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
;
392 static cpumask_var_t perf_online_mask
;
395 * perf event paranoia level:
396 * -1 - not paranoid at all
397 * 0 - disallow raw tracepoint access for unpriv
398 * 1 - disallow cpu events for unpriv
399 * 2 - disallow kernel profiling for unpriv
401 int sysctl_perf_event_paranoid __read_mostly
= 2;
403 /* Minimum for 512 kiB + 1 user control page */
404 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
407 * max perf event sample rate
409 #define DEFAULT_MAX_SAMPLE_RATE 100000
410 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
411 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
413 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
415 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
416 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
418 static int perf_sample_allowed_ns __read_mostly
=
419 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
421 static void update_perf_cpu_limits(void)
423 u64 tmp
= perf_sample_period_ns
;
425 tmp
*= sysctl_perf_cpu_time_max_percent
;
426 tmp
= div_u64(tmp
, 100);
430 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
433 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
435 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
436 void __user
*buffer
, size_t *lenp
,
439 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
445 * If throttling is disabled don't allow the write:
447 if (sysctl_perf_cpu_time_max_percent
== 100 ||
448 sysctl_perf_cpu_time_max_percent
== 0)
451 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
452 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
453 update_perf_cpu_limits();
458 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
460 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
461 void __user
*buffer
, size_t *lenp
,
464 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
469 if (sysctl_perf_cpu_time_max_percent
== 100 ||
470 sysctl_perf_cpu_time_max_percent
== 0) {
472 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
473 WRITE_ONCE(perf_sample_allowed_ns
, 0);
475 update_perf_cpu_limits();
482 * perf samples are done in some very critical code paths (NMIs).
483 * If they take too much CPU time, the system can lock up and not
484 * get any real work done. This will drop the sample rate when
485 * we detect that events are taking too long.
487 #define NR_ACCUMULATED_SAMPLES 128
488 static DEFINE_PER_CPU(u64
, running_sample_length
);
490 static u64 __report_avg
;
491 static u64 __report_allowed
;
493 static void perf_duration_warn(struct irq_work
*w
)
495 printk_ratelimited(KERN_INFO
496 "perf: interrupt took too long (%lld > %lld), lowering "
497 "kernel.perf_event_max_sample_rate to %d\n",
498 __report_avg
, __report_allowed
,
499 sysctl_perf_event_sample_rate
);
502 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
504 void perf_sample_event_took(u64 sample_len_ns
)
506 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
514 /* Decay the counter by 1 average sample. */
515 running_len
= __this_cpu_read(running_sample_length
);
516 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
517 running_len
+= sample_len_ns
;
518 __this_cpu_write(running_sample_length
, running_len
);
521 * Note: this will be biased artifically low until we have
522 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
523 * from having to maintain a count.
525 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
526 if (avg_len
<= max_len
)
529 __report_avg
= avg_len
;
530 __report_allowed
= max_len
;
533 * Compute a throttle threshold 25% below the current duration.
535 avg_len
+= avg_len
/ 4;
536 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
542 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
543 WRITE_ONCE(max_samples_per_tick
, max
);
545 sysctl_perf_event_sample_rate
= max
* HZ
;
546 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
548 if (!irq_work_queue(&perf_duration_work
)) {
549 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
550 "kernel.perf_event_max_sample_rate to %d\n",
551 __report_avg
, __report_allowed
,
552 sysctl_perf_event_sample_rate
);
556 static atomic64_t perf_event_id
;
558 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
559 enum event_type_t event_type
);
561 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
562 enum event_type_t event_type
,
563 struct task_struct
*task
);
565 static void update_context_time(struct perf_event_context
*ctx
);
566 static u64
perf_event_time(struct perf_event
*event
);
568 void __weak
perf_event_print_debug(void) { }
570 extern __weak
const char *perf_pmu_name(void)
575 static inline u64
perf_clock(void)
577 return local_clock();
580 static inline u64
perf_event_clock(struct perf_event
*event
)
582 return event
->clock();
585 #ifdef CONFIG_CGROUP_PERF
588 perf_cgroup_match(struct perf_event
*event
)
590 struct perf_event_context
*ctx
= event
->ctx
;
591 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
593 /* @event doesn't care about cgroup */
597 /* wants specific cgroup scope but @cpuctx isn't associated with any */
602 * Cgroup scoping is recursive. An event enabled for a cgroup is
603 * also enabled for all its descendant cgroups. If @cpuctx's
604 * cgroup is a descendant of @event's (the test covers identity
605 * case), it's a match.
607 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
608 event
->cgrp
->css
.cgroup
);
611 static inline void perf_detach_cgroup(struct perf_event
*event
)
613 css_put(&event
->cgrp
->css
);
617 static inline int is_cgroup_event(struct perf_event
*event
)
619 return event
->cgrp
!= NULL
;
622 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
624 struct perf_cgroup_info
*t
;
626 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
630 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
632 struct perf_cgroup_info
*info
;
637 info
= this_cpu_ptr(cgrp
->info
);
639 info
->time
+= now
- info
->timestamp
;
640 info
->timestamp
= now
;
643 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
645 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
647 __update_cgrp_time(cgrp_out
);
650 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
652 struct perf_cgroup
*cgrp
;
655 * ensure we access cgroup data only when needed and
656 * when we know the cgroup is pinned (css_get)
658 if (!is_cgroup_event(event
))
661 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
663 * Do not update time when cgroup is not active
665 if (cgrp
== event
->cgrp
)
666 __update_cgrp_time(event
->cgrp
);
670 perf_cgroup_set_timestamp(struct task_struct
*task
,
671 struct perf_event_context
*ctx
)
673 struct perf_cgroup
*cgrp
;
674 struct perf_cgroup_info
*info
;
677 * ctx->lock held by caller
678 * ensure we do not access cgroup data
679 * unless we have the cgroup pinned (css_get)
681 if (!task
|| !ctx
->nr_cgroups
)
684 cgrp
= perf_cgroup_from_task(task
, ctx
);
685 info
= this_cpu_ptr(cgrp
->info
);
686 info
->timestamp
= ctx
->timestamp
;
689 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
691 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
692 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
695 * reschedule events based on the cgroup constraint of task.
697 * mode SWOUT : schedule out everything
698 * mode SWIN : schedule in based on cgroup for next
700 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
702 struct perf_cpu_context
*cpuctx
;
703 struct list_head
*list
;
707 * Disable interrupts and preemption to avoid this CPU's
708 * cgrp_cpuctx_entry to change under us.
710 local_irq_save(flags
);
712 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
713 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
714 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
716 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
717 perf_pmu_disable(cpuctx
->ctx
.pmu
);
719 if (mode
& PERF_CGROUP_SWOUT
) {
720 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
722 * must not be done before ctxswout due
723 * to event_filter_match() in event_sched_out()
728 if (mode
& PERF_CGROUP_SWIN
) {
729 WARN_ON_ONCE(cpuctx
->cgrp
);
731 * set cgrp before ctxsw in to allow
732 * event_filter_match() to not have to pass
734 * we pass the cpuctx->ctx to perf_cgroup_from_task()
735 * because cgorup events are only per-cpu
737 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
739 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
741 perf_pmu_enable(cpuctx
->ctx
.pmu
);
742 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
745 local_irq_restore(flags
);
748 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
749 struct task_struct
*next
)
751 struct perf_cgroup
*cgrp1
;
752 struct perf_cgroup
*cgrp2
= NULL
;
756 * we come here when we know perf_cgroup_events > 0
757 * we do not need to pass the ctx here because we know
758 * we are holding the rcu lock
760 cgrp1
= perf_cgroup_from_task(task
, NULL
);
761 cgrp2
= perf_cgroup_from_task(next
, NULL
);
764 * only schedule out current cgroup events if we know
765 * that we are switching to a different cgroup. Otherwise,
766 * do no touch the cgroup events.
769 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
774 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
775 struct task_struct
*task
)
777 struct perf_cgroup
*cgrp1
;
778 struct perf_cgroup
*cgrp2
= NULL
;
782 * we come here when we know perf_cgroup_events > 0
783 * we do not need to pass the ctx here because we know
784 * we are holding the rcu lock
786 cgrp1
= perf_cgroup_from_task(task
, NULL
);
787 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
790 * only need to schedule in cgroup events if we are changing
791 * cgroup during ctxsw. Cgroup events were not scheduled
792 * out of ctxsw out if that was not the case.
795 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
800 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
801 struct perf_event_attr
*attr
,
802 struct perf_event
*group_leader
)
804 struct perf_cgroup
*cgrp
;
805 struct cgroup_subsys_state
*css
;
806 struct fd f
= fdget(fd
);
812 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
813 &perf_event_cgrp_subsys
);
819 cgrp
= container_of(css
, struct perf_cgroup
, css
);
823 * all events in a group must monitor
824 * the same cgroup because a task belongs
825 * to only one perf cgroup at a time
827 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
828 perf_detach_cgroup(event
);
837 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
839 struct perf_cgroup_info
*t
;
840 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
841 event
->shadow_ctx_time
= now
- t
->timestamp
;
845 perf_cgroup_defer_enabled(struct perf_event
*event
)
848 * when the current task's perf cgroup does not match
849 * the event's, we need to remember to call the
850 * perf_mark_enable() function the first time a task with
851 * a matching perf cgroup is scheduled in.
853 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
854 event
->cgrp_defer_enabled
= 1;
858 perf_cgroup_mark_enabled(struct perf_event
*event
,
859 struct perf_event_context
*ctx
)
861 struct perf_event
*sub
;
862 u64 tstamp
= perf_event_time(event
);
864 if (!event
->cgrp_defer_enabled
)
867 event
->cgrp_defer_enabled
= 0;
869 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
870 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
871 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
872 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
873 sub
->cgrp_defer_enabled
= 0;
879 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
880 * cleared when last cgroup event is removed.
883 list_update_cgroup_event(struct perf_event
*event
,
884 struct perf_event_context
*ctx
, bool add
)
886 struct perf_cpu_context
*cpuctx
;
887 struct list_head
*cpuctx_entry
;
889 if (!is_cgroup_event(event
))
892 if (add
&& ctx
->nr_cgroups
++)
894 else if (!add
&& --ctx
->nr_cgroups
)
897 * Because cgroup events are always per-cpu events,
898 * this will always be called from the right CPU.
900 cpuctx
= __get_cpu_context(ctx
);
901 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
902 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
904 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
905 if (perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
906 cpuctx
->cgrp
= event
->cgrp
;
908 list_del(cpuctx_entry
);
913 #else /* !CONFIG_CGROUP_PERF */
916 perf_cgroup_match(struct perf_event
*event
)
921 static inline void perf_detach_cgroup(struct perf_event
*event
)
924 static inline int is_cgroup_event(struct perf_event
*event
)
929 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
933 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
937 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
938 struct task_struct
*next
)
942 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
943 struct task_struct
*task
)
947 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
948 struct perf_event_attr
*attr
,
949 struct perf_event
*group_leader
)
955 perf_cgroup_set_timestamp(struct task_struct
*task
,
956 struct perf_event_context
*ctx
)
961 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
966 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
970 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
976 perf_cgroup_defer_enabled(struct perf_event
*event
)
981 perf_cgroup_mark_enabled(struct perf_event
*event
,
982 struct perf_event_context
*ctx
)
987 list_update_cgroup_event(struct perf_event
*event
,
988 struct perf_event_context
*ctx
, bool add
)
995 * set default to be dependent on timer tick just
998 #define PERF_CPU_HRTIMER (1000 / HZ)
1000 * function must be called with interrupts disabled
1002 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1004 struct perf_cpu_context
*cpuctx
;
1007 WARN_ON(!irqs_disabled());
1009 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1010 rotations
= perf_rotate_context(cpuctx
);
1012 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1014 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1016 cpuctx
->hrtimer_active
= 0;
1017 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1019 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1022 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1024 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1025 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1028 /* no multiplexing needed for SW PMU */
1029 if (pmu
->task_ctx_nr
== perf_sw_context
)
1033 * check default is sane, if not set then force to
1034 * default interval (1/tick)
1036 interval
= pmu
->hrtimer_interval_ms
;
1038 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1040 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1042 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1043 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1044 timer
->function
= perf_mux_hrtimer_handler
;
1047 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1049 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1050 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1051 unsigned long flags
;
1053 /* not for SW PMU */
1054 if (pmu
->task_ctx_nr
== perf_sw_context
)
1057 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1058 if (!cpuctx
->hrtimer_active
) {
1059 cpuctx
->hrtimer_active
= 1;
1060 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1061 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1063 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1068 void perf_pmu_disable(struct pmu
*pmu
)
1070 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1072 pmu
->pmu_disable(pmu
);
1075 void perf_pmu_enable(struct pmu
*pmu
)
1077 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1079 pmu
->pmu_enable(pmu
);
1082 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1085 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1086 * perf_event_task_tick() are fully serialized because they're strictly cpu
1087 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1088 * disabled, while perf_event_task_tick is called from IRQ context.
1090 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1092 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1094 WARN_ON(!irqs_disabled());
1096 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1098 list_add(&ctx
->active_ctx_list
, head
);
1101 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1103 WARN_ON(!irqs_disabled());
1105 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1107 list_del_init(&ctx
->active_ctx_list
);
1110 static void get_ctx(struct perf_event_context
*ctx
)
1112 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1115 static void free_ctx(struct rcu_head
*head
)
1117 struct perf_event_context
*ctx
;
1119 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1120 kfree(ctx
->task_ctx_data
);
1124 static void put_ctx(struct perf_event_context
*ctx
)
1126 if (atomic_dec_and_test(&ctx
->refcount
)) {
1127 if (ctx
->parent_ctx
)
1128 put_ctx(ctx
->parent_ctx
);
1129 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1130 put_task_struct(ctx
->task
);
1131 call_rcu(&ctx
->rcu_head
, free_ctx
);
1136 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1137 * perf_pmu_migrate_context() we need some magic.
1139 * Those places that change perf_event::ctx will hold both
1140 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1142 * Lock ordering is by mutex address. There are two other sites where
1143 * perf_event_context::mutex nests and those are:
1145 * - perf_event_exit_task_context() [ child , 0 ]
1146 * perf_event_exit_event()
1147 * put_event() [ parent, 1 ]
1149 * - perf_event_init_context() [ parent, 0 ]
1150 * inherit_task_group()
1153 * perf_event_alloc()
1155 * perf_try_init_event() [ child , 1 ]
1157 * While it appears there is an obvious deadlock here -- the parent and child
1158 * nesting levels are inverted between the two. This is in fact safe because
1159 * life-time rules separate them. That is an exiting task cannot fork, and a
1160 * spawning task cannot (yet) exit.
1162 * But remember that that these are parent<->child context relations, and
1163 * migration does not affect children, therefore these two orderings should not
1166 * The change in perf_event::ctx does not affect children (as claimed above)
1167 * because the sys_perf_event_open() case will install a new event and break
1168 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1169 * concerned with cpuctx and that doesn't have children.
1171 * The places that change perf_event::ctx will issue:
1173 * perf_remove_from_context();
1174 * synchronize_rcu();
1175 * perf_install_in_context();
1177 * to affect the change. The remove_from_context() + synchronize_rcu() should
1178 * quiesce the event, after which we can install it in the new location. This
1179 * means that only external vectors (perf_fops, prctl) can perturb the event
1180 * while in transit. Therefore all such accessors should also acquire
1181 * perf_event_context::mutex to serialize against this.
1183 * However; because event->ctx can change while we're waiting to acquire
1184 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1189 * task_struct::perf_event_mutex
1190 * perf_event_context::mutex
1191 * perf_event::child_mutex;
1192 * perf_event_context::lock
1193 * perf_event::mmap_mutex
1196 static struct perf_event_context
*
1197 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1199 struct perf_event_context
*ctx
;
1203 ctx
= ACCESS_ONCE(event
->ctx
);
1204 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1210 mutex_lock_nested(&ctx
->mutex
, nesting
);
1211 if (event
->ctx
!= ctx
) {
1212 mutex_unlock(&ctx
->mutex
);
1220 static inline struct perf_event_context
*
1221 perf_event_ctx_lock(struct perf_event
*event
)
1223 return perf_event_ctx_lock_nested(event
, 0);
1226 static void perf_event_ctx_unlock(struct perf_event
*event
,
1227 struct perf_event_context
*ctx
)
1229 mutex_unlock(&ctx
->mutex
);
1234 * This must be done under the ctx->lock, such as to serialize against
1235 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1236 * calling scheduler related locks and ctx->lock nests inside those.
1238 static __must_check
struct perf_event_context
*
1239 unclone_ctx(struct perf_event_context
*ctx
)
1241 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1243 lockdep_assert_held(&ctx
->lock
);
1246 ctx
->parent_ctx
= NULL
;
1252 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1257 * only top level events have the pid namespace they were created in
1260 event
= event
->parent
;
1262 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1263 /* avoid -1 if it is idle thread or runs in another ns */
1264 if (!nr
&& !pid_alive(p
))
1269 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1271 return perf_event_pid_type(event
, p
, __PIDTYPE_TGID
);
1274 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1276 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1280 * If we inherit events we want to return the parent event id
1283 static u64
primary_event_id(struct perf_event
*event
)
1288 id
= event
->parent
->id
;
1294 * Get the perf_event_context for a task and lock it.
1296 * This has to cope with with the fact that until it is locked,
1297 * the context could get moved to another task.
1299 static struct perf_event_context
*
1300 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1302 struct perf_event_context
*ctx
;
1306 * One of the few rules of preemptible RCU is that one cannot do
1307 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1308 * part of the read side critical section was irqs-enabled -- see
1309 * rcu_read_unlock_special().
1311 * Since ctx->lock nests under rq->lock we must ensure the entire read
1312 * side critical section has interrupts disabled.
1314 local_irq_save(*flags
);
1316 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1319 * If this context is a clone of another, it might
1320 * get swapped for another underneath us by
1321 * perf_event_task_sched_out, though the
1322 * rcu_read_lock() protects us from any context
1323 * getting freed. Lock the context and check if it
1324 * got swapped before we could get the lock, and retry
1325 * if so. If we locked the right context, then it
1326 * can't get swapped on us any more.
1328 raw_spin_lock(&ctx
->lock
);
1329 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1330 raw_spin_unlock(&ctx
->lock
);
1332 local_irq_restore(*flags
);
1336 if (ctx
->task
== TASK_TOMBSTONE
||
1337 !atomic_inc_not_zero(&ctx
->refcount
)) {
1338 raw_spin_unlock(&ctx
->lock
);
1341 WARN_ON_ONCE(ctx
->task
!= task
);
1346 local_irq_restore(*flags
);
1351 * Get the context for a task and increment its pin_count so it
1352 * can't get swapped to another task. This also increments its
1353 * reference count so that the context can't get freed.
1355 static struct perf_event_context
*
1356 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1358 struct perf_event_context
*ctx
;
1359 unsigned long flags
;
1361 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1364 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1369 static void perf_unpin_context(struct perf_event_context
*ctx
)
1371 unsigned long flags
;
1373 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1375 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1379 * Update the record of the current time in a context.
1381 static void update_context_time(struct perf_event_context
*ctx
)
1383 u64 now
= perf_clock();
1385 ctx
->time
+= now
- ctx
->timestamp
;
1386 ctx
->timestamp
= now
;
1389 static u64
perf_event_time(struct perf_event
*event
)
1391 struct perf_event_context
*ctx
= event
->ctx
;
1393 if (is_cgroup_event(event
))
1394 return perf_cgroup_event_time(event
);
1396 return ctx
? ctx
->time
: 0;
1400 * Update the total_time_enabled and total_time_running fields for a event.
1402 static void update_event_times(struct perf_event
*event
)
1404 struct perf_event_context
*ctx
= event
->ctx
;
1407 lockdep_assert_held(&ctx
->lock
);
1409 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1410 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1414 * in cgroup mode, time_enabled represents
1415 * the time the event was enabled AND active
1416 * tasks were in the monitored cgroup. This is
1417 * independent of the activity of the context as
1418 * there may be a mix of cgroup and non-cgroup events.
1420 * That is why we treat cgroup events differently
1423 if (is_cgroup_event(event
))
1424 run_end
= perf_cgroup_event_time(event
);
1425 else if (ctx
->is_active
)
1426 run_end
= ctx
->time
;
1428 run_end
= event
->tstamp_stopped
;
1430 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1432 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1433 run_end
= event
->tstamp_stopped
;
1435 run_end
= perf_event_time(event
);
1437 event
->total_time_running
= run_end
- event
->tstamp_running
;
1442 * Update total_time_enabled and total_time_running for all events in a group.
1444 static void update_group_times(struct perf_event
*leader
)
1446 struct perf_event
*event
;
1448 update_event_times(leader
);
1449 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1450 update_event_times(event
);
1453 static enum event_type_t
get_event_type(struct perf_event
*event
)
1455 struct perf_event_context
*ctx
= event
->ctx
;
1456 enum event_type_t event_type
;
1458 lockdep_assert_held(&ctx
->lock
);
1461 * It's 'group type', really, because if our group leader is
1462 * pinned, so are we.
1464 if (event
->group_leader
!= event
)
1465 event
= event
->group_leader
;
1467 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1469 event_type
|= EVENT_CPU
;
1474 static struct list_head
*
1475 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1477 if (event
->attr
.pinned
)
1478 return &ctx
->pinned_groups
;
1480 return &ctx
->flexible_groups
;
1484 * Add a event from the lists for its context.
1485 * Must be called with ctx->mutex and ctx->lock held.
1488 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1490 lockdep_assert_held(&ctx
->lock
);
1492 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1493 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1496 * If we're a stand alone event or group leader, we go to the context
1497 * list, group events are kept attached to the group so that
1498 * perf_group_detach can, at all times, locate all siblings.
1500 if (event
->group_leader
== event
) {
1501 struct list_head
*list
;
1503 event
->group_caps
= event
->event_caps
;
1505 list
= ctx_group_list(event
, ctx
);
1506 list_add_tail(&event
->group_entry
, list
);
1509 list_update_cgroup_event(event
, ctx
, true);
1511 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1513 if (event
->attr
.inherit_stat
)
1520 * Initialize event state based on the perf_event_attr::disabled.
1522 static inline void perf_event__state_init(struct perf_event
*event
)
1524 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1525 PERF_EVENT_STATE_INACTIVE
;
1528 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1530 int entry
= sizeof(u64
); /* value */
1534 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1535 size
+= sizeof(u64
);
1537 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1538 size
+= sizeof(u64
);
1540 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1541 entry
+= sizeof(u64
);
1543 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1545 size
+= sizeof(u64
);
1549 event
->read_size
= size
;
1552 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1554 struct perf_sample_data
*data
;
1557 if (sample_type
& PERF_SAMPLE_IP
)
1558 size
+= sizeof(data
->ip
);
1560 if (sample_type
& PERF_SAMPLE_ADDR
)
1561 size
+= sizeof(data
->addr
);
1563 if (sample_type
& PERF_SAMPLE_PERIOD
)
1564 size
+= sizeof(data
->period
);
1566 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1567 size
+= sizeof(data
->weight
);
1569 if (sample_type
& PERF_SAMPLE_READ
)
1570 size
+= event
->read_size
;
1572 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1573 size
+= sizeof(data
->data_src
.val
);
1575 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1576 size
+= sizeof(data
->txn
);
1578 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1579 size
+= sizeof(data
->phys_addr
);
1581 event
->header_size
= size
;
1585 * Called at perf_event creation and when events are attached/detached from a
1588 static void perf_event__header_size(struct perf_event
*event
)
1590 __perf_event_read_size(event
,
1591 event
->group_leader
->nr_siblings
);
1592 __perf_event_header_size(event
, event
->attr
.sample_type
);
1595 static void perf_event__id_header_size(struct perf_event
*event
)
1597 struct perf_sample_data
*data
;
1598 u64 sample_type
= event
->attr
.sample_type
;
1601 if (sample_type
& PERF_SAMPLE_TID
)
1602 size
+= sizeof(data
->tid_entry
);
1604 if (sample_type
& PERF_SAMPLE_TIME
)
1605 size
+= sizeof(data
->time
);
1607 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1608 size
+= sizeof(data
->id
);
1610 if (sample_type
& PERF_SAMPLE_ID
)
1611 size
+= sizeof(data
->id
);
1613 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1614 size
+= sizeof(data
->stream_id
);
1616 if (sample_type
& PERF_SAMPLE_CPU
)
1617 size
+= sizeof(data
->cpu_entry
);
1619 event
->id_header_size
= size
;
1622 static bool perf_event_validate_size(struct perf_event
*event
)
1625 * The values computed here will be over-written when we actually
1628 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1629 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1630 perf_event__id_header_size(event
);
1633 * Sum the lot; should not exceed the 64k limit we have on records.
1634 * Conservative limit to allow for callchains and other variable fields.
1636 if (event
->read_size
+ event
->header_size
+
1637 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1643 static void perf_group_attach(struct perf_event
*event
)
1645 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1647 lockdep_assert_held(&event
->ctx
->lock
);
1650 * We can have double attach due to group movement in perf_event_open.
1652 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1655 event
->attach_state
|= PERF_ATTACH_GROUP
;
1657 if (group_leader
== event
)
1660 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1662 group_leader
->group_caps
&= event
->event_caps
;
1664 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1665 group_leader
->nr_siblings
++;
1667 perf_event__header_size(group_leader
);
1669 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1670 perf_event__header_size(pos
);
1674 * Remove a event from the lists for its context.
1675 * Must be called with ctx->mutex and ctx->lock held.
1678 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1680 WARN_ON_ONCE(event
->ctx
!= ctx
);
1681 lockdep_assert_held(&ctx
->lock
);
1684 * We can have double detach due to exit/hot-unplug + close.
1686 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1689 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1691 list_update_cgroup_event(event
, ctx
, false);
1694 if (event
->attr
.inherit_stat
)
1697 list_del_rcu(&event
->event_entry
);
1699 if (event
->group_leader
== event
)
1700 list_del_init(&event
->group_entry
);
1702 update_group_times(event
);
1705 * If event was in error state, then keep it
1706 * that way, otherwise bogus counts will be
1707 * returned on read(). The only way to get out
1708 * of error state is by explicit re-enabling
1711 if (event
->state
> PERF_EVENT_STATE_OFF
)
1712 event
->state
= PERF_EVENT_STATE_OFF
;
1717 static void perf_group_detach(struct perf_event
*event
)
1719 struct perf_event
*sibling
, *tmp
;
1720 struct list_head
*list
= NULL
;
1722 lockdep_assert_held(&event
->ctx
->lock
);
1725 * We can have double detach due to exit/hot-unplug + close.
1727 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1730 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1733 * If this is a sibling, remove it from its group.
1735 if (event
->group_leader
!= event
) {
1736 list_del_init(&event
->group_entry
);
1737 event
->group_leader
->nr_siblings
--;
1741 if (!list_empty(&event
->group_entry
))
1742 list
= &event
->group_entry
;
1745 * If this was a group event with sibling events then
1746 * upgrade the siblings to singleton events by adding them
1747 * to whatever list we are on.
1749 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1751 list_move_tail(&sibling
->group_entry
, list
);
1752 sibling
->group_leader
= sibling
;
1754 /* Inherit group flags from the previous leader */
1755 sibling
->group_caps
= event
->group_caps
;
1757 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1761 perf_event__header_size(event
->group_leader
);
1763 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1764 perf_event__header_size(tmp
);
1767 static bool is_orphaned_event(struct perf_event
*event
)
1769 return event
->state
== PERF_EVENT_STATE_DEAD
;
1772 static inline int __pmu_filter_match(struct perf_event
*event
)
1774 struct pmu
*pmu
= event
->pmu
;
1775 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1779 * Check whether we should attempt to schedule an event group based on
1780 * PMU-specific filtering. An event group can consist of HW and SW events,
1781 * potentially with a SW leader, so we must check all the filters, to
1782 * determine whether a group is schedulable:
1784 static inline int pmu_filter_match(struct perf_event
*event
)
1786 struct perf_event
*child
;
1788 if (!__pmu_filter_match(event
))
1791 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1792 if (!__pmu_filter_match(child
))
1800 event_filter_match(struct perf_event
*event
)
1802 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1803 perf_cgroup_match(event
) && pmu_filter_match(event
);
1807 event_sched_out(struct perf_event
*event
,
1808 struct perf_cpu_context
*cpuctx
,
1809 struct perf_event_context
*ctx
)
1811 u64 tstamp
= perf_event_time(event
);
1814 WARN_ON_ONCE(event
->ctx
!= ctx
);
1815 lockdep_assert_held(&ctx
->lock
);
1818 * An event which could not be activated because of
1819 * filter mismatch still needs to have its timings
1820 * maintained, otherwise bogus information is return
1821 * via read() for time_enabled, time_running:
1823 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1824 !event_filter_match(event
)) {
1825 delta
= tstamp
- event
->tstamp_stopped
;
1826 event
->tstamp_running
+= delta
;
1827 event
->tstamp_stopped
= tstamp
;
1830 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1833 perf_pmu_disable(event
->pmu
);
1835 event
->tstamp_stopped
= tstamp
;
1836 event
->pmu
->del(event
, 0);
1838 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1839 if (event
->pending_disable
) {
1840 event
->pending_disable
= 0;
1841 event
->state
= PERF_EVENT_STATE_OFF
;
1844 if (!is_software_event(event
))
1845 cpuctx
->active_oncpu
--;
1846 if (!--ctx
->nr_active
)
1847 perf_event_ctx_deactivate(ctx
);
1848 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1850 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1851 cpuctx
->exclusive
= 0;
1853 perf_pmu_enable(event
->pmu
);
1857 group_sched_out(struct perf_event
*group_event
,
1858 struct perf_cpu_context
*cpuctx
,
1859 struct perf_event_context
*ctx
)
1861 struct perf_event
*event
;
1862 int state
= group_event
->state
;
1864 perf_pmu_disable(ctx
->pmu
);
1866 event_sched_out(group_event
, cpuctx
, ctx
);
1869 * Schedule out siblings (if any):
1871 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1872 event_sched_out(event
, cpuctx
, ctx
);
1874 perf_pmu_enable(ctx
->pmu
);
1876 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1877 cpuctx
->exclusive
= 0;
1880 #define DETACH_GROUP 0x01UL
1883 * Cross CPU call to remove a performance event
1885 * We disable the event on the hardware level first. After that we
1886 * remove it from the context list.
1889 __perf_remove_from_context(struct perf_event
*event
,
1890 struct perf_cpu_context
*cpuctx
,
1891 struct perf_event_context
*ctx
,
1894 unsigned long flags
= (unsigned long)info
;
1896 event_sched_out(event
, cpuctx
, ctx
);
1897 if (flags
& DETACH_GROUP
)
1898 perf_group_detach(event
);
1899 list_del_event(event
, ctx
);
1901 if (!ctx
->nr_events
&& ctx
->is_active
) {
1904 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1905 cpuctx
->task_ctx
= NULL
;
1911 * Remove the event from a task's (or a CPU's) list of events.
1913 * If event->ctx is a cloned context, callers must make sure that
1914 * every task struct that event->ctx->task could possibly point to
1915 * remains valid. This is OK when called from perf_release since
1916 * that only calls us on the top-level context, which can't be a clone.
1917 * When called from perf_event_exit_task, it's OK because the
1918 * context has been detached from its task.
1920 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1922 struct perf_event_context
*ctx
= event
->ctx
;
1924 lockdep_assert_held(&ctx
->mutex
);
1926 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1929 * The above event_function_call() can NO-OP when it hits
1930 * TASK_TOMBSTONE. In that case we must already have been detached
1931 * from the context (by perf_event_exit_event()) but the grouping
1932 * might still be in-tact.
1934 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1935 if ((flags
& DETACH_GROUP
) &&
1936 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1938 * Since in that case we cannot possibly be scheduled, simply
1941 raw_spin_lock_irq(&ctx
->lock
);
1942 perf_group_detach(event
);
1943 raw_spin_unlock_irq(&ctx
->lock
);
1948 * Cross CPU call to disable a performance event
1950 static void __perf_event_disable(struct perf_event
*event
,
1951 struct perf_cpu_context
*cpuctx
,
1952 struct perf_event_context
*ctx
,
1955 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1958 update_context_time(ctx
);
1959 update_cgrp_time_from_event(event
);
1960 update_group_times(event
);
1961 if (event
== event
->group_leader
)
1962 group_sched_out(event
, cpuctx
, ctx
);
1964 event_sched_out(event
, cpuctx
, ctx
);
1965 event
->state
= PERF_EVENT_STATE_OFF
;
1971 * If event->ctx is a cloned context, callers must make sure that
1972 * every task struct that event->ctx->task could possibly point to
1973 * remains valid. This condition is satisifed when called through
1974 * perf_event_for_each_child or perf_event_for_each because they
1975 * hold the top-level event's child_mutex, so any descendant that
1976 * goes to exit will block in perf_event_exit_event().
1978 * When called from perf_pending_event it's OK because event->ctx
1979 * is the current context on this CPU and preemption is disabled,
1980 * hence we can't get into perf_event_task_sched_out for this context.
1982 static void _perf_event_disable(struct perf_event
*event
)
1984 struct perf_event_context
*ctx
= event
->ctx
;
1986 raw_spin_lock_irq(&ctx
->lock
);
1987 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1988 raw_spin_unlock_irq(&ctx
->lock
);
1991 raw_spin_unlock_irq(&ctx
->lock
);
1993 event_function_call(event
, __perf_event_disable
, NULL
);
1996 void perf_event_disable_local(struct perf_event
*event
)
1998 event_function_local(event
, __perf_event_disable
, NULL
);
2002 * Strictly speaking kernel users cannot create groups and therefore this
2003 * interface does not need the perf_event_ctx_lock() magic.
2005 void perf_event_disable(struct perf_event
*event
)
2007 struct perf_event_context
*ctx
;
2009 ctx
= perf_event_ctx_lock(event
);
2010 _perf_event_disable(event
);
2011 perf_event_ctx_unlock(event
, ctx
);
2013 EXPORT_SYMBOL_GPL(perf_event_disable
);
2015 void perf_event_disable_inatomic(struct perf_event
*event
)
2017 event
->pending_disable
= 1;
2018 irq_work_queue(&event
->pending
);
2021 static void perf_set_shadow_time(struct perf_event
*event
,
2022 struct perf_event_context
*ctx
,
2026 * use the correct time source for the time snapshot
2028 * We could get by without this by leveraging the
2029 * fact that to get to this function, the caller
2030 * has most likely already called update_context_time()
2031 * and update_cgrp_time_xx() and thus both timestamp
2032 * are identical (or very close). Given that tstamp is,
2033 * already adjusted for cgroup, we could say that:
2034 * tstamp - ctx->timestamp
2036 * tstamp - cgrp->timestamp.
2038 * Then, in perf_output_read(), the calculation would
2039 * work with no changes because:
2040 * - event is guaranteed scheduled in
2041 * - no scheduled out in between
2042 * - thus the timestamp would be the same
2044 * But this is a bit hairy.
2046 * So instead, we have an explicit cgroup call to remain
2047 * within the time time source all along. We believe it
2048 * is cleaner and simpler to understand.
2050 if (is_cgroup_event(event
))
2051 perf_cgroup_set_shadow_time(event
, tstamp
);
2053 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2056 #define MAX_INTERRUPTS (~0ULL)
2058 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2059 static void perf_log_itrace_start(struct perf_event
*event
);
2062 event_sched_in(struct perf_event
*event
,
2063 struct perf_cpu_context
*cpuctx
,
2064 struct perf_event_context
*ctx
)
2066 u64 tstamp
= perf_event_time(event
);
2069 lockdep_assert_held(&ctx
->lock
);
2071 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2074 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2076 * Order event::oncpu write to happen before the ACTIVE state
2080 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2083 * Unthrottle events, since we scheduled we might have missed several
2084 * ticks already, also for a heavily scheduling task there is little
2085 * guarantee it'll get a tick in a timely manner.
2087 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2088 perf_log_throttle(event
, 1);
2089 event
->hw
.interrupts
= 0;
2093 * The new state must be visible before we turn it on in the hardware:
2097 perf_pmu_disable(event
->pmu
);
2099 perf_set_shadow_time(event
, ctx
, tstamp
);
2101 perf_log_itrace_start(event
);
2103 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2104 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2110 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2112 if (!is_software_event(event
))
2113 cpuctx
->active_oncpu
++;
2114 if (!ctx
->nr_active
++)
2115 perf_event_ctx_activate(ctx
);
2116 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2119 if (event
->attr
.exclusive
)
2120 cpuctx
->exclusive
= 1;
2123 perf_pmu_enable(event
->pmu
);
2129 group_sched_in(struct perf_event
*group_event
,
2130 struct perf_cpu_context
*cpuctx
,
2131 struct perf_event_context
*ctx
)
2133 struct perf_event
*event
, *partial_group
= NULL
;
2134 struct pmu
*pmu
= ctx
->pmu
;
2135 u64 now
= ctx
->time
;
2136 bool simulate
= false;
2138 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2141 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2143 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2144 pmu
->cancel_txn(pmu
);
2145 perf_mux_hrtimer_restart(cpuctx
);
2150 * Schedule in siblings as one group (if any):
2152 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2153 if (event_sched_in(event
, cpuctx
, ctx
)) {
2154 partial_group
= event
;
2159 if (!pmu
->commit_txn(pmu
))
2164 * Groups can be scheduled in as one unit only, so undo any
2165 * partial group before returning:
2166 * The events up to the failed event are scheduled out normally,
2167 * tstamp_stopped will be updated.
2169 * The failed events and the remaining siblings need to have
2170 * their timings updated as if they had gone thru event_sched_in()
2171 * and event_sched_out(). This is required to get consistent timings
2172 * across the group. This also takes care of the case where the group
2173 * could never be scheduled by ensuring tstamp_stopped is set to mark
2174 * the time the event was actually stopped, such that time delta
2175 * calculation in update_event_times() is correct.
2177 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2178 if (event
== partial_group
)
2182 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2183 event
->tstamp_stopped
= now
;
2185 event_sched_out(event
, cpuctx
, ctx
);
2188 event_sched_out(group_event
, cpuctx
, ctx
);
2190 pmu
->cancel_txn(pmu
);
2192 perf_mux_hrtimer_restart(cpuctx
);
2198 * Work out whether we can put this event group on the CPU now.
2200 static int group_can_go_on(struct perf_event
*event
,
2201 struct perf_cpu_context
*cpuctx
,
2205 * Groups consisting entirely of software events can always go on.
2207 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2210 * If an exclusive group is already on, no other hardware
2213 if (cpuctx
->exclusive
)
2216 * If this group is exclusive and there are already
2217 * events on the CPU, it can't go on.
2219 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2222 * Otherwise, try to add it if all previous groups were able
2229 * Complement to update_event_times(). This computes the tstamp_* values to
2230 * continue 'enabled' state from @now, and effectively discards the time
2231 * between the prior tstamp_stopped and now (as we were in the OFF state, or
2232 * just switched (context) time base).
2234 * This further assumes '@event->state == INACTIVE' (we just came from OFF) and
2235 * cannot have been scheduled in yet. And going into INACTIVE state means
2236 * '@event->tstamp_stopped = @now'.
2238 * Thus given the rules of update_event_times():
2240 * total_time_enabled = tstamp_stopped - tstamp_enabled
2241 * total_time_running = tstamp_stopped - tstamp_running
2243 * We can insert 'tstamp_stopped == now' and reverse them to compute new
2246 static void __perf_event_enable_time(struct perf_event
*event
, u64 now
)
2248 WARN_ON_ONCE(event
->state
!= PERF_EVENT_STATE_INACTIVE
);
2250 event
->tstamp_stopped
= now
;
2251 event
->tstamp_enabled
= now
- event
->total_time_enabled
;
2252 event
->tstamp_running
= now
- event
->total_time_running
;
2255 static void add_event_to_ctx(struct perf_event
*event
,
2256 struct perf_event_context
*ctx
)
2258 u64 tstamp
= perf_event_time(event
);
2260 list_add_event(event
, ctx
);
2261 perf_group_attach(event
);
2263 * We can be called with event->state == STATE_OFF when we create with
2264 * .disabled = 1. In that case the IOC_ENABLE will call this function.
2266 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
2267 __perf_event_enable_time(event
, tstamp
);
2270 static void ctx_sched_out(struct perf_event_context
*ctx
,
2271 struct perf_cpu_context
*cpuctx
,
2272 enum event_type_t event_type
);
2274 ctx_sched_in(struct perf_event_context
*ctx
,
2275 struct perf_cpu_context
*cpuctx
,
2276 enum event_type_t event_type
,
2277 struct task_struct
*task
);
2279 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2280 struct perf_event_context
*ctx
,
2281 enum event_type_t event_type
)
2283 if (!cpuctx
->task_ctx
)
2286 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2289 ctx_sched_out(ctx
, cpuctx
, event_type
);
2292 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2293 struct perf_event_context
*ctx
,
2294 struct task_struct
*task
)
2296 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2298 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2299 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2301 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2305 * We want to maintain the following priority of scheduling:
2306 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2307 * - task pinned (EVENT_PINNED)
2308 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2309 * - task flexible (EVENT_FLEXIBLE).
2311 * In order to avoid unscheduling and scheduling back in everything every
2312 * time an event is added, only do it for the groups of equal priority and
2315 * This can be called after a batch operation on task events, in which case
2316 * event_type is a bit mask of the types of events involved. For CPU events,
2317 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2319 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2320 struct perf_event_context
*task_ctx
,
2321 enum event_type_t event_type
)
2323 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2324 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2327 * If pinned groups are involved, flexible groups also need to be
2330 if (event_type
& EVENT_PINNED
)
2331 event_type
|= EVENT_FLEXIBLE
;
2333 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2335 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2338 * Decide which cpu ctx groups to schedule out based on the types
2339 * of events that caused rescheduling:
2340 * - EVENT_CPU: schedule out corresponding groups;
2341 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2342 * - otherwise, do nothing more.
2345 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2346 else if (ctx_event_type
& EVENT_PINNED
)
2347 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2349 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2350 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2354 * Cross CPU call to install and enable a performance event
2356 * Very similar to remote_function() + event_function() but cannot assume that
2357 * things like ctx->is_active and cpuctx->task_ctx are set.
2359 static int __perf_install_in_context(void *info
)
2361 struct perf_event
*event
= info
;
2362 struct perf_event_context
*ctx
= event
->ctx
;
2363 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2364 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2365 bool reprogram
= true;
2368 raw_spin_lock(&cpuctx
->ctx
.lock
);
2370 raw_spin_lock(&ctx
->lock
);
2373 reprogram
= (ctx
->task
== current
);
2376 * If the task is running, it must be running on this CPU,
2377 * otherwise we cannot reprogram things.
2379 * If its not running, we don't care, ctx->lock will
2380 * serialize against it becoming runnable.
2382 if (task_curr(ctx
->task
) && !reprogram
) {
2387 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2388 } else if (task_ctx
) {
2389 raw_spin_lock(&task_ctx
->lock
);
2393 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2394 add_event_to_ctx(event
, ctx
);
2395 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2397 add_event_to_ctx(event
, ctx
);
2401 perf_ctx_unlock(cpuctx
, task_ctx
);
2407 * Attach a performance event to a context.
2409 * Very similar to event_function_call, see comment there.
2412 perf_install_in_context(struct perf_event_context
*ctx
,
2413 struct perf_event
*event
,
2416 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2418 lockdep_assert_held(&ctx
->mutex
);
2420 if (event
->cpu
!= -1)
2424 * Ensures that if we can observe event->ctx, both the event and ctx
2425 * will be 'complete'. See perf_iterate_sb_cpu().
2427 smp_store_release(&event
->ctx
, ctx
);
2430 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2435 * Should not happen, we validate the ctx is still alive before calling.
2437 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2441 * Installing events is tricky because we cannot rely on ctx->is_active
2442 * to be set in case this is the nr_events 0 -> 1 transition.
2444 * Instead we use task_curr(), which tells us if the task is running.
2445 * However, since we use task_curr() outside of rq::lock, we can race
2446 * against the actual state. This means the result can be wrong.
2448 * If we get a false positive, we retry, this is harmless.
2450 * If we get a false negative, things are complicated. If we are after
2451 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2452 * value must be correct. If we're before, it doesn't matter since
2453 * perf_event_context_sched_in() will program the counter.
2455 * However, this hinges on the remote context switch having observed
2456 * our task->perf_event_ctxp[] store, such that it will in fact take
2457 * ctx::lock in perf_event_context_sched_in().
2459 * We do this by task_function_call(), if the IPI fails to hit the task
2460 * we know any future context switch of task must see the
2461 * perf_event_ctpx[] store.
2465 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2466 * task_cpu() load, such that if the IPI then does not find the task
2467 * running, a future context switch of that task must observe the
2472 if (!task_function_call(task
, __perf_install_in_context
, event
))
2475 raw_spin_lock_irq(&ctx
->lock
);
2477 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2479 * Cannot happen because we already checked above (which also
2480 * cannot happen), and we hold ctx->mutex, which serializes us
2481 * against perf_event_exit_task_context().
2483 raw_spin_unlock_irq(&ctx
->lock
);
2487 * If the task is not running, ctx->lock will avoid it becoming so,
2488 * thus we can safely install the event.
2490 if (task_curr(task
)) {
2491 raw_spin_unlock_irq(&ctx
->lock
);
2494 add_event_to_ctx(event
, ctx
);
2495 raw_spin_unlock_irq(&ctx
->lock
);
2499 * Put a event into inactive state and update time fields.
2500 * Enabling the leader of a group effectively enables all
2501 * the group members that aren't explicitly disabled, so we
2502 * have to update their ->tstamp_enabled also.
2503 * Note: this works for group members as well as group leaders
2504 * since the non-leader members' sibling_lists will be empty.
2506 static void __perf_event_mark_enabled(struct perf_event
*event
)
2508 struct perf_event
*sub
;
2509 u64 tstamp
= perf_event_time(event
);
2511 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2512 __perf_event_enable_time(event
, tstamp
);
2513 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2514 /* XXX should not be > INACTIVE if event isn't */
2515 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2516 __perf_event_enable_time(sub
, tstamp
);
2521 * Cross CPU call to enable a performance event
2523 static void __perf_event_enable(struct perf_event
*event
,
2524 struct perf_cpu_context
*cpuctx
,
2525 struct perf_event_context
*ctx
,
2528 struct perf_event
*leader
= event
->group_leader
;
2529 struct perf_event_context
*task_ctx
;
2531 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2532 event
->state
<= PERF_EVENT_STATE_ERROR
)
2536 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2538 __perf_event_mark_enabled(event
);
2540 if (!ctx
->is_active
)
2543 if (!event_filter_match(event
)) {
2544 if (is_cgroup_event(event
))
2545 perf_cgroup_defer_enabled(event
);
2546 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2551 * If the event is in a group and isn't the group leader,
2552 * then don't put it on unless the group is on.
2554 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2555 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2559 task_ctx
= cpuctx
->task_ctx
;
2561 WARN_ON_ONCE(task_ctx
!= ctx
);
2563 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2569 * If event->ctx is a cloned context, callers must make sure that
2570 * every task struct that event->ctx->task could possibly point to
2571 * remains valid. This condition is satisfied when called through
2572 * perf_event_for_each_child or perf_event_for_each as described
2573 * for perf_event_disable.
2575 static void _perf_event_enable(struct perf_event
*event
)
2577 struct perf_event_context
*ctx
= event
->ctx
;
2579 raw_spin_lock_irq(&ctx
->lock
);
2580 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2581 event
->state
< PERF_EVENT_STATE_ERROR
) {
2582 raw_spin_unlock_irq(&ctx
->lock
);
2587 * If the event is in error state, clear that first.
2589 * That way, if we see the event in error state below, we know that it
2590 * has gone back into error state, as distinct from the task having
2591 * been scheduled away before the cross-call arrived.
2593 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2594 event
->state
= PERF_EVENT_STATE_OFF
;
2595 raw_spin_unlock_irq(&ctx
->lock
);
2597 event_function_call(event
, __perf_event_enable
, NULL
);
2601 * See perf_event_disable();
2603 void perf_event_enable(struct perf_event
*event
)
2605 struct perf_event_context
*ctx
;
2607 ctx
= perf_event_ctx_lock(event
);
2608 _perf_event_enable(event
);
2609 perf_event_ctx_unlock(event
, ctx
);
2611 EXPORT_SYMBOL_GPL(perf_event_enable
);
2613 struct stop_event_data
{
2614 struct perf_event
*event
;
2615 unsigned int restart
;
2618 static int __perf_event_stop(void *info
)
2620 struct stop_event_data
*sd
= info
;
2621 struct perf_event
*event
= sd
->event
;
2623 /* if it's already INACTIVE, do nothing */
2624 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2627 /* matches smp_wmb() in event_sched_in() */
2631 * There is a window with interrupts enabled before we get here,
2632 * so we need to check again lest we try to stop another CPU's event.
2634 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2637 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2640 * May race with the actual stop (through perf_pmu_output_stop()),
2641 * but it is only used for events with AUX ring buffer, and such
2642 * events will refuse to restart because of rb::aux_mmap_count==0,
2643 * see comments in perf_aux_output_begin().
2645 * Since this is happening on a event-local CPU, no trace is lost
2649 event
->pmu
->start(event
, 0);
2654 static int perf_event_stop(struct perf_event
*event
, int restart
)
2656 struct stop_event_data sd
= {
2663 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2666 /* matches smp_wmb() in event_sched_in() */
2670 * We only want to restart ACTIVE events, so if the event goes
2671 * inactive here (event->oncpu==-1), there's nothing more to do;
2672 * fall through with ret==-ENXIO.
2674 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2675 __perf_event_stop
, &sd
);
2676 } while (ret
== -EAGAIN
);
2682 * In order to contain the amount of racy and tricky in the address filter
2683 * configuration management, it is a two part process:
2685 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2686 * we update the addresses of corresponding vmas in
2687 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2688 * (p2) when an event is scheduled in (pmu::add), it calls
2689 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2690 * if the generation has changed since the previous call.
2692 * If (p1) happens while the event is active, we restart it to force (p2).
2694 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2695 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2697 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2698 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2700 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2703 void perf_event_addr_filters_sync(struct perf_event
*event
)
2705 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2707 if (!has_addr_filter(event
))
2710 raw_spin_lock(&ifh
->lock
);
2711 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2712 event
->pmu
->addr_filters_sync(event
);
2713 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2715 raw_spin_unlock(&ifh
->lock
);
2717 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2719 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2722 * not supported on inherited events
2724 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2727 atomic_add(refresh
, &event
->event_limit
);
2728 _perf_event_enable(event
);
2734 * See perf_event_disable()
2736 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2738 struct perf_event_context
*ctx
;
2741 ctx
= perf_event_ctx_lock(event
);
2742 ret
= _perf_event_refresh(event
, refresh
);
2743 perf_event_ctx_unlock(event
, ctx
);
2747 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2749 static void ctx_sched_out(struct perf_event_context
*ctx
,
2750 struct perf_cpu_context
*cpuctx
,
2751 enum event_type_t event_type
)
2753 int is_active
= ctx
->is_active
;
2754 struct perf_event
*event
;
2756 lockdep_assert_held(&ctx
->lock
);
2758 if (likely(!ctx
->nr_events
)) {
2760 * See __perf_remove_from_context().
2762 WARN_ON_ONCE(ctx
->is_active
);
2764 WARN_ON_ONCE(cpuctx
->task_ctx
);
2768 ctx
->is_active
&= ~event_type
;
2769 if (!(ctx
->is_active
& EVENT_ALL
))
2773 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2774 if (!ctx
->is_active
)
2775 cpuctx
->task_ctx
= NULL
;
2779 * Always update time if it was set; not only when it changes.
2780 * Otherwise we can 'forget' to update time for any but the last
2781 * context we sched out. For example:
2783 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2784 * ctx_sched_out(.event_type = EVENT_PINNED)
2786 * would only update time for the pinned events.
2788 if (is_active
& EVENT_TIME
) {
2789 /* update (and stop) ctx time */
2790 update_context_time(ctx
);
2791 update_cgrp_time_from_cpuctx(cpuctx
);
2794 is_active
^= ctx
->is_active
; /* changed bits */
2796 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2799 perf_pmu_disable(ctx
->pmu
);
2800 if (is_active
& EVENT_PINNED
) {
2801 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2802 group_sched_out(event
, cpuctx
, ctx
);
2805 if (is_active
& EVENT_FLEXIBLE
) {
2806 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2807 group_sched_out(event
, cpuctx
, ctx
);
2809 perf_pmu_enable(ctx
->pmu
);
2813 * Test whether two contexts are equivalent, i.e. whether they have both been
2814 * cloned from the same version of the same context.
2816 * Equivalence is measured using a generation number in the context that is
2817 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2818 * and list_del_event().
2820 static int context_equiv(struct perf_event_context
*ctx1
,
2821 struct perf_event_context
*ctx2
)
2823 lockdep_assert_held(&ctx1
->lock
);
2824 lockdep_assert_held(&ctx2
->lock
);
2826 /* Pinning disables the swap optimization */
2827 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2830 /* If ctx1 is the parent of ctx2 */
2831 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2834 /* If ctx2 is the parent of ctx1 */
2835 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2839 * If ctx1 and ctx2 have the same parent; we flatten the parent
2840 * hierarchy, see perf_event_init_context().
2842 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2843 ctx1
->parent_gen
== ctx2
->parent_gen
)
2850 static void __perf_event_sync_stat(struct perf_event
*event
,
2851 struct perf_event
*next_event
)
2855 if (!event
->attr
.inherit_stat
)
2859 * Update the event value, we cannot use perf_event_read()
2860 * because we're in the middle of a context switch and have IRQs
2861 * disabled, which upsets smp_call_function_single(), however
2862 * we know the event must be on the current CPU, therefore we
2863 * don't need to use it.
2865 switch (event
->state
) {
2866 case PERF_EVENT_STATE_ACTIVE
:
2867 event
->pmu
->read(event
);
2870 case PERF_EVENT_STATE_INACTIVE
:
2871 update_event_times(event
);
2879 * In order to keep per-task stats reliable we need to flip the event
2880 * values when we flip the contexts.
2882 value
= local64_read(&next_event
->count
);
2883 value
= local64_xchg(&event
->count
, value
);
2884 local64_set(&next_event
->count
, value
);
2886 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2887 swap(event
->total_time_running
, next_event
->total_time_running
);
2890 * Since we swizzled the values, update the user visible data too.
2892 perf_event_update_userpage(event
);
2893 perf_event_update_userpage(next_event
);
2896 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2897 struct perf_event_context
*next_ctx
)
2899 struct perf_event
*event
, *next_event
;
2904 update_context_time(ctx
);
2906 event
= list_first_entry(&ctx
->event_list
,
2907 struct perf_event
, event_entry
);
2909 next_event
= list_first_entry(&next_ctx
->event_list
,
2910 struct perf_event
, event_entry
);
2912 while (&event
->event_entry
!= &ctx
->event_list
&&
2913 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2915 __perf_event_sync_stat(event
, next_event
);
2917 event
= list_next_entry(event
, event_entry
);
2918 next_event
= list_next_entry(next_event
, event_entry
);
2922 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2923 struct task_struct
*next
)
2925 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2926 struct perf_event_context
*next_ctx
;
2927 struct perf_event_context
*parent
, *next_parent
;
2928 struct perf_cpu_context
*cpuctx
;
2934 cpuctx
= __get_cpu_context(ctx
);
2935 if (!cpuctx
->task_ctx
)
2939 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2943 parent
= rcu_dereference(ctx
->parent_ctx
);
2944 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2946 /* If neither context have a parent context; they cannot be clones. */
2947 if (!parent
&& !next_parent
)
2950 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2952 * Looks like the two contexts are clones, so we might be
2953 * able to optimize the context switch. We lock both
2954 * contexts and check that they are clones under the
2955 * lock (including re-checking that neither has been
2956 * uncloned in the meantime). It doesn't matter which
2957 * order we take the locks because no other cpu could
2958 * be trying to lock both of these tasks.
2960 raw_spin_lock(&ctx
->lock
);
2961 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2962 if (context_equiv(ctx
, next_ctx
)) {
2963 WRITE_ONCE(ctx
->task
, next
);
2964 WRITE_ONCE(next_ctx
->task
, task
);
2966 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2969 * RCU_INIT_POINTER here is safe because we've not
2970 * modified the ctx and the above modification of
2971 * ctx->task and ctx->task_ctx_data are immaterial
2972 * since those values are always verified under
2973 * ctx->lock which we're now holding.
2975 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2976 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2980 perf_event_sync_stat(ctx
, next_ctx
);
2982 raw_spin_unlock(&next_ctx
->lock
);
2983 raw_spin_unlock(&ctx
->lock
);
2989 raw_spin_lock(&ctx
->lock
);
2990 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2991 raw_spin_unlock(&ctx
->lock
);
2995 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2997 void perf_sched_cb_dec(struct pmu
*pmu
)
2999 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3001 this_cpu_dec(perf_sched_cb_usages
);
3003 if (!--cpuctx
->sched_cb_usage
)
3004 list_del(&cpuctx
->sched_cb_entry
);
3008 void perf_sched_cb_inc(struct pmu
*pmu
)
3010 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3012 if (!cpuctx
->sched_cb_usage
++)
3013 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3015 this_cpu_inc(perf_sched_cb_usages
);
3019 * This function provides the context switch callback to the lower code
3020 * layer. It is invoked ONLY when the context switch callback is enabled.
3022 * This callback is relevant even to per-cpu events; for example multi event
3023 * PEBS requires this to provide PID/TID information. This requires we flush
3024 * all queued PEBS records before we context switch to a new task.
3026 static void perf_pmu_sched_task(struct task_struct
*prev
,
3027 struct task_struct
*next
,
3030 struct perf_cpu_context
*cpuctx
;
3036 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3037 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3039 if (WARN_ON_ONCE(!pmu
->sched_task
))
3042 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3043 perf_pmu_disable(pmu
);
3045 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3047 perf_pmu_enable(pmu
);
3048 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3052 static void perf_event_switch(struct task_struct
*task
,
3053 struct task_struct
*next_prev
, bool sched_in
);
3055 #define for_each_task_context_nr(ctxn) \
3056 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3059 * Called from scheduler to remove the events of the current task,
3060 * with interrupts disabled.
3062 * We stop each event and update the event value in event->count.
3064 * This does not protect us against NMI, but disable()
3065 * sets the disabled bit in the control field of event _before_
3066 * accessing the event control register. If a NMI hits, then it will
3067 * not restart the event.
3069 void __perf_event_task_sched_out(struct task_struct
*task
,
3070 struct task_struct
*next
)
3074 if (__this_cpu_read(perf_sched_cb_usages
))
3075 perf_pmu_sched_task(task
, next
, false);
3077 if (atomic_read(&nr_switch_events
))
3078 perf_event_switch(task
, next
, false);
3080 for_each_task_context_nr(ctxn
)
3081 perf_event_context_sched_out(task
, ctxn
, next
);
3084 * if cgroup events exist on this CPU, then we need
3085 * to check if we have to switch out PMU state.
3086 * cgroup event are system-wide mode only
3088 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3089 perf_cgroup_sched_out(task
, next
);
3093 * Called with IRQs disabled
3095 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3096 enum event_type_t event_type
)
3098 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3102 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3103 struct perf_cpu_context
*cpuctx
)
3105 struct perf_event
*event
;
3107 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3108 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3110 if (!event_filter_match(event
))
3113 /* may need to reset tstamp_enabled */
3114 if (is_cgroup_event(event
))
3115 perf_cgroup_mark_enabled(event
, ctx
);
3117 if (group_can_go_on(event
, cpuctx
, 1))
3118 group_sched_in(event
, cpuctx
, ctx
);
3121 * If this pinned group hasn't been scheduled,
3122 * put it in error state.
3124 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3125 update_group_times(event
);
3126 event
->state
= PERF_EVENT_STATE_ERROR
;
3132 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3133 struct perf_cpu_context
*cpuctx
)
3135 struct perf_event
*event
;
3138 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3139 /* Ignore events in OFF or ERROR state */
3140 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3143 * Listen to the 'cpu' scheduling filter constraint
3146 if (!event_filter_match(event
))
3149 /* may need to reset tstamp_enabled */
3150 if (is_cgroup_event(event
))
3151 perf_cgroup_mark_enabled(event
, ctx
);
3153 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3154 if (group_sched_in(event
, cpuctx
, ctx
))
3161 ctx_sched_in(struct perf_event_context
*ctx
,
3162 struct perf_cpu_context
*cpuctx
,
3163 enum event_type_t event_type
,
3164 struct task_struct
*task
)
3166 int is_active
= ctx
->is_active
;
3169 lockdep_assert_held(&ctx
->lock
);
3171 if (likely(!ctx
->nr_events
))
3174 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3177 cpuctx
->task_ctx
= ctx
;
3179 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3182 is_active
^= ctx
->is_active
; /* changed bits */
3184 if (is_active
& EVENT_TIME
) {
3185 /* start ctx time */
3187 ctx
->timestamp
= now
;
3188 perf_cgroup_set_timestamp(task
, ctx
);
3192 * First go through the list and put on any pinned groups
3193 * in order to give them the best chance of going on.
3195 if (is_active
& EVENT_PINNED
)
3196 ctx_pinned_sched_in(ctx
, cpuctx
);
3198 /* Then walk through the lower prio flexible groups */
3199 if (is_active
& EVENT_FLEXIBLE
)
3200 ctx_flexible_sched_in(ctx
, cpuctx
);
3203 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3204 enum event_type_t event_type
,
3205 struct task_struct
*task
)
3207 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3209 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3212 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3213 struct task_struct
*task
)
3215 struct perf_cpu_context
*cpuctx
;
3217 cpuctx
= __get_cpu_context(ctx
);
3218 if (cpuctx
->task_ctx
== ctx
)
3221 perf_ctx_lock(cpuctx
, ctx
);
3223 * We must check ctx->nr_events while holding ctx->lock, such
3224 * that we serialize against perf_install_in_context().
3226 if (!ctx
->nr_events
)
3229 perf_pmu_disable(ctx
->pmu
);
3231 * We want to keep the following priority order:
3232 * cpu pinned (that don't need to move), task pinned,
3233 * cpu flexible, task flexible.
3235 * However, if task's ctx is not carrying any pinned
3236 * events, no need to flip the cpuctx's events around.
3238 if (!list_empty(&ctx
->pinned_groups
))
3239 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3240 perf_event_sched_in(cpuctx
, ctx
, task
);
3241 perf_pmu_enable(ctx
->pmu
);
3244 perf_ctx_unlock(cpuctx
, ctx
);
3248 * Called from scheduler to add the events of the current task
3249 * with interrupts disabled.
3251 * We restore the event value and then enable it.
3253 * This does not protect us against NMI, but enable()
3254 * sets the enabled bit in the control field of event _before_
3255 * accessing the event control register. If a NMI hits, then it will
3256 * keep the event running.
3258 void __perf_event_task_sched_in(struct task_struct
*prev
,
3259 struct task_struct
*task
)
3261 struct perf_event_context
*ctx
;
3265 * If cgroup events exist on this CPU, then we need to check if we have
3266 * to switch in PMU state; cgroup event are system-wide mode only.
3268 * Since cgroup events are CPU events, we must schedule these in before
3269 * we schedule in the task events.
3271 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3272 perf_cgroup_sched_in(prev
, task
);
3274 for_each_task_context_nr(ctxn
) {
3275 ctx
= task
->perf_event_ctxp
[ctxn
];
3279 perf_event_context_sched_in(ctx
, task
);
3282 if (atomic_read(&nr_switch_events
))
3283 perf_event_switch(task
, prev
, true);
3285 if (__this_cpu_read(perf_sched_cb_usages
))
3286 perf_pmu_sched_task(prev
, task
, true);
3289 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3291 u64 frequency
= event
->attr
.sample_freq
;
3292 u64 sec
= NSEC_PER_SEC
;
3293 u64 divisor
, dividend
;
3295 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3297 count_fls
= fls64(count
);
3298 nsec_fls
= fls64(nsec
);
3299 frequency_fls
= fls64(frequency
);
3303 * We got @count in @nsec, with a target of sample_freq HZ
3304 * the target period becomes:
3307 * period = -------------------
3308 * @nsec * sample_freq
3313 * Reduce accuracy by one bit such that @a and @b converge
3314 * to a similar magnitude.
3316 #define REDUCE_FLS(a, b) \
3318 if (a##_fls > b##_fls) { \
3328 * Reduce accuracy until either term fits in a u64, then proceed with
3329 * the other, so that finally we can do a u64/u64 division.
3331 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3332 REDUCE_FLS(nsec
, frequency
);
3333 REDUCE_FLS(sec
, count
);
3336 if (count_fls
+ sec_fls
> 64) {
3337 divisor
= nsec
* frequency
;
3339 while (count_fls
+ sec_fls
> 64) {
3340 REDUCE_FLS(count
, sec
);
3344 dividend
= count
* sec
;
3346 dividend
= count
* sec
;
3348 while (nsec_fls
+ frequency_fls
> 64) {
3349 REDUCE_FLS(nsec
, frequency
);
3353 divisor
= nsec
* frequency
;
3359 return div64_u64(dividend
, divisor
);
3362 static DEFINE_PER_CPU(int, perf_throttled_count
);
3363 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3365 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3367 struct hw_perf_event
*hwc
= &event
->hw
;
3368 s64 period
, sample_period
;
3371 period
= perf_calculate_period(event
, nsec
, count
);
3373 delta
= (s64
)(period
- hwc
->sample_period
);
3374 delta
= (delta
+ 7) / 8; /* low pass filter */
3376 sample_period
= hwc
->sample_period
+ delta
;
3381 hwc
->sample_period
= sample_period
;
3383 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3385 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3387 local64_set(&hwc
->period_left
, 0);
3390 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3395 * combine freq adjustment with unthrottling to avoid two passes over the
3396 * events. At the same time, make sure, having freq events does not change
3397 * the rate of unthrottling as that would introduce bias.
3399 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3402 struct perf_event
*event
;
3403 struct hw_perf_event
*hwc
;
3404 u64 now
, period
= TICK_NSEC
;
3408 * only need to iterate over all events iff:
3409 * - context have events in frequency mode (needs freq adjust)
3410 * - there are events to unthrottle on this cpu
3412 if (!(ctx
->nr_freq
|| needs_unthr
))
3415 raw_spin_lock(&ctx
->lock
);
3416 perf_pmu_disable(ctx
->pmu
);
3418 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3419 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3422 if (!event_filter_match(event
))
3425 perf_pmu_disable(event
->pmu
);
3429 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3430 hwc
->interrupts
= 0;
3431 perf_log_throttle(event
, 1);
3432 event
->pmu
->start(event
, 0);
3435 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3439 * stop the event and update event->count
3441 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3443 now
= local64_read(&event
->count
);
3444 delta
= now
- hwc
->freq_count_stamp
;
3445 hwc
->freq_count_stamp
= now
;
3449 * reload only if value has changed
3450 * we have stopped the event so tell that
3451 * to perf_adjust_period() to avoid stopping it
3455 perf_adjust_period(event
, period
, delta
, false);
3457 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3459 perf_pmu_enable(event
->pmu
);
3462 perf_pmu_enable(ctx
->pmu
);
3463 raw_spin_unlock(&ctx
->lock
);
3467 * Round-robin a context's events:
3469 static void rotate_ctx(struct perf_event_context
*ctx
)
3472 * Rotate the first entry last of non-pinned groups. Rotation might be
3473 * disabled by the inheritance code.
3475 if (!ctx
->rotate_disable
)
3476 list_rotate_left(&ctx
->flexible_groups
);
3479 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3481 struct perf_event_context
*ctx
= NULL
;
3484 if (cpuctx
->ctx
.nr_events
) {
3485 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3489 ctx
= cpuctx
->task_ctx
;
3490 if (ctx
&& ctx
->nr_events
) {
3491 if (ctx
->nr_events
!= ctx
->nr_active
)
3498 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3499 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3501 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3503 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3505 rotate_ctx(&cpuctx
->ctx
);
3509 perf_event_sched_in(cpuctx
, ctx
, current
);
3511 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3512 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3518 void perf_event_task_tick(void)
3520 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3521 struct perf_event_context
*ctx
, *tmp
;
3524 WARN_ON(!irqs_disabled());
3526 __this_cpu_inc(perf_throttled_seq
);
3527 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3528 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3530 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3531 perf_adjust_freq_unthr_context(ctx
, throttled
);
3534 static int event_enable_on_exec(struct perf_event
*event
,
3535 struct perf_event_context
*ctx
)
3537 if (!event
->attr
.enable_on_exec
)
3540 event
->attr
.enable_on_exec
= 0;
3541 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3544 __perf_event_mark_enabled(event
);
3550 * Enable all of a task's events that have been marked enable-on-exec.
3551 * This expects task == current.
3553 static void perf_event_enable_on_exec(int ctxn
)
3555 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3556 enum event_type_t event_type
= 0;
3557 struct perf_cpu_context
*cpuctx
;
3558 struct perf_event
*event
;
3559 unsigned long flags
;
3562 local_irq_save(flags
);
3563 ctx
= current
->perf_event_ctxp
[ctxn
];
3564 if (!ctx
|| !ctx
->nr_events
)
3567 cpuctx
= __get_cpu_context(ctx
);
3568 perf_ctx_lock(cpuctx
, ctx
);
3569 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3570 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3571 enabled
|= event_enable_on_exec(event
, ctx
);
3572 event_type
|= get_event_type(event
);
3576 * Unclone and reschedule this context if we enabled any event.
3579 clone_ctx
= unclone_ctx(ctx
);
3580 ctx_resched(cpuctx
, ctx
, event_type
);
3582 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3584 perf_ctx_unlock(cpuctx
, ctx
);
3587 local_irq_restore(flags
);
3593 struct perf_read_data
{
3594 struct perf_event
*event
;
3599 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3601 u16 local_pkg
, event_pkg
;
3603 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3604 int local_cpu
= smp_processor_id();
3606 event_pkg
= topology_physical_package_id(event_cpu
);
3607 local_pkg
= topology_physical_package_id(local_cpu
);
3609 if (event_pkg
== local_pkg
)
3617 * Cross CPU call to read the hardware event
3619 static void __perf_event_read(void *info
)
3621 struct perf_read_data
*data
= info
;
3622 struct perf_event
*sub
, *event
= data
->event
;
3623 struct perf_event_context
*ctx
= event
->ctx
;
3624 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3625 struct pmu
*pmu
= event
->pmu
;
3628 * If this is a task context, we need to check whether it is
3629 * the current task context of this cpu. If not it has been
3630 * scheduled out before the smp call arrived. In that case
3631 * event->count would have been updated to a recent sample
3632 * when the event was scheduled out.
3634 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3637 raw_spin_lock(&ctx
->lock
);
3638 if (ctx
->is_active
) {
3639 update_context_time(ctx
);
3640 update_cgrp_time_from_event(event
);
3643 update_event_times(event
);
3644 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3653 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3657 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3658 update_event_times(sub
);
3659 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3661 * Use sibling's PMU rather than @event's since
3662 * sibling could be on different (eg: software) PMU.
3664 sub
->pmu
->read(sub
);
3668 data
->ret
= pmu
->commit_txn(pmu
);
3671 raw_spin_unlock(&ctx
->lock
);
3674 static inline u64
perf_event_count(struct perf_event
*event
)
3676 if (event
->pmu
->count
)
3677 return event
->pmu
->count(event
);
3679 return __perf_event_count(event
);
3683 * NMI-safe method to read a local event, that is an event that
3685 * - either for the current task, or for this CPU
3686 * - does not have inherit set, for inherited task events
3687 * will not be local and we cannot read them atomically
3688 * - must not have a pmu::count method
3690 int perf_event_read_local(struct perf_event
*event
, u64
*value
)
3692 unsigned long flags
;
3696 * Disabling interrupts avoids all counter scheduling (context
3697 * switches, timer based rotation and IPIs).
3699 local_irq_save(flags
);
3702 * It must not be an event with inherit set, we cannot read
3703 * all child counters from atomic context.
3705 if (event
->attr
.inherit
) {
3711 * It must not have a pmu::count method, those are not
3714 if (event
->pmu
->count
) {
3719 /* If this is a per-task event, it must be for current */
3720 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3721 event
->hw
.target
!= current
) {
3726 /* If this is a per-CPU event, it must be for this CPU */
3727 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3728 event
->cpu
!= smp_processor_id()) {
3734 * If the event is currently on this CPU, its either a per-task event,
3735 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3738 if (event
->oncpu
== smp_processor_id())
3739 event
->pmu
->read(event
);
3741 *value
= local64_read(&event
->count
);
3743 local_irq_restore(flags
);
3748 static int perf_event_read(struct perf_event
*event
, bool group
)
3750 int event_cpu
, ret
= 0;
3753 * If event is enabled and currently active on a CPU, update the
3754 * value in the event structure:
3756 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3757 struct perf_read_data data
= {
3763 event_cpu
= READ_ONCE(event
->oncpu
);
3764 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3768 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3771 * Purposely ignore the smp_call_function_single() return
3774 * If event_cpu isn't a valid CPU it means the event got
3775 * scheduled out and that will have updated the event count.
3777 * Therefore, either way, we'll have an up-to-date event count
3780 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3783 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3784 struct perf_event_context
*ctx
= event
->ctx
;
3785 unsigned long flags
;
3787 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3789 * may read while context is not active
3790 * (e.g., thread is blocked), in that case
3791 * we cannot update context time
3793 if (ctx
->is_active
) {
3794 update_context_time(ctx
);
3795 update_cgrp_time_from_event(event
);
3798 update_group_times(event
);
3800 update_event_times(event
);
3801 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3808 * Initialize the perf_event context in a task_struct:
3810 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3812 raw_spin_lock_init(&ctx
->lock
);
3813 mutex_init(&ctx
->mutex
);
3814 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3815 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3816 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3817 INIT_LIST_HEAD(&ctx
->event_list
);
3818 atomic_set(&ctx
->refcount
, 1);
3821 static struct perf_event_context
*
3822 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3824 struct perf_event_context
*ctx
;
3826 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3830 __perf_event_init_context(ctx
);
3833 get_task_struct(task
);
3840 static struct task_struct
*
3841 find_lively_task_by_vpid(pid_t vpid
)
3843 struct task_struct
*task
;
3849 task
= find_task_by_vpid(vpid
);
3851 get_task_struct(task
);
3855 return ERR_PTR(-ESRCH
);
3861 * Returns a matching context with refcount and pincount.
3863 static struct perf_event_context
*
3864 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3865 struct perf_event
*event
)
3867 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3868 struct perf_cpu_context
*cpuctx
;
3869 void *task_ctx_data
= NULL
;
3870 unsigned long flags
;
3872 int cpu
= event
->cpu
;
3875 /* Must be root to operate on a CPU event: */
3876 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3877 return ERR_PTR(-EACCES
);
3879 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3888 ctxn
= pmu
->task_ctx_nr
;
3892 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3893 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3894 if (!task_ctx_data
) {
3901 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3903 clone_ctx
= unclone_ctx(ctx
);
3906 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3907 ctx
->task_ctx_data
= task_ctx_data
;
3908 task_ctx_data
= NULL
;
3910 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3915 ctx
= alloc_perf_context(pmu
, task
);
3920 if (task_ctx_data
) {
3921 ctx
->task_ctx_data
= task_ctx_data
;
3922 task_ctx_data
= NULL
;
3926 mutex_lock(&task
->perf_event_mutex
);
3928 * If it has already passed perf_event_exit_task().
3929 * we must see PF_EXITING, it takes this mutex too.
3931 if (task
->flags
& PF_EXITING
)
3933 else if (task
->perf_event_ctxp
[ctxn
])
3938 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3940 mutex_unlock(&task
->perf_event_mutex
);
3942 if (unlikely(err
)) {
3951 kfree(task_ctx_data
);
3955 kfree(task_ctx_data
);
3956 return ERR_PTR(err
);
3959 static void perf_event_free_filter(struct perf_event
*event
);
3960 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3962 static void free_event_rcu(struct rcu_head
*head
)
3964 struct perf_event
*event
;
3966 event
= container_of(head
, struct perf_event
, rcu_head
);
3968 put_pid_ns(event
->ns
);
3969 perf_event_free_filter(event
);
3973 static void ring_buffer_attach(struct perf_event
*event
,
3974 struct ring_buffer
*rb
);
3976 static void detach_sb_event(struct perf_event
*event
)
3978 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3980 raw_spin_lock(&pel
->lock
);
3981 list_del_rcu(&event
->sb_list
);
3982 raw_spin_unlock(&pel
->lock
);
3985 static bool is_sb_event(struct perf_event
*event
)
3987 struct perf_event_attr
*attr
= &event
->attr
;
3992 if (event
->attach_state
& PERF_ATTACH_TASK
)
3995 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3996 attr
->comm
|| attr
->comm_exec
||
3998 attr
->context_switch
)
4003 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4005 if (is_sb_event(event
))
4006 detach_sb_event(event
);
4009 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4014 if (is_cgroup_event(event
))
4015 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4018 #ifdef CONFIG_NO_HZ_FULL
4019 static DEFINE_SPINLOCK(nr_freq_lock
);
4022 static void unaccount_freq_event_nohz(void)
4024 #ifdef CONFIG_NO_HZ_FULL
4025 spin_lock(&nr_freq_lock
);
4026 if (atomic_dec_and_test(&nr_freq_events
))
4027 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4028 spin_unlock(&nr_freq_lock
);
4032 static void unaccount_freq_event(void)
4034 if (tick_nohz_full_enabled())
4035 unaccount_freq_event_nohz();
4037 atomic_dec(&nr_freq_events
);
4040 static void unaccount_event(struct perf_event
*event
)
4047 if (event
->attach_state
& PERF_ATTACH_TASK
)
4049 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4050 atomic_dec(&nr_mmap_events
);
4051 if (event
->attr
.comm
)
4052 atomic_dec(&nr_comm_events
);
4053 if (event
->attr
.namespaces
)
4054 atomic_dec(&nr_namespaces_events
);
4055 if (event
->attr
.task
)
4056 atomic_dec(&nr_task_events
);
4057 if (event
->attr
.freq
)
4058 unaccount_freq_event();
4059 if (event
->attr
.context_switch
) {
4061 atomic_dec(&nr_switch_events
);
4063 if (is_cgroup_event(event
))
4065 if (has_branch_stack(event
))
4069 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4070 schedule_delayed_work(&perf_sched_work
, HZ
);
4073 unaccount_event_cpu(event
, event
->cpu
);
4075 unaccount_pmu_sb_event(event
);
4078 static void perf_sched_delayed(struct work_struct
*work
)
4080 mutex_lock(&perf_sched_mutex
);
4081 if (atomic_dec_and_test(&perf_sched_count
))
4082 static_branch_disable(&perf_sched_events
);
4083 mutex_unlock(&perf_sched_mutex
);
4087 * The following implement mutual exclusion of events on "exclusive" pmus
4088 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4089 * at a time, so we disallow creating events that might conflict, namely:
4091 * 1) cpu-wide events in the presence of per-task events,
4092 * 2) per-task events in the presence of cpu-wide events,
4093 * 3) two matching events on the same context.
4095 * The former two cases are handled in the allocation path (perf_event_alloc(),
4096 * _free_event()), the latter -- before the first perf_install_in_context().
4098 static int exclusive_event_init(struct perf_event
*event
)
4100 struct pmu
*pmu
= event
->pmu
;
4102 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4106 * Prevent co-existence of per-task and cpu-wide events on the
4107 * same exclusive pmu.
4109 * Negative pmu::exclusive_cnt means there are cpu-wide
4110 * events on this "exclusive" pmu, positive means there are
4113 * Since this is called in perf_event_alloc() path, event::ctx
4114 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4115 * to mean "per-task event", because unlike other attach states it
4116 * never gets cleared.
4118 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4119 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4122 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4129 static void exclusive_event_destroy(struct perf_event
*event
)
4131 struct pmu
*pmu
= event
->pmu
;
4133 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4136 /* see comment in exclusive_event_init() */
4137 if (event
->attach_state
& PERF_ATTACH_TASK
)
4138 atomic_dec(&pmu
->exclusive_cnt
);
4140 atomic_inc(&pmu
->exclusive_cnt
);
4143 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4145 if ((e1
->pmu
== e2
->pmu
) &&
4146 (e1
->cpu
== e2
->cpu
||
4153 /* Called under the same ctx::mutex as perf_install_in_context() */
4154 static bool exclusive_event_installable(struct perf_event
*event
,
4155 struct perf_event_context
*ctx
)
4157 struct perf_event
*iter_event
;
4158 struct pmu
*pmu
= event
->pmu
;
4160 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4163 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4164 if (exclusive_event_match(iter_event
, event
))
4171 static void perf_addr_filters_splice(struct perf_event
*event
,
4172 struct list_head
*head
);
4174 static void _free_event(struct perf_event
*event
)
4176 irq_work_sync(&event
->pending
);
4178 unaccount_event(event
);
4182 * Can happen when we close an event with re-directed output.
4184 * Since we have a 0 refcount, perf_mmap_close() will skip
4185 * over us; possibly making our ring_buffer_put() the last.
4187 mutex_lock(&event
->mmap_mutex
);
4188 ring_buffer_attach(event
, NULL
);
4189 mutex_unlock(&event
->mmap_mutex
);
4192 if (is_cgroup_event(event
))
4193 perf_detach_cgroup(event
);
4195 if (!event
->parent
) {
4196 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4197 put_callchain_buffers();
4200 perf_event_free_bpf_prog(event
);
4201 perf_addr_filters_splice(event
, NULL
);
4202 kfree(event
->addr_filters_offs
);
4205 event
->destroy(event
);
4208 put_ctx(event
->ctx
);
4210 exclusive_event_destroy(event
);
4211 module_put(event
->pmu
->module
);
4213 call_rcu(&event
->rcu_head
, free_event_rcu
);
4217 * Used to free events which have a known refcount of 1, such as in error paths
4218 * where the event isn't exposed yet and inherited events.
4220 static void free_event(struct perf_event
*event
)
4222 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4223 "unexpected event refcount: %ld; ptr=%p\n",
4224 atomic_long_read(&event
->refcount
), event
)) {
4225 /* leak to avoid use-after-free */
4233 * Remove user event from the owner task.
4235 static void perf_remove_from_owner(struct perf_event
*event
)
4237 struct task_struct
*owner
;
4241 * Matches the smp_store_release() in perf_event_exit_task(). If we
4242 * observe !owner it means the list deletion is complete and we can
4243 * indeed free this event, otherwise we need to serialize on
4244 * owner->perf_event_mutex.
4246 owner
= lockless_dereference(event
->owner
);
4249 * Since delayed_put_task_struct() also drops the last
4250 * task reference we can safely take a new reference
4251 * while holding the rcu_read_lock().
4253 get_task_struct(owner
);
4259 * If we're here through perf_event_exit_task() we're already
4260 * holding ctx->mutex which would be an inversion wrt. the
4261 * normal lock order.
4263 * However we can safely take this lock because its the child
4266 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4269 * We have to re-check the event->owner field, if it is cleared
4270 * we raced with perf_event_exit_task(), acquiring the mutex
4271 * ensured they're done, and we can proceed with freeing the
4275 list_del_init(&event
->owner_entry
);
4276 smp_store_release(&event
->owner
, NULL
);
4278 mutex_unlock(&owner
->perf_event_mutex
);
4279 put_task_struct(owner
);
4283 static void put_event(struct perf_event
*event
)
4285 if (!atomic_long_dec_and_test(&event
->refcount
))
4292 * Kill an event dead; while event:refcount will preserve the event
4293 * object, it will not preserve its functionality. Once the last 'user'
4294 * gives up the object, we'll destroy the thing.
4296 int perf_event_release_kernel(struct perf_event
*event
)
4298 struct perf_event_context
*ctx
= event
->ctx
;
4299 struct perf_event
*child
, *tmp
;
4302 * If we got here through err_file: fput(event_file); we will not have
4303 * attached to a context yet.
4306 WARN_ON_ONCE(event
->attach_state
&
4307 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4311 if (!is_kernel_event(event
))
4312 perf_remove_from_owner(event
);
4314 ctx
= perf_event_ctx_lock(event
);
4315 WARN_ON_ONCE(ctx
->parent_ctx
);
4316 perf_remove_from_context(event
, DETACH_GROUP
);
4318 raw_spin_lock_irq(&ctx
->lock
);
4320 * Mark this event as STATE_DEAD, there is no external reference to it
4323 * Anybody acquiring event->child_mutex after the below loop _must_
4324 * also see this, most importantly inherit_event() which will avoid
4325 * placing more children on the list.
4327 * Thus this guarantees that we will in fact observe and kill _ALL_
4330 event
->state
= PERF_EVENT_STATE_DEAD
;
4331 raw_spin_unlock_irq(&ctx
->lock
);
4333 perf_event_ctx_unlock(event
, ctx
);
4336 mutex_lock(&event
->child_mutex
);
4337 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4340 * Cannot change, child events are not migrated, see the
4341 * comment with perf_event_ctx_lock_nested().
4343 ctx
= lockless_dereference(child
->ctx
);
4345 * Since child_mutex nests inside ctx::mutex, we must jump
4346 * through hoops. We start by grabbing a reference on the ctx.
4348 * Since the event cannot get freed while we hold the
4349 * child_mutex, the context must also exist and have a !0
4355 * Now that we have a ctx ref, we can drop child_mutex, and
4356 * acquire ctx::mutex without fear of it going away. Then we
4357 * can re-acquire child_mutex.
4359 mutex_unlock(&event
->child_mutex
);
4360 mutex_lock(&ctx
->mutex
);
4361 mutex_lock(&event
->child_mutex
);
4364 * Now that we hold ctx::mutex and child_mutex, revalidate our
4365 * state, if child is still the first entry, it didn't get freed
4366 * and we can continue doing so.
4368 tmp
= list_first_entry_or_null(&event
->child_list
,
4369 struct perf_event
, child_list
);
4371 perf_remove_from_context(child
, DETACH_GROUP
);
4372 list_del(&child
->child_list
);
4375 * This matches the refcount bump in inherit_event();
4376 * this can't be the last reference.
4381 mutex_unlock(&event
->child_mutex
);
4382 mutex_unlock(&ctx
->mutex
);
4386 mutex_unlock(&event
->child_mutex
);
4389 put_event(event
); /* Must be the 'last' reference */
4392 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4395 * Called when the last reference to the file is gone.
4397 static int perf_release(struct inode
*inode
, struct file
*file
)
4399 perf_event_release_kernel(file
->private_data
);
4403 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4405 struct perf_event
*child
;
4411 mutex_lock(&event
->child_mutex
);
4413 (void)perf_event_read(event
, false);
4414 total
+= perf_event_count(event
);
4416 *enabled
+= event
->total_time_enabled
+
4417 atomic64_read(&event
->child_total_time_enabled
);
4418 *running
+= event
->total_time_running
+
4419 atomic64_read(&event
->child_total_time_running
);
4421 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4422 (void)perf_event_read(child
, false);
4423 total
+= perf_event_count(child
);
4424 *enabled
+= child
->total_time_enabled
;
4425 *running
+= child
->total_time_running
;
4427 mutex_unlock(&event
->child_mutex
);
4431 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4433 static int __perf_read_group_add(struct perf_event
*leader
,
4434 u64 read_format
, u64
*values
)
4436 struct perf_event_context
*ctx
= leader
->ctx
;
4437 struct perf_event
*sub
;
4438 unsigned long flags
;
4439 int n
= 1; /* skip @nr */
4442 ret
= perf_event_read(leader
, true);
4447 * Since we co-schedule groups, {enabled,running} times of siblings
4448 * will be identical to those of the leader, so we only publish one
4451 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4452 values
[n
++] += leader
->total_time_enabled
+
4453 atomic64_read(&leader
->child_total_time_enabled
);
4456 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4457 values
[n
++] += leader
->total_time_running
+
4458 atomic64_read(&leader
->child_total_time_running
);
4462 * Write {count,id} tuples for every sibling.
4464 values
[n
++] += perf_event_count(leader
);
4465 if (read_format
& PERF_FORMAT_ID
)
4466 values
[n
++] = primary_event_id(leader
);
4468 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4470 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4471 values
[n
++] += perf_event_count(sub
);
4472 if (read_format
& PERF_FORMAT_ID
)
4473 values
[n
++] = primary_event_id(sub
);
4476 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4480 static int perf_read_group(struct perf_event
*event
,
4481 u64 read_format
, char __user
*buf
)
4483 struct perf_event
*leader
= event
->group_leader
, *child
;
4484 struct perf_event_context
*ctx
= leader
->ctx
;
4488 lockdep_assert_held(&ctx
->mutex
);
4490 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4494 values
[0] = 1 + leader
->nr_siblings
;
4497 * By locking the child_mutex of the leader we effectively
4498 * lock the child list of all siblings.. XXX explain how.
4500 mutex_lock(&leader
->child_mutex
);
4502 ret
= __perf_read_group_add(leader
, read_format
, values
);
4506 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4507 ret
= __perf_read_group_add(child
, read_format
, values
);
4512 mutex_unlock(&leader
->child_mutex
);
4514 ret
= event
->read_size
;
4515 if (copy_to_user(buf
, values
, event
->read_size
))
4520 mutex_unlock(&leader
->child_mutex
);
4526 static int perf_read_one(struct perf_event
*event
,
4527 u64 read_format
, char __user
*buf
)
4529 u64 enabled
, running
;
4533 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4534 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4535 values
[n
++] = enabled
;
4536 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4537 values
[n
++] = running
;
4538 if (read_format
& PERF_FORMAT_ID
)
4539 values
[n
++] = primary_event_id(event
);
4541 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4544 return n
* sizeof(u64
);
4547 static bool is_event_hup(struct perf_event
*event
)
4551 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4554 mutex_lock(&event
->child_mutex
);
4555 no_children
= list_empty(&event
->child_list
);
4556 mutex_unlock(&event
->child_mutex
);
4561 * Read the performance event - simple non blocking version for now
4564 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4566 u64 read_format
= event
->attr
.read_format
;
4570 * Return end-of-file for a read on a event that is in
4571 * error state (i.e. because it was pinned but it couldn't be
4572 * scheduled on to the CPU at some point).
4574 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4577 if (count
< event
->read_size
)
4580 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4581 if (read_format
& PERF_FORMAT_GROUP
)
4582 ret
= perf_read_group(event
, read_format
, buf
);
4584 ret
= perf_read_one(event
, read_format
, buf
);
4590 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4592 struct perf_event
*event
= file
->private_data
;
4593 struct perf_event_context
*ctx
;
4596 ctx
= perf_event_ctx_lock(event
);
4597 ret
= __perf_read(event
, buf
, count
);
4598 perf_event_ctx_unlock(event
, ctx
);
4603 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4605 struct perf_event
*event
= file
->private_data
;
4606 struct ring_buffer
*rb
;
4607 unsigned int events
= POLLHUP
;
4609 poll_wait(file
, &event
->waitq
, wait
);
4611 if (is_event_hup(event
))
4615 * Pin the event->rb by taking event->mmap_mutex; otherwise
4616 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4618 mutex_lock(&event
->mmap_mutex
);
4621 events
= atomic_xchg(&rb
->poll
, 0);
4622 mutex_unlock(&event
->mmap_mutex
);
4626 static void _perf_event_reset(struct perf_event
*event
)
4628 (void)perf_event_read(event
, false);
4629 local64_set(&event
->count
, 0);
4630 perf_event_update_userpage(event
);
4634 * Holding the top-level event's child_mutex means that any
4635 * descendant process that has inherited this event will block
4636 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4637 * task existence requirements of perf_event_enable/disable.
4639 static void perf_event_for_each_child(struct perf_event
*event
,
4640 void (*func
)(struct perf_event
*))
4642 struct perf_event
*child
;
4644 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4646 mutex_lock(&event
->child_mutex
);
4648 list_for_each_entry(child
, &event
->child_list
, child_list
)
4650 mutex_unlock(&event
->child_mutex
);
4653 static void perf_event_for_each(struct perf_event
*event
,
4654 void (*func
)(struct perf_event
*))
4656 struct perf_event_context
*ctx
= event
->ctx
;
4657 struct perf_event
*sibling
;
4659 lockdep_assert_held(&ctx
->mutex
);
4661 event
= event
->group_leader
;
4663 perf_event_for_each_child(event
, func
);
4664 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4665 perf_event_for_each_child(sibling
, func
);
4668 static void __perf_event_period(struct perf_event
*event
,
4669 struct perf_cpu_context
*cpuctx
,
4670 struct perf_event_context
*ctx
,
4673 u64 value
= *((u64
*)info
);
4676 if (event
->attr
.freq
) {
4677 event
->attr
.sample_freq
= value
;
4679 event
->attr
.sample_period
= value
;
4680 event
->hw
.sample_period
= value
;
4683 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4685 perf_pmu_disable(ctx
->pmu
);
4687 * We could be throttled; unthrottle now to avoid the tick
4688 * trying to unthrottle while we already re-started the event.
4690 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4691 event
->hw
.interrupts
= 0;
4692 perf_log_throttle(event
, 1);
4694 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4697 local64_set(&event
->hw
.period_left
, 0);
4700 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4701 perf_pmu_enable(ctx
->pmu
);
4705 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4709 if (!is_sampling_event(event
))
4712 if (copy_from_user(&value
, arg
, sizeof(value
)))
4718 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4721 event_function_call(event
, __perf_event_period
, &value
);
4726 static const struct file_operations perf_fops
;
4728 static inline int perf_fget_light(int fd
, struct fd
*p
)
4730 struct fd f
= fdget(fd
);
4734 if (f
.file
->f_op
!= &perf_fops
) {
4742 static int perf_event_set_output(struct perf_event
*event
,
4743 struct perf_event
*output_event
);
4744 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4745 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4747 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4749 void (*func
)(struct perf_event
*);
4753 case PERF_EVENT_IOC_ENABLE
:
4754 func
= _perf_event_enable
;
4756 case PERF_EVENT_IOC_DISABLE
:
4757 func
= _perf_event_disable
;
4759 case PERF_EVENT_IOC_RESET
:
4760 func
= _perf_event_reset
;
4763 case PERF_EVENT_IOC_REFRESH
:
4764 return _perf_event_refresh(event
, arg
);
4766 case PERF_EVENT_IOC_PERIOD
:
4767 return perf_event_period(event
, (u64 __user
*)arg
);
4769 case PERF_EVENT_IOC_ID
:
4771 u64 id
= primary_event_id(event
);
4773 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4778 case PERF_EVENT_IOC_SET_OUTPUT
:
4782 struct perf_event
*output_event
;
4784 ret
= perf_fget_light(arg
, &output
);
4787 output_event
= output
.file
->private_data
;
4788 ret
= perf_event_set_output(event
, output_event
);
4791 ret
= perf_event_set_output(event
, NULL
);
4796 case PERF_EVENT_IOC_SET_FILTER
:
4797 return perf_event_set_filter(event
, (void __user
*)arg
);
4799 case PERF_EVENT_IOC_SET_BPF
:
4800 return perf_event_set_bpf_prog(event
, arg
);
4802 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4803 struct ring_buffer
*rb
;
4806 rb
= rcu_dereference(event
->rb
);
4807 if (!rb
|| !rb
->nr_pages
) {
4811 rb_toggle_paused(rb
, !!arg
);
4819 if (flags
& PERF_IOC_FLAG_GROUP
)
4820 perf_event_for_each(event
, func
);
4822 perf_event_for_each_child(event
, func
);
4827 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4829 struct perf_event
*event
= file
->private_data
;
4830 struct perf_event_context
*ctx
;
4833 ctx
= perf_event_ctx_lock(event
);
4834 ret
= _perf_ioctl(event
, cmd
, arg
);
4835 perf_event_ctx_unlock(event
, ctx
);
4840 #ifdef CONFIG_COMPAT
4841 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4844 switch (_IOC_NR(cmd
)) {
4845 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4846 case _IOC_NR(PERF_EVENT_IOC_ID
):
4847 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4848 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4849 cmd
&= ~IOCSIZE_MASK
;
4850 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4854 return perf_ioctl(file
, cmd
, arg
);
4857 # define perf_compat_ioctl NULL
4860 int perf_event_task_enable(void)
4862 struct perf_event_context
*ctx
;
4863 struct perf_event
*event
;
4865 mutex_lock(¤t
->perf_event_mutex
);
4866 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4867 ctx
= perf_event_ctx_lock(event
);
4868 perf_event_for_each_child(event
, _perf_event_enable
);
4869 perf_event_ctx_unlock(event
, ctx
);
4871 mutex_unlock(¤t
->perf_event_mutex
);
4876 int perf_event_task_disable(void)
4878 struct perf_event_context
*ctx
;
4879 struct perf_event
*event
;
4881 mutex_lock(¤t
->perf_event_mutex
);
4882 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4883 ctx
= perf_event_ctx_lock(event
);
4884 perf_event_for_each_child(event
, _perf_event_disable
);
4885 perf_event_ctx_unlock(event
, ctx
);
4887 mutex_unlock(¤t
->perf_event_mutex
);
4892 static int perf_event_index(struct perf_event
*event
)
4894 if (event
->hw
.state
& PERF_HES_STOPPED
)
4897 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4900 return event
->pmu
->event_idx(event
);
4903 static void calc_timer_values(struct perf_event
*event
,
4910 *now
= perf_clock();
4911 ctx_time
= event
->shadow_ctx_time
+ *now
;
4912 *enabled
= ctx_time
- event
->tstamp_enabled
;
4913 *running
= ctx_time
- event
->tstamp_running
;
4916 static void perf_event_init_userpage(struct perf_event
*event
)
4918 struct perf_event_mmap_page
*userpg
;
4919 struct ring_buffer
*rb
;
4922 rb
= rcu_dereference(event
->rb
);
4926 userpg
= rb
->user_page
;
4928 /* Allow new userspace to detect that bit 0 is deprecated */
4929 userpg
->cap_bit0_is_deprecated
= 1;
4930 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4931 userpg
->data_offset
= PAGE_SIZE
;
4932 userpg
->data_size
= perf_data_size(rb
);
4938 void __weak
arch_perf_update_userpage(
4939 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4944 * Callers need to ensure there can be no nesting of this function, otherwise
4945 * the seqlock logic goes bad. We can not serialize this because the arch
4946 * code calls this from NMI context.
4948 void perf_event_update_userpage(struct perf_event
*event
)
4950 struct perf_event_mmap_page
*userpg
;
4951 struct ring_buffer
*rb
;
4952 u64 enabled
, running
, now
;
4955 rb
= rcu_dereference(event
->rb
);
4960 * compute total_time_enabled, total_time_running
4961 * based on snapshot values taken when the event
4962 * was last scheduled in.
4964 * we cannot simply called update_context_time()
4965 * because of locking issue as we can be called in
4968 calc_timer_values(event
, &now
, &enabled
, &running
);
4970 userpg
= rb
->user_page
;
4972 * Disable preemption so as to not let the corresponding user-space
4973 * spin too long if we get preempted.
4978 userpg
->index
= perf_event_index(event
);
4979 userpg
->offset
= perf_event_count(event
);
4981 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4983 userpg
->time_enabled
= enabled
+
4984 atomic64_read(&event
->child_total_time_enabled
);
4986 userpg
->time_running
= running
+
4987 atomic64_read(&event
->child_total_time_running
);
4989 arch_perf_update_userpage(event
, userpg
, now
);
4998 static int perf_mmap_fault(struct vm_fault
*vmf
)
5000 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5001 struct ring_buffer
*rb
;
5002 int ret
= VM_FAULT_SIGBUS
;
5004 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5005 if (vmf
->pgoff
== 0)
5011 rb
= rcu_dereference(event
->rb
);
5015 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5018 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5022 get_page(vmf
->page
);
5023 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5024 vmf
->page
->index
= vmf
->pgoff
;
5033 static void ring_buffer_attach(struct perf_event
*event
,
5034 struct ring_buffer
*rb
)
5036 struct ring_buffer
*old_rb
= NULL
;
5037 unsigned long flags
;
5041 * Should be impossible, we set this when removing
5042 * event->rb_entry and wait/clear when adding event->rb_entry.
5044 WARN_ON_ONCE(event
->rcu_pending
);
5047 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5048 list_del_rcu(&event
->rb_entry
);
5049 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5051 event
->rcu_batches
= get_state_synchronize_rcu();
5052 event
->rcu_pending
= 1;
5056 if (event
->rcu_pending
) {
5057 cond_synchronize_rcu(event
->rcu_batches
);
5058 event
->rcu_pending
= 0;
5061 spin_lock_irqsave(&rb
->event_lock
, flags
);
5062 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5063 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5067 * Avoid racing with perf_mmap_close(AUX): stop the event
5068 * before swizzling the event::rb pointer; if it's getting
5069 * unmapped, its aux_mmap_count will be 0 and it won't
5070 * restart. See the comment in __perf_pmu_output_stop().
5072 * Data will inevitably be lost when set_output is done in
5073 * mid-air, but then again, whoever does it like this is
5074 * not in for the data anyway.
5077 perf_event_stop(event
, 0);
5079 rcu_assign_pointer(event
->rb
, rb
);
5082 ring_buffer_put(old_rb
);
5084 * Since we detached before setting the new rb, so that we
5085 * could attach the new rb, we could have missed a wakeup.
5088 wake_up_all(&event
->waitq
);
5092 static void ring_buffer_wakeup(struct perf_event
*event
)
5094 struct ring_buffer
*rb
;
5097 rb
= rcu_dereference(event
->rb
);
5099 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5100 wake_up_all(&event
->waitq
);
5105 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5107 struct ring_buffer
*rb
;
5110 rb
= rcu_dereference(event
->rb
);
5112 if (!atomic_inc_not_zero(&rb
->refcount
))
5120 void ring_buffer_put(struct ring_buffer
*rb
)
5122 if (!atomic_dec_and_test(&rb
->refcount
))
5125 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5127 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5130 static void perf_mmap_open(struct vm_area_struct
*vma
)
5132 struct perf_event
*event
= vma
->vm_file
->private_data
;
5134 atomic_inc(&event
->mmap_count
);
5135 atomic_inc(&event
->rb
->mmap_count
);
5138 atomic_inc(&event
->rb
->aux_mmap_count
);
5140 if (event
->pmu
->event_mapped
)
5141 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5144 static void perf_pmu_output_stop(struct perf_event
*event
);
5147 * A buffer can be mmap()ed multiple times; either directly through the same
5148 * event, or through other events by use of perf_event_set_output().
5150 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5151 * the buffer here, where we still have a VM context. This means we need
5152 * to detach all events redirecting to us.
5154 static void perf_mmap_close(struct vm_area_struct
*vma
)
5156 struct perf_event
*event
= vma
->vm_file
->private_data
;
5158 struct ring_buffer
*rb
= ring_buffer_get(event
);
5159 struct user_struct
*mmap_user
= rb
->mmap_user
;
5160 int mmap_locked
= rb
->mmap_locked
;
5161 unsigned long size
= perf_data_size(rb
);
5163 if (event
->pmu
->event_unmapped
)
5164 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5167 * rb->aux_mmap_count will always drop before rb->mmap_count and
5168 * event->mmap_count, so it is ok to use event->mmap_mutex to
5169 * serialize with perf_mmap here.
5171 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5172 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5174 * Stop all AUX events that are writing to this buffer,
5175 * so that we can free its AUX pages and corresponding PMU
5176 * data. Note that after rb::aux_mmap_count dropped to zero,
5177 * they won't start any more (see perf_aux_output_begin()).
5179 perf_pmu_output_stop(event
);
5181 /* now it's safe to free the pages */
5182 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5183 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5185 /* this has to be the last one */
5187 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5189 mutex_unlock(&event
->mmap_mutex
);
5192 atomic_dec(&rb
->mmap_count
);
5194 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5197 ring_buffer_attach(event
, NULL
);
5198 mutex_unlock(&event
->mmap_mutex
);
5200 /* If there's still other mmap()s of this buffer, we're done. */
5201 if (atomic_read(&rb
->mmap_count
))
5205 * No other mmap()s, detach from all other events that might redirect
5206 * into the now unreachable buffer. Somewhat complicated by the
5207 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5211 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5212 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5214 * This event is en-route to free_event() which will
5215 * detach it and remove it from the list.
5221 mutex_lock(&event
->mmap_mutex
);
5223 * Check we didn't race with perf_event_set_output() which can
5224 * swizzle the rb from under us while we were waiting to
5225 * acquire mmap_mutex.
5227 * If we find a different rb; ignore this event, a next
5228 * iteration will no longer find it on the list. We have to
5229 * still restart the iteration to make sure we're not now
5230 * iterating the wrong list.
5232 if (event
->rb
== rb
)
5233 ring_buffer_attach(event
, NULL
);
5235 mutex_unlock(&event
->mmap_mutex
);
5239 * Restart the iteration; either we're on the wrong list or
5240 * destroyed its integrity by doing a deletion.
5247 * It could be there's still a few 0-ref events on the list; they'll
5248 * get cleaned up by free_event() -- they'll also still have their
5249 * ref on the rb and will free it whenever they are done with it.
5251 * Aside from that, this buffer is 'fully' detached and unmapped,
5252 * undo the VM accounting.
5255 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5256 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5257 free_uid(mmap_user
);
5260 ring_buffer_put(rb
); /* could be last */
5263 static const struct vm_operations_struct perf_mmap_vmops
= {
5264 .open
= perf_mmap_open
,
5265 .close
= perf_mmap_close
, /* non mergable */
5266 .fault
= perf_mmap_fault
,
5267 .page_mkwrite
= perf_mmap_fault
,
5270 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5272 struct perf_event
*event
= file
->private_data
;
5273 unsigned long user_locked
, user_lock_limit
;
5274 struct user_struct
*user
= current_user();
5275 unsigned long locked
, lock_limit
;
5276 struct ring_buffer
*rb
= NULL
;
5277 unsigned long vma_size
;
5278 unsigned long nr_pages
;
5279 long user_extra
= 0, extra
= 0;
5280 int ret
= 0, flags
= 0;
5283 * Don't allow mmap() of inherited per-task counters. This would
5284 * create a performance issue due to all children writing to the
5287 if (event
->cpu
== -1 && event
->attr
.inherit
)
5290 if (!(vma
->vm_flags
& VM_SHARED
))
5293 vma_size
= vma
->vm_end
- vma
->vm_start
;
5295 if (vma
->vm_pgoff
== 0) {
5296 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5299 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5300 * mapped, all subsequent mappings should have the same size
5301 * and offset. Must be above the normal perf buffer.
5303 u64 aux_offset
, aux_size
;
5308 nr_pages
= vma_size
/ PAGE_SIZE
;
5310 mutex_lock(&event
->mmap_mutex
);
5317 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5318 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5320 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5323 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5326 /* already mapped with a different offset */
5327 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5330 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5333 /* already mapped with a different size */
5334 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5337 if (!is_power_of_2(nr_pages
))
5340 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5343 if (rb_has_aux(rb
)) {
5344 atomic_inc(&rb
->aux_mmap_count
);
5349 atomic_set(&rb
->aux_mmap_count
, 1);
5350 user_extra
= nr_pages
;
5356 * If we have rb pages ensure they're a power-of-two number, so we
5357 * can do bitmasks instead of modulo.
5359 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5362 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5365 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5367 mutex_lock(&event
->mmap_mutex
);
5369 if (event
->rb
->nr_pages
!= nr_pages
) {
5374 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5376 * Raced against perf_mmap_close() through
5377 * perf_event_set_output(). Try again, hope for better
5380 mutex_unlock(&event
->mmap_mutex
);
5387 user_extra
= nr_pages
+ 1;
5390 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5393 * Increase the limit linearly with more CPUs:
5395 user_lock_limit
*= num_online_cpus();
5397 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5399 if (user_locked
> user_lock_limit
)
5400 extra
= user_locked
- user_lock_limit
;
5402 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5403 lock_limit
>>= PAGE_SHIFT
;
5404 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5406 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5407 !capable(CAP_IPC_LOCK
)) {
5412 WARN_ON(!rb
&& event
->rb
);
5414 if (vma
->vm_flags
& VM_WRITE
)
5415 flags
|= RING_BUFFER_WRITABLE
;
5418 rb
= rb_alloc(nr_pages
,
5419 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5427 atomic_set(&rb
->mmap_count
, 1);
5428 rb
->mmap_user
= get_current_user();
5429 rb
->mmap_locked
= extra
;
5431 ring_buffer_attach(event
, rb
);
5433 perf_event_init_userpage(event
);
5434 perf_event_update_userpage(event
);
5436 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5437 event
->attr
.aux_watermark
, flags
);
5439 rb
->aux_mmap_locked
= extra
;
5444 atomic_long_add(user_extra
, &user
->locked_vm
);
5445 vma
->vm_mm
->pinned_vm
+= extra
;
5447 atomic_inc(&event
->mmap_count
);
5449 atomic_dec(&rb
->mmap_count
);
5452 mutex_unlock(&event
->mmap_mutex
);
5455 * Since pinned accounting is per vm we cannot allow fork() to copy our
5458 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5459 vma
->vm_ops
= &perf_mmap_vmops
;
5461 if (event
->pmu
->event_mapped
)
5462 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5467 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5469 struct inode
*inode
= file_inode(filp
);
5470 struct perf_event
*event
= filp
->private_data
;
5474 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5475 inode_unlock(inode
);
5483 static const struct file_operations perf_fops
= {
5484 .llseek
= no_llseek
,
5485 .release
= perf_release
,
5488 .unlocked_ioctl
= perf_ioctl
,
5489 .compat_ioctl
= perf_compat_ioctl
,
5491 .fasync
= perf_fasync
,
5497 * If there's data, ensure we set the poll() state and publish everything
5498 * to user-space before waking everybody up.
5501 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5503 /* only the parent has fasync state */
5505 event
= event
->parent
;
5506 return &event
->fasync
;
5509 void perf_event_wakeup(struct perf_event
*event
)
5511 ring_buffer_wakeup(event
);
5513 if (event
->pending_kill
) {
5514 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5515 event
->pending_kill
= 0;
5519 static void perf_pending_event(struct irq_work
*entry
)
5521 struct perf_event
*event
= container_of(entry
,
5522 struct perf_event
, pending
);
5525 rctx
= perf_swevent_get_recursion_context();
5527 * If we 'fail' here, that's OK, it means recursion is already disabled
5528 * and we won't recurse 'further'.
5531 if (event
->pending_disable
) {
5532 event
->pending_disable
= 0;
5533 perf_event_disable_local(event
);
5536 if (event
->pending_wakeup
) {
5537 event
->pending_wakeup
= 0;
5538 perf_event_wakeup(event
);
5542 perf_swevent_put_recursion_context(rctx
);
5546 * We assume there is only KVM supporting the callbacks.
5547 * Later on, we might change it to a list if there is
5548 * another virtualization implementation supporting the callbacks.
5550 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5552 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5554 perf_guest_cbs
= cbs
;
5557 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5559 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5561 perf_guest_cbs
= NULL
;
5564 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5567 perf_output_sample_regs(struct perf_output_handle
*handle
,
5568 struct pt_regs
*regs
, u64 mask
)
5571 DECLARE_BITMAP(_mask
, 64);
5573 bitmap_from_u64(_mask
, mask
);
5574 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5577 val
= perf_reg_value(regs
, bit
);
5578 perf_output_put(handle
, val
);
5582 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5583 struct pt_regs
*regs
,
5584 struct pt_regs
*regs_user_copy
)
5586 if (user_mode(regs
)) {
5587 regs_user
->abi
= perf_reg_abi(current
);
5588 regs_user
->regs
= regs
;
5589 } else if (current
->mm
) {
5590 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5592 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5593 regs_user
->regs
= NULL
;
5597 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5598 struct pt_regs
*regs
)
5600 regs_intr
->regs
= regs
;
5601 regs_intr
->abi
= perf_reg_abi(current
);
5606 * Get remaining task size from user stack pointer.
5608 * It'd be better to take stack vma map and limit this more
5609 * precisly, but there's no way to get it safely under interrupt,
5610 * so using TASK_SIZE as limit.
5612 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5614 unsigned long addr
= perf_user_stack_pointer(regs
);
5616 if (!addr
|| addr
>= TASK_SIZE
)
5619 return TASK_SIZE
- addr
;
5623 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5624 struct pt_regs
*regs
)
5628 /* No regs, no stack pointer, no dump. */
5633 * Check if we fit in with the requested stack size into the:
5635 * If we don't, we limit the size to the TASK_SIZE.
5637 * - remaining sample size
5638 * If we don't, we customize the stack size to
5639 * fit in to the remaining sample size.
5642 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5643 stack_size
= min(stack_size
, (u16
) task_size
);
5645 /* Current header size plus static size and dynamic size. */
5646 header_size
+= 2 * sizeof(u64
);
5648 /* Do we fit in with the current stack dump size? */
5649 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5651 * If we overflow the maximum size for the sample,
5652 * we customize the stack dump size to fit in.
5654 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5655 stack_size
= round_up(stack_size
, sizeof(u64
));
5662 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5663 struct pt_regs
*regs
)
5665 /* Case of a kernel thread, nothing to dump */
5668 perf_output_put(handle
, size
);
5677 * - the size requested by user or the best one we can fit
5678 * in to the sample max size
5680 * - user stack dump data
5682 * - the actual dumped size
5686 perf_output_put(handle
, dump_size
);
5689 sp
= perf_user_stack_pointer(regs
);
5690 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5691 dyn_size
= dump_size
- rem
;
5693 perf_output_skip(handle
, rem
);
5696 perf_output_put(handle
, dyn_size
);
5700 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5701 struct perf_sample_data
*data
,
5702 struct perf_event
*event
)
5704 u64 sample_type
= event
->attr
.sample_type
;
5706 data
->type
= sample_type
;
5707 header
->size
+= event
->id_header_size
;
5709 if (sample_type
& PERF_SAMPLE_TID
) {
5710 /* namespace issues */
5711 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5712 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5715 if (sample_type
& PERF_SAMPLE_TIME
)
5716 data
->time
= perf_event_clock(event
);
5718 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5719 data
->id
= primary_event_id(event
);
5721 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5722 data
->stream_id
= event
->id
;
5724 if (sample_type
& PERF_SAMPLE_CPU
) {
5725 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5726 data
->cpu_entry
.reserved
= 0;
5730 void perf_event_header__init_id(struct perf_event_header
*header
,
5731 struct perf_sample_data
*data
,
5732 struct perf_event
*event
)
5734 if (event
->attr
.sample_id_all
)
5735 __perf_event_header__init_id(header
, data
, event
);
5738 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5739 struct perf_sample_data
*data
)
5741 u64 sample_type
= data
->type
;
5743 if (sample_type
& PERF_SAMPLE_TID
)
5744 perf_output_put(handle
, data
->tid_entry
);
5746 if (sample_type
& PERF_SAMPLE_TIME
)
5747 perf_output_put(handle
, data
->time
);
5749 if (sample_type
& PERF_SAMPLE_ID
)
5750 perf_output_put(handle
, data
->id
);
5752 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5753 perf_output_put(handle
, data
->stream_id
);
5755 if (sample_type
& PERF_SAMPLE_CPU
)
5756 perf_output_put(handle
, data
->cpu_entry
);
5758 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5759 perf_output_put(handle
, data
->id
);
5762 void perf_event__output_id_sample(struct perf_event
*event
,
5763 struct perf_output_handle
*handle
,
5764 struct perf_sample_data
*sample
)
5766 if (event
->attr
.sample_id_all
)
5767 __perf_event__output_id_sample(handle
, sample
);
5770 static void perf_output_read_one(struct perf_output_handle
*handle
,
5771 struct perf_event
*event
,
5772 u64 enabled
, u64 running
)
5774 u64 read_format
= event
->attr
.read_format
;
5778 values
[n
++] = perf_event_count(event
);
5779 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5780 values
[n
++] = enabled
+
5781 atomic64_read(&event
->child_total_time_enabled
);
5783 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5784 values
[n
++] = running
+
5785 atomic64_read(&event
->child_total_time_running
);
5787 if (read_format
& PERF_FORMAT_ID
)
5788 values
[n
++] = primary_event_id(event
);
5790 __output_copy(handle
, values
, n
* sizeof(u64
));
5793 static void perf_output_read_group(struct perf_output_handle
*handle
,
5794 struct perf_event
*event
,
5795 u64 enabled
, u64 running
)
5797 struct perf_event
*leader
= event
->group_leader
, *sub
;
5798 u64 read_format
= event
->attr
.read_format
;
5802 values
[n
++] = 1 + leader
->nr_siblings
;
5804 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5805 values
[n
++] = enabled
;
5807 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5808 values
[n
++] = running
;
5810 if (leader
!= event
)
5811 leader
->pmu
->read(leader
);
5813 values
[n
++] = perf_event_count(leader
);
5814 if (read_format
& PERF_FORMAT_ID
)
5815 values
[n
++] = primary_event_id(leader
);
5817 __output_copy(handle
, values
, n
* sizeof(u64
));
5819 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5822 if ((sub
!= event
) &&
5823 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5824 sub
->pmu
->read(sub
);
5826 values
[n
++] = perf_event_count(sub
);
5827 if (read_format
& PERF_FORMAT_ID
)
5828 values
[n
++] = primary_event_id(sub
);
5830 __output_copy(handle
, values
, n
* sizeof(u64
));
5834 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5835 PERF_FORMAT_TOTAL_TIME_RUNNING)
5838 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5840 * The problem is that its both hard and excessively expensive to iterate the
5841 * child list, not to mention that its impossible to IPI the children running
5842 * on another CPU, from interrupt/NMI context.
5844 static void perf_output_read(struct perf_output_handle
*handle
,
5845 struct perf_event
*event
)
5847 u64 enabled
= 0, running
= 0, now
;
5848 u64 read_format
= event
->attr
.read_format
;
5851 * compute total_time_enabled, total_time_running
5852 * based on snapshot values taken when the event
5853 * was last scheduled in.
5855 * we cannot simply called update_context_time()
5856 * because of locking issue as we are called in
5859 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5860 calc_timer_values(event
, &now
, &enabled
, &running
);
5862 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5863 perf_output_read_group(handle
, event
, enabled
, running
);
5865 perf_output_read_one(handle
, event
, enabled
, running
);
5868 void perf_output_sample(struct perf_output_handle
*handle
,
5869 struct perf_event_header
*header
,
5870 struct perf_sample_data
*data
,
5871 struct perf_event
*event
)
5873 u64 sample_type
= data
->type
;
5875 perf_output_put(handle
, *header
);
5877 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5878 perf_output_put(handle
, data
->id
);
5880 if (sample_type
& PERF_SAMPLE_IP
)
5881 perf_output_put(handle
, data
->ip
);
5883 if (sample_type
& PERF_SAMPLE_TID
)
5884 perf_output_put(handle
, data
->tid_entry
);
5886 if (sample_type
& PERF_SAMPLE_TIME
)
5887 perf_output_put(handle
, data
->time
);
5889 if (sample_type
& PERF_SAMPLE_ADDR
)
5890 perf_output_put(handle
, data
->addr
);
5892 if (sample_type
& PERF_SAMPLE_ID
)
5893 perf_output_put(handle
, data
->id
);
5895 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5896 perf_output_put(handle
, data
->stream_id
);
5898 if (sample_type
& PERF_SAMPLE_CPU
)
5899 perf_output_put(handle
, data
->cpu_entry
);
5901 if (sample_type
& PERF_SAMPLE_PERIOD
)
5902 perf_output_put(handle
, data
->period
);
5904 if (sample_type
& PERF_SAMPLE_READ
)
5905 perf_output_read(handle
, event
);
5907 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5908 if (data
->callchain
) {
5911 if (data
->callchain
)
5912 size
+= data
->callchain
->nr
;
5914 size
*= sizeof(u64
);
5916 __output_copy(handle
, data
->callchain
, size
);
5919 perf_output_put(handle
, nr
);
5923 if (sample_type
& PERF_SAMPLE_RAW
) {
5924 struct perf_raw_record
*raw
= data
->raw
;
5927 struct perf_raw_frag
*frag
= &raw
->frag
;
5929 perf_output_put(handle
, raw
->size
);
5932 __output_custom(handle
, frag
->copy
,
5933 frag
->data
, frag
->size
);
5935 __output_copy(handle
, frag
->data
,
5938 if (perf_raw_frag_last(frag
))
5943 __output_skip(handle
, NULL
, frag
->pad
);
5949 .size
= sizeof(u32
),
5952 perf_output_put(handle
, raw
);
5956 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5957 if (data
->br_stack
) {
5960 size
= data
->br_stack
->nr
5961 * sizeof(struct perf_branch_entry
);
5963 perf_output_put(handle
, data
->br_stack
->nr
);
5964 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5967 * we always store at least the value of nr
5970 perf_output_put(handle
, nr
);
5974 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5975 u64 abi
= data
->regs_user
.abi
;
5978 * If there are no regs to dump, notice it through
5979 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5981 perf_output_put(handle
, abi
);
5984 u64 mask
= event
->attr
.sample_regs_user
;
5985 perf_output_sample_regs(handle
,
5986 data
->regs_user
.regs
,
5991 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5992 perf_output_sample_ustack(handle
,
5993 data
->stack_user_size
,
5994 data
->regs_user
.regs
);
5997 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5998 perf_output_put(handle
, data
->weight
);
6000 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6001 perf_output_put(handle
, data
->data_src
.val
);
6003 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6004 perf_output_put(handle
, data
->txn
);
6006 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6007 u64 abi
= data
->regs_intr
.abi
;
6009 * If there are no regs to dump, notice it through
6010 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6012 perf_output_put(handle
, abi
);
6015 u64 mask
= event
->attr
.sample_regs_intr
;
6017 perf_output_sample_regs(handle
,
6018 data
->regs_intr
.regs
,
6023 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6024 perf_output_put(handle
, data
->phys_addr
);
6026 if (!event
->attr
.watermark
) {
6027 int wakeup_events
= event
->attr
.wakeup_events
;
6029 if (wakeup_events
) {
6030 struct ring_buffer
*rb
= handle
->rb
;
6031 int events
= local_inc_return(&rb
->events
);
6033 if (events
>= wakeup_events
) {
6034 local_sub(wakeup_events
, &rb
->events
);
6035 local_inc(&rb
->wakeup
);
6041 static u64
perf_virt_to_phys(u64 virt
)
6044 struct page
*p
= NULL
;
6049 if (virt
>= TASK_SIZE
) {
6050 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6051 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6052 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6053 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6056 * Walking the pages tables for user address.
6057 * Interrupts are disabled, so it prevents any tear down
6058 * of the page tables.
6059 * Try IRQ-safe __get_user_pages_fast first.
6060 * If failed, leave phys_addr as 0.
6062 if ((current
->mm
!= NULL
) &&
6063 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6064 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6073 void perf_prepare_sample(struct perf_event_header
*header
,
6074 struct perf_sample_data
*data
,
6075 struct perf_event
*event
,
6076 struct pt_regs
*regs
)
6078 u64 sample_type
= event
->attr
.sample_type
;
6080 header
->type
= PERF_RECORD_SAMPLE
;
6081 header
->size
= sizeof(*header
) + event
->header_size
;
6084 header
->misc
|= perf_misc_flags(regs
);
6086 __perf_event_header__init_id(header
, data
, event
);
6088 if (sample_type
& PERF_SAMPLE_IP
)
6089 data
->ip
= perf_instruction_pointer(regs
);
6091 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6094 data
->callchain
= perf_callchain(event
, regs
);
6096 if (data
->callchain
)
6097 size
+= data
->callchain
->nr
;
6099 header
->size
+= size
* sizeof(u64
);
6102 if (sample_type
& PERF_SAMPLE_RAW
) {
6103 struct perf_raw_record
*raw
= data
->raw
;
6107 struct perf_raw_frag
*frag
= &raw
->frag
;
6112 if (perf_raw_frag_last(frag
))
6117 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6118 raw
->size
= size
- sizeof(u32
);
6119 frag
->pad
= raw
->size
- sum
;
6124 header
->size
+= size
;
6127 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6128 int size
= sizeof(u64
); /* nr */
6129 if (data
->br_stack
) {
6130 size
+= data
->br_stack
->nr
6131 * sizeof(struct perf_branch_entry
);
6133 header
->size
+= size
;
6136 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6137 perf_sample_regs_user(&data
->regs_user
, regs
,
6138 &data
->regs_user_copy
);
6140 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6141 /* regs dump ABI info */
6142 int size
= sizeof(u64
);
6144 if (data
->regs_user
.regs
) {
6145 u64 mask
= event
->attr
.sample_regs_user
;
6146 size
+= hweight64(mask
) * sizeof(u64
);
6149 header
->size
+= size
;
6152 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6154 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6155 * processed as the last one or have additional check added
6156 * in case new sample type is added, because we could eat
6157 * up the rest of the sample size.
6159 u16 stack_size
= event
->attr
.sample_stack_user
;
6160 u16 size
= sizeof(u64
);
6162 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6163 data
->regs_user
.regs
);
6166 * If there is something to dump, add space for the dump
6167 * itself and for the field that tells the dynamic size,
6168 * which is how many have been actually dumped.
6171 size
+= sizeof(u64
) + stack_size
;
6173 data
->stack_user_size
= stack_size
;
6174 header
->size
+= size
;
6177 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6178 /* regs dump ABI info */
6179 int size
= sizeof(u64
);
6181 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6183 if (data
->regs_intr
.regs
) {
6184 u64 mask
= event
->attr
.sample_regs_intr
;
6186 size
+= hweight64(mask
) * sizeof(u64
);
6189 header
->size
+= size
;
6192 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6193 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6196 static void __always_inline
6197 __perf_event_output(struct perf_event
*event
,
6198 struct perf_sample_data
*data
,
6199 struct pt_regs
*regs
,
6200 int (*output_begin
)(struct perf_output_handle
*,
6201 struct perf_event
*,
6204 struct perf_output_handle handle
;
6205 struct perf_event_header header
;
6207 /* protect the callchain buffers */
6210 perf_prepare_sample(&header
, data
, event
, regs
);
6212 if (output_begin(&handle
, event
, header
.size
))
6215 perf_output_sample(&handle
, &header
, data
, event
);
6217 perf_output_end(&handle
);
6224 perf_event_output_forward(struct perf_event
*event
,
6225 struct perf_sample_data
*data
,
6226 struct pt_regs
*regs
)
6228 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6232 perf_event_output_backward(struct perf_event
*event
,
6233 struct perf_sample_data
*data
,
6234 struct pt_regs
*regs
)
6236 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6240 perf_event_output(struct perf_event
*event
,
6241 struct perf_sample_data
*data
,
6242 struct pt_regs
*regs
)
6244 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6251 struct perf_read_event
{
6252 struct perf_event_header header
;
6259 perf_event_read_event(struct perf_event
*event
,
6260 struct task_struct
*task
)
6262 struct perf_output_handle handle
;
6263 struct perf_sample_data sample
;
6264 struct perf_read_event read_event
= {
6266 .type
= PERF_RECORD_READ
,
6268 .size
= sizeof(read_event
) + event
->read_size
,
6270 .pid
= perf_event_pid(event
, task
),
6271 .tid
= perf_event_tid(event
, task
),
6275 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6276 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6280 perf_output_put(&handle
, read_event
);
6281 perf_output_read(&handle
, event
);
6282 perf_event__output_id_sample(event
, &handle
, &sample
);
6284 perf_output_end(&handle
);
6287 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6290 perf_iterate_ctx(struct perf_event_context
*ctx
,
6291 perf_iterate_f output
,
6292 void *data
, bool all
)
6294 struct perf_event
*event
;
6296 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6298 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6300 if (!event_filter_match(event
))
6304 output(event
, data
);
6308 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6310 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6311 struct perf_event
*event
;
6313 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6315 * Skip events that are not fully formed yet; ensure that
6316 * if we observe event->ctx, both event and ctx will be
6317 * complete enough. See perf_install_in_context().
6319 if (!smp_load_acquire(&event
->ctx
))
6322 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6324 if (!event_filter_match(event
))
6326 output(event
, data
);
6331 * Iterate all events that need to receive side-band events.
6333 * For new callers; ensure that account_pmu_sb_event() includes
6334 * your event, otherwise it might not get delivered.
6337 perf_iterate_sb(perf_iterate_f output
, void *data
,
6338 struct perf_event_context
*task_ctx
)
6340 struct perf_event_context
*ctx
;
6347 * If we have task_ctx != NULL we only notify the task context itself.
6348 * The task_ctx is set only for EXIT events before releasing task
6352 perf_iterate_ctx(task_ctx
, output
, data
, false);
6356 perf_iterate_sb_cpu(output
, data
);
6358 for_each_task_context_nr(ctxn
) {
6359 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6361 perf_iterate_ctx(ctx
, output
, data
, false);
6369 * Clear all file-based filters at exec, they'll have to be
6370 * re-instated when/if these objects are mmapped again.
6372 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6374 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6375 struct perf_addr_filter
*filter
;
6376 unsigned int restart
= 0, count
= 0;
6377 unsigned long flags
;
6379 if (!has_addr_filter(event
))
6382 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6383 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6384 if (filter
->inode
) {
6385 event
->addr_filters_offs
[count
] = 0;
6393 event
->addr_filters_gen
++;
6394 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6397 perf_event_stop(event
, 1);
6400 void perf_event_exec(void)
6402 struct perf_event_context
*ctx
;
6406 for_each_task_context_nr(ctxn
) {
6407 ctx
= current
->perf_event_ctxp
[ctxn
];
6411 perf_event_enable_on_exec(ctxn
);
6413 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6419 struct remote_output
{
6420 struct ring_buffer
*rb
;
6424 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6426 struct perf_event
*parent
= event
->parent
;
6427 struct remote_output
*ro
= data
;
6428 struct ring_buffer
*rb
= ro
->rb
;
6429 struct stop_event_data sd
= {
6433 if (!has_aux(event
))
6440 * In case of inheritance, it will be the parent that links to the
6441 * ring-buffer, but it will be the child that's actually using it.
6443 * We are using event::rb to determine if the event should be stopped,
6444 * however this may race with ring_buffer_attach() (through set_output),
6445 * which will make us skip the event that actually needs to be stopped.
6446 * So ring_buffer_attach() has to stop an aux event before re-assigning
6449 if (rcu_dereference(parent
->rb
) == rb
)
6450 ro
->err
= __perf_event_stop(&sd
);
6453 static int __perf_pmu_output_stop(void *info
)
6455 struct perf_event
*event
= info
;
6456 struct pmu
*pmu
= event
->pmu
;
6457 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6458 struct remote_output ro
= {
6463 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6464 if (cpuctx
->task_ctx
)
6465 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6472 static void perf_pmu_output_stop(struct perf_event
*event
)
6474 struct perf_event
*iter
;
6479 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6481 * For per-CPU events, we need to make sure that neither they
6482 * nor their children are running; for cpu==-1 events it's
6483 * sufficient to stop the event itself if it's active, since
6484 * it can't have children.
6488 cpu
= READ_ONCE(iter
->oncpu
);
6493 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6494 if (err
== -EAGAIN
) {
6503 * task tracking -- fork/exit
6505 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6508 struct perf_task_event
{
6509 struct task_struct
*task
;
6510 struct perf_event_context
*task_ctx
;
6513 struct perf_event_header header
;
6523 static int perf_event_task_match(struct perf_event
*event
)
6525 return event
->attr
.comm
|| event
->attr
.mmap
||
6526 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6530 static void perf_event_task_output(struct perf_event
*event
,
6533 struct perf_task_event
*task_event
= data
;
6534 struct perf_output_handle handle
;
6535 struct perf_sample_data sample
;
6536 struct task_struct
*task
= task_event
->task
;
6537 int ret
, size
= task_event
->event_id
.header
.size
;
6539 if (!perf_event_task_match(event
))
6542 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6544 ret
= perf_output_begin(&handle
, event
,
6545 task_event
->event_id
.header
.size
);
6549 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6550 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6552 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6553 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6555 task_event
->event_id
.time
= perf_event_clock(event
);
6557 perf_output_put(&handle
, task_event
->event_id
);
6559 perf_event__output_id_sample(event
, &handle
, &sample
);
6561 perf_output_end(&handle
);
6563 task_event
->event_id
.header
.size
= size
;
6566 static void perf_event_task(struct task_struct
*task
,
6567 struct perf_event_context
*task_ctx
,
6570 struct perf_task_event task_event
;
6572 if (!atomic_read(&nr_comm_events
) &&
6573 !atomic_read(&nr_mmap_events
) &&
6574 !atomic_read(&nr_task_events
))
6577 task_event
= (struct perf_task_event
){
6579 .task_ctx
= task_ctx
,
6582 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6584 .size
= sizeof(task_event
.event_id
),
6594 perf_iterate_sb(perf_event_task_output
,
6599 void perf_event_fork(struct task_struct
*task
)
6601 perf_event_task(task
, NULL
, 1);
6602 perf_event_namespaces(task
);
6609 struct perf_comm_event
{
6610 struct task_struct
*task
;
6615 struct perf_event_header header
;
6622 static int perf_event_comm_match(struct perf_event
*event
)
6624 return event
->attr
.comm
;
6627 static void perf_event_comm_output(struct perf_event
*event
,
6630 struct perf_comm_event
*comm_event
= data
;
6631 struct perf_output_handle handle
;
6632 struct perf_sample_data sample
;
6633 int size
= comm_event
->event_id
.header
.size
;
6636 if (!perf_event_comm_match(event
))
6639 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6640 ret
= perf_output_begin(&handle
, event
,
6641 comm_event
->event_id
.header
.size
);
6646 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6647 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6649 perf_output_put(&handle
, comm_event
->event_id
);
6650 __output_copy(&handle
, comm_event
->comm
,
6651 comm_event
->comm_size
);
6653 perf_event__output_id_sample(event
, &handle
, &sample
);
6655 perf_output_end(&handle
);
6657 comm_event
->event_id
.header
.size
= size
;
6660 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6662 char comm
[TASK_COMM_LEN
];
6665 memset(comm
, 0, sizeof(comm
));
6666 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6667 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6669 comm_event
->comm
= comm
;
6670 comm_event
->comm_size
= size
;
6672 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6674 perf_iterate_sb(perf_event_comm_output
,
6679 void perf_event_comm(struct task_struct
*task
, bool exec
)
6681 struct perf_comm_event comm_event
;
6683 if (!atomic_read(&nr_comm_events
))
6686 comm_event
= (struct perf_comm_event
){
6692 .type
= PERF_RECORD_COMM
,
6693 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6701 perf_event_comm_event(&comm_event
);
6705 * namespaces tracking
6708 struct perf_namespaces_event
{
6709 struct task_struct
*task
;
6712 struct perf_event_header header
;
6717 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6721 static int perf_event_namespaces_match(struct perf_event
*event
)
6723 return event
->attr
.namespaces
;
6726 static void perf_event_namespaces_output(struct perf_event
*event
,
6729 struct perf_namespaces_event
*namespaces_event
= data
;
6730 struct perf_output_handle handle
;
6731 struct perf_sample_data sample
;
6734 if (!perf_event_namespaces_match(event
))
6737 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6739 ret
= perf_output_begin(&handle
, event
,
6740 namespaces_event
->event_id
.header
.size
);
6744 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6745 namespaces_event
->task
);
6746 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6747 namespaces_event
->task
);
6749 perf_output_put(&handle
, namespaces_event
->event_id
);
6751 perf_event__output_id_sample(event
, &handle
, &sample
);
6753 perf_output_end(&handle
);
6756 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6757 struct task_struct
*task
,
6758 const struct proc_ns_operations
*ns_ops
)
6760 struct path ns_path
;
6761 struct inode
*ns_inode
;
6764 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6766 ns_inode
= ns_path
.dentry
->d_inode
;
6767 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6768 ns_link_info
->ino
= ns_inode
->i_ino
;
6772 void perf_event_namespaces(struct task_struct
*task
)
6774 struct perf_namespaces_event namespaces_event
;
6775 struct perf_ns_link_info
*ns_link_info
;
6777 if (!atomic_read(&nr_namespaces_events
))
6780 namespaces_event
= (struct perf_namespaces_event
){
6784 .type
= PERF_RECORD_NAMESPACES
,
6786 .size
= sizeof(namespaces_event
.event_id
),
6790 .nr_namespaces
= NR_NAMESPACES
,
6791 /* .link_info[NR_NAMESPACES] */
6795 ns_link_info
= namespaces_event
.event_id
.link_info
;
6797 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6798 task
, &mntns_operations
);
6800 #ifdef CONFIG_USER_NS
6801 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6802 task
, &userns_operations
);
6804 #ifdef CONFIG_NET_NS
6805 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6806 task
, &netns_operations
);
6808 #ifdef CONFIG_UTS_NS
6809 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6810 task
, &utsns_operations
);
6812 #ifdef CONFIG_IPC_NS
6813 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6814 task
, &ipcns_operations
);
6816 #ifdef CONFIG_PID_NS
6817 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6818 task
, &pidns_operations
);
6820 #ifdef CONFIG_CGROUPS
6821 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6822 task
, &cgroupns_operations
);
6825 perf_iterate_sb(perf_event_namespaces_output
,
6834 struct perf_mmap_event
{
6835 struct vm_area_struct
*vma
;
6837 const char *file_name
;
6845 struct perf_event_header header
;
6855 static int perf_event_mmap_match(struct perf_event
*event
,
6858 struct perf_mmap_event
*mmap_event
= data
;
6859 struct vm_area_struct
*vma
= mmap_event
->vma
;
6860 int executable
= vma
->vm_flags
& VM_EXEC
;
6862 return (!executable
&& event
->attr
.mmap_data
) ||
6863 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6866 static void perf_event_mmap_output(struct perf_event
*event
,
6869 struct perf_mmap_event
*mmap_event
= data
;
6870 struct perf_output_handle handle
;
6871 struct perf_sample_data sample
;
6872 int size
= mmap_event
->event_id
.header
.size
;
6875 if (!perf_event_mmap_match(event
, data
))
6878 if (event
->attr
.mmap2
) {
6879 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6880 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6881 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6882 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6883 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6884 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6885 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6888 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6889 ret
= perf_output_begin(&handle
, event
,
6890 mmap_event
->event_id
.header
.size
);
6894 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6895 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6897 perf_output_put(&handle
, mmap_event
->event_id
);
6899 if (event
->attr
.mmap2
) {
6900 perf_output_put(&handle
, mmap_event
->maj
);
6901 perf_output_put(&handle
, mmap_event
->min
);
6902 perf_output_put(&handle
, mmap_event
->ino
);
6903 perf_output_put(&handle
, mmap_event
->ino_generation
);
6904 perf_output_put(&handle
, mmap_event
->prot
);
6905 perf_output_put(&handle
, mmap_event
->flags
);
6908 __output_copy(&handle
, mmap_event
->file_name
,
6909 mmap_event
->file_size
);
6911 perf_event__output_id_sample(event
, &handle
, &sample
);
6913 perf_output_end(&handle
);
6915 mmap_event
->event_id
.header
.size
= size
;
6918 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6920 struct vm_area_struct
*vma
= mmap_event
->vma
;
6921 struct file
*file
= vma
->vm_file
;
6922 int maj
= 0, min
= 0;
6923 u64 ino
= 0, gen
= 0;
6924 u32 prot
= 0, flags
= 0;
6930 if (vma
->vm_flags
& VM_READ
)
6932 if (vma
->vm_flags
& VM_WRITE
)
6934 if (vma
->vm_flags
& VM_EXEC
)
6937 if (vma
->vm_flags
& VM_MAYSHARE
)
6940 flags
= MAP_PRIVATE
;
6942 if (vma
->vm_flags
& VM_DENYWRITE
)
6943 flags
|= MAP_DENYWRITE
;
6944 if (vma
->vm_flags
& VM_MAYEXEC
)
6945 flags
|= MAP_EXECUTABLE
;
6946 if (vma
->vm_flags
& VM_LOCKED
)
6947 flags
|= MAP_LOCKED
;
6948 if (vma
->vm_flags
& VM_HUGETLB
)
6949 flags
|= MAP_HUGETLB
;
6952 struct inode
*inode
;
6955 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6961 * d_path() works from the end of the rb backwards, so we
6962 * need to add enough zero bytes after the string to handle
6963 * the 64bit alignment we do later.
6965 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6970 inode
= file_inode(vma
->vm_file
);
6971 dev
= inode
->i_sb
->s_dev
;
6973 gen
= inode
->i_generation
;
6979 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6980 name
= (char *) vma
->vm_ops
->name(vma
);
6985 name
= (char *)arch_vma_name(vma
);
6989 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6990 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6994 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6995 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
7005 strlcpy(tmp
, name
, sizeof(tmp
));
7009 * Since our buffer works in 8 byte units we need to align our string
7010 * size to a multiple of 8. However, we must guarantee the tail end is
7011 * zero'd out to avoid leaking random bits to userspace.
7013 size
= strlen(name
)+1;
7014 while (!IS_ALIGNED(size
, sizeof(u64
)))
7015 name
[size
++] = '\0';
7017 mmap_event
->file_name
= name
;
7018 mmap_event
->file_size
= size
;
7019 mmap_event
->maj
= maj
;
7020 mmap_event
->min
= min
;
7021 mmap_event
->ino
= ino
;
7022 mmap_event
->ino_generation
= gen
;
7023 mmap_event
->prot
= prot
;
7024 mmap_event
->flags
= flags
;
7026 if (!(vma
->vm_flags
& VM_EXEC
))
7027 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
7029 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7031 perf_iterate_sb(perf_event_mmap_output
,
7039 * Check whether inode and address range match filter criteria.
7041 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7042 struct file
*file
, unsigned long offset
,
7045 if (filter
->inode
!= file_inode(file
))
7048 if (filter
->offset
> offset
+ size
)
7051 if (filter
->offset
+ filter
->size
< offset
)
7057 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7059 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7060 struct vm_area_struct
*vma
= data
;
7061 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
7062 struct file
*file
= vma
->vm_file
;
7063 struct perf_addr_filter
*filter
;
7064 unsigned int restart
= 0, count
= 0;
7066 if (!has_addr_filter(event
))
7072 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7073 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7074 if (perf_addr_filter_match(filter
, file
, off
,
7075 vma
->vm_end
- vma
->vm_start
)) {
7076 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7084 event
->addr_filters_gen
++;
7085 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7088 perf_event_stop(event
, 1);
7092 * Adjust all task's events' filters to the new vma
7094 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7096 struct perf_event_context
*ctx
;
7100 * Data tracing isn't supported yet and as such there is no need
7101 * to keep track of anything that isn't related to executable code:
7103 if (!(vma
->vm_flags
& VM_EXEC
))
7107 for_each_task_context_nr(ctxn
) {
7108 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7112 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7117 void perf_event_mmap(struct vm_area_struct
*vma
)
7119 struct perf_mmap_event mmap_event
;
7121 if (!atomic_read(&nr_mmap_events
))
7124 mmap_event
= (struct perf_mmap_event
){
7130 .type
= PERF_RECORD_MMAP
,
7131 .misc
= PERF_RECORD_MISC_USER
,
7136 .start
= vma
->vm_start
,
7137 .len
= vma
->vm_end
- vma
->vm_start
,
7138 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7140 /* .maj (attr_mmap2 only) */
7141 /* .min (attr_mmap2 only) */
7142 /* .ino (attr_mmap2 only) */
7143 /* .ino_generation (attr_mmap2 only) */
7144 /* .prot (attr_mmap2 only) */
7145 /* .flags (attr_mmap2 only) */
7148 perf_addr_filters_adjust(vma
);
7149 perf_event_mmap_event(&mmap_event
);
7152 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7153 unsigned long size
, u64 flags
)
7155 struct perf_output_handle handle
;
7156 struct perf_sample_data sample
;
7157 struct perf_aux_event
{
7158 struct perf_event_header header
;
7164 .type
= PERF_RECORD_AUX
,
7166 .size
= sizeof(rec
),
7174 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7175 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7180 perf_output_put(&handle
, rec
);
7181 perf_event__output_id_sample(event
, &handle
, &sample
);
7183 perf_output_end(&handle
);
7187 * Lost/dropped samples logging
7189 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7191 struct perf_output_handle handle
;
7192 struct perf_sample_data sample
;
7196 struct perf_event_header header
;
7198 } lost_samples_event
= {
7200 .type
= PERF_RECORD_LOST_SAMPLES
,
7202 .size
= sizeof(lost_samples_event
),
7207 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7209 ret
= perf_output_begin(&handle
, event
,
7210 lost_samples_event
.header
.size
);
7214 perf_output_put(&handle
, lost_samples_event
);
7215 perf_event__output_id_sample(event
, &handle
, &sample
);
7216 perf_output_end(&handle
);
7220 * context_switch tracking
7223 struct perf_switch_event
{
7224 struct task_struct
*task
;
7225 struct task_struct
*next_prev
;
7228 struct perf_event_header header
;
7234 static int perf_event_switch_match(struct perf_event
*event
)
7236 return event
->attr
.context_switch
;
7239 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7241 struct perf_switch_event
*se
= data
;
7242 struct perf_output_handle handle
;
7243 struct perf_sample_data sample
;
7246 if (!perf_event_switch_match(event
))
7249 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7250 if (event
->ctx
->task
) {
7251 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7252 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7254 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7255 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7256 se
->event_id
.next_prev_pid
=
7257 perf_event_pid(event
, se
->next_prev
);
7258 se
->event_id
.next_prev_tid
=
7259 perf_event_tid(event
, se
->next_prev
);
7262 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7264 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7268 if (event
->ctx
->task
)
7269 perf_output_put(&handle
, se
->event_id
.header
);
7271 perf_output_put(&handle
, se
->event_id
);
7273 perf_event__output_id_sample(event
, &handle
, &sample
);
7275 perf_output_end(&handle
);
7278 static void perf_event_switch(struct task_struct
*task
,
7279 struct task_struct
*next_prev
, bool sched_in
)
7281 struct perf_switch_event switch_event
;
7283 /* N.B. caller checks nr_switch_events != 0 */
7285 switch_event
= (struct perf_switch_event
){
7287 .next_prev
= next_prev
,
7291 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7294 /* .next_prev_pid */
7295 /* .next_prev_tid */
7299 perf_iterate_sb(perf_event_switch_output
,
7305 * IRQ throttle logging
7308 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7310 struct perf_output_handle handle
;
7311 struct perf_sample_data sample
;
7315 struct perf_event_header header
;
7319 } throttle_event
= {
7321 .type
= PERF_RECORD_THROTTLE
,
7323 .size
= sizeof(throttle_event
),
7325 .time
= perf_event_clock(event
),
7326 .id
= primary_event_id(event
),
7327 .stream_id
= event
->id
,
7331 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7333 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7335 ret
= perf_output_begin(&handle
, event
,
7336 throttle_event
.header
.size
);
7340 perf_output_put(&handle
, throttle_event
);
7341 perf_event__output_id_sample(event
, &handle
, &sample
);
7342 perf_output_end(&handle
);
7345 void perf_event_itrace_started(struct perf_event
*event
)
7347 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7350 static void perf_log_itrace_start(struct perf_event
*event
)
7352 struct perf_output_handle handle
;
7353 struct perf_sample_data sample
;
7354 struct perf_aux_event
{
7355 struct perf_event_header header
;
7362 event
= event
->parent
;
7364 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7365 event
->attach_state
& PERF_ATTACH_ITRACE
)
7368 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7369 rec
.header
.misc
= 0;
7370 rec
.header
.size
= sizeof(rec
);
7371 rec
.pid
= perf_event_pid(event
, current
);
7372 rec
.tid
= perf_event_tid(event
, current
);
7374 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7375 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7380 perf_output_put(&handle
, rec
);
7381 perf_event__output_id_sample(event
, &handle
, &sample
);
7383 perf_output_end(&handle
);
7387 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7389 struct hw_perf_event
*hwc
= &event
->hw
;
7393 seq
= __this_cpu_read(perf_throttled_seq
);
7394 if (seq
!= hwc
->interrupts_seq
) {
7395 hwc
->interrupts_seq
= seq
;
7396 hwc
->interrupts
= 1;
7399 if (unlikely(throttle
7400 && hwc
->interrupts
>= max_samples_per_tick
)) {
7401 __this_cpu_inc(perf_throttled_count
);
7402 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7403 hwc
->interrupts
= MAX_INTERRUPTS
;
7404 perf_log_throttle(event
, 0);
7409 if (event
->attr
.freq
) {
7410 u64 now
= perf_clock();
7411 s64 delta
= now
- hwc
->freq_time_stamp
;
7413 hwc
->freq_time_stamp
= now
;
7415 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7416 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7422 int perf_event_account_interrupt(struct perf_event
*event
)
7424 return __perf_event_account_interrupt(event
, 1);
7428 * Generic event overflow handling, sampling.
7431 static int __perf_event_overflow(struct perf_event
*event
,
7432 int throttle
, struct perf_sample_data
*data
,
7433 struct pt_regs
*regs
)
7435 int events
= atomic_read(&event
->event_limit
);
7439 * Non-sampling counters might still use the PMI to fold short
7440 * hardware counters, ignore those.
7442 if (unlikely(!is_sampling_event(event
)))
7445 ret
= __perf_event_account_interrupt(event
, throttle
);
7448 * XXX event_limit might not quite work as expected on inherited
7452 event
->pending_kill
= POLL_IN
;
7453 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7455 event
->pending_kill
= POLL_HUP
;
7457 perf_event_disable_inatomic(event
);
7460 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7462 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7463 event
->pending_wakeup
= 1;
7464 irq_work_queue(&event
->pending
);
7470 int perf_event_overflow(struct perf_event
*event
,
7471 struct perf_sample_data
*data
,
7472 struct pt_regs
*regs
)
7474 return __perf_event_overflow(event
, 1, data
, regs
);
7478 * Generic software event infrastructure
7481 struct swevent_htable
{
7482 struct swevent_hlist
*swevent_hlist
;
7483 struct mutex hlist_mutex
;
7486 /* Recursion avoidance in each contexts */
7487 int recursion
[PERF_NR_CONTEXTS
];
7490 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7493 * We directly increment event->count and keep a second value in
7494 * event->hw.period_left to count intervals. This period event
7495 * is kept in the range [-sample_period, 0] so that we can use the
7499 u64
perf_swevent_set_period(struct perf_event
*event
)
7501 struct hw_perf_event
*hwc
= &event
->hw
;
7502 u64 period
= hwc
->last_period
;
7506 hwc
->last_period
= hwc
->sample_period
;
7509 old
= val
= local64_read(&hwc
->period_left
);
7513 nr
= div64_u64(period
+ val
, period
);
7514 offset
= nr
* period
;
7516 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7522 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7523 struct perf_sample_data
*data
,
7524 struct pt_regs
*regs
)
7526 struct hw_perf_event
*hwc
= &event
->hw
;
7530 overflow
= perf_swevent_set_period(event
);
7532 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7535 for (; overflow
; overflow
--) {
7536 if (__perf_event_overflow(event
, throttle
,
7539 * We inhibit the overflow from happening when
7540 * hwc->interrupts == MAX_INTERRUPTS.
7548 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7549 struct perf_sample_data
*data
,
7550 struct pt_regs
*regs
)
7552 struct hw_perf_event
*hwc
= &event
->hw
;
7554 local64_add(nr
, &event
->count
);
7559 if (!is_sampling_event(event
))
7562 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7564 return perf_swevent_overflow(event
, 1, data
, regs
);
7566 data
->period
= event
->hw
.last_period
;
7568 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7569 return perf_swevent_overflow(event
, 1, data
, regs
);
7571 if (local64_add_negative(nr
, &hwc
->period_left
))
7574 perf_swevent_overflow(event
, 0, data
, regs
);
7577 static int perf_exclude_event(struct perf_event
*event
,
7578 struct pt_regs
*regs
)
7580 if (event
->hw
.state
& PERF_HES_STOPPED
)
7584 if (event
->attr
.exclude_user
&& user_mode(regs
))
7587 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7594 static int perf_swevent_match(struct perf_event
*event
,
7595 enum perf_type_id type
,
7597 struct perf_sample_data
*data
,
7598 struct pt_regs
*regs
)
7600 if (event
->attr
.type
!= type
)
7603 if (event
->attr
.config
!= event_id
)
7606 if (perf_exclude_event(event
, regs
))
7612 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7614 u64 val
= event_id
| (type
<< 32);
7616 return hash_64(val
, SWEVENT_HLIST_BITS
);
7619 static inline struct hlist_head
*
7620 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7622 u64 hash
= swevent_hash(type
, event_id
);
7624 return &hlist
->heads
[hash
];
7627 /* For the read side: events when they trigger */
7628 static inline struct hlist_head
*
7629 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7631 struct swevent_hlist
*hlist
;
7633 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7637 return __find_swevent_head(hlist
, type
, event_id
);
7640 /* For the event head insertion and removal in the hlist */
7641 static inline struct hlist_head
*
7642 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7644 struct swevent_hlist
*hlist
;
7645 u32 event_id
= event
->attr
.config
;
7646 u64 type
= event
->attr
.type
;
7649 * Event scheduling is always serialized against hlist allocation
7650 * and release. Which makes the protected version suitable here.
7651 * The context lock guarantees that.
7653 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7654 lockdep_is_held(&event
->ctx
->lock
));
7658 return __find_swevent_head(hlist
, type
, event_id
);
7661 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7663 struct perf_sample_data
*data
,
7664 struct pt_regs
*regs
)
7666 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7667 struct perf_event
*event
;
7668 struct hlist_head
*head
;
7671 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7675 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7676 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7677 perf_swevent_event(event
, nr
, data
, regs
);
7683 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7685 int perf_swevent_get_recursion_context(void)
7687 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7689 return get_recursion_context(swhash
->recursion
);
7691 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7693 void perf_swevent_put_recursion_context(int rctx
)
7695 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7697 put_recursion_context(swhash
->recursion
, rctx
);
7700 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7702 struct perf_sample_data data
;
7704 if (WARN_ON_ONCE(!regs
))
7707 perf_sample_data_init(&data
, addr
, 0);
7708 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7711 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7715 preempt_disable_notrace();
7716 rctx
= perf_swevent_get_recursion_context();
7717 if (unlikely(rctx
< 0))
7720 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7722 perf_swevent_put_recursion_context(rctx
);
7724 preempt_enable_notrace();
7727 static void perf_swevent_read(struct perf_event
*event
)
7731 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7733 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7734 struct hw_perf_event
*hwc
= &event
->hw
;
7735 struct hlist_head
*head
;
7737 if (is_sampling_event(event
)) {
7738 hwc
->last_period
= hwc
->sample_period
;
7739 perf_swevent_set_period(event
);
7742 hwc
->state
= !(flags
& PERF_EF_START
);
7744 head
= find_swevent_head(swhash
, event
);
7745 if (WARN_ON_ONCE(!head
))
7748 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7749 perf_event_update_userpage(event
);
7754 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7756 hlist_del_rcu(&event
->hlist_entry
);
7759 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7761 event
->hw
.state
= 0;
7764 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7766 event
->hw
.state
= PERF_HES_STOPPED
;
7769 /* Deref the hlist from the update side */
7770 static inline struct swevent_hlist
*
7771 swevent_hlist_deref(struct swevent_htable
*swhash
)
7773 return rcu_dereference_protected(swhash
->swevent_hlist
,
7774 lockdep_is_held(&swhash
->hlist_mutex
));
7777 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7779 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7784 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7785 kfree_rcu(hlist
, rcu_head
);
7788 static void swevent_hlist_put_cpu(int cpu
)
7790 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7792 mutex_lock(&swhash
->hlist_mutex
);
7794 if (!--swhash
->hlist_refcount
)
7795 swevent_hlist_release(swhash
);
7797 mutex_unlock(&swhash
->hlist_mutex
);
7800 static void swevent_hlist_put(void)
7804 for_each_possible_cpu(cpu
)
7805 swevent_hlist_put_cpu(cpu
);
7808 static int swevent_hlist_get_cpu(int cpu
)
7810 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7813 mutex_lock(&swhash
->hlist_mutex
);
7814 if (!swevent_hlist_deref(swhash
) &&
7815 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7816 struct swevent_hlist
*hlist
;
7818 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7823 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7825 swhash
->hlist_refcount
++;
7827 mutex_unlock(&swhash
->hlist_mutex
);
7832 static int swevent_hlist_get(void)
7834 int err
, cpu
, failed_cpu
;
7836 mutex_lock(&pmus_lock
);
7837 for_each_possible_cpu(cpu
) {
7838 err
= swevent_hlist_get_cpu(cpu
);
7844 mutex_unlock(&pmus_lock
);
7847 for_each_possible_cpu(cpu
) {
7848 if (cpu
== failed_cpu
)
7850 swevent_hlist_put_cpu(cpu
);
7852 mutex_unlock(&pmus_lock
);
7856 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7858 static void sw_perf_event_destroy(struct perf_event
*event
)
7860 u64 event_id
= event
->attr
.config
;
7862 WARN_ON(event
->parent
);
7864 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7865 swevent_hlist_put();
7868 static int perf_swevent_init(struct perf_event
*event
)
7870 u64 event_id
= event
->attr
.config
;
7872 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7876 * no branch sampling for software events
7878 if (has_branch_stack(event
))
7882 case PERF_COUNT_SW_CPU_CLOCK
:
7883 case PERF_COUNT_SW_TASK_CLOCK
:
7890 if (event_id
>= PERF_COUNT_SW_MAX
)
7893 if (!event
->parent
) {
7896 err
= swevent_hlist_get();
7900 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7901 event
->destroy
= sw_perf_event_destroy
;
7907 static struct pmu perf_swevent
= {
7908 .task_ctx_nr
= perf_sw_context
,
7910 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7912 .event_init
= perf_swevent_init
,
7913 .add
= perf_swevent_add
,
7914 .del
= perf_swevent_del
,
7915 .start
= perf_swevent_start
,
7916 .stop
= perf_swevent_stop
,
7917 .read
= perf_swevent_read
,
7920 #ifdef CONFIG_EVENT_TRACING
7922 static int perf_tp_filter_match(struct perf_event
*event
,
7923 struct perf_sample_data
*data
)
7925 void *record
= data
->raw
->frag
.data
;
7927 /* only top level events have filters set */
7929 event
= event
->parent
;
7931 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7936 static int perf_tp_event_match(struct perf_event
*event
,
7937 struct perf_sample_data
*data
,
7938 struct pt_regs
*regs
)
7940 if (event
->hw
.state
& PERF_HES_STOPPED
)
7943 * All tracepoints are from kernel-space.
7945 if (event
->attr
.exclude_kernel
)
7948 if (!perf_tp_filter_match(event
, data
))
7954 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7955 struct trace_event_call
*call
, u64 count
,
7956 struct pt_regs
*regs
, struct hlist_head
*head
,
7957 struct task_struct
*task
)
7959 struct bpf_prog
*prog
= call
->prog
;
7962 *(struct pt_regs
**)raw_data
= regs
;
7963 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7964 perf_swevent_put_recursion_context(rctx
);
7968 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7971 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7973 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7974 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7975 struct task_struct
*task
, struct perf_event
*event
)
7977 struct perf_sample_data data
;
7979 struct perf_raw_record raw
= {
7986 perf_sample_data_init(&data
, 0, 0);
7989 perf_trace_buf_update(record
, event_type
);
7991 /* Use the given event instead of the hlist */
7993 if (perf_tp_event_match(event
, &data
, regs
))
7994 perf_swevent_event(event
, count
, &data
, regs
);
7996 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7997 if (perf_tp_event_match(event
, &data
, regs
))
7998 perf_swevent_event(event
, count
, &data
, regs
);
8003 * If we got specified a target task, also iterate its context and
8004 * deliver this event there too.
8006 if (task
&& task
!= current
) {
8007 struct perf_event_context
*ctx
;
8008 struct trace_entry
*entry
= record
;
8011 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
8015 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
8016 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8018 if (event
->attr
.config
!= entry
->type
)
8020 if (perf_tp_event_match(event
, &data
, regs
))
8021 perf_swevent_event(event
, count
, &data
, regs
);
8027 perf_swevent_put_recursion_context(rctx
);
8029 EXPORT_SYMBOL_GPL(perf_tp_event
);
8031 static void tp_perf_event_destroy(struct perf_event
*event
)
8033 perf_trace_destroy(event
);
8036 static int perf_tp_event_init(struct perf_event
*event
)
8040 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8044 * no branch sampling for tracepoint events
8046 if (has_branch_stack(event
))
8049 err
= perf_trace_init(event
);
8053 event
->destroy
= tp_perf_event_destroy
;
8058 static struct pmu perf_tracepoint
= {
8059 .task_ctx_nr
= perf_sw_context
,
8061 .event_init
= perf_tp_event_init
,
8062 .add
= perf_trace_add
,
8063 .del
= perf_trace_del
,
8064 .start
= perf_swevent_start
,
8065 .stop
= perf_swevent_stop
,
8066 .read
= perf_swevent_read
,
8069 static inline void perf_tp_register(void)
8071 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8074 static void perf_event_free_filter(struct perf_event
*event
)
8076 ftrace_profile_free_filter(event
);
8079 #ifdef CONFIG_BPF_SYSCALL
8080 static void bpf_overflow_handler(struct perf_event
*event
,
8081 struct perf_sample_data
*data
,
8082 struct pt_regs
*regs
)
8084 struct bpf_perf_event_data_kern ctx
= {
8091 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8094 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8097 __this_cpu_dec(bpf_prog_active
);
8102 event
->orig_overflow_handler(event
, data
, regs
);
8105 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8107 struct bpf_prog
*prog
;
8109 if (event
->overflow_handler_context
)
8110 /* hw breakpoint or kernel counter */
8116 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8118 return PTR_ERR(prog
);
8121 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8122 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8126 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8128 struct bpf_prog
*prog
= event
->prog
;
8133 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8138 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8142 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8147 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8149 bool is_kprobe
, is_tracepoint
;
8150 struct bpf_prog
*prog
;
8152 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8153 return perf_event_set_bpf_handler(event
, prog_fd
);
8155 if (event
->tp_event
->prog
)
8158 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8159 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8160 if (!is_kprobe
&& !is_tracepoint
)
8161 /* bpf programs can only be attached to u/kprobe or tracepoint */
8164 prog
= bpf_prog_get(prog_fd
);
8166 return PTR_ERR(prog
);
8168 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8169 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8170 /* valid fd, but invalid bpf program type */
8175 if (is_tracepoint
) {
8176 int off
= trace_event_get_offsets(event
->tp_event
);
8178 if (prog
->aux
->max_ctx_offset
> off
) {
8183 event
->tp_event
->prog
= prog
;
8188 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8190 struct bpf_prog
*prog
;
8192 perf_event_free_bpf_handler(event
);
8194 if (!event
->tp_event
)
8197 prog
= event
->tp_event
->prog
;
8199 event
->tp_event
->prog
= NULL
;
8206 static inline void perf_tp_register(void)
8210 static void perf_event_free_filter(struct perf_event
*event
)
8214 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8219 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8222 #endif /* CONFIG_EVENT_TRACING */
8224 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8225 void perf_bp_event(struct perf_event
*bp
, void *data
)
8227 struct perf_sample_data sample
;
8228 struct pt_regs
*regs
= data
;
8230 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8232 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8233 perf_swevent_event(bp
, 1, &sample
, regs
);
8238 * Allocate a new address filter
8240 static struct perf_addr_filter
*
8241 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8243 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8244 struct perf_addr_filter
*filter
;
8246 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8250 INIT_LIST_HEAD(&filter
->entry
);
8251 list_add_tail(&filter
->entry
, filters
);
8256 static void free_filters_list(struct list_head
*filters
)
8258 struct perf_addr_filter
*filter
, *iter
;
8260 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8262 iput(filter
->inode
);
8263 list_del(&filter
->entry
);
8269 * Free existing address filters and optionally install new ones
8271 static void perf_addr_filters_splice(struct perf_event
*event
,
8272 struct list_head
*head
)
8274 unsigned long flags
;
8277 if (!has_addr_filter(event
))
8280 /* don't bother with children, they don't have their own filters */
8284 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8286 list_splice_init(&event
->addr_filters
.list
, &list
);
8288 list_splice(head
, &event
->addr_filters
.list
);
8290 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8292 free_filters_list(&list
);
8296 * Scan through mm's vmas and see if one of them matches the
8297 * @filter; if so, adjust filter's address range.
8298 * Called with mm::mmap_sem down for reading.
8300 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8301 struct mm_struct
*mm
)
8303 struct vm_area_struct
*vma
;
8305 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8306 struct file
*file
= vma
->vm_file
;
8307 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8308 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8313 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8316 return vma
->vm_start
;
8323 * Update event's address range filters based on the
8324 * task's existing mappings, if any.
8326 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8328 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8329 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8330 struct perf_addr_filter
*filter
;
8331 struct mm_struct
*mm
= NULL
;
8332 unsigned int count
= 0;
8333 unsigned long flags
;
8336 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8337 * will stop on the parent's child_mutex that our caller is also holding
8339 if (task
== TASK_TOMBSTONE
)
8342 if (!ifh
->nr_file_filters
)
8345 mm
= get_task_mm(event
->ctx
->task
);
8349 down_read(&mm
->mmap_sem
);
8351 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8352 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8353 event
->addr_filters_offs
[count
] = 0;
8356 * Adjust base offset if the filter is associated to a binary
8357 * that needs to be mapped:
8360 event
->addr_filters_offs
[count
] =
8361 perf_addr_filter_apply(filter
, mm
);
8366 event
->addr_filters_gen
++;
8367 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8369 up_read(&mm
->mmap_sem
);
8374 perf_event_stop(event
, 1);
8378 * Address range filtering: limiting the data to certain
8379 * instruction address ranges. Filters are ioctl()ed to us from
8380 * userspace as ascii strings.
8382 * Filter string format:
8385 * where ACTION is one of the
8386 * * "filter": limit the trace to this region
8387 * * "start": start tracing from this address
8388 * * "stop": stop tracing at this address/region;
8390 * * for kernel addresses: <start address>[/<size>]
8391 * * for object files: <start address>[/<size>]@</path/to/object/file>
8393 * if <size> is not specified, the range is treated as a single address.
8407 IF_STATE_ACTION
= 0,
8412 static const match_table_t if_tokens
= {
8413 { IF_ACT_FILTER
, "filter" },
8414 { IF_ACT_START
, "start" },
8415 { IF_ACT_STOP
, "stop" },
8416 { IF_SRC_FILE
, "%u/%u@%s" },
8417 { IF_SRC_KERNEL
, "%u/%u" },
8418 { IF_SRC_FILEADDR
, "%u@%s" },
8419 { IF_SRC_KERNELADDR
, "%u" },
8420 { IF_ACT_NONE
, NULL
},
8424 * Address filter string parser
8427 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8428 struct list_head
*filters
)
8430 struct perf_addr_filter
*filter
= NULL
;
8431 char *start
, *orig
, *filename
= NULL
;
8433 substring_t args
[MAX_OPT_ARGS
];
8434 int state
= IF_STATE_ACTION
, token
;
8435 unsigned int kernel
= 0;
8438 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8442 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8448 /* filter definition begins */
8449 if (state
== IF_STATE_ACTION
) {
8450 filter
= perf_addr_filter_new(event
, filters
);
8455 token
= match_token(start
, if_tokens
, args
);
8462 if (state
!= IF_STATE_ACTION
)
8465 state
= IF_STATE_SOURCE
;
8468 case IF_SRC_KERNELADDR
:
8472 case IF_SRC_FILEADDR
:
8474 if (state
!= IF_STATE_SOURCE
)
8477 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8481 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8485 if (filter
->range
) {
8487 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8492 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8493 int fpos
= filter
->range
? 2 : 1;
8495 filename
= match_strdup(&args
[fpos
]);
8502 state
= IF_STATE_END
;
8510 * Filter definition is fully parsed, validate and install it.
8511 * Make sure that it doesn't contradict itself or the event's
8514 if (state
== IF_STATE_END
) {
8516 if (kernel
&& event
->attr
.exclude_kernel
)
8524 * For now, we only support file-based filters
8525 * in per-task events; doing so for CPU-wide
8526 * events requires additional context switching
8527 * trickery, since same object code will be
8528 * mapped at different virtual addresses in
8529 * different processes.
8532 if (!event
->ctx
->task
)
8533 goto fail_free_name
;
8535 /* look up the path and grab its inode */
8536 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8538 goto fail_free_name
;
8540 filter
->inode
= igrab(d_inode(path
.dentry
));
8546 if (!filter
->inode
||
8547 !S_ISREG(filter
->inode
->i_mode
))
8548 /* free_filters_list() will iput() */
8551 event
->addr_filters
.nr_file_filters
++;
8554 /* ready to consume more filters */
8555 state
= IF_STATE_ACTION
;
8560 if (state
!= IF_STATE_ACTION
)
8570 free_filters_list(filters
);
8577 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8583 * Since this is called in perf_ioctl() path, we're already holding
8586 lockdep_assert_held(&event
->ctx
->mutex
);
8588 if (WARN_ON_ONCE(event
->parent
))
8591 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8593 goto fail_clear_files
;
8595 ret
= event
->pmu
->addr_filters_validate(&filters
);
8597 goto fail_free_filters
;
8599 /* remove existing filters, if any */
8600 perf_addr_filters_splice(event
, &filters
);
8602 /* install new filters */
8603 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8608 free_filters_list(&filters
);
8611 event
->addr_filters
.nr_file_filters
= 0;
8616 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8621 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8622 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8623 !has_addr_filter(event
))
8626 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8627 if (IS_ERR(filter_str
))
8628 return PTR_ERR(filter_str
);
8630 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8631 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8632 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8634 else if (has_addr_filter(event
))
8635 ret
= perf_event_set_addr_filter(event
, filter_str
);
8642 * hrtimer based swevent callback
8645 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8647 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8648 struct perf_sample_data data
;
8649 struct pt_regs
*regs
;
8650 struct perf_event
*event
;
8653 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8655 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8656 return HRTIMER_NORESTART
;
8658 event
->pmu
->read(event
);
8660 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8661 regs
= get_irq_regs();
8663 if (regs
&& !perf_exclude_event(event
, regs
)) {
8664 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8665 if (__perf_event_overflow(event
, 1, &data
, regs
))
8666 ret
= HRTIMER_NORESTART
;
8669 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8670 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8675 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8677 struct hw_perf_event
*hwc
= &event
->hw
;
8680 if (!is_sampling_event(event
))
8683 period
= local64_read(&hwc
->period_left
);
8688 local64_set(&hwc
->period_left
, 0);
8690 period
= max_t(u64
, 10000, hwc
->sample_period
);
8692 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8693 HRTIMER_MODE_REL_PINNED
);
8696 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8698 struct hw_perf_event
*hwc
= &event
->hw
;
8700 if (is_sampling_event(event
)) {
8701 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8702 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8704 hrtimer_cancel(&hwc
->hrtimer
);
8708 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8710 struct hw_perf_event
*hwc
= &event
->hw
;
8712 if (!is_sampling_event(event
))
8715 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8716 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8719 * Since hrtimers have a fixed rate, we can do a static freq->period
8720 * mapping and avoid the whole period adjust feedback stuff.
8722 if (event
->attr
.freq
) {
8723 long freq
= event
->attr
.sample_freq
;
8725 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8726 hwc
->sample_period
= event
->attr
.sample_period
;
8727 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8728 hwc
->last_period
= hwc
->sample_period
;
8729 event
->attr
.freq
= 0;
8734 * Software event: cpu wall time clock
8737 static void cpu_clock_event_update(struct perf_event
*event
)
8742 now
= local_clock();
8743 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8744 local64_add(now
- prev
, &event
->count
);
8747 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8749 local64_set(&event
->hw
.prev_count
, local_clock());
8750 perf_swevent_start_hrtimer(event
);
8753 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8755 perf_swevent_cancel_hrtimer(event
);
8756 cpu_clock_event_update(event
);
8759 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8761 if (flags
& PERF_EF_START
)
8762 cpu_clock_event_start(event
, flags
);
8763 perf_event_update_userpage(event
);
8768 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8770 cpu_clock_event_stop(event
, flags
);
8773 static void cpu_clock_event_read(struct perf_event
*event
)
8775 cpu_clock_event_update(event
);
8778 static int cpu_clock_event_init(struct perf_event
*event
)
8780 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8783 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8787 * no branch sampling for software events
8789 if (has_branch_stack(event
))
8792 perf_swevent_init_hrtimer(event
);
8797 static struct pmu perf_cpu_clock
= {
8798 .task_ctx_nr
= perf_sw_context
,
8800 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8802 .event_init
= cpu_clock_event_init
,
8803 .add
= cpu_clock_event_add
,
8804 .del
= cpu_clock_event_del
,
8805 .start
= cpu_clock_event_start
,
8806 .stop
= cpu_clock_event_stop
,
8807 .read
= cpu_clock_event_read
,
8811 * Software event: task time clock
8814 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8819 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8821 local64_add(delta
, &event
->count
);
8824 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8826 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8827 perf_swevent_start_hrtimer(event
);
8830 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8832 perf_swevent_cancel_hrtimer(event
);
8833 task_clock_event_update(event
, event
->ctx
->time
);
8836 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8838 if (flags
& PERF_EF_START
)
8839 task_clock_event_start(event
, flags
);
8840 perf_event_update_userpage(event
);
8845 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8847 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8850 static void task_clock_event_read(struct perf_event
*event
)
8852 u64 now
= perf_clock();
8853 u64 delta
= now
- event
->ctx
->timestamp
;
8854 u64 time
= event
->ctx
->time
+ delta
;
8856 task_clock_event_update(event
, time
);
8859 static int task_clock_event_init(struct perf_event
*event
)
8861 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8864 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8868 * no branch sampling for software events
8870 if (has_branch_stack(event
))
8873 perf_swevent_init_hrtimer(event
);
8878 static struct pmu perf_task_clock
= {
8879 .task_ctx_nr
= perf_sw_context
,
8881 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8883 .event_init
= task_clock_event_init
,
8884 .add
= task_clock_event_add
,
8885 .del
= task_clock_event_del
,
8886 .start
= task_clock_event_start
,
8887 .stop
= task_clock_event_stop
,
8888 .read
= task_clock_event_read
,
8891 static void perf_pmu_nop_void(struct pmu
*pmu
)
8895 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8899 static int perf_pmu_nop_int(struct pmu
*pmu
)
8904 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8906 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8908 __this_cpu_write(nop_txn_flags
, flags
);
8910 if (flags
& ~PERF_PMU_TXN_ADD
)
8913 perf_pmu_disable(pmu
);
8916 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8918 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8920 __this_cpu_write(nop_txn_flags
, 0);
8922 if (flags
& ~PERF_PMU_TXN_ADD
)
8925 perf_pmu_enable(pmu
);
8929 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8931 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8933 __this_cpu_write(nop_txn_flags
, 0);
8935 if (flags
& ~PERF_PMU_TXN_ADD
)
8938 perf_pmu_enable(pmu
);
8941 static int perf_event_idx_default(struct perf_event
*event
)
8947 * Ensures all contexts with the same task_ctx_nr have the same
8948 * pmu_cpu_context too.
8950 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8957 list_for_each_entry(pmu
, &pmus
, entry
) {
8958 if (pmu
->task_ctx_nr
== ctxn
)
8959 return pmu
->pmu_cpu_context
;
8965 static void free_pmu_context(struct pmu
*pmu
)
8967 mutex_lock(&pmus_lock
);
8968 free_percpu(pmu
->pmu_cpu_context
);
8969 mutex_unlock(&pmus_lock
);
8973 * Let userspace know that this PMU supports address range filtering:
8975 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8976 struct device_attribute
*attr
,
8979 struct pmu
*pmu
= dev_get_drvdata(dev
);
8981 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8983 DEVICE_ATTR_RO(nr_addr_filters
);
8985 static struct idr pmu_idr
;
8988 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8990 struct pmu
*pmu
= dev_get_drvdata(dev
);
8992 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8994 static DEVICE_ATTR_RO(type
);
8997 perf_event_mux_interval_ms_show(struct device
*dev
,
8998 struct device_attribute
*attr
,
9001 struct pmu
*pmu
= dev_get_drvdata(dev
);
9003 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
9006 static DEFINE_MUTEX(mux_interval_mutex
);
9009 perf_event_mux_interval_ms_store(struct device
*dev
,
9010 struct device_attribute
*attr
,
9011 const char *buf
, size_t count
)
9013 struct pmu
*pmu
= dev_get_drvdata(dev
);
9014 int timer
, cpu
, ret
;
9016 ret
= kstrtoint(buf
, 0, &timer
);
9023 /* same value, noting to do */
9024 if (timer
== pmu
->hrtimer_interval_ms
)
9027 mutex_lock(&mux_interval_mutex
);
9028 pmu
->hrtimer_interval_ms
= timer
;
9030 /* update all cpuctx for this PMU */
9032 for_each_online_cpu(cpu
) {
9033 struct perf_cpu_context
*cpuctx
;
9034 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9035 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
9037 cpu_function_call(cpu
,
9038 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
9041 mutex_unlock(&mux_interval_mutex
);
9045 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
9047 static struct attribute
*pmu_dev_attrs
[] = {
9048 &dev_attr_type
.attr
,
9049 &dev_attr_perf_event_mux_interval_ms
.attr
,
9052 ATTRIBUTE_GROUPS(pmu_dev
);
9054 static int pmu_bus_running
;
9055 static struct bus_type pmu_bus
= {
9056 .name
= "event_source",
9057 .dev_groups
= pmu_dev_groups
,
9060 static void pmu_dev_release(struct device
*dev
)
9065 static int pmu_dev_alloc(struct pmu
*pmu
)
9069 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9073 pmu
->dev
->groups
= pmu
->attr_groups
;
9074 device_initialize(pmu
->dev
);
9075 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9079 dev_set_drvdata(pmu
->dev
, pmu
);
9080 pmu
->dev
->bus
= &pmu_bus
;
9081 pmu
->dev
->release
= pmu_dev_release
;
9082 ret
= device_add(pmu
->dev
);
9086 /* For PMUs with address filters, throw in an extra attribute: */
9087 if (pmu
->nr_addr_filters
)
9088 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9097 device_del(pmu
->dev
);
9100 put_device(pmu
->dev
);
9104 static struct lock_class_key cpuctx_mutex
;
9105 static struct lock_class_key cpuctx_lock
;
9107 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9111 mutex_lock(&pmus_lock
);
9113 pmu
->pmu_disable_count
= alloc_percpu(int);
9114 if (!pmu
->pmu_disable_count
)
9123 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9131 if (pmu_bus_running
) {
9132 ret
= pmu_dev_alloc(pmu
);
9138 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9139 static int hw_context_taken
= 0;
9142 * Other than systems with heterogeneous CPUs, it never makes
9143 * sense for two PMUs to share perf_hw_context. PMUs which are
9144 * uncore must use perf_invalid_context.
9146 if (WARN_ON_ONCE(hw_context_taken
&&
9147 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9148 pmu
->task_ctx_nr
= perf_invalid_context
;
9150 hw_context_taken
= 1;
9153 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9154 if (pmu
->pmu_cpu_context
)
9155 goto got_cpu_context
;
9158 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9159 if (!pmu
->pmu_cpu_context
)
9162 for_each_possible_cpu(cpu
) {
9163 struct perf_cpu_context
*cpuctx
;
9165 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9166 __perf_event_init_context(&cpuctx
->ctx
);
9167 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9168 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9169 cpuctx
->ctx
.pmu
= pmu
;
9170 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9172 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9176 if (!pmu
->start_txn
) {
9177 if (pmu
->pmu_enable
) {
9179 * If we have pmu_enable/pmu_disable calls, install
9180 * transaction stubs that use that to try and batch
9181 * hardware accesses.
9183 pmu
->start_txn
= perf_pmu_start_txn
;
9184 pmu
->commit_txn
= perf_pmu_commit_txn
;
9185 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9187 pmu
->start_txn
= perf_pmu_nop_txn
;
9188 pmu
->commit_txn
= perf_pmu_nop_int
;
9189 pmu
->cancel_txn
= perf_pmu_nop_void
;
9193 if (!pmu
->pmu_enable
) {
9194 pmu
->pmu_enable
= perf_pmu_nop_void
;
9195 pmu
->pmu_disable
= perf_pmu_nop_void
;
9198 if (!pmu
->event_idx
)
9199 pmu
->event_idx
= perf_event_idx_default
;
9201 list_add_rcu(&pmu
->entry
, &pmus
);
9202 atomic_set(&pmu
->exclusive_cnt
, 0);
9205 mutex_unlock(&pmus_lock
);
9210 device_del(pmu
->dev
);
9211 put_device(pmu
->dev
);
9214 if (pmu
->type
>= PERF_TYPE_MAX
)
9215 idr_remove(&pmu_idr
, pmu
->type
);
9218 free_percpu(pmu
->pmu_disable_count
);
9221 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9223 void perf_pmu_unregister(struct pmu
*pmu
)
9227 mutex_lock(&pmus_lock
);
9228 remove_device
= pmu_bus_running
;
9229 list_del_rcu(&pmu
->entry
);
9230 mutex_unlock(&pmus_lock
);
9233 * We dereference the pmu list under both SRCU and regular RCU, so
9234 * synchronize against both of those.
9236 synchronize_srcu(&pmus_srcu
);
9239 free_percpu(pmu
->pmu_disable_count
);
9240 if (pmu
->type
>= PERF_TYPE_MAX
)
9241 idr_remove(&pmu_idr
, pmu
->type
);
9242 if (remove_device
) {
9243 if (pmu
->nr_addr_filters
)
9244 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9245 device_del(pmu
->dev
);
9246 put_device(pmu
->dev
);
9248 free_pmu_context(pmu
);
9250 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9252 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9254 struct perf_event_context
*ctx
= NULL
;
9257 if (!try_module_get(pmu
->module
))
9260 if (event
->group_leader
!= event
) {
9262 * This ctx->mutex can nest when we're called through
9263 * inheritance. See the perf_event_ctx_lock_nested() comment.
9265 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9266 SINGLE_DEPTH_NESTING
);
9271 ret
= pmu
->event_init(event
);
9274 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9277 module_put(pmu
->module
);
9282 static struct pmu
*perf_init_event(struct perf_event
*event
)
9288 idx
= srcu_read_lock(&pmus_srcu
);
9290 /* Try parent's PMU first: */
9291 if (event
->parent
&& event
->parent
->pmu
) {
9292 pmu
= event
->parent
->pmu
;
9293 ret
= perf_try_init_event(pmu
, event
);
9299 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9302 ret
= perf_try_init_event(pmu
, event
);
9308 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9309 ret
= perf_try_init_event(pmu
, event
);
9313 if (ret
!= -ENOENT
) {
9318 pmu
= ERR_PTR(-ENOENT
);
9320 srcu_read_unlock(&pmus_srcu
, idx
);
9325 static void attach_sb_event(struct perf_event
*event
)
9327 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9329 raw_spin_lock(&pel
->lock
);
9330 list_add_rcu(&event
->sb_list
, &pel
->list
);
9331 raw_spin_unlock(&pel
->lock
);
9335 * We keep a list of all !task (and therefore per-cpu) events
9336 * that need to receive side-band records.
9338 * This avoids having to scan all the various PMU per-cpu contexts
9341 static void account_pmu_sb_event(struct perf_event
*event
)
9343 if (is_sb_event(event
))
9344 attach_sb_event(event
);
9347 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9352 if (is_cgroup_event(event
))
9353 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9356 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9357 static void account_freq_event_nohz(void)
9359 #ifdef CONFIG_NO_HZ_FULL
9360 /* Lock so we don't race with concurrent unaccount */
9361 spin_lock(&nr_freq_lock
);
9362 if (atomic_inc_return(&nr_freq_events
) == 1)
9363 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9364 spin_unlock(&nr_freq_lock
);
9368 static void account_freq_event(void)
9370 if (tick_nohz_full_enabled())
9371 account_freq_event_nohz();
9373 atomic_inc(&nr_freq_events
);
9377 static void account_event(struct perf_event
*event
)
9384 if (event
->attach_state
& PERF_ATTACH_TASK
)
9386 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9387 atomic_inc(&nr_mmap_events
);
9388 if (event
->attr
.comm
)
9389 atomic_inc(&nr_comm_events
);
9390 if (event
->attr
.namespaces
)
9391 atomic_inc(&nr_namespaces_events
);
9392 if (event
->attr
.task
)
9393 atomic_inc(&nr_task_events
);
9394 if (event
->attr
.freq
)
9395 account_freq_event();
9396 if (event
->attr
.context_switch
) {
9397 atomic_inc(&nr_switch_events
);
9400 if (has_branch_stack(event
))
9402 if (is_cgroup_event(event
))
9406 if (atomic_inc_not_zero(&perf_sched_count
))
9409 mutex_lock(&perf_sched_mutex
);
9410 if (!atomic_read(&perf_sched_count
)) {
9411 static_branch_enable(&perf_sched_events
);
9413 * Guarantee that all CPUs observe they key change and
9414 * call the perf scheduling hooks before proceeding to
9415 * install events that need them.
9417 synchronize_sched();
9420 * Now that we have waited for the sync_sched(), allow further
9421 * increments to by-pass the mutex.
9423 atomic_inc(&perf_sched_count
);
9424 mutex_unlock(&perf_sched_mutex
);
9428 account_event_cpu(event
, event
->cpu
);
9430 account_pmu_sb_event(event
);
9434 * Allocate and initialize a event structure
9436 static struct perf_event
*
9437 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9438 struct task_struct
*task
,
9439 struct perf_event
*group_leader
,
9440 struct perf_event
*parent_event
,
9441 perf_overflow_handler_t overflow_handler
,
9442 void *context
, int cgroup_fd
)
9445 struct perf_event
*event
;
9446 struct hw_perf_event
*hwc
;
9449 if ((unsigned)cpu
>= nr_cpu_ids
) {
9450 if (!task
|| cpu
!= -1)
9451 return ERR_PTR(-EINVAL
);
9454 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9456 return ERR_PTR(-ENOMEM
);
9459 * Single events are their own group leaders, with an
9460 * empty sibling list:
9463 group_leader
= event
;
9465 mutex_init(&event
->child_mutex
);
9466 INIT_LIST_HEAD(&event
->child_list
);
9468 INIT_LIST_HEAD(&event
->group_entry
);
9469 INIT_LIST_HEAD(&event
->event_entry
);
9470 INIT_LIST_HEAD(&event
->sibling_list
);
9471 INIT_LIST_HEAD(&event
->rb_entry
);
9472 INIT_LIST_HEAD(&event
->active_entry
);
9473 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9474 INIT_HLIST_NODE(&event
->hlist_entry
);
9477 init_waitqueue_head(&event
->waitq
);
9478 init_irq_work(&event
->pending
, perf_pending_event
);
9480 mutex_init(&event
->mmap_mutex
);
9481 raw_spin_lock_init(&event
->addr_filters
.lock
);
9483 atomic_long_set(&event
->refcount
, 1);
9485 event
->attr
= *attr
;
9486 event
->group_leader
= group_leader
;
9490 event
->parent
= parent_event
;
9492 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9493 event
->id
= atomic64_inc_return(&perf_event_id
);
9495 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9498 event
->attach_state
= PERF_ATTACH_TASK
;
9500 * XXX pmu::event_init needs to know what task to account to
9501 * and we cannot use the ctx information because we need the
9502 * pmu before we get a ctx.
9504 event
->hw
.target
= task
;
9507 event
->clock
= &local_clock
;
9509 event
->clock
= parent_event
->clock
;
9511 if (!overflow_handler
&& parent_event
) {
9512 overflow_handler
= parent_event
->overflow_handler
;
9513 context
= parent_event
->overflow_handler_context
;
9514 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9515 if (overflow_handler
== bpf_overflow_handler
) {
9516 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9519 err
= PTR_ERR(prog
);
9523 event
->orig_overflow_handler
=
9524 parent_event
->orig_overflow_handler
;
9529 if (overflow_handler
) {
9530 event
->overflow_handler
= overflow_handler
;
9531 event
->overflow_handler_context
= context
;
9532 } else if (is_write_backward(event
)){
9533 event
->overflow_handler
= perf_event_output_backward
;
9534 event
->overflow_handler_context
= NULL
;
9536 event
->overflow_handler
= perf_event_output_forward
;
9537 event
->overflow_handler_context
= NULL
;
9540 perf_event__state_init(event
);
9545 hwc
->sample_period
= attr
->sample_period
;
9546 if (attr
->freq
&& attr
->sample_freq
)
9547 hwc
->sample_period
= 1;
9548 hwc
->last_period
= hwc
->sample_period
;
9550 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9553 * We currently do not support PERF_SAMPLE_READ on inherited events.
9554 * See perf_output_read().
9556 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9559 if (!has_branch_stack(event
))
9560 event
->attr
.branch_sample_type
= 0;
9562 if (cgroup_fd
!= -1) {
9563 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9568 pmu
= perf_init_event(event
);
9574 err
= exclusive_event_init(event
);
9578 if (has_addr_filter(event
)) {
9579 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9580 sizeof(unsigned long),
9582 if (!event
->addr_filters_offs
) {
9587 /* force hw sync on the address filters */
9588 event
->addr_filters_gen
= 1;
9591 if (!event
->parent
) {
9592 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9593 err
= get_callchain_buffers(attr
->sample_max_stack
);
9595 goto err_addr_filters
;
9599 /* symmetric to unaccount_event() in _free_event() */
9600 account_event(event
);
9605 kfree(event
->addr_filters_offs
);
9608 exclusive_event_destroy(event
);
9612 event
->destroy(event
);
9613 module_put(pmu
->module
);
9615 if (is_cgroup_event(event
))
9616 perf_detach_cgroup(event
);
9618 put_pid_ns(event
->ns
);
9621 return ERR_PTR(err
);
9624 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9625 struct perf_event_attr
*attr
)
9630 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9634 * zero the full structure, so that a short copy will be nice.
9636 memset(attr
, 0, sizeof(*attr
));
9638 ret
= get_user(size
, &uattr
->size
);
9642 if (size
> PAGE_SIZE
) /* silly large */
9645 if (!size
) /* abi compat */
9646 size
= PERF_ATTR_SIZE_VER0
;
9648 if (size
< PERF_ATTR_SIZE_VER0
)
9652 * If we're handed a bigger struct than we know of,
9653 * ensure all the unknown bits are 0 - i.e. new
9654 * user-space does not rely on any kernel feature
9655 * extensions we dont know about yet.
9657 if (size
> sizeof(*attr
)) {
9658 unsigned char __user
*addr
;
9659 unsigned char __user
*end
;
9662 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9663 end
= (void __user
*)uattr
+ size
;
9665 for (; addr
< end
; addr
++) {
9666 ret
= get_user(val
, addr
);
9672 size
= sizeof(*attr
);
9675 ret
= copy_from_user(attr
, uattr
, size
);
9681 if (attr
->__reserved_1
)
9684 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9687 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9690 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9691 u64 mask
= attr
->branch_sample_type
;
9693 /* only using defined bits */
9694 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9697 /* at least one branch bit must be set */
9698 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9701 /* propagate priv level, when not set for branch */
9702 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9704 /* exclude_kernel checked on syscall entry */
9705 if (!attr
->exclude_kernel
)
9706 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9708 if (!attr
->exclude_user
)
9709 mask
|= PERF_SAMPLE_BRANCH_USER
;
9711 if (!attr
->exclude_hv
)
9712 mask
|= PERF_SAMPLE_BRANCH_HV
;
9714 * adjust user setting (for HW filter setup)
9716 attr
->branch_sample_type
= mask
;
9718 /* privileged levels capture (kernel, hv): check permissions */
9719 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9720 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9724 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9725 ret
= perf_reg_validate(attr
->sample_regs_user
);
9730 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9731 if (!arch_perf_have_user_stack_dump())
9735 * We have __u32 type for the size, but so far
9736 * we can only use __u16 as maximum due to the
9737 * __u16 sample size limit.
9739 if (attr
->sample_stack_user
>= USHRT_MAX
)
9741 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9745 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9746 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9751 put_user(sizeof(*attr
), &uattr
->size
);
9757 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9759 struct ring_buffer
*rb
= NULL
;
9765 /* don't allow circular references */
9766 if (event
== output_event
)
9770 * Don't allow cross-cpu buffers
9772 if (output_event
->cpu
!= event
->cpu
)
9776 * If its not a per-cpu rb, it must be the same task.
9778 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9782 * Mixing clocks in the same buffer is trouble you don't need.
9784 if (output_event
->clock
!= event
->clock
)
9788 * Either writing ring buffer from beginning or from end.
9789 * Mixing is not allowed.
9791 if (is_write_backward(output_event
) != is_write_backward(event
))
9795 * If both events generate aux data, they must be on the same PMU
9797 if (has_aux(event
) && has_aux(output_event
) &&
9798 event
->pmu
!= output_event
->pmu
)
9802 mutex_lock(&event
->mmap_mutex
);
9803 /* Can't redirect output if we've got an active mmap() */
9804 if (atomic_read(&event
->mmap_count
))
9808 /* get the rb we want to redirect to */
9809 rb
= ring_buffer_get(output_event
);
9814 ring_buffer_attach(event
, rb
);
9818 mutex_unlock(&event
->mmap_mutex
);
9824 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9830 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9833 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9835 bool nmi_safe
= false;
9838 case CLOCK_MONOTONIC
:
9839 event
->clock
= &ktime_get_mono_fast_ns
;
9843 case CLOCK_MONOTONIC_RAW
:
9844 event
->clock
= &ktime_get_raw_fast_ns
;
9848 case CLOCK_REALTIME
:
9849 event
->clock
= &ktime_get_real_ns
;
9852 case CLOCK_BOOTTIME
:
9853 event
->clock
= &ktime_get_boot_ns
;
9857 event
->clock
= &ktime_get_tai_ns
;
9864 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9871 * Variation on perf_event_ctx_lock_nested(), except we take two context
9874 static struct perf_event_context
*
9875 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9876 struct perf_event_context
*ctx
)
9878 struct perf_event_context
*gctx
;
9882 gctx
= READ_ONCE(group_leader
->ctx
);
9883 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9889 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9891 if (group_leader
->ctx
!= gctx
) {
9892 mutex_unlock(&ctx
->mutex
);
9893 mutex_unlock(&gctx
->mutex
);
9902 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9904 * @attr_uptr: event_id type attributes for monitoring/sampling
9907 * @group_fd: group leader event fd
9909 SYSCALL_DEFINE5(perf_event_open
,
9910 struct perf_event_attr __user
*, attr_uptr
,
9911 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9913 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9914 struct perf_event
*event
, *sibling
;
9915 struct perf_event_attr attr
;
9916 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9917 struct file
*event_file
= NULL
;
9918 struct fd group
= {NULL
, 0};
9919 struct task_struct
*task
= NULL
;
9924 int f_flags
= O_RDWR
;
9927 /* for future expandability... */
9928 if (flags
& ~PERF_FLAG_ALL
)
9931 err
= perf_copy_attr(attr_uptr
, &attr
);
9935 if (!attr
.exclude_kernel
) {
9936 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9940 if (attr
.namespaces
) {
9941 if (!capable(CAP_SYS_ADMIN
))
9946 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9949 if (attr
.sample_period
& (1ULL << 63))
9953 /* Only privileged users can get physical addresses */
9954 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
9955 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9958 if (!attr
.sample_max_stack
)
9959 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9962 * In cgroup mode, the pid argument is used to pass the fd
9963 * opened to the cgroup directory in cgroupfs. The cpu argument
9964 * designates the cpu on which to monitor threads from that
9967 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9970 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9971 f_flags
|= O_CLOEXEC
;
9973 event_fd
= get_unused_fd_flags(f_flags
);
9977 if (group_fd
!= -1) {
9978 err
= perf_fget_light(group_fd
, &group
);
9981 group_leader
= group
.file
->private_data
;
9982 if (flags
& PERF_FLAG_FD_OUTPUT
)
9983 output_event
= group_leader
;
9984 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9985 group_leader
= NULL
;
9988 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9989 task
= find_lively_task_by_vpid(pid
);
9991 err
= PTR_ERR(task
);
9996 if (task
&& group_leader
&&
9997 group_leader
->attr
.inherit
!= attr
.inherit
) {
10003 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
10008 * Reuse ptrace permission checks for now.
10010 * We must hold cred_guard_mutex across this and any potential
10011 * perf_install_in_context() call for this new event to
10012 * serialize against exec() altering our credentials (and the
10013 * perf_event_exit_task() that could imply).
10016 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
10020 if (flags
& PERF_FLAG_PID_CGROUP
)
10023 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
10024 NULL
, NULL
, cgroup_fd
);
10025 if (IS_ERR(event
)) {
10026 err
= PTR_ERR(event
);
10030 if (is_sampling_event(event
)) {
10031 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
10038 * Special case software events and allow them to be part of
10039 * any hardware group.
10043 if (attr
.use_clockid
) {
10044 err
= perf_event_set_clock(event
, attr
.clockid
);
10049 if (pmu
->task_ctx_nr
== perf_sw_context
)
10050 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
10052 if (group_leader
&&
10053 (is_software_event(event
) != is_software_event(group_leader
))) {
10054 if (is_software_event(event
)) {
10056 * If event and group_leader are not both a software
10057 * event, and event is, then group leader is not.
10059 * Allow the addition of software events to !software
10060 * groups, this is safe because software events never
10061 * fail to schedule.
10063 pmu
= group_leader
->pmu
;
10064 } else if (is_software_event(group_leader
) &&
10065 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10067 * In case the group is a pure software group, and we
10068 * try to add a hardware event, move the whole group to
10069 * the hardware context.
10076 * Get the target context (task or percpu):
10078 ctx
= find_get_context(pmu
, task
, event
);
10080 err
= PTR_ERR(ctx
);
10084 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10090 * Look up the group leader (we will attach this event to it):
10092 if (group_leader
) {
10096 * Do not allow a recursive hierarchy (this new sibling
10097 * becoming part of another group-sibling):
10099 if (group_leader
->group_leader
!= group_leader
)
10102 /* All events in a group should have the same clock */
10103 if (group_leader
->clock
!= event
->clock
)
10107 * Make sure we're both events for the same CPU;
10108 * grouping events for different CPUs is broken; since
10109 * you can never concurrently schedule them anyhow.
10111 if (group_leader
->cpu
!= event
->cpu
)
10115 * Make sure we're both on the same task, or both
10118 if (group_leader
->ctx
->task
!= ctx
->task
)
10122 * Do not allow to attach to a group in a different task
10123 * or CPU context. If we're moving SW events, we'll fix
10124 * this up later, so allow that.
10126 if (!move_group
&& group_leader
->ctx
!= ctx
)
10130 * Only a group leader can be exclusive or pinned
10132 if (attr
.exclusive
|| attr
.pinned
)
10136 if (output_event
) {
10137 err
= perf_event_set_output(event
, output_event
);
10142 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10144 if (IS_ERR(event_file
)) {
10145 err
= PTR_ERR(event_file
);
10151 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10153 if (gctx
->task
== TASK_TOMBSTONE
) {
10159 * Check if we raced against another sys_perf_event_open() call
10160 * moving the software group underneath us.
10162 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10164 * If someone moved the group out from under us, check
10165 * if this new event wound up on the same ctx, if so
10166 * its the regular !move_group case, otherwise fail.
10172 perf_event_ctx_unlock(group_leader
, gctx
);
10177 mutex_lock(&ctx
->mutex
);
10180 if (ctx
->task
== TASK_TOMBSTONE
) {
10185 if (!perf_event_validate_size(event
)) {
10192 * Check if the @cpu we're creating an event for is online.
10194 * We use the perf_cpu_context::ctx::mutex to serialize against
10195 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10197 struct perf_cpu_context
*cpuctx
=
10198 container_of(ctx
, struct perf_cpu_context
, ctx
);
10200 if (!cpuctx
->online
) {
10208 * Must be under the same ctx::mutex as perf_install_in_context(),
10209 * because we need to serialize with concurrent event creation.
10211 if (!exclusive_event_installable(event
, ctx
)) {
10212 /* exclusive and group stuff are assumed mutually exclusive */
10213 WARN_ON_ONCE(move_group
);
10219 WARN_ON_ONCE(ctx
->parent_ctx
);
10222 * This is the point on no return; we cannot fail hereafter. This is
10223 * where we start modifying current state.
10228 * See perf_event_ctx_lock() for comments on the details
10229 * of swizzling perf_event::ctx.
10231 perf_remove_from_context(group_leader
, 0);
10234 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10236 perf_remove_from_context(sibling
, 0);
10241 * Wait for everybody to stop referencing the events through
10242 * the old lists, before installing it on new lists.
10247 * Install the group siblings before the group leader.
10249 * Because a group leader will try and install the entire group
10250 * (through the sibling list, which is still in-tact), we can
10251 * end up with siblings installed in the wrong context.
10253 * By installing siblings first we NO-OP because they're not
10254 * reachable through the group lists.
10256 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10258 perf_event__state_init(sibling
);
10259 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10264 * Removing from the context ends up with disabled
10265 * event. What we want here is event in the initial
10266 * startup state, ready to be add into new context.
10268 perf_event__state_init(group_leader
);
10269 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10274 * Precalculate sample_data sizes; do while holding ctx::mutex such
10275 * that we're serialized against further additions and before
10276 * perf_install_in_context() which is the point the event is active and
10277 * can use these values.
10279 perf_event__header_size(event
);
10280 perf_event__id_header_size(event
);
10282 event
->owner
= current
;
10284 perf_install_in_context(ctx
, event
, event
->cpu
);
10285 perf_unpin_context(ctx
);
10288 perf_event_ctx_unlock(group_leader
, gctx
);
10289 mutex_unlock(&ctx
->mutex
);
10292 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10293 put_task_struct(task
);
10296 mutex_lock(¤t
->perf_event_mutex
);
10297 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10298 mutex_unlock(¤t
->perf_event_mutex
);
10301 * Drop the reference on the group_event after placing the
10302 * new event on the sibling_list. This ensures destruction
10303 * of the group leader will find the pointer to itself in
10304 * perf_group_detach().
10307 fd_install(event_fd
, event_file
);
10312 perf_event_ctx_unlock(group_leader
, gctx
);
10313 mutex_unlock(&ctx
->mutex
);
10317 perf_unpin_context(ctx
);
10321 * If event_file is set, the fput() above will have called ->release()
10322 * and that will take care of freeing the event.
10328 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10331 put_task_struct(task
);
10335 put_unused_fd(event_fd
);
10340 * perf_event_create_kernel_counter
10342 * @attr: attributes of the counter to create
10343 * @cpu: cpu in which the counter is bound
10344 * @task: task to profile (NULL for percpu)
10346 struct perf_event
*
10347 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10348 struct task_struct
*task
,
10349 perf_overflow_handler_t overflow_handler
,
10352 struct perf_event_context
*ctx
;
10353 struct perf_event
*event
;
10357 * Get the target context (task or percpu):
10360 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10361 overflow_handler
, context
, -1);
10362 if (IS_ERR(event
)) {
10363 err
= PTR_ERR(event
);
10367 /* Mark owner so we could distinguish it from user events. */
10368 event
->owner
= TASK_TOMBSTONE
;
10370 ctx
= find_get_context(event
->pmu
, task
, event
);
10372 err
= PTR_ERR(ctx
);
10376 WARN_ON_ONCE(ctx
->parent_ctx
);
10377 mutex_lock(&ctx
->mutex
);
10378 if (ctx
->task
== TASK_TOMBSTONE
) {
10385 * Check if the @cpu we're creating an event for is online.
10387 * We use the perf_cpu_context::ctx::mutex to serialize against
10388 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10390 struct perf_cpu_context
*cpuctx
=
10391 container_of(ctx
, struct perf_cpu_context
, ctx
);
10392 if (!cpuctx
->online
) {
10398 if (!exclusive_event_installable(event
, ctx
)) {
10403 perf_install_in_context(ctx
, event
, cpu
);
10404 perf_unpin_context(ctx
);
10405 mutex_unlock(&ctx
->mutex
);
10410 mutex_unlock(&ctx
->mutex
);
10411 perf_unpin_context(ctx
);
10416 return ERR_PTR(err
);
10418 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10420 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10422 struct perf_event_context
*src_ctx
;
10423 struct perf_event_context
*dst_ctx
;
10424 struct perf_event
*event
, *tmp
;
10427 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10428 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10431 * See perf_event_ctx_lock() for comments on the details
10432 * of swizzling perf_event::ctx.
10434 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10435 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10437 perf_remove_from_context(event
, 0);
10438 unaccount_event_cpu(event
, src_cpu
);
10440 list_add(&event
->migrate_entry
, &events
);
10444 * Wait for the events to quiesce before re-instating them.
10449 * Re-instate events in 2 passes.
10451 * Skip over group leaders and only install siblings on this first
10452 * pass, siblings will not get enabled without a leader, however a
10453 * leader will enable its siblings, even if those are still on the old
10456 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10457 if (event
->group_leader
== event
)
10460 list_del(&event
->migrate_entry
);
10461 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10462 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10463 account_event_cpu(event
, dst_cpu
);
10464 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10469 * Once all the siblings are setup properly, install the group leaders
10472 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10473 list_del(&event
->migrate_entry
);
10474 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10475 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10476 account_event_cpu(event
, dst_cpu
);
10477 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10480 mutex_unlock(&dst_ctx
->mutex
);
10481 mutex_unlock(&src_ctx
->mutex
);
10483 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10485 static void sync_child_event(struct perf_event
*child_event
,
10486 struct task_struct
*child
)
10488 struct perf_event
*parent_event
= child_event
->parent
;
10491 if (child_event
->attr
.inherit_stat
)
10492 perf_event_read_event(child_event
, child
);
10494 child_val
= perf_event_count(child_event
);
10497 * Add back the child's count to the parent's count:
10499 atomic64_add(child_val
, &parent_event
->child_count
);
10500 atomic64_add(child_event
->total_time_enabled
,
10501 &parent_event
->child_total_time_enabled
);
10502 atomic64_add(child_event
->total_time_running
,
10503 &parent_event
->child_total_time_running
);
10507 perf_event_exit_event(struct perf_event
*child_event
,
10508 struct perf_event_context
*child_ctx
,
10509 struct task_struct
*child
)
10511 struct perf_event
*parent_event
= child_event
->parent
;
10514 * Do not destroy the 'original' grouping; because of the context
10515 * switch optimization the original events could've ended up in a
10516 * random child task.
10518 * If we were to destroy the original group, all group related
10519 * operations would cease to function properly after this random
10522 * Do destroy all inherited groups, we don't care about those
10523 * and being thorough is better.
10525 raw_spin_lock_irq(&child_ctx
->lock
);
10526 WARN_ON_ONCE(child_ctx
->is_active
);
10529 perf_group_detach(child_event
);
10530 list_del_event(child_event
, child_ctx
);
10531 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10532 raw_spin_unlock_irq(&child_ctx
->lock
);
10535 * Parent events are governed by their filedesc, retain them.
10537 if (!parent_event
) {
10538 perf_event_wakeup(child_event
);
10542 * Child events can be cleaned up.
10545 sync_child_event(child_event
, child
);
10548 * Remove this event from the parent's list
10550 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10551 mutex_lock(&parent_event
->child_mutex
);
10552 list_del_init(&child_event
->child_list
);
10553 mutex_unlock(&parent_event
->child_mutex
);
10556 * Kick perf_poll() for is_event_hup().
10558 perf_event_wakeup(parent_event
);
10559 free_event(child_event
);
10560 put_event(parent_event
);
10563 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10565 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10566 struct perf_event
*child_event
, *next
;
10568 WARN_ON_ONCE(child
!= current
);
10570 child_ctx
= perf_pin_task_context(child
, ctxn
);
10575 * In order to reduce the amount of tricky in ctx tear-down, we hold
10576 * ctx::mutex over the entire thing. This serializes against almost
10577 * everything that wants to access the ctx.
10579 * The exception is sys_perf_event_open() /
10580 * perf_event_create_kernel_count() which does find_get_context()
10581 * without ctx::mutex (it cannot because of the move_group double mutex
10582 * lock thing). See the comments in perf_install_in_context().
10584 mutex_lock(&child_ctx
->mutex
);
10587 * In a single ctx::lock section, de-schedule the events and detach the
10588 * context from the task such that we cannot ever get it scheduled back
10591 raw_spin_lock_irq(&child_ctx
->lock
);
10592 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10595 * Now that the context is inactive, destroy the task <-> ctx relation
10596 * and mark the context dead.
10598 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10599 put_ctx(child_ctx
); /* cannot be last */
10600 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10601 put_task_struct(current
); /* cannot be last */
10603 clone_ctx
= unclone_ctx(child_ctx
);
10604 raw_spin_unlock_irq(&child_ctx
->lock
);
10607 put_ctx(clone_ctx
);
10610 * Report the task dead after unscheduling the events so that we
10611 * won't get any samples after PERF_RECORD_EXIT. We can however still
10612 * get a few PERF_RECORD_READ events.
10614 perf_event_task(child
, child_ctx
, 0);
10616 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10617 perf_event_exit_event(child_event
, child_ctx
, child
);
10619 mutex_unlock(&child_ctx
->mutex
);
10621 put_ctx(child_ctx
);
10625 * When a child task exits, feed back event values to parent events.
10627 * Can be called with cred_guard_mutex held when called from
10628 * install_exec_creds().
10630 void perf_event_exit_task(struct task_struct
*child
)
10632 struct perf_event
*event
, *tmp
;
10635 mutex_lock(&child
->perf_event_mutex
);
10636 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10638 list_del_init(&event
->owner_entry
);
10641 * Ensure the list deletion is visible before we clear
10642 * the owner, closes a race against perf_release() where
10643 * we need to serialize on the owner->perf_event_mutex.
10645 smp_store_release(&event
->owner
, NULL
);
10647 mutex_unlock(&child
->perf_event_mutex
);
10649 for_each_task_context_nr(ctxn
)
10650 perf_event_exit_task_context(child
, ctxn
);
10653 * The perf_event_exit_task_context calls perf_event_task
10654 * with child's task_ctx, which generates EXIT events for
10655 * child contexts and sets child->perf_event_ctxp[] to NULL.
10656 * At this point we need to send EXIT events to cpu contexts.
10658 perf_event_task(child
, NULL
, 0);
10661 static void perf_free_event(struct perf_event
*event
,
10662 struct perf_event_context
*ctx
)
10664 struct perf_event
*parent
= event
->parent
;
10666 if (WARN_ON_ONCE(!parent
))
10669 mutex_lock(&parent
->child_mutex
);
10670 list_del_init(&event
->child_list
);
10671 mutex_unlock(&parent
->child_mutex
);
10675 raw_spin_lock_irq(&ctx
->lock
);
10676 perf_group_detach(event
);
10677 list_del_event(event
, ctx
);
10678 raw_spin_unlock_irq(&ctx
->lock
);
10683 * Free an unexposed, unused context as created by inheritance by
10684 * perf_event_init_task below, used by fork() in case of fail.
10686 * Not all locks are strictly required, but take them anyway to be nice and
10687 * help out with the lockdep assertions.
10689 void perf_event_free_task(struct task_struct
*task
)
10691 struct perf_event_context
*ctx
;
10692 struct perf_event
*event
, *tmp
;
10695 for_each_task_context_nr(ctxn
) {
10696 ctx
= task
->perf_event_ctxp
[ctxn
];
10700 mutex_lock(&ctx
->mutex
);
10701 raw_spin_lock_irq(&ctx
->lock
);
10703 * Destroy the task <-> ctx relation and mark the context dead.
10705 * This is important because even though the task hasn't been
10706 * exposed yet the context has been (through child_list).
10708 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10709 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10710 put_task_struct(task
); /* cannot be last */
10711 raw_spin_unlock_irq(&ctx
->lock
);
10713 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10714 perf_free_event(event
, ctx
);
10716 mutex_unlock(&ctx
->mutex
);
10721 void perf_event_delayed_put(struct task_struct
*task
)
10725 for_each_task_context_nr(ctxn
)
10726 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10729 struct file
*perf_event_get(unsigned int fd
)
10733 file
= fget_raw(fd
);
10735 return ERR_PTR(-EBADF
);
10737 if (file
->f_op
!= &perf_fops
) {
10739 return ERR_PTR(-EBADF
);
10745 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10748 return ERR_PTR(-EINVAL
);
10750 return &event
->attr
;
10754 * Inherit a event from parent task to child task.
10757 * - valid pointer on success
10758 * - NULL for orphaned events
10759 * - IS_ERR() on error
10761 static struct perf_event
*
10762 inherit_event(struct perf_event
*parent_event
,
10763 struct task_struct
*parent
,
10764 struct perf_event_context
*parent_ctx
,
10765 struct task_struct
*child
,
10766 struct perf_event
*group_leader
,
10767 struct perf_event_context
*child_ctx
)
10769 enum perf_event_active_state parent_state
= parent_event
->state
;
10770 struct perf_event
*child_event
;
10771 unsigned long flags
;
10774 * Instead of creating recursive hierarchies of events,
10775 * we link inherited events back to the original parent,
10776 * which has a filp for sure, which we use as the reference
10779 if (parent_event
->parent
)
10780 parent_event
= parent_event
->parent
;
10782 child_event
= perf_event_alloc(&parent_event
->attr
,
10785 group_leader
, parent_event
,
10787 if (IS_ERR(child_event
))
10788 return child_event
;
10791 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10792 * must be under the same lock in order to serialize against
10793 * perf_event_release_kernel(), such that either we must observe
10794 * is_orphaned_event() or they will observe us on the child_list.
10796 mutex_lock(&parent_event
->child_mutex
);
10797 if (is_orphaned_event(parent_event
) ||
10798 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10799 mutex_unlock(&parent_event
->child_mutex
);
10800 free_event(child_event
);
10804 get_ctx(child_ctx
);
10807 * Make the child state follow the state of the parent event,
10808 * not its attr.disabled bit. We hold the parent's mutex,
10809 * so we won't race with perf_event_{en, dis}able_family.
10811 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10812 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10814 child_event
->state
= PERF_EVENT_STATE_OFF
;
10816 if (parent_event
->attr
.freq
) {
10817 u64 sample_period
= parent_event
->hw
.sample_period
;
10818 struct hw_perf_event
*hwc
= &child_event
->hw
;
10820 hwc
->sample_period
= sample_period
;
10821 hwc
->last_period
= sample_period
;
10823 local64_set(&hwc
->period_left
, sample_period
);
10826 child_event
->ctx
= child_ctx
;
10827 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10828 child_event
->overflow_handler_context
10829 = parent_event
->overflow_handler_context
;
10832 * Precalculate sample_data sizes
10834 perf_event__header_size(child_event
);
10835 perf_event__id_header_size(child_event
);
10838 * Link it up in the child's context:
10840 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10841 add_event_to_ctx(child_event
, child_ctx
);
10842 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10845 * Link this into the parent event's child list
10847 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10848 mutex_unlock(&parent_event
->child_mutex
);
10850 return child_event
;
10854 * Inherits an event group.
10856 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10857 * This matches with perf_event_release_kernel() removing all child events.
10863 static int inherit_group(struct perf_event
*parent_event
,
10864 struct task_struct
*parent
,
10865 struct perf_event_context
*parent_ctx
,
10866 struct task_struct
*child
,
10867 struct perf_event_context
*child_ctx
)
10869 struct perf_event
*leader
;
10870 struct perf_event
*sub
;
10871 struct perf_event
*child_ctr
;
10873 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10874 child
, NULL
, child_ctx
);
10875 if (IS_ERR(leader
))
10876 return PTR_ERR(leader
);
10878 * @leader can be NULL here because of is_orphaned_event(). In this
10879 * case inherit_event() will create individual events, similar to what
10880 * perf_group_detach() would do anyway.
10882 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10883 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10884 child
, leader
, child_ctx
);
10885 if (IS_ERR(child_ctr
))
10886 return PTR_ERR(child_ctr
);
10892 * Creates the child task context and tries to inherit the event-group.
10894 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10895 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10896 * consistent with perf_event_release_kernel() removing all child events.
10903 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10904 struct perf_event_context
*parent_ctx
,
10905 struct task_struct
*child
, int ctxn
,
10906 int *inherited_all
)
10909 struct perf_event_context
*child_ctx
;
10911 if (!event
->attr
.inherit
) {
10912 *inherited_all
= 0;
10916 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10919 * This is executed from the parent task context, so
10920 * inherit events that have been marked for cloning.
10921 * First allocate and initialize a context for the
10924 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10928 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10931 ret
= inherit_group(event
, parent
, parent_ctx
,
10935 *inherited_all
= 0;
10941 * Initialize the perf_event context in task_struct
10943 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10945 struct perf_event_context
*child_ctx
, *parent_ctx
;
10946 struct perf_event_context
*cloned_ctx
;
10947 struct perf_event
*event
;
10948 struct task_struct
*parent
= current
;
10949 int inherited_all
= 1;
10950 unsigned long flags
;
10953 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10957 * If the parent's context is a clone, pin it so it won't get
10958 * swapped under us.
10960 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10965 * No need to check if parent_ctx != NULL here; since we saw
10966 * it non-NULL earlier, the only reason for it to become NULL
10967 * is if we exit, and since we're currently in the middle of
10968 * a fork we can't be exiting at the same time.
10972 * Lock the parent list. No need to lock the child - not PID
10973 * hashed yet and not running, so nobody can access it.
10975 mutex_lock(&parent_ctx
->mutex
);
10978 * We dont have to disable NMIs - we are only looking at
10979 * the list, not manipulating it:
10981 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10982 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10983 child
, ctxn
, &inherited_all
);
10989 * We can't hold ctx->lock when iterating the ->flexible_group list due
10990 * to allocations, but we need to prevent rotation because
10991 * rotate_ctx() will change the list from interrupt context.
10993 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10994 parent_ctx
->rotate_disable
= 1;
10995 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10997 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10998 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10999 child
, ctxn
, &inherited_all
);
11004 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11005 parent_ctx
->rotate_disable
= 0;
11007 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11009 if (child_ctx
&& inherited_all
) {
11011 * Mark the child context as a clone of the parent
11012 * context, or of whatever the parent is a clone of.
11014 * Note that if the parent is a clone, the holding of
11015 * parent_ctx->lock avoids it from being uncloned.
11017 cloned_ctx
= parent_ctx
->parent_ctx
;
11019 child_ctx
->parent_ctx
= cloned_ctx
;
11020 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
11022 child_ctx
->parent_ctx
= parent_ctx
;
11023 child_ctx
->parent_gen
= parent_ctx
->generation
;
11025 get_ctx(child_ctx
->parent_ctx
);
11028 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11030 mutex_unlock(&parent_ctx
->mutex
);
11032 perf_unpin_context(parent_ctx
);
11033 put_ctx(parent_ctx
);
11039 * Initialize the perf_event context in task_struct
11041 int perf_event_init_task(struct task_struct
*child
)
11045 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
11046 mutex_init(&child
->perf_event_mutex
);
11047 INIT_LIST_HEAD(&child
->perf_event_list
);
11049 for_each_task_context_nr(ctxn
) {
11050 ret
= perf_event_init_context(child
, ctxn
);
11052 perf_event_free_task(child
);
11060 static void __init
perf_event_init_all_cpus(void)
11062 struct swevent_htable
*swhash
;
11065 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
11067 for_each_possible_cpu(cpu
) {
11068 swhash
= &per_cpu(swevent_htable
, cpu
);
11069 mutex_init(&swhash
->hlist_mutex
);
11070 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11072 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11073 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11075 #ifdef CONFIG_CGROUP_PERF
11076 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11078 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11082 void perf_swevent_init_cpu(unsigned int cpu
)
11084 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11086 mutex_lock(&swhash
->hlist_mutex
);
11087 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11088 struct swevent_hlist
*hlist
;
11090 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11092 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11094 mutex_unlock(&swhash
->hlist_mutex
);
11097 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11098 static void __perf_event_exit_context(void *__info
)
11100 struct perf_event_context
*ctx
= __info
;
11101 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11102 struct perf_event
*event
;
11104 raw_spin_lock(&ctx
->lock
);
11105 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11106 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11107 raw_spin_unlock(&ctx
->lock
);
11110 static void perf_event_exit_cpu_context(int cpu
)
11112 struct perf_cpu_context
*cpuctx
;
11113 struct perf_event_context
*ctx
;
11116 mutex_lock(&pmus_lock
);
11117 list_for_each_entry(pmu
, &pmus
, entry
) {
11118 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11119 ctx
= &cpuctx
->ctx
;
11121 mutex_lock(&ctx
->mutex
);
11122 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11123 cpuctx
->online
= 0;
11124 mutex_unlock(&ctx
->mutex
);
11126 cpumask_clear_cpu(cpu
, perf_online_mask
);
11127 mutex_unlock(&pmus_lock
);
11131 static void perf_event_exit_cpu_context(int cpu
) { }
11135 int perf_event_init_cpu(unsigned int cpu
)
11137 struct perf_cpu_context
*cpuctx
;
11138 struct perf_event_context
*ctx
;
11141 perf_swevent_init_cpu(cpu
);
11143 mutex_lock(&pmus_lock
);
11144 cpumask_set_cpu(cpu
, perf_online_mask
);
11145 list_for_each_entry(pmu
, &pmus
, entry
) {
11146 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11147 ctx
= &cpuctx
->ctx
;
11149 mutex_lock(&ctx
->mutex
);
11150 cpuctx
->online
= 1;
11151 mutex_unlock(&ctx
->mutex
);
11153 mutex_unlock(&pmus_lock
);
11158 int perf_event_exit_cpu(unsigned int cpu
)
11160 perf_event_exit_cpu_context(cpu
);
11165 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11169 for_each_online_cpu(cpu
)
11170 perf_event_exit_cpu(cpu
);
11176 * Run the perf reboot notifier at the very last possible moment so that
11177 * the generic watchdog code runs as long as possible.
11179 static struct notifier_block perf_reboot_notifier
= {
11180 .notifier_call
= perf_reboot
,
11181 .priority
= INT_MIN
,
11184 void __init
perf_event_init(void)
11188 idr_init(&pmu_idr
);
11190 perf_event_init_all_cpus();
11191 init_srcu_struct(&pmus_srcu
);
11192 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11193 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11194 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11195 perf_tp_register();
11196 perf_event_init_cpu(smp_processor_id());
11197 register_reboot_notifier(&perf_reboot_notifier
);
11199 ret
= init_hw_breakpoint();
11200 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11203 * Build time assertion that we keep the data_head at the intended
11204 * location. IOW, validation we got the __reserved[] size right.
11206 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11210 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11213 struct perf_pmu_events_attr
*pmu_attr
=
11214 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11216 if (pmu_attr
->event_str
)
11217 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11221 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11223 static int __init
perf_event_sysfs_init(void)
11228 mutex_lock(&pmus_lock
);
11230 ret
= bus_register(&pmu_bus
);
11234 list_for_each_entry(pmu
, &pmus
, entry
) {
11235 if (!pmu
->name
|| pmu
->type
< 0)
11238 ret
= pmu_dev_alloc(pmu
);
11239 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11241 pmu_bus_running
= 1;
11245 mutex_unlock(&pmus_lock
);
11249 device_initcall(perf_event_sysfs_init
);
11251 #ifdef CONFIG_CGROUP_PERF
11252 static struct cgroup_subsys_state
*
11253 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11255 struct perf_cgroup
*jc
;
11257 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11259 return ERR_PTR(-ENOMEM
);
11261 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11264 return ERR_PTR(-ENOMEM
);
11270 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11272 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11274 free_percpu(jc
->info
);
11278 static int __perf_cgroup_move(void *info
)
11280 struct task_struct
*task
= info
;
11282 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11287 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11289 struct task_struct
*task
;
11290 struct cgroup_subsys_state
*css
;
11292 cgroup_taskset_for_each(task
, css
, tset
)
11293 task_function_call(task
, __perf_cgroup_move
, task
);
11296 struct cgroup_subsys perf_event_cgrp_subsys
= {
11297 .css_alloc
= perf_cgroup_css_alloc
,
11298 .css_free
= perf_cgroup_css_free
,
11299 .attach
= perf_cgroup_attach
,
11301 * Implicitly enable on dfl hierarchy so that perf events can
11302 * always be filtered by cgroup2 path as long as perf_event
11303 * controller is not mounted on a legacy hierarchy.
11305 .implicit_on_dfl
= true,
11307 #endif /* CONFIG_CGROUP_PERF */