1 // SPDX-License-Identifier: GPL-2.0
3 * Performance events core code:
5 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
6 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
7 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
8 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <linux/idr.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/hash.h>
20 #include <linux/tick.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/hugetlb.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
53 #include <linux/min_heap.h>
54 #include <linux/highmem.h>
55 #include <linux/pgtable.h>
56 #include <linux/buildid.h>
60 #include <asm/irq_regs.h>
62 typedef int (*remote_function_f
)(void *);
64 struct remote_function_call
{
65 struct task_struct
*p
;
66 remote_function_f func
;
71 static void remote_function(void *data
)
73 struct remote_function_call
*tfc
= data
;
74 struct task_struct
*p
= tfc
->p
;
78 if (task_cpu(p
) != smp_processor_id())
82 * Now that we're on right CPU with IRQs disabled, we can test
83 * if we hit the right task without races.
86 tfc
->ret
= -ESRCH
; /* No such (running) process */
91 tfc
->ret
= tfc
->func(tfc
->info
);
95 * task_function_call - call a function on the cpu on which a task runs
96 * @p: the task to evaluate
97 * @func: the function to be called
98 * @info: the function call argument
100 * Calls the function @func when the task is currently running. This might
101 * be on the current CPU, which just calls the function directly. This will
102 * retry due to any failures in smp_call_function_single(), such as if the
103 * task_cpu() goes offline concurrently.
105 * returns @func return value or -ESRCH or -ENXIO when the process isn't running
108 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
110 struct remote_function_call data
= {
119 ret
= smp_call_function_single(task_cpu(p
), remote_function
,
134 * cpu_function_call - call a function on the cpu
135 * @cpu: target cpu to queue this function
136 * @func: the function to be called
137 * @info: the function call argument
139 * Calls the function @func on the remote cpu.
141 * returns: @func return value or -ENXIO when the cpu is offline
143 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
145 struct remote_function_call data
= {
149 .ret
= -ENXIO
, /* No such CPU */
152 smp_call_function_single(cpu
, remote_function
, &data
, 1);
157 static inline struct perf_cpu_context
*
158 __get_cpu_context(struct perf_event_context
*ctx
)
160 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
163 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
164 struct perf_event_context
*ctx
)
166 raw_spin_lock(&cpuctx
->ctx
.lock
);
168 raw_spin_lock(&ctx
->lock
);
171 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
172 struct perf_event_context
*ctx
)
175 raw_spin_unlock(&ctx
->lock
);
176 raw_spin_unlock(&cpuctx
->ctx
.lock
);
179 #define TASK_TOMBSTONE ((void *)-1L)
181 static bool is_kernel_event(struct perf_event
*event
)
183 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
187 * On task ctx scheduling...
189 * When !ctx->nr_events a task context will not be scheduled. This means
190 * we can disable the scheduler hooks (for performance) without leaving
191 * pending task ctx state.
193 * This however results in two special cases:
195 * - removing the last event from a task ctx; this is relatively straight
196 * forward and is done in __perf_remove_from_context.
198 * - adding the first event to a task ctx; this is tricky because we cannot
199 * rely on ctx->is_active and therefore cannot use event_function_call().
200 * See perf_install_in_context().
202 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
205 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
206 struct perf_event_context
*, void *);
208 struct event_function_struct
{
209 struct perf_event
*event
;
214 static int event_function(void *info
)
216 struct event_function_struct
*efs
= info
;
217 struct perf_event
*event
= efs
->event
;
218 struct perf_event_context
*ctx
= event
->ctx
;
219 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
220 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
223 lockdep_assert_irqs_disabled();
225 perf_ctx_lock(cpuctx
, task_ctx
);
227 * Since we do the IPI call without holding ctx->lock things can have
228 * changed, double check we hit the task we set out to hit.
231 if (ctx
->task
!= current
) {
237 * We only use event_function_call() on established contexts,
238 * and event_function() is only ever called when active (or
239 * rather, we'll have bailed in task_function_call() or the
240 * above ctx->task != current test), therefore we must have
241 * ctx->is_active here.
243 WARN_ON_ONCE(!ctx
->is_active
);
245 * And since we have ctx->is_active, cpuctx->task_ctx must
248 WARN_ON_ONCE(task_ctx
!= ctx
);
250 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
253 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
255 perf_ctx_unlock(cpuctx
, task_ctx
);
260 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
262 struct perf_event_context
*ctx
= event
->ctx
;
263 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
264 struct event_function_struct efs
= {
270 if (!event
->parent
) {
272 * If this is a !child event, we must hold ctx::mutex to
273 * stabilize the event->ctx relation. See
274 * perf_event_ctx_lock().
276 lockdep_assert_held(&ctx
->mutex
);
280 cpu_function_call(event
->cpu
, event_function
, &efs
);
284 if (task
== TASK_TOMBSTONE
)
288 if (!task_function_call(task
, event_function
, &efs
))
291 raw_spin_lock_irq(&ctx
->lock
);
293 * Reload the task pointer, it might have been changed by
294 * a concurrent perf_event_context_sched_out().
297 if (task
== TASK_TOMBSTONE
) {
298 raw_spin_unlock_irq(&ctx
->lock
);
301 if (ctx
->is_active
) {
302 raw_spin_unlock_irq(&ctx
->lock
);
305 func(event
, NULL
, ctx
, data
);
306 raw_spin_unlock_irq(&ctx
->lock
);
310 * Similar to event_function_call() + event_function(), but hard assumes IRQs
311 * are already disabled and we're on the right CPU.
313 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
315 struct perf_event_context
*ctx
= event
->ctx
;
316 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
317 struct task_struct
*task
= READ_ONCE(ctx
->task
);
318 struct perf_event_context
*task_ctx
= NULL
;
320 lockdep_assert_irqs_disabled();
323 if (task
== TASK_TOMBSTONE
)
329 perf_ctx_lock(cpuctx
, task_ctx
);
332 if (task
== TASK_TOMBSTONE
)
337 * We must be either inactive or active and the right task,
338 * otherwise we're screwed, since we cannot IPI to somewhere
341 if (ctx
->is_active
) {
342 if (WARN_ON_ONCE(task
!= current
))
345 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
349 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
352 func(event
, cpuctx
, ctx
, data
);
354 perf_ctx_unlock(cpuctx
, task_ctx
);
357 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
358 PERF_FLAG_FD_OUTPUT |\
359 PERF_FLAG_PID_CGROUP |\
360 PERF_FLAG_FD_CLOEXEC)
363 * branch priv levels that need permission checks
365 #define PERF_SAMPLE_BRANCH_PERM_PLM \
366 (PERF_SAMPLE_BRANCH_KERNEL |\
367 PERF_SAMPLE_BRANCH_HV)
370 EVENT_FLEXIBLE
= 0x1,
373 /* see ctx_resched() for details */
375 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
379 * perf_sched_events : >0 events exist
380 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
383 static void perf_sched_delayed(struct work_struct
*work
);
384 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
385 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
386 static DEFINE_MUTEX(perf_sched_mutex
);
387 static atomic_t perf_sched_count
;
389 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
390 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
391 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
393 static atomic_t nr_mmap_events __read_mostly
;
394 static atomic_t nr_comm_events __read_mostly
;
395 static atomic_t nr_namespaces_events __read_mostly
;
396 static atomic_t nr_task_events __read_mostly
;
397 static atomic_t nr_freq_events __read_mostly
;
398 static atomic_t nr_switch_events __read_mostly
;
399 static atomic_t nr_ksymbol_events __read_mostly
;
400 static atomic_t nr_bpf_events __read_mostly
;
401 static atomic_t nr_cgroup_events __read_mostly
;
402 static atomic_t nr_text_poke_events __read_mostly
;
403 static atomic_t nr_build_id_events __read_mostly
;
405 static LIST_HEAD(pmus
);
406 static DEFINE_MUTEX(pmus_lock
);
407 static struct srcu_struct pmus_srcu
;
408 static cpumask_var_t perf_online_mask
;
409 static struct kmem_cache
*perf_event_cache
;
412 * perf event paranoia level:
413 * -1 - not paranoid at all
414 * 0 - disallow raw tracepoint access for unpriv
415 * 1 - disallow cpu events for unpriv
416 * 2 - disallow kernel profiling for unpriv
418 int sysctl_perf_event_paranoid __read_mostly
= 2;
420 /* Minimum for 512 kiB + 1 user control page */
421 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
424 * max perf event sample rate
426 #define DEFAULT_MAX_SAMPLE_RATE 100000
427 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
428 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
430 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
432 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
433 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
435 static int perf_sample_allowed_ns __read_mostly
=
436 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
438 static void update_perf_cpu_limits(void)
440 u64 tmp
= perf_sample_period_ns
;
442 tmp
*= sysctl_perf_cpu_time_max_percent
;
443 tmp
= div_u64(tmp
, 100);
447 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
450 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
);
452 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
453 void *buffer
, size_t *lenp
, loff_t
*ppos
)
456 int perf_cpu
= sysctl_perf_cpu_time_max_percent
;
458 * If throttling is disabled don't allow the write:
460 if (write
&& (perf_cpu
== 100 || perf_cpu
== 0))
463 ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
467 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
468 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
469 update_perf_cpu_limits();
474 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
476 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
477 void *buffer
, size_t *lenp
, loff_t
*ppos
)
479 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
484 if (sysctl_perf_cpu_time_max_percent
== 100 ||
485 sysctl_perf_cpu_time_max_percent
== 0) {
487 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
488 WRITE_ONCE(perf_sample_allowed_ns
, 0);
490 update_perf_cpu_limits();
497 * perf samples are done in some very critical code paths (NMIs).
498 * If they take too much CPU time, the system can lock up and not
499 * get any real work done. This will drop the sample rate when
500 * we detect that events are taking too long.
502 #define NR_ACCUMULATED_SAMPLES 128
503 static DEFINE_PER_CPU(u64
, running_sample_length
);
505 static u64 __report_avg
;
506 static u64 __report_allowed
;
508 static void perf_duration_warn(struct irq_work
*w
)
510 printk_ratelimited(KERN_INFO
511 "perf: interrupt took too long (%lld > %lld), lowering "
512 "kernel.perf_event_max_sample_rate to %d\n",
513 __report_avg
, __report_allowed
,
514 sysctl_perf_event_sample_rate
);
517 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
519 void perf_sample_event_took(u64 sample_len_ns
)
521 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
529 /* Decay the counter by 1 average sample. */
530 running_len
= __this_cpu_read(running_sample_length
);
531 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
532 running_len
+= sample_len_ns
;
533 __this_cpu_write(running_sample_length
, running_len
);
536 * Note: this will be biased artifically low until we have
537 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
538 * from having to maintain a count.
540 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
541 if (avg_len
<= max_len
)
544 __report_avg
= avg_len
;
545 __report_allowed
= max_len
;
548 * Compute a throttle threshold 25% below the current duration.
550 avg_len
+= avg_len
/ 4;
551 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
557 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
558 WRITE_ONCE(max_samples_per_tick
, max
);
560 sysctl_perf_event_sample_rate
= max
* HZ
;
561 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
563 if (!irq_work_queue(&perf_duration_work
)) {
564 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
565 "kernel.perf_event_max_sample_rate to %d\n",
566 __report_avg
, __report_allowed
,
567 sysctl_perf_event_sample_rate
);
571 static atomic64_t perf_event_id
;
573 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
574 enum event_type_t event_type
);
576 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
577 enum event_type_t event_type
,
578 struct task_struct
*task
);
580 static void update_context_time(struct perf_event_context
*ctx
);
581 static u64
perf_event_time(struct perf_event
*event
);
583 void __weak
perf_event_print_debug(void) { }
585 static inline u64
perf_clock(void)
587 return local_clock();
590 static inline u64
perf_event_clock(struct perf_event
*event
)
592 return event
->clock();
596 * State based event timekeeping...
598 * The basic idea is to use event->state to determine which (if any) time
599 * fields to increment with the current delta. This means we only need to
600 * update timestamps when we change state or when they are explicitly requested
603 * Event groups make things a little more complicated, but not terribly so. The
604 * rules for a group are that if the group leader is OFF the entire group is
605 * OFF, irrespecive of what the group member states are. This results in
606 * __perf_effective_state().
608 * A futher ramification is that when a group leader flips between OFF and
609 * !OFF, we need to update all group member times.
612 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
613 * need to make sure the relevant context time is updated before we try and
614 * update our timestamps.
617 static __always_inline
enum perf_event_state
618 __perf_effective_state(struct perf_event
*event
)
620 struct perf_event
*leader
= event
->group_leader
;
622 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
623 return leader
->state
;
628 static __always_inline
void
629 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
631 enum perf_event_state state
= __perf_effective_state(event
);
632 u64 delta
= now
- event
->tstamp
;
634 *enabled
= event
->total_time_enabled
;
635 if (state
>= PERF_EVENT_STATE_INACTIVE
)
638 *running
= event
->total_time_running
;
639 if (state
>= PERF_EVENT_STATE_ACTIVE
)
643 static void perf_event_update_time(struct perf_event
*event
)
645 u64 now
= perf_event_time(event
);
647 __perf_update_times(event
, now
, &event
->total_time_enabled
,
648 &event
->total_time_running
);
652 static void perf_event_update_sibling_time(struct perf_event
*leader
)
654 struct perf_event
*sibling
;
656 for_each_sibling_event(sibling
, leader
)
657 perf_event_update_time(sibling
);
661 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
663 if (event
->state
== state
)
666 perf_event_update_time(event
);
668 * If a group leader gets enabled/disabled all its siblings
671 if ((event
->state
< 0) ^ (state
< 0))
672 perf_event_update_sibling_time(event
);
674 WRITE_ONCE(event
->state
, state
);
677 #ifdef CONFIG_CGROUP_PERF
680 perf_cgroup_match(struct perf_event
*event
)
682 struct perf_event_context
*ctx
= event
->ctx
;
683 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
685 /* @event doesn't care about cgroup */
689 /* wants specific cgroup scope but @cpuctx isn't associated with any */
694 * Cgroup scoping is recursive. An event enabled for a cgroup is
695 * also enabled for all its descendant cgroups. If @cpuctx's
696 * cgroup is a descendant of @event's (the test covers identity
697 * case), it's a match.
699 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
700 event
->cgrp
->css
.cgroup
);
703 static inline void perf_detach_cgroup(struct perf_event
*event
)
705 css_put(&event
->cgrp
->css
);
709 static inline int is_cgroup_event(struct perf_event
*event
)
711 return event
->cgrp
!= NULL
;
714 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
716 struct perf_cgroup_info
*t
;
718 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
722 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
724 struct perf_cgroup_info
*info
;
729 info
= this_cpu_ptr(cgrp
->info
);
731 info
->time
+= now
- info
->timestamp
;
732 info
->timestamp
= now
;
735 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
737 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
738 struct cgroup_subsys_state
*css
;
741 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
742 cgrp
= container_of(css
, struct perf_cgroup
, css
);
743 __update_cgrp_time(cgrp
);
748 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
750 struct perf_cgroup
*cgrp
;
753 * ensure we access cgroup data only when needed and
754 * when we know the cgroup is pinned (css_get)
756 if (!is_cgroup_event(event
))
759 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
761 * Do not update time when cgroup is not active
763 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
764 __update_cgrp_time(event
->cgrp
);
768 perf_cgroup_set_timestamp(struct task_struct
*task
,
769 struct perf_event_context
*ctx
)
771 struct perf_cgroup
*cgrp
;
772 struct perf_cgroup_info
*info
;
773 struct cgroup_subsys_state
*css
;
776 * ctx->lock held by caller
777 * ensure we do not access cgroup data
778 * unless we have the cgroup pinned (css_get)
780 if (!task
|| !ctx
->nr_cgroups
)
783 cgrp
= perf_cgroup_from_task(task
, ctx
);
785 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
786 cgrp
= container_of(css
, struct perf_cgroup
, css
);
787 info
= this_cpu_ptr(cgrp
->info
);
788 info
->timestamp
= ctx
->timestamp
;
792 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
794 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
795 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
798 * reschedule events based on the cgroup constraint of task.
800 * mode SWOUT : schedule out everything
801 * mode SWIN : schedule in based on cgroup for next
803 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
805 struct perf_cpu_context
*cpuctx
;
806 struct list_head
*list
;
810 * Disable interrupts and preemption to avoid this CPU's
811 * cgrp_cpuctx_entry to change under us.
813 local_irq_save(flags
);
815 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
816 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
817 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
819 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
820 perf_pmu_disable(cpuctx
->ctx
.pmu
);
822 if (mode
& PERF_CGROUP_SWOUT
) {
823 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
825 * must not be done before ctxswout due
826 * to event_filter_match() in event_sched_out()
831 if (mode
& PERF_CGROUP_SWIN
) {
832 WARN_ON_ONCE(cpuctx
->cgrp
);
834 * set cgrp before ctxsw in to allow
835 * event_filter_match() to not have to pass
837 * we pass the cpuctx->ctx to perf_cgroup_from_task()
838 * because cgorup events are only per-cpu
840 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
842 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
844 perf_pmu_enable(cpuctx
->ctx
.pmu
);
845 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
848 local_irq_restore(flags
);
851 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
852 struct task_struct
*next
)
854 struct perf_cgroup
*cgrp1
;
855 struct perf_cgroup
*cgrp2
= NULL
;
859 * we come here when we know perf_cgroup_events > 0
860 * we do not need to pass the ctx here because we know
861 * we are holding the rcu lock
863 cgrp1
= perf_cgroup_from_task(task
, NULL
);
864 cgrp2
= perf_cgroup_from_task(next
, NULL
);
867 * only schedule out current cgroup events if we know
868 * that we are switching to a different cgroup. Otherwise,
869 * do no touch the cgroup events.
872 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
877 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
878 struct task_struct
*task
)
880 struct perf_cgroup
*cgrp1
;
881 struct perf_cgroup
*cgrp2
= NULL
;
885 * we come here when we know perf_cgroup_events > 0
886 * we do not need to pass the ctx here because we know
887 * we are holding the rcu lock
889 cgrp1
= perf_cgroup_from_task(task
, NULL
);
890 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
893 * only need to schedule in cgroup events if we are changing
894 * cgroup during ctxsw. Cgroup events were not scheduled
895 * out of ctxsw out if that was not the case.
898 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
903 static int perf_cgroup_ensure_storage(struct perf_event
*event
,
904 struct cgroup_subsys_state
*css
)
906 struct perf_cpu_context
*cpuctx
;
907 struct perf_event
**storage
;
908 int cpu
, heap_size
, ret
= 0;
911 * Allow storage to have sufficent space for an iterator for each
912 * possibly nested cgroup plus an iterator for events with no cgroup.
914 for (heap_size
= 1; css
; css
= css
->parent
)
917 for_each_possible_cpu(cpu
) {
918 cpuctx
= per_cpu_ptr(event
->pmu
->pmu_cpu_context
, cpu
);
919 if (heap_size
<= cpuctx
->heap_size
)
922 storage
= kmalloc_node(heap_size
* sizeof(struct perf_event
*),
923 GFP_KERNEL
, cpu_to_node(cpu
));
929 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
930 if (cpuctx
->heap_size
< heap_size
) {
931 swap(cpuctx
->heap
, storage
);
932 if (storage
== cpuctx
->heap_default
)
934 cpuctx
->heap_size
= heap_size
;
936 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
944 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
945 struct perf_event_attr
*attr
,
946 struct perf_event
*group_leader
)
948 struct perf_cgroup
*cgrp
;
949 struct cgroup_subsys_state
*css
;
950 struct fd f
= fdget(fd
);
956 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
957 &perf_event_cgrp_subsys
);
963 ret
= perf_cgroup_ensure_storage(event
, css
);
967 cgrp
= container_of(css
, struct perf_cgroup
, css
);
971 * all events in a group must monitor
972 * the same cgroup because a task belongs
973 * to only one perf cgroup at a time
975 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
976 perf_detach_cgroup(event
);
985 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
987 struct perf_cgroup_info
*t
;
988 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
989 event
->shadow_ctx_time
= now
- t
->timestamp
;
993 perf_cgroup_event_enable(struct perf_event
*event
, struct perf_event_context
*ctx
)
995 struct perf_cpu_context
*cpuctx
;
997 if (!is_cgroup_event(event
))
1001 * Because cgroup events are always per-cpu events,
1002 * @ctx == &cpuctx->ctx.
1004 cpuctx
= container_of(ctx
, struct perf_cpu_context
, ctx
);
1007 * Since setting cpuctx->cgrp is conditional on the current @cgrp
1008 * matching the event's cgroup, we must do this for every new event,
1009 * because if the first would mismatch, the second would not try again
1010 * and we would leave cpuctx->cgrp unset.
1012 if (ctx
->is_active
&& !cpuctx
->cgrp
) {
1013 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
1015 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
1016 cpuctx
->cgrp
= cgrp
;
1019 if (ctx
->nr_cgroups
++)
1022 list_add(&cpuctx
->cgrp_cpuctx_entry
,
1023 per_cpu_ptr(&cgrp_cpuctx_list
, event
->cpu
));
1027 perf_cgroup_event_disable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1029 struct perf_cpu_context
*cpuctx
;
1031 if (!is_cgroup_event(event
))
1035 * Because cgroup events are always per-cpu events,
1036 * @ctx == &cpuctx->ctx.
1038 cpuctx
= container_of(ctx
, struct perf_cpu_context
, ctx
);
1040 if (--ctx
->nr_cgroups
)
1043 if (ctx
->is_active
&& cpuctx
->cgrp
)
1044 cpuctx
->cgrp
= NULL
;
1046 list_del(&cpuctx
->cgrp_cpuctx_entry
);
1049 #else /* !CONFIG_CGROUP_PERF */
1052 perf_cgroup_match(struct perf_event
*event
)
1057 static inline void perf_detach_cgroup(struct perf_event
*event
)
1060 static inline int is_cgroup_event(struct perf_event
*event
)
1065 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1069 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1073 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1074 struct task_struct
*next
)
1078 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1079 struct task_struct
*task
)
1083 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1084 struct perf_event_attr
*attr
,
1085 struct perf_event
*group_leader
)
1091 perf_cgroup_set_timestamp(struct task_struct
*task
,
1092 struct perf_event_context
*ctx
)
1097 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1102 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1106 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1112 perf_cgroup_event_enable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1117 perf_cgroup_event_disable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1123 * set default to be dependent on timer tick just
1124 * like original code
1126 #define PERF_CPU_HRTIMER (1000 / HZ)
1128 * function must be called with interrupts disabled
1130 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1132 struct perf_cpu_context
*cpuctx
;
1135 lockdep_assert_irqs_disabled();
1137 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1138 rotations
= perf_rotate_context(cpuctx
);
1140 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1142 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1144 cpuctx
->hrtimer_active
= 0;
1145 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1147 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1150 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1152 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1153 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1156 /* no multiplexing needed for SW PMU */
1157 if (pmu
->task_ctx_nr
== perf_sw_context
)
1161 * check default is sane, if not set then force to
1162 * default interval (1/tick)
1164 interval
= pmu
->hrtimer_interval_ms
;
1166 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1168 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1170 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1171 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED_HARD
);
1172 timer
->function
= perf_mux_hrtimer_handler
;
1175 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1177 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1178 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1179 unsigned long flags
;
1181 /* not for SW PMU */
1182 if (pmu
->task_ctx_nr
== perf_sw_context
)
1185 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1186 if (!cpuctx
->hrtimer_active
) {
1187 cpuctx
->hrtimer_active
= 1;
1188 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1189 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED_HARD
);
1191 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1196 void perf_pmu_disable(struct pmu
*pmu
)
1198 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1200 pmu
->pmu_disable(pmu
);
1203 void perf_pmu_enable(struct pmu
*pmu
)
1205 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1207 pmu
->pmu_enable(pmu
);
1210 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1213 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1214 * perf_event_task_tick() are fully serialized because they're strictly cpu
1215 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1216 * disabled, while perf_event_task_tick is called from IRQ context.
1218 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1220 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1222 lockdep_assert_irqs_disabled();
1224 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1226 list_add(&ctx
->active_ctx_list
, head
);
1229 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1231 lockdep_assert_irqs_disabled();
1233 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1235 list_del_init(&ctx
->active_ctx_list
);
1238 static void get_ctx(struct perf_event_context
*ctx
)
1240 refcount_inc(&ctx
->refcount
);
1243 static void *alloc_task_ctx_data(struct pmu
*pmu
)
1245 if (pmu
->task_ctx_cache
)
1246 return kmem_cache_zalloc(pmu
->task_ctx_cache
, GFP_KERNEL
);
1251 static void free_task_ctx_data(struct pmu
*pmu
, void *task_ctx_data
)
1253 if (pmu
->task_ctx_cache
&& task_ctx_data
)
1254 kmem_cache_free(pmu
->task_ctx_cache
, task_ctx_data
);
1257 static void free_ctx(struct rcu_head
*head
)
1259 struct perf_event_context
*ctx
;
1261 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1262 free_task_ctx_data(ctx
->pmu
, ctx
->task_ctx_data
);
1266 static void put_ctx(struct perf_event_context
*ctx
)
1268 if (refcount_dec_and_test(&ctx
->refcount
)) {
1269 if (ctx
->parent_ctx
)
1270 put_ctx(ctx
->parent_ctx
);
1271 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1272 put_task_struct(ctx
->task
);
1273 call_rcu(&ctx
->rcu_head
, free_ctx
);
1278 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1279 * perf_pmu_migrate_context() we need some magic.
1281 * Those places that change perf_event::ctx will hold both
1282 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1284 * Lock ordering is by mutex address. There are two other sites where
1285 * perf_event_context::mutex nests and those are:
1287 * - perf_event_exit_task_context() [ child , 0 ]
1288 * perf_event_exit_event()
1289 * put_event() [ parent, 1 ]
1291 * - perf_event_init_context() [ parent, 0 ]
1292 * inherit_task_group()
1295 * perf_event_alloc()
1297 * perf_try_init_event() [ child , 1 ]
1299 * While it appears there is an obvious deadlock here -- the parent and child
1300 * nesting levels are inverted between the two. This is in fact safe because
1301 * life-time rules separate them. That is an exiting task cannot fork, and a
1302 * spawning task cannot (yet) exit.
1304 * But remember that these are parent<->child context relations, and
1305 * migration does not affect children, therefore these two orderings should not
1308 * The change in perf_event::ctx does not affect children (as claimed above)
1309 * because the sys_perf_event_open() case will install a new event and break
1310 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1311 * concerned with cpuctx and that doesn't have children.
1313 * The places that change perf_event::ctx will issue:
1315 * perf_remove_from_context();
1316 * synchronize_rcu();
1317 * perf_install_in_context();
1319 * to affect the change. The remove_from_context() + synchronize_rcu() should
1320 * quiesce the event, after which we can install it in the new location. This
1321 * means that only external vectors (perf_fops, prctl) can perturb the event
1322 * while in transit. Therefore all such accessors should also acquire
1323 * perf_event_context::mutex to serialize against this.
1325 * However; because event->ctx can change while we're waiting to acquire
1326 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1331 * task_struct::perf_event_mutex
1332 * perf_event_context::mutex
1333 * perf_event::child_mutex;
1334 * perf_event_context::lock
1335 * perf_event::mmap_mutex
1337 * perf_addr_filters_head::lock
1341 * cpuctx->mutex / perf_event_context::mutex
1343 static struct perf_event_context
*
1344 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1346 struct perf_event_context
*ctx
;
1350 ctx
= READ_ONCE(event
->ctx
);
1351 if (!refcount_inc_not_zero(&ctx
->refcount
)) {
1357 mutex_lock_nested(&ctx
->mutex
, nesting
);
1358 if (event
->ctx
!= ctx
) {
1359 mutex_unlock(&ctx
->mutex
);
1367 static inline struct perf_event_context
*
1368 perf_event_ctx_lock(struct perf_event
*event
)
1370 return perf_event_ctx_lock_nested(event
, 0);
1373 static void perf_event_ctx_unlock(struct perf_event
*event
,
1374 struct perf_event_context
*ctx
)
1376 mutex_unlock(&ctx
->mutex
);
1381 * This must be done under the ctx->lock, such as to serialize against
1382 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1383 * calling scheduler related locks and ctx->lock nests inside those.
1385 static __must_check
struct perf_event_context
*
1386 unclone_ctx(struct perf_event_context
*ctx
)
1388 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1390 lockdep_assert_held(&ctx
->lock
);
1393 ctx
->parent_ctx
= NULL
;
1399 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1404 * only top level events have the pid namespace they were created in
1407 event
= event
->parent
;
1409 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1410 /* avoid -1 if it is idle thread or runs in another ns */
1411 if (!nr
&& !pid_alive(p
))
1416 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1418 return perf_event_pid_type(event
, p
, PIDTYPE_TGID
);
1421 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1423 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1427 * If we inherit events we want to return the parent event id
1430 static u64
primary_event_id(struct perf_event
*event
)
1435 id
= event
->parent
->id
;
1441 * Get the perf_event_context for a task and lock it.
1443 * This has to cope with the fact that until it is locked,
1444 * the context could get moved to another task.
1446 static struct perf_event_context
*
1447 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1449 struct perf_event_context
*ctx
;
1453 * One of the few rules of preemptible RCU is that one cannot do
1454 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1455 * part of the read side critical section was irqs-enabled -- see
1456 * rcu_read_unlock_special().
1458 * Since ctx->lock nests under rq->lock we must ensure the entire read
1459 * side critical section has interrupts disabled.
1461 local_irq_save(*flags
);
1463 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1466 * If this context is a clone of another, it might
1467 * get swapped for another underneath us by
1468 * perf_event_task_sched_out, though the
1469 * rcu_read_lock() protects us from any context
1470 * getting freed. Lock the context and check if it
1471 * got swapped before we could get the lock, and retry
1472 * if so. If we locked the right context, then it
1473 * can't get swapped on us any more.
1475 raw_spin_lock(&ctx
->lock
);
1476 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1477 raw_spin_unlock(&ctx
->lock
);
1479 local_irq_restore(*flags
);
1483 if (ctx
->task
== TASK_TOMBSTONE
||
1484 !refcount_inc_not_zero(&ctx
->refcount
)) {
1485 raw_spin_unlock(&ctx
->lock
);
1488 WARN_ON_ONCE(ctx
->task
!= task
);
1493 local_irq_restore(*flags
);
1498 * Get the context for a task and increment its pin_count so it
1499 * can't get swapped to another task. This also increments its
1500 * reference count so that the context can't get freed.
1502 static struct perf_event_context
*
1503 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1505 struct perf_event_context
*ctx
;
1506 unsigned long flags
;
1508 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1511 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1516 static void perf_unpin_context(struct perf_event_context
*ctx
)
1518 unsigned long flags
;
1520 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1522 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1526 * Update the record of the current time in a context.
1528 static void update_context_time(struct perf_event_context
*ctx
)
1530 u64 now
= perf_clock();
1532 ctx
->time
+= now
- ctx
->timestamp
;
1533 ctx
->timestamp
= now
;
1536 static u64
perf_event_time(struct perf_event
*event
)
1538 struct perf_event_context
*ctx
= event
->ctx
;
1540 if (is_cgroup_event(event
))
1541 return perf_cgroup_event_time(event
);
1543 return ctx
? ctx
->time
: 0;
1546 static enum event_type_t
get_event_type(struct perf_event
*event
)
1548 struct perf_event_context
*ctx
= event
->ctx
;
1549 enum event_type_t event_type
;
1551 lockdep_assert_held(&ctx
->lock
);
1554 * It's 'group type', really, because if our group leader is
1555 * pinned, so are we.
1557 if (event
->group_leader
!= event
)
1558 event
= event
->group_leader
;
1560 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1562 event_type
|= EVENT_CPU
;
1568 * Helper function to initialize event group nodes.
1570 static void init_event_group(struct perf_event
*event
)
1572 RB_CLEAR_NODE(&event
->group_node
);
1573 event
->group_index
= 0;
1577 * Extract pinned or flexible groups from the context
1578 * based on event attrs bits.
1580 static struct perf_event_groups
*
1581 get_event_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1583 if (event
->attr
.pinned
)
1584 return &ctx
->pinned_groups
;
1586 return &ctx
->flexible_groups
;
1590 * Helper function to initializes perf_event_group trees.
1592 static void perf_event_groups_init(struct perf_event_groups
*groups
)
1594 groups
->tree
= RB_ROOT
;
1598 static inline struct cgroup
*event_cgroup(const struct perf_event
*event
)
1600 struct cgroup
*cgroup
= NULL
;
1602 #ifdef CONFIG_CGROUP_PERF
1604 cgroup
= event
->cgrp
->css
.cgroup
;
1611 * Compare function for event groups;
1613 * Implements complex key that first sorts by CPU and then by virtual index
1614 * which provides ordering when rotating groups for the same CPU.
1616 static __always_inline
int
1617 perf_event_groups_cmp(const int left_cpu
, const struct cgroup
*left_cgroup
,
1618 const u64 left_group_index
, const struct perf_event
*right
)
1620 if (left_cpu
< right
->cpu
)
1622 if (left_cpu
> right
->cpu
)
1625 #ifdef CONFIG_CGROUP_PERF
1627 const struct cgroup
*right_cgroup
= event_cgroup(right
);
1629 if (left_cgroup
!= right_cgroup
) {
1632 * Left has no cgroup but right does, no
1633 * cgroups come first.
1637 if (!right_cgroup
) {
1639 * Right has no cgroup but left does, no
1640 * cgroups come first.
1644 /* Two dissimilar cgroups, order by id. */
1645 if (cgroup_id(left_cgroup
) < cgroup_id(right_cgroup
))
1653 if (left_group_index
< right
->group_index
)
1655 if (left_group_index
> right
->group_index
)
1661 #define __node_2_pe(node) \
1662 rb_entry((node), struct perf_event, group_node)
1664 static inline bool __group_less(struct rb_node
*a
, const struct rb_node
*b
)
1666 struct perf_event
*e
= __node_2_pe(a
);
1667 return perf_event_groups_cmp(e
->cpu
, event_cgroup(e
), e
->group_index
,
1668 __node_2_pe(b
)) < 0;
1671 struct __group_key
{
1673 struct cgroup
*cgroup
;
1676 static inline int __group_cmp(const void *key
, const struct rb_node
*node
)
1678 const struct __group_key
*a
= key
;
1679 const struct perf_event
*b
= __node_2_pe(node
);
1681 /* partial/subtree match: @cpu, @cgroup; ignore: @group_index */
1682 return perf_event_groups_cmp(a
->cpu
, a
->cgroup
, b
->group_index
, b
);
1686 * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
1687 * key (see perf_event_groups_less). This places it last inside the CPU
1691 perf_event_groups_insert(struct perf_event_groups
*groups
,
1692 struct perf_event
*event
)
1694 event
->group_index
= ++groups
->index
;
1696 rb_add(&event
->group_node
, &groups
->tree
, __group_less
);
1700 * Helper function to insert event into the pinned or flexible groups.
1703 add_event_to_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1705 struct perf_event_groups
*groups
;
1707 groups
= get_event_groups(event
, ctx
);
1708 perf_event_groups_insert(groups
, event
);
1712 * Delete a group from a tree.
1715 perf_event_groups_delete(struct perf_event_groups
*groups
,
1716 struct perf_event
*event
)
1718 WARN_ON_ONCE(RB_EMPTY_NODE(&event
->group_node
) ||
1719 RB_EMPTY_ROOT(&groups
->tree
));
1721 rb_erase(&event
->group_node
, &groups
->tree
);
1722 init_event_group(event
);
1726 * Helper function to delete event from its groups.
1729 del_event_from_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1731 struct perf_event_groups
*groups
;
1733 groups
= get_event_groups(event
, ctx
);
1734 perf_event_groups_delete(groups
, event
);
1738 * Get the leftmost event in the cpu/cgroup subtree.
1740 static struct perf_event
*
1741 perf_event_groups_first(struct perf_event_groups
*groups
, int cpu
,
1742 struct cgroup
*cgrp
)
1744 struct __group_key key
= {
1748 struct rb_node
*node
;
1750 node
= rb_find_first(&key
, &groups
->tree
, __group_cmp
);
1752 return __node_2_pe(node
);
1758 * Like rb_entry_next_safe() for the @cpu subtree.
1760 static struct perf_event
*
1761 perf_event_groups_next(struct perf_event
*event
)
1763 struct __group_key key
= {
1765 .cgroup
= event_cgroup(event
),
1767 struct rb_node
*next
;
1769 next
= rb_next_match(&key
, &event
->group_node
, __group_cmp
);
1771 return __node_2_pe(next
);
1777 * Iterate through the whole groups tree.
1779 #define perf_event_groups_for_each(event, groups) \
1780 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1781 typeof(*event), group_node); event; \
1782 event = rb_entry_safe(rb_next(&event->group_node), \
1783 typeof(*event), group_node))
1786 * Add an event from the lists for its context.
1787 * Must be called with ctx->mutex and ctx->lock held.
1790 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1792 lockdep_assert_held(&ctx
->lock
);
1794 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1795 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1797 event
->tstamp
= perf_event_time(event
);
1800 * If we're a stand alone event or group leader, we go to the context
1801 * list, group events are kept attached to the group so that
1802 * perf_group_detach can, at all times, locate all siblings.
1804 if (event
->group_leader
== event
) {
1805 event
->group_caps
= event
->event_caps
;
1806 add_event_to_groups(event
, ctx
);
1809 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1811 if (event
->attr
.inherit_stat
)
1814 if (event
->state
> PERF_EVENT_STATE_OFF
)
1815 perf_cgroup_event_enable(event
, ctx
);
1821 * Initialize event state based on the perf_event_attr::disabled.
1823 static inline void perf_event__state_init(struct perf_event
*event
)
1825 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1826 PERF_EVENT_STATE_INACTIVE
;
1829 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1831 int entry
= sizeof(u64
); /* value */
1835 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1836 size
+= sizeof(u64
);
1838 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1839 size
+= sizeof(u64
);
1841 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1842 entry
+= sizeof(u64
);
1844 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1846 size
+= sizeof(u64
);
1850 event
->read_size
= size
;
1853 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1855 struct perf_sample_data
*data
;
1858 if (sample_type
& PERF_SAMPLE_IP
)
1859 size
+= sizeof(data
->ip
);
1861 if (sample_type
& PERF_SAMPLE_ADDR
)
1862 size
+= sizeof(data
->addr
);
1864 if (sample_type
& PERF_SAMPLE_PERIOD
)
1865 size
+= sizeof(data
->period
);
1867 if (sample_type
& PERF_SAMPLE_WEIGHT_TYPE
)
1868 size
+= sizeof(data
->weight
.full
);
1870 if (sample_type
& PERF_SAMPLE_READ
)
1871 size
+= event
->read_size
;
1873 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1874 size
+= sizeof(data
->data_src
.val
);
1876 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1877 size
+= sizeof(data
->txn
);
1879 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1880 size
+= sizeof(data
->phys_addr
);
1882 if (sample_type
& PERF_SAMPLE_CGROUP
)
1883 size
+= sizeof(data
->cgroup
);
1885 if (sample_type
& PERF_SAMPLE_DATA_PAGE_SIZE
)
1886 size
+= sizeof(data
->data_page_size
);
1888 if (sample_type
& PERF_SAMPLE_CODE_PAGE_SIZE
)
1889 size
+= sizeof(data
->code_page_size
);
1891 event
->header_size
= size
;
1895 * Called at perf_event creation and when events are attached/detached from a
1898 static void perf_event__header_size(struct perf_event
*event
)
1900 __perf_event_read_size(event
,
1901 event
->group_leader
->nr_siblings
);
1902 __perf_event_header_size(event
, event
->attr
.sample_type
);
1905 static void perf_event__id_header_size(struct perf_event
*event
)
1907 struct perf_sample_data
*data
;
1908 u64 sample_type
= event
->attr
.sample_type
;
1911 if (sample_type
& PERF_SAMPLE_TID
)
1912 size
+= sizeof(data
->tid_entry
);
1914 if (sample_type
& PERF_SAMPLE_TIME
)
1915 size
+= sizeof(data
->time
);
1917 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1918 size
+= sizeof(data
->id
);
1920 if (sample_type
& PERF_SAMPLE_ID
)
1921 size
+= sizeof(data
->id
);
1923 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1924 size
+= sizeof(data
->stream_id
);
1926 if (sample_type
& PERF_SAMPLE_CPU
)
1927 size
+= sizeof(data
->cpu_entry
);
1929 event
->id_header_size
= size
;
1932 static bool perf_event_validate_size(struct perf_event
*event
)
1935 * The values computed here will be over-written when we actually
1938 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1939 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1940 perf_event__id_header_size(event
);
1943 * Sum the lot; should not exceed the 64k limit we have on records.
1944 * Conservative limit to allow for callchains and other variable fields.
1946 if (event
->read_size
+ event
->header_size
+
1947 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1953 static void perf_group_attach(struct perf_event
*event
)
1955 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1957 lockdep_assert_held(&event
->ctx
->lock
);
1960 * We can have double attach due to group movement in perf_event_open.
1962 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1965 event
->attach_state
|= PERF_ATTACH_GROUP
;
1967 if (group_leader
== event
)
1970 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1972 group_leader
->group_caps
&= event
->event_caps
;
1974 list_add_tail(&event
->sibling_list
, &group_leader
->sibling_list
);
1975 group_leader
->nr_siblings
++;
1977 perf_event__header_size(group_leader
);
1979 for_each_sibling_event(pos
, group_leader
)
1980 perf_event__header_size(pos
);
1984 * Remove an event from the lists for its context.
1985 * Must be called with ctx->mutex and ctx->lock held.
1988 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1990 WARN_ON_ONCE(event
->ctx
!= ctx
);
1991 lockdep_assert_held(&ctx
->lock
);
1994 * We can have double detach due to exit/hot-unplug + close.
1996 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1999 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
2002 if (event
->attr
.inherit_stat
)
2005 list_del_rcu(&event
->event_entry
);
2007 if (event
->group_leader
== event
)
2008 del_event_from_groups(event
, ctx
);
2011 * If event was in error state, then keep it
2012 * that way, otherwise bogus counts will be
2013 * returned on read(). The only way to get out
2014 * of error state is by explicit re-enabling
2017 if (event
->state
> PERF_EVENT_STATE_OFF
) {
2018 perf_cgroup_event_disable(event
, ctx
);
2019 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2026 perf_aux_output_match(struct perf_event
*event
, struct perf_event
*aux_event
)
2028 if (!has_aux(aux_event
))
2031 if (!event
->pmu
->aux_output_match
)
2034 return event
->pmu
->aux_output_match(aux_event
);
2037 static void put_event(struct perf_event
*event
);
2038 static void event_sched_out(struct perf_event
*event
,
2039 struct perf_cpu_context
*cpuctx
,
2040 struct perf_event_context
*ctx
);
2042 static void perf_put_aux_event(struct perf_event
*event
)
2044 struct perf_event_context
*ctx
= event
->ctx
;
2045 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2046 struct perf_event
*iter
;
2049 * If event uses aux_event tear down the link
2051 if (event
->aux_event
) {
2052 iter
= event
->aux_event
;
2053 event
->aux_event
= NULL
;
2059 * If the event is an aux_event, tear down all links to
2060 * it from other events.
2062 for_each_sibling_event(iter
, event
->group_leader
) {
2063 if (iter
->aux_event
!= event
)
2066 iter
->aux_event
= NULL
;
2070 * If it's ACTIVE, schedule it out and put it into ERROR
2071 * state so that we don't try to schedule it again. Note
2072 * that perf_event_enable() will clear the ERROR status.
2074 event_sched_out(iter
, cpuctx
, ctx
);
2075 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
2079 static bool perf_need_aux_event(struct perf_event
*event
)
2081 return !!event
->attr
.aux_output
|| !!event
->attr
.aux_sample_size
;
2084 static int perf_get_aux_event(struct perf_event
*event
,
2085 struct perf_event
*group_leader
)
2088 * Our group leader must be an aux event if we want to be
2089 * an aux_output. This way, the aux event will precede its
2090 * aux_output events in the group, and therefore will always
2097 * aux_output and aux_sample_size are mutually exclusive.
2099 if (event
->attr
.aux_output
&& event
->attr
.aux_sample_size
)
2102 if (event
->attr
.aux_output
&&
2103 !perf_aux_output_match(event
, group_leader
))
2106 if (event
->attr
.aux_sample_size
&& !group_leader
->pmu
->snapshot_aux
)
2109 if (!atomic_long_inc_not_zero(&group_leader
->refcount
))
2113 * Link aux_outputs to their aux event; this is undone in
2114 * perf_group_detach() by perf_put_aux_event(). When the
2115 * group in torn down, the aux_output events loose their
2116 * link to the aux_event and can't schedule any more.
2118 event
->aux_event
= group_leader
;
2123 static inline struct list_head
*get_event_list(struct perf_event
*event
)
2125 struct perf_event_context
*ctx
= event
->ctx
;
2126 return event
->attr
.pinned
? &ctx
->pinned_active
: &ctx
->flexible_active
;
2130 * Events that have PERF_EV_CAP_SIBLING require being part of a group and
2131 * cannot exist on their own, schedule them out and move them into the ERROR
2132 * state. Also see _perf_event_enable(), it will not be able to recover
2135 static inline void perf_remove_sibling_event(struct perf_event
*event
)
2137 struct perf_event_context
*ctx
= event
->ctx
;
2138 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2140 event_sched_out(event
, cpuctx
, ctx
);
2141 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
2144 static void perf_group_detach(struct perf_event
*event
)
2146 struct perf_event
*leader
= event
->group_leader
;
2147 struct perf_event
*sibling
, *tmp
;
2148 struct perf_event_context
*ctx
= event
->ctx
;
2150 lockdep_assert_held(&ctx
->lock
);
2153 * We can have double detach due to exit/hot-unplug + close.
2155 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
2158 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
2160 perf_put_aux_event(event
);
2163 * If this is a sibling, remove it from its group.
2165 if (leader
!= event
) {
2166 list_del_init(&event
->sibling_list
);
2167 event
->group_leader
->nr_siblings
--;
2172 * If this was a group event with sibling events then
2173 * upgrade the siblings to singleton events by adding them
2174 * to whatever list we are on.
2176 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, sibling_list
) {
2178 if (sibling
->event_caps
& PERF_EV_CAP_SIBLING
)
2179 perf_remove_sibling_event(sibling
);
2181 sibling
->group_leader
= sibling
;
2182 list_del_init(&sibling
->sibling_list
);
2184 /* Inherit group flags from the previous leader */
2185 sibling
->group_caps
= event
->group_caps
;
2187 if (!RB_EMPTY_NODE(&event
->group_node
)) {
2188 add_event_to_groups(sibling
, event
->ctx
);
2190 if (sibling
->state
== PERF_EVENT_STATE_ACTIVE
)
2191 list_add_tail(&sibling
->active_list
, get_event_list(sibling
));
2194 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
2198 for_each_sibling_event(tmp
, leader
)
2199 perf_event__header_size(tmp
);
2201 perf_event__header_size(leader
);
2204 static void sync_child_event(struct perf_event
*child_event
);
2206 static void perf_child_detach(struct perf_event
*event
)
2208 struct perf_event
*parent_event
= event
->parent
;
2210 if (!(event
->attach_state
& PERF_ATTACH_CHILD
))
2213 event
->attach_state
&= ~PERF_ATTACH_CHILD
;
2215 if (WARN_ON_ONCE(!parent_event
))
2218 lockdep_assert_held(&parent_event
->child_mutex
);
2220 sync_child_event(event
);
2221 list_del_init(&event
->child_list
);
2224 static bool is_orphaned_event(struct perf_event
*event
)
2226 return event
->state
== PERF_EVENT_STATE_DEAD
;
2229 static inline int __pmu_filter_match(struct perf_event
*event
)
2231 struct pmu
*pmu
= event
->pmu
;
2232 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
2236 * Check whether we should attempt to schedule an event group based on
2237 * PMU-specific filtering. An event group can consist of HW and SW events,
2238 * potentially with a SW leader, so we must check all the filters, to
2239 * determine whether a group is schedulable:
2241 static inline int pmu_filter_match(struct perf_event
*event
)
2243 struct perf_event
*sibling
;
2245 if (!__pmu_filter_match(event
))
2248 for_each_sibling_event(sibling
, event
) {
2249 if (!__pmu_filter_match(sibling
))
2257 event_filter_match(struct perf_event
*event
)
2259 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
2260 perf_cgroup_match(event
) && pmu_filter_match(event
);
2264 event_sched_out(struct perf_event
*event
,
2265 struct perf_cpu_context
*cpuctx
,
2266 struct perf_event_context
*ctx
)
2268 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
2270 WARN_ON_ONCE(event
->ctx
!= ctx
);
2271 lockdep_assert_held(&ctx
->lock
);
2273 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2277 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2278 * we can schedule events _OUT_ individually through things like
2279 * __perf_remove_from_context().
2281 list_del_init(&event
->active_list
);
2283 perf_pmu_disable(event
->pmu
);
2285 event
->pmu
->del(event
, 0);
2288 if (READ_ONCE(event
->pending_disable
) >= 0) {
2289 WRITE_ONCE(event
->pending_disable
, -1);
2290 perf_cgroup_event_disable(event
, ctx
);
2291 state
= PERF_EVENT_STATE_OFF
;
2293 perf_event_set_state(event
, state
);
2295 if (!is_software_event(event
))
2296 cpuctx
->active_oncpu
--;
2297 if (!--ctx
->nr_active
)
2298 perf_event_ctx_deactivate(ctx
);
2299 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2301 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
2302 cpuctx
->exclusive
= 0;
2304 perf_pmu_enable(event
->pmu
);
2308 group_sched_out(struct perf_event
*group_event
,
2309 struct perf_cpu_context
*cpuctx
,
2310 struct perf_event_context
*ctx
)
2312 struct perf_event
*event
;
2314 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2317 perf_pmu_disable(ctx
->pmu
);
2319 event_sched_out(group_event
, cpuctx
, ctx
);
2322 * Schedule out siblings (if any):
2324 for_each_sibling_event(event
, group_event
)
2325 event_sched_out(event
, cpuctx
, ctx
);
2327 perf_pmu_enable(ctx
->pmu
);
2330 #define DETACH_GROUP 0x01UL
2331 #define DETACH_CHILD 0x02UL
2334 * Cross CPU call to remove a performance event
2336 * We disable the event on the hardware level first. After that we
2337 * remove it from the context list.
2340 __perf_remove_from_context(struct perf_event
*event
,
2341 struct perf_cpu_context
*cpuctx
,
2342 struct perf_event_context
*ctx
,
2345 unsigned long flags
= (unsigned long)info
;
2347 if (ctx
->is_active
& EVENT_TIME
) {
2348 update_context_time(ctx
);
2349 update_cgrp_time_from_cpuctx(cpuctx
);
2352 event_sched_out(event
, cpuctx
, ctx
);
2353 if (flags
& DETACH_GROUP
)
2354 perf_group_detach(event
);
2355 if (flags
& DETACH_CHILD
)
2356 perf_child_detach(event
);
2357 list_del_event(event
, ctx
);
2359 if (!ctx
->nr_events
&& ctx
->is_active
) {
2361 ctx
->rotate_necessary
= 0;
2363 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2364 cpuctx
->task_ctx
= NULL
;
2370 * Remove the event from a task's (or a CPU's) list of events.
2372 * If event->ctx is a cloned context, callers must make sure that
2373 * every task struct that event->ctx->task could possibly point to
2374 * remains valid. This is OK when called from perf_release since
2375 * that only calls us on the top-level context, which can't be a clone.
2376 * When called from perf_event_exit_task, it's OK because the
2377 * context has been detached from its task.
2379 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
2381 struct perf_event_context
*ctx
= event
->ctx
;
2383 lockdep_assert_held(&ctx
->mutex
);
2386 * Because of perf_event_exit_task(), perf_remove_from_context() ought
2387 * to work in the face of TASK_TOMBSTONE, unlike every other
2388 * event_function_call() user.
2390 raw_spin_lock_irq(&ctx
->lock
);
2391 if (!ctx
->is_active
) {
2392 __perf_remove_from_context(event
, __get_cpu_context(ctx
),
2393 ctx
, (void *)flags
);
2394 raw_spin_unlock_irq(&ctx
->lock
);
2397 raw_spin_unlock_irq(&ctx
->lock
);
2399 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
2403 * Cross CPU call to disable a performance event
2405 static void __perf_event_disable(struct perf_event
*event
,
2406 struct perf_cpu_context
*cpuctx
,
2407 struct perf_event_context
*ctx
,
2410 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
2413 if (ctx
->is_active
& EVENT_TIME
) {
2414 update_context_time(ctx
);
2415 update_cgrp_time_from_event(event
);
2418 if (event
== event
->group_leader
)
2419 group_sched_out(event
, cpuctx
, ctx
);
2421 event_sched_out(event
, cpuctx
, ctx
);
2423 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2424 perf_cgroup_event_disable(event
, ctx
);
2430 * If event->ctx is a cloned context, callers must make sure that
2431 * every task struct that event->ctx->task could possibly point to
2432 * remains valid. This condition is satisfied when called through
2433 * perf_event_for_each_child or perf_event_for_each because they
2434 * hold the top-level event's child_mutex, so any descendant that
2435 * goes to exit will block in perf_event_exit_event().
2437 * When called from perf_pending_event it's OK because event->ctx
2438 * is the current context on this CPU and preemption is disabled,
2439 * hence we can't get into perf_event_task_sched_out for this context.
2441 static void _perf_event_disable(struct perf_event
*event
)
2443 struct perf_event_context
*ctx
= event
->ctx
;
2445 raw_spin_lock_irq(&ctx
->lock
);
2446 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2447 raw_spin_unlock_irq(&ctx
->lock
);
2450 raw_spin_unlock_irq(&ctx
->lock
);
2452 event_function_call(event
, __perf_event_disable
, NULL
);
2455 void perf_event_disable_local(struct perf_event
*event
)
2457 event_function_local(event
, __perf_event_disable
, NULL
);
2461 * Strictly speaking kernel users cannot create groups and therefore this
2462 * interface does not need the perf_event_ctx_lock() magic.
2464 void perf_event_disable(struct perf_event
*event
)
2466 struct perf_event_context
*ctx
;
2468 ctx
= perf_event_ctx_lock(event
);
2469 _perf_event_disable(event
);
2470 perf_event_ctx_unlock(event
, ctx
);
2472 EXPORT_SYMBOL_GPL(perf_event_disable
);
2474 void perf_event_disable_inatomic(struct perf_event
*event
)
2476 WRITE_ONCE(event
->pending_disable
, smp_processor_id());
2477 /* can fail, see perf_pending_event_disable() */
2478 irq_work_queue(&event
->pending
);
2481 static void perf_set_shadow_time(struct perf_event
*event
,
2482 struct perf_event_context
*ctx
)
2485 * use the correct time source for the time snapshot
2487 * We could get by without this by leveraging the
2488 * fact that to get to this function, the caller
2489 * has most likely already called update_context_time()
2490 * and update_cgrp_time_xx() and thus both timestamp
2491 * are identical (or very close). Given that tstamp is,
2492 * already adjusted for cgroup, we could say that:
2493 * tstamp - ctx->timestamp
2495 * tstamp - cgrp->timestamp.
2497 * Then, in perf_output_read(), the calculation would
2498 * work with no changes because:
2499 * - event is guaranteed scheduled in
2500 * - no scheduled out in between
2501 * - thus the timestamp would be the same
2503 * But this is a bit hairy.
2505 * So instead, we have an explicit cgroup call to remain
2506 * within the time source all along. We believe it
2507 * is cleaner and simpler to understand.
2509 if (is_cgroup_event(event
))
2510 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2512 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2515 #define MAX_INTERRUPTS (~0ULL)
2517 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2518 static void perf_log_itrace_start(struct perf_event
*event
);
2521 event_sched_in(struct perf_event
*event
,
2522 struct perf_cpu_context
*cpuctx
,
2523 struct perf_event_context
*ctx
)
2527 WARN_ON_ONCE(event
->ctx
!= ctx
);
2529 lockdep_assert_held(&ctx
->lock
);
2531 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2534 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2536 * Order event::oncpu write to happen before the ACTIVE state is
2537 * visible. This allows perf_event_{stop,read}() to observe the correct
2538 * ->oncpu if it sees ACTIVE.
2541 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2544 * Unthrottle events, since we scheduled we might have missed several
2545 * ticks already, also for a heavily scheduling task there is little
2546 * guarantee it'll get a tick in a timely manner.
2548 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2549 perf_log_throttle(event
, 1);
2550 event
->hw
.interrupts
= 0;
2553 perf_pmu_disable(event
->pmu
);
2555 perf_set_shadow_time(event
, ctx
);
2557 perf_log_itrace_start(event
);
2559 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2560 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2566 if (!is_software_event(event
))
2567 cpuctx
->active_oncpu
++;
2568 if (!ctx
->nr_active
++)
2569 perf_event_ctx_activate(ctx
);
2570 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2573 if (event
->attr
.exclusive
)
2574 cpuctx
->exclusive
= 1;
2577 perf_pmu_enable(event
->pmu
);
2583 group_sched_in(struct perf_event
*group_event
,
2584 struct perf_cpu_context
*cpuctx
,
2585 struct perf_event_context
*ctx
)
2587 struct perf_event
*event
, *partial_group
= NULL
;
2588 struct pmu
*pmu
= ctx
->pmu
;
2590 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2593 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2595 if (event_sched_in(group_event
, cpuctx
, ctx
))
2599 * Schedule in siblings as one group (if any):
2601 for_each_sibling_event(event
, group_event
) {
2602 if (event_sched_in(event
, cpuctx
, ctx
)) {
2603 partial_group
= event
;
2608 if (!pmu
->commit_txn(pmu
))
2613 * Groups can be scheduled in as one unit only, so undo any
2614 * partial group before returning:
2615 * The events up to the failed event are scheduled out normally.
2617 for_each_sibling_event(event
, group_event
) {
2618 if (event
== partial_group
)
2621 event_sched_out(event
, cpuctx
, ctx
);
2623 event_sched_out(group_event
, cpuctx
, ctx
);
2626 pmu
->cancel_txn(pmu
);
2631 * Work out whether we can put this event group on the CPU now.
2633 static int group_can_go_on(struct perf_event
*event
,
2634 struct perf_cpu_context
*cpuctx
,
2638 * Groups consisting entirely of software events can always go on.
2640 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2643 * If an exclusive group is already on, no other hardware
2646 if (cpuctx
->exclusive
)
2649 * If this group is exclusive and there are already
2650 * events on the CPU, it can't go on.
2652 if (event
->attr
.exclusive
&& !list_empty(get_event_list(event
)))
2655 * Otherwise, try to add it if all previous groups were able
2661 static void add_event_to_ctx(struct perf_event
*event
,
2662 struct perf_event_context
*ctx
)
2664 list_add_event(event
, ctx
);
2665 perf_group_attach(event
);
2668 static void ctx_sched_out(struct perf_event_context
*ctx
,
2669 struct perf_cpu_context
*cpuctx
,
2670 enum event_type_t event_type
);
2672 ctx_sched_in(struct perf_event_context
*ctx
,
2673 struct perf_cpu_context
*cpuctx
,
2674 enum event_type_t event_type
,
2675 struct task_struct
*task
);
2677 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2678 struct perf_event_context
*ctx
,
2679 enum event_type_t event_type
)
2681 if (!cpuctx
->task_ctx
)
2684 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2687 ctx_sched_out(ctx
, cpuctx
, event_type
);
2690 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2691 struct perf_event_context
*ctx
,
2692 struct task_struct
*task
)
2694 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2696 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2697 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2699 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2703 * We want to maintain the following priority of scheduling:
2704 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2705 * - task pinned (EVENT_PINNED)
2706 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2707 * - task flexible (EVENT_FLEXIBLE).
2709 * In order to avoid unscheduling and scheduling back in everything every
2710 * time an event is added, only do it for the groups of equal priority and
2713 * This can be called after a batch operation on task events, in which case
2714 * event_type is a bit mask of the types of events involved. For CPU events,
2715 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2717 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2718 struct perf_event_context
*task_ctx
,
2719 enum event_type_t event_type
)
2721 enum event_type_t ctx_event_type
;
2722 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2725 * If pinned groups are involved, flexible groups also need to be
2728 if (event_type
& EVENT_PINNED
)
2729 event_type
|= EVENT_FLEXIBLE
;
2731 ctx_event_type
= event_type
& EVENT_ALL
;
2733 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2735 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2738 * Decide which cpu ctx groups to schedule out based on the types
2739 * of events that caused rescheduling:
2740 * - EVENT_CPU: schedule out corresponding groups;
2741 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2742 * - otherwise, do nothing more.
2745 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2746 else if (ctx_event_type
& EVENT_PINNED
)
2747 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2749 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2750 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2753 void perf_pmu_resched(struct pmu
*pmu
)
2755 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2756 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2758 perf_ctx_lock(cpuctx
, task_ctx
);
2759 ctx_resched(cpuctx
, task_ctx
, EVENT_ALL
|EVENT_CPU
);
2760 perf_ctx_unlock(cpuctx
, task_ctx
);
2764 * Cross CPU call to install and enable a performance event
2766 * Very similar to remote_function() + event_function() but cannot assume that
2767 * things like ctx->is_active and cpuctx->task_ctx are set.
2769 static int __perf_install_in_context(void *info
)
2771 struct perf_event
*event
= info
;
2772 struct perf_event_context
*ctx
= event
->ctx
;
2773 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2774 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2775 bool reprogram
= true;
2778 raw_spin_lock(&cpuctx
->ctx
.lock
);
2780 raw_spin_lock(&ctx
->lock
);
2783 reprogram
= (ctx
->task
== current
);
2786 * If the task is running, it must be running on this CPU,
2787 * otherwise we cannot reprogram things.
2789 * If its not running, we don't care, ctx->lock will
2790 * serialize against it becoming runnable.
2792 if (task_curr(ctx
->task
) && !reprogram
) {
2797 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2798 } else if (task_ctx
) {
2799 raw_spin_lock(&task_ctx
->lock
);
2802 #ifdef CONFIG_CGROUP_PERF
2803 if (event
->state
> PERF_EVENT_STATE_OFF
&& is_cgroup_event(event
)) {
2805 * If the current cgroup doesn't match the event's
2806 * cgroup, we should not try to schedule it.
2808 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2809 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2810 event
->cgrp
->css
.cgroup
);
2815 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2816 add_event_to_ctx(event
, ctx
);
2817 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2819 add_event_to_ctx(event
, ctx
);
2823 perf_ctx_unlock(cpuctx
, task_ctx
);
2828 static bool exclusive_event_installable(struct perf_event
*event
,
2829 struct perf_event_context
*ctx
);
2832 * Attach a performance event to a context.
2834 * Very similar to event_function_call, see comment there.
2837 perf_install_in_context(struct perf_event_context
*ctx
,
2838 struct perf_event
*event
,
2841 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2843 lockdep_assert_held(&ctx
->mutex
);
2845 WARN_ON_ONCE(!exclusive_event_installable(event
, ctx
));
2847 if (event
->cpu
!= -1)
2851 * Ensures that if we can observe event->ctx, both the event and ctx
2852 * will be 'complete'. See perf_iterate_sb_cpu().
2854 smp_store_release(&event
->ctx
, ctx
);
2857 * perf_event_attr::disabled events will not run and can be initialized
2858 * without IPI. Except when this is the first event for the context, in
2859 * that case we need the magic of the IPI to set ctx->is_active.
2861 * The IOC_ENABLE that is sure to follow the creation of a disabled
2862 * event will issue the IPI and reprogram the hardware.
2864 if (__perf_effective_state(event
) == PERF_EVENT_STATE_OFF
&& ctx
->nr_events
) {
2865 raw_spin_lock_irq(&ctx
->lock
);
2866 if (ctx
->task
== TASK_TOMBSTONE
) {
2867 raw_spin_unlock_irq(&ctx
->lock
);
2870 add_event_to_ctx(event
, ctx
);
2871 raw_spin_unlock_irq(&ctx
->lock
);
2876 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2881 * Should not happen, we validate the ctx is still alive before calling.
2883 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2887 * Installing events is tricky because we cannot rely on ctx->is_active
2888 * to be set in case this is the nr_events 0 -> 1 transition.
2890 * Instead we use task_curr(), which tells us if the task is running.
2891 * However, since we use task_curr() outside of rq::lock, we can race
2892 * against the actual state. This means the result can be wrong.
2894 * If we get a false positive, we retry, this is harmless.
2896 * If we get a false negative, things are complicated. If we are after
2897 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2898 * value must be correct. If we're before, it doesn't matter since
2899 * perf_event_context_sched_in() will program the counter.
2901 * However, this hinges on the remote context switch having observed
2902 * our task->perf_event_ctxp[] store, such that it will in fact take
2903 * ctx::lock in perf_event_context_sched_in().
2905 * We do this by task_function_call(), if the IPI fails to hit the task
2906 * we know any future context switch of task must see the
2907 * perf_event_ctpx[] store.
2911 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2912 * task_cpu() load, such that if the IPI then does not find the task
2913 * running, a future context switch of that task must observe the
2918 if (!task_function_call(task
, __perf_install_in_context
, event
))
2921 raw_spin_lock_irq(&ctx
->lock
);
2923 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2925 * Cannot happen because we already checked above (which also
2926 * cannot happen), and we hold ctx->mutex, which serializes us
2927 * against perf_event_exit_task_context().
2929 raw_spin_unlock_irq(&ctx
->lock
);
2933 * If the task is not running, ctx->lock will avoid it becoming so,
2934 * thus we can safely install the event.
2936 if (task_curr(task
)) {
2937 raw_spin_unlock_irq(&ctx
->lock
);
2940 add_event_to_ctx(event
, ctx
);
2941 raw_spin_unlock_irq(&ctx
->lock
);
2945 * Cross CPU call to enable a performance event
2947 static void __perf_event_enable(struct perf_event
*event
,
2948 struct perf_cpu_context
*cpuctx
,
2949 struct perf_event_context
*ctx
,
2952 struct perf_event
*leader
= event
->group_leader
;
2953 struct perf_event_context
*task_ctx
;
2955 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2956 event
->state
<= PERF_EVENT_STATE_ERROR
)
2960 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2962 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2963 perf_cgroup_event_enable(event
, ctx
);
2965 if (!ctx
->is_active
)
2968 if (!event_filter_match(event
)) {
2969 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2974 * If the event is in a group and isn't the group leader,
2975 * then don't put it on unless the group is on.
2977 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2978 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2982 task_ctx
= cpuctx
->task_ctx
;
2984 WARN_ON_ONCE(task_ctx
!= ctx
);
2986 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2992 * If event->ctx is a cloned context, callers must make sure that
2993 * every task struct that event->ctx->task could possibly point to
2994 * remains valid. This condition is satisfied when called through
2995 * perf_event_for_each_child or perf_event_for_each as described
2996 * for perf_event_disable.
2998 static void _perf_event_enable(struct perf_event
*event
)
3000 struct perf_event_context
*ctx
= event
->ctx
;
3002 raw_spin_lock_irq(&ctx
->lock
);
3003 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
3004 event
->state
< PERF_EVENT_STATE_ERROR
) {
3006 raw_spin_unlock_irq(&ctx
->lock
);
3011 * If the event is in error state, clear that first.
3013 * That way, if we see the event in error state below, we know that it
3014 * has gone back into error state, as distinct from the task having
3015 * been scheduled away before the cross-call arrived.
3017 if (event
->state
== PERF_EVENT_STATE_ERROR
) {
3019 * Detached SIBLING events cannot leave ERROR state.
3021 if (event
->event_caps
& PERF_EV_CAP_SIBLING
&&
3022 event
->group_leader
== event
)
3025 event
->state
= PERF_EVENT_STATE_OFF
;
3027 raw_spin_unlock_irq(&ctx
->lock
);
3029 event_function_call(event
, __perf_event_enable
, NULL
);
3033 * See perf_event_disable();
3035 void perf_event_enable(struct perf_event
*event
)
3037 struct perf_event_context
*ctx
;
3039 ctx
= perf_event_ctx_lock(event
);
3040 _perf_event_enable(event
);
3041 perf_event_ctx_unlock(event
, ctx
);
3043 EXPORT_SYMBOL_GPL(perf_event_enable
);
3045 struct stop_event_data
{
3046 struct perf_event
*event
;
3047 unsigned int restart
;
3050 static int __perf_event_stop(void *info
)
3052 struct stop_event_data
*sd
= info
;
3053 struct perf_event
*event
= sd
->event
;
3055 /* if it's already INACTIVE, do nothing */
3056 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
3059 /* matches smp_wmb() in event_sched_in() */
3063 * There is a window with interrupts enabled before we get here,
3064 * so we need to check again lest we try to stop another CPU's event.
3066 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
3069 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3072 * May race with the actual stop (through perf_pmu_output_stop()),
3073 * but it is only used for events with AUX ring buffer, and such
3074 * events will refuse to restart because of rb::aux_mmap_count==0,
3075 * see comments in perf_aux_output_begin().
3077 * Since this is happening on an event-local CPU, no trace is lost
3081 event
->pmu
->start(event
, 0);
3086 static int perf_event_stop(struct perf_event
*event
, int restart
)
3088 struct stop_event_data sd
= {
3095 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
3098 /* matches smp_wmb() in event_sched_in() */
3102 * We only want to restart ACTIVE events, so if the event goes
3103 * inactive here (event->oncpu==-1), there's nothing more to do;
3104 * fall through with ret==-ENXIO.
3106 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
3107 __perf_event_stop
, &sd
);
3108 } while (ret
== -EAGAIN
);
3114 * In order to contain the amount of racy and tricky in the address filter
3115 * configuration management, it is a two part process:
3117 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
3118 * we update the addresses of corresponding vmas in
3119 * event::addr_filter_ranges array and bump the event::addr_filters_gen;
3120 * (p2) when an event is scheduled in (pmu::add), it calls
3121 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
3122 * if the generation has changed since the previous call.
3124 * If (p1) happens while the event is active, we restart it to force (p2).
3126 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
3127 * pre-existing mappings, called once when new filters arrive via SET_FILTER
3129 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
3130 * registered mapping, called for every new mmap(), with mm::mmap_lock down
3132 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
3135 void perf_event_addr_filters_sync(struct perf_event
*event
)
3137 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
3139 if (!has_addr_filter(event
))
3142 raw_spin_lock(&ifh
->lock
);
3143 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
3144 event
->pmu
->addr_filters_sync(event
);
3145 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
3147 raw_spin_unlock(&ifh
->lock
);
3149 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
3151 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
3154 * not supported on inherited events
3156 if (event
->attr
.inherit
|| !is_sampling_event(event
))
3159 atomic_add(refresh
, &event
->event_limit
);
3160 _perf_event_enable(event
);
3166 * See perf_event_disable()
3168 int perf_event_refresh(struct perf_event
*event
, int refresh
)
3170 struct perf_event_context
*ctx
;
3173 ctx
= perf_event_ctx_lock(event
);
3174 ret
= _perf_event_refresh(event
, refresh
);
3175 perf_event_ctx_unlock(event
, ctx
);
3179 EXPORT_SYMBOL_GPL(perf_event_refresh
);
3181 static int perf_event_modify_breakpoint(struct perf_event
*bp
,
3182 struct perf_event_attr
*attr
)
3186 _perf_event_disable(bp
);
3188 err
= modify_user_hw_breakpoint_check(bp
, attr
, true);
3190 if (!bp
->attr
.disabled
)
3191 _perf_event_enable(bp
);
3196 static int perf_event_modify_attr(struct perf_event
*event
,
3197 struct perf_event_attr
*attr
)
3199 int (*func
)(struct perf_event
*, struct perf_event_attr
*);
3200 struct perf_event
*child
;
3203 if (event
->attr
.type
!= attr
->type
)
3206 switch (event
->attr
.type
) {
3207 case PERF_TYPE_BREAKPOINT
:
3208 func
= perf_event_modify_breakpoint
;
3211 /* Place holder for future additions. */
3215 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3217 mutex_lock(&event
->child_mutex
);
3218 err
= func(event
, attr
);
3221 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3222 err
= func(child
, attr
);
3227 mutex_unlock(&event
->child_mutex
);
3231 static void ctx_sched_out(struct perf_event_context
*ctx
,
3232 struct perf_cpu_context
*cpuctx
,
3233 enum event_type_t event_type
)
3235 struct perf_event
*event
, *tmp
;
3236 int is_active
= ctx
->is_active
;
3238 lockdep_assert_held(&ctx
->lock
);
3240 if (likely(!ctx
->nr_events
)) {
3242 * See __perf_remove_from_context().
3244 WARN_ON_ONCE(ctx
->is_active
);
3246 WARN_ON_ONCE(cpuctx
->task_ctx
);
3250 ctx
->is_active
&= ~event_type
;
3251 if (!(ctx
->is_active
& EVENT_ALL
))
3255 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3256 if (!ctx
->is_active
)
3257 cpuctx
->task_ctx
= NULL
;
3261 * Always update time if it was set; not only when it changes.
3262 * Otherwise we can 'forget' to update time for any but the last
3263 * context we sched out. For example:
3265 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
3266 * ctx_sched_out(.event_type = EVENT_PINNED)
3268 * would only update time for the pinned events.
3270 if (is_active
& EVENT_TIME
) {
3271 /* update (and stop) ctx time */
3272 update_context_time(ctx
);
3273 update_cgrp_time_from_cpuctx(cpuctx
);
3276 is_active
^= ctx
->is_active
; /* changed bits */
3278 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
3281 perf_pmu_disable(ctx
->pmu
);
3282 if (is_active
& EVENT_PINNED
) {
3283 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_active
, active_list
)
3284 group_sched_out(event
, cpuctx
, ctx
);
3287 if (is_active
& EVENT_FLEXIBLE
) {
3288 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_active
, active_list
)
3289 group_sched_out(event
, cpuctx
, ctx
);
3292 * Since we cleared EVENT_FLEXIBLE, also clear
3293 * rotate_necessary, is will be reset by
3294 * ctx_flexible_sched_in() when needed.
3296 ctx
->rotate_necessary
= 0;
3298 perf_pmu_enable(ctx
->pmu
);
3302 * Test whether two contexts are equivalent, i.e. whether they have both been
3303 * cloned from the same version of the same context.
3305 * Equivalence is measured using a generation number in the context that is
3306 * incremented on each modification to it; see unclone_ctx(), list_add_event()
3307 * and list_del_event().
3309 static int context_equiv(struct perf_event_context
*ctx1
,
3310 struct perf_event_context
*ctx2
)
3312 lockdep_assert_held(&ctx1
->lock
);
3313 lockdep_assert_held(&ctx2
->lock
);
3315 /* Pinning disables the swap optimization */
3316 if (ctx1
->pin_count
|| ctx2
->pin_count
)
3319 /* If ctx1 is the parent of ctx2 */
3320 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
3323 /* If ctx2 is the parent of ctx1 */
3324 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
3328 * If ctx1 and ctx2 have the same parent; we flatten the parent
3329 * hierarchy, see perf_event_init_context().
3331 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
3332 ctx1
->parent_gen
== ctx2
->parent_gen
)
3339 static void __perf_event_sync_stat(struct perf_event
*event
,
3340 struct perf_event
*next_event
)
3344 if (!event
->attr
.inherit_stat
)
3348 * Update the event value, we cannot use perf_event_read()
3349 * because we're in the middle of a context switch and have IRQs
3350 * disabled, which upsets smp_call_function_single(), however
3351 * we know the event must be on the current CPU, therefore we
3352 * don't need to use it.
3354 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3355 event
->pmu
->read(event
);
3357 perf_event_update_time(event
);
3360 * In order to keep per-task stats reliable we need to flip the event
3361 * values when we flip the contexts.
3363 value
= local64_read(&next_event
->count
);
3364 value
= local64_xchg(&event
->count
, value
);
3365 local64_set(&next_event
->count
, value
);
3367 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
3368 swap(event
->total_time_running
, next_event
->total_time_running
);
3371 * Since we swizzled the values, update the user visible data too.
3373 perf_event_update_userpage(event
);
3374 perf_event_update_userpage(next_event
);
3377 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
3378 struct perf_event_context
*next_ctx
)
3380 struct perf_event
*event
, *next_event
;
3385 update_context_time(ctx
);
3387 event
= list_first_entry(&ctx
->event_list
,
3388 struct perf_event
, event_entry
);
3390 next_event
= list_first_entry(&next_ctx
->event_list
,
3391 struct perf_event
, event_entry
);
3393 while (&event
->event_entry
!= &ctx
->event_list
&&
3394 &next_event
->event_entry
!= &next_ctx
->event_list
) {
3396 __perf_event_sync_stat(event
, next_event
);
3398 event
= list_next_entry(event
, event_entry
);
3399 next_event
= list_next_entry(next_event
, event_entry
);
3403 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
3404 struct task_struct
*next
)
3406 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
3407 struct perf_event_context
*next_ctx
;
3408 struct perf_event_context
*parent
, *next_parent
;
3409 struct perf_cpu_context
*cpuctx
;
3417 cpuctx
= __get_cpu_context(ctx
);
3418 if (!cpuctx
->task_ctx
)
3422 next_ctx
= next
->perf_event_ctxp
[ctxn
];
3426 parent
= rcu_dereference(ctx
->parent_ctx
);
3427 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
3429 /* If neither context have a parent context; they cannot be clones. */
3430 if (!parent
&& !next_parent
)
3433 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
3435 * Looks like the two contexts are clones, so we might be
3436 * able to optimize the context switch. We lock both
3437 * contexts and check that they are clones under the
3438 * lock (including re-checking that neither has been
3439 * uncloned in the meantime). It doesn't matter which
3440 * order we take the locks because no other cpu could
3441 * be trying to lock both of these tasks.
3443 raw_spin_lock(&ctx
->lock
);
3444 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3445 if (context_equiv(ctx
, next_ctx
)) {
3447 WRITE_ONCE(ctx
->task
, next
);
3448 WRITE_ONCE(next_ctx
->task
, task
);
3450 perf_pmu_disable(pmu
);
3452 if (cpuctx
->sched_cb_usage
&& pmu
->sched_task
)
3453 pmu
->sched_task(ctx
, false);
3456 * PMU specific parts of task perf context can require
3457 * additional synchronization. As an example of such
3458 * synchronization see implementation details of Intel
3459 * LBR call stack data profiling;
3461 if (pmu
->swap_task_ctx
)
3462 pmu
->swap_task_ctx(ctx
, next_ctx
);
3464 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3466 perf_pmu_enable(pmu
);
3469 * RCU_INIT_POINTER here is safe because we've not
3470 * modified the ctx and the above modification of
3471 * ctx->task and ctx->task_ctx_data are immaterial
3472 * since those values are always verified under
3473 * ctx->lock which we're now holding.
3475 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3476 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3480 perf_event_sync_stat(ctx
, next_ctx
);
3482 raw_spin_unlock(&next_ctx
->lock
);
3483 raw_spin_unlock(&ctx
->lock
);
3489 raw_spin_lock(&ctx
->lock
);
3490 perf_pmu_disable(pmu
);
3492 if (cpuctx
->sched_cb_usage
&& pmu
->sched_task
)
3493 pmu
->sched_task(ctx
, false);
3494 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3496 perf_pmu_enable(pmu
);
3497 raw_spin_unlock(&ctx
->lock
);
3501 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3503 void perf_sched_cb_dec(struct pmu
*pmu
)
3505 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3507 this_cpu_dec(perf_sched_cb_usages
);
3509 if (!--cpuctx
->sched_cb_usage
)
3510 list_del(&cpuctx
->sched_cb_entry
);
3514 void perf_sched_cb_inc(struct pmu
*pmu
)
3516 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3518 if (!cpuctx
->sched_cb_usage
++)
3519 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3521 this_cpu_inc(perf_sched_cb_usages
);
3525 * This function provides the context switch callback to the lower code
3526 * layer. It is invoked ONLY when the context switch callback is enabled.
3528 * This callback is relevant even to per-cpu events; for example multi event
3529 * PEBS requires this to provide PID/TID information. This requires we flush
3530 * all queued PEBS records before we context switch to a new task.
3532 static void __perf_pmu_sched_task(struct perf_cpu_context
*cpuctx
, bool sched_in
)
3536 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3538 if (WARN_ON_ONCE(!pmu
->sched_task
))
3541 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3542 perf_pmu_disable(pmu
);
3544 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3546 perf_pmu_enable(pmu
);
3547 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3550 static void perf_pmu_sched_task(struct task_struct
*prev
,
3551 struct task_struct
*next
,
3554 struct perf_cpu_context
*cpuctx
;
3559 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3560 /* will be handled in perf_event_context_sched_in/out */
3561 if (cpuctx
->task_ctx
)
3564 __perf_pmu_sched_task(cpuctx
, sched_in
);
3568 static void perf_event_switch(struct task_struct
*task
,
3569 struct task_struct
*next_prev
, bool sched_in
);
3571 #define for_each_task_context_nr(ctxn) \
3572 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3575 * Called from scheduler to remove the events of the current task,
3576 * with interrupts disabled.
3578 * We stop each event and update the event value in event->count.
3580 * This does not protect us against NMI, but disable()
3581 * sets the disabled bit in the control field of event _before_
3582 * accessing the event control register. If a NMI hits, then it will
3583 * not restart the event.
3585 void __perf_event_task_sched_out(struct task_struct
*task
,
3586 struct task_struct
*next
)
3590 if (__this_cpu_read(perf_sched_cb_usages
))
3591 perf_pmu_sched_task(task
, next
, false);
3593 if (atomic_read(&nr_switch_events
))
3594 perf_event_switch(task
, next
, false);
3596 for_each_task_context_nr(ctxn
)
3597 perf_event_context_sched_out(task
, ctxn
, next
);
3600 * if cgroup events exist on this CPU, then we need
3601 * to check if we have to switch out PMU state.
3602 * cgroup event are system-wide mode only
3604 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3605 perf_cgroup_sched_out(task
, next
);
3609 * Called with IRQs disabled
3611 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3612 enum event_type_t event_type
)
3614 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3617 static bool perf_less_group_idx(const void *l
, const void *r
)
3619 const struct perf_event
*le
= *(const struct perf_event
**)l
;
3620 const struct perf_event
*re
= *(const struct perf_event
**)r
;
3622 return le
->group_index
< re
->group_index
;
3625 static void swap_ptr(void *l
, void *r
)
3627 void **lp
= l
, **rp
= r
;
3632 static const struct min_heap_callbacks perf_min_heap
= {
3633 .elem_size
= sizeof(struct perf_event
*),
3634 .less
= perf_less_group_idx
,
3638 static void __heap_add(struct min_heap
*heap
, struct perf_event
*event
)
3640 struct perf_event
**itrs
= heap
->data
;
3643 itrs
[heap
->nr
] = event
;
3648 static noinline
int visit_groups_merge(struct perf_cpu_context
*cpuctx
,
3649 struct perf_event_groups
*groups
, int cpu
,
3650 int (*func
)(struct perf_event
*, void *),
3653 #ifdef CONFIG_CGROUP_PERF
3654 struct cgroup_subsys_state
*css
= NULL
;
3656 /* Space for per CPU and/or any CPU event iterators. */
3657 struct perf_event
*itrs
[2];
3658 struct min_heap event_heap
;
3659 struct perf_event
**evt
;
3663 event_heap
= (struct min_heap
){
3664 .data
= cpuctx
->heap
,
3666 .size
= cpuctx
->heap_size
,
3669 lockdep_assert_held(&cpuctx
->ctx
.lock
);
3671 #ifdef CONFIG_CGROUP_PERF
3673 css
= &cpuctx
->cgrp
->css
;
3676 event_heap
= (struct min_heap
){
3679 .size
= ARRAY_SIZE(itrs
),
3681 /* Events not within a CPU context may be on any CPU. */
3682 __heap_add(&event_heap
, perf_event_groups_first(groups
, -1, NULL
));
3684 evt
= event_heap
.data
;
3686 __heap_add(&event_heap
, perf_event_groups_first(groups
, cpu
, NULL
));
3688 #ifdef CONFIG_CGROUP_PERF
3689 for (; css
; css
= css
->parent
)
3690 __heap_add(&event_heap
, perf_event_groups_first(groups
, cpu
, css
->cgroup
));
3693 min_heapify_all(&event_heap
, &perf_min_heap
);
3695 while (event_heap
.nr
) {
3696 ret
= func(*evt
, data
);
3700 *evt
= perf_event_groups_next(*evt
);
3702 min_heapify(&event_heap
, 0, &perf_min_heap
);
3704 min_heap_pop(&event_heap
, &perf_min_heap
);
3710 static inline bool event_update_userpage(struct perf_event
*event
)
3712 if (likely(!atomic_read(&event
->mmap_count
)))
3715 perf_event_update_time(event
);
3716 perf_set_shadow_time(event
, event
->ctx
);
3717 perf_event_update_userpage(event
);
3722 static inline void group_update_userpage(struct perf_event
*group_event
)
3724 struct perf_event
*event
;
3726 if (!event_update_userpage(group_event
))
3729 for_each_sibling_event(event
, group_event
)
3730 event_update_userpage(event
);
3733 static int merge_sched_in(struct perf_event
*event
, void *data
)
3735 struct perf_event_context
*ctx
= event
->ctx
;
3736 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3737 int *can_add_hw
= data
;
3739 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3742 if (!event_filter_match(event
))
3745 if (group_can_go_on(event
, cpuctx
, *can_add_hw
)) {
3746 if (!group_sched_in(event
, cpuctx
, ctx
))
3747 list_add_tail(&event
->active_list
, get_event_list(event
));
3750 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3752 if (event
->attr
.pinned
) {
3753 perf_cgroup_event_disable(event
, ctx
);
3754 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3756 ctx
->rotate_necessary
= 1;
3757 perf_mux_hrtimer_restart(cpuctx
);
3758 group_update_userpage(event
);
3766 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3767 struct perf_cpu_context
*cpuctx
)
3771 if (ctx
!= &cpuctx
->ctx
)
3774 visit_groups_merge(cpuctx
, &ctx
->pinned_groups
,
3776 merge_sched_in
, &can_add_hw
);
3780 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3781 struct perf_cpu_context
*cpuctx
)
3785 if (ctx
!= &cpuctx
->ctx
)
3788 visit_groups_merge(cpuctx
, &ctx
->flexible_groups
,
3790 merge_sched_in
, &can_add_hw
);
3794 ctx_sched_in(struct perf_event_context
*ctx
,
3795 struct perf_cpu_context
*cpuctx
,
3796 enum event_type_t event_type
,
3797 struct task_struct
*task
)
3799 int is_active
= ctx
->is_active
;
3802 lockdep_assert_held(&ctx
->lock
);
3804 if (likely(!ctx
->nr_events
))
3807 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3810 cpuctx
->task_ctx
= ctx
;
3812 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3815 is_active
^= ctx
->is_active
; /* changed bits */
3817 if (is_active
& EVENT_TIME
) {
3818 /* start ctx time */
3820 ctx
->timestamp
= now
;
3821 perf_cgroup_set_timestamp(task
, ctx
);
3825 * First go through the list and put on any pinned groups
3826 * in order to give them the best chance of going on.
3828 if (is_active
& EVENT_PINNED
)
3829 ctx_pinned_sched_in(ctx
, cpuctx
);
3831 /* Then walk through the lower prio flexible groups */
3832 if (is_active
& EVENT_FLEXIBLE
)
3833 ctx_flexible_sched_in(ctx
, cpuctx
);
3836 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3837 enum event_type_t event_type
,
3838 struct task_struct
*task
)
3840 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3842 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3845 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3846 struct task_struct
*task
)
3848 struct perf_cpu_context
*cpuctx
;
3851 cpuctx
= __get_cpu_context(ctx
);
3854 * HACK: for HETEROGENEOUS the task context might have switched to a
3855 * different PMU, force (re)set the context,
3857 pmu
= ctx
->pmu
= cpuctx
->ctx
.pmu
;
3859 if (cpuctx
->task_ctx
== ctx
) {
3860 if (cpuctx
->sched_cb_usage
)
3861 __perf_pmu_sched_task(cpuctx
, true);
3865 perf_ctx_lock(cpuctx
, ctx
);
3867 * We must check ctx->nr_events while holding ctx->lock, such
3868 * that we serialize against perf_install_in_context().
3870 if (!ctx
->nr_events
)
3873 perf_pmu_disable(pmu
);
3875 * We want to keep the following priority order:
3876 * cpu pinned (that don't need to move), task pinned,
3877 * cpu flexible, task flexible.
3879 * However, if task's ctx is not carrying any pinned
3880 * events, no need to flip the cpuctx's events around.
3882 if (!RB_EMPTY_ROOT(&ctx
->pinned_groups
.tree
))
3883 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3884 perf_event_sched_in(cpuctx
, ctx
, task
);
3886 if (cpuctx
->sched_cb_usage
&& pmu
->sched_task
)
3887 pmu
->sched_task(cpuctx
->task_ctx
, true);
3889 perf_pmu_enable(pmu
);
3892 perf_ctx_unlock(cpuctx
, ctx
);
3896 * Called from scheduler to add the events of the current task
3897 * with interrupts disabled.
3899 * We restore the event value and then enable it.
3901 * This does not protect us against NMI, but enable()
3902 * sets the enabled bit in the control field of event _before_
3903 * accessing the event control register. If a NMI hits, then it will
3904 * keep the event running.
3906 void __perf_event_task_sched_in(struct task_struct
*prev
,
3907 struct task_struct
*task
)
3909 struct perf_event_context
*ctx
;
3913 * If cgroup events exist on this CPU, then we need to check if we have
3914 * to switch in PMU state; cgroup event are system-wide mode only.
3916 * Since cgroup events are CPU events, we must schedule these in before
3917 * we schedule in the task events.
3919 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3920 perf_cgroup_sched_in(prev
, task
);
3922 for_each_task_context_nr(ctxn
) {
3923 ctx
= task
->perf_event_ctxp
[ctxn
];
3927 perf_event_context_sched_in(ctx
, task
);
3930 if (atomic_read(&nr_switch_events
))
3931 perf_event_switch(task
, prev
, true);
3933 if (__this_cpu_read(perf_sched_cb_usages
))
3934 perf_pmu_sched_task(prev
, task
, true);
3937 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3939 u64 frequency
= event
->attr
.sample_freq
;
3940 u64 sec
= NSEC_PER_SEC
;
3941 u64 divisor
, dividend
;
3943 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3945 count_fls
= fls64(count
);
3946 nsec_fls
= fls64(nsec
);
3947 frequency_fls
= fls64(frequency
);
3951 * We got @count in @nsec, with a target of sample_freq HZ
3952 * the target period becomes:
3955 * period = -------------------
3956 * @nsec * sample_freq
3961 * Reduce accuracy by one bit such that @a and @b converge
3962 * to a similar magnitude.
3964 #define REDUCE_FLS(a, b) \
3966 if (a##_fls > b##_fls) { \
3976 * Reduce accuracy until either term fits in a u64, then proceed with
3977 * the other, so that finally we can do a u64/u64 division.
3979 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3980 REDUCE_FLS(nsec
, frequency
);
3981 REDUCE_FLS(sec
, count
);
3984 if (count_fls
+ sec_fls
> 64) {
3985 divisor
= nsec
* frequency
;
3987 while (count_fls
+ sec_fls
> 64) {
3988 REDUCE_FLS(count
, sec
);
3992 dividend
= count
* sec
;
3994 dividend
= count
* sec
;
3996 while (nsec_fls
+ frequency_fls
> 64) {
3997 REDUCE_FLS(nsec
, frequency
);
4001 divisor
= nsec
* frequency
;
4007 return div64_u64(dividend
, divisor
);
4010 static DEFINE_PER_CPU(int, perf_throttled_count
);
4011 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
4013 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
4015 struct hw_perf_event
*hwc
= &event
->hw
;
4016 s64 period
, sample_period
;
4019 period
= perf_calculate_period(event
, nsec
, count
);
4021 delta
= (s64
)(period
- hwc
->sample_period
);
4022 delta
= (delta
+ 7) / 8; /* low pass filter */
4024 sample_period
= hwc
->sample_period
+ delta
;
4029 hwc
->sample_period
= sample_period
;
4031 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
4033 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4035 local64_set(&hwc
->period_left
, 0);
4038 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4043 * combine freq adjustment with unthrottling to avoid two passes over the
4044 * events. At the same time, make sure, having freq events does not change
4045 * the rate of unthrottling as that would introduce bias.
4047 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
4050 struct perf_event
*event
;
4051 struct hw_perf_event
*hwc
;
4052 u64 now
, period
= TICK_NSEC
;
4056 * only need to iterate over all events iff:
4057 * - context have events in frequency mode (needs freq adjust)
4058 * - there are events to unthrottle on this cpu
4060 if (!(ctx
->nr_freq
|| needs_unthr
))
4063 raw_spin_lock(&ctx
->lock
);
4064 perf_pmu_disable(ctx
->pmu
);
4066 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4067 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4070 if (!event_filter_match(event
))
4073 perf_pmu_disable(event
->pmu
);
4077 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
4078 hwc
->interrupts
= 0;
4079 perf_log_throttle(event
, 1);
4080 event
->pmu
->start(event
, 0);
4083 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
4087 * stop the event and update event->count
4089 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4091 now
= local64_read(&event
->count
);
4092 delta
= now
- hwc
->freq_count_stamp
;
4093 hwc
->freq_count_stamp
= now
;
4097 * reload only if value has changed
4098 * we have stopped the event so tell that
4099 * to perf_adjust_period() to avoid stopping it
4103 perf_adjust_period(event
, period
, delta
, false);
4105 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
4107 perf_pmu_enable(event
->pmu
);
4110 perf_pmu_enable(ctx
->pmu
);
4111 raw_spin_unlock(&ctx
->lock
);
4115 * Move @event to the tail of the @ctx's elegible events.
4117 static void rotate_ctx(struct perf_event_context
*ctx
, struct perf_event
*event
)
4120 * Rotate the first entry last of non-pinned groups. Rotation might be
4121 * disabled by the inheritance code.
4123 if (ctx
->rotate_disable
)
4126 perf_event_groups_delete(&ctx
->flexible_groups
, event
);
4127 perf_event_groups_insert(&ctx
->flexible_groups
, event
);
4130 /* pick an event from the flexible_groups to rotate */
4131 static inline struct perf_event
*
4132 ctx_event_to_rotate(struct perf_event_context
*ctx
)
4134 struct perf_event
*event
;
4136 /* pick the first active flexible event */
4137 event
= list_first_entry_or_null(&ctx
->flexible_active
,
4138 struct perf_event
, active_list
);
4140 /* if no active flexible event, pick the first event */
4142 event
= rb_entry_safe(rb_first(&ctx
->flexible_groups
.tree
),
4143 typeof(*event
), group_node
);
4147 * Unconditionally clear rotate_necessary; if ctx_flexible_sched_in()
4148 * finds there are unschedulable events, it will set it again.
4150 ctx
->rotate_necessary
= 0;
4155 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
)
4157 struct perf_event
*cpu_event
= NULL
, *task_event
= NULL
;
4158 struct perf_event_context
*task_ctx
= NULL
;
4159 int cpu_rotate
, task_rotate
;
4162 * Since we run this from IRQ context, nobody can install new
4163 * events, thus the event count values are stable.
4166 cpu_rotate
= cpuctx
->ctx
.rotate_necessary
;
4167 task_ctx
= cpuctx
->task_ctx
;
4168 task_rotate
= task_ctx
? task_ctx
->rotate_necessary
: 0;
4170 if (!(cpu_rotate
|| task_rotate
))
4173 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
4174 perf_pmu_disable(cpuctx
->ctx
.pmu
);
4177 task_event
= ctx_event_to_rotate(task_ctx
);
4179 cpu_event
= ctx_event_to_rotate(&cpuctx
->ctx
);
4182 * As per the order given at ctx_resched() first 'pop' task flexible
4183 * and then, if needed CPU flexible.
4185 if (task_event
|| (task_ctx
&& cpu_event
))
4186 ctx_sched_out(task_ctx
, cpuctx
, EVENT_FLEXIBLE
);
4188 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
4191 rotate_ctx(task_ctx
, task_event
);
4193 rotate_ctx(&cpuctx
->ctx
, cpu_event
);
4195 perf_event_sched_in(cpuctx
, task_ctx
, current
);
4197 perf_pmu_enable(cpuctx
->ctx
.pmu
);
4198 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
4203 void perf_event_task_tick(void)
4205 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
4206 struct perf_event_context
*ctx
, *tmp
;
4209 lockdep_assert_irqs_disabled();
4211 __this_cpu_inc(perf_throttled_seq
);
4212 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
4213 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
4215 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
4216 perf_adjust_freq_unthr_context(ctx
, throttled
);
4219 static int event_enable_on_exec(struct perf_event
*event
,
4220 struct perf_event_context
*ctx
)
4222 if (!event
->attr
.enable_on_exec
)
4225 event
->attr
.enable_on_exec
= 0;
4226 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
4229 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
4235 * Enable all of a task's events that have been marked enable-on-exec.
4236 * This expects task == current.
4238 static void perf_event_enable_on_exec(int ctxn
)
4240 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4241 enum event_type_t event_type
= 0;
4242 struct perf_cpu_context
*cpuctx
;
4243 struct perf_event
*event
;
4244 unsigned long flags
;
4247 local_irq_save(flags
);
4248 ctx
= current
->perf_event_ctxp
[ctxn
];
4249 if (!ctx
|| !ctx
->nr_events
)
4252 cpuctx
= __get_cpu_context(ctx
);
4253 perf_ctx_lock(cpuctx
, ctx
);
4254 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
4255 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
4256 enabled
|= event_enable_on_exec(event
, ctx
);
4257 event_type
|= get_event_type(event
);
4261 * Unclone and reschedule this context if we enabled any event.
4264 clone_ctx
= unclone_ctx(ctx
);
4265 ctx_resched(cpuctx
, ctx
, event_type
);
4267 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
4269 perf_ctx_unlock(cpuctx
, ctx
);
4272 local_irq_restore(flags
);
4278 static void perf_remove_from_owner(struct perf_event
*event
);
4279 static void perf_event_exit_event(struct perf_event
*event
,
4280 struct perf_event_context
*ctx
);
4283 * Removes all events from the current task that have been marked
4284 * remove-on-exec, and feeds their values back to parent events.
4286 static void perf_event_remove_on_exec(int ctxn
)
4288 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4289 struct perf_event
*event
, *next
;
4290 LIST_HEAD(free_list
);
4291 unsigned long flags
;
4292 bool modified
= false;
4294 ctx
= perf_pin_task_context(current
, ctxn
);
4298 mutex_lock(&ctx
->mutex
);
4300 if (WARN_ON_ONCE(ctx
->task
!= current
))
4303 list_for_each_entry_safe(event
, next
, &ctx
->event_list
, event_entry
) {
4304 if (!event
->attr
.remove_on_exec
)
4307 if (!is_kernel_event(event
))
4308 perf_remove_from_owner(event
);
4312 perf_event_exit_event(event
, ctx
);
4315 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4317 clone_ctx
= unclone_ctx(ctx
);
4319 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4322 mutex_unlock(&ctx
->mutex
);
4329 struct perf_read_data
{
4330 struct perf_event
*event
;
4335 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
4337 u16 local_pkg
, event_pkg
;
4339 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
4340 int local_cpu
= smp_processor_id();
4342 event_pkg
= topology_physical_package_id(event_cpu
);
4343 local_pkg
= topology_physical_package_id(local_cpu
);
4345 if (event_pkg
== local_pkg
)
4353 * Cross CPU call to read the hardware event
4355 static void __perf_event_read(void *info
)
4357 struct perf_read_data
*data
= info
;
4358 struct perf_event
*sub
, *event
= data
->event
;
4359 struct perf_event_context
*ctx
= event
->ctx
;
4360 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
4361 struct pmu
*pmu
= event
->pmu
;
4364 * If this is a task context, we need to check whether it is
4365 * the current task context of this cpu. If not it has been
4366 * scheduled out before the smp call arrived. In that case
4367 * event->count would have been updated to a recent sample
4368 * when the event was scheduled out.
4370 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
4373 raw_spin_lock(&ctx
->lock
);
4374 if (ctx
->is_active
& EVENT_TIME
) {
4375 update_context_time(ctx
);
4376 update_cgrp_time_from_event(event
);
4379 perf_event_update_time(event
);
4381 perf_event_update_sibling_time(event
);
4383 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4392 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
4396 for_each_sibling_event(sub
, event
) {
4397 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
4399 * Use sibling's PMU rather than @event's since
4400 * sibling could be on different (eg: software) PMU.
4402 sub
->pmu
->read(sub
);
4406 data
->ret
= pmu
->commit_txn(pmu
);
4409 raw_spin_unlock(&ctx
->lock
);
4412 static inline u64
perf_event_count(struct perf_event
*event
)
4414 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
4418 * NMI-safe method to read a local event, that is an event that
4420 * - either for the current task, or for this CPU
4421 * - does not have inherit set, for inherited task events
4422 * will not be local and we cannot read them atomically
4423 * - must not have a pmu::count method
4425 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
4426 u64
*enabled
, u64
*running
)
4428 unsigned long flags
;
4432 * Disabling interrupts avoids all counter scheduling (context
4433 * switches, timer based rotation and IPIs).
4435 local_irq_save(flags
);
4438 * It must not be an event with inherit set, we cannot read
4439 * all child counters from atomic context.
4441 if (event
->attr
.inherit
) {
4446 /* If this is a per-task event, it must be for current */
4447 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
4448 event
->hw
.target
!= current
) {
4453 /* If this is a per-CPU event, it must be for this CPU */
4454 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
4455 event
->cpu
!= smp_processor_id()) {
4460 /* If this is a pinned event it must be running on this CPU */
4461 if (event
->attr
.pinned
&& event
->oncpu
!= smp_processor_id()) {
4467 * If the event is currently on this CPU, its either a per-task event,
4468 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
4471 if (event
->oncpu
== smp_processor_id())
4472 event
->pmu
->read(event
);
4474 *value
= local64_read(&event
->count
);
4475 if (enabled
|| running
) {
4476 u64 now
= event
->shadow_ctx_time
+ perf_clock();
4477 u64 __enabled
, __running
;
4479 __perf_update_times(event
, now
, &__enabled
, &__running
);
4481 *enabled
= __enabled
;
4483 *running
= __running
;
4486 local_irq_restore(flags
);
4491 static int perf_event_read(struct perf_event
*event
, bool group
)
4493 enum perf_event_state state
= READ_ONCE(event
->state
);
4494 int event_cpu
, ret
= 0;
4497 * If event is enabled and currently active on a CPU, update the
4498 * value in the event structure:
4501 if (state
== PERF_EVENT_STATE_ACTIVE
) {
4502 struct perf_read_data data
;
4505 * Orders the ->state and ->oncpu loads such that if we see
4506 * ACTIVE we must also see the right ->oncpu.
4508 * Matches the smp_wmb() from event_sched_in().
4512 event_cpu
= READ_ONCE(event
->oncpu
);
4513 if ((unsigned)event_cpu
>= nr_cpu_ids
)
4516 data
= (struct perf_read_data
){
4523 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
4526 * Purposely ignore the smp_call_function_single() return
4529 * If event_cpu isn't a valid CPU it means the event got
4530 * scheduled out and that will have updated the event count.
4532 * Therefore, either way, we'll have an up-to-date event count
4535 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
4539 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
4540 struct perf_event_context
*ctx
= event
->ctx
;
4541 unsigned long flags
;
4543 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4544 state
= event
->state
;
4545 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
4546 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4551 * May read while context is not active (e.g., thread is
4552 * blocked), in that case we cannot update context time
4554 if (ctx
->is_active
& EVENT_TIME
) {
4555 update_context_time(ctx
);
4556 update_cgrp_time_from_event(event
);
4559 perf_event_update_time(event
);
4561 perf_event_update_sibling_time(event
);
4562 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4569 * Initialize the perf_event context in a task_struct:
4571 static void __perf_event_init_context(struct perf_event_context
*ctx
)
4573 raw_spin_lock_init(&ctx
->lock
);
4574 mutex_init(&ctx
->mutex
);
4575 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
4576 perf_event_groups_init(&ctx
->pinned_groups
);
4577 perf_event_groups_init(&ctx
->flexible_groups
);
4578 INIT_LIST_HEAD(&ctx
->event_list
);
4579 INIT_LIST_HEAD(&ctx
->pinned_active
);
4580 INIT_LIST_HEAD(&ctx
->flexible_active
);
4581 refcount_set(&ctx
->refcount
, 1);
4584 static struct perf_event_context
*
4585 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
4587 struct perf_event_context
*ctx
;
4589 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
4593 __perf_event_init_context(ctx
);
4595 ctx
->task
= get_task_struct(task
);
4601 static struct task_struct
*
4602 find_lively_task_by_vpid(pid_t vpid
)
4604 struct task_struct
*task
;
4610 task
= find_task_by_vpid(vpid
);
4612 get_task_struct(task
);
4616 return ERR_PTR(-ESRCH
);
4622 * Returns a matching context with refcount and pincount.
4624 static struct perf_event_context
*
4625 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
4626 struct perf_event
*event
)
4628 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4629 struct perf_cpu_context
*cpuctx
;
4630 void *task_ctx_data
= NULL
;
4631 unsigned long flags
;
4633 int cpu
= event
->cpu
;
4636 /* Must be root to operate on a CPU event: */
4637 err
= perf_allow_cpu(&event
->attr
);
4639 return ERR_PTR(err
);
4641 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
4644 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4646 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4652 ctxn
= pmu
->task_ctx_nr
;
4656 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
4657 task_ctx_data
= alloc_task_ctx_data(pmu
);
4658 if (!task_ctx_data
) {
4665 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
4667 clone_ctx
= unclone_ctx(ctx
);
4670 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
4671 ctx
->task_ctx_data
= task_ctx_data
;
4672 task_ctx_data
= NULL
;
4674 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4679 ctx
= alloc_perf_context(pmu
, task
);
4684 if (task_ctx_data
) {
4685 ctx
->task_ctx_data
= task_ctx_data
;
4686 task_ctx_data
= NULL
;
4690 mutex_lock(&task
->perf_event_mutex
);
4692 * If it has already passed perf_event_exit_task().
4693 * we must see PF_EXITING, it takes this mutex too.
4695 if (task
->flags
& PF_EXITING
)
4697 else if (task
->perf_event_ctxp
[ctxn
])
4702 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
4704 mutex_unlock(&task
->perf_event_mutex
);
4706 if (unlikely(err
)) {
4715 free_task_ctx_data(pmu
, task_ctx_data
);
4719 free_task_ctx_data(pmu
, task_ctx_data
);
4720 return ERR_PTR(err
);
4723 static void perf_event_free_filter(struct perf_event
*event
);
4725 static void free_event_rcu(struct rcu_head
*head
)
4727 struct perf_event
*event
;
4729 event
= container_of(head
, struct perf_event
, rcu_head
);
4731 put_pid_ns(event
->ns
);
4732 perf_event_free_filter(event
);
4733 kmem_cache_free(perf_event_cache
, event
);
4736 static void ring_buffer_attach(struct perf_event
*event
,
4737 struct perf_buffer
*rb
);
4739 static void detach_sb_event(struct perf_event
*event
)
4741 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4743 raw_spin_lock(&pel
->lock
);
4744 list_del_rcu(&event
->sb_list
);
4745 raw_spin_unlock(&pel
->lock
);
4748 static bool is_sb_event(struct perf_event
*event
)
4750 struct perf_event_attr
*attr
= &event
->attr
;
4755 if (event
->attach_state
& PERF_ATTACH_TASK
)
4758 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4759 attr
->comm
|| attr
->comm_exec
||
4760 attr
->task
|| attr
->ksymbol
||
4761 attr
->context_switch
|| attr
->text_poke
||
4767 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4769 if (is_sb_event(event
))
4770 detach_sb_event(event
);
4773 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4778 if (is_cgroup_event(event
))
4779 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4782 #ifdef CONFIG_NO_HZ_FULL
4783 static DEFINE_SPINLOCK(nr_freq_lock
);
4786 static void unaccount_freq_event_nohz(void)
4788 #ifdef CONFIG_NO_HZ_FULL
4789 spin_lock(&nr_freq_lock
);
4790 if (atomic_dec_and_test(&nr_freq_events
))
4791 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4792 spin_unlock(&nr_freq_lock
);
4796 static void unaccount_freq_event(void)
4798 if (tick_nohz_full_enabled())
4799 unaccount_freq_event_nohz();
4801 atomic_dec(&nr_freq_events
);
4804 static void unaccount_event(struct perf_event
*event
)
4811 if (event
->attach_state
& (PERF_ATTACH_TASK
| PERF_ATTACH_SCHED_CB
))
4813 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4814 atomic_dec(&nr_mmap_events
);
4815 if (event
->attr
.build_id
)
4816 atomic_dec(&nr_build_id_events
);
4817 if (event
->attr
.comm
)
4818 atomic_dec(&nr_comm_events
);
4819 if (event
->attr
.namespaces
)
4820 atomic_dec(&nr_namespaces_events
);
4821 if (event
->attr
.cgroup
)
4822 atomic_dec(&nr_cgroup_events
);
4823 if (event
->attr
.task
)
4824 atomic_dec(&nr_task_events
);
4825 if (event
->attr
.freq
)
4826 unaccount_freq_event();
4827 if (event
->attr
.context_switch
) {
4829 atomic_dec(&nr_switch_events
);
4831 if (is_cgroup_event(event
))
4833 if (has_branch_stack(event
))
4835 if (event
->attr
.ksymbol
)
4836 atomic_dec(&nr_ksymbol_events
);
4837 if (event
->attr
.bpf_event
)
4838 atomic_dec(&nr_bpf_events
);
4839 if (event
->attr
.text_poke
)
4840 atomic_dec(&nr_text_poke_events
);
4843 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4844 schedule_delayed_work(&perf_sched_work
, HZ
);
4847 unaccount_event_cpu(event
, event
->cpu
);
4849 unaccount_pmu_sb_event(event
);
4852 static void perf_sched_delayed(struct work_struct
*work
)
4854 mutex_lock(&perf_sched_mutex
);
4855 if (atomic_dec_and_test(&perf_sched_count
))
4856 static_branch_disable(&perf_sched_events
);
4857 mutex_unlock(&perf_sched_mutex
);
4861 * The following implement mutual exclusion of events on "exclusive" pmus
4862 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4863 * at a time, so we disallow creating events that might conflict, namely:
4865 * 1) cpu-wide events in the presence of per-task events,
4866 * 2) per-task events in the presence of cpu-wide events,
4867 * 3) two matching events on the same context.
4869 * The former two cases are handled in the allocation path (perf_event_alloc(),
4870 * _free_event()), the latter -- before the first perf_install_in_context().
4872 static int exclusive_event_init(struct perf_event
*event
)
4874 struct pmu
*pmu
= event
->pmu
;
4876 if (!is_exclusive_pmu(pmu
))
4880 * Prevent co-existence of per-task and cpu-wide events on the
4881 * same exclusive pmu.
4883 * Negative pmu::exclusive_cnt means there are cpu-wide
4884 * events on this "exclusive" pmu, positive means there are
4887 * Since this is called in perf_event_alloc() path, event::ctx
4888 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4889 * to mean "per-task event", because unlike other attach states it
4890 * never gets cleared.
4892 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4893 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4896 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4903 static void exclusive_event_destroy(struct perf_event
*event
)
4905 struct pmu
*pmu
= event
->pmu
;
4907 if (!is_exclusive_pmu(pmu
))
4910 /* see comment in exclusive_event_init() */
4911 if (event
->attach_state
& PERF_ATTACH_TASK
)
4912 atomic_dec(&pmu
->exclusive_cnt
);
4914 atomic_inc(&pmu
->exclusive_cnt
);
4917 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4919 if ((e1
->pmu
== e2
->pmu
) &&
4920 (e1
->cpu
== e2
->cpu
||
4927 static bool exclusive_event_installable(struct perf_event
*event
,
4928 struct perf_event_context
*ctx
)
4930 struct perf_event
*iter_event
;
4931 struct pmu
*pmu
= event
->pmu
;
4933 lockdep_assert_held(&ctx
->mutex
);
4935 if (!is_exclusive_pmu(pmu
))
4938 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4939 if (exclusive_event_match(iter_event
, event
))
4946 static void perf_addr_filters_splice(struct perf_event
*event
,
4947 struct list_head
*head
);
4949 static void _free_event(struct perf_event
*event
)
4951 irq_work_sync(&event
->pending
);
4953 unaccount_event(event
);
4955 security_perf_event_free(event
);
4959 * Can happen when we close an event with re-directed output.
4961 * Since we have a 0 refcount, perf_mmap_close() will skip
4962 * over us; possibly making our ring_buffer_put() the last.
4964 mutex_lock(&event
->mmap_mutex
);
4965 ring_buffer_attach(event
, NULL
);
4966 mutex_unlock(&event
->mmap_mutex
);
4969 if (is_cgroup_event(event
))
4970 perf_detach_cgroup(event
);
4972 if (!event
->parent
) {
4973 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4974 put_callchain_buffers();
4977 perf_event_free_bpf_prog(event
);
4978 perf_addr_filters_splice(event
, NULL
);
4979 kfree(event
->addr_filter_ranges
);
4982 event
->destroy(event
);
4985 * Must be after ->destroy(), due to uprobe_perf_close() using
4988 if (event
->hw
.target
)
4989 put_task_struct(event
->hw
.target
);
4992 * perf_event_free_task() relies on put_ctx() being 'last', in particular
4993 * all task references must be cleaned up.
4996 put_ctx(event
->ctx
);
4998 exclusive_event_destroy(event
);
4999 module_put(event
->pmu
->module
);
5001 call_rcu(&event
->rcu_head
, free_event_rcu
);
5005 * Used to free events which have a known refcount of 1, such as in error paths
5006 * where the event isn't exposed yet and inherited events.
5008 static void free_event(struct perf_event
*event
)
5010 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
5011 "unexpected event refcount: %ld; ptr=%p\n",
5012 atomic_long_read(&event
->refcount
), event
)) {
5013 /* leak to avoid use-after-free */
5021 * Remove user event from the owner task.
5023 static void perf_remove_from_owner(struct perf_event
*event
)
5025 struct task_struct
*owner
;
5029 * Matches the smp_store_release() in perf_event_exit_task(). If we
5030 * observe !owner it means the list deletion is complete and we can
5031 * indeed free this event, otherwise we need to serialize on
5032 * owner->perf_event_mutex.
5034 owner
= READ_ONCE(event
->owner
);
5037 * Since delayed_put_task_struct() also drops the last
5038 * task reference we can safely take a new reference
5039 * while holding the rcu_read_lock().
5041 get_task_struct(owner
);
5047 * If we're here through perf_event_exit_task() we're already
5048 * holding ctx->mutex which would be an inversion wrt. the
5049 * normal lock order.
5051 * However we can safely take this lock because its the child
5054 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
5057 * We have to re-check the event->owner field, if it is cleared
5058 * we raced with perf_event_exit_task(), acquiring the mutex
5059 * ensured they're done, and we can proceed with freeing the
5063 list_del_init(&event
->owner_entry
);
5064 smp_store_release(&event
->owner
, NULL
);
5066 mutex_unlock(&owner
->perf_event_mutex
);
5067 put_task_struct(owner
);
5071 static void put_event(struct perf_event
*event
)
5073 if (!atomic_long_dec_and_test(&event
->refcount
))
5080 * Kill an event dead; while event:refcount will preserve the event
5081 * object, it will not preserve its functionality. Once the last 'user'
5082 * gives up the object, we'll destroy the thing.
5084 int perf_event_release_kernel(struct perf_event
*event
)
5086 struct perf_event_context
*ctx
= event
->ctx
;
5087 struct perf_event
*child
, *tmp
;
5088 LIST_HEAD(free_list
);
5091 * If we got here through err_file: fput(event_file); we will not have
5092 * attached to a context yet.
5095 WARN_ON_ONCE(event
->attach_state
&
5096 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
5100 if (!is_kernel_event(event
))
5101 perf_remove_from_owner(event
);
5103 ctx
= perf_event_ctx_lock(event
);
5104 WARN_ON_ONCE(ctx
->parent_ctx
);
5105 perf_remove_from_context(event
, DETACH_GROUP
);
5107 raw_spin_lock_irq(&ctx
->lock
);
5109 * Mark this event as STATE_DEAD, there is no external reference to it
5112 * Anybody acquiring event->child_mutex after the below loop _must_
5113 * also see this, most importantly inherit_event() which will avoid
5114 * placing more children on the list.
5116 * Thus this guarantees that we will in fact observe and kill _ALL_
5119 event
->state
= PERF_EVENT_STATE_DEAD
;
5120 raw_spin_unlock_irq(&ctx
->lock
);
5122 perf_event_ctx_unlock(event
, ctx
);
5125 mutex_lock(&event
->child_mutex
);
5126 list_for_each_entry(child
, &event
->child_list
, child_list
) {
5129 * Cannot change, child events are not migrated, see the
5130 * comment with perf_event_ctx_lock_nested().
5132 ctx
= READ_ONCE(child
->ctx
);
5134 * Since child_mutex nests inside ctx::mutex, we must jump
5135 * through hoops. We start by grabbing a reference on the ctx.
5137 * Since the event cannot get freed while we hold the
5138 * child_mutex, the context must also exist and have a !0
5144 * Now that we have a ctx ref, we can drop child_mutex, and
5145 * acquire ctx::mutex without fear of it going away. Then we
5146 * can re-acquire child_mutex.
5148 mutex_unlock(&event
->child_mutex
);
5149 mutex_lock(&ctx
->mutex
);
5150 mutex_lock(&event
->child_mutex
);
5153 * Now that we hold ctx::mutex and child_mutex, revalidate our
5154 * state, if child is still the first entry, it didn't get freed
5155 * and we can continue doing so.
5157 tmp
= list_first_entry_or_null(&event
->child_list
,
5158 struct perf_event
, child_list
);
5160 perf_remove_from_context(child
, DETACH_GROUP
);
5161 list_move(&child
->child_list
, &free_list
);
5163 * This matches the refcount bump in inherit_event();
5164 * this can't be the last reference.
5169 mutex_unlock(&event
->child_mutex
);
5170 mutex_unlock(&ctx
->mutex
);
5174 mutex_unlock(&event
->child_mutex
);
5176 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
5177 void *var
= &child
->ctx
->refcount
;
5179 list_del(&child
->child_list
);
5183 * Wake any perf_event_free_task() waiting for this event to be
5186 smp_mb(); /* pairs with wait_var_event() */
5191 put_event(event
); /* Must be the 'last' reference */
5194 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
5197 * Called when the last reference to the file is gone.
5199 static int perf_release(struct inode
*inode
, struct file
*file
)
5201 perf_event_release_kernel(file
->private_data
);
5205 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
5207 struct perf_event
*child
;
5213 mutex_lock(&event
->child_mutex
);
5215 (void)perf_event_read(event
, false);
5216 total
+= perf_event_count(event
);
5218 *enabled
+= event
->total_time_enabled
+
5219 atomic64_read(&event
->child_total_time_enabled
);
5220 *running
+= event
->total_time_running
+
5221 atomic64_read(&event
->child_total_time_running
);
5223 list_for_each_entry(child
, &event
->child_list
, child_list
) {
5224 (void)perf_event_read(child
, false);
5225 total
+= perf_event_count(child
);
5226 *enabled
+= child
->total_time_enabled
;
5227 *running
+= child
->total_time_running
;
5229 mutex_unlock(&event
->child_mutex
);
5234 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
5236 struct perf_event_context
*ctx
;
5239 ctx
= perf_event_ctx_lock(event
);
5240 count
= __perf_event_read_value(event
, enabled
, running
);
5241 perf_event_ctx_unlock(event
, ctx
);
5245 EXPORT_SYMBOL_GPL(perf_event_read_value
);
5247 static int __perf_read_group_add(struct perf_event
*leader
,
5248 u64 read_format
, u64
*values
)
5250 struct perf_event_context
*ctx
= leader
->ctx
;
5251 struct perf_event
*sub
;
5252 unsigned long flags
;
5253 int n
= 1; /* skip @nr */
5256 ret
= perf_event_read(leader
, true);
5260 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
5263 * Since we co-schedule groups, {enabled,running} times of siblings
5264 * will be identical to those of the leader, so we only publish one
5267 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5268 values
[n
++] += leader
->total_time_enabled
+
5269 atomic64_read(&leader
->child_total_time_enabled
);
5272 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5273 values
[n
++] += leader
->total_time_running
+
5274 atomic64_read(&leader
->child_total_time_running
);
5278 * Write {count,id} tuples for every sibling.
5280 values
[n
++] += perf_event_count(leader
);
5281 if (read_format
& PERF_FORMAT_ID
)
5282 values
[n
++] = primary_event_id(leader
);
5284 for_each_sibling_event(sub
, leader
) {
5285 values
[n
++] += perf_event_count(sub
);
5286 if (read_format
& PERF_FORMAT_ID
)
5287 values
[n
++] = primary_event_id(sub
);
5290 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
5294 static int perf_read_group(struct perf_event
*event
,
5295 u64 read_format
, char __user
*buf
)
5297 struct perf_event
*leader
= event
->group_leader
, *child
;
5298 struct perf_event_context
*ctx
= leader
->ctx
;
5302 lockdep_assert_held(&ctx
->mutex
);
5304 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
5308 values
[0] = 1 + leader
->nr_siblings
;
5311 * By locking the child_mutex of the leader we effectively
5312 * lock the child list of all siblings.. XXX explain how.
5314 mutex_lock(&leader
->child_mutex
);
5316 ret
= __perf_read_group_add(leader
, read_format
, values
);
5320 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
5321 ret
= __perf_read_group_add(child
, read_format
, values
);
5326 mutex_unlock(&leader
->child_mutex
);
5328 ret
= event
->read_size
;
5329 if (copy_to_user(buf
, values
, event
->read_size
))
5334 mutex_unlock(&leader
->child_mutex
);
5340 static int perf_read_one(struct perf_event
*event
,
5341 u64 read_format
, char __user
*buf
)
5343 u64 enabled
, running
;
5347 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
5348 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5349 values
[n
++] = enabled
;
5350 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5351 values
[n
++] = running
;
5352 if (read_format
& PERF_FORMAT_ID
)
5353 values
[n
++] = primary_event_id(event
);
5355 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
5358 return n
* sizeof(u64
);
5361 static bool is_event_hup(struct perf_event
*event
)
5365 if (event
->state
> PERF_EVENT_STATE_EXIT
)
5368 mutex_lock(&event
->child_mutex
);
5369 no_children
= list_empty(&event
->child_list
);
5370 mutex_unlock(&event
->child_mutex
);
5375 * Read the performance event - simple non blocking version for now
5378 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
5380 u64 read_format
= event
->attr
.read_format
;
5384 * Return end-of-file for a read on an event that is in
5385 * error state (i.e. because it was pinned but it couldn't be
5386 * scheduled on to the CPU at some point).
5388 if (event
->state
== PERF_EVENT_STATE_ERROR
)
5391 if (count
< event
->read_size
)
5394 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5395 if (read_format
& PERF_FORMAT_GROUP
)
5396 ret
= perf_read_group(event
, read_format
, buf
);
5398 ret
= perf_read_one(event
, read_format
, buf
);
5404 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
5406 struct perf_event
*event
= file
->private_data
;
5407 struct perf_event_context
*ctx
;
5410 ret
= security_perf_event_read(event
);
5414 ctx
= perf_event_ctx_lock(event
);
5415 ret
= __perf_read(event
, buf
, count
);
5416 perf_event_ctx_unlock(event
, ctx
);
5421 static __poll_t
perf_poll(struct file
*file
, poll_table
*wait
)
5423 struct perf_event
*event
= file
->private_data
;
5424 struct perf_buffer
*rb
;
5425 __poll_t events
= EPOLLHUP
;
5427 poll_wait(file
, &event
->waitq
, wait
);
5429 if (is_event_hup(event
))
5433 * Pin the event->rb by taking event->mmap_mutex; otherwise
5434 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
5436 mutex_lock(&event
->mmap_mutex
);
5439 events
= atomic_xchg(&rb
->poll
, 0);
5440 mutex_unlock(&event
->mmap_mutex
);
5444 static void _perf_event_reset(struct perf_event
*event
)
5446 (void)perf_event_read(event
, false);
5447 local64_set(&event
->count
, 0);
5448 perf_event_update_userpage(event
);
5451 /* Assume it's not an event with inherit set. */
5452 u64
perf_event_pause(struct perf_event
*event
, bool reset
)
5454 struct perf_event_context
*ctx
;
5457 ctx
= perf_event_ctx_lock(event
);
5458 WARN_ON_ONCE(event
->attr
.inherit
);
5459 _perf_event_disable(event
);
5460 count
= local64_read(&event
->count
);
5462 local64_set(&event
->count
, 0);
5463 perf_event_ctx_unlock(event
, ctx
);
5467 EXPORT_SYMBOL_GPL(perf_event_pause
);
5470 * Holding the top-level event's child_mutex means that any
5471 * descendant process that has inherited this event will block
5472 * in perf_event_exit_event() if it goes to exit, thus satisfying the
5473 * task existence requirements of perf_event_enable/disable.
5475 static void perf_event_for_each_child(struct perf_event
*event
,
5476 void (*func
)(struct perf_event
*))
5478 struct perf_event
*child
;
5480 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5482 mutex_lock(&event
->child_mutex
);
5484 list_for_each_entry(child
, &event
->child_list
, child_list
)
5486 mutex_unlock(&event
->child_mutex
);
5489 static void perf_event_for_each(struct perf_event
*event
,
5490 void (*func
)(struct perf_event
*))
5492 struct perf_event_context
*ctx
= event
->ctx
;
5493 struct perf_event
*sibling
;
5495 lockdep_assert_held(&ctx
->mutex
);
5497 event
= event
->group_leader
;
5499 perf_event_for_each_child(event
, func
);
5500 for_each_sibling_event(sibling
, event
)
5501 perf_event_for_each_child(sibling
, func
);
5504 static void __perf_event_period(struct perf_event
*event
,
5505 struct perf_cpu_context
*cpuctx
,
5506 struct perf_event_context
*ctx
,
5509 u64 value
= *((u64
*)info
);
5512 if (event
->attr
.freq
) {
5513 event
->attr
.sample_freq
= value
;
5515 event
->attr
.sample_period
= value
;
5516 event
->hw
.sample_period
= value
;
5519 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
5521 perf_pmu_disable(ctx
->pmu
);
5523 * We could be throttled; unthrottle now to avoid the tick
5524 * trying to unthrottle while we already re-started the event.
5526 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
5527 event
->hw
.interrupts
= 0;
5528 perf_log_throttle(event
, 1);
5530 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
5533 local64_set(&event
->hw
.period_left
, 0);
5536 event
->pmu
->start(event
, PERF_EF_RELOAD
);
5537 perf_pmu_enable(ctx
->pmu
);
5541 static int perf_event_check_period(struct perf_event
*event
, u64 value
)
5543 return event
->pmu
->check_period(event
, value
);
5546 static int _perf_event_period(struct perf_event
*event
, u64 value
)
5548 if (!is_sampling_event(event
))
5554 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
5557 if (perf_event_check_period(event
, value
))
5560 if (!event
->attr
.freq
&& (value
& (1ULL << 63)))
5563 event_function_call(event
, __perf_event_period
, &value
);
5568 int perf_event_period(struct perf_event
*event
, u64 value
)
5570 struct perf_event_context
*ctx
;
5573 ctx
= perf_event_ctx_lock(event
);
5574 ret
= _perf_event_period(event
, value
);
5575 perf_event_ctx_unlock(event
, ctx
);
5579 EXPORT_SYMBOL_GPL(perf_event_period
);
5581 static const struct file_operations perf_fops
;
5583 static inline int perf_fget_light(int fd
, struct fd
*p
)
5585 struct fd f
= fdget(fd
);
5589 if (f
.file
->f_op
!= &perf_fops
) {
5597 static int perf_event_set_output(struct perf_event
*event
,
5598 struct perf_event
*output_event
);
5599 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
5600 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5601 struct perf_event_attr
*attr
);
5603 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
5605 void (*func
)(struct perf_event
*);
5609 case PERF_EVENT_IOC_ENABLE
:
5610 func
= _perf_event_enable
;
5612 case PERF_EVENT_IOC_DISABLE
:
5613 func
= _perf_event_disable
;
5615 case PERF_EVENT_IOC_RESET
:
5616 func
= _perf_event_reset
;
5619 case PERF_EVENT_IOC_REFRESH
:
5620 return _perf_event_refresh(event
, arg
);
5622 case PERF_EVENT_IOC_PERIOD
:
5626 if (copy_from_user(&value
, (u64 __user
*)arg
, sizeof(value
)))
5629 return _perf_event_period(event
, value
);
5631 case PERF_EVENT_IOC_ID
:
5633 u64 id
= primary_event_id(event
);
5635 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
5640 case PERF_EVENT_IOC_SET_OUTPUT
:
5644 struct perf_event
*output_event
;
5646 ret
= perf_fget_light(arg
, &output
);
5649 output_event
= output
.file
->private_data
;
5650 ret
= perf_event_set_output(event
, output_event
);
5653 ret
= perf_event_set_output(event
, NULL
);
5658 case PERF_EVENT_IOC_SET_FILTER
:
5659 return perf_event_set_filter(event
, (void __user
*)arg
);
5661 case PERF_EVENT_IOC_SET_BPF
:
5663 struct bpf_prog
*prog
;
5666 prog
= bpf_prog_get(arg
);
5668 return PTR_ERR(prog
);
5670 err
= perf_event_set_bpf_prog(event
, prog
, 0);
5679 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
5680 struct perf_buffer
*rb
;
5683 rb
= rcu_dereference(event
->rb
);
5684 if (!rb
|| !rb
->nr_pages
) {
5688 rb_toggle_paused(rb
, !!arg
);
5693 case PERF_EVENT_IOC_QUERY_BPF
:
5694 return perf_event_query_prog_array(event
, (void __user
*)arg
);
5696 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES
: {
5697 struct perf_event_attr new_attr
;
5698 int err
= perf_copy_attr((struct perf_event_attr __user
*)arg
,
5704 return perf_event_modify_attr(event
, &new_attr
);
5710 if (flags
& PERF_IOC_FLAG_GROUP
)
5711 perf_event_for_each(event
, func
);
5713 perf_event_for_each_child(event
, func
);
5718 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
5720 struct perf_event
*event
= file
->private_data
;
5721 struct perf_event_context
*ctx
;
5724 /* Treat ioctl like writes as it is likely a mutating operation. */
5725 ret
= security_perf_event_write(event
);
5729 ctx
= perf_event_ctx_lock(event
);
5730 ret
= _perf_ioctl(event
, cmd
, arg
);
5731 perf_event_ctx_unlock(event
, ctx
);
5736 #ifdef CONFIG_COMPAT
5737 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
5740 switch (_IOC_NR(cmd
)) {
5741 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
5742 case _IOC_NR(PERF_EVENT_IOC_ID
):
5743 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF
):
5744 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES
):
5745 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5746 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
5747 cmd
&= ~IOCSIZE_MASK
;
5748 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
5752 return perf_ioctl(file
, cmd
, arg
);
5755 # define perf_compat_ioctl NULL
5758 int perf_event_task_enable(void)
5760 struct perf_event_context
*ctx
;
5761 struct perf_event
*event
;
5763 mutex_lock(¤t
->perf_event_mutex
);
5764 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5765 ctx
= perf_event_ctx_lock(event
);
5766 perf_event_for_each_child(event
, _perf_event_enable
);
5767 perf_event_ctx_unlock(event
, ctx
);
5769 mutex_unlock(¤t
->perf_event_mutex
);
5774 int perf_event_task_disable(void)
5776 struct perf_event_context
*ctx
;
5777 struct perf_event
*event
;
5779 mutex_lock(¤t
->perf_event_mutex
);
5780 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5781 ctx
= perf_event_ctx_lock(event
);
5782 perf_event_for_each_child(event
, _perf_event_disable
);
5783 perf_event_ctx_unlock(event
, ctx
);
5785 mutex_unlock(¤t
->perf_event_mutex
);
5790 static int perf_event_index(struct perf_event
*event
)
5792 if (event
->hw
.state
& PERF_HES_STOPPED
)
5795 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5798 return event
->pmu
->event_idx(event
);
5801 static void calc_timer_values(struct perf_event
*event
,
5808 *now
= perf_clock();
5809 ctx_time
= event
->shadow_ctx_time
+ *now
;
5810 __perf_update_times(event
, ctx_time
, enabled
, running
);
5813 static void perf_event_init_userpage(struct perf_event
*event
)
5815 struct perf_event_mmap_page
*userpg
;
5816 struct perf_buffer
*rb
;
5819 rb
= rcu_dereference(event
->rb
);
5823 userpg
= rb
->user_page
;
5825 /* Allow new userspace to detect that bit 0 is deprecated */
5826 userpg
->cap_bit0_is_deprecated
= 1;
5827 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
5828 userpg
->data_offset
= PAGE_SIZE
;
5829 userpg
->data_size
= perf_data_size(rb
);
5835 void __weak
arch_perf_update_userpage(
5836 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
5841 * Callers need to ensure there can be no nesting of this function, otherwise
5842 * the seqlock logic goes bad. We can not serialize this because the arch
5843 * code calls this from NMI context.
5845 void perf_event_update_userpage(struct perf_event
*event
)
5847 struct perf_event_mmap_page
*userpg
;
5848 struct perf_buffer
*rb
;
5849 u64 enabled
, running
, now
;
5852 rb
= rcu_dereference(event
->rb
);
5857 * compute total_time_enabled, total_time_running
5858 * based on snapshot values taken when the event
5859 * was last scheduled in.
5861 * we cannot simply called update_context_time()
5862 * because of locking issue as we can be called in
5865 calc_timer_values(event
, &now
, &enabled
, &running
);
5867 userpg
= rb
->user_page
;
5869 * Disable preemption to guarantee consistent time stamps are stored to
5875 userpg
->index
= perf_event_index(event
);
5876 userpg
->offset
= perf_event_count(event
);
5878 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5880 userpg
->time_enabled
= enabled
+
5881 atomic64_read(&event
->child_total_time_enabled
);
5883 userpg
->time_running
= running
+
5884 atomic64_read(&event
->child_total_time_running
);
5886 arch_perf_update_userpage(event
, userpg
, now
);
5894 EXPORT_SYMBOL_GPL(perf_event_update_userpage
);
5896 static vm_fault_t
perf_mmap_fault(struct vm_fault
*vmf
)
5898 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5899 struct perf_buffer
*rb
;
5900 vm_fault_t ret
= VM_FAULT_SIGBUS
;
5902 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5903 if (vmf
->pgoff
== 0)
5909 rb
= rcu_dereference(event
->rb
);
5913 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5916 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5920 get_page(vmf
->page
);
5921 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5922 vmf
->page
->index
= vmf
->pgoff
;
5931 static void ring_buffer_attach(struct perf_event
*event
,
5932 struct perf_buffer
*rb
)
5934 struct perf_buffer
*old_rb
= NULL
;
5935 unsigned long flags
;
5939 * Should be impossible, we set this when removing
5940 * event->rb_entry and wait/clear when adding event->rb_entry.
5942 WARN_ON_ONCE(event
->rcu_pending
);
5945 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5946 list_del_rcu(&event
->rb_entry
);
5947 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5949 event
->rcu_batches
= get_state_synchronize_rcu();
5950 event
->rcu_pending
= 1;
5954 if (event
->rcu_pending
) {
5955 cond_synchronize_rcu(event
->rcu_batches
);
5956 event
->rcu_pending
= 0;
5959 spin_lock_irqsave(&rb
->event_lock
, flags
);
5960 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5961 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5965 * Avoid racing with perf_mmap_close(AUX): stop the event
5966 * before swizzling the event::rb pointer; if it's getting
5967 * unmapped, its aux_mmap_count will be 0 and it won't
5968 * restart. See the comment in __perf_pmu_output_stop().
5970 * Data will inevitably be lost when set_output is done in
5971 * mid-air, but then again, whoever does it like this is
5972 * not in for the data anyway.
5975 perf_event_stop(event
, 0);
5977 rcu_assign_pointer(event
->rb
, rb
);
5980 ring_buffer_put(old_rb
);
5982 * Since we detached before setting the new rb, so that we
5983 * could attach the new rb, we could have missed a wakeup.
5986 wake_up_all(&event
->waitq
);
5990 static void ring_buffer_wakeup(struct perf_event
*event
)
5992 struct perf_buffer
*rb
;
5995 rb
= rcu_dereference(event
->rb
);
5997 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5998 wake_up_all(&event
->waitq
);
6003 struct perf_buffer
*ring_buffer_get(struct perf_event
*event
)
6005 struct perf_buffer
*rb
;
6008 rb
= rcu_dereference(event
->rb
);
6010 if (!refcount_inc_not_zero(&rb
->refcount
))
6018 void ring_buffer_put(struct perf_buffer
*rb
)
6020 if (!refcount_dec_and_test(&rb
->refcount
))
6023 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
6025 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
6028 static void perf_mmap_open(struct vm_area_struct
*vma
)
6030 struct perf_event
*event
= vma
->vm_file
->private_data
;
6032 atomic_inc(&event
->mmap_count
);
6033 atomic_inc(&event
->rb
->mmap_count
);
6036 atomic_inc(&event
->rb
->aux_mmap_count
);
6038 if (event
->pmu
->event_mapped
)
6039 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
6042 static void perf_pmu_output_stop(struct perf_event
*event
);
6045 * A buffer can be mmap()ed multiple times; either directly through the same
6046 * event, or through other events by use of perf_event_set_output().
6048 * In order to undo the VM accounting done by perf_mmap() we need to destroy
6049 * the buffer here, where we still have a VM context. This means we need
6050 * to detach all events redirecting to us.
6052 static void perf_mmap_close(struct vm_area_struct
*vma
)
6054 struct perf_event
*event
= vma
->vm_file
->private_data
;
6055 struct perf_buffer
*rb
= ring_buffer_get(event
);
6056 struct user_struct
*mmap_user
= rb
->mmap_user
;
6057 int mmap_locked
= rb
->mmap_locked
;
6058 unsigned long size
= perf_data_size(rb
);
6059 bool detach_rest
= false;
6061 if (event
->pmu
->event_unmapped
)
6062 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
6065 * rb->aux_mmap_count will always drop before rb->mmap_count and
6066 * event->mmap_count, so it is ok to use event->mmap_mutex to
6067 * serialize with perf_mmap here.
6069 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
6070 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
6072 * Stop all AUX events that are writing to this buffer,
6073 * so that we can free its AUX pages and corresponding PMU
6074 * data. Note that after rb::aux_mmap_count dropped to zero,
6075 * they won't start any more (see perf_aux_output_begin()).
6077 perf_pmu_output_stop(event
);
6079 /* now it's safe to free the pages */
6080 atomic_long_sub(rb
->aux_nr_pages
- rb
->aux_mmap_locked
, &mmap_user
->locked_vm
);
6081 atomic64_sub(rb
->aux_mmap_locked
, &vma
->vm_mm
->pinned_vm
);
6083 /* this has to be the last one */
6085 WARN_ON_ONCE(refcount_read(&rb
->aux_refcount
));
6087 mutex_unlock(&event
->mmap_mutex
);
6090 if (atomic_dec_and_test(&rb
->mmap_count
))
6093 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
6096 ring_buffer_attach(event
, NULL
);
6097 mutex_unlock(&event
->mmap_mutex
);
6099 /* If there's still other mmap()s of this buffer, we're done. */
6104 * No other mmap()s, detach from all other events that might redirect
6105 * into the now unreachable buffer. Somewhat complicated by the
6106 * fact that rb::event_lock otherwise nests inside mmap_mutex.
6110 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
6111 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
6113 * This event is en-route to free_event() which will
6114 * detach it and remove it from the list.
6120 mutex_lock(&event
->mmap_mutex
);
6122 * Check we didn't race with perf_event_set_output() which can
6123 * swizzle the rb from under us while we were waiting to
6124 * acquire mmap_mutex.
6126 * If we find a different rb; ignore this event, a next
6127 * iteration will no longer find it on the list. We have to
6128 * still restart the iteration to make sure we're not now
6129 * iterating the wrong list.
6131 if (event
->rb
== rb
)
6132 ring_buffer_attach(event
, NULL
);
6134 mutex_unlock(&event
->mmap_mutex
);
6138 * Restart the iteration; either we're on the wrong list or
6139 * destroyed its integrity by doing a deletion.
6146 * It could be there's still a few 0-ref events on the list; they'll
6147 * get cleaned up by free_event() -- they'll also still have their
6148 * ref on the rb and will free it whenever they are done with it.
6150 * Aside from that, this buffer is 'fully' detached and unmapped,
6151 * undo the VM accounting.
6154 atomic_long_sub((size
>> PAGE_SHIFT
) + 1 - mmap_locked
,
6155 &mmap_user
->locked_vm
);
6156 atomic64_sub(mmap_locked
, &vma
->vm_mm
->pinned_vm
);
6157 free_uid(mmap_user
);
6160 ring_buffer_put(rb
); /* could be last */
6163 static const struct vm_operations_struct perf_mmap_vmops
= {
6164 .open
= perf_mmap_open
,
6165 .close
= perf_mmap_close
, /* non mergeable */
6166 .fault
= perf_mmap_fault
,
6167 .page_mkwrite
= perf_mmap_fault
,
6170 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
6172 struct perf_event
*event
= file
->private_data
;
6173 unsigned long user_locked
, user_lock_limit
;
6174 struct user_struct
*user
= current_user();
6175 struct perf_buffer
*rb
= NULL
;
6176 unsigned long locked
, lock_limit
;
6177 unsigned long vma_size
;
6178 unsigned long nr_pages
;
6179 long user_extra
= 0, extra
= 0;
6180 int ret
= 0, flags
= 0;
6183 * Don't allow mmap() of inherited per-task counters. This would
6184 * create a performance issue due to all children writing to the
6187 if (event
->cpu
== -1 && event
->attr
.inherit
)
6190 if (!(vma
->vm_flags
& VM_SHARED
))
6193 ret
= security_perf_event_read(event
);
6197 vma_size
= vma
->vm_end
- vma
->vm_start
;
6199 if (vma
->vm_pgoff
== 0) {
6200 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
6203 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
6204 * mapped, all subsequent mappings should have the same size
6205 * and offset. Must be above the normal perf buffer.
6207 u64 aux_offset
, aux_size
;
6212 nr_pages
= vma_size
/ PAGE_SIZE
;
6214 mutex_lock(&event
->mmap_mutex
);
6221 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
6222 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
6224 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
6227 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
6230 /* already mapped with a different offset */
6231 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
6234 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
6237 /* already mapped with a different size */
6238 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
6241 if (!is_power_of_2(nr_pages
))
6244 if (!atomic_inc_not_zero(&rb
->mmap_count
))
6247 if (rb_has_aux(rb
)) {
6248 atomic_inc(&rb
->aux_mmap_count
);
6253 atomic_set(&rb
->aux_mmap_count
, 1);
6254 user_extra
= nr_pages
;
6260 * If we have rb pages ensure they're a power-of-two number, so we
6261 * can do bitmasks instead of modulo.
6263 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
6266 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
6269 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
6271 mutex_lock(&event
->mmap_mutex
);
6273 if (event
->rb
->nr_pages
!= nr_pages
) {
6278 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
6280 * Raced against perf_mmap_close() through
6281 * perf_event_set_output(). Try again, hope for better
6284 mutex_unlock(&event
->mmap_mutex
);
6291 user_extra
= nr_pages
+ 1;
6294 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
6297 * Increase the limit linearly with more CPUs:
6299 user_lock_limit
*= num_online_cpus();
6301 user_locked
= atomic_long_read(&user
->locked_vm
);
6304 * sysctl_perf_event_mlock may have changed, so that
6305 * user->locked_vm > user_lock_limit
6307 if (user_locked
> user_lock_limit
)
6308 user_locked
= user_lock_limit
;
6309 user_locked
+= user_extra
;
6311 if (user_locked
> user_lock_limit
) {
6313 * charge locked_vm until it hits user_lock_limit;
6314 * charge the rest from pinned_vm
6316 extra
= user_locked
- user_lock_limit
;
6317 user_extra
-= extra
;
6320 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
6321 lock_limit
>>= PAGE_SHIFT
;
6322 locked
= atomic64_read(&vma
->vm_mm
->pinned_vm
) + extra
;
6324 if ((locked
> lock_limit
) && perf_is_paranoid() &&
6325 !capable(CAP_IPC_LOCK
)) {
6330 WARN_ON(!rb
&& event
->rb
);
6332 if (vma
->vm_flags
& VM_WRITE
)
6333 flags
|= RING_BUFFER_WRITABLE
;
6336 rb
= rb_alloc(nr_pages
,
6337 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
6345 atomic_set(&rb
->mmap_count
, 1);
6346 rb
->mmap_user
= get_current_user();
6347 rb
->mmap_locked
= extra
;
6349 ring_buffer_attach(event
, rb
);
6351 perf_event_update_time(event
);
6352 perf_set_shadow_time(event
, event
->ctx
);
6353 perf_event_init_userpage(event
);
6354 perf_event_update_userpage(event
);
6356 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
6357 event
->attr
.aux_watermark
, flags
);
6359 rb
->aux_mmap_locked
= extra
;
6364 atomic_long_add(user_extra
, &user
->locked_vm
);
6365 atomic64_add(extra
, &vma
->vm_mm
->pinned_vm
);
6367 atomic_inc(&event
->mmap_count
);
6369 atomic_dec(&rb
->mmap_count
);
6372 mutex_unlock(&event
->mmap_mutex
);
6375 * Since pinned accounting is per vm we cannot allow fork() to copy our
6378 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
6379 vma
->vm_ops
= &perf_mmap_vmops
;
6381 if (event
->pmu
->event_mapped
)
6382 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
6387 static int perf_fasync(int fd
, struct file
*filp
, int on
)
6389 struct inode
*inode
= file_inode(filp
);
6390 struct perf_event
*event
= filp
->private_data
;
6394 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
6395 inode_unlock(inode
);
6403 static const struct file_operations perf_fops
= {
6404 .llseek
= no_llseek
,
6405 .release
= perf_release
,
6408 .unlocked_ioctl
= perf_ioctl
,
6409 .compat_ioctl
= perf_compat_ioctl
,
6411 .fasync
= perf_fasync
,
6417 * If there's data, ensure we set the poll() state and publish everything
6418 * to user-space before waking everybody up.
6421 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
6423 /* only the parent has fasync state */
6425 event
= event
->parent
;
6426 return &event
->fasync
;
6429 void perf_event_wakeup(struct perf_event
*event
)
6431 ring_buffer_wakeup(event
);
6433 if (event
->pending_kill
) {
6434 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
6435 event
->pending_kill
= 0;
6439 static void perf_sigtrap(struct perf_event
*event
)
6442 * We'd expect this to only occur if the irq_work is delayed and either
6443 * ctx->task or current has changed in the meantime. This can be the
6444 * case on architectures that do not implement arch_irq_work_raise().
6446 if (WARN_ON_ONCE(event
->ctx
->task
!= current
))
6450 * perf_pending_event() can race with the task exiting.
6452 if (current
->flags
& PF_EXITING
)
6455 force_sig_perf((void __user
*)event
->pending_addr
,
6456 event
->attr
.type
, event
->attr
.sig_data
);
6459 static void perf_pending_event_disable(struct perf_event
*event
)
6461 int cpu
= READ_ONCE(event
->pending_disable
);
6466 if (cpu
== smp_processor_id()) {
6467 WRITE_ONCE(event
->pending_disable
, -1);
6469 if (event
->attr
.sigtrap
) {
6470 perf_sigtrap(event
);
6471 atomic_set_release(&event
->event_limit
, 1); /* rearm event */
6475 perf_event_disable_local(event
);
6482 * perf_event_disable_inatomic()
6483 * @pending_disable = CPU-A;
6487 * @pending_disable = -1;
6490 * perf_event_disable_inatomic()
6491 * @pending_disable = CPU-B;
6492 * irq_work_queue(); // FAILS
6495 * perf_pending_event()
6497 * But the event runs on CPU-B and wants disabling there.
6499 irq_work_queue_on(&event
->pending
, cpu
);
6502 static void perf_pending_event(struct irq_work
*entry
)
6504 struct perf_event
*event
= container_of(entry
, struct perf_event
, pending
);
6507 rctx
= perf_swevent_get_recursion_context();
6509 * If we 'fail' here, that's OK, it means recursion is already disabled
6510 * and we won't recurse 'further'.
6513 perf_pending_event_disable(event
);
6515 if (event
->pending_wakeup
) {
6516 event
->pending_wakeup
= 0;
6517 perf_event_wakeup(event
);
6521 perf_swevent_put_recursion_context(rctx
);
6525 * We assume there is only KVM supporting the callbacks.
6526 * Later on, we might change it to a list if there is
6527 * another virtualization implementation supporting the callbacks.
6529 struct perf_guest_info_callbacks
*perf_guest_cbs
;
6531 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6533 perf_guest_cbs
= cbs
;
6536 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
6538 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6540 perf_guest_cbs
= NULL
;
6543 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
6546 perf_output_sample_regs(struct perf_output_handle
*handle
,
6547 struct pt_regs
*regs
, u64 mask
)
6550 DECLARE_BITMAP(_mask
, 64);
6552 bitmap_from_u64(_mask
, mask
);
6553 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
6556 val
= perf_reg_value(regs
, bit
);
6557 perf_output_put(handle
, val
);
6561 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
6562 struct pt_regs
*regs
)
6564 if (user_mode(regs
)) {
6565 regs_user
->abi
= perf_reg_abi(current
);
6566 regs_user
->regs
= regs
;
6567 } else if (!(current
->flags
& PF_KTHREAD
)) {
6568 perf_get_regs_user(regs_user
, regs
);
6570 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
6571 regs_user
->regs
= NULL
;
6575 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
6576 struct pt_regs
*regs
)
6578 regs_intr
->regs
= regs
;
6579 regs_intr
->abi
= perf_reg_abi(current
);
6584 * Get remaining task size from user stack pointer.
6586 * It'd be better to take stack vma map and limit this more
6587 * precisely, but there's no way to get it safely under interrupt,
6588 * so using TASK_SIZE as limit.
6590 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
6592 unsigned long addr
= perf_user_stack_pointer(regs
);
6594 if (!addr
|| addr
>= TASK_SIZE
)
6597 return TASK_SIZE
- addr
;
6601 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
6602 struct pt_regs
*regs
)
6606 /* No regs, no stack pointer, no dump. */
6611 * Check if we fit in with the requested stack size into the:
6613 * If we don't, we limit the size to the TASK_SIZE.
6615 * - remaining sample size
6616 * If we don't, we customize the stack size to
6617 * fit in to the remaining sample size.
6620 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
6621 stack_size
= min(stack_size
, (u16
) task_size
);
6623 /* Current header size plus static size and dynamic size. */
6624 header_size
+= 2 * sizeof(u64
);
6626 /* Do we fit in with the current stack dump size? */
6627 if ((u16
) (header_size
+ stack_size
) < header_size
) {
6629 * If we overflow the maximum size for the sample,
6630 * we customize the stack dump size to fit in.
6632 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
6633 stack_size
= round_up(stack_size
, sizeof(u64
));
6640 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
6641 struct pt_regs
*regs
)
6643 /* Case of a kernel thread, nothing to dump */
6646 perf_output_put(handle
, size
);
6656 * - the size requested by user or the best one we can fit
6657 * in to the sample max size
6659 * - user stack dump data
6661 * - the actual dumped size
6665 perf_output_put(handle
, dump_size
);
6668 sp
= perf_user_stack_pointer(regs
);
6669 fs
= force_uaccess_begin();
6670 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
6671 force_uaccess_end(fs
);
6672 dyn_size
= dump_size
- rem
;
6674 perf_output_skip(handle
, rem
);
6677 perf_output_put(handle
, dyn_size
);
6681 static unsigned long perf_prepare_sample_aux(struct perf_event
*event
,
6682 struct perf_sample_data
*data
,
6685 struct perf_event
*sampler
= event
->aux_event
;
6686 struct perf_buffer
*rb
;
6693 if (WARN_ON_ONCE(READ_ONCE(sampler
->state
) != PERF_EVENT_STATE_ACTIVE
))
6696 if (WARN_ON_ONCE(READ_ONCE(sampler
->oncpu
) != smp_processor_id()))
6699 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6704 * If this is an NMI hit inside sampling code, don't take
6705 * the sample. See also perf_aux_sample_output().
6707 if (READ_ONCE(rb
->aux_in_sampling
)) {
6710 size
= min_t(size_t, size
, perf_aux_size(rb
));
6711 data
->aux_size
= ALIGN(size
, sizeof(u64
));
6713 ring_buffer_put(rb
);
6716 return data
->aux_size
;
6719 static long perf_pmu_snapshot_aux(struct perf_buffer
*rb
,
6720 struct perf_event
*event
,
6721 struct perf_output_handle
*handle
,
6724 unsigned long flags
;
6728 * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
6729 * paths. If we start calling them in NMI context, they may race with
6730 * the IRQ ones, that is, for example, re-starting an event that's just
6731 * been stopped, which is why we're using a separate callback that
6732 * doesn't change the event state.
6734 * IRQs need to be disabled to prevent IPIs from racing with us.
6736 local_irq_save(flags
);
6738 * Guard against NMI hits inside the critical section;
6739 * see also perf_prepare_sample_aux().
6741 WRITE_ONCE(rb
->aux_in_sampling
, 1);
6744 ret
= event
->pmu
->snapshot_aux(event
, handle
, size
);
6747 WRITE_ONCE(rb
->aux_in_sampling
, 0);
6748 local_irq_restore(flags
);
6753 static void perf_aux_sample_output(struct perf_event
*event
,
6754 struct perf_output_handle
*handle
,
6755 struct perf_sample_data
*data
)
6757 struct perf_event
*sampler
= event
->aux_event
;
6758 struct perf_buffer
*rb
;
6762 if (WARN_ON_ONCE(!sampler
|| !data
->aux_size
))
6765 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6769 size
= perf_pmu_snapshot_aux(rb
, sampler
, handle
, data
->aux_size
);
6772 * An error here means that perf_output_copy() failed (returned a
6773 * non-zero surplus that it didn't copy), which in its current
6774 * enlightened implementation is not possible. If that changes, we'd
6777 if (WARN_ON_ONCE(size
< 0))
6781 * The pad comes from ALIGN()ing data->aux_size up to u64 in
6782 * perf_prepare_sample_aux(), so should not be more than that.
6784 pad
= data
->aux_size
- size
;
6785 if (WARN_ON_ONCE(pad
>= sizeof(u64
)))
6790 perf_output_copy(handle
, &zero
, pad
);
6794 ring_buffer_put(rb
);
6797 static void __perf_event_header__init_id(struct perf_event_header
*header
,
6798 struct perf_sample_data
*data
,
6799 struct perf_event
*event
)
6801 u64 sample_type
= event
->attr
.sample_type
;
6803 data
->type
= sample_type
;
6804 header
->size
+= event
->id_header_size
;
6806 if (sample_type
& PERF_SAMPLE_TID
) {
6807 /* namespace issues */
6808 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
6809 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
6812 if (sample_type
& PERF_SAMPLE_TIME
)
6813 data
->time
= perf_event_clock(event
);
6815 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
6816 data
->id
= primary_event_id(event
);
6818 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6819 data
->stream_id
= event
->id
;
6821 if (sample_type
& PERF_SAMPLE_CPU
) {
6822 data
->cpu_entry
.cpu
= raw_smp_processor_id();
6823 data
->cpu_entry
.reserved
= 0;
6827 void perf_event_header__init_id(struct perf_event_header
*header
,
6828 struct perf_sample_data
*data
,
6829 struct perf_event
*event
)
6831 if (event
->attr
.sample_id_all
)
6832 __perf_event_header__init_id(header
, data
, event
);
6835 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
6836 struct perf_sample_data
*data
)
6838 u64 sample_type
= data
->type
;
6840 if (sample_type
& PERF_SAMPLE_TID
)
6841 perf_output_put(handle
, data
->tid_entry
);
6843 if (sample_type
& PERF_SAMPLE_TIME
)
6844 perf_output_put(handle
, data
->time
);
6846 if (sample_type
& PERF_SAMPLE_ID
)
6847 perf_output_put(handle
, data
->id
);
6849 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6850 perf_output_put(handle
, data
->stream_id
);
6852 if (sample_type
& PERF_SAMPLE_CPU
)
6853 perf_output_put(handle
, data
->cpu_entry
);
6855 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6856 perf_output_put(handle
, data
->id
);
6859 void perf_event__output_id_sample(struct perf_event
*event
,
6860 struct perf_output_handle
*handle
,
6861 struct perf_sample_data
*sample
)
6863 if (event
->attr
.sample_id_all
)
6864 __perf_event__output_id_sample(handle
, sample
);
6867 static void perf_output_read_one(struct perf_output_handle
*handle
,
6868 struct perf_event
*event
,
6869 u64 enabled
, u64 running
)
6871 u64 read_format
= event
->attr
.read_format
;
6875 values
[n
++] = perf_event_count(event
);
6876 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
6877 values
[n
++] = enabled
+
6878 atomic64_read(&event
->child_total_time_enabled
);
6880 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
6881 values
[n
++] = running
+
6882 atomic64_read(&event
->child_total_time_running
);
6884 if (read_format
& PERF_FORMAT_ID
)
6885 values
[n
++] = primary_event_id(event
);
6887 __output_copy(handle
, values
, n
* sizeof(u64
));
6890 static void perf_output_read_group(struct perf_output_handle
*handle
,
6891 struct perf_event
*event
,
6892 u64 enabled
, u64 running
)
6894 struct perf_event
*leader
= event
->group_leader
, *sub
;
6895 u64 read_format
= event
->attr
.read_format
;
6899 values
[n
++] = 1 + leader
->nr_siblings
;
6901 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
6902 values
[n
++] = enabled
;
6904 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
6905 values
[n
++] = running
;
6907 if ((leader
!= event
) &&
6908 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
6909 leader
->pmu
->read(leader
);
6911 values
[n
++] = perf_event_count(leader
);
6912 if (read_format
& PERF_FORMAT_ID
)
6913 values
[n
++] = primary_event_id(leader
);
6915 __output_copy(handle
, values
, n
* sizeof(u64
));
6917 for_each_sibling_event(sub
, leader
) {
6920 if ((sub
!= event
) &&
6921 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
6922 sub
->pmu
->read(sub
);
6924 values
[n
++] = perf_event_count(sub
);
6925 if (read_format
& PERF_FORMAT_ID
)
6926 values
[n
++] = primary_event_id(sub
);
6928 __output_copy(handle
, values
, n
* sizeof(u64
));
6932 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
6933 PERF_FORMAT_TOTAL_TIME_RUNNING)
6936 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
6938 * The problem is that its both hard and excessively expensive to iterate the
6939 * child list, not to mention that its impossible to IPI the children running
6940 * on another CPU, from interrupt/NMI context.
6942 static void perf_output_read(struct perf_output_handle
*handle
,
6943 struct perf_event
*event
)
6945 u64 enabled
= 0, running
= 0, now
;
6946 u64 read_format
= event
->attr
.read_format
;
6949 * compute total_time_enabled, total_time_running
6950 * based on snapshot values taken when the event
6951 * was last scheduled in.
6953 * we cannot simply called update_context_time()
6954 * because of locking issue as we are called in
6957 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
6958 calc_timer_values(event
, &now
, &enabled
, &running
);
6960 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
6961 perf_output_read_group(handle
, event
, enabled
, running
);
6963 perf_output_read_one(handle
, event
, enabled
, running
);
6966 static inline bool perf_sample_save_hw_index(struct perf_event
*event
)
6968 return event
->attr
.branch_sample_type
& PERF_SAMPLE_BRANCH_HW_INDEX
;
6971 void perf_output_sample(struct perf_output_handle
*handle
,
6972 struct perf_event_header
*header
,
6973 struct perf_sample_data
*data
,
6974 struct perf_event
*event
)
6976 u64 sample_type
= data
->type
;
6978 perf_output_put(handle
, *header
);
6980 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6981 perf_output_put(handle
, data
->id
);
6983 if (sample_type
& PERF_SAMPLE_IP
)
6984 perf_output_put(handle
, data
->ip
);
6986 if (sample_type
& PERF_SAMPLE_TID
)
6987 perf_output_put(handle
, data
->tid_entry
);
6989 if (sample_type
& PERF_SAMPLE_TIME
)
6990 perf_output_put(handle
, data
->time
);
6992 if (sample_type
& PERF_SAMPLE_ADDR
)
6993 perf_output_put(handle
, data
->addr
);
6995 if (sample_type
& PERF_SAMPLE_ID
)
6996 perf_output_put(handle
, data
->id
);
6998 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6999 perf_output_put(handle
, data
->stream_id
);
7001 if (sample_type
& PERF_SAMPLE_CPU
)
7002 perf_output_put(handle
, data
->cpu_entry
);
7004 if (sample_type
& PERF_SAMPLE_PERIOD
)
7005 perf_output_put(handle
, data
->period
);
7007 if (sample_type
& PERF_SAMPLE_READ
)
7008 perf_output_read(handle
, event
);
7010 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7013 size
+= data
->callchain
->nr
;
7014 size
*= sizeof(u64
);
7015 __output_copy(handle
, data
->callchain
, size
);
7018 if (sample_type
& PERF_SAMPLE_RAW
) {
7019 struct perf_raw_record
*raw
= data
->raw
;
7022 struct perf_raw_frag
*frag
= &raw
->frag
;
7024 perf_output_put(handle
, raw
->size
);
7027 __output_custom(handle
, frag
->copy
,
7028 frag
->data
, frag
->size
);
7030 __output_copy(handle
, frag
->data
,
7033 if (perf_raw_frag_last(frag
))
7038 __output_skip(handle
, NULL
, frag
->pad
);
7044 .size
= sizeof(u32
),
7047 perf_output_put(handle
, raw
);
7051 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7052 if (data
->br_stack
) {
7055 size
= data
->br_stack
->nr
7056 * sizeof(struct perf_branch_entry
);
7058 perf_output_put(handle
, data
->br_stack
->nr
);
7059 if (perf_sample_save_hw_index(event
))
7060 perf_output_put(handle
, data
->br_stack
->hw_idx
);
7061 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
7064 * we always store at least the value of nr
7067 perf_output_put(handle
, nr
);
7071 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
7072 u64 abi
= data
->regs_user
.abi
;
7075 * If there are no regs to dump, notice it through
7076 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
7078 perf_output_put(handle
, abi
);
7081 u64 mask
= event
->attr
.sample_regs_user
;
7082 perf_output_sample_regs(handle
,
7083 data
->regs_user
.regs
,
7088 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
7089 perf_output_sample_ustack(handle
,
7090 data
->stack_user_size
,
7091 data
->regs_user
.regs
);
7094 if (sample_type
& PERF_SAMPLE_WEIGHT_TYPE
)
7095 perf_output_put(handle
, data
->weight
.full
);
7097 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
7098 perf_output_put(handle
, data
->data_src
.val
);
7100 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
7101 perf_output_put(handle
, data
->txn
);
7103 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
7104 u64 abi
= data
->regs_intr
.abi
;
7106 * If there are no regs to dump, notice it through
7107 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
7109 perf_output_put(handle
, abi
);
7112 u64 mask
= event
->attr
.sample_regs_intr
;
7114 perf_output_sample_regs(handle
,
7115 data
->regs_intr
.regs
,
7120 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
7121 perf_output_put(handle
, data
->phys_addr
);
7123 if (sample_type
& PERF_SAMPLE_CGROUP
)
7124 perf_output_put(handle
, data
->cgroup
);
7126 if (sample_type
& PERF_SAMPLE_DATA_PAGE_SIZE
)
7127 perf_output_put(handle
, data
->data_page_size
);
7129 if (sample_type
& PERF_SAMPLE_CODE_PAGE_SIZE
)
7130 perf_output_put(handle
, data
->code_page_size
);
7132 if (sample_type
& PERF_SAMPLE_AUX
) {
7133 perf_output_put(handle
, data
->aux_size
);
7136 perf_aux_sample_output(event
, handle
, data
);
7139 if (!event
->attr
.watermark
) {
7140 int wakeup_events
= event
->attr
.wakeup_events
;
7142 if (wakeup_events
) {
7143 struct perf_buffer
*rb
= handle
->rb
;
7144 int events
= local_inc_return(&rb
->events
);
7146 if (events
>= wakeup_events
) {
7147 local_sub(wakeup_events
, &rb
->events
);
7148 local_inc(&rb
->wakeup
);
7154 static u64
perf_virt_to_phys(u64 virt
)
7157 struct page
*p
= NULL
;
7162 if (virt
>= TASK_SIZE
) {
7163 /* If it's vmalloc()d memory, leave phys_addr as 0 */
7164 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
7165 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
7166 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
7169 * Walking the pages tables for user address.
7170 * Interrupts are disabled, so it prevents any tear down
7171 * of the page tables.
7172 * Try IRQ-safe get_user_page_fast_only first.
7173 * If failed, leave phys_addr as 0.
7175 if (current
->mm
!= NULL
) {
7176 pagefault_disable();
7177 if (get_user_page_fast_only(virt
, 0, &p
))
7178 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
7190 * Return the pagetable size of a given virtual address.
7192 static u64
perf_get_pgtable_size(struct mm_struct
*mm
, unsigned long addr
)
7196 #ifdef CONFIG_HAVE_FAST_GUP
7203 pgdp
= pgd_offset(mm
, addr
);
7204 pgd
= READ_ONCE(*pgdp
);
7209 return pgd_leaf_size(pgd
);
7211 p4dp
= p4d_offset_lockless(pgdp
, pgd
, addr
);
7212 p4d
= READ_ONCE(*p4dp
);
7213 if (!p4d_present(p4d
))
7217 return p4d_leaf_size(p4d
);
7219 pudp
= pud_offset_lockless(p4dp
, p4d
, addr
);
7220 pud
= READ_ONCE(*pudp
);
7221 if (!pud_present(pud
))
7225 return pud_leaf_size(pud
);
7227 pmdp
= pmd_offset_lockless(pudp
, pud
, addr
);
7228 pmd
= READ_ONCE(*pmdp
);
7229 if (!pmd_present(pmd
))
7233 return pmd_leaf_size(pmd
);
7235 ptep
= pte_offset_map(&pmd
, addr
);
7236 pte
= ptep_get_lockless(ptep
);
7237 if (pte_present(pte
))
7238 size
= pte_leaf_size(pte
);
7240 #endif /* CONFIG_HAVE_FAST_GUP */
7245 static u64
perf_get_page_size(unsigned long addr
)
7247 struct mm_struct
*mm
;
7248 unsigned long flags
;
7255 * Software page-table walkers must disable IRQs,
7256 * which prevents any tear down of the page tables.
7258 local_irq_save(flags
);
7263 * For kernel threads and the like, use init_mm so that
7264 * we can find kernel memory.
7269 size
= perf_get_pgtable_size(mm
, addr
);
7271 local_irq_restore(flags
);
7276 static struct perf_callchain_entry __empty_callchain
= { .nr
= 0, };
7278 struct perf_callchain_entry
*
7279 perf_callchain(struct perf_event
*event
, struct pt_regs
*regs
)
7281 bool kernel
= !event
->attr
.exclude_callchain_kernel
;
7282 bool user
= !event
->attr
.exclude_callchain_user
;
7283 /* Disallow cross-task user callchains. */
7284 bool crosstask
= event
->ctx
->task
&& event
->ctx
->task
!= current
;
7285 const u32 max_stack
= event
->attr
.sample_max_stack
;
7286 struct perf_callchain_entry
*callchain
;
7288 if (!kernel
&& !user
)
7289 return &__empty_callchain
;
7291 callchain
= get_perf_callchain(regs
, 0, kernel
, user
,
7292 max_stack
, crosstask
, true);
7293 return callchain
?: &__empty_callchain
;
7296 void perf_prepare_sample(struct perf_event_header
*header
,
7297 struct perf_sample_data
*data
,
7298 struct perf_event
*event
,
7299 struct pt_regs
*regs
)
7301 u64 sample_type
= event
->attr
.sample_type
;
7303 header
->type
= PERF_RECORD_SAMPLE
;
7304 header
->size
= sizeof(*header
) + event
->header_size
;
7307 header
->misc
|= perf_misc_flags(regs
);
7309 __perf_event_header__init_id(header
, data
, event
);
7311 if (sample_type
& (PERF_SAMPLE_IP
| PERF_SAMPLE_CODE_PAGE_SIZE
))
7312 data
->ip
= perf_instruction_pointer(regs
);
7314 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7317 if (!(sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
))
7318 data
->callchain
= perf_callchain(event
, regs
);
7320 size
+= data
->callchain
->nr
;
7322 header
->size
+= size
* sizeof(u64
);
7325 if (sample_type
& PERF_SAMPLE_RAW
) {
7326 struct perf_raw_record
*raw
= data
->raw
;
7330 struct perf_raw_frag
*frag
= &raw
->frag
;
7335 if (perf_raw_frag_last(frag
))
7340 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
7341 raw
->size
= size
- sizeof(u32
);
7342 frag
->pad
= raw
->size
- sum
;
7347 header
->size
+= size
;
7350 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7351 int size
= sizeof(u64
); /* nr */
7352 if (data
->br_stack
) {
7353 if (perf_sample_save_hw_index(event
))
7354 size
+= sizeof(u64
);
7356 size
+= data
->br_stack
->nr
7357 * sizeof(struct perf_branch_entry
);
7359 header
->size
+= size
;
7362 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
7363 perf_sample_regs_user(&data
->regs_user
, regs
);
7365 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
7366 /* regs dump ABI info */
7367 int size
= sizeof(u64
);
7369 if (data
->regs_user
.regs
) {
7370 u64 mask
= event
->attr
.sample_regs_user
;
7371 size
+= hweight64(mask
) * sizeof(u64
);
7374 header
->size
+= size
;
7377 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
7379 * Either we need PERF_SAMPLE_STACK_USER bit to be always
7380 * processed as the last one or have additional check added
7381 * in case new sample type is added, because we could eat
7382 * up the rest of the sample size.
7384 u16 stack_size
= event
->attr
.sample_stack_user
;
7385 u16 size
= sizeof(u64
);
7387 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
7388 data
->regs_user
.regs
);
7391 * If there is something to dump, add space for the dump
7392 * itself and for the field that tells the dynamic size,
7393 * which is how many have been actually dumped.
7396 size
+= sizeof(u64
) + stack_size
;
7398 data
->stack_user_size
= stack_size
;
7399 header
->size
+= size
;
7402 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
7403 /* regs dump ABI info */
7404 int size
= sizeof(u64
);
7406 perf_sample_regs_intr(&data
->regs_intr
, regs
);
7408 if (data
->regs_intr
.regs
) {
7409 u64 mask
= event
->attr
.sample_regs_intr
;
7411 size
+= hweight64(mask
) * sizeof(u64
);
7414 header
->size
+= size
;
7417 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
7418 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
7420 #ifdef CONFIG_CGROUP_PERF
7421 if (sample_type
& PERF_SAMPLE_CGROUP
) {
7422 struct cgroup
*cgrp
;
7424 /* protected by RCU */
7425 cgrp
= task_css_check(current
, perf_event_cgrp_id
, 1)->cgroup
;
7426 data
->cgroup
= cgroup_id(cgrp
);
7431 * PERF_DATA_PAGE_SIZE requires PERF_SAMPLE_ADDR. If the user doesn't
7432 * require PERF_SAMPLE_ADDR, kernel implicitly retrieve the data->addr,
7433 * but the value will not dump to the userspace.
7435 if (sample_type
& PERF_SAMPLE_DATA_PAGE_SIZE
)
7436 data
->data_page_size
= perf_get_page_size(data
->addr
);
7438 if (sample_type
& PERF_SAMPLE_CODE_PAGE_SIZE
)
7439 data
->code_page_size
= perf_get_page_size(data
->ip
);
7441 if (sample_type
& PERF_SAMPLE_AUX
) {
7444 header
->size
+= sizeof(u64
); /* size */
7447 * Given the 16bit nature of header::size, an AUX sample can
7448 * easily overflow it, what with all the preceding sample bits.
7449 * Make sure this doesn't happen by using up to U16_MAX bytes
7450 * per sample in total (rounded down to 8 byte boundary).
7452 size
= min_t(size_t, U16_MAX
- header
->size
,
7453 event
->attr
.aux_sample_size
);
7454 size
= rounddown(size
, 8);
7455 size
= perf_prepare_sample_aux(event
, data
, size
);
7457 WARN_ON_ONCE(size
+ header
->size
> U16_MAX
);
7458 header
->size
+= size
;
7461 * If you're adding more sample types here, you likely need to do
7462 * something about the overflowing header::size, like repurpose the
7463 * lowest 3 bits of size, which should be always zero at the moment.
7464 * This raises a more important question, do we really need 512k sized
7465 * samples and why, so good argumentation is in order for whatever you
7468 WARN_ON_ONCE(header
->size
& 7);
7471 static __always_inline
int
7472 __perf_event_output(struct perf_event
*event
,
7473 struct perf_sample_data
*data
,
7474 struct pt_regs
*regs
,
7475 int (*output_begin
)(struct perf_output_handle
*,
7476 struct perf_sample_data
*,
7477 struct perf_event
*,
7480 struct perf_output_handle handle
;
7481 struct perf_event_header header
;
7484 /* protect the callchain buffers */
7487 perf_prepare_sample(&header
, data
, event
, regs
);
7489 err
= output_begin(&handle
, data
, event
, header
.size
);
7493 perf_output_sample(&handle
, &header
, data
, event
);
7495 perf_output_end(&handle
);
7503 perf_event_output_forward(struct perf_event
*event
,
7504 struct perf_sample_data
*data
,
7505 struct pt_regs
*regs
)
7507 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
7511 perf_event_output_backward(struct perf_event
*event
,
7512 struct perf_sample_data
*data
,
7513 struct pt_regs
*regs
)
7515 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
7519 perf_event_output(struct perf_event
*event
,
7520 struct perf_sample_data
*data
,
7521 struct pt_regs
*regs
)
7523 return __perf_event_output(event
, data
, regs
, perf_output_begin
);
7530 struct perf_read_event
{
7531 struct perf_event_header header
;
7538 perf_event_read_event(struct perf_event
*event
,
7539 struct task_struct
*task
)
7541 struct perf_output_handle handle
;
7542 struct perf_sample_data sample
;
7543 struct perf_read_event read_event
= {
7545 .type
= PERF_RECORD_READ
,
7547 .size
= sizeof(read_event
) + event
->read_size
,
7549 .pid
= perf_event_pid(event
, task
),
7550 .tid
= perf_event_tid(event
, task
),
7554 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
7555 ret
= perf_output_begin(&handle
, &sample
, event
, read_event
.header
.size
);
7559 perf_output_put(&handle
, read_event
);
7560 perf_output_read(&handle
, event
);
7561 perf_event__output_id_sample(event
, &handle
, &sample
);
7563 perf_output_end(&handle
);
7566 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
7569 perf_iterate_ctx(struct perf_event_context
*ctx
,
7570 perf_iterate_f output
,
7571 void *data
, bool all
)
7573 struct perf_event
*event
;
7575 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7577 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7579 if (!event_filter_match(event
))
7583 output(event
, data
);
7587 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
7589 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
7590 struct perf_event
*event
;
7592 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
7594 * Skip events that are not fully formed yet; ensure that
7595 * if we observe event->ctx, both event and ctx will be
7596 * complete enough. See perf_install_in_context().
7598 if (!smp_load_acquire(&event
->ctx
))
7601 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7603 if (!event_filter_match(event
))
7605 output(event
, data
);
7610 * Iterate all events that need to receive side-band events.
7612 * For new callers; ensure that account_pmu_sb_event() includes
7613 * your event, otherwise it might not get delivered.
7616 perf_iterate_sb(perf_iterate_f output
, void *data
,
7617 struct perf_event_context
*task_ctx
)
7619 struct perf_event_context
*ctx
;
7626 * If we have task_ctx != NULL we only notify the task context itself.
7627 * The task_ctx is set only for EXIT events before releasing task
7631 perf_iterate_ctx(task_ctx
, output
, data
, false);
7635 perf_iterate_sb_cpu(output
, data
);
7637 for_each_task_context_nr(ctxn
) {
7638 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7640 perf_iterate_ctx(ctx
, output
, data
, false);
7648 * Clear all file-based filters at exec, they'll have to be
7649 * re-instated when/if these objects are mmapped again.
7651 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
7653 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7654 struct perf_addr_filter
*filter
;
7655 unsigned int restart
= 0, count
= 0;
7656 unsigned long flags
;
7658 if (!has_addr_filter(event
))
7661 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7662 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7663 if (filter
->path
.dentry
) {
7664 event
->addr_filter_ranges
[count
].start
= 0;
7665 event
->addr_filter_ranges
[count
].size
= 0;
7673 event
->addr_filters_gen
++;
7674 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7677 perf_event_stop(event
, 1);
7680 void perf_event_exec(void)
7682 struct perf_event_context
*ctx
;
7685 for_each_task_context_nr(ctxn
) {
7686 perf_event_enable_on_exec(ctxn
);
7687 perf_event_remove_on_exec(ctxn
);
7690 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7692 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
,
7699 struct remote_output
{
7700 struct perf_buffer
*rb
;
7704 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
7706 struct perf_event
*parent
= event
->parent
;
7707 struct remote_output
*ro
= data
;
7708 struct perf_buffer
*rb
= ro
->rb
;
7709 struct stop_event_data sd
= {
7713 if (!has_aux(event
))
7720 * In case of inheritance, it will be the parent that links to the
7721 * ring-buffer, but it will be the child that's actually using it.
7723 * We are using event::rb to determine if the event should be stopped,
7724 * however this may race with ring_buffer_attach() (through set_output),
7725 * which will make us skip the event that actually needs to be stopped.
7726 * So ring_buffer_attach() has to stop an aux event before re-assigning
7729 if (rcu_dereference(parent
->rb
) == rb
)
7730 ro
->err
= __perf_event_stop(&sd
);
7733 static int __perf_pmu_output_stop(void *info
)
7735 struct perf_event
*event
= info
;
7736 struct pmu
*pmu
= event
->ctx
->pmu
;
7737 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7738 struct remote_output ro
= {
7743 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
7744 if (cpuctx
->task_ctx
)
7745 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
7752 static void perf_pmu_output_stop(struct perf_event
*event
)
7754 struct perf_event
*iter
;
7759 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
7761 * For per-CPU events, we need to make sure that neither they
7762 * nor their children are running; for cpu==-1 events it's
7763 * sufficient to stop the event itself if it's active, since
7764 * it can't have children.
7768 cpu
= READ_ONCE(iter
->oncpu
);
7773 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
7774 if (err
== -EAGAIN
) {
7783 * task tracking -- fork/exit
7785 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
7788 struct perf_task_event
{
7789 struct task_struct
*task
;
7790 struct perf_event_context
*task_ctx
;
7793 struct perf_event_header header
;
7803 static int perf_event_task_match(struct perf_event
*event
)
7805 return event
->attr
.comm
|| event
->attr
.mmap
||
7806 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
7810 static void perf_event_task_output(struct perf_event
*event
,
7813 struct perf_task_event
*task_event
= data
;
7814 struct perf_output_handle handle
;
7815 struct perf_sample_data sample
;
7816 struct task_struct
*task
= task_event
->task
;
7817 int ret
, size
= task_event
->event_id
.header
.size
;
7819 if (!perf_event_task_match(event
))
7822 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
7824 ret
= perf_output_begin(&handle
, &sample
, event
,
7825 task_event
->event_id
.header
.size
);
7829 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
7830 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
7832 if (task_event
->event_id
.header
.type
== PERF_RECORD_EXIT
) {
7833 task_event
->event_id
.ppid
= perf_event_pid(event
,
7835 task_event
->event_id
.ptid
= perf_event_pid(event
,
7837 } else { /* PERF_RECORD_FORK */
7838 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
7839 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
7842 task_event
->event_id
.time
= perf_event_clock(event
);
7844 perf_output_put(&handle
, task_event
->event_id
);
7846 perf_event__output_id_sample(event
, &handle
, &sample
);
7848 perf_output_end(&handle
);
7850 task_event
->event_id
.header
.size
= size
;
7853 static void perf_event_task(struct task_struct
*task
,
7854 struct perf_event_context
*task_ctx
,
7857 struct perf_task_event task_event
;
7859 if (!atomic_read(&nr_comm_events
) &&
7860 !atomic_read(&nr_mmap_events
) &&
7861 !atomic_read(&nr_task_events
))
7864 task_event
= (struct perf_task_event
){
7866 .task_ctx
= task_ctx
,
7869 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
7871 .size
= sizeof(task_event
.event_id
),
7881 perf_iterate_sb(perf_event_task_output
,
7886 void perf_event_fork(struct task_struct
*task
)
7888 perf_event_task(task
, NULL
, 1);
7889 perf_event_namespaces(task
);
7896 struct perf_comm_event
{
7897 struct task_struct
*task
;
7902 struct perf_event_header header
;
7909 static int perf_event_comm_match(struct perf_event
*event
)
7911 return event
->attr
.comm
;
7914 static void perf_event_comm_output(struct perf_event
*event
,
7917 struct perf_comm_event
*comm_event
= data
;
7918 struct perf_output_handle handle
;
7919 struct perf_sample_data sample
;
7920 int size
= comm_event
->event_id
.header
.size
;
7923 if (!perf_event_comm_match(event
))
7926 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
7927 ret
= perf_output_begin(&handle
, &sample
, event
,
7928 comm_event
->event_id
.header
.size
);
7933 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
7934 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
7936 perf_output_put(&handle
, comm_event
->event_id
);
7937 __output_copy(&handle
, comm_event
->comm
,
7938 comm_event
->comm_size
);
7940 perf_event__output_id_sample(event
, &handle
, &sample
);
7942 perf_output_end(&handle
);
7944 comm_event
->event_id
.header
.size
= size
;
7947 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
7949 char comm
[TASK_COMM_LEN
];
7952 memset(comm
, 0, sizeof(comm
));
7953 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
7954 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
7956 comm_event
->comm
= comm
;
7957 comm_event
->comm_size
= size
;
7959 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
7961 perf_iterate_sb(perf_event_comm_output
,
7966 void perf_event_comm(struct task_struct
*task
, bool exec
)
7968 struct perf_comm_event comm_event
;
7970 if (!atomic_read(&nr_comm_events
))
7973 comm_event
= (struct perf_comm_event
){
7979 .type
= PERF_RECORD_COMM
,
7980 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
7988 perf_event_comm_event(&comm_event
);
7992 * namespaces tracking
7995 struct perf_namespaces_event
{
7996 struct task_struct
*task
;
7999 struct perf_event_header header
;
8004 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
8008 static int perf_event_namespaces_match(struct perf_event
*event
)
8010 return event
->attr
.namespaces
;
8013 static void perf_event_namespaces_output(struct perf_event
*event
,
8016 struct perf_namespaces_event
*namespaces_event
= data
;
8017 struct perf_output_handle handle
;
8018 struct perf_sample_data sample
;
8019 u16 header_size
= namespaces_event
->event_id
.header
.size
;
8022 if (!perf_event_namespaces_match(event
))
8025 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
8027 ret
= perf_output_begin(&handle
, &sample
, event
,
8028 namespaces_event
->event_id
.header
.size
);
8032 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
8033 namespaces_event
->task
);
8034 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
8035 namespaces_event
->task
);
8037 perf_output_put(&handle
, namespaces_event
->event_id
);
8039 perf_event__output_id_sample(event
, &handle
, &sample
);
8041 perf_output_end(&handle
);
8043 namespaces_event
->event_id
.header
.size
= header_size
;
8046 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
8047 struct task_struct
*task
,
8048 const struct proc_ns_operations
*ns_ops
)
8050 struct path ns_path
;
8051 struct inode
*ns_inode
;
8054 error
= ns_get_path(&ns_path
, task
, ns_ops
);
8056 ns_inode
= ns_path
.dentry
->d_inode
;
8057 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
8058 ns_link_info
->ino
= ns_inode
->i_ino
;
8063 void perf_event_namespaces(struct task_struct
*task
)
8065 struct perf_namespaces_event namespaces_event
;
8066 struct perf_ns_link_info
*ns_link_info
;
8068 if (!atomic_read(&nr_namespaces_events
))
8071 namespaces_event
= (struct perf_namespaces_event
){
8075 .type
= PERF_RECORD_NAMESPACES
,
8077 .size
= sizeof(namespaces_event
.event_id
),
8081 .nr_namespaces
= NR_NAMESPACES
,
8082 /* .link_info[NR_NAMESPACES] */
8086 ns_link_info
= namespaces_event
.event_id
.link_info
;
8088 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
8089 task
, &mntns_operations
);
8091 #ifdef CONFIG_USER_NS
8092 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
8093 task
, &userns_operations
);
8095 #ifdef CONFIG_NET_NS
8096 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
8097 task
, &netns_operations
);
8099 #ifdef CONFIG_UTS_NS
8100 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
8101 task
, &utsns_operations
);
8103 #ifdef CONFIG_IPC_NS
8104 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
8105 task
, &ipcns_operations
);
8107 #ifdef CONFIG_PID_NS
8108 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
8109 task
, &pidns_operations
);
8111 #ifdef CONFIG_CGROUPS
8112 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
8113 task
, &cgroupns_operations
);
8116 perf_iterate_sb(perf_event_namespaces_output
,
8124 #ifdef CONFIG_CGROUP_PERF
8126 struct perf_cgroup_event
{
8130 struct perf_event_header header
;
8136 static int perf_event_cgroup_match(struct perf_event
*event
)
8138 return event
->attr
.cgroup
;
8141 static void perf_event_cgroup_output(struct perf_event
*event
, void *data
)
8143 struct perf_cgroup_event
*cgroup_event
= data
;
8144 struct perf_output_handle handle
;
8145 struct perf_sample_data sample
;
8146 u16 header_size
= cgroup_event
->event_id
.header
.size
;
8149 if (!perf_event_cgroup_match(event
))
8152 perf_event_header__init_id(&cgroup_event
->event_id
.header
,
8154 ret
= perf_output_begin(&handle
, &sample
, event
,
8155 cgroup_event
->event_id
.header
.size
);
8159 perf_output_put(&handle
, cgroup_event
->event_id
);
8160 __output_copy(&handle
, cgroup_event
->path
, cgroup_event
->path_size
);
8162 perf_event__output_id_sample(event
, &handle
, &sample
);
8164 perf_output_end(&handle
);
8166 cgroup_event
->event_id
.header
.size
= header_size
;
8169 static void perf_event_cgroup(struct cgroup
*cgrp
)
8171 struct perf_cgroup_event cgroup_event
;
8172 char path_enomem
[16] = "//enomem";
8176 if (!atomic_read(&nr_cgroup_events
))
8179 cgroup_event
= (struct perf_cgroup_event
){
8182 .type
= PERF_RECORD_CGROUP
,
8184 .size
= sizeof(cgroup_event
.event_id
),
8186 .id
= cgroup_id(cgrp
),
8190 pathname
= kmalloc(PATH_MAX
, GFP_KERNEL
);
8191 if (pathname
== NULL
) {
8192 cgroup_event
.path
= path_enomem
;
8194 /* just to be sure to have enough space for alignment */
8195 cgroup_path(cgrp
, pathname
, PATH_MAX
- sizeof(u64
));
8196 cgroup_event
.path
= pathname
;
8200 * Since our buffer works in 8 byte units we need to align our string
8201 * size to a multiple of 8. However, we must guarantee the tail end is
8202 * zero'd out to avoid leaking random bits to userspace.
8204 size
= strlen(cgroup_event
.path
) + 1;
8205 while (!IS_ALIGNED(size
, sizeof(u64
)))
8206 cgroup_event
.path
[size
++] = '\0';
8208 cgroup_event
.event_id
.header
.size
+= size
;
8209 cgroup_event
.path_size
= size
;
8211 perf_iterate_sb(perf_event_cgroup_output
,
8224 struct perf_mmap_event
{
8225 struct vm_area_struct
*vma
;
8227 const char *file_name
;
8233 u8 build_id
[BUILD_ID_SIZE_MAX
];
8237 struct perf_event_header header
;
8247 static int perf_event_mmap_match(struct perf_event
*event
,
8250 struct perf_mmap_event
*mmap_event
= data
;
8251 struct vm_area_struct
*vma
= mmap_event
->vma
;
8252 int executable
= vma
->vm_flags
& VM_EXEC
;
8254 return (!executable
&& event
->attr
.mmap_data
) ||
8255 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
8258 static void perf_event_mmap_output(struct perf_event
*event
,
8261 struct perf_mmap_event
*mmap_event
= data
;
8262 struct perf_output_handle handle
;
8263 struct perf_sample_data sample
;
8264 int size
= mmap_event
->event_id
.header
.size
;
8265 u32 type
= mmap_event
->event_id
.header
.type
;
8269 if (!perf_event_mmap_match(event
, data
))
8272 if (event
->attr
.mmap2
) {
8273 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
8274 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
8275 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
8276 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
8277 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
8278 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
8279 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
8282 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
8283 ret
= perf_output_begin(&handle
, &sample
, event
,
8284 mmap_event
->event_id
.header
.size
);
8288 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
8289 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
8291 use_build_id
= event
->attr
.build_id
&& mmap_event
->build_id_size
;
8293 if (event
->attr
.mmap2
&& use_build_id
)
8294 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_BUILD_ID
;
8296 perf_output_put(&handle
, mmap_event
->event_id
);
8298 if (event
->attr
.mmap2
) {
8300 u8 size
[4] = { (u8
) mmap_event
->build_id_size
, 0, 0, 0 };
8302 __output_copy(&handle
, size
, 4);
8303 __output_copy(&handle
, mmap_event
->build_id
, BUILD_ID_SIZE_MAX
);
8305 perf_output_put(&handle
, mmap_event
->maj
);
8306 perf_output_put(&handle
, mmap_event
->min
);
8307 perf_output_put(&handle
, mmap_event
->ino
);
8308 perf_output_put(&handle
, mmap_event
->ino_generation
);
8310 perf_output_put(&handle
, mmap_event
->prot
);
8311 perf_output_put(&handle
, mmap_event
->flags
);
8314 __output_copy(&handle
, mmap_event
->file_name
,
8315 mmap_event
->file_size
);
8317 perf_event__output_id_sample(event
, &handle
, &sample
);
8319 perf_output_end(&handle
);
8321 mmap_event
->event_id
.header
.size
= size
;
8322 mmap_event
->event_id
.header
.type
= type
;
8325 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
8327 struct vm_area_struct
*vma
= mmap_event
->vma
;
8328 struct file
*file
= vma
->vm_file
;
8329 int maj
= 0, min
= 0;
8330 u64 ino
= 0, gen
= 0;
8331 u32 prot
= 0, flags
= 0;
8337 if (vma
->vm_flags
& VM_READ
)
8339 if (vma
->vm_flags
& VM_WRITE
)
8341 if (vma
->vm_flags
& VM_EXEC
)
8344 if (vma
->vm_flags
& VM_MAYSHARE
)
8347 flags
= MAP_PRIVATE
;
8349 if (vma
->vm_flags
& VM_LOCKED
)
8350 flags
|= MAP_LOCKED
;
8351 if (is_vm_hugetlb_page(vma
))
8352 flags
|= MAP_HUGETLB
;
8355 struct inode
*inode
;
8358 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
8364 * d_path() works from the end of the rb backwards, so we
8365 * need to add enough zero bytes after the string to handle
8366 * the 64bit alignment we do later.
8368 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
8373 inode
= file_inode(vma
->vm_file
);
8374 dev
= inode
->i_sb
->s_dev
;
8376 gen
= inode
->i_generation
;
8382 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
8383 name
= (char *) vma
->vm_ops
->name(vma
);
8388 name
= (char *)arch_vma_name(vma
);
8392 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
8393 vma
->vm_end
>= vma
->vm_mm
->brk
) {
8397 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
8398 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
8408 strlcpy(tmp
, name
, sizeof(tmp
));
8412 * Since our buffer works in 8 byte units we need to align our string
8413 * size to a multiple of 8. However, we must guarantee the tail end is
8414 * zero'd out to avoid leaking random bits to userspace.
8416 size
= strlen(name
)+1;
8417 while (!IS_ALIGNED(size
, sizeof(u64
)))
8418 name
[size
++] = '\0';
8420 mmap_event
->file_name
= name
;
8421 mmap_event
->file_size
= size
;
8422 mmap_event
->maj
= maj
;
8423 mmap_event
->min
= min
;
8424 mmap_event
->ino
= ino
;
8425 mmap_event
->ino_generation
= gen
;
8426 mmap_event
->prot
= prot
;
8427 mmap_event
->flags
= flags
;
8429 if (!(vma
->vm_flags
& VM_EXEC
))
8430 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
8432 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
8434 if (atomic_read(&nr_build_id_events
))
8435 build_id_parse(vma
, mmap_event
->build_id
, &mmap_event
->build_id_size
);
8437 perf_iterate_sb(perf_event_mmap_output
,
8445 * Check whether inode and address range match filter criteria.
8447 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
8448 struct file
*file
, unsigned long offset
,
8451 /* d_inode(NULL) won't be equal to any mapped user-space file */
8452 if (!filter
->path
.dentry
)
8455 if (d_inode(filter
->path
.dentry
) != file_inode(file
))
8458 if (filter
->offset
> offset
+ size
)
8461 if (filter
->offset
+ filter
->size
< offset
)
8467 static bool perf_addr_filter_vma_adjust(struct perf_addr_filter
*filter
,
8468 struct vm_area_struct
*vma
,
8469 struct perf_addr_filter_range
*fr
)
8471 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8472 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8473 struct file
*file
= vma
->vm_file
;
8475 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8478 if (filter
->offset
< off
) {
8479 fr
->start
= vma
->vm_start
;
8480 fr
->size
= min(vma_size
, filter
->size
- (off
- filter
->offset
));
8482 fr
->start
= vma
->vm_start
+ filter
->offset
- off
;
8483 fr
->size
= min(vma
->vm_end
- fr
->start
, filter
->size
);
8489 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
8491 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8492 struct vm_area_struct
*vma
= data
;
8493 struct perf_addr_filter
*filter
;
8494 unsigned int restart
= 0, count
= 0;
8495 unsigned long flags
;
8497 if (!has_addr_filter(event
))
8503 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8504 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8505 if (perf_addr_filter_vma_adjust(filter
, vma
,
8506 &event
->addr_filter_ranges
[count
]))
8513 event
->addr_filters_gen
++;
8514 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8517 perf_event_stop(event
, 1);
8521 * Adjust all task's events' filters to the new vma
8523 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
8525 struct perf_event_context
*ctx
;
8529 * Data tracing isn't supported yet and as such there is no need
8530 * to keep track of anything that isn't related to executable code:
8532 if (!(vma
->vm_flags
& VM_EXEC
))
8536 for_each_task_context_nr(ctxn
) {
8537 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
8541 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
8546 void perf_event_mmap(struct vm_area_struct
*vma
)
8548 struct perf_mmap_event mmap_event
;
8550 if (!atomic_read(&nr_mmap_events
))
8553 mmap_event
= (struct perf_mmap_event
){
8559 .type
= PERF_RECORD_MMAP
,
8560 .misc
= PERF_RECORD_MISC_USER
,
8565 .start
= vma
->vm_start
,
8566 .len
= vma
->vm_end
- vma
->vm_start
,
8567 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
8569 /* .maj (attr_mmap2 only) */
8570 /* .min (attr_mmap2 only) */
8571 /* .ino (attr_mmap2 only) */
8572 /* .ino_generation (attr_mmap2 only) */
8573 /* .prot (attr_mmap2 only) */
8574 /* .flags (attr_mmap2 only) */
8577 perf_addr_filters_adjust(vma
);
8578 perf_event_mmap_event(&mmap_event
);
8581 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
8582 unsigned long size
, u64 flags
)
8584 struct perf_output_handle handle
;
8585 struct perf_sample_data sample
;
8586 struct perf_aux_event
{
8587 struct perf_event_header header
;
8593 .type
= PERF_RECORD_AUX
,
8595 .size
= sizeof(rec
),
8603 perf_event_header__init_id(&rec
.header
, &sample
, event
);
8604 ret
= perf_output_begin(&handle
, &sample
, event
, rec
.header
.size
);
8609 perf_output_put(&handle
, rec
);
8610 perf_event__output_id_sample(event
, &handle
, &sample
);
8612 perf_output_end(&handle
);
8616 * Lost/dropped samples logging
8618 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
8620 struct perf_output_handle handle
;
8621 struct perf_sample_data sample
;
8625 struct perf_event_header header
;
8627 } lost_samples_event
= {
8629 .type
= PERF_RECORD_LOST_SAMPLES
,
8631 .size
= sizeof(lost_samples_event
),
8636 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
8638 ret
= perf_output_begin(&handle
, &sample
, event
,
8639 lost_samples_event
.header
.size
);
8643 perf_output_put(&handle
, lost_samples_event
);
8644 perf_event__output_id_sample(event
, &handle
, &sample
);
8645 perf_output_end(&handle
);
8649 * context_switch tracking
8652 struct perf_switch_event
{
8653 struct task_struct
*task
;
8654 struct task_struct
*next_prev
;
8657 struct perf_event_header header
;
8663 static int perf_event_switch_match(struct perf_event
*event
)
8665 return event
->attr
.context_switch
;
8668 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
8670 struct perf_switch_event
*se
= data
;
8671 struct perf_output_handle handle
;
8672 struct perf_sample_data sample
;
8675 if (!perf_event_switch_match(event
))
8678 /* Only CPU-wide events are allowed to see next/prev pid/tid */
8679 if (event
->ctx
->task
) {
8680 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
8681 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
8683 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
8684 se
->event_id
.header
.size
= sizeof(se
->event_id
);
8685 se
->event_id
.next_prev_pid
=
8686 perf_event_pid(event
, se
->next_prev
);
8687 se
->event_id
.next_prev_tid
=
8688 perf_event_tid(event
, se
->next_prev
);
8691 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
8693 ret
= perf_output_begin(&handle
, &sample
, event
, se
->event_id
.header
.size
);
8697 if (event
->ctx
->task
)
8698 perf_output_put(&handle
, se
->event_id
.header
);
8700 perf_output_put(&handle
, se
->event_id
);
8702 perf_event__output_id_sample(event
, &handle
, &sample
);
8704 perf_output_end(&handle
);
8707 static void perf_event_switch(struct task_struct
*task
,
8708 struct task_struct
*next_prev
, bool sched_in
)
8710 struct perf_switch_event switch_event
;
8712 /* N.B. caller checks nr_switch_events != 0 */
8714 switch_event
= (struct perf_switch_event
){
8716 .next_prev
= next_prev
,
8720 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
8723 /* .next_prev_pid */
8724 /* .next_prev_tid */
8728 if (!sched_in
&& task
->on_rq
) {
8729 switch_event
.event_id
.header
.misc
|=
8730 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT
;
8733 perf_iterate_sb(perf_event_switch_output
, &switch_event
, NULL
);
8737 * IRQ throttle logging
8740 static void perf_log_throttle(struct perf_event
*event
, int enable
)
8742 struct perf_output_handle handle
;
8743 struct perf_sample_data sample
;
8747 struct perf_event_header header
;
8751 } throttle_event
= {
8753 .type
= PERF_RECORD_THROTTLE
,
8755 .size
= sizeof(throttle_event
),
8757 .time
= perf_event_clock(event
),
8758 .id
= primary_event_id(event
),
8759 .stream_id
= event
->id
,
8763 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
8765 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
8767 ret
= perf_output_begin(&handle
, &sample
, event
,
8768 throttle_event
.header
.size
);
8772 perf_output_put(&handle
, throttle_event
);
8773 perf_event__output_id_sample(event
, &handle
, &sample
);
8774 perf_output_end(&handle
);
8778 * ksymbol register/unregister tracking
8781 struct perf_ksymbol_event
{
8785 struct perf_event_header header
;
8793 static int perf_event_ksymbol_match(struct perf_event
*event
)
8795 return event
->attr
.ksymbol
;
8798 static void perf_event_ksymbol_output(struct perf_event
*event
, void *data
)
8800 struct perf_ksymbol_event
*ksymbol_event
= data
;
8801 struct perf_output_handle handle
;
8802 struct perf_sample_data sample
;
8805 if (!perf_event_ksymbol_match(event
))
8808 perf_event_header__init_id(&ksymbol_event
->event_id
.header
,
8810 ret
= perf_output_begin(&handle
, &sample
, event
,
8811 ksymbol_event
->event_id
.header
.size
);
8815 perf_output_put(&handle
, ksymbol_event
->event_id
);
8816 __output_copy(&handle
, ksymbol_event
->name
, ksymbol_event
->name_len
);
8817 perf_event__output_id_sample(event
, &handle
, &sample
);
8819 perf_output_end(&handle
);
8822 void perf_event_ksymbol(u16 ksym_type
, u64 addr
, u32 len
, bool unregister
,
8825 struct perf_ksymbol_event ksymbol_event
;
8826 char name
[KSYM_NAME_LEN
];
8830 if (!atomic_read(&nr_ksymbol_events
))
8833 if (ksym_type
>= PERF_RECORD_KSYMBOL_TYPE_MAX
||
8834 ksym_type
== PERF_RECORD_KSYMBOL_TYPE_UNKNOWN
)
8837 strlcpy(name
, sym
, KSYM_NAME_LEN
);
8838 name_len
= strlen(name
) + 1;
8839 while (!IS_ALIGNED(name_len
, sizeof(u64
)))
8840 name
[name_len
++] = '\0';
8841 BUILD_BUG_ON(KSYM_NAME_LEN
% sizeof(u64
));
8844 flags
|= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER
;
8846 ksymbol_event
= (struct perf_ksymbol_event
){
8848 .name_len
= name_len
,
8851 .type
= PERF_RECORD_KSYMBOL
,
8852 .size
= sizeof(ksymbol_event
.event_id
) +
8857 .ksym_type
= ksym_type
,
8862 perf_iterate_sb(perf_event_ksymbol_output
, &ksymbol_event
, NULL
);
8865 WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__
, ksym_type
);
8869 * bpf program load/unload tracking
8872 struct perf_bpf_event
{
8873 struct bpf_prog
*prog
;
8875 struct perf_event_header header
;
8879 u8 tag
[BPF_TAG_SIZE
];
8883 static int perf_event_bpf_match(struct perf_event
*event
)
8885 return event
->attr
.bpf_event
;
8888 static void perf_event_bpf_output(struct perf_event
*event
, void *data
)
8890 struct perf_bpf_event
*bpf_event
= data
;
8891 struct perf_output_handle handle
;
8892 struct perf_sample_data sample
;
8895 if (!perf_event_bpf_match(event
))
8898 perf_event_header__init_id(&bpf_event
->event_id
.header
,
8900 ret
= perf_output_begin(&handle
, data
, event
,
8901 bpf_event
->event_id
.header
.size
);
8905 perf_output_put(&handle
, bpf_event
->event_id
);
8906 perf_event__output_id_sample(event
, &handle
, &sample
);
8908 perf_output_end(&handle
);
8911 static void perf_event_bpf_emit_ksymbols(struct bpf_prog
*prog
,
8912 enum perf_bpf_event_type type
)
8914 bool unregister
= type
== PERF_BPF_EVENT_PROG_UNLOAD
;
8917 if (prog
->aux
->func_cnt
== 0) {
8918 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF
,
8919 (u64
)(unsigned long)prog
->bpf_func
,
8920 prog
->jited_len
, unregister
,
8921 prog
->aux
->ksym
.name
);
8923 for (i
= 0; i
< prog
->aux
->func_cnt
; i
++) {
8924 struct bpf_prog
*subprog
= prog
->aux
->func
[i
];
8927 PERF_RECORD_KSYMBOL_TYPE_BPF
,
8928 (u64
)(unsigned long)subprog
->bpf_func
,
8929 subprog
->jited_len
, unregister
,
8930 prog
->aux
->ksym
.name
);
8935 void perf_event_bpf_event(struct bpf_prog
*prog
,
8936 enum perf_bpf_event_type type
,
8939 struct perf_bpf_event bpf_event
;
8941 if (type
<= PERF_BPF_EVENT_UNKNOWN
||
8942 type
>= PERF_BPF_EVENT_MAX
)
8946 case PERF_BPF_EVENT_PROG_LOAD
:
8947 case PERF_BPF_EVENT_PROG_UNLOAD
:
8948 if (atomic_read(&nr_ksymbol_events
))
8949 perf_event_bpf_emit_ksymbols(prog
, type
);
8955 if (!atomic_read(&nr_bpf_events
))
8958 bpf_event
= (struct perf_bpf_event
){
8962 .type
= PERF_RECORD_BPF_EVENT
,
8963 .size
= sizeof(bpf_event
.event_id
),
8967 .id
= prog
->aux
->id
,
8971 BUILD_BUG_ON(BPF_TAG_SIZE
% sizeof(u64
));
8973 memcpy(bpf_event
.event_id
.tag
, prog
->tag
, BPF_TAG_SIZE
);
8974 perf_iterate_sb(perf_event_bpf_output
, &bpf_event
, NULL
);
8977 struct perf_text_poke_event
{
8978 const void *old_bytes
;
8979 const void *new_bytes
;
8985 struct perf_event_header header
;
8991 static int perf_event_text_poke_match(struct perf_event
*event
)
8993 return event
->attr
.text_poke
;
8996 static void perf_event_text_poke_output(struct perf_event
*event
, void *data
)
8998 struct perf_text_poke_event
*text_poke_event
= data
;
8999 struct perf_output_handle handle
;
9000 struct perf_sample_data sample
;
9004 if (!perf_event_text_poke_match(event
))
9007 perf_event_header__init_id(&text_poke_event
->event_id
.header
, &sample
, event
);
9009 ret
= perf_output_begin(&handle
, &sample
, event
,
9010 text_poke_event
->event_id
.header
.size
);
9014 perf_output_put(&handle
, text_poke_event
->event_id
);
9015 perf_output_put(&handle
, text_poke_event
->old_len
);
9016 perf_output_put(&handle
, text_poke_event
->new_len
);
9018 __output_copy(&handle
, text_poke_event
->old_bytes
, text_poke_event
->old_len
);
9019 __output_copy(&handle
, text_poke_event
->new_bytes
, text_poke_event
->new_len
);
9021 if (text_poke_event
->pad
)
9022 __output_copy(&handle
, &padding
, text_poke_event
->pad
);
9024 perf_event__output_id_sample(event
, &handle
, &sample
);
9026 perf_output_end(&handle
);
9029 void perf_event_text_poke(const void *addr
, const void *old_bytes
,
9030 size_t old_len
, const void *new_bytes
, size_t new_len
)
9032 struct perf_text_poke_event text_poke_event
;
9035 if (!atomic_read(&nr_text_poke_events
))
9038 tot
= sizeof(text_poke_event
.old_len
) + old_len
;
9039 tot
+= sizeof(text_poke_event
.new_len
) + new_len
;
9040 pad
= ALIGN(tot
, sizeof(u64
)) - tot
;
9042 text_poke_event
= (struct perf_text_poke_event
){
9043 .old_bytes
= old_bytes
,
9044 .new_bytes
= new_bytes
,
9050 .type
= PERF_RECORD_TEXT_POKE
,
9051 .misc
= PERF_RECORD_MISC_KERNEL
,
9052 .size
= sizeof(text_poke_event
.event_id
) + tot
+ pad
,
9054 .addr
= (unsigned long)addr
,
9058 perf_iterate_sb(perf_event_text_poke_output
, &text_poke_event
, NULL
);
9061 void perf_event_itrace_started(struct perf_event
*event
)
9063 event
->attach_state
|= PERF_ATTACH_ITRACE
;
9066 static void perf_log_itrace_start(struct perf_event
*event
)
9068 struct perf_output_handle handle
;
9069 struct perf_sample_data sample
;
9070 struct perf_aux_event
{
9071 struct perf_event_header header
;
9078 event
= event
->parent
;
9080 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
9081 event
->attach_state
& PERF_ATTACH_ITRACE
)
9084 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
9085 rec
.header
.misc
= 0;
9086 rec
.header
.size
= sizeof(rec
);
9087 rec
.pid
= perf_event_pid(event
, current
);
9088 rec
.tid
= perf_event_tid(event
, current
);
9090 perf_event_header__init_id(&rec
.header
, &sample
, event
);
9091 ret
= perf_output_begin(&handle
, &sample
, event
, rec
.header
.size
);
9096 perf_output_put(&handle
, rec
);
9097 perf_event__output_id_sample(event
, &handle
, &sample
);
9099 perf_output_end(&handle
);
9103 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
9105 struct hw_perf_event
*hwc
= &event
->hw
;
9109 seq
= __this_cpu_read(perf_throttled_seq
);
9110 if (seq
!= hwc
->interrupts_seq
) {
9111 hwc
->interrupts_seq
= seq
;
9112 hwc
->interrupts
= 1;
9115 if (unlikely(throttle
9116 && hwc
->interrupts
>= max_samples_per_tick
)) {
9117 __this_cpu_inc(perf_throttled_count
);
9118 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
9119 hwc
->interrupts
= MAX_INTERRUPTS
;
9120 perf_log_throttle(event
, 0);
9125 if (event
->attr
.freq
) {
9126 u64 now
= perf_clock();
9127 s64 delta
= now
- hwc
->freq_time_stamp
;
9129 hwc
->freq_time_stamp
= now
;
9131 if (delta
> 0 && delta
< 2*TICK_NSEC
)
9132 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
9138 int perf_event_account_interrupt(struct perf_event
*event
)
9140 return __perf_event_account_interrupt(event
, 1);
9144 * Generic event overflow handling, sampling.
9147 static int __perf_event_overflow(struct perf_event
*event
,
9148 int throttle
, struct perf_sample_data
*data
,
9149 struct pt_regs
*regs
)
9151 int events
= atomic_read(&event
->event_limit
);
9155 * Non-sampling counters might still use the PMI to fold short
9156 * hardware counters, ignore those.
9158 if (unlikely(!is_sampling_event(event
)))
9161 ret
= __perf_event_account_interrupt(event
, throttle
);
9164 * XXX event_limit might not quite work as expected on inherited
9168 event
->pending_kill
= POLL_IN
;
9169 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
9171 event
->pending_kill
= POLL_HUP
;
9172 event
->pending_addr
= data
->addr
;
9174 perf_event_disable_inatomic(event
);
9177 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
9179 if (*perf_event_fasync(event
) && event
->pending_kill
) {
9180 event
->pending_wakeup
= 1;
9181 irq_work_queue(&event
->pending
);
9187 int perf_event_overflow(struct perf_event
*event
,
9188 struct perf_sample_data
*data
,
9189 struct pt_regs
*regs
)
9191 return __perf_event_overflow(event
, 1, data
, regs
);
9195 * Generic software event infrastructure
9198 struct swevent_htable
{
9199 struct swevent_hlist
*swevent_hlist
;
9200 struct mutex hlist_mutex
;
9203 /* Recursion avoidance in each contexts */
9204 int recursion
[PERF_NR_CONTEXTS
];
9207 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
9210 * We directly increment event->count and keep a second value in
9211 * event->hw.period_left to count intervals. This period event
9212 * is kept in the range [-sample_period, 0] so that we can use the
9216 u64
perf_swevent_set_period(struct perf_event
*event
)
9218 struct hw_perf_event
*hwc
= &event
->hw
;
9219 u64 period
= hwc
->last_period
;
9223 hwc
->last_period
= hwc
->sample_period
;
9226 old
= val
= local64_read(&hwc
->period_left
);
9230 nr
= div64_u64(period
+ val
, period
);
9231 offset
= nr
* period
;
9233 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
9239 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
9240 struct perf_sample_data
*data
,
9241 struct pt_regs
*regs
)
9243 struct hw_perf_event
*hwc
= &event
->hw
;
9247 overflow
= perf_swevent_set_period(event
);
9249 if (hwc
->interrupts
== MAX_INTERRUPTS
)
9252 for (; overflow
; overflow
--) {
9253 if (__perf_event_overflow(event
, throttle
,
9256 * We inhibit the overflow from happening when
9257 * hwc->interrupts == MAX_INTERRUPTS.
9265 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
9266 struct perf_sample_data
*data
,
9267 struct pt_regs
*regs
)
9269 struct hw_perf_event
*hwc
= &event
->hw
;
9271 local64_add(nr
, &event
->count
);
9276 if (!is_sampling_event(event
))
9279 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
9281 return perf_swevent_overflow(event
, 1, data
, regs
);
9283 data
->period
= event
->hw
.last_period
;
9285 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
9286 return perf_swevent_overflow(event
, 1, data
, regs
);
9288 if (local64_add_negative(nr
, &hwc
->period_left
))
9291 perf_swevent_overflow(event
, 0, data
, regs
);
9294 static int perf_exclude_event(struct perf_event
*event
,
9295 struct pt_regs
*regs
)
9297 if (event
->hw
.state
& PERF_HES_STOPPED
)
9301 if (event
->attr
.exclude_user
&& user_mode(regs
))
9304 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
9311 static int perf_swevent_match(struct perf_event
*event
,
9312 enum perf_type_id type
,
9314 struct perf_sample_data
*data
,
9315 struct pt_regs
*regs
)
9317 if (event
->attr
.type
!= type
)
9320 if (event
->attr
.config
!= event_id
)
9323 if (perf_exclude_event(event
, regs
))
9329 static inline u64
swevent_hash(u64 type
, u32 event_id
)
9331 u64 val
= event_id
| (type
<< 32);
9333 return hash_64(val
, SWEVENT_HLIST_BITS
);
9336 static inline struct hlist_head
*
9337 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
9339 u64 hash
= swevent_hash(type
, event_id
);
9341 return &hlist
->heads
[hash
];
9344 /* For the read side: events when they trigger */
9345 static inline struct hlist_head
*
9346 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
9348 struct swevent_hlist
*hlist
;
9350 hlist
= rcu_dereference(swhash
->swevent_hlist
);
9354 return __find_swevent_head(hlist
, type
, event_id
);
9357 /* For the event head insertion and removal in the hlist */
9358 static inline struct hlist_head
*
9359 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
9361 struct swevent_hlist
*hlist
;
9362 u32 event_id
= event
->attr
.config
;
9363 u64 type
= event
->attr
.type
;
9366 * Event scheduling is always serialized against hlist allocation
9367 * and release. Which makes the protected version suitable here.
9368 * The context lock guarantees that.
9370 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
9371 lockdep_is_held(&event
->ctx
->lock
));
9375 return __find_swevent_head(hlist
, type
, event_id
);
9378 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
9380 struct perf_sample_data
*data
,
9381 struct pt_regs
*regs
)
9383 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
9384 struct perf_event
*event
;
9385 struct hlist_head
*head
;
9388 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
9392 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
9393 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
9394 perf_swevent_event(event
, nr
, data
, regs
);
9400 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
9402 int perf_swevent_get_recursion_context(void)
9404 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
9406 return get_recursion_context(swhash
->recursion
);
9408 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
9410 void perf_swevent_put_recursion_context(int rctx
)
9412 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
9414 put_recursion_context(swhash
->recursion
, rctx
);
9417 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
9419 struct perf_sample_data data
;
9421 if (WARN_ON_ONCE(!regs
))
9424 perf_sample_data_init(&data
, addr
, 0);
9425 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
9428 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
9432 preempt_disable_notrace();
9433 rctx
= perf_swevent_get_recursion_context();
9434 if (unlikely(rctx
< 0))
9437 ___perf_sw_event(event_id
, nr
, regs
, addr
);
9439 perf_swevent_put_recursion_context(rctx
);
9441 preempt_enable_notrace();
9444 static void perf_swevent_read(struct perf_event
*event
)
9448 static int perf_swevent_add(struct perf_event
*event
, int flags
)
9450 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
9451 struct hw_perf_event
*hwc
= &event
->hw
;
9452 struct hlist_head
*head
;
9454 if (is_sampling_event(event
)) {
9455 hwc
->last_period
= hwc
->sample_period
;
9456 perf_swevent_set_period(event
);
9459 hwc
->state
= !(flags
& PERF_EF_START
);
9461 head
= find_swevent_head(swhash
, event
);
9462 if (WARN_ON_ONCE(!head
))
9465 hlist_add_head_rcu(&event
->hlist_entry
, head
);
9466 perf_event_update_userpage(event
);
9471 static void perf_swevent_del(struct perf_event
*event
, int flags
)
9473 hlist_del_rcu(&event
->hlist_entry
);
9476 static void perf_swevent_start(struct perf_event
*event
, int flags
)
9478 event
->hw
.state
= 0;
9481 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
9483 event
->hw
.state
= PERF_HES_STOPPED
;
9486 /* Deref the hlist from the update side */
9487 static inline struct swevent_hlist
*
9488 swevent_hlist_deref(struct swevent_htable
*swhash
)
9490 return rcu_dereference_protected(swhash
->swevent_hlist
,
9491 lockdep_is_held(&swhash
->hlist_mutex
));
9494 static void swevent_hlist_release(struct swevent_htable
*swhash
)
9496 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
9501 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
9502 kfree_rcu(hlist
, rcu_head
);
9505 static void swevent_hlist_put_cpu(int cpu
)
9507 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9509 mutex_lock(&swhash
->hlist_mutex
);
9511 if (!--swhash
->hlist_refcount
)
9512 swevent_hlist_release(swhash
);
9514 mutex_unlock(&swhash
->hlist_mutex
);
9517 static void swevent_hlist_put(void)
9521 for_each_possible_cpu(cpu
)
9522 swevent_hlist_put_cpu(cpu
);
9525 static int swevent_hlist_get_cpu(int cpu
)
9527 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9530 mutex_lock(&swhash
->hlist_mutex
);
9531 if (!swevent_hlist_deref(swhash
) &&
9532 cpumask_test_cpu(cpu
, perf_online_mask
)) {
9533 struct swevent_hlist
*hlist
;
9535 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
9540 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9542 swhash
->hlist_refcount
++;
9544 mutex_unlock(&swhash
->hlist_mutex
);
9549 static int swevent_hlist_get(void)
9551 int err
, cpu
, failed_cpu
;
9553 mutex_lock(&pmus_lock
);
9554 for_each_possible_cpu(cpu
) {
9555 err
= swevent_hlist_get_cpu(cpu
);
9561 mutex_unlock(&pmus_lock
);
9564 for_each_possible_cpu(cpu
) {
9565 if (cpu
== failed_cpu
)
9567 swevent_hlist_put_cpu(cpu
);
9569 mutex_unlock(&pmus_lock
);
9573 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
9575 static void sw_perf_event_destroy(struct perf_event
*event
)
9577 u64 event_id
= event
->attr
.config
;
9579 WARN_ON(event
->parent
);
9581 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
9582 swevent_hlist_put();
9585 static int perf_swevent_init(struct perf_event
*event
)
9587 u64 event_id
= event
->attr
.config
;
9589 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9593 * no branch sampling for software events
9595 if (has_branch_stack(event
))
9599 case PERF_COUNT_SW_CPU_CLOCK
:
9600 case PERF_COUNT_SW_TASK_CLOCK
:
9607 if (event_id
>= PERF_COUNT_SW_MAX
)
9610 if (!event
->parent
) {
9613 err
= swevent_hlist_get();
9617 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
9618 event
->destroy
= sw_perf_event_destroy
;
9624 static struct pmu perf_swevent
= {
9625 .task_ctx_nr
= perf_sw_context
,
9627 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9629 .event_init
= perf_swevent_init
,
9630 .add
= perf_swevent_add
,
9631 .del
= perf_swevent_del
,
9632 .start
= perf_swevent_start
,
9633 .stop
= perf_swevent_stop
,
9634 .read
= perf_swevent_read
,
9637 #ifdef CONFIG_EVENT_TRACING
9639 static int perf_tp_filter_match(struct perf_event
*event
,
9640 struct perf_sample_data
*data
)
9642 void *record
= data
->raw
->frag
.data
;
9644 /* only top level events have filters set */
9646 event
= event
->parent
;
9648 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
9653 static int perf_tp_event_match(struct perf_event
*event
,
9654 struct perf_sample_data
*data
,
9655 struct pt_regs
*regs
)
9657 if (event
->hw
.state
& PERF_HES_STOPPED
)
9660 * If exclude_kernel, only trace user-space tracepoints (uprobes)
9662 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
9665 if (!perf_tp_filter_match(event
, data
))
9671 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
9672 struct trace_event_call
*call
, u64 count
,
9673 struct pt_regs
*regs
, struct hlist_head
*head
,
9674 struct task_struct
*task
)
9676 if (bpf_prog_array_valid(call
)) {
9677 *(struct pt_regs
**)raw_data
= regs
;
9678 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
9679 perf_swevent_put_recursion_context(rctx
);
9683 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
9686 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
9688 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
9689 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
9690 struct task_struct
*task
)
9692 struct perf_sample_data data
;
9693 struct perf_event
*event
;
9695 struct perf_raw_record raw
= {
9702 perf_sample_data_init(&data
, 0, 0);
9705 perf_trace_buf_update(record
, event_type
);
9707 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
9708 if (perf_tp_event_match(event
, &data
, regs
))
9709 perf_swevent_event(event
, count
, &data
, regs
);
9713 * If we got specified a target task, also iterate its context and
9714 * deliver this event there too.
9716 if (task
&& task
!= current
) {
9717 struct perf_event_context
*ctx
;
9718 struct trace_entry
*entry
= record
;
9721 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
9725 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
9726 if (event
->cpu
!= smp_processor_id())
9728 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
9730 if (event
->attr
.config
!= entry
->type
)
9732 if (perf_tp_event_match(event
, &data
, regs
))
9733 perf_swevent_event(event
, count
, &data
, regs
);
9739 perf_swevent_put_recursion_context(rctx
);
9741 EXPORT_SYMBOL_GPL(perf_tp_event
);
9743 static void tp_perf_event_destroy(struct perf_event
*event
)
9745 perf_trace_destroy(event
);
9748 static int perf_tp_event_init(struct perf_event
*event
)
9752 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
9756 * no branch sampling for tracepoint events
9758 if (has_branch_stack(event
))
9761 err
= perf_trace_init(event
);
9765 event
->destroy
= tp_perf_event_destroy
;
9770 static struct pmu perf_tracepoint
= {
9771 .task_ctx_nr
= perf_sw_context
,
9773 .event_init
= perf_tp_event_init
,
9774 .add
= perf_trace_add
,
9775 .del
= perf_trace_del
,
9776 .start
= perf_swevent_start
,
9777 .stop
= perf_swevent_stop
,
9778 .read
= perf_swevent_read
,
9781 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
9783 * Flags in config, used by dynamic PMU kprobe and uprobe
9784 * The flags should match following PMU_FORMAT_ATTR().
9786 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
9787 * if not set, create kprobe/uprobe
9789 * The following values specify a reference counter (or semaphore in the
9790 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
9791 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
9793 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
9794 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
9796 enum perf_probe_config
{
9797 PERF_PROBE_CONFIG_IS_RETPROBE
= 1U << 0, /* [k,u]retprobe */
9798 PERF_UPROBE_REF_CTR_OFFSET_BITS
= 32,
9799 PERF_UPROBE_REF_CTR_OFFSET_SHIFT
= 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS
,
9802 PMU_FORMAT_ATTR(retprobe
, "config:0");
9805 #ifdef CONFIG_KPROBE_EVENTS
9806 static struct attribute
*kprobe_attrs
[] = {
9807 &format_attr_retprobe
.attr
,
9811 static struct attribute_group kprobe_format_group
= {
9813 .attrs
= kprobe_attrs
,
9816 static const struct attribute_group
*kprobe_attr_groups
[] = {
9817 &kprobe_format_group
,
9821 static int perf_kprobe_event_init(struct perf_event
*event
);
9822 static struct pmu perf_kprobe
= {
9823 .task_ctx_nr
= perf_sw_context
,
9824 .event_init
= perf_kprobe_event_init
,
9825 .add
= perf_trace_add
,
9826 .del
= perf_trace_del
,
9827 .start
= perf_swevent_start
,
9828 .stop
= perf_swevent_stop
,
9829 .read
= perf_swevent_read
,
9830 .attr_groups
= kprobe_attr_groups
,
9833 static int perf_kprobe_event_init(struct perf_event
*event
)
9838 if (event
->attr
.type
!= perf_kprobe
.type
)
9841 if (!perfmon_capable())
9845 * no branch sampling for probe events
9847 if (has_branch_stack(event
))
9850 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9851 err
= perf_kprobe_init(event
, is_retprobe
);
9855 event
->destroy
= perf_kprobe_destroy
;
9859 #endif /* CONFIG_KPROBE_EVENTS */
9861 #ifdef CONFIG_UPROBE_EVENTS
9862 PMU_FORMAT_ATTR(ref_ctr_offset
, "config:32-63");
9864 static struct attribute
*uprobe_attrs
[] = {
9865 &format_attr_retprobe
.attr
,
9866 &format_attr_ref_ctr_offset
.attr
,
9870 static struct attribute_group uprobe_format_group
= {
9872 .attrs
= uprobe_attrs
,
9875 static const struct attribute_group
*uprobe_attr_groups
[] = {
9876 &uprobe_format_group
,
9880 static int perf_uprobe_event_init(struct perf_event
*event
);
9881 static struct pmu perf_uprobe
= {
9882 .task_ctx_nr
= perf_sw_context
,
9883 .event_init
= perf_uprobe_event_init
,
9884 .add
= perf_trace_add
,
9885 .del
= perf_trace_del
,
9886 .start
= perf_swevent_start
,
9887 .stop
= perf_swevent_stop
,
9888 .read
= perf_swevent_read
,
9889 .attr_groups
= uprobe_attr_groups
,
9892 static int perf_uprobe_event_init(struct perf_event
*event
)
9895 unsigned long ref_ctr_offset
;
9898 if (event
->attr
.type
!= perf_uprobe
.type
)
9901 if (!perfmon_capable())
9905 * no branch sampling for probe events
9907 if (has_branch_stack(event
))
9910 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9911 ref_ctr_offset
= event
->attr
.config
>> PERF_UPROBE_REF_CTR_OFFSET_SHIFT
;
9912 err
= perf_uprobe_init(event
, ref_ctr_offset
, is_retprobe
);
9916 event
->destroy
= perf_uprobe_destroy
;
9920 #endif /* CONFIG_UPROBE_EVENTS */
9922 static inline void perf_tp_register(void)
9924 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
9925 #ifdef CONFIG_KPROBE_EVENTS
9926 perf_pmu_register(&perf_kprobe
, "kprobe", -1);
9928 #ifdef CONFIG_UPROBE_EVENTS
9929 perf_pmu_register(&perf_uprobe
, "uprobe", -1);
9933 static void perf_event_free_filter(struct perf_event
*event
)
9935 ftrace_profile_free_filter(event
);
9938 #ifdef CONFIG_BPF_SYSCALL
9939 static void bpf_overflow_handler(struct perf_event
*event
,
9940 struct perf_sample_data
*data
,
9941 struct pt_regs
*regs
)
9943 struct bpf_perf_event_data_kern ctx
= {
9947 struct bpf_prog
*prog
;
9950 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
9951 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
9954 prog
= READ_ONCE(event
->prog
);
9956 ret
= bpf_prog_run(prog
, &ctx
);
9959 __this_cpu_dec(bpf_prog_active
);
9963 event
->orig_overflow_handler(event
, data
, regs
);
9966 static int perf_event_set_bpf_handler(struct perf_event
*event
,
9967 struct bpf_prog
*prog
,
9970 if (event
->overflow_handler_context
)
9971 /* hw breakpoint or kernel counter */
9977 if (prog
->type
!= BPF_PROG_TYPE_PERF_EVENT
)
9980 if (event
->attr
.precise_ip
&&
9981 prog
->call_get_stack
&&
9982 (!(event
->attr
.sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
) ||
9983 event
->attr
.exclude_callchain_kernel
||
9984 event
->attr
.exclude_callchain_user
)) {
9986 * On perf_event with precise_ip, calling bpf_get_stack()
9987 * may trigger unwinder warnings and occasional crashes.
9988 * bpf_get_[stack|stackid] works around this issue by using
9989 * callchain attached to perf_sample_data. If the
9990 * perf_event does not full (kernel and user) callchain
9991 * attached to perf_sample_data, do not allow attaching BPF
9992 * program that calls bpf_get_[stack|stackid].
9998 event
->bpf_cookie
= bpf_cookie
;
9999 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
10000 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
10004 static void perf_event_free_bpf_handler(struct perf_event
*event
)
10006 struct bpf_prog
*prog
= event
->prog
;
10011 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
10012 event
->prog
= NULL
;
10013 bpf_prog_put(prog
);
10016 static int perf_event_set_bpf_handler(struct perf_event
*event
,
10017 struct bpf_prog
*prog
,
10020 return -EOPNOTSUPP
;
10022 static void perf_event_free_bpf_handler(struct perf_event
*event
)
10028 * returns true if the event is a tracepoint, or a kprobe/upprobe created
10029 * with perf_event_open()
10031 static inline bool perf_event_is_tracing(struct perf_event
*event
)
10033 if (event
->pmu
== &perf_tracepoint
)
10035 #ifdef CONFIG_KPROBE_EVENTS
10036 if (event
->pmu
== &perf_kprobe
)
10039 #ifdef CONFIG_UPROBE_EVENTS
10040 if (event
->pmu
== &perf_uprobe
)
10046 int perf_event_set_bpf_prog(struct perf_event
*event
, struct bpf_prog
*prog
,
10049 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
10051 if (!perf_event_is_tracing(event
))
10052 return perf_event_set_bpf_handler(event
, prog
, bpf_cookie
);
10054 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
10055 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
10056 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
10057 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
10058 /* bpf programs can only be attached to u/kprobe or tracepoint */
10061 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
10062 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
10063 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
))
10066 /* Kprobe override only works for kprobes, not uprobes. */
10067 if (prog
->kprobe_override
&&
10068 !(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
))
10071 if (is_tracepoint
|| is_syscall_tp
) {
10072 int off
= trace_event_get_offsets(event
->tp_event
);
10074 if (prog
->aux
->max_ctx_offset
> off
)
10078 return perf_event_attach_bpf_prog(event
, prog
, bpf_cookie
);
10081 void perf_event_free_bpf_prog(struct perf_event
*event
)
10083 if (!perf_event_is_tracing(event
)) {
10084 perf_event_free_bpf_handler(event
);
10087 perf_event_detach_bpf_prog(event
);
10092 static inline void perf_tp_register(void)
10096 static void perf_event_free_filter(struct perf_event
*event
)
10100 int perf_event_set_bpf_prog(struct perf_event
*event
, struct bpf_prog
*prog
,
10106 void perf_event_free_bpf_prog(struct perf_event
*event
)
10109 #endif /* CONFIG_EVENT_TRACING */
10111 #ifdef CONFIG_HAVE_HW_BREAKPOINT
10112 void perf_bp_event(struct perf_event
*bp
, void *data
)
10114 struct perf_sample_data sample
;
10115 struct pt_regs
*regs
= data
;
10117 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
10119 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
10120 perf_swevent_event(bp
, 1, &sample
, regs
);
10125 * Allocate a new address filter
10127 static struct perf_addr_filter
*
10128 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
10130 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
10131 struct perf_addr_filter
*filter
;
10133 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
10137 INIT_LIST_HEAD(&filter
->entry
);
10138 list_add_tail(&filter
->entry
, filters
);
10143 static void free_filters_list(struct list_head
*filters
)
10145 struct perf_addr_filter
*filter
, *iter
;
10147 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
10148 path_put(&filter
->path
);
10149 list_del(&filter
->entry
);
10155 * Free existing address filters and optionally install new ones
10157 static void perf_addr_filters_splice(struct perf_event
*event
,
10158 struct list_head
*head
)
10160 unsigned long flags
;
10163 if (!has_addr_filter(event
))
10166 /* don't bother with children, they don't have their own filters */
10170 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
10172 list_splice_init(&event
->addr_filters
.list
, &list
);
10174 list_splice(head
, &event
->addr_filters
.list
);
10176 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
10178 free_filters_list(&list
);
10182 * Scan through mm's vmas and see if one of them matches the
10183 * @filter; if so, adjust filter's address range.
10184 * Called with mm::mmap_lock down for reading.
10186 static void perf_addr_filter_apply(struct perf_addr_filter
*filter
,
10187 struct mm_struct
*mm
,
10188 struct perf_addr_filter_range
*fr
)
10190 struct vm_area_struct
*vma
;
10192 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
10196 if (perf_addr_filter_vma_adjust(filter
, vma
, fr
))
10202 * Update event's address range filters based on the
10203 * task's existing mappings, if any.
10205 static void perf_event_addr_filters_apply(struct perf_event
*event
)
10207 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
10208 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
10209 struct perf_addr_filter
*filter
;
10210 struct mm_struct
*mm
= NULL
;
10211 unsigned int count
= 0;
10212 unsigned long flags
;
10215 * We may observe TASK_TOMBSTONE, which means that the event tear-down
10216 * will stop on the parent's child_mutex that our caller is also holding
10218 if (task
== TASK_TOMBSTONE
)
10221 if (ifh
->nr_file_filters
) {
10222 mm
= get_task_mm(task
);
10226 mmap_read_lock(mm
);
10229 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
10230 list_for_each_entry(filter
, &ifh
->list
, entry
) {
10231 if (filter
->path
.dentry
) {
10233 * Adjust base offset if the filter is associated to a
10234 * binary that needs to be mapped:
10236 event
->addr_filter_ranges
[count
].start
= 0;
10237 event
->addr_filter_ranges
[count
].size
= 0;
10239 perf_addr_filter_apply(filter
, mm
, &event
->addr_filter_ranges
[count
]);
10241 event
->addr_filter_ranges
[count
].start
= filter
->offset
;
10242 event
->addr_filter_ranges
[count
].size
= filter
->size
;
10248 event
->addr_filters_gen
++;
10249 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
10251 if (ifh
->nr_file_filters
) {
10252 mmap_read_unlock(mm
);
10258 perf_event_stop(event
, 1);
10262 * Address range filtering: limiting the data to certain
10263 * instruction address ranges. Filters are ioctl()ed to us from
10264 * userspace as ascii strings.
10266 * Filter string format:
10268 * ACTION RANGE_SPEC
10269 * where ACTION is one of the
10270 * * "filter": limit the trace to this region
10271 * * "start": start tracing from this address
10272 * * "stop": stop tracing at this address/region;
10274 * * for kernel addresses: <start address>[/<size>]
10275 * * for object files: <start address>[/<size>]@</path/to/object/file>
10277 * if <size> is not specified or is zero, the range is treated as a single
10278 * address; not valid for ACTION=="filter".
10292 IF_STATE_ACTION
= 0,
10297 static const match_table_t if_tokens
= {
10298 { IF_ACT_FILTER
, "filter" },
10299 { IF_ACT_START
, "start" },
10300 { IF_ACT_STOP
, "stop" },
10301 { IF_SRC_FILE
, "%u/%u@%s" },
10302 { IF_SRC_KERNEL
, "%u/%u" },
10303 { IF_SRC_FILEADDR
, "%u@%s" },
10304 { IF_SRC_KERNELADDR
, "%u" },
10305 { IF_ACT_NONE
, NULL
},
10309 * Address filter string parser
10312 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
10313 struct list_head
*filters
)
10315 struct perf_addr_filter
*filter
= NULL
;
10316 char *start
, *orig
, *filename
= NULL
;
10317 substring_t args
[MAX_OPT_ARGS
];
10318 int state
= IF_STATE_ACTION
, token
;
10319 unsigned int kernel
= 0;
10322 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
10326 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
10327 static const enum perf_addr_filter_action_t actions
[] = {
10328 [IF_ACT_FILTER
] = PERF_ADDR_FILTER_ACTION_FILTER
,
10329 [IF_ACT_START
] = PERF_ADDR_FILTER_ACTION_START
,
10330 [IF_ACT_STOP
] = PERF_ADDR_FILTER_ACTION_STOP
,
10337 /* filter definition begins */
10338 if (state
== IF_STATE_ACTION
) {
10339 filter
= perf_addr_filter_new(event
, filters
);
10344 token
= match_token(start
, if_tokens
, args
);
10346 case IF_ACT_FILTER
:
10349 if (state
!= IF_STATE_ACTION
)
10352 filter
->action
= actions
[token
];
10353 state
= IF_STATE_SOURCE
;
10356 case IF_SRC_KERNELADDR
:
10357 case IF_SRC_KERNEL
:
10361 case IF_SRC_FILEADDR
:
10363 if (state
!= IF_STATE_SOURCE
)
10367 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
10371 if (token
== IF_SRC_KERNEL
|| token
== IF_SRC_FILE
) {
10373 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
10378 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
10379 int fpos
= token
== IF_SRC_FILE
? 2 : 1;
10382 filename
= match_strdup(&args
[fpos
]);
10389 state
= IF_STATE_END
;
10397 * Filter definition is fully parsed, validate and install it.
10398 * Make sure that it doesn't contradict itself or the event's
10401 if (state
== IF_STATE_END
) {
10403 if (kernel
&& event
->attr
.exclude_kernel
)
10407 * ACTION "filter" must have a non-zero length region
10410 if (filter
->action
== PERF_ADDR_FILTER_ACTION_FILTER
&&
10419 * For now, we only support file-based filters
10420 * in per-task events; doing so for CPU-wide
10421 * events requires additional context switching
10422 * trickery, since same object code will be
10423 * mapped at different virtual addresses in
10424 * different processes.
10427 if (!event
->ctx
->task
)
10430 /* look up the path and grab its inode */
10431 ret
= kern_path(filename
, LOOKUP_FOLLOW
,
10437 if (!filter
->path
.dentry
||
10438 !S_ISREG(d_inode(filter
->path
.dentry
)
10442 event
->addr_filters
.nr_file_filters
++;
10445 /* ready to consume more filters */
10446 state
= IF_STATE_ACTION
;
10451 if (state
!= IF_STATE_ACTION
)
10461 free_filters_list(filters
);
10468 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
10470 LIST_HEAD(filters
);
10474 * Since this is called in perf_ioctl() path, we're already holding
10477 lockdep_assert_held(&event
->ctx
->mutex
);
10479 if (WARN_ON_ONCE(event
->parent
))
10482 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
10484 goto fail_clear_files
;
10486 ret
= event
->pmu
->addr_filters_validate(&filters
);
10488 goto fail_free_filters
;
10490 /* remove existing filters, if any */
10491 perf_addr_filters_splice(event
, &filters
);
10493 /* install new filters */
10494 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
10499 free_filters_list(&filters
);
10502 event
->addr_filters
.nr_file_filters
= 0;
10507 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
10512 filter_str
= strndup_user(arg
, PAGE_SIZE
);
10513 if (IS_ERR(filter_str
))
10514 return PTR_ERR(filter_str
);
10516 #ifdef CONFIG_EVENT_TRACING
10517 if (perf_event_is_tracing(event
)) {
10518 struct perf_event_context
*ctx
= event
->ctx
;
10521 * Beware, here be dragons!!
10523 * the tracepoint muck will deadlock against ctx->mutex, but
10524 * the tracepoint stuff does not actually need it. So
10525 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
10526 * already have a reference on ctx.
10528 * This can result in event getting moved to a different ctx,
10529 * but that does not affect the tracepoint state.
10531 mutex_unlock(&ctx
->mutex
);
10532 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
10533 mutex_lock(&ctx
->mutex
);
10536 if (has_addr_filter(event
))
10537 ret
= perf_event_set_addr_filter(event
, filter_str
);
10544 * hrtimer based swevent callback
10547 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
10549 enum hrtimer_restart ret
= HRTIMER_RESTART
;
10550 struct perf_sample_data data
;
10551 struct pt_regs
*regs
;
10552 struct perf_event
*event
;
10555 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
10557 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
10558 return HRTIMER_NORESTART
;
10560 event
->pmu
->read(event
);
10562 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
10563 regs
= get_irq_regs();
10565 if (regs
&& !perf_exclude_event(event
, regs
)) {
10566 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
10567 if (__perf_event_overflow(event
, 1, &data
, regs
))
10568 ret
= HRTIMER_NORESTART
;
10571 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
10572 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
10577 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
10579 struct hw_perf_event
*hwc
= &event
->hw
;
10582 if (!is_sampling_event(event
))
10585 period
= local64_read(&hwc
->period_left
);
10590 local64_set(&hwc
->period_left
, 0);
10592 period
= max_t(u64
, 10000, hwc
->sample_period
);
10594 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
10595 HRTIMER_MODE_REL_PINNED_HARD
);
10598 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
10600 struct hw_perf_event
*hwc
= &event
->hw
;
10602 if (is_sampling_event(event
)) {
10603 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
10604 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
10606 hrtimer_cancel(&hwc
->hrtimer
);
10610 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
10612 struct hw_perf_event
*hwc
= &event
->hw
;
10614 if (!is_sampling_event(event
))
10617 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_HARD
);
10618 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
10621 * Since hrtimers have a fixed rate, we can do a static freq->period
10622 * mapping and avoid the whole period adjust feedback stuff.
10624 if (event
->attr
.freq
) {
10625 long freq
= event
->attr
.sample_freq
;
10627 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
10628 hwc
->sample_period
= event
->attr
.sample_period
;
10629 local64_set(&hwc
->period_left
, hwc
->sample_period
);
10630 hwc
->last_period
= hwc
->sample_period
;
10631 event
->attr
.freq
= 0;
10636 * Software event: cpu wall time clock
10639 static void cpu_clock_event_update(struct perf_event
*event
)
10644 now
= local_clock();
10645 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
10646 local64_add(now
- prev
, &event
->count
);
10649 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
10651 local64_set(&event
->hw
.prev_count
, local_clock());
10652 perf_swevent_start_hrtimer(event
);
10655 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
10657 perf_swevent_cancel_hrtimer(event
);
10658 cpu_clock_event_update(event
);
10661 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
10663 if (flags
& PERF_EF_START
)
10664 cpu_clock_event_start(event
, flags
);
10665 perf_event_update_userpage(event
);
10670 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
10672 cpu_clock_event_stop(event
, flags
);
10675 static void cpu_clock_event_read(struct perf_event
*event
)
10677 cpu_clock_event_update(event
);
10680 static int cpu_clock_event_init(struct perf_event
*event
)
10682 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
10685 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
10689 * no branch sampling for software events
10691 if (has_branch_stack(event
))
10692 return -EOPNOTSUPP
;
10694 perf_swevent_init_hrtimer(event
);
10699 static struct pmu perf_cpu_clock
= {
10700 .task_ctx_nr
= perf_sw_context
,
10702 .capabilities
= PERF_PMU_CAP_NO_NMI
,
10704 .event_init
= cpu_clock_event_init
,
10705 .add
= cpu_clock_event_add
,
10706 .del
= cpu_clock_event_del
,
10707 .start
= cpu_clock_event_start
,
10708 .stop
= cpu_clock_event_stop
,
10709 .read
= cpu_clock_event_read
,
10713 * Software event: task time clock
10716 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
10721 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
10722 delta
= now
- prev
;
10723 local64_add(delta
, &event
->count
);
10726 static void task_clock_event_start(struct perf_event
*event
, int flags
)
10728 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
10729 perf_swevent_start_hrtimer(event
);
10732 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
10734 perf_swevent_cancel_hrtimer(event
);
10735 task_clock_event_update(event
, event
->ctx
->time
);
10738 static int task_clock_event_add(struct perf_event
*event
, int flags
)
10740 if (flags
& PERF_EF_START
)
10741 task_clock_event_start(event
, flags
);
10742 perf_event_update_userpage(event
);
10747 static void task_clock_event_del(struct perf_event
*event
, int flags
)
10749 task_clock_event_stop(event
, PERF_EF_UPDATE
);
10752 static void task_clock_event_read(struct perf_event
*event
)
10754 u64 now
= perf_clock();
10755 u64 delta
= now
- event
->ctx
->timestamp
;
10756 u64 time
= event
->ctx
->time
+ delta
;
10758 task_clock_event_update(event
, time
);
10761 static int task_clock_event_init(struct perf_event
*event
)
10763 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
10766 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
10770 * no branch sampling for software events
10772 if (has_branch_stack(event
))
10773 return -EOPNOTSUPP
;
10775 perf_swevent_init_hrtimer(event
);
10780 static struct pmu perf_task_clock
= {
10781 .task_ctx_nr
= perf_sw_context
,
10783 .capabilities
= PERF_PMU_CAP_NO_NMI
,
10785 .event_init
= task_clock_event_init
,
10786 .add
= task_clock_event_add
,
10787 .del
= task_clock_event_del
,
10788 .start
= task_clock_event_start
,
10789 .stop
= task_clock_event_stop
,
10790 .read
= task_clock_event_read
,
10793 static void perf_pmu_nop_void(struct pmu
*pmu
)
10797 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
10801 static int perf_pmu_nop_int(struct pmu
*pmu
)
10806 static int perf_event_nop_int(struct perf_event
*event
, u64 value
)
10811 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
10813 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
10815 __this_cpu_write(nop_txn_flags
, flags
);
10817 if (flags
& ~PERF_PMU_TXN_ADD
)
10820 perf_pmu_disable(pmu
);
10823 static int perf_pmu_commit_txn(struct pmu
*pmu
)
10825 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10827 __this_cpu_write(nop_txn_flags
, 0);
10829 if (flags
& ~PERF_PMU_TXN_ADD
)
10832 perf_pmu_enable(pmu
);
10836 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
10838 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10840 __this_cpu_write(nop_txn_flags
, 0);
10842 if (flags
& ~PERF_PMU_TXN_ADD
)
10845 perf_pmu_enable(pmu
);
10848 static int perf_event_idx_default(struct perf_event
*event
)
10854 * Ensures all contexts with the same task_ctx_nr have the same
10855 * pmu_cpu_context too.
10857 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
10864 list_for_each_entry(pmu
, &pmus
, entry
) {
10865 if (pmu
->task_ctx_nr
== ctxn
)
10866 return pmu
->pmu_cpu_context
;
10872 static void free_pmu_context(struct pmu
*pmu
)
10875 * Static contexts such as perf_sw_context have a global lifetime
10876 * and may be shared between different PMUs. Avoid freeing them
10877 * when a single PMU is going away.
10879 if (pmu
->task_ctx_nr
> perf_invalid_context
)
10882 free_percpu(pmu
->pmu_cpu_context
);
10886 * Let userspace know that this PMU supports address range filtering:
10888 static ssize_t
nr_addr_filters_show(struct device
*dev
,
10889 struct device_attribute
*attr
,
10892 struct pmu
*pmu
= dev_get_drvdata(dev
);
10894 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
10896 DEVICE_ATTR_RO(nr_addr_filters
);
10898 static struct idr pmu_idr
;
10901 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
10903 struct pmu
*pmu
= dev_get_drvdata(dev
);
10905 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
10907 static DEVICE_ATTR_RO(type
);
10910 perf_event_mux_interval_ms_show(struct device
*dev
,
10911 struct device_attribute
*attr
,
10914 struct pmu
*pmu
= dev_get_drvdata(dev
);
10916 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
10919 static DEFINE_MUTEX(mux_interval_mutex
);
10922 perf_event_mux_interval_ms_store(struct device
*dev
,
10923 struct device_attribute
*attr
,
10924 const char *buf
, size_t count
)
10926 struct pmu
*pmu
= dev_get_drvdata(dev
);
10927 int timer
, cpu
, ret
;
10929 ret
= kstrtoint(buf
, 0, &timer
);
10936 /* same value, noting to do */
10937 if (timer
== pmu
->hrtimer_interval_ms
)
10940 mutex_lock(&mux_interval_mutex
);
10941 pmu
->hrtimer_interval_ms
= timer
;
10943 /* update all cpuctx for this PMU */
10945 for_each_online_cpu(cpu
) {
10946 struct perf_cpu_context
*cpuctx
;
10947 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10948 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
10950 cpu_function_call(cpu
,
10951 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
10953 cpus_read_unlock();
10954 mutex_unlock(&mux_interval_mutex
);
10958 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
10960 static struct attribute
*pmu_dev_attrs
[] = {
10961 &dev_attr_type
.attr
,
10962 &dev_attr_perf_event_mux_interval_ms
.attr
,
10965 ATTRIBUTE_GROUPS(pmu_dev
);
10967 static int pmu_bus_running
;
10968 static struct bus_type pmu_bus
= {
10969 .name
= "event_source",
10970 .dev_groups
= pmu_dev_groups
,
10973 static void pmu_dev_release(struct device
*dev
)
10978 static int pmu_dev_alloc(struct pmu
*pmu
)
10982 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
10986 pmu
->dev
->groups
= pmu
->attr_groups
;
10987 device_initialize(pmu
->dev
);
10988 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
10992 dev_set_drvdata(pmu
->dev
, pmu
);
10993 pmu
->dev
->bus
= &pmu_bus
;
10994 pmu
->dev
->release
= pmu_dev_release
;
10995 ret
= device_add(pmu
->dev
);
10999 /* For PMUs with address filters, throw in an extra attribute: */
11000 if (pmu
->nr_addr_filters
)
11001 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
11006 if (pmu
->attr_update
)
11007 ret
= sysfs_update_groups(&pmu
->dev
->kobj
, pmu
->attr_update
);
11016 device_del(pmu
->dev
);
11019 put_device(pmu
->dev
);
11023 static struct lock_class_key cpuctx_mutex
;
11024 static struct lock_class_key cpuctx_lock
;
11026 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
11028 int cpu
, ret
, max
= PERF_TYPE_MAX
;
11030 mutex_lock(&pmus_lock
);
11032 pmu
->pmu_disable_count
= alloc_percpu(int);
11033 if (!pmu
->pmu_disable_count
)
11041 if (type
!= PERF_TYPE_SOFTWARE
) {
11045 ret
= idr_alloc(&pmu_idr
, pmu
, max
, 0, GFP_KERNEL
);
11049 WARN_ON(type
>= 0 && ret
!= type
);
11055 if (pmu_bus_running
) {
11056 ret
= pmu_dev_alloc(pmu
);
11062 if (pmu
->task_ctx_nr
== perf_hw_context
) {
11063 static int hw_context_taken
= 0;
11066 * Other than systems with heterogeneous CPUs, it never makes
11067 * sense for two PMUs to share perf_hw_context. PMUs which are
11068 * uncore must use perf_invalid_context.
11070 if (WARN_ON_ONCE(hw_context_taken
&&
11071 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
11072 pmu
->task_ctx_nr
= perf_invalid_context
;
11074 hw_context_taken
= 1;
11077 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
11078 if (pmu
->pmu_cpu_context
)
11079 goto got_cpu_context
;
11082 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
11083 if (!pmu
->pmu_cpu_context
)
11086 for_each_possible_cpu(cpu
) {
11087 struct perf_cpu_context
*cpuctx
;
11089 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11090 __perf_event_init_context(&cpuctx
->ctx
);
11091 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
11092 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
11093 cpuctx
->ctx
.pmu
= pmu
;
11094 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
11096 __perf_mux_hrtimer_init(cpuctx
, cpu
);
11098 cpuctx
->heap_size
= ARRAY_SIZE(cpuctx
->heap_default
);
11099 cpuctx
->heap
= cpuctx
->heap_default
;
11103 if (!pmu
->start_txn
) {
11104 if (pmu
->pmu_enable
) {
11106 * If we have pmu_enable/pmu_disable calls, install
11107 * transaction stubs that use that to try and batch
11108 * hardware accesses.
11110 pmu
->start_txn
= perf_pmu_start_txn
;
11111 pmu
->commit_txn
= perf_pmu_commit_txn
;
11112 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
11114 pmu
->start_txn
= perf_pmu_nop_txn
;
11115 pmu
->commit_txn
= perf_pmu_nop_int
;
11116 pmu
->cancel_txn
= perf_pmu_nop_void
;
11120 if (!pmu
->pmu_enable
) {
11121 pmu
->pmu_enable
= perf_pmu_nop_void
;
11122 pmu
->pmu_disable
= perf_pmu_nop_void
;
11125 if (!pmu
->check_period
)
11126 pmu
->check_period
= perf_event_nop_int
;
11128 if (!pmu
->event_idx
)
11129 pmu
->event_idx
= perf_event_idx_default
;
11132 * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
11133 * since these cannot be in the IDR. This way the linear search
11134 * is fast, provided a valid software event is provided.
11136 if (type
== PERF_TYPE_SOFTWARE
|| !name
)
11137 list_add_rcu(&pmu
->entry
, &pmus
);
11139 list_add_tail_rcu(&pmu
->entry
, &pmus
);
11141 atomic_set(&pmu
->exclusive_cnt
, 0);
11144 mutex_unlock(&pmus_lock
);
11149 device_del(pmu
->dev
);
11150 put_device(pmu
->dev
);
11153 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
11154 idr_remove(&pmu_idr
, pmu
->type
);
11157 free_percpu(pmu
->pmu_disable_count
);
11160 EXPORT_SYMBOL_GPL(perf_pmu_register
);
11162 void perf_pmu_unregister(struct pmu
*pmu
)
11164 mutex_lock(&pmus_lock
);
11165 list_del_rcu(&pmu
->entry
);
11168 * We dereference the pmu list under both SRCU and regular RCU, so
11169 * synchronize against both of those.
11171 synchronize_srcu(&pmus_srcu
);
11174 free_percpu(pmu
->pmu_disable_count
);
11175 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
11176 idr_remove(&pmu_idr
, pmu
->type
);
11177 if (pmu_bus_running
) {
11178 if (pmu
->nr_addr_filters
)
11179 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
11180 device_del(pmu
->dev
);
11181 put_device(pmu
->dev
);
11183 free_pmu_context(pmu
);
11184 mutex_unlock(&pmus_lock
);
11186 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
11188 static inline bool has_extended_regs(struct perf_event
*event
)
11190 return (event
->attr
.sample_regs_user
& PERF_REG_EXTENDED_MASK
) ||
11191 (event
->attr
.sample_regs_intr
& PERF_REG_EXTENDED_MASK
);
11194 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
11196 struct perf_event_context
*ctx
= NULL
;
11199 if (!try_module_get(pmu
->module
))
11203 * A number of pmu->event_init() methods iterate the sibling_list to,
11204 * for example, validate if the group fits on the PMU. Therefore,
11205 * if this is a sibling event, acquire the ctx->mutex to protect
11206 * the sibling_list.
11208 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
11210 * This ctx->mutex can nest when we're called through
11211 * inheritance. See the perf_event_ctx_lock_nested() comment.
11213 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
11214 SINGLE_DEPTH_NESTING
);
11219 ret
= pmu
->event_init(event
);
11222 perf_event_ctx_unlock(event
->group_leader
, ctx
);
11225 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXTENDED_REGS
) &&
11226 has_extended_regs(event
))
11229 if (pmu
->capabilities
& PERF_PMU_CAP_NO_EXCLUDE
&&
11230 event_has_any_exclude_flag(event
))
11233 if (ret
&& event
->destroy
)
11234 event
->destroy(event
);
11238 module_put(pmu
->module
);
11243 static struct pmu
*perf_init_event(struct perf_event
*event
)
11245 bool extended_type
= false;
11246 int idx
, type
, ret
;
11249 idx
= srcu_read_lock(&pmus_srcu
);
11251 /* Try parent's PMU first: */
11252 if (event
->parent
&& event
->parent
->pmu
) {
11253 pmu
= event
->parent
->pmu
;
11254 ret
= perf_try_init_event(pmu
, event
);
11260 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
11261 * are often aliases for PERF_TYPE_RAW.
11263 type
= event
->attr
.type
;
11264 if (type
== PERF_TYPE_HARDWARE
|| type
== PERF_TYPE_HW_CACHE
) {
11265 type
= event
->attr
.config
>> PERF_PMU_TYPE_SHIFT
;
11267 type
= PERF_TYPE_RAW
;
11269 extended_type
= true;
11270 event
->attr
.config
&= PERF_HW_EVENT_MASK
;
11276 pmu
= idr_find(&pmu_idr
, type
);
11279 if (event
->attr
.type
!= type
&& type
!= PERF_TYPE_RAW
&&
11280 !(pmu
->capabilities
& PERF_PMU_CAP_EXTENDED_HW_TYPE
))
11283 ret
= perf_try_init_event(pmu
, event
);
11284 if (ret
== -ENOENT
&& event
->attr
.type
!= type
&& !extended_type
) {
11285 type
= event
->attr
.type
;
11290 pmu
= ERR_PTR(ret
);
11295 list_for_each_entry_rcu(pmu
, &pmus
, entry
, lockdep_is_held(&pmus_srcu
)) {
11296 ret
= perf_try_init_event(pmu
, event
);
11300 if (ret
!= -ENOENT
) {
11301 pmu
= ERR_PTR(ret
);
11306 pmu
= ERR_PTR(-ENOENT
);
11308 srcu_read_unlock(&pmus_srcu
, idx
);
11313 static void attach_sb_event(struct perf_event
*event
)
11315 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
11317 raw_spin_lock(&pel
->lock
);
11318 list_add_rcu(&event
->sb_list
, &pel
->list
);
11319 raw_spin_unlock(&pel
->lock
);
11323 * We keep a list of all !task (and therefore per-cpu) events
11324 * that need to receive side-band records.
11326 * This avoids having to scan all the various PMU per-cpu contexts
11327 * looking for them.
11329 static void account_pmu_sb_event(struct perf_event
*event
)
11331 if (is_sb_event(event
))
11332 attach_sb_event(event
);
11335 static void account_event_cpu(struct perf_event
*event
, int cpu
)
11340 if (is_cgroup_event(event
))
11341 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
11344 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
11345 static void account_freq_event_nohz(void)
11347 #ifdef CONFIG_NO_HZ_FULL
11348 /* Lock so we don't race with concurrent unaccount */
11349 spin_lock(&nr_freq_lock
);
11350 if (atomic_inc_return(&nr_freq_events
) == 1)
11351 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
11352 spin_unlock(&nr_freq_lock
);
11356 static void account_freq_event(void)
11358 if (tick_nohz_full_enabled())
11359 account_freq_event_nohz();
11361 atomic_inc(&nr_freq_events
);
11365 static void account_event(struct perf_event
*event
)
11372 if (event
->attach_state
& (PERF_ATTACH_TASK
| PERF_ATTACH_SCHED_CB
))
11374 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
11375 atomic_inc(&nr_mmap_events
);
11376 if (event
->attr
.build_id
)
11377 atomic_inc(&nr_build_id_events
);
11378 if (event
->attr
.comm
)
11379 atomic_inc(&nr_comm_events
);
11380 if (event
->attr
.namespaces
)
11381 atomic_inc(&nr_namespaces_events
);
11382 if (event
->attr
.cgroup
)
11383 atomic_inc(&nr_cgroup_events
);
11384 if (event
->attr
.task
)
11385 atomic_inc(&nr_task_events
);
11386 if (event
->attr
.freq
)
11387 account_freq_event();
11388 if (event
->attr
.context_switch
) {
11389 atomic_inc(&nr_switch_events
);
11392 if (has_branch_stack(event
))
11394 if (is_cgroup_event(event
))
11396 if (event
->attr
.ksymbol
)
11397 atomic_inc(&nr_ksymbol_events
);
11398 if (event
->attr
.bpf_event
)
11399 atomic_inc(&nr_bpf_events
);
11400 if (event
->attr
.text_poke
)
11401 atomic_inc(&nr_text_poke_events
);
11405 * We need the mutex here because static_branch_enable()
11406 * must complete *before* the perf_sched_count increment
11409 if (atomic_inc_not_zero(&perf_sched_count
))
11412 mutex_lock(&perf_sched_mutex
);
11413 if (!atomic_read(&perf_sched_count
)) {
11414 static_branch_enable(&perf_sched_events
);
11416 * Guarantee that all CPUs observe they key change and
11417 * call the perf scheduling hooks before proceeding to
11418 * install events that need them.
11423 * Now that we have waited for the sync_sched(), allow further
11424 * increments to by-pass the mutex.
11426 atomic_inc(&perf_sched_count
);
11427 mutex_unlock(&perf_sched_mutex
);
11431 account_event_cpu(event
, event
->cpu
);
11433 account_pmu_sb_event(event
);
11437 * Allocate and initialize an event structure
11439 static struct perf_event
*
11440 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
11441 struct task_struct
*task
,
11442 struct perf_event
*group_leader
,
11443 struct perf_event
*parent_event
,
11444 perf_overflow_handler_t overflow_handler
,
11445 void *context
, int cgroup_fd
)
11448 struct perf_event
*event
;
11449 struct hw_perf_event
*hwc
;
11450 long err
= -EINVAL
;
11453 if ((unsigned)cpu
>= nr_cpu_ids
) {
11454 if (!task
|| cpu
!= -1)
11455 return ERR_PTR(-EINVAL
);
11457 if (attr
->sigtrap
&& !task
) {
11458 /* Requires a task: avoid signalling random tasks. */
11459 return ERR_PTR(-EINVAL
);
11462 node
= (cpu
>= 0) ? cpu_to_node(cpu
) : -1;
11463 event
= kmem_cache_alloc_node(perf_event_cache
, GFP_KERNEL
| __GFP_ZERO
,
11466 return ERR_PTR(-ENOMEM
);
11469 * Single events are their own group leaders, with an
11470 * empty sibling list:
11473 group_leader
= event
;
11475 mutex_init(&event
->child_mutex
);
11476 INIT_LIST_HEAD(&event
->child_list
);
11478 INIT_LIST_HEAD(&event
->event_entry
);
11479 INIT_LIST_HEAD(&event
->sibling_list
);
11480 INIT_LIST_HEAD(&event
->active_list
);
11481 init_event_group(event
);
11482 INIT_LIST_HEAD(&event
->rb_entry
);
11483 INIT_LIST_HEAD(&event
->active_entry
);
11484 INIT_LIST_HEAD(&event
->addr_filters
.list
);
11485 INIT_HLIST_NODE(&event
->hlist_entry
);
11488 init_waitqueue_head(&event
->waitq
);
11489 event
->pending_disable
= -1;
11490 init_irq_work(&event
->pending
, perf_pending_event
);
11492 mutex_init(&event
->mmap_mutex
);
11493 raw_spin_lock_init(&event
->addr_filters
.lock
);
11495 atomic_long_set(&event
->refcount
, 1);
11497 event
->attr
= *attr
;
11498 event
->group_leader
= group_leader
;
11502 event
->parent
= parent_event
;
11504 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
11505 event
->id
= atomic64_inc_return(&perf_event_id
);
11507 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11509 if (event
->attr
.sigtrap
)
11510 atomic_set(&event
->event_limit
, 1);
11513 event
->attach_state
= PERF_ATTACH_TASK
;
11515 * XXX pmu::event_init needs to know what task to account to
11516 * and we cannot use the ctx information because we need the
11517 * pmu before we get a ctx.
11519 event
->hw
.target
= get_task_struct(task
);
11522 event
->clock
= &local_clock
;
11524 event
->clock
= parent_event
->clock
;
11526 if (!overflow_handler
&& parent_event
) {
11527 overflow_handler
= parent_event
->overflow_handler
;
11528 context
= parent_event
->overflow_handler_context
;
11529 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
11530 if (overflow_handler
== bpf_overflow_handler
) {
11531 struct bpf_prog
*prog
= parent_event
->prog
;
11533 bpf_prog_inc(prog
);
11534 event
->prog
= prog
;
11535 event
->orig_overflow_handler
=
11536 parent_event
->orig_overflow_handler
;
11541 if (overflow_handler
) {
11542 event
->overflow_handler
= overflow_handler
;
11543 event
->overflow_handler_context
= context
;
11544 } else if (is_write_backward(event
)){
11545 event
->overflow_handler
= perf_event_output_backward
;
11546 event
->overflow_handler_context
= NULL
;
11548 event
->overflow_handler
= perf_event_output_forward
;
11549 event
->overflow_handler_context
= NULL
;
11552 perf_event__state_init(event
);
11557 hwc
->sample_period
= attr
->sample_period
;
11558 if (attr
->freq
&& attr
->sample_freq
)
11559 hwc
->sample_period
= 1;
11560 hwc
->last_period
= hwc
->sample_period
;
11562 local64_set(&hwc
->period_left
, hwc
->sample_period
);
11565 * We currently do not support PERF_SAMPLE_READ on inherited events.
11566 * See perf_output_read().
11568 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
11571 if (!has_branch_stack(event
))
11572 event
->attr
.branch_sample_type
= 0;
11574 pmu
= perf_init_event(event
);
11576 err
= PTR_ERR(pmu
);
11581 * Disallow uncore-cgroup events, they don't make sense as the cgroup will
11582 * be different on other CPUs in the uncore mask.
11584 if (pmu
->task_ctx_nr
== perf_invalid_context
&& cgroup_fd
!= -1) {
11589 if (event
->attr
.aux_output
&&
11590 !(pmu
->capabilities
& PERF_PMU_CAP_AUX_OUTPUT
)) {
11595 if (cgroup_fd
!= -1) {
11596 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
11601 err
= exclusive_event_init(event
);
11605 if (has_addr_filter(event
)) {
11606 event
->addr_filter_ranges
= kcalloc(pmu
->nr_addr_filters
,
11607 sizeof(struct perf_addr_filter_range
),
11609 if (!event
->addr_filter_ranges
) {
11615 * Clone the parent's vma offsets: they are valid until exec()
11616 * even if the mm is not shared with the parent.
11618 if (event
->parent
) {
11619 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
11621 raw_spin_lock_irq(&ifh
->lock
);
11622 memcpy(event
->addr_filter_ranges
,
11623 event
->parent
->addr_filter_ranges
,
11624 pmu
->nr_addr_filters
* sizeof(struct perf_addr_filter_range
));
11625 raw_spin_unlock_irq(&ifh
->lock
);
11628 /* force hw sync on the address filters */
11629 event
->addr_filters_gen
= 1;
11632 if (!event
->parent
) {
11633 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
11634 err
= get_callchain_buffers(attr
->sample_max_stack
);
11636 goto err_addr_filters
;
11640 err
= security_perf_event_alloc(event
);
11642 goto err_callchain_buffer
;
11644 /* symmetric to unaccount_event() in _free_event() */
11645 account_event(event
);
11649 err_callchain_buffer
:
11650 if (!event
->parent
) {
11651 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
11652 put_callchain_buffers();
11655 kfree(event
->addr_filter_ranges
);
11658 exclusive_event_destroy(event
);
11661 if (is_cgroup_event(event
))
11662 perf_detach_cgroup(event
);
11663 if (event
->destroy
)
11664 event
->destroy(event
);
11665 module_put(pmu
->module
);
11668 put_pid_ns(event
->ns
);
11669 if (event
->hw
.target
)
11670 put_task_struct(event
->hw
.target
);
11671 kmem_cache_free(perf_event_cache
, event
);
11673 return ERR_PTR(err
);
11676 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
11677 struct perf_event_attr
*attr
)
11682 /* Zero the full structure, so that a short copy will be nice. */
11683 memset(attr
, 0, sizeof(*attr
));
11685 ret
= get_user(size
, &uattr
->size
);
11689 /* ABI compatibility quirk: */
11691 size
= PERF_ATTR_SIZE_VER0
;
11692 if (size
< PERF_ATTR_SIZE_VER0
|| size
> PAGE_SIZE
)
11695 ret
= copy_struct_from_user(attr
, sizeof(*attr
), uattr
, size
);
11704 if (attr
->__reserved_1
|| attr
->__reserved_2
|| attr
->__reserved_3
)
11707 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
11710 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
11713 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
11714 u64 mask
= attr
->branch_sample_type
;
11716 /* only using defined bits */
11717 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
11720 /* at least one branch bit must be set */
11721 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
11724 /* propagate priv level, when not set for branch */
11725 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
11727 /* exclude_kernel checked on syscall entry */
11728 if (!attr
->exclude_kernel
)
11729 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
11731 if (!attr
->exclude_user
)
11732 mask
|= PERF_SAMPLE_BRANCH_USER
;
11734 if (!attr
->exclude_hv
)
11735 mask
|= PERF_SAMPLE_BRANCH_HV
;
11737 * adjust user setting (for HW filter setup)
11739 attr
->branch_sample_type
= mask
;
11741 /* privileged levels capture (kernel, hv): check permissions */
11742 if (mask
& PERF_SAMPLE_BRANCH_PERM_PLM
) {
11743 ret
= perf_allow_kernel(attr
);
11749 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
11750 ret
= perf_reg_validate(attr
->sample_regs_user
);
11755 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
11756 if (!arch_perf_have_user_stack_dump())
11760 * We have __u32 type for the size, but so far
11761 * we can only use __u16 as maximum due to the
11762 * __u16 sample size limit.
11764 if (attr
->sample_stack_user
>= USHRT_MAX
)
11766 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
11770 if (!attr
->sample_max_stack
)
11771 attr
->sample_max_stack
= sysctl_perf_event_max_stack
;
11773 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
11774 ret
= perf_reg_validate(attr
->sample_regs_intr
);
11776 #ifndef CONFIG_CGROUP_PERF
11777 if (attr
->sample_type
& PERF_SAMPLE_CGROUP
)
11780 if ((attr
->sample_type
& PERF_SAMPLE_WEIGHT
) &&
11781 (attr
->sample_type
& PERF_SAMPLE_WEIGHT_STRUCT
))
11784 if (!attr
->inherit
&& attr
->inherit_thread
)
11787 if (attr
->remove_on_exec
&& attr
->enable_on_exec
)
11790 if (attr
->sigtrap
&& !attr
->remove_on_exec
)
11797 put_user(sizeof(*attr
), &uattr
->size
);
11803 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
11805 struct perf_buffer
*rb
= NULL
;
11811 /* don't allow circular references */
11812 if (event
== output_event
)
11816 * Don't allow cross-cpu buffers
11818 if (output_event
->cpu
!= event
->cpu
)
11822 * If its not a per-cpu rb, it must be the same task.
11824 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
11828 * Mixing clocks in the same buffer is trouble you don't need.
11830 if (output_event
->clock
!= event
->clock
)
11834 * Either writing ring buffer from beginning or from end.
11835 * Mixing is not allowed.
11837 if (is_write_backward(output_event
) != is_write_backward(event
))
11841 * If both events generate aux data, they must be on the same PMU
11843 if (has_aux(event
) && has_aux(output_event
) &&
11844 event
->pmu
!= output_event
->pmu
)
11848 mutex_lock(&event
->mmap_mutex
);
11849 /* Can't redirect output if we've got an active mmap() */
11850 if (atomic_read(&event
->mmap_count
))
11853 if (output_event
) {
11854 /* get the rb we want to redirect to */
11855 rb
= ring_buffer_get(output_event
);
11860 ring_buffer_attach(event
, rb
);
11864 mutex_unlock(&event
->mmap_mutex
);
11870 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
11876 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
11879 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
11881 bool nmi_safe
= false;
11884 case CLOCK_MONOTONIC
:
11885 event
->clock
= &ktime_get_mono_fast_ns
;
11889 case CLOCK_MONOTONIC_RAW
:
11890 event
->clock
= &ktime_get_raw_fast_ns
;
11894 case CLOCK_REALTIME
:
11895 event
->clock
= &ktime_get_real_ns
;
11898 case CLOCK_BOOTTIME
:
11899 event
->clock
= &ktime_get_boottime_ns
;
11903 event
->clock
= &ktime_get_clocktai_ns
;
11910 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
11917 * Variation on perf_event_ctx_lock_nested(), except we take two context
11920 static struct perf_event_context
*
11921 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
11922 struct perf_event_context
*ctx
)
11924 struct perf_event_context
*gctx
;
11928 gctx
= READ_ONCE(group_leader
->ctx
);
11929 if (!refcount_inc_not_zero(&gctx
->refcount
)) {
11935 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
11937 if (group_leader
->ctx
!= gctx
) {
11938 mutex_unlock(&ctx
->mutex
);
11939 mutex_unlock(&gctx
->mutex
);
11948 perf_check_permission(struct perf_event_attr
*attr
, struct task_struct
*task
)
11950 unsigned int ptrace_mode
= PTRACE_MODE_READ_REALCREDS
;
11951 bool is_capable
= perfmon_capable();
11953 if (attr
->sigtrap
) {
11955 * perf_event_attr::sigtrap sends signals to the other task.
11956 * Require the current task to also have CAP_KILL.
11959 is_capable
&= ns_capable(__task_cred(task
)->user_ns
, CAP_KILL
);
11963 * If the required capabilities aren't available, checks for
11964 * ptrace permissions: upgrade to ATTACH, since sending signals
11965 * can effectively change the target task.
11967 ptrace_mode
= PTRACE_MODE_ATTACH_REALCREDS
;
11971 * Preserve ptrace permission check for backwards compatibility. The
11972 * ptrace check also includes checks that the current task and other
11973 * task have matching uids, and is therefore not done here explicitly.
11975 return is_capable
|| ptrace_may_access(task
, ptrace_mode
);
11979 * sys_perf_event_open - open a performance event, associate it to a task/cpu
11981 * @attr_uptr: event_id type attributes for monitoring/sampling
11984 * @group_fd: group leader event fd
11985 * @flags: perf event open flags
11987 SYSCALL_DEFINE5(perf_event_open
,
11988 struct perf_event_attr __user
*, attr_uptr
,
11989 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
11991 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
11992 struct perf_event
*event
, *sibling
;
11993 struct perf_event_attr attr
;
11994 struct perf_event_context
*ctx
, *gctx
;
11995 struct file
*event_file
= NULL
;
11996 struct fd group
= {NULL
, 0};
11997 struct task_struct
*task
= NULL
;
12000 int move_group
= 0;
12002 int f_flags
= O_RDWR
;
12003 int cgroup_fd
= -1;
12005 /* for future expandability... */
12006 if (flags
& ~PERF_FLAG_ALL
)
12009 /* Do we allow access to perf_event_open(2) ? */
12010 err
= security_perf_event_open(&attr
, PERF_SECURITY_OPEN
);
12014 err
= perf_copy_attr(attr_uptr
, &attr
);
12018 if (!attr
.exclude_kernel
) {
12019 err
= perf_allow_kernel(&attr
);
12024 if (attr
.namespaces
) {
12025 if (!perfmon_capable())
12030 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
12033 if (attr
.sample_period
& (1ULL << 63))
12037 /* Only privileged users can get physical addresses */
12038 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
)) {
12039 err
= perf_allow_kernel(&attr
);
12044 /* REGS_INTR can leak data, lockdown must prevent this */
12045 if (attr
.sample_type
& PERF_SAMPLE_REGS_INTR
) {
12046 err
= security_locked_down(LOCKDOWN_PERF
);
12052 * In cgroup mode, the pid argument is used to pass the fd
12053 * opened to the cgroup directory in cgroupfs. The cpu argument
12054 * designates the cpu on which to monitor threads from that
12057 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
12060 if (flags
& PERF_FLAG_FD_CLOEXEC
)
12061 f_flags
|= O_CLOEXEC
;
12063 event_fd
= get_unused_fd_flags(f_flags
);
12067 if (group_fd
!= -1) {
12068 err
= perf_fget_light(group_fd
, &group
);
12071 group_leader
= group
.file
->private_data
;
12072 if (flags
& PERF_FLAG_FD_OUTPUT
)
12073 output_event
= group_leader
;
12074 if (flags
& PERF_FLAG_FD_NO_GROUP
)
12075 group_leader
= NULL
;
12078 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
12079 task
= find_lively_task_by_vpid(pid
);
12080 if (IS_ERR(task
)) {
12081 err
= PTR_ERR(task
);
12086 if (task
&& group_leader
&&
12087 group_leader
->attr
.inherit
!= attr
.inherit
) {
12092 if (flags
& PERF_FLAG_PID_CGROUP
)
12095 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
12096 NULL
, NULL
, cgroup_fd
);
12097 if (IS_ERR(event
)) {
12098 err
= PTR_ERR(event
);
12102 if (is_sampling_event(event
)) {
12103 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
12110 * Special case software events and allow them to be part of
12111 * any hardware group.
12115 if (attr
.use_clockid
) {
12116 err
= perf_event_set_clock(event
, attr
.clockid
);
12121 if (pmu
->task_ctx_nr
== perf_sw_context
)
12122 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
12124 if (group_leader
) {
12125 if (is_software_event(event
) &&
12126 !in_software_context(group_leader
)) {
12128 * If the event is a sw event, but the group_leader
12129 * is on hw context.
12131 * Allow the addition of software events to hw
12132 * groups, this is safe because software events
12133 * never fail to schedule.
12135 pmu
= group_leader
->ctx
->pmu
;
12136 } else if (!is_software_event(event
) &&
12137 is_software_event(group_leader
) &&
12138 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
12140 * In case the group is a pure software group, and we
12141 * try to add a hardware event, move the whole group to
12142 * the hardware context.
12149 * Get the target context (task or percpu):
12151 ctx
= find_get_context(pmu
, task
, event
);
12153 err
= PTR_ERR(ctx
);
12158 * Look up the group leader (we will attach this event to it):
12160 if (group_leader
) {
12164 * Do not allow a recursive hierarchy (this new sibling
12165 * becoming part of another group-sibling):
12167 if (group_leader
->group_leader
!= group_leader
)
12170 /* All events in a group should have the same clock */
12171 if (group_leader
->clock
!= event
->clock
)
12175 * Make sure we're both events for the same CPU;
12176 * grouping events for different CPUs is broken; since
12177 * you can never concurrently schedule them anyhow.
12179 if (group_leader
->cpu
!= event
->cpu
)
12183 * Make sure we're both on the same task, or both
12186 if (group_leader
->ctx
->task
!= ctx
->task
)
12190 * Do not allow to attach to a group in a different task
12191 * or CPU context. If we're moving SW events, we'll fix
12192 * this up later, so allow that.
12194 if (!move_group
&& group_leader
->ctx
!= ctx
)
12198 * Only a group leader can be exclusive or pinned
12200 if (attr
.exclusive
|| attr
.pinned
)
12204 if (output_event
) {
12205 err
= perf_event_set_output(event
, output_event
);
12210 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
12212 if (IS_ERR(event_file
)) {
12213 err
= PTR_ERR(event_file
);
12219 err
= down_read_interruptible(&task
->signal
->exec_update_lock
);
12224 * We must hold exec_update_lock across this and any potential
12225 * perf_install_in_context() call for this new event to
12226 * serialize against exec() altering our credentials (and the
12227 * perf_event_exit_task() that could imply).
12230 if (!perf_check_permission(&attr
, task
))
12235 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
12237 if (gctx
->task
== TASK_TOMBSTONE
) {
12243 * Check if we raced against another sys_perf_event_open() call
12244 * moving the software group underneath us.
12246 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
12248 * If someone moved the group out from under us, check
12249 * if this new event wound up on the same ctx, if so
12250 * its the regular !move_group case, otherwise fail.
12256 perf_event_ctx_unlock(group_leader
, gctx
);
12262 * Failure to create exclusive events returns -EBUSY.
12265 if (!exclusive_event_installable(group_leader
, ctx
))
12268 for_each_sibling_event(sibling
, group_leader
) {
12269 if (!exclusive_event_installable(sibling
, ctx
))
12273 mutex_lock(&ctx
->mutex
);
12276 if (ctx
->task
== TASK_TOMBSTONE
) {
12281 if (!perf_event_validate_size(event
)) {
12288 * Check if the @cpu we're creating an event for is online.
12290 * We use the perf_cpu_context::ctx::mutex to serialize against
12291 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
12293 struct perf_cpu_context
*cpuctx
=
12294 container_of(ctx
, struct perf_cpu_context
, ctx
);
12296 if (!cpuctx
->online
) {
12302 if (perf_need_aux_event(event
) && !perf_get_aux_event(event
, group_leader
)) {
12308 * Must be under the same ctx::mutex as perf_install_in_context(),
12309 * because we need to serialize with concurrent event creation.
12311 if (!exclusive_event_installable(event
, ctx
)) {
12316 WARN_ON_ONCE(ctx
->parent_ctx
);
12319 * This is the point on no return; we cannot fail hereafter. This is
12320 * where we start modifying current state.
12325 * See perf_event_ctx_lock() for comments on the details
12326 * of swizzling perf_event::ctx.
12328 perf_remove_from_context(group_leader
, 0);
12331 for_each_sibling_event(sibling
, group_leader
) {
12332 perf_remove_from_context(sibling
, 0);
12337 * Wait for everybody to stop referencing the events through
12338 * the old lists, before installing it on new lists.
12343 * Install the group siblings before the group leader.
12345 * Because a group leader will try and install the entire group
12346 * (through the sibling list, which is still in-tact), we can
12347 * end up with siblings installed in the wrong context.
12349 * By installing siblings first we NO-OP because they're not
12350 * reachable through the group lists.
12352 for_each_sibling_event(sibling
, group_leader
) {
12353 perf_event__state_init(sibling
);
12354 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
12359 * Removing from the context ends up with disabled
12360 * event. What we want here is event in the initial
12361 * startup state, ready to be add into new context.
12363 perf_event__state_init(group_leader
);
12364 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
12369 * Precalculate sample_data sizes; do while holding ctx::mutex such
12370 * that we're serialized against further additions and before
12371 * perf_install_in_context() which is the point the event is active and
12372 * can use these values.
12374 perf_event__header_size(event
);
12375 perf_event__id_header_size(event
);
12377 event
->owner
= current
;
12379 perf_install_in_context(ctx
, event
, event
->cpu
);
12380 perf_unpin_context(ctx
);
12383 perf_event_ctx_unlock(group_leader
, gctx
);
12384 mutex_unlock(&ctx
->mutex
);
12387 up_read(&task
->signal
->exec_update_lock
);
12388 put_task_struct(task
);
12391 mutex_lock(¤t
->perf_event_mutex
);
12392 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
12393 mutex_unlock(¤t
->perf_event_mutex
);
12396 * Drop the reference on the group_event after placing the
12397 * new event on the sibling_list. This ensures destruction
12398 * of the group leader will find the pointer to itself in
12399 * perf_group_detach().
12402 fd_install(event_fd
, event_file
);
12407 perf_event_ctx_unlock(group_leader
, gctx
);
12408 mutex_unlock(&ctx
->mutex
);
12411 up_read(&task
->signal
->exec_update_lock
);
12415 perf_unpin_context(ctx
);
12419 * If event_file is set, the fput() above will have called ->release()
12420 * and that will take care of freeing the event.
12426 put_task_struct(task
);
12430 put_unused_fd(event_fd
);
12435 * perf_event_create_kernel_counter
12437 * @attr: attributes of the counter to create
12438 * @cpu: cpu in which the counter is bound
12439 * @task: task to profile (NULL for percpu)
12440 * @overflow_handler: callback to trigger when we hit the event
12441 * @context: context data could be used in overflow_handler callback
12443 struct perf_event
*
12444 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
12445 struct task_struct
*task
,
12446 perf_overflow_handler_t overflow_handler
,
12449 struct perf_event_context
*ctx
;
12450 struct perf_event
*event
;
12454 * Grouping is not supported for kernel events, neither is 'AUX',
12455 * make sure the caller's intentions are adjusted.
12457 if (attr
->aux_output
)
12458 return ERR_PTR(-EINVAL
);
12460 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
12461 overflow_handler
, context
, -1);
12462 if (IS_ERR(event
)) {
12463 err
= PTR_ERR(event
);
12467 /* Mark owner so we could distinguish it from user events. */
12468 event
->owner
= TASK_TOMBSTONE
;
12471 * Get the target context (task or percpu):
12473 ctx
= find_get_context(event
->pmu
, task
, event
);
12475 err
= PTR_ERR(ctx
);
12479 WARN_ON_ONCE(ctx
->parent_ctx
);
12480 mutex_lock(&ctx
->mutex
);
12481 if (ctx
->task
== TASK_TOMBSTONE
) {
12488 * Check if the @cpu we're creating an event for is online.
12490 * We use the perf_cpu_context::ctx::mutex to serialize against
12491 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
12493 struct perf_cpu_context
*cpuctx
=
12494 container_of(ctx
, struct perf_cpu_context
, ctx
);
12495 if (!cpuctx
->online
) {
12501 if (!exclusive_event_installable(event
, ctx
)) {
12506 perf_install_in_context(ctx
, event
, event
->cpu
);
12507 perf_unpin_context(ctx
);
12508 mutex_unlock(&ctx
->mutex
);
12513 mutex_unlock(&ctx
->mutex
);
12514 perf_unpin_context(ctx
);
12519 return ERR_PTR(err
);
12521 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
12523 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
12525 struct perf_event_context
*src_ctx
;
12526 struct perf_event_context
*dst_ctx
;
12527 struct perf_event
*event
, *tmp
;
12530 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
12531 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
12534 * See perf_event_ctx_lock() for comments on the details
12535 * of swizzling perf_event::ctx.
12537 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
12538 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
12540 perf_remove_from_context(event
, 0);
12541 unaccount_event_cpu(event
, src_cpu
);
12543 list_add(&event
->migrate_entry
, &events
);
12547 * Wait for the events to quiesce before re-instating them.
12552 * Re-instate events in 2 passes.
12554 * Skip over group leaders and only install siblings on this first
12555 * pass, siblings will not get enabled without a leader, however a
12556 * leader will enable its siblings, even if those are still on the old
12559 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
12560 if (event
->group_leader
== event
)
12563 list_del(&event
->migrate_entry
);
12564 if (event
->state
>= PERF_EVENT_STATE_OFF
)
12565 event
->state
= PERF_EVENT_STATE_INACTIVE
;
12566 account_event_cpu(event
, dst_cpu
);
12567 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
12572 * Once all the siblings are setup properly, install the group leaders
12575 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
12576 list_del(&event
->migrate_entry
);
12577 if (event
->state
>= PERF_EVENT_STATE_OFF
)
12578 event
->state
= PERF_EVENT_STATE_INACTIVE
;
12579 account_event_cpu(event
, dst_cpu
);
12580 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
12583 mutex_unlock(&dst_ctx
->mutex
);
12584 mutex_unlock(&src_ctx
->mutex
);
12586 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
12588 static void sync_child_event(struct perf_event
*child_event
)
12590 struct perf_event
*parent_event
= child_event
->parent
;
12593 if (child_event
->attr
.inherit_stat
) {
12594 struct task_struct
*task
= child_event
->ctx
->task
;
12596 if (task
&& task
!= TASK_TOMBSTONE
)
12597 perf_event_read_event(child_event
, task
);
12600 child_val
= perf_event_count(child_event
);
12603 * Add back the child's count to the parent's count:
12605 atomic64_add(child_val
, &parent_event
->child_count
);
12606 atomic64_add(child_event
->total_time_enabled
,
12607 &parent_event
->child_total_time_enabled
);
12608 atomic64_add(child_event
->total_time_running
,
12609 &parent_event
->child_total_time_running
);
12613 perf_event_exit_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
12615 struct perf_event
*parent_event
= event
->parent
;
12616 unsigned long detach_flags
= 0;
12618 if (parent_event
) {
12620 * Do not destroy the 'original' grouping; because of the
12621 * context switch optimization the original events could've
12622 * ended up in a random child task.
12624 * If we were to destroy the original group, all group related
12625 * operations would cease to function properly after this
12626 * random child dies.
12628 * Do destroy all inherited groups, we don't care about those
12629 * and being thorough is better.
12631 detach_flags
= DETACH_GROUP
| DETACH_CHILD
;
12632 mutex_lock(&parent_event
->child_mutex
);
12635 perf_remove_from_context(event
, detach_flags
);
12637 raw_spin_lock_irq(&ctx
->lock
);
12638 if (event
->state
> PERF_EVENT_STATE_EXIT
)
12639 perf_event_set_state(event
, PERF_EVENT_STATE_EXIT
);
12640 raw_spin_unlock_irq(&ctx
->lock
);
12643 * Child events can be freed.
12645 if (parent_event
) {
12646 mutex_unlock(&parent_event
->child_mutex
);
12648 * Kick perf_poll() for is_event_hup();
12650 perf_event_wakeup(parent_event
);
12652 put_event(parent_event
);
12657 * Parent events are governed by their filedesc, retain them.
12659 perf_event_wakeup(event
);
12662 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
12664 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
12665 struct perf_event
*child_event
, *next
;
12667 WARN_ON_ONCE(child
!= current
);
12669 child_ctx
= perf_pin_task_context(child
, ctxn
);
12674 * In order to reduce the amount of tricky in ctx tear-down, we hold
12675 * ctx::mutex over the entire thing. This serializes against almost
12676 * everything that wants to access the ctx.
12678 * The exception is sys_perf_event_open() /
12679 * perf_event_create_kernel_count() which does find_get_context()
12680 * without ctx::mutex (it cannot because of the move_group double mutex
12681 * lock thing). See the comments in perf_install_in_context().
12683 mutex_lock(&child_ctx
->mutex
);
12686 * In a single ctx::lock section, de-schedule the events and detach the
12687 * context from the task such that we cannot ever get it scheduled back
12690 raw_spin_lock_irq(&child_ctx
->lock
);
12691 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
12694 * Now that the context is inactive, destroy the task <-> ctx relation
12695 * and mark the context dead.
12697 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
12698 put_ctx(child_ctx
); /* cannot be last */
12699 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
12700 put_task_struct(current
); /* cannot be last */
12702 clone_ctx
= unclone_ctx(child_ctx
);
12703 raw_spin_unlock_irq(&child_ctx
->lock
);
12706 put_ctx(clone_ctx
);
12709 * Report the task dead after unscheduling the events so that we
12710 * won't get any samples after PERF_RECORD_EXIT. We can however still
12711 * get a few PERF_RECORD_READ events.
12713 perf_event_task(child
, child_ctx
, 0);
12715 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
12716 perf_event_exit_event(child_event
, child_ctx
);
12718 mutex_unlock(&child_ctx
->mutex
);
12720 put_ctx(child_ctx
);
12724 * When a child task exits, feed back event values to parent events.
12726 * Can be called with exec_update_lock held when called from
12727 * setup_new_exec().
12729 void perf_event_exit_task(struct task_struct
*child
)
12731 struct perf_event
*event
, *tmp
;
12734 mutex_lock(&child
->perf_event_mutex
);
12735 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
12737 list_del_init(&event
->owner_entry
);
12740 * Ensure the list deletion is visible before we clear
12741 * the owner, closes a race against perf_release() where
12742 * we need to serialize on the owner->perf_event_mutex.
12744 smp_store_release(&event
->owner
, NULL
);
12746 mutex_unlock(&child
->perf_event_mutex
);
12748 for_each_task_context_nr(ctxn
)
12749 perf_event_exit_task_context(child
, ctxn
);
12752 * The perf_event_exit_task_context calls perf_event_task
12753 * with child's task_ctx, which generates EXIT events for
12754 * child contexts and sets child->perf_event_ctxp[] to NULL.
12755 * At this point we need to send EXIT events to cpu contexts.
12757 perf_event_task(child
, NULL
, 0);
12760 static void perf_free_event(struct perf_event
*event
,
12761 struct perf_event_context
*ctx
)
12763 struct perf_event
*parent
= event
->parent
;
12765 if (WARN_ON_ONCE(!parent
))
12768 mutex_lock(&parent
->child_mutex
);
12769 list_del_init(&event
->child_list
);
12770 mutex_unlock(&parent
->child_mutex
);
12774 raw_spin_lock_irq(&ctx
->lock
);
12775 perf_group_detach(event
);
12776 list_del_event(event
, ctx
);
12777 raw_spin_unlock_irq(&ctx
->lock
);
12782 * Free a context as created by inheritance by perf_event_init_task() below,
12783 * used by fork() in case of fail.
12785 * Even though the task has never lived, the context and events have been
12786 * exposed through the child_list, so we must take care tearing it all down.
12788 void perf_event_free_task(struct task_struct
*task
)
12790 struct perf_event_context
*ctx
;
12791 struct perf_event
*event
, *tmp
;
12794 for_each_task_context_nr(ctxn
) {
12795 ctx
= task
->perf_event_ctxp
[ctxn
];
12799 mutex_lock(&ctx
->mutex
);
12800 raw_spin_lock_irq(&ctx
->lock
);
12802 * Destroy the task <-> ctx relation and mark the context dead.
12804 * This is important because even though the task hasn't been
12805 * exposed yet the context has been (through child_list).
12807 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
12808 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
12809 put_task_struct(task
); /* cannot be last */
12810 raw_spin_unlock_irq(&ctx
->lock
);
12812 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
12813 perf_free_event(event
, ctx
);
12815 mutex_unlock(&ctx
->mutex
);
12818 * perf_event_release_kernel() could've stolen some of our
12819 * child events and still have them on its free_list. In that
12820 * case we must wait for these events to have been freed (in
12821 * particular all their references to this task must've been
12824 * Without this copy_process() will unconditionally free this
12825 * task (irrespective of its reference count) and
12826 * _free_event()'s put_task_struct(event->hw.target) will be a
12829 * Wait for all events to drop their context reference.
12831 wait_var_event(&ctx
->refcount
, refcount_read(&ctx
->refcount
) == 1);
12832 put_ctx(ctx
); /* must be last */
12836 void perf_event_delayed_put(struct task_struct
*task
)
12840 for_each_task_context_nr(ctxn
)
12841 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
12844 struct file
*perf_event_get(unsigned int fd
)
12846 struct file
*file
= fget(fd
);
12848 return ERR_PTR(-EBADF
);
12850 if (file
->f_op
!= &perf_fops
) {
12852 return ERR_PTR(-EBADF
);
12858 const struct perf_event
*perf_get_event(struct file
*file
)
12860 if (file
->f_op
!= &perf_fops
)
12861 return ERR_PTR(-EINVAL
);
12863 return file
->private_data
;
12866 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
12869 return ERR_PTR(-EINVAL
);
12871 return &event
->attr
;
12875 * Inherit an event from parent task to child task.
12878 * - valid pointer on success
12879 * - NULL for orphaned events
12880 * - IS_ERR() on error
12882 static struct perf_event
*
12883 inherit_event(struct perf_event
*parent_event
,
12884 struct task_struct
*parent
,
12885 struct perf_event_context
*parent_ctx
,
12886 struct task_struct
*child
,
12887 struct perf_event
*group_leader
,
12888 struct perf_event_context
*child_ctx
)
12890 enum perf_event_state parent_state
= parent_event
->state
;
12891 struct perf_event
*child_event
;
12892 unsigned long flags
;
12895 * Instead of creating recursive hierarchies of events,
12896 * we link inherited events back to the original parent,
12897 * which has a filp for sure, which we use as the reference
12900 if (parent_event
->parent
)
12901 parent_event
= parent_event
->parent
;
12903 child_event
= perf_event_alloc(&parent_event
->attr
,
12906 group_leader
, parent_event
,
12908 if (IS_ERR(child_event
))
12909 return child_event
;
12912 if ((child_event
->attach_state
& PERF_ATTACH_TASK_DATA
) &&
12913 !child_ctx
->task_ctx_data
) {
12914 struct pmu
*pmu
= child_event
->pmu
;
12916 child_ctx
->task_ctx_data
= alloc_task_ctx_data(pmu
);
12917 if (!child_ctx
->task_ctx_data
) {
12918 free_event(child_event
);
12919 return ERR_PTR(-ENOMEM
);
12924 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
12925 * must be under the same lock in order to serialize against
12926 * perf_event_release_kernel(), such that either we must observe
12927 * is_orphaned_event() or they will observe us on the child_list.
12929 mutex_lock(&parent_event
->child_mutex
);
12930 if (is_orphaned_event(parent_event
) ||
12931 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
12932 mutex_unlock(&parent_event
->child_mutex
);
12933 /* task_ctx_data is freed with child_ctx */
12934 free_event(child_event
);
12938 get_ctx(child_ctx
);
12941 * Make the child state follow the state of the parent event,
12942 * not its attr.disabled bit. We hold the parent's mutex,
12943 * so we won't race with perf_event_{en, dis}able_family.
12945 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
12946 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
12948 child_event
->state
= PERF_EVENT_STATE_OFF
;
12950 if (parent_event
->attr
.freq
) {
12951 u64 sample_period
= parent_event
->hw
.sample_period
;
12952 struct hw_perf_event
*hwc
= &child_event
->hw
;
12954 hwc
->sample_period
= sample_period
;
12955 hwc
->last_period
= sample_period
;
12957 local64_set(&hwc
->period_left
, sample_period
);
12960 child_event
->ctx
= child_ctx
;
12961 child_event
->overflow_handler
= parent_event
->overflow_handler
;
12962 child_event
->overflow_handler_context
12963 = parent_event
->overflow_handler_context
;
12966 * Precalculate sample_data sizes
12968 perf_event__header_size(child_event
);
12969 perf_event__id_header_size(child_event
);
12972 * Link it up in the child's context:
12974 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
12975 add_event_to_ctx(child_event
, child_ctx
);
12976 child_event
->attach_state
|= PERF_ATTACH_CHILD
;
12977 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
12980 * Link this into the parent event's child list
12982 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
12983 mutex_unlock(&parent_event
->child_mutex
);
12985 return child_event
;
12989 * Inherits an event group.
12991 * This will quietly suppress orphaned events; !inherit_event() is not an error.
12992 * This matches with perf_event_release_kernel() removing all child events.
12998 static int inherit_group(struct perf_event
*parent_event
,
12999 struct task_struct
*parent
,
13000 struct perf_event_context
*parent_ctx
,
13001 struct task_struct
*child
,
13002 struct perf_event_context
*child_ctx
)
13004 struct perf_event
*leader
;
13005 struct perf_event
*sub
;
13006 struct perf_event
*child_ctr
;
13008 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
13009 child
, NULL
, child_ctx
);
13010 if (IS_ERR(leader
))
13011 return PTR_ERR(leader
);
13013 * @leader can be NULL here because of is_orphaned_event(). In this
13014 * case inherit_event() will create individual events, similar to what
13015 * perf_group_detach() would do anyway.
13017 for_each_sibling_event(sub
, parent_event
) {
13018 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
13019 child
, leader
, child_ctx
);
13020 if (IS_ERR(child_ctr
))
13021 return PTR_ERR(child_ctr
);
13023 if (sub
->aux_event
== parent_event
&& child_ctr
&&
13024 !perf_get_aux_event(child_ctr
, leader
))
13031 * Creates the child task context and tries to inherit the event-group.
13033 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
13034 * inherited_all set when we 'fail' to inherit an orphaned event; this is
13035 * consistent with perf_event_release_kernel() removing all child events.
13042 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
13043 struct perf_event_context
*parent_ctx
,
13044 struct task_struct
*child
, int ctxn
,
13045 u64 clone_flags
, int *inherited_all
)
13048 struct perf_event_context
*child_ctx
;
13050 if (!event
->attr
.inherit
||
13051 (event
->attr
.inherit_thread
&& !(clone_flags
& CLONE_THREAD
)) ||
13052 /* Do not inherit if sigtrap and signal handlers were cleared. */
13053 (event
->attr
.sigtrap
&& (clone_flags
& CLONE_CLEAR_SIGHAND
))) {
13054 *inherited_all
= 0;
13058 child_ctx
= child
->perf_event_ctxp
[ctxn
];
13061 * This is executed from the parent task context, so
13062 * inherit events that have been marked for cloning.
13063 * First allocate and initialize a context for the
13066 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
13070 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
13073 ret
= inherit_group(event
, parent
, parent_ctx
,
13077 *inherited_all
= 0;
13083 * Initialize the perf_event context in task_struct
13085 static int perf_event_init_context(struct task_struct
*child
, int ctxn
,
13088 struct perf_event_context
*child_ctx
, *parent_ctx
;
13089 struct perf_event_context
*cloned_ctx
;
13090 struct perf_event
*event
;
13091 struct task_struct
*parent
= current
;
13092 int inherited_all
= 1;
13093 unsigned long flags
;
13096 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
13100 * If the parent's context is a clone, pin it so it won't get
13101 * swapped under us.
13103 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
13108 * No need to check if parent_ctx != NULL here; since we saw
13109 * it non-NULL earlier, the only reason for it to become NULL
13110 * is if we exit, and since we're currently in the middle of
13111 * a fork we can't be exiting at the same time.
13115 * Lock the parent list. No need to lock the child - not PID
13116 * hashed yet and not running, so nobody can access it.
13118 mutex_lock(&parent_ctx
->mutex
);
13121 * We dont have to disable NMIs - we are only looking at
13122 * the list, not manipulating it:
13124 perf_event_groups_for_each(event
, &parent_ctx
->pinned_groups
) {
13125 ret
= inherit_task_group(event
, parent
, parent_ctx
,
13126 child
, ctxn
, clone_flags
,
13133 * We can't hold ctx->lock when iterating the ->flexible_group list due
13134 * to allocations, but we need to prevent rotation because
13135 * rotate_ctx() will change the list from interrupt context.
13137 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
13138 parent_ctx
->rotate_disable
= 1;
13139 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
13141 perf_event_groups_for_each(event
, &parent_ctx
->flexible_groups
) {
13142 ret
= inherit_task_group(event
, parent
, parent_ctx
,
13143 child
, ctxn
, clone_flags
,
13149 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
13150 parent_ctx
->rotate_disable
= 0;
13152 child_ctx
= child
->perf_event_ctxp
[ctxn
];
13154 if (child_ctx
&& inherited_all
) {
13156 * Mark the child context as a clone of the parent
13157 * context, or of whatever the parent is a clone of.
13159 * Note that if the parent is a clone, the holding of
13160 * parent_ctx->lock avoids it from being uncloned.
13162 cloned_ctx
= parent_ctx
->parent_ctx
;
13164 child_ctx
->parent_ctx
= cloned_ctx
;
13165 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
13167 child_ctx
->parent_ctx
= parent_ctx
;
13168 child_ctx
->parent_gen
= parent_ctx
->generation
;
13170 get_ctx(child_ctx
->parent_ctx
);
13173 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
13175 mutex_unlock(&parent_ctx
->mutex
);
13177 perf_unpin_context(parent_ctx
);
13178 put_ctx(parent_ctx
);
13184 * Initialize the perf_event context in task_struct
13186 int perf_event_init_task(struct task_struct
*child
, u64 clone_flags
)
13190 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
13191 mutex_init(&child
->perf_event_mutex
);
13192 INIT_LIST_HEAD(&child
->perf_event_list
);
13194 for_each_task_context_nr(ctxn
) {
13195 ret
= perf_event_init_context(child
, ctxn
, clone_flags
);
13197 perf_event_free_task(child
);
13205 static void __init
perf_event_init_all_cpus(void)
13207 struct swevent_htable
*swhash
;
13210 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
13212 for_each_possible_cpu(cpu
) {
13213 swhash
= &per_cpu(swevent_htable
, cpu
);
13214 mutex_init(&swhash
->hlist_mutex
);
13215 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
13217 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
13218 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
13220 #ifdef CONFIG_CGROUP_PERF
13221 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
13223 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
13227 static void perf_swevent_init_cpu(unsigned int cpu
)
13229 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
13231 mutex_lock(&swhash
->hlist_mutex
);
13232 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
13233 struct swevent_hlist
*hlist
;
13235 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
13237 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
13239 mutex_unlock(&swhash
->hlist_mutex
);
13242 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
13243 static void __perf_event_exit_context(void *__info
)
13245 struct perf_event_context
*ctx
= __info
;
13246 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
13247 struct perf_event
*event
;
13249 raw_spin_lock(&ctx
->lock
);
13250 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
13251 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
13252 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
13253 raw_spin_unlock(&ctx
->lock
);
13256 static void perf_event_exit_cpu_context(int cpu
)
13258 struct perf_cpu_context
*cpuctx
;
13259 struct perf_event_context
*ctx
;
13262 mutex_lock(&pmus_lock
);
13263 list_for_each_entry(pmu
, &pmus
, entry
) {
13264 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
13265 ctx
= &cpuctx
->ctx
;
13267 mutex_lock(&ctx
->mutex
);
13268 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
13269 cpuctx
->online
= 0;
13270 mutex_unlock(&ctx
->mutex
);
13272 cpumask_clear_cpu(cpu
, perf_online_mask
);
13273 mutex_unlock(&pmus_lock
);
13277 static void perf_event_exit_cpu_context(int cpu
) { }
13281 int perf_event_init_cpu(unsigned int cpu
)
13283 struct perf_cpu_context
*cpuctx
;
13284 struct perf_event_context
*ctx
;
13287 perf_swevent_init_cpu(cpu
);
13289 mutex_lock(&pmus_lock
);
13290 cpumask_set_cpu(cpu
, perf_online_mask
);
13291 list_for_each_entry(pmu
, &pmus
, entry
) {
13292 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
13293 ctx
= &cpuctx
->ctx
;
13295 mutex_lock(&ctx
->mutex
);
13296 cpuctx
->online
= 1;
13297 mutex_unlock(&ctx
->mutex
);
13299 mutex_unlock(&pmus_lock
);
13304 int perf_event_exit_cpu(unsigned int cpu
)
13306 perf_event_exit_cpu_context(cpu
);
13311 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
13315 for_each_online_cpu(cpu
)
13316 perf_event_exit_cpu(cpu
);
13322 * Run the perf reboot notifier at the very last possible moment so that
13323 * the generic watchdog code runs as long as possible.
13325 static struct notifier_block perf_reboot_notifier
= {
13326 .notifier_call
= perf_reboot
,
13327 .priority
= INT_MIN
,
13330 void __init
perf_event_init(void)
13334 idr_init(&pmu_idr
);
13336 perf_event_init_all_cpus();
13337 init_srcu_struct(&pmus_srcu
);
13338 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
13339 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
13340 perf_pmu_register(&perf_task_clock
, NULL
, -1);
13341 perf_tp_register();
13342 perf_event_init_cpu(smp_processor_id());
13343 register_reboot_notifier(&perf_reboot_notifier
);
13345 ret
= init_hw_breakpoint();
13346 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
13348 perf_event_cache
= KMEM_CACHE(perf_event
, SLAB_PANIC
);
13351 * Build time assertion that we keep the data_head at the intended
13352 * location. IOW, validation we got the __reserved[] size right.
13354 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
13358 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
13361 struct perf_pmu_events_attr
*pmu_attr
=
13362 container_of(attr
, struct perf_pmu_events_attr
, attr
);
13364 if (pmu_attr
->event_str
)
13365 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
13369 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
13371 static int __init
perf_event_sysfs_init(void)
13376 mutex_lock(&pmus_lock
);
13378 ret
= bus_register(&pmu_bus
);
13382 list_for_each_entry(pmu
, &pmus
, entry
) {
13383 if (!pmu
->name
|| pmu
->type
< 0)
13386 ret
= pmu_dev_alloc(pmu
);
13387 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
13389 pmu_bus_running
= 1;
13393 mutex_unlock(&pmus_lock
);
13397 device_initcall(perf_event_sysfs_init
);
13399 #ifdef CONFIG_CGROUP_PERF
13400 static struct cgroup_subsys_state
*
13401 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
13403 struct perf_cgroup
*jc
;
13405 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
13407 return ERR_PTR(-ENOMEM
);
13409 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
13412 return ERR_PTR(-ENOMEM
);
13418 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
13420 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
13422 free_percpu(jc
->info
);
13426 static int perf_cgroup_css_online(struct cgroup_subsys_state
*css
)
13428 perf_event_cgroup(css
->cgroup
);
13432 static int __perf_cgroup_move(void *info
)
13434 struct task_struct
*task
= info
;
13436 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
13441 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
13443 struct task_struct
*task
;
13444 struct cgroup_subsys_state
*css
;
13446 cgroup_taskset_for_each(task
, css
, tset
)
13447 task_function_call(task
, __perf_cgroup_move
, task
);
13450 struct cgroup_subsys perf_event_cgrp_subsys
= {
13451 .css_alloc
= perf_cgroup_css_alloc
,
13452 .css_free
= perf_cgroup_css_free
,
13453 .css_online
= perf_cgroup_css_online
,
13454 .attach
= perf_cgroup_attach
,
13456 * Implicitly enable on dfl hierarchy so that perf events can
13457 * always be filtered by cgroup2 path as long as perf_event
13458 * controller is not mounted on a legacy hierarchy.
13460 .implicit_on_dfl
= true,
13463 #endif /* CONFIG_CGROUP_PERF */