2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 WARN_ON_ONCE(!irqs_disabled());
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 WARN_ON_ONCE(!irqs_disabled());
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
394 * perf event paranoia level:
395 * -1 - not paranoid at all
396 * 0 - disallow raw tracepoint access for unpriv
397 * 1 - disallow cpu events for unpriv
398 * 2 - disallow kernel profiling for unpriv
400 int sysctl_perf_event_paranoid __read_mostly
= 2;
402 /* Minimum for 512 kiB + 1 user control page */
403 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
406 * max perf event sample rate
408 #define DEFAULT_MAX_SAMPLE_RATE 100000
409 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
410 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
412 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
414 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
415 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
417 static int perf_sample_allowed_ns __read_mostly
=
418 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
420 static void update_perf_cpu_limits(void)
422 u64 tmp
= perf_sample_period_ns
;
424 tmp
*= sysctl_perf_cpu_time_max_percent
;
425 tmp
= div_u64(tmp
, 100);
429 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
432 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
434 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
435 void __user
*buffer
, size_t *lenp
,
438 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
444 * If throttling is disabled don't allow the write:
446 if (sysctl_perf_cpu_time_max_percent
== 100 ||
447 sysctl_perf_cpu_time_max_percent
== 0)
450 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
451 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
452 update_perf_cpu_limits();
457 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
459 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
460 void __user
*buffer
, size_t *lenp
,
463 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
468 if (sysctl_perf_cpu_time_max_percent
== 100 ||
469 sysctl_perf_cpu_time_max_percent
== 0) {
471 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
472 WRITE_ONCE(perf_sample_allowed_ns
, 0);
474 update_perf_cpu_limits();
481 * perf samples are done in some very critical code paths (NMIs).
482 * If they take too much CPU time, the system can lock up and not
483 * get any real work done. This will drop the sample rate when
484 * we detect that events are taking too long.
486 #define NR_ACCUMULATED_SAMPLES 128
487 static DEFINE_PER_CPU(u64
, running_sample_length
);
489 static u64 __report_avg
;
490 static u64 __report_allowed
;
492 static void perf_duration_warn(struct irq_work
*w
)
494 printk_ratelimited(KERN_INFO
495 "perf: interrupt took too long (%lld > %lld), lowering "
496 "kernel.perf_event_max_sample_rate to %d\n",
497 __report_avg
, __report_allowed
,
498 sysctl_perf_event_sample_rate
);
501 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
503 void perf_sample_event_took(u64 sample_len_ns
)
505 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
513 /* Decay the counter by 1 average sample. */
514 running_len
= __this_cpu_read(running_sample_length
);
515 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
516 running_len
+= sample_len_ns
;
517 __this_cpu_write(running_sample_length
, running_len
);
520 * Note: this will be biased artifically low until we have
521 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
522 * from having to maintain a count.
524 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
525 if (avg_len
<= max_len
)
528 __report_avg
= avg_len
;
529 __report_allowed
= max_len
;
532 * Compute a throttle threshold 25% below the current duration.
534 avg_len
+= avg_len
/ 4;
535 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
541 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
542 WRITE_ONCE(max_samples_per_tick
, max
);
544 sysctl_perf_event_sample_rate
= max
* HZ
;
545 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
547 if (!irq_work_queue(&perf_duration_work
)) {
548 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
549 "kernel.perf_event_max_sample_rate to %d\n",
550 __report_avg
, __report_allowed
,
551 sysctl_perf_event_sample_rate
);
555 static atomic64_t perf_event_id
;
557 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
558 enum event_type_t event_type
);
560 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
561 enum event_type_t event_type
,
562 struct task_struct
*task
);
564 static void update_context_time(struct perf_event_context
*ctx
);
565 static u64
perf_event_time(struct perf_event
*event
);
567 void __weak
perf_event_print_debug(void) { }
569 extern __weak
const char *perf_pmu_name(void)
574 static inline u64
perf_clock(void)
576 return local_clock();
579 static inline u64
perf_event_clock(struct perf_event
*event
)
581 return event
->clock();
584 #ifdef CONFIG_CGROUP_PERF
587 perf_cgroup_match(struct perf_event
*event
)
589 struct perf_event_context
*ctx
= event
->ctx
;
590 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
592 /* @event doesn't care about cgroup */
596 /* wants specific cgroup scope but @cpuctx isn't associated with any */
601 * Cgroup scoping is recursive. An event enabled for a cgroup is
602 * also enabled for all its descendant cgroups. If @cpuctx's
603 * cgroup is a descendant of @event's (the test covers identity
604 * case), it's a match.
606 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
607 event
->cgrp
->css
.cgroup
);
610 static inline void perf_detach_cgroup(struct perf_event
*event
)
612 css_put(&event
->cgrp
->css
);
616 static inline int is_cgroup_event(struct perf_event
*event
)
618 return event
->cgrp
!= NULL
;
621 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
623 struct perf_cgroup_info
*t
;
625 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
629 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
631 struct perf_cgroup_info
*info
;
636 info
= this_cpu_ptr(cgrp
->info
);
638 info
->time
+= now
- info
->timestamp
;
639 info
->timestamp
= now
;
642 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
644 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
646 __update_cgrp_time(cgrp_out
);
649 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
651 struct perf_cgroup
*cgrp
;
654 * ensure we access cgroup data only when needed and
655 * when we know the cgroup is pinned (css_get)
657 if (!is_cgroup_event(event
))
660 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
662 * Do not update time when cgroup is not active
664 if (cgrp
== event
->cgrp
)
665 __update_cgrp_time(event
->cgrp
);
669 perf_cgroup_set_timestamp(struct task_struct
*task
,
670 struct perf_event_context
*ctx
)
672 struct perf_cgroup
*cgrp
;
673 struct perf_cgroup_info
*info
;
676 * ctx->lock held by caller
677 * ensure we do not access cgroup data
678 * unless we have the cgroup pinned (css_get)
680 if (!task
|| !ctx
->nr_cgroups
)
683 cgrp
= perf_cgroup_from_task(task
, ctx
);
684 info
= this_cpu_ptr(cgrp
->info
);
685 info
->timestamp
= ctx
->timestamp
;
688 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
690 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
691 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
694 * reschedule events based on the cgroup constraint of task.
696 * mode SWOUT : schedule out everything
697 * mode SWIN : schedule in based on cgroup for next
699 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
701 struct perf_cpu_context
*cpuctx
;
702 struct list_head
*list
;
706 * Disable interrupts and preemption to avoid this CPU's
707 * cgrp_cpuctx_entry to change under us.
709 local_irq_save(flags
);
711 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
712 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
713 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
715 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
716 perf_pmu_disable(cpuctx
->ctx
.pmu
);
718 if (mode
& PERF_CGROUP_SWOUT
) {
719 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
721 * must not be done before ctxswout due
722 * to event_filter_match() in event_sched_out()
727 if (mode
& PERF_CGROUP_SWIN
) {
728 WARN_ON_ONCE(cpuctx
->cgrp
);
730 * set cgrp before ctxsw in to allow
731 * event_filter_match() to not have to pass
733 * we pass the cpuctx->ctx to perf_cgroup_from_task()
734 * because cgorup events are only per-cpu
736 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
738 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
740 perf_pmu_enable(cpuctx
->ctx
.pmu
);
741 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
744 local_irq_restore(flags
);
747 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
748 struct task_struct
*next
)
750 struct perf_cgroup
*cgrp1
;
751 struct perf_cgroup
*cgrp2
= NULL
;
755 * we come here when we know perf_cgroup_events > 0
756 * we do not need to pass the ctx here because we know
757 * we are holding the rcu lock
759 cgrp1
= perf_cgroup_from_task(task
, NULL
);
760 cgrp2
= perf_cgroup_from_task(next
, NULL
);
763 * only schedule out current cgroup events if we know
764 * that we are switching to a different cgroup. Otherwise,
765 * do no touch the cgroup events.
768 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
773 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
774 struct task_struct
*task
)
776 struct perf_cgroup
*cgrp1
;
777 struct perf_cgroup
*cgrp2
= NULL
;
781 * we come here when we know perf_cgroup_events > 0
782 * we do not need to pass the ctx here because we know
783 * we are holding the rcu lock
785 cgrp1
= perf_cgroup_from_task(task
, NULL
);
786 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
789 * only need to schedule in cgroup events if we are changing
790 * cgroup during ctxsw. Cgroup events were not scheduled
791 * out of ctxsw out if that was not the case.
794 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
799 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
800 struct perf_event_attr
*attr
,
801 struct perf_event
*group_leader
)
803 struct perf_cgroup
*cgrp
;
804 struct cgroup_subsys_state
*css
;
805 struct fd f
= fdget(fd
);
811 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
812 &perf_event_cgrp_subsys
);
818 cgrp
= container_of(css
, struct perf_cgroup
, css
);
822 * all events in a group must monitor
823 * the same cgroup because a task belongs
824 * to only one perf cgroup at a time
826 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
827 perf_detach_cgroup(event
);
836 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
838 struct perf_cgroup_info
*t
;
839 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
840 event
->shadow_ctx_time
= now
- t
->timestamp
;
844 perf_cgroup_defer_enabled(struct perf_event
*event
)
847 * when the current task's perf cgroup does not match
848 * the event's, we need to remember to call the
849 * perf_mark_enable() function the first time a task with
850 * a matching perf cgroup is scheduled in.
852 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
853 event
->cgrp_defer_enabled
= 1;
857 perf_cgroup_mark_enabled(struct perf_event
*event
,
858 struct perf_event_context
*ctx
)
860 struct perf_event
*sub
;
861 u64 tstamp
= perf_event_time(event
);
863 if (!event
->cgrp_defer_enabled
)
866 event
->cgrp_defer_enabled
= 0;
868 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
869 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
870 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
871 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
872 sub
->cgrp_defer_enabled
= 0;
878 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
879 * cleared when last cgroup event is removed.
882 list_update_cgroup_event(struct perf_event
*event
,
883 struct perf_event_context
*ctx
, bool add
)
885 struct perf_cpu_context
*cpuctx
;
886 struct list_head
*cpuctx_entry
;
888 if (!is_cgroup_event(event
))
891 if (add
&& ctx
->nr_cgroups
++)
893 else if (!add
&& --ctx
->nr_cgroups
)
896 * Because cgroup events are always per-cpu events,
897 * this will always be called from the right CPU.
899 cpuctx
= __get_cpu_context(ctx
);
900 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
901 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
903 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
904 if (perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
905 cpuctx
->cgrp
= event
->cgrp
;
907 list_del(cpuctx_entry
);
912 #else /* !CONFIG_CGROUP_PERF */
915 perf_cgroup_match(struct perf_event
*event
)
920 static inline void perf_detach_cgroup(struct perf_event
*event
)
923 static inline int is_cgroup_event(struct perf_event
*event
)
928 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
932 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
936 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
937 struct task_struct
*next
)
941 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
942 struct task_struct
*task
)
946 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
947 struct perf_event_attr
*attr
,
948 struct perf_event
*group_leader
)
954 perf_cgroup_set_timestamp(struct task_struct
*task
,
955 struct perf_event_context
*ctx
)
960 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
965 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
969 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
975 perf_cgroup_defer_enabled(struct perf_event
*event
)
980 perf_cgroup_mark_enabled(struct perf_event
*event
,
981 struct perf_event_context
*ctx
)
986 list_update_cgroup_event(struct perf_event
*event
,
987 struct perf_event_context
*ctx
, bool add
)
994 * set default to be dependent on timer tick just
997 #define PERF_CPU_HRTIMER (1000 / HZ)
999 * function must be called with interrupts disabled
1001 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1003 struct perf_cpu_context
*cpuctx
;
1006 WARN_ON(!irqs_disabled());
1008 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1009 rotations
= perf_rotate_context(cpuctx
);
1011 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1013 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1015 cpuctx
->hrtimer_active
= 0;
1016 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1018 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1021 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1023 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1024 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1027 /* no multiplexing needed for SW PMU */
1028 if (pmu
->task_ctx_nr
== perf_sw_context
)
1032 * check default is sane, if not set then force to
1033 * default interval (1/tick)
1035 interval
= pmu
->hrtimer_interval_ms
;
1037 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1039 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1041 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1042 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1043 timer
->function
= perf_mux_hrtimer_handler
;
1046 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1048 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1049 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1050 unsigned long flags
;
1052 /* not for SW PMU */
1053 if (pmu
->task_ctx_nr
== perf_sw_context
)
1056 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1057 if (!cpuctx
->hrtimer_active
) {
1058 cpuctx
->hrtimer_active
= 1;
1059 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1060 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1062 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1067 void perf_pmu_disable(struct pmu
*pmu
)
1069 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1071 pmu
->pmu_disable(pmu
);
1074 void perf_pmu_enable(struct pmu
*pmu
)
1076 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1078 pmu
->pmu_enable(pmu
);
1081 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1084 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1085 * perf_event_task_tick() are fully serialized because they're strictly cpu
1086 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1087 * disabled, while perf_event_task_tick is called from IRQ context.
1089 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1091 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1093 WARN_ON(!irqs_disabled());
1095 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1097 list_add(&ctx
->active_ctx_list
, head
);
1100 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1102 WARN_ON(!irqs_disabled());
1104 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1106 list_del_init(&ctx
->active_ctx_list
);
1109 static void get_ctx(struct perf_event_context
*ctx
)
1111 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1114 static void free_ctx(struct rcu_head
*head
)
1116 struct perf_event_context
*ctx
;
1118 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1119 kfree(ctx
->task_ctx_data
);
1123 static void put_ctx(struct perf_event_context
*ctx
)
1125 if (atomic_dec_and_test(&ctx
->refcount
)) {
1126 if (ctx
->parent_ctx
)
1127 put_ctx(ctx
->parent_ctx
);
1128 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1129 put_task_struct(ctx
->task
);
1130 call_rcu(&ctx
->rcu_head
, free_ctx
);
1135 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1136 * perf_pmu_migrate_context() we need some magic.
1138 * Those places that change perf_event::ctx will hold both
1139 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1141 * Lock ordering is by mutex address. There are two other sites where
1142 * perf_event_context::mutex nests and those are:
1144 * - perf_event_exit_task_context() [ child , 0 ]
1145 * perf_event_exit_event()
1146 * put_event() [ parent, 1 ]
1148 * - perf_event_init_context() [ parent, 0 ]
1149 * inherit_task_group()
1152 * perf_event_alloc()
1154 * perf_try_init_event() [ child , 1 ]
1156 * While it appears there is an obvious deadlock here -- the parent and child
1157 * nesting levels are inverted between the two. This is in fact safe because
1158 * life-time rules separate them. That is an exiting task cannot fork, and a
1159 * spawning task cannot (yet) exit.
1161 * But remember that that these are parent<->child context relations, and
1162 * migration does not affect children, therefore these two orderings should not
1165 * The change in perf_event::ctx does not affect children (as claimed above)
1166 * because the sys_perf_event_open() case will install a new event and break
1167 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1168 * concerned with cpuctx and that doesn't have children.
1170 * The places that change perf_event::ctx will issue:
1172 * perf_remove_from_context();
1173 * synchronize_rcu();
1174 * perf_install_in_context();
1176 * to affect the change. The remove_from_context() + synchronize_rcu() should
1177 * quiesce the event, after which we can install it in the new location. This
1178 * means that only external vectors (perf_fops, prctl) can perturb the event
1179 * while in transit. Therefore all such accessors should also acquire
1180 * perf_event_context::mutex to serialize against this.
1182 * However; because event->ctx can change while we're waiting to acquire
1183 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1188 * task_struct::perf_event_mutex
1189 * perf_event_context::mutex
1190 * perf_event::child_mutex;
1191 * perf_event_context::lock
1192 * perf_event::mmap_mutex
1195 static struct perf_event_context
*
1196 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1198 struct perf_event_context
*ctx
;
1202 ctx
= ACCESS_ONCE(event
->ctx
);
1203 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1209 mutex_lock_nested(&ctx
->mutex
, nesting
);
1210 if (event
->ctx
!= ctx
) {
1211 mutex_unlock(&ctx
->mutex
);
1219 static inline struct perf_event_context
*
1220 perf_event_ctx_lock(struct perf_event
*event
)
1222 return perf_event_ctx_lock_nested(event
, 0);
1225 static void perf_event_ctx_unlock(struct perf_event
*event
,
1226 struct perf_event_context
*ctx
)
1228 mutex_unlock(&ctx
->mutex
);
1233 * This must be done under the ctx->lock, such as to serialize against
1234 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1235 * calling scheduler related locks and ctx->lock nests inside those.
1237 static __must_check
struct perf_event_context
*
1238 unclone_ctx(struct perf_event_context
*ctx
)
1240 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1242 lockdep_assert_held(&ctx
->lock
);
1245 ctx
->parent_ctx
= NULL
;
1251 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1254 * only top level events have the pid namespace they were created in
1257 event
= event
->parent
;
1259 return task_tgid_nr_ns(p
, event
->ns
);
1262 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1265 * only top level events have the pid namespace they were created in
1268 event
= event
->parent
;
1270 return task_pid_nr_ns(p
, event
->ns
);
1274 * If we inherit events we want to return the parent event id
1277 static u64
primary_event_id(struct perf_event
*event
)
1282 id
= event
->parent
->id
;
1288 * Get the perf_event_context for a task and lock it.
1290 * This has to cope with with the fact that until it is locked,
1291 * the context could get moved to another task.
1293 static struct perf_event_context
*
1294 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1296 struct perf_event_context
*ctx
;
1300 * One of the few rules of preemptible RCU is that one cannot do
1301 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1302 * part of the read side critical section was irqs-enabled -- see
1303 * rcu_read_unlock_special().
1305 * Since ctx->lock nests under rq->lock we must ensure the entire read
1306 * side critical section has interrupts disabled.
1308 local_irq_save(*flags
);
1310 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1313 * If this context is a clone of another, it might
1314 * get swapped for another underneath us by
1315 * perf_event_task_sched_out, though the
1316 * rcu_read_lock() protects us from any context
1317 * getting freed. Lock the context and check if it
1318 * got swapped before we could get the lock, and retry
1319 * if so. If we locked the right context, then it
1320 * can't get swapped on us any more.
1322 raw_spin_lock(&ctx
->lock
);
1323 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1324 raw_spin_unlock(&ctx
->lock
);
1326 local_irq_restore(*flags
);
1330 if (ctx
->task
== TASK_TOMBSTONE
||
1331 !atomic_inc_not_zero(&ctx
->refcount
)) {
1332 raw_spin_unlock(&ctx
->lock
);
1335 WARN_ON_ONCE(ctx
->task
!= task
);
1340 local_irq_restore(*flags
);
1345 * Get the context for a task and increment its pin_count so it
1346 * can't get swapped to another task. This also increments its
1347 * reference count so that the context can't get freed.
1349 static struct perf_event_context
*
1350 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1352 struct perf_event_context
*ctx
;
1353 unsigned long flags
;
1355 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1358 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1363 static void perf_unpin_context(struct perf_event_context
*ctx
)
1365 unsigned long flags
;
1367 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1369 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1373 * Update the record of the current time in a context.
1375 static void update_context_time(struct perf_event_context
*ctx
)
1377 u64 now
= perf_clock();
1379 ctx
->time
+= now
- ctx
->timestamp
;
1380 ctx
->timestamp
= now
;
1383 static u64
perf_event_time(struct perf_event
*event
)
1385 struct perf_event_context
*ctx
= event
->ctx
;
1387 if (is_cgroup_event(event
))
1388 return perf_cgroup_event_time(event
);
1390 return ctx
? ctx
->time
: 0;
1394 * Update the total_time_enabled and total_time_running fields for a event.
1396 static void update_event_times(struct perf_event
*event
)
1398 struct perf_event_context
*ctx
= event
->ctx
;
1401 lockdep_assert_held(&ctx
->lock
);
1403 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1404 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1408 * in cgroup mode, time_enabled represents
1409 * the time the event was enabled AND active
1410 * tasks were in the monitored cgroup. This is
1411 * independent of the activity of the context as
1412 * there may be a mix of cgroup and non-cgroup events.
1414 * That is why we treat cgroup events differently
1417 if (is_cgroup_event(event
))
1418 run_end
= perf_cgroup_event_time(event
);
1419 else if (ctx
->is_active
)
1420 run_end
= ctx
->time
;
1422 run_end
= event
->tstamp_stopped
;
1424 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1426 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1427 run_end
= event
->tstamp_stopped
;
1429 run_end
= perf_event_time(event
);
1431 event
->total_time_running
= run_end
- event
->tstamp_running
;
1436 * Update total_time_enabled and total_time_running for all events in a group.
1438 static void update_group_times(struct perf_event
*leader
)
1440 struct perf_event
*event
;
1442 update_event_times(leader
);
1443 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1444 update_event_times(event
);
1447 static enum event_type_t
get_event_type(struct perf_event
*event
)
1449 struct perf_event_context
*ctx
= event
->ctx
;
1450 enum event_type_t event_type
;
1452 lockdep_assert_held(&ctx
->lock
);
1454 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1456 event_type
|= EVENT_CPU
;
1461 static struct list_head
*
1462 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1464 if (event
->attr
.pinned
)
1465 return &ctx
->pinned_groups
;
1467 return &ctx
->flexible_groups
;
1471 * Add a event from the lists for its context.
1472 * Must be called with ctx->mutex and ctx->lock held.
1475 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1477 lockdep_assert_held(&ctx
->lock
);
1479 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1480 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1483 * If we're a stand alone event or group leader, we go to the context
1484 * list, group events are kept attached to the group so that
1485 * perf_group_detach can, at all times, locate all siblings.
1487 if (event
->group_leader
== event
) {
1488 struct list_head
*list
;
1490 event
->group_caps
= event
->event_caps
;
1492 list
= ctx_group_list(event
, ctx
);
1493 list_add_tail(&event
->group_entry
, list
);
1496 list_update_cgroup_event(event
, ctx
, true);
1498 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1500 if (event
->attr
.inherit_stat
)
1507 * Initialize event state based on the perf_event_attr::disabled.
1509 static inline void perf_event__state_init(struct perf_event
*event
)
1511 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1512 PERF_EVENT_STATE_INACTIVE
;
1515 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1517 int entry
= sizeof(u64
); /* value */
1521 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1522 size
+= sizeof(u64
);
1524 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1525 size
+= sizeof(u64
);
1527 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1528 entry
+= sizeof(u64
);
1530 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1532 size
+= sizeof(u64
);
1536 event
->read_size
= size
;
1539 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1541 struct perf_sample_data
*data
;
1544 if (sample_type
& PERF_SAMPLE_IP
)
1545 size
+= sizeof(data
->ip
);
1547 if (sample_type
& PERF_SAMPLE_ADDR
)
1548 size
+= sizeof(data
->addr
);
1550 if (sample_type
& PERF_SAMPLE_PERIOD
)
1551 size
+= sizeof(data
->period
);
1553 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1554 size
+= sizeof(data
->weight
);
1556 if (sample_type
& PERF_SAMPLE_READ
)
1557 size
+= event
->read_size
;
1559 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1560 size
+= sizeof(data
->data_src
.val
);
1562 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1563 size
+= sizeof(data
->txn
);
1565 event
->header_size
= size
;
1569 * Called at perf_event creation and when events are attached/detached from a
1572 static void perf_event__header_size(struct perf_event
*event
)
1574 __perf_event_read_size(event
,
1575 event
->group_leader
->nr_siblings
);
1576 __perf_event_header_size(event
, event
->attr
.sample_type
);
1579 static void perf_event__id_header_size(struct perf_event
*event
)
1581 struct perf_sample_data
*data
;
1582 u64 sample_type
= event
->attr
.sample_type
;
1585 if (sample_type
& PERF_SAMPLE_TID
)
1586 size
+= sizeof(data
->tid_entry
);
1588 if (sample_type
& PERF_SAMPLE_TIME
)
1589 size
+= sizeof(data
->time
);
1591 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1592 size
+= sizeof(data
->id
);
1594 if (sample_type
& PERF_SAMPLE_ID
)
1595 size
+= sizeof(data
->id
);
1597 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1598 size
+= sizeof(data
->stream_id
);
1600 if (sample_type
& PERF_SAMPLE_CPU
)
1601 size
+= sizeof(data
->cpu_entry
);
1603 event
->id_header_size
= size
;
1606 static bool perf_event_validate_size(struct perf_event
*event
)
1609 * The values computed here will be over-written when we actually
1612 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1613 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1614 perf_event__id_header_size(event
);
1617 * Sum the lot; should not exceed the 64k limit we have on records.
1618 * Conservative limit to allow for callchains and other variable fields.
1620 if (event
->read_size
+ event
->header_size
+
1621 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1627 static void perf_group_attach(struct perf_event
*event
)
1629 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1631 lockdep_assert_held(&event
->ctx
->lock
);
1634 * We can have double attach due to group movement in perf_event_open.
1636 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1639 event
->attach_state
|= PERF_ATTACH_GROUP
;
1641 if (group_leader
== event
)
1644 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1646 group_leader
->group_caps
&= event
->event_caps
;
1648 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1649 group_leader
->nr_siblings
++;
1651 perf_event__header_size(group_leader
);
1653 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1654 perf_event__header_size(pos
);
1658 * Remove a event from the lists for its context.
1659 * Must be called with ctx->mutex and ctx->lock held.
1662 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1664 WARN_ON_ONCE(event
->ctx
!= ctx
);
1665 lockdep_assert_held(&ctx
->lock
);
1668 * We can have double detach due to exit/hot-unplug + close.
1670 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1673 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1675 list_update_cgroup_event(event
, ctx
, false);
1678 if (event
->attr
.inherit_stat
)
1681 list_del_rcu(&event
->event_entry
);
1683 if (event
->group_leader
== event
)
1684 list_del_init(&event
->group_entry
);
1686 update_group_times(event
);
1689 * If event was in error state, then keep it
1690 * that way, otherwise bogus counts will be
1691 * returned on read(). The only way to get out
1692 * of error state is by explicit re-enabling
1695 if (event
->state
> PERF_EVENT_STATE_OFF
)
1696 event
->state
= PERF_EVENT_STATE_OFF
;
1701 static void perf_group_detach(struct perf_event
*event
)
1703 struct perf_event
*sibling
, *tmp
;
1704 struct list_head
*list
= NULL
;
1706 lockdep_assert_held(&event
->ctx
->lock
);
1709 * We can have double detach due to exit/hot-unplug + close.
1711 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1714 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1717 * If this is a sibling, remove it from its group.
1719 if (event
->group_leader
!= event
) {
1720 list_del_init(&event
->group_entry
);
1721 event
->group_leader
->nr_siblings
--;
1725 if (!list_empty(&event
->group_entry
))
1726 list
= &event
->group_entry
;
1729 * If this was a group event with sibling events then
1730 * upgrade the siblings to singleton events by adding them
1731 * to whatever list we are on.
1733 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1735 list_move_tail(&sibling
->group_entry
, list
);
1736 sibling
->group_leader
= sibling
;
1738 /* Inherit group flags from the previous leader */
1739 sibling
->group_caps
= event
->group_caps
;
1741 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1745 perf_event__header_size(event
->group_leader
);
1747 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1748 perf_event__header_size(tmp
);
1751 static bool is_orphaned_event(struct perf_event
*event
)
1753 return event
->state
== PERF_EVENT_STATE_DEAD
;
1756 static inline int __pmu_filter_match(struct perf_event
*event
)
1758 struct pmu
*pmu
= event
->pmu
;
1759 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1763 * Check whether we should attempt to schedule an event group based on
1764 * PMU-specific filtering. An event group can consist of HW and SW events,
1765 * potentially with a SW leader, so we must check all the filters, to
1766 * determine whether a group is schedulable:
1768 static inline int pmu_filter_match(struct perf_event
*event
)
1770 struct perf_event
*child
;
1772 if (!__pmu_filter_match(event
))
1775 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1776 if (!__pmu_filter_match(child
))
1784 event_filter_match(struct perf_event
*event
)
1786 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1787 perf_cgroup_match(event
) && pmu_filter_match(event
);
1791 event_sched_out(struct perf_event
*event
,
1792 struct perf_cpu_context
*cpuctx
,
1793 struct perf_event_context
*ctx
)
1795 u64 tstamp
= perf_event_time(event
);
1798 WARN_ON_ONCE(event
->ctx
!= ctx
);
1799 lockdep_assert_held(&ctx
->lock
);
1802 * An event which could not be activated because of
1803 * filter mismatch still needs to have its timings
1804 * maintained, otherwise bogus information is return
1805 * via read() for time_enabled, time_running:
1807 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1808 !event_filter_match(event
)) {
1809 delta
= tstamp
- event
->tstamp_stopped
;
1810 event
->tstamp_running
+= delta
;
1811 event
->tstamp_stopped
= tstamp
;
1814 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1817 perf_pmu_disable(event
->pmu
);
1819 event
->tstamp_stopped
= tstamp
;
1820 event
->pmu
->del(event
, 0);
1822 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1823 if (event
->pending_disable
) {
1824 event
->pending_disable
= 0;
1825 event
->state
= PERF_EVENT_STATE_OFF
;
1828 if (!is_software_event(event
))
1829 cpuctx
->active_oncpu
--;
1830 if (!--ctx
->nr_active
)
1831 perf_event_ctx_deactivate(ctx
);
1832 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1834 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1835 cpuctx
->exclusive
= 0;
1837 perf_pmu_enable(event
->pmu
);
1841 group_sched_out(struct perf_event
*group_event
,
1842 struct perf_cpu_context
*cpuctx
,
1843 struct perf_event_context
*ctx
)
1845 struct perf_event
*event
;
1846 int state
= group_event
->state
;
1848 perf_pmu_disable(ctx
->pmu
);
1850 event_sched_out(group_event
, cpuctx
, ctx
);
1853 * Schedule out siblings (if any):
1855 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1856 event_sched_out(event
, cpuctx
, ctx
);
1858 perf_pmu_enable(ctx
->pmu
);
1860 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1861 cpuctx
->exclusive
= 0;
1864 #define DETACH_GROUP 0x01UL
1867 * Cross CPU call to remove a performance event
1869 * We disable the event on the hardware level first. After that we
1870 * remove it from the context list.
1873 __perf_remove_from_context(struct perf_event
*event
,
1874 struct perf_cpu_context
*cpuctx
,
1875 struct perf_event_context
*ctx
,
1878 unsigned long flags
= (unsigned long)info
;
1880 event_sched_out(event
, cpuctx
, ctx
);
1881 if (flags
& DETACH_GROUP
)
1882 perf_group_detach(event
);
1883 list_del_event(event
, ctx
);
1885 if (!ctx
->nr_events
&& ctx
->is_active
) {
1888 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1889 cpuctx
->task_ctx
= NULL
;
1895 * Remove the event from a task's (or a CPU's) list of events.
1897 * If event->ctx is a cloned context, callers must make sure that
1898 * every task struct that event->ctx->task could possibly point to
1899 * remains valid. This is OK when called from perf_release since
1900 * that only calls us on the top-level context, which can't be a clone.
1901 * When called from perf_event_exit_task, it's OK because the
1902 * context has been detached from its task.
1904 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1906 struct perf_event_context
*ctx
= event
->ctx
;
1908 lockdep_assert_held(&ctx
->mutex
);
1910 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1913 * The above event_function_call() can NO-OP when it hits
1914 * TASK_TOMBSTONE. In that case we must already have been detached
1915 * from the context (by perf_event_exit_event()) but the grouping
1916 * might still be in-tact.
1918 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1919 if ((flags
& DETACH_GROUP
) &&
1920 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1922 * Since in that case we cannot possibly be scheduled, simply
1925 raw_spin_lock_irq(&ctx
->lock
);
1926 perf_group_detach(event
);
1927 raw_spin_unlock_irq(&ctx
->lock
);
1932 * Cross CPU call to disable a performance event
1934 static void __perf_event_disable(struct perf_event
*event
,
1935 struct perf_cpu_context
*cpuctx
,
1936 struct perf_event_context
*ctx
,
1939 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1942 update_context_time(ctx
);
1943 update_cgrp_time_from_event(event
);
1944 update_group_times(event
);
1945 if (event
== event
->group_leader
)
1946 group_sched_out(event
, cpuctx
, ctx
);
1948 event_sched_out(event
, cpuctx
, ctx
);
1949 event
->state
= PERF_EVENT_STATE_OFF
;
1955 * If event->ctx is a cloned context, callers must make sure that
1956 * every task struct that event->ctx->task could possibly point to
1957 * remains valid. This condition is satisifed when called through
1958 * perf_event_for_each_child or perf_event_for_each because they
1959 * hold the top-level event's child_mutex, so any descendant that
1960 * goes to exit will block in perf_event_exit_event().
1962 * When called from perf_pending_event it's OK because event->ctx
1963 * is the current context on this CPU and preemption is disabled,
1964 * hence we can't get into perf_event_task_sched_out for this context.
1966 static void _perf_event_disable(struct perf_event
*event
)
1968 struct perf_event_context
*ctx
= event
->ctx
;
1970 raw_spin_lock_irq(&ctx
->lock
);
1971 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1972 raw_spin_unlock_irq(&ctx
->lock
);
1975 raw_spin_unlock_irq(&ctx
->lock
);
1977 event_function_call(event
, __perf_event_disable
, NULL
);
1980 void perf_event_disable_local(struct perf_event
*event
)
1982 event_function_local(event
, __perf_event_disable
, NULL
);
1986 * Strictly speaking kernel users cannot create groups and therefore this
1987 * interface does not need the perf_event_ctx_lock() magic.
1989 void perf_event_disable(struct perf_event
*event
)
1991 struct perf_event_context
*ctx
;
1993 ctx
= perf_event_ctx_lock(event
);
1994 _perf_event_disable(event
);
1995 perf_event_ctx_unlock(event
, ctx
);
1997 EXPORT_SYMBOL_GPL(perf_event_disable
);
1999 void perf_event_disable_inatomic(struct perf_event
*event
)
2001 event
->pending_disable
= 1;
2002 irq_work_queue(&event
->pending
);
2005 static void perf_set_shadow_time(struct perf_event
*event
,
2006 struct perf_event_context
*ctx
,
2010 * use the correct time source for the time snapshot
2012 * We could get by without this by leveraging the
2013 * fact that to get to this function, the caller
2014 * has most likely already called update_context_time()
2015 * and update_cgrp_time_xx() and thus both timestamp
2016 * are identical (or very close). Given that tstamp is,
2017 * already adjusted for cgroup, we could say that:
2018 * tstamp - ctx->timestamp
2020 * tstamp - cgrp->timestamp.
2022 * Then, in perf_output_read(), the calculation would
2023 * work with no changes because:
2024 * - event is guaranteed scheduled in
2025 * - no scheduled out in between
2026 * - thus the timestamp would be the same
2028 * But this is a bit hairy.
2030 * So instead, we have an explicit cgroup call to remain
2031 * within the time time source all along. We believe it
2032 * is cleaner and simpler to understand.
2034 if (is_cgroup_event(event
))
2035 perf_cgroup_set_shadow_time(event
, tstamp
);
2037 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2040 #define MAX_INTERRUPTS (~0ULL)
2042 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2043 static void perf_log_itrace_start(struct perf_event
*event
);
2046 event_sched_in(struct perf_event
*event
,
2047 struct perf_cpu_context
*cpuctx
,
2048 struct perf_event_context
*ctx
)
2050 u64 tstamp
= perf_event_time(event
);
2053 lockdep_assert_held(&ctx
->lock
);
2055 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2058 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2060 * Order event::oncpu write to happen before the ACTIVE state
2064 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2067 * Unthrottle events, since we scheduled we might have missed several
2068 * ticks already, also for a heavily scheduling task there is little
2069 * guarantee it'll get a tick in a timely manner.
2071 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2072 perf_log_throttle(event
, 1);
2073 event
->hw
.interrupts
= 0;
2077 * The new state must be visible before we turn it on in the hardware:
2081 perf_pmu_disable(event
->pmu
);
2083 perf_set_shadow_time(event
, ctx
, tstamp
);
2085 perf_log_itrace_start(event
);
2087 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2088 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2094 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2096 if (!is_software_event(event
))
2097 cpuctx
->active_oncpu
++;
2098 if (!ctx
->nr_active
++)
2099 perf_event_ctx_activate(ctx
);
2100 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2103 if (event
->attr
.exclusive
)
2104 cpuctx
->exclusive
= 1;
2107 perf_pmu_enable(event
->pmu
);
2113 group_sched_in(struct perf_event
*group_event
,
2114 struct perf_cpu_context
*cpuctx
,
2115 struct perf_event_context
*ctx
)
2117 struct perf_event
*event
, *partial_group
= NULL
;
2118 struct pmu
*pmu
= ctx
->pmu
;
2119 u64 now
= ctx
->time
;
2120 bool simulate
= false;
2122 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2125 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2127 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2128 pmu
->cancel_txn(pmu
);
2129 perf_mux_hrtimer_restart(cpuctx
);
2134 * Schedule in siblings as one group (if any):
2136 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2137 if (event_sched_in(event
, cpuctx
, ctx
)) {
2138 partial_group
= event
;
2143 if (!pmu
->commit_txn(pmu
))
2148 * Groups can be scheduled in as one unit only, so undo any
2149 * partial group before returning:
2150 * The events up to the failed event are scheduled out normally,
2151 * tstamp_stopped will be updated.
2153 * The failed events and the remaining siblings need to have
2154 * their timings updated as if they had gone thru event_sched_in()
2155 * and event_sched_out(). This is required to get consistent timings
2156 * across the group. This also takes care of the case where the group
2157 * could never be scheduled by ensuring tstamp_stopped is set to mark
2158 * the time the event was actually stopped, such that time delta
2159 * calculation in update_event_times() is correct.
2161 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2162 if (event
== partial_group
)
2166 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2167 event
->tstamp_stopped
= now
;
2169 event_sched_out(event
, cpuctx
, ctx
);
2172 event_sched_out(group_event
, cpuctx
, ctx
);
2174 pmu
->cancel_txn(pmu
);
2176 perf_mux_hrtimer_restart(cpuctx
);
2182 * Work out whether we can put this event group on the CPU now.
2184 static int group_can_go_on(struct perf_event
*event
,
2185 struct perf_cpu_context
*cpuctx
,
2189 * Groups consisting entirely of software events can always go on.
2191 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2194 * If an exclusive group is already on, no other hardware
2197 if (cpuctx
->exclusive
)
2200 * If this group is exclusive and there are already
2201 * events on the CPU, it can't go on.
2203 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2206 * Otherwise, try to add it if all previous groups were able
2212 static void add_event_to_ctx(struct perf_event
*event
,
2213 struct perf_event_context
*ctx
)
2215 u64 tstamp
= perf_event_time(event
);
2217 list_add_event(event
, ctx
);
2218 perf_group_attach(event
);
2219 event
->tstamp_enabled
= tstamp
;
2220 event
->tstamp_running
= tstamp
;
2221 event
->tstamp_stopped
= tstamp
;
2224 static void ctx_sched_out(struct perf_event_context
*ctx
,
2225 struct perf_cpu_context
*cpuctx
,
2226 enum event_type_t event_type
);
2228 ctx_sched_in(struct perf_event_context
*ctx
,
2229 struct perf_cpu_context
*cpuctx
,
2230 enum event_type_t event_type
,
2231 struct task_struct
*task
);
2233 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2234 struct perf_event_context
*ctx
,
2235 enum event_type_t event_type
)
2237 if (!cpuctx
->task_ctx
)
2240 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2243 ctx_sched_out(ctx
, cpuctx
, event_type
);
2246 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2247 struct perf_event_context
*ctx
,
2248 struct task_struct
*task
)
2250 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2252 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2253 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2255 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2259 * We want to maintain the following priority of scheduling:
2260 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2261 * - task pinned (EVENT_PINNED)
2262 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2263 * - task flexible (EVENT_FLEXIBLE).
2265 * In order to avoid unscheduling and scheduling back in everything every
2266 * time an event is added, only do it for the groups of equal priority and
2269 * This can be called after a batch operation on task events, in which case
2270 * event_type is a bit mask of the types of events involved. For CPU events,
2271 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2273 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2274 struct perf_event_context
*task_ctx
,
2275 enum event_type_t event_type
)
2277 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2278 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2281 * If pinned groups are involved, flexible groups also need to be
2284 if (event_type
& EVENT_PINNED
)
2285 event_type
|= EVENT_FLEXIBLE
;
2287 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2289 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2292 * Decide which cpu ctx groups to schedule out based on the types
2293 * of events that caused rescheduling:
2294 * - EVENT_CPU: schedule out corresponding groups;
2295 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2296 * - otherwise, do nothing more.
2299 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2300 else if (ctx_event_type
& EVENT_PINNED
)
2301 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2303 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2304 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2308 * Cross CPU call to install and enable a performance event
2310 * Very similar to remote_function() + event_function() but cannot assume that
2311 * things like ctx->is_active and cpuctx->task_ctx are set.
2313 static int __perf_install_in_context(void *info
)
2315 struct perf_event
*event
= info
;
2316 struct perf_event_context
*ctx
= event
->ctx
;
2317 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2318 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2319 bool reprogram
= true;
2322 raw_spin_lock(&cpuctx
->ctx
.lock
);
2324 raw_spin_lock(&ctx
->lock
);
2327 reprogram
= (ctx
->task
== current
);
2330 * If the task is running, it must be running on this CPU,
2331 * otherwise we cannot reprogram things.
2333 * If its not running, we don't care, ctx->lock will
2334 * serialize against it becoming runnable.
2336 if (task_curr(ctx
->task
) && !reprogram
) {
2341 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2342 } else if (task_ctx
) {
2343 raw_spin_lock(&task_ctx
->lock
);
2347 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2348 add_event_to_ctx(event
, ctx
);
2349 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2351 add_event_to_ctx(event
, ctx
);
2355 perf_ctx_unlock(cpuctx
, task_ctx
);
2361 * Attach a performance event to a context.
2363 * Very similar to event_function_call, see comment there.
2366 perf_install_in_context(struct perf_event_context
*ctx
,
2367 struct perf_event
*event
,
2370 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2372 lockdep_assert_held(&ctx
->mutex
);
2374 if (event
->cpu
!= -1)
2378 * Ensures that if we can observe event->ctx, both the event and ctx
2379 * will be 'complete'. See perf_iterate_sb_cpu().
2381 smp_store_release(&event
->ctx
, ctx
);
2384 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2389 * Should not happen, we validate the ctx is still alive before calling.
2391 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2395 * Installing events is tricky because we cannot rely on ctx->is_active
2396 * to be set in case this is the nr_events 0 -> 1 transition.
2398 * Instead we use task_curr(), which tells us if the task is running.
2399 * However, since we use task_curr() outside of rq::lock, we can race
2400 * against the actual state. This means the result can be wrong.
2402 * If we get a false positive, we retry, this is harmless.
2404 * If we get a false negative, things are complicated. If we are after
2405 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2406 * value must be correct. If we're before, it doesn't matter since
2407 * perf_event_context_sched_in() will program the counter.
2409 * However, this hinges on the remote context switch having observed
2410 * our task->perf_event_ctxp[] store, such that it will in fact take
2411 * ctx::lock in perf_event_context_sched_in().
2413 * We do this by task_function_call(), if the IPI fails to hit the task
2414 * we know any future context switch of task must see the
2415 * perf_event_ctpx[] store.
2419 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2420 * task_cpu() load, such that if the IPI then does not find the task
2421 * running, a future context switch of that task must observe the
2426 if (!task_function_call(task
, __perf_install_in_context
, event
))
2429 raw_spin_lock_irq(&ctx
->lock
);
2431 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2433 * Cannot happen because we already checked above (which also
2434 * cannot happen), and we hold ctx->mutex, which serializes us
2435 * against perf_event_exit_task_context().
2437 raw_spin_unlock_irq(&ctx
->lock
);
2441 * If the task is not running, ctx->lock will avoid it becoming so,
2442 * thus we can safely install the event.
2444 if (task_curr(task
)) {
2445 raw_spin_unlock_irq(&ctx
->lock
);
2448 add_event_to_ctx(event
, ctx
);
2449 raw_spin_unlock_irq(&ctx
->lock
);
2453 * Put a event into inactive state and update time fields.
2454 * Enabling the leader of a group effectively enables all
2455 * the group members that aren't explicitly disabled, so we
2456 * have to update their ->tstamp_enabled also.
2457 * Note: this works for group members as well as group leaders
2458 * since the non-leader members' sibling_lists will be empty.
2460 static void __perf_event_mark_enabled(struct perf_event
*event
)
2462 struct perf_event
*sub
;
2463 u64 tstamp
= perf_event_time(event
);
2465 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2466 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2467 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2468 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2469 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2474 * Cross CPU call to enable a performance event
2476 static void __perf_event_enable(struct perf_event
*event
,
2477 struct perf_cpu_context
*cpuctx
,
2478 struct perf_event_context
*ctx
,
2481 struct perf_event
*leader
= event
->group_leader
;
2482 struct perf_event_context
*task_ctx
;
2484 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2485 event
->state
<= PERF_EVENT_STATE_ERROR
)
2489 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2491 __perf_event_mark_enabled(event
);
2493 if (!ctx
->is_active
)
2496 if (!event_filter_match(event
)) {
2497 if (is_cgroup_event(event
))
2498 perf_cgroup_defer_enabled(event
);
2499 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2504 * If the event is in a group and isn't the group leader,
2505 * then don't put it on unless the group is on.
2507 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2508 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2512 task_ctx
= cpuctx
->task_ctx
;
2514 WARN_ON_ONCE(task_ctx
!= ctx
);
2516 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2522 * If event->ctx is a cloned context, callers must make sure that
2523 * every task struct that event->ctx->task could possibly point to
2524 * remains valid. This condition is satisfied when called through
2525 * perf_event_for_each_child or perf_event_for_each as described
2526 * for perf_event_disable.
2528 static void _perf_event_enable(struct perf_event
*event
)
2530 struct perf_event_context
*ctx
= event
->ctx
;
2532 raw_spin_lock_irq(&ctx
->lock
);
2533 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2534 event
->state
< PERF_EVENT_STATE_ERROR
) {
2535 raw_spin_unlock_irq(&ctx
->lock
);
2540 * If the event is in error state, clear that first.
2542 * That way, if we see the event in error state below, we know that it
2543 * has gone back into error state, as distinct from the task having
2544 * been scheduled away before the cross-call arrived.
2546 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2547 event
->state
= PERF_EVENT_STATE_OFF
;
2548 raw_spin_unlock_irq(&ctx
->lock
);
2550 event_function_call(event
, __perf_event_enable
, NULL
);
2554 * See perf_event_disable();
2556 void perf_event_enable(struct perf_event
*event
)
2558 struct perf_event_context
*ctx
;
2560 ctx
= perf_event_ctx_lock(event
);
2561 _perf_event_enable(event
);
2562 perf_event_ctx_unlock(event
, ctx
);
2564 EXPORT_SYMBOL_GPL(perf_event_enable
);
2566 struct stop_event_data
{
2567 struct perf_event
*event
;
2568 unsigned int restart
;
2571 static int __perf_event_stop(void *info
)
2573 struct stop_event_data
*sd
= info
;
2574 struct perf_event
*event
= sd
->event
;
2576 /* if it's already INACTIVE, do nothing */
2577 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2580 /* matches smp_wmb() in event_sched_in() */
2584 * There is a window with interrupts enabled before we get here,
2585 * so we need to check again lest we try to stop another CPU's event.
2587 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2590 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2593 * May race with the actual stop (through perf_pmu_output_stop()),
2594 * but it is only used for events with AUX ring buffer, and such
2595 * events will refuse to restart because of rb::aux_mmap_count==0,
2596 * see comments in perf_aux_output_begin().
2598 * Since this is happening on a event-local CPU, no trace is lost
2602 event
->pmu
->start(event
, 0);
2607 static int perf_event_stop(struct perf_event
*event
, int restart
)
2609 struct stop_event_data sd
= {
2616 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2619 /* matches smp_wmb() in event_sched_in() */
2623 * We only want to restart ACTIVE events, so if the event goes
2624 * inactive here (event->oncpu==-1), there's nothing more to do;
2625 * fall through with ret==-ENXIO.
2627 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2628 __perf_event_stop
, &sd
);
2629 } while (ret
== -EAGAIN
);
2635 * In order to contain the amount of racy and tricky in the address filter
2636 * configuration management, it is a two part process:
2638 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2639 * we update the addresses of corresponding vmas in
2640 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2641 * (p2) when an event is scheduled in (pmu::add), it calls
2642 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2643 * if the generation has changed since the previous call.
2645 * If (p1) happens while the event is active, we restart it to force (p2).
2647 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2648 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2650 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2651 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2653 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2656 void perf_event_addr_filters_sync(struct perf_event
*event
)
2658 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2660 if (!has_addr_filter(event
))
2663 raw_spin_lock(&ifh
->lock
);
2664 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2665 event
->pmu
->addr_filters_sync(event
);
2666 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2668 raw_spin_unlock(&ifh
->lock
);
2670 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2672 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2675 * not supported on inherited events
2677 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2680 atomic_add(refresh
, &event
->event_limit
);
2681 _perf_event_enable(event
);
2687 * See perf_event_disable()
2689 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2691 struct perf_event_context
*ctx
;
2694 ctx
= perf_event_ctx_lock(event
);
2695 ret
= _perf_event_refresh(event
, refresh
);
2696 perf_event_ctx_unlock(event
, ctx
);
2700 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2702 static void ctx_sched_out(struct perf_event_context
*ctx
,
2703 struct perf_cpu_context
*cpuctx
,
2704 enum event_type_t event_type
)
2706 int is_active
= ctx
->is_active
;
2707 struct perf_event
*event
;
2709 lockdep_assert_held(&ctx
->lock
);
2711 if (likely(!ctx
->nr_events
)) {
2713 * See __perf_remove_from_context().
2715 WARN_ON_ONCE(ctx
->is_active
);
2717 WARN_ON_ONCE(cpuctx
->task_ctx
);
2721 ctx
->is_active
&= ~event_type
;
2722 if (!(ctx
->is_active
& EVENT_ALL
))
2726 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2727 if (!ctx
->is_active
)
2728 cpuctx
->task_ctx
= NULL
;
2732 * Always update time if it was set; not only when it changes.
2733 * Otherwise we can 'forget' to update time for any but the last
2734 * context we sched out. For example:
2736 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2737 * ctx_sched_out(.event_type = EVENT_PINNED)
2739 * would only update time for the pinned events.
2741 if (is_active
& EVENT_TIME
) {
2742 /* update (and stop) ctx time */
2743 update_context_time(ctx
);
2744 update_cgrp_time_from_cpuctx(cpuctx
);
2747 is_active
^= ctx
->is_active
; /* changed bits */
2749 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2752 perf_pmu_disable(ctx
->pmu
);
2753 if (is_active
& EVENT_PINNED
) {
2754 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2755 group_sched_out(event
, cpuctx
, ctx
);
2758 if (is_active
& EVENT_FLEXIBLE
) {
2759 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2760 group_sched_out(event
, cpuctx
, ctx
);
2762 perf_pmu_enable(ctx
->pmu
);
2766 * Test whether two contexts are equivalent, i.e. whether they have both been
2767 * cloned from the same version of the same context.
2769 * Equivalence is measured using a generation number in the context that is
2770 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2771 * and list_del_event().
2773 static int context_equiv(struct perf_event_context
*ctx1
,
2774 struct perf_event_context
*ctx2
)
2776 lockdep_assert_held(&ctx1
->lock
);
2777 lockdep_assert_held(&ctx2
->lock
);
2779 /* Pinning disables the swap optimization */
2780 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2783 /* If ctx1 is the parent of ctx2 */
2784 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2787 /* If ctx2 is the parent of ctx1 */
2788 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2792 * If ctx1 and ctx2 have the same parent; we flatten the parent
2793 * hierarchy, see perf_event_init_context().
2795 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2796 ctx1
->parent_gen
== ctx2
->parent_gen
)
2803 static void __perf_event_sync_stat(struct perf_event
*event
,
2804 struct perf_event
*next_event
)
2808 if (!event
->attr
.inherit_stat
)
2812 * Update the event value, we cannot use perf_event_read()
2813 * because we're in the middle of a context switch and have IRQs
2814 * disabled, which upsets smp_call_function_single(), however
2815 * we know the event must be on the current CPU, therefore we
2816 * don't need to use it.
2818 switch (event
->state
) {
2819 case PERF_EVENT_STATE_ACTIVE
:
2820 event
->pmu
->read(event
);
2823 case PERF_EVENT_STATE_INACTIVE
:
2824 update_event_times(event
);
2832 * In order to keep per-task stats reliable we need to flip the event
2833 * values when we flip the contexts.
2835 value
= local64_read(&next_event
->count
);
2836 value
= local64_xchg(&event
->count
, value
);
2837 local64_set(&next_event
->count
, value
);
2839 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2840 swap(event
->total_time_running
, next_event
->total_time_running
);
2843 * Since we swizzled the values, update the user visible data too.
2845 perf_event_update_userpage(event
);
2846 perf_event_update_userpage(next_event
);
2849 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2850 struct perf_event_context
*next_ctx
)
2852 struct perf_event
*event
, *next_event
;
2857 update_context_time(ctx
);
2859 event
= list_first_entry(&ctx
->event_list
,
2860 struct perf_event
, event_entry
);
2862 next_event
= list_first_entry(&next_ctx
->event_list
,
2863 struct perf_event
, event_entry
);
2865 while (&event
->event_entry
!= &ctx
->event_list
&&
2866 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2868 __perf_event_sync_stat(event
, next_event
);
2870 event
= list_next_entry(event
, event_entry
);
2871 next_event
= list_next_entry(next_event
, event_entry
);
2875 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2876 struct task_struct
*next
)
2878 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2879 struct perf_event_context
*next_ctx
;
2880 struct perf_event_context
*parent
, *next_parent
;
2881 struct perf_cpu_context
*cpuctx
;
2887 cpuctx
= __get_cpu_context(ctx
);
2888 if (!cpuctx
->task_ctx
)
2892 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2896 parent
= rcu_dereference(ctx
->parent_ctx
);
2897 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2899 /* If neither context have a parent context; they cannot be clones. */
2900 if (!parent
&& !next_parent
)
2903 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2905 * Looks like the two contexts are clones, so we might be
2906 * able to optimize the context switch. We lock both
2907 * contexts and check that they are clones under the
2908 * lock (including re-checking that neither has been
2909 * uncloned in the meantime). It doesn't matter which
2910 * order we take the locks because no other cpu could
2911 * be trying to lock both of these tasks.
2913 raw_spin_lock(&ctx
->lock
);
2914 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2915 if (context_equiv(ctx
, next_ctx
)) {
2916 WRITE_ONCE(ctx
->task
, next
);
2917 WRITE_ONCE(next_ctx
->task
, task
);
2919 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2922 * RCU_INIT_POINTER here is safe because we've not
2923 * modified the ctx and the above modification of
2924 * ctx->task and ctx->task_ctx_data are immaterial
2925 * since those values are always verified under
2926 * ctx->lock which we're now holding.
2928 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2929 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2933 perf_event_sync_stat(ctx
, next_ctx
);
2935 raw_spin_unlock(&next_ctx
->lock
);
2936 raw_spin_unlock(&ctx
->lock
);
2942 raw_spin_lock(&ctx
->lock
);
2943 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2944 raw_spin_unlock(&ctx
->lock
);
2948 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2950 void perf_sched_cb_dec(struct pmu
*pmu
)
2952 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2954 this_cpu_dec(perf_sched_cb_usages
);
2956 if (!--cpuctx
->sched_cb_usage
)
2957 list_del(&cpuctx
->sched_cb_entry
);
2961 void perf_sched_cb_inc(struct pmu
*pmu
)
2963 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2965 if (!cpuctx
->sched_cb_usage
++)
2966 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2968 this_cpu_inc(perf_sched_cb_usages
);
2972 * This function provides the context switch callback to the lower code
2973 * layer. It is invoked ONLY when the context switch callback is enabled.
2975 * This callback is relevant even to per-cpu events; for example multi event
2976 * PEBS requires this to provide PID/TID information. This requires we flush
2977 * all queued PEBS records before we context switch to a new task.
2979 static void perf_pmu_sched_task(struct task_struct
*prev
,
2980 struct task_struct
*next
,
2983 struct perf_cpu_context
*cpuctx
;
2989 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2990 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2992 if (WARN_ON_ONCE(!pmu
->sched_task
))
2995 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2996 perf_pmu_disable(pmu
);
2998 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3000 perf_pmu_enable(pmu
);
3001 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3005 static void perf_event_switch(struct task_struct
*task
,
3006 struct task_struct
*next_prev
, bool sched_in
);
3008 #define for_each_task_context_nr(ctxn) \
3009 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3012 * Called from scheduler to remove the events of the current task,
3013 * with interrupts disabled.
3015 * We stop each event and update the event value in event->count.
3017 * This does not protect us against NMI, but disable()
3018 * sets the disabled bit in the control field of event _before_
3019 * accessing the event control register. If a NMI hits, then it will
3020 * not restart the event.
3022 void __perf_event_task_sched_out(struct task_struct
*task
,
3023 struct task_struct
*next
)
3027 if (__this_cpu_read(perf_sched_cb_usages
))
3028 perf_pmu_sched_task(task
, next
, false);
3030 if (atomic_read(&nr_switch_events
))
3031 perf_event_switch(task
, next
, false);
3033 for_each_task_context_nr(ctxn
)
3034 perf_event_context_sched_out(task
, ctxn
, next
);
3037 * if cgroup events exist on this CPU, then we need
3038 * to check if we have to switch out PMU state.
3039 * cgroup event are system-wide mode only
3041 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3042 perf_cgroup_sched_out(task
, next
);
3046 * Called with IRQs disabled
3048 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3049 enum event_type_t event_type
)
3051 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3055 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3056 struct perf_cpu_context
*cpuctx
)
3058 struct perf_event
*event
;
3060 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3061 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3063 if (!event_filter_match(event
))
3066 /* may need to reset tstamp_enabled */
3067 if (is_cgroup_event(event
))
3068 perf_cgroup_mark_enabled(event
, ctx
);
3070 if (group_can_go_on(event
, cpuctx
, 1))
3071 group_sched_in(event
, cpuctx
, ctx
);
3074 * If this pinned group hasn't been scheduled,
3075 * put it in error state.
3077 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3078 update_group_times(event
);
3079 event
->state
= PERF_EVENT_STATE_ERROR
;
3085 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3086 struct perf_cpu_context
*cpuctx
)
3088 struct perf_event
*event
;
3091 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3092 /* Ignore events in OFF or ERROR state */
3093 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3096 * Listen to the 'cpu' scheduling filter constraint
3099 if (!event_filter_match(event
))
3102 /* may need to reset tstamp_enabled */
3103 if (is_cgroup_event(event
))
3104 perf_cgroup_mark_enabled(event
, ctx
);
3106 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3107 if (group_sched_in(event
, cpuctx
, ctx
))
3114 ctx_sched_in(struct perf_event_context
*ctx
,
3115 struct perf_cpu_context
*cpuctx
,
3116 enum event_type_t event_type
,
3117 struct task_struct
*task
)
3119 int is_active
= ctx
->is_active
;
3122 lockdep_assert_held(&ctx
->lock
);
3124 if (likely(!ctx
->nr_events
))
3127 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3130 cpuctx
->task_ctx
= ctx
;
3132 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3135 is_active
^= ctx
->is_active
; /* changed bits */
3137 if (is_active
& EVENT_TIME
) {
3138 /* start ctx time */
3140 ctx
->timestamp
= now
;
3141 perf_cgroup_set_timestamp(task
, ctx
);
3145 * First go through the list and put on any pinned groups
3146 * in order to give them the best chance of going on.
3148 if (is_active
& EVENT_PINNED
)
3149 ctx_pinned_sched_in(ctx
, cpuctx
);
3151 /* Then walk through the lower prio flexible groups */
3152 if (is_active
& EVENT_FLEXIBLE
)
3153 ctx_flexible_sched_in(ctx
, cpuctx
);
3156 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3157 enum event_type_t event_type
,
3158 struct task_struct
*task
)
3160 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3162 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3165 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3166 struct task_struct
*task
)
3168 struct perf_cpu_context
*cpuctx
;
3170 cpuctx
= __get_cpu_context(ctx
);
3171 if (cpuctx
->task_ctx
== ctx
)
3174 perf_ctx_lock(cpuctx
, ctx
);
3175 perf_pmu_disable(ctx
->pmu
);
3177 * We want to keep the following priority order:
3178 * cpu pinned (that don't need to move), task pinned,
3179 * cpu flexible, task flexible.
3181 * However, if task's ctx is not carrying any pinned
3182 * events, no need to flip the cpuctx's events around.
3184 if (!list_empty(&ctx
->pinned_groups
))
3185 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3186 perf_event_sched_in(cpuctx
, ctx
, task
);
3187 perf_pmu_enable(ctx
->pmu
);
3188 perf_ctx_unlock(cpuctx
, ctx
);
3192 * Called from scheduler to add the events of the current task
3193 * with interrupts disabled.
3195 * We restore the event value and then enable it.
3197 * This does not protect us against NMI, but enable()
3198 * sets the enabled bit in the control field of event _before_
3199 * accessing the event control register. If a NMI hits, then it will
3200 * keep the event running.
3202 void __perf_event_task_sched_in(struct task_struct
*prev
,
3203 struct task_struct
*task
)
3205 struct perf_event_context
*ctx
;
3209 * If cgroup events exist on this CPU, then we need to check if we have
3210 * to switch in PMU state; cgroup event are system-wide mode only.
3212 * Since cgroup events are CPU events, we must schedule these in before
3213 * we schedule in the task events.
3215 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3216 perf_cgroup_sched_in(prev
, task
);
3218 for_each_task_context_nr(ctxn
) {
3219 ctx
= task
->perf_event_ctxp
[ctxn
];
3223 perf_event_context_sched_in(ctx
, task
);
3226 if (atomic_read(&nr_switch_events
))
3227 perf_event_switch(task
, prev
, true);
3229 if (__this_cpu_read(perf_sched_cb_usages
))
3230 perf_pmu_sched_task(prev
, task
, true);
3233 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3235 u64 frequency
= event
->attr
.sample_freq
;
3236 u64 sec
= NSEC_PER_SEC
;
3237 u64 divisor
, dividend
;
3239 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3241 count_fls
= fls64(count
);
3242 nsec_fls
= fls64(nsec
);
3243 frequency_fls
= fls64(frequency
);
3247 * We got @count in @nsec, with a target of sample_freq HZ
3248 * the target period becomes:
3251 * period = -------------------
3252 * @nsec * sample_freq
3257 * Reduce accuracy by one bit such that @a and @b converge
3258 * to a similar magnitude.
3260 #define REDUCE_FLS(a, b) \
3262 if (a##_fls > b##_fls) { \
3272 * Reduce accuracy until either term fits in a u64, then proceed with
3273 * the other, so that finally we can do a u64/u64 division.
3275 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3276 REDUCE_FLS(nsec
, frequency
);
3277 REDUCE_FLS(sec
, count
);
3280 if (count_fls
+ sec_fls
> 64) {
3281 divisor
= nsec
* frequency
;
3283 while (count_fls
+ sec_fls
> 64) {
3284 REDUCE_FLS(count
, sec
);
3288 dividend
= count
* sec
;
3290 dividend
= count
* sec
;
3292 while (nsec_fls
+ frequency_fls
> 64) {
3293 REDUCE_FLS(nsec
, frequency
);
3297 divisor
= nsec
* frequency
;
3303 return div64_u64(dividend
, divisor
);
3306 static DEFINE_PER_CPU(int, perf_throttled_count
);
3307 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3309 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3311 struct hw_perf_event
*hwc
= &event
->hw
;
3312 s64 period
, sample_period
;
3315 period
= perf_calculate_period(event
, nsec
, count
);
3317 delta
= (s64
)(period
- hwc
->sample_period
);
3318 delta
= (delta
+ 7) / 8; /* low pass filter */
3320 sample_period
= hwc
->sample_period
+ delta
;
3325 hwc
->sample_period
= sample_period
;
3327 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3329 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3331 local64_set(&hwc
->period_left
, 0);
3334 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3339 * combine freq adjustment with unthrottling to avoid two passes over the
3340 * events. At the same time, make sure, having freq events does not change
3341 * the rate of unthrottling as that would introduce bias.
3343 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3346 struct perf_event
*event
;
3347 struct hw_perf_event
*hwc
;
3348 u64 now
, period
= TICK_NSEC
;
3352 * only need to iterate over all events iff:
3353 * - context have events in frequency mode (needs freq adjust)
3354 * - there are events to unthrottle on this cpu
3356 if (!(ctx
->nr_freq
|| needs_unthr
))
3359 raw_spin_lock(&ctx
->lock
);
3360 perf_pmu_disable(ctx
->pmu
);
3362 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3363 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3366 if (!event_filter_match(event
))
3369 perf_pmu_disable(event
->pmu
);
3373 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3374 hwc
->interrupts
= 0;
3375 perf_log_throttle(event
, 1);
3376 event
->pmu
->start(event
, 0);
3379 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3383 * stop the event and update event->count
3385 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3387 now
= local64_read(&event
->count
);
3388 delta
= now
- hwc
->freq_count_stamp
;
3389 hwc
->freq_count_stamp
= now
;
3393 * reload only if value has changed
3394 * we have stopped the event so tell that
3395 * to perf_adjust_period() to avoid stopping it
3399 perf_adjust_period(event
, period
, delta
, false);
3401 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3403 perf_pmu_enable(event
->pmu
);
3406 perf_pmu_enable(ctx
->pmu
);
3407 raw_spin_unlock(&ctx
->lock
);
3411 * Round-robin a context's events:
3413 static void rotate_ctx(struct perf_event_context
*ctx
)
3416 * Rotate the first entry last of non-pinned groups. Rotation might be
3417 * disabled by the inheritance code.
3419 if (!ctx
->rotate_disable
)
3420 list_rotate_left(&ctx
->flexible_groups
);
3423 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3425 struct perf_event_context
*ctx
= NULL
;
3428 if (cpuctx
->ctx
.nr_events
) {
3429 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3433 ctx
= cpuctx
->task_ctx
;
3434 if (ctx
&& ctx
->nr_events
) {
3435 if (ctx
->nr_events
!= ctx
->nr_active
)
3442 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3443 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3445 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3447 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3449 rotate_ctx(&cpuctx
->ctx
);
3453 perf_event_sched_in(cpuctx
, ctx
, current
);
3455 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3456 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3462 void perf_event_task_tick(void)
3464 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3465 struct perf_event_context
*ctx
, *tmp
;
3468 WARN_ON(!irqs_disabled());
3470 __this_cpu_inc(perf_throttled_seq
);
3471 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3472 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3474 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3475 perf_adjust_freq_unthr_context(ctx
, throttled
);
3478 static int event_enable_on_exec(struct perf_event
*event
,
3479 struct perf_event_context
*ctx
)
3481 if (!event
->attr
.enable_on_exec
)
3484 event
->attr
.enable_on_exec
= 0;
3485 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3488 __perf_event_mark_enabled(event
);
3494 * Enable all of a task's events that have been marked enable-on-exec.
3495 * This expects task == current.
3497 static void perf_event_enable_on_exec(int ctxn
)
3499 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3500 enum event_type_t event_type
= 0;
3501 struct perf_cpu_context
*cpuctx
;
3502 struct perf_event
*event
;
3503 unsigned long flags
;
3506 local_irq_save(flags
);
3507 ctx
= current
->perf_event_ctxp
[ctxn
];
3508 if (!ctx
|| !ctx
->nr_events
)
3511 cpuctx
= __get_cpu_context(ctx
);
3512 perf_ctx_lock(cpuctx
, ctx
);
3513 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3514 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3515 enabled
|= event_enable_on_exec(event
, ctx
);
3516 event_type
|= get_event_type(event
);
3520 * Unclone and reschedule this context if we enabled any event.
3523 clone_ctx
= unclone_ctx(ctx
);
3524 ctx_resched(cpuctx
, ctx
, event_type
);
3526 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3528 perf_ctx_unlock(cpuctx
, ctx
);
3531 local_irq_restore(flags
);
3537 struct perf_read_data
{
3538 struct perf_event
*event
;
3543 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3545 u16 local_pkg
, event_pkg
;
3547 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3548 int local_cpu
= smp_processor_id();
3550 event_pkg
= topology_physical_package_id(event_cpu
);
3551 local_pkg
= topology_physical_package_id(local_cpu
);
3553 if (event_pkg
== local_pkg
)
3561 * Cross CPU call to read the hardware event
3563 static void __perf_event_read(void *info
)
3565 struct perf_read_data
*data
= info
;
3566 struct perf_event
*sub
, *event
= data
->event
;
3567 struct perf_event_context
*ctx
= event
->ctx
;
3568 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3569 struct pmu
*pmu
= event
->pmu
;
3572 * If this is a task context, we need to check whether it is
3573 * the current task context of this cpu. If not it has been
3574 * scheduled out before the smp call arrived. In that case
3575 * event->count would have been updated to a recent sample
3576 * when the event was scheduled out.
3578 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3581 raw_spin_lock(&ctx
->lock
);
3582 if (ctx
->is_active
) {
3583 update_context_time(ctx
);
3584 update_cgrp_time_from_event(event
);
3587 update_event_times(event
);
3588 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3597 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3601 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3602 update_event_times(sub
);
3603 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3605 * Use sibling's PMU rather than @event's since
3606 * sibling could be on different (eg: software) PMU.
3608 sub
->pmu
->read(sub
);
3612 data
->ret
= pmu
->commit_txn(pmu
);
3615 raw_spin_unlock(&ctx
->lock
);
3618 static inline u64
perf_event_count(struct perf_event
*event
)
3620 if (event
->pmu
->count
)
3621 return event
->pmu
->count(event
);
3623 return __perf_event_count(event
);
3627 * NMI-safe method to read a local event, that is an event that
3629 * - either for the current task, or for this CPU
3630 * - does not have inherit set, for inherited task events
3631 * will not be local and we cannot read them atomically
3632 * - must not have a pmu::count method
3634 u64
perf_event_read_local(struct perf_event
*event
)
3636 unsigned long flags
;
3640 * Disabling interrupts avoids all counter scheduling (context
3641 * switches, timer based rotation and IPIs).
3643 local_irq_save(flags
);
3645 /* If this is a per-task event, it must be for current */
3646 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3647 event
->hw
.target
!= current
);
3649 /* If this is a per-CPU event, it must be for this CPU */
3650 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3651 event
->cpu
!= smp_processor_id());
3654 * It must not be an event with inherit set, we cannot read
3655 * all child counters from atomic context.
3657 WARN_ON_ONCE(event
->attr
.inherit
);
3660 * It must not have a pmu::count method, those are not
3663 WARN_ON_ONCE(event
->pmu
->count
);
3666 * If the event is currently on this CPU, its either a per-task event,
3667 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3670 if (event
->oncpu
== smp_processor_id())
3671 event
->pmu
->read(event
);
3673 val
= local64_read(&event
->count
);
3674 local_irq_restore(flags
);
3679 static int perf_event_read(struct perf_event
*event
, bool group
)
3681 int event_cpu
, ret
= 0;
3684 * If event is enabled and currently active on a CPU, update the
3685 * value in the event structure:
3687 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3688 struct perf_read_data data
= {
3694 event_cpu
= READ_ONCE(event
->oncpu
);
3695 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3699 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3702 * Purposely ignore the smp_call_function_single() return
3705 * If event_cpu isn't a valid CPU it means the event got
3706 * scheduled out and that will have updated the event count.
3708 * Therefore, either way, we'll have an up-to-date event count
3711 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3714 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3715 struct perf_event_context
*ctx
= event
->ctx
;
3716 unsigned long flags
;
3718 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3720 * may read while context is not active
3721 * (e.g., thread is blocked), in that case
3722 * we cannot update context time
3724 if (ctx
->is_active
) {
3725 update_context_time(ctx
);
3726 update_cgrp_time_from_event(event
);
3729 update_group_times(event
);
3731 update_event_times(event
);
3732 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3739 * Initialize the perf_event context in a task_struct:
3741 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3743 raw_spin_lock_init(&ctx
->lock
);
3744 mutex_init(&ctx
->mutex
);
3745 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3746 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3747 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3748 INIT_LIST_HEAD(&ctx
->event_list
);
3749 atomic_set(&ctx
->refcount
, 1);
3752 static struct perf_event_context
*
3753 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3755 struct perf_event_context
*ctx
;
3757 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3761 __perf_event_init_context(ctx
);
3764 get_task_struct(task
);
3771 static struct task_struct
*
3772 find_lively_task_by_vpid(pid_t vpid
)
3774 struct task_struct
*task
;
3780 task
= find_task_by_vpid(vpid
);
3782 get_task_struct(task
);
3786 return ERR_PTR(-ESRCH
);
3792 * Returns a matching context with refcount and pincount.
3794 static struct perf_event_context
*
3795 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3796 struct perf_event
*event
)
3798 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3799 struct perf_cpu_context
*cpuctx
;
3800 void *task_ctx_data
= NULL
;
3801 unsigned long flags
;
3803 int cpu
= event
->cpu
;
3806 /* Must be root to operate on a CPU event: */
3807 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3808 return ERR_PTR(-EACCES
);
3811 * We could be clever and allow to attach a event to an
3812 * offline CPU and activate it when the CPU comes up, but
3815 if (!cpu_online(cpu
))
3816 return ERR_PTR(-ENODEV
);
3818 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3827 ctxn
= pmu
->task_ctx_nr
;
3831 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3832 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3833 if (!task_ctx_data
) {
3840 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3842 clone_ctx
= unclone_ctx(ctx
);
3845 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3846 ctx
->task_ctx_data
= task_ctx_data
;
3847 task_ctx_data
= NULL
;
3849 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3854 ctx
= alloc_perf_context(pmu
, task
);
3859 if (task_ctx_data
) {
3860 ctx
->task_ctx_data
= task_ctx_data
;
3861 task_ctx_data
= NULL
;
3865 mutex_lock(&task
->perf_event_mutex
);
3867 * If it has already passed perf_event_exit_task().
3868 * we must see PF_EXITING, it takes this mutex too.
3870 if (task
->flags
& PF_EXITING
)
3872 else if (task
->perf_event_ctxp
[ctxn
])
3877 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3879 mutex_unlock(&task
->perf_event_mutex
);
3881 if (unlikely(err
)) {
3890 kfree(task_ctx_data
);
3894 kfree(task_ctx_data
);
3895 return ERR_PTR(err
);
3898 static void perf_event_free_filter(struct perf_event
*event
);
3899 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3901 static void free_event_rcu(struct rcu_head
*head
)
3903 struct perf_event
*event
;
3905 event
= container_of(head
, struct perf_event
, rcu_head
);
3907 put_pid_ns(event
->ns
);
3908 perf_event_free_filter(event
);
3912 static void ring_buffer_attach(struct perf_event
*event
,
3913 struct ring_buffer
*rb
);
3915 static void detach_sb_event(struct perf_event
*event
)
3917 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3919 raw_spin_lock(&pel
->lock
);
3920 list_del_rcu(&event
->sb_list
);
3921 raw_spin_unlock(&pel
->lock
);
3924 static bool is_sb_event(struct perf_event
*event
)
3926 struct perf_event_attr
*attr
= &event
->attr
;
3931 if (event
->attach_state
& PERF_ATTACH_TASK
)
3934 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3935 attr
->comm
|| attr
->comm_exec
||
3937 attr
->context_switch
)
3942 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3944 if (is_sb_event(event
))
3945 detach_sb_event(event
);
3948 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3953 if (is_cgroup_event(event
))
3954 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3957 #ifdef CONFIG_NO_HZ_FULL
3958 static DEFINE_SPINLOCK(nr_freq_lock
);
3961 static void unaccount_freq_event_nohz(void)
3963 #ifdef CONFIG_NO_HZ_FULL
3964 spin_lock(&nr_freq_lock
);
3965 if (atomic_dec_and_test(&nr_freq_events
))
3966 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3967 spin_unlock(&nr_freq_lock
);
3971 static void unaccount_freq_event(void)
3973 if (tick_nohz_full_enabled())
3974 unaccount_freq_event_nohz();
3976 atomic_dec(&nr_freq_events
);
3979 static void unaccount_event(struct perf_event
*event
)
3986 if (event
->attach_state
& PERF_ATTACH_TASK
)
3988 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3989 atomic_dec(&nr_mmap_events
);
3990 if (event
->attr
.comm
)
3991 atomic_dec(&nr_comm_events
);
3992 if (event
->attr
.namespaces
)
3993 atomic_dec(&nr_namespaces_events
);
3994 if (event
->attr
.task
)
3995 atomic_dec(&nr_task_events
);
3996 if (event
->attr
.freq
)
3997 unaccount_freq_event();
3998 if (event
->attr
.context_switch
) {
4000 atomic_dec(&nr_switch_events
);
4002 if (is_cgroup_event(event
))
4004 if (has_branch_stack(event
))
4008 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4009 schedule_delayed_work(&perf_sched_work
, HZ
);
4012 unaccount_event_cpu(event
, event
->cpu
);
4014 unaccount_pmu_sb_event(event
);
4017 static void perf_sched_delayed(struct work_struct
*work
)
4019 mutex_lock(&perf_sched_mutex
);
4020 if (atomic_dec_and_test(&perf_sched_count
))
4021 static_branch_disable(&perf_sched_events
);
4022 mutex_unlock(&perf_sched_mutex
);
4026 * The following implement mutual exclusion of events on "exclusive" pmus
4027 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4028 * at a time, so we disallow creating events that might conflict, namely:
4030 * 1) cpu-wide events in the presence of per-task events,
4031 * 2) per-task events in the presence of cpu-wide events,
4032 * 3) two matching events on the same context.
4034 * The former two cases are handled in the allocation path (perf_event_alloc(),
4035 * _free_event()), the latter -- before the first perf_install_in_context().
4037 static int exclusive_event_init(struct perf_event
*event
)
4039 struct pmu
*pmu
= event
->pmu
;
4041 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4045 * Prevent co-existence of per-task and cpu-wide events on the
4046 * same exclusive pmu.
4048 * Negative pmu::exclusive_cnt means there are cpu-wide
4049 * events on this "exclusive" pmu, positive means there are
4052 * Since this is called in perf_event_alloc() path, event::ctx
4053 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4054 * to mean "per-task event", because unlike other attach states it
4055 * never gets cleared.
4057 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4058 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4061 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4068 static void exclusive_event_destroy(struct perf_event
*event
)
4070 struct pmu
*pmu
= event
->pmu
;
4072 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4075 /* see comment in exclusive_event_init() */
4076 if (event
->attach_state
& PERF_ATTACH_TASK
)
4077 atomic_dec(&pmu
->exclusive_cnt
);
4079 atomic_inc(&pmu
->exclusive_cnt
);
4082 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4084 if ((e1
->pmu
== e2
->pmu
) &&
4085 (e1
->cpu
== e2
->cpu
||
4092 /* Called under the same ctx::mutex as perf_install_in_context() */
4093 static bool exclusive_event_installable(struct perf_event
*event
,
4094 struct perf_event_context
*ctx
)
4096 struct perf_event
*iter_event
;
4097 struct pmu
*pmu
= event
->pmu
;
4099 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4102 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4103 if (exclusive_event_match(iter_event
, event
))
4110 static void perf_addr_filters_splice(struct perf_event
*event
,
4111 struct list_head
*head
);
4113 static void _free_event(struct perf_event
*event
)
4115 irq_work_sync(&event
->pending
);
4117 unaccount_event(event
);
4121 * Can happen when we close an event with re-directed output.
4123 * Since we have a 0 refcount, perf_mmap_close() will skip
4124 * over us; possibly making our ring_buffer_put() the last.
4126 mutex_lock(&event
->mmap_mutex
);
4127 ring_buffer_attach(event
, NULL
);
4128 mutex_unlock(&event
->mmap_mutex
);
4131 if (is_cgroup_event(event
))
4132 perf_detach_cgroup(event
);
4134 if (!event
->parent
) {
4135 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4136 put_callchain_buffers();
4139 perf_event_free_bpf_prog(event
);
4140 perf_addr_filters_splice(event
, NULL
);
4141 kfree(event
->addr_filters_offs
);
4144 event
->destroy(event
);
4147 put_ctx(event
->ctx
);
4149 exclusive_event_destroy(event
);
4150 module_put(event
->pmu
->module
);
4152 call_rcu(&event
->rcu_head
, free_event_rcu
);
4156 * Used to free events which have a known refcount of 1, such as in error paths
4157 * where the event isn't exposed yet and inherited events.
4159 static void free_event(struct perf_event
*event
)
4161 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4162 "unexpected event refcount: %ld; ptr=%p\n",
4163 atomic_long_read(&event
->refcount
), event
)) {
4164 /* leak to avoid use-after-free */
4172 * Remove user event from the owner task.
4174 static void perf_remove_from_owner(struct perf_event
*event
)
4176 struct task_struct
*owner
;
4180 * Matches the smp_store_release() in perf_event_exit_task(). If we
4181 * observe !owner it means the list deletion is complete and we can
4182 * indeed free this event, otherwise we need to serialize on
4183 * owner->perf_event_mutex.
4185 owner
= lockless_dereference(event
->owner
);
4188 * Since delayed_put_task_struct() also drops the last
4189 * task reference we can safely take a new reference
4190 * while holding the rcu_read_lock().
4192 get_task_struct(owner
);
4198 * If we're here through perf_event_exit_task() we're already
4199 * holding ctx->mutex which would be an inversion wrt. the
4200 * normal lock order.
4202 * However we can safely take this lock because its the child
4205 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4208 * We have to re-check the event->owner field, if it is cleared
4209 * we raced with perf_event_exit_task(), acquiring the mutex
4210 * ensured they're done, and we can proceed with freeing the
4214 list_del_init(&event
->owner_entry
);
4215 smp_store_release(&event
->owner
, NULL
);
4217 mutex_unlock(&owner
->perf_event_mutex
);
4218 put_task_struct(owner
);
4222 static void put_event(struct perf_event
*event
)
4224 if (!atomic_long_dec_and_test(&event
->refcount
))
4231 * Kill an event dead; while event:refcount will preserve the event
4232 * object, it will not preserve its functionality. Once the last 'user'
4233 * gives up the object, we'll destroy the thing.
4235 int perf_event_release_kernel(struct perf_event
*event
)
4237 struct perf_event_context
*ctx
= event
->ctx
;
4238 struct perf_event
*child
, *tmp
;
4241 * If we got here through err_file: fput(event_file); we will not have
4242 * attached to a context yet.
4245 WARN_ON_ONCE(event
->attach_state
&
4246 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4250 if (!is_kernel_event(event
))
4251 perf_remove_from_owner(event
);
4253 ctx
= perf_event_ctx_lock(event
);
4254 WARN_ON_ONCE(ctx
->parent_ctx
);
4255 perf_remove_from_context(event
, DETACH_GROUP
);
4257 raw_spin_lock_irq(&ctx
->lock
);
4259 * Mark this event as STATE_DEAD, there is no external reference to it
4262 * Anybody acquiring event->child_mutex after the below loop _must_
4263 * also see this, most importantly inherit_event() which will avoid
4264 * placing more children on the list.
4266 * Thus this guarantees that we will in fact observe and kill _ALL_
4269 event
->state
= PERF_EVENT_STATE_DEAD
;
4270 raw_spin_unlock_irq(&ctx
->lock
);
4272 perf_event_ctx_unlock(event
, ctx
);
4275 mutex_lock(&event
->child_mutex
);
4276 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4279 * Cannot change, child events are not migrated, see the
4280 * comment with perf_event_ctx_lock_nested().
4282 ctx
= lockless_dereference(child
->ctx
);
4284 * Since child_mutex nests inside ctx::mutex, we must jump
4285 * through hoops. We start by grabbing a reference on the ctx.
4287 * Since the event cannot get freed while we hold the
4288 * child_mutex, the context must also exist and have a !0
4294 * Now that we have a ctx ref, we can drop child_mutex, and
4295 * acquire ctx::mutex without fear of it going away. Then we
4296 * can re-acquire child_mutex.
4298 mutex_unlock(&event
->child_mutex
);
4299 mutex_lock(&ctx
->mutex
);
4300 mutex_lock(&event
->child_mutex
);
4303 * Now that we hold ctx::mutex and child_mutex, revalidate our
4304 * state, if child is still the first entry, it didn't get freed
4305 * and we can continue doing so.
4307 tmp
= list_first_entry_or_null(&event
->child_list
,
4308 struct perf_event
, child_list
);
4310 perf_remove_from_context(child
, DETACH_GROUP
);
4311 list_del(&child
->child_list
);
4314 * This matches the refcount bump in inherit_event();
4315 * this can't be the last reference.
4320 mutex_unlock(&event
->child_mutex
);
4321 mutex_unlock(&ctx
->mutex
);
4325 mutex_unlock(&event
->child_mutex
);
4328 put_event(event
); /* Must be the 'last' reference */
4331 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4334 * Called when the last reference to the file is gone.
4336 static int perf_release(struct inode
*inode
, struct file
*file
)
4338 perf_event_release_kernel(file
->private_data
);
4342 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4344 struct perf_event
*child
;
4350 mutex_lock(&event
->child_mutex
);
4352 (void)perf_event_read(event
, false);
4353 total
+= perf_event_count(event
);
4355 *enabled
+= event
->total_time_enabled
+
4356 atomic64_read(&event
->child_total_time_enabled
);
4357 *running
+= event
->total_time_running
+
4358 atomic64_read(&event
->child_total_time_running
);
4360 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4361 (void)perf_event_read(child
, false);
4362 total
+= perf_event_count(child
);
4363 *enabled
+= child
->total_time_enabled
;
4364 *running
+= child
->total_time_running
;
4366 mutex_unlock(&event
->child_mutex
);
4370 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4372 static int __perf_read_group_add(struct perf_event
*leader
,
4373 u64 read_format
, u64
*values
)
4375 struct perf_event
*sub
;
4376 int n
= 1; /* skip @nr */
4379 ret
= perf_event_read(leader
, true);
4384 * Since we co-schedule groups, {enabled,running} times of siblings
4385 * will be identical to those of the leader, so we only publish one
4388 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4389 values
[n
++] += leader
->total_time_enabled
+
4390 atomic64_read(&leader
->child_total_time_enabled
);
4393 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4394 values
[n
++] += leader
->total_time_running
+
4395 atomic64_read(&leader
->child_total_time_running
);
4399 * Write {count,id} tuples for every sibling.
4401 values
[n
++] += perf_event_count(leader
);
4402 if (read_format
& PERF_FORMAT_ID
)
4403 values
[n
++] = primary_event_id(leader
);
4405 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4406 values
[n
++] += perf_event_count(sub
);
4407 if (read_format
& PERF_FORMAT_ID
)
4408 values
[n
++] = primary_event_id(sub
);
4414 static int perf_read_group(struct perf_event
*event
,
4415 u64 read_format
, char __user
*buf
)
4417 struct perf_event
*leader
= event
->group_leader
, *child
;
4418 struct perf_event_context
*ctx
= leader
->ctx
;
4422 lockdep_assert_held(&ctx
->mutex
);
4424 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4428 values
[0] = 1 + leader
->nr_siblings
;
4431 * By locking the child_mutex of the leader we effectively
4432 * lock the child list of all siblings.. XXX explain how.
4434 mutex_lock(&leader
->child_mutex
);
4436 ret
= __perf_read_group_add(leader
, read_format
, values
);
4440 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4441 ret
= __perf_read_group_add(child
, read_format
, values
);
4446 mutex_unlock(&leader
->child_mutex
);
4448 ret
= event
->read_size
;
4449 if (copy_to_user(buf
, values
, event
->read_size
))
4454 mutex_unlock(&leader
->child_mutex
);
4460 static int perf_read_one(struct perf_event
*event
,
4461 u64 read_format
, char __user
*buf
)
4463 u64 enabled
, running
;
4467 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4468 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4469 values
[n
++] = enabled
;
4470 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4471 values
[n
++] = running
;
4472 if (read_format
& PERF_FORMAT_ID
)
4473 values
[n
++] = primary_event_id(event
);
4475 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4478 return n
* sizeof(u64
);
4481 static bool is_event_hup(struct perf_event
*event
)
4485 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4488 mutex_lock(&event
->child_mutex
);
4489 no_children
= list_empty(&event
->child_list
);
4490 mutex_unlock(&event
->child_mutex
);
4495 * Read the performance event - simple non blocking version for now
4498 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4500 u64 read_format
= event
->attr
.read_format
;
4504 * Return end-of-file for a read on a event that is in
4505 * error state (i.e. because it was pinned but it couldn't be
4506 * scheduled on to the CPU at some point).
4508 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4511 if (count
< event
->read_size
)
4514 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4515 if (read_format
& PERF_FORMAT_GROUP
)
4516 ret
= perf_read_group(event
, read_format
, buf
);
4518 ret
= perf_read_one(event
, read_format
, buf
);
4524 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4526 struct perf_event
*event
= file
->private_data
;
4527 struct perf_event_context
*ctx
;
4530 ctx
= perf_event_ctx_lock(event
);
4531 ret
= __perf_read(event
, buf
, count
);
4532 perf_event_ctx_unlock(event
, ctx
);
4537 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4539 struct perf_event
*event
= file
->private_data
;
4540 struct ring_buffer
*rb
;
4541 unsigned int events
= POLLHUP
;
4543 poll_wait(file
, &event
->waitq
, wait
);
4545 if (is_event_hup(event
))
4549 * Pin the event->rb by taking event->mmap_mutex; otherwise
4550 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4552 mutex_lock(&event
->mmap_mutex
);
4555 events
= atomic_xchg(&rb
->poll
, 0);
4556 mutex_unlock(&event
->mmap_mutex
);
4560 static void _perf_event_reset(struct perf_event
*event
)
4562 (void)perf_event_read(event
, false);
4563 local64_set(&event
->count
, 0);
4564 perf_event_update_userpage(event
);
4568 * Holding the top-level event's child_mutex means that any
4569 * descendant process that has inherited this event will block
4570 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4571 * task existence requirements of perf_event_enable/disable.
4573 static void perf_event_for_each_child(struct perf_event
*event
,
4574 void (*func
)(struct perf_event
*))
4576 struct perf_event
*child
;
4578 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4580 mutex_lock(&event
->child_mutex
);
4582 list_for_each_entry(child
, &event
->child_list
, child_list
)
4584 mutex_unlock(&event
->child_mutex
);
4587 static void perf_event_for_each(struct perf_event
*event
,
4588 void (*func
)(struct perf_event
*))
4590 struct perf_event_context
*ctx
= event
->ctx
;
4591 struct perf_event
*sibling
;
4593 lockdep_assert_held(&ctx
->mutex
);
4595 event
= event
->group_leader
;
4597 perf_event_for_each_child(event
, func
);
4598 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4599 perf_event_for_each_child(sibling
, func
);
4602 static void __perf_event_period(struct perf_event
*event
,
4603 struct perf_cpu_context
*cpuctx
,
4604 struct perf_event_context
*ctx
,
4607 u64 value
= *((u64
*)info
);
4610 if (event
->attr
.freq
) {
4611 event
->attr
.sample_freq
= value
;
4613 event
->attr
.sample_period
= value
;
4614 event
->hw
.sample_period
= value
;
4617 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4619 perf_pmu_disable(ctx
->pmu
);
4621 * We could be throttled; unthrottle now to avoid the tick
4622 * trying to unthrottle while we already re-started the event.
4624 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4625 event
->hw
.interrupts
= 0;
4626 perf_log_throttle(event
, 1);
4628 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4631 local64_set(&event
->hw
.period_left
, 0);
4634 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4635 perf_pmu_enable(ctx
->pmu
);
4639 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4643 if (!is_sampling_event(event
))
4646 if (copy_from_user(&value
, arg
, sizeof(value
)))
4652 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4655 event_function_call(event
, __perf_event_period
, &value
);
4660 static const struct file_operations perf_fops
;
4662 static inline int perf_fget_light(int fd
, struct fd
*p
)
4664 struct fd f
= fdget(fd
);
4668 if (f
.file
->f_op
!= &perf_fops
) {
4676 static int perf_event_set_output(struct perf_event
*event
,
4677 struct perf_event
*output_event
);
4678 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4679 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4681 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4683 void (*func
)(struct perf_event
*);
4687 case PERF_EVENT_IOC_ENABLE
:
4688 func
= _perf_event_enable
;
4690 case PERF_EVENT_IOC_DISABLE
:
4691 func
= _perf_event_disable
;
4693 case PERF_EVENT_IOC_RESET
:
4694 func
= _perf_event_reset
;
4697 case PERF_EVENT_IOC_REFRESH
:
4698 return _perf_event_refresh(event
, arg
);
4700 case PERF_EVENT_IOC_PERIOD
:
4701 return perf_event_period(event
, (u64 __user
*)arg
);
4703 case PERF_EVENT_IOC_ID
:
4705 u64 id
= primary_event_id(event
);
4707 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4712 case PERF_EVENT_IOC_SET_OUTPUT
:
4716 struct perf_event
*output_event
;
4718 ret
= perf_fget_light(arg
, &output
);
4721 output_event
= output
.file
->private_data
;
4722 ret
= perf_event_set_output(event
, output_event
);
4725 ret
= perf_event_set_output(event
, NULL
);
4730 case PERF_EVENT_IOC_SET_FILTER
:
4731 return perf_event_set_filter(event
, (void __user
*)arg
);
4733 case PERF_EVENT_IOC_SET_BPF
:
4734 return perf_event_set_bpf_prog(event
, arg
);
4736 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4737 struct ring_buffer
*rb
;
4740 rb
= rcu_dereference(event
->rb
);
4741 if (!rb
|| !rb
->nr_pages
) {
4745 rb_toggle_paused(rb
, !!arg
);
4753 if (flags
& PERF_IOC_FLAG_GROUP
)
4754 perf_event_for_each(event
, func
);
4756 perf_event_for_each_child(event
, func
);
4761 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4763 struct perf_event
*event
= file
->private_data
;
4764 struct perf_event_context
*ctx
;
4767 ctx
= perf_event_ctx_lock(event
);
4768 ret
= _perf_ioctl(event
, cmd
, arg
);
4769 perf_event_ctx_unlock(event
, ctx
);
4774 #ifdef CONFIG_COMPAT
4775 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4778 switch (_IOC_NR(cmd
)) {
4779 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4780 case _IOC_NR(PERF_EVENT_IOC_ID
):
4781 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4782 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4783 cmd
&= ~IOCSIZE_MASK
;
4784 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4788 return perf_ioctl(file
, cmd
, arg
);
4791 # define perf_compat_ioctl NULL
4794 int perf_event_task_enable(void)
4796 struct perf_event_context
*ctx
;
4797 struct perf_event
*event
;
4799 mutex_lock(¤t
->perf_event_mutex
);
4800 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4801 ctx
= perf_event_ctx_lock(event
);
4802 perf_event_for_each_child(event
, _perf_event_enable
);
4803 perf_event_ctx_unlock(event
, ctx
);
4805 mutex_unlock(¤t
->perf_event_mutex
);
4810 int perf_event_task_disable(void)
4812 struct perf_event_context
*ctx
;
4813 struct perf_event
*event
;
4815 mutex_lock(¤t
->perf_event_mutex
);
4816 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4817 ctx
= perf_event_ctx_lock(event
);
4818 perf_event_for_each_child(event
, _perf_event_disable
);
4819 perf_event_ctx_unlock(event
, ctx
);
4821 mutex_unlock(¤t
->perf_event_mutex
);
4826 static int perf_event_index(struct perf_event
*event
)
4828 if (event
->hw
.state
& PERF_HES_STOPPED
)
4831 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4834 return event
->pmu
->event_idx(event
);
4837 static void calc_timer_values(struct perf_event
*event
,
4844 *now
= perf_clock();
4845 ctx_time
= event
->shadow_ctx_time
+ *now
;
4846 *enabled
= ctx_time
- event
->tstamp_enabled
;
4847 *running
= ctx_time
- event
->tstamp_running
;
4850 static void perf_event_init_userpage(struct perf_event
*event
)
4852 struct perf_event_mmap_page
*userpg
;
4853 struct ring_buffer
*rb
;
4856 rb
= rcu_dereference(event
->rb
);
4860 userpg
= rb
->user_page
;
4862 /* Allow new userspace to detect that bit 0 is deprecated */
4863 userpg
->cap_bit0_is_deprecated
= 1;
4864 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4865 userpg
->data_offset
= PAGE_SIZE
;
4866 userpg
->data_size
= perf_data_size(rb
);
4872 void __weak
arch_perf_update_userpage(
4873 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4878 * Callers need to ensure there can be no nesting of this function, otherwise
4879 * the seqlock logic goes bad. We can not serialize this because the arch
4880 * code calls this from NMI context.
4882 void perf_event_update_userpage(struct perf_event
*event
)
4884 struct perf_event_mmap_page
*userpg
;
4885 struct ring_buffer
*rb
;
4886 u64 enabled
, running
, now
;
4889 rb
= rcu_dereference(event
->rb
);
4894 * compute total_time_enabled, total_time_running
4895 * based on snapshot values taken when the event
4896 * was last scheduled in.
4898 * we cannot simply called update_context_time()
4899 * because of locking issue as we can be called in
4902 calc_timer_values(event
, &now
, &enabled
, &running
);
4904 userpg
= rb
->user_page
;
4906 * Disable preemption so as to not let the corresponding user-space
4907 * spin too long if we get preempted.
4912 userpg
->index
= perf_event_index(event
);
4913 userpg
->offset
= perf_event_count(event
);
4915 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4917 userpg
->time_enabled
= enabled
+
4918 atomic64_read(&event
->child_total_time_enabled
);
4920 userpg
->time_running
= running
+
4921 atomic64_read(&event
->child_total_time_running
);
4923 arch_perf_update_userpage(event
, userpg
, now
);
4932 static int perf_mmap_fault(struct vm_fault
*vmf
)
4934 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4935 struct ring_buffer
*rb
;
4936 int ret
= VM_FAULT_SIGBUS
;
4938 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4939 if (vmf
->pgoff
== 0)
4945 rb
= rcu_dereference(event
->rb
);
4949 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4952 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4956 get_page(vmf
->page
);
4957 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4958 vmf
->page
->index
= vmf
->pgoff
;
4967 static void ring_buffer_attach(struct perf_event
*event
,
4968 struct ring_buffer
*rb
)
4970 struct ring_buffer
*old_rb
= NULL
;
4971 unsigned long flags
;
4975 * Should be impossible, we set this when removing
4976 * event->rb_entry and wait/clear when adding event->rb_entry.
4978 WARN_ON_ONCE(event
->rcu_pending
);
4981 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4982 list_del_rcu(&event
->rb_entry
);
4983 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4985 event
->rcu_batches
= get_state_synchronize_rcu();
4986 event
->rcu_pending
= 1;
4990 if (event
->rcu_pending
) {
4991 cond_synchronize_rcu(event
->rcu_batches
);
4992 event
->rcu_pending
= 0;
4995 spin_lock_irqsave(&rb
->event_lock
, flags
);
4996 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4997 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5001 * Avoid racing with perf_mmap_close(AUX): stop the event
5002 * before swizzling the event::rb pointer; if it's getting
5003 * unmapped, its aux_mmap_count will be 0 and it won't
5004 * restart. See the comment in __perf_pmu_output_stop().
5006 * Data will inevitably be lost when set_output is done in
5007 * mid-air, but then again, whoever does it like this is
5008 * not in for the data anyway.
5011 perf_event_stop(event
, 0);
5013 rcu_assign_pointer(event
->rb
, rb
);
5016 ring_buffer_put(old_rb
);
5018 * Since we detached before setting the new rb, so that we
5019 * could attach the new rb, we could have missed a wakeup.
5022 wake_up_all(&event
->waitq
);
5026 static void ring_buffer_wakeup(struct perf_event
*event
)
5028 struct ring_buffer
*rb
;
5031 rb
= rcu_dereference(event
->rb
);
5033 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5034 wake_up_all(&event
->waitq
);
5039 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5041 struct ring_buffer
*rb
;
5044 rb
= rcu_dereference(event
->rb
);
5046 if (!atomic_inc_not_zero(&rb
->refcount
))
5054 void ring_buffer_put(struct ring_buffer
*rb
)
5056 if (!atomic_dec_and_test(&rb
->refcount
))
5059 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5061 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5064 static void perf_mmap_open(struct vm_area_struct
*vma
)
5066 struct perf_event
*event
= vma
->vm_file
->private_data
;
5068 atomic_inc(&event
->mmap_count
);
5069 atomic_inc(&event
->rb
->mmap_count
);
5072 atomic_inc(&event
->rb
->aux_mmap_count
);
5074 if (event
->pmu
->event_mapped
)
5075 event
->pmu
->event_mapped(event
);
5078 static void perf_pmu_output_stop(struct perf_event
*event
);
5081 * A buffer can be mmap()ed multiple times; either directly through the same
5082 * event, or through other events by use of perf_event_set_output().
5084 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5085 * the buffer here, where we still have a VM context. This means we need
5086 * to detach all events redirecting to us.
5088 static void perf_mmap_close(struct vm_area_struct
*vma
)
5090 struct perf_event
*event
= vma
->vm_file
->private_data
;
5092 struct ring_buffer
*rb
= ring_buffer_get(event
);
5093 struct user_struct
*mmap_user
= rb
->mmap_user
;
5094 int mmap_locked
= rb
->mmap_locked
;
5095 unsigned long size
= perf_data_size(rb
);
5097 if (event
->pmu
->event_unmapped
)
5098 event
->pmu
->event_unmapped(event
);
5101 * rb->aux_mmap_count will always drop before rb->mmap_count and
5102 * event->mmap_count, so it is ok to use event->mmap_mutex to
5103 * serialize with perf_mmap here.
5105 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5106 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5108 * Stop all AUX events that are writing to this buffer,
5109 * so that we can free its AUX pages and corresponding PMU
5110 * data. Note that after rb::aux_mmap_count dropped to zero,
5111 * they won't start any more (see perf_aux_output_begin()).
5113 perf_pmu_output_stop(event
);
5115 /* now it's safe to free the pages */
5116 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5117 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5119 /* this has to be the last one */
5121 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5123 mutex_unlock(&event
->mmap_mutex
);
5126 atomic_dec(&rb
->mmap_count
);
5128 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5131 ring_buffer_attach(event
, NULL
);
5132 mutex_unlock(&event
->mmap_mutex
);
5134 /* If there's still other mmap()s of this buffer, we're done. */
5135 if (atomic_read(&rb
->mmap_count
))
5139 * No other mmap()s, detach from all other events that might redirect
5140 * into the now unreachable buffer. Somewhat complicated by the
5141 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5145 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5146 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5148 * This event is en-route to free_event() which will
5149 * detach it and remove it from the list.
5155 mutex_lock(&event
->mmap_mutex
);
5157 * Check we didn't race with perf_event_set_output() which can
5158 * swizzle the rb from under us while we were waiting to
5159 * acquire mmap_mutex.
5161 * If we find a different rb; ignore this event, a next
5162 * iteration will no longer find it on the list. We have to
5163 * still restart the iteration to make sure we're not now
5164 * iterating the wrong list.
5166 if (event
->rb
== rb
)
5167 ring_buffer_attach(event
, NULL
);
5169 mutex_unlock(&event
->mmap_mutex
);
5173 * Restart the iteration; either we're on the wrong list or
5174 * destroyed its integrity by doing a deletion.
5181 * It could be there's still a few 0-ref events on the list; they'll
5182 * get cleaned up by free_event() -- they'll also still have their
5183 * ref on the rb and will free it whenever they are done with it.
5185 * Aside from that, this buffer is 'fully' detached and unmapped,
5186 * undo the VM accounting.
5189 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5190 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5191 free_uid(mmap_user
);
5194 ring_buffer_put(rb
); /* could be last */
5197 static const struct vm_operations_struct perf_mmap_vmops
= {
5198 .open
= perf_mmap_open
,
5199 .close
= perf_mmap_close
, /* non mergable */
5200 .fault
= perf_mmap_fault
,
5201 .page_mkwrite
= perf_mmap_fault
,
5204 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5206 struct perf_event
*event
= file
->private_data
;
5207 unsigned long user_locked
, user_lock_limit
;
5208 struct user_struct
*user
= current_user();
5209 unsigned long locked
, lock_limit
;
5210 struct ring_buffer
*rb
= NULL
;
5211 unsigned long vma_size
;
5212 unsigned long nr_pages
;
5213 long user_extra
= 0, extra
= 0;
5214 int ret
= 0, flags
= 0;
5217 * Don't allow mmap() of inherited per-task counters. This would
5218 * create a performance issue due to all children writing to the
5221 if (event
->cpu
== -1 && event
->attr
.inherit
)
5224 if (!(vma
->vm_flags
& VM_SHARED
))
5227 vma_size
= vma
->vm_end
- vma
->vm_start
;
5229 if (vma
->vm_pgoff
== 0) {
5230 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5233 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5234 * mapped, all subsequent mappings should have the same size
5235 * and offset. Must be above the normal perf buffer.
5237 u64 aux_offset
, aux_size
;
5242 nr_pages
= vma_size
/ PAGE_SIZE
;
5244 mutex_lock(&event
->mmap_mutex
);
5251 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5252 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5254 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5257 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5260 /* already mapped with a different offset */
5261 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5264 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5267 /* already mapped with a different size */
5268 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5271 if (!is_power_of_2(nr_pages
))
5274 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5277 if (rb_has_aux(rb
)) {
5278 atomic_inc(&rb
->aux_mmap_count
);
5283 atomic_set(&rb
->aux_mmap_count
, 1);
5284 user_extra
= nr_pages
;
5290 * If we have rb pages ensure they're a power-of-two number, so we
5291 * can do bitmasks instead of modulo.
5293 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5296 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5299 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5301 mutex_lock(&event
->mmap_mutex
);
5303 if (event
->rb
->nr_pages
!= nr_pages
) {
5308 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5310 * Raced against perf_mmap_close() through
5311 * perf_event_set_output(). Try again, hope for better
5314 mutex_unlock(&event
->mmap_mutex
);
5321 user_extra
= nr_pages
+ 1;
5324 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5327 * Increase the limit linearly with more CPUs:
5329 user_lock_limit
*= num_online_cpus();
5331 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5333 if (user_locked
> user_lock_limit
)
5334 extra
= user_locked
- user_lock_limit
;
5336 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5337 lock_limit
>>= PAGE_SHIFT
;
5338 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5340 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5341 !capable(CAP_IPC_LOCK
)) {
5346 WARN_ON(!rb
&& event
->rb
);
5348 if (vma
->vm_flags
& VM_WRITE
)
5349 flags
|= RING_BUFFER_WRITABLE
;
5352 rb
= rb_alloc(nr_pages
,
5353 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5361 atomic_set(&rb
->mmap_count
, 1);
5362 rb
->mmap_user
= get_current_user();
5363 rb
->mmap_locked
= extra
;
5365 ring_buffer_attach(event
, rb
);
5367 perf_event_init_userpage(event
);
5368 perf_event_update_userpage(event
);
5370 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5371 event
->attr
.aux_watermark
, flags
);
5373 rb
->aux_mmap_locked
= extra
;
5378 atomic_long_add(user_extra
, &user
->locked_vm
);
5379 vma
->vm_mm
->pinned_vm
+= extra
;
5381 atomic_inc(&event
->mmap_count
);
5383 atomic_dec(&rb
->mmap_count
);
5386 mutex_unlock(&event
->mmap_mutex
);
5389 * Since pinned accounting is per vm we cannot allow fork() to copy our
5392 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5393 vma
->vm_ops
= &perf_mmap_vmops
;
5395 if (event
->pmu
->event_mapped
)
5396 event
->pmu
->event_mapped(event
);
5401 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5403 struct inode
*inode
= file_inode(filp
);
5404 struct perf_event
*event
= filp
->private_data
;
5408 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5409 inode_unlock(inode
);
5417 static const struct file_operations perf_fops
= {
5418 .llseek
= no_llseek
,
5419 .release
= perf_release
,
5422 .unlocked_ioctl
= perf_ioctl
,
5423 .compat_ioctl
= perf_compat_ioctl
,
5425 .fasync
= perf_fasync
,
5431 * If there's data, ensure we set the poll() state and publish everything
5432 * to user-space before waking everybody up.
5435 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5437 /* only the parent has fasync state */
5439 event
= event
->parent
;
5440 return &event
->fasync
;
5443 void perf_event_wakeup(struct perf_event
*event
)
5445 ring_buffer_wakeup(event
);
5447 if (event
->pending_kill
) {
5448 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5449 event
->pending_kill
= 0;
5453 static void perf_pending_event(struct irq_work
*entry
)
5455 struct perf_event
*event
= container_of(entry
,
5456 struct perf_event
, pending
);
5459 rctx
= perf_swevent_get_recursion_context();
5461 * If we 'fail' here, that's OK, it means recursion is already disabled
5462 * and we won't recurse 'further'.
5465 if (event
->pending_disable
) {
5466 event
->pending_disable
= 0;
5467 perf_event_disable_local(event
);
5470 if (event
->pending_wakeup
) {
5471 event
->pending_wakeup
= 0;
5472 perf_event_wakeup(event
);
5476 perf_swevent_put_recursion_context(rctx
);
5480 * We assume there is only KVM supporting the callbacks.
5481 * Later on, we might change it to a list if there is
5482 * another virtualization implementation supporting the callbacks.
5484 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5486 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5488 perf_guest_cbs
= cbs
;
5491 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5493 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5495 perf_guest_cbs
= NULL
;
5498 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5501 perf_output_sample_regs(struct perf_output_handle
*handle
,
5502 struct pt_regs
*regs
, u64 mask
)
5505 DECLARE_BITMAP(_mask
, 64);
5507 bitmap_from_u64(_mask
, mask
);
5508 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5511 val
= perf_reg_value(regs
, bit
);
5512 perf_output_put(handle
, val
);
5516 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5517 struct pt_regs
*regs
,
5518 struct pt_regs
*regs_user_copy
)
5520 if (user_mode(regs
)) {
5521 regs_user
->abi
= perf_reg_abi(current
);
5522 regs_user
->regs
= regs
;
5523 } else if (current
->mm
) {
5524 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5526 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5527 regs_user
->regs
= NULL
;
5531 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5532 struct pt_regs
*regs
)
5534 regs_intr
->regs
= regs
;
5535 regs_intr
->abi
= perf_reg_abi(current
);
5540 * Get remaining task size from user stack pointer.
5542 * It'd be better to take stack vma map and limit this more
5543 * precisly, but there's no way to get it safely under interrupt,
5544 * so using TASK_SIZE as limit.
5546 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5548 unsigned long addr
= perf_user_stack_pointer(regs
);
5550 if (!addr
|| addr
>= TASK_SIZE
)
5553 return TASK_SIZE
- addr
;
5557 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5558 struct pt_regs
*regs
)
5562 /* No regs, no stack pointer, no dump. */
5567 * Check if we fit in with the requested stack size into the:
5569 * If we don't, we limit the size to the TASK_SIZE.
5571 * - remaining sample size
5572 * If we don't, we customize the stack size to
5573 * fit in to the remaining sample size.
5576 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5577 stack_size
= min(stack_size
, (u16
) task_size
);
5579 /* Current header size plus static size and dynamic size. */
5580 header_size
+= 2 * sizeof(u64
);
5582 /* Do we fit in with the current stack dump size? */
5583 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5585 * If we overflow the maximum size for the sample,
5586 * we customize the stack dump size to fit in.
5588 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5589 stack_size
= round_up(stack_size
, sizeof(u64
));
5596 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5597 struct pt_regs
*regs
)
5599 /* Case of a kernel thread, nothing to dump */
5602 perf_output_put(handle
, size
);
5611 * - the size requested by user or the best one we can fit
5612 * in to the sample max size
5614 * - user stack dump data
5616 * - the actual dumped size
5620 perf_output_put(handle
, dump_size
);
5623 sp
= perf_user_stack_pointer(regs
);
5624 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5625 dyn_size
= dump_size
- rem
;
5627 perf_output_skip(handle
, rem
);
5630 perf_output_put(handle
, dyn_size
);
5634 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5635 struct perf_sample_data
*data
,
5636 struct perf_event
*event
)
5638 u64 sample_type
= event
->attr
.sample_type
;
5640 data
->type
= sample_type
;
5641 header
->size
+= event
->id_header_size
;
5643 if (sample_type
& PERF_SAMPLE_TID
) {
5644 /* namespace issues */
5645 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5646 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5649 if (sample_type
& PERF_SAMPLE_TIME
)
5650 data
->time
= perf_event_clock(event
);
5652 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5653 data
->id
= primary_event_id(event
);
5655 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5656 data
->stream_id
= event
->id
;
5658 if (sample_type
& PERF_SAMPLE_CPU
) {
5659 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5660 data
->cpu_entry
.reserved
= 0;
5664 void perf_event_header__init_id(struct perf_event_header
*header
,
5665 struct perf_sample_data
*data
,
5666 struct perf_event
*event
)
5668 if (event
->attr
.sample_id_all
)
5669 __perf_event_header__init_id(header
, data
, event
);
5672 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5673 struct perf_sample_data
*data
)
5675 u64 sample_type
= data
->type
;
5677 if (sample_type
& PERF_SAMPLE_TID
)
5678 perf_output_put(handle
, data
->tid_entry
);
5680 if (sample_type
& PERF_SAMPLE_TIME
)
5681 perf_output_put(handle
, data
->time
);
5683 if (sample_type
& PERF_SAMPLE_ID
)
5684 perf_output_put(handle
, data
->id
);
5686 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5687 perf_output_put(handle
, data
->stream_id
);
5689 if (sample_type
& PERF_SAMPLE_CPU
)
5690 perf_output_put(handle
, data
->cpu_entry
);
5692 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5693 perf_output_put(handle
, data
->id
);
5696 void perf_event__output_id_sample(struct perf_event
*event
,
5697 struct perf_output_handle
*handle
,
5698 struct perf_sample_data
*sample
)
5700 if (event
->attr
.sample_id_all
)
5701 __perf_event__output_id_sample(handle
, sample
);
5704 static void perf_output_read_one(struct perf_output_handle
*handle
,
5705 struct perf_event
*event
,
5706 u64 enabled
, u64 running
)
5708 u64 read_format
= event
->attr
.read_format
;
5712 values
[n
++] = perf_event_count(event
);
5713 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5714 values
[n
++] = enabled
+
5715 atomic64_read(&event
->child_total_time_enabled
);
5717 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5718 values
[n
++] = running
+
5719 atomic64_read(&event
->child_total_time_running
);
5721 if (read_format
& PERF_FORMAT_ID
)
5722 values
[n
++] = primary_event_id(event
);
5724 __output_copy(handle
, values
, n
* sizeof(u64
));
5727 static void perf_output_read_group(struct perf_output_handle
*handle
,
5728 struct perf_event
*event
,
5729 u64 enabled
, u64 running
)
5731 struct perf_event
*leader
= event
->group_leader
, *sub
;
5732 u64 read_format
= event
->attr
.read_format
;
5736 values
[n
++] = 1 + leader
->nr_siblings
;
5738 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5739 values
[n
++] = enabled
;
5741 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5742 values
[n
++] = running
;
5744 if (leader
!= event
)
5745 leader
->pmu
->read(leader
);
5747 values
[n
++] = perf_event_count(leader
);
5748 if (read_format
& PERF_FORMAT_ID
)
5749 values
[n
++] = primary_event_id(leader
);
5751 __output_copy(handle
, values
, n
* sizeof(u64
));
5753 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5756 if ((sub
!= event
) &&
5757 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5758 sub
->pmu
->read(sub
);
5760 values
[n
++] = perf_event_count(sub
);
5761 if (read_format
& PERF_FORMAT_ID
)
5762 values
[n
++] = primary_event_id(sub
);
5764 __output_copy(handle
, values
, n
* sizeof(u64
));
5768 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5769 PERF_FORMAT_TOTAL_TIME_RUNNING)
5772 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5774 * The problem is that its both hard and excessively expensive to iterate the
5775 * child list, not to mention that its impossible to IPI the children running
5776 * on another CPU, from interrupt/NMI context.
5778 static void perf_output_read(struct perf_output_handle
*handle
,
5779 struct perf_event
*event
)
5781 u64 enabled
= 0, running
= 0, now
;
5782 u64 read_format
= event
->attr
.read_format
;
5785 * compute total_time_enabled, total_time_running
5786 * based on snapshot values taken when the event
5787 * was last scheduled in.
5789 * we cannot simply called update_context_time()
5790 * because of locking issue as we are called in
5793 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5794 calc_timer_values(event
, &now
, &enabled
, &running
);
5796 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5797 perf_output_read_group(handle
, event
, enabled
, running
);
5799 perf_output_read_one(handle
, event
, enabled
, running
);
5802 void perf_output_sample(struct perf_output_handle
*handle
,
5803 struct perf_event_header
*header
,
5804 struct perf_sample_data
*data
,
5805 struct perf_event
*event
)
5807 u64 sample_type
= data
->type
;
5809 perf_output_put(handle
, *header
);
5811 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5812 perf_output_put(handle
, data
->id
);
5814 if (sample_type
& PERF_SAMPLE_IP
)
5815 perf_output_put(handle
, data
->ip
);
5817 if (sample_type
& PERF_SAMPLE_TID
)
5818 perf_output_put(handle
, data
->tid_entry
);
5820 if (sample_type
& PERF_SAMPLE_TIME
)
5821 perf_output_put(handle
, data
->time
);
5823 if (sample_type
& PERF_SAMPLE_ADDR
)
5824 perf_output_put(handle
, data
->addr
);
5826 if (sample_type
& PERF_SAMPLE_ID
)
5827 perf_output_put(handle
, data
->id
);
5829 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5830 perf_output_put(handle
, data
->stream_id
);
5832 if (sample_type
& PERF_SAMPLE_CPU
)
5833 perf_output_put(handle
, data
->cpu_entry
);
5835 if (sample_type
& PERF_SAMPLE_PERIOD
)
5836 perf_output_put(handle
, data
->period
);
5838 if (sample_type
& PERF_SAMPLE_READ
)
5839 perf_output_read(handle
, event
);
5841 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5842 if (data
->callchain
) {
5845 if (data
->callchain
)
5846 size
+= data
->callchain
->nr
;
5848 size
*= sizeof(u64
);
5850 __output_copy(handle
, data
->callchain
, size
);
5853 perf_output_put(handle
, nr
);
5857 if (sample_type
& PERF_SAMPLE_RAW
) {
5858 struct perf_raw_record
*raw
= data
->raw
;
5861 struct perf_raw_frag
*frag
= &raw
->frag
;
5863 perf_output_put(handle
, raw
->size
);
5866 __output_custom(handle
, frag
->copy
,
5867 frag
->data
, frag
->size
);
5869 __output_copy(handle
, frag
->data
,
5872 if (perf_raw_frag_last(frag
))
5877 __output_skip(handle
, NULL
, frag
->pad
);
5883 .size
= sizeof(u32
),
5886 perf_output_put(handle
, raw
);
5890 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5891 if (data
->br_stack
) {
5894 size
= data
->br_stack
->nr
5895 * sizeof(struct perf_branch_entry
);
5897 perf_output_put(handle
, data
->br_stack
->nr
);
5898 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5901 * we always store at least the value of nr
5904 perf_output_put(handle
, nr
);
5908 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5909 u64 abi
= data
->regs_user
.abi
;
5912 * If there are no regs to dump, notice it through
5913 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5915 perf_output_put(handle
, abi
);
5918 u64 mask
= event
->attr
.sample_regs_user
;
5919 perf_output_sample_regs(handle
,
5920 data
->regs_user
.regs
,
5925 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5926 perf_output_sample_ustack(handle
,
5927 data
->stack_user_size
,
5928 data
->regs_user
.regs
);
5931 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5932 perf_output_put(handle
, data
->weight
);
5934 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5935 perf_output_put(handle
, data
->data_src
.val
);
5937 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5938 perf_output_put(handle
, data
->txn
);
5940 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5941 u64 abi
= data
->regs_intr
.abi
;
5943 * If there are no regs to dump, notice it through
5944 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5946 perf_output_put(handle
, abi
);
5949 u64 mask
= event
->attr
.sample_regs_intr
;
5951 perf_output_sample_regs(handle
,
5952 data
->regs_intr
.regs
,
5957 if (!event
->attr
.watermark
) {
5958 int wakeup_events
= event
->attr
.wakeup_events
;
5960 if (wakeup_events
) {
5961 struct ring_buffer
*rb
= handle
->rb
;
5962 int events
= local_inc_return(&rb
->events
);
5964 if (events
>= wakeup_events
) {
5965 local_sub(wakeup_events
, &rb
->events
);
5966 local_inc(&rb
->wakeup
);
5972 void perf_prepare_sample(struct perf_event_header
*header
,
5973 struct perf_sample_data
*data
,
5974 struct perf_event
*event
,
5975 struct pt_regs
*regs
)
5977 u64 sample_type
= event
->attr
.sample_type
;
5979 header
->type
= PERF_RECORD_SAMPLE
;
5980 header
->size
= sizeof(*header
) + event
->header_size
;
5983 header
->misc
|= perf_misc_flags(regs
);
5985 __perf_event_header__init_id(header
, data
, event
);
5987 if (sample_type
& PERF_SAMPLE_IP
)
5988 data
->ip
= perf_instruction_pointer(regs
);
5990 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5993 data
->callchain
= perf_callchain(event
, regs
);
5995 if (data
->callchain
)
5996 size
+= data
->callchain
->nr
;
5998 header
->size
+= size
* sizeof(u64
);
6001 if (sample_type
& PERF_SAMPLE_RAW
) {
6002 struct perf_raw_record
*raw
= data
->raw
;
6006 struct perf_raw_frag
*frag
= &raw
->frag
;
6011 if (perf_raw_frag_last(frag
))
6016 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6017 raw
->size
= size
- sizeof(u32
);
6018 frag
->pad
= raw
->size
- sum
;
6023 header
->size
+= size
;
6026 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6027 int size
= sizeof(u64
); /* nr */
6028 if (data
->br_stack
) {
6029 size
+= data
->br_stack
->nr
6030 * sizeof(struct perf_branch_entry
);
6032 header
->size
+= size
;
6035 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6036 perf_sample_regs_user(&data
->regs_user
, regs
,
6037 &data
->regs_user_copy
);
6039 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6040 /* regs dump ABI info */
6041 int size
= sizeof(u64
);
6043 if (data
->regs_user
.regs
) {
6044 u64 mask
= event
->attr
.sample_regs_user
;
6045 size
+= hweight64(mask
) * sizeof(u64
);
6048 header
->size
+= size
;
6051 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6053 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6054 * processed as the last one or have additional check added
6055 * in case new sample type is added, because we could eat
6056 * up the rest of the sample size.
6058 u16 stack_size
= event
->attr
.sample_stack_user
;
6059 u16 size
= sizeof(u64
);
6061 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6062 data
->regs_user
.regs
);
6065 * If there is something to dump, add space for the dump
6066 * itself and for the field that tells the dynamic size,
6067 * which is how many have been actually dumped.
6070 size
+= sizeof(u64
) + stack_size
;
6072 data
->stack_user_size
= stack_size
;
6073 header
->size
+= size
;
6076 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6077 /* regs dump ABI info */
6078 int size
= sizeof(u64
);
6080 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6082 if (data
->regs_intr
.regs
) {
6083 u64 mask
= event
->attr
.sample_regs_intr
;
6085 size
+= hweight64(mask
) * sizeof(u64
);
6088 header
->size
+= size
;
6092 static void __always_inline
6093 __perf_event_output(struct perf_event
*event
,
6094 struct perf_sample_data
*data
,
6095 struct pt_regs
*regs
,
6096 int (*output_begin
)(struct perf_output_handle
*,
6097 struct perf_event
*,
6100 struct perf_output_handle handle
;
6101 struct perf_event_header header
;
6103 /* protect the callchain buffers */
6106 perf_prepare_sample(&header
, data
, event
, regs
);
6108 if (output_begin(&handle
, event
, header
.size
))
6111 perf_output_sample(&handle
, &header
, data
, event
);
6113 perf_output_end(&handle
);
6120 perf_event_output_forward(struct perf_event
*event
,
6121 struct perf_sample_data
*data
,
6122 struct pt_regs
*regs
)
6124 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6128 perf_event_output_backward(struct perf_event
*event
,
6129 struct perf_sample_data
*data
,
6130 struct pt_regs
*regs
)
6132 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6136 perf_event_output(struct perf_event
*event
,
6137 struct perf_sample_data
*data
,
6138 struct pt_regs
*regs
)
6140 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6147 struct perf_read_event
{
6148 struct perf_event_header header
;
6155 perf_event_read_event(struct perf_event
*event
,
6156 struct task_struct
*task
)
6158 struct perf_output_handle handle
;
6159 struct perf_sample_data sample
;
6160 struct perf_read_event read_event
= {
6162 .type
= PERF_RECORD_READ
,
6164 .size
= sizeof(read_event
) + event
->read_size
,
6166 .pid
= perf_event_pid(event
, task
),
6167 .tid
= perf_event_tid(event
, task
),
6171 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6172 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6176 perf_output_put(&handle
, read_event
);
6177 perf_output_read(&handle
, event
);
6178 perf_event__output_id_sample(event
, &handle
, &sample
);
6180 perf_output_end(&handle
);
6183 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6186 perf_iterate_ctx(struct perf_event_context
*ctx
,
6187 perf_iterate_f output
,
6188 void *data
, bool all
)
6190 struct perf_event
*event
;
6192 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6194 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6196 if (!event_filter_match(event
))
6200 output(event
, data
);
6204 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6206 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6207 struct perf_event
*event
;
6209 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6211 * Skip events that are not fully formed yet; ensure that
6212 * if we observe event->ctx, both event and ctx will be
6213 * complete enough. See perf_install_in_context().
6215 if (!smp_load_acquire(&event
->ctx
))
6218 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6220 if (!event_filter_match(event
))
6222 output(event
, data
);
6227 * Iterate all events that need to receive side-band events.
6229 * For new callers; ensure that account_pmu_sb_event() includes
6230 * your event, otherwise it might not get delivered.
6233 perf_iterate_sb(perf_iterate_f output
, void *data
,
6234 struct perf_event_context
*task_ctx
)
6236 struct perf_event_context
*ctx
;
6243 * If we have task_ctx != NULL we only notify the task context itself.
6244 * The task_ctx is set only for EXIT events before releasing task
6248 perf_iterate_ctx(task_ctx
, output
, data
, false);
6252 perf_iterate_sb_cpu(output
, data
);
6254 for_each_task_context_nr(ctxn
) {
6255 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6257 perf_iterate_ctx(ctx
, output
, data
, false);
6265 * Clear all file-based filters at exec, they'll have to be
6266 * re-instated when/if these objects are mmapped again.
6268 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6270 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6271 struct perf_addr_filter
*filter
;
6272 unsigned int restart
= 0, count
= 0;
6273 unsigned long flags
;
6275 if (!has_addr_filter(event
))
6278 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6279 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6280 if (filter
->inode
) {
6281 event
->addr_filters_offs
[count
] = 0;
6289 event
->addr_filters_gen
++;
6290 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6293 perf_event_stop(event
, 1);
6296 void perf_event_exec(void)
6298 struct perf_event_context
*ctx
;
6302 for_each_task_context_nr(ctxn
) {
6303 ctx
= current
->perf_event_ctxp
[ctxn
];
6307 perf_event_enable_on_exec(ctxn
);
6309 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6315 struct remote_output
{
6316 struct ring_buffer
*rb
;
6320 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6322 struct perf_event
*parent
= event
->parent
;
6323 struct remote_output
*ro
= data
;
6324 struct ring_buffer
*rb
= ro
->rb
;
6325 struct stop_event_data sd
= {
6329 if (!has_aux(event
))
6336 * In case of inheritance, it will be the parent that links to the
6337 * ring-buffer, but it will be the child that's actually using it.
6339 * We are using event::rb to determine if the event should be stopped,
6340 * however this may race with ring_buffer_attach() (through set_output),
6341 * which will make us skip the event that actually needs to be stopped.
6342 * So ring_buffer_attach() has to stop an aux event before re-assigning
6345 if (rcu_dereference(parent
->rb
) == rb
)
6346 ro
->err
= __perf_event_stop(&sd
);
6349 static int __perf_pmu_output_stop(void *info
)
6351 struct perf_event
*event
= info
;
6352 struct pmu
*pmu
= event
->pmu
;
6353 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6354 struct remote_output ro
= {
6359 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6360 if (cpuctx
->task_ctx
)
6361 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6368 static void perf_pmu_output_stop(struct perf_event
*event
)
6370 struct perf_event
*iter
;
6375 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6377 * For per-CPU events, we need to make sure that neither they
6378 * nor their children are running; for cpu==-1 events it's
6379 * sufficient to stop the event itself if it's active, since
6380 * it can't have children.
6384 cpu
= READ_ONCE(iter
->oncpu
);
6389 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6390 if (err
== -EAGAIN
) {
6399 * task tracking -- fork/exit
6401 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6404 struct perf_task_event
{
6405 struct task_struct
*task
;
6406 struct perf_event_context
*task_ctx
;
6409 struct perf_event_header header
;
6419 static int perf_event_task_match(struct perf_event
*event
)
6421 return event
->attr
.comm
|| event
->attr
.mmap
||
6422 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6426 static void perf_event_task_output(struct perf_event
*event
,
6429 struct perf_task_event
*task_event
= data
;
6430 struct perf_output_handle handle
;
6431 struct perf_sample_data sample
;
6432 struct task_struct
*task
= task_event
->task
;
6433 int ret
, size
= task_event
->event_id
.header
.size
;
6435 if (!perf_event_task_match(event
))
6438 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6440 ret
= perf_output_begin(&handle
, event
,
6441 task_event
->event_id
.header
.size
);
6445 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6446 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6448 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6449 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6451 task_event
->event_id
.time
= perf_event_clock(event
);
6453 perf_output_put(&handle
, task_event
->event_id
);
6455 perf_event__output_id_sample(event
, &handle
, &sample
);
6457 perf_output_end(&handle
);
6459 task_event
->event_id
.header
.size
= size
;
6462 static void perf_event_task(struct task_struct
*task
,
6463 struct perf_event_context
*task_ctx
,
6466 struct perf_task_event task_event
;
6468 if (!atomic_read(&nr_comm_events
) &&
6469 !atomic_read(&nr_mmap_events
) &&
6470 !atomic_read(&nr_task_events
))
6473 task_event
= (struct perf_task_event
){
6475 .task_ctx
= task_ctx
,
6478 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6480 .size
= sizeof(task_event
.event_id
),
6490 perf_iterate_sb(perf_event_task_output
,
6495 void perf_event_fork(struct task_struct
*task
)
6497 perf_event_task(task
, NULL
, 1);
6498 perf_event_namespaces(task
);
6505 struct perf_comm_event
{
6506 struct task_struct
*task
;
6511 struct perf_event_header header
;
6518 static int perf_event_comm_match(struct perf_event
*event
)
6520 return event
->attr
.comm
;
6523 static void perf_event_comm_output(struct perf_event
*event
,
6526 struct perf_comm_event
*comm_event
= data
;
6527 struct perf_output_handle handle
;
6528 struct perf_sample_data sample
;
6529 int size
= comm_event
->event_id
.header
.size
;
6532 if (!perf_event_comm_match(event
))
6535 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6536 ret
= perf_output_begin(&handle
, event
,
6537 comm_event
->event_id
.header
.size
);
6542 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6543 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6545 perf_output_put(&handle
, comm_event
->event_id
);
6546 __output_copy(&handle
, comm_event
->comm
,
6547 comm_event
->comm_size
);
6549 perf_event__output_id_sample(event
, &handle
, &sample
);
6551 perf_output_end(&handle
);
6553 comm_event
->event_id
.header
.size
= size
;
6556 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6558 char comm
[TASK_COMM_LEN
];
6561 memset(comm
, 0, sizeof(comm
));
6562 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6563 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6565 comm_event
->comm
= comm
;
6566 comm_event
->comm_size
= size
;
6568 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6570 perf_iterate_sb(perf_event_comm_output
,
6575 void perf_event_comm(struct task_struct
*task
, bool exec
)
6577 struct perf_comm_event comm_event
;
6579 if (!atomic_read(&nr_comm_events
))
6582 comm_event
= (struct perf_comm_event
){
6588 .type
= PERF_RECORD_COMM
,
6589 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6597 perf_event_comm_event(&comm_event
);
6601 * namespaces tracking
6604 struct perf_namespaces_event
{
6605 struct task_struct
*task
;
6608 struct perf_event_header header
;
6613 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6617 static int perf_event_namespaces_match(struct perf_event
*event
)
6619 return event
->attr
.namespaces
;
6622 static void perf_event_namespaces_output(struct perf_event
*event
,
6625 struct perf_namespaces_event
*namespaces_event
= data
;
6626 struct perf_output_handle handle
;
6627 struct perf_sample_data sample
;
6630 if (!perf_event_namespaces_match(event
))
6633 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6635 ret
= perf_output_begin(&handle
, event
,
6636 namespaces_event
->event_id
.header
.size
);
6640 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6641 namespaces_event
->task
);
6642 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6643 namespaces_event
->task
);
6645 perf_output_put(&handle
, namespaces_event
->event_id
);
6647 perf_event__output_id_sample(event
, &handle
, &sample
);
6649 perf_output_end(&handle
);
6652 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6653 struct task_struct
*task
,
6654 const struct proc_ns_operations
*ns_ops
)
6656 struct path ns_path
;
6657 struct inode
*ns_inode
;
6660 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6662 ns_inode
= ns_path
.dentry
->d_inode
;
6663 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6664 ns_link_info
->ino
= ns_inode
->i_ino
;
6668 void perf_event_namespaces(struct task_struct
*task
)
6670 struct perf_namespaces_event namespaces_event
;
6671 struct perf_ns_link_info
*ns_link_info
;
6673 if (!atomic_read(&nr_namespaces_events
))
6676 namespaces_event
= (struct perf_namespaces_event
){
6680 .type
= PERF_RECORD_NAMESPACES
,
6682 .size
= sizeof(namespaces_event
.event_id
),
6686 .nr_namespaces
= NR_NAMESPACES
,
6687 /* .link_info[NR_NAMESPACES] */
6691 ns_link_info
= namespaces_event
.event_id
.link_info
;
6693 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6694 task
, &mntns_operations
);
6696 #ifdef CONFIG_USER_NS
6697 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6698 task
, &userns_operations
);
6700 #ifdef CONFIG_NET_NS
6701 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6702 task
, &netns_operations
);
6704 #ifdef CONFIG_UTS_NS
6705 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6706 task
, &utsns_operations
);
6708 #ifdef CONFIG_IPC_NS
6709 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6710 task
, &ipcns_operations
);
6712 #ifdef CONFIG_PID_NS
6713 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6714 task
, &pidns_operations
);
6716 #ifdef CONFIG_CGROUPS
6717 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6718 task
, &cgroupns_operations
);
6721 perf_iterate_sb(perf_event_namespaces_output
,
6730 struct perf_mmap_event
{
6731 struct vm_area_struct
*vma
;
6733 const char *file_name
;
6741 struct perf_event_header header
;
6751 static int perf_event_mmap_match(struct perf_event
*event
,
6754 struct perf_mmap_event
*mmap_event
= data
;
6755 struct vm_area_struct
*vma
= mmap_event
->vma
;
6756 int executable
= vma
->vm_flags
& VM_EXEC
;
6758 return (!executable
&& event
->attr
.mmap_data
) ||
6759 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6762 static void perf_event_mmap_output(struct perf_event
*event
,
6765 struct perf_mmap_event
*mmap_event
= data
;
6766 struct perf_output_handle handle
;
6767 struct perf_sample_data sample
;
6768 int size
= mmap_event
->event_id
.header
.size
;
6771 if (!perf_event_mmap_match(event
, data
))
6774 if (event
->attr
.mmap2
) {
6775 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6776 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6777 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6778 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6779 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6780 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6781 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6784 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6785 ret
= perf_output_begin(&handle
, event
,
6786 mmap_event
->event_id
.header
.size
);
6790 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6791 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6793 perf_output_put(&handle
, mmap_event
->event_id
);
6795 if (event
->attr
.mmap2
) {
6796 perf_output_put(&handle
, mmap_event
->maj
);
6797 perf_output_put(&handle
, mmap_event
->min
);
6798 perf_output_put(&handle
, mmap_event
->ino
);
6799 perf_output_put(&handle
, mmap_event
->ino_generation
);
6800 perf_output_put(&handle
, mmap_event
->prot
);
6801 perf_output_put(&handle
, mmap_event
->flags
);
6804 __output_copy(&handle
, mmap_event
->file_name
,
6805 mmap_event
->file_size
);
6807 perf_event__output_id_sample(event
, &handle
, &sample
);
6809 perf_output_end(&handle
);
6811 mmap_event
->event_id
.header
.size
= size
;
6814 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6816 struct vm_area_struct
*vma
= mmap_event
->vma
;
6817 struct file
*file
= vma
->vm_file
;
6818 int maj
= 0, min
= 0;
6819 u64 ino
= 0, gen
= 0;
6820 u32 prot
= 0, flags
= 0;
6826 if (vma
->vm_flags
& VM_READ
)
6828 if (vma
->vm_flags
& VM_WRITE
)
6830 if (vma
->vm_flags
& VM_EXEC
)
6833 if (vma
->vm_flags
& VM_MAYSHARE
)
6836 flags
= MAP_PRIVATE
;
6838 if (vma
->vm_flags
& VM_DENYWRITE
)
6839 flags
|= MAP_DENYWRITE
;
6840 if (vma
->vm_flags
& VM_MAYEXEC
)
6841 flags
|= MAP_EXECUTABLE
;
6842 if (vma
->vm_flags
& VM_LOCKED
)
6843 flags
|= MAP_LOCKED
;
6844 if (vma
->vm_flags
& VM_HUGETLB
)
6845 flags
|= MAP_HUGETLB
;
6848 struct inode
*inode
;
6851 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6857 * d_path() works from the end of the rb backwards, so we
6858 * need to add enough zero bytes after the string to handle
6859 * the 64bit alignment we do later.
6861 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6866 inode
= file_inode(vma
->vm_file
);
6867 dev
= inode
->i_sb
->s_dev
;
6869 gen
= inode
->i_generation
;
6875 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6876 name
= (char *) vma
->vm_ops
->name(vma
);
6881 name
= (char *)arch_vma_name(vma
);
6885 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6886 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6890 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6891 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6901 strlcpy(tmp
, name
, sizeof(tmp
));
6905 * Since our buffer works in 8 byte units we need to align our string
6906 * size to a multiple of 8. However, we must guarantee the tail end is
6907 * zero'd out to avoid leaking random bits to userspace.
6909 size
= strlen(name
)+1;
6910 while (!IS_ALIGNED(size
, sizeof(u64
)))
6911 name
[size
++] = '\0';
6913 mmap_event
->file_name
= name
;
6914 mmap_event
->file_size
= size
;
6915 mmap_event
->maj
= maj
;
6916 mmap_event
->min
= min
;
6917 mmap_event
->ino
= ino
;
6918 mmap_event
->ino_generation
= gen
;
6919 mmap_event
->prot
= prot
;
6920 mmap_event
->flags
= flags
;
6922 if (!(vma
->vm_flags
& VM_EXEC
))
6923 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6925 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6927 perf_iterate_sb(perf_event_mmap_output
,
6935 * Check whether inode and address range match filter criteria.
6937 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6938 struct file
*file
, unsigned long offset
,
6941 if (filter
->inode
!= file_inode(file
))
6944 if (filter
->offset
> offset
+ size
)
6947 if (filter
->offset
+ filter
->size
< offset
)
6953 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6955 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6956 struct vm_area_struct
*vma
= data
;
6957 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6958 struct file
*file
= vma
->vm_file
;
6959 struct perf_addr_filter
*filter
;
6960 unsigned int restart
= 0, count
= 0;
6962 if (!has_addr_filter(event
))
6968 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6969 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6970 if (perf_addr_filter_match(filter
, file
, off
,
6971 vma
->vm_end
- vma
->vm_start
)) {
6972 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6980 event
->addr_filters_gen
++;
6981 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6984 perf_event_stop(event
, 1);
6988 * Adjust all task's events' filters to the new vma
6990 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6992 struct perf_event_context
*ctx
;
6996 * Data tracing isn't supported yet and as such there is no need
6997 * to keep track of anything that isn't related to executable code:
6999 if (!(vma
->vm_flags
& VM_EXEC
))
7003 for_each_task_context_nr(ctxn
) {
7004 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7008 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7013 void perf_event_mmap(struct vm_area_struct
*vma
)
7015 struct perf_mmap_event mmap_event
;
7017 if (!atomic_read(&nr_mmap_events
))
7020 mmap_event
= (struct perf_mmap_event
){
7026 .type
= PERF_RECORD_MMAP
,
7027 .misc
= PERF_RECORD_MISC_USER
,
7032 .start
= vma
->vm_start
,
7033 .len
= vma
->vm_end
- vma
->vm_start
,
7034 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7036 /* .maj (attr_mmap2 only) */
7037 /* .min (attr_mmap2 only) */
7038 /* .ino (attr_mmap2 only) */
7039 /* .ino_generation (attr_mmap2 only) */
7040 /* .prot (attr_mmap2 only) */
7041 /* .flags (attr_mmap2 only) */
7044 perf_addr_filters_adjust(vma
);
7045 perf_event_mmap_event(&mmap_event
);
7048 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7049 unsigned long size
, u64 flags
)
7051 struct perf_output_handle handle
;
7052 struct perf_sample_data sample
;
7053 struct perf_aux_event
{
7054 struct perf_event_header header
;
7060 .type
= PERF_RECORD_AUX
,
7062 .size
= sizeof(rec
),
7070 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7071 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7076 perf_output_put(&handle
, rec
);
7077 perf_event__output_id_sample(event
, &handle
, &sample
);
7079 perf_output_end(&handle
);
7083 * Lost/dropped samples logging
7085 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7087 struct perf_output_handle handle
;
7088 struct perf_sample_data sample
;
7092 struct perf_event_header header
;
7094 } lost_samples_event
= {
7096 .type
= PERF_RECORD_LOST_SAMPLES
,
7098 .size
= sizeof(lost_samples_event
),
7103 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7105 ret
= perf_output_begin(&handle
, event
,
7106 lost_samples_event
.header
.size
);
7110 perf_output_put(&handle
, lost_samples_event
);
7111 perf_event__output_id_sample(event
, &handle
, &sample
);
7112 perf_output_end(&handle
);
7116 * context_switch tracking
7119 struct perf_switch_event
{
7120 struct task_struct
*task
;
7121 struct task_struct
*next_prev
;
7124 struct perf_event_header header
;
7130 static int perf_event_switch_match(struct perf_event
*event
)
7132 return event
->attr
.context_switch
;
7135 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7137 struct perf_switch_event
*se
= data
;
7138 struct perf_output_handle handle
;
7139 struct perf_sample_data sample
;
7142 if (!perf_event_switch_match(event
))
7145 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7146 if (event
->ctx
->task
) {
7147 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7148 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7150 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7151 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7152 se
->event_id
.next_prev_pid
=
7153 perf_event_pid(event
, se
->next_prev
);
7154 se
->event_id
.next_prev_tid
=
7155 perf_event_tid(event
, se
->next_prev
);
7158 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7160 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7164 if (event
->ctx
->task
)
7165 perf_output_put(&handle
, se
->event_id
.header
);
7167 perf_output_put(&handle
, se
->event_id
);
7169 perf_event__output_id_sample(event
, &handle
, &sample
);
7171 perf_output_end(&handle
);
7174 static void perf_event_switch(struct task_struct
*task
,
7175 struct task_struct
*next_prev
, bool sched_in
)
7177 struct perf_switch_event switch_event
;
7179 /* N.B. caller checks nr_switch_events != 0 */
7181 switch_event
= (struct perf_switch_event
){
7183 .next_prev
= next_prev
,
7187 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7190 /* .next_prev_pid */
7191 /* .next_prev_tid */
7195 perf_iterate_sb(perf_event_switch_output
,
7201 * IRQ throttle logging
7204 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7206 struct perf_output_handle handle
;
7207 struct perf_sample_data sample
;
7211 struct perf_event_header header
;
7215 } throttle_event
= {
7217 .type
= PERF_RECORD_THROTTLE
,
7219 .size
= sizeof(throttle_event
),
7221 .time
= perf_event_clock(event
),
7222 .id
= primary_event_id(event
),
7223 .stream_id
= event
->id
,
7227 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7229 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7231 ret
= perf_output_begin(&handle
, event
,
7232 throttle_event
.header
.size
);
7236 perf_output_put(&handle
, throttle_event
);
7237 perf_event__output_id_sample(event
, &handle
, &sample
);
7238 perf_output_end(&handle
);
7241 static void perf_log_itrace_start(struct perf_event
*event
)
7243 struct perf_output_handle handle
;
7244 struct perf_sample_data sample
;
7245 struct perf_aux_event
{
7246 struct perf_event_header header
;
7253 event
= event
->parent
;
7255 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7256 event
->hw
.itrace_started
)
7259 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7260 rec
.header
.misc
= 0;
7261 rec
.header
.size
= sizeof(rec
);
7262 rec
.pid
= perf_event_pid(event
, current
);
7263 rec
.tid
= perf_event_tid(event
, current
);
7265 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7266 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7271 perf_output_put(&handle
, rec
);
7272 perf_event__output_id_sample(event
, &handle
, &sample
);
7274 perf_output_end(&handle
);
7278 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7280 struct hw_perf_event
*hwc
= &event
->hw
;
7284 seq
= __this_cpu_read(perf_throttled_seq
);
7285 if (seq
!= hwc
->interrupts_seq
) {
7286 hwc
->interrupts_seq
= seq
;
7287 hwc
->interrupts
= 1;
7290 if (unlikely(throttle
7291 && hwc
->interrupts
>= max_samples_per_tick
)) {
7292 __this_cpu_inc(perf_throttled_count
);
7293 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7294 hwc
->interrupts
= MAX_INTERRUPTS
;
7295 perf_log_throttle(event
, 0);
7300 if (event
->attr
.freq
) {
7301 u64 now
= perf_clock();
7302 s64 delta
= now
- hwc
->freq_time_stamp
;
7304 hwc
->freq_time_stamp
= now
;
7306 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7307 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7313 int perf_event_account_interrupt(struct perf_event
*event
)
7315 return __perf_event_account_interrupt(event
, 1);
7318 static bool sample_is_allowed(struct perf_event
*event
, struct pt_regs
*regs
)
7321 * Due to interrupt latency (AKA "skid"), we may enter the
7322 * kernel before taking an overflow, even if the PMU is only
7323 * counting user events.
7324 * To avoid leaking information to userspace, we must always
7325 * reject kernel samples when exclude_kernel is set.
7327 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7334 * Generic event overflow handling, sampling.
7337 static int __perf_event_overflow(struct perf_event
*event
,
7338 int throttle
, struct perf_sample_data
*data
,
7339 struct pt_regs
*regs
)
7341 int events
= atomic_read(&event
->event_limit
);
7345 * Non-sampling counters might still use the PMI to fold short
7346 * hardware counters, ignore those.
7348 if (unlikely(!is_sampling_event(event
)))
7351 ret
= __perf_event_account_interrupt(event
, throttle
);
7354 * For security, drop the skid kernel samples if necessary.
7356 if (!sample_is_allowed(event
, regs
))
7360 * XXX event_limit might not quite work as expected on inherited
7364 event
->pending_kill
= POLL_IN
;
7365 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7367 event
->pending_kill
= POLL_HUP
;
7369 perf_event_disable_inatomic(event
);
7372 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7374 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7375 event
->pending_wakeup
= 1;
7376 irq_work_queue(&event
->pending
);
7382 int perf_event_overflow(struct perf_event
*event
,
7383 struct perf_sample_data
*data
,
7384 struct pt_regs
*regs
)
7386 return __perf_event_overflow(event
, 1, data
, regs
);
7390 * Generic software event infrastructure
7393 struct swevent_htable
{
7394 struct swevent_hlist
*swevent_hlist
;
7395 struct mutex hlist_mutex
;
7398 /* Recursion avoidance in each contexts */
7399 int recursion
[PERF_NR_CONTEXTS
];
7402 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7405 * We directly increment event->count and keep a second value in
7406 * event->hw.period_left to count intervals. This period event
7407 * is kept in the range [-sample_period, 0] so that we can use the
7411 u64
perf_swevent_set_period(struct perf_event
*event
)
7413 struct hw_perf_event
*hwc
= &event
->hw
;
7414 u64 period
= hwc
->last_period
;
7418 hwc
->last_period
= hwc
->sample_period
;
7421 old
= val
= local64_read(&hwc
->period_left
);
7425 nr
= div64_u64(period
+ val
, period
);
7426 offset
= nr
* period
;
7428 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7434 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7435 struct perf_sample_data
*data
,
7436 struct pt_regs
*regs
)
7438 struct hw_perf_event
*hwc
= &event
->hw
;
7442 overflow
= perf_swevent_set_period(event
);
7444 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7447 for (; overflow
; overflow
--) {
7448 if (__perf_event_overflow(event
, throttle
,
7451 * We inhibit the overflow from happening when
7452 * hwc->interrupts == MAX_INTERRUPTS.
7460 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7461 struct perf_sample_data
*data
,
7462 struct pt_regs
*regs
)
7464 struct hw_perf_event
*hwc
= &event
->hw
;
7466 local64_add(nr
, &event
->count
);
7471 if (!is_sampling_event(event
))
7474 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7476 return perf_swevent_overflow(event
, 1, data
, regs
);
7478 data
->period
= event
->hw
.last_period
;
7480 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7481 return perf_swevent_overflow(event
, 1, data
, regs
);
7483 if (local64_add_negative(nr
, &hwc
->period_left
))
7486 perf_swevent_overflow(event
, 0, data
, regs
);
7489 static int perf_exclude_event(struct perf_event
*event
,
7490 struct pt_regs
*regs
)
7492 if (event
->hw
.state
& PERF_HES_STOPPED
)
7496 if (event
->attr
.exclude_user
&& user_mode(regs
))
7499 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7506 static int perf_swevent_match(struct perf_event
*event
,
7507 enum perf_type_id type
,
7509 struct perf_sample_data
*data
,
7510 struct pt_regs
*regs
)
7512 if (event
->attr
.type
!= type
)
7515 if (event
->attr
.config
!= event_id
)
7518 if (perf_exclude_event(event
, regs
))
7524 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7526 u64 val
= event_id
| (type
<< 32);
7528 return hash_64(val
, SWEVENT_HLIST_BITS
);
7531 static inline struct hlist_head
*
7532 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7534 u64 hash
= swevent_hash(type
, event_id
);
7536 return &hlist
->heads
[hash
];
7539 /* For the read side: events when they trigger */
7540 static inline struct hlist_head
*
7541 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7543 struct swevent_hlist
*hlist
;
7545 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7549 return __find_swevent_head(hlist
, type
, event_id
);
7552 /* For the event head insertion and removal in the hlist */
7553 static inline struct hlist_head
*
7554 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7556 struct swevent_hlist
*hlist
;
7557 u32 event_id
= event
->attr
.config
;
7558 u64 type
= event
->attr
.type
;
7561 * Event scheduling is always serialized against hlist allocation
7562 * and release. Which makes the protected version suitable here.
7563 * The context lock guarantees that.
7565 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7566 lockdep_is_held(&event
->ctx
->lock
));
7570 return __find_swevent_head(hlist
, type
, event_id
);
7573 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7575 struct perf_sample_data
*data
,
7576 struct pt_regs
*regs
)
7578 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7579 struct perf_event
*event
;
7580 struct hlist_head
*head
;
7583 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7587 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7588 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7589 perf_swevent_event(event
, nr
, data
, regs
);
7595 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7597 int perf_swevent_get_recursion_context(void)
7599 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7601 return get_recursion_context(swhash
->recursion
);
7603 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7605 void perf_swevent_put_recursion_context(int rctx
)
7607 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7609 put_recursion_context(swhash
->recursion
, rctx
);
7612 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7614 struct perf_sample_data data
;
7616 if (WARN_ON_ONCE(!regs
))
7619 perf_sample_data_init(&data
, addr
, 0);
7620 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7623 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7627 preempt_disable_notrace();
7628 rctx
= perf_swevent_get_recursion_context();
7629 if (unlikely(rctx
< 0))
7632 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7634 perf_swevent_put_recursion_context(rctx
);
7636 preempt_enable_notrace();
7639 static void perf_swevent_read(struct perf_event
*event
)
7643 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7645 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7646 struct hw_perf_event
*hwc
= &event
->hw
;
7647 struct hlist_head
*head
;
7649 if (is_sampling_event(event
)) {
7650 hwc
->last_period
= hwc
->sample_period
;
7651 perf_swevent_set_period(event
);
7654 hwc
->state
= !(flags
& PERF_EF_START
);
7656 head
= find_swevent_head(swhash
, event
);
7657 if (WARN_ON_ONCE(!head
))
7660 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7661 perf_event_update_userpage(event
);
7666 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7668 hlist_del_rcu(&event
->hlist_entry
);
7671 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7673 event
->hw
.state
= 0;
7676 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7678 event
->hw
.state
= PERF_HES_STOPPED
;
7681 /* Deref the hlist from the update side */
7682 static inline struct swevent_hlist
*
7683 swevent_hlist_deref(struct swevent_htable
*swhash
)
7685 return rcu_dereference_protected(swhash
->swevent_hlist
,
7686 lockdep_is_held(&swhash
->hlist_mutex
));
7689 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7691 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7696 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7697 kfree_rcu(hlist
, rcu_head
);
7700 static void swevent_hlist_put_cpu(int cpu
)
7702 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7704 mutex_lock(&swhash
->hlist_mutex
);
7706 if (!--swhash
->hlist_refcount
)
7707 swevent_hlist_release(swhash
);
7709 mutex_unlock(&swhash
->hlist_mutex
);
7712 static void swevent_hlist_put(void)
7716 for_each_possible_cpu(cpu
)
7717 swevent_hlist_put_cpu(cpu
);
7720 static int swevent_hlist_get_cpu(int cpu
)
7722 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7725 mutex_lock(&swhash
->hlist_mutex
);
7726 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7727 struct swevent_hlist
*hlist
;
7729 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7734 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7736 swhash
->hlist_refcount
++;
7738 mutex_unlock(&swhash
->hlist_mutex
);
7743 static int swevent_hlist_get(void)
7745 int err
, cpu
, failed_cpu
;
7748 for_each_possible_cpu(cpu
) {
7749 err
= swevent_hlist_get_cpu(cpu
);
7759 for_each_possible_cpu(cpu
) {
7760 if (cpu
== failed_cpu
)
7762 swevent_hlist_put_cpu(cpu
);
7769 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7771 static void sw_perf_event_destroy(struct perf_event
*event
)
7773 u64 event_id
= event
->attr
.config
;
7775 WARN_ON(event
->parent
);
7777 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7778 swevent_hlist_put();
7781 static int perf_swevent_init(struct perf_event
*event
)
7783 u64 event_id
= event
->attr
.config
;
7785 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7789 * no branch sampling for software events
7791 if (has_branch_stack(event
))
7795 case PERF_COUNT_SW_CPU_CLOCK
:
7796 case PERF_COUNT_SW_TASK_CLOCK
:
7803 if (event_id
>= PERF_COUNT_SW_MAX
)
7806 if (!event
->parent
) {
7809 err
= swevent_hlist_get();
7813 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7814 event
->destroy
= sw_perf_event_destroy
;
7820 static struct pmu perf_swevent
= {
7821 .task_ctx_nr
= perf_sw_context
,
7823 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7825 .event_init
= perf_swevent_init
,
7826 .add
= perf_swevent_add
,
7827 .del
= perf_swevent_del
,
7828 .start
= perf_swevent_start
,
7829 .stop
= perf_swevent_stop
,
7830 .read
= perf_swevent_read
,
7833 #ifdef CONFIG_EVENT_TRACING
7835 static int perf_tp_filter_match(struct perf_event
*event
,
7836 struct perf_sample_data
*data
)
7838 void *record
= data
->raw
->frag
.data
;
7840 /* only top level events have filters set */
7842 event
= event
->parent
;
7844 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7849 static int perf_tp_event_match(struct perf_event
*event
,
7850 struct perf_sample_data
*data
,
7851 struct pt_regs
*regs
)
7853 if (event
->hw
.state
& PERF_HES_STOPPED
)
7856 * All tracepoints are from kernel-space.
7858 if (event
->attr
.exclude_kernel
)
7861 if (!perf_tp_filter_match(event
, data
))
7867 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7868 struct trace_event_call
*call
, u64 count
,
7869 struct pt_regs
*regs
, struct hlist_head
*head
,
7870 struct task_struct
*task
)
7872 struct bpf_prog
*prog
= call
->prog
;
7875 *(struct pt_regs
**)raw_data
= regs
;
7876 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7877 perf_swevent_put_recursion_context(rctx
);
7881 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7884 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7886 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7887 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7888 struct task_struct
*task
)
7890 struct perf_sample_data data
;
7891 struct perf_event
*event
;
7893 struct perf_raw_record raw
= {
7900 perf_sample_data_init(&data
, 0, 0);
7903 perf_trace_buf_update(record
, event_type
);
7905 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7906 if (perf_tp_event_match(event
, &data
, regs
))
7907 perf_swevent_event(event
, count
, &data
, regs
);
7911 * If we got specified a target task, also iterate its context and
7912 * deliver this event there too.
7914 if (task
&& task
!= current
) {
7915 struct perf_event_context
*ctx
;
7916 struct trace_entry
*entry
= record
;
7919 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7923 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7924 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7926 if (event
->attr
.config
!= entry
->type
)
7928 if (perf_tp_event_match(event
, &data
, regs
))
7929 perf_swevent_event(event
, count
, &data
, regs
);
7935 perf_swevent_put_recursion_context(rctx
);
7937 EXPORT_SYMBOL_GPL(perf_tp_event
);
7939 static void tp_perf_event_destroy(struct perf_event
*event
)
7941 perf_trace_destroy(event
);
7944 static int perf_tp_event_init(struct perf_event
*event
)
7948 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7952 * no branch sampling for tracepoint events
7954 if (has_branch_stack(event
))
7957 err
= perf_trace_init(event
);
7961 event
->destroy
= tp_perf_event_destroy
;
7966 static struct pmu perf_tracepoint
= {
7967 .task_ctx_nr
= perf_sw_context
,
7969 .event_init
= perf_tp_event_init
,
7970 .add
= perf_trace_add
,
7971 .del
= perf_trace_del
,
7972 .start
= perf_swevent_start
,
7973 .stop
= perf_swevent_stop
,
7974 .read
= perf_swevent_read
,
7977 static inline void perf_tp_register(void)
7979 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7982 static void perf_event_free_filter(struct perf_event
*event
)
7984 ftrace_profile_free_filter(event
);
7987 #ifdef CONFIG_BPF_SYSCALL
7988 static void bpf_overflow_handler(struct perf_event
*event
,
7989 struct perf_sample_data
*data
,
7990 struct pt_regs
*regs
)
7992 struct bpf_perf_event_data_kern ctx
= {
7999 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8002 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8005 __this_cpu_dec(bpf_prog_active
);
8010 event
->orig_overflow_handler(event
, data
, regs
);
8013 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8015 struct bpf_prog
*prog
;
8017 if (event
->overflow_handler_context
)
8018 /* hw breakpoint or kernel counter */
8024 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8026 return PTR_ERR(prog
);
8029 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8030 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8034 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8036 struct bpf_prog
*prog
= event
->prog
;
8041 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8046 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8050 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8055 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8057 bool is_kprobe
, is_tracepoint
;
8058 struct bpf_prog
*prog
;
8060 if (event
->attr
.type
== PERF_TYPE_HARDWARE
||
8061 event
->attr
.type
== PERF_TYPE_SOFTWARE
)
8062 return perf_event_set_bpf_handler(event
, prog_fd
);
8064 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8067 if (event
->tp_event
->prog
)
8070 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8071 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8072 if (!is_kprobe
&& !is_tracepoint
)
8073 /* bpf programs can only be attached to u/kprobe or tracepoint */
8076 prog
= bpf_prog_get(prog_fd
);
8078 return PTR_ERR(prog
);
8080 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8081 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8082 /* valid fd, but invalid bpf program type */
8087 if (is_tracepoint
) {
8088 int off
= trace_event_get_offsets(event
->tp_event
);
8090 if (prog
->aux
->max_ctx_offset
> off
) {
8095 event
->tp_event
->prog
= prog
;
8100 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8102 struct bpf_prog
*prog
;
8104 perf_event_free_bpf_handler(event
);
8106 if (!event
->tp_event
)
8109 prog
= event
->tp_event
->prog
;
8111 event
->tp_event
->prog
= NULL
;
8118 static inline void perf_tp_register(void)
8122 static void perf_event_free_filter(struct perf_event
*event
)
8126 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8131 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8134 #endif /* CONFIG_EVENT_TRACING */
8136 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8137 void perf_bp_event(struct perf_event
*bp
, void *data
)
8139 struct perf_sample_data sample
;
8140 struct pt_regs
*regs
= data
;
8142 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8144 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8145 perf_swevent_event(bp
, 1, &sample
, regs
);
8150 * Allocate a new address filter
8152 static struct perf_addr_filter
*
8153 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8155 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8156 struct perf_addr_filter
*filter
;
8158 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8162 INIT_LIST_HEAD(&filter
->entry
);
8163 list_add_tail(&filter
->entry
, filters
);
8168 static void free_filters_list(struct list_head
*filters
)
8170 struct perf_addr_filter
*filter
, *iter
;
8172 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8174 iput(filter
->inode
);
8175 list_del(&filter
->entry
);
8181 * Free existing address filters and optionally install new ones
8183 static void perf_addr_filters_splice(struct perf_event
*event
,
8184 struct list_head
*head
)
8186 unsigned long flags
;
8189 if (!has_addr_filter(event
))
8192 /* don't bother with children, they don't have their own filters */
8196 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8198 list_splice_init(&event
->addr_filters
.list
, &list
);
8200 list_splice(head
, &event
->addr_filters
.list
);
8202 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8204 free_filters_list(&list
);
8208 * Scan through mm's vmas and see if one of them matches the
8209 * @filter; if so, adjust filter's address range.
8210 * Called with mm::mmap_sem down for reading.
8212 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8213 struct mm_struct
*mm
)
8215 struct vm_area_struct
*vma
;
8217 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8218 struct file
*file
= vma
->vm_file
;
8219 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8220 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8225 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8228 return vma
->vm_start
;
8235 * Update event's address range filters based on the
8236 * task's existing mappings, if any.
8238 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8240 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8241 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8242 struct perf_addr_filter
*filter
;
8243 struct mm_struct
*mm
= NULL
;
8244 unsigned int count
= 0;
8245 unsigned long flags
;
8248 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8249 * will stop on the parent's child_mutex that our caller is also holding
8251 if (task
== TASK_TOMBSTONE
)
8254 if (!ifh
->nr_file_filters
)
8257 mm
= get_task_mm(event
->ctx
->task
);
8261 down_read(&mm
->mmap_sem
);
8263 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8264 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8265 event
->addr_filters_offs
[count
] = 0;
8268 * Adjust base offset if the filter is associated to a binary
8269 * that needs to be mapped:
8272 event
->addr_filters_offs
[count
] =
8273 perf_addr_filter_apply(filter
, mm
);
8278 event
->addr_filters_gen
++;
8279 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8281 up_read(&mm
->mmap_sem
);
8286 perf_event_stop(event
, 1);
8290 * Address range filtering: limiting the data to certain
8291 * instruction address ranges. Filters are ioctl()ed to us from
8292 * userspace as ascii strings.
8294 * Filter string format:
8297 * where ACTION is one of the
8298 * * "filter": limit the trace to this region
8299 * * "start": start tracing from this address
8300 * * "stop": stop tracing at this address/region;
8302 * * for kernel addresses: <start address>[/<size>]
8303 * * for object files: <start address>[/<size>]@</path/to/object/file>
8305 * if <size> is not specified, the range is treated as a single address.
8319 IF_STATE_ACTION
= 0,
8324 static const match_table_t if_tokens
= {
8325 { IF_ACT_FILTER
, "filter" },
8326 { IF_ACT_START
, "start" },
8327 { IF_ACT_STOP
, "stop" },
8328 { IF_SRC_FILE
, "%u/%u@%s" },
8329 { IF_SRC_KERNEL
, "%u/%u" },
8330 { IF_SRC_FILEADDR
, "%u@%s" },
8331 { IF_SRC_KERNELADDR
, "%u" },
8332 { IF_ACT_NONE
, NULL
},
8336 * Address filter string parser
8339 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8340 struct list_head
*filters
)
8342 struct perf_addr_filter
*filter
= NULL
;
8343 char *start
, *orig
, *filename
= NULL
;
8345 substring_t args
[MAX_OPT_ARGS
];
8346 int state
= IF_STATE_ACTION
, token
;
8347 unsigned int kernel
= 0;
8350 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8354 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8360 /* filter definition begins */
8361 if (state
== IF_STATE_ACTION
) {
8362 filter
= perf_addr_filter_new(event
, filters
);
8367 token
= match_token(start
, if_tokens
, args
);
8374 if (state
!= IF_STATE_ACTION
)
8377 state
= IF_STATE_SOURCE
;
8380 case IF_SRC_KERNELADDR
:
8384 case IF_SRC_FILEADDR
:
8386 if (state
!= IF_STATE_SOURCE
)
8389 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8393 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8397 if (filter
->range
) {
8399 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8404 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8405 int fpos
= filter
->range
? 2 : 1;
8407 filename
= match_strdup(&args
[fpos
]);
8414 state
= IF_STATE_END
;
8422 * Filter definition is fully parsed, validate and install it.
8423 * Make sure that it doesn't contradict itself or the event's
8426 if (state
== IF_STATE_END
) {
8428 if (kernel
&& event
->attr
.exclude_kernel
)
8436 * For now, we only support file-based filters
8437 * in per-task events; doing so for CPU-wide
8438 * events requires additional context switching
8439 * trickery, since same object code will be
8440 * mapped at different virtual addresses in
8441 * different processes.
8444 if (!event
->ctx
->task
)
8445 goto fail_free_name
;
8447 /* look up the path and grab its inode */
8448 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8450 goto fail_free_name
;
8452 filter
->inode
= igrab(d_inode(path
.dentry
));
8458 if (!filter
->inode
||
8459 !S_ISREG(filter
->inode
->i_mode
))
8460 /* free_filters_list() will iput() */
8463 event
->addr_filters
.nr_file_filters
++;
8466 /* ready to consume more filters */
8467 state
= IF_STATE_ACTION
;
8472 if (state
!= IF_STATE_ACTION
)
8482 free_filters_list(filters
);
8489 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8495 * Since this is called in perf_ioctl() path, we're already holding
8498 lockdep_assert_held(&event
->ctx
->mutex
);
8500 if (WARN_ON_ONCE(event
->parent
))
8503 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8505 goto fail_clear_files
;
8507 ret
= event
->pmu
->addr_filters_validate(&filters
);
8509 goto fail_free_filters
;
8511 /* remove existing filters, if any */
8512 perf_addr_filters_splice(event
, &filters
);
8514 /* install new filters */
8515 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8520 free_filters_list(&filters
);
8523 event
->addr_filters
.nr_file_filters
= 0;
8528 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8533 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8534 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8535 !has_addr_filter(event
))
8538 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8539 if (IS_ERR(filter_str
))
8540 return PTR_ERR(filter_str
);
8542 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8543 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8544 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8546 else if (has_addr_filter(event
))
8547 ret
= perf_event_set_addr_filter(event
, filter_str
);
8554 * hrtimer based swevent callback
8557 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8559 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8560 struct perf_sample_data data
;
8561 struct pt_regs
*regs
;
8562 struct perf_event
*event
;
8565 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8567 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8568 return HRTIMER_NORESTART
;
8570 event
->pmu
->read(event
);
8572 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8573 regs
= get_irq_regs();
8575 if (regs
&& !perf_exclude_event(event
, regs
)) {
8576 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8577 if (__perf_event_overflow(event
, 1, &data
, regs
))
8578 ret
= HRTIMER_NORESTART
;
8581 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8582 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8587 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8589 struct hw_perf_event
*hwc
= &event
->hw
;
8592 if (!is_sampling_event(event
))
8595 period
= local64_read(&hwc
->period_left
);
8600 local64_set(&hwc
->period_left
, 0);
8602 period
= max_t(u64
, 10000, hwc
->sample_period
);
8604 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8605 HRTIMER_MODE_REL_PINNED
);
8608 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8610 struct hw_perf_event
*hwc
= &event
->hw
;
8612 if (is_sampling_event(event
)) {
8613 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8614 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8616 hrtimer_cancel(&hwc
->hrtimer
);
8620 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8622 struct hw_perf_event
*hwc
= &event
->hw
;
8624 if (!is_sampling_event(event
))
8627 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8628 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8631 * Since hrtimers have a fixed rate, we can do a static freq->period
8632 * mapping and avoid the whole period adjust feedback stuff.
8634 if (event
->attr
.freq
) {
8635 long freq
= event
->attr
.sample_freq
;
8637 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8638 hwc
->sample_period
= event
->attr
.sample_period
;
8639 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8640 hwc
->last_period
= hwc
->sample_period
;
8641 event
->attr
.freq
= 0;
8646 * Software event: cpu wall time clock
8649 static void cpu_clock_event_update(struct perf_event
*event
)
8654 now
= local_clock();
8655 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8656 local64_add(now
- prev
, &event
->count
);
8659 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8661 local64_set(&event
->hw
.prev_count
, local_clock());
8662 perf_swevent_start_hrtimer(event
);
8665 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8667 perf_swevent_cancel_hrtimer(event
);
8668 cpu_clock_event_update(event
);
8671 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8673 if (flags
& PERF_EF_START
)
8674 cpu_clock_event_start(event
, flags
);
8675 perf_event_update_userpage(event
);
8680 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8682 cpu_clock_event_stop(event
, flags
);
8685 static void cpu_clock_event_read(struct perf_event
*event
)
8687 cpu_clock_event_update(event
);
8690 static int cpu_clock_event_init(struct perf_event
*event
)
8692 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8695 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8699 * no branch sampling for software events
8701 if (has_branch_stack(event
))
8704 perf_swevent_init_hrtimer(event
);
8709 static struct pmu perf_cpu_clock
= {
8710 .task_ctx_nr
= perf_sw_context
,
8712 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8714 .event_init
= cpu_clock_event_init
,
8715 .add
= cpu_clock_event_add
,
8716 .del
= cpu_clock_event_del
,
8717 .start
= cpu_clock_event_start
,
8718 .stop
= cpu_clock_event_stop
,
8719 .read
= cpu_clock_event_read
,
8723 * Software event: task time clock
8726 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8731 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8733 local64_add(delta
, &event
->count
);
8736 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8738 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8739 perf_swevent_start_hrtimer(event
);
8742 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8744 perf_swevent_cancel_hrtimer(event
);
8745 task_clock_event_update(event
, event
->ctx
->time
);
8748 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8750 if (flags
& PERF_EF_START
)
8751 task_clock_event_start(event
, flags
);
8752 perf_event_update_userpage(event
);
8757 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8759 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8762 static void task_clock_event_read(struct perf_event
*event
)
8764 u64 now
= perf_clock();
8765 u64 delta
= now
- event
->ctx
->timestamp
;
8766 u64 time
= event
->ctx
->time
+ delta
;
8768 task_clock_event_update(event
, time
);
8771 static int task_clock_event_init(struct perf_event
*event
)
8773 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8776 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8780 * no branch sampling for software events
8782 if (has_branch_stack(event
))
8785 perf_swevent_init_hrtimer(event
);
8790 static struct pmu perf_task_clock
= {
8791 .task_ctx_nr
= perf_sw_context
,
8793 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8795 .event_init
= task_clock_event_init
,
8796 .add
= task_clock_event_add
,
8797 .del
= task_clock_event_del
,
8798 .start
= task_clock_event_start
,
8799 .stop
= task_clock_event_stop
,
8800 .read
= task_clock_event_read
,
8803 static void perf_pmu_nop_void(struct pmu
*pmu
)
8807 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8811 static int perf_pmu_nop_int(struct pmu
*pmu
)
8816 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8818 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8820 __this_cpu_write(nop_txn_flags
, flags
);
8822 if (flags
& ~PERF_PMU_TXN_ADD
)
8825 perf_pmu_disable(pmu
);
8828 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8830 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8832 __this_cpu_write(nop_txn_flags
, 0);
8834 if (flags
& ~PERF_PMU_TXN_ADD
)
8837 perf_pmu_enable(pmu
);
8841 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8843 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8845 __this_cpu_write(nop_txn_flags
, 0);
8847 if (flags
& ~PERF_PMU_TXN_ADD
)
8850 perf_pmu_enable(pmu
);
8853 static int perf_event_idx_default(struct perf_event
*event
)
8859 * Ensures all contexts with the same task_ctx_nr have the same
8860 * pmu_cpu_context too.
8862 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8869 list_for_each_entry(pmu
, &pmus
, entry
) {
8870 if (pmu
->task_ctx_nr
== ctxn
)
8871 return pmu
->pmu_cpu_context
;
8877 static void free_pmu_context(struct pmu
*pmu
)
8879 mutex_lock(&pmus_lock
);
8880 free_percpu(pmu
->pmu_cpu_context
);
8881 mutex_unlock(&pmus_lock
);
8885 * Let userspace know that this PMU supports address range filtering:
8887 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8888 struct device_attribute
*attr
,
8891 struct pmu
*pmu
= dev_get_drvdata(dev
);
8893 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8895 DEVICE_ATTR_RO(nr_addr_filters
);
8897 static struct idr pmu_idr
;
8900 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8902 struct pmu
*pmu
= dev_get_drvdata(dev
);
8904 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8906 static DEVICE_ATTR_RO(type
);
8909 perf_event_mux_interval_ms_show(struct device
*dev
,
8910 struct device_attribute
*attr
,
8913 struct pmu
*pmu
= dev_get_drvdata(dev
);
8915 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8918 static DEFINE_MUTEX(mux_interval_mutex
);
8921 perf_event_mux_interval_ms_store(struct device
*dev
,
8922 struct device_attribute
*attr
,
8923 const char *buf
, size_t count
)
8925 struct pmu
*pmu
= dev_get_drvdata(dev
);
8926 int timer
, cpu
, ret
;
8928 ret
= kstrtoint(buf
, 0, &timer
);
8935 /* same value, noting to do */
8936 if (timer
== pmu
->hrtimer_interval_ms
)
8939 mutex_lock(&mux_interval_mutex
);
8940 pmu
->hrtimer_interval_ms
= timer
;
8942 /* update all cpuctx for this PMU */
8944 for_each_online_cpu(cpu
) {
8945 struct perf_cpu_context
*cpuctx
;
8946 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8947 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8949 cpu_function_call(cpu
,
8950 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8953 mutex_unlock(&mux_interval_mutex
);
8957 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8959 static struct attribute
*pmu_dev_attrs
[] = {
8960 &dev_attr_type
.attr
,
8961 &dev_attr_perf_event_mux_interval_ms
.attr
,
8964 ATTRIBUTE_GROUPS(pmu_dev
);
8966 static int pmu_bus_running
;
8967 static struct bus_type pmu_bus
= {
8968 .name
= "event_source",
8969 .dev_groups
= pmu_dev_groups
,
8972 static void pmu_dev_release(struct device
*dev
)
8977 static int pmu_dev_alloc(struct pmu
*pmu
)
8981 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8985 pmu
->dev
->groups
= pmu
->attr_groups
;
8986 device_initialize(pmu
->dev
);
8987 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8991 dev_set_drvdata(pmu
->dev
, pmu
);
8992 pmu
->dev
->bus
= &pmu_bus
;
8993 pmu
->dev
->release
= pmu_dev_release
;
8994 ret
= device_add(pmu
->dev
);
8998 /* For PMUs with address filters, throw in an extra attribute: */
8999 if (pmu
->nr_addr_filters
)
9000 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9009 device_del(pmu
->dev
);
9012 put_device(pmu
->dev
);
9016 static struct lock_class_key cpuctx_mutex
;
9017 static struct lock_class_key cpuctx_lock
;
9019 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9023 mutex_lock(&pmus_lock
);
9025 pmu
->pmu_disable_count
= alloc_percpu(int);
9026 if (!pmu
->pmu_disable_count
)
9035 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9043 if (pmu_bus_running
) {
9044 ret
= pmu_dev_alloc(pmu
);
9050 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9051 static int hw_context_taken
= 0;
9054 * Other than systems with heterogeneous CPUs, it never makes
9055 * sense for two PMUs to share perf_hw_context. PMUs which are
9056 * uncore must use perf_invalid_context.
9058 if (WARN_ON_ONCE(hw_context_taken
&&
9059 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9060 pmu
->task_ctx_nr
= perf_invalid_context
;
9062 hw_context_taken
= 1;
9065 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9066 if (pmu
->pmu_cpu_context
)
9067 goto got_cpu_context
;
9070 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9071 if (!pmu
->pmu_cpu_context
)
9074 for_each_possible_cpu(cpu
) {
9075 struct perf_cpu_context
*cpuctx
;
9077 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9078 __perf_event_init_context(&cpuctx
->ctx
);
9079 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9080 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9081 cpuctx
->ctx
.pmu
= pmu
;
9083 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9087 if (!pmu
->start_txn
) {
9088 if (pmu
->pmu_enable
) {
9090 * If we have pmu_enable/pmu_disable calls, install
9091 * transaction stubs that use that to try and batch
9092 * hardware accesses.
9094 pmu
->start_txn
= perf_pmu_start_txn
;
9095 pmu
->commit_txn
= perf_pmu_commit_txn
;
9096 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9098 pmu
->start_txn
= perf_pmu_nop_txn
;
9099 pmu
->commit_txn
= perf_pmu_nop_int
;
9100 pmu
->cancel_txn
= perf_pmu_nop_void
;
9104 if (!pmu
->pmu_enable
) {
9105 pmu
->pmu_enable
= perf_pmu_nop_void
;
9106 pmu
->pmu_disable
= perf_pmu_nop_void
;
9109 if (!pmu
->event_idx
)
9110 pmu
->event_idx
= perf_event_idx_default
;
9112 list_add_rcu(&pmu
->entry
, &pmus
);
9113 atomic_set(&pmu
->exclusive_cnt
, 0);
9116 mutex_unlock(&pmus_lock
);
9121 device_del(pmu
->dev
);
9122 put_device(pmu
->dev
);
9125 if (pmu
->type
>= PERF_TYPE_MAX
)
9126 idr_remove(&pmu_idr
, pmu
->type
);
9129 free_percpu(pmu
->pmu_disable_count
);
9132 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9134 void perf_pmu_unregister(struct pmu
*pmu
)
9138 mutex_lock(&pmus_lock
);
9139 remove_device
= pmu_bus_running
;
9140 list_del_rcu(&pmu
->entry
);
9141 mutex_unlock(&pmus_lock
);
9144 * We dereference the pmu list under both SRCU and regular RCU, so
9145 * synchronize against both of those.
9147 synchronize_srcu(&pmus_srcu
);
9150 free_percpu(pmu
->pmu_disable_count
);
9151 if (pmu
->type
>= PERF_TYPE_MAX
)
9152 idr_remove(&pmu_idr
, pmu
->type
);
9153 if (remove_device
) {
9154 if (pmu
->nr_addr_filters
)
9155 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9156 device_del(pmu
->dev
);
9157 put_device(pmu
->dev
);
9159 free_pmu_context(pmu
);
9161 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9163 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9165 struct perf_event_context
*ctx
= NULL
;
9168 if (!try_module_get(pmu
->module
))
9171 if (event
->group_leader
!= event
) {
9173 * This ctx->mutex can nest when we're called through
9174 * inheritance. See the perf_event_ctx_lock_nested() comment.
9176 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9177 SINGLE_DEPTH_NESTING
);
9182 ret
= pmu
->event_init(event
);
9185 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9188 module_put(pmu
->module
);
9193 static struct pmu
*perf_init_event(struct perf_event
*event
)
9199 idx
= srcu_read_lock(&pmus_srcu
);
9201 /* Try parent's PMU first: */
9202 if (event
->parent
&& event
->parent
->pmu
) {
9203 pmu
= event
->parent
->pmu
;
9204 ret
= perf_try_init_event(pmu
, event
);
9210 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9213 ret
= perf_try_init_event(pmu
, event
);
9219 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9220 ret
= perf_try_init_event(pmu
, event
);
9224 if (ret
!= -ENOENT
) {
9229 pmu
= ERR_PTR(-ENOENT
);
9231 srcu_read_unlock(&pmus_srcu
, idx
);
9236 static void attach_sb_event(struct perf_event
*event
)
9238 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9240 raw_spin_lock(&pel
->lock
);
9241 list_add_rcu(&event
->sb_list
, &pel
->list
);
9242 raw_spin_unlock(&pel
->lock
);
9246 * We keep a list of all !task (and therefore per-cpu) events
9247 * that need to receive side-band records.
9249 * This avoids having to scan all the various PMU per-cpu contexts
9252 static void account_pmu_sb_event(struct perf_event
*event
)
9254 if (is_sb_event(event
))
9255 attach_sb_event(event
);
9258 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9263 if (is_cgroup_event(event
))
9264 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9267 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9268 static void account_freq_event_nohz(void)
9270 #ifdef CONFIG_NO_HZ_FULL
9271 /* Lock so we don't race with concurrent unaccount */
9272 spin_lock(&nr_freq_lock
);
9273 if (atomic_inc_return(&nr_freq_events
) == 1)
9274 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9275 spin_unlock(&nr_freq_lock
);
9279 static void account_freq_event(void)
9281 if (tick_nohz_full_enabled())
9282 account_freq_event_nohz();
9284 atomic_inc(&nr_freq_events
);
9288 static void account_event(struct perf_event
*event
)
9295 if (event
->attach_state
& PERF_ATTACH_TASK
)
9297 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9298 atomic_inc(&nr_mmap_events
);
9299 if (event
->attr
.comm
)
9300 atomic_inc(&nr_comm_events
);
9301 if (event
->attr
.namespaces
)
9302 atomic_inc(&nr_namespaces_events
);
9303 if (event
->attr
.task
)
9304 atomic_inc(&nr_task_events
);
9305 if (event
->attr
.freq
)
9306 account_freq_event();
9307 if (event
->attr
.context_switch
) {
9308 atomic_inc(&nr_switch_events
);
9311 if (has_branch_stack(event
))
9313 if (is_cgroup_event(event
))
9317 if (atomic_inc_not_zero(&perf_sched_count
))
9320 mutex_lock(&perf_sched_mutex
);
9321 if (!atomic_read(&perf_sched_count
)) {
9322 static_branch_enable(&perf_sched_events
);
9324 * Guarantee that all CPUs observe they key change and
9325 * call the perf scheduling hooks before proceeding to
9326 * install events that need them.
9328 synchronize_sched();
9331 * Now that we have waited for the sync_sched(), allow further
9332 * increments to by-pass the mutex.
9334 atomic_inc(&perf_sched_count
);
9335 mutex_unlock(&perf_sched_mutex
);
9339 account_event_cpu(event
, event
->cpu
);
9341 account_pmu_sb_event(event
);
9345 * Allocate and initialize a event structure
9347 static struct perf_event
*
9348 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9349 struct task_struct
*task
,
9350 struct perf_event
*group_leader
,
9351 struct perf_event
*parent_event
,
9352 perf_overflow_handler_t overflow_handler
,
9353 void *context
, int cgroup_fd
)
9356 struct perf_event
*event
;
9357 struct hw_perf_event
*hwc
;
9360 if ((unsigned)cpu
>= nr_cpu_ids
) {
9361 if (!task
|| cpu
!= -1)
9362 return ERR_PTR(-EINVAL
);
9365 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9367 return ERR_PTR(-ENOMEM
);
9370 * Single events are their own group leaders, with an
9371 * empty sibling list:
9374 group_leader
= event
;
9376 mutex_init(&event
->child_mutex
);
9377 INIT_LIST_HEAD(&event
->child_list
);
9379 INIT_LIST_HEAD(&event
->group_entry
);
9380 INIT_LIST_HEAD(&event
->event_entry
);
9381 INIT_LIST_HEAD(&event
->sibling_list
);
9382 INIT_LIST_HEAD(&event
->rb_entry
);
9383 INIT_LIST_HEAD(&event
->active_entry
);
9384 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9385 INIT_HLIST_NODE(&event
->hlist_entry
);
9388 init_waitqueue_head(&event
->waitq
);
9389 init_irq_work(&event
->pending
, perf_pending_event
);
9391 mutex_init(&event
->mmap_mutex
);
9392 raw_spin_lock_init(&event
->addr_filters
.lock
);
9394 atomic_long_set(&event
->refcount
, 1);
9396 event
->attr
= *attr
;
9397 event
->group_leader
= group_leader
;
9401 event
->parent
= parent_event
;
9403 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9404 event
->id
= atomic64_inc_return(&perf_event_id
);
9406 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9409 event
->attach_state
= PERF_ATTACH_TASK
;
9411 * XXX pmu::event_init needs to know what task to account to
9412 * and we cannot use the ctx information because we need the
9413 * pmu before we get a ctx.
9415 event
->hw
.target
= task
;
9418 event
->clock
= &local_clock
;
9420 event
->clock
= parent_event
->clock
;
9422 if (!overflow_handler
&& parent_event
) {
9423 overflow_handler
= parent_event
->overflow_handler
;
9424 context
= parent_event
->overflow_handler_context
;
9425 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9426 if (overflow_handler
== bpf_overflow_handler
) {
9427 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9430 err
= PTR_ERR(prog
);
9434 event
->orig_overflow_handler
=
9435 parent_event
->orig_overflow_handler
;
9440 if (overflow_handler
) {
9441 event
->overflow_handler
= overflow_handler
;
9442 event
->overflow_handler_context
= context
;
9443 } else if (is_write_backward(event
)){
9444 event
->overflow_handler
= perf_event_output_backward
;
9445 event
->overflow_handler_context
= NULL
;
9447 event
->overflow_handler
= perf_event_output_forward
;
9448 event
->overflow_handler_context
= NULL
;
9451 perf_event__state_init(event
);
9456 hwc
->sample_period
= attr
->sample_period
;
9457 if (attr
->freq
&& attr
->sample_freq
)
9458 hwc
->sample_period
= 1;
9459 hwc
->last_period
= hwc
->sample_period
;
9461 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9464 * We currently do not support PERF_SAMPLE_READ on inherited events.
9465 * See perf_output_read().
9467 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9470 if (!has_branch_stack(event
))
9471 event
->attr
.branch_sample_type
= 0;
9473 if (cgroup_fd
!= -1) {
9474 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9479 pmu
= perf_init_event(event
);
9485 err
= exclusive_event_init(event
);
9489 if (has_addr_filter(event
)) {
9490 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9491 sizeof(unsigned long),
9493 if (!event
->addr_filters_offs
) {
9498 /* force hw sync on the address filters */
9499 event
->addr_filters_gen
= 1;
9502 if (!event
->parent
) {
9503 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9504 err
= get_callchain_buffers(attr
->sample_max_stack
);
9506 goto err_addr_filters
;
9510 /* symmetric to unaccount_event() in _free_event() */
9511 account_event(event
);
9516 kfree(event
->addr_filters_offs
);
9519 exclusive_event_destroy(event
);
9523 event
->destroy(event
);
9524 module_put(pmu
->module
);
9526 if (is_cgroup_event(event
))
9527 perf_detach_cgroup(event
);
9529 put_pid_ns(event
->ns
);
9532 return ERR_PTR(err
);
9535 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9536 struct perf_event_attr
*attr
)
9541 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9545 * zero the full structure, so that a short copy will be nice.
9547 memset(attr
, 0, sizeof(*attr
));
9549 ret
= get_user(size
, &uattr
->size
);
9553 if (size
> PAGE_SIZE
) /* silly large */
9556 if (!size
) /* abi compat */
9557 size
= PERF_ATTR_SIZE_VER0
;
9559 if (size
< PERF_ATTR_SIZE_VER0
)
9563 * If we're handed a bigger struct than we know of,
9564 * ensure all the unknown bits are 0 - i.e. new
9565 * user-space does not rely on any kernel feature
9566 * extensions we dont know about yet.
9568 if (size
> sizeof(*attr
)) {
9569 unsigned char __user
*addr
;
9570 unsigned char __user
*end
;
9573 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9574 end
= (void __user
*)uattr
+ size
;
9576 for (; addr
< end
; addr
++) {
9577 ret
= get_user(val
, addr
);
9583 size
= sizeof(*attr
);
9586 ret
= copy_from_user(attr
, uattr
, size
);
9590 if (attr
->__reserved_1
)
9593 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9596 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9599 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9600 u64 mask
= attr
->branch_sample_type
;
9602 /* only using defined bits */
9603 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9606 /* at least one branch bit must be set */
9607 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9610 /* propagate priv level, when not set for branch */
9611 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9613 /* exclude_kernel checked on syscall entry */
9614 if (!attr
->exclude_kernel
)
9615 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9617 if (!attr
->exclude_user
)
9618 mask
|= PERF_SAMPLE_BRANCH_USER
;
9620 if (!attr
->exclude_hv
)
9621 mask
|= PERF_SAMPLE_BRANCH_HV
;
9623 * adjust user setting (for HW filter setup)
9625 attr
->branch_sample_type
= mask
;
9627 /* privileged levels capture (kernel, hv): check permissions */
9628 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9629 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9633 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9634 ret
= perf_reg_validate(attr
->sample_regs_user
);
9639 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9640 if (!arch_perf_have_user_stack_dump())
9644 * We have __u32 type for the size, but so far
9645 * we can only use __u16 as maximum due to the
9646 * __u16 sample size limit.
9648 if (attr
->sample_stack_user
>= USHRT_MAX
)
9650 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9654 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9655 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9660 put_user(sizeof(*attr
), &uattr
->size
);
9666 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9668 struct ring_buffer
*rb
= NULL
;
9674 /* don't allow circular references */
9675 if (event
== output_event
)
9679 * Don't allow cross-cpu buffers
9681 if (output_event
->cpu
!= event
->cpu
)
9685 * If its not a per-cpu rb, it must be the same task.
9687 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9691 * Mixing clocks in the same buffer is trouble you don't need.
9693 if (output_event
->clock
!= event
->clock
)
9697 * Either writing ring buffer from beginning or from end.
9698 * Mixing is not allowed.
9700 if (is_write_backward(output_event
) != is_write_backward(event
))
9704 * If both events generate aux data, they must be on the same PMU
9706 if (has_aux(event
) && has_aux(output_event
) &&
9707 event
->pmu
!= output_event
->pmu
)
9711 mutex_lock(&event
->mmap_mutex
);
9712 /* Can't redirect output if we've got an active mmap() */
9713 if (atomic_read(&event
->mmap_count
))
9717 /* get the rb we want to redirect to */
9718 rb
= ring_buffer_get(output_event
);
9723 ring_buffer_attach(event
, rb
);
9727 mutex_unlock(&event
->mmap_mutex
);
9733 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9739 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9742 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9744 bool nmi_safe
= false;
9747 case CLOCK_MONOTONIC
:
9748 event
->clock
= &ktime_get_mono_fast_ns
;
9752 case CLOCK_MONOTONIC_RAW
:
9753 event
->clock
= &ktime_get_raw_fast_ns
;
9757 case CLOCK_REALTIME
:
9758 event
->clock
= &ktime_get_real_ns
;
9761 case CLOCK_BOOTTIME
:
9762 event
->clock
= &ktime_get_boot_ns
;
9766 event
->clock
= &ktime_get_tai_ns
;
9773 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9780 * Variation on perf_event_ctx_lock_nested(), except we take two context
9783 static struct perf_event_context
*
9784 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9785 struct perf_event_context
*ctx
)
9787 struct perf_event_context
*gctx
;
9791 gctx
= READ_ONCE(group_leader
->ctx
);
9792 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9798 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9800 if (group_leader
->ctx
!= gctx
) {
9801 mutex_unlock(&ctx
->mutex
);
9802 mutex_unlock(&gctx
->mutex
);
9811 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9813 * @attr_uptr: event_id type attributes for monitoring/sampling
9816 * @group_fd: group leader event fd
9818 SYSCALL_DEFINE5(perf_event_open
,
9819 struct perf_event_attr __user
*, attr_uptr
,
9820 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9822 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9823 struct perf_event
*event
, *sibling
;
9824 struct perf_event_attr attr
;
9825 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9826 struct file
*event_file
= NULL
;
9827 struct fd group
= {NULL
, 0};
9828 struct task_struct
*task
= NULL
;
9833 int f_flags
= O_RDWR
;
9836 /* for future expandability... */
9837 if (flags
& ~PERF_FLAG_ALL
)
9840 err
= perf_copy_attr(attr_uptr
, &attr
);
9844 if (!attr
.exclude_kernel
) {
9845 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9849 if (attr
.namespaces
) {
9850 if (!capable(CAP_SYS_ADMIN
))
9855 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9858 if (attr
.sample_period
& (1ULL << 63))
9862 if (!attr
.sample_max_stack
)
9863 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9866 * In cgroup mode, the pid argument is used to pass the fd
9867 * opened to the cgroup directory in cgroupfs. The cpu argument
9868 * designates the cpu on which to monitor threads from that
9871 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9874 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9875 f_flags
|= O_CLOEXEC
;
9877 event_fd
= get_unused_fd_flags(f_flags
);
9881 if (group_fd
!= -1) {
9882 err
= perf_fget_light(group_fd
, &group
);
9885 group_leader
= group
.file
->private_data
;
9886 if (flags
& PERF_FLAG_FD_OUTPUT
)
9887 output_event
= group_leader
;
9888 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9889 group_leader
= NULL
;
9892 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9893 task
= find_lively_task_by_vpid(pid
);
9895 err
= PTR_ERR(task
);
9900 if (task
&& group_leader
&&
9901 group_leader
->attr
.inherit
!= attr
.inherit
) {
9909 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9914 * Reuse ptrace permission checks for now.
9916 * We must hold cred_guard_mutex across this and any potential
9917 * perf_install_in_context() call for this new event to
9918 * serialize against exec() altering our credentials (and the
9919 * perf_event_exit_task() that could imply).
9922 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9926 if (flags
& PERF_FLAG_PID_CGROUP
)
9929 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9930 NULL
, NULL
, cgroup_fd
);
9931 if (IS_ERR(event
)) {
9932 err
= PTR_ERR(event
);
9936 if (is_sampling_event(event
)) {
9937 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9944 * Special case software events and allow them to be part of
9945 * any hardware group.
9949 if (attr
.use_clockid
) {
9950 err
= perf_event_set_clock(event
, attr
.clockid
);
9955 if (pmu
->task_ctx_nr
== perf_sw_context
)
9956 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9959 (is_software_event(event
) != is_software_event(group_leader
))) {
9960 if (is_software_event(event
)) {
9962 * If event and group_leader are not both a software
9963 * event, and event is, then group leader is not.
9965 * Allow the addition of software events to !software
9966 * groups, this is safe because software events never
9969 pmu
= group_leader
->pmu
;
9970 } else if (is_software_event(group_leader
) &&
9971 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9973 * In case the group is a pure software group, and we
9974 * try to add a hardware event, move the whole group to
9975 * the hardware context.
9982 * Get the target context (task or percpu):
9984 ctx
= find_get_context(pmu
, task
, event
);
9990 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9996 * Look up the group leader (we will attach this event to it):
10002 * Do not allow a recursive hierarchy (this new sibling
10003 * becoming part of another group-sibling):
10005 if (group_leader
->group_leader
!= group_leader
)
10008 /* All events in a group should have the same clock */
10009 if (group_leader
->clock
!= event
->clock
)
10013 * Do not allow to attach to a group in a different
10014 * task or CPU context:
10018 * Make sure we're both on the same task, or both
10021 if (group_leader
->ctx
->task
!= ctx
->task
)
10025 * Make sure we're both events for the same CPU;
10026 * grouping events for different CPUs is broken; since
10027 * you can never concurrently schedule them anyhow.
10029 if (group_leader
->cpu
!= event
->cpu
)
10032 if (group_leader
->ctx
!= ctx
)
10037 * Only a group leader can be exclusive or pinned
10039 if (attr
.exclusive
|| attr
.pinned
)
10043 if (output_event
) {
10044 err
= perf_event_set_output(event
, output_event
);
10049 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10051 if (IS_ERR(event_file
)) {
10052 err
= PTR_ERR(event_file
);
10058 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10060 if (gctx
->task
== TASK_TOMBSTONE
) {
10066 * Check if we raced against another sys_perf_event_open() call
10067 * moving the software group underneath us.
10069 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10071 * If someone moved the group out from under us, check
10072 * if this new event wound up on the same ctx, if so
10073 * its the regular !move_group case, otherwise fail.
10079 perf_event_ctx_unlock(group_leader
, gctx
);
10084 mutex_lock(&ctx
->mutex
);
10087 if (ctx
->task
== TASK_TOMBSTONE
) {
10092 if (!perf_event_validate_size(event
)) {
10098 * Must be under the same ctx::mutex as perf_install_in_context(),
10099 * because we need to serialize with concurrent event creation.
10101 if (!exclusive_event_installable(event
, ctx
)) {
10102 /* exclusive and group stuff are assumed mutually exclusive */
10103 WARN_ON_ONCE(move_group
);
10109 WARN_ON_ONCE(ctx
->parent_ctx
);
10112 * This is the point on no return; we cannot fail hereafter. This is
10113 * where we start modifying current state.
10118 * See perf_event_ctx_lock() for comments on the details
10119 * of swizzling perf_event::ctx.
10121 perf_remove_from_context(group_leader
, 0);
10124 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10126 perf_remove_from_context(sibling
, 0);
10131 * Wait for everybody to stop referencing the events through
10132 * the old lists, before installing it on new lists.
10137 * Install the group siblings before the group leader.
10139 * Because a group leader will try and install the entire group
10140 * (through the sibling list, which is still in-tact), we can
10141 * end up with siblings installed in the wrong context.
10143 * By installing siblings first we NO-OP because they're not
10144 * reachable through the group lists.
10146 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10148 perf_event__state_init(sibling
);
10149 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10154 * Removing from the context ends up with disabled
10155 * event. What we want here is event in the initial
10156 * startup state, ready to be add into new context.
10158 perf_event__state_init(group_leader
);
10159 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10164 * Precalculate sample_data sizes; do while holding ctx::mutex such
10165 * that we're serialized against further additions and before
10166 * perf_install_in_context() which is the point the event is active and
10167 * can use these values.
10169 perf_event__header_size(event
);
10170 perf_event__id_header_size(event
);
10172 event
->owner
= current
;
10174 perf_install_in_context(ctx
, event
, event
->cpu
);
10175 perf_unpin_context(ctx
);
10178 perf_event_ctx_unlock(group_leader
, gctx
);
10179 mutex_unlock(&ctx
->mutex
);
10182 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10183 put_task_struct(task
);
10188 mutex_lock(¤t
->perf_event_mutex
);
10189 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10190 mutex_unlock(¤t
->perf_event_mutex
);
10193 * Drop the reference on the group_event after placing the
10194 * new event on the sibling_list. This ensures destruction
10195 * of the group leader will find the pointer to itself in
10196 * perf_group_detach().
10199 fd_install(event_fd
, event_file
);
10204 perf_event_ctx_unlock(group_leader
, gctx
);
10205 mutex_unlock(&ctx
->mutex
);
10209 perf_unpin_context(ctx
);
10213 * If event_file is set, the fput() above will have called ->release()
10214 * and that will take care of freeing the event.
10220 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10225 put_task_struct(task
);
10229 put_unused_fd(event_fd
);
10234 * perf_event_create_kernel_counter
10236 * @attr: attributes of the counter to create
10237 * @cpu: cpu in which the counter is bound
10238 * @task: task to profile (NULL for percpu)
10240 struct perf_event
*
10241 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10242 struct task_struct
*task
,
10243 perf_overflow_handler_t overflow_handler
,
10246 struct perf_event_context
*ctx
;
10247 struct perf_event
*event
;
10251 * Get the target context (task or percpu):
10254 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10255 overflow_handler
, context
, -1);
10256 if (IS_ERR(event
)) {
10257 err
= PTR_ERR(event
);
10261 /* Mark owner so we could distinguish it from user events. */
10262 event
->owner
= TASK_TOMBSTONE
;
10264 ctx
= find_get_context(event
->pmu
, task
, event
);
10266 err
= PTR_ERR(ctx
);
10270 WARN_ON_ONCE(ctx
->parent_ctx
);
10271 mutex_lock(&ctx
->mutex
);
10272 if (ctx
->task
== TASK_TOMBSTONE
) {
10277 if (!exclusive_event_installable(event
, ctx
)) {
10282 perf_install_in_context(ctx
, event
, cpu
);
10283 perf_unpin_context(ctx
);
10284 mutex_unlock(&ctx
->mutex
);
10289 mutex_unlock(&ctx
->mutex
);
10290 perf_unpin_context(ctx
);
10295 return ERR_PTR(err
);
10297 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10299 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10301 struct perf_event_context
*src_ctx
;
10302 struct perf_event_context
*dst_ctx
;
10303 struct perf_event
*event
, *tmp
;
10306 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10307 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10310 * See perf_event_ctx_lock() for comments on the details
10311 * of swizzling perf_event::ctx.
10313 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10314 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10316 perf_remove_from_context(event
, 0);
10317 unaccount_event_cpu(event
, src_cpu
);
10319 list_add(&event
->migrate_entry
, &events
);
10323 * Wait for the events to quiesce before re-instating them.
10328 * Re-instate events in 2 passes.
10330 * Skip over group leaders and only install siblings on this first
10331 * pass, siblings will not get enabled without a leader, however a
10332 * leader will enable its siblings, even if those are still on the old
10335 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10336 if (event
->group_leader
== event
)
10339 list_del(&event
->migrate_entry
);
10340 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10341 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10342 account_event_cpu(event
, dst_cpu
);
10343 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10348 * Once all the siblings are setup properly, install the group leaders
10351 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10352 list_del(&event
->migrate_entry
);
10353 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10354 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10355 account_event_cpu(event
, dst_cpu
);
10356 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10359 mutex_unlock(&dst_ctx
->mutex
);
10360 mutex_unlock(&src_ctx
->mutex
);
10362 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10364 static void sync_child_event(struct perf_event
*child_event
,
10365 struct task_struct
*child
)
10367 struct perf_event
*parent_event
= child_event
->parent
;
10370 if (child_event
->attr
.inherit_stat
)
10371 perf_event_read_event(child_event
, child
);
10373 child_val
= perf_event_count(child_event
);
10376 * Add back the child's count to the parent's count:
10378 atomic64_add(child_val
, &parent_event
->child_count
);
10379 atomic64_add(child_event
->total_time_enabled
,
10380 &parent_event
->child_total_time_enabled
);
10381 atomic64_add(child_event
->total_time_running
,
10382 &parent_event
->child_total_time_running
);
10386 perf_event_exit_event(struct perf_event
*child_event
,
10387 struct perf_event_context
*child_ctx
,
10388 struct task_struct
*child
)
10390 struct perf_event
*parent_event
= child_event
->parent
;
10393 * Do not destroy the 'original' grouping; because of the context
10394 * switch optimization the original events could've ended up in a
10395 * random child task.
10397 * If we were to destroy the original group, all group related
10398 * operations would cease to function properly after this random
10401 * Do destroy all inherited groups, we don't care about those
10402 * and being thorough is better.
10404 raw_spin_lock_irq(&child_ctx
->lock
);
10405 WARN_ON_ONCE(child_ctx
->is_active
);
10408 perf_group_detach(child_event
);
10409 list_del_event(child_event
, child_ctx
);
10410 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10411 raw_spin_unlock_irq(&child_ctx
->lock
);
10414 * Parent events are governed by their filedesc, retain them.
10416 if (!parent_event
) {
10417 perf_event_wakeup(child_event
);
10421 * Child events can be cleaned up.
10424 sync_child_event(child_event
, child
);
10427 * Remove this event from the parent's list
10429 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10430 mutex_lock(&parent_event
->child_mutex
);
10431 list_del_init(&child_event
->child_list
);
10432 mutex_unlock(&parent_event
->child_mutex
);
10435 * Kick perf_poll() for is_event_hup().
10437 perf_event_wakeup(parent_event
);
10438 free_event(child_event
);
10439 put_event(parent_event
);
10442 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10444 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10445 struct perf_event
*child_event
, *next
;
10447 WARN_ON_ONCE(child
!= current
);
10449 child_ctx
= perf_pin_task_context(child
, ctxn
);
10454 * In order to reduce the amount of tricky in ctx tear-down, we hold
10455 * ctx::mutex over the entire thing. This serializes against almost
10456 * everything that wants to access the ctx.
10458 * The exception is sys_perf_event_open() /
10459 * perf_event_create_kernel_count() which does find_get_context()
10460 * without ctx::mutex (it cannot because of the move_group double mutex
10461 * lock thing). See the comments in perf_install_in_context().
10463 mutex_lock(&child_ctx
->mutex
);
10466 * In a single ctx::lock section, de-schedule the events and detach the
10467 * context from the task such that we cannot ever get it scheduled back
10470 raw_spin_lock_irq(&child_ctx
->lock
);
10471 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10474 * Now that the context is inactive, destroy the task <-> ctx relation
10475 * and mark the context dead.
10477 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10478 put_ctx(child_ctx
); /* cannot be last */
10479 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10480 put_task_struct(current
); /* cannot be last */
10482 clone_ctx
= unclone_ctx(child_ctx
);
10483 raw_spin_unlock_irq(&child_ctx
->lock
);
10486 put_ctx(clone_ctx
);
10489 * Report the task dead after unscheduling the events so that we
10490 * won't get any samples after PERF_RECORD_EXIT. We can however still
10491 * get a few PERF_RECORD_READ events.
10493 perf_event_task(child
, child_ctx
, 0);
10495 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10496 perf_event_exit_event(child_event
, child_ctx
, child
);
10498 mutex_unlock(&child_ctx
->mutex
);
10500 put_ctx(child_ctx
);
10504 * When a child task exits, feed back event values to parent events.
10506 * Can be called with cred_guard_mutex held when called from
10507 * install_exec_creds().
10509 void perf_event_exit_task(struct task_struct
*child
)
10511 struct perf_event
*event
, *tmp
;
10514 mutex_lock(&child
->perf_event_mutex
);
10515 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10517 list_del_init(&event
->owner_entry
);
10520 * Ensure the list deletion is visible before we clear
10521 * the owner, closes a race against perf_release() where
10522 * we need to serialize on the owner->perf_event_mutex.
10524 smp_store_release(&event
->owner
, NULL
);
10526 mutex_unlock(&child
->perf_event_mutex
);
10528 for_each_task_context_nr(ctxn
)
10529 perf_event_exit_task_context(child
, ctxn
);
10532 * The perf_event_exit_task_context calls perf_event_task
10533 * with child's task_ctx, which generates EXIT events for
10534 * child contexts and sets child->perf_event_ctxp[] to NULL.
10535 * At this point we need to send EXIT events to cpu contexts.
10537 perf_event_task(child
, NULL
, 0);
10540 static void perf_free_event(struct perf_event
*event
,
10541 struct perf_event_context
*ctx
)
10543 struct perf_event
*parent
= event
->parent
;
10545 if (WARN_ON_ONCE(!parent
))
10548 mutex_lock(&parent
->child_mutex
);
10549 list_del_init(&event
->child_list
);
10550 mutex_unlock(&parent
->child_mutex
);
10554 raw_spin_lock_irq(&ctx
->lock
);
10555 perf_group_detach(event
);
10556 list_del_event(event
, ctx
);
10557 raw_spin_unlock_irq(&ctx
->lock
);
10562 * Free an unexposed, unused context as created by inheritance by
10563 * perf_event_init_task below, used by fork() in case of fail.
10565 * Not all locks are strictly required, but take them anyway to be nice and
10566 * help out with the lockdep assertions.
10568 void perf_event_free_task(struct task_struct
*task
)
10570 struct perf_event_context
*ctx
;
10571 struct perf_event
*event
, *tmp
;
10574 for_each_task_context_nr(ctxn
) {
10575 ctx
= task
->perf_event_ctxp
[ctxn
];
10579 mutex_lock(&ctx
->mutex
);
10580 raw_spin_lock_irq(&ctx
->lock
);
10582 * Destroy the task <-> ctx relation and mark the context dead.
10584 * This is important because even though the task hasn't been
10585 * exposed yet the context has been (through child_list).
10587 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10588 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10589 put_task_struct(task
); /* cannot be last */
10590 raw_spin_unlock_irq(&ctx
->lock
);
10592 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10593 perf_free_event(event
, ctx
);
10595 mutex_unlock(&ctx
->mutex
);
10600 void perf_event_delayed_put(struct task_struct
*task
)
10604 for_each_task_context_nr(ctxn
)
10605 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10608 struct file
*perf_event_get(unsigned int fd
)
10612 file
= fget_raw(fd
);
10614 return ERR_PTR(-EBADF
);
10616 if (file
->f_op
!= &perf_fops
) {
10618 return ERR_PTR(-EBADF
);
10624 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10627 return ERR_PTR(-EINVAL
);
10629 return &event
->attr
;
10633 * Inherit a event from parent task to child task.
10636 * - valid pointer on success
10637 * - NULL for orphaned events
10638 * - IS_ERR() on error
10640 static struct perf_event
*
10641 inherit_event(struct perf_event
*parent_event
,
10642 struct task_struct
*parent
,
10643 struct perf_event_context
*parent_ctx
,
10644 struct task_struct
*child
,
10645 struct perf_event
*group_leader
,
10646 struct perf_event_context
*child_ctx
)
10648 enum perf_event_active_state parent_state
= parent_event
->state
;
10649 struct perf_event
*child_event
;
10650 unsigned long flags
;
10653 * Instead of creating recursive hierarchies of events,
10654 * we link inherited events back to the original parent,
10655 * which has a filp for sure, which we use as the reference
10658 if (parent_event
->parent
)
10659 parent_event
= parent_event
->parent
;
10661 child_event
= perf_event_alloc(&parent_event
->attr
,
10664 group_leader
, parent_event
,
10666 if (IS_ERR(child_event
))
10667 return child_event
;
10670 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10671 * must be under the same lock in order to serialize against
10672 * perf_event_release_kernel(), such that either we must observe
10673 * is_orphaned_event() or they will observe us on the child_list.
10675 mutex_lock(&parent_event
->child_mutex
);
10676 if (is_orphaned_event(parent_event
) ||
10677 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10678 mutex_unlock(&parent_event
->child_mutex
);
10679 free_event(child_event
);
10683 get_ctx(child_ctx
);
10686 * Make the child state follow the state of the parent event,
10687 * not its attr.disabled bit. We hold the parent's mutex,
10688 * so we won't race with perf_event_{en, dis}able_family.
10690 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10691 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10693 child_event
->state
= PERF_EVENT_STATE_OFF
;
10695 if (parent_event
->attr
.freq
) {
10696 u64 sample_period
= parent_event
->hw
.sample_period
;
10697 struct hw_perf_event
*hwc
= &child_event
->hw
;
10699 hwc
->sample_period
= sample_period
;
10700 hwc
->last_period
= sample_period
;
10702 local64_set(&hwc
->period_left
, sample_period
);
10705 child_event
->ctx
= child_ctx
;
10706 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10707 child_event
->overflow_handler_context
10708 = parent_event
->overflow_handler_context
;
10711 * Precalculate sample_data sizes
10713 perf_event__header_size(child_event
);
10714 perf_event__id_header_size(child_event
);
10717 * Link it up in the child's context:
10719 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10720 add_event_to_ctx(child_event
, child_ctx
);
10721 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10724 * Link this into the parent event's child list
10726 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10727 mutex_unlock(&parent_event
->child_mutex
);
10729 return child_event
;
10733 * Inherits an event group.
10735 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10736 * This matches with perf_event_release_kernel() removing all child events.
10742 static int inherit_group(struct perf_event
*parent_event
,
10743 struct task_struct
*parent
,
10744 struct perf_event_context
*parent_ctx
,
10745 struct task_struct
*child
,
10746 struct perf_event_context
*child_ctx
)
10748 struct perf_event
*leader
;
10749 struct perf_event
*sub
;
10750 struct perf_event
*child_ctr
;
10752 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10753 child
, NULL
, child_ctx
);
10754 if (IS_ERR(leader
))
10755 return PTR_ERR(leader
);
10757 * @leader can be NULL here because of is_orphaned_event(). In this
10758 * case inherit_event() will create individual events, similar to what
10759 * perf_group_detach() would do anyway.
10761 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10762 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10763 child
, leader
, child_ctx
);
10764 if (IS_ERR(child_ctr
))
10765 return PTR_ERR(child_ctr
);
10771 * Creates the child task context and tries to inherit the event-group.
10773 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10774 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10775 * consistent with perf_event_release_kernel() removing all child events.
10782 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10783 struct perf_event_context
*parent_ctx
,
10784 struct task_struct
*child
, int ctxn
,
10785 int *inherited_all
)
10788 struct perf_event_context
*child_ctx
;
10790 if (!event
->attr
.inherit
) {
10791 *inherited_all
= 0;
10795 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10798 * This is executed from the parent task context, so
10799 * inherit events that have been marked for cloning.
10800 * First allocate and initialize a context for the
10803 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10807 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10810 ret
= inherit_group(event
, parent
, parent_ctx
,
10814 *inherited_all
= 0;
10820 * Initialize the perf_event context in task_struct
10822 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10824 struct perf_event_context
*child_ctx
, *parent_ctx
;
10825 struct perf_event_context
*cloned_ctx
;
10826 struct perf_event
*event
;
10827 struct task_struct
*parent
= current
;
10828 int inherited_all
= 1;
10829 unsigned long flags
;
10832 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10836 * If the parent's context is a clone, pin it so it won't get
10837 * swapped under us.
10839 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10844 * No need to check if parent_ctx != NULL here; since we saw
10845 * it non-NULL earlier, the only reason for it to become NULL
10846 * is if we exit, and since we're currently in the middle of
10847 * a fork we can't be exiting at the same time.
10851 * Lock the parent list. No need to lock the child - not PID
10852 * hashed yet and not running, so nobody can access it.
10854 mutex_lock(&parent_ctx
->mutex
);
10857 * We dont have to disable NMIs - we are only looking at
10858 * the list, not manipulating it:
10860 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10861 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10862 child
, ctxn
, &inherited_all
);
10868 * We can't hold ctx->lock when iterating the ->flexible_group list due
10869 * to allocations, but we need to prevent rotation because
10870 * rotate_ctx() will change the list from interrupt context.
10872 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10873 parent_ctx
->rotate_disable
= 1;
10874 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10876 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10877 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10878 child
, ctxn
, &inherited_all
);
10883 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10884 parent_ctx
->rotate_disable
= 0;
10886 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10888 if (child_ctx
&& inherited_all
) {
10890 * Mark the child context as a clone of the parent
10891 * context, or of whatever the parent is a clone of.
10893 * Note that if the parent is a clone, the holding of
10894 * parent_ctx->lock avoids it from being uncloned.
10896 cloned_ctx
= parent_ctx
->parent_ctx
;
10898 child_ctx
->parent_ctx
= cloned_ctx
;
10899 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10901 child_ctx
->parent_ctx
= parent_ctx
;
10902 child_ctx
->parent_gen
= parent_ctx
->generation
;
10904 get_ctx(child_ctx
->parent_ctx
);
10907 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10909 mutex_unlock(&parent_ctx
->mutex
);
10911 perf_unpin_context(parent_ctx
);
10912 put_ctx(parent_ctx
);
10918 * Initialize the perf_event context in task_struct
10920 int perf_event_init_task(struct task_struct
*child
)
10924 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10925 mutex_init(&child
->perf_event_mutex
);
10926 INIT_LIST_HEAD(&child
->perf_event_list
);
10928 for_each_task_context_nr(ctxn
) {
10929 ret
= perf_event_init_context(child
, ctxn
);
10931 perf_event_free_task(child
);
10939 static void __init
perf_event_init_all_cpus(void)
10941 struct swevent_htable
*swhash
;
10944 for_each_possible_cpu(cpu
) {
10945 swhash
= &per_cpu(swevent_htable
, cpu
);
10946 mutex_init(&swhash
->hlist_mutex
);
10947 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10949 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10950 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10952 #ifdef CONFIG_CGROUP_PERF
10953 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
10955 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10959 int perf_event_init_cpu(unsigned int cpu
)
10961 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10963 mutex_lock(&swhash
->hlist_mutex
);
10964 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10965 struct swevent_hlist
*hlist
;
10967 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10969 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10971 mutex_unlock(&swhash
->hlist_mutex
);
10975 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10976 static void __perf_event_exit_context(void *__info
)
10978 struct perf_event_context
*ctx
= __info
;
10979 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10980 struct perf_event
*event
;
10982 raw_spin_lock(&ctx
->lock
);
10983 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10984 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10985 raw_spin_unlock(&ctx
->lock
);
10988 static void perf_event_exit_cpu_context(int cpu
)
10990 struct perf_event_context
*ctx
;
10994 idx
= srcu_read_lock(&pmus_srcu
);
10995 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10996 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10998 mutex_lock(&ctx
->mutex
);
10999 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11000 mutex_unlock(&ctx
->mutex
);
11002 srcu_read_unlock(&pmus_srcu
, idx
);
11006 static void perf_event_exit_cpu_context(int cpu
) { }
11010 int perf_event_exit_cpu(unsigned int cpu
)
11012 perf_event_exit_cpu_context(cpu
);
11017 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11021 for_each_online_cpu(cpu
)
11022 perf_event_exit_cpu(cpu
);
11028 * Run the perf reboot notifier at the very last possible moment so that
11029 * the generic watchdog code runs as long as possible.
11031 static struct notifier_block perf_reboot_notifier
= {
11032 .notifier_call
= perf_reboot
,
11033 .priority
= INT_MIN
,
11036 void __init
perf_event_init(void)
11040 idr_init(&pmu_idr
);
11042 perf_event_init_all_cpus();
11043 init_srcu_struct(&pmus_srcu
);
11044 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11045 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11046 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11047 perf_tp_register();
11048 perf_event_init_cpu(smp_processor_id());
11049 register_reboot_notifier(&perf_reboot_notifier
);
11051 ret
= init_hw_breakpoint();
11052 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11055 * Build time assertion that we keep the data_head at the intended
11056 * location. IOW, validation we got the __reserved[] size right.
11058 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11062 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11065 struct perf_pmu_events_attr
*pmu_attr
=
11066 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11068 if (pmu_attr
->event_str
)
11069 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11073 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11075 static int __init
perf_event_sysfs_init(void)
11080 mutex_lock(&pmus_lock
);
11082 ret
= bus_register(&pmu_bus
);
11086 list_for_each_entry(pmu
, &pmus
, entry
) {
11087 if (!pmu
->name
|| pmu
->type
< 0)
11090 ret
= pmu_dev_alloc(pmu
);
11091 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11093 pmu_bus_running
= 1;
11097 mutex_unlock(&pmus_lock
);
11101 device_initcall(perf_event_sysfs_init
);
11103 #ifdef CONFIG_CGROUP_PERF
11104 static struct cgroup_subsys_state
*
11105 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11107 struct perf_cgroup
*jc
;
11109 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11111 return ERR_PTR(-ENOMEM
);
11113 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11116 return ERR_PTR(-ENOMEM
);
11122 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11124 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11126 free_percpu(jc
->info
);
11130 static int __perf_cgroup_move(void *info
)
11132 struct task_struct
*task
= info
;
11134 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11139 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11141 struct task_struct
*task
;
11142 struct cgroup_subsys_state
*css
;
11144 cgroup_taskset_for_each(task
, css
, tset
)
11145 task_function_call(task
, __perf_cgroup_move
, task
);
11148 struct cgroup_subsys perf_event_cgrp_subsys
= {
11149 .css_alloc
= perf_cgroup_css_alloc
,
11150 .css_free
= perf_cgroup_css_free
,
11151 .attach
= perf_cgroup_attach
,
11153 * Implicitly enable on dfl hierarchy so that perf events can
11154 * always be filtered by cgroup2 path as long as perf_event
11155 * controller is not mounted on a legacy hierarchy.
11157 .implicit_on_dfl
= true,
11159 #endif /* CONFIG_CGROUP_PERF */