Commit | Line | Data |
---|---|---|
0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e IM |
5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> | |
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> |
cdd6c482 | 37 | #include <linux/perf_event.h> |
6fb2915d | 38 | #include <linux/ftrace_event.h> |
3c502e7a | 39 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 40 | #include <linux/mm_types.h> |
877c6856 | 41 | #include <linux/cgroup.h> |
0793a61d | 42 | |
76369139 FW |
43 | #include "internal.h" |
44 | ||
4e193bd4 TB |
45 | #include <asm/irq_regs.h> |
46 | ||
fe4b04fa | 47 | struct remote_function_call { |
e7e7ee2e IM |
48 | struct task_struct *p; |
49 | int (*func)(void *info); | |
50 | void *info; | |
51 | int ret; | |
fe4b04fa PZ |
52 | }; |
53 | ||
54 | static void remote_function(void *data) | |
55 | { | |
56 | struct remote_function_call *tfc = data; | |
57 | struct task_struct *p = tfc->p; | |
58 | ||
59 | if (p) { | |
60 | tfc->ret = -EAGAIN; | |
61 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
62 | return; | |
63 | } | |
64 | ||
65 | tfc->ret = tfc->func(tfc->info); | |
66 | } | |
67 | ||
68 | /** | |
69 | * task_function_call - call a function on the cpu on which a task runs | |
70 | * @p: the task to evaluate | |
71 | * @func: the function to be called | |
72 | * @info: the function call argument | |
73 | * | |
74 | * Calls the function @func when the task is currently running. This might | |
75 | * be on the current CPU, which just calls the function directly | |
76 | * | |
77 | * returns: @func return value, or | |
78 | * -ESRCH - when the process isn't running | |
79 | * -EAGAIN - when the process moved away | |
80 | */ | |
81 | static int | |
82 | task_function_call(struct task_struct *p, int (*func) (void *info), void *info) | |
83 | { | |
84 | struct remote_function_call data = { | |
e7e7ee2e IM |
85 | .p = p, |
86 | .func = func, | |
87 | .info = info, | |
88 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
89 | }; |
90 | ||
91 | if (task_curr(p)) | |
92 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
93 | ||
94 | return data.ret; | |
95 | } | |
96 | ||
97 | /** | |
98 | * cpu_function_call - call a function on the cpu | |
99 | * @func: the function to be called | |
100 | * @info: the function call argument | |
101 | * | |
102 | * Calls the function @func on the remote cpu. | |
103 | * | |
104 | * returns: @func return value or -ENXIO when the cpu is offline | |
105 | */ | |
106 | static int cpu_function_call(int cpu, int (*func) (void *info), void *info) | |
107 | { | |
108 | struct remote_function_call data = { | |
e7e7ee2e IM |
109 | .p = NULL, |
110 | .func = func, | |
111 | .info = info, | |
112 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
113 | }; |
114 | ||
115 | smp_call_function_single(cpu, remote_function, &data, 1); | |
116 | ||
117 | return data.ret; | |
118 | } | |
119 | ||
e5d1367f SE |
120 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
121 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
122 | PERF_FLAG_PID_CGROUP |\ |
123 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 124 | |
bce38cd5 SE |
125 | /* |
126 | * branch priv levels that need permission checks | |
127 | */ | |
128 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
129 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
130 | PERF_SAMPLE_BRANCH_HV) | |
131 | ||
0b3fcf17 SE |
132 | enum event_type_t { |
133 | EVENT_FLEXIBLE = 0x1, | |
134 | EVENT_PINNED = 0x2, | |
135 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
136 | }; | |
137 | ||
e5d1367f SE |
138 | /* |
139 | * perf_sched_events : >0 events exist | |
140 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
141 | */ | |
c5905afb | 142 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 143 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
d010b332 | 144 | static DEFINE_PER_CPU(atomic_t, perf_branch_stack_events); |
e5d1367f | 145 | |
cdd6c482 IM |
146 | static atomic_t nr_mmap_events __read_mostly; |
147 | static atomic_t nr_comm_events __read_mostly; | |
148 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 149 | static atomic_t nr_freq_events __read_mostly; |
9ee318a7 | 150 | |
108b02cf PZ |
151 | static LIST_HEAD(pmus); |
152 | static DEFINE_MUTEX(pmus_lock); | |
153 | static struct srcu_struct pmus_srcu; | |
154 | ||
0764771d | 155 | /* |
cdd6c482 | 156 | * perf event paranoia level: |
0fbdea19 IM |
157 | * -1 - not paranoid at all |
158 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 159 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 160 | * 2 - disallow kernel profiling for unpriv |
0764771d | 161 | */ |
cdd6c482 | 162 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 163 | |
20443384 FW |
164 | /* Minimum for 512 kiB + 1 user control page */ |
165 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
166 | |
167 | /* | |
cdd6c482 | 168 | * max perf event sample rate |
df58ab24 | 169 | */ |
14c63f17 DH |
170 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
171 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
172 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
173 | ||
174 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
175 | ||
176 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
177 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
178 | ||
d9494cb4 PZ |
179 | static int perf_sample_allowed_ns __read_mostly = |
180 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 DH |
181 | |
182 | void update_perf_cpu_limits(void) | |
183 | { | |
184 | u64 tmp = perf_sample_period_ns; | |
185 | ||
186 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 187 | do_div(tmp, 100); |
d9494cb4 | 188 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 189 | } |
163ec435 | 190 | |
9e630205 SE |
191 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
192 | ||
163ec435 PZ |
193 | int perf_proc_update_handler(struct ctl_table *table, int write, |
194 | void __user *buffer, size_t *lenp, | |
195 | loff_t *ppos) | |
196 | { | |
723478c8 | 197 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
198 | |
199 | if (ret || !write) | |
200 | return ret; | |
201 | ||
202 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
203 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
204 | update_perf_cpu_limits(); | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
210 | ||
211 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
212 | void __user *buffer, size_t *lenp, | |
213 | loff_t *ppos) | |
214 | { | |
215 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
216 | ||
217 | if (ret || !write) | |
218 | return ret; | |
219 | ||
220 | update_perf_cpu_limits(); | |
163ec435 PZ |
221 | |
222 | return 0; | |
223 | } | |
1ccd1549 | 224 | |
14c63f17 DH |
225 | /* |
226 | * perf samples are done in some very critical code paths (NMIs). | |
227 | * If they take too much CPU time, the system can lock up and not | |
228 | * get any real work done. This will drop the sample rate when | |
229 | * we detect that events are taking too long. | |
230 | */ | |
231 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 232 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 233 | |
6a02ad66 | 234 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 235 | { |
6a02ad66 | 236 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 237 | u64 avg_local_sample_len; |
e5302920 | 238 | u64 local_samples_len; |
6a02ad66 PZ |
239 | |
240 | local_samples_len = __get_cpu_var(running_sample_length); | |
241 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
242 | ||
243 | printk_ratelimited(KERN_WARNING | |
244 | "perf interrupt took too long (%lld > %lld), lowering " | |
245 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 246 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
247 | sysctl_perf_event_sample_rate); |
248 | } | |
249 | ||
250 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
251 | ||
252 | void perf_sample_event_took(u64 sample_len_ns) | |
253 | { | |
d9494cb4 | 254 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
255 | u64 avg_local_sample_len; |
256 | u64 local_samples_len; | |
14c63f17 | 257 | |
d9494cb4 | 258 | if (allowed_ns == 0) |
14c63f17 DH |
259 | return; |
260 | ||
261 | /* decay the counter by 1 average sample */ | |
262 | local_samples_len = __get_cpu_var(running_sample_length); | |
263 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; | |
264 | local_samples_len += sample_len_ns; | |
265 | __get_cpu_var(running_sample_length) = local_samples_len; | |
266 | ||
267 | /* | |
268 | * note: this will be biased artifically low until we have | |
269 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
270 | * from having to maintain a count. | |
271 | */ | |
272 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
273 | ||
d9494cb4 | 274 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
275 | return; |
276 | ||
277 | if (max_samples_per_tick <= 1) | |
278 | return; | |
279 | ||
280 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
281 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
282 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
283 | ||
14c63f17 | 284 | update_perf_cpu_limits(); |
6a02ad66 | 285 | |
cd578abb PZ |
286 | if (!irq_work_queue(&perf_duration_work)) { |
287 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
288 | "kernel.perf_event_max_sample_rate to %d\n", | |
289 | avg_local_sample_len, allowed_ns >> 1, | |
290 | sysctl_perf_event_sample_rate); | |
291 | } | |
14c63f17 DH |
292 | } |
293 | ||
cdd6c482 | 294 | static atomic64_t perf_event_id; |
a96bbc16 | 295 | |
0b3fcf17 SE |
296 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
297 | enum event_type_t event_type); | |
298 | ||
299 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
300 | enum event_type_t event_type, |
301 | struct task_struct *task); | |
302 | ||
303 | static void update_context_time(struct perf_event_context *ctx); | |
304 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 305 | |
cdd6c482 | 306 | void __weak perf_event_print_debug(void) { } |
0793a61d | 307 | |
84c79910 | 308 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 309 | { |
84c79910 | 310 | return "pmu"; |
0793a61d TG |
311 | } |
312 | ||
0b3fcf17 SE |
313 | static inline u64 perf_clock(void) |
314 | { | |
315 | return local_clock(); | |
316 | } | |
317 | ||
e5d1367f SE |
318 | static inline struct perf_cpu_context * |
319 | __get_cpu_context(struct perf_event_context *ctx) | |
320 | { | |
321 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
322 | } | |
323 | ||
facc4307 PZ |
324 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, |
325 | struct perf_event_context *ctx) | |
326 | { | |
327 | raw_spin_lock(&cpuctx->ctx.lock); | |
328 | if (ctx) | |
329 | raw_spin_lock(&ctx->lock); | |
330 | } | |
331 | ||
332 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
333 | struct perf_event_context *ctx) | |
334 | { | |
335 | if (ctx) | |
336 | raw_spin_unlock(&ctx->lock); | |
337 | raw_spin_unlock(&cpuctx->ctx.lock); | |
338 | } | |
339 | ||
e5d1367f SE |
340 | #ifdef CONFIG_CGROUP_PERF |
341 | ||
877c6856 LZ |
342 | /* |
343 | * perf_cgroup_info keeps track of time_enabled for a cgroup. | |
344 | * This is a per-cpu dynamically allocated data structure. | |
345 | */ | |
346 | struct perf_cgroup_info { | |
347 | u64 time; | |
348 | u64 timestamp; | |
349 | }; | |
350 | ||
351 | struct perf_cgroup { | |
352 | struct cgroup_subsys_state css; | |
86e213e1 | 353 | struct perf_cgroup_info __percpu *info; |
877c6856 LZ |
354 | }; |
355 | ||
3f7cce3c SE |
356 | /* |
357 | * Must ensure cgroup is pinned (css_get) before calling | |
358 | * this function. In other words, we cannot call this function | |
359 | * if there is no cgroup event for the current CPU context. | |
360 | */ | |
e5d1367f SE |
361 | static inline struct perf_cgroup * |
362 | perf_cgroup_from_task(struct task_struct *task) | |
363 | { | |
073219e9 | 364 | return container_of(task_css(task, perf_event_cgrp_id), |
8af01f56 | 365 | struct perf_cgroup, css); |
e5d1367f SE |
366 | } |
367 | ||
368 | static inline bool | |
369 | perf_cgroup_match(struct perf_event *event) | |
370 | { | |
371 | struct perf_event_context *ctx = event->ctx; | |
372 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
373 | ||
ef824fa1 TH |
374 | /* @event doesn't care about cgroup */ |
375 | if (!event->cgrp) | |
376 | return true; | |
377 | ||
378 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
379 | if (!cpuctx->cgrp) | |
380 | return false; | |
381 | ||
382 | /* | |
383 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
384 | * also enabled for all its descendant cgroups. If @cpuctx's | |
385 | * cgroup is a descendant of @event's (the test covers identity | |
386 | * case), it's a match. | |
387 | */ | |
388 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
389 | event->cgrp->css.cgroup); | |
e5d1367f SE |
390 | } |
391 | ||
e5d1367f SE |
392 | static inline void perf_put_cgroup(struct perf_event *event) |
393 | { | |
394 | css_put(&event->cgrp->css); | |
395 | } | |
396 | ||
397 | static inline void perf_detach_cgroup(struct perf_event *event) | |
398 | { | |
399 | perf_put_cgroup(event); | |
400 | event->cgrp = NULL; | |
401 | } | |
402 | ||
403 | static inline int is_cgroup_event(struct perf_event *event) | |
404 | { | |
405 | return event->cgrp != NULL; | |
406 | } | |
407 | ||
408 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
409 | { | |
410 | struct perf_cgroup_info *t; | |
411 | ||
412 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
413 | return t->time; | |
414 | } | |
415 | ||
416 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
417 | { | |
418 | struct perf_cgroup_info *info; | |
419 | u64 now; | |
420 | ||
421 | now = perf_clock(); | |
422 | ||
423 | info = this_cpu_ptr(cgrp->info); | |
424 | ||
425 | info->time += now - info->timestamp; | |
426 | info->timestamp = now; | |
427 | } | |
428 | ||
429 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
430 | { | |
431 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
432 | if (cgrp_out) | |
433 | __update_cgrp_time(cgrp_out); | |
434 | } | |
435 | ||
436 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
437 | { | |
3f7cce3c SE |
438 | struct perf_cgroup *cgrp; |
439 | ||
e5d1367f | 440 | /* |
3f7cce3c SE |
441 | * ensure we access cgroup data only when needed and |
442 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 443 | */ |
3f7cce3c | 444 | if (!is_cgroup_event(event)) |
e5d1367f SE |
445 | return; |
446 | ||
3f7cce3c SE |
447 | cgrp = perf_cgroup_from_task(current); |
448 | /* | |
449 | * Do not update time when cgroup is not active | |
450 | */ | |
451 | if (cgrp == event->cgrp) | |
452 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
453 | } |
454 | ||
455 | static inline void | |
3f7cce3c SE |
456 | perf_cgroup_set_timestamp(struct task_struct *task, |
457 | struct perf_event_context *ctx) | |
e5d1367f SE |
458 | { |
459 | struct perf_cgroup *cgrp; | |
460 | struct perf_cgroup_info *info; | |
461 | ||
3f7cce3c SE |
462 | /* |
463 | * ctx->lock held by caller | |
464 | * ensure we do not access cgroup data | |
465 | * unless we have the cgroup pinned (css_get) | |
466 | */ | |
467 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
468 | return; |
469 | ||
470 | cgrp = perf_cgroup_from_task(task); | |
471 | info = this_cpu_ptr(cgrp->info); | |
3f7cce3c | 472 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
473 | } |
474 | ||
475 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
476 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
477 | ||
478 | /* | |
479 | * reschedule events based on the cgroup constraint of task. | |
480 | * | |
481 | * mode SWOUT : schedule out everything | |
482 | * mode SWIN : schedule in based on cgroup for next | |
483 | */ | |
484 | void perf_cgroup_switch(struct task_struct *task, int mode) | |
485 | { | |
486 | struct perf_cpu_context *cpuctx; | |
487 | struct pmu *pmu; | |
488 | unsigned long flags; | |
489 | ||
490 | /* | |
491 | * disable interrupts to avoid geting nr_cgroup | |
492 | * changes via __perf_event_disable(). Also | |
493 | * avoids preemption. | |
494 | */ | |
495 | local_irq_save(flags); | |
496 | ||
497 | /* | |
498 | * we reschedule only in the presence of cgroup | |
499 | * constrained events. | |
500 | */ | |
501 | rcu_read_lock(); | |
502 | ||
503 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 504 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
505 | if (cpuctx->unique_pmu != pmu) |
506 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 507 | |
e5d1367f SE |
508 | /* |
509 | * perf_cgroup_events says at least one | |
510 | * context on this CPU has cgroup events. | |
511 | * | |
512 | * ctx->nr_cgroups reports the number of cgroup | |
513 | * events for a context. | |
514 | */ | |
515 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
516 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
517 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
518 | |
519 | if (mode & PERF_CGROUP_SWOUT) { | |
520 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
521 | /* | |
522 | * must not be done before ctxswout due | |
523 | * to event_filter_match() in event_sched_out() | |
524 | */ | |
525 | cpuctx->cgrp = NULL; | |
526 | } | |
527 | ||
528 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 529 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
530 | /* |
531 | * set cgrp before ctxsw in to allow | |
532 | * event_filter_match() to not have to pass | |
533 | * task around | |
e5d1367f SE |
534 | */ |
535 | cpuctx->cgrp = perf_cgroup_from_task(task); | |
536 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); | |
537 | } | |
facc4307 PZ |
538 | perf_pmu_enable(cpuctx->ctx.pmu); |
539 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 540 | } |
e5d1367f SE |
541 | } |
542 | ||
543 | rcu_read_unlock(); | |
544 | ||
545 | local_irq_restore(flags); | |
546 | } | |
547 | ||
a8d757ef SE |
548 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
549 | struct task_struct *next) | |
e5d1367f | 550 | { |
a8d757ef SE |
551 | struct perf_cgroup *cgrp1; |
552 | struct perf_cgroup *cgrp2 = NULL; | |
553 | ||
554 | /* | |
555 | * we come here when we know perf_cgroup_events > 0 | |
556 | */ | |
557 | cgrp1 = perf_cgroup_from_task(task); | |
558 | ||
559 | /* | |
560 | * next is NULL when called from perf_event_enable_on_exec() | |
561 | * that will systematically cause a cgroup_switch() | |
562 | */ | |
563 | if (next) | |
564 | cgrp2 = perf_cgroup_from_task(next); | |
565 | ||
566 | /* | |
567 | * only schedule out current cgroup events if we know | |
568 | * that we are switching to a different cgroup. Otherwise, | |
569 | * do no touch the cgroup events. | |
570 | */ | |
571 | if (cgrp1 != cgrp2) | |
572 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
e5d1367f SE |
573 | } |
574 | ||
a8d757ef SE |
575 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
576 | struct task_struct *task) | |
e5d1367f | 577 | { |
a8d757ef SE |
578 | struct perf_cgroup *cgrp1; |
579 | struct perf_cgroup *cgrp2 = NULL; | |
580 | ||
581 | /* | |
582 | * we come here when we know perf_cgroup_events > 0 | |
583 | */ | |
584 | cgrp1 = perf_cgroup_from_task(task); | |
585 | ||
586 | /* prev can never be NULL */ | |
587 | cgrp2 = perf_cgroup_from_task(prev); | |
588 | ||
589 | /* | |
590 | * only need to schedule in cgroup events if we are changing | |
591 | * cgroup during ctxsw. Cgroup events were not scheduled | |
592 | * out of ctxsw out if that was not the case. | |
593 | */ | |
594 | if (cgrp1 != cgrp2) | |
595 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
e5d1367f SE |
596 | } |
597 | ||
598 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
599 | struct perf_event_attr *attr, | |
600 | struct perf_event *group_leader) | |
601 | { | |
602 | struct perf_cgroup *cgrp; | |
603 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
604 | struct fd f = fdget(fd); |
605 | int ret = 0; | |
e5d1367f | 606 | |
2903ff01 | 607 | if (!f.file) |
e5d1367f SE |
608 | return -EBADF; |
609 | ||
5a17f543 | 610 | css = css_tryget_from_dir(f.file->f_dentry, &perf_event_cgrp_subsys); |
3db272c0 LZ |
611 | if (IS_ERR(css)) { |
612 | ret = PTR_ERR(css); | |
613 | goto out; | |
614 | } | |
e5d1367f SE |
615 | |
616 | cgrp = container_of(css, struct perf_cgroup, css); | |
617 | event->cgrp = cgrp; | |
618 | ||
619 | /* | |
620 | * all events in a group must monitor | |
621 | * the same cgroup because a task belongs | |
622 | * to only one perf cgroup at a time | |
623 | */ | |
624 | if (group_leader && group_leader->cgrp != cgrp) { | |
625 | perf_detach_cgroup(event); | |
626 | ret = -EINVAL; | |
e5d1367f | 627 | } |
3db272c0 | 628 | out: |
2903ff01 | 629 | fdput(f); |
e5d1367f SE |
630 | return ret; |
631 | } | |
632 | ||
633 | static inline void | |
634 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
635 | { | |
636 | struct perf_cgroup_info *t; | |
637 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
638 | event->shadow_ctx_time = now - t->timestamp; | |
639 | } | |
640 | ||
641 | static inline void | |
642 | perf_cgroup_defer_enabled(struct perf_event *event) | |
643 | { | |
644 | /* | |
645 | * when the current task's perf cgroup does not match | |
646 | * the event's, we need to remember to call the | |
647 | * perf_mark_enable() function the first time a task with | |
648 | * a matching perf cgroup is scheduled in. | |
649 | */ | |
650 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
651 | event->cgrp_defer_enabled = 1; | |
652 | } | |
653 | ||
654 | static inline void | |
655 | perf_cgroup_mark_enabled(struct perf_event *event, | |
656 | struct perf_event_context *ctx) | |
657 | { | |
658 | struct perf_event *sub; | |
659 | u64 tstamp = perf_event_time(event); | |
660 | ||
661 | if (!event->cgrp_defer_enabled) | |
662 | return; | |
663 | ||
664 | event->cgrp_defer_enabled = 0; | |
665 | ||
666 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
667 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
668 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
669 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
670 | sub->cgrp_defer_enabled = 0; | |
671 | } | |
672 | } | |
673 | } | |
674 | #else /* !CONFIG_CGROUP_PERF */ | |
675 | ||
676 | static inline bool | |
677 | perf_cgroup_match(struct perf_event *event) | |
678 | { | |
679 | return true; | |
680 | } | |
681 | ||
682 | static inline void perf_detach_cgroup(struct perf_event *event) | |
683 | {} | |
684 | ||
685 | static inline int is_cgroup_event(struct perf_event *event) | |
686 | { | |
687 | return 0; | |
688 | } | |
689 | ||
690 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
691 | { | |
692 | return 0; | |
693 | } | |
694 | ||
695 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
696 | { | |
697 | } | |
698 | ||
699 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
700 | { | |
701 | } | |
702 | ||
a8d757ef SE |
703 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
704 | struct task_struct *next) | |
e5d1367f SE |
705 | { |
706 | } | |
707 | ||
a8d757ef SE |
708 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
709 | struct task_struct *task) | |
e5d1367f SE |
710 | { |
711 | } | |
712 | ||
713 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
714 | struct perf_event_attr *attr, | |
715 | struct perf_event *group_leader) | |
716 | { | |
717 | return -EINVAL; | |
718 | } | |
719 | ||
720 | static inline void | |
3f7cce3c SE |
721 | perf_cgroup_set_timestamp(struct task_struct *task, |
722 | struct perf_event_context *ctx) | |
e5d1367f SE |
723 | { |
724 | } | |
725 | ||
726 | void | |
727 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
728 | { | |
729 | } | |
730 | ||
731 | static inline void | |
732 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
733 | { | |
734 | } | |
735 | ||
736 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
737 | { | |
738 | return 0; | |
739 | } | |
740 | ||
741 | static inline void | |
742 | perf_cgroup_defer_enabled(struct perf_event *event) | |
743 | { | |
744 | } | |
745 | ||
746 | static inline void | |
747 | perf_cgroup_mark_enabled(struct perf_event *event, | |
748 | struct perf_event_context *ctx) | |
749 | { | |
750 | } | |
751 | #endif | |
752 | ||
9e630205 SE |
753 | /* |
754 | * set default to be dependent on timer tick just | |
755 | * like original code | |
756 | */ | |
757 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
758 | /* | |
759 | * function must be called with interrupts disbled | |
760 | */ | |
761 | static enum hrtimer_restart perf_cpu_hrtimer_handler(struct hrtimer *hr) | |
762 | { | |
763 | struct perf_cpu_context *cpuctx; | |
764 | enum hrtimer_restart ret = HRTIMER_NORESTART; | |
765 | int rotations = 0; | |
766 | ||
767 | WARN_ON(!irqs_disabled()); | |
768 | ||
769 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
770 | ||
771 | rotations = perf_rotate_context(cpuctx); | |
772 | ||
773 | /* | |
774 | * arm timer if needed | |
775 | */ | |
776 | if (rotations) { | |
777 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); | |
778 | ret = HRTIMER_RESTART; | |
779 | } | |
780 | ||
781 | return ret; | |
782 | } | |
783 | ||
784 | /* CPU is going down */ | |
785 | void perf_cpu_hrtimer_cancel(int cpu) | |
786 | { | |
787 | struct perf_cpu_context *cpuctx; | |
788 | struct pmu *pmu; | |
789 | unsigned long flags; | |
790 | ||
791 | if (WARN_ON(cpu != smp_processor_id())) | |
792 | return; | |
793 | ||
794 | local_irq_save(flags); | |
795 | ||
796 | rcu_read_lock(); | |
797 | ||
798 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
799 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
800 | ||
801 | if (pmu->task_ctx_nr == perf_sw_context) | |
802 | continue; | |
803 | ||
804 | hrtimer_cancel(&cpuctx->hrtimer); | |
805 | } | |
806 | ||
807 | rcu_read_unlock(); | |
808 | ||
809 | local_irq_restore(flags); | |
810 | } | |
811 | ||
812 | static void __perf_cpu_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) | |
813 | { | |
814 | struct hrtimer *hr = &cpuctx->hrtimer; | |
815 | struct pmu *pmu = cpuctx->ctx.pmu; | |
62b85639 | 816 | int timer; |
9e630205 SE |
817 | |
818 | /* no multiplexing needed for SW PMU */ | |
819 | if (pmu->task_ctx_nr == perf_sw_context) | |
820 | return; | |
821 | ||
62b85639 SE |
822 | /* |
823 | * check default is sane, if not set then force to | |
824 | * default interval (1/tick) | |
825 | */ | |
826 | timer = pmu->hrtimer_interval_ms; | |
827 | if (timer < 1) | |
828 | timer = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
829 | ||
830 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
9e630205 SE |
831 | |
832 | hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED); | |
833 | hr->function = perf_cpu_hrtimer_handler; | |
834 | } | |
835 | ||
836 | static void perf_cpu_hrtimer_restart(struct perf_cpu_context *cpuctx) | |
837 | { | |
838 | struct hrtimer *hr = &cpuctx->hrtimer; | |
839 | struct pmu *pmu = cpuctx->ctx.pmu; | |
840 | ||
841 | /* not for SW PMU */ | |
842 | if (pmu->task_ctx_nr == perf_sw_context) | |
843 | return; | |
844 | ||
845 | if (hrtimer_active(hr)) | |
846 | return; | |
847 | ||
848 | if (!hrtimer_callback_running(hr)) | |
849 | __hrtimer_start_range_ns(hr, cpuctx->hrtimer_interval, | |
850 | 0, HRTIMER_MODE_REL_PINNED, 0); | |
851 | } | |
852 | ||
33696fc0 | 853 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 854 | { |
33696fc0 PZ |
855 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
856 | if (!(*count)++) | |
857 | pmu->pmu_disable(pmu); | |
9e35ad38 | 858 | } |
9e35ad38 | 859 | |
33696fc0 | 860 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 861 | { |
33696fc0 PZ |
862 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
863 | if (!--(*count)) | |
864 | pmu->pmu_enable(pmu); | |
9e35ad38 | 865 | } |
9e35ad38 | 866 | |
e9d2b064 PZ |
867 | static DEFINE_PER_CPU(struct list_head, rotation_list); |
868 | ||
869 | /* | |
870 | * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized | |
871 | * because they're strictly cpu affine and rotate_start is called with IRQs | |
872 | * disabled, while rotate_context is called from IRQ context. | |
873 | */ | |
108b02cf | 874 | static void perf_pmu_rotate_start(struct pmu *pmu) |
9e35ad38 | 875 | { |
108b02cf | 876 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
e9d2b064 | 877 | struct list_head *head = &__get_cpu_var(rotation_list); |
b5ab4cd5 | 878 | |
e9d2b064 | 879 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 880 | |
d84153d6 | 881 | if (list_empty(&cpuctx->rotation_list)) |
e9d2b064 | 882 | list_add(&cpuctx->rotation_list, head); |
9e35ad38 | 883 | } |
9e35ad38 | 884 | |
cdd6c482 | 885 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 886 | { |
e5289d4a | 887 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
888 | } |
889 | ||
cdd6c482 | 890 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 891 | { |
564c2b21 PM |
892 | if (atomic_dec_and_test(&ctx->refcount)) { |
893 | if (ctx->parent_ctx) | |
894 | put_ctx(ctx->parent_ctx); | |
c93f7669 PM |
895 | if (ctx->task) |
896 | put_task_struct(ctx->task); | |
cb796ff3 | 897 | kfree_rcu(ctx, rcu_head); |
564c2b21 | 898 | } |
a63eaf34 PM |
899 | } |
900 | ||
cdd6c482 | 901 | static void unclone_ctx(struct perf_event_context *ctx) |
71a851b4 PZ |
902 | { |
903 | if (ctx->parent_ctx) { | |
904 | put_ctx(ctx->parent_ctx); | |
905 | ctx->parent_ctx = NULL; | |
906 | } | |
5a3126d4 | 907 | ctx->generation++; |
71a851b4 PZ |
908 | } |
909 | ||
6844c09d ACM |
910 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
911 | { | |
912 | /* | |
913 | * only top level events have the pid namespace they were created in | |
914 | */ | |
915 | if (event->parent) | |
916 | event = event->parent; | |
917 | ||
918 | return task_tgid_nr_ns(p, event->ns); | |
919 | } | |
920 | ||
921 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
922 | { | |
923 | /* | |
924 | * only top level events have the pid namespace they were created in | |
925 | */ | |
926 | if (event->parent) | |
927 | event = event->parent; | |
928 | ||
929 | return task_pid_nr_ns(p, event->ns); | |
930 | } | |
931 | ||
7f453c24 | 932 | /* |
cdd6c482 | 933 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
934 | * to userspace. |
935 | */ | |
cdd6c482 | 936 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 937 | { |
cdd6c482 | 938 | u64 id = event->id; |
7f453c24 | 939 | |
cdd6c482 IM |
940 | if (event->parent) |
941 | id = event->parent->id; | |
7f453c24 PZ |
942 | |
943 | return id; | |
944 | } | |
945 | ||
25346b93 | 946 | /* |
cdd6c482 | 947 | * Get the perf_event_context for a task and lock it. |
25346b93 PM |
948 | * This has to cope with with the fact that until it is locked, |
949 | * the context could get moved to another task. | |
950 | */ | |
cdd6c482 | 951 | static struct perf_event_context * |
8dc85d54 | 952 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 953 | { |
cdd6c482 | 954 | struct perf_event_context *ctx; |
25346b93 | 955 | |
9ed6060d | 956 | retry: |
058ebd0e PZ |
957 | /* |
958 | * One of the few rules of preemptible RCU is that one cannot do | |
959 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
960 | * part of the read side critical section was preemptible -- see | |
961 | * rcu_read_unlock_special(). | |
962 | * | |
963 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
964 | * side critical section is non-preemptible. | |
965 | */ | |
966 | preempt_disable(); | |
967 | rcu_read_lock(); | |
8dc85d54 | 968 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
969 | if (ctx) { |
970 | /* | |
971 | * If this context is a clone of another, it might | |
972 | * get swapped for another underneath us by | |
cdd6c482 | 973 | * perf_event_task_sched_out, though the |
25346b93 PM |
974 | * rcu_read_lock() protects us from any context |
975 | * getting freed. Lock the context and check if it | |
976 | * got swapped before we could get the lock, and retry | |
977 | * if so. If we locked the right context, then it | |
978 | * can't get swapped on us any more. | |
979 | */ | |
e625cce1 | 980 | raw_spin_lock_irqsave(&ctx->lock, *flags); |
8dc85d54 | 981 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
e625cce1 | 982 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); |
058ebd0e PZ |
983 | rcu_read_unlock(); |
984 | preempt_enable(); | |
25346b93 PM |
985 | goto retry; |
986 | } | |
b49a9e7e PZ |
987 | |
988 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
e625cce1 | 989 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); |
b49a9e7e PZ |
990 | ctx = NULL; |
991 | } | |
25346b93 PM |
992 | } |
993 | rcu_read_unlock(); | |
058ebd0e | 994 | preempt_enable(); |
25346b93 PM |
995 | return ctx; |
996 | } | |
997 | ||
998 | /* | |
999 | * Get the context for a task and increment its pin_count so it | |
1000 | * can't get swapped to another task. This also increments its | |
1001 | * reference count so that the context can't get freed. | |
1002 | */ | |
8dc85d54 PZ |
1003 | static struct perf_event_context * |
1004 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1005 | { |
cdd6c482 | 1006 | struct perf_event_context *ctx; |
25346b93 PM |
1007 | unsigned long flags; |
1008 | ||
8dc85d54 | 1009 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1010 | if (ctx) { |
1011 | ++ctx->pin_count; | |
e625cce1 | 1012 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1013 | } |
1014 | return ctx; | |
1015 | } | |
1016 | ||
cdd6c482 | 1017 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1018 | { |
1019 | unsigned long flags; | |
1020 | ||
e625cce1 | 1021 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1022 | --ctx->pin_count; |
e625cce1 | 1023 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1024 | } |
1025 | ||
f67218c3 PZ |
1026 | /* |
1027 | * Update the record of the current time in a context. | |
1028 | */ | |
1029 | static void update_context_time(struct perf_event_context *ctx) | |
1030 | { | |
1031 | u64 now = perf_clock(); | |
1032 | ||
1033 | ctx->time += now - ctx->timestamp; | |
1034 | ctx->timestamp = now; | |
1035 | } | |
1036 | ||
4158755d SE |
1037 | static u64 perf_event_time(struct perf_event *event) |
1038 | { | |
1039 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1040 | |
1041 | if (is_cgroup_event(event)) | |
1042 | return perf_cgroup_event_time(event); | |
1043 | ||
4158755d SE |
1044 | return ctx ? ctx->time : 0; |
1045 | } | |
1046 | ||
f67218c3 PZ |
1047 | /* |
1048 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1049 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1050 | */ |
1051 | static void update_event_times(struct perf_event *event) | |
1052 | { | |
1053 | struct perf_event_context *ctx = event->ctx; | |
1054 | u64 run_end; | |
1055 | ||
1056 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1057 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1058 | return; | |
e5d1367f SE |
1059 | /* |
1060 | * in cgroup mode, time_enabled represents | |
1061 | * the time the event was enabled AND active | |
1062 | * tasks were in the monitored cgroup. This is | |
1063 | * independent of the activity of the context as | |
1064 | * there may be a mix of cgroup and non-cgroup events. | |
1065 | * | |
1066 | * That is why we treat cgroup events differently | |
1067 | * here. | |
1068 | */ | |
1069 | if (is_cgroup_event(event)) | |
46cd6a7f | 1070 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1071 | else if (ctx->is_active) |
1072 | run_end = ctx->time; | |
acd1d7c1 PZ |
1073 | else |
1074 | run_end = event->tstamp_stopped; | |
1075 | ||
1076 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1077 | |
1078 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1079 | run_end = event->tstamp_stopped; | |
1080 | else | |
4158755d | 1081 | run_end = perf_event_time(event); |
f67218c3 PZ |
1082 | |
1083 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1084 | |
f67218c3 PZ |
1085 | } |
1086 | ||
96c21a46 PZ |
1087 | /* |
1088 | * Update total_time_enabled and total_time_running for all events in a group. | |
1089 | */ | |
1090 | static void update_group_times(struct perf_event *leader) | |
1091 | { | |
1092 | struct perf_event *event; | |
1093 | ||
1094 | update_event_times(leader); | |
1095 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1096 | update_event_times(event); | |
1097 | } | |
1098 | ||
889ff015 FW |
1099 | static struct list_head * |
1100 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1101 | { | |
1102 | if (event->attr.pinned) | |
1103 | return &ctx->pinned_groups; | |
1104 | else | |
1105 | return &ctx->flexible_groups; | |
1106 | } | |
1107 | ||
fccc714b | 1108 | /* |
cdd6c482 | 1109 | * Add a event from the lists for its context. |
fccc714b PZ |
1110 | * Must be called with ctx->mutex and ctx->lock held. |
1111 | */ | |
04289bb9 | 1112 | static void |
cdd6c482 | 1113 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1114 | { |
8a49542c PZ |
1115 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1116 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1117 | |
1118 | /* | |
8a49542c PZ |
1119 | * If we're a stand alone event or group leader, we go to the context |
1120 | * list, group events are kept attached to the group so that | |
1121 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1122 | */ |
8a49542c | 1123 | if (event->group_leader == event) { |
889ff015 FW |
1124 | struct list_head *list; |
1125 | ||
d6f962b5 FW |
1126 | if (is_software_event(event)) |
1127 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1128 | ||
889ff015 FW |
1129 | list = ctx_group_list(event, ctx); |
1130 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1131 | } |
592903cd | 1132 | |
08309379 | 1133 | if (is_cgroup_event(event)) |
e5d1367f | 1134 | ctx->nr_cgroups++; |
e5d1367f | 1135 | |
d010b332 SE |
1136 | if (has_branch_stack(event)) |
1137 | ctx->nr_branch_stack++; | |
1138 | ||
cdd6c482 | 1139 | list_add_rcu(&event->event_entry, &ctx->event_list); |
b5ab4cd5 | 1140 | if (!ctx->nr_events) |
108b02cf | 1141 | perf_pmu_rotate_start(ctx->pmu); |
cdd6c482 IM |
1142 | ctx->nr_events++; |
1143 | if (event->attr.inherit_stat) | |
bfbd3381 | 1144 | ctx->nr_stat++; |
5a3126d4 PZ |
1145 | |
1146 | ctx->generation++; | |
04289bb9 IM |
1147 | } |
1148 | ||
0231bb53 JO |
1149 | /* |
1150 | * Initialize event state based on the perf_event_attr::disabled. | |
1151 | */ | |
1152 | static inline void perf_event__state_init(struct perf_event *event) | |
1153 | { | |
1154 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1155 | PERF_EVENT_STATE_INACTIVE; | |
1156 | } | |
1157 | ||
c320c7b7 ACM |
1158 | /* |
1159 | * Called at perf_event creation and when events are attached/detached from a | |
1160 | * group. | |
1161 | */ | |
1162 | static void perf_event__read_size(struct perf_event *event) | |
1163 | { | |
1164 | int entry = sizeof(u64); /* value */ | |
1165 | int size = 0; | |
1166 | int nr = 1; | |
1167 | ||
1168 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1169 | size += sizeof(u64); | |
1170 | ||
1171 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1172 | size += sizeof(u64); | |
1173 | ||
1174 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1175 | entry += sizeof(u64); | |
1176 | ||
1177 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
1178 | nr += event->group_leader->nr_siblings; | |
1179 | size += sizeof(u64); | |
1180 | } | |
1181 | ||
1182 | size += entry * nr; | |
1183 | event->read_size = size; | |
1184 | } | |
1185 | ||
1186 | static void perf_event__header_size(struct perf_event *event) | |
1187 | { | |
1188 | struct perf_sample_data *data; | |
1189 | u64 sample_type = event->attr.sample_type; | |
1190 | u16 size = 0; | |
1191 | ||
1192 | perf_event__read_size(event); | |
1193 | ||
1194 | if (sample_type & PERF_SAMPLE_IP) | |
1195 | size += sizeof(data->ip); | |
1196 | ||
6844c09d ACM |
1197 | if (sample_type & PERF_SAMPLE_ADDR) |
1198 | size += sizeof(data->addr); | |
1199 | ||
1200 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1201 | size += sizeof(data->period); | |
1202 | ||
c3feedf2 AK |
1203 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1204 | size += sizeof(data->weight); | |
1205 | ||
6844c09d ACM |
1206 | if (sample_type & PERF_SAMPLE_READ) |
1207 | size += event->read_size; | |
1208 | ||
d6be9ad6 SE |
1209 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1210 | size += sizeof(data->data_src.val); | |
1211 | ||
fdfbbd07 AK |
1212 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1213 | size += sizeof(data->txn); | |
1214 | ||
6844c09d ACM |
1215 | event->header_size = size; |
1216 | } | |
1217 | ||
1218 | static void perf_event__id_header_size(struct perf_event *event) | |
1219 | { | |
1220 | struct perf_sample_data *data; | |
1221 | u64 sample_type = event->attr.sample_type; | |
1222 | u16 size = 0; | |
1223 | ||
c320c7b7 ACM |
1224 | if (sample_type & PERF_SAMPLE_TID) |
1225 | size += sizeof(data->tid_entry); | |
1226 | ||
1227 | if (sample_type & PERF_SAMPLE_TIME) | |
1228 | size += sizeof(data->time); | |
1229 | ||
ff3d527c AH |
1230 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1231 | size += sizeof(data->id); | |
1232 | ||
c320c7b7 ACM |
1233 | if (sample_type & PERF_SAMPLE_ID) |
1234 | size += sizeof(data->id); | |
1235 | ||
1236 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1237 | size += sizeof(data->stream_id); | |
1238 | ||
1239 | if (sample_type & PERF_SAMPLE_CPU) | |
1240 | size += sizeof(data->cpu_entry); | |
1241 | ||
6844c09d | 1242 | event->id_header_size = size; |
c320c7b7 ACM |
1243 | } |
1244 | ||
8a49542c PZ |
1245 | static void perf_group_attach(struct perf_event *event) |
1246 | { | |
c320c7b7 | 1247 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1248 | |
74c3337c PZ |
1249 | /* |
1250 | * We can have double attach due to group movement in perf_event_open. | |
1251 | */ | |
1252 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1253 | return; | |
1254 | ||
8a49542c PZ |
1255 | event->attach_state |= PERF_ATTACH_GROUP; |
1256 | ||
1257 | if (group_leader == event) | |
1258 | return; | |
1259 | ||
1260 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && | |
1261 | !is_software_event(event)) | |
1262 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1263 | ||
1264 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1265 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1266 | |
1267 | perf_event__header_size(group_leader); | |
1268 | ||
1269 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1270 | perf_event__header_size(pos); | |
8a49542c PZ |
1271 | } |
1272 | ||
a63eaf34 | 1273 | /* |
cdd6c482 | 1274 | * Remove a event from the lists for its context. |
fccc714b | 1275 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1276 | */ |
04289bb9 | 1277 | static void |
cdd6c482 | 1278 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1279 | { |
68cacd29 | 1280 | struct perf_cpu_context *cpuctx; |
8a49542c PZ |
1281 | /* |
1282 | * We can have double detach due to exit/hot-unplug + close. | |
1283 | */ | |
1284 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1285 | return; |
8a49542c PZ |
1286 | |
1287 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1288 | ||
68cacd29 | 1289 | if (is_cgroup_event(event)) { |
e5d1367f | 1290 | ctx->nr_cgroups--; |
68cacd29 SE |
1291 | cpuctx = __get_cpu_context(ctx); |
1292 | /* | |
1293 | * if there are no more cgroup events | |
1294 | * then cler cgrp to avoid stale pointer | |
1295 | * in update_cgrp_time_from_cpuctx() | |
1296 | */ | |
1297 | if (!ctx->nr_cgroups) | |
1298 | cpuctx->cgrp = NULL; | |
1299 | } | |
e5d1367f | 1300 | |
d010b332 SE |
1301 | if (has_branch_stack(event)) |
1302 | ctx->nr_branch_stack--; | |
1303 | ||
cdd6c482 IM |
1304 | ctx->nr_events--; |
1305 | if (event->attr.inherit_stat) | |
bfbd3381 | 1306 | ctx->nr_stat--; |
8bc20959 | 1307 | |
cdd6c482 | 1308 | list_del_rcu(&event->event_entry); |
04289bb9 | 1309 | |
8a49542c PZ |
1310 | if (event->group_leader == event) |
1311 | list_del_init(&event->group_entry); | |
5c148194 | 1312 | |
96c21a46 | 1313 | update_group_times(event); |
b2e74a26 SE |
1314 | |
1315 | /* | |
1316 | * If event was in error state, then keep it | |
1317 | * that way, otherwise bogus counts will be | |
1318 | * returned on read(). The only way to get out | |
1319 | * of error state is by explicit re-enabling | |
1320 | * of the event | |
1321 | */ | |
1322 | if (event->state > PERF_EVENT_STATE_OFF) | |
1323 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1324 | |
1325 | ctx->generation++; | |
050735b0 PZ |
1326 | } |
1327 | ||
8a49542c | 1328 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1329 | { |
1330 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1331 | struct list_head *list = NULL; |
1332 | ||
1333 | /* | |
1334 | * We can have double detach due to exit/hot-unplug + close. | |
1335 | */ | |
1336 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1337 | return; | |
1338 | ||
1339 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1340 | ||
1341 | /* | |
1342 | * If this is a sibling, remove it from its group. | |
1343 | */ | |
1344 | if (event->group_leader != event) { | |
1345 | list_del_init(&event->group_entry); | |
1346 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1347 | goto out; |
8a49542c PZ |
1348 | } |
1349 | ||
1350 | if (!list_empty(&event->group_entry)) | |
1351 | list = &event->group_entry; | |
2e2af50b | 1352 | |
04289bb9 | 1353 | /* |
cdd6c482 IM |
1354 | * If this was a group event with sibling events then |
1355 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1356 | * to whatever list we are on. |
04289bb9 | 1357 | */ |
cdd6c482 | 1358 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1359 | if (list) |
1360 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1361 | sibling->group_leader = sibling; |
d6f962b5 FW |
1362 | |
1363 | /* Inherit group flags from the previous leader */ | |
1364 | sibling->group_flags = event->group_flags; | |
04289bb9 | 1365 | } |
c320c7b7 ACM |
1366 | |
1367 | out: | |
1368 | perf_event__header_size(event->group_leader); | |
1369 | ||
1370 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1371 | perf_event__header_size(tmp); | |
04289bb9 IM |
1372 | } |
1373 | ||
fa66f07a SE |
1374 | static inline int |
1375 | event_filter_match(struct perf_event *event) | |
1376 | { | |
e5d1367f SE |
1377 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
1378 | && perf_cgroup_match(event); | |
fa66f07a SE |
1379 | } |
1380 | ||
9ffcfa6f SE |
1381 | static void |
1382 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1383 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1384 | struct perf_event_context *ctx) |
3b6f9e5c | 1385 | { |
4158755d | 1386 | u64 tstamp = perf_event_time(event); |
fa66f07a SE |
1387 | u64 delta; |
1388 | /* | |
1389 | * An event which could not be activated because of | |
1390 | * filter mismatch still needs to have its timings | |
1391 | * maintained, otherwise bogus information is return | |
1392 | * via read() for time_enabled, time_running: | |
1393 | */ | |
1394 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1395 | && !event_filter_match(event)) { | |
e5d1367f | 1396 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1397 | event->tstamp_running += delta; |
4158755d | 1398 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1399 | } |
1400 | ||
cdd6c482 | 1401 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1402 | return; |
3b6f9e5c | 1403 | |
44377277 AS |
1404 | perf_pmu_disable(event->pmu); |
1405 | ||
cdd6c482 IM |
1406 | event->state = PERF_EVENT_STATE_INACTIVE; |
1407 | if (event->pending_disable) { | |
1408 | event->pending_disable = 0; | |
1409 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1410 | } |
4158755d | 1411 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1412 | event->pmu->del(event, 0); |
cdd6c482 | 1413 | event->oncpu = -1; |
3b6f9e5c | 1414 | |
cdd6c482 | 1415 | if (!is_software_event(event)) |
3b6f9e5c PM |
1416 | cpuctx->active_oncpu--; |
1417 | ctx->nr_active--; | |
0f5a2601 PZ |
1418 | if (event->attr.freq && event->attr.sample_freq) |
1419 | ctx->nr_freq--; | |
cdd6c482 | 1420 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1421 | cpuctx->exclusive = 0; |
44377277 AS |
1422 | |
1423 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1424 | } |
1425 | ||
d859e29f | 1426 | static void |
cdd6c482 | 1427 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1428 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1429 | struct perf_event_context *ctx) |
d859e29f | 1430 | { |
cdd6c482 | 1431 | struct perf_event *event; |
fa66f07a | 1432 | int state = group_event->state; |
d859e29f | 1433 | |
cdd6c482 | 1434 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1435 | |
1436 | /* | |
1437 | * Schedule out siblings (if any): | |
1438 | */ | |
cdd6c482 IM |
1439 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1440 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1441 | |
fa66f07a | 1442 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1443 | cpuctx->exclusive = 0; |
1444 | } | |
1445 | ||
46ce0fe9 PZ |
1446 | struct remove_event { |
1447 | struct perf_event *event; | |
1448 | bool detach_group; | |
1449 | }; | |
1450 | ||
0793a61d | 1451 | /* |
cdd6c482 | 1452 | * Cross CPU call to remove a performance event |
0793a61d | 1453 | * |
cdd6c482 | 1454 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1455 | * remove it from the context list. |
1456 | */ | |
fe4b04fa | 1457 | static int __perf_remove_from_context(void *info) |
0793a61d | 1458 | { |
46ce0fe9 PZ |
1459 | struct remove_event *re = info; |
1460 | struct perf_event *event = re->event; | |
cdd6c482 | 1461 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1462 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
0793a61d | 1463 | |
e625cce1 | 1464 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 1465 | event_sched_out(event, cpuctx, ctx); |
46ce0fe9 PZ |
1466 | if (re->detach_group) |
1467 | perf_group_detach(event); | |
cdd6c482 | 1468 | list_del_event(event, ctx); |
64ce3126 PZ |
1469 | if (!ctx->nr_events && cpuctx->task_ctx == ctx) { |
1470 | ctx->is_active = 0; | |
1471 | cpuctx->task_ctx = NULL; | |
1472 | } | |
e625cce1 | 1473 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1474 | |
1475 | return 0; | |
0793a61d TG |
1476 | } |
1477 | ||
1478 | ||
1479 | /* | |
cdd6c482 | 1480 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1481 | * |
cdd6c482 | 1482 | * CPU events are removed with a smp call. For task events we only |
0793a61d | 1483 | * call when the task is on a CPU. |
c93f7669 | 1484 | * |
cdd6c482 IM |
1485 | * If event->ctx is a cloned context, callers must make sure that |
1486 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1487 | * remains valid. This is OK when called from perf_release since |
1488 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1489 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1490 | * context has been detached from its task. |
0793a61d | 1491 | */ |
46ce0fe9 | 1492 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1493 | { |
cdd6c482 | 1494 | struct perf_event_context *ctx = event->ctx; |
0793a61d | 1495 | struct task_struct *task = ctx->task; |
46ce0fe9 PZ |
1496 | struct remove_event re = { |
1497 | .event = event, | |
1498 | .detach_group = detach_group, | |
1499 | }; | |
0793a61d | 1500 | |
fe4b04fa PZ |
1501 | lockdep_assert_held(&ctx->mutex); |
1502 | ||
0793a61d TG |
1503 | if (!task) { |
1504 | /* | |
cdd6c482 | 1505 | * Per cpu events are removed via an smp call and |
af901ca1 | 1506 | * the removal is always successful. |
0793a61d | 1507 | */ |
46ce0fe9 | 1508 | cpu_function_call(event->cpu, __perf_remove_from_context, &re); |
0793a61d TG |
1509 | return; |
1510 | } | |
1511 | ||
1512 | retry: | |
46ce0fe9 | 1513 | if (!task_function_call(task, __perf_remove_from_context, &re)) |
fe4b04fa | 1514 | return; |
0793a61d | 1515 | |
e625cce1 | 1516 | raw_spin_lock_irq(&ctx->lock); |
0793a61d | 1517 | /* |
fe4b04fa PZ |
1518 | * If we failed to find a running task, but find the context active now |
1519 | * that we've acquired the ctx->lock, retry. | |
0793a61d | 1520 | */ |
fe4b04fa | 1521 | if (ctx->is_active) { |
e625cce1 | 1522 | raw_spin_unlock_irq(&ctx->lock); |
0793a61d TG |
1523 | goto retry; |
1524 | } | |
1525 | ||
1526 | /* | |
fe4b04fa PZ |
1527 | * Since the task isn't running, its safe to remove the event, us |
1528 | * holding the ctx->lock ensures the task won't get scheduled in. | |
0793a61d | 1529 | */ |
46ce0fe9 PZ |
1530 | if (detach_group) |
1531 | perf_group_detach(event); | |
fe4b04fa | 1532 | list_del_event(event, ctx); |
e625cce1 | 1533 | raw_spin_unlock_irq(&ctx->lock); |
0793a61d TG |
1534 | } |
1535 | ||
d859e29f | 1536 | /* |
cdd6c482 | 1537 | * Cross CPU call to disable a performance event |
d859e29f | 1538 | */ |
500ad2d8 | 1539 | int __perf_event_disable(void *info) |
d859e29f | 1540 | { |
cdd6c482 | 1541 | struct perf_event *event = info; |
cdd6c482 | 1542 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1543 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f PM |
1544 | |
1545 | /* | |
cdd6c482 IM |
1546 | * If this is a per-task event, need to check whether this |
1547 | * event's task is the current task on this cpu. | |
fe4b04fa PZ |
1548 | * |
1549 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1550 | * flipping contexts around. | |
d859e29f | 1551 | */ |
665c2142 | 1552 | if (ctx->task && cpuctx->task_ctx != ctx) |
fe4b04fa | 1553 | return -EINVAL; |
d859e29f | 1554 | |
e625cce1 | 1555 | raw_spin_lock(&ctx->lock); |
d859e29f PM |
1556 | |
1557 | /* | |
cdd6c482 | 1558 | * If the event is on, turn it off. |
d859e29f PM |
1559 | * If it is in error state, leave it in error state. |
1560 | */ | |
cdd6c482 | 1561 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
4af4998b | 1562 | update_context_time(ctx); |
e5d1367f | 1563 | update_cgrp_time_from_event(event); |
cdd6c482 IM |
1564 | update_group_times(event); |
1565 | if (event == event->group_leader) | |
1566 | group_sched_out(event, cpuctx, ctx); | |
d859e29f | 1567 | else |
cdd6c482 IM |
1568 | event_sched_out(event, cpuctx, ctx); |
1569 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f PM |
1570 | } |
1571 | ||
e625cce1 | 1572 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1573 | |
1574 | return 0; | |
d859e29f PM |
1575 | } |
1576 | ||
1577 | /* | |
cdd6c482 | 1578 | * Disable a event. |
c93f7669 | 1579 | * |
cdd6c482 IM |
1580 | * If event->ctx is a cloned context, callers must make sure that |
1581 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1582 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1583 | * perf_event_for_each_child or perf_event_for_each because they |
1584 | * hold the top-level event's child_mutex, so any descendant that | |
1585 | * goes to exit will block in sync_child_event. | |
1586 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1587 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1588 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1589 | */ |
44234adc | 1590 | void perf_event_disable(struct perf_event *event) |
d859e29f | 1591 | { |
cdd6c482 | 1592 | struct perf_event_context *ctx = event->ctx; |
d859e29f PM |
1593 | struct task_struct *task = ctx->task; |
1594 | ||
1595 | if (!task) { | |
1596 | /* | |
cdd6c482 | 1597 | * Disable the event on the cpu that it's on |
d859e29f | 1598 | */ |
fe4b04fa | 1599 | cpu_function_call(event->cpu, __perf_event_disable, event); |
d859e29f PM |
1600 | return; |
1601 | } | |
1602 | ||
9ed6060d | 1603 | retry: |
fe4b04fa PZ |
1604 | if (!task_function_call(task, __perf_event_disable, event)) |
1605 | return; | |
d859e29f | 1606 | |
e625cce1 | 1607 | raw_spin_lock_irq(&ctx->lock); |
d859e29f | 1608 | /* |
cdd6c482 | 1609 | * If the event is still active, we need to retry the cross-call. |
d859e29f | 1610 | */ |
cdd6c482 | 1611 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
e625cce1 | 1612 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa PZ |
1613 | /* |
1614 | * Reload the task pointer, it might have been changed by | |
1615 | * a concurrent perf_event_context_sched_out(). | |
1616 | */ | |
1617 | task = ctx->task; | |
d859e29f PM |
1618 | goto retry; |
1619 | } | |
1620 | ||
1621 | /* | |
1622 | * Since we have the lock this context can't be scheduled | |
1623 | * in, so we can change the state safely. | |
1624 | */ | |
cdd6c482 IM |
1625 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
1626 | update_group_times(event); | |
1627 | event->state = PERF_EVENT_STATE_OFF; | |
53cfbf59 | 1628 | } |
e625cce1 | 1629 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f | 1630 | } |
dcfce4a0 | 1631 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1632 | |
e5d1367f SE |
1633 | static void perf_set_shadow_time(struct perf_event *event, |
1634 | struct perf_event_context *ctx, | |
1635 | u64 tstamp) | |
1636 | { | |
1637 | /* | |
1638 | * use the correct time source for the time snapshot | |
1639 | * | |
1640 | * We could get by without this by leveraging the | |
1641 | * fact that to get to this function, the caller | |
1642 | * has most likely already called update_context_time() | |
1643 | * and update_cgrp_time_xx() and thus both timestamp | |
1644 | * are identical (or very close). Given that tstamp is, | |
1645 | * already adjusted for cgroup, we could say that: | |
1646 | * tstamp - ctx->timestamp | |
1647 | * is equivalent to | |
1648 | * tstamp - cgrp->timestamp. | |
1649 | * | |
1650 | * Then, in perf_output_read(), the calculation would | |
1651 | * work with no changes because: | |
1652 | * - event is guaranteed scheduled in | |
1653 | * - no scheduled out in between | |
1654 | * - thus the timestamp would be the same | |
1655 | * | |
1656 | * But this is a bit hairy. | |
1657 | * | |
1658 | * So instead, we have an explicit cgroup call to remain | |
1659 | * within the time time source all along. We believe it | |
1660 | * is cleaner and simpler to understand. | |
1661 | */ | |
1662 | if (is_cgroup_event(event)) | |
1663 | perf_cgroup_set_shadow_time(event, tstamp); | |
1664 | else | |
1665 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1666 | } | |
1667 | ||
4fe757dd PZ |
1668 | #define MAX_INTERRUPTS (~0ULL) |
1669 | ||
1670 | static void perf_log_throttle(struct perf_event *event, int enable); | |
1671 | ||
235c7fc7 | 1672 | static int |
9ffcfa6f | 1673 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1674 | struct perf_cpu_context *cpuctx, |
6e37738a | 1675 | struct perf_event_context *ctx) |
235c7fc7 | 1676 | { |
4158755d | 1677 | u64 tstamp = perf_event_time(event); |
44377277 | 1678 | int ret = 0; |
4158755d | 1679 | |
cdd6c482 | 1680 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1681 | return 0; |
1682 | ||
cdd6c482 | 1683 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1684 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1685 | |
1686 | /* | |
1687 | * Unthrottle events, since we scheduled we might have missed several | |
1688 | * ticks already, also for a heavily scheduling task there is little | |
1689 | * guarantee it'll get a tick in a timely manner. | |
1690 | */ | |
1691 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1692 | perf_log_throttle(event, 1); | |
1693 | event->hw.interrupts = 0; | |
1694 | } | |
1695 | ||
235c7fc7 IM |
1696 | /* |
1697 | * The new state must be visible before we turn it on in the hardware: | |
1698 | */ | |
1699 | smp_wmb(); | |
1700 | ||
44377277 AS |
1701 | perf_pmu_disable(event->pmu); |
1702 | ||
a4eaf7f1 | 1703 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1704 | event->state = PERF_EVENT_STATE_INACTIVE; |
1705 | event->oncpu = -1; | |
44377277 AS |
1706 | ret = -EAGAIN; |
1707 | goto out; | |
235c7fc7 IM |
1708 | } |
1709 | ||
4158755d | 1710 | event->tstamp_running += tstamp - event->tstamp_stopped; |
9ffcfa6f | 1711 | |
e5d1367f | 1712 | perf_set_shadow_time(event, ctx, tstamp); |
eed01528 | 1713 | |
cdd6c482 | 1714 | if (!is_software_event(event)) |
3b6f9e5c | 1715 | cpuctx->active_oncpu++; |
235c7fc7 | 1716 | ctx->nr_active++; |
0f5a2601 PZ |
1717 | if (event->attr.freq && event->attr.sample_freq) |
1718 | ctx->nr_freq++; | |
235c7fc7 | 1719 | |
cdd6c482 | 1720 | if (event->attr.exclusive) |
3b6f9e5c PM |
1721 | cpuctx->exclusive = 1; |
1722 | ||
44377277 AS |
1723 | out: |
1724 | perf_pmu_enable(event->pmu); | |
1725 | ||
1726 | return ret; | |
235c7fc7 IM |
1727 | } |
1728 | ||
6751b71e | 1729 | static int |
cdd6c482 | 1730 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1731 | struct perf_cpu_context *cpuctx, |
6e37738a | 1732 | struct perf_event_context *ctx) |
6751b71e | 1733 | { |
6bde9b6c | 1734 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1735 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1736 | u64 now = ctx->time; |
1737 | bool simulate = false; | |
6751b71e | 1738 | |
cdd6c482 | 1739 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1740 | return 0; |
1741 | ||
ad5133b7 | 1742 | pmu->start_txn(pmu); |
6bde9b6c | 1743 | |
9ffcfa6f | 1744 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1745 | pmu->cancel_txn(pmu); |
9e630205 | 1746 | perf_cpu_hrtimer_restart(cpuctx); |
6751b71e | 1747 | return -EAGAIN; |
90151c35 | 1748 | } |
6751b71e PM |
1749 | |
1750 | /* | |
1751 | * Schedule in siblings as one group (if any): | |
1752 | */ | |
cdd6c482 | 1753 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1754 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1755 | partial_group = event; |
6751b71e PM |
1756 | goto group_error; |
1757 | } | |
1758 | } | |
1759 | ||
9ffcfa6f | 1760 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1761 | return 0; |
9ffcfa6f | 1762 | |
6751b71e PM |
1763 | group_error: |
1764 | /* | |
1765 | * Groups can be scheduled in as one unit only, so undo any | |
1766 | * partial group before returning: | |
d7842da4 SE |
1767 | * The events up to the failed event are scheduled out normally, |
1768 | * tstamp_stopped will be updated. | |
1769 | * | |
1770 | * The failed events and the remaining siblings need to have | |
1771 | * their timings updated as if they had gone thru event_sched_in() | |
1772 | * and event_sched_out(). This is required to get consistent timings | |
1773 | * across the group. This also takes care of the case where the group | |
1774 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1775 | * the time the event was actually stopped, such that time delta | |
1776 | * calculation in update_event_times() is correct. | |
6751b71e | 1777 | */ |
cdd6c482 IM |
1778 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
1779 | if (event == partial_group) | |
d7842da4 SE |
1780 | simulate = true; |
1781 | ||
1782 | if (simulate) { | |
1783 | event->tstamp_running += now - event->tstamp_stopped; | |
1784 | event->tstamp_stopped = now; | |
1785 | } else { | |
1786 | event_sched_out(event, cpuctx, ctx); | |
1787 | } | |
6751b71e | 1788 | } |
9ffcfa6f | 1789 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 1790 | |
ad5133b7 | 1791 | pmu->cancel_txn(pmu); |
90151c35 | 1792 | |
9e630205 SE |
1793 | perf_cpu_hrtimer_restart(cpuctx); |
1794 | ||
6751b71e PM |
1795 | return -EAGAIN; |
1796 | } | |
1797 | ||
3b6f9e5c | 1798 | /* |
cdd6c482 | 1799 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 1800 | */ |
cdd6c482 | 1801 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
1802 | struct perf_cpu_context *cpuctx, |
1803 | int can_add_hw) | |
1804 | { | |
1805 | /* | |
cdd6c482 | 1806 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 1807 | */ |
d6f962b5 | 1808 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
1809 | return 1; |
1810 | /* | |
1811 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 1812 | * events can go on. |
3b6f9e5c PM |
1813 | */ |
1814 | if (cpuctx->exclusive) | |
1815 | return 0; | |
1816 | /* | |
1817 | * If this group is exclusive and there are already | |
cdd6c482 | 1818 | * events on the CPU, it can't go on. |
3b6f9e5c | 1819 | */ |
cdd6c482 | 1820 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
1821 | return 0; |
1822 | /* | |
1823 | * Otherwise, try to add it if all previous groups were able | |
1824 | * to go on. | |
1825 | */ | |
1826 | return can_add_hw; | |
1827 | } | |
1828 | ||
cdd6c482 IM |
1829 | static void add_event_to_ctx(struct perf_event *event, |
1830 | struct perf_event_context *ctx) | |
53cfbf59 | 1831 | { |
4158755d SE |
1832 | u64 tstamp = perf_event_time(event); |
1833 | ||
cdd6c482 | 1834 | list_add_event(event, ctx); |
8a49542c | 1835 | perf_group_attach(event); |
4158755d SE |
1836 | event->tstamp_enabled = tstamp; |
1837 | event->tstamp_running = tstamp; | |
1838 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
1839 | } |
1840 | ||
2c29ef0f PZ |
1841 | static void task_ctx_sched_out(struct perf_event_context *ctx); |
1842 | static void | |
1843 | ctx_sched_in(struct perf_event_context *ctx, | |
1844 | struct perf_cpu_context *cpuctx, | |
1845 | enum event_type_t event_type, | |
1846 | struct task_struct *task); | |
fe4b04fa | 1847 | |
dce5855b PZ |
1848 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
1849 | struct perf_event_context *ctx, | |
1850 | struct task_struct *task) | |
1851 | { | |
1852 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
1853 | if (ctx) | |
1854 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
1855 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
1856 | if (ctx) | |
1857 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
1858 | } | |
1859 | ||
0793a61d | 1860 | /* |
cdd6c482 | 1861 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
1862 | * |
1863 | * Must be called with ctx->mutex held | |
0793a61d | 1864 | */ |
fe4b04fa | 1865 | static int __perf_install_in_context(void *info) |
0793a61d | 1866 | { |
cdd6c482 IM |
1867 | struct perf_event *event = info; |
1868 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 1869 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f PZ |
1870 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
1871 | struct task_struct *task = current; | |
1872 | ||
b58f6b0d | 1873 | perf_ctx_lock(cpuctx, task_ctx); |
2c29ef0f | 1874 | perf_pmu_disable(cpuctx->ctx.pmu); |
0793a61d TG |
1875 | |
1876 | /* | |
2c29ef0f | 1877 | * If there was an active task_ctx schedule it out. |
0793a61d | 1878 | */ |
b58f6b0d | 1879 | if (task_ctx) |
2c29ef0f | 1880 | task_ctx_sched_out(task_ctx); |
b58f6b0d PZ |
1881 | |
1882 | /* | |
1883 | * If the context we're installing events in is not the | |
1884 | * active task_ctx, flip them. | |
1885 | */ | |
1886 | if (ctx->task && task_ctx != ctx) { | |
1887 | if (task_ctx) | |
1888 | raw_spin_unlock(&task_ctx->lock); | |
1889 | raw_spin_lock(&ctx->lock); | |
1890 | task_ctx = ctx; | |
1891 | } | |
1892 | ||
1893 | if (task_ctx) { | |
1894 | cpuctx->task_ctx = task_ctx; | |
2c29ef0f PZ |
1895 | task = task_ctx->task; |
1896 | } | |
b58f6b0d | 1897 | |
2c29ef0f | 1898 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); |
0793a61d | 1899 | |
4af4998b | 1900 | update_context_time(ctx); |
e5d1367f SE |
1901 | /* |
1902 | * update cgrp time only if current cgrp | |
1903 | * matches event->cgrp. Must be done before | |
1904 | * calling add_event_to_ctx() | |
1905 | */ | |
1906 | update_cgrp_time_from_event(event); | |
0793a61d | 1907 | |
cdd6c482 | 1908 | add_event_to_ctx(event, ctx); |
0793a61d | 1909 | |
d859e29f | 1910 | /* |
2c29ef0f | 1911 | * Schedule everything back in |
d859e29f | 1912 | */ |
dce5855b | 1913 | perf_event_sched_in(cpuctx, task_ctx, task); |
2c29ef0f PZ |
1914 | |
1915 | perf_pmu_enable(cpuctx->ctx.pmu); | |
1916 | perf_ctx_unlock(cpuctx, task_ctx); | |
fe4b04fa PZ |
1917 | |
1918 | return 0; | |
0793a61d TG |
1919 | } |
1920 | ||
1921 | /* | |
cdd6c482 | 1922 | * Attach a performance event to a context |
0793a61d | 1923 | * |
cdd6c482 IM |
1924 | * First we add the event to the list with the hardware enable bit |
1925 | * in event->hw_config cleared. | |
0793a61d | 1926 | * |
cdd6c482 | 1927 | * If the event is attached to a task which is on a CPU we use a smp |
0793a61d TG |
1928 | * call to enable it in the task context. The task might have been |
1929 | * scheduled away, but we check this in the smp call again. | |
1930 | */ | |
1931 | static void | |
cdd6c482 IM |
1932 | perf_install_in_context(struct perf_event_context *ctx, |
1933 | struct perf_event *event, | |
0793a61d TG |
1934 | int cpu) |
1935 | { | |
1936 | struct task_struct *task = ctx->task; | |
1937 | ||
fe4b04fa PZ |
1938 | lockdep_assert_held(&ctx->mutex); |
1939 | ||
c3f00c70 | 1940 | event->ctx = ctx; |
0cda4c02 YZ |
1941 | if (event->cpu != -1) |
1942 | event->cpu = cpu; | |
c3f00c70 | 1943 | |
0793a61d TG |
1944 | if (!task) { |
1945 | /* | |
cdd6c482 | 1946 | * Per cpu events are installed via an smp call and |
af901ca1 | 1947 | * the install is always successful. |
0793a61d | 1948 | */ |
fe4b04fa | 1949 | cpu_function_call(cpu, __perf_install_in_context, event); |
0793a61d TG |
1950 | return; |
1951 | } | |
1952 | ||
0793a61d | 1953 | retry: |
fe4b04fa PZ |
1954 | if (!task_function_call(task, __perf_install_in_context, event)) |
1955 | return; | |
0793a61d | 1956 | |
e625cce1 | 1957 | raw_spin_lock_irq(&ctx->lock); |
0793a61d | 1958 | /* |
fe4b04fa PZ |
1959 | * If we failed to find a running task, but find the context active now |
1960 | * that we've acquired the ctx->lock, retry. | |
0793a61d | 1961 | */ |
fe4b04fa | 1962 | if (ctx->is_active) { |
e625cce1 | 1963 | raw_spin_unlock_irq(&ctx->lock); |
0793a61d TG |
1964 | goto retry; |
1965 | } | |
1966 | ||
1967 | /* | |
fe4b04fa PZ |
1968 | * Since the task isn't running, its safe to add the event, us holding |
1969 | * the ctx->lock ensures the task won't get scheduled in. | |
0793a61d | 1970 | */ |
fe4b04fa | 1971 | add_event_to_ctx(event, ctx); |
e625cce1 | 1972 | raw_spin_unlock_irq(&ctx->lock); |
0793a61d TG |
1973 | } |
1974 | ||
fa289bec | 1975 | /* |
cdd6c482 | 1976 | * Put a event into inactive state and update time fields. |
fa289bec PM |
1977 | * Enabling the leader of a group effectively enables all |
1978 | * the group members that aren't explicitly disabled, so we | |
1979 | * have to update their ->tstamp_enabled also. | |
1980 | * Note: this works for group members as well as group leaders | |
1981 | * since the non-leader members' sibling_lists will be empty. | |
1982 | */ | |
1d9b482e | 1983 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 1984 | { |
cdd6c482 | 1985 | struct perf_event *sub; |
4158755d | 1986 | u64 tstamp = perf_event_time(event); |
fa289bec | 1987 | |
cdd6c482 | 1988 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 1989 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 1990 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
1991 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
1992 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 1993 | } |
fa289bec PM |
1994 | } |
1995 | ||
d859e29f | 1996 | /* |
cdd6c482 | 1997 | * Cross CPU call to enable a performance event |
d859e29f | 1998 | */ |
fe4b04fa | 1999 | static int __perf_event_enable(void *info) |
04289bb9 | 2000 | { |
cdd6c482 | 2001 | struct perf_event *event = info; |
cdd6c482 IM |
2002 | struct perf_event_context *ctx = event->ctx; |
2003 | struct perf_event *leader = event->group_leader; | |
108b02cf | 2004 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f | 2005 | int err; |
04289bb9 | 2006 | |
06f41796 JO |
2007 | /* |
2008 | * There's a time window between 'ctx->is_active' check | |
2009 | * in perf_event_enable function and this place having: | |
2010 | * - IRQs on | |
2011 | * - ctx->lock unlocked | |
2012 | * | |
2013 | * where the task could be killed and 'ctx' deactivated | |
2014 | * by perf_event_exit_task. | |
2015 | */ | |
2016 | if (!ctx->is_active) | |
fe4b04fa | 2017 | return -EINVAL; |
3cbed429 | 2018 | |
e625cce1 | 2019 | raw_spin_lock(&ctx->lock); |
4af4998b | 2020 | update_context_time(ctx); |
d859e29f | 2021 | |
cdd6c482 | 2022 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f | 2023 | goto unlock; |
e5d1367f SE |
2024 | |
2025 | /* | |
2026 | * set current task's cgroup time reference point | |
2027 | */ | |
3f7cce3c | 2028 | perf_cgroup_set_timestamp(current, ctx); |
e5d1367f | 2029 | |
1d9b482e | 2030 | __perf_event_mark_enabled(event); |
04289bb9 | 2031 | |
e5d1367f SE |
2032 | if (!event_filter_match(event)) { |
2033 | if (is_cgroup_event(event)) | |
2034 | perf_cgroup_defer_enabled(event); | |
f4c4176f | 2035 | goto unlock; |
e5d1367f | 2036 | } |
f4c4176f | 2037 | |
04289bb9 | 2038 | /* |
cdd6c482 | 2039 | * If the event is in a group and isn't the group leader, |
d859e29f | 2040 | * then don't put it on unless the group is on. |
04289bb9 | 2041 | */ |
cdd6c482 | 2042 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
d859e29f | 2043 | goto unlock; |
3b6f9e5c | 2044 | |
cdd6c482 | 2045 | if (!group_can_go_on(event, cpuctx, 1)) { |
d859e29f | 2046 | err = -EEXIST; |
e758a33d | 2047 | } else { |
cdd6c482 | 2048 | if (event == leader) |
6e37738a | 2049 | err = group_sched_in(event, cpuctx, ctx); |
e758a33d | 2050 | else |
6e37738a | 2051 | err = event_sched_in(event, cpuctx, ctx); |
e758a33d | 2052 | } |
d859e29f PM |
2053 | |
2054 | if (err) { | |
2055 | /* | |
cdd6c482 | 2056 | * If this event can't go on and it's part of a |
d859e29f PM |
2057 | * group, then the whole group has to come off. |
2058 | */ | |
9e630205 | 2059 | if (leader != event) { |
d859e29f | 2060 | group_sched_out(leader, cpuctx, ctx); |
9e630205 SE |
2061 | perf_cpu_hrtimer_restart(cpuctx); |
2062 | } | |
0d48696f | 2063 | if (leader->attr.pinned) { |
53cfbf59 | 2064 | update_group_times(leader); |
cdd6c482 | 2065 | leader->state = PERF_EVENT_STATE_ERROR; |
53cfbf59 | 2066 | } |
d859e29f PM |
2067 | } |
2068 | ||
9ed6060d | 2069 | unlock: |
e625cce1 | 2070 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
2071 | |
2072 | return 0; | |
d859e29f PM |
2073 | } |
2074 | ||
2075 | /* | |
cdd6c482 | 2076 | * Enable a event. |
c93f7669 | 2077 | * |
cdd6c482 IM |
2078 | * If event->ctx is a cloned context, callers must make sure that |
2079 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2080 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2081 | * perf_event_for_each_child or perf_event_for_each as described |
2082 | * for perf_event_disable. | |
d859e29f | 2083 | */ |
44234adc | 2084 | void perf_event_enable(struct perf_event *event) |
d859e29f | 2085 | { |
cdd6c482 | 2086 | struct perf_event_context *ctx = event->ctx; |
d859e29f PM |
2087 | struct task_struct *task = ctx->task; |
2088 | ||
2089 | if (!task) { | |
2090 | /* | |
cdd6c482 | 2091 | * Enable the event on the cpu that it's on |
d859e29f | 2092 | */ |
fe4b04fa | 2093 | cpu_function_call(event->cpu, __perf_event_enable, event); |
d859e29f PM |
2094 | return; |
2095 | } | |
2096 | ||
e625cce1 | 2097 | raw_spin_lock_irq(&ctx->lock); |
cdd6c482 | 2098 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f PM |
2099 | goto out; |
2100 | ||
2101 | /* | |
cdd6c482 IM |
2102 | * If the event is in error state, clear that first. |
2103 | * That way, if we see the event in error state below, we | |
d859e29f PM |
2104 | * know that it has gone back into error state, as distinct |
2105 | * from the task having been scheduled away before the | |
2106 | * cross-call arrived. | |
2107 | */ | |
cdd6c482 IM |
2108 | if (event->state == PERF_EVENT_STATE_ERROR) |
2109 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f | 2110 | |
9ed6060d | 2111 | retry: |
fe4b04fa | 2112 | if (!ctx->is_active) { |
1d9b482e | 2113 | __perf_event_mark_enabled(event); |
fe4b04fa PZ |
2114 | goto out; |
2115 | } | |
2116 | ||
e625cce1 | 2117 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa PZ |
2118 | |
2119 | if (!task_function_call(task, __perf_event_enable, event)) | |
2120 | return; | |
d859e29f | 2121 | |
e625cce1 | 2122 | raw_spin_lock_irq(&ctx->lock); |
d859e29f PM |
2123 | |
2124 | /* | |
cdd6c482 | 2125 | * If the context is active and the event is still off, |
d859e29f PM |
2126 | * we need to retry the cross-call. |
2127 | */ | |
fe4b04fa PZ |
2128 | if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) { |
2129 | /* | |
2130 | * task could have been flipped by a concurrent | |
2131 | * perf_event_context_sched_out() | |
2132 | */ | |
2133 | task = ctx->task; | |
d859e29f | 2134 | goto retry; |
fe4b04fa | 2135 | } |
fa289bec | 2136 | |
9ed6060d | 2137 | out: |
e625cce1 | 2138 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f | 2139 | } |
dcfce4a0 | 2140 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2141 | |
26ca5c11 | 2142 | int perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2143 | { |
2023b359 | 2144 | /* |
cdd6c482 | 2145 | * not supported on inherited events |
2023b359 | 2146 | */ |
2e939d1d | 2147 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2148 | return -EINVAL; |
2149 | ||
cdd6c482 IM |
2150 | atomic_add(refresh, &event->event_limit); |
2151 | perf_event_enable(event); | |
2023b359 PZ |
2152 | |
2153 | return 0; | |
79f14641 | 2154 | } |
26ca5c11 | 2155 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2156 | |
5b0311e1 FW |
2157 | static void ctx_sched_out(struct perf_event_context *ctx, |
2158 | struct perf_cpu_context *cpuctx, | |
2159 | enum event_type_t event_type) | |
235c7fc7 | 2160 | { |
cdd6c482 | 2161 | struct perf_event *event; |
db24d33e | 2162 | int is_active = ctx->is_active; |
235c7fc7 | 2163 | |
db24d33e | 2164 | ctx->is_active &= ~event_type; |
cdd6c482 | 2165 | if (likely(!ctx->nr_events)) |
facc4307 PZ |
2166 | return; |
2167 | ||
4af4998b | 2168 | update_context_time(ctx); |
e5d1367f | 2169 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2170 | if (!ctx->nr_active) |
facc4307 | 2171 | return; |
5b0311e1 | 2172 | |
075e0b00 | 2173 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2174 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2175 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2176 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2177 | } |
889ff015 | 2178 | |
db24d33e | 2179 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2180 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2181 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2182 | } |
1b9a644f | 2183 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2184 | } |
2185 | ||
564c2b21 | 2186 | /* |
5a3126d4 PZ |
2187 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2188 | * cloned from the same version of the same context. | |
2189 | * | |
2190 | * Equivalence is measured using a generation number in the context that is | |
2191 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2192 | * and list_del_event(). | |
564c2b21 | 2193 | */ |
cdd6c482 IM |
2194 | static int context_equiv(struct perf_event_context *ctx1, |
2195 | struct perf_event_context *ctx2) | |
564c2b21 | 2196 | { |
5a3126d4 PZ |
2197 | /* Pinning disables the swap optimization */ |
2198 | if (ctx1->pin_count || ctx2->pin_count) | |
2199 | return 0; | |
2200 | ||
2201 | /* If ctx1 is the parent of ctx2 */ | |
2202 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2203 | return 1; | |
2204 | ||
2205 | /* If ctx2 is the parent of ctx1 */ | |
2206 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2207 | return 1; | |
2208 | ||
2209 | /* | |
2210 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2211 | * hierarchy, see perf_event_init_context(). | |
2212 | */ | |
2213 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2214 | ctx1->parent_gen == ctx2->parent_gen) | |
2215 | return 1; | |
2216 | ||
2217 | /* Unmatched */ | |
2218 | return 0; | |
564c2b21 PM |
2219 | } |
2220 | ||
cdd6c482 IM |
2221 | static void __perf_event_sync_stat(struct perf_event *event, |
2222 | struct perf_event *next_event) | |
bfbd3381 PZ |
2223 | { |
2224 | u64 value; | |
2225 | ||
cdd6c482 | 2226 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2227 | return; |
2228 | ||
2229 | /* | |
cdd6c482 | 2230 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2231 | * because we're in the middle of a context switch and have IRQs |
2232 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2233 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2234 | * don't need to use it. |
2235 | */ | |
cdd6c482 IM |
2236 | switch (event->state) { |
2237 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2238 | event->pmu->read(event); |
2239 | /* fall-through */ | |
bfbd3381 | 2240 | |
cdd6c482 IM |
2241 | case PERF_EVENT_STATE_INACTIVE: |
2242 | update_event_times(event); | |
bfbd3381 PZ |
2243 | break; |
2244 | ||
2245 | default: | |
2246 | break; | |
2247 | } | |
2248 | ||
2249 | /* | |
cdd6c482 | 2250 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2251 | * values when we flip the contexts. |
2252 | */ | |
e7850595 PZ |
2253 | value = local64_read(&next_event->count); |
2254 | value = local64_xchg(&event->count, value); | |
2255 | local64_set(&next_event->count, value); | |
bfbd3381 | 2256 | |
cdd6c482 IM |
2257 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2258 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2259 | |
bfbd3381 | 2260 | /* |
19d2e755 | 2261 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2262 | */ |
cdd6c482 IM |
2263 | perf_event_update_userpage(event); |
2264 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2265 | } |
2266 | ||
cdd6c482 IM |
2267 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2268 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2269 | { |
cdd6c482 | 2270 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2271 | |
2272 | if (!ctx->nr_stat) | |
2273 | return; | |
2274 | ||
02ffdbc8 PZ |
2275 | update_context_time(ctx); |
2276 | ||
cdd6c482 IM |
2277 | event = list_first_entry(&ctx->event_list, |
2278 | struct perf_event, event_entry); | |
bfbd3381 | 2279 | |
cdd6c482 IM |
2280 | next_event = list_first_entry(&next_ctx->event_list, |
2281 | struct perf_event, event_entry); | |
bfbd3381 | 2282 | |
cdd6c482 IM |
2283 | while (&event->event_entry != &ctx->event_list && |
2284 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2285 | |
cdd6c482 | 2286 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2287 | |
cdd6c482 IM |
2288 | event = list_next_entry(event, event_entry); |
2289 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2290 | } |
2291 | } | |
2292 | ||
fe4b04fa PZ |
2293 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2294 | struct task_struct *next) | |
0793a61d | 2295 | { |
8dc85d54 | 2296 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2297 | struct perf_event_context *next_ctx; |
5a3126d4 | 2298 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2299 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2300 | int do_switch = 1; |
0793a61d | 2301 | |
108b02cf PZ |
2302 | if (likely(!ctx)) |
2303 | return; | |
10989fb2 | 2304 | |
108b02cf PZ |
2305 | cpuctx = __get_cpu_context(ctx); |
2306 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2307 | return; |
2308 | ||
c93f7669 | 2309 | rcu_read_lock(); |
8dc85d54 | 2310 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2311 | if (!next_ctx) |
2312 | goto unlock; | |
2313 | ||
2314 | parent = rcu_dereference(ctx->parent_ctx); | |
2315 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2316 | ||
2317 | /* If neither context have a parent context; they cannot be clones. */ | |
2318 | if (!parent && !next_parent) | |
2319 | goto unlock; | |
2320 | ||
2321 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2322 | /* |
2323 | * Looks like the two contexts are clones, so we might be | |
2324 | * able to optimize the context switch. We lock both | |
2325 | * contexts and check that they are clones under the | |
2326 | * lock (including re-checking that neither has been | |
2327 | * uncloned in the meantime). It doesn't matter which | |
2328 | * order we take the locks because no other cpu could | |
2329 | * be trying to lock both of these tasks. | |
2330 | */ | |
e625cce1 TG |
2331 | raw_spin_lock(&ctx->lock); |
2332 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2333 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2334 | /* |
2335 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2336 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2337 | */ |
8dc85d54 PZ |
2338 | task->perf_event_ctxp[ctxn] = next_ctx; |
2339 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2340 | ctx->task = next; |
2341 | next_ctx->task = task; | |
2342 | do_switch = 0; | |
bfbd3381 | 2343 | |
cdd6c482 | 2344 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2345 | } |
e625cce1 TG |
2346 | raw_spin_unlock(&next_ctx->lock); |
2347 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2348 | } |
5a3126d4 | 2349 | unlock: |
c93f7669 | 2350 | rcu_read_unlock(); |
564c2b21 | 2351 | |
c93f7669 | 2352 | if (do_switch) { |
facc4307 | 2353 | raw_spin_lock(&ctx->lock); |
5b0311e1 | 2354 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
c93f7669 | 2355 | cpuctx->task_ctx = NULL; |
facc4307 | 2356 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2357 | } |
0793a61d TG |
2358 | } |
2359 | ||
8dc85d54 PZ |
2360 | #define for_each_task_context_nr(ctxn) \ |
2361 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2362 | ||
2363 | /* | |
2364 | * Called from scheduler to remove the events of the current task, | |
2365 | * with interrupts disabled. | |
2366 | * | |
2367 | * We stop each event and update the event value in event->count. | |
2368 | * | |
2369 | * This does not protect us against NMI, but disable() | |
2370 | * sets the disabled bit in the control field of event _before_ | |
2371 | * accessing the event control register. If a NMI hits, then it will | |
2372 | * not restart the event. | |
2373 | */ | |
ab0cce56 JO |
2374 | void __perf_event_task_sched_out(struct task_struct *task, |
2375 | struct task_struct *next) | |
8dc85d54 PZ |
2376 | { |
2377 | int ctxn; | |
2378 | ||
8dc85d54 PZ |
2379 | for_each_task_context_nr(ctxn) |
2380 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2381 | |
2382 | /* | |
2383 | * if cgroup events exist on this CPU, then we need | |
2384 | * to check if we have to switch out PMU state. | |
2385 | * cgroup event are system-wide mode only | |
2386 | */ | |
2387 | if (atomic_read(&__get_cpu_var(perf_cgroup_events))) | |
a8d757ef | 2388 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2389 | } |
2390 | ||
04dc2dbb | 2391 | static void task_ctx_sched_out(struct perf_event_context *ctx) |
a08b159f | 2392 | { |
108b02cf | 2393 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
a08b159f | 2394 | |
a63eaf34 PM |
2395 | if (!cpuctx->task_ctx) |
2396 | return; | |
012b84da IM |
2397 | |
2398 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2399 | return; | |
2400 | ||
04dc2dbb | 2401 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2402 | cpuctx->task_ctx = NULL; |
2403 | } | |
2404 | ||
5b0311e1 FW |
2405 | /* |
2406 | * Called with IRQs disabled | |
2407 | */ | |
2408 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2409 | enum event_type_t event_type) | |
2410 | { | |
2411 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2412 | } |
2413 | ||
235c7fc7 | 2414 | static void |
5b0311e1 | 2415 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2416 | struct perf_cpu_context *cpuctx) |
0793a61d | 2417 | { |
cdd6c482 | 2418 | struct perf_event *event; |
0793a61d | 2419 | |
889ff015 FW |
2420 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2421 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2422 | continue; |
5632ab12 | 2423 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2424 | continue; |
2425 | ||
e5d1367f SE |
2426 | /* may need to reset tstamp_enabled */ |
2427 | if (is_cgroup_event(event)) | |
2428 | perf_cgroup_mark_enabled(event, ctx); | |
2429 | ||
8c9ed8e1 | 2430 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2431 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2432 | |
2433 | /* | |
2434 | * If this pinned group hasn't been scheduled, | |
2435 | * put it in error state. | |
2436 | */ | |
cdd6c482 IM |
2437 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2438 | update_group_times(event); | |
2439 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2440 | } |
3b6f9e5c | 2441 | } |
5b0311e1 FW |
2442 | } |
2443 | ||
2444 | static void | |
2445 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2446 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2447 | { |
2448 | struct perf_event *event; | |
2449 | int can_add_hw = 1; | |
3b6f9e5c | 2450 | |
889ff015 FW |
2451 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2452 | /* Ignore events in OFF or ERROR state */ | |
2453 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2454 | continue; |
04289bb9 IM |
2455 | /* |
2456 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2457 | * of events: |
04289bb9 | 2458 | */ |
5632ab12 | 2459 | if (!event_filter_match(event)) |
0793a61d TG |
2460 | continue; |
2461 | ||
e5d1367f SE |
2462 | /* may need to reset tstamp_enabled */ |
2463 | if (is_cgroup_event(event)) | |
2464 | perf_cgroup_mark_enabled(event, ctx); | |
2465 | ||
9ed6060d | 2466 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2467 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2468 | can_add_hw = 0; |
9ed6060d | 2469 | } |
0793a61d | 2470 | } |
5b0311e1 FW |
2471 | } |
2472 | ||
2473 | static void | |
2474 | ctx_sched_in(struct perf_event_context *ctx, | |
2475 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2476 | enum event_type_t event_type, |
2477 | struct task_struct *task) | |
5b0311e1 | 2478 | { |
e5d1367f | 2479 | u64 now; |
db24d33e | 2480 | int is_active = ctx->is_active; |
e5d1367f | 2481 | |
db24d33e | 2482 | ctx->is_active |= event_type; |
5b0311e1 | 2483 | if (likely(!ctx->nr_events)) |
facc4307 | 2484 | return; |
5b0311e1 | 2485 | |
e5d1367f SE |
2486 | now = perf_clock(); |
2487 | ctx->timestamp = now; | |
3f7cce3c | 2488 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2489 | /* |
2490 | * First go through the list and put on any pinned groups | |
2491 | * in order to give them the best chance of going on. | |
2492 | */ | |
db24d33e | 2493 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2494 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2495 | |
2496 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2497 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2498 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2499 | } |
2500 | ||
329c0e01 | 2501 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2502 | enum event_type_t event_type, |
2503 | struct task_struct *task) | |
329c0e01 FW |
2504 | { |
2505 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2506 | ||
e5d1367f | 2507 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2508 | } |
2509 | ||
e5d1367f SE |
2510 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2511 | struct task_struct *task) | |
235c7fc7 | 2512 | { |
108b02cf | 2513 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2514 | |
108b02cf | 2515 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2516 | if (cpuctx->task_ctx == ctx) |
2517 | return; | |
2518 | ||
facc4307 | 2519 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2520 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2521 | /* |
2522 | * We want to keep the following priority order: | |
2523 | * cpu pinned (that don't need to move), task pinned, | |
2524 | * cpu flexible, task flexible. | |
2525 | */ | |
2526 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2527 | ||
1d5f003f GN |
2528 | if (ctx->nr_events) |
2529 | cpuctx->task_ctx = ctx; | |
9b33fa6b | 2530 | |
86b47c25 GN |
2531 | perf_event_sched_in(cpuctx, cpuctx->task_ctx, task); |
2532 | ||
facc4307 PZ |
2533 | perf_pmu_enable(ctx->pmu); |
2534 | perf_ctx_unlock(cpuctx, ctx); | |
2535 | ||
b5ab4cd5 PZ |
2536 | /* |
2537 | * Since these rotations are per-cpu, we need to ensure the | |
2538 | * cpu-context we got scheduled on is actually rotating. | |
2539 | */ | |
108b02cf | 2540 | perf_pmu_rotate_start(ctx->pmu); |
235c7fc7 IM |
2541 | } |
2542 | ||
d010b332 SE |
2543 | /* |
2544 | * When sampling the branck stack in system-wide, it may be necessary | |
2545 | * to flush the stack on context switch. This happens when the branch | |
2546 | * stack does not tag its entries with the pid of the current task. | |
2547 | * Otherwise it becomes impossible to associate a branch entry with a | |
2548 | * task. This ambiguity is more likely to appear when the branch stack | |
2549 | * supports priv level filtering and the user sets it to monitor only | |
2550 | * at the user level (which could be a useful measurement in system-wide | |
2551 | * mode). In that case, the risk is high of having a branch stack with | |
2552 | * branch from multiple tasks. Flushing may mean dropping the existing | |
2553 | * entries or stashing them somewhere in the PMU specific code layer. | |
2554 | * | |
2555 | * This function provides the context switch callback to the lower code | |
2556 | * layer. It is invoked ONLY when there is at least one system-wide context | |
2557 | * with at least one active event using taken branch sampling. | |
2558 | */ | |
2559 | static void perf_branch_stack_sched_in(struct task_struct *prev, | |
2560 | struct task_struct *task) | |
2561 | { | |
2562 | struct perf_cpu_context *cpuctx; | |
2563 | struct pmu *pmu; | |
2564 | unsigned long flags; | |
2565 | ||
2566 | /* no need to flush branch stack if not changing task */ | |
2567 | if (prev == task) | |
2568 | return; | |
2569 | ||
2570 | local_irq_save(flags); | |
2571 | ||
2572 | rcu_read_lock(); | |
2573 | ||
2574 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2575 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2576 | ||
2577 | /* | |
2578 | * check if the context has at least one | |
2579 | * event using PERF_SAMPLE_BRANCH_STACK | |
2580 | */ | |
2581 | if (cpuctx->ctx.nr_branch_stack > 0 | |
2582 | && pmu->flush_branch_stack) { | |
2583 | ||
d010b332 SE |
2584 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
2585 | ||
2586 | perf_pmu_disable(pmu); | |
2587 | ||
2588 | pmu->flush_branch_stack(); | |
2589 | ||
2590 | perf_pmu_enable(pmu); | |
2591 | ||
2592 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2593 | } | |
2594 | } | |
2595 | ||
2596 | rcu_read_unlock(); | |
2597 | ||
2598 | local_irq_restore(flags); | |
2599 | } | |
2600 | ||
8dc85d54 PZ |
2601 | /* |
2602 | * Called from scheduler to add the events of the current task | |
2603 | * with interrupts disabled. | |
2604 | * | |
2605 | * We restore the event value and then enable it. | |
2606 | * | |
2607 | * This does not protect us against NMI, but enable() | |
2608 | * sets the enabled bit in the control field of event _before_ | |
2609 | * accessing the event control register. If a NMI hits, then it will | |
2610 | * keep the event running. | |
2611 | */ | |
ab0cce56 JO |
2612 | void __perf_event_task_sched_in(struct task_struct *prev, |
2613 | struct task_struct *task) | |
8dc85d54 PZ |
2614 | { |
2615 | struct perf_event_context *ctx; | |
2616 | int ctxn; | |
2617 | ||
2618 | for_each_task_context_nr(ctxn) { | |
2619 | ctx = task->perf_event_ctxp[ctxn]; | |
2620 | if (likely(!ctx)) | |
2621 | continue; | |
2622 | ||
e5d1367f | 2623 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2624 | } |
e5d1367f SE |
2625 | /* |
2626 | * if cgroup events exist on this CPU, then we need | |
2627 | * to check if we have to switch in PMU state. | |
2628 | * cgroup event are system-wide mode only | |
2629 | */ | |
2630 | if (atomic_read(&__get_cpu_var(perf_cgroup_events))) | |
a8d757ef | 2631 | perf_cgroup_sched_in(prev, task); |
d010b332 SE |
2632 | |
2633 | /* check for system-wide branch_stack events */ | |
2634 | if (atomic_read(&__get_cpu_var(perf_branch_stack_events))) | |
2635 | perf_branch_stack_sched_in(prev, task); | |
235c7fc7 IM |
2636 | } |
2637 | ||
abd50713 PZ |
2638 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2639 | { | |
2640 | u64 frequency = event->attr.sample_freq; | |
2641 | u64 sec = NSEC_PER_SEC; | |
2642 | u64 divisor, dividend; | |
2643 | ||
2644 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2645 | ||
2646 | count_fls = fls64(count); | |
2647 | nsec_fls = fls64(nsec); | |
2648 | frequency_fls = fls64(frequency); | |
2649 | sec_fls = 30; | |
2650 | ||
2651 | /* | |
2652 | * We got @count in @nsec, with a target of sample_freq HZ | |
2653 | * the target period becomes: | |
2654 | * | |
2655 | * @count * 10^9 | |
2656 | * period = ------------------- | |
2657 | * @nsec * sample_freq | |
2658 | * | |
2659 | */ | |
2660 | ||
2661 | /* | |
2662 | * Reduce accuracy by one bit such that @a and @b converge | |
2663 | * to a similar magnitude. | |
2664 | */ | |
fe4b04fa | 2665 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2666 | do { \ |
2667 | if (a##_fls > b##_fls) { \ | |
2668 | a >>= 1; \ | |
2669 | a##_fls--; \ | |
2670 | } else { \ | |
2671 | b >>= 1; \ | |
2672 | b##_fls--; \ | |
2673 | } \ | |
2674 | } while (0) | |
2675 | ||
2676 | /* | |
2677 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2678 | * the other, so that finally we can do a u64/u64 division. | |
2679 | */ | |
2680 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2681 | REDUCE_FLS(nsec, frequency); | |
2682 | REDUCE_FLS(sec, count); | |
2683 | } | |
2684 | ||
2685 | if (count_fls + sec_fls > 64) { | |
2686 | divisor = nsec * frequency; | |
2687 | ||
2688 | while (count_fls + sec_fls > 64) { | |
2689 | REDUCE_FLS(count, sec); | |
2690 | divisor >>= 1; | |
2691 | } | |
2692 | ||
2693 | dividend = count * sec; | |
2694 | } else { | |
2695 | dividend = count * sec; | |
2696 | ||
2697 | while (nsec_fls + frequency_fls > 64) { | |
2698 | REDUCE_FLS(nsec, frequency); | |
2699 | dividend >>= 1; | |
2700 | } | |
2701 | ||
2702 | divisor = nsec * frequency; | |
2703 | } | |
2704 | ||
f6ab91ad PZ |
2705 | if (!divisor) |
2706 | return dividend; | |
2707 | ||
abd50713 PZ |
2708 | return div64_u64(dividend, divisor); |
2709 | } | |
2710 | ||
e050e3f0 SE |
2711 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2712 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2713 | ||
f39d47ff | 2714 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2715 | { |
cdd6c482 | 2716 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2717 | s64 period, sample_period; |
bd2b5b12 PZ |
2718 | s64 delta; |
2719 | ||
abd50713 | 2720 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2721 | |
2722 | delta = (s64)(period - hwc->sample_period); | |
2723 | delta = (delta + 7) / 8; /* low pass filter */ | |
2724 | ||
2725 | sample_period = hwc->sample_period + delta; | |
2726 | ||
2727 | if (!sample_period) | |
2728 | sample_period = 1; | |
2729 | ||
bd2b5b12 | 2730 | hwc->sample_period = sample_period; |
abd50713 | 2731 | |
e7850595 | 2732 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2733 | if (disable) |
2734 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2735 | ||
e7850595 | 2736 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2737 | |
2738 | if (disable) | |
2739 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2740 | } |
bd2b5b12 PZ |
2741 | } |
2742 | ||
e050e3f0 SE |
2743 | /* |
2744 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2745 | * events. At the same time, make sure, having freq events does not change | |
2746 | * the rate of unthrottling as that would introduce bias. | |
2747 | */ | |
2748 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2749 | int needs_unthr) | |
60db5e09 | 2750 | { |
cdd6c482 IM |
2751 | struct perf_event *event; |
2752 | struct hw_perf_event *hwc; | |
e050e3f0 | 2753 | u64 now, period = TICK_NSEC; |
abd50713 | 2754 | s64 delta; |
60db5e09 | 2755 | |
e050e3f0 SE |
2756 | /* |
2757 | * only need to iterate over all events iff: | |
2758 | * - context have events in frequency mode (needs freq adjust) | |
2759 | * - there are events to unthrottle on this cpu | |
2760 | */ | |
2761 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2762 | return; |
2763 | ||
e050e3f0 | 2764 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2765 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2766 | |
03541f8b | 2767 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2768 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2769 | continue; |
2770 | ||
5632ab12 | 2771 | if (!event_filter_match(event)) |
5d27c23d PZ |
2772 | continue; |
2773 | ||
44377277 AS |
2774 | perf_pmu_disable(event->pmu); |
2775 | ||
cdd6c482 | 2776 | hwc = &event->hw; |
6a24ed6c | 2777 | |
ae23bff1 | 2778 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2779 | hwc->interrupts = 0; |
cdd6c482 | 2780 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2781 | event->pmu->start(event, 0); |
a78ac325 PZ |
2782 | } |
2783 | ||
cdd6c482 | 2784 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2785 | goto next; |
60db5e09 | 2786 | |
e050e3f0 SE |
2787 | /* |
2788 | * stop the event and update event->count | |
2789 | */ | |
2790 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2791 | ||
e7850595 | 2792 | now = local64_read(&event->count); |
abd50713 PZ |
2793 | delta = now - hwc->freq_count_stamp; |
2794 | hwc->freq_count_stamp = now; | |
60db5e09 | 2795 | |
e050e3f0 SE |
2796 | /* |
2797 | * restart the event | |
2798 | * reload only if value has changed | |
f39d47ff SE |
2799 | * we have stopped the event so tell that |
2800 | * to perf_adjust_period() to avoid stopping it | |
2801 | * twice. | |
e050e3f0 | 2802 | */ |
abd50713 | 2803 | if (delta > 0) |
f39d47ff | 2804 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
2805 | |
2806 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
2807 | next: |
2808 | perf_pmu_enable(event->pmu); | |
60db5e09 | 2809 | } |
e050e3f0 | 2810 | |
f39d47ff | 2811 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 2812 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
2813 | } |
2814 | ||
235c7fc7 | 2815 | /* |
cdd6c482 | 2816 | * Round-robin a context's events: |
235c7fc7 | 2817 | */ |
cdd6c482 | 2818 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 2819 | { |
dddd3379 TG |
2820 | /* |
2821 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
2822 | * disabled by the inheritance code. | |
2823 | */ | |
2824 | if (!ctx->rotate_disable) | |
2825 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
2826 | } |
2827 | ||
b5ab4cd5 | 2828 | /* |
e9d2b064 PZ |
2829 | * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized |
2830 | * because they're strictly cpu affine and rotate_start is called with IRQs | |
2831 | * disabled, while rotate_context is called from IRQ context. | |
b5ab4cd5 | 2832 | */ |
9e630205 | 2833 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 2834 | { |
8dc85d54 | 2835 | struct perf_event_context *ctx = NULL; |
e050e3f0 | 2836 | int rotate = 0, remove = 1; |
7fc23a53 | 2837 | |
b5ab4cd5 | 2838 | if (cpuctx->ctx.nr_events) { |
e9d2b064 | 2839 | remove = 0; |
b5ab4cd5 PZ |
2840 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
2841 | rotate = 1; | |
2842 | } | |
235c7fc7 | 2843 | |
8dc85d54 | 2844 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 2845 | if (ctx && ctx->nr_events) { |
e9d2b064 | 2846 | remove = 0; |
b5ab4cd5 PZ |
2847 | if (ctx->nr_events != ctx->nr_active) |
2848 | rotate = 1; | |
2849 | } | |
9717e6cd | 2850 | |
e050e3f0 | 2851 | if (!rotate) |
0f5a2601 PZ |
2852 | goto done; |
2853 | ||
facc4307 | 2854 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 2855 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 2856 | |
e050e3f0 SE |
2857 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
2858 | if (ctx) | |
2859 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 2860 | |
e050e3f0 SE |
2861 | rotate_ctx(&cpuctx->ctx); |
2862 | if (ctx) | |
2863 | rotate_ctx(ctx); | |
235c7fc7 | 2864 | |
e050e3f0 | 2865 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 2866 | |
0f5a2601 PZ |
2867 | perf_pmu_enable(cpuctx->ctx.pmu); |
2868 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 2869 | done: |
e9d2b064 PZ |
2870 | if (remove) |
2871 | list_del_init(&cpuctx->rotation_list); | |
9e630205 SE |
2872 | |
2873 | return rotate; | |
e9d2b064 PZ |
2874 | } |
2875 | ||
026249ef FW |
2876 | #ifdef CONFIG_NO_HZ_FULL |
2877 | bool perf_event_can_stop_tick(void) | |
2878 | { | |
948b26b6 | 2879 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 2880 | __this_cpu_read(perf_throttled_count)) |
026249ef | 2881 | return false; |
d84153d6 FW |
2882 | else |
2883 | return true; | |
026249ef FW |
2884 | } |
2885 | #endif | |
2886 | ||
e9d2b064 PZ |
2887 | void perf_event_task_tick(void) |
2888 | { | |
2889 | struct list_head *head = &__get_cpu_var(rotation_list); | |
2890 | struct perf_cpu_context *cpuctx, *tmp; | |
e050e3f0 SE |
2891 | struct perf_event_context *ctx; |
2892 | int throttled; | |
b5ab4cd5 | 2893 | |
e9d2b064 PZ |
2894 | WARN_ON(!irqs_disabled()); |
2895 | ||
e050e3f0 SE |
2896 | __this_cpu_inc(perf_throttled_seq); |
2897 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
2898 | ||
e9d2b064 | 2899 | list_for_each_entry_safe(cpuctx, tmp, head, rotation_list) { |
e050e3f0 SE |
2900 | ctx = &cpuctx->ctx; |
2901 | perf_adjust_freq_unthr_context(ctx, throttled); | |
2902 | ||
2903 | ctx = cpuctx->task_ctx; | |
2904 | if (ctx) | |
2905 | perf_adjust_freq_unthr_context(ctx, throttled); | |
e9d2b064 | 2906 | } |
0793a61d TG |
2907 | } |
2908 | ||
889ff015 FW |
2909 | static int event_enable_on_exec(struct perf_event *event, |
2910 | struct perf_event_context *ctx) | |
2911 | { | |
2912 | if (!event->attr.enable_on_exec) | |
2913 | return 0; | |
2914 | ||
2915 | event->attr.enable_on_exec = 0; | |
2916 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
2917 | return 0; | |
2918 | ||
1d9b482e | 2919 | __perf_event_mark_enabled(event); |
889ff015 FW |
2920 | |
2921 | return 1; | |
2922 | } | |
2923 | ||
57e7986e | 2924 | /* |
cdd6c482 | 2925 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
2926 | * This expects task == current. |
2927 | */ | |
8dc85d54 | 2928 | static void perf_event_enable_on_exec(struct perf_event_context *ctx) |
57e7986e | 2929 | { |
cdd6c482 | 2930 | struct perf_event *event; |
57e7986e PM |
2931 | unsigned long flags; |
2932 | int enabled = 0; | |
889ff015 | 2933 | int ret; |
57e7986e PM |
2934 | |
2935 | local_irq_save(flags); | |
cdd6c482 | 2936 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
2937 | goto out; |
2938 | ||
e566b76e SE |
2939 | /* |
2940 | * We must ctxsw out cgroup events to avoid conflict | |
2941 | * when invoking perf_task_event_sched_in() later on | |
2942 | * in this function. Otherwise we end up trying to | |
2943 | * ctxswin cgroup events which are already scheduled | |
2944 | * in. | |
2945 | */ | |
a8d757ef | 2946 | perf_cgroup_sched_out(current, NULL); |
57e7986e | 2947 | |
e625cce1 | 2948 | raw_spin_lock(&ctx->lock); |
04dc2dbb | 2949 | task_ctx_sched_out(ctx); |
57e7986e | 2950 | |
b79387ef | 2951 | list_for_each_entry(event, &ctx->event_list, event_entry) { |
889ff015 FW |
2952 | ret = event_enable_on_exec(event, ctx); |
2953 | if (ret) | |
2954 | enabled = 1; | |
57e7986e PM |
2955 | } |
2956 | ||
2957 | /* | |
cdd6c482 | 2958 | * Unclone this context if we enabled any event. |
57e7986e | 2959 | */ |
71a851b4 PZ |
2960 | if (enabled) |
2961 | unclone_ctx(ctx); | |
57e7986e | 2962 | |
e625cce1 | 2963 | raw_spin_unlock(&ctx->lock); |
57e7986e | 2964 | |
e566b76e SE |
2965 | /* |
2966 | * Also calls ctxswin for cgroup events, if any: | |
2967 | */ | |
e5d1367f | 2968 | perf_event_context_sched_in(ctx, ctx->task); |
9ed6060d | 2969 | out: |
57e7986e PM |
2970 | local_irq_restore(flags); |
2971 | } | |
2972 | ||
0793a61d | 2973 | /* |
cdd6c482 | 2974 | * Cross CPU call to read the hardware event |
0793a61d | 2975 | */ |
cdd6c482 | 2976 | static void __perf_event_read(void *info) |
0793a61d | 2977 | { |
cdd6c482 IM |
2978 | struct perf_event *event = info; |
2979 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2980 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
621a01ea | 2981 | |
e1ac3614 PM |
2982 | /* |
2983 | * If this is a task context, we need to check whether it is | |
2984 | * the current task context of this cpu. If not it has been | |
2985 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
2986 | * event->count would have been updated to a recent sample |
2987 | * when the event was scheduled out. | |
e1ac3614 PM |
2988 | */ |
2989 | if (ctx->task && cpuctx->task_ctx != ctx) | |
2990 | return; | |
2991 | ||
e625cce1 | 2992 | raw_spin_lock(&ctx->lock); |
e5d1367f | 2993 | if (ctx->is_active) { |
542e72fc | 2994 | update_context_time(ctx); |
e5d1367f SE |
2995 | update_cgrp_time_from_event(event); |
2996 | } | |
cdd6c482 | 2997 | update_event_times(event); |
542e72fc PZ |
2998 | if (event->state == PERF_EVENT_STATE_ACTIVE) |
2999 | event->pmu->read(event); | |
e625cce1 | 3000 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3001 | } |
3002 | ||
b5e58793 PZ |
3003 | static inline u64 perf_event_count(struct perf_event *event) |
3004 | { | |
e7850595 | 3005 | return local64_read(&event->count) + atomic64_read(&event->child_count); |
b5e58793 PZ |
3006 | } |
3007 | ||
cdd6c482 | 3008 | static u64 perf_event_read(struct perf_event *event) |
0793a61d TG |
3009 | { |
3010 | /* | |
cdd6c482 IM |
3011 | * If event is enabled and currently active on a CPU, update the |
3012 | * value in the event structure: | |
0793a61d | 3013 | */ |
cdd6c482 IM |
3014 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
3015 | smp_call_function_single(event->oncpu, | |
3016 | __perf_event_read, event, 1); | |
3017 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
2b8988c9 PZ |
3018 | struct perf_event_context *ctx = event->ctx; |
3019 | unsigned long flags; | |
3020 | ||
e625cce1 | 3021 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3022 | /* |
3023 | * may read while context is not active | |
3024 | * (e.g., thread is blocked), in that case | |
3025 | * we cannot update context time | |
3026 | */ | |
e5d1367f | 3027 | if (ctx->is_active) { |
c530ccd9 | 3028 | update_context_time(ctx); |
e5d1367f SE |
3029 | update_cgrp_time_from_event(event); |
3030 | } | |
cdd6c482 | 3031 | update_event_times(event); |
e625cce1 | 3032 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d TG |
3033 | } |
3034 | ||
b5e58793 | 3035 | return perf_event_count(event); |
0793a61d TG |
3036 | } |
3037 | ||
a63eaf34 | 3038 | /* |
cdd6c482 | 3039 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3040 | */ |
eb184479 | 3041 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3042 | { |
e625cce1 | 3043 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3044 | mutex_init(&ctx->mutex); |
889ff015 FW |
3045 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3046 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3047 | INIT_LIST_HEAD(&ctx->event_list); |
3048 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3049 | } |
3050 | ||
3051 | static struct perf_event_context * | |
3052 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3053 | { | |
3054 | struct perf_event_context *ctx; | |
3055 | ||
3056 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3057 | if (!ctx) | |
3058 | return NULL; | |
3059 | ||
3060 | __perf_event_init_context(ctx); | |
3061 | if (task) { | |
3062 | ctx->task = task; | |
3063 | get_task_struct(task); | |
0793a61d | 3064 | } |
eb184479 PZ |
3065 | ctx->pmu = pmu; |
3066 | ||
3067 | return ctx; | |
a63eaf34 PM |
3068 | } |
3069 | ||
2ebd4ffb MH |
3070 | static struct task_struct * |
3071 | find_lively_task_by_vpid(pid_t vpid) | |
3072 | { | |
3073 | struct task_struct *task; | |
3074 | int err; | |
0793a61d TG |
3075 | |
3076 | rcu_read_lock(); | |
2ebd4ffb | 3077 | if (!vpid) |
0793a61d TG |
3078 | task = current; |
3079 | else | |
2ebd4ffb | 3080 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3081 | if (task) |
3082 | get_task_struct(task); | |
3083 | rcu_read_unlock(); | |
3084 | ||
3085 | if (!task) | |
3086 | return ERR_PTR(-ESRCH); | |
3087 | ||
0793a61d | 3088 | /* Reuse ptrace permission checks for now. */ |
c93f7669 PM |
3089 | err = -EACCES; |
3090 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3091 | goto errout; | |
3092 | ||
2ebd4ffb MH |
3093 | return task; |
3094 | errout: | |
3095 | put_task_struct(task); | |
3096 | return ERR_PTR(err); | |
3097 | ||
3098 | } | |
3099 | ||
fe4b04fa PZ |
3100 | /* |
3101 | * Returns a matching context with refcount and pincount. | |
3102 | */ | |
108b02cf | 3103 | static struct perf_event_context * |
38a81da2 | 3104 | find_get_context(struct pmu *pmu, struct task_struct *task, int cpu) |
0793a61d | 3105 | { |
cdd6c482 | 3106 | struct perf_event_context *ctx; |
22a4f650 | 3107 | struct perf_cpu_context *cpuctx; |
25346b93 | 3108 | unsigned long flags; |
8dc85d54 | 3109 | int ctxn, err; |
0793a61d | 3110 | |
22a4ec72 | 3111 | if (!task) { |
cdd6c482 | 3112 | /* Must be root to operate on a CPU event: */ |
0764771d | 3113 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3114 | return ERR_PTR(-EACCES); |
3115 | ||
0793a61d | 3116 | /* |
cdd6c482 | 3117 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3118 | * offline CPU and activate it when the CPU comes up, but |
3119 | * that's for later. | |
3120 | */ | |
f6325e30 | 3121 | if (!cpu_online(cpu)) |
0793a61d TG |
3122 | return ERR_PTR(-ENODEV); |
3123 | ||
108b02cf | 3124 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3125 | ctx = &cpuctx->ctx; |
c93f7669 | 3126 | get_ctx(ctx); |
fe4b04fa | 3127 | ++ctx->pin_count; |
0793a61d | 3128 | |
0793a61d TG |
3129 | return ctx; |
3130 | } | |
3131 | ||
8dc85d54 PZ |
3132 | err = -EINVAL; |
3133 | ctxn = pmu->task_ctx_nr; | |
3134 | if (ctxn < 0) | |
3135 | goto errout; | |
3136 | ||
9ed6060d | 3137 | retry: |
8dc85d54 | 3138 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3139 | if (ctx) { |
71a851b4 | 3140 | unclone_ctx(ctx); |
fe4b04fa | 3141 | ++ctx->pin_count; |
e625cce1 | 3142 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
9137fb28 | 3143 | } else { |
eb184479 | 3144 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3145 | err = -ENOMEM; |
3146 | if (!ctx) | |
3147 | goto errout; | |
eb184479 | 3148 | |
dbe08d82 ON |
3149 | err = 0; |
3150 | mutex_lock(&task->perf_event_mutex); | |
3151 | /* | |
3152 | * If it has already passed perf_event_exit_task(). | |
3153 | * we must see PF_EXITING, it takes this mutex too. | |
3154 | */ | |
3155 | if (task->flags & PF_EXITING) | |
3156 | err = -ESRCH; | |
3157 | else if (task->perf_event_ctxp[ctxn]) | |
3158 | err = -EAGAIN; | |
fe4b04fa | 3159 | else { |
9137fb28 | 3160 | get_ctx(ctx); |
fe4b04fa | 3161 | ++ctx->pin_count; |
dbe08d82 | 3162 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3163 | } |
dbe08d82 ON |
3164 | mutex_unlock(&task->perf_event_mutex); |
3165 | ||
3166 | if (unlikely(err)) { | |
9137fb28 | 3167 | put_ctx(ctx); |
dbe08d82 ON |
3168 | |
3169 | if (err == -EAGAIN) | |
3170 | goto retry; | |
3171 | goto errout; | |
a63eaf34 PM |
3172 | } |
3173 | } | |
3174 | ||
0793a61d | 3175 | return ctx; |
c93f7669 | 3176 | |
9ed6060d | 3177 | errout: |
c93f7669 | 3178 | return ERR_PTR(err); |
0793a61d TG |
3179 | } |
3180 | ||
6fb2915d LZ |
3181 | static void perf_event_free_filter(struct perf_event *event); |
3182 | ||
cdd6c482 | 3183 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3184 | { |
cdd6c482 | 3185 | struct perf_event *event; |
592903cd | 3186 | |
cdd6c482 IM |
3187 | event = container_of(head, struct perf_event, rcu_head); |
3188 | if (event->ns) | |
3189 | put_pid_ns(event->ns); | |
6fb2915d | 3190 | perf_event_free_filter(event); |
cdd6c482 | 3191 | kfree(event); |
592903cd PZ |
3192 | } |
3193 | ||
76369139 | 3194 | static void ring_buffer_put(struct ring_buffer *rb); |
9bb5d40c | 3195 | static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb); |
925d519a | 3196 | |
4beb31f3 | 3197 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3198 | { |
4beb31f3 FW |
3199 | if (event->parent) |
3200 | return; | |
3201 | ||
3202 | if (has_branch_stack(event)) { | |
3203 | if (!(event->attach_state & PERF_ATTACH_TASK)) | |
3204 | atomic_dec(&per_cpu(perf_branch_stack_events, cpu)); | |
3205 | } | |
3206 | if (is_cgroup_event(event)) | |
3207 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3208 | } | |
925d519a | 3209 | |
4beb31f3 FW |
3210 | static void unaccount_event(struct perf_event *event) |
3211 | { | |
3212 | if (event->parent) | |
3213 | return; | |
3214 | ||
3215 | if (event->attach_state & PERF_ATTACH_TASK) | |
3216 | static_key_slow_dec_deferred(&perf_sched_events); | |
3217 | if (event->attr.mmap || event->attr.mmap_data) | |
3218 | atomic_dec(&nr_mmap_events); | |
3219 | if (event->attr.comm) | |
3220 | atomic_dec(&nr_comm_events); | |
3221 | if (event->attr.task) | |
3222 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3223 | if (event->attr.freq) |
3224 | atomic_dec(&nr_freq_events); | |
4beb31f3 FW |
3225 | if (is_cgroup_event(event)) |
3226 | static_key_slow_dec_deferred(&perf_sched_events); | |
3227 | if (has_branch_stack(event)) | |
3228 | static_key_slow_dec_deferred(&perf_sched_events); | |
3229 | ||
3230 | unaccount_event_cpu(event, event->cpu); | |
3231 | } | |
925d519a | 3232 | |
766d6c07 FW |
3233 | static void __free_event(struct perf_event *event) |
3234 | { | |
cdd6c482 | 3235 | if (!event->parent) { |
927c7a9e FW |
3236 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3237 | put_callchain_buffers(); | |
f344011c | 3238 | } |
9ee318a7 | 3239 | |
766d6c07 FW |
3240 | if (event->destroy) |
3241 | event->destroy(event); | |
3242 | ||
3243 | if (event->ctx) | |
3244 | put_ctx(event->ctx); | |
3245 | ||
3246 | call_rcu(&event->rcu_head, free_event_rcu); | |
3247 | } | |
cdd6c482 | 3248 | static void free_event(struct perf_event *event) |
f1600952 | 3249 | { |
e360adbe | 3250 | irq_work_sync(&event->pending); |
925d519a | 3251 | |
4beb31f3 | 3252 | unaccount_event(event); |
9ee318a7 | 3253 | |
76369139 | 3254 | if (event->rb) { |
9bb5d40c PZ |
3255 | struct ring_buffer *rb; |
3256 | ||
3257 | /* | |
3258 | * Can happen when we close an event with re-directed output. | |
3259 | * | |
3260 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3261 | * over us; possibly making our ring_buffer_put() the last. | |
3262 | */ | |
3263 | mutex_lock(&event->mmap_mutex); | |
3264 | rb = event->rb; | |
3265 | if (rb) { | |
3266 | rcu_assign_pointer(event->rb, NULL); | |
3267 | ring_buffer_detach(event, rb); | |
3268 | ring_buffer_put(rb); /* could be last */ | |
3269 | } | |
3270 | mutex_unlock(&event->mmap_mutex); | |
a4be7c27 PZ |
3271 | } |
3272 | ||
e5d1367f SE |
3273 | if (is_cgroup_event(event)) |
3274 | perf_detach_cgroup(event); | |
3275 | ||
0c67b408 | 3276 | |
766d6c07 | 3277 | __free_event(event); |
f1600952 PZ |
3278 | } |
3279 | ||
a66a3052 | 3280 | int perf_event_release_kernel(struct perf_event *event) |
0793a61d | 3281 | { |
cdd6c482 | 3282 | struct perf_event_context *ctx = event->ctx; |
0793a61d | 3283 | |
ad3a37de | 3284 | WARN_ON_ONCE(ctx->parent_ctx); |
a0507c84 PZ |
3285 | /* |
3286 | * There are two ways this annotation is useful: | |
3287 | * | |
3288 | * 1) there is a lock recursion from perf_event_exit_task | |
3289 | * see the comment there. | |
3290 | * | |
3291 | * 2) there is a lock-inversion with mmap_sem through | |
3292 | * perf_event_read_group(), which takes faults while | |
3293 | * holding ctx->mutex, however this is called after | |
3294 | * the last filedesc died, so there is no possibility | |
3295 | * to trigger the AB-BA case. | |
3296 | */ | |
3297 | mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); | |
46ce0fe9 | 3298 | perf_remove_from_context(event, true); |
d859e29f | 3299 | mutex_unlock(&ctx->mutex); |
0793a61d | 3300 | |
cdd6c482 | 3301 | free_event(event); |
0793a61d TG |
3302 | |
3303 | return 0; | |
3304 | } | |
a66a3052 | 3305 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); |
0793a61d | 3306 | |
a66a3052 PZ |
3307 | /* |
3308 | * Called when the last reference to the file is gone. | |
3309 | */ | |
a6fa941d | 3310 | static void put_event(struct perf_event *event) |
fb0459d7 | 3311 | { |
8882135b | 3312 | struct task_struct *owner; |
fb0459d7 | 3313 | |
a6fa941d AV |
3314 | if (!atomic_long_dec_and_test(&event->refcount)) |
3315 | return; | |
fb0459d7 | 3316 | |
8882135b PZ |
3317 | rcu_read_lock(); |
3318 | owner = ACCESS_ONCE(event->owner); | |
3319 | /* | |
3320 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3321 | * !owner it means the list deletion is complete and we can indeed | |
3322 | * free this event, otherwise we need to serialize on | |
3323 | * owner->perf_event_mutex. | |
3324 | */ | |
3325 | smp_read_barrier_depends(); | |
3326 | if (owner) { | |
3327 | /* | |
3328 | * Since delayed_put_task_struct() also drops the last | |
3329 | * task reference we can safely take a new reference | |
3330 | * while holding the rcu_read_lock(). | |
3331 | */ | |
3332 | get_task_struct(owner); | |
3333 | } | |
3334 | rcu_read_unlock(); | |
3335 | ||
3336 | if (owner) { | |
3337 | mutex_lock(&owner->perf_event_mutex); | |
3338 | /* | |
3339 | * We have to re-check the event->owner field, if it is cleared | |
3340 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3341 | * ensured they're done, and we can proceed with freeing the | |
3342 | * event. | |
3343 | */ | |
3344 | if (event->owner) | |
3345 | list_del_init(&event->owner_entry); | |
3346 | mutex_unlock(&owner->perf_event_mutex); | |
3347 | put_task_struct(owner); | |
3348 | } | |
3349 | ||
a6fa941d AV |
3350 | perf_event_release_kernel(event); |
3351 | } | |
3352 | ||
3353 | static int perf_release(struct inode *inode, struct file *file) | |
3354 | { | |
3355 | put_event(file->private_data); | |
3356 | return 0; | |
fb0459d7 | 3357 | } |
fb0459d7 | 3358 | |
59ed446f | 3359 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3360 | { |
cdd6c482 | 3361 | struct perf_event *child; |
e53c0994 PZ |
3362 | u64 total = 0; |
3363 | ||
59ed446f PZ |
3364 | *enabled = 0; |
3365 | *running = 0; | |
3366 | ||
6f10581a | 3367 | mutex_lock(&event->child_mutex); |
cdd6c482 | 3368 | total += perf_event_read(event); |
59ed446f PZ |
3369 | *enabled += event->total_time_enabled + |
3370 | atomic64_read(&event->child_total_time_enabled); | |
3371 | *running += event->total_time_running + | |
3372 | atomic64_read(&event->child_total_time_running); | |
3373 | ||
3374 | list_for_each_entry(child, &event->child_list, child_list) { | |
cdd6c482 | 3375 | total += perf_event_read(child); |
59ed446f PZ |
3376 | *enabled += child->total_time_enabled; |
3377 | *running += child->total_time_running; | |
3378 | } | |
6f10581a | 3379 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3380 | |
3381 | return total; | |
3382 | } | |
fb0459d7 | 3383 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3384 | |
cdd6c482 | 3385 | static int perf_event_read_group(struct perf_event *event, |
3dab77fb PZ |
3386 | u64 read_format, char __user *buf) |
3387 | { | |
cdd6c482 | 3388 | struct perf_event *leader = event->group_leader, *sub; |
6f10581a PZ |
3389 | int n = 0, size = 0, ret = -EFAULT; |
3390 | struct perf_event_context *ctx = leader->ctx; | |
abf4868b | 3391 | u64 values[5]; |
59ed446f | 3392 | u64 count, enabled, running; |
abf4868b | 3393 | |
6f10581a | 3394 | mutex_lock(&ctx->mutex); |
59ed446f | 3395 | count = perf_event_read_value(leader, &enabled, &running); |
3dab77fb PZ |
3396 | |
3397 | values[n++] = 1 + leader->nr_siblings; | |
59ed446f PZ |
3398 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
3399 | values[n++] = enabled; | |
3400 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3401 | values[n++] = running; | |
abf4868b PZ |
3402 | values[n++] = count; |
3403 | if (read_format & PERF_FORMAT_ID) | |
3404 | values[n++] = primary_event_id(leader); | |
3dab77fb PZ |
3405 | |
3406 | size = n * sizeof(u64); | |
3407 | ||
3408 | if (copy_to_user(buf, values, size)) | |
6f10581a | 3409 | goto unlock; |
3dab77fb | 3410 | |
6f10581a | 3411 | ret = size; |
3dab77fb | 3412 | |
65abc865 | 3413 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
abf4868b | 3414 | n = 0; |
3dab77fb | 3415 | |
59ed446f | 3416 | values[n++] = perf_event_read_value(sub, &enabled, &running); |
abf4868b PZ |
3417 | if (read_format & PERF_FORMAT_ID) |
3418 | values[n++] = primary_event_id(sub); | |
3419 | ||
3420 | size = n * sizeof(u64); | |
3421 | ||
184d3da8 | 3422 | if (copy_to_user(buf + ret, values, size)) { |
6f10581a PZ |
3423 | ret = -EFAULT; |
3424 | goto unlock; | |
3425 | } | |
abf4868b PZ |
3426 | |
3427 | ret += size; | |
3dab77fb | 3428 | } |
6f10581a PZ |
3429 | unlock: |
3430 | mutex_unlock(&ctx->mutex); | |
3dab77fb | 3431 | |
abf4868b | 3432 | return ret; |
3dab77fb PZ |
3433 | } |
3434 | ||
cdd6c482 | 3435 | static int perf_event_read_one(struct perf_event *event, |
3dab77fb PZ |
3436 | u64 read_format, char __user *buf) |
3437 | { | |
59ed446f | 3438 | u64 enabled, running; |
3dab77fb PZ |
3439 | u64 values[4]; |
3440 | int n = 0; | |
3441 | ||
59ed446f PZ |
3442 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3443 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3444 | values[n++] = enabled; | |
3445 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3446 | values[n++] = running; | |
3dab77fb | 3447 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3448 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3449 | |
3450 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3451 | return -EFAULT; | |
3452 | ||
3453 | return n * sizeof(u64); | |
3454 | } | |
3455 | ||
0793a61d | 3456 | /* |
cdd6c482 | 3457 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3458 | */ |
3459 | static ssize_t | |
cdd6c482 | 3460 | perf_read_hw(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3461 | { |
cdd6c482 | 3462 | u64 read_format = event->attr.read_format; |
3dab77fb | 3463 | int ret; |
0793a61d | 3464 | |
3b6f9e5c | 3465 | /* |
cdd6c482 | 3466 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
3467 | * error state (i.e. because it was pinned but it couldn't be |
3468 | * scheduled on to the CPU at some point). | |
3469 | */ | |
cdd6c482 | 3470 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
3471 | return 0; |
3472 | ||
c320c7b7 | 3473 | if (count < event->read_size) |
3dab77fb PZ |
3474 | return -ENOSPC; |
3475 | ||
cdd6c482 | 3476 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 3477 | if (read_format & PERF_FORMAT_GROUP) |
cdd6c482 | 3478 | ret = perf_event_read_group(event, read_format, buf); |
3dab77fb | 3479 | else |
cdd6c482 | 3480 | ret = perf_event_read_one(event, read_format, buf); |
0793a61d | 3481 | |
3dab77fb | 3482 | return ret; |
0793a61d TG |
3483 | } |
3484 | ||
0793a61d TG |
3485 | static ssize_t |
3486 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
3487 | { | |
cdd6c482 | 3488 | struct perf_event *event = file->private_data; |
0793a61d | 3489 | |
cdd6c482 | 3490 | return perf_read_hw(event, buf, count); |
0793a61d TG |
3491 | } |
3492 | ||
3493 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
3494 | { | |
cdd6c482 | 3495 | struct perf_event *event = file->private_data; |
76369139 | 3496 | struct ring_buffer *rb; |
c33a0bc4 | 3497 | unsigned int events = POLL_HUP; |
c7138f37 | 3498 | |
10c6db11 | 3499 | /* |
9bb5d40c PZ |
3500 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
3501 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
3502 | */ |
3503 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
3504 | rb = event->rb; |
3505 | if (rb) | |
76369139 | 3506 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 PZ |
3507 | mutex_unlock(&event->mmap_mutex); |
3508 | ||
cdd6c482 | 3509 | poll_wait(file, &event->waitq, wait); |
0793a61d | 3510 | |
0793a61d TG |
3511 | return events; |
3512 | } | |
3513 | ||
cdd6c482 | 3514 | static void perf_event_reset(struct perf_event *event) |
6de6a7b9 | 3515 | { |
cdd6c482 | 3516 | (void)perf_event_read(event); |
e7850595 | 3517 | local64_set(&event->count, 0); |
cdd6c482 | 3518 | perf_event_update_userpage(event); |
3df5edad PZ |
3519 | } |
3520 | ||
c93f7669 | 3521 | /* |
cdd6c482 IM |
3522 | * Holding the top-level event's child_mutex means that any |
3523 | * descendant process that has inherited this event will block | |
3524 | * in sync_child_event if it goes to exit, thus satisfying the | |
3525 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 3526 | */ |
cdd6c482 IM |
3527 | static void perf_event_for_each_child(struct perf_event *event, |
3528 | void (*func)(struct perf_event *)) | |
3df5edad | 3529 | { |
cdd6c482 | 3530 | struct perf_event *child; |
3df5edad | 3531 | |
cdd6c482 IM |
3532 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3533 | mutex_lock(&event->child_mutex); | |
3534 | func(event); | |
3535 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 3536 | func(child); |
cdd6c482 | 3537 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
3538 | } |
3539 | ||
cdd6c482 IM |
3540 | static void perf_event_for_each(struct perf_event *event, |
3541 | void (*func)(struct perf_event *)) | |
3df5edad | 3542 | { |
cdd6c482 IM |
3543 | struct perf_event_context *ctx = event->ctx; |
3544 | struct perf_event *sibling; | |
3df5edad | 3545 | |
75f937f2 PZ |
3546 | WARN_ON_ONCE(ctx->parent_ctx); |
3547 | mutex_lock(&ctx->mutex); | |
cdd6c482 | 3548 | event = event->group_leader; |
75f937f2 | 3549 | |
cdd6c482 | 3550 | perf_event_for_each_child(event, func); |
cdd6c482 | 3551 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 3552 | perf_event_for_each_child(sibling, func); |
75f937f2 | 3553 | mutex_unlock(&ctx->mutex); |
6de6a7b9 PZ |
3554 | } |
3555 | ||
cdd6c482 | 3556 | static int perf_event_period(struct perf_event *event, u64 __user *arg) |
08247e31 | 3557 | { |
cdd6c482 | 3558 | struct perf_event_context *ctx = event->ctx; |
bad7192b | 3559 | int ret = 0, active; |
08247e31 PZ |
3560 | u64 value; |
3561 | ||
6c7e550f | 3562 | if (!is_sampling_event(event)) |
08247e31 PZ |
3563 | return -EINVAL; |
3564 | ||
ad0cf347 | 3565 | if (copy_from_user(&value, arg, sizeof(value))) |
08247e31 PZ |
3566 | return -EFAULT; |
3567 | ||
3568 | if (!value) | |
3569 | return -EINVAL; | |
3570 | ||
e625cce1 | 3571 | raw_spin_lock_irq(&ctx->lock); |
cdd6c482 IM |
3572 | if (event->attr.freq) { |
3573 | if (value > sysctl_perf_event_sample_rate) { | |
08247e31 PZ |
3574 | ret = -EINVAL; |
3575 | goto unlock; | |
3576 | } | |
3577 | ||
cdd6c482 | 3578 | event->attr.sample_freq = value; |
08247e31 | 3579 | } else { |
cdd6c482 IM |
3580 | event->attr.sample_period = value; |
3581 | event->hw.sample_period = value; | |
08247e31 | 3582 | } |
bad7192b PZ |
3583 | |
3584 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
3585 | if (active) { | |
3586 | perf_pmu_disable(ctx->pmu); | |
3587 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3588 | } | |
3589 | ||
3590 | local64_set(&event->hw.period_left, 0); | |
3591 | ||
3592 | if (active) { | |
3593 | event->pmu->start(event, PERF_EF_RELOAD); | |
3594 | perf_pmu_enable(ctx->pmu); | |
3595 | } | |
3596 | ||
08247e31 | 3597 | unlock: |
e625cce1 | 3598 | raw_spin_unlock_irq(&ctx->lock); |
08247e31 PZ |
3599 | |
3600 | return ret; | |
3601 | } | |
3602 | ||
ac9721f3 PZ |
3603 | static const struct file_operations perf_fops; |
3604 | ||
2903ff01 | 3605 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 3606 | { |
2903ff01 AV |
3607 | struct fd f = fdget(fd); |
3608 | if (!f.file) | |
3609 | return -EBADF; | |
ac9721f3 | 3610 | |
2903ff01 AV |
3611 | if (f.file->f_op != &perf_fops) { |
3612 | fdput(f); | |
3613 | return -EBADF; | |
ac9721f3 | 3614 | } |
2903ff01 AV |
3615 | *p = f; |
3616 | return 0; | |
ac9721f3 PZ |
3617 | } |
3618 | ||
3619 | static int perf_event_set_output(struct perf_event *event, | |
3620 | struct perf_event *output_event); | |
6fb2915d | 3621 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
a4be7c27 | 3622 | |
d859e29f PM |
3623 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
3624 | { | |
cdd6c482 IM |
3625 | struct perf_event *event = file->private_data; |
3626 | void (*func)(struct perf_event *); | |
3df5edad | 3627 | u32 flags = arg; |
d859e29f PM |
3628 | |
3629 | switch (cmd) { | |
cdd6c482 IM |
3630 | case PERF_EVENT_IOC_ENABLE: |
3631 | func = perf_event_enable; | |
d859e29f | 3632 | break; |
cdd6c482 IM |
3633 | case PERF_EVENT_IOC_DISABLE: |
3634 | func = perf_event_disable; | |
79f14641 | 3635 | break; |
cdd6c482 IM |
3636 | case PERF_EVENT_IOC_RESET: |
3637 | func = perf_event_reset; | |
6de6a7b9 | 3638 | break; |
3df5edad | 3639 | |
cdd6c482 IM |
3640 | case PERF_EVENT_IOC_REFRESH: |
3641 | return perf_event_refresh(event, arg); | |
08247e31 | 3642 | |
cdd6c482 IM |
3643 | case PERF_EVENT_IOC_PERIOD: |
3644 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 3645 | |
cf4957f1 JO |
3646 | case PERF_EVENT_IOC_ID: |
3647 | { | |
3648 | u64 id = primary_event_id(event); | |
3649 | ||
3650 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
3651 | return -EFAULT; | |
3652 | return 0; | |
3653 | } | |
3654 | ||
cdd6c482 | 3655 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 3656 | { |
ac9721f3 | 3657 | int ret; |
ac9721f3 | 3658 | if (arg != -1) { |
2903ff01 AV |
3659 | struct perf_event *output_event; |
3660 | struct fd output; | |
3661 | ret = perf_fget_light(arg, &output); | |
3662 | if (ret) | |
3663 | return ret; | |
3664 | output_event = output.file->private_data; | |
3665 | ret = perf_event_set_output(event, output_event); | |
3666 | fdput(output); | |
3667 | } else { | |
3668 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 3669 | } |
ac9721f3 PZ |
3670 | return ret; |
3671 | } | |
a4be7c27 | 3672 | |
6fb2915d LZ |
3673 | case PERF_EVENT_IOC_SET_FILTER: |
3674 | return perf_event_set_filter(event, (void __user *)arg); | |
3675 | ||
d859e29f | 3676 | default: |
3df5edad | 3677 | return -ENOTTY; |
d859e29f | 3678 | } |
3df5edad PZ |
3679 | |
3680 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 3681 | perf_event_for_each(event, func); |
3df5edad | 3682 | else |
cdd6c482 | 3683 | perf_event_for_each_child(event, func); |
3df5edad PZ |
3684 | |
3685 | return 0; | |
d859e29f PM |
3686 | } |
3687 | ||
cdd6c482 | 3688 | int perf_event_task_enable(void) |
771d7cde | 3689 | { |
cdd6c482 | 3690 | struct perf_event *event; |
771d7cde | 3691 | |
cdd6c482 IM |
3692 | mutex_lock(¤t->perf_event_mutex); |
3693 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) | |
3694 | perf_event_for_each_child(event, perf_event_enable); | |
3695 | mutex_unlock(¤t->perf_event_mutex); | |
771d7cde PZ |
3696 | |
3697 | return 0; | |
3698 | } | |
3699 | ||
cdd6c482 | 3700 | int perf_event_task_disable(void) |
771d7cde | 3701 | { |
cdd6c482 | 3702 | struct perf_event *event; |
771d7cde | 3703 | |
cdd6c482 IM |
3704 | mutex_lock(¤t->perf_event_mutex); |
3705 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) | |
3706 | perf_event_for_each_child(event, perf_event_disable); | |
3707 | mutex_unlock(¤t->perf_event_mutex); | |
771d7cde PZ |
3708 | |
3709 | return 0; | |
3710 | } | |
3711 | ||
cdd6c482 | 3712 | static int perf_event_index(struct perf_event *event) |
194002b2 | 3713 | { |
a4eaf7f1 PZ |
3714 | if (event->hw.state & PERF_HES_STOPPED) |
3715 | return 0; | |
3716 | ||
cdd6c482 | 3717 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
3718 | return 0; |
3719 | ||
35edc2a5 | 3720 | return event->pmu->event_idx(event); |
194002b2 PZ |
3721 | } |
3722 | ||
c4794295 | 3723 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 3724 | u64 *now, |
7f310a5d EM |
3725 | u64 *enabled, |
3726 | u64 *running) | |
c4794295 | 3727 | { |
e3f3541c | 3728 | u64 ctx_time; |
c4794295 | 3729 | |
e3f3541c PZ |
3730 | *now = perf_clock(); |
3731 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
3732 | *enabled = ctx_time - event->tstamp_enabled; |
3733 | *running = ctx_time - event->tstamp_running; | |
3734 | } | |
3735 | ||
fa731587 PZ |
3736 | static void perf_event_init_userpage(struct perf_event *event) |
3737 | { | |
3738 | struct perf_event_mmap_page *userpg; | |
3739 | struct ring_buffer *rb; | |
3740 | ||
3741 | rcu_read_lock(); | |
3742 | rb = rcu_dereference(event->rb); | |
3743 | if (!rb) | |
3744 | goto unlock; | |
3745 | ||
3746 | userpg = rb->user_page; | |
3747 | ||
3748 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
3749 | userpg->cap_bit0_is_deprecated = 1; | |
3750 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
3751 | ||
3752 | unlock: | |
3753 | rcu_read_unlock(); | |
3754 | } | |
3755 | ||
c7206205 | 3756 | void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now) |
e3f3541c PZ |
3757 | { |
3758 | } | |
3759 | ||
38ff667b PZ |
3760 | /* |
3761 | * Callers need to ensure there can be no nesting of this function, otherwise | |
3762 | * the seqlock logic goes bad. We can not serialize this because the arch | |
3763 | * code calls this from NMI context. | |
3764 | */ | |
cdd6c482 | 3765 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 3766 | { |
cdd6c482 | 3767 | struct perf_event_mmap_page *userpg; |
76369139 | 3768 | struct ring_buffer *rb; |
e3f3541c | 3769 | u64 enabled, running, now; |
38ff667b PZ |
3770 | |
3771 | rcu_read_lock(); | |
5ec4c599 PZ |
3772 | rb = rcu_dereference(event->rb); |
3773 | if (!rb) | |
3774 | goto unlock; | |
3775 | ||
0d641208 EM |
3776 | /* |
3777 | * compute total_time_enabled, total_time_running | |
3778 | * based on snapshot values taken when the event | |
3779 | * was last scheduled in. | |
3780 | * | |
3781 | * we cannot simply called update_context_time() | |
3782 | * because of locking issue as we can be called in | |
3783 | * NMI context | |
3784 | */ | |
e3f3541c | 3785 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 3786 | |
76369139 | 3787 | userpg = rb->user_page; |
7b732a75 PZ |
3788 | /* |
3789 | * Disable preemption so as to not let the corresponding user-space | |
3790 | * spin too long if we get preempted. | |
3791 | */ | |
3792 | preempt_disable(); | |
37d81828 | 3793 | ++userpg->lock; |
92f22a38 | 3794 | barrier(); |
cdd6c482 | 3795 | userpg->index = perf_event_index(event); |
b5e58793 | 3796 | userpg->offset = perf_event_count(event); |
365a4038 | 3797 | if (userpg->index) |
e7850595 | 3798 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 3799 | |
0d641208 | 3800 | userpg->time_enabled = enabled + |
cdd6c482 | 3801 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 3802 | |
0d641208 | 3803 | userpg->time_running = running + |
cdd6c482 | 3804 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 3805 | |
c7206205 | 3806 | arch_perf_update_userpage(userpg, now); |
e3f3541c | 3807 | |
92f22a38 | 3808 | barrier(); |
37d81828 | 3809 | ++userpg->lock; |
7b732a75 | 3810 | preempt_enable(); |
38ff667b | 3811 | unlock: |
7b732a75 | 3812 | rcu_read_unlock(); |
37d81828 PM |
3813 | } |
3814 | ||
906010b2 PZ |
3815 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
3816 | { | |
3817 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 3818 | struct ring_buffer *rb; |
906010b2 PZ |
3819 | int ret = VM_FAULT_SIGBUS; |
3820 | ||
3821 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
3822 | if (vmf->pgoff == 0) | |
3823 | ret = 0; | |
3824 | return ret; | |
3825 | } | |
3826 | ||
3827 | rcu_read_lock(); | |
76369139 FW |
3828 | rb = rcu_dereference(event->rb); |
3829 | if (!rb) | |
906010b2 PZ |
3830 | goto unlock; |
3831 | ||
3832 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
3833 | goto unlock; | |
3834 | ||
76369139 | 3835 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
3836 | if (!vmf->page) |
3837 | goto unlock; | |
3838 | ||
3839 | get_page(vmf->page); | |
3840 | vmf->page->mapping = vma->vm_file->f_mapping; | |
3841 | vmf->page->index = vmf->pgoff; | |
3842 | ||
3843 | ret = 0; | |
3844 | unlock: | |
3845 | rcu_read_unlock(); | |
3846 | ||
3847 | return ret; | |
3848 | } | |
3849 | ||
10c6db11 PZ |
3850 | static void ring_buffer_attach(struct perf_event *event, |
3851 | struct ring_buffer *rb) | |
3852 | { | |
3853 | unsigned long flags; | |
3854 | ||
3855 | if (!list_empty(&event->rb_entry)) | |
3856 | return; | |
3857 | ||
3858 | spin_lock_irqsave(&rb->event_lock, flags); | |
9bb5d40c PZ |
3859 | if (list_empty(&event->rb_entry)) |
3860 | list_add(&event->rb_entry, &rb->event_list); | |
10c6db11 PZ |
3861 | spin_unlock_irqrestore(&rb->event_lock, flags); |
3862 | } | |
3863 | ||
9bb5d40c | 3864 | static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb) |
10c6db11 PZ |
3865 | { |
3866 | unsigned long flags; | |
3867 | ||
3868 | if (list_empty(&event->rb_entry)) | |
3869 | return; | |
3870 | ||
3871 | spin_lock_irqsave(&rb->event_lock, flags); | |
3872 | list_del_init(&event->rb_entry); | |
3873 | wake_up_all(&event->waitq); | |
3874 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
3875 | } | |
3876 | ||
3877 | static void ring_buffer_wakeup(struct perf_event *event) | |
3878 | { | |
3879 | struct ring_buffer *rb; | |
3880 | ||
3881 | rcu_read_lock(); | |
3882 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
3883 | if (rb) { |
3884 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
3885 | wake_up_all(&event->waitq); | |
3886 | } | |
10c6db11 PZ |
3887 | rcu_read_unlock(); |
3888 | } | |
3889 | ||
76369139 | 3890 | static void rb_free_rcu(struct rcu_head *rcu_head) |
906010b2 | 3891 | { |
76369139 | 3892 | struct ring_buffer *rb; |
906010b2 | 3893 | |
76369139 FW |
3894 | rb = container_of(rcu_head, struct ring_buffer, rcu_head); |
3895 | rb_free(rb); | |
7b732a75 PZ |
3896 | } |
3897 | ||
76369139 | 3898 | static struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 3899 | { |
76369139 | 3900 | struct ring_buffer *rb; |
7b732a75 | 3901 | |
ac9721f3 | 3902 | rcu_read_lock(); |
76369139 FW |
3903 | rb = rcu_dereference(event->rb); |
3904 | if (rb) { | |
3905 | if (!atomic_inc_not_zero(&rb->refcount)) | |
3906 | rb = NULL; | |
ac9721f3 PZ |
3907 | } |
3908 | rcu_read_unlock(); | |
3909 | ||
76369139 | 3910 | return rb; |
ac9721f3 PZ |
3911 | } |
3912 | ||
76369139 | 3913 | static void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 3914 | { |
76369139 | 3915 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 3916 | return; |
7b732a75 | 3917 | |
9bb5d40c | 3918 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 3919 | |
76369139 | 3920 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
3921 | } |
3922 | ||
3923 | static void perf_mmap_open(struct vm_area_struct *vma) | |
3924 | { | |
cdd6c482 | 3925 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 3926 | |
cdd6c482 | 3927 | atomic_inc(&event->mmap_count); |
9bb5d40c | 3928 | atomic_inc(&event->rb->mmap_count); |
7b732a75 PZ |
3929 | } |
3930 | ||
9bb5d40c PZ |
3931 | /* |
3932 | * A buffer can be mmap()ed multiple times; either directly through the same | |
3933 | * event, or through other events by use of perf_event_set_output(). | |
3934 | * | |
3935 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
3936 | * the buffer here, where we still have a VM context. This means we need | |
3937 | * to detach all events redirecting to us. | |
3938 | */ | |
7b732a75 PZ |
3939 | static void perf_mmap_close(struct vm_area_struct *vma) |
3940 | { | |
cdd6c482 | 3941 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 3942 | |
9bb5d40c PZ |
3943 | struct ring_buffer *rb = event->rb; |
3944 | struct user_struct *mmap_user = rb->mmap_user; | |
3945 | int mmap_locked = rb->mmap_locked; | |
3946 | unsigned long size = perf_data_size(rb); | |
789f90fc | 3947 | |
9bb5d40c PZ |
3948 | atomic_dec(&rb->mmap_count); |
3949 | ||
3950 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
3951 | return; | |
3952 | ||
3953 | /* Detach current event from the buffer. */ | |
3954 | rcu_assign_pointer(event->rb, NULL); | |
3955 | ring_buffer_detach(event, rb); | |
3956 | mutex_unlock(&event->mmap_mutex); | |
3957 | ||
3958 | /* If there's still other mmap()s of this buffer, we're done. */ | |
3959 | if (atomic_read(&rb->mmap_count)) { | |
3960 | ring_buffer_put(rb); /* can't be last */ | |
3961 | return; | |
3962 | } | |
ac9721f3 | 3963 | |
9bb5d40c PZ |
3964 | /* |
3965 | * No other mmap()s, detach from all other events that might redirect | |
3966 | * into the now unreachable buffer. Somewhat complicated by the | |
3967 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
3968 | */ | |
3969 | again: | |
3970 | rcu_read_lock(); | |
3971 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
3972 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
3973 | /* | |
3974 | * This event is en-route to free_event() which will | |
3975 | * detach it and remove it from the list. | |
3976 | */ | |
3977 | continue; | |
3978 | } | |
3979 | rcu_read_unlock(); | |
789f90fc | 3980 | |
9bb5d40c PZ |
3981 | mutex_lock(&event->mmap_mutex); |
3982 | /* | |
3983 | * Check we didn't race with perf_event_set_output() which can | |
3984 | * swizzle the rb from under us while we were waiting to | |
3985 | * acquire mmap_mutex. | |
3986 | * | |
3987 | * If we find a different rb; ignore this event, a next | |
3988 | * iteration will no longer find it on the list. We have to | |
3989 | * still restart the iteration to make sure we're not now | |
3990 | * iterating the wrong list. | |
3991 | */ | |
3992 | if (event->rb == rb) { | |
3993 | rcu_assign_pointer(event->rb, NULL); | |
3994 | ring_buffer_detach(event, rb); | |
3995 | ring_buffer_put(rb); /* can't be last, we still have one */ | |
26cb63ad | 3996 | } |
cdd6c482 | 3997 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 3998 | put_event(event); |
ac9721f3 | 3999 | |
9bb5d40c PZ |
4000 | /* |
4001 | * Restart the iteration; either we're on the wrong list or | |
4002 | * destroyed its integrity by doing a deletion. | |
4003 | */ | |
4004 | goto again; | |
7b732a75 | 4005 | } |
9bb5d40c PZ |
4006 | rcu_read_unlock(); |
4007 | ||
4008 | /* | |
4009 | * It could be there's still a few 0-ref events on the list; they'll | |
4010 | * get cleaned up by free_event() -- they'll also still have their | |
4011 | * ref on the rb and will free it whenever they are done with it. | |
4012 | * | |
4013 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4014 | * undo the VM accounting. | |
4015 | */ | |
4016 | ||
4017 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4018 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4019 | free_uid(mmap_user); | |
4020 | ||
4021 | ring_buffer_put(rb); /* could be last */ | |
37d81828 PM |
4022 | } |
4023 | ||
f0f37e2f | 4024 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 PZ |
4025 | .open = perf_mmap_open, |
4026 | .close = perf_mmap_close, | |
4027 | .fault = perf_mmap_fault, | |
4028 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4029 | }; |
4030 | ||
4031 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4032 | { | |
cdd6c482 | 4033 | struct perf_event *event = file->private_data; |
22a4f650 | 4034 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4035 | struct user_struct *user = current_user(); |
22a4f650 | 4036 | unsigned long locked, lock_limit; |
76369139 | 4037 | struct ring_buffer *rb; |
7b732a75 PZ |
4038 | unsigned long vma_size; |
4039 | unsigned long nr_pages; | |
789f90fc | 4040 | long user_extra, extra; |
d57e34fd | 4041 | int ret = 0, flags = 0; |
37d81828 | 4042 | |
c7920614 PZ |
4043 | /* |
4044 | * Don't allow mmap() of inherited per-task counters. This would | |
4045 | * create a performance issue due to all children writing to the | |
76369139 | 4046 | * same rb. |
c7920614 PZ |
4047 | */ |
4048 | if (event->cpu == -1 && event->attr.inherit) | |
4049 | return -EINVAL; | |
4050 | ||
43a21ea8 | 4051 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4052 | return -EINVAL; |
7b732a75 PZ |
4053 | |
4054 | vma_size = vma->vm_end - vma->vm_start; | |
4055 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4056 | ||
7730d865 | 4057 | /* |
76369139 | 4058 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4059 | * can do bitmasks instead of modulo. |
4060 | */ | |
4061 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) | |
37d81828 PM |
4062 | return -EINVAL; |
4063 | ||
7b732a75 | 4064 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4065 | return -EINVAL; |
4066 | ||
7b732a75 PZ |
4067 | if (vma->vm_pgoff != 0) |
4068 | return -EINVAL; | |
37d81828 | 4069 | |
cdd6c482 | 4070 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4071 | again: |
cdd6c482 | 4072 | mutex_lock(&event->mmap_mutex); |
76369139 | 4073 | if (event->rb) { |
9bb5d40c | 4074 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4075 | ret = -EINVAL; |
9bb5d40c PZ |
4076 | goto unlock; |
4077 | } | |
4078 | ||
4079 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4080 | /* | |
4081 | * Raced against perf_mmap_close() through | |
4082 | * perf_event_set_output(). Try again, hope for better | |
4083 | * luck. | |
4084 | */ | |
4085 | mutex_unlock(&event->mmap_mutex); | |
4086 | goto again; | |
4087 | } | |
4088 | ||
ebb3c4c4 PZ |
4089 | goto unlock; |
4090 | } | |
4091 | ||
789f90fc | 4092 | user_extra = nr_pages + 1; |
cdd6c482 | 4093 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4094 | |
4095 | /* | |
4096 | * Increase the limit linearly with more CPUs: | |
4097 | */ | |
4098 | user_lock_limit *= num_online_cpus(); | |
4099 | ||
789f90fc | 4100 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4101 | |
789f90fc PZ |
4102 | extra = 0; |
4103 | if (user_locked > user_lock_limit) | |
4104 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4105 | |
78d7d407 | 4106 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4107 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4108 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4109 | |
459ec28a IM |
4110 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4111 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4112 | ret = -EPERM; |
4113 | goto unlock; | |
4114 | } | |
7b732a75 | 4115 | |
76369139 | 4116 | WARN_ON(event->rb); |
906010b2 | 4117 | |
d57e34fd | 4118 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4119 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4120 | |
4ec8363d VW |
4121 | rb = rb_alloc(nr_pages, |
4122 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4123 | event->cpu, flags); | |
4124 | ||
76369139 | 4125 | if (!rb) { |
ac9721f3 | 4126 | ret = -ENOMEM; |
ebb3c4c4 | 4127 | goto unlock; |
ac9721f3 | 4128 | } |
26cb63ad | 4129 | |
9bb5d40c | 4130 | atomic_set(&rb->mmap_count, 1); |
26cb63ad PZ |
4131 | rb->mmap_locked = extra; |
4132 | rb->mmap_user = get_current_user(); | |
43a21ea8 | 4133 | |
ac9721f3 | 4134 | atomic_long_add(user_extra, &user->locked_vm); |
26cb63ad PZ |
4135 | vma->vm_mm->pinned_vm += extra; |
4136 | ||
9bb5d40c | 4137 | ring_buffer_attach(event, rb); |
26cb63ad | 4138 | rcu_assign_pointer(event->rb, rb); |
ac9721f3 | 4139 | |
fa731587 | 4140 | perf_event_init_userpage(event); |
9a0f05cb PZ |
4141 | perf_event_update_userpage(event); |
4142 | ||
ebb3c4c4 | 4143 | unlock: |
ac9721f3 PZ |
4144 | if (!ret) |
4145 | atomic_inc(&event->mmap_count); | |
cdd6c482 | 4146 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4147 | |
9bb5d40c PZ |
4148 | /* |
4149 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4150 | * vma. | |
4151 | */ | |
26cb63ad | 4152 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4153 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 PZ |
4154 | |
4155 | return ret; | |
37d81828 PM |
4156 | } |
4157 | ||
3c446b3d PZ |
4158 | static int perf_fasync(int fd, struct file *filp, int on) |
4159 | { | |
496ad9aa | 4160 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4161 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4162 | int retval; |
4163 | ||
4164 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4165 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4166 | mutex_unlock(&inode->i_mutex); |
4167 | ||
4168 | if (retval < 0) | |
4169 | return retval; | |
4170 | ||
4171 | return 0; | |
4172 | } | |
4173 | ||
0793a61d | 4174 | static const struct file_operations perf_fops = { |
3326c1ce | 4175 | .llseek = no_llseek, |
0793a61d TG |
4176 | .release = perf_release, |
4177 | .read = perf_read, | |
4178 | .poll = perf_poll, | |
d859e29f PM |
4179 | .unlocked_ioctl = perf_ioctl, |
4180 | .compat_ioctl = perf_ioctl, | |
37d81828 | 4181 | .mmap = perf_mmap, |
3c446b3d | 4182 | .fasync = perf_fasync, |
0793a61d TG |
4183 | }; |
4184 | ||
925d519a | 4185 | /* |
cdd6c482 | 4186 | * Perf event wakeup |
925d519a PZ |
4187 | * |
4188 | * If there's data, ensure we set the poll() state and publish everything | |
4189 | * to user-space before waking everybody up. | |
4190 | */ | |
4191 | ||
cdd6c482 | 4192 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4193 | { |
10c6db11 | 4194 | ring_buffer_wakeup(event); |
4c9e2542 | 4195 | |
cdd6c482 IM |
4196 | if (event->pending_kill) { |
4197 | kill_fasync(&event->fasync, SIGIO, event->pending_kill); | |
4198 | event->pending_kill = 0; | |
4c9e2542 | 4199 | } |
925d519a PZ |
4200 | } |
4201 | ||
e360adbe | 4202 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4203 | { |
cdd6c482 IM |
4204 | struct perf_event *event = container_of(entry, |
4205 | struct perf_event, pending); | |
79f14641 | 4206 | |
cdd6c482 IM |
4207 | if (event->pending_disable) { |
4208 | event->pending_disable = 0; | |
4209 | __perf_event_disable(event); | |
79f14641 PZ |
4210 | } |
4211 | ||
cdd6c482 IM |
4212 | if (event->pending_wakeup) { |
4213 | event->pending_wakeup = 0; | |
4214 | perf_event_wakeup(event); | |
79f14641 PZ |
4215 | } |
4216 | } | |
4217 | ||
39447b38 ZY |
4218 | /* |
4219 | * We assume there is only KVM supporting the callbacks. | |
4220 | * Later on, we might change it to a list if there is | |
4221 | * another virtualization implementation supporting the callbacks. | |
4222 | */ | |
4223 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4224 | ||
4225 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4226 | { | |
4227 | perf_guest_cbs = cbs; | |
4228 | return 0; | |
4229 | } | |
4230 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4231 | ||
4232 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4233 | { | |
4234 | perf_guest_cbs = NULL; | |
4235 | return 0; | |
4236 | } | |
4237 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4238 | ||
4018994f JO |
4239 | static void |
4240 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4241 | struct pt_regs *regs, u64 mask) | |
4242 | { | |
4243 | int bit; | |
4244 | ||
4245 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4246 | sizeof(mask) * BITS_PER_BYTE) { | |
4247 | u64 val; | |
4248 | ||
4249 | val = perf_reg_value(regs, bit); | |
4250 | perf_output_put(handle, val); | |
4251 | } | |
4252 | } | |
4253 | ||
4254 | static void perf_sample_regs_user(struct perf_regs_user *regs_user, | |
4255 | struct pt_regs *regs) | |
4256 | { | |
4257 | if (!user_mode(regs)) { | |
4258 | if (current->mm) | |
4259 | regs = task_pt_regs(current); | |
4260 | else | |
4261 | regs = NULL; | |
4262 | } | |
4263 | ||
4264 | if (regs) { | |
4265 | regs_user->regs = regs; | |
4266 | regs_user->abi = perf_reg_abi(current); | |
4267 | } | |
4268 | } | |
4269 | ||
c5ebcedb JO |
4270 | /* |
4271 | * Get remaining task size from user stack pointer. | |
4272 | * | |
4273 | * It'd be better to take stack vma map and limit this more | |
4274 | * precisly, but there's no way to get it safely under interrupt, | |
4275 | * so using TASK_SIZE as limit. | |
4276 | */ | |
4277 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
4278 | { | |
4279 | unsigned long addr = perf_user_stack_pointer(regs); | |
4280 | ||
4281 | if (!addr || addr >= TASK_SIZE) | |
4282 | return 0; | |
4283 | ||
4284 | return TASK_SIZE - addr; | |
4285 | } | |
4286 | ||
4287 | static u16 | |
4288 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
4289 | struct pt_regs *regs) | |
4290 | { | |
4291 | u64 task_size; | |
4292 | ||
4293 | /* No regs, no stack pointer, no dump. */ | |
4294 | if (!regs) | |
4295 | return 0; | |
4296 | ||
4297 | /* | |
4298 | * Check if we fit in with the requested stack size into the: | |
4299 | * - TASK_SIZE | |
4300 | * If we don't, we limit the size to the TASK_SIZE. | |
4301 | * | |
4302 | * - remaining sample size | |
4303 | * If we don't, we customize the stack size to | |
4304 | * fit in to the remaining sample size. | |
4305 | */ | |
4306 | ||
4307 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
4308 | stack_size = min(stack_size, (u16) task_size); | |
4309 | ||
4310 | /* Current header size plus static size and dynamic size. */ | |
4311 | header_size += 2 * sizeof(u64); | |
4312 | ||
4313 | /* Do we fit in with the current stack dump size? */ | |
4314 | if ((u16) (header_size + stack_size) < header_size) { | |
4315 | /* | |
4316 | * If we overflow the maximum size for the sample, | |
4317 | * we customize the stack dump size to fit in. | |
4318 | */ | |
4319 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
4320 | stack_size = round_up(stack_size, sizeof(u64)); | |
4321 | } | |
4322 | ||
4323 | return stack_size; | |
4324 | } | |
4325 | ||
4326 | static void | |
4327 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
4328 | struct pt_regs *regs) | |
4329 | { | |
4330 | /* Case of a kernel thread, nothing to dump */ | |
4331 | if (!regs) { | |
4332 | u64 size = 0; | |
4333 | perf_output_put(handle, size); | |
4334 | } else { | |
4335 | unsigned long sp; | |
4336 | unsigned int rem; | |
4337 | u64 dyn_size; | |
4338 | ||
4339 | /* | |
4340 | * We dump: | |
4341 | * static size | |
4342 | * - the size requested by user or the best one we can fit | |
4343 | * in to the sample max size | |
4344 | * data | |
4345 | * - user stack dump data | |
4346 | * dynamic size | |
4347 | * - the actual dumped size | |
4348 | */ | |
4349 | ||
4350 | /* Static size. */ | |
4351 | perf_output_put(handle, dump_size); | |
4352 | ||
4353 | /* Data. */ | |
4354 | sp = perf_user_stack_pointer(regs); | |
4355 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
4356 | dyn_size = dump_size - rem; | |
4357 | ||
4358 | perf_output_skip(handle, rem); | |
4359 | ||
4360 | /* Dynamic size. */ | |
4361 | perf_output_put(handle, dyn_size); | |
4362 | } | |
4363 | } | |
4364 | ||
c980d109 ACM |
4365 | static void __perf_event_header__init_id(struct perf_event_header *header, |
4366 | struct perf_sample_data *data, | |
4367 | struct perf_event *event) | |
6844c09d ACM |
4368 | { |
4369 | u64 sample_type = event->attr.sample_type; | |
4370 | ||
4371 | data->type = sample_type; | |
4372 | header->size += event->id_header_size; | |
4373 | ||
4374 | if (sample_type & PERF_SAMPLE_TID) { | |
4375 | /* namespace issues */ | |
4376 | data->tid_entry.pid = perf_event_pid(event, current); | |
4377 | data->tid_entry.tid = perf_event_tid(event, current); | |
4378 | } | |
4379 | ||
4380 | if (sample_type & PERF_SAMPLE_TIME) | |
4381 | data->time = perf_clock(); | |
4382 | ||
ff3d527c | 4383 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
4384 | data->id = primary_event_id(event); |
4385 | ||
4386 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4387 | data->stream_id = event->id; | |
4388 | ||
4389 | if (sample_type & PERF_SAMPLE_CPU) { | |
4390 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
4391 | data->cpu_entry.reserved = 0; | |
4392 | } | |
4393 | } | |
4394 | ||
76369139 FW |
4395 | void perf_event_header__init_id(struct perf_event_header *header, |
4396 | struct perf_sample_data *data, | |
4397 | struct perf_event *event) | |
c980d109 ACM |
4398 | { |
4399 | if (event->attr.sample_id_all) | |
4400 | __perf_event_header__init_id(header, data, event); | |
4401 | } | |
4402 | ||
4403 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
4404 | struct perf_sample_data *data) | |
4405 | { | |
4406 | u64 sample_type = data->type; | |
4407 | ||
4408 | if (sample_type & PERF_SAMPLE_TID) | |
4409 | perf_output_put(handle, data->tid_entry); | |
4410 | ||
4411 | if (sample_type & PERF_SAMPLE_TIME) | |
4412 | perf_output_put(handle, data->time); | |
4413 | ||
4414 | if (sample_type & PERF_SAMPLE_ID) | |
4415 | perf_output_put(handle, data->id); | |
4416 | ||
4417 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4418 | perf_output_put(handle, data->stream_id); | |
4419 | ||
4420 | if (sample_type & PERF_SAMPLE_CPU) | |
4421 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
4422 | |
4423 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
4424 | perf_output_put(handle, data->id); | |
c980d109 ACM |
4425 | } |
4426 | ||
76369139 FW |
4427 | void perf_event__output_id_sample(struct perf_event *event, |
4428 | struct perf_output_handle *handle, | |
4429 | struct perf_sample_data *sample) | |
c980d109 ACM |
4430 | { |
4431 | if (event->attr.sample_id_all) | |
4432 | __perf_event__output_id_sample(handle, sample); | |
4433 | } | |
4434 | ||
3dab77fb | 4435 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
4436 | struct perf_event *event, |
4437 | u64 enabled, u64 running) | |
3dab77fb | 4438 | { |
cdd6c482 | 4439 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
4440 | u64 values[4]; |
4441 | int n = 0; | |
4442 | ||
b5e58793 | 4443 | values[n++] = perf_event_count(event); |
3dab77fb | 4444 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 4445 | values[n++] = enabled + |
cdd6c482 | 4446 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
4447 | } |
4448 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 4449 | values[n++] = running + |
cdd6c482 | 4450 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
4451 | } |
4452 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 4453 | values[n++] = primary_event_id(event); |
3dab77fb | 4454 | |
76369139 | 4455 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
4456 | } |
4457 | ||
4458 | /* | |
cdd6c482 | 4459 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
4460 | */ |
4461 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
4462 | struct perf_event *event, |
4463 | u64 enabled, u64 running) | |
3dab77fb | 4464 | { |
cdd6c482 IM |
4465 | struct perf_event *leader = event->group_leader, *sub; |
4466 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
4467 | u64 values[5]; |
4468 | int n = 0; | |
4469 | ||
4470 | values[n++] = 1 + leader->nr_siblings; | |
4471 | ||
4472 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 4473 | values[n++] = enabled; |
3dab77fb PZ |
4474 | |
4475 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 4476 | values[n++] = running; |
3dab77fb | 4477 | |
cdd6c482 | 4478 | if (leader != event) |
3dab77fb PZ |
4479 | leader->pmu->read(leader); |
4480 | ||
b5e58793 | 4481 | values[n++] = perf_event_count(leader); |
3dab77fb | 4482 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4483 | values[n++] = primary_event_id(leader); |
3dab77fb | 4484 | |
76369139 | 4485 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 4486 | |
65abc865 | 4487 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
4488 | n = 0; |
4489 | ||
6f5ab001 JO |
4490 | if ((sub != event) && |
4491 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
4492 | sub->pmu->read(sub); |
4493 | ||
b5e58793 | 4494 | values[n++] = perf_event_count(sub); |
3dab77fb | 4495 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4496 | values[n++] = primary_event_id(sub); |
3dab77fb | 4497 | |
76369139 | 4498 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
4499 | } |
4500 | } | |
4501 | ||
eed01528 SE |
4502 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
4503 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4504 | ||
3dab77fb | 4505 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 4506 | struct perf_event *event) |
3dab77fb | 4507 | { |
e3f3541c | 4508 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
4509 | u64 read_format = event->attr.read_format; |
4510 | ||
4511 | /* | |
4512 | * compute total_time_enabled, total_time_running | |
4513 | * based on snapshot values taken when the event | |
4514 | * was last scheduled in. | |
4515 | * | |
4516 | * we cannot simply called update_context_time() | |
4517 | * because of locking issue as we are called in | |
4518 | * NMI context | |
4519 | */ | |
c4794295 | 4520 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 4521 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 4522 | |
cdd6c482 | 4523 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 4524 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 4525 | else |
eed01528 | 4526 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
4527 | } |
4528 | ||
5622f295 MM |
4529 | void perf_output_sample(struct perf_output_handle *handle, |
4530 | struct perf_event_header *header, | |
4531 | struct perf_sample_data *data, | |
cdd6c482 | 4532 | struct perf_event *event) |
5622f295 MM |
4533 | { |
4534 | u64 sample_type = data->type; | |
4535 | ||
4536 | perf_output_put(handle, *header); | |
4537 | ||
ff3d527c AH |
4538 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
4539 | perf_output_put(handle, data->id); | |
4540 | ||
5622f295 MM |
4541 | if (sample_type & PERF_SAMPLE_IP) |
4542 | perf_output_put(handle, data->ip); | |
4543 | ||
4544 | if (sample_type & PERF_SAMPLE_TID) | |
4545 | perf_output_put(handle, data->tid_entry); | |
4546 | ||
4547 | if (sample_type & PERF_SAMPLE_TIME) | |
4548 | perf_output_put(handle, data->time); | |
4549 | ||
4550 | if (sample_type & PERF_SAMPLE_ADDR) | |
4551 | perf_output_put(handle, data->addr); | |
4552 | ||
4553 | if (sample_type & PERF_SAMPLE_ID) | |
4554 | perf_output_put(handle, data->id); | |
4555 | ||
4556 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
4557 | perf_output_put(handle, data->stream_id); | |
4558 | ||
4559 | if (sample_type & PERF_SAMPLE_CPU) | |
4560 | perf_output_put(handle, data->cpu_entry); | |
4561 | ||
4562 | if (sample_type & PERF_SAMPLE_PERIOD) | |
4563 | perf_output_put(handle, data->period); | |
4564 | ||
4565 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 4566 | perf_output_read(handle, event); |
5622f295 MM |
4567 | |
4568 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
4569 | if (data->callchain) { | |
4570 | int size = 1; | |
4571 | ||
4572 | if (data->callchain) | |
4573 | size += data->callchain->nr; | |
4574 | ||
4575 | size *= sizeof(u64); | |
4576 | ||
76369139 | 4577 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
4578 | } else { |
4579 | u64 nr = 0; | |
4580 | perf_output_put(handle, nr); | |
4581 | } | |
4582 | } | |
4583 | ||
4584 | if (sample_type & PERF_SAMPLE_RAW) { | |
4585 | if (data->raw) { | |
4586 | perf_output_put(handle, data->raw->size); | |
76369139 FW |
4587 | __output_copy(handle, data->raw->data, |
4588 | data->raw->size); | |
5622f295 MM |
4589 | } else { |
4590 | struct { | |
4591 | u32 size; | |
4592 | u32 data; | |
4593 | } raw = { | |
4594 | .size = sizeof(u32), | |
4595 | .data = 0, | |
4596 | }; | |
4597 | perf_output_put(handle, raw); | |
4598 | } | |
4599 | } | |
a7ac67ea | 4600 | |
bce38cd5 SE |
4601 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
4602 | if (data->br_stack) { | |
4603 | size_t size; | |
4604 | ||
4605 | size = data->br_stack->nr | |
4606 | * sizeof(struct perf_branch_entry); | |
4607 | ||
4608 | perf_output_put(handle, data->br_stack->nr); | |
4609 | perf_output_copy(handle, data->br_stack->entries, size); | |
4610 | } else { | |
4611 | /* | |
4612 | * we always store at least the value of nr | |
4613 | */ | |
4614 | u64 nr = 0; | |
4615 | perf_output_put(handle, nr); | |
4616 | } | |
4617 | } | |
4018994f JO |
4618 | |
4619 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
4620 | u64 abi = data->regs_user.abi; | |
4621 | ||
4622 | /* | |
4623 | * If there are no regs to dump, notice it through | |
4624 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
4625 | */ | |
4626 | perf_output_put(handle, abi); | |
4627 | ||
4628 | if (abi) { | |
4629 | u64 mask = event->attr.sample_regs_user; | |
4630 | perf_output_sample_regs(handle, | |
4631 | data->regs_user.regs, | |
4632 | mask); | |
4633 | } | |
4634 | } | |
c5ebcedb | 4635 | |
a5cdd40c | 4636 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
4637 | perf_output_sample_ustack(handle, |
4638 | data->stack_user_size, | |
4639 | data->regs_user.regs); | |
a5cdd40c | 4640 | } |
c3feedf2 AK |
4641 | |
4642 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
4643 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
4644 | |
4645 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
4646 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 4647 | |
fdfbbd07 AK |
4648 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
4649 | perf_output_put(handle, data->txn); | |
4650 | ||
a5cdd40c PZ |
4651 | if (!event->attr.watermark) { |
4652 | int wakeup_events = event->attr.wakeup_events; | |
4653 | ||
4654 | if (wakeup_events) { | |
4655 | struct ring_buffer *rb = handle->rb; | |
4656 | int events = local_inc_return(&rb->events); | |
4657 | ||
4658 | if (events >= wakeup_events) { | |
4659 | local_sub(wakeup_events, &rb->events); | |
4660 | local_inc(&rb->wakeup); | |
4661 | } | |
4662 | } | |
4663 | } | |
5622f295 MM |
4664 | } |
4665 | ||
4666 | void perf_prepare_sample(struct perf_event_header *header, | |
4667 | struct perf_sample_data *data, | |
cdd6c482 | 4668 | struct perf_event *event, |
5622f295 | 4669 | struct pt_regs *regs) |
7b732a75 | 4670 | { |
cdd6c482 | 4671 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 4672 | |
cdd6c482 | 4673 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 4674 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
4675 | |
4676 | header->misc = 0; | |
4677 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 4678 | |
c980d109 | 4679 | __perf_event_header__init_id(header, data, event); |
6844c09d | 4680 | |
c320c7b7 | 4681 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
4682 | data->ip = perf_instruction_pointer(regs); |
4683 | ||
b23f3325 | 4684 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 4685 | int size = 1; |
394ee076 | 4686 | |
e6dab5ff | 4687 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
4688 | |
4689 | if (data->callchain) | |
4690 | size += data->callchain->nr; | |
4691 | ||
4692 | header->size += size * sizeof(u64); | |
394ee076 PZ |
4693 | } |
4694 | ||
3a43ce68 | 4695 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
4696 | int size = sizeof(u32); |
4697 | ||
4698 | if (data->raw) | |
4699 | size += data->raw->size; | |
4700 | else | |
4701 | size += sizeof(u32); | |
4702 | ||
4703 | WARN_ON_ONCE(size & (sizeof(u64)-1)); | |
5622f295 | 4704 | header->size += size; |
7f453c24 | 4705 | } |
bce38cd5 SE |
4706 | |
4707 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
4708 | int size = sizeof(u64); /* nr */ | |
4709 | if (data->br_stack) { | |
4710 | size += data->br_stack->nr | |
4711 | * sizeof(struct perf_branch_entry); | |
4712 | } | |
4713 | header->size += size; | |
4714 | } | |
4018994f JO |
4715 | |
4716 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
4717 | /* regs dump ABI info */ | |
4718 | int size = sizeof(u64); | |
4719 | ||
4720 | perf_sample_regs_user(&data->regs_user, regs); | |
4721 | ||
4722 | if (data->regs_user.regs) { | |
4723 | u64 mask = event->attr.sample_regs_user; | |
4724 | size += hweight64(mask) * sizeof(u64); | |
4725 | } | |
4726 | ||
4727 | header->size += size; | |
4728 | } | |
c5ebcedb JO |
4729 | |
4730 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
4731 | /* | |
4732 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
4733 | * processed as the last one or have additional check added | |
4734 | * in case new sample type is added, because we could eat | |
4735 | * up the rest of the sample size. | |
4736 | */ | |
4737 | struct perf_regs_user *uregs = &data->regs_user; | |
4738 | u16 stack_size = event->attr.sample_stack_user; | |
4739 | u16 size = sizeof(u64); | |
4740 | ||
4741 | if (!uregs->abi) | |
4742 | perf_sample_regs_user(uregs, regs); | |
4743 | ||
4744 | stack_size = perf_sample_ustack_size(stack_size, header->size, | |
4745 | uregs->regs); | |
4746 | ||
4747 | /* | |
4748 | * If there is something to dump, add space for the dump | |
4749 | * itself and for the field that tells the dynamic size, | |
4750 | * which is how many have been actually dumped. | |
4751 | */ | |
4752 | if (stack_size) | |
4753 | size += sizeof(u64) + stack_size; | |
4754 | ||
4755 | data->stack_user_size = stack_size; | |
4756 | header->size += size; | |
4757 | } | |
5622f295 | 4758 | } |
7f453c24 | 4759 | |
a8b0ca17 | 4760 | static void perf_event_output(struct perf_event *event, |
5622f295 MM |
4761 | struct perf_sample_data *data, |
4762 | struct pt_regs *regs) | |
4763 | { | |
4764 | struct perf_output_handle handle; | |
4765 | struct perf_event_header header; | |
689802b2 | 4766 | |
927c7a9e FW |
4767 | /* protect the callchain buffers */ |
4768 | rcu_read_lock(); | |
4769 | ||
cdd6c482 | 4770 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 4771 | |
a7ac67ea | 4772 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 4773 | goto exit; |
0322cd6e | 4774 | |
cdd6c482 | 4775 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 4776 | |
8a057d84 | 4777 | perf_output_end(&handle); |
927c7a9e FW |
4778 | |
4779 | exit: | |
4780 | rcu_read_unlock(); | |
0322cd6e PZ |
4781 | } |
4782 | ||
38b200d6 | 4783 | /* |
cdd6c482 | 4784 | * read event_id |
38b200d6 PZ |
4785 | */ |
4786 | ||
4787 | struct perf_read_event { | |
4788 | struct perf_event_header header; | |
4789 | ||
4790 | u32 pid; | |
4791 | u32 tid; | |
38b200d6 PZ |
4792 | }; |
4793 | ||
4794 | static void | |
cdd6c482 | 4795 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
4796 | struct task_struct *task) |
4797 | { | |
4798 | struct perf_output_handle handle; | |
c980d109 | 4799 | struct perf_sample_data sample; |
dfc65094 | 4800 | struct perf_read_event read_event = { |
38b200d6 | 4801 | .header = { |
cdd6c482 | 4802 | .type = PERF_RECORD_READ, |
38b200d6 | 4803 | .misc = 0, |
c320c7b7 | 4804 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 4805 | }, |
cdd6c482 IM |
4806 | .pid = perf_event_pid(event, task), |
4807 | .tid = perf_event_tid(event, task), | |
38b200d6 | 4808 | }; |
3dab77fb | 4809 | int ret; |
38b200d6 | 4810 | |
c980d109 | 4811 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 4812 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
4813 | if (ret) |
4814 | return; | |
4815 | ||
dfc65094 | 4816 | perf_output_put(&handle, read_event); |
cdd6c482 | 4817 | perf_output_read(&handle, event); |
c980d109 | 4818 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 4819 | |
38b200d6 PZ |
4820 | perf_output_end(&handle); |
4821 | } | |
4822 | ||
52d857a8 JO |
4823 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
4824 | ||
4825 | static void | |
4826 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
4827 | perf_event_aux_output_cb output, |
4828 | void *data) | |
4829 | { | |
4830 | struct perf_event *event; | |
4831 | ||
4832 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
4833 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
4834 | continue; | |
4835 | if (!event_filter_match(event)) | |
4836 | continue; | |
67516844 | 4837 | output(event, data); |
52d857a8 JO |
4838 | } |
4839 | } | |
4840 | ||
4841 | static void | |
67516844 | 4842 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
4843 | struct perf_event_context *task_ctx) |
4844 | { | |
4845 | struct perf_cpu_context *cpuctx; | |
4846 | struct perf_event_context *ctx; | |
4847 | struct pmu *pmu; | |
4848 | int ctxn; | |
4849 | ||
4850 | rcu_read_lock(); | |
4851 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
4852 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
4853 | if (cpuctx->unique_pmu != pmu) | |
4854 | goto next; | |
67516844 | 4855 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
4856 | if (task_ctx) |
4857 | goto next; | |
4858 | ctxn = pmu->task_ctx_nr; | |
4859 | if (ctxn < 0) | |
4860 | goto next; | |
4861 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
4862 | if (ctx) | |
67516844 | 4863 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
4864 | next: |
4865 | put_cpu_ptr(pmu->pmu_cpu_context); | |
4866 | } | |
4867 | ||
4868 | if (task_ctx) { | |
4869 | preempt_disable(); | |
67516844 | 4870 | perf_event_aux_ctx(task_ctx, output, data); |
52d857a8 JO |
4871 | preempt_enable(); |
4872 | } | |
4873 | rcu_read_unlock(); | |
4874 | } | |
4875 | ||
60313ebe | 4876 | /* |
9f498cc5 PZ |
4877 | * task tracking -- fork/exit |
4878 | * | |
13d7a241 | 4879 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
4880 | */ |
4881 | ||
9f498cc5 | 4882 | struct perf_task_event { |
3a80b4a3 | 4883 | struct task_struct *task; |
cdd6c482 | 4884 | struct perf_event_context *task_ctx; |
60313ebe PZ |
4885 | |
4886 | struct { | |
4887 | struct perf_event_header header; | |
4888 | ||
4889 | u32 pid; | |
4890 | u32 ppid; | |
9f498cc5 PZ |
4891 | u32 tid; |
4892 | u32 ptid; | |
393b2ad8 | 4893 | u64 time; |
cdd6c482 | 4894 | } event_id; |
60313ebe PZ |
4895 | }; |
4896 | ||
67516844 JO |
4897 | static int perf_event_task_match(struct perf_event *event) |
4898 | { | |
13d7a241 SE |
4899 | return event->attr.comm || event->attr.mmap || |
4900 | event->attr.mmap2 || event->attr.mmap_data || | |
4901 | event->attr.task; | |
67516844 JO |
4902 | } |
4903 | ||
cdd6c482 | 4904 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 4905 | void *data) |
60313ebe | 4906 | { |
52d857a8 | 4907 | struct perf_task_event *task_event = data; |
60313ebe | 4908 | struct perf_output_handle handle; |
c980d109 | 4909 | struct perf_sample_data sample; |
9f498cc5 | 4910 | struct task_struct *task = task_event->task; |
c980d109 | 4911 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 4912 | |
67516844 JO |
4913 | if (!perf_event_task_match(event)) |
4914 | return; | |
4915 | ||
c980d109 | 4916 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 4917 | |
c980d109 | 4918 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 4919 | task_event->event_id.header.size); |
ef60777c | 4920 | if (ret) |
c980d109 | 4921 | goto out; |
60313ebe | 4922 | |
cdd6c482 IM |
4923 | task_event->event_id.pid = perf_event_pid(event, task); |
4924 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 4925 | |
cdd6c482 IM |
4926 | task_event->event_id.tid = perf_event_tid(event, task); |
4927 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 4928 | |
cdd6c482 | 4929 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 4930 | |
c980d109 ACM |
4931 | perf_event__output_id_sample(event, &handle, &sample); |
4932 | ||
60313ebe | 4933 | perf_output_end(&handle); |
c980d109 ACM |
4934 | out: |
4935 | task_event->event_id.header.size = size; | |
60313ebe PZ |
4936 | } |
4937 | ||
cdd6c482 IM |
4938 | static void perf_event_task(struct task_struct *task, |
4939 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 4940 | int new) |
60313ebe | 4941 | { |
9f498cc5 | 4942 | struct perf_task_event task_event; |
60313ebe | 4943 | |
cdd6c482 IM |
4944 | if (!atomic_read(&nr_comm_events) && |
4945 | !atomic_read(&nr_mmap_events) && | |
4946 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
4947 | return; |
4948 | ||
9f498cc5 | 4949 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
4950 | .task = task, |
4951 | .task_ctx = task_ctx, | |
cdd6c482 | 4952 | .event_id = { |
60313ebe | 4953 | .header = { |
cdd6c482 | 4954 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 4955 | .misc = 0, |
cdd6c482 | 4956 | .size = sizeof(task_event.event_id), |
60313ebe | 4957 | }, |
573402db PZ |
4958 | /* .pid */ |
4959 | /* .ppid */ | |
9f498cc5 PZ |
4960 | /* .tid */ |
4961 | /* .ptid */ | |
6f93d0a7 | 4962 | .time = perf_clock(), |
60313ebe PZ |
4963 | }, |
4964 | }; | |
4965 | ||
67516844 | 4966 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
4967 | &task_event, |
4968 | task_ctx); | |
9f498cc5 PZ |
4969 | } |
4970 | ||
cdd6c482 | 4971 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 4972 | { |
cdd6c482 | 4973 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
4974 | } |
4975 | ||
8d1b2d93 PZ |
4976 | /* |
4977 | * comm tracking | |
4978 | */ | |
4979 | ||
4980 | struct perf_comm_event { | |
22a4f650 IM |
4981 | struct task_struct *task; |
4982 | char *comm; | |
8d1b2d93 PZ |
4983 | int comm_size; |
4984 | ||
4985 | struct { | |
4986 | struct perf_event_header header; | |
4987 | ||
4988 | u32 pid; | |
4989 | u32 tid; | |
cdd6c482 | 4990 | } event_id; |
8d1b2d93 PZ |
4991 | }; |
4992 | ||
67516844 JO |
4993 | static int perf_event_comm_match(struct perf_event *event) |
4994 | { | |
4995 | return event->attr.comm; | |
4996 | } | |
4997 | ||
cdd6c482 | 4998 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 4999 | void *data) |
8d1b2d93 | 5000 | { |
52d857a8 | 5001 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5002 | struct perf_output_handle handle; |
c980d109 | 5003 | struct perf_sample_data sample; |
cdd6c482 | 5004 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5005 | int ret; |
5006 | ||
67516844 JO |
5007 | if (!perf_event_comm_match(event)) |
5008 | return; | |
5009 | ||
c980d109 ACM |
5010 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5011 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5012 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5013 | |
5014 | if (ret) | |
c980d109 | 5015 | goto out; |
8d1b2d93 | 5016 | |
cdd6c482 IM |
5017 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5018 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5019 | |
cdd6c482 | 5020 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5021 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5022 | comm_event->comm_size); |
c980d109 ACM |
5023 | |
5024 | perf_event__output_id_sample(event, &handle, &sample); | |
5025 | ||
8d1b2d93 | 5026 | perf_output_end(&handle); |
c980d109 ACM |
5027 | out: |
5028 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5029 | } |
5030 | ||
cdd6c482 | 5031 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5032 | { |
413ee3b4 | 5033 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5034 | unsigned int size; |
8d1b2d93 | 5035 | |
413ee3b4 | 5036 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5037 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5038 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5039 | |
5040 | comm_event->comm = comm; | |
5041 | comm_event->comm_size = size; | |
5042 | ||
cdd6c482 | 5043 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5044 | |
67516844 | 5045 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5046 | comm_event, |
5047 | NULL); | |
8d1b2d93 PZ |
5048 | } |
5049 | ||
cdd6c482 | 5050 | void perf_event_comm(struct task_struct *task) |
8d1b2d93 | 5051 | { |
9ee318a7 | 5052 | struct perf_comm_event comm_event; |
8dc85d54 PZ |
5053 | struct perf_event_context *ctx; |
5054 | int ctxn; | |
9ee318a7 | 5055 | |
c79aa0d9 | 5056 | rcu_read_lock(); |
8dc85d54 PZ |
5057 | for_each_task_context_nr(ctxn) { |
5058 | ctx = task->perf_event_ctxp[ctxn]; | |
5059 | if (!ctx) | |
5060 | continue; | |
9ee318a7 | 5061 | |
8dc85d54 PZ |
5062 | perf_event_enable_on_exec(ctx); |
5063 | } | |
c79aa0d9 | 5064 | rcu_read_unlock(); |
9ee318a7 | 5065 | |
cdd6c482 | 5066 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5067 | return; |
a63eaf34 | 5068 | |
9ee318a7 | 5069 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5070 | .task = task, |
573402db PZ |
5071 | /* .comm */ |
5072 | /* .comm_size */ | |
cdd6c482 | 5073 | .event_id = { |
573402db | 5074 | .header = { |
cdd6c482 | 5075 | .type = PERF_RECORD_COMM, |
573402db PZ |
5076 | .misc = 0, |
5077 | /* .size */ | |
5078 | }, | |
5079 | /* .pid */ | |
5080 | /* .tid */ | |
8d1b2d93 PZ |
5081 | }, |
5082 | }; | |
5083 | ||
cdd6c482 | 5084 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5085 | } |
5086 | ||
0a4a9391 PZ |
5087 | /* |
5088 | * mmap tracking | |
5089 | */ | |
5090 | ||
5091 | struct perf_mmap_event { | |
089dd79d PZ |
5092 | struct vm_area_struct *vma; |
5093 | ||
5094 | const char *file_name; | |
5095 | int file_size; | |
13d7a241 SE |
5096 | int maj, min; |
5097 | u64 ino; | |
5098 | u64 ino_generation; | |
0a4a9391 PZ |
5099 | |
5100 | struct { | |
5101 | struct perf_event_header header; | |
5102 | ||
5103 | u32 pid; | |
5104 | u32 tid; | |
5105 | u64 start; | |
5106 | u64 len; | |
5107 | u64 pgoff; | |
cdd6c482 | 5108 | } event_id; |
0a4a9391 PZ |
5109 | }; |
5110 | ||
67516844 JO |
5111 | static int perf_event_mmap_match(struct perf_event *event, |
5112 | void *data) | |
5113 | { | |
5114 | struct perf_mmap_event *mmap_event = data; | |
5115 | struct vm_area_struct *vma = mmap_event->vma; | |
5116 | int executable = vma->vm_flags & VM_EXEC; | |
5117 | ||
5118 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5119 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5120 | } |
5121 | ||
cdd6c482 | 5122 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5123 | void *data) |
0a4a9391 | 5124 | { |
52d857a8 | 5125 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5126 | struct perf_output_handle handle; |
c980d109 | 5127 | struct perf_sample_data sample; |
cdd6c482 | 5128 | int size = mmap_event->event_id.header.size; |
c980d109 | 5129 | int ret; |
0a4a9391 | 5130 | |
67516844 JO |
5131 | if (!perf_event_mmap_match(event, data)) |
5132 | return; | |
5133 | ||
13d7a241 SE |
5134 | if (event->attr.mmap2) { |
5135 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5136 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5137 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5138 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5139 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
13d7a241 SE |
5140 | } |
5141 | ||
c980d109 ACM |
5142 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5143 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5144 | mmap_event->event_id.header.size); |
0a4a9391 | 5145 | if (ret) |
c980d109 | 5146 | goto out; |
0a4a9391 | 5147 | |
cdd6c482 IM |
5148 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5149 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5150 | |
cdd6c482 | 5151 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5152 | |
5153 | if (event->attr.mmap2) { | |
5154 | perf_output_put(&handle, mmap_event->maj); | |
5155 | perf_output_put(&handle, mmap_event->min); | |
5156 | perf_output_put(&handle, mmap_event->ino); | |
5157 | perf_output_put(&handle, mmap_event->ino_generation); | |
5158 | } | |
5159 | ||
76369139 | 5160 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5161 | mmap_event->file_size); |
c980d109 ACM |
5162 | |
5163 | perf_event__output_id_sample(event, &handle, &sample); | |
5164 | ||
78d613eb | 5165 | perf_output_end(&handle); |
c980d109 ACM |
5166 | out: |
5167 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5168 | } |
5169 | ||
cdd6c482 | 5170 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5171 | { |
089dd79d PZ |
5172 | struct vm_area_struct *vma = mmap_event->vma; |
5173 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5174 | int maj = 0, min = 0; |
5175 | u64 ino = 0, gen = 0; | |
0a4a9391 PZ |
5176 | unsigned int size; |
5177 | char tmp[16]; | |
5178 | char *buf = NULL; | |
2c42cfbf | 5179 | char *name; |
413ee3b4 | 5180 | |
0a4a9391 | 5181 | if (file) { |
13d7a241 SE |
5182 | struct inode *inode; |
5183 | dev_t dev; | |
3ea2f2b9 | 5184 | |
2c42cfbf | 5185 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5186 | if (!buf) { |
c7e548b4 ON |
5187 | name = "//enomem"; |
5188 | goto cpy_name; | |
0a4a9391 | 5189 | } |
413ee3b4 | 5190 | /* |
3ea2f2b9 | 5191 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5192 | * need to add enough zero bytes after the string to handle |
5193 | * the 64bit alignment we do later. | |
5194 | */ | |
3ea2f2b9 | 5195 | name = d_path(&file->f_path, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5196 | if (IS_ERR(name)) { |
c7e548b4 ON |
5197 | name = "//toolong"; |
5198 | goto cpy_name; | |
0a4a9391 | 5199 | } |
13d7a241 SE |
5200 | inode = file_inode(vma->vm_file); |
5201 | dev = inode->i_sb->s_dev; | |
5202 | ino = inode->i_ino; | |
5203 | gen = inode->i_generation; | |
5204 | maj = MAJOR(dev); | |
5205 | min = MINOR(dev); | |
c7e548b4 | 5206 | goto got_name; |
0a4a9391 | 5207 | } else { |
2c42cfbf | 5208 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
5209 | if (name) |
5210 | goto cpy_name; | |
089dd79d | 5211 | |
32c5fb7e | 5212 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 5213 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
5214 | name = "[heap]"; |
5215 | goto cpy_name; | |
32c5fb7e ON |
5216 | } |
5217 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 5218 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
5219 | name = "[stack]"; |
5220 | goto cpy_name; | |
089dd79d PZ |
5221 | } |
5222 | ||
c7e548b4 ON |
5223 | name = "//anon"; |
5224 | goto cpy_name; | |
0a4a9391 PZ |
5225 | } |
5226 | ||
c7e548b4 ON |
5227 | cpy_name: |
5228 | strlcpy(tmp, name, sizeof(tmp)); | |
5229 | name = tmp; | |
0a4a9391 | 5230 | got_name: |
2c42cfbf PZ |
5231 | /* |
5232 | * Since our buffer works in 8 byte units we need to align our string | |
5233 | * size to a multiple of 8. However, we must guarantee the tail end is | |
5234 | * zero'd out to avoid leaking random bits to userspace. | |
5235 | */ | |
5236 | size = strlen(name)+1; | |
5237 | while (!IS_ALIGNED(size, sizeof(u64))) | |
5238 | name[size++] = '\0'; | |
0a4a9391 PZ |
5239 | |
5240 | mmap_event->file_name = name; | |
5241 | mmap_event->file_size = size; | |
13d7a241 SE |
5242 | mmap_event->maj = maj; |
5243 | mmap_event->min = min; | |
5244 | mmap_event->ino = ino; | |
5245 | mmap_event->ino_generation = gen; | |
0a4a9391 | 5246 | |
2fe85427 SE |
5247 | if (!(vma->vm_flags & VM_EXEC)) |
5248 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
5249 | ||
cdd6c482 | 5250 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 5251 | |
67516844 | 5252 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
5253 | mmap_event, |
5254 | NULL); | |
665c2142 | 5255 | |
0a4a9391 PZ |
5256 | kfree(buf); |
5257 | } | |
5258 | ||
3af9e859 | 5259 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 5260 | { |
9ee318a7 PZ |
5261 | struct perf_mmap_event mmap_event; |
5262 | ||
cdd6c482 | 5263 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
5264 | return; |
5265 | ||
5266 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 5267 | .vma = vma, |
573402db PZ |
5268 | /* .file_name */ |
5269 | /* .file_size */ | |
cdd6c482 | 5270 | .event_id = { |
573402db | 5271 | .header = { |
cdd6c482 | 5272 | .type = PERF_RECORD_MMAP, |
39447b38 | 5273 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
5274 | /* .size */ |
5275 | }, | |
5276 | /* .pid */ | |
5277 | /* .tid */ | |
089dd79d PZ |
5278 | .start = vma->vm_start, |
5279 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 5280 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 5281 | }, |
13d7a241 SE |
5282 | /* .maj (attr_mmap2 only) */ |
5283 | /* .min (attr_mmap2 only) */ | |
5284 | /* .ino (attr_mmap2 only) */ | |
5285 | /* .ino_generation (attr_mmap2 only) */ | |
0a4a9391 PZ |
5286 | }; |
5287 | ||
cdd6c482 | 5288 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
5289 | } |
5290 | ||
a78ac325 PZ |
5291 | /* |
5292 | * IRQ throttle logging | |
5293 | */ | |
5294 | ||
cdd6c482 | 5295 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
5296 | { |
5297 | struct perf_output_handle handle; | |
c980d109 | 5298 | struct perf_sample_data sample; |
a78ac325 PZ |
5299 | int ret; |
5300 | ||
5301 | struct { | |
5302 | struct perf_event_header header; | |
5303 | u64 time; | |
cca3f454 | 5304 | u64 id; |
7f453c24 | 5305 | u64 stream_id; |
a78ac325 PZ |
5306 | } throttle_event = { |
5307 | .header = { | |
cdd6c482 | 5308 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
5309 | .misc = 0, |
5310 | .size = sizeof(throttle_event), | |
5311 | }, | |
def0a9b2 | 5312 | .time = perf_clock(), |
cdd6c482 IM |
5313 | .id = primary_event_id(event), |
5314 | .stream_id = event->id, | |
a78ac325 PZ |
5315 | }; |
5316 | ||
966ee4d6 | 5317 | if (enable) |
cdd6c482 | 5318 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 5319 | |
c980d109 ACM |
5320 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
5321 | ||
5322 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5323 | throttle_event.header.size); |
a78ac325 PZ |
5324 | if (ret) |
5325 | return; | |
5326 | ||
5327 | perf_output_put(&handle, throttle_event); | |
c980d109 | 5328 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
5329 | perf_output_end(&handle); |
5330 | } | |
5331 | ||
f6c7d5fe | 5332 | /* |
cdd6c482 | 5333 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
5334 | */ |
5335 | ||
a8b0ca17 | 5336 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
5337 | int throttle, struct perf_sample_data *data, |
5338 | struct pt_regs *regs) | |
f6c7d5fe | 5339 | { |
cdd6c482 IM |
5340 | int events = atomic_read(&event->event_limit); |
5341 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 5342 | u64 seq; |
79f14641 PZ |
5343 | int ret = 0; |
5344 | ||
96398826 PZ |
5345 | /* |
5346 | * Non-sampling counters might still use the PMI to fold short | |
5347 | * hardware counters, ignore those. | |
5348 | */ | |
5349 | if (unlikely(!is_sampling_event(event))) | |
5350 | return 0; | |
5351 | ||
e050e3f0 SE |
5352 | seq = __this_cpu_read(perf_throttled_seq); |
5353 | if (seq != hwc->interrupts_seq) { | |
5354 | hwc->interrupts_seq = seq; | |
5355 | hwc->interrupts = 1; | |
5356 | } else { | |
5357 | hwc->interrupts++; | |
5358 | if (unlikely(throttle | |
5359 | && hwc->interrupts >= max_samples_per_tick)) { | |
5360 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
5361 | hwc->interrupts = MAX_INTERRUPTS; |
5362 | perf_log_throttle(event, 0); | |
d84153d6 | 5363 | tick_nohz_full_kick(); |
a78ac325 PZ |
5364 | ret = 1; |
5365 | } | |
e050e3f0 | 5366 | } |
60db5e09 | 5367 | |
cdd6c482 | 5368 | if (event->attr.freq) { |
def0a9b2 | 5369 | u64 now = perf_clock(); |
abd50713 | 5370 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 5371 | |
abd50713 | 5372 | hwc->freq_time_stamp = now; |
bd2b5b12 | 5373 | |
abd50713 | 5374 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 5375 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
5376 | } |
5377 | ||
2023b359 PZ |
5378 | /* |
5379 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 5380 | * events |
2023b359 PZ |
5381 | */ |
5382 | ||
cdd6c482 IM |
5383 | event->pending_kill = POLL_IN; |
5384 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 5385 | ret = 1; |
cdd6c482 | 5386 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
5387 | event->pending_disable = 1; |
5388 | irq_work_queue(&event->pending); | |
79f14641 PZ |
5389 | } |
5390 | ||
453f19ee | 5391 | if (event->overflow_handler) |
a8b0ca17 | 5392 | event->overflow_handler(event, data, regs); |
453f19ee | 5393 | else |
a8b0ca17 | 5394 | perf_event_output(event, data, regs); |
453f19ee | 5395 | |
f506b3dc | 5396 | if (event->fasync && event->pending_kill) { |
a8b0ca17 PZ |
5397 | event->pending_wakeup = 1; |
5398 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
5399 | } |
5400 | ||
79f14641 | 5401 | return ret; |
f6c7d5fe PZ |
5402 | } |
5403 | ||
a8b0ca17 | 5404 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
5405 | struct perf_sample_data *data, |
5406 | struct pt_regs *regs) | |
850bc73f | 5407 | { |
a8b0ca17 | 5408 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
5409 | } |
5410 | ||
15dbf27c | 5411 | /* |
cdd6c482 | 5412 | * Generic software event infrastructure |
15dbf27c PZ |
5413 | */ |
5414 | ||
b28ab83c PZ |
5415 | struct swevent_htable { |
5416 | struct swevent_hlist *swevent_hlist; | |
5417 | struct mutex hlist_mutex; | |
5418 | int hlist_refcount; | |
5419 | ||
5420 | /* Recursion avoidance in each contexts */ | |
5421 | int recursion[PERF_NR_CONTEXTS]; | |
5422 | }; | |
5423 | ||
5424 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
5425 | ||
7b4b6658 | 5426 | /* |
cdd6c482 IM |
5427 | * We directly increment event->count and keep a second value in |
5428 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
5429 | * is kept in the range [-sample_period, 0] so that we can use the |
5430 | * sign as trigger. | |
5431 | */ | |
5432 | ||
ab573844 | 5433 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 5434 | { |
cdd6c482 | 5435 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
5436 | u64 period = hwc->last_period; |
5437 | u64 nr, offset; | |
5438 | s64 old, val; | |
5439 | ||
5440 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
5441 | |
5442 | again: | |
e7850595 | 5443 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
5444 | if (val < 0) |
5445 | return 0; | |
15dbf27c | 5446 | |
7b4b6658 PZ |
5447 | nr = div64_u64(period + val, period); |
5448 | offset = nr * period; | |
5449 | val -= offset; | |
e7850595 | 5450 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 5451 | goto again; |
15dbf27c | 5452 | |
7b4b6658 | 5453 | return nr; |
15dbf27c PZ |
5454 | } |
5455 | ||
0cff784a | 5456 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 5457 | struct perf_sample_data *data, |
5622f295 | 5458 | struct pt_regs *regs) |
15dbf27c | 5459 | { |
cdd6c482 | 5460 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 5461 | int throttle = 0; |
15dbf27c | 5462 | |
0cff784a PZ |
5463 | if (!overflow) |
5464 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 5465 | |
7b4b6658 PZ |
5466 | if (hwc->interrupts == MAX_INTERRUPTS) |
5467 | return; | |
15dbf27c | 5468 | |
7b4b6658 | 5469 | for (; overflow; overflow--) { |
a8b0ca17 | 5470 | if (__perf_event_overflow(event, throttle, |
5622f295 | 5471 | data, regs)) { |
7b4b6658 PZ |
5472 | /* |
5473 | * We inhibit the overflow from happening when | |
5474 | * hwc->interrupts == MAX_INTERRUPTS. | |
5475 | */ | |
5476 | break; | |
5477 | } | |
cf450a73 | 5478 | throttle = 1; |
7b4b6658 | 5479 | } |
15dbf27c PZ |
5480 | } |
5481 | ||
a4eaf7f1 | 5482 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 5483 | struct perf_sample_data *data, |
5622f295 | 5484 | struct pt_regs *regs) |
7b4b6658 | 5485 | { |
cdd6c482 | 5486 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 5487 | |
e7850595 | 5488 | local64_add(nr, &event->count); |
d6d020e9 | 5489 | |
0cff784a PZ |
5490 | if (!regs) |
5491 | return; | |
5492 | ||
6c7e550f | 5493 | if (!is_sampling_event(event)) |
7b4b6658 | 5494 | return; |
d6d020e9 | 5495 | |
5d81e5cf AV |
5496 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
5497 | data->period = nr; | |
5498 | return perf_swevent_overflow(event, 1, data, regs); | |
5499 | } else | |
5500 | data->period = event->hw.last_period; | |
5501 | ||
0cff784a | 5502 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 5503 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 5504 | |
e7850595 | 5505 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 5506 | return; |
df1a132b | 5507 | |
a8b0ca17 | 5508 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
5509 | } |
5510 | ||
f5ffe02e FW |
5511 | static int perf_exclude_event(struct perf_event *event, |
5512 | struct pt_regs *regs) | |
5513 | { | |
a4eaf7f1 | 5514 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 5515 | return 1; |
a4eaf7f1 | 5516 | |
f5ffe02e FW |
5517 | if (regs) { |
5518 | if (event->attr.exclude_user && user_mode(regs)) | |
5519 | return 1; | |
5520 | ||
5521 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
5522 | return 1; | |
5523 | } | |
5524 | ||
5525 | return 0; | |
5526 | } | |
5527 | ||
cdd6c482 | 5528 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 5529 | enum perf_type_id type, |
6fb2915d LZ |
5530 | u32 event_id, |
5531 | struct perf_sample_data *data, | |
5532 | struct pt_regs *regs) | |
15dbf27c | 5533 | { |
cdd6c482 | 5534 | if (event->attr.type != type) |
a21ca2ca | 5535 | return 0; |
f5ffe02e | 5536 | |
cdd6c482 | 5537 | if (event->attr.config != event_id) |
15dbf27c PZ |
5538 | return 0; |
5539 | ||
f5ffe02e FW |
5540 | if (perf_exclude_event(event, regs)) |
5541 | return 0; | |
15dbf27c PZ |
5542 | |
5543 | return 1; | |
5544 | } | |
5545 | ||
76e1d904 FW |
5546 | static inline u64 swevent_hash(u64 type, u32 event_id) |
5547 | { | |
5548 | u64 val = event_id | (type << 32); | |
5549 | ||
5550 | return hash_64(val, SWEVENT_HLIST_BITS); | |
5551 | } | |
5552 | ||
49f135ed FW |
5553 | static inline struct hlist_head * |
5554 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 5555 | { |
49f135ed FW |
5556 | u64 hash = swevent_hash(type, event_id); |
5557 | ||
5558 | return &hlist->heads[hash]; | |
5559 | } | |
76e1d904 | 5560 | |
49f135ed FW |
5561 | /* For the read side: events when they trigger */ |
5562 | static inline struct hlist_head * | |
b28ab83c | 5563 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
5564 | { |
5565 | struct swevent_hlist *hlist; | |
76e1d904 | 5566 | |
b28ab83c | 5567 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
5568 | if (!hlist) |
5569 | return NULL; | |
5570 | ||
49f135ed FW |
5571 | return __find_swevent_head(hlist, type, event_id); |
5572 | } | |
5573 | ||
5574 | /* For the event head insertion and removal in the hlist */ | |
5575 | static inline struct hlist_head * | |
b28ab83c | 5576 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
5577 | { |
5578 | struct swevent_hlist *hlist; | |
5579 | u32 event_id = event->attr.config; | |
5580 | u64 type = event->attr.type; | |
5581 | ||
5582 | /* | |
5583 | * Event scheduling is always serialized against hlist allocation | |
5584 | * and release. Which makes the protected version suitable here. | |
5585 | * The context lock guarantees that. | |
5586 | */ | |
b28ab83c | 5587 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
5588 | lockdep_is_held(&event->ctx->lock)); |
5589 | if (!hlist) | |
5590 | return NULL; | |
5591 | ||
5592 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
5593 | } |
5594 | ||
5595 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 5596 | u64 nr, |
76e1d904 FW |
5597 | struct perf_sample_data *data, |
5598 | struct pt_regs *regs) | |
15dbf27c | 5599 | { |
b28ab83c | 5600 | struct swevent_htable *swhash = &__get_cpu_var(swevent_htable); |
cdd6c482 | 5601 | struct perf_event *event; |
76e1d904 | 5602 | struct hlist_head *head; |
15dbf27c | 5603 | |
76e1d904 | 5604 | rcu_read_lock(); |
b28ab83c | 5605 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
5606 | if (!head) |
5607 | goto end; | |
5608 | ||
b67bfe0d | 5609 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 5610 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 5611 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 5612 | } |
76e1d904 FW |
5613 | end: |
5614 | rcu_read_unlock(); | |
15dbf27c PZ |
5615 | } |
5616 | ||
4ed7c92d | 5617 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 5618 | { |
b28ab83c | 5619 | struct swevent_htable *swhash = &__get_cpu_var(swevent_htable); |
96f6d444 | 5620 | |
b28ab83c | 5621 | return get_recursion_context(swhash->recursion); |
96f6d444 | 5622 | } |
645e8cc0 | 5623 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 5624 | |
fa9f90be | 5625 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 5626 | { |
b28ab83c | 5627 | struct swevent_htable *swhash = &__get_cpu_var(swevent_htable); |
927c7a9e | 5628 | |
b28ab83c | 5629 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 5630 | } |
15dbf27c | 5631 | |
a8b0ca17 | 5632 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 5633 | { |
a4234bfc | 5634 | struct perf_sample_data data; |
4ed7c92d PZ |
5635 | int rctx; |
5636 | ||
1c024eca | 5637 | preempt_disable_notrace(); |
4ed7c92d PZ |
5638 | rctx = perf_swevent_get_recursion_context(); |
5639 | if (rctx < 0) | |
5640 | return; | |
a4234bfc | 5641 | |
fd0d000b | 5642 | perf_sample_data_init(&data, addr, 0); |
92bf309a | 5643 | |
a8b0ca17 | 5644 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
4ed7c92d PZ |
5645 | |
5646 | perf_swevent_put_recursion_context(rctx); | |
1c024eca | 5647 | preempt_enable_notrace(); |
b8e83514 PZ |
5648 | } |
5649 | ||
cdd6c482 | 5650 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 5651 | { |
15dbf27c PZ |
5652 | } |
5653 | ||
a4eaf7f1 | 5654 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 5655 | { |
b28ab83c | 5656 | struct swevent_htable *swhash = &__get_cpu_var(swevent_htable); |
cdd6c482 | 5657 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
5658 | struct hlist_head *head; |
5659 | ||
6c7e550f | 5660 | if (is_sampling_event(event)) { |
7b4b6658 | 5661 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 5662 | perf_swevent_set_period(event); |
7b4b6658 | 5663 | } |
76e1d904 | 5664 | |
a4eaf7f1 PZ |
5665 | hwc->state = !(flags & PERF_EF_START); |
5666 | ||
b28ab83c | 5667 | head = find_swevent_head(swhash, event); |
76e1d904 FW |
5668 | if (WARN_ON_ONCE(!head)) |
5669 | return -EINVAL; | |
5670 | ||
5671 | hlist_add_head_rcu(&event->hlist_entry, head); | |
5672 | ||
15dbf27c PZ |
5673 | return 0; |
5674 | } | |
5675 | ||
a4eaf7f1 | 5676 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 5677 | { |
76e1d904 | 5678 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
5679 | } |
5680 | ||
a4eaf7f1 | 5681 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 5682 | { |
a4eaf7f1 | 5683 | event->hw.state = 0; |
d6d020e9 | 5684 | } |
aa9c4c0f | 5685 | |
a4eaf7f1 | 5686 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 5687 | { |
a4eaf7f1 | 5688 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
5689 | } |
5690 | ||
49f135ed FW |
5691 | /* Deref the hlist from the update side */ |
5692 | static inline struct swevent_hlist * | |
b28ab83c | 5693 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 5694 | { |
b28ab83c PZ |
5695 | return rcu_dereference_protected(swhash->swevent_hlist, |
5696 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
5697 | } |
5698 | ||
b28ab83c | 5699 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 5700 | { |
b28ab83c | 5701 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 5702 | |
49f135ed | 5703 | if (!hlist) |
76e1d904 FW |
5704 | return; |
5705 | ||
b28ab83c | 5706 | rcu_assign_pointer(swhash->swevent_hlist, NULL); |
fa4bbc4c | 5707 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
5708 | } |
5709 | ||
5710 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
5711 | { | |
b28ab83c | 5712 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 5713 | |
b28ab83c | 5714 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 5715 | |
b28ab83c PZ |
5716 | if (!--swhash->hlist_refcount) |
5717 | swevent_hlist_release(swhash); | |
76e1d904 | 5718 | |
b28ab83c | 5719 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
5720 | } |
5721 | ||
5722 | static void swevent_hlist_put(struct perf_event *event) | |
5723 | { | |
5724 | int cpu; | |
5725 | ||
76e1d904 FW |
5726 | for_each_possible_cpu(cpu) |
5727 | swevent_hlist_put_cpu(event, cpu); | |
5728 | } | |
5729 | ||
5730 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
5731 | { | |
b28ab83c | 5732 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
5733 | int err = 0; |
5734 | ||
b28ab83c | 5735 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 5736 | |
b28ab83c | 5737 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
5738 | struct swevent_hlist *hlist; |
5739 | ||
5740 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
5741 | if (!hlist) { | |
5742 | err = -ENOMEM; | |
5743 | goto exit; | |
5744 | } | |
b28ab83c | 5745 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 5746 | } |
b28ab83c | 5747 | swhash->hlist_refcount++; |
9ed6060d | 5748 | exit: |
b28ab83c | 5749 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
5750 | |
5751 | return err; | |
5752 | } | |
5753 | ||
5754 | static int swevent_hlist_get(struct perf_event *event) | |
5755 | { | |
5756 | int err; | |
5757 | int cpu, failed_cpu; | |
5758 | ||
76e1d904 FW |
5759 | get_online_cpus(); |
5760 | for_each_possible_cpu(cpu) { | |
5761 | err = swevent_hlist_get_cpu(event, cpu); | |
5762 | if (err) { | |
5763 | failed_cpu = cpu; | |
5764 | goto fail; | |
5765 | } | |
5766 | } | |
5767 | put_online_cpus(); | |
5768 | ||
5769 | return 0; | |
9ed6060d | 5770 | fail: |
76e1d904 FW |
5771 | for_each_possible_cpu(cpu) { |
5772 | if (cpu == failed_cpu) | |
5773 | break; | |
5774 | swevent_hlist_put_cpu(event, cpu); | |
5775 | } | |
5776 | ||
5777 | put_online_cpus(); | |
5778 | return err; | |
5779 | } | |
5780 | ||
c5905afb | 5781 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 5782 | |
b0a873eb PZ |
5783 | static void sw_perf_event_destroy(struct perf_event *event) |
5784 | { | |
5785 | u64 event_id = event->attr.config; | |
95476b64 | 5786 | |
b0a873eb PZ |
5787 | WARN_ON(event->parent); |
5788 | ||
c5905afb | 5789 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
5790 | swevent_hlist_put(event); |
5791 | } | |
5792 | ||
5793 | static int perf_swevent_init(struct perf_event *event) | |
5794 | { | |
8176cced | 5795 | u64 event_id = event->attr.config; |
b0a873eb PZ |
5796 | |
5797 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
5798 | return -ENOENT; | |
5799 | ||
2481c5fa SE |
5800 | /* |
5801 | * no branch sampling for software events | |
5802 | */ | |
5803 | if (has_branch_stack(event)) | |
5804 | return -EOPNOTSUPP; | |
5805 | ||
b0a873eb PZ |
5806 | switch (event_id) { |
5807 | case PERF_COUNT_SW_CPU_CLOCK: | |
5808 | case PERF_COUNT_SW_TASK_CLOCK: | |
5809 | return -ENOENT; | |
5810 | ||
5811 | default: | |
5812 | break; | |
5813 | } | |
5814 | ||
ce677831 | 5815 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
5816 | return -ENOENT; |
5817 | ||
5818 | if (!event->parent) { | |
5819 | int err; | |
5820 | ||
5821 | err = swevent_hlist_get(event); | |
5822 | if (err) | |
5823 | return err; | |
5824 | ||
c5905afb | 5825 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
5826 | event->destroy = sw_perf_event_destroy; |
5827 | } | |
5828 | ||
5829 | return 0; | |
5830 | } | |
5831 | ||
35edc2a5 PZ |
5832 | static int perf_swevent_event_idx(struct perf_event *event) |
5833 | { | |
5834 | return 0; | |
5835 | } | |
5836 | ||
b0a873eb | 5837 | static struct pmu perf_swevent = { |
89a1e187 | 5838 | .task_ctx_nr = perf_sw_context, |
95476b64 | 5839 | |
b0a873eb | 5840 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
5841 | .add = perf_swevent_add, |
5842 | .del = perf_swevent_del, | |
5843 | .start = perf_swevent_start, | |
5844 | .stop = perf_swevent_stop, | |
1c024eca | 5845 | .read = perf_swevent_read, |
35edc2a5 PZ |
5846 | |
5847 | .event_idx = perf_swevent_event_idx, | |
1c024eca PZ |
5848 | }; |
5849 | ||
b0a873eb PZ |
5850 | #ifdef CONFIG_EVENT_TRACING |
5851 | ||
1c024eca PZ |
5852 | static int perf_tp_filter_match(struct perf_event *event, |
5853 | struct perf_sample_data *data) | |
5854 | { | |
5855 | void *record = data->raw->data; | |
5856 | ||
5857 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) | |
5858 | return 1; | |
5859 | return 0; | |
5860 | } | |
5861 | ||
5862 | static int perf_tp_event_match(struct perf_event *event, | |
5863 | struct perf_sample_data *data, | |
5864 | struct pt_regs *regs) | |
5865 | { | |
a0f7d0f7 FW |
5866 | if (event->hw.state & PERF_HES_STOPPED) |
5867 | return 0; | |
580d607c PZ |
5868 | /* |
5869 | * All tracepoints are from kernel-space. | |
5870 | */ | |
5871 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
5872 | return 0; |
5873 | ||
5874 | if (!perf_tp_filter_match(event, data)) | |
5875 | return 0; | |
5876 | ||
5877 | return 1; | |
5878 | } | |
5879 | ||
5880 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
5881 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
5882 | struct task_struct *task) | |
95476b64 FW |
5883 | { |
5884 | struct perf_sample_data data; | |
1c024eca | 5885 | struct perf_event *event; |
1c024eca | 5886 | |
95476b64 FW |
5887 | struct perf_raw_record raw = { |
5888 | .size = entry_size, | |
5889 | .data = record, | |
5890 | }; | |
5891 | ||
fd0d000b | 5892 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
5893 | data.raw = &raw; |
5894 | ||
b67bfe0d | 5895 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 5896 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 5897 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 5898 | } |
ecc55f84 | 5899 | |
e6dab5ff AV |
5900 | /* |
5901 | * If we got specified a target task, also iterate its context and | |
5902 | * deliver this event there too. | |
5903 | */ | |
5904 | if (task && task != current) { | |
5905 | struct perf_event_context *ctx; | |
5906 | struct trace_entry *entry = record; | |
5907 | ||
5908 | rcu_read_lock(); | |
5909 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
5910 | if (!ctx) | |
5911 | goto unlock; | |
5912 | ||
5913 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5914 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
5915 | continue; | |
5916 | if (event->attr.config != entry->type) | |
5917 | continue; | |
5918 | if (perf_tp_event_match(event, &data, regs)) | |
5919 | perf_swevent_event(event, count, &data, regs); | |
5920 | } | |
5921 | unlock: | |
5922 | rcu_read_unlock(); | |
5923 | } | |
5924 | ||
ecc55f84 | 5925 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
5926 | } |
5927 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
5928 | ||
cdd6c482 | 5929 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 5930 | { |
1c024eca | 5931 | perf_trace_destroy(event); |
e077df4f PZ |
5932 | } |
5933 | ||
b0a873eb | 5934 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 5935 | { |
76e1d904 FW |
5936 | int err; |
5937 | ||
b0a873eb PZ |
5938 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
5939 | return -ENOENT; | |
5940 | ||
2481c5fa SE |
5941 | /* |
5942 | * no branch sampling for tracepoint events | |
5943 | */ | |
5944 | if (has_branch_stack(event)) | |
5945 | return -EOPNOTSUPP; | |
5946 | ||
1c024eca PZ |
5947 | err = perf_trace_init(event); |
5948 | if (err) | |
b0a873eb | 5949 | return err; |
e077df4f | 5950 | |
cdd6c482 | 5951 | event->destroy = tp_perf_event_destroy; |
e077df4f | 5952 | |
b0a873eb PZ |
5953 | return 0; |
5954 | } | |
5955 | ||
5956 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
5957 | .task_ctx_nr = perf_sw_context, |
5958 | ||
b0a873eb | 5959 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
5960 | .add = perf_trace_add, |
5961 | .del = perf_trace_del, | |
5962 | .start = perf_swevent_start, | |
5963 | .stop = perf_swevent_stop, | |
b0a873eb | 5964 | .read = perf_swevent_read, |
35edc2a5 PZ |
5965 | |
5966 | .event_idx = perf_swevent_event_idx, | |
b0a873eb PZ |
5967 | }; |
5968 | ||
5969 | static inline void perf_tp_register(void) | |
5970 | { | |
2e80a82a | 5971 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 5972 | } |
6fb2915d LZ |
5973 | |
5974 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
5975 | { | |
5976 | char *filter_str; | |
5977 | int ret; | |
5978 | ||
5979 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
5980 | return -EINVAL; | |
5981 | ||
5982 | filter_str = strndup_user(arg, PAGE_SIZE); | |
5983 | if (IS_ERR(filter_str)) | |
5984 | return PTR_ERR(filter_str); | |
5985 | ||
5986 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
5987 | ||
5988 | kfree(filter_str); | |
5989 | return ret; | |
5990 | } | |
5991 | ||
5992 | static void perf_event_free_filter(struct perf_event *event) | |
5993 | { | |
5994 | ftrace_profile_free_filter(event); | |
5995 | } | |
5996 | ||
e077df4f | 5997 | #else |
6fb2915d | 5998 | |
b0a873eb | 5999 | static inline void perf_tp_register(void) |
e077df4f | 6000 | { |
e077df4f | 6001 | } |
6fb2915d LZ |
6002 | |
6003 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6004 | { | |
6005 | return -ENOENT; | |
6006 | } | |
6007 | ||
6008 | static void perf_event_free_filter(struct perf_event *event) | |
6009 | { | |
6010 | } | |
6011 | ||
07b139c8 | 6012 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 6013 | |
24f1e32c | 6014 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 6015 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 6016 | { |
f5ffe02e FW |
6017 | struct perf_sample_data sample; |
6018 | struct pt_regs *regs = data; | |
6019 | ||
fd0d000b | 6020 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 6021 | |
a4eaf7f1 | 6022 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 6023 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
6024 | } |
6025 | #endif | |
6026 | ||
b0a873eb PZ |
6027 | /* |
6028 | * hrtimer based swevent callback | |
6029 | */ | |
f29ac756 | 6030 | |
b0a873eb | 6031 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 6032 | { |
b0a873eb PZ |
6033 | enum hrtimer_restart ret = HRTIMER_RESTART; |
6034 | struct perf_sample_data data; | |
6035 | struct pt_regs *regs; | |
6036 | struct perf_event *event; | |
6037 | u64 period; | |
f29ac756 | 6038 | |
b0a873eb | 6039 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
6040 | |
6041 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
6042 | return HRTIMER_NORESTART; | |
6043 | ||
b0a873eb | 6044 | event->pmu->read(event); |
f344011c | 6045 | |
fd0d000b | 6046 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
6047 | regs = get_irq_regs(); |
6048 | ||
6049 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 6050 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 6051 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
6052 | ret = HRTIMER_NORESTART; |
6053 | } | |
24f1e32c | 6054 | |
b0a873eb PZ |
6055 | period = max_t(u64, 10000, event->hw.sample_period); |
6056 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 6057 | |
b0a873eb | 6058 | return ret; |
f29ac756 PZ |
6059 | } |
6060 | ||
b0a873eb | 6061 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 6062 | { |
b0a873eb | 6063 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
6064 | s64 period; |
6065 | ||
6066 | if (!is_sampling_event(event)) | |
6067 | return; | |
f5ffe02e | 6068 | |
5d508e82 FBH |
6069 | period = local64_read(&hwc->period_left); |
6070 | if (period) { | |
6071 | if (period < 0) | |
6072 | period = 10000; | |
fa407f35 | 6073 | |
5d508e82 FBH |
6074 | local64_set(&hwc->period_left, 0); |
6075 | } else { | |
6076 | period = max_t(u64, 10000, hwc->sample_period); | |
6077 | } | |
6078 | __hrtimer_start_range_ns(&hwc->hrtimer, | |
b0a873eb | 6079 | ns_to_ktime(period), 0, |
b5ab4cd5 | 6080 | HRTIMER_MODE_REL_PINNED, 0); |
24f1e32c | 6081 | } |
b0a873eb PZ |
6082 | |
6083 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 6084 | { |
b0a873eb PZ |
6085 | struct hw_perf_event *hwc = &event->hw; |
6086 | ||
6c7e550f | 6087 | if (is_sampling_event(event)) { |
b0a873eb | 6088 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 6089 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
6090 | |
6091 | hrtimer_cancel(&hwc->hrtimer); | |
6092 | } | |
24f1e32c FW |
6093 | } |
6094 | ||
ba3dd36c PZ |
6095 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
6096 | { | |
6097 | struct hw_perf_event *hwc = &event->hw; | |
6098 | ||
6099 | if (!is_sampling_event(event)) | |
6100 | return; | |
6101 | ||
6102 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
6103 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
6104 | ||
6105 | /* | |
6106 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
6107 | * mapping and avoid the whole period adjust feedback stuff. | |
6108 | */ | |
6109 | if (event->attr.freq) { | |
6110 | long freq = event->attr.sample_freq; | |
6111 | ||
6112 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
6113 | hwc->sample_period = event->attr.sample_period; | |
6114 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 6115 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
6116 | event->attr.freq = 0; |
6117 | } | |
6118 | } | |
6119 | ||
b0a873eb PZ |
6120 | /* |
6121 | * Software event: cpu wall time clock | |
6122 | */ | |
6123 | ||
6124 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 6125 | { |
b0a873eb PZ |
6126 | s64 prev; |
6127 | u64 now; | |
6128 | ||
a4eaf7f1 | 6129 | now = local_clock(); |
b0a873eb PZ |
6130 | prev = local64_xchg(&event->hw.prev_count, now); |
6131 | local64_add(now - prev, &event->count); | |
24f1e32c | 6132 | } |
24f1e32c | 6133 | |
a4eaf7f1 | 6134 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 6135 | { |
a4eaf7f1 | 6136 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 6137 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
6138 | } |
6139 | ||
a4eaf7f1 | 6140 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 6141 | { |
b0a873eb PZ |
6142 | perf_swevent_cancel_hrtimer(event); |
6143 | cpu_clock_event_update(event); | |
6144 | } | |
f29ac756 | 6145 | |
a4eaf7f1 PZ |
6146 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
6147 | { | |
6148 | if (flags & PERF_EF_START) | |
6149 | cpu_clock_event_start(event, flags); | |
6150 | ||
6151 | return 0; | |
6152 | } | |
6153 | ||
6154 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
6155 | { | |
6156 | cpu_clock_event_stop(event, flags); | |
6157 | } | |
6158 | ||
b0a873eb PZ |
6159 | static void cpu_clock_event_read(struct perf_event *event) |
6160 | { | |
6161 | cpu_clock_event_update(event); | |
6162 | } | |
f344011c | 6163 | |
b0a873eb PZ |
6164 | static int cpu_clock_event_init(struct perf_event *event) |
6165 | { | |
6166 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6167 | return -ENOENT; | |
6168 | ||
6169 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
6170 | return -ENOENT; | |
6171 | ||
2481c5fa SE |
6172 | /* |
6173 | * no branch sampling for software events | |
6174 | */ | |
6175 | if (has_branch_stack(event)) | |
6176 | return -EOPNOTSUPP; | |
6177 | ||
ba3dd36c PZ |
6178 | perf_swevent_init_hrtimer(event); |
6179 | ||
b0a873eb | 6180 | return 0; |
f29ac756 PZ |
6181 | } |
6182 | ||
b0a873eb | 6183 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
6184 | .task_ctx_nr = perf_sw_context, |
6185 | ||
b0a873eb | 6186 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
6187 | .add = cpu_clock_event_add, |
6188 | .del = cpu_clock_event_del, | |
6189 | .start = cpu_clock_event_start, | |
6190 | .stop = cpu_clock_event_stop, | |
b0a873eb | 6191 | .read = cpu_clock_event_read, |
35edc2a5 PZ |
6192 | |
6193 | .event_idx = perf_swevent_event_idx, | |
b0a873eb PZ |
6194 | }; |
6195 | ||
6196 | /* | |
6197 | * Software event: task time clock | |
6198 | */ | |
6199 | ||
6200 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 6201 | { |
b0a873eb PZ |
6202 | u64 prev; |
6203 | s64 delta; | |
5c92d124 | 6204 | |
b0a873eb PZ |
6205 | prev = local64_xchg(&event->hw.prev_count, now); |
6206 | delta = now - prev; | |
6207 | local64_add(delta, &event->count); | |
6208 | } | |
5c92d124 | 6209 | |
a4eaf7f1 | 6210 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 6211 | { |
a4eaf7f1 | 6212 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 6213 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
6214 | } |
6215 | ||
a4eaf7f1 | 6216 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
6217 | { |
6218 | perf_swevent_cancel_hrtimer(event); | |
6219 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
6220 | } |
6221 | ||
6222 | static int task_clock_event_add(struct perf_event *event, int flags) | |
6223 | { | |
6224 | if (flags & PERF_EF_START) | |
6225 | task_clock_event_start(event, flags); | |
b0a873eb | 6226 | |
a4eaf7f1 PZ |
6227 | return 0; |
6228 | } | |
6229 | ||
6230 | static void task_clock_event_del(struct perf_event *event, int flags) | |
6231 | { | |
6232 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
6233 | } |
6234 | ||
6235 | static void task_clock_event_read(struct perf_event *event) | |
6236 | { | |
768a06e2 PZ |
6237 | u64 now = perf_clock(); |
6238 | u64 delta = now - event->ctx->timestamp; | |
6239 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
6240 | |
6241 | task_clock_event_update(event, time); | |
6242 | } | |
6243 | ||
6244 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 6245 | { |
b0a873eb PZ |
6246 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
6247 | return -ENOENT; | |
6248 | ||
6249 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
6250 | return -ENOENT; | |
6251 | ||
2481c5fa SE |
6252 | /* |
6253 | * no branch sampling for software events | |
6254 | */ | |
6255 | if (has_branch_stack(event)) | |
6256 | return -EOPNOTSUPP; | |
6257 | ||
ba3dd36c PZ |
6258 | perf_swevent_init_hrtimer(event); |
6259 | ||
b0a873eb | 6260 | return 0; |
6fb2915d LZ |
6261 | } |
6262 | ||
b0a873eb | 6263 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
6264 | .task_ctx_nr = perf_sw_context, |
6265 | ||
b0a873eb | 6266 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
6267 | .add = task_clock_event_add, |
6268 | .del = task_clock_event_del, | |
6269 | .start = task_clock_event_start, | |
6270 | .stop = task_clock_event_stop, | |
b0a873eb | 6271 | .read = task_clock_event_read, |
35edc2a5 PZ |
6272 | |
6273 | .event_idx = perf_swevent_event_idx, | |
b0a873eb | 6274 | }; |
6fb2915d | 6275 | |
ad5133b7 | 6276 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 6277 | { |
e077df4f | 6278 | } |
6fb2915d | 6279 | |
ad5133b7 | 6280 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 6281 | { |
ad5133b7 | 6282 | return 0; |
6fb2915d LZ |
6283 | } |
6284 | ||
ad5133b7 | 6285 | static void perf_pmu_start_txn(struct pmu *pmu) |
6fb2915d | 6286 | { |
ad5133b7 | 6287 | perf_pmu_disable(pmu); |
6fb2915d LZ |
6288 | } |
6289 | ||
ad5133b7 PZ |
6290 | static int perf_pmu_commit_txn(struct pmu *pmu) |
6291 | { | |
6292 | perf_pmu_enable(pmu); | |
6293 | return 0; | |
6294 | } | |
e077df4f | 6295 | |
ad5133b7 | 6296 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 6297 | { |
ad5133b7 | 6298 | perf_pmu_enable(pmu); |
24f1e32c FW |
6299 | } |
6300 | ||
35edc2a5 PZ |
6301 | static int perf_event_idx_default(struct perf_event *event) |
6302 | { | |
6303 | return event->hw.idx + 1; | |
6304 | } | |
6305 | ||
8dc85d54 PZ |
6306 | /* |
6307 | * Ensures all contexts with the same task_ctx_nr have the same | |
6308 | * pmu_cpu_context too. | |
6309 | */ | |
9e317041 | 6310 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 6311 | { |
8dc85d54 | 6312 | struct pmu *pmu; |
b326e956 | 6313 | |
8dc85d54 PZ |
6314 | if (ctxn < 0) |
6315 | return NULL; | |
24f1e32c | 6316 | |
8dc85d54 PZ |
6317 | list_for_each_entry(pmu, &pmus, entry) { |
6318 | if (pmu->task_ctx_nr == ctxn) | |
6319 | return pmu->pmu_cpu_context; | |
6320 | } | |
24f1e32c | 6321 | |
8dc85d54 | 6322 | return NULL; |
24f1e32c FW |
6323 | } |
6324 | ||
51676957 | 6325 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 6326 | { |
51676957 PZ |
6327 | int cpu; |
6328 | ||
6329 | for_each_possible_cpu(cpu) { | |
6330 | struct perf_cpu_context *cpuctx; | |
6331 | ||
6332 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
6333 | ||
3f1f3320 PZ |
6334 | if (cpuctx->unique_pmu == old_pmu) |
6335 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
6336 | } |
6337 | } | |
6338 | ||
6339 | static void free_pmu_context(struct pmu *pmu) | |
6340 | { | |
6341 | struct pmu *i; | |
f5ffe02e | 6342 | |
8dc85d54 | 6343 | mutex_lock(&pmus_lock); |
0475f9ea | 6344 | /* |
8dc85d54 | 6345 | * Like a real lame refcount. |
0475f9ea | 6346 | */ |
51676957 PZ |
6347 | list_for_each_entry(i, &pmus, entry) { |
6348 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
6349 | update_pmu_context(i, pmu); | |
8dc85d54 | 6350 | goto out; |
51676957 | 6351 | } |
8dc85d54 | 6352 | } |
d6d020e9 | 6353 | |
51676957 | 6354 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
6355 | out: |
6356 | mutex_unlock(&pmus_lock); | |
24f1e32c | 6357 | } |
2e80a82a | 6358 | static struct idr pmu_idr; |
d6d020e9 | 6359 | |
abe43400 PZ |
6360 | static ssize_t |
6361 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
6362 | { | |
6363 | struct pmu *pmu = dev_get_drvdata(dev); | |
6364 | ||
6365 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
6366 | } | |
90826ca7 | 6367 | static DEVICE_ATTR_RO(type); |
abe43400 | 6368 | |
62b85639 SE |
6369 | static ssize_t |
6370 | perf_event_mux_interval_ms_show(struct device *dev, | |
6371 | struct device_attribute *attr, | |
6372 | char *page) | |
6373 | { | |
6374 | struct pmu *pmu = dev_get_drvdata(dev); | |
6375 | ||
6376 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
6377 | } | |
6378 | ||
6379 | static ssize_t | |
6380 | perf_event_mux_interval_ms_store(struct device *dev, | |
6381 | struct device_attribute *attr, | |
6382 | const char *buf, size_t count) | |
6383 | { | |
6384 | struct pmu *pmu = dev_get_drvdata(dev); | |
6385 | int timer, cpu, ret; | |
6386 | ||
6387 | ret = kstrtoint(buf, 0, &timer); | |
6388 | if (ret) | |
6389 | return ret; | |
6390 | ||
6391 | if (timer < 1) | |
6392 | return -EINVAL; | |
6393 | ||
6394 | /* same value, noting to do */ | |
6395 | if (timer == pmu->hrtimer_interval_ms) | |
6396 | return count; | |
6397 | ||
6398 | pmu->hrtimer_interval_ms = timer; | |
6399 | ||
6400 | /* update all cpuctx for this PMU */ | |
6401 | for_each_possible_cpu(cpu) { | |
6402 | struct perf_cpu_context *cpuctx; | |
6403 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
6404 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
6405 | ||
6406 | if (hrtimer_active(&cpuctx->hrtimer)) | |
6407 | hrtimer_forward_now(&cpuctx->hrtimer, cpuctx->hrtimer_interval); | |
6408 | } | |
6409 | ||
6410 | return count; | |
6411 | } | |
90826ca7 | 6412 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 6413 | |
90826ca7 GKH |
6414 | static struct attribute *pmu_dev_attrs[] = { |
6415 | &dev_attr_type.attr, | |
6416 | &dev_attr_perf_event_mux_interval_ms.attr, | |
6417 | NULL, | |
abe43400 | 6418 | }; |
90826ca7 | 6419 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
6420 | |
6421 | static int pmu_bus_running; | |
6422 | static struct bus_type pmu_bus = { | |
6423 | .name = "event_source", | |
90826ca7 | 6424 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
6425 | }; |
6426 | ||
6427 | static void pmu_dev_release(struct device *dev) | |
6428 | { | |
6429 | kfree(dev); | |
6430 | } | |
6431 | ||
6432 | static int pmu_dev_alloc(struct pmu *pmu) | |
6433 | { | |
6434 | int ret = -ENOMEM; | |
6435 | ||
6436 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
6437 | if (!pmu->dev) | |
6438 | goto out; | |
6439 | ||
0c9d42ed | 6440 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
6441 | device_initialize(pmu->dev); |
6442 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
6443 | if (ret) | |
6444 | goto free_dev; | |
6445 | ||
6446 | dev_set_drvdata(pmu->dev, pmu); | |
6447 | pmu->dev->bus = &pmu_bus; | |
6448 | pmu->dev->release = pmu_dev_release; | |
6449 | ret = device_add(pmu->dev); | |
6450 | if (ret) | |
6451 | goto free_dev; | |
6452 | ||
6453 | out: | |
6454 | return ret; | |
6455 | ||
6456 | free_dev: | |
6457 | put_device(pmu->dev); | |
6458 | goto out; | |
6459 | } | |
6460 | ||
547e9fd7 | 6461 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 6462 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 6463 | |
03d8e80b | 6464 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 6465 | { |
108b02cf | 6466 | int cpu, ret; |
24f1e32c | 6467 | |
b0a873eb | 6468 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
6469 | ret = -ENOMEM; |
6470 | pmu->pmu_disable_count = alloc_percpu(int); | |
6471 | if (!pmu->pmu_disable_count) | |
6472 | goto unlock; | |
f29ac756 | 6473 | |
2e80a82a PZ |
6474 | pmu->type = -1; |
6475 | if (!name) | |
6476 | goto skip_type; | |
6477 | pmu->name = name; | |
6478 | ||
6479 | if (type < 0) { | |
0e9c3be2 TH |
6480 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
6481 | if (type < 0) { | |
6482 | ret = type; | |
2e80a82a PZ |
6483 | goto free_pdc; |
6484 | } | |
6485 | } | |
6486 | pmu->type = type; | |
6487 | ||
abe43400 PZ |
6488 | if (pmu_bus_running) { |
6489 | ret = pmu_dev_alloc(pmu); | |
6490 | if (ret) | |
6491 | goto free_idr; | |
6492 | } | |
6493 | ||
2e80a82a | 6494 | skip_type: |
8dc85d54 PZ |
6495 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
6496 | if (pmu->pmu_cpu_context) | |
6497 | goto got_cpu_context; | |
f29ac756 | 6498 | |
c4814202 | 6499 | ret = -ENOMEM; |
108b02cf PZ |
6500 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
6501 | if (!pmu->pmu_cpu_context) | |
abe43400 | 6502 | goto free_dev; |
f344011c | 6503 | |
108b02cf PZ |
6504 | for_each_possible_cpu(cpu) { |
6505 | struct perf_cpu_context *cpuctx; | |
6506 | ||
6507 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 6508 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 6509 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 6510 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
b04243ef | 6511 | cpuctx->ctx.type = cpu_context; |
108b02cf | 6512 | cpuctx->ctx.pmu = pmu; |
9e630205 SE |
6513 | |
6514 | __perf_cpu_hrtimer_init(cpuctx, cpu); | |
6515 | ||
e9d2b064 | 6516 | INIT_LIST_HEAD(&cpuctx->rotation_list); |
3f1f3320 | 6517 | cpuctx->unique_pmu = pmu; |
108b02cf | 6518 | } |
76e1d904 | 6519 | |
8dc85d54 | 6520 | got_cpu_context: |
ad5133b7 PZ |
6521 | if (!pmu->start_txn) { |
6522 | if (pmu->pmu_enable) { | |
6523 | /* | |
6524 | * If we have pmu_enable/pmu_disable calls, install | |
6525 | * transaction stubs that use that to try and batch | |
6526 | * hardware accesses. | |
6527 | */ | |
6528 | pmu->start_txn = perf_pmu_start_txn; | |
6529 | pmu->commit_txn = perf_pmu_commit_txn; | |
6530 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
6531 | } else { | |
6532 | pmu->start_txn = perf_pmu_nop_void; | |
6533 | pmu->commit_txn = perf_pmu_nop_int; | |
6534 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 6535 | } |
5c92d124 | 6536 | } |
15dbf27c | 6537 | |
ad5133b7 PZ |
6538 | if (!pmu->pmu_enable) { |
6539 | pmu->pmu_enable = perf_pmu_nop_void; | |
6540 | pmu->pmu_disable = perf_pmu_nop_void; | |
6541 | } | |
6542 | ||
35edc2a5 PZ |
6543 | if (!pmu->event_idx) |
6544 | pmu->event_idx = perf_event_idx_default; | |
6545 | ||
b0a873eb | 6546 | list_add_rcu(&pmu->entry, &pmus); |
33696fc0 PZ |
6547 | ret = 0; |
6548 | unlock: | |
b0a873eb PZ |
6549 | mutex_unlock(&pmus_lock); |
6550 | ||
33696fc0 | 6551 | return ret; |
108b02cf | 6552 | |
abe43400 PZ |
6553 | free_dev: |
6554 | device_del(pmu->dev); | |
6555 | put_device(pmu->dev); | |
6556 | ||
2e80a82a PZ |
6557 | free_idr: |
6558 | if (pmu->type >= PERF_TYPE_MAX) | |
6559 | idr_remove(&pmu_idr, pmu->type); | |
6560 | ||
108b02cf PZ |
6561 | free_pdc: |
6562 | free_percpu(pmu->pmu_disable_count); | |
6563 | goto unlock; | |
f29ac756 PZ |
6564 | } |
6565 | ||
b0a873eb | 6566 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 6567 | { |
b0a873eb PZ |
6568 | mutex_lock(&pmus_lock); |
6569 | list_del_rcu(&pmu->entry); | |
6570 | mutex_unlock(&pmus_lock); | |
5c92d124 | 6571 | |
0475f9ea | 6572 | /* |
cde8e884 PZ |
6573 | * We dereference the pmu list under both SRCU and regular RCU, so |
6574 | * synchronize against both of those. | |
0475f9ea | 6575 | */ |
b0a873eb | 6576 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 6577 | synchronize_rcu(); |
d6d020e9 | 6578 | |
33696fc0 | 6579 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
6580 | if (pmu->type >= PERF_TYPE_MAX) |
6581 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
6582 | device_del(pmu->dev); |
6583 | put_device(pmu->dev); | |
51676957 | 6584 | free_pmu_context(pmu); |
b0a873eb | 6585 | } |
d6d020e9 | 6586 | |
b0a873eb PZ |
6587 | struct pmu *perf_init_event(struct perf_event *event) |
6588 | { | |
6589 | struct pmu *pmu = NULL; | |
6590 | int idx; | |
940c5b29 | 6591 | int ret; |
b0a873eb PZ |
6592 | |
6593 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
6594 | |
6595 | rcu_read_lock(); | |
6596 | pmu = idr_find(&pmu_idr, event->attr.type); | |
6597 | rcu_read_unlock(); | |
940c5b29 | 6598 | if (pmu) { |
7e5b2a01 | 6599 | event->pmu = pmu; |
940c5b29 LM |
6600 | ret = pmu->event_init(event); |
6601 | if (ret) | |
6602 | pmu = ERR_PTR(ret); | |
2e80a82a | 6603 | goto unlock; |
940c5b29 | 6604 | } |
2e80a82a | 6605 | |
b0a873eb | 6606 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
7e5b2a01 | 6607 | event->pmu = pmu; |
940c5b29 | 6608 | ret = pmu->event_init(event); |
b0a873eb | 6609 | if (!ret) |
e5f4d339 | 6610 | goto unlock; |
76e1d904 | 6611 | |
b0a873eb PZ |
6612 | if (ret != -ENOENT) { |
6613 | pmu = ERR_PTR(ret); | |
e5f4d339 | 6614 | goto unlock; |
f344011c | 6615 | } |
5c92d124 | 6616 | } |
e5f4d339 PZ |
6617 | pmu = ERR_PTR(-ENOENT); |
6618 | unlock: | |
b0a873eb | 6619 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 6620 | |
4aeb0b42 | 6621 | return pmu; |
5c92d124 IM |
6622 | } |
6623 | ||
4beb31f3 FW |
6624 | static void account_event_cpu(struct perf_event *event, int cpu) |
6625 | { | |
6626 | if (event->parent) | |
6627 | return; | |
6628 | ||
6629 | if (has_branch_stack(event)) { | |
6630 | if (!(event->attach_state & PERF_ATTACH_TASK)) | |
6631 | atomic_inc(&per_cpu(perf_branch_stack_events, cpu)); | |
6632 | } | |
6633 | if (is_cgroup_event(event)) | |
6634 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
6635 | } | |
6636 | ||
766d6c07 FW |
6637 | static void account_event(struct perf_event *event) |
6638 | { | |
4beb31f3 FW |
6639 | if (event->parent) |
6640 | return; | |
6641 | ||
766d6c07 FW |
6642 | if (event->attach_state & PERF_ATTACH_TASK) |
6643 | static_key_slow_inc(&perf_sched_events.key); | |
6644 | if (event->attr.mmap || event->attr.mmap_data) | |
6645 | atomic_inc(&nr_mmap_events); | |
6646 | if (event->attr.comm) | |
6647 | atomic_inc(&nr_comm_events); | |
6648 | if (event->attr.task) | |
6649 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
6650 | if (event->attr.freq) { |
6651 | if (atomic_inc_return(&nr_freq_events) == 1) | |
6652 | tick_nohz_full_kick_all(); | |
6653 | } | |
4beb31f3 | 6654 | if (has_branch_stack(event)) |
766d6c07 | 6655 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 | 6656 | if (is_cgroup_event(event)) |
766d6c07 | 6657 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
6658 | |
6659 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
6660 | } |
6661 | ||
0793a61d | 6662 | /* |
cdd6c482 | 6663 | * Allocate and initialize a event structure |
0793a61d | 6664 | */ |
cdd6c482 | 6665 | static struct perf_event * |
c3f00c70 | 6666 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
6667 | struct task_struct *task, |
6668 | struct perf_event *group_leader, | |
6669 | struct perf_event *parent_event, | |
4dc0da86 AK |
6670 | perf_overflow_handler_t overflow_handler, |
6671 | void *context) | |
0793a61d | 6672 | { |
51b0fe39 | 6673 | struct pmu *pmu; |
cdd6c482 IM |
6674 | struct perf_event *event; |
6675 | struct hw_perf_event *hwc; | |
90983b16 | 6676 | long err = -EINVAL; |
0793a61d | 6677 | |
66832eb4 ON |
6678 | if ((unsigned)cpu >= nr_cpu_ids) { |
6679 | if (!task || cpu != -1) | |
6680 | return ERR_PTR(-EINVAL); | |
6681 | } | |
6682 | ||
c3f00c70 | 6683 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 6684 | if (!event) |
d5d2bc0d | 6685 | return ERR_PTR(-ENOMEM); |
0793a61d | 6686 | |
04289bb9 | 6687 | /* |
cdd6c482 | 6688 | * Single events are their own group leaders, with an |
04289bb9 IM |
6689 | * empty sibling list: |
6690 | */ | |
6691 | if (!group_leader) | |
cdd6c482 | 6692 | group_leader = event; |
04289bb9 | 6693 | |
cdd6c482 IM |
6694 | mutex_init(&event->child_mutex); |
6695 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 6696 | |
cdd6c482 IM |
6697 | INIT_LIST_HEAD(&event->group_entry); |
6698 | INIT_LIST_HEAD(&event->event_entry); | |
6699 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 6700 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 6701 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
6702 | INIT_HLIST_NODE(&event->hlist_entry); |
6703 | ||
10c6db11 | 6704 | |
cdd6c482 | 6705 | init_waitqueue_head(&event->waitq); |
e360adbe | 6706 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 6707 | |
cdd6c482 | 6708 | mutex_init(&event->mmap_mutex); |
7b732a75 | 6709 | |
a6fa941d | 6710 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
6711 | event->cpu = cpu; |
6712 | event->attr = *attr; | |
6713 | event->group_leader = group_leader; | |
6714 | event->pmu = NULL; | |
cdd6c482 | 6715 | event->oncpu = -1; |
a96bbc16 | 6716 | |
cdd6c482 | 6717 | event->parent = parent_event; |
b84fbc9f | 6718 | |
17cf22c3 | 6719 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 6720 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 6721 | |
cdd6c482 | 6722 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 6723 | |
d580ff86 PZ |
6724 | if (task) { |
6725 | event->attach_state = PERF_ATTACH_TASK; | |
f22c1bb6 ON |
6726 | |
6727 | if (attr->type == PERF_TYPE_TRACEPOINT) | |
6728 | event->hw.tp_target = task; | |
d580ff86 PZ |
6729 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
6730 | /* | |
6731 | * hw_breakpoint is a bit difficult here.. | |
6732 | */ | |
f22c1bb6 | 6733 | else if (attr->type == PERF_TYPE_BREAKPOINT) |
d580ff86 PZ |
6734 | event->hw.bp_target = task; |
6735 | #endif | |
6736 | } | |
6737 | ||
4dc0da86 | 6738 | if (!overflow_handler && parent_event) { |
b326e956 | 6739 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
6740 | context = parent_event->overflow_handler_context; |
6741 | } | |
66832eb4 | 6742 | |
b326e956 | 6743 | event->overflow_handler = overflow_handler; |
4dc0da86 | 6744 | event->overflow_handler_context = context; |
97eaf530 | 6745 | |
0231bb53 | 6746 | perf_event__state_init(event); |
a86ed508 | 6747 | |
4aeb0b42 | 6748 | pmu = NULL; |
b8e83514 | 6749 | |
cdd6c482 | 6750 | hwc = &event->hw; |
bd2b5b12 | 6751 | hwc->sample_period = attr->sample_period; |
0d48696f | 6752 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 6753 | hwc->sample_period = 1; |
eced1dfc | 6754 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 6755 | |
e7850595 | 6756 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 6757 | |
2023b359 | 6758 | /* |
cdd6c482 | 6759 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 6760 | */ |
3dab77fb | 6761 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 6762 | goto err_ns; |
2023b359 | 6763 | |
b0a873eb | 6764 | pmu = perf_init_event(event); |
4aeb0b42 | 6765 | if (!pmu) |
90983b16 FW |
6766 | goto err_ns; |
6767 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 6768 | err = PTR_ERR(pmu); |
90983b16 | 6769 | goto err_ns; |
621a01ea | 6770 | } |
d5d2bc0d | 6771 | |
cdd6c482 | 6772 | if (!event->parent) { |
927c7a9e FW |
6773 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
6774 | err = get_callchain_buffers(); | |
90983b16 FW |
6775 | if (err) |
6776 | goto err_pmu; | |
d010b332 | 6777 | } |
f344011c | 6778 | } |
9ee318a7 | 6779 | |
cdd6c482 | 6780 | return event; |
90983b16 FW |
6781 | |
6782 | err_pmu: | |
6783 | if (event->destroy) | |
6784 | event->destroy(event); | |
6785 | err_ns: | |
6786 | if (event->ns) | |
6787 | put_pid_ns(event->ns); | |
6788 | kfree(event); | |
6789 | ||
6790 | return ERR_PTR(err); | |
0793a61d TG |
6791 | } |
6792 | ||
cdd6c482 IM |
6793 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
6794 | struct perf_event_attr *attr) | |
974802ea | 6795 | { |
974802ea | 6796 | u32 size; |
cdf8073d | 6797 | int ret; |
974802ea PZ |
6798 | |
6799 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
6800 | return -EFAULT; | |
6801 | ||
6802 | /* | |
6803 | * zero the full structure, so that a short copy will be nice. | |
6804 | */ | |
6805 | memset(attr, 0, sizeof(*attr)); | |
6806 | ||
6807 | ret = get_user(size, &uattr->size); | |
6808 | if (ret) | |
6809 | return ret; | |
6810 | ||
6811 | if (size > PAGE_SIZE) /* silly large */ | |
6812 | goto err_size; | |
6813 | ||
6814 | if (!size) /* abi compat */ | |
6815 | size = PERF_ATTR_SIZE_VER0; | |
6816 | ||
6817 | if (size < PERF_ATTR_SIZE_VER0) | |
6818 | goto err_size; | |
6819 | ||
6820 | /* | |
6821 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
6822 | * ensure all the unknown bits are 0 - i.e. new |
6823 | * user-space does not rely on any kernel feature | |
6824 | * extensions we dont know about yet. | |
974802ea PZ |
6825 | */ |
6826 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
6827 | unsigned char __user *addr; |
6828 | unsigned char __user *end; | |
6829 | unsigned char val; | |
974802ea | 6830 | |
cdf8073d IS |
6831 | addr = (void __user *)uattr + sizeof(*attr); |
6832 | end = (void __user *)uattr + size; | |
974802ea | 6833 | |
cdf8073d | 6834 | for (; addr < end; addr++) { |
974802ea PZ |
6835 | ret = get_user(val, addr); |
6836 | if (ret) | |
6837 | return ret; | |
6838 | if (val) | |
6839 | goto err_size; | |
6840 | } | |
b3e62e35 | 6841 | size = sizeof(*attr); |
974802ea PZ |
6842 | } |
6843 | ||
6844 | ret = copy_from_user(attr, uattr, size); | |
6845 | if (ret) | |
6846 | return -EFAULT; | |
6847 | ||
3090ffb5 SE |
6848 | /* disabled for now */ |
6849 | if (attr->mmap2) | |
6850 | return -EINVAL; | |
6851 | ||
cd757645 | 6852 | if (attr->__reserved_1) |
974802ea PZ |
6853 | return -EINVAL; |
6854 | ||
6855 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
6856 | return -EINVAL; | |
6857 | ||
6858 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
6859 | return -EINVAL; | |
6860 | ||
bce38cd5 SE |
6861 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
6862 | u64 mask = attr->branch_sample_type; | |
6863 | ||
6864 | /* only using defined bits */ | |
6865 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
6866 | return -EINVAL; | |
6867 | ||
6868 | /* at least one branch bit must be set */ | |
6869 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
6870 | return -EINVAL; | |
6871 | ||
bce38cd5 SE |
6872 | /* propagate priv level, when not set for branch */ |
6873 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
6874 | ||
6875 | /* exclude_kernel checked on syscall entry */ | |
6876 | if (!attr->exclude_kernel) | |
6877 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
6878 | ||
6879 | if (!attr->exclude_user) | |
6880 | mask |= PERF_SAMPLE_BRANCH_USER; | |
6881 | ||
6882 | if (!attr->exclude_hv) | |
6883 | mask |= PERF_SAMPLE_BRANCH_HV; | |
6884 | /* | |
6885 | * adjust user setting (for HW filter setup) | |
6886 | */ | |
6887 | attr->branch_sample_type = mask; | |
6888 | } | |
e712209a SE |
6889 | /* privileged levels capture (kernel, hv): check permissions */ |
6890 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
6891 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
6892 | return -EACCES; | |
bce38cd5 | 6893 | } |
4018994f | 6894 | |
c5ebcedb | 6895 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 6896 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
6897 | if (ret) |
6898 | return ret; | |
6899 | } | |
6900 | ||
6901 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
6902 | if (!arch_perf_have_user_stack_dump()) | |
6903 | return -ENOSYS; | |
6904 | ||
6905 | /* | |
6906 | * We have __u32 type for the size, but so far | |
6907 | * we can only use __u16 as maximum due to the | |
6908 | * __u16 sample size limit. | |
6909 | */ | |
6910 | if (attr->sample_stack_user >= USHRT_MAX) | |
6911 | ret = -EINVAL; | |
6912 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
6913 | ret = -EINVAL; | |
6914 | } | |
4018994f | 6915 | |
974802ea PZ |
6916 | out: |
6917 | return ret; | |
6918 | ||
6919 | err_size: | |
6920 | put_user(sizeof(*attr), &uattr->size); | |
6921 | ret = -E2BIG; | |
6922 | goto out; | |
6923 | } | |
6924 | ||
ac9721f3 PZ |
6925 | static int |
6926 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 6927 | { |
76369139 | 6928 | struct ring_buffer *rb = NULL, *old_rb = NULL; |
a4be7c27 PZ |
6929 | int ret = -EINVAL; |
6930 | ||
ac9721f3 | 6931 | if (!output_event) |
a4be7c27 PZ |
6932 | goto set; |
6933 | ||
ac9721f3 PZ |
6934 | /* don't allow circular references */ |
6935 | if (event == output_event) | |
a4be7c27 PZ |
6936 | goto out; |
6937 | ||
0f139300 PZ |
6938 | /* |
6939 | * Don't allow cross-cpu buffers | |
6940 | */ | |
6941 | if (output_event->cpu != event->cpu) | |
6942 | goto out; | |
6943 | ||
6944 | /* | |
76369139 | 6945 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
6946 | */ |
6947 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
6948 | goto out; | |
6949 | ||
a4be7c27 | 6950 | set: |
cdd6c482 | 6951 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
6952 | /* Can't redirect output if we've got an active mmap() */ |
6953 | if (atomic_read(&event->mmap_count)) | |
6954 | goto unlock; | |
a4be7c27 | 6955 | |
9bb5d40c PZ |
6956 | old_rb = event->rb; |
6957 | ||
ac9721f3 | 6958 | if (output_event) { |
76369139 FW |
6959 | /* get the rb we want to redirect to */ |
6960 | rb = ring_buffer_get(output_event); | |
6961 | if (!rb) | |
ac9721f3 | 6962 | goto unlock; |
a4be7c27 PZ |
6963 | } |
6964 | ||
10c6db11 PZ |
6965 | if (old_rb) |
6966 | ring_buffer_detach(event, old_rb); | |
9bb5d40c PZ |
6967 | |
6968 | if (rb) | |
6969 | ring_buffer_attach(event, rb); | |
6970 | ||
6971 | rcu_assign_pointer(event->rb, rb); | |
6972 | ||
6973 | if (old_rb) { | |
6974 | ring_buffer_put(old_rb); | |
6975 | /* | |
6976 | * Since we detached before setting the new rb, so that we | |
6977 | * could attach the new rb, we could have missed a wakeup. | |
6978 | * Provide it now. | |
6979 | */ | |
6980 | wake_up_all(&event->waitq); | |
6981 | } | |
6982 | ||
a4be7c27 | 6983 | ret = 0; |
ac9721f3 PZ |
6984 | unlock: |
6985 | mutex_unlock(&event->mmap_mutex); | |
6986 | ||
a4be7c27 | 6987 | out: |
a4be7c27 PZ |
6988 | return ret; |
6989 | } | |
6990 | ||
0793a61d | 6991 | /** |
cdd6c482 | 6992 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 6993 | * |
cdd6c482 | 6994 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 6995 | * @pid: target pid |
9f66a381 | 6996 | * @cpu: target cpu |
cdd6c482 | 6997 | * @group_fd: group leader event fd |
0793a61d | 6998 | */ |
cdd6c482 IM |
6999 | SYSCALL_DEFINE5(perf_event_open, |
7000 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 7001 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 7002 | { |
b04243ef PZ |
7003 | struct perf_event *group_leader = NULL, *output_event = NULL; |
7004 | struct perf_event *event, *sibling; | |
cdd6c482 IM |
7005 | struct perf_event_attr attr; |
7006 | struct perf_event_context *ctx; | |
7007 | struct file *event_file = NULL; | |
2903ff01 | 7008 | struct fd group = {NULL, 0}; |
38a81da2 | 7009 | struct task_struct *task = NULL; |
89a1e187 | 7010 | struct pmu *pmu; |
ea635c64 | 7011 | int event_fd; |
b04243ef | 7012 | int move_group = 0; |
dc86cabe | 7013 | int err; |
a21b0b35 | 7014 | int f_flags = O_RDWR; |
0793a61d | 7015 | |
2743a5b0 | 7016 | /* for future expandability... */ |
e5d1367f | 7017 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
7018 | return -EINVAL; |
7019 | ||
dc86cabe IM |
7020 | err = perf_copy_attr(attr_uptr, &attr); |
7021 | if (err) | |
7022 | return err; | |
eab656ae | 7023 | |
0764771d PZ |
7024 | if (!attr.exclude_kernel) { |
7025 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
7026 | return -EACCES; | |
7027 | } | |
7028 | ||
df58ab24 | 7029 | if (attr.freq) { |
cdd6c482 | 7030 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 PZ |
7031 | return -EINVAL; |
7032 | } | |
7033 | ||
e5d1367f SE |
7034 | /* |
7035 | * In cgroup mode, the pid argument is used to pass the fd | |
7036 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
7037 | * designates the cpu on which to monitor threads from that | |
7038 | * cgroup. | |
7039 | */ | |
7040 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
7041 | return -EINVAL; | |
7042 | ||
a21b0b35 YD |
7043 | if (flags & PERF_FLAG_FD_CLOEXEC) |
7044 | f_flags |= O_CLOEXEC; | |
7045 | ||
7046 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
7047 | if (event_fd < 0) |
7048 | return event_fd; | |
7049 | ||
ac9721f3 | 7050 | if (group_fd != -1) { |
2903ff01 AV |
7051 | err = perf_fget_light(group_fd, &group); |
7052 | if (err) | |
d14b12d7 | 7053 | goto err_fd; |
2903ff01 | 7054 | group_leader = group.file->private_data; |
ac9721f3 PZ |
7055 | if (flags & PERF_FLAG_FD_OUTPUT) |
7056 | output_event = group_leader; | |
7057 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
7058 | group_leader = NULL; | |
7059 | } | |
7060 | ||
e5d1367f | 7061 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
7062 | task = find_lively_task_by_vpid(pid); |
7063 | if (IS_ERR(task)) { | |
7064 | err = PTR_ERR(task); | |
7065 | goto err_group_fd; | |
7066 | } | |
7067 | } | |
7068 | ||
fbfc623f YZ |
7069 | get_online_cpus(); |
7070 | ||
4dc0da86 AK |
7071 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
7072 | NULL, NULL); | |
d14b12d7 SE |
7073 | if (IS_ERR(event)) { |
7074 | err = PTR_ERR(event); | |
c6be5a5c | 7075 | goto err_task; |
d14b12d7 SE |
7076 | } |
7077 | ||
e5d1367f SE |
7078 | if (flags & PERF_FLAG_PID_CGROUP) { |
7079 | err = perf_cgroup_connect(pid, event, &attr, group_leader); | |
766d6c07 FW |
7080 | if (err) { |
7081 | __free_event(event); | |
7082 | goto err_task; | |
7083 | } | |
e5d1367f SE |
7084 | } |
7085 | ||
766d6c07 FW |
7086 | account_event(event); |
7087 | ||
89a1e187 PZ |
7088 | /* |
7089 | * Special case software events and allow them to be part of | |
7090 | * any hardware group. | |
7091 | */ | |
7092 | pmu = event->pmu; | |
b04243ef PZ |
7093 | |
7094 | if (group_leader && | |
7095 | (is_software_event(event) != is_software_event(group_leader))) { | |
7096 | if (is_software_event(event)) { | |
7097 | /* | |
7098 | * If event and group_leader are not both a software | |
7099 | * event, and event is, then group leader is not. | |
7100 | * | |
7101 | * Allow the addition of software events to !software | |
7102 | * groups, this is safe because software events never | |
7103 | * fail to schedule. | |
7104 | */ | |
7105 | pmu = group_leader->pmu; | |
7106 | } else if (is_software_event(group_leader) && | |
7107 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
7108 | /* | |
7109 | * In case the group is a pure software group, and we | |
7110 | * try to add a hardware event, move the whole group to | |
7111 | * the hardware context. | |
7112 | */ | |
7113 | move_group = 1; | |
7114 | } | |
7115 | } | |
89a1e187 PZ |
7116 | |
7117 | /* | |
7118 | * Get the target context (task or percpu): | |
7119 | */ | |
e2d37cd2 | 7120 | ctx = find_get_context(pmu, task, event->cpu); |
89a1e187 PZ |
7121 | if (IS_ERR(ctx)) { |
7122 | err = PTR_ERR(ctx); | |
c6be5a5c | 7123 | goto err_alloc; |
89a1e187 PZ |
7124 | } |
7125 | ||
fd1edb3a PZ |
7126 | if (task) { |
7127 | put_task_struct(task); | |
7128 | task = NULL; | |
7129 | } | |
7130 | ||
ccff286d | 7131 | /* |
cdd6c482 | 7132 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 7133 | */ |
ac9721f3 | 7134 | if (group_leader) { |
dc86cabe | 7135 | err = -EINVAL; |
04289bb9 | 7136 | |
04289bb9 | 7137 | /* |
ccff286d IM |
7138 | * Do not allow a recursive hierarchy (this new sibling |
7139 | * becoming part of another group-sibling): | |
7140 | */ | |
7141 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 7142 | goto err_context; |
ccff286d IM |
7143 | /* |
7144 | * Do not allow to attach to a group in a different | |
7145 | * task or CPU context: | |
04289bb9 | 7146 | */ |
b04243ef PZ |
7147 | if (move_group) { |
7148 | if (group_leader->ctx->type != ctx->type) | |
7149 | goto err_context; | |
7150 | } else { | |
7151 | if (group_leader->ctx != ctx) | |
7152 | goto err_context; | |
7153 | } | |
7154 | ||
3b6f9e5c PM |
7155 | /* |
7156 | * Only a group leader can be exclusive or pinned | |
7157 | */ | |
0d48696f | 7158 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 7159 | goto err_context; |
ac9721f3 PZ |
7160 | } |
7161 | ||
7162 | if (output_event) { | |
7163 | err = perf_event_set_output(event, output_event); | |
7164 | if (err) | |
c3f00c70 | 7165 | goto err_context; |
ac9721f3 | 7166 | } |
0793a61d | 7167 | |
a21b0b35 YD |
7168 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
7169 | f_flags); | |
ea635c64 AV |
7170 | if (IS_ERR(event_file)) { |
7171 | err = PTR_ERR(event_file); | |
c3f00c70 | 7172 | goto err_context; |
ea635c64 | 7173 | } |
9b51f66d | 7174 | |
b04243ef PZ |
7175 | if (move_group) { |
7176 | struct perf_event_context *gctx = group_leader->ctx; | |
7177 | ||
7178 | mutex_lock(&gctx->mutex); | |
46ce0fe9 | 7179 | perf_remove_from_context(group_leader, false); |
0231bb53 JO |
7180 | |
7181 | /* | |
7182 | * Removing from the context ends up with disabled | |
7183 | * event. What we want here is event in the initial | |
7184 | * startup state, ready to be add into new context. | |
7185 | */ | |
7186 | perf_event__state_init(group_leader); | |
b04243ef PZ |
7187 | list_for_each_entry(sibling, &group_leader->sibling_list, |
7188 | group_entry) { | |
46ce0fe9 | 7189 | perf_remove_from_context(sibling, false); |
0231bb53 | 7190 | perf_event__state_init(sibling); |
b04243ef PZ |
7191 | put_ctx(gctx); |
7192 | } | |
7193 | mutex_unlock(&gctx->mutex); | |
7194 | put_ctx(gctx); | |
ea635c64 | 7195 | } |
9b51f66d | 7196 | |
ad3a37de | 7197 | WARN_ON_ONCE(ctx->parent_ctx); |
d859e29f | 7198 | mutex_lock(&ctx->mutex); |
b04243ef PZ |
7199 | |
7200 | if (move_group) { | |
0cda4c02 | 7201 | synchronize_rcu(); |
e2d37cd2 | 7202 | perf_install_in_context(ctx, group_leader, event->cpu); |
b04243ef PZ |
7203 | get_ctx(ctx); |
7204 | list_for_each_entry(sibling, &group_leader->sibling_list, | |
7205 | group_entry) { | |
e2d37cd2 | 7206 | perf_install_in_context(ctx, sibling, event->cpu); |
b04243ef PZ |
7207 | get_ctx(ctx); |
7208 | } | |
7209 | } | |
7210 | ||
e2d37cd2 | 7211 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 7212 | perf_unpin_context(ctx); |
d859e29f | 7213 | mutex_unlock(&ctx->mutex); |
9b51f66d | 7214 | |
fbfc623f YZ |
7215 | put_online_cpus(); |
7216 | ||
cdd6c482 | 7217 | event->owner = current; |
8882135b | 7218 | |
cdd6c482 IM |
7219 | mutex_lock(¤t->perf_event_mutex); |
7220 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
7221 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 7222 | |
c320c7b7 ACM |
7223 | /* |
7224 | * Precalculate sample_data sizes | |
7225 | */ | |
7226 | perf_event__header_size(event); | |
6844c09d | 7227 | perf_event__id_header_size(event); |
c320c7b7 | 7228 | |
8a49542c PZ |
7229 | /* |
7230 | * Drop the reference on the group_event after placing the | |
7231 | * new event on the sibling_list. This ensures destruction | |
7232 | * of the group leader will find the pointer to itself in | |
7233 | * perf_group_detach(). | |
7234 | */ | |
2903ff01 | 7235 | fdput(group); |
ea635c64 AV |
7236 | fd_install(event_fd, event_file); |
7237 | return event_fd; | |
0793a61d | 7238 | |
c3f00c70 | 7239 | err_context: |
fe4b04fa | 7240 | perf_unpin_context(ctx); |
ea635c64 | 7241 | put_ctx(ctx); |
c6be5a5c | 7242 | err_alloc: |
ea635c64 | 7243 | free_event(event); |
e7d0bc04 | 7244 | err_task: |
fbfc623f | 7245 | put_online_cpus(); |
e7d0bc04 PZ |
7246 | if (task) |
7247 | put_task_struct(task); | |
89a1e187 | 7248 | err_group_fd: |
2903ff01 | 7249 | fdput(group); |
ea635c64 AV |
7250 | err_fd: |
7251 | put_unused_fd(event_fd); | |
dc86cabe | 7252 | return err; |
0793a61d TG |
7253 | } |
7254 | ||
fb0459d7 AV |
7255 | /** |
7256 | * perf_event_create_kernel_counter | |
7257 | * | |
7258 | * @attr: attributes of the counter to create | |
7259 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 7260 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
7261 | */ |
7262 | struct perf_event * | |
7263 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 7264 | struct task_struct *task, |
4dc0da86 AK |
7265 | perf_overflow_handler_t overflow_handler, |
7266 | void *context) | |
fb0459d7 | 7267 | { |
fb0459d7 | 7268 | struct perf_event_context *ctx; |
c3f00c70 | 7269 | struct perf_event *event; |
fb0459d7 | 7270 | int err; |
d859e29f | 7271 | |
fb0459d7 AV |
7272 | /* |
7273 | * Get the target context (task or percpu): | |
7274 | */ | |
d859e29f | 7275 | |
4dc0da86 AK |
7276 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
7277 | overflow_handler, context); | |
c3f00c70 PZ |
7278 | if (IS_ERR(event)) { |
7279 | err = PTR_ERR(event); | |
7280 | goto err; | |
7281 | } | |
d859e29f | 7282 | |
766d6c07 FW |
7283 | account_event(event); |
7284 | ||
38a81da2 | 7285 | ctx = find_get_context(event->pmu, task, cpu); |
c6567f64 FW |
7286 | if (IS_ERR(ctx)) { |
7287 | err = PTR_ERR(ctx); | |
c3f00c70 | 7288 | goto err_free; |
d859e29f | 7289 | } |
fb0459d7 | 7290 | |
fb0459d7 AV |
7291 | WARN_ON_ONCE(ctx->parent_ctx); |
7292 | mutex_lock(&ctx->mutex); | |
7293 | perf_install_in_context(ctx, event, cpu); | |
fe4b04fa | 7294 | perf_unpin_context(ctx); |
fb0459d7 AV |
7295 | mutex_unlock(&ctx->mutex); |
7296 | ||
fb0459d7 AV |
7297 | return event; |
7298 | ||
c3f00c70 PZ |
7299 | err_free: |
7300 | free_event(event); | |
7301 | err: | |
c6567f64 | 7302 | return ERR_PTR(err); |
9b51f66d | 7303 | } |
fb0459d7 | 7304 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 7305 | |
0cda4c02 YZ |
7306 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
7307 | { | |
7308 | struct perf_event_context *src_ctx; | |
7309 | struct perf_event_context *dst_ctx; | |
7310 | struct perf_event *event, *tmp; | |
7311 | LIST_HEAD(events); | |
7312 | ||
7313 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
7314 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
7315 | ||
7316 | mutex_lock(&src_ctx->mutex); | |
7317 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, | |
7318 | event_entry) { | |
46ce0fe9 | 7319 | perf_remove_from_context(event, false); |
9a545de0 | 7320 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 7321 | put_ctx(src_ctx); |
9886167d | 7322 | list_add(&event->migrate_entry, &events); |
0cda4c02 YZ |
7323 | } |
7324 | mutex_unlock(&src_ctx->mutex); | |
7325 | ||
7326 | synchronize_rcu(); | |
7327 | ||
7328 | mutex_lock(&dst_ctx->mutex); | |
9886167d PZ |
7329 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
7330 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
7331 | if (event->state >= PERF_EVENT_STATE_OFF) |
7332 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 7333 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
7334 | perf_install_in_context(dst_ctx, event, dst_cpu); |
7335 | get_ctx(dst_ctx); | |
7336 | } | |
7337 | mutex_unlock(&dst_ctx->mutex); | |
7338 | } | |
7339 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
7340 | ||
cdd6c482 | 7341 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 7342 | struct task_struct *child) |
d859e29f | 7343 | { |
cdd6c482 | 7344 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 7345 | u64 child_val; |
d859e29f | 7346 | |
cdd6c482 IM |
7347 | if (child_event->attr.inherit_stat) |
7348 | perf_event_read_event(child_event, child); | |
38b200d6 | 7349 | |
b5e58793 | 7350 | child_val = perf_event_count(child_event); |
d859e29f PM |
7351 | |
7352 | /* | |
7353 | * Add back the child's count to the parent's count: | |
7354 | */ | |
a6e6dea6 | 7355 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
7356 | atomic64_add(child_event->total_time_enabled, |
7357 | &parent_event->child_total_time_enabled); | |
7358 | atomic64_add(child_event->total_time_running, | |
7359 | &parent_event->child_total_time_running); | |
d859e29f PM |
7360 | |
7361 | /* | |
cdd6c482 | 7362 | * Remove this event from the parent's list |
d859e29f | 7363 | */ |
cdd6c482 IM |
7364 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
7365 | mutex_lock(&parent_event->child_mutex); | |
7366 | list_del_init(&child_event->child_list); | |
7367 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f PM |
7368 | |
7369 | /* | |
cdd6c482 | 7370 | * Release the parent event, if this was the last |
d859e29f PM |
7371 | * reference to it. |
7372 | */ | |
a6fa941d | 7373 | put_event(parent_event); |
d859e29f PM |
7374 | } |
7375 | ||
9b51f66d | 7376 | static void |
cdd6c482 IM |
7377 | __perf_event_exit_task(struct perf_event *child_event, |
7378 | struct perf_event_context *child_ctx, | |
38b200d6 | 7379 | struct task_struct *child) |
9b51f66d | 7380 | { |
46ce0fe9 | 7381 | perf_remove_from_context(child_event, !!child_event->parent); |
0cc0c027 | 7382 | |
9b51f66d | 7383 | /* |
38b435b1 | 7384 | * It can happen that the parent exits first, and has events |
9b51f66d | 7385 | * that are still around due to the child reference. These |
38b435b1 | 7386 | * events need to be zapped. |
9b51f66d | 7387 | */ |
38b435b1 | 7388 | if (child_event->parent) { |
cdd6c482 IM |
7389 | sync_child_event(child_event, child); |
7390 | free_event(child_event); | |
4bcf349a | 7391 | } |
9b51f66d IM |
7392 | } |
7393 | ||
8dc85d54 | 7394 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 7395 | { |
cdd6c482 IM |
7396 | struct perf_event *child_event, *tmp; |
7397 | struct perf_event_context *child_ctx; | |
a63eaf34 | 7398 | unsigned long flags; |
9b51f66d | 7399 | |
8dc85d54 | 7400 | if (likely(!child->perf_event_ctxp[ctxn])) { |
cdd6c482 | 7401 | perf_event_task(child, NULL, 0); |
9b51f66d | 7402 | return; |
9f498cc5 | 7403 | } |
9b51f66d | 7404 | |
a63eaf34 | 7405 | local_irq_save(flags); |
ad3a37de PM |
7406 | /* |
7407 | * We can't reschedule here because interrupts are disabled, | |
7408 | * and either child is current or it is a task that can't be | |
7409 | * scheduled, so we are now safe from rescheduling changing | |
7410 | * our context. | |
7411 | */ | |
806839b2 | 7412 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
7413 | |
7414 | /* | |
7415 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 7416 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
7417 | * incremented the context's refcount before we do put_ctx below. |
7418 | */ | |
e625cce1 | 7419 | raw_spin_lock(&child_ctx->lock); |
04dc2dbb | 7420 | task_ctx_sched_out(child_ctx); |
8dc85d54 | 7421 | child->perf_event_ctxp[ctxn] = NULL; |
71a851b4 PZ |
7422 | /* |
7423 | * If this context is a clone; unclone it so it can't get | |
7424 | * swapped to another process while we're removing all | |
cdd6c482 | 7425 | * the events from it. |
71a851b4 PZ |
7426 | */ |
7427 | unclone_ctx(child_ctx); | |
5e942bb3 | 7428 | update_context_time(child_ctx); |
e625cce1 | 7429 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
9f498cc5 PZ |
7430 | |
7431 | /* | |
cdd6c482 IM |
7432 | * Report the task dead after unscheduling the events so that we |
7433 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
7434 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 7435 | */ |
cdd6c482 | 7436 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 7437 | |
66fff224 PZ |
7438 | /* |
7439 | * We can recurse on the same lock type through: | |
7440 | * | |
cdd6c482 IM |
7441 | * __perf_event_exit_task() |
7442 | * sync_child_event() | |
a6fa941d AV |
7443 | * put_event() |
7444 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
7445 | * |
7446 | * But since its the parent context it won't be the same instance. | |
7447 | */ | |
a0507c84 | 7448 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 7449 | |
8bc20959 | 7450 | again: |
889ff015 FW |
7451 | list_for_each_entry_safe(child_event, tmp, &child_ctx->pinned_groups, |
7452 | group_entry) | |
7453 | __perf_event_exit_task(child_event, child_ctx, child); | |
7454 | ||
7455 | list_for_each_entry_safe(child_event, tmp, &child_ctx->flexible_groups, | |
65abc865 | 7456 | group_entry) |
cdd6c482 | 7457 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 PZ |
7458 | |
7459 | /* | |
cdd6c482 | 7460 | * If the last event was a group event, it will have appended all |
8bc20959 PZ |
7461 | * its siblings to the list, but we obtained 'tmp' before that which |
7462 | * will still point to the list head terminating the iteration. | |
7463 | */ | |
889ff015 FW |
7464 | if (!list_empty(&child_ctx->pinned_groups) || |
7465 | !list_empty(&child_ctx->flexible_groups)) | |
8bc20959 | 7466 | goto again; |
a63eaf34 PM |
7467 | |
7468 | mutex_unlock(&child_ctx->mutex); | |
7469 | ||
7470 | put_ctx(child_ctx); | |
9b51f66d IM |
7471 | } |
7472 | ||
8dc85d54 PZ |
7473 | /* |
7474 | * When a child task exits, feed back event values to parent events. | |
7475 | */ | |
7476 | void perf_event_exit_task(struct task_struct *child) | |
7477 | { | |
8882135b | 7478 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
7479 | int ctxn; |
7480 | ||
8882135b PZ |
7481 | mutex_lock(&child->perf_event_mutex); |
7482 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
7483 | owner_entry) { | |
7484 | list_del_init(&event->owner_entry); | |
7485 | ||
7486 | /* | |
7487 | * Ensure the list deletion is visible before we clear | |
7488 | * the owner, closes a race against perf_release() where | |
7489 | * we need to serialize on the owner->perf_event_mutex. | |
7490 | */ | |
7491 | smp_wmb(); | |
7492 | event->owner = NULL; | |
7493 | } | |
7494 | mutex_unlock(&child->perf_event_mutex); | |
7495 | ||
8dc85d54 PZ |
7496 | for_each_task_context_nr(ctxn) |
7497 | perf_event_exit_task_context(child, ctxn); | |
7498 | } | |
7499 | ||
889ff015 FW |
7500 | static void perf_free_event(struct perf_event *event, |
7501 | struct perf_event_context *ctx) | |
7502 | { | |
7503 | struct perf_event *parent = event->parent; | |
7504 | ||
7505 | if (WARN_ON_ONCE(!parent)) | |
7506 | return; | |
7507 | ||
7508 | mutex_lock(&parent->child_mutex); | |
7509 | list_del_init(&event->child_list); | |
7510 | mutex_unlock(&parent->child_mutex); | |
7511 | ||
a6fa941d | 7512 | put_event(parent); |
889ff015 | 7513 | |
8a49542c | 7514 | perf_group_detach(event); |
889ff015 FW |
7515 | list_del_event(event, ctx); |
7516 | free_event(event); | |
7517 | } | |
7518 | ||
bbbee908 PZ |
7519 | /* |
7520 | * free an unexposed, unused context as created by inheritance by | |
8dc85d54 | 7521 | * perf_event_init_task below, used by fork() in case of fail. |
bbbee908 | 7522 | */ |
cdd6c482 | 7523 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 7524 | { |
8dc85d54 | 7525 | struct perf_event_context *ctx; |
cdd6c482 | 7526 | struct perf_event *event, *tmp; |
8dc85d54 | 7527 | int ctxn; |
bbbee908 | 7528 | |
8dc85d54 PZ |
7529 | for_each_task_context_nr(ctxn) { |
7530 | ctx = task->perf_event_ctxp[ctxn]; | |
7531 | if (!ctx) | |
7532 | continue; | |
bbbee908 | 7533 | |
8dc85d54 | 7534 | mutex_lock(&ctx->mutex); |
bbbee908 | 7535 | again: |
8dc85d54 PZ |
7536 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
7537 | group_entry) | |
7538 | perf_free_event(event, ctx); | |
bbbee908 | 7539 | |
8dc85d54 PZ |
7540 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
7541 | group_entry) | |
7542 | perf_free_event(event, ctx); | |
bbbee908 | 7543 | |
8dc85d54 PZ |
7544 | if (!list_empty(&ctx->pinned_groups) || |
7545 | !list_empty(&ctx->flexible_groups)) | |
7546 | goto again; | |
bbbee908 | 7547 | |
8dc85d54 | 7548 | mutex_unlock(&ctx->mutex); |
bbbee908 | 7549 | |
8dc85d54 PZ |
7550 | put_ctx(ctx); |
7551 | } | |
889ff015 FW |
7552 | } |
7553 | ||
4e231c79 PZ |
7554 | void perf_event_delayed_put(struct task_struct *task) |
7555 | { | |
7556 | int ctxn; | |
7557 | ||
7558 | for_each_task_context_nr(ctxn) | |
7559 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
7560 | } | |
7561 | ||
97dee4f3 PZ |
7562 | /* |
7563 | * inherit a event from parent task to child task: | |
7564 | */ | |
7565 | static struct perf_event * | |
7566 | inherit_event(struct perf_event *parent_event, | |
7567 | struct task_struct *parent, | |
7568 | struct perf_event_context *parent_ctx, | |
7569 | struct task_struct *child, | |
7570 | struct perf_event *group_leader, | |
7571 | struct perf_event_context *child_ctx) | |
7572 | { | |
7573 | struct perf_event *child_event; | |
cee010ec | 7574 | unsigned long flags; |
97dee4f3 PZ |
7575 | |
7576 | /* | |
7577 | * Instead of creating recursive hierarchies of events, | |
7578 | * we link inherited events back to the original parent, | |
7579 | * which has a filp for sure, which we use as the reference | |
7580 | * count: | |
7581 | */ | |
7582 | if (parent_event->parent) | |
7583 | parent_event = parent_event->parent; | |
7584 | ||
7585 | child_event = perf_event_alloc(&parent_event->attr, | |
7586 | parent_event->cpu, | |
d580ff86 | 7587 | child, |
97dee4f3 | 7588 | group_leader, parent_event, |
4dc0da86 | 7589 | NULL, NULL); |
97dee4f3 PZ |
7590 | if (IS_ERR(child_event)) |
7591 | return child_event; | |
a6fa941d AV |
7592 | |
7593 | if (!atomic_long_inc_not_zero(&parent_event->refcount)) { | |
7594 | free_event(child_event); | |
7595 | return NULL; | |
7596 | } | |
7597 | ||
97dee4f3 PZ |
7598 | get_ctx(child_ctx); |
7599 | ||
7600 | /* | |
7601 | * Make the child state follow the state of the parent event, | |
7602 | * not its attr.disabled bit. We hold the parent's mutex, | |
7603 | * so we won't race with perf_event_{en, dis}able_family. | |
7604 | */ | |
7605 | if (parent_event->state >= PERF_EVENT_STATE_INACTIVE) | |
7606 | child_event->state = PERF_EVENT_STATE_INACTIVE; | |
7607 | else | |
7608 | child_event->state = PERF_EVENT_STATE_OFF; | |
7609 | ||
7610 | if (parent_event->attr.freq) { | |
7611 | u64 sample_period = parent_event->hw.sample_period; | |
7612 | struct hw_perf_event *hwc = &child_event->hw; | |
7613 | ||
7614 | hwc->sample_period = sample_period; | |
7615 | hwc->last_period = sample_period; | |
7616 | ||
7617 | local64_set(&hwc->period_left, sample_period); | |
7618 | } | |
7619 | ||
7620 | child_event->ctx = child_ctx; | |
7621 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
7622 | child_event->overflow_handler_context |
7623 | = parent_event->overflow_handler_context; | |
97dee4f3 | 7624 | |
614b6780 TG |
7625 | /* |
7626 | * Precalculate sample_data sizes | |
7627 | */ | |
7628 | perf_event__header_size(child_event); | |
6844c09d | 7629 | perf_event__id_header_size(child_event); |
614b6780 | 7630 | |
97dee4f3 PZ |
7631 | /* |
7632 | * Link it up in the child's context: | |
7633 | */ | |
cee010ec | 7634 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 7635 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 7636 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 7637 | |
97dee4f3 PZ |
7638 | /* |
7639 | * Link this into the parent event's child list | |
7640 | */ | |
7641 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
7642 | mutex_lock(&parent_event->child_mutex); | |
7643 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
7644 | mutex_unlock(&parent_event->child_mutex); | |
7645 | ||
7646 | return child_event; | |
7647 | } | |
7648 | ||
7649 | static int inherit_group(struct perf_event *parent_event, | |
7650 | struct task_struct *parent, | |
7651 | struct perf_event_context *parent_ctx, | |
7652 | struct task_struct *child, | |
7653 | struct perf_event_context *child_ctx) | |
7654 | { | |
7655 | struct perf_event *leader; | |
7656 | struct perf_event *sub; | |
7657 | struct perf_event *child_ctr; | |
7658 | ||
7659 | leader = inherit_event(parent_event, parent, parent_ctx, | |
7660 | child, NULL, child_ctx); | |
7661 | if (IS_ERR(leader)) | |
7662 | return PTR_ERR(leader); | |
7663 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
7664 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
7665 | child, leader, child_ctx); | |
7666 | if (IS_ERR(child_ctr)) | |
7667 | return PTR_ERR(child_ctr); | |
7668 | } | |
7669 | return 0; | |
889ff015 FW |
7670 | } |
7671 | ||
7672 | static int | |
7673 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
7674 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 7675 | struct task_struct *child, int ctxn, |
889ff015 FW |
7676 | int *inherited_all) |
7677 | { | |
7678 | int ret; | |
8dc85d54 | 7679 | struct perf_event_context *child_ctx; |
889ff015 FW |
7680 | |
7681 | if (!event->attr.inherit) { | |
7682 | *inherited_all = 0; | |
7683 | return 0; | |
bbbee908 PZ |
7684 | } |
7685 | ||
fe4b04fa | 7686 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
7687 | if (!child_ctx) { |
7688 | /* | |
7689 | * This is executed from the parent task context, so | |
7690 | * inherit events that have been marked for cloning. | |
7691 | * First allocate and initialize a context for the | |
7692 | * child. | |
7693 | */ | |
bbbee908 | 7694 | |
734df5ab | 7695 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
7696 | if (!child_ctx) |
7697 | return -ENOMEM; | |
bbbee908 | 7698 | |
8dc85d54 | 7699 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
7700 | } |
7701 | ||
7702 | ret = inherit_group(event, parent, parent_ctx, | |
7703 | child, child_ctx); | |
7704 | ||
7705 | if (ret) | |
7706 | *inherited_all = 0; | |
7707 | ||
7708 | return ret; | |
bbbee908 PZ |
7709 | } |
7710 | ||
9b51f66d | 7711 | /* |
cdd6c482 | 7712 | * Initialize the perf_event context in task_struct |
9b51f66d | 7713 | */ |
8dc85d54 | 7714 | int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 7715 | { |
889ff015 | 7716 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
7717 | struct perf_event_context *cloned_ctx; |
7718 | struct perf_event *event; | |
9b51f66d | 7719 | struct task_struct *parent = current; |
564c2b21 | 7720 | int inherited_all = 1; |
dddd3379 | 7721 | unsigned long flags; |
6ab423e0 | 7722 | int ret = 0; |
9b51f66d | 7723 | |
8dc85d54 | 7724 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
7725 | return 0; |
7726 | ||
ad3a37de | 7727 | /* |
25346b93 PM |
7728 | * If the parent's context is a clone, pin it so it won't get |
7729 | * swapped under us. | |
ad3a37de | 7730 | */ |
8dc85d54 | 7731 | parent_ctx = perf_pin_task_context(parent, ctxn); |
25346b93 | 7732 | |
ad3a37de PM |
7733 | /* |
7734 | * No need to check if parent_ctx != NULL here; since we saw | |
7735 | * it non-NULL earlier, the only reason for it to become NULL | |
7736 | * is if we exit, and since we're currently in the middle of | |
7737 | * a fork we can't be exiting at the same time. | |
7738 | */ | |
ad3a37de | 7739 | |
9b51f66d IM |
7740 | /* |
7741 | * Lock the parent list. No need to lock the child - not PID | |
7742 | * hashed yet and not running, so nobody can access it. | |
7743 | */ | |
d859e29f | 7744 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
7745 | |
7746 | /* | |
7747 | * We dont have to disable NMIs - we are only looking at | |
7748 | * the list, not manipulating it: | |
7749 | */ | |
889ff015 | 7750 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
7751 | ret = inherit_task_group(event, parent, parent_ctx, |
7752 | child, ctxn, &inherited_all); | |
889ff015 FW |
7753 | if (ret) |
7754 | break; | |
7755 | } | |
b93f7978 | 7756 | |
dddd3379 TG |
7757 | /* |
7758 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
7759 | * to allocations, but we need to prevent rotation because | |
7760 | * rotate_ctx() will change the list from interrupt context. | |
7761 | */ | |
7762 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
7763 | parent_ctx->rotate_disable = 1; | |
7764 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
7765 | ||
889ff015 | 7766 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
7767 | ret = inherit_task_group(event, parent, parent_ctx, |
7768 | child, ctxn, &inherited_all); | |
889ff015 | 7769 | if (ret) |
9b51f66d | 7770 | break; |
564c2b21 PM |
7771 | } |
7772 | ||
dddd3379 TG |
7773 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
7774 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 7775 | |
8dc85d54 | 7776 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 7777 | |
05cbaa28 | 7778 | if (child_ctx && inherited_all) { |
564c2b21 PM |
7779 | /* |
7780 | * Mark the child context as a clone of the parent | |
7781 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
7782 | * |
7783 | * Note that if the parent is a clone, the holding of | |
7784 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 7785 | */ |
c5ed5145 | 7786 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
7787 | if (cloned_ctx) { |
7788 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 7789 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
7790 | } else { |
7791 | child_ctx->parent_ctx = parent_ctx; | |
7792 | child_ctx->parent_gen = parent_ctx->generation; | |
7793 | } | |
7794 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
7795 | } |
7796 | ||
c5ed5145 | 7797 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 7798 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 7799 | |
25346b93 | 7800 | perf_unpin_context(parent_ctx); |
fe4b04fa | 7801 | put_ctx(parent_ctx); |
ad3a37de | 7802 | |
6ab423e0 | 7803 | return ret; |
9b51f66d IM |
7804 | } |
7805 | ||
8dc85d54 PZ |
7806 | /* |
7807 | * Initialize the perf_event context in task_struct | |
7808 | */ | |
7809 | int perf_event_init_task(struct task_struct *child) | |
7810 | { | |
7811 | int ctxn, ret; | |
7812 | ||
8550d7cb ON |
7813 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
7814 | mutex_init(&child->perf_event_mutex); | |
7815 | INIT_LIST_HEAD(&child->perf_event_list); | |
7816 | ||
8dc85d54 PZ |
7817 | for_each_task_context_nr(ctxn) { |
7818 | ret = perf_event_init_context(child, ctxn); | |
7819 | if (ret) | |
7820 | return ret; | |
7821 | } | |
7822 | ||
7823 | return 0; | |
7824 | } | |
7825 | ||
220b140b PM |
7826 | static void __init perf_event_init_all_cpus(void) |
7827 | { | |
b28ab83c | 7828 | struct swevent_htable *swhash; |
220b140b | 7829 | int cpu; |
220b140b PM |
7830 | |
7831 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
7832 | swhash = &per_cpu(swevent_htable, cpu); |
7833 | mutex_init(&swhash->hlist_mutex); | |
e9d2b064 | 7834 | INIT_LIST_HEAD(&per_cpu(rotation_list, cpu)); |
220b140b PM |
7835 | } |
7836 | } | |
7837 | ||
0db0628d | 7838 | static void perf_event_init_cpu(int cpu) |
0793a61d | 7839 | { |
108b02cf | 7840 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 7841 | |
b28ab83c | 7842 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 7843 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
7844 | struct swevent_hlist *hlist; |
7845 | ||
b28ab83c PZ |
7846 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
7847 | WARN_ON(!hlist); | |
7848 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 7849 | } |
b28ab83c | 7850 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
7851 | } |
7852 | ||
c277443c | 7853 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC |
e9d2b064 | 7854 | static void perf_pmu_rotate_stop(struct pmu *pmu) |
0793a61d | 7855 | { |
e9d2b064 PZ |
7856 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
7857 | ||
7858 | WARN_ON(!irqs_disabled()); | |
7859 | ||
7860 | list_del_init(&cpuctx->rotation_list); | |
7861 | } | |
7862 | ||
108b02cf | 7863 | static void __perf_event_exit_context(void *__info) |
0793a61d | 7864 | { |
46ce0fe9 | 7865 | struct remove_event re = { .detach_group = false }; |
108b02cf | 7866 | struct perf_event_context *ctx = __info; |
0793a61d | 7867 | |
108b02cf | 7868 | perf_pmu_rotate_stop(ctx->pmu); |
b5ab4cd5 | 7869 | |
e3703f8c | 7870 | rcu_read_lock(); |
46ce0fe9 PZ |
7871 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) |
7872 | __perf_remove_from_context(&re); | |
e3703f8c | 7873 | rcu_read_unlock(); |
0793a61d | 7874 | } |
108b02cf PZ |
7875 | |
7876 | static void perf_event_exit_cpu_context(int cpu) | |
7877 | { | |
7878 | struct perf_event_context *ctx; | |
7879 | struct pmu *pmu; | |
7880 | int idx; | |
7881 | ||
7882 | idx = srcu_read_lock(&pmus_srcu); | |
7883 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 7884 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
7885 | |
7886 | mutex_lock(&ctx->mutex); | |
7887 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
7888 | mutex_unlock(&ctx->mutex); | |
7889 | } | |
7890 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
7891 | } |
7892 | ||
cdd6c482 | 7893 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 7894 | { |
b28ab83c | 7895 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
d859e29f | 7896 | |
e3703f8c PZ |
7897 | perf_event_exit_cpu_context(cpu); |
7898 | ||
b28ab83c PZ |
7899 | mutex_lock(&swhash->hlist_mutex); |
7900 | swevent_hlist_release(swhash); | |
7901 | mutex_unlock(&swhash->hlist_mutex); | |
0793a61d TG |
7902 | } |
7903 | #else | |
cdd6c482 | 7904 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
7905 | #endif |
7906 | ||
c277443c PZ |
7907 | static int |
7908 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
7909 | { | |
7910 | int cpu; | |
7911 | ||
7912 | for_each_online_cpu(cpu) | |
7913 | perf_event_exit_cpu(cpu); | |
7914 | ||
7915 | return NOTIFY_OK; | |
7916 | } | |
7917 | ||
7918 | /* | |
7919 | * Run the perf reboot notifier at the very last possible moment so that | |
7920 | * the generic watchdog code runs as long as possible. | |
7921 | */ | |
7922 | static struct notifier_block perf_reboot_notifier = { | |
7923 | .notifier_call = perf_reboot, | |
7924 | .priority = INT_MIN, | |
7925 | }; | |
7926 | ||
0db0628d | 7927 | static int |
0793a61d TG |
7928 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
7929 | { | |
7930 | unsigned int cpu = (long)hcpu; | |
7931 | ||
4536e4d1 | 7932 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
7933 | |
7934 | case CPU_UP_PREPARE: | |
5e11637e | 7935 | case CPU_DOWN_FAILED: |
cdd6c482 | 7936 | perf_event_init_cpu(cpu); |
0793a61d TG |
7937 | break; |
7938 | ||
5e11637e | 7939 | case CPU_UP_CANCELED: |
0793a61d | 7940 | case CPU_DOWN_PREPARE: |
cdd6c482 | 7941 | perf_event_exit_cpu(cpu); |
0793a61d | 7942 | break; |
0793a61d TG |
7943 | default: |
7944 | break; | |
7945 | } | |
7946 | ||
7947 | return NOTIFY_OK; | |
7948 | } | |
7949 | ||
cdd6c482 | 7950 | void __init perf_event_init(void) |
0793a61d | 7951 | { |
3c502e7a JW |
7952 | int ret; |
7953 | ||
2e80a82a PZ |
7954 | idr_init(&pmu_idr); |
7955 | ||
220b140b | 7956 | perf_event_init_all_cpus(); |
b0a873eb | 7957 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
7958 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
7959 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
7960 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
7961 | perf_tp_register(); |
7962 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 7963 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
7964 | |
7965 | ret = init_hw_breakpoint(); | |
7966 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
7967 | |
7968 | /* do not patch jump label more than once per second */ | |
7969 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
7970 | |
7971 | /* | |
7972 | * Build time assertion that we keep the data_head at the intended | |
7973 | * location. IOW, validation we got the __reserved[] size right. | |
7974 | */ | |
7975 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
7976 | != 1024); | |
0793a61d | 7977 | } |
abe43400 PZ |
7978 | |
7979 | static int __init perf_event_sysfs_init(void) | |
7980 | { | |
7981 | struct pmu *pmu; | |
7982 | int ret; | |
7983 | ||
7984 | mutex_lock(&pmus_lock); | |
7985 | ||
7986 | ret = bus_register(&pmu_bus); | |
7987 | if (ret) | |
7988 | goto unlock; | |
7989 | ||
7990 | list_for_each_entry(pmu, &pmus, entry) { | |
7991 | if (!pmu->name || pmu->type < 0) | |
7992 | continue; | |
7993 | ||
7994 | ret = pmu_dev_alloc(pmu); | |
7995 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
7996 | } | |
7997 | pmu_bus_running = 1; | |
7998 | ret = 0; | |
7999 | ||
8000 | unlock: | |
8001 | mutex_unlock(&pmus_lock); | |
8002 | ||
8003 | return ret; | |
8004 | } | |
8005 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
8006 | |
8007 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
8008 | static struct cgroup_subsys_state * |
8009 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
8010 | { |
8011 | struct perf_cgroup *jc; | |
e5d1367f | 8012 | |
1b15d055 | 8013 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
8014 | if (!jc) |
8015 | return ERR_PTR(-ENOMEM); | |
8016 | ||
e5d1367f SE |
8017 | jc->info = alloc_percpu(struct perf_cgroup_info); |
8018 | if (!jc->info) { | |
8019 | kfree(jc); | |
8020 | return ERR_PTR(-ENOMEM); | |
8021 | } | |
8022 | ||
e5d1367f SE |
8023 | return &jc->css; |
8024 | } | |
8025 | ||
eb95419b | 8026 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 8027 | { |
eb95419b TH |
8028 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
8029 | ||
e5d1367f SE |
8030 | free_percpu(jc->info); |
8031 | kfree(jc); | |
8032 | } | |
8033 | ||
8034 | static int __perf_cgroup_move(void *info) | |
8035 | { | |
8036 | struct task_struct *task = info; | |
8037 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); | |
8038 | return 0; | |
8039 | } | |
8040 | ||
eb95419b TH |
8041 | static void perf_cgroup_attach(struct cgroup_subsys_state *css, |
8042 | struct cgroup_taskset *tset) | |
e5d1367f | 8043 | { |
bb9d97b6 TH |
8044 | struct task_struct *task; |
8045 | ||
924f0d9a | 8046 | cgroup_taskset_for_each(task, tset) |
bb9d97b6 | 8047 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
8048 | } |
8049 | ||
eb95419b TH |
8050 | static void perf_cgroup_exit(struct cgroup_subsys_state *css, |
8051 | struct cgroup_subsys_state *old_css, | |
761b3ef5 | 8052 | struct task_struct *task) |
e5d1367f SE |
8053 | { |
8054 | /* | |
8055 | * cgroup_exit() is called in the copy_process() failure path. | |
8056 | * Ignore this case since the task hasn't ran yet, this avoids | |
8057 | * trying to poke a half freed task state from generic code. | |
8058 | */ | |
8059 | if (!(task->flags & PF_EXITING)) | |
8060 | return; | |
8061 | ||
bb9d97b6 | 8062 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
8063 | } |
8064 | ||
073219e9 | 8065 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
8066 | .css_alloc = perf_cgroup_css_alloc, |
8067 | .css_free = perf_cgroup_css_free, | |
e7e7ee2e | 8068 | .exit = perf_cgroup_exit, |
bb9d97b6 | 8069 | .attach = perf_cgroup_attach, |
e5d1367f SE |
8070 | }; |
8071 | #endif /* CONFIG_CGROUP_PERF */ |