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Commit | Line | Data |
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0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
fadfe7be JO |
52 | static struct workqueue_struct *perf_wq; |
53 | ||
272325c4 PZ |
54 | typedef int (*remote_function_f)(void *); |
55 | ||
fe4b04fa | 56 | struct remote_function_call { |
e7e7ee2e | 57 | struct task_struct *p; |
272325c4 | 58 | remote_function_f func; |
e7e7ee2e IM |
59 | void *info; |
60 | int ret; | |
fe4b04fa PZ |
61 | }; |
62 | ||
63 | static void remote_function(void *data) | |
64 | { | |
65 | struct remote_function_call *tfc = data; | |
66 | struct task_struct *p = tfc->p; | |
67 | ||
68 | if (p) { | |
69 | tfc->ret = -EAGAIN; | |
70 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
71 | return; | |
72 | } | |
73 | ||
74 | tfc->ret = tfc->func(tfc->info); | |
75 | } | |
76 | ||
77 | /** | |
78 | * task_function_call - call a function on the cpu on which a task runs | |
79 | * @p: the task to evaluate | |
80 | * @func: the function to be called | |
81 | * @info: the function call argument | |
82 | * | |
83 | * Calls the function @func when the task is currently running. This might | |
84 | * be on the current CPU, which just calls the function directly | |
85 | * | |
86 | * returns: @func return value, or | |
87 | * -ESRCH - when the process isn't running | |
88 | * -EAGAIN - when the process moved away | |
89 | */ | |
90 | static int | |
272325c4 | 91 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
92 | { |
93 | struct remote_function_call data = { | |
e7e7ee2e IM |
94 | .p = p, |
95 | .func = func, | |
96 | .info = info, | |
97 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
98 | }; |
99 | ||
100 | if (task_curr(p)) | |
101 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
102 | ||
103 | return data.ret; | |
104 | } | |
105 | ||
106 | /** | |
107 | * cpu_function_call - call a function on the cpu | |
108 | * @func: the function to be called | |
109 | * @info: the function call argument | |
110 | * | |
111 | * Calls the function @func on the remote cpu. | |
112 | * | |
113 | * returns: @func return value or -ENXIO when the cpu is offline | |
114 | */ | |
272325c4 | 115 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
116 | { |
117 | struct remote_function_call data = { | |
e7e7ee2e IM |
118 | .p = NULL, |
119 | .func = func, | |
120 | .info = info, | |
121 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
122 | }; |
123 | ||
124 | smp_call_function_single(cpu, remote_function, &data, 1); | |
125 | ||
126 | return data.ret; | |
127 | } | |
128 | ||
39a43640 PZ |
129 | /* |
130 | * On task ctx scheduling... | |
131 | * | |
132 | * When !ctx->nr_events a task context will not be scheduled. This means | |
133 | * we can disable the scheduler hooks (for performance) without leaving | |
134 | * pending task ctx state. | |
135 | * | |
136 | * This however results in two special cases: | |
137 | * | |
138 | * - removing the last event from a task ctx; this is relatively straight | |
139 | * forward and is done in __perf_remove_from_context. | |
140 | * | |
141 | * - adding the first event to a task ctx; this is tricky because we cannot | |
142 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
143 | * See perf_install_in_context(). | |
144 | * | |
145 | * This is because we need a ctx->lock serialized variable (ctx->is_active) | |
146 | * to reliably determine if a particular task/context is scheduled in. The | |
147 | * task_curr() use in task_function_call() is racy in that a remote context | |
148 | * switch is not a single atomic operation. | |
149 | * | |
150 | * As is, the situation is 'safe' because we set rq->curr before we do the | |
151 | * actual context switch. This means that task_curr() will fail early, but | |
152 | * we'll continue spinning on ctx->is_active until we've passed | |
153 | * perf_event_task_sched_out(). | |
154 | * | |
155 | * Without this ctx->lock serialized variable we could have race where we find | |
156 | * the task (and hence the context) would not be active while in fact they are. | |
157 | * | |
158 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. | |
159 | */ | |
160 | ||
0017960f PZ |
161 | static void event_function_call(struct perf_event *event, |
162 | int (*active)(void *), | |
163 | void (*inactive)(void *), | |
164 | void *data) | |
165 | { | |
166 | struct perf_event_context *ctx = event->ctx; | |
167 | struct task_struct *task = ctx->task; | |
168 | ||
169 | if (!task) { | |
170 | cpu_function_call(event->cpu, active, data); | |
171 | return; | |
172 | } | |
173 | ||
174 | again: | |
175 | if (!task_function_call(task, active, data)) | |
176 | return; | |
177 | ||
178 | raw_spin_lock_irq(&ctx->lock); | |
179 | if (ctx->is_active) { | |
180 | /* | |
181 | * Reload the task pointer, it might have been changed by | |
182 | * a concurrent perf_event_context_sched_out(). | |
183 | */ | |
184 | task = ctx->task; | |
185 | raw_spin_unlock_irq(&ctx->lock); | |
186 | goto again; | |
187 | } | |
188 | inactive(data); | |
189 | raw_spin_unlock_irq(&ctx->lock); | |
190 | } | |
191 | ||
f8697762 JO |
192 | #define EVENT_OWNER_KERNEL ((void *) -1) |
193 | ||
194 | static bool is_kernel_event(struct perf_event *event) | |
195 | { | |
196 | return event->owner == EVENT_OWNER_KERNEL; | |
197 | } | |
198 | ||
e5d1367f SE |
199 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
200 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
201 | PERF_FLAG_PID_CGROUP |\ |
202 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 203 | |
bce38cd5 SE |
204 | /* |
205 | * branch priv levels that need permission checks | |
206 | */ | |
207 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
208 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
209 | PERF_SAMPLE_BRANCH_HV) | |
210 | ||
0b3fcf17 SE |
211 | enum event_type_t { |
212 | EVENT_FLEXIBLE = 0x1, | |
213 | EVENT_PINNED = 0x2, | |
214 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
215 | }; | |
216 | ||
e5d1367f SE |
217 | /* |
218 | * perf_sched_events : >0 events exist | |
219 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
220 | */ | |
c5905afb | 221 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 222 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 223 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 224 | |
cdd6c482 IM |
225 | static atomic_t nr_mmap_events __read_mostly; |
226 | static atomic_t nr_comm_events __read_mostly; | |
227 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 228 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 229 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 230 | |
108b02cf PZ |
231 | static LIST_HEAD(pmus); |
232 | static DEFINE_MUTEX(pmus_lock); | |
233 | static struct srcu_struct pmus_srcu; | |
234 | ||
0764771d | 235 | /* |
cdd6c482 | 236 | * perf event paranoia level: |
0fbdea19 IM |
237 | * -1 - not paranoid at all |
238 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 239 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 240 | * 2 - disallow kernel profiling for unpriv |
0764771d | 241 | */ |
cdd6c482 | 242 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 243 | |
20443384 FW |
244 | /* Minimum for 512 kiB + 1 user control page */ |
245 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
246 | |
247 | /* | |
cdd6c482 | 248 | * max perf event sample rate |
df58ab24 | 249 | */ |
14c63f17 DH |
250 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
251 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
252 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
253 | ||
254 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
255 | ||
256 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
257 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
258 | ||
d9494cb4 PZ |
259 | static int perf_sample_allowed_ns __read_mostly = |
260 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 261 | |
18ab2cd3 | 262 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
263 | { |
264 | u64 tmp = perf_sample_period_ns; | |
265 | ||
266 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 267 | do_div(tmp, 100); |
d9494cb4 | 268 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 269 | } |
163ec435 | 270 | |
9e630205 SE |
271 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
272 | ||
163ec435 PZ |
273 | int perf_proc_update_handler(struct ctl_table *table, int write, |
274 | void __user *buffer, size_t *lenp, | |
275 | loff_t *ppos) | |
276 | { | |
723478c8 | 277 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
278 | |
279 | if (ret || !write) | |
280 | return ret; | |
281 | ||
282 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
283 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
284 | update_perf_cpu_limits(); | |
285 | ||
286 | return 0; | |
287 | } | |
288 | ||
289 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
290 | ||
291 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
292 | void __user *buffer, size_t *lenp, | |
293 | loff_t *ppos) | |
294 | { | |
295 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
296 | ||
297 | if (ret || !write) | |
298 | return ret; | |
299 | ||
300 | update_perf_cpu_limits(); | |
163ec435 PZ |
301 | |
302 | return 0; | |
303 | } | |
1ccd1549 | 304 | |
14c63f17 DH |
305 | /* |
306 | * perf samples are done in some very critical code paths (NMIs). | |
307 | * If they take too much CPU time, the system can lock up and not | |
308 | * get any real work done. This will drop the sample rate when | |
309 | * we detect that events are taking too long. | |
310 | */ | |
311 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 312 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 313 | |
6a02ad66 | 314 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 315 | { |
6a02ad66 | 316 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 317 | u64 avg_local_sample_len; |
e5302920 | 318 | u64 local_samples_len; |
6a02ad66 | 319 | |
4a32fea9 | 320 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
321 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
322 | ||
323 | printk_ratelimited(KERN_WARNING | |
324 | "perf interrupt took too long (%lld > %lld), lowering " | |
325 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 326 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
327 | sysctl_perf_event_sample_rate); |
328 | } | |
329 | ||
330 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
331 | ||
332 | void perf_sample_event_took(u64 sample_len_ns) | |
333 | { | |
d9494cb4 | 334 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
335 | u64 avg_local_sample_len; |
336 | u64 local_samples_len; | |
14c63f17 | 337 | |
d9494cb4 | 338 | if (allowed_ns == 0) |
14c63f17 DH |
339 | return; |
340 | ||
341 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 342 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
343 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
344 | local_samples_len += sample_len_ns; | |
4a32fea9 | 345 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
346 | |
347 | /* | |
348 | * note: this will be biased artifically low until we have | |
349 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
350 | * from having to maintain a count. | |
351 | */ | |
352 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
353 | ||
d9494cb4 | 354 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
355 | return; |
356 | ||
357 | if (max_samples_per_tick <= 1) | |
358 | return; | |
359 | ||
360 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
361 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
362 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
363 | ||
14c63f17 | 364 | update_perf_cpu_limits(); |
6a02ad66 | 365 | |
cd578abb PZ |
366 | if (!irq_work_queue(&perf_duration_work)) { |
367 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
368 | "kernel.perf_event_max_sample_rate to %d\n", | |
369 | avg_local_sample_len, allowed_ns >> 1, | |
370 | sysctl_perf_event_sample_rate); | |
371 | } | |
14c63f17 DH |
372 | } |
373 | ||
cdd6c482 | 374 | static atomic64_t perf_event_id; |
a96bbc16 | 375 | |
0b3fcf17 SE |
376 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
377 | enum event_type_t event_type); | |
378 | ||
379 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
380 | enum event_type_t event_type, |
381 | struct task_struct *task); | |
382 | ||
383 | static void update_context_time(struct perf_event_context *ctx); | |
384 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 385 | |
cdd6c482 | 386 | void __weak perf_event_print_debug(void) { } |
0793a61d | 387 | |
84c79910 | 388 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 389 | { |
84c79910 | 390 | return "pmu"; |
0793a61d TG |
391 | } |
392 | ||
0b3fcf17 SE |
393 | static inline u64 perf_clock(void) |
394 | { | |
395 | return local_clock(); | |
396 | } | |
397 | ||
34f43927 PZ |
398 | static inline u64 perf_event_clock(struct perf_event *event) |
399 | { | |
400 | return event->clock(); | |
401 | } | |
402 | ||
e5d1367f SE |
403 | static inline struct perf_cpu_context * |
404 | __get_cpu_context(struct perf_event_context *ctx) | |
405 | { | |
406 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
407 | } | |
408 | ||
facc4307 PZ |
409 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, |
410 | struct perf_event_context *ctx) | |
411 | { | |
412 | raw_spin_lock(&cpuctx->ctx.lock); | |
413 | if (ctx) | |
414 | raw_spin_lock(&ctx->lock); | |
415 | } | |
416 | ||
417 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
418 | struct perf_event_context *ctx) | |
419 | { | |
420 | if (ctx) | |
421 | raw_spin_unlock(&ctx->lock); | |
422 | raw_spin_unlock(&cpuctx->ctx.lock); | |
423 | } | |
424 | ||
e5d1367f SE |
425 | #ifdef CONFIG_CGROUP_PERF |
426 | ||
e5d1367f SE |
427 | static inline bool |
428 | perf_cgroup_match(struct perf_event *event) | |
429 | { | |
430 | struct perf_event_context *ctx = event->ctx; | |
431 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
432 | ||
ef824fa1 TH |
433 | /* @event doesn't care about cgroup */ |
434 | if (!event->cgrp) | |
435 | return true; | |
436 | ||
437 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
438 | if (!cpuctx->cgrp) | |
439 | return false; | |
440 | ||
441 | /* | |
442 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
443 | * also enabled for all its descendant cgroups. If @cpuctx's | |
444 | * cgroup is a descendant of @event's (the test covers identity | |
445 | * case), it's a match. | |
446 | */ | |
447 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
448 | event->cgrp->css.cgroup); | |
e5d1367f SE |
449 | } |
450 | ||
e5d1367f SE |
451 | static inline void perf_detach_cgroup(struct perf_event *event) |
452 | { | |
4e2ba650 | 453 | css_put(&event->cgrp->css); |
e5d1367f SE |
454 | event->cgrp = NULL; |
455 | } | |
456 | ||
457 | static inline int is_cgroup_event(struct perf_event *event) | |
458 | { | |
459 | return event->cgrp != NULL; | |
460 | } | |
461 | ||
462 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
463 | { | |
464 | struct perf_cgroup_info *t; | |
465 | ||
466 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
467 | return t->time; | |
468 | } | |
469 | ||
470 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
471 | { | |
472 | struct perf_cgroup_info *info; | |
473 | u64 now; | |
474 | ||
475 | now = perf_clock(); | |
476 | ||
477 | info = this_cpu_ptr(cgrp->info); | |
478 | ||
479 | info->time += now - info->timestamp; | |
480 | info->timestamp = now; | |
481 | } | |
482 | ||
483 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
484 | { | |
485 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
486 | if (cgrp_out) | |
487 | __update_cgrp_time(cgrp_out); | |
488 | } | |
489 | ||
490 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
491 | { | |
3f7cce3c SE |
492 | struct perf_cgroup *cgrp; |
493 | ||
e5d1367f | 494 | /* |
3f7cce3c SE |
495 | * ensure we access cgroup data only when needed and |
496 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 497 | */ |
3f7cce3c | 498 | if (!is_cgroup_event(event)) |
e5d1367f SE |
499 | return; |
500 | ||
614e4c4e | 501 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
502 | /* |
503 | * Do not update time when cgroup is not active | |
504 | */ | |
505 | if (cgrp == event->cgrp) | |
506 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
507 | } |
508 | ||
509 | static inline void | |
3f7cce3c SE |
510 | perf_cgroup_set_timestamp(struct task_struct *task, |
511 | struct perf_event_context *ctx) | |
e5d1367f SE |
512 | { |
513 | struct perf_cgroup *cgrp; | |
514 | struct perf_cgroup_info *info; | |
515 | ||
3f7cce3c SE |
516 | /* |
517 | * ctx->lock held by caller | |
518 | * ensure we do not access cgroup data | |
519 | * unless we have the cgroup pinned (css_get) | |
520 | */ | |
521 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
522 | return; |
523 | ||
614e4c4e | 524 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 525 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 526 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
527 | } |
528 | ||
529 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
530 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
531 | ||
532 | /* | |
533 | * reschedule events based on the cgroup constraint of task. | |
534 | * | |
535 | * mode SWOUT : schedule out everything | |
536 | * mode SWIN : schedule in based on cgroup for next | |
537 | */ | |
18ab2cd3 | 538 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
539 | { |
540 | struct perf_cpu_context *cpuctx; | |
541 | struct pmu *pmu; | |
542 | unsigned long flags; | |
543 | ||
544 | /* | |
545 | * disable interrupts to avoid geting nr_cgroup | |
546 | * changes via __perf_event_disable(). Also | |
547 | * avoids preemption. | |
548 | */ | |
549 | local_irq_save(flags); | |
550 | ||
551 | /* | |
552 | * we reschedule only in the presence of cgroup | |
553 | * constrained events. | |
554 | */ | |
e5d1367f SE |
555 | |
556 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 557 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
558 | if (cpuctx->unique_pmu != pmu) |
559 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 560 | |
e5d1367f SE |
561 | /* |
562 | * perf_cgroup_events says at least one | |
563 | * context on this CPU has cgroup events. | |
564 | * | |
565 | * ctx->nr_cgroups reports the number of cgroup | |
566 | * events for a context. | |
567 | */ | |
568 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
569 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
570 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
571 | |
572 | if (mode & PERF_CGROUP_SWOUT) { | |
573 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
574 | /* | |
575 | * must not be done before ctxswout due | |
576 | * to event_filter_match() in event_sched_out() | |
577 | */ | |
578 | cpuctx->cgrp = NULL; | |
579 | } | |
580 | ||
581 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 582 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
583 | /* |
584 | * set cgrp before ctxsw in to allow | |
585 | * event_filter_match() to not have to pass | |
586 | * task around | |
614e4c4e SE |
587 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
588 | * because cgorup events are only per-cpu | |
e5d1367f | 589 | */ |
614e4c4e | 590 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
591 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
592 | } | |
facc4307 PZ |
593 | perf_pmu_enable(cpuctx->ctx.pmu); |
594 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 595 | } |
e5d1367f SE |
596 | } |
597 | ||
e5d1367f SE |
598 | local_irq_restore(flags); |
599 | } | |
600 | ||
a8d757ef SE |
601 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
602 | struct task_struct *next) | |
e5d1367f | 603 | { |
a8d757ef SE |
604 | struct perf_cgroup *cgrp1; |
605 | struct perf_cgroup *cgrp2 = NULL; | |
606 | ||
ddaaf4e2 | 607 | rcu_read_lock(); |
a8d757ef SE |
608 | /* |
609 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
610 | * we do not need to pass the ctx here because we know |
611 | * we are holding the rcu lock | |
a8d757ef | 612 | */ |
614e4c4e | 613 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 614 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
615 | |
616 | /* | |
617 | * only schedule out current cgroup events if we know | |
618 | * that we are switching to a different cgroup. Otherwise, | |
619 | * do no touch the cgroup events. | |
620 | */ | |
621 | if (cgrp1 != cgrp2) | |
622 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
623 | |
624 | rcu_read_unlock(); | |
e5d1367f SE |
625 | } |
626 | ||
a8d757ef SE |
627 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
628 | struct task_struct *task) | |
e5d1367f | 629 | { |
a8d757ef SE |
630 | struct perf_cgroup *cgrp1; |
631 | struct perf_cgroup *cgrp2 = NULL; | |
632 | ||
ddaaf4e2 | 633 | rcu_read_lock(); |
a8d757ef SE |
634 | /* |
635 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
636 | * we do not need to pass the ctx here because we know |
637 | * we are holding the rcu lock | |
a8d757ef | 638 | */ |
614e4c4e | 639 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 640 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
641 | |
642 | /* | |
643 | * only need to schedule in cgroup events if we are changing | |
644 | * cgroup during ctxsw. Cgroup events were not scheduled | |
645 | * out of ctxsw out if that was not the case. | |
646 | */ | |
647 | if (cgrp1 != cgrp2) | |
648 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
649 | |
650 | rcu_read_unlock(); | |
e5d1367f SE |
651 | } |
652 | ||
653 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
654 | struct perf_event_attr *attr, | |
655 | struct perf_event *group_leader) | |
656 | { | |
657 | struct perf_cgroup *cgrp; | |
658 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
659 | struct fd f = fdget(fd); |
660 | int ret = 0; | |
e5d1367f | 661 | |
2903ff01 | 662 | if (!f.file) |
e5d1367f SE |
663 | return -EBADF; |
664 | ||
b583043e | 665 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 666 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
667 | if (IS_ERR(css)) { |
668 | ret = PTR_ERR(css); | |
669 | goto out; | |
670 | } | |
e5d1367f SE |
671 | |
672 | cgrp = container_of(css, struct perf_cgroup, css); | |
673 | event->cgrp = cgrp; | |
674 | ||
675 | /* | |
676 | * all events in a group must monitor | |
677 | * the same cgroup because a task belongs | |
678 | * to only one perf cgroup at a time | |
679 | */ | |
680 | if (group_leader && group_leader->cgrp != cgrp) { | |
681 | perf_detach_cgroup(event); | |
682 | ret = -EINVAL; | |
e5d1367f | 683 | } |
3db272c0 | 684 | out: |
2903ff01 | 685 | fdput(f); |
e5d1367f SE |
686 | return ret; |
687 | } | |
688 | ||
689 | static inline void | |
690 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
691 | { | |
692 | struct perf_cgroup_info *t; | |
693 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
694 | event->shadow_ctx_time = now - t->timestamp; | |
695 | } | |
696 | ||
697 | static inline void | |
698 | perf_cgroup_defer_enabled(struct perf_event *event) | |
699 | { | |
700 | /* | |
701 | * when the current task's perf cgroup does not match | |
702 | * the event's, we need to remember to call the | |
703 | * perf_mark_enable() function the first time a task with | |
704 | * a matching perf cgroup is scheduled in. | |
705 | */ | |
706 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
707 | event->cgrp_defer_enabled = 1; | |
708 | } | |
709 | ||
710 | static inline void | |
711 | perf_cgroup_mark_enabled(struct perf_event *event, | |
712 | struct perf_event_context *ctx) | |
713 | { | |
714 | struct perf_event *sub; | |
715 | u64 tstamp = perf_event_time(event); | |
716 | ||
717 | if (!event->cgrp_defer_enabled) | |
718 | return; | |
719 | ||
720 | event->cgrp_defer_enabled = 0; | |
721 | ||
722 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
723 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
724 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
725 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
726 | sub->cgrp_defer_enabled = 0; | |
727 | } | |
728 | } | |
729 | } | |
730 | #else /* !CONFIG_CGROUP_PERF */ | |
731 | ||
732 | static inline bool | |
733 | perf_cgroup_match(struct perf_event *event) | |
734 | { | |
735 | return true; | |
736 | } | |
737 | ||
738 | static inline void perf_detach_cgroup(struct perf_event *event) | |
739 | {} | |
740 | ||
741 | static inline int is_cgroup_event(struct perf_event *event) | |
742 | { | |
743 | return 0; | |
744 | } | |
745 | ||
746 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
747 | { | |
748 | return 0; | |
749 | } | |
750 | ||
751 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
752 | { | |
753 | } | |
754 | ||
755 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
756 | { | |
757 | } | |
758 | ||
a8d757ef SE |
759 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
760 | struct task_struct *next) | |
e5d1367f SE |
761 | { |
762 | } | |
763 | ||
a8d757ef SE |
764 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
765 | struct task_struct *task) | |
e5d1367f SE |
766 | { |
767 | } | |
768 | ||
769 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
770 | struct perf_event_attr *attr, | |
771 | struct perf_event *group_leader) | |
772 | { | |
773 | return -EINVAL; | |
774 | } | |
775 | ||
776 | static inline void | |
3f7cce3c SE |
777 | perf_cgroup_set_timestamp(struct task_struct *task, |
778 | struct perf_event_context *ctx) | |
e5d1367f SE |
779 | { |
780 | } | |
781 | ||
782 | void | |
783 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
784 | { | |
785 | } | |
786 | ||
787 | static inline void | |
788 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
789 | { | |
790 | } | |
791 | ||
792 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
793 | { | |
794 | return 0; | |
795 | } | |
796 | ||
797 | static inline void | |
798 | perf_cgroup_defer_enabled(struct perf_event *event) | |
799 | { | |
800 | } | |
801 | ||
802 | static inline void | |
803 | perf_cgroup_mark_enabled(struct perf_event *event, | |
804 | struct perf_event_context *ctx) | |
805 | { | |
806 | } | |
807 | #endif | |
808 | ||
9e630205 SE |
809 | /* |
810 | * set default to be dependent on timer tick just | |
811 | * like original code | |
812 | */ | |
813 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
814 | /* | |
815 | * function must be called with interrupts disbled | |
816 | */ | |
272325c4 | 817 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
818 | { |
819 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
820 | int rotations = 0; |
821 | ||
822 | WARN_ON(!irqs_disabled()); | |
823 | ||
824 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
825 | rotations = perf_rotate_context(cpuctx); |
826 | ||
4cfafd30 PZ |
827 | raw_spin_lock(&cpuctx->hrtimer_lock); |
828 | if (rotations) | |
9e630205 | 829 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
830 | else |
831 | cpuctx->hrtimer_active = 0; | |
832 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 833 | |
4cfafd30 | 834 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
835 | } |
836 | ||
272325c4 | 837 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 838 | { |
272325c4 | 839 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 840 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 841 | u64 interval; |
9e630205 SE |
842 | |
843 | /* no multiplexing needed for SW PMU */ | |
844 | if (pmu->task_ctx_nr == perf_sw_context) | |
845 | return; | |
846 | ||
62b85639 SE |
847 | /* |
848 | * check default is sane, if not set then force to | |
849 | * default interval (1/tick) | |
850 | */ | |
272325c4 PZ |
851 | interval = pmu->hrtimer_interval_ms; |
852 | if (interval < 1) | |
853 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 854 | |
272325c4 | 855 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 856 | |
4cfafd30 PZ |
857 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
858 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 859 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
860 | } |
861 | ||
272325c4 | 862 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 863 | { |
272325c4 | 864 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 865 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 866 | unsigned long flags; |
9e630205 SE |
867 | |
868 | /* not for SW PMU */ | |
869 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 870 | return 0; |
9e630205 | 871 | |
4cfafd30 PZ |
872 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
873 | if (!cpuctx->hrtimer_active) { | |
874 | cpuctx->hrtimer_active = 1; | |
875 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
876 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
877 | } | |
878 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 879 | |
272325c4 | 880 | return 0; |
9e630205 SE |
881 | } |
882 | ||
33696fc0 | 883 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 884 | { |
33696fc0 PZ |
885 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
886 | if (!(*count)++) | |
887 | pmu->pmu_disable(pmu); | |
9e35ad38 | 888 | } |
9e35ad38 | 889 | |
33696fc0 | 890 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 891 | { |
33696fc0 PZ |
892 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
893 | if (!--(*count)) | |
894 | pmu->pmu_enable(pmu); | |
9e35ad38 | 895 | } |
9e35ad38 | 896 | |
2fde4f94 | 897 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
898 | |
899 | /* | |
2fde4f94 MR |
900 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
901 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
902 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
903 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 904 | */ |
2fde4f94 | 905 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 906 | { |
2fde4f94 | 907 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 908 | |
e9d2b064 | 909 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 910 | |
2fde4f94 MR |
911 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
912 | ||
913 | list_add(&ctx->active_ctx_list, head); | |
914 | } | |
915 | ||
916 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
917 | { | |
918 | WARN_ON(!irqs_disabled()); | |
919 | ||
920 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
921 | ||
922 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 923 | } |
9e35ad38 | 924 | |
cdd6c482 | 925 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 926 | { |
e5289d4a | 927 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
928 | } |
929 | ||
4af57ef2 YZ |
930 | static void free_ctx(struct rcu_head *head) |
931 | { | |
932 | struct perf_event_context *ctx; | |
933 | ||
934 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
935 | kfree(ctx->task_ctx_data); | |
936 | kfree(ctx); | |
937 | } | |
938 | ||
cdd6c482 | 939 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 940 | { |
564c2b21 PM |
941 | if (atomic_dec_and_test(&ctx->refcount)) { |
942 | if (ctx->parent_ctx) | |
943 | put_ctx(ctx->parent_ctx); | |
c93f7669 PM |
944 | if (ctx->task) |
945 | put_task_struct(ctx->task); | |
4af57ef2 | 946 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 947 | } |
a63eaf34 PM |
948 | } |
949 | ||
f63a8daa PZ |
950 | /* |
951 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
952 | * perf_pmu_migrate_context() we need some magic. | |
953 | * | |
954 | * Those places that change perf_event::ctx will hold both | |
955 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
956 | * | |
8b10c5e2 PZ |
957 | * Lock ordering is by mutex address. There are two other sites where |
958 | * perf_event_context::mutex nests and those are: | |
959 | * | |
960 | * - perf_event_exit_task_context() [ child , 0 ] | |
961 | * __perf_event_exit_task() | |
962 | * sync_child_event() | |
963 | * put_event() [ parent, 1 ] | |
964 | * | |
965 | * - perf_event_init_context() [ parent, 0 ] | |
966 | * inherit_task_group() | |
967 | * inherit_group() | |
968 | * inherit_event() | |
969 | * perf_event_alloc() | |
970 | * perf_init_event() | |
971 | * perf_try_init_event() [ child , 1 ] | |
972 | * | |
973 | * While it appears there is an obvious deadlock here -- the parent and child | |
974 | * nesting levels are inverted between the two. This is in fact safe because | |
975 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
976 | * spawning task cannot (yet) exit. | |
977 | * | |
978 | * But remember that that these are parent<->child context relations, and | |
979 | * migration does not affect children, therefore these two orderings should not | |
980 | * interact. | |
f63a8daa PZ |
981 | * |
982 | * The change in perf_event::ctx does not affect children (as claimed above) | |
983 | * because the sys_perf_event_open() case will install a new event and break | |
984 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
985 | * concerned with cpuctx and that doesn't have children. | |
986 | * | |
987 | * The places that change perf_event::ctx will issue: | |
988 | * | |
989 | * perf_remove_from_context(); | |
990 | * synchronize_rcu(); | |
991 | * perf_install_in_context(); | |
992 | * | |
993 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
994 | * quiesce the event, after which we can install it in the new location. This | |
995 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
996 | * while in transit. Therefore all such accessors should also acquire | |
997 | * perf_event_context::mutex to serialize against this. | |
998 | * | |
999 | * However; because event->ctx can change while we're waiting to acquire | |
1000 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1001 | * function. | |
1002 | * | |
1003 | * Lock order: | |
1004 | * task_struct::perf_event_mutex | |
1005 | * perf_event_context::mutex | |
1006 | * perf_event_context::lock | |
1007 | * perf_event::child_mutex; | |
1008 | * perf_event::mmap_mutex | |
1009 | * mmap_sem | |
1010 | */ | |
a83fe28e PZ |
1011 | static struct perf_event_context * |
1012 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1013 | { |
1014 | struct perf_event_context *ctx; | |
1015 | ||
1016 | again: | |
1017 | rcu_read_lock(); | |
1018 | ctx = ACCESS_ONCE(event->ctx); | |
1019 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1020 | rcu_read_unlock(); | |
1021 | goto again; | |
1022 | } | |
1023 | rcu_read_unlock(); | |
1024 | ||
a83fe28e | 1025 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1026 | if (event->ctx != ctx) { |
1027 | mutex_unlock(&ctx->mutex); | |
1028 | put_ctx(ctx); | |
1029 | goto again; | |
1030 | } | |
1031 | ||
1032 | return ctx; | |
1033 | } | |
1034 | ||
a83fe28e PZ |
1035 | static inline struct perf_event_context * |
1036 | perf_event_ctx_lock(struct perf_event *event) | |
1037 | { | |
1038 | return perf_event_ctx_lock_nested(event, 0); | |
1039 | } | |
1040 | ||
f63a8daa PZ |
1041 | static void perf_event_ctx_unlock(struct perf_event *event, |
1042 | struct perf_event_context *ctx) | |
1043 | { | |
1044 | mutex_unlock(&ctx->mutex); | |
1045 | put_ctx(ctx); | |
1046 | } | |
1047 | ||
211de6eb PZ |
1048 | /* |
1049 | * This must be done under the ctx->lock, such as to serialize against | |
1050 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1051 | * calling scheduler related locks and ctx->lock nests inside those. | |
1052 | */ | |
1053 | static __must_check struct perf_event_context * | |
1054 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1055 | { |
211de6eb PZ |
1056 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1057 | ||
1058 | lockdep_assert_held(&ctx->lock); | |
1059 | ||
1060 | if (parent_ctx) | |
71a851b4 | 1061 | ctx->parent_ctx = NULL; |
5a3126d4 | 1062 | ctx->generation++; |
211de6eb PZ |
1063 | |
1064 | return parent_ctx; | |
71a851b4 PZ |
1065 | } |
1066 | ||
6844c09d ACM |
1067 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1068 | { | |
1069 | /* | |
1070 | * only top level events have the pid namespace they were created in | |
1071 | */ | |
1072 | if (event->parent) | |
1073 | event = event->parent; | |
1074 | ||
1075 | return task_tgid_nr_ns(p, event->ns); | |
1076 | } | |
1077 | ||
1078 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1079 | { | |
1080 | /* | |
1081 | * only top level events have the pid namespace they were created in | |
1082 | */ | |
1083 | if (event->parent) | |
1084 | event = event->parent; | |
1085 | ||
1086 | return task_pid_nr_ns(p, event->ns); | |
1087 | } | |
1088 | ||
7f453c24 | 1089 | /* |
cdd6c482 | 1090 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1091 | * to userspace. |
1092 | */ | |
cdd6c482 | 1093 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1094 | { |
cdd6c482 | 1095 | u64 id = event->id; |
7f453c24 | 1096 | |
cdd6c482 IM |
1097 | if (event->parent) |
1098 | id = event->parent->id; | |
7f453c24 PZ |
1099 | |
1100 | return id; | |
1101 | } | |
1102 | ||
25346b93 | 1103 | /* |
cdd6c482 | 1104 | * Get the perf_event_context for a task and lock it. |
25346b93 PM |
1105 | * This has to cope with with the fact that until it is locked, |
1106 | * the context could get moved to another task. | |
1107 | */ | |
cdd6c482 | 1108 | static struct perf_event_context * |
8dc85d54 | 1109 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1110 | { |
cdd6c482 | 1111 | struct perf_event_context *ctx; |
25346b93 | 1112 | |
9ed6060d | 1113 | retry: |
058ebd0e PZ |
1114 | /* |
1115 | * One of the few rules of preemptible RCU is that one cannot do | |
1116 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1117 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1118 | * rcu_read_unlock_special(). |
1119 | * | |
1120 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1121 | * side critical section has interrupts disabled. |
058ebd0e | 1122 | */ |
2fd59077 | 1123 | local_irq_save(*flags); |
058ebd0e | 1124 | rcu_read_lock(); |
8dc85d54 | 1125 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1126 | if (ctx) { |
1127 | /* | |
1128 | * If this context is a clone of another, it might | |
1129 | * get swapped for another underneath us by | |
cdd6c482 | 1130 | * perf_event_task_sched_out, though the |
25346b93 PM |
1131 | * rcu_read_lock() protects us from any context |
1132 | * getting freed. Lock the context and check if it | |
1133 | * got swapped before we could get the lock, and retry | |
1134 | * if so. If we locked the right context, then it | |
1135 | * can't get swapped on us any more. | |
1136 | */ | |
2fd59077 | 1137 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1138 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1139 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1140 | rcu_read_unlock(); |
2fd59077 | 1141 | local_irq_restore(*flags); |
25346b93 PM |
1142 | goto retry; |
1143 | } | |
b49a9e7e PZ |
1144 | |
1145 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1146 | raw_spin_unlock(&ctx->lock); |
b49a9e7e PZ |
1147 | ctx = NULL; |
1148 | } | |
25346b93 PM |
1149 | } |
1150 | rcu_read_unlock(); | |
2fd59077 PM |
1151 | if (!ctx) |
1152 | local_irq_restore(*flags); | |
25346b93 PM |
1153 | return ctx; |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * Get the context for a task and increment its pin_count so it | |
1158 | * can't get swapped to another task. This also increments its | |
1159 | * reference count so that the context can't get freed. | |
1160 | */ | |
8dc85d54 PZ |
1161 | static struct perf_event_context * |
1162 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1163 | { |
cdd6c482 | 1164 | struct perf_event_context *ctx; |
25346b93 PM |
1165 | unsigned long flags; |
1166 | ||
8dc85d54 | 1167 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1168 | if (ctx) { |
1169 | ++ctx->pin_count; | |
e625cce1 | 1170 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1171 | } |
1172 | return ctx; | |
1173 | } | |
1174 | ||
cdd6c482 | 1175 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1176 | { |
1177 | unsigned long flags; | |
1178 | ||
e625cce1 | 1179 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1180 | --ctx->pin_count; |
e625cce1 | 1181 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1182 | } |
1183 | ||
f67218c3 PZ |
1184 | /* |
1185 | * Update the record of the current time in a context. | |
1186 | */ | |
1187 | static void update_context_time(struct perf_event_context *ctx) | |
1188 | { | |
1189 | u64 now = perf_clock(); | |
1190 | ||
1191 | ctx->time += now - ctx->timestamp; | |
1192 | ctx->timestamp = now; | |
1193 | } | |
1194 | ||
4158755d SE |
1195 | static u64 perf_event_time(struct perf_event *event) |
1196 | { | |
1197 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1198 | |
1199 | if (is_cgroup_event(event)) | |
1200 | return perf_cgroup_event_time(event); | |
1201 | ||
4158755d SE |
1202 | return ctx ? ctx->time : 0; |
1203 | } | |
1204 | ||
f67218c3 PZ |
1205 | /* |
1206 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1207 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1208 | */ |
1209 | static void update_event_times(struct perf_event *event) | |
1210 | { | |
1211 | struct perf_event_context *ctx = event->ctx; | |
1212 | u64 run_end; | |
1213 | ||
1214 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1215 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1216 | return; | |
e5d1367f SE |
1217 | /* |
1218 | * in cgroup mode, time_enabled represents | |
1219 | * the time the event was enabled AND active | |
1220 | * tasks were in the monitored cgroup. This is | |
1221 | * independent of the activity of the context as | |
1222 | * there may be a mix of cgroup and non-cgroup events. | |
1223 | * | |
1224 | * That is why we treat cgroup events differently | |
1225 | * here. | |
1226 | */ | |
1227 | if (is_cgroup_event(event)) | |
46cd6a7f | 1228 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1229 | else if (ctx->is_active) |
1230 | run_end = ctx->time; | |
acd1d7c1 PZ |
1231 | else |
1232 | run_end = event->tstamp_stopped; | |
1233 | ||
1234 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1235 | |
1236 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1237 | run_end = event->tstamp_stopped; | |
1238 | else | |
4158755d | 1239 | run_end = perf_event_time(event); |
f67218c3 PZ |
1240 | |
1241 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1242 | |
f67218c3 PZ |
1243 | } |
1244 | ||
96c21a46 PZ |
1245 | /* |
1246 | * Update total_time_enabled and total_time_running for all events in a group. | |
1247 | */ | |
1248 | static void update_group_times(struct perf_event *leader) | |
1249 | { | |
1250 | struct perf_event *event; | |
1251 | ||
1252 | update_event_times(leader); | |
1253 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1254 | update_event_times(event); | |
1255 | } | |
1256 | ||
889ff015 FW |
1257 | static struct list_head * |
1258 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1259 | { | |
1260 | if (event->attr.pinned) | |
1261 | return &ctx->pinned_groups; | |
1262 | else | |
1263 | return &ctx->flexible_groups; | |
1264 | } | |
1265 | ||
fccc714b | 1266 | /* |
cdd6c482 | 1267 | * Add a event from the lists for its context. |
fccc714b PZ |
1268 | * Must be called with ctx->mutex and ctx->lock held. |
1269 | */ | |
04289bb9 | 1270 | static void |
cdd6c482 | 1271 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1272 | { |
c994d613 PZ |
1273 | lockdep_assert_held(&ctx->lock); |
1274 | ||
8a49542c PZ |
1275 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1276 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1277 | |
1278 | /* | |
8a49542c PZ |
1279 | * If we're a stand alone event or group leader, we go to the context |
1280 | * list, group events are kept attached to the group so that | |
1281 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1282 | */ |
8a49542c | 1283 | if (event->group_leader == event) { |
889ff015 FW |
1284 | struct list_head *list; |
1285 | ||
d6f962b5 FW |
1286 | if (is_software_event(event)) |
1287 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1288 | ||
889ff015 FW |
1289 | list = ctx_group_list(event, ctx); |
1290 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1291 | } |
592903cd | 1292 | |
08309379 | 1293 | if (is_cgroup_event(event)) |
e5d1367f | 1294 | ctx->nr_cgroups++; |
e5d1367f | 1295 | |
cdd6c482 IM |
1296 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1297 | ctx->nr_events++; | |
1298 | if (event->attr.inherit_stat) | |
bfbd3381 | 1299 | ctx->nr_stat++; |
5a3126d4 PZ |
1300 | |
1301 | ctx->generation++; | |
04289bb9 IM |
1302 | } |
1303 | ||
0231bb53 JO |
1304 | /* |
1305 | * Initialize event state based on the perf_event_attr::disabled. | |
1306 | */ | |
1307 | static inline void perf_event__state_init(struct perf_event *event) | |
1308 | { | |
1309 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1310 | PERF_EVENT_STATE_INACTIVE; | |
1311 | } | |
1312 | ||
a723968c | 1313 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1314 | { |
1315 | int entry = sizeof(u64); /* value */ | |
1316 | int size = 0; | |
1317 | int nr = 1; | |
1318 | ||
1319 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1320 | size += sizeof(u64); | |
1321 | ||
1322 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1323 | size += sizeof(u64); | |
1324 | ||
1325 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1326 | entry += sizeof(u64); | |
1327 | ||
1328 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1329 | nr += nr_siblings; |
c320c7b7 ACM |
1330 | size += sizeof(u64); |
1331 | } | |
1332 | ||
1333 | size += entry * nr; | |
1334 | event->read_size = size; | |
1335 | } | |
1336 | ||
a723968c | 1337 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1338 | { |
1339 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1340 | u16 size = 0; |
1341 | ||
c320c7b7 ACM |
1342 | if (sample_type & PERF_SAMPLE_IP) |
1343 | size += sizeof(data->ip); | |
1344 | ||
6844c09d ACM |
1345 | if (sample_type & PERF_SAMPLE_ADDR) |
1346 | size += sizeof(data->addr); | |
1347 | ||
1348 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1349 | size += sizeof(data->period); | |
1350 | ||
c3feedf2 AK |
1351 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1352 | size += sizeof(data->weight); | |
1353 | ||
6844c09d ACM |
1354 | if (sample_type & PERF_SAMPLE_READ) |
1355 | size += event->read_size; | |
1356 | ||
d6be9ad6 SE |
1357 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1358 | size += sizeof(data->data_src.val); | |
1359 | ||
fdfbbd07 AK |
1360 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1361 | size += sizeof(data->txn); | |
1362 | ||
6844c09d ACM |
1363 | event->header_size = size; |
1364 | } | |
1365 | ||
a723968c PZ |
1366 | /* |
1367 | * Called at perf_event creation and when events are attached/detached from a | |
1368 | * group. | |
1369 | */ | |
1370 | static void perf_event__header_size(struct perf_event *event) | |
1371 | { | |
1372 | __perf_event_read_size(event, | |
1373 | event->group_leader->nr_siblings); | |
1374 | __perf_event_header_size(event, event->attr.sample_type); | |
1375 | } | |
1376 | ||
6844c09d ACM |
1377 | static void perf_event__id_header_size(struct perf_event *event) |
1378 | { | |
1379 | struct perf_sample_data *data; | |
1380 | u64 sample_type = event->attr.sample_type; | |
1381 | u16 size = 0; | |
1382 | ||
c320c7b7 ACM |
1383 | if (sample_type & PERF_SAMPLE_TID) |
1384 | size += sizeof(data->tid_entry); | |
1385 | ||
1386 | if (sample_type & PERF_SAMPLE_TIME) | |
1387 | size += sizeof(data->time); | |
1388 | ||
ff3d527c AH |
1389 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1390 | size += sizeof(data->id); | |
1391 | ||
c320c7b7 ACM |
1392 | if (sample_type & PERF_SAMPLE_ID) |
1393 | size += sizeof(data->id); | |
1394 | ||
1395 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1396 | size += sizeof(data->stream_id); | |
1397 | ||
1398 | if (sample_type & PERF_SAMPLE_CPU) | |
1399 | size += sizeof(data->cpu_entry); | |
1400 | ||
6844c09d | 1401 | event->id_header_size = size; |
c320c7b7 ACM |
1402 | } |
1403 | ||
a723968c PZ |
1404 | static bool perf_event_validate_size(struct perf_event *event) |
1405 | { | |
1406 | /* | |
1407 | * The values computed here will be over-written when we actually | |
1408 | * attach the event. | |
1409 | */ | |
1410 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1411 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1412 | perf_event__id_header_size(event); | |
1413 | ||
1414 | /* | |
1415 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1416 | * Conservative limit to allow for callchains and other variable fields. | |
1417 | */ | |
1418 | if (event->read_size + event->header_size + | |
1419 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1420 | return false; | |
1421 | ||
1422 | return true; | |
1423 | } | |
1424 | ||
8a49542c PZ |
1425 | static void perf_group_attach(struct perf_event *event) |
1426 | { | |
c320c7b7 | 1427 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1428 | |
74c3337c PZ |
1429 | /* |
1430 | * We can have double attach due to group movement in perf_event_open. | |
1431 | */ | |
1432 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1433 | return; | |
1434 | ||
8a49542c PZ |
1435 | event->attach_state |= PERF_ATTACH_GROUP; |
1436 | ||
1437 | if (group_leader == event) | |
1438 | return; | |
1439 | ||
652884fe PZ |
1440 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1441 | ||
8a49542c PZ |
1442 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1443 | !is_software_event(event)) | |
1444 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1445 | ||
1446 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1447 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1448 | |
1449 | perf_event__header_size(group_leader); | |
1450 | ||
1451 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1452 | perf_event__header_size(pos); | |
8a49542c PZ |
1453 | } |
1454 | ||
a63eaf34 | 1455 | /* |
cdd6c482 | 1456 | * Remove a event from the lists for its context. |
fccc714b | 1457 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1458 | */ |
04289bb9 | 1459 | static void |
cdd6c482 | 1460 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1461 | { |
68cacd29 | 1462 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1463 | |
1464 | WARN_ON_ONCE(event->ctx != ctx); | |
1465 | lockdep_assert_held(&ctx->lock); | |
1466 | ||
8a49542c PZ |
1467 | /* |
1468 | * We can have double detach due to exit/hot-unplug + close. | |
1469 | */ | |
1470 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1471 | return; |
8a49542c PZ |
1472 | |
1473 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1474 | ||
68cacd29 | 1475 | if (is_cgroup_event(event)) { |
e5d1367f | 1476 | ctx->nr_cgroups--; |
70a01657 PZ |
1477 | /* |
1478 | * Because cgroup events are always per-cpu events, this will | |
1479 | * always be called from the right CPU. | |
1480 | */ | |
68cacd29 SE |
1481 | cpuctx = __get_cpu_context(ctx); |
1482 | /* | |
70a01657 PZ |
1483 | * If there are no more cgroup events then clear cgrp to avoid |
1484 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1485 | */ |
1486 | if (!ctx->nr_cgroups) | |
1487 | cpuctx->cgrp = NULL; | |
1488 | } | |
e5d1367f | 1489 | |
cdd6c482 IM |
1490 | ctx->nr_events--; |
1491 | if (event->attr.inherit_stat) | |
bfbd3381 | 1492 | ctx->nr_stat--; |
8bc20959 | 1493 | |
cdd6c482 | 1494 | list_del_rcu(&event->event_entry); |
04289bb9 | 1495 | |
8a49542c PZ |
1496 | if (event->group_leader == event) |
1497 | list_del_init(&event->group_entry); | |
5c148194 | 1498 | |
96c21a46 | 1499 | update_group_times(event); |
b2e74a26 SE |
1500 | |
1501 | /* | |
1502 | * If event was in error state, then keep it | |
1503 | * that way, otherwise bogus counts will be | |
1504 | * returned on read(). The only way to get out | |
1505 | * of error state is by explicit re-enabling | |
1506 | * of the event | |
1507 | */ | |
1508 | if (event->state > PERF_EVENT_STATE_OFF) | |
1509 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1510 | |
1511 | ctx->generation++; | |
050735b0 PZ |
1512 | } |
1513 | ||
8a49542c | 1514 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1515 | { |
1516 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1517 | struct list_head *list = NULL; |
1518 | ||
1519 | /* | |
1520 | * We can have double detach due to exit/hot-unplug + close. | |
1521 | */ | |
1522 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1523 | return; | |
1524 | ||
1525 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1526 | ||
1527 | /* | |
1528 | * If this is a sibling, remove it from its group. | |
1529 | */ | |
1530 | if (event->group_leader != event) { | |
1531 | list_del_init(&event->group_entry); | |
1532 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1533 | goto out; |
8a49542c PZ |
1534 | } |
1535 | ||
1536 | if (!list_empty(&event->group_entry)) | |
1537 | list = &event->group_entry; | |
2e2af50b | 1538 | |
04289bb9 | 1539 | /* |
cdd6c482 IM |
1540 | * If this was a group event with sibling events then |
1541 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1542 | * to whatever list we are on. |
04289bb9 | 1543 | */ |
cdd6c482 | 1544 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1545 | if (list) |
1546 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1547 | sibling->group_leader = sibling; |
d6f962b5 FW |
1548 | |
1549 | /* Inherit group flags from the previous leader */ | |
1550 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1551 | |
1552 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1553 | } |
c320c7b7 ACM |
1554 | |
1555 | out: | |
1556 | perf_event__header_size(event->group_leader); | |
1557 | ||
1558 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1559 | perf_event__header_size(tmp); | |
04289bb9 IM |
1560 | } |
1561 | ||
fadfe7be JO |
1562 | /* |
1563 | * User event without the task. | |
1564 | */ | |
1565 | static bool is_orphaned_event(struct perf_event *event) | |
1566 | { | |
1567 | return event && !is_kernel_event(event) && !event->owner; | |
1568 | } | |
1569 | ||
1570 | /* | |
1571 | * Event has a parent but parent's task finished and it's | |
1572 | * alive only because of children holding refference. | |
1573 | */ | |
1574 | static bool is_orphaned_child(struct perf_event *event) | |
1575 | { | |
1576 | return is_orphaned_event(event->parent); | |
1577 | } | |
1578 | ||
1579 | static void orphans_remove_work(struct work_struct *work); | |
1580 | ||
1581 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1582 | { | |
1583 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1584 | return; | |
1585 | ||
1586 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1587 | get_ctx(ctx); | |
1588 | ctx->orphans_remove_sched = true; | |
1589 | } | |
1590 | } | |
1591 | ||
1592 | static int __init perf_workqueue_init(void) | |
1593 | { | |
1594 | perf_wq = create_singlethread_workqueue("perf"); | |
1595 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1596 | return perf_wq ? 0 : -1; | |
1597 | } | |
1598 | ||
1599 | core_initcall(perf_workqueue_init); | |
1600 | ||
66eb579e MR |
1601 | static inline int pmu_filter_match(struct perf_event *event) |
1602 | { | |
1603 | struct pmu *pmu = event->pmu; | |
1604 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1605 | } | |
1606 | ||
fa66f07a SE |
1607 | static inline int |
1608 | event_filter_match(struct perf_event *event) | |
1609 | { | |
e5d1367f | 1610 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1611 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1612 | } |
1613 | ||
9ffcfa6f SE |
1614 | static void |
1615 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1616 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1617 | struct perf_event_context *ctx) |
3b6f9e5c | 1618 | { |
4158755d | 1619 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1620 | u64 delta; |
652884fe PZ |
1621 | |
1622 | WARN_ON_ONCE(event->ctx != ctx); | |
1623 | lockdep_assert_held(&ctx->lock); | |
1624 | ||
fa66f07a SE |
1625 | /* |
1626 | * An event which could not be activated because of | |
1627 | * filter mismatch still needs to have its timings | |
1628 | * maintained, otherwise bogus information is return | |
1629 | * via read() for time_enabled, time_running: | |
1630 | */ | |
1631 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1632 | && !event_filter_match(event)) { | |
e5d1367f | 1633 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1634 | event->tstamp_running += delta; |
4158755d | 1635 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1636 | } |
1637 | ||
cdd6c482 | 1638 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1639 | return; |
3b6f9e5c | 1640 | |
44377277 AS |
1641 | perf_pmu_disable(event->pmu); |
1642 | ||
cdd6c482 IM |
1643 | event->state = PERF_EVENT_STATE_INACTIVE; |
1644 | if (event->pending_disable) { | |
1645 | event->pending_disable = 0; | |
1646 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1647 | } |
4158755d | 1648 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1649 | event->pmu->del(event, 0); |
cdd6c482 | 1650 | event->oncpu = -1; |
3b6f9e5c | 1651 | |
cdd6c482 | 1652 | if (!is_software_event(event)) |
3b6f9e5c | 1653 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1654 | if (!--ctx->nr_active) |
1655 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1656 | if (event->attr.freq && event->attr.sample_freq) |
1657 | ctx->nr_freq--; | |
cdd6c482 | 1658 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1659 | cpuctx->exclusive = 0; |
44377277 | 1660 | |
fadfe7be JO |
1661 | if (is_orphaned_child(event)) |
1662 | schedule_orphans_remove(ctx); | |
1663 | ||
44377277 | 1664 | perf_pmu_enable(event->pmu); |
3b6f9e5c PM |
1665 | } |
1666 | ||
d859e29f | 1667 | static void |
cdd6c482 | 1668 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1669 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1670 | struct perf_event_context *ctx) |
d859e29f | 1671 | { |
cdd6c482 | 1672 | struct perf_event *event; |
fa66f07a | 1673 | int state = group_event->state; |
d859e29f | 1674 | |
cdd6c482 | 1675 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1676 | |
1677 | /* | |
1678 | * Schedule out siblings (if any): | |
1679 | */ | |
cdd6c482 IM |
1680 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1681 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1682 | |
fa66f07a | 1683 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1684 | cpuctx->exclusive = 0; |
1685 | } | |
1686 | ||
46ce0fe9 PZ |
1687 | struct remove_event { |
1688 | struct perf_event *event; | |
1689 | bool detach_group; | |
1690 | }; | |
1691 | ||
0017960f PZ |
1692 | static void ___perf_remove_from_context(void *info) |
1693 | { | |
1694 | struct remove_event *re = info; | |
1695 | struct perf_event *event = re->event; | |
1696 | struct perf_event_context *ctx = event->ctx; | |
1697 | ||
1698 | if (re->detach_group) | |
1699 | perf_group_detach(event); | |
1700 | list_del_event(event, ctx); | |
1701 | } | |
1702 | ||
0793a61d | 1703 | /* |
cdd6c482 | 1704 | * Cross CPU call to remove a performance event |
0793a61d | 1705 | * |
cdd6c482 | 1706 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1707 | * remove it from the context list. |
1708 | */ | |
fe4b04fa | 1709 | static int __perf_remove_from_context(void *info) |
0793a61d | 1710 | { |
46ce0fe9 PZ |
1711 | struct remove_event *re = info; |
1712 | struct perf_event *event = re->event; | |
cdd6c482 | 1713 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1714 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
0793a61d | 1715 | |
e625cce1 | 1716 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 1717 | event_sched_out(event, cpuctx, ctx); |
46ce0fe9 PZ |
1718 | if (re->detach_group) |
1719 | perf_group_detach(event); | |
cdd6c482 | 1720 | list_del_event(event, ctx); |
39a43640 PZ |
1721 | |
1722 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1723 | ctx->is_active = 0; |
39a43640 PZ |
1724 | if (ctx->task) { |
1725 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1726 | cpuctx->task_ctx = NULL; | |
1727 | } | |
64ce3126 | 1728 | } |
e625cce1 | 1729 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1730 | |
1731 | return 0; | |
0793a61d TG |
1732 | } |
1733 | ||
0793a61d | 1734 | /* |
cdd6c482 | 1735 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1736 | * |
cdd6c482 | 1737 | * CPU events are removed with a smp call. For task events we only |
0793a61d | 1738 | * call when the task is on a CPU. |
c93f7669 | 1739 | * |
cdd6c482 IM |
1740 | * If event->ctx is a cloned context, callers must make sure that |
1741 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1742 | * remains valid. This is OK when called from perf_release since |
1743 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1744 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1745 | * context has been detached from its task. |
0793a61d | 1746 | */ |
46ce0fe9 | 1747 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1748 | { |
cdd6c482 | 1749 | struct perf_event_context *ctx = event->ctx; |
46ce0fe9 PZ |
1750 | struct remove_event re = { |
1751 | .event = event, | |
1752 | .detach_group = detach_group, | |
1753 | }; | |
0793a61d | 1754 | |
fe4b04fa PZ |
1755 | lockdep_assert_held(&ctx->mutex); |
1756 | ||
0017960f PZ |
1757 | event_function_call(event, __perf_remove_from_context, |
1758 | ___perf_remove_from_context, &re); | |
0793a61d TG |
1759 | } |
1760 | ||
d859e29f | 1761 | /* |
cdd6c482 | 1762 | * Cross CPU call to disable a performance event |
d859e29f | 1763 | */ |
500ad2d8 | 1764 | int __perf_event_disable(void *info) |
d859e29f | 1765 | { |
cdd6c482 | 1766 | struct perf_event *event = info; |
cdd6c482 | 1767 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1768 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f PM |
1769 | |
1770 | /* | |
cdd6c482 IM |
1771 | * If this is a per-task event, need to check whether this |
1772 | * event's task is the current task on this cpu. | |
fe4b04fa PZ |
1773 | * |
1774 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1775 | * flipping contexts around. | |
d859e29f | 1776 | */ |
665c2142 | 1777 | if (ctx->task && cpuctx->task_ctx != ctx) |
fe4b04fa | 1778 | return -EINVAL; |
d859e29f | 1779 | |
e625cce1 | 1780 | raw_spin_lock(&ctx->lock); |
d859e29f PM |
1781 | |
1782 | /* | |
cdd6c482 | 1783 | * If the event is on, turn it off. |
d859e29f PM |
1784 | * If it is in error state, leave it in error state. |
1785 | */ | |
cdd6c482 | 1786 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
4af4998b | 1787 | update_context_time(ctx); |
e5d1367f | 1788 | update_cgrp_time_from_event(event); |
cdd6c482 IM |
1789 | update_group_times(event); |
1790 | if (event == event->group_leader) | |
1791 | group_sched_out(event, cpuctx, ctx); | |
d859e29f | 1792 | else |
cdd6c482 IM |
1793 | event_sched_out(event, cpuctx, ctx); |
1794 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f PM |
1795 | } |
1796 | ||
e625cce1 | 1797 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1798 | |
1799 | return 0; | |
d859e29f PM |
1800 | } |
1801 | ||
7b648018 PZ |
1802 | void ___perf_event_disable(void *info) |
1803 | { | |
1804 | struct perf_event *event = info; | |
1805 | ||
1806 | /* | |
1807 | * Since we have the lock this context can't be scheduled | |
1808 | * in, so we can change the state safely. | |
1809 | */ | |
1810 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
1811 | update_group_times(event); | |
1812 | event->state = PERF_EVENT_STATE_OFF; | |
1813 | } | |
1814 | } | |
1815 | ||
d859e29f | 1816 | /* |
cdd6c482 | 1817 | * Disable a event. |
c93f7669 | 1818 | * |
cdd6c482 IM |
1819 | * If event->ctx is a cloned context, callers must make sure that |
1820 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1821 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1822 | * perf_event_for_each_child or perf_event_for_each because they |
1823 | * hold the top-level event's child_mutex, so any descendant that | |
1824 | * goes to exit will block in sync_child_event. | |
1825 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1826 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1827 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1828 | */ |
f63a8daa | 1829 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1830 | { |
cdd6c482 | 1831 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1832 | |
e625cce1 | 1833 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1834 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1835 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1836 | return; |
53cfbf59 | 1837 | } |
e625cce1 | 1838 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 PZ |
1839 | |
1840 | event_function_call(event, __perf_event_disable, | |
1841 | ___perf_event_disable, event); | |
d859e29f | 1842 | } |
f63a8daa PZ |
1843 | |
1844 | /* | |
1845 | * Strictly speaking kernel users cannot create groups and therefore this | |
1846 | * interface does not need the perf_event_ctx_lock() magic. | |
1847 | */ | |
1848 | void perf_event_disable(struct perf_event *event) | |
1849 | { | |
1850 | struct perf_event_context *ctx; | |
1851 | ||
1852 | ctx = perf_event_ctx_lock(event); | |
1853 | _perf_event_disable(event); | |
1854 | perf_event_ctx_unlock(event, ctx); | |
1855 | } | |
dcfce4a0 | 1856 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1857 | |
e5d1367f SE |
1858 | static void perf_set_shadow_time(struct perf_event *event, |
1859 | struct perf_event_context *ctx, | |
1860 | u64 tstamp) | |
1861 | { | |
1862 | /* | |
1863 | * use the correct time source for the time snapshot | |
1864 | * | |
1865 | * We could get by without this by leveraging the | |
1866 | * fact that to get to this function, the caller | |
1867 | * has most likely already called update_context_time() | |
1868 | * and update_cgrp_time_xx() and thus both timestamp | |
1869 | * are identical (or very close). Given that tstamp is, | |
1870 | * already adjusted for cgroup, we could say that: | |
1871 | * tstamp - ctx->timestamp | |
1872 | * is equivalent to | |
1873 | * tstamp - cgrp->timestamp. | |
1874 | * | |
1875 | * Then, in perf_output_read(), the calculation would | |
1876 | * work with no changes because: | |
1877 | * - event is guaranteed scheduled in | |
1878 | * - no scheduled out in between | |
1879 | * - thus the timestamp would be the same | |
1880 | * | |
1881 | * But this is a bit hairy. | |
1882 | * | |
1883 | * So instead, we have an explicit cgroup call to remain | |
1884 | * within the time time source all along. We believe it | |
1885 | * is cleaner and simpler to understand. | |
1886 | */ | |
1887 | if (is_cgroup_event(event)) | |
1888 | perf_cgroup_set_shadow_time(event, tstamp); | |
1889 | else | |
1890 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1891 | } | |
1892 | ||
4fe757dd PZ |
1893 | #define MAX_INTERRUPTS (~0ULL) |
1894 | ||
1895 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1896 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1897 | |
235c7fc7 | 1898 | static int |
9ffcfa6f | 1899 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1900 | struct perf_cpu_context *cpuctx, |
6e37738a | 1901 | struct perf_event_context *ctx) |
235c7fc7 | 1902 | { |
4158755d | 1903 | u64 tstamp = perf_event_time(event); |
44377277 | 1904 | int ret = 0; |
4158755d | 1905 | |
63342411 PZ |
1906 | lockdep_assert_held(&ctx->lock); |
1907 | ||
cdd6c482 | 1908 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1909 | return 0; |
1910 | ||
cdd6c482 | 1911 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1912 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1913 | |
1914 | /* | |
1915 | * Unthrottle events, since we scheduled we might have missed several | |
1916 | * ticks already, also for a heavily scheduling task there is little | |
1917 | * guarantee it'll get a tick in a timely manner. | |
1918 | */ | |
1919 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1920 | perf_log_throttle(event, 1); | |
1921 | event->hw.interrupts = 0; | |
1922 | } | |
1923 | ||
235c7fc7 IM |
1924 | /* |
1925 | * The new state must be visible before we turn it on in the hardware: | |
1926 | */ | |
1927 | smp_wmb(); | |
1928 | ||
44377277 AS |
1929 | perf_pmu_disable(event->pmu); |
1930 | ||
72f669c0 SL |
1931 | perf_set_shadow_time(event, ctx, tstamp); |
1932 | ||
ec0d7729 AS |
1933 | perf_log_itrace_start(event); |
1934 | ||
a4eaf7f1 | 1935 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1936 | event->state = PERF_EVENT_STATE_INACTIVE; |
1937 | event->oncpu = -1; | |
44377277 AS |
1938 | ret = -EAGAIN; |
1939 | goto out; | |
235c7fc7 IM |
1940 | } |
1941 | ||
00a2916f PZ |
1942 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1943 | ||
cdd6c482 | 1944 | if (!is_software_event(event)) |
3b6f9e5c | 1945 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1946 | if (!ctx->nr_active++) |
1947 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1948 | if (event->attr.freq && event->attr.sample_freq) |
1949 | ctx->nr_freq++; | |
235c7fc7 | 1950 | |
cdd6c482 | 1951 | if (event->attr.exclusive) |
3b6f9e5c PM |
1952 | cpuctx->exclusive = 1; |
1953 | ||
fadfe7be JO |
1954 | if (is_orphaned_child(event)) |
1955 | schedule_orphans_remove(ctx); | |
1956 | ||
44377277 AS |
1957 | out: |
1958 | perf_pmu_enable(event->pmu); | |
1959 | ||
1960 | return ret; | |
235c7fc7 IM |
1961 | } |
1962 | ||
6751b71e | 1963 | static int |
cdd6c482 | 1964 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1965 | struct perf_cpu_context *cpuctx, |
6e37738a | 1966 | struct perf_event_context *ctx) |
6751b71e | 1967 | { |
6bde9b6c | 1968 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1969 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1970 | u64 now = ctx->time; |
1971 | bool simulate = false; | |
6751b71e | 1972 | |
cdd6c482 | 1973 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1974 | return 0; |
1975 | ||
fbbe0701 | 1976 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1977 | |
9ffcfa6f | 1978 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1979 | pmu->cancel_txn(pmu); |
272325c4 | 1980 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1981 | return -EAGAIN; |
90151c35 | 1982 | } |
6751b71e PM |
1983 | |
1984 | /* | |
1985 | * Schedule in siblings as one group (if any): | |
1986 | */ | |
cdd6c482 | 1987 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1988 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1989 | partial_group = event; |
6751b71e PM |
1990 | goto group_error; |
1991 | } | |
1992 | } | |
1993 | ||
9ffcfa6f | 1994 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1995 | return 0; |
9ffcfa6f | 1996 | |
6751b71e PM |
1997 | group_error: |
1998 | /* | |
1999 | * Groups can be scheduled in as one unit only, so undo any | |
2000 | * partial group before returning: | |
d7842da4 SE |
2001 | * The events up to the failed event are scheduled out normally, |
2002 | * tstamp_stopped will be updated. | |
2003 | * | |
2004 | * The failed events and the remaining siblings need to have | |
2005 | * their timings updated as if they had gone thru event_sched_in() | |
2006 | * and event_sched_out(). This is required to get consistent timings | |
2007 | * across the group. This also takes care of the case where the group | |
2008 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2009 | * the time the event was actually stopped, such that time delta | |
2010 | * calculation in update_event_times() is correct. | |
6751b71e | 2011 | */ |
cdd6c482 IM |
2012 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2013 | if (event == partial_group) | |
d7842da4 SE |
2014 | simulate = true; |
2015 | ||
2016 | if (simulate) { | |
2017 | event->tstamp_running += now - event->tstamp_stopped; | |
2018 | event->tstamp_stopped = now; | |
2019 | } else { | |
2020 | event_sched_out(event, cpuctx, ctx); | |
2021 | } | |
6751b71e | 2022 | } |
9ffcfa6f | 2023 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2024 | |
ad5133b7 | 2025 | pmu->cancel_txn(pmu); |
90151c35 | 2026 | |
272325c4 | 2027 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2028 | |
6751b71e PM |
2029 | return -EAGAIN; |
2030 | } | |
2031 | ||
3b6f9e5c | 2032 | /* |
cdd6c482 | 2033 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2034 | */ |
cdd6c482 | 2035 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2036 | struct perf_cpu_context *cpuctx, |
2037 | int can_add_hw) | |
2038 | { | |
2039 | /* | |
cdd6c482 | 2040 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2041 | */ |
d6f962b5 | 2042 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2043 | return 1; |
2044 | /* | |
2045 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2046 | * events can go on. |
3b6f9e5c PM |
2047 | */ |
2048 | if (cpuctx->exclusive) | |
2049 | return 0; | |
2050 | /* | |
2051 | * If this group is exclusive and there are already | |
cdd6c482 | 2052 | * events on the CPU, it can't go on. |
3b6f9e5c | 2053 | */ |
cdd6c482 | 2054 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2055 | return 0; |
2056 | /* | |
2057 | * Otherwise, try to add it if all previous groups were able | |
2058 | * to go on. | |
2059 | */ | |
2060 | return can_add_hw; | |
2061 | } | |
2062 | ||
cdd6c482 IM |
2063 | static void add_event_to_ctx(struct perf_event *event, |
2064 | struct perf_event_context *ctx) | |
53cfbf59 | 2065 | { |
4158755d SE |
2066 | u64 tstamp = perf_event_time(event); |
2067 | ||
cdd6c482 | 2068 | list_add_event(event, ctx); |
8a49542c | 2069 | perf_group_attach(event); |
4158755d SE |
2070 | event->tstamp_enabled = tstamp; |
2071 | event->tstamp_running = tstamp; | |
2072 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2073 | } |
2074 | ||
3e349507 PZ |
2075 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2076 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2077 | static void |
2078 | ctx_sched_in(struct perf_event_context *ctx, | |
2079 | struct perf_cpu_context *cpuctx, | |
2080 | enum event_type_t event_type, | |
2081 | struct task_struct *task); | |
fe4b04fa | 2082 | |
dce5855b PZ |
2083 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2084 | struct perf_event_context *ctx, | |
2085 | struct task_struct *task) | |
2086 | { | |
2087 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2088 | if (ctx) | |
2089 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2090 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2091 | if (ctx) | |
2092 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2093 | } | |
2094 | ||
3e349507 PZ |
2095 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2096 | struct perf_event_context *task_ctx) | |
2097 | { | |
2098 | perf_pmu_disable(cpuctx->ctx.pmu); | |
2099 | if (task_ctx) | |
2100 | task_ctx_sched_out(cpuctx, task_ctx); | |
2101 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2102 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2103 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2104 | } | |
2105 | ||
0793a61d | 2106 | /* |
cdd6c482 | 2107 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2108 | * |
2109 | * Must be called with ctx->mutex held | |
0793a61d | 2110 | */ |
fe4b04fa | 2111 | static int __perf_install_in_context(void *info) |
0793a61d | 2112 | { |
39a43640 | 2113 | struct perf_event_context *ctx = info; |
108b02cf | 2114 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2115 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
2c29ef0f | 2116 | |
39a43640 PZ |
2117 | if (ctx->task) { |
2118 | /* | |
2119 | * If we hit the 'wrong' task, we've since scheduled and | |
2120 | * everything should be sorted, nothing to do! | |
2121 | */ | |
2122 | if (ctx->task != current) | |
2123 | return 0; | |
b58f6b0d | 2124 | |
39a43640 PZ |
2125 | /* |
2126 | * If task_ctx is set, it had better be to us. | |
2127 | */ | |
2128 | WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx); | |
b58f6b0d PZ |
2129 | task_ctx = ctx; |
2130 | } | |
2131 | ||
39a43640 PZ |
2132 | perf_ctx_lock(cpuctx, task_ctx); |
2133 | ctx_resched(cpuctx, task_ctx); | |
2c29ef0f | 2134 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2135 | |
2136 | return 0; | |
0793a61d TG |
2137 | } |
2138 | ||
2139 | /* | |
cdd6c482 | 2140 | * Attach a performance event to a context |
0793a61d TG |
2141 | */ |
2142 | static void | |
cdd6c482 IM |
2143 | perf_install_in_context(struct perf_event_context *ctx, |
2144 | struct perf_event *event, | |
0793a61d TG |
2145 | int cpu) |
2146 | { | |
39a43640 PZ |
2147 | struct task_struct *task = NULL; |
2148 | ||
fe4b04fa PZ |
2149 | lockdep_assert_held(&ctx->mutex); |
2150 | ||
c3f00c70 | 2151 | event->ctx = ctx; |
0cda4c02 YZ |
2152 | if (event->cpu != -1) |
2153 | event->cpu = cpu; | |
c3f00c70 | 2154 | |
39a43640 PZ |
2155 | /* |
2156 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2157 | * to be set in case this is the nr_events 0 -> 1 transition. | |
2158 | * | |
2159 | * So what we do is we add the event to the list here, which will allow | |
2160 | * a future context switch to DTRT and then send a racy IPI. If the IPI | |
2161 | * fails to hit the right task, this means a context switch must have | |
2162 | * happened and that will have taken care of business. | |
2163 | */ | |
2164 | raw_spin_lock_irq(&ctx->lock); | |
2165 | update_context_time(ctx); | |
2166 | /* | |
2167 | * Update cgrp time only if current cgrp matches event->cgrp. | |
2168 | * Must be done before calling add_event_to_ctx(). | |
2169 | */ | |
2170 | update_cgrp_time_from_event(event); | |
2171 | add_event_to_ctx(event, ctx); | |
2172 | task = ctx->task; | |
2173 | raw_spin_unlock_irq(&ctx->lock); | |
2174 | ||
2175 | if (task) | |
2176 | task_function_call(task, __perf_install_in_context, ctx); | |
2177 | else | |
2178 | cpu_function_call(cpu, __perf_install_in_context, ctx); | |
0793a61d TG |
2179 | } |
2180 | ||
fa289bec | 2181 | /* |
cdd6c482 | 2182 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2183 | * Enabling the leader of a group effectively enables all |
2184 | * the group members that aren't explicitly disabled, so we | |
2185 | * have to update their ->tstamp_enabled also. | |
2186 | * Note: this works for group members as well as group leaders | |
2187 | * since the non-leader members' sibling_lists will be empty. | |
2188 | */ | |
1d9b482e | 2189 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2190 | { |
cdd6c482 | 2191 | struct perf_event *sub; |
4158755d | 2192 | u64 tstamp = perf_event_time(event); |
fa289bec | 2193 | |
cdd6c482 | 2194 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2195 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2196 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2197 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2198 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2199 | } |
fa289bec PM |
2200 | } |
2201 | ||
d859e29f | 2202 | /* |
cdd6c482 | 2203 | * Cross CPU call to enable a performance event |
d859e29f | 2204 | */ |
fe4b04fa | 2205 | static int __perf_event_enable(void *info) |
04289bb9 | 2206 | { |
cdd6c482 | 2207 | struct perf_event *event = info; |
cdd6c482 IM |
2208 | struct perf_event_context *ctx = event->ctx; |
2209 | struct perf_event *leader = event->group_leader; | |
108b02cf | 2210 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
aee7dbc4 | 2211 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
04289bb9 | 2212 | |
06f41796 JO |
2213 | /* |
2214 | * There's a time window between 'ctx->is_active' check | |
2215 | * in perf_event_enable function and this place having: | |
2216 | * - IRQs on | |
2217 | * - ctx->lock unlocked | |
2218 | * | |
2219 | * where the task could be killed and 'ctx' deactivated | |
2220 | * by perf_event_exit_task. | |
2221 | */ | |
2222 | if (!ctx->is_active) | |
fe4b04fa | 2223 | return -EINVAL; |
3cbed429 | 2224 | |
aee7dbc4 PZ |
2225 | perf_ctx_lock(cpuctx, task_ctx); |
2226 | WARN_ON_ONCE(&cpuctx->ctx != ctx && task_ctx != ctx); | |
4af4998b | 2227 | update_context_time(ctx); |
d859e29f | 2228 | |
cdd6c482 | 2229 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f | 2230 | goto unlock; |
e5d1367f SE |
2231 | |
2232 | /* | |
2233 | * set current task's cgroup time reference point | |
2234 | */ | |
3f7cce3c | 2235 | perf_cgroup_set_timestamp(current, ctx); |
e5d1367f | 2236 | |
1d9b482e | 2237 | __perf_event_mark_enabled(event); |
04289bb9 | 2238 | |
e5d1367f SE |
2239 | if (!event_filter_match(event)) { |
2240 | if (is_cgroup_event(event)) | |
2241 | perf_cgroup_defer_enabled(event); | |
f4c4176f | 2242 | goto unlock; |
e5d1367f | 2243 | } |
f4c4176f | 2244 | |
04289bb9 | 2245 | /* |
cdd6c482 | 2246 | * If the event is in a group and isn't the group leader, |
d859e29f | 2247 | * then don't put it on unless the group is on. |
04289bb9 | 2248 | */ |
cdd6c482 | 2249 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
d859e29f | 2250 | goto unlock; |
3b6f9e5c | 2251 | |
aee7dbc4 | 2252 | ctx_resched(cpuctx, task_ctx); |
d859e29f | 2253 | |
9ed6060d | 2254 | unlock: |
aee7dbc4 | 2255 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2256 | |
2257 | return 0; | |
d859e29f PM |
2258 | } |
2259 | ||
7b648018 PZ |
2260 | void ___perf_event_enable(void *info) |
2261 | { | |
2262 | __perf_event_mark_enabled((struct perf_event *)info); | |
2263 | } | |
2264 | ||
d859e29f | 2265 | /* |
cdd6c482 | 2266 | * Enable a event. |
c93f7669 | 2267 | * |
cdd6c482 IM |
2268 | * If event->ctx is a cloned context, callers must make sure that |
2269 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2270 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2271 | * perf_event_for_each_child or perf_event_for_each as described |
2272 | * for perf_event_disable. | |
d859e29f | 2273 | */ |
f63a8daa | 2274 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2275 | { |
cdd6c482 | 2276 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2277 | |
7b648018 PZ |
2278 | raw_spin_lock_irq(&ctx->lock); |
2279 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
2280 | raw_spin_unlock_irq(&ctx->lock); | |
d859e29f PM |
2281 | return; |
2282 | } | |
2283 | ||
d859e29f | 2284 | /* |
cdd6c482 | 2285 | * If the event is in error state, clear that first. |
7b648018 PZ |
2286 | * |
2287 | * That way, if we see the event in error state below, we know that it | |
2288 | * has gone back into error state, as distinct from the task having | |
2289 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2290 | */ |
cdd6c482 IM |
2291 | if (event->state == PERF_EVENT_STATE_ERROR) |
2292 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2293 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2294 | |
7b648018 PZ |
2295 | event_function_call(event, __perf_event_enable, |
2296 | ___perf_event_enable, event); | |
d859e29f | 2297 | } |
f63a8daa PZ |
2298 | |
2299 | /* | |
2300 | * See perf_event_disable(); | |
2301 | */ | |
2302 | void perf_event_enable(struct perf_event *event) | |
2303 | { | |
2304 | struct perf_event_context *ctx; | |
2305 | ||
2306 | ctx = perf_event_ctx_lock(event); | |
2307 | _perf_event_enable(event); | |
2308 | perf_event_ctx_unlock(event, ctx); | |
2309 | } | |
dcfce4a0 | 2310 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2311 | |
f63a8daa | 2312 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2313 | { |
2023b359 | 2314 | /* |
cdd6c482 | 2315 | * not supported on inherited events |
2023b359 | 2316 | */ |
2e939d1d | 2317 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2318 | return -EINVAL; |
2319 | ||
cdd6c482 | 2320 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2321 | _perf_event_enable(event); |
2023b359 PZ |
2322 | |
2323 | return 0; | |
79f14641 | 2324 | } |
f63a8daa PZ |
2325 | |
2326 | /* | |
2327 | * See perf_event_disable() | |
2328 | */ | |
2329 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2330 | { | |
2331 | struct perf_event_context *ctx; | |
2332 | int ret; | |
2333 | ||
2334 | ctx = perf_event_ctx_lock(event); | |
2335 | ret = _perf_event_refresh(event, refresh); | |
2336 | perf_event_ctx_unlock(event, ctx); | |
2337 | ||
2338 | return ret; | |
2339 | } | |
26ca5c11 | 2340 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2341 | |
5b0311e1 FW |
2342 | static void ctx_sched_out(struct perf_event_context *ctx, |
2343 | struct perf_cpu_context *cpuctx, | |
2344 | enum event_type_t event_type) | |
235c7fc7 | 2345 | { |
db24d33e | 2346 | int is_active = ctx->is_active; |
c994d613 PZ |
2347 | struct perf_event *event; |
2348 | ||
2349 | lockdep_assert_held(&ctx->lock); | |
235c7fc7 | 2350 | |
39a43640 PZ |
2351 | if (likely(!ctx->nr_events)) { |
2352 | /* | |
2353 | * See __perf_remove_from_context(). | |
2354 | */ | |
2355 | WARN_ON_ONCE(ctx->is_active); | |
2356 | if (ctx->task) | |
2357 | WARN_ON_ONCE(cpuctx->task_ctx); | |
2358 | return; | |
2359 | } | |
2360 | ||
db24d33e | 2361 | ctx->is_active &= ~event_type; |
63e30d3e PZ |
2362 | if (ctx->task) { |
2363 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2364 | if (!ctx->is_active) | |
2365 | cpuctx->task_ctx = NULL; | |
2366 | } | |
2367 | ||
4af4998b | 2368 | update_context_time(ctx); |
e5d1367f | 2369 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2370 | if (!ctx->nr_active) |
facc4307 | 2371 | return; |
5b0311e1 | 2372 | |
075e0b00 | 2373 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2374 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2375 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2376 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2377 | } |
889ff015 | 2378 | |
db24d33e | 2379 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2380 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2381 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2382 | } |
1b9a644f | 2383 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2384 | } |
2385 | ||
564c2b21 | 2386 | /* |
5a3126d4 PZ |
2387 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2388 | * cloned from the same version of the same context. | |
2389 | * | |
2390 | * Equivalence is measured using a generation number in the context that is | |
2391 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2392 | * and list_del_event(). | |
564c2b21 | 2393 | */ |
cdd6c482 IM |
2394 | static int context_equiv(struct perf_event_context *ctx1, |
2395 | struct perf_event_context *ctx2) | |
564c2b21 | 2396 | { |
211de6eb PZ |
2397 | lockdep_assert_held(&ctx1->lock); |
2398 | lockdep_assert_held(&ctx2->lock); | |
2399 | ||
5a3126d4 PZ |
2400 | /* Pinning disables the swap optimization */ |
2401 | if (ctx1->pin_count || ctx2->pin_count) | |
2402 | return 0; | |
2403 | ||
2404 | /* If ctx1 is the parent of ctx2 */ | |
2405 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2406 | return 1; | |
2407 | ||
2408 | /* If ctx2 is the parent of ctx1 */ | |
2409 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2410 | return 1; | |
2411 | ||
2412 | /* | |
2413 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2414 | * hierarchy, see perf_event_init_context(). | |
2415 | */ | |
2416 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2417 | ctx1->parent_gen == ctx2->parent_gen) | |
2418 | return 1; | |
2419 | ||
2420 | /* Unmatched */ | |
2421 | return 0; | |
564c2b21 PM |
2422 | } |
2423 | ||
cdd6c482 IM |
2424 | static void __perf_event_sync_stat(struct perf_event *event, |
2425 | struct perf_event *next_event) | |
bfbd3381 PZ |
2426 | { |
2427 | u64 value; | |
2428 | ||
cdd6c482 | 2429 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2430 | return; |
2431 | ||
2432 | /* | |
cdd6c482 | 2433 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2434 | * because we're in the middle of a context switch and have IRQs |
2435 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2436 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2437 | * don't need to use it. |
2438 | */ | |
cdd6c482 IM |
2439 | switch (event->state) { |
2440 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2441 | event->pmu->read(event); |
2442 | /* fall-through */ | |
bfbd3381 | 2443 | |
cdd6c482 IM |
2444 | case PERF_EVENT_STATE_INACTIVE: |
2445 | update_event_times(event); | |
bfbd3381 PZ |
2446 | break; |
2447 | ||
2448 | default: | |
2449 | break; | |
2450 | } | |
2451 | ||
2452 | /* | |
cdd6c482 | 2453 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2454 | * values when we flip the contexts. |
2455 | */ | |
e7850595 PZ |
2456 | value = local64_read(&next_event->count); |
2457 | value = local64_xchg(&event->count, value); | |
2458 | local64_set(&next_event->count, value); | |
bfbd3381 | 2459 | |
cdd6c482 IM |
2460 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2461 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2462 | |
bfbd3381 | 2463 | /* |
19d2e755 | 2464 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2465 | */ |
cdd6c482 IM |
2466 | perf_event_update_userpage(event); |
2467 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2468 | } |
2469 | ||
cdd6c482 IM |
2470 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2471 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2472 | { |
cdd6c482 | 2473 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2474 | |
2475 | if (!ctx->nr_stat) | |
2476 | return; | |
2477 | ||
02ffdbc8 PZ |
2478 | update_context_time(ctx); |
2479 | ||
cdd6c482 IM |
2480 | event = list_first_entry(&ctx->event_list, |
2481 | struct perf_event, event_entry); | |
bfbd3381 | 2482 | |
cdd6c482 IM |
2483 | next_event = list_first_entry(&next_ctx->event_list, |
2484 | struct perf_event, event_entry); | |
bfbd3381 | 2485 | |
cdd6c482 IM |
2486 | while (&event->event_entry != &ctx->event_list && |
2487 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2488 | |
cdd6c482 | 2489 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2490 | |
cdd6c482 IM |
2491 | event = list_next_entry(event, event_entry); |
2492 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2493 | } |
2494 | } | |
2495 | ||
fe4b04fa PZ |
2496 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2497 | struct task_struct *next) | |
0793a61d | 2498 | { |
8dc85d54 | 2499 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2500 | struct perf_event_context *next_ctx; |
5a3126d4 | 2501 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2502 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2503 | int do_switch = 1; |
0793a61d | 2504 | |
108b02cf PZ |
2505 | if (likely(!ctx)) |
2506 | return; | |
10989fb2 | 2507 | |
108b02cf PZ |
2508 | cpuctx = __get_cpu_context(ctx); |
2509 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2510 | return; |
2511 | ||
c93f7669 | 2512 | rcu_read_lock(); |
8dc85d54 | 2513 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2514 | if (!next_ctx) |
2515 | goto unlock; | |
2516 | ||
2517 | parent = rcu_dereference(ctx->parent_ctx); | |
2518 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2519 | ||
2520 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2521 | if (!parent && !next_parent) |
5a3126d4 PZ |
2522 | goto unlock; |
2523 | ||
2524 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2525 | /* |
2526 | * Looks like the two contexts are clones, so we might be | |
2527 | * able to optimize the context switch. We lock both | |
2528 | * contexts and check that they are clones under the | |
2529 | * lock (including re-checking that neither has been | |
2530 | * uncloned in the meantime). It doesn't matter which | |
2531 | * order we take the locks because no other cpu could | |
2532 | * be trying to lock both of these tasks. | |
2533 | */ | |
e625cce1 TG |
2534 | raw_spin_lock(&ctx->lock); |
2535 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2536 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2537 | /* |
2538 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2539 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2540 | */ |
8dc85d54 PZ |
2541 | task->perf_event_ctxp[ctxn] = next_ctx; |
2542 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2543 | ctx->task = next; |
2544 | next_ctx->task = task; | |
5a158c3c YZ |
2545 | |
2546 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2547 | ||
c93f7669 | 2548 | do_switch = 0; |
bfbd3381 | 2549 | |
cdd6c482 | 2550 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2551 | } |
e625cce1 TG |
2552 | raw_spin_unlock(&next_ctx->lock); |
2553 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2554 | } |
5a3126d4 | 2555 | unlock: |
c93f7669 | 2556 | rcu_read_unlock(); |
564c2b21 | 2557 | |
c93f7669 | 2558 | if (do_switch) { |
facc4307 | 2559 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2560 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2561 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2562 | } |
0793a61d TG |
2563 | } |
2564 | ||
ba532500 YZ |
2565 | void perf_sched_cb_dec(struct pmu *pmu) |
2566 | { | |
2567 | this_cpu_dec(perf_sched_cb_usages); | |
2568 | } | |
2569 | ||
2570 | void perf_sched_cb_inc(struct pmu *pmu) | |
2571 | { | |
2572 | this_cpu_inc(perf_sched_cb_usages); | |
2573 | } | |
2574 | ||
2575 | /* | |
2576 | * This function provides the context switch callback to the lower code | |
2577 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2578 | */ | |
2579 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2580 | struct task_struct *next, | |
2581 | bool sched_in) | |
2582 | { | |
2583 | struct perf_cpu_context *cpuctx; | |
2584 | struct pmu *pmu; | |
2585 | unsigned long flags; | |
2586 | ||
2587 | if (prev == next) | |
2588 | return; | |
2589 | ||
2590 | local_irq_save(flags); | |
2591 | ||
2592 | rcu_read_lock(); | |
2593 | ||
2594 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2595 | if (pmu->sched_task) { | |
2596 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2597 | ||
2598 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2599 | ||
2600 | perf_pmu_disable(pmu); | |
2601 | ||
2602 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2603 | ||
2604 | perf_pmu_enable(pmu); | |
2605 | ||
2606 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2607 | } | |
2608 | } | |
2609 | ||
2610 | rcu_read_unlock(); | |
2611 | ||
2612 | local_irq_restore(flags); | |
2613 | } | |
2614 | ||
45ac1403 AH |
2615 | static void perf_event_switch(struct task_struct *task, |
2616 | struct task_struct *next_prev, bool sched_in); | |
2617 | ||
8dc85d54 PZ |
2618 | #define for_each_task_context_nr(ctxn) \ |
2619 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2620 | ||
2621 | /* | |
2622 | * Called from scheduler to remove the events of the current task, | |
2623 | * with interrupts disabled. | |
2624 | * | |
2625 | * We stop each event and update the event value in event->count. | |
2626 | * | |
2627 | * This does not protect us against NMI, but disable() | |
2628 | * sets the disabled bit in the control field of event _before_ | |
2629 | * accessing the event control register. If a NMI hits, then it will | |
2630 | * not restart the event. | |
2631 | */ | |
ab0cce56 JO |
2632 | void __perf_event_task_sched_out(struct task_struct *task, |
2633 | struct task_struct *next) | |
8dc85d54 PZ |
2634 | { |
2635 | int ctxn; | |
2636 | ||
ba532500 YZ |
2637 | if (__this_cpu_read(perf_sched_cb_usages)) |
2638 | perf_pmu_sched_task(task, next, false); | |
2639 | ||
45ac1403 AH |
2640 | if (atomic_read(&nr_switch_events)) |
2641 | perf_event_switch(task, next, false); | |
2642 | ||
8dc85d54 PZ |
2643 | for_each_task_context_nr(ctxn) |
2644 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2645 | |
2646 | /* | |
2647 | * if cgroup events exist on this CPU, then we need | |
2648 | * to check if we have to switch out PMU state. | |
2649 | * cgroup event are system-wide mode only | |
2650 | */ | |
4a32fea9 | 2651 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2652 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2653 | } |
2654 | ||
3e349507 PZ |
2655 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2656 | struct perf_event_context *ctx) | |
a08b159f | 2657 | { |
a63eaf34 PM |
2658 | if (!cpuctx->task_ctx) |
2659 | return; | |
012b84da IM |
2660 | |
2661 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2662 | return; | |
2663 | ||
04dc2dbb | 2664 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2665 | } |
2666 | ||
5b0311e1 FW |
2667 | /* |
2668 | * Called with IRQs disabled | |
2669 | */ | |
2670 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2671 | enum event_type_t event_type) | |
2672 | { | |
2673 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2674 | } |
2675 | ||
235c7fc7 | 2676 | static void |
5b0311e1 | 2677 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2678 | struct perf_cpu_context *cpuctx) |
0793a61d | 2679 | { |
cdd6c482 | 2680 | struct perf_event *event; |
0793a61d | 2681 | |
889ff015 FW |
2682 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2683 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2684 | continue; |
5632ab12 | 2685 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2686 | continue; |
2687 | ||
e5d1367f SE |
2688 | /* may need to reset tstamp_enabled */ |
2689 | if (is_cgroup_event(event)) | |
2690 | perf_cgroup_mark_enabled(event, ctx); | |
2691 | ||
8c9ed8e1 | 2692 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2693 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2694 | |
2695 | /* | |
2696 | * If this pinned group hasn't been scheduled, | |
2697 | * put it in error state. | |
2698 | */ | |
cdd6c482 IM |
2699 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2700 | update_group_times(event); | |
2701 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2702 | } |
3b6f9e5c | 2703 | } |
5b0311e1 FW |
2704 | } |
2705 | ||
2706 | static void | |
2707 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2708 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2709 | { |
2710 | struct perf_event *event; | |
2711 | int can_add_hw = 1; | |
3b6f9e5c | 2712 | |
889ff015 FW |
2713 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2714 | /* Ignore events in OFF or ERROR state */ | |
2715 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2716 | continue; |
04289bb9 IM |
2717 | /* |
2718 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2719 | * of events: |
04289bb9 | 2720 | */ |
5632ab12 | 2721 | if (!event_filter_match(event)) |
0793a61d TG |
2722 | continue; |
2723 | ||
e5d1367f SE |
2724 | /* may need to reset tstamp_enabled */ |
2725 | if (is_cgroup_event(event)) | |
2726 | perf_cgroup_mark_enabled(event, ctx); | |
2727 | ||
9ed6060d | 2728 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2729 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2730 | can_add_hw = 0; |
9ed6060d | 2731 | } |
0793a61d | 2732 | } |
5b0311e1 FW |
2733 | } |
2734 | ||
2735 | static void | |
2736 | ctx_sched_in(struct perf_event_context *ctx, | |
2737 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2738 | enum event_type_t event_type, |
2739 | struct task_struct *task) | |
5b0311e1 | 2740 | { |
db24d33e | 2741 | int is_active = ctx->is_active; |
c994d613 PZ |
2742 | u64 now; |
2743 | ||
2744 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2745 | |
39a43640 PZ |
2746 | if (likely(!ctx->nr_events)) |
2747 | return; | |
2748 | ||
db24d33e | 2749 | ctx->is_active |= event_type; |
63e30d3e PZ |
2750 | if (ctx->task) { |
2751 | if (!is_active) | |
2752 | cpuctx->task_ctx = ctx; | |
2753 | else | |
2754 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2755 | } | |
2756 | ||
e5d1367f SE |
2757 | now = perf_clock(); |
2758 | ctx->timestamp = now; | |
3f7cce3c | 2759 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2760 | /* |
2761 | * First go through the list and put on any pinned groups | |
2762 | * in order to give them the best chance of going on. | |
2763 | */ | |
db24d33e | 2764 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2765 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2766 | |
2767 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2768 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2769 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2770 | } |
2771 | ||
329c0e01 | 2772 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2773 | enum event_type_t event_type, |
2774 | struct task_struct *task) | |
329c0e01 FW |
2775 | { |
2776 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2777 | ||
e5d1367f | 2778 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2779 | } |
2780 | ||
e5d1367f SE |
2781 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2782 | struct task_struct *task) | |
235c7fc7 | 2783 | { |
108b02cf | 2784 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2785 | |
108b02cf | 2786 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2787 | if (cpuctx->task_ctx == ctx) |
2788 | return; | |
2789 | ||
facc4307 | 2790 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2791 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2792 | /* |
2793 | * We want to keep the following priority order: | |
2794 | * cpu pinned (that don't need to move), task pinned, | |
2795 | * cpu flexible, task flexible. | |
2796 | */ | |
2797 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2798 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2799 | perf_pmu_enable(ctx->pmu); |
2800 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2801 | } |
2802 | ||
8dc85d54 PZ |
2803 | /* |
2804 | * Called from scheduler to add the events of the current task | |
2805 | * with interrupts disabled. | |
2806 | * | |
2807 | * We restore the event value and then enable it. | |
2808 | * | |
2809 | * This does not protect us against NMI, but enable() | |
2810 | * sets the enabled bit in the control field of event _before_ | |
2811 | * accessing the event control register. If a NMI hits, then it will | |
2812 | * keep the event running. | |
2813 | */ | |
ab0cce56 JO |
2814 | void __perf_event_task_sched_in(struct task_struct *prev, |
2815 | struct task_struct *task) | |
8dc85d54 PZ |
2816 | { |
2817 | struct perf_event_context *ctx; | |
2818 | int ctxn; | |
2819 | ||
7e41d177 PZ |
2820 | /* |
2821 | * If cgroup events exist on this CPU, then we need to check if we have | |
2822 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2823 | * | |
2824 | * Since cgroup events are CPU events, we must schedule these in before | |
2825 | * we schedule in the task events. | |
2826 | */ | |
2827 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2828 | perf_cgroup_sched_in(prev, task); | |
2829 | ||
8dc85d54 PZ |
2830 | for_each_task_context_nr(ctxn) { |
2831 | ctx = task->perf_event_ctxp[ctxn]; | |
2832 | if (likely(!ctx)) | |
2833 | continue; | |
2834 | ||
e5d1367f | 2835 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2836 | } |
d010b332 | 2837 | |
45ac1403 AH |
2838 | if (atomic_read(&nr_switch_events)) |
2839 | perf_event_switch(task, prev, true); | |
2840 | ||
ba532500 YZ |
2841 | if (__this_cpu_read(perf_sched_cb_usages)) |
2842 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2843 | } |
2844 | ||
abd50713 PZ |
2845 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2846 | { | |
2847 | u64 frequency = event->attr.sample_freq; | |
2848 | u64 sec = NSEC_PER_SEC; | |
2849 | u64 divisor, dividend; | |
2850 | ||
2851 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2852 | ||
2853 | count_fls = fls64(count); | |
2854 | nsec_fls = fls64(nsec); | |
2855 | frequency_fls = fls64(frequency); | |
2856 | sec_fls = 30; | |
2857 | ||
2858 | /* | |
2859 | * We got @count in @nsec, with a target of sample_freq HZ | |
2860 | * the target period becomes: | |
2861 | * | |
2862 | * @count * 10^9 | |
2863 | * period = ------------------- | |
2864 | * @nsec * sample_freq | |
2865 | * | |
2866 | */ | |
2867 | ||
2868 | /* | |
2869 | * Reduce accuracy by one bit such that @a and @b converge | |
2870 | * to a similar magnitude. | |
2871 | */ | |
fe4b04fa | 2872 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2873 | do { \ |
2874 | if (a##_fls > b##_fls) { \ | |
2875 | a >>= 1; \ | |
2876 | a##_fls--; \ | |
2877 | } else { \ | |
2878 | b >>= 1; \ | |
2879 | b##_fls--; \ | |
2880 | } \ | |
2881 | } while (0) | |
2882 | ||
2883 | /* | |
2884 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2885 | * the other, so that finally we can do a u64/u64 division. | |
2886 | */ | |
2887 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2888 | REDUCE_FLS(nsec, frequency); | |
2889 | REDUCE_FLS(sec, count); | |
2890 | } | |
2891 | ||
2892 | if (count_fls + sec_fls > 64) { | |
2893 | divisor = nsec * frequency; | |
2894 | ||
2895 | while (count_fls + sec_fls > 64) { | |
2896 | REDUCE_FLS(count, sec); | |
2897 | divisor >>= 1; | |
2898 | } | |
2899 | ||
2900 | dividend = count * sec; | |
2901 | } else { | |
2902 | dividend = count * sec; | |
2903 | ||
2904 | while (nsec_fls + frequency_fls > 64) { | |
2905 | REDUCE_FLS(nsec, frequency); | |
2906 | dividend >>= 1; | |
2907 | } | |
2908 | ||
2909 | divisor = nsec * frequency; | |
2910 | } | |
2911 | ||
f6ab91ad PZ |
2912 | if (!divisor) |
2913 | return dividend; | |
2914 | ||
abd50713 PZ |
2915 | return div64_u64(dividend, divisor); |
2916 | } | |
2917 | ||
e050e3f0 SE |
2918 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2919 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2920 | ||
f39d47ff | 2921 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2922 | { |
cdd6c482 | 2923 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2924 | s64 period, sample_period; |
bd2b5b12 PZ |
2925 | s64 delta; |
2926 | ||
abd50713 | 2927 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2928 | |
2929 | delta = (s64)(period - hwc->sample_period); | |
2930 | delta = (delta + 7) / 8; /* low pass filter */ | |
2931 | ||
2932 | sample_period = hwc->sample_period + delta; | |
2933 | ||
2934 | if (!sample_period) | |
2935 | sample_period = 1; | |
2936 | ||
bd2b5b12 | 2937 | hwc->sample_period = sample_period; |
abd50713 | 2938 | |
e7850595 | 2939 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2940 | if (disable) |
2941 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2942 | ||
e7850595 | 2943 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2944 | |
2945 | if (disable) | |
2946 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2947 | } |
bd2b5b12 PZ |
2948 | } |
2949 | ||
e050e3f0 SE |
2950 | /* |
2951 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2952 | * events. At the same time, make sure, having freq events does not change | |
2953 | * the rate of unthrottling as that would introduce bias. | |
2954 | */ | |
2955 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2956 | int needs_unthr) | |
60db5e09 | 2957 | { |
cdd6c482 IM |
2958 | struct perf_event *event; |
2959 | struct hw_perf_event *hwc; | |
e050e3f0 | 2960 | u64 now, period = TICK_NSEC; |
abd50713 | 2961 | s64 delta; |
60db5e09 | 2962 | |
e050e3f0 SE |
2963 | /* |
2964 | * only need to iterate over all events iff: | |
2965 | * - context have events in frequency mode (needs freq adjust) | |
2966 | * - there are events to unthrottle on this cpu | |
2967 | */ | |
2968 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2969 | return; |
2970 | ||
e050e3f0 | 2971 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2972 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2973 | |
03541f8b | 2974 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2975 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2976 | continue; |
2977 | ||
5632ab12 | 2978 | if (!event_filter_match(event)) |
5d27c23d PZ |
2979 | continue; |
2980 | ||
44377277 AS |
2981 | perf_pmu_disable(event->pmu); |
2982 | ||
cdd6c482 | 2983 | hwc = &event->hw; |
6a24ed6c | 2984 | |
ae23bff1 | 2985 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2986 | hwc->interrupts = 0; |
cdd6c482 | 2987 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2988 | event->pmu->start(event, 0); |
a78ac325 PZ |
2989 | } |
2990 | ||
cdd6c482 | 2991 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2992 | goto next; |
60db5e09 | 2993 | |
e050e3f0 SE |
2994 | /* |
2995 | * stop the event and update event->count | |
2996 | */ | |
2997 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2998 | ||
e7850595 | 2999 | now = local64_read(&event->count); |
abd50713 PZ |
3000 | delta = now - hwc->freq_count_stamp; |
3001 | hwc->freq_count_stamp = now; | |
60db5e09 | 3002 | |
e050e3f0 SE |
3003 | /* |
3004 | * restart the event | |
3005 | * reload only if value has changed | |
f39d47ff SE |
3006 | * we have stopped the event so tell that |
3007 | * to perf_adjust_period() to avoid stopping it | |
3008 | * twice. | |
e050e3f0 | 3009 | */ |
abd50713 | 3010 | if (delta > 0) |
f39d47ff | 3011 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3012 | |
3013 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3014 | next: |
3015 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3016 | } |
e050e3f0 | 3017 | |
f39d47ff | 3018 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3019 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3020 | } |
3021 | ||
235c7fc7 | 3022 | /* |
cdd6c482 | 3023 | * Round-robin a context's events: |
235c7fc7 | 3024 | */ |
cdd6c482 | 3025 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3026 | { |
dddd3379 TG |
3027 | /* |
3028 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3029 | * disabled by the inheritance code. | |
3030 | */ | |
3031 | if (!ctx->rotate_disable) | |
3032 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3033 | } |
3034 | ||
9e630205 | 3035 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3036 | { |
8dc85d54 | 3037 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3038 | int rotate = 0; |
7fc23a53 | 3039 | |
b5ab4cd5 | 3040 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3041 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3042 | rotate = 1; | |
3043 | } | |
235c7fc7 | 3044 | |
8dc85d54 | 3045 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3046 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3047 | if (ctx->nr_events != ctx->nr_active) |
3048 | rotate = 1; | |
3049 | } | |
9717e6cd | 3050 | |
e050e3f0 | 3051 | if (!rotate) |
0f5a2601 PZ |
3052 | goto done; |
3053 | ||
facc4307 | 3054 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3055 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3056 | |
e050e3f0 SE |
3057 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3058 | if (ctx) | |
3059 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3060 | |
e050e3f0 SE |
3061 | rotate_ctx(&cpuctx->ctx); |
3062 | if (ctx) | |
3063 | rotate_ctx(ctx); | |
235c7fc7 | 3064 | |
e050e3f0 | 3065 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3066 | |
0f5a2601 PZ |
3067 | perf_pmu_enable(cpuctx->ctx.pmu); |
3068 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3069 | done: |
9e630205 SE |
3070 | |
3071 | return rotate; | |
e9d2b064 PZ |
3072 | } |
3073 | ||
026249ef FW |
3074 | #ifdef CONFIG_NO_HZ_FULL |
3075 | bool perf_event_can_stop_tick(void) | |
3076 | { | |
948b26b6 | 3077 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3078 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3079 | return false; |
d84153d6 FW |
3080 | else |
3081 | return true; | |
026249ef FW |
3082 | } |
3083 | #endif | |
3084 | ||
e9d2b064 PZ |
3085 | void perf_event_task_tick(void) |
3086 | { | |
2fde4f94 MR |
3087 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3088 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3089 | int throttled; |
b5ab4cd5 | 3090 | |
e9d2b064 PZ |
3091 | WARN_ON(!irqs_disabled()); |
3092 | ||
e050e3f0 SE |
3093 | __this_cpu_inc(perf_throttled_seq); |
3094 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3095 | ||
2fde4f94 | 3096 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3097 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3098 | } |
3099 | ||
889ff015 FW |
3100 | static int event_enable_on_exec(struct perf_event *event, |
3101 | struct perf_event_context *ctx) | |
3102 | { | |
3103 | if (!event->attr.enable_on_exec) | |
3104 | return 0; | |
3105 | ||
3106 | event->attr.enable_on_exec = 0; | |
3107 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3108 | return 0; | |
3109 | ||
1d9b482e | 3110 | __perf_event_mark_enabled(event); |
889ff015 FW |
3111 | |
3112 | return 1; | |
3113 | } | |
3114 | ||
57e7986e | 3115 | /* |
cdd6c482 | 3116 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3117 | * This expects task == current. |
3118 | */ | |
c1274499 | 3119 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3120 | { |
c1274499 | 3121 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3122 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3123 | struct perf_event *event; |
57e7986e PM |
3124 | unsigned long flags; |
3125 | int enabled = 0; | |
3126 | ||
3127 | local_irq_save(flags); | |
c1274499 | 3128 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3129 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3130 | goto out; |
3131 | ||
3e349507 PZ |
3132 | cpuctx = __get_cpu_context(ctx); |
3133 | perf_ctx_lock(cpuctx, ctx); | |
3134 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3135 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3136 | |
3137 | /* | |
3e349507 | 3138 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3139 | */ |
3e349507 | 3140 | if (enabled) { |
211de6eb | 3141 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3142 | ctx_resched(cpuctx, ctx); |
3143 | } | |
3144 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3145 | |
9ed6060d | 3146 | out: |
57e7986e | 3147 | local_irq_restore(flags); |
211de6eb PZ |
3148 | |
3149 | if (clone_ctx) | |
3150 | put_ctx(clone_ctx); | |
57e7986e PM |
3151 | } |
3152 | ||
e041e328 PZ |
3153 | void perf_event_exec(void) |
3154 | { | |
e041e328 PZ |
3155 | int ctxn; |
3156 | ||
3157 | rcu_read_lock(); | |
c1274499 PZ |
3158 | for_each_task_context_nr(ctxn) |
3159 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3160 | rcu_read_unlock(); |
3161 | } | |
3162 | ||
0492d4c5 PZ |
3163 | struct perf_read_data { |
3164 | struct perf_event *event; | |
3165 | bool group; | |
7d88962e | 3166 | int ret; |
0492d4c5 PZ |
3167 | }; |
3168 | ||
0793a61d | 3169 | /* |
cdd6c482 | 3170 | * Cross CPU call to read the hardware event |
0793a61d | 3171 | */ |
cdd6c482 | 3172 | static void __perf_event_read(void *info) |
0793a61d | 3173 | { |
0492d4c5 PZ |
3174 | struct perf_read_data *data = info; |
3175 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3176 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3177 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3178 | struct pmu *pmu = event->pmu; |
621a01ea | 3179 | |
e1ac3614 PM |
3180 | /* |
3181 | * If this is a task context, we need to check whether it is | |
3182 | * the current task context of this cpu. If not it has been | |
3183 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3184 | * event->count would have been updated to a recent sample |
3185 | * when the event was scheduled out. | |
e1ac3614 PM |
3186 | */ |
3187 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3188 | return; | |
3189 | ||
e625cce1 | 3190 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3191 | if (ctx->is_active) { |
542e72fc | 3192 | update_context_time(ctx); |
e5d1367f SE |
3193 | update_cgrp_time_from_event(event); |
3194 | } | |
0492d4c5 | 3195 | |
cdd6c482 | 3196 | update_event_times(event); |
4a00c16e SB |
3197 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3198 | goto unlock; | |
0492d4c5 | 3199 | |
4a00c16e SB |
3200 | if (!data->group) { |
3201 | pmu->read(event); | |
3202 | data->ret = 0; | |
0492d4c5 | 3203 | goto unlock; |
4a00c16e SB |
3204 | } |
3205 | ||
3206 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3207 | ||
3208 | pmu->read(event); | |
0492d4c5 PZ |
3209 | |
3210 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3211 | update_event_times(sub); | |
4a00c16e SB |
3212 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3213 | /* | |
3214 | * Use sibling's PMU rather than @event's since | |
3215 | * sibling could be on different (eg: software) PMU. | |
3216 | */ | |
0492d4c5 | 3217 | sub->pmu->read(sub); |
4a00c16e | 3218 | } |
0492d4c5 | 3219 | } |
4a00c16e SB |
3220 | |
3221 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3222 | |
3223 | unlock: | |
e625cce1 | 3224 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3225 | } |
3226 | ||
b5e58793 PZ |
3227 | static inline u64 perf_event_count(struct perf_event *event) |
3228 | { | |
eacd3ecc MF |
3229 | if (event->pmu->count) |
3230 | return event->pmu->count(event); | |
3231 | ||
3232 | return __perf_event_count(event); | |
b5e58793 PZ |
3233 | } |
3234 | ||
ffe8690c KX |
3235 | /* |
3236 | * NMI-safe method to read a local event, that is an event that | |
3237 | * is: | |
3238 | * - either for the current task, or for this CPU | |
3239 | * - does not have inherit set, for inherited task events | |
3240 | * will not be local and we cannot read them atomically | |
3241 | * - must not have a pmu::count method | |
3242 | */ | |
3243 | u64 perf_event_read_local(struct perf_event *event) | |
3244 | { | |
3245 | unsigned long flags; | |
3246 | u64 val; | |
3247 | ||
3248 | /* | |
3249 | * Disabling interrupts avoids all counter scheduling (context | |
3250 | * switches, timer based rotation and IPIs). | |
3251 | */ | |
3252 | local_irq_save(flags); | |
3253 | ||
3254 | /* If this is a per-task event, it must be for current */ | |
3255 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3256 | event->hw.target != current); | |
3257 | ||
3258 | /* If this is a per-CPU event, it must be for this CPU */ | |
3259 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3260 | event->cpu != smp_processor_id()); | |
3261 | ||
3262 | /* | |
3263 | * It must not be an event with inherit set, we cannot read | |
3264 | * all child counters from atomic context. | |
3265 | */ | |
3266 | WARN_ON_ONCE(event->attr.inherit); | |
3267 | ||
3268 | /* | |
3269 | * It must not have a pmu::count method, those are not | |
3270 | * NMI safe. | |
3271 | */ | |
3272 | WARN_ON_ONCE(event->pmu->count); | |
3273 | ||
3274 | /* | |
3275 | * If the event is currently on this CPU, its either a per-task event, | |
3276 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3277 | * oncpu == -1). | |
3278 | */ | |
3279 | if (event->oncpu == smp_processor_id()) | |
3280 | event->pmu->read(event); | |
3281 | ||
3282 | val = local64_read(&event->count); | |
3283 | local_irq_restore(flags); | |
3284 | ||
3285 | return val; | |
3286 | } | |
3287 | ||
7d88962e | 3288 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3289 | { |
7d88962e SB |
3290 | int ret = 0; |
3291 | ||
0793a61d | 3292 | /* |
cdd6c482 IM |
3293 | * If event is enabled and currently active on a CPU, update the |
3294 | * value in the event structure: | |
0793a61d | 3295 | */ |
cdd6c482 | 3296 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3297 | struct perf_read_data data = { |
3298 | .event = event, | |
3299 | .group = group, | |
7d88962e | 3300 | .ret = 0, |
0492d4c5 | 3301 | }; |
cdd6c482 | 3302 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3303 | __perf_event_read, &data, 1); |
7d88962e | 3304 | ret = data.ret; |
cdd6c482 | 3305 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3306 | struct perf_event_context *ctx = event->ctx; |
3307 | unsigned long flags; | |
3308 | ||
e625cce1 | 3309 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3310 | /* |
3311 | * may read while context is not active | |
3312 | * (e.g., thread is blocked), in that case | |
3313 | * we cannot update context time | |
3314 | */ | |
e5d1367f | 3315 | if (ctx->is_active) { |
c530ccd9 | 3316 | update_context_time(ctx); |
e5d1367f SE |
3317 | update_cgrp_time_from_event(event); |
3318 | } | |
0492d4c5 PZ |
3319 | if (group) |
3320 | update_group_times(event); | |
3321 | else | |
3322 | update_event_times(event); | |
e625cce1 | 3323 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3324 | } |
7d88962e SB |
3325 | |
3326 | return ret; | |
0793a61d TG |
3327 | } |
3328 | ||
a63eaf34 | 3329 | /* |
cdd6c482 | 3330 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3331 | */ |
eb184479 | 3332 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3333 | { |
e625cce1 | 3334 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3335 | mutex_init(&ctx->mutex); |
2fde4f94 | 3336 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3337 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3338 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3339 | INIT_LIST_HEAD(&ctx->event_list); |
3340 | atomic_set(&ctx->refcount, 1); | |
fadfe7be | 3341 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); |
eb184479 PZ |
3342 | } |
3343 | ||
3344 | static struct perf_event_context * | |
3345 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3346 | { | |
3347 | struct perf_event_context *ctx; | |
3348 | ||
3349 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3350 | if (!ctx) | |
3351 | return NULL; | |
3352 | ||
3353 | __perf_event_init_context(ctx); | |
3354 | if (task) { | |
3355 | ctx->task = task; | |
3356 | get_task_struct(task); | |
0793a61d | 3357 | } |
eb184479 PZ |
3358 | ctx->pmu = pmu; |
3359 | ||
3360 | return ctx; | |
a63eaf34 PM |
3361 | } |
3362 | ||
2ebd4ffb MH |
3363 | static struct task_struct * |
3364 | find_lively_task_by_vpid(pid_t vpid) | |
3365 | { | |
3366 | struct task_struct *task; | |
3367 | int err; | |
0793a61d TG |
3368 | |
3369 | rcu_read_lock(); | |
2ebd4ffb | 3370 | if (!vpid) |
0793a61d TG |
3371 | task = current; |
3372 | else | |
2ebd4ffb | 3373 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3374 | if (task) |
3375 | get_task_struct(task); | |
3376 | rcu_read_unlock(); | |
3377 | ||
3378 | if (!task) | |
3379 | return ERR_PTR(-ESRCH); | |
3380 | ||
0793a61d | 3381 | /* Reuse ptrace permission checks for now. */ |
c93f7669 PM |
3382 | err = -EACCES; |
3383 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3384 | goto errout; | |
3385 | ||
2ebd4ffb MH |
3386 | return task; |
3387 | errout: | |
3388 | put_task_struct(task); | |
3389 | return ERR_PTR(err); | |
3390 | ||
3391 | } | |
3392 | ||
fe4b04fa PZ |
3393 | /* |
3394 | * Returns a matching context with refcount and pincount. | |
3395 | */ | |
108b02cf | 3396 | static struct perf_event_context * |
4af57ef2 YZ |
3397 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3398 | struct perf_event *event) | |
0793a61d | 3399 | { |
211de6eb | 3400 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3401 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3402 | void *task_ctx_data = NULL; |
25346b93 | 3403 | unsigned long flags; |
8dc85d54 | 3404 | int ctxn, err; |
4af57ef2 | 3405 | int cpu = event->cpu; |
0793a61d | 3406 | |
22a4ec72 | 3407 | if (!task) { |
cdd6c482 | 3408 | /* Must be root to operate on a CPU event: */ |
0764771d | 3409 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3410 | return ERR_PTR(-EACCES); |
3411 | ||
0793a61d | 3412 | /* |
cdd6c482 | 3413 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3414 | * offline CPU and activate it when the CPU comes up, but |
3415 | * that's for later. | |
3416 | */ | |
f6325e30 | 3417 | if (!cpu_online(cpu)) |
0793a61d TG |
3418 | return ERR_PTR(-ENODEV); |
3419 | ||
108b02cf | 3420 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3421 | ctx = &cpuctx->ctx; |
c93f7669 | 3422 | get_ctx(ctx); |
fe4b04fa | 3423 | ++ctx->pin_count; |
0793a61d | 3424 | |
0793a61d TG |
3425 | return ctx; |
3426 | } | |
3427 | ||
8dc85d54 PZ |
3428 | err = -EINVAL; |
3429 | ctxn = pmu->task_ctx_nr; | |
3430 | if (ctxn < 0) | |
3431 | goto errout; | |
3432 | ||
4af57ef2 YZ |
3433 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3434 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3435 | if (!task_ctx_data) { | |
3436 | err = -ENOMEM; | |
3437 | goto errout; | |
3438 | } | |
3439 | } | |
3440 | ||
9ed6060d | 3441 | retry: |
8dc85d54 | 3442 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3443 | if (ctx) { |
211de6eb | 3444 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3445 | ++ctx->pin_count; |
4af57ef2 YZ |
3446 | |
3447 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3448 | ctx->task_ctx_data = task_ctx_data; | |
3449 | task_ctx_data = NULL; | |
3450 | } | |
e625cce1 | 3451 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3452 | |
3453 | if (clone_ctx) | |
3454 | put_ctx(clone_ctx); | |
9137fb28 | 3455 | } else { |
eb184479 | 3456 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3457 | err = -ENOMEM; |
3458 | if (!ctx) | |
3459 | goto errout; | |
eb184479 | 3460 | |
4af57ef2 YZ |
3461 | if (task_ctx_data) { |
3462 | ctx->task_ctx_data = task_ctx_data; | |
3463 | task_ctx_data = NULL; | |
3464 | } | |
3465 | ||
dbe08d82 ON |
3466 | err = 0; |
3467 | mutex_lock(&task->perf_event_mutex); | |
3468 | /* | |
3469 | * If it has already passed perf_event_exit_task(). | |
3470 | * we must see PF_EXITING, it takes this mutex too. | |
3471 | */ | |
3472 | if (task->flags & PF_EXITING) | |
3473 | err = -ESRCH; | |
3474 | else if (task->perf_event_ctxp[ctxn]) | |
3475 | err = -EAGAIN; | |
fe4b04fa | 3476 | else { |
9137fb28 | 3477 | get_ctx(ctx); |
fe4b04fa | 3478 | ++ctx->pin_count; |
dbe08d82 | 3479 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3480 | } |
dbe08d82 ON |
3481 | mutex_unlock(&task->perf_event_mutex); |
3482 | ||
3483 | if (unlikely(err)) { | |
9137fb28 | 3484 | put_ctx(ctx); |
dbe08d82 ON |
3485 | |
3486 | if (err == -EAGAIN) | |
3487 | goto retry; | |
3488 | goto errout; | |
a63eaf34 PM |
3489 | } |
3490 | } | |
3491 | ||
4af57ef2 | 3492 | kfree(task_ctx_data); |
0793a61d | 3493 | return ctx; |
c93f7669 | 3494 | |
9ed6060d | 3495 | errout: |
4af57ef2 | 3496 | kfree(task_ctx_data); |
c93f7669 | 3497 | return ERR_PTR(err); |
0793a61d TG |
3498 | } |
3499 | ||
6fb2915d | 3500 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3501 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3502 | |
cdd6c482 | 3503 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3504 | { |
cdd6c482 | 3505 | struct perf_event *event; |
592903cd | 3506 | |
cdd6c482 IM |
3507 | event = container_of(head, struct perf_event, rcu_head); |
3508 | if (event->ns) | |
3509 | put_pid_ns(event->ns); | |
6fb2915d | 3510 | perf_event_free_filter(event); |
cdd6c482 | 3511 | kfree(event); |
592903cd PZ |
3512 | } |
3513 | ||
b69cf536 PZ |
3514 | static void ring_buffer_attach(struct perf_event *event, |
3515 | struct ring_buffer *rb); | |
925d519a | 3516 | |
4beb31f3 | 3517 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3518 | { |
4beb31f3 FW |
3519 | if (event->parent) |
3520 | return; | |
3521 | ||
4beb31f3 FW |
3522 | if (is_cgroup_event(event)) |
3523 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3524 | } | |
925d519a | 3525 | |
4beb31f3 FW |
3526 | static void unaccount_event(struct perf_event *event) |
3527 | { | |
25432ae9 PZ |
3528 | bool dec = false; |
3529 | ||
4beb31f3 FW |
3530 | if (event->parent) |
3531 | return; | |
3532 | ||
3533 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3534 | dec = true; |
4beb31f3 FW |
3535 | if (event->attr.mmap || event->attr.mmap_data) |
3536 | atomic_dec(&nr_mmap_events); | |
3537 | if (event->attr.comm) | |
3538 | atomic_dec(&nr_comm_events); | |
3539 | if (event->attr.task) | |
3540 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3541 | if (event->attr.freq) |
3542 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3543 | if (event->attr.context_switch) { |
25432ae9 | 3544 | dec = true; |
45ac1403 AH |
3545 | atomic_dec(&nr_switch_events); |
3546 | } | |
4beb31f3 | 3547 | if (is_cgroup_event(event)) |
25432ae9 | 3548 | dec = true; |
4beb31f3 | 3549 | if (has_branch_stack(event)) |
25432ae9 PZ |
3550 | dec = true; |
3551 | ||
3552 | if (dec) | |
4beb31f3 FW |
3553 | static_key_slow_dec_deferred(&perf_sched_events); |
3554 | ||
3555 | unaccount_event_cpu(event, event->cpu); | |
3556 | } | |
925d519a | 3557 | |
bed5b25a AS |
3558 | /* |
3559 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3560 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3561 | * at a time, so we disallow creating events that might conflict, namely: | |
3562 | * | |
3563 | * 1) cpu-wide events in the presence of per-task events, | |
3564 | * 2) per-task events in the presence of cpu-wide events, | |
3565 | * 3) two matching events on the same context. | |
3566 | * | |
3567 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
3568 | * __free_event()), the latter -- before the first perf_install_in_context(). | |
3569 | */ | |
3570 | static int exclusive_event_init(struct perf_event *event) | |
3571 | { | |
3572 | struct pmu *pmu = event->pmu; | |
3573 | ||
3574 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3575 | return 0; | |
3576 | ||
3577 | /* | |
3578 | * Prevent co-existence of per-task and cpu-wide events on the | |
3579 | * same exclusive pmu. | |
3580 | * | |
3581 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3582 | * events on this "exclusive" pmu, positive means there are | |
3583 | * per-task events. | |
3584 | * | |
3585 | * Since this is called in perf_event_alloc() path, event::ctx | |
3586 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3587 | * to mean "per-task event", because unlike other attach states it | |
3588 | * never gets cleared. | |
3589 | */ | |
3590 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3591 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3592 | return -EBUSY; | |
3593 | } else { | |
3594 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3595 | return -EBUSY; | |
3596 | } | |
3597 | ||
3598 | return 0; | |
3599 | } | |
3600 | ||
3601 | static void exclusive_event_destroy(struct perf_event *event) | |
3602 | { | |
3603 | struct pmu *pmu = event->pmu; | |
3604 | ||
3605 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3606 | return; | |
3607 | ||
3608 | /* see comment in exclusive_event_init() */ | |
3609 | if (event->attach_state & PERF_ATTACH_TASK) | |
3610 | atomic_dec(&pmu->exclusive_cnt); | |
3611 | else | |
3612 | atomic_inc(&pmu->exclusive_cnt); | |
3613 | } | |
3614 | ||
3615 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3616 | { | |
3617 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3618 | (e1->cpu == e2->cpu || | |
3619 | e1->cpu == -1 || | |
3620 | e2->cpu == -1)) | |
3621 | return true; | |
3622 | return false; | |
3623 | } | |
3624 | ||
3625 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3626 | static bool exclusive_event_installable(struct perf_event *event, | |
3627 | struct perf_event_context *ctx) | |
3628 | { | |
3629 | struct perf_event *iter_event; | |
3630 | struct pmu *pmu = event->pmu; | |
3631 | ||
3632 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3633 | return true; | |
3634 | ||
3635 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3636 | if (exclusive_event_match(iter_event, event)) | |
3637 | return false; | |
3638 | } | |
3639 | ||
3640 | return true; | |
3641 | } | |
3642 | ||
766d6c07 FW |
3643 | static void __free_event(struct perf_event *event) |
3644 | { | |
cdd6c482 | 3645 | if (!event->parent) { |
927c7a9e FW |
3646 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3647 | put_callchain_buffers(); | |
f344011c | 3648 | } |
9ee318a7 | 3649 | |
dead9f29 AS |
3650 | perf_event_free_bpf_prog(event); |
3651 | ||
766d6c07 FW |
3652 | if (event->destroy) |
3653 | event->destroy(event); | |
3654 | ||
3655 | if (event->ctx) | |
3656 | put_ctx(event->ctx); | |
3657 | ||
bed5b25a AS |
3658 | if (event->pmu) { |
3659 | exclusive_event_destroy(event); | |
c464c76e | 3660 | module_put(event->pmu->module); |
bed5b25a | 3661 | } |
c464c76e | 3662 | |
766d6c07 FW |
3663 | call_rcu(&event->rcu_head, free_event_rcu); |
3664 | } | |
683ede43 PZ |
3665 | |
3666 | static void _free_event(struct perf_event *event) | |
f1600952 | 3667 | { |
e360adbe | 3668 | irq_work_sync(&event->pending); |
925d519a | 3669 | |
4beb31f3 | 3670 | unaccount_event(event); |
9ee318a7 | 3671 | |
76369139 | 3672 | if (event->rb) { |
9bb5d40c PZ |
3673 | /* |
3674 | * Can happen when we close an event with re-directed output. | |
3675 | * | |
3676 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3677 | * over us; possibly making our ring_buffer_put() the last. | |
3678 | */ | |
3679 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3680 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3681 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3682 | } |
3683 | ||
e5d1367f SE |
3684 | if (is_cgroup_event(event)) |
3685 | perf_detach_cgroup(event); | |
3686 | ||
766d6c07 | 3687 | __free_event(event); |
f1600952 PZ |
3688 | } |
3689 | ||
683ede43 PZ |
3690 | /* |
3691 | * Used to free events which have a known refcount of 1, such as in error paths | |
3692 | * where the event isn't exposed yet and inherited events. | |
3693 | */ | |
3694 | static void free_event(struct perf_event *event) | |
0793a61d | 3695 | { |
683ede43 PZ |
3696 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3697 | "unexpected event refcount: %ld; ptr=%p\n", | |
3698 | atomic_long_read(&event->refcount), event)) { | |
3699 | /* leak to avoid use-after-free */ | |
3700 | return; | |
3701 | } | |
0793a61d | 3702 | |
683ede43 | 3703 | _free_event(event); |
0793a61d TG |
3704 | } |
3705 | ||
a66a3052 | 3706 | /* |
f8697762 | 3707 | * Remove user event from the owner task. |
a66a3052 | 3708 | */ |
f8697762 | 3709 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3710 | { |
8882135b | 3711 | struct task_struct *owner; |
fb0459d7 | 3712 | |
8882135b PZ |
3713 | rcu_read_lock(); |
3714 | owner = ACCESS_ONCE(event->owner); | |
3715 | /* | |
3716 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3717 | * !owner it means the list deletion is complete and we can indeed | |
3718 | * free this event, otherwise we need to serialize on | |
3719 | * owner->perf_event_mutex. | |
3720 | */ | |
3721 | smp_read_barrier_depends(); | |
3722 | if (owner) { | |
3723 | /* | |
3724 | * Since delayed_put_task_struct() also drops the last | |
3725 | * task reference we can safely take a new reference | |
3726 | * while holding the rcu_read_lock(). | |
3727 | */ | |
3728 | get_task_struct(owner); | |
3729 | } | |
3730 | rcu_read_unlock(); | |
3731 | ||
3732 | if (owner) { | |
f63a8daa PZ |
3733 | /* |
3734 | * If we're here through perf_event_exit_task() we're already | |
3735 | * holding ctx->mutex which would be an inversion wrt. the | |
3736 | * normal lock order. | |
3737 | * | |
3738 | * However we can safely take this lock because its the child | |
3739 | * ctx->mutex. | |
3740 | */ | |
3741 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3742 | ||
8882135b PZ |
3743 | /* |
3744 | * We have to re-check the event->owner field, if it is cleared | |
3745 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3746 | * ensured they're done, and we can proceed with freeing the | |
3747 | * event. | |
3748 | */ | |
3749 | if (event->owner) | |
3750 | list_del_init(&event->owner_entry); | |
3751 | mutex_unlock(&owner->perf_event_mutex); | |
3752 | put_task_struct(owner); | |
3753 | } | |
f8697762 JO |
3754 | } |
3755 | ||
f8697762 JO |
3756 | static void put_event(struct perf_event *event) |
3757 | { | |
a83fe28e | 3758 | struct perf_event_context *ctx; |
f8697762 JO |
3759 | |
3760 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3761 | return; | |
3762 | ||
3763 | if (!is_kernel_event(event)) | |
3764 | perf_remove_from_owner(event); | |
8882135b | 3765 | |
683ede43 PZ |
3766 | /* |
3767 | * There are two ways this annotation is useful: | |
3768 | * | |
3769 | * 1) there is a lock recursion from perf_event_exit_task | |
3770 | * see the comment there. | |
3771 | * | |
3772 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3773 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3774 | * holding ctx->mutex, however this is called after |
3775 | * the last filedesc died, so there is no possibility | |
3776 | * to trigger the AB-BA case. | |
3777 | */ | |
a83fe28e PZ |
3778 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3779 | WARN_ON_ONCE(ctx->parent_ctx); | |
683ede43 | 3780 | perf_remove_from_context(event, true); |
d415a7f1 | 3781 | perf_event_ctx_unlock(event, ctx); |
683ede43 PZ |
3782 | |
3783 | _free_event(event); | |
a6fa941d AV |
3784 | } |
3785 | ||
683ede43 PZ |
3786 | int perf_event_release_kernel(struct perf_event *event) |
3787 | { | |
3788 | put_event(event); | |
3789 | return 0; | |
3790 | } | |
3791 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3792 | ||
8b10c5e2 PZ |
3793 | /* |
3794 | * Called when the last reference to the file is gone. | |
3795 | */ | |
a6fa941d AV |
3796 | static int perf_release(struct inode *inode, struct file *file) |
3797 | { | |
3798 | put_event(file->private_data); | |
3799 | return 0; | |
fb0459d7 | 3800 | } |
fb0459d7 | 3801 | |
fadfe7be JO |
3802 | /* |
3803 | * Remove all orphanes events from the context. | |
3804 | */ | |
3805 | static void orphans_remove_work(struct work_struct *work) | |
3806 | { | |
3807 | struct perf_event_context *ctx; | |
3808 | struct perf_event *event, *tmp; | |
3809 | ||
3810 | ctx = container_of(work, struct perf_event_context, | |
3811 | orphans_remove.work); | |
3812 | ||
3813 | mutex_lock(&ctx->mutex); | |
3814 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3815 | struct perf_event *parent_event = event->parent; | |
3816 | ||
3817 | if (!is_orphaned_child(event)) | |
3818 | continue; | |
3819 | ||
3820 | perf_remove_from_context(event, true); | |
3821 | ||
3822 | mutex_lock(&parent_event->child_mutex); | |
3823 | list_del_init(&event->child_list); | |
3824 | mutex_unlock(&parent_event->child_mutex); | |
3825 | ||
3826 | free_event(event); | |
3827 | put_event(parent_event); | |
3828 | } | |
3829 | ||
3830 | raw_spin_lock_irq(&ctx->lock); | |
3831 | ctx->orphans_remove_sched = false; | |
3832 | raw_spin_unlock_irq(&ctx->lock); | |
3833 | mutex_unlock(&ctx->mutex); | |
3834 | ||
3835 | put_ctx(ctx); | |
3836 | } | |
3837 | ||
59ed446f | 3838 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3839 | { |
cdd6c482 | 3840 | struct perf_event *child; |
e53c0994 PZ |
3841 | u64 total = 0; |
3842 | ||
59ed446f PZ |
3843 | *enabled = 0; |
3844 | *running = 0; | |
3845 | ||
6f10581a | 3846 | mutex_lock(&event->child_mutex); |
01add3ea | 3847 | |
7d88962e | 3848 | (void)perf_event_read(event, false); |
01add3ea SB |
3849 | total += perf_event_count(event); |
3850 | ||
59ed446f PZ |
3851 | *enabled += event->total_time_enabled + |
3852 | atomic64_read(&event->child_total_time_enabled); | |
3853 | *running += event->total_time_running + | |
3854 | atomic64_read(&event->child_total_time_running); | |
3855 | ||
3856 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3857 | (void)perf_event_read(child, false); |
01add3ea | 3858 | total += perf_event_count(child); |
59ed446f PZ |
3859 | *enabled += child->total_time_enabled; |
3860 | *running += child->total_time_running; | |
3861 | } | |
6f10581a | 3862 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3863 | |
3864 | return total; | |
3865 | } | |
fb0459d7 | 3866 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3867 | |
7d88962e | 3868 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3869 | u64 read_format, u64 *values) |
3dab77fb | 3870 | { |
fa8c2693 PZ |
3871 | struct perf_event *sub; |
3872 | int n = 1; /* skip @nr */ | |
7d88962e | 3873 | int ret; |
f63a8daa | 3874 | |
7d88962e SB |
3875 | ret = perf_event_read(leader, true); |
3876 | if (ret) | |
3877 | return ret; | |
abf4868b | 3878 | |
fa8c2693 PZ |
3879 | /* |
3880 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3881 | * will be identical to those of the leader, so we only publish one | |
3882 | * set. | |
3883 | */ | |
3884 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3885 | values[n++] += leader->total_time_enabled + | |
3886 | atomic64_read(&leader->child_total_time_enabled); | |
3887 | } | |
3dab77fb | 3888 | |
fa8c2693 PZ |
3889 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3890 | values[n++] += leader->total_time_running + | |
3891 | atomic64_read(&leader->child_total_time_running); | |
3892 | } | |
3893 | ||
3894 | /* | |
3895 | * Write {count,id} tuples for every sibling. | |
3896 | */ | |
3897 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3898 | if (read_format & PERF_FORMAT_ID) |
3899 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3900 | |
fa8c2693 PZ |
3901 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3902 | values[n++] += perf_event_count(sub); | |
3903 | if (read_format & PERF_FORMAT_ID) | |
3904 | values[n++] = primary_event_id(sub); | |
3905 | } | |
7d88962e SB |
3906 | |
3907 | return 0; | |
fa8c2693 | 3908 | } |
3dab77fb | 3909 | |
fa8c2693 PZ |
3910 | static int perf_read_group(struct perf_event *event, |
3911 | u64 read_format, char __user *buf) | |
3912 | { | |
3913 | struct perf_event *leader = event->group_leader, *child; | |
3914 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3915 | int ret; |
fa8c2693 | 3916 | u64 *values; |
3dab77fb | 3917 | |
fa8c2693 | 3918 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3919 | |
fa8c2693 PZ |
3920 | values = kzalloc(event->read_size, GFP_KERNEL); |
3921 | if (!values) | |
3922 | return -ENOMEM; | |
3dab77fb | 3923 | |
fa8c2693 PZ |
3924 | values[0] = 1 + leader->nr_siblings; |
3925 | ||
3926 | /* | |
3927 | * By locking the child_mutex of the leader we effectively | |
3928 | * lock the child list of all siblings.. XXX explain how. | |
3929 | */ | |
3930 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3931 | |
7d88962e SB |
3932 | ret = __perf_read_group_add(leader, read_format, values); |
3933 | if (ret) | |
3934 | goto unlock; | |
3935 | ||
3936 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3937 | ret = __perf_read_group_add(child, read_format, values); | |
3938 | if (ret) | |
3939 | goto unlock; | |
3940 | } | |
abf4868b | 3941 | |
fa8c2693 | 3942 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3943 | |
7d88962e | 3944 | ret = event->read_size; |
fa8c2693 PZ |
3945 | if (copy_to_user(buf, values, event->read_size)) |
3946 | ret = -EFAULT; | |
7d88962e | 3947 | goto out; |
fa8c2693 | 3948 | |
7d88962e SB |
3949 | unlock: |
3950 | mutex_unlock(&leader->child_mutex); | |
3951 | out: | |
fa8c2693 | 3952 | kfree(values); |
abf4868b | 3953 | return ret; |
3dab77fb PZ |
3954 | } |
3955 | ||
b15f495b | 3956 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3957 | u64 read_format, char __user *buf) |
3958 | { | |
59ed446f | 3959 | u64 enabled, running; |
3dab77fb PZ |
3960 | u64 values[4]; |
3961 | int n = 0; | |
3962 | ||
59ed446f PZ |
3963 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3964 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3965 | values[n++] = enabled; | |
3966 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3967 | values[n++] = running; | |
3dab77fb | 3968 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3969 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3970 | |
3971 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3972 | return -EFAULT; | |
3973 | ||
3974 | return n * sizeof(u64); | |
3975 | } | |
3976 | ||
dc633982 JO |
3977 | static bool is_event_hup(struct perf_event *event) |
3978 | { | |
3979 | bool no_children; | |
3980 | ||
3981 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3982 | return false; | |
3983 | ||
3984 | mutex_lock(&event->child_mutex); | |
3985 | no_children = list_empty(&event->child_list); | |
3986 | mutex_unlock(&event->child_mutex); | |
3987 | return no_children; | |
3988 | } | |
3989 | ||
0793a61d | 3990 | /* |
cdd6c482 | 3991 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3992 | */ |
3993 | static ssize_t | |
b15f495b | 3994 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3995 | { |
cdd6c482 | 3996 | u64 read_format = event->attr.read_format; |
3dab77fb | 3997 | int ret; |
0793a61d | 3998 | |
3b6f9e5c | 3999 | /* |
cdd6c482 | 4000 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4001 | * error state (i.e. because it was pinned but it couldn't be |
4002 | * scheduled on to the CPU at some point). | |
4003 | */ | |
cdd6c482 | 4004 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4005 | return 0; |
4006 | ||
c320c7b7 | 4007 | if (count < event->read_size) |
3dab77fb PZ |
4008 | return -ENOSPC; |
4009 | ||
cdd6c482 | 4010 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4011 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4012 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4013 | else |
b15f495b | 4014 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4015 | |
3dab77fb | 4016 | return ret; |
0793a61d TG |
4017 | } |
4018 | ||
0793a61d TG |
4019 | static ssize_t |
4020 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4021 | { | |
cdd6c482 | 4022 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4023 | struct perf_event_context *ctx; |
4024 | int ret; | |
0793a61d | 4025 | |
f63a8daa | 4026 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4027 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4028 | perf_event_ctx_unlock(event, ctx); |
4029 | ||
4030 | return ret; | |
0793a61d TG |
4031 | } |
4032 | ||
4033 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4034 | { | |
cdd6c482 | 4035 | struct perf_event *event = file->private_data; |
76369139 | 4036 | struct ring_buffer *rb; |
61b67684 | 4037 | unsigned int events = POLLHUP; |
c7138f37 | 4038 | |
e708d7ad | 4039 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4040 | |
dc633982 | 4041 | if (is_event_hup(event)) |
179033b3 | 4042 | return events; |
c7138f37 | 4043 | |
10c6db11 | 4044 | /* |
9bb5d40c PZ |
4045 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4046 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4047 | */ |
4048 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4049 | rb = event->rb; |
4050 | if (rb) | |
76369139 | 4051 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4052 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4053 | return events; |
4054 | } | |
4055 | ||
f63a8daa | 4056 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4057 | { |
7d88962e | 4058 | (void)perf_event_read(event, false); |
e7850595 | 4059 | local64_set(&event->count, 0); |
cdd6c482 | 4060 | perf_event_update_userpage(event); |
3df5edad PZ |
4061 | } |
4062 | ||
c93f7669 | 4063 | /* |
cdd6c482 IM |
4064 | * Holding the top-level event's child_mutex means that any |
4065 | * descendant process that has inherited this event will block | |
4066 | * in sync_child_event if it goes to exit, thus satisfying the | |
4067 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 4068 | */ |
cdd6c482 IM |
4069 | static void perf_event_for_each_child(struct perf_event *event, |
4070 | void (*func)(struct perf_event *)) | |
3df5edad | 4071 | { |
cdd6c482 | 4072 | struct perf_event *child; |
3df5edad | 4073 | |
cdd6c482 | 4074 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4075 | |
cdd6c482 IM |
4076 | mutex_lock(&event->child_mutex); |
4077 | func(event); | |
4078 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4079 | func(child); |
cdd6c482 | 4080 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4081 | } |
4082 | ||
cdd6c482 IM |
4083 | static void perf_event_for_each(struct perf_event *event, |
4084 | void (*func)(struct perf_event *)) | |
3df5edad | 4085 | { |
cdd6c482 IM |
4086 | struct perf_event_context *ctx = event->ctx; |
4087 | struct perf_event *sibling; | |
3df5edad | 4088 | |
f63a8daa PZ |
4089 | lockdep_assert_held(&ctx->mutex); |
4090 | ||
cdd6c482 | 4091 | event = event->group_leader; |
75f937f2 | 4092 | |
cdd6c482 | 4093 | perf_event_for_each_child(event, func); |
cdd6c482 | 4094 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4095 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4096 | } |
4097 | ||
c7999c6f PZ |
4098 | struct period_event { |
4099 | struct perf_event *event; | |
08247e31 | 4100 | u64 value; |
c7999c6f | 4101 | }; |
08247e31 | 4102 | |
0017960f PZ |
4103 | static void ___perf_event_period(void *info) |
4104 | { | |
4105 | struct period_event *pe = info; | |
4106 | struct perf_event *event = pe->event; | |
4107 | u64 value = pe->value; | |
4108 | ||
4109 | if (event->attr.freq) { | |
4110 | event->attr.sample_freq = value; | |
4111 | } else { | |
4112 | event->attr.sample_period = value; | |
4113 | event->hw.sample_period = value; | |
4114 | } | |
4115 | ||
4116 | local64_set(&event->hw.period_left, 0); | |
4117 | } | |
4118 | ||
c7999c6f PZ |
4119 | static int __perf_event_period(void *info) |
4120 | { | |
4121 | struct period_event *pe = info; | |
4122 | struct perf_event *event = pe->event; | |
4123 | struct perf_event_context *ctx = event->ctx; | |
4124 | u64 value = pe->value; | |
4125 | bool active; | |
08247e31 | 4126 | |
c7999c6f | 4127 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 4128 | if (event->attr.freq) { |
cdd6c482 | 4129 | event->attr.sample_freq = value; |
08247e31 | 4130 | } else { |
cdd6c482 IM |
4131 | event->attr.sample_period = value; |
4132 | event->hw.sample_period = value; | |
08247e31 | 4133 | } |
bad7192b PZ |
4134 | |
4135 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4136 | if (active) { | |
4137 | perf_pmu_disable(ctx->pmu); | |
4138 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4139 | } | |
4140 | ||
4141 | local64_set(&event->hw.period_left, 0); | |
4142 | ||
4143 | if (active) { | |
4144 | event->pmu->start(event, PERF_EF_RELOAD); | |
4145 | perf_pmu_enable(ctx->pmu); | |
4146 | } | |
c7999c6f | 4147 | raw_spin_unlock(&ctx->lock); |
bad7192b | 4148 | |
c7999c6f PZ |
4149 | return 0; |
4150 | } | |
4151 | ||
4152 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4153 | { | |
4154 | struct period_event pe = { .event = event, }; | |
c7999c6f PZ |
4155 | u64 value; |
4156 | ||
4157 | if (!is_sampling_event(event)) | |
4158 | return -EINVAL; | |
4159 | ||
4160 | if (copy_from_user(&value, arg, sizeof(value))) | |
4161 | return -EFAULT; | |
4162 | ||
4163 | if (!value) | |
4164 | return -EINVAL; | |
4165 | ||
4166 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4167 | return -EINVAL; | |
4168 | ||
c7999c6f PZ |
4169 | pe.value = value; |
4170 | ||
0017960f PZ |
4171 | event_function_call(event, __perf_event_period, |
4172 | ___perf_event_period, &pe); | |
08247e31 | 4173 | |
c7999c6f | 4174 | return 0; |
08247e31 PZ |
4175 | } |
4176 | ||
ac9721f3 PZ |
4177 | static const struct file_operations perf_fops; |
4178 | ||
2903ff01 | 4179 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4180 | { |
2903ff01 AV |
4181 | struct fd f = fdget(fd); |
4182 | if (!f.file) | |
4183 | return -EBADF; | |
ac9721f3 | 4184 | |
2903ff01 AV |
4185 | if (f.file->f_op != &perf_fops) { |
4186 | fdput(f); | |
4187 | return -EBADF; | |
ac9721f3 | 4188 | } |
2903ff01 AV |
4189 | *p = f; |
4190 | return 0; | |
ac9721f3 PZ |
4191 | } |
4192 | ||
4193 | static int perf_event_set_output(struct perf_event *event, | |
4194 | struct perf_event *output_event); | |
6fb2915d | 4195 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4196 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4197 | |
f63a8daa | 4198 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4199 | { |
cdd6c482 | 4200 | void (*func)(struct perf_event *); |
3df5edad | 4201 | u32 flags = arg; |
d859e29f PM |
4202 | |
4203 | switch (cmd) { | |
cdd6c482 | 4204 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4205 | func = _perf_event_enable; |
d859e29f | 4206 | break; |
cdd6c482 | 4207 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4208 | func = _perf_event_disable; |
79f14641 | 4209 | break; |
cdd6c482 | 4210 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4211 | func = _perf_event_reset; |
6de6a7b9 | 4212 | break; |
3df5edad | 4213 | |
cdd6c482 | 4214 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4215 | return _perf_event_refresh(event, arg); |
08247e31 | 4216 | |
cdd6c482 IM |
4217 | case PERF_EVENT_IOC_PERIOD: |
4218 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4219 | |
cf4957f1 JO |
4220 | case PERF_EVENT_IOC_ID: |
4221 | { | |
4222 | u64 id = primary_event_id(event); | |
4223 | ||
4224 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4225 | return -EFAULT; | |
4226 | return 0; | |
4227 | } | |
4228 | ||
cdd6c482 | 4229 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4230 | { |
ac9721f3 | 4231 | int ret; |
ac9721f3 | 4232 | if (arg != -1) { |
2903ff01 AV |
4233 | struct perf_event *output_event; |
4234 | struct fd output; | |
4235 | ret = perf_fget_light(arg, &output); | |
4236 | if (ret) | |
4237 | return ret; | |
4238 | output_event = output.file->private_data; | |
4239 | ret = perf_event_set_output(event, output_event); | |
4240 | fdput(output); | |
4241 | } else { | |
4242 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4243 | } |
ac9721f3 PZ |
4244 | return ret; |
4245 | } | |
a4be7c27 | 4246 | |
6fb2915d LZ |
4247 | case PERF_EVENT_IOC_SET_FILTER: |
4248 | return perf_event_set_filter(event, (void __user *)arg); | |
4249 | ||
2541517c AS |
4250 | case PERF_EVENT_IOC_SET_BPF: |
4251 | return perf_event_set_bpf_prog(event, arg); | |
4252 | ||
d859e29f | 4253 | default: |
3df5edad | 4254 | return -ENOTTY; |
d859e29f | 4255 | } |
3df5edad PZ |
4256 | |
4257 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4258 | perf_event_for_each(event, func); |
3df5edad | 4259 | else |
cdd6c482 | 4260 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4261 | |
4262 | return 0; | |
d859e29f PM |
4263 | } |
4264 | ||
f63a8daa PZ |
4265 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4266 | { | |
4267 | struct perf_event *event = file->private_data; | |
4268 | struct perf_event_context *ctx; | |
4269 | long ret; | |
4270 | ||
4271 | ctx = perf_event_ctx_lock(event); | |
4272 | ret = _perf_ioctl(event, cmd, arg); | |
4273 | perf_event_ctx_unlock(event, ctx); | |
4274 | ||
4275 | return ret; | |
4276 | } | |
4277 | ||
b3f20785 PM |
4278 | #ifdef CONFIG_COMPAT |
4279 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4280 | unsigned long arg) | |
4281 | { | |
4282 | switch (_IOC_NR(cmd)) { | |
4283 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4284 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4285 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4286 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4287 | cmd &= ~IOCSIZE_MASK; | |
4288 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4289 | } | |
4290 | break; | |
4291 | } | |
4292 | return perf_ioctl(file, cmd, arg); | |
4293 | } | |
4294 | #else | |
4295 | # define perf_compat_ioctl NULL | |
4296 | #endif | |
4297 | ||
cdd6c482 | 4298 | int perf_event_task_enable(void) |
771d7cde | 4299 | { |
f63a8daa | 4300 | struct perf_event_context *ctx; |
cdd6c482 | 4301 | struct perf_event *event; |
771d7cde | 4302 | |
cdd6c482 | 4303 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4304 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4305 | ctx = perf_event_ctx_lock(event); | |
4306 | perf_event_for_each_child(event, _perf_event_enable); | |
4307 | perf_event_ctx_unlock(event, ctx); | |
4308 | } | |
cdd6c482 | 4309 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4310 | |
4311 | return 0; | |
4312 | } | |
4313 | ||
cdd6c482 | 4314 | int perf_event_task_disable(void) |
771d7cde | 4315 | { |
f63a8daa | 4316 | struct perf_event_context *ctx; |
cdd6c482 | 4317 | struct perf_event *event; |
771d7cde | 4318 | |
cdd6c482 | 4319 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4320 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4321 | ctx = perf_event_ctx_lock(event); | |
4322 | perf_event_for_each_child(event, _perf_event_disable); | |
4323 | perf_event_ctx_unlock(event, ctx); | |
4324 | } | |
cdd6c482 | 4325 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4326 | |
4327 | return 0; | |
4328 | } | |
4329 | ||
cdd6c482 | 4330 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4331 | { |
a4eaf7f1 PZ |
4332 | if (event->hw.state & PERF_HES_STOPPED) |
4333 | return 0; | |
4334 | ||
cdd6c482 | 4335 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4336 | return 0; |
4337 | ||
35edc2a5 | 4338 | return event->pmu->event_idx(event); |
194002b2 PZ |
4339 | } |
4340 | ||
c4794295 | 4341 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4342 | u64 *now, |
7f310a5d EM |
4343 | u64 *enabled, |
4344 | u64 *running) | |
c4794295 | 4345 | { |
e3f3541c | 4346 | u64 ctx_time; |
c4794295 | 4347 | |
e3f3541c PZ |
4348 | *now = perf_clock(); |
4349 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4350 | *enabled = ctx_time - event->tstamp_enabled; |
4351 | *running = ctx_time - event->tstamp_running; | |
4352 | } | |
4353 | ||
fa731587 PZ |
4354 | static void perf_event_init_userpage(struct perf_event *event) |
4355 | { | |
4356 | struct perf_event_mmap_page *userpg; | |
4357 | struct ring_buffer *rb; | |
4358 | ||
4359 | rcu_read_lock(); | |
4360 | rb = rcu_dereference(event->rb); | |
4361 | if (!rb) | |
4362 | goto unlock; | |
4363 | ||
4364 | userpg = rb->user_page; | |
4365 | ||
4366 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4367 | userpg->cap_bit0_is_deprecated = 1; | |
4368 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4369 | userpg->data_offset = PAGE_SIZE; |
4370 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4371 | |
4372 | unlock: | |
4373 | rcu_read_unlock(); | |
4374 | } | |
4375 | ||
c1317ec2 AL |
4376 | void __weak arch_perf_update_userpage( |
4377 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4378 | { |
4379 | } | |
4380 | ||
38ff667b PZ |
4381 | /* |
4382 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4383 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4384 | * code calls this from NMI context. | |
4385 | */ | |
cdd6c482 | 4386 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4387 | { |
cdd6c482 | 4388 | struct perf_event_mmap_page *userpg; |
76369139 | 4389 | struct ring_buffer *rb; |
e3f3541c | 4390 | u64 enabled, running, now; |
38ff667b PZ |
4391 | |
4392 | rcu_read_lock(); | |
5ec4c599 PZ |
4393 | rb = rcu_dereference(event->rb); |
4394 | if (!rb) | |
4395 | goto unlock; | |
4396 | ||
0d641208 EM |
4397 | /* |
4398 | * compute total_time_enabled, total_time_running | |
4399 | * based on snapshot values taken when the event | |
4400 | * was last scheduled in. | |
4401 | * | |
4402 | * we cannot simply called update_context_time() | |
4403 | * because of locking issue as we can be called in | |
4404 | * NMI context | |
4405 | */ | |
e3f3541c | 4406 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4407 | |
76369139 | 4408 | userpg = rb->user_page; |
7b732a75 PZ |
4409 | /* |
4410 | * Disable preemption so as to not let the corresponding user-space | |
4411 | * spin too long if we get preempted. | |
4412 | */ | |
4413 | preempt_disable(); | |
37d81828 | 4414 | ++userpg->lock; |
92f22a38 | 4415 | barrier(); |
cdd6c482 | 4416 | userpg->index = perf_event_index(event); |
b5e58793 | 4417 | userpg->offset = perf_event_count(event); |
365a4038 | 4418 | if (userpg->index) |
e7850595 | 4419 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4420 | |
0d641208 | 4421 | userpg->time_enabled = enabled + |
cdd6c482 | 4422 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4423 | |
0d641208 | 4424 | userpg->time_running = running + |
cdd6c482 | 4425 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4426 | |
c1317ec2 | 4427 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4428 | |
92f22a38 | 4429 | barrier(); |
37d81828 | 4430 | ++userpg->lock; |
7b732a75 | 4431 | preempt_enable(); |
38ff667b | 4432 | unlock: |
7b732a75 | 4433 | rcu_read_unlock(); |
37d81828 PM |
4434 | } |
4435 | ||
906010b2 PZ |
4436 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4437 | { | |
4438 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4439 | struct ring_buffer *rb; |
906010b2 PZ |
4440 | int ret = VM_FAULT_SIGBUS; |
4441 | ||
4442 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4443 | if (vmf->pgoff == 0) | |
4444 | ret = 0; | |
4445 | return ret; | |
4446 | } | |
4447 | ||
4448 | rcu_read_lock(); | |
76369139 FW |
4449 | rb = rcu_dereference(event->rb); |
4450 | if (!rb) | |
906010b2 PZ |
4451 | goto unlock; |
4452 | ||
4453 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4454 | goto unlock; | |
4455 | ||
76369139 | 4456 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4457 | if (!vmf->page) |
4458 | goto unlock; | |
4459 | ||
4460 | get_page(vmf->page); | |
4461 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4462 | vmf->page->index = vmf->pgoff; | |
4463 | ||
4464 | ret = 0; | |
4465 | unlock: | |
4466 | rcu_read_unlock(); | |
4467 | ||
4468 | return ret; | |
4469 | } | |
4470 | ||
10c6db11 PZ |
4471 | static void ring_buffer_attach(struct perf_event *event, |
4472 | struct ring_buffer *rb) | |
4473 | { | |
b69cf536 | 4474 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4475 | unsigned long flags; |
4476 | ||
b69cf536 PZ |
4477 | if (event->rb) { |
4478 | /* | |
4479 | * Should be impossible, we set this when removing | |
4480 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4481 | */ | |
4482 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4483 | |
b69cf536 | 4484 | old_rb = event->rb; |
b69cf536 PZ |
4485 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4486 | list_del_rcu(&event->rb_entry); | |
4487 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4488 | |
2f993cf0 ON |
4489 | event->rcu_batches = get_state_synchronize_rcu(); |
4490 | event->rcu_pending = 1; | |
b69cf536 | 4491 | } |
10c6db11 | 4492 | |
b69cf536 | 4493 | if (rb) { |
2f993cf0 ON |
4494 | if (event->rcu_pending) { |
4495 | cond_synchronize_rcu(event->rcu_batches); | |
4496 | event->rcu_pending = 0; | |
4497 | } | |
4498 | ||
b69cf536 PZ |
4499 | spin_lock_irqsave(&rb->event_lock, flags); |
4500 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4501 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4502 | } | |
4503 | ||
4504 | rcu_assign_pointer(event->rb, rb); | |
4505 | ||
4506 | if (old_rb) { | |
4507 | ring_buffer_put(old_rb); | |
4508 | /* | |
4509 | * Since we detached before setting the new rb, so that we | |
4510 | * could attach the new rb, we could have missed a wakeup. | |
4511 | * Provide it now. | |
4512 | */ | |
4513 | wake_up_all(&event->waitq); | |
4514 | } | |
10c6db11 PZ |
4515 | } |
4516 | ||
4517 | static void ring_buffer_wakeup(struct perf_event *event) | |
4518 | { | |
4519 | struct ring_buffer *rb; | |
4520 | ||
4521 | rcu_read_lock(); | |
4522 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4523 | if (rb) { |
4524 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4525 | wake_up_all(&event->waitq); | |
4526 | } | |
10c6db11 PZ |
4527 | rcu_read_unlock(); |
4528 | } | |
4529 | ||
fdc26706 | 4530 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4531 | { |
76369139 | 4532 | struct ring_buffer *rb; |
7b732a75 | 4533 | |
ac9721f3 | 4534 | rcu_read_lock(); |
76369139 FW |
4535 | rb = rcu_dereference(event->rb); |
4536 | if (rb) { | |
4537 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4538 | rb = NULL; | |
ac9721f3 PZ |
4539 | } |
4540 | rcu_read_unlock(); | |
4541 | ||
76369139 | 4542 | return rb; |
ac9721f3 PZ |
4543 | } |
4544 | ||
fdc26706 | 4545 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4546 | { |
76369139 | 4547 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4548 | return; |
7b732a75 | 4549 | |
9bb5d40c | 4550 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4551 | |
76369139 | 4552 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4553 | } |
4554 | ||
4555 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4556 | { | |
cdd6c482 | 4557 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4558 | |
cdd6c482 | 4559 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4560 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4561 | |
45bfb2e5 PZ |
4562 | if (vma->vm_pgoff) |
4563 | atomic_inc(&event->rb->aux_mmap_count); | |
4564 | ||
1e0fb9ec AL |
4565 | if (event->pmu->event_mapped) |
4566 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4567 | } |
4568 | ||
9bb5d40c PZ |
4569 | /* |
4570 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4571 | * event, or through other events by use of perf_event_set_output(). | |
4572 | * | |
4573 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4574 | * the buffer here, where we still have a VM context. This means we need | |
4575 | * to detach all events redirecting to us. | |
4576 | */ | |
7b732a75 PZ |
4577 | static void perf_mmap_close(struct vm_area_struct *vma) |
4578 | { | |
cdd6c482 | 4579 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4580 | |
b69cf536 | 4581 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4582 | struct user_struct *mmap_user = rb->mmap_user; |
4583 | int mmap_locked = rb->mmap_locked; | |
4584 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4585 | |
1e0fb9ec AL |
4586 | if (event->pmu->event_unmapped) |
4587 | event->pmu->event_unmapped(event); | |
4588 | ||
45bfb2e5 PZ |
4589 | /* |
4590 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4591 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4592 | * serialize with perf_mmap here. | |
4593 | */ | |
4594 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4595 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4596 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4597 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4598 | ||
4599 | rb_free_aux(rb); | |
4600 | mutex_unlock(&event->mmap_mutex); | |
4601 | } | |
4602 | ||
9bb5d40c PZ |
4603 | atomic_dec(&rb->mmap_count); |
4604 | ||
4605 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4606 | goto out_put; |
9bb5d40c | 4607 | |
b69cf536 | 4608 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4609 | mutex_unlock(&event->mmap_mutex); |
4610 | ||
4611 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4612 | if (atomic_read(&rb->mmap_count)) |
4613 | goto out_put; | |
ac9721f3 | 4614 | |
9bb5d40c PZ |
4615 | /* |
4616 | * No other mmap()s, detach from all other events that might redirect | |
4617 | * into the now unreachable buffer. Somewhat complicated by the | |
4618 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4619 | */ | |
4620 | again: | |
4621 | rcu_read_lock(); | |
4622 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4623 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4624 | /* | |
4625 | * This event is en-route to free_event() which will | |
4626 | * detach it and remove it from the list. | |
4627 | */ | |
4628 | continue; | |
4629 | } | |
4630 | rcu_read_unlock(); | |
789f90fc | 4631 | |
9bb5d40c PZ |
4632 | mutex_lock(&event->mmap_mutex); |
4633 | /* | |
4634 | * Check we didn't race with perf_event_set_output() which can | |
4635 | * swizzle the rb from under us while we were waiting to | |
4636 | * acquire mmap_mutex. | |
4637 | * | |
4638 | * If we find a different rb; ignore this event, a next | |
4639 | * iteration will no longer find it on the list. We have to | |
4640 | * still restart the iteration to make sure we're not now | |
4641 | * iterating the wrong list. | |
4642 | */ | |
b69cf536 PZ |
4643 | if (event->rb == rb) |
4644 | ring_buffer_attach(event, NULL); | |
4645 | ||
cdd6c482 | 4646 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4647 | put_event(event); |
ac9721f3 | 4648 | |
9bb5d40c PZ |
4649 | /* |
4650 | * Restart the iteration; either we're on the wrong list or | |
4651 | * destroyed its integrity by doing a deletion. | |
4652 | */ | |
4653 | goto again; | |
7b732a75 | 4654 | } |
9bb5d40c PZ |
4655 | rcu_read_unlock(); |
4656 | ||
4657 | /* | |
4658 | * It could be there's still a few 0-ref events on the list; they'll | |
4659 | * get cleaned up by free_event() -- they'll also still have their | |
4660 | * ref on the rb and will free it whenever they are done with it. | |
4661 | * | |
4662 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4663 | * undo the VM accounting. | |
4664 | */ | |
4665 | ||
4666 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4667 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4668 | free_uid(mmap_user); | |
4669 | ||
b69cf536 | 4670 | out_put: |
9bb5d40c | 4671 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4672 | } |
4673 | ||
f0f37e2f | 4674 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4675 | .open = perf_mmap_open, |
45bfb2e5 | 4676 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4677 | .fault = perf_mmap_fault, |
4678 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4679 | }; |
4680 | ||
4681 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4682 | { | |
cdd6c482 | 4683 | struct perf_event *event = file->private_data; |
22a4f650 | 4684 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4685 | struct user_struct *user = current_user(); |
22a4f650 | 4686 | unsigned long locked, lock_limit; |
45bfb2e5 | 4687 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4688 | unsigned long vma_size; |
4689 | unsigned long nr_pages; | |
45bfb2e5 | 4690 | long user_extra = 0, extra = 0; |
d57e34fd | 4691 | int ret = 0, flags = 0; |
37d81828 | 4692 | |
c7920614 PZ |
4693 | /* |
4694 | * Don't allow mmap() of inherited per-task counters. This would | |
4695 | * create a performance issue due to all children writing to the | |
76369139 | 4696 | * same rb. |
c7920614 PZ |
4697 | */ |
4698 | if (event->cpu == -1 && event->attr.inherit) | |
4699 | return -EINVAL; | |
4700 | ||
43a21ea8 | 4701 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4702 | return -EINVAL; |
7b732a75 PZ |
4703 | |
4704 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4705 | |
4706 | if (vma->vm_pgoff == 0) { | |
4707 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4708 | } else { | |
4709 | /* | |
4710 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4711 | * mapped, all subsequent mappings should have the same size | |
4712 | * and offset. Must be above the normal perf buffer. | |
4713 | */ | |
4714 | u64 aux_offset, aux_size; | |
4715 | ||
4716 | if (!event->rb) | |
4717 | return -EINVAL; | |
4718 | ||
4719 | nr_pages = vma_size / PAGE_SIZE; | |
4720 | ||
4721 | mutex_lock(&event->mmap_mutex); | |
4722 | ret = -EINVAL; | |
4723 | ||
4724 | rb = event->rb; | |
4725 | if (!rb) | |
4726 | goto aux_unlock; | |
4727 | ||
4728 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4729 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4730 | ||
4731 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4732 | goto aux_unlock; | |
4733 | ||
4734 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4735 | goto aux_unlock; | |
4736 | ||
4737 | /* already mapped with a different offset */ | |
4738 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4739 | goto aux_unlock; | |
4740 | ||
4741 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4742 | goto aux_unlock; | |
4743 | ||
4744 | /* already mapped with a different size */ | |
4745 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4746 | goto aux_unlock; | |
4747 | ||
4748 | if (!is_power_of_2(nr_pages)) | |
4749 | goto aux_unlock; | |
4750 | ||
4751 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4752 | goto aux_unlock; | |
4753 | ||
4754 | if (rb_has_aux(rb)) { | |
4755 | atomic_inc(&rb->aux_mmap_count); | |
4756 | ret = 0; | |
4757 | goto unlock; | |
4758 | } | |
4759 | ||
4760 | atomic_set(&rb->aux_mmap_count, 1); | |
4761 | user_extra = nr_pages; | |
4762 | ||
4763 | goto accounting; | |
4764 | } | |
7b732a75 | 4765 | |
7730d865 | 4766 | /* |
76369139 | 4767 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4768 | * can do bitmasks instead of modulo. |
4769 | */ | |
2ed11312 | 4770 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4771 | return -EINVAL; |
4772 | ||
7b732a75 | 4773 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4774 | return -EINVAL; |
4775 | ||
cdd6c482 | 4776 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4777 | again: |
cdd6c482 | 4778 | mutex_lock(&event->mmap_mutex); |
76369139 | 4779 | if (event->rb) { |
9bb5d40c | 4780 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4781 | ret = -EINVAL; |
9bb5d40c PZ |
4782 | goto unlock; |
4783 | } | |
4784 | ||
4785 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4786 | /* | |
4787 | * Raced against perf_mmap_close() through | |
4788 | * perf_event_set_output(). Try again, hope for better | |
4789 | * luck. | |
4790 | */ | |
4791 | mutex_unlock(&event->mmap_mutex); | |
4792 | goto again; | |
4793 | } | |
4794 | ||
ebb3c4c4 PZ |
4795 | goto unlock; |
4796 | } | |
4797 | ||
789f90fc | 4798 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4799 | |
4800 | accounting: | |
cdd6c482 | 4801 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4802 | |
4803 | /* | |
4804 | * Increase the limit linearly with more CPUs: | |
4805 | */ | |
4806 | user_lock_limit *= num_online_cpus(); | |
4807 | ||
789f90fc | 4808 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4809 | |
789f90fc PZ |
4810 | if (user_locked > user_lock_limit) |
4811 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4812 | |
78d7d407 | 4813 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4814 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4815 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4816 | |
459ec28a IM |
4817 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4818 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4819 | ret = -EPERM; |
4820 | goto unlock; | |
4821 | } | |
7b732a75 | 4822 | |
45bfb2e5 | 4823 | WARN_ON(!rb && event->rb); |
906010b2 | 4824 | |
d57e34fd | 4825 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4826 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4827 | |
76369139 | 4828 | if (!rb) { |
45bfb2e5 PZ |
4829 | rb = rb_alloc(nr_pages, |
4830 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4831 | event->cpu, flags); | |
26cb63ad | 4832 | |
45bfb2e5 PZ |
4833 | if (!rb) { |
4834 | ret = -ENOMEM; | |
4835 | goto unlock; | |
4836 | } | |
43a21ea8 | 4837 | |
45bfb2e5 PZ |
4838 | atomic_set(&rb->mmap_count, 1); |
4839 | rb->mmap_user = get_current_user(); | |
4840 | rb->mmap_locked = extra; | |
26cb63ad | 4841 | |
45bfb2e5 | 4842 | ring_buffer_attach(event, rb); |
ac9721f3 | 4843 | |
45bfb2e5 PZ |
4844 | perf_event_init_userpage(event); |
4845 | perf_event_update_userpage(event); | |
4846 | } else { | |
1a594131 AS |
4847 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4848 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4849 | if (!ret) |
4850 | rb->aux_mmap_locked = extra; | |
4851 | } | |
9a0f05cb | 4852 | |
ebb3c4c4 | 4853 | unlock: |
45bfb2e5 PZ |
4854 | if (!ret) { |
4855 | atomic_long_add(user_extra, &user->locked_vm); | |
4856 | vma->vm_mm->pinned_vm += extra; | |
4857 | ||
ac9721f3 | 4858 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4859 | } else if (rb) { |
4860 | atomic_dec(&rb->mmap_count); | |
4861 | } | |
4862 | aux_unlock: | |
cdd6c482 | 4863 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4864 | |
9bb5d40c PZ |
4865 | /* |
4866 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4867 | * vma. | |
4868 | */ | |
26cb63ad | 4869 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4870 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4871 | |
1e0fb9ec AL |
4872 | if (event->pmu->event_mapped) |
4873 | event->pmu->event_mapped(event); | |
4874 | ||
7b732a75 | 4875 | return ret; |
37d81828 PM |
4876 | } |
4877 | ||
3c446b3d PZ |
4878 | static int perf_fasync(int fd, struct file *filp, int on) |
4879 | { | |
496ad9aa | 4880 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4881 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4882 | int retval; |
4883 | ||
4884 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4885 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4886 | mutex_unlock(&inode->i_mutex); |
4887 | ||
4888 | if (retval < 0) | |
4889 | return retval; | |
4890 | ||
4891 | return 0; | |
4892 | } | |
4893 | ||
0793a61d | 4894 | static const struct file_operations perf_fops = { |
3326c1ce | 4895 | .llseek = no_llseek, |
0793a61d TG |
4896 | .release = perf_release, |
4897 | .read = perf_read, | |
4898 | .poll = perf_poll, | |
d859e29f | 4899 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4900 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4901 | .mmap = perf_mmap, |
3c446b3d | 4902 | .fasync = perf_fasync, |
0793a61d TG |
4903 | }; |
4904 | ||
925d519a | 4905 | /* |
cdd6c482 | 4906 | * Perf event wakeup |
925d519a PZ |
4907 | * |
4908 | * If there's data, ensure we set the poll() state and publish everything | |
4909 | * to user-space before waking everybody up. | |
4910 | */ | |
4911 | ||
fed66e2c PZ |
4912 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4913 | { | |
4914 | /* only the parent has fasync state */ | |
4915 | if (event->parent) | |
4916 | event = event->parent; | |
4917 | return &event->fasync; | |
4918 | } | |
4919 | ||
cdd6c482 | 4920 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4921 | { |
10c6db11 | 4922 | ring_buffer_wakeup(event); |
4c9e2542 | 4923 | |
cdd6c482 | 4924 | if (event->pending_kill) { |
fed66e2c | 4925 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4926 | event->pending_kill = 0; |
4c9e2542 | 4927 | } |
925d519a PZ |
4928 | } |
4929 | ||
e360adbe | 4930 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4931 | { |
cdd6c482 IM |
4932 | struct perf_event *event = container_of(entry, |
4933 | struct perf_event, pending); | |
d525211f PZ |
4934 | int rctx; |
4935 | ||
4936 | rctx = perf_swevent_get_recursion_context(); | |
4937 | /* | |
4938 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4939 | * and we won't recurse 'further'. | |
4940 | */ | |
79f14641 | 4941 | |
cdd6c482 IM |
4942 | if (event->pending_disable) { |
4943 | event->pending_disable = 0; | |
4944 | __perf_event_disable(event); | |
79f14641 PZ |
4945 | } |
4946 | ||
cdd6c482 IM |
4947 | if (event->pending_wakeup) { |
4948 | event->pending_wakeup = 0; | |
4949 | perf_event_wakeup(event); | |
79f14641 | 4950 | } |
d525211f PZ |
4951 | |
4952 | if (rctx >= 0) | |
4953 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4954 | } |
4955 | ||
39447b38 ZY |
4956 | /* |
4957 | * We assume there is only KVM supporting the callbacks. | |
4958 | * Later on, we might change it to a list if there is | |
4959 | * another virtualization implementation supporting the callbacks. | |
4960 | */ | |
4961 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4962 | ||
4963 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4964 | { | |
4965 | perf_guest_cbs = cbs; | |
4966 | return 0; | |
4967 | } | |
4968 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4969 | ||
4970 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4971 | { | |
4972 | perf_guest_cbs = NULL; | |
4973 | return 0; | |
4974 | } | |
4975 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4976 | ||
4018994f JO |
4977 | static void |
4978 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4979 | struct pt_regs *regs, u64 mask) | |
4980 | { | |
4981 | int bit; | |
4982 | ||
4983 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4984 | sizeof(mask) * BITS_PER_BYTE) { | |
4985 | u64 val; | |
4986 | ||
4987 | val = perf_reg_value(regs, bit); | |
4988 | perf_output_put(handle, val); | |
4989 | } | |
4990 | } | |
4991 | ||
60e2364e | 4992 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4993 | struct pt_regs *regs, |
4994 | struct pt_regs *regs_user_copy) | |
4018994f | 4995 | { |
88a7c26a AL |
4996 | if (user_mode(regs)) { |
4997 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4998 | regs_user->regs = regs; |
88a7c26a AL |
4999 | } else if (current->mm) { |
5000 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5001 | } else { |
5002 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5003 | regs_user->regs = NULL; | |
4018994f JO |
5004 | } |
5005 | } | |
5006 | ||
60e2364e SE |
5007 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5008 | struct pt_regs *regs) | |
5009 | { | |
5010 | regs_intr->regs = regs; | |
5011 | regs_intr->abi = perf_reg_abi(current); | |
5012 | } | |
5013 | ||
5014 | ||
c5ebcedb JO |
5015 | /* |
5016 | * Get remaining task size from user stack pointer. | |
5017 | * | |
5018 | * It'd be better to take stack vma map and limit this more | |
5019 | * precisly, but there's no way to get it safely under interrupt, | |
5020 | * so using TASK_SIZE as limit. | |
5021 | */ | |
5022 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5023 | { | |
5024 | unsigned long addr = perf_user_stack_pointer(regs); | |
5025 | ||
5026 | if (!addr || addr >= TASK_SIZE) | |
5027 | return 0; | |
5028 | ||
5029 | return TASK_SIZE - addr; | |
5030 | } | |
5031 | ||
5032 | static u16 | |
5033 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5034 | struct pt_regs *regs) | |
5035 | { | |
5036 | u64 task_size; | |
5037 | ||
5038 | /* No regs, no stack pointer, no dump. */ | |
5039 | if (!regs) | |
5040 | return 0; | |
5041 | ||
5042 | /* | |
5043 | * Check if we fit in with the requested stack size into the: | |
5044 | * - TASK_SIZE | |
5045 | * If we don't, we limit the size to the TASK_SIZE. | |
5046 | * | |
5047 | * - remaining sample size | |
5048 | * If we don't, we customize the stack size to | |
5049 | * fit in to the remaining sample size. | |
5050 | */ | |
5051 | ||
5052 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5053 | stack_size = min(stack_size, (u16) task_size); | |
5054 | ||
5055 | /* Current header size plus static size and dynamic size. */ | |
5056 | header_size += 2 * sizeof(u64); | |
5057 | ||
5058 | /* Do we fit in with the current stack dump size? */ | |
5059 | if ((u16) (header_size + stack_size) < header_size) { | |
5060 | /* | |
5061 | * If we overflow the maximum size for the sample, | |
5062 | * we customize the stack dump size to fit in. | |
5063 | */ | |
5064 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5065 | stack_size = round_up(stack_size, sizeof(u64)); | |
5066 | } | |
5067 | ||
5068 | return stack_size; | |
5069 | } | |
5070 | ||
5071 | static void | |
5072 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5073 | struct pt_regs *regs) | |
5074 | { | |
5075 | /* Case of a kernel thread, nothing to dump */ | |
5076 | if (!regs) { | |
5077 | u64 size = 0; | |
5078 | perf_output_put(handle, size); | |
5079 | } else { | |
5080 | unsigned long sp; | |
5081 | unsigned int rem; | |
5082 | u64 dyn_size; | |
5083 | ||
5084 | /* | |
5085 | * We dump: | |
5086 | * static size | |
5087 | * - the size requested by user or the best one we can fit | |
5088 | * in to the sample max size | |
5089 | * data | |
5090 | * - user stack dump data | |
5091 | * dynamic size | |
5092 | * - the actual dumped size | |
5093 | */ | |
5094 | ||
5095 | /* Static size. */ | |
5096 | perf_output_put(handle, dump_size); | |
5097 | ||
5098 | /* Data. */ | |
5099 | sp = perf_user_stack_pointer(regs); | |
5100 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5101 | dyn_size = dump_size - rem; | |
5102 | ||
5103 | perf_output_skip(handle, rem); | |
5104 | ||
5105 | /* Dynamic size. */ | |
5106 | perf_output_put(handle, dyn_size); | |
5107 | } | |
5108 | } | |
5109 | ||
c980d109 ACM |
5110 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5111 | struct perf_sample_data *data, | |
5112 | struct perf_event *event) | |
6844c09d ACM |
5113 | { |
5114 | u64 sample_type = event->attr.sample_type; | |
5115 | ||
5116 | data->type = sample_type; | |
5117 | header->size += event->id_header_size; | |
5118 | ||
5119 | if (sample_type & PERF_SAMPLE_TID) { | |
5120 | /* namespace issues */ | |
5121 | data->tid_entry.pid = perf_event_pid(event, current); | |
5122 | data->tid_entry.tid = perf_event_tid(event, current); | |
5123 | } | |
5124 | ||
5125 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5126 | data->time = perf_event_clock(event); |
6844c09d | 5127 | |
ff3d527c | 5128 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5129 | data->id = primary_event_id(event); |
5130 | ||
5131 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5132 | data->stream_id = event->id; | |
5133 | ||
5134 | if (sample_type & PERF_SAMPLE_CPU) { | |
5135 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5136 | data->cpu_entry.reserved = 0; | |
5137 | } | |
5138 | } | |
5139 | ||
76369139 FW |
5140 | void perf_event_header__init_id(struct perf_event_header *header, |
5141 | struct perf_sample_data *data, | |
5142 | struct perf_event *event) | |
c980d109 ACM |
5143 | { |
5144 | if (event->attr.sample_id_all) | |
5145 | __perf_event_header__init_id(header, data, event); | |
5146 | } | |
5147 | ||
5148 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5149 | struct perf_sample_data *data) | |
5150 | { | |
5151 | u64 sample_type = data->type; | |
5152 | ||
5153 | if (sample_type & PERF_SAMPLE_TID) | |
5154 | perf_output_put(handle, data->tid_entry); | |
5155 | ||
5156 | if (sample_type & PERF_SAMPLE_TIME) | |
5157 | perf_output_put(handle, data->time); | |
5158 | ||
5159 | if (sample_type & PERF_SAMPLE_ID) | |
5160 | perf_output_put(handle, data->id); | |
5161 | ||
5162 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5163 | perf_output_put(handle, data->stream_id); | |
5164 | ||
5165 | if (sample_type & PERF_SAMPLE_CPU) | |
5166 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5167 | |
5168 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5169 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5170 | } |
5171 | ||
76369139 FW |
5172 | void perf_event__output_id_sample(struct perf_event *event, |
5173 | struct perf_output_handle *handle, | |
5174 | struct perf_sample_data *sample) | |
c980d109 ACM |
5175 | { |
5176 | if (event->attr.sample_id_all) | |
5177 | __perf_event__output_id_sample(handle, sample); | |
5178 | } | |
5179 | ||
3dab77fb | 5180 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5181 | struct perf_event *event, |
5182 | u64 enabled, u64 running) | |
3dab77fb | 5183 | { |
cdd6c482 | 5184 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5185 | u64 values[4]; |
5186 | int n = 0; | |
5187 | ||
b5e58793 | 5188 | values[n++] = perf_event_count(event); |
3dab77fb | 5189 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5190 | values[n++] = enabled + |
cdd6c482 | 5191 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5192 | } |
5193 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5194 | values[n++] = running + |
cdd6c482 | 5195 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5196 | } |
5197 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5198 | values[n++] = primary_event_id(event); |
3dab77fb | 5199 | |
76369139 | 5200 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5201 | } |
5202 | ||
5203 | /* | |
cdd6c482 | 5204 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5205 | */ |
5206 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5207 | struct perf_event *event, |
5208 | u64 enabled, u64 running) | |
3dab77fb | 5209 | { |
cdd6c482 IM |
5210 | struct perf_event *leader = event->group_leader, *sub; |
5211 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5212 | u64 values[5]; |
5213 | int n = 0; | |
5214 | ||
5215 | values[n++] = 1 + leader->nr_siblings; | |
5216 | ||
5217 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5218 | values[n++] = enabled; |
3dab77fb PZ |
5219 | |
5220 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5221 | values[n++] = running; |
3dab77fb | 5222 | |
cdd6c482 | 5223 | if (leader != event) |
3dab77fb PZ |
5224 | leader->pmu->read(leader); |
5225 | ||
b5e58793 | 5226 | values[n++] = perf_event_count(leader); |
3dab77fb | 5227 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5228 | values[n++] = primary_event_id(leader); |
3dab77fb | 5229 | |
76369139 | 5230 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5231 | |
65abc865 | 5232 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5233 | n = 0; |
5234 | ||
6f5ab001 JO |
5235 | if ((sub != event) && |
5236 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5237 | sub->pmu->read(sub); |
5238 | ||
b5e58793 | 5239 | values[n++] = perf_event_count(sub); |
3dab77fb | 5240 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5241 | values[n++] = primary_event_id(sub); |
3dab77fb | 5242 | |
76369139 | 5243 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5244 | } |
5245 | } | |
5246 | ||
eed01528 SE |
5247 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5248 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5249 | ||
3dab77fb | 5250 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5251 | struct perf_event *event) |
3dab77fb | 5252 | { |
e3f3541c | 5253 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5254 | u64 read_format = event->attr.read_format; |
5255 | ||
5256 | /* | |
5257 | * compute total_time_enabled, total_time_running | |
5258 | * based on snapshot values taken when the event | |
5259 | * was last scheduled in. | |
5260 | * | |
5261 | * we cannot simply called update_context_time() | |
5262 | * because of locking issue as we are called in | |
5263 | * NMI context | |
5264 | */ | |
c4794295 | 5265 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5266 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5267 | |
cdd6c482 | 5268 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5269 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5270 | else |
eed01528 | 5271 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5272 | } |
5273 | ||
5622f295 MM |
5274 | void perf_output_sample(struct perf_output_handle *handle, |
5275 | struct perf_event_header *header, | |
5276 | struct perf_sample_data *data, | |
cdd6c482 | 5277 | struct perf_event *event) |
5622f295 MM |
5278 | { |
5279 | u64 sample_type = data->type; | |
5280 | ||
5281 | perf_output_put(handle, *header); | |
5282 | ||
ff3d527c AH |
5283 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5284 | perf_output_put(handle, data->id); | |
5285 | ||
5622f295 MM |
5286 | if (sample_type & PERF_SAMPLE_IP) |
5287 | perf_output_put(handle, data->ip); | |
5288 | ||
5289 | if (sample_type & PERF_SAMPLE_TID) | |
5290 | perf_output_put(handle, data->tid_entry); | |
5291 | ||
5292 | if (sample_type & PERF_SAMPLE_TIME) | |
5293 | perf_output_put(handle, data->time); | |
5294 | ||
5295 | if (sample_type & PERF_SAMPLE_ADDR) | |
5296 | perf_output_put(handle, data->addr); | |
5297 | ||
5298 | if (sample_type & PERF_SAMPLE_ID) | |
5299 | perf_output_put(handle, data->id); | |
5300 | ||
5301 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5302 | perf_output_put(handle, data->stream_id); | |
5303 | ||
5304 | if (sample_type & PERF_SAMPLE_CPU) | |
5305 | perf_output_put(handle, data->cpu_entry); | |
5306 | ||
5307 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5308 | perf_output_put(handle, data->period); | |
5309 | ||
5310 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5311 | perf_output_read(handle, event); |
5622f295 MM |
5312 | |
5313 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5314 | if (data->callchain) { | |
5315 | int size = 1; | |
5316 | ||
5317 | if (data->callchain) | |
5318 | size += data->callchain->nr; | |
5319 | ||
5320 | size *= sizeof(u64); | |
5321 | ||
76369139 | 5322 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5323 | } else { |
5324 | u64 nr = 0; | |
5325 | perf_output_put(handle, nr); | |
5326 | } | |
5327 | } | |
5328 | ||
5329 | if (sample_type & PERF_SAMPLE_RAW) { | |
5330 | if (data->raw) { | |
fa128e6a AS |
5331 | u32 raw_size = data->raw->size; |
5332 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5333 | sizeof(u64)) - sizeof(u32); | |
5334 | u64 zero = 0; | |
5335 | ||
5336 | perf_output_put(handle, real_size); | |
5337 | __output_copy(handle, data->raw->data, raw_size); | |
5338 | if (real_size - raw_size) | |
5339 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5340 | } else { |
5341 | struct { | |
5342 | u32 size; | |
5343 | u32 data; | |
5344 | } raw = { | |
5345 | .size = sizeof(u32), | |
5346 | .data = 0, | |
5347 | }; | |
5348 | perf_output_put(handle, raw); | |
5349 | } | |
5350 | } | |
a7ac67ea | 5351 | |
bce38cd5 SE |
5352 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5353 | if (data->br_stack) { | |
5354 | size_t size; | |
5355 | ||
5356 | size = data->br_stack->nr | |
5357 | * sizeof(struct perf_branch_entry); | |
5358 | ||
5359 | perf_output_put(handle, data->br_stack->nr); | |
5360 | perf_output_copy(handle, data->br_stack->entries, size); | |
5361 | } else { | |
5362 | /* | |
5363 | * we always store at least the value of nr | |
5364 | */ | |
5365 | u64 nr = 0; | |
5366 | perf_output_put(handle, nr); | |
5367 | } | |
5368 | } | |
4018994f JO |
5369 | |
5370 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5371 | u64 abi = data->regs_user.abi; | |
5372 | ||
5373 | /* | |
5374 | * If there are no regs to dump, notice it through | |
5375 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5376 | */ | |
5377 | perf_output_put(handle, abi); | |
5378 | ||
5379 | if (abi) { | |
5380 | u64 mask = event->attr.sample_regs_user; | |
5381 | perf_output_sample_regs(handle, | |
5382 | data->regs_user.regs, | |
5383 | mask); | |
5384 | } | |
5385 | } | |
c5ebcedb | 5386 | |
a5cdd40c | 5387 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5388 | perf_output_sample_ustack(handle, |
5389 | data->stack_user_size, | |
5390 | data->regs_user.regs); | |
a5cdd40c | 5391 | } |
c3feedf2 AK |
5392 | |
5393 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5394 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5395 | |
5396 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5397 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5398 | |
fdfbbd07 AK |
5399 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5400 | perf_output_put(handle, data->txn); | |
5401 | ||
60e2364e SE |
5402 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5403 | u64 abi = data->regs_intr.abi; | |
5404 | /* | |
5405 | * If there are no regs to dump, notice it through | |
5406 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5407 | */ | |
5408 | perf_output_put(handle, abi); | |
5409 | ||
5410 | if (abi) { | |
5411 | u64 mask = event->attr.sample_regs_intr; | |
5412 | ||
5413 | perf_output_sample_regs(handle, | |
5414 | data->regs_intr.regs, | |
5415 | mask); | |
5416 | } | |
5417 | } | |
5418 | ||
a5cdd40c PZ |
5419 | if (!event->attr.watermark) { |
5420 | int wakeup_events = event->attr.wakeup_events; | |
5421 | ||
5422 | if (wakeup_events) { | |
5423 | struct ring_buffer *rb = handle->rb; | |
5424 | int events = local_inc_return(&rb->events); | |
5425 | ||
5426 | if (events >= wakeup_events) { | |
5427 | local_sub(wakeup_events, &rb->events); | |
5428 | local_inc(&rb->wakeup); | |
5429 | } | |
5430 | } | |
5431 | } | |
5622f295 MM |
5432 | } |
5433 | ||
5434 | void perf_prepare_sample(struct perf_event_header *header, | |
5435 | struct perf_sample_data *data, | |
cdd6c482 | 5436 | struct perf_event *event, |
5622f295 | 5437 | struct pt_regs *regs) |
7b732a75 | 5438 | { |
cdd6c482 | 5439 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5440 | |
cdd6c482 | 5441 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5442 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5443 | |
5444 | header->misc = 0; | |
5445 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5446 | |
c980d109 | 5447 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5448 | |
c320c7b7 | 5449 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5450 | data->ip = perf_instruction_pointer(regs); |
5451 | ||
b23f3325 | 5452 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5453 | int size = 1; |
394ee076 | 5454 | |
e6dab5ff | 5455 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5456 | |
5457 | if (data->callchain) | |
5458 | size += data->callchain->nr; | |
5459 | ||
5460 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5461 | } |
5462 | ||
3a43ce68 | 5463 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5464 | int size = sizeof(u32); |
5465 | ||
5466 | if (data->raw) | |
5467 | size += data->raw->size; | |
5468 | else | |
5469 | size += sizeof(u32); | |
5470 | ||
fa128e6a | 5471 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5472 | } |
bce38cd5 SE |
5473 | |
5474 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5475 | int size = sizeof(u64); /* nr */ | |
5476 | if (data->br_stack) { | |
5477 | size += data->br_stack->nr | |
5478 | * sizeof(struct perf_branch_entry); | |
5479 | } | |
5480 | header->size += size; | |
5481 | } | |
4018994f | 5482 | |
2565711f | 5483 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5484 | perf_sample_regs_user(&data->regs_user, regs, |
5485 | &data->regs_user_copy); | |
2565711f | 5486 | |
4018994f JO |
5487 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5488 | /* regs dump ABI info */ | |
5489 | int size = sizeof(u64); | |
5490 | ||
4018994f JO |
5491 | if (data->regs_user.regs) { |
5492 | u64 mask = event->attr.sample_regs_user; | |
5493 | size += hweight64(mask) * sizeof(u64); | |
5494 | } | |
5495 | ||
5496 | header->size += size; | |
5497 | } | |
c5ebcedb JO |
5498 | |
5499 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5500 | /* | |
5501 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5502 | * processed as the last one or have additional check added | |
5503 | * in case new sample type is added, because we could eat | |
5504 | * up the rest of the sample size. | |
5505 | */ | |
c5ebcedb JO |
5506 | u16 stack_size = event->attr.sample_stack_user; |
5507 | u16 size = sizeof(u64); | |
5508 | ||
c5ebcedb | 5509 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5510 | data->regs_user.regs); |
c5ebcedb JO |
5511 | |
5512 | /* | |
5513 | * If there is something to dump, add space for the dump | |
5514 | * itself and for the field that tells the dynamic size, | |
5515 | * which is how many have been actually dumped. | |
5516 | */ | |
5517 | if (stack_size) | |
5518 | size += sizeof(u64) + stack_size; | |
5519 | ||
5520 | data->stack_user_size = stack_size; | |
5521 | header->size += size; | |
5522 | } | |
60e2364e SE |
5523 | |
5524 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5525 | /* regs dump ABI info */ | |
5526 | int size = sizeof(u64); | |
5527 | ||
5528 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5529 | ||
5530 | if (data->regs_intr.regs) { | |
5531 | u64 mask = event->attr.sample_regs_intr; | |
5532 | ||
5533 | size += hweight64(mask) * sizeof(u64); | |
5534 | } | |
5535 | ||
5536 | header->size += size; | |
5537 | } | |
5622f295 | 5538 | } |
7f453c24 | 5539 | |
21509084 YZ |
5540 | void perf_event_output(struct perf_event *event, |
5541 | struct perf_sample_data *data, | |
5542 | struct pt_regs *regs) | |
5622f295 MM |
5543 | { |
5544 | struct perf_output_handle handle; | |
5545 | struct perf_event_header header; | |
689802b2 | 5546 | |
927c7a9e FW |
5547 | /* protect the callchain buffers */ |
5548 | rcu_read_lock(); | |
5549 | ||
cdd6c482 | 5550 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5551 | |
a7ac67ea | 5552 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5553 | goto exit; |
0322cd6e | 5554 | |
cdd6c482 | 5555 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5556 | |
8a057d84 | 5557 | perf_output_end(&handle); |
927c7a9e FW |
5558 | |
5559 | exit: | |
5560 | rcu_read_unlock(); | |
0322cd6e PZ |
5561 | } |
5562 | ||
38b200d6 | 5563 | /* |
cdd6c482 | 5564 | * read event_id |
38b200d6 PZ |
5565 | */ |
5566 | ||
5567 | struct perf_read_event { | |
5568 | struct perf_event_header header; | |
5569 | ||
5570 | u32 pid; | |
5571 | u32 tid; | |
38b200d6 PZ |
5572 | }; |
5573 | ||
5574 | static void | |
cdd6c482 | 5575 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5576 | struct task_struct *task) |
5577 | { | |
5578 | struct perf_output_handle handle; | |
c980d109 | 5579 | struct perf_sample_data sample; |
dfc65094 | 5580 | struct perf_read_event read_event = { |
38b200d6 | 5581 | .header = { |
cdd6c482 | 5582 | .type = PERF_RECORD_READ, |
38b200d6 | 5583 | .misc = 0, |
c320c7b7 | 5584 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5585 | }, |
cdd6c482 IM |
5586 | .pid = perf_event_pid(event, task), |
5587 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5588 | }; |
3dab77fb | 5589 | int ret; |
38b200d6 | 5590 | |
c980d109 | 5591 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5592 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5593 | if (ret) |
5594 | return; | |
5595 | ||
dfc65094 | 5596 | perf_output_put(&handle, read_event); |
cdd6c482 | 5597 | perf_output_read(&handle, event); |
c980d109 | 5598 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5599 | |
38b200d6 PZ |
5600 | perf_output_end(&handle); |
5601 | } | |
5602 | ||
52d857a8 JO |
5603 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5604 | ||
5605 | static void | |
5606 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5607 | perf_event_aux_output_cb output, |
5608 | void *data) | |
5609 | { | |
5610 | struct perf_event *event; | |
5611 | ||
5612 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5613 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5614 | continue; | |
5615 | if (!event_filter_match(event)) | |
5616 | continue; | |
67516844 | 5617 | output(event, data); |
52d857a8 JO |
5618 | } |
5619 | } | |
5620 | ||
4e93ad60 JO |
5621 | static void |
5622 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5623 | struct perf_event_context *task_ctx) | |
5624 | { | |
5625 | rcu_read_lock(); | |
5626 | preempt_disable(); | |
5627 | perf_event_aux_ctx(task_ctx, output, data); | |
5628 | preempt_enable(); | |
5629 | rcu_read_unlock(); | |
5630 | } | |
5631 | ||
52d857a8 | 5632 | static void |
67516844 | 5633 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5634 | struct perf_event_context *task_ctx) |
5635 | { | |
5636 | struct perf_cpu_context *cpuctx; | |
5637 | struct perf_event_context *ctx; | |
5638 | struct pmu *pmu; | |
5639 | int ctxn; | |
5640 | ||
4e93ad60 JO |
5641 | /* |
5642 | * If we have task_ctx != NULL we only notify | |
5643 | * the task context itself. The task_ctx is set | |
5644 | * only for EXIT events before releasing task | |
5645 | * context. | |
5646 | */ | |
5647 | if (task_ctx) { | |
5648 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5649 | return; | |
5650 | } | |
5651 | ||
52d857a8 JO |
5652 | rcu_read_lock(); |
5653 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5654 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5655 | if (cpuctx->unique_pmu != pmu) | |
5656 | goto next; | |
67516844 | 5657 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5658 | ctxn = pmu->task_ctx_nr; |
5659 | if (ctxn < 0) | |
5660 | goto next; | |
5661 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5662 | if (ctx) | |
67516844 | 5663 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5664 | next: |
5665 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5666 | } | |
52d857a8 JO |
5667 | rcu_read_unlock(); |
5668 | } | |
5669 | ||
60313ebe | 5670 | /* |
9f498cc5 PZ |
5671 | * task tracking -- fork/exit |
5672 | * | |
13d7a241 | 5673 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5674 | */ |
5675 | ||
9f498cc5 | 5676 | struct perf_task_event { |
3a80b4a3 | 5677 | struct task_struct *task; |
cdd6c482 | 5678 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5679 | |
5680 | struct { | |
5681 | struct perf_event_header header; | |
5682 | ||
5683 | u32 pid; | |
5684 | u32 ppid; | |
9f498cc5 PZ |
5685 | u32 tid; |
5686 | u32 ptid; | |
393b2ad8 | 5687 | u64 time; |
cdd6c482 | 5688 | } event_id; |
60313ebe PZ |
5689 | }; |
5690 | ||
67516844 JO |
5691 | static int perf_event_task_match(struct perf_event *event) |
5692 | { | |
13d7a241 SE |
5693 | return event->attr.comm || event->attr.mmap || |
5694 | event->attr.mmap2 || event->attr.mmap_data || | |
5695 | event->attr.task; | |
67516844 JO |
5696 | } |
5697 | ||
cdd6c482 | 5698 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5699 | void *data) |
60313ebe | 5700 | { |
52d857a8 | 5701 | struct perf_task_event *task_event = data; |
60313ebe | 5702 | struct perf_output_handle handle; |
c980d109 | 5703 | struct perf_sample_data sample; |
9f498cc5 | 5704 | struct task_struct *task = task_event->task; |
c980d109 | 5705 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5706 | |
67516844 JO |
5707 | if (!perf_event_task_match(event)) |
5708 | return; | |
5709 | ||
c980d109 | 5710 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5711 | |
c980d109 | 5712 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5713 | task_event->event_id.header.size); |
ef60777c | 5714 | if (ret) |
c980d109 | 5715 | goto out; |
60313ebe | 5716 | |
cdd6c482 IM |
5717 | task_event->event_id.pid = perf_event_pid(event, task); |
5718 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5719 | |
cdd6c482 IM |
5720 | task_event->event_id.tid = perf_event_tid(event, task); |
5721 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5722 | |
34f43927 PZ |
5723 | task_event->event_id.time = perf_event_clock(event); |
5724 | ||
cdd6c482 | 5725 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5726 | |
c980d109 ACM |
5727 | perf_event__output_id_sample(event, &handle, &sample); |
5728 | ||
60313ebe | 5729 | perf_output_end(&handle); |
c980d109 ACM |
5730 | out: |
5731 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5732 | } |
5733 | ||
cdd6c482 IM |
5734 | static void perf_event_task(struct task_struct *task, |
5735 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5736 | int new) |
60313ebe | 5737 | { |
9f498cc5 | 5738 | struct perf_task_event task_event; |
60313ebe | 5739 | |
cdd6c482 IM |
5740 | if (!atomic_read(&nr_comm_events) && |
5741 | !atomic_read(&nr_mmap_events) && | |
5742 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5743 | return; |
5744 | ||
9f498cc5 | 5745 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5746 | .task = task, |
5747 | .task_ctx = task_ctx, | |
cdd6c482 | 5748 | .event_id = { |
60313ebe | 5749 | .header = { |
cdd6c482 | 5750 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5751 | .misc = 0, |
cdd6c482 | 5752 | .size = sizeof(task_event.event_id), |
60313ebe | 5753 | }, |
573402db PZ |
5754 | /* .pid */ |
5755 | /* .ppid */ | |
9f498cc5 PZ |
5756 | /* .tid */ |
5757 | /* .ptid */ | |
34f43927 | 5758 | /* .time */ |
60313ebe PZ |
5759 | }, |
5760 | }; | |
5761 | ||
67516844 | 5762 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5763 | &task_event, |
5764 | task_ctx); | |
9f498cc5 PZ |
5765 | } |
5766 | ||
cdd6c482 | 5767 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5768 | { |
cdd6c482 | 5769 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5770 | } |
5771 | ||
8d1b2d93 PZ |
5772 | /* |
5773 | * comm tracking | |
5774 | */ | |
5775 | ||
5776 | struct perf_comm_event { | |
22a4f650 IM |
5777 | struct task_struct *task; |
5778 | char *comm; | |
8d1b2d93 PZ |
5779 | int comm_size; |
5780 | ||
5781 | struct { | |
5782 | struct perf_event_header header; | |
5783 | ||
5784 | u32 pid; | |
5785 | u32 tid; | |
cdd6c482 | 5786 | } event_id; |
8d1b2d93 PZ |
5787 | }; |
5788 | ||
67516844 JO |
5789 | static int perf_event_comm_match(struct perf_event *event) |
5790 | { | |
5791 | return event->attr.comm; | |
5792 | } | |
5793 | ||
cdd6c482 | 5794 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5795 | void *data) |
8d1b2d93 | 5796 | { |
52d857a8 | 5797 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5798 | struct perf_output_handle handle; |
c980d109 | 5799 | struct perf_sample_data sample; |
cdd6c482 | 5800 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5801 | int ret; |
5802 | ||
67516844 JO |
5803 | if (!perf_event_comm_match(event)) |
5804 | return; | |
5805 | ||
c980d109 ACM |
5806 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5807 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5808 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5809 | |
5810 | if (ret) | |
c980d109 | 5811 | goto out; |
8d1b2d93 | 5812 | |
cdd6c482 IM |
5813 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5814 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5815 | |
cdd6c482 | 5816 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5817 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5818 | comm_event->comm_size); |
c980d109 ACM |
5819 | |
5820 | perf_event__output_id_sample(event, &handle, &sample); | |
5821 | ||
8d1b2d93 | 5822 | perf_output_end(&handle); |
c980d109 ACM |
5823 | out: |
5824 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5825 | } |
5826 | ||
cdd6c482 | 5827 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5828 | { |
413ee3b4 | 5829 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5830 | unsigned int size; |
8d1b2d93 | 5831 | |
413ee3b4 | 5832 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5833 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5834 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5835 | |
5836 | comm_event->comm = comm; | |
5837 | comm_event->comm_size = size; | |
5838 | ||
cdd6c482 | 5839 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5840 | |
67516844 | 5841 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5842 | comm_event, |
5843 | NULL); | |
8d1b2d93 PZ |
5844 | } |
5845 | ||
82b89778 | 5846 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5847 | { |
9ee318a7 PZ |
5848 | struct perf_comm_event comm_event; |
5849 | ||
cdd6c482 | 5850 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5851 | return; |
a63eaf34 | 5852 | |
9ee318a7 | 5853 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5854 | .task = task, |
573402db PZ |
5855 | /* .comm */ |
5856 | /* .comm_size */ | |
cdd6c482 | 5857 | .event_id = { |
573402db | 5858 | .header = { |
cdd6c482 | 5859 | .type = PERF_RECORD_COMM, |
82b89778 | 5860 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5861 | /* .size */ |
5862 | }, | |
5863 | /* .pid */ | |
5864 | /* .tid */ | |
8d1b2d93 PZ |
5865 | }, |
5866 | }; | |
5867 | ||
cdd6c482 | 5868 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5869 | } |
5870 | ||
0a4a9391 PZ |
5871 | /* |
5872 | * mmap tracking | |
5873 | */ | |
5874 | ||
5875 | struct perf_mmap_event { | |
089dd79d PZ |
5876 | struct vm_area_struct *vma; |
5877 | ||
5878 | const char *file_name; | |
5879 | int file_size; | |
13d7a241 SE |
5880 | int maj, min; |
5881 | u64 ino; | |
5882 | u64 ino_generation; | |
f972eb63 | 5883 | u32 prot, flags; |
0a4a9391 PZ |
5884 | |
5885 | struct { | |
5886 | struct perf_event_header header; | |
5887 | ||
5888 | u32 pid; | |
5889 | u32 tid; | |
5890 | u64 start; | |
5891 | u64 len; | |
5892 | u64 pgoff; | |
cdd6c482 | 5893 | } event_id; |
0a4a9391 PZ |
5894 | }; |
5895 | ||
67516844 JO |
5896 | static int perf_event_mmap_match(struct perf_event *event, |
5897 | void *data) | |
5898 | { | |
5899 | struct perf_mmap_event *mmap_event = data; | |
5900 | struct vm_area_struct *vma = mmap_event->vma; | |
5901 | int executable = vma->vm_flags & VM_EXEC; | |
5902 | ||
5903 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5904 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5905 | } |
5906 | ||
cdd6c482 | 5907 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5908 | void *data) |
0a4a9391 | 5909 | { |
52d857a8 | 5910 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5911 | struct perf_output_handle handle; |
c980d109 | 5912 | struct perf_sample_data sample; |
cdd6c482 | 5913 | int size = mmap_event->event_id.header.size; |
c980d109 | 5914 | int ret; |
0a4a9391 | 5915 | |
67516844 JO |
5916 | if (!perf_event_mmap_match(event, data)) |
5917 | return; | |
5918 | ||
13d7a241 SE |
5919 | if (event->attr.mmap2) { |
5920 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5921 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5922 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5923 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5924 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5925 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5926 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5927 | } |
5928 | ||
c980d109 ACM |
5929 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5930 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5931 | mmap_event->event_id.header.size); |
0a4a9391 | 5932 | if (ret) |
c980d109 | 5933 | goto out; |
0a4a9391 | 5934 | |
cdd6c482 IM |
5935 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5936 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5937 | |
cdd6c482 | 5938 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5939 | |
5940 | if (event->attr.mmap2) { | |
5941 | perf_output_put(&handle, mmap_event->maj); | |
5942 | perf_output_put(&handle, mmap_event->min); | |
5943 | perf_output_put(&handle, mmap_event->ino); | |
5944 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5945 | perf_output_put(&handle, mmap_event->prot); |
5946 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5947 | } |
5948 | ||
76369139 | 5949 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5950 | mmap_event->file_size); |
c980d109 ACM |
5951 | |
5952 | perf_event__output_id_sample(event, &handle, &sample); | |
5953 | ||
78d613eb | 5954 | perf_output_end(&handle); |
c980d109 ACM |
5955 | out: |
5956 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5957 | } |
5958 | ||
cdd6c482 | 5959 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5960 | { |
089dd79d PZ |
5961 | struct vm_area_struct *vma = mmap_event->vma; |
5962 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5963 | int maj = 0, min = 0; |
5964 | u64 ino = 0, gen = 0; | |
f972eb63 | 5965 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5966 | unsigned int size; |
5967 | char tmp[16]; | |
5968 | char *buf = NULL; | |
2c42cfbf | 5969 | char *name; |
413ee3b4 | 5970 | |
0a4a9391 | 5971 | if (file) { |
13d7a241 SE |
5972 | struct inode *inode; |
5973 | dev_t dev; | |
3ea2f2b9 | 5974 | |
2c42cfbf | 5975 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5976 | if (!buf) { |
c7e548b4 ON |
5977 | name = "//enomem"; |
5978 | goto cpy_name; | |
0a4a9391 | 5979 | } |
413ee3b4 | 5980 | /* |
3ea2f2b9 | 5981 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5982 | * need to add enough zero bytes after the string to handle |
5983 | * the 64bit alignment we do later. | |
5984 | */ | |
9bf39ab2 | 5985 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5986 | if (IS_ERR(name)) { |
c7e548b4 ON |
5987 | name = "//toolong"; |
5988 | goto cpy_name; | |
0a4a9391 | 5989 | } |
13d7a241 SE |
5990 | inode = file_inode(vma->vm_file); |
5991 | dev = inode->i_sb->s_dev; | |
5992 | ino = inode->i_ino; | |
5993 | gen = inode->i_generation; | |
5994 | maj = MAJOR(dev); | |
5995 | min = MINOR(dev); | |
f972eb63 PZ |
5996 | |
5997 | if (vma->vm_flags & VM_READ) | |
5998 | prot |= PROT_READ; | |
5999 | if (vma->vm_flags & VM_WRITE) | |
6000 | prot |= PROT_WRITE; | |
6001 | if (vma->vm_flags & VM_EXEC) | |
6002 | prot |= PROT_EXEC; | |
6003 | ||
6004 | if (vma->vm_flags & VM_MAYSHARE) | |
6005 | flags = MAP_SHARED; | |
6006 | else | |
6007 | flags = MAP_PRIVATE; | |
6008 | ||
6009 | if (vma->vm_flags & VM_DENYWRITE) | |
6010 | flags |= MAP_DENYWRITE; | |
6011 | if (vma->vm_flags & VM_MAYEXEC) | |
6012 | flags |= MAP_EXECUTABLE; | |
6013 | if (vma->vm_flags & VM_LOCKED) | |
6014 | flags |= MAP_LOCKED; | |
6015 | if (vma->vm_flags & VM_HUGETLB) | |
6016 | flags |= MAP_HUGETLB; | |
6017 | ||
c7e548b4 | 6018 | goto got_name; |
0a4a9391 | 6019 | } else { |
fbe26abe JO |
6020 | if (vma->vm_ops && vma->vm_ops->name) { |
6021 | name = (char *) vma->vm_ops->name(vma); | |
6022 | if (name) | |
6023 | goto cpy_name; | |
6024 | } | |
6025 | ||
2c42cfbf | 6026 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6027 | if (name) |
6028 | goto cpy_name; | |
089dd79d | 6029 | |
32c5fb7e | 6030 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6031 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6032 | name = "[heap]"; |
6033 | goto cpy_name; | |
32c5fb7e ON |
6034 | } |
6035 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6036 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6037 | name = "[stack]"; |
6038 | goto cpy_name; | |
089dd79d PZ |
6039 | } |
6040 | ||
c7e548b4 ON |
6041 | name = "//anon"; |
6042 | goto cpy_name; | |
0a4a9391 PZ |
6043 | } |
6044 | ||
c7e548b4 ON |
6045 | cpy_name: |
6046 | strlcpy(tmp, name, sizeof(tmp)); | |
6047 | name = tmp; | |
0a4a9391 | 6048 | got_name: |
2c42cfbf PZ |
6049 | /* |
6050 | * Since our buffer works in 8 byte units we need to align our string | |
6051 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6052 | * zero'd out to avoid leaking random bits to userspace. | |
6053 | */ | |
6054 | size = strlen(name)+1; | |
6055 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6056 | name[size++] = '\0'; | |
0a4a9391 PZ |
6057 | |
6058 | mmap_event->file_name = name; | |
6059 | mmap_event->file_size = size; | |
13d7a241 SE |
6060 | mmap_event->maj = maj; |
6061 | mmap_event->min = min; | |
6062 | mmap_event->ino = ino; | |
6063 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6064 | mmap_event->prot = prot; |
6065 | mmap_event->flags = flags; | |
0a4a9391 | 6066 | |
2fe85427 SE |
6067 | if (!(vma->vm_flags & VM_EXEC)) |
6068 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6069 | ||
cdd6c482 | 6070 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6071 | |
67516844 | 6072 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6073 | mmap_event, |
6074 | NULL); | |
665c2142 | 6075 | |
0a4a9391 PZ |
6076 | kfree(buf); |
6077 | } | |
6078 | ||
3af9e859 | 6079 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6080 | { |
9ee318a7 PZ |
6081 | struct perf_mmap_event mmap_event; |
6082 | ||
cdd6c482 | 6083 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6084 | return; |
6085 | ||
6086 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6087 | .vma = vma, |
573402db PZ |
6088 | /* .file_name */ |
6089 | /* .file_size */ | |
cdd6c482 | 6090 | .event_id = { |
573402db | 6091 | .header = { |
cdd6c482 | 6092 | .type = PERF_RECORD_MMAP, |
39447b38 | 6093 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6094 | /* .size */ |
6095 | }, | |
6096 | /* .pid */ | |
6097 | /* .tid */ | |
089dd79d PZ |
6098 | .start = vma->vm_start, |
6099 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6100 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6101 | }, |
13d7a241 SE |
6102 | /* .maj (attr_mmap2 only) */ |
6103 | /* .min (attr_mmap2 only) */ | |
6104 | /* .ino (attr_mmap2 only) */ | |
6105 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6106 | /* .prot (attr_mmap2 only) */ |
6107 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6108 | }; |
6109 | ||
cdd6c482 | 6110 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6111 | } |
6112 | ||
68db7e98 AS |
6113 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6114 | unsigned long size, u64 flags) | |
6115 | { | |
6116 | struct perf_output_handle handle; | |
6117 | struct perf_sample_data sample; | |
6118 | struct perf_aux_event { | |
6119 | struct perf_event_header header; | |
6120 | u64 offset; | |
6121 | u64 size; | |
6122 | u64 flags; | |
6123 | } rec = { | |
6124 | .header = { | |
6125 | .type = PERF_RECORD_AUX, | |
6126 | .misc = 0, | |
6127 | .size = sizeof(rec), | |
6128 | }, | |
6129 | .offset = head, | |
6130 | .size = size, | |
6131 | .flags = flags, | |
6132 | }; | |
6133 | int ret; | |
6134 | ||
6135 | perf_event_header__init_id(&rec.header, &sample, event); | |
6136 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6137 | ||
6138 | if (ret) | |
6139 | return; | |
6140 | ||
6141 | perf_output_put(&handle, rec); | |
6142 | perf_event__output_id_sample(event, &handle, &sample); | |
6143 | ||
6144 | perf_output_end(&handle); | |
6145 | } | |
6146 | ||
f38b0dbb KL |
6147 | /* |
6148 | * Lost/dropped samples logging | |
6149 | */ | |
6150 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6151 | { | |
6152 | struct perf_output_handle handle; | |
6153 | struct perf_sample_data sample; | |
6154 | int ret; | |
6155 | ||
6156 | struct { | |
6157 | struct perf_event_header header; | |
6158 | u64 lost; | |
6159 | } lost_samples_event = { | |
6160 | .header = { | |
6161 | .type = PERF_RECORD_LOST_SAMPLES, | |
6162 | .misc = 0, | |
6163 | .size = sizeof(lost_samples_event), | |
6164 | }, | |
6165 | .lost = lost, | |
6166 | }; | |
6167 | ||
6168 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6169 | ||
6170 | ret = perf_output_begin(&handle, event, | |
6171 | lost_samples_event.header.size); | |
6172 | if (ret) | |
6173 | return; | |
6174 | ||
6175 | perf_output_put(&handle, lost_samples_event); | |
6176 | perf_event__output_id_sample(event, &handle, &sample); | |
6177 | perf_output_end(&handle); | |
6178 | } | |
6179 | ||
45ac1403 AH |
6180 | /* |
6181 | * context_switch tracking | |
6182 | */ | |
6183 | ||
6184 | struct perf_switch_event { | |
6185 | struct task_struct *task; | |
6186 | struct task_struct *next_prev; | |
6187 | ||
6188 | struct { | |
6189 | struct perf_event_header header; | |
6190 | u32 next_prev_pid; | |
6191 | u32 next_prev_tid; | |
6192 | } event_id; | |
6193 | }; | |
6194 | ||
6195 | static int perf_event_switch_match(struct perf_event *event) | |
6196 | { | |
6197 | return event->attr.context_switch; | |
6198 | } | |
6199 | ||
6200 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6201 | { | |
6202 | struct perf_switch_event *se = data; | |
6203 | struct perf_output_handle handle; | |
6204 | struct perf_sample_data sample; | |
6205 | int ret; | |
6206 | ||
6207 | if (!perf_event_switch_match(event)) | |
6208 | return; | |
6209 | ||
6210 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6211 | if (event->ctx->task) { | |
6212 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6213 | se->event_id.header.size = sizeof(se->event_id.header); | |
6214 | } else { | |
6215 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6216 | se->event_id.header.size = sizeof(se->event_id); | |
6217 | se->event_id.next_prev_pid = | |
6218 | perf_event_pid(event, se->next_prev); | |
6219 | se->event_id.next_prev_tid = | |
6220 | perf_event_tid(event, se->next_prev); | |
6221 | } | |
6222 | ||
6223 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6224 | ||
6225 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6226 | if (ret) | |
6227 | return; | |
6228 | ||
6229 | if (event->ctx->task) | |
6230 | perf_output_put(&handle, se->event_id.header); | |
6231 | else | |
6232 | perf_output_put(&handle, se->event_id); | |
6233 | ||
6234 | perf_event__output_id_sample(event, &handle, &sample); | |
6235 | ||
6236 | perf_output_end(&handle); | |
6237 | } | |
6238 | ||
6239 | static void perf_event_switch(struct task_struct *task, | |
6240 | struct task_struct *next_prev, bool sched_in) | |
6241 | { | |
6242 | struct perf_switch_event switch_event; | |
6243 | ||
6244 | /* N.B. caller checks nr_switch_events != 0 */ | |
6245 | ||
6246 | switch_event = (struct perf_switch_event){ | |
6247 | .task = task, | |
6248 | .next_prev = next_prev, | |
6249 | .event_id = { | |
6250 | .header = { | |
6251 | /* .type */ | |
6252 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6253 | /* .size */ | |
6254 | }, | |
6255 | /* .next_prev_pid */ | |
6256 | /* .next_prev_tid */ | |
6257 | }, | |
6258 | }; | |
6259 | ||
6260 | perf_event_aux(perf_event_switch_output, | |
6261 | &switch_event, | |
6262 | NULL); | |
6263 | } | |
6264 | ||
a78ac325 PZ |
6265 | /* |
6266 | * IRQ throttle logging | |
6267 | */ | |
6268 | ||
cdd6c482 | 6269 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6270 | { |
6271 | struct perf_output_handle handle; | |
c980d109 | 6272 | struct perf_sample_data sample; |
a78ac325 PZ |
6273 | int ret; |
6274 | ||
6275 | struct { | |
6276 | struct perf_event_header header; | |
6277 | u64 time; | |
cca3f454 | 6278 | u64 id; |
7f453c24 | 6279 | u64 stream_id; |
a78ac325 PZ |
6280 | } throttle_event = { |
6281 | .header = { | |
cdd6c482 | 6282 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6283 | .misc = 0, |
6284 | .size = sizeof(throttle_event), | |
6285 | }, | |
34f43927 | 6286 | .time = perf_event_clock(event), |
cdd6c482 IM |
6287 | .id = primary_event_id(event), |
6288 | .stream_id = event->id, | |
a78ac325 PZ |
6289 | }; |
6290 | ||
966ee4d6 | 6291 | if (enable) |
cdd6c482 | 6292 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6293 | |
c980d109 ACM |
6294 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6295 | ||
6296 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6297 | throttle_event.header.size); |
a78ac325 PZ |
6298 | if (ret) |
6299 | return; | |
6300 | ||
6301 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6302 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6303 | perf_output_end(&handle); |
6304 | } | |
6305 | ||
ec0d7729 AS |
6306 | static void perf_log_itrace_start(struct perf_event *event) |
6307 | { | |
6308 | struct perf_output_handle handle; | |
6309 | struct perf_sample_data sample; | |
6310 | struct perf_aux_event { | |
6311 | struct perf_event_header header; | |
6312 | u32 pid; | |
6313 | u32 tid; | |
6314 | } rec; | |
6315 | int ret; | |
6316 | ||
6317 | if (event->parent) | |
6318 | event = event->parent; | |
6319 | ||
6320 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6321 | event->hw.itrace_started) | |
6322 | return; | |
6323 | ||
ec0d7729 AS |
6324 | rec.header.type = PERF_RECORD_ITRACE_START; |
6325 | rec.header.misc = 0; | |
6326 | rec.header.size = sizeof(rec); | |
6327 | rec.pid = perf_event_pid(event, current); | |
6328 | rec.tid = perf_event_tid(event, current); | |
6329 | ||
6330 | perf_event_header__init_id(&rec.header, &sample, event); | |
6331 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6332 | ||
6333 | if (ret) | |
6334 | return; | |
6335 | ||
6336 | perf_output_put(&handle, rec); | |
6337 | perf_event__output_id_sample(event, &handle, &sample); | |
6338 | ||
6339 | perf_output_end(&handle); | |
6340 | } | |
6341 | ||
f6c7d5fe | 6342 | /* |
cdd6c482 | 6343 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6344 | */ |
6345 | ||
a8b0ca17 | 6346 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6347 | int throttle, struct perf_sample_data *data, |
6348 | struct pt_regs *regs) | |
f6c7d5fe | 6349 | { |
cdd6c482 IM |
6350 | int events = atomic_read(&event->event_limit); |
6351 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6352 | u64 seq; |
79f14641 PZ |
6353 | int ret = 0; |
6354 | ||
96398826 PZ |
6355 | /* |
6356 | * Non-sampling counters might still use the PMI to fold short | |
6357 | * hardware counters, ignore those. | |
6358 | */ | |
6359 | if (unlikely(!is_sampling_event(event))) | |
6360 | return 0; | |
6361 | ||
e050e3f0 SE |
6362 | seq = __this_cpu_read(perf_throttled_seq); |
6363 | if (seq != hwc->interrupts_seq) { | |
6364 | hwc->interrupts_seq = seq; | |
6365 | hwc->interrupts = 1; | |
6366 | } else { | |
6367 | hwc->interrupts++; | |
6368 | if (unlikely(throttle | |
6369 | && hwc->interrupts >= max_samples_per_tick)) { | |
6370 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6371 | hwc->interrupts = MAX_INTERRUPTS; |
6372 | perf_log_throttle(event, 0); | |
d84153d6 | 6373 | tick_nohz_full_kick(); |
a78ac325 PZ |
6374 | ret = 1; |
6375 | } | |
e050e3f0 | 6376 | } |
60db5e09 | 6377 | |
cdd6c482 | 6378 | if (event->attr.freq) { |
def0a9b2 | 6379 | u64 now = perf_clock(); |
abd50713 | 6380 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6381 | |
abd50713 | 6382 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6383 | |
abd50713 | 6384 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6385 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6386 | } |
6387 | ||
2023b359 PZ |
6388 | /* |
6389 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6390 | * events |
2023b359 PZ |
6391 | */ |
6392 | ||
cdd6c482 IM |
6393 | event->pending_kill = POLL_IN; |
6394 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6395 | ret = 1; |
cdd6c482 | 6396 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6397 | event->pending_disable = 1; |
6398 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6399 | } |
6400 | ||
453f19ee | 6401 | if (event->overflow_handler) |
a8b0ca17 | 6402 | event->overflow_handler(event, data, regs); |
453f19ee | 6403 | else |
a8b0ca17 | 6404 | perf_event_output(event, data, regs); |
453f19ee | 6405 | |
fed66e2c | 6406 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6407 | event->pending_wakeup = 1; |
6408 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6409 | } |
6410 | ||
79f14641 | 6411 | return ret; |
f6c7d5fe PZ |
6412 | } |
6413 | ||
a8b0ca17 | 6414 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6415 | struct perf_sample_data *data, |
6416 | struct pt_regs *regs) | |
850bc73f | 6417 | { |
a8b0ca17 | 6418 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6419 | } |
6420 | ||
15dbf27c | 6421 | /* |
cdd6c482 | 6422 | * Generic software event infrastructure |
15dbf27c PZ |
6423 | */ |
6424 | ||
b28ab83c PZ |
6425 | struct swevent_htable { |
6426 | struct swevent_hlist *swevent_hlist; | |
6427 | struct mutex hlist_mutex; | |
6428 | int hlist_refcount; | |
6429 | ||
6430 | /* Recursion avoidance in each contexts */ | |
6431 | int recursion[PERF_NR_CONTEXTS]; | |
6432 | }; | |
6433 | ||
6434 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6435 | ||
7b4b6658 | 6436 | /* |
cdd6c482 IM |
6437 | * We directly increment event->count and keep a second value in |
6438 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6439 | * is kept in the range [-sample_period, 0] so that we can use the |
6440 | * sign as trigger. | |
6441 | */ | |
6442 | ||
ab573844 | 6443 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6444 | { |
cdd6c482 | 6445 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6446 | u64 period = hwc->last_period; |
6447 | u64 nr, offset; | |
6448 | s64 old, val; | |
6449 | ||
6450 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6451 | |
6452 | again: | |
e7850595 | 6453 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6454 | if (val < 0) |
6455 | return 0; | |
15dbf27c | 6456 | |
7b4b6658 PZ |
6457 | nr = div64_u64(period + val, period); |
6458 | offset = nr * period; | |
6459 | val -= offset; | |
e7850595 | 6460 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6461 | goto again; |
15dbf27c | 6462 | |
7b4b6658 | 6463 | return nr; |
15dbf27c PZ |
6464 | } |
6465 | ||
0cff784a | 6466 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6467 | struct perf_sample_data *data, |
5622f295 | 6468 | struct pt_regs *regs) |
15dbf27c | 6469 | { |
cdd6c482 | 6470 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6471 | int throttle = 0; |
15dbf27c | 6472 | |
0cff784a PZ |
6473 | if (!overflow) |
6474 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6475 | |
7b4b6658 PZ |
6476 | if (hwc->interrupts == MAX_INTERRUPTS) |
6477 | return; | |
15dbf27c | 6478 | |
7b4b6658 | 6479 | for (; overflow; overflow--) { |
a8b0ca17 | 6480 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6481 | data, regs)) { |
7b4b6658 PZ |
6482 | /* |
6483 | * We inhibit the overflow from happening when | |
6484 | * hwc->interrupts == MAX_INTERRUPTS. | |
6485 | */ | |
6486 | break; | |
6487 | } | |
cf450a73 | 6488 | throttle = 1; |
7b4b6658 | 6489 | } |
15dbf27c PZ |
6490 | } |
6491 | ||
a4eaf7f1 | 6492 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6493 | struct perf_sample_data *data, |
5622f295 | 6494 | struct pt_regs *regs) |
7b4b6658 | 6495 | { |
cdd6c482 | 6496 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6497 | |
e7850595 | 6498 | local64_add(nr, &event->count); |
d6d020e9 | 6499 | |
0cff784a PZ |
6500 | if (!regs) |
6501 | return; | |
6502 | ||
6c7e550f | 6503 | if (!is_sampling_event(event)) |
7b4b6658 | 6504 | return; |
d6d020e9 | 6505 | |
5d81e5cf AV |
6506 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6507 | data->period = nr; | |
6508 | return perf_swevent_overflow(event, 1, data, regs); | |
6509 | } else | |
6510 | data->period = event->hw.last_period; | |
6511 | ||
0cff784a | 6512 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6513 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6514 | |
e7850595 | 6515 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6516 | return; |
df1a132b | 6517 | |
a8b0ca17 | 6518 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6519 | } |
6520 | ||
f5ffe02e FW |
6521 | static int perf_exclude_event(struct perf_event *event, |
6522 | struct pt_regs *regs) | |
6523 | { | |
a4eaf7f1 | 6524 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6525 | return 1; |
a4eaf7f1 | 6526 | |
f5ffe02e FW |
6527 | if (regs) { |
6528 | if (event->attr.exclude_user && user_mode(regs)) | |
6529 | return 1; | |
6530 | ||
6531 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6532 | return 1; | |
6533 | } | |
6534 | ||
6535 | return 0; | |
6536 | } | |
6537 | ||
cdd6c482 | 6538 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6539 | enum perf_type_id type, |
6fb2915d LZ |
6540 | u32 event_id, |
6541 | struct perf_sample_data *data, | |
6542 | struct pt_regs *regs) | |
15dbf27c | 6543 | { |
cdd6c482 | 6544 | if (event->attr.type != type) |
a21ca2ca | 6545 | return 0; |
f5ffe02e | 6546 | |
cdd6c482 | 6547 | if (event->attr.config != event_id) |
15dbf27c PZ |
6548 | return 0; |
6549 | ||
f5ffe02e FW |
6550 | if (perf_exclude_event(event, regs)) |
6551 | return 0; | |
15dbf27c PZ |
6552 | |
6553 | return 1; | |
6554 | } | |
6555 | ||
76e1d904 FW |
6556 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6557 | { | |
6558 | u64 val = event_id | (type << 32); | |
6559 | ||
6560 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6561 | } | |
6562 | ||
49f135ed FW |
6563 | static inline struct hlist_head * |
6564 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6565 | { |
49f135ed FW |
6566 | u64 hash = swevent_hash(type, event_id); |
6567 | ||
6568 | return &hlist->heads[hash]; | |
6569 | } | |
76e1d904 | 6570 | |
49f135ed FW |
6571 | /* For the read side: events when they trigger */ |
6572 | static inline struct hlist_head * | |
b28ab83c | 6573 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6574 | { |
6575 | struct swevent_hlist *hlist; | |
76e1d904 | 6576 | |
b28ab83c | 6577 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6578 | if (!hlist) |
6579 | return NULL; | |
6580 | ||
49f135ed FW |
6581 | return __find_swevent_head(hlist, type, event_id); |
6582 | } | |
6583 | ||
6584 | /* For the event head insertion and removal in the hlist */ | |
6585 | static inline struct hlist_head * | |
b28ab83c | 6586 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6587 | { |
6588 | struct swevent_hlist *hlist; | |
6589 | u32 event_id = event->attr.config; | |
6590 | u64 type = event->attr.type; | |
6591 | ||
6592 | /* | |
6593 | * Event scheduling is always serialized against hlist allocation | |
6594 | * and release. Which makes the protected version suitable here. | |
6595 | * The context lock guarantees that. | |
6596 | */ | |
b28ab83c | 6597 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6598 | lockdep_is_held(&event->ctx->lock)); |
6599 | if (!hlist) | |
6600 | return NULL; | |
6601 | ||
6602 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6603 | } |
6604 | ||
6605 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6606 | u64 nr, |
76e1d904 FW |
6607 | struct perf_sample_data *data, |
6608 | struct pt_regs *regs) | |
15dbf27c | 6609 | { |
4a32fea9 | 6610 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6611 | struct perf_event *event; |
76e1d904 | 6612 | struct hlist_head *head; |
15dbf27c | 6613 | |
76e1d904 | 6614 | rcu_read_lock(); |
b28ab83c | 6615 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6616 | if (!head) |
6617 | goto end; | |
6618 | ||
b67bfe0d | 6619 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6620 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6621 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6622 | } |
76e1d904 FW |
6623 | end: |
6624 | rcu_read_unlock(); | |
15dbf27c PZ |
6625 | } |
6626 | ||
86038c5e PZI |
6627 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6628 | ||
4ed7c92d | 6629 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6630 | { |
4a32fea9 | 6631 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6632 | |
b28ab83c | 6633 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6634 | } |
645e8cc0 | 6635 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6636 | |
fa9f90be | 6637 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6638 | { |
4a32fea9 | 6639 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6640 | |
b28ab83c | 6641 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6642 | } |
15dbf27c | 6643 | |
86038c5e | 6644 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6645 | { |
a4234bfc | 6646 | struct perf_sample_data data; |
4ed7c92d | 6647 | |
86038c5e | 6648 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6649 | return; |
a4234bfc | 6650 | |
fd0d000b | 6651 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6652 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6653 | } |
6654 | ||
6655 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6656 | { | |
6657 | int rctx; | |
6658 | ||
6659 | preempt_disable_notrace(); | |
6660 | rctx = perf_swevent_get_recursion_context(); | |
6661 | if (unlikely(rctx < 0)) | |
6662 | goto fail; | |
6663 | ||
6664 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6665 | |
6666 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6667 | fail: |
1c024eca | 6668 | preempt_enable_notrace(); |
b8e83514 PZ |
6669 | } |
6670 | ||
cdd6c482 | 6671 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6672 | { |
15dbf27c PZ |
6673 | } |
6674 | ||
a4eaf7f1 | 6675 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6676 | { |
4a32fea9 | 6677 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6678 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6679 | struct hlist_head *head; |
6680 | ||
6c7e550f | 6681 | if (is_sampling_event(event)) { |
7b4b6658 | 6682 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6683 | perf_swevent_set_period(event); |
7b4b6658 | 6684 | } |
76e1d904 | 6685 | |
a4eaf7f1 PZ |
6686 | hwc->state = !(flags & PERF_EF_START); |
6687 | ||
b28ab83c | 6688 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6689 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6690 | return -EINVAL; |
6691 | ||
6692 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6693 | perf_event_update_userpage(event); |
76e1d904 | 6694 | |
15dbf27c PZ |
6695 | return 0; |
6696 | } | |
6697 | ||
a4eaf7f1 | 6698 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6699 | { |
76e1d904 | 6700 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6701 | } |
6702 | ||
a4eaf7f1 | 6703 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6704 | { |
a4eaf7f1 | 6705 | event->hw.state = 0; |
d6d020e9 | 6706 | } |
aa9c4c0f | 6707 | |
a4eaf7f1 | 6708 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6709 | { |
a4eaf7f1 | 6710 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6711 | } |
6712 | ||
49f135ed FW |
6713 | /* Deref the hlist from the update side */ |
6714 | static inline struct swevent_hlist * | |
b28ab83c | 6715 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6716 | { |
b28ab83c PZ |
6717 | return rcu_dereference_protected(swhash->swevent_hlist, |
6718 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6719 | } |
6720 | ||
b28ab83c | 6721 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6722 | { |
b28ab83c | 6723 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6724 | |
49f135ed | 6725 | if (!hlist) |
76e1d904 FW |
6726 | return; |
6727 | ||
70691d4a | 6728 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6729 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6730 | } |
6731 | ||
6732 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6733 | { | |
b28ab83c | 6734 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6735 | |
b28ab83c | 6736 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6737 | |
b28ab83c PZ |
6738 | if (!--swhash->hlist_refcount) |
6739 | swevent_hlist_release(swhash); | |
76e1d904 | 6740 | |
b28ab83c | 6741 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6742 | } |
6743 | ||
6744 | static void swevent_hlist_put(struct perf_event *event) | |
6745 | { | |
6746 | int cpu; | |
6747 | ||
76e1d904 FW |
6748 | for_each_possible_cpu(cpu) |
6749 | swevent_hlist_put_cpu(event, cpu); | |
6750 | } | |
6751 | ||
6752 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6753 | { | |
b28ab83c | 6754 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6755 | int err = 0; |
6756 | ||
b28ab83c | 6757 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6758 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6759 | struct swevent_hlist *hlist; |
6760 | ||
6761 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6762 | if (!hlist) { | |
6763 | err = -ENOMEM; | |
6764 | goto exit; | |
6765 | } | |
b28ab83c | 6766 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6767 | } |
b28ab83c | 6768 | swhash->hlist_refcount++; |
9ed6060d | 6769 | exit: |
b28ab83c | 6770 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6771 | |
6772 | return err; | |
6773 | } | |
6774 | ||
6775 | static int swevent_hlist_get(struct perf_event *event) | |
6776 | { | |
6777 | int err; | |
6778 | int cpu, failed_cpu; | |
6779 | ||
76e1d904 FW |
6780 | get_online_cpus(); |
6781 | for_each_possible_cpu(cpu) { | |
6782 | err = swevent_hlist_get_cpu(event, cpu); | |
6783 | if (err) { | |
6784 | failed_cpu = cpu; | |
6785 | goto fail; | |
6786 | } | |
6787 | } | |
6788 | put_online_cpus(); | |
6789 | ||
6790 | return 0; | |
9ed6060d | 6791 | fail: |
76e1d904 FW |
6792 | for_each_possible_cpu(cpu) { |
6793 | if (cpu == failed_cpu) | |
6794 | break; | |
6795 | swevent_hlist_put_cpu(event, cpu); | |
6796 | } | |
6797 | ||
6798 | put_online_cpus(); | |
6799 | return err; | |
6800 | } | |
6801 | ||
c5905afb | 6802 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6803 | |
b0a873eb PZ |
6804 | static void sw_perf_event_destroy(struct perf_event *event) |
6805 | { | |
6806 | u64 event_id = event->attr.config; | |
95476b64 | 6807 | |
b0a873eb PZ |
6808 | WARN_ON(event->parent); |
6809 | ||
c5905afb | 6810 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6811 | swevent_hlist_put(event); |
6812 | } | |
6813 | ||
6814 | static int perf_swevent_init(struct perf_event *event) | |
6815 | { | |
8176cced | 6816 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6817 | |
6818 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6819 | return -ENOENT; | |
6820 | ||
2481c5fa SE |
6821 | /* |
6822 | * no branch sampling for software events | |
6823 | */ | |
6824 | if (has_branch_stack(event)) | |
6825 | return -EOPNOTSUPP; | |
6826 | ||
b0a873eb PZ |
6827 | switch (event_id) { |
6828 | case PERF_COUNT_SW_CPU_CLOCK: | |
6829 | case PERF_COUNT_SW_TASK_CLOCK: | |
6830 | return -ENOENT; | |
6831 | ||
6832 | default: | |
6833 | break; | |
6834 | } | |
6835 | ||
ce677831 | 6836 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6837 | return -ENOENT; |
6838 | ||
6839 | if (!event->parent) { | |
6840 | int err; | |
6841 | ||
6842 | err = swevent_hlist_get(event); | |
6843 | if (err) | |
6844 | return err; | |
6845 | ||
c5905afb | 6846 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6847 | event->destroy = sw_perf_event_destroy; |
6848 | } | |
6849 | ||
6850 | return 0; | |
6851 | } | |
6852 | ||
6853 | static struct pmu perf_swevent = { | |
89a1e187 | 6854 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6855 | |
34f43927 PZ |
6856 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6857 | ||
b0a873eb | 6858 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6859 | .add = perf_swevent_add, |
6860 | .del = perf_swevent_del, | |
6861 | .start = perf_swevent_start, | |
6862 | .stop = perf_swevent_stop, | |
1c024eca | 6863 | .read = perf_swevent_read, |
1c024eca PZ |
6864 | }; |
6865 | ||
b0a873eb PZ |
6866 | #ifdef CONFIG_EVENT_TRACING |
6867 | ||
1c024eca PZ |
6868 | static int perf_tp_filter_match(struct perf_event *event, |
6869 | struct perf_sample_data *data) | |
6870 | { | |
6871 | void *record = data->raw->data; | |
6872 | ||
b71b437e PZ |
6873 | /* only top level events have filters set */ |
6874 | if (event->parent) | |
6875 | event = event->parent; | |
6876 | ||
1c024eca PZ |
6877 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6878 | return 1; | |
6879 | return 0; | |
6880 | } | |
6881 | ||
6882 | static int perf_tp_event_match(struct perf_event *event, | |
6883 | struct perf_sample_data *data, | |
6884 | struct pt_regs *regs) | |
6885 | { | |
a0f7d0f7 FW |
6886 | if (event->hw.state & PERF_HES_STOPPED) |
6887 | return 0; | |
580d607c PZ |
6888 | /* |
6889 | * All tracepoints are from kernel-space. | |
6890 | */ | |
6891 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6892 | return 0; |
6893 | ||
6894 | if (!perf_tp_filter_match(event, data)) | |
6895 | return 0; | |
6896 | ||
6897 | return 1; | |
6898 | } | |
6899 | ||
6900 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6901 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6902 | struct task_struct *task) | |
95476b64 FW |
6903 | { |
6904 | struct perf_sample_data data; | |
1c024eca | 6905 | struct perf_event *event; |
1c024eca | 6906 | |
95476b64 FW |
6907 | struct perf_raw_record raw = { |
6908 | .size = entry_size, | |
6909 | .data = record, | |
6910 | }; | |
6911 | ||
fd0d000b | 6912 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6913 | data.raw = &raw; |
6914 | ||
b67bfe0d | 6915 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6916 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6917 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6918 | } |
ecc55f84 | 6919 | |
e6dab5ff AV |
6920 | /* |
6921 | * If we got specified a target task, also iterate its context and | |
6922 | * deliver this event there too. | |
6923 | */ | |
6924 | if (task && task != current) { | |
6925 | struct perf_event_context *ctx; | |
6926 | struct trace_entry *entry = record; | |
6927 | ||
6928 | rcu_read_lock(); | |
6929 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6930 | if (!ctx) | |
6931 | goto unlock; | |
6932 | ||
6933 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6934 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6935 | continue; | |
6936 | if (event->attr.config != entry->type) | |
6937 | continue; | |
6938 | if (perf_tp_event_match(event, &data, regs)) | |
6939 | perf_swevent_event(event, count, &data, regs); | |
6940 | } | |
6941 | unlock: | |
6942 | rcu_read_unlock(); | |
6943 | } | |
6944 | ||
ecc55f84 | 6945 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6946 | } |
6947 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6948 | ||
cdd6c482 | 6949 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6950 | { |
1c024eca | 6951 | perf_trace_destroy(event); |
e077df4f PZ |
6952 | } |
6953 | ||
b0a873eb | 6954 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6955 | { |
76e1d904 FW |
6956 | int err; |
6957 | ||
b0a873eb PZ |
6958 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6959 | return -ENOENT; | |
6960 | ||
2481c5fa SE |
6961 | /* |
6962 | * no branch sampling for tracepoint events | |
6963 | */ | |
6964 | if (has_branch_stack(event)) | |
6965 | return -EOPNOTSUPP; | |
6966 | ||
1c024eca PZ |
6967 | err = perf_trace_init(event); |
6968 | if (err) | |
b0a873eb | 6969 | return err; |
e077df4f | 6970 | |
cdd6c482 | 6971 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6972 | |
b0a873eb PZ |
6973 | return 0; |
6974 | } | |
6975 | ||
6976 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6977 | .task_ctx_nr = perf_sw_context, |
6978 | ||
b0a873eb | 6979 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6980 | .add = perf_trace_add, |
6981 | .del = perf_trace_del, | |
6982 | .start = perf_swevent_start, | |
6983 | .stop = perf_swevent_stop, | |
b0a873eb | 6984 | .read = perf_swevent_read, |
b0a873eb PZ |
6985 | }; |
6986 | ||
6987 | static inline void perf_tp_register(void) | |
6988 | { | |
2e80a82a | 6989 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6990 | } |
6fb2915d LZ |
6991 | |
6992 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6993 | { | |
6994 | char *filter_str; | |
6995 | int ret; | |
6996 | ||
6997 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6998 | return -EINVAL; | |
6999 | ||
7000 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7001 | if (IS_ERR(filter_str)) | |
7002 | return PTR_ERR(filter_str); | |
7003 | ||
7004 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
7005 | ||
7006 | kfree(filter_str); | |
7007 | return ret; | |
7008 | } | |
7009 | ||
7010 | static void perf_event_free_filter(struct perf_event *event) | |
7011 | { | |
7012 | ftrace_profile_free_filter(event); | |
7013 | } | |
7014 | ||
2541517c AS |
7015 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7016 | { | |
7017 | struct bpf_prog *prog; | |
7018 | ||
7019 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7020 | return -EINVAL; | |
7021 | ||
7022 | if (event->tp_event->prog) | |
7023 | return -EEXIST; | |
7024 | ||
04a22fae WN |
7025 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7026 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7027 | return -EINVAL; |
7028 | ||
7029 | prog = bpf_prog_get(prog_fd); | |
7030 | if (IS_ERR(prog)) | |
7031 | return PTR_ERR(prog); | |
7032 | ||
6c373ca8 | 7033 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7034 | /* valid fd, but invalid bpf program type */ |
7035 | bpf_prog_put(prog); | |
7036 | return -EINVAL; | |
7037 | } | |
7038 | ||
7039 | event->tp_event->prog = prog; | |
7040 | ||
7041 | return 0; | |
7042 | } | |
7043 | ||
7044 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7045 | { | |
7046 | struct bpf_prog *prog; | |
7047 | ||
7048 | if (!event->tp_event) | |
7049 | return; | |
7050 | ||
7051 | prog = event->tp_event->prog; | |
7052 | if (prog) { | |
7053 | event->tp_event->prog = NULL; | |
7054 | bpf_prog_put(prog); | |
7055 | } | |
7056 | } | |
7057 | ||
e077df4f | 7058 | #else |
6fb2915d | 7059 | |
b0a873eb | 7060 | static inline void perf_tp_register(void) |
e077df4f | 7061 | { |
e077df4f | 7062 | } |
6fb2915d LZ |
7063 | |
7064 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7065 | { | |
7066 | return -ENOENT; | |
7067 | } | |
7068 | ||
7069 | static void perf_event_free_filter(struct perf_event *event) | |
7070 | { | |
7071 | } | |
7072 | ||
2541517c AS |
7073 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7074 | { | |
7075 | return -ENOENT; | |
7076 | } | |
7077 | ||
7078 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7079 | { | |
7080 | } | |
07b139c8 | 7081 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7082 | |
24f1e32c | 7083 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7084 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7085 | { |
f5ffe02e FW |
7086 | struct perf_sample_data sample; |
7087 | struct pt_regs *regs = data; | |
7088 | ||
fd0d000b | 7089 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7090 | |
a4eaf7f1 | 7091 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7092 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7093 | } |
7094 | #endif | |
7095 | ||
b0a873eb PZ |
7096 | /* |
7097 | * hrtimer based swevent callback | |
7098 | */ | |
f29ac756 | 7099 | |
b0a873eb | 7100 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7101 | { |
b0a873eb PZ |
7102 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7103 | struct perf_sample_data data; | |
7104 | struct pt_regs *regs; | |
7105 | struct perf_event *event; | |
7106 | u64 period; | |
f29ac756 | 7107 | |
b0a873eb | 7108 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7109 | |
7110 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7111 | return HRTIMER_NORESTART; | |
7112 | ||
b0a873eb | 7113 | event->pmu->read(event); |
f344011c | 7114 | |
fd0d000b | 7115 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7116 | regs = get_irq_regs(); |
7117 | ||
7118 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7119 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7120 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7121 | ret = HRTIMER_NORESTART; |
7122 | } | |
24f1e32c | 7123 | |
b0a873eb PZ |
7124 | period = max_t(u64, 10000, event->hw.sample_period); |
7125 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7126 | |
b0a873eb | 7127 | return ret; |
f29ac756 PZ |
7128 | } |
7129 | ||
b0a873eb | 7130 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7131 | { |
b0a873eb | 7132 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7133 | s64 period; |
7134 | ||
7135 | if (!is_sampling_event(event)) | |
7136 | return; | |
f5ffe02e | 7137 | |
5d508e82 FBH |
7138 | period = local64_read(&hwc->period_left); |
7139 | if (period) { | |
7140 | if (period < 0) | |
7141 | period = 10000; | |
fa407f35 | 7142 | |
5d508e82 FBH |
7143 | local64_set(&hwc->period_left, 0); |
7144 | } else { | |
7145 | period = max_t(u64, 10000, hwc->sample_period); | |
7146 | } | |
3497d206 TG |
7147 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7148 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7149 | } |
b0a873eb PZ |
7150 | |
7151 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7152 | { |
b0a873eb PZ |
7153 | struct hw_perf_event *hwc = &event->hw; |
7154 | ||
6c7e550f | 7155 | if (is_sampling_event(event)) { |
b0a873eb | 7156 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7157 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7158 | |
7159 | hrtimer_cancel(&hwc->hrtimer); | |
7160 | } | |
24f1e32c FW |
7161 | } |
7162 | ||
ba3dd36c PZ |
7163 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7164 | { | |
7165 | struct hw_perf_event *hwc = &event->hw; | |
7166 | ||
7167 | if (!is_sampling_event(event)) | |
7168 | return; | |
7169 | ||
7170 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7171 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7172 | ||
7173 | /* | |
7174 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7175 | * mapping and avoid the whole period adjust feedback stuff. | |
7176 | */ | |
7177 | if (event->attr.freq) { | |
7178 | long freq = event->attr.sample_freq; | |
7179 | ||
7180 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7181 | hwc->sample_period = event->attr.sample_period; | |
7182 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7183 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7184 | event->attr.freq = 0; |
7185 | } | |
7186 | } | |
7187 | ||
b0a873eb PZ |
7188 | /* |
7189 | * Software event: cpu wall time clock | |
7190 | */ | |
7191 | ||
7192 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7193 | { |
b0a873eb PZ |
7194 | s64 prev; |
7195 | u64 now; | |
7196 | ||
a4eaf7f1 | 7197 | now = local_clock(); |
b0a873eb PZ |
7198 | prev = local64_xchg(&event->hw.prev_count, now); |
7199 | local64_add(now - prev, &event->count); | |
24f1e32c | 7200 | } |
24f1e32c | 7201 | |
a4eaf7f1 | 7202 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7203 | { |
a4eaf7f1 | 7204 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7205 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7206 | } |
7207 | ||
a4eaf7f1 | 7208 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7209 | { |
b0a873eb PZ |
7210 | perf_swevent_cancel_hrtimer(event); |
7211 | cpu_clock_event_update(event); | |
7212 | } | |
f29ac756 | 7213 | |
a4eaf7f1 PZ |
7214 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7215 | { | |
7216 | if (flags & PERF_EF_START) | |
7217 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7218 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7219 | |
7220 | return 0; | |
7221 | } | |
7222 | ||
7223 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7224 | { | |
7225 | cpu_clock_event_stop(event, flags); | |
7226 | } | |
7227 | ||
b0a873eb PZ |
7228 | static void cpu_clock_event_read(struct perf_event *event) |
7229 | { | |
7230 | cpu_clock_event_update(event); | |
7231 | } | |
f344011c | 7232 | |
b0a873eb PZ |
7233 | static int cpu_clock_event_init(struct perf_event *event) |
7234 | { | |
7235 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7236 | return -ENOENT; | |
7237 | ||
7238 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7239 | return -ENOENT; | |
7240 | ||
2481c5fa SE |
7241 | /* |
7242 | * no branch sampling for software events | |
7243 | */ | |
7244 | if (has_branch_stack(event)) | |
7245 | return -EOPNOTSUPP; | |
7246 | ||
ba3dd36c PZ |
7247 | perf_swevent_init_hrtimer(event); |
7248 | ||
b0a873eb | 7249 | return 0; |
f29ac756 PZ |
7250 | } |
7251 | ||
b0a873eb | 7252 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7253 | .task_ctx_nr = perf_sw_context, |
7254 | ||
34f43927 PZ |
7255 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7256 | ||
b0a873eb | 7257 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7258 | .add = cpu_clock_event_add, |
7259 | .del = cpu_clock_event_del, | |
7260 | .start = cpu_clock_event_start, | |
7261 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7262 | .read = cpu_clock_event_read, |
7263 | }; | |
7264 | ||
7265 | /* | |
7266 | * Software event: task time clock | |
7267 | */ | |
7268 | ||
7269 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7270 | { |
b0a873eb PZ |
7271 | u64 prev; |
7272 | s64 delta; | |
5c92d124 | 7273 | |
b0a873eb PZ |
7274 | prev = local64_xchg(&event->hw.prev_count, now); |
7275 | delta = now - prev; | |
7276 | local64_add(delta, &event->count); | |
7277 | } | |
5c92d124 | 7278 | |
a4eaf7f1 | 7279 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7280 | { |
a4eaf7f1 | 7281 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7282 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7283 | } |
7284 | ||
a4eaf7f1 | 7285 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7286 | { |
7287 | perf_swevent_cancel_hrtimer(event); | |
7288 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7289 | } |
7290 | ||
7291 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7292 | { | |
7293 | if (flags & PERF_EF_START) | |
7294 | task_clock_event_start(event, flags); | |
6a694a60 | 7295 | perf_event_update_userpage(event); |
b0a873eb | 7296 | |
a4eaf7f1 PZ |
7297 | return 0; |
7298 | } | |
7299 | ||
7300 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7301 | { | |
7302 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7303 | } |
7304 | ||
7305 | static void task_clock_event_read(struct perf_event *event) | |
7306 | { | |
768a06e2 PZ |
7307 | u64 now = perf_clock(); |
7308 | u64 delta = now - event->ctx->timestamp; | |
7309 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7310 | |
7311 | task_clock_event_update(event, time); | |
7312 | } | |
7313 | ||
7314 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7315 | { |
b0a873eb PZ |
7316 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7317 | return -ENOENT; | |
7318 | ||
7319 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7320 | return -ENOENT; | |
7321 | ||
2481c5fa SE |
7322 | /* |
7323 | * no branch sampling for software events | |
7324 | */ | |
7325 | if (has_branch_stack(event)) | |
7326 | return -EOPNOTSUPP; | |
7327 | ||
ba3dd36c PZ |
7328 | perf_swevent_init_hrtimer(event); |
7329 | ||
b0a873eb | 7330 | return 0; |
6fb2915d LZ |
7331 | } |
7332 | ||
b0a873eb | 7333 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7334 | .task_ctx_nr = perf_sw_context, |
7335 | ||
34f43927 PZ |
7336 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7337 | ||
b0a873eb | 7338 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7339 | .add = task_clock_event_add, |
7340 | .del = task_clock_event_del, | |
7341 | .start = task_clock_event_start, | |
7342 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7343 | .read = task_clock_event_read, |
7344 | }; | |
6fb2915d | 7345 | |
ad5133b7 | 7346 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7347 | { |
e077df4f | 7348 | } |
6fb2915d | 7349 | |
fbbe0701 SB |
7350 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7351 | { | |
7352 | } | |
7353 | ||
ad5133b7 | 7354 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7355 | { |
ad5133b7 | 7356 | return 0; |
6fb2915d LZ |
7357 | } |
7358 | ||
18ab2cd3 | 7359 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7360 | |
7361 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7362 | { |
fbbe0701 SB |
7363 | __this_cpu_write(nop_txn_flags, flags); |
7364 | ||
7365 | if (flags & ~PERF_PMU_TXN_ADD) | |
7366 | return; | |
7367 | ||
ad5133b7 | 7368 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7369 | } |
7370 | ||
ad5133b7 PZ |
7371 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7372 | { | |
fbbe0701 SB |
7373 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7374 | ||
7375 | __this_cpu_write(nop_txn_flags, 0); | |
7376 | ||
7377 | if (flags & ~PERF_PMU_TXN_ADD) | |
7378 | return 0; | |
7379 | ||
ad5133b7 PZ |
7380 | perf_pmu_enable(pmu); |
7381 | return 0; | |
7382 | } | |
e077df4f | 7383 | |
ad5133b7 | 7384 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7385 | { |
fbbe0701 SB |
7386 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7387 | ||
7388 | __this_cpu_write(nop_txn_flags, 0); | |
7389 | ||
7390 | if (flags & ~PERF_PMU_TXN_ADD) | |
7391 | return; | |
7392 | ||
ad5133b7 | 7393 | perf_pmu_enable(pmu); |
24f1e32c FW |
7394 | } |
7395 | ||
35edc2a5 PZ |
7396 | static int perf_event_idx_default(struct perf_event *event) |
7397 | { | |
c719f560 | 7398 | return 0; |
35edc2a5 PZ |
7399 | } |
7400 | ||
8dc85d54 PZ |
7401 | /* |
7402 | * Ensures all contexts with the same task_ctx_nr have the same | |
7403 | * pmu_cpu_context too. | |
7404 | */ | |
9e317041 | 7405 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7406 | { |
8dc85d54 | 7407 | struct pmu *pmu; |
b326e956 | 7408 | |
8dc85d54 PZ |
7409 | if (ctxn < 0) |
7410 | return NULL; | |
24f1e32c | 7411 | |
8dc85d54 PZ |
7412 | list_for_each_entry(pmu, &pmus, entry) { |
7413 | if (pmu->task_ctx_nr == ctxn) | |
7414 | return pmu->pmu_cpu_context; | |
7415 | } | |
24f1e32c | 7416 | |
8dc85d54 | 7417 | return NULL; |
24f1e32c FW |
7418 | } |
7419 | ||
51676957 | 7420 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7421 | { |
51676957 PZ |
7422 | int cpu; |
7423 | ||
7424 | for_each_possible_cpu(cpu) { | |
7425 | struct perf_cpu_context *cpuctx; | |
7426 | ||
7427 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7428 | ||
3f1f3320 PZ |
7429 | if (cpuctx->unique_pmu == old_pmu) |
7430 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7431 | } |
7432 | } | |
7433 | ||
7434 | static void free_pmu_context(struct pmu *pmu) | |
7435 | { | |
7436 | struct pmu *i; | |
f5ffe02e | 7437 | |
8dc85d54 | 7438 | mutex_lock(&pmus_lock); |
0475f9ea | 7439 | /* |
8dc85d54 | 7440 | * Like a real lame refcount. |
0475f9ea | 7441 | */ |
51676957 PZ |
7442 | list_for_each_entry(i, &pmus, entry) { |
7443 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7444 | update_pmu_context(i, pmu); | |
8dc85d54 | 7445 | goto out; |
51676957 | 7446 | } |
8dc85d54 | 7447 | } |
d6d020e9 | 7448 | |
51676957 | 7449 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7450 | out: |
7451 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7452 | } |
2e80a82a | 7453 | static struct idr pmu_idr; |
d6d020e9 | 7454 | |
abe43400 PZ |
7455 | static ssize_t |
7456 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7457 | { | |
7458 | struct pmu *pmu = dev_get_drvdata(dev); | |
7459 | ||
7460 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7461 | } | |
90826ca7 | 7462 | static DEVICE_ATTR_RO(type); |
abe43400 | 7463 | |
62b85639 SE |
7464 | static ssize_t |
7465 | perf_event_mux_interval_ms_show(struct device *dev, | |
7466 | struct device_attribute *attr, | |
7467 | char *page) | |
7468 | { | |
7469 | struct pmu *pmu = dev_get_drvdata(dev); | |
7470 | ||
7471 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7472 | } | |
7473 | ||
272325c4 PZ |
7474 | static DEFINE_MUTEX(mux_interval_mutex); |
7475 | ||
62b85639 SE |
7476 | static ssize_t |
7477 | perf_event_mux_interval_ms_store(struct device *dev, | |
7478 | struct device_attribute *attr, | |
7479 | const char *buf, size_t count) | |
7480 | { | |
7481 | struct pmu *pmu = dev_get_drvdata(dev); | |
7482 | int timer, cpu, ret; | |
7483 | ||
7484 | ret = kstrtoint(buf, 0, &timer); | |
7485 | if (ret) | |
7486 | return ret; | |
7487 | ||
7488 | if (timer < 1) | |
7489 | return -EINVAL; | |
7490 | ||
7491 | /* same value, noting to do */ | |
7492 | if (timer == pmu->hrtimer_interval_ms) | |
7493 | return count; | |
7494 | ||
272325c4 | 7495 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7496 | pmu->hrtimer_interval_ms = timer; |
7497 | ||
7498 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7499 | get_online_cpus(); |
7500 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7501 | struct perf_cpu_context *cpuctx; |
7502 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7503 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7504 | ||
272325c4 PZ |
7505 | cpu_function_call(cpu, |
7506 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7507 | } |
272325c4 PZ |
7508 | put_online_cpus(); |
7509 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7510 | |
7511 | return count; | |
7512 | } | |
90826ca7 | 7513 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7514 | |
90826ca7 GKH |
7515 | static struct attribute *pmu_dev_attrs[] = { |
7516 | &dev_attr_type.attr, | |
7517 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7518 | NULL, | |
abe43400 | 7519 | }; |
90826ca7 | 7520 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7521 | |
7522 | static int pmu_bus_running; | |
7523 | static struct bus_type pmu_bus = { | |
7524 | .name = "event_source", | |
90826ca7 | 7525 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7526 | }; |
7527 | ||
7528 | static void pmu_dev_release(struct device *dev) | |
7529 | { | |
7530 | kfree(dev); | |
7531 | } | |
7532 | ||
7533 | static int pmu_dev_alloc(struct pmu *pmu) | |
7534 | { | |
7535 | int ret = -ENOMEM; | |
7536 | ||
7537 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7538 | if (!pmu->dev) | |
7539 | goto out; | |
7540 | ||
0c9d42ed | 7541 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7542 | device_initialize(pmu->dev); |
7543 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7544 | if (ret) | |
7545 | goto free_dev; | |
7546 | ||
7547 | dev_set_drvdata(pmu->dev, pmu); | |
7548 | pmu->dev->bus = &pmu_bus; | |
7549 | pmu->dev->release = pmu_dev_release; | |
7550 | ret = device_add(pmu->dev); | |
7551 | if (ret) | |
7552 | goto free_dev; | |
7553 | ||
7554 | out: | |
7555 | return ret; | |
7556 | ||
7557 | free_dev: | |
7558 | put_device(pmu->dev); | |
7559 | goto out; | |
7560 | } | |
7561 | ||
547e9fd7 | 7562 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7563 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7564 | |
03d8e80b | 7565 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7566 | { |
108b02cf | 7567 | int cpu, ret; |
24f1e32c | 7568 | |
b0a873eb | 7569 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7570 | ret = -ENOMEM; |
7571 | pmu->pmu_disable_count = alloc_percpu(int); | |
7572 | if (!pmu->pmu_disable_count) | |
7573 | goto unlock; | |
f29ac756 | 7574 | |
2e80a82a PZ |
7575 | pmu->type = -1; |
7576 | if (!name) | |
7577 | goto skip_type; | |
7578 | pmu->name = name; | |
7579 | ||
7580 | if (type < 0) { | |
0e9c3be2 TH |
7581 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7582 | if (type < 0) { | |
7583 | ret = type; | |
2e80a82a PZ |
7584 | goto free_pdc; |
7585 | } | |
7586 | } | |
7587 | pmu->type = type; | |
7588 | ||
abe43400 PZ |
7589 | if (pmu_bus_running) { |
7590 | ret = pmu_dev_alloc(pmu); | |
7591 | if (ret) | |
7592 | goto free_idr; | |
7593 | } | |
7594 | ||
2e80a82a | 7595 | skip_type: |
8dc85d54 PZ |
7596 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7597 | if (pmu->pmu_cpu_context) | |
7598 | goto got_cpu_context; | |
f29ac756 | 7599 | |
c4814202 | 7600 | ret = -ENOMEM; |
108b02cf PZ |
7601 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7602 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7603 | goto free_dev; |
f344011c | 7604 | |
108b02cf PZ |
7605 | for_each_possible_cpu(cpu) { |
7606 | struct perf_cpu_context *cpuctx; | |
7607 | ||
7608 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7609 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7610 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7611 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7612 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7613 | |
272325c4 | 7614 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7615 | |
3f1f3320 | 7616 | cpuctx->unique_pmu = pmu; |
108b02cf | 7617 | } |
76e1d904 | 7618 | |
8dc85d54 | 7619 | got_cpu_context: |
ad5133b7 PZ |
7620 | if (!pmu->start_txn) { |
7621 | if (pmu->pmu_enable) { | |
7622 | /* | |
7623 | * If we have pmu_enable/pmu_disable calls, install | |
7624 | * transaction stubs that use that to try and batch | |
7625 | * hardware accesses. | |
7626 | */ | |
7627 | pmu->start_txn = perf_pmu_start_txn; | |
7628 | pmu->commit_txn = perf_pmu_commit_txn; | |
7629 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7630 | } else { | |
fbbe0701 | 7631 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7632 | pmu->commit_txn = perf_pmu_nop_int; |
7633 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7634 | } |
5c92d124 | 7635 | } |
15dbf27c | 7636 | |
ad5133b7 PZ |
7637 | if (!pmu->pmu_enable) { |
7638 | pmu->pmu_enable = perf_pmu_nop_void; | |
7639 | pmu->pmu_disable = perf_pmu_nop_void; | |
7640 | } | |
7641 | ||
35edc2a5 PZ |
7642 | if (!pmu->event_idx) |
7643 | pmu->event_idx = perf_event_idx_default; | |
7644 | ||
b0a873eb | 7645 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7646 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7647 | ret = 0; |
7648 | unlock: | |
b0a873eb PZ |
7649 | mutex_unlock(&pmus_lock); |
7650 | ||
33696fc0 | 7651 | return ret; |
108b02cf | 7652 | |
abe43400 PZ |
7653 | free_dev: |
7654 | device_del(pmu->dev); | |
7655 | put_device(pmu->dev); | |
7656 | ||
2e80a82a PZ |
7657 | free_idr: |
7658 | if (pmu->type >= PERF_TYPE_MAX) | |
7659 | idr_remove(&pmu_idr, pmu->type); | |
7660 | ||
108b02cf PZ |
7661 | free_pdc: |
7662 | free_percpu(pmu->pmu_disable_count); | |
7663 | goto unlock; | |
f29ac756 | 7664 | } |
c464c76e | 7665 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7666 | |
b0a873eb | 7667 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7668 | { |
b0a873eb PZ |
7669 | mutex_lock(&pmus_lock); |
7670 | list_del_rcu(&pmu->entry); | |
7671 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7672 | |
0475f9ea | 7673 | /* |
cde8e884 PZ |
7674 | * We dereference the pmu list under both SRCU and regular RCU, so |
7675 | * synchronize against both of those. | |
0475f9ea | 7676 | */ |
b0a873eb | 7677 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7678 | synchronize_rcu(); |
d6d020e9 | 7679 | |
33696fc0 | 7680 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7681 | if (pmu->type >= PERF_TYPE_MAX) |
7682 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7683 | device_del(pmu->dev); |
7684 | put_device(pmu->dev); | |
51676957 | 7685 | free_pmu_context(pmu); |
b0a873eb | 7686 | } |
c464c76e | 7687 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7688 | |
cc34b98b MR |
7689 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7690 | { | |
ccd41c86 | 7691 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7692 | int ret; |
7693 | ||
7694 | if (!try_module_get(pmu->module)) | |
7695 | return -ENODEV; | |
ccd41c86 PZ |
7696 | |
7697 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7698 | /* |
7699 | * This ctx->mutex can nest when we're called through | |
7700 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7701 | */ | |
7702 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7703 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7704 | BUG_ON(!ctx); |
7705 | } | |
7706 | ||
cc34b98b MR |
7707 | event->pmu = pmu; |
7708 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7709 | |
7710 | if (ctx) | |
7711 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7712 | ||
cc34b98b MR |
7713 | if (ret) |
7714 | module_put(pmu->module); | |
7715 | ||
7716 | return ret; | |
7717 | } | |
7718 | ||
18ab2cd3 | 7719 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7720 | { |
7721 | struct pmu *pmu = NULL; | |
7722 | int idx; | |
940c5b29 | 7723 | int ret; |
b0a873eb PZ |
7724 | |
7725 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7726 | |
7727 | rcu_read_lock(); | |
7728 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7729 | rcu_read_unlock(); | |
940c5b29 | 7730 | if (pmu) { |
cc34b98b | 7731 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7732 | if (ret) |
7733 | pmu = ERR_PTR(ret); | |
2e80a82a | 7734 | goto unlock; |
940c5b29 | 7735 | } |
2e80a82a | 7736 | |
b0a873eb | 7737 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7738 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7739 | if (!ret) |
e5f4d339 | 7740 | goto unlock; |
76e1d904 | 7741 | |
b0a873eb PZ |
7742 | if (ret != -ENOENT) { |
7743 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7744 | goto unlock; |
f344011c | 7745 | } |
5c92d124 | 7746 | } |
e5f4d339 PZ |
7747 | pmu = ERR_PTR(-ENOENT); |
7748 | unlock: | |
b0a873eb | 7749 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7750 | |
4aeb0b42 | 7751 | return pmu; |
5c92d124 IM |
7752 | } |
7753 | ||
4beb31f3 FW |
7754 | static void account_event_cpu(struct perf_event *event, int cpu) |
7755 | { | |
7756 | if (event->parent) | |
7757 | return; | |
7758 | ||
4beb31f3 FW |
7759 | if (is_cgroup_event(event)) |
7760 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7761 | } | |
7762 | ||
766d6c07 FW |
7763 | static void account_event(struct perf_event *event) |
7764 | { | |
25432ae9 PZ |
7765 | bool inc = false; |
7766 | ||
4beb31f3 FW |
7767 | if (event->parent) |
7768 | return; | |
7769 | ||
766d6c07 | 7770 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7771 | inc = true; |
766d6c07 FW |
7772 | if (event->attr.mmap || event->attr.mmap_data) |
7773 | atomic_inc(&nr_mmap_events); | |
7774 | if (event->attr.comm) | |
7775 | atomic_inc(&nr_comm_events); | |
7776 | if (event->attr.task) | |
7777 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7778 | if (event->attr.freq) { |
7779 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7780 | tick_nohz_full_kick_all(); | |
7781 | } | |
45ac1403 AH |
7782 | if (event->attr.context_switch) { |
7783 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7784 | inc = true; |
45ac1403 | 7785 | } |
4beb31f3 | 7786 | if (has_branch_stack(event)) |
25432ae9 | 7787 | inc = true; |
4beb31f3 | 7788 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7789 | inc = true; |
7790 | ||
7791 | if (inc) | |
766d6c07 | 7792 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7793 | |
7794 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7795 | } |
7796 | ||
0793a61d | 7797 | /* |
cdd6c482 | 7798 | * Allocate and initialize a event structure |
0793a61d | 7799 | */ |
cdd6c482 | 7800 | static struct perf_event * |
c3f00c70 | 7801 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7802 | struct task_struct *task, |
7803 | struct perf_event *group_leader, | |
7804 | struct perf_event *parent_event, | |
4dc0da86 | 7805 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7806 | void *context, int cgroup_fd) |
0793a61d | 7807 | { |
51b0fe39 | 7808 | struct pmu *pmu; |
cdd6c482 IM |
7809 | struct perf_event *event; |
7810 | struct hw_perf_event *hwc; | |
90983b16 | 7811 | long err = -EINVAL; |
0793a61d | 7812 | |
66832eb4 ON |
7813 | if ((unsigned)cpu >= nr_cpu_ids) { |
7814 | if (!task || cpu != -1) | |
7815 | return ERR_PTR(-EINVAL); | |
7816 | } | |
7817 | ||
c3f00c70 | 7818 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7819 | if (!event) |
d5d2bc0d | 7820 | return ERR_PTR(-ENOMEM); |
0793a61d | 7821 | |
04289bb9 | 7822 | /* |
cdd6c482 | 7823 | * Single events are their own group leaders, with an |
04289bb9 IM |
7824 | * empty sibling list: |
7825 | */ | |
7826 | if (!group_leader) | |
cdd6c482 | 7827 | group_leader = event; |
04289bb9 | 7828 | |
cdd6c482 IM |
7829 | mutex_init(&event->child_mutex); |
7830 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7831 | |
cdd6c482 IM |
7832 | INIT_LIST_HEAD(&event->group_entry); |
7833 | INIT_LIST_HEAD(&event->event_entry); | |
7834 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7835 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7836 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7837 | INIT_HLIST_NODE(&event->hlist_entry); |
7838 | ||
10c6db11 | 7839 | |
cdd6c482 | 7840 | init_waitqueue_head(&event->waitq); |
e360adbe | 7841 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7842 | |
cdd6c482 | 7843 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7844 | |
a6fa941d | 7845 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7846 | event->cpu = cpu; |
7847 | event->attr = *attr; | |
7848 | event->group_leader = group_leader; | |
7849 | event->pmu = NULL; | |
cdd6c482 | 7850 | event->oncpu = -1; |
a96bbc16 | 7851 | |
cdd6c482 | 7852 | event->parent = parent_event; |
b84fbc9f | 7853 | |
17cf22c3 | 7854 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7855 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7856 | |
cdd6c482 | 7857 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7858 | |
d580ff86 PZ |
7859 | if (task) { |
7860 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7861 | /* |
50f16a8b PZ |
7862 | * XXX pmu::event_init needs to know what task to account to |
7863 | * and we cannot use the ctx information because we need the | |
7864 | * pmu before we get a ctx. | |
d580ff86 | 7865 | */ |
50f16a8b | 7866 | event->hw.target = task; |
d580ff86 PZ |
7867 | } |
7868 | ||
34f43927 PZ |
7869 | event->clock = &local_clock; |
7870 | if (parent_event) | |
7871 | event->clock = parent_event->clock; | |
7872 | ||
4dc0da86 | 7873 | if (!overflow_handler && parent_event) { |
b326e956 | 7874 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7875 | context = parent_event->overflow_handler_context; |
7876 | } | |
66832eb4 | 7877 | |
b326e956 | 7878 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7879 | event->overflow_handler_context = context; |
97eaf530 | 7880 | |
0231bb53 | 7881 | perf_event__state_init(event); |
a86ed508 | 7882 | |
4aeb0b42 | 7883 | pmu = NULL; |
b8e83514 | 7884 | |
cdd6c482 | 7885 | hwc = &event->hw; |
bd2b5b12 | 7886 | hwc->sample_period = attr->sample_period; |
0d48696f | 7887 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7888 | hwc->sample_period = 1; |
eced1dfc | 7889 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7890 | |
e7850595 | 7891 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7892 | |
2023b359 | 7893 | /* |
cdd6c482 | 7894 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7895 | */ |
3dab77fb | 7896 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7897 | goto err_ns; |
a46a2300 YZ |
7898 | |
7899 | if (!has_branch_stack(event)) | |
7900 | event->attr.branch_sample_type = 0; | |
2023b359 | 7901 | |
79dff51e MF |
7902 | if (cgroup_fd != -1) { |
7903 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7904 | if (err) | |
7905 | goto err_ns; | |
7906 | } | |
7907 | ||
b0a873eb | 7908 | pmu = perf_init_event(event); |
4aeb0b42 | 7909 | if (!pmu) |
90983b16 FW |
7910 | goto err_ns; |
7911 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7912 | err = PTR_ERR(pmu); |
90983b16 | 7913 | goto err_ns; |
621a01ea | 7914 | } |
d5d2bc0d | 7915 | |
bed5b25a AS |
7916 | err = exclusive_event_init(event); |
7917 | if (err) | |
7918 | goto err_pmu; | |
7919 | ||
cdd6c482 | 7920 | if (!event->parent) { |
927c7a9e FW |
7921 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7922 | err = get_callchain_buffers(); | |
90983b16 | 7923 | if (err) |
bed5b25a | 7924 | goto err_per_task; |
d010b332 | 7925 | } |
f344011c | 7926 | } |
9ee318a7 | 7927 | |
cdd6c482 | 7928 | return event; |
90983b16 | 7929 | |
bed5b25a AS |
7930 | err_per_task: |
7931 | exclusive_event_destroy(event); | |
7932 | ||
90983b16 FW |
7933 | err_pmu: |
7934 | if (event->destroy) | |
7935 | event->destroy(event); | |
c464c76e | 7936 | module_put(pmu->module); |
90983b16 | 7937 | err_ns: |
79dff51e MF |
7938 | if (is_cgroup_event(event)) |
7939 | perf_detach_cgroup(event); | |
90983b16 FW |
7940 | if (event->ns) |
7941 | put_pid_ns(event->ns); | |
7942 | kfree(event); | |
7943 | ||
7944 | return ERR_PTR(err); | |
0793a61d TG |
7945 | } |
7946 | ||
cdd6c482 IM |
7947 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7948 | struct perf_event_attr *attr) | |
974802ea | 7949 | { |
974802ea | 7950 | u32 size; |
cdf8073d | 7951 | int ret; |
974802ea PZ |
7952 | |
7953 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7954 | return -EFAULT; | |
7955 | ||
7956 | /* | |
7957 | * zero the full structure, so that a short copy will be nice. | |
7958 | */ | |
7959 | memset(attr, 0, sizeof(*attr)); | |
7960 | ||
7961 | ret = get_user(size, &uattr->size); | |
7962 | if (ret) | |
7963 | return ret; | |
7964 | ||
7965 | if (size > PAGE_SIZE) /* silly large */ | |
7966 | goto err_size; | |
7967 | ||
7968 | if (!size) /* abi compat */ | |
7969 | size = PERF_ATTR_SIZE_VER0; | |
7970 | ||
7971 | if (size < PERF_ATTR_SIZE_VER0) | |
7972 | goto err_size; | |
7973 | ||
7974 | /* | |
7975 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7976 | * ensure all the unknown bits are 0 - i.e. new |
7977 | * user-space does not rely on any kernel feature | |
7978 | * extensions we dont know about yet. | |
974802ea PZ |
7979 | */ |
7980 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7981 | unsigned char __user *addr; |
7982 | unsigned char __user *end; | |
7983 | unsigned char val; | |
974802ea | 7984 | |
cdf8073d IS |
7985 | addr = (void __user *)uattr + sizeof(*attr); |
7986 | end = (void __user *)uattr + size; | |
974802ea | 7987 | |
cdf8073d | 7988 | for (; addr < end; addr++) { |
974802ea PZ |
7989 | ret = get_user(val, addr); |
7990 | if (ret) | |
7991 | return ret; | |
7992 | if (val) | |
7993 | goto err_size; | |
7994 | } | |
b3e62e35 | 7995 | size = sizeof(*attr); |
974802ea PZ |
7996 | } |
7997 | ||
7998 | ret = copy_from_user(attr, uattr, size); | |
7999 | if (ret) | |
8000 | return -EFAULT; | |
8001 | ||
cd757645 | 8002 | if (attr->__reserved_1) |
974802ea PZ |
8003 | return -EINVAL; |
8004 | ||
8005 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8006 | return -EINVAL; | |
8007 | ||
8008 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8009 | return -EINVAL; | |
8010 | ||
bce38cd5 SE |
8011 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8012 | u64 mask = attr->branch_sample_type; | |
8013 | ||
8014 | /* only using defined bits */ | |
8015 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8016 | return -EINVAL; | |
8017 | ||
8018 | /* at least one branch bit must be set */ | |
8019 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8020 | return -EINVAL; | |
8021 | ||
bce38cd5 SE |
8022 | /* propagate priv level, when not set for branch */ |
8023 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8024 | ||
8025 | /* exclude_kernel checked on syscall entry */ | |
8026 | if (!attr->exclude_kernel) | |
8027 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8028 | ||
8029 | if (!attr->exclude_user) | |
8030 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8031 | ||
8032 | if (!attr->exclude_hv) | |
8033 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8034 | /* | |
8035 | * adjust user setting (for HW filter setup) | |
8036 | */ | |
8037 | attr->branch_sample_type = mask; | |
8038 | } | |
e712209a SE |
8039 | /* privileged levels capture (kernel, hv): check permissions */ |
8040 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8041 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8042 | return -EACCES; | |
bce38cd5 | 8043 | } |
4018994f | 8044 | |
c5ebcedb | 8045 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8046 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8047 | if (ret) |
8048 | return ret; | |
8049 | } | |
8050 | ||
8051 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8052 | if (!arch_perf_have_user_stack_dump()) | |
8053 | return -ENOSYS; | |
8054 | ||
8055 | /* | |
8056 | * We have __u32 type for the size, but so far | |
8057 | * we can only use __u16 as maximum due to the | |
8058 | * __u16 sample size limit. | |
8059 | */ | |
8060 | if (attr->sample_stack_user >= USHRT_MAX) | |
8061 | ret = -EINVAL; | |
8062 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8063 | ret = -EINVAL; | |
8064 | } | |
4018994f | 8065 | |
60e2364e SE |
8066 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8067 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8068 | out: |
8069 | return ret; | |
8070 | ||
8071 | err_size: | |
8072 | put_user(sizeof(*attr), &uattr->size); | |
8073 | ret = -E2BIG; | |
8074 | goto out; | |
8075 | } | |
8076 | ||
ac9721f3 PZ |
8077 | static int |
8078 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8079 | { |
b69cf536 | 8080 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8081 | int ret = -EINVAL; |
8082 | ||
ac9721f3 | 8083 | if (!output_event) |
a4be7c27 PZ |
8084 | goto set; |
8085 | ||
ac9721f3 PZ |
8086 | /* don't allow circular references */ |
8087 | if (event == output_event) | |
a4be7c27 PZ |
8088 | goto out; |
8089 | ||
0f139300 PZ |
8090 | /* |
8091 | * Don't allow cross-cpu buffers | |
8092 | */ | |
8093 | if (output_event->cpu != event->cpu) | |
8094 | goto out; | |
8095 | ||
8096 | /* | |
76369139 | 8097 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8098 | */ |
8099 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8100 | goto out; | |
8101 | ||
34f43927 PZ |
8102 | /* |
8103 | * Mixing clocks in the same buffer is trouble you don't need. | |
8104 | */ | |
8105 | if (output_event->clock != event->clock) | |
8106 | goto out; | |
8107 | ||
45bfb2e5 PZ |
8108 | /* |
8109 | * If both events generate aux data, they must be on the same PMU | |
8110 | */ | |
8111 | if (has_aux(event) && has_aux(output_event) && | |
8112 | event->pmu != output_event->pmu) | |
8113 | goto out; | |
8114 | ||
a4be7c27 | 8115 | set: |
cdd6c482 | 8116 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8117 | /* Can't redirect output if we've got an active mmap() */ |
8118 | if (atomic_read(&event->mmap_count)) | |
8119 | goto unlock; | |
a4be7c27 | 8120 | |
ac9721f3 | 8121 | if (output_event) { |
76369139 FW |
8122 | /* get the rb we want to redirect to */ |
8123 | rb = ring_buffer_get(output_event); | |
8124 | if (!rb) | |
ac9721f3 | 8125 | goto unlock; |
a4be7c27 PZ |
8126 | } |
8127 | ||
b69cf536 | 8128 | ring_buffer_attach(event, rb); |
9bb5d40c | 8129 | |
a4be7c27 | 8130 | ret = 0; |
ac9721f3 PZ |
8131 | unlock: |
8132 | mutex_unlock(&event->mmap_mutex); | |
8133 | ||
a4be7c27 | 8134 | out: |
a4be7c27 PZ |
8135 | return ret; |
8136 | } | |
8137 | ||
f63a8daa PZ |
8138 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8139 | { | |
8140 | if (b < a) | |
8141 | swap(a, b); | |
8142 | ||
8143 | mutex_lock(a); | |
8144 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8145 | } | |
8146 | ||
34f43927 PZ |
8147 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8148 | { | |
8149 | bool nmi_safe = false; | |
8150 | ||
8151 | switch (clk_id) { | |
8152 | case CLOCK_MONOTONIC: | |
8153 | event->clock = &ktime_get_mono_fast_ns; | |
8154 | nmi_safe = true; | |
8155 | break; | |
8156 | ||
8157 | case CLOCK_MONOTONIC_RAW: | |
8158 | event->clock = &ktime_get_raw_fast_ns; | |
8159 | nmi_safe = true; | |
8160 | break; | |
8161 | ||
8162 | case CLOCK_REALTIME: | |
8163 | event->clock = &ktime_get_real_ns; | |
8164 | break; | |
8165 | ||
8166 | case CLOCK_BOOTTIME: | |
8167 | event->clock = &ktime_get_boot_ns; | |
8168 | break; | |
8169 | ||
8170 | case CLOCK_TAI: | |
8171 | event->clock = &ktime_get_tai_ns; | |
8172 | break; | |
8173 | ||
8174 | default: | |
8175 | return -EINVAL; | |
8176 | } | |
8177 | ||
8178 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8179 | return -EINVAL; | |
8180 | ||
8181 | return 0; | |
8182 | } | |
8183 | ||
0793a61d | 8184 | /** |
cdd6c482 | 8185 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8186 | * |
cdd6c482 | 8187 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8188 | * @pid: target pid |
9f66a381 | 8189 | * @cpu: target cpu |
cdd6c482 | 8190 | * @group_fd: group leader event fd |
0793a61d | 8191 | */ |
cdd6c482 IM |
8192 | SYSCALL_DEFINE5(perf_event_open, |
8193 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8194 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8195 | { |
b04243ef PZ |
8196 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8197 | struct perf_event *event, *sibling; | |
cdd6c482 | 8198 | struct perf_event_attr attr; |
f63a8daa | 8199 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8200 | struct file *event_file = NULL; |
2903ff01 | 8201 | struct fd group = {NULL, 0}; |
38a81da2 | 8202 | struct task_struct *task = NULL; |
89a1e187 | 8203 | struct pmu *pmu; |
ea635c64 | 8204 | int event_fd; |
b04243ef | 8205 | int move_group = 0; |
dc86cabe | 8206 | int err; |
a21b0b35 | 8207 | int f_flags = O_RDWR; |
79dff51e | 8208 | int cgroup_fd = -1; |
0793a61d | 8209 | |
2743a5b0 | 8210 | /* for future expandability... */ |
e5d1367f | 8211 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8212 | return -EINVAL; |
8213 | ||
dc86cabe IM |
8214 | err = perf_copy_attr(attr_uptr, &attr); |
8215 | if (err) | |
8216 | return err; | |
eab656ae | 8217 | |
0764771d PZ |
8218 | if (!attr.exclude_kernel) { |
8219 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8220 | return -EACCES; | |
8221 | } | |
8222 | ||
df58ab24 | 8223 | if (attr.freq) { |
cdd6c482 | 8224 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8225 | return -EINVAL; |
0819b2e3 PZ |
8226 | } else { |
8227 | if (attr.sample_period & (1ULL << 63)) | |
8228 | return -EINVAL; | |
df58ab24 PZ |
8229 | } |
8230 | ||
e5d1367f SE |
8231 | /* |
8232 | * In cgroup mode, the pid argument is used to pass the fd | |
8233 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8234 | * designates the cpu on which to monitor threads from that | |
8235 | * cgroup. | |
8236 | */ | |
8237 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8238 | return -EINVAL; | |
8239 | ||
a21b0b35 YD |
8240 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8241 | f_flags |= O_CLOEXEC; | |
8242 | ||
8243 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8244 | if (event_fd < 0) |
8245 | return event_fd; | |
8246 | ||
ac9721f3 | 8247 | if (group_fd != -1) { |
2903ff01 AV |
8248 | err = perf_fget_light(group_fd, &group); |
8249 | if (err) | |
d14b12d7 | 8250 | goto err_fd; |
2903ff01 | 8251 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8252 | if (flags & PERF_FLAG_FD_OUTPUT) |
8253 | output_event = group_leader; | |
8254 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8255 | group_leader = NULL; | |
8256 | } | |
8257 | ||
e5d1367f | 8258 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8259 | task = find_lively_task_by_vpid(pid); |
8260 | if (IS_ERR(task)) { | |
8261 | err = PTR_ERR(task); | |
8262 | goto err_group_fd; | |
8263 | } | |
8264 | } | |
8265 | ||
1f4ee503 PZ |
8266 | if (task && group_leader && |
8267 | group_leader->attr.inherit != attr.inherit) { | |
8268 | err = -EINVAL; | |
8269 | goto err_task; | |
8270 | } | |
8271 | ||
fbfc623f YZ |
8272 | get_online_cpus(); |
8273 | ||
79dff51e MF |
8274 | if (flags & PERF_FLAG_PID_CGROUP) |
8275 | cgroup_fd = pid; | |
8276 | ||
4dc0da86 | 8277 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8278 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8279 | if (IS_ERR(event)) { |
8280 | err = PTR_ERR(event); | |
1f4ee503 | 8281 | goto err_cpus; |
d14b12d7 SE |
8282 | } |
8283 | ||
53b25335 VW |
8284 | if (is_sampling_event(event)) { |
8285 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8286 | err = -ENOTSUPP; | |
8287 | goto err_alloc; | |
8288 | } | |
8289 | } | |
8290 | ||
766d6c07 FW |
8291 | account_event(event); |
8292 | ||
89a1e187 PZ |
8293 | /* |
8294 | * Special case software events and allow them to be part of | |
8295 | * any hardware group. | |
8296 | */ | |
8297 | pmu = event->pmu; | |
b04243ef | 8298 | |
34f43927 PZ |
8299 | if (attr.use_clockid) { |
8300 | err = perf_event_set_clock(event, attr.clockid); | |
8301 | if (err) | |
8302 | goto err_alloc; | |
8303 | } | |
8304 | ||
b04243ef PZ |
8305 | if (group_leader && |
8306 | (is_software_event(event) != is_software_event(group_leader))) { | |
8307 | if (is_software_event(event)) { | |
8308 | /* | |
8309 | * If event and group_leader are not both a software | |
8310 | * event, and event is, then group leader is not. | |
8311 | * | |
8312 | * Allow the addition of software events to !software | |
8313 | * groups, this is safe because software events never | |
8314 | * fail to schedule. | |
8315 | */ | |
8316 | pmu = group_leader->pmu; | |
8317 | } else if (is_software_event(group_leader) && | |
8318 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8319 | /* | |
8320 | * In case the group is a pure software group, and we | |
8321 | * try to add a hardware event, move the whole group to | |
8322 | * the hardware context. | |
8323 | */ | |
8324 | move_group = 1; | |
8325 | } | |
8326 | } | |
89a1e187 PZ |
8327 | |
8328 | /* | |
8329 | * Get the target context (task or percpu): | |
8330 | */ | |
4af57ef2 | 8331 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8332 | if (IS_ERR(ctx)) { |
8333 | err = PTR_ERR(ctx); | |
c6be5a5c | 8334 | goto err_alloc; |
89a1e187 PZ |
8335 | } |
8336 | ||
bed5b25a AS |
8337 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8338 | err = -EBUSY; | |
8339 | goto err_context; | |
8340 | } | |
8341 | ||
fd1edb3a PZ |
8342 | if (task) { |
8343 | put_task_struct(task); | |
8344 | task = NULL; | |
8345 | } | |
8346 | ||
ccff286d | 8347 | /* |
cdd6c482 | 8348 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8349 | */ |
ac9721f3 | 8350 | if (group_leader) { |
dc86cabe | 8351 | err = -EINVAL; |
04289bb9 | 8352 | |
04289bb9 | 8353 | /* |
ccff286d IM |
8354 | * Do not allow a recursive hierarchy (this new sibling |
8355 | * becoming part of another group-sibling): | |
8356 | */ | |
8357 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8358 | goto err_context; |
34f43927 PZ |
8359 | |
8360 | /* All events in a group should have the same clock */ | |
8361 | if (group_leader->clock != event->clock) | |
8362 | goto err_context; | |
8363 | ||
ccff286d IM |
8364 | /* |
8365 | * Do not allow to attach to a group in a different | |
8366 | * task or CPU context: | |
04289bb9 | 8367 | */ |
b04243ef | 8368 | if (move_group) { |
c3c87e77 PZ |
8369 | /* |
8370 | * Make sure we're both on the same task, or both | |
8371 | * per-cpu events. | |
8372 | */ | |
8373 | if (group_leader->ctx->task != ctx->task) | |
8374 | goto err_context; | |
8375 | ||
8376 | /* | |
8377 | * Make sure we're both events for the same CPU; | |
8378 | * grouping events for different CPUs is broken; since | |
8379 | * you can never concurrently schedule them anyhow. | |
8380 | */ | |
8381 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8382 | goto err_context; |
8383 | } else { | |
8384 | if (group_leader->ctx != ctx) | |
8385 | goto err_context; | |
8386 | } | |
8387 | ||
3b6f9e5c PM |
8388 | /* |
8389 | * Only a group leader can be exclusive or pinned | |
8390 | */ | |
0d48696f | 8391 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8392 | goto err_context; |
ac9721f3 PZ |
8393 | } |
8394 | ||
8395 | if (output_event) { | |
8396 | err = perf_event_set_output(event, output_event); | |
8397 | if (err) | |
c3f00c70 | 8398 | goto err_context; |
ac9721f3 | 8399 | } |
0793a61d | 8400 | |
a21b0b35 YD |
8401 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8402 | f_flags); | |
ea635c64 AV |
8403 | if (IS_ERR(event_file)) { |
8404 | err = PTR_ERR(event_file); | |
c3f00c70 | 8405 | goto err_context; |
ea635c64 | 8406 | } |
9b51f66d | 8407 | |
b04243ef | 8408 | if (move_group) { |
f63a8daa | 8409 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8410 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8411 | } else { | |
8412 | mutex_lock(&ctx->mutex); | |
8413 | } | |
8414 | ||
a723968c PZ |
8415 | if (!perf_event_validate_size(event)) { |
8416 | err = -E2BIG; | |
8417 | goto err_locked; | |
8418 | } | |
8419 | ||
f55fc2a5 PZ |
8420 | /* |
8421 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8422 | * because we need to serialize with concurrent event creation. | |
8423 | */ | |
8424 | if (!exclusive_event_installable(event, ctx)) { | |
8425 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8426 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8427 | |
f55fc2a5 PZ |
8428 | err = -EBUSY; |
8429 | goto err_locked; | |
8430 | } | |
f63a8daa | 8431 | |
f55fc2a5 PZ |
8432 | WARN_ON_ONCE(ctx->parent_ctx); |
8433 | ||
8434 | if (move_group) { | |
f63a8daa PZ |
8435 | /* |
8436 | * See perf_event_ctx_lock() for comments on the details | |
8437 | * of swizzling perf_event::ctx. | |
8438 | */ | |
46ce0fe9 | 8439 | perf_remove_from_context(group_leader, false); |
0231bb53 | 8440 | |
b04243ef PZ |
8441 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8442 | group_entry) { | |
46ce0fe9 | 8443 | perf_remove_from_context(sibling, false); |
b04243ef PZ |
8444 | put_ctx(gctx); |
8445 | } | |
b04243ef | 8446 | |
f63a8daa PZ |
8447 | /* |
8448 | * Wait for everybody to stop referencing the events through | |
8449 | * the old lists, before installing it on new lists. | |
8450 | */ | |
0cda4c02 | 8451 | synchronize_rcu(); |
f63a8daa | 8452 | |
8f95b435 PZI |
8453 | /* |
8454 | * Install the group siblings before the group leader. | |
8455 | * | |
8456 | * Because a group leader will try and install the entire group | |
8457 | * (through the sibling list, which is still in-tact), we can | |
8458 | * end up with siblings installed in the wrong context. | |
8459 | * | |
8460 | * By installing siblings first we NO-OP because they're not | |
8461 | * reachable through the group lists. | |
8462 | */ | |
b04243ef PZ |
8463 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8464 | group_entry) { | |
8f95b435 | 8465 | perf_event__state_init(sibling); |
9fc81d87 | 8466 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8467 | get_ctx(ctx); |
8468 | } | |
8f95b435 PZI |
8469 | |
8470 | /* | |
8471 | * Removing from the context ends up with disabled | |
8472 | * event. What we want here is event in the initial | |
8473 | * startup state, ready to be add into new context. | |
8474 | */ | |
8475 | perf_event__state_init(group_leader); | |
8476 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8477 | get_ctx(ctx); | |
b04243ef | 8478 | |
f55fc2a5 PZ |
8479 | /* |
8480 | * Now that all events are installed in @ctx, nothing | |
8481 | * references @gctx anymore, so drop the last reference we have | |
8482 | * on it. | |
8483 | */ | |
8484 | put_ctx(gctx); | |
bed5b25a AS |
8485 | } |
8486 | ||
f73e22ab PZ |
8487 | /* |
8488 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8489 | * that we're serialized against further additions and before | |
8490 | * perf_install_in_context() which is the point the event is active and | |
8491 | * can use these values. | |
8492 | */ | |
8493 | perf_event__header_size(event); | |
8494 | perf_event__id_header_size(event); | |
8495 | ||
e2d37cd2 | 8496 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8497 | perf_unpin_context(ctx); |
f63a8daa | 8498 | |
f55fc2a5 | 8499 | if (move_group) |
f63a8daa | 8500 | mutex_unlock(&gctx->mutex); |
d859e29f | 8501 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8502 | |
fbfc623f YZ |
8503 | put_online_cpus(); |
8504 | ||
cdd6c482 | 8505 | event->owner = current; |
8882135b | 8506 | |
cdd6c482 IM |
8507 | mutex_lock(¤t->perf_event_mutex); |
8508 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8509 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8510 | |
8a49542c PZ |
8511 | /* |
8512 | * Drop the reference on the group_event after placing the | |
8513 | * new event on the sibling_list. This ensures destruction | |
8514 | * of the group leader will find the pointer to itself in | |
8515 | * perf_group_detach(). | |
8516 | */ | |
2903ff01 | 8517 | fdput(group); |
ea635c64 AV |
8518 | fd_install(event_fd, event_file); |
8519 | return event_fd; | |
0793a61d | 8520 | |
f55fc2a5 PZ |
8521 | err_locked: |
8522 | if (move_group) | |
8523 | mutex_unlock(&gctx->mutex); | |
8524 | mutex_unlock(&ctx->mutex); | |
8525 | /* err_file: */ | |
8526 | fput(event_file); | |
c3f00c70 | 8527 | err_context: |
fe4b04fa | 8528 | perf_unpin_context(ctx); |
ea635c64 | 8529 | put_ctx(ctx); |
c6be5a5c | 8530 | err_alloc: |
ea635c64 | 8531 | free_event(event); |
1f4ee503 | 8532 | err_cpus: |
fbfc623f | 8533 | put_online_cpus(); |
1f4ee503 | 8534 | err_task: |
e7d0bc04 PZ |
8535 | if (task) |
8536 | put_task_struct(task); | |
89a1e187 | 8537 | err_group_fd: |
2903ff01 | 8538 | fdput(group); |
ea635c64 AV |
8539 | err_fd: |
8540 | put_unused_fd(event_fd); | |
dc86cabe | 8541 | return err; |
0793a61d TG |
8542 | } |
8543 | ||
fb0459d7 AV |
8544 | /** |
8545 | * perf_event_create_kernel_counter | |
8546 | * | |
8547 | * @attr: attributes of the counter to create | |
8548 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8549 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8550 | */ |
8551 | struct perf_event * | |
8552 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8553 | struct task_struct *task, |
4dc0da86 AK |
8554 | perf_overflow_handler_t overflow_handler, |
8555 | void *context) | |
fb0459d7 | 8556 | { |
fb0459d7 | 8557 | struct perf_event_context *ctx; |
c3f00c70 | 8558 | struct perf_event *event; |
fb0459d7 | 8559 | int err; |
d859e29f | 8560 | |
fb0459d7 AV |
8561 | /* |
8562 | * Get the target context (task or percpu): | |
8563 | */ | |
d859e29f | 8564 | |
4dc0da86 | 8565 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8566 | overflow_handler, context, -1); |
c3f00c70 PZ |
8567 | if (IS_ERR(event)) { |
8568 | err = PTR_ERR(event); | |
8569 | goto err; | |
8570 | } | |
d859e29f | 8571 | |
f8697762 JO |
8572 | /* Mark owner so we could distinguish it from user events. */ |
8573 | event->owner = EVENT_OWNER_KERNEL; | |
8574 | ||
766d6c07 FW |
8575 | account_event(event); |
8576 | ||
4af57ef2 | 8577 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8578 | if (IS_ERR(ctx)) { |
8579 | err = PTR_ERR(ctx); | |
c3f00c70 | 8580 | goto err_free; |
d859e29f | 8581 | } |
fb0459d7 | 8582 | |
fb0459d7 AV |
8583 | WARN_ON_ONCE(ctx->parent_ctx); |
8584 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8585 | if (!exclusive_event_installable(event, ctx)) { |
8586 | mutex_unlock(&ctx->mutex); | |
8587 | perf_unpin_context(ctx); | |
8588 | put_ctx(ctx); | |
8589 | err = -EBUSY; | |
8590 | goto err_free; | |
8591 | } | |
8592 | ||
fb0459d7 | 8593 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8594 | perf_unpin_context(ctx); |
fb0459d7 AV |
8595 | mutex_unlock(&ctx->mutex); |
8596 | ||
fb0459d7 AV |
8597 | return event; |
8598 | ||
c3f00c70 PZ |
8599 | err_free: |
8600 | free_event(event); | |
8601 | err: | |
c6567f64 | 8602 | return ERR_PTR(err); |
9b51f66d | 8603 | } |
fb0459d7 | 8604 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8605 | |
0cda4c02 YZ |
8606 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8607 | { | |
8608 | struct perf_event_context *src_ctx; | |
8609 | struct perf_event_context *dst_ctx; | |
8610 | struct perf_event *event, *tmp; | |
8611 | LIST_HEAD(events); | |
8612 | ||
8613 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8614 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8615 | ||
f63a8daa PZ |
8616 | /* |
8617 | * See perf_event_ctx_lock() for comments on the details | |
8618 | * of swizzling perf_event::ctx. | |
8619 | */ | |
8620 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8621 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8622 | event_entry) { | |
46ce0fe9 | 8623 | perf_remove_from_context(event, false); |
9a545de0 | 8624 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8625 | put_ctx(src_ctx); |
9886167d | 8626 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8627 | } |
0cda4c02 | 8628 | |
8f95b435 PZI |
8629 | /* |
8630 | * Wait for the events to quiesce before re-instating them. | |
8631 | */ | |
0cda4c02 YZ |
8632 | synchronize_rcu(); |
8633 | ||
8f95b435 PZI |
8634 | /* |
8635 | * Re-instate events in 2 passes. | |
8636 | * | |
8637 | * Skip over group leaders and only install siblings on this first | |
8638 | * pass, siblings will not get enabled without a leader, however a | |
8639 | * leader will enable its siblings, even if those are still on the old | |
8640 | * context. | |
8641 | */ | |
8642 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8643 | if (event->group_leader == event) | |
8644 | continue; | |
8645 | ||
8646 | list_del(&event->migrate_entry); | |
8647 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8648 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8649 | account_event_cpu(event, dst_cpu); | |
8650 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8651 | get_ctx(dst_ctx); | |
8652 | } | |
8653 | ||
8654 | /* | |
8655 | * Once all the siblings are setup properly, install the group leaders | |
8656 | * to make it go. | |
8657 | */ | |
9886167d PZ |
8658 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8659 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8660 | if (event->state >= PERF_EVENT_STATE_OFF) |
8661 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8662 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8663 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8664 | get_ctx(dst_ctx); | |
8665 | } | |
8666 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8667 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8668 | } |
8669 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8670 | ||
cdd6c482 | 8671 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8672 | struct task_struct *child) |
d859e29f | 8673 | { |
cdd6c482 | 8674 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8675 | u64 child_val; |
d859e29f | 8676 | |
cdd6c482 IM |
8677 | if (child_event->attr.inherit_stat) |
8678 | perf_event_read_event(child_event, child); | |
38b200d6 | 8679 | |
b5e58793 | 8680 | child_val = perf_event_count(child_event); |
d859e29f PM |
8681 | |
8682 | /* | |
8683 | * Add back the child's count to the parent's count: | |
8684 | */ | |
a6e6dea6 | 8685 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8686 | atomic64_add(child_event->total_time_enabled, |
8687 | &parent_event->child_total_time_enabled); | |
8688 | atomic64_add(child_event->total_time_running, | |
8689 | &parent_event->child_total_time_running); | |
d859e29f PM |
8690 | |
8691 | /* | |
cdd6c482 | 8692 | * Remove this event from the parent's list |
d859e29f | 8693 | */ |
cdd6c482 IM |
8694 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
8695 | mutex_lock(&parent_event->child_mutex); | |
8696 | list_del_init(&child_event->child_list); | |
8697 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f | 8698 | |
dc633982 JO |
8699 | /* |
8700 | * Make sure user/parent get notified, that we just | |
8701 | * lost one event. | |
8702 | */ | |
8703 | perf_event_wakeup(parent_event); | |
8704 | ||
d859e29f | 8705 | /* |
cdd6c482 | 8706 | * Release the parent event, if this was the last |
d859e29f PM |
8707 | * reference to it. |
8708 | */ | |
a6fa941d | 8709 | put_event(parent_event); |
d859e29f PM |
8710 | } |
8711 | ||
9b51f66d | 8712 | static void |
cdd6c482 IM |
8713 | __perf_event_exit_task(struct perf_event *child_event, |
8714 | struct perf_event_context *child_ctx, | |
38b200d6 | 8715 | struct task_struct *child) |
9b51f66d | 8716 | { |
1903d50c PZ |
8717 | /* |
8718 | * Do not destroy the 'original' grouping; because of the context | |
8719 | * switch optimization the original events could've ended up in a | |
8720 | * random child task. | |
8721 | * | |
8722 | * If we were to destroy the original group, all group related | |
8723 | * operations would cease to function properly after this random | |
8724 | * child dies. | |
8725 | * | |
8726 | * Do destroy all inherited groups, we don't care about those | |
8727 | * and being thorough is better. | |
8728 | */ | |
32132a3d PZ |
8729 | raw_spin_lock_irq(&child_ctx->lock); |
8730 | WARN_ON_ONCE(child_ctx->is_active); | |
8731 | ||
8732 | if (!!child_event->parent) | |
8733 | perf_group_detach(child_event); | |
8734 | list_del_event(child_event, child_ctx); | |
8735 | raw_spin_unlock_irq(&child_ctx->lock); | |
0cc0c027 | 8736 | |
9b51f66d | 8737 | /* |
38b435b1 | 8738 | * It can happen that the parent exits first, and has events |
9b51f66d | 8739 | * that are still around due to the child reference. These |
38b435b1 | 8740 | * events need to be zapped. |
9b51f66d | 8741 | */ |
38b435b1 | 8742 | if (child_event->parent) { |
cdd6c482 IM |
8743 | sync_child_event(child_event, child); |
8744 | free_event(child_event); | |
179033b3 JO |
8745 | } else { |
8746 | child_event->state = PERF_EVENT_STATE_EXIT; | |
8747 | perf_event_wakeup(child_event); | |
4bcf349a | 8748 | } |
9b51f66d IM |
8749 | } |
8750 | ||
8dc85d54 | 8751 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8752 | { |
ebf905fc | 8753 | struct perf_event *child_event, *next; |
211de6eb | 8754 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
9b51f66d | 8755 | |
4e93ad60 | 8756 | if (likely(!child->perf_event_ctxp[ctxn])) |
9b51f66d IM |
8757 | return; |
8758 | ||
32132a3d PZ |
8759 | local_irq_disable(); |
8760 | WARN_ON_ONCE(child != current); | |
ad3a37de PM |
8761 | /* |
8762 | * We can't reschedule here because interrupts are disabled, | |
32132a3d | 8763 | * and child must be current. |
ad3a37de | 8764 | */ |
806839b2 | 8765 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
8766 | |
8767 | /* | |
8768 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 8769 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
8770 | * incremented the context's refcount before we do put_ctx below. |
8771 | */ | |
e625cce1 | 8772 | raw_spin_lock(&child_ctx->lock); |
3e349507 | 8773 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
8dc85d54 | 8774 | child->perf_event_ctxp[ctxn] = NULL; |
4a1c0f26 | 8775 | |
71a851b4 PZ |
8776 | /* |
8777 | * If this context is a clone; unclone it so it can't get | |
8778 | * swapped to another process while we're removing all | |
cdd6c482 | 8779 | * the events from it. |
71a851b4 | 8780 | */ |
211de6eb | 8781 | clone_ctx = unclone_ctx(child_ctx); |
5e942bb3 | 8782 | update_context_time(child_ctx); |
32132a3d | 8783 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8784 | |
211de6eb PZ |
8785 | if (clone_ctx) |
8786 | put_ctx(clone_ctx); | |
4a1c0f26 | 8787 | |
9f498cc5 | 8788 | /* |
cdd6c482 IM |
8789 | * Report the task dead after unscheduling the events so that we |
8790 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8791 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8792 | */ |
cdd6c482 | 8793 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8794 | |
66fff224 PZ |
8795 | /* |
8796 | * We can recurse on the same lock type through: | |
8797 | * | |
cdd6c482 IM |
8798 | * __perf_event_exit_task() |
8799 | * sync_child_event() | |
a6fa941d AV |
8800 | * put_event() |
8801 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
8802 | * |
8803 | * But since its the parent context it won't be the same instance. | |
8804 | */ | |
a0507c84 | 8805 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 8806 | |
ebf905fc | 8807 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
cdd6c482 | 8808 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 | 8809 | |
a63eaf34 PM |
8810 | mutex_unlock(&child_ctx->mutex); |
8811 | ||
8812 | put_ctx(child_ctx); | |
9b51f66d IM |
8813 | } |
8814 | ||
8dc85d54 PZ |
8815 | /* |
8816 | * When a child task exits, feed back event values to parent events. | |
8817 | */ | |
8818 | void perf_event_exit_task(struct task_struct *child) | |
8819 | { | |
8882135b | 8820 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8821 | int ctxn; |
8822 | ||
8882135b PZ |
8823 | mutex_lock(&child->perf_event_mutex); |
8824 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8825 | owner_entry) { | |
8826 | list_del_init(&event->owner_entry); | |
8827 | ||
8828 | /* | |
8829 | * Ensure the list deletion is visible before we clear | |
8830 | * the owner, closes a race against perf_release() where | |
8831 | * we need to serialize on the owner->perf_event_mutex. | |
8832 | */ | |
8833 | smp_wmb(); | |
8834 | event->owner = NULL; | |
8835 | } | |
8836 | mutex_unlock(&child->perf_event_mutex); | |
8837 | ||
8dc85d54 PZ |
8838 | for_each_task_context_nr(ctxn) |
8839 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8840 | |
8841 | /* | |
8842 | * The perf_event_exit_task_context calls perf_event_task | |
8843 | * with child's task_ctx, which generates EXIT events for | |
8844 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8845 | * At this point we need to send EXIT events to cpu contexts. | |
8846 | */ | |
8847 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8848 | } |
8849 | ||
889ff015 FW |
8850 | static void perf_free_event(struct perf_event *event, |
8851 | struct perf_event_context *ctx) | |
8852 | { | |
8853 | struct perf_event *parent = event->parent; | |
8854 | ||
8855 | if (WARN_ON_ONCE(!parent)) | |
8856 | return; | |
8857 | ||
8858 | mutex_lock(&parent->child_mutex); | |
8859 | list_del_init(&event->child_list); | |
8860 | mutex_unlock(&parent->child_mutex); | |
8861 | ||
a6fa941d | 8862 | put_event(parent); |
889ff015 | 8863 | |
652884fe | 8864 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8865 | perf_group_detach(event); |
889ff015 | 8866 | list_del_event(event, ctx); |
652884fe | 8867 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8868 | free_event(event); |
8869 | } | |
8870 | ||
bbbee908 | 8871 | /* |
652884fe | 8872 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8873 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8874 | * |
8875 | * Not all locks are strictly required, but take them anyway to be nice and | |
8876 | * help out with the lockdep assertions. | |
bbbee908 | 8877 | */ |
cdd6c482 | 8878 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8879 | { |
8dc85d54 | 8880 | struct perf_event_context *ctx; |
cdd6c482 | 8881 | struct perf_event *event, *tmp; |
8dc85d54 | 8882 | int ctxn; |
bbbee908 | 8883 | |
8dc85d54 PZ |
8884 | for_each_task_context_nr(ctxn) { |
8885 | ctx = task->perf_event_ctxp[ctxn]; | |
8886 | if (!ctx) | |
8887 | continue; | |
bbbee908 | 8888 | |
8dc85d54 | 8889 | mutex_lock(&ctx->mutex); |
bbbee908 | 8890 | again: |
8dc85d54 PZ |
8891 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8892 | group_entry) | |
8893 | perf_free_event(event, ctx); | |
bbbee908 | 8894 | |
8dc85d54 PZ |
8895 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8896 | group_entry) | |
8897 | perf_free_event(event, ctx); | |
bbbee908 | 8898 | |
8dc85d54 PZ |
8899 | if (!list_empty(&ctx->pinned_groups) || |
8900 | !list_empty(&ctx->flexible_groups)) | |
8901 | goto again; | |
bbbee908 | 8902 | |
8dc85d54 | 8903 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8904 | |
8dc85d54 PZ |
8905 | put_ctx(ctx); |
8906 | } | |
889ff015 FW |
8907 | } |
8908 | ||
4e231c79 PZ |
8909 | void perf_event_delayed_put(struct task_struct *task) |
8910 | { | |
8911 | int ctxn; | |
8912 | ||
8913 | for_each_task_context_nr(ctxn) | |
8914 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8915 | } | |
8916 | ||
ffe8690c KX |
8917 | struct perf_event *perf_event_get(unsigned int fd) |
8918 | { | |
8919 | int err; | |
8920 | struct fd f; | |
8921 | struct perf_event *event; | |
8922 | ||
8923 | err = perf_fget_light(fd, &f); | |
8924 | if (err) | |
8925 | return ERR_PTR(err); | |
8926 | ||
8927 | event = f.file->private_data; | |
8928 | atomic_long_inc(&event->refcount); | |
8929 | fdput(f); | |
8930 | ||
8931 | return event; | |
8932 | } | |
8933 | ||
8934 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8935 | { | |
8936 | if (!event) | |
8937 | return ERR_PTR(-EINVAL); | |
8938 | ||
8939 | return &event->attr; | |
8940 | } | |
8941 | ||
97dee4f3 PZ |
8942 | /* |
8943 | * inherit a event from parent task to child task: | |
8944 | */ | |
8945 | static struct perf_event * | |
8946 | inherit_event(struct perf_event *parent_event, | |
8947 | struct task_struct *parent, | |
8948 | struct perf_event_context *parent_ctx, | |
8949 | struct task_struct *child, | |
8950 | struct perf_event *group_leader, | |
8951 | struct perf_event_context *child_ctx) | |
8952 | { | |
1929def9 | 8953 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8954 | struct perf_event *child_event; |
cee010ec | 8955 | unsigned long flags; |
97dee4f3 PZ |
8956 | |
8957 | /* | |
8958 | * Instead of creating recursive hierarchies of events, | |
8959 | * we link inherited events back to the original parent, | |
8960 | * which has a filp for sure, which we use as the reference | |
8961 | * count: | |
8962 | */ | |
8963 | if (parent_event->parent) | |
8964 | parent_event = parent_event->parent; | |
8965 | ||
8966 | child_event = perf_event_alloc(&parent_event->attr, | |
8967 | parent_event->cpu, | |
d580ff86 | 8968 | child, |
97dee4f3 | 8969 | group_leader, parent_event, |
79dff51e | 8970 | NULL, NULL, -1); |
97dee4f3 PZ |
8971 | if (IS_ERR(child_event)) |
8972 | return child_event; | |
a6fa941d | 8973 | |
fadfe7be JO |
8974 | if (is_orphaned_event(parent_event) || |
8975 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
a6fa941d AV |
8976 | free_event(child_event); |
8977 | return NULL; | |
8978 | } | |
8979 | ||
97dee4f3 PZ |
8980 | get_ctx(child_ctx); |
8981 | ||
8982 | /* | |
8983 | * Make the child state follow the state of the parent event, | |
8984 | * not its attr.disabled bit. We hold the parent's mutex, | |
8985 | * so we won't race with perf_event_{en, dis}able_family. | |
8986 | */ | |
1929def9 | 8987 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8988 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8989 | else | |
8990 | child_event->state = PERF_EVENT_STATE_OFF; | |
8991 | ||
8992 | if (parent_event->attr.freq) { | |
8993 | u64 sample_period = parent_event->hw.sample_period; | |
8994 | struct hw_perf_event *hwc = &child_event->hw; | |
8995 | ||
8996 | hwc->sample_period = sample_period; | |
8997 | hwc->last_period = sample_period; | |
8998 | ||
8999 | local64_set(&hwc->period_left, sample_period); | |
9000 | } | |
9001 | ||
9002 | child_event->ctx = child_ctx; | |
9003 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9004 | child_event->overflow_handler_context |
9005 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9006 | |
614b6780 TG |
9007 | /* |
9008 | * Precalculate sample_data sizes | |
9009 | */ | |
9010 | perf_event__header_size(child_event); | |
6844c09d | 9011 | perf_event__id_header_size(child_event); |
614b6780 | 9012 | |
97dee4f3 PZ |
9013 | /* |
9014 | * Link it up in the child's context: | |
9015 | */ | |
cee010ec | 9016 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9017 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9018 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9019 | |
97dee4f3 PZ |
9020 | /* |
9021 | * Link this into the parent event's child list | |
9022 | */ | |
9023 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
9024 | mutex_lock(&parent_event->child_mutex); | |
9025 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
9026 | mutex_unlock(&parent_event->child_mutex); | |
9027 | ||
9028 | return child_event; | |
9029 | } | |
9030 | ||
9031 | static int inherit_group(struct perf_event *parent_event, | |
9032 | struct task_struct *parent, | |
9033 | struct perf_event_context *parent_ctx, | |
9034 | struct task_struct *child, | |
9035 | struct perf_event_context *child_ctx) | |
9036 | { | |
9037 | struct perf_event *leader; | |
9038 | struct perf_event *sub; | |
9039 | struct perf_event *child_ctr; | |
9040 | ||
9041 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9042 | child, NULL, child_ctx); | |
9043 | if (IS_ERR(leader)) | |
9044 | return PTR_ERR(leader); | |
9045 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9046 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9047 | child, leader, child_ctx); | |
9048 | if (IS_ERR(child_ctr)) | |
9049 | return PTR_ERR(child_ctr); | |
9050 | } | |
9051 | return 0; | |
889ff015 FW |
9052 | } |
9053 | ||
9054 | static int | |
9055 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9056 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9057 | struct task_struct *child, int ctxn, |
889ff015 FW |
9058 | int *inherited_all) |
9059 | { | |
9060 | int ret; | |
8dc85d54 | 9061 | struct perf_event_context *child_ctx; |
889ff015 FW |
9062 | |
9063 | if (!event->attr.inherit) { | |
9064 | *inherited_all = 0; | |
9065 | return 0; | |
bbbee908 PZ |
9066 | } |
9067 | ||
fe4b04fa | 9068 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9069 | if (!child_ctx) { |
9070 | /* | |
9071 | * This is executed from the parent task context, so | |
9072 | * inherit events that have been marked for cloning. | |
9073 | * First allocate and initialize a context for the | |
9074 | * child. | |
9075 | */ | |
bbbee908 | 9076 | |
734df5ab | 9077 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9078 | if (!child_ctx) |
9079 | return -ENOMEM; | |
bbbee908 | 9080 | |
8dc85d54 | 9081 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9082 | } |
9083 | ||
9084 | ret = inherit_group(event, parent, parent_ctx, | |
9085 | child, child_ctx); | |
9086 | ||
9087 | if (ret) | |
9088 | *inherited_all = 0; | |
9089 | ||
9090 | return ret; | |
bbbee908 PZ |
9091 | } |
9092 | ||
9b51f66d | 9093 | /* |
cdd6c482 | 9094 | * Initialize the perf_event context in task_struct |
9b51f66d | 9095 | */ |
985c8dcb | 9096 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9097 | { |
889ff015 | 9098 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9099 | struct perf_event_context *cloned_ctx; |
9100 | struct perf_event *event; | |
9b51f66d | 9101 | struct task_struct *parent = current; |
564c2b21 | 9102 | int inherited_all = 1; |
dddd3379 | 9103 | unsigned long flags; |
6ab423e0 | 9104 | int ret = 0; |
9b51f66d | 9105 | |
8dc85d54 | 9106 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9107 | return 0; |
9108 | ||
ad3a37de | 9109 | /* |
25346b93 PM |
9110 | * If the parent's context is a clone, pin it so it won't get |
9111 | * swapped under us. | |
ad3a37de | 9112 | */ |
8dc85d54 | 9113 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9114 | if (!parent_ctx) |
9115 | return 0; | |
25346b93 | 9116 | |
ad3a37de PM |
9117 | /* |
9118 | * No need to check if parent_ctx != NULL here; since we saw | |
9119 | * it non-NULL earlier, the only reason for it to become NULL | |
9120 | * is if we exit, and since we're currently in the middle of | |
9121 | * a fork we can't be exiting at the same time. | |
9122 | */ | |
ad3a37de | 9123 | |
9b51f66d IM |
9124 | /* |
9125 | * Lock the parent list. No need to lock the child - not PID | |
9126 | * hashed yet and not running, so nobody can access it. | |
9127 | */ | |
d859e29f | 9128 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9129 | |
9130 | /* | |
9131 | * We dont have to disable NMIs - we are only looking at | |
9132 | * the list, not manipulating it: | |
9133 | */ | |
889ff015 | 9134 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9135 | ret = inherit_task_group(event, parent, parent_ctx, |
9136 | child, ctxn, &inherited_all); | |
889ff015 FW |
9137 | if (ret) |
9138 | break; | |
9139 | } | |
b93f7978 | 9140 | |
dddd3379 TG |
9141 | /* |
9142 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9143 | * to allocations, but we need to prevent rotation because | |
9144 | * rotate_ctx() will change the list from interrupt context. | |
9145 | */ | |
9146 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9147 | parent_ctx->rotate_disable = 1; | |
9148 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9149 | ||
889ff015 | 9150 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9151 | ret = inherit_task_group(event, parent, parent_ctx, |
9152 | child, ctxn, &inherited_all); | |
889ff015 | 9153 | if (ret) |
9b51f66d | 9154 | break; |
564c2b21 PM |
9155 | } |
9156 | ||
dddd3379 TG |
9157 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9158 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9159 | |
8dc85d54 | 9160 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9161 | |
05cbaa28 | 9162 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9163 | /* |
9164 | * Mark the child context as a clone of the parent | |
9165 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9166 | * |
9167 | * Note that if the parent is a clone, the holding of | |
9168 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9169 | */ |
c5ed5145 | 9170 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9171 | if (cloned_ctx) { |
9172 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9173 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9174 | } else { |
9175 | child_ctx->parent_ctx = parent_ctx; | |
9176 | child_ctx->parent_gen = parent_ctx->generation; | |
9177 | } | |
9178 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9179 | } |
9180 | ||
c5ed5145 | 9181 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9182 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9183 | |
25346b93 | 9184 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9185 | put_ctx(parent_ctx); |
ad3a37de | 9186 | |
6ab423e0 | 9187 | return ret; |
9b51f66d IM |
9188 | } |
9189 | ||
8dc85d54 PZ |
9190 | /* |
9191 | * Initialize the perf_event context in task_struct | |
9192 | */ | |
9193 | int perf_event_init_task(struct task_struct *child) | |
9194 | { | |
9195 | int ctxn, ret; | |
9196 | ||
8550d7cb ON |
9197 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9198 | mutex_init(&child->perf_event_mutex); | |
9199 | INIT_LIST_HEAD(&child->perf_event_list); | |
9200 | ||
8dc85d54 PZ |
9201 | for_each_task_context_nr(ctxn) { |
9202 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9203 | if (ret) { |
9204 | perf_event_free_task(child); | |
8dc85d54 | 9205 | return ret; |
6c72e350 | 9206 | } |
8dc85d54 PZ |
9207 | } |
9208 | ||
9209 | return 0; | |
9210 | } | |
9211 | ||
220b140b PM |
9212 | static void __init perf_event_init_all_cpus(void) |
9213 | { | |
b28ab83c | 9214 | struct swevent_htable *swhash; |
220b140b | 9215 | int cpu; |
220b140b PM |
9216 | |
9217 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9218 | swhash = &per_cpu(swevent_htable, cpu); |
9219 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9220 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9221 | } |
9222 | } | |
9223 | ||
0db0628d | 9224 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9225 | { |
108b02cf | 9226 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9227 | |
b28ab83c | 9228 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9229 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9230 | struct swevent_hlist *hlist; |
9231 | ||
b28ab83c PZ |
9232 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9233 | WARN_ON(!hlist); | |
9234 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9235 | } |
b28ab83c | 9236 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9237 | } |
9238 | ||
2965faa5 | 9239 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9240 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9241 | { |
226424ee | 9242 | struct remove_event re = { .detach_group = true }; |
108b02cf | 9243 | struct perf_event_context *ctx = __info; |
0793a61d | 9244 | |
e3703f8c | 9245 | rcu_read_lock(); |
46ce0fe9 PZ |
9246 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) |
9247 | __perf_remove_from_context(&re); | |
e3703f8c | 9248 | rcu_read_unlock(); |
0793a61d | 9249 | } |
108b02cf PZ |
9250 | |
9251 | static void perf_event_exit_cpu_context(int cpu) | |
9252 | { | |
9253 | struct perf_event_context *ctx; | |
9254 | struct pmu *pmu; | |
9255 | int idx; | |
9256 | ||
9257 | idx = srcu_read_lock(&pmus_srcu); | |
9258 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9259 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9260 | |
9261 | mutex_lock(&ctx->mutex); | |
9262 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9263 | mutex_unlock(&ctx->mutex); | |
9264 | } | |
9265 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9266 | } |
9267 | ||
cdd6c482 | 9268 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9269 | { |
e3703f8c | 9270 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9271 | } |
9272 | #else | |
cdd6c482 | 9273 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9274 | #endif |
9275 | ||
c277443c PZ |
9276 | static int |
9277 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9278 | { | |
9279 | int cpu; | |
9280 | ||
9281 | for_each_online_cpu(cpu) | |
9282 | perf_event_exit_cpu(cpu); | |
9283 | ||
9284 | return NOTIFY_OK; | |
9285 | } | |
9286 | ||
9287 | /* | |
9288 | * Run the perf reboot notifier at the very last possible moment so that | |
9289 | * the generic watchdog code runs as long as possible. | |
9290 | */ | |
9291 | static struct notifier_block perf_reboot_notifier = { | |
9292 | .notifier_call = perf_reboot, | |
9293 | .priority = INT_MIN, | |
9294 | }; | |
9295 | ||
0db0628d | 9296 | static int |
0793a61d TG |
9297 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9298 | { | |
9299 | unsigned int cpu = (long)hcpu; | |
9300 | ||
4536e4d1 | 9301 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9302 | |
9303 | case CPU_UP_PREPARE: | |
5e11637e | 9304 | case CPU_DOWN_FAILED: |
cdd6c482 | 9305 | perf_event_init_cpu(cpu); |
0793a61d TG |
9306 | break; |
9307 | ||
5e11637e | 9308 | case CPU_UP_CANCELED: |
0793a61d | 9309 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9310 | perf_event_exit_cpu(cpu); |
0793a61d | 9311 | break; |
0793a61d TG |
9312 | default: |
9313 | break; | |
9314 | } | |
9315 | ||
9316 | return NOTIFY_OK; | |
9317 | } | |
9318 | ||
cdd6c482 | 9319 | void __init perf_event_init(void) |
0793a61d | 9320 | { |
3c502e7a JW |
9321 | int ret; |
9322 | ||
2e80a82a PZ |
9323 | idr_init(&pmu_idr); |
9324 | ||
220b140b | 9325 | perf_event_init_all_cpus(); |
b0a873eb | 9326 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9327 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9328 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9329 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9330 | perf_tp_register(); |
9331 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9332 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9333 | |
9334 | ret = init_hw_breakpoint(); | |
9335 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9336 | |
9337 | /* do not patch jump label more than once per second */ | |
9338 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9339 | |
9340 | /* | |
9341 | * Build time assertion that we keep the data_head at the intended | |
9342 | * location. IOW, validation we got the __reserved[] size right. | |
9343 | */ | |
9344 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9345 | != 1024); | |
0793a61d | 9346 | } |
abe43400 | 9347 | |
fd979c01 CS |
9348 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9349 | char *page) | |
9350 | { | |
9351 | struct perf_pmu_events_attr *pmu_attr = | |
9352 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9353 | ||
9354 | if (pmu_attr->event_str) | |
9355 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9356 | ||
9357 | return 0; | |
9358 | } | |
9359 | ||
abe43400 PZ |
9360 | static int __init perf_event_sysfs_init(void) |
9361 | { | |
9362 | struct pmu *pmu; | |
9363 | int ret; | |
9364 | ||
9365 | mutex_lock(&pmus_lock); | |
9366 | ||
9367 | ret = bus_register(&pmu_bus); | |
9368 | if (ret) | |
9369 | goto unlock; | |
9370 | ||
9371 | list_for_each_entry(pmu, &pmus, entry) { | |
9372 | if (!pmu->name || pmu->type < 0) | |
9373 | continue; | |
9374 | ||
9375 | ret = pmu_dev_alloc(pmu); | |
9376 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9377 | } | |
9378 | pmu_bus_running = 1; | |
9379 | ret = 0; | |
9380 | ||
9381 | unlock: | |
9382 | mutex_unlock(&pmus_lock); | |
9383 | ||
9384 | return ret; | |
9385 | } | |
9386 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9387 | |
9388 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9389 | static struct cgroup_subsys_state * |
9390 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9391 | { |
9392 | struct perf_cgroup *jc; | |
e5d1367f | 9393 | |
1b15d055 | 9394 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9395 | if (!jc) |
9396 | return ERR_PTR(-ENOMEM); | |
9397 | ||
e5d1367f SE |
9398 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9399 | if (!jc->info) { | |
9400 | kfree(jc); | |
9401 | return ERR_PTR(-ENOMEM); | |
9402 | } | |
9403 | ||
e5d1367f SE |
9404 | return &jc->css; |
9405 | } | |
9406 | ||
eb95419b | 9407 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9408 | { |
eb95419b TH |
9409 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9410 | ||
e5d1367f SE |
9411 | free_percpu(jc->info); |
9412 | kfree(jc); | |
9413 | } | |
9414 | ||
9415 | static int __perf_cgroup_move(void *info) | |
9416 | { | |
9417 | struct task_struct *task = info; | |
ddaaf4e2 | 9418 | rcu_read_lock(); |
e5d1367f | 9419 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9420 | rcu_read_unlock(); |
e5d1367f SE |
9421 | return 0; |
9422 | } | |
9423 | ||
1f7dd3e5 | 9424 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9425 | { |
bb9d97b6 | 9426 | struct task_struct *task; |
1f7dd3e5 | 9427 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9428 | |
1f7dd3e5 | 9429 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9430 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9431 | } |
9432 | ||
073219e9 | 9433 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9434 | .css_alloc = perf_cgroup_css_alloc, |
9435 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9436 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9437 | }; |
9438 | #endif /* CONFIG_CGROUP_PERF */ |