2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 lockdep_assert_irqs_disabled();
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 lockdep_assert_irqs_disabled();
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
392 static cpumask_var_t perf_online_mask
;
395 * perf event paranoia level:
396 * -1 - not paranoid at all
397 * 0 - disallow raw tracepoint access for unpriv
398 * 1 - disallow cpu events for unpriv
399 * 2 - disallow kernel profiling for unpriv
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 bool 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
,
440 int perf_cpu
= sysctl_perf_cpu_time_max_percent
;
442 * If throttling is disabled don't allow the write:
444 if (write
&& (perf_cpu
== 100 || perf_cpu
== 0))
447 ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
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();
586 * State based event timekeeping...
588 * The basic idea is to use event->state to determine which (if any) time
589 * fields to increment with the current delta. This means we only need to
590 * update timestamps when we change state or when they are explicitly requested
593 * Event groups make things a little more complicated, but not terribly so. The
594 * rules for a group are that if the group leader is OFF the entire group is
595 * OFF, irrespecive of what the group member states are. This results in
596 * __perf_effective_state().
598 * A futher ramification is that when a group leader flips between OFF and
599 * !OFF, we need to update all group member times.
602 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
603 * need to make sure the relevant context time is updated before we try and
604 * update our timestamps.
607 static __always_inline
enum perf_event_state
608 __perf_effective_state(struct perf_event
*event
)
610 struct perf_event
*leader
= event
->group_leader
;
612 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
613 return leader
->state
;
618 static __always_inline
void
619 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
621 enum perf_event_state state
= __perf_effective_state(event
);
622 u64 delta
= now
- event
->tstamp
;
624 *enabled
= event
->total_time_enabled
;
625 if (state
>= PERF_EVENT_STATE_INACTIVE
)
628 *running
= event
->total_time_running
;
629 if (state
>= PERF_EVENT_STATE_ACTIVE
)
633 static void perf_event_update_time(struct perf_event
*event
)
635 u64 now
= perf_event_time(event
);
637 __perf_update_times(event
, now
, &event
->total_time_enabled
,
638 &event
->total_time_running
);
642 static void perf_event_update_sibling_time(struct perf_event
*leader
)
644 struct perf_event
*sibling
;
646 for_each_sibling_event(sibling
, leader
)
647 perf_event_update_time(sibling
);
651 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
653 if (event
->state
== state
)
656 perf_event_update_time(event
);
658 * If a group leader gets enabled/disabled all its siblings
661 if ((event
->state
< 0) ^ (state
< 0))
662 perf_event_update_sibling_time(event
);
664 WRITE_ONCE(event
->state
, state
);
667 #ifdef CONFIG_CGROUP_PERF
670 perf_cgroup_match(struct perf_event
*event
)
672 struct perf_event_context
*ctx
= event
->ctx
;
673 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
675 /* @event doesn't care about cgroup */
679 /* wants specific cgroup scope but @cpuctx isn't associated with any */
684 * Cgroup scoping is recursive. An event enabled for a cgroup is
685 * also enabled for all its descendant cgroups. If @cpuctx's
686 * cgroup is a descendant of @event's (the test covers identity
687 * case), it's a match.
689 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
690 event
->cgrp
->css
.cgroup
);
693 static inline void perf_detach_cgroup(struct perf_event
*event
)
695 css_put(&event
->cgrp
->css
);
699 static inline int is_cgroup_event(struct perf_event
*event
)
701 return event
->cgrp
!= NULL
;
704 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
706 struct perf_cgroup_info
*t
;
708 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
712 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
714 struct perf_cgroup_info
*info
;
719 info
= this_cpu_ptr(cgrp
->info
);
721 info
->time
+= now
- info
->timestamp
;
722 info
->timestamp
= now
;
725 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
727 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
728 struct cgroup_subsys_state
*css
;
731 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
732 cgrp
= container_of(css
, struct perf_cgroup
, css
);
733 __update_cgrp_time(cgrp
);
738 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
740 struct perf_cgroup
*cgrp
;
743 * ensure we access cgroup data only when needed and
744 * when we know the cgroup is pinned (css_get)
746 if (!is_cgroup_event(event
))
749 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
751 * Do not update time when cgroup is not active
753 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
754 __update_cgrp_time(event
->cgrp
);
758 perf_cgroup_set_timestamp(struct task_struct
*task
,
759 struct perf_event_context
*ctx
)
761 struct perf_cgroup
*cgrp
;
762 struct perf_cgroup_info
*info
;
763 struct cgroup_subsys_state
*css
;
766 * ctx->lock held by caller
767 * ensure we do not access cgroup data
768 * unless we have the cgroup pinned (css_get)
770 if (!task
|| !ctx
->nr_cgroups
)
773 cgrp
= perf_cgroup_from_task(task
, ctx
);
775 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
776 cgrp
= container_of(css
, struct perf_cgroup
, css
);
777 info
= this_cpu_ptr(cgrp
->info
);
778 info
->timestamp
= ctx
->timestamp
;
782 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
784 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
785 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
788 * reschedule events based on the cgroup constraint of task.
790 * mode SWOUT : schedule out everything
791 * mode SWIN : schedule in based on cgroup for next
793 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
795 struct perf_cpu_context
*cpuctx
;
796 struct list_head
*list
;
800 * Disable interrupts and preemption to avoid this CPU's
801 * cgrp_cpuctx_entry to change under us.
803 local_irq_save(flags
);
805 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
806 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
807 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
809 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
810 perf_pmu_disable(cpuctx
->ctx
.pmu
);
812 if (mode
& PERF_CGROUP_SWOUT
) {
813 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
815 * must not be done before ctxswout due
816 * to event_filter_match() in event_sched_out()
821 if (mode
& PERF_CGROUP_SWIN
) {
822 WARN_ON_ONCE(cpuctx
->cgrp
);
824 * set cgrp before ctxsw in to allow
825 * event_filter_match() to not have to pass
827 * we pass the cpuctx->ctx to perf_cgroup_from_task()
828 * because cgorup events are only per-cpu
830 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
832 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
834 perf_pmu_enable(cpuctx
->ctx
.pmu
);
835 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
838 local_irq_restore(flags
);
841 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
842 struct task_struct
*next
)
844 struct perf_cgroup
*cgrp1
;
845 struct perf_cgroup
*cgrp2
= NULL
;
849 * we come here when we know perf_cgroup_events > 0
850 * we do not need to pass the ctx here because we know
851 * we are holding the rcu lock
853 cgrp1
= perf_cgroup_from_task(task
, NULL
);
854 cgrp2
= perf_cgroup_from_task(next
, NULL
);
857 * only schedule out current cgroup events if we know
858 * that we are switching to a different cgroup. Otherwise,
859 * do no touch the cgroup events.
862 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
867 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
868 struct task_struct
*task
)
870 struct perf_cgroup
*cgrp1
;
871 struct perf_cgroup
*cgrp2
= NULL
;
875 * we come here when we know perf_cgroup_events > 0
876 * we do not need to pass the ctx here because we know
877 * we are holding the rcu lock
879 cgrp1
= perf_cgroup_from_task(task
, NULL
);
880 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
883 * only need to schedule in cgroup events if we are changing
884 * cgroup during ctxsw. Cgroup events were not scheduled
885 * out of ctxsw out if that was not the case.
888 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
893 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
894 struct perf_event_attr
*attr
,
895 struct perf_event
*group_leader
)
897 struct perf_cgroup
*cgrp
;
898 struct cgroup_subsys_state
*css
;
899 struct fd f
= fdget(fd
);
905 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
906 &perf_event_cgrp_subsys
);
912 cgrp
= container_of(css
, struct perf_cgroup
, css
);
916 * all events in a group must monitor
917 * the same cgroup because a task belongs
918 * to only one perf cgroup at a time
920 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
921 perf_detach_cgroup(event
);
930 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
932 struct perf_cgroup_info
*t
;
933 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
934 event
->shadow_ctx_time
= now
- t
->timestamp
;
938 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
939 * cleared when last cgroup event is removed.
942 list_update_cgroup_event(struct perf_event
*event
,
943 struct perf_event_context
*ctx
, bool add
)
945 struct perf_cpu_context
*cpuctx
;
946 struct list_head
*cpuctx_entry
;
948 if (!is_cgroup_event(event
))
952 * Because cgroup events are always per-cpu events,
953 * this will always be called from the right CPU.
955 cpuctx
= __get_cpu_context(ctx
);
958 * Since setting cpuctx->cgrp is conditional on the current @cgrp
959 * matching the event's cgroup, we must do this for every new event,
960 * because if the first would mismatch, the second would not try again
961 * and we would leave cpuctx->cgrp unset.
963 if (add
&& !cpuctx
->cgrp
) {
964 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
966 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
970 if (add
&& ctx
->nr_cgroups
++)
972 else if (!add
&& --ctx
->nr_cgroups
)
975 /* no cgroup running */
979 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
981 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
983 list_del(cpuctx_entry
);
986 #else /* !CONFIG_CGROUP_PERF */
989 perf_cgroup_match(struct perf_event
*event
)
994 static inline void perf_detach_cgroup(struct perf_event
*event
)
997 static inline int is_cgroup_event(struct perf_event
*event
)
1002 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1006 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1010 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1011 struct task_struct
*next
)
1015 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1016 struct task_struct
*task
)
1020 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1021 struct perf_event_attr
*attr
,
1022 struct perf_event
*group_leader
)
1028 perf_cgroup_set_timestamp(struct task_struct
*task
,
1029 struct perf_event_context
*ctx
)
1034 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1039 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1043 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1049 list_update_cgroup_event(struct perf_event
*event
,
1050 struct perf_event_context
*ctx
, bool add
)
1057 * set default to be dependent on timer tick just
1058 * like original code
1060 #define PERF_CPU_HRTIMER (1000 / HZ)
1062 * function must be called with interrupts disabled
1064 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1066 struct perf_cpu_context
*cpuctx
;
1069 lockdep_assert_irqs_disabled();
1071 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1072 rotations
= perf_rotate_context(cpuctx
);
1074 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1076 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1078 cpuctx
->hrtimer_active
= 0;
1079 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1081 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1084 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1086 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1087 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1090 /* no multiplexing needed for SW PMU */
1091 if (pmu
->task_ctx_nr
== perf_sw_context
)
1095 * check default is sane, if not set then force to
1096 * default interval (1/tick)
1098 interval
= pmu
->hrtimer_interval_ms
;
1100 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1102 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1104 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1105 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1106 timer
->function
= perf_mux_hrtimer_handler
;
1109 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1111 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1112 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1113 unsigned long flags
;
1115 /* not for SW PMU */
1116 if (pmu
->task_ctx_nr
== perf_sw_context
)
1119 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1120 if (!cpuctx
->hrtimer_active
) {
1121 cpuctx
->hrtimer_active
= 1;
1122 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1123 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1125 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1130 void perf_pmu_disable(struct pmu
*pmu
)
1132 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1134 pmu
->pmu_disable(pmu
);
1137 void perf_pmu_enable(struct pmu
*pmu
)
1139 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1141 pmu
->pmu_enable(pmu
);
1144 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1147 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1148 * perf_event_task_tick() are fully serialized because they're strictly cpu
1149 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1150 * disabled, while perf_event_task_tick is called from IRQ context.
1152 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1154 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1156 lockdep_assert_irqs_disabled();
1158 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1160 list_add(&ctx
->active_ctx_list
, head
);
1163 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1165 lockdep_assert_irqs_disabled();
1167 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1169 list_del_init(&ctx
->active_ctx_list
);
1172 static void get_ctx(struct perf_event_context
*ctx
)
1174 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1177 static void free_ctx(struct rcu_head
*head
)
1179 struct perf_event_context
*ctx
;
1181 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1182 kfree(ctx
->task_ctx_data
);
1186 static void put_ctx(struct perf_event_context
*ctx
)
1188 if (atomic_dec_and_test(&ctx
->refcount
)) {
1189 if (ctx
->parent_ctx
)
1190 put_ctx(ctx
->parent_ctx
);
1191 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1192 put_task_struct(ctx
->task
);
1193 call_rcu(&ctx
->rcu_head
, free_ctx
);
1198 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1199 * perf_pmu_migrate_context() we need some magic.
1201 * Those places that change perf_event::ctx will hold both
1202 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1204 * Lock ordering is by mutex address. There are two other sites where
1205 * perf_event_context::mutex nests and those are:
1207 * - perf_event_exit_task_context() [ child , 0 ]
1208 * perf_event_exit_event()
1209 * put_event() [ parent, 1 ]
1211 * - perf_event_init_context() [ parent, 0 ]
1212 * inherit_task_group()
1215 * perf_event_alloc()
1217 * perf_try_init_event() [ child , 1 ]
1219 * While it appears there is an obvious deadlock here -- the parent and child
1220 * nesting levels are inverted between the two. This is in fact safe because
1221 * life-time rules separate them. That is an exiting task cannot fork, and a
1222 * spawning task cannot (yet) exit.
1224 * But remember that that these are parent<->child context relations, and
1225 * migration does not affect children, therefore these two orderings should not
1228 * The change in perf_event::ctx does not affect children (as claimed above)
1229 * because the sys_perf_event_open() case will install a new event and break
1230 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1231 * concerned with cpuctx and that doesn't have children.
1233 * The places that change perf_event::ctx will issue:
1235 * perf_remove_from_context();
1236 * synchronize_rcu();
1237 * perf_install_in_context();
1239 * to affect the change. The remove_from_context() + synchronize_rcu() should
1240 * quiesce the event, after which we can install it in the new location. This
1241 * means that only external vectors (perf_fops, prctl) can perturb the event
1242 * while in transit. Therefore all such accessors should also acquire
1243 * perf_event_context::mutex to serialize against this.
1245 * However; because event->ctx can change while we're waiting to acquire
1246 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1251 * task_struct::perf_event_mutex
1252 * perf_event_context::mutex
1253 * perf_event::child_mutex;
1254 * perf_event_context::lock
1255 * perf_event::mmap_mutex
1260 * cpuctx->mutex / perf_event_context::mutex
1262 static struct perf_event_context
*
1263 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1265 struct perf_event_context
*ctx
;
1269 ctx
= READ_ONCE(event
->ctx
);
1270 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1276 mutex_lock_nested(&ctx
->mutex
, nesting
);
1277 if (event
->ctx
!= ctx
) {
1278 mutex_unlock(&ctx
->mutex
);
1286 static inline struct perf_event_context
*
1287 perf_event_ctx_lock(struct perf_event
*event
)
1289 return perf_event_ctx_lock_nested(event
, 0);
1292 static void perf_event_ctx_unlock(struct perf_event
*event
,
1293 struct perf_event_context
*ctx
)
1295 mutex_unlock(&ctx
->mutex
);
1300 * This must be done under the ctx->lock, such as to serialize against
1301 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1302 * calling scheduler related locks and ctx->lock nests inside those.
1304 static __must_check
struct perf_event_context
*
1305 unclone_ctx(struct perf_event_context
*ctx
)
1307 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1309 lockdep_assert_held(&ctx
->lock
);
1312 ctx
->parent_ctx
= NULL
;
1318 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1323 * only top level events have the pid namespace they were created in
1326 event
= event
->parent
;
1328 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1329 /* avoid -1 if it is idle thread or runs in another ns */
1330 if (!nr
&& !pid_alive(p
))
1335 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1337 return perf_event_pid_type(event
, p
, PIDTYPE_TGID
);
1340 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1342 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1346 * If we inherit events we want to return the parent event id
1349 static u64
primary_event_id(struct perf_event
*event
)
1354 id
= event
->parent
->id
;
1360 * Get the perf_event_context for a task and lock it.
1362 * This has to cope with with the fact that until it is locked,
1363 * the context could get moved to another task.
1365 static struct perf_event_context
*
1366 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1368 struct perf_event_context
*ctx
;
1372 * One of the few rules of preemptible RCU is that one cannot do
1373 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1374 * part of the read side critical section was irqs-enabled -- see
1375 * rcu_read_unlock_special().
1377 * Since ctx->lock nests under rq->lock we must ensure the entire read
1378 * side critical section has interrupts disabled.
1380 local_irq_save(*flags
);
1382 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1385 * If this context is a clone of another, it might
1386 * get swapped for another underneath us by
1387 * perf_event_task_sched_out, though the
1388 * rcu_read_lock() protects us from any context
1389 * getting freed. Lock the context and check if it
1390 * got swapped before we could get the lock, and retry
1391 * if so. If we locked the right context, then it
1392 * can't get swapped on us any more.
1394 raw_spin_lock(&ctx
->lock
);
1395 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1396 raw_spin_unlock(&ctx
->lock
);
1398 local_irq_restore(*flags
);
1402 if (ctx
->task
== TASK_TOMBSTONE
||
1403 !atomic_inc_not_zero(&ctx
->refcount
)) {
1404 raw_spin_unlock(&ctx
->lock
);
1407 WARN_ON_ONCE(ctx
->task
!= task
);
1412 local_irq_restore(*flags
);
1417 * Get the context for a task and increment its pin_count so it
1418 * can't get swapped to another task. This also increments its
1419 * reference count so that the context can't get freed.
1421 static struct perf_event_context
*
1422 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1424 struct perf_event_context
*ctx
;
1425 unsigned long flags
;
1427 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1430 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1435 static void perf_unpin_context(struct perf_event_context
*ctx
)
1437 unsigned long flags
;
1439 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1441 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1445 * Update the record of the current time in a context.
1447 static void update_context_time(struct perf_event_context
*ctx
)
1449 u64 now
= perf_clock();
1451 ctx
->time
+= now
- ctx
->timestamp
;
1452 ctx
->timestamp
= now
;
1455 static u64
perf_event_time(struct perf_event
*event
)
1457 struct perf_event_context
*ctx
= event
->ctx
;
1459 if (is_cgroup_event(event
))
1460 return perf_cgroup_event_time(event
);
1462 return ctx
? ctx
->time
: 0;
1465 static enum event_type_t
get_event_type(struct perf_event
*event
)
1467 struct perf_event_context
*ctx
= event
->ctx
;
1468 enum event_type_t event_type
;
1470 lockdep_assert_held(&ctx
->lock
);
1473 * It's 'group type', really, because if our group leader is
1474 * pinned, so are we.
1476 if (event
->group_leader
!= event
)
1477 event
= event
->group_leader
;
1479 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1481 event_type
|= EVENT_CPU
;
1487 * Helper function to initialize event group nodes.
1489 static void init_event_group(struct perf_event
*event
)
1491 RB_CLEAR_NODE(&event
->group_node
);
1492 event
->group_index
= 0;
1496 * Extract pinned or flexible groups from the context
1497 * based on event attrs bits.
1499 static struct perf_event_groups
*
1500 get_event_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1502 if (event
->attr
.pinned
)
1503 return &ctx
->pinned_groups
;
1505 return &ctx
->flexible_groups
;
1509 * Helper function to initializes perf_event_group trees.
1511 static void perf_event_groups_init(struct perf_event_groups
*groups
)
1513 groups
->tree
= RB_ROOT
;
1518 * Compare function for event groups;
1520 * Implements complex key that first sorts by CPU and then by virtual index
1521 * which provides ordering when rotating groups for the same CPU.
1524 perf_event_groups_less(struct perf_event
*left
, struct perf_event
*right
)
1526 if (left
->cpu
< right
->cpu
)
1528 if (left
->cpu
> right
->cpu
)
1531 if (left
->group_index
< right
->group_index
)
1533 if (left
->group_index
> right
->group_index
)
1540 * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
1541 * key (see perf_event_groups_less). This places it last inside the CPU
1545 perf_event_groups_insert(struct perf_event_groups
*groups
,
1546 struct perf_event
*event
)
1548 struct perf_event
*node_event
;
1549 struct rb_node
*parent
;
1550 struct rb_node
**node
;
1552 event
->group_index
= ++groups
->index
;
1554 node
= &groups
->tree
.rb_node
;
1559 node_event
= container_of(*node
, struct perf_event
, group_node
);
1561 if (perf_event_groups_less(event
, node_event
))
1562 node
= &parent
->rb_left
;
1564 node
= &parent
->rb_right
;
1567 rb_link_node(&event
->group_node
, parent
, node
);
1568 rb_insert_color(&event
->group_node
, &groups
->tree
);
1572 * Helper function to insert event into the pinned or flexible groups.
1575 add_event_to_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1577 struct perf_event_groups
*groups
;
1579 groups
= get_event_groups(event
, ctx
);
1580 perf_event_groups_insert(groups
, event
);
1584 * Delete a group from a tree.
1587 perf_event_groups_delete(struct perf_event_groups
*groups
,
1588 struct perf_event
*event
)
1590 WARN_ON_ONCE(RB_EMPTY_NODE(&event
->group_node
) ||
1591 RB_EMPTY_ROOT(&groups
->tree
));
1593 rb_erase(&event
->group_node
, &groups
->tree
);
1594 init_event_group(event
);
1598 * Helper function to delete event from its groups.
1601 del_event_from_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1603 struct perf_event_groups
*groups
;
1605 groups
= get_event_groups(event
, ctx
);
1606 perf_event_groups_delete(groups
, event
);
1610 * Get the leftmost event in the @cpu subtree.
1612 static struct perf_event
*
1613 perf_event_groups_first(struct perf_event_groups
*groups
, int cpu
)
1615 struct perf_event
*node_event
= NULL
, *match
= NULL
;
1616 struct rb_node
*node
= groups
->tree
.rb_node
;
1619 node_event
= container_of(node
, struct perf_event
, group_node
);
1621 if (cpu
< node_event
->cpu
) {
1622 node
= node
->rb_left
;
1623 } else if (cpu
> node_event
->cpu
) {
1624 node
= node
->rb_right
;
1627 node
= node
->rb_left
;
1635 * Like rb_entry_next_safe() for the @cpu subtree.
1637 static struct perf_event
*
1638 perf_event_groups_next(struct perf_event
*event
)
1640 struct perf_event
*next
;
1642 next
= rb_entry_safe(rb_next(&event
->group_node
), typeof(*event
), group_node
);
1643 if (next
&& next
->cpu
== event
->cpu
)
1650 * Iterate through the whole groups tree.
1652 #define perf_event_groups_for_each(event, groups) \
1653 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1654 typeof(*event), group_node); event; \
1655 event = rb_entry_safe(rb_next(&event->group_node), \
1656 typeof(*event), group_node))
1659 * Add an event from the lists for its context.
1660 * Must be called with ctx->mutex and ctx->lock held.
1663 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1665 lockdep_assert_held(&ctx
->lock
);
1667 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1668 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1670 event
->tstamp
= perf_event_time(event
);
1673 * If we're a stand alone event or group leader, we go to the context
1674 * list, group events are kept attached to the group so that
1675 * perf_group_detach can, at all times, locate all siblings.
1677 if (event
->group_leader
== event
) {
1678 event
->group_caps
= event
->event_caps
;
1679 add_event_to_groups(event
, ctx
);
1682 list_update_cgroup_event(event
, ctx
, true);
1684 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1686 if (event
->attr
.inherit_stat
)
1693 * Initialize event state based on the perf_event_attr::disabled.
1695 static inline void perf_event__state_init(struct perf_event
*event
)
1697 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1698 PERF_EVENT_STATE_INACTIVE
;
1701 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1703 int entry
= sizeof(u64
); /* value */
1707 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1708 size
+= sizeof(u64
);
1710 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1711 size
+= sizeof(u64
);
1713 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1714 entry
+= sizeof(u64
);
1716 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1718 size
+= sizeof(u64
);
1722 event
->read_size
= size
;
1725 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1727 struct perf_sample_data
*data
;
1730 if (sample_type
& PERF_SAMPLE_IP
)
1731 size
+= sizeof(data
->ip
);
1733 if (sample_type
& PERF_SAMPLE_ADDR
)
1734 size
+= sizeof(data
->addr
);
1736 if (sample_type
& PERF_SAMPLE_PERIOD
)
1737 size
+= sizeof(data
->period
);
1739 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1740 size
+= sizeof(data
->weight
);
1742 if (sample_type
& PERF_SAMPLE_READ
)
1743 size
+= event
->read_size
;
1745 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1746 size
+= sizeof(data
->data_src
.val
);
1748 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1749 size
+= sizeof(data
->txn
);
1751 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1752 size
+= sizeof(data
->phys_addr
);
1754 event
->header_size
= size
;
1758 * Called at perf_event creation and when events are attached/detached from a
1761 static void perf_event__header_size(struct perf_event
*event
)
1763 __perf_event_read_size(event
,
1764 event
->group_leader
->nr_siblings
);
1765 __perf_event_header_size(event
, event
->attr
.sample_type
);
1768 static void perf_event__id_header_size(struct perf_event
*event
)
1770 struct perf_sample_data
*data
;
1771 u64 sample_type
= event
->attr
.sample_type
;
1774 if (sample_type
& PERF_SAMPLE_TID
)
1775 size
+= sizeof(data
->tid_entry
);
1777 if (sample_type
& PERF_SAMPLE_TIME
)
1778 size
+= sizeof(data
->time
);
1780 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1781 size
+= sizeof(data
->id
);
1783 if (sample_type
& PERF_SAMPLE_ID
)
1784 size
+= sizeof(data
->id
);
1786 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1787 size
+= sizeof(data
->stream_id
);
1789 if (sample_type
& PERF_SAMPLE_CPU
)
1790 size
+= sizeof(data
->cpu_entry
);
1792 event
->id_header_size
= size
;
1795 static bool perf_event_validate_size(struct perf_event
*event
)
1798 * The values computed here will be over-written when we actually
1801 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1802 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1803 perf_event__id_header_size(event
);
1806 * Sum the lot; should not exceed the 64k limit we have on records.
1807 * Conservative limit to allow for callchains and other variable fields.
1809 if (event
->read_size
+ event
->header_size
+
1810 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1816 static void perf_group_attach(struct perf_event
*event
)
1818 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1820 lockdep_assert_held(&event
->ctx
->lock
);
1823 * We can have double attach due to group movement in perf_event_open.
1825 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1828 event
->attach_state
|= PERF_ATTACH_GROUP
;
1830 if (group_leader
== event
)
1833 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1835 group_leader
->group_caps
&= event
->event_caps
;
1837 list_add_tail(&event
->sibling_list
, &group_leader
->sibling_list
);
1838 group_leader
->nr_siblings
++;
1840 perf_event__header_size(group_leader
);
1842 for_each_sibling_event(pos
, group_leader
)
1843 perf_event__header_size(pos
);
1847 * Remove an event from the lists for its context.
1848 * Must be called with ctx->mutex and ctx->lock held.
1851 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1853 WARN_ON_ONCE(event
->ctx
!= ctx
);
1854 lockdep_assert_held(&ctx
->lock
);
1857 * We can have double detach due to exit/hot-unplug + close.
1859 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1862 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1864 list_update_cgroup_event(event
, ctx
, false);
1867 if (event
->attr
.inherit_stat
)
1870 list_del_rcu(&event
->event_entry
);
1872 if (event
->group_leader
== event
)
1873 del_event_from_groups(event
, ctx
);
1876 * If event was in error state, then keep it
1877 * that way, otherwise bogus counts will be
1878 * returned on read(). The only way to get out
1879 * of error state is by explicit re-enabling
1882 if (event
->state
> PERF_EVENT_STATE_OFF
)
1883 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1888 static void perf_group_detach(struct perf_event
*event
)
1890 struct perf_event
*sibling
, *tmp
;
1891 struct perf_event_context
*ctx
= event
->ctx
;
1893 lockdep_assert_held(&ctx
->lock
);
1896 * We can have double detach due to exit/hot-unplug + close.
1898 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1901 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1904 * If this is a sibling, remove it from its group.
1906 if (event
->group_leader
!= event
) {
1907 list_del_init(&event
->sibling_list
);
1908 event
->group_leader
->nr_siblings
--;
1913 * If this was a group event with sibling events then
1914 * upgrade the siblings to singleton events by adding them
1915 * to whatever list we are on.
1917 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, sibling_list
) {
1919 sibling
->group_leader
= sibling
;
1920 list_del_init(&sibling
->sibling_list
);
1922 /* Inherit group flags from the previous leader */
1923 sibling
->group_caps
= event
->group_caps
;
1925 if (!RB_EMPTY_NODE(&event
->group_node
)) {
1926 add_event_to_groups(sibling
, event
->ctx
);
1928 if (sibling
->state
== PERF_EVENT_STATE_ACTIVE
) {
1929 struct list_head
*list
= sibling
->attr
.pinned
?
1930 &ctx
->pinned_active
: &ctx
->flexible_active
;
1932 list_add_tail(&sibling
->active_list
, list
);
1936 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1940 perf_event__header_size(event
->group_leader
);
1942 for_each_sibling_event(tmp
, event
->group_leader
)
1943 perf_event__header_size(tmp
);
1946 static bool is_orphaned_event(struct perf_event
*event
)
1948 return event
->state
== PERF_EVENT_STATE_DEAD
;
1951 static inline int __pmu_filter_match(struct perf_event
*event
)
1953 struct pmu
*pmu
= event
->pmu
;
1954 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1958 * Check whether we should attempt to schedule an event group based on
1959 * PMU-specific filtering. An event group can consist of HW and SW events,
1960 * potentially with a SW leader, so we must check all the filters, to
1961 * determine whether a group is schedulable:
1963 static inline int pmu_filter_match(struct perf_event
*event
)
1965 struct perf_event
*sibling
;
1967 if (!__pmu_filter_match(event
))
1970 for_each_sibling_event(sibling
, event
) {
1971 if (!__pmu_filter_match(sibling
))
1979 event_filter_match(struct perf_event
*event
)
1981 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1982 perf_cgroup_match(event
) && pmu_filter_match(event
);
1986 event_sched_out(struct perf_event
*event
,
1987 struct perf_cpu_context
*cpuctx
,
1988 struct perf_event_context
*ctx
)
1990 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
1992 WARN_ON_ONCE(event
->ctx
!= ctx
);
1993 lockdep_assert_held(&ctx
->lock
);
1995 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1999 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2000 * we can schedule events _OUT_ individually through things like
2001 * __perf_remove_from_context().
2003 list_del_init(&event
->active_list
);
2005 perf_pmu_disable(event
->pmu
);
2007 event
->pmu
->del(event
, 0);
2010 if (event
->pending_disable
) {
2011 event
->pending_disable
= 0;
2012 state
= PERF_EVENT_STATE_OFF
;
2014 perf_event_set_state(event
, state
);
2016 if (!is_software_event(event
))
2017 cpuctx
->active_oncpu
--;
2018 if (!--ctx
->nr_active
)
2019 perf_event_ctx_deactivate(ctx
);
2020 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2022 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
2023 cpuctx
->exclusive
= 0;
2025 perf_pmu_enable(event
->pmu
);
2029 group_sched_out(struct perf_event
*group_event
,
2030 struct perf_cpu_context
*cpuctx
,
2031 struct perf_event_context
*ctx
)
2033 struct perf_event
*event
;
2035 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2038 perf_pmu_disable(ctx
->pmu
);
2040 event_sched_out(group_event
, cpuctx
, ctx
);
2043 * Schedule out siblings (if any):
2045 for_each_sibling_event(event
, group_event
)
2046 event_sched_out(event
, cpuctx
, ctx
);
2048 perf_pmu_enable(ctx
->pmu
);
2050 if (group_event
->attr
.exclusive
)
2051 cpuctx
->exclusive
= 0;
2054 #define DETACH_GROUP 0x01UL
2057 * Cross CPU call to remove a performance event
2059 * We disable the event on the hardware level first. After that we
2060 * remove it from the context list.
2063 __perf_remove_from_context(struct perf_event
*event
,
2064 struct perf_cpu_context
*cpuctx
,
2065 struct perf_event_context
*ctx
,
2068 unsigned long flags
= (unsigned long)info
;
2070 if (ctx
->is_active
& EVENT_TIME
) {
2071 update_context_time(ctx
);
2072 update_cgrp_time_from_cpuctx(cpuctx
);
2075 event_sched_out(event
, cpuctx
, ctx
);
2076 if (flags
& DETACH_GROUP
)
2077 perf_group_detach(event
);
2078 list_del_event(event
, ctx
);
2080 if (!ctx
->nr_events
&& ctx
->is_active
) {
2083 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2084 cpuctx
->task_ctx
= NULL
;
2090 * Remove the event from a task's (or a CPU's) list of events.
2092 * If event->ctx is a cloned context, callers must make sure that
2093 * every task struct that event->ctx->task could possibly point to
2094 * remains valid. This is OK when called from perf_release since
2095 * that only calls us on the top-level context, which can't be a clone.
2096 * When called from perf_event_exit_task, it's OK because the
2097 * context has been detached from its task.
2099 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
2101 struct perf_event_context
*ctx
= event
->ctx
;
2103 lockdep_assert_held(&ctx
->mutex
);
2105 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
2108 * The above event_function_call() can NO-OP when it hits
2109 * TASK_TOMBSTONE. In that case we must already have been detached
2110 * from the context (by perf_event_exit_event()) but the grouping
2111 * might still be in-tact.
2113 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
2114 if ((flags
& DETACH_GROUP
) &&
2115 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
2117 * Since in that case we cannot possibly be scheduled, simply
2120 raw_spin_lock_irq(&ctx
->lock
);
2121 perf_group_detach(event
);
2122 raw_spin_unlock_irq(&ctx
->lock
);
2127 * Cross CPU call to disable a performance event
2129 static void __perf_event_disable(struct perf_event
*event
,
2130 struct perf_cpu_context
*cpuctx
,
2131 struct perf_event_context
*ctx
,
2134 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
2137 if (ctx
->is_active
& EVENT_TIME
) {
2138 update_context_time(ctx
);
2139 update_cgrp_time_from_event(event
);
2142 if (event
== event
->group_leader
)
2143 group_sched_out(event
, cpuctx
, ctx
);
2145 event_sched_out(event
, cpuctx
, ctx
);
2147 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2153 * If event->ctx is a cloned context, callers must make sure that
2154 * every task struct that event->ctx->task could possibly point to
2155 * remains valid. This condition is satisifed when called through
2156 * perf_event_for_each_child or perf_event_for_each because they
2157 * hold the top-level event's child_mutex, so any descendant that
2158 * goes to exit will block in perf_event_exit_event().
2160 * When called from perf_pending_event it's OK because event->ctx
2161 * is the current context on this CPU and preemption is disabled,
2162 * hence we can't get into perf_event_task_sched_out for this context.
2164 static void _perf_event_disable(struct perf_event
*event
)
2166 struct perf_event_context
*ctx
= event
->ctx
;
2168 raw_spin_lock_irq(&ctx
->lock
);
2169 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2170 raw_spin_unlock_irq(&ctx
->lock
);
2173 raw_spin_unlock_irq(&ctx
->lock
);
2175 event_function_call(event
, __perf_event_disable
, NULL
);
2178 void perf_event_disable_local(struct perf_event
*event
)
2180 event_function_local(event
, __perf_event_disable
, NULL
);
2184 * Strictly speaking kernel users cannot create groups and therefore this
2185 * interface does not need the perf_event_ctx_lock() magic.
2187 void perf_event_disable(struct perf_event
*event
)
2189 struct perf_event_context
*ctx
;
2191 ctx
= perf_event_ctx_lock(event
);
2192 _perf_event_disable(event
);
2193 perf_event_ctx_unlock(event
, ctx
);
2195 EXPORT_SYMBOL_GPL(perf_event_disable
);
2197 void perf_event_disable_inatomic(struct perf_event
*event
)
2199 event
->pending_disable
= 1;
2200 irq_work_queue(&event
->pending
);
2203 static void perf_set_shadow_time(struct perf_event
*event
,
2204 struct perf_event_context
*ctx
)
2207 * use the correct time source for the time snapshot
2209 * We could get by without this by leveraging the
2210 * fact that to get to this function, the caller
2211 * has most likely already called update_context_time()
2212 * and update_cgrp_time_xx() and thus both timestamp
2213 * are identical (or very close). Given that tstamp is,
2214 * already adjusted for cgroup, we could say that:
2215 * tstamp - ctx->timestamp
2217 * tstamp - cgrp->timestamp.
2219 * Then, in perf_output_read(), the calculation would
2220 * work with no changes because:
2221 * - event is guaranteed scheduled in
2222 * - no scheduled out in between
2223 * - thus the timestamp would be the same
2225 * But this is a bit hairy.
2227 * So instead, we have an explicit cgroup call to remain
2228 * within the time time source all along. We believe it
2229 * is cleaner and simpler to understand.
2231 if (is_cgroup_event(event
))
2232 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2234 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2237 #define MAX_INTERRUPTS (~0ULL)
2239 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2240 static void perf_log_itrace_start(struct perf_event
*event
);
2243 event_sched_in(struct perf_event
*event
,
2244 struct perf_cpu_context
*cpuctx
,
2245 struct perf_event_context
*ctx
)
2249 lockdep_assert_held(&ctx
->lock
);
2251 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2254 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2256 * Order event::oncpu write to happen before the ACTIVE state is
2257 * visible. This allows perf_event_{stop,read}() to observe the correct
2258 * ->oncpu if it sees ACTIVE.
2261 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2264 * Unthrottle events, since we scheduled we might have missed several
2265 * ticks already, also for a heavily scheduling task there is little
2266 * guarantee it'll get a tick in a timely manner.
2268 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2269 perf_log_throttle(event
, 1);
2270 event
->hw
.interrupts
= 0;
2273 perf_pmu_disable(event
->pmu
);
2275 perf_set_shadow_time(event
, ctx
);
2277 perf_log_itrace_start(event
);
2279 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2280 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2286 if (!is_software_event(event
))
2287 cpuctx
->active_oncpu
++;
2288 if (!ctx
->nr_active
++)
2289 perf_event_ctx_activate(ctx
);
2290 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2293 if (event
->attr
.exclusive
)
2294 cpuctx
->exclusive
= 1;
2297 perf_pmu_enable(event
->pmu
);
2303 group_sched_in(struct perf_event
*group_event
,
2304 struct perf_cpu_context
*cpuctx
,
2305 struct perf_event_context
*ctx
)
2307 struct perf_event
*event
, *partial_group
= NULL
;
2308 struct pmu
*pmu
= ctx
->pmu
;
2310 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2313 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2315 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2316 pmu
->cancel_txn(pmu
);
2317 perf_mux_hrtimer_restart(cpuctx
);
2322 * Schedule in siblings as one group (if any):
2324 for_each_sibling_event(event
, group_event
) {
2325 if (event_sched_in(event
, cpuctx
, ctx
)) {
2326 partial_group
= event
;
2331 if (!pmu
->commit_txn(pmu
))
2336 * Groups can be scheduled in as one unit only, so undo any
2337 * partial group before returning:
2338 * The events up to the failed event are scheduled out normally.
2340 for_each_sibling_event(event
, group_event
) {
2341 if (event
== partial_group
)
2344 event_sched_out(event
, cpuctx
, ctx
);
2346 event_sched_out(group_event
, cpuctx
, ctx
);
2348 pmu
->cancel_txn(pmu
);
2350 perf_mux_hrtimer_restart(cpuctx
);
2356 * Work out whether we can put this event group on the CPU now.
2358 static int group_can_go_on(struct perf_event
*event
,
2359 struct perf_cpu_context
*cpuctx
,
2363 * Groups consisting entirely of software events can always go on.
2365 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2368 * If an exclusive group is already on, no other hardware
2371 if (cpuctx
->exclusive
)
2374 * If this group is exclusive and there are already
2375 * events on the CPU, it can't go on.
2377 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2380 * Otherwise, try to add it if all previous groups were able
2386 static void add_event_to_ctx(struct perf_event
*event
,
2387 struct perf_event_context
*ctx
)
2389 list_add_event(event
, ctx
);
2390 perf_group_attach(event
);
2393 static void ctx_sched_out(struct perf_event_context
*ctx
,
2394 struct perf_cpu_context
*cpuctx
,
2395 enum event_type_t event_type
);
2397 ctx_sched_in(struct perf_event_context
*ctx
,
2398 struct perf_cpu_context
*cpuctx
,
2399 enum event_type_t event_type
,
2400 struct task_struct
*task
);
2402 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2403 struct perf_event_context
*ctx
,
2404 enum event_type_t event_type
)
2406 if (!cpuctx
->task_ctx
)
2409 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2412 ctx_sched_out(ctx
, cpuctx
, event_type
);
2415 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2416 struct perf_event_context
*ctx
,
2417 struct task_struct
*task
)
2419 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2421 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2422 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2424 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2428 * We want to maintain the following priority of scheduling:
2429 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2430 * - task pinned (EVENT_PINNED)
2431 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2432 * - task flexible (EVENT_FLEXIBLE).
2434 * In order to avoid unscheduling and scheduling back in everything every
2435 * time an event is added, only do it for the groups of equal priority and
2438 * This can be called after a batch operation on task events, in which case
2439 * event_type is a bit mask of the types of events involved. For CPU events,
2440 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2442 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2443 struct perf_event_context
*task_ctx
,
2444 enum event_type_t event_type
)
2446 enum event_type_t ctx_event_type
;
2447 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2450 * If pinned groups are involved, flexible groups also need to be
2453 if (event_type
& EVENT_PINNED
)
2454 event_type
|= EVENT_FLEXIBLE
;
2456 ctx_event_type
= event_type
& EVENT_ALL
;
2458 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2460 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2463 * Decide which cpu ctx groups to schedule out based on the types
2464 * of events that caused rescheduling:
2465 * - EVENT_CPU: schedule out corresponding groups;
2466 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2467 * - otherwise, do nothing more.
2470 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2471 else if (ctx_event_type
& EVENT_PINNED
)
2472 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2474 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2475 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2479 * Cross CPU call to install and enable a performance event
2481 * Very similar to remote_function() + event_function() but cannot assume that
2482 * things like ctx->is_active and cpuctx->task_ctx are set.
2484 static int __perf_install_in_context(void *info
)
2486 struct perf_event
*event
= info
;
2487 struct perf_event_context
*ctx
= event
->ctx
;
2488 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2489 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2490 bool reprogram
= true;
2493 raw_spin_lock(&cpuctx
->ctx
.lock
);
2495 raw_spin_lock(&ctx
->lock
);
2498 reprogram
= (ctx
->task
== current
);
2501 * If the task is running, it must be running on this CPU,
2502 * otherwise we cannot reprogram things.
2504 * If its not running, we don't care, ctx->lock will
2505 * serialize against it becoming runnable.
2507 if (task_curr(ctx
->task
) && !reprogram
) {
2512 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2513 } else if (task_ctx
) {
2514 raw_spin_lock(&task_ctx
->lock
);
2517 #ifdef CONFIG_CGROUP_PERF
2518 if (is_cgroup_event(event
)) {
2520 * If the current cgroup doesn't match the event's
2521 * cgroup, we should not try to schedule it.
2523 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2524 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2525 event
->cgrp
->css
.cgroup
);
2530 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2531 add_event_to_ctx(event
, ctx
);
2532 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2534 add_event_to_ctx(event
, ctx
);
2538 perf_ctx_unlock(cpuctx
, task_ctx
);
2544 * Attach a performance event to a context.
2546 * Very similar to event_function_call, see comment there.
2549 perf_install_in_context(struct perf_event_context
*ctx
,
2550 struct perf_event
*event
,
2553 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2555 lockdep_assert_held(&ctx
->mutex
);
2557 if (event
->cpu
!= -1)
2561 * Ensures that if we can observe event->ctx, both the event and ctx
2562 * will be 'complete'. See perf_iterate_sb_cpu().
2564 smp_store_release(&event
->ctx
, ctx
);
2567 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2572 * Should not happen, we validate the ctx is still alive before calling.
2574 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2578 * Installing events is tricky because we cannot rely on ctx->is_active
2579 * to be set in case this is the nr_events 0 -> 1 transition.
2581 * Instead we use task_curr(), which tells us if the task is running.
2582 * However, since we use task_curr() outside of rq::lock, we can race
2583 * against the actual state. This means the result can be wrong.
2585 * If we get a false positive, we retry, this is harmless.
2587 * If we get a false negative, things are complicated. If we are after
2588 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2589 * value must be correct. If we're before, it doesn't matter since
2590 * perf_event_context_sched_in() will program the counter.
2592 * However, this hinges on the remote context switch having observed
2593 * our task->perf_event_ctxp[] store, such that it will in fact take
2594 * ctx::lock in perf_event_context_sched_in().
2596 * We do this by task_function_call(), if the IPI fails to hit the task
2597 * we know any future context switch of task must see the
2598 * perf_event_ctpx[] store.
2602 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2603 * task_cpu() load, such that if the IPI then does not find the task
2604 * running, a future context switch of that task must observe the
2609 if (!task_function_call(task
, __perf_install_in_context
, event
))
2612 raw_spin_lock_irq(&ctx
->lock
);
2614 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2616 * Cannot happen because we already checked above (which also
2617 * cannot happen), and we hold ctx->mutex, which serializes us
2618 * against perf_event_exit_task_context().
2620 raw_spin_unlock_irq(&ctx
->lock
);
2624 * If the task is not running, ctx->lock will avoid it becoming so,
2625 * thus we can safely install the event.
2627 if (task_curr(task
)) {
2628 raw_spin_unlock_irq(&ctx
->lock
);
2631 add_event_to_ctx(event
, ctx
);
2632 raw_spin_unlock_irq(&ctx
->lock
);
2636 * Cross CPU call to enable a performance event
2638 static void __perf_event_enable(struct perf_event
*event
,
2639 struct perf_cpu_context
*cpuctx
,
2640 struct perf_event_context
*ctx
,
2643 struct perf_event
*leader
= event
->group_leader
;
2644 struct perf_event_context
*task_ctx
;
2646 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2647 event
->state
<= PERF_EVENT_STATE_ERROR
)
2651 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2653 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2655 if (!ctx
->is_active
)
2658 if (!event_filter_match(event
)) {
2659 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2664 * If the event is in a group and isn't the group leader,
2665 * then don't put it on unless the group is on.
2667 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2668 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2672 task_ctx
= cpuctx
->task_ctx
;
2674 WARN_ON_ONCE(task_ctx
!= ctx
);
2676 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2682 * If event->ctx is a cloned context, callers must make sure that
2683 * every task struct that event->ctx->task could possibly point to
2684 * remains valid. This condition is satisfied when called through
2685 * perf_event_for_each_child or perf_event_for_each as described
2686 * for perf_event_disable.
2688 static void _perf_event_enable(struct perf_event
*event
)
2690 struct perf_event_context
*ctx
= event
->ctx
;
2692 raw_spin_lock_irq(&ctx
->lock
);
2693 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2694 event
->state
< PERF_EVENT_STATE_ERROR
) {
2695 raw_spin_unlock_irq(&ctx
->lock
);
2700 * If the event is in error state, clear that first.
2702 * That way, if we see the event in error state below, we know that it
2703 * has gone back into error state, as distinct from the task having
2704 * been scheduled away before the cross-call arrived.
2706 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2707 event
->state
= PERF_EVENT_STATE_OFF
;
2708 raw_spin_unlock_irq(&ctx
->lock
);
2710 event_function_call(event
, __perf_event_enable
, NULL
);
2714 * See perf_event_disable();
2716 void perf_event_enable(struct perf_event
*event
)
2718 struct perf_event_context
*ctx
;
2720 ctx
= perf_event_ctx_lock(event
);
2721 _perf_event_enable(event
);
2722 perf_event_ctx_unlock(event
, ctx
);
2724 EXPORT_SYMBOL_GPL(perf_event_enable
);
2726 struct stop_event_data
{
2727 struct perf_event
*event
;
2728 unsigned int restart
;
2731 static int __perf_event_stop(void *info
)
2733 struct stop_event_data
*sd
= info
;
2734 struct perf_event
*event
= sd
->event
;
2736 /* if it's already INACTIVE, do nothing */
2737 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2740 /* matches smp_wmb() in event_sched_in() */
2744 * There is a window with interrupts enabled before we get here,
2745 * so we need to check again lest we try to stop another CPU's event.
2747 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2750 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2753 * May race with the actual stop (through perf_pmu_output_stop()),
2754 * but it is only used for events with AUX ring buffer, and such
2755 * events will refuse to restart because of rb::aux_mmap_count==0,
2756 * see comments in perf_aux_output_begin().
2758 * Since this is happening on an event-local CPU, no trace is lost
2762 event
->pmu
->start(event
, 0);
2767 static int perf_event_stop(struct perf_event
*event
, int restart
)
2769 struct stop_event_data sd
= {
2776 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2779 /* matches smp_wmb() in event_sched_in() */
2783 * We only want to restart ACTIVE events, so if the event goes
2784 * inactive here (event->oncpu==-1), there's nothing more to do;
2785 * fall through with ret==-ENXIO.
2787 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2788 __perf_event_stop
, &sd
);
2789 } while (ret
== -EAGAIN
);
2795 * In order to contain the amount of racy and tricky in the address filter
2796 * configuration management, it is a two part process:
2798 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2799 * we update the addresses of corresponding vmas in
2800 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2801 * (p2) when an event is scheduled in (pmu::add), it calls
2802 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2803 * if the generation has changed since the previous call.
2805 * If (p1) happens while the event is active, we restart it to force (p2).
2807 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2808 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2810 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2811 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2813 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2816 void perf_event_addr_filters_sync(struct perf_event
*event
)
2818 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2820 if (!has_addr_filter(event
))
2823 raw_spin_lock(&ifh
->lock
);
2824 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2825 event
->pmu
->addr_filters_sync(event
);
2826 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2828 raw_spin_unlock(&ifh
->lock
);
2830 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2832 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2835 * not supported on inherited events
2837 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2840 atomic_add(refresh
, &event
->event_limit
);
2841 _perf_event_enable(event
);
2847 * See perf_event_disable()
2849 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2851 struct perf_event_context
*ctx
;
2854 ctx
= perf_event_ctx_lock(event
);
2855 ret
= _perf_event_refresh(event
, refresh
);
2856 perf_event_ctx_unlock(event
, ctx
);
2860 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2862 static int perf_event_modify_breakpoint(struct perf_event
*bp
,
2863 struct perf_event_attr
*attr
)
2867 _perf_event_disable(bp
);
2869 err
= modify_user_hw_breakpoint_check(bp
, attr
, true);
2871 if (!bp
->attr
.disabled
)
2872 _perf_event_enable(bp
);
2877 static int perf_event_modify_attr(struct perf_event
*event
,
2878 struct perf_event_attr
*attr
)
2880 if (event
->attr
.type
!= attr
->type
)
2883 switch (event
->attr
.type
) {
2884 case PERF_TYPE_BREAKPOINT
:
2885 return perf_event_modify_breakpoint(event
, attr
);
2887 /* Place holder for future additions. */
2892 static void ctx_sched_out(struct perf_event_context
*ctx
,
2893 struct perf_cpu_context
*cpuctx
,
2894 enum event_type_t event_type
)
2896 struct perf_event
*event
, *tmp
;
2897 int is_active
= ctx
->is_active
;
2899 lockdep_assert_held(&ctx
->lock
);
2901 if (likely(!ctx
->nr_events
)) {
2903 * See __perf_remove_from_context().
2905 WARN_ON_ONCE(ctx
->is_active
);
2907 WARN_ON_ONCE(cpuctx
->task_ctx
);
2911 ctx
->is_active
&= ~event_type
;
2912 if (!(ctx
->is_active
& EVENT_ALL
))
2916 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2917 if (!ctx
->is_active
)
2918 cpuctx
->task_ctx
= NULL
;
2922 * Always update time if it was set; not only when it changes.
2923 * Otherwise we can 'forget' to update time for any but the last
2924 * context we sched out. For example:
2926 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2927 * ctx_sched_out(.event_type = EVENT_PINNED)
2929 * would only update time for the pinned events.
2931 if (is_active
& EVENT_TIME
) {
2932 /* update (and stop) ctx time */
2933 update_context_time(ctx
);
2934 update_cgrp_time_from_cpuctx(cpuctx
);
2937 is_active
^= ctx
->is_active
; /* changed bits */
2939 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2942 perf_pmu_disable(ctx
->pmu
);
2943 if (is_active
& EVENT_PINNED
) {
2944 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_active
, active_list
)
2945 group_sched_out(event
, cpuctx
, ctx
);
2948 if (is_active
& EVENT_FLEXIBLE
) {
2949 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_active
, active_list
)
2950 group_sched_out(event
, cpuctx
, ctx
);
2952 perf_pmu_enable(ctx
->pmu
);
2956 * Test whether two contexts are equivalent, i.e. whether they have both been
2957 * cloned from the same version of the same context.
2959 * Equivalence is measured using a generation number in the context that is
2960 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2961 * and list_del_event().
2963 static int context_equiv(struct perf_event_context
*ctx1
,
2964 struct perf_event_context
*ctx2
)
2966 lockdep_assert_held(&ctx1
->lock
);
2967 lockdep_assert_held(&ctx2
->lock
);
2969 /* Pinning disables the swap optimization */
2970 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2973 /* If ctx1 is the parent of ctx2 */
2974 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2977 /* If ctx2 is the parent of ctx1 */
2978 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2982 * If ctx1 and ctx2 have the same parent; we flatten the parent
2983 * hierarchy, see perf_event_init_context().
2985 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2986 ctx1
->parent_gen
== ctx2
->parent_gen
)
2993 static void __perf_event_sync_stat(struct perf_event
*event
,
2994 struct perf_event
*next_event
)
2998 if (!event
->attr
.inherit_stat
)
3002 * Update the event value, we cannot use perf_event_read()
3003 * because we're in the middle of a context switch and have IRQs
3004 * disabled, which upsets smp_call_function_single(), however
3005 * we know the event must be on the current CPU, therefore we
3006 * don't need to use it.
3008 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3009 event
->pmu
->read(event
);
3011 perf_event_update_time(event
);
3014 * In order to keep per-task stats reliable we need to flip the event
3015 * values when we flip the contexts.
3017 value
= local64_read(&next_event
->count
);
3018 value
= local64_xchg(&event
->count
, value
);
3019 local64_set(&next_event
->count
, value
);
3021 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
3022 swap(event
->total_time_running
, next_event
->total_time_running
);
3025 * Since we swizzled the values, update the user visible data too.
3027 perf_event_update_userpage(event
);
3028 perf_event_update_userpage(next_event
);
3031 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
3032 struct perf_event_context
*next_ctx
)
3034 struct perf_event
*event
, *next_event
;
3039 update_context_time(ctx
);
3041 event
= list_first_entry(&ctx
->event_list
,
3042 struct perf_event
, event_entry
);
3044 next_event
= list_first_entry(&next_ctx
->event_list
,
3045 struct perf_event
, event_entry
);
3047 while (&event
->event_entry
!= &ctx
->event_list
&&
3048 &next_event
->event_entry
!= &next_ctx
->event_list
) {
3050 __perf_event_sync_stat(event
, next_event
);
3052 event
= list_next_entry(event
, event_entry
);
3053 next_event
= list_next_entry(next_event
, event_entry
);
3057 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
3058 struct task_struct
*next
)
3060 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
3061 struct perf_event_context
*next_ctx
;
3062 struct perf_event_context
*parent
, *next_parent
;
3063 struct perf_cpu_context
*cpuctx
;
3069 cpuctx
= __get_cpu_context(ctx
);
3070 if (!cpuctx
->task_ctx
)
3074 next_ctx
= next
->perf_event_ctxp
[ctxn
];
3078 parent
= rcu_dereference(ctx
->parent_ctx
);
3079 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
3081 /* If neither context have a parent context; they cannot be clones. */
3082 if (!parent
&& !next_parent
)
3085 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
3087 * Looks like the two contexts are clones, so we might be
3088 * able to optimize the context switch. We lock both
3089 * contexts and check that they are clones under the
3090 * lock (including re-checking that neither has been
3091 * uncloned in the meantime). It doesn't matter which
3092 * order we take the locks because no other cpu could
3093 * be trying to lock both of these tasks.
3095 raw_spin_lock(&ctx
->lock
);
3096 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3097 if (context_equiv(ctx
, next_ctx
)) {
3098 WRITE_ONCE(ctx
->task
, next
);
3099 WRITE_ONCE(next_ctx
->task
, task
);
3101 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3104 * RCU_INIT_POINTER here is safe because we've not
3105 * modified the ctx and the above modification of
3106 * ctx->task and ctx->task_ctx_data are immaterial
3107 * since those values are always verified under
3108 * ctx->lock which we're now holding.
3110 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3111 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3115 perf_event_sync_stat(ctx
, next_ctx
);
3117 raw_spin_unlock(&next_ctx
->lock
);
3118 raw_spin_unlock(&ctx
->lock
);
3124 raw_spin_lock(&ctx
->lock
);
3125 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3126 raw_spin_unlock(&ctx
->lock
);
3130 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3132 void perf_sched_cb_dec(struct pmu
*pmu
)
3134 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3136 this_cpu_dec(perf_sched_cb_usages
);
3138 if (!--cpuctx
->sched_cb_usage
)
3139 list_del(&cpuctx
->sched_cb_entry
);
3143 void perf_sched_cb_inc(struct pmu
*pmu
)
3145 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3147 if (!cpuctx
->sched_cb_usage
++)
3148 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3150 this_cpu_inc(perf_sched_cb_usages
);
3154 * This function provides the context switch callback to the lower code
3155 * layer. It is invoked ONLY when the context switch callback is enabled.
3157 * This callback is relevant even to per-cpu events; for example multi event
3158 * PEBS requires this to provide PID/TID information. This requires we flush
3159 * all queued PEBS records before we context switch to a new task.
3161 static void perf_pmu_sched_task(struct task_struct
*prev
,
3162 struct task_struct
*next
,
3165 struct perf_cpu_context
*cpuctx
;
3171 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3172 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3174 if (WARN_ON_ONCE(!pmu
->sched_task
))
3177 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3178 perf_pmu_disable(pmu
);
3180 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3182 perf_pmu_enable(pmu
);
3183 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3187 static void perf_event_switch(struct task_struct
*task
,
3188 struct task_struct
*next_prev
, bool sched_in
);
3190 #define for_each_task_context_nr(ctxn) \
3191 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3194 * Called from scheduler to remove the events of the current task,
3195 * with interrupts disabled.
3197 * We stop each event and update the event value in event->count.
3199 * This does not protect us against NMI, but disable()
3200 * sets the disabled bit in the control field of event _before_
3201 * accessing the event control register. If a NMI hits, then it will
3202 * not restart the event.
3204 void __perf_event_task_sched_out(struct task_struct
*task
,
3205 struct task_struct
*next
)
3209 if (__this_cpu_read(perf_sched_cb_usages
))
3210 perf_pmu_sched_task(task
, next
, false);
3212 if (atomic_read(&nr_switch_events
))
3213 perf_event_switch(task
, next
, false);
3215 for_each_task_context_nr(ctxn
)
3216 perf_event_context_sched_out(task
, ctxn
, next
);
3219 * if cgroup events exist on this CPU, then we need
3220 * to check if we have to switch out PMU state.
3221 * cgroup event are system-wide mode only
3223 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3224 perf_cgroup_sched_out(task
, next
);
3228 * Called with IRQs disabled
3230 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3231 enum event_type_t event_type
)
3233 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3236 static int visit_groups_merge(struct perf_event_groups
*groups
, int cpu
,
3237 int (*func
)(struct perf_event
*, void *), void *data
)
3239 struct perf_event
**evt
, *evt1
, *evt2
;
3242 evt1
= perf_event_groups_first(groups
, -1);
3243 evt2
= perf_event_groups_first(groups
, cpu
);
3245 while (evt1
|| evt2
) {
3247 if (evt1
->group_index
< evt2
->group_index
)
3257 ret
= func(*evt
, data
);
3261 *evt
= perf_event_groups_next(*evt
);
3267 struct sched_in_data
{
3268 struct perf_event_context
*ctx
;
3269 struct perf_cpu_context
*cpuctx
;
3273 static int pinned_sched_in(struct perf_event
*event
, void *data
)
3275 struct sched_in_data
*sid
= data
;
3277 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3280 if (!event_filter_match(event
))
3283 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3284 if (!group_sched_in(event
, sid
->cpuctx
, sid
->ctx
))
3285 list_add_tail(&event
->active_list
, &sid
->ctx
->pinned_active
);
3289 * If this pinned group hasn't been scheduled,
3290 * put it in error state.
3292 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3293 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3298 static int flexible_sched_in(struct perf_event
*event
, void *data
)
3300 struct sched_in_data
*sid
= data
;
3302 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3305 if (!event_filter_match(event
))
3308 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3309 if (!group_sched_in(event
, sid
->cpuctx
, sid
->ctx
))
3310 list_add_tail(&event
->active_list
, &sid
->ctx
->flexible_active
);
3312 sid
->can_add_hw
= 0;
3319 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3320 struct perf_cpu_context
*cpuctx
)
3322 struct sched_in_data sid
= {
3328 visit_groups_merge(&ctx
->pinned_groups
,
3330 pinned_sched_in
, &sid
);
3334 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3335 struct perf_cpu_context
*cpuctx
)
3337 struct sched_in_data sid
= {
3343 visit_groups_merge(&ctx
->flexible_groups
,
3345 flexible_sched_in
, &sid
);
3349 ctx_sched_in(struct perf_event_context
*ctx
,
3350 struct perf_cpu_context
*cpuctx
,
3351 enum event_type_t event_type
,
3352 struct task_struct
*task
)
3354 int is_active
= ctx
->is_active
;
3357 lockdep_assert_held(&ctx
->lock
);
3359 if (likely(!ctx
->nr_events
))
3362 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3365 cpuctx
->task_ctx
= ctx
;
3367 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3370 is_active
^= ctx
->is_active
; /* changed bits */
3372 if (is_active
& EVENT_TIME
) {
3373 /* start ctx time */
3375 ctx
->timestamp
= now
;
3376 perf_cgroup_set_timestamp(task
, ctx
);
3380 * First go through the list and put on any pinned groups
3381 * in order to give them the best chance of going on.
3383 if (is_active
& EVENT_PINNED
)
3384 ctx_pinned_sched_in(ctx
, cpuctx
);
3386 /* Then walk through the lower prio flexible groups */
3387 if (is_active
& EVENT_FLEXIBLE
)
3388 ctx_flexible_sched_in(ctx
, cpuctx
);
3391 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3392 enum event_type_t event_type
,
3393 struct task_struct
*task
)
3395 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3397 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3400 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3401 struct task_struct
*task
)
3403 struct perf_cpu_context
*cpuctx
;
3405 cpuctx
= __get_cpu_context(ctx
);
3406 if (cpuctx
->task_ctx
== ctx
)
3409 perf_ctx_lock(cpuctx
, ctx
);
3411 * We must check ctx->nr_events while holding ctx->lock, such
3412 * that we serialize against perf_install_in_context().
3414 if (!ctx
->nr_events
)
3417 perf_pmu_disable(ctx
->pmu
);
3419 * We want to keep the following priority order:
3420 * cpu pinned (that don't need to move), task pinned,
3421 * cpu flexible, task flexible.
3423 * However, if task's ctx is not carrying any pinned
3424 * events, no need to flip the cpuctx's events around.
3426 if (!RB_EMPTY_ROOT(&ctx
->pinned_groups
.tree
))
3427 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3428 perf_event_sched_in(cpuctx
, ctx
, task
);
3429 perf_pmu_enable(ctx
->pmu
);
3432 perf_ctx_unlock(cpuctx
, ctx
);
3436 * Called from scheduler to add the events of the current task
3437 * with interrupts disabled.
3439 * We restore the event value and then enable it.
3441 * This does not protect us against NMI, but enable()
3442 * sets the enabled bit in the control field of event _before_
3443 * accessing the event control register. If a NMI hits, then it will
3444 * keep the event running.
3446 void __perf_event_task_sched_in(struct task_struct
*prev
,
3447 struct task_struct
*task
)
3449 struct perf_event_context
*ctx
;
3453 * If cgroup events exist on this CPU, then we need to check if we have
3454 * to switch in PMU state; cgroup event are system-wide mode only.
3456 * Since cgroup events are CPU events, we must schedule these in before
3457 * we schedule in the task events.
3459 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3460 perf_cgroup_sched_in(prev
, task
);
3462 for_each_task_context_nr(ctxn
) {
3463 ctx
= task
->perf_event_ctxp
[ctxn
];
3467 perf_event_context_sched_in(ctx
, task
);
3470 if (atomic_read(&nr_switch_events
))
3471 perf_event_switch(task
, prev
, true);
3473 if (__this_cpu_read(perf_sched_cb_usages
))
3474 perf_pmu_sched_task(prev
, task
, true);
3477 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3479 u64 frequency
= event
->attr
.sample_freq
;
3480 u64 sec
= NSEC_PER_SEC
;
3481 u64 divisor
, dividend
;
3483 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3485 count_fls
= fls64(count
);
3486 nsec_fls
= fls64(nsec
);
3487 frequency_fls
= fls64(frequency
);
3491 * We got @count in @nsec, with a target of sample_freq HZ
3492 * the target period becomes:
3495 * period = -------------------
3496 * @nsec * sample_freq
3501 * Reduce accuracy by one bit such that @a and @b converge
3502 * to a similar magnitude.
3504 #define REDUCE_FLS(a, b) \
3506 if (a##_fls > b##_fls) { \
3516 * Reduce accuracy until either term fits in a u64, then proceed with
3517 * the other, so that finally we can do a u64/u64 division.
3519 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3520 REDUCE_FLS(nsec
, frequency
);
3521 REDUCE_FLS(sec
, count
);
3524 if (count_fls
+ sec_fls
> 64) {
3525 divisor
= nsec
* frequency
;
3527 while (count_fls
+ sec_fls
> 64) {
3528 REDUCE_FLS(count
, sec
);
3532 dividend
= count
* sec
;
3534 dividend
= count
* sec
;
3536 while (nsec_fls
+ frequency_fls
> 64) {
3537 REDUCE_FLS(nsec
, frequency
);
3541 divisor
= nsec
* frequency
;
3547 return div64_u64(dividend
, divisor
);
3550 static DEFINE_PER_CPU(int, perf_throttled_count
);
3551 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3553 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3555 struct hw_perf_event
*hwc
= &event
->hw
;
3556 s64 period
, sample_period
;
3559 period
= perf_calculate_period(event
, nsec
, count
);
3561 delta
= (s64
)(period
- hwc
->sample_period
);
3562 delta
= (delta
+ 7) / 8; /* low pass filter */
3564 sample_period
= hwc
->sample_period
+ delta
;
3569 hwc
->sample_period
= sample_period
;
3571 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3573 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3575 local64_set(&hwc
->period_left
, 0);
3578 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3583 * combine freq adjustment with unthrottling to avoid two passes over the
3584 * events. At the same time, make sure, having freq events does not change
3585 * the rate of unthrottling as that would introduce bias.
3587 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3590 struct perf_event
*event
;
3591 struct hw_perf_event
*hwc
;
3592 u64 now
, period
= TICK_NSEC
;
3596 * only need to iterate over all events iff:
3597 * - context have events in frequency mode (needs freq adjust)
3598 * - there are events to unthrottle on this cpu
3600 if (!(ctx
->nr_freq
|| needs_unthr
))
3603 raw_spin_lock(&ctx
->lock
);
3604 perf_pmu_disable(ctx
->pmu
);
3606 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3607 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3610 if (!event_filter_match(event
))
3613 perf_pmu_disable(event
->pmu
);
3617 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3618 hwc
->interrupts
= 0;
3619 perf_log_throttle(event
, 1);
3620 event
->pmu
->start(event
, 0);
3623 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3627 * stop the event and update event->count
3629 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3631 now
= local64_read(&event
->count
);
3632 delta
= now
- hwc
->freq_count_stamp
;
3633 hwc
->freq_count_stamp
= now
;
3637 * reload only if value has changed
3638 * we have stopped the event so tell that
3639 * to perf_adjust_period() to avoid stopping it
3643 perf_adjust_period(event
, period
, delta
, false);
3645 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3647 perf_pmu_enable(event
->pmu
);
3650 perf_pmu_enable(ctx
->pmu
);
3651 raw_spin_unlock(&ctx
->lock
);
3655 * Move @event to the tail of the @ctx's elegible events.
3657 static void rotate_ctx(struct perf_event_context
*ctx
, struct perf_event
*event
)
3660 * Rotate the first entry last of non-pinned groups. Rotation might be
3661 * disabled by the inheritance code.
3663 if (ctx
->rotate_disable
)
3666 perf_event_groups_delete(&ctx
->flexible_groups
, event
);
3667 perf_event_groups_insert(&ctx
->flexible_groups
, event
);
3670 static inline struct perf_event
*
3671 ctx_first_active(struct perf_event_context
*ctx
)
3673 return list_first_entry_or_null(&ctx
->flexible_active
,
3674 struct perf_event
, active_list
);
3677 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3679 struct perf_event
*cpu_event
= NULL
, *task_event
= NULL
;
3680 bool cpu_rotate
= false, task_rotate
= false;
3681 struct perf_event_context
*ctx
= NULL
;
3684 * Since we run this from IRQ context, nobody can install new
3685 * events, thus the event count values are stable.
3688 if (cpuctx
->ctx
.nr_events
) {
3689 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3693 ctx
= cpuctx
->task_ctx
;
3694 if (ctx
&& ctx
->nr_events
) {
3695 if (ctx
->nr_events
!= ctx
->nr_active
)
3699 if (!(cpu_rotate
|| task_rotate
))
3702 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3703 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3706 task_event
= ctx_first_active(ctx
);
3708 cpu_event
= ctx_first_active(&cpuctx
->ctx
);
3711 * As per the order given at ctx_resched() first 'pop' task flexible
3712 * and then, if needed CPU flexible.
3714 if (task_event
|| (ctx
&& cpu_event
))
3715 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3717 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3720 rotate_ctx(ctx
, task_event
);
3722 rotate_ctx(&cpuctx
->ctx
, cpu_event
);
3724 perf_event_sched_in(cpuctx
, ctx
, current
);
3726 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3727 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3732 void perf_event_task_tick(void)
3734 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3735 struct perf_event_context
*ctx
, *tmp
;
3738 lockdep_assert_irqs_disabled();
3740 __this_cpu_inc(perf_throttled_seq
);
3741 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3742 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3744 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3745 perf_adjust_freq_unthr_context(ctx
, throttled
);
3748 static int event_enable_on_exec(struct perf_event
*event
,
3749 struct perf_event_context
*ctx
)
3751 if (!event
->attr
.enable_on_exec
)
3754 event
->attr
.enable_on_exec
= 0;
3755 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3758 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3764 * Enable all of a task's events that have been marked enable-on-exec.
3765 * This expects task == current.
3767 static void perf_event_enable_on_exec(int ctxn
)
3769 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3770 enum event_type_t event_type
= 0;
3771 struct perf_cpu_context
*cpuctx
;
3772 struct perf_event
*event
;
3773 unsigned long flags
;
3776 local_irq_save(flags
);
3777 ctx
= current
->perf_event_ctxp
[ctxn
];
3778 if (!ctx
|| !ctx
->nr_events
)
3781 cpuctx
= __get_cpu_context(ctx
);
3782 perf_ctx_lock(cpuctx
, ctx
);
3783 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3784 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3785 enabled
|= event_enable_on_exec(event
, ctx
);
3786 event_type
|= get_event_type(event
);
3790 * Unclone and reschedule this context if we enabled any event.
3793 clone_ctx
= unclone_ctx(ctx
);
3794 ctx_resched(cpuctx
, ctx
, event_type
);
3796 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3798 perf_ctx_unlock(cpuctx
, ctx
);
3801 local_irq_restore(flags
);
3807 struct perf_read_data
{
3808 struct perf_event
*event
;
3813 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3815 u16 local_pkg
, event_pkg
;
3817 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3818 int local_cpu
= smp_processor_id();
3820 event_pkg
= topology_physical_package_id(event_cpu
);
3821 local_pkg
= topology_physical_package_id(local_cpu
);
3823 if (event_pkg
== local_pkg
)
3831 * Cross CPU call to read the hardware event
3833 static void __perf_event_read(void *info
)
3835 struct perf_read_data
*data
= info
;
3836 struct perf_event
*sub
, *event
= data
->event
;
3837 struct perf_event_context
*ctx
= event
->ctx
;
3838 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3839 struct pmu
*pmu
= event
->pmu
;
3842 * If this is a task context, we need to check whether it is
3843 * the current task context of this cpu. If not it has been
3844 * scheduled out before the smp call arrived. In that case
3845 * event->count would have been updated to a recent sample
3846 * when the event was scheduled out.
3848 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3851 raw_spin_lock(&ctx
->lock
);
3852 if (ctx
->is_active
& EVENT_TIME
) {
3853 update_context_time(ctx
);
3854 update_cgrp_time_from_event(event
);
3857 perf_event_update_time(event
);
3859 perf_event_update_sibling_time(event
);
3861 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3870 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3874 for_each_sibling_event(sub
, event
) {
3875 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3877 * Use sibling's PMU rather than @event's since
3878 * sibling could be on different (eg: software) PMU.
3880 sub
->pmu
->read(sub
);
3884 data
->ret
= pmu
->commit_txn(pmu
);
3887 raw_spin_unlock(&ctx
->lock
);
3890 static inline u64
perf_event_count(struct perf_event
*event
)
3892 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3896 * NMI-safe method to read a local event, that is an event that
3898 * - either for the current task, or for this CPU
3899 * - does not have inherit set, for inherited task events
3900 * will not be local and we cannot read them atomically
3901 * - must not have a pmu::count method
3903 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
3904 u64
*enabled
, u64
*running
)
3906 unsigned long flags
;
3910 * Disabling interrupts avoids all counter scheduling (context
3911 * switches, timer based rotation and IPIs).
3913 local_irq_save(flags
);
3916 * It must not be an event with inherit set, we cannot read
3917 * all child counters from atomic context.
3919 if (event
->attr
.inherit
) {
3924 /* If this is a per-task event, it must be for current */
3925 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3926 event
->hw
.target
!= current
) {
3931 /* If this is a per-CPU event, it must be for this CPU */
3932 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3933 event
->cpu
!= smp_processor_id()) {
3938 /* If this is a pinned event it must be running on this CPU */
3939 if (event
->attr
.pinned
&& event
->oncpu
!= smp_processor_id()) {
3945 * If the event is currently on this CPU, its either a per-task event,
3946 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3949 if (event
->oncpu
== smp_processor_id())
3950 event
->pmu
->read(event
);
3952 *value
= local64_read(&event
->count
);
3953 if (enabled
|| running
) {
3954 u64 now
= event
->shadow_ctx_time
+ perf_clock();
3955 u64 __enabled
, __running
;
3957 __perf_update_times(event
, now
, &__enabled
, &__running
);
3959 *enabled
= __enabled
;
3961 *running
= __running
;
3964 local_irq_restore(flags
);
3969 static int perf_event_read(struct perf_event
*event
, bool group
)
3971 enum perf_event_state state
= READ_ONCE(event
->state
);
3972 int event_cpu
, ret
= 0;
3975 * If event is enabled and currently active on a CPU, update the
3976 * value in the event structure:
3979 if (state
== PERF_EVENT_STATE_ACTIVE
) {
3980 struct perf_read_data data
;
3983 * Orders the ->state and ->oncpu loads such that if we see
3984 * ACTIVE we must also see the right ->oncpu.
3986 * Matches the smp_wmb() from event_sched_in().
3990 event_cpu
= READ_ONCE(event
->oncpu
);
3991 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3994 data
= (struct perf_read_data
){
4001 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
4004 * Purposely ignore the smp_call_function_single() return
4007 * If event_cpu isn't a valid CPU it means the event got
4008 * scheduled out and that will have updated the event count.
4010 * Therefore, either way, we'll have an up-to-date event count
4013 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
4017 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
4018 struct perf_event_context
*ctx
= event
->ctx
;
4019 unsigned long flags
;
4021 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4022 state
= event
->state
;
4023 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
4024 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4029 * May read while context is not active (e.g., thread is
4030 * blocked), in that case we cannot update context time
4032 if (ctx
->is_active
& EVENT_TIME
) {
4033 update_context_time(ctx
);
4034 update_cgrp_time_from_event(event
);
4037 perf_event_update_time(event
);
4039 perf_event_update_sibling_time(event
);
4040 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4047 * Initialize the perf_event context in a task_struct:
4049 static void __perf_event_init_context(struct perf_event_context
*ctx
)
4051 raw_spin_lock_init(&ctx
->lock
);
4052 mutex_init(&ctx
->mutex
);
4053 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
4054 perf_event_groups_init(&ctx
->pinned_groups
);
4055 perf_event_groups_init(&ctx
->flexible_groups
);
4056 INIT_LIST_HEAD(&ctx
->event_list
);
4057 INIT_LIST_HEAD(&ctx
->pinned_active
);
4058 INIT_LIST_HEAD(&ctx
->flexible_active
);
4059 atomic_set(&ctx
->refcount
, 1);
4062 static struct perf_event_context
*
4063 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
4065 struct perf_event_context
*ctx
;
4067 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
4071 __perf_event_init_context(ctx
);
4074 get_task_struct(task
);
4081 static struct task_struct
*
4082 find_lively_task_by_vpid(pid_t vpid
)
4084 struct task_struct
*task
;
4090 task
= find_task_by_vpid(vpid
);
4092 get_task_struct(task
);
4096 return ERR_PTR(-ESRCH
);
4102 * Returns a matching context with refcount and pincount.
4104 static struct perf_event_context
*
4105 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
4106 struct perf_event
*event
)
4108 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4109 struct perf_cpu_context
*cpuctx
;
4110 void *task_ctx_data
= NULL
;
4111 unsigned long flags
;
4113 int cpu
= event
->cpu
;
4116 /* Must be root to operate on a CPU event: */
4117 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
4118 return ERR_PTR(-EACCES
);
4120 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
4129 ctxn
= pmu
->task_ctx_nr
;
4133 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
4134 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
4135 if (!task_ctx_data
) {
4142 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
4144 clone_ctx
= unclone_ctx(ctx
);
4147 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
4148 ctx
->task_ctx_data
= task_ctx_data
;
4149 task_ctx_data
= NULL
;
4151 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4156 ctx
= alloc_perf_context(pmu
, task
);
4161 if (task_ctx_data
) {
4162 ctx
->task_ctx_data
= task_ctx_data
;
4163 task_ctx_data
= NULL
;
4167 mutex_lock(&task
->perf_event_mutex
);
4169 * If it has already passed perf_event_exit_task().
4170 * we must see PF_EXITING, it takes this mutex too.
4172 if (task
->flags
& PF_EXITING
)
4174 else if (task
->perf_event_ctxp
[ctxn
])
4179 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
4181 mutex_unlock(&task
->perf_event_mutex
);
4183 if (unlikely(err
)) {
4192 kfree(task_ctx_data
);
4196 kfree(task_ctx_data
);
4197 return ERR_PTR(err
);
4200 static void perf_event_free_filter(struct perf_event
*event
);
4201 static void perf_event_free_bpf_prog(struct perf_event
*event
);
4203 static void free_event_rcu(struct rcu_head
*head
)
4205 struct perf_event
*event
;
4207 event
= container_of(head
, struct perf_event
, rcu_head
);
4209 put_pid_ns(event
->ns
);
4210 perf_event_free_filter(event
);
4214 static void ring_buffer_attach(struct perf_event
*event
,
4215 struct ring_buffer
*rb
);
4217 static void detach_sb_event(struct perf_event
*event
)
4219 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4221 raw_spin_lock(&pel
->lock
);
4222 list_del_rcu(&event
->sb_list
);
4223 raw_spin_unlock(&pel
->lock
);
4226 static bool is_sb_event(struct perf_event
*event
)
4228 struct perf_event_attr
*attr
= &event
->attr
;
4233 if (event
->attach_state
& PERF_ATTACH_TASK
)
4236 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4237 attr
->comm
|| attr
->comm_exec
||
4239 attr
->context_switch
)
4244 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4246 if (is_sb_event(event
))
4247 detach_sb_event(event
);
4250 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4255 if (is_cgroup_event(event
))
4256 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4259 #ifdef CONFIG_NO_HZ_FULL
4260 static DEFINE_SPINLOCK(nr_freq_lock
);
4263 static void unaccount_freq_event_nohz(void)
4265 #ifdef CONFIG_NO_HZ_FULL
4266 spin_lock(&nr_freq_lock
);
4267 if (atomic_dec_and_test(&nr_freq_events
))
4268 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4269 spin_unlock(&nr_freq_lock
);
4273 static void unaccount_freq_event(void)
4275 if (tick_nohz_full_enabled())
4276 unaccount_freq_event_nohz();
4278 atomic_dec(&nr_freq_events
);
4281 static void unaccount_event(struct perf_event
*event
)
4288 if (event
->attach_state
& PERF_ATTACH_TASK
)
4290 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4291 atomic_dec(&nr_mmap_events
);
4292 if (event
->attr
.comm
)
4293 atomic_dec(&nr_comm_events
);
4294 if (event
->attr
.namespaces
)
4295 atomic_dec(&nr_namespaces_events
);
4296 if (event
->attr
.task
)
4297 atomic_dec(&nr_task_events
);
4298 if (event
->attr
.freq
)
4299 unaccount_freq_event();
4300 if (event
->attr
.context_switch
) {
4302 atomic_dec(&nr_switch_events
);
4304 if (is_cgroup_event(event
))
4306 if (has_branch_stack(event
))
4310 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4311 schedule_delayed_work(&perf_sched_work
, HZ
);
4314 unaccount_event_cpu(event
, event
->cpu
);
4316 unaccount_pmu_sb_event(event
);
4319 static void perf_sched_delayed(struct work_struct
*work
)
4321 mutex_lock(&perf_sched_mutex
);
4322 if (atomic_dec_and_test(&perf_sched_count
))
4323 static_branch_disable(&perf_sched_events
);
4324 mutex_unlock(&perf_sched_mutex
);
4328 * The following implement mutual exclusion of events on "exclusive" pmus
4329 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4330 * at a time, so we disallow creating events that might conflict, namely:
4332 * 1) cpu-wide events in the presence of per-task events,
4333 * 2) per-task events in the presence of cpu-wide events,
4334 * 3) two matching events on the same context.
4336 * The former two cases are handled in the allocation path (perf_event_alloc(),
4337 * _free_event()), the latter -- before the first perf_install_in_context().
4339 static int exclusive_event_init(struct perf_event
*event
)
4341 struct pmu
*pmu
= event
->pmu
;
4343 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4347 * Prevent co-existence of per-task and cpu-wide events on the
4348 * same exclusive pmu.
4350 * Negative pmu::exclusive_cnt means there are cpu-wide
4351 * events on this "exclusive" pmu, positive means there are
4354 * Since this is called in perf_event_alloc() path, event::ctx
4355 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4356 * to mean "per-task event", because unlike other attach states it
4357 * never gets cleared.
4359 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4360 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4363 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4370 static void exclusive_event_destroy(struct perf_event
*event
)
4372 struct pmu
*pmu
= event
->pmu
;
4374 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4377 /* see comment in exclusive_event_init() */
4378 if (event
->attach_state
& PERF_ATTACH_TASK
)
4379 atomic_dec(&pmu
->exclusive_cnt
);
4381 atomic_inc(&pmu
->exclusive_cnt
);
4384 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4386 if ((e1
->pmu
== e2
->pmu
) &&
4387 (e1
->cpu
== e2
->cpu
||
4394 /* Called under the same ctx::mutex as perf_install_in_context() */
4395 static bool exclusive_event_installable(struct perf_event
*event
,
4396 struct perf_event_context
*ctx
)
4398 struct perf_event
*iter_event
;
4399 struct pmu
*pmu
= event
->pmu
;
4401 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4404 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4405 if (exclusive_event_match(iter_event
, event
))
4412 static void perf_addr_filters_splice(struct perf_event
*event
,
4413 struct list_head
*head
);
4415 static void _free_event(struct perf_event
*event
)
4417 irq_work_sync(&event
->pending
);
4419 unaccount_event(event
);
4423 * Can happen when we close an event with re-directed output.
4425 * Since we have a 0 refcount, perf_mmap_close() will skip
4426 * over us; possibly making our ring_buffer_put() the last.
4428 mutex_lock(&event
->mmap_mutex
);
4429 ring_buffer_attach(event
, NULL
);
4430 mutex_unlock(&event
->mmap_mutex
);
4433 if (is_cgroup_event(event
))
4434 perf_detach_cgroup(event
);
4436 if (!event
->parent
) {
4437 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4438 put_callchain_buffers();
4441 perf_event_free_bpf_prog(event
);
4442 perf_addr_filters_splice(event
, NULL
);
4443 kfree(event
->addr_filters_offs
);
4446 event
->destroy(event
);
4449 put_ctx(event
->ctx
);
4451 if (event
->hw
.target
)
4452 put_task_struct(event
->hw
.target
);
4454 exclusive_event_destroy(event
);
4455 module_put(event
->pmu
->module
);
4457 call_rcu(&event
->rcu_head
, free_event_rcu
);
4461 * Used to free events which have a known refcount of 1, such as in error paths
4462 * where the event isn't exposed yet and inherited events.
4464 static void free_event(struct perf_event
*event
)
4466 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4467 "unexpected event refcount: %ld; ptr=%p\n",
4468 atomic_long_read(&event
->refcount
), event
)) {
4469 /* leak to avoid use-after-free */
4477 * Remove user event from the owner task.
4479 static void perf_remove_from_owner(struct perf_event
*event
)
4481 struct task_struct
*owner
;
4485 * Matches the smp_store_release() in perf_event_exit_task(). If we
4486 * observe !owner it means the list deletion is complete and we can
4487 * indeed free this event, otherwise we need to serialize on
4488 * owner->perf_event_mutex.
4490 owner
= READ_ONCE(event
->owner
);
4493 * Since delayed_put_task_struct() also drops the last
4494 * task reference we can safely take a new reference
4495 * while holding the rcu_read_lock().
4497 get_task_struct(owner
);
4503 * If we're here through perf_event_exit_task() we're already
4504 * holding ctx->mutex which would be an inversion wrt. the
4505 * normal lock order.
4507 * However we can safely take this lock because its the child
4510 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4513 * We have to re-check the event->owner field, if it is cleared
4514 * we raced with perf_event_exit_task(), acquiring the mutex
4515 * ensured they're done, and we can proceed with freeing the
4519 list_del_init(&event
->owner_entry
);
4520 smp_store_release(&event
->owner
, NULL
);
4522 mutex_unlock(&owner
->perf_event_mutex
);
4523 put_task_struct(owner
);
4527 static void put_event(struct perf_event
*event
)
4529 if (!atomic_long_dec_and_test(&event
->refcount
))
4536 * Kill an event dead; while event:refcount will preserve the event
4537 * object, it will not preserve its functionality. Once the last 'user'
4538 * gives up the object, we'll destroy the thing.
4540 int perf_event_release_kernel(struct perf_event
*event
)
4542 struct perf_event_context
*ctx
= event
->ctx
;
4543 struct perf_event
*child
, *tmp
;
4544 LIST_HEAD(free_list
);
4547 * If we got here through err_file: fput(event_file); we will not have
4548 * attached to a context yet.
4551 WARN_ON_ONCE(event
->attach_state
&
4552 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4556 if (!is_kernel_event(event
))
4557 perf_remove_from_owner(event
);
4559 ctx
= perf_event_ctx_lock(event
);
4560 WARN_ON_ONCE(ctx
->parent_ctx
);
4561 perf_remove_from_context(event
, DETACH_GROUP
);
4563 raw_spin_lock_irq(&ctx
->lock
);
4565 * Mark this event as STATE_DEAD, there is no external reference to it
4568 * Anybody acquiring event->child_mutex after the below loop _must_
4569 * also see this, most importantly inherit_event() which will avoid
4570 * placing more children on the list.
4572 * Thus this guarantees that we will in fact observe and kill _ALL_
4575 event
->state
= PERF_EVENT_STATE_DEAD
;
4576 raw_spin_unlock_irq(&ctx
->lock
);
4578 perf_event_ctx_unlock(event
, ctx
);
4581 mutex_lock(&event
->child_mutex
);
4582 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4585 * Cannot change, child events are not migrated, see the
4586 * comment with perf_event_ctx_lock_nested().
4588 ctx
= READ_ONCE(child
->ctx
);
4590 * Since child_mutex nests inside ctx::mutex, we must jump
4591 * through hoops. We start by grabbing a reference on the ctx.
4593 * Since the event cannot get freed while we hold the
4594 * child_mutex, the context must also exist and have a !0
4600 * Now that we have a ctx ref, we can drop child_mutex, and
4601 * acquire ctx::mutex without fear of it going away. Then we
4602 * can re-acquire child_mutex.
4604 mutex_unlock(&event
->child_mutex
);
4605 mutex_lock(&ctx
->mutex
);
4606 mutex_lock(&event
->child_mutex
);
4609 * Now that we hold ctx::mutex and child_mutex, revalidate our
4610 * state, if child is still the first entry, it didn't get freed
4611 * and we can continue doing so.
4613 tmp
= list_first_entry_or_null(&event
->child_list
,
4614 struct perf_event
, child_list
);
4616 perf_remove_from_context(child
, DETACH_GROUP
);
4617 list_move(&child
->child_list
, &free_list
);
4619 * This matches the refcount bump in inherit_event();
4620 * this can't be the last reference.
4625 mutex_unlock(&event
->child_mutex
);
4626 mutex_unlock(&ctx
->mutex
);
4630 mutex_unlock(&event
->child_mutex
);
4632 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4633 list_del(&child
->child_list
);
4638 put_event(event
); /* Must be the 'last' reference */
4641 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4644 * Called when the last reference to the file is gone.
4646 static int perf_release(struct inode
*inode
, struct file
*file
)
4648 perf_event_release_kernel(file
->private_data
);
4652 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4654 struct perf_event
*child
;
4660 mutex_lock(&event
->child_mutex
);
4662 (void)perf_event_read(event
, false);
4663 total
+= perf_event_count(event
);
4665 *enabled
+= event
->total_time_enabled
+
4666 atomic64_read(&event
->child_total_time_enabled
);
4667 *running
+= event
->total_time_running
+
4668 atomic64_read(&event
->child_total_time_running
);
4670 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4671 (void)perf_event_read(child
, false);
4672 total
+= perf_event_count(child
);
4673 *enabled
+= child
->total_time_enabled
;
4674 *running
+= child
->total_time_running
;
4676 mutex_unlock(&event
->child_mutex
);
4681 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4683 struct perf_event_context
*ctx
;
4686 ctx
= perf_event_ctx_lock(event
);
4687 count
= __perf_event_read_value(event
, enabled
, running
);
4688 perf_event_ctx_unlock(event
, ctx
);
4692 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4694 static int __perf_read_group_add(struct perf_event
*leader
,
4695 u64 read_format
, u64
*values
)
4697 struct perf_event_context
*ctx
= leader
->ctx
;
4698 struct perf_event
*sub
;
4699 unsigned long flags
;
4700 int n
= 1; /* skip @nr */
4703 ret
= perf_event_read(leader
, true);
4707 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4710 * Since we co-schedule groups, {enabled,running} times of siblings
4711 * will be identical to those of the leader, so we only publish one
4714 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4715 values
[n
++] += leader
->total_time_enabled
+
4716 atomic64_read(&leader
->child_total_time_enabled
);
4719 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4720 values
[n
++] += leader
->total_time_running
+
4721 atomic64_read(&leader
->child_total_time_running
);
4725 * Write {count,id} tuples for every sibling.
4727 values
[n
++] += perf_event_count(leader
);
4728 if (read_format
& PERF_FORMAT_ID
)
4729 values
[n
++] = primary_event_id(leader
);
4731 for_each_sibling_event(sub
, leader
) {
4732 values
[n
++] += perf_event_count(sub
);
4733 if (read_format
& PERF_FORMAT_ID
)
4734 values
[n
++] = primary_event_id(sub
);
4737 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4741 static int perf_read_group(struct perf_event
*event
,
4742 u64 read_format
, char __user
*buf
)
4744 struct perf_event
*leader
= event
->group_leader
, *child
;
4745 struct perf_event_context
*ctx
= leader
->ctx
;
4749 lockdep_assert_held(&ctx
->mutex
);
4751 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4755 values
[0] = 1 + leader
->nr_siblings
;
4758 * By locking the child_mutex of the leader we effectively
4759 * lock the child list of all siblings.. XXX explain how.
4761 mutex_lock(&leader
->child_mutex
);
4763 ret
= __perf_read_group_add(leader
, read_format
, values
);
4767 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4768 ret
= __perf_read_group_add(child
, read_format
, values
);
4773 mutex_unlock(&leader
->child_mutex
);
4775 ret
= event
->read_size
;
4776 if (copy_to_user(buf
, values
, event
->read_size
))
4781 mutex_unlock(&leader
->child_mutex
);
4787 static int perf_read_one(struct perf_event
*event
,
4788 u64 read_format
, char __user
*buf
)
4790 u64 enabled
, running
;
4794 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4795 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4796 values
[n
++] = enabled
;
4797 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4798 values
[n
++] = running
;
4799 if (read_format
& PERF_FORMAT_ID
)
4800 values
[n
++] = primary_event_id(event
);
4802 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4805 return n
* sizeof(u64
);
4808 static bool is_event_hup(struct perf_event
*event
)
4812 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4815 mutex_lock(&event
->child_mutex
);
4816 no_children
= list_empty(&event
->child_list
);
4817 mutex_unlock(&event
->child_mutex
);
4822 * Read the performance event - simple non blocking version for now
4825 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4827 u64 read_format
= event
->attr
.read_format
;
4831 * Return end-of-file for a read on an event that is in
4832 * error state (i.e. because it was pinned but it couldn't be
4833 * scheduled on to the CPU at some point).
4835 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4838 if (count
< event
->read_size
)
4841 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4842 if (read_format
& PERF_FORMAT_GROUP
)
4843 ret
= perf_read_group(event
, read_format
, buf
);
4845 ret
= perf_read_one(event
, read_format
, buf
);
4851 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4853 struct perf_event
*event
= file
->private_data
;
4854 struct perf_event_context
*ctx
;
4857 ctx
= perf_event_ctx_lock(event
);
4858 ret
= __perf_read(event
, buf
, count
);
4859 perf_event_ctx_unlock(event
, ctx
);
4864 static __poll_t
perf_poll(struct file
*file
, poll_table
*wait
)
4866 struct perf_event
*event
= file
->private_data
;
4867 struct ring_buffer
*rb
;
4868 __poll_t events
= EPOLLHUP
;
4870 poll_wait(file
, &event
->waitq
, wait
);
4872 if (is_event_hup(event
))
4876 * Pin the event->rb by taking event->mmap_mutex; otherwise
4877 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4879 mutex_lock(&event
->mmap_mutex
);
4882 events
= atomic_xchg(&rb
->poll
, 0);
4883 mutex_unlock(&event
->mmap_mutex
);
4887 static void _perf_event_reset(struct perf_event
*event
)
4889 (void)perf_event_read(event
, false);
4890 local64_set(&event
->count
, 0);
4891 perf_event_update_userpage(event
);
4895 * Holding the top-level event's child_mutex means that any
4896 * descendant process that has inherited this event will block
4897 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4898 * task existence requirements of perf_event_enable/disable.
4900 static void perf_event_for_each_child(struct perf_event
*event
,
4901 void (*func
)(struct perf_event
*))
4903 struct perf_event
*child
;
4905 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4907 mutex_lock(&event
->child_mutex
);
4909 list_for_each_entry(child
, &event
->child_list
, child_list
)
4911 mutex_unlock(&event
->child_mutex
);
4914 static void perf_event_for_each(struct perf_event
*event
,
4915 void (*func
)(struct perf_event
*))
4917 struct perf_event_context
*ctx
= event
->ctx
;
4918 struct perf_event
*sibling
;
4920 lockdep_assert_held(&ctx
->mutex
);
4922 event
= event
->group_leader
;
4924 perf_event_for_each_child(event
, func
);
4925 for_each_sibling_event(sibling
, event
)
4926 perf_event_for_each_child(sibling
, func
);
4929 static void __perf_event_period(struct perf_event
*event
,
4930 struct perf_cpu_context
*cpuctx
,
4931 struct perf_event_context
*ctx
,
4934 u64 value
= *((u64
*)info
);
4937 if (event
->attr
.freq
) {
4938 event
->attr
.sample_freq
= value
;
4940 event
->attr
.sample_period
= value
;
4941 event
->hw
.sample_period
= value
;
4944 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4946 perf_pmu_disable(ctx
->pmu
);
4948 * We could be throttled; unthrottle now to avoid the tick
4949 * trying to unthrottle while we already re-started the event.
4951 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4952 event
->hw
.interrupts
= 0;
4953 perf_log_throttle(event
, 1);
4955 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4958 local64_set(&event
->hw
.period_left
, 0);
4961 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4962 perf_pmu_enable(ctx
->pmu
);
4966 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4970 if (!is_sampling_event(event
))
4973 if (copy_from_user(&value
, arg
, sizeof(value
)))
4979 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4982 event_function_call(event
, __perf_event_period
, &value
);
4987 static const struct file_operations perf_fops
;
4989 static inline int perf_fget_light(int fd
, struct fd
*p
)
4991 struct fd f
= fdget(fd
);
4995 if (f
.file
->f_op
!= &perf_fops
) {
5003 static int perf_event_set_output(struct perf_event
*event
,
5004 struct perf_event
*output_event
);
5005 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
5006 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
5007 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5008 struct perf_event_attr
*attr
);
5010 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
5012 void (*func
)(struct perf_event
*);
5016 case PERF_EVENT_IOC_ENABLE
:
5017 func
= _perf_event_enable
;
5019 case PERF_EVENT_IOC_DISABLE
:
5020 func
= _perf_event_disable
;
5022 case PERF_EVENT_IOC_RESET
:
5023 func
= _perf_event_reset
;
5026 case PERF_EVENT_IOC_REFRESH
:
5027 return _perf_event_refresh(event
, arg
);
5029 case PERF_EVENT_IOC_PERIOD
:
5030 return perf_event_period(event
, (u64 __user
*)arg
);
5032 case PERF_EVENT_IOC_ID
:
5034 u64 id
= primary_event_id(event
);
5036 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
5041 case PERF_EVENT_IOC_SET_OUTPUT
:
5045 struct perf_event
*output_event
;
5047 ret
= perf_fget_light(arg
, &output
);
5050 output_event
= output
.file
->private_data
;
5051 ret
= perf_event_set_output(event
, output_event
);
5054 ret
= perf_event_set_output(event
, NULL
);
5059 case PERF_EVENT_IOC_SET_FILTER
:
5060 return perf_event_set_filter(event
, (void __user
*)arg
);
5062 case PERF_EVENT_IOC_SET_BPF
:
5063 return perf_event_set_bpf_prog(event
, arg
);
5065 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
5066 struct ring_buffer
*rb
;
5069 rb
= rcu_dereference(event
->rb
);
5070 if (!rb
|| !rb
->nr_pages
) {
5074 rb_toggle_paused(rb
, !!arg
);
5079 case PERF_EVENT_IOC_QUERY_BPF
:
5080 return perf_event_query_prog_array(event
, (void __user
*)arg
);
5082 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES
: {
5083 struct perf_event_attr new_attr
;
5084 int err
= perf_copy_attr((struct perf_event_attr __user
*)arg
,
5090 return perf_event_modify_attr(event
, &new_attr
);
5096 if (flags
& PERF_IOC_FLAG_GROUP
)
5097 perf_event_for_each(event
, func
);
5099 perf_event_for_each_child(event
, func
);
5104 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
5106 struct perf_event
*event
= file
->private_data
;
5107 struct perf_event_context
*ctx
;
5110 ctx
= perf_event_ctx_lock(event
);
5111 ret
= _perf_ioctl(event
, cmd
, arg
);
5112 perf_event_ctx_unlock(event
, ctx
);
5117 #ifdef CONFIG_COMPAT
5118 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
5121 switch (_IOC_NR(cmd
)) {
5122 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
5123 case _IOC_NR(PERF_EVENT_IOC_ID
):
5124 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF
):
5125 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES
):
5126 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5127 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
5128 cmd
&= ~IOCSIZE_MASK
;
5129 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
5133 return perf_ioctl(file
, cmd
, arg
);
5136 # define perf_compat_ioctl NULL
5139 int perf_event_task_enable(void)
5141 struct perf_event_context
*ctx
;
5142 struct perf_event
*event
;
5144 mutex_lock(¤t
->perf_event_mutex
);
5145 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5146 ctx
= perf_event_ctx_lock(event
);
5147 perf_event_for_each_child(event
, _perf_event_enable
);
5148 perf_event_ctx_unlock(event
, ctx
);
5150 mutex_unlock(¤t
->perf_event_mutex
);
5155 int perf_event_task_disable(void)
5157 struct perf_event_context
*ctx
;
5158 struct perf_event
*event
;
5160 mutex_lock(¤t
->perf_event_mutex
);
5161 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5162 ctx
= perf_event_ctx_lock(event
);
5163 perf_event_for_each_child(event
, _perf_event_disable
);
5164 perf_event_ctx_unlock(event
, ctx
);
5166 mutex_unlock(¤t
->perf_event_mutex
);
5171 static int perf_event_index(struct perf_event
*event
)
5173 if (event
->hw
.state
& PERF_HES_STOPPED
)
5176 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5179 return event
->pmu
->event_idx(event
);
5182 static void calc_timer_values(struct perf_event
*event
,
5189 *now
= perf_clock();
5190 ctx_time
= event
->shadow_ctx_time
+ *now
;
5191 __perf_update_times(event
, ctx_time
, enabled
, running
);
5194 static void perf_event_init_userpage(struct perf_event
*event
)
5196 struct perf_event_mmap_page
*userpg
;
5197 struct ring_buffer
*rb
;
5200 rb
= rcu_dereference(event
->rb
);
5204 userpg
= rb
->user_page
;
5206 /* Allow new userspace to detect that bit 0 is deprecated */
5207 userpg
->cap_bit0_is_deprecated
= 1;
5208 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
5209 userpg
->data_offset
= PAGE_SIZE
;
5210 userpg
->data_size
= perf_data_size(rb
);
5216 void __weak
arch_perf_update_userpage(
5217 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
5222 * Callers need to ensure there can be no nesting of this function, otherwise
5223 * the seqlock logic goes bad. We can not serialize this because the arch
5224 * code calls this from NMI context.
5226 void perf_event_update_userpage(struct perf_event
*event
)
5228 struct perf_event_mmap_page
*userpg
;
5229 struct ring_buffer
*rb
;
5230 u64 enabled
, running
, now
;
5233 rb
= rcu_dereference(event
->rb
);
5238 * compute total_time_enabled, total_time_running
5239 * based on snapshot values taken when the event
5240 * was last scheduled in.
5242 * we cannot simply called update_context_time()
5243 * because of locking issue as we can be called in
5246 calc_timer_values(event
, &now
, &enabled
, &running
);
5248 userpg
= rb
->user_page
;
5250 * Disable preemption to guarantee consistent time stamps are stored to
5256 userpg
->index
= perf_event_index(event
);
5257 userpg
->offset
= perf_event_count(event
);
5259 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5261 userpg
->time_enabled
= enabled
+
5262 atomic64_read(&event
->child_total_time_enabled
);
5264 userpg
->time_running
= running
+
5265 atomic64_read(&event
->child_total_time_running
);
5267 arch_perf_update_userpage(event
, userpg
, now
);
5275 EXPORT_SYMBOL_GPL(perf_event_update_userpage
);
5277 static vm_fault_t
perf_mmap_fault(struct vm_fault
*vmf
)
5279 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5280 struct ring_buffer
*rb
;
5281 vm_fault_t ret
= VM_FAULT_SIGBUS
;
5283 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5284 if (vmf
->pgoff
== 0)
5290 rb
= rcu_dereference(event
->rb
);
5294 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5297 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5301 get_page(vmf
->page
);
5302 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5303 vmf
->page
->index
= vmf
->pgoff
;
5312 static void ring_buffer_attach(struct perf_event
*event
,
5313 struct ring_buffer
*rb
)
5315 struct ring_buffer
*old_rb
= NULL
;
5316 unsigned long flags
;
5320 * Should be impossible, we set this when removing
5321 * event->rb_entry and wait/clear when adding event->rb_entry.
5323 WARN_ON_ONCE(event
->rcu_pending
);
5326 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5327 list_del_rcu(&event
->rb_entry
);
5328 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5330 event
->rcu_batches
= get_state_synchronize_rcu();
5331 event
->rcu_pending
= 1;
5335 if (event
->rcu_pending
) {
5336 cond_synchronize_rcu(event
->rcu_batches
);
5337 event
->rcu_pending
= 0;
5340 spin_lock_irqsave(&rb
->event_lock
, flags
);
5341 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5342 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5346 * Avoid racing with perf_mmap_close(AUX): stop the event
5347 * before swizzling the event::rb pointer; if it's getting
5348 * unmapped, its aux_mmap_count will be 0 and it won't
5349 * restart. See the comment in __perf_pmu_output_stop().
5351 * Data will inevitably be lost when set_output is done in
5352 * mid-air, but then again, whoever does it like this is
5353 * not in for the data anyway.
5356 perf_event_stop(event
, 0);
5358 rcu_assign_pointer(event
->rb
, rb
);
5361 ring_buffer_put(old_rb
);
5363 * Since we detached before setting the new rb, so that we
5364 * could attach the new rb, we could have missed a wakeup.
5367 wake_up_all(&event
->waitq
);
5371 static void ring_buffer_wakeup(struct perf_event
*event
)
5373 struct ring_buffer
*rb
;
5376 rb
= rcu_dereference(event
->rb
);
5378 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5379 wake_up_all(&event
->waitq
);
5384 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5386 struct ring_buffer
*rb
;
5389 rb
= rcu_dereference(event
->rb
);
5391 if (!atomic_inc_not_zero(&rb
->refcount
))
5399 void ring_buffer_put(struct ring_buffer
*rb
)
5401 if (!atomic_dec_and_test(&rb
->refcount
))
5404 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5406 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5409 static void perf_mmap_open(struct vm_area_struct
*vma
)
5411 struct perf_event
*event
= vma
->vm_file
->private_data
;
5413 atomic_inc(&event
->mmap_count
);
5414 atomic_inc(&event
->rb
->mmap_count
);
5417 atomic_inc(&event
->rb
->aux_mmap_count
);
5419 if (event
->pmu
->event_mapped
)
5420 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5423 static void perf_pmu_output_stop(struct perf_event
*event
);
5426 * A buffer can be mmap()ed multiple times; either directly through the same
5427 * event, or through other events by use of perf_event_set_output().
5429 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5430 * the buffer here, where we still have a VM context. This means we need
5431 * to detach all events redirecting to us.
5433 static void perf_mmap_close(struct vm_area_struct
*vma
)
5435 struct perf_event
*event
= vma
->vm_file
->private_data
;
5437 struct ring_buffer
*rb
= ring_buffer_get(event
);
5438 struct user_struct
*mmap_user
= rb
->mmap_user
;
5439 int mmap_locked
= rb
->mmap_locked
;
5440 unsigned long size
= perf_data_size(rb
);
5442 if (event
->pmu
->event_unmapped
)
5443 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5446 * rb->aux_mmap_count will always drop before rb->mmap_count and
5447 * event->mmap_count, so it is ok to use event->mmap_mutex to
5448 * serialize with perf_mmap here.
5450 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5451 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5453 * Stop all AUX events that are writing to this buffer,
5454 * so that we can free its AUX pages and corresponding PMU
5455 * data. Note that after rb::aux_mmap_count dropped to zero,
5456 * they won't start any more (see perf_aux_output_begin()).
5458 perf_pmu_output_stop(event
);
5460 /* now it's safe to free the pages */
5461 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5462 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5464 /* this has to be the last one */
5466 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5468 mutex_unlock(&event
->mmap_mutex
);
5471 atomic_dec(&rb
->mmap_count
);
5473 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5476 ring_buffer_attach(event
, NULL
);
5477 mutex_unlock(&event
->mmap_mutex
);
5479 /* If there's still other mmap()s of this buffer, we're done. */
5480 if (atomic_read(&rb
->mmap_count
))
5484 * No other mmap()s, detach from all other events that might redirect
5485 * into the now unreachable buffer. Somewhat complicated by the
5486 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5490 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5491 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5493 * This event is en-route to free_event() which will
5494 * detach it and remove it from the list.
5500 mutex_lock(&event
->mmap_mutex
);
5502 * Check we didn't race with perf_event_set_output() which can
5503 * swizzle the rb from under us while we were waiting to
5504 * acquire mmap_mutex.
5506 * If we find a different rb; ignore this event, a next
5507 * iteration will no longer find it on the list. We have to
5508 * still restart the iteration to make sure we're not now
5509 * iterating the wrong list.
5511 if (event
->rb
== rb
)
5512 ring_buffer_attach(event
, NULL
);
5514 mutex_unlock(&event
->mmap_mutex
);
5518 * Restart the iteration; either we're on the wrong list or
5519 * destroyed its integrity by doing a deletion.
5526 * It could be there's still a few 0-ref events on the list; they'll
5527 * get cleaned up by free_event() -- they'll also still have their
5528 * ref on the rb and will free it whenever they are done with it.
5530 * Aside from that, this buffer is 'fully' detached and unmapped,
5531 * undo the VM accounting.
5534 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5535 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5536 free_uid(mmap_user
);
5539 ring_buffer_put(rb
); /* could be last */
5542 static const struct vm_operations_struct perf_mmap_vmops
= {
5543 .open
= perf_mmap_open
,
5544 .close
= perf_mmap_close
, /* non mergeable */
5545 .fault
= perf_mmap_fault
,
5546 .page_mkwrite
= perf_mmap_fault
,
5549 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5551 struct perf_event
*event
= file
->private_data
;
5552 unsigned long user_locked
, user_lock_limit
;
5553 struct user_struct
*user
= current_user();
5554 unsigned long locked
, lock_limit
;
5555 struct ring_buffer
*rb
= NULL
;
5556 unsigned long vma_size
;
5557 unsigned long nr_pages
;
5558 long user_extra
= 0, extra
= 0;
5559 int ret
= 0, flags
= 0;
5562 * Don't allow mmap() of inherited per-task counters. This would
5563 * create a performance issue due to all children writing to the
5566 if (event
->cpu
== -1 && event
->attr
.inherit
)
5569 if (!(vma
->vm_flags
& VM_SHARED
))
5572 vma_size
= vma
->vm_end
- vma
->vm_start
;
5574 if (vma
->vm_pgoff
== 0) {
5575 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5578 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5579 * mapped, all subsequent mappings should have the same size
5580 * and offset. Must be above the normal perf buffer.
5582 u64 aux_offset
, aux_size
;
5587 nr_pages
= vma_size
/ PAGE_SIZE
;
5589 mutex_lock(&event
->mmap_mutex
);
5596 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5597 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5599 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5602 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5605 /* already mapped with a different offset */
5606 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5609 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5612 /* already mapped with a different size */
5613 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5616 if (!is_power_of_2(nr_pages
))
5619 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5622 if (rb_has_aux(rb
)) {
5623 atomic_inc(&rb
->aux_mmap_count
);
5628 atomic_set(&rb
->aux_mmap_count
, 1);
5629 user_extra
= nr_pages
;
5635 * If we have rb pages ensure they're a power-of-two number, so we
5636 * can do bitmasks instead of modulo.
5638 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5641 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5644 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5646 mutex_lock(&event
->mmap_mutex
);
5648 if (event
->rb
->nr_pages
!= nr_pages
) {
5653 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5655 * Raced against perf_mmap_close() through
5656 * perf_event_set_output(). Try again, hope for better
5659 mutex_unlock(&event
->mmap_mutex
);
5666 user_extra
= nr_pages
+ 1;
5669 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5672 * Increase the limit linearly with more CPUs:
5674 user_lock_limit
*= num_online_cpus();
5676 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5678 if (user_locked
> user_lock_limit
)
5679 extra
= user_locked
- user_lock_limit
;
5681 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5682 lock_limit
>>= PAGE_SHIFT
;
5683 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5685 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5686 !capable(CAP_IPC_LOCK
)) {
5691 WARN_ON(!rb
&& event
->rb
);
5693 if (vma
->vm_flags
& VM_WRITE
)
5694 flags
|= RING_BUFFER_WRITABLE
;
5697 rb
= rb_alloc(nr_pages
,
5698 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5706 atomic_set(&rb
->mmap_count
, 1);
5707 rb
->mmap_user
= get_current_user();
5708 rb
->mmap_locked
= extra
;
5710 ring_buffer_attach(event
, rb
);
5712 perf_event_init_userpage(event
);
5713 perf_event_update_userpage(event
);
5715 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5716 event
->attr
.aux_watermark
, flags
);
5718 rb
->aux_mmap_locked
= extra
;
5723 atomic_long_add(user_extra
, &user
->locked_vm
);
5724 vma
->vm_mm
->pinned_vm
+= extra
;
5726 atomic_inc(&event
->mmap_count
);
5728 atomic_dec(&rb
->mmap_count
);
5731 mutex_unlock(&event
->mmap_mutex
);
5734 * Since pinned accounting is per vm we cannot allow fork() to copy our
5737 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5738 vma
->vm_ops
= &perf_mmap_vmops
;
5740 if (event
->pmu
->event_mapped
)
5741 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5746 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5748 struct inode
*inode
= file_inode(filp
);
5749 struct perf_event
*event
= filp
->private_data
;
5753 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5754 inode_unlock(inode
);
5762 static const struct file_operations perf_fops
= {
5763 .llseek
= no_llseek
,
5764 .release
= perf_release
,
5767 .unlocked_ioctl
= perf_ioctl
,
5768 .compat_ioctl
= perf_compat_ioctl
,
5770 .fasync
= perf_fasync
,
5776 * If there's data, ensure we set the poll() state and publish everything
5777 * to user-space before waking everybody up.
5780 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5782 /* only the parent has fasync state */
5784 event
= event
->parent
;
5785 return &event
->fasync
;
5788 void perf_event_wakeup(struct perf_event
*event
)
5790 ring_buffer_wakeup(event
);
5792 if (event
->pending_kill
) {
5793 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5794 event
->pending_kill
= 0;
5798 static void perf_pending_event(struct irq_work
*entry
)
5800 struct perf_event
*event
= container_of(entry
,
5801 struct perf_event
, pending
);
5804 rctx
= perf_swevent_get_recursion_context();
5806 * If we 'fail' here, that's OK, it means recursion is already disabled
5807 * and we won't recurse 'further'.
5810 if (event
->pending_disable
) {
5811 event
->pending_disable
= 0;
5812 perf_event_disable_local(event
);
5815 if (event
->pending_wakeup
) {
5816 event
->pending_wakeup
= 0;
5817 perf_event_wakeup(event
);
5821 perf_swevent_put_recursion_context(rctx
);
5825 * We assume there is only KVM supporting the callbacks.
5826 * Later on, we might change it to a list if there is
5827 * another virtualization implementation supporting the callbacks.
5829 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5831 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5833 perf_guest_cbs
= cbs
;
5836 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5838 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5840 perf_guest_cbs
= NULL
;
5843 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5846 perf_output_sample_regs(struct perf_output_handle
*handle
,
5847 struct pt_regs
*regs
, u64 mask
)
5850 DECLARE_BITMAP(_mask
, 64);
5852 bitmap_from_u64(_mask
, mask
);
5853 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5856 val
= perf_reg_value(regs
, bit
);
5857 perf_output_put(handle
, val
);
5861 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5862 struct pt_regs
*regs
,
5863 struct pt_regs
*regs_user_copy
)
5865 if (user_mode(regs
)) {
5866 regs_user
->abi
= perf_reg_abi(current
);
5867 regs_user
->regs
= regs
;
5868 } else if (current
->mm
) {
5869 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5871 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5872 regs_user
->regs
= NULL
;
5876 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5877 struct pt_regs
*regs
)
5879 regs_intr
->regs
= regs
;
5880 regs_intr
->abi
= perf_reg_abi(current
);
5885 * Get remaining task size from user stack pointer.
5887 * It'd be better to take stack vma map and limit this more
5888 * precisly, but there's no way to get it safely under interrupt,
5889 * so using TASK_SIZE as limit.
5891 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5893 unsigned long addr
= perf_user_stack_pointer(regs
);
5895 if (!addr
|| addr
>= TASK_SIZE
)
5898 return TASK_SIZE
- addr
;
5902 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5903 struct pt_regs
*regs
)
5907 /* No regs, no stack pointer, no dump. */
5912 * Check if we fit in with the requested stack size into the:
5914 * If we don't, we limit the size to the TASK_SIZE.
5916 * - remaining sample size
5917 * If we don't, we customize the stack size to
5918 * fit in to the remaining sample size.
5921 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5922 stack_size
= min(stack_size
, (u16
) task_size
);
5924 /* Current header size plus static size and dynamic size. */
5925 header_size
+= 2 * sizeof(u64
);
5927 /* Do we fit in with the current stack dump size? */
5928 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5930 * If we overflow the maximum size for the sample,
5931 * we customize the stack dump size to fit in.
5933 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5934 stack_size
= round_up(stack_size
, sizeof(u64
));
5941 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5942 struct pt_regs
*regs
)
5944 /* Case of a kernel thread, nothing to dump */
5947 perf_output_put(handle
, size
);
5957 * - the size requested by user or the best one we can fit
5958 * in to the sample max size
5960 * - user stack dump data
5962 * - the actual dumped size
5966 perf_output_put(handle
, dump_size
);
5969 sp
= perf_user_stack_pointer(regs
);
5972 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5974 dyn_size
= dump_size
- rem
;
5976 perf_output_skip(handle
, rem
);
5979 perf_output_put(handle
, dyn_size
);
5983 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5984 struct perf_sample_data
*data
,
5985 struct perf_event
*event
)
5987 u64 sample_type
= event
->attr
.sample_type
;
5989 data
->type
= sample_type
;
5990 header
->size
+= event
->id_header_size
;
5992 if (sample_type
& PERF_SAMPLE_TID
) {
5993 /* namespace issues */
5994 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5995 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5998 if (sample_type
& PERF_SAMPLE_TIME
)
5999 data
->time
= perf_event_clock(event
);
6001 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
6002 data
->id
= primary_event_id(event
);
6004 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6005 data
->stream_id
= event
->id
;
6007 if (sample_type
& PERF_SAMPLE_CPU
) {
6008 data
->cpu_entry
.cpu
= raw_smp_processor_id();
6009 data
->cpu_entry
.reserved
= 0;
6013 void perf_event_header__init_id(struct perf_event_header
*header
,
6014 struct perf_sample_data
*data
,
6015 struct perf_event
*event
)
6017 if (event
->attr
.sample_id_all
)
6018 __perf_event_header__init_id(header
, data
, event
);
6021 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
6022 struct perf_sample_data
*data
)
6024 u64 sample_type
= data
->type
;
6026 if (sample_type
& PERF_SAMPLE_TID
)
6027 perf_output_put(handle
, data
->tid_entry
);
6029 if (sample_type
& PERF_SAMPLE_TIME
)
6030 perf_output_put(handle
, data
->time
);
6032 if (sample_type
& PERF_SAMPLE_ID
)
6033 perf_output_put(handle
, data
->id
);
6035 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6036 perf_output_put(handle
, data
->stream_id
);
6038 if (sample_type
& PERF_SAMPLE_CPU
)
6039 perf_output_put(handle
, data
->cpu_entry
);
6041 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6042 perf_output_put(handle
, data
->id
);
6045 void perf_event__output_id_sample(struct perf_event
*event
,
6046 struct perf_output_handle
*handle
,
6047 struct perf_sample_data
*sample
)
6049 if (event
->attr
.sample_id_all
)
6050 __perf_event__output_id_sample(handle
, sample
);
6053 static void perf_output_read_one(struct perf_output_handle
*handle
,
6054 struct perf_event
*event
,
6055 u64 enabled
, u64 running
)
6057 u64 read_format
= event
->attr
.read_format
;
6061 values
[n
++] = perf_event_count(event
);
6062 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
6063 values
[n
++] = enabled
+
6064 atomic64_read(&event
->child_total_time_enabled
);
6066 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
6067 values
[n
++] = running
+
6068 atomic64_read(&event
->child_total_time_running
);
6070 if (read_format
& PERF_FORMAT_ID
)
6071 values
[n
++] = primary_event_id(event
);
6073 __output_copy(handle
, values
, n
* sizeof(u64
));
6076 static void perf_output_read_group(struct perf_output_handle
*handle
,
6077 struct perf_event
*event
,
6078 u64 enabled
, u64 running
)
6080 struct perf_event
*leader
= event
->group_leader
, *sub
;
6081 u64 read_format
= event
->attr
.read_format
;
6085 values
[n
++] = 1 + leader
->nr_siblings
;
6087 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
6088 values
[n
++] = enabled
;
6090 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
6091 values
[n
++] = running
;
6093 if ((leader
!= event
) &&
6094 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
6095 leader
->pmu
->read(leader
);
6097 values
[n
++] = perf_event_count(leader
);
6098 if (read_format
& PERF_FORMAT_ID
)
6099 values
[n
++] = primary_event_id(leader
);
6101 __output_copy(handle
, values
, n
* sizeof(u64
));
6103 for_each_sibling_event(sub
, leader
) {
6106 if ((sub
!= event
) &&
6107 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
6108 sub
->pmu
->read(sub
);
6110 values
[n
++] = perf_event_count(sub
);
6111 if (read_format
& PERF_FORMAT_ID
)
6112 values
[n
++] = primary_event_id(sub
);
6114 __output_copy(handle
, values
, n
* sizeof(u64
));
6118 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
6119 PERF_FORMAT_TOTAL_TIME_RUNNING)
6122 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
6124 * The problem is that its both hard and excessively expensive to iterate the
6125 * child list, not to mention that its impossible to IPI the children running
6126 * on another CPU, from interrupt/NMI context.
6128 static void perf_output_read(struct perf_output_handle
*handle
,
6129 struct perf_event
*event
)
6131 u64 enabled
= 0, running
= 0, now
;
6132 u64 read_format
= event
->attr
.read_format
;
6135 * compute total_time_enabled, total_time_running
6136 * based on snapshot values taken when the event
6137 * was last scheduled in.
6139 * we cannot simply called update_context_time()
6140 * because of locking issue as we are called in
6143 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
6144 calc_timer_values(event
, &now
, &enabled
, &running
);
6146 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
6147 perf_output_read_group(handle
, event
, enabled
, running
);
6149 perf_output_read_one(handle
, event
, enabled
, running
);
6152 void perf_output_sample(struct perf_output_handle
*handle
,
6153 struct perf_event_header
*header
,
6154 struct perf_sample_data
*data
,
6155 struct perf_event
*event
)
6157 u64 sample_type
= data
->type
;
6159 perf_output_put(handle
, *header
);
6161 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6162 perf_output_put(handle
, data
->id
);
6164 if (sample_type
& PERF_SAMPLE_IP
)
6165 perf_output_put(handle
, data
->ip
);
6167 if (sample_type
& PERF_SAMPLE_TID
)
6168 perf_output_put(handle
, data
->tid_entry
);
6170 if (sample_type
& PERF_SAMPLE_TIME
)
6171 perf_output_put(handle
, data
->time
);
6173 if (sample_type
& PERF_SAMPLE_ADDR
)
6174 perf_output_put(handle
, data
->addr
);
6176 if (sample_type
& PERF_SAMPLE_ID
)
6177 perf_output_put(handle
, data
->id
);
6179 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6180 perf_output_put(handle
, data
->stream_id
);
6182 if (sample_type
& PERF_SAMPLE_CPU
)
6183 perf_output_put(handle
, data
->cpu_entry
);
6185 if (sample_type
& PERF_SAMPLE_PERIOD
)
6186 perf_output_put(handle
, data
->period
);
6188 if (sample_type
& PERF_SAMPLE_READ
)
6189 perf_output_read(handle
, event
);
6191 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6194 size
+= data
->callchain
->nr
;
6195 size
*= sizeof(u64
);
6196 __output_copy(handle
, data
->callchain
, size
);
6199 if (sample_type
& PERF_SAMPLE_RAW
) {
6200 struct perf_raw_record
*raw
= data
->raw
;
6203 struct perf_raw_frag
*frag
= &raw
->frag
;
6205 perf_output_put(handle
, raw
->size
);
6208 __output_custom(handle
, frag
->copy
,
6209 frag
->data
, frag
->size
);
6211 __output_copy(handle
, frag
->data
,
6214 if (perf_raw_frag_last(frag
))
6219 __output_skip(handle
, NULL
, frag
->pad
);
6225 .size
= sizeof(u32
),
6228 perf_output_put(handle
, raw
);
6232 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6233 if (data
->br_stack
) {
6236 size
= data
->br_stack
->nr
6237 * sizeof(struct perf_branch_entry
);
6239 perf_output_put(handle
, data
->br_stack
->nr
);
6240 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
6243 * we always store at least the value of nr
6246 perf_output_put(handle
, nr
);
6250 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6251 u64 abi
= data
->regs_user
.abi
;
6254 * If there are no regs to dump, notice it through
6255 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6257 perf_output_put(handle
, abi
);
6260 u64 mask
= event
->attr
.sample_regs_user
;
6261 perf_output_sample_regs(handle
,
6262 data
->regs_user
.regs
,
6267 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6268 perf_output_sample_ustack(handle
,
6269 data
->stack_user_size
,
6270 data
->regs_user
.regs
);
6273 if (sample_type
& PERF_SAMPLE_WEIGHT
)
6274 perf_output_put(handle
, data
->weight
);
6276 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6277 perf_output_put(handle
, data
->data_src
.val
);
6279 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6280 perf_output_put(handle
, data
->txn
);
6282 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6283 u64 abi
= data
->regs_intr
.abi
;
6285 * If there are no regs to dump, notice it through
6286 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6288 perf_output_put(handle
, abi
);
6291 u64 mask
= event
->attr
.sample_regs_intr
;
6293 perf_output_sample_regs(handle
,
6294 data
->regs_intr
.regs
,
6299 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6300 perf_output_put(handle
, data
->phys_addr
);
6302 if (!event
->attr
.watermark
) {
6303 int wakeup_events
= event
->attr
.wakeup_events
;
6305 if (wakeup_events
) {
6306 struct ring_buffer
*rb
= handle
->rb
;
6307 int events
= local_inc_return(&rb
->events
);
6309 if (events
>= wakeup_events
) {
6310 local_sub(wakeup_events
, &rb
->events
);
6311 local_inc(&rb
->wakeup
);
6317 static u64
perf_virt_to_phys(u64 virt
)
6320 struct page
*p
= NULL
;
6325 if (virt
>= TASK_SIZE
) {
6326 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6327 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6328 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6329 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6332 * Walking the pages tables for user address.
6333 * Interrupts are disabled, so it prevents any tear down
6334 * of the page tables.
6335 * Try IRQ-safe __get_user_pages_fast first.
6336 * If failed, leave phys_addr as 0.
6338 if ((current
->mm
!= NULL
) &&
6339 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6340 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6349 static struct perf_callchain_entry __empty_callchain
= { .nr
= 0, };
6351 struct perf_callchain_entry
*
6352 perf_callchain(struct perf_event
*event
, struct pt_regs
*regs
)
6354 bool kernel
= !event
->attr
.exclude_callchain_kernel
;
6355 bool user
= !event
->attr
.exclude_callchain_user
;
6356 /* Disallow cross-task user callchains. */
6357 bool crosstask
= event
->ctx
->task
&& event
->ctx
->task
!= current
;
6358 const u32 max_stack
= event
->attr
.sample_max_stack
;
6359 struct perf_callchain_entry
*callchain
;
6361 if (!kernel
&& !user
)
6362 return &__empty_callchain
;
6364 callchain
= get_perf_callchain(regs
, 0, kernel
, user
,
6365 max_stack
, crosstask
, true);
6366 return callchain
?: &__empty_callchain
;
6369 void perf_prepare_sample(struct perf_event_header
*header
,
6370 struct perf_sample_data
*data
,
6371 struct perf_event
*event
,
6372 struct pt_regs
*regs
)
6374 u64 sample_type
= event
->attr
.sample_type
;
6376 header
->type
= PERF_RECORD_SAMPLE
;
6377 header
->size
= sizeof(*header
) + event
->header_size
;
6380 header
->misc
|= perf_misc_flags(regs
);
6382 __perf_event_header__init_id(header
, data
, event
);
6384 if (sample_type
& PERF_SAMPLE_IP
)
6385 data
->ip
= perf_instruction_pointer(regs
);
6387 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6390 if (!(sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
))
6391 data
->callchain
= perf_callchain(event
, regs
);
6393 size
+= data
->callchain
->nr
;
6395 header
->size
+= size
* sizeof(u64
);
6398 if (sample_type
& PERF_SAMPLE_RAW
) {
6399 struct perf_raw_record
*raw
= data
->raw
;
6403 struct perf_raw_frag
*frag
= &raw
->frag
;
6408 if (perf_raw_frag_last(frag
))
6413 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6414 raw
->size
= size
- sizeof(u32
);
6415 frag
->pad
= raw
->size
- sum
;
6420 header
->size
+= size
;
6423 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6424 int size
= sizeof(u64
); /* nr */
6425 if (data
->br_stack
) {
6426 size
+= data
->br_stack
->nr
6427 * sizeof(struct perf_branch_entry
);
6429 header
->size
+= size
;
6432 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6433 perf_sample_regs_user(&data
->regs_user
, regs
,
6434 &data
->regs_user_copy
);
6436 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6437 /* regs dump ABI info */
6438 int size
= sizeof(u64
);
6440 if (data
->regs_user
.regs
) {
6441 u64 mask
= event
->attr
.sample_regs_user
;
6442 size
+= hweight64(mask
) * sizeof(u64
);
6445 header
->size
+= size
;
6448 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6450 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6451 * processed as the last one or have additional check added
6452 * in case new sample type is added, because we could eat
6453 * up the rest of the sample size.
6455 u16 stack_size
= event
->attr
.sample_stack_user
;
6456 u16 size
= sizeof(u64
);
6458 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6459 data
->regs_user
.regs
);
6462 * If there is something to dump, add space for the dump
6463 * itself and for the field that tells the dynamic size,
6464 * which is how many have been actually dumped.
6467 size
+= sizeof(u64
) + stack_size
;
6469 data
->stack_user_size
= stack_size
;
6470 header
->size
+= size
;
6473 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6474 /* regs dump ABI info */
6475 int size
= sizeof(u64
);
6477 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6479 if (data
->regs_intr
.regs
) {
6480 u64 mask
= event
->attr
.sample_regs_intr
;
6482 size
+= hweight64(mask
) * sizeof(u64
);
6485 header
->size
+= size
;
6488 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6489 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6492 static __always_inline
void
6493 __perf_event_output(struct perf_event
*event
,
6494 struct perf_sample_data
*data
,
6495 struct pt_regs
*regs
,
6496 int (*output_begin
)(struct perf_output_handle
*,
6497 struct perf_event
*,
6500 struct perf_output_handle handle
;
6501 struct perf_event_header header
;
6503 /* protect the callchain buffers */
6506 perf_prepare_sample(&header
, data
, event
, regs
);
6508 if (output_begin(&handle
, event
, header
.size
))
6511 perf_output_sample(&handle
, &header
, data
, event
);
6513 perf_output_end(&handle
);
6520 perf_event_output_forward(struct perf_event
*event
,
6521 struct perf_sample_data
*data
,
6522 struct pt_regs
*regs
)
6524 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6528 perf_event_output_backward(struct perf_event
*event
,
6529 struct perf_sample_data
*data
,
6530 struct pt_regs
*regs
)
6532 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6536 perf_event_output(struct perf_event
*event
,
6537 struct perf_sample_data
*data
,
6538 struct pt_regs
*regs
)
6540 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6547 struct perf_read_event
{
6548 struct perf_event_header header
;
6555 perf_event_read_event(struct perf_event
*event
,
6556 struct task_struct
*task
)
6558 struct perf_output_handle handle
;
6559 struct perf_sample_data sample
;
6560 struct perf_read_event read_event
= {
6562 .type
= PERF_RECORD_READ
,
6564 .size
= sizeof(read_event
) + event
->read_size
,
6566 .pid
= perf_event_pid(event
, task
),
6567 .tid
= perf_event_tid(event
, task
),
6571 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6572 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6576 perf_output_put(&handle
, read_event
);
6577 perf_output_read(&handle
, event
);
6578 perf_event__output_id_sample(event
, &handle
, &sample
);
6580 perf_output_end(&handle
);
6583 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6586 perf_iterate_ctx(struct perf_event_context
*ctx
,
6587 perf_iterate_f output
,
6588 void *data
, bool all
)
6590 struct perf_event
*event
;
6592 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6594 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6596 if (!event_filter_match(event
))
6600 output(event
, data
);
6604 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6606 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6607 struct perf_event
*event
;
6609 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6611 * Skip events that are not fully formed yet; ensure that
6612 * if we observe event->ctx, both event and ctx will be
6613 * complete enough. See perf_install_in_context().
6615 if (!smp_load_acquire(&event
->ctx
))
6618 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6620 if (!event_filter_match(event
))
6622 output(event
, data
);
6627 * Iterate all events that need to receive side-band events.
6629 * For new callers; ensure that account_pmu_sb_event() includes
6630 * your event, otherwise it might not get delivered.
6633 perf_iterate_sb(perf_iterate_f output
, void *data
,
6634 struct perf_event_context
*task_ctx
)
6636 struct perf_event_context
*ctx
;
6643 * If we have task_ctx != NULL we only notify the task context itself.
6644 * The task_ctx is set only for EXIT events before releasing task
6648 perf_iterate_ctx(task_ctx
, output
, data
, false);
6652 perf_iterate_sb_cpu(output
, data
);
6654 for_each_task_context_nr(ctxn
) {
6655 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6657 perf_iterate_ctx(ctx
, output
, data
, false);
6665 * Clear all file-based filters at exec, they'll have to be
6666 * re-instated when/if these objects are mmapped again.
6668 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6670 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6671 struct perf_addr_filter
*filter
;
6672 unsigned int restart
= 0, count
= 0;
6673 unsigned long flags
;
6675 if (!has_addr_filter(event
))
6678 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6679 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6680 if (filter
->path
.dentry
) {
6681 event
->addr_filters_offs
[count
] = 0;
6689 event
->addr_filters_gen
++;
6690 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6693 perf_event_stop(event
, 1);
6696 void perf_event_exec(void)
6698 struct perf_event_context
*ctx
;
6702 for_each_task_context_nr(ctxn
) {
6703 ctx
= current
->perf_event_ctxp
[ctxn
];
6707 perf_event_enable_on_exec(ctxn
);
6709 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6715 struct remote_output
{
6716 struct ring_buffer
*rb
;
6720 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6722 struct perf_event
*parent
= event
->parent
;
6723 struct remote_output
*ro
= data
;
6724 struct ring_buffer
*rb
= ro
->rb
;
6725 struct stop_event_data sd
= {
6729 if (!has_aux(event
))
6736 * In case of inheritance, it will be the parent that links to the
6737 * ring-buffer, but it will be the child that's actually using it.
6739 * We are using event::rb to determine if the event should be stopped,
6740 * however this may race with ring_buffer_attach() (through set_output),
6741 * which will make us skip the event that actually needs to be stopped.
6742 * So ring_buffer_attach() has to stop an aux event before re-assigning
6745 if (rcu_dereference(parent
->rb
) == rb
)
6746 ro
->err
= __perf_event_stop(&sd
);
6749 static int __perf_pmu_output_stop(void *info
)
6751 struct perf_event
*event
= info
;
6752 struct pmu
*pmu
= event
->pmu
;
6753 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6754 struct remote_output ro
= {
6759 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6760 if (cpuctx
->task_ctx
)
6761 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6768 static void perf_pmu_output_stop(struct perf_event
*event
)
6770 struct perf_event
*iter
;
6775 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6777 * For per-CPU events, we need to make sure that neither they
6778 * nor their children are running; for cpu==-1 events it's
6779 * sufficient to stop the event itself if it's active, since
6780 * it can't have children.
6784 cpu
= READ_ONCE(iter
->oncpu
);
6789 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6790 if (err
== -EAGAIN
) {
6799 * task tracking -- fork/exit
6801 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6804 struct perf_task_event
{
6805 struct task_struct
*task
;
6806 struct perf_event_context
*task_ctx
;
6809 struct perf_event_header header
;
6819 static int perf_event_task_match(struct perf_event
*event
)
6821 return event
->attr
.comm
|| event
->attr
.mmap
||
6822 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6826 static void perf_event_task_output(struct perf_event
*event
,
6829 struct perf_task_event
*task_event
= data
;
6830 struct perf_output_handle handle
;
6831 struct perf_sample_data sample
;
6832 struct task_struct
*task
= task_event
->task
;
6833 int ret
, size
= task_event
->event_id
.header
.size
;
6835 if (!perf_event_task_match(event
))
6838 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6840 ret
= perf_output_begin(&handle
, event
,
6841 task_event
->event_id
.header
.size
);
6845 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6846 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6848 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6849 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6851 task_event
->event_id
.time
= perf_event_clock(event
);
6853 perf_output_put(&handle
, task_event
->event_id
);
6855 perf_event__output_id_sample(event
, &handle
, &sample
);
6857 perf_output_end(&handle
);
6859 task_event
->event_id
.header
.size
= size
;
6862 static void perf_event_task(struct task_struct
*task
,
6863 struct perf_event_context
*task_ctx
,
6866 struct perf_task_event task_event
;
6868 if (!atomic_read(&nr_comm_events
) &&
6869 !atomic_read(&nr_mmap_events
) &&
6870 !atomic_read(&nr_task_events
))
6873 task_event
= (struct perf_task_event
){
6875 .task_ctx
= task_ctx
,
6878 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6880 .size
= sizeof(task_event
.event_id
),
6890 perf_iterate_sb(perf_event_task_output
,
6895 void perf_event_fork(struct task_struct
*task
)
6897 perf_event_task(task
, NULL
, 1);
6898 perf_event_namespaces(task
);
6905 struct perf_comm_event
{
6906 struct task_struct
*task
;
6911 struct perf_event_header header
;
6918 static int perf_event_comm_match(struct perf_event
*event
)
6920 return event
->attr
.comm
;
6923 static void perf_event_comm_output(struct perf_event
*event
,
6926 struct perf_comm_event
*comm_event
= data
;
6927 struct perf_output_handle handle
;
6928 struct perf_sample_data sample
;
6929 int size
= comm_event
->event_id
.header
.size
;
6932 if (!perf_event_comm_match(event
))
6935 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6936 ret
= perf_output_begin(&handle
, event
,
6937 comm_event
->event_id
.header
.size
);
6942 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6943 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6945 perf_output_put(&handle
, comm_event
->event_id
);
6946 __output_copy(&handle
, comm_event
->comm
,
6947 comm_event
->comm_size
);
6949 perf_event__output_id_sample(event
, &handle
, &sample
);
6951 perf_output_end(&handle
);
6953 comm_event
->event_id
.header
.size
= size
;
6956 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6958 char comm
[TASK_COMM_LEN
];
6961 memset(comm
, 0, sizeof(comm
));
6962 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6963 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6965 comm_event
->comm
= comm
;
6966 comm_event
->comm_size
= size
;
6968 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6970 perf_iterate_sb(perf_event_comm_output
,
6975 void perf_event_comm(struct task_struct
*task
, bool exec
)
6977 struct perf_comm_event comm_event
;
6979 if (!atomic_read(&nr_comm_events
))
6982 comm_event
= (struct perf_comm_event
){
6988 .type
= PERF_RECORD_COMM
,
6989 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6997 perf_event_comm_event(&comm_event
);
7001 * namespaces tracking
7004 struct perf_namespaces_event
{
7005 struct task_struct
*task
;
7008 struct perf_event_header header
;
7013 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
7017 static int perf_event_namespaces_match(struct perf_event
*event
)
7019 return event
->attr
.namespaces
;
7022 static void perf_event_namespaces_output(struct perf_event
*event
,
7025 struct perf_namespaces_event
*namespaces_event
= data
;
7026 struct perf_output_handle handle
;
7027 struct perf_sample_data sample
;
7028 u16 header_size
= namespaces_event
->event_id
.header
.size
;
7031 if (!perf_event_namespaces_match(event
))
7034 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
7036 ret
= perf_output_begin(&handle
, event
,
7037 namespaces_event
->event_id
.header
.size
);
7041 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
7042 namespaces_event
->task
);
7043 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
7044 namespaces_event
->task
);
7046 perf_output_put(&handle
, namespaces_event
->event_id
);
7048 perf_event__output_id_sample(event
, &handle
, &sample
);
7050 perf_output_end(&handle
);
7052 namespaces_event
->event_id
.header
.size
= header_size
;
7055 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
7056 struct task_struct
*task
,
7057 const struct proc_ns_operations
*ns_ops
)
7059 struct path ns_path
;
7060 struct inode
*ns_inode
;
7063 error
= ns_get_path(&ns_path
, task
, ns_ops
);
7065 ns_inode
= ns_path
.dentry
->d_inode
;
7066 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
7067 ns_link_info
->ino
= ns_inode
->i_ino
;
7072 void perf_event_namespaces(struct task_struct
*task
)
7074 struct perf_namespaces_event namespaces_event
;
7075 struct perf_ns_link_info
*ns_link_info
;
7077 if (!atomic_read(&nr_namespaces_events
))
7080 namespaces_event
= (struct perf_namespaces_event
){
7084 .type
= PERF_RECORD_NAMESPACES
,
7086 .size
= sizeof(namespaces_event
.event_id
),
7090 .nr_namespaces
= NR_NAMESPACES
,
7091 /* .link_info[NR_NAMESPACES] */
7095 ns_link_info
= namespaces_event
.event_id
.link_info
;
7097 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
7098 task
, &mntns_operations
);
7100 #ifdef CONFIG_USER_NS
7101 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
7102 task
, &userns_operations
);
7104 #ifdef CONFIG_NET_NS
7105 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
7106 task
, &netns_operations
);
7108 #ifdef CONFIG_UTS_NS
7109 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
7110 task
, &utsns_operations
);
7112 #ifdef CONFIG_IPC_NS
7113 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
7114 task
, &ipcns_operations
);
7116 #ifdef CONFIG_PID_NS
7117 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
7118 task
, &pidns_operations
);
7120 #ifdef CONFIG_CGROUPS
7121 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
7122 task
, &cgroupns_operations
);
7125 perf_iterate_sb(perf_event_namespaces_output
,
7134 struct perf_mmap_event
{
7135 struct vm_area_struct
*vma
;
7137 const char *file_name
;
7145 struct perf_event_header header
;
7155 static int perf_event_mmap_match(struct perf_event
*event
,
7158 struct perf_mmap_event
*mmap_event
= data
;
7159 struct vm_area_struct
*vma
= mmap_event
->vma
;
7160 int executable
= vma
->vm_flags
& VM_EXEC
;
7162 return (!executable
&& event
->attr
.mmap_data
) ||
7163 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
7166 static void perf_event_mmap_output(struct perf_event
*event
,
7169 struct perf_mmap_event
*mmap_event
= data
;
7170 struct perf_output_handle handle
;
7171 struct perf_sample_data sample
;
7172 int size
= mmap_event
->event_id
.header
.size
;
7175 if (!perf_event_mmap_match(event
, data
))
7178 if (event
->attr
.mmap2
) {
7179 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
7180 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
7181 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
7182 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
7183 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
7184 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
7185 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
7188 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
7189 ret
= perf_output_begin(&handle
, event
,
7190 mmap_event
->event_id
.header
.size
);
7194 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
7195 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
7197 perf_output_put(&handle
, mmap_event
->event_id
);
7199 if (event
->attr
.mmap2
) {
7200 perf_output_put(&handle
, mmap_event
->maj
);
7201 perf_output_put(&handle
, mmap_event
->min
);
7202 perf_output_put(&handle
, mmap_event
->ino
);
7203 perf_output_put(&handle
, mmap_event
->ino_generation
);
7204 perf_output_put(&handle
, mmap_event
->prot
);
7205 perf_output_put(&handle
, mmap_event
->flags
);
7208 __output_copy(&handle
, mmap_event
->file_name
,
7209 mmap_event
->file_size
);
7211 perf_event__output_id_sample(event
, &handle
, &sample
);
7213 perf_output_end(&handle
);
7215 mmap_event
->event_id
.header
.size
= size
;
7218 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
7220 struct vm_area_struct
*vma
= mmap_event
->vma
;
7221 struct file
*file
= vma
->vm_file
;
7222 int maj
= 0, min
= 0;
7223 u64 ino
= 0, gen
= 0;
7224 u32 prot
= 0, flags
= 0;
7230 if (vma
->vm_flags
& VM_READ
)
7232 if (vma
->vm_flags
& VM_WRITE
)
7234 if (vma
->vm_flags
& VM_EXEC
)
7237 if (vma
->vm_flags
& VM_MAYSHARE
)
7240 flags
= MAP_PRIVATE
;
7242 if (vma
->vm_flags
& VM_DENYWRITE
)
7243 flags
|= MAP_DENYWRITE
;
7244 if (vma
->vm_flags
& VM_MAYEXEC
)
7245 flags
|= MAP_EXECUTABLE
;
7246 if (vma
->vm_flags
& VM_LOCKED
)
7247 flags
|= MAP_LOCKED
;
7248 if (vma
->vm_flags
& VM_HUGETLB
)
7249 flags
|= MAP_HUGETLB
;
7252 struct inode
*inode
;
7255 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
7261 * d_path() works from the end of the rb backwards, so we
7262 * need to add enough zero bytes after the string to handle
7263 * the 64bit alignment we do later.
7265 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
7270 inode
= file_inode(vma
->vm_file
);
7271 dev
= inode
->i_sb
->s_dev
;
7273 gen
= inode
->i_generation
;
7279 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
7280 name
= (char *) vma
->vm_ops
->name(vma
);
7285 name
= (char *)arch_vma_name(vma
);
7289 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
7290 vma
->vm_end
>= vma
->vm_mm
->brk
) {
7294 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
7295 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
7305 strlcpy(tmp
, name
, sizeof(tmp
));
7309 * Since our buffer works in 8 byte units we need to align our string
7310 * size to a multiple of 8. However, we must guarantee the tail end is
7311 * zero'd out to avoid leaking random bits to userspace.
7313 size
= strlen(name
)+1;
7314 while (!IS_ALIGNED(size
, sizeof(u64
)))
7315 name
[size
++] = '\0';
7317 mmap_event
->file_name
= name
;
7318 mmap_event
->file_size
= size
;
7319 mmap_event
->maj
= maj
;
7320 mmap_event
->min
= min
;
7321 mmap_event
->ino
= ino
;
7322 mmap_event
->ino_generation
= gen
;
7323 mmap_event
->prot
= prot
;
7324 mmap_event
->flags
= flags
;
7326 if (!(vma
->vm_flags
& VM_EXEC
))
7327 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
7329 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7331 perf_iterate_sb(perf_event_mmap_output
,
7339 * Check whether inode and address range match filter criteria.
7341 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7342 struct file
*file
, unsigned long offset
,
7345 /* d_inode(NULL) won't be equal to any mapped user-space file */
7346 if (!filter
->path
.dentry
)
7349 if (d_inode(filter
->path
.dentry
) != file_inode(file
))
7352 if (filter
->offset
> offset
+ size
)
7355 if (filter
->offset
+ filter
->size
< offset
)
7361 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7363 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7364 struct vm_area_struct
*vma
= data
;
7365 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
7366 struct file
*file
= vma
->vm_file
;
7367 struct perf_addr_filter
*filter
;
7368 unsigned int restart
= 0, count
= 0;
7370 if (!has_addr_filter(event
))
7376 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7377 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7378 if (perf_addr_filter_match(filter
, file
, off
,
7379 vma
->vm_end
- vma
->vm_start
)) {
7380 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7388 event
->addr_filters_gen
++;
7389 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7392 perf_event_stop(event
, 1);
7396 * Adjust all task's events' filters to the new vma
7398 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7400 struct perf_event_context
*ctx
;
7404 * Data tracing isn't supported yet and as such there is no need
7405 * to keep track of anything that isn't related to executable code:
7407 if (!(vma
->vm_flags
& VM_EXEC
))
7411 for_each_task_context_nr(ctxn
) {
7412 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7416 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7421 void perf_event_mmap(struct vm_area_struct
*vma
)
7423 struct perf_mmap_event mmap_event
;
7425 if (!atomic_read(&nr_mmap_events
))
7428 mmap_event
= (struct perf_mmap_event
){
7434 .type
= PERF_RECORD_MMAP
,
7435 .misc
= PERF_RECORD_MISC_USER
,
7440 .start
= vma
->vm_start
,
7441 .len
= vma
->vm_end
- vma
->vm_start
,
7442 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7444 /* .maj (attr_mmap2 only) */
7445 /* .min (attr_mmap2 only) */
7446 /* .ino (attr_mmap2 only) */
7447 /* .ino_generation (attr_mmap2 only) */
7448 /* .prot (attr_mmap2 only) */
7449 /* .flags (attr_mmap2 only) */
7452 perf_addr_filters_adjust(vma
);
7453 perf_event_mmap_event(&mmap_event
);
7456 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7457 unsigned long size
, u64 flags
)
7459 struct perf_output_handle handle
;
7460 struct perf_sample_data sample
;
7461 struct perf_aux_event
{
7462 struct perf_event_header header
;
7468 .type
= PERF_RECORD_AUX
,
7470 .size
= sizeof(rec
),
7478 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7479 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7484 perf_output_put(&handle
, rec
);
7485 perf_event__output_id_sample(event
, &handle
, &sample
);
7487 perf_output_end(&handle
);
7491 * Lost/dropped samples logging
7493 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7495 struct perf_output_handle handle
;
7496 struct perf_sample_data sample
;
7500 struct perf_event_header header
;
7502 } lost_samples_event
= {
7504 .type
= PERF_RECORD_LOST_SAMPLES
,
7506 .size
= sizeof(lost_samples_event
),
7511 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7513 ret
= perf_output_begin(&handle
, event
,
7514 lost_samples_event
.header
.size
);
7518 perf_output_put(&handle
, lost_samples_event
);
7519 perf_event__output_id_sample(event
, &handle
, &sample
);
7520 perf_output_end(&handle
);
7524 * context_switch tracking
7527 struct perf_switch_event
{
7528 struct task_struct
*task
;
7529 struct task_struct
*next_prev
;
7532 struct perf_event_header header
;
7538 static int perf_event_switch_match(struct perf_event
*event
)
7540 return event
->attr
.context_switch
;
7543 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7545 struct perf_switch_event
*se
= data
;
7546 struct perf_output_handle handle
;
7547 struct perf_sample_data sample
;
7550 if (!perf_event_switch_match(event
))
7553 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7554 if (event
->ctx
->task
) {
7555 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7556 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7558 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7559 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7560 se
->event_id
.next_prev_pid
=
7561 perf_event_pid(event
, se
->next_prev
);
7562 se
->event_id
.next_prev_tid
=
7563 perf_event_tid(event
, se
->next_prev
);
7566 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7568 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7572 if (event
->ctx
->task
)
7573 perf_output_put(&handle
, se
->event_id
.header
);
7575 perf_output_put(&handle
, se
->event_id
);
7577 perf_event__output_id_sample(event
, &handle
, &sample
);
7579 perf_output_end(&handle
);
7582 static void perf_event_switch(struct task_struct
*task
,
7583 struct task_struct
*next_prev
, bool sched_in
)
7585 struct perf_switch_event switch_event
;
7587 /* N.B. caller checks nr_switch_events != 0 */
7589 switch_event
= (struct perf_switch_event
){
7591 .next_prev
= next_prev
,
7595 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7598 /* .next_prev_pid */
7599 /* .next_prev_tid */
7603 if (!sched_in
&& task
->state
== TASK_RUNNING
)
7604 switch_event
.event_id
.header
.misc
|=
7605 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT
;
7607 perf_iterate_sb(perf_event_switch_output
,
7613 * IRQ throttle logging
7616 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7618 struct perf_output_handle handle
;
7619 struct perf_sample_data sample
;
7623 struct perf_event_header header
;
7627 } throttle_event
= {
7629 .type
= PERF_RECORD_THROTTLE
,
7631 .size
= sizeof(throttle_event
),
7633 .time
= perf_event_clock(event
),
7634 .id
= primary_event_id(event
),
7635 .stream_id
= event
->id
,
7639 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7641 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7643 ret
= perf_output_begin(&handle
, event
,
7644 throttle_event
.header
.size
);
7648 perf_output_put(&handle
, throttle_event
);
7649 perf_event__output_id_sample(event
, &handle
, &sample
);
7650 perf_output_end(&handle
);
7653 void perf_event_itrace_started(struct perf_event
*event
)
7655 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7658 static void perf_log_itrace_start(struct perf_event
*event
)
7660 struct perf_output_handle handle
;
7661 struct perf_sample_data sample
;
7662 struct perf_aux_event
{
7663 struct perf_event_header header
;
7670 event
= event
->parent
;
7672 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7673 event
->attach_state
& PERF_ATTACH_ITRACE
)
7676 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7677 rec
.header
.misc
= 0;
7678 rec
.header
.size
= sizeof(rec
);
7679 rec
.pid
= perf_event_pid(event
, current
);
7680 rec
.tid
= perf_event_tid(event
, current
);
7682 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7683 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7688 perf_output_put(&handle
, rec
);
7689 perf_event__output_id_sample(event
, &handle
, &sample
);
7691 perf_output_end(&handle
);
7695 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7697 struct hw_perf_event
*hwc
= &event
->hw
;
7701 seq
= __this_cpu_read(perf_throttled_seq
);
7702 if (seq
!= hwc
->interrupts_seq
) {
7703 hwc
->interrupts_seq
= seq
;
7704 hwc
->interrupts
= 1;
7707 if (unlikely(throttle
7708 && hwc
->interrupts
>= max_samples_per_tick
)) {
7709 __this_cpu_inc(perf_throttled_count
);
7710 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7711 hwc
->interrupts
= MAX_INTERRUPTS
;
7712 perf_log_throttle(event
, 0);
7717 if (event
->attr
.freq
) {
7718 u64 now
= perf_clock();
7719 s64 delta
= now
- hwc
->freq_time_stamp
;
7721 hwc
->freq_time_stamp
= now
;
7723 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7724 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7730 int perf_event_account_interrupt(struct perf_event
*event
)
7732 return __perf_event_account_interrupt(event
, 1);
7736 * Generic event overflow handling, sampling.
7739 static int __perf_event_overflow(struct perf_event
*event
,
7740 int throttle
, struct perf_sample_data
*data
,
7741 struct pt_regs
*regs
)
7743 int events
= atomic_read(&event
->event_limit
);
7747 * Non-sampling counters might still use the PMI to fold short
7748 * hardware counters, ignore those.
7750 if (unlikely(!is_sampling_event(event
)))
7753 ret
= __perf_event_account_interrupt(event
, throttle
);
7756 * XXX event_limit might not quite work as expected on inherited
7760 event
->pending_kill
= POLL_IN
;
7761 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7763 event
->pending_kill
= POLL_HUP
;
7765 perf_event_disable_inatomic(event
);
7768 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7770 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7771 event
->pending_wakeup
= 1;
7772 irq_work_queue(&event
->pending
);
7778 int perf_event_overflow(struct perf_event
*event
,
7779 struct perf_sample_data
*data
,
7780 struct pt_regs
*regs
)
7782 return __perf_event_overflow(event
, 1, data
, regs
);
7786 * Generic software event infrastructure
7789 struct swevent_htable
{
7790 struct swevent_hlist
*swevent_hlist
;
7791 struct mutex hlist_mutex
;
7794 /* Recursion avoidance in each contexts */
7795 int recursion
[PERF_NR_CONTEXTS
];
7798 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7801 * We directly increment event->count and keep a second value in
7802 * event->hw.period_left to count intervals. This period event
7803 * is kept in the range [-sample_period, 0] so that we can use the
7807 u64
perf_swevent_set_period(struct perf_event
*event
)
7809 struct hw_perf_event
*hwc
= &event
->hw
;
7810 u64 period
= hwc
->last_period
;
7814 hwc
->last_period
= hwc
->sample_period
;
7817 old
= val
= local64_read(&hwc
->period_left
);
7821 nr
= div64_u64(period
+ val
, period
);
7822 offset
= nr
* period
;
7824 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7830 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7831 struct perf_sample_data
*data
,
7832 struct pt_regs
*regs
)
7834 struct hw_perf_event
*hwc
= &event
->hw
;
7838 overflow
= perf_swevent_set_period(event
);
7840 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7843 for (; overflow
; overflow
--) {
7844 if (__perf_event_overflow(event
, throttle
,
7847 * We inhibit the overflow from happening when
7848 * hwc->interrupts == MAX_INTERRUPTS.
7856 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7857 struct perf_sample_data
*data
,
7858 struct pt_regs
*regs
)
7860 struct hw_perf_event
*hwc
= &event
->hw
;
7862 local64_add(nr
, &event
->count
);
7867 if (!is_sampling_event(event
))
7870 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7872 return perf_swevent_overflow(event
, 1, data
, regs
);
7874 data
->period
= event
->hw
.last_period
;
7876 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7877 return perf_swevent_overflow(event
, 1, data
, regs
);
7879 if (local64_add_negative(nr
, &hwc
->period_left
))
7882 perf_swevent_overflow(event
, 0, data
, regs
);
7885 static int perf_exclude_event(struct perf_event
*event
,
7886 struct pt_regs
*regs
)
7888 if (event
->hw
.state
& PERF_HES_STOPPED
)
7892 if (event
->attr
.exclude_user
&& user_mode(regs
))
7895 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7902 static int perf_swevent_match(struct perf_event
*event
,
7903 enum perf_type_id type
,
7905 struct perf_sample_data
*data
,
7906 struct pt_regs
*regs
)
7908 if (event
->attr
.type
!= type
)
7911 if (event
->attr
.config
!= event_id
)
7914 if (perf_exclude_event(event
, regs
))
7920 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7922 u64 val
= event_id
| (type
<< 32);
7924 return hash_64(val
, SWEVENT_HLIST_BITS
);
7927 static inline struct hlist_head
*
7928 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7930 u64 hash
= swevent_hash(type
, event_id
);
7932 return &hlist
->heads
[hash
];
7935 /* For the read side: events when they trigger */
7936 static inline struct hlist_head
*
7937 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7939 struct swevent_hlist
*hlist
;
7941 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7945 return __find_swevent_head(hlist
, type
, event_id
);
7948 /* For the event head insertion and removal in the hlist */
7949 static inline struct hlist_head
*
7950 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7952 struct swevent_hlist
*hlist
;
7953 u32 event_id
= event
->attr
.config
;
7954 u64 type
= event
->attr
.type
;
7957 * Event scheduling is always serialized against hlist allocation
7958 * and release. Which makes the protected version suitable here.
7959 * The context lock guarantees that.
7961 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7962 lockdep_is_held(&event
->ctx
->lock
));
7966 return __find_swevent_head(hlist
, type
, event_id
);
7969 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7971 struct perf_sample_data
*data
,
7972 struct pt_regs
*regs
)
7974 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7975 struct perf_event
*event
;
7976 struct hlist_head
*head
;
7979 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7983 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7984 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7985 perf_swevent_event(event
, nr
, data
, regs
);
7991 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7993 int perf_swevent_get_recursion_context(void)
7995 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7997 return get_recursion_context(swhash
->recursion
);
7999 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
8001 void perf_swevent_put_recursion_context(int rctx
)
8003 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8005 put_recursion_context(swhash
->recursion
, rctx
);
8008 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8010 struct perf_sample_data data
;
8012 if (WARN_ON_ONCE(!regs
))
8015 perf_sample_data_init(&data
, addr
, 0);
8016 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
8019 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8023 preempt_disable_notrace();
8024 rctx
= perf_swevent_get_recursion_context();
8025 if (unlikely(rctx
< 0))
8028 ___perf_sw_event(event_id
, nr
, regs
, addr
);
8030 perf_swevent_put_recursion_context(rctx
);
8032 preempt_enable_notrace();
8035 static void perf_swevent_read(struct perf_event
*event
)
8039 static int perf_swevent_add(struct perf_event
*event
, int flags
)
8041 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8042 struct hw_perf_event
*hwc
= &event
->hw
;
8043 struct hlist_head
*head
;
8045 if (is_sampling_event(event
)) {
8046 hwc
->last_period
= hwc
->sample_period
;
8047 perf_swevent_set_period(event
);
8050 hwc
->state
= !(flags
& PERF_EF_START
);
8052 head
= find_swevent_head(swhash
, event
);
8053 if (WARN_ON_ONCE(!head
))
8056 hlist_add_head_rcu(&event
->hlist_entry
, head
);
8057 perf_event_update_userpage(event
);
8062 static void perf_swevent_del(struct perf_event
*event
, int flags
)
8064 hlist_del_rcu(&event
->hlist_entry
);
8067 static void perf_swevent_start(struct perf_event
*event
, int flags
)
8069 event
->hw
.state
= 0;
8072 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
8074 event
->hw
.state
= PERF_HES_STOPPED
;
8077 /* Deref the hlist from the update side */
8078 static inline struct swevent_hlist
*
8079 swevent_hlist_deref(struct swevent_htable
*swhash
)
8081 return rcu_dereference_protected(swhash
->swevent_hlist
,
8082 lockdep_is_held(&swhash
->hlist_mutex
));
8085 static void swevent_hlist_release(struct swevent_htable
*swhash
)
8087 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
8092 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
8093 kfree_rcu(hlist
, rcu_head
);
8096 static void swevent_hlist_put_cpu(int cpu
)
8098 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8100 mutex_lock(&swhash
->hlist_mutex
);
8102 if (!--swhash
->hlist_refcount
)
8103 swevent_hlist_release(swhash
);
8105 mutex_unlock(&swhash
->hlist_mutex
);
8108 static void swevent_hlist_put(void)
8112 for_each_possible_cpu(cpu
)
8113 swevent_hlist_put_cpu(cpu
);
8116 static int swevent_hlist_get_cpu(int cpu
)
8118 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8121 mutex_lock(&swhash
->hlist_mutex
);
8122 if (!swevent_hlist_deref(swhash
) &&
8123 cpumask_test_cpu(cpu
, perf_online_mask
)) {
8124 struct swevent_hlist
*hlist
;
8126 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
8131 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
8133 swhash
->hlist_refcount
++;
8135 mutex_unlock(&swhash
->hlist_mutex
);
8140 static int swevent_hlist_get(void)
8142 int err
, cpu
, failed_cpu
;
8144 mutex_lock(&pmus_lock
);
8145 for_each_possible_cpu(cpu
) {
8146 err
= swevent_hlist_get_cpu(cpu
);
8152 mutex_unlock(&pmus_lock
);
8155 for_each_possible_cpu(cpu
) {
8156 if (cpu
== failed_cpu
)
8158 swevent_hlist_put_cpu(cpu
);
8160 mutex_unlock(&pmus_lock
);
8164 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
8166 static void sw_perf_event_destroy(struct perf_event
*event
)
8168 u64 event_id
= event
->attr
.config
;
8170 WARN_ON(event
->parent
);
8172 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
8173 swevent_hlist_put();
8176 static int perf_swevent_init(struct perf_event
*event
)
8178 u64 event_id
= event
->attr
.config
;
8180 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8184 * no branch sampling for software events
8186 if (has_branch_stack(event
))
8190 case PERF_COUNT_SW_CPU_CLOCK
:
8191 case PERF_COUNT_SW_TASK_CLOCK
:
8198 if (event_id
>= PERF_COUNT_SW_MAX
)
8201 if (!event
->parent
) {
8204 err
= swevent_hlist_get();
8208 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
8209 event
->destroy
= sw_perf_event_destroy
;
8215 static struct pmu perf_swevent
= {
8216 .task_ctx_nr
= perf_sw_context
,
8218 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8220 .event_init
= perf_swevent_init
,
8221 .add
= perf_swevent_add
,
8222 .del
= perf_swevent_del
,
8223 .start
= perf_swevent_start
,
8224 .stop
= perf_swevent_stop
,
8225 .read
= perf_swevent_read
,
8228 #ifdef CONFIG_EVENT_TRACING
8230 static int perf_tp_filter_match(struct perf_event
*event
,
8231 struct perf_sample_data
*data
)
8233 void *record
= data
->raw
->frag
.data
;
8235 /* only top level events have filters set */
8237 event
= event
->parent
;
8239 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
8244 static int perf_tp_event_match(struct perf_event
*event
,
8245 struct perf_sample_data
*data
,
8246 struct pt_regs
*regs
)
8248 if (event
->hw
.state
& PERF_HES_STOPPED
)
8251 * All tracepoints are from kernel-space.
8253 if (event
->attr
.exclude_kernel
)
8256 if (!perf_tp_filter_match(event
, data
))
8262 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
8263 struct trace_event_call
*call
, u64 count
,
8264 struct pt_regs
*regs
, struct hlist_head
*head
,
8265 struct task_struct
*task
)
8267 if (bpf_prog_array_valid(call
)) {
8268 *(struct pt_regs
**)raw_data
= regs
;
8269 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
8270 perf_swevent_put_recursion_context(rctx
);
8274 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
8277 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
8279 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
8280 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
8281 struct task_struct
*task
)
8283 struct perf_sample_data data
;
8284 struct perf_event
*event
;
8286 struct perf_raw_record raw
= {
8293 perf_sample_data_init(&data
, 0, 0);
8296 perf_trace_buf_update(record
, event_type
);
8298 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8299 if (perf_tp_event_match(event
, &data
, regs
))
8300 perf_swevent_event(event
, count
, &data
, regs
);
8304 * If we got specified a target task, also iterate its context and
8305 * deliver this event there too.
8307 if (task
&& task
!= current
) {
8308 struct perf_event_context
*ctx
;
8309 struct trace_entry
*entry
= record
;
8312 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
8316 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
8317 if (event
->cpu
!= smp_processor_id())
8319 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8321 if (event
->attr
.config
!= entry
->type
)
8323 if (perf_tp_event_match(event
, &data
, regs
))
8324 perf_swevent_event(event
, count
, &data
, regs
);
8330 perf_swevent_put_recursion_context(rctx
);
8332 EXPORT_SYMBOL_GPL(perf_tp_event
);
8334 static void tp_perf_event_destroy(struct perf_event
*event
)
8336 perf_trace_destroy(event
);
8339 static int perf_tp_event_init(struct perf_event
*event
)
8343 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8347 * no branch sampling for tracepoint events
8349 if (has_branch_stack(event
))
8352 err
= perf_trace_init(event
);
8356 event
->destroy
= tp_perf_event_destroy
;
8361 static struct pmu perf_tracepoint
= {
8362 .task_ctx_nr
= perf_sw_context
,
8364 .event_init
= perf_tp_event_init
,
8365 .add
= perf_trace_add
,
8366 .del
= perf_trace_del
,
8367 .start
= perf_swevent_start
,
8368 .stop
= perf_swevent_stop
,
8369 .read
= perf_swevent_read
,
8372 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
8374 * Flags in config, used by dynamic PMU kprobe and uprobe
8375 * The flags should match following PMU_FORMAT_ATTR().
8377 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
8378 * if not set, create kprobe/uprobe
8380 * The following values specify a reference counter (or semaphore in the
8381 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
8382 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
8384 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
8385 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
8387 enum perf_probe_config
{
8388 PERF_PROBE_CONFIG_IS_RETPROBE
= 1U << 0, /* [k,u]retprobe */
8389 PERF_UPROBE_REF_CTR_OFFSET_BITS
= 32,
8390 PERF_UPROBE_REF_CTR_OFFSET_SHIFT
= 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS
,
8393 PMU_FORMAT_ATTR(retprobe
, "config:0");
8396 #ifdef CONFIG_KPROBE_EVENTS
8397 static struct attribute
*kprobe_attrs
[] = {
8398 &format_attr_retprobe
.attr
,
8402 static struct attribute_group kprobe_format_group
= {
8404 .attrs
= kprobe_attrs
,
8407 static const struct attribute_group
*kprobe_attr_groups
[] = {
8408 &kprobe_format_group
,
8412 static int perf_kprobe_event_init(struct perf_event
*event
);
8413 static struct pmu perf_kprobe
= {
8414 .task_ctx_nr
= perf_sw_context
,
8415 .event_init
= perf_kprobe_event_init
,
8416 .add
= perf_trace_add
,
8417 .del
= perf_trace_del
,
8418 .start
= perf_swevent_start
,
8419 .stop
= perf_swevent_stop
,
8420 .read
= perf_swevent_read
,
8421 .attr_groups
= kprobe_attr_groups
,
8424 static int perf_kprobe_event_init(struct perf_event
*event
)
8429 if (event
->attr
.type
!= perf_kprobe
.type
)
8432 if (!capable(CAP_SYS_ADMIN
))
8436 * no branch sampling for probe events
8438 if (has_branch_stack(event
))
8441 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
8442 err
= perf_kprobe_init(event
, is_retprobe
);
8446 event
->destroy
= perf_kprobe_destroy
;
8450 #endif /* CONFIG_KPROBE_EVENTS */
8452 #ifdef CONFIG_UPROBE_EVENTS
8453 PMU_FORMAT_ATTR(ref_ctr_offset
, "config:32-63");
8455 static struct attribute
*uprobe_attrs
[] = {
8456 &format_attr_retprobe
.attr
,
8457 &format_attr_ref_ctr_offset
.attr
,
8461 static struct attribute_group uprobe_format_group
= {
8463 .attrs
= uprobe_attrs
,
8466 static const struct attribute_group
*uprobe_attr_groups
[] = {
8467 &uprobe_format_group
,
8471 static int perf_uprobe_event_init(struct perf_event
*event
);
8472 static struct pmu perf_uprobe
= {
8473 .task_ctx_nr
= perf_sw_context
,
8474 .event_init
= perf_uprobe_event_init
,
8475 .add
= perf_trace_add
,
8476 .del
= perf_trace_del
,
8477 .start
= perf_swevent_start
,
8478 .stop
= perf_swevent_stop
,
8479 .read
= perf_swevent_read
,
8480 .attr_groups
= uprobe_attr_groups
,
8483 static int perf_uprobe_event_init(struct perf_event
*event
)
8486 unsigned long ref_ctr_offset
;
8489 if (event
->attr
.type
!= perf_uprobe
.type
)
8492 if (!capable(CAP_SYS_ADMIN
))
8496 * no branch sampling for probe events
8498 if (has_branch_stack(event
))
8501 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
8502 ref_ctr_offset
= event
->attr
.config
>> PERF_UPROBE_REF_CTR_OFFSET_SHIFT
;
8503 err
= perf_uprobe_init(event
, ref_ctr_offset
, is_retprobe
);
8507 event
->destroy
= perf_uprobe_destroy
;
8511 #endif /* CONFIG_UPROBE_EVENTS */
8513 static inline void perf_tp_register(void)
8515 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8516 #ifdef CONFIG_KPROBE_EVENTS
8517 perf_pmu_register(&perf_kprobe
, "kprobe", -1);
8519 #ifdef CONFIG_UPROBE_EVENTS
8520 perf_pmu_register(&perf_uprobe
, "uprobe", -1);
8524 static void perf_event_free_filter(struct perf_event
*event
)
8526 ftrace_profile_free_filter(event
);
8529 #ifdef CONFIG_BPF_SYSCALL
8530 static void bpf_overflow_handler(struct perf_event
*event
,
8531 struct perf_sample_data
*data
,
8532 struct pt_regs
*regs
)
8534 struct bpf_perf_event_data_kern ctx
= {
8540 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
8542 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8545 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8548 __this_cpu_dec(bpf_prog_active
);
8553 event
->orig_overflow_handler(event
, data
, regs
);
8556 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8558 struct bpf_prog
*prog
;
8560 if (event
->overflow_handler_context
)
8561 /* hw breakpoint or kernel counter */
8567 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8569 return PTR_ERR(prog
);
8572 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8573 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8577 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8579 struct bpf_prog
*prog
= event
->prog
;
8584 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8589 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8593 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8599 * returns true if the event is a tracepoint, or a kprobe/upprobe created
8600 * with perf_event_open()
8602 static inline bool perf_event_is_tracing(struct perf_event
*event
)
8604 if (event
->pmu
== &perf_tracepoint
)
8606 #ifdef CONFIG_KPROBE_EVENTS
8607 if (event
->pmu
== &perf_kprobe
)
8610 #ifdef CONFIG_UPROBE_EVENTS
8611 if (event
->pmu
== &perf_uprobe
)
8617 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8619 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8620 struct bpf_prog
*prog
;
8623 if (!perf_event_is_tracing(event
))
8624 return perf_event_set_bpf_handler(event
, prog_fd
);
8626 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8627 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8628 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8629 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8630 /* bpf programs can only be attached to u/kprobe or tracepoint */
8633 prog
= bpf_prog_get(prog_fd
);
8635 return PTR_ERR(prog
);
8637 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8638 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8639 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8640 /* valid fd, but invalid bpf program type */
8645 /* Kprobe override only works for kprobes, not uprobes. */
8646 if (prog
->kprobe_override
&&
8647 !(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
)) {
8652 if (is_tracepoint
|| is_syscall_tp
) {
8653 int off
= trace_event_get_offsets(event
->tp_event
);
8655 if (prog
->aux
->max_ctx_offset
> off
) {
8661 ret
= perf_event_attach_bpf_prog(event
, prog
);
8667 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8669 if (!perf_event_is_tracing(event
)) {
8670 perf_event_free_bpf_handler(event
);
8673 perf_event_detach_bpf_prog(event
);
8678 static inline void perf_tp_register(void)
8682 static void perf_event_free_filter(struct perf_event
*event
)
8686 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8691 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8694 #endif /* CONFIG_EVENT_TRACING */
8696 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8697 void perf_bp_event(struct perf_event
*bp
, void *data
)
8699 struct perf_sample_data sample
;
8700 struct pt_regs
*regs
= data
;
8702 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8704 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8705 perf_swevent_event(bp
, 1, &sample
, regs
);
8710 * Allocate a new address filter
8712 static struct perf_addr_filter
*
8713 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8715 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8716 struct perf_addr_filter
*filter
;
8718 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8722 INIT_LIST_HEAD(&filter
->entry
);
8723 list_add_tail(&filter
->entry
, filters
);
8728 static void free_filters_list(struct list_head
*filters
)
8730 struct perf_addr_filter
*filter
, *iter
;
8732 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8733 path_put(&filter
->path
);
8734 list_del(&filter
->entry
);
8740 * Free existing address filters and optionally install new ones
8742 static void perf_addr_filters_splice(struct perf_event
*event
,
8743 struct list_head
*head
)
8745 unsigned long flags
;
8748 if (!has_addr_filter(event
))
8751 /* don't bother with children, they don't have their own filters */
8755 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8757 list_splice_init(&event
->addr_filters
.list
, &list
);
8759 list_splice(head
, &event
->addr_filters
.list
);
8761 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8763 free_filters_list(&list
);
8767 * Scan through mm's vmas and see if one of them matches the
8768 * @filter; if so, adjust filter's address range.
8769 * Called with mm::mmap_sem down for reading.
8771 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8772 struct mm_struct
*mm
)
8774 struct vm_area_struct
*vma
;
8776 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8777 struct file
*file
= vma
->vm_file
;
8778 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8779 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8784 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8787 return vma
->vm_start
;
8794 * Update event's address range filters based on the
8795 * task's existing mappings, if any.
8797 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8799 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8800 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8801 struct perf_addr_filter
*filter
;
8802 struct mm_struct
*mm
= NULL
;
8803 unsigned int count
= 0;
8804 unsigned long flags
;
8807 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8808 * will stop on the parent's child_mutex that our caller is also holding
8810 if (task
== TASK_TOMBSTONE
)
8813 if (!ifh
->nr_file_filters
)
8816 mm
= get_task_mm(event
->ctx
->task
);
8820 down_read(&mm
->mmap_sem
);
8822 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8823 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8824 event
->addr_filters_offs
[count
] = 0;
8827 * Adjust base offset if the filter is associated to a binary
8828 * that needs to be mapped:
8830 if (filter
->path
.dentry
)
8831 event
->addr_filters_offs
[count
] =
8832 perf_addr_filter_apply(filter
, mm
);
8837 event
->addr_filters_gen
++;
8838 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8840 up_read(&mm
->mmap_sem
);
8845 perf_event_stop(event
, 1);
8849 * Address range filtering: limiting the data to certain
8850 * instruction address ranges. Filters are ioctl()ed to us from
8851 * userspace as ascii strings.
8853 * Filter string format:
8856 * where ACTION is one of the
8857 * * "filter": limit the trace to this region
8858 * * "start": start tracing from this address
8859 * * "stop": stop tracing at this address/region;
8861 * * for kernel addresses: <start address>[/<size>]
8862 * * for object files: <start address>[/<size>]@</path/to/object/file>
8864 * if <size> is not specified or is zero, the range is treated as a single
8865 * address; not valid for ACTION=="filter".
8879 IF_STATE_ACTION
= 0,
8884 static const match_table_t if_tokens
= {
8885 { IF_ACT_FILTER
, "filter" },
8886 { IF_ACT_START
, "start" },
8887 { IF_ACT_STOP
, "stop" },
8888 { IF_SRC_FILE
, "%u/%u@%s" },
8889 { IF_SRC_KERNEL
, "%u/%u" },
8890 { IF_SRC_FILEADDR
, "%u@%s" },
8891 { IF_SRC_KERNELADDR
, "%u" },
8892 { IF_ACT_NONE
, NULL
},
8896 * Address filter string parser
8899 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8900 struct list_head
*filters
)
8902 struct perf_addr_filter
*filter
= NULL
;
8903 char *start
, *orig
, *filename
= NULL
;
8904 substring_t args
[MAX_OPT_ARGS
];
8905 int state
= IF_STATE_ACTION
, token
;
8906 unsigned int kernel
= 0;
8909 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8913 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8914 static const enum perf_addr_filter_action_t actions
[] = {
8915 [IF_ACT_FILTER
] = PERF_ADDR_FILTER_ACTION_FILTER
,
8916 [IF_ACT_START
] = PERF_ADDR_FILTER_ACTION_START
,
8917 [IF_ACT_STOP
] = PERF_ADDR_FILTER_ACTION_STOP
,
8924 /* filter definition begins */
8925 if (state
== IF_STATE_ACTION
) {
8926 filter
= perf_addr_filter_new(event
, filters
);
8931 token
= match_token(start
, if_tokens
, args
);
8936 if (state
!= IF_STATE_ACTION
)
8939 filter
->action
= actions
[token
];
8940 state
= IF_STATE_SOURCE
;
8943 case IF_SRC_KERNELADDR
:
8947 case IF_SRC_FILEADDR
:
8949 if (state
!= IF_STATE_SOURCE
)
8953 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8957 if (token
== IF_SRC_KERNEL
|| token
== IF_SRC_FILE
) {
8959 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8964 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8965 int fpos
= token
== IF_SRC_FILE
? 2 : 1;
8967 filename
= match_strdup(&args
[fpos
]);
8974 state
= IF_STATE_END
;
8982 * Filter definition is fully parsed, validate and install it.
8983 * Make sure that it doesn't contradict itself or the event's
8986 if (state
== IF_STATE_END
) {
8988 if (kernel
&& event
->attr
.exclude_kernel
)
8992 * ACTION "filter" must have a non-zero length region
8995 if (filter
->action
== PERF_ADDR_FILTER_ACTION_FILTER
&&
9004 * For now, we only support file-based filters
9005 * in per-task events; doing so for CPU-wide
9006 * events requires additional context switching
9007 * trickery, since same object code will be
9008 * mapped at different virtual addresses in
9009 * different processes.
9012 if (!event
->ctx
->task
)
9013 goto fail_free_name
;
9015 /* look up the path and grab its inode */
9016 ret
= kern_path(filename
, LOOKUP_FOLLOW
,
9019 goto fail_free_name
;
9025 if (!filter
->path
.dentry
||
9026 !S_ISREG(d_inode(filter
->path
.dentry
)
9030 event
->addr_filters
.nr_file_filters
++;
9033 /* ready to consume more filters */
9034 state
= IF_STATE_ACTION
;
9039 if (state
!= IF_STATE_ACTION
)
9049 free_filters_list(filters
);
9056 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
9062 * Since this is called in perf_ioctl() path, we're already holding
9065 lockdep_assert_held(&event
->ctx
->mutex
);
9067 if (WARN_ON_ONCE(event
->parent
))
9070 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
9072 goto fail_clear_files
;
9074 ret
= event
->pmu
->addr_filters_validate(&filters
);
9076 goto fail_free_filters
;
9078 /* remove existing filters, if any */
9079 perf_addr_filters_splice(event
, &filters
);
9081 /* install new filters */
9082 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
9087 free_filters_list(&filters
);
9090 event
->addr_filters
.nr_file_filters
= 0;
9095 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
9100 filter_str
= strndup_user(arg
, PAGE_SIZE
);
9101 if (IS_ERR(filter_str
))
9102 return PTR_ERR(filter_str
);
9104 #ifdef CONFIG_EVENT_TRACING
9105 if (perf_event_is_tracing(event
)) {
9106 struct perf_event_context
*ctx
= event
->ctx
;
9109 * Beware, here be dragons!!
9111 * the tracepoint muck will deadlock against ctx->mutex, but
9112 * the tracepoint stuff does not actually need it. So
9113 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
9114 * already have a reference on ctx.
9116 * This can result in event getting moved to a different ctx,
9117 * but that does not affect the tracepoint state.
9119 mutex_unlock(&ctx
->mutex
);
9120 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
9121 mutex_lock(&ctx
->mutex
);
9124 if (has_addr_filter(event
))
9125 ret
= perf_event_set_addr_filter(event
, filter_str
);
9132 * hrtimer based swevent callback
9135 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
9137 enum hrtimer_restart ret
= HRTIMER_RESTART
;
9138 struct perf_sample_data data
;
9139 struct pt_regs
*regs
;
9140 struct perf_event
*event
;
9143 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
9145 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
9146 return HRTIMER_NORESTART
;
9148 event
->pmu
->read(event
);
9150 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
9151 regs
= get_irq_regs();
9153 if (regs
&& !perf_exclude_event(event
, regs
)) {
9154 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
9155 if (__perf_event_overflow(event
, 1, &data
, regs
))
9156 ret
= HRTIMER_NORESTART
;
9159 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
9160 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
9165 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
9167 struct hw_perf_event
*hwc
= &event
->hw
;
9170 if (!is_sampling_event(event
))
9173 period
= local64_read(&hwc
->period_left
);
9178 local64_set(&hwc
->period_left
, 0);
9180 period
= max_t(u64
, 10000, hwc
->sample_period
);
9182 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
9183 HRTIMER_MODE_REL_PINNED
);
9186 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
9188 struct hw_perf_event
*hwc
= &event
->hw
;
9190 if (is_sampling_event(event
)) {
9191 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
9192 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
9194 hrtimer_cancel(&hwc
->hrtimer
);
9198 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
9200 struct hw_perf_event
*hwc
= &event
->hw
;
9202 if (!is_sampling_event(event
))
9205 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
9206 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
9209 * Since hrtimers have a fixed rate, we can do a static freq->period
9210 * mapping and avoid the whole period adjust feedback stuff.
9212 if (event
->attr
.freq
) {
9213 long freq
= event
->attr
.sample_freq
;
9215 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
9216 hwc
->sample_period
= event
->attr
.sample_period
;
9217 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9218 hwc
->last_period
= hwc
->sample_period
;
9219 event
->attr
.freq
= 0;
9224 * Software event: cpu wall time clock
9227 static void cpu_clock_event_update(struct perf_event
*event
)
9232 now
= local_clock();
9233 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9234 local64_add(now
- prev
, &event
->count
);
9237 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
9239 local64_set(&event
->hw
.prev_count
, local_clock());
9240 perf_swevent_start_hrtimer(event
);
9243 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
9245 perf_swevent_cancel_hrtimer(event
);
9246 cpu_clock_event_update(event
);
9249 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
9251 if (flags
& PERF_EF_START
)
9252 cpu_clock_event_start(event
, flags
);
9253 perf_event_update_userpage(event
);
9258 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
9260 cpu_clock_event_stop(event
, flags
);
9263 static void cpu_clock_event_read(struct perf_event
*event
)
9265 cpu_clock_event_update(event
);
9268 static int cpu_clock_event_init(struct perf_event
*event
)
9270 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9273 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
9277 * no branch sampling for software events
9279 if (has_branch_stack(event
))
9282 perf_swevent_init_hrtimer(event
);
9287 static struct pmu perf_cpu_clock
= {
9288 .task_ctx_nr
= perf_sw_context
,
9290 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9292 .event_init
= cpu_clock_event_init
,
9293 .add
= cpu_clock_event_add
,
9294 .del
= cpu_clock_event_del
,
9295 .start
= cpu_clock_event_start
,
9296 .stop
= cpu_clock_event_stop
,
9297 .read
= cpu_clock_event_read
,
9301 * Software event: task time clock
9304 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
9309 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9311 local64_add(delta
, &event
->count
);
9314 static void task_clock_event_start(struct perf_event
*event
, int flags
)
9316 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
9317 perf_swevent_start_hrtimer(event
);
9320 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
9322 perf_swevent_cancel_hrtimer(event
);
9323 task_clock_event_update(event
, event
->ctx
->time
);
9326 static int task_clock_event_add(struct perf_event
*event
, int flags
)
9328 if (flags
& PERF_EF_START
)
9329 task_clock_event_start(event
, flags
);
9330 perf_event_update_userpage(event
);
9335 static void task_clock_event_del(struct perf_event
*event
, int flags
)
9337 task_clock_event_stop(event
, PERF_EF_UPDATE
);
9340 static void task_clock_event_read(struct perf_event
*event
)
9342 u64 now
= perf_clock();
9343 u64 delta
= now
- event
->ctx
->timestamp
;
9344 u64 time
= event
->ctx
->time
+ delta
;
9346 task_clock_event_update(event
, time
);
9349 static int task_clock_event_init(struct perf_event
*event
)
9351 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9354 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
9358 * no branch sampling for software events
9360 if (has_branch_stack(event
))
9363 perf_swevent_init_hrtimer(event
);
9368 static struct pmu perf_task_clock
= {
9369 .task_ctx_nr
= perf_sw_context
,
9371 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9373 .event_init
= task_clock_event_init
,
9374 .add
= task_clock_event_add
,
9375 .del
= task_clock_event_del
,
9376 .start
= task_clock_event_start
,
9377 .stop
= task_clock_event_stop
,
9378 .read
= task_clock_event_read
,
9381 static void perf_pmu_nop_void(struct pmu
*pmu
)
9385 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
9389 static int perf_pmu_nop_int(struct pmu
*pmu
)
9394 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
9396 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
9398 __this_cpu_write(nop_txn_flags
, flags
);
9400 if (flags
& ~PERF_PMU_TXN_ADD
)
9403 perf_pmu_disable(pmu
);
9406 static int perf_pmu_commit_txn(struct pmu
*pmu
)
9408 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
9410 __this_cpu_write(nop_txn_flags
, 0);
9412 if (flags
& ~PERF_PMU_TXN_ADD
)
9415 perf_pmu_enable(pmu
);
9419 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
9421 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
9423 __this_cpu_write(nop_txn_flags
, 0);
9425 if (flags
& ~PERF_PMU_TXN_ADD
)
9428 perf_pmu_enable(pmu
);
9431 static int perf_event_idx_default(struct perf_event
*event
)
9437 * Ensures all contexts with the same task_ctx_nr have the same
9438 * pmu_cpu_context too.
9440 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
9447 list_for_each_entry(pmu
, &pmus
, entry
) {
9448 if (pmu
->task_ctx_nr
== ctxn
)
9449 return pmu
->pmu_cpu_context
;
9455 static void free_pmu_context(struct pmu
*pmu
)
9458 * Static contexts such as perf_sw_context have a global lifetime
9459 * and may be shared between different PMUs. Avoid freeing them
9460 * when a single PMU is going away.
9462 if (pmu
->task_ctx_nr
> perf_invalid_context
)
9465 free_percpu(pmu
->pmu_cpu_context
);
9469 * Let userspace know that this PMU supports address range filtering:
9471 static ssize_t
nr_addr_filters_show(struct device
*dev
,
9472 struct device_attribute
*attr
,
9475 struct pmu
*pmu
= dev_get_drvdata(dev
);
9477 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
9479 DEVICE_ATTR_RO(nr_addr_filters
);
9481 static struct idr pmu_idr
;
9484 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
9486 struct pmu
*pmu
= dev_get_drvdata(dev
);
9488 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
9490 static DEVICE_ATTR_RO(type
);
9493 perf_event_mux_interval_ms_show(struct device
*dev
,
9494 struct device_attribute
*attr
,
9497 struct pmu
*pmu
= dev_get_drvdata(dev
);
9499 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
9502 static DEFINE_MUTEX(mux_interval_mutex
);
9505 perf_event_mux_interval_ms_store(struct device
*dev
,
9506 struct device_attribute
*attr
,
9507 const char *buf
, size_t count
)
9509 struct pmu
*pmu
= dev_get_drvdata(dev
);
9510 int timer
, cpu
, ret
;
9512 ret
= kstrtoint(buf
, 0, &timer
);
9519 /* same value, noting to do */
9520 if (timer
== pmu
->hrtimer_interval_ms
)
9523 mutex_lock(&mux_interval_mutex
);
9524 pmu
->hrtimer_interval_ms
= timer
;
9526 /* update all cpuctx for this PMU */
9528 for_each_online_cpu(cpu
) {
9529 struct perf_cpu_context
*cpuctx
;
9530 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9531 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
9533 cpu_function_call(cpu
,
9534 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
9537 mutex_unlock(&mux_interval_mutex
);
9541 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
9543 static struct attribute
*pmu_dev_attrs
[] = {
9544 &dev_attr_type
.attr
,
9545 &dev_attr_perf_event_mux_interval_ms
.attr
,
9548 ATTRIBUTE_GROUPS(pmu_dev
);
9550 static int pmu_bus_running
;
9551 static struct bus_type pmu_bus
= {
9552 .name
= "event_source",
9553 .dev_groups
= pmu_dev_groups
,
9556 static void pmu_dev_release(struct device
*dev
)
9561 static int pmu_dev_alloc(struct pmu
*pmu
)
9565 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9569 pmu
->dev
->groups
= pmu
->attr_groups
;
9570 device_initialize(pmu
->dev
);
9571 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9575 dev_set_drvdata(pmu
->dev
, pmu
);
9576 pmu
->dev
->bus
= &pmu_bus
;
9577 pmu
->dev
->release
= pmu_dev_release
;
9578 ret
= device_add(pmu
->dev
);
9582 /* For PMUs with address filters, throw in an extra attribute: */
9583 if (pmu
->nr_addr_filters
)
9584 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9593 device_del(pmu
->dev
);
9596 put_device(pmu
->dev
);
9600 static struct lock_class_key cpuctx_mutex
;
9601 static struct lock_class_key cpuctx_lock
;
9603 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9607 mutex_lock(&pmus_lock
);
9609 pmu
->pmu_disable_count
= alloc_percpu(int);
9610 if (!pmu
->pmu_disable_count
)
9619 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9627 if (pmu_bus_running
) {
9628 ret
= pmu_dev_alloc(pmu
);
9634 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9635 static int hw_context_taken
= 0;
9638 * Other than systems with heterogeneous CPUs, it never makes
9639 * sense for two PMUs to share perf_hw_context. PMUs which are
9640 * uncore must use perf_invalid_context.
9642 if (WARN_ON_ONCE(hw_context_taken
&&
9643 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9644 pmu
->task_ctx_nr
= perf_invalid_context
;
9646 hw_context_taken
= 1;
9649 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9650 if (pmu
->pmu_cpu_context
)
9651 goto got_cpu_context
;
9654 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9655 if (!pmu
->pmu_cpu_context
)
9658 for_each_possible_cpu(cpu
) {
9659 struct perf_cpu_context
*cpuctx
;
9661 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9662 __perf_event_init_context(&cpuctx
->ctx
);
9663 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9664 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9665 cpuctx
->ctx
.pmu
= pmu
;
9666 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9668 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9672 if (!pmu
->start_txn
) {
9673 if (pmu
->pmu_enable
) {
9675 * If we have pmu_enable/pmu_disable calls, install
9676 * transaction stubs that use that to try and batch
9677 * hardware accesses.
9679 pmu
->start_txn
= perf_pmu_start_txn
;
9680 pmu
->commit_txn
= perf_pmu_commit_txn
;
9681 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9683 pmu
->start_txn
= perf_pmu_nop_txn
;
9684 pmu
->commit_txn
= perf_pmu_nop_int
;
9685 pmu
->cancel_txn
= perf_pmu_nop_void
;
9689 if (!pmu
->pmu_enable
) {
9690 pmu
->pmu_enable
= perf_pmu_nop_void
;
9691 pmu
->pmu_disable
= perf_pmu_nop_void
;
9694 if (!pmu
->event_idx
)
9695 pmu
->event_idx
= perf_event_idx_default
;
9697 list_add_rcu(&pmu
->entry
, &pmus
);
9698 atomic_set(&pmu
->exclusive_cnt
, 0);
9701 mutex_unlock(&pmus_lock
);
9706 device_del(pmu
->dev
);
9707 put_device(pmu
->dev
);
9710 if (pmu
->type
>= PERF_TYPE_MAX
)
9711 idr_remove(&pmu_idr
, pmu
->type
);
9714 free_percpu(pmu
->pmu_disable_count
);
9717 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9719 void perf_pmu_unregister(struct pmu
*pmu
)
9721 mutex_lock(&pmus_lock
);
9722 list_del_rcu(&pmu
->entry
);
9725 * We dereference the pmu list under both SRCU and regular RCU, so
9726 * synchronize against both of those.
9728 synchronize_srcu(&pmus_srcu
);
9731 free_percpu(pmu
->pmu_disable_count
);
9732 if (pmu
->type
>= PERF_TYPE_MAX
)
9733 idr_remove(&pmu_idr
, pmu
->type
);
9734 if (pmu_bus_running
) {
9735 if (pmu
->nr_addr_filters
)
9736 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9737 device_del(pmu
->dev
);
9738 put_device(pmu
->dev
);
9740 free_pmu_context(pmu
);
9741 mutex_unlock(&pmus_lock
);
9743 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9745 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9747 struct perf_event_context
*ctx
= NULL
;
9750 if (!try_module_get(pmu
->module
))
9754 * A number of pmu->event_init() methods iterate the sibling_list to,
9755 * for example, validate if the group fits on the PMU. Therefore,
9756 * if this is a sibling event, acquire the ctx->mutex to protect
9759 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
9761 * This ctx->mutex can nest when we're called through
9762 * inheritance. See the perf_event_ctx_lock_nested() comment.
9764 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9765 SINGLE_DEPTH_NESTING
);
9770 ret
= pmu
->event_init(event
);
9773 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9776 module_put(pmu
->module
);
9781 static struct pmu
*perf_init_event(struct perf_event
*event
)
9787 idx
= srcu_read_lock(&pmus_srcu
);
9789 /* Try parent's PMU first: */
9790 if (event
->parent
&& event
->parent
->pmu
) {
9791 pmu
= event
->parent
->pmu
;
9792 ret
= perf_try_init_event(pmu
, event
);
9798 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9801 ret
= perf_try_init_event(pmu
, event
);
9807 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9808 ret
= perf_try_init_event(pmu
, event
);
9812 if (ret
!= -ENOENT
) {
9817 pmu
= ERR_PTR(-ENOENT
);
9819 srcu_read_unlock(&pmus_srcu
, idx
);
9824 static void attach_sb_event(struct perf_event
*event
)
9826 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9828 raw_spin_lock(&pel
->lock
);
9829 list_add_rcu(&event
->sb_list
, &pel
->list
);
9830 raw_spin_unlock(&pel
->lock
);
9834 * We keep a list of all !task (and therefore per-cpu) events
9835 * that need to receive side-band records.
9837 * This avoids having to scan all the various PMU per-cpu contexts
9840 static void account_pmu_sb_event(struct perf_event
*event
)
9842 if (is_sb_event(event
))
9843 attach_sb_event(event
);
9846 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9851 if (is_cgroup_event(event
))
9852 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9855 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9856 static void account_freq_event_nohz(void)
9858 #ifdef CONFIG_NO_HZ_FULL
9859 /* Lock so we don't race with concurrent unaccount */
9860 spin_lock(&nr_freq_lock
);
9861 if (atomic_inc_return(&nr_freq_events
) == 1)
9862 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9863 spin_unlock(&nr_freq_lock
);
9867 static void account_freq_event(void)
9869 if (tick_nohz_full_enabled())
9870 account_freq_event_nohz();
9872 atomic_inc(&nr_freq_events
);
9876 static void account_event(struct perf_event
*event
)
9883 if (event
->attach_state
& PERF_ATTACH_TASK
)
9885 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9886 atomic_inc(&nr_mmap_events
);
9887 if (event
->attr
.comm
)
9888 atomic_inc(&nr_comm_events
);
9889 if (event
->attr
.namespaces
)
9890 atomic_inc(&nr_namespaces_events
);
9891 if (event
->attr
.task
)
9892 atomic_inc(&nr_task_events
);
9893 if (event
->attr
.freq
)
9894 account_freq_event();
9895 if (event
->attr
.context_switch
) {
9896 atomic_inc(&nr_switch_events
);
9899 if (has_branch_stack(event
))
9901 if (is_cgroup_event(event
))
9906 * We need the mutex here because static_branch_enable()
9907 * must complete *before* the perf_sched_count increment
9910 if (atomic_inc_not_zero(&perf_sched_count
))
9913 mutex_lock(&perf_sched_mutex
);
9914 if (!atomic_read(&perf_sched_count
)) {
9915 static_branch_enable(&perf_sched_events
);
9917 * Guarantee that all CPUs observe they key change and
9918 * call the perf scheduling hooks before proceeding to
9919 * install events that need them.
9924 * Now that we have waited for the sync_sched(), allow further
9925 * increments to by-pass the mutex.
9927 atomic_inc(&perf_sched_count
);
9928 mutex_unlock(&perf_sched_mutex
);
9932 account_event_cpu(event
, event
->cpu
);
9934 account_pmu_sb_event(event
);
9938 * Allocate and initialize an event structure
9940 static struct perf_event
*
9941 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9942 struct task_struct
*task
,
9943 struct perf_event
*group_leader
,
9944 struct perf_event
*parent_event
,
9945 perf_overflow_handler_t overflow_handler
,
9946 void *context
, int cgroup_fd
)
9949 struct perf_event
*event
;
9950 struct hw_perf_event
*hwc
;
9953 if ((unsigned)cpu
>= nr_cpu_ids
) {
9954 if (!task
|| cpu
!= -1)
9955 return ERR_PTR(-EINVAL
);
9958 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9960 return ERR_PTR(-ENOMEM
);
9963 * Single events are their own group leaders, with an
9964 * empty sibling list:
9967 group_leader
= event
;
9969 mutex_init(&event
->child_mutex
);
9970 INIT_LIST_HEAD(&event
->child_list
);
9972 INIT_LIST_HEAD(&event
->event_entry
);
9973 INIT_LIST_HEAD(&event
->sibling_list
);
9974 INIT_LIST_HEAD(&event
->active_list
);
9975 init_event_group(event
);
9976 INIT_LIST_HEAD(&event
->rb_entry
);
9977 INIT_LIST_HEAD(&event
->active_entry
);
9978 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9979 INIT_HLIST_NODE(&event
->hlist_entry
);
9982 init_waitqueue_head(&event
->waitq
);
9983 init_irq_work(&event
->pending
, perf_pending_event
);
9985 mutex_init(&event
->mmap_mutex
);
9986 raw_spin_lock_init(&event
->addr_filters
.lock
);
9988 atomic_long_set(&event
->refcount
, 1);
9990 event
->attr
= *attr
;
9991 event
->group_leader
= group_leader
;
9995 event
->parent
= parent_event
;
9997 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9998 event
->id
= atomic64_inc_return(&perf_event_id
);
10000 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10003 event
->attach_state
= PERF_ATTACH_TASK
;
10005 * XXX pmu::event_init needs to know what task to account to
10006 * and we cannot use the ctx information because we need the
10007 * pmu before we get a ctx.
10009 get_task_struct(task
);
10010 event
->hw
.target
= task
;
10013 event
->clock
= &local_clock
;
10015 event
->clock
= parent_event
->clock
;
10017 if (!overflow_handler
&& parent_event
) {
10018 overflow_handler
= parent_event
->overflow_handler
;
10019 context
= parent_event
->overflow_handler_context
;
10020 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
10021 if (overflow_handler
== bpf_overflow_handler
) {
10022 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
10024 if (IS_ERR(prog
)) {
10025 err
= PTR_ERR(prog
);
10028 event
->prog
= prog
;
10029 event
->orig_overflow_handler
=
10030 parent_event
->orig_overflow_handler
;
10035 if (overflow_handler
) {
10036 event
->overflow_handler
= overflow_handler
;
10037 event
->overflow_handler_context
= context
;
10038 } else if (is_write_backward(event
)){
10039 event
->overflow_handler
= perf_event_output_backward
;
10040 event
->overflow_handler_context
= NULL
;
10042 event
->overflow_handler
= perf_event_output_forward
;
10043 event
->overflow_handler_context
= NULL
;
10046 perf_event__state_init(event
);
10051 hwc
->sample_period
= attr
->sample_period
;
10052 if (attr
->freq
&& attr
->sample_freq
)
10053 hwc
->sample_period
= 1;
10054 hwc
->last_period
= hwc
->sample_period
;
10056 local64_set(&hwc
->period_left
, hwc
->sample_period
);
10059 * We currently do not support PERF_SAMPLE_READ on inherited events.
10060 * See perf_output_read().
10062 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
10065 if (!has_branch_stack(event
))
10066 event
->attr
.branch_sample_type
= 0;
10068 if (cgroup_fd
!= -1) {
10069 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
10074 pmu
= perf_init_event(event
);
10076 err
= PTR_ERR(pmu
);
10080 err
= exclusive_event_init(event
);
10084 if (has_addr_filter(event
)) {
10085 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
10086 sizeof(unsigned long),
10088 if (!event
->addr_filters_offs
) {
10093 /* force hw sync on the address filters */
10094 event
->addr_filters_gen
= 1;
10097 if (!event
->parent
) {
10098 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
10099 err
= get_callchain_buffers(attr
->sample_max_stack
);
10101 goto err_addr_filters
;
10105 /* symmetric to unaccount_event() in _free_event() */
10106 account_event(event
);
10111 kfree(event
->addr_filters_offs
);
10114 exclusive_event_destroy(event
);
10117 if (event
->destroy
)
10118 event
->destroy(event
);
10119 module_put(pmu
->module
);
10121 if (is_cgroup_event(event
))
10122 perf_detach_cgroup(event
);
10124 put_pid_ns(event
->ns
);
10125 if (event
->hw
.target
)
10126 put_task_struct(event
->hw
.target
);
10129 return ERR_PTR(err
);
10132 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
10133 struct perf_event_attr
*attr
)
10138 if (!access_ok(uattr
, PERF_ATTR_SIZE_VER0
))
10142 * zero the full structure, so that a short copy will be nice.
10144 memset(attr
, 0, sizeof(*attr
));
10146 ret
= get_user(size
, &uattr
->size
);
10150 if (size
> PAGE_SIZE
) /* silly large */
10153 if (!size
) /* abi compat */
10154 size
= PERF_ATTR_SIZE_VER0
;
10156 if (size
< PERF_ATTR_SIZE_VER0
)
10160 * If we're handed a bigger struct than we know of,
10161 * ensure all the unknown bits are 0 - i.e. new
10162 * user-space does not rely on any kernel feature
10163 * extensions we dont know about yet.
10165 if (size
> sizeof(*attr
)) {
10166 unsigned char __user
*addr
;
10167 unsigned char __user
*end
;
10170 addr
= (void __user
*)uattr
+ sizeof(*attr
);
10171 end
= (void __user
*)uattr
+ size
;
10173 for (; addr
< end
; addr
++) {
10174 ret
= get_user(val
, addr
);
10180 size
= sizeof(*attr
);
10183 ret
= copy_from_user(attr
, uattr
, size
);
10189 if (attr
->__reserved_1
)
10192 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
10195 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
10198 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
10199 u64 mask
= attr
->branch_sample_type
;
10201 /* only using defined bits */
10202 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
10205 /* at least one branch bit must be set */
10206 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
10209 /* propagate priv level, when not set for branch */
10210 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
10212 /* exclude_kernel checked on syscall entry */
10213 if (!attr
->exclude_kernel
)
10214 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
10216 if (!attr
->exclude_user
)
10217 mask
|= PERF_SAMPLE_BRANCH_USER
;
10219 if (!attr
->exclude_hv
)
10220 mask
|= PERF_SAMPLE_BRANCH_HV
;
10222 * adjust user setting (for HW filter setup)
10224 attr
->branch_sample_type
= mask
;
10226 /* privileged levels capture (kernel, hv): check permissions */
10227 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
10228 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10232 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
10233 ret
= perf_reg_validate(attr
->sample_regs_user
);
10238 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
10239 if (!arch_perf_have_user_stack_dump())
10243 * We have __u32 type for the size, but so far
10244 * we can only use __u16 as maximum due to the
10245 * __u16 sample size limit.
10247 if (attr
->sample_stack_user
>= USHRT_MAX
)
10249 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
10253 if (!attr
->sample_max_stack
)
10254 attr
->sample_max_stack
= sysctl_perf_event_max_stack
;
10256 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
10257 ret
= perf_reg_validate(attr
->sample_regs_intr
);
10262 put_user(sizeof(*attr
), &uattr
->size
);
10268 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
10270 struct ring_buffer
*rb
= NULL
;
10276 /* don't allow circular references */
10277 if (event
== output_event
)
10281 * Don't allow cross-cpu buffers
10283 if (output_event
->cpu
!= event
->cpu
)
10287 * If its not a per-cpu rb, it must be the same task.
10289 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
10293 * Mixing clocks in the same buffer is trouble you don't need.
10295 if (output_event
->clock
!= event
->clock
)
10299 * Either writing ring buffer from beginning or from end.
10300 * Mixing is not allowed.
10302 if (is_write_backward(output_event
) != is_write_backward(event
))
10306 * If both events generate aux data, they must be on the same PMU
10308 if (has_aux(event
) && has_aux(output_event
) &&
10309 event
->pmu
!= output_event
->pmu
)
10313 mutex_lock(&event
->mmap_mutex
);
10314 /* Can't redirect output if we've got an active mmap() */
10315 if (atomic_read(&event
->mmap_count
))
10318 if (output_event
) {
10319 /* get the rb we want to redirect to */
10320 rb
= ring_buffer_get(output_event
);
10325 ring_buffer_attach(event
, rb
);
10329 mutex_unlock(&event
->mmap_mutex
);
10335 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
10341 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
10344 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
10346 bool nmi_safe
= false;
10349 case CLOCK_MONOTONIC
:
10350 event
->clock
= &ktime_get_mono_fast_ns
;
10354 case CLOCK_MONOTONIC_RAW
:
10355 event
->clock
= &ktime_get_raw_fast_ns
;
10359 case CLOCK_REALTIME
:
10360 event
->clock
= &ktime_get_real_ns
;
10363 case CLOCK_BOOTTIME
:
10364 event
->clock
= &ktime_get_boot_ns
;
10368 event
->clock
= &ktime_get_tai_ns
;
10375 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
10382 * Variation on perf_event_ctx_lock_nested(), except we take two context
10385 static struct perf_event_context
*
10386 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
10387 struct perf_event_context
*ctx
)
10389 struct perf_event_context
*gctx
;
10393 gctx
= READ_ONCE(group_leader
->ctx
);
10394 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
10400 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
10402 if (group_leader
->ctx
!= gctx
) {
10403 mutex_unlock(&ctx
->mutex
);
10404 mutex_unlock(&gctx
->mutex
);
10413 * sys_perf_event_open - open a performance event, associate it to a task/cpu
10415 * @attr_uptr: event_id type attributes for monitoring/sampling
10418 * @group_fd: group leader event fd
10420 SYSCALL_DEFINE5(perf_event_open
,
10421 struct perf_event_attr __user
*, attr_uptr
,
10422 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
10424 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
10425 struct perf_event
*event
, *sibling
;
10426 struct perf_event_attr attr
;
10427 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
10428 struct file
*event_file
= NULL
;
10429 struct fd group
= {NULL
, 0};
10430 struct task_struct
*task
= NULL
;
10433 int move_group
= 0;
10435 int f_flags
= O_RDWR
;
10436 int cgroup_fd
= -1;
10438 /* for future expandability... */
10439 if (flags
& ~PERF_FLAG_ALL
)
10442 err
= perf_copy_attr(attr_uptr
, &attr
);
10446 if (!attr
.exclude_kernel
) {
10447 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10451 if (attr
.namespaces
) {
10452 if (!capable(CAP_SYS_ADMIN
))
10457 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
10460 if (attr
.sample_period
& (1ULL << 63))
10464 /* Only privileged users can get physical addresses */
10465 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
10466 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10470 * In cgroup mode, the pid argument is used to pass the fd
10471 * opened to the cgroup directory in cgroupfs. The cpu argument
10472 * designates the cpu on which to monitor threads from that
10475 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
10478 if (flags
& PERF_FLAG_FD_CLOEXEC
)
10479 f_flags
|= O_CLOEXEC
;
10481 event_fd
= get_unused_fd_flags(f_flags
);
10485 if (group_fd
!= -1) {
10486 err
= perf_fget_light(group_fd
, &group
);
10489 group_leader
= group
.file
->private_data
;
10490 if (flags
& PERF_FLAG_FD_OUTPUT
)
10491 output_event
= group_leader
;
10492 if (flags
& PERF_FLAG_FD_NO_GROUP
)
10493 group_leader
= NULL
;
10496 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
10497 task
= find_lively_task_by_vpid(pid
);
10498 if (IS_ERR(task
)) {
10499 err
= PTR_ERR(task
);
10504 if (task
&& group_leader
&&
10505 group_leader
->attr
.inherit
!= attr
.inherit
) {
10511 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
10516 * Reuse ptrace permission checks for now.
10518 * We must hold cred_guard_mutex across this and any potential
10519 * perf_install_in_context() call for this new event to
10520 * serialize against exec() altering our credentials (and the
10521 * perf_event_exit_task() that could imply).
10524 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
10528 if (flags
& PERF_FLAG_PID_CGROUP
)
10531 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
10532 NULL
, NULL
, cgroup_fd
);
10533 if (IS_ERR(event
)) {
10534 err
= PTR_ERR(event
);
10538 if (is_sampling_event(event
)) {
10539 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
10546 * Special case software events and allow them to be part of
10547 * any hardware group.
10551 if (attr
.use_clockid
) {
10552 err
= perf_event_set_clock(event
, attr
.clockid
);
10557 if (pmu
->task_ctx_nr
== perf_sw_context
)
10558 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
10560 if (group_leader
) {
10561 if (is_software_event(event
) &&
10562 !in_software_context(group_leader
)) {
10564 * If the event is a sw event, but the group_leader
10565 * is on hw context.
10567 * Allow the addition of software events to hw
10568 * groups, this is safe because software events
10569 * never fail to schedule.
10571 pmu
= group_leader
->ctx
->pmu
;
10572 } else if (!is_software_event(event
) &&
10573 is_software_event(group_leader
) &&
10574 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10576 * In case the group is a pure software group, and we
10577 * try to add a hardware event, move the whole group to
10578 * the hardware context.
10585 * Get the target context (task or percpu):
10587 ctx
= find_get_context(pmu
, task
, event
);
10589 err
= PTR_ERR(ctx
);
10593 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10599 * Look up the group leader (we will attach this event to it):
10601 if (group_leader
) {
10605 * Do not allow a recursive hierarchy (this new sibling
10606 * becoming part of another group-sibling):
10608 if (group_leader
->group_leader
!= group_leader
)
10611 /* All events in a group should have the same clock */
10612 if (group_leader
->clock
!= event
->clock
)
10616 * Make sure we're both events for the same CPU;
10617 * grouping events for different CPUs is broken; since
10618 * you can never concurrently schedule them anyhow.
10620 if (group_leader
->cpu
!= event
->cpu
)
10624 * Make sure we're both on the same task, or both
10627 if (group_leader
->ctx
->task
!= ctx
->task
)
10631 * Do not allow to attach to a group in a different task
10632 * or CPU context. If we're moving SW events, we'll fix
10633 * this up later, so allow that.
10635 if (!move_group
&& group_leader
->ctx
!= ctx
)
10639 * Only a group leader can be exclusive or pinned
10641 if (attr
.exclusive
|| attr
.pinned
)
10645 if (output_event
) {
10646 err
= perf_event_set_output(event
, output_event
);
10651 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10653 if (IS_ERR(event_file
)) {
10654 err
= PTR_ERR(event_file
);
10660 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10662 if (gctx
->task
== TASK_TOMBSTONE
) {
10668 * Check if we raced against another sys_perf_event_open() call
10669 * moving the software group underneath us.
10671 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10673 * If someone moved the group out from under us, check
10674 * if this new event wound up on the same ctx, if so
10675 * its the regular !move_group case, otherwise fail.
10681 perf_event_ctx_unlock(group_leader
, gctx
);
10686 mutex_lock(&ctx
->mutex
);
10689 if (ctx
->task
== TASK_TOMBSTONE
) {
10694 if (!perf_event_validate_size(event
)) {
10701 * Check if the @cpu we're creating an event for is online.
10703 * We use the perf_cpu_context::ctx::mutex to serialize against
10704 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10706 struct perf_cpu_context
*cpuctx
=
10707 container_of(ctx
, struct perf_cpu_context
, ctx
);
10709 if (!cpuctx
->online
) {
10717 * Must be under the same ctx::mutex as perf_install_in_context(),
10718 * because we need to serialize with concurrent event creation.
10720 if (!exclusive_event_installable(event
, ctx
)) {
10721 /* exclusive and group stuff are assumed mutually exclusive */
10722 WARN_ON_ONCE(move_group
);
10728 WARN_ON_ONCE(ctx
->parent_ctx
);
10731 * This is the point on no return; we cannot fail hereafter. This is
10732 * where we start modifying current state.
10737 * See perf_event_ctx_lock() for comments on the details
10738 * of swizzling perf_event::ctx.
10740 perf_remove_from_context(group_leader
, 0);
10743 for_each_sibling_event(sibling
, group_leader
) {
10744 perf_remove_from_context(sibling
, 0);
10749 * Wait for everybody to stop referencing the events through
10750 * the old lists, before installing it on new lists.
10755 * Install the group siblings before the group leader.
10757 * Because a group leader will try and install the entire group
10758 * (through the sibling list, which is still in-tact), we can
10759 * end up with siblings installed in the wrong context.
10761 * By installing siblings first we NO-OP because they're not
10762 * reachable through the group lists.
10764 for_each_sibling_event(sibling
, group_leader
) {
10765 perf_event__state_init(sibling
);
10766 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10771 * Removing from the context ends up with disabled
10772 * event. What we want here is event in the initial
10773 * startup state, ready to be add into new context.
10775 perf_event__state_init(group_leader
);
10776 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10781 * Precalculate sample_data sizes; do while holding ctx::mutex such
10782 * that we're serialized against further additions and before
10783 * perf_install_in_context() which is the point the event is active and
10784 * can use these values.
10786 perf_event__header_size(event
);
10787 perf_event__id_header_size(event
);
10789 event
->owner
= current
;
10791 perf_install_in_context(ctx
, event
, event
->cpu
);
10792 perf_unpin_context(ctx
);
10795 perf_event_ctx_unlock(group_leader
, gctx
);
10796 mutex_unlock(&ctx
->mutex
);
10799 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10800 put_task_struct(task
);
10803 mutex_lock(¤t
->perf_event_mutex
);
10804 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10805 mutex_unlock(¤t
->perf_event_mutex
);
10808 * Drop the reference on the group_event after placing the
10809 * new event on the sibling_list. This ensures destruction
10810 * of the group leader will find the pointer to itself in
10811 * perf_group_detach().
10814 fd_install(event_fd
, event_file
);
10819 perf_event_ctx_unlock(group_leader
, gctx
);
10820 mutex_unlock(&ctx
->mutex
);
10824 perf_unpin_context(ctx
);
10828 * If event_file is set, the fput() above will have called ->release()
10829 * and that will take care of freeing the event.
10835 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10838 put_task_struct(task
);
10842 put_unused_fd(event_fd
);
10847 * perf_event_create_kernel_counter
10849 * @attr: attributes of the counter to create
10850 * @cpu: cpu in which the counter is bound
10851 * @task: task to profile (NULL for percpu)
10853 struct perf_event
*
10854 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10855 struct task_struct
*task
,
10856 perf_overflow_handler_t overflow_handler
,
10859 struct perf_event_context
*ctx
;
10860 struct perf_event
*event
;
10864 * Get the target context (task or percpu):
10867 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10868 overflow_handler
, context
, -1);
10869 if (IS_ERR(event
)) {
10870 err
= PTR_ERR(event
);
10874 /* Mark owner so we could distinguish it from user events. */
10875 event
->owner
= TASK_TOMBSTONE
;
10877 ctx
= find_get_context(event
->pmu
, task
, event
);
10879 err
= PTR_ERR(ctx
);
10883 WARN_ON_ONCE(ctx
->parent_ctx
);
10884 mutex_lock(&ctx
->mutex
);
10885 if (ctx
->task
== TASK_TOMBSTONE
) {
10892 * Check if the @cpu we're creating an event for is online.
10894 * We use the perf_cpu_context::ctx::mutex to serialize against
10895 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10897 struct perf_cpu_context
*cpuctx
=
10898 container_of(ctx
, struct perf_cpu_context
, ctx
);
10899 if (!cpuctx
->online
) {
10905 if (!exclusive_event_installable(event
, ctx
)) {
10910 perf_install_in_context(ctx
, event
, cpu
);
10911 perf_unpin_context(ctx
);
10912 mutex_unlock(&ctx
->mutex
);
10917 mutex_unlock(&ctx
->mutex
);
10918 perf_unpin_context(ctx
);
10923 return ERR_PTR(err
);
10925 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10927 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10929 struct perf_event_context
*src_ctx
;
10930 struct perf_event_context
*dst_ctx
;
10931 struct perf_event
*event
, *tmp
;
10934 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10935 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10938 * See perf_event_ctx_lock() for comments on the details
10939 * of swizzling perf_event::ctx.
10941 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10942 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10944 perf_remove_from_context(event
, 0);
10945 unaccount_event_cpu(event
, src_cpu
);
10947 list_add(&event
->migrate_entry
, &events
);
10951 * Wait for the events to quiesce before re-instating them.
10956 * Re-instate events in 2 passes.
10958 * Skip over group leaders and only install siblings on this first
10959 * pass, siblings will not get enabled without a leader, however a
10960 * leader will enable its siblings, even if those are still on the old
10963 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10964 if (event
->group_leader
== event
)
10967 list_del(&event
->migrate_entry
);
10968 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10969 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10970 account_event_cpu(event
, dst_cpu
);
10971 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10976 * Once all the siblings are setup properly, install the group leaders
10979 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10980 list_del(&event
->migrate_entry
);
10981 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10982 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10983 account_event_cpu(event
, dst_cpu
);
10984 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10987 mutex_unlock(&dst_ctx
->mutex
);
10988 mutex_unlock(&src_ctx
->mutex
);
10990 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10992 static void sync_child_event(struct perf_event
*child_event
,
10993 struct task_struct
*child
)
10995 struct perf_event
*parent_event
= child_event
->parent
;
10998 if (child_event
->attr
.inherit_stat
)
10999 perf_event_read_event(child_event
, child
);
11001 child_val
= perf_event_count(child_event
);
11004 * Add back the child's count to the parent's count:
11006 atomic64_add(child_val
, &parent_event
->child_count
);
11007 atomic64_add(child_event
->total_time_enabled
,
11008 &parent_event
->child_total_time_enabled
);
11009 atomic64_add(child_event
->total_time_running
,
11010 &parent_event
->child_total_time_running
);
11014 perf_event_exit_event(struct perf_event
*child_event
,
11015 struct perf_event_context
*child_ctx
,
11016 struct task_struct
*child
)
11018 struct perf_event
*parent_event
= child_event
->parent
;
11021 * Do not destroy the 'original' grouping; because of the context
11022 * switch optimization the original events could've ended up in a
11023 * random child task.
11025 * If we were to destroy the original group, all group related
11026 * operations would cease to function properly after this random
11029 * Do destroy all inherited groups, we don't care about those
11030 * and being thorough is better.
11032 raw_spin_lock_irq(&child_ctx
->lock
);
11033 WARN_ON_ONCE(child_ctx
->is_active
);
11036 perf_group_detach(child_event
);
11037 list_del_event(child_event
, child_ctx
);
11038 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
11039 raw_spin_unlock_irq(&child_ctx
->lock
);
11042 * Parent events are governed by their filedesc, retain them.
11044 if (!parent_event
) {
11045 perf_event_wakeup(child_event
);
11049 * Child events can be cleaned up.
11052 sync_child_event(child_event
, child
);
11055 * Remove this event from the parent's list
11057 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
11058 mutex_lock(&parent_event
->child_mutex
);
11059 list_del_init(&child_event
->child_list
);
11060 mutex_unlock(&parent_event
->child_mutex
);
11063 * Kick perf_poll() for is_event_hup().
11065 perf_event_wakeup(parent_event
);
11066 free_event(child_event
);
11067 put_event(parent_event
);
11070 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
11072 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
11073 struct perf_event
*child_event
, *next
;
11075 WARN_ON_ONCE(child
!= current
);
11077 child_ctx
= perf_pin_task_context(child
, ctxn
);
11082 * In order to reduce the amount of tricky in ctx tear-down, we hold
11083 * ctx::mutex over the entire thing. This serializes against almost
11084 * everything that wants to access the ctx.
11086 * The exception is sys_perf_event_open() /
11087 * perf_event_create_kernel_count() which does find_get_context()
11088 * without ctx::mutex (it cannot because of the move_group double mutex
11089 * lock thing). See the comments in perf_install_in_context().
11091 mutex_lock(&child_ctx
->mutex
);
11094 * In a single ctx::lock section, de-schedule the events and detach the
11095 * context from the task such that we cannot ever get it scheduled back
11098 raw_spin_lock_irq(&child_ctx
->lock
);
11099 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
11102 * Now that the context is inactive, destroy the task <-> ctx relation
11103 * and mark the context dead.
11105 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
11106 put_ctx(child_ctx
); /* cannot be last */
11107 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
11108 put_task_struct(current
); /* cannot be last */
11110 clone_ctx
= unclone_ctx(child_ctx
);
11111 raw_spin_unlock_irq(&child_ctx
->lock
);
11114 put_ctx(clone_ctx
);
11117 * Report the task dead after unscheduling the events so that we
11118 * won't get any samples after PERF_RECORD_EXIT. We can however still
11119 * get a few PERF_RECORD_READ events.
11121 perf_event_task(child
, child_ctx
, 0);
11123 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
11124 perf_event_exit_event(child_event
, child_ctx
, child
);
11126 mutex_unlock(&child_ctx
->mutex
);
11128 put_ctx(child_ctx
);
11132 * When a child task exits, feed back event values to parent events.
11134 * Can be called with cred_guard_mutex held when called from
11135 * install_exec_creds().
11137 void perf_event_exit_task(struct task_struct
*child
)
11139 struct perf_event
*event
, *tmp
;
11142 mutex_lock(&child
->perf_event_mutex
);
11143 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
11145 list_del_init(&event
->owner_entry
);
11148 * Ensure the list deletion is visible before we clear
11149 * the owner, closes a race against perf_release() where
11150 * we need to serialize on the owner->perf_event_mutex.
11152 smp_store_release(&event
->owner
, NULL
);
11154 mutex_unlock(&child
->perf_event_mutex
);
11156 for_each_task_context_nr(ctxn
)
11157 perf_event_exit_task_context(child
, ctxn
);
11160 * The perf_event_exit_task_context calls perf_event_task
11161 * with child's task_ctx, which generates EXIT events for
11162 * child contexts and sets child->perf_event_ctxp[] to NULL.
11163 * At this point we need to send EXIT events to cpu contexts.
11165 perf_event_task(child
, NULL
, 0);
11168 static void perf_free_event(struct perf_event
*event
,
11169 struct perf_event_context
*ctx
)
11171 struct perf_event
*parent
= event
->parent
;
11173 if (WARN_ON_ONCE(!parent
))
11176 mutex_lock(&parent
->child_mutex
);
11177 list_del_init(&event
->child_list
);
11178 mutex_unlock(&parent
->child_mutex
);
11182 raw_spin_lock_irq(&ctx
->lock
);
11183 perf_group_detach(event
);
11184 list_del_event(event
, ctx
);
11185 raw_spin_unlock_irq(&ctx
->lock
);
11190 * Free an unexposed, unused context as created by inheritance by
11191 * perf_event_init_task below, used by fork() in case of fail.
11193 * Not all locks are strictly required, but take them anyway to be nice and
11194 * help out with the lockdep assertions.
11196 void perf_event_free_task(struct task_struct
*task
)
11198 struct perf_event_context
*ctx
;
11199 struct perf_event
*event
, *tmp
;
11202 for_each_task_context_nr(ctxn
) {
11203 ctx
= task
->perf_event_ctxp
[ctxn
];
11207 mutex_lock(&ctx
->mutex
);
11208 raw_spin_lock_irq(&ctx
->lock
);
11210 * Destroy the task <-> ctx relation and mark the context dead.
11212 * This is important because even though the task hasn't been
11213 * exposed yet the context has been (through child_list).
11215 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
11216 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
11217 put_task_struct(task
); /* cannot be last */
11218 raw_spin_unlock_irq(&ctx
->lock
);
11220 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
11221 perf_free_event(event
, ctx
);
11223 mutex_unlock(&ctx
->mutex
);
11228 void perf_event_delayed_put(struct task_struct
*task
)
11232 for_each_task_context_nr(ctxn
)
11233 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
11236 struct file
*perf_event_get(unsigned int fd
)
11240 file
= fget_raw(fd
);
11242 return ERR_PTR(-EBADF
);
11244 if (file
->f_op
!= &perf_fops
) {
11246 return ERR_PTR(-EBADF
);
11252 const struct perf_event
*perf_get_event(struct file
*file
)
11254 if (file
->f_op
!= &perf_fops
)
11255 return ERR_PTR(-EINVAL
);
11257 return file
->private_data
;
11260 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
11263 return ERR_PTR(-EINVAL
);
11265 return &event
->attr
;
11269 * Inherit an event from parent task to child task.
11272 * - valid pointer on success
11273 * - NULL for orphaned events
11274 * - IS_ERR() on error
11276 static struct perf_event
*
11277 inherit_event(struct perf_event
*parent_event
,
11278 struct task_struct
*parent
,
11279 struct perf_event_context
*parent_ctx
,
11280 struct task_struct
*child
,
11281 struct perf_event
*group_leader
,
11282 struct perf_event_context
*child_ctx
)
11284 enum perf_event_state parent_state
= parent_event
->state
;
11285 struct perf_event
*child_event
;
11286 unsigned long flags
;
11289 * Instead of creating recursive hierarchies of events,
11290 * we link inherited events back to the original parent,
11291 * which has a filp for sure, which we use as the reference
11294 if (parent_event
->parent
)
11295 parent_event
= parent_event
->parent
;
11297 child_event
= perf_event_alloc(&parent_event
->attr
,
11300 group_leader
, parent_event
,
11302 if (IS_ERR(child_event
))
11303 return child_event
;
11306 if ((child_event
->attach_state
& PERF_ATTACH_TASK_DATA
) &&
11307 !child_ctx
->task_ctx_data
) {
11308 struct pmu
*pmu
= child_event
->pmu
;
11310 child_ctx
->task_ctx_data
= kzalloc(pmu
->task_ctx_size
,
11312 if (!child_ctx
->task_ctx_data
) {
11313 free_event(child_event
);
11319 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
11320 * must be under the same lock in order to serialize against
11321 * perf_event_release_kernel(), such that either we must observe
11322 * is_orphaned_event() or they will observe us on the child_list.
11324 mutex_lock(&parent_event
->child_mutex
);
11325 if (is_orphaned_event(parent_event
) ||
11326 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
11327 mutex_unlock(&parent_event
->child_mutex
);
11328 /* task_ctx_data is freed with child_ctx */
11329 free_event(child_event
);
11333 get_ctx(child_ctx
);
11336 * Make the child state follow the state of the parent event,
11337 * not its attr.disabled bit. We hold the parent's mutex,
11338 * so we won't race with perf_event_{en, dis}able_family.
11340 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
11341 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
11343 child_event
->state
= PERF_EVENT_STATE_OFF
;
11345 if (parent_event
->attr
.freq
) {
11346 u64 sample_period
= parent_event
->hw
.sample_period
;
11347 struct hw_perf_event
*hwc
= &child_event
->hw
;
11349 hwc
->sample_period
= sample_period
;
11350 hwc
->last_period
= sample_period
;
11352 local64_set(&hwc
->period_left
, sample_period
);
11355 child_event
->ctx
= child_ctx
;
11356 child_event
->overflow_handler
= parent_event
->overflow_handler
;
11357 child_event
->overflow_handler_context
11358 = parent_event
->overflow_handler_context
;
11361 * Precalculate sample_data sizes
11363 perf_event__header_size(child_event
);
11364 perf_event__id_header_size(child_event
);
11367 * Link it up in the child's context:
11369 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
11370 add_event_to_ctx(child_event
, child_ctx
);
11371 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
11374 * Link this into the parent event's child list
11376 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
11377 mutex_unlock(&parent_event
->child_mutex
);
11379 return child_event
;
11383 * Inherits an event group.
11385 * This will quietly suppress orphaned events; !inherit_event() is not an error.
11386 * This matches with perf_event_release_kernel() removing all child events.
11392 static int inherit_group(struct perf_event
*parent_event
,
11393 struct task_struct
*parent
,
11394 struct perf_event_context
*parent_ctx
,
11395 struct task_struct
*child
,
11396 struct perf_event_context
*child_ctx
)
11398 struct perf_event
*leader
;
11399 struct perf_event
*sub
;
11400 struct perf_event
*child_ctr
;
11402 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
11403 child
, NULL
, child_ctx
);
11404 if (IS_ERR(leader
))
11405 return PTR_ERR(leader
);
11407 * @leader can be NULL here because of is_orphaned_event(). In this
11408 * case inherit_event() will create individual events, similar to what
11409 * perf_group_detach() would do anyway.
11411 for_each_sibling_event(sub
, parent_event
) {
11412 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
11413 child
, leader
, child_ctx
);
11414 if (IS_ERR(child_ctr
))
11415 return PTR_ERR(child_ctr
);
11421 * Creates the child task context and tries to inherit the event-group.
11423 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
11424 * inherited_all set when we 'fail' to inherit an orphaned event; this is
11425 * consistent with perf_event_release_kernel() removing all child events.
11432 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
11433 struct perf_event_context
*parent_ctx
,
11434 struct task_struct
*child
, int ctxn
,
11435 int *inherited_all
)
11438 struct perf_event_context
*child_ctx
;
11440 if (!event
->attr
.inherit
) {
11441 *inherited_all
= 0;
11445 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11448 * This is executed from the parent task context, so
11449 * inherit events that have been marked for cloning.
11450 * First allocate and initialize a context for the
11453 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
11457 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
11460 ret
= inherit_group(event
, parent
, parent_ctx
,
11464 *inherited_all
= 0;
11470 * Initialize the perf_event context in task_struct
11472 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
11474 struct perf_event_context
*child_ctx
, *parent_ctx
;
11475 struct perf_event_context
*cloned_ctx
;
11476 struct perf_event
*event
;
11477 struct task_struct
*parent
= current
;
11478 int inherited_all
= 1;
11479 unsigned long flags
;
11482 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
11486 * If the parent's context is a clone, pin it so it won't get
11487 * swapped under us.
11489 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
11494 * No need to check if parent_ctx != NULL here; since we saw
11495 * it non-NULL earlier, the only reason for it to become NULL
11496 * is if we exit, and since we're currently in the middle of
11497 * a fork we can't be exiting at the same time.
11501 * Lock the parent list. No need to lock the child - not PID
11502 * hashed yet and not running, so nobody can access it.
11504 mutex_lock(&parent_ctx
->mutex
);
11507 * We dont have to disable NMIs - we are only looking at
11508 * the list, not manipulating it:
11510 perf_event_groups_for_each(event
, &parent_ctx
->pinned_groups
) {
11511 ret
= inherit_task_group(event
, parent
, parent_ctx
,
11512 child
, ctxn
, &inherited_all
);
11518 * We can't hold ctx->lock when iterating the ->flexible_group list due
11519 * to allocations, but we need to prevent rotation because
11520 * rotate_ctx() will change the list from interrupt context.
11522 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11523 parent_ctx
->rotate_disable
= 1;
11524 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11526 perf_event_groups_for_each(event
, &parent_ctx
->flexible_groups
) {
11527 ret
= inherit_task_group(event
, parent
, parent_ctx
,
11528 child
, ctxn
, &inherited_all
);
11533 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11534 parent_ctx
->rotate_disable
= 0;
11536 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11538 if (child_ctx
&& inherited_all
) {
11540 * Mark the child context as a clone of the parent
11541 * context, or of whatever the parent is a clone of.
11543 * Note that if the parent is a clone, the holding of
11544 * parent_ctx->lock avoids it from being uncloned.
11546 cloned_ctx
= parent_ctx
->parent_ctx
;
11548 child_ctx
->parent_ctx
= cloned_ctx
;
11549 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
11551 child_ctx
->parent_ctx
= parent_ctx
;
11552 child_ctx
->parent_gen
= parent_ctx
->generation
;
11554 get_ctx(child_ctx
->parent_ctx
);
11557 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11559 mutex_unlock(&parent_ctx
->mutex
);
11561 perf_unpin_context(parent_ctx
);
11562 put_ctx(parent_ctx
);
11568 * Initialize the perf_event context in task_struct
11570 int perf_event_init_task(struct task_struct
*child
)
11574 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
11575 mutex_init(&child
->perf_event_mutex
);
11576 INIT_LIST_HEAD(&child
->perf_event_list
);
11578 for_each_task_context_nr(ctxn
) {
11579 ret
= perf_event_init_context(child
, ctxn
);
11581 perf_event_free_task(child
);
11589 static void __init
perf_event_init_all_cpus(void)
11591 struct swevent_htable
*swhash
;
11594 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
11596 for_each_possible_cpu(cpu
) {
11597 swhash
= &per_cpu(swevent_htable
, cpu
);
11598 mutex_init(&swhash
->hlist_mutex
);
11599 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11601 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11602 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11604 #ifdef CONFIG_CGROUP_PERF
11605 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11607 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11611 void perf_swevent_init_cpu(unsigned int cpu
)
11613 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11615 mutex_lock(&swhash
->hlist_mutex
);
11616 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11617 struct swevent_hlist
*hlist
;
11619 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11621 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11623 mutex_unlock(&swhash
->hlist_mutex
);
11626 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11627 static void __perf_event_exit_context(void *__info
)
11629 struct perf_event_context
*ctx
= __info
;
11630 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11631 struct perf_event
*event
;
11633 raw_spin_lock(&ctx
->lock
);
11634 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
11635 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11636 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11637 raw_spin_unlock(&ctx
->lock
);
11640 static void perf_event_exit_cpu_context(int cpu
)
11642 struct perf_cpu_context
*cpuctx
;
11643 struct perf_event_context
*ctx
;
11646 mutex_lock(&pmus_lock
);
11647 list_for_each_entry(pmu
, &pmus
, entry
) {
11648 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11649 ctx
= &cpuctx
->ctx
;
11651 mutex_lock(&ctx
->mutex
);
11652 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11653 cpuctx
->online
= 0;
11654 mutex_unlock(&ctx
->mutex
);
11656 cpumask_clear_cpu(cpu
, perf_online_mask
);
11657 mutex_unlock(&pmus_lock
);
11661 static void perf_event_exit_cpu_context(int cpu
) { }
11665 int perf_event_init_cpu(unsigned int cpu
)
11667 struct perf_cpu_context
*cpuctx
;
11668 struct perf_event_context
*ctx
;
11671 perf_swevent_init_cpu(cpu
);
11673 mutex_lock(&pmus_lock
);
11674 cpumask_set_cpu(cpu
, perf_online_mask
);
11675 list_for_each_entry(pmu
, &pmus
, entry
) {
11676 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11677 ctx
= &cpuctx
->ctx
;
11679 mutex_lock(&ctx
->mutex
);
11680 cpuctx
->online
= 1;
11681 mutex_unlock(&ctx
->mutex
);
11683 mutex_unlock(&pmus_lock
);
11688 int perf_event_exit_cpu(unsigned int cpu
)
11690 perf_event_exit_cpu_context(cpu
);
11695 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11699 for_each_online_cpu(cpu
)
11700 perf_event_exit_cpu(cpu
);
11706 * Run the perf reboot notifier at the very last possible moment so that
11707 * the generic watchdog code runs as long as possible.
11709 static struct notifier_block perf_reboot_notifier
= {
11710 .notifier_call
= perf_reboot
,
11711 .priority
= INT_MIN
,
11714 void __init
perf_event_init(void)
11718 idr_init(&pmu_idr
);
11720 perf_event_init_all_cpus();
11721 init_srcu_struct(&pmus_srcu
);
11722 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11723 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11724 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11725 perf_tp_register();
11726 perf_event_init_cpu(smp_processor_id());
11727 register_reboot_notifier(&perf_reboot_notifier
);
11729 ret
= init_hw_breakpoint();
11730 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11733 * Build time assertion that we keep the data_head at the intended
11734 * location. IOW, validation we got the __reserved[] size right.
11736 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11740 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11743 struct perf_pmu_events_attr
*pmu_attr
=
11744 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11746 if (pmu_attr
->event_str
)
11747 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11751 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11753 static int __init
perf_event_sysfs_init(void)
11758 mutex_lock(&pmus_lock
);
11760 ret
= bus_register(&pmu_bus
);
11764 list_for_each_entry(pmu
, &pmus
, entry
) {
11765 if (!pmu
->name
|| pmu
->type
< 0)
11768 ret
= pmu_dev_alloc(pmu
);
11769 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11771 pmu_bus_running
= 1;
11775 mutex_unlock(&pmus_lock
);
11779 device_initcall(perf_event_sysfs_init
);
11781 #ifdef CONFIG_CGROUP_PERF
11782 static struct cgroup_subsys_state
*
11783 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11785 struct perf_cgroup
*jc
;
11787 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11789 return ERR_PTR(-ENOMEM
);
11791 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11794 return ERR_PTR(-ENOMEM
);
11800 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11802 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11804 free_percpu(jc
->info
);
11808 static int __perf_cgroup_move(void *info
)
11810 struct task_struct
*task
= info
;
11812 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11817 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11819 struct task_struct
*task
;
11820 struct cgroup_subsys_state
*css
;
11822 cgroup_taskset_for_each(task
, css
, tset
)
11823 task_function_call(task
, __perf_cgroup_move
, task
);
11826 struct cgroup_subsys perf_event_cgrp_subsys
= {
11827 .css_alloc
= perf_cgroup_css_alloc
,
11828 .css_free
= perf_cgroup_css_free
,
11829 .attach
= perf_cgroup_attach
,
11831 * Implicitly enable on dfl hierarchy so that perf events can
11832 * always be filtered by cgroup2 path as long as perf_event
11833 * controller is not mounted on a legacy hierarchy.
11835 .implicit_on_dfl
= true,
11838 #endif /* CONFIG_CGROUP_PERF */