();
11110 perf_event_init_cpu(smp_processor_id());
11111 register_reboot_notifier(&perf_reboot_notifier
);
11113 ret
= init_hw_breakpoint();
11114 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11117 * Build time assertion that we keep the data_head at the intended
11118 * location. IOW, validation we got the __reserved[] size right.
11120 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11124 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11127 struct perf_pmu_events_attr
*pmu_attr
=
11128 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11130 if (pmu_attr
->event_str
)
11131 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11135 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11137 static int __init
perf_event_sysfs_init(void)
11142 mutex_lock(&pmus_lock
);
11144 ret
= bus_register(&pmu_bus
);
11148 list_for_each_entry(pmu
, &pmus
, entry
) {
11149 if (!pmu
->name
|| pmu
->type
< 0)
11152 ret
= pmu_dev_alloc(pmu
);
11153 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11155 pmu_bus_running
= 1;
11159 mutex_unlock(&pmus_lock
);
11163 device_initcall(perf_event_sysfs_init
);
11165 #ifdef CONFIG_CGROUP_PERF
11166 static struct cgroup_subsys_state
*
11167 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11169 struct perf_cgroup
*jc
;
11171 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11173 return ERR_PTR(-ENOMEM
);
11175 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11178 return ERR_PTR(-ENOMEM
);
11184 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11186 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11188 free_percpu(jc
->info
);
11192 static int __perf_cgroup_move(void *info
)
11194 struct task_struct
*task
= info
;
11196 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11201 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11203 struct task_struct
*task
;
11204 struct cgroup_subsys_state
*css
;
11206 cgroup_taskset_for_each(task
, css
, tset
)
11207 task_function_call(task
, __perf_cgroup_move
, task
);
11210 struct cgroup_subsys perf_event_cgrp_subsys
= {
11211 .css_alloc
= perf_cgroup_css_alloc
,
11212 .css_free
= perf_cgroup_css_free
,
11213 .attach
= perf_cgroup_attach
,
11215 * Implicitly enable on dfl hierarchy so that perf events can
11216 * always be filtered by cgroup2 path as long as perf_event
11217 * controller is not mounted on a legacy hierarchy.
11219 .implicit_on_dfl
= true,
11222 #endif /* CONFIG_CGROUP_PERF */