1 // SPDX-License-Identifier: GPL-2.0
3 * Performance events core code:
5 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
6 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
7 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
8 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <linux/idr.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/hash.h>
20 #include <linux/tick.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/rculist.h>
32 #include <linux/uaccess.h>
33 #include <linux/syscalls.h>
34 #include <linux/anon_inodes.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/cgroup.h>
37 #include <linux/perf_event.h>
38 #include <linux/trace_events.h>
39 #include <linux/hw_breakpoint.h>
40 #include <linux/mm_types.h>
41 #include <linux/module.h>
42 #include <linux/mman.h>
43 #include <linux/compat.h>
44 #include <linux/bpf.h>
45 #include <linux/filter.h>
46 #include <linux/namei.h>
47 #include <linux/parser.h>
48 #include <linux/sched/clock.h>
49 #include <linux/sched/mm.h>
50 #include <linux/proc_ns.h>
51 #include <linux/mount.h>
55 #include <asm/irq_regs.h>
57 typedef int (*remote_function_f
)(void *);
59 struct remote_function_call
{
60 struct task_struct
*p
;
61 remote_function_f func
;
66 static void remote_function(void *data
)
68 struct remote_function_call
*tfc
= data
;
69 struct task_struct
*p
= tfc
->p
;
73 if (task_cpu(p
) != smp_processor_id())
77 * Now that we're on right CPU with IRQs disabled, we can test
78 * if we hit the right task without races.
81 tfc
->ret
= -ESRCH
; /* No such (running) process */
86 tfc
->ret
= tfc
->func(tfc
->info
);
90 * task_function_call - call a function on the cpu on which a task runs
91 * @p: the task to evaluate
92 * @func: the function to be called
93 * @info: the function call argument
95 * Calls the function @func when the task is currently running. This might
96 * be on the current CPU, which just calls the function directly
98 * returns: @func return value, or
99 * -ESRCH - when the process isn't running
100 * -EAGAIN - when the process moved away
103 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
105 struct remote_function_call data
= {
114 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
117 } while (ret
== -EAGAIN
);
123 * cpu_function_call - call a function on the cpu
124 * @func: the function to be called
125 * @info: the function call argument
127 * Calls the function @func on the remote cpu.
129 * returns: @func return value or -ENXIO when the cpu is offline
131 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
133 struct remote_function_call data
= {
137 .ret
= -ENXIO
, /* No such CPU */
140 smp_call_function_single(cpu
, remote_function
, &data
, 1);
145 static inline struct perf_cpu_context
*
146 __get_cpu_context(struct perf_event_context
*ctx
)
148 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
151 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
152 struct perf_event_context
*ctx
)
154 raw_spin_lock(&cpuctx
->ctx
.lock
);
156 raw_spin_lock(&ctx
->lock
);
159 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
160 struct perf_event_context
*ctx
)
163 raw_spin_unlock(&ctx
->lock
);
164 raw_spin_unlock(&cpuctx
->ctx
.lock
);
167 #define TASK_TOMBSTONE ((void *)-1L)
169 static bool is_kernel_event(struct perf_event
*event
)
171 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
175 * On task ctx scheduling...
177 * When !ctx->nr_events a task context will not be scheduled. This means
178 * we can disable the scheduler hooks (for performance) without leaving
179 * pending task ctx state.
181 * This however results in two special cases:
183 * - removing the last event from a task ctx; this is relatively straight
184 * forward and is done in __perf_remove_from_context.
186 * - adding the first event to a task ctx; this is tricky because we cannot
187 * rely on ctx->is_active and therefore cannot use event_function_call().
188 * See perf_install_in_context().
190 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
193 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
194 struct perf_event_context
*, void *);
196 struct event_function_struct
{
197 struct perf_event
*event
;
202 static int event_function(void *info
)
204 struct event_function_struct
*efs
= info
;
205 struct perf_event
*event
= efs
->event
;
206 struct perf_event_context
*ctx
= event
->ctx
;
207 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
208 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
211 lockdep_assert_irqs_disabled();
213 perf_ctx_lock(cpuctx
, task_ctx
);
215 * Since we do the IPI call without holding ctx->lock things can have
216 * changed, double check we hit the task we set out to hit.
219 if (ctx
->task
!= current
) {
225 * We only use event_function_call() on established contexts,
226 * and event_function() is only ever called when active (or
227 * rather, we'll have bailed in task_function_call() or the
228 * above ctx->task != current test), therefore we must have
229 * ctx->is_active here.
231 WARN_ON_ONCE(!ctx
->is_active
);
233 * And since we have ctx->is_active, cpuctx->task_ctx must
236 WARN_ON_ONCE(task_ctx
!= ctx
);
238 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
241 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
243 perf_ctx_unlock(cpuctx
, task_ctx
);
248 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
250 struct perf_event_context
*ctx
= event
->ctx
;
251 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
252 struct event_function_struct efs
= {
258 if (!event
->parent
) {
260 * If this is a !child event, we must hold ctx::mutex to
261 * stabilize the the event->ctx relation. See
262 * perf_event_ctx_lock().
264 lockdep_assert_held(&ctx
->mutex
);
268 cpu_function_call(event
->cpu
, event_function
, &efs
);
272 if (task
== TASK_TOMBSTONE
)
276 if (!task_function_call(task
, event_function
, &efs
))
279 raw_spin_lock_irq(&ctx
->lock
);
281 * Reload the task pointer, it might have been changed by
282 * a concurrent perf_event_context_sched_out().
285 if (task
== TASK_TOMBSTONE
) {
286 raw_spin_unlock_irq(&ctx
->lock
);
289 if (ctx
->is_active
) {
290 raw_spin_unlock_irq(&ctx
->lock
);
293 func(event
, NULL
, ctx
, data
);
294 raw_spin_unlock_irq(&ctx
->lock
);
298 * Similar to event_function_call() + event_function(), but hard assumes IRQs
299 * are already disabled and we're on the right CPU.
301 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
303 struct perf_event_context
*ctx
= event
->ctx
;
304 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
305 struct task_struct
*task
= READ_ONCE(ctx
->task
);
306 struct perf_event_context
*task_ctx
= NULL
;
308 lockdep_assert_irqs_disabled();
311 if (task
== TASK_TOMBSTONE
)
317 perf_ctx_lock(cpuctx
, task_ctx
);
320 if (task
== TASK_TOMBSTONE
)
325 * We must be either inactive or active and the right task,
326 * otherwise we're screwed, since we cannot IPI to somewhere
329 if (ctx
->is_active
) {
330 if (WARN_ON_ONCE(task
!= current
))
333 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
337 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
340 func(event
, cpuctx
, ctx
, data
);
342 perf_ctx_unlock(cpuctx
, task_ctx
);
345 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
346 PERF_FLAG_FD_OUTPUT |\
347 PERF_FLAG_PID_CGROUP |\
348 PERF_FLAG_FD_CLOEXEC)
351 * branch priv levels that need permission checks
353 #define PERF_SAMPLE_BRANCH_PERM_PLM \
354 (PERF_SAMPLE_BRANCH_KERNEL |\
355 PERF_SAMPLE_BRANCH_HV)
358 EVENT_FLEXIBLE
= 0x1,
361 /* see ctx_resched() for details */
363 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
367 * perf_sched_events : >0 events exist
368 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
371 static void perf_sched_delayed(struct work_struct
*work
);
372 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
373 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
374 static DEFINE_MUTEX(perf_sched_mutex
);
375 static atomic_t perf_sched_count
;
377 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
378 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
379 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
381 static atomic_t nr_mmap_events __read_mostly
;
382 static atomic_t nr_comm_events __read_mostly
;
383 static atomic_t nr_namespaces_events __read_mostly
;
384 static atomic_t nr_task_events __read_mostly
;
385 static atomic_t nr_freq_events __read_mostly
;
386 static atomic_t nr_switch_events __read_mostly
;
387 static atomic_t nr_ksymbol_events __read_mostly
;
388 static atomic_t nr_bpf_events __read_mostly
;
390 static LIST_HEAD(pmus
);
391 static DEFINE_MUTEX(pmus_lock
);
392 static struct srcu_struct pmus_srcu
;
393 static cpumask_var_t perf_online_mask
;
396 * perf event paranoia level:
397 * -1 - not paranoid at all
398 * 0 - disallow raw tracepoint access for unpriv
399 * 1 - disallow cpu events for unpriv
400 * 2 - disallow kernel profiling for unpriv
402 int sysctl_perf_event_paranoid __read_mostly
= 2;
404 /* Minimum for 512 kiB + 1 user control page */
405 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
408 * max perf event sample rate
410 #define DEFAULT_MAX_SAMPLE_RATE 100000
411 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
412 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
414 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
416 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
417 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
419 static int perf_sample_allowed_ns __read_mostly
=
420 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
422 static void update_perf_cpu_limits(void)
424 u64 tmp
= perf_sample_period_ns
;
426 tmp
*= sysctl_perf_cpu_time_max_percent
;
427 tmp
= div_u64(tmp
, 100);
431 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
434 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
);
436 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
437 void __user
*buffer
, size_t *lenp
,
441 int perf_cpu
= sysctl_perf_cpu_time_max_percent
;
443 * If throttling is disabled don't allow the write:
445 if (write
&& (perf_cpu
== 100 || perf_cpu
== 0))
448 ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
452 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
453 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
454 update_perf_cpu_limits();
459 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
461 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
462 void __user
*buffer
, size_t *lenp
,
465 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
470 if (sysctl_perf_cpu_time_max_percent
== 100 ||
471 sysctl_perf_cpu_time_max_percent
== 0) {
473 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
474 WRITE_ONCE(perf_sample_allowed_ns
, 0);
476 update_perf_cpu_limits();
483 * perf samples are done in some very critical code paths (NMIs).
484 * If they take too much CPU time, the system can lock up and not
485 * get any real work done. This will drop the sample rate when
486 * we detect that events are taking too long.
488 #define NR_ACCUMULATED_SAMPLES 128
489 static DEFINE_PER_CPU(u64
, running_sample_length
);
491 static u64 __report_avg
;
492 static u64 __report_allowed
;
494 static void perf_duration_warn(struct irq_work
*w
)
496 printk_ratelimited(KERN_INFO
497 "perf: interrupt took too long (%lld > %lld), lowering "
498 "kernel.perf_event_max_sample_rate to %d\n",
499 __report_avg
, __report_allowed
,
500 sysctl_perf_event_sample_rate
);
503 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
505 void perf_sample_event_took(u64 sample_len_ns
)
507 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
515 /* Decay the counter by 1 average sample. */
516 running_len
= __this_cpu_read(running_sample_length
);
517 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
518 running_len
+= sample_len_ns
;
519 __this_cpu_write(running_sample_length
, running_len
);
522 * Note: this will be biased artifically low until we have
523 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
524 * from having to maintain a count.
526 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
527 if (avg_len
<= max_len
)
530 __report_avg
= avg_len
;
531 __report_allowed
= max_len
;
534 * Compute a throttle threshold 25% below the current duration.
536 avg_len
+= avg_len
/ 4;
537 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
543 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
544 WRITE_ONCE(max_samples_per_tick
, max
);
546 sysctl_perf_event_sample_rate
= max
* HZ
;
547 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
549 if (!irq_work_queue(&perf_duration_work
)) {
550 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
551 "kernel.perf_event_max_sample_rate to %d\n",
552 __report_avg
, __report_allowed
,
553 sysctl_perf_event_sample_rate
);
557 static atomic64_t perf_event_id
;
559 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
560 enum event_type_t event_type
);
562 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
563 enum event_type_t event_type
,
564 struct task_struct
*task
);
566 static void update_context_time(struct perf_event_context
*ctx
);
567 static u64
perf_event_time(struct perf_event
*event
);
569 void __weak
perf_event_print_debug(void) { }
571 extern __weak
const char *perf_pmu_name(void)
576 static inline u64
perf_clock(void)
578 return local_clock();
581 static inline u64
perf_event_clock(struct perf_event
*event
)
583 return event
->clock();
587 * State based event timekeeping...
589 * The basic idea is to use event->state to determine which (if any) time
590 * fields to increment with the current delta. This means we only need to
591 * update timestamps when we change state or when they are explicitly requested
594 * Event groups make things a little more complicated, but not terribly so. The
595 * rules for a group are that if the group leader is OFF the entire group is
596 * OFF, irrespecive of what the group member states are. This results in
597 * __perf_effective_state().
599 * A futher ramification is that when a group leader flips between OFF and
600 * !OFF, we need to update all group member times.
603 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
604 * need to make sure the relevant context time is updated before we try and
605 * update our timestamps.
608 static __always_inline
enum perf_event_state
609 __perf_effective_state(struct perf_event
*event
)
611 struct perf_event
*leader
= event
->group_leader
;
613 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
614 return leader
->state
;
619 static __always_inline
void
620 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
622 enum perf_event_state state
= __perf_effective_state(event
);
623 u64 delta
= now
- event
->tstamp
;
625 *enabled
= event
->total_time_enabled
;
626 if (state
>= PERF_EVENT_STATE_INACTIVE
)
629 *running
= event
->total_time_running
;
630 if (state
>= PERF_EVENT_STATE_ACTIVE
)
634 static void perf_event_update_time(struct perf_event
*event
)
636 u64 now
= perf_event_time(event
);
638 __perf_update_times(event
, now
, &event
->total_time_enabled
,
639 &event
->total_time_running
);
643 static void perf_event_update_sibling_time(struct perf_event
*leader
)
645 struct perf_event
*sibling
;
647 for_each_sibling_event(sibling
, leader
)
648 perf_event_update_time(sibling
);
652 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
654 if (event
->state
== state
)
657 perf_event_update_time(event
);
659 * If a group leader gets enabled/disabled all its siblings
662 if ((event
->state
< 0) ^ (state
< 0))
663 perf_event_update_sibling_time(event
);
665 WRITE_ONCE(event
->state
, state
);
668 #ifdef CONFIG_CGROUP_PERF
671 perf_cgroup_match(struct perf_event
*event
)
673 struct perf_event_context
*ctx
= event
->ctx
;
674 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
676 /* @event doesn't care about cgroup */
680 /* wants specific cgroup scope but @cpuctx isn't associated with any */
685 * Cgroup scoping is recursive. An event enabled for a cgroup is
686 * also enabled for all its descendant cgroups. If @cpuctx's
687 * cgroup is a descendant of @event's (the test covers identity
688 * case), it's a match.
690 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
691 event
->cgrp
->css
.cgroup
);
694 static inline void perf_detach_cgroup(struct perf_event
*event
)
696 css_put(&event
->cgrp
->css
);
700 static inline int is_cgroup_event(struct perf_event
*event
)
702 return event
->cgrp
!= NULL
;
705 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
707 struct perf_cgroup_info
*t
;
709 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
713 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
715 struct perf_cgroup_info
*info
;
720 info
= this_cpu_ptr(cgrp
->info
);
722 info
->time
+= now
- info
->timestamp
;
723 info
->timestamp
= now
;
726 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
728 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
729 struct cgroup_subsys_state
*css
;
732 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
733 cgrp
= container_of(css
, struct perf_cgroup
, css
);
734 __update_cgrp_time(cgrp
);
739 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
741 struct perf_cgroup
*cgrp
;
744 * ensure we access cgroup data only when needed and
745 * when we know the cgroup is pinned (css_get)
747 if (!is_cgroup_event(event
))
750 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
752 * Do not update time when cgroup is not active
754 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
755 __update_cgrp_time(event
->cgrp
);
759 perf_cgroup_set_timestamp(struct task_struct
*task
,
760 struct perf_event_context
*ctx
)
762 struct perf_cgroup
*cgrp
;
763 struct perf_cgroup_info
*info
;
764 struct cgroup_subsys_state
*css
;
767 * ctx->lock held by caller
768 * ensure we do not access cgroup data
769 * unless we have the cgroup pinned (css_get)
771 if (!task
|| !ctx
->nr_cgroups
)
774 cgrp
= perf_cgroup_from_task(task
, ctx
);
776 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
777 cgrp
= container_of(css
, struct perf_cgroup
, css
);
778 info
= this_cpu_ptr(cgrp
->info
);
779 info
->timestamp
= ctx
->timestamp
;
783 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
785 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
786 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
789 * reschedule events based on the cgroup constraint of task.
791 * mode SWOUT : schedule out everything
792 * mode SWIN : schedule in based on cgroup for next
794 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
796 struct perf_cpu_context
*cpuctx
;
797 struct list_head
*list
;
801 * Disable interrupts and preemption to avoid this CPU's
802 * cgrp_cpuctx_entry to change under us.
804 local_irq_save(flags
);
806 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
807 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
808 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
810 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
811 perf_pmu_disable(cpuctx
->ctx
.pmu
);
813 if (mode
& PERF_CGROUP_SWOUT
) {
814 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
816 * must not be done before ctxswout due
817 * to event_filter_match() in event_sched_out()
822 if (mode
& PERF_CGROUP_SWIN
) {
823 WARN_ON_ONCE(cpuctx
->cgrp
);
825 * set cgrp before ctxsw in to allow
826 * event_filter_match() to not have to pass
828 * we pass the cpuctx->ctx to perf_cgroup_from_task()
829 * because cgorup events are only per-cpu
831 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
833 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
835 perf_pmu_enable(cpuctx
->ctx
.pmu
);
836 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
839 local_irq_restore(flags
);
842 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
843 struct task_struct
*next
)
845 struct perf_cgroup
*cgrp1
;
846 struct perf_cgroup
*cgrp2
= NULL
;
850 * we come here when we know perf_cgroup_events > 0
851 * we do not need to pass the ctx here because we know
852 * we are holding the rcu lock
854 cgrp1
= perf_cgroup_from_task(task
, NULL
);
855 cgrp2
= perf_cgroup_from_task(next
, NULL
);
858 * only schedule out current cgroup events if we know
859 * that we are switching to a different cgroup. Otherwise,
860 * do no touch the cgroup events.
863 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
868 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
869 struct task_struct
*task
)
871 struct perf_cgroup
*cgrp1
;
872 struct perf_cgroup
*cgrp2
= NULL
;
876 * we come here when we know perf_cgroup_events > 0
877 * we do not need to pass the ctx here because we know
878 * we are holding the rcu lock
880 cgrp1
= perf_cgroup_from_task(task
, NULL
);
881 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
884 * only need to schedule in cgroup events if we are changing
885 * cgroup during ctxsw. Cgroup events were not scheduled
886 * out of ctxsw out if that was not the case.
889 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
894 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
895 struct perf_event_attr
*attr
,
896 struct perf_event
*group_leader
)
898 struct perf_cgroup
*cgrp
;
899 struct cgroup_subsys_state
*css
;
900 struct fd f
= fdget(fd
);
906 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
907 &perf_event_cgrp_subsys
);
913 cgrp
= container_of(css
, struct perf_cgroup
, css
);
917 * all events in a group must monitor
918 * the same cgroup because a task belongs
919 * to only one perf cgroup at a time
921 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
922 perf_detach_cgroup(event
);
931 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
933 struct perf_cgroup_info
*t
;
934 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
935 event
->shadow_ctx_time
= now
- t
->timestamp
;
939 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
940 * cleared when last cgroup event is removed.
943 list_update_cgroup_event(struct perf_event
*event
,
944 struct perf_event_context
*ctx
, bool add
)
946 struct perf_cpu_context
*cpuctx
;
947 struct list_head
*cpuctx_entry
;
949 if (!is_cgroup_event(event
))
953 * Because cgroup events are always per-cpu events,
954 * @ctx == &cpuctx->ctx.
956 cpuctx
= container_of(ctx
, struct perf_cpu_context
, ctx
);
959 * Since setting cpuctx->cgrp is conditional on the current @cgrp
960 * matching the event's cgroup, we must do this for every new event,
961 * because if the first would mismatch, the second would not try again
962 * and we would leave cpuctx->cgrp unset.
964 if (add
&& !cpuctx
->cgrp
) {
965 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
967 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
971 if (add
&& ctx
->nr_cgroups
++)
973 else if (!add
&& --ctx
->nr_cgroups
)
976 /* no cgroup running */
980 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
982 list_add(cpuctx_entry
,
983 per_cpu_ptr(&cgrp_cpuctx_list
, event
->cpu
));
985 list_del(cpuctx_entry
);
988 #else /* !CONFIG_CGROUP_PERF */
991 perf_cgroup_match(struct perf_event
*event
)
996 static inline void perf_detach_cgroup(struct perf_event
*event
)
999 static inline int is_cgroup_event(struct perf_event
*event
)
1004 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1008 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1012 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1013 struct task_struct
*next
)
1017 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1018 struct task_struct
*task
)
1022 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1023 struct perf_event_attr
*attr
,
1024 struct perf_event
*group_leader
)
1030 perf_cgroup_set_timestamp(struct task_struct
*task
,
1031 struct perf_event_context
*ctx
)
1036 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1041 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1045 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1051 list_update_cgroup_event(struct perf_event
*event
,
1052 struct perf_event_context
*ctx
, bool add
)
1059 * set default to be dependent on timer tick just
1060 * like original code
1062 #define PERF_CPU_HRTIMER (1000 / HZ)
1064 * function must be called with interrupts disabled
1066 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1068 struct perf_cpu_context
*cpuctx
;
1071 lockdep_assert_irqs_disabled();
1073 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1074 rotations
= perf_rotate_context(cpuctx
);
1076 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1078 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1080 cpuctx
->hrtimer_active
= 0;
1081 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1083 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1086 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1088 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1089 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1092 /* no multiplexing needed for SW PMU */
1093 if (pmu
->task_ctx_nr
== perf_sw_context
)
1097 * check default is sane, if not set then force to
1098 * default interval (1/tick)
1100 interval
= pmu
->hrtimer_interval_ms
;
1102 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1104 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1106 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1107 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED_HARD
);
1108 timer
->function
= perf_mux_hrtimer_handler
;
1111 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1113 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1114 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1115 unsigned long flags
;
1117 /* not for SW PMU */
1118 if (pmu
->task_ctx_nr
== perf_sw_context
)
1121 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1122 if (!cpuctx
->hrtimer_active
) {
1123 cpuctx
->hrtimer_active
= 1;
1124 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1125 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED_HARD
);
1127 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1132 void perf_pmu_disable(struct pmu
*pmu
)
1134 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1136 pmu
->pmu_disable(pmu
);
1139 void perf_pmu_enable(struct pmu
*pmu
)
1141 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1143 pmu
->pmu_enable(pmu
);
1146 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1149 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1150 * perf_event_task_tick() are fully serialized because they're strictly cpu
1151 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1152 * disabled, while perf_event_task_tick is called from IRQ context.
1154 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1156 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1158 lockdep_assert_irqs_disabled();
1160 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1162 list_add(&ctx
->active_ctx_list
, head
);
1165 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1167 lockdep_assert_irqs_disabled();
1169 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1171 list_del_init(&ctx
->active_ctx_list
);
1174 static void get_ctx(struct perf_event_context
*ctx
)
1176 refcount_inc(&ctx
->refcount
);
1179 static void free_ctx(struct rcu_head
*head
)
1181 struct perf_event_context
*ctx
;
1183 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1184 kfree(ctx
->task_ctx_data
);
1188 static void put_ctx(struct perf_event_context
*ctx
)
1190 if (refcount_dec_and_test(&ctx
->refcount
)) {
1191 if (ctx
->parent_ctx
)
1192 put_ctx(ctx
->parent_ctx
);
1193 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1194 put_task_struct(ctx
->task
);
1195 call_rcu(&ctx
->rcu_head
, free_ctx
);
1200 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1201 * perf_pmu_migrate_context() we need some magic.
1203 * Those places that change perf_event::ctx will hold both
1204 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1206 * Lock ordering is by mutex address. There are two other sites where
1207 * perf_event_context::mutex nests and those are:
1209 * - perf_event_exit_task_context() [ child , 0 ]
1210 * perf_event_exit_event()
1211 * put_event() [ parent, 1 ]
1213 * - perf_event_init_context() [ parent, 0 ]
1214 * inherit_task_group()
1217 * perf_event_alloc()
1219 * perf_try_init_event() [ child , 1 ]
1221 * While it appears there is an obvious deadlock here -- the parent and child
1222 * nesting levels are inverted between the two. This is in fact safe because
1223 * life-time rules separate them. That is an exiting task cannot fork, and a
1224 * spawning task cannot (yet) exit.
1226 * But remember that that these are parent<->child context relations, and
1227 * migration does not affect children, therefore these two orderings should not
1230 * The change in perf_event::ctx does not affect children (as claimed above)
1231 * because the sys_perf_event_open() case will install a new event and break
1232 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1233 * concerned with cpuctx and that doesn't have children.
1235 * The places that change perf_event::ctx will issue:
1237 * perf_remove_from_context();
1238 * synchronize_rcu();
1239 * perf_install_in_context();
1241 * to affect the change. The remove_from_context() + synchronize_rcu() should
1242 * quiesce the event, after which we can install it in the new location. This
1243 * means that only external vectors (perf_fops, prctl) can perturb the event
1244 * while in transit. Therefore all such accessors should also acquire
1245 * perf_event_context::mutex to serialize against this.
1247 * However; because event->ctx can change while we're waiting to acquire
1248 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1253 * task_struct::perf_event_mutex
1254 * perf_event_context::mutex
1255 * perf_event::child_mutex;
1256 * perf_event_context::lock
1257 * perf_event::mmap_mutex
1259 * perf_addr_filters_head::lock
1263 * cpuctx->mutex / perf_event_context::mutex
1265 static struct perf_event_context
*
1266 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1268 struct perf_event_context
*ctx
;
1272 ctx
= READ_ONCE(event
->ctx
);
1273 if (!refcount_inc_not_zero(&ctx
->refcount
)) {
1279 mutex_lock_nested(&ctx
->mutex
, nesting
);
1280 if (event
->ctx
!= ctx
) {
1281 mutex_unlock(&ctx
->mutex
);
1289 static inline struct perf_event_context
*
1290 perf_event_ctx_lock(struct perf_event
*event
)
1292 return perf_event_ctx_lock_nested(event
, 0);
1295 static void perf_event_ctx_unlock(struct perf_event
*event
,
1296 struct perf_event_context
*ctx
)
1298 mutex_unlock(&ctx
->mutex
);
1303 * This must be done under the ctx->lock, such as to serialize against
1304 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1305 * calling scheduler related locks and ctx->lock nests inside those.
1307 static __must_check
struct perf_event_context
*
1308 unclone_ctx(struct perf_event_context
*ctx
)
1310 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1312 lockdep_assert_held(&ctx
->lock
);
1315 ctx
->parent_ctx
= NULL
;
1321 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1326 * only top level events have the pid namespace they were created in
1329 event
= event
->parent
;
1331 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1332 /* avoid -1 if it is idle thread or runs in another ns */
1333 if (!nr
&& !pid_alive(p
))
1338 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1340 return perf_event_pid_type(event
, p
, PIDTYPE_TGID
);
1343 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1345 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1349 * If we inherit events we want to return the parent event id
1352 static u64
primary_event_id(struct perf_event
*event
)
1357 id
= event
->parent
->id
;
1363 * Get the perf_event_context for a task and lock it.
1365 * This has to cope with with the fact that until it is locked,
1366 * the context could get moved to another task.
1368 static struct perf_event_context
*
1369 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1371 struct perf_event_context
*ctx
;
1375 * One of the few rules of preemptible RCU is that one cannot do
1376 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1377 * part of the read side critical section was irqs-enabled -- see
1378 * rcu_read_unlock_special().
1380 * Since ctx->lock nests under rq->lock we must ensure the entire read
1381 * side critical section has interrupts disabled.
1383 local_irq_save(*flags
);
1385 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1388 * If this context is a clone of another, it might
1389 * get swapped for another underneath us by
1390 * perf_event_task_sched_out, though the
1391 * rcu_read_lock() protects us from any context
1392 * getting freed. Lock the context and check if it
1393 * got swapped before we could get the lock, and retry
1394 * if so. If we locked the right context, then it
1395 * can't get swapped on us any more.
1397 raw_spin_lock(&ctx
->lock
);
1398 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1399 raw_spin_unlock(&ctx
->lock
);
1401 local_irq_restore(*flags
);
1405 if (ctx
->task
== TASK_TOMBSTONE
||
1406 !refcount_inc_not_zero(&ctx
->refcount
)) {
1407 raw_spin_unlock(&ctx
->lock
);
1410 WARN_ON_ONCE(ctx
->task
!= task
);
1415 local_irq_restore(*flags
);
1420 * Get the context for a task and increment its pin_count so it
1421 * can't get swapped to another task. This also increments its
1422 * reference count so that the context can't get freed.
1424 static struct perf_event_context
*
1425 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1427 struct perf_event_context
*ctx
;
1428 unsigned long flags
;
1430 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1433 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1438 static void perf_unpin_context(struct perf_event_context
*ctx
)
1440 unsigned long flags
;
1442 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1444 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1448 * Update the record of the current time in a context.
1450 static void update_context_time(struct perf_event_context
*ctx
)
1452 u64 now
= perf_clock();
1454 ctx
->time
+= now
- ctx
->timestamp
;
1455 ctx
->timestamp
= now
;
1458 static u64
perf_event_time(struct perf_event
*event
)
1460 struct perf_event_context
*ctx
= event
->ctx
;
1462 if (is_cgroup_event(event
))
1463 return perf_cgroup_event_time(event
);
1465 return ctx
? ctx
->time
: 0;
1468 static enum event_type_t
get_event_type(struct perf_event
*event
)
1470 struct perf_event_context
*ctx
= event
->ctx
;
1471 enum event_type_t event_type
;
1473 lockdep_assert_held(&ctx
->lock
);
1476 * It's 'group type', really, because if our group leader is
1477 * pinned, so are we.
1479 if (event
->group_leader
!= event
)
1480 event
= event
->group_leader
;
1482 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1484 event_type
|= EVENT_CPU
;
1490 * Helper function to initialize event group nodes.
1492 static void init_event_group(struct perf_event
*event
)
1494 RB_CLEAR_NODE(&event
->group_node
);
1495 event
->group_index
= 0;
1499 * Extract pinned or flexible groups from the context
1500 * based on event attrs bits.
1502 static struct perf_event_groups
*
1503 get_event_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1505 if (event
->attr
.pinned
)
1506 return &ctx
->pinned_groups
;
1508 return &ctx
->flexible_groups
;
1512 * Helper function to initializes perf_event_group trees.
1514 static void perf_event_groups_init(struct perf_event_groups
*groups
)
1516 groups
->tree
= RB_ROOT
;
1521 * Compare function for event groups;
1523 * Implements complex key that first sorts by CPU and then by virtual index
1524 * which provides ordering when rotating groups for the same CPU.
1527 perf_event_groups_less(struct perf_event
*left
, struct perf_event
*right
)
1529 if (left
->cpu
< right
->cpu
)
1531 if (left
->cpu
> right
->cpu
)
1534 if (left
->group_index
< right
->group_index
)
1536 if (left
->group_index
> right
->group_index
)
1543 * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
1544 * key (see perf_event_groups_less). This places it last inside the CPU
1548 perf_event_groups_insert(struct perf_event_groups
*groups
,
1549 struct perf_event
*event
)
1551 struct perf_event
*node_event
;
1552 struct rb_node
*parent
;
1553 struct rb_node
**node
;
1555 event
->group_index
= ++groups
->index
;
1557 node
= &groups
->tree
.rb_node
;
1562 node_event
= container_of(*node
, struct perf_event
, group_node
);
1564 if (perf_event_groups_less(event
, node_event
))
1565 node
= &parent
->rb_left
;
1567 node
= &parent
->rb_right
;
1570 rb_link_node(&event
->group_node
, parent
, node
);
1571 rb_insert_color(&event
->group_node
, &groups
->tree
);
1575 * Helper function to insert event into the pinned or flexible groups.
1578 add_event_to_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1580 struct perf_event_groups
*groups
;
1582 groups
= get_event_groups(event
, ctx
);
1583 perf_event_groups_insert(groups
, event
);
1587 * Delete a group from a tree.
1590 perf_event_groups_delete(struct perf_event_groups
*groups
,
1591 struct perf_event
*event
)
1593 WARN_ON_ONCE(RB_EMPTY_NODE(&event
->group_node
) ||
1594 RB_EMPTY_ROOT(&groups
->tree
));
1596 rb_erase(&event
->group_node
, &groups
->tree
);
1597 init_event_group(event
);
1601 * Helper function to delete event from its groups.
1604 del_event_from_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1606 struct perf_event_groups
*groups
;
1608 groups
= get_event_groups(event
, ctx
);
1609 perf_event_groups_delete(groups
, event
);
1613 * Get the leftmost event in the @cpu subtree.
1615 static struct perf_event
*
1616 perf_event_groups_first(struct perf_event_groups
*groups
, int cpu
)
1618 struct perf_event
*node_event
= NULL
, *match
= NULL
;
1619 struct rb_node
*node
= groups
->tree
.rb_node
;
1622 node_event
= container_of(node
, struct perf_event
, group_node
);
1624 if (cpu
< node_event
->cpu
) {
1625 node
= node
->rb_left
;
1626 } else if (cpu
> node_event
->cpu
) {
1627 node
= node
->rb_right
;
1630 node
= node
->rb_left
;
1638 * Like rb_entry_next_safe() for the @cpu subtree.
1640 static struct perf_event
*
1641 perf_event_groups_next(struct perf_event
*event
)
1643 struct perf_event
*next
;
1645 next
= rb_entry_safe(rb_next(&event
->group_node
), typeof(*event
), group_node
);
1646 if (next
&& next
->cpu
== event
->cpu
)
1653 * Iterate through the whole groups tree.
1655 #define perf_event_groups_for_each(event, groups) \
1656 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1657 typeof(*event), group_node); event; \
1658 event = rb_entry_safe(rb_next(&event->group_node), \
1659 typeof(*event), group_node))
1662 * Add an event from the lists for its context.
1663 * Must be called with ctx->mutex and ctx->lock held.
1666 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1668 lockdep_assert_held(&ctx
->lock
);
1670 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1671 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1673 event
->tstamp
= perf_event_time(event
);
1676 * If we're a stand alone event or group leader, we go to the context
1677 * list, group events are kept attached to the group so that
1678 * perf_group_detach can, at all times, locate all siblings.
1680 if (event
->group_leader
== event
) {
1681 event
->group_caps
= event
->event_caps
;
1682 add_event_to_groups(event
, ctx
);
1685 list_update_cgroup_event(event
, ctx
, true);
1687 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1689 if (event
->attr
.inherit_stat
)
1696 * Initialize event state based on the perf_event_attr::disabled.
1698 static inline void perf_event__state_init(struct perf_event
*event
)
1700 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1701 PERF_EVENT_STATE_INACTIVE
;
1704 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1706 int entry
= sizeof(u64
); /* value */
1710 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1711 size
+= sizeof(u64
);
1713 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1714 size
+= sizeof(u64
);
1716 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1717 entry
+= sizeof(u64
);
1719 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1721 size
+= sizeof(u64
);
1725 event
->read_size
= size
;
1728 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1730 struct perf_sample_data
*data
;
1733 if (sample_type
& PERF_SAMPLE_IP
)
1734 size
+= sizeof(data
->ip
);
1736 if (sample_type
& PERF_SAMPLE_ADDR
)
1737 size
+= sizeof(data
->addr
);
1739 if (sample_type
& PERF_SAMPLE_PERIOD
)
1740 size
+= sizeof(data
->period
);
1742 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1743 size
+= sizeof(data
->weight
);
1745 if (sample_type
& PERF_SAMPLE_READ
)
1746 size
+= event
->read_size
;
1748 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1749 size
+= sizeof(data
->data_src
.val
);
1751 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1752 size
+= sizeof(data
->txn
);
1754 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1755 size
+= sizeof(data
->phys_addr
);
1757 event
->header_size
= size
;
1761 * Called at perf_event creation and when events are attached/detached from a
1764 static void perf_event__header_size(struct perf_event
*event
)
1766 __perf_event_read_size(event
,
1767 event
->group_leader
->nr_siblings
);
1768 __perf_event_header_size(event
, event
->attr
.sample_type
);
1771 static void perf_event__id_header_size(struct perf_event
*event
)
1773 struct perf_sample_data
*data
;
1774 u64 sample_type
= event
->attr
.sample_type
;
1777 if (sample_type
& PERF_SAMPLE_TID
)
1778 size
+= sizeof(data
->tid_entry
);
1780 if (sample_type
& PERF_SAMPLE_TIME
)
1781 size
+= sizeof(data
->time
);
1783 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1784 size
+= sizeof(data
->id
);
1786 if (sample_type
& PERF_SAMPLE_ID
)
1787 size
+= sizeof(data
->id
);
1789 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1790 size
+= sizeof(data
->stream_id
);
1792 if (sample_type
& PERF_SAMPLE_CPU
)
1793 size
+= sizeof(data
->cpu_entry
);
1795 event
->id_header_size
= size
;
1798 static bool perf_event_validate_size(struct perf_event
*event
)
1801 * The values computed here will be over-written when we actually
1804 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1805 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1806 perf_event__id_header_size(event
);
1809 * Sum the lot; should not exceed the 64k limit we have on records.
1810 * Conservative limit to allow for callchains and other variable fields.
1812 if (event
->read_size
+ event
->header_size
+
1813 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1819 static void perf_group_attach(struct perf_event
*event
)
1821 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1823 lockdep_assert_held(&event
->ctx
->lock
);
1826 * We can have double attach due to group movement in perf_event_open.
1828 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1831 event
->attach_state
|= PERF_ATTACH_GROUP
;
1833 if (group_leader
== event
)
1836 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1838 group_leader
->group_caps
&= event
->event_caps
;
1840 list_add_tail(&event
->sibling_list
, &group_leader
->sibling_list
);
1841 group_leader
->nr_siblings
++;
1843 perf_event__header_size(group_leader
);
1845 for_each_sibling_event(pos
, group_leader
)
1846 perf_event__header_size(pos
);
1850 * Remove an event from the lists for its context.
1851 * Must be called with ctx->mutex and ctx->lock held.
1854 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1856 WARN_ON_ONCE(event
->ctx
!= ctx
);
1857 lockdep_assert_held(&ctx
->lock
);
1860 * We can have double detach due to exit/hot-unplug + close.
1862 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1865 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1867 list_update_cgroup_event(event
, ctx
, false);
1870 if (event
->attr
.inherit_stat
)
1873 list_del_rcu(&event
->event_entry
);
1875 if (event
->group_leader
== event
)
1876 del_event_from_groups(event
, ctx
);
1879 * If event was in error state, then keep it
1880 * that way, otherwise bogus counts will be
1881 * returned on read(). The only way to get out
1882 * of error state is by explicit re-enabling
1885 if (event
->state
> PERF_EVENT_STATE_OFF
)
1886 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1892 perf_aux_output_match(struct perf_event
*event
, struct perf_event
*aux_event
)
1894 if (!has_aux(aux_event
))
1897 if (!event
->pmu
->aux_output_match
)
1900 return event
->pmu
->aux_output_match(aux_event
);
1903 static void put_event(struct perf_event
*event
);
1904 static void event_sched_out(struct perf_event
*event
,
1905 struct perf_cpu_context
*cpuctx
,
1906 struct perf_event_context
*ctx
);
1908 static void perf_put_aux_event(struct perf_event
*event
)
1910 struct perf_event_context
*ctx
= event
->ctx
;
1911 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1912 struct perf_event
*iter
;
1915 * If event uses aux_event tear down the link
1917 if (event
->aux_event
) {
1918 iter
= event
->aux_event
;
1919 event
->aux_event
= NULL
;
1925 * If the event is an aux_event, tear down all links to
1926 * it from other events.
1928 for_each_sibling_event(iter
, event
->group_leader
) {
1929 if (iter
->aux_event
!= event
)
1932 iter
->aux_event
= NULL
;
1936 * If it's ACTIVE, schedule it out and put it into ERROR
1937 * state so that we don't try to schedule it again. Note
1938 * that perf_event_enable() will clear the ERROR status.
1940 event_sched_out(iter
, cpuctx
, ctx
);
1941 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
1945 static bool perf_need_aux_event(struct perf_event
*event
)
1947 return !!event
->attr
.aux_output
|| !!event
->attr
.aux_sample_size
;
1950 static int perf_get_aux_event(struct perf_event
*event
,
1951 struct perf_event
*group_leader
)
1954 * Our group leader must be an aux event if we want to be
1955 * an aux_output. This way, the aux event will precede its
1956 * aux_output events in the group, and therefore will always
1963 * aux_output and aux_sample_size are mutually exclusive.
1965 if (event
->attr
.aux_output
&& event
->attr
.aux_sample_size
)
1968 if (event
->attr
.aux_output
&&
1969 !perf_aux_output_match(event
, group_leader
))
1972 if (event
->attr
.aux_sample_size
&& !group_leader
->pmu
->snapshot_aux
)
1975 if (!atomic_long_inc_not_zero(&group_leader
->refcount
))
1979 * Link aux_outputs to their aux event; this is undone in
1980 * perf_group_detach() by perf_put_aux_event(). When the
1981 * group in torn down, the aux_output events loose their
1982 * link to the aux_event and can't schedule any more.
1984 event
->aux_event
= group_leader
;
1989 static void perf_group_detach(struct perf_event
*event
)
1991 struct perf_event
*sibling
, *tmp
;
1992 struct perf_event_context
*ctx
= event
->ctx
;
1994 lockdep_assert_held(&ctx
->lock
);
1997 * We can have double detach due to exit/hot-unplug + close.
1999 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
2002 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
2004 perf_put_aux_event(event
);
2007 * If this is a sibling, remove it from its group.
2009 if (event
->group_leader
!= event
) {
2010 list_del_init(&event
->sibling_list
);
2011 event
->group_leader
->nr_siblings
--;
2016 * If this was a group event with sibling events then
2017 * upgrade the siblings to singleton events by adding them
2018 * to whatever list we are on.
2020 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, sibling_list
) {
2022 sibling
->group_leader
= sibling
;
2023 list_del_init(&sibling
->sibling_list
);
2025 /* Inherit group flags from the previous leader */
2026 sibling
->group_caps
= event
->group_caps
;
2028 if (!RB_EMPTY_NODE(&event
->group_node
)) {
2029 add_event_to_groups(sibling
, event
->ctx
);
2031 if (sibling
->state
== PERF_EVENT_STATE_ACTIVE
) {
2032 struct list_head
*list
= sibling
->attr
.pinned
?
2033 &ctx
->pinned_active
: &ctx
->flexible_active
;
2035 list_add_tail(&sibling
->active_list
, list
);
2039 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
2043 perf_event__header_size(event
->group_leader
);
2045 for_each_sibling_event(tmp
, event
->group_leader
)
2046 perf_event__header_size(tmp
);
2049 static bool is_orphaned_event(struct perf_event
*event
)
2051 return event
->state
== PERF_EVENT_STATE_DEAD
;
2054 static inline int __pmu_filter_match(struct perf_event
*event
)
2056 struct pmu
*pmu
= event
->pmu
;
2057 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
2061 * Check whether we should attempt to schedule an event group based on
2062 * PMU-specific filtering. An event group can consist of HW and SW events,
2063 * potentially with a SW leader, so we must check all the filters, to
2064 * determine whether a group is schedulable:
2066 static inline int pmu_filter_match(struct perf_event
*event
)
2068 struct perf_event
*sibling
;
2070 if (!__pmu_filter_match(event
))
2073 for_each_sibling_event(sibling
, event
) {
2074 if (!__pmu_filter_match(sibling
))
2082 event_filter_match(struct perf_event
*event
)
2084 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
2085 perf_cgroup_match(event
) && pmu_filter_match(event
);
2089 event_sched_out(struct perf_event
*event
,
2090 struct perf_cpu_context
*cpuctx
,
2091 struct perf_event_context
*ctx
)
2093 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
2095 WARN_ON_ONCE(event
->ctx
!= ctx
);
2096 lockdep_assert_held(&ctx
->lock
);
2098 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2102 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2103 * we can schedule events _OUT_ individually through things like
2104 * __perf_remove_from_context().
2106 list_del_init(&event
->active_list
);
2108 perf_pmu_disable(event
->pmu
);
2110 event
->pmu
->del(event
, 0);
2113 if (READ_ONCE(event
->pending_disable
) >= 0) {
2114 WRITE_ONCE(event
->pending_disable
, -1);
2115 state
= PERF_EVENT_STATE_OFF
;
2117 perf_event_set_state(event
, state
);
2119 if (!is_software_event(event
))
2120 cpuctx
->active_oncpu
--;
2121 if (!--ctx
->nr_active
)
2122 perf_event_ctx_deactivate(ctx
);
2123 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2125 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
2126 cpuctx
->exclusive
= 0;
2128 perf_pmu_enable(event
->pmu
);
2132 group_sched_out(struct perf_event
*group_event
,
2133 struct perf_cpu_context
*cpuctx
,
2134 struct perf_event_context
*ctx
)
2136 struct perf_event
*event
;
2138 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2141 perf_pmu_disable(ctx
->pmu
);
2143 event_sched_out(group_event
, cpuctx
, ctx
);
2146 * Schedule out siblings (if any):
2148 for_each_sibling_event(event
, group_event
)
2149 event_sched_out(event
, cpuctx
, ctx
);
2151 perf_pmu_enable(ctx
->pmu
);
2153 if (group_event
->attr
.exclusive
)
2154 cpuctx
->exclusive
= 0;
2157 #define DETACH_GROUP 0x01UL
2160 * Cross CPU call to remove a performance event
2162 * We disable the event on the hardware level first. After that we
2163 * remove it from the context list.
2166 __perf_remove_from_context(struct perf_event
*event
,
2167 struct perf_cpu_context
*cpuctx
,
2168 struct perf_event_context
*ctx
,
2171 unsigned long flags
= (unsigned long)info
;
2173 if (ctx
->is_active
& EVENT_TIME
) {
2174 update_context_time(ctx
);
2175 update_cgrp_time_from_cpuctx(cpuctx
);
2178 event_sched_out(event
, cpuctx
, ctx
);
2179 if (flags
& DETACH_GROUP
)
2180 perf_group_detach(event
);
2181 list_del_event(event
, ctx
);
2183 if (!ctx
->nr_events
&& ctx
->is_active
) {
2186 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2187 cpuctx
->task_ctx
= NULL
;
2193 * Remove the event from a task's (or a CPU's) list of events.
2195 * If event->ctx is a cloned context, callers must make sure that
2196 * every task struct that event->ctx->task could possibly point to
2197 * remains valid. This is OK when called from perf_release since
2198 * that only calls us on the top-level context, which can't be a clone.
2199 * When called from perf_event_exit_task, it's OK because the
2200 * context has been detached from its task.
2202 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
2204 struct perf_event_context
*ctx
= event
->ctx
;
2206 lockdep_assert_held(&ctx
->mutex
);
2208 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
2211 * The above event_function_call() can NO-OP when it hits
2212 * TASK_TOMBSTONE. In that case we must already have been detached
2213 * from the context (by perf_event_exit_event()) but the grouping
2214 * might still be in-tact.
2216 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
2217 if ((flags
& DETACH_GROUP
) &&
2218 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
2220 * Since in that case we cannot possibly be scheduled, simply
2223 raw_spin_lock_irq(&ctx
->lock
);
2224 perf_group_detach(event
);
2225 raw_spin_unlock_irq(&ctx
->lock
);
2230 * Cross CPU call to disable a performance event
2232 static void __perf_event_disable(struct perf_event
*event
,
2233 struct perf_cpu_context
*cpuctx
,
2234 struct perf_event_context
*ctx
,
2237 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
2240 if (ctx
->is_active
& EVENT_TIME
) {
2241 update_context_time(ctx
);
2242 update_cgrp_time_from_event(event
);
2245 if (event
== event
->group_leader
)
2246 group_sched_out(event
, cpuctx
, ctx
);
2248 event_sched_out(event
, cpuctx
, ctx
);
2250 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2256 * If event->ctx is a cloned context, callers must make sure that
2257 * every task struct that event->ctx->task could possibly point to
2258 * remains valid. This condition is satisfied when called through
2259 * perf_event_for_each_child or perf_event_for_each because they
2260 * hold the top-level event's child_mutex, so any descendant that
2261 * goes to exit will block in perf_event_exit_event().
2263 * When called from perf_pending_event it's OK because event->ctx
2264 * is the current context on this CPU and preemption is disabled,
2265 * hence we can't get into perf_event_task_sched_out for this context.
2267 static void _perf_event_disable(struct perf_event
*event
)
2269 struct perf_event_context
*ctx
= event
->ctx
;
2271 raw_spin_lock_irq(&ctx
->lock
);
2272 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2273 raw_spin_unlock_irq(&ctx
->lock
);
2276 raw_spin_unlock_irq(&ctx
->lock
);
2278 event_function_call(event
, __perf_event_disable
, NULL
);
2281 void perf_event_disable_local(struct perf_event
*event
)
2283 event_function_local(event
, __perf_event_disable
, NULL
);
2287 * Strictly speaking kernel users cannot create groups and therefore this
2288 * interface does not need the perf_event_ctx_lock() magic.
2290 void perf_event_disable(struct perf_event
*event
)
2292 struct perf_event_context
*ctx
;
2294 ctx
= perf_event_ctx_lock(event
);
2295 _perf_event_disable(event
);
2296 perf_event_ctx_unlock(event
, ctx
);
2298 EXPORT_SYMBOL_GPL(perf_event_disable
);
2300 void perf_event_disable_inatomic(struct perf_event
*event
)
2302 WRITE_ONCE(event
->pending_disable
, smp_processor_id());
2303 /* can fail, see perf_pending_event_disable() */
2304 irq_work_queue(&event
->pending
);
2307 static void perf_set_shadow_time(struct perf_event
*event
,
2308 struct perf_event_context
*ctx
)
2311 * use the correct time source for the time snapshot
2313 * We could get by without this by leveraging the
2314 * fact that to get to this function, the caller
2315 * has most likely already called update_context_time()
2316 * and update_cgrp_time_xx() and thus both timestamp
2317 * are identical (or very close). Given that tstamp is,
2318 * already adjusted for cgroup, we could say that:
2319 * tstamp - ctx->timestamp
2321 * tstamp - cgrp->timestamp.
2323 * Then, in perf_output_read(), the calculation would
2324 * work with no changes because:
2325 * - event is guaranteed scheduled in
2326 * - no scheduled out in between
2327 * - thus the timestamp would be the same
2329 * But this is a bit hairy.
2331 * So instead, we have an explicit cgroup call to remain
2332 * within the time time source all along. We believe it
2333 * is cleaner and simpler to understand.
2335 if (is_cgroup_event(event
))
2336 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2338 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2341 #define MAX_INTERRUPTS (~0ULL)
2343 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2344 static void perf_log_itrace_start(struct perf_event
*event
);
2347 event_sched_in(struct perf_event
*event
,
2348 struct perf_cpu_context
*cpuctx
,
2349 struct perf_event_context
*ctx
)
2353 lockdep_assert_held(&ctx
->lock
);
2355 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2358 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2360 * Order event::oncpu write to happen before the ACTIVE state is
2361 * visible. This allows perf_event_{stop,read}() to observe the correct
2362 * ->oncpu if it sees ACTIVE.
2365 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2368 * Unthrottle events, since we scheduled we might have missed several
2369 * ticks already, also for a heavily scheduling task there is little
2370 * guarantee it'll get a tick in a timely manner.
2372 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2373 perf_log_throttle(event
, 1);
2374 event
->hw
.interrupts
= 0;
2377 perf_pmu_disable(event
->pmu
);
2379 perf_set_shadow_time(event
, ctx
);
2381 perf_log_itrace_start(event
);
2383 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2384 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2390 if (!is_software_event(event
))
2391 cpuctx
->active_oncpu
++;
2392 if (!ctx
->nr_active
++)
2393 perf_event_ctx_activate(ctx
);
2394 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2397 if (event
->attr
.exclusive
)
2398 cpuctx
->exclusive
= 1;
2401 perf_pmu_enable(event
->pmu
);
2407 group_sched_in(struct perf_event
*group_event
,
2408 struct perf_cpu_context
*cpuctx
,
2409 struct perf_event_context
*ctx
)
2411 struct perf_event
*event
, *partial_group
= NULL
;
2412 struct pmu
*pmu
= ctx
->pmu
;
2414 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2417 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2419 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2420 pmu
->cancel_txn(pmu
);
2421 perf_mux_hrtimer_restart(cpuctx
);
2426 * Schedule in siblings as one group (if any):
2428 for_each_sibling_event(event
, group_event
) {
2429 if (event_sched_in(event
, cpuctx
, ctx
)) {
2430 partial_group
= event
;
2435 if (!pmu
->commit_txn(pmu
))
2440 * Groups can be scheduled in as one unit only, so undo any
2441 * partial group before returning:
2442 * The events up to the failed event are scheduled out normally.
2444 for_each_sibling_event(event
, group_event
) {
2445 if (event
== partial_group
)
2448 event_sched_out(event
, cpuctx
, ctx
);
2450 event_sched_out(group_event
, cpuctx
, ctx
);
2452 pmu
->cancel_txn(pmu
);
2454 perf_mux_hrtimer_restart(cpuctx
);
2460 * Work out whether we can put this event group on the CPU now.
2462 static int group_can_go_on(struct perf_event
*event
,
2463 struct perf_cpu_context
*cpuctx
,
2467 * Groups consisting entirely of software events can always go on.
2469 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2472 * If an exclusive group is already on, no other hardware
2475 if (cpuctx
->exclusive
)
2478 * If this group is exclusive and there are already
2479 * events on the CPU, it can't go on.
2481 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2484 * Otherwise, try to add it if all previous groups were able
2490 static void add_event_to_ctx(struct perf_event
*event
,
2491 struct perf_event_context
*ctx
)
2493 list_add_event(event
, ctx
);
2494 perf_group_attach(event
);
2497 static void ctx_sched_out(struct perf_event_context
*ctx
,
2498 struct perf_cpu_context
*cpuctx
,
2499 enum event_type_t event_type
);
2501 ctx_sched_in(struct perf_event_context
*ctx
,
2502 struct perf_cpu_context
*cpuctx
,
2503 enum event_type_t event_type
,
2504 struct task_struct
*task
);
2506 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2507 struct perf_event_context
*ctx
,
2508 enum event_type_t event_type
)
2510 if (!cpuctx
->task_ctx
)
2513 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2516 ctx_sched_out(ctx
, cpuctx
, event_type
);
2519 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2520 struct perf_event_context
*ctx
,
2521 struct task_struct
*task
)
2523 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2525 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2526 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2528 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2532 * We want to maintain the following priority of scheduling:
2533 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2534 * - task pinned (EVENT_PINNED)
2535 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2536 * - task flexible (EVENT_FLEXIBLE).
2538 * In order to avoid unscheduling and scheduling back in everything every
2539 * time an event is added, only do it for the groups of equal priority and
2542 * This can be called after a batch operation on task events, in which case
2543 * event_type is a bit mask of the types of events involved. For CPU events,
2544 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2546 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2547 struct perf_event_context
*task_ctx
,
2548 enum event_type_t event_type
)
2550 enum event_type_t ctx_event_type
;
2551 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2554 * If pinned groups are involved, flexible groups also need to be
2557 if (event_type
& EVENT_PINNED
)
2558 event_type
|= EVENT_FLEXIBLE
;
2560 ctx_event_type
= event_type
& EVENT_ALL
;
2562 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2564 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2567 * Decide which cpu ctx groups to schedule out based on the types
2568 * of events that caused rescheduling:
2569 * - EVENT_CPU: schedule out corresponding groups;
2570 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2571 * - otherwise, do nothing more.
2574 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2575 else if (ctx_event_type
& EVENT_PINNED
)
2576 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2578 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2579 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2582 void perf_pmu_resched(struct pmu
*pmu
)
2584 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2585 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2587 perf_ctx_lock(cpuctx
, task_ctx
);
2588 ctx_resched(cpuctx
, task_ctx
, EVENT_ALL
|EVENT_CPU
);
2589 perf_ctx_unlock(cpuctx
, task_ctx
);
2593 * Cross CPU call to install and enable a performance event
2595 * Very similar to remote_function() + event_function() but cannot assume that
2596 * things like ctx->is_active and cpuctx->task_ctx are set.
2598 static int __perf_install_in_context(void *info
)
2600 struct perf_event
*event
= info
;
2601 struct perf_event_context
*ctx
= event
->ctx
;
2602 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2603 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2604 bool reprogram
= true;
2607 raw_spin_lock(&cpuctx
->ctx
.lock
);
2609 raw_spin_lock(&ctx
->lock
);
2612 reprogram
= (ctx
->task
== current
);
2615 * If the task is running, it must be running on this CPU,
2616 * otherwise we cannot reprogram things.
2618 * If its not running, we don't care, ctx->lock will
2619 * serialize against it becoming runnable.
2621 if (task_curr(ctx
->task
) && !reprogram
) {
2626 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2627 } else if (task_ctx
) {
2628 raw_spin_lock(&task_ctx
->lock
);
2631 #ifdef CONFIG_CGROUP_PERF
2632 if (is_cgroup_event(event
)) {
2634 * If the current cgroup doesn't match the event's
2635 * cgroup, we should not try to schedule it.
2637 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2638 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2639 event
->cgrp
->css
.cgroup
);
2644 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2645 add_event_to_ctx(event
, ctx
);
2646 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2648 add_event_to_ctx(event
, ctx
);
2652 perf_ctx_unlock(cpuctx
, task_ctx
);
2657 static bool exclusive_event_installable(struct perf_event
*event
,
2658 struct perf_event_context
*ctx
);
2661 * Attach a performance event to a context.
2663 * Very similar to event_function_call, see comment there.
2666 perf_install_in_context(struct perf_event_context
*ctx
,
2667 struct perf_event
*event
,
2670 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2672 lockdep_assert_held(&ctx
->mutex
);
2674 WARN_ON_ONCE(!exclusive_event_installable(event
, ctx
));
2676 if (event
->cpu
!= -1)
2680 * Ensures that if we can observe event->ctx, both the event and ctx
2681 * will be 'complete'. See perf_iterate_sb_cpu().
2683 smp_store_release(&event
->ctx
, ctx
);
2686 * perf_event_attr::disabled events will not run and can be initialized
2687 * without IPI. Except when this is the first event for the context, in
2688 * that case we need the magic of the IPI to set ctx->is_active.
2690 * The IOC_ENABLE that is sure to follow the creation of a disabled
2691 * event will issue the IPI and reprogram the hardware.
2693 if (__perf_effective_state(event
) == PERF_EVENT_STATE_OFF
&& ctx
->nr_events
) {
2694 raw_spin_lock_irq(&ctx
->lock
);
2695 if (ctx
->task
== TASK_TOMBSTONE
) {
2696 raw_spin_unlock_irq(&ctx
->lock
);
2699 add_event_to_ctx(event
, ctx
);
2700 raw_spin_unlock_irq(&ctx
->lock
);
2705 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2710 * Should not happen, we validate the ctx is still alive before calling.
2712 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2716 * Installing events is tricky because we cannot rely on ctx->is_active
2717 * to be set in case this is the nr_events 0 -> 1 transition.
2719 * Instead we use task_curr(), which tells us if the task is running.
2720 * However, since we use task_curr() outside of rq::lock, we can race
2721 * against the actual state. This means the result can be wrong.
2723 * If we get a false positive, we retry, this is harmless.
2725 * If we get a false negative, things are complicated. If we are after
2726 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2727 * value must be correct. If we're before, it doesn't matter since
2728 * perf_event_context_sched_in() will program the counter.
2730 * However, this hinges on the remote context switch having observed
2731 * our task->perf_event_ctxp[] store, such that it will in fact take
2732 * ctx::lock in perf_event_context_sched_in().
2734 * We do this by task_function_call(), if the IPI fails to hit the task
2735 * we know any future context switch of task must see the
2736 * perf_event_ctpx[] store.
2740 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2741 * task_cpu() load, such that if the IPI then does not find the task
2742 * running, a future context switch of that task must observe the
2747 if (!task_function_call(task
, __perf_install_in_context
, event
))
2750 raw_spin_lock_irq(&ctx
->lock
);
2752 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2754 * Cannot happen because we already checked above (which also
2755 * cannot happen), and we hold ctx->mutex, which serializes us
2756 * against perf_event_exit_task_context().
2758 raw_spin_unlock_irq(&ctx
->lock
);
2762 * If the task is not running, ctx->lock will avoid it becoming so,
2763 * thus we can safely install the event.
2765 if (task_curr(task
)) {
2766 raw_spin_unlock_irq(&ctx
->lock
);
2769 add_event_to_ctx(event
, ctx
);
2770 raw_spin_unlock_irq(&ctx
->lock
);
2774 * Cross CPU call to enable a performance event
2776 static void __perf_event_enable(struct perf_event
*event
,
2777 struct perf_cpu_context
*cpuctx
,
2778 struct perf_event_context
*ctx
,
2781 struct perf_event
*leader
= event
->group_leader
;
2782 struct perf_event_context
*task_ctx
;
2784 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2785 event
->state
<= PERF_EVENT_STATE_ERROR
)
2789 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2791 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2793 if (!ctx
->is_active
)
2796 if (!event_filter_match(event
)) {
2797 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2802 * If the event is in a group and isn't the group leader,
2803 * then don't put it on unless the group is on.
2805 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2806 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2810 task_ctx
= cpuctx
->task_ctx
;
2812 WARN_ON_ONCE(task_ctx
!= ctx
);
2814 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2820 * If event->ctx is a cloned context, callers must make sure that
2821 * every task struct that event->ctx->task could possibly point to
2822 * remains valid. This condition is satisfied when called through
2823 * perf_event_for_each_child or perf_event_for_each as described
2824 * for perf_event_disable.
2826 static void _perf_event_enable(struct perf_event
*event
)
2828 struct perf_event_context
*ctx
= event
->ctx
;
2830 raw_spin_lock_irq(&ctx
->lock
);
2831 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2832 event
->state
< PERF_EVENT_STATE_ERROR
) {
2833 raw_spin_unlock_irq(&ctx
->lock
);
2838 * If the event is in error state, clear that first.
2840 * That way, if we see the event in error state below, we know that it
2841 * has gone back into error state, as distinct from the task having
2842 * been scheduled away before the cross-call arrived.
2844 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2845 event
->state
= PERF_EVENT_STATE_OFF
;
2846 raw_spin_unlock_irq(&ctx
->lock
);
2848 event_function_call(event
, __perf_event_enable
, NULL
);
2852 * See perf_event_disable();
2854 void perf_event_enable(struct perf_event
*event
)
2856 struct perf_event_context
*ctx
;
2858 ctx
= perf_event_ctx_lock(event
);
2859 _perf_event_enable(event
);
2860 perf_event_ctx_unlock(event
, ctx
);
2862 EXPORT_SYMBOL_GPL(perf_event_enable
);
2864 struct stop_event_data
{
2865 struct perf_event
*event
;
2866 unsigned int restart
;
2869 static int __perf_event_stop(void *info
)
2871 struct stop_event_data
*sd
= info
;
2872 struct perf_event
*event
= sd
->event
;
2874 /* if it's already INACTIVE, do nothing */
2875 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2878 /* matches smp_wmb() in event_sched_in() */
2882 * There is a window with interrupts enabled before we get here,
2883 * so we need to check again lest we try to stop another CPU's event.
2885 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2888 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2891 * May race with the actual stop (through perf_pmu_output_stop()),
2892 * but it is only used for events with AUX ring buffer, and such
2893 * events will refuse to restart because of rb::aux_mmap_count==0,
2894 * see comments in perf_aux_output_begin().
2896 * Since this is happening on an event-local CPU, no trace is lost
2900 event
->pmu
->start(event
, 0);
2905 static int perf_event_stop(struct perf_event
*event
, int restart
)
2907 struct stop_event_data sd
= {
2914 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2917 /* matches smp_wmb() in event_sched_in() */
2921 * We only want to restart ACTIVE events, so if the event goes
2922 * inactive here (event->oncpu==-1), there's nothing more to do;
2923 * fall through with ret==-ENXIO.
2925 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2926 __perf_event_stop
, &sd
);
2927 } while (ret
== -EAGAIN
);
2933 * In order to contain the amount of racy and tricky in the address filter
2934 * configuration management, it is a two part process:
2936 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2937 * we update the addresses of corresponding vmas in
2938 * event::addr_filter_ranges array and bump the event::addr_filters_gen;
2939 * (p2) when an event is scheduled in (pmu::add), it calls
2940 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2941 * if the generation has changed since the previous call.
2943 * If (p1) happens while the event is active, we restart it to force (p2).
2945 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2946 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2948 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2949 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2951 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2954 void perf_event_addr_filters_sync(struct perf_event
*event
)
2956 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2958 if (!has_addr_filter(event
))
2961 raw_spin_lock(&ifh
->lock
);
2962 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2963 event
->pmu
->addr_filters_sync(event
);
2964 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2966 raw_spin_unlock(&ifh
->lock
);
2968 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2970 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2973 * not supported on inherited events
2975 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2978 atomic_add(refresh
, &event
->event_limit
);
2979 _perf_event_enable(event
);
2985 * See perf_event_disable()
2987 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2989 struct perf_event_context
*ctx
;
2992 ctx
= perf_event_ctx_lock(event
);
2993 ret
= _perf_event_refresh(event
, refresh
);
2994 perf_event_ctx_unlock(event
, ctx
);
2998 EXPORT_SYMBOL_GPL(perf_event_refresh
);
3000 static int perf_event_modify_breakpoint(struct perf_event
*bp
,
3001 struct perf_event_attr
*attr
)
3005 _perf_event_disable(bp
);
3007 err
= modify_user_hw_breakpoint_check(bp
, attr
, true);
3009 if (!bp
->attr
.disabled
)
3010 _perf_event_enable(bp
);
3015 static int perf_event_modify_attr(struct perf_event
*event
,
3016 struct perf_event_attr
*attr
)
3018 if (event
->attr
.type
!= attr
->type
)
3021 switch (event
->attr
.type
) {
3022 case PERF_TYPE_BREAKPOINT
:
3023 return perf_event_modify_breakpoint(event
, attr
);
3025 /* Place holder for future additions. */
3030 static void ctx_sched_out(struct perf_event_context
*ctx
,
3031 struct perf_cpu_context
*cpuctx
,
3032 enum event_type_t event_type
)
3034 struct perf_event
*event
, *tmp
;
3035 int is_active
= ctx
->is_active
;
3037 lockdep_assert_held(&ctx
->lock
);
3039 if (likely(!ctx
->nr_events
)) {
3041 * See __perf_remove_from_context().
3043 WARN_ON_ONCE(ctx
->is_active
);
3045 WARN_ON_ONCE(cpuctx
->task_ctx
);
3049 ctx
->is_active
&= ~event_type
;
3050 if (!(ctx
->is_active
& EVENT_ALL
))
3054 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3055 if (!ctx
->is_active
)
3056 cpuctx
->task_ctx
= NULL
;
3060 * Always update time if it was set; not only when it changes.
3061 * Otherwise we can 'forget' to update time for any but the last
3062 * context we sched out. For example:
3064 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
3065 * ctx_sched_out(.event_type = EVENT_PINNED)
3067 * would only update time for the pinned events.
3069 if (is_active
& EVENT_TIME
) {
3070 /* update (and stop) ctx time */
3071 update_context_time(ctx
);
3072 update_cgrp_time_from_cpuctx(cpuctx
);
3075 is_active
^= ctx
->is_active
; /* changed bits */
3077 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
3081 * If we had been multiplexing, no rotations are necessary, now no events
3084 ctx
->rotate_necessary
= 0;
3086 perf_pmu_disable(ctx
->pmu
);
3087 if (is_active
& EVENT_PINNED
) {
3088 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_active
, active_list
)
3089 group_sched_out(event
, cpuctx
, ctx
);
3092 if (is_active
& EVENT_FLEXIBLE
) {
3093 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_active
, active_list
)
3094 group_sched_out(event
, cpuctx
, ctx
);
3096 perf_pmu_enable(ctx
->pmu
);
3100 * Test whether two contexts are equivalent, i.e. whether they have both been
3101 * cloned from the same version of the same context.
3103 * Equivalence is measured using a generation number in the context that is
3104 * incremented on each modification to it; see unclone_ctx(), list_add_event()
3105 * and list_del_event().
3107 static int context_equiv(struct perf_event_context
*ctx1
,
3108 struct perf_event_context
*ctx2
)
3110 lockdep_assert_held(&ctx1
->lock
);
3111 lockdep_assert_held(&ctx2
->lock
);
3113 /* Pinning disables the swap optimization */
3114 if (ctx1
->pin_count
|| ctx2
->pin_count
)
3117 /* If ctx1 is the parent of ctx2 */
3118 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
3121 /* If ctx2 is the parent of ctx1 */
3122 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
3126 * If ctx1 and ctx2 have the same parent; we flatten the parent
3127 * hierarchy, see perf_event_init_context().
3129 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
3130 ctx1
->parent_gen
== ctx2
->parent_gen
)
3137 static void __perf_event_sync_stat(struct perf_event
*event
,
3138 struct perf_event
*next_event
)
3142 if (!event
->attr
.inherit_stat
)
3146 * Update the event value, we cannot use perf_event_read()
3147 * because we're in the middle of a context switch and have IRQs
3148 * disabled, which upsets smp_call_function_single(), however
3149 * we know the event must be on the current CPU, therefore we
3150 * don't need to use it.
3152 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3153 event
->pmu
->read(event
);
3155 perf_event_update_time(event
);
3158 * In order to keep per-task stats reliable we need to flip the event
3159 * values when we flip the contexts.
3161 value
= local64_read(&next_event
->count
);
3162 value
= local64_xchg(&event
->count
, value
);
3163 local64_set(&next_event
->count
, value
);
3165 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
3166 swap(event
->total_time_running
, next_event
->total_time_running
);
3169 * Since we swizzled the values, update the user visible data too.
3171 perf_event_update_userpage(event
);
3172 perf_event_update_userpage(next_event
);
3175 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
3176 struct perf_event_context
*next_ctx
)
3178 struct perf_event
*event
, *next_event
;
3183 update_context_time(ctx
);
3185 event
= list_first_entry(&ctx
->event_list
,
3186 struct perf_event
, event_entry
);
3188 next_event
= list_first_entry(&next_ctx
->event_list
,
3189 struct perf_event
, event_entry
);
3191 while (&event
->event_entry
!= &ctx
->event_list
&&
3192 &next_event
->event_entry
!= &next_ctx
->event_list
) {
3194 __perf_event_sync_stat(event
, next_event
);
3196 event
= list_next_entry(event
, event_entry
);
3197 next_event
= list_next_entry(next_event
, event_entry
);
3201 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
3202 struct task_struct
*next
)
3204 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
3205 struct perf_event_context
*next_ctx
;
3206 struct perf_event_context
*parent
, *next_parent
;
3207 struct perf_cpu_context
*cpuctx
;
3213 cpuctx
= __get_cpu_context(ctx
);
3214 if (!cpuctx
->task_ctx
)
3218 next_ctx
= next
->perf_event_ctxp
[ctxn
];
3222 parent
= rcu_dereference(ctx
->parent_ctx
);
3223 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
3225 /* If neither context have a parent context; they cannot be clones. */
3226 if (!parent
&& !next_parent
)
3229 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
3231 * Looks like the two contexts are clones, so we might be
3232 * able to optimize the context switch. We lock both
3233 * contexts and check that they are clones under the
3234 * lock (including re-checking that neither has been
3235 * uncloned in the meantime). It doesn't matter which
3236 * order we take the locks because no other cpu could
3237 * be trying to lock both of these tasks.
3239 raw_spin_lock(&ctx
->lock
);
3240 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3241 if (context_equiv(ctx
, next_ctx
)) {
3242 struct pmu
*pmu
= ctx
->pmu
;
3244 WRITE_ONCE(ctx
->task
, next
);
3245 WRITE_ONCE(next_ctx
->task
, task
);
3248 * PMU specific parts of task perf context can require
3249 * additional synchronization. As an example of such
3250 * synchronization see implementation details of Intel
3251 * LBR call stack data profiling;
3253 if (pmu
->swap_task_ctx
)
3254 pmu
->swap_task_ctx(ctx
, next_ctx
);
3256 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3259 * RCU_INIT_POINTER here is safe because we've not
3260 * modified the ctx and the above modification of
3261 * ctx->task and ctx->task_ctx_data are immaterial
3262 * since those values are always verified under
3263 * ctx->lock which we're now holding.
3265 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3266 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3270 perf_event_sync_stat(ctx
, next_ctx
);
3272 raw_spin_unlock(&next_ctx
->lock
);
3273 raw_spin_unlock(&ctx
->lock
);
3279 raw_spin_lock(&ctx
->lock
);
3280 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3281 raw_spin_unlock(&ctx
->lock
);
3285 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3287 void perf_sched_cb_dec(struct pmu
*pmu
)
3289 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3291 this_cpu_dec(perf_sched_cb_usages
);
3293 if (!--cpuctx
->sched_cb_usage
)
3294 list_del(&cpuctx
->sched_cb_entry
);
3298 void perf_sched_cb_inc(struct pmu
*pmu
)
3300 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3302 if (!cpuctx
->sched_cb_usage
++)
3303 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3305 this_cpu_inc(perf_sched_cb_usages
);
3309 * This function provides the context switch callback to the lower code
3310 * layer. It is invoked ONLY when the context switch callback is enabled.
3312 * This callback is relevant even to per-cpu events; for example multi event
3313 * PEBS requires this to provide PID/TID information. This requires we flush
3314 * all queued PEBS records before we context switch to a new task.
3316 static void perf_pmu_sched_task(struct task_struct
*prev
,
3317 struct task_struct
*next
,
3320 struct perf_cpu_context
*cpuctx
;
3326 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3327 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3329 if (WARN_ON_ONCE(!pmu
->sched_task
))
3332 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3333 perf_pmu_disable(pmu
);
3335 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3337 perf_pmu_enable(pmu
);
3338 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3342 static void perf_event_switch(struct task_struct
*task
,
3343 struct task_struct
*next_prev
, bool sched_in
);
3345 #define for_each_task_context_nr(ctxn) \
3346 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3349 * Called from scheduler to remove the events of the current task,
3350 * with interrupts disabled.
3352 * We stop each event and update the event value in event->count.
3354 * This does not protect us against NMI, but disable()
3355 * sets the disabled bit in the control field of event _before_
3356 * accessing the event control register. If a NMI hits, then it will
3357 * not restart the event.
3359 void __perf_event_task_sched_out(struct task_struct
*task
,
3360 struct task_struct
*next
)
3364 if (__this_cpu_read(perf_sched_cb_usages
))
3365 perf_pmu_sched_task(task
, next
, false);
3367 if (atomic_read(&nr_switch_events
))
3368 perf_event_switch(task
, next
, false);
3370 for_each_task_context_nr(ctxn
)
3371 perf_event_context_sched_out(task
, ctxn
, next
);
3374 * if cgroup events exist on this CPU, then we need
3375 * to check if we have to switch out PMU state.
3376 * cgroup event are system-wide mode only
3378 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3379 perf_cgroup_sched_out(task
, next
);
3383 * Called with IRQs disabled
3385 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3386 enum event_type_t event_type
)
3388 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3391 static int visit_groups_merge(struct perf_event_groups
*groups
, int cpu
,
3392 int (*func
)(struct perf_event
*, void *), void *data
)
3394 struct perf_event
**evt
, *evt1
, *evt2
;
3397 evt1
= perf_event_groups_first(groups
, -1);
3398 evt2
= perf_event_groups_first(groups
, cpu
);
3400 while (evt1
|| evt2
) {
3402 if (evt1
->group_index
< evt2
->group_index
)
3412 ret
= func(*evt
, data
);
3416 *evt
= perf_event_groups_next(*evt
);
3422 struct sched_in_data
{
3423 struct perf_event_context
*ctx
;
3424 struct perf_cpu_context
*cpuctx
;
3428 static int pinned_sched_in(struct perf_event
*event
, void *data
)
3430 struct sched_in_data
*sid
= data
;
3432 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3435 if (!event_filter_match(event
))
3438 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3439 if (!group_sched_in(event
, sid
->cpuctx
, sid
->ctx
))
3440 list_add_tail(&event
->active_list
, &sid
->ctx
->pinned_active
);
3444 * If this pinned group hasn't been scheduled,
3445 * put it in error state.
3447 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3448 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3453 static int flexible_sched_in(struct perf_event
*event
, void *data
)
3455 struct sched_in_data
*sid
= data
;
3457 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3460 if (!event_filter_match(event
))
3463 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3464 int ret
= group_sched_in(event
, sid
->cpuctx
, sid
->ctx
);
3466 sid
->can_add_hw
= 0;
3467 sid
->ctx
->rotate_necessary
= 1;
3470 list_add_tail(&event
->active_list
, &sid
->ctx
->flexible_active
);
3477 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3478 struct perf_cpu_context
*cpuctx
)
3480 struct sched_in_data sid
= {
3486 visit_groups_merge(&ctx
->pinned_groups
,
3488 pinned_sched_in
, &sid
);
3492 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3493 struct perf_cpu_context
*cpuctx
)
3495 struct sched_in_data sid
= {
3501 visit_groups_merge(&ctx
->flexible_groups
,
3503 flexible_sched_in
, &sid
);
3507 ctx_sched_in(struct perf_event_context
*ctx
,
3508 struct perf_cpu_context
*cpuctx
,
3509 enum event_type_t event_type
,
3510 struct task_struct
*task
)
3512 int is_active
= ctx
->is_active
;
3515 lockdep_assert_held(&ctx
->lock
);
3517 if (likely(!ctx
->nr_events
))
3520 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3523 cpuctx
->task_ctx
= ctx
;
3525 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3528 is_active
^= ctx
->is_active
; /* changed bits */
3530 if (is_active
& EVENT_TIME
) {
3531 /* start ctx time */
3533 ctx
->timestamp
= now
;
3534 perf_cgroup_set_timestamp(task
, ctx
);
3538 * First go through the list and put on any pinned groups
3539 * in order to give them the best chance of going on.
3541 if (is_active
& EVENT_PINNED
)
3542 ctx_pinned_sched_in(ctx
, cpuctx
);
3544 /* Then walk through the lower prio flexible groups */
3545 if (is_active
& EVENT_FLEXIBLE
)
3546 ctx_flexible_sched_in(ctx
, cpuctx
);
3549 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3550 enum event_type_t event_type
,
3551 struct task_struct
*task
)
3553 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3555 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3558 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3559 struct task_struct
*task
)
3561 struct perf_cpu_context
*cpuctx
;
3563 cpuctx
= __get_cpu_context(ctx
);
3564 if (cpuctx
->task_ctx
== ctx
)
3567 perf_ctx_lock(cpuctx
, ctx
);
3569 * We must check ctx->nr_events while holding ctx->lock, such
3570 * that we serialize against perf_install_in_context().
3572 if (!ctx
->nr_events
)
3575 perf_pmu_disable(ctx
->pmu
);
3577 * We want to keep the following priority order:
3578 * cpu pinned (that don't need to move), task pinned,
3579 * cpu flexible, task flexible.
3581 * However, if task's ctx is not carrying any pinned
3582 * events, no need to flip the cpuctx's events around.
3584 if (!RB_EMPTY_ROOT(&ctx
->pinned_groups
.tree
))
3585 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3586 perf_event_sched_in(cpuctx
, ctx
, task
);
3587 perf_pmu_enable(ctx
->pmu
);
3590 perf_ctx_unlock(cpuctx
, ctx
);
3594 * Called from scheduler to add the events of the current task
3595 * with interrupts disabled.
3597 * We restore the event value and then enable it.
3599 * This does not protect us against NMI, but enable()
3600 * sets the enabled bit in the control field of event _before_
3601 * accessing the event control register. If a NMI hits, then it will
3602 * keep the event running.
3604 void __perf_event_task_sched_in(struct task_struct
*prev
,
3605 struct task_struct
*task
)
3607 struct perf_event_context
*ctx
;
3611 * If cgroup events exist on this CPU, then we need to check if we have
3612 * to switch in PMU state; cgroup event are system-wide mode only.
3614 * Since cgroup events are CPU events, we must schedule these in before
3615 * we schedule in the task events.
3617 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3618 perf_cgroup_sched_in(prev
, task
);
3620 for_each_task_context_nr(ctxn
) {
3621 ctx
= task
->perf_event_ctxp
[ctxn
];
3625 perf_event_context_sched_in(ctx
, task
);
3628 if (atomic_read(&nr_switch_events
))
3629 perf_event_switch(task
, prev
, true);
3631 if (__this_cpu_read(perf_sched_cb_usages
))
3632 perf_pmu_sched_task(prev
, task
, true);
3635 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3637 u64 frequency
= event
->attr
.sample_freq
;
3638 u64 sec
= NSEC_PER_SEC
;
3639 u64 divisor
, dividend
;
3641 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3643 count_fls
= fls64(count
);
3644 nsec_fls
= fls64(nsec
);
3645 frequency_fls
= fls64(frequency
);
3649 * We got @count in @nsec, with a target of sample_freq HZ
3650 * the target period becomes:
3653 * period = -------------------
3654 * @nsec * sample_freq
3659 * Reduce accuracy by one bit such that @a and @b converge
3660 * to a similar magnitude.
3662 #define REDUCE_FLS(a, b) \
3664 if (a##_fls > b##_fls) { \
3674 * Reduce accuracy until either term fits in a u64, then proceed with
3675 * the other, so that finally we can do a u64/u64 division.
3677 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3678 REDUCE_FLS(nsec
, frequency
);
3679 REDUCE_FLS(sec
, count
);
3682 if (count_fls
+ sec_fls
> 64) {
3683 divisor
= nsec
* frequency
;
3685 while (count_fls
+ sec_fls
> 64) {
3686 REDUCE_FLS(count
, sec
);
3690 dividend
= count
* sec
;
3692 dividend
= count
* sec
;
3694 while (nsec_fls
+ frequency_fls
> 64) {
3695 REDUCE_FLS(nsec
, frequency
);
3699 divisor
= nsec
* frequency
;
3705 return div64_u64(dividend
, divisor
);
3708 static DEFINE_PER_CPU(int, perf_throttled_count
);
3709 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3711 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3713 struct hw_perf_event
*hwc
= &event
->hw
;
3714 s64 period
, sample_period
;
3717 period
= perf_calculate_period(event
, nsec
, count
);
3719 delta
= (s64
)(period
- hwc
->sample_period
);
3720 delta
= (delta
+ 7) / 8; /* low pass filter */
3722 sample_period
= hwc
->sample_period
+ delta
;
3727 hwc
->sample_period
= sample_period
;
3729 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3731 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3733 local64_set(&hwc
->period_left
, 0);
3736 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3741 * combine freq adjustment with unthrottling to avoid two passes over the
3742 * events. At the same time, make sure, having freq events does not change
3743 * the rate of unthrottling as that would introduce bias.
3745 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3748 struct perf_event
*event
;
3749 struct hw_perf_event
*hwc
;
3750 u64 now
, period
= TICK_NSEC
;
3754 * only need to iterate over all events iff:
3755 * - context have events in frequency mode (needs freq adjust)
3756 * - there are events to unthrottle on this cpu
3758 if (!(ctx
->nr_freq
|| needs_unthr
))
3761 raw_spin_lock(&ctx
->lock
);
3762 perf_pmu_disable(ctx
->pmu
);
3764 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3765 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3768 if (!event_filter_match(event
))
3771 perf_pmu_disable(event
->pmu
);
3775 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3776 hwc
->interrupts
= 0;
3777 perf_log_throttle(event
, 1);
3778 event
->pmu
->start(event
, 0);
3781 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3785 * stop the event and update event->count
3787 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3789 now
= local64_read(&event
->count
);
3790 delta
= now
- hwc
->freq_count_stamp
;
3791 hwc
->freq_count_stamp
= now
;
3795 * reload only if value has changed
3796 * we have stopped the event so tell that
3797 * to perf_adjust_period() to avoid stopping it
3801 perf_adjust_period(event
, period
, delta
, false);
3803 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3805 perf_pmu_enable(event
->pmu
);
3808 perf_pmu_enable(ctx
->pmu
);
3809 raw_spin_unlock(&ctx
->lock
);
3813 * Move @event to the tail of the @ctx's elegible events.
3815 static void rotate_ctx(struct perf_event_context
*ctx
, struct perf_event
*event
)
3818 * Rotate the first entry last of non-pinned groups. Rotation might be
3819 * disabled by the inheritance code.
3821 if (ctx
->rotate_disable
)
3824 perf_event_groups_delete(&ctx
->flexible_groups
, event
);
3825 perf_event_groups_insert(&ctx
->flexible_groups
, event
);
3828 /* pick an event from the flexible_groups to rotate */
3829 static inline struct perf_event
*
3830 ctx_event_to_rotate(struct perf_event_context
*ctx
)
3832 struct perf_event
*event
;
3834 /* pick the first active flexible event */
3835 event
= list_first_entry_or_null(&ctx
->flexible_active
,
3836 struct perf_event
, active_list
);
3838 /* if no active flexible event, pick the first event */
3840 event
= rb_entry_safe(rb_first(&ctx
->flexible_groups
.tree
),
3841 typeof(*event
), group_node
);
3847 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3849 struct perf_event
*cpu_event
= NULL
, *task_event
= NULL
;
3850 struct perf_event_context
*task_ctx
= NULL
;
3851 int cpu_rotate
, task_rotate
;
3854 * Since we run this from IRQ context, nobody can install new
3855 * events, thus the event count values are stable.
3858 cpu_rotate
= cpuctx
->ctx
.rotate_necessary
;
3859 task_ctx
= cpuctx
->task_ctx
;
3860 task_rotate
= task_ctx
? task_ctx
->rotate_necessary
: 0;
3862 if (!(cpu_rotate
|| task_rotate
))
3865 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3866 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3869 task_event
= ctx_event_to_rotate(task_ctx
);
3871 cpu_event
= ctx_event_to_rotate(&cpuctx
->ctx
);
3874 * As per the order given at ctx_resched() first 'pop' task flexible
3875 * and then, if needed CPU flexible.
3877 if (task_event
|| (task_ctx
&& cpu_event
))
3878 ctx_sched_out(task_ctx
, cpuctx
, EVENT_FLEXIBLE
);
3880 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3883 rotate_ctx(task_ctx
, task_event
);
3885 rotate_ctx(&cpuctx
->ctx
, cpu_event
);
3887 perf_event_sched_in(cpuctx
, task_ctx
, current
);
3889 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3890 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3895 void perf_event_task_tick(void)
3897 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3898 struct perf_event_context
*ctx
, *tmp
;
3901 lockdep_assert_irqs_disabled();
3903 __this_cpu_inc(perf_throttled_seq
);
3904 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3905 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3907 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3908 perf_adjust_freq_unthr_context(ctx
, throttled
);
3911 static int event_enable_on_exec(struct perf_event
*event
,
3912 struct perf_event_context
*ctx
)
3914 if (!event
->attr
.enable_on_exec
)
3917 event
->attr
.enable_on_exec
= 0;
3918 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3921 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3927 * Enable all of a task's events that have been marked enable-on-exec.
3928 * This expects task == current.
3930 static void perf_event_enable_on_exec(int ctxn
)
3932 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3933 enum event_type_t event_type
= 0;
3934 struct perf_cpu_context
*cpuctx
;
3935 struct perf_event
*event
;
3936 unsigned long flags
;
3939 local_irq_save(flags
);
3940 ctx
= current
->perf_event_ctxp
[ctxn
];
3941 if (!ctx
|| !ctx
->nr_events
)
3944 cpuctx
= __get_cpu_context(ctx
);
3945 perf_ctx_lock(cpuctx
, ctx
);
3946 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3947 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3948 enabled
|= event_enable_on_exec(event
, ctx
);
3949 event_type
|= get_event_type(event
);
3953 * Unclone and reschedule this context if we enabled any event.
3956 clone_ctx
= unclone_ctx(ctx
);
3957 ctx_resched(cpuctx
, ctx
, event_type
);
3959 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3961 perf_ctx_unlock(cpuctx
, ctx
);
3964 local_irq_restore(flags
);
3970 struct perf_read_data
{
3971 struct perf_event
*event
;
3976 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3978 u16 local_pkg
, event_pkg
;
3980 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3981 int local_cpu
= smp_processor_id();
3983 event_pkg
= topology_physical_package_id(event_cpu
);
3984 local_pkg
= topology_physical_package_id(local_cpu
);
3986 if (event_pkg
== local_pkg
)
3994 * Cross CPU call to read the hardware event
3996 static void __perf_event_read(void *info
)
3998 struct perf_read_data
*data
= info
;
3999 struct perf_event
*sub
, *event
= data
->event
;
4000 struct perf_event_context
*ctx
= event
->ctx
;
4001 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
4002 struct pmu
*pmu
= event
->pmu
;
4005 * If this is a task context, we need to check whether it is
4006 * the current task context of this cpu. If not it has been
4007 * scheduled out before the smp call arrived. In that case
4008 * event->count would have been updated to a recent sample
4009 * when the event was scheduled out.
4011 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
4014 raw_spin_lock(&ctx
->lock
);
4015 if (ctx
->is_active
& EVENT_TIME
) {
4016 update_context_time(ctx
);
4017 update_cgrp_time_from_event(event
);
4020 perf_event_update_time(event
);
4022 perf_event_update_sibling_time(event
);
4024 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4033 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
4037 for_each_sibling_event(sub
, event
) {
4038 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
4040 * Use sibling's PMU rather than @event's since
4041 * sibling could be on different (eg: software) PMU.
4043 sub
->pmu
->read(sub
);
4047 data
->ret
= pmu
->commit_txn(pmu
);
4050 raw_spin_unlock(&ctx
->lock
);
4053 static inline u64
perf_event_count(struct perf_event
*event
)
4055 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
4059 * NMI-safe method to read a local event, that is an event that
4061 * - either for the current task, or for this CPU
4062 * - does not have inherit set, for inherited task events
4063 * will not be local and we cannot read them atomically
4064 * - must not have a pmu::count method
4066 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
4067 u64
*enabled
, u64
*running
)
4069 unsigned long flags
;
4073 * Disabling interrupts avoids all counter scheduling (context
4074 * switches, timer based rotation and IPIs).
4076 local_irq_save(flags
);
4079 * It must not be an event with inherit set, we cannot read
4080 * all child counters from atomic context.
4082 if (event
->attr
.inherit
) {
4087 /* If this is a per-task event, it must be for current */
4088 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
4089 event
->hw
.target
!= current
) {
4094 /* If this is a per-CPU event, it must be for this CPU */
4095 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
4096 event
->cpu
!= smp_processor_id()) {
4101 /* If this is a pinned event it must be running on this CPU */
4102 if (event
->attr
.pinned
&& event
->oncpu
!= smp_processor_id()) {
4108 * If the event is currently on this CPU, its either a per-task event,
4109 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
4112 if (event
->oncpu
== smp_processor_id())
4113 event
->pmu
->read(event
);
4115 *value
= local64_read(&event
->count
);
4116 if (enabled
|| running
) {
4117 u64 now
= event
->shadow_ctx_time
+ perf_clock();
4118 u64 __enabled
, __running
;
4120 __perf_update_times(event
, now
, &__enabled
, &__running
);
4122 *enabled
= __enabled
;
4124 *running
= __running
;
4127 local_irq_restore(flags
);
4132 static int perf_event_read(struct perf_event
*event
, bool group
)
4134 enum perf_event_state state
= READ_ONCE(event
->state
);
4135 int event_cpu
, ret
= 0;
4138 * If event is enabled and currently active on a CPU, update the
4139 * value in the event structure:
4142 if (state
== PERF_EVENT_STATE_ACTIVE
) {
4143 struct perf_read_data data
;
4146 * Orders the ->state and ->oncpu loads such that if we see
4147 * ACTIVE we must also see the right ->oncpu.
4149 * Matches the smp_wmb() from event_sched_in().
4153 event_cpu
= READ_ONCE(event
->oncpu
);
4154 if ((unsigned)event_cpu
>= nr_cpu_ids
)
4157 data
= (struct perf_read_data
){
4164 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
4167 * Purposely ignore the smp_call_function_single() return
4170 * If event_cpu isn't a valid CPU it means the event got
4171 * scheduled out and that will have updated the event count.
4173 * Therefore, either way, we'll have an up-to-date event count
4176 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
4180 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
4181 struct perf_event_context
*ctx
= event
->ctx
;
4182 unsigned long flags
;
4184 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4185 state
= event
->state
;
4186 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
4187 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4192 * May read while context is not active (e.g., thread is
4193 * blocked), in that case we cannot update context time
4195 if (ctx
->is_active
& EVENT_TIME
) {
4196 update_context_time(ctx
);
4197 update_cgrp_time_from_event(event
);
4200 perf_event_update_time(event
);
4202 perf_event_update_sibling_time(event
);
4203 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4210 * Initialize the perf_event context in a task_struct:
4212 static void __perf_event_init_context(struct perf_event_context
*ctx
)
4214 raw_spin_lock_init(&ctx
->lock
);
4215 mutex_init(&ctx
->mutex
);
4216 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
4217 perf_event_groups_init(&ctx
->pinned_groups
);
4218 perf_event_groups_init(&ctx
->flexible_groups
);
4219 INIT_LIST_HEAD(&ctx
->event_list
);
4220 INIT_LIST_HEAD(&ctx
->pinned_active
);
4221 INIT_LIST_HEAD(&ctx
->flexible_active
);
4222 refcount_set(&ctx
->refcount
, 1);
4225 static struct perf_event_context
*
4226 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
4228 struct perf_event_context
*ctx
;
4230 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
4234 __perf_event_init_context(ctx
);
4236 ctx
->task
= get_task_struct(task
);
4242 static struct task_struct
*
4243 find_lively_task_by_vpid(pid_t vpid
)
4245 struct task_struct
*task
;
4251 task
= find_task_by_vpid(vpid
);
4253 get_task_struct(task
);
4257 return ERR_PTR(-ESRCH
);
4263 * Returns a matching context with refcount and pincount.
4265 static struct perf_event_context
*
4266 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
4267 struct perf_event
*event
)
4269 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4270 struct perf_cpu_context
*cpuctx
;
4271 void *task_ctx_data
= NULL
;
4272 unsigned long flags
;
4274 int cpu
= event
->cpu
;
4277 /* Must be root to operate on a CPU event: */
4278 err
= perf_allow_cpu(&event
->attr
);
4280 return ERR_PTR(err
);
4282 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
4291 ctxn
= pmu
->task_ctx_nr
;
4295 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
4296 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
4297 if (!task_ctx_data
) {
4304 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
4306 clone_ctx
= unclone_ctx(ctx
);
4309 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
4310 ctx
->task_ctx_data
= task_ctx_data
;
4311 task_ctx_data
= NULL
;
4313 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4318 ctx
= alloc_perf_context(pmu
, task
);
4323 if (task_ctx_data
) {
4324 ctx
->task_ctx_data
= task_ctx_data
;
4325 task_ctx_data
= NULL
;
4329 mutex_lock(&task
->perf_event_mutex
);
4331 * If it has already passed perf_event_exit_task().
4332 * we must see PF_EXITING, it takes this mutex too.
4334 if (task
->flags
& PF_EXITING
)
4336 else if (task
->perf_event_ctxp
[ctxn
])
4341 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
4343 mutex_unlock(&task
->perf_event_mutex
);
4345 if (unlikely(err
)) {
4354 kfree(task_ctx_data
);
4358 kfree(task_ctx_data
);
4359 return ERR_PTR(err
);
4362 static void perf_event_free_filter(struct perf_event
*event
);
4363 static void perf_event_free_bpf_prog(struct perf_event
*event
);
4365 static void free_event_rcu(struct rcu_head
*head
)
4367 struct perf_event
*event
;
4369 event
= container_of(head
, struct perf_event
, rcu_head
);
4371 put_pid_ns(event
->ns
);
4372 perf_event_free_filter(event
);
4376 static void ring_buffer_attach(struct perf_event
*event
,
4377 struct perf_buffer
*rb
);
4379 static void detach_sb_event(struct perf_event
*event
)
4381 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4383 raw_spin_lock(&pel
->lock
);
4384 list_del_rcu(&event
->sb_list
);
4385 raw_spin_unlock(&pel
->lock
);
4388 static bool is_sb_event(struct perf_event
*event
)
4390 struct perf_event_attr
*attr
= &event
->attr
;
4395 if (event
->attach_state
& PERF_ATTACH_TASK
)
4398 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4399 attr
->comm
|| attr
->comm_exec
||
4400 attr
->task
|| attr
->ksymbol
||
4401 attr
->context_switch
||
4407 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4409 if (is_sb_event(event
))
4410 detach_sb_event(event
);
4413 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4418 if (is_cgroup_event(event
))
4419 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4422 #ifdef CONFIG_NO_HZ_FULL
4423 static DEFINE_SPINLOCK(nr_freq_lock
);
4426 static void unaccount_freq_event_nohz(void)
4428 #ifdef CONFIG_NO_HZ_FULL
4429 spin_lock(&nr_freq_lock
);
4430 if (atomic_dec_and_test(&nr_freq_events
))
4431 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4432 spin_unlock(&nr_freq_lock
);
4436 static void unaccount_freq_event(void)
4438 if (tick_nohz_full_enabled())
4439 unaccount_freq_event_nohz();
4441 atomic_dec(&nr_freq_events
);
4444 static void unaccount_event(struct perf_event
*event
)
4451 if (event
->attach_state
& PERF_ATTACH_TASK
)
4453 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4454 atomic_dec(&nr_mmap_events
);
4455 if (event
->attr
.comm
)
4456 atomic_dec(&nr_comm_events
);
4457 if (event
->attr
.namespaces
)
4458 atomic_dec(&nr_namespaces_events
);
4459 if (event
->attr
.task
)
4460 atomic_dec(&nr_task_events
);
4461 if (event
->attr
.freq
)
4462 unaccount_freq_event();
4463 if (event
->attr
.context_switch
) {
4465 atomic_dec(&nr_switch_events
);
4467 if (is_cgroup_event(event
))
4469 if (has_branch_stack(event
))
4471 if (event
->attr
.ksymbol
)
4472 atomic_dec(&nr_ksymbol_events
);
4473 if (event
->attr
.bpf_event
)
4474 atomic_dec(&nr_bpf_events
);
4477 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4478 schedule_delayed_work(&perf_sched_work
, HZ
);
4481 unaccount_event_cpu(event
, event
->cpu
);
4483 unaccount_pmu_sb_event(event
);
4486 static void perf_sched_delayed(struct work_struct
*work
)
4488 mutex_lock(&perf_sched_mutex
);
4489 if (atomic_dec_and_test(&perf_sched_count
))
4490 static_branch_disable(&perf_sched_events
);
4491 mutex_unlock(&perf_sched_mutex
);
4495 * The following implement mutual exclusion of events on "exclusive" pmus
4496 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4497 * at a time, so we disallow creating events that might conflict, namely:
4499 * 1) cpu-wide events in the presence of per-task events,
4500 * 2) per-task events in the presence of cpu-wide events,
4501 * 3) two matching events on the same context.
4503 * The former two cases are handled in the allocation path (perf_event_alloc(),
4504 * _free_event()), the latter -- before the first perf_install_in_context().
4506 static int exclusive_event_init(struct perf_event
*event
)
4508 struct pmu
*pmu
= event
->pmu
;
4510 if (!is_exclusive_pmu(pmu
))
4514 * Prevent co-existence of per-task and cpu-wide events on the
4515 * same exclusive pmu.
4517 * Negative pmu::exclusive_cnt means there are cpu-wide
4518 * events on this "exclusive" pmu, positive means there are
4521 * Since this is called in perf_event_alloc() path, event::ctx
4522 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4523 * to mean "per-task event", because unlike other attach states it
4524 * never gets cleared.
4526 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4527 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4530 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4537 static void exclusive_event_destroy(struct perf_event
*event
)
4539 struct pmu
*pmu
= event
->pmu
;
4541 if (!is_exclusive_pmu(pmu
))
4544 /* see comment in exclusive_event_init() */
4545 if (event
->attach_state
& PERF_ATTACH_TASK
)
4546 atomic_dec(&pmu
->exclusive_cnt
);
4548 atomic_inc(&pmu
->exclusive_cnt
);
4551 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4553 if ((e1
->pmu
== e2
->pmu
) &&
4554 (e1
->cpu
== e2
->cpu
||
4561 static bool exclusive_event_installable(struct perf_event
*event
,
4562 struct perf_event_context
*ctx
)
4564 struct perf_event
*iter_event
;
4565 struct pmu
*pmu
= event
->pmu
;
4567 lockdep_assert_held(&ctx
->mutex
);
4569 if (!is_exclusive_pmu(pmu
))
4572 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4573 if (exclusive_event_match(iter_event
, event
))
4580 static void perf_addr_filters_splice(struct perf_event
*event
,
4581 struct list_head
*head
);
4583 static void _free_event(struct perf_event
*event
)
4585 irq_work_sync(&event
->pending
);
4587 unaccount_event(event
);
4589 security_perf_event_free(event
);
4593 * Can happen when we close an event with re-directed output.
4595 * Since we have a 0 refcount, perf_mmap_close() will skip
4596 * over us; possibly making our ring_buffer_put() the last.
4598 mutex_lock(&event
->mmap_mutex
);
4599 ring_buffer_attach(event
, NULL
);
4600 mutex_unlock(&event
->mmap_mutex
);
4603 if (is_cgroup_event(event
))
4604 perf_detach_cgroup(event
);
4606 if (!event
->parent
) {
4607 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4608 put_callchain_buffers();
4611 perf_event_free_bpf_prog(event
);
4612 perf_addr_filters_splice(event
, NULL
);
4613 kfree(event
->addr_filter_ranges
);
4616 event
->destroy(event
);
4619 * Must be after ->destroy(), due to uprobe_perf_close() using
4622 if (event
->hw
.target
)
4623 put_task_struct(event
->hw
.target
);
4626 * perf_event_free_task() relies on put_ctx() being 'last', in particular
4627 * all task references must be cleaned up.
4630 put_ctx(event
->ctx
);
4632 exclusive_event_destroy(event
);
4633 module_put(event
->pmu
->module
);
4635 call_rcu(&event
->rcu_head
, free_event_rcu
);
4639 * Used to free events which have a known refcount of 1, such as in error paths
4640 * where the event isn't exposed yet and inherited events.
4642 static void free_event(struct perf_event
*event
)
4644 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4645 "unexpected event refcount: %ld; ptr=%p\n",
4646 atomic_long_read(&event
->refcount
), event
)) {
4647 /* leak to avoid use-after-free */
4655 * Remove user event from the owner task.
4657 static void perf_remove_from_owner(struct perf_event
*event
)
4659 struct task_struct
*owner
;
4663 * Matches the smp_store_release() in perf_event_exit_task(). If we
4664 * observe !owner it means the list deletion is complete and we can
4665 * indeed free this event, otherwise we need to serialize on
4666 * owner->perf_event_mutex.
4668 owner
= READ_ONCE(event
->owner
);
4671 * Since delayed_put_task_struct() also drops the last
4672 * task reference we can safely take a new reference
4673 * while holding the rcu_read_lock().
4675 get_task_struct(owner
);
4681 * If we're here through perf_event_exit_task() we're already
4682 * holding ctx->mutex which would be an inversion wrt. the
4683 * normal lock order.
4685 * However we can safely take this lock because its the child
4688 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4691 * We have to re-check the event->owner field, if it is cleared
4692 * we raced with perf_event_exit_task(), acquiring the mutex
4693 * ensured they're done, and we can proceed with freeing the
4697 list_del_init(&event
->owner_entry
);
4698 smp_store_release(&event
->owner
, NULL
);
4700 mutex_unlock(&owner
->perf_event_mutex
);
4701 put_task_struct(owner
);
4705 static void put_event(struct perf_event
*event
)
4707 if (!atomic_long_dec_and_test(&event
->refcount
))
4714 * Kill an event dead; while event:refcount will preserve the event
4715 * object, it will not preserve its functionality. Once the last 'user'
4716 * gives up the object, we'll destroy the thing.
4718 int perf_event_release_kernel(struct perf_event
*event
)
4720 struct perf_event_context
*ctx
= event
->ctx
;
4721 struct perf_event
*child
, *tmp
;
4722 LIST_HEAD(free_list
);
4725 * If we got here through err_file: fput(event_file); we will not have
4726 * attached to a context yet.
4729 WARN_ON_ONCE(event
->attach_state
&
4730 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4734 if (!is_kernel_event(event
))
4735 perf_remove_from_owner(event
);
4737 ctx
= perf_event_ctx_lock(event
);
4738 WARN_ON_ONCE(ctx
->parent_ctx
);
4739 perf_remove_from_context(event
, DETACH_GROUP
);
4741 raw_spin_lock_irq(&ctx
->lock
);
4743 * Mark this event as STATE_DEAD, there is no external reference to it
4746 * Anybody acquiring event->child_mutex after the below loop _must_
4747 * also see this, most importantly inherit_event() which will avoid
4748 * placing more children on the list.
4750 * Thus this guarantees that we will in fact observe and kill _ALL_
4753 event
->state
= PERF_EVENT_STATE_DEAD
;
4754 raw_spin_unlock_irq(&ctx
->lock
);
4756 perf_event_ctx_unlock(event
, ctx
);
4759 mutex_lock(&event
->child_mutex
);
4760 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4763 * Cannot change, child events are not migrated, see the
4764 * comment with perf_event_ctx_lock_nested().
4766 ctx
= READ_ONCE(child
->ctx
);
4768 * Since child_mutex nests inside ctx::mutex, we must jump
4769 * through hoops. We start by grabbing a reference on the ctx.
4771 * Since the event cannot get freed while we hold the
4772 * child_mutex, the context must also exist and have a !0
4778 * Now that we have a ctx ref, we can drop child_mutex, and
4779 * acquire ctx::mutex without fear of it going away. Then we
4780 * can re-acquire child_mutex.
4782 mutex_unlock(&event
->child_mutex
);
4783 mutex_lock(&ctx
->mutex
);
4784 mutex_lock(&event
->child_mutex
);
4787 * Now that we hold ctx::mutex and child_mutex, revalidate our
4788 * state, if child is still the first entry, it didn't get freed
4789 * and we can continue doing so.
4791 tmp
= list_first_entry_or_null(&event
->child_list
,
4792 struct perf_event
, child_list
);
4794 perf_remove_from_context(child
, DETACH_GROUP
);
4795 list_move(&child
->child_list
, &free_list
);
4797 * This matches the refcount bump in inherit_event();
4798 * this can't be the last reference.
4803 mutex_unlock(&event
->child_mutex
);
4804 mutex_unlock(&ctx
->mutex
);
4808 mutex_unlock(&event
->child_mutex
);
4810 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4811 void *var
= &child
->ctx
->refcount
;
4813 list_del(&child
->child_list
);
4817 * Wake any perf_event_free_task() waiting for this event to be
4820 smp_mb(); /* pairs with wait_var_event() */
4825 put_event(event
); /* Must be the 'last' reference */
4828 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4831 * Called when the last reference to the file is gone.
4833 static int perf_release(struct inode
*inode
, struct file
*file
)
4835 perf_event_release_kernel(file
->private_data
);
4839 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4841 struct perf_event
*child
;
4847 mutex_lock(&event
->child_mutex
);
4849 (void)perf_event_read(event
, false);
4850 total
+= perf_event_count(event
);
4852 *enabled
+= event
->total_time_enabled
+
4853 atomic64_read(&event
->child_total_time_enabled
);
4854 *running
+= event
->total_time_running
+
4855 atomic64_read(&event
->child_total_time_running
);
4857 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4858 (void)perf_event_read(child
, false);
4859 total
+= perf_event_count(child
);
4860 *enabled
+= child
->total_time_enabled
;
4861 *running
+= child
->total_time_running
;
4863 mutex_unlock(&event
->child_mutex
);
4868 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4870 struct perf_event_context
*ctx
;
4873 ctx
= perf_event_ctx_lock(event
);
4874 count
= __perf_event_read_value(event
, enabled
, running
);
4875 perf_event_ctx_unlock(event
, ctx
);
4879 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4881 static int __perf_read_group_add(struct perf_event
*leader
,
4882 u64 read_format
, u64
*values
)
4884 struct perf_event_context
*ctx
= leader
->ctx
;
4885 struct perf_event
*sub
;
4886 unsigned long flags
;
4887 int n
= 1; /* skip @nr */
4890 ret
= perf_event_read(leader
, true);
4894 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4897 * Since we co-schedule groups, {enabled,running} times of siblings
4898 * will be identical to those of the leader, so we only publish one
4901 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4902 values
[n
++] += leader
->total_time_enabled
+
4903 atomic64_read(&leader
->child_total_time_enabled
);
4906 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4907 values
[n
++] += leader
->total_time_running
+
4908 atomic64_read(&leader
->child_total_time_running
);
4912 * Write {count,id} tuples for every sibling.
4914 values
[n
++] += perf_event_count(leader
);
4915 if (read_format
& PERF_FORMAT_ID
)
4916 values
[n
++] = primary_event_id(leader
);
4918 for_each_sibling_event(sub
, leader
) {
4919 values
[n
++] += perf_event_count(sub
);
4920 if (read_format
& PERF_FORMAT_ID
)
4921 values
[n
++] = primary_event_id(sub
);
4924 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4928 static int perf_read_group(struct perf_event
*event
,
4929 u64 read_format
, char __user
*buf
)
4931 struct perf_event
*leader
= event
->group_leader
, *child
;
4932 struct perf_event_context
*ctx
= leader
->ctx
;
4936 lockdep_assert_held(&ctx
->mutex
);
4938 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4942 values
[0] = 1 + leader
->nr_siblings
;
4945 * By locking the child_mutex of the leader we effectively
4946 * lock the child list of all siblings.. XXX explain how.
4948 mutex_lock(&leader
->child_mutex
);
4950 ret
= __perf_read_group_add(leader
, read_format
, values
);
4954 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4955 ret
= __perf_read_group_add(child
, read_format
, values
);
4960 mutex_unlock(&leader
->child_mutex
);
4962 ret
= event
->read_size
;
4963 if (copy_to_user(buf
, values
, event
->read_size
))
4968 mutex_unlock(&leader
->child_mutex
);
4974 static int perf_read_one(struct perf_event
*event
,
4975 u64 read_format
, char __user
*buf
)
4977 u64 enabled
, running
;
4981 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4982 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4983 values
[n
++] = enabled
;
4984 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4985 values
[n
++] = running
;
4986 if (read_format
& PERF_FORMAT_ID
)
4987 values
[n
++] = primary_event_id(event
);
4989 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4992 return n
* sizeof(u64
);
4995 static bool is_event_hup(struct perf_event
*event
)
4999 if (event
->state
> PERF_EVENT_STATE_EXIT
)
5002 mutex_lock(&event
->child_mutex
);
5003 no_children
= list_empty(&event
->child_list
);
5004 mutex_unlock(&event
->child_mutex
);
5009 * Read the performance event - simple non blocking version for now
5012 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
5014 u64 read_format
= event
->attr
.read_format
;
5018 * Return end-of-file for a read on an event that is in
5019 * error state (i.e. because it was pinned but it couldn't be
5020 * scheduled on to the CPU at some point).
5022 if (event
->state
== PERF_EVENT_STATE_ERROR
)
5025 if (count
< event
->read_size
)
5028 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5029 if (read_format
& PERF_FORMAT_GROUP
)
5030 ret
= perf_read_group(event
, read_format
, buf
);
5032 ret
= perf_read_one(event
, read_format
, buf
);
5038 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
5040 struct perf_event
*event
= file
->private_data
;
5041 struct perf_event_context
*ctx
;
5044 ret
= security_perf_event_read(event
);
5048 ctx
= perf_event_ctx_lock(event
);
5049 ret
= __perf_read(event
, buf
, count
);
5050 perf_event_ctx_unlock(event
, ctx
);
5055 static __poll_t
perf_poll(struct file
*file
, poll_table
*wait
)
5057 struct perf_event
*event
= file
->private_data
;
5058 struct perf_buffer
*rb
;
5059 __poll_t events
= EPOLLHUP
;
5061 poll_wait(file
, &event
->waitq
, wait
);
5063 if (is_event_hup(event
))
5067 * Pin the event->rb by taking event->mmap_mutex; otherwise
5068 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
5070 mutex_lock(&event
->mmap_mutex
);
5073 events
= atomic_xchg(&rb
->poll
, 0);
5074 mutex_unlock(&event
->mmap_mutex
);
5078 static void _perf_event_reset(struct perf_event
*event
)
5080 (void)perf_event_read(event
, false);
5081 local64_set(&event
->count
, 0);
5082 perf_event_update_userpage(event
);
5085 /* Assume it's not an event with inherit set. */
5086 u64
perf_event_pause(struct perf_event
*event
, bool reset
)
5088 struct perf_event_context
*ctx
;
5091 ctx
= perf_event_ctx_lock(event
);
5092 WARN_ON_ONCE(event
->attr
.inherit
);
5093 _perf_event_disable(event
);
5094 count
= local64_read(&event
->count
);
5096 local64_set(&event
->count
, 0);
5097 perf_event_ctx_unlock(event
, ctx
);
5101 EXPORT_SYMBOL_GPL(perf_event_pause
);
5104 * Holding the top-level event's child_mutex means that any
5105 * descendant process that has inherited this event will block
5106 * in perf_event_exit_event() if it goes to exit, thus satisfying the
5107 * task existence requirements of perf_event_enable/disable.
5109 static void perf_event_for_each_child(struct perf_event
*event
,
5110 void (*func
)(struct perf_event
*))
5112 struct perf_event
*child
;
5114 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5116 mutex_lock(&event
->child_mutex
);
5118 list_for_each_entry(child
, &event
->child_list
, child_list
)
5120 mutex_unlock(&event
->child_mutex
);
5123 static void perf_event_for_each(struct perf_event
*event
,
5124 void (*func
)(struct perf_event
*))
5126 struct perf_event_context
*ctx
= event
->ctx
;
5127 struct perf_event
*sibling
;
5129 lockdep_assert_held(&ctx
->mutex
);
5131 event
= event
->group_leader
;
5133 perf_event_for_each_child(event
, func
);
5134 for_each_sibling_event(sibling
, event
)
5135 perf_event_for_each_child(sibling
, func
);
5138 static void __perf_event_period(struct perf_event
*event
,
5139 struct perf_cpu_context
*cpuctx
,
5140 struct perf_event_context
*ctx
,
5143 u64 value
= *((u64
*)info
);
5146 if (event
->attr
.freq
) {
5147 event
->attr
.sample_freq
= value
;
5149 event
->attr
.sample_period
= value
;
5150 event
->hw
.sample_period
= value
;
5153 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
5155 perf_pmu_disable(ctx
->pmu
);
5157 * We could be throttled; unthrottle now to avoid the tick
5158 * trying to unthrottle while we already re-started the event.
5160 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
5161 event
->hw
.interrupts
= 0;
5162 perf_log_throttle(event
, 1);
5164 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
5167 local64_set(&event
->hw
.period_left
, 0);
5170 event
->pmu
->start(event
, PERF_EF_RELOAD
);
5171 perf_pmu_enable(ctx
->pmu
);
5175 static int perf_event_check_period(struct perf_event
*event
, u64 value
)
5177 return event
->pmu
->check_period(event
, value
);
5180 static int _perf_event_period(struct perf_event
*event
, u64 value
)
5182 if (!is_sampling_event(event
))
5188 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
5191 if (perf_event_check_period(event
, value
))
5194 if (!event
->attr
.freq
&& (value
& (1ULL << 63)))
5197 event_function_call(event
, __perf_event_period
, &value
);
5202 int perf_event_period(struct perf_event
*event
, u64 value
)
5204 struct perf_event_context
*ctx
;
5207 ctx
= perf_event_ctx_lock(event
);
5208 ret
= _perf_event_period(event
, value
);
5209 perf_event_ctx_unlock(event
, ctx
);
5213 EXPORT_SYMBOL_GPL(perf_event_period
);
5215 static const struct file_operations perf_fops
;
5217 static inline int perf_fget_light(int fd
, struct fd
*p
)
5219 struct fd f
= fdget(fd
);
5223 if (f
.file
->f_op
!= &perf_fops
) {
5231 static int perf_event_set_output(struct perf_event
*event
,
5232 struct perf_event
*output_event
);
5233 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
5234 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
5235 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5236 struct perf_event_attr
*attr
);
5238 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
5240 void (*func
)(struct perf_event
*);
5244 case PERF_EVENT_IOC_ENABLE
:
5245 func
= _perf_event_enable
;
5247 case PERF_EVENT_IOC_DISABLE
:
5248 func
= _perf_event_disable
;
5250 case PERF_EVENT_IOC_RESET
:
5251 func
= _perf_event_reset
;
5254 case PERF_EVENT_IOC_REFRESH
:
5255 return _perf_event_refresh(event
, arg
);
5257 case PERF_EVENT_IOC_PERIOD
:
5261 if (copy_from_user(&value
, (u64 __user
*)arg
, sizeof(value
)))
5264 return _perf_event_period(event
, value
);
5266 case PERF_EVENT_IOC_ID
:
5268 u64 id
= primary_event_id(event
);
5270 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
5275 case PERF_EVENT_IOC_SET_OUTPUT
:
5279 struct perf_event
*output_event
;
5281 ret
= perf_fget_light(arg
, &output
);
5284 output_event
= output
.file
->private_data
;
5285 ret
= perf_event_set_output(event
, output_event
);
5288 ret
= perf_event_set_output(event
, NULL
);
5293 case PERF_EVENT_IOC_SET_FILTER
:
5294 return perf_event_set_filter(event
, (void __user
*)arg
);
5296 case PERF_EVENT_IOC_SET_BPF
:
5297 return perf_event_set_bpf_prog(event
, arg
);
5299 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
5300 struct perf_buffer
*rb
;
5303 rb
= rcu_dereference(event
->rb
);
5304 if (!rb
|| !rb
->nr_pages
) {
5308 rb_toggle_paused(rb
, !!arg
);
5313 case PERF_EVENT_IOC_QUERY_BPF
:
5314 return perf_event_query_prog_array(event
, (void __user
*)arg
);
5316 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES
: {
5317 struct perf_event_attr new_attr
;
5318 int err
= perf_copy_attr((struct perf_event_attr __user
*)arg
,
5324 return perf_event_modify_attr(event
, &new_attr
);
5330 if (flags
& PERF_IOC_FLAG_GROUP
)
5331 perf_event_for_each(event
, func
);
5333 perf_event_for_each_child(event
, func
);
5338 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
5340 struct perf_event
*event
= file
->private_data
;
5341 struct perf_event_context
*ctx
;
5344 /* Treat ioctl like writes as it is likely a mutating operation. */
5345 ret
= security_perf_event_write(event
);
5349 ctx
= perf_event_ctx_lock(event
);
5350 ret
= _perf_ioctl(event
, cmd
, arg
);
5351 perf_event_ctx_unlock(event
, ctx
);
5356 #ifdef CONFIG_COMPAT
5357 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
5360 switch (_IOC_NR(cmd
)) {
5361 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
5362 case _IOC_NR(PERF_EVENT_IOC_ID
):
5363 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF
):
5364 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES
):
5365 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5366 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
5367 cmd
&= ~IOCSIZE_MASK
;
5368 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
5372 return perf_ioctl(file
, cmd
, arg
);
5375 # define perf_compat_ioctl NULL
5378 int perf_event_task_enable(void)
5380 struct perf_event_context
*ctx
;
5381 struct perf_event
*event
;
5383 mutex_lock(¤t
->perf_event_mutex
);
5384 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5385 ctx
= perf_event_ctx_lock(event
);
5386 perf_event_for_each_child(event
, _perf_event_enable
);
5387 perf_event_ctx_unlock(event
, ctx
);
5389 mutex_unlock(¤t
->perf_event_mutex
);
5394 int perf_event_task_disable(void)
5396 struct perf_event_context
*ctx
;
5397 struct perf_event
*event
;
5399 mutex_lock(¤t
->perf_event_mutex
);
5400 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5401 ctx
= perf_event_ctx_lock(event
);
5402 perf_event_for_each_child(event
, _perf_event_disable
);
5403 perf_event_ctx_unlock(event
, ctx
);
5405 mutex_unlock(¤t
->perf_event_mutex
);
5410 static int perf_event_index(struct perf_event
*event
)
5412 if (event
->hw
.state
& PERF_HES_STOPPED
)
5415 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5418 return event
->pmu
->event_idx(event
);
5421 static void calc_timer_values(struct perf_event
*event
,
5428 *now
= perf_clock();
5429 ctx_time
= event
->shadow_ctx_time
+ *now
;
5430 __perf_update_times(event
, ctx_time
, enabled
, running
);
5433 static void perf_event_init_userpage(struct perf_event
*event
)
5435 struct perf_event_mmap_page
*userpg
;
5436 struct perf_buffer
*rb
;
5439 rb
= rcu_dereference(event
->rb
);
5443 userpg
= rb
->user_page
;
5445 /* Allow new userspace to detect that bit 0 is deprecated */
5446 userpg
->cap_bit0_is_deprecated
= 1;
5447 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
5448 userpg
->data_offset
= PAGE_SIZE
;
5449 userpg
->data_size
= perf_data_size(rb
);
5455 void __weak
arch_perf_update_userpage(
5456 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
5461 * Callers need to ensure there can be no nesting of this function, otherwise
5462 * the seqlock logic goes bad. We can not serialize this because the arch
5463 * code calls this from NMI context.
5465 void perf_event_update_userpage(struct perf_event
*event
)
5467 struct perf_event_mmap_page
*userpg
;
5468 struct perf_buffer
*rb
;
5469 u64 enabled
, running
, now
;
5472 rb
= rcu_dereference(event
->rb
);
5477 * compute total_time_enabled, total_time_running
5478 * based on snapshot values taken when the event
5479 * was last scheduled in.
5481 * we cannot simply called update_context_time()
5482 * because of locking issue as we can be called in
5485 calc_timer_values(event
, &now
, &enabled
, &running
);
5487 userpg
= rb
->user_page
;
5489 * Disable preemption to guarantee consistent time stamps are stored to
5495 userpg
->index
= perf_event_index(event
);
5496 userpg
->offset
= perf_event_count(event
);
5498 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5500 userpg
->time_enabled
= enabled
+
5501 atomic64_read(&event
->child_total_time_enabled
);
5503 userpg
->time_running
= running
+
5504 atomic64_read(&event
->child_total_time_running
);
5506 arch_perf_update_userpage(event
, userpg
, now
);
5514 EXPORT_SYMBOL_GPL(perf_event_update_userpage
);
5516 static vm_fault_t
perf_mmap_fault(struct vm_fault
*vmf
)
5518 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5519 struct perf_buffer
*rb
;
5520 vm_fault_t ret
= VM_FAULT_SIGBUS
;
5522 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5523 if (vmf
->pgoff
== 0)
5529 rb
= rcu_dereference(event
->rb
);
5533 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5536 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5540 get_page(vmf
->page
);
5541 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5542 vmf
->page
->index
= vmf
->pgoff
;
5551 static void ring_buffer_attach(struct perf_event
*event
,
5552 struct perf_buffer
*rb
)
5554 struct perf_buffer
*old_rb
= NULL
;
5555 unsigned long flags
;
5559 * Should be impossible, we set this when removing
5560 * event->rb_entry and wait/clear when adding event->rb_entry.
5562 WARN_ON_ONCE(event
->rcu_pending
);
5565 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5566 list_del_rcu(&event
->rb_entry
);
5567 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5569 event
->rcu_batches
= get_state_synchronize_rcu();
5570 event
->rcu_pending
= 1;
5574 if (event
->rcu_pending
) {
5575 cond_synchronize_rcu(event
->rcu_batches
);
5576 event
->rcu_pending
= 0;
5579 spin_lock_irqsave(&rb
->event_lock
, flags
);
5580 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5581 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5585 * Avoid racing with perf_mmap_close(AUX): stop the event
5586 * before swizzling the event::rb pointer; if it's getting
5587 * unmapped, its aux_mmap_count will be 0 and it won't
5588 * restart. See the comment in __perf_pmu_output_stop().
5590 * Data will inevitably be lost when set_output is done in
5591 * mid-air, but then again, whoever does it like this is
5592 * not in for the data anyway.
5595 perf_event_stop(event
, 0);
5597 rcu_assign_pointer(event
->rb
, rb
);
5600 ring_buffer_put(old_rb
);
5602 * Since we detached before setting the new rb, so that we
5603 * could attach the new rb, we could have missed a wakeup.
5606 wake_up_all(&event
->waitq
);
5610 static void ring_buffer_wakeup(struct perf_event
*event
)
5612 struct perf_buffer
*rb
;
5615 rb
= rcu_dereference(event
->rb
);
5617 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5618 wake_up_all(&event
->waitq
);
5623 struct perf_buffer
*ring_buffer_get(struct perf_event
*event
)
5625 struct perf_buffer
*rb
;
5628 rb
= rcu_dereference(event
->rb
);
5630 if (!refcount_inc_not_zero(&rb
->refcount
))
5638 void ring_buffer_put(struct perf_buffer
*rb
)
5640 if (!refcount_dec_and_test(&rb
->refcount
))
5643 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5645 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5648 static void perf_mmap_open(struct vm_area_struct
*vma
)
5650 struct perf_event
*event
= vma
->vm_file
->private_data
;
5652 atomic_inc(&event
->mmap_count
);
5653 atomic_inc(&event
->rb
->mmap_count
);
5656 atomic_inc(&event
->rb
->aux_mmap_count
);
5658 if (event
->pmu
->event_mapped
)
5659 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5662 static void perf_pmu_output_stop(struct perf_event
*event
);
5665 * A buffer can be mmap()ed multiple times; either directly through the same
5666 * event, or through other events by use of perf_event_set_output().
5668 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5669 * the buffer here, where we still have a VM context. This means we need
5670 * to detach all events redirecting to us.
5672 static void perf_mmap_close(struct vm_area_struct
*vma
)
5674 struct perf_event
*event
= vma
->vm_file
->private_data
;
5676 struct perf_buffer
*rb
= ring_buffer_get(event
);
5677 struct user_struct
*mmap_user
= rb
->mmap_user
;
5678 int mmap_locked
= rb
->mmap_locked
;
5679 unsigned long size
= perf_data_size(rb
);
5681 if (event
->pmu
->event_unmapped
)
5682 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5685 * rb->aux_mmap_count will always drop before rb->mmap_count and
5686 * event->mmap_count, so it is ok to use event->mmap_mutex to
5687 * serialize with perf_mmap here.
5689 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5690 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5692 * Stop all AUX events that are writing to this buffer,
5693 * so that we can free its AUX pages and corresponding PMU
5694 * data. Note that after rb::aux_mmap_count dropped to zero,
5695 * they won't start any more (see perf_aux_output_begin()).
5697 perf_pmu_output_stop(event
);
5699 /* now it's safe to free the pages */
5700 atomic_long_sub(rb
->aux_nr_pages
- rb
->aux_mmap_locked
, &mmap_user
->locked_vm
);
5701 atomic64_sub(rb
->aux_mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5703 /* this has to be the last one */
5705 WARN_ON_ONCE(refcount_read(&rb
->aux_refcount
));
5707 mutex_unlock(&event
->mmap_mutex
);
5710 atomic_dec(&rb
->mmap_count
);
5712 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5715 ring_buffer_attach(event
, NULL
);
5716 mutex_unlock(&event
->mmap_mutex
);
5718 /* If there's still other mmap()s of this buffer, we're done. */
5719 if (atomic_read(&rb
->mmap_count
))
5723 * No other mmap()s, detach from all other events that might redirect
5724 * into the now unreachable buffer. Somewhat complicated by the
5725 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5729 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5730 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5732 * This event is en-route to free_event() which will
5733 * detach it and remove it from the list.
5739 mutex_lock(&event
->mmap_mutex
);
5741 * Check we didn't race with perf_event_set_output() which can
5742 * swizzle the rb from under us while we were waiting to
5743 * acquire mmap_mutex.
5745 * If we find a different rb; ignore this event, a next
5746 * iteration will no longer find it on the list. We have to
5747 * still restart the iteration to make sure we're not now
5748 * iterating the wrong list.
5750 if (event
->rb
== rb
)
5751 ring_buffer_attach(event
, NULL
);
5753 mutex_unlock(&event
->mmap_mutex
);
5757 * Restart the iteration; either we're on the wrong list or
5758 * destroyed its integrity by doing a deletion.
5765 * It could be there's still a few 0-ref events on the list; they'll
5766 * get cleaned up by free_event() -- they'll also still have their
5767 * ref on the rb and will free it whenever they are done with it.
5769 * Aside from that, this buffer is 'fully' detached and unmapped,
5770 * undo the VM accounting.
5773 atomic_long_sub((size
>> PAGE_SHIFT
) + 1 - mmap_locked
,
5774 &mmap_user
->locked_vm
);
5775 atomic64_sub(mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5776 free_uid(mmap_user
);
5779 ring_buffer_put(rb
); /* could be last */
5782 static const struct vm_operations_struct perf_mmap_vmops
= {
5783 .open
= perf_mmap_open
,
5784 .close
= perf_mmap_close
, /* non mergeable */
5785 .fault
= perf_mmap_fault
,
5786 .page_mkwrite
= perf_mmap_fault
,
5789 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5791 struct perf_event
*event
= file
->private_data
;
5792 unsigned long user_locked
, user_lock_limit
;
5793 struct user_struct
*user
= current_user();
5794 struct perf_buffer
*rb
= NULL
;
5795 unsigned long locked
, lock_limit
;
5796 unsigned long vma_size
;
5797 unsigned long nr_pages
;
5798 long user_extra
= 0, extra
= 0;
5799 int ret
= 0, flags
= 0;
5802 * Don't allow mmap() of inherited per-task counters. This would
5803 * create a performance issue due to all children writing to the
5806 if (event
->cpu
== -1 && event
->attr
.inherit
)
5809 if (!(vma
->vm_flags
& VM_SHARED
))
5812 ret
= security_perf_event_read(event
);
5816 vma_size
= vma
->vm_end
- vma
->vm_start
;
5818 if (vma
->vm_pgoff
== 0) {
5819 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5822 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5823 * mapped, all subsequent mappings should have the same size
5824 * and offset. Must be above the normal perf buffer.
5826 u64 aux_offset
, aux_size
;
5831 nr_pages
= vma_size
/ PAGE_SIZE
;
5833 mutex_lock(&event
->mmap_mutex
);
5840 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5841 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5843 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5846 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5849 /* already mapped with a different offset */
5850 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5853 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5856 /* already mapped with a different size */
5857 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5860 if (!is_power_of_2(nr_pages
))
5863 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5866 if (rb_has_aux(rb
)) {
5867 atomic_inc(&rb
->aux_mmap_count
);
5872 atomic_set(&rb
->aux_mmap_count
, 1);
5873 user_extra
= nr_pages
;
5879 * If we have rb pages ensure they're a power-of-two number, so we
5880 * can do bitmasks instead of modulo.
5882 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5885 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5888 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5890 mutex_lock(&event
->mmap_mutex
);
5892 if (event
->rb
->nr_pages
!= nr_pages
) {
5897 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5899 * Raced against perf_mmap_close() through
5900 * perf_event_set_output(). Try again, hope for better
5903 mutex_unlock(&event
->mmap_mutex
);
5910 user_extra
= nr_pages
+ 1;
5913 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5916 * Increase the limit linearly with more CPUs:
5918 user_lock_limit
*= num_online_cpus();
5920 user_locked
= atomic_long_read(&user
->locked_vm
);
5923 * sysctl_perf_event_mlock may have changed, so that
5924 * user->locked_vm > user_lock_limit
5926 if (user_locked
> user_lock_limit
)
5927 user_locked
= user_lock_limit
;
5928 user_locked
+= user_extra
;
5930 if (user_locked
> user_lock_limit
) {
5932 * charge locked_vm until it hits user_lock_limit;
5933 * charge the rest from pinned_vm
5935 extra
= user_locked
- user_lock_limit
;
5936 user_extra
-= extra
;
5939 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5940 lock_limit
>>= PAGE_SHIFT
;
5941 locked
= atomic64_read(&vma
->vm_mm
->pinned_vm
) + extra
;
5943 if ((locked
> lock_limit
) && perf_is_paranoid() &&
5944 !capable(CAP_IPC_LOCK
)) {
5949 WARN_ON(!rb
&& event
->rb
);
5951 if (vma
->vm_flags
& VM_WRITE
)
5952 flags
|= RING_BUFFER_WRITABLE
;
5955 rb
= rb_alloc(nr_pages
,
5956 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5964 atomic_set(&rb
->mmap_count
, 1);
5965 rb
->mmap_user
= get_current_user();
5966 rb
->mmap_locked
= extra
;
5968 ring_buffer_attach(event
, rb
);
5970 perf_event_init_userpage(event
);
5971 perf_event_update_userpage(event
);
5973 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5974 event
->attr
.aux_watermark
, flags
);
5976 rb
->aux_mmap_locked
= extra
;
5981 atomic_long_add(user_extra
, &user
->locked_vm
);
5982 atomic64_add(extra
, &vma
->vm_mm
->pinned_vm
);
5984 atomic_inc(&event
->mmap_count
);
5986 atomic_dec(&rb
->mmap_count
);
5989 mutex_unlock(&event
->mmap_mutex
);
5992 * Since pinned accounting is per vm we cannot allow fork() to copy our
5995 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5996 vma
->vm_ops
= &perf_mmap_vmops
;
5998 if (event
->pmu
->event_mapped
)
5999 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
6004 static int perf_fasync(int fd
, struct file
*filp
, int on
)
6006 struct inode
*inode
= file_inode(filp
);
6007 struct perf_event
*event
= filp
->private_data
;
6011 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
6012 inode_unlock(inode
);
6020 static const struct file_operations perf_fops
= {
6021 .llseek
= no_llseek
,
6022 .release
= perf_release
,
6025 .unlocked_ioctl
= perf_ioctl
,
6026 .compat_ioctl
= perf_compat_ioctl
,
6028 .fasync
= perf_fasync
,
6034 * If there's data, ensure we set the poll() state and publish everything
6035 * to user-space before waking everybody up.
6038 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
6040 /* only the parent has fasync state */
6042 event
= event
->parent
;
6043 return &event
->fasync
;
6046 void perf_event_wakeup(struct perf_event
*event
)
6048 ring_buffer_wakeup(event
);
6050 if (event
->pending_kill
) {
6051 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
6052 event
->pending_kill
= 0;
6056 static void perf_pending_event_disable(struct perf_event
*event
)
6058 int cpu
= READ_ONCE(event
->pending_disable
);
6063 if (cpu
== smp_processor_id()) {
6064 WRITE_ONCE(event
->pending_disable
, -1);
6065 perf_event_disable_local(event
);
6072 * perf_event_disable_inatomic()
6073 * @pending_disable = CPU-A;
6077 * @pending_disable = -1;
6080 * perf_event_disable_inatomic()
6081 * @pending_disable = CPU-B;
6082 * irq_work_queue(); // FAILS
6085 * perf_pending_event()
6087 * But the event runs on CPU-B and wants disabling there.
6089 irq_work_queue_on(&event
->pending
, cpu
);
6092 static void perf_pending_event(struct irq_work
*entry
)
6094 struct perf_event
*event
= container_of(entry
, struct perf_event
, pending
);
6097 rctx
= perf_swevent_get_recursion_context();
6099 * If we 'fail' here, that's OK, it means recursion is already disabled
6100 * and we won't recurse 'further'.
6103 perf_pending_event_disable(event
);
6105 if (event
->pending_wakeup
) {
6106 event
->pending_wakeup
= 0;
6107 perf_event_wakeup(event
);
6111 perf_swevent_put_recursion_context(rctx
);
6115 * We assume there is only KVM supporting the callbacks.
6116 * Later on, we might change it to a list if there is
6117 * another virtualization implementation supporting the callbacks.
6119 struct perf_guest_info_callbacks
*perf_guest_cbs
;
6121 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6123 perf_guest_cbs
= cbs
;
6126 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
6128 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6130 perf_guest_cbs
= NULL
;
6133 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
6136 perf_output_sample_regs(struct perf_output_handle
*handle
,
6137 struct pt_regs
*regs
, u64 mask
)
6140 DECLARE_BITMAP(_mask
, 64);
6142 bitmap_from_u64(_mask
, mask
);
6143 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
6146 val
= perf_reg_value(regs
, bit
);
6147 perf_output_put(handle
, val
);
6151 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
6152 struct pt_regs
*regs
,
6153 struct pt_regs
*regs_user_copy
)
6155 if (user_mode(regs
)) {
6156 regs_user
->abi
= perf_reg_abi(current
);
6157 regs_user
->regs
= regs
;
6158 } else if (!(current
->flags
& PF_KTHREAD
)) {
6159 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
6161 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
6162 regs_user
->regs
= NULL
;
6166 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
6167 struct pt_regs
*regs
)
6169 regs_intr
->regs
= regs
;
6170 regs_intr
->abi
= perf_reg_abi(current
);
6175 * Get remaining task size from user stack pointer.
6177 * It'd be better to take stack vma map and limit this more
6178 * precisely, but there's no way to get it safely under interrupt,
6179 * so using TASK_SIZE as limit.
6181 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
6183 unsigned long addr
= perf_user_stack_pointer(regs
);
6185 if (!addr
|| addr
>= TASK_SIZE
)
6188 return TASK_SIZE
- addr
;
6192 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
6193 struct pt_regs
*regs
)
6197 /* No regs, no stack pointer, no dump. */
6202 * Check if we fit in with the requested stack size into the:
6204 * If we don't, we limit the size to the TASK_SIZE.
6206 * - remaining sample size
6207 * If we don't, we customize the stack size to
6208 * fit in to the remaining sample size.
6211 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
6212 stack_size
= min(stack_size
, (u16
) task_size
);
6214 /* Current header size plus static size and dynamic size. */
6215 header_size
+= 2 * sizeof(u64
);
6217 /* Do we fit in with the current stack dump size? */
6218 if ((u16
) (header_size
+ stack_size
) < header_size
) {
6220 * If we overflow the maximum size for the sample,
6221 * we customize the stack dump size to fit in.
6223 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
6224 stack_size
= round_up(stack_size
, sizeof(u64
));
6231 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
6232 struct pt_regs
*regs
)
6234 /* Case of a kernel thread, nothing to dump */
6237 perf_output_put(handle
, size
);
6247 * - the size requested by user or the best one we can fit
6248 * in to the sample max size
6250 * - user stack dump data
6252 * - the actual dumped size
6256 perf_output_put(handle
, dump_size
);
6259 sp
= perf_user_stack_pointer(regs
);
6262 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
6264 dyn_size
= dump_size
- rem
;
6266 perf_output_skip(handle
, rem
);
6269 perf_output_put(handle
, dyn_size
);
6273 static unsigned long perf_prepare_sample_aux(struct perf_event
*event
,
6274 struct perf_sample_data
*data
,
6277 struct perf_event
*sampler
= event
->aux_event
;
6278 struct perf_buffer
*rb
;
6285 if (WARN_ON_ONCE(READ_ONCE(sampler
->state
) != PERF_EVENT_STATE_ACTIVE
))
6288 if (WARN_ON_ONCE(READ_ONCE(sampler
->oncpu
) != smp_processor_id()))
6291 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6296 * If this is an NMI hit inside sampling code, don't take
6297 * the sample. See also perf_aux_sample_output().
6299 if (READ_ONCE(rb
->aux_in_sampling
)) {
6302 size
= min_t(size_t, size
, perf_aux_size(rb
));
6303 data
->aux_size
= ALIGN(size
, sizeof(u64
));
6305 ring_buffer_put(rb
);
6308 return data
->aux_size
;
6311 long perf_pmu_snapshot_aux(struct perf_buffer
*rb
,
6312 struct perf_event
*event
,
6313 struct perf_output_handle
*handle
,
6316 unsigned long flags
;
6320 * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
6321 * paths. If we start calling them in NMI context, they may race with
6322 * the IRQ ones, that is, for example, re-starting an event that's just
6323 * been stopped, which is why we're using a separate callback that
6324 * doesn't change the event state.
6326 * IRQs need to be disabled to prevent IPIs from racing with us.
6328 local_irq_save(flags
);
6330 * Guard against NMI hits inside the critical section;
6331 * see also perf_prepare_sample_aux().
6333 WRITE_ONCE(rb
->aux_in_sampling
, 1);
6336 ret
= event
->pmu
->snapshot_aux(event
, handle
, size
);
6339 WRITE_ONCE(rb
->aux_in_sampling
, 0);
6340 local_irq_restore(flags
);
6345 static void perf_aux_sample_output(struct perf_event
*event
,
6346 struct perf_output_handle
*handle
,
6347 struct perf_sample_data
*data
)
6349 struct perf_event
*sampler
= event
->aux_event
;
6350 struct perf_buffer
*rb
;
6354 if (WARN_ON_ONCE(!sampler
|| !data
->aux_size
))
6357 rb
= ring_buffer_get(sampler
->parent
? sampler
->parent
: sampler
);
6361 size
= perf_pmu_snapshot_aux(rb
, sampler
, handle
, data
->aux_size
);
6364 * An error here means that perf_output_copy() failed (returned a
6365 * non-zero surplus that it didn't copy), which in its current
6366 * enlightened implementation is not possible. If that changes, we'd
6369 if (WARN_ON_ONCE(size
< 0))
6373 * The pad comes from ALIGN()ing data->aux_size up to u64 in
6374 * perf_prepare_sample_aux(), so should not be more than that.
6376 pad
= data
->aux_size
- size
;
6377 if (WARN_ON_ONCE(pad
>= sizeof(u64
)))
6382 perf_output_copy(handle
, &zero
, pad
);
6386 ring_buffer_put(rb
);
6389 static void __perf_event_header__init_id(struct perf_event_header
*header
,
6390 struct perf_sample_data
*data
,
6391 struct perf_event
*event
)
6393 u64 sample_type
= event
->attr
.sample_type
;
6395 data
->type
= sample_type
;
6396 header
->size
+= event
->id_header_size
;
6398 if (sample_type
& PERF_SAMPLE_TID
) {
6399 /* namespace issues */
6400 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
6401 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
6404 if (sample_type
& PERF_SAMPLE_TIME
)
6405 data
->time
= perf_event_clock(event
);
6407 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
6408 data
->id
= primary_event_id(event
);
6410 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6411 data
->stream_id
= event
->id
;
6413 if (sample_type
& PERF_SAMPLE_CPU
) {
6414 data
->cpu_entry
.cpu
= raw_smp_processor_id();
6415 data
->cpu_entry
.reserved
= 0;
6419 void perf_event_header__init_id(struct perf_event_header
*header
,
6420 struct perf_sample_data
*data
,
6421 struct perf_event
*event
)
6423 if (event
->attr
.sample_id_all
)
6424 __perf_event_header__init_id(header
, data
, event
);
6427 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
6428 struct perf_sample_data
*data
)
6430 u64 sample_type
= data
->type
;
6432 if (sample_type
& PERF_SAMPLE_TID
)
6433 perf_output_put(handle
, data
->tid_entry
);
6435 if (sample_type
& PERF_SAMPLE_TIME
)
6436 perf_output_put(handle
, data
->time
);
6438 if (sample_type
& PERF_SAMPLE_ID
)
6439 perf_output_put(handle
, data
->id
);
6441 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6442 perf_output_put(handle
, data
->stream_id
);
6444 if (sample_type
& PERF_SAMPLE_CPU
)
6445 perf_output_put(handle
, data
->cpu_entry
);
6447 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6448 perf_output_put(handle
, data
->id
);
6451 void perf_event__output_id_sample(struct perf_event
*event
,
6452 struct perf_output_handle
*handle
,
6453 struct perf_sample_data
*sample
)
6455 if (event
->attr
.sample_id_all
)
6456 __perf_event__output_id_sample(handle
, sample
);
6459 static void perf_output_read_one(struct perf_output_handle
*handle
,
6460 struct perf_event
*event
,
6461 u64 enabled
, u64 running
)
6463 u64 read_format
= event
->attr
.read_format
;
6467 values
[n
++] = perf_event_count(event
);
6468 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
6469 values
[n
++] = enabled
+
6470 atomic64_read(&event
->child_total_time_enabled
);
6472 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
6473 values
[n
++] = running
+
6474 atomic64_read(&event
->child_total_time_running
);
6476 if (read_format
& PERF_FORMAT_ID
)
6477 values
[n
++] = primary_event_id(event
);
6479 __output_copy(handle
, values
, n
* sizeof(u64
));
6482 static void perf_output_read_group(struct perf_output_handle
*handle
,
6483 struct perf_event
*event
,
6484 u64 enabled
, u64 running
)
6486 struct perf_event
*leader
= event
->group_leader
, *sub
;
6487 u64 read_format
= event
->attr
.read_format
;
6491 values
[n
++] = 1 + leader
->nr_siblings
;
6493 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
6494 values
[n
++] = enabled
;
6496 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
6497 values
[n
++] = running
;
6499 if ((leader
!= event
) &&
6500 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
6501 leader
->pmu
->read(leader
);
6503 values
[n
++] = perf_event_count(leader
);
6504 if (read_format
& PERF_FORMAT_ID
)
6505 values
[n
++] = primary_event_id(leader
);
6507 __output_copy(handle
, values
, n
* sizeof(u64
));
6509 for_each_sibling_event(sub
, leader
) {
6512 if ((sub
!= event
) &&
6513 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
6514 sub
->pmu
->read(sub
);
6516 values
[n
++] = perf_event_count(sub
);
6517 if (read_format
& PERF_FORMAT_ID
)
6518 values
[n
++] = primary_event_id(sub
);
6520 __output_copy(handle
, values
, n
* sizeof(u64
));
6524 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
6525 PERF_FORMAT_TOTAL_TIME_RUNNING)
6528 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
6530 * The problem is that its both hard and excessively expensive to iterate the
6531 * child list, not to mention that its impossible to IPI the children running
6532 * on another CPU, from interrupt/NMI context.
6534 static void perf_output_read(struct perf_output_handle
*handle
,
6535 struct perf_event
*event
)
6537 u64 enabled
= 0, running
= 0, now
;
6538 u64 read_format
= event
->attr
.read_format
;
6541 * compute total_time_enabled, total_time_running
6542 * based on snapshot values taken when the event
6543 * was last scheduled in.
6545 * we cannot simply called update_context_time()
6546 * because of locking issue as we are called in
6549 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
6550 calc_timer_values(event
, &now
, &enabled
, &running
);
6552 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
6553 perf_output_read_group(handle
, event
, enabled
, running
);
6555 perf_output_read_one(handle
, event
, enabled
, running
);
6558 void perf_output_sample(struct perf_output_handle
*handle
,
6559 struct perf_event_header
*header
,
6560 struct perf_sample_data
*data
,
6561 struct perf_event
*event
)
6563 u64 sample_type
= data
->type
;
6565 perf_output_put(handle
, *header
);
6567 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6568 perf_output_put(handle
, data
->id
);
6570 if (sample_type
& PERF_SAMPLE_IP
)
6571 perf_output_put(handle
, data
->ip
);
6573 if (sample_type
& PERF_SAMPLE_TID
)
6574 perf_output_put(handle
, data
->tid_entry
);
6576 if (sample_type
& PERF_SAMPLE_TIME
)
6577 perf_output_put(handle
, data
->time
);
6579 if (sample_type
& PERF_SAMPLE_ADDR
)
6580 perf_output_put(handle
, data
->addr
);
6582 if (sample_type
& PERF_SAMPLE_ID
)
6583 perf_output_put(handle
, data
->id
);
6585 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6586 perf_output_put(handle
, data
->stream_id
);
6588 if (sample_type
& PERF_SAMPLE_CPU
)
6589 perf_output_put(handle
, data
->cpu_entry
);
6591 if (sample_type
& PERF_SAMPLE_PERIOD
)
6592 perf_output_put(handle
, data
->period
);
6594 if (sample_type
& PERF_SAMPLE_READ
)
6595 perf_output_read(handle
, event
);
6597 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6600 size
+= data
->callchain
->nr
;
6601 size
*= sizeof(u64
);
6602 __output_copy(handle
, data
->callchain
, size
);
6605 if (sample_type
& PERF_SAMPLE_RAW
) {
6606 struct perf_raw_record
*raw
= data
->raw
;
6609 struct perf_raw_frag
*frag
= &raw
->frag
;
6611 perf_output_put(handle
, raw
->size
);
6614 __output_custom(handle
, frag
->copy
,
6615 frag
->data
, frag
->size
);
6617 __output_copy(handle
, frag
->data
,
6620 if (perf_raw_frag_last(frag
))
6625 __output_skip(handle
, NULL
, frag
->pad
);
6631 .size
= sizeof(u32
),
6634 perf_output_put(handle
, raw
);
6638 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6639 if (data
->br_stack
) {
6642 size
= data
->br_stack
->nr
6643 * sizeof(struct perf_branch_entry
);
6645 perf_output_put(handle
, data
->br_stack
->nr
);
6646 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
6649 * we always store at least the value of nr
6652 perf_output_put(handle
, nr
);
6656 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6657 u64 abi
= data
->regs_user
.abi
;
6660 * If there are no regs to dump, notice it through
6661 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6663 perf_output_put(handle
, abi
);
6666 u64 mask
= event
->attr
.sample_regs_user
;
6667 perf_output_sample_regs(handle
,
6668 data
->regs_user
.regs
,
6673 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6674 perf_output_sample_ustack(handle
,
6675 data
->stack_user_size
,
6676 data
->regs_user
.regs
);
6679 if (sample_type
& PERF_SAMPLE_WEIGHT
)
6680 perf_output_put(handle
, data
->weight
);
6682 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6683 perf_output_put(handle
, data
->data_src
.val
);
6685 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6686 perf_output_put(handle
, data
->txn
);
6688 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6689 u64 abi
= data
->regs_intr
.abi
;
6691 * If there are no regs to dump, notice it through
6692 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6694 perf_output_put(handle
, abi
);
6697 u64 mask
= event
->attr
.sample_regs_intr
;
6699 perf_output_sample_regs(handle
,
6700 data
->regs_intr
.regs
,
6705 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6706 perf_output_put(handle
, data
->phys_addr
);
6708 if (sample_type
& PERF_SAMPLE_AUX
) {
6709 perf_output_put(handle
, data
->aux_size
);
6712 perf_aux_sample_output(event
, handle
, data
);
6715 if (!event
->attr
.watermark
) {
6716 int wakeup_events
= event
->attr
.wakeup_events
;
6718 if (wakeup_events
) {
6719 struct perf_buffer
*rb
= handle
->rb
;
6720 int events
= local_inc_return(&rb
->events
);
6722 if (events
>= wakeup_events
) {
6723 local_sub(wakeup_events
, &rb
->events
);
6724 local_inc(&rb
->wakeup
);
6730 static u64
perf_virt_to_phys(u64 virt
)
6733 struct page
*p
= NULL
;
6738 if (virt
>= TASK_SIZE
) {
6739 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6740 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6741 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6742 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6745 * Walking the pages tables for user address.
6746 * Interrupts are disabled, so it prevents any tear down
6747 * of the page tables.
6748 * Try IRQ-safe __get_user_pages_fast first.
6749 * If failed, leave phys_addr as 0.
6751 if ((current
->mm
!= NULL
) &&
6752 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6753 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6762 static struct perf_callchain_entry __empty_callchain
= { .nr
= 0, };
6764 struct perf_callchain_entry
*
6765 perf_callchain(struct perf_event
*event
, struct pt_regs
*regs
)
6767 bool kernel
= !event
->attr
.exclude_callchain_kernel
;
6768 bool user
= !event
->attr
.exclude_callchain_user
;
6769 /* Disallow cross-task user callchains. */
6770 bool crosstask
= event
->ctx
->task
&& event
->ctx
->task
!= current
;
6771 const u32 max_stack
= event
->attr
.sample_max_stack
;
6772 struct perf_callchain_entry
*callchain
;
6774 if (!kernel
&& !user
)
6775 return &__empty_callchain
;
6777 callchain
= get_perf_callchain(regs
, 0, kernel
, user
,
6778 max_stack
, crosstask
, true);
6779 return callchain
?: &__empty_callchain
;
6782 void perf_prepare_sample(struct perf_event_header
*header
,
6783 struct perf_sample_data
*data
,
6784 struct perf_event
*event
,
6785 struct pt_regs
*regs
)
6787 u64 sample_type
= event
->attr
.sample_type
;
6789 header
->type
= PERF_RECORD_SAMPLE
;
6790 header
->size
= sizeof(*header
) + event
->header_size
;
6793 header
->misc
|= perf_misc_flags(regs
);
6795 __perf_event_header__init_id(header
, data
, event
);
6797 if (sample_type
& PERF_SAMPLE_IP
)
6798 data
->ip
= perf_instruction_pointer(regs
);
6800 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6803 if (!(sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
))
6804 data
->callchain
= perf_callchain(event
, regs
);
6806 size
+= data
->callchain
->nr
;
6808 header
->size
+= size
* sizeof(u64
);
6811 if (sample_type
& PERF_SAMPLE_RAW
) {
6812 struct perf_raw_record
*raw
= data
->raw
;
6816 struct perf_raw_frag
*frag
= &raw
->frag
;
6821 if (perf_raw_frag_last(frag
))
6826 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6827 raw
->size
= size
- sizeof(u32
);
6828 frag
->pad
= raw
->size
- sum
;
6833 header
->size
+= size
;
6836 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6837 int size
= sizeof(u64
); /* nr */
6838 if (data
->br_stack
) {
6839 size
+= data
->br_stack
->nr
6840 * sizeof(struct perf_branch_entry
);
6842 header
->size
+= size
;
6845 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6846 perf_sample_regs_user(&data
->regs_user
, regs
,
6847 &data
->regs_user_copy
);
6849 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6850 /* regs dump ABI info */
6851 int size
= sizeof(u64
);
6853 if (data
->regs_user
.regs
) {
6854 u64 mask
= event
->attr
.sample_regs_user
;
6855 size
+= hweight64(mask
) * sizeof(u64
);
6858 header
->size
+= size
;
6861 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6863 * Either we need PERF_SAMPLE_STACK_USER bit to be always
6864 * processed as the last one or have additional check added
6865 * in case new sample type is added, because we could eat
6866 * up the rest of the sample size.
6868 u16 stack_size
= event
->attr
.sample_stack_user
;
6869 u16 size
= sizeof(u64
);
6871 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6872 data
->regs_user
.regs
);
6875 * If there is something to dump, add space for the dump
6876 * itself and for the field that tells the dynamic size,
6877 * which is how many have been actually dumped.
6880 size
+= sizeof(u64
) + stack_size
;
6882 data
->stack_user_size
= stack_size
;
6883 header
->size
+= size
;
6886 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6887 /* regs dump ABI info */
6888 int size
= sizeof(u64
);
6890 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6892 if (data
->regs_intr
.regs
) {
6893 u64 mask
= event
->attr
.sample_regs_intr
;
6895 size
+= hweight64(mask
) * sizeof(u64
);
6898 header
->size
+= size
;
6901 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6902 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6904 if (sample_type
& PERF_SAMPLE_AUX
) {
6907 header
->size
+= sizeof(u64
); /* size */
6910 * Given the 16bit nature of header::size, an AUX sample can
6911 * easily overflow it, what with all the preceding sample bits.
6912 * Make sure this doesn't happen by using up to U16_MAX bytes
6913 * per sample in total (rounded down to 8 byte boundary).
6915 size
= min_t(size_t, U16_MAX
- header
->size
,
6916 event
->attr
.aux_sample_size
);
6917 size
= rounddown(size
, 8);
6918 size
= perf_prepare_sample_aux(event
, data
, size
);
6920 WARN_ON_ONCE(size
+ header
->size
> U16_MAX
);
6921 header
->size
+= size
;
6924 * If you're adding more sample types here, you likely need to do
6925 * something about the overflowing header::size, like repurpose the
6926 * lowest 3 bits of size, which should be always zero at the moment.
6927 * This raises a more important question, do we really need 512k sized
6928 * samples and why, so good argumentation is in order for whatever you
6931 WARN_ON_ONCE(header
->size
& 7);
6934 static __always_inline
int
6935 __perf_event_output(struct perf_event
*event
,
6936 struct perf_sample_data
*data
,
6937 struct pt_regs
*regs
,
6938 int (*output_begin
)(struct perf_output_handle
*,
6939 struct perf_event
*,
6942 struct perf_output_handle handle
;
6943 struct perf_event_header header
;
6946 /* protect the callchain buffers */
6949 perf_prepare_sample(&header
, data
, event
, regs
);
6951 err
= output_begin(&handle
, event
, header
.size
);
6955 perf_output_sample(&handle
, &header
, data
, event
);
6957 perf_output_end(&handle
);
6965 perf_event_output_forward(struct perf_event
*event
,
6966 struct perf_sample_data
*data
,
6967 struct pt_regs
*regs
)
6969 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6973 perf_event_output_backward(struct perf_event
*event
,
6974 struct perf_sample_data
*data
,
6975 struct pt_regs
*regs
)
6977 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6981 perf_event_output(struct perf_event
*event
,
6982 struct perf_sample_data
*data
,
6983 struct pt_regs
*regs
)
6985 return __perf_event_output(event
, data
, regs
, perf_output_begin
);
6992 struct perf_read_event
{
6993 struct perf_event_header header
;
7000 perf_event_read_event(struct perf_event
*event
,
7001 struct task_struct
*task
)
7003 struct perf_output_handle handle
;
7004 struct perf_sample_data sample
;
7005 struct perf_read_event read_event
= {
7007 .type
= PERF_RECORD_READ
,
7009 .size
= sizeof(read_event
) + event
->read_size
,
7011 .pid
= perf_event_pid(event
, task
),
7012 .tid
= perf_event_tid(event
, task
),
7016 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
7017 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
7021 perf_output_put(&handle
, read_event
);
7022 perf_output_read(&handle
, event
);
7023 perf_event__output_id_sample(event
, &handle
, &sample
);
7025 perf_output_end(&handle
);
7028 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
7031 perf_iterate_ctx(struct perf_event_context
*ctx
,
7032 perf_iterate_f output
,
7033 void *data
, bool all
)
7035 struct perf_event
*event
;
7037 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7039 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7041 if (!event_filter_match(event
))
7045 output(event
, data
);
7049 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
7051 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
7052 struct perf_event
*event
;
7054 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
7056 * Skip events that are not fully formed yet; ensure that
7057 * if we observe event->ctx, both event and ctx will be
7058 * complete enough. See perf_install_in_context().
7060 if (!smp_load_acquire(&event
->ctx
))
7063 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
7065 if (!event_filter_match(event
))
7067 output(event
, data
);
7072 * Iterate all events that need to receive side-band events.
7074 * For new callers; ensure that account_pmu_sb_event() includes
7075 * your event, otherwise it might not get delivered.
7078 perf_iterate_sb(perf_iterate_f output
, void *data
,
7079 struct perf_event_context
*task_ctx
)
7081 struct perf_event_context
*ctx
;
7088 * If we have task_ctx != NULL we only notify the task context itself.
7089 * The task_ctx is set only for EXIT events before releasing task
7093 perf_iterate_ctx(task_ctx
, output
, data
, false);
7097 perf_iterate_sb_cpu(output
, data
);
7099 for_each_task_context_nr(ctxn
) {
7100 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7102 perf_iterate_ctx(ctx
, output
, data
, false);
7110 * Clear all file-based filters at exec, they'll have to be
7111 * re-instated when/if these objects are mmapped again.
7113 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
7115 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7116 struct perf_addr_filter
*filter
;
7117 unsigned int restart
= 0, count
= 0;
7118 unsigned long flags
;
7120 if (!has_addr_filter(event
))
7123 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7124 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7125 if (filter
->path
.dentry
) {
7126 event
->addr_filter_ranges
[count
].start
= 0;
7127 event
->addr_filter_ranges
[count
].size
= 0;
7135 event
->addr_filters_gen
++;
7136 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7139 perf_event_stop(event
, 1);
7142 void perf_event_exec(void)
7144 struct perf_event_context
*ctx
;
7148 for_each_task_context_nr(ctxn
) {
7149 ctx
= current
->perf_event_ctxp
[ctxn
];
7153 perf_event_enable_on_exec(ctxn
);
7155 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
7161 struct remote_output
{
7162 struct perf_buffer
*rb
;
7166 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
7168 struct perf_event
*parent
= event
->parent
;
7169 struct remote_output
*ro
= data
;
7170 struct perf_buffer
*rb
= ro
->rb
;
7171 struct stop_event_data sd
= {
7175 if (!has_aux(event
))
7182 * In case of inheritance, it will be the parent that links to the
7183 * ring-buffer, but it will be the child that's actually using it.
7185 * We are using event::rb to determine if the event should be stopped,
7186 * however this may race with ring_buffer_attach() (through set_output),
7187 * which will make us skip the event that actually needs to be stopped.
7188 * So ring_buffer_attach() has to stop an aux event before re-assigning
7191 if (rcu_dereference(parent
->rb
) == rb
)
7192 ro
->err
= __perf_event_stop(&sd
);
7195 static int __perf_pmu_output_stop(void *info
)
7197 struct perf_event
*event
= info
;
7198 struct pmu
*pmu
= event
->ctx
->pmu
;
7199 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7200 struct remote_output ro
= {
7205 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
7206 if (cpuctx
->task_ctx
)
7207 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
7214 static void perf_pmu_output_stop(struct perf_event
*event
)
7216 struct perf_event
*iter
;
7221 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
7223 * For per-CPU events, we need to make sure that neither they
7224 * nor their children are running; for cpu==-1 events it's
7225 * sufficient to stop the event itself if it's active, since
7226 * it can't have children.
7230 cpu
= READ_ONCE(iter
->oncpu
);
7235 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
7236 if (err
== -EAGAIN
) {
7245 * task tracking -- fork/exit
7247 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
7250 struct perf_task_event
{
7251 struct task_struct
*task
;
7252 struct perf_event_context
*task_ctx
;
7255 struct perf_event_header header
;
7265 static int perf_event_task_match(struct perf_event
*event
)
7267 return event
->attr
.comm
|| event
->attr
.mmap
||
7268 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
7272 static void perf_event_task_output(struct perf_event
*event
,
7275 struct perf_task_event
*task_event
= data
;
7276 struct perf_output_handle handle
;
7277 struct perf_sample_data sample
;
7278 struct task_struct
*task
= task_event
->task
;
7279 int ret
, size
= task_event
->event_id
.header
.size
;
7281 if (!perf_event_task_match(event
))
7284 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
7286 ret
= perf_output_begin(&handle
, event
,
7287 task_event
->event_id
.header
.size
);
7291 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
7292 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
7294 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
7295 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
7297 task_event
->event_id
.time
= perf_event_clock(event
);
7299 perf_output_put(&handle
, task_event
->event_id
);
7301 perf_event__output_id_sample(event
, &handle
, &sample
);
7303 perf_output_end(&handle
);
7305 task_event
->event_id
.header
.size
= size
;
7308 static void perf_event_task(struct task_struct
*task
,
7309 struct perf_event_context
*task_ctx
,
7312 struct perf_task_event task_event
;
7314 if (!atomic_read(&nr_comm_events
) &&
7315 !atomic_read(&nr_mmap_events
) &&
7316 !atomic_read(&nr_task_events
))
7319 task_event
= (struct perf_task_event
){
7321 .task_ctx
= task_ctx
,
7324 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
7326 .size
= sizeof(task_event
.event_id
),
7336 perf_iterate_sb(perf_event_task_output
,
7341 void perf_event_fork(struct task_struct
*task
)
7343 perf_event_task(task
, NULL
, 1);
7344 perf_event_namespaces(task
);
7351 struct perf_comm_event
{
7352 struct task_struct
*task
;
7357 struct perf_event_header header
;
7364 static int perf_event_comm_match(struct perf_event
*event
)
7366 return event
->attr
.comm
;
7369 static void perf_event_comm_output(struct perf_event
*event
,
7372 struct perf_comm_event
*comm_event
= data
;
7373 struct perf_output_handle handle
;
7374 struct perf_sample_data sample
;
7375 int size
= comm_event
->event_id
.header
.size
;
7378 if (!perf_event_comm_match(event
))
7381 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
7382 ret
= perf_output_begin(&handle
, event
,
7383 comm_event
->event_id
.header
.size
);
7388 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
7389 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
7391 perf_output_put(&handle
, comm_event
->event_id
);
7392 __output_copy(&handle
, comm_event
->comm
,
7393 comm_event
->comm_size
);
7395 perf_event__output_id_sample(event
, &handle
, &sample
);
7397 perf_output_end(&handle
);
7399 comm_event
->event_id
.header
.size
= size
;
7402 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
7404 char comm
[TASK_COMM_LEN
];
7407 memset(comm
, 0, sizeof(comm
));
7408 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
7409 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
7411 comm_event
->comm
= comm
;
7412 comm_event
->comm_size
= size
;
7414 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
7416 perf_iterate_sb(perf_event_comm_output
,
7421 void perf_event_comm(struct task_struct
*task
, bool exec
)
7423 struct perf_comm_event comm_event
;
7425 if (!atomic_read(&nr_comm_events
))
7428 comm_event
= (struct perf_comm_event
){
7434 .type
= PERF_RECORD_COMM
,
7435 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
7443 perf_event_comm_event(&comm_event
);
7447 * namespaces tracking
7450 struct perf_namespaces_event
{
7451 struct task_struct
*task
;
7454 struct perf_event_header header
;
7459 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
7463 static int perf_event_namespaces_match(struct perf_event
*event
)
7465 return event
->attr
.namespaces
;
7468 static void perf_event_namespaces_output(struct perf_event
*event
,
7471 struct perf_namespaces_event
*namespaces_event
= data
;
7472 struct perf_output_handle handle
;
7473 struct perf_sample_data sample
;
7474 u16 header_size
= namespaces_event
->event_id
.header
.size
;
7477 if (!perf_event_namespaces_match(event
))
7480 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
7482 ret
= perf_output_begin(&handle
, event
,
7483 namespaces_event
->event_id
.header
.size
);
7487 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
7488 namespaces_event
->task
);
7489 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
7490 namespaces_event
->task
);
7492 perf_output_put(&handle
, namespaces_event
->event_id
);
7494 perf_event__output_id_sample(event
, &handle
, &sample
);
7496 perf_output_end(&handle
);
7498 namespaces_event
->event_id
.header
.size
= header_size
;
7501 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
7502 struct task_struct
*task
,
7503 const struct proc_ns_operations
*ns_ops
)
7505 struct path ns_path
;
7506 struct inode
*ns_inode
;
7509 error
= ns_get_path(&ns_path
, task
, ns_ops
);
7511 ns_inode
= ns_path
.dentry
->d_inode
;
7512 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
7513 ns_link_info
->ino
= ns_inode
->i_ino
;
7518 void perf_event_namespaces(struct task_struct
*task
)
7520 struct perf_namespaces_event namespaces_event
;
7521 struct perf_ns_link_info
*ns_link_info
;
7523 if (!atomic_read(&nr_namespaces_events
))
7526 namespaces_event
= (struct perf_namespaces_event
){
7530 .type
= PERF_RECORD_NAMESPACES
,
7532 .size
= sizeof(namespaces_event
.event_id
),
7536 .nr_namespaces
= NR_NAMESPACES
,
7537 /* .link_info[NR_NAMESPACES] */
7541 ns_link_info
= namespaces_event
.event_id
.link_info
;
7543 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
7544 task
, &mntns_operations
);
7546 #ifdef CONFIG_USER_NS
7547 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
7548 task
, &userns_operations
);
7550 #ifdef CONFIG_NET_NS
7551 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
7552 task
, &netns_operations
);
7554 #ifdef CONFIG_UTS_NS
7555 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
7556 task
, &utsns_operations
);
7558 #ifdef CONFIG_IPC_NS
7559 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
7560 task
, &ipcns_operations
);
7562 #ifdef CONFIG_PID_NS
7563 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
7564 task
, &pidns_operations
);
7566 #ifdef CONFIG_CGROUPS
7567 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
7568 task
, &cgroupns_operations
);
7571 perf_iterate_sb(perf_event_namespaces_output
,
7580 struct perf_mmap_event
{
7581 struct vm_area_struct
*vma
;
7583 const char *file_name
;
7591 struct perf_event_header header
;
7601 static int perf_event_mmap_match(struct perf_event
*event
,
7604 struct perf_mmap_event
*mmap_event
= data
;
7605 struct vm_area_struct
*vma
= mmap_event
->vma
;
7606 int executable
= vma
->vm_flags
& VM_EXEC
;
7608 return (!executable
&& event
->attr
.mmap_data
) ||
7609 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
7612 static void perf_event_mmap_output(struct perf_event
*event
,
7615 struct perf_mmap_event
*mmap_event
= data
;
7616 struct perf_output_handle handle
;
7617 struct perf_sample_data sample
;
7618 int size
= mmap_event
->event_id
.header
.size
;
7619 u32 type
= mmap_event
->event_id
.header
.type
;
7622 if (!perf_event_mmap_match(event
, data
))
7625 if (event
->attr
.mmap2
) {
7626 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
7627 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
7628 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
7629 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
7630 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
7631 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
7632 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
7635 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
7636 ret
= perf_output_begin(&handle
, event
,
7637 mmap_event
->event_id
.header
.size
);
7641 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
7642 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
7644 perf_output_put(&handle
, mmap_event
->event_id
);
7646 if (event
->attr
.mmap2
) {
7647 perf_output_put(&handle
, mmap_event
->maj
);
7648 perf_output_put(&handle
, mmap_event
->min
);
7649 perf_output_put(&handle
, mmap_event
->ino
);
7650 perf_output_put(&handle
, mmap_event
->ino_generation
);
7651 perf_output_put(&handle
, mmap_event
->prot
);
7652 perf_output_put(&handle
, mmap_event
->flags
);
7655 __output_copy(&handle
, mmap_event
->file_name
,
7656 mmap_event
->file_size
);
7658 perf_event__output_id_sample(event
, &handle
, &sample
);
7660 perf_output_end(&handle
);
7662 mmap_event
->event_id
.header
.size
= size
;
7663 mmap_event
->event_id
.header
.type
= type
;
7666 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
7668 struct vm_area_struct
*vma
= mmap_event
->vma
;
7669 struct file
*file
= vma
->vm_file
;
7670 int maj
= 0, min
= 0;
7671 u64 ino
= 0, gen
= 0;
7672 u32 prot
= 0, flags
= 0;
7678 if (vma
->vm_flags
& VM_READ
)
7680 if (vma
->vm_flags
& VM_WRITE
)
7682 if (vma
->vm_flags
& VM_EXEC
)
7685 if (vma
->vm_flags
& VM_MAYSHARE
)
7688 flags
= MAP_PRIVATE
;
7690 if (vma
->vm_flags
& VM_DENYWRITE
)
7691 flags
|= MAP_DENYWRITE
;
7692 if (vma
->vm_flags
& VM_MAYEXEC
)
7693 flags
|= MAP_EXECUTABLE
;
7694 if (vma
->vm_flags
& VM_LOCKED
)
7695 flags
|= MAP_LOCKED
;
7696 if (vma
->vm_flags
& VM_HUGETLB
)
7697 flags
|= MAP_HUGETLB
;
7700 struct inode
*inode
;
7703 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
7709 * d_path() works from the end of the rb backwards, so we
7710 * need to add enough zero bytes after the string to handle
7711 * the 64bit alignment we do later.
7713 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
7718 inode
= file_inode(vma
->vm_file
);
7719 dev
= inode
->i_sb
->s_dev
;
7721 gen
= inode
->i_generation
;
7727 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
7728 name
= (char *) vma
->vm_ops
->name(vma
);
7733 name
= (char *)arch_vma_name(vma
);
7737 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
7738 vma
->vm_end
>= vma
->vm_mm
->brk
) {
7742 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
7743 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
7753 strlcpy(tmp
, name
, sizeof(tmp
));
7757 * Since our buffer works in 8 byte units we need to align our string
7758 * size to a multiple of 8. However, we must guarantee the tail end is
7759 * zero'd out to avoid leaking random bits to userspace.
7761 size
= strlen(name
)+1;
7762 while (!IS_ALIGNED(size
, sizeof(u64
)))
7763 name
[size
++] = '\0';
7765 mmap_event
->file_name
= name
;
7766 mmap_event
->file_size
= size
;
7767 mmap_event
->maj
= maj
;
7768 mmap_event
->min
= min
;
7769 mmap_event
->ino
= ino
;
7770 mmap_event
->ino_generation
= gen
;
7771 mmap_event
->prot
= prot
;
7772 mmap_event
->flags
= flags
;
7774 if (!(vma
->vm_flags
& VM_EXEC
))
7775 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
7777 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7779 perf_iterate_sb(perf_event_mmap_output
,
7787 * Check whether inode and address range match filter criteria.
7789 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7790 struct file
*file
, unsigned long offset
,
7793 /* d_inode(NULL) won't be equal to any mapped user-space file */
7794 if (!filter
->path
.dentry
)
7797 if (d_inode(filter
->path
.dentry
) != file_inode(file
))
7800 if (filter
->offset
> offset
+ size
)
7803 if (filter
->offset
+ filter
->size
< offset
)
7809 static bool perf_addr_filter_vma_adjust(struct perf_addr_filter
*filter
,
7810 struct vm_area_struct
*vma
,
7811 struct perf_addr_filter_range
*fr
)
7813 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
7814 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
7815 struct file
*file
= vma
->vm_file
;
7817 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
7820 if (filter
->offset
< off
) {
7821 fr
->start
= vma
->vm_start
;
7822 fr
->size
= min(vma_size
, filter
->size
- (off
- filter
->offset
));
7824 fr
->start
= vma
->vm_start
+ filter
->offset
- off
;
7825 fr
->size
= min(vma
->vm_end
- fr
->start
, filter
->size
);
7831 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7833 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7834 struct vm_area_struct
*vma
= data
;
7835 struct perf_addr_filter
*filter
;
7836 unsigned int restart
= 0, count
= 0;
7837 unsigned long flags
;
7839 if (!has_addr_filter(event
))
7845 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7846 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7847 if (perf_addr_filter_vma_adjust(filter
, vma
,
7848 &event
->addr_filter_ranges
[count
]))
7855 event
->addr_filters_gen
++;
7856 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7859 perf_event_stop(event
, 1);
7863 * Adjust all task's events' filters to the new vma
7865 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7867 struct perf_event_context
*ctx
;
7871 * Data tracing isn't supported yet and as such there is no need
7872 * to keep track of anything that isn't related to executable code:
7874 if (!(vma
->vm_flags
& VM_EXEC
))
7878 for_each_task_context_nr(ctxn
) {
7879 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7883 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7888 void perf_event_mmap(struct vm_area_struct
*vma
)
7890 struct perf_mmap_event mmap_event
;
7892 if (!atomic_read(&nr_mmap_events
))
7895 mmap_event
= (struct perf_mmap_event
){
7901 .type
= PERF_RECORD_MMAP
,
7902 .misc
= PERF_RECORD_MISC_USER
,
7907 .start
= vma
->vm_start
,
7908 .len
= vma
->vm_end
- vma
->vm_start
,
7909 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7911 /* .maj (attr_mmap2 only) */
7912 /* .min (attr_mmap2 only) */
7913 /* .ino (attr_mmap2 only) */
7914 /* .ino_generation (attr_mmap2 only) */
7915 /* .prot (attr_mmap2 only) */
7916 /* .flags (attr_mmap2 only) */
7919 perf_addr_filters_adjust(vma
);
7920 perf_event_mmap_event(&mmap_event
);
7923 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7924 unsigned long size
, u64 flags
)
7926 struct perf_output_handle handle
;
7927 struct perf_sample_data sample
;
7928 struct perf_aux_event
{
7929 struct perf_event_header header
;
7935 .type
= PERF_RECORD_AUX
,
7937 .size
= sizeof(rec
),
7945 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7946 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7951 perf_output_put(&handle
, rec
);
7952 perf_event__output_id_sample(event
, &handle
, &sample
);
7954 perf_output_end(&handle
);
7958 * Lost/dropped samples logging
7960 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7962 struct perf_output_handle handle
;
7963 struct perf_sample_data sample
;
7967 struct perf_event_header header
;
7969 } lost_samples_event
= {
7971 .type
= PERF_RECORD_LOST_SAMPLES
,
7973 .size
= sizeof(lost_samples_event
),
7978 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7980 ret
= perf_output_begin(&handle
, event
,
7981 lost_samples_event
.header
.size
);
7985 perf_output_put(&handle
, lost_samples_event
);
7986 perf_event__output_id_sample(event
, &handle
, &sample
);
7987 perf_output_end(&handle
);
7991 * context_switch tracking
7994 struct perf_switch_event
{
7995 struct task_struct
*task
;
7996 struct task_struct
*next_prev
;
7999 struct perf_event_header header
;
8005 static int perf_event_switch_match(struct perf_event
*event
)
8007 return event
->attr
.context_switch
;
8010 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
8012 struct perf_switch_event
*se
= data
;
8013 struct perf_output_handle handle
;
8014 struct perf_sample_data sample
;
8017 if (!perf_event_switch_match(event
))
8020 /* Only CPU-wide events are allowed to see next/prev pid/tid */
8021 if (event
->ctx
->task
) {
8022 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
8023 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
8025 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
8026 se
->event_id
.header
.size
= sizeof(se
->event_id
);
8027 se
->event_id
.next_prev_pid
=
8028 perf_event_pid(event
, se
->next_prev
);
8029 se
->event_id
.next_prev_tid
=
8030 perf_event_tid(event
, se
->next_prev
);
8033 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
8035 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
8039 if (event
->ctx
->task
)
8040 perf_output_put(&handle
, se
->event_id
.header
);
8042 perf_output_put(&handle
, se
->event_id
);
8044 perf_event__output_id_sample(event
, &handle
, &sample
);
8046 perf_output_end(&handle
);
8049 static void perf_event_switch(struct task_struct
*task
,
8050 struct task_struct
*next_prev
, bool sched_in
)
8052 struct perf_switch_event switch_event
;
8054 /* N.B. caller checks nr_switch_events != 0 */
8056 switch_event
= (struct perf_switch_event
){
8058 .next_prev
= next_prev
,
8062 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
8065 /* .next_prev_pid */
8066 /* .next_prev_tid */
8070 if (!sched_in
&& task
->state
== TASK_RUNNING
)
8071 switch_event
.event_id
.header
.misc
|=
8072 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT
;
8074 perf_iterate_sb(perf_event_switch_output
,
8080 * IRQ throttle logging
8083 static void perf_log_throttle(struct perf_event
*event
, int enable
)
8085 struct perf_output_handle handle
;
8086 struct perf_sample_data sample
;
8090 struct perf_event_header header
;
8094 } throttle_event
= {
8096 .type
= PERF_RECORD_THROTTLE
,
8098 .size
= sizeof(throttle_event
),
8100 .time
= perf_event_clock(event
),
8101 .id
= primary_event_id(event
),
8102 .stream_id
= event
->id
,
8106 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
8108 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
8110 ret
= perf_output_begin(&handle
, event
,
8111 throttle_event
.header
.size
);
8115 perf_output_put(&handle
, throttle_event
);
8116 perf_event__output_id_sample(event
, &handle
, &sample
);
8117 perf_output_end(&handle
);
8121 * ksymbol register/unregister tracking
8124 struct perf_ksymbol_event
{
8128 struct perf_event_header header
;
8136 static int perf_event_ksymbol_match(struct perf_event
*event
)
8138 return event
->attr
.ksymbol
;
8141 static void perf_event_ksymbol_output(struct perf_event
*event
, void *data
)
8143 struct perf_ksymbol_event
*ksymbol_event
= data
;
8144 struct perf_output_handle handle
;
8145 struct perf_sample_data sample
;
8148 if (!perf_event_ksymbol_match(event
))
8151 perf_event_header__init_id(&ksymbol_event
->event_id
.header
,
8153 ret
= perf_output_begin(&handle
, event
,
8154 ksymbol_event
->event_id
.header
.size
);
8158 perf_output_put(&handle
, ksymbol_event
->event_id
);
8159 __output_copy(&handle
, ksymbol_event
->name
, ksymbol_event
->name_len
);
8160 perf_event__output_id_sample(event
, &handle
, &sample
);
8162 perf_output_end(&handle
);
8165 void perf_event_ksymbol(u16 ksym_type
, u64 addr
, u32 len
, bool unregister
,
8168 struct perf_ksymbol_event ksymbol_event
;
8169 char name
[KSYM_NAME_LEN
];
8173 if (!atomic_read(&nr_ksymbol_events
))
8176 if (ksym_type
>= PERF_RECORD_KSYMBOL_TYPE_MAX
||
8177 ksym_type
== PERF_RECORD_KSYMBOL_TYPE_UNKNOWN
)
8180 strlcpy(name
, sym
, KSYM_NAME_LEN
);
8181 name_len
= strlen(name
) + 1;
8182 while (!IS_ALIGNED(name_len
, sizeof(u64
)))
8183 name
[name_len
++] = '\0';
8184 BUILD_BUG_ON(KSYM_NAME_LEN
% sizeof(u64
));
8187 flags
|= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER
;
8189 ksymbol_event
= (struct perf_ksymbol_event
){
8191 .name_len
= name_len
,
8194 .type
= PERF_RECORD_KSYMBOL
,
8195 .size
= sizeof(ksymbol_event
.event_id
) +
8200 .ksym_type
= ksym_type
,
8205 perf_iterate_sb(perf_event_ksymbol_output
, &ksymbol_event
, NULL
);
8208 WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__
, ksym_type
);
8212 * bpf program load/unload tracking
8215 struct perf_bpf_event
{
8216 struct bpf_prog
*prog
;
8218 struct perf_event_header header
;
8222 u8 tag
[BPF_TAG_SIZE
];
8226 static int perf_event_bpf_match(struct perf_event
*event
)
8228 return event
->attr
.bpf_event
;
8231 static void perf_event_bpf_output(struct perf_event
*event
, void *data
)
8233 struct perf_bpf_event
*bpf_event
= data
;
8234 struct perf_output_handle handle
;
8235 struct perf_sample_data sample
;
8238 if (!perf_event_bpf_match(event
))
8241 perf_event_header__init_id(&bpf_event
->event_id
.header
,
8243 ret
= perf_output_begin(&handle
, event
,
8244 bpf_event
->event_id
.header
.size
);
8248 perf_output_put(&handle
, bpf_event
->event_id
);
8249 perf_event__output_id_sample(event
, &handle
, &sample
);
8251 perf_output_end(&handle
);
8254 static void perf_event_bpf_emit_ksymbols(struct bpf_prog
*prog
,
8255 enum perf_bpf_event_type type
)
8257 bool unregister
= type
== PERF_BPF_EVENT_PROG_UNLOAD
;
8258 char sym
[KSYM_NAME_LEN
];
8261 if (prog
->aux
->func_cnt
== 0) {
8262 bpf_get_prog_name(prog
, sym
);
8263 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF
,
8264 (u64
)(unsigned long)prog
->bpf_func
,
8265 prog
->jited_len
, unregister
, sym
);
8267 for (i
= 0; i
< prog
->aux
->func_cnt
; i
++) {
8268 struct bpf_prog
*subprog
= prog
->aux
->func
[i
];
8270 bpf_get_prog_name(subprog
, sym
);
8272 PERF_RECORD_KSYMBOL_TYPE_BPF
,
8273 (u64
)(unsigned long)subprog
->bpf_func
,
8274 subprog
->jited_len
, unregister
, sym
);
8279 void perf_event_bpf_event(struct bpf_prog
*prog
,
8280 enum perf_bpf_event_type type
,
8283 struct perf_bpf_event bpf_event
;
8285 if (type
<= PERF_BPF_EVENT_UNKNOWN
||
8286 type
>= PERF_BPF_EVENT_MAX
)
8290 case PERF_BPF_EVENT_PROG_LOAD
:
8291 case PERF_BPF_EVENT_PROG_UNLOAD
:
8292 if (atomic_read(&nr_ksymbol_events
))
8293 perf_event_bpf_emit_ksymbols(prog
, type
);
8299 if (!atomic_read(&nr_bpf_events
))
8302 bpf_event
= (struct perf_bpf_event
){
8306 .type
= PERF_RECORD_BPF_EVENT
,
8307 .size
= sizeof(bpf_event
.event_id
),
8311 .id
= prog
->aux
->id
,
8315 BUILD_BUG_ON(BPF_TAG_SIZE
% sizeof(u64
));
8317 memcpy(bpf_event
.event_id
.tag
, prog
->tag
, BPF_TAG_SIZE
);
8318 perf_iterate_sb(perf_event_bpf_output
, &bpf_event
, NULL
);
8321 void perf_event_itrace_started(struct perf_event
*event
)
8323 event
->attach_state
|= PERF_ATTACH_ITRACE
;
8326 static void perf_log_itrace_start(struct perf_event
*event
)
8328 struct perf_output_handle handle
;
8329 struct perf_sample_data sample
;
8330 struct perf_aux_event
{
8331 struct perf_event_header header
;
8338 event
= event
->parent
;
8340 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
8341 event
->attach_state
& PERF_ATTACH_ITRACE
)
8344 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
8345 rec
.header
.misc
= 0;
8346 rec
.header
.size
= sizeof(rec
);
8347 rec
.pid
= perf_event_pid(event
, current
);
8348 rec
.tid
= perf_event_tid(event
, current
);
8350 perf_event_header__init_id(&rec
.header
, &sample
, event
);
8351 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
8356 perf_output_put(&handle
, rec
);
8357 perf_event__output_id_sample(event
, &handle
, &sample
);
8359 perf_output_end(&handle
);
8363 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
8365 struct hw_perf_event
*hwc
= &event
->hw
;
8369 seq
= __this_cpu_read(perf_throttled_seq
);
8370 if (seq
!= hwc
->interrupts_seq
) {
8371 hwc
->interrupts_seq
= seq
;
8372 hwc
->interrupts
= 1;
8375 if (unlikely(throttle
8376 && hwc
->interrupts
>= max_samples_per_tick
)) {
8377 __this_cpu_inc(perf_throttled_count
);
8378 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
8379 hwc
->interrupts
= MAX_INTERRUPTS
;
8380 perf_log_throttle(event
, 0);
8385 if (event
->attr
.freq
) {
8386 u64 now
= perf_clock();
8387 s64 delta
= now
- hwc
->freq_time_stamp
;
8389 hwc
->freq_time_stamp
= now
;
8391 if (delta
> 0 && delta
< 2*TICK_NSEC
)
8392 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
8398 int perf_event_account_interrupt(struct perf_event
*event
)
8400 return __perf_event_account_interrupt(event
, 1);
8404 * Generic event overflow handling, sampling.
8407 static int __perf_event_overflow(struct perf_event
*event
,
8408 int throttle
, struct perf_sample_data
*data
,
8409 struct pt_regs
*regs
)
8411 int events
= atomic_read(&event
->event_limit
);
8415 * Non-sampling counters might still use the PMI to fold short
8416 * hardware counters, ignore those.
8418 if (unlikely(!is_sampling_event(event
)))
8421 ret
= __perf_event_account_interrupt(event
, throttle
);
8424 * XXX event_limit might not quite work as expected on inherited
8428 event
->pending_kill
= POLL_IN
;
8429 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
8431 event
->pending_kill
= POLL_HUP
;
8433 perf_event_disable_inatomic(event
);
8436 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
8438 if (*perf_event_fasync(event
) && event
->pending_kill
) {
8439 event
->pending_wakeup
= 1;
8440 irq_work_queue(&event
->pending
);
8446 int perf_event_overflow(struct perf_event
*event
,
8447 struct perf_sample_data
*data
,
8448 struct pt_regs
*regs
)
8450 return __perf_event_overflow(event
, 1, data
, regs
);
8454 * Generic software event infrastructure
8457 struct swevent_htable
{
8458 struct swevent_hlist
*swevent_hlist
;
8459 struct mutex hlist_mutex
;
8462 /* Recursion avoidance in each contexts */
8463 int recursion
[PERF_NR_CONTEXTS
];
8466 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
8469 * We directly increment event->count and keep a second value in
8470 * event->hw.period_left to count intervals. This period event
8471 * is kept in the range [-sample_period, 0] so that we can use the
8475 u64
perf_swevent_set_period(struct perf_event
*event
)
8477 struct hw_perf_event
*hwc
= &event
->hw
;
8478 u64 period
= hwc
->last_period
;
8482 hwc
->last_period
= hwc
->sample_period
;
8485 old
= val
= local64_read(&hwc
->period_left
);
8489 nr
= div64_u64(period
+ val
, period
);
8490 offset
= nr
* period
;
8492 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
8498 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
8499 struct perf_sample_data
*data
,
8500 struct pt_regs
*regs
)
8502 struct hw_perf_event
*hwc
= &event
->hw
;
8506 overflow
= perf_swevent_set_period(event
);
8508 if (hwc
->interrupts
== MAX_INTERRUPTS
)
8511 for (; overflow
; overflow
--) {
8512 if (__perf_event_overflow(event
, throttle
,
8515 * We inhibit the overflow from happening when
8516 * hwc->interrupts == MAX_INTERRUPTS.
8524 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
8525 struct perf_sample_data
*data
,
8526 struct pt_regs
*regs
)
8528 struct hw_perf_event
*hwc
= &event
->hw
;
8530 local64_add(nr
, &event
->count
);
8535 if (!is_sampling_event(event
))
8538 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
8540 return perf_swevent_overflow(event
, 1, data
, regs
);
8542 data
->period
= event
->hw
.last_period
;
8544 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
8545 return perf_swevent_overflow(event
, 1, data
, regs
);
8547 if (local64_add_negative(nr
, &hwc
->period_left
))
8550 perf_swevent_overflow(event
, 0, data
, regs
);
8553 static int perf_exclude_event(struct perf_event
*event
,
8554 struct pt_regs
*regs
)
8556 if (event
->hw
.state
& PERF_HES_STOPPED
)
8560 if (event
->attr
.exclude_user
&& user_mode(regs
))
8563 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
8570 static int perf_swevent_match(struct perf_event
*event
,
8571 enum perf_type_id type
,
8573 struct perf_sample_data
*data
,
8574 struct pt_regs
*regs
)
8576 if (event
->attr
.type
!= type
)
8579 if (event
->attr
.config
!= event_id
)
8582 if (perf_exclude_event(event
, regs
))
8588 static inline u64
swevent_hash(u64 type
, u32 event_id
)
8590 u64 val
= event_id
| (type
<< 32);
8592 return hash_64(val
, SWEVENT_HLIST_BITS
);
8595 static inline struct hlist_head
*
8596 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
8598 u64 hash
= swevent_hash(type
, event_id
);
8600 return &hlist
->heads
[hash
];
8603 /* For the read side: events when they trigger */
8604 static inline struct hlist_head
*
8605 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
8607 struct swevent_hlist
*hlist
;
8609 hlist
= rcu_dereference(swhash
->swevent_hlist
);
8613 return __find_swevent_head(hlist
, type
, event_id
);
8616 /* For the event head insertion and removal in the hlist */
8617 static inline struct hlist_head
*
8618 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
8620 struct swevent_hlist
*hlist
;
8621 u32 event_id
= event
->attr
.config
;
8622 u64 type
= event
->attr
.type
;
8625 * Event scheduling is always serialized against hlist allocation
8626 * and release. Which makes the protected version suitable here.
8627 * The context lock guarantees that.
8629 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
8630 lockdep_is_held(&event
->ctx
->lock
));
8634 return __find_swevent_head(hlist
, type
, event_id
);
8637 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
8639 struct perf_sample_data
*data
,
8640 struct pt_regs
*regs
)
8642 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8643 struct perf_event
*event
;
8644 struct hlist_head
*head
;
8647 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
8651 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8652 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
8653 perf_swevent_event(event
, nr
, data
, regs
);
8659 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
8661 int perf_swevent_get_recursion_context(void)
8663 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8665 return get_recursion_context(swhash
->recursion
);
8667 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
8669 void perf_swevent_put_recursion_context(int rctx
)
8671 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8673 put_recursion_context(swhash
->recursion
, rctx
);
8676 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8678 struct perf_sample_data data
;
8680 if (WARN_ON_ONCE(!regs
))
8683 perf_sample_data_init(&data
, addr
, 0);
8684 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
8687 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8691 preempt_disable_notrace();
8692 rctx
= perf_swevent_get_recursion_context();
8693 if (unlikely(rctx
< 0))
8696 ___perf_sw_event(event_id
, nr
, regs
, addr
);
8698 perf_swevent_put_recursion_context(rctx
);
8700 preempt_enable_notrace();
8703 static void perf_swevent_read(struct perf_event
*event
)
8707 static int perf_swevent_add(struct perf_event
*event
, int flags
)
8709 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8710 struct hw_perf_event
*hwc
= &event
->hw
;
8711 struct hlist_head
*head
;
8713 if (is_sampling_event(event
)) {
8714 hwc
->last_period
= hwc
->sample_period
;
8715 perf_swevent_set_period(event
);
8718 hwc
->state
= !(flags
& PERF_EF_START
);
8720 head
= find_swevent_head(swhash
, event
);
8721 if (WARN_ON_ONCE(!head
))
8724 hlist_add_head_rcu(&event
->hlist_entry
, head
);
8725 perf_event_update_userpage(event
);
8730 static void perf_swevent_del(struct perf_event
*event
, int flags
)
8732 hlist_del_rcu(&event
->hlist_entry
);
8735 static void perf_swevent_start(struct perf_event
*event
, int flags
)
8737 event
->hw
.state
= 0;
8740 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
8742 event
->hw
.state
= PERF_HES_STOPPED
;
8745 /* Deref the hlist from the update side */
8746 static inline struct swevent_hlist
*
8747 swevent_hlist_deref(struct swevent_htable
*swhash
)
8749 return rcu_dereference_protected(swhash
->swevent_hlist
,
8750 lockdep_is_held(&swhash
->hlist_mutex
));
8753 static void swevent_hlist_release(struct swevent_htable
*swhash
)
8755 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
8760 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
8761 kfree_rcu(hlist
, rcu_head
);
8764 static void swevent_hlist_put_cpu(int cpu
)
8766 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8768 mutex_lock(&swhash
->hlist_mutex
);
8770 if (!--swhash
->hlist_refcount
)
8771 swevent_hlist_release(swhash
);
8773 mutex_unlock(&swhash
->hlist_mutex
);
8776 static void swevent_hlist_put(void)
8780 for_each_possible_cpu(cpu
)
8781 swevent_hlist_put_cpu(cpu
);
8784 static int swevent_hlist_get_cpu(int cpu
)
8786 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8789 mutex_lock(&swhash
->hlist_mutex
);
8790 if (!swevent_hlist_deref(swhash
) &&
8791 cpumask_test_cpu(cpu
, perf_online_mask
)) {
8792 struct swevent_hlist
*hlist
;
8794 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
8799 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
8801 swhash
->hlist_refcount
++;
8803 mutex_unlock(&swhash
->hlist_mutex
);
8808 static int swevent_hlist_get(void)
8810 int err
, cpu
, failed_cpu
;
8812 mutex_lock(&pmus_lock
);
8813 for_each_possible_cpu(cpu
) {
8814 err
= swevent_hlist_get_cpu(cpu
);
8820 mutex_unlock(&pmus_lock
);
8823 for_each_possible_cpu(cpu
) {
8824 if (cpu
== failed_cpu
)
8826 swevent_hlist_put_cpu(cpu
);
8828 mutex_unlock(&pmus_lock
);
8832 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
8834 static void sw_perf_event_destroy(struct perf_event
*event
)
8836 u64 event_id
= event
->attr
.config
;
8838 WARN_ON(event
->parent
);
8840 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
8841 swevent_hlist_put();
8844 static int perf_swevent_init(struct perf_event
*event
)
8846 u64 event_id
= event
->attr
.config
;
8848 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8852 * no branch sampling for software events
8854 if (has_branch_stack(event
))
8858 case PERF_COUNT_SW_CPU_CLOCK
:
8859 case PERF_COUNT_SW_TASK_CLOCK
:
8866 if (event_id
>= PERF_COUNT_SW_MAX
)
8869 if (!event
->parent
) {
8872 err
= swevent_hlist_get();
8876 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
8877 event
->destroy
= sw_perf_event_destroy
;
8883 static struct pmu perf_swevent
= {
8884 .task_ctx_nr
= perf_sw_context
,
8886 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8888 .event_init
= perf_swevent_init
,
8889 .add
= perf_swevent_add
,
8890 .del
= perf_swevent_del
,
8891 .start
= perf_swevent_start
,
8892 .stop
= perf_swevent_stop
,
8893 .read
= perf_swevent_read
,
8896 #ifdef CONFIG_EVENT_TRACING
8898 static int perf_tp_filter_match(struct perf_event
*event
,
8899 struct perf_sample_data
*data
)
8901 void *record
= data
->raw
->frag
.data
;
8903 /* only top level events have filters set */
8905 event
= event
->parent
;
8907 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
8912 static int perf_tp_event_match(struct perf_event
*event
,
8913 struct perf_sample_data
*data
,
8914 struct pt_regs
*regs
)
8916 if (event
->hw
.state
& PERF_HES_STOPPED
)
8919 * If exclude_kernel, only trace user-space tracepoints (uprobes)
8921 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
8924 if (!perf_tp_filter_match(event
, data
))
8930 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
8931 struct trace_event_call
*call
, u64 count
,
8932 struct pt_regs
*regs
, struct hlist_head
*head
,
8933 struct task_struct
*task
)
8935 if (bpf_prog_array_valid(call
)) {
8936 *(struct pt_regs
**)raw_data
= regs
;
8937 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
8938 perf_swevent_put_recursion_context(rctx
);
8942 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
8945 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
8947 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
8948 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
8949 struct task_struct
*task
)
8951 struct perf_sample_data data
;
8952 struct perf_event
*event
;
8954 struct perf_raw_record raw
= {
8961 perf_sample_data_init(&data
, 0, 0);
8964 perf_trace_buf_update(record
, event_type
);
8966 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8967 if (perf_tp_event_match(event
, &data
, regs
))
8968 perf_swevent_event(event
, count
, &data
, regs
);
8972 * If we got specified a target task, also iterate its context and
8973 * deliver this event there too.
8975 if (task
&& task
!= current
) {
8976 struct perf_event_context
*ctx
;
8977 struct trace_entry
*entry
= record
;
8980 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
8984 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
8985 if (event
->cpu
!= smp_processor_id())
8987 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8989 if (event
->attr
.config
!= entry
->type
)
8991 if (perf_tp_event_match(event
, &data
, regs
))
8992 perf_swevent_event(event
, count
, &data
, regs
);
8998 perf_swevent_put_recursion_context(rctx
);
9000 EXPORT_SYMBOL_GPL(perf_tp_event
);
9002 static void tp_perf_event_destroy(struct perf_event
*event
)
9004 perf_trace_destroy(event
);
9007 static int perf_tp_event_init(struct perf_event
*event
)
9011 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
9015 * no branch sampling for tracepoint events
9017 if (has_branch_stack(event
))
9020 err
= perf_trace_init(event
);
9024 event
->destroy
= tp_perf_event_destroy
;
9029 static struct pmu perf_tracepoint
= {
9030 .task_ctx_nr
= perf_sw_context
,
9032 .event_init
= perf_tp_event_init
,
9033 .add
= perf_trace_add
,
9034 .del
= perf_trace_del
,
9035 .start
= perf_swevent_start
,
9036 .stop
= perf_swevent_stop
,
9037 .read
= perf_swevent_read
,
9040 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
9042 * Flags in config, used by dynamic PMU kprobe and uprobe
9043 * The flags should match following PMU_FORMAT_ATTR().
9045 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
9046 * if not set, create kprobe/uprobe
9048 * The following values specify a reference counter (or semaphore in the
9049 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
9050 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
9052 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
9053 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
9055 enum perf_probe_config
{
9056 PERF_PROBE_CONFIG_IS_RETPROBE
= 1U << 0, /* [k,u]retprobe */
9057 PERF_UPROBE_REF_CTR_OFFSET_BITS
= 32,
9058 PERF_UPROBE_REF_CTR_OFFSET_SHIFT
= 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS
,
9061 PMU_FORMAT_ATTR(retprobe
, "config:0");
9064 #ifdef CONFIG_KPROBE_EVENTS
9065 static struct attribute
*kprobe_attrs
[] = {
9066 &format_attr_retprobe
.attr
,
9070 static struct attribute_group kprobe_format_group
= {
9072 .attrs
= kprobe_attrs
,
9075 static const struct attribute_group
*kprobe_attr_groups
[] = {
9076 &kprobe_format_group
,
9080 static int perf_kprobe_event_init(struct perf_event
*event
);
9081 static struct pmu perf_kprobe
= {
9082 .task_ctx_nr
= perf_sw_context
,
9083 .event_init
= perf_kprobe_event_init
,
9084 .add
= perf_trace_add
,
9085 .del
= perf_trace_del
,
9086 .start
= perf_swevent_start
,
9087 .stop
= perf_swevent_stop
,
9088 .read
= perf_swevent_read
,
9089 .attr_groups
= kprobe_attr_groups
,
9092 static int perf_kprobe_event_init(struct perf_event
*event
)
9097 if (event
->attr
.type
!= perf_kprobe
.type
)
9100 if (!capable(CAP_SYS_ADMIN
))
9104 * no branch sampling for probe events
9106 if (has_branch_stack(event
))
9109 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9110 err
= perf_kprobe_init(event
, is_retprobe
);
9114 event
->destroy
= perf_kprobe_destroy
;
9118 #endif /* CONFIG_KPROBE_EVENTS */
9120 #ifdef CONFIG_UPROBE_EVENTS
9121 PMU_FORMAT_ATTR(ref_ctr_offset
, "config:32-63");
9123 static struct attribute
*uprobe_attrs
[] = {
9124 &format_attr_retprobe
.attr
,
9125 &format_attr_ref_ctr_offset
.attr
,
9129 static struct attribute_group uprobe_format_group
= {
9131 .attrs
= uprobe_attrs
,
9134 static const struct attribute_group
*uprobe_attr_groups
[] = {
9135 &uprobe_format_group
,
9139 static int perf_uprobe_event_init(struct perf_event
*event
);
9140 static struct pmu perf_uprobe
= {
9141 .task_ctx_nr
= perf_sw_context
,
9142 .event_init
= perf_uprobe_event_init
,
9143 .add
= perf_trace_add
,
9144 .del
= perf_trace_del
,
9145 .start
= perf_swevent_start
,
9146 .stop
= perf_swevent_stop
,
9147 .read
= perf_swevent_read
,
9148 .attr_groups
= uprobe_attr_groups
,
9151 static int perf_uprobe_event_init(struct perf_event
*event
)
9154 unsigned long ref_ctr_offset
;
9157 if (event
->attr
.type
!= perf_uprobe
.type
)
9160 if (!capable(CAP_SYS_ADMIN
))
9164 * no branch sampling for probe events
9166 if (has_branch_stack(event
))
9169 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
9170 ref_ctr_offset
= event
->attr
.config
>> PERF_UPROBE_REF_CTR_OFFSET_SHIFT
;
9171 err
= perf_uprobe_init(event
, ref_ctr_offset
, is_retprobe
);
9175 event
->destroy
= perf_uprobe_destroy
;
9179 #endif /* CONFIG_UPROBE_EVENTS */
9181 static inline void perf_tp_register(void)
9183 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
9184 #ifdef CONFIG_KPROBE_EVENTS
9185 perf_pmu_register(&perf_kprobe
, "kprobe", -1);
9187 #ifdef CONFIG_UPROBE_EVENTS
9188 perf_pmu_register(&perf_uprobe
, "uprobe", -1);
9192 static void perf_event_free_filter(struct perf_event
*event
)
9194 ftrace_profile_free_filter(event
);
9197 #ifdef CONFIG_BPF_SYSCALL
9198 static void bpf_overflow_handler(struct perf_event
*event
,
9199 struct perf_sample_data
*data
,
9200 struct pt_regs
*regs
)
9202 struct bpf_perf_event_data_kern ctx
= {
9208 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
9209 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
9212 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
9215 __this_cpu_dec(bpf_prog_active
);
9219 event
->orig_overflow_handler(event
, data
, regs
);
9222 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
9224 struct bpf_prog
*prog
;
9226 if (event
->overflow_handler_context
)
9227 /* hw breakpoint or kernel counter */
9233 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
9235 return PTR_ERR(prog
);
9238 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
9239 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
9243 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9245 struct bpf_prog
*prog
= event
->prog
;
9250 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
9255 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
9259 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9265 * returns true if the event is a tracepoint, or a kprobe/upprobe created
9266 * with perf_event_open()
9268 static inline bool perf_event_is_tracing(struct perf_event
*event
)
9270 if (event
->pmu
== &perf_tracepoint
)
9272 #ifdef CONFIG_KPROBE_EVENTS
9273 if (event
->pmu
== &perf_kprobe
)
9276 #ifdef CONFIG_UPROBE_EVENTS
9277 if (event
->pmu
== &perf_uprobe
)
9283 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9285 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
9286 struct bpf_prog
*prog
;
9289 if (!perf_event_is_tracing(event
))
9290 return perf_event_set_bpf_handler(event
, prog_fd
);
9292 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
9293 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
9294 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
9295 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
9296 /* bpf programs can only be attached to u/kprobe or tracepoint */
9299 prog
= bpf_prog_get(prog_fd
);
9301 return PTR_ERR(prog
);
9303 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
9304 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
9305 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
9306 /* valid fd, but invalid bpf program type */
9311 /* Kprobe override only works for kprobes, not uprobes. */
9312 if (prog
->kprobe_override
&&
9313 !(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
)) {
9318 if (is_tracepoint
|| is_syscall_tp
) {
9319 int off
= trace_event_get_offsets(event
->tp_event
);
9321 if (prog
->aux
->max_ctx_offset
> off
) {
9327 ret
= perf_event_attach_bpf_prog(event
, prog
);
9333 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9335 if (!perf_event_is_tracing(event
)) {
9336 perf_event_free_bpf_handler(event
);
9339 perf_event_detach_bpf_prog(event
);
9344 static inline void perf_tp_register(void)
9348 static void perf_event_free_filter(struct perf_event
*event
)
9352 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9357 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9360 #endif /* CONFIG_EVENT_TRACING */
9362 #ifdef CONFIG_HAVE_HW_BREAKPOINT
9363 void perf_bp_event(struct perf_event
*bp
, void *data
)
9365 struct perf_sample_data sample
;
9366 struct pt_regs
*regs
= data
;
9368 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
9370 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
9371 perf_swevent_event(bp
, 1, &sample
, regs
);
9376 * Allocate a new address filter
9378 static struct perf_addr_filter
*
9379 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
9381 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
9382 struct perf_addr_filter
*filter
;
9384 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
9388 INIT_LIST_HEAD(&filter
->entry
);
9389 list_add_tail(&filter
->entry
, filters
);
9394 static void free_filters_list(struct list_head
*filters
)
9396 struct perf_addr_filter
*filter
, *iter
;
9398 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
9399 path_put(&filter
->path
);
9400 list_del(&filter
->entry
);
9406 * Free existing address filters and optionally install new ones
9408 static void perf_addr_filters_splice(struct perf_event
*event
,
9409 struct list_head
*head
)
9411 unsigned long flags
;
9414 if (!has_addr_filter(event
))
9417 /* don't bother with children, they don't have their own filters */
9421 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
9423 list_splice_init(&event
->addr_filters
.list
, &list
);
9425 list_splice(head
, &event
->addr_filters
.list
);
9427 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
9429 free_filters_list(&list
);
9433 * Scan through mm's vmas and see if one of them matches the
9434 * @filter; if so, adjust filter's address range.
9435 * Called with mm::mmap_sem down for reading.
9437 static void perf_addr_filter_apply(struct perf_addr_filter
*filter
,
9438 struct mm_struct
*mm
,
9439 struct perf_addr_filter_range
*fr
)
9441 struct vm_area_struct
*vma
;
9443 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
9447 if (perf_addr_filter_vma_adjust(filter
, vma
, fr
))
9453 * Update event's address range filters based on the
9454 * task's existing mappings, if any.
9456 static void perf_event_addr_filters_apply(struct perf_event
*event
)
9458 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
9459 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
9460 struct perf_addr_filter
*filter
;
9461 struct mm_struct
*mm
= NULL
;
9462 unsigned int count
= 0;
9463 unsigned long flags
;
9466 * We may observe TASK_TOMBSTONE, which means that the event tear-down
9467 * will stop on the parent's child_mutex that our caller is also holding
9469 if (task
== TASK_TOMBSTONE
)
9472 if (ifh
->nr_file_filters
) {
9473 mm
= get_task_mm(event
->ctx
->task
);
9477 down_read(&mm
->mmap_sem
);
9480 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
9481 list_for_each_entry(filter
, &ifh
->list
, entry
) {
9482 if (filter
->path
.dentry
) {
9484 * Adjust base offset if the filter is associated to a
9485 * binary that needs to be mapped:
9487 event
->addr_filter_ranges
[count
].start
= 0;
9488 event
->addr_filter_ranges
[count
].size
= 0;
9490 perf_addr_filter_apply(filter
, mm
, &event
->addr_filter_ranges
[count
]);
9492 event
->addr_filter_ranges
[count
].start
= filter
->offset
;
9493 event
->addr_filter_ranges
[count
].size
= filter
->size
;
9499 event
->addr_filters_gen
++;
9500 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
9502 if (ifh
->nr_file_filters
) {
9503 up_read(&mm
->mmap_sem
);
9509 perf_event_stop(event
, 1);
9513 * Address range filtering: limiting the data to certain
9514 * instruction address ranges. Filters are ioctl()ed to us from
9515 * userspace as ascii strings.
9517 * Filter string format:
9520 * where ACTION is one of the
9521 * * "filter": limit the trace to this region
9522 * * "start": start tracing from this address
9523 * * "stop": stop tracing at this address/region;
9525 * * for kernel addresses: <start address>[/<size>]
9526 * * for object files: <start address>[/<size>]@</path/to/object/file>
9528 * if <size> is not specified or is zero, the range is treated as a single
9529 * address; not valid for ACTION=="filter".
9543 IF_STATE_ACTION
= 0,
9548 static const match_table_t if_tokens
= {
9549 { IF_ACT_FILTER
, "filter" },
9550 { IF_ACT_START
, "start" },
9551 { IF_ACT_STOP
, "stop" },
9552 { IF_SRC_FILE
, "%u/%u@%s" },
9553 { IF_SRC_KERNEL
, "%u/%u" },
9554 { IF_SRC_FILEADDR
, "%u@%s" },
9555 { IF_SRC_KERNELADDR
, "%u" },
9556 { IF_ACT_NONE
, NULL
},
9560 * Address filter string parser
9563 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
9564 struct list_head
*filters
)
9566 struct perf_addr_filter
*filter
= NULL
;
9567 char *start
, *orig
, *filename
= NULL
;
9568 substring_t args
[MAX_OPT_ARGS
];
9569 int state
= IF_STATE_ACTION
, token
;
9570 unsigned int kernel
= 0;
9573 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
9577 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
9578 static const enum perf_addr_filter_action_t actions
[] = {
9579 [IF_ACT_FILTER
] = PERF_ADDR_FILTER_ACTION_FILTER
,
9580 [IF_ACT_START
] = PERF_ADDR_FILTER_ACTION_START
,
9581 [IF_ACT_STOP
] = PERF_ADDR_FILTER_ACTION_STOP
,
9588 /* filter definition begins */
9589 if (state
== IF_STATE_ACTION
) {
9590 filter
= perf_addr_filter_new(event
, filters
);
9595 token
= match_token(start
, if_tokens
, args
);
9600 if (state
!= IF_STATE_ACTION
)
9603 filter
->action
= actions
[token
];
9604 state
= IF_STATE_SOURCE
;
9607 case IF_SRC_KERNELADDR
:
9612 case IF_SRC_FILEADDR
:
9614 if (state
!= IF_STATE_SOURCE
)
9618 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
9622 if (token
== IF_SRC_KERNEL
|| token
== IF_SRC_FILE
) {
9624 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
9629 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
9630 int fpos
= token
== IF_SRC_FILE
? 2 : 1;
9632 filename
= match_strdup(&args
[fpos
]);
9639 state
= IF_STATE_END
;
9647 * Filter definition is fully parsed, validate and install it.
9648 * Make sure that it doesn't contradict itself or the event's
9651 if (state
== IF_STATE_END
) {
9653 if (kernel
&& event
->attr
.exclude_kernel
)
9657 * ACTION "filter" must have a non-zero length region
9660 if (filter
->action
== PERF_ADDR_FILTER_ACTION_FILTER
&&
9669 * For now, we only support file-based filters
9670 * in per-task events; doing so for CPU-wide
9671 * events requires additional context switching
9672 * trickery, since same object code will be
9673 * mapped at different virtual addresses in
9674 * different processes.
9677 if (!event
->ctx
->task
)
9678 goto fail_free_name
;
9680 /* look up the path and grab its inode */
9681 ret
= kern_path(filename
, LOOKUP_FOLLOW
,
9684 goto fail_free_name
;
9690 if (!filter
->path
.dentry
||
9691 !S_ISREG(d_inode(filter
->path
.dentry
)
9695 event
->addr_filters
.nr_file_filters
++;
9698 /* ready to consume more filters */
9699 state
= IF_STATE_ACTION
;
9704 if (state
!= IF_STATE_ACTION
)
9714 free_filters_list(filters
);
9721 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
9727 * Since this is called in perf_ioctl() path, we're already holding
9730 lockdep_assert_held(&event
->ctx
->mutex
);
9732 if (WARN_ON_ONCE(event
->parent
))
9735 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
9737 goto fail_clear_files
;
9739 ret
= event
->pmu
->addr_filters_validate(&filters
);
9741 goto fail_free_filters
;
9743 /* remove existing filters, if any */
9744 perf_addr_filters_splice(event
, &filters
);
9746 /* install new filters */
9747 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
9752 free_filters_list(&filters
);
9755 event
->addr_filters
.nr_file_filters
= 0;
9760 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
9765 filter_str
= strndup_user(arg
, PAGE_SIZE
);
9766 if (IS_ERR(filter_str
))
9767 return PTR_ERR(filter_str
);
9769 #ifdef CONFIG_EVENT_TRACING
9770 if (perf_event_is_tracing(event
)) {
9771 struct perf_event_context
*ctx
= event
->ctx
;
9774 * Beware, here be dragons!!
9776 * the tracepoint muck will deadlock against ctx->mutex, but
9777 * the tracepoint stuff does not actually need it. So
9778 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
9779 * already have a reference on ctx.
9781 * This can result in event getting moved to a different ctx,
9782 * but that does not affect the tracepoint state.
9784 mutex_unlock(&ctx
->mutex
);
9785 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
9786 mutex_lock(&ctx
->mutex
);
9789 if (has_addr_filter(event
))
9790 ret
= perf_event_set_addr_filter(event
, filter_str
);
9797 * hrtimer based swevent callback
9800 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
9802 enum hrtimer_restart ret
= HRTIMER_RESTART
;
9803 struct perf_sample_data data
;
9804 struct pt_regs
*regs
;
9805 struct perf_event
*event
;
9808 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
9810 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
9811 return HRTIMER_NORESTART
;
9813 event
->pmu
->read(event
);
9815 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
9816 regs
= get_irq_regs();
9818 if (regs
&& !perf_exclude_event(event
, regs
)) {
9819 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
9820 if (__perf_event_overflow(event
, 1, &data
, regs
))
9821 ret
= HRTIMER_NORESTART
;
9824 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
9825 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
9830 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
9832 struct hw_perf_event
*hwc
= &event
->hw
;
9835 if (!is_sampling_event(event
))
9838 period
= local64_read(&hwc
->period_left
);
9843 local64_set(&hwc
->period_left
, 0);
9845 period
= max_t(u64
, 10000, hwc
->sample_period
);
9847 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
9848 HRTIMER_MODE_REL_PINNED_HARD
);
9851 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
9853 struct hw_perf_event
*hwc
= &event
->hw
;
9855 if (is_sampling_event(event
)) {
9856 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
9857 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
9859 hrtimer_cancel(&hwc
->hrtimer
);
9863 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
9865 struct hw_perf_event
*hwc
= &event
->hw
;
9867 if (!is_sampling_event(event
))
9870 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_HARD
);
9871 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
9874 * Since hrtimers have a fixed rate, we can do a static freq->period
9875 * mapping and avoid the whole period adjust feedback stuff.
9877 if (event
->attr
.freq
) {
9878 long freq
= event
->attr
.sample_freq
;
9880 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
9881 hwc
->sample_period
= event
->attr
.sample_period
;
9882 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9883 hwc
->last_period
= hwc
->sample_period
;
9884 event
->attr
.freq
= 0;
9889 * Software event: cpu wall time clock
9892 static void cpu_clock_event_update(struct perf_event
*event
)
9897 now
= local_clock();
9898 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9899 local64_add(now
- prev
, &event
->count
);
9902 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
9904 local64_set(&event
->hw
.prev_count
, local_clock());
9905 perf_swevent_start_hrtimer(event
);
9908 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
9910 perf_swevent_cancel_hrtimer(event
);
9911 cpu_clock_event_update(event
);
9914 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
9916 if (flags
& PERF_EF_START
)
9917 cpu_clock_event_start(event
, flags
);
9918 perf_event_update_userpage(event
);
9923 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
9925 cpu_clock_event_stop(event
, flags
);
9928 static void cpu_clock_event_read(struct perf_event
*event
)
9930 cpu_clock_event_update(event
);
9933 static int cpu_clock_event_init(struct perf_event
*event
)
9935 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9938 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
9942 * no branch sampling for software events
9944 if (has_branch_stack(event
))
9947 perf_swevent_init_hrtimer(event
);
9952 static struct pmu perf_cpu_clock
= {
9953 .task_ctx_nr
= perf_sw_context
,
9955 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9957 .event_init
= cpu_clock_event_init
,
9958 .add
= cpu_clock_event_add
,
9959 .del
= cpu_clock_event_del
,
9960 .start
= cpu_clock_event_start
,
9961 .stop
= cpu_clock_event_stop
,
9962 .read
= cpu_clock_event_read
,
9966 * Software event: task time clock
9969 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
9974 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9976 local64_add(delta
, &event
->count
);
9979 static void task_clock_event_start(struct perf_event
*event
, int flags
)
9981 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
9982 perf_swevent_start_hrtimer(event
);
9985 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
9987 perf_swevent_cancel_hrtimer(event
);
9988 task_clock_event_update(event
, event
->ctx
->time
);
9991 static int task_clock_event_add(struct perf_event
*event
, int flags
)
9993 if (flags
& PERF_EF_START
)
9994 task_clock_event_start(event
, flags
);
9995 perf_event_update_userpage(event
);
10000 static void task_clock_event_del(struct perf_event
*event
, int flags
)
10002 task_clock_event_stop(event
, PERF_EF_UPDATE
);
10005 static void task_clock_event_read(struct perf_event
*event
)
10007 u64 now
= perf_clock();
10008 u64 delta
= now
- event
->ctx
->timestamp
;
10009 u64 time
= event
->ctx
->time
+ delta
;
10011 task_clock_event_update(event
, time
);
10014 static int task_clock_event_init(struct perf_event
*event
)
10016 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
10019 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
10023 * no branch sampling for software events
10025 if (has_branch_stack(event
))
10026 return -EOPNOTSUPP
;
10028 perf_swevent_init_hrtimer(event
);
10033 static struct pmu perf_task_clock
= {
10034 .task_ctx_nr
= perf_sw_context
,
10036 .capabilities
= PERF_PMU_CAP_NO_NMI
,
10038 .event_init
= task_clock_event_init
,
10039 .add
= task_clock_event_add
,
10040 .del
= task_clock_event_del
,
10041 .start
= task_clock_event_start
,
10042 .stop
= task_clock_event_stop
,
10043 .read
= task_clock_event_read
,
10046 static void perf_pmu_nop_void(struct pmu
*pmu
)
10050 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
10054 static int perf_pmu_nop_int(struct pmu
*pmu
)
10059 static int perf_event_nop_int(struct perf_event
*event
, u64 value
)
10064 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
10066 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
10068 __this_cpu_write(nop_txn_flags
, flags
);
10070 if (flags
& ~PERF_PMU_TXN_ADD
)
10073 perf_pmu_disable(pmu
);
10076 static int perf_pmu_commit_txn(struct pmu
*pmu
)
10078 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10080 __this_cpu_write(nop_txn_flags
, 0);
10082 if (flags
& ~PERF_PMU_TXN_ADD
)
10085 perf_pmu_enable(pmu
);
10089 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
10091 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
10093 __this_cpu_write(nop_txn_flags
, 0);
10095 if (flags
& ~PERF_PMU_TXN_ADD
)
10098 perf_pmu_enable(pmu
);
10101 static int perf_event_idx_default(struct perf_event
*event
)
10107 * Ensures all contexts with the same task_ctx_nr have the same
10108 * pmu_cpu_context too.
10110 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
10117 list_for_each_entry(pmu
, &pmus
, entry
) {
10118 if (pmu
->task_ctx_nr
== ctxn
)
10119 return pmu
->pmu_cpu_context
;
10125 static void free_pmu_context(struct pmu
*pmu
)
10128 * Static contexts such as perf_sw_context have a global lifetime
10129 * and may be shared between different PMUs. Avoid freeing them
10130 * when a single PMU is going away.
10132 if (pmu
->task_ctx_nr
> perf_invalid_context
)
10135 free_percpu(pmu
->pmu_cpu_context
);
10139 * Let userspace know that this PMU supports address range filtering:
10141 static ssize_t
nr_addr_filters_show(struct device
*dev
,
10142 struct device_attribute
*attr
,
10145 struct pmu
*pmu
= dev_get_drvdata(dev
);
10147 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
10149 DEVICE_ATTR_RO(nr_addr_filters
);
10151 static struct idr pmu_idr
;
10154 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
10156 struct pmu
*pmu
= dev_get_drvdata(dev
);
10158 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
10160 static DEVICE_ATTR_RO(type
);
10163 perf_event_mux_interval_ms_show(struct device
*dev
,
10164 struct device_attribute
*attr
,
10167 struct pmu
*pmu
= dev_get_drvdata(dev
);
10169 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
10172 static DEFINE_MUTEX(mux_interval_mutex
);
10175 perf_event_mux_interval_ms_store(struct device
*dev
,
10176 struct device_attribute
*attr
,
10177 const char *buf
, size_t count
)
10179 struct pmu
*pmu
= dev_get_drvdata(dev
);
10180 int timer
, cpu
, ret
;
10182 ret
= kstrtoint(buf
, 0, &timer
);
10189 /* same value, noting to do */
10190 if (timer
== pmu
->hrtimer_interval_ms
)
10193 mutex_lock(&mux_interval_mutex
);
10194 pmu
->hrtimer_interval_ms
= timer
;
10196 /* update all cpuctx for this PMU */
10198 for_each_online_cpu(cpu
) {
10199 struct perf_cpu_context
*cpuctx
;
10200 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10201 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
10203 cpu_function_call(cpu
,
10204 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
10206 cpus_read_unlock();
10207 mutex_unlock(&mux_interval_mutex
);
10211 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
10213 static struct attribute
*pmu_dev_attrs
[] = {
10214 &dev_attr_type
.attr
,
10215 &dev_attr_perf_event_mux_interval_ms
.attr
,
10218 ATTRIBUTE_GROUPS(pmu_dev
);
10220 static int pmu_bus_running
;
10221 static struct bus_type pmu_bus
= {
10222 .name
= "event_source",
10223 .dev_groups
= pmu_dev_groups
,
10226 static void pmu_dev_release(struct device
*dev
)
10231 static int pmu_dev_alloc(struct pmu
*pmu
)
10235 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
10239 pmu
->dev
->groups
= pmu
->attr_groups
;
10240 device_initialize(pmu
->dev
);
10241 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
10245 dev_set_drvdata(pmu
->dev
, pmu
);
10246 pmu
->dev
->bus
= &pmu_bus
;
10247 pmu
->dev
->release
= pmu_dev_release
;
10248 ret
= device_add(pmu
->dev
);
10252 /* For PMUs with address filters, throw in an extra attribute: */
10253 if (pmu
->nr_addr_filters
)
10254 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10259 if (pmu
->attr_update
)
10260 ret
= sysfs_update_groups(&pmu
->dev
->kobj
, pmu
->attr_update
);
10269 device_del(pmu
->dev
);
10272 put_device(pmu
->dev
);
10276 static struct lock_class_key cpuctx_mutex
;
10277 static struct lock_class_key cpuctx_lock
;
10279 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
10281 int cpu
, ret
, max
= PERF_TYPE_MAX
;
10283 mutex_lock(&pmus_lock
);
10285 pmu
->pmu_disable_count
= alloc_percpu(int);
10286 if (!pmu
->pmu_disable_count
)
10294 if (type
!= PERF_TYPE_SOFTWARE
) {
10298 ret
= idr_alloc(&pmu_idr
, pmu
, max
, 0, GFP_KERNEL
);
10302 WARN_ON(type
>= 0 && ret
!= type
);
10308 if (pmu_bus_running
) {
10309 ret
= pmu_dev_alloc(pmu
);
10315 if (pmu
->task_ctx_nr
== perf_hw_context
) {
10316 static int hw_context_taken
= 0;
10319 * Other than systems with heterogeneous CPUs, it never makes
10320 * sense for two PMUs to share perf_hw_context. PMUs which are
10321 * uncore must use perf_invalid_context.
10323 if (WARN_ON_ONCE(hw_context_taken
&&
10324 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
10325 pmu
->task_ctx_nr
= perf_invalid_context
;
10327 hw_context_taken
= 1;
10330 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
10331 if (pmu
->pmu_cpu_context
)
10332 goto got_cpu_context
;
10335 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
10336 if (!pmu
->pmu_cpu_context
)
10339 for_each_possible_cpu(cpu
) {
10340 struct perf_cpu_context
*cpuctx
;
10342 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10343 __perf_event_init_context(&cpuctx
->ctx
);
10344 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
10345 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
10346 cpuctx
->ctx
.pmu
= pmu
;
10347 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
10349 __perf_mux_hrtimer_init(cpuctx
, cpu
);
10353 if (!pmu
->start_txn
) {
10354 if (pmu
->pmu_enable
) {
10356 * If we have pmu_enable/pmu_disable calls, install
10357 * transaction stubs that use that to try and batch
10358 * hardware accesses.
10360 pmu
->start_txn
= perf_pmu_start_txn
;
10361 pmu
->commit_txn
= perf_pmu_commit_txn
;
10362 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
10364 pmu
->start_txn
= perf_pmu_nop_txn
;
10365 pmu
->commit_txn
= perf_pmu_nop_int
;
10366 pmu
->cancel_txn
= perf_pmu_nop_void
;
10370 if (!pmu
->pmu_enable
) {
10371 pmu
->pmu_enable
= perf_pmu_nop_void
;
10372 pmu
->pmu_disable
= perf_pmu_nop_void
;
10375 if (!pmu
->check_period
)
10376 pmu
->check_period
= perf_event_nop_int
;
10378 if (!pmu
->event_idx
)
10379 pmu
->event_idx
= perf_event_idx_default
;
10382 * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
10383 * since these cannot be in the IDR. This way the linear search
10384 * is fast, provided a valid software event is provided.
10386 if (type
== PERF_TYPE_SOFTWARE
|| !name
)
10387 list_add_rcu(&pmu
->entry
, &pmus
);
10389 list_add_tail_rcu(&pmu
->entry
, &pmus
);
10391 atomic_set(&pmu
->exclusive_cnt
, 0);
10394 mutex_unlock(&pmus_lock
);
10399 device_del(pmu
->dev
);
10400 put_device(pmu
->dev
);
10403 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
10404 idr_remove(&pmu_idr
, pmu
->type
);
10407 free_percpu(pmu
->pmu_disable_count
);
10410 EXPORT_SYMBOL_GPL(perf_pmu_register
);
10412 void perf_pmu_unregister(struct pmu
*pmu
)
10414 mutex_lock(&pmus_lock
);
10415 list_del_rcu(&pmu
->entry
);
10418 * We dereference the pmu list under both SRCU and regular RCU, so
10419 * synchronize against both of those.
10421 synchronize_srcu(&pmus_srcu
);
10424 free_percpu(pmu
->pmu_disable_count
);
10425 if (pmu
->type
!= PERF_TYPE_SOFTWARE
)
10426 idr_remove(&pmu_idr
, pmu
->type
);
10427 if (pmu_bus_running
) {
10428 if (pmu
->nr_addr_filters
)
10429 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10430 device_del(pmu
->dev
);
10431 put_device(pmu
->dev
);
10433 free_pmu_context(pmu
);
10434 mutex_unlock(&pmus_lock
);
10436 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
10438 static inline bool has_extended_regs(struct perf_event
*event
)
10440 return (event
->attr
.sample_regs_user
& PERF_REG_EXTENDED_MASK
) ||
10441 (event
->attr
.sample_regs_intr
& PERF_REG_EXTENDED_MASK
);
10444 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
10446 struct perf_event_context
*ctx
= NULL
;
10449 if (!try_module_get(pmu
->module
))
10453 * A number of pmu->event_init() methods iterate the sibling_list to,
10454 * for example, validate if the group fits on the PMU. Therefore,
10455 * if this is a sibling event, acquire the ctx->mutex to protect
10456 * the sibling_list.
10458 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
10460 * This ctx->mutex can nest when we're called through
10461 * inheritance. See the perf_event_ctx_lock_nested() comment.
10463 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
10464 SINGLE_DEPTH_NESTING
);
10469 ret
= pmu
->event_init(event
);
10472 perf_event_ctx_unlock(event
->group_leader
, ctx
);
10475 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXTENDED_REGS
) &&
10476 has_extended_regs(event
))
10479 if (pmu
->capabilities
& PERF_PMU_CAP_NO_EXCLUDE
&&
10480 event_has_any_exclude_flag(event
))
10483 if (ret
&& event
->destroy
)
10484 event
->destroy(event
);
10488 module_put(pmu
->module
);
10493 static struct pmu
*perf_init_event(struct perf_event
*event
)
10495 int idx
, type
, ret
;
10498 idx
= srcu_read_lock(&pmus_srcu
);
10500 /* Try parent's PMU first: */
10501 if (event
->parent
&& event
->parent
->pmu
) {
10502 pmu
= event
->parent
->pmu
;
10503 ret
= perf_try_init_event(pmu
, event
);
10509 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
10510 * are often aliases for PERF_TYPE_RAW.
10512 type
= event
->attr
.type
;
10513 if (type
== PERF_TYPE_HARDWARE
|| type
== PERF_TYPE_HW_CACHE
)
10514 type
= PERF_TYPE_RAW
;
10518 pmu
= idr_find(&pmu_idr
, type
);
10521 ret
= perf_try_init_event(pmu
, event
);
10522 if (ret
== -ENOENT
&& event
->attr
.type
!= type
) {
10523 type
= event
->attr
.type
;
10528 pmu
= ERR_PTR(ret
);
10533 list_for_each_entry_rcu(pmu
, &pmus
, entry
, lockdep_is_held(&pmus_srcu
)) {
10534 ret
= perf_try_init_event(pmu
, event
);
10538 if (ret
!= -ENOENT
) {
10539 pmu
= ERR_PTR(ret
);
10543 pmu
= ERR_PTR(-ENOENT
);
10545 srcu_read_unlock(&pmus_srcu
, idx
);
10550 static void attach_sb_event(struct perf_event
*event
)
10552 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
10554 raw_spin_lock(&pel
->lock
);
10555 list_add_rcu(&event
->sb_list
, &pel
->list
);
10556 raw_spin_unlock(&pel
->lock
);
10560 * We keep a list of all !task (and therefore per-cpu) events
10561 * that need to receive side-band records.
10563 * This avoids having to scan all the various PMU per-cpu contexts
10564 * looking for them.
10566 static void account_pmu_sb_event(struct perf_event
*event
)
10568 if (is_sb_event(event
))
10569 attach_sb_event(event
);
10572 static void account_event_cpu(struct perf_event
*event
, int cpu
)
10577 if (is_cgroup_event(event
))
10578 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
10581 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
10582 static void account_freq_event_nohz(void)
10584 #ifdef CONFIG_NO_HZ_FULL
10585 /* Lock so we don't race with concurrent unaccount */
10586 spin_lock(&nr_freq_lock
);
10587 if (atomic_inc_return(&nr_freq_events
) == 1)
10588 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
10589 spin_unlock(&nr_freq_lock
);
10593 static void account_freq_event(void)
10595 if (tick_nohz_full_enabled())
10596 account_freq_event_nohz();
10598 atomic_inc(&nr_freq_events
);
10602 static void account_event(struct perf_event
*event
)
10609 if (event
->attach_state
& PERF_ATTACH_TASK
)
10611 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
10612 atomic_inc(&nr_mmap_events
);
10613 if (event
->attr
.comm
)
10614 atomic_inc(&nr_comm_events
);
10615 if (event
->attr
.namespaces
)
10616 atomic_inc(&nr_namespaces_events
);
10617 if (event
->attr
.task
)
10618 atomic_inc(&nr_task_events
);
10619 if (event
->attr
.freq
)
10620 account_freq_event();
10621 if (event
->attr
.context_switch
) {
10622 atomic_inc(&nr_switch_events
);
10625 if (has_branch_stack(event
))
10627 if (is_cgroup_event(event
))
10629 if (event
->attr
.ksymbol
)
10630 atomic_inc(&nr_ksymbol_events
);
10631 if (event
->attr
.bpf_event
)
10632 atomic_inc(&nr_bpf_events
);
10636 * We need the mutex here because static_branch_enable()
10637 * must complete *before* the perf_sched_count increment
10640 if (atomic_inc_not_zero(&perf_sched_count
))
10643 mutex_lock(&perf_sched_mutex
);
10644 if (!atomic_read(&perf_sched_count
)) {
10645 static_branch_enable(&perf_sched_events
);
10647 * Guarantee that all CPUs observe they key change and
10648 * call the perf scheduling hooks before proceeding to
10649 * install events that need them.
10654 * Now that we have waited for the sync_sched(), allow further
10655 * increments to by-pass the mutex.
10657 atomic_inc(&perf_sched_count
);
10658 mutex_unlock(&perf_sched_mutex
);
10662 account_event_cpu(event
, event
->cpu
);
10664 account_pmu_sb_event(event
);
10668 * Allocate and initialize an event structure
10670 static struct perf_event
*
10671 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
10672 struct task_struct
*task
,
10673 struct perf_event
*group_leader
,
10674 struct perf_event
*parent_event
,
10675 perf_overflow_handler_t overflow_handler
,
10676 void *context
, int cgroup_fd
)
10679 struct perf_event
*event
;
10680 struct hw_perf_event
*hwc
;
10681 long err
= -EINVAL
;
10683 if ((unsigned)cpu
>= nr_cpu_ids
) {
10684 if (!task
|| cpu
!= -1)
10685 return ERR_PTR(-EINVAL
);
10688 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
10690 return ERR_PTR(-ENOMEM
);
10693 * Single events are their own group leaders, with an
10694 * empty sibling list:
10697 group_leader
= event
;
10699 mutex_init(&event
->child_mutex
);
10700 INIT_LIST_HEAD(&event
->child_list
);
10702 INIT_LIST_HEAD(&event
->event_entry
);
10703 INIT_LIST_HEAD(&event
->sibling_list
);
10704 INIT_LIST_HEAD(&event
->active_list
);
10705 init_event_group(event
);
10706 INIT_LIST_HEAD(&event
->rb_entry
);
10707 INIT_LIST_HEAD(&event
->active_entry
);
10708 INIT_LIST_HEAD(&event
->addr_filters
.list
);
10709 INIT_HLIST_NODE(&event
->hlist_entry
);
10712 init_waitqueue_head(&event
->waitq
);
10713 event
->pending_disable
= -1;
10714 init_irq_work(&event
->pending
, perf_pending_event
);
10716 mutex_init(&event
->mmap_mutex
);
10717 raw_spin_lock_init(&event
->addr_filters
.lock
);
10719 atomic_long_set(&event
->refcount
, 1);
10721 event
->attr
= *attr
;
10722 event
->group_leader
= group_leader
;
10726 event
->parent
= parent_event
;
10728 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
10729 event
->id
= atomic64_inc_return(&perf_event_id
);
10731 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10734 event
->attach_state
= PERF_ATTACH_TASK
;
10736 * XXX pmu::event_init needs to know what task to account to
10737 * and we cannot use the ctx information because we need the
10738 * pmu before we get a ctx.
10740 event
->hw
.target
= get_task_struct(task
);
10743 event
->clock
= &local_clock
;
10745 event
->clock
= parent_event
->clock
;
10747 if (!overflow_handler
&& parent_event
) {
10748 overflow_handler
= parent_event
->overflow_handler
;
10749 context
= parent_event
->overflow_handler_context
;
10750 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
10751 if (overflow_handler
== bpf_overflow_handler
) {
10752 struct bpf_prog
*prog
= parent_event
->prog
;
10754 bpf_prog_inc(prog
);
10755 event
->prog
= prog
;
10756 event
->orig_overflow_handler
=
10757 parent_event
->orig_overflow_handler
;
10762 if (overflow_handler
) {
10763 event
->overflow_handler
= overflow_handler
;
10764 event
->overflow_handler_context
= context
;
10765 } else if (is_write_backward(event
)){
10766 event
->overflow_handler
= perf_event_output_backward
;
10767 event
->overflow_handler_context
= NULL
;
10769 event
->overflow_handler
= perf_event_output_forward
;
10770 event
->overflow_handler_context
= NULL
;
10773 perf_event__state_init(event
);
10778 hwc
->sample_period
= attr
->sample_period
;
10779 if (attr
->freq
&& attr
->sample_freq
)
10780 hwc
->sample_period
= 1;
10781 hwc
->last_period
= hwc
->sample_period
;
10783 local64_set(&hwc
->period_left
, hwc
->sample_period
);
10786 * We currently do not support PERF_SAMPLE_READ on inherited events.
10787 * See perf_output_read().
10789 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
10792 if (!has_branch_stack(event
))
10793 event
->attr
.branch_sample_type
= 0;
10795 if (cgroup_fd
!= -1) {
10796 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
10801 pmu
= perf_init_event(event
);
10803 err
= PTR_ERR(pmu
);
10808 * Disallow uncore-cgroup events, they don't make sense as the cgroup will
10809 * be different on other CPUs in the uncore mask.
10811 if (pmu
->task_ctx_nr
== perf_invalid_context
&& cgroup_fd
!= -1) {
10816 if (event
->attr
.aux_output
&&
10817 !(pmu
->capabilities
& PERF_PMU_CAP_AUX_OUTPUT
)) {
10822 err
= exclusive_event_init(event
);
10826 if (has_addr_filter(event
)) {
10827 event
->addr_filter_ranges
= kcalloc(pmu
->nr_addr_filters
,
10828 sizeof(struct perf_addr_filter_range
),
10830 if (!event
->addr_filter_ranges
) {
10836 * Clone the parent's vma offsets: they are valid until exec()
10837 * even if the mm is not shared with the parent.
10839 if (event
->parent
) {
10840 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
10842 raw_spin_lock_irq(&ifh
->lock
);
10843 memcpy(event
->addr_filter_ranges
,
10844 event
->parent
->addr_filter_ranges
,
10845 pmu
->nr_addr_filters
* sizeof(struct perf_addr_filter_range
));
10846 raw_spin_unlock_irq(&ifh
->lock
);
10849 /* force hw sync on the address filters */
10850 event
->addr_filters_gen
= 1;
10853 if (!event
->parent
) {
10854 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
10855 err
= get_callchain_buffers(attr
->sample_max_stack
);
10857 goto err_addr_filters
;
10861 err
= security_perf_event_alloc(event
);
10863 goto err_callchain_buffer
;
10865 /* symmetric to unaccount_event() in _free_event() */
10866 account_event(event
);
10870 err_callchain_buffer
:
10871 if (!event
->parent
) {
10872 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
10873 put_callchain_buffers();
10876 kfree(event
->addr_filter_ranges
);
10879 exclusive_event_destroy(event
);
10882 if (event
->destroy
)
10883 event
->destroy(event
);
10884 module_put(pmu
->module
);
10886 if (is_cgroup_event(event
))
10887 perf_detach_cgroup(event
);
10889 put_pid_ns(event
->ns
);
10890 if (event
->hw
.target
)
10891 put_task_struct(event
->hw
.target
);
10894 return ERR_PTR(err
);
10897 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
10898 struct perf_event_attr
*attr
)
10903 /* Zero the full structure, so that a short copy will be nice. */
10904 memset(attr
, 0, sizeof(*attr
));
10906 ret
= get_user(size
, &uattr
->size
);
10910 /* ABI compatibility quirk: */
10912 size
= PERF_ATTR_SIZE_VER0
;
10913 if (size
< PERF_ATTR_SIZE_VER0
|| size
> PAGE_SIZE
)
10916 ret
= copy_struct_from_user(attr
, sizeof(*attr
), uattr
, size
);
10925 if (attr
->__reserved_1
|| attr
->__reserved_2
|| attr
->__reserved_3
)
10928 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
10931 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
10934 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
10935 u64 mask
= attr
->branch_sample_type
;
10937 /* only using defined bits */
10938 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
10941 /* at least one branch bit must be set */
10942 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
10945 /* propagate priv level, when not set for branch */
10946 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
10948 /* exclude_kernel checked on syscall entry */
10949 if (!attr
->exclude_kernel
)
10950 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
10952 if (!attr
->exclude_user
)
10953 mask
|= PERF_SAMPLE_BRANCH_USER
;
10955 if (!attr
->exclude_hv
)
10956 mask
|= PERF_SAMPLE_BRANCH_HV
;
10958 * adjust user setting (for HW filter setup)
10960 attr
->branch_sample_type
= mask
;
10962 /* privileged levels capture (kernel, hv): check permissions */
10963 if (mask
& PERF_SAMPLE_BRANCH_PERM_PLM
) {
10964 ret
= perf_allow_kernel(attr
);
10970 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
10971 ret
= perf_reg_validate(attr
->sample_regs_user
);
10976 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
10977 if (!arch_perf_have_user_stack_dump())
10981 * We have __u32 type for the size, but so far
10982 * we can only use __u16 as maximum due to the
10983 * __u16 sample size limit.
10985 if (attr
->sample_stack_user
>= USHRT_MAX
)
10987 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
10991 if (!attr
->sample_max_stack
)
10992 attr
->sample_max_stack
= sysctl_perf_event_max_stack
;
10994 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
10995 ret
= perf_reg_validate(attr
->sample_regs_intr
);
11000 put_user(sizeof(*attr
), &uattr
->size
);
11006 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
11008 struct perf_buffer
*rb
= NULL
;
11014 /* don't allow circular references */
11015 if (event
== output_event
)
11019 * Don't allow cross-cpu buffers
11021 if (output_event
->cpu
!= event
->cpu
)
11025 * If its not a per-cpu rb, it must be the same task.
11027 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
11031 * Mixing clocks in the same buffer is trouble you don't need.
11033 if (output_event
->clock
!= event
->clock
)
11037 * Either writing ring buffer from beginning or from end.
11038 * Mixing is not allowed.
11040 if (is_write_backward(output_event
) != is_write_backward(event
))
11044 * If both events generate aux data, they must be on the same PMU
11046 if (has_aux(event
) && has_aux(output_event
) &&
11047 event
->pmu
!= output_event
->pmu
)
11051 mutex_lock(&event
->mmap_mutex
);
11052 /* Can't redirect output if we've got an active mmap() */
11053 if (atomic_read(&event
->mmap_count
))
11056 if (output_event
) {
11057 /* get the rb we want to redirect to */
11058 rb
= ring_buffer_get(output_event
);
11063 ring_buffer_attach(event
, rb
);
11067 mutex_unlock(&event
->mmap_mutex
);
11073 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
11079 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
11082 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
11084 bool nmi_safe
= false;
11087 case CLOCK_MONOTONIC
:
11088 event
->clock
= &ktime_get_mono_fast_ns
;
11092 case CLOCK_MONOTONIC_RAW
:
11093 event
->clock
= &ktime_get_raw_fast_ns
;
11097 case CLOCK_REALTIME
:
11098 event
->clock
= &ktime_get_real_ns
;
11101 case CLOCK_BOOTTIME
:
11102 event
->clock
= &ktime_get_boottime_ns
;
11106 event
->clock
= &ktime_get_clocktai_ns
;
11113 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
11120 * Variation on perf_event_ctx_lock_nested(), except we take two context
11123 static struct perf_event_context
*
11124 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
11125 struct perf_event_context
*ctx
)
11127 struct perf_event_context
*gctx
;
11131 gctx
= READ_ONCE(group_leader
->ctx
);
11132 if (!refcount_inc_not_zero(&gctx
->refcount
)) {
11138 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
11140 if (group_leader
->ctx
!= gctx
) {
11141 mutex_unlock(&ctx
->mutex
);
11142 mutex_unlock(&gctx
->mutex
);
11151 * sys_perf_event_open - open a performance event, associate it to a task/cpu
11153 * @attr_uptr: event_id type attributes for monitoring/sampling
11156 * @group_fd: group leader event fd
11158 SYSCALL_DEFINE5(perf_event_open
,
11159 struct perf_event_attr __user
*, attr_uptr
,
11160 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
11162 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
11163 struct perf_event
*event
, *sibling
;
11164 struct perf_event_attr attr
;
11165 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
11166 struct file
*event_file
= NULL
;
11167 struct fd group
= {NULL
, 0};
11168 struct task_struct
*task
= NULL
;
11171 int move_group
= 0;
11173 int f_flags
= O_RDWR
;
11174 int cgroup_fd
= -1;
11176 /* for future expandability... */
11177 if (flags
& ~PERF_FLAG_ALL
)
11180 /* Do we allow access to perf_event_open(2) ? */
11181 err
= security_perf_event_open(&attr
, PERF_SECURITY_OPEN
);
11185 err
= perf_copy_attr(attr_uptr
, &attr
);
11189 if (!attr
.exclude_kernel
) {
11190 err
= perf_allow_kernel(&attr
);
11195 if (attr
.namespaces
) {
11196 if (!capable(CAP_SYS_ADMIN
))
11201 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
11204 if (attr
.sample_period
& (1ULL << 63))
11208 /* Only privileged users can get physical addresses */
11209 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
)) {
11210 err
= perf_allow_kernel(&attr
);
11215 err
= security_locked_down(LOCKDOWN_PERF
);
11216 if (err
&& (attr
.sample_type
& PERF_SAMPLE_REGS_INTR
))
11217 /* REGS_INTR can leak data, lockdown must prevent this */
11223 * In cgroup mode, the pid argument is used to pass the fd
11224 * opened to the cgroup directory in cgroupfs. The cpu argument
11225 * designates the cpu on which to monitor threads from that
11228 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
11231 if (flags
& PERF_FLAG_FD_CLOEXEC
)
11232 f_flags
|= O_CLOEXEC
;
11234 event_fd
= get_unused_fd_flags(f_flags
);
11238 if (group_fd
!= -1) {
11239 err
= perf_fget_light(group_fd
, &group
);
11242 group_leader
= group
.file
->private_data
;
11243 if (flags
& PERF_FLAG_FD_OUTPUT
)
11244 output_event
= group_leader
;
11245 if (flags
& PERF_FLAG_FD_NO_GROUP
)
11246 group_leader
= NULL
;
11249 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
11250 task
= find_lively_task_by_vpid(pid
);
11251 if (IS_ERR(task
)) {
11252 err
= PTR_ERR(task
);
11257 if (task
&& group_leader
&&
11258 group_leader
->attr
.inherit
!= attr
.inherit
) {
11264 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
11269 * Reuse ptrace permission checks for now.
11271 * We must hold cred_guard_mutex across this and any potential
11272 * perf_install_in_context() call for this new event to
11273 * serialize against exec() altering our credentials (and the
11274 * perf_event_exit_task() that could imply).
11277 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
11281 if (flags
& PERF_FLAG_PID_CGROUP
)
11284 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
11285 NULL
, NULL
, cgroup_fd
);
11286 if (IS_ERR(event
)) {
11287 err
= PTR_ERR(event
);
11291 if (is_sampling_event(event
)) {
11292 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
11299 * Special case software events and allow them to be part of
11300 * any hardware group.
11304 if (attr
.use_clockid
) {
11305 err
= perf_event_set_clock(event
, attr
.clockid
);
11310 if (pmu
->task_ctx_nr
== perf_sw_context
)
11311 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
11313 if (group_leader
) {
11314 if (is_software_event(event
) &&
11315 !in_software_context(group_leader
)) {
11317 * If the event is a sw event, but the group_leader
11318 * is on hw context.
11320 * Allow the addition of software events to hw
11321 * groups, this is safe because software events
11322 * never fail to schedule.
11324 pmu
= group_leader
->ctx
->pmu
;
11325 } else if (!is_software_event(event
) &&
11326 is_software_event(group_leader
) &&
11327 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11329 * In case the group is a pure software group, and we
11330 * try to add a hardware event, move the whole group to
11331 * the hardware context.
11338 * Get the target context (task or percpu):
11340 ctx
= find_get_context(pmu
, task
, event
);
11342 err
= PTR_ERR(ctx
);
11347 * Look up the group leader (we will attach this event to it):
11349 if (group_leader
) {
11353 * Do not allow a recursive hierarchy (this new sibling
11354 * becoming part of another group-sibling):
11356 if (group_leader
->group_leader
!= group_leader
)
11359 /* All events in a group should have the same clock */
11360 if (group_leader
->clock
!= event
->clock
)
11364 * Make sure we're both events for the same CPU;
11365 * grouping events for different CPUs is broken; since
11366 * you can never concurrently schedule them anyhow.
11368 if (group_leader
->cpu
!= event
->cpu
)
11372 * Make sure we're both on the same task, or both
11375 if (group_leader
->ctx
->task
!= ctx
->task
)
11379 * Do not allow to attach to a group in a different task
11380 * or CPU context. If we're moving SW events, we'll fix
11381 * this up later, so allow that.
11383 if (!move_group
&& group_leader
->ctx
!= ctx
)
11387 * Only a group leader can be exclusive or pinned
11389 if (attr
.exclusive
|| attr
.pinned
)
11393 if (output_event
) {
11394 err
= perf_event_set_output(event
, output_event
);
11399 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
11401 if (IS_ERR(event_file
)) {
11402 err
= PTR_ERR(event_file
);
11408 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
11410 if (gctx
->task
== TASK_TOMBSTONE
) {
11416 * Check if we raced against another sys_perf_event_open() call
11417 * moving the software group underneath us.
11419 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11421 * If someone moved the group out from under us, check
11422 * if this new event wound up on the same ctx, if so
11423 * its the regular !move_group case, otherwise fail.
11429 perf_event_ctx_unlock(group_leader
, gctx
);
11435 * Failure to create exclusive events returns -EBUSY.
11438 if (!exclusive_event_installable(group_leader
, ctx
))
11441 for_each_sibling_event(sibling
, group_leader
) {
11442 if (!exclusive_event_installable(sibling
, ctx
))
11446 mutex_lock(&ctx
->mutex
);
11449 if (ctx
->task
== TASK_TOMBSTONE
) {
11454 if (!perf_event_validate_size(event
)) {
11461 * Check if the @cpu we're creating an event for is online.
11463 * We use the perf_cpu_context::ctx::mutex to serialize against
11464 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11466 struct perf_cpu_context
*cpuctx
=
11467 container_of(ctx
, struct perf_cpu_context
, ctx
);
11469 if (!cpuctx
->online
) {
11475 if (perf_need_aux_event(event
) && !perf_get_aux_event(event
, group_leader
)) {
11481 * Must be under the same ctx::mutex as perf_install_in_context(),
11482 * because we need to serialize with concurrent event creation.
11484 if (!exclusive_event_installable(event
, ctx
)) {
11489 WARN_ON_ONCE(ctx
->parent_ctx
);
11492 * This is the point on no return; we cannot fail hereafter. This is
11493 * where we start modifying current state.
11498 * See perf_event_ctx_lock() for comments on the details
11499 * of swizzling perf_event::ctx.
11501 perf_remove_from_context(group_leader
, 0);
11504 for_each_sibling_event(sibling
, group_leader
) {
11505 perf_remove_from_context(sibling
, 0);
11510 * Wait for everybody to stop referencing the events through
11511 * the old lists, before installing it on new lists.
11516 * Install the group siblings before the group leader.
11518 * Because a group leader will try and install the entire group
11519 * (through the sibling list, which is still in-tact), we can
11520 * end up with siblings installed in the wrong context.
11522 * By installing siblings first we NO-OP because they're not
11523 * reachable through the group lists.
11525 for_each_sibling_event(sibling
, group_leader
) {
11526 perf_event__state_init(sibling
);
11527 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
11532 * Removing from the context ends up with disabled
11533 * event. What we want here is event in the initial
11534 * startup state, ready to be add into new context.
11536 perf_event__state_init(group_leader
);
11537 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
11542 * Precalculate sample_data sizes; do while holding ctx::mutex such
11543 * that we're serialized against further additions and before
11544 * perf_install_in_context() which is the point the event is active and
11545 * can use these values.
11547 perf_event__header_size(event
);
11548 perf_event__id_header_size(event
);
11550 event
->owner
= current
;
11552 perf_install_in_context(ctx
, event
, event
->cpu
);
11553 perf_unpin_context(ctx
);
11556 perf_event_ctx_unlock(group_leader
, gctx
);
11557 mutex_unlock(&ctx
->mutex
);
11560 mutex_unlock(&task
->signal
->cred_guard_mutex
);
11561 put_task_struct(task
);
11564 mutex_lock(¤t
->perf_event_mutex
);
11565 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
11566 mutex_unlock(¤t
->perf_event_mutex
);
11569 * Drop the reference on the group_event after placing the
11570 * new event on the sibling_list. This ensures destruction
11571 * of the group leader will find the pointer to itself in
11572 * perf_group_detach().
11575 fd_install(event_fd
, event_file
);
11580 perf_event_ctx_unlock(group_leader
, gctx
);
11581 mutex_unlock(&ctx
->mutex
);
11585 perf_unpin_context(ctx
);
11589 * If event_file is set, the fput() above will have called ->release()
11590 * and that will take care of freeing the event.
11596 mutex_unlock(&task
->signal
->cred_guard_mutex
);
11599 put_task_struct(task
);
11603 put_unused_fd(event_fd
);
11608 * perf_event_create_kernel_counter
11610 * @attr: attributes of the counter to create
11611 * @cpu: cpu in which the counter is bound
11612 * @task: task to profile (NULL for percpu)
11614 struct perf_event
*
11615 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
11616 struct task_struct
*task
,
11617 perf_overflow_handler_t overflow_handler
,
11620 struct perf_event_context
*ctx
;
11621 struct perf_event
*event
;
11625 * Grouping is not supported for kernel events, neither is 'AUX',
11626 * make sure the caller's intentions are adjusted.
11628 if (attr
->aux_output
)
11629 return ERR_PTR(-EINVAL
);
11631 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
11632 overflow_handler
, context
, -1);
11633 if (IS_ERR(event
)) {
11634 err
= PTR_ERR(event
);
11638 /* Mark owner so we could distinguish it from user events. */
11639 event
->owner
= TASK_TOMBSTONE
;
11642 * Get the target context (task or percpu):
11644 ctx
= find_get_context(event
->pmu
, task
, event
);
11646 err
= PTR_ERR(ctx
);
11650 WARN_ON_ONCE(ctx
->parent_ctx
);
11651 mutex_lock(&ctx
->mutex
);
11652 if (ctx
->task
== TASK_TOMBSTONE
) {
11659 * Check if the @cpu we're creating an event for is online.
11661 * We use the perf_cpu_context::ctx::mutex to serialize against
11662 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11664 struct perf_cpu_context
*cpuctx
=
11665 container_of(ctx
, struct perf_cpu_context
, ctx
);
11666 if (!cpuctx
->online
) {
11672 if (!exclusive_event_installable(event
, ctx
)) {
11677 perf_install_in_context(ctx
, event
, event
->cpu
);
11678 perf_unpin_context(ctx
);
11679 mutex_unlock(&ctx
->mutex
);
11684 mutex_unlock(&ctx
->mutex
);
11685 perf_unpin_context(ctx
);
11690 return ERR_PTR(err
);
11692 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
11694 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
11696 struct perf_event_context
*src_ctx
;
11697 struct perf_event_context
*dst_ctx
;
11698 struct perf_event
*event
, *tmp
;
11701 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
11702 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
11705 * See perf_event_ctx_lock() for comments on the details
11706 * of swizzling perf_event::ctx.
11708 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
11709 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
11711 perf_remove_from_context(event
, 0);
11712 unaccount_event_cpu(event
, src_cpu
);
11714 list_add(&event
->migrate_entry
, &events
);
11718 * Wait for the events to quiesce before re-instating them.
11723 * Re-instate events in 2 passes.
11725 * Skip over group leaders and only install siblings on this first
11726 * pass, siblings will not get enabled without a leader, however a
11727 * leader will enable its siblings, even if those are still on the old
11730 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
11731 if (event
->group_leader
== event
)
11734 list_del(&event
->migrate_entry
);
11735 if (event
->state
>= PERF_EVENT_STATE_OFF
)
11736 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11737 account_event_cpu(event
, dst_cpu
);
11738 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
11743 * Once all the siblings are setup properly, install the group leaders
11746 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
11747 list_del(&event
->migrate_entry
);
11748 if (event
->state
>= PERF_EVENT_STATE_OFF
)
11749 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11750 account_event_cpu(event
, dst_cpu
);
11751 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
11754 mutex_unlock(&dst_ctx
->mutex
);
11755 mutex_unlock(&src_ctx
->mutex
);
11757 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
11759 static void sync_child_event(struct perf_event
*child_event
,
11760 struct task_struct
*child
)
11762 struct perf_event
*parent_event
= child_event
->parent
;
11765 if (child_event
->attr
.inherit_stat
)
11766 perf_event_read_event(child_event
, child
);
11768 child_val
= perf_event_count(child_event
);
11771 * Add back the child's count to the parent's count:
11773 atomic64_add(child_val
, &parent_event
->child_count
);
11774 atomic64_add(child_event
->total_time_enabled
,
11775 &parent_event
->child_total_time_enabled
);
11776 atomic64_add(child_event
->total_time_running
,
11777 &parent_event
->child_total_time_running
);
11781 perf_event_exit_event(struct perf_event
*child_event
,
11782 struct perf_event_context
*child_ctx
,
11783 struct task_struct
*child
)
11785 struct perf_event
*parent_event
= child_event
->parent
;
11788 * Do not destroy the 'original' grouping; because of the context
11789 * switch optimization the original events could've ended up in a
11790 * random child task.
11792 * If we were to destroy the original group, all group related
11793 * operations would cease to function properly after this random
11796 * Do destroy all inherited groups, we don't care about those
11797 * and being thorough is better.
11799 raw_spin_lock_irq(&child_ctx
->lock
);
11800 WARN_ON_ONCE(child_ctx
->is_active
);
11803 perf_group_detach(child_event
);
11804 list_del_event(child_event
, child_ctx
);
11805 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
11806 raw_spin_unlock_irq(&child_ctx
->lock
);
11809 * Parent events are governed by their filedesc, retain them.
11811 if (!parent_event
) {
11812 perf_event_wakeup(child_event
);
11816 * Child events can be cleaned up.
11819 sync_child_event(child_event
, child
);
11822 * Remove this event from the parent's list
11824 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
11825 mutex_lock(&parent_event
->child_mutex
);
11826 list_del_init(&child_event
->child_list
);
11827 mutex_unlock(&parent_event
->child_mutex
);
11830 * Kick perf_poll() for is_event_hup().
11832 perf_event_wakeup(parent_event
);
11833 free_event(child_event
);
11834 put_event(parent_event
);
11837 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
11839 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
11840 struct perf_event
*child_event
, *next
;
11842 WARN_ON_ONCE(child
!= current
);
11844 child_ctx
= perf_pin_task_context(child
, ctxn
);
11849 * In order to reduce the amount of tricky in ctx tear-down, we hold
11850 * ctx::mutex over the entire thing. This serializes against almost
11851 * everything that wants to access the ctx.
11853 * The exception is sys_perf_event_open() /
11854 * perf_event_create_kernel_count() which does find_get_context()
11855 * without ctx::mutex (it cannot because of the move_group double mutex
11856 * lock thing). See the comments in perf_install_in_context().
11858 mutex_lock(&child_ctx
->mutex
);
11861 * In a single ctx::lock section, de-schedule the events and detach the
11862 * context from the task such that we cannot ever get it scheduled back
11865 raw_spin_lock_irq(&child_ctx
->lock
);
11866 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
11869 * Now that the context is inactive, destroy the task <-> ctx relation
11870 * and mark the context dead.
11872 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
11873 put_ctx(child_ctx
); /* cannot be last */
11874 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
11875 put_task_struct(current
); /* cannot be last */
11877 clone_ctx
= unclone_ctx(child_ctx
);
11878 raw_spin_unlock_irq(&child_ctx
->lock
);
11881 put_ctx(clone_ctx
);
11884 * Report the task dead after unscheduling the events so that we
11885 * won't get any samples after PERF_RECORD_EXIT. We can however still
11886 * get a few PERF_RECORD_READ events.
11888 perf_event_task(child
, child_ctx
, 0);
11890 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
11891 perf_event_exit_event(child_event
, child_ctx
, child
);
11893 mutex_unlock(&child_ctx
->mutex
);
11895 put_ctx(child_ctx
);
11899 * When a child task exits, feed back event values to parent events.
11901 * Can be called with cred_guard_mutex held when called from
11902 * install_exec_creds().
11904 void perf_event_exit_task(struct task_struct
*child
)
11906 struct perf_event
*event
, *tmp
;
11909 mutex_lock(&child
->perf_event_mutex
);
11910 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
11912 list_del_init(&event
->owner_entry
);
11915 * Ensure the list deletion is visible before we clear
11916 * the owner, closes a race against perf_release() where
11917 * we need to serialize on the owner->perf_event_mutex.
11919 smp_store_release(&event
->owner
, NULL
);
11921 mutex_unlock(&child
->perf_event_mutex
);
11923 for_each_task_context_nr(ctxn
)
11924 perf_event_exit_task_context(child
, ctxn
);
11927 * The perf_event_exit_task_context calls perf_event_task
11928 * with child's task_ctx, which generates EXIT events for
11929 * child contexts and sets child->perf_event_ctxp[] to NULL.
11930 * At this point we need to send EXIT events to cpu contexts.
11932 perf_event_task(child
, NULL
, 0);
11935 static void perf_free_event(struct perf_event
*event
,
11936 struct perf_event_context
*ctx
)
11938 struct perf_event
*parent
= event
->parent
;
11940 if (WARN_ON_ONCE(!parent
))
11943 mutex_lock(&parent
->child_mutex
);
11944 list_del_init(&event
->child_list
);
11945 mutex_unlock(&parent
->child_mutex
);
11949 raw_spin_lock_irq(&ctx
->lock
);
11950 perf_group_detach(event
);
11951 list_del_event(event
, ctx
);
11952 raw_spin_unlock_irq(&ctx
->lock
);
11957 * Free a context as created by inheritance by perf_event_init_task() below,
11958 * used by fork() in case of fail.
11960 * Even though the task has never lived, the context and events have been
11961 * exposed through the child_list, so we must take care tearing it all down.
11963 void perf_event_free_task(struct task_struct
*task
)
11965 struct perf_event_context
*ctx
;
11966 struct perf_event
*event
, *tmp
;
11969 for_each_task_context_nr(ctxn
) {
11970 ctx
= task
->perf_event_ctxp
[ctxn
];
11974 mutex_lock(&ctx
->mutex
);
11975 raw_spin_lock_irq(&ctx
->lock
);
11977 * Destroy the task <-> ctx relation and mark the context dead.
11979 * This is important because even though the task hasn't been
11980 * exposed yet the context has been (through child_list).
11982 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
11983 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
11984 put_task_struct(task
); /* cannot be last */
11985 raw_spin_unlock_irq(&ctx
->lock
);
11987 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
11988 perf_free_event(event
, ctx
);
11990 mutex_unlock(&ctx
->mutex
);
11993 * perf_event_release_kernel() could've stolen some of our
11994 * child events and still have them on its free_list. In that
11995 * case we must wait for these events to have been freed (in
11996 * particular all their references to this task must've been
11999 * Without this copy_process() will unconditionally free this
12000 * task (irrespective of its reference count) and
12001 * _free_event()'s put_task_struct(event->hw.target) will be a
12004 * Wait for all events to drop their context reference.
12006 wait_var_event(&ctx
->refcount
, refcount_read(&ctx
->refcount
) == 1);
12007 put_ctx(ctx
); /* must be last */
12011 void perf_event_delayed_put(struct task_struct
*task
)
12015 for_each_task_context_nr(ctxn
)
12016 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
12019 struct file
*perf_event_get(unsigned int fd
)
12021 struct file
*file
= fget(fd
);
12023 return ERR_PTR(-EBADF
);
12025 if (file
->f_op
!= &perf_fops
) {
12027 return ERR_PTR(-EBADF
);
12033 const struct perf_event
*perf_get_event(struct file
*file
)
12035 if (file
->f_op
!= &perf_fops
)
12036 return ERR_PTR(-EINVAL
);
12038 return file
->private_data
;
12041 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
12044 return ERR_PTR(-EINVAL
);
12046 return &event
->attr
;
12050 * Inherit an event from parent task to child task.
12053 * - valid pointer on success
12054 * - NULL for orphaned events
12055 * - IS_ERR() on error
12057 static struct perf_event
*
12058 inherit_event(struct perf_event
*parent_event
,
12059 struct task_struct
*parent
,
12060 struct perf_event_context
*parent_ctx
,
12061 struct task_struct
*child
,
12062 struct perf_event
*group_leader
,
12063 struct perf_event_context
*child_ctx
)
12065 enum perf_event_state parent_state
= parent_event
->state
;
12066 struct perf_event
*child_event
;
12067 unsigned long flags
;
12070 * Instead of creating recursive hierarchies of events,
12071 * we link inherited events back to the original parent,
12072 * which has a filp for sure, which we use as the reference
12075 if (parent_event
->parent
)
12076 parent_event
= parent_event
->parent
;
12078 child_event
= perf_event_alloc(&parent_event
->attr
,
12081 group_leader
, parent_event
,
12083 if (IS_ERR(child_event
))
12084 return child_event
;
12087 if ((child_event
->attach_state
& PERF_ATTACH_TASK_DATA
) &&
12088 !child_ctx
->task_ctx_data
) {
12089 struct pmu
*pmu
= child_event
->pmu
;
12091 child_ctx
->task_ctx_data
= kzalloc(pmu
->task_ctx_size
,
12093 if (!child_ctx
->task_ctx_data
) {
12094 free_event(child_event
);
12095 return ERR_PTR(-ENOMEM
);
12100 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
12101 * must be under the same lock in order to serialize against
12102 * perf_event_release_kernel(), such that either we must observe
12103 * is_orphaned_event() or they will observe us on the child_list.
12105 mutex_lock(&parent_event
->child_mutex
);
12106 if (is_orphaned_event(parent_event
) ||
12107 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
12108 mutex_unlock(&parent_event
->child_mutex
);
12109 /* task_ctx_data is freed with child_ctx */
12110 free_event(child_event
);
12114 get_ctx(child_ctx
);
12117 * Make the child state follow the state of the parent event,
12118 * not its attr.disabled bit. We hold the parent's mutex,
12119 * so we won't race with perf_event_{en, dis}able_family.
12121 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
12122 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
12124 child_event
->state
= PERF_EVENT_STATE_OFF
;
12126 if (parent_event
->attr
.freq
) {
12127 u64 sample_period
= parent_event
->hw
.sample_period
;
12128 struct hw_perf_event
*hwc
= &child_event
->hw
;
12130 hwc
->sample_period
= sample_period
;
12131 hwc
->last_period
= sample_period
;
12133 local64_set(&hwc
->period_left
, sample_period
);
12136 child_event
->ctx
= child_ctx
;
12137 child_event
->overflow_handler
= parent_event
->overflow_handler
;
12138 child_event
->overflow_handler_context
12139 = parent_event
->overflow_handler_context
;
12142 * Precalculate sample_data sizes
12144 perf_event__header_size(child_event
);
12145 perf_event__id_header_size(child_event
);
12148 * Link it up in the child's context:
12150 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
12151 add_event_to_ctx(child_event
, child_ctx
);
12152 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
12155 * Link this into the parent event's child list
12157 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
12158 mutex_unlock(&parent_event
->child_mutex
);
12160 return child_event
;
12164 * Inherits an event group.
12166 * This will quietly suppress orphaned events; !inherit_event() is not an error.
12167 * This matches with perf_event_release_kernel() removing all child events.
12173 static int inherit_group(struct perf_event
*parent_event
,
12174 struct task_struct
*parent
,
12175 struct perf_event_context
*parent_ctx
,
12176 struct task_struct
*child
,
12177 struct perf_event_context
*child_ctx
)
12179 struct perf_event
*leader
;
12180 struct perf_event
*sub
;
12181 struct perf_event
*child_ctr
;
12183 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
12184 child
, NULL
, child_ctx
);
12185 if (IS_ERR(leader
))
12186 return PTR_ERR(leader
);
12188 * @leader can be NULL here because of is_orphaned_event(). In this
12189 * case inherit_event() will create individual events, similar to what
12190 * perf_group_detach() would do anyway.
12192 for_each_sibling_event(sub
, parent_event
) {
12193 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
12194 child
, leader
, child_ctx
);
12195 if (IS_ERR(child_ctr
))
12196 return PTR_ERR(child_ctr
);
12198 if (sub
->aux_event
== parent_event
&& child_ctr
&&
12199 !perf_get_aux_event(child_ctr
, leader
))
12206 * Creates the child task context and tries to inherit the event-group.
12208 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
12209 * inherited_all set when we 'fail' to inherit an orphaned event; this is
12210 * consistent with perf_event_release_kernel() removing all child events.
12217 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
12218 struct perf_event_context
*parent_ctx
,
12219 struct task_struct
*child
, int ctxn
,
12220 int *inherited_all
)
12223 struct perf_event_context
*child_ctx
;
12225 if (!event
->attr
.inherit
) {
12226 *inherited_all
= 0;
12230 child_ctx
= child
->perf_event_ctxp
[ctxn
];
12233 * This is executed from the parent task context, so
12234 * inherit events that have been marked for cloning.
12235 * First allocate and initialize a context for the
12238 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
12242 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
12245 ret
= inherit_group(event
, parent
, parent_ctx
,
12249 *inherited_all
= 0;
12255 * Initialize the perf_event context in task_struct
12257 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
12259 struct perf_event_context
*child_ctx
, *parent_ctx
;
12260 struct perf_event_context
*cloned_ctx
;
12261 struct perf_event
*event
;
12262 struct task_struct
*parent
= current
;
12263 int inherited_all
= 1;
12264 unsigned long flags
;
12267 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
12271 * If the parent's context is a clone, pin it so it won't get
12272 * swapped under us.
12274 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
12279 * No need to check if parent_ctx != NULL here; since we saw
12280 * it non-NULL earlier, the only reason for it to become NULL
12281 * is if we exit, and since we're currently in the middle of
12282 * a fork we can't be exiting at the same time.
12286 * Lock the parent list. No need to lock the child - not PID
12287 * hashed yet and not running, so nobody can access it.
12289 mutex_lock(&parent_ctx
->mutex
);
12292 * We dont have to disable NMIs - we are only looking at
12293 * the list, not manipulating it:
12295 perf_event_groups_for_each(event
, &parent_ctx
->pinned_groups
) {
12296 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12297 child
, ctxn
, &inherited_all
);
12303 * We can't hold ctx->lock when iterating the ->flexible_group list due
12304 * to allocations, but we need to prevent rotation because
12305 * rotate_ctx() will change the list from interrupt context.
12307 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12308 parent_ctx
->rotate_disable
= 1;
12309 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12311 perf_event_groups_for_each(event
, &parent_ctx
->flexible_groups
) {
12312 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12313 child
, ctxn
, &inherited_all
);
12318 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12319 parent_ctx
->rotate_disable
= 0;
12321 child_ctx
= child
->perf_event_ctxp
[ctxn
];
12323 if (child_ctx
&& inherited_all
) {
12325 * Mark the child context as a clone of the parent
12326 * context, or of whatever the parent is a clone of.
12328 * Note that if the parent is a clone, the holding of
12329 * parent_ctx->lock avoids it from being uncloned.
12331 cloned_ctx
= parent_ctx
->parent_ctx
;
12333 child_ctx
->parent_ctx
= cloned_ctx
;
12334 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
12336 child_ctx
->parent_ctx
= parent_ctx
;
12337 child_ctx
->parent_gen
= parent_ctx
->generation
;
12339 get_ctx(child_ctx
->parent_ctx
);
12342 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12344 mutex_unlock(&parent_ctx
->mutex
);
12346 perf_unpin_context(parent_ctx
);
12347 put_ctx(parent_ctx
);
12353 * Initialize the perf_event context in task_struct
12355 int perf_event_init_task(struct task_struct
*child
)
12359 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
12360 mutex_init(&child
->perf_event_mutex
);
12361 INIT_LIST_HEAD(&child
->perf_event_list
);
12363 for_each_task_context_nr(ctxn
) {
12364 ret
= perf_event_init_context(child
, ctxn
);
12366 perf_event_free_task(child
);
12374 static void __init
perf_event_init_all_cpus(void)
12376 struct swevent_htable
*swhash
;
12379 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
12381 for_each_possible_cpu(cpu
) {
12382 swhash
= &per_cpu(swevent_htable
, cpu
);
12383 mutex_init(&swhash
->hlist_mutex
);
12384 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
12386 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
12387 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
12389 #ifdef CONFIG_CGROUP_PERF
12390 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
12392 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
12396 static void perf_swevent_init_cpu(unsigned int cpu
)
12398 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
12400 mutex_lock(&swhash
->hlist_mutex
);
12401 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
12402 struct swevent_hlist
*hlist
;
12404 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
12406 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
12408 mutex_unlock(&swhash
->hlist_mutex
);
12411 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
12412 static void __perf_event_exit_context(void *__info
)
12414 struct perf_event_context
*ctx
= __info
;
12415 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
12416 struct perf_event
*event
;
12418 raw_spin_lock(&ctx
->lock
);
12419 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
12420 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
12421 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
12422 raw_spin_unlock(&ctx
->lock
);
12425 static void perf_event_exit_cpu_context(int cpu
)
12427 struct perf_cpu_context
*cpuctx
;
12428 struct perf_event_context
*ctx
;
12431 mutex_lock(&pmus_lock
);
12432 list_for_each_entry(pmu
, &pmus
, entry
) {
12433 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12434 ctx
= &cpuctx
->ctx
;
12436 mutex_lock(&ctx
->mutex
);
12437 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
12438 cpuctx
->online
= 0;
12439 mutex_unlock(&ctx
->mutex
);
12441 cpumask_clear_cpu(cpu
, perf_online_mask
);
12442 mutex_unlock(&pmus_lock
);
12446 static void perf_event_exit_cpu_context(int cpu
) { }
12450 int perf_event_init_cpu(unsigned int cpu
)
12452 struct perf_cpu_context
*cpuctx
;
12453 struct perf_event_context
*ctx
;
12456 perf_swevent_init_cpu(cpu
);
12458 mutex_lock(&pmus_lock
);
12459 cpumask_set_cpu(cpu
, perf_online_mask
);
12460 list_for_each_entry(pmu
, &pmus
, entry
) {
12461 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12462 ctx
= &cpuctx
->ctx
;
12464 mutex_lock(&ctx
->mutex
);
12465 cpuctx
->online
= 1;
12466 mutex_unlock(&ctx
->mutex
);
12468 mutex_unlock(&pmus_lock
);
12473 int perf_event_exit_cpu(unsigned int cpu
)
12475 perf_event_exit_cpu_context(cpu
);
12480 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
12484 for_each_online_cpu(cpu
)
12485 perf_event_exit_cpu(cpu
);
12491 * Run the perf reboot notifier at the very last possible moment so that
12492 * the generic watchdog code runs as long as possible.
12494 static struct notifier_block perf_reboot_notifier
= {
12495 .notifier_call
= perf_reboot
,
12496 .priority
= INT_MIN
,
12499 void __init
perf_event_init(void)
12503 idr_init(&pmu_idr
);
12505 perf_event_init_all_cpus();
12506 init_srcu_struct(&pmus_srcu
);
12507 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
12508 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
12509 perf_pmu_register(&perf_task_clock
, NULL
, -1);
12510 perf_tp_register();
12511 perf_event_init_cpu(smp_processor_id());
12512 register_reboot_notifier(&perf_reboot_notifier
);
12514 ret
= init_hw_breakpoint();
12515 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
12518 * Build time assertion that we keep the data_head at the intended
12519 * location. IOW, validation we got the __reserved[] size right.
12521 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
12525 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
12528 struct perf_pmu_events_attr
*pmu_attr
=
12529 container_of(attr
, struct perf_pmu_events_attr
, attr
);
12531 if (pmu_attr
->event_str
)
12532 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
12536 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
12538 static int __init
perf_event_sysfs_init(void)
12543 mutex_lock(&pmus_lock
);
12545 ret
= bus_register(&pmu_bus
);
12549 list_for_each_entry(pmu
, &pmus
, entry
) {
12550 if (!pmu
->name
|| pmu
->type
< 0)
12553 ret
= pmu_dev_alloc(pmu
);
12554 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
12556 pmu_bus_running
= 1;
12560 mutex_unlock(&pmus_lock
);
12564 device_initcall(perf_event_sysfs_init
);
12566 #ifdef CONFIG_CGROUP_PERF
12567 static struct cgroup_subsys_state
*
12568 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
12570 struct perf_cgroup
*jc
;
12572 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
12574 return ERR_PTR(-ENOMEM
);
12576 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
12579 return ERR_PTR(-ENOMEM
);
12585 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
12587 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
12589 free_percpu(jc
->info
);
12593 static int __perf_cgroup_move(void *info
)
12595 struct task_struct
*task
= info
;
12597 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
12602 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
12604 struct task_struct
*task
;
12605 struct cgroup_subsys_state
*css
;
12607 cgroup_taskset_for_each(task
, css
, tset
)
12608 task_function_call(task
, __perf_cgroup_move
, task
);
12611 struct cgroup_subsys perf_event_cgrp_subsys
= {
12612 .css_alloc
= perf_cgroup_css_alloc
,
12613 .css_free
= perf_cgroup_css_free
,
12614 .attach
= perf_cgroup_attach
,
12616 * Implicitly enable on dfl hierarchy so that perf events can
12617 * always be filtered by cgroup2 path as long as perf_event
12618 * controller is not mounted on a legacy hierarchy.
12620 .implicit_on_dfl
= true,
12623 #endif /* CONFIG_CGROUP_PERF */