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>
57 #include <asm/irq_regs.h>
59 typedef int (*remote_function_f
)(void *);
61 struct remote_function_call
{
62 struct task_struct
*p
;
63 remote_function_f func
;
68 static void remote_function(void *data
)
70 struct remote_function_call
*tfc
= data
;
71 struct task_struct
*p
= tfc
->p
;
75 if (task_cpu(p
) != smp_processor_id())
79 * Now that we're on right CPU with IRQs disabled, we can test
80 * if we hit the right task without races.
83 tfc
->ret
= -ESRCH
; /* No such (running) process */
88 tfc
->ret
= tfc
->func(tfc
->info
);
92 * task_function_call - call a function on the cpu on which a task runs
93 * @p: the task to evaluate
94 * @func: the function to be called
95 * @info: the function call argument
97 * Calls the function @func when the task is currently running. This might
98 * be on the current CPU, which just calls the function directly
100 * returns: @func return value, or
101 * -ESRCH - when the process isn't running
102 * -EAGAIN - when the process moved away
105 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
107 struct remote_function_call data
= {
116 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
119 } while (ret
== -EAGAIN
);
125 * cpu_function_call - call a function on the cpu
126 * @func: the function to be called
127 * @info: the function call argument
129 * Calls the function @func on the remote cpu.
131 * returns: @func return value or -ENXIO when the cpu is offline
133 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
135 struct remote_function_call data
= {
139 .ret
= -ENXIO
, /* No such CPU */
142 smp_call_function_single(cpu
, remote_function
, &data
, 1);
147 static inline struct perf_cpu_context
*
148 __get_cpu_context(struct perf_event_context
*ctx
)
150 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
153 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
154 struct perf_event_context
*ctx
)
156 raw_spin_lock(&cpuctx
->ctx
.lock
);
158 raw_spin_lock(&ctx
->lock
);
161 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
162 struct perf_event_context
*ctx
)
165 raw_spin_unlock(&ctx
->lock
);
166 raw_spin_unlock(&cpuctx
->ctx
.lock
);
169 #define TASK_TOMBSTONE ((void *)-1L)
171 static bool is_kernel_event(struct perf_event
*event
)
173 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
177 * On task ctx scheduling...
179 * When !ctx->nr_events a task context will not be scheduled. This means
180 * we can disable the scheduler hooks (for performance) without leaving
181 * pending task ctx state.
183 * This however results in two special cases:
185 * - removing the last event from a task ctx; this is relatively straight
186 * forward and is done in __perf_remove_from_context.
188 * - adding the first event to a task ctx; this is tricky because we cannot
189 * rely on ctx->is_active and therefore cannot use event_function_call().
190 * See perf_install_in_context().
192 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
195 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
196 struct perf_event_context
*, void *);
198 struct event_function_struct
{
199 struct perf_event
*event
;
204 static int event_function(void *info
)
206 struct event_function_struct
*efs
= info
;
207 struct perf_event
*event
= efs
->event
;
208 struct perf_event_context
*ctx
= event
->ctx
;
209 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
210 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
213 lockdep_assert_irqs_disabled();
215 perf_ctx_lock(cpuctx
, task_ctx
);
217 * Since we do the IPI call without holding ctx->lock things can have
218 * changed, double check we hit the task we set out to hit.
221 if (ctx
->task
!= current
) {
227 * We only use event_function_call() on established contexts,
228 * and event_function() is only ever called when active (or
229 * rather, we'll have bailed in task_function_call() or the
230 * above ctx->task != current test), therefore we must have
231 * ctx->is_active here.
233 WARN_ON_ONCE(!ctx
->is_active
);
235 * And since we have ctx->is_active, cpuctx->task_ctx must
238 WARN_ON_ONCE(task_ctx
!= ctx
);
240 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
243 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
245 perf_ctx_unlock(cpuctx
, task_ctx
);
250 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
252 struct perf_event_context
*ctx
= event
->ctx
;
253 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
254 struct event_function_struct efs
= {
260 if (!event
->parent
) {
262 * If this is a !child event, we must hold ctx::mutex to
263 * stabilize the the event->ctx relation. See
264 * perf_event_ctx_lock().
266 lockdep_assert_held(&ctx
->mutex
);
270 cpu_function_call(event
->cpu
, event_function
, &efs
);
274 if (task
== TASK_TOMBSTONE
)
278 if (!task_function_call(task
, event_function
, &efs
))
281 raw_spin_lock_irq(&ctx
->lock
);
283 * Reload the task pointer, it might have been changed by
284 * a concurrent perf_event_context_sched_out().
287 if (task
== TASK_TOMBSTONE
) {
288 raw_spin_unlock_irq(&ctx
->lock
);
291 if (ctx
->is_active
) {
292 raw_spin_unlock_irq(&ctx
->lock
);
295 func(event
, NULL
, ctx
, data
);
296 raw_spin_unlock_irq(&ctx
->lock
);
300 * Similar to event_function_call() + event_function(), but hard assumes IRQs
301 * are already disabled and we're on the right CPU.
303 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
305 struct perf_event_context
*ctx
= event
->ctx
;
306 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
307 struct task_struct
*task
= READ_ONCE(ctx
->task
);
308 struct perf_event_context
*task_ctx
= NULL
;
310 lockdep_assert_irqs_disabled();
313 if (task
== TASK_TOMBSTONE
)
319 perf_ctx_lock(cpuctx
, task_ctx
);
322 if (task
== TASK_TOMBSTONE
)
327 * We must be either inactive or active and the right task,
328 * otherwise we're screwed, since we cannot IPI to somewhere
331 if (ctx
->is_active
) {
332 if (WARN_ON_ONCE(task
!= current
))
335 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
339 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
342 func(event
, cpuctx
, ctx
, data
);
344 perf_ctx_unlock(cpuctx
, task_ctx
);
347 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
348 PERF_FLAG_FD_OUTPUT |\
349 PERF_FLAG_PID_CGROUP |\
350 PERF_FLAG_FD_CLOEXEC)
353 * branch priv levels that need permission checks
355 #define PERF_SAMPLE_BRANCH_PERM_PLM \
356 (PERF_SAMPLE_BRANCH_KERNEL |\
357 PERF_SAMPLE_BRANCH_HV)
360 EVENT_FLEXIBLE
= 0x1,
363 /* see ctx_resched() for details */
365 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
369 * perf_sched_events : >0 events exist
370 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
373 static void perf_sched_delayed(struct work_struct
*work
);
374 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
375 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
376 static DEFINE_MUTEX(perf_sched_mutex
);
377 static atomic_t perf_sched_count
;
379 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
380 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
381 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
383 static atomic_t nr_mmap_events __read_mostly
;
384 static atomic_t nr_comm_events __read_mostly
;
385 static atomic_t nr_namespaces_events __read_mostly
;
386 static atomic_t nr_task_events __read_mostly
;
387 static atomic_t nr_freq_events __read_mostly
;
388 static atomic_t nr_switch_events __read_mostly
;
389 static atomic_t nr_ksymbol_events __read_mostly
;
390 static atomic_t nr_bpf_events __read_mostly
;
391 static atomic_t nr_cgroup_events __read_mostly
;
393 static LIST_HEAD(pmus
);
394 static DEFINE_MUTEX(pmus_lock
);
395 static struct srcu_struct pmus_srcu
;
396 static cpumask_var_t perf_online_mask
;
399 * perf event paranoia level:
400 * -1 - not paranoid at all
401 * 0 - disallow raw tracepoint access for unpriv
402 * 1 - disallow cpu events for unpriv
403 * 2 - disallow kernel profiling for unpriv
405 int sysctl_perf_event_paranoid __read_mostly
= 2;
407 /* Minimum for 512 kiB + 1 user control page */
408 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
411 * max perf event sample rate
413 #define DEFAULT_MAX_SAMPLE_RATE 100000
414 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
415 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
417 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
419 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
420 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
422 static int perf_sample_allowed_ns __read_mostly
=
423 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
425 static void update_perf_cpu_limits(void)
427 u64 tmp
= perf_sample_period_ns
;
429 tmp
*= sysctl_perf_cpu_time_max_percent
;
430 tmp
= div_u64(tmp
, 100);
434 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
437 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
);
439 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
440 void __user
*buffer
, size_t *lenp
,
444 int perf_cpu
= sysctl_perf_cpu_time_max_percent
;
446 * If throttling is disabled don't allow the write:
448 if (write
&& (perf_cpu
== 100 || perf_cpu
== 0))
451 ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
455 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
456 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
457 update_perf_cpu_limits();
462 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
464 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
465 void __user
*buffer
, size_t *lenp
,
468 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
473 if (sysctl_perf_cpu_time_max_percent
== 100 ||
474 sysctl_perf_cpu_time_max_percent
== 0) {
476 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
477 WRITE_ONCE(perf_sample_allowed_ns
, 0);
479 update_perf_cpu_limits();
486 * perf samples are done in some very critical code paths (NMIs).
487 * If they take too much CPU time, the system can lock up and not
488 * get any real work done. This will drop the sample rate when
489 * we detect that events are taking too long.
491 #define NR_ACCUMULATED_SAMPLES 128
492 static DEFINE_PER_CPU(u64
, running_sample_length
);
494 static u64 __report_avg
;
495 static u64 __report_allowed
;
497 static void perf_duration_warn(struct irq_work
*w
)
499 printk_ratelimited(KERN_INFO
500 "perf: interrupt took too long (%lld > %lld), lowering "
501 "kernel.perf_event_max_sample_rate to %d\n",
502 __report_avg
, __report_allowed
,
503 sysctl_perf_event_sample_rate
);
506 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
508 void perf_sample_event_took(u64 sample_len_ns
)
510 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
518 /* Decay the counter by 1 average sample. */
519 running_len
= __this_cpu_read(running_sample_length
);
520 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
521 running_len
+= sample_len_ns
;
522 __this_cpu_write(running_sample_length
, running_len
);
525 * Note: this will be biased artifically low until we have
526 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
527 * from having to maintain a count.
529 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
530 if (avg_len
<= max_len
)
533 __report_avg
= avg_len
;
534 __report_allowed
= max_len
;
537 * Compute a throttle threshold 25% below the current duration.
539 avg_len
+= avg_len
/ 4;
540 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
546 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
547 WRITE_ONCE(max_samples_per_tick
, max
);
549 sysctl_perf_event_sample_rate
= max
* HZ
;
550 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
552 if (!irq_work_queue(&perf_duration_work
)) {
553 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
554 "kernel.perf_event_max_sample_rate to %d\n",
555 __report_avg
, __report_allowed
,
556 sysctl_perf_event_sample_rate
);
560 static atomic64_t perf_event_id
;
562 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
563 enum event_type_t event_type
);
565 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
566 enum event_type_t event_type
,
567 struct task_struct
*task
);
569 static void update_context_time(struct perf_event_context
*ctx
);
570 static u64
perf_event_time(struct perf_event
*event
);
572 void __weak
perf_event_print_debug(void) { }
574 extern __weak
const char *perf_pmu_name(void)
579 static inline u64
perf_clock(void)
581 return local_clock();
584 static inline u64
perf_event_clock(struct perf_event
*event
)
586 return event
->clock();
590 * State based event timekeeping...
592 * The basic idea is to use event->state to determine which (if any) time
593 * fields to increment with the current delta. This means we only need to
594 * update timestamps when we change state or when they are explicitly requested
597 * Event groups make things a little more complicated, but not terribly so. The
598 * rules for a group are that if the group leader is OFF the entire group is
599 * OFF, irrespecive of what the group member states are. This results in
600 * __perf_effective_state().
602 * A futher ramification is that when a group leader flips between OFF and
603 * !OFF, we need to update all group member times.
606 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
607 * need to make sure the relevant context time is updated before we try and
608 * update our timestamps.
611 static __always_inline
enum perf_event_state
612 __perf_effective_state(struct perf_event
*event
)
614 struct perf_event
*leader
= event
->group_leader
;
616 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
617 return leader
->state
;
622 static __always_inline
void
623 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
625 enum perf_event_state state
= __perf_effective_state(event
);
626 u64 delta
= now
- event
->tstamp
;
628 *enabled
= event
->total_time_enabled
;
629 if (state
>= PERF_EVENT_STATE_INACTIVE
)
632 *running
= event
->total_time_running
;
633 if (state
>= PERF_EVENT_STATE_ACTIVE
)
637 static void perf_event_update_time(struct perf_event
*event
)
639 u64 now
= perf_event_time(event
);
641 __perf_update_times(event
, now
, &event
->total_time_enabled
,
642 &event
->total_time_running
);
646 static void perf_event_update_sibling_time(struct perf_event
*leader
)
648 struct perf_event
*sibling
;
650 for_each_sibling_event(sibling
, leader
)
651 perf_event_update_time(sibling
);
655 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
657 if (event
->state
== state
)
660 perf_event_update_time(event
);
662 * If a group leader gets enabled/disabled all its siblings
665 if ((event
->state
< 0) ^ (state
< 0))
666 perf_event_update_sibling_time(event
);
668 WRITE_ONCE(event
->state
, state
);
671 #ifdef CONFIG_CGROUP_PERF
674 perf_cgroup_match(struct perf_event
*event
)
676 struct perf_event_context
*ctx
= event
->ctx
;
677 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
679 /* @event doesn't care about cgroup */
683 /* wants specific cgroup scope but @cpuctx isn't associated with any */
688 * Cgroup scoping is recursive. An event enabled for a cgroup is
689 * also enabled for all its descendant cgroups. If @cpuctx's
690 * cgroup is a descendant of @event's (the test covers identity
691 * case), it's a match.
693 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
694 event
->cgrp
->css
.cgroup
);
697 static inline void perf_detach_cgroup(struct perf_event
*event
)
699 css_put(&event
->cgrp
->css
);
703 static inline int is_cgroup_event(struct perf_event
*event
)
705 return event
->cgrp
!= NULL
;
708 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
710 struct perf_cgroup_info
*t
;
712 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
716 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
718 struct perf_cgroup_info
*info
;
723 info
= this_cpu_ptr(cgrp
->info
);
725 info
->time
+= now
- info
->timestamp
;
726 info
->timestamp
= now
;
729 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
731 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
732 struct cgroup_subsys_state
*css
;
735 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
736 cgrp
= container_of(css
, struct perf_cgroup
, css
);
737 __update_cgrp_time(cgrp
);
742 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
744 struct perf_cgroup
*cgrp
;
747 * ensure we access cgroup data only when needed and
748 * when we know the cgroup is pinned (css_get)
750 if (!is_cgroup_event(event
))
753 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
755 * Do not update time when cgroup is not active
757 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
758 __update_cgrp_time(event
->cgrp
);
762 perf_cgroup_set_timestamp(struct task_struct
*task
,
763 struct perf_event_context
*ctx
)
765 struct perf_cgroup
*cgrp
;
766 struct perf_cgroup_info
*info
;
767 struct cgroup_subsys_state
*css
;
770 * ctx->lock held by caller
771 * ensure we do not access cgroup data
772 * unless we have the cgroup pinned (css_get)
774 if (!task
|| !ctx
->nr_cgroups
)
777 cgrp
= perf_cgroup_from_task(task
, ctx
);
779 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
780 cgrp
= container_of(css
, struct perf_cgroup
, css
);
781 info
= this_cpu_ptr(cgrp
->info
);
782 info
->timestamp
= ctx
->timestamp
;
786 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
788 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
789 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
792 * reschedule events based on the cgroup constraint of task.
794 * mode SWOUT : schedule out everything
795 * mode SWIN : schedule in based on cgroup for next
797 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
799 struct perf_cpu_context
*cpuctx
;
800 struct list_head
*list
;
804 * Disable interrupts and preemption to avoid this CPU's
805 * cgrp_cpuctx_entry to change under us.
807 local_irq_save(flags
);
809 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
810 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
811 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
813 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
814 perf_pmu_disable(cpuctx
->ctx
.pmu
);
816 if (mode
& PERF_CGROUP_SWOUT
) {
817 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
819 * must not be done before ctxswout due
820 * to event_filter_match() in event_sched_out()
825 if (mode
& PERF_CGROUP_SWIN
) {
826 WARN_ON_ONCE(cpuctx
->cgrp
);
828 * set cgrp before ctxsw in to allow
829 * event_filter_match() to not have to pass
831 * we pass the cpuctx->ctx to perf_cgroup_from_task()
832 * because cgorup events are only per-cpu
834 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
836 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
838 perf_pmu_enable(cpuctx
->ctx
.pmu
);
839 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
842 local_irq_restore(flags
);
845 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
846 struct task_struct
*next
)
848 struct perf_cgroup
*cgrp1
;
849 struct perf_cgroup
*cgrp2
= NULL
;
853 * we come here when we know perf_cgroup_events > 0
854 * we do not need to pass the ctx here because we know
855 * we are holding the rcu lock
857 cgrp1
= perf_cgroup_from_task(task
, NULL
);
858 cgrp2
= perf_cgroup_from_task(next
, NULL
);
861 * only schedule out current cgroup events if we know
862 * that we are switching to a different cgroup. Otherwise,
863 * do no touch the cgroup events.
866 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
871 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
872 struct task_struct
*task
)
874 struct perf_cgroup
*cgrp1
;
875 struct perf_cgroup
*cgrp2
= NULL
;
879 * we come here when we know perf_cgroup_events > 0
880 * we do not need to pass the ctx here because we know
881 * we are holding the rcu lock
883 cgrp1
= perf_cgroup_from_task(task
, NULL
);
884 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
887 * only need to schedule in cgroup events if we are changing
888 * cgroup during ctxsw. Cgroup events were not scheduled
889 * out of ctxsw out if that was not the case.
892 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
897 static int perf_cgroup_ensure_storage(struct perf_event
*event
,
898 struct cgroup_subsys_state
*css
)
900 struct perf_cpu_context
*cpuctx
;
901 struct perf_event
**storage
;
902 int cpu
, heap_size
, ret
= 0;
905 * Allow storage to have sufficent space for an iterator for each
906 * possibly nested cgroup plus an iterator for events with no cgroup.
908 for (heap_size
= 1; css
; css
= css
->parent
)
911 for_each_possible_cpu(cpu
) {
912 cpuctx
= per_cpu_ptr(event
->pmu
->pmu_cpu_context
, cpu
);
913 if (heap_size
<= cpuctx
->heap_size
)
916 storage
= kmalloc_node(heap_size
* sizeof(struct perf_event
*),
917 GFP_KERNEL
, cpu_to_node(cpu
));
923 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
924 if (cpuctx
->heap_size
< heap_size
) {
925 swap(cpuctx
->heap
, storage
);
926 if (storage
== cpuctx
->heap_default
)
928 cpuctx
->heap_size
= heap_size
;
930 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
938 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
939 struct perf_event_attr
*attr
,
940 struct perf_event
*group_leader
)
942 struct perf_cgroup
*cgrp
;
943 struct cgroup_subsys_state
*css
;
944 struct fd f
= fdget(fd
);
950 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
951 &perf_event_cgrp_subsys
);
957 ret
= perf_cgroup_ensure_storage(event
, css
);
961 cgrp
= container_of(css
, struct perf_cgroup
, css
);
965 * all events in a group must monitor
966 * the same cgroup because a task belongs
967 * to only one perf cgroup at a time
969 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
970 perf_detach_cgroup(event
);
979 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
981 struct perf_cgroup_info
*t
;
982 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
983 event
->shadow_ctx_time
= now
- t
->timestamp
;
987 perf_cgroup_event_enable(struct perf_event
*event
, struct perf_event_context
*ctx
)
989 struct perf_cpu_context
*cpuctx
;
991 if (!is_cgroup_event(event
))
995 * Because cgroup events are always per-cpu events,
996 * @ctx == &cpuctx->ctx.
998 cpuctx
= container_of(ctx
, struct perf_cpu_context
, ctx
);
1001 * Since setting cpuctx->cgrp is conditional on the current @cgrp
1002 * matching the event's cgroup, we must do this for every new event,
1003 * because if the first would mismatch, the second would not try again
1004 * and we would leave cpuctx->cgrp unset.
1006 if (ctx
->is_active
&& !cpuctx
->cgrp
) {
1007 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
1009 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
1010 cpuctx
->cgrp
= cgrp
;
1013 if (ctx
->nr_cgroups
++)
1016 list_add(&cpuctx
->cgrp_cpuctx_entry
,
1017 per_cpu_ptr(&cgrp_cpuctx_list
, event
->cpu
));
1021 perf_cgroup_event_disable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1023 struct perf_cpu_context
*cpuctx
;
1025 if (!is_cgroup_event(event
))
1029 * Because cgroup events are always per-cpu events,
1030 * @ctx == &cpuctx->ctx.
1032 cpuctx
= container_of(ctx
, struct perf_cpu_context
, ctx
);
1034 if (--ctx
->nr_cgroups
)
1037 if (ctx
->is_active
&& cpuctx
->cgrp
)
1038 cpuctx
->cgrp
= NULL
;
1040 list_del(&cpuctx
->cgrp_cpuctx_entry
);
1043 #else /* !CONFIG_CGROUP_PERF */
1046 perf_cgroup_match(struct perf_event
*event
)
1051 static inline void perf_detach_cgroup(struct perf_event
*event
)
1054 static inline int is_cgroup_event(struct perf_event
*event
)
1059 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1063 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1067 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1068 struct task_struct
*next
)
1072 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1073 struct task_struct
*task
)
1077 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1078 struct perf_event_attr
*attr
,
1079 struct perf_event
*group_leader
)
1085 perf_cgroup_set_timestamp(struct task_struct
*task
,
1086 struct perf_event_context
*ctx
)
1091 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1096 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1100 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1106 perf_cgroup_event_enable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1111 perf_cgroup_event_disable(struct perf_event
*event
, struct perf_event_context
*ctx
)
1117 * set default to be dependent on timer tick just
1118 * like original code
1120 #define PERF_CPU_HRTIMER (1000 / HZ)
1122 * function must be called with interrupts disabled
1124 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1126 struct perf_cpu_context
*cpuctx
;
1129 lockdep_assert_irqs_disabled();
1131 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1132 rotations
= perf_rotate_context(cpuctx
);
1134 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1136 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1138 cpuctx
->hrtimer_active
= 0;
1139 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1141 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1144 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1146 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1147 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1150 /* no multiplexing needed for SW PMU */
1151 if (pmu
->task_ctx_nr
== perf_sw_context
)
1155 * check default is sane, if not set then force to
1156 * default interval (1/tick)
1158 interval
= pmu
->hrtimer_interval_ms
;
1160 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1162 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1164 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1165 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED_HARD
);
1166 timer
->function
= perf_mux_hrtimer_handler
;
1169 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1171 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1172 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1173 unsigned long flags
;
1175 /* not for SW PMU */
1176 if (pmu
->task_ctx_nr
== perf_sw_context
)
1179 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1180 if (!cpuctx
->hrtimer_active
) {
1181 cpuctx
->hrtimer_active
= 1;
1182 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1183 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED_HARD
);
1185 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1190 void perf_pmu_disable(struct pmu
*pmu
)
1192 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1194 pmu
->pmu_disable(pmu
);
1197 void perf_pmu_enable(struct pmu
*pmu
)
1199 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1201 pmu
->pmu_enable(pmu
);
1204 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1207 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1208 * perf_event_task_tick() are fully serialized because they're strictly cpu
1209 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1210 * disabled, while perf_event_task_tick is called from IRQ context.
1212 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1214 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1216 lockdep_assert_irqs_disabled();
1218 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1220 list_add(&ctx
->active_ctx_list
, head
);
1223 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1225 lockdep_assert_irqs_disabled();
1227 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1229 list_del_init(&ctx
->active_ctx_list
);
1232 static void get_ctx(struct perf_event_context
*ctx
)
1234 refcount_inc(&ctx
->refcount
);
1237 static void free_ctx(struct rcu_head
*head
)
1239 struct perf_event_context
*ctx
;
1241 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1242 kfree(ctx
->task_ctx_data
);
1246 static void put_ctx(struct perf_event_context
*ctx
)
1248 if (refcount_dec_and_test(&ctx
->refcount
)) {
1249 if (ctx
->parent_ctx
)
1250 put_ctx(ctx
->parent_ctx
);
1251 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1252 put_task_struct(ctx
->task
);
1253 call_rcu(&ctx
->rcu_head
, free_ctx
);
1258 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1259 * perf_pmu_migrate_context() we need some magic.
1261 * Those places that change perf_event::ctx will hold both
1262 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1264 * Lock ordering is by mutex address. There are two other sites where
1265 * perf_event_context::mutex nests and those are:
1267 * - perf_event_exit_task_context() [ child , 0 ]
1268 * perf_event_exit_event()
1269 * put_event() [ parent, 1 ]
1271 * - perf_event_init_context() [ parent, 0 ]
1272 * inherit_task_group()
1275 * perf_event_alloc()
1277 * perf_try_init_event() [ child , 1 ]
1279 * While it appears there is an obvious deadlock here -- the parent and child
1280 * nesting levels are inverted between the two. This is in fact safe because
1281 * life-time rules separate them. That is an exiting task cannot fork, and a
1282 * spawning task cannot (yet) exit.
1284 * But remember that that these are parent<->child context relations, and
1285 * migration does not affect children, therefore these two orderings should not
1288 * The change in perf_event::ctx does not affect children (as claimed above)
1289 * because the sys_perf_event_open() case will install a new event and break
1290 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1291 * concerned with cpuctx and that doesn't have children.
1293 * The places that change perf_event::ctx will issue:
1295 * perf_remove_from_context();
1296 * synchronize_rcu();
1297 * perf_install_in_context();
1299 * to affect the change. The remove_from_context() + synchronize_rcu() should
1300 * quiesce the event, after which we can install it in the new location. This
1301 * means that only external vectors (perf_fops, prctl) can perturb the event
1302 * while in transit. Therefore all such accessors should also acquire
1303 * perf_event_context::mutex to serialize against this.
1305 * However; because event->ctx can change while we're waiting to acquire
1306 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1311 * task_struct::perf_event_mutex
1312 * perf_event_context::mutex
1313 * perf_event::child_mutex;
1314 * perf_event_context::lock
1315 * perf_event::mmap_mutex
1317 * perf_addr_filters_head::lock
1321 * cpuctx->mutex / perf_event_context::mutex
1323 static struct perf_event_context
*
1324 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1326 struct perf_event_context
*ctx
;
1330 ctx
= READ_ONCE(event
->ctx
);
1331 if (!refcount_inc_not_zero(&ctx
->refcount
)) {
1337 mutex_lock_nested(&ctx
->mutex
, nesting
);
1338 if (event
->ctx
!= ctx
) {
1339 mutex_unlock(&ctx
->mutex
);
1347 static inline struct perf_event_context
*
1348 perf_event_ctx_lock(struct perf_event
*event
)
1350 return perf_event_ctx_lock_nested(event
, 0);
1353 static void perf_event_ctx_unlock(struct perf_event
*event
,
1354 struct perf_event_context
*ctx
)
1356 mutex_unlock(&ctx
->mutex
);
1361 * This must be done under the ctx->lock, such as to serialize against
1362 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1363 * calling scheduler related locks and ctx->lock nests inside those.
1365 static __must_check
struct perf_event_context
*
1366 unclone_ctx(struct perf_event_context
*ctx
)
1368 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1370 lockdep_assert_held(&ctx
->lock
);
1373 ctx
->parent_ctx
= NULL
;
1379 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1384 * only top level events have the pid namespace they were created in
1387 event
= event
->parent
;
1389 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1390 /* avoid -1 if it is idle thread or runs in another ns */
1391 if (!nr
&& !pid_alive(p
))
1396 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1398 return perf_event_pid_type(event
, p
, PIDTYPE_TGID
);
1401 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1403 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1407 * If we inherit events we want to return the parent event id
1410 static u64
primary_event_id(struct perf_event
*event
)
1415 id
= event
->parent
->id
;
1421 * Get the perf_event_context for a task and lock it.
1423 * This has to cope with with the fact that until it is locked,
1424 * the context could get moved to another task.
1426 static struct perf_event_context
*
1427 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1429 struct perf_event_context
*ctx
;
1433 * One of the few rules of preemptible RCU is that one cannot do
1434 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1435 * part of the read side critical section was irqs-enabled -- see
1436 * rcu_read_unlock_special().
1438 * Since ctx->lock nests under rq->lock we must ensure the entire read
1439 * side critical section has interrupts disabled.
1441 local_irq_save(*flags
);
1443 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1446 * If this context is a clone of another, it might
1447 * get swapped for another underneath us by
1448 * perf_event_task_sched_out, though the
1449 * rcu_read_lock() protects us from any context
1450 * getting freed. Lock the context and check if it
1451 * got swapped before we could get the lock, and retry
1452 * if so. If we locked the right context, then it
1453 * can't get swapped on us any more.
1455 raw_spin_lock(&ctx
->lock
);
1456 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1457 raw_spin_unlock(&ctx
->lock
);
1459 local_irq_restore(*flags
);
1463 if (ctx
->task
== TASK_TOMBSTONE
||
1464 !refcount_inc_not_zero(&ctx
->refcount
)) {
1465 raw_spin_unlock(&ctx
->lock
);
1468 WARN_ON_ONCE(ctx
->task
!= task
);
1473 local_irq_restore(*flags
);
1478 * Get the context for a task and increment its pin_count so it
1479 * can't get swapped to another task. This also increments its
1480 * reference count so that the context can't get freed.
1482 static struct perf_event_context
*
1483 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1485 struct perf_event_context
*ctx
;
1486 unsigned long flags
;
1488 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1491 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1496 static void perf_unpin_context(struct perf_event_context
*ctx
)
1498 unsigned long flags
;
1500 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1502 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1506 * Update the record of the current time in a context.
1508 static void update_context_time(struct perf_event_context
*ctx
)
1510 u64 now
= perf_clock();
1512 ctx
->time
+= now
- ctx
->timestamp
;
1513 ctx
->timestamp
= now
;
1516 static u64
perf_event_time(struct perf_event
*event
)
1518 struct perf_event_context
*ctx
= event
->ctx
;
1520 if (is_cgroup_event(event
))
1521 return perf_cgroup_event_time(event
);
1523 return ctx
? ctx
->time
: 0;
1526 static enum event_type_t
get_event_type(struct perf_event
*event
)
1528 struct perf_event_context
*ctx
= event
->ctx
;
1529 enum event_type_t event_type
;
1531 lockdep_assert_held(&ctx
->lock
);
1534 * It's 'group type', really, because if our group leader is
1535 * pinned, so are we.
1537 if (event
->group_leader
!= event
)
1538 event
= event
->group_leader
;
1540 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1542 event_type
|= EVENT_CPU
;
1548 * Helper function to initialize event group nodes.
1550 static void init_event_group(struct perf_event
*event
)
1552 RB_CLEAR_NODE(&event
->group_node
);
1553 event
->group_index
= 0;
1557 * Extract pinned or flexible groups from the context
1558 * based on event attrs bits.
1560 static struct perf_event_groups
*
1561 get_event_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1563 if (event
->attr
.pinned
)
1564 return &ctx
->pinned_groups
;
1566 return &ctx
->flexible_groups
;
1570 * Helper function to initializes perf_event_group trees.
1572 static void perf_event_groups_init(struct perf_event_groups
*groups
)
1574 groups
->tree
= RB_ROOT
;
1579 * Compare function for event groups;
1581 * Implements complex key that first sorts by CPU and then by virtual index
1582 * which provides ordering when rotating groups for the same CPU.
1585 perf_event_groups_less(struct perf_event
*left
, struct perf_event
*right
)
1587 if (left
->cpu
< right
->cpu
)
1589 if (left
->cpu
> right
->cpu
)
1592 #ifdef CONFIG_CGROUP_PERF
1593 if (left
->cgrp
!= right
->cgrp
) {
1594 if (!left
->cgrp
|| !left
->cgrp
->css
.cgroup
) {
1596 * Left has no cgroup but right does, no cgroups come
1601 if (!right
->cgrp
|| !right
->cgrp
->css
.cgroup
) {
1603 * Right has no cgroup but left does, no cgroups come
1608 /* Two dissimilar cgroups, order by id. */
1609 if (left
->cgrp
->css
.cgroup
->kn
->id
< right
->cgrp
->css
.cgroup
->kn
->id
)
1616 if (left
->group_index
< right
->group_index
)
1618 if (left
->group_index
> right
->group_index
)
1625 * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
1626 * key (see perf_event_groups_less). This places it last inside the CPU
1630 perf_event_groups_insert(struct perf_event_groups
*groups
,
1631 struct perf_event
*event
)
1633 struct perf_event
*node_event
;
1634 struct rb_node
*parent
;
1635 struct rb_node
**node
;
1637 event
->group_index
= ++groups
->index
;
1639 node
= &groups
->tree
.rb_node
;
1644 node_event
= container_of(*node
, struct perf_event
, group_node
);
1646 if (perf_event_groups_less(event
, node_event
))
1647 node
= &parent
->rb_left
;
1649 node
= &parent
->rb_right
;
1652 rb_link_node(&event
->group_node
, parent
, node
);
1653 rb_insert_color(&event
->group_node
, &groups
->tree
);
1657 * Helper function to insert event into the pinned or flexible groups.
1660 add_event_to_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1662 struct perf_event_groups
*groups
;
1664 groups
= get_event_groups(event
, ctx
);
1665 perf_event_groups_insert(groups
, event
);
1669 * Delete a group from a tree.
1672 perf_event_groups_delete(struct perf_event_groups
*groups
,
1673 struct perf_event
*event
)
1675 WARN_ON_ONCE(RB_EMPTY_NODE(&event
->group_node
) ||
1676 RB_EMPTY_ROOT(&groups
->tree
));
1678 rb_erase(&event
->group_node
, &groups
->tree
);
1679 init_event_group(event
);
1683 * Helper function to delete event from its groups.
1686 del_event_from_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1688 struct perf_event_groups
*groups
;
1690 groups
= get_event_groups(event
, ctx
);
1691 perf_event_groups_delete(groups
, event
);
1695 * Get the leftmost event in the cpu/cgroup subtree.
1697 static struct perf_event
*
1698 perf_event_groups_first(struct perf_event_groups
*groups
, int cpu
,
1699 struct cgroup
*cgrp
)
1701 struct perf_event
*node_event
= NULL
, *match
= NULL
;
1702 struct rb_node
*node
= groups
->tree
.rb_node
;
1703 #ifdef CONFIG_CGROUP_PERF
1704 u64 node_cgrp_id
, cgrp_id
= 0;
1707 cgrp_id
= cgrp
->kn
->id
;
1711 node_event
= container_of(node
, struct perf_event
, group_node
);
1713 if (cpu
< node_event
->cpu
) {
1714 node
= node
->rb_left
;
1717 if (cpu
> node_event
->cpu
) {
1718 node
= node
->rb_right
;
1721 #ifdef CONFIG_CGROUP_PERF
1723 if (node_event
->cgrp
&& node_event
->cgrp
->css
.cgroup
)
1724 node_cgrp_id
= node_event
->cgrp
->css
.cgroup
->kn
->id
;
1726 if (cgrp_id
< node_cgrp_id
) {
1727 node
= node
->rb_left
;
1730 if (cgrp_id
> node_cgrp_id
) {
1731 node
= node
->rb_right
;
1736 node
= node
->rb_left
;
1743 * Like rb_entry_next_safe() for the @cpu subtree.
1745 static struct perf_event
*
1746 perf_event_groups_next(struct perf_event
*event
)
1748 struct perf_event
*next
;
1749 #ifdef CONFIG_CGROUP_PERF
1750 u64 curr_cgrp_id
= 0;
1751 u64 next_cgrp_id
= 0;
1754 next
= rb_entry_safe(rb_next(&event
->group_node
), typeof(*event
), group_node
);
1755 if (next
== NULL
|| next
->cpu
!= event
->cpu
)
1758 #ifdef CONFIG_CGROUP_PERF
1759 if (event
->cgrp
&& event
->cgrp
->css
.cgroup
)
1760 curr_cgrp_id
= event
->cgrp
->css
.cgroup
->kn
->id
;
1762 if (next
->cgrp
&& next
->cgrp
->css
.cgroup
)
1763 next_cgrp_id
= next
->cgrp
->css
.cgroup
->kn
->id
;
1765 if (curr_cgrp_id
!= next_cgrp_id
)
1772 * Iterate through the whole groups tree.
1774 #define perf_event_groups_for_each(event, groups) \
1775 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1776 typeof(*event), group_node); event; \
1777 event = rb_entry_safe(rb_next(&event->group_node), \
1778 typeof(*event), group_node))
1781 * Add an event from the lists for its context.
1782 * Must be called with ctx->mutex and ctx->lock held.
1785 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1787 lockdep_assert_held(&ctx
->lock
);
1789 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1790 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1792 event
->tstamp
= perf_event_time(event
);
1795 * If we're a stand alone event or group leader, we go to the context
1796 * list, group events are kept attached to the group so that
1797 * perf_group_detach can, at all times, locate all siblings.
1799 if (event
->group_leader
== event
) {
1800 event
->group_caps
= event
->event_caps
;
1801 add_event_to_groups(event
, ctx
);
1804 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1806 if (event
->attr
.inherit_stat
)
1809 if (event
->state
> PERF_EVENT_STATE_OFF
)
1810 perf_cgroup_event_enable(event
, ctx
);
1816 * Initialize event state based on the perf_event_attr::disabled.
1818 static inline void perf_event__state_init(struct perf_event
*event
)
1820 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1821 PERF_EVENT_STATE_INACTIVE
;
1824 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1826 int entry
= sizeof(u64
); /* value */
1830 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1831 size
+= sizeof(u64
);
1833 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1834 size
+= sizeof(u64
);
1836 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1837 entry
+= sizeof(u64
);
1839 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1841 size
+= sizeof(u64
);
1845 event
->read_size
= size
;
1848 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1850 struct perf_sample_data
*data
;
1853 if (sample_type
& PERF_SAMPLE_IP
)
1854 size
+= sizeof(data
->ip
);
1856 if (sample_type
& PERF_SAMPLE_ADDR
)
1857 size
+= sizeof(data
->addr
);
1859 if (sample_type
& PERF_SAMPLE_PERIOD
)
1860 size
+= sizeof(data
->period
);
1862 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1863 size
+= sizeof(data
->weight
);
1865 if (sample_type
& PERF_SAMPLE_READ
)
1866 size
+= event
->read_size
;
1868 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1869 size
+= sizeof(data
->data_src
.val
);
1871 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1872 size
+= sizeof(data
->txn
);
1874 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1875 size
+= sizeof(data
->phys_addr
);
1877 if (sample_type
& PERF_SAMPLE_CGROUP
)
1878 size
+= sizeof(data
->cgroup
);
1880 event
->header_size
= size
;
1884 * Called at perf_event creation and when events are attached/detached from a
1887 static void perf_event__header_size(struct perf_event
*event
)
1889 __perf_event_read_size(event
,
1890 event
->group_leader
->nr_siblings
);
1891 __perf_event_header_size(event
, event
->attr
.sample_type
);
1894 static void perf_event__id_header_size(struct perf_event
*event
)
1896 struct perf_sample_data
*data
;
1897 u64 sample_type
= event
->attr
.sample_type
;
1900 if (sample_type
& PERF_SAMPLE_TID
)
1901 size
+= sizeof(data
->tid_entry
);
1903 if (sample_type
& PERF_SAMPLE_TIME
)
1904 size
+= sizeof(data
->time
);
1906 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1907 size
+= sizeof(data
->id
);
1909 if (sample_type
& PERF_SAMPLE_ID
)
1910 size
+= sizeof(data
->id
);
1912 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1913 size
+= sizeof(data
->stream_id
);
1915 if (sample_type
& PERF_SAMPLE_CPU
)
1916 size
+= sizeof(data
->cpu_entry
);
1918 event
->id_header_size
= size
;
1921 static bool perf_event_validate_size(struct perf_event
*event
)
1924 * The values computed here will be over-written when we actually
1927 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1928 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1929 perf_event__id_header_size(event
);
1932 * Sum the lot; should not exceed the 64k limit we have on records.
1933 * Conservative limit to allow for callchains and other variable fields.
1935 if (event
->read_size
+ event
->header_size
+
1936 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1942 static void perf_group_attach(struct perf_event
*event
)
1944 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1946 lockdep_assert_held(&event
->ctx
->lock
);
1949 * We can have double attach due to group movement in perf_event_open.
1951 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1954 event
->attach_state
|= PERF_ATTACH_GROUP
;
1956 if (group_leader
== event
)
1959 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1961 group_leader
->group_caps
&= event
->event_caps
;
1963 list_add_tail(&event
->sibling_list
, &group_leader
->sibling_list
);
1964 group_leader
->nr_siblings
++;
1966 perf_event__header_size(group_leader
);
1968 for_each_sibling_event(pos
, group_leader
)
1969 perf_event__header_size(pos
);
1973 * Remove an event from the lists for its context.
1974 * Must be called with ctx->mutex and ctx->lock held.
1977 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1979 WARN_ON_ONCE(event
->ctx
!= ctx
);
1980 lockdep_assert_held(&ctx
->lock
);
1983 * We can have double detach due to exit/hot-unplug + close.
1985 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1988 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1991 if (event
->attr
.inherit_stat
)
1994 list_del_rcu(&event
->event_entry
);
1996 if (event
->group_leader
== event
)
1997 del_event_from_groups(event
, ctx
);
2000 * If event was in error state, then keep it
2001 * that way, otherwise bogus counts will be
2002 * returned on read(). The only way to get out
2003 * of error state is by explicit re-enabling
2006 if (event
->state
> PERF_EVENT_STATE_OFF
) {
2007 perf_cgroup_event_disable(event
, ctx
);
2008 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2015 perf_aux_output_match(struct perf_event
*event
, struct perf_event
*aux_event
)
2017 if (!has_aux(aux_event
))
2020 if (!event
->pmu
->aux_output_match
)
2023 return event
->pmu
->aux_output_match(aux_event
);
2026 static void put_event(struct perf_event
*event
);
2027 static void event_sched_out(struct perf_event
*event
,
2028 struct perf_cpu_context
*cpuctx
,
2029 struct perf_event_context
*ctx
);
2031 static void perf_put_aux_event(struct perf_event
*event
)
2033 struct perf_event_context
*ctx
= event
->ctx
;
2034 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2035 struct perf_event
*iter
;
2038 * If event uses aux_event tear down the link
2040 if (event
->aux_event
) {
2041 iter
= event
->aux_event
;
2042 event
->aux_event
= NULL
;
2048 * If the event is an aux_event, tear down all links to
2049 * it from other events.
2051 for_each_sibling_event(iter
, event
->group_leader
) {
2052 if (iter
->aux_event
!= event
)
2055 iter
->aux_event
= NULL
;
2059 * If it's ACTIVE, schedule it out and put it into ERROR
2060 * state so that we don't try to schedule it again. Note
2061 * that perf_event_enable() will clear the ERROR status.
2063 event_sched_out(iter
, cpuctx
, ctx
);
2064 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
2068 static bool perf_need_aux_event(struct perf_event
*event
)
2070 return !!event
->attr
.aux_output
|| !!event
->attr
.aux_sample_size
;
2073 static int perf_get_aux_event(struct perf_event
*event
,
2074 struct perf_event
*group_leader
)
2077 * Our group leader must be an aux event if we want to be
2078 * an aux_output. This way, the aux event will precede its
2079 * aux_output events in the group, and therefore will always
2086 * aux_output and aux_sample_size are mutually exclusive.
2088 if (event
->attr
.aux_output
&& event
->attr
.aux_sample_size
)
2091 if (event
->attr
.aux_output
&&
2092 !perf_aux_output_match(event
, group_leader
))
2095 if (event
->attr
.aux_sample_size
&& !group_leader
->pmu
->snapshot_aux
)
2098 if (!atomic_long_inc_not_zero(&group_leader
->refcount
))
2102 * Link aux_outputs to their aux event; this is undone in
2103 * perf_group_detach() by perf_put_aux_event(). When the
2104 * group in torn down, the aux_output events loose their
2105 * link to the aux_event and can't schedule any more.
2107 event
->aux_event
= group_leader
;
2112 static inline struct list_head
*get_event_list(struct perf_event
*event
)
2114 struct perf_event_context
*ctx
= event
->ctx
;
2115 return event
->attr
.pinned
? &ctx
->pinned_active
: &ctx
->flexible_active
;
2118 static void perf_group_detach(struct perf_event
*event
)
2120 struct perf_event
*sibling
, *tmp
;
2121 struct perf_event_context
*ctx
= event
->ctx
;
2123 lockdep_assert_held(&ctx
->lock
);
2126 * We can have double detach due to exit/hot-unplug + close.
2128 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
2131 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
2133 perf_put_aux_event(event
);
2136 * If this is a sibling, remove it from its group.
2138 if (event
->group_leader
!= event
) {
2139 list_del_init(&event
->sibling_list
);
2140 event
->group_leader
->nr_siblings
--;
2145 * If this was a group event with sibling events then
2146 * upgrade the siblings to singleton events by adding them
2147 * to whatever list we are on.
2149 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, sibling_list
) {
2151 sibling
->group_leader
= sibling
;
2152 list_del_init(&sibling
->sibling_list
);
2154 /* Inherit group flags from the previous leader */
2155 sibling
->group_caps
= event
->group_caps
;
2157 if (!RB_EMPTY_NODE(&event
->group_node
)) {
2158 add_event_to_groups(sibling
, event
->ctx
);
2160 if (sibling
->state
== PERF_EVENT_STATE_ACTIVE
)
2161 list_add_tail(&sibling
->active_list
, get_event_list(sibling
));
2164 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
2168 perf_event__header_size(event
->group_leader
);
2170 for_each_sibling_event(tmp
, event
->group_leader
)
2171 perf_event__header_size(tmp
);
2174 static bool is_orphaned_event(struct perf_event
*event
)
2176 return event
->state
== PERF_EVENT_STATE_DEAD
;
2179 static inline int __pmu_filter_match(struct perf_event
*event
)
2181 struct pmu
*pmu
= event
->pmu
;
2182 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
2186 * Check whether we should attempt to schedule an event group based on
2187 * PMU-specific filtering. An event group can consist of HW and SW events,
2188 * potentially with a SW leader, so we must check all the filters, to
2189 * determine whether a group is schedulable:
2191 static inline int pmu_filter_match(struct perf_event
*event
)
2193 struct perf_event
*sibling
;
2195 if (!__pmu_filter_match(event
))
2198 for_each_sibling_event(sibling
, event
) {
2199 if (!__pmu_filter_match(sibling
))
2207 event_filter_match(struct perf_event
*event
)
2209 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
2210 perf_cgroup_match(event
) && pmu_filter_match(event
);
2214 event_sched_out(struct perf_event
*event
,
2215 struct perf_cpu_context
*cpuctx
,
2216 struct perf_event_context
*ctx
)
2218 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
2220 WARN_ON_ONCE(event
->ctx
!= ctx
);
2221 lockdep_assert_held(&ctx
->lock
);
2223 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2227 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2228 * we can schedule events _OUT_ individually through things like
2229 * __perf_remove_from_context().
2231 list_del_init(&event
->active_list
);
2233 perf_pmu_disable(event
->pmu
);
2235 event
->pmu
->del(event
, 0);
2238 if (READ_ONCE(event
->pending_disable
) >= 0) {
2239 WRITE_ONCE(event
->pending_disable
, -1);
2240 perf_cgroup_event_disable(event
, ctx
);
2241 state
= PERF_EVENT_STATE_OFF
;
2243 perf_event_set_state(event
, state
);
2245 if (!is_software_event(event
))
2246 cpuctx
->active_oncpu
--;
2247 if (!--ctx
->nr_active
)
2248 perf_event_ctx_deactivate(ctx
);
2249 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2251 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
2252 cpuctx
->exclusive
= 0;
2254 perf_pmu_enable(event
->pmu
);
2258 group_sched_out(struct perf_event
*group_event
,
2259 struct perf_cpu_context
*cpuctx
,
2260 struct perf_event_context
*ctx
)
2262 struct perf_event
*event
;
2264 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2267 perf_pmu_disable(ctx
->pmu
);
2269 event_sched_out(group_event
, cpuctx
, ctx
);
2272 * Schedule out siblings (if any):
2274 for_each_sibling_event(event
, group_event
)
2275 event_sched_out(event
, cpuctx
, ctx
);
2277 perf_pmu_enable(ctx
->pmu
);
2279 if (group_event
->attr
.exclusive
)
2280 cpuctx
->exclusive
= 0;
2283 #define DETACH_GROUP 0x01UL
2286 * Cross CPU call to remove a performance event
2288 * We disable the event on the hardware level first. After that we
2289 * remove it from the context list.
2292 __perf_remove_from_context(struct perf_event
*event
,
2293 struct perf_cpu_context
*cpuctx
,
2294 struct perf_event_context
*ctx
,
2297 unsigned long flags
= (unsigned long)info
;
2299 if (ctx
->is_active
& EVENT_TIME
) {
2300 update_context_time(ctx
);
2301 update_cgrp_time_from_cpuctx(cpuctx
);
2304 event_sched_out(event
, cpuctx
, ctx
);
2305 if (flags
& DETACH_GROUP
)
2306 perf_group_detach(event
);
2307 list_del_event(event
, ctx
);
2309 if (!ctx
->nr_events
&& ctx
->is_active
) {
2311 ctx
->rotate_necessary
= 0;
2313 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2314 cpuctx
->task_ctx
= NULL
;
2320 * Remove the event from a task's (or a CPU's) list of events.
2322 * If event->ctx is a cloned context, callers must make sure that
2323 * every task struct that event->ctx->task could possibly point to
2324 * remains valid. This is OK when called from perf_release since
2325 * that only calls us on the top-level context, which can't be a clone.
2326 * When called from perf_event_exit_task, it's OK because the
2327 * context has been detached from its task.
2329 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
2331 struct perf_event_context
*ctx
= event
->ctx
;
2333 lockdep_assert_held(&ctx
->mutex
);
2335 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
2338 * The above event_function_call() can NO-OP when it hits
2339 * TASK_TOMBSTONE. In that case we must already have been detached
2340 * from the context (by perf_event_exit_event()) but the grouping
2341 * might still be in-tact.
2343 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
2344 if ((flags
& DETACH_GROUP
) &&
2345 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
2347 * Since in that case we cannot possibly be scheduled, simply
2350 raw_spin_lock_irq(&ctx
->lock
);
2351 perf_group_detach(event
);
2352 raw_spin_unlock_irq(&ctx
->lock
);
2357 * Cross CPU call to disable a performance event
2359 static void __perf_event_disable(struct perf_event
*event
,
2360 struct perf_cpu_context
*cpuctx
,
2361 struct perf_event_context
*ctx
,
2364 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
2367 if (ctx
->is_active
& EVENT_TIME
) {
2368 update_context_time(ctx
);
2369 update_cgrp_time_from_event(event
);
2372 if (event
== event
->group_leader
)
2373 group_sched_out(event
, cpuctx
, ctx
);
2375 event_sched_out(event
, cpuctx
, ctx
);
2377 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2378 perf_cgroup_event_disable(event
, ctx
);
2384 * If event->ctx is a cloned context, callers must make sure that
2385 * every task struct that event->ctx->task could possibly point to
2386 * remains valid. This condition is satisfied when called through
2387 * perf_event_for_each_child or perf_event_for_each because they
2388 * hold the top-level event's child_mutex, so any descendant that
2389 * goes to exit will block in perf_event_exit_event().
2391 * When called from perf_pending_event it's OK because event->ctx
2392 * is the current context on this CPU and preemption is disabled,
2393 * hence we can't get into perf_event_task_sched_out for this context.
2395 static void _perf_event_disable(struct perf_event
*event
)
2397 struct perf_event_context
*ctx
= event
->ctx
;
2399 raw_spin_lock_irq(&ctx
->lock
);
2400 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2401 raw_spin_unlock_irq(&ctx
->lock
);
2404 raw_spin_unlock_irq(&ctx
->lock
);
2406 event_function_call(event
, __perf_event_disable
, NULL
);
2409 void perf_event_disable_local(struct perf_event
*event
)
2411 event_function_local(event
, __perf_event_disable
, NULL
);
2415 * Strictly speaking kernel users cannot create groups and therefore this
2416 * interface does not need the perf_event_ctx_lock() magic.
2418 void perf_event_disable(struct perf_event
*event
)
2420 struct perf_event_context
*ctx
;
2422 ctx
= perf_event_ctx_lock(event
);
2423 _perf_event_disable(event
);
2424 perf_event_ctx_unlock(event
, ctx
);
2426 EXPORT_SYMBOL_GPL(perf_event_disable
);
2428 void perf_event_disable_inatomic(struct perf_event
*event
)
2430 WRITE_ONCE(event
->pending_disable
, smp_processor_id());
2431 /* can fail, see perf_pending_event_disable() */
2432 irq_work_queue(&event
->pending
);
2435 static void perf_set_shadow_time(struct perf_event
*event
,
2436 struct perf_event_context
*ctx
)
2439 * use the correct time source for the time snapshot
2441 * We could get by without this by leveraging the
2442 * fact that to get to this function, the caller
2443 * has most likely already called update_context_time()
2444 * and update_cgrp_time_xx() and thus both timestamp
2445 * are identical (or very close). Given that tstamp is,
2446 * already adjusted for cgroup, we could say that:
2447 * tstamp - ctx->timestamp
2449 * tstamp - cgrp->timestamp.
2451 * Then, in perf_output_read(), the calculation would
2452 * work with no changes because:
2453 * - event is guaranteed scheduled in
2454 * - no scheduled out in between
2455 * - thus the timestamp would be the same
2457 * But this is a bit hairy.
2459 * So instead, we have an explicit cgroup call to remain
2460 * within the time time source all along. We believe it
2461 * is cleaner and simpler to understand.
2463 if (is_cgroup_event(event
))
2464 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2466 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2469 #define MAX_INTERRUPTS (~0ULL)
2471 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2472 static void perf_log_itrace_start(struct perf_event
*event
);
2475 event_sched_in(struct perf_event
*event
,
2476 struct perf_cpu_context
*cpuctx
,
2477 struct perf_event_context
*ctx
)
2481 WARN_ON_ONCE(event
->ctx
!= ctx
);
2483 lockdep_assert_held(&ctx
->lock
);
2485 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2488 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2490 * Order event::oncpu write to happen before the ACTIVE state is
2491 * visible. This allows perf_event_{stop,read}() to observe the correct
2492 * ->oncpu if it sees ACTIVE.
2495 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2498 * Unthrottle events, since we scheduled we might have missed several
2499 * ticks already, also for a heavily scheduling task there is little
2500 * guarantee it'll get a tick in a timely manner.
2502 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2503 perf_log_throttle(event
, 1);
2504 event
->hw
.interrupts
= 0;
2507 perf_pmu_disable(event
->pmu
);
2509 perf_set_shadow_time(event
, ctx
);
2511 perf_log_itrace_start(event
);
2513 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2514 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2520 if (!is_software_event(event
))
2521 cpuctx
->active_oncpu
++;
2522 if (!ctx
->nr_active
++)
2523 perf_event_ctx_activate(ctx
);
2524 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2527 if (event
->attr
.exclusive
)
2528 cpuctx
->exclusive
= 1;
2531 perf_pmu_enable(event
->pmu
);
2537 group_sched_in(struct perf_event
*group_event
,
2538 struct perf_cpu_context
*cpuctx
,
2539 struct perf_event_context
*ctx
)
2541 struct perf_event
*event
, *partial_group
= NULL
;
2542 struct pmu
*pmu
= ctx
->pmu
;
2544 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2547 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2549 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2550 pmu
->cancel_txn(pmu
);
2551 perf_mux_hrtimer_restart(cpuctx
);
2556 * Schedule in siblings as one group (if any):
2558 for_each_sibling_event(event
, group_event
) {
2559 if (event_sched_in(event
, cpuctx
, ctx
)) {
2560 partial_group
= event
;
2565 if (!pmu
->commit_txn(pmu
))
2570 * Groups can be scheduled in as one unit only, so undo any
2571 * partial group before returning:
2572 * The events up to the failed event are scheduled out normally.
2574 for_each_sibling_event(event
, group_event
) {
2575 if (event
== partial_group
)
2578 event_sched_out(event
, cpuctx
, ctx
);
2580 event_sched_out(group_event
, cpuctx
, ctx
);
2582 pmu
->cancel_txn(pmu
);
2584 perf_mux_hrtimer_restart(cpuctx
);
2590 * Work out whether we can put this event group on the CPU now.
2592 static int group_can_go_on(struct perf_event
*event
,
2593 struct perf_cpu_context
*cpuctx
,
2597 * Groups consisting entirely of software events can always go on.
2599 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2602 * If an exclusive group is already on, no other hardware
2605 if (cpuctx
->exclusive
)
2608 * If this group is exclusive and there are already
2609 * events on the CPU, it can't go on.
2611 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2614 * Otherwise, try to add it if all previous groups were able
2620 static void add_event_to_ctx(struct perf_event
*event
,
2621 struct perf_event_context
*ctx
)
2623 list_add_event(event
, ctx
);
2624 perf_group_attach(event
);
2627 static void ctx_sched_out(struct perf_event_context
*ctx
,
2628 struct perf_cpu_context
*cpuctx
,
2629 enum event_type_t event_type
);
2631 ctx_sched_in(struct perf_event_context
*ctx
,
2632 struct perf_cpu_context
*cpuctx
,
2633 enum event_type_t event_type
,
2634 struct task_struct
*task
);
2636 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2637 struct perf_event_context
*ctx
,
2638 enum event_type_t event_type
)
2640 if (!cpuctx
->task_ctx
)
2643 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2646 ctx_sched_out(ctx
, cpuctx
, event_type
);
2649 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2650 struct perf_event_context
*ctx
,
2651 struct task_struct
*task
)
2653 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2655 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2656 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2658 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2662 * We want to maintain the following priority of scheduling:
2663 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2664 * - task pinned (EVENT_PINNED)
2665 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2666 * - task flexible (EVENT_FLEXIBLE).
2668 * In order to avoid unscheduling and scheduling back in everything every
2669 * time an event is added, only do it for the groups of equal priority and
2672 * This can be called after a batch operation on task events, in which case
2673 * event_type is a bit mask of the types of events involved. For CPU events,
2674 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2676 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2677 struct perf_event_context
*task_ctx
,
2678 enum event_type_t event_type
)
2680 enum event_type_t ctx_event_type
;
2681 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2684 * If pinned groups are involved, flexible groups also need to be
2687 if (event_type
& EVENT_PINNED
)
2688 event_type
|= EVENT_FLEXIBLE
;
2690 ctx_event_type
= event_type
& EVENT_ALL
;
2692 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2694 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2697 * Decide which cpu ctx groups to schedule out based on the types
2698 * of events that caused rescheduling:
2699 * - EVENT_CPU: schedule out corresponding groups;
2700 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2701 * - otherwise, do nothing more.
2704 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2705 else if (ctx_event_type
& EVENT_PINNED
)
2706 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2708 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2709 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2712 void perf_pmu_resched(struct pmu
*pmu
)
2714 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2715 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2717 perf_ctx_lock(cpuctx
, task_ctx
);
2718 ctx_resched(cpuctx
, task_ctx
, EVENT_ALL
|EVENT_CPU
);
2719 perf_ctx_unlock(cpuctx
, task_ctx
);
2723 * Cross CPU call to install and enable a performance event
2725 * Very similar to remote_function() + event_function() but cannot assume that
2726 * things like ctx->is_active and cpuctx->task_ctx are set.
2728 static int __perf_install_in_context(void *info
)
2730 struct perf_event
*event
= info
;
2731 struct perf_event_context
*ctx
= event
->ctx
;
2732 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2733 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2734 bool reprogram
= true;
2737 raw_spin_lock(&cpuctx
->ctx
.lock
);
2739 raw_spin_lock(&ctx
->lock
);
2742 reprogram
= (ctx
->task
== current
);
2745 * If the task is running, it must be running on this CPU,
2746 * otherwise we cannot reprogram things.
2748 * If its not running, we don't care, ctx->lock will
2749 * serialize against it becoming runnable.
2751 if (task_curr(ctx
->task
) && !reprogram
) {
2756 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2757 } else if (task_ctx
) {
2758 raw_spin_lock(&task_ctx
->lock
);
2761 #ifdef CONFIG_CGROUP_PERF
2762 if (event
->state
> PERF_EVENT_STATE_OFF
&& is_cgroup_event(event
)) {
2764 * If the current cgroup doesn't match the event's
2765 * cgroup, we should not try to schedule it.
2767 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2768 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2769 event
->cgrp
->css
.cgroup
);
2774 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2775 add_event_to_ctx(event
, ctx
);
2776 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2778 add_event_to_ctx(event
, ctx
);
2782 perf_ctx_unlock(cpuctx
, task_ctx
);
2787 static bool exclusive_event_installable(struct perf_event
*event
,
2788 struct perf_event_context
*ctx
);
2791 * Attach a performance event to a context.
2793 * Very similar to event_function_call, see comment there.
2796 perf_install_in_context(struct perf_event_context
*ctx
,
2797 struct perf_event
*event
,
2800 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2802 lockdep_assert_held(&ctx
->mutex
);
2804 WARN_ON_ONCE(!exclusive_event_installable(event
, ctx
));
2806 if (event
->cpu
!= -1)
2810 * Ensures that if we can observe event->ctx, both the event and ctx
2811 * will be 'complete'. See perf_iterate_sb_cpu().
2813 smp_store_release(&event
->ctx
, ctx
);
2816 * perf_event_attr::disabled events will not run and can be initialized
2817 * without IPI. Except when this is the first event for the context, in
2818 * that case we need the magic of the IPI to set ctx->is_active.
2820 * The IOC_ENABLE that is sure to follow the creation of a disabled
2821 * event will issue the IPI and reprogram the hardware.
2823 if (__perf_effective_state(event
) == PERF_EVENT_STATE_OFF
&& ctx
->nr_events
) {
2824 raw_spin_lock_irq(&ctx
->lock
);
2825 if (ctx
->task
== TASK_TOMBSTONE
) {
2826 raw_spin_unlock_irq(&ctx
->lock
);
2829 add_event_to_ctx(event
, ctx
);
2830 raw_spin_unlock_irq(&ctx
->lock
);
2835 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2840 * Should not happen, we validate the ctx is still alive before calling.
2842 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2846 * Installing events is tricky because we cannot rely on ctx->is_active
2847 * to be set in case this is the nr_events 0 -> 1 transition.
2849 * Instead we use task_curr(), which tells us if the task is running.
2850 * However, since we use task_curr() outside of rq::lock, we can race
2851 * against the actual state. This means the result can be wrong.
2853 * If we get a false positive, we retry, this is harmless.
2855 * If we get a false negative, things are complicated. If we are after
2856 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2857 * value must be correct. If we're before, it doesn't matter since
2858 * perf_event_context_sched_in() will program the counter.
2860 * However, this hinges on the remote context switch having observed
2861 * our task->perf_event_ctxp[] store, such that it will in fact take
2862 * ctx::lock in perf_event_context_sched_in().
2864 * We do this by task_function_call(), if the IPI fails to hit the task
2865 * we know any future context switch of task must see the
2866 * perf_event_ctpx[] store.
2870 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2871 * task_cpu() load, such that if the IPI then does not find the task
2872 * running, a future context switch of that task must observe the
2877 if (!task_function_call(task
, __perf_install_in_context
, event
))
2880 raw_spin_lock_irq(&ctx
->lock
);
2882 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2884 * Cannot happen because we already checked above (which also
2885 * cannot happen), and we hold ctx->mutex, which serializes us
2886 * against perf_event_exit_task_context().
2888 raw_spin_unlock_irq(&ctx
->lock
);
2892 * If the task is not running, ctx->lock will avoid it becoming so,
2893 * thus we can safely install the event.
2895 if (task_curr(task
)) {
2896 raw_spin_unlock_irq(&ctx
->lock
);
2899 add_event_to_ctx(event
, ctx
);
2900 raw_spin_unlock_irq(&ctx
->lock
);
2904 * Cross CPU call to enable a performance event
2906 static void __perf_event_enable(struct perf_event
*event
,
2907 struct perf_cpu_context
*cpuctx
,
2908 struct perf_event_context
*ctx
,
2911 struct perf_event
*leader
= event
->group_leader
;
2912 struct perf_event_context
*task_ctx
;
2914 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2915 event
->state
<= PERF_EVENT_STATE_ERROR
)
2919 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2921 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2922 perf_cgroup_event_enable(event
, ctx
);
2924 if (!ctx
->is_active
)
2927 if (!event_filter_match(event
)) {
2928 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2933 * If the event is in a group and isn't the group leader,
2934 * then don't put it on unless the group is on.
2936 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2937 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2941 task_ctx
= cpuctx
->task_ctx
;
2943 WARN_ON_ONCE(task_ctx
!= ctx
);
2945 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2951 * If event->ctx is a cloned context, callers must make sure that
2952 * every task struct that event->ctx->task could possibly point to
2953 * remains valid. This condition is satisfied when called through
2954 * perf_event_for_each_child or perf_event_for_each as described
2955 * for perf_event_disable.
2957 static void _perf_event_enable(struct perf_event
*event
)
2959 struct perf_event_context
*ctx
= event
->ctx
;
2961 raw_spin_lock_irq(&ctx
->lock
);
2962 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2963 event
->state
< PERF_EVENT_STATE_ERROR
) {
2964 raw_spin_unlock_irq(&ctx
->lock
);
2969 * If the event is in error state, clear that first.
2971 * That way, if we see the event in error state below, we know that it
2972 * has gone back into error state, as distinct from the task having
2973 * been scheduled away before the cross-call arrived.
2975 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2976 event
->state
= PERF_EVENT_STATE_OFF
;
2977 raw_spin_unlock_irq(&ctx
->lock
);
2979 event_function_call(event
, __perf_event_enable
, NULL
);
2983 * See perf_event_disable();
2985 void perf_event_enable(struct perf_event
*event
)
2987 struct perf_event_context
*ctx
;
2989 ctx
= perf_event_ctx_lock(event
);
2990 _perf_event_enable(event
);
2991 perf_event_ctx_unlock(event
, ctx
);
2993 EXPORT_SYMBOL_GPL(perf_event_enable
);
2995 struct stop_event_data
{
2996 struct perf_event
*event
;
2997 unsigned int restart
;
3000 static int __perf_event_stop(void *info
)
3002 struct stop_event_data
*sd
= info
;
3003 struct perf_event
*event
= sd
->event
;
3005 /* if it's already INACTIVE, do nothing */
3006 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
3009 /* matches smp_wmb() in event_sched_in() */
3013 * There is a window with interrupts enabled before we get here,
3014 * so we need to check again lest we try to stop another CPU's event.
3016 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
3019 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3022 * May race with the actual stop (through perf_pmu_output_stop()),
3023 * but it is only used for events with AUX ring buffer, and such
3024 * events will refuse to restart because of rb::aux_mmap_count==0,
3025 * see comments in perf_aux_output_begin().
3027 * Since this is happening on an event-local CPU, no trace is lost
3031 event
->pmu
->start(event
, 0);
3036 static int perf_event_stop(struct perf_event
*event
, int restart
)
3038 struct stop_event_data sd
= {
3045 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
3048 /* matches smp_wmb() in event_sched_in() */
3052 * We only want to restart ACTIVE events, so if the event goes
3053 * inactive here (event->oncpu==-1), there's nothing more to do;
3054 * fall through with ret==-ENXIO.
3056 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
3057 __perf_event_stop
, &sd
);
3058 } while (ret
== -EAGAIN
);
3064 * In order to contain the amount of racy and tricky in the address filter
3065 * configuration management, it is a two part process:
3067 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
3068 * we update the addresses of corresponding vmas in
3069 * event::addr_filter_ranges array and bump the event::addr_filters_gen;
3070 * (p2) when an event is scheduled in (pmu::add), it calls
3071 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
3072 * if the generation has changed since the previous call.
3074 * If (p1) happens while the event is active, we restart it to force (p2).
3076 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
3077 * pre-existing mappings, called once when new filters arrive via SET_FILTER
3079 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
3080 * registered mapping, called for every new mmap(), with mm::mmap_sem down
3082 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
3085 void perf_event_addr_filters_sync(struct perf_event
*event
)
3087 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
3089 if (!has_addr_filter(event
))
3092 raw_spin_lock(&ifh
->lock
);
3093 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
3094 event
->pmu
->addr_filters_sync(event
);
3095 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
3097 raw_spin_unlock(&ifh
->lock
);
3099 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
3101 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
3104 * not supported on inherited events
3106 if (event
->attr
.inherit
|| !is_sampling_event(event
))
3109 atomic_add(refresh
, &event
->event_limit
);
3110 _perf_event_enable(event
);
3116 * See perf_event_disable()
3118 int perf_event_refresh(struct perf_event
*event
, int refresh
)
3120 struct perf_event_context
*ctx
;
3123 ctx
= perf_event_ctx_lock(event
);
3124 ret
= _perf_event_refresh(event
, refresh
);
3125 perf_event_ctx_unlock(event
, ctx
);
3129 EXPORT_SYMBOL_GPL(perf_event_refresh
);
3131 static int perf_event_modify_breakpoint(struct perf_event
*bp
,
3132 struct perf_event_attr
*attr
)
3136 _perf_event_disable(bp
);
3138 err
= modify_user_hw_breakpoint_check(bp
, attr
, true);
3140 if (!bp
->attr
.disabled
)
3141 _perf_event_enable(bp
);
3146 static int perf_event_modify_attr(struct perf_event
*event
,
3147 struct perf_event_attr
*attr
)
3149 if (event
->attr
.type
!= attr
->type
)
3152 switch (event
->attr
.type
) {
3153 case PERF_TYPE_BREAKPOINT
:
3154 return perf_event_modify_breakpoint(event
, attr
);
3156 /* Place holder for future additions. */
3161 static void ctx_sched_out(struct perf_event_context
*ctx
,
3162 struct perf_cpu_context
*cpuctx
,
3163 enum event_type_t event_type
)
3165 struct perf_event
*event
, *tmp
;
3166 int is_active
= ctx
->is_active
;
3168 lockdep_assert_held(&ctx
->lock
);
3170 if (likely(!ctx
->nr_events
)) {
3172 * See __perf_remove_from_context().
3174 WARN_ON_ONCE(ctx
->is_active
);
3176 WARN_ON_ONCE(cpuctx
->task_ctx
);
3180 ctx
->is_active
&= ~event_type
;
3181 if (!(ctx
->is_active
& EVENT_ALL
))
3185 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3186 if (!ctx
->is_active
)
3187 cpuctx
->task_ctx
= NULL
;
3191 * Always update time if it was set; not only when it changes.
3192 * Otherwise we can 'forget' to update time for any but the last
3193 * context we sched out. For example:
3195 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
3196 * ctx_sched_out(.event_type = EVENT_PINNED)
3198 * would only update time for the pinned events.
3200 if (is_active
& EVENT_TIME
) {
3201 /* update (and stop) ctx time */
3202 update_context_time(ctx
);
3203 update_cgrp_time_from_cpuctx(cpuctx
);
3206 is_active
^= ctx
->is_active
; /* changed bits */
3208 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
3211 perf_pmu_disable(ctx
->pmu
);
3212 if (is_active
& EVENT_PINNED
) {
3213 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_active
, active_list
)
3214 group_sched_out(event
, cpuctx
, ctx
);
3217 if (is_active
& EVENT_FLEXIBLE
) {
3218 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_active
, active_list
)
3219 group_sched_out(event
, cpuctx
, ctx
);
3222 * Since we cleared EVENT_FLEXIBLE, also clear
3223 * rotate_necessary, is will be reset by
3224 * ctx_flexible_sched_in() when needed.
3226 ctx
->rotate_necessary
= 0;
3228 perf_pmu_enable(ctx
->pmu
);
3232 * Test whether two contexts are equivalent, i.e. whether they have both been
3233 * cloned from the same version of the same context.
3235 * Equivalence is measured using a generation number in the context that is
3236 * incremented on each modification to it; see unclone_ctx(), list_add_event()
3237 * and list_del_event().
3239 static int context_equiv(struct perf_event_context
*ctx1
,
3240 struct perf_event_context
*ctx2
)
3242 lockdep_assert_held(&ctx1
->lock
);
3243 lockdep_assert_held(&ctx2
->lock
);
3245 /* Pinning disables the swap optimization */
3246 if (ctx1
->pin_count
|| ctx2
->pin_count
)
3249 /* If ctx1 is the parent of ctx2 */
3250 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
3253 /* If ctx2 is the parent of ctx1 */
3254 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
3258 * If ctx1 and ctx2 have the same parent; we flatten the parent
3259 * hierarchy, see perf_event_init_context().
3261 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
3262 ctx1
->parent_gen
== ctx2
->parent_gen
)
3269 static void __perf_event_sync_stat(struct perf_event
*event
,
3270 struct perf_event
*next_event
)
3274 if (!event
->attr
.inherit_stat
)
3278 * Update the event value, we cannot use perf_event_read()
3279 * because we're in the middle of a context switch and have IRQs
3280 * disabled, which upsets smp_call_function_single(), however
3281 * we know the event must be on the current CPU, therefore we
3282 * don't need to use it.
3284 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3285 event
->pmu
->read(event
);
3287 perf_event_update_time(event
);
3290 * In order to keep per-task stats reliable we need to flip the event
3291 * values when we flip the contexts.
3293 value
= local64_read(&next_event
->count
);
3294 value
= local64_xchg(&event
->count
, value
);
3295 local64_set(&next_event
->count
, value
);
3297 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
3298 swap(event
->total_time_running
, next_event
->total_time_running
);
3301 * Since we swizzled the values, update the user visible data too.
3303 perf_event_update_userpage(event
);
3304 perf_event_update_userpage(next_event
);
3307 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
3308 struct perf_event_context
*next_ctx
)
3310 struct perf_event
*event
, *next_event
;
3315 update_context_time(ctx
);
3317 event
= list_first_entry(&ctx
->event_list
,
3318 struct perf_event
, event_entry
);
3320 next_event
= list_first_entry(&next_ctx
->event_list
,
3321 struct perf_event
, event_entry
);
3323 while (&event
->event_entry
!= &ctx
->event_list
&&
3324 &next_event
->event_entry
!= &next_ctx
->event_list
) {
3326 __perf_event_sync_stat(event
, next_event
);
3328 event
= list_next_entry(event
, event_entry
);
3329 next_event
= list_next_entry(next_event
, event_entry
);
3333 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
3334 struct task_struct
*next
)
3336 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
3337 struct perf_event_context
*next_ctx
;
3338 struct perf_event_context
*parent
, *next_parent
;
3339 struct perf_cpu_context
*cpuctx
;
3345 cpuctx
= __get_cpu_context(ctx
);
3346 if (!cpuctx
->task_ctx
)
3350 next_ctx
= next
->perf_event_ctxp
[ctxn
];
3354 parent
= rcu_dereference(ctx
->parent_ctx
);
3355 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
3357 /* If neither context have a parent context; they cannot be clones. */
3358 if (!parent
&& !next_parent
)
3361 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
3363 * Looks like the two contexts are clones, so we might be
3364 * able to optimize the context switch. We lock both
3365 * contexts and check that they are clones under the
3366 * lock (including re-checking that neither has been
3367 * uncloned in the meantime). It doesn't matter which
3368 * order we take the locks because no other cpu could
3369 * be trying to lock both of these tasks.
3371 raw_spin_lock(&ctx
->lock
);
3372 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3373 if (context_equiv(ctx
, next_ctx
)) {
3374 struct pmu
*pmu
= ctx
->pmu
;
3376 WRITE_ONCE(ctx
->task
, next
);
3377 WRITE_ONCE(next_ctx
->task
, task
);
3380 * PMU specific parts of task perf context can require
3381 * additional synchronization. As an example of such
3382 * synchronization see implementation details of Intel
3383 * LBR call stack data profiling;
3385 if (pmu
->swap_task_ctx
)
3386 pmu
->swap_task_ctx(ctx
, next_ctx
);
3388 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3391 * RCU_INIT_POINTER here is safe because we've not
3392 * modified the ctx and the above modification of
3393 * ctx->task and ctx->task_ctx_data are immaterial
3394 * since those values are always verified under
3395 * ctx->lock which we're now holding.
3397 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3398 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3402 perf_event_sync_stat(ctx
, next_ctx
);
3404 raw_spin_unlock(&next_ctx
->lock
);
3405 raw_spin_unlock(&ctx
->lock
);
3411 raw_spin_lock(&ctx
->lock
);
3412 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3413 raw_spin_unlock(&ctx
->lock
);
3417 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3419 void perf_sched_cb_dec(struct pmu
*pmu
)
3421 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3423 this_cpu_dec(perf_sched_cb_usages
);
3425 if (!--cpuctx
->sched_cb_usage
)
3426 list_del(&cpuctx
->sched_cb_entry
);
3430 void perf_sched_cb_inc(struct pmu
*pmu
)
3432 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3434 if (!cpuctx
->sched_cb_usage
++)
3435 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3437 this_cpu_inc(perf_sched_cb_usages
);
3441 * This function provides the context switch callback to the lower code
3442 * layer. It is invoked ONLY when the context switch callback is enabled.
3444 * This callback is relevant even to per-cpu events; for example multi event
3445 * PEBS requires this to provide PID/TID information. This requires we flush
3446 * all queued PEBS records before we context switch to a new task.
3448 static void perf_pmu_sched_task(struct task_struct
*prev
,
3449 struct task_struct
*next
,
3452 struct perf_cpu_context
*cpuctx
;
3458 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3459 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3461 if (WARN_ON_ONCE(!pmu
->sched_task
))
3464 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3465 perf_pmu_disable(pmu
);
3467 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3469 perf_pmu_enable(pmu
);
3470 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3474 static void perf_event_switch(struct task_struct
*task
,
3475 struct task_struct
*next_prev
, bool sched_in
);
3477 #define for_each_task_context_nr(ctxn) \
3478 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3481 * Called from scheduler to remove the events of the current task,
3482 * with interrupts disabled.
3484 * We stop each event and update the event value in event->count.
3486 * This does not protect us against NMI, but disable()
3487 * sets the disabled bit in the control field of event _before_
3488 * accessing the event control register. If a NMI hits, then it will
3489 * not restart the event.
3491 void __perf_event_task_sched_out(struct task_struct
*task
,
3492 struct task_struct
*next
)
3496 if (__this_cpu_read(perf_sched_cb_usages
))
3497 perf_pmu_sched_task(task
, next
, false);
3499 if (atomic_read(&nr_switch_events
))
3500 perf_event_switch(task
, next
, false);
3502 for_each_task_context_nr(ctxn
)
3503 perf_event_context_sched_out(task
, ctxn
, next
);
3506 * if cgroup events exist on this CPU, then we need
3507 * to check if we have to switch out PMU state.
3508 * cgroup event are system-wide mode only
3510 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3511 perf_cgroup_sched_out(task
, next
);
3515 * Called with IRQs disabled
3517 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3518 enum event_type_t event_type
)
3520 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3523 static bool perf_less_group_idx(const void *l
, const void *r
)
3525 const struct perf_event
*le
= *(const struct perf_event
**)l
;
3526 const struct perf_event
*re
= *(const struct perf_event
**)r
;
3528 return le
->group_index
< re
->group_index
;
3531 static void swap_ptr(void *l
, void *r
)
3533 void **lp
= l
, **rp
= r
;
3538 static const struct min_heap_callbacks perf_min_heap
= {
3539 .elem_size
= sizeof(struct perf_event
*),
3540 .less
= perf_less_group_idx
,
3544 static void __heap_add(struct min_heap
*heap
, struct perf_event
*event
)
3546 struct perf_event
**itrs
= heap
->data
;
3549 itrs
[heap
->nr
] = event
;
3554 static noinline
int visit_groups_merge(struct perf_cpu_context
*cpuctx
,
3555 struct perf_event_groups
*groups
, int cpu
,
3556 int (*func
)(struct perf_event
*, void *),
3559 #ifdef CONFIG_CGROUP_PERF
3560 struct cgroup_subsys_state
*css
= NULL
;
3562 /* Space for per CPU and/or any CPU event iterators. */
3563 struct perf_event
*itrs
[2];
3564 struct min_heap event_heap
;
3565 struct perf_event
**evt
;
3569 event_heap
= (struct min_heap
){
3570 .data
= cpuctx
->heap
,
3572 .size
= cpuctx
->heap_size
,
3575 lockdep_assert_held(&cpuctx
->ctx
.lock
);
3577 #ifdef CONFIG_CGROUP_PERF
3579 css
= &cpuctx
->cgrp
->css
;
3582 event_heap
= (struct min_heap
){
3585 .size
= ARRAY_SIZE(itrs
),
3587 /* Events not within a CPU context may be on any CPU. */
3588 __heap_add(&event_heap
, perf_event_groups_first(groups
, -1, NULL
));
3590 evt
= event_heap
.data
;
3592 __heap_add(&event_heap
, perf_event_groups_first(groups
, cpu
, NULL
));
3594 #ifdef CONFIG_CGROUP_PERF
3595 for (; css
; css
= css
->parent
)
3596 __heap_add(&event_heap
, perf_event_groups_first(groups
, cpu
, css
->cgroup
));
3599 min_heapify_all(&event_heap
, &perf_min_heap
);
3601 while (event_heap
.nr
) {
3602 ret
= func(*evt
, data
);
3606 *evt
= perf_event_groups_next(*evt
);
3608 min_heapify(&event_heap
, 0, &perf_min_heap
);
3610 min_heap_pop(&event_heap
, &perf_min_heap
);
3616 static int merge_sched_in(struct perf_event
*event
, void *data
)
3618 struct perf_event_context
*ctx
= event
->ctx
;
3619 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3620 int *can_add_hw
= data
;
3622 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3625 if (!event_filter_match(event
))
3628 if (group_can_go_on(event
, cpuctx
, *can_add_hw
)) {
3629 if (!group_sched_in(event
, cpuctx
, ctx
))
3630 list_add_tail(&event
->active_list
, get_event_list(event
));
3633 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3634 if (event
->attr
.pinned
) {
3635 perf_cgroup_event_disable(event
, ctx
);
3636 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3640 ctx
->rotate_necessary
= 1;
3647 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3648 struct perf_cpu_context
*cpuctx
)
3652 if (ctx
!= &cpuctx
->ctx
)
3655 visit_groups_merge(cpuctx
, &ctx
->pinned_groups
,
3657 merge_sched_in
, &can_add_hw
);
3661 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3662 struct perf_cpu_context
*cpuctx
)
3666 if (ctx
!= &cpuctx
->ctx
)
3669 visit_groups_merge(cpuctx
, &ctx
->flexible_groups
,
3671 merge_sched_in
, &can_add_hw
);
3675 ctx_sched_in(struct perf_event_context
*ctx
,
3676 struct perf_cpu_context
*cpuctx
,
3677 enum event_type_t event_type
,
3678 struct task_struct
*task
)
3680 int is_active
= ctx
->is_active
;
3683 lockdep_assert_held(&ctx
->lock
);
3685 if (likely(!ctx
->nr_events
))
3688 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3691 cpuctx
->task_ctx
= ctx
;
3693 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3696 is_active
^= ctx
->is_active
; /* changed bits */
3698 if (is_active
& EVENT_TIME
) {
3699 /* start ctx time */
3701 ctx
->timestamp
= now
;
3702 perf_cgroup_set_timestamp(task
, ctx
);
3706 * First go through the list and put on any pinned groups
3707 * in order to give them the best chance of going on.
3709 if (is_active
& EVENT_PINNED
)
3710 ctx_pinned_sched_in(ctx
, cpuctx
);
3712 /* Then walk through the lower prio flexible groups */
3713 if (is_active
& EVENT_FLEXIBLE
)
3714 ctx_flexible_sched_in(ctx
, cpuctx
);
3717 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3718 enum event_type_t event_type
,
3719 struct task_struct
*task
)
3721 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3723 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3726 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3727 struct task_struct
*task
)
3729 struct perf_cpu_context
*cpuctx
;
3731 cpuctx
= __get_cpu_context(ctx
);
3732 if (cpuctx
->task_ctx
== ctx
)
3735 perf_ctx_lock(cpuctx
, ctx
);
3737 * We must check ctx->nr_events while holding ctx->lock, such
3738 * that we serialize against perf_install_in_context().
3740 if (!ctx
->nr_events
)
3743 perf_pmu_disable(ctx
->pmu
);
3745 * We want to keep the following priority order:
3746 * cpu pinned (that don't need to move), task pinned,
3747 * cpu flexible, task flexible.
3749 * However, if task's ctx is not carrying any pinned
3750 * events, no need to flip the cpuctx's events around.
3752 if (!RB_EMPTY_ROOT(&ctx
->pinned_groups
.tree
))
3753 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3754 perf_event_sched_in(cpuctx
, ctx
, task
);
3755 perf_pmu_enable(ctx
->pmu
);
3758 perf_ctx_unlock(cpuctx
, ctx
);
3762 * Called from scheduler to add the events of the current task
3763 * with interrupts disabled.
3765 * We restore the event value and then enable it.
3767 * This does not protect us against NMI, but enable()
3768 * sets the enabled bit in the control field of event _before_
3769 * accessing the event control register. If a NMI hits, then it will
3770 * keep the event running.
3772 void __perf_event_task_sched_in(struct task_struct
*prev
,
3773 struct task_struct
*task
)
3775 struct perf_event_context
*ctx
;
3779 * If cgroup events exist on this CPU, then we need to check if we have
3780 * to switch in PMU state; cgroup event are system-wide mode only.
3782 * Since cgroup events are CPU events, we must schedule these in before
3783 * we schedule in the task events.
3785 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3786 perf_cgroup_sched_in(prev
, task
);
3788 for_each_task_context_nr(ctxn
) {
3789 ctx
= task
->perf_event_ctxp
[ctxn
];
3793 perf_event_context_sched_in(ctx
, task
);
3796 if (atomic_read(&nr_switch_events
))
3797 perf_event_switch(task
, prev
, true);
3799 if (__this_cpu_read(perf_sched_cb_usages
))
3800 perf_pmu_sched_task(prev
, task
, true);
3803 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3805 u64 frequency
= event
->attr
.sample_freq
;
3806 u64 sec
= NSEC_PER_SEC
;
3807 u64 divisor
, dividend
;
3809 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3811 count_fls
= fls64(count
);
3812 nsec_fls
= fls64(nsec
);
3813 frequency_fls
= fls64(frequency
);
3817 * We got @count in @nsec, with a target of sample_freq HZ
3818 * the target period becomes:
3821 * period = -------------------
3822 * @nsec * sample_freq
3827 * Reduce accuracy by one bit such that @a and @b converge
3828 * to a similar magnitude.
3830 #define REDUCE_FLS(a, b) \
3832 if (a##_fls > b##_fls) { \
3842 * Reduce accuracy until either term fits in a u64, then proceed with
3843 * the other, so that finally we can do a u64/u64 division.
3845 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3846 REDUCE_FLS(nsec
, frequency
);
3847 REDUCE_FLS(sec
, count
);
3850 if (count_fls
+ sec_fls
> 64) {
3851 divisor
= nsec
* frequency
;
3853 while (count_fls
+ sec_fls
> 64) {
3854 REDUCE_FLS(count
, sec
);
3858 dividend
= count
* sec
;
3860 dividend
= count
* sec
;
3862 while (nsec_fls
+ frequency_fls
> 64) {
3863 REDUCE_FLS(nsec
, frequency
);
3867 divisor
= nsec
* frequency
;
3873 return div64_u64(dividend
, divisor
);
3876 static DEFINE_PER_CPU(int, perf_throttled_count
);
3877 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3879 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3881 struct hw_perf_event
*hwc
= &event
->hw
;
3882 s64 period
, sample_period
;
3885 period
= perf_calculate_period(event
, nsec
, count
);
3887 delta
= (s64
)(period
- hwc
->sample_period
);
3888 delta
= (delta
+ 7) / 8; /* low pass filter */
3890 sample_period
= hwc
->sample_period
+ delta
;
3895 hwc
->sample_period
= sample_period
;
3897 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3899 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3901 local64_set(&hwc
->period_left
, 0);
3904 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3909 * combine freq adjustment with unthrottling to avoid two passes over the
3910 * events. At the same time, make sure, having freq events does not change
3911 * the rate of unthrottling as that would introduce bias.
3913 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3916 struct perf_event
*event
;
3917 struct hw_perf_event
*hwc
;
3918 u64 now
, period
= TICK_NSEC
;
3922 * only need to iterate over all events iff:
3923 * - context have events in frequency mode (needs freq adjust)
3924 * - there are events to unthrottle on this cpu
3926 if (!(ctx
->nr_freq
|| needs_unthr
))
3929 raw_spin_lock(&ctx
->lock
);
3930 perf_pmu_disable(ctx
->pmu
);
3932 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3933 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3936 if (!event_filter_match(event
))
3939 perf_pmu_disable(event
->pmu
);
3943 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3944 hwc
->interrupts
= 0;
3945 perf_log_throttle(event
, 1);
3946 event
->pmu
->start(event
, 0);
3949 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3953 * stop the event and update event->count
3955 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3957 now
= local64_read(&event
->count
);
3958 delta
= now
- hwc
->freq_count_stamp
;
3959 hwc
->freq_count_stamp
= now
;
3963 * reload only if value has changed
3964 * we have stopped the event so tell that
3965 * to perf_adjust_period() to avoid stopping it
3969 perf_adjust_period(event
, period
, delta
, false);
3971 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3973 perf_pmu_enable(event
->pmu
);
3976 perf_pmu_enable(ctx
->pmu
);
3977 raw_spin_unlock(&ctx
->lock
);
3981 * Move @event to the tail of the @ctx's elegible events.
3983 static void rotate_ctx(struct perf_event_context
*ctx
, struct perf_event
*event
)
3986 * Rotate the first entry last of non-pinned groups. Rotation might be
3987 * disabled by the inheritance code.
3989 if (ctx
->rotate_disable
)
3992 perf_event_groups_delete(&ctx
->flexible_groups
, event
);
3993 perf_event_groups_insert(&ctx
->flexible_groups
, event
);
3996 /* pick an event from the flexible_groups to rotate */
3997 static inline struct perf_event
*
3998 ctx_event_to_rotate(struct perf_event_context
*ctx
)
4000 struct perf_event
*event
;
4002 /* pick the first active flexible event */
4003 event
= list_first_entry_or_null(&ctx
->flexible_active
,
4004 struct perf_event
, active_list
);
4006 /* if no active flexible event, pick the first event */
4008 event
= rb_entry_safe(rb_first(&ctx
->flexible_groups
.tree
),
4009 typeof(*event
), group_node
);
4013 * Unconditionally clear rotate_necessary; if ctx_flexible_sched_in()
4014 * finds there are unschedulable events, it will set it again.
4016 ctx
->rotate_necessary
= 0;
4021 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
)
4023 struct perf_event
*cpu_event
= NULL
, *task_event
= NULL
;
4024 struct perf_event_context
*task_ctx
= NULL
;
4025 int cpu_rotate
, task_rotate
;
4028 * Since we run this from IRQ context, nobody can install new
4029 * events, thus the event count values are stable.
4032 cpu_rotate
= cpuctx
->ctx
.rotate_necessary
;
4033 task_ctx
= cpuctx
->task_ctx
;
4034 task_rotate
= task_ctx
? task_ctx
->rotate_necessary
: 0;
4036 if (!(cpu_rotate
|| task_rotate
))
4039 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
4040 perf_pmu_disable(cpuctx
->ctx
.pmu
);
4043 task_event
= ctx_event_to_rotate(task_ctx
);
4045 cpu_event
= ctx_event_to_rotate(&cpuctx
->ctx
);
4048 * As per the order given at ctx_resched() first 'pop' task flexible
4049 * and then, if needed CPU flexible.
4051 if (task_event
|| (task_ctx
&& cpu_event
))
4052 ctx_sched_out(task_ctx
, cpuctx
, EVENT_FLEXIBLE
);
4054 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
4057 rotate_ctx(task_ctx
, task_event
);
4059 rotate_ctx(&cpuctx
->ctx
, cpu_event
);
4061 perf_event_sched_in(cpuctx
, task_ctx
, current
);
4063 perf_pmu_enable(cpuctx
->ctx
.pmu
);
4064 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
4069 void perf_event_task_tick(void)
4071 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
4072 struct perf_event_context
*ctx
, *tmp
;
4075 lockdep_assert_irqs_disabled();
4077 __this_cpu_inc(perf_throttled_seq
);
4078 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
4079 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
4081 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
4082 perf_adjust_freq_unthr_context(ctx
, throttled
);
4085 static int event_enable_on_exec(struct perf_event
*event
,
4086 struct perf_event_context
*ctx
)
4088 if (!event
->attr
.enable_on_exec
)
4091 event
->attr
.enable_on_exec
= 0;
4092 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
4095 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
4101 * Enable all of a task's events that have been marked enable-on-exec.
4102 * This expects task == current.
4104 static void perf_event_enable_on_exec(int ctxn
)
4106 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4107 enum event_type_t event_type
= 0;
4108 struct perf_cpu_context
*cpuctx
;
4109 struct perf_event
*event
;
4110 unsigned long flags
;
4113 local_irq_save(flags
);
4114 ctx
= current
->perf_event_ctxp
[ctxn
];
4115 if (!ctx
|| !ctx
->nr_events
)
4118 cpuctx
= __get_cpu_context(ctx
);
4119 perf_ctx_lock(cpuctx
, ctx
);
4120 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
4121 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
4122 enabled
|= event_enable_on_exec(event
, ctx
);
4123 event_type
|= get_event_type(event
);
4127 * Unclone and reschedule this context if we enabled any event.
4130 clone_ctx
= unclone_ctx(ctx
);
4131 ctx_resched(cpuctx
, ctx
, event_type
);
4133 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
4135 perf_ctx_unlock(cpuctx
, ctx
);
4138 local_irq_restore(flags
);
4144 struct perf_read_data
{
4145 struct perf_event
*event
;
4150 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
4152 u16 local_pkg
, event_pkg
;
4154 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
4155 int local_cpu
= smp_processor_id();
4157 event_pkg
= topology_physical_package_id(event_cpu
);
4158 local_pkg
= topology_physical_package_id(local_cpu
);
4160 if (event_pkg
== local_pkg
)
4168 * Cross CPU call to read the hardware event
4170 static void __perf_event_read(void *info
)
4172 struct perf_read_data
*data
= info
;
4173 struct perf_event
*sub
, *event
= data
->event
;
4174 struct perf_event_context
*ctx
= event
->ctx
;
4175 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
4176 struct pmu
*pmu
= event
->pmu
;
4179 * If this is a task context, we need to check whether it is
4180 * the current task context of this cpu. If not it has been
4181 * scheduled out before the smp call arrived. In that case
4182 * event->count would have been updated to a recent sample
4183 * when the event was scheduled out.
4185 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
4188 raw_spin_lock(&ctx
->lock
);
4189 if (ctx
->is_active
& EVENT_TIME
) {
4190 update_context_time(ctx
);
4191 update_cgrp_time_from_event(event
);
4194 perf_event_update_time(event
);
4196 perf_event_update_sibling_time(event
);
4198 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4207 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
4211 for_each_sibling_event(sub
, event
) {
4212 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
4214 * Use sibling's PMU rather than @event's since
4215 * sibling could be on different (eg: software) PMU.
4217 sub
->pmu
->read(sub
);
4221 data
->ret
= pmu
->commit_txn(pmu
);
4224 raw_spin_unlock(&ctx
->lock
);
4227 static inline u64
perf_event_count(struct perf_event
*event
)
4229 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
4233 * NMI-safe method to read a local event, that is an event that
4235 * - either for the current task, or for this CPU
4236 * - does not have inherit set, for inherited task events
4237 * will not be local and we cannot read them atomically
4238 * - must not have a pmu::count method
4240 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
4241 u64
*enabled
, u64
*running
)
4243 unsigned long flags
;
4247 * Disabling interrupts avoids all counter scheduling (context
4248 * switches, timer based rotation and IPIs).
4250 local_irq_save(flags
);
4253 * It must not be an event with inherit set, we cannot read
4254 * all child counters from atomic context.
4256 if (event
->attr
.inherit
) {
4261 /* If this is a per-task event, it must be for current */
4262 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
4263 event
->hw
.target
!= current
) {
4268 /* If this is a per-CPU event, it must be for this CPU */
4269 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
4270 event
->cpu
!= smp_processor_id()) {
4275 /* If this is a pinned event it must be running on this CPU */
4276 if (event
->attr
.pinned
&& event
->oncpu
!= smp_processor_id()) {
4282 * If the event is currently on this CPU, its either a per-task event,
4283 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
4286 if (event
->oncpu
== smp_processor_id())
4287 event
->pmu
->read(event
);
4289 *value
= local64_read(&event
->count
);
4290 if (enabled
|| running
) {
4291 u64 now
= event
->shadow_ctx_time
+ perf_clock();
4292 u64 __enabled
, __running
;
4294 __perf_update_times(event
, now
, &__enabled
, &__running
);
4296 *enabled
= __enabled
;
4298 *running
= __running
;
4301 local_irq_restore(flags
);
4306 static int perf_event_read(struct perf_event
*event
, bool group
)
4308 enum perf_event_state state
= READ_ONCE(event
->state
);
4309 int event_cpu
, ret
= 0;
4312 * If event is enabled and currently active on a CPU, update the
4313 * value in the event structure:
4316 if (state
== PERF_EVENT_STATE_ACTIVE
) {
4317 struct perf_read_data data
;
4320 * Orders the ->state and ->oncpu loads such that if we see
4321 * ACTIVE we must also see the right ->oncpu.
4323 * Matches the smp_wmb() from event_sched_in().
4327 event_cpu
= READ_ONCE(event
->oncpu
);
4328 if ((unsigned)event_cpu
>= nr_cpu_ids
)
4331 data
= (struct perf_read_data
){
4338 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
4341 * Purposely ignore the smp_call_function_single() return
4344 * If event_cpu isn't a valid CPU it means the event got
4345 * scheduled out and that will have updated the event count.
4347 * Therefore, either way, we'll have an up-to-date event count
4350 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
4354 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
4355 struct perf_event_context
*ctx
= event
->ctx
;
4356 unsigned long flags
;
4358 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4359 state
= event
->state
;
4360 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
4361 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4366 * May read while context is not active (e.g., thread is
4367 * blocked), in that case we cannot update context time
4369 if (ctx
->is_active
& EVENT_TIME
) {
4370 update_context_time(ctx
);
4371 update_cgrp_time_from_event(event
);
4374 perf_event_update_time(event
);
4376 perf_event_update_sibling_time(event
);
4377 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4384 * Initialize the perf_event context in a task_struct:
4386 static void __perf_event_init_context(struct perf_event_context
*ctx
)
4388 raw_spin_lock_init(&ctx
->lock
);
4389 mutex_init(&ctx
->mutex
);
4390 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
4391 perf_event_groups_init(&ctx
->pinned_groups
);
4392 perf_event_groups_init(&ctx
->flexible_groups
);
4393 INIT_LIST_HEAD(&ctx
->event_list
);
4394 INIT_LIST_HEAD(&ctx
->pinned_active
);
4395 INIT_LIST_HEAD(&ctx
->flexible_active
);
4396 refcount_set(&ctx
->refcount
, 1);
4399 static struct perf_event_context
*
4400 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
4402 struct perf_event_context
*ctx
;
4404 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
4408 __perf_event_init_context(ctx
);
4410 ctx
->task
= get_task_struct(task
);
4416 static struct task_struct
*
4417 find_lively_task_by_vpid(pid_t vpid
)
4419 struct task_struct
*task
;
4425 task
= find_task_by_vpid(vpid
);
4427 get_task_struct(task
);
4431 return ERR_PTR(-ESRCH
);
4437 * Returns a matching context with refcount and pincount.
4439 static struct perf_event_context
*
4440 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
4441 struct perf_event
*event
)
4443 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4444 struct perf_cpu_context
*cpuctx
;
4445 void *task_ctx_data
= NULL
;
4446 unsigned long flags
;
4448 int cpu
= event
->cpu
;
4451 /* Must be root to operate on a CPU event: */
4452 err
= perf_allow_cpu(&event
->attr
);
4454 return ERR_PTR(err
);
4456 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
4465 ctxn
= pmu
->task_ctx_nr
;
4469 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
4470 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
4471 if (!task_ctx_data
) {
4478 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
4480 clone_ctx
= unclone_ctx(ctx
);
4483 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
4484 ctx
->task_ctx_data
= task_ctx_data
;
4485 task_ctx_data
= NULL
;
4487 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4492 ctx
= alloc_perf_context(pmu
, task
);
4497 if (task_ctx_data
) {
4498 ctx
->task_ctx_data
= task_ctx_data
;
4499 task_ctx_data
= NULL
;
4503 mutex_lock(&task
->perf_event_mutex
);
4505 * If it has already passed perf_event_exit_task().
4506 * we must see PF_EXITING, it takes this mutex too.
4508 if (task
->flags
& PF_EXITING
)
4510 else if (task
->perf_event_ctxp
[ctxn
])
4515 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
4517 mutex_unlock(&task
->perf_event_mutex
);
4519 if (unlikely(err
)) {
4528 kfree(task_ctx_data
);
4532 kfree(task_ctx_data
);
4533 return ERR_PTR(err
);
4536 static void perf_event_free_filter(struct perf_event
*event
);
4537 static void perf_event_free_bpf_prog(struct perf_event
*event
);
4539 static void free_event_rcu(struct rcu_head
*head
)
4541 struct perf_event
*event
;
4543 event
= container_of(head
, struct perf_event
, rcu_head
);
4545 put_pid_ns(event
->ns
);
4546 perf_event_free_filter(event
);
4550 static void ring_buffer_attach(struct perf_event
*event
,
4551 struct perf_buffer
*rb
);
4553 static void detach_sb_event(struct perf_event
*event
)
4555 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4557 raw_spin_lock(&pel
->lock
);
4558 list_del_rcu(&event
->sb_list
);
4559 raw_spin_unlock(&pel
->lock
);
4562 static bool is_sb_event(struct perf_event
*event
)
4564 struct perf_event_attr
*attr
= &event
->attr
;
4569 if (event
->attach_state
& PERF_ATTACH_TASK
)
4572 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4573 attr
->comm
|| attr
->comm_exec
||
4574 attr
->task
|| attr
->ksymbol
||
4575 attr
->context_switch
||
4581 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4583 if (is_sb_event(event
))
4584 detach_sb_event(event
);
4587 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4592 if (is_cgroup_event(event
))
4593 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4596 #ifdef CONFIG_NO_HZ_FULL
4597 static DEFINE_SPINLOCK(nr_freq_lock
);
4600 static void unaccount_freq_event_nohz(void)
4602 #ifdef CONFIG_NO_HZ_FULL
4603 spin_lock(&nr_freq_lock
);
4604 if (atomic_dec_and_test(&nr_freq_events
))
4605 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4606 spin_unlock(&nr_freq_lock
);
4610 static void unaccount_freq_event(void)
4612 if (tick_nohz_full_enabled())
4613 unaccount_freq_event_nohz();
4615 atomic_dec(&nr_freq_events
);
4618 static void unaccount_event(struct perf_event
*event
)
4625 if (event
->attach_state
& PERF_ATTACH_TASK
)
4627 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4628 atomic_dec(&nr_mmap_events
);
4629 if (event
->attr
.comm
)
4630 atomic_dec(&nr_comm_events
);
4631 if (event
->attr
.namespaces
)
4632 atomic_dec(&nr_namespaces_events
);
4633 if (event
->attr
.cgroup
)
4634 atomic_dec(&nr_cgroup_events
);
4635 if (event
->attr
.task
)
4636 atomic_dec(&nr_task_events
);
4637 if (event
->attr
.freq
)
4638 unaccount_freq_event();
4639 if (event
->attr
.context_switch
) {
4641 atomic_dec(&nr_switch_events
);
4643 if (is_cgroup_event(event
))
4645 if (has_branch_stack(event
))
4647 if (event
->attr
.ksymbol
)
4648 atomic_dec(&nr_ksymbol_events
);
4649 if (event
->attr
.bpf_event
)
4650 atomic_dec(&nr_bpf_events
);
4653 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4654 schedule_delayed_work(&perf_sched_work
, HZ
);
4657 unaccount_event_cpu(event
, event
->cpu
);
4659 unaccount_pmu_sb_event(event
);
4662 static void perf_sched_delayed(struct work_struct
*work
)
4664 mutex_lock(&perf_sched_mutex
);
4665 if (atomic_dec_and_test(&perf_sched_count
))
4666 static_branch_disable(&perf_sched_events
);
4667 mutex_unlock(&perf_sched_mutex
);
4671 * The following implement mutual exclusion of events on "exclusive" pmus
4672 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4673 * at a time, so we disallow creating events that might conflict, namely:
4675 * 1) cpu-wide events in the presence of per-task events,
4676 * 2) per-task events in the presence of cpu-wide events,
4677 * 3) two matching events on the same context.
4679 * The former two cases are handled in the allocation path (perf_event_alloc(),
4680 * _free_event()), the latter -- before the first perf_install_in_context().
4682 static int exclusive_event_init(struct perf_event
*event
)
4684 struct pmu
*pmu
= event
->pmu
;
4686 if (!is_exclusive_pmu(pmu
))
4690 * Prevent co-existence of per-task and cpu-wide events on the
4691 * same exclusive pmu.
4693 * Negative pmu::exclusive_cnt means there are cpu-wide
4694 * events on this "exclusive" pmu, positive means there are
4697 * Since this is called in perf_event_alloc() path, event::ctx
4698 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4699 * to mean "per-task event", because unlike other attach states it
4700 * never gets cleared.
4702 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4703 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4706 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4713 static void exclusive_event_destroy(struct perf_event
*event
)
4715 struct pmu
*pmu
= event
->pmu
;
4717 if (!is_exclusive_pmu(pmu
))
4720 /* see comment in exclusive_event_init() */
4721 if (event
->attach_state
& PERF_ATTACH_TASK
)
4722 atomic_dec(&pmu
->exclusive_cnt
);
4724 atomic_inc(&pmu
->exclusive_cnt
);
4727 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4729 if ((e1
->pmu
== e2
->pmu
) &&
4730 (e1
->cpu
== e2
->cpu
||
4737 static bool exclusive_event_installable(struct perf_event
*event
,
4738 struct perf_event_context
*ctx
)
4740 struct perf_event
*iter_event
;
4741 struct pmu
*pmu
= event
->pmu
;
4743 lockdep_assert_held(&ctx
->mutex
);
4745 if (!is_exclusive_pmu(pmu
))
4748 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4749 if (exclusive_event_match(iter_event
, event
))
4756 static void perf_addr_filters_splice(struct perf_event
*event
,
4757 struct list_head
*head
);
4759 static void _free_event(struct perf_event
*event
)
4761 irq_work_sync(&event
->pending
);
4763 unaccount_event(event
);
4765 security_perf_event_free(event
);
4769 * Can happen when we close an event with re-directed output.
4771 * Since we have a 0 refcount, perf_mmap_close() will skip
4772 * over us; possibly making our ring_buffer_put() the last.
4774 mutex_lock(&event
->mmap_mutex
);
4775 ring_buffer_attach(event
, NULL
);
4776 mutex_unlock(&event
->mmap_mutex
);
4779 if (is_cgroup_event(event
))
4780 perf_detach_cgroup(event
);
4782 if (!event
->parent
) {
4783 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4784 put_callchain_buffers();
4787 perf_event_free_bpf_prog(event
);
4788 perf_addr_filters_splice(event
, NULL
);
4789 kfree(event
->addr_filter_ranges
);
4792 event
->destroy(event
);
4795 * Must be after ->destroy(), due to uprobe_perf_close() using
4798 if (event
->hw
.target
)
4799 put_task_struct(event
->hw
.target
);
4802 * perf_event_free_task() relies on put_ctx() being 'last', in particular
4803 * all task references must be cleaned up.
4806 put_ctx(event
->ctx
);
4808 exclusive_event_destroy(event
);
4809 module_put(event
->pmu
->module
);
4811 call_rcu(&event
->rcu_head
, free_event_rcu
);
4815 * Used to free events which have a known refcount of 1, such as in error paths
4816 * where the event isn't exposed yet and inherited events.
4818 static void free_event(struct perf_event
*event
)
4820 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4821 "unexpected event refcount: %ld; ptr=%p\n",
4822 atomic_long_read(&event
->refcount
), event
)) {
4823 /* leak to avoid use-after-free */
4831 * Remove user event from the owner task.
4833 static void perf_remove_from_owner(struct perf_event
*event
)
4835 struct task_struct
*owner
;
4839 * Matches the smp_store_release() in perf_event_exit_task(). If we
4840 * observe !owner it means the list deletion is complete and we can
4841 * indeed free this event, otherwise we need to serialize on
4842 * owner->perf_event_mutex.
4844 owner
= READ_ONCE(event
->owner
);
4847 * Since delayed_put_task_struct() also drops the last
4848 * task reference we can safely take a new reference
4849 * while holding the rcu_read_lock().
4851 get_task_struct(owner
);
4857 * If we're here through perf_event_exit_task() we're already
4858 * holding ctx->mutex which would be an inversion wrt. the
4859 * normal lock order.
4861 * However we can safely take this lock because its the child
4864 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4867 * We have to re-check the event->owner field, if it is cleared
4868 * we raced with perf_event_exit_task(), acquiring the mutex
4869 * ensured they're done, and we can proceed with freeing the
4873 list_del_init(&event
->owner_entry
);
4874 smp_store_release(&event
->owner
, NULL
);
4876 mutex_unlock(&owner
->perf_event_mutex
);
4877 put_task_struct(owner
);
4881 static void put_event(struct perf_event
*event
)
4883 if (!atomic_long_dec_and_test(&event
->refcount
))
4890 * Kill an event dead; while event:refcount will preserve the event
4891 * object, it will not preserve its functionality. Once the last 'user'
4892 * gives up the object, we'll destroy the thing.
4894 int perf_event_release_kernel(struct perf_event
*event
)
4896 struct perf_event_context
*ctx
= event
->ctx
;
4897 struct perf_event
*child
, *tmp
;
4898 LIST_HEAD(free_list
);
4901 * If we got here through err_file: fput(event_file); we will not have
4902 * attached to a context yet.
4905 WARN_ON_ONCE(event
->attach_state
&
4906 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4910 if (!is_kernel_event(event
))
4911 perf_remove_from_owner(event
);
4913 ctx
= perf_event_ctx_lock(event
);
4914 WARN_ON_ONCE(ctx
->parent_ctx
);
4915 perf_remove_from_context(event
, DETACH_GROUP
);
4917 raw_spin_lock_irq(&ctx
->lock
);
4919 * Mark this event as STATE_DEAD, there is no external reference to it
4922 * Anybody acquiring event->child_mutex after the below loop _must_
4923 * also see this, most importantly inherit_event() which will avoid
4924 * placing more children on the list.
4926 * Thus this guarantees that we will in fact observe and kill _ALL_
4929 event
->state
= PERF_EVENT_STATE_DEAD
;
4930 raw_spin_unlock_irq(&ctx
->lock
);
4932 perf_event_ctx_unlock(event
, ctx
);
4935 mutex_lock(&event
->child_mutex
);
4936 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4939 * Cannot change, child events are not migrated, see the
4940 * comment with perf_event_ctx_lock_nested().
4942 ctx
= READ_ONCE(child
->ctx
);
4944 * Since child_mutex nests inside ctx::mutex, we must jump
4945 * through hoops. We start by grabbing a reference on the ctx.
4947 * Since the event cannot get freed while we hold the
4948 * child_mutex, the context must also exist and have a !0
4954 * Now that we have a ctx ref, we can drop child_mutex, and
4955 * acquire ctx::mutex without fear of it going away. Then we
4956 * can re-acquire child_mutex.
4958 mutex_unlock(&event
->child_mutex
);
4959 mutex_lock(&ctx
->mutex
);
4960 mutex_lock(&event
->child_mutex
);
4963 * Now that we hold ctx::mutex and child_mutex, revalidate our
4964 * state, if child is still the first entry, it didn't get freed
4965 * and we can continue doing so.
4967 tmp
= list_first_entry_or_null(&event
->child_list
,
4968 struct perf_event
, child_list
);
4970 perf_remove_from_context(child
, DETACH_GROUP
);
4971 list_move(&child
->child_list
, &free_list
);
4973 * This matches the refcount bump in inherit_event();
4974 * this can't be the last reference.
4979 mutex_unlock(&event
->child_mutex
);
4980 mutex_unlock(&ctx
->mutex
);
4984 mutex_unlock(&event
->child_mutex
);
4986 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4987 void *var
= &child
->ctx
->refcount
;
4989 list_del(&child
->child_list
);
4993 * Wake any perf_event_free_task() waiting for this event to be
4996 smp_mb(); /* pairs with wait_var_event() */
5001 put_event(event
); /* Must be the 'last' reference */
5004 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
5007 * Called when the last reference to the file is gone.
5009 static int perf_release(struct inode
*inode
, struct file
*file
)
5011 perf_event_release_kernel(file
->private_data
);
5015 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
5017 struct perf_event
*child
;
5023 mutex_lock(&event
->child_mutex
);
5025 (void)perf_event_read(event
, false);
5026 total
+= perf_event_count(event
);
5028 *enabled
+= event
->total_time_enabled
+
5029 atomic64_read(&event
->child_total_time_enabled
);
5030 *running
+= event
->total_time_running
+
5031 atomic64_read(&event
->child_total_time_running
);
5033 list_for_each_entry(child
, &event
->child_list
, child_list
) {
5034 (void)perf_event_read(child
, false);
5035 total
+= perf_event_count(child
);
5036 *enabled
+= child
->total_time_enabled
;
5037 *running
+= child
->total_time_running
;
5039 mutex_unlock(&event
->child_mutex
);
5044 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
5046 struct perf_event_context
*ctx
;
5049 ctx
= perf_event_ctx_lock(event
);
5050 count
= __perf_event_read_value(event
, enabled
, running
);
5051 perf_event_ctx_unlock(event
, ctx
);
5055 EXPORT_SYMBOL_GPL(perf_event_read_value
);
5057 static int __perf_read_group_add(struct perf_event
*leader
,
5058 u64 read_format
, u64
*values
)
5060 struct perf_event_context
*ctx
= leader
->ctx
;
5061 struct perf_event
*sub
;
5062 unsigned long flags
;
5063 int n
= 1; /* skip @nr */
5066 ret
= perf_event_read(leader
, true);
5070 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
5073 * Since we co-schedule groups, {enabled,running} times of siblings
5074 * will be identical to those of the leader, so we only publish one
5077 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5078 values
[n
++] += leader
->total_time_enabled
+
5079 atomic64_read(&leader
->child_total_time_enabled
);
5082 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5083 values
[n
++] += leader
->total_time_running
+
5084 atomic64_read(&leader
->child_total_time_running
);
5088 * Write {count,id} tuples for every sibling.
5090 values
[n
++] += perf_event_count(leader
);
5091 if (read_format
& PERF_FORMAT_ID
)
5092 values
[n
++] = primary_event_id(leader
);
5094 for_each_sibling_event(sub
, leader
) {
5095 values
[n
++] += perf_event_count(sub
);
5096 if (read_format
& PERF_FORMAT_ID
)
5097 values
[n
++] = primary_event_id(sub
);
5100 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
5104 static int perf_read_group(struct perf_event
*event
,
5105 u64 read_format
, char __user
*buf
)
5107 struct perf_event
*leader
= event
->group_leader
, *child
;
5108 struct perf_event_context
*ctx
= leader
->ctx
;
5112 lockdep_assert_held(&ctx
->mutex
);
5114 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
5118 values
[0] = 1 + leader
->nr_siblings
;
5121 * By locking the child_mutex of the leader we effectively
5122 * lock the child list of all siblings.. XXX explain how.
5124 mutex_lock(&leader
->child_mutex
);
5126 ret
= __perf_read_group_add(leader
, read_format
, values
);
5130 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
5131 ret
= __perf_read_group_add(child
, read_format
, values
);
5136 mutex_unlock(&leader
->child_mutex
);
5138 ret
= event
->read_size
;
5139 if (copy_to_user(buf
, values
, event
->read_size
))
5144 mutex_unlock(&leader
->child_mutex
);
5150 static int perf_read_one(struct perf_event
*event
,
5151 u64 read_format
, char __user
*buf
)
5153 u64 enabled
, running
;
5157 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
5158 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5159 values
[n
++] = enabled
;
5160 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5161 values
[n
++] = running
;
5162 if (read_format
& PERF_FORMAT_ID
)
5163 values
[n
++] = primary_event_id(event
);
5165 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
5168 return n
* sizeof(u64
);
5171 static bool is_event_hup(struct perf_event
*event
)
5175 if (event
->state
> PERF_EVENT_STATE_EXIT
)
5178 mutex_lock(&event
->child_mutex
);
5179 no_children
= list_empty(&event
->child_list
);
5180 mutex_unlock(&event
->child_mutex
);
5185 * Read the performance event - simple non blocking version for now
5188 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
5190 u64 read_format
= event
->attr
.read_format
;
5194 * Return end-of-file for a read on an event that is in
5195 * error state (i.e. because it was pinned but it couldn't be
5196 * scheduled on to the CPU at some point).
5198 if (event
->state
== PERF_EVENT_STATE_ERROR
)
5201 if (count
< event
->read_size
)
5204 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5205 if (read_format
& PERF_FORMAT_GROUP
)
5206 ret
= perf_read_group(event
, read_format
, buf
);
5208 ret
= perf_read_one(event
, read_format
, buf
);
5214 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
5216 struct perf_event
*event
= file
->private_data
;
5217 struct perf_event_context
*ctx
;
5220 ret
= security_perf_event_read(event
);
5224 ctx
= perf_event_ctx_lock(event
);
5225 ret
= __perf_read(event
, buf
, count
);
5226 perf_event_ctx_unlock(event
, ctx
);
5231 static __poll_t
perf_poll(struct file
*file
, poll_table
*wait
)
5233 struct perf_event
*event
= file
->private_data
;
5234 struct perf_buffer
*rb
;
5235 __poll_t events
= EPOLLHUP
;
5237 poll_wait(file
, &event
->waitq
, wait
);
5239 if (is_event_hup(event
))
5243 * Pin the event->rb by taking event->mmap_mutex; otherwise
5244 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
5246 mutex_lock(&event
->mmap_mutex
);
5249 events
= atomic_xchg(&rb
->poll
, 0);
5250 mutex_unlock(&event
->mmap_mutex
);
5254 static void _perf_event_reset(struct perf_event
*event
)
5256 (void)perf_event_read(event
, false);
5257 local64_set(&event
->count
, 0);
5258 perf_event_update_userpage(event
);
5261 /* Assume it's not an event with inherit set. */
5262 u64
perf_event_pause(struct perf_event
*event
, bool reset
)
5264 struct perf_event_context
*ctx
;
5267 ctx
= perf_event_ctx_lock(event
);
5268 WARN_ON_ONCE(event
->attr
.inherit
);
5269 _perf_event_disable(event
);
5270 count
= local64_read(&event
->count
);
5272 local64_set(&event
->count
, 0);
5273 perf_event_ctx_unlock(event
, ctx
);
5277 EXPORT_SYMBOL_GPL(perf_event_pause
);
5280 * Holding the top-level event's child_mutex means that any
5281 * descendant process that has inherited this event will block
5282 * in perf_event_exit_event() if it goes to exit, thus satisfying the
5283 * task existence requirements of perf_event_enable/disable.
5285 static void perf_event_for_each_child(struct perf_event
*event
,
5286 void (*func
)(struct perf_event
*))
5288 struct perf_event
*child
;
5290 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5292 mutex_lock(&event
->child_mutex
);
5294 list_for_each_entry(child
, &event
->child_list
, child_list
)
5296 mutex_unlock(&event
->child_mutex
);
5299 static void perf_event_for_each(struct perf_event
*event
,
5300 void (*func
)(struct perf_event
*))
5302 struct perf_event_context
*ctx
= event
->ctx
;
5303 struct perf_event
*sibling
;
5305 lockdep_assert_held(&ctx
->mutex
);
5307 event
= event
->group_leader
;
5309 perf_event_for_each_child(event
, func
);
5310 for_each_sibling_event(sibling
, event
)
5311 perf_event_for_each_child(sibling
, func
);
5314 static void __perf_event_period(struct perf_event
*event
,
5315 struct perf_cpu_context
*cpuctx
,
5316 struct perf_event_context
*ctx
,
5319 u64 value
= *((u64
*)info
);
5322 if (event
->attr
.freq
) {
5323 event
->attr
.sample_freq
= value
;
5325 event
->attr
.sample_period
= value
;
5326 event
->hw
.sample_period
= value
;
5329 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
5331 perf_pmu_disable(ctx
->pmu
);
5333 * We could be throttled; unthrottle now to avoid the tick
5334 * trying to unthrottle while we already re-started the event.
5336 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
5337 event
->hw
.interrupts
= 0;
5338 perf_log_throttle(event
, 1);
5340 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
5343 local64_set(&event
->hw
.period_left
, 0);
5346 event
->pmu
->start(event
, PERF_EF_RELOAD
);
5347 perf_pmu_enable(ctx
->pmu
);
5351 static int perf_event_check_period(struct perf_event
*event
, u64 value
)
5353 return event
->pmu
->check_period(event
, value
);
5356 static int _perf_event_period(struct perf_event
*event
, u64 value
)
5358 if (!is_sampling_event(event
))
5364 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
5367 if (perf_event_check_period(event
, value
))
5370 if (!event
->attr
.freq
&& (value
& (1ULL << 63)))
5373 event_function_call(event
, __perf_event_period
, &value
);
5378 int perf_event_period(struct perf_event
*event
, u64 value
)
5380 struct perf_event_context
*ctx
;
5383 ctx
= perf_event_ctx_lock(event
);
5384 ret
= _perf_event_period(event
, value
);
5385 perf_event_ctx_unlock(event
, ctx
);
5389 EXPORT_SYMBOL_GPL(perf_event_period
);
5391 static const struct file_operations perf_fops
;
5393 static inline int perf_fget_light(int fd
, struct fd
*p
)
5395 struct fd f
= fdget(fd
);
5399 if (f
.file
->f_op
!= &perf_fops
) {
5407 static int perf_event_set_output(struct perf_event
*event
,
5408 struct perf_event
*output_event
);
5409 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
5410 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
5411 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5412 struct perf_event_attr
*attr
);
5414 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
5416 void (*func
)(struct perf_event
*);
5420 case PERF_EVENT_IOC_ENABLE
:
5421 func
= _perf_event_enable
;
5423 case PERF_EVENT_IOC_DISABLE
:
5424 func
= _perf_event_disable
;
5426 case PERF_EVENT_IOC_RESET
:
5427 func
= _perf_event_reset
;
5430 case PERF_EVENT_IOC_REFRESH
:
5431 return _perf_event_refresh(event
, arg
);
5433 case PERF_EVENT_IOC_PERIOD
:
5437 if (copy_from_user(&value
, (u64 __user
*)arg
, sizeof(value
)))
5440 return _perf_event_period(event
, value
);
5442 case PERF_EVENT_IOC_ID
:
5444 u64 id
= primary_event_id(event
);
5446 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
5451 case PERF_EVENT_IOC_SET_OUTPUT
:
5455 struct perf_event
*output_event
;
5457 ret
= perf_fget_light(arg
, &output
);
5460 output_event
= output
.file
->private_data
;
5461 ret
= perf_event_set_output(event
, output_event
);
5464 ret
= perf_event_set_output(event
, NULL
);
5469 case PERF_EVENT_IOC_SET_FILTER
:
5470 return perf_event_set_filter(event
, (void __user
*)arg
);
5472 case PERF_EVENT_IOC_SET_BPF
:
5473 return perf_event_set_bpf_prog(event
, arg
);
5475 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
5476 struct perf_buffer
*rb
;
5479 rb
= rcu_dereference(event
->rb
);
5480 if (!rb
|| !rb
->nr_pages
) {
5484 rb_toggle_paused(rb
, !!arg
);
5489 case PERF_EVENT_IOC_QUERY_BPF
:
5490 return perf_event_query_prog_array(event
, (void __user
*)arg
);
5492 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES
: {
5493 struct perf_event_attr new_attr
;
5494 int err
= perf_copy_attr((struct perf_event_attr __user
*)arg
,
5500 return perf_event_modify_attr(event
, &new_attr
);
5506 if (flags
& PERF_IOC_FLAG_GROUP
)
5507 perf_event_for_each(event
, func
);
5509 perf_event_for_each_child(event
, func
);
5514 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
5516 struct perf_event
*event
= file
->private_data
;
5517 struct perf_event_context
*ctx
;
5520 /* Treat ioctl like writes as it is likely a mutating operation. */
5521 ret
= security_perf_event_write(event
);
5525 ctx
= perf_event_ctx_lock(event
);
5526 ret
= _perf_ioctl(event
, cmd
, arg
);
5527 perf_event_ctx_unlock(event
, ctx
);
5532 #ifdef CONFIG_COMPAT
5533 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
5536 switch (_IOC_NR(cmd
)) {
5537 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
5538 case _IOC_NR(PERF_EVENT_IOC_ID
):
5539 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF
):
5540 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES
):
5541 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5542 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
5543 cmd
&= ~IOCSIZE_MASK
;
5544 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
5548 return perf_ioctl(file
, cmd
, arg
);
5551 # define perf_compat_ioctl NULL
5554 int perf_event_task_enable(void)
5556 struct perf_event_context
*ctx
;
5557 struct perf_event
*event
;
5559 mutex_lock(¤t
->perf_event_mutex
);
5560 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5561 ctx
= perf_event_ctx_lock(event
);
5562 perf_event_for_each_child(event
, _perf_event_enable
);
5563 perf_event_ctx_unlock(event
, ctx
);
5565 mutex_unlock(¤t
->perf_event_mutex
);
5570 int perf_event_task_disable(void)
5572 struct perf_event_context
*ctx
;
5573 struct perf_event
*event
;
5575 mutex_lock(¤t
->perf_event_mutex
);
5576 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5577 ctx
= perf_event_ctx_lock(event
);
5578 perf_event_for_each_child(event
, _perf_event_disable
);
5579 perf_event_ctx_unlock(event
, ctx
);
5581 mutex_unlock(¤t
->perf_event_mutex
);
5586 static int perf_event_index(struct perf_event
*event
)
5588 if (event
->hw
.state
& PERF_HES_STOPPED
)
5591 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5594 return event
->pmu
->event_idx(event
);
5597 static void calc_timer_values(struct perf_event
*event
,
5604 *now
= perf_clock();
5605 ctx_time
= event
->shadow_ctx_time
+ *now
;
5606 __perf_update_times(event
, ctx_time
, enabled
, running
);
5609 static void perf_event_init_userpage(struct perf_event
*event
)
5611 struct perf_event_mmap_page
*userpg
;
5612 struct perf_buffer
*rb
;
5615 rb
= rcu_dereference(event
->rb
);
5619 userpg
= rb
->user_page
;
5621 /* Allow new userspace to detect that bit 0 is deprecated */
5622 userpg
->cap_bit0_is_deprecated
= 1;
5623 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
5624 userpg
->data_offset
= PAGE_SIZE
;
5625 userpg
->data_size
= perf_data_size(rb
);
5631 void __weak
arch_perf_update_userpage(
5632 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
5637 * Callers need to ensure there can be no nesting of this function, otherwise
5638 * the seqlock logic goes bad. We can not serialize this because the arch
5639 * code calls this from NMI context.
5641 void perf_event_update_userpage(struct perf_event
*event
)
5643 struct perf_event_mmap_page
*userpg
;
5644 struct perf_buffer
*rb
;
5645 u64 enabled
, running
, now
;
5648 rb
= rcu_dereference(event
->rb
);
5653 * compute total_time_enabled, total_time_running
5654 * based on snapshot values taken when the event
5655 * was last scheduled in.
5657 * we cannot simply called update_context_time()
5658 * because of locking issue as we can be called in
5661 calc_timer_values(event
, &now
, &enabled
, &running
);
5663 userpg
= rb
->user_page
;
5665 * Disable preemption to guarantee consistent time stamps are stored to
5671 userpg
->index
= perf_event_index(event
);
5672 userpg
->offset
= perf_event_count(event
);
5674 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5676 userpg
->time_enabled
= enabled
+
5677 atomic64_read(&event
->child_total_time_enabled
);
5679 userpg
->time_running
= running
+
5680 atomic64_read(&event
->child_total_time_running
);
5682 arch_perf_update_userpage(event
, userpg
, now
);
5690 EXPORT_SYMBOL_GPL(perf_event_update_userpage
);
5692 static vm_fault_t
perf_mmap_fault(struct vm_fault
*vmf
)
5694 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5695 struct perf_buffer
*rb
;
5696 vm_fault_t ret
= VM_FAULT_SIGBUS
;
5698 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5699 if (vmf
->pgoff
== 0)
5705 rb
= rcu_dereference(event
->rb
);
5709 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5712 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5716 get_page(vmf
->page
);
5717 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5718 vmf
->page
->index
= vmf
->pgoff
;
5727 static void ring_buffer_attach(struct perf_event
*event
,
5728 struct perf_buffer
*rb
)
5730 struct perf_buffer
*old_rb
= NULL
;
5731 unsigned long flags
;
5735 * Should be impossible, we set this when removing
5736 * event->rb_entry and wait/clear when adding event->rb_entry.
5738 WARN_ON_ONCE(event
->rcu_pending
);
5741 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5742 list_del_rcu(&event
->rb_entry
);
5743 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5745 event
->rcu_batches
= get_state_synchronize_rcu();
5746 event
->rcu_pending
= 1;
5750 if (event
->rcu_pending
) {
5751 cond_synchronize_rcu(event
->rcu_batches
);
5752 event
->rcu_pending
= 0;
5755 spin_lock_irqsave(&rb
->event_lock
, flags
);
5756 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5757 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5761 * Avoid racing with perf_mmap_close(AUX): stop the event
5762 * before swizzling the event::rb pointer; if it's getting
5763 * unmapped, its aux_mmap_count will be 0 and it won't
5764 * restart. See the comment in __perf_pmu_output_stop().
5766 * Data will inevitably be lost when set_output is done in
5767 * mid-air, but then again, whoever does it like this is
5768 * not in for the data anyway.
5771 perf_event_stop(event
, 0);
5773 rcu_assign_pointer(event
->rb
, rb
);
5776 ring_buffer_put(old_rb
);
5778 * Since we detached before setting the new rb, so that we
5779 * could attach the new rb, we could have missed a wakeup.
5782 wake_up_all(&event
->waitq
);
5786 static void ring_buffer_wakeup(struct perf_event
*event
)
5788 struct perf_buffer
*rb
;
5791 rb
= rcu_dereference(event
->rb
);
5793 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5794 wake_up_all(&event
->waitq
);
5799 struct perf_buffer
*ring_buffer_get(struct perf_event
*event
)
5801 struct perf_buffer
*rb
;
5804 rb
= rcu_dereference(event
->rb
);
5806 if (!refcount_inc_not_zero(&rb
->refcount
))
5814 void ring_buffer_put(struct perf_buffer
*rb
)
5816 if (!refcount_dec_and_test(&rb
->refcount
))
5819 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5821 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5824 static void perf_mmap_open(struct vm_area_struct
*vma
)
5826 struct perf_event
*event
= vma
->vm_file
->private_data
;
5828 atomic_inc(&event
->mmap_count
);
5829 atomic_inc(&event
->rb
->mmap_count
);
5832 atomic_inc(&event
->rb
->aux_mmap_count
);
5834 if (event
->pmu
->event_mapped
)
5835 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5838 static void perf_pmu_output_stop(struct perf_event
*event
);
5841 * A buffer can be mmap()ed multiple times; either directly through the same
5842 * event, or through other events by use of perf_event_set_output().
5844 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5845 * the buffer here, where we still have a VM context. This means we need
5846 * to detach all events redirecting to us.
5848 static void perf_mmap_close(struct vm_area_struct
*vma
)
5850 struct perf_event
*event
= vma
->vm_file
->private_data
;
5852 struct perf_buffer
*rb
= ring_buffer_get(event
);
5853 struct user_struct
*mmap_user
= rb
->mmap_user
;
5854 int mmap_locked
= rb
->mmap_locked
;
5855 unsigned long size
= perf_data_size(rb
);
5857 if (event
->pmu
->event_unmapped
)
5858 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5861 * rb->aux_mmap_count will always drop before rb->mmap_count and
5862 * event->mmap_count, so it is ok to use event->mmap_mutex to
5863 * serialize with perf_mmap here.
5865 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5866 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5868 * Stop all AUX events that are writing to this buffer,
5869 * so that we can free its AUX pages and corresponding PMU
5870 * data. Note that after rb::aux_mmap_count dropped to zero,
5871 * they won't start any more (see perf_aux_output_begin()).
5873 perf_pmu_output_stop(event
);
5875 /* now it's safe to free the pages */
5876 atomic_long_sub(rb
->aux_nr_pages
- rb
->aux_mmap_locked
, &mmap_user
->locked_vm
);
5877 atomic64_sub(rb
->aux_mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5879 /* this has to be the last one */
5881 WARN_ON_ONCE(refcount_read(&rb
->aux_refcount
));
5883 mutex_unlock(&event
->mmap_mutex
);
5886 atomic_dec(&rb
->mmap_count
);
5888 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5891 ring_buffer_attach(event
, NULL
);
5892 mutex_unlock(&event
->mmap_mutex
);
5894 /* If there's still other mmap()s of this buffer, we're done. */
5895 if (atomic_read(&rb
->mmap_count
))
5899 * No other mmap()s, detach from all other events that might redirect
5900 * into the now unreachable buffer. Somewhat complicated by the
5901 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5905 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5906 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5908 * This event is en-route to free_event() which will
5909 * detach it and remove it from the list.
5915 mutex_lock(&event
->mmap_mutex
);
5917 * Check we didn't race with perf_event_set_output() which can
5918 * swizzle the rb from under us while we were waiting to
5919 * acquire mmap_mutex.
5921 * If we find a different rb; ignore this event, a next
5922 * iteration will no longer find it on the list. We have to
5923 * still restart the iteration to make sure we're not now
5924 * iterating the wrong list.
5926 if (event
->rb
== rb
)
5927 ring_buffer_attach(event
, NULL
);
5929 mutex_unlock(&event
->mmap_mutex
);
5933 * Restart the iteration; either we're on the wrong list or
5934 * destroyed its integrity by doing a deletion.
5941 * It could be there's still a few 0-ref events on the list; they'll
5942 * get cleaned up by free_event() -- they'll also still have their
5943 * ref on the rb and will free it whenever they are done with it.
5945 * Aside from that, this buffer is 'fully' detached and unmapped,
5946 * undo the VM accounting.
5949 atomic_long_sub((size
>> PAGE_SHIFT
) + 1 - mmap_locked
,
5950 &mmap_user
->locked_vm
);
5951 atomic64_sub(mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5952 free_uid(mmap_user
);
5955 ring_buffer_put(rb
); /* could be last */
5958 static const struct vm_operations_struct perf_mmap_vmops
= {
5959 .open
= perf_mmap_open
,
5960 .close
= perf_mmap_close
, /* non mergeable */
5961 .fault
= perf_mmap_fault
,
5962 .page_mkwrite
= perf_mmap_fault
,
5965 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5967 struct perf_event
*event
= file
->private_data
;
5968 unsigned long user_locked
, user_lock_limit
;
5969 struct user_struct
*user
= current_user();
5970 struct perf_buffer
*rb
= NULL
;
5971 unsigned long locked
, lock_limit
;
5972 unsigned long vma_size
;
5973 unsigned long nr_pages
;
5974 long user_extra
= 0, extra
= 0;
5975 int ret
= 0, flags
= 0;
5978 * Don't allow mmap() of inherited per-task counters. This would
5979 * create a performance issue due to all children writing to the
5982 if (event
->cpu
== -1 && event
->attr
.inherit
)
5985 if (!(vma
->vm_flags
& VM_SHARED
))
5988 ret
= security_perf_event_read(event
);
5992 vma_size
= vma
->vm_end
- vma
->vm_start
;
5994 if (vma
->vm_pgoff
== 0) {
5995 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5998 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5999 * mapped, all subsequent mappings should have the same size
6000 * and offset. Must be above the normal perf buffer.
6002 u64 aux_offset
, aux_size
;
6007 nr_pages
= vma_size
/ PAGE_SIZE
;
6009 mutex_lock(&event
->mmap_mutex
);
6016 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
6017 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
6019 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
6022 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
6025 /* already mapped with a different offset */
6026 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
6029 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
6032 /* already mapped with a different size */
6033 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
6036 if (!is_power_of_2(nr_pages
))
6039 if (!atomic_inc_not_zero(&rb
->mmap_count
))
6042 if (rb_has_aux(rb
)) {
6043 atomic_inc(&rb
->aux_mmap_count
);
6048 atomic_set(&rb
->aux_mmap_count
, 1);
6049 user_extra
= nr_pages
;
6055 * If we have rb pages ensure they're a power-of-two number, so we
6056 * can do bitmasks instead of modulo.
6058 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
6061 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
6064 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
6066 mutex_lock(&event
->mmap_mutex
);
6068 if (event
->rb
->nr_pages
!= nr_pages
) {
6073 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
6075 * Raced against perf_mmap_close() through
6076 * perf_event_set_output(). Try again, hope for better
6079 mutex_unlock(&event
->mmap_mutex
);
6086 user_extra
= nr_pages
+ 1;
6089 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
6092 * Increase the limit linearly with more CPUs:
6094 user_lock_limit
*= num_online_cpus();
6096 user_locked
= atomic_long_read(&user
->locked_vm
);
6099 * sysctl_perf_event_mlock may have changed, so that
6100 * user->locked_vm > user_lock_limit
6102 if (user_locked
> user_lock_limit
)
6103 user_locked
= user_lock_limit
;
6104 user_locked
+= user_extra
;
6106 if (user_locked
> user_lock_limit
) {
6108 * charge locked_vm until it hits user_lock_limit;
6109 * charge the rest from pinned_vm
6111 extra
= user_locked
- user_lock_limit
;
6112 user_extra
-= extra
;
6115 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
6116 lock_limit
>>= PAGE_SHIFT
;
6117 locked
= atomic64_read(&vma
->vm_mm
->pinned_vm
) + extra
;
6119 if ((locked
> lock_limit
) && perf_is_paranoid() &&
6120 !capable(CAP_IPC_LOCK
)) {
6125 WARN_ON(!rb
&& event
->rb
);
6127 if (vma
->vm_flags
& VM_WRITE
)
6128 flags
|= RING_BUFFER_WRITABLE
;
6131 rb
= rb_alloc(nr_pages
,
6132 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
6140 atomic_set(&rb
->mmap_count
, 1);
6141 rb
->mmap_user
= get_current_user();
6142 rb
->mmap_locked
= extra
;
6144 ring_buffer_attach(event
, rb
);
6146 perf_event_init_userpage(event
);
6147 perf_event_update_userpage(event
);
6149 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
6150 event
->attr
.aux_watermark
, flags
);
6152 rb
->aux_mmap_locked
= extra
;
6157 atomic_long_add(user_extra
, &user
->locked_vm
);
6158 atomic64_add(extra
, &vma
->vm_mm
->pinned_vm
);
6160 atomic_inc(&event
->mmap_count
);
6162 atomic_dec(&rb
->mmap_count
);
6165 mutex_unlock(&event
->mmap_mutex
);
6168 * Since pinned accounting is per vm we cannot allow fork() to copy our
6171 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
6172 vma
->vm_ops
= &perf_mmap_vmops
;
6174 if (event
->pmu
->event_mapped
)
6175 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
6180 static int perf_fasync(int fd
, struct file
*filp
, int on
)
6182 struct inode
*inode
= file_inode(filp
);
6183 struct perf_event
*event
= filp
->private_data
;
6187 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
6188 inode_unlock(inode
);
6196 static const struct file_operations perf_fops
= {
6197 .llseek
= no_llseek
,
6198 .release
= perf_release
,
6201 .unlocked_ioctl
= perf_ioctl
,
6202 .compat_ioctl
= perf_compat_ioctl
,
6204 .fasync
= perf_fasync
,
6210 * If there's data, ensure we set the poll() state and publish everything
6211 * to user-space before waking everybody up.
6214 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
6216 /* only the parent has fasync state */
6218 event
= event
->parent
;
6219 return &event
->fasync
;
6222 void perf_event_wakeup(struct perf_event
*event
)
6224 ring_buffer_wakeup(event
);
6226 if (event
->pending_kill
) {
6227 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
6228 event
->pending_kill
= 0;
6232 static void perf_pending_event_disable(struct perf_event
*event
)
6234 int cpu
= READ_ONCE(event
->pending_disable
);
6239 if (cpu
== smp_processor_id()) {
6240 WRITE_ONCE(event
->pending_disable
, -1);
6241 perf_event_disable_local(event
);
6248 * perf_event_disable_inatomic()
6249 * @pending_disable = CPU-A;
6253 * @pending_disable = -1;
6256 * perf_event_disable_inatomic()
6257 * @pending_disable = CPU-B;
6258 * irq_work_queue(); // FAILS
6261 * perf_pending_event()
6263 * But the event runs on CPU-B and wants disabling there.
6265 irq_work_queue_on(&event
->pending
, cpu
);
6268 static void perf_pending_event(struct irq_work
*entry
)
6270 struct perf_event
*event
= container_of(entry
, struct perf_event
, pending
);
6273 rctx
= perf_swevent_get_recursion_context();
6275 * If we 'fail' here, that's OK, it means recursion is already disabled
6276 * and we won't recurse 'further'.
6279 perf_pending_event_disable(event
);
6281 if (event
->pending_wakeup
) {
6282 event
->pending_wakeup
= 0;
6283 perf_event_wakeup(event
);
6287 perf_swevent_put_recursion_context(rctx
);
6291 * We assume there is only KVM supporting the callbacks.
6292 * Later on, we might change it to a list if there is
6293 * another virtualization implementation supporting the callbacks.
6295 struct perf_guest_info_callbacks
*perf_guest_cbs
;
6297 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6299 perf_guest_cbs
= cbs
;
6302 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
6304 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6306 perf_guest_cbs
= NULL
;
6309 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
6312 perf_output_sample_regs(struct perf_output_handle
*handle
,
6313 struct pt_regs
*regs
, u64 mask
)
6316 DECLARE_BITMAP(_mask
, 64);
6318 bitmap_from_u64(_mask
, mask
);
6319 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
6322 val
= perf_reg_value(regs
, bit
);
6323 perf_output_put(handle
, val
);
6327 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
6328 struct pt_regs
*regs
,
6329 struct pt_regs
*regs_user_copy
)
6331 if (user_mode(regs
)) {
6332 regs_user
->abi
= perf_reg_abi(current
);
6333 regs_user
->regs
= regs
;
6334 } else if (!(current
->flags
& PF_KTHREAD
)) {
6335 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
6337 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
6338 regs_user
->regs
= NULL
;
6342 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
6343 struct pt_regs
*regs
)
6345 regs_intr
->regs
= regs
;
6346 regs_intr
->abi
= perf_reg_abi(current
);
6351 * Get remaining task size from user stack pointer.
6353 * It'd be better to take stack vma map and limit this more
6354 * precisely, but there's no way to get it safely under interrupt,
6355 * so using TASK_SIZE as limit.
6357 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
6359 unsigned long addr
= perf_user_stack_pointer(regs
);
6361 if (!addr
|| addr
>= TASK_SIZE
)
6364 return TASK_SIZE
- addr
;
6368 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
6369 struct pt_regs
*regs
)
6373 /* No regs, no stack pointer, no dump. */
6378 * Check if we fit in with the requested stack size into the:
6380 * If we don't, we limit the size to the TASK_SIZE.
6382 * - remaining sample size
6383 * If we don't, we customize the stack size to
6384 * fit in to the remaining sample size.
6387 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
6388 stack_size
= min(stack_size
, (u16
) task_size
);
6390 /* Current header size plus static size and dynamic size. */
6391 header_size
+= 2 * sizeof(u64
);
6393 /* Do we fit in with the current stack dump size? */
6394 if ((u16
) (header_size
+ stack_size
) < header_size
) {
6396 * If we overflow the maximum size for the sample,
6397 * we customize the stack dump size to fit in.
6399 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
6400 stack_size
= round_up(stack_size
, sizeof(u64
));
6407 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
6408 struct pt_regs
*regs
)
6410 /* Case of a kernel thread, nothing to dump */
6413 perf_output_put(handle
, size
);
6423 * - the size requested by user or the best one we can fit
6424 * in to the sample max size
6426 * - user stack dump data
6428 * - the actual dumped size
6432 perf_output_put(handle
, dump_size
);
6435 sp
= perf_user_stack_pointer(regs
);
6438 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
6440 dyn_size
= dump_size
- rem
;
6442 perf_output_skip(handle
, rem
);
6445 perf_output_put(handle
, dyn_size
);
6449 static unsigned long perf_prepare_sample_aux(struct perf_event
*event
,
6450 struct perf_sample_data
*data
,
6453 struct perf_event
*sampler
= event
->aux_event
;
6454 struct perf_buffer
*rb
;
6461 if (WARN_ON_ONCE(READ_ONCE(sampler
->state
) != PERF_EVENT_STATE_ACTIVE
))
6464 if (WARN_ON_ONCE(READ_ONCE(sampler
->oncpu
) != smp_processor_id()))
6467 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6472 * If this is an NMI hit inside sampling code, don't take
6473 * the sample. See also perf_aux_sample_output().
6475 if (READ_ONCE(rb
->aux_in_sampling
)) {
6478 size
= min_t(size_t, size
, perf_aux_size(rb
));
6479 data
->aux_size
= ALIGN(size
, sizeof(u64
));
6481 ring_buffer_put(rb
);
6484 return data
->aux_size
;
6487 long perf_pmu_snapshot_aux(struct perf_buffer
*rb
,
6488 struct perf_event
*event
,
6489 struct perf_output_handle
*handle
,
6492 unsigned long flags
;
6496 * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
6497 * paths. If we start calling them in NMI context, they may race with
6498 * the IRQ ones, that is, for example, re-starting an event that's just
6499 * been stopped, which is why we're using a separate callback that
6500 * doesn't change the event state.
6502 * IRQs need to be disabled to prevent IPIs from racing with us.
6504 local_irq_save(flags
);
6506 * Guard against NMI hits inside the critical section;
6507 * see also perf_prepare_sample_aux().
6509 WRITE_ONCE(rb
->aux_in_sampling
, 1);
6512 ret
= event
->pmu
->snapshot_aux(event
, handle
, size
);
6515 WRITE_ONCE(rb
->aux_in_sampling
, 0);
6516 local_irq_restore(flags
);
6521 static void perf_aux_sample_output(struct perf_event
*event
,
6522 struct perf_output_handle
*handle
,
6523 struct perf_sample_data
*data
)
6525 struct perf_event
*sampler
= event
->aux_event
;
6526 struct perf_buffer
*rb
;
6530 if (WARN_ON_ONCE(!sampler
|| !data
->aux_size
))
6533 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6537 size
= perf_pmu_snapshot_aux(rb
, sampler
, handle
, data
->aux_size
);
6540 * An error here means that perf_output_copy() failed (returned a
6541 * non-zero surplus that it didn't copy), which in its current
6542 * enlightened implementation is not possible. If that changes, we'd
6545 if (WARN_ON_ONCE(size
< 0))
6549 * The pad comes from ALIGN()ing data->aux_size up to u64 in
6550 * perf_prepare_sample_aux(), so should not be more than that.
6552 pad
= data
->aux_size
- size
;
6553 if (WARN_ON_ONCE(pad
>= sizeof(u64
)))
6558 perf_output_copy(handle
, &zero
, pad
);
6562 ring_buffer_put(rb
);
6565 static void __perf_event_header__init_id(struct perf_event_header
*header
,
6566 struct perf_sample_data
*data
,
6567 struct perf_event
*event
)
6569 u64 sample_type
= event
->attr
.sample_type
;
6571 data
->type
= sample_type
;
6572 header
->size
+= event
->id_header_size
;
6574 if (sample_type
& PERF_SAMPLE_TID
) {
6575 /* namespace issues */
6576 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
6577 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
6580 if (sample_type
& PERF_SAMPLE_TIME
)
6581 data
->time
= perf_event_clock(event
);
6583 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
6584 data
->id
= primary_event_id(event
);
6586 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6587 data
->stream_id
= event
->id
;
6589 if (sample_type
& PERF_SAMPLE_CPU
) {
6590 data
->cpu_entry
.cpu
= raw_smp_processor_id();
6591 data
->cpu_entry
.reserved
= 0;
6595 void perf_event_header__init_id(struct perf_event_header
*header
,
6596 struct perf_sample_data
*data
,
6597 struct perf_event
*event
)
6599 if (event
->attr
.sample_id_all
)
6600 __perf_event_header__init_id(header
, data
, event
);
6603 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
6604 struct perf_sample_data
*data
)
6606 u64 sample_type
= data
->type
;
6608 if (sample_type
& PERF_SAMPLE_TID
)
6609 perf_output_put(handle
, data
->tid_entry
);
6611 if (sample_type
& PERF_SAMPLE_TIME
)
6612 perf_output_put(handle
, data
->time
);
6614 if (sample_type
& PERF_SAMPLE_ID
)
6615 perf_output_put(handle
, data
->id
);
6617 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6618 perf_output_put(handle
, data
->stream_id
);
6620 if (sample_type
& PERF_SAMPLE_CPU
)
6621 perf_output_put(handle
, data
->cpu_entry
);
6623 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6624 perf_output_put(handle
, data
->id
);
6627 void perf_event__output_id_sample(struct perf_event
*event
,
6628 struct perf_output_handle
*handle
,
6629 struct perf_sample_data
*sample
)
6631 if (event
->attr
.sample_id_all
)
6632 __perf_event__output_id_sample(handle
, sample
);
6635 static void perf_output_read_one(struct perf_output_handle
*handle
,
6636 struct perf_event
*event
,
6637 u64 enabled
, u64 running
)
6639 u64 read_format
= event
->attr
.read_format
;
6643 values
[n
++] = perf_event_count(event
);
6644 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
6645 values
[n
++] = enabled
+
6646 atomic64_read(&event
->child_total_time_enabled
);
6648 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
6649 values
[n
++] = running
+
6650 atomic64_read(&event
->child_total_time_running
);
6652 if (read_format
& PERF_FORMAT_ID
)
6653 values
[n
++] = primary_event_id(event
);
6655 __output_copy(handle
, values
, n
* sizeof(u64
));
6658 static void perf_output_read_group(struct perf_output_handle
*handle
,
6659 struct perf_event
*event
,
6660 u64 enabled
, u64 running
)
6662 struct perf_event
*leader
= event
->group_leader
, *sub
;
6663 u64 read_format
= event
->attr
.read_format
;
6667 values
[n
++] = 1 + leader
->nr_siblings
;
6669 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
6670 values
[n
++] = enabled
;
6672 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
6673 values
[n
++] = running
;
6675 if ((leader
!= event
) &&
6676 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
6677 leader
->pmu
->read(leader
);
6679 values
[n
++] = perf_event_count(leader
);
6680 if (read_format
& PERF_FORMAT_ID
)
6681 values
[n
++] = primary_event_id(leader
);
6683 __output_copy(handle
, values
, n
* sizeof(u64
));
6685 for_each_sibling_event(sub
, leader
) {
6688 if ((sub
!= event
) &&
6689 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
6690 sub
->pmu
->read(sub
);
6692 values
[n
++] = perf_event_count(sub
);
6693 if (read_format
& PERF_FORMAT_ID
)
6694 values
[n
++] = primary_event_id(sub
);
6696 __output_copy(handle
, values
, n
* sizeof(u64
));
6700 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
6701 PERF_FORMAT_TOTAL_TIME_RUNNING)
6704 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
6706 * The problem is that its both hard and excessively expensive to iterate the
6707 * child list, not to mention that its impossible to IPI the children running
6708 * on another CPU, from interrupt/NMI context.
6710 static void perf_output_read(struct perf_output_handle
*handle
,
6711 struct perf_event
*event
)
6713 u64 enabled
= 0, running
= 0, now
;
6714 u64 read_format
= event
->attr
.read_format
;
6717 * compute total_time_enabled, total_time_running
6718 * based on snapshot values taken when the event
6719 * was last scheduled in.
6721 * we cannot simply called update_context_time()
6722 * because of locking issue as we are called in
6725 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
6726 calc_timer_values(event
, &now
, &enabled
, &running
);
6728 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
6729 perf_output_read_group(handle
, event
, enabled
, running
);
6731 perf_output_read_one(handle
, event
, enabled
, running
);
6734 static inline bool perf_sample_save_hw_index(struct perf_event
*event
)
6736 return event
->attr
.branch_sample_type
& PERF_SAMPLE_BRANCH_HW_INDEX
;
6739 void perf_output_sample(struct perf_output_handle
*handle
,
6740 struct perf_event_header
*header
,
6741 struct perf_sample_data
*data
,
6742 struct perf_event
*event
)
6744 u64 sample_type
= data
->type
;
6746 perf_output_put(handle
, *header
);
6748 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6749 perf_output_put(handle
, data
->id
);
6751 if (sample_type
& PERF_SAMPLE_IP
)
6752 perf_output_put(handle
, data
->ip
);
6754 if (sample_type
& PERF_SAMPLE_TID
)
6755 perf_output_put(handle
, data
->tid_entry
);
6757 if (sample_type
& PERF_SAMPLE_TIME
)
6758 perf_output_put(handle
, data
->time
);
6760 if (sample_type
& PERF_SAMPLE_ADDR
)
6761 perf_output_put(handle
, data
->addr
);
6763 if (sample_type
& PERF_SAMPLE_ID
)
6764 perf_output_put(handle
, data
->id
);
6766 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6767 perf_output_put(handle
, data
->stream_id
);
6769 if (sample_type
& PERF_SAMPLE_CPU
)
6770 perf_output_put(handle
, data
->cpu_entry
);
6772 if (sample_type
& PERF_SAMPLE_PERIOD
)
6773 perf_output_put(handle
, data
->period
);
6775 if (sample_type
& PERF_SAMPLE_READ
)
6776 perf_output_read(handle
, event
);
6778 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6781 size
+= data
->callchain
->nr
;
6782 size
*= sizeof(u64
);
6783 __output_copy(handle
, data
->callchain
, size
);
6786 if (sample_type
& PERF_SAMPLE_RAW
) {
6787 struct perf_raw_record
*raw
= data
->raw
;
6790 struct perf_raw_frag
*frag
= &raw
->frag
;
6792 perf_output_put(handle
, raw
->size
);
6795 __output_custom(handle
, frag
->copy
,
6796 frag
->data
, frag
->size
);
6798 __output_copy(handle
, frag
->data
,
6801 if (perf_raw_frag_last(frag
))
6806 __output_skip(handle
, NULL
, frag
->pad
);
6812 .size
= sizeof(u32
),
6815 perf_output_put(handle
, raw
);
6819 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6820 if (data
->br_stack
) {
6823 size
= data
->br_stack
->nr
6824 * sizeof(struct perf_branch_entry
);
6826 perf_output_put(handle
, data
->br_stack
->nr
);
6827 if (perf_sample_save_hw_index(event
))
6828 perf_output_put(handle
, data
->br_stack
->hw_idx
);
6829 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
6832 * we always store at least the value of nr
6835 perf_output_put(handle
, nr
);
6839 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6840 u64 abi
= data
->regs_user
.abi
;
6843 * If there are no regs to dump, notice it through
6844 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6846 perf_output_put(handle
, abi
);
6849 u64 mask
= event
->attr
.sample_regs_user
;
6850 perf_output_sample_regs(handle
,
6851 data
->regs_user
.regs
,
6856 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6857 perf_output_sample_ustack(handle
,
6858 data
->stack_user_size
,
6859 data
->regs_user
.regs
);
6862 if (sample_type
& PERF_SAMPLE_WEIGHT
)
6863 perf_output_put(handle
, data
->weight
);
6865 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6866 perf_output_put(handle
, data
->data_src
.val
);
6868 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6869 perf_output_put(handle
, data
->txn
);
6871 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6872 u64 abi
= data
->regs_intr
.abi
;
6874 * If there are no regs to dump, notice it through
6875 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6877 perf_output_put(handle
, abi
);
6880 u64 mask
= event
->attr
.sample_regs_intr
;
6882 perf_output_sample_regs(handle
,
6883 data
->regs_intr
.regs
,
6888 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6889 perf_output_put(handle
, data
->phys_addr
);
6891 if (sample_type
& PERF_SAMPLE_CGROUP
)
6892 perf_output_put(handle
, data
->cgroup
);
6894 if (sample_type
& PERF_SAMPLE_AUX
) {
6895 perf_output_put(handle
, data
->aux_size
);
6898 perf_aux_sample_output(event
, handle
, data
);
6901 if (!event
->attr
.watermark
) {
6902 int wakeup_events
= event
->attr
.wakeup_events
;
6904 if (wakeup_events
) {
6905 struct perf_buffer
*rb
= handle
->rb
;
6906 int events
= local_inc_return(&rb
->events
);
6908 if (events
>= wakeup_events
) {
6909 local_sub(wakeup_events
, &rb
->events
);
6910 local_inc(&rb
->wakeup
);
6916 static u64
perf_virt_to_phys(u64 virt
)
6919 struct page
*p
= NULL
;
6924 if (virt
>= TASK_SIZE
) {
6925 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6926 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6927 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6928 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6931 * Walking the pages tables for user address.
6932 * Interrupts are disabled, so it prevents any tear down
6933 * of the page tables.
6934 * Try IRQ-safe __get_user_pages_fast first.
6935 * If failed, leave phys_addr as 0.
6937 if (current
->mm
!= NULL
) {
6938 pagefault_disable();
6939 if (__get_user_pages_fast(virt
, 1, 0, &p
) == 1)
6940 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6951 static struct perf_callchain_entry __empty_callchain
= { .nr
= 0, };
6953 struct perf_callchain_entry
*
6954 perf_callchain(struct perf_event
*event
, struct pt_regs
*regs
)
6956 bool kernel
= !event
->attr
.exclude_callchain_kernel
;
6957 bool user
= !event
->attr
.exclude_callchain_user
;
6958 /* Disallow cross-task user callchains. */
6959 bool crosstask
= event
->ctx
->task
&& event
->ctx
->task
!= current
;
6960 const u32 max_stack
= event
->attr
.sample_max_stack
;
6961 struct perf_callchain_entry
*callchain
;
6963 if (!kernel
&& !user
)
6964 return &__empty_callchain
;
6966 callchain
= get_perf_callchain(regs
, 0, kernel
, user
,
6967 max_stack
, crosstask
, true);
6968 return callchain
?: &__empty_callchain
;
6971 void perf_prepare_sample(struct perf_event_header
*header
,
6972 struct perf_sample_data
*data
,
6973 struct perf_event
*event
,
6974 struct pt_regs
*regs
)
6976 u64 sample_type
= event
->attr
.sample_type
;
6978 header
->type
= PERF_RECORD_SAMPLE
;
6979 header
->size
= sizeof(*header
) + event
->header_size
;
6982 header
->misc
|= perf_misc_flags(regs
);
6984 __perf_event_header__init_id(header
, data
, event
);
6986 if (sample_type
& PERF_SAMPLE_IP
)
6987 data
->ip
= perf_instruction_pointer(regs
);
6989 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6992 if (!(sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
))
6993 data
->callchain
= perf_callchain(event
, regs
);
6995 size
+= data
->callchain
->nr
;
6997 header
->size
+= size
* sizeof(u64
);
7000 if (sample_type
& PERF_SAMPLE_RAW
) {
7001 struct perf_raw_record
*raw
= data
->raw
;
7005 struct perf_raw_frag
*frag
= &raw
->frag
;
7010 if (perf_raw_frag_last(frag
))
7015 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
7016 raw
->size
= size
- sizeof(u32
);
7017 frag
->pad
= raw
->size
- sum
;
7022 header
->size
+= size
;
7025 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7026 int size
= sizeof(u64
); /* nr */
7027 if (data
->br_stack
) {
7028 if (perf_sample_save_hw_index(event
))
7029 size
+= sizeof(u64
);
7031 size
+= data
->br_stack
->nr
7032 * sizeof(struct perf_branch_entry
);
7034 header
->size
+= size
;
7037 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
7038 perf_sample_regs_user(&data
->regs_user
, regs
,
7039 &data
->regs_user_copy
);
7041 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
7042 /* regs dump ABI info */
7043 int size
= sizeof(u64
);
7045 if (data
->regs_user
.regs
) {
7046 u64 mask
= event
->attr
.sample_regs_user
;
7047 size
+= hweight64(mask
) * sizeof(u64
);
7050 header
->size
+= size
;
7053 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
7055 * Either we need PERF_SAMPLE_STACK_USER bit to be always
7056 * processed as the last one or have additional check added
7057 * in case new sample type is added, because we could eat
7058 * up the rest of the sample size.
7060 u16 stack_size
= event
->attr
.sample_stack_user
;
7061 u16 size
= sizeof(u64
);
7063 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
7064 data
->regs_user
.regs
);
7067 * If there is something to dump, add space for the dump
7068 * itself and for the field that tells the dynamic size,
7069 * which is how many have been actually dumped.
7072 size
+= sizeof(u64
) + stack_size
;
7074 data
->stack_user_size
= stack_size
;
7075 header
->size
+= size
;
7078 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
7079 /* regs dump ABI info */
7080 int size
= sizeof(u64
);
7082 perf_sample_regs_intr(&data
->regs_intr
, regs
);
7084 if (data
->regs_intr
.regs
) {
7085 u64 mask
= event
->attr
.sample_regs_intr
;
7087 size
+= hweight64(mask
) * sizeof(u64
);
7090 header
->size
+= size
;
7093 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
7094 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
7096 #ifdef CONFIG_CGROUP_PERF
7097 if (sample_type
& PERF_SAMPLE_CGROUP
) {
7098 struct cgroup
*cgrp
;
7100 /* protected by RCU */
7101 cgrp
= task_css_check(current
, perf_event_cgrp_id
, 1)->cgroup
;
7102 data
->cgroup
= cgroup_id(cgrp
);
7106 if (sample_type
& PERF_SAMPLE_AUX
) {
7109 header
->size
+= sizeof(u64
); /* size */
7112 * Given the 16bit nature of header::size, an AUX sample can
7113 * easily overflow it, what with all the preceding sample bits.
7114 * Make sure this doesn't happen by using up to U16_MAX bytes
7115 * per sample in total (rounded down to 8 byte boundary).
7117 size
= min_t(size_t, U16_MAX
- header
->size
,
7118 event
->attr
.aux_sample_size
);
7119 size
= rounddown(size
, 8);
7120 size
= perf_prepare_sample_aux(event
, data
, size
);
7122 WARN_ON_ONCE(size
+ header
->size
> U16_MAX
);
7123 header
->size
+= size
;
7126 * If you're adding more sample types here, you likely need to do
7127 * something about the overflowing header::size, like repurpose the
7128 * lowest 3 bits of size, which should be always zero at the moment.
7129 * This raises a more important question, do we really need 512k sized
7130 * samples and why, so good argumentation is in order for whatever you
7133 WARN_ON_ONCE(header
->size
& 7);
7136 static __always_inline
int
7137 __perf_event_output(struct perf_event
*event
,
7138 struct perf_sample_data
*data
,
7139 struct pt_regs
*regs
,
7140 int (*output_begin
)(struct perf_output_handle
*,
7141 struct perf_event
*,
7144 struct perf_output_handle handle
;
7145 struct perf_event_header header
;
7148 /* protect the callchain buffers */
7151 perf_prepare_sample(&header
, data
, event
, regs
);
7153 err
= output_begin(&handle
, event
, header
.size
);
7157 perf_output_sample(&handle
, &header
, data
, event
);
7159 perf_output_end(&handle
);
7167 perf_event_output_forward(struct perf_event
*event
,
7168 struct perf_sample_data
*data
,
7169 struct pt_regs
*regs
)
7171 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
7175 perf_event_output_backward(struct perf_event
*event
,
7176 struct perf_sample_data
*data
,
7177 struct pt_regs
*regs
)
7179 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
7183 perf_event_output(struct perf_event
*event
,
7184 struct perf_sample_data
*data
,
7185 struct pt_regs
*regs
)
7187 return __perf_event_output(event
, data
, regs
, perf_output_begin
);
7194 struct perf_read_event
{
7195 struct perf_event_header header
;
7202 perf_event_read_event(struct perf_event
*event
,
7203 struct task_struct
*task
)
7205 struct perf_output_handle handle
;
7206 struct perf_sample_data sample
;
7207 struct perf_read_event read_event
= {
7209 .type
= PERF_RECORD_READ
,
7211 .size
= sizeof(read_event
) + event
->read_size
,
7213 .pid
= perf_event_pid(event
, task
),
7214 .tid
= perf_event_tid(event
, task
),
7218 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
7219 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
7223 perf_output_put(&handle
, read_event
);
7224 perf_output_read(&handle
, event
);
7225 perf_event__output_id_sample(event
, &handle
, &sample
);
7227 perf_output_end(&handle
);
7230 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
7233 perf_iterate_ctx(struct perf_event_context
*ctx
,
7234 perf_iterate_f output
,
7235 void *data
, bool all
)
7237 struct perf_event
*event
;
7239 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7241 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7243 if (!event_filter_match(event
))
7247 output(event
, data
);
7251 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
7253 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
7254 struct perf_event
*event
;
7256 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
7258 * Skip events that are not fully formed yet; ensure that
7259 * if we observe event->ctx, both event and ctx will be
7260 * complete enough. See perf_install_in_context().
7262 if (!smp_load_acquire(&event
->ctx
))
7265 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7267 if (!event_filter_match(event
))
7269 output(event
, data
);
7274 * Iterate all events that need to receive side-band events.
7276 * For new callers; ensure that account_pmu_sb_event() includes
7277 * your event, otherwise it might not get delivered.
7280 perf_iterate_sb(perf_iterate_f output
, void *data
,
7281 struct perf_event_context
*task_ctx
)
7283 struct perf_event_context
*ctx
;
7290 * If we have task_ctx != NULL we only notify the task context itself.
7291 * The task_ctx is set only for EXIT events before releasing task
7295 perf_iterate_ctx(task_ctx
, output
, data
, false);
7299 perf_iterate_sb_cpu(output
, data
);
7301 for_each_task_context_nr(ctxn
) {
7302 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7304 perf_iterate_ctx(ctx
, output
, data
, false);
7312 * Clear all file-based filters at exec, they'll have to be
7313 * re-instated when/if these objects are mmapped again.
7315 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
7317 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7318 struct perf_addr_filter
*filter
;
7319 unsigned int restart
= 0, count
= 0;
7320 unsigned long flags
;
7322 if (!has_addr_filter(event
))
7325 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7326 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7327 if (filter
->path
.dentry
) {
7328 event
->addr_filter_ranges
[count
].start
= 0;
7329 event
->addr_filter_ranges
[count
].size
= 0;
7337 event
->addr_filters_gen
++;
7338 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7341 perf_event_stop(event
, 1);
7344 void perf_event_exec(void)
7346 struct perf_event_context
*ctx
;
7350 for_each_task_context_nr(ctxn
) {
7351 ctx
= current
->perf_event_ctxp
[ctxn
];
7355 perf_event_enable_on_exec(ctxn
);
7357 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
7363 struct remote_output
{
7364 struct perf_buffer
*rb
;
7368 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
7370 struct perf_event
*parent
= event
->parent
;
7371 struct remote_output
*ro
= data
;
7372 struct perf_buffer
*rb
= ro
->rb
;
7373 struct stop_event_data sd
= {
7377 if (!has_aux(event
))
7384 * In case of inheritance, it will be the parent that links to the
7385 * ring-buffer, but it will be the child that's actually using it.
7387 * We are using event::rb to determine if the event should be stopped,
7388 * however this may race with ring_buffer_attach() (through set_output),
7389 * which will make us skip the event that actually needs to be stopped.
7390 * So ring_buffer_attach() has to stop an aux event before re-assigning
7393 if (rcu_dereference(parent
->rb
) == rb
)
7394 ro
->err
= __perf_event_stop(&sd
);
7397 static int __perf_pmu_output_stop(void *info
)
7399 struct perf_event
*event
= info
;
7400 struct pmu
*pmu
= event
->ctx
->pmu
;
7401 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7402 struct remote_output ro
= {
7407 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
7408 if (cpuctx
->task_ctx
)
7409 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
7416 static void perf_pmu_output_stop(struct perf_event
*event
)
7418 struct perf_event
*iter
;
7423 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
7425 * For per-CPU events, we need to make sure that neither they
7426 * nor their children are running; for cpu==-1 events it's
7427 * sufficient to stop the event itself if it's active, since
7428 * it can't have children.
7432 cpu
= READ_ONCE(iter
->oncpu
);
7437 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
7438 if (err
== -EAGAIN
) {
7447 * task tracking -- fork/exit
7449 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
7452 struct perf_task_event
{
7453 struct task_struct
*task
;
7454 struct perf_event_context
*task_ctx
;
7457 struct perf_event_header header
;
7467 static int perf_event_task_match(struct perf_event
*event
)
7469 return event
->attr
.comm
|| event
->attr
.mmap
||
7470 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
7474 static void perf_event_task_output(struct perf_event
*event
,
7477 struct perf_task_event
*task_event
= data
;
7478 struct perf_output_handle handle
;
7479 struct perf_sample_data sample
;
7480 struct task_struct
*task
= task_event
->task
;
7481 int ret
, size
= task_event
->event_id
.header
.size
;
7483 if (!perf_event_task_match(event
))
7486 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
7488 ret
= perf_output_begin(&handle
, event
,
7489 task_event
->event_id
.header
.size
);
7493 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
7494 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
7496 if (task_event
->event_id
.header
.type
== PERF_RECORD_EXIT
) {
7497 task_event
->event_id
.ppid
= perf_event_pid(event
,
7499 task_event
->event_id
.ptid
= perf_event_pid(event
,
7501 } else { /* PERF_RECORD_FORK */
7502 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
7503 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
7506 task_event
->event_id
.time
= perf_event_clock(event
);
7508 perf_output_put(&handle
, task_event
->event_id
);
7510 perf_event__output_id_sample(event
, &handle
, &sample
);
7512 perf_output_end(&handle
);
7514 task_event
->event_id
.header
.size
= size
;
7517 static void perf_event_task(struct task_struct
*task
,
7518 struct perf_event_context
*task_ctx
,
7521 struct perf_task_event task_event
;
7523 if (!atomic_read(&nr_comm_events
) &&
7524 !atomic_read(&nr_mmap_events
) &&
7525 !atomic_read(&nr_task_events
))
7528 task_event
= (struct perf_task_event
){
7530 .task_ctx
= task_ctx
,
7533 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
7535 .size
= sizeof(task_event
.event_id
),
7545 perf_iterate_sb(perf_event_task_output
,
7550 void perf_event_fork(struct task_struct
*task
)
7552 perf_event_task(task
, NULL
, 1);
7553 perf_event_namespaces(task
);
7560 struct perf_comm_event
{
7561 struct task_struct
*task
;
7566 struct perf_event_header header
;
7573 static int perf_event_comm_match(struct perf_event
*event
)
7575 return event
->attr
.comm
;
7578 static void perf_event_comm_output(struct perf_event
*event
,
7581 struct perf_comm_event
*comm_event
= data
;
7582 struct perf_output_handle handle
;
7583 struct perf_sample_data sample
;
7584 int size
= comm_event
->event_id
.header
.size
;
7587 if (!perf_event_comm_match(event
))
7590 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
7591 ret
= perf_output_begin(&handle
, event
,
7592 comm_event
->event_id
.header
.size
);
7597 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
7598 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
7600 perf_output_put(&handle
, comm_event
->event_id
);
7601 __output_copy(&handle
, comm_event
->comm
,
7602 comm_event
->comm_size
);
7604 perf_event__output_id_sample(event
, &handle
, &sample
);
7606 perf_output_end(&handle
);
7608 comm_event
->event_id
.header
.size
= size
;
7611 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
7613 char comm
[TASK_COMM_LEN
];
7616 memset(comm
, 0, sizeof(comm
));
7617 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
7618 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
7620 comm_event
->comm
= comm
;
7621 comm_event
->comm_size
= size
;
7623 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
7625 perf_iterate_sb(perf_event_comm_output
,
7630 void perf_event_comm(struct task_struct
*task
, bool exec
)
7632 struct perf_comm_event comm_event
;
7634 if (!atomic_read(&nr_comm_events
))
7637 comm_event
= (struct perf_comm_event
){
7643 .type
= PERF_RECORD_COMM
,
7644 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
7652 perf_event_comm_event(&comm_event
);
7656 * namespaces tracking
7659 struct perf_namespaces_event
{
7660 struct task_struct
*task
;
7663 struct perf_event_header header
;
7668 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
7672 static int perf_event_namespaces_match(struct perf_event
*event
)
7674 return event
->attr
.namespaces
;
7677 static void perf_event_namespaces_output(struct perf_event
*event
,
7680 struct perf_namespaces_event
*namespaces_event
= data
;
7681 struct perf_output_handle handle
;
7682 struct perf_sample_data sample
;
7683 u16 header_size
= namespaces_event
->event_id
.header
.size
;
7686 if (!perf_event_namespaces_match(event
))
7689 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
7691 ret
= perf_output_begin(&handle
, event
,
7692 namespaces_event
->event_id
.header
.size
);
7696 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
7697 namespaces_event
->task
);
7698 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
7699 namespaces_event
->task
);
7701 perf_output_put(&handle
, namespaces_event
->event_id
);
7703 perf_event__output_id_sample(event
, &handle
, &sample
);
7705 perf_output_end(&handle
);
7707 namespaces_event
->event_id
.header
.size
= header_size
;
7710 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
7711 struct task_struct
*task
,
7712 const struct proc_ns_operations
*ns_ops
)
7714 struct path ns_path
;
7715 struct inode
*ns_inode
;
7718 error
= ns_get_path(&ns_path
, task
, ns_ops
);
7720 ns_inode
= ns_path
.dentry
->d_inode
;
7721 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
7722 ns_link_info
->ino
= ns_inode
->i_ino
;
7727 void perf_event_namespaces(struct task_struct
*task
)
7729 struct perf_namespaces_event namespaces_event
;
7730 struct perf_ns_link_info
*ns_link_info
;
7732 if (!atomic_read(&nr_namespaces_events
))
7735 namespaces_event
= (struct perf_namespaces_event
){
7739 .type
= PERF_RECORD_NAMESPACES
,
7741 .size
= sizeof(namespaces_event
.event_id
),
7745 .nr_namespaces
= NR_NAMESPACES
,
7746 /* .link_info[NR_NAMESPACES] */
7750 ns_link_info
= namespaces_event
.event_id
.link_info
;
7752 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
7753 task
, &mntns_operations
);
7755 #ifdef CONFIG_USER_NS
7756 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
7757 task
, &userns_operations
);
7759 #ifdef CONFIG_NET_NS
7760 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
7761 task
, &netns_operations
);
7763 #ifdef CONFIG_UTS_NS
7764 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
7765 task
, &utsns_operations
);
7767 #ifdef CONFIG_IPC_NS
7768 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
7769 task
, &ipcns_operations
);
7771 #ifdef CONFIG_PID_NS
7772 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
7773 task
, &pidns_operations
);
7775 #ifdef CONFIG_CGROUPS
7776 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
7777 task
, &cgroupns_operations
);
7780 perf_iterate_sb(perf_event_namespaces_output
,
7788 #ifdef CONFIG_CGROUP_PERF
7790 struct perf_cgroup_event
{
7794 struct perf_event_header header
;
7800 static int perf_event_cgroup_match(struct perf_event
*event
)
7802 return event
->attr
.cgroup
;
7805 static void perf_event_cgroup_output(struct perf_event
*event
, void *data
)
7807 struct perf_cgroup_event
*cgroup_event
= data
;
7808 struct perf_output_handle handle
;
7809 struct perf_sample_data sample
;
7810 u16 header_size
= cgroup_event
->event_id
.header
.size
;
7813 if (!perf_event_cgroup_match(event
))
7816 perf_event_header__init_id(&cgroup_event
->event_id
.header
,
7818 ret
= perf_output_begin(&handle
, event
,
7819 cgroup_event
->event_id
.header
.size
);
7823 perf_output_put(&handle
, cgroup_event
->event_id
);
7824 __output_copy(&handle
, cgroup_event
->path
, cgroup_event
->path_size
);
7826 perf_event__output_id_sample(event
, &handle
, &sample
);
7828 perf_output_end(&handle
);
7830 cgroup_event
->event_id
.header
.size
= header_size
;
7833 static void perf_event_cgroup(struct cgroup
*cgrp
)
7835 struct perf_cgroup_event cgroup_event
;
7836 char path_enomem
[16] = "//enomem";
7840 if (!atomic_read(&nr_cgroup_events
))
7843 cgroup_event
= (struct perf_cgroup_event
){
7846 .type
= PERF_RECORD_CGROUP
,
7848 .size
= sizeof(cgroup_event
.event_id
),
7850 .id
= cgroup_id(cgrp
),
7854 pathname
= kmalloc(PATH_MAX
, GFP_KERNEL
);
7855 if (pathname
== NULL
) {
7856 cgroup_event
.path
= path_enomem
;
7858 /* just to be sure to have enough space for alignment */
7859 cgroup_path(cgrp
, pathname
, PATH_MAX
- sizeof(u64
));
7860 cgroup_event
.path
= pathname
;
7864 * Since our buffer works in 8 byte units we need to align our string
7865 * size to a multiple of 8. However, we must guarantee the tail end is
7866 * zero'd out to avoid leaking random bits to userspace.
7868 size
= strlen(cgroup_event
.path
) + 1;
7869 while (!IS_ALIGNED(size
, sizeof(u64
)))
7870 cgroup_event
.path
[size
++] = '\0';
7872 cgroup_event
.event_id
.header
.size
+= size
;
7873 cgroup_event
.path_size
= size
;
7875 perf_iterate_sb(perf_event_cgroup_output
,
7888 struct perf_mmap_event
{
7889 struct vm_area_struct
*vma
;
7891 const char *file_name
;
7899 struct perf_event_header header
;
7909 static int perf_event_mmap_match(struct perf_event
*event
,
7912 struct perf_mmap_event
*mmap_event
= data
;
7913 struct vm_area_struct
*vma
= mmap_event
->vma
;
7914 int executable
= vma
->vm_flags
& VM_EXEC
;
7916 return (!executable
&& event
->attr
.mmap_data
) ||
7917 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
7920 static void perf_event_mmap_output(struct perf_event
*event
,
7923 struct perf_mmap_event
*mmap_event
= data
;
7924 struct perf_output_handle handle
;
7925 struct perf_sample_data sample
;
7926 int size
= mmap_event
->event_id
.header
.size
;
7927 u32 type
= mmap_event
->event_id
.header
.type
;
7930 if (!perf_event_mmap_match(event
, data
))
7933 if (event
->attr
.mmap2
) {
7934 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
7935 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
7936 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
7937 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
7938 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
7939 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
7940 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
7943 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
7944 ret
= perf_output_begin(&handle
, event
,
7945 mmap_event
->event_id
.header
.size
);
7949 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
7950 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
7952 perf_output_put(&handle
, mmap_event
->event_id
);
7954 if (event
->attr
.mmap2
) {
7955 perf_output_put(&handle
, mmap_event
->maj
);
7956 perf_output_put(&handle
, mmap_event
->min
);
7957 perf_output_put(&handle
, mmap_event
->ino
);
7958 perf_output_put(&handle
, mmap_event
->ino_generation
);
7959 perf_output_put(&handle
, mmap_event
->prot
);
7960 perf_output_put(&handle
, mmap_event
->flags
);
7963 __output_copy(&handle
, mmap_event
->file_name
,
7964 mmap_event
->file_size
);
7966 perf_event__output_id_sample(event
, &handle
, &sample
);
7968 perf_output_end(&handle
);
7970 mmap_event
->event_id
.header
.size
= size
;
7971 mmap_event
->event_id
.header
.type
= type
;
7974 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
7976 struct vm_area_struct
*vma
= mmap_event
->vma
;
7977 struct file
*file
= vma
->vm_file
;
7978 int maj
= 0, min
= 0;
7979 u64 ino
= 0, gen
= 0;
7980 u32 prot
= 0, flags
= 0;
7986 if (vma
->vm_flags
& VM_READ
)
7988 if (vma
->vm_flags
& VM_WRITE
)
7990 if (vma
->vm_flags
& VM_EXEC
)
7993 if (vma
->vm_flags
& VM_MAYSHARE
)
7996 flags
= MAP_PRIVATE
;
7998 if (vma
->vm_flags
& VM_DENYWRITE
)
7999 flags
|= MAP_DENYWRITE
;
8000 if (vma
->vm_flags
& VM_MAYEXEC
)
8001 flags
|= MAP_EXECUTABLE
;
8002 if (vma
->vm_flags
& VM_LOCKED
)
8003 flags
|= MAP_LOCKED
;
8004 if (is_vm_hugetlb_page(vma
))
8005 flags
|= MAP_HUGETLB
;
8008 struct inode
*inode
;
8011 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
8017 * d_path() works from the end of the rb backwards, so we
8018 * need to add enough zero bytes after the string to handle
8019 * the 64bit alignment we do later.
8021 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
8026 inode
= file_inode(vma
->vm_file
);
8027 dev
= inode
->i_sb
->s_dev
;
8029 gen
= inode
->i_generation
;
8035 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
8036 name
= (char *) vma
->vm_ops
->name(vma
);
8041 name
= (char *)arch_vma_name(vma
);
8045 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
8046 vma
->vm_end
>= vma
->vm_mm
->brk
) {
8050 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
8051 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
8061 strlcpy(tmp
, name
, sizeof(tmp
));
8065 * Since our buffer works in 8 byte units we need to align our string
8066 * size to a multiple of 8. However, we must guarantee the tail end is
8067 * zero'd out to avoid leaking random bits to userspace.
8069 size
= strlen(name
)+1;
8070 while (!IS_ALIGNED(size
, sizeof(u64
)))
8071 name
[size
++] = '\0';
8073 mmap_event
->file_name
= name
;
8074 mmap_event
->file_size
= size
;
8075 mmap_event
->maj
= maj
;
8076 mmap_event
->min
= min
;
8077 mmap_event
->ino
= ino
;
8078 mmap_event
->ino_generation
= gen
;
8079 mmap_event
->prot
= prot
;
8080 mmap_event
->flags
= flags
;
8082 if (!(vma
->vm_flags
& VM_EXEC
))
8083 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
8085 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
8087 perf_iterate_sb(perf_event_mmap_output
,
8095 * Check whether inode and address range match filter criteria.
8097 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
8098 struct file
*file
, unsigned long offset
,
8101 /* d_inode(NULL) won't be equal to any mapped user-space file */
8102 if (!filter
->path
.dentry
)
8105 if (d_inode(filter
->path
.dentry
) != file_inode(file
))
8108 if (filter
->offset
> offset
+ size
)
8111 if (filter
->offset
+ filter
->size
< offset
)
8117 static bool perf_addr_filter_vma_adjust(struct perf_addr_filter
*filter
,
8118 struct vm_area_struct
*vma
,
8119 struct perf_addr_filter_range
*fr
)
8121 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8122 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8123 struct file
*file
= vma
->vm_file
;
8125 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8128 if (filter
->offset
< off
) {
8129 fr
->start
= vma
->vm_start
;
8130 fr
->size
= min(vma_size
, filter
->size
- (off
- filter
->offset
));
8132 fr
->start
= vma
->vm_start
+ filter
->offset
- off
;
8133 fr
->size
= min(vma
->vm_end
- fr
->start
, filter
->size
);
8139 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
8141 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8142 struct vm_area_struct
*vma
= data
;
8143 struct perf_addr_filter
*filter
;
8144 unsigned int restart
= 0, count
= 0;
8145 unsigned long flags
;
8147 if (!has_addr_filter(event
))
8153 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8154 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8155 if (perf_addr_filter_vma_adjust(filter
, vma
,
8156 &event
->addr_filter_ranges
[count
]))
8163 event
->addr_filters_gen
++;
8164 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8167 perf_event_stop(event
, 1);
8171 * Adjust all task's events' filters to the new vma
8173 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
8175 struct perf_event_context
*ctx
;
8179 * Data tracing isn't supported yet and as such there is no need
8180 * to keep track of anything that isn't related to executable code:
8182 if (!(vma
->vm_flags
& VM_EXEC
))
8186 for_each_task_context_nr(ctxn
) {
8187 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
8191 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
8196 void perf_event_mmap(struct vm_area_struct
*vma
)
8198 struct perf_mmap_event mmap_event
;
8200 if (!atomic_read(&nr_mmap_events
))
8203 mmap_event
= (struct perf_mmap_event
){
8209 .type
= PERF_RECORD_MMAP
,
8210 .misc
= PERF_RECORD_MISC_USER
,
8215 .start
= vma
->vm_start
,
8216 .len
= vma
->vm_end
- vma
->vm_start
,
8217 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
8219 /* .maj (attr_mmap2 only) */
8220 /* .min (attr_mmap2 only) */
8221 /* .ino (attr_mmap2 only) */
8222 /* .ino_generation (attr_mmap2 only) */
8223 /* .prot (attr_mmap2 only) */
8224 /* .flags (attr_mmap2 only) */
8227 perf_addr_filters_adjust(vma
);
8228 perf_event_mmap_event(&mmap_event
);
8231 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
8232 unsigned long size
, u64 flags
)
8234 struct perf_output_handle handle
;
8235 struct perf_sample_data sample
;
8236 struct perf_aux_event
{
8237 struct perf_event_header header
;
8243 .type
= PERF_RECORD_AUX
,
8245 .size
= sizeof(rec
),
8253 perf_event_header__init_id(&rec
.header
, &sample
, event
);
8254 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
8259 perf_output_put(&handle
, rec
);
8260 perf_event__output_id_sample(event
, &handle
, &sample
);
8262 perf_output_end(&handle
);
8266 * Lost/dropped samples logging
8268 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
8270 struct perf_output_handle handle
;
8271 struct perf_sample_data sample
;
8275 struct perf_event_header header
;
8277 } lost_samples_event
= {
8279 .type
= PERF_RECORD_LOST_SAMPLES
,
8281 .size
= sizeof(lost_samples_event
),
8286 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
8288 ret
= perf_output_begin(&handle
, event
,
8289 lost_samples_event
.header
.size
);
8293 perf_output_put(&handle
, lost_samples_event
);
8294 perf_event__output_id_sample(event
, &handle
, &sample
);
8295 perf_output_end(&handle
);
8299 * context_switch tracking
8302 struct perf_switch_event
{
8303 struct task_struct
*task
;
8304 struct task_struct
*next_prev
;
8307 struct perf_event_header header
;
8313 static int perf_event_switch_match(struct perf_event
*event
)
8315 return event
->attr
.context_switch
;
8318 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
8320 struct perf_switch_event
*se
= data
;
8321 struct perf_output_handle handle
;
8322 struct perf_sample_data sample
;
8325 if (!perf_event_switch_match(event
))
8328 /* Only CPU-wide events are allowed to see next/prev pid/tid */
8329 if (event
->ctx
->task
) {
8330 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
8331 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
8333 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
8334 se
->event_id
.header
.size
= sizeof(se
->event_id
);
8335 se
->event_id
.next_prev_pid
=
8336 perf_event_pid(event
, se
->next_prev
);
8337 se
->event_id
.next_prev_tid
=
8338 perf_event_tid(event
, se
->next_prev
);
8341 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
8343 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
8347 if (event
->ctx
->task
)
8348 perf_output_put(&handle
, se
->event_id
.header
);
8350 perf_output_put(&handle
, se
->event_id
);
8352 perf_event__output_id_sample(event
, &handle
, &sample
);
8354 perf_output_end(&handle
);
8357 static void perf_event_switch(struct task_struct
*task
,
8358 struct task_struct
*next_prev
, bool sched_in
)
8360 struct perf_switch_event switch_event
;
8362 /* N.B. caller checks nr_switch_events != 0 */
8364 switch_event
= (struct perf_switch_event
){
8366 .next_prev
= next_prev
,
8370 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
8373 /* .next_prev_pid */
8374 /* .next_prev_tid */
8378 if (!sched_in
&& task
->state
== TASK_RUNNING
)
8379 switch_event
.event_id
.header
.misc
|=
8380 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT
;
8382 perf_iterate_sb(perf_event_switch_output
,
8388 * IRQ throttle logging
8391 static void perf_log_throttle(struct perf_event
*event
, int enable
)
8393 struct perf_output_handle handle
;
8394 struct perf_sample_data sample
;
8398 struct perf_event_header header
;
8402 } throttle_event
= {
8404 .type
= PERF_RECORD_THROTTLE
,
8406 .size
= sizeof(throttle_event
),
8408 .time
= perf_event_clock(event
),
8409 .id
= primary_event_id(event
),
8410 .stream_id
= event
->id
,
8414 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
8416 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
8418 ret
= perf_output_begin(&handle
, event
,
8419 throttle_event
.header
.size
);
8423 perf_output_put(&handle
, throttle_event
);
8424 perf_event__output_id_sample(event
, &handle
, &sample
);
8425 perf_output_end(&handle
);
8429 * ksymbol register/unregister tracking
8432 struct perf_ksymbol_event
{
8436 struct perf_event_header header
;
8444 static int perf_event_ksymbol_match(struct perf_event
*event
)
8446 return event
->attr
.ksymbol
;
8449 static void perf_event_ksymbol_output(struct perf_event
*event
, void *data
)
8451 struct perf_ksymbol_event
*ksymbol_event
= data
;
8452 struct perf_output_handle handle
;
8453 struct perf_sample_data sample
;
8456 if (!perf_event_ksymbol_match(event
))
8459 perf_event_header__init_id(&ksymbol_event
->event_id
.header
,
8461 ret
= perf_output_begin(&handle
, event
,
8462 ksymbol_event
->event_id
.header
.size
);
8466 perf_output_put(&handle
, ksymbol_event
->event_id
);
8467 __output_copy(&handle
, ksymbol_event
->name
, ksymbol_event
->name_len
);
8468 perf_event__output_id_sample(event
, &handle
, &sample
);
8470 perf_output_end(&handle
);
8473 void perf_event_ksymbol(u16 ksym_type
, u64 addr
, u32 len
, bool unregister
,
8476 struct perf_ksymbol_event ksymbol_event
;
8477 char name
[KSYM_NAME_LEN
];
8481 if (!atomic_read(&nr_ksymbol_events
))
8484 if (ksym_type
>= PERF_RECORD_KSYMBOL_TYPE_MAX
||
8485 ksym_type
== PERF_RECORD_KSYMBOL_TYPE_UNKNOWN
)
8488 strlcpy(name
, sym
, KSYM_NAME_LEN
);
8489 name_len
= strlen(name
) + 1;
8490 while (!IS_ALIGNED(name_len
, sizeof(u64
)))
8491 name
[name_len
++] = '\0';
8492 BUILD_BUG_ON(KSYM_NAME_LEN
% sizeof(u64
));
8495 flags
|= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER
;
8497 ksymbol_event
= (struct perf_ksymbol_event
){
8499 .name_len
= name_len
,
8502 .type
= PERF_RECORD_KSYMBOL
,
8503 .size
= sizeof(ksymbol_event
.event_id
) +
8508 .ksym_type
= ksym_type
,
8513 perf_iterate_sb(perf_event_ksymbol_output
, &ksymbol_event
, NULL
);
8516 WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__
, ksym_type
);
8520 * bpf program load/unload tracking
8523 struct perf_bpf_event
{
8524 struct bpf_prog
*prog
;
8526 struct perf_event_header header
;
8530 u8 tag
[BPF_TAG_SIZE
];
8534 static int perf_event_bpf_match(struct perf_event
*event
)
8536 return event
->attr
.bpf_event
;
8539 static void perf_event_bpf_output(struct perf_event
*event
, void *data
)
8541 struct perf_bpf_event
*bpf_event
= data
;
8542 struct perf_output_handle handle
;
8543 struct perf_sample_data sample
;
8546 if (!perf_event_bpf_match(event
))
8549 perf_event_header__init_id(&bpf_event
->event_id
.header
,
8551 ret
= perf_output_begin(&handle
, event
,
8552 bpf_event
->event_id
.header
.size
);
8556 perf_output_put(&handle
, bpf_event
->event_id
);
8557 perf_event__output_id_sample(event
, &handle
, &sample
);
8559 perf_output_end(&handle
);
8562 static void perf_event_bpf_emit_ksymbols(struct bpf_prog
*prog
,
8563 enum perf_bpf_event_type type
)
8565 bool unregister
= type
== PERF_BPF_EVENT_PROG_UNLOAD
;
8568 if (prog
->aux
->func_cnt
== 0) {
8569 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF
,
8570 (u64
)(unsigned long)prog
->bpf_func
,
8571 prog
->jited_len
, unregister
,
8572 prog
->aux
->ksym
.name
);
8574 for (i
= 0; i
< prog
->aux
->func_cnt
; i
++) {
8575 struct bpf_prog
*subprog
= prog
->aux
->func
[i
];
8578 PERF_RECORD_KSYMBOL_TYPE_BPF
,
8579 (u64
)(unsigned long)subprog
->bpf_func
,
8580 subprog
->jited_len
, unregister
,
8581 prog
->aux
->ksym
.name
);
8586 void perf_event_bpf_event(struct bpf_prog
*prog
,
8587 enum perf_bpf_event_type type
,
8590 struct perf_bpf_event bpf_event
;
8592 if (type
<= PERF_BPF_EVENT_UNKNOWN
||
8593 type
>= PERF_BPF_EVENT_MAX
)
8597 case PERF_BPF_EVENT_PROG_LOAD
:
8598 case PERF_BPF_EVENT_PROG_UNLOAD
:
8599 if (atomic_read(&nr_ksymbol_events
))
8600 perf_event_bpf_emit_ksymbols(prog
, type
);
8606 if (!atomic_read(&nr_bpf_events
))
8609 bpf_event
= (struct perf_bpf_event
){
8613 .type
= PERF_RECORD_BPF_EVENT
,
8614 .size
= sizeof(bpf_event
.event_id
),
8618 .id
= prog
->aux
->id
,
8622 BUILD_BUG_ON(BPF_TAG_SIZE
% sizeof(u64
));
8624 memcpy(bpf_event
.event_id
.tag
, prog
->tag
, BPF_TAG_SIZE
);
8625 perf_iterate_sb(perf_event_bpf_output
, &bpf_event
, NULL
);
8628 void perf_event_itrace_started(struct perf_event
*event
)
8630 event
->attach_state
|= PERF_ATTACH_ITRACE
;
8633 static void perf_log_itrace_start(struct perf_event
*event
)
8635 struct perf_output_handle handle
;
8636 struct perf_sample_data sample
;
8637 struct perf_aux_event
{
8638 struct perf_event_header header
;
8645 event
= event
->parent
;
8647 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
8648 event
->attach_state
& PERF_ATTACH_ITRACE
)
8651 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
8652 rec
.header
.misc
= 0;
8653 rec
.header
.size
= sizeof(rec
);
8654 rec
.pid
= perf_event_pid(event
, current
);
8655 rec
.tid
= perf_event_tid(event
, current
);
8657 perf_event_header__init_id(&rec
.header
, &sample
, event
);
8658 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
8663 perf_output_put(&handle
, rec
);
8664 perf_event__output_id_sample(event
, &handle
, &sample
);
8666 perf_output_end(&handle
);
8670 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
8672 struct hw_perf_event
*hwc
= &event
->hw
;
8676 seq
= __this_cpu_read(perf_throttled_seq
);
8677 if (seq
!= hwc
->interrupts_seq
) {
8678 hwc
->interrupts_seq
= seq
;
8679 hwc
->interrupts
= 1;
8682 if (unlikely(throttle
8683 && hwc
->interrupts
>= max_samples_per_tick
)) {
8684 __this_cpu_inc(perf_throttled_count
);
8685 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
8686 hwc
->interrupts
= MAX_INTERRUPTS
;
8687 perf_log_throttle(event
, 0);
8692 if (event
->attr
.freq
) {
8693 u64 now
= perf_clock();
8694 s64 delta
= now
- hwc
->freq_time_stamp
;
8696 hwc
->freq_time_stamp
= now
;
8698 if (delta
> 0 && delta
< 2*TICK_NSEC
)
8699 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
8705 int perf_event_account_interrupt(struct perf_event
*event
)
8707 return __perf_event_account_interrupt(event
, 1);
8711 * Generic event overflow handling, sampling.
8714 static int __perf_event_overflow(struct perf_event
*event
,
8715 int throttle
, struct perf_sample_data
*data
,
8716 struct pt_regs
*regs
)
8718 int events
= atomic_read(&event
->event_limit
);
8722 * Non-sampling counters might still use the PMI to fold short
8723 * hardware counters, ignore those.
8725 if (unlikely(!is_sampling_event(event
)))
8728 ret
= __perf_event_account_interrupt(event
, throttle
);
8731 * XXX event_limit might not quite work as expected on inherited
8735 event
->pending_kill
= POLL_IN
;
8736 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
8738 event
->pending_kill
= POLL_HUP
;
8740 perf_event_disable_inatomic(event
);
8743 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
8745 if (*perf_event_fasync(event
) && event
->pending_kill
) {
8746 event
->pending_wakeup
= 1;
8747 irq_work_queue(&event
->pending
);
8753 int perf_event_overflow(struct perf_event
*event
,
8754 struct perf_sample_data
*data
,
8755 struct pt_regs
*regs
)
8757 return __perf_event_overflow(event
, 1, data
, regs
);
8761 * Generic software event infrastructure
8764 struct swevent_htable
{
8765 struct swevent_hlist
*swevent_hlist
;
8766 struct mutex hlist_mutex
;
8769 /* Recursion avoidance in each contexts */
8770 int recursion
[PERF_NR_CONTEXTS
];
8773 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
8776 * We directly increment event->count and keep a second value in
8777 * event->hw.period_left to count intervals. This period event
8778 * is kept in the range [-sample_period, 0] so that we can use the
8782 u64
perf_swevent_set_period(struct perf_event
*event
)
8784 struct hw_perf_event
*hwc
= &event
->hw
;
8785 u64 period
= hwc
->last_period
;
8789 hwc
->last_period
= hwc
->sample_period
;
8792 old
= val
= local64_read(&hwc
->period_left
);
8796 nr
= div64_u64(period
+ val
, period
);
8797 offset
= nr
* period
;
8799 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
8805 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
8806 struct perf_sample_data
*data
,
8807 struct pt_regs
*regs
)
8809 struct hw_perf_event
*hwc
= &event
->hw
;
8813 overflow
= perf_swevent_set_period(event
);
8815 if (hwc
->interrupts
== MAX_INTERRUPTS
)
8818 for (; overflow
; overflow
--) {
8819 if (__perf_event_overflow(event
, throttle
,
8822 * We inhibit the overflow from happening when
8823 * hwc->interrupts == MAX_INTERRUPTS.
8831 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
8832 struct perf_sample_data
*data
,
8833 struct pt_regs
*regs
)
8835 struct hw_perf_event
*hwc
= &event
->hw
;
8837 local64_add(nr
, &event
->count
);
8842 if (!is_sampling_event(event
))
8845 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
8847 return perf_swevent_overflow(event
, 1, data
, regs
);
8849 data
->period
= event
->hw
.last_period
;
8851 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
8852 return perf_swevent_overflow(event
, 1, data
, regs
);
8854 if (local64_add_negative(nr
, &hwc
->period_left
))
8857 perf_swevent_overflow(event
, 0, data
, regs
);
8860 static int perf_exclude_event(struct perf_event
*event
,
8861 struct pt_regs
*regs
)
8863 if (event
->hw
.state
& PERF_HES_STOPPED
)
8867 if (event
->attr
.exclude_user
&& user_mode(regs
))
8870 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
8877 static int perf_swevent_match(struct perf_event
*event
,
8878 enum perf_type_id type
,
8880 struct perf_sample_data
*data
,
8881 struct pt_regs
*regs
)
8883 if (event
->attr
.type
!= type
)
8886 if (event
->attr
.config
!= event_id
)
8889 if (perf_exclude_event(event
, regs
))
8895 static inline u64
swevent_hash(u64 type
, u32 event_id
)
8897 u64 val
= event_id
| (type
<< 32);
8899 return hash_64(val
, SWEVENT_HLIST_BITS
);
8902 static inline struct hlist_head
*
8903 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
8905 u64 hash
= swevent_hash(type
, event_id
);
8907 return &hlist
->heads
[hash
];
8910 /* For the read side: events when they trigger */
8911 static inline struct hlist_head
*
8912 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
8914 struct swevent_hlist
*hlist
;
8916 hlist
= rcu_dereference(swhash
->swevent_hlist
);
8920 return __find_swevent_head(hlist
, type
, event_id
);
8923 /* For the event head insertion and removal in the hlist */
8924 static inline struct hlist_head
*
8925 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
8927 struct swevent_hlist
*hlist
;
8928 u32 event_id
= event
->attr
.config
;
8929 u64 type
= event
->attr
.type
;
8932 * Event scheduling is always serialized against hlist allocation
8933 * and release. Which makes the protected version suitable here.
8934 * The context lock guarantees that.
8936 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
8937 lockdep_is_held(&event
->ctx
->lock
));
8941 return __find_swevent_head(hlist
, type
, event_id
);
8944 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
8946 struct perf_sample_data
*data
,
8947 struct pt_regs
*regs
)
8949 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8950 struct perf_event
*event
;
8951 struct hlist_head
*head
;
8954 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
8958 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8959 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
8960 perf_swevent_event(event
, nr
, data
, regs
);
8966 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
8968 int perf_swevent_get_recursion_context(void)
8970 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8972 return get_recursion_context(swhash
->recursion
);
8974 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
8976 void perf_swevent_put_recursion_context(int rctx
)
8978 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8980 put_recursion_context(swhash
->recursion
, rctx
);
8983 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8985 struct perf_sample_data data
;
8987 if (WARN_ON_ONCE(!regs
))
8990 perf_sample_data_init(&data
, addr
, 0);
8991 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
8994 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8998 preempt_disable_notrace();
8999 rctx
= perf_swevent_get_recursion_context();
9000 if (unlikely(rctx
< 0))
9003 ___perf_sw_event(event_id
, nr
, regs
, addr
);
9005 perf_swevent_put_recursion_context(rctx
);
9007 preempt_enable_notrace();
9010 static void perf_swevent_read(struct perf_event
*event
)
9014 static int perf_swevent_add(struct perf_event
*event
, int flags
)
9016 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
9017 struct hw_perf_event
*hwc
= &event
->hw
;
9018 struct hlist_head
*head
;
9020 if (is_sampling_event(event
)) {
9021 hwc
->last_period
= hwc
->sample_period
;
9022 perf_swevent_set_period(event
);
9025 hwc
->state
= !(flags
& PERF_EF_START
);
9027 head
= find_swevent_head(swhash
, event
);
9028 if (WARN_ON_ONCE(!head
))
9031 hlist_add_head_rcu(&event
->hlist_entry
, head
);
9032 perf_event_update_userpage(event
);
9037 static void perf_swevent_del(struct perf_event
*event
, int flags
)
9039 hlist_del_rcu(&event
->hlist_entry
);
9042 static void perf_swevent_start(struct perf_event
*event
, int flags
)
9044 event
->hw
.state
= 0;
9047 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
9049 event
->hw
.state
= PERF_HES_STOPPED
;
9052 /* Deref the hlist from the update side */
9053 static inline struct swevent_hlist
*
9054 swevent_hlist_deref(struct swevent_htable
*swhash
)
9056 return rcu_dereference_protected(swhash
->swevent_hlist
,
9057 lockdep_is_held(&swhash
->hlist_mutex
));
9060 static void swevent_hlist_release(struct swevent_htable
*swhash
)
9062 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
9067 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
9068 kfree_rcu(hlist
, rcu_head
);
9071 static void swevent_hlist_put_cpu(int cpu
)
9073 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9075 mutex_lock(&swhash
->hlist_mutex
);
9077 if (!--swhash
->hlist_refcount
)
9078 swevent_hlist_release(swhash
);
9080 mutex_unlock(&swhash
->hlist_mutex
);
9083 static void swevent_hlist_put(void)
9087 for_each_possible_cpu(cpu
)
9088 swevent_hlist_put_cpu(cpu
);
9091 static int swevent_hlist_get_cpu(int cpu
)
9093 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9096 mutex_lock(&swhash
->hlist_mutex
);
9097 if (!swevent_hlist_deref(swhash
) &&
9098 cpumask_test_cpu(cpu
, perf_online_mask
)) {
9099 struct swevent_hlist
*hlist
;
9101 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
9106 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9108 swhash
->hlist_refcount
++;
9110 mutex_unlock(&swhash
->hlist_mutex
);
9115 static int swevent_hlist_get(void)
9117 int err
, cpu
, failed_cpu
;
9119 mutex_lock(&pmus_lock
);
9120 for_each_possible_cpu(cpu
) {
9121 err
= swevent_hlist_get_cpu(cpu
);
9127 mutex_unlock(&pmus_lock
);
9130 for_each_possible_cpu(cpu
) {
9131 if (cpu
== failed_cpu
)
9133 swevent_hlist_put_cpu(cpu
);
9135 mutex_unlock(&pmus_lock
);
9139 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
9141 static void sw_perf_event_destroy(struct perf_event
*event
)
9143 u64 event_id
= event
->attr
.config
;
9145 WARN_ON(event
->parent
);
9147 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
9148 swevent_hlist_put();
9151 static int perf_swevent_init(struct perf_event
*event
)
9153 u64 event_id
= event
->attr
.config
;
9155 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9159 * no branch sampling for software events
9161 if (has_branch_stack(event
))
9165 case PERF_COUNT_SW_CPU_CLOCK
:
9166 case PERF_COUNT_SW_TASK_CLOCK
:
9173 if (event_id
>= PERF_COUNT_SW_MAX
)
9176 if (!event
->parent
) {
9179 err
= swevent_hlist_get();
9183 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
9184 event
->destroy
= sw_perf_event_destroy
;
9190 static struct pmu perf_swevent
= {
9191 .task_ctx_nr
= perf_sw_context
,
9193 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9195 .event_init
= perf_swevent_init
,
9196 .add
= perf_swevent_add
,
9197 .del
= perf_swevent_del
,
9198 .start
= perf_swevent_start
,
9199 .stop
= perf_swevent_stop
,
9200 .read
= perf_swevent_read
,
9203 #ifdef CONFIG_EVENT_TRACING
9205 static int perf_tp_filter_match(struct perf_event
*event
,
9206 struct perf_sample_data
*data
)
9208 void *record
= data
->raw
->frag
.data
;
9210 /* only top level events have filters set */
9212 event
= event
->parent
;
9214 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
9219 static int perf_tp_event_match(struct perf_event
*event
,
9220 struct perf_sample_data
*data
,
9221 struct pt_regs
*regs
)
9223 if (event
->hw
.state
& PERF_HES_STOPPED
)
9226 * If exclude_kernel, only trace user-space tracepoints (uprobes)
9228 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
9231 if (!perf_tp_filter_match(event
, data
))
9237 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
9238 struct trace_event_call
*call
, u64 count
,
9239 struct pt_regs
*regs
, struct hlist_head
*head
,
9240 struct task_struct
*task
)
9242 if (bpf_prog_array_valid(call
)) {
9243 *(struct pt_regs
**)raw_data
= regs
;
9244 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
9245 perf_swevent_put_recursion_context(rctx
);
9249 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
9252 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
9254 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
9255 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
9256 struct task_struct
*task
)
9258 struct perf_sample_data data
;
9259 struct perf_event
*event
;
9261 struct perf_raw_record raw
= {
9268 perf_sample_data_init(&data
, 0, 0);
9271 perf_trace_buf_update(record
, event_type
);
9273 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
9274 if (perf_tp_event_match(event
, &data
, regs
))
9275 perf_swevent_event(event
, count
, &data
, regs
);
9279 * If we got specified a target task, also iterate its context and
9280 * deliver this event there too.
9282 if (task
&& task
!= current
) {
9283 struct perf_event_context
*ctx
;
9284 struct trace_entry
*entry
= record
;
9287 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
9291 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
9292 if (event
->cpu
!= smp_processor_id())
9294 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
9296 if (event
->attr
.config
!= entry
->type
)
9298 if (perf_tp_event_match(event
, &data
, regs
))
9299 perf_swevent_event(event
, count
, &data
, regs
);
9305 perf_swevent_put_recursion_context(rctx
);
9307 EXPORT_SYMBOL_GPL(perf_tp_event
);
9309 static void tp_perf_event_destroy(struct perf_event
*event
)
9311 perf_trace_destroy(event
);
9314 static int perf_tp_event_init(struct perf_event
*event
)
9318 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
9322 * no branch sampling for tracepoint events
9324 if (has_branch_stack(event
))
9327 err
= perf_trace_init(event
);
9331 event
->destroy
= tp_perf_event_destroy
;
9336 static struct pmu perf_tracepoint
= {
9337 .task_ctx_nr
= perf_sw_context
,
9339 .event_init
= perf_tp_event_init
,
9340 .add
= perf_trace_add
,
9341 .del
= perf_trace_del
,
9342 .start
= perf_swevent_start
,
9343 .stop
= perf_swevent_stop
,
9344 .read
= perf_swevent_read
,
9347 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
9349 * Flags in config, used by dynamic PMU kprobe and uprobe
9350 * The flags should match following PMU_FORMAT_ATTR().
9352 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
9353 * if not set, create kprobe/uprobe
9355 * The following values specify a reference counter (or semaphore in the
9356 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
9357 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
9359 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
9360 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
9362 enum perf_probe_config
{
9363 PERF_PROBE_CONFIG_IS_RETPROBE
= 1U << 0, /* [k,u]retprobe */
9364 PERF_UPROBE_REF_CTR_OFFSET_BITS
= 32,
9365 PERF_UPROBE_REF_CTR_OFFSET_SHIFT
= 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS
,
9368 PMU_FORMAT_ATTR(retprobe
, "config:0");
9371 #ifdef CONFIG_KPROBE_EVENTS
9372 static struct attribute
*kprobe_attrs
[] = {
9373 &format_attr_retprobe
.attr
,
9377 static struct attribute_group kprobe_format_group
= {
9379 .attrs
= kprobe_attrs
,
9382 static const struct attribute_group
*kprobe_attr_groups
[] = {
9383 &kprobe_format_group
,
9387 static int perf_kprobe_event_init(struct perf_event
*event
);
9388 static struct pmu perf_kprobe
= {
9389 .task_ctx_nr
= perf_sw_context
,
9390 .event_init
= perf_kprobe_event_init
,
9391 .add
= perf_trace_add
,
9392 .del
= perf_trace_del
,
9393 .start
= perf_swevent_start
,
9394 .stop
= perf_swevent_stop
,
9395 .read
= perf_swevent_read
,
9396 .attr_groups
= kprobe_attr_groups
,
9399 static int perf_kprobe_event_init(struct perf_event
*event
)
9404 if (event
->attr
.type
!= perf_kprobe
.type
)
9407 if (!capable(CAP_SYS_ADMIN
))
9411 * no branch sampling for probe events
9413 if (has_branch_stack(event
))
9416 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9417 err
= perf_kprobe_init(event
, is_retprobe
);
9421 event
->destroy
= perf_kprobe_destroy
;
9425 #endif /* CONFIG_KPROBE_EVENTS */
9427 #ifdef CONFIG_UPROBE_EVENTS
9428 PMU_FORMAT_ATTR(ref_ctr_offset
, "config:32-63");
9430 static struct attribute
*uprobe_attrs
[] = {
9431 &format_attr_retprobe
.attr
,
9432 &format_attr_ref_ctr_offset
.attr
,
9436 static struct attribute_group uprobe_format_group
= {
9438 .attrs
= uprobe_attrs
,
9441 static const struct attribute_group
*uprobe_attr_groups
[] = {
9442 &uprobe_format_group
,
9446 static int perf_uprobe_event_init(struct perf_event
*event
);
9447 static struct pmu perf_uprobe
= {
9448 .task_ctx_nr
= perf_sw_context
,
9449 .event_init
= perf_uprobe_event_init
,
9450 .add
= perf_trace_add
,
9451 .del
= perf_trace_del
,
9452 .start
= perf_swevent_start
,
9453 .stop
= perf_swevent_stop
,
9454 .read
= perf_swevent_read
,
9455 .attr_groups
= uprobe_attr_groups
,
9458 static int perf_uprobe_event_init(struct perf_event
*event
)
9461 unsigned long ref_ctr_offset
;
9464 if (event
->attr
.type
!= perf_uprobe
.type
)
9467 if (!capable(CAP_SYS_ADMIN
))
9471 * no branch sampling for probe events
9473 if (has_branch_stack(event
))
9476 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9477 ref_ctr_offset
= event
->attr
.config
>> PERF_UPROBE_REF_CTR_OFFSET_SHIFT
;
9478 err
= perf_uprobe_init(event
, ref_ctr_offset
, is_retprobe
);
9482 event
->destroy
= perf_uprobe_destroy
;
9486 #endif /* CONFIG_UPROBE_EVENTS */
9488 static inline void perf_tp_register(void)
9490 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
9491 #ifdef CONFIG_KPROBE_EVENTS
9492 perf_pmu_register(&perf_kprobe
, "kprobe", -1);
9494 #ifdef CONFIG_UPROBE_EVENTS
9495 perf_pmu_register(&perf_uprobe
, "uprobe", -1);
9499 static void perf_event_free_filter(struct perf_event
*event
)
9501 ftrace_profile_free_filter(event
);
9504 #ifdef CONFIG_BPF_SYSCALL
9505 static void bpf_overflow_handler(struct perf_event
*event
,
9506 struct perf_sample_data
*data
,
9507 struct pt_regs
*regs
)
9509 struct bpf_perf_event_data_kern ctx
= {
9515 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
9516 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
9519 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
9522 __this_cpu_dec(bpf_prog_active
);
9526 event
->orig_overflow_handler(event
, data
, regs
);
9529 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
9531 struct bpf_prog
*prog
;
9533 if (event
->overflow_handler_context
)
9534 /* hw breakpoint or kernel counter */
9540 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
9542 return PTR_ERR(prog
);
9545 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
9546 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
9550 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9552 struct bpf_prog
*prog
= event
->prog
;
9557 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
9562 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
9566 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9572 * returns true if the event is a tracepoint, or a kprobe/upprobe created
9573 * with perf_event_open()
9575 static inline bool perf_event_is_tracing(struct perf_event
*event
)
9577 if (event
->pmu
== &perf_tracepoint
)
9579 #ifdef CONFIG_KPROBE_EVENTS
9580 if (event
->pmu
== &perf_kprobe
)
9583 #ifdef CONFIG_UPROBE_EVENTS
9584 if (event
->pmu
== &perf_uprobe
)
9590 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9592 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
9593 struct bpf_prog
*prog
;
9596 if (!perf_event_is_tracing(event
))
9597 return perf_event_set_bpf_handler(event
, prog_fd
);
9599 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
9600 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
9601 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
9602 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
9603 /* bpf programs can only be attached to u/kprobe or tracepoint */
9606 prog
= bpf_prog_get(prog_fd
);
9608 return PTR_ERR(prog
);
9610 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
9611 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
9612 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
9613 /* valid fd, but invalid bpf program type */
9618 /* Kprobe override only works for kprobes, not uprobes. */
9619 if (prog
->kprobe_override
&&
9620 !(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
)) {
9625 if (is_tracepoint
|| is_syscall_tp
) {
9626 int off
= trace_event_get_offsets(event
->tp_event
);
9628 if (prog
->aux
->max_ctx_offset
> off
) {
9634 ret
= perf_event_attach_bpf_prog(event
, prog
);
9640 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9642 if (!perf_event_is_tracing(event
)) {
9643 perf_event_free_bpf_handler(event
);
9646 perf_event_detach_bpf_prog(event
);
9651 static inline void perf_tp_register(void)
9655 static void perf_event_free_filter(struct perf_event
*event
)
9659 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9664 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9667 #endif /* CONFIG_EVENT_TRACING */
9669 #ifdef CONFIG_HAVE_HW_BREAKPOINT
9670 void perf_bp_event(struct perf_event
*bp
, void *data
)
9672 struct perf_sample_data sample
;
9673 struct pt_regs
*regs
= data
;
9675 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
9677 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
9678 perf_swevent_event(bp
, 1, &sample
, regs
);
9683 * Allocate a new address filter
9685 static struct perf_addr_filter
*
9686 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
9688 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
9689 struct perf_addr_filter
*filter
;
9691 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
9695 INIT_LIST_HEAD(&filter
->entry
);
9696 list_add_tail(&filter
->entry
, filters
);
9701 static void free_filters_list(struct list_head
*filters
)
9703 struct perf_addr_filter
*filter
, *iter
;
9705 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
9706 path_put(&filter
->path
);
9707 list_del(&filter
->entry
);
9713 * Free existing address filters and optionally install new ones
9715 static void perf_addr_filters_splice(struct perf_event
*event
,
9716 struct list_head
*head
)
9718 unsigned long flags
;
9721 if (!has_addr_filter(event
))
9724 /* don't bother with children, they don't have their own filters */
9728 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
9730 list_splice_init(&event
->addr_filters
.list
, &list
);
9732 list_splice(head
, &event
->addr_filters
.list
);
9734 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
9736 free_filters_list(&list
);
9740 * Scan through mm's vmas and see if one of them matches the
9741 * @filter; if so, adjust filter's address range.
9742 * Called with mm::mmap_sem down for reading.
9744 static void perf_addr_filter_apply(struct perf_addr_filter
*filter
,
9745 struct mm_struct
*mm
,
9746 struct perf_addr_filter_range
*fr
)
9748 struct vm_area_struct
*vma
;
9750 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
9754 if (perf_addr_filter_vma_adjust(filter
, vma
, fr
))
9760 * Update event's address range filters based on the
9761 * task's existing mappings, if any.
9763 static void perf_event_addr_filters_apply(struct perf_event
*event
)
9765 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
9766 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
9767 struct perf_addr_filter
*filter
;
9768 struct mm_struct
*mm
= NULL
;
9769 unsigned int count
= 0;
9770 unsigned long flags
;
9773 * We may observe TASK_TOMBSTONE, which means that the event tear-down
9774 * will stop on the parent's child_mutex that our caller is also holding
9776 if (task
== TASK_TOMBSTONE
)
9779 if (ifh
->nr_file_filters
) {
9780 mm
= get_task_mm(event
->ctx
->task
);
9784 down_read(&mm
->mmap_sem
);
9787 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
9788 list_for_each_entry(filter
, &ifh
->list
, entry
) {
9789 if (filter
->path
.dentry
) {
9791 * Adjust base offset if the filter is associated to a
9792 * binary that needs to be mapped:
9794 event
->addr_filter_ranges
[count
].start
= 0;
9795 event
->addr_filter_ranges
[count
].size
= 0;
9797 perf_addr_filter_apply(filter
, mm
, &event
->addr_filter_ranges
[count
]);
9799 event
->addr_filter_ranges
[count
].start
= filter
->offset
;
9800 event
->addr_filter_ranges
[count
].size
= filter
->size
;
9806 event
->addr_filters_gen
++;
9807 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
9809 if (ifh
->nr_file_filters
) {
9810 up_read(&mm
->mmap_sem
);
9816 perf_event_stop(event
, 1);
9820 * Address range filtering: limiting the data to certain
9821 * instruction address ranges. Filters are ioctl()ed to us from
9822 * userspace as ascii strings.
9824 * Filter string format:
9827 * where ACTION is one of the
9828 * * "filter": limit the trace to this region
9829 * * "start": start tracing from this address
9830 * * "stop": stop tracing at this address/region;
9832 * * for kernel addresses: <start address>[/<size>]
9833 * * for object files: <start address>[/<size>]@</path/to/object/file>
9835 * if <size> is not specified or is zero, the range is treated as a single
9836 * address; not valid for ACTION=="filter".
9850 IF_STATE_ACTION
= 0,
9855 static const match_table_t if_tokens
= {
9856 { IF_ACT_FILTER
, "filter" },
9857 { IF_ACT_START
, "start" },
9858 { IF_ACT_STOP
, "stop" },
9859 { IF_SRC_FILE
, "%u/%u@%s" },
9860 { IF_SRC_KERNEL
, "%u/%u" },
9861 { IF_SRC_FILEADDR
, "%u@%s" },
9862 { IF_SRC_KERNELADDR
, "%u" },
9863 { IF_ACT_NONE
, NULL
},
9867 * Address filter string parser
9870 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
9871 struct list_head
*filters
)
9873 struct perf_addr_filter
*filter
= NULL
;
9874 char *start
, *orig
, *filename
= NULL
;
9875 substring_t args
[MAX_OPT_ARGS
];
9876 int state
= IF_STATE_ACTION
, token
;
9877 unsigned int kernel
= 0;
9880 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
9884 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
9885 static const enum perf_addr_filter_action_t actions
[] = {
9886 [IF_ACT_FILTER
] = PERF_ADDR_FILTER_ACTION_FILTER
,
9887 [IF_ACT_START
] = PERF_ADDR_FILTER_ACTION_START
,
9888 [IF_ACT_STOP
] = PERF_ADDR_FILTER_ACTION_STOP
,
9895 /* filter definition begins */
9896 if (state
== IF_STATE_ACTION
) {
9897 filter
= perf_addr_filter_new(event
, filters
);
9902 token
= match_token(start
, if_tokens
, args
);
9907 if (state
!= IF_STATE_ACTION
)
9910 filter
->action
= actions
[token
];
9911 state
= IF_STATE_SOURCE
;
9914 case IF_SRC_KERNELADDR
:
9919 case IF_SRC_FILEADDR
:
9921 if (state
!= IF_STATE_SOURCE
)
9925 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
9929 if (token
== IF_SRC_KERNEL
|| token
== IF_SRC_FILE
) {
9931 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
9936 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
9937 int fpos
= token
== IF_SRC_FILE
? 2 : 1;
9939 filename
= match_strdup(&args
[fpos
]);
9946 state
= IF_STATE_END
;
9954 * Filter definition is fully parsed, validate and install it.
9955 * Make sure that it doesn't contradict itself or the event's
9958 if (state
== IF_STATE_END
) {
9960 if (kernel
&& event
->attr
.exclude_kernel
)
9964 * ACTION "filter" must have a non-zero length region
9967 if (filter
->action
== PERF_ADDR_FILTER_ACTION_FILTER
&&
9976 * For now, we only support file-based filters
9977 * in per-task events; doing so for CPU-wide
9978 * events requires additional context switching
9979 * trickery, since same object code will be
9980 * mapped at different virtual addresses in
9981 * different processes.
9984 if (!event
->ctx
->task
)
9985 goto fail_free_name
;
9987 /* look up the path and grab its inode */
9988 ret
= kern_path(filename
, LOOKUP_FOLLOW
,
9991 goto fail_free_name
;
9997 if (!filter
->path
.dentry
||
9998 !S_ISREG(d_inode(filter
->path
.dentry
)
10002 event
->addr_filters
.nr_file_filters
++;
10005 /* ready to consume more filters */
10006 state
= IF_STATE_ACTION
;
10011 if (state
!= IF_STATE_ACTION
)
10021 free_filters_list(filters
);
10028 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
10030 LIST_HEAD(filters
);
10034 * Since this is called in perf_ioctl() path, we're already holding
10037 lockdep_assert_held(&event
->ctx
->mutex
);
10039 if (WARN_ON_ONCE(event
->parent
))
10042 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
10044 goto fail_clear_files
;
10046 ret
= event
->pmu
->addr_filters_validate(&filters
);
10048 goto fail_free_filters
;
10050 /* remove existing filters, if any */
10051 perf_addr_filters_splice(event
, &filters
);
10053 /* install new filters */
10054 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
10059 free_filters_list(&filters
);
10062 event
->addr_filters
.nr_file_filters
= 0;
10067 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
10072 filter_str
= strndup_user(arg
, PAGE_SIZE
);
10073 if (IS_ERR(filter_str
))
10074 return PTR_ERR(filter_str
);
10076 #ifdef CONFIG_EVENT_TRACING
10077 if (perf_event_is_tracing(event
)) {
10078 struct perf_event_context
*ctx
= event
->ctx
;
10081 * Beware, here be dragons!!
10083 * the tracepoint muck will deadlock against ctx->mutex, but
10084 * the tracepoint stuff does not actually need it. So
10085 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
10086 * already have a reference on ctx.
10088 * This can result in event getting moved to a different ctx,
10089 * but that does not affect the tracepoint state.
10091 mutex_unlock(&ctx
->mutex
);
10092 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
10093 mutex_lock(&ctx
->mutex
);
10096 if (has_addr_filter(event
))
10097 ret
= perf_event_set_addr_filter(event
, filter_str
);
10104 * hrtimer based swevent callback
10107 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
10109 enum hrtimer_restart ret
= HRTIMER_RESTART
;
10110 struct perf_sample_data data
;
10111 struct pt_regs
*regs
;
10112 struct perf_event
*event
;
10115 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
10117 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
10118 return HRTIMER_NORESTART
;
10120 event
->pmu
->read(event
);
10122 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
10123 regs
= get_irq_regs();
10125 if (regs
&& !perf_exclude_event(event
, regs
)) {
10126 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
10127 if (__perf_event_overflow(event
, 1, &data
, regs
))
10128 ret
= HRTIMER_NORESTART
;
10131 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
10132 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
10137 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
10139 struct hw_perf_event
*hwc
= &event
->hw
;
10142 if (!is_sampling_event(event
))
10145 period
= local64_read(&hwc
->period_left
);
10150 local64_set(&hwc
->period_left
, 0);
10152 period
= max_t(u64
, 10000, hwc
->sample_period
);
10154 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
10155 HRTIMER_MODE_REL_PINNED_HARD
);
10158 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
10160 struct hw_perf_event
*hwc
= &event
->hw
;
10162 if (is_sampling_event(event
)) {
10163 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
10164 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
10166 hrtimer_cancel(&hwc
->hrtimer
);
10170 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
10172 struct hw_perf_event
*hwc
= &event
->hw
;
10174 if (!is_sampling_event(event
))
10177 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_HARD
);
10178 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
10181 * Since hrtimers have a fixed rate, we can do a static freq->period
10182 * mapping and avoid the whole period adjust feedback stuff.
10184 if (event
->attr
.freq
) {
10185 long freq
= event
->attr
.sample_freq
;
10187 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
10188 hwc
->sample_period
= event
->attr
.sample_period
;
10189 local64_set(&hwc
->period_left
, hwc
->sample_period
);
10190 hwc
->last_period
= hwc
->sample_period
;
10191 event
->attr
.freq
= 0;
10196 * Software event: cpu wall time clock
10199 static void cpu_clock_event_update(struct perf_event
*event
)
10204 now
= local_clock();
10205 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
10206 local64_add(now
- prev
, &event
->count
);
10209 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
10211 local64_set(&event
->hw
.prev_count
, local_clock());
10212 perf_swevent_start_hrtimer(event
);
10215 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
10217 perf_swevent_cancel_hrtimer(event
);
10218 cpu_clock_event_update(event
);
10221 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
10223 if (flags
& PERF_EF_START
)
10224 cpu_clock_event_start(event
, flags
);
10225 perf_event_update_userpage(event
);
10230 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
10232 cpu_clock_event_stop(event
, flags
);
10235 static void cpu_clock_event_read(struct perf_event
*event
)
10237 cpu_clock_event_update(event
);
10240 static int cpu_clock_event_init(struct perf_event
*event
)
10242 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
10245 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
10249 * no branch sampling for software events
10251 if (has_branch_stack(event
))
10252 return -EOPNOTSUPP
;
10254 perf_swevent_init_hrtimer(event
);
10259 static struct pmu perf_cpu_clock
= {
10260 .task_ctx_nr
= perf_sw_context
,
10262 .capabilities
= PERF_PMU_CAP_NO_NMI
,
10264 .event_init
= cpu_clock_event_init
,
10265 .add
= cpu_clock_event_add
,
10266 .del
= cpu_clock_event_del
,
10267 .start
= cpu_clock_event_start
,
10268 .stop
= cpu_clock_event_stop
,
10269 .read
= cpu_clock_event_read
,
10273 * Software event: task time clock
10276 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
10281 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
10282 delta
= now
- prev
;
10283 local64_add(delta
, &event
->count
);
10286 static void task_clock_event_start(struct perf_event
*event
, int flags
)
10288 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
10289 perf_swevent_start_hrtimer(event
);
10292 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
10294 perf_swevent_cancel_hrtimer(event
);
10295 task_clock_event_update(event
, event
->ctx
->time
);
10298 static int task_clock_event_add(struct perf_event
*event
, int flags
)
10300 if (flags
& PERF_EF_START
)
10301 task_clock_event_start(event
, flags
);
10302 perf_event_update_userpage(event
);
10307 static void task_clock_event_del(struct perf_event
*event
, int flags
)
10309 task_clock_event_stop(event
, PERF_EF_UPDATE
);
10312 static void task_clock_event_read(struct perf_event
*event
)
10314 u64 now
= perf_clock();
10315 u64 delta
= now
- event
->ctx
->timestamp
;
10316 u64 time
= event
->ctx
->time
+ delta
;
10318 task_clock_event_update(event
, time
);
10321 static int task_clock_event_init(struct perf_event
*event
)
10323 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
10326 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
10330 * no branch sampling for software events
10332 if (has_branch_stack(event
))
10333 return -EOPNOTSUPP
;
10335 perf_swevent_init_hrtimer(event
);
10340 static struct pmu perf_task_clock
= {
10341 .task_ctx_nr
= perf_sw_context
,
10343 .capabilities
= PERF_PMU_CAP_NO_NMI
,
10345 .event_init
= task_clock_event_init
,
10346 .add
= task_clock_event_add
,
10347 .del
= task_clock_event_del
,
10348 .start
= task_clock_event_start
,
10349 .stop
= task_clock_event_stop
,
10350 .read
= task_clock_event_read
,
10353 static void perf_pmu_nop_void(struct pmu
*pmu
)
10357 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
10361 static int perf_pmu_nop_int(struct pmu
*pmu
)
10366 static int perf_event_nop_int(struct perf_event
*event
, u64 value
)
10371 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
10373 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
10375 __this_cpu_write(nop_txn_flags
, flags
);
10377 if (flags
& ~PERF_PMU_TXN_ADD
)
10380 perf_pmu_disable(pmu
);
10383 static int perf_pmu_commit_txn(struct pmu
*pmu
)
10385 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10387 __this_cpu_write(nop_txn_flags
, 0);
10389 if (flags
& ~PERF_PMU_TXN_ADD
)
10392 perf_pmu_enable(pmu
);
10396 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
10398 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10400 __this_cpu_write(nop_txn_flags
, 0);
10402 if (flags
& ~PERF_PMU_TXN_ADD
)
10405 perf_pmu_enable(pmu
);
10408 static int perf_event_idx_default(struct perf_event
*event
)
10414 * Ensures all contexts with the same task_ctx_nr have the same
10415 * pmu_cpu_context too.
10417 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
10424 list_for_each_entry(pmu
, &pmus
, entry
) {
10425 if (pmu
->task_ctx_nr
== ctxn
)
10426 return pmu
->pmu_cpu_context
;
10432 static void free_pmu_context(struct pmu
*pmu
)
10435 * Static contexts such as perf_sw_context have a global lifetime
10436 * and may be shared between different PMUs. Avoid freeing them
10437 * when a single PMU is going away.
10439 if (pmu
->task_ctx_nr
> perf_invalid_context
)
10442 free_percpu(pmu
->pmu_cpu_context
);
10446 * Let userspace know that this PMU supports address range filtering:
10448 static ssize_t
nr_addr_filters_show(struct device
*dev
,
10449 struct device_attribute
*attr
,
10452 struct pmu
*pmu
= dev_get_drvdata(dev
);
10454 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
10456 DEVICE_ATTR_RO(nr_addr_filters
);
10458 static struct idr pmu_idr
;
10461 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
10463 struct pmu
*pmu
= dev_get_drvdata(dev
);
10465 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
10467 static DEVICE_ATTR_RO(type
);
10470 perf_event_mux_interval_ms_show(struct device
*dev
,
10471 struct device_attribute
*attr
,
10474 struct pmu
*pmu
= dev_get_drvdata(dev
);
10476 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
10479 static DEFINE_MUTEX(mux_interval_mutex
);
10482 perf_event_mux_interval_ms_store(struct device
*dev
,
10483 struct device_attribute
*attr
,
10484 const char *buf
, size_t count
)
10486 struct pmu
*pmu
= dev_get_drvdata(dev
);
10487 int timer
, cpu
, ret
;
10489 ret
= kstrtoint(buf
, 0, &timer
);
10496 /* same value, noting to do */
10497 if (timer
== pmu
->hrtimer_interval_ms
)
10500 mutex_lock(&mux_interval_mutex
);
10501 pmu
->hrtimer_interval_ms
= timer
;
10503 /* update all cpuctx for this PMU */
10505 for_each_online_cpu(cpu
) {
10506 struct perf_cpu_context
*cpuctx
;
10507 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10508 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
10510 cpu_function_call(cpu
,
10511 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
10513 cpus_read_unlock();
10514 mutex_unlock(&mux_interval_mutex
);
10518 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
10520 static struct attribute
*pmu_dev_attrs
[] = {
10521 &dev_attr_type
.attr
,
10522 &dev_attr_perf_event_mux_interval_ms
.attr
,
10525 ATTRIBUTE_GROUPS(pmu_dev
);
10527 static int pmu_bus_running
;
10528 static struct bus_type pmu_bus
= {
10529 .name
= "event_source",
10530 .dev_groups
= pmu_dev_groups
,
10533 static void pmu_dev_release(struct device
*dev
)
10538 static int pmu_dev_alloc(struct pmu
*pmu
)
10542 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
10546 pmu
->dev
->groups
= pmu
->attr_groups
;
10547 device_initialize(pmu
->dev
);
10548 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
10552 dev_set_drvdata(pmu
->dev
, pmu
);
10553 pmu
->dev
->bus
= &pmu_bus
;
10554 pmu
->dev
->release
= pmu_dev_release
;
10555 ret
= device_add(pmu
->dev
);
10559 /* For PMUs with address filters, throw in an extra attribute: */
10560 if (pmu
->nr_addr_filters
)
10561 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10566 if (pmu
->attr_update
)
10567 ret
= sysfs_update_groups(&pmu
->dev
->kobj
, pmu
->attr_update
);
10576 device_del(pmu
->dev
);
10579 put_device(pmu
->dev
);
10583 static struct lock_class_key cpuctx_mutex
;
10584 static struct lock_class_key cpuctx_lock
;
10586 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
10588 int cpu
, ret
, max
= PERF_TYPE_MAX
;
10590 mutex_lock(&pmus_lock
);
10592 pmu
->pmu_disable_count
= alloc_percpu(int);
10593 if (!pmu
->pmu_disable_count
)
10601 if (type
!= PERF_TYPE_SOFTWARE
) {
10605 ret
= idr_alloc(&pmu_idr
, pmu
, max
, 0, GFP_KERNEL
);
10609 WARN_ON(type
>= 0 && ret
!= type
);
10615 if (pmu_bus_running
) {
10616 ret
= pmu_dev_alloc(pmu
);
10622 if (pmu
->task_ctx_nr
== perf_hw_context
) {
10623 static int hw_context_taken
= 0;
10626 * Other than systems with heterogeneous CPUs, it never makes
10627 * sense for two PMUs to share perf_hw_context. PMUs which are
10628 * uncore must use perf_invalid_context.
10630 if (WARN_ON_ONCE(hw_context_taken
&&
10631 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
10632 pmu
->task_ctx_nr
= perf_invalid_context
;
10634 hw_context_taken
= 1;
10637 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
10638 if (pmu
->pmu_cpu_context
)
10639 goto got_cpu_context
;
10642 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
10643 if (!pmu
->pmu_cpu_context
)
10646 for_each_possible_cpu(cpu
) {
10647 struct perf_cpu_context
*cpuctx
;
10649 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10650 __perf_event_init_context(&cpuctx
->ctx
);
10651 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
10652 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
10653 cpuctx
->ctx
.pmu
= pmu
;
10654 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
10656 __perf_mux_hrtimer_init(cpuctx
, cpu
);
10658 cpuctx
->heap_size
= ARRAY_SIZE(cpuctx
->heap_default
);
10659 cpuctx
->heap
= cpuctx
->heap_default
;
10663 if (!pmu
->start_txn
) {
10664 if (pmu
->pmu_enable
) {
10666 * If we have pmu_enable/pmu_disable calls, install
10667 * transaction stubs that use that to try and batch
10668 * hardware accesses.
10670 pmu
->start_txn
= perf_pmu_start_txn
;
10671 pmu
->commit_txn
= perf_pmu_commit_txn
;
10672 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
10674 pmu
->start_txn
= perf_pmu_nop_txn
;
10675 pmu
->commit_txn
= perf_pmu_nop_int
;
10676 pmu
->cancel_txn
= perf_pmu_nop_void
;
10680 if (!pmu
->pmu_enable
) {
10681 pmu
->pmu_enable
= perf_pmu_nop_void
;
10682 pmu
->pmu_disable
= perf_pmu_nop_void
;
10685 if (!pmu
->check_period
)
10686 pmu
->check_period
= perf_event_nop_int
;
10688 if (!pmu
->event_idx
)
10689 pmu
->event_idx
= perf_event_idx_default
;
10692 * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
10693 * since these cannot be in the IDR. This way the linear search
10694 * is fast, provided a valid software event is provided.
10696 if (type
== PERF_TYPE_SOFTWARE
|| !name
)
10697 list_add_rcu(&pmu
->entry
, &pmus
);
10699 list_add_tail_rcu(&pmu
->entry
, &pmus
);
10701 atomic_set(&pmu
->exclusive_cnt
, 0);
10704 mutex_unlock(&pmus_lock
);
10709 device_del(pmu
->dev
);
10710 put_device(pmu
->dev
);
10713 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
10714 idr_remove(&pmu_idr
, pmu
->type
);
10717 free_percpu(pmu
->pmu_disable_count
);
10720 EXPORT_SYMBOL_GPL(perf_pmu_register
);
10722 void perf_pmu_unregister(struct pmu
*pmu
)
10724 mutex_lock(&pmus_lock
);
10725 list_del_rcu(&pmu
->entry
);
10728 * We dereference the pmu list under both SRCU and regular RCU, so
10729 * synchronize against both of those.
10731 synchronize_srcu(&pmus_srcu
);
10734 free_percpu(pmu
->pmu_disable_count
);
10735 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
10736 idr_remove(&pmu_idr
, pmu
->type
);
10737 if (pmu_bus_running
) {
10738 if (pmu
->nr_addr_filters
)
10739 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10740 device_del(pmu
->dev
);
10741 put_device(pmu
->dev
);
10743 free_pmu_context(pmu
);
10744 mutex_unlock(&pmus_lock
);
10746 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
10748 static inline bool has_extended_regs(struct perf_event
*event
)
10750 return (event
->attr
.sample_regs_user
& PERF_REG_EXTENDED_MASK
) ||
10751 (event
->attr
.sample_regs_intr
& PERF_REG_EXTENDED_MASK
);
10754 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
10756 struct perf_event_context
*ctx
= NULL
;
10759 if (!try_module_get(pmu
->module
))
10763 * A number of pmu->event_init() methods iterate the sibling_list to,
10764 * for example, validate if the group fits on the PMU. Therefore,
10765 * if this is a sibling event, acquire the ctx->mutex to protect
10766 * the sibling_list.
10768 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
10770 * This ctx->mutex can nest when we're called through
10771 * inheritance. See the perf_event_ctx_lock_nested() comment.
10773 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
10774 SINGLE_DEPTH_NESTING
);
10779 ret
= pmu
->event_init(event
);
10782 perf_event_ctx_unlock(event
->group_leader
, ctx
);
10785 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXTENDED_REGS
) &&
10786 has_extended_regs(event
))
10789 if (pmu
->capabilities
& PERF_PMU_CAP_NO_EXCLUDE
&&
10790 event_has_any_exclude_flag(event
))
10793 if (ret
&& event
->destroy
)
10794 event
->destroy(event
);
10798 module_put(pmu
->module
);
10803 static struct pmu
*perf_init_event(struct perf_event
*event
)
10805 int idx
, type
, ret
;
10808 idx
= srcu_read_lock(&pmus_srcu
);
10810 /* Try parent's PMU first: */
10811 if (event
->parent
&& event
->parent
->pmu
) {
10812 pmu
= event
->parent
->pmu
;
10813 ret
= perf_try_init_event(pmu
, event
);
10819 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
10820 * are often aliases for PERF_TYPE_RAW.
10822 type
= event
->attr
.type
;
10823 if (type
== PERF_TYPE_HARDWARE
|| type
== PERF_TYPE_HW_CACHE
)
10824 type
= PERF_TYPE_RAW
;
10828 pmu
= idr_find(&pmu_idr
, type
);
10831 ret
= perf_try_init_event(pmu
, event
);
10832 if (ret
== -ENOENT
&& event
->attr
.type
!= type
) {
10833 type
= event
->attr
.type
;
10838 pmu
= ERR_PTR(ret
);
10843 list_for_each_entry_rcu(pmu
, &pmus
, entry
, lockdep_is_held(&pmus_srcu
)) {
10844 ret
= perf_try_init_event(pmu
, event
);
10848 if (ret
!= -ENOENT
) {
10849 pmu
= ERR_PTR(ret
);
10853 pmu
= ERR_PTR(-ENOENT
);
10855 srcu_read_unlock(&pmus_srcu
, idx
);
10860 static void attach_sb_event(struct perf_event
*event
)
10862 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
10864 raw_spin_lock(&pel
->lock
);
10865 list_add_rcu(&event
->sb_list
, &pel
->list
);
10866 raw_spin_unlock(&pel
->lock
);
10870 * We keep a list of all !task (and therefore per-cpu) events
10871 * that need to receive side-band records.
10873 * This avoids having to scan all the various PMU per-cpu contexts
10874 * looking for them.
10876 static void account_pmu_sb_event(struct perf_event
*event
)
10878 if (is_sb_event(event
))
10879 attach_sb_event(event
);
10882 static void account_event_cpu(struct perf_event
*event
, int cpu
)
10887 if (is_cgroup_event(event
))
10888 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
10891 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
10892 static void account_freq_event_nohz(void)
10894 #ifdef CONFIG_NO_HZ_FULL
10895 /* Lock so we don't race with concurrent unaccount */
10896 spin_lock(&nr_freq_lock
);
10897 if (atomic_inc_return(&nr_freq_events
) == 1)
10898 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
10899 spin_unlock(&nr_freq_lock
);
10903 static void account_freq_event(void)
10905 if (tick_nohz_full_enabled())
10906 account_freq_event_nohz();
10908 atomic_inc(&nr_freq_events
);
10912 static void account_event(struct perf_event
*event
)
10919 if (event
->attach_state
& PERF_ATTACH_TASK
)
10921 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
10922 atomic_inc(&nr_mmap_events
);
10923 if (event
->attr
.comm
)
10924 atomic_inc(&nr_comm_events
);
10925 if (event
->attr
.namespaces
)
10926 atomic_inc(&nr_namespaces_events
);
10927 if (event
->attr
.cgroup
)
10928 atomic_inc(&nr_cgroup_events
);
10929 if (event
->attr
.task
)
10930 atomic_inc(&nr_task_events
);
10931 if (event
->attr
.freq
)
10932 account_freq_event();
10933 if (event
->attr
.context_switch
) {
10934 atomic_inc(&nr_switch_events
);
10937 if (has_branch_stack(event
))
10939 if (is_cgroup_event(event
))
10941 if (event
->attr
.ksymbol
)
10942 atomic_inc(&nr_ksymbol_events
);
10943 if (event
->attr
.bpf_event
)
10944 atomic_inc(&nr_bpf_events
);
10948 * We need the mutex here because static_branch_enable()
10949 * must complete *before* the perf_sched_count increment
10952 if (atomic_inc_not_zero(&perf_sched_count
))
10955 mutex_lock(&perf_sched_mutex
);
10956 if (!atomic_read(&perf_sched_count
)) {
10957 static_branch_enable(&perf_sched_events
);
10959 * Guarantee that all CPUs observe they key change and
10960 * call the perf scheduling hooks before proceeding to
10961 * install events that need them.
10966 * Now that we have waited for the sync_sched(), allow further
10967 * increments to by-pass the mutex.
10969 atomic_inc(&perf_sched_count
);
10970 mutex_unlock(&perf_sched_mutex
);
10974 account_event_cpu(event
, event
->cpu
);
10976 account_pmu_sb_event(event
);
10980 * Allocate and initialize an event structure
10982 static struct perf_event
*
10983 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
10984 struct task_struct
*task
,
10985 struct perf_event
*group_leader
,
10986 struct perf_event
*parent_event
,
10987 perf_overflow_handler_t overflow_handler
,
10988 void *context
, int cgroup_fd
)
10991 struct perf_event
*event
;
10992 struct hw_perf_event
*hwc
;
10993 long err
= -EINVAL
;
10995 if ((unsigned)cpu
>= nr_cpu_ids
) {
10996 if (!task
|| cpu
!= -1)
10997 return ERR_PTR(-EINVAL
);
11000 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
11002 return ERR_PTR(-ENOMEM
);
11005 * Single events are their own group leaders, with an
11006 * empty sibling list:
11009 group_leader
= event
;
11011 mutex_init(&event
->child_mutex
);
11012 INIT_LIST_HEAD(&event
->child_list
);
11014 INIT_LIST_HEAD(&event
->event_entry
);
11015 INIT_LIST_HEAD(&event
->sibling_list
);
11016 INIT_LIST_HEAD(&event
->active_list
);
11017 init_event_group(event
);
11018 INIT_LIST_HEAD(&event
->rb_entry
);
11019 INIT_LIST_HEAD(&event
->active_entry
);
11020 INIT_LIST_HEAD(&event
->addr_filters
.list
);
11021 INIT_HLIST_NODE(&event
->hlist_entry
);
11024 init_waitqueue_head(&event
->waitq
);
11025 event
->pending_disable
= -1;
11026 init_irq_work(&event
->pending
, perf_pending_event
);
11028 mutex_init(&event
->mmap_mutex
);
11029 raw_spin_lock_init(&event
->addr_filters
.lock
);
11031 atomic_long_set(&event
->refcount
, 1);
11033 event
->attr
= *attr
;
11034 event
->group_leader
= group_leader
;
11038 event
->parent
= parent_event
;
11040 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
11041 event
->id
= atomic64_inc_return(&perf_event_id
);
11043 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11046 event
->attach_state
= PERF_ATTACH_TASK
;
11048 * XXX pmu::event_init needs to know what task to account to
11049 * and we cannot use the ctx information because we need the
11050 * pmu before we get a ctx.
11052 event
->hw
.target
= get_task_struct(task
);
11055 event
->clock
= &local_clock
;
11057 event
->clock
= parent_event
->clock
;
11059 if (!overflow_handler
&& parent_event
) {
11060 overflow_handler
= parent_event
->overflow_handler
;
11061 context
= parent_event
->overflow_handler_context
;
11062 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
11063 if (overflow_handler
== bpf_overflow_handler
) {
11064 struct bpf_prog
*prog
= parent_event
->prog
;
11066 bpf_prog_inc(prog
);
11067 event
->prog
= prog
;
11068 event
->orig_overflow_handler
=
11069 parent_event
->orig_overflow_handler
;
11074 if (overflow_handler
) {
11075 event
->overflow_handler
= overflow_handler
;
11076 event
->overflow_handler_context
= context
;
11077 } else if (is_write_backward(event
)){
11078 event
->overflow_handler
= perf_event_output_backward
;
11079 event
->overflow_handler_context
= NULL
;
11081 event
->overflow_handler
= perf_event_output_forward
;
11082 event
->overflow_handler_context
= NULL
;
11085 perf_event__state_init(event
);
11090 hwc
->sample_period
= attr
->sample_period
;
11091 if (attr
->freq
&& attr
->sample_freq
)
11092 hwc
->sample_period
= 1;
11093 hwc
->last_period
= hwc
->sample_period
;
11095 local64_set(&hwc
->period_left
, hwc
->sample_period
);
11098 * We currently do not support PERF_SAMPLE_READ on inherited events.
11099 * See perf_output_read().
11101 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
11104 if (!has_branch_stack(event
))
11105 event
->attr
.branch_sample_type
= 0;
11107 pmu
= perf_init_event(event
);
11109 err
= PTR_ERR(pmu
);
11114 * Disallow uncore-cgroup events, they don't make sense as the cgroup will
11115 * be different on other CPUs in the uncore mask.
11117 if (pmu
->task_ctx_nr
== perf_invalid_context
&& cgroup_fd
!= -1) {
11122 if (event
->attr
.aux_output
&&
11123 !(pmu
->capabilities
& PERF_PMU_CAP_AUX_OUTPUT
)) {
11128 if (cgroup_fd
!= -1) {
11129 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
11134 err
= exclusive_event_init(event
);
11138 if (has_addr_filter(event
)) {
11139 event
->addr_filter_ranges
= kcalloc(pmu
->nr_addr_filters
,
11140 sizeof(struct perf_addr_filter_range
),
11142 if (!event
->addr_filter_ranges
) {
11148 * Clone the parent's vma offsets: they are valid until exec()
11149 * even if the mm is not shared with the parent.
11151 if (event
->parent
) {
11152 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
11154 raw_spin_lock_irq(&ifh
->lock
);
11155 memcpy(event
->addr_filter_ranges
,
11156 event
->parent
->addr_filter_ranges
,
11157 pmu
->nr_addr_filters
* sizeof(struct perf_addr_filter_range
));
11158 raw_spin_unlock_irq(&ifh
->lock
);
11161 /* force hw sync on the address filters */
11162 event
->addr_filters_gen
= 1;
11165 if (!event
->parent
) {
11166 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
11167 err
= get_callchain_buffers(attr
->sample_max_stack
);
11169 goto err_addr_filters
;
11173 err
= security_perf_event_alloc(event
);
11175 goto err_callchain_buffer
;
11177 /* symmetric to unaccount_event() in _free_event() */
11178 account_event(event
);
11182 err_callchain_buffer
:
11183 if (!event
->parent
) {
11184 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
11185 put_callchain_buffers();
11188 kfree(event
->addr_filter_ranges
);
11191 exclusive_event_destroy(event
);
11194 if (is_cgroup_event(event
))
11195 perf_detach_cgroup(event
);
11196 if (event
->destroy
)
11197 event
->destroy(event
);
11198 module_put(pmu
->module
);
11201 put_pid_ns(event
->ns
);
11202 if (event
->hw
.target
)
11203 put_task_struct(event
->hw
.target
);
11206 return ERR_PTR(err
);
11209 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
11210 struct perf_event_attr
*attr
)
11215 /* Zero the full structure, so that a short copy will be nice. */
11216 memset(attr
, 0, sizeof(*attr
));
11218 ret
= get_user(size
, &uattr
->size
);
11222 /* ABI compatibility quirk: */
11224 size
= PERF_ATTR_SIZE_VER0
;
11225 if (size
< PERF_ATTR_SIZE_VER0
|| size
> PAGE_SIZE
)
11228 ret
= copy_struct_from_user(attr
, sizeof(*attr
), uattr
, size
);
11237 if (attr
->__reserved_1
|| attr
->__reserved_2
|| attr
->__reserved_3
)
11240 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
11243 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
11246 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
11247 u64 mask
= attr
->branch_sample_type
;
11249 /* only using defined bits */
11250 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
11253 /* at least one branch bit must be set */
11254 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
11257 /* propagate priv level, when not set for branch */
11258 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
11260 /* exclude_kernel checked on syscall entry */
11261 if (!attr
->exclude_kernel
)
11262 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
11264 if (!attr
->exclude_user
)
11265 mask
|= PERF_SAMPLE_BRANCH_USER
;
11267 if (!attr
->exclude_hv
)
11268 mask
|= PERF_SAMPLE_BRANCH_HV
;
11270 * adjust user setting (for HW filter setup)
11272 attr
->branch_sample_type
= mask
;
11274 /* privileged levels capture (kernel, hv): check permissions */
11275 if (mask
& PERF_SAMPLE_BRANCH_PERM_PLM
) {
11276 ret
= perf_allow_kernel(attr
);
11282 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
11283 ret
= perf_reg_validate(attr
->sample_regs_user
);
11288 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
11289 if (!arch_perf_have_user_stack_dump())
11293 * We have __u32 type for the size, but so far
11294 * we can only use __u16 as maximum due to the
11295 * __u16 sample size limit.
11297 if (attr
->sample_stack_user
>= USHRT_MAX
)
11299 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
11303 if (!attr
->sample_max_stack
)
11304 attr
->sample_max_stack
= sysctl_perf_event_max_stack
;
11306 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
11307 ret
= perf_reg_validate(attr
->sample_regs_intr
);
11309 #ifndef CONFIG_CGROUP_PERF
11310 if (attr
->sample_type
& PERF_SAMPLE_CGROUP
)
11318 put_user(sizeof(*attr
), &uattr
->size
);
11324 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
11326 struct perf_buffer
*rb
= NULL
;
11332 /* don't allow circular references */
11333 if (event
== output_event
)
11337 * Don't allow cross-cpu buffers
11339 if (output_event
->cpu
!= event
->cpu
)
11343 * If its not a per-cpu rb, it must be the same task.
11345 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
11349 * Mixing clocks in the same buffer is trouble you don't need.
11351 if (output_event
->clock
!= event
->clock
)
11355 * Either writing ring buffer from beginning or from end.
11356 * Mixing is not allowed.
11358 if (is_write_backward(output_event
) != is_write_backward(event
))
11362 * If both events generate aux data, they must be on the same PMU
11364 if (has_aux(event
) && has_aux(output_event
) &&
11365 event
->pmu
!= output_event
->pmu
)
11369 mutex_lock(&event
->mmap_mutex
);
11370 /* Can't redirect output if we've got an active mmap() */
11371 if (atomic_read(&event
->mmap_count
))
11374 if (output_event
) {
11375 /* get the rb we want to redirect to */
11376 rb
= ring_buffer_get(output_event
);
11381 ring_buffer_attach(event
, rb
);
11385 mutex_unlock(&event
->mmap_mutex
);
11391 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
11397 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
11400 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
11402 bool nmi_safe
= false;
11405 case CLOCK_MONOTONIC
:
11406 event
->clock
= &ktime_get_mono_fast_ns
;
11410 case CLOCK_MONOTONIC_RAW
:
11411 event
->clock
= &ktime_get_raw_fast_ns
;
11415 case CLOCK_REALTIME
:
11416 event
->clock
= &ktime_get_real_ns
;
11419 case CLOCK_BOOTTIME
:
11420 event
->clock
= &ktime_get_boottime_ns
;
11424 event
->clock
= &ktime_get_clocktai_ns
;
11431 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
11438 * Variation on perf_event_ctx_lock_nested(), except we take two context
11441 static struct perf_event_context
*
11442 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
11443 struct perf_event_context
*ctx
)
11445 struct perf_event_context
*gctx
;
11449 gctx
= READ_ONCE(group_leader
->ctx
);
11450 if (!refcount_inc_not_zero(&gctx
->refcount
)) {
11456 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
11458 if (group_leader
->ctx
!= gctx
) {
11459 mutex_unlock(&ctx
->mutex
);
11460 mutex_unlock(&gctx
->mutex
);
11469 * sys_perf_event_open - open a performance event, associate it to a task/cpu
11471 * @attr_uptr: event_id type attributes for monitoring/sampling
11474 * @group_fd: group leader event fd
11476 SYSCALL_DEFINE5(perf_event_open
,
11477 struct perf_event_attr __user
*, attr_uptr
,
11478 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
11480 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
11481 struct perf_event
*event
, *sibling
;
11482 struct perf_event_attr attr
;
11483 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
11484 struct file
*event_file
= NULL
;
11485 struct fd group
= {NULL
, 0};
11486 struct task_struct
*task
= NULL
;
11489 int move_group
= 0;
11491 int f_flags
= O_RDWR
;
11492 int cgroup_fd
= -1;
11494 /* for future expandability... */
11495 if (flags
& ~PERF_FLAG_ALL
)
11498 /* Do we allow access to perf_event_open(2) ? */
11499 err
= security_perf_event_open(&attr
, PERF_SECURITY_OPEN
);
11503 err
= perf_copy_attr(attr_uptr
, &attr
);
11507 if (!attr
.exclude_kernel
) {
11508 err
= perf_allow_kernel(&attr
);
11513 if (attr
.namespaces
) {
11514 if (!capable(CAP_SYS_ADMIN
))
11519 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
11522 if (attr
.sample_period
& (1ULL << 63))
11526 /* Only privileged users can get physical addresses */
11527 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
)) {
11528 err
= perf_allow_kernel(&attr
);
11533 err
= security_locked_down(LOCKDOWN_PERF
);
11534 if (err
&& (attr
.sample_type
& PERF_SAMPLE_REGS_INTR
))
11535 /* REGS_INTR can leak data, lockdown must prevent this */
11541 * In cgroup mode, the pid argument is used to pass the fd
11542 * opened to the cgroup directory in cgroupfs. The cpu argument
11543 * designates the cpu on which to monitor threads from that
11546 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
11549 if (flags
& PERF_FLAG_FD_CLOEXEC
)
11550 f_flags
|= O_CLOEXEC
;
11552 event_fd
= get_unused_fd_flags(f_flags
);
11556 if (group_fd
!= -1) {
11557 err
= perf_fget_light(group_fd
, &group
);
11560 group_leader
= group
.file
->private_data
;
11561 if (flags
& PERF_FLAG_FD_OUTPUT
)
11562 output_event
= group_leader
;
11563 if (flags
& PERF_FLAG_FD_NO_GROUP
)
11564 group_leader
= NULL
;
11567 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
11568 task
= find_lively_task_by_vpid(pid
);
11569 if (IS_ERR(task
)) {
11570 err
= PTR_ERR(task
);
11575 if (task
&& group_leader
&&
11576 group_leader
->attr
.inherit
!= attr
.inherit
) {
11582 err
= mutex_lock_interruptible(&task
->signal
->exec_update_mutex
);
11587 * Reuse ptrace permission checks for now.
11589 * We must hold exec_update_mutex across this and any potential
11590 * perf_install_in_context() call for this new event to
11591 * serialize against exec() altering our credentials (and the
11592 * perf_event_exit_task() that could imply).
11595 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
11599 if (flags
& PERF_FLAG_PID_CGROUP
)
11602 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
11603 NULL
, NULL
, cgroup_fd
);
11604 if (IS_ERR(event
)) {
11605 err
= PTR_ERR(event
);
11609 if (is_sampling_event(event
)) {
11610 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
11617 * Special case software events and allow them to be part of
11618 * any hardware group.
11622 if (attr
.use_clockid
) {
11623 err
= perf_event_set_clock(event
, attr
.clockid
);
11628 if (pmu
->task_ctx_nr
== perf_sw_context
)
11629 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
11631 if (group_leader
) {
11632 if (is_software_event(event
) &&
11633 !in_software_context(group_leader
)) {
11635 * If the event is a sw event, but the group_leader
11636 * is on hw context.
11638 * Allow the addition of software events to hw
11639 * groups, this is safe because software events
11640 * never fail to schedule.
11642 pmu
= group_leader
->ctx
->pmu
;
11643 } else if (!is_software_event(event
) &&
11644 is_software_event(group_leader
) &&
11645 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11647 * In case the group is a pure software group, and we
11648 * try to add a hardware event, move the whole group to
11649 * the hardware context.
11656 * Get the target context (task or percpu):
11658 ctx
= find_get_context(pmu
, task
, event
);
11660 err
= PTR_ERR(ctx
);
11665 * Look up the group leader (we will attach this event to it):
11667 if (group_leader
) {
11671 * Do not allow a recursive hierarchy (this new sibling
11672 * becoming part of another group-sibling):
11674 if (group_leader
->group_leader
!= group_leader
)
11677 /* All events in a group should have the same clock */
11678 if (group_leader
->clock
!= event
->clock
)
11682 * Make sure we're both events for the same CPU;
11683 * grouping events for different CPUs is broken; since
11684 * you can never concurrently schedule them anyhow.
11686 if (group_leader
->cpu
!= event
->cpu
)
11690 * Make sure we're both on the same task, or both
11693 if (group_leader
->ctx
->task
!= ctx
->task
)
11697 * Do not allow to attach to a group in a different task
11698 * or CPU context. If we're moving SW events, we'll fix
11699 * this up later, so allow that.
11701 if (!move_group
&& group_leader
->ctx
!= ctx
)
11705 * Only a group leader can be exclusive or pinned
11707 if (attr
.exclusive
|| attr
.pinned
)
11711 if (output_event
) {
11712 err
= perf_event_set_output(event
, output_event
);
11717 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
11719 if (IS_ERR(event_file
)) {
11720 err
= PTR_ERR(event_file
);
11726 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
11728 if (gctx
->task
== TASK_TOMBSTONE
) {
11734 * Check if we raced against another sys_perf_event_open() call
11735 * moving the software group underneath us.
11737 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11739 * If someone moved the group out from under us, check
11740 * if this new event wound up on the same ctx, if so
11741 * its the regular !move_group case, otherwise fail.
11747 perf_event_ctx_unlock(group_leader
, gctx
);
11753 * Failure to create exclusive events returns -EBUSY.
11756 if (!exclusive_event_installable(group_leader
, ctx
))
11759 for_each_sibling_event(sibling
, group_leader
) {
11760 if (!exclusive_event_installable(sibling
, ctx
))
11764 mutex_lock(&ctx
->mutex
);
11767 if (ctx
->task
== TASK_TOMBSTONE
) {
11772 if (!perf_event_validate_size(event
)) {
11779 * Check if the @cpu we're creating an event for is online.
11781 * We use the perf_cpu_context::ctx::mutex to serialize against
11782 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11784 struct perf_cpu_context
*cpuctx
=
11785 container_of(ctx
, struct perf_cpu_context
, ctx
);
11787 if (!cpuctx
->online
) {
11793 if (perf_need_aux_event(event
) && !perf_get_aux_event(event
, group_leader
)) {
11799 * Must be under the same ctx::mutex as perf_install_in_context(),
11800 * because we need to serialize with concurrent event creation.
11802 if (!exclusive_event_installable(event
, ctx
)) {
11807 WARN_ON_ONCE(ctx
->parent_ctx
);
11810 * This is the point on no return; we cannot fail hereafter. This is
11811 * where we start modifying current state.
11816 * See perf_event_ctx_lock() for comments on the details
11817 * of swizzling perf_event::ctx.
11819 perf_remove_from_context(group_leader
, 0);
11822 for_each_sibling_event(sibling
, group_leader
) {
11823 perf_remove_from_context(sibling
, 0);
11828 * Wait for everybody to stop referencing the events through
11829 * the old lists, before installing it on new lists.
11834 * Install the group siblings before the group leader.
11836 * Because a group leader will try and install the entire group
11837 * (through the sibling list, which is still in-tact), we can
11838 * end up with siblings installed in the wrong context.
11840 * By installing siblings first we NO-OP because they're not
11841 * reachable through the group lists.
11843 for_each_sibling_event(sibling
, group_leader
) {
11844 perf_event__state_init(sibling
);
11845 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
11850 * Removing from the context ends up with disabled
11851 * event. What we want here is event in the initial
11852 * startup state, ready to be add into new context.
11854 perf_event__state_init(group_leader
);
11855 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
11860 * Precalculate sample_data sizes; do while holding ctx::mutex such
11861 * that we're serialized against further additions and before
11862 * perf_install_in_context() which is the point the event is active and
11863 * can use these values.
11865 perf_event__header_size(event
);
11866 perf_event__id_header_size(event
);
11868 event
->owner
= current
;
11870 perf_install_in_context(ctx
, event
, event
->cpu
);
11871 perf_unpin_context(ctx
);
11874 perf_event_ctx_unlock(group_leader
, gctx
);
11875 mutex_unlock(&ctx
->mutex
);
11878 mutex_unlock(&task
->signal
->exec_update_mutex
);
11879 put_task_struct(task
);
11882 mutex_lock(¤t
->perf_event_mutex
);
11883 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
11884 mutex_unlock(¤t
->perf_event_mutex
);
11887 * Drop the reference on the group_event after placing the
11888 * new event on the sibling_list. This ensures destruction
11889 * of the group leader will find the pointer to itself in
11890 * perf_group_detach().
11893 fd_install(event_fd
, event_file
);
11898 perf_event_ctx_unlock(group_leader
, gctx
);
11899 mutex_unlock(&ctx
->mutex
);
11903 perf_unpin_context(ctx
);
11907 * If event_file is set, the fput() above will have called ->release()
11908 * and that will take care of freeing the event.
11914 mutex_unlock(&task
->signal
->exec_update_mutex
);
11917 put_task_struct(task
);
11921 put_unused_fd(event_fd
);
11926 * perf_event_create_kernel_counter
11928 * @attr: attributes of the counter to create
11929 * @cpu: cpu in which the counter is bound
11930 * @task: task to profile (NULL for percpu)
11932 struct perf_event
*
11933 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
11934 struct task_struct
*task
,
11935 perf_overflow_handler_t overflow_handler
,
11938 struct perf_event_context
*ctx
;
11939 struct perf_event
*event
;
11943 * Grouping is not supported for kernel events, neither is 'AUX',
11944 * make sure the caller's intentions are adjusted.
11946 if (attr
->aux_output
)
11947 return ERR_PTR(-EINVAL
);
11949 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
11950 overflow_handler
, context
, -1);
11951 if (IS_ERR(event
)) {
11952 err
= PTR_ERR(event
);
11956 /* Mark owner so we could distinguish it from user events. */
11957 event
->owner
= TASK_TOMBSTONE
;
11960 * Get the target context (task or percpu):
11962 ctx
= find_get_context(event
->pmu
, task
, event
);
11964 err
= PTR_ERR(ctx
);
11968 WARN_ON_ONCE(ctx
->parent_ctx
);
11969 mutex_lock(&ctx
->mutex
);
11970 if (ctx
->task
== TASK_TOMBSTONE
) {
11977 * Check if the @cpu we're creating an event for is online.
11979 * We use the perf_cpu_context::ctx::mutex to serialize against
11980 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11982 struct perf_cpu_context
*cpuctx
=
11983 container_of(ctx
, struct perf_cpu_context
, ctx
);
11984 if (!cpuctx
->online
) {
11990 if (!exclusive_event_installable(event
, ctx
)) {
11995 perf_install_in_context(ctx
, event
, event
->cpu
);
11996 perf_unpin_context(ctx
);
11997 mutex_unlock(&ctx
->mutex
);
12002 mutex_unlock(&ctx
->mutex
);
12003 perf_unpin_context(ctx
);
12008 return ERR_PTR(err
);
12010 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
12012 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
12014 struct perf_event_context
*src_ctx
;
12015 struct perf_event_context
*dst_ctx
;
12016 struct perf_event
*event
, *tmp
;
12019 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
12020 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
12023 * See perf_event_ctx_lock() for comments on the details
12024 * of swizzling perf_event::ctx.
12026 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
12027 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
12029 perf_remove_from_context(event
, 0);
12030 unaccount_event_cpu(event
, src_cpu
);
12032 list_add(&event
->migrate_entry
, &events
);
12036 * Wait for the events to quiesce before re-instating them.
12041 * Re-instate events in 2 passes.
12043 * Skip over group leaders and only install siblings on this first
12044 * pass, siblings will not get enabled without a leader, however a
12045 * leader will enable its siblings, even if those are still on the old
12048 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
12049 if (event
->group_leader
== event
)
12052 list_del(&event
->migrate_entry
);
12053 if (event
->state
>= PERF_EVENT_STATE_OFF
)
12054 event
->state
= PERF_EVENT_STATE_INACTIVE
;
12055 account_event_cpu(event
, dst_cpu
);
12056 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
12061 * Once all the siblings are setup properly, install the group leaders
12064 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
12065 list_del(&event
->migrate_entry
);
12066 if (event
->state
>= PERF_EVENT_STATE_OFF
)
12067 event
->state
= PERF_EVENT_STATE_INACTIVE
;
12068 account_event_cpu(event
, dst_cpu
);
12069 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
12072 mutex_unlock(&dst_ctx
->mutex
);
12073 mutex_unlock(&src_ctx
->mutex
);
12075 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
12077 static void sync_child_event(struct perf_event
*child_event
,
12078 struct task_struct
*child
)
12080 struct perf_event
*parent_event
= child_event
->parent
;
12083 if (child_event
->attr
.inherit_stat
)
12084 perf_event_read_event(child_event
, child
);
12086 child_val
= perf_event_count(child_event
);
12089 * Add back the child's count to the parent's count:
12091 atomic64_add(child_val
, &parent_event
->child_count
);
12092 atomic64_add(child_event
->total_time_enabled
,
12093 &parent_event
->child_total_time_enabled
);
12094 atomic64_add(child_event
->total_time_running
,
12095 &parent_event
->child_total_time_running
);
12099 perf_event_exit_event(struct perf_event
*child_event
,
12100 struct perf_event_context
*child_ctx
,
12101 struct task_struct
*child
)
12103 struct perf_event
*parent_event
= child_event
->parent
;
12106 * Do not destroy the 'original' grouping; because of the context
12107 * switch optimization the original events could've ended up in a
12108 * random child task.
12110 * If we were to destroy the original group, all group related
12111 * operations would cease to function properly after this random
12114 * Do destroy all inherited groups, we don't care about those
12115 * and being thorough is better.
12117 raw_spin_lock_irq(&child_ctx
->lock
);
12118 WARN_ON_ONCE(child_ctx
->is_active
);
12121 perf_group_detach(child_event
);
12122 list_del_event(child_event
, child_ctx
);
12123 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
12124 raw_spin_unlock_irq(&child_ctx
->lock
);
12127 * Parent events are governed by their filedesc, retain them.
12129 if (!parent_event
) {
12130 perf_event_wakeup(child_event
);
12134 * Child events can be cleaned up.
12137 sync_child_event(child_event
, child
);
12140 * Remove this event from the parent's list
12142 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
12143 mutex_lock(&parent_event
->child_mutex
);
12144 list_del_init(&child_event
->child_list
);
12145 mutex_unlock(&parent_event
->child_mutex
);
12148 * Kick perf_poll() for is_event_hup().
12150 perf_event_wakeup(parent_event
);
12151 free_event(child_event
);
12152 put_event(parent_event
);
12155 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
12157 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
12158 struct perf_event
*child_event
, *next
;
12160 WARN_ON_ONCE(child
!= current
);
12162 child_ctx
= perf_pin_task_context(child
, ctxn
);
12167 * In order to reduce the amount of tricky in ctx tear-down, we hold
12168 * ctx::mutex over the entire thing. This serializes against almost
12169 * everything that wants to access the ctx.
12171 * The exception is sys_perf_event_open() /
12172 * perf_event_create_kernel_count() which does find_get_context()
12173 * without ctx::mutex (it cannot because of the move_group double mutex
12174 * lock thing). See the comments in perf_install_in_context().
12176 mutex_lock(&child_ctx
->mutex
);
12179 * In a single ctx::lock section, de-schedule the events and detach the
12180 * context from the task such that we cannot ever get it scheduled back
12183 raw_spin_lock_irq(&child_ctx
->lock
);
12184 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
12187 * Now that the context is inactive, destroy the task <-> ctx relation
12188 * and mark the context dead.
12190 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
12191 put_ctx(child_ctx
); /* cannot be last */
12192 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
12193 put_task_struct(current
); /* cannot be last */
12195 clone_ctx
= unclone_ctx(child_ctx
);
12196 raw_spin_unlock_irq(&child_ctx
->lock
);
12199 put_ctx(clone_ctx
);
12202 * Report the task dead after unscheduling the events so that we
12203 * won't get any samples after PERF_RECORD_EXIT. We can however still
12204 * get a few PERF_RECORD_READ events.
12206 perf_event_task(child
, child_ctx
, 0);
12208 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
12209 perf_event_exit_event(child_event
, child_ctx
, child
);
12211 mutex_unlock(&child_ctx
->mutex
);
12213 put_ctx(child_ctx
);
12217 * When a child task exits, feed back event values to parent events.
12219 * Can be called with exec_update_mutex held when called from
12220 * install_exec_creds().
12222 void perf_event_exit_task(struct task_struct
*child
)
12224 struct perf_event
*event
, *tmp
;
12227 mutex_lock(&child
->perf_event_mutex
);
12228 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
12230 list_del_init(&event
->owner_entry
);
12233 * Ensure the list deletion is visible before we clear
12234 * the owner, closes a race against perf_release() where
12235 * we need to serialize on the owner->perf_event_mutex.
12237 smp_store_release(&event
->owner
, NULL
);
12239 mutex_unlock(&child
->perf_event_mutex
);
12241 for_each_task_context_nr(ctxn
)
12242 perf_event_exit_task_context(child
, ctxn
);
12245 * The perf_event_exit_task_context calls perf_event_task
12246 * with child's task_ctx, which generates EXIT events for
12247 * child contexts and sets child->perf_event_ctxp[] to NULL.
12248 * At this point we need to send EXIT events to cpu contexts.
12250 perf_event_task(child
, NULL
, 0);
12253 static void perf_free_event(struct perf_event
*event
,
12254 struct perf_event_context
*ctx
)
12256 struct perf_event
*parent
= event
->parent
;
12258 if (WARN_ON_ONCE(!parent
))
12261 mutex_lock(&parent
->child_mutex
);
12262 list_del_init(&event
->child_list
);
12263 mutex_unlock(&parent
->child_mutex
);
12267 raw_spin_lock_irq(&ctx
->lock
);
12268 perf_group_detach(event
);
12269 list_del_event(event
, ctx
);
12270 raw_spin_unlock_irq(&ctx
->lock
);
12275 * Free a context as created by inheritance by perf_event_init_task() below,
12276 * used by fork() in case of fail.
12278 * Even though the task has never lived, the context and events have been
12279 * exposed through the child_list, so we must take care tearing it all down.
12281 void perf_event_free_task(struct task_struct
*task
)
12283 struct perf_event_context
*ctx
;
12284 struct perf_event
*event
, *tmp
;
12287 for_each_task_context_nr(ctxn
) {
12288 ctx
= task
->perf_event_ctxp
[ctxn
];
12292 mutex_lock(&ctx
->mutex
);
12293 raw_spin_lock_irq(&ctx
->lock
);
12295 * Destroy the task <-> ctx relation and mark the context dead.
12297 * This is important because even though the task hasn't been
12298 * exposed yet the context has been (through child_list).
12300 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
12301 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
12302 put_task_struct(task
); /* cannot be last */
12303 raw_spin_unlock_irq(&ctx
->lock
);
12305 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
12306 perf_free_event(event
, ctx
);
12308 mutex_unlock(&ctx
->mutex
);
12311 * perf_event_release_kernel() could've stolen some of our
12312 * child events and still have them on its free_list. In that
12313 * case we must wait for these events to have been freed (in
12314 * particular all their references to this task must've been
12317 * Without this copy_process() will unconditionally free this
12318 * task (irrespective of its reference count) and
12319 * _free_event()'s put_task_struct(event->hw.target) will be a
12322 * Wait for all events to drop their context reference.
12324 wait_var_event(&ctx
->refcount
, refcount_read(&ctx
->refcount
) == 1);
12325 put_ctx(ctx
); /* must be last */
12329 void perf_event_delayed_put(struct task_struct
*task
)
12333 for_each_task_context_nr(ctxn
)
12334 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
12337 struct file
*perf_event_get(unsigned int fd
)
12339 struct file
*file
= fget(fd
);
12341 return ERR_PTR(-EBADF
);
12343 if (file
->f_op
!= &perf_fops
) {
12345 return ERR_PTR(-EBADF
);
12351 const struct perf_event
*perf_get_event(struct file
*file
)
12353 if (file
->f_op
!= &perf_fops
)
12354 return ERR_PTR(-EINVAL
);
12356 return file
->private_data
;
12359 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
12362 return ERR_PTR(-EINVAL
);
12364 return &event
->attr
;
12368 * Inherit an event from parent task to child task.
12371 * - valid pointer on success
12372 * - NULL for orphaned events
12373 * - IS_ERR() on error
12375 static struct perf_event
*
12376 inherit_event(struct perf_event
*parent_event
,
12377 struct task_struct
*parent
,
12378 struct perf_event_context
*parent_ctx
,
12379 struct task_struct
*child
,
12380 struct perf_event
*group_leader
,
12381 struct perf_event_context
*child_ctx
)
12383 enum perf_event_state parent_state
= parent_event
->state
;
12384 struct perf_event
*child_event
;
12385 unsigned long flags
;
12388 * Instead of creating recursive hierarchies of events,
12389 * we link inherited events back to the original parent,
12390 * which has a filp for sure, which we use as the reference
12393 if (parent_event
->parent
)
12394 parent_event
= parent_event
->parent
;
12396 child_event
= perf_event_alloc(&parent_event
->attr
,
12399 group_leader
, parent_event
,
12401 if (IS_ERR(child_event
))
12402 return child_event
;
12405 if ((child_event
->attach_state
& PERF_ATTACH_TASK_DATA
) &&
12406 !child_ctx
->task_ctx_data
) {
12407 struct pmu
*pmu
= child_event
->pmu
;
12409 child_ctx
->task_ctx_data
= kzalloc(pmu
->task_ctx_size
,
12411 if (!child_ctx
->task_ctx_data
) {
12412 free_event(child_event
);
12413 return ERR_PTR(-ENOMEM
);
12418 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
12419 * must be under the same lock in order to serialize against
12420 * perf_event_release_kernel(), such that either we must observe
12421 * is_orphaned_event() or they will observe us on the child_list.
12423 mutex_lock(&parent_event
->child_mutex
);
12424 if (is_orphaned_event(parent_event
) ||
12425 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
12426 mutex_unlock(&parent_event
->child_mutex
);
12427 /* task_ctx_data is freed with child_ctx */
12428 free_event(child_event
);
12432 get_ctx(child_ctx
);
12435 * Make the child state follow the state of the parent event,
12436 * not its attr.disabled bit. We hold the parent's mutex,
12437 * so we won't race with perf_event_{en, dis}able_family.
12439 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
12440 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
12442 child_event
->state
= PERF_EVENT_STATE_OFF
;
12444 if (parent_event
->attr
.freq
) {
12445 u64 sample_period
= parent_event
->hw
.sample_period
;
12446 struct hw_perf_event
*hwc
= &child_event
->hw
;
12448 hwc
->sample_period
= sample_period
;
12449 hwc
->last_period
= sample_period
;
12451 local64_set(&hwc
->period_left
, sample_period
);
12454 child_event
->ctx
= child_ctx
;
12455 child_event
->overflow_handler
= parent_event
->overflow_handler
;
12456 child_event
->overflow_handler_context
12457 = parent_event
->overflow_handler_context
;
12460 * Precalculate sample_data sizes
12462 perf_event__header_size(child_event
);
12463 perf_event__id_header_size(child_event
);
12466 * Link it up in the child's context:
12468 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
12469 add_event_to_ctx(child_event
, child_ctx
);
12470 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
12473 * Link this into the parent event's child list
12475 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
12476 mutex_unlock(&parent_event
->child_mutex
);
12478 return child_event
;
12482 * Inherits an event group.
12484 * This will quietly suppress orphaned events; !inherit_event() is not an error.
12485 * This matches with perf_event_release_kernel() removing all child events.
12491 static int inherit_group(struct perf_event
*parent_event
,
12492 struct task_struct
*parent
,
12493 struct perf_event_context
*parent_ctx
,
12494 struct task_struct
*child
,
12495 struct perf_event_context
*child_ctx
)
12497 struct perf_event
*leader
;
12498 struct perf_event
*sub
;
12499 struct perf_event
*child_ctr
;
12501 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
12502 child
, NULL
, child_ctx
);
12503 if (IS_ERR(leader
))
12504 return PTR_ERR(leader
);
12506 * @leader can be NULL here because of is_orphaned_event(). In this
12507 * case inherit_event() will create individual events, similar to what
12508 * perf_group_detach() would do anyway.
12510 for_each_sibling_event(sub
, parent_event
) {
12511 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
12512 child
, leader
, child_ctx
);
12513 if (IS_ERR(child_ctr
))
12514 return PTR_ERR(child_ctr
);
12516 if (sub
->aux_event
== parent_event
&& child_ctr
&&
12517 !perf_get_aux_event(child_ctr
, leader
))
12524 * Creates the child task context and tries to inherit the event-group.
12526 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
12527 * inherited_all set when we 'fail' to inherit an orphaned event; this is
12528 * consistent with perf_event_release_kernel() removing all child events.
12535 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
12536 struct perf_event_context
*parent_ctx
,
12537 struct task_struct
*child
, int ctxn
,
12538 int *inherited_all
)
12541 struct perf_event_context
*child_ctx
;
12543 if (!event
->attr
.inherit
) {
12544 *inherited_all
= 0;
12548 child_ctx
= child
->perf_event_ctxp
[ctxn
];
12551 * This is executed from the parent task context, so
12552 * inherit events that have been marked for cloning.
12553 * First allocate and initialize a context for the
12556 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
12560 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
12563 ret
= inherit_group(event
, parent
, parent_ctx
,
12567 *inherited_all
= 0;
12573 * Initialize the perf_event context in task_struct
12575 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
12577 struct perf_event_context
*child_ctx
, *parent_ctx
;
12578 struct perf_event_context
*cloned_ctx
;
12579 struct perf_event
*event
;
12580 struct task_struct
*parent
= current
;
12581 int inherited_all
= 1;
12582 unsigned long flags
;
12585 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
12589 * If the parent's context is a clone, pin it so it won't get
12590 * swapped under us.
12592 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
12597 * No need to check if parent_ctx != NULL here; since we saw
12598 * it non-NULL earlier, the only reason for it to become NULL
12599 * is if we exit, and since we're currently in the middle of
12600 * a fork we can't be exiting at the same time.
12604 * Lock the parent list. No need to lock the child - not PID
12605 * hashed yet and not running, so nobody can access it.
12607 mutex_lock(&parent_ctx
->mutex
);
12610 * We dont have to disable NMIs - we are only looking at
12611 * the list, not manipulating it:
12613 perf_event_groups_for_each(event
, &parent_ctx
->pinned_groups
) {
12614 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12615 child
, ctxn
, &inherited_all
);
12621 * We can't hold ctx->lock when iterating the ->flexible_group list due
12622 * to allocations, but we need to prevent rotation because
12623 * rotate_ctx() will change the list from interrupt context.
12625 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12626 parent_ctx
->rotate_disable
= 1;
12627 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12629 perf_event_groups_for_each(event
, &parent_ctx
->flexible_groups
) {
12630 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12631 child
, ctxn
, &inherited_all
);
12636 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12637 parent_ctx
->rotate_disable
= 0;
12639 child_ctx
= child
->perf_event_ctxp
[ctxn
];
12641 if (child_ctx
&& inherited_all
) {
12643 * Mark the child context as a clone of the parent
12644 * context, or of whatever the parent is a clone of.
12646 * Note that if the parent is a clone, the holding of
12647 * parent_ctx->lock avoids it from being uncloned.
12649 cloned_ctx
= parent_ctx
->parent_ctx
;
12651 child_ctx
->parent_ctx
= cloned_ctx
;
12652 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
12654 child_ctx
->parent_ctx
= parent_ctx
;
12655 child_ctx
->parent_gen
= parent_ctx
->generation
;
12657 get_ctx(child_ctx
->parent_ctx
);
12660 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12662 mutex_unlock(&parent_ctx
->mutex
);
12664 perf_unpin_context(parent_ctx
);
12665 put_ctx(parent_ctx
);
12671 * Initialize the perf_event context in task_struct
12673 int perf_event_init_task(struct task_struct
*child
)
12677 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
12678 mutex_init(&child
->perf_event_mutex
);
12679 INIT_LIST_HEAD(&child
->perf_event_list
);
12681 for_each_task_context_nr(ctxn
) {
12682 ret
= perf_event_init_context(child
, ctxn
);
12684 perf_event_free_task(child
);
12692 static void __init
perf_event_init_all_cpus(void)
12694 struct swevent_htable
*swhash
;
12697 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
12699 for_each_possible_cpu(cpu
) {
12700 swhash
= &per_cpu(swevent_htable
, cpu
);
12701 mutex_init(&swhash
->hlist_mutex
);
12702 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
12704 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
12705 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
12707 #ifdef CONFIG_CGROUP_PERF
12708 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
12710 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
12714 static void perf_swevent_init_cpu(unsigned int cpu
)
12716 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
12718 mutex_lock(&swhash
->hlist_mutex
);
12719 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
12720 struct swevent_hlist
*hlist
;
12722 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
12724 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
12726 mutex_unlock(&swhash
->hlist_mutex
);
12729 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
12730 static void __perf_event_exit_context(void *__info
)
12732 struct perf_event_context
*ctx
= __info
;
12733 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
12734 struct perf_event
*event
;
12736 raw_spin_lock(&ctx
->lock
);
12737 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
12738 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
12739 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
12740 raw_spin_unlock(&ctx
->lock
);
12743 static void perf_event_exit_cpu_context(int cpu
)
12745 struct perf_cpu_context
*cpuctx
;
12746 struct perf_event_context
*ctx
;
12749 mutex_lock(&pmus_lock
);
12750 list_for_each_entry(pmu
, &pmus
, entry
) {
12751 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12752 ctx
= &cpuctx
->ctx
;
12754 mutex_lock(&ctx
->mutex
);
12755 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
12756 cpuctx
->online
= 0;
12757 mutex_unlock(&ctx
->mutex
);
12759 cpumask_clear_cpu(cpu
, perf_online_mask
);
12760 mutex_unlock(&pmus_lock
);
12764 static void perf_event_exit_cpu_context(int cpu
) { }
12768 int perf_event_init_cpu(unsigned int cpu
)
12770 struct perf_cpu_context
*cpuctx
;
12771 struct perf_event_context
*ctx
;
12774 perf_swevent_init_cpu(cpu
);
12776 mutex_lock(&pmus_lock
);
12777 cpumask_set_cpu(cpu
, perf_online_mask
);
12778 list_for_each_entry(pmu
, &pmus
, entry
) {
12779 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12780 ctx
= &cpuctx
->ctx
;
12782 mutex_lock(&ctx
->mutex
);
12783 cpuctx
->online
= 1;
12784 mutex_unlock(&ctx
->mutex
);
12786 mutex_unlock(&pmus_lock
);
12791 int perf_event_exit_cpu(unsigned int cpu
)
12793 perf_event_exit_cpu_context(cpu
);
12798 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
12802 for_each_online_cpu(cpu
)
12803 perf_event_exit_cpu(cpu
);
12809 * Run the perf reboot notifier at the very last possible moment so that
12810 * the generic watchdog code runs as long as possible.
12812 static struct notifier_block perf_reboot_notifier
= {
12813 .notifier_call
= perf_reboot
,
12814 .priority
= INT_MIN
,
12817 void __init
perf_event_init(void)
12821 idr_init(&pmu_idr
);
12823 perf_event_init_all_cpus();
12824 init_srcu_struct(&pmus_srcu
);
12825 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
12826 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
12827 perf_pmu_register(&perf_task_clock
, NULL
, -1);
12828 perf_tp_register();
12829 perf_event_init_cpu(smp_processor_id());
12830 register_reboot_notifier(&perf_reboot_notifier
);
12832 ret
= init_hw_breakpoint();
12833 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
12836 * Build time assertion that we keep the data_head at the intended
12837 * location. IOW, validation we got the __reserved[] size right.
12839 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
12843 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
12846 struct perf_pmu_events_attr
*pmu_attr
=
12847 container_of(attr
, struct perf_pmu_events_attr
, attr
);
12849 if (pmu_attr
->event_str
)
12850 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
12854 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
12856 static int __init
perf_event_sysfs_init(void)
12861 mutex_lock(&pmus_lock
);
12863 ret
= bus_register(&pmu_bus
);
12867 list_for_each_entry(pmu
, &pmus
, entry
) {
12868 if (!pmu
->name
|| pmu
->type
< 0)
12871 ret
= pmu_dev_alloc(pmu
);
12872 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
12874 pmu_bus_running
= 1;
12878 mutex_unlock(&pmus_lock
);
12882 device_initcall(perf_event_sysfs_init
);
12884 #ifdef CONFIG_CGROUP_PERF
12885 static struct cgroup_subsys_state
*
12886 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
12888 struct perf_cgroup
*jc
;
12890 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
12892 return ERR_PTR(-ENOMEM
);
12894 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
12897 return ERR_PTR(-ENOMEM
);
12903 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
12905 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
12907 free_percpu(jc
->info
);
12911 static int perf_cgroup_css_online(struct cgroup_subsys_state
*css
)
12913 perf_event_cgroup(css
->cgroup
);
12917 static int __perf_cgroup_move(void *info
)
12919 struct task_struct
*task
= info
;
12921 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
12926 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
12928 struct task_struct
*task
;
12929 struct cgroup_subsys_state
*css
;
12931 cgroup_taskset_for_each(task
, css
, tset
)
12932 task_function_call(task
, __perf_cgroup_move
, task
);
12935 struct cgroup_subsys perf_event_cgrp_subsys
= {
12936 .css_alloc
= perf_cgroup_css_alloc
,
12937 .css_free
= perf_cgroup_css_free
,
12938 .css_online
= perf_cgroup_css_online
,
12939 .attach
= perf_cgroup_attach
,
12941 * Implicitly enable on dfl hierarchy so that perf events can
12942 * always be filtered by cgroup2 path as long as perf_event
12943 * controller is not mounted on a legacy hierarchy.
12945 .implicit_on_dfl
= true,
12948 #endif /* CONFIG_CGROUP_PERF */