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
400 * 3 - disallow all unpriv perf event use
402 #ifdef CONFIG_SECURITY_PERF_EVENTS_RESTRICT
403 int sysctl_perf_event_paranoid __read_mostly
= 3;
405 int sysctl_perf_event_paranoid __read_mostly
= 1;
408 /* Minimum for 512 kiB + 1 user control page */
409 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
412 * max perf event sample rate
414 #define DEFAULT_MAX_SAMPLE_RATE 100000
415 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
416 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
418 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
420 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
421 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
423 static int perf_sample_allowed_ns __read_mostly
=
424 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
426 static void update_perf_cpu_limits(void)
428 u64 tmp
= perf_sample_period_ns
;
430 tmp
*= sysctl_perf_cpu_time_max_percent
;
431 tmp
= div_u64(tmp
, 100);
435 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
438 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
440 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
441 void __user
*buffer
, size_t *lenp
,
444 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
450 * If throttling is disabled don't allow the write:
452 if (sysctl_perf_cpu_time_max_percent
== 100 ||
453 sysctl_perf_cpu_time_max_percent
== 0)
456 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
457 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
458 update_perf_cpu_limits();
463 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
465 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
466 void __user
*buffer
, size_t *lenp
,
469 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
474 if (sysctl_perf_cpu_time_max_percent
== 100 ||
475 sysctl_perf_cpu_time_max_percent
== 0) {
477 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
478 WRITE_ONCE(perf_sample_allowed_ns
, 0);
480 update_perf_cpu_limits();
487 * perf samples are done in some very critical code paths (NMIs).
488 * If they take too much CPU time, the system can lock up and not
489 * get any real work done. This will drop the sample rate when
490 * we detect that events are taking too long.
492 #define NR_ACCUMULATED_SAMPLES 128
493 static DEFINE_PER_CPU(u64
, running_sample_length
);
495 static u64 __report_avg
;
496 static u64 __report_allowed
;
498 static void perf_duration_warn(struct irq_work
*w
)
500 printk_ratelimited(KERN_INFO
501 "perf: interrupt took too long (%lld > %lld), lowering "
502 "kernel.perf_event_max_sample_rate to %d\n",
503 __report_avg
, __report_allowed
,
504 sysctl_perf_event_sample_rate
);
507 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
509 void perf_sample_event_took(u64 sample_len_ns
)
511 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
519 /* Decay the counter by 1 average sample. */
520 running_len
= __this_cpu_read(running_sample_length
);
521 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
522 running_len
+= sample_len_ns
;
523 __this_cpu_write(running_sample_length
, running_len
);
526 * Note: this will be biased artifically low until we have
527 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
528 * from having to maintain a count.
530 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
531 if (avg_len
<= max_len
)
534 __report_avg
= avg_len
;
535 __report_allowed
= max_len
;
538 * Compute a throttle threshold 25% below the current duration.
540 avg_len
+= avg_len
/ 4;
541 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
547 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
548 WRITE_ONCE(max_samples_per_tick
, max
);
550 sysctl_perf_event_sample_rate
= max
* HZ
;
551 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
553 if (!irq_work_queue(&perf_duration_work
)) {
554 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
555 "kernel.perf_event_max_sample_rate to %d\n",
556 __report_avg
, __report_allowed
,
557 sysctl_perf_event_sample_rate
);
561 static atomic64_t perf_event_id
;
563 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
564 enum event_type_t event_type
);
566 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
567 enum event_type_t event_type
,
568 struct task_struct
*task
);
570 static void update_context_time(struct perf_event_context
*ctx
);
571 static u64
perf_event_time(struct perf_event
*event
);
573 void __weak
perf_event_print_debug(void) { }
575 extern __weak
const char *perf_pmu_name(void)
580 static inline u64
perf_clock(void)
582 return local_clock();
585 static inline u64
perf_event_clock(struct perf_event
*event
)
587 return event
->clock();
591 * State based event timekeeping...
593 * The basic idea is to use event->state to determine which (if any) time
594 * fields to increment with the current delta. This means we only need to
595 * update timestamps when we change state or when they are explicitly requested
598 * Event groups make things a little more complicated, but not terribly so. The
599 * rules for a group are that if the group leader is OFF the entire group is
600 * OFF, irrespecive of what the group member states are. This results in
601 * __perf_effective_state().
603 * A futher ramification is that when a group leader flips between OFF and
604 * !OFF, we need to update all group member times.
607 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
608 * need to make sure the relevant context time is updated before we try and
609 * update our timestamps.
612 static __always_inline
enum perf_event_state
613 __perf_effective_state(struct perf_event
*event
)
615 struct perf_event
*leader
= event
->group_leader
;
617 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
618 return leader
->state
;
623 static __always_inline
void
624 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
626 enum perf_event_state state
= __perf_effective_state(event
);
627 u64 delta
= now
- event
->tstamp
;
629 *enabled
= event
->total_time_enabled
;
630 if (state
>= PERF_EVENT_STATE_INACTIVE
)
633 *running
= event
->total_time_running
;
634 if (state
>= PERF_EVENT_STATE_ACTIVE
)
638 static void perf_event_update_time(struct perf_event
*event
)
640 u64 now
= perf_event_time(event
);
642 __perf_update_times(event
, now
, &event
->total_time_enabled
,
643 &event
->total_time_running
);
647 static void perf_event_update_sibling_time(struct perf_event
*leader
)
649 struct perf_event
*sibling
;
651 list_for_each_entry(sibling
, &leader
->sibling_list
, group_entry
)
652 perf_event_update_time(sibling
);
656 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
658 if (event
->state
== state
)
661 perf_event_update_time(event
);
663 * If a group leader gets enabled/disabled all its siblings
666 if ((event
->state
< 0) ^ (state
< 0))
667 perf_event_update_sibling_time(event
);
669 WRITE_ONCE(event
->state
, state
);
672 #ifdef CONFIG_CGROUP_PERF
675 perf_cgroup_match(struct perf_event
*event
)
677 struct perf_event_context
*ctx
= event
->ctx
;
678 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
680 /* @event doesn't care about cgroup */
684 /* wants specific cgroup scope but @cpuctx isn't associated with any */
689 * Cgroup scoping is recursive. An event enabled for a cgroup is
690 * also enabled for all its descendant cgroups. If @cpuctx's
691 * cgroup is a descendant of @event's (the test covers identity
692 * case), it's a match.
694 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
695 event
->cgrp
->css
.cgroup
);
698 static inline void perf_detach_cgroup(struct perf_event
*event
)
700 css_put(&event
->cgrp
->css
);
704 static inline int is_cgroup_event(struct perf_event
*event
)
706 return event
->cgrp
!= NULL
;
709 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
711 struct perf_cgroup_info
*t
;
713 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
717 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
719 struct perf_cgroup_info
*info
;
724 info
= this_cpu_ptr(cgrp
->info
);
726 info
->time
+= now
- info
->timestamp
;
727 info
->timestamp
= now
;
730 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
732 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
733 struct cgroup_subsys_state
*css
;
736 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
737 cgrp
= container_of(css
, struct perf_cgroup
, css
);
738 __update_cgrp_time(cgrp
);
743 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
745 struct perf_cgroup
*cgrp
;
748 * ensure we access cgroup data only when needed and
749 * when we know the cgroup is pinned (css_get)
751 if (!is_cgroup_event(event
))
754 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
756 * Do not update time when cgroup is not active
758 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
759 __update_cgrp_time(event
->cgrp
);
763 perf_cgroup_set_timestamp(struct task_struct
*task
,
764 struct perf_event_context
*ctx
)
766 struct perf_cgroup
*cgrp
;
767 struct perf_cgroup_info
*info
;
768 struct cgroup_subsys_state
*css
;
771 * ctx->lock held by caller
772 * ensure we do not access cgroup data
773 * unless we have the cgroup pinned (css_get)
775 if (!task
|| !ctx
->nr_cgroups
)
778 cgrp
= perf_cgroup_from_task(task
, ctx
);
780 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
781 cgrp
= container_of(css
, struct perf_cgroup
, css
);
782 info
= this_cpu_ptr(cgrp
->info
);
783 info
->timestamp
= ctx
->timestamp
;
787 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
789 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
790 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
793 * reschedule events based on the cgroup constraint of task.
795 * mode SWOUT : schedule out everything
796 * mode SWIN : schedule in based on cgroup for next
798 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
800 struct perf_cpu_context
*cpuctx
;
801 struct list_head
*list
;
805 * Disable interrupts and preemption to avoid this CPU's
806 * cgrp_cpuctx_entry to change under us.
808 local_irq_save(flags
);
810 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
811 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
812 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
814 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
815 perf_pmu_disable(cpuctx
->ctx
.pmu
);
817 if (mode
& PERF_CGROUP_SWOUT
) {
818 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
820 * must not be done before ctxswout due
821 * to event_filter_match() in event_sched_out()
826 if (mode
& PERF_CGROUP_SWIN
) {
827 WARN_ON_ONCE(cpuctx
->cgrp
);
829 * set cgrp before ctxsw in to allow
830 * event_filter_match() to not have to pass
832 * we pass the cpuctx->ctx to perf_cgroup_from_task()
833 * because cgorup events are only per-cpu
835 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
837 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
839 perf_pmu_enable(cpuctx
->ctx
.pmu
);
840 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
843 local_irq_restore(flags
);
846 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
847 struct task_struct
*next
)
849 struct perf_cgroup
*cgrp1
;
850 struct perf_cgroup
*cgrp2
= NULL
;
854 * we come here when we know perf_cgroup_events > 0
855 * we do not need to pass the ctx here because we know
856 * we are holding the rcu lock
858 cgrp1
= perf_cgroup_from_task(task
, NULL
);
859 cgrp2
= perf_cgroup_from_task(next
, NULL
);
862 * only schedule out current cgroup events if we know
863 * that we are switching to a different cgroup. Otherwise,
864 * do no touch the cgroup events.
867 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
872 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
873 struct task_struct
*task
)
875 struct perf_cgroup
*cgrp1
;
876 struct perf_cgroup
*cgrp2
= NULL
;
880 * we come here when we know perf_cgroup_events > 0
881 * we do not need to pass the ctx here because we know
882 * we are holding the rcu lock
884 cgrp1
= perf_cgroup_from_task(task
, NULL
);
885 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
888 * only need to schedule in cgroup events if we are changing
889 * cgroup during ctxsw. Cgroup events were not scheduled
890 * out of ctxsw out if that was not the case.
893 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
898 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
899 struct perf_event_attr
*attr
,
900 struct perf_event
*group_leader
)
902 struct perf_cgroup
*cgrp
;
903 struct cgroup_subsys_state
*css
;
904 struct fd f
= fdget(fd
);
910 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
911 &perf_event_cgrp_subsys
);
917 cgrp
= container_of(css
, struct perf_cgroup
, css
);
921 * all events in a group must monitor
922 * the same cgroup because a task belongs
923 * to only one perf cgroup at a time
925 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
926 perf_detach_cgroup(event
);
935 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
937 struct perf_cgroup_info
*t
;
938 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
939 event
->shadow_ctx_time
= now
- t
->timestamp
;
943 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
944 * cleared when last cgroup event is removed.
947 list_update_cgroup_event(struct perf_event
*event
,
948 struct perf_event_context
*ctx
, bool add
)
950 struct perf_cpu_context
*cpuctx
;
951 struct list_head
*cpuctx_entry
;
953 if (!is_cgroup_event(event
))
957 * Because cgroup events are always per-cpu events,
958 * this will always be called from the right CPU.
960 cpuctx
= __get_cpu_context(ctx
);
963 * Since setting cpuctx->cgrp is conditional on the current @cgrp
964 * matching the event's cgroup, we must do this for every new event,
965 * because if the first would mismatch, the second would not try again
966 * and we would leave cpuctx->cgrp unset.
968 if (add
&& !cpuctx
->cgrp
) {
969 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
971 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
975 if (add
&& ctx
->nr_cgroups
++)
977 else if (!add
&& --ctx
->nr_cgroups
)
980 /* no cgroup running */
984 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
986 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
988 list_del(cpuctx_entry
);
991 #else /* !CONFIG_CGROUP_PERF */
994 perf_cgroup_match(struct perf_event
*event
)
999 static inline void perf_detach_cgroup(struct perf_event
*event
)
1002 static inline int is_cgroup_event(struct perf_event
*event
)
1007 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1011 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1015 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1016 struct task_struct
*next
)
1020 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1021 struct task_struct
*task
)
1025 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1026 struct perf_event_attr
*attr
,
1027 struct perf_event
*group_leader
)
1033 perf_cgroup_set_timestamp(struct task_struct
*task
,
1034 struct perf_event_context
*ctx
)
1039 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1044 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1048 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1054 list_update_cgroup_event(struct perf_event
*event
,
1055 struct perf_event_context
*ctx
, bool add
)
1062 * set default to be dependent on timer tick just
1063 * like original code
1065 #define PERF_CPU_HRTIMER (1000 / HZ)
1067 * function must be called with interrupts disabled
1069 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1071 struct perf_cpu_context
*cpuctx
;
1074 lockdep_assert_irqs_disabled();
1076 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1077 rotations
= perf_rotate_context(cpuctx
);
1079 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1081 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1083 cpuctx
->hrtimer_active
= 0;
1084 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1086 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1089 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1091 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1092 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1095 /* no multiplexing needed for SW PMU */
1096 if (pmu
->task_ctx_nr
== perf_sw_context
)
1100 * check default is sane, if not set then force to
1101 * default interval (1/tick)
1103 interval
= pmu
->hrtimer_interval_ms
;
1105 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1107 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1109 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1110 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1111 timer
->function
= perf_mux_hrtimer_handler
;
1114 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1116 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1117 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1118 unsigned long flags
;
1120 /* not for SW PMU */
1121 if (pmu
->task_ctx_nr
== perf_sw_context
)
1124 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1125 if (!cpuctx
->hrtimer_active
) {
1126 cpuctx
->hrtimer_active
= 1;
1127 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1128 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1130 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1135 void perf_pmu_disable(struct pmu
*pmu
)
1137 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1139 pmu
->pmu_disable(pmu
);
1142 void perf_pmu_enable(struct pmu
*pmu
)
1144 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1146 pmu
->pmu_enable(pmu
);
1149 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1152 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1153 * perf_event_task_tick() are fully serialized because they're strictly cpu
1154 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1155 * disabled, while perf_event_task_tick is called from IRQ context.
1157 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1159 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1161 lockdep_assert_irqs_disabled();
1163 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1165 list_add(&ctx
->active_ctx_list
, head
);
1168 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1170 lockdep_assert_irqs_disabled();
1172 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1174 list_del_init(&ctx
->active_ctx_list
);
1177 static void get_ctx(struct perf_event_context
*ctx
)
1179 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1182 static void free_ctx(struct rcu_head
*head
)
1184 struct perf_event_context
*ctx
;
1186 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1187 kfree(ctx
->task_ctx_data
);
1191 static void put_ctx(struct perf_event_context
*ctx
)
1193 if (atomic_dec_and_test(&ctx
->refcount
)) {
1194 if (ctx
->parent_ctx
)
1195 put_ctx(ctx
->parent_ctx
);
1196 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1197 put_task_struct(ctx
->task
);
1198 call_rcu(&ctx
->rcu_head
, free_ctx
);
1203 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1204 * perf_pmu_migrate_context() we need some magic.
1206 * Those places that change perf_event::ctx will hold both
1207 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1209 * Lock ordering is by mutex address. There are two other sites where
1210 * perf_event_context::mutex nests and those are:
1212 * - perf_event_exit_task_context() [ child , 0 ]
1213 * perf_event_exit_event()
1214 * put_event() [ parent, 1 ]
1216 * - perf_event_init_context() [ parent, 0 ]
1217 * inherit_task_group()
1220 * perf_event_alloc()
1222 * perf_try_init_event() [ child , 1 ]
1224 * While it appears there is an obvious deadlock here -- the parent and child
1225 * nesting levels are inverted between the two. This is in fact safe because
1226 * life-time rules separate them. That is an exiting task cannot fork, and a
1227 * spawning task cannot (yet) exit.
1229 * But remember that that these are parent<->child context relations, and
1230 * migration does not affect children, therefore these two orderings should not
1233 * The change in perf_event::ctx does not affect children (as claimed above)
1234 * because the sys_perf_event_open() case will install a new event and break
1235 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1236 * concerned with cpuctx and that doesn't have children.
1238 * The places that change perf_event::ctx will issue:
1240 * perf_remove_from_context();
1241 * synchronize_rcu();
1242 * perf_install_in_context();
1244 * to affect the change. The remove_from_context() + synchronize_rcu() should
1245 * quiesce the event, after which we can install it in the new location. This
1246 * means that only external vectors (perf_fops, prctl) can perturb the event
1247 * while in transit. Therefore all such accessors should also acquire
1248 * perf_event_context::mutex to serialize against this.
1250 * However; because event->ctx can change while we're waiting to acquire
1251 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1256 * task_struct::perf_event_mutex
1257 * perf_event_context::mutex
1258 * perf_event::child_mutex;
1259 * perf_event_context::lock
1260 * perf_event::mmap_mutex
1265 * cpuctx->mutex / perf_event_context::mutex
1267 static struct perf_event_context
*
1268 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1270 struct perf_event_context
*ctx
;
1274 ctx
= READ_ONCE(event
->ctx
);
1275 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1281 mutex_lock_nested(&ctx
->mutex
, nesting
);
1282 if (event
->ctx
!= ctx
) {
1283 mutex_unlock(&ctx
->mutex
);
1291 static inline struct perf_event_context
*
1292 perf_event_ctx_lock(struct perf_event
*event
)
1294 return perf_event_ctx_lock_nested(event
, 0);
1297 static void perf_event_ctx_unlock(struct perf_event
*event
,
1298 struct perf_event_context
*ctx
)
1300 mutex_unlock(&ctx
->mutex
);
1305 * This must be done under the ctx->lock, such as to serialize against
1306 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1307 * calling scheduler related locks and ctx->lock nests inside those.
1309 static __must_check
struct perf_event_context
*
1310 unclone_ctx(struct perf_event_context
*ctx
)
1312 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1314 lockdep_assert_held(&ctx
->lock
);
1317 ctx
->parent_ctx
= NULL
;
1323 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1328 * only top level events have the pid namespace they were created in
1331 event
= event
->parent
;
1333 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1334 /* avoid -1 if it is idle thread or runs in another ns */
1335 if (!nr
&& !pid_alive(p
))
1340 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1342 return perf_event_pid_type(event
, p
, __PIDTYPE_TGID
);
1345 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1347 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1351 * If we inherit events we want to return the parent event id
1354 static u64
primary_event_id(struct perf_event
*event
)
1359 id
= event
->parent
->id
;
1365 * Get the perf_event_context for a task and lock it.
1367 * This has to cope with with the fact that until it is locked,
1368 * the context could get moved to another task.
1370 static struct perf_event_context
*
1371 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1373 struct perf_event_context
*ctx
;
1377 * One of the few rules of preemptible RCU is that one cannot do
1378 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1379 * part of the read side critical section was irqs-enabled -- see
1380 * rcu_read_unlock_special().
1382 * Since ctx->lock nests under rq->lock we must ensure the entire read
1383 * side critical section has interrupts disabled.
1385 local_irq_save(*flags
);
1387 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1390 * If this context is a clone of another, it might
1391 * get swapped for another underneath us by
1392 * perf_event_task_sched_out, though the
1393 * rcu_read_lock() protects us from any context
1394 * getting freed. Lock the context and check if it
1395 * got swapped before we could get the lock, and retry
1396 * if so. If we locked the right context, then it
1397 * can't get swapped on us any more.
1399 raw_spin_lock(&ctx
->lock
);
1400 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1401 raw_spin_unlock(&ctx
->lock
);
1403 local_irq_restore(*flags
);
1407 if (ctx
->task
== TASK_TOMBSTONE
||
1408 !atomic_inc_not_zero(&ctx
->refcount
)) {
1409 raw_spin_unlock(&ctx
->lock
);
1412 WARN_ON_ONCE(ctx
->task
!= task
);
1417 local_irq_restore(*flags
);
1422 * Get the context for a task and increment its pin_count so it
1423 * can't get swapped to another task. This also increments its
1424 * reference count so that the context can't get freed.
1426 static struct perf_event_context
*
1427 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1429 struct perf_event_context
*ctx
;
1430 unsigned long flags
;
1432 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1435 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1440 static void perf_unpin_context(struct perf_event_context
*ctx
)
1442 unsigned long flags
;
1444 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1446 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1450 * Update the record of the current time in a context.
1452 static void update_context_time(struct perf_event_context
*ctx
)
1454 u64 now
= perf_clock();
1456 ctx
->time
+= now
- ctx
->timestamp
;
1457 ctx
->timestamp
= now
;
1460 static u64
perf_event_time(struct perf_event
*event
)
1462 struct perf_event_context
*ctx
= event
->ctx
;
1464 if (is_cgroup_event(event
))
1465 return perf_cgroup_event_time(event
);
1467 return ctx
? ctx
->time
: 0;
1470 static enum event_type_t
get_event_type(struct perf_event
*event
)
1472 struct perf_event_context
*ctx
= event
->ctx
;
1473 enum event_type_t event_type
;
1475 lockdep_assert_held(&ctx
->lock
);
1478 * It's 'group type', really, because if our group leader is
1479 * pinned, so are we.
1481 if (event
->group_leader
!= event
)
1482 event
= event
->group_leader
;
1484 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1486 event_type
|= EVENT_CPU
;
1491 static struct list_head
*
1492 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1494 if (event
->attr
.pinned
)
1495 return &ctx
->pinned_groups
;
1497 return &ctx
->flexible_groups
;
1501 * Add a event from the lists for its context.
1502 * Must be called with ctx->mutex and ctx->lock held.
1505 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1507 lockdep_assert_held(&ctx
->lock
);
1509 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1510 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1512 event
->tstamp
= perf_event_time(event
);
1515 * If we're a stand alone event or group leader, we go to the context
1516 * list, group events are kept attached to the group so that
1517 * perf_group_detach can, at all times, locate all siblings.
1519 if (event
->group_leader
== event
) {
1520 struct list_head
*list
;
1522 event
->group_caps
= event
->event_caps
;
1524 list
= ctx_group_list(event
, ctx
);
1525 list_add_tail(&event
->group_entry
, list
);
1528 list_update_cgroup_event(event
, ctx
, true);
1530 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1532 if (event
->attr
.inherit_stat
)
1539 * Initialize event state based on the perf_event_attr::disabled.
1541 static inline void perf_event__state_init(struct perf_event
*event
)
1543 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1544 PERF_EVENT_STATE_INACTIVE
;
1547 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1549 int entry
= sizeof(u64
); /* value */
1553 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1554 size
+= sizeof(u64
);
1556 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1557 size
+= sizeof(u64
);
1559 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1560 entry
+= sizeof(u64
);
1562 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1564 size
+= sizeof(u64
);
1568 event
->read_size
= size
;
1571 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1573 struct perf_sample_data
*data
;
1576 if (sample_type
& PERF_SAMPLE_IP
)
1577 size
+= sizeof(data
->ip
);
1579 if (sample_type
& PERF_SAMPLE_ADDR
)
1580 size
+= sizeof(data
->addr
);
1582 if (sample_type
& PERF_SAMPLE_PERIOD
)
1583 size
+= sizeof(data
->period
);
1585 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1586 size
+= sizeof(data
->weight
);
1588 if (sample_type
& PERF_SAMPLE_READ
)
1589 size
+= event
->read_size
;
1591 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1592 size
+= sizeof(data
->data_src
.val
);
1594 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1595 size
+= sizeof(data
->txn
);
1597 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1598 size
+= sizeof(data
->phys_addr
);
1600 event
->header_size
= size
;
1604 * Called at perf_event creation and when events are attached/detached from a
1607 static void perf_event__header_size(struct perf_event
*event
)
1609 __perf_event_read_size(event
,
1610 event
->group_leader
->nr_siblings
);
1611 __perf_event_header_size(event
, event
->attr
.sample_type
);
1614 static void perf_event__id_header_size(struct perf_event
*event
)
1616 struct perf_sample_data
*data
;
1617 u64 sample_type
= event
->attr
.sample_type
;
1620 if (sample_type
& PERF_SAMPLE_TID
)
1621 size
+= sizeof(data
->tid_entry
);
1623 if (sample_type
& PERF_SAMPLE_TIME
)
1624 size
+= sizeof(data
->time
);
1626 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1627 size
+= sizeof(data
->id
);
1629 if (sample_type
& PERF_SAMPLE_ID
)
1630 size
+= sizeof(data
->id
);
1632 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1633 size
+= sizeof(data
->stream_id
);
1635 if (sample_type
& PERF_SAMPLE_CPU
)
1636 size
+= sizeof(data
->cpu_entry
);
1638 event
->id_header_size
= size
;
1641 static bool perf_event_validate_size(struct perf_event
*event
)
1644 * The values computed here will be over-written when we actually
1647 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1648 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1649 perf_event__id_header_size(event
);
1652 * Sum the lot; should not exceed the 64k limit we have on records.
1653 * Conservative limit to allow for callchains and other variable fields.
1655 if (event
->read_size
+ event
->header_size
+
1656 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1662 static void perf_group_attach(struct perf_event
*event
)
1664 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1666 lockdep_assert_held(&event
->ctx
->lock
);
1669 * We can have double attach due to group movement in perf_event_open.
1671 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1674 event
->attach_state
|= PERF_ATTACH_GROUP
;
1676 if (group_leader
== event
)
1679 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1681 group_leader
->group_caps
&= event
->event_caps
;
1683 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1684 group_leader
->nr_siblings
++;
1686 perf_event__header_size(group_leader
);
1688 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1689 perf_event__header_size(pos
);
1693 * Remove a event from the lists for its context.
1694 * Must be called with ctx->mutex and ctx->lock held.
1697 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1699 WARN_ON_ONCE(event
->ctx
!= ctx
);
1700 lockdep_assert_held(&ctx
->lock
);
1703 * We can have double detach due to exit/hot-unplug + close.
1705 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1708 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1710 list_update_cgroup_event(event
, ctx
, false);
1713 if (event
->attr
.inherit_stat
)
1716 list_del_rcu(&event
->event_entry
);
1718 if (event
->group_leader
== event
)
1719 list_del_init(&event
->group_entry
);
1722 * If event was in error state, then keep it
1723 * that way, otherwise bogus counts will be
1724 * returned on read(). The only way to get out
1725 * of error state is by explicit re-enabling
1728 if (event
->state
> PERF_EVENT_STATE_OFF
)
1729 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1734 static void perf_group_detach(struct perf_event
*event
)
1736 struct perf_event
*sibling
, *tmp
;
1737 struct list_head
*list
= NULL
;
1739 lockdep_assert_held(&event
->ctx
->lock
);
1742 * We can have double detach due to exit/hot-unplug + close.
1744 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1747 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1750 * If this is a sibling, remove it from its group.
1752 if (event
->group_leader
!= event
) {
1753 list_del_init(&event
->group_entry
);
1754 event
->group_leader
->nr_siblings
--;
1758 if (!list_empty(&event
->group_entry
))
1759 list
= &event
->group_entry
;
1762 * If this was a group event with sibling events then
1763 * upgrade the siblings to singleton events by adding them
1764 * to whatever list we are on.
1766 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1768 list_move_tail(&sibling
->group_entry
, list
);
1769 sibling
->group_leader
= sibling
;
1771 /* Inherit group flags from the previous leader */
1772 sibling
->group_caps
= event
->group_caps
;
1774 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1778 perf_event__header_size(event
->group_leader
);
1780 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1781 perf_event__header_size(tmp
);
1784 static bool is_orphaned_event(struct perf_event
*event
)
1786 return event
->state
== PERF_EVENT_STATE_DEAD
;
1789 static inline int __pmu_filter_match(struct perf_event
*event
)
1791 struct pmu
*pmu
= event
->pmu
;
1792 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1796 * Check whether we should attempt to schedule an event group based on
1797 * PMU-specific filtering. An event group can consist of HW and SW events,
1798 * potentially with a SW leader, so we must check all the filters, to
1799 * determine whether a group is schedulable:
1801 static inline int pmu_filter_match(struct perf_event
*event
)
1803 struct perf_event
*child
;
1805 if (!__pmu_filter_match(event
))
1808 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1809 if (!__pmu_filter_match(child
))
1817 event_filter_match(struct perf_event
*event
)
1819 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1820 perf_cgroup_match(event
) && pmu_filter_match(event
);
1824 event_sched_out(struct perf_event
*event
,
1825 struct perf_cpu_context
*cpuctx
,
1826 struct perf_event_context
*ctx
)
1828 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
1830 WARN_ON_ONCE(event
->ctx
!= ctx
);
1831 lockdep_assert_held(&ctx
->lock
);
1833 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1836 perf_pmu_disable(event
->pmu
);
1838 event
->pmu
->del(event
, 0);
1841 if (event
->pending_disable
) {
1842 event
->pending_disable
= 0;
1843 state
= PERF_EVENT_STATE_OFF
;
1845 perf_event_set_state(event
, state
);
1847 if (!is_software_event(event
))
1848 cpuctx
->active_oncpu
--;
1849 if (!--ctx
->nr_active
)
1850 perf_event_ctx_deactivate(ctx
);
1851 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1853 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1854 cpuctx
->exclusive
= 0;
1856 perf_pmu_enable(event
->pmu
);
1860 group_sched_out(struct perf_event
*group_event
,
1861 struct perf_cpu_context
*cpuctx
,
1862 struct perf_event_context
*ctx
)
1864 struct perf_event
*event
;
1866 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1869 perf_pmu_disable(ctx
->pmu
);
1871 event_sched_out(group_event
, cpuctx
, ctx
);
1874 * Schedule out siblings (if any):
1876 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1877 event_sched_out(event
, cpuctx
, ctx
);
1879 perf_pmu_enable(ctx
->pmu
);
1881 if (group_event
->attr
.exclusive
)
1882 cpuctx
->exclusive
= 0;
1885 #define DETACH_GROUP 0x01UL
1888 * Cross CPU call to remove a performance event
1890 * We disable the event on the hardware level first. After that we
1891 * remove it from the context list.
1894 __perf_remove_from_context(struct perf_event
*event
,
1895 struct perf_cpu_context
*cpuctx
,
1896 struct perf_event_context
*ctx
,
1899 unsigned long flags
= (unsigned long)info
;
1901 if (ctx
->is_active
& EVENT_TIME
) {
1902 update_context_time(ctx
);
1903 update_cgrp_time_from_cpuctx(cpuctx
);
1906 event_sched_out(event
, cpuctx
, ctx
);
1907 if (flags
& DETACH_GROUP
)
1908 perf_group_detach(event
);
1909 list_del_event(event
, ctx
);
1911 if (!ctx
->nr_events
&& ctx
->is_active
) {
1914 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1915 cpuctx
->task_ctx
= NULL
;
1921 * Remove the event from a task's (or a CPU's) list of events.
1923 * If event->ctx is a cloned context, callers must make sure that
1924 * every task struct that event->ctx->task could possibly point to
1925 * remains valid. This is OK when called from perf_release since
1926 * that only calls us on the top-level context, which can't be a clone.
1927 * When called from perf_event_exit_task, it's OK because the
1928 * context has been detached from its task.
1930 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1932 struct perf_event_context
*ctx
= event
->ctx
;
1934 lockdep_assert_held(&ctx
->mutex
);
1936 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1939 * The above event_function_call() can NO-OP when it hits
1940 * TASK_TOMBSTONE. In that case we must already have been detached
1941 * from the context (by perf_event_exit_event()) but the grouping
1942 * might still be in-tact.
1944 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1945 if ((flags
& DETACH_GROUP
) &&
1946 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1948 * Since in that case we cannot possibly be scheduled, simply
1951 raw_spin_lock_irq(&ctx
->lock
);
1952 perf_group_detach(event
);
1953 raw_spin_unlock_irq(&ctx
->lock
);
1958 * Cross CPU call to disable a performance event
1960 static void __perf_event_disable(struct perf_event
*event
,
1961 struct perf_cpu_context
*cpuctx
,
1962 struct perf_event_context
*ctx
,
1965 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1968 if (ctx
->is_active
& EVENT_TIME
) {
1969 update_context_time(ctx
);
1970 update_cgrp_time_from_event(event
);
1973 if (event
== event
->group_leader
)
1974 group_sched_out(event
, cpuctx
, ctx
);
1976 event_sched_out(event
, cpuctx
, ctx
);
1978 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1984 * If event->ctx is a cloned context, callers must make sure that
1985 * every task struct that event->ctx->task could possibly point to
1986 * remains valid. This condition is satisifed when called through
1987 * perf_event_for_each_child or perf_event_for_each because they
1988 * hold the top-level event's child_mutex, so any descendant that
1989 * goes to exit will block in perf_event_exit_event().
1991 * When called from perf_pending_event it's OK because event->ctx
1992 * is the current context on this CPU and preemption is disabled,
1993 * hence we can't get into perf_event_task_sched_out for this context.
1995 static void _perf_event_disable(struct perf_event
*event
)
1997 struct perf_event_context
*ctx
= event
->ctx
;
1999 raw_spin_lock_irq(&ctx
->lock
);
2000 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2001 raw_spin_unlock_irq(&ctx
->lock
);
2004 raw_spin_unlock_irq(&ctx
->lock
);
2006 event_function_call(event
, __perf_event_disable
, NULL
);
2009 void perf_event_disable_local(struct perf_event
*event
)
2011 event_function_local(event
, __perf_event_disable
, NULL
);
2015 * Strictly speaking kernel users cannot create groups and therefore this
2016 * interface does not need the perf_event_ctx_lock() magic.
2018 void perf_event_disable(struct perf_event
*event
)
2020 struct perf_event_context
*ctx
;
2022 ctx
= perf_event_ctx_lock(event
);
2023 _perf_event_disable(event
);
2024 perf_event_ctx_unlock(event
, ctx
);
2026 EXPORT_SYMBOL_GPL(perf_event_disable
);
2028 void perf_event_disable_inatomic(struct perf_event
*event
)
2030 event
->pending_disable
= 1;
2031 irq_work_queue(&event
->pending
);
2034 static void perf_set_shadow_time(struct perf_event
*event
,
2035 struct perf_event_context
*ctx
)
2038 * use the correct time source for the time snapshot
2040 * We could get by without this by leveraging the
2041 * fact that to get to this function, the caller
2042 * has most likely already called update_context_time()
2043 * and update_cgrp_time_xx() and thus both timestamp
2044 * are identical (or very close). Given that tstamp is,
2045 * already adjusted for cgroup, we could say that:
2046 * tstamp - ctx->timestamp
2048 * tstamp - cgrp->timestamp.
2050 * Then, in perf_output_read(), the calculation would
2051 * work with no changes because:
2052 * - event is guaranteed scheduled in
2053 * - no scheduled out in between
2054 * - thus the timestamp would be the same
2056 * But this is a bit hairy.
2058 * So instead, we have an explicit cgroup call to remain
2059 * within the time time source all along. We believe it
2060 * is cleaner and simpler to understand.
2062 if (is_cgroup_event(event
))
2063 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2065 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2068 #define MAX_INTERRUPTS (~0ULL)
2070 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2071 static void perf_log_itrace_start(struct perf_event
*event
);
2074 event_sched_in(struct perf_event
*event
,
2075 struct perf_cpu_context
*cpuctx
,
2076 struct perf_event_context
*ctx
)
2080 lockdep_assert_held(&ctx
->lock
);
2082 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2085 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2087 * Order event::oncpu write to happen before the ACTIVE state is
2088 * visible. This allows perf_event_{stop,read}() to observe the correct
2089 * ->oncpu if it sees ACTIVE.
2092 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2095 * Unthrottle events, since we scheduled we might have missed several
2096 * ticks already, also for a heavily scheduling task there is little
2097 * guarantee it'll get a tick in a timely manner.
2099 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2100 perf_log_throttle(event
, 1);
2101 event
->hw
.interrupts
= 0;
2104 perf_pmu_disable(event
->pmu
);
2106 perf_set_shadow_time(event
, ctx
);
2108 perf_log_itrace_start(event
);
2110 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2111 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2117 if (!is_software_event(event
))
2118 cpuctx
->active_oncpu
++;
2119 if (!ctx
->nr_active
++)
2120 perf_event_ctx_activate(ctx
);
2121 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2124 if (event
->attr
.exclusive
)
2125 cpuctx
->exclusive
= 1;
2128 perf_pmu_enable(event
->pmu
);
2134 group_sched_in(struct perf_event
*group_event
,
2135 struct perf_cpu_context
*cpuctx
,
2136 struct perf_event_context
*ctx
)
2138 struct perf_event
*event
, *partial_group
= NULL
;
2139 struct pmu
*pmu
= ctx
->pmu
;
2141 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2144 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2146 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2147 pmu
->cancel_txn(pmu
);
2148 perf_mux_hrtimer_restart(cpuctx
);
2153 * Schedule in siblings as one group (if any):
2155 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2156 if (event_sched_in(event
, cpuctx
, ctx
)) {
2157 partial_group
= event
;
2162 if (!pmu
->commit_txn(pmu
))
2167 * Groups can be scheduled in as one unit only, so undo any
2168 * partial group before returning:
2169 * The events up to the failed event are scheduled out normally.
2171 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2172 if (event
== partial_group
)
2175 event_sched_out(event
, cpuctx
, ctx
);
2177 event_sched_out(group_event
, cpuctx
, ctx
);
2179 pmu
->cancel_txn(pmu
);
2181 perf_mux_hrtimer_restart(cpuctx
);
2187 * Work out whether we can put this event group on the CPU now.
2189 static int group_can_go_on(struct perf_event
*event
,
2190 struct perf_cpu_context
*cpuctx
,
2194 * Groups consisting entirely of software events can always go on.
2196 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2199 * If an exclusive group is already on, no other hardware
2202 if (cpuctx
->exclusive
)
2205 * If this group is exclusive and there are already
2206 * events on the CPU, it can't go on.
2208 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2211 * Otherwise, try to add it if all previous groups were able
2217 static void add_event_to_ctx(struct perf_event
*event
,
2218 struct perf_event_context
*ctx
)
2220 list_add_event(event
, ctx
);
2221 perf_group_attach(event
);
2224 static void ctx_sched_out(struct perf_event_context
*ctx
,
2225 struct perf_cpu_context
*cpuctx
,
2226 enum event_type_t event_type
);
2228 ctx_sched_in(struct perf_event_context
*ctx
,
2229 struct perf_cpu_context
*cpuctx
,
2230 enum event_type_t event_type
,
2231 struct task_struct
*task
);
2233 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2234 struct perf_event_context
*ctx
,
2235 enum event_type_t event_type
)
2237 if (!cpuctx
->task_ctx
)
2240 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2243 ctx_sched_out(ctx
, cpuctx
, event_type
);
2246 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2247 struct perf_event_context
*ctx
,
2248 struct task_struct
*task
)
2250 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2252 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2253 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2255 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2259 * We want to maintain the following priority of scheduling:
2260 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2261 * - task pinned (EVENT_PINNED)
2262 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2263 * - task flexible (EVENT_FLEXIBLE).
2265 * In order to avoid unscheduling and scheduling back in everything every
2266 * time an event is added, only do it for the groups of equal priority and
2269 * This can be called after a batch operation on task events, in which case
2270 * event_type is a bit mask of the types of events involved. For CPU events,
2271 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2273 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2274 struct perf_event_context
*task_ctx
,
2275 enum event_type_t event_type
)
2277 enum event_type_t ctx_event_type
;
2278 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2281 * If pinned groups are involved, flexible groups also need to be
2284 if (event_type
& EVENT_PINNED
)
2285 event_type
|= EVENT_FLEXIBLE
;
2287 ctx_event_type
= event_type
& EVENT_ALL
;
2289 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2291 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2294 * Decide which cpu ctx groups to schedule out based on the types
2295 * of events that caused rescheduling:
2296 * - EVENT_CPU: schedule out corresponding groups;
2297 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2298 * - otherwise, do nothing more.
2301 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2302 else if (ctx_event_type
& EVENT_PINNED
)
2303 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2305 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2306 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2310 * Cross CPU call to install and enable a performance event
2312 * Very similar to remote_function() + event_function() but cannot assume that
2313 * things like ctx->is_active and cpuctx->task_ctx are set.
2315 static int __perf_install_in_context(void *info
)
2317 struct perf_event
*event
= info
;
2318 struct perf_event_context
*ctx
= event
->ctx
;
2319 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2320 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2321 bool reprogram
= true;
2324 raw_spin_lock(&cpuctx
->ctx
.lock
);
2326 raw_spin_lock(&ctx
->lock
);
2329 reprogram
= (ctx
->task
== current
);
2332 * If the task is running, it must be running on this CPU,
2333 * otherwise we cannot reprogram things.
2335 * If its not running, we don't care, ctx->lock will
2336 * serialize against it becoming runnable.
2338 if (task_curr(ctx
->task
) && !reprogram
) {
2343 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2344 } else if (task_ctx
) {
2345 raw_spin_lock(&task_ctx
->lock
);
2348 #ifdef CONFIG_CGROUP_PERF
2349 if (is_cgroup_event(event
)) {
2351 * If the current cgroup doesn't match the event's
2352 * cgroup, we should not try to schedule it.
2354 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2355 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2356 event
->cgrp
->css
.cgroup
);
2361 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2362 add_event_to_ctx(event
, ctx
);
2363 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2365 add_event_to_ctx(event
, ctx
);
2369 perf_ctx_unlock(cpuctx
, task_ctx
);
2375 * Attach a performance event to a context.
2377 * Very similar to event_function_call, see comment there.
2380 perf_install_in_context(struct perf_event_context
*ctx
,
2381 struct perf_event
*event
,
2384 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2386 lockdep_assert_held(&ctx
->mutex
);
2388 if (event
->cpu
!= -1)
2392 * Ensures that if we can observe event->ctx, both the event and ctx
2393 * will be 'complete'. See perf_iterate_sb_cpu().
2395 smp_store_release(&event
->ctx
, ctx
);
2398 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2403 * Should not happen, we validate the ctx is still alive before calling.
2405 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2409 * Installing events is tricky because we cannot rely on ctx->is_active
2410 * to be set in case this is the nr_events 0 -> 1 transition.
2412 * Instead we use task_curr(), which tells us if the task is running.
2413 * However, since we use task_curr() outside of rq::lock, we can race
2414 * against the actual state. This means the result can be wrong.
2416 * If we get a false positive, we retry, this is harmless.
2418 * If we get a false negative, things are complicated. If we are after
2419 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2420 * value must be correct. If we're before, it doesn't matter since
2421 * perf_event_context_sched_in() will program the counter.
2423 * However, this hinges on the remote context switch having observed
2424 * our task->perf_event_ctxp[] store, such that it will in fact take
2425 * ctx::lock in perf_event_context_sched_in().
2427 * We do this by task_function_call(), if the IPI fails to hit the task
2428 * we know any future context switch of task must see the
2429 * perf_event_ctpx[] store.
2433 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2434 * task_cpu() load, such that if the IPI then does not find the task
2435 * running, a future context switch of that task must observe the
2440 if (!task_function_call(task
, __perf_install_in_context
, event
))
2443 raw_spin_lock_irq(&ctx
->lock
);
2445 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2447 * Cannot happen because we already checked above (which also
2448 * cannot happen), and we hold ctx->mutex, which serializes us
2449 * against perf_event_exit_task_context().
2451 raw_spin_unlock_irq(&ctx
->lock
);
2455 * If the task is not running, ctx->lock will avoid it becoming so,
2456 * thus we can safely install the event.
2458 if (task_curr(task
)) {
2459 raw_spin_unlock_irq(&ctx
->lock
);
2462 add_event_to_ctx(event
, ctx
);
2463 raw_spin_unlock_irq(&ctx
->lock
);
2467 * Cross CPU call to enable a performance event
2469 static void __perf_event_enable(struct perf_event
*event
,
2470 struct perf_cpu_context
*cpuctx
,
2471 struct perf_event_context
*ctx
,
2474 struct perf_event
*leader
= event
->group_leader
;
2475 struct perf_event_context
*task_ctx
;
2477 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2478 event
->state
<= PERF_EVENT_STATE_ERROR
)
2482 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2484 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2486 if (!ctx
->is_active
)
2489 if (!event_filter_match(event
)) {
2490 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2495 * If the event is in a group and isn't the group leader,
2496 * then don't put it on unless the group is on.
2498 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2499 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2503 task_ctx
= cpuctx
->task_ctx
;
2505 WARN_ON_ONCE(task_ctx
!= ctx
);
2507 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2513 * If event->ctx is a cloned context, callers must make sure that
2514 * every task struct that event->ctx->task could possibly point to
2515 * remains valid. This condition is satisfied when called through
2516 * perf_event_for_each_child or perf_event_for_each as described
2517 * for perf_event_disable.
2519 static void _perf_event_enable(struct perf_event
*event
)
2521 struct perf_event_context
*ctx
= event
->ctx
;
2523 raw_spin_lock_irq(&ctx
->lock
);
2524 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2525 event
->state
< PERF_EVENT_STATE_ERROR
) {
2526 raw_spin_unlock_irq(&ctx
->lock
);
2531 * If the event is in error state, clear that first.
2533 * That way, if we see the event in error state below, we know that it
2534 * has gone back into error state, as distinct from the task having
2535 * been scheduled away before the cross-call arrived.
2537 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2538 event
->state
= PERF_EVENT_STATE_OFF
;
2539 raw_spin_unlock_irq(&ctx
->lock
);
2541 event_function_call(event
, __perf_event_enable
, NULL
);
2545 * See perf_event_disable();
2547 void perf_event_enable(struct perf_event
*event
)
2549 struct perf_event_context
*ctx
;
2551 ctx
= perf_event_ctx_lock(event
);
2552 _perf_event_enable(event
);
2553 perf_event_ctx_unlock(event
, ctx
);
2555 EXPORT_SYMBOL_GPL(perf_event_enable
);
2557 struct stop_event_data
{
2558 struct perf_event
*event
;
2559 unsigned int restart
;
2562 static int __perf_event_stop(void *info
)
2564 struct stop_event_data
*sd
= info
;
2565 struct perf_event
*event
= sd
->event
;
2567 /* if it's already INACTIVE, do nothing */
2568 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2571 /* matches smp_wmb() in event_sched_in() */
2575 * There is a window with interrupts enabled before we get here,
2576 * so we need to check again lest we try to stop another CPU's event.
2578 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2581 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2584 * May race with the actual stop (through perf_pmu_output_stop()),
2585 * but it is only used for events with AUX ring buffer, and such
2586 * events will refuse to restart because of rb::aux_mmap_count==0,
2587 * see comments in perf_aux_output_begin().
2589 * Since this is happening on a event-local CPU, no trace is lost
2593 event
->pmu
->start(event
, 0);
2598 static int perf_event_stop(struct perf_event
*event
, int restart
)
2600 struct stop_event_data sd
= {
2607 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2610 /* matches smp_wmb() in event_sched_in() */
2614 * We only want to restart ACTIVE events, so if the event goes
2615 * inactive here (event->oncpu==-1), there's nothing more to do;
2616 * fall through with ret==-ENXIO.
2618 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2619 __perf_event_stop
, &sd
);
2620 } while (ret
== -EAGAIN
);
2626 * In order to contain the amount of racy and tricky in the address filter
2627 * configuration management, it is a two part process:
2629 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2630 * we update the addresses of corresponding vmas in
2631 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2632 * (p2) when an event is scheduled in (pmu::add), it calls
2633 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2634 * if the generation has changed since the previous call.
2636 * If (p1) happens while the event is active, we restart it to force (p2).
2638 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2639 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2641 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2642 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2644 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2647 void perf_event_addr_filters_sync(struct perf_event
*event
)
2649 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2651 if (!has_addr_filter(event
))
2654 raw_spin_lock(&ifh
->lock
);
2655 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2656 event
->pmu
->addr_filters_sync(event
);
2657 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2659 raw_spin_unlock(&ifh
->lock
);
2661 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2663 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2666 * not supported on inherited events
2668 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2671 atomic_add(refresh
, &event
->event_limit
);
2672 _perf_event_enable(event
);
2678 * See perf_event_disable()
2680 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2682 struct perf_event_context
*ctx
;
2685 ctx
= perf_event_ctx_lock(event
);
2686 ret
= _perf_event_refresh(event
, refresh
);
2687 perf_event_ctx_unlock(event
, ctx
);
2691 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2693 static void ctx_sched_out(struct perf_event_context
*ctx
,
2694 struct perf_cpu_context
*cpuctx
,
2695 enum event_type_t event_type
)
2697 int is_active
= ctx
->is_active
;
2698 struct perf_event
*event
;
2700 lockdep_assert_held(&ctx
->lock
);
2702 if (likely(!ctx
->nr_events
)) {
2704 * See __perf_remove_from_context().
2706 WARN_ON_ONCE(ctx
->is_active
);
2708 WARN_ON_ONCE(cpuctx
->task_ctx
);
2712 ctx
->is_active
&= ~event_type
;
2713 if (!(ctx
->is_active
& EVENT_ALL
))
2717 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2718 if (!ctx
->is_active
)
2719 cpuctx
->task_ctx
= NULL
;
2723 * Always update time if it was set; not only when it changes.
2724 * Otherwise we can 'forget' to update time for any but the last
2725 * context we sched out. For example:
2727 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2728 * ctx_sched_out(.event_type = EVENT_PINNED)
2730 * would only update time for the pinned events.
2732 if (is_active
& EVENT_TIME
) {
2733 /* update (and stop) ctx time */
2734 update_context_time(ctx
);
2735 update_cgrp_time_from_cpuctx(cpuctx
);
2738 is_active
^= ctx
->is_active
; /* changed bits */
2740 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2743 perf_pmu_disable(ctx
->pmu
);
2744 if (is_active
& EVENT_PINNED
) {
2745 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2746 group_sched_out(event
, cpuctx
, ctx
);
2749 if (is_active
& EVENT_FLEXIBLE
) {
2750 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2751 group_sched_out(event
, cpuctx
, ctx
);
2753 perf_pmu_enable(ctx
->pmu
);
2757 * Test whether two contexts are equivalent, i.e. whether they have both been
2758 * cloned from the same version of the same context.
2760 * Equivalence is measured using a generation number in the context that is
2761 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2762 * and list_del_event().
2764 static int context_equiv(struct perf_event_context
*ctx1
,
2765 struct perf_event_context
*ctx2
)
2767 lockdep_assert_held(&ctx1
->lock
);
2768 lockdep_assert_held(&ctx2
->lock
);
2770 /* Pinning disables the swap optimization */
2771 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2774 /* If ctx1 is the parent of ctx2 */
2775 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2778 /* If ctx2 is the parent of ctx1 */
2779 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2783 * If ctx1 and ctx2 have the same parent; we flatten the parent
2784 * hierarchy, see perf_event_init_context().
2786 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2787 ctx1
->parent_gen
== ctx2
->parent_gen
)
2794 static void __perf_event_sync_stat(struct perf_event
*event
,
2795 struct perf_event
*next_event
)
2799 if (!event
->attr
.inherit_stat
)
2803 * Update the event value, we cannot use perf_event_read()
2804 * because we're in the middle of a context switch and have IRQs
2805 * disabled, which upsets smp_call_function_single(), however
2806 * we know the event must be on the current CPU, therefore we
2807 * don't need to use it.
2809 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2810 event
->pmu
->read(event
);
2812 perf_event_update_time(event
);
2815 * In order to keep per-task stats reliable we need to flip the event
2816 * values when we flip the contexts.
2818 value
= local64_read(&next_event
->count
);
2819 value
= local64_xchg(&event
->count
, value
);
2820 local64_set(&next_event
->count
, value
);
2822 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2823 swap(event
->total_time_running
, next_event
->total_time_running
);
2826 * Since we swizzled the values, update the user visible data too.
2828 perf_event_update_userpage(event
);
2829 perf_event_update_userpage(next_event
);
2832 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2833 struct perf_event_context
*next_ctx
)
2835 struct perf_event
*event
, *next_event
;
2840 update_context_time(ctx
);
2842 event
= list_first_entry(&ctx
->event_list
,
2843 struct perf_event
, event_entry
);
2845 next_event
= list_first_entry(&next_ctx
->event_list
,
2846 struct perf_event
, event_entry
);
2848 while (&event
->event_entry
!= &ctx
->event_list
&&
2849 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2851 __perf_event_sync_stat(event
, next_event
);
2853 event
= list_next_entry(event
, event_entry
);
2854 next_event
= list_next_entry(next_event
, event_entry
);
2858 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2859 struct task_struct
*next
)
2861 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2862 struct perf_event_context
*next_ctx
;
2863 struct perf_event_context
*parent
, *next_parent
;
2864 struct perf_cpu_context
*cpuctx
;
2870 cpuctx
= __get_cpu_context(ctx
);
2871 if (!cpuctx
->task_ctx
)
2875 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2879 parent
= rcu_dereference(ctx
->parent_ctx
);
2880 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2882 /* If neither context have a parent context; they cannot be clones. */
2883 if (!parent
&& !next_parent
)
2886 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2888 * Looks like the two contexts are clones, so we might be
2889 * able to optimize the context switch. We lock both
2890 * contexts and check that they are clones under the
2891 * lock (including re-checking that neither has been
2892 * uncloned in the meantime). It doesn't matter which
2893 * order we take the locks because no other cpu could
2894 * be trying to lock both of these tasks.
2896 raw_spin_lock(&ctx
->lock
);
2897 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2898 if (context_equiv(ctx
, next_ctx
)) {
2899 WRITE_ONCE(ctx
->task
, next
);
2900 WRITE_ONCE(next_ctx
->task
, task
);
2902 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2905 * RCU_INIT_POINTER here is safe because we've not
2906 * modified the ctx and the above modification of
2907 * ctx->task and ctx->task_ctx_data are immaterial
2908 * since those values are always verified under
2909 * ctx->lock which we're now holding.
2911 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2912 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2916 perf_event_sync_stat(ctx
, next_ctx
);
2918 raw_spin_unlock(&next_ctx
->lock
);
2919 raw_spin_unlock(&ctx
->lock
);
2925 raw_spin_lock(&ctx
->lock
);
2926 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2927 raw_spin_unlock(&ctx
->lock
);
2931 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2933 void perf_sched_cb_dec(struct pmu
*pmu
)
2935 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2937 this_cpu_dec(perf_sched_cb_usages
);
2939 if (!--cpuctx
->sched_cb_usage
)
2940 list_del(&cpuctx
->sched_cb_entry
);
2944 void perf_sched_cb_inc(struct pmu
*pmu
)
2946 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2948 if (!cpuctx
->sched_cb_usage
++)
2949 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2951 this_cpu_inc(perf_sched_cb_usages
);
2955 * This function provides the context switch callback to the lower code
2956 * layer. It is invoked ONLY when the context switch callback is enabled.
2958 * This callback is relevant even to per-cpu events; for example multi event
2959 * PEBS requires this to provide PID/TID information. This requires we flush
2960 * all queued PEBS records before we context switch to a new task.
2962 static void perf_pmu_sched_task(struct task_struct
*prev
,
2963 struct task_struct
*next
,
2966 struct perf_cpu_context
*cpuctx
;
2972 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2973 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2975 if (WARN_ON_ONCE(!pmu
->sched_task
))
2978 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2979 perf_pmu_disable(pmu
);
2981 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2983 perf_pmu_enable(pmu
);
2984 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2988 static void perf_event_switch(struct task_struct
*task
,
2989 struct task_struct
*next_prev
, bool sched_in
);
2991 #define for_each_task_context_nr(ctxn) \
2992 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2995 * Called from scheduler to remove the events of the current task,
2996 * with interrupts disabled.
2998 * We stop each event and update the event value in event->count.
3000 * This does not protect us against NMI, but disable()
3001 * sets the disabled bit in the control field of event _before_
3002 * accessing the event control register. If a NMI hits, then it will
3003 * not restart the event.
3005 void __perf_event_task_sched_out(struct task_struct
*task
,
3006 struct task_struct
*next
)
3010 if (__this_cpu_read(perf_sched_cb_usages
))
3011 perf_pmu_sched_task(task
, next
, false);
3013 if (atomic_read(&nr_switch_events
))
3014 perf_event_switch(task
, next
, false);
3016 for_each_task_context_nr(ctxn
)
3017 perf_event_context_sched_out(task
, ctxn
, next
);
3020 * if cgroup events exist on this CPU, then we need
3021 * to check if we have to switch out PMU state.
3022 * cgroup event are system-wide mode only
3024 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3025 perf_cgroup_sched_out(task
, next
);
3029 * Called with IRQs disabled
3031 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3032 enum event_type_t event_type
)
3034 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3038 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3039 struct perf_cpu_context
*cpuctx
)
3041 struct perf_event
*event
;
3043 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3044 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3046 if (!event_filter_match(event
))
3049 if (group_can_go_on(event
, cpuctx
, 1))
3050 group_sched_in(event
, cpuctx
, ctx
);
3053 * If this pinned group hasn't been scheduled,
3054 * put it in error state.
3056 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3057 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3062 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3063 struct perf_cpu_context
*cpuctx
)
3065 struct perf_event
*event
;
3068 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3069 /* Ignore events in OFF or ERROR state */
3070 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3073 * Listen to the 'cpu' scheduling filter constraint
3076 if (!event_filter_match(event
))
3079 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3080 if (group_sched_in(event
, cpuctx
, ctx
))
3087 ctx_sched_in(struct perf_event_context
*ctx
,
3088 struct perf_cpu_context
*cpuctx
,
3089 enum event_type_t event_type
,
3090 struct task_struct
*task
)
3092 int is_active
= ctx
->is_active
;
3095 lockdep_assert_held(&ctx
->lock
);
3097 if (likely(!ctx
->nr_events
))
3100 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3103 cpuctx
->task_ctx
= ctx
;
3105 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3108 is_active
^= ctx
->is_active
; /* changed bits */
3110 if (is_active
& EVENT_TIME
) {
3111 /* start ctx time */
3113 ctx
->timestamp
= now
;
3114 perf_cgroup_set_timestamp(task
, ctx
);
3118 * First go through the list and put on any pinned groups
3119 * in order to give them the best chance of going on.
3121 if (is_active
& EVENT_PINNED
)
3122 ctx_pinned_sched_in(ctx
, cpuctx
);
3124 /* Then walk through the lower prio flexible groups */
3125 if (is_active
& EVENT_FLEXIBLE
)
3126 ctx_flexible_sched_in(ctx
, cpuctx
);
3129 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3130 enum event_type_t event_type
,
3131 struct task_struct
*task
)
3133 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3135 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3138 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3139 struct task_struct
*task
)
3141 struct perf_cpu_context
*cpuctx
;
3143 cpuctx
= __get_cpu_context(ctx
);
3144 if (cpuctx
->task_ctx
== ctx
)
3147 perf_ctx_lock(cpuctx
, ctx
);
3149 * We must check ctx->nr_events while holding ctx->lock, such
3150 * that we serialize against perf_install_in_context().
3152 if (!ctx
->nr_events
)
3155 perf_pmu_disable(ctx
->pmu
);
3157 * We want to keep the following priority order:
3158 * cpu pinned (that don't need to move), task pinned,
3159 * cpu flexible, task flexible.
3161 * However, if task's ctx is not carrying any pinned
3162 * events, no need to flip the cpuctx's events around.
3164 if (!list_empty(&ctx
->pinned_groups
))
3165 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3166 perf_event_sched_in(cpuctx
, ctx
, task
);
3167 perf_pmu_enable(ctx
->pmu
);
3170 perf_ctx_unlock(cpuctx
, ctx
);
3174 * Called from scheduler to add the events of the current task
3175 * with interrupts disabled.
3177 * We restore the event value and then enable it.
3179 * This does not protect us against NMI, but enable()
3180 * sets the enabled bit in the control field of event _before_
3181 * accessing the event control register. If a NMI hits, then it will
3182 * keep the event running.
3184 void __perf_event_task_sched_in(struct task_struct
*prev
,
3185 struct task_struct
*task
)
3187 struct perf_event_context
*ctx
;
3191 * If cgroup events exist on this CPU, then we need to check if we have
3192 * to switch in PMU state; cgroup event are system-wide mode only.
3194 * Since cgroup events are CPU events, we must schedule these in before
3195 * we schedule in the task events.
3197 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3198 perf_cgroup_sched_in(prev
, task
);
3200 for_each_task_context_nr(ctxn
) {
3201 ctx
= task
->perf_event_ctxp
[ctxn
];
3205 perf_event_context_sched_in(ctx
, task
);
3208 if (atomic_read(&nr_switch_events
))
3209 perf_event_switch(task
, prev
, true);
3211 if (__this_cpu_read(perf_sched_cb_usages
))
3212 perf_pmu_sched_task(prev
, task
, true);
3215 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3217 u64 frequency
= event
->attr
.sample_freq
;
3218 u64 sec
= NSEC_PER_SEC
;
3219 u64 divisor
, dividend
;
3221 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3223 count_fls
= fls64(count
);
3224 nsec_fls
= fls64(nsec
);
3225 frequency_fls
= fls64(frequency
);
3229 * We got @count in @nsec, with a target of sample_freq HZ
3230 * the target period becomes:
3233 * period = -------------------
3234 * @nsec * sample_freq
3239 * Reduce accuracy by one bit such that @a and @b converge
3240 * to a similar magnitude.
3242 #define REDUCE_FLS(a, b) \
3244 if (a##_fls > b##_fls) { \
3254 * Reduce accuracy until either term fits in a u64, then proceed with
3255 * the other, so that finally we can do a u64/u64 division.
3257 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3258 REDUCE_FLS(nsec
, frequency
);
3259 REDUCE_FLS(sec
, count
);
3262 if (count_fls
+ sec_fls
> 64) {
3263 divisor
= nsec
* frequency
;
3265 while (count_fls
+ sec_fls
> 64) {
3266 REDUCE_FLS(count
, sec
);
3270 dividend
= count
* sec
;
3272 dividend
= count
* sec
;
3274 while (nsec_fls
+ frequency_fls
> 64) {
3275 REDUCE_FLS(nsec
, frequency
);
3279 divisor
= nsec
* frequency
;
3285 return div64_u64(dividend
, divisor
);
3288 static DEFINE_PER_CPU(int, perf_throttled_count
);
3289 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3291 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3293 struct hw_perf_event
*hwc
= &event
->hw
;
3294 s64 period
, sample_period
;
3297 period
= perf_calculate_period(event
, nsec
, count
);
3299 delta
= (s64
)(period
- hwc
->sample_period
);
3300 delta
= (delta
+ 7) / 8; /* low pass filter */
3302 sample_period
= hwc
->sample_period
+ delta
;
3307 hwc
->sample_period
= sample_period
;
3309 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3311 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3313 local64_set(&hwc
->period_left
, 0);
3316 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3321 * combine freq adjustment with unthrottling to avoid two passes over the
3322 * events. At the same time, make sure, having freq events does not change
3323 * the rate of unthrottling as that would introduce bias.
3325 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3328 struct perf_event
*event
;
3329 struct hw_perf_event
*hwc
;
3330 u64 now
, period
= TICK_NSEC
;
3334 * only need to iterate over all events iff:
3335 * - context have events in frequency mode (needs freq adjust)
3336 * - there are events to unthrottle on this cpu
3338 if (!(ctx
->nr_freq
|| needs_unthr
))
3341 raw_spin_lock(&ctx
->lock
);
3342 perf_pmu_disable(ctx
->pmu
);
3344 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3345 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3348 if (!event_filter_match(event
))
3351 perf_pmu_disable(event
->pmu
);
3355 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3356 hwc
->interrupts
= 0;
3357 perf_log_throttle(event
, 1);
3358 event
->pmu
->start(event
, 0);
3361 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3365 * stop the event and update event->count
3367 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3369 now
= local64_read(&event
->count
);
3370 delta
= now
- hwc
->freq_count_stamp
;
3371 hwc
->freq_count_stamp
= now
;
3375 * reload only if value has changed
3376 * we have stopped the event so tell that
3377 * to perf_adjust_period() to avoid stopping it
3381 perf_adjust_period(event
, period
, delta
, false);
3383 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3385 perf_pmu_enable(event
->pmu
);
3388 perf_pmu_enable(ctx
->pmu
);
3389 raw_spin_unlock(&ctx
->lock
);
3393 * Round-robin a context's events:
3395 static void rotate_ctx(struct perf_event_context
*ctx
)
3398 * Rotate the first entry last of non-pinned groups. Rotation might be
3399 * disabled by the inheritance code.
3401 if (!ctx
->rotate_disable
)
3402 list_rotate_left(&ctx
->flexible_groups
);
3405 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3407 struct perf_event_context
*ctx
= NULL
;
3410 if (cpuctx
->ctx
.nr_events
) {
3411 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3415 ctx
= cpuctx
->task_ctx
;
3416 if (ctx
&& ctx
->nr_events
) {
3417 if (ctx
->nr_events
!= ctx
->nr_active
)
3424 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3425 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3427 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3429 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3431 rotate_ctx(&cpuctx
->ctx
);
3435 perf_event_sched_in(cpuctx
, ctx
, current
);
3437 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3438 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3444 void perf_event_task_tick(void)
3446 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3447 struct perf_event_context
*ctx
, *tmp
;
3450 lockdep_assert_irqs_disabled();
3452 __this_cpu_inc(perf_throttled_seq
);
3453 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3454 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3456 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3457 perf_adjust_freq_unthr_context(ctx
, throttled
);
3460 static int event_enable_on_exec(struct perf_event
*event
,
3461 struct perf_event_context
*ctx
)
3463 if (!event
->attr
.enable_on_exec
)
3466 event
->attr
.enable_on_exec
= 0;
3467 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3470 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3476 * Enable all of a task's events that have been marked enable-on-exec.
3477 * This expects task == current.
3479 static void perf_event_enable_on_exec(int ctxn
)
3481 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3482 enum event_type_t event_type
= 0;
3483 struct perf_cpu_context
*cpuctx
;
3484 struct perf_event
*event
;
3485 unsigned long flags
;
3488 local_irq_save(flags
);
3489 ctx
= current
->perf_event_ctxp
[ctxn
];
3490 if (!ctx
|| !ctx
->nr_events
)
3493 cpuctx
= __get_cpu_context(ctx
);
3494 perf_ctx_lock(cpuctx
, ctx
);
3495 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3496 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3497 enabled
|= event_enable_on_exec(event
, ctx
);
3498 event_type
|= get_event_type(event
);
3502 * Unclone and reschedule this context if we enabled any event.
3505 clone_ctx
= unclone_ctx(ctx
);
3506 ctx_resched(cpuctx
, ctx
, event_type
);
3508 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3510 perf_ctx_unlock(cpuctx
, ctx
);
3513 local_irq_restore(flags
);
3519 struct perf_read_data
{
3520 struct perf_event
*event
;
3525 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3527 u16 local_pkg
, event_pkg
;
3529 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3530 int local_cpu
= smp_processor_id();
3532 event_pkg
= topology_physical_package_id(event_cpu
);
3533 local_pkg
= topology_physical_package_id(local_cpu
);
3535 if (event_pkg
== local_pkg
)
3543 * Cross CPU call to read the hardware event
3545 static void __perf_event_read(void *info
)
3547 struct perf_read_data
*data
= info
;
3548 struct perf_event
*sub
, *event
= data
->event
;
3549 struct perf_event_context
*ctx
= event
->ctx
;
3550 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3551 struct pmu
*pmu
= event
->pmu
;
3554 * If this is a task context, we need to check whether it is
3555 * the current task context of this cpu. If not it has been
3556 * scheduled out before the smp call arrived. In that case
3557 * event->count would have been updated to a recent sample
3558 * when the event was scheduled out.
3560 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3563 raw_spin_lock(&ctx
->lock
);
3564 if (ctx
->is_active
& EVENT_TIME
) {
3565 update_context_time(ctx
);
3566 update_cgrp_time_from_event(event
);
3569 perf_event_update_time(event
);
3571 perf_event_update_sibling_time(event
);
3573 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3582 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3586 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3587 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3589 * Use sibling's PMU rather than @event's since
3590 * sibling could be on different (eg: software) PMU.
3592 sub
->pmu
->read(sub
);
3596 data
->ret
= pmu
->commit_txn(pmu
);
3599 raw_spin_unlock(&ctx
->lock
);
3602 static inline u64
perf_event_count(struct perf_event
*event
)
3604 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3608 * NMI-safe method to read a local event, that is an event that
3610 * - either for the current task, or for this CPU
3611 * - does not have inherit set, for inherited task events
3612 * will not be local and we cannot read them atomically
3613 * - must not have a pmu::count method
3615 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
3616 u64
*enabled
, u64
*running
)
3618 unsigned long flags
;
3622 * Disabling interrupts avoids all counter scheduling (context
3623 * switches, timer based rotation and IPIs).
3625 local_irq_save(flags
);
3628 * It must not be an event with inherit set, we cannot read
3629 * all child counters from atomic context.
3631 if (event
->attr
.inherit
) {
3636 /* If this is a per-task event, it must be for current */
3637 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3638 event
->hw
.target
!= current
) {
3643 /* If this is a per-CPU event, it must be for this CPU */
3644 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3645 event
->cpu
!= smp_processor_id()) {
3651 * If the event is currently on this CPU, its either a per-task event,
3652 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3655 if (event
->oncpu
== smp_processor_id())
3656 event
->pmu
->read(event
);
3658 *value
= local64_read(&event
->count
);
3659 if (enabled
|| running
) {
3660 u64 now
= event
->shadow_ctx_time
+ perf_clock();
3661 u64 __enabled
, __running
;
3663 __perf_update_times(event
, now
, &__enabled
, &__running
);
3665 *enabled
= __enabled
;
3667 *running
= __running
;
3670 local_irq_restore(flags
);
3675 static int perf_event_read(struct perf_event
*event
, bool group
)
3677 enum perf_event_state state
= READ_ONCE(event
->state
);
3678 int event_cpu
, ret
= 0;
3681 * If event is enabled and currently active on a CPU, update the
3682 * value in the event structure:
3685 if (state
== PERF_EVENT_STATE_ACTIVE
) {
3686 struct perf_read_data data
;
3689 * Orders the ->state and ->oncpu loads such that if we see
3690 * ACTIVE we must also see the right ->oncpu.
3692 * Matches the smp_wmb() from event_sched_in().
3696 event_cpu
= READ_ONCE(event
->oncpu
);
3697 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3700 data
= (struct perf_read_data
){
3707 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3710 * Purposely ignore the smp_call_function_single() return
3713 * If event_cpu isn't a valid CPU it means the event got
3714 * scheduled out and that will have updated the event count.
3716 * Therefore, either way, we'll have an up-to-date event count
3719 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3723 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
3724 struct perf_event_context
*ctx
= event
->ctx
;
3725 unsigned long flags
;
3727 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3728 state
= event
->state
;
3729 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
3730 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3735 * May read while context is not active (e.g., thread is
3736 * blocked), in that case we cannot update context time
3738 if (ctx
->is_active
& EVENT_TIME
) {
3739 update_context_time(ctx
);
3740 update_cgrp_time_from_event(event
);
3743 perf_event_update_time(event
);
3745 perf_event_update_sibling_time(event
);
3746 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3753 * Initialize the perf_event context in a task_struct:
3755 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3757 raw_spin_lock_init(&ctx
->lock
);
3758 mutex_init(&ctx
->mutex
);
3759 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3760 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3761 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3762 INIT_LIST_HEAD(&ctx
->event_list
);
3763 atomic_set(&ctx
->refcount
, 1);
3766 static struct perf_event_context
*
3767 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3769 struct perf_event_context
*ctx
;
3771 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3775 __perf_event_init_context(ctx
);
3778 get_task_struct(task
);
3785 static struct task_struct
*
3786 find_lively_task_by_vpid(pid_t vpid
)
3788 struct task_struct
*task
;
3794 task
= find_task_by_vpid(vpid
);
3796 get_task_struct(task
);
3800 return ERR_PTR(-ESRCH
);
3806 * Returns a matching context with refcount and pincount.
3808 static struct perf_event_context
*
3809 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3810 struct perf_event
*event
)
3812 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3813 struct perf_cpu_context
*cpuctx
;
3814 void *task_ctx_data
= NULL
;
3815 unsigned long flags
;
3817 int cpu
= event
->cpu
;
3820 /* Must be root to operate on a CPU event: */
3821 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3822 return ERR_PTR(-EACCES
);
3824 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3833 ctxn
= pmu
->task_ctx_nr
;
3837 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3838 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3839 if (!task_ctx_data
) {
3846 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3848 clone_ctx
= unclone_ctx(ctx
);
3851 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3852 ctx
->task_ctx_data
= task_ctx_data
;
3853 task_ctx_data
= NULL
;
3855 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3860 ctx
= alloc_perf_context(pmu
, task
);
3865 if (task_ctx_data
) {
3866 ctx
->task_ctx_data
= task_ctx_data
;
3867 task_ctx_data
= NULL
;
3871 mutex_lock(&task
->perf_event_mutex
);
3873 * If it has already passed perf_event_exit_task().
3874 * we must see PF_EXITING, it takes this mutex too.
3876 if (task
->flags
& PF_EXITING
)
3878 else if (task
->perf_event_ctxp
[ctxn
])
3883 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3885 mutex_unlock(&task
->perf_event_mutex
);
3887 if (unlikely(err
)) {
3896 kfree(task_ctx_data
);
3900 kfree(task_ctx_data
);
3901 return ERR_PTR(err
);
3904 static void perf_event_free_filter(struct perf_event
*event
);
3905 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3907 static void free_event_rcu(struct rcu_head
*head
)
3909 struct perf_event
*event
;
3911 event
= container_of(head
, struct perf_event
, rcu_head
);
3913 put_pid_ns(event
->ns
);
3914 perf_event_free_filter(event
);
3918 static void ring_buffer_attach(struct perf_event
*event
,
3919 struct ring_buffer
*rb
);
3921 static void detach_sb_event(struct perf_event
*event
)
3923 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3925 raw_spin_lock(&pel
->lock
);
3926 list_del_rcu(&event
->sb_list
);
3927 raw_spin_unlock(&pel
->lock
);
3930 static bool is_sb_event(struct perf_event
*event
)
3932 struct perf_event_attr
*attr
= &event
->attr
;
3937 if (event
->attach_state
& PERF_ATTACH_TASK
)
3940 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3941 attr
->comm
|| attr
->comm_exec
||
3943 attr
->context_switch
)
3948 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3950 if (is_sb_event(event
))
3951 detach_sb_event(event
);
3954 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3959 if (is_cgroup_event(event
))
3960 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3963 #ifdef CONFIG_NO_HZ_FULL
3964 static DEFINE_SPINLOCK(nr_freq_lock
);
3967 static void unaccount_freq_event_nohz(void)
3969 #ifdef CONFIG_NO_HZ_FULL
3970 spin_lock(&nr_freq_lock
);
3971 if (atomic_dec_and_test(&nr_freq_events
))
3972 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3973 spin_unlock(&nr_freq_lock
);
3977 static void unaccount_freq_event(void)
3979 if (tick_nohz_full_enabled())
3980 unaccount_freq_event_nohz();
3982 atomic_dec(&nr_freq_events
);
3985 static void unaccount_event(struct perf_event
*event
)
3992 if (event
->attach_state
& PERF_ATTACH_TASK
)
3994 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3995 atomic_dec(&nr_mmap_events
);
3996 if (event
->attr
.comm
)
3997 atomic_dec(&nr_comm_events
);
3998 if (event
->attr
.namespaces
)
3999 atomic_dec(&nr_namespaces_events
);
4000 if (event
->attr
.task
)
4001 atomic_dec(&nr_task_events
);
4002 if (event
->attr
.freq
)
4003 unaccount_freq_event();
4004 if (event
->attr
.context_switch
) {
4006 atomic_dec(&nr_switch_events
);
4008 if (is_cgroup_event(event
))
4010 if (has_branch_stack(event
))
4014 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4015 schedule_delayed_work(&perf_sched_work
, HZ
);
4018 unaccount_event_cpu(event
, event
->cpu
);
4020 unaccount_pmu_sb_event(event
);
4023 static void perf_sched_delayed(struct work_struct
*work
)
4025 mutex_lock(&perf_sched_mutex
);
4026 if (atomic_dec_and_test(&perf_sched_count
))
4027 static_branch_disable(&perf_sched_events
);
4028 mutex_unlock(&perf_sched_mutex
);
4032 * The following implement mutual exclusion of events on "exclusive" pmus
4033 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4034 * at a time, so we disallow creating events that might conflict, namely:
4036 * 1) cpu-wide events in the presence of per-task events,
4037 * 2) per-task events in the presence of cpu-wide events,
4038 * 3) two matching events on the same context.
4040 * The former two cases are handled in the allocation path (perf_event_alloc(),
4041 * _free_event()), the latter -- before the first perf_install_in_context().
4043 static int exclusive_event_init(struct perf_event
*event
)
4045 struct pmu
*pmu
= event
->pmu
;
4047 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4051 * Prevent co-existence of per-task and cpu-wide events on the
4052 * same exclusive pmu.
4054 * Negative pmu::exclusive_cnt means there are cpu-wide
4055 * events on this "exclusive" pmu, positive means there are
4058 * Since this is called in perf_event_alloc() path, event::ctx
4059 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4060 * to mean "per-task event", because unlike other attach states it
4061 * never gets cleared.
4063 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4064 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4067 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4074 static void exclusive_event_destroy(struct perf_event
*event
)
4076 struct pmu
*pmu
= event
->pmu
;
4078 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4081 /* see comment in exclusive_event_init() */
4082 if (event
->attach_state
& PERF_ATTACH_TASK
)
4083 atomic_dec(&pmu
->exclusive_cnt
);
4085 atomic_inc(&pmu
->exclusive_cnt
);
4088 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4090 if ((e1
->pmu
== e2
->pmu
) &&
4091 (e1
->cpu
== e2
->cpu
||
4098 /* Called under the same ctx::mutex as perf_install_in_context() */
4099 static bool exclusive_event_installable(struct perf_event
*event
,
4100 struct perf_event_context
*ctx
)
4102 struct perf_event
*iter_event
;
4103 struct pmu
*pmu
= event
->pmu
;
4105 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4108 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4109 if (exclusive_event_match(iter_event
, event
))
4116 static void perf_addr_filters_splice(struct perf_event
*event
,
4117 struct list_head
*head
);
4119 static void _free_event(struct perf_event
*event
)
4121 irq_work_sync(&event
->pending
);
4123 unaccount_event(event
);
4127 * Can happen when we close an event with re-directed output.
4129 * Since we have a 0 refcount, perf_mmap_close() will skip
4130 * over us; possibly making our ring_buffer_put() the last.
4132 mutex_lock(&event
->mmap_mutex
);
4133 ring_buffer_attach(event
, NULL
);
4134 mutex_unlock(&event
->mmap_mutex
);
4137 if (is_cgroup_event(event
))
4138 perf_detach_cgroup(event
);
4140 if (!event
->parent
) {
4141 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4142 put_callchain_buffers();
4145 perf_event_free_bpf_prog(event
);
4146 perf_addr_filters_splice(event
, NULL
);
4147 kfree(event
->addr_filters_offs
);
4150 event
->destroy(event
);
4153 put_ctx(event
->ctx
);
4155 if (event
->hw
.target
)
4156 put_task_struct(event
->hw
.target
);
4158 exclusive_event_destroy(event
);
4159 module_put(event
->pmu
->module
);
4161 call_rcu(&event
->rcu_head
, free_event_rcu
);
4165 * Used to free events which have a known refcount of 1, such as in error paths
4166 * where the event isn't exposed yet and inherited events.
4168 static void free_event(struct perf_event
*event
)
4170 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4171 "unexpected event refcount: %ld; ptr=%p\n",
4172 atomic_long_read(&event
->refcount
), event
)) {
4173 /* leak to avoid use-after-free */
4181 * Remove user event from the owner task.
4183 static void perf_remove_from_owner(struct perf_event
*event
)
4185 struct task_struct
*owner
;
4189 * Matches the smp_store_release() in perf_event_exit_task(). If we
4190 * observe !owner it means the list deletion is complete and we can
4191 * indeed free this event, otherwise we need to serialize on
4192 * owner->perf_event_mutex.
4194 owner
= READ_ONCE(event
->owner
);
4197 * Since delayed_put_task_struct() also drops the last
4198 * task reference we can safely take a new reference
4199 * while holding the rcu_read_lock().
4201 get_task_struct(owner
);
4207 * If we're here through perf_event_exit_task() we're already
4208 * holding ctx->mutex which would be an inversion wrt. the
4209 * normal lock order.
4211 * However we can safely take this lock because its the child
4214 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4217 * We have to re-check the event->owner field, if it is cleared
4218 * we raced with perf_event_exit_task(), acquiring the mutex
4219 * ensured they're done, and we can proceed with freeing the
4223 list_del_init(&event
->owner_entry
);
4224 smp_store_release(&event
->owner
, NULL
);
4226 mutex_unlock(&owner
->perf_event_mutex
);
4227 put_task_struct(owner
);
4231 static void put_event(struct perf_event
*event
)
4233 if (!atomic_long_dec_and_test(&event
->refcount
))
4240 * Kill an event dead; while event:refcount will preserve the event
4241 * object, it will not preserve its functionality. Once the last 'user'
4242 * gives up the object, we'll destroy the thing.
4244 int perf_event_release_kernel(struct perf_event
*event
)
4246 struct perf_event_context
*ctx
= event
->ctx
;
4247 struct perf_event
*child
, *tmp
;
4248 LIST_HEAD(free_list
);
4251 * If we got here through err_file: fput(event_file); we will not have
4252 * attached to a context yet.
4255 WARN_ON_ONCE(event
->attach_state
&
4256 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4260 if (!is_kernel_event(event
))
4261 perf_remove_from_owner(event
);
4263 ctx
= perf_event_ctx_lock(event
);
4264 WARN_ON_ONCE(ctx
->parent_ctx
);
4265 perf_remove_from_context(event
, DETACH_GROUP
);
4267 raw_spin_lock_irq(&ctx
->lock
);
4269 * Mark this event as STATE_DEAD, there is no external reference to it
4272 * Anybody acquiring event->child_mutex after the below loop _must_
4273 * also see this, most importantly inherit_event() which will avoid
4274 * placing more children on the list.
4276 * Thus this guarantees that we will in fact observe and kill _ALL_
4279 event
->state
= PERF_EVENT_STATE_DEAD
;
4280 raw_spin_unlock_irq(&ctx
->lock
);
4282 perf_event_ctx_unlock(event
, ctx
);
4285 mutex_lock(&event
->child_mutex
);
4286 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4289 * Cannot change, child events are not migrated, see the
4290 * comment with perf_event_ctx_lock_nested().
4292 ctx
= READ_ONCE(child
->ctx
);
4294 * Since child_mutex nests inside ctx::mutex, we must jump
4295 * through hoops. We start by grabbing a reference on the ctx.
4297 * Since the event cannot get freed while we hold the
4298 * child_mutex, the context must also exist and have a !0
4304 * Now that we have a ctx ref, we can drop child_mutex, and
4305 * acquire ctx::mutex without fear of it going away. Then we
4306 * can re-acquire child_mutex.
4308 mutex_unlock(&event
->child_mutex
);
4309 mutex_lock(&ctx
->mutex
);
4310 mutex_lock(&event
->child_mutex
);
4313 * Now that we hold ctx::mutex and child_mutex, revalidate our
4314 * state, if child is still the first entry, it didn't get freed
4315 * and we can continue doing so.
4317 tmp
= list_first_entry_or_null(&event
->child_list
,
4318 struct perf_event
, child_list
);
4320 perf_remove_from_context(child
, DETACH_GROUP
);
4321 list_move(&child
->child_list
, &free_list
);
4323 * This matches the refcount bump in inherit_event();
4324 * this can't be the last reference.
4329 mutex_unlock(&event
->child_mutex
);
4330 mutex_unlock(&ctx
->mutex
);
4334 mutex_unlock(&event
->child_mutex
);
4336 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4337 list_del(&child
->child_list
);
4342 put_event(event
); /* Must be the 'last' reference */
4345 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4348 * Called when the last reference to the file is gone.
4350 static int perf_release(struct inode
*inode
, struct file
*file
)
4352 perf_event_release_kernel(file
->private_data
);
4356 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4358 struct perf_event
*child
;
4364 mutex_lock(&event
->child_mutex
);
4366 (void)perf_event_read(event
, false);
4367 total
+= perf_event_count(event
);
4369 *enabled
+= event
->total_time_enabled
+
4370 atomic64_read(&event
->child_total_time_enabled
);
4371 *running
+= event
->total_time_running
+
4372 atomic64_read(&event
->child_total_time_running
);
4374 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4375 (void)perf_event_read(child
, false);
4376 total
+= perf_event_count(child
);
4377 *enabled
+= child
->total_time_enabled
;
4378 *running
+= child
->total_time_running
;
4380 mutex_unlock(&event
->child_mutex
);
4385 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4387 struct perf_event_context
*ctx
;
4390 ctx
= perf_event_ctx_lock(event
);
4391 count
= __perf_event_read_value(event
, enabled
, running
);
4392 perf_event_ctx_unlock(event
, ctx
);
4396 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4398 static int __perf_read_group_add(struct perf_event
*leader
,
4399 u64 read_format
, u64
*values
)
4401 struct perf_event_context
*ctx
= leader
->ctx
;
4402 struct perf_event
*sub
;
4403 unsigned long flags
;
4404 int n
= 1; /* skip @nr */
4407 ret
= perf_event_read(leader
, true);
4411 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4414 * Since we co-schedule groups, {enabled,running} times of siblings
4415 * will be identical to those of the leader, so we only publish one
4418 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4419 values
[n
++] += leader
->total_time_enabled
+
4420 atomic64_read(&leader
->child_total_time_enabled
);
4423 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4424 values
[n
++] += leader
->total_time_running
+
4425 atomic64_read(&leader
->child_total_time_running
);
4429 * Write {count,id} tuples for every sibling.
4431 values
[n
++] += perf_event_count(leader
);
4432 if (read_format
& PERF_FORMAT_ID
)
4433 values
[n
++] = primary_event_id(leader
);
4435 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4436 values
[n
++] += perf_event_count(sub
);
4437 if (read_format
& PERF_FORMAT_ID
)
4438 values
[n
++] = primary_event_id(sub
);
4441 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4445 static int perf_read_group(struct perf_event
*event
,
4446 u64 read_format
, char __user
*buf
)
4448 struct perf_event
*leader
= event
->group_leader
, *child
;
4449 struct perf_event_context
*ctx
= leader
->ctx
;
4453 lockdep_assert_held(&ctx
->mutex
);
4455 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4459 values
[0] = 1 + leader
->nr_siblings
;
4462 * By locking the child_mutex of the leader we effectively
4463 * lock the child list of all siblings.. XXX explain how.
4465 mutex_lock(&leader
->child_mutex
);
4467 ret
= __perf_read_group_add(leader
, read_format
, values
);
4471 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4472 ret
= __perf_read_group_add(child
, read_format
, values
);
4477 mutex_unlock(&leader
->child_mutex
);
4479 ret
= event
->read_size
;
4480 if (copy_to_user(buf
, values
, event
->read_size
))
4485 mutex_unlock(&leader
->child_mutex
);
4491 static int perf_read_one(struct perf_event
*event
,
4492 u64 read_format
, char __user
*buf
)
4494 u64 enabled
, running
;
4498 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4499 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4500 values
[n
++] = enabled
;
4501 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4502 values
[n
++] = running
;
4503 if (read_format
& PERF_FORMAT_ID
)
4504 values
[n
++] = primary_event_id(event
);
4506 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4509 return n
* sizeof(u64
);
4512 static bool is_event_hup(struct perf_event
*event
)
4516 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4519 mutex_lock(&event
->child_mutex
);
4520 no_children
= list_empty(&event
->child_list
);
4521 mutex_unlock(&event
->child_mutex
);
4526 * Read the performance event - simple non blocking version for now
4529 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4531 u64 read_format
= event
->attr
.read_format
;
4535 * Return end-of-file for a read on a event that is in
4536 * error state (i.e. because it was pinned but it couldn't be
4537 * scheduled on to the CPU at some point).
4539 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4542 if (count
< event
->read_size
)
4545 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4546 if (read_format
& PERF_FORMAT_GROUP
)
4547 ret
= perf_read_group(event
, read_format
, buf
);
4549 ret
= perf_read_one(event
, read_format
, buf
);
4555 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4557 struct perf_event
*event
= file
->private_data
;
4558 struct perf_event_context
*ctx
;
4561 ctx
= perf_event_ctx_lock(event
);
4562 ret
= __perf_read(event
, buf
, count
);
4563 perf_event_ctx_unlock(event
, ctx
);
4568 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4570 struct perf_event
*event
= file
->private_data
;
4571 struct ring_buffer
*rb
;
4572 unsigned int events
= POLLHUP
;
4574 poll_wait(file
, &event
->waitq
, wait
);
4576 if (is_event_hup(event
))
4580 * Pin the event->rb by taking event->mmap_mutex; otherwise
4581 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4583 mutex_lock(&event
->mmap_mutex
);
4586 events
= atomic_xchg(&rb
->poll
, 0);
4587 mutex_unlock(&event
->mmap_mutex
);
4591 static void _perf_event_reset(struct perf_event
*event
)
4593 (void)perf_event_read(event
, false);
4594 local64_set(&event
->count
, 0);
4595 perf_event_update_userpage(event
);
4599 * Holding the top-level event's child_mutex means that any
4600 * descendant process that has inherited this event will block
4601 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4602 * task existence requirements of perf_event_enable/disable.
4604 static void perf_event_for_each_child(struct perf_event
*event
,
4605 void (*func
)(struct perf_event
*))
4607 struct perf_event
*child
;
4609 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4611 mutex_lock(&event
->child_mutex
);
4613 list_for_each_entry(child
, &event
->child_list
, child_list
)
4615 mutex_unlock(&event
->child_mutex
);
4618 static void perf_event_for_each(struct perf_event
*event
,
4619 void (*func
)(struct perf_event
*))
4621 struct perf_event_context
*ctx
= event
->ctx
;
4622 struct perf_event
*sibling
;
4624 lockdep_assert_held(&ctx
->mutex
);
4626 event
= event
->group_leader
;
4628 perf_event_for_each_child(event
, func
);
4629 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4630 perf_event_for_each_child(sibling
, func
);
4633 static void __perf_event_period(struct perf_event
*event
,
4634 struct perf_cpu_context
*cpuctx
,
4635 struct perf_event_context
*ctx
,
4638 u64 value
= *((u64
*)info
);
4641 if (event
->attr
.freq
) {
4642 event
->attr
.sample_freq
= value
;
4644 event
->attr
.sample_period
= value
;
4645 event
->hw
.sample_period
= value
;
4648 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4650 perf_pmu_disable(ctx
->pmu
);
4652 * We could be throttled; unthrottle now to avoid the tick
4653 * trying to unthrottle while we already re-started the event.
4655 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4656 event
->hw
.interrupts
= 0;
4657 perf_log_throttle(event
, 1);
4659 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4662 local64_set(&event
->hw
.period_left
, 0);
4665 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4666 perf_pmu_enable(ctx
->pmu
);
4670 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4674 if (!is_sampling_event(event
))
4677 if (copy_from_user(&value
, arg
, sizeof(value
)))
4683 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4686 event_function_call(event
, __perf_event_period
, &value
);
4691 static const struct file_operations perf_fops
;
4693 static inline int perf_fget_light(int fd
, struct fd
*p
)
4695 struct fd f
= fdget(fd
);
4699 if (f
.file
->f_op
!= &perf_fops
) {
4707 static int perf_event_set_output(struct perf_event
*event
,
4708 struct perf_event
*output_event
);
4709 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4710 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4712 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4714 void (*func
)(struct perf_event
*);
4718 case PERF_EVENT_IOC_ENABLE
:
4719 func
= _perf_event_enable
;
4721 case PERF_EVENT_IOC_DISABLE
:
4722 func
= _perf_event_disable
;
4724 case PERF_EVENT_IOC_RESET
:
4725 func
= _perf_event_reset
;
4728 case PERF_EVENT_IOC_REFRESH
:
4729 return _perf_event_refresh(event
, arg
);
4731 case PERF_EVENT_IOC_PERIOD
:
4732 return perf_event_period(event
, (u64 __user
*)arg
);
4734 case PERF_EVENT_IOC_ID
:
4736 u64 id
= primary_event_id(event
);
4738 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4743 case PERF_EVENT_IOC_SET_OUTPUT
:
4747 struct perf_event
*output_event
;
4749 ret
= perf_fget_light(arg
, &output
);
4752 output_event
= output
.file
->private_data
;
4753 ret
= perf_event_set_output(event
, output_event
);
4756 ret
= perf_event_set_output(event
, NULL
);
4761 case PERF_EVENT_IOC_SET_FILTER
:
4762 return perf_event_set_filter(event
, (void __user
*)arg
);
4764 case PERF_EVENT_IOC_SET_BPF
:
4765 return perf_event_set_bpf_prog(event
, arg
);
4767 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4768 struct ring_buffer
*rb
;
4771 rb
= rcu_dereference(event
->rb
);
4772 if (!rb
|| !rb
->nr_pages
) {
4776 rb_toggle_paused(rb
, !!arg
);
4784 if (flags
& PERF_IOC_FLAG_GROUP
)
4785 perf_event_for_each(event
, func
);
4787 perf_event_for_each_child(event
, func
);
4792 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4794 struct perf_event
*event
= file
->private_data
;
4795 struct perf_event_context
*ctx
;
4798 ctx
= perf_event_ctx_lock(event
);
4799 ret
= _perf_ioctl(event
, cmd
, arg
);
4800 perf_event_ctx_unlock(event
, ctx
);
4805 #ifdef CONFIG_COMPAT
4806 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4809 switch (_IOC_NR(cmd
)) {
4810 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4811 case _IOC_NR(PERF_EVENT_IOC_ID
):
4812 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4813 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4814 cmd
&= ~IOCSIZE_MASK
;
4815 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4819 return perf_ioctl(file
, cmd
, arg
);
4822 # define perf_compat_ioctl NULL
4825 int perf_event_task_enable(void)
4827 struct perf_event_context
*ctx
;
4828 struct perf_event
*event
;
4830 mutex_lock(¤t
->perf_event_mutex
);
4831 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4832 ctx
= perf_event_ctx_lock(event
);
4833 perf_event_for_each_child(event
, _perf_event_enable
);
4834 perf_event_ctx_unlock(event
, ctx
);
4836 mutex_unlock(¤t
->perf_event_mutex
);
4841 int perf_event_task_disable(void)
4843 struct perf_event_context
*ctx
;
4844 struct perf_event
*event
;
4846 mutex_lock(¤t
->perf_event_mutex
);
4847 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4848 ctx
= perf_event_ctx_lock(event
);
4849 perf_event_for_each_child(event
, _perf_event_disable
);
4850 perf_event_ctx_unlock(event
, ctx
);
4852 mutex_unlock(¤t
->perf_event_mutex
);
4857 static int perf_event_index(struct perf_event
*event
)
4859 if (event
->hw
.state
& PERF_HES_STOPPED
)
4862 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4865 return event
->pmu
->event_idx(event
);
4868 static void calc_timer_values(struct perf_event
*event
,
4875 *now
= perf_clock();
4876 ctx_time
= event
->shadow_ctx_time
+ *now
;
4877 __perf_update_times(event
, ctx_time
, enabled
, running
);
4880 static void perf_event_init_userpage(struct perf_event
*event
)
4882 struct perf_event_mmap_page
*userpg
;
4883 struct ring_buffer
*rb
;
4886 rb
= rcu_dereference(event
->rb
);
4890 userpg
= rb
->user_page
;
4892 /* Allow new userspace to detect that bit 0 is deprecated */
4893 userpg
->cap_bit0_is_deprecated
= 1;
4894 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4895 userpg
->data_offset
= PAGE_SIZE
;
4896 userpg
->data_size
= perf_data_size(rb
);
4902 void __weak
arch_perf_update_userpage(
4903 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4908 * Callers need to ensure there can be no nesting of this function, otherwise
4909 * the seqlock logic goes bad. We can not serialize this because the arch
4910 * code calls this from NMI context.
4912 void perf_event_update_userpage(struct perf_event
*event
)
4914 struct perf_event_mmap_page
*userpg
;
4915 struct ring_buffer
*rb
;
4916 u64 enabled
, running
, now
;
4919 rb
= rcu_dereference(event
->rb
);
4924 * compute total_time_enabled, total_time_running
4925 * based on snapshot values taken when the event
4926 * was last scheduled in.
4928 * we cannot simply called update_context_time()
4929 * because of locking issue as we can be called in
4932 calc_timer_values(event
, &now
, &enabled
, &running
);
4934 userpg
= rb
->user_page
;
4936 * Disable preemption so as to not let the corresponding user-space
4937 * spin too long if we get preempted.
4942 userpg
->index
= perf_event_index(event
);
4943 userpg
->offset
= perf_event_count(event
);
4945 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4947 userpg
->time_enabled
= enabled
+
4948 atomic64_read(&event
->child_total_time_enabled
);
4950 userpg
->time_running
= running
+
4951 atomic64_read(&event
->child_total_time_running
);
4953 arch_perf_update_userpage(event
, userpg
, now
);
4962 static int perf_mmap_fault(struct vm_fault
*vmf
)
4964 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4965 struct ring_buffer
*rb
;
4966 int ret
= VM_FAULT_SIGBUS
;
4968 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4969 if (vmf
->pgoff
== 0)
4975 rb
= rcu_dereference(event
->rb
);
4979 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4982 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4986 get_page(vmf
->page
);
4987 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4988 vmf
->page
->index
= vmf
->pgoff
;
4997 static void ring_buffer_attach(struct perf_event
*event
,
4998 struct ring_buffer
*rb
)
5000 struct ring_buffer
*old_rb
= NULL
;
5001 unsigned long flags
;
5005 * Should be impossible, we set this when removing
5006 * event->rb_entry and wait/clear when adding event->rb_entry.
5008 WARN_ON_ONCE(event
->rcu_pending
);
5011 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5012 list_del_rcu(&event
->rb_entry
);
5013 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5015 event
->rcu_batches
= get_state_synchronize_rcu();
5016 event
->rcu_pending
= 1;
5020 if (event
->rcu_pending
) {
5021 cond_synchronize_rcu(event
->rcu_batches
);
5022 event
->rcu_pending
= 0;
5025 spin_lock_irqsave(&rb
->event_lock
, flags
);
5026 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5027 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5031 * Avoid racing with perf_mmap_close(AUX): stop the event
5032 * before swizzling the event::rb pointer; if it's getting
5033 * unmapped, its aux_mmap_count will be 0 and it won't
5034 * restart. See the comment in __perf_pmu_output_stop().
5036 * Data will inevitably be lost when set_output is done in
5037 * mid-air, but then again, whoever does it like this is
5038 * not in for the data anyway.
5041 perf_event_stop(event
, 0);
5043 rcu_assign_pointer(event
->rb
, rb
);
5046 ring_buffer_put(old_rb
);
5048 * Since we detached before setting the new rb, so that we
5049 * could attach the new rb, we could have missed a wakeup.
5052 wake_up_all(&event
->waitq
);
5056 static void ring_buffer_wakeup(struct perf_event
*event
)
5058 struct ring_buffer
*rb
;
5061 rb
= rcu_dereference(event
->rb
);
5063 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5064 wake_up_all(&event
->waitq
);
5069 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5071 struct ring_buffer
*rb
;
5074 rb
= rcu_dereference(event
->rb
);
5076 if (!atomic_inc_not_zero(&rb
->refcount
))
5084 void ring_buffer_put(struct ring_buffer
*rb
)
5086 if (!atomic_dec_and_test(&rb
->refcount
))
5089 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5091 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5094 static void perf_mmap_open(struct vm_area_struct
*vma
)
5096 struct perf_event
*event
= vma
->vm_file
->private_data
;
5098 atomic_inc(&event
->mmap_count
);
5099 atomic_inc(&event
->rb
->mmap_count
);
5102 atomic_inc(&event
->rb
->aux_mmap_count
);
5104 if (event
->pmu
->event_mapped
)
5105 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5108 static void perf_pmu_output_stop(struct perf_event
*event
);
5111 * A buffer can be mmap()ed multiple times; either directly through the same
5112 * event, or through other events by use of perf_event_set_output().
5114 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5115 * the buffer here, where we still have a VM context. This means we need
5116 * to detach all events redirecting to us.
5118 static void perf_mmap_close(struct vm_area_struct
*vma
)
5120 struct perf_event
*event
= vma
->vm_file
->private_data
;
5122 struct ring_buffer
*rb
= ring_buffer_get(event
);
5123 struct user_struct
*mmap_user
= rb
->mmap_user
;
5124 int mmap_locked
= rb
->mmap_locked
;
5125 unsigned long size
= perf_data_size(rb
);
5127 if (event
->pmu
->event_unmapped
)
5128 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5131 * rb->aux_mmap_count will always drop before rb->mmap_count and
5132 * event->mmap_count, so it is ok to use event->mmap_mutex to
5133 * serialize with perf_mmap here.
5135 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5136 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5138 * Stop all AUX events that are writing to this buffer,
5139 * so that we can free its AUX pages and corresponding PMU
5140 * data. Note that after rb::aux_mmap_count dropped to zero,
5141 * they won't start any more (see perf_aux_output_begin()).
5143 perf_pmu_output_stop(event
);
5145 /* now it's safe to free the pages */
5146 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5147 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5149 /* this has to be the last one */
5151 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5153 mutex_unlock(&event
->mmap_mutex
);
5156 atomic_dec(&rb
->mmap_count
);
5158 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5161 ring_buffer_attach(event
, NULL
);
5162 mutex_unlock(&event
->mmap_mutex
);
5164 /* If there's still other mmap()s of this buffer, we're done. */
5165 if (atomic_read(&rb
->mmap_count
))
5169 * No other mmap()s, detach from all other events that might redirect
5170 * into the now unreachable buffer. Somewhat complicated by the
5171 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5175 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5176 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5178 * This event is en-route to free_event() which will
5179 * detach it and remove it from the list.
5185 mutex_lock(&event
->mmap_mutex
);
5187 * Check we didn't race with perf_event_set_output() which can
5188 * swizzle the rb from under us while we were waiting to
5189 * acquire mmap_mutex.
5191 * If we find a different rb; ignore this event, a next
5192 * iteration will no longer find it on the list. We have to
5193 * still restart the iteration to make sure we're not now
5194 * iterating the wrong list.
5196 if (event
->rb
== rb
)
5197 ring_buffer_attach(event
, NULL
);
5199 mutex_unlock(&event
->mmap_mutex
);
5203 * Restart the iteration; either we're on the wrong list or
5204 * destroyed its integrity by doing a deletion.
5211 * It could be there's still a few 0-ref events on the list; they'll
5212 * get cleaned up by free_event() -- they'll also still have their
5213 * ref on the rb and will free it whenever they are done with it.
5215 * Aside from that, this buffer is 'fully' detached and unmapped,
5216 * undo the VM accounting.
5219 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5220 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5221 free_uid(mmap_user
);
5224 ring_buffer_put(rb
); /* could be last */
5227 static const struct vm_operations_struct perf_mmap_vmops
= {
5228 .open
= perf_mmap_open
,
5229 .close
= perf_mmap_close
, /* non mergable */
5230 .fault
= perf_mmap_fault
,
5231 .page_mkwrite
= perf_mmap_fault
,
5234 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5236 struct perf_event
*event
= file
->private_data
;
5237 unsigned long user_locked
, user_lock_limit
;
5238 struct user_struct
*user
= current_user();
5239 unsigned long locked
, lock_limit
;
5240 struct ring_buffer
*rb
= NULL
;
5241 unsigned long vma_size
;
5242 unsigned long nr_pages
;
5243 long user_extra
= 0, extra
= 0;
5244 int ret
= 0, flags
= 0;
5247 * Don't allow mmap() of inherited per-task counters. This would
5248 * create a performance issue due to all children writing to the
5251 if (event
->cpu
== -1 && event
->attr
.inherit
)
5254 if (!(vma
->vm_flags
& VM_SHARED
))
5257 vma_size
= vma
->vm_end
- vma
->vm_start
;
5259 if (vma
->vm_pgoff
== 0) {
5260 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5263 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5264 * mapped, all subsequent mappings should have the same size
5265 * and offset. Must be above the normal perf buffer.
5267 u64 aux_offset
, aux_size
;
5272 nr_pages
= vma_size
/ PAGE_SIZE
;
5274 mutex_lock(&event
->mmap_mutex
);
5281 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5282 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5284 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5287 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5290 /* already mapped with a different offset */
5291 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5294 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5297 /* already mapped with a different size */
5298 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5301 if (!is_power_of_2(nr_pages
))
5304 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5307 if (rb_has_aux(rb
)) {
5308 atomic_inc(&rb
->aux_mmap_count
);
5313 atomic_set(&rb
->aux_mmap_count
, 1);
5314 user_extra
= nr_pages
;
5320 * If we have rb pages ensure they're a power-of-two number, so we
5321 * can do bitmasks instead of modulo.
5323 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5326 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5329 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5331 mutex_lock(&event
->mmap_mutex
);
5333 if (event
->rb
->nr_pages
!= nr_pages
) {
5338 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5340 * Raced against perf_mmap_close() through
5341 * perf_event_set_output(). Try again, hope for better
5344 mutex_unlock(&event
->mmap_mutex
);
5351 user_extra
= nr_pages
+ 1;
5354 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5357 * Increase the limit linearly with more CPUs:
5359 user_lock_limit
*= num_online_cpus();
5361 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5363 if (user_locked
> user_lock_limit
)
5364 extra
= user_locked
- user_lock_limit
;
5366 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5367 lock_limit
>>= PAGE_SHIFT
;
5368 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5370 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5371 !capable(CAP_IPC_LOCK
)) {
5376 WARN_ON(!rb
&& event
->rb
);
5378 if (vma
->vm_flags
& VM_WRITE
)
5379 flags
|= RING_BUFFER_WRITABLE
;
5382 rb
= rb_alloc(nr_pages
,
5383 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5391 atomic_set(&rb
->mmap_count
, 1);
5392 rb
->mmap_user
= get_current_user();
5393 rb
->mmap_locked
= extra
;
5395 ring_buffer_attach(event
, rb
);
5397 perf_event_init_userpage(event
);
5398 perf_event_update_userpage(event
);
5400 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5401 event
->attr
.aux_watermark
, flags
);
5403 rb
->aux_mmap_locked
= extra
;
5408 atomic_long_add(user_extra
, &user
->locked_vm
);
5409 vma
->vm_mm
->pinned_vm
+= extra
;
5411 atomic_inc(&event
->mmap_count
);
5413 atomic_dec(&rb
->mmap_count
);
5416 mutex_unlock(&event
->mmap_mutex
);
5419 * Since pinned accounting is per vm we cannot allow fork() to copy our
5422 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5423 vma
->vm_ops
= &perf_mmap_vmops
;
5425 if (event
->pmu
->event_mapped
)
5426 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5431 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5433 struct inode
*inode
= file_inode(filp
);
5434 struct perf_event
*event
= filp
->private_data
;
5438 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5439 inode_unlock(inode
);
5447 static const struct file_operations perf_fops
= {
5448 .llseek
= no_llseek
,
5449 .release
= perf_release
,
5452 .unlocked_ioctl
= perf_ioctl
,
5453 .compat_ioctl
= perf_compat_ioctl
,
5455 .fasync
= perf_fasync
,
5461 * If there's data, ensure we set the poll() state and publish everything
5462 * to user-space before waking everybody up.
5465 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5467 /* only the parent has fasync state */
5469 event
= event
->parent
;
5470 return &event
->fasync
;
5473 void perf_event_wakeup(struct perf_event
*event
)
5475 ring_buffer_wakeup(event
);
5477 if (event
->pending_kill
) {
5478 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5479 event
->pending_kill
= 0;
5483 static void perf_pending_event(struct irq_work
*entry
)
5485 struct perf_event
*event
= container_of(entry
,
5486 struct perf_event
, pending
);
5489 rctx
= perf_swevent_get_recursion_context();
5491 * If we 'fail' here, that's OK, it means recursion is already disabled
5492 * and we won't recurse 'further'.
5495 if (event
->pending_disable
) {
5496 event
->pending_disable
= 0;
5497 perf_event_disable_local(event
);
5500 if (event
->pending_wakeup
) {
5501 event
->pending_wakeup
= 0;
5502 perf_event_wakeup(event
);
5506 perf_swevent_put_recursion_context(rctx
);
5510 * We assume there is only KVM supporting the callbacks.
5511 * Later on, we might change it to a list if there is
5512 * another virtualization implementation supporting the callbacks.
5514 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5516 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5518 perf_guest_cbs
= cbs
;
5521 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5523 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5525 perf_guest_cbs
= NULL
;
5528 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5531 perf_output_sample_regs(struct perf_output_handle
*handle
,
5532 struct pt_regs
*regs
, u64 mask
)
5535 DECLARE_BITMAP(_mask
, 64);
5537 bitmap_from_u64(_mask
, mask
);
5538 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5541 val
= perf_reg_value(regs
, bit
);
5542 perf_output_put(handle
, val
);
5546 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5547 struct pt_regs
*regs
,
5548 struct pt_regs
*regs_user_copy
)
5550 if (user_mode(regs
)) {
5551 regs_user
->abi
= perf_reg_abi(current
);
5552 regs_user
->regs
= regs
;
5553 } else if (current
->mm
) {
5554 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5556 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5557 regs_user
->regs
= NULL
;
5561 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5562 struct pt_regs
*regs
)
5564 regs_intr
->regs
= regs
;
5565 regs_intr
->abi
= perf_reg_abi(current
);
5570 * Get remaining task size from user stack pointer.
5572 * It'd be better to take stack vma map and limit this more
5573 * precisly, but there's no way to get it safely under interrupt,
5574 * so using TASK_SIZE as limit.
5576 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5578 unsigned long addr
= perf_user_stack_pointer(regs
);
5580 if (!addr
|| addr
>= TASK_SIZE
)
5583 return TASK_SIZE
- addr
;
5587 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5588 struct pt_regs
*regs
)
5592 /* No regs, no stack pointer, no dump. */
5597 * Check if we fit in with the requested stack size into the:
5599 * If we don't, we limit the size to the TASK_SIZE.
5601 * - remaining sample size
5602 * If we don't, we customize the stack size to
5603 * fit in to the remaining sample size.
5606 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5607 stack_size
= min(stack_size
, (u16
) task_size
);
5609 /* Current header size plus static size and dynamic size. */
5610 header_size
+= 2 * sizeof(u64
);
5612 /* Do we fit in with the current stack dump size? */
5613 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5615 * If we overflow the maximum size for the sample,
5616 * we customize the stack dump size to fit in.
5618 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5619 stack_size
= round_up(stack_size
, sizeof(u64
));
5626 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5627 struct pt_regs
*regs
)
5629 /* Case of a kernel thread, nothing to dump */
5632 perf_output_put(handle
, size
);
5641 * - the size requested by user or the best one we can fit
5642 * in to the sample max size
5644 * - user stack dump data
5646 * - the actual dumped size
5650 perf_output_put(handle
, dump_size
);
5653 sp
= perf_user_stack_pointer(regs
);
5654 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5655 dyn_size
= dump_size
- rem
;
5657 perf_output_skip(handle
, rem
);
5660 perf_output_put(handle
, dyn_size
);
5664 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5665 struct perf_sample_data
*data
,
5666 struct perf_event
*event
)
5668 u64 sample_type
= event
->attr
.sample_type
;
5670 data
->type
= sample_type
;
5671 header
->size
+= event
->id_header_size
;
5673 if (sample_type
& PERF_SAMPLE_TID
) {
5674 /* namespace issues */
5675 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5676 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5679 if (sample_type
& PERF_SAMPLE_TIME
)
5680 data
->time
= perf_event_clock(event
);
5682 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5683 data
->id
= primary_event_id(event
);
5685 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5686 data
->stream_id
= event
->id
;
5688 if (sample_type
& PERF_SAMPLE_CPU
) {
5689 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5690 data
->cpu_entry
.reserved
= 0;
5694 void perf_event_header__init_id(struct perf_event_header
*header
,
5695 struct perf_sample_data
*data
,
5696 struct perf_event
*event
)
5698 if (event
->attr
.sample_id_all
)
5699 __perf_event_header__init_id(header
, data
, event
);
5702 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5703 struct perf_sample_data
*data
)
5705 u64 sample_type
= data
->type
;
5707 if (sample_type
& PERF_SAMPLE_TID
)
5708 perf_output_put(handle
, data
->tid_entry
);
5710 if (sample_type
& PERF_SAMPLE_TIME
)
5711 perf_output_put(handle
, data
->time
);
5713 if (sample_type
& PERF_SAMPLE_ID
)
5714 perf_output_put(handle
, data
->id
);
5716 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5717 perf_output_put(handle
, data
->stream_id
);
5719 if (sample_type
& PERF_SAMPLE_CPU
)
5720 perf_output_put(handle
, data
->cpu_entry
);
5722 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5723 perf_output_put(handle
, data
->id
);
5726 void perf_event__output_id_sample(struct perf_event
*event
,
5727 struct perf_output_handle
*handle
,
5728 struct perf_sample_data
*sample
)
5730 if (event
->attr
.sample_id_all
)
5731 __perf_event__output_id_sample(handle
, sample
);
5734 static void perf_output_read_one(struct perf_output_handle
*handle
,
5735 struct perf_event
*event
,
5736 u64 enabled
, u64 running
)
5738 u64 read_format
= event
->attr
.read_format
;
5742 values
[n
++] = perf_event_count(event
);
5743 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5744 values
[n
++] = enabled
+
5745 atomic64_read(&event
->child_total_time_enabled
);
5747 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5748 values
[n
++] = running
+
5749 atomic64_read(&event
->child_total_time_running
);
5751 if (read_format
& PERF_FORMAT_ID
)
5752 values
[n
++] = primary_event_id(event
);
5754 __output_copy(handle
, values
, n
* sizeof(u64
));
5757 static void perf_output_read_group(struct perf_output_handle
*handle
,
5758 struct perf_event
*event
,
5759 u64 enabled
, u64 running
)
5761 struct perf_event
*leader
= event
->group_leader
, *sub
;
5762 u64 read_format
= event
->attr
.read_format
;
5766 values
[n
++] = 1 + leader
->nr_siblings
;
5768 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5769 values
[n
++] = enabled
;
5771 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5772 values
[n
++] = running
;
5774 if ((leader
!= event
) &&
5775 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
5776 leader
->pmu
->read(leader
);
5778 values
[n
++] = perf_event_count(leader
);
5779 if (read_format
& PERF_FORMAT_ID
)
5780 values
[n
++] = primary_event_id(leader
);
5782 __output_copy(handle
, values
, n
* sizeof(u64
));
5784 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5787 if ((sub
!= event
) &&
5788 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5789 sub
->pmu
->read(sub
);
5791 values
[n
++] = perf_event_count(sub
);
5792 if (read_format
& PERF_FORMAT_ID
)
5793 values
[n
++] = primary_event_id(sub
);
5795 __output_copy(handle
, values
, n
* sizeof(u64
));
5799 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5800 PERF_FORMAT_TOTAL_TIME_RUNNING)
5803 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5805 * The problem is that its both hard and excessively expensive to iterate the
5806 * child list, not to mention that its impossible to IPI the children running
5807 * on another CPU, from interrupt/NMI context.
5809 static void perf_output_read(struct perf_output_handle
*handle
,
5810 struct perf_event
*event
)
5812 u64 enabled
= 0, running
= 0, now
;
5813 u64 read_format
= event
->attr
.read_format
;
5816 * compute total_time_enabled, total_time_running
5817 * based on snapshot values taken when the event
5818 * was last scheduled in.
5820 * we cannot simply called update_context_time()
5821 * because of locking issue as we are called in
5824 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5825 calc_timer_values(event
, &now
, &enabled
, &running
);
5827 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5828 perf_output_read_group(handle
, event
, enabled
, running
);
5830 perf_output_read_one(handle
, event
, enabled
, running
);
5833 void perf_output_sample(struct perf_output_handle
*handle
,
5834 struct perf_event_header
*header
,
5835 struct perf_sample_data
*data
,
5836 struct perf_event
*event
)
5838 u64 sample_type
= data
->type
;
5840 perf_output_put(handle
, *header
);
5842 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5843 perf_output_put(handle
, data
->id
);
5845 if (sample_type
& PERF_SAMPLE_IP
)
5846 perf_output_put(handle
, data
->ip
);
5848 if (sample_type
& PERF_SAMPLE_TID
)
5849 perf_output_put(handle
, data
->tid_entry
);
5851 if (sample_type
& PERF_SAMPLE_TIME
)
5852 perf_output_put(handle
, data
->time
);
5854 if (sample_type
& PERF_SAMPLE_ADDR
)
5855 perf_output_put(handle
, data
->addr
);
5857 if (sample_type
& PERF_SAMPLE_ID
)
5858 perf_output_put(handle
, data
->id
);
5860 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5861 perf_output_put(handle
, data
->stream_id
);
5863 if (sample_type
& PERF_SAMPLE_CPU
)
5864 perf_output_put(handle
, data
->cpu_entry
);
5866 if (sample_type
& PERF_SAMPLE_PERIOD
)
5867 perf_output_put(handle
, data
->period
);
5869 if (sample_type
& PERF_SAMPLE_READ
)
5870 perf_output_read(handle
, event
);
5872 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5873 if (data
->callchain
) {
5876 if (data
->callchain
)
5877 size
+= data
->callchain
->nr
;
5879 size
*= sizeof(u64
);
5881 __output_copy(handle
, data
->callchain
, size
);
5884 perf_output_put(handle
, nr
);
5888 if (sample_type
& PERF_SAMPLE_RAW
) {
5889 struct perf_raw_record
*raw
= data
->raw
;
5892 struct perf_raw_frag
*frag
= &raw
->frag
;
5894 perf_output_put(handle
, raw
->size
);
5897 __output_custom(handle
, frag
->copy
,
5898 frag
->data
, frag
->size
);
5900 __output_copy(handle
, frag
->data
,
5903 if (perf_raw_frag_last(frag
))
5908 __output_skip(handle
, NULL
, frag
->pad
);
5914 .size
= sizeof(u32
),
5917 perf_output_put(handle
, raw
);
5921 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5922 if (data
->br_stack
) {
5925 size
= data
->br_stack
->nr
5926 * sizeof(struct perf_branch_entry
);
5928 perf_output_put(handle
, data
->br_stack
->nr
);
5929 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5932 * we always store at least the value of nr
5935 perf_output_put(handle
, nr
);
5939 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5940 u64 abi
= data
->regs_user
.abi
;
5943 * If there are no regs to dump, notice it through
5944 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5946 perf_output_put(handle
, abi
);
5949 u64 mask
= event
->attr
.sample_regs_user
;
5950 perf_output_sample_regs(handle
,
5951 data
->regs_user
.regs
,
5956 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5957 perf_output_sample_ustack(handle
,
5958 data
->stack_user_size
,
5959 data
->regs_user
.regs
);
5962 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5963 perf_output_put(handle
, data
->weight
);
5965 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5966 perf_output_put(handle
, data
->data_src
.val
);
5968 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5969 perf_output_put(handle
, data
->txn
);
5971 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5972 u64 abi
= data
->regs_intr
.abi
;
5974 * If there are no regs to dump, notice it through
5975 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5977 perf_output_put(handle
, abi
);
5980 u64 mask
= event
->attr
.sample_regs_intr
;
5982 perf_output_sample_regs(handle
,
5983 data
->regs_intr
.regs
,
5988 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
5989 perf_output_put(handle
, data
->phys_addr
);
5991 if (!event
->attr
.watermark
) {
5992 int wakeup_events
= event
->attr
.wakeup_events
;
5994 if (wakeup_events
) {
5995 struct ring_buffer
*rb
= handle
->rb
;
5996 int events
= local_inc_return(&rb
->events
);
5998 if (events
>= wakeup_events
) {
5999 local_sub(wakeup_events
, &rb
->events
);
6000 local_inc(&rb
->wakeup
);
6006 static u64
perf_virt_to_phys(u64 virt
)
6009 struct page
*p
= NULL
;
6014 if (virt
>= TASK_SIZE
) {
6015 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6016 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6017 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6018 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6021 * Walking the pages tables for user address.
6022 * Interrupts are disabled, so it prevents any tear down
6023 * of the page tables.
6024 * Try IRQ-safe __get_user_pages_fast first.
6025 * If failed, leave phys_addr as 0.
6027 if ((current
->mm
!= NULL
) &&
6028 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6029 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6038 void perf_prepare_sample(struct perf_event_header
*header
,
6039 struct perf_sample_data
*data
,
6040 struct perf_event
*event
,
6041 struct pt_regs
*regs
)
6043 u64 sample_type
= event
->attr
.sample_type
;
6045 header
->type
= PERF_RECORD_SAMPLE
;
6046 header
->size
= sizeof(*header
) + event
->header_size
;
6049 header
->misc
|= perf_misc_flags(regs
);
6051 __perf_event_header__init_id(header
, data
, event
);
6053 if (sample_type
& PERF_SAMPLE_IP
)
6054 data
->ip
= perf_instruction_pointer(regs
);
6056 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6059 data
->callchain
= perf_callchain(event
, regs
);
6061 if (data
->callchain
)
6062 size
+= data
->callchain
->nr
;
6064 header
->size
+= size
* sizeof(u64
);
6067 if (sample_type
& PERF_SAMPLE_RAW
) {
6068 struct perf_raw_record
*raw
= data
->raw
;
6072 struct perf_raw_frag
*frag
= &raw
->frag
;
6077 if (perf_raw_frag_last(frag
))
6082 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6083 raw
->size
= size
- sizeof(u32
);
6084 frag
->pad
= raw
->size
- sum
;
6089 header
->size
+= size
;
6092 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6093 int size
= sizeof(u64
); /* nr */
6094 if (data
->br_stack
) {
6095 size
+= data
->br_stack
->nr
6096 * sizeof(struct perf_branch_entry
);
6098 header
->size
+= size
;
6101 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6102 perf_sample_regs_user(&data
->regs_user
, regs
,
6103 &data
->regs_user_copy
);
6105 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6106 /* regs dump ABI info */
6107 int size
= sizeof(u64
);
6109 if (data
->regs_user
.regs
) {
6110 u64 mask
= event
->attr
.sample_regs_user
;
6111 size
+= hweight64(mask
) * sizeof(u64
);
6114 header
->size
+= size
;
6117 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6119 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6120 * processed as the last one or have additional check added
6121 * in case new sample type is added, because we could eat
6122 * up the rest of the sample size.
6124 u16 stack_size
= event
->attr
.sample_stack_user
;
6125 u16 size
= sizeof(u64
);
6127 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6128 data
->regs_user
.regs
);
6131 * If there is something to dump, add space for the dump
6132 * itself and for the field that tells the dynamic size,
6133 * which is how many have been actually dumped.
6136 size
+= sizeof(u64
) + stack_size
;
6138 data
->stack_user_size
= stack_size
;
6139 header
->size
+= size
;
6142 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6143 /* regs dump ABI info */
6144 int size
= sizeof(u64
);
6146 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6148 if (data
->regs_intr
.regs
) {
6149 u64 mask
= event
->attr
.sample_regs_intr
;
6151 size
+= hweight64(mask
) * sizeof(u64
);
6154 header
->size
+= size
;
6157 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6158 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6161 static void __always_inline
6162 __perf_event_output(struct perf_event
*event
,
6163 struct perf_sample_data
*data
,
6164 struct pt_regs
*regs
,
6165 int (*output_begin
)(struct perf_output_handle
*,
6166 struct perf_event
*,
6169 struct perf_output_handle handle
;
6170 struct perf_event_header header
;
6172 /* protect the callchain buffers */
6175 perf_prepare_sample(&header
, data
, event
, regs
);
6177 if (output_begin(&handle
, event
, header
.size
))
6180 perf_output_sample(&handle
, &header
, data
, event
);
6182 perf_output_end(&handle
);
6189 perf_event_output_forward(struct perf_event
*event
,
6190 struct perf_sample_data
*data
,
6191 struct pt_regs
*regs
)
6193 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6197 perf_event_output_backward(struct perf_event
*event
,
6198 struct perf_sample_data
*data
,
6199 struct pt_regs
*regs
)
6201 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6205 perf_event_output(struct perf_event
*event
,
6206 struct perf_sample_data
*data
,
6207 struct pt_regs
*regs
)
6209 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6216 struct perf_read_event
{
6217 struct perf_event_header header
;
6224 perf_event_read_event(struct perf_event
*event
,
6225 struct task_struct
*task
)
6227 struct perf_output_handle handle
;
6228 struct perf_sample_data sample
;
6229 struct perf_read_event read_event
= {
6231 .type
= PERF_RECORD_READ
,
6233 .size
= sizeof(read_event
) + event
->read_size
,
6235 .pid
= perf_event_pid(event
, task
),
6236 .tid
= perf_event_tid(event
, task
),
6240 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6241 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6245 perf_output_put(&handle
, read_event
);
6246 perf_output_read(&handle
, event
);
6247 perf_event__output_id_sample(event
, &handle
, &sample
);
6249 perf_output_end(&handle
);
6252 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6255 perf_iterate_ctx(struct perf_event_context
*ctx
,
6256 perf_iterate_f output
,
6257 void *data
, bool all
)
6259 struct perf_event
*event
;
6261 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6263 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6265 if (!event_filter_match(event
))
6269 output(event
, data
);
6273 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6275 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6276 struct perf_event
*event
;
6278 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6280 * Skip events that are not fully formed yet; ensure that
6281 * if we observe event->ctx, both event and ctx will be
6282 * complete enough. See perf_install_in_context().
6284 if (!smp_load_acquire(&event
->ctx
))
6287 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6289 if (!event_filter_match(event
))
6291 output(event
, data
);
6296 * Iterate all events that need to receive side-band events.
6298 * For new callers; ensure that account_pmu_sb_event() includes
6299 * your event, otherwise it might not get delivered.
6302 perf_iterate_sb(perf_iterate_f output
, void *data
,
6303 struct perf_event_context
*task_ctx
)
6305 struct perf_event_context
*ctx
;
6312 * If we have task_ctx != NULL we only notify the task context itself.
6313 * The task_ctx is set only for EXIT events before releasing task
6317 perf_iterate_ctx(task_ctx
, output
, data
, false);
6321 perf_iterate_sb_cpu(output
, data
);
6323 for_each_task_context_nr(ctxn
) {
6324 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6326 perf_iterate_ctx(ctx
, output
, data
, false);
6334 * Clear all file-based filters at exec, they'll have to be
6335 * re-instated when/if these objects are mmapped again.
6337 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6339 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6340 struct perf_addr_filter
*filter
;
6341 unsigned int restart
= 0, count
= 0;
6342 unsigned long flags
;
6344 if (!has_addr_filter(event
))
6347 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6348 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6349 if (filter
->inode
) {
6350 event
->addr_filters_offs
[count
] = 0;
6358 event
->addr_filters_gen
++;
6359 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6362 perf_event_stop(event
, 1);
6365 void perf_event_exec(void)
6367 struct perf_event_context
*ctx
;
6371 for_each_task_context_nr(ctxn
) {
6372 ctx
= current
->perf_event_ctxp
[ctxn
];
6376 perf_event_enable_on_exec(ctxn
);
6378 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6384 struct remote_output
{
6385 struct ring_buffer
*rb
;
6389 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6391 struct perf_event
*parent
= event
->parent
;
6392 struct remote_output
*ro
= data
;
6393 struct ring_buffer
*rb
= ro
->rb
;
6394 struct stop_event_data sd
= {
6398 if (!has_aux(event
))
6405 * In case of inheritance, it will be the parent that links to the
6406 * ring-buffer, but it will be the child that's actually using it.
6408 * We are using event::rb to determine if the event should be stopped,
6409 * however this may race with ring_buffer_attach() (through set_output),
6410 * which will make us skip the event that actually needs to be stopped.
6411 * So ring_buffer_attach() has to stop an aux event before re-assigning
6414 if (rcu_dereference(parent
->rb
) == rb
)
6415 ro
->err
= __perf_event_stop(&sd
);
6418 static int __perf_pmu_output_stop(void *info
)
6420 struct perf_event
*event
= info
;
6421 struct pmu
*pmu
= event
->pmu
;
6422 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6423 struct remote_output ro
= {
6428 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6429 if (cpuctx
->task_ctx
)
6430 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6437 static void perf_pmu_output_stop(struct perf_event
*event
)
6439 struct perf_event
*iter
;
6444 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6446 * For per-CPU events, we need to make sure that neither they
6447 * nor their children are running; for cpu==-1 events it's
6448 * sufficient to stop the event itself if it's active, since
6449 * it can't have children.
6453 cpu
= READ_ONCE(iter
->oncpu
);
6458 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6459 if (err
== -EAGAIN
) {
6468 * task tracking -- fork/exit
6470 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6473 struct perf_task_event
{
6474 struct task_struct
*task
;
6475 struct perf_event_context
*task_ctx
;
6478 struct perf_event_header header
;
6488 static int perf_event_task_match(struct perf_event
*event
)
6490 return event
->attr
.comm
|| event
->attr
.mmap
||
6491 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6495 static void perf_event_task_output(struct perf_event
*event
,
6498 struct perf_task_event
*task_event
= data
;
6499 struct perf_output_handle handle
;
6500 struct perf_sample_data sample
;
6501 struct task_struct
*task
= task_event
->task
;
6502 int ret
, size
= task_event
->event_id
.header
.size
;
6504 if (!perf_event_task_match(event
))
6507 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6509 ret
= perf_output_begin(&handle
, event
,
6510 task_event
->event_id
.header
.size
);
6514 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6515 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6517 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6518 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6520 task_event
->event_id
.time
= perf_event_clock(event
);
6522 perf_output_put(&handle
, task_event
->event_id
);
6524 perf_event__output_id_sample(event
, &handle
, &sample
);
6526 perf_output_end(&handle
);
6528 task_event
->event_id
.header
.size
= size
;
6531 static void perf_event_task(struct task_struct
*task
,
6532 struct perf_event_context
*task_ctx
,
6535 struct perf_task_event task_event
;
6537 if (!atomic_read(&nr_comm_events
) &&
6538 !atomic_read(&nr_mmap_events
) &&
6539 !atomic_read(&nr_task_events
))
6542 task_event
= (struct perf_task_event
){
6544 .task_ctx
= task_ctx
,
6547 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6549 .size
= sizeof(task_event
.event_id
),
6559 perf_iterate_sb(perf_event_task_output
,
6564 void perf_event_fork(struct task_struct
*task
)
6566 perf_event_task(task
, NULL
, 1);
6567 perf_event_namespaces(task
);
6574 struct perf_comm_event
{
6575 struct task_struct
*task
;
6580 struct perf_event_header header
;
6587 static int perf_event_comm_match(struct perf_event
*event
)
6589 return event
->attr
.comm
;
6592 static void perf_event_comm_output(struct perf_event
*event
,
6595 struct perf_comm_event
*comm_event
= data
;
6596 struct perf_output_handle handle
;
6597 struct perf_sample_data sample
;
6598 int size
= comm_event
->event_id
.header
.size
;
6601 if (!perf_event_comm_match(event
))
6604 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6605 ret
= perf_output_begin(&handle
, event
,
6606 comm_event
->event_id
.header
.size
);
6611 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6612 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6614 perf_output_put(&handle
, comm_event
->event_id
);
6615 __output_copy(&handle
, comm_event
->comm
,
6616 comm_event
->comm_size
);
6618 perf_event__output_id_sample(event
, &handle
, &sample
);
6620 perf_output_end(&handle
);
6622 comm_event
->event_id
.header
.size
= size
;
6625 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6627 char comm
[TASK_COMM_LEN
];
6630 memset(comm
, 0, sizeof(comm
));
6631 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6632 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6634 comm_event
->comm
= comm
;
6635 comm_event
->comm_size
= size
;
6637 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6639 perf_iterate_sb(perf_event_comm_output
,
6644 void perf_event_comm(struct task_struct
*task
, bool exec
)
6646 struct perf_comm_event comm_event
;
6648 if (!atomic_read(&nr_comm_events
))
6651 comm_event
= (struct perf_comm_event
){
6657 .type
= PERF_RECORD_COMM
,
6658 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6666 perf_event_comm_event(&comm_event
);
6670 * namespaces tracking
6673 struct perf_namespaces_event
{
6674 struct task_struct
*task
;
6677 struct perf_event_header header
;
6682 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6686 static int perf_event_namespaces_match(struct perf_event
*event
)
6688 return event
->attr
.namespaces
;
6691 static void perf_event_namespaces_output(struct perf_event
*event
,
6694 struct perf_namespaces_event
*namespaces_event
= data
;
6695 struct perf_output_handle handle
;
6696 struct perf_sample_data sample
;
6697 u16 header_size
= namespaces_event
->event_id
.header
.size
;
6700 if (!perf_event_namespaces_match(event
))
6703 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6705 ret
= perf_output_begin(&handle
, event
,
6706 namespaces_event
->event_id
.header
.size
);
6710 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6711 namespaces_event
->task
);
6712 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6713 namespaces_event
->task
);
6715 perf_output_put(&handle
, namespaces_event
->event_id
);
6717 perf_event__output_id_sample(event
, &handle
, &sample
);
6719 perf_output_end(&handle
);
6721 namespaces_event
->event_id
.header
.size
= header_size
;
6724 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6725 struct task_struct
*task
,
6726 const struct proc_ns_operations
*ns_ops
)
6728 struct path ns_path
;
6729 struct inode
*ns_inode
;
6732 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6734 ns_inode
= ns_path
.dentry
->d_inode
;
6735 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6736 ns_link_info
->ino
= ns_inode
->i_ino
;
6741 void perf_event_namespaces(struct task_struct
*task
)
6743 struct perf_namespaces_event namespaces_event
;
6744 struct perf_ns_link_info
*ns_link_info
;
6746 if (!atomic_read(&nr_namespaces_events
))
6749 namespaces_event
= (struct perf_namespaces_event
){
6753 .type
= PERF_RECORD_NAMESPACES
,
6755 .size
= sizeof(namespaces_event
.event_id
),
6759 .nr_namespaces
= NR_NAMESPACES
,
6760 /* .link_info[NR_NAMESPACES] */
6764 ns_link_info
= namespaces_event
.event_id
.link_info
;
6766 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6767 task
, &mntns_operations
);
6769 #ifdef CONFIG_USER_NS
6770 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6771 task
, &userns_operations
);
6773 #ifdef CONFIG_NET_NS
6774 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6775 task
, &netns_operations
);
6777 #ifdef CONFIG_UTS_NS
6778 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6779 task
, &utsns_operations
);
6781 #ifdef CONFIG_IPC_NS
6782 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6783 task
, &ipcns_operations
);
6785 #ifdef CONFIG_PID_NS
6786 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6787 task
, &pidns_operations
);
6789 #ifdef CONFIG_CGROUPS
6790 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6791 task
, &cgroupns_operations
);
6794 perf_iterate_sb(perf_event_namespaces_output
,
6803 struct perf_mmap_event
{
6804 struct vm_area_struct
*vma
;
6806 const char *file_name
;
6814 struct perf_event_header header
;
6824 static int perf_event_mmap_match(struct perf_event
*event
,
6827 struct perf_mmap_event
*mmap_event
= data
;
6828 struct vm_area_struct
*vma
= mmap_event
->vma
;
6829 int executable
= vma
->vm_flags
& VM_EXEC
;
6831 return (!executable
&& event
->attr
.mmap_data
) ||
6832 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6835 static void perf_event_mmap_output(struct perf_event
*event
,
6838 struct perf_mmap_event
*mmap_event
= data
;
6839 struct perf_output_handle handle
;
6840 struct perf_sample_data sample
;
6841 int size
= mmap_event
->event_id
.header
.size
;
6844 if (!perf_event_mmap_match(event
, data
))
6847 if (event
->attr
.mmap2
) {
6848 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6849 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6850 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6851 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6852 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6853 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6854 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6857 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6858 ret
= perf_output_begin(&handle
, event
,
6859 mmap_event
->event_id
.header
.size
);
6863 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6864 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6866 perf_output_put(&handle
, mmap_event
->event_id
);
6868 if (event
->attr
.mmap2
) {
6869 perf_output_put(&handle
, mmap_event
->maj
);
6870 perf_output_put(&handle
, mmap_event
->min
);
6871 perf_output_put(&handle
, mmap_event
->ino
);
6872 perf_output_put(&handle
, mmap_event
->ino_generation
);
6873 perf_output_put(&handle
, mmap_event
->prot
);
6874 perf_output_put(&handle
, mmap_event
->flags
);
6877 __output_copy(&handle
, mmap_event
->file_name
,
6878 mmap_event
->file_size
);
6880 perf_event__output_id_sample(event
, &handle
, &sample
);
6882 perf_output_end(&handle
);
6884 mmap_event
->event_id
.header
.size
= size
;
6887 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6889 struct vm_area_struct
*vma
= mmap_event
->vma
;
6890 struct file
*file
= vma
->vm_file
;
6891 int maj
= 0, min
= 0;
6892 u64 ino
= 0, gen
= 0;
6893 u32 prot
= 0, flags
= 0;
6899 if (vma
->vm_flags
& VM_READ
)
6901 if (vma
->vm_flags
& VM_WRITE
)
6903 if (vma
->vm_flags
& VM_EXEC
)
6906 if (vma
->vm_flags
& VM_MAYSHARE
)
6909 flags
= MAP_PRIVATE
;
6911 if (vma
->vm_flags
& VM_DENYWRITE
)
6912 flags
|= MAP_DENYWRITE
;
6913 if (vma
->vm_flags
& VM_MAYEXEC
)
6914 flags
|= MAP_EXECUTABLE
;
6915 if (vma
->vm_flags
& VM_LOCKED
)
6916 flags
|= MAP_LOCKED
;
6917 if (vma
->vm_flags
& VM_HUGETLB
)
6918 flags
|= MAP_HUGETLB
;
6921 struct inode
*inode
;
6924 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6930 * d_path() works from the end of the rb backwards, so we
6931 * need to add enough zero bytes after the string to handle
6932 * the 64bit alignment we do later.
6934 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6939 inode
= file_inode(vma
->vm_file
);
6940 dev
= inode
->i_sb
->s_dev
;
6942 gen
= inode
->i_generation
;
6948 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6949 name
= (char *) vma
->vm_ops
->name(vma
);
6954 name
= (char *)arch_vma_name(vma
);
6958 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6959 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6963 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6964 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6974 strlcpy(tmp
, name
, sizeof(tmp
));
6978 * Since our buffer works in 8 byte units we need to align our string
6979 * size to a multiple of 8. However, we must guarantee the tail end is
6980 * zero'd out to avoid leaking random bits to userspace.
6982 size
= strlen(name
)+1;
6983 while (!IS_ALIGNED(size
, sizeof(u64
)))
6984 name
[size
++] = '\0';
6986 mmap_event
->file_name
= name
;
6987 mmap_event
->file_size
= size
;
6988 mmap_event
->maj
= maj
;
6989 mmap_event
->min
= min
;
6990 mmap_event
->ino
= ino
;
6991 mmap_event
->ino_generation
= gen
;
6992 mmap_event
->prot
= prot
;
6993 mmap_event
->flags
= flags
;
6995 if (!(vma
->vm_flags
& VM_EXEC
))
6996 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6998 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7000 perf_iterate_sb(perf_event_mmap_output
,
7008 * Check whether inode and address range match filter criteria.
7010 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7011 struct file
*file
, unsigned long offset
,
7014 if (filter
->inode
!= file_inode(file
))
7017 if (filter
->offset
> offset
+ size
)
7020 if (filter
->offset
+ filter
->size
< offset
)
7026 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7028 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7029 struct vm_area_struct
*vma
= data
;
7030 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
7031 struct file
*file
= vma
->vm_file
;
7032 struct perf_addr_filter
*filter
;
7033 unsigned int restart
= 0, count
= 0;
7035 if (!has_addr_filter(event
))
7041 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7042 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7043 if (perf_addr_filter_match(filter
, file
, off
,
7044 vma
->vm_end
- vma
->vm_start
)) {
7045 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7053 event
->addr_filters_gen
++;
7054 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7057 perf_event_stop(event
, 1);
7061 * Adjust all task's events' filters to the new vma
7063 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7065 struct perf_event_context
*ctx
;
7069 * Data tracing isn't supported yet and as such there is no need
7070 * to keep track of anything that isn't related to executable code:
7072 if (!(vma
->vm_flags
& VM_EXEC
))
7076 for_each_task_context_nr(ctxn
) {
7077 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7081 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7086 void perf_event_mmap(struct vm_area_struct
*vma
)
7088 struct perf_mmap_event mmap_event
;
7090 if (!atomic_read(&nr_mmap_events
))
7093 mmap_event
= (struct perf_mmap_event
){
7099 .type
= PERF_RECORD_MMAP
,
7100 .misc
= PERF_RECORD_MISC_USER
,
7105 .start
= vma
->vm_start
,
7106 .len
= vma
->vm_end
- vma
->vm_start
,
7107 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7109 /* .maj (attr_mmap2 only) */
7110 /* .min (attr_mmap2 only) */
7111 /* .ino (attr_mmap2 only) */
7112 /* .ino_generation (attr_mmap2 only) */
7113 /* .prot (attr_mmap2 only) */
7114 /* .flags (attr_mmap2 only) */
7117 perf_addr_filters_adjust(vma
);
7118 perf_event_mmap_event(&mmap_event
);
7121 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7122 unsigned long size
, u64 flags
)
7124 struct perf_output_handle handle
;
7125 struct perf_sample_data sample
;
7126 struct perf_aux_event
{
7127 struct perf_event_header header
;
7133 .type
= PERF_RECORD_AUX
,
7135 .size
= sizeof(rec
),
7143 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7144 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7149 perf_output_put(&handle
, rec
);
7150 perf_event__output_id_sample(event
, &handle
, &sample
);
7152 perf_output_end(&handle
);
7156 * Lost/dropped samples logging
7158 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7160 struct perf_output_handle handle
;
7161 struct perf_sample_data sample
;
7165 struct perf_event_header header
;
7167 } lost_samples_event
= {
7169 .type
= PERF_RECORD_LOST_SAMPLES
,
7171 .size
= sizeof(lost_samples_event
),
7176 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7178 ret
= perf_output_begin(&handle
, event
,
7179 lost_samples_event
.header
.size
);
7183 perf_output_put(&handle
, lost_samples_event
);
7184 perf_event__output_id_sample(event
, &handle
, &sample
);
7185 perf_output_end(&handle
);
7189 * context_switch tracking
7192 struct perf_switch_event
{
7193 struct task_struct
*task
;
7194 struct task_struct
*next_prev
;
7197 struct perf_event_header header
;
7203 static int perf_event_switch_match(struct perf_event
*event
)
7205 return event
->attr
.context_switch
;
7208 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7210 struct perf_switch_event
*se
= data
;
7211 struct perf_output_handle handle
;
7212 struct perf_sample_data sample
;
7215 if (!perf_event_switch_match(event
))
7218 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7219 if (event
->ctx
->task
) {
7220 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7221 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7223 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7224 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7225 se
->event_id
.next_prev_pid
=
7226 perf_event_pid(event
, se
->next_prev
);
7227 se
->event_id
.next_prev_tid
=
7228 perf_event_tid(event
, se
->next_prev
);
7231 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7233 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7237 if (event
->ctx
->task
)
7238 perf_output_put(&handle
, se
->event_id
.header
);
7240 perf_output_put(&handle
, se
->event_id
);
7242 perf_event__output_id_sample(event
, &handle
, &sample
);
7244 perf_output_end(&handle
);
7247 static void perf_event_switch(struct task_struct
*task
,
7248 struct task_struct
*next_prev
, bool sched_in
)
7250 struct perf_switch_event switch_event
;
7252 /* N.B. caller checks nr_switch_events != 0 */
7254 switch_event
= (struct perf_switch_event
){
7256 .next_prev
= next_prev
,
7260 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7263 /* .next_prev_pid */
7264 /* .next_prev_tid */
7268 perf_iterate_sb(perf_event_switch_output
,
7274 * IRQ throttle logging
7277 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7279 struct perf_output_handle handle
;
7280 struct perf_sample_data sample
;
7284 struct perf_event_header header
;
7288 } throttle_event
= {
7290 .type
= PERF_RECORD_THROTTLE
,
7292 .size
= sizeof(throttle_event
),
7294 .time
= perf_event_clock(event
),
7295 .id
= primary_event_id(event
),
7296 .stream_id
= event
->id
,
7300 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7302 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7304 ret
= perf_output_begin(&handle
, event
,
7305 throttle_event
.header
.size
);
7309 perf_output_put(&handle
, throttle_event
);
7310 perf_event__output_id_sample(event
, &handle
, &sample
);
7311 perf_output_end(&handle
);
7314 void perf_event_itrace_started(struct perf_event
*event
)
7316 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7319 static void perf_log_itrace_start(struct perf_event
*event
)
7321 struct perf_output_handle handle
;
7322 struct perf_sample_data sample
;
7323 struct perf_aux_event
{
7324 struct perf_event_header header
;
7331 event
= event
->parent
;
7333 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7334 event
->attach_state
& PERF_ATTACH_ITRACE
)
7337 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7338 rec
.header
.misc
= 0;
7339 rec
.header
.size
= sizeof(rec
);
7340 rec
.pid
= perf_event_pid(event
, current
);
7341 rec
.tid
= perf_event_tid(event
, current
);
7343 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7344 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7349 perf_output_put(&handle
, rec
);
7350 perf_event__output_id_sample(event
, &handle
, &sample
);
7352 perf_output_end(&handle
);
7356 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7358 struct hw_perf_event
*hwc
= &event
->hw
;
7362 seq
= __this_cpu_read(perf_throttled_seq
);
7363 if (seq
!= hwc
->interrupts_seq
) {
7364 hwc
->interrupts_seq
= seq
;
7365 hwc
->interrupts
= 1;
7368 if (unlikely(throttle
7369 && hwc
->interrupts
>= max_samples_per_tick
)) {
7370 __this_cpu_inc(perf_throttled_count
);
7371 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7372 hwc
->interrupts
= MAX_INTERRUPTS
;
7373 perf_log_throttle(event
, 0);
7378 if (event
->attr
.freq
) {
7379 u64 now
= perf_clock();
7380 s64 delta
= now
- hwc
->freq_time_stamp
;
7382 hwc
->freq_time_stamp
= now
;
7384 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7385 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7391 int perf_event_account_interrupt(struct perf_event
*event
)
7393 return __perf_event_account_interrupt(event
, 1);
7397 * Generic event overflow handling, sampling.
7400 static int __perf_event_overflow(struct perf_event
*event
,
7401 int throttle
, struct perf_sample_data
*data
,
7402 struct pt_regs
*regs
)
7404 int events
= atomic_read(&event
->event_limit
);
7408 * Non-sampling counters might still use the PMI to fold short
7409 * hardware counters, ignore those.
7411 if (unlikely(!is_sampling_event(event
)))
7414 ret
= __perf_event_account_interrupt(event
, throttle
);
7417 * XXX event_limit might not quite work as expected on inherited
7421 event
->pending_kill
= POLL_IN
;
7422 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7424 event
->pending_kill
= POLL_HUP
;
7426 perf_event_disable_inatomic(event
);
7429 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7431 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7432 event
->pending_wakeup
= 1;
7433 irq_work_queue(&event
->pending
);
7439 int perf_event_overflow(struct perf_event
*event
,
7440 struct perf_sample_data
*data
,
7441 struct pt_regs
*regs
)
7443 return __perf_event_overflow(event
, 1, data
, regs
);
7447 * Generic software event infrastructure
7450 struct swevent_htable
{
7451 struct swevent_hlist
*swevent_hlist
;
7452 struct mutex hlist_mutex
;
7455 /* Recursion avoidance in each contexts */
7456 int recursion
[PERF_NR_CONTEXTS
];
7459 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7462 * We directly increment event->count and keep a second value in
7463 * event->hw.period_left to count intervals. This period event
7464 * is kept in the range [-sample_period, 0] so that we can use the
7468 u64
perf_swevent_set_period(struct perf_event
*event
)
7470 struct hw_perf_event
*hwc
= &event
->hw
;
7471 u64 period
= hwc
->last_period
;
7475 hwc
->last_period
= hwc
->sample_period
;
7478 old
= val
= local64_read(&hwc
->period_left
);
7482 nr
= div64_u64(period
+ val
, period
);
7483 offset
= nr
* period
;
7485 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7491 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7492 struct perf_sample_data
*data
,
7493 struct pt_regs
*regs
)
7495 struct hw_perf_event
*hwc
= &event
->hw
;
7499 overflow
= perf_swevent_set_period(event
);
7501 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7504 for (; overflow
; overflow
--) {
7505 if (__perf_event_overflow(event
, throttle
,
7508 * We inhibit the overflow from happening when
7509 * hwc->interrupts == MAX_INTERRUPTS.
7517 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7518 struct perf_sample_data
*data
,
7519 struct pt_regs
*regs
)
7521 struct hw_perf_event
*hwc
= &event
->hw
;
7523 local64_add(nr
, &event
->count
);
7528 if (!is_sampling_event(event
))
7531 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7533 return perf_swevent_overflow(event
, 1, data
, regs
);
7535 data
->period
= event
->hw
.last_period
;
7537 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7538 return perf_swevent_overflow(event
, 1, data
, regs
);
7540 if (local64_add_negative(nr
, &hwc
->period_left
))
7543 perf_swevent_overflow(event
, 0, data
, regs
);
7546 static int perf_exclude_event(struct perf_event
*event
,
7547 struct pt_regs
*regs
)
7549 if (event
->hw
.state
& PERF_HES_STOPPED
)
7553 if (event
->attr
.exclude_user
&& user_mode(regs
))
7556 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7563 static int perf_swevent_match(struct perf_event
*event
,
7564 enum perf_type_id type
,
7566 struct perf_sample_data
*data
,
7567 struct pt_regs
*regs
)
7569 if (event
->attr
.type
!= type
)
7572 if (event
->attr
.config
!= event_id
)
7575 if (perf_exclude_event(event
, regs
))
7581 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7583 u64 val
= event_id
| (type
<< 32);
7585 return hash_64(val
, SWEVENT_HLIST_BITS
);
7588 static inline struct hlist_head
*
7589 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7591 u64 hash
= swevent_hash(type
, event_id
);
7593 return &hlist
->heads
[hash
];
7596 /* For the read side: events when they trigger */
7597 static inline struct hlist_head
*
7598 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7600 struct swevent_hlist
*hlist
;
7602 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7606 return __find_swevent_head(hlist
, type
, event_id
);
7609 /* For the event head insertion and removal in the hlist */
7610 static inline struct hlist_head
*
7611 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7613 struct swevent_hlist
*hlist
;
7614 u32 event_id
= event
->attr
.config
;
7615 u64 type
= event
->attr
.type
;
7618 * Event scheduling is always serialized against hlist allocation
7619 * and release. Which makes the protected version suitable here.
7620 * The context lock guarantees that.
7622 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7623 lockdep_is_held(&event
->ctx
->lock
));
7627 return __find_swevent_head(hlist
, type
, event_id
);
7630 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7632 struct perf_sample_data
*data
,
7633 struct pt_regs
*regs
)
7635 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7636 struct perf_event
*event
;
7637 struct hlist_head
*head
;
7640 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7644 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7645 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7646 perf_swevent_event(event
, nr
, data
, regs
);
7652 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7654 int perf_swevent_get_recursion_context(void)
7656 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7658 return get_recursion_context(swhash
->recursion
);
7660 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7662 void perf_swevent_put_recursion_context(int rctx
)
7664 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7666 put_recursion_context(swhash
->recursion
, rctx
);
7669 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7671 struct perf_sample_data data
;
7673 if (WARN_ON_ONCE(!regs
))
7676 perf_sample_data_init(&data
, addr
, 0);
7677 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7680 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7684 preempt_disable_notrace();
7685 rctx
= perf_swevent_get_recursion_context();
7686 if (unlikely(rctx
< 0))
7689 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7691 perf_swevent_put_recursion_context(rctx
);
7693 preempt_enable_notrace();
7696 static void perf_swevent_read(struct perf_event
*event
)
7700 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7702 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7703 struct hw_perf_event
*hwc
= &event
->hw
;
7704 struct hlist_head
*head
;
7706 if (is_sampling_event(event
)) {
7707 hwc
->last_period
= hwc
->sample_period
;
7708 perf_swevent_set_period(event
);
7711 hwc
->state
= !(flags
& PERF_EF_START
);
7713 head
= find_swevent_head(swhash
, event
);
7714 if (WARN_ON_ONCE(!head
))
7717 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7718 perf_event_update_userpage(event
);
7723 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7725 hlist_del_rcu(&event
->hlist_entry
);
7728 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7730 event
->hw
.state
= 0;
7733 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7735 event
->hw
.state
= PERF_HES_STOPPED
;
7738 /* Deref the hlist from the update side */
7739 static inline struct swevent_hlist
*
7740 swevent_hlist_deref(struct swevent_htable
*swhash
)
7742 return rcu_dereference_protected(swhash
->swevent_hlist
,
7743 lockdep_is_held(&swhash
->hlist_mutex
));
7746 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7748 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7753 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7754 kfree_rcu(hlist
, rcu_head
);
7757 static void swevent_hlist_put_cpu(int cpu
)
7759 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7761 mutex_lock(&swhash
->hlist_mutex
);
7763 if (!--swhash
->hlist_refcount
)
7764 swevent_hlist_release(swhash
);
7766 mutex_unlock(&swhash
->hlist_mutex
);
7769 static void swevent_hlist_put(void)
7773 for_each_possible_cpu(cpu
)
7774 swevent_hlist_put_cpu(cpu
);
7777 static int swevent_hlist_get_cpu(int cpu
)
7779 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7782 mutex_lock(&swhash
->hlist_mutex
);
7783 if (!swevent_hlist_deref(swhash
) &&
7784 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7785 struct swevent_hlist
*hlist
;
7787 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7792 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7794 swhash
->hlist_refcount
++;
7796 mutex_unlock(&swhash
->hlist_mutex
);
7801 static int swevent_hlist_get(void)
7803 int err
, cpu
, failed_cpu
;
7805 mutex_lock(&pmus_lock
);
7806 for_each_possible_cpu(cpu
) {
7807 err
= swevent_hlist_get_cpu(cpu
);
7813 mutex_unlock(&pmus_lock
);
7816 for_each_possible_cpu(cpu
) {
7817 if (cpu
== failed_cpu
)
7819 swevent_hlist_put_cpu(cpu
);
7821 mutex_unlock(&pmus_lock
);
7825 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7827 static void sw_perf_event_destroy(struct perf_event
*event
)
7829 u64 event_id
= event
->attr
.config
;
7831 WARN_ON(event
->parent
);
7833 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7834 swevent_hlist_put();
7837 static int perf_swevent_init(struct perf_event
*event
)
7839 u64 event_id
= event
->attr
.config
;
7841 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7845 * no branch sampling for software events
7847 if (has_branch_stack(event
))
7851 case PERF_COUNT_SW_CPU_CLOCK
:
7852 case PERF_COUNT_SW_TASK_CLOCK
:
7859 if (event_id
>= PERF_COUNT_SW_MAX
)
7862 if (!event
->parent
) {
7865 err
= swevent_hlist_get();
7869 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7870 event
->destroy
= sw_perf_event_destroy
;
7876 static struct pmu perf_swevent
= {
7877 .task_ctx_nr
= perf_sw_context
,
7879 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7881 .event_init
= perf_swevent_init
,
7882 .add
= perf_swevent_add
,
7883 .del
= perf_swevent_del
,
7884 .start
= perf_swevent_start
,
7885 .stop
= perf_swevent_stop
,
7886 .read
= perf_swevent_read
,
7889 #ifdef CONFIG_EVENT_TRACING
7891 static int perf_tp_filter_match(struct perf_event
*event
,
7892 struct perf_sample_data
*data
)
7894 void *record
= data
->raw
->frag
.data
;
7896 /* only top level events have filters set */
7898 event
= event
->parent
;
7900 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7905 static int perf_tp_event_match(struct perf_event
*event
,
7906 struct perf_sample_data
*data
,
7907 struct pt_regs
*regs
)
7909 if (event
->hw
.state
& PERF_HES_STOPPED
)
7912 * All tracepoints are from kernel-space.
7914 if (event
->attr
.exclude_kernel
)
7917 if (!perf_tp_filter_match(event
, data
))
7923 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7924 struct trace_event_call
*call
, u64 count
,
7925 struct pt_regs
*regs
, struct hlist_head
*head
,
7926 struct task_struct
*task
)
7928 if (bpf_prog_array_valid(call
)) {
7929 *(struct pt_regs
**)raw_data
= regs
;
7930 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
7931 perf_swevent_put_recursion_context(rctx
);
7935 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7938 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7940 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7941 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7942 struct task_struct
*task
)
7944 struct perf_sample_data data
;
7945 struct perf_event
*event
;
7947 struct perf_raw_record raw
= {
7954 perf_sample_data_init(&data
, 0, 0);
7957 perf_trace_buf_update(record
, event_type
);
7959 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7960 if (perf_tp_event_match(event
, &data
, regs
))
7961 perf_swevent_event(event
, count
, &data
, regs
);
7965 * If we got specified a target task, also iterate its context and
7966 * deliver this event there too.
7968 if (task
&& task
!= current
) {
7969 struct perf_event_context
*ctx
;
7970 struct trace_entry
*entry
= record
;
7973 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7977 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7978 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7980 if (event
->attr
.config
!= entry
->type
)
7982 if (perf_tp_event_match(event
, &data
, regs
))
7983 perf_swevent_event(event
, count
, &data
, regs
);
7989 perf_swevent_put_recursion_context(rctx
);
7991 EXPORT_SYMBOL_GPL(perf_tp_event
);
7993 static void tp_perf_event_destroy(struct perf_event
*event
)
7995 perf_trace_destroy(event
);
7998 static int perf_tp_event_init(struct perf_event
*event
)
8002 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8006 * no branch sampling for tracepoint events
8008 if (has_branch_stack(event
))
8011 err
= perf_trace_init(event
);
8015 event
->destroy
= tp_perf_event_destroy
;
8020 static struct pmu perf_tracepoint
= {
8021 .task_ctx_nr
= perf_sw_context
,
8023 .event_init
= perf_tp_event_init
,
8024 .add
= perf_trace_add
,
8025 .del
= perf_trace_del
,
8026 .start
= perf_swevent_start
,
8027 .stop
= perf_swevent_stop
,
8028 .read
= perf_swevent_read
,
8031 static inline void perf_tp_register(void)
8033 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8036 static void perf_event_free_filter(struct perf_event
*event
)
8038 ftrace_profile_free_filter(event
);
8041 #ifdef CONFIG_BPF_SYSCALL
8042 static void bpf_overflow_handler(struct perf_event
*event
,
8043 struct perf_sample_data
*data
,
8044 struct pt_regs
*regs
)
8046 struct bpf_perf_event_data_kern ctx
= {
8052 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
8054 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8057 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8060 __this_cpu_dec(bpf_prog_active
);
8065 event
->orig_overflow_handler(event
, data
, regs
);
8068 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8070 struct bpf_prog
*prog
;
8072 if (event
->overflow_handler_context
)
8073 /* hw breakpoint or kernel counter */
8079 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8081 return PTR_ERR(prog
);
8084 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8085 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8089 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8091 struct bpf_prog
*prog
= event
->prog
;
8096 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8101 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8105 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8110 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8112 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8113 struct bpf_prog
*prog
;
8116 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8117 return perf_event_set_bpf_handler(event
, prog_fd
);
8119 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8120 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8121 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8122 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8123 /* bpf programs can only be attached to u/kprobe or tracepoint */
8126 prog
= bpf_prog_get(prog_fd
);
8128 return PTR_ERR(prog
);
8130 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8131 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8132 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8133 /* valid fd, but invalid bpf program type */
8138 if (is_tracepoint
|| is_syscall_tp
) {
8139 int off
= trace_event_get_offsets(event
->tp_event
);
8141 if (prog
->aux
->max_ctx_offset
> off
) {
8147 ret
= perf_event_attach_bpf_prog(event
, prog
);
8153 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8155 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
) {
8156 perf_event_free_bpf_handler(event
);
8159 perf_event_detach_bpf_prog(event
);
8164 static inline void perf_tp_register(void)
8168 static void perf_event_free_filter(struct perf_event
*event
)
8172 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8177 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8180 #endif /* CONFIG_EVENT_TRACING */
8182 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8183 void perf_bp_event(struct perf_event
*bp
, void *data
)
8185 struct perf_sample_data sample
;
8186 struct pt_regs
*regs
= data
;
8188 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8190 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8191 perf_swevent_event(bp
, 1, &sample
, regs
);
8196 * Allocate a new address filter
8198 static struct perf_addr_filter
*
8199 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8201 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8202 struct perf_addr_filter
*filter
;
8204 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8208 INIT_LIST_HEAD(&filter
->entry
);
8209 list_add_tail(&filter
->entry
, filters
);
8214 static void free_filters_list(struct list_head
*filters
)
8216 struct perf_addr_filter
*filter
, *iter
;
8218 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8220 iput(filter
->inode
);
8221 list_del(&filter
->entry
);
8227 * Free existing address filters and optionally install new ones
8229 static void perf_addr_filters_splice(struct perf_event
*event
,
8230 struct list_head
*head
)
8232 unsigned long flags
;
8235 if (!has_addr_filter(event
))
8238 /* don't bother with children, they don't have their own filters */
8242 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8244 list_splice_init(&event
->addr_filters
.list
, &list
);
8246 list_splice(head
, &event
->addr_filters
.list
);
8248 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8250 free_filters_list(&list
);
8254 * Scan through mm's vmas and see if one of them matches the
8255 * @filter; if so, adjust filter's address range.
8256 * Called with mm::mmap_sem down for reading.
8258 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8259 struct mm_struct
*mm
)
8261 struct vm_area_struct
*vma
;
8263 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8264 struct file
*file
= vma
->vm_file
;
8265 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8266 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8271 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8274 return vma
->vm_start
;
8281 * Update event's address range filters based on the
8282 * task's existing mappings, if any.
8284 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8286 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8287 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8288 struct perf_addr_filter
*filter
;
8289 struct mm_struct
*mm
= NULL
;
8290 unsigned int count
= 0;
8291 unsigned long flags
;
8294 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8295 * will stop on the parent's child_mutex that our caller is also holding
8297 if (task
== TASK_TOMBSTONE
)
8300 if (!ifh
->nr_file_filters
)
8303 mm
= get_task_mm(event
->ctx
->task
);
8307 down_read(&mm
->mmap_sem
);
8309 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8310 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8311 event
->addr_filters_offs
[count
] = 0;
8314 * Adjust base offset if the filter is associated to a binary
8315 * that needs to be mapped:
8318 event
->addr_filters_offs
[count
] =
8319 perf_addr_filter_apply(filter
, mm
);
8324 event
->addr_filters_gen
++;
8325 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8327 up_read(&mm
->mmap_sem
);
8332 perf_event_stop(event
, 1);
8336 * Address range filtering: limiting the data to certain
8337 * instruction address ranges. Filters are ioctl()ed to us from
8338 * userspace as ascii strings.
8340 * Filter string format:
8343 * where ACTION is one of the
8344 * * "filter": limit the trace to this region
8345 * * "start": start tracing from this address
8346 * * "stop": stop tracing at this address/region;
8348 * * for kernel addresses: <start address>[/<size>]
8349 * * for object files: <start address>[/<size>]@</path/to/object/file>
8351 * if <size> is not specified, the range is treated as a single address.
8365 IF_STATE_ACTION
= 0,
8370 static const match_table_t if_tokens
= {
8371 { IF_ACT_FILTER
, "filter" },
8372 { IF_ACT_START
, "start" },
8373 { IF_ACT_STOP
, "stop" },
8374 { IF_SRC_FILE
, "%u/%u@%s" },
8375 { IF_SRC_KERNEL
, "%u/%u" },
8376 { IF_SRC_FILEADDR
, "%u@%s" },
8377 { IF_SRC_KERNELADDR
, "%u" },
8378 { IF_ACT_NONE
, NULL
},
8382 * Address filter string parser
8385 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8386 struct list_head
*filters
)
8388 struct perf_addr_filter
*filter
= NULL
;
8389 char *start
, *orig
, *filename
= NULL
;
8391 substring_t args
[MAX_OPT_ARGS
];
8392 int state
= IF_STATE_ACTION
, token
;
8393 unsigned int kernel
= 0;
8396 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8400 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8406 /* filter definition begins */
8407 if (state
== IF_STATE_ACTION
) {
8408 filter
= perf_addr_filter_new(event
, filters
);
8413 token
= match_token(start
, if_tokens
, args
);
8420 if (state
!= IF_STATE_ACTION
)
8423 state
= IF_STATE_SOURCE
;
8426 case IF_SRC_KERNELADDR
:
8430 case IF_SRC_FILEADDR
:
8432 if (state
!= IF_STATE_SOURCE
)
8435 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8439 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8443 if (filter
->range
) {
8445 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8450 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8451 int fpos
= filter
->range
? 2 : 1;
8453 filename
= match_strdup(&args
[fpos
]);
8460 state
= IF_STATE_END
;
8468 * Filter definition is fully parsed, validate and install it.
8469 * Make sure that it doesn't contradict itself or the event's
8472 if (state
== IF_STATE_END
) {
8474 if (kernel
&& event
->attr
.exclude_kernel
)
8482 * For now, we only support file-based filters
8483 * in per-task events; doing so for CPU-wide
8484 * events requires additional context switching
8485 * trickery, since same object code will be
8486 * mapped at different virtual addresses in
8487 * different processes.
8490 if (!event
->ctx
->task
)
8491 goto fail_free_name
;
8493 /* look up the path and grab its inode */
8494 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8496 goto fail_free_name
;
8498 filter
->inode
= igrab(d_inode(path
.dentry
));
8504 if (!filter
->inode
||
8505 !S_ISREG(filter
->inode
->i_mode
))
8506 /* free_filters_list() will iput() */
8509 event
->addr_filters
.nr_file_filters
++;
8512 /* ready to consume more filters */
8513 state
= IF_STATE_ACTION
;
8518 if (state
!= IF_STATE_ACTION
)
8528 free_filters_list(filters
);
8535 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8541 * Since this is called in perf_ioctl() path, we're already holding
8544 lockdep_assert_held(&event
->ctx
->mutex
);
8546 if (WARN_ON_ONCE(event
->parent
))
8549 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8551 goto fail_clear_files
;
8553 ret
= event
->pmu
->addr_filters_validate(&filters
);
8555 goto fail_free_filters
;
8557 /* remove existing filters, if any */
8558 perf_addr_filters_splice(event
, &filters
);
8560 /* install new filters */
8561 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8566 free_filters_list(&filters
);
8569 event
->addr_filters
.nr_file_filters
= 0;
8575 perf_tracepoint_set_filter(struct perf_event
*event
, char *filter_str
)
8577 struct perf_event_context
*ctx
= event
->ctx
;
8581 * Beware, here be dragons!!
8583 * the tracepoint muck will deadlock against ctx->mutex, but the tracepoint
8584 * stuff does not actually need it. So temporarily drop ctx->mutex. As per
8585 * perf_event_ctx_lock() we already have a reference on ctx.
8587 * This can result in event getting moved to a different ctx, but that
8588 * does not affect the tracepoint state.
8590 mutex_unlock(&ctx
->mutex
);
8591 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
8592 mutex_lock(&ctx
->mutex
);
8597 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8602 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8603 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8604 !has_addr_filter(event
))
8607 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8608 if (IS_ERR(filter_str
))
8609 return PTR_ERR(filter_str
);
8611 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8612 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8613 ret
= perf_tracepoint_set_filter(event
, filter_str
);
8614 else if (has_addr_filter(event
))
8615 ret
= perf_event_set_addr_filter(event
, filter_str
);
8622 * hrtimer based swevent callback
8625 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8627 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8628 struct perf_sample_data data
;
8629 struct pt_regs
*regs
;
8630 struct perf_event
*event
;
8633 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8635 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8636 return HRTIMER_NORESTART
;
8638 event
->pmu
->read(event
);
8640 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8641 regs
= get_irq_regs();
8643 if (regs
&& !perf_exclude_event(event
, regs
)) {
8644 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8645 if (__perf_event_overflow(event
, 1, &data
, regs
))
8646 ret
= HRTIMER_NORESTART
;
8649 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8650 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8655 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8657 struct hw_perf_event
*hwc
= &event
->hw
;
8660 if (!is_sampling_event(event
))
8663 period
= local64_read(&hwc
->period_left
);
8668 local64_set(&hwc
->period_left
, 0);
8670 period
= max_t(u64
, 10000, hwc
->sample_period
);
8672 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8673 HRTIMER_MODE_REL_PINNED
);
8676 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8678 struct hw_perf_event
*hwc
= &event
->hw
;
8680 if (is_sampling_event(event
)) {
8681 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8682 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8684 hrtimer_cancel(&hwc
->hrtimer
);
8688 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8690 struct hw_perf_event
*hwc
= &event
->hw
;
8692 if (!is_sampling_event(event
))
8695 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8696 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8699 * Since hrtimers have a fixed rate, we can do a static freq->period
8700 * mapping and avoid the whole period adjust feedback stuff.
8702 if (event
->attr
.freq
) {
8703 long freq
= event
->attr
.sample_freq
;
8705 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8706 hwc
->sample_period
= event
->attr
.sample_period
;
8707 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8708 hwc
->last_period
= hwc
->sample_period
;
8709 event
->attr
.freq
= 0;
8714 * Software event: cpu wall time clock
8717 static void cpu_clock_event_update(struct perf_event
*event
)
8722 now
= local_clock();
8723 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8724 local64_add(now
- prev
, &event
->count
);
8727 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8729 local64_set(&event
->hw
.prev_count
, local_clock());
8730 perf_swevent_start_hrtimer(event
);
8733 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8735 perf_swevent_cancel_hrtimer(event
);
8736 cpu_clock_event_update(event
);
8739 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8741 if (flags
& PERF_EF_START
)
8742 cpu_clock_event_start(event
, flags
);
8743 perf_event_update_userpage(event
);
8748 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8750 cpu_clock_event_stop(event
, flags
);
8753 static void cpu_clock_event_read(struct perf_event
*event
)
8755 cpu_clock_event_update(event
);
8758 static int cpu_clock_event_init(struct perf_event
*event
)
8760 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8763 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8767 * no branch sampling for software events
8769 if (has_branch_stack(event
))
8772 perf_swevent_init_hrtimer(event
);
8777 static struct pmu perf_cpu_clock
= {
8778 .task_ctx_nr
= perf_sw_context
,
8780 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8782 .event_init
= cpu_clock_event_init
,
8783 .add
= cpu_clock_event_add
,
8784 .del
= cpu_clock_event_del
,
8785 .start
= cpu_clock_event_start
,
8786 .stop
= cpu_clock_event_stop
,
8787 .read
= cpu_clock_event_read
,
8791 * Software event: task time clock
8794 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8799 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8801 local64_add(delta
, &event
->count
);
8804 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8806 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8807 perf_swevent_start_hrtimer(event
);
8810 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8812 perf_swevent_cancel_hrtimer(event
);
8813 task_clock_event_update(event
, event
->ctx
->time
);
8816 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8818 if (flags
& PERF_EF_START
)
8819 task_clock_event_start(event
, flags
);
8820 perf_event_update_userpage(event
);
8825 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8827 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8830 static void task_clock_event_read(struct perf_event
*event
)
8832 u64 now
= perf_clock();
8833 u64 delta
= now
- event
->ctx
->timestamp
;
8834 u64 time
= event
->ctx
->time
+ delta
;
8836 task_clock_event_update(event
, time
);
8839 static int task_clock_event_init(struct perf_event
*event
)
8841 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8844 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8848 * no branch sampling for software events
8850 if (has_branch_stack(event
))
8853 perf_swevent_init_hrtimer(event
);
8858 static struct pmu perf_task_clock
= {
8859 .task_ctx_nr
= perf_sw_context
,
8861 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8863 .event_init
= task_clock_event_init
,
8864 .add
= task_clock_event_add
,
8865 .del
= task_clock_event_del
,
8866 .start
= task_clock_event_start
,
8867 .stop
= task_clock_event_stop
,
8868 .read
= task_clock_event_read
,
8871 static void perf_pmu_nop_void(struct pmu
*pmu
)
8875 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8879 static int perf_pmu_nop_int(struct pmu
*pmu
)
8884 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8886 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8888 __this_cpu_write(nop_txn_flags
, flags
);
8890 if (flags
& ~PERF_PMU_TXN_ADD
)
8893 perf_pmu_disable(pmu
);
8896 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8898 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8900 __this_cpu_write(nop_txn_flags
, 0);
8902 if (flags
& ~PERF_PMU_TXN_ADD
)
8905 perf_pmu_enable(pmu
);
8909 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8911 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8913 __this_cpu_write(nop_txn_flags
, 0);
8915 if (flags
& ~PERF_PMU_TXN_ADD
)
8918 perf_pmu_enable(pmu
);
8921 static int perf_event_idx_default(struct perf_event
*event
)
8927 * Ensures all contexts with the same task_ctx_nr have the same
8928 * pmu_cpu_context too.
8930 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8937 list_for_each_entry(pmu
, &pmus
, entry
) {
8938 if (pmu
->task_ctx_nr
== ctxn
)
8939 return pmu
->pmu_cpu_context
;
8945 static void free_pmu_context(struct pmu
*pmu
)
8948 * Static contexts such as perf_sw_context have a global lifetime
8949 * and may be shared between different PMUs. Avoid freeing them
8950 * when a single PMU is going away.
8952 if (pmu
->task_ctx_nr
> perf_invalid_context
)
8955 mutex_lock(&pmus_lock
);
8956 free_percpu(pmu
->pmu_cpu_context
);
8957 mutex_unlock(&pmus_lock
);
8961 * Let userspace know that this PMU supports address range filtering:
8963 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8964 struct device_attribute
*attr
,
8967 struct pmu
*pmu
= dev_get_drvdata(dev
);
8969 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8971 DEVICE_ATTR_RO(nr_addr_filters
);
8973 static struct idr pmu_idr
;
8976 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8978 struct pmu
*pmu
= dev_get_drvdata(dev
);
8980 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8982 static DEVICE_ATTR_RO(type
);
8985 perf_event_mux_interval_ms_show(struct device
*dev
,
8986 struct device_attribute
*attr
,
8989 struct pmu
*pmu
= dev_get_drvdata(dev
);
8991 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8994 static DEFINE_MUTEX(mux_interval_mutex
);
8997 perf_event_mux_interval_ms_store(struct device
*dev
,
8998 struct device_attribute
*attr
,
8999 const char *buf
, size_t count
)
9001 struct pmu
*pmu
= dev_get_drvdata(dev
);
9002 int timer
, cpu
, ret
;
9004 ret
= kstrtoint(buf
, 0, &timer
);
9011 /* same value, noting to do */
9012 if (timer
== pmu
->hrtimer_interval_ms
)
9015 mutex_lock(&mux_interval_mutex
);
9016 pmu
->hrtimer_interval_ms
= timer
;
9018 /* update all cpuctx for this PMU */
9020 for_each_online_cpu(cpu
) {
9021 struct perf_cpu_context
*cpuctx
;
9022 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9023 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
9025 cpu_function_call(cpu
,
9026 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
9029 mutex_unlock(&mux_interval_mutex
);
9033 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
9035 static struct attribute
*pmu_dev_attrs
[] = {
9036 &dev_attr_type
.attr
,
9037 &dev_attr_perf_event_mux_interval_ms
.attr
,
9040 ATTRIBUTE_GROUPS(pmu_dev
);
9042 static int pmu_bus_running
;
9043 static struct bus_type pmu_bus
= {
9044 .name
= "event_source",
9045 .dev_groups
= pmu_dev_groups
,
9048 static void pmu_dev_release(struct device
*dev
)
9053 static int pmu_dev_alloc(struct pmu
*pmu
)
9057 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9061 pmu
->dev
->groups
= pmu
->attr_groups
;
9062 device_initialize(pmu
->dev
);
9063 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9067 dev_set_drvdata(pmu
->dev
, pmu
);
9068 pmu
->dev
->bus
= &pmu_bus
;
9069 pmu
->dev
->release
= pmu_dev_release
;
9070 ret
= device_add(pmu
->dev
);
9074 /* For PMUs with address filters, throw in an extra attribute: */
9075 if (pmu
->nr_addr_filters
)
9076 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9085 device_del(pmu
->dev
);
9088 put_device(pmu
->dev
);
9092 static struct lock_class_key cpuctx_mutex
;
9093 static struct lock_class_key cpuctx_lock
;
9095 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9099 mutex_lock(&pmus_lock
);
9101 pmu
->pmu_disable_count
= alloc_percpu(int);
9102 if (!pmu
->pmu_disable_count
)
9111 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9119 if (pmu_bus_running
) {
9120 ret
= pmu_dev_alloc(pmu
);
9126 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9127 static int hw_context_taken
= 0;
9130 * Other than systems with heterogeneous CPUs, it never makes
9131 * sense for two PMUs to share perf_hw_context. PMUs which are
9132 * uncore must use perf_invalid_context.
9134 if (WARN_ON_ONCE(hw_context_taken
&&
9135 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9136 pmu
->task_ctx_nr
= perf_invalid_context
;
9138 hw_context_taken
= 1;
9141 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9142 if (pmu
->pmu_cpu_context
)
9143 goto got_cpu_context
;
9146 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9147 if (!pmu
->pmu_cpu_context
)
9150 for_each_possible_cpu(cpu
) {
9151 struct perf_cpu_context
*cpuctx
;
9153 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9154 __perf_event_init_context(&cpuctx
->ctx
);
9155 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9156 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9157 cpuctx
->ctx
.pmu
= pmu
;
9158 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9160 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9164 if (!pmu
->start_txn
) {
9165 if (pmu
->pmu_enable
) {
9167 * If we have pmu_enable/pmu_disable calls, install
9168 * transaction stubs that use that to try and batch
9169 * hardware accesses.
9171 pmu
->start_txn
= perf_pmu_start_txn
;
9172 pmu
->commit_txn
= perf_pmu_commit_txn
;
9173 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9175 pmu
->start_txn
= perf_pmu_nop_txn
;
9176 pmu
->commit_txn
= perf_pmu_nop_int
;
9177 pmu
->cancel_txn
= perf_pmu_nop_void
;
9181 if (!pmu
->pmu_enable
) {
9182 pmu
->pmu_enable
= perf_pmu_nop_void
;
9183 pmu
->pmu_disable
= perf_pmu_nop_void
;
9186 if (!pmu
->event_idx
)
9187 pmu
->event_idx
= perf_event_idx_default
;
9189 list_add_rcu(&pmu
->entry
, &pmus
);
9190 atomic_set(&pmu
->exclusive_cnt
, 0);
9193 mutex_unlock(&pmus_lock
);
9198 device_del(pmu
->dev
);
9199 put_device(pmu
->dev
);
9202 if (pmu
->type
>= PERF_TYPE_MAX
)
9203 idr_remove(&pmu_idr
, pmu
->type
);
9206 free_percpu(pmu
->pmu_disable_count
);
9209 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9211 void perf_pmu_unregister(struct pmu
*pmu
)
9215 mutex_lock(&pmus_lock
);
9216 remove_device
= pmu_bus_running
;
9217 list_del_rcu(&pmu
->entry
);
9218 mutex_unlock(&pmus_lock
);
9221 * We dereference the pmu list under both SRCU and regular RCU, so
9222 * synchronize against both of those.
9224 synchronize_srcu(&pmus_srcu
);
9227 free_percpu(pmu
->pmu_disable_count
);
9228 if (pmu
->type
>= PERF_TYPE_MAX
)
9229 idr_remove(&pmu_idr
, pmu
->type
);
9230 if (remove_device
) {
9231 if (pmu
->nr_addr_filters
)
9232 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9233 device_del(pmu
->dev
);
9234 put_device(pmu
->dev
);
9236 free_pmu_context(pmu
);
9238 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9240 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9242 struct perf_event_context
*ctx
= NULL
;
9245 if (!try_module_get(pmu
->module
))
9249 * A number of pmu->event_init() methods iterate the sibling_list to,
9250 * for example, validate if the group fits on the PMU. Therefore,
9251 * if this is a sibling event, acquire the ctx->mutex to protect
9254 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
9256 * This ctx->mutex can nest when we're called through
9257 * inheritance. See the perf_event_ctx_lock_nested() comment.
9259 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9260 SINGLE_DEPTH_NESTING
);
9265 ret
= pmu
->event_init(event
);
9268 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9271 module_put(pmu
->module
);
9276 static struct pmu
*perf_init_event(struct perf_event
*event
)
9282 idx
= srcu_read_lock(&pmus_srcu
);
9284 /* Try parent's PMU first: */
9285 if (event
->parent
&& event
->parent
->pmu
) {
9286 pmu
= event
->parent
->pmu
;
9287 ret
= perf_try_init_event(pmu
, event
);
9293 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9296 ret
= perf_try_init_event(pmu
, event
);
9302 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9303 ret
= perf_try_init_event(pmu
, event
);
9307 if (ret
!= -ENOENT
) {
9312 pmu
= ERR_PTR(-ENOENT
);
9314 srcu_read_unlock(&pmus_srcu
, idx
);
9319 static void attach_sb_event(struct perf_event
*event
)
9321 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9323 raw_spin_lock(&pel
->lock
);
9324 list_add_rcu(&event
->sb_list
, &pel
->list
);
9325 raw_spin_unlock(&pel
->lock
);
9329 * We keep a list of all !task (and therefore per-cpu) events
9330 * that need to receive side-band records.
9332 * This avoids having to scan all the various PMU per-cpu contexts
9335 static void account_pmu_sb_event(struct perf_event
*event
)
9337 if (is_sb_event(event
))
9338 attach_sb_event(event
);
9341 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9346 if (is_cgroup_event(event
))
9347 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9350 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9351 static void account_freq_event_nohz(void)
9353 #ifdef CONFIG_NO_HZ_FULL
9354 /* Lock so we don't race with concurrent unaccount */
9355 spin_lock(&nr_freq_lock
);
9356 if (atomic_inc_return(&nr_freq_events
) == 1)
9357 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9358 spin_unlock(&nr_freq_lock
);
9362 static void account_freq_event(void)
9364 if (tick_nohz_full_enabled())
9365 account_freq_event_nohz();
9367 atomic_inc(&nr_freq_events
);
9371 static void account_event(struct perf_event
*event
)
9378 if (event
->attach_state
& PERF_ATTACH_TASK
)
9380 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9381 atomic_inc(&nr_mmap_events
);
9382 if (event
->attr
.comm
)
9383 atomic_inc(&nr_comm_events
);
9384 if (event
->attr
.namespaces
)
9385 atomic_inc(&nr_namespaces_events
);
9386 if (event
->attr
.task
)
9387 atomic_inc(&nr_task_events
);
9388 if (event
->attr
.freq
)
9389 account_freq_event();
9390 if (event
->attr
.context_switch
) {
9391 atomic_inc(&nr_switch_events
);
9394 if (has_branch_stack(event
))
9396 if (is_cgroup_event(event
))
9401 * We need the mutex here because static_branch_enable()
9402 * must complete *before* the perf_sched_count increment
9405 if (atomic_inc_not_zero(&perf_sched_count
))
9408 mutex_lock(&perf_sched_mutex
);
9409 if (!atomic_read(&perf_sched_count
)) {
9410 static_branch_enable(&perf_sched_events
);
9412 * Guarantee that all CPUs observe they key change and
9413 * call the perf scheduling hooks before proceeding to
9414 * install events that need them.
9416 synchronize_sched();
9419 * Now that we have waited for the sync_sched(), allow further
9420 * increments to by-pass the mutex.
9422 atomic_inc(&perf_sched_count
);
9423 mutex_unlock(&perf_sched_mutex
);
9427 account_event_cpu(event
, event
->cpu
);
9429 account_pmu_sb_event(event
);
9433 * Allocate and initialize a event structure
9435 static struct perf_event
*
9436 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9437 struct task_struct
*task
,
9438 struct perf_event
*group_leader
,
9439 struct perf_event
*parent_event
,
9440 perf_overflow_handler_t overflow_handler
,
9441 void *context
, int cgroup_fd
)
9444 struct perf_event
*event
;
9445 struct hw_perf_event
*hwc
;
9448 if ((unsigned)cpu
>= nr_cpu_ids
) {
9449 if (!task
|| cpu
!= -1)
9450 return ERR_PTR(-EINVAL
);
9453 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9455 return ERR_PTR(-ENOMEM
);
9458 * Single events are their own group leaders, with an
9459 * empty sibling list:
9462 group_leader
= event
;
9464 mutex_init(&event
->child_mutex
);
9465 INIT_LIST_HEAD(&event
->child_list
);
9467 INIT_LIST_HEAD(&event
->group_entry
);
9468 INIT_LIST_HEAD(&event
->event_entry
);
9469 INIT_LIST_HEAD(&event
->sibling_list
);
9470 INIT_LIST_HEAD(&event
->rb_entry
);
9471 INIT_LIST_HEAD(&event
->active_entry
);
9472 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9473 INIT_HLIST_NODE(&event
->hlist_entry
);
9476 init_waitqueue_head(&event
->waitq
);
9477 init_irq_work(&event
->pending
, perf_pending_event
);
9479 mutex_init(&event
->mmap_mutex
);
9480 raw_spin_lock_init(&event
->addr_filters
.lock
);
9482 atomic_long_set(&event
->refcount
, 1);
9484 event
->attr
= *attr
;
9485 event
->group_leader
= group_leader
;
9489 event
->parent
= parent_event
;
9491 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9492 event
->id
= atomic64_inc_return(&perf_event_id
);
9494 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9497 event
->attach_state
= PERF_ATTACH_TASK
;
9499 * XXX pmu::event_init needs to know what task to account to
9500 * and we cannot use the ctx information because we need the
9501 * pmu before we get a ctx.
9503 get_task_struct(task
);
9504 event
->hw
.target
= task
;
9507 event
->clock
= &local_clock
;
9509 event
->clock
= parent_event
->clock
;
9511 if (!overflow_handler
&& parent_event
) {
9512 overflow_handler
= parent_event
->overflow_handler
;
9513 context
= parent_event
->overflow_handler_context
;
9514 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9515 if (overflow_handler
== bpf_overflow_handler
) {
9516 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9519 err
= PTR_ERR(prog
);
9523 event
->orig_overflow_handler
=
9524 parent_event
->orig_overflow_handler
;
9529 if (overflow_handler
) {
9530 event
->overflow_handler
= overflow_handler
;
9531 event
->overflow_handler_context
= context
;
9532 } else if (is_write_backward(event
)){
9533 event
->overflow_handler
= perf_event_output_backward
;
9534 event
->overflow_handler_context
= NULL
;
9536 event
->overflow_handler
= perf_event_output_forward
;
9537 event
->overflow_handler_context
= NULL
;
9540 perf_event__state_init(event
);
9545 hwc
->sample_period
= attr
->sample_period
;
9546 if (attr
->freq
&& attr
->sample_freq
)
9547 hwc
->sample_period
= 1;
9548 hwc
->last_period
= hwc
->sample_period
;
9550 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9553 * We currently do not support PERF_SAMPLE_READ on inherited events.
9554 * See perf_output_read().
9556 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9559 if (!has_branch_stack(event
))
9560 event
->attr
.branch_sample_type
= 0;
9562 if (cgroup_fd
!= -1) {
9563 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9568 pmu
= perf_init_event(event
);
9574 err
= exclusive_event_init(event
);
9578 if (has_addr_filter(event
)) {
9579 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9580 sizeof(unsigned long),
9582 if (!event
->addr_filters_offs
) {
9587 /* force hw sync on the address filters */
9588 event
->addr_filters_gen
= 1;
9591 if (!event
->parent
) {
9592 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9593 err
= get_callchain_buffers(attr
->sample_max_stack
);
9595 goto err_addr_filters
;
9599 /* symmetric to unaccount_event() in _free_event() */
9600 account_event(event
);
9605 kfree(event
->addr_filters_offs
);
9608 exclusive_event_destroy(event
);
9612 event
->destroy(event
);
9613 module_put(pmu
->module
);
9615 if (is_cgroup_event(event
))
9616 perf_detach_cgroup(event
);
9618 put_pid_ns(event
->ns
);
9619 if (event
->hw
.target
)
9620 put_task_struct(event
->hw
.target
);
9623 return ERR_PTR(err
);
9626 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9627 struct perf_event_attr
*attr
)
9632 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9636 * zero the full structure, so that a short copy will be nice.
9638 memset(attr
, 0, sizeof(*attr
));
9640 ret
= get_user(size
, &uattr
->size
);
9644 if (size
> PAGE_SIZE
) /* silly large */
9647 if (!size
) /* abi compat */
9648 size
= PERF_ATTR_SIZE_VER0
;
9650 if (size
< PERF_ATTR_SIZE_VER0
)
9654 * If we're handed a bigger struct than we know of,
9655 * ensure all the unknown bits are 0 - i.e. new
9656 * user-space does not rely on any kernel feature
9657 * extensions we dont know about yet.
9659 if (size
> sizeof(*attr
)) {
9660 unsigned char __user
*addr
;
9661 unsigned char __user
*end
;
9664 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9665 end
= (void __user
*)uattr
+ size
;
9667 for (; addr
< end
; addr
++) {
9668 ret
= get_user(val
, addr
);
9674 size
= sizeof(*attr
);
9677 ret
= copy_from_user(attr
, uattr
, size
);
9683 if (attr
->__reserved_1
)
9686 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9689 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9692 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9693 u64 mask
= attr
->branch_sample_type
;
9695 /* only using defined bits */
9696 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9699 /* at least one branch bit must be set */
9700 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9703 /* propagate priv level, when not set for branch */
9704 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9706 /* exclude_kernel checked on syscall entry */
9707 if (!attr
->exclude_kernel
)
9708 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9710 if (!attr
->exclude_user
)
9711 mask
|= PERF_SAMPLE_BRANCH_USER
;
9713 if (!attr
->exclude_hv
)
9714 mask
|= PERF_SAMPLE_BRANCH_HV
;
9716 * adjust user setting (for HW filter setup)
9718 attr
->branch_sample_type
= mask
;
9720 /* privileged levels capture (kernel, hv): check permissions */
9721 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9722 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9726 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9727 ret
= perf_reg_validate(attr
->sample_regs_user
);
9732 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9733 if (!arch_perf_have_user_stack_dump())
9737 * We have __u32 type for the size, but so far
9738 * we can only use __u16 as maximum due to the
9739 * __u16 sample size limit.
9741 if (attr
->sample_stack_user
>= USHRT_MAX
)
9743 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9747 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9748 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9753 put_user(sizeof(*attr
), &uattr
->size
);
9759 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9761 struct ring_buffer
*rb
= NULL
;
9767 /* don't allow circular references */
9768 if (event
== output_event
)
9772 * Don't allow cross-cpu buffers
9774 if (output_event
->cpu
!= event
->cpu
)
9778 * If its not a per-cpu rb, it must be the same task.
9780 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9784 * Mixing clocks in the same buffer is trouble you don't need.
9786 if (output_event
->clock
!= event
->clock
)
9790 * Either writing ring buffer from beginning or from end.
9791 * Mixing is not allowed.
9793 if (is_write_backward(output_event
) != is_write_backward(event
))
9797 * If both events generate aux data, they must be on the same PMU
9799 if (has_aux(event
) && has_aux(output_event
) &&
9800 event
->pmu
!= output_event
->pmu
)
9804 mutex_lock(&event
->mmap_mutex
);
9805 /* Can't redirect output if we've got an active mmap() */
9806 if (atomic_read(&event
->mmap_count
))
9810 /* get the rb we want to redirect to */
9811 rb
= ring_buffer_get(output_event
);
9816 ring_buffer_attach(event
, rb
);
9820 mutex_unlock(&event
->mmap_mutex
);
9826 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9832 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9835 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9837 bool nmi_safe
= false;
9840 case CLOCK_MONOTONIC
:
9841 event
->clock
= &ktime_get_mono_fast_ns
;
9845 case CLOCK_MONOTONIC_RAW
:
9846 event
->clock
= &ktime_get_raw_fast_ns
;
9850 case CLOCK_REALTIME
:
9851 event
->clock
= &ktime_get_real_ns
;
9854 case CLOCK_BOOTTIME
:
9855 event
->clock
= &ktime_get_boot_ns
;
9859 event
->clock
= &ktime_get_tai_ns
;
9866 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9873 * Variation on perf_event_ctx_lock_nested(), except we take two context
9876 static struct perf_event_context
*
9877 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9878 struct perf_event_context
*ctx
)
9880 struct perf_event_context
*gctx
;
9884 gctx
= READ_ONCE(group_leader
->ctx
);
9885 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9891 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9893 if (group_leader
->ctx
!= gctx
) {
9894 mutex_unlock(&ctx
->mutex
);
9895 mutex_unlock(&gctx
->mutex
);
9904 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9906 * @attr_uptr: event_id type attributes for monitoring/sampling
9909 * @group_fd: group leader event fd
9911 SYSCALL_DEFINE5(perf_event_open
,
9912 struct perf_event_attr __user
*, attr_uptr
,
9913 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9915 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9916 struct perf_event
*event
, *sibling
;
9917 struct perf_event_attr attr
;
9918 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9919 struct file
*event_file
= NULL
;
9920 struct fd group
= {NULL
, 0};
9921 struct task_struct
*task
= NULL
;
9926 int f_flags
= O_RDWR
;
9929 /* for future expandability... */
9930 if (flags
& ~PERF_FLAG_ALL
)
9933 if (perf_paranoid_any() && !capable(CAP_SYS_ADMIN
))
9936 err
= perf_copy_attr(attr_uptr
, &attr
);
9940 if (!attr
.exclude_kernel
) {
9941 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9945 if (attr
.namespaces
) {
9946 if (!capable(CAP_SYS_ADMIN
))
9951 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9954 if (attr
.sample_period
& (1ULL << 63))
9958 /* Only privileged users can get physical addresses */
9959 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
9960 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9963 if (!attr
.sample_max_stack
)
9964 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9967 * In cgroup mode, the pid argument is used to pass the fd
9968 * opened to the cgroup directory in cgroupfs. The cpu argument
9969 * designates the cpu on which to monitor threads from that
9972 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9975 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9976 f_flags
|= O_CLOEXEC
;
9978 event_fd
= get_unused_fd_flags(f_flags
);
9982 if (group_fd
!= -1) {
9983 err
= perf_fget_light(group_fd
, &group
);
9986 group_leader
= group
.file
->private_data
;
9987 if (flags
& PERF_FLAG_FD_OUTPUT
)
9988 output_event
= group_leader
;
9989 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9990 group_leader
= NULL
;
9993 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9994 task
= find_lively_task_by_vpid(pid
);
9996 err
= PTR_ERR(task
);
10001 if (task
&& group_leader
&&
10002 group_leader
->attr
.inherit
!= attr
.inherit
) {
10008 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
10013 * Reuse ptrace permission checks for now.
10015 * We must hold cred_guard_mutex across this and any potential
10016 * perf_install_in_context() call for this new event to
10017 * serialize against exec() altering our credentials (and the
10018 * perf_event_exit_task() that could imply).
10021 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
10025 if (flags
& PERF_FLAG_PID_CGROUP
)
10028 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
10029 NULL
, NULL
, cgroup_fd
);
10030 if (IS_ERR(event
)) {
10031 err
= PTR_ERR(event
);
10035 if (is_sampling_event(event
)) {
10036 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
10043 * Special case software events and allow them to be part of
10044 * any hardware group.
10048 if (attr
.use_clockid
) {
10049 err
= perf_event_set_clock(event
, attr
.clockid
);
10054 if (pmu
->task_ctx_nr
== perf_sw_context
)
10055 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
10057 if (group_leader
&&
10058 (is_software_event(event
) != is_software_event(group_leader
))) {
10059 if (is_software_event(event
)) {
10061 * If event and group_leader are not both a software
10062 * event, and event is, then group leader is not.
10064 * Allow the addition of software events to !software
10065 * groups, this is safe because software events never
10066 * fail to schedule.
10068 pmu
= group_leader
->pmu
;
10069 } else if (is_software_event(group_leader
) &&
10070 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10072 * In case the group is a pure software group, and we
10073 * try to add a hardware event, move the whole group to
10074 * the hardware context.
10081 * Get the target context (task or percpu):
10083 ctx
= find_get_context(pmu
, task
, event
);
10085 err
= PTR_ERR(ctx
);
10089 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10095 * Look up the group leader (we will attach this event to it):
10097 if (group_leader
) {
10101 * Do not allow a recursive hierarchy (this new sibling
10102 * becoming part of another group-sibling):
10104 if (group_leader
->group_leader
!= group_leader
)
10107 /* All events in a group should have the same clock */
10108 if (group_leader
->clock
!= event
->clock
)
10112 * Make sure we're both events for the same CPU;
10113 * grouping events for different CPUs is broken; since
10114 * you can never concurrently schedule them anyhow.
10116 if (group_leader
->cpu
!= event
->cpu
)
10120 * Make sure we're both on the same task, or both
10123 if (group_leader
->ctx
->task
!= ctx
->task
)
10127 * Do not allow to attach to a group in a different task
10128 * or CPU context. If we're moving SW events, we'll fix
10129 * this up later, so allow that.
10131 if (!move_group
&& group_leader
->ctx
!= ctx
)
10135 * Only a group leader can be exclusive or pinned
10137 if (attr
.exclusive
|| attr
.pinned
)
10141 if (output_event
) {
10142 err
= perf_event_set_output(event
, output_event
);
10147 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10149 if (IS_ERR(event_file
)) {
10150 err
= PTR_ERR(event_file
);
10156 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10158 if (gctx
->task
== TASK_TOMBSTONE
) {
10164 * Check if we raced against another sys_perf_event_open() call
10165 * moving the software group underneath us.
10167 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10169 * If someone moved the group out from under us, check
10170 * if this new event wound up on the same ctx, if so
10171 * its the regular !move_group case, otherwise fail.
10177 perf_event_ctx_unlock(group_leader
, gctx
);
10182 mutex_lock(&ctx
->mutex
);
10185 if (ctx
->task
== TASK_TOMBSTONE
) {
10190 if (!perf_event_validate_size(event
)) {
10197 * Check if the @cpu we're creating an event for is online.
10199 * We use the perf_cpu_context::ctx::mutex to serialize against
10200 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10202 struct perf_cpu_context
*cpuctx
=
10203 container_of(ctx
, struct perf_cpu_context
, ctx
);
10205 if (!cpuctx
->online
) {
10213 * Must be under the same ctx::mutex as perf_install_in_context(),
10214 * because we need to serialize with concurrent event creation.
10216 if (!exclusive_event_installable(event
, ctx
)) {
10217 /* exclusive and group stuff are assumed mutually exclusive */
10218 WARN_ON_ONCE(move_group
);
10224 WARN_ON_ONCE(ctx
->parent_ctx
);
10227 * This is the point on no return; we cannot fail hereafter. This is
10228 * where we start modifying current state.
10233 * See perf_event_ctx_lock() for comments on the details
10234 * of swizzling perf_event::ctx.
10236 perf_remove_from_context(group_leader
, 0);
10239 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10241 perf_remove_from_context(sibling
, 0);
10246 * Wait for everybody to stop referencing the events through
10247 * the old lists, before installing it on new lists.
10252 * Install the group siblings before the group leader.
10254 * Because a group leader will try and install the entire group
10255 * (through the sibling list, which is still in-tact), we can
10256 * end up with siblings installed in the wrong context.
10258 * By installing siblings first we NO-OP because they're not
10259 * reachable through the group lists.
10261 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10263 perf_event__state_init(sibling
);
10264 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10269 * Removing from the context ends up with disabled
10270 * event. What we want here is event in the initial
10271 * startup state, ready to be add into new context.
10273 perf_event__state_init(group_leader
);
10274 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10279 * Precalculate sample_data sizes; do while holding ctx::mutex such
10280 * that we're serialized against further additions and before
10281 * perf_install_in_context() which is the point the event is active and
10282 * can use these values.
10284 perf_event__header_size(event
);
10285 perf_event__id_header_size(event
);
10287 event
->owner
= current
;
10289 perf_install_in_context(ctx
, event
, event
->cpu
);
10290 perf_unpin_context(ctx
);
10293 perf_event_ctx_unlock(group_leader
, gctx
);
10294 mutex_unlock(&ctx
->mutex
);
10297 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10298 put_task_struct(task
);
10301 mutex_lock(¤t
->perf_event_mutex
);
10302 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10303 mutex_unlock(¤t
->perf_event_mutex
);
10306 * Drop the reference on the group_event after placing the
10307 * new event on the sibling_list. This ensures destruction
10308 * of the group leader will find the pointer to itself in
10309 * perf_group_detach().
10312 fd_install(event_fd
, event_file
);
10317 perf_event_ctx_unlock(group_leader
, gctx
);
10318 mutex_unlock(&ctx
->mutex
);
10322 perf_unpin_context(ctx
);
10326 * If event_file is set, the fput() above will have called ->release()
10327 * and that will take care of freeing the event.
10333 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10336 put_task_struct(task
);
10340 put_unused_fd(event_fd
);
10345 * perf_event_create_kernel_counter
10347 * @attr: attributes of the counter to create
10348 * @cpu: cpu in which the counter is bound
10349 * @task: task to profile (NULL for percpu)
10351 struct perf_event
*
10352 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10353 struct task_struct
*task
,
10354 perf_overflow_handler_t overflow_handler
,
10357 struct perf_event_context
*ctx
;
10358 struct perf_event
*event
;
10362 * Get the target context (task or percpu):
10365 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10366 overflow_handler
, context
, -1);
10367 if (IS_ERR(event
)) {
10368 err
= PTR_ERR(event
);
10372 /* Mark owner so we could distinguish it from user events. */
10373 event
->owner
= TASK_TOMBSTONE
;
10375 ctx
= find_get_context(event
->pmu
, task
, event
);
10377 err
= PTR_ERR(ctx
);
10381 WARN_ON_ONCE(ctx
->parent_ctx
);
10382 mutex_lock(&ctx
->mutex
);
10383 if (ctx
->task
== TASK_TOMBSTONE
) {
10390 * Check if the @cpu we're creating an event for is online.
10392 * We use the perf_cpu_context::ctx::mutex to serialize against
10393 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10395 struct perf_cpu_context
*cpuctx
=
10396 container_of(ctx
, struct perf_cpu_context
, ctx
);
10397 if (!cpuctx
->online
) {
10403 if (!exclusive_event_installable(event
, ctx
)) {
10408 perf_install_in_context(ctx
, event
, cpu
);
10409 perf_unpin_context(ctx
);
10410 mutex_unlock(&ctx
->mutex
);
10415 mutex_unlock(&ctx
->mutex
);
10416 perf_unpin_context(ctx
);
10421 return ERR_PTR(err
);
10423 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10425 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10427 struct perf_event_context
*src_ctx
;
10428 struct perf_event_context
*dst_ctx
;
10429 struct perf_event
*event
, *tmp
;
10432 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10433 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10436 * See perf_event_ctx_lock() for comments on the details
10437 * of swizzling perf_event::ctx.
10439 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10440 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10442 perf_remove_from_context(event
, 0);
10443 unaccount_event_cpu(event
, src_cpu
);
10445 list_add(&event
->migrate_entry
, &events
);
10449 * Wait for the events to quiesce before re-instating them.
10454 * Re-instate events in 2 passes.
10456 * Skip over group leaders and only install siblings on this first
10457 * pass, siblings will not get enabled without a leader, however a
10458 * leader will enable its siblings, even if those are still on the old
10461 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10462 if (event
->group_leader
== event
)
10465 list_del(&event
->migrate_entry
);
10466 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10467 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10468 account_event_cpu(event
, dst_cpu
);
10469 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10474 * Once all the siblings are setup properly, install the group leaders
10477 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10478 list_del(&event
->migrate_entry
);
10479 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10480 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10481 account_event_cpu(event
, dst_cpu
);
10482 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10485 mutex_unlock(&dst_ctx
->mutex
);
10486 mutex_unlock(&src_ctx
->mutex
);
10488 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10490 static void sync_child_event(struct perf_event
*child_event
,
10491 struct task_struct
*child
)
10493 struct perf_event
*parent_event
= child_event
->parent
;
10496 if (child_event
->attr
.inherit_stat
)
10497 perf_event_read_event(child_event
, child
);
10499 child_val
= perf_event_count(child_event
);
10502 * Add back the child's count to the parent's count:
10504 atomic64_add(child_val
, &parent_event
->child_count
);
10505 atomic64_add(child_event
->total_time_enabled
,
10506 &parent_event
->child_total_time_enabled
);
10507 atomic64_add(child_event
->total_time_running
,
10508 &parent_event
->child_total_time_running
);
10512 perf_event_exit_event(struct perf_event
*child_event
,
10513 struct perf_event_context
*child_ctx
,
10514 struct task_struct
*child
)
10516 struct perf_event
*parent_event
= child_event
->parent
;
10519 * Do not destroy the 'original' grouping; because of the context
10520 * switch optimization the original events could've ended up in a
10521 * random child task.
10523 * If we were to destroy the original group, all group related
10524 * operations would cease to function properly after this random
10527 * Do destroy all inherited groups, we don't care about those
10528 * and being thorough is better.
10530 raw_spin_lock_irq(&child_ctx
->lock
);
10531 WARN_ON_ONCE(child_ctx
->is_active
);
10534 perf_group_detach(child_event
);
10535 list_del_event(child_event
, child_ctx
);
10536 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
10537 raw_spin_unlock_irq(&child_ctx
->lock
);
10540 * Parent events are governed by their filedesc, retain them.
10542 if (!parent_event
) {
10543 perf_event_wakeup(child_event
);
10547 * Child events can be cleaned up.
10550 sync_child_event(child_event
, child
);
10553 * Remove this event from the parent's list
10555 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10556 mutex_lock(&parent_event
->child_mutex
);
10557 list_del_init(&child_event
->child_list
);
10558 mutex_unlock(&parent_event
->child_mutex
);
10561 * Kick perf_poll() for is_event_hup().
10563 perf_event_wakeup(parent_event
);
10564 free_event(child_event
);
10565 put_event(parent_event
);
10568 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10570 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10571 struct perf_event
*child_event
, *next
;
10573 WARN_ON_ONCE(child
!= current
);
10575 child_ctx
= perf_pin_task_context(child
, ctxn
);
10580 * In order to reduce the amount of tricky in ctx tear-down, we hold
10581 * ctx::mutex over the entire thing. This serializes against almost
10582 * everything that wants to access the ctx.
10584 * The exception is sys_perf_event_open() /
10585 * perf_event_create_kernel_count() which does find_get_context()
10586 * without ctx::mutex (it cannot because of the move_group double mutex
10587 * lock thing). See the comments in perf_install_in_context().
10589 mutex_lock(&child_ctx
->mutex
);
10592 * In a single ctx::lock section, de-schedule the events and detach the
10593 * context from the task such that we cannot ever get it scheduled back
10596 raw_spin_lock_irq(&child_ctx
->lock
);
10597 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10600 * Now that the context is inactive, destroy the task <-> ctx relation
10601 * and mark the context dead.
10603 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10604 put_ctx(child_ctx
); /* cannot be last */
10605 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10606 put_task_struct(current
); /* cannot be last */
10608 clone_ctx
= unclone_ctx(child_ctx
);
10609 raw_spin_unlock_irq(&child_ctx
->lock
);
10612 put_ctx(clone_ctx
);
10615 * Report the task dead after unscheduling the events so that we
10616 * won't get any samples after PERF_RECORD_EXIT. We can however still
10617 * get a few PERF_RECORD_READ events.
10619 perf_event_task(child
, child_ctx
, 0);
10621 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10622 perf_event_exit_event(child_event
, child_ctx
, child
);
10624 mutex_unlock(&child_ctx
->mutex
);
10626 put_ctx(child_ctx
);
10630 * When a child task exits, feed back event values to parent events.
10632 * Can be called with cred_guard_mutex held when called from
10633 * install_exec_creds().
10635 void perf_event_exit_task(struct task_struct
*child
)
10637 struct perf_event
*event
, *tmp
;
10640 mutex_lock(&child
->perf_event_mutex
);
10641 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10643 list_del_init(&event
->owner_entry
);
10646 * Ensure the list deletion is visible before we clear
10647 * the owner, closes a race against perf_release() where
10648 * we need to serialize on the owner->perf_event_mutex.
10650 smp_store_release(&event
->owner
, NULL
);
10652 mutex_unlock(&child
->perf_event_mutex
);
10654 for_each_task_context_nr(ctxn
)
10655 perf_event_exit_task_context(child
, ctxn
);
10658 * The perf_event_exit_task_context calls perf_event_task
10659 * with child's task_ctx, which generates EXIT events for
10660 * child contexts and sets child->perf_event_ctxp[] to NULL.
10661 * At this point we need to send EXIT events to cpu contexts.
10663 perf_event_task(child
, NULL
, 0);
10666 static void perf_free_event(struct perf_event
*event
,
10667 struct perf_event_context
*ctx
)
10669 struct perf_event
*parent
= event
->parent
;
10671 if (WARN_ON_ONCE(!parent
))
10674 mutex_lock(&parent
->child_mutex
);
10675 list_del_init(&event
->child_list
);
10676 mutex_unlock(&parent
->child_mutex
);
10680 raw_spin_lock_irq(&ctx
->lock
);
10681 perf_group_detach(event
);
10682 list_del_event(event
, ctx
);
10683 raw_spin_unlock_irq(&ctx
->lock
);
10688 * Free an unexposed, unused context as created by inheritance by
10689 * perf_event_init_task below, used by fork() in case of fail.
10691 * Not all locks are strictly required, but take them anyway to be nice and
10692 * help out with the lockdep assertions.
10694 void perf_event_free_task(struct task_struct
*task
)
10696 struct perf_event_context
*ctx
;
10697 struct perf_event
*event
, *tmp
;
10700 for_each_task_context_nr(ctxn
) {
10701 ctx
= task
->perf_event_ctxp
[ctxn
];
10705 mutex_lock(&ctx
->mutex
);
10706 raw_spin_lock_irq(&ctx
->lock
);
10708 * Destroy the task <-> ctx relation and mark the context dead.
10710 * This is important because even though the task hasn't been
10711 * exposed yet the context has been (through child_list).
10713 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10714 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10715 put_task_struct(task
); /* cannot be last */
10716 raw_spin_unlock_irq(&ctx
->lock
);
10718 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10719 perf_free_event(event
, ctx
);
10721 mutex_unlock(&ctx
->mutex
);
10726 void perf_event_delayed_put(struct task_struct
*task
)
10730 for_each_task_context_nr(ctxn
)
10731 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10734 struct file
*perf_event_get(unsigned int fd
)
10738 file
= fget_raw(fd
);
10740 return ERR_PTR(-EBADF
);
10742 if (file
->f_op
!= &perf_fops
) {
10744 return ERR_PTR(-EBADF
);
10750 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10753 return ERR_PTR(-EINVAL
);
10755 return &event
->attr
;
10759 * Inherit a event from parent task to child task.
10762 * - valid pointer on success
10763 * - NULL for orphaned events
10764 * - IS_ERR() on error
10766 static struct perf_event
*
10767 inherit_event(struct perf_event
*parent_event
,
10768 struct task_struct
*parent
,
10769 struct perf_event_context
*parent_ctx
,
10770 struct task_struct
*child
,
10771 struct perf_event
*group_leader
,
10772 struct perf_event_context
*child_ctx
)
10774 enum perf_event_state parent_state
= parent_event
->state
;
10775 struct perf_event
*child_event
;
10776 unsigned long flags
;
10779 * Instead of creating recursive hierarchies of events,
10780 * we link inherited events back to the original parent,
10781 * which has a filp for sure, which we use as the reference
10784 if (parent_event
->parent
)
10785 parent_event
= parent_event
->parent
;
10787 child_event
= perf_event_alloc(&parent_event
->attr
,
10790 group_leader
, parent_event
,
10792 if (IS_ERR(child_event
))
10793 return child_event
;
10796 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10797 * must be under the same lock in order to serialize against
10798 * perf_event_release_kernel(), such that either we must observe
10799 * is_orphaned_event() or they will observe us on the child_list.
10801 mutex_lock(&parent_event
->child_mutex
);
10802 if (is_orphaned_event(parent_event
) ||
10803 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10804 mutex_unlock(&parent_event
->child_mutex
);
10805 free_event(child_event
);
10809 get_ctx(child_ctx
);
10812 * Make the child state follow the state of the parent event,
10813 * not its attr.disabled bit. We hold the parent's mutex,
10814 * so we won't race with perf_event_{en, dis}able_family.
10816 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10817 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10819 child_event
->state
= PERF_EVENT_STATE_OFF
;
10821 if (parent_event
->attr
.freq
) {
10822 u64 sample_period
= parent_event
->hw
.sample_period
;
10823 struct hw_perf_event
*hwc
= &child_event
->hw
;
10825 hwc
->sample_period
= sample_period
;
10826 hwc
->last_period
= sample_period
;
10828 local64_set(&hwc
->period_left
, sample_period
);
10831 child_event
->ctx
= child_ctx
;
10832 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10833 child_event
->overflow_handler_context
10834 = parent_event
->overflow_handler_context
;
10837 * Precalculate sample_data sizes
10839 perf_event__header_size(child_event
);
10840 perf_event__id_header_size(child_event
);
10843 * Link it up in the child's context:
10845 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10846 add_event_to_ctx(child_event
, child_ctx
);
10847 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10850 * Link this into the parent event's child list
10852 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10853 mutex_unlock(&parent_event
->child_mutex
);
10855 return child_event
;
10859 * Inherits an event group.
10861 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10862 * This matches with perf_event_release_kernel() removing all child events.
10868 static int inherit_group(struct perf_event
*parent_event
,
10869 struct task_struct
*parent
,
10870 struct perf_event_context
*parent_ctx
,
10871 struct task_struct
*child
,
10872 struct perf_event_context
*child_ctx
)
10874 struct perf_event
*leader
;
10875 struct perf_event
*sub
;
10876 struct perf_event
*child_ctr
;
10878 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10879 child
, NULL
, child_ctx
);
10880 if (IS_ERR(leader
))
10881 return PTR_ERR(leader
);
10883 * @leader can be NULL here because of is_orphaned_event(). In this
10884 * case inherit_event() will create individual events, similar to what
10885 * perf_group_detach() would do anyway.
10887 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10888 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10889 child
, leader
, child_ctx
);
10890 if (IS_ERR(child_ctr
))
10891 return PTR_ERR(child_ctr
);
10897 * Creates the child task context and tries to inherit the event-group.
10899 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10900 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10901 * consistent with perf_event_release_kernel() removing all child events.
10908 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10909 struct perf_event_context
*parent_ctx
,
10910 struct task_struct
*child
, int ctxn
,
10911 int *inherited_all
)
10914 struct perf_event_context
*child_ctx
;
10916 if (!event
->attr
.inherit
) {
10917 *inherited_all
= 0;
10921 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10924 * This is executed from the parent task context, so
10925 * inherit events that have been marked for cloning.
10926 * First allocate and initialize a context for the
10929 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10933 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10936 ret
= inherit_group(event
, parent
, parent_ctx
,
10940 *inherited_all
= 0;
10946 * Initialize the perf_event context in task_struct
10948 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10950 struct perf_event_context
*child_ctx
, *parent_ctx
;
10951 struct perf_event_context
*cloned_ctx
;
10952 struct perf_event
*event
;
10953 struct task_struct
*parent
= current
;
10954 int inherited_all
= 1;
10955 unsigned long flags
;
10958 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10962 * If the parent's context is a clone, pin it so it won't get
10963 * swapped under us.
10965 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10970 * No need to check if parent_ctx != NULL here; since we saw
10971 * it non-NULL earlier, the only reason for it to become NULL
10972 * is if we exit, and since we're currently in the middle of
10973 * a fork we can't be exiting at the same time.
10977 * Lock the parent list. No need to lock the child - not PID
10978 * hashed yet and not running, so nobody can access it.
10980 mutex_lock(&parent_ctx
->mutex
);
10983 * We dont have to disable NMIs - we are only looking at
10984 * the list, not manipulating it:
10986 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10987 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10988 child
, ctxn
, &inherited_all
);
10994 * We can't hold ctx->lock when iterating the ->flexible_group list due
10995 * to allocations, but we need to prevent rotation because
10996 * rotate_ctx() will change the list from interrupt context.
10998 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10999 parent_ctx
->rotate_disable
= 1;
11000 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11002 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
11003 ret
= inherit_task_group(event
, parent
, parent_ctx
,
11004 child
, ctxn
, &inherited_all
);
11009 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11010 parent_ctx
->rotate_disable
= 0;
11012 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11014 if (child_ctx
&& inherited_all
) {
11016 * Mark the child context as a clone of the parent
11017 * context, or of whatever the parent is a clone of.
11019 * Note that if the parent is a clone, the holding of
11020 * parent_ctx->lock avoids it from being uncloned.
11022 cloned_ctx
= parent_ctx
->parent_ctx
;
11024 child_ctx
->parent_ctx
= cloned_ctx
;
11025 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
11027 child_ctx
->parent_ctx
= parent_ctx
;
11028 child_ctx
->parent_gen
= parent_ctx
->generation
;
11030 get_ctx(child_ctx
->parent_ctx
);
11033 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11035 mutex_unlock(&parent_ctx
->mutex
);
11037 perf_unpin_context(parent_ctx
);
11038 put_ctx(parent_ctx
);
11044 * Initialize the perf_event context in task_struct
11046 int perf_event_init_task(struct task_struct
*child
)
11050 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
11051 mutex_init(&child
->perf_event_mutex
);
11052 INIT_LIST_HEAD(&child
->perf_event_list
);
11054 for_each_task_context_nr(ctxn
) {
11055 ret
= perf_event_init_context(child
, ctxn
);
11057 perf_event_free_task(child
);
11065 static void __init
perf_event_init_all_cpus(void)
11067 struct swevent_htable
*swhash
;
11070 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
11072 for_each_possible_cpu(cpu
) {
11073 swhash
= &per_cpu(swevent_htable
, cpu
);
11074 mutex_init(&swhash
->hlist_mutex
);
11075 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11077 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11078 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11080 #ifdef CONFIG_CGROUP_PERF
11081 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11083 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11087 void perf_swevent_init_cpu(unsigned int cpu
)
11089 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11091 mutex_lock(&swhash
->hlist_mutex
);
11092 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11093 struct swevent_hlist
*hlist
;
11095 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11097 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11099 mutex_unlock(&swhash
->hlist_mutex
);
11102 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11103 static void __perf_event_exit_context(void *__info
)
11105 struct perf_event_context
*ctx
= __info
;
11106 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11107 struct perf_event
*event
;
11109 raw_spin_lock(&ctx
->lock
);
11110 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
11111 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11112 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11113 raw_spin_unlock(&ctx
->lock
);
11116 static void perf_event_exit_cpu_context(int cpu
)
11118 struct perf_cpu_context
*cpuctx
;
11119 struct perf_event_context
*ctx
;
11122 mutex_lock(&pmus_lock
);
11123 list_for_each_entry(pmu
, &pmus
, entry
) {
11124 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11125 ctx
= &cpuctx
->ctx
;
11127 mutex_lock(&ctx
->mutex
);
11128 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11129 cpuctx
->online
= 0;
11130 mutex_unlock(&ctx
->mutex
);
11132 cpumask_clear_cpu(cpu
, perf_online_mask
);
11133 mutex_unlock(&pmus_lock
);
11137 static void perf_event_exit_cpu_context(int cpu
) { }
11141 int perf_event_init_cpu(unsigned int cpu
)
11143 struct perf_cpu_context
*cpuctx
;
11144 struct perf_event_context
*ctx
;
11147 perf_swevent_init_cpu(cpu
);
11149 mutex_lock(&pmus_lock
);
11150 cpumask_set_cpu(cpu
, perf_online_mask
);
11151 list_for_each_entry(pmu
, &pmus
, entry
) {
11152 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11153 ctx
= &cpuctx
->ctx
;
11155 mutex_lock(&ctx
->mutex
);
11156 cpuctx
->online
= 1;
11157 mutex_unlock(&ctx
->mutex
);
11159 mutex_unlock(&pmus_lock
);
11164 int perf_event_exit_cpu(unsigned int cpu
)
11166 perf_event_exit_cpu_context(cpu
);
11171 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11175 for_each_online_cpu(cpu
)
11176 perf_event_exit_cpu(cpu
);
11182 * Run the perf reboot notifier at the very last possible moment so that
11183 * the generic watchdog code runs as long as possible.
11185 static struct notifier_block perf_reboot_notifier
= {
11186 .notifier_call
= perf_reboot
,
11187 .priority
= INT_MIN
,
11190 void __init
perf_event_init(void)
11194 idr_init(&pmu_idr
);
11196 perf_event_init_all_cpus();
11197 init_srcu_struct(&pmus_srcu
);
11198 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11199 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11200 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11201 perf_tp_register();
11202 perf_event_init_cpu(smp_processor_id());
11203 register_reboot_notifier(&perf_reboot_notifier
);
11205 ret
= init_hw_breakpoint();
11206 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11209 * Build time assertion that we keep the data_head at the intended
11210 * location. IOW, validation we got the __reserved[] size right.
11212 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11216 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11219 struct perf_pmu_events_attr
*pmu_attr
=
11220 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11222 if (pmu_attr
->event_str
)
11223 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11227 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11229 static int __init
perf_event_sysfs_init(void)
11234 mutex_lock(&pmus_lock
);
11236 ret
= bus_register(&pmu_bus
);
11240 list_for_each_entry(pmu
, &pmus
, entry
) {
11241 if (!pmu
->name
|| pmu
->type
< 0)
11244 ret
= pmu_dev_alloc(pmu
);
11245 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11247 pmu_bus_running
= 1;
11251 mutex_unlock(&pmus_lock
);
11255 device_initcall(perf_event_sysfs_init
);
11257 #ifdef CONFIG_CGROUP_PERF
11258 static struct cgroup_subsys_state
*
11259 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11261 struct perf_cgroup
*jc
;
11263 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11265 return ERR_PTR(-ENOMEM
);
11267 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11270 return ERR_PTR(-ENOMEM
);
11276 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11278 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11280 free_percpu(jc
->info
);
11284 static int __perf_cgroup_move(void *info
)
11286 struct task_struct
*task
= info
;
11288 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11293 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11295 struct task_struct
*task
;
11296 struct cgroup_subsys_state
*css
;
11298 cgroup_taskset_for_each(task
, css
, tset
)
11299 task_function_call(task
, __perf_cgroup_move
, task
);
11302 struct cgroup_subsys perf_event_cgrp_subsys
= {
11303 .css_alloc
= perf_cgroup_css_alloc
,
11304 .css_free
= perf_cgroup_css_free
,
11305 .attach
= perf_cgroup_attach
,
11307 * Implicitly enable on dfl hierarchy so that perf events can
11308 * always be filtered by cgroup2 path as long as perf_event
11309 * controller is not mounted on a legacy hierarchy.
11311 .implicit_on_dfl
= true,
11314 #endif /* CONFIG_CGROUP_PERF */