Commit | Line | Data |
---|---|---|
0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
fadfe7be JO |
52 | static struct workqueue_struct *perf_wq; |
53 | ||
272325c4 PZ |
54 | typedef int (*remote_function_f)(void *); |
55 | ||
fe4b04fa | 56 | struct remote_function_call { |
e7e7ee2e | 57 | struct task_struct *p; |
272325c4 | 58 | remote_function_f func; |
e7e7ee2e IM |
59 | void *info; |
60 | int ret; | |
fe4b04fa PZ |
61 | }; |
62 | ||
63 | static void remote_function(void *data) | |
64 | { | |
65 | struct remote_function_call *tfc = data; | |
66 | struct task_struct *p = tfc->p; | |
67 | ||
68 | if (p) { | |
69 | tfc->ret = -EAGAIN; | |
70 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
71 | return; | |
72 | } | |
73 | ||
74 | tfc->ret = tfc->func(tfc->info); | |
75 | } | |
76 | ||
77 | /** | |
78 | * task_function_call - call a function on the cpu on which a task runs | |
79 | * @p: the task to evaluate | |
80 | * @func: the function to be called | |
81 | * @info: the function call argument | |
82 | * | |
83 | * Calls the function @func when the task is currently running. This might | |
84 | * be on the current CPU, which just calls the function directly | |
85 | * | |
86 | * returns: @func return value, or | |
87 | * -ESRCH - when the process isn't running | |
88 | * -EAGAIN - when the process moved away | |
89 | */ | |
90 | static int | |
272325c4 | 91 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
92 | { |
93 | struct remote_function_call data = { | |
e7e7ee2e IM |
94 | .p = p, |
95 | .func = func, | |
96 | .info = info, | |
97 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
98 | }; |
99 | ||
100 | if (task_curr(p)) | |
101 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
102 | ||
103 | return data.ret; | |
104 | } | |
105 | ||
106 | /** | |
107 | * cpu_function_call - call a function on the cpu | |
108 | * @func: the function to be called | |
109 | * @info: the function call argument | |
110 | * | |
111 | * Calls the function @func on the remote cpu. | |
112 | * | |
113 | * returns: @func return value or -ENXIO when the cpu is offline | |
114 | */ | |
272325c4 | 115 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
116 | { |
117 | struct remote_function_call data = { | |
e7e7ee2e IM |
118 | .p = NULL, |
119 | .func = func, | |
120 | .info = info, | |
121 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
122 | }; |
123 | ||
124 | smp_call_function_single(cpu, remote_function, &data, 1); | |
125 | ||
126 | return data.ret; | |
127 | } | |
128 | ||
fae3fde6 PZ |
129 | static inline struct perf_cpu_context * |
130 | __get_cpu_context(struct perf_event_context *ctx) | |
131 | { | |
132 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
133 | } | |
134 | ||
135 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
136 | struct perf_event_context *ctx) | |
137 | { | |
138 | raw_spin_lock(&cpuctx->ctx.lock); | |
139 | if (ctx) | |
140 | raw_spin_lock(&ctx->lock); | |
141 | } | |
142 | ||
143 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
144 | struct perf_event_context *ctx) | |
145 | { | |
146 | if (ctx) | |
147 | raw_spin_unlock(&ctx->lock); | |
148 | raw_spin_unlock(&cpuctx->ctx.lock); | |
149 | } | |
150 | ||
39a43640 PZ |
151 | /* |
152 | * On task ctx scheduling... | |
153 | * | |
154 | * When !ctx->nr_events a task context will not be scheduled. This means | |
155 | * we can disable the scheduler hooks (for performance) without leaving | |
156 | * pending task ctx state. | |
157 | * | |
158 | * This however results in two special cases: | |
159 | * | |
160 | * - removing the last event from a task ctx; this is relatively straight | |
161 | * forward and is done in __perf_remove_from_context. | |
162 | * | |
163 | * - adding the first event to a task ctx; this is tricky because we cannot | |
164 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
165 | * See perf_install_in_context(). | |
166 | * | |
167 | * This is because we need a ctx->lock serialized variable (ctx->is_active) | |
168 | * to reliably determine if a particular task/context is scheduled in. The | |
169 | * task_curr() use in task_function_call() is racy in that a remote context | |
170 | * switch is not a single atomic operation. | |
171 | * | |
172 | * As is, the situation is 'safe' because we set rq->curr before we do the | |
173 | * actual context switch. This means that task_curr() will fail early, but | |
174 | * we'll continue spinning on ctx->is_active until we've passed | |
175 | * perf_event_task_sched_out(). | |
176 | * | |
177 | * Without this ctx->lock serialized variable we could have race where we find | |
178 | * the task (and hence the context) would not be active while in fact they are. | |
179 | * | |
180 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. | |
181 | */ | |
182 | ||
fae3fde6 PZ |
183 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
184 | struct perf_event_context *, void *); | |
185 | ||
186 | struct event_function_struct { | |
187 | struct perf_event *event; | |
188 | event_f func; | |
189 | void *data; | |
190 | }; | |
191 | ||
192 | static int event_function(void *info) | |
193 | { | |
194 | struct event_function_struct *efs = info; | |
195 | struct perf_event *event = efs->event; | |
196 | struct perf_event_context *ctx = event->ctx; | |
197 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
198 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
199 | ||
200 | WARN_ON_ONCE(!irqs_disabled()); | |
201 | ||
202 | /* | |
203 | * Since we do the IPI call without holding ctx->lock things can have | |
204 | * changed, double check we hit the task we set out to hit. | |
205 | * | |
206 | * If ctx->task == current, we know things must remain valid because | |
207 | * we have IRQs disabled so we cannot schedule. | |
208 | */ | |
209 | if (ctx->task) { | |
210 | if (ctx->task != current) | |
211 | return -EAGAIN; | |
212 | ||
213 | WARN_ON_ONCE(task_ctx != ctx); | |
214 | } else { | |
215 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
216 | } | |
217 | ||
218 | perf_ctx_lock(cpuctx, task_ctx); | |
219 | /* | |
220 | * Now that we hold locks, double check state. Paranoia pays. | |
221 | */ | |
222 | if (task_ctx) { | |
223 | WARN_ON_ONCE(task_ctx->task != current); | |
224 | /* | |
225 | * We only use event_function_call() on established contexts, | |
226 | * and event_function() is only ever called when active (or | |
227 | * rather, we'll have bailed in task_function_call() or the | |
228 | * above ctx->task != current test), therefore we must have | |
229 | * ctx->is_active here. | |
230 | */ | |
231 | WARN_ON_ONCE(!ctx->is_active); | |
232 | /* | |
233 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
234 | * match. | |
235 | */ | |
236 | WARN_ON_ONCE(cpuctx->task_ctx != task_ctx); | |
237 | } | |
238 | efs->func(event, cpuctx, ctx, efs->data); | |
239 | perf_ctx_unlock(cpuctx, task_ctx); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
245 | { | |
246 | struct event_function_struct efs = { | |
247 | .event = event, | |
248 | .func = func, | |
249 | .data = data, | |
250 | }; | |
251 | ||
252 | int ret = event_function(&efs); | |
253 | WARN_ON_ONCE(ret); | |
254 | } | |
255 | ||
256 | static void event_function_call(struct perf_event *event, event_f func, void *data) | |
0017960f PZ |
257 | { |
258 | struct perf_event_context *ctx = event->ctx; | |
259 | struct task_struct *task = ctx->task; | |
fae3fde6 PZ |
260 | struct event_function_struct efs = { |
261 | .event = event, | |
262 | .func = func, | |
263 | .data = data, | |
264 | }; | |
0017960f PZ |
265 | |
266 | if (!task) { | |
fae3fde6 | 267 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
268 | return; |
269 | } | |
270 | ||
271 | again: | |
fae3fde6 | 272 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
273 | return; |
274 | ||
275 | raw_spin_lock_irq(&ctx->lock); | |
276 | if (ctx->is_active) { | |
277 | /* | |
278 | * Reload the task pointer, it might have been changed by | |
279 | * a concurrent perf_event_context_sched_out(). | |
280 | */ | |
281 | task = ctx->task; | |
282 | raw_spin_unlock_irq(&ctx->lock); | |
283 | goto again; | |
284 | } | |
fae3fde6 | 285 | func(event, NULL, ctx, data); |
0017960f PZ |
286 | raw_spin_unlock_irq(&ctx->lock); |
287 | } | |
288 | ||
f8697762 JO |
289 | #define EVENT_OWNER_KERNEL ((void *) -1) |
290 | ||
291 | static bool is_kernel_event(struct perf_event *event) | |
292 | { | |
293 | return event->owner == EVENT_OWNER_KERNEL; | |
294 | } | |
295 | ||
e5d1367f SE |
296 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
297 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
298 | PERF_FLAG_PID_CGROUP |\ |
299 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 300 | |
bce38cd5 SE |
301 | /* |
302 | * branch priv levels that need permission checks | |
303 | */ | |
304 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
305 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
306 | PERF_SAMPLE_BRANCH_HV) | |
307 | ||
0b3fcf17 SE |
308 | enum event_type_t { |
309 | EVENT_FLEXIBLE = 0x1, | |
310 | EVENT_PINNED = 0x2, | |
311 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
312 | }; | |
313 | ||
e5d1367f SE |
314 | /* |
315 | * perf_sched_events : >0 events exist | |
316 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
317 | */ | |
c5905afb | 318 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 319 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 320 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 321 | |
cdd6c482 IM |
322 | static atomic_t nr_mmap_events __read_mostly; |
323 | static atomic_t nr_comm_events __read_mostly; | |
324 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 325 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 326 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 327 | |
108b02cf PZ |
328 | static LIST_HEAD(pmus); |
329 | static DEFINE_MUTEX(pmus_lock); | |
330 | static struct srcu_struct pmus_srcu; | |
331 | ||
0764771d | 332 | /* |
cdd6c482 | 333 | * perf event paranoia level: |
0fbdea19 IM |
334 | * -1 - not paranoid at all |
335 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 336 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 337 | * 2 - disallow kernel profiling for unpriv |
0764771d | 338 | */ |
cdd6c482 | 339 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 340 | |
20443384 FW |
341 | /* Minimum for 512 kiB + 1 user control page */ |
342 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
343 | |
344 | /* | |
cdd6c482 | 345 | * max perf event sample rate |
df58ab24 | 346 | */ |
14c63f17 DH |
347 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
348 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
349 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
350 | ||
351 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
352 | ||
353 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
354 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
355 | ||
d9494cb4 PZ |
356 | static int perf_sample_allowed_ns __read_mostly = |
357 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 358 | |
18ab2cd3 | 359 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
360 | { |
361 | u64 tmp = perf_sample_period_ns; | |
362 | ||
363 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 364 | do_div(tmp, 100); |
d9494cb4 | 365 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 366 | } |
163ec435 | 367 | |
9e630205 SE |
368 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
369 | ||
163ec435 PZ |
370 | int perf_proc_update_handler(struct ctl_table *table, int write, |
371 | void __user *buffer, size_t *lenp, | |
372 | loff_t *ppos) | |
373 | { | |
723478c8 | 374 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
375 | |
376 | if (ret || !write) | |
377 | return ret; | |
378 | ||
379 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
380 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
381 | update_perf_cpu_limits(); | |
382 | ||
383 | return 0; | |
384 | } | |
385 | ||
386 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
387 | ||
388 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
389 | void __user *buffer, size_t *lenp, | |
390 | loff_t *ppos) | |
391 | { | |
392 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
393 | ||
394 | if (ret || !write) | |
395 | return ret; | |
396 | ||
397 | update_perf_cpu_limits(); | |
163ec435 PZ |
398 | |
399 | return 0; | |
400 | } | |
1ccd1549 | 401 | |
14c63f17 DH |
402 | /* |
403 | * perf samples are done in some very critical code paths (NMIs). | |
404 | * If they take too much CPU time, the system can lock up and not | |
405 | * get any real work done. This will drop the sample rate when | |
406 | * we detect that events are taking too long. | |
407 | */ | |
408 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 409 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 410 | |
6a02ad66 | 411 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 412 | { |
6a02ad66 | 413 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 414 | u64 avg_local_sample_len; |
e5302920 | 415 | u64 local_samples_len; |
6a02ad66 | 416 | |
4a32fea9 | 417 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
418 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
419 | ||
420 | printk_ratelimited(KERN_WARNING | |
421 | "perf interrupt took too long (%lld > %lld), lowering " | |
422 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 423 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
424 | sysctl_perf_event_sample_rate); |
425 | } | |
426 | ||
427 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
428 | ||
429 | void perf_sample_event_took(u64 sample_len_ns) | |
430 | { | |
d9494cb4 | 431 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
432 | u64 avg_local_sample_len; |
433 | u64 local_samples_len; | |
14c63f17 | 434 | |
d9494cb4 | 435 | if (allowed_ns == 0) |
14c63f17 DH |
436 | return; |
437 | ||
438 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 439 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
440 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
441 | local_samples_len += sample_len_ns; | |
4a32fea9 | 442 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
443 | |
444 | /* | |
445 | * note: this will be biased artifically low until we have | |
446 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
447 | * from having to maintain a count. | |
448 | */ | |
449 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
450 | ||
d9494cb4 | 451 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
452 | return; |
453 | ||
454 | if (max_samples_per_tick <= 1) | |
455 | return; | |
456 | ||
457 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
458 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
459 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
460 | ||
14c63f17 | 461 | update_perf_cpu_limits(); |
6a02ad66 | 462 | |
cd578abb PZ |
463 | if (!irq_work_queue(&perf_duration_work)) { |
464 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
465 | "kernel.perf_event_max_sample_rate to %d\n", | |
466 | avg_local_sample_len, allowed_ns >> 1, | |
467 | sysctl_perf_event_sample_rate); | |
468 | } | |
14c63f17 DH |
469 | } |
470 | ||
cdd6c482 | 471 | static atomic64_t perf_event_id; |
a96bbc16 | 472 | |
0b3fcf17 SE |
473 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
474 | enum event_type_t event_type); | |
475 | ||
476 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
477 | enum event_type_t event_type, |
478 | struct task_struct *task); | |
479 | ||
480 | static void update_context_time(struct perf_event_context *ctx); | |
481 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 482 | |
cdd6c482 | 483 | void __weak perf_event_print_debug(void) { } |
0793a61d | 484 | |
84c79910 | 485 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 486 | { |
84c79910 | 487 | return "pmu"; |
0793a61d TG |
488 | } |
489 | ||
0b3fcf17 SE |
490 | static inline u64 perf_clock(void) |
491 | { | |
492 | return local_clock(); | |
493 | } | |
494 | ||
34f43927 PZ |
495 | static inline u64 perf_event_clock(struct perf_event *event) |
496 | { | |
497 | return event->clock(); | |
498 | } | |
499 | ||
e5d1367f SE |
500 | #ifdef CONFIG_CGROUP_PERF |
501 | ||
e5d1367f SE |
502 | static inline bool |
503 | perf_cgroup_match(struct perf_event *event) | |
504 | { | |
505 | struct perf_event_context *ctx = event->ctx; | |
506 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
507 | ||
ef824fa1 TH |
508 | /* @event doesn't care about cgroup */ |
509 | if (!event->cgrp) | |
510 | return true; | |
511 | ||
512 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
513 | if (!cpuctx->cgrp) | |
514 | return false; | |
515 | ||
516 | /* | |
517 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
518 | * also enabled for all its descendant cgroups. If @cpuctx's | |
519 | * cgroup is a descendant of @event's (the test covers identity | |
520 | * case), it's a match. | |
521 | */ | |
522 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
523 | event->cgrp->css.cgroup); | |
e5d1367f SE |
524 | } |
525 | ||
e5d1367f SE |
526 | static inline void perf_detach_cgroup(struct perf_event *event) |
527 | { | |
4e2ba650 | 528 | css_put(&event->cgrp->css); |
e5d1367f SE |
529 | event->cgrp = NULL; |
530 | } | |
531 | ||
532 | static inline int is_cgroup_event(struct perf_event *event) | |
533 | { | |
534 | return event->cgrp != NULL; | |
535 | } | |
536 | ||
537 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
538 | { | |
539 | struct perf_cgroup_info *t; | |
540 | ||
541 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
542 | return t->time; | |
543 | } | |
544 | ||
545 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
546 | { | |
547 | struct perf_cgroup_info *info; | |
548 | u64 now; | |
549 | ||
550 | now = perf_clock(); | |
551 | ||
552 | info = this_cpu_ptr(cgrp->info); | |
553 | ||
554 | info->time += now - info->timestamp; | |
555 | info->timestamp = now; | |
556 | } | |
557 | ||
558 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
559 | { | |
560 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
561 | if (cgrp_out) | |
562 | __update_cgrp_time(cgrp_out); | |
563 | } | |
564 | ||
565 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
566 | { | |
3f7cce3c SE |
567 | struct perf_cgroup *cgrp; |
568 | ||
e5d1367f | 569 | /* |
3f7cce3c SE |
570 | * ensure we access cgroup data only when needed and |
571 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 572 | */ |
3f7cce3c | 573 | if (!is_cgroup_event(event)) |
e5d1367f SE |
574 | return; |
575 | ||
614e4c4e | 576 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
577 | /* |
578 | * Do not update time when cgroup is not active | |
579 | */ | |
580 | if (cgrp == event->cgrp) | |
581 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
582 | } |
583 | ||
584 | static inline void | |
3f7cce3c SE |
585 | perf_cgroup_set_timestamp(struct task_struct *task, |
586 | struct perf_event_context *ctx) | |
e5d1367f SE |
587 | { |
588 | struct perf_cgroup *cgrp; | |
589 | struct perf_cgroup_info *info; | |
590 | ||
3f7cce3c SE |
591 | /* |
592 | * ctx->lock held by caller | |
593 | * ensure we do not access cgroup data | |
594 | * unless we have the cgroup pinned (css_get) | |
595 | */ | |
596 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
597 | return; |
598 | ||
614e4c4e | 599 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 600 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 601 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
602 | } |
603 | ||
604 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
605 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
606 | ||
607 | /* | |
608 | * reschedule events based on the cgroup constraint of task. | |
609 | * | |
610 | * mode SWOUT : schedule out everything | |
611 | * mode SWIN : schedule in based on cgroup for next | |
612 | */ | |
18ab2cd3 | 613 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
614 | { |
615 | struct perf_cpu_context *cpuctx; | |
616 | struct pmu *pmu; | |
617 | unsigned long flags; | |
618 | ||
619 | /* | |
620 | * disable interrupts to avoid geting nr_cgroup | |
621 | * changes via __perf_event_disable(). Also | |
622 | * avoids preemption. | |
623 | */ | |
624 | local_irq_save(flags); | |
625 | ||
626 | /* | |
627 | * we reschedule only in the presence of cgroup | |
628 | * constrained events. | |
629 | */ | |
e5d1367f SE |
630 | |
631 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 632 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
633 | if (cpuctx->unique_pmu != pmu) |
634 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 635 | |
e5d1367f SE |
636 | /* |
637 | * perf_cgroup_events says at least one | |
638 | * context on this CPU has cgroup events. | |
639 | * | |
640 | * ctx->nr_cgroups reports the number of cgroup | |
641 | * events for a context. | |
642 | */ | |
643 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
644 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
645 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
646 | |
647 | if (mode & PERF_CGROUP_SWOUT) { | |
648 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
649 | /* | |
650 | * must not be done before ctxswout due | |
651 | * to event_filter_match() in event_sched_out() | |
652 | */ | |
653 | cpuctx->cgrp = NULL; | |
654 | } | |
655 | ||
656 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 657 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
658 | /* |
659 | * set cgrp before ctxsw in to allow | |
660 | * event_filter_match() to not have to pass | |
661 | * task around | |
614e4c4e SE |
662 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
663 | * because cgorup events are only per-cpu | |
e5d1367f | 664 | */ |
614e4c4e | 665 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
666 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
667 | } | |
facc4307 PZ |
668 | perf_pmu_enable(cpuctx->ctx.pmu); |
669 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 670 | } |
e5d1367f SE |
671 | } |
672 | ||
e5d1367f SE |
673 | local_irq_restore(flags); |
674 | } | |
675 | ||
a8d757ef SE |
676 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
677 | struct task_struct *next) | |
e5d1367f | 678 | { |
a8d757ef SE |
679 | struct perf_cgroup *cgrp1; |
680 | struct perf_cgroup *cgrp2 = NULL; | |
681 | ||
ddaaf4e2 | 682 | rcu_read_lock(); |
a8d757ef SE |
683 | /* |
684 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
685 | * we do not need to pass the ctx here because we know |
686 | * we are holding the rcu lock | |
a8d757ef | 687 | */ |
614e4c4e | 688 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 689 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
690 | |
691 | /* | |
692 | * only schedule out current cgroup events if we know | |
693 | * that we are switching to a different cgroup. Otherwise, | |
694 | * do no touch the cgroup events. | |
695 | */ | |
696 | if (cgrp1 != cgrp2) | |
697 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
698 | |
699 | rcu_read_unlock(); | |
e5d1367f SE |
700 | } |
701 | ||
a8d757ef SE |
702 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
703 | struct task_struct *task) | |
e5d1367f | 704 | { |
a8d757ef SE |
705 | struct perf_cgroup *cgrp1; |
706 | struct perf_cgroup *cgrp2 = NULL; | |
707 | ||
ddaaf4e2 | 708 | rcu_read_lock(); |
a8d757ef SE |
709 | /* |
710 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
711 | * we do not need to pass the ctx here because we know |
712 | * we are holding the rcu lock | |
a8d757ef | 713 | */ |
614e4c4e | 714 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 715 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
716 | |
717 | /* | |
718 | * only need to schedule in cgroup events if we are changing | |
719 | * cgroup during ctxsw. Cgroup events were not scheduled | |
720 | * out of ctxsw out if that was not the case. | |
721 | */ | |
722 | if (cgrp1 != cgrp2) | |
723 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
724 | |
725 | rcu_read_unlock(); | |
e5d1367f SE |
726 | } |
727 | ||
728 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
729 | struct perf_event_attr *attr, | |
730 | struct perf_event *group_leader) | |
731 | { | |
732 | struct perf_cgroup *cgrp; | |
733 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
734 | struct fd f = fdget(fd); |
735 | int ret = 0; | |
e5d1367f | 736 | |
2903ff01 | 737 | if (!f.file) |
e5d1367f SE |
738 | return -EBADF; |
739 | ||
b583043e | 740 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 741 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
742 | if (IS_ERR(css)) { |
743 | ret = PTR_ERR(css); | |
744 | goto out; | |
745 | } | |
e5d1367f SE |
746 | |
747 | cgrp = container_of(css, struct perf_cgroup, css); | |
748 | event->cgrp = cgrp; | |
749 | ||
750 | /* | |
751 | * all events in a group must monitor | |
752 | * the same cgroup because a task belongs | |
753 | * to only one perf cgroup at a time | |
754 | */ | |
755 | if (group_leader && group_leader->cgrp != cgrp) { | |
756 | perf_detach_cgroup(event); | |
757 | ret = -EINVAL; | |
e5d1367f | 758 | } |
3db272c0 | 759 | out: |
2903ff01 | 760 | fdput(f); |
e5d1367f SE |
761 | return ret; |
762 | } | |
763 | ||
764 | static inline void | |
765 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
766 | { | |
767 | struct perf_cgroup_info *t; | |
768 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
769 | event->shadow_ctx_time = now - t->timestamp; | |
770 | } | |
771 | ||
772 | static inline void | |
773 | perf_cgroup_defer_enabled(struct perf_event *event) | |
774 | { | |
775 | /* | |
776 | * when the current task's perf cgroup does not match | |
777 | * the event's, we need to remember to call the | |
778 | * perf_mark_enable() function the first time a task with | |
779 | * a matching perf cgroup is scheduled in. | |
780 | */ | |
781 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
782 | event->cgrp_defer_enabled = 1; | |
783 | } | |
784 | ||
785 | static inline void | |
786 | perf_cgroup_mark_enabled(struct perf_event *event, | |
787 | struct perf_event_context *ctx) | |
788 | { | |
789 | struct perf_event *sub; | |
790 | u64 tstamp = perf_event_time(event); | |
791 | ||
792 | if (!event->cgrp_defer_enabled) | |
793 | return; | |
794 | ||
795 | event->cgrp_defer_enabled = 0; | |
796 | ||
797 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
798 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
799 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
800 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
801 | sub->cgrp_defer_enabled = 0; | |
802 | } | |
803 | } | |
804 | } | |
805 | #else /* !CONFIG_CGROUP_PERF */ | |
806 | ||
807 | static inline bool | |
808 | perf_cgroup_match(struct perf_event *event) | |
809 | { | |
810 | return true; | |
811 | } | |
812 | ||
813 | static inline void perf_detach_cgroup(struct perf_event *event) | |
814 | {} | |
815 | ||
816 | static inline int is_cgroup_event(struct perf_event *event) | |
817 | { | |
818 | return 0; | |
819 | } | |
820 | ||
821 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
822 | { | |
823 | return 0; | |
824 | } | |
825 | ||
826 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
827 | { | |
828 | } | |
829 | ||
830 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
831 | { | |
832 | } | |
833 | ||
a8d757ef SE |
834 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
835 | struct task_struct *next) | |
e5d1367f SE |
836 | { |
837 | } | |
838 | ||
a8d757ef SE |
839 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
840 | struct task_struct *task) | |
e5d1367f SE |
841 | { |
842 | } | |
843 | ||
844 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
845 | struct perf_event_attr *attr, | |
846 | struct perf_event *group_leader) | |
847 | { | |
848 | return -EINVAL; | |
849 | } | |
850 | ||
851 | static inline void | |
3f7cce3c SE |
852 | perf_cgroup_set_timestamp(struct task_struct *task, |
853 | struct perf_event_context *ctx) | |
e5d1367f SE |
854 | { |
855 | } | |
856 | ||
857 | void | |
858 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
859 | { | |
860 | } | |
861 | ||
862 | static inline void | |
863 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
864 | { | |
865 | } | |
866 | ||
867 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
868 | { | |
869 | return 0; | |
870 | } | |
871 | ||
872 | static inline void | |
873 | perf_cgroup_defer_enabled(struct perf_event *event) | |
874 | { | |
875 | } | |
876 | ||
877 | static inline void | |
878 | perf_cgroup_mark_enabled(struct perf_event *event, | |
879 | struct perf_event_context *ctx) | |
880 | { | |
881 | } | |
882 | #endif | |
883 | ||
9e630205 SE |
884 | /* |
885 | * set default to be dependent on timer tick just | |
886 | * like original code | |
887 | */ | |
888 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
889 | /* | |
890 | * function must be called with interrupts disbled | |
891 | */ | |
272325c4 | 892 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
893 | { |
894 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
895 | int rotations = 0; |
896 | ||
897 | WARN_ON(!irqs_disabled()); | |
898 | ||
899 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
900 | rotations = perf_rotate_context(cpuctx); |
901 | ||
4cfafd30 PZ |
902 | raw_spin_lock(&cpuctx->hrtimer_lock); |
903 | if (rotations) | |
9e630205 | 904 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
905 | else |
906 | cpuctx->hrtimer_active = 0; | |
907 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 908 | |
4cfafd30 | 909 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
910 | } |
911 | ||
272325c4 | 912 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 913 | { |
272325c4 | 914 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 915 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 916 | u64 interval; |
9e630205 SE |
917 | |
918 | /* no multiplexing needed for SW PMU */ | |
919 | if (pmu->task_ctx_nr == perf_sw_context) | |
920 | return; | |
921 | ||
62b85639 SE |
922 | /* |
923 | * check default is sane, if not set then force to | |
924 | * default interval (1/tick) | |
925 | */ | |
272325c4 PZ |
926 | interval = pmu->hrtimer_interval_ms; |
927 | if (interval < 1) | |
928 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 929 | |
272325c4 | 930 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 931 | |
4cfafd30 PZ |
932 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
933 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 934 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
935 | } |
936 | ||
272325c4 | 937 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 938 | { |
272325c4 | 939 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 940 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 941 | unsigned long flags; |
9e630205 SE |
942 | |
943 | /* not for SW PMU */ | |
944 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 945 | return 0; |
9e630205 | 946 | |
4cfafd30 PZ |
947 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
948 | if (!cpuctx->hrtimer_active) { | |
949 | cpuctx->hrtimer_active = 1; | |
950 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
951 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
952 | } | |
953 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 954 | |
272325c4 | 955 | return 0; |
9e630205 SE |
956 | } |
957 | ||
33696fc0 | 958 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 959 | { |
33696fc0 PZ |
960 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
961 | if (!(*count)++) | |
962 | pmu->pmu_disable(pmu); | |
9e35ad38 | 963 | } |
9e35ad38 | 964 | |
33696fc0 | 965 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 966 | { |
33696fc0 PZ |
967 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
968 | if (!--(*count)) | |
969 | pmu->pmu_enable(pmu); | |
9e35ad38 | 970 | } |
9e35ad38 | 971 | |
2fde4f94 | 972 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
973 | |
974 | /* | |
2fde4f94 MR |
975 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
976 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
977 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
978 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 979 | */ |
2fde4f94 | 980 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 981 | { |
2fde4f94 | 982 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 983 | |
e9d2b064 | 984 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 985 | |
2fde4f94 MR |
986 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
987 | ||
988 | list_add(&ctx->active_ctx_list, head); | |
989 | } | |
990 | ||
991 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
992 | { | |
993 | WARN_ON(!irqs_disabled()); | |
994 | ||
995 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
996 | ||
997 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 998 | } |
9e35ad38 | 999 | |
cdd6c482 | 1000 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1001 | { |
e5289d4a | 1002 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1003 | } |
1004 | ||
4af57ef2 YZ |
1005 | static void free_ctx(struct rcu_head *head) |
1006 | { | |
1007 | struct perf_event_context *ctx; | |
1008 | ||
1009 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1010 | kfree(ctx->task_ctx_data); | |
1011 | kfree(ctx); | |
1012 | } | |
1013 | ||
cdd6c482 | 1014 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1015 | { |
564c2b21 PM |
1016 | if (atomic_dec_and_test(&ctx->refcount)) { |
1017 | if (ctx->parent_ctx) | |
1018 | put_ctx(ctx->parent_ctx); | |
c93f7669 PM |
1019 | if (ctx->task) |
1020 | put_task_struct(ctx->task); | |
4af57ef2 | 1021 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1022 | } |
a63eaf34 PM |
1023 | } |
1024 | ||
f63a8daa PZ |
1025 | /* |
1026 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1027 | * perf_pmu_migrate_context() we need some magic. | |
1028 | * | |
1029 | * Those places that change perf_event::ctx will hold both | |
1030 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1031 | * | |
8b10c5e2 PZ |
1032 | * Lock ordering is by mutex address. There are two other sites where |
1033 | * perf_event_context::mutex nests and those are: | |
1034 | * | |
1035 | * - perf_event_exit_task_context() [ child , 0 ] | |
1036 | * __perf_event_exit_task() | |
1037 | * sync_child_event() | |
1038 | * put_event() [ parent, 1 ] | |
1039 | * | |
1040 | * - perf_event_init_context() [ parent, 0 ] | |
1041 | * inherit_task_group() | |
1042 | * inherit_group() | |
1043 | * inherit_event() | |
1044 | * perf_event_alloc() | |
1045 | * perf_init_event() | |
1046 | * perf_try_init_event() [ child , 1 ] | |
1047 | * | |
1048 | * While it appears there is an obvious deadlock here -- the parent and child | |
1049 | * nesting levels are inverted between the two. This is in fact safe because | |
1050 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1051 | * spawning task cannot (yet) exit. | |
1052 | * | |
1053 | * But remember that that these are parent<->child context relations, and | |
1054 | * migration does not affect children, therefore these two orderings should not | |
1055 | * interact. | |
f63a8daa PZ |
1056 | * |
1057 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1058 | * because the sys_perf_event_open() case will install a new event and break | |
1059 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1060 | * concerned with cpuctx and that doesn't have children. | |
1061 | * | |
1062 | * The places that change perf_event::ctx will issue: | |
1063 | * | |
1064 | * perf_remove_from_context(); | |
1065 | * synchronize_rcu(); | |
1066 | * perf_install_in_context(); | |
1067 | * | |
1068 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1069 | * quiesce the event, after which we can install it in the new location. This | |
1070 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1071 | * while in transit. Therefore all such accessors should also acquire | |
1072 | * perf_event_context::mutex to serialize against this. | |
1073 | * | |
1074 | * However; because event->ctx can change while we're waiting to acquire | |
1075 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1076 | * function. | |
1077 | * | |
1078 | * Lock order: | |
1079 | * task_struct::perf_event_mutex | |
1080 | * perf_event_context::mutex | |
1081 | * perf_event_context::lock | |
1082 | * perf_event::child_mutex; | |
1083 | * perf_event::mmap_mutex | |
1084 | * mmap_sem | |
1085 | */ | |
a83fe28e PZ |
1086 | static struct perf_event_context * |
1087 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1088 | { |
1089 | struct perf_event_context *ctx; | |
1090 | ||
1091 | again: | |
1092 | rcu_read_lock(); | |
1093 | ctx = ACCESS_ONCE(event->ctx); | |
1094 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1095 | rcu_read_unlock(); | |
1096 | goto again; | |
1097 | } | |
1098 | rcu_read_unlock(); | |
1099 | ||
a83fe28e | 1100 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1101 | if (event->ctx != ctx) { |
1102 | mutex_unlock(&ctx->mutex); | |
1103 | put_ctx(ctx); | |
1104 | goto again; | |
1105 | } | |
1106 | ||
1107 | return ctx; | |
1108 | } | |
1109 | ||
a83fe28e PZ |
1110 | static inline struct perf_event_context * |
1111 | perf_event_ctx_lock(struct perf_event *event) | |
1112 | { | |
1113 | return perf_event_ctx_lock_nested(event, 0); | |
1114 | } | |
1115 | ||
f63a8daa PZ |
1116 | static void perf_event_ctx_unlock(struct perf_event *event, |
1117 | struct perf_event_context *ctx) | |
1118 | { | |
1119 | mutex_unlock(&ctx->mutex); | |
1120 | put_ctx(ctx); | |
1121 | } | |
1122 | ||
211de6eb PZ |
1123 | /* |
1124 | * This must be done under the ctx->lock, such as to serialize against | |
1125 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1126 | * calling scheduler related locks and ctx->lock nests inside those. | |
1127 | */ | |
1128 | static __must_check struct perf_event_context * | |
1129 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1130 | { |
211de6eb PZ |
1131 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1132 | ||
1133 | lockdep_assert_held(&ctx->lock); | |
1134 | ||
1135 | if (parent_ctx) | |
71a851b4 | 1136 | ctx->parent_ctx = NULL; |
5a3126d4 | 1137 | ctx->generation++; |
211de6eb PZ |
1138 | |
1139 | return parent_ctx; | |
71a851b4 PZ |
1140 | } |
1141 | ||
6844c09d ACM |
1142 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1143 | { | |
1144 | /* | |
1145 | * only top level events have the pid namespace they were created in | |
1146 | */ | |
1147 | if (event->parent) | |
1148 | event = event->parent; | |
1149 | ||
1150 | return task_tgid_nr_ns(p, event->ns); | |
1151 | } | |
1152 | ||
1153 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1154 | { | |
1155 | /* | |
1156 | * only top level events have the pid namespace they were created in | |
1157 | */ | |
1158 | if (event->parent) | |
1159 | event = event->parent; | |
1160 | ||
1161 | return task_pid_nr_ns(p, event->ns); | |
1162 | } | |
1163 | ||
7f453c24 | 1164 | /* |
cdd6c482 | 1165 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1166 | * to userspace. |
1167 | */ | |
cdd6c482 | 1168 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1169 | { |
cdd6c482 | 1170 | u64 id = event->id; |
7f453c24 | 1171 | |
cdd6c482 IM |
1172 | if (event->parent) |
1173 | id = event->parent->id; | |
7f453c24 PZ |
1174 | |
1175 | return id; | |
1176 | } | |
1177 | ||
25346b93 | 1178 | /* |
cdd6c482 | 1179 | * Get the perf_event_context for a task and lock it. |
25346b93 PM |
1180 | * This has to cope with with the fact that until it is locked, |
1181 | * the context could get moved to another task. | |
1182 | */ | |
cdd6c482 | 1183 | static struct perf_event_context * |
8dc85d54 | 1184 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1185 | { |
cdd6c482 | 1186 | struct perf_event_context *ctx; |
25346b93 | 1187 | |
9ed6060d | 1188 | retry: |
058ebd0e PZ |
1189 | /* |
1190 | * One of the few rules of preemptible RCU is that one cannot do | |
1191 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1192 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1193 | * rcu_read_unlock_special(). |
1194 | * | |
1195 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1196 | * side critical section has interrupts disabled. |
058ebd0e | 1197 | */ |
2fd59077 | 1198 | local_irq_save(*flags); |
058ebd0e | 1199 | rcu_read_lock(); |
8dc85d54 | 1200 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1201 | if (ctx) { |
1202 | /* | |
1203 | * If this context is a clone of another, it might | |
1204 | * get swapped for another underneath us by | |
cdd6c482 | 1205 | * perf_event_task_sched_out, though the |
25346b93 PM |
1206 | * rcu_read_lock() protects us from any context |
1207 | * getting freed. Lock the context and check if it | |
1208 | * got swapped before we could get the lock, and retry | |
1209 | * if so. If we locked the right context, then it | |
1210 | * can't get swapped on us any more. | |
1211 | */ | |
2fd59077 | 1212 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1213 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1214 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1215 | rcu_read_unlock(); |
2fd59077 | 1216 | local_irq_restore(*flags); |
25346b93 PM |
1217 | goto retry; |
1218 | } | |
b49a9e7e PZ |
1219 | |
1220 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1221 | raw_spin_unlock(&ctx->lock); |
b49a9e7e PZ |
1222 | ctx = NULL; |
1223 | } | |
25346b93 PM |
1224 | } |
1225 | rcu_read_unlock(); | |
2fd59077 PM |
1226 | if (!ctx) |
1227 | local_irq_restore(*flags); | |
25346b93 PM |
1228 | return ctx; |
1229 | } | |
1230 | ||
1231 | /* | |
1232 | * Get the context for a task and increment its pin_count so it | |
1233 | * can't get swapped to another task. This also increments its | |
1234 | * reference count so that the context can't get freed. | |
1235 | */ | |
8dc85d54 PZ |
1236 | static struct perf_event_context * |
1237 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1238 | { |
cdd6c482 | 1239 | struct perf_event_context *ctx; |
25346b93 PM |
1240 | unsigned long flags; |
1241 | ||
8dc85d54 | 1242 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1243 | if (ctx) { |
1244 | ++ctx->pin_count; | |
e625cce1 | 1245 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1246 | } |
1247 | return ctx; | |
1248 | } | |
1249 | ||
cdd6c482 | 1250 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1251 | { |
1252 | unsigned long flags; | |
1253 | ||
e625cce1 | 1254 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1255 | --ctx->pin_count; |
e625cce1 | 1256 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1257 | } |
1258 | ||
f67218c3 PZ |
1259 | /* |
1260 | * Update the record of the current time in a context. | |
1261 | */ | |
1262 | static void update_context_time(struct perf_event_context *ctx) | |
1263 | { | |
1264 | u64 now = perf_clock(); | |
1265 | ||
1266 | ctx->time += now - ctx->timestamp; | |
1267 | ctx->timestamp = now; | |
1268 | } | |
1269 | ||
4158755d SE |
1270 | static u64 perf_event_time(struct perf_event *event) |
1271 | { | |
1272 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1273 | |
1274 | if (is_cgroup_event(event)) | |
1275 | return perf_cgroup_event_time(event); | |
1276 | ||
4158755d SE |
1277 | return ctx ? ctx->time : 0; |
1278 | } | |
1279 | ||
f67218c3 PZ |
1280 | /* |
1281 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1282 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1283 | */ |
1284 | static void update_event_times(struct perf_event *event) | |
1285 | { | |
1286 | struct perf_event_context *ctx = event->ctx; | |
1287 | u64 run_end; | |
1288 | ||
1289 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1290 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1291 | return; | |
e5d1367f SE |
1292 | /* |
1293 | * in cgroup mode, time_enabled represents | |
1294 | * the time the event was enabled AND active | |
1295 | * tasks were in the monitored cgroup. This is | |
1296 | * independent of the activity of the context as | |
1297 | * there may be a mix of cgroup and non-cgroup events. | |
1298 | * | |
1299 | * That is why we treat cgroup events differently | |
1300 | * here. | |
1301 | */ | |
1302 | if (is_cgroup_event(event)) | |
46cd6a7f | 1303 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1304 | else if (ctx->is_active) |
1305 | run_end = ctx->time; | |
acd1d7c1 PZ |
1306 | else |
1307 | run_end = event->tstamp_stopped; | |
1308 | ||
1309 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1310 | |
1311 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1312 | run_end = event->tstamp_stopped; | |
1313 | else | |
4158755d | 1314 | run_end = perf_event_time(event); |
f67218c3 PZ |
1315 | |
1316 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1317 | |
f67218c3 PZ |
1318 | } |
1319 | ||
96c21a46 PZ |
1320 | /* |
1321 | * Update total_time_enabled and total_time_running for all events in a group. | |
1322 | */ | |
1323 | static void update_group_times(struct perf_event *leader) | |
1324 | { | |
1325 | struct perf_event *event; | |
1326 | ||
1327 | update_event_times(leader); | |
1328 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1329 | update_event_times(event); | |
1330 | } | |
1331 | ||
889ff015 FW |
1332 | static struct list_head * |
1333 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1334 | { | |
1335 | if (event->attr.pinned) | |
1336 | return &ctx->pinned_groups; | |
1337 | else | |
1338 | return &ctx->flexible_groups; | |
1339 | } | |
1340 | ||
fccc714b | 1341 | /* |
cdd6c482 | 1342 | * Add a event from the lists for its context. |
fccc714b PZ |
1343 | * Must be called with ctx->mutex and ctx->lock held. |
1344 | */ | |
04289bb9 | 1345 | static void |
cdd6c482 | 1346 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1347 | { |
c994d613 PZ |
1348 | lockdep_assert_held(&ctx->lock); |
1349 | ||
8a49542c PZ |
1350 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1351 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1352 | |
1353 | /* | |
8a49542c PZ |
1354 | * If we're a stand alone event or group leader, we go to the context |
1355 | * list, group events are kept attached to the group so that | |
1356 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1357 | */ |
8a49542c | 1358 | if (event->group_leader == event) { |
889ff015 FW |
1359 | struct list_head *list; |
1360 | ||
d6f962b5 FW |
1361 | if (is_software_event(event)) |
1362 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1363 | ||
889ff015 FW |
1364 | list = ctx_group_list(event, ctx); |
1365 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1366 | } |
592903cd | 1367 | |
08309379 | 1368 | if (is_cgroup_event(event)) |
e5d1367f | 1369 | ctx->nr_cgroups++; |
e5d1367f | 1370 | |
cdd6c482 IM |
1371 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1372 | ctx->nr_events++; | |
1373 | if (event->attr.inherit_stat) | |
bfbd3381 | 1374 | ctx->nr_stat++; |
5a3126d4 PZ |
1375 | |
1376 | ctx->generation++; | |
04289bb9 IM |
1377 | } |
1378 | ||
0231bb53 JO |
1379 | /* |
1380 | * Initialize event state based on the perf_event_attr::disabled. | |
1381 | */ | |
1382 | static inline void perf_event__state_init(struct perf_event *event) | |
1383 | { | |
1384 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1385 | PERF_EVENT_STATE_INACTIVE; | |
1386 | } | |
1387 | ||
a723968c | 1388 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1389 | { |
1390 | int entry = sizeof(u64); /* value */ | |
1391 | int size = 0; | |
1392 | int nr = 1; | |
1393 | ||
1394 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1395 | size += sizeof(u64); | |
1396 | ||
1397 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1398 | size += sizeof(u64); | |
1399 | ||
1400 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1401 | entry += sizeof(u64); | |
1402 | ||
1403 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1404 | nr += nr_siblings; |
c320c7b7 ACM |
1405 | size += sizeof(u64); |
1406 | } | |
1407 | ||
1408 | size += entry * nr; | |
1409 | event->read_size = size; | |
1410 | } | |
1411 | ||
a723968c | 1412 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1413 | { |
1414 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1415 | u16 size = 0; |
1416 | ||
c320c7b7 ACM |
1417 | if (sample_type & PERF_SAMPLE_IP) |
1418 | size += sizeof(data->ip); | |
1419 | ||
6844c09d ACM |
1420 | if (sample_type & PERF_SAMPLE_ADDR) |
1421 | size += sizeof(data->addr); | |
1422 | ||
1423 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1424 | size += sizeof(data->period); | |
1425 | ||
c3feedf2 AK |
1426 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1427 | size += sizeof(data->weight); | |
1428 | ||
6844c09d ACM |
1429 | if (sample_type & PERF_SAMPLE_READ) |
1430 | size += event->read_size; | |
1431 | ||
d6be9ad6 SE |
1432 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1433 | size += sizeof(data->data_src.val); | |
1434 | ||
fdfbbd07 AK |
1435 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1436 | size += sizeof(data->txn); | |
1437 | ||
6844c09d ACM |
1438 | event->header_size = size; |
1439 | } | |
1440 | ||
a723968c PZ |
1441 | /* |
1442 | * Called at perf_event creation and when events are attached/detached from a | |
1443 | * group. | |
1444 | */ | |
1445 | static void perf_event__header_size(struct perf_event *event) | |
1446 | { | |
1447 | __perf_event_read_size(event, | |
1448 | event->group_leader->nr_siblings); | |
1449 | __perf_event_header_size(event, event->attr.sample_type); | |
1450 | } | |
1451 | ||
6844c09d ACM |
1452 | static void perf_event__id_header_size(struct perf_event *event) |
1453 | { | |
1454 | struct perf_sample_data *data; | |
1455 | u64 sample_type = event->attr.sample_type; | |
1456 | u16 size = 0; | |
1457 | ||
c320c7b7 ACM |
1458 | if (sample_type & PERF_SAMPLE_TID) |
1459 | size += sizeof(data->tid_entry); | |
1460 | ||
1461 | if (sample_type & PERF_SAMPLE_TIME) | |
1462 | size += sizeof(data->time); | |
1463 | ||
ff3d527c AH |
1464 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1465 | size += sizeof(data->id); | |
1466 | ||
c320c7b7 ACM |
1467 | if (sample_type & PERF_SAMPLE_ID) |
1468 | size += sizeof(data->id); | |
1469 | ||
1470 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1471 | size += sizeof(data->stream_id); | |
1472 | ||
1473 | if (sample_type & PERF_SAMPLE_CPU) | |
1474 | size += sizeof(data->cpu_entry); | |
1475 | ||
6844c09d | 1476 | event->id_header_size = size; |
c320c7b7 ACM |
1477 | } |
1478 | ||
a723968c PZ |
1479 | static bool perf_event_validate_size(struct perf_event *event) |
1480 | { | |
1481 | /* | |
1482 | * The values computed here will be over-written when we actually | |
1483 | * attach the event. | |
1484 | */ | |
1485 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1486 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1487 | perf_event__id_header_size(event); | |
1488 | ||
1489 | /* | |
1490 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1491 | * Conservative limit to allow for callchains and other variable fields. | |
1492 | */ | |
1493 | if (event->read_size + event->header_size + | |
1494 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1495 | return false; | |
1496 | ||
1497 | return true; | |
1498 | } | |
1499 | ||
8a49542c PZ |
1500 | static void perf_group_attach(struct perf_event *event) |
1501 | { | |
c320c7b7 | 1502 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1503 | |
74c3337c PZ |
1504 | /* |
1505 | * We can have double attach due to group movement in perf_event_open. | |
1506 | */ | |
1507 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1508 | return; | |
1509 | ||
8a49542c PZ |
1510 | event->attach_state |= PERF_ATTACH_GROUP; |
1511 | ||
1512 | if (group_leader == event) | |
1513 | return; | |
1514 | ||
652884fe PZ |
1515 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1516 | ||
8a49542c PZ |
1517 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1518 | !is_software_event(event)) | |
1519 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1520 | ||
1521 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1522 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1523 | |
1524 | perf_event__header_size(group_leader); | |
1525 | ||
1526 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1527 | perf_event__header_size(pos); | |
8a49542c PZ |
1528 | } |
1529 | ||
a63eaf34 | 1530 | /* |
cdd6c482 | 1531 | * Remove a event from the lists for its context. |
fccc714b | 1532 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1533 | */ |
04289bb9 | 1534 | static void |
cdd6c482 | 1535 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1536 | { |
68cacd29 | 1537 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1538 | |
1539 | WARN_ON_ONCE(event->ctx != ctx); | |
1540 | lockdep_assert_held(&ctx->lock); | |
1541 | ||
8a49542c PZ |
1542 | /* |
1543 | * We can have double detach due to exit/hot-unplug + close. | |
1544 | */ | |
1545 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1546 | return; |
8a49542c PZ |
1547 | |
1548 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1549 | ||
68cacd29 | 1550 | if (is_cgroup_event(event)) { |
e5d1367f | 1551 | ctx->nr_cgroups--; |
70a01657 PZ |
1552 | /* |
1553 | * Because cgroup events are always per-cpu events, this will | |
1554 | * always be called from the right CPU. | |
1555 | */ | |
68cacd29 SE |
1556 | cpuctx = __get_cpu_context(ctx); |
1557 | /* | |
70a01657 PZ |
1558 | * If there are no more cgroup events then clear cgrp to avoid |
1559 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1560 | */ |
1561 | if (!ctx->nr_cgroups) | |
1562 | cpuctx->cgrp = NULL; | |
1563 | } | |
e5d1367f | 1564 | |
cdd6c482 IM |
1565 | ctx->nr_events--; |
1566 | if (event->attr.inherit_stat) | |
bfbd3381 | 1567 | ctx->nr_stat--; |
8bc20959 | 1568 | |
cdd6c482 | 1569 | list_del_rcu(&event->event_entry); |
04289bb9 | 1570 | |
8a49542c PZ |
1571 | if (event->group_leader == event) |
1572 | list_del_init(&event->group_entry); | |
5c148194 | 1573 | |
96c21a46 | 1574 | update_group_times(event); |
b2e74a26 SE |
1575 | |
1576 | /* | |
1577 | * If event was in error state, then keep it | |
1578 | * that way, otherwise bogus counts will be | |
1579 | * returned on read(). The only way to get out | |
1580 | * of error state is by explicit re-enabling | |
1581 | * of the event | |
1582 | */ | |
1583 | if (event->state > PERF_EVENT_STATE_OFF) | |
1584 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1585 | |
1586 | ctx->generation++; | |
050735b0 PZ |
1587 | } |
1588 | ||
8a49542c | 1589 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1590 | { |
1591 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1592 | struct list_head *list = NULL; |
1593 | ||
1594 | /* | |
1595 | * We can have double detach due to exit/hot-unplug + close. | |
1596 | */ | |
1597 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1598 | return; | |
1599 | ||
1600 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1601 | ||
1602 | /* | |
1603 | * If this is a sibling, remove it from its group. | |
1604 | */ | |
1605 | if (event->group_leader != event) { | |
1606 | list_del_init(&event->group_entry); | |
1607 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1608 | goto out; |
8a49542c PZ |
1609 | } |
1610 | ||
1611 | if (!list_empty(&event->group_entry)) | |
1612 | list = &event->group_entry; | |
2e2af50b | 1613 | |
04289bb9 | 1614 | /* |
cdd6c482 IM |
1615 | * If this was a group event with sibling events then |
1616 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1617 | * to whatever list we are on. |
04289bb9 | 1618 | */ |
cdd6c482 | 1619 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1620 | if (list) |
1621 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1622 | sibling->group_leader = sibling; |
d6f962b5 FW |
1623 | |
1624 | /* Inherit group flags from the previous leader */ | |
1625 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1626 | |
1627 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1628 | } |
c320c7b7 ACM |
1629 | |
1630 | out: | |
1631 | perf_event__header_size(event->group_leader); | |
1632 | ||
1633 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1634 | perf_event__header_size(tmp); | |
04289bb9 IM |
1635 | } |
1636 | ||
fadfe7be JO |
1637 | /* |
1638 | * User event without the task. | |
1639 | */ | |
1640 | static bool is_orphaned_event(struct perf_event *event) | |
1641 | { | |
1642 | return event && !is_kernel_event(event) && !event->owner; | |
1643 | } | |
1644 | ||
1645 | /* | |
1646 | * Event has a parent but parent's task finished and it's | |
1647 | * alive only because of children holding refference. | |
1648 | */ | |
1649 | static bool is_orphaned_child(struct perf_event *event) | |
1650 | { | |
1651 | return is_orphaned_event(event->parent); | |
1652 | } | |
1653 | ||
1654 | static void orphans_remove_work(struct work_struct *work); | |
1655 | ||
1656 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1657 | { | |
1658 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1659 | return; | |
1660 | ||
1661 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1662 | get_ctx(ctx); | |
1663 | ctx->orphans_remove_sched = true; | |
1664 | } | |
1665 | } | |
1666 | ||
1667 | static int __init perf_workqueue_init(void) | |
1668 | { | |
1669 | perf_wq = create_singlethread_workqueue("perf"); | |
1670 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1671 | return perf_wq ? 0 : -1; | |
1672 | } | |
1673 | ||
1674 | core_initcall(perf_workqueue_init); | |
1675 | ||
66eb579e MR |
1676 | static inline int pmu_filter_match(struct perf_event *event) |
1677 | { | |
1678 | struct pmu *pmu = event->pmu; | |
1679 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1680 | } | |
1681 | ||
fa66f07a SE |
1682 | static inline int |
1683 | event_filter_match(struct perf_event *event) | |
1684 | { | |
e5d1367f | 1685 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1686 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1687 | } |
1688 | ||
9ffcfa6f SE |
1689 | static void |
1690 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1691 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1692 | struct perf_event_context *ctx) |
3b6f9e5c | 1693 | { |
4158755d | 1694 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1695 | u64 delta; |
652884fe PZ |
1696 | |
1697 | WARN_ON_ONCE(event->ctx != ctx); | |
1698 | lockdep_assert_held(&ctx->lock); | |
1699 | ||
fa66f07a SE |
1700 | /* |
1701 | * An event which could not be activated because of | |
1702 | * filter mismatch still needs to have its timings | |
1703 | * maintained, otherwise bogus information is return | |
1704 | * via read() for time_enabled, time_running: | |
1705 | */ | |
1706 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1707 | && !event_filter_match(event)) { | |
e5d1367f | 1708 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1709 | event->tstamp_running += delta; |
4158755d | 1710 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1711 | } |
1712 | ||
cdd6c482 | 1713 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1714 | return; |
3b6f9e5c | 1715 | |
44377277 AS |
1716 | perf_pmu_disable(event->pmu); |
1717 | ||
cdd6c482 IM |
1718 | event->state = PERF_EVENT_STATE_INACTIVE; |
1719 | if (event->pending_disable) { | |
1720 | event->pending_disable = 0; | |
1721 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1722 | } |
4158755d | 1723 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1724 | event->pmu->del(event, 0); |
cdd6c482 | 1725 | event->oncpu = -1; |
3b6f9e5c | 1726 | |
cdd6c482 | 1727 | if (!is_software_event(event)) |
3b6f9e5c | 1728 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1729 | if (!--ctx->nr_active) |
1730 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1731 | if (event->attr.freq && event->attr.sample_freq) |
1732 | ctx->nr_freq--; | |
cdd6c482 | 1733 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1734 | cpuctx->exclusive = 0; |
44377277 | 1735 | |
fadfe7be JO |
1736 | if (is_orphaned_child(event)) |
1737 | schedule_orphans_remove(ctx); | |
1738 | ||
44377277 | 1739 | perf_pmu_enable(event->pmu); |
3b6f9e5c PM |
1740 | } |
1741 | ||
d859e29f | 1742 | static void |
cdd6c482 | 1743 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1744 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1745 | struct perf_event_context *ctx) |
d859e29f | 1746 | { |
cdd6c482 | 1747 | struct perf_event *event; |
fa66f07a | 1748 | int state = group_event->state; |
d859e29f | 1749 | |
cdd6c482 | 1750 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1751 | |
1752 | /* | |
1753 | * Schedule out siblings (if any): | |
1754 | */ | |
cdd6c482 IM |
1755 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1756 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1757 | |
fa66f07a | 1758 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1759 | cpuctx->exclusive = 0; |
1760 | } | |
1761 | ||
0793a61d | 1762 | /* |
cdd6c482 | 1763 | * Cross CPU call to remove a performance event |
0793a61d | 1764 | * |
cdd6c482 | 1765 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1766 | * remove it from the context list. |
1767 | */ | |
fae3fde6 PZ |
1768 | static void |
1769 | __perf_remove_from_context(struct perf_event *event, | |
1770 | struct perf_cpu_context *cpuctx, | |
1771 | struct perf_event_context *ctx, | |
1772 | void *info) | |
0793a61d | 1773 | { |
fae3fde6 | 1774 | bool detach_group = (unsigned long)info; |
0793a61d | 1775 | |
cdd6c482 | 1776 | event_sched_out(event, cpuctx, ctx); |
fae3fde6 | 1777 | if (detach_group) |
46ce0fe9 | 1778 | perf_group_detach(event); |
cdd6c482 | 1779 | list_del_event(event, ctx); |
39a43640 PZ |
1780 | |
1781 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1782 | ctx->is_active = 0; |
39a43640 PZ |
1783 | if (ctx->task) { |
1784 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1785 | cpuctx->task_ctx = NULL; | |
1786 | } | |
64ce3126 | 1787 | } |
0793a61d TG |
1788 | } |
1789 | ||
0793a61d | 1790 | /* |
cdd6c482 | 1791 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1792 | * |
cdd6c482 IM |
1793 | * If event->ctx is a cloned context, callers must make sure that |
1794 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1795 | * remains valid. This is OK when called from perf_release since |
1796 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1797 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1798 | * context has been detached from its task. |
0793a61d | 1799 | */ |
46ce0fe9 | 1800 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1801 | { |
fae3fde6 | 1802 | lockdep_assert_held(&event->ctx->mutex); |
fe4b04fa | 1803 | |
0017960f | 1804 | event_function_call(event, __perf_remove_from_context, |
fae3fde6 | 1805 | (void *)(unsigned long)detach_group); |
0793a61d TG |
1806 | } |
1807 | ||
d859e29f | 1808 | /* |
cdd6c482 | 1809 | * Cross CPU call to disable a performance event |
d859e29f | 1810 | */ |
fae3fde6 PZ |
1811 | static void __perf_event_disable(struct perf_event *event, |
1812 | struct perf_cpu_context *cpuctx, | |
1813 | struct perf_event_context *ctx, | |
1814 | void *info) | |
7b648018 | 1815 | { |
fae3fde6 PZ |
1816 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1817 | return; | |
7b648018 | 1818 | |
fae3fde6 PZ |
1819 | update_context_time(ctx); |
1820 | update_cgrp_time_from_event(event); | |
1821 | update_group_times(event); | |
1822 | if (event == event->group_leader) | |
1823 | group_sched_out(event, cpuctx, ctx); | |
1824 | else | |
1825 | event_sched_out(event, cpuctx, ctx); | |
1826 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1827 | } |
1828 | ||
d859e29f | 1829 | /* |
cdd6c482 | 1830 | * Disable a event. |
c93f7669 | 1831 | * |
cdd6c482 IM |
1832 | * If event->ctx is a cloned context, callers must make sure that |
1833 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1834 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1835 | * perf_event_for_each_child or perf_event_for_each because they |
1836 | * hold the top-level event's child_mutex, so any descendant that | |
1837 | * goes to exit will block in sync_child_event. | |
1838 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1839 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1840 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1841 | */ |
f63a8daa | 1842 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1843 | { |
cdd6c482 | 1844 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1845 | |
e625cce1 | 1846 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1847 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1848 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1849 | return; |
53cfbf59 | 1850 | } |
e625cce1 | 1851 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1852 | |
fae3fde6 PZ |
1853 | event_function_call(event, __perf_event_disable, NULL); |
1854 | } | |
1855 | ||
1856 | void perf_event_disable_local(struct perf_event *event) | |
1857 | { | |
1858 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1859 | } |
f63a8daa PZ |
1860 | |
1861 | /* | |
1862 | * Strictly speaking kernel users cannot create groups and therefore this | |
1863 | * interface does not need the perf_event_ctx_lock() magic. | |
1864 | */ | |
1865 | void perf_event_disable(struct perf_event *event) | |
1866 | { | |
1867 | struct perf_event_context *ctx; | |
1868 | ||
1869 | ctx = perf_event_ctx_lock(event); | |
1870 | _perf_event_disable(event); | |
1871 | perf_event_ctx_unlock(event, ctx); | |
1872 | } | |
dcfce4a0 | 1873 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1874 | |
e5d1367f SE |
1875 | static void perf_set_shadow_time(struct perf_event *event, |
1876 | struct perf_event_context *ctx, | |
1877 | u64 tstamp) | |
1878 | { | |
1879 | /* | |
1880 | * use the correct time source for the time snapshot | |
1881 | * | |
1882 | * We could get by without this by leveraging the | |
1883 | * fact that to get to this function, the caller | |
1884 | * has most likely already called update_context_time() | |
1885 | * and update_cgrp_time_xx() and thus both timestamp | |
1886 | * are identical (or very close). Given that tstamp is, | |
1887 | * already adjusted for cgroup, we could say that: | |
1888 | * tstamp - ctx->timestamp | |
1889 | * is equivalent to | |
1890 | * tstamp - cgrp->timestamp. | |
1891 | * | |
1892 | * Then, in perf_output_read(), the calculation would | |
1893 | * work with no changes because: | |
1894 | * - event is guaranteed scheduled in | |
1895 | * - no scheduled out in between | |
1896 | * - thus the timestamp would be the same | |
1897 | * | |
1898 | * But this is a bit hairy. | |
1899 | * | |
1900 | * So instead, we have an explicit cgroup call to remain | |
1901 | * within the time time source all along. We believe it | |
1902 | * is cleaner and simpler to understand. | |
1903 | */ | |
1904 | if (is_cgroup_event(event)) | |
1905 | perf_cgroup_set_shadow_time(event, tstamp); | |
1906 | else | |
1907 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1908 | } | |
1909 | ||
4fe757dd PZ |
1910 | #define MAX_INTERRUPTS (~0ULL) |
1911 | ||
1912 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1913 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1914 | |
235c7fc7 | 1915 | static int |
9ffcfa6f | 1916 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1917 | struct perf_cpu_context *cpuctx, |
6e37738a | 1918 | struct perf_event_context *ctx) |
235c7fc7 | 1919 | { |
4158755d | 1920 | u64 tstamp = perf_event_time(event); |
44377277 | 1921 | int ret = 0; |
4158755d | 1922 | |
63342411 PZ |
1923 | lockdep_assert_held(&ctx->lock); |
1924 | ||
cdd6c482 | 1925 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1926 | return 0; |
1927 | ||
cdd6c482 | 1928 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1929 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1930 | |
1931 | /* | |
1932 | * Unthrottle events, since we scheduled we might have missed several | |
1933 | * ticks already, also for a heavily scheduling task there is little | |
1934 | * guarantee it'll get a tick in a timely manner. | |
1935 | */ | |
1936 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1937 | perf_log_throttle(event, 1); | |
1938 | event->hw.interrupts = 0; | |
1939 | } | |
1940 | ||
235c7fc7 IM |
1941 | /* |
1942 | * The new state must be visible before we turn it on in the hardware: | |
1943 | */ | |
1944 | smp_wmb(); | |
1945 | ||
44377277 AS |
1946 | perf_pmu_disable(event->pmu); |
1947 | ||
72f669c0 SL |
1948 | perf_set_shadow_time(event, ctx, tstamp); |
1949 | ||
ec0d7729 AS |
1950 | perf_log_itrace_start(event); |
1951 | ||
a4eaf7f1 | 1952 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1953 | event->state = PERF_EVENT_STATE_INACTIVE; |
1954 | event->oncpu = -1; | |
44377277 AS |
1955 | ret = -EAGAIN; |
1956 | goto out; | |
235c7fc7 IM |
1957 | } |
1958 | ||
00a2916f PZ |
1959 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1960 | ||
cdd6c482 | 1961 | if (!is_software_event(event)) |
3b6f9e5c | 1962 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1963 | if (!ctx->nr_active++) |
1964 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1965 | if (event->attr.freq && event->attr.sample_freq) |
1966 | ctx->nr_freq++; | |
235c7fc7 | 1967 | |
cdd6c482 | 1968 | if (event->attr.exclusive) |
3b6f9e5c PM |
1969 | cpuctx->exclusive = 1; |
1970 | ||
fadfe7be JO |
1971 | if (is_orphaned_child(event)) |
1972 | schedule_orphans_remove(ctx); | |
1973 | ||
44377277 AS |
1974 | out: |
1975 | perf_pmu_enable(event->pmu); | |
1976 | ||
1977 | return ret; | |
235c7fc7 IM |
1978 | } |
1979 | ||
6751b71e | 1980 | static int |
cdd6c482 | 1981 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1982 | struct perf_cpu_context *cpuctx, |
6e37738a | 1983 | struct perf_event_context *ctx) |
6751b71e | 1984 | { |
6bde9b6c | 1985 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1986 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1987 | u64 now = ctx->time; |
1988 | bool simulate = false; | |
6751b71e | 1989 | |
cdd6c482 | 1990 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1991 | return 0; |
1992 | ||
fbbe0701 | 1993 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1994 | |
9ffcfa6f | 1995 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1996 | pmu->cancel_txn(pmu); |
272325c4 | 1997 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1998 | return -EAGAIN; |
90151c35 | 1999 | } |
6751b71e PM |
2000 | |
2001 | /* | |
2002 | * Schedule in siblings as one group (if any): | |
2003 | */ | |
cdd6c482 | 2004 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 2005 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 2006 | partial_group = event; |
6751b71e PM |
2007 | goto group_error; |
2008 | } | |
2009 | } | |
2010 | ||
9ffcfa6f | 2011 | if (!pmu->commit_txn(pmu)) |
6e85158c | 2012 | return 0; |
9ffcfa6f | 2013 | |
6751b71e PM |
2014 | group_error: |
2015 | /* | |
2016 | * Groups can be scheduled in as one unit only, so undo any | |
2017 | * partial group before returning: | |
d7842da4 SE |
2018 | * The events up to the failed event are scheduled out normally, |
2019 | * tstamp_stopped will be updated. | |
2020 | * | |
2021 | * The failed events and the remaining siblings need to have | |
2022 | * their timings updated as if they had gone thru event_sched_in() | |
2023 | * and event_sched_out(). This is required to get consistent timings | |
2024 | * across the group. This also takes care of the case where the group | |
2025 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2026 | * the time the event was actually stopped, such that time delta | |
2027 | * calculation in update_event_times() is correct. | |
6751b71e | 2028 | */ |
cdd6c482 IM |
2029 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2030 | if (event == partial_group) | |
d7842da4 SE |
2031 | simulate = true; |
2032 | ||
2033 | if (simulate) { | |
2034 | event->tstamp_running += now - event->tstamp_stopped; | |
2035 | event->tstamp_stopped = now; | |
2036 | } else { | |
2037 | event_sched_out(event, cpuctx, ctx); | |
2038 | } | |
6751b71e | 2039 | } |
9ffcfa6f | 2040 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2041 | |
ad5133b7 | 2042 | pmu->cancel_txn(pmu); |
90151c35 | 2043 | |
272325c4 | 2044 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2045 | |
6751b71e PM |
2046 | return -EAGAIN; |
2047 | } | |
2048 | ||
3b6f9e5c | 2049 | /* |
cdd6c482 | 2050 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2051 | */ |
cdd6c482 | 2052 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2053 | struct perf_cpu_context *cpuctx, |
2054 | int can_add_hw) | |
2055 | { | |
2056 | /* | |
cdd6c482 | 2057 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2058 | */ |
d6f962b5 | 2059 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2060 | return 1; |
2061 | /* | |
2062 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2063 | * events can go on. |
3b6f9e5c PM |
2064 | */ |
2065 | if (cpuctx->exclusive) | |
2066 | return 0; | |
2067 | /* | |
2068 | * If this group is exclusive and there are already | |
cdd6c482 | 2069 | * events on the CPU, it can't go on. |
3b6f9e5c | 2070 | */ |
cdd6c482 | 2071 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2072 | return 0; |
2073 | /* | |
2074 | * Otherwise, try to add it if all previous groups were able | |
2075 | * to go on. | |
2076 | */ | |
2077 | return can_add_hw; | |
2078 | } | |
2079 | ||
cdd6c482 IM |
2080 | static void add_event_to_ctx(struct perf_event *event, |
2081 | struct perf_event_context *ctx) | |
53cfbf59 | 2082 | { |
4158755d SE |
2083 | u64 tstamp = perf_event_time(event); |
2084 | ||
cdd6c482 | 2085 | list_add_event(event, ctx); |
8a49542c | 2086 | perf_group_attach(event); |
4158755d SE |
2087 | event->tstamp_enabled = tstamp; |
2088 | event->tstamp_running = tstamp; | |
2089 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2090 | } |
2091 | ||
3e349507 PZ |
2092 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2093 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2094 | static void |
2095 | ctx_sched_in(struct perf_event_context *ctx, | |
2096 | struct perf_cpu_context *cpuctx, | |
2097 | enum event_type_t event_type, | |
2098 | struct task_struct *task); | |
fe4b04fa | 2099 | |
dce5855b PZ |
2100 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2101 | struct perf_event_context *ctx, | |
2102 | struct task_struct *task) | |
2103 | { | |
2104 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2105 | if (ctx) | |
2106 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2107 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2108 | if (ctx) | |
2109 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2110 | } | |
2111 | ||
3e349507 PZ |
2112 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2113 | struct perf_event_context *task_ctx) | |
2114 | { | |
2115 | perf_pmu_disable(cpuctx->ctx.pmu); | |
2116 | if (task_ctx) | |
2117 | task_ctx_sched_out(cpuctx, task_ctx); | |
2118 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2119 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2120 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2121 | } | |
2122 | ||
0793a61d | 2123 | /* |
cdd6c482 | 2124 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2125 | * |
2126 | * Must be called with ctx->mutex held | |
0793a61d | 2127 | */ |
fe4b04fa | 2128 | static int __perf_install_in_context(void *info) |
0793a61d | 2129 | { |
39a43640 | 2130 | struct perf_event_context *ctx = info; |
108b02cf | 2131 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2132 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
2c29ef0f | 2133 | |
39a43640 PZ |
2134 | if (ctx->task) { |
2135 | /* | |
2136 | * If we hit the 'wrong' task, we've since scheduled and | |
2137 | * everything should be sorted, nothing to do! | |
2138 | */ | |
2139 | if (ctx->task != current) | |
2140 | return 0; | |
b58f6b0d | 2141 | |
39a43640 PZ |
2142 | /* |
2143 | * If task_ctx is set, it had better be to us. | |
2144 | */ | |
2145 | WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx); | |
b58f6b0d PZ |
2146 | task_ctx = ctx; |
2147 | } | |
2148 | ||
39a43640 PZ |
2149 | perf_ctx_lock(cpuctx, task_ctx); |
2150 | ctx_resched(cpuctx, task_ctx); | |
2c29ef0f | 2151 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2152 | |
2153 | return 0; | |
0793a61d TG |
2154 | } |
2155 | ||
2156 | /* | |
cdd6c482 | 2157 | * Attach a performance event to a context |
0793a61d TG |
2158 | */ |
2159 | static void | |
cdd6c482 IM |
2160 | perf_install_in_context(struct perf_event_context *ctx, |
2161 | struct perf_event *event, | |
0793a61d TG |
2162 | int cpu) |
2163 | { | |
39a43640 PZ |
2164 | struct task_struct *task = NULL; |
2165 | ||
fe4b04fa PZ |
2166 | lockdep_assert_held(&ctx->mutex); |
2167 | ||
c3f00c70 | 2168 | event->ctx = ctx; |
0cda4c02 YZ |
2169 | if (event->cpu != -1) |
2170 | event->cpu = cpu; | |
c3f00c70 | 2171 | |
39a43640 PZ |
2172 | /* |
2173 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2174 | * to be set in case this is the nr_events 0 -> 1 transition. | |
2175 | * | |
2176 | * So what we do is we add the event to the list here, which will allow | |
2177 | * a future context switch to DTRT and then send a racy IPI. If the IPI | |
2178 | * fails to hit the right task, this means a context switch must have | |
2179 | * happened and that will have taken care of business. | |
2180 | */ | |
2181 | raw_spin_lock_irq(&ctx->lock); | |
2182 | update_context_time(ctx); | |
2183 | /* | |
2184 | * Update cgrp time only if current cgrp matches event->cgrp. | |
2185 | * Must be done before calling add_event_to_ctx(). | |
2186 | */ | |
2187 | update_cgrp_time_from_event(event); | |
2188 | add_event_to_ctx(event, ctx); | |
2189 | task = ctx->task; | |
2190 | raw_spin_unlock_irq(&ctx->lock); | |
2191 | ||
2192 | if (task) | |
2193 | task_function_call(task, __perf_install_in_context, ctx); | |
2194 | else | |
2195 | cpu_function_call(cpu, __perf_install_in_context, ctx); | |
0793a61d TG |
2196 | } |
2197 | ||
fa289bec | 2198 | /* |
cdd6c482 | 2199 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2200 | * Enabling the leader of a group effectively enables all |
2201 | * the group members that aren't explicitly disabled, so we | |
2202 | * have to update their ->tstamp_enabled also. | |
2203 | * Note: this works for group members as well as group leaders | |
2204 | * since the non-leader members' sibling_lists will be empty. | |
2205 | */ | |
1d9b482e | 2206 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2207 | { |
cdd6c482 | 2208 | struct perf_event *sub; |
4158755d | 2209 | u64 tstamp = perf_event_time(event); |
fa289bec | 2210 | |
cdd6c482 | 2211 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2212 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2213 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2214 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2215 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2216 | } |
fa289bec PM |
2217 | } |
2218 | ||
d859e29f | 2219 | /* |
cdd6c482 | 2220 | * Cross CPU call to enable a performance event |
d859e29f | 2221 | */ |
fae3fde6 PZ |
2222 | static void __perf_event_enable(struct perf_event *event, |
2223 | struct perf_cpu_context *cpuctx, | |
2224 | struct perf_event_context *ctx, | |
2225 | void *info) | |
04289bb9 | 2226 | { |
cdd6c482 | 2227 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2228 | struct perf_event_context *task_ctx; |
d859e29f | 2229 | |
cdd6c482 | 2230 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
fae3fde6 | 2231 | return; |
e5d1367f | 2232 | |
fae3fde6 | 2233 | update_context_time(ctx); |
1d9b482e | 2234 | __perf_event_mark_enabled(event); |
04289bb9 | 2235 | |
fae3fde6 PZ |
2236 | if (!ctx->is_active) |
2237 | return; | |
2238 | ||
e5d1367f | 2239 | if (!event_filter_match(event)) { |
fae3fde6 PZ |
2240 | if (is_cgroup_event(event)) { |
2241 | perf_cgroup_set_timestamp(current, ctx); // XXX ? | |
e5d1367f | 2242 | perf_cgroup_defer_enabled(event); |
fae3fde6 PZ |
2243 | } |
2244 | return; | |
e5d1367f | 2245 | } |
f4c4176f | 2246 | |
04289bb9 | 2247 | /* |
cdd6c482 | 2248 | * If the event is in a group and isn't the group leader, |
d859e29f | 2249 | * then don't put it on unless the group is on. |
04289bb9 | 2250 | */ |
cdd6c482 | 2251 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
fae3fde6 | 2252 | return; |
3b6f9e5c | 2253 | |
fae3fde6 PZ |
2254 | task_ctx = cpuctx->task_ctx; |
2255 | if (ctx->task) | |
2256 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2257 | |
fae3fde6 | 2258 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2259 | } |
2260 | ||
d859e29f | 2261 | /* |
cdd6c482 | 2262 | * Enable a event. |
c93f7669 | 2263 | * |
cdd6c482 IM |
2264 | * If event->ctx is a cloned context, callers must make sure that |
2265 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2266 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2267 | * perf_event_for_each_child or perf_event_for_each as described |
2268 | * for perf_event_disable. | |
d859e29f | 2269 | */ |
f63a8daa | 2270 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2271 | { |
cdd6c482 | 2272 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2273 | |
7b648018 PZ |
2274 | raw_spin_lock_irq(&ctx->lock); |
2275 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
2276 | raw_spin_unlock_irq(&ctx->lock); | |
d859e29f PM |
2277 | return; |
2278 | } | |
2279 | ||
d859e29f | 2280 | /* |
cdd6c482 | 2281 | * If the event is in error state, clear that first. |
7b648018 PZ |
2282 | * |
2283 | * That way, if we see the event in error state below, we know that it | |
2284 | * has gone back into error state, as distinct from the task having | |
2285 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2286 | */ |
cdd6c482 IM |
2287 | if (event->state == PERF_EVENT_STATE_ERROR) |
2288 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2289 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2290 | |
fae3fde6 | 2291 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2292 | } |
f63a8daa PZ |
2293 | |
2294 | /* | |
2295 | * See perf_event_disable(); | |
2296 | */ | |
2297 | void perf_event_enable(struct perf_event *event) | |
2298 | { | |
2299 | struct perf_event_context *ctx; | |
2300 | ||
2301 | ctx = perf_event_ctx_lock(event); | |
2302 | _perf_event_enable(event); | |
2303 | perf_event_ctx_unlock(event, ctx); | |
2304 | } | |
dcfce4a0 | 2305 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2306 | |
f63a8daa | 2307 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2308 | { |
2023b359 | 2309 | /* |
cdd6c482 | 2310 | * not supported on inherited events |
2023b359 | 2311 | */ |
2e939d1d | 2312 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2313 | return -EINVAL; |
2314 | ||
cdd6c482 | 2315 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2316 | _perf_event_enable(event); |
2023b359 PZ |
2317 | |
2318 | return 0; | |
79f14641 | 2319 | } |
f63a8daa PZ |
2320 | |
2321 | /* | |
2322 | * See perf_event_disable() | |
2323 | */ | |
2324 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2325 | { | |
2326 | struct perf_event_context *ctx; | |
2327 | int ret; | |
2328 | ||
2329 | ctx = perf_event_ctx_lock(event); | |
2330 | ret = _perf_event_refresh(event, refresh); | |
2331 | perf_event_ctx_unlock(event, ctx); | |
2332 | ||
2333 | return ret; | |
2334 | } | |
26ca5c11 | 2335 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2336 | |
5b0311e1 FW |
2337 | static void ctx_sched_out(struct perf_event_context *ctx, |
2338 | struct perf_cpu_context *cpuctx, | |
2339 | enum event_type_t event_type) | |
235c7fc7 | 2340 | { |
db24d33e | 2341 | int is_active = ctx->is_active; |
c994d613 PZ |
2342 | struct perf_event *event; |
2343 | ||
2344 | lockdep_assert_held(&ctx->lock); | |
235c7fc7 | 2345 | |
39a43640 PZ |
2346 | if (likely(!ctx->nr_events)) { |
2347 | /* | |
2348 | * See __perf_remove_from_context(). | |
2349 | */ | |
2350 | WARN_ON_ONCE(ctx->is_active); | |
2351 | if (ctx->task) | |
2352 | WARN_ON_ONCE(cpuctx->task_ctx); | |
2353 | return; | |
2354 | } | |
2355 | ||
db24d33e | 2356 | ctx->is_active &= ~event_type; |
63e30d3e PZ |
2357 | if (ctx->task) { |
2358 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2359 | if (!ctx->is_active) | |
2360 | cpuctx->task_ctx = NULL; | |
2361 | } | |
2362 | ||
4af4998b | 2363 | update_context_time(ctx); |
e5d1367f | 2364 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2365 | if (!ctx->nr_active) |
facc4307 | 2366 | return; |
5b0311e1 | 2367 | |
075e0b00 | 2368 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2369 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2370 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2371 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2372 | } |
889ff015 | 2373 | |
db24d33e | 2374 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2375 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2376 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2377 | } |
1b9a644f | 2378 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2379 | } |
2380 | ||
564c2b21 | 2381 | /* |
5a3126d4 PZ |
2382 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2383 | * cloned from the same version of the same context. | |
2384 | * | |
2385 | * Equivalence is measured using a generation number in the context that is | |
2386 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2387 | * and list_del_event(). | |
564c2b21 | 2388 | */ |
cdd6c482 IM |
2389 | static int context_equiv(struct perf_event_context *ctx1, |
2390 | struct perf_event_context *ctx2) | |
564c2b21 | 2391 | { |
211de6eb PZ |
2392 | lockdep_assert_held(&ctx1->lock); |
2393 | lockdep_assert_held(&ctx2->lock); | |
2394 | ||
5a3126d4 PZ |
2395 | /* Pinning disables the swap optimization */ |
2396 | if (ctx1->pin_count || ctx2->pin_count) | |
2397 | return 0; | |
2398 | ||
2399 | /* If ctx1 is the parent of ctx2 */ | |
2400 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2401 | return 1; | |
2402 | ||
2403 | /* If ctx2 is the parent of ctx1 */ | |
2404 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2405 | return 1; | |
2406 | ||
2407 | /* | |
2408 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2409 | * hierarchy, see perf_event_init_context(). | |
2410 | */ | |
2411 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2412 | ctx1->parent_gen == ctx2->parent_gen) | |
2413 | return 1; | |
2414 | ||
2415 | /* Unmatched */ | |
2416 | return 0; | |
564c2b21 PM |
2417 | } |
2418 | ||
cdd6c482 IM |
2419 | static void __perf_event_sync_stat(struct perf_event *event, |
2420 | struct perf_event *next_event) | |
bfbd3381 PZ |
2421 | { |
2422 | u64 value; | |
2423 | ||
cdd6c482 | 2424 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2425 | return; |
2426 | ||
2427 | /* | |
cdd6c482 | 2428 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2429 | * because we're in the middle of a context switch and have IRQs |
2430 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2431 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2432 | * don't need to use it. |
2433 | */ | |
cdd6c482 IM |
2434 | switch (event->state) { |
2435 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2436 | event->pmu->read(event); |
2437 | /* fall-through */ | |
bfbd3381 | 2438 | |
cdd6c482 IM |
2439 | case PERF_EVENT_STATE_INACTIVE: |
2440 | update_event_times(event); | |
bfbd3381 PZ |
2441 | break; |
2442 | ||
2443 | default: | |
2444 | break; | |
2445 | } | |
2446 | ||
2447 | /* | |
cdd6c482 | 2448 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2449 | * values when we flip the contexts. |
2450 | */ | |
e7850595 PZ |
2451 | value = local64_read(&next_event->count); |
2452 | value = local64_xchg(&event->count, value); | |
2453 | local64_set(&next_event->count, value); | |
bfbd3381 | 2454 | |
cdd6c482 IM |
2455 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2456 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2457 | |
bfbd3381 | 2458 | /* |
19d2e755 | 2459 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2460 | */ |
cdd6c482 IM |
2461 | perf_event_update_userpage(event); |
2462 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2463 | } |
2464 | ||
cdd6c482 IM |
2465 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2466 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2467 | { |
cdd6c482 | 2468 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2469 | |
2470 | if (!ctx->nr_stat) | |
2471 | return; | |
2472 | ||
02ffdbc8 PZ |
2473 | update_context_time(ctx); |
2474 | ||
cdd6c482 IM |
2475 | event = list_first_entry(&ctx->event_list, |
2476 | struct perf_event, event_entry); | |
bfbd3381 | 2477 | |
cdd6c482 IM |
2478 | next_event = list_first_entry(&next_ctx->event_list, |
2479 | struct perf_event, event_entry); | |
bfbd3381 | 2480 | |
cdd6c482 IM |
2481 | while (&event->event_entry != &ctx->event_list && |
2482 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2483 | |
cdd6c482 | 2484 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2485 | |
cdd6c482 IM |
2486 | event = list_next_entry(event, event_entry); |
2487 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2488 | } |
2489 | } | |
2490 | ||
fe4b04fa PZ |
2491 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2492 | struct task_struct *next) | |
0793a61d | 2493 | { |
8dc85d54 | 2494 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2495 | struct perf_event_context *next_ctx; |
5a3126d4 | 2496 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2497 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2498 | int do_switch = 1; |
0793a61d | 2499 | |
108b02cf PZ |
2500 | if (likely(!ctx)) |
2501 | return; | |
10989fb2 | 2502 | |
108b02cf PZ |
2503 | cpuctx = __get_cpu_context(ctx); |
2504 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2505 | return; |
2506 | ||
c93f7669 | 2507 | rcu_read_lock(); |
8dc85d54 | 2508 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2509 | if (!next_ctx) |
2510 | goto unlock; | |
2511 | ||
2512 | parent = rcu_dereference(ctx->parent_ctx); | |
2513 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2514 | ||
2515 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2516 | if (!parent && !next_parent) |
5a3126d4 PZ |
2517 | goto unlock; |
2518 | ||
2519 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2520 | /* |
2521 | * Looks like the two contexts are clones, so we might be | |
2522 | * able to optimize the context switch. We lock both | |
2523 | * contexts and check that they are clones under the | |
2524 | * lock (including re-checking that neither has been | |
2525 | * uncloned in the meantime). It doesn't matter which | |
2526 | * order we take the locks because no other cpu could | |
2527 | * be trying to lock both of these tasks. | |
2528 | */ | |
e625cce1 TG |
2529 | raw_spin_lock(&ctx->lock); |
2530 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2531 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2532 | /* |
2533 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2534 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2535 | */ |
8dc85d54 PZ |
2536 | task->perf_event_ctxp[ctxn] = next_ctx; |
2537 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2538 | ctx->task = next; |
2539 | next_ctx->task = task; | |
5a158c3c YZ |
2540 | |
2541 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2542 | ||
c93f7669 | 2543 | do_switch = 0; |
bfbd3381 | 2544 | |
cdd6c482 | 2545 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2546 | } |
e625cce1 TG |
2547 | raw_spin_unlock(&next_ctx->lock); |
2548 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2549 | } |
5a3126d4 | 2550 | unlock: |
c93f7669 | 2551 | rcu_read_unlock(); |
564c2b21 | 2552 | |
c93f7669 | 2553 | if (do_switch) { |
facc4307 | 2554 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2555 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2556 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2557 | } |
0793a61d TG |
2558 | } |
2559 | ||
ba532500 YZ |
2560 | void perf_sched_cb_dec(struct pmu *pmu) |
2561 | { | |
2562 | this_cpu_dec(perf_sched_cb_usages); | |
2563 | } | |
2564 | ||
2565 | void perf_sched_cb_inc(struct pmu *pmu) | |
2566 | { | |
2567 | this_cpu_inc(perf_sched_cb_usages); | |
2568 | } | |
2569 | ||
2570 | /* | |
2571 | * This function provides the context switch callback to the lower code | |
2572 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2573 | */ | |
2574 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2575 | struct task_struct *next, | |
2576 | bool sched_in) | |
2577 | { | |
2578 | struct perf_cpu_context *cpuctx; | |
2579 | struct pmu *pmu; | |
2580 | unsigned long flags; | |
2581 | ||
2582 | if (prev == next) | |
2583 | return; | |
2584 | ||
2585 | local_irq_save(flags); | |
2586 | ||
2587 | rcu_read_lock(); | |
2588 | ||
2589 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2590 | if (pmu->sched_task) { | |
2591 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2592 | ||
2593 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2594 | ||
2595 | perf_pmu_disable(pmu); | |
2596 | ||
2597 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2598 | ||
2599 | perf_pmu_enable(pmu); | |
2600 | ||
2601 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2602 | } | |
2603 | } | |
2604 | ||
2605 | rcu_read_unlock(); | |
2606 | ||
2607 | local_irq_restore(flags); | |
2608 | } | |
2609 | ||
45ac1403 AH |
2610 | static void perf_event_switch(struct task_struct *task, |
2611 | struct task_struct *next_prev, bool sched_in); | |
2612 | ||
8dc85d54 PZ |
2613 | #define for_each_task_context_nr(ctxn) \ |
2614 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2615 | ||
2616 | /* | |
2617 | * Called from scheduler to remove the events of the current task, | |
2618 | * with interrupts disabled. | |
2619 | * | |
2620 | * We stop each event and update the event value in event->count. | |
2621 | * | |
2622 | * This does not protect us against NMI, but disable() | |
2623 | * sets the disabled bit in the control field of event _before_ | |
2624 | * accessing the event control register. If a NMI hits, then it will | |
2625 | * not restart the event. | |
2626 | */ | |
ab0cce56 JO |
2627 | void __perf_event_task_sched_out(struct task_struct *task, |
2628 | struct task_struct *next) | |
8dc85d54 PZ |
2629 | { |
2630 | int ctxn; | |
2631 | ||
ba532500 YZ |
2632 | if (__this_cpu_read(perf_sched_cb_usages)) |
2633 | perf_pmu_sched_task(task, next, false); | |
2634 | ||
45ac1403 AH |
2635 | if (atomic_read(&nr_switch_events)) |
2636 | perf_event_switch(task, next, false); | |
2637 | ||
8dc85d54 PZ |
2638 | for_each_task_context_nr(ctxn) |
2639 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2640 | |
2641 | /* | |
2642 | * if cgroup events exist on this CPU, then we need | |
2643 | * to check if we have to switch out PMU state. | |
2644 | * cgroup event are system-wide mode only | |
2645 | */ | |
4a32fea9 | 2646 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2647 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2648 | } |
2649 | ||
3e349507 PZ |
2650 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2651 | struct perf_event_context *ctx) | |
a08b159f | 2652 | { |
a63eaf34 PM |
2653 | if (!cpuctx->task_ctx) |
2654 | return; | |
012b84da IM |
2655 | |
2656 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2657 | return; | |
2658 | ||
04dc2dbb | 2659 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2660 | } |
2661 | ||
5b0311e1 FW |
2662 | /* |
2663 | * Called with IRQs disabled | |
2664 | */ | |
2665 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2666 | enum event_type_t event_type) | |
2667 | { | |
2668 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2669 | } |
2670 | ||
235c7fc7 | 2671 | static void |
5b0311e1 | 2672 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2673 | struct perf_cpu_context *cpuctx) |
0793a61d | 2674 | { |
cdd6c482 | 2675 | struct perf_event *event; |
0793a61d | 2676 | |
889ff015 FW |
2677 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2678 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2679 | continue; |
5632ab12 | 2680 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2681 | continue; |
2682 | ||
e5d1367f SE |
2683 | /* may need to reset tstamp_enabled */ |
2684 | if (is_cgroup_event(event)) | |
2685 | perf_cgroup_mark_enabled(event, ctx); | |
2686 | ||
8c9ed8e1 | 2687 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2688 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2689 | |
2690 | /* | |
2691 | * If this pinned group hasn't been scheduled, | |
2692 | * put it in error state. | |
2693 | */ | |
cdd6c482 IM |
2694 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2695 | update_group_times(event); | |
2696 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2697 | } |
3b6f9e5c | 2698 | } |
5b0311e1 FW |
2699 | } |
2700 | ||
2701 | static void | |
2702 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2703 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2704 | { |
2705 | struct perf_event *event; | |
2706 | int can_add_hw = 1; | |
3b6f9e5c | 2707 | |
889ff015 FW |
2708 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2709 | /* Ignore events in OFF or ERROR state */ | |
2710 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2711 | continue; |
04289bb9 IM |
2712 | /* |
2713 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2714 | * of events: |
04289bb9 | 2715 | */ |
5632ab12 | 2716 | if (!event_filter_match(event)) |
0793a61d TG |
2717 | continue; |
2718 | ||
e5d1367f SE |
2719 | /* may need to reset tstamp_enabled */ |
2720 | if (is_cgroup_event(event)) | |
2721 | perf_cgroup_mark_enabled(event, ctx); | |
2722 | ||
9ed6060d | 2723 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2724 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2725 | can_add_hw = 0; |
9ed6060d | 2726 | } |
0793a61d | 2727 | } |
5b0311e1 FW |
2728 | } |
2729 | ||
2730 | static void | |
2731 | ctx_sched_in(struct perf_event_context *ctx, | |
2732 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2733 | enum event_type_t event_type, |
2734 | struct task_struct *task) | |
5b0311e1 | 2735 | { |
db24d33e | 2736 | int is_active = ctx->is_active; |
c994d613 PZ |
2737 | u64 now; |
2738 | ||
2739 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2740 | |
39a43640 PZ |
2741 | if (likely(!ctx->nr_events)) |
2742 | return; | |
2743 | ||
db24d33e | 2744 | ctx->is_active |= event_type; |
63e30d3e PZ |
2745 | if (ctx->task) { |
2746 | if (!is_active) | |
2747 | cpuctx->task_ctx = ctx; | |
2748 | else | |
2749 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2750 | } | |
2751 | ||
e5d1367f SE |
2752 | now = perf_clock(); |
2753 | ctx->timestamp = now; | |
3f7cce3c | 2754 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2755 | /* |
2756 | * First go through the list and put on any pinned groups | |
2757 | * in order to give them the best chance of going on. | |
2758 | */ | |
db24d33e | 2759 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2760 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2761 | |
2762 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2763 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2764 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2765 | } |
2766 | ||
329c0e01 | 2767 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2768 | enum event_type_t event_type, |
2769 | struct task_struct *task) | |
329c0e01 FW |
2770 | { |
2771 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2772 | ||
e5d1367f | 2773 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2774 | } |
2775 | ||
e5d1367f SE |
2776 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2777 | struct task_struct *task) | |
235c7fc7 | 2778 | { |
108b02cf | 2779 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2780 | |
108b02cf | 2781 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2782 | if (cpuctx->task_ctx == ctx) |
2783 | return; | |
2784 | ||
facc4307 | 2785 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2786 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2787 | /* |
2788 | * We want to keep the following priority order: | |
2789 | * cpu pinned (that don't need to move), task pinned, | |
2790 | * cpu flexible, task flexible. | |
2791 | */ | |
2792 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2793 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2794 | perf_pmu_enable(ctx->pmu); |
2795 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2796 | } |
2797 | ||
8dc85d54 PZ |
2798 | /* |
2799 | * Called from scheduler to add the events of the current task | |
2800 | * with interrupts disabled. | |
2801 | * | |
2802 | * We restore the event value and then enable it. | |
2803 | * | |
2804 | * This does not protect us against NMI, but enable() | |
2805 | * sets the enabled bit in the control field of event _before_ | |
2806 | * accessing the event control register. If a NMI hits, then it will | |
2807 | * keep the event running. | |
2808 | */ | |
ab0cce56 JO |
2809 | void __perf_event_task_sched_in(struct task_struct *prev, |
2810 | struct task_struct *task) | |
8dc85d54 PZ |
2811 | { |
2812 | struct perf_event_context *ctx; | |
2813 | int ctxn; | |
2814 | ||
7e41d177 PZ |
2815 | /* |
2816 | * If cgroup events exist on this CPU, then we need to check if we have | |
2817 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2818 | * | |
2819 | * Since cgroup events are CPU events, we must schedule these in before | |
2820 | * we schedule in the task events. | |
2821 | */ | |
2822 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2823 | perf_cgroup_sched_in(prev, task); | |
2824 | ||
8dc85d54 PZ |
2825 | for_each_task_context_nr(ctxn) { |
2826 | ctx = task->perf_event_ctxp[ctxn]; | |
2827 | if (likely(!ctx)) | |
2828 | continue; | |
2829 | ||
e5d1367f | 2830 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2831 | } |
d010b332 | 2832 | |
45ac1403 AH |
2833 | if (atomic_read(&nr_switch_events)) |
2834 | perf_event_switch(task, prev, true); | |
2835 | ||
ba532500 YZ |
2836 | if (__this_cpu_read(perf_sched_cb_usages)) |
2837 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2838 | } |
2839 | ||
abd50713 PZ |
2840 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2841 | { | |
2842 | u64 frequency = event->attr.sample_freq; | |
2843 | u64 sec = NSEC_PER_SEC; | |
2844 | u64 divisor, dividend; | |
2845 | ||
2846 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2847 | ||
2848 | count_fls = fls64(count); | |
2849 | nsec_fls = fls64(nsec); | |
2850 | frequency_fls = fls64(frequency); | |
2851 | sec_fls = 30; | |
2852 | ||
2853 | /* | |
2854 | * We got @count in @nsec, with a target of sample_freq HZ | |
2855 | * the target period becomes: | |
2856 | * | |
2857 | * @count * 10^9 | |
2858 | * period = ------------------- | |
2859 | * @nsec * sample_freq | |
2860 | * | |
2861 | */ | |
2862 | ||
2863 | /* | |
2864 | * Reduce accuracy by one bit such that @a and @b converge | |
2865 | * to a similar magnitude. | |
2866 | */ | |
fe4b04fa | 2867 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2868 | do { \ |
2869 | if (a##_fls > b##_fls) { \ | |
2870 | a >>= 1; \ | |
2871 | a##_fls--; \ | |
2872 | } else { \ | |
2873 | b >>= 1; \ | |
2874 | b##_fls--; \ | |
2875 | } \ | |
2876 | } while (0) | |
2877 | ||
2878 | /* | |
2879 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2880 | * the other, so that finally we can do a u64/u64 division. | |
2881 | */ | |
2882 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2883 | REDUCE_FLS(nsec, frequency); | |
2884 | REDUCE_FLS(sec, count); | |
2885 | } | |
2886 | ||
2887 | if (count_fls + sec_fls > 64) { | |
2888 | divisor = nsec * frequency; | |
2889 | ||
2890 | while (count_fls + sec_fls > 64) { | |
2891 | REDUCE_FLS(count, sec); | |
2892 | divisor >>= 1; | |
2893 | } | |
2894 | ||
2895 | dividend = count * sec; | |
2896 | } else { | |
2897 | dividend = count * sec; | |
2898 | ||
2899 | while (nsec_fls + frequency_fls > 64) { | |
2900 | REDUCE_FLS(nsec, frequency); | |
2901 | dividend >>= 1; | |
2902 | } | |
2903 | ||
2904 | divisor = nsec * frequency; | |
2905 | } | |
2906 | ||
f6ab91ad PZ |
2907 | if (!divisor) |
2908 | return dividend; | |
2909 | ||
abd50713 PZ |
2910 | return div64_u64(dividend, divisor); |
2911 | } | |
2912 | ||
e050e3f0 SE |
2913 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2914 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2915 | ||
f39d47ff | 2916 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2917 | { |
cdd6c482 | 2918 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2919 | s64 period, sample_period; |
bd2b5b12 PZ |
2920 | s64 delta; |
2921 | ||
abd50713 | 2922 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2923 | |
2924 | delta = (s64)(period - hwc->sample_period); | |
2925 | delta = (delta + 7) / 8; /* low pass filter */ | |
2926 | ||
2927 | sample_period = hwc->sample_period + delta; | |
2928 | ||
2929 | if (!sample_period) | |
2930 | sample_period = 1; | |
2931 | ||
bd2b5b12 | 2932 | hwc->sample_period = sample_period; |
abd50713 | 2933 | |
e7850595 | 2934 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2935 | if (disable) |
2936 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2937 | ||
e7850595 | 2938 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2939 | |
2940 | if (disable) | |
2941 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2942 | } |
bd2b5b12 PZ |
2943 | } |
2944 | ||
e050e3f0 SE |
2945 | /* |
2946 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2947 | * events. At the same time, make sure, having freq events does not change | |
2948 | * the rate of unthrottling as that would introduce bias. | |
2949 | */ | |
2950 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2951 | int needs_unthr) | |
60db5e09 | 2952 | { |
cdd6c482 IM |
2953 | struct perf_event *event; |
2954 | struct hw_perf_event *hwc; | |
e050e3f0 | 2955 | u64 now, period = TICK_NSEC; |
abd50713 | 2956 | s64 delta; |
60db5e09 | 2957 | |
e050e3f0 SE |
2958 | /* |
2959 | * only need to iterate over all events iff: | |
2960 | * - context have events in frequency mode (needs freq adjust) | |
2961 | * - there are events to unthrottle on this cpu | |
2962 | */ | |
2963 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2964 | return; |
2965 | ||
e050e3f0 | 2966 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2967 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2968 | |
03541f8b | 2969 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2970 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2971 | continue; |
2972 | ||
5632ab12 | 2973 | if (!event_filter_match(event)) |
5d27c23d PZ |
2974 | continue; |
2975 | ||
44377277 AS |
2976 | perf_pmu_disable(event->pmu); |
2977 | ||
cdd6c482 | 2978 | hwc = &event->hw; |
6a24ed6c | 2979 | |
ae23bff1 | 2980 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2981 | hwc->interrupts = 0; |
cdd6c482 | 2982 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2983 | event->pmu->start(event, 0); |
a78ac325 PZ |
2984 | } |
2985 | ||
cdd6c482 | 2986 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2987 | goto next; |
60db5e09 | 2988 | |
e050e3f0 SE |
2989 | /* |
2990 | * stop the event and update event->count | |
2991 | */ | |
2992 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2993 | ||
e7850595 | 2994 | now = local64_read(&event->count); |
abd50713 PZ |
2995 | delta = now - hwc->freq_count_stamp; |
2996 | hwc->freq_count_stamp = now; | |
60db5e09 | 2997 | |
e050e3f0 SE |
2998 | /* |
2999 | * restart the event | |
3000 | * reload only if value has changed | |
f39d47ff SE |
3001 | * we have stopped the event so tell that |
3002 | * to perf_adjust_period() to avoid stopping it | |
3003 | * twice. | |
e050e3f0 | 3004 | */ |
abd50713 | 3005 | if (delta > 0) |
f39d47ff | 3006 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3007 | |
3008 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3009 | next: |
3010 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3011 | } |
e050e3f0 | 3012 | |
f39d47ff | 3013 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3014 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3015 | } |
3016 | ||
235c7fc7 | 3017 | /* |
cdd6c482 | 3018 | * Round-robin a context's events: |
235c7fc7 | 3019 | */ |
cdd6c482 | 3020 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3021 | { |
dddd3379 TG |
3022 | /* |
3023 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3024 | * disabled by the inheritance code. | |
3025 | */ | |
3026 | if (!ctx->rotate_disable) | |
3027 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3028 | } |
3029 | ||
9e630205 | 3030 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3031 | { |
8dc85d54 | 3032 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3033 | int rotate = 0; |
7fc23a53 | 3034 | |
b5ab4cd5 | 3035 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3036 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3037 | rotate = 1; | |
3038 | } | |
235c7fc7 | 3039 | |
8dc85d54 | 3040 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3041 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3042 | if (ctx->nr_events != ctx->nr_active) |
3043 | rotate = 1; | |
3044 | } | |
9717e6cd | 3045 | |
e050e3f0 | 3046 | if (!rotate) |
0f5a2601 PZ |
3047 | goto done; |
3048 | ||
facc4307 | 3049 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3050 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3051 | |
e050e3f0 SE |
3052 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3053 | if (ctx) | |
3054 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3055 | |
e050e3f0 SE |
3056 | rotate_ctx(&cpuctx->ctx); |
3057 | if (ctx) | |
3058 | rotate_ctx(ctx); | |
235c7fc7 | 3059 | |
e050e3f0 | 3060 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3061 | |
0f5a2601 PZ |
3062 | perf_pmu_enable(cpuctx->ctx.pmu); |
3063 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3064 | done: |
9e630205 SE |
3065 | |
3066 | return rotate; | |
e9d2b064 PZ |
3067 | } |
3068 | ||
026249ef FW |
3069 | #ifdef CONFIG_NO_HZ_FULL |
3070 | bool perf_event_can_stop_tick(void) | |
3071 | { | |
948b26b6 | 3072 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3073 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3074 | return false; |
d84153d6 FW |
3075 | else |
3076 | return true; | |
026249ef FW |
3077 | } |
3078 | #endif | |
3079 | ||
e9d2b064 PZ |
3080 | void perf_event_task_tick(void) |
3081 | { | |
2fde4f94 MR |
3082 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3083 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3084 | int throttled; |
b5ab4cd5 | 3085 | |
e9d2b064 PZ |
3086 | WARN_ON(!irqs_disabled()); |
3087 | ||
e050e3f0 SE |
3088 | __this_cpu_inc(perf_throttled_seq); |
3089 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3090 | ||
2fde4f94 | 3091 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3092 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3093 | } |
3094 | ||
889ff015 FW |
3095 | static int event_enable_on_exec(struct perf_event *event, |
3096 | struct perf_event_context *ctx) | |
3097 | { | |
3098 | if (!event->attr.enable_on_exec) | |
3099 | return 0; | |
3100 | ||
3101 | event->attr.enable_on_exec = 0; | |
3102 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3103 | return 0; | |
3104 | ||
1d9b482e | 3105 | __perf_event_mark_enabled(event); |
889ff015 FW |
3106 | |
3107 | return 1; | |
3108 | } | |
3109 | ||
57e7986e | 3110 | /* |
cdd6c482 | 3111 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3112 | * This expects task == current. |
3113 | */ | |
c1274499 | 3114 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3115 | { |
c1274499 | 3116 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3117 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3118 | struct perf_event *event; |
57e7986e PM |
3119 | unsigned long flags; |
3120 | int enabled = 0; | |
3121 | ||
3122 | local_irq_save(flags); | |
c1274499 | 3123 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3124 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3125 | goto out; |
3126 | ||
3e349507 PZ |
3127 | cpuctx = __get_cpu_context(ctx); |
3128 | perf_ctx_lock(cpuctx, ctx); | |
3129 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3130 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3131 | |
3132 | /* | |
3e349507 | 3133 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3134 | */ |
3e349507 | 3135 | if (enabled) { |
211de6eb | 3136 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3137 | ctx_resched(cpuctx, ctx); |
3138 | } | |
3139 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3140 | |
9ed6060d | 3141 | out: |
57e7986e | 3142 | local_irq_restore(flags); |
211de6eb PZ |
3143 | |
3144 | if (clone_ctx) | |
3145 | put_ctx(clone_ctx); | |
57e7986e PM |
3146 | } |
3147 | ||
e041e328 PZ |
3148 | void perf_event_exec(void) |
3149 | { | |
e041e328 PZ |
3150 | int ctxn; |
3151 | ||
3152 | rcu_read_lock(); | |
c1274499 PZ |
3153 | for_each_task_context_nr(ctxn) |
3154 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3155 | rcu_read_unlock(); |
3156 | } | |
3157 | ||
0492d4c5 PZ |
3158 | struct perf_read_data { |
3159 | struct perf_event *event; | |
3160 | bool group; | |
7d88962e | 3161 | int ret; |
0492d4c5 PZ |
3162 | }; |
3163 | ||
0793a61d | 3164 | /* |
cdd6c482 | 3165 | * Cross CPU call to read the hardware event |
0793a61d | 3166 | */ |
cdd6c482 | 3167 | static void __perf_event_read(void *info) |
0793a61d | 3168 | { |
0492d4c5 PZ |
3169 | struct perf_read_data *data = info; |
3170 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3171 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3172 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3173 | struct pmu *pmu = event->pmu; |
621a01ea | 3174 | |
e1ac3614 PM |
3175 | /* |
3176 | * If this is a task context, we need to check whether it is | |
3177 | * the current task context of this cpu. If not it has been | |
3178 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3179 | * event->count would have been updated to a recent sample |
3180 | * when the event was scheduled out. | |
e1ac3614 PM |
3181 | */ |
3182 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3183 | return; | |
3184 | ||
e625cce1 | 3185 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3186 | if (ctx->is_active) { |
542e72fc | 3187 | update_context_time(ctx); |
e5d1367f SE |
3188 | update_cgrp_time_from_event(event); |
3189 | } | |
0492d4c5 | 3190 | |
cdd6c482 | 3191 | update_event_times(event); |
4a00c16e SB |
3192 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3193 | goto unlock; | |
0492d4c5 | 3194 | |
4a00c16e SB |
3195 | if (!data->group) { |
3196 | pmu->read(event); | |
3197 | data->ret = 0; | |
0492d4c5 | 3198 | goto unlock; |
4a00c16e SB |
3199 | } |
3200 | ||
3201 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3202 | ||
3203 | pmu->read(event); | |
0492d4c5 PZ |
3204 | |
3205 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3206 | update_event_times(sub); | |
4a00c16e SB |
3207 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3208 | /* | |
3209 | * Use sibling's PMU rather than @event's since | |
3210 | * sibling could be on different (eg: software) PMU. | |
3211 | */ | |
0492d4c5 | 3212 | sub->pmu->read(sub); |
4a00c16e | 3213 | } |
0492d4c5 | 3214 | } |
4a00c16e SB |
3215 | |
3216 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3217 | |
3218 | unlock: | |
e625cce1 | 3219 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3220 | } |
3221 | ||
b5e58793 PZ |
3222 | static inline u64 perf_event_count(struct perf_event *event) |
3223 | { | |
eacd3ecc MF |
3224 | if (event->pmu->count) |
3225 | return event->pmu->count(event); | |
3226 | ||
3227 | return __perf_event_count(event); | |
b5e58793 PZ |
3228 | } |
3229 | ||
ffe8690c KX |
3230 | /* |
3231 | * NMI-safe method to read a local event, that is an event that | |
3232 | * is: | |
3233 | * - either for the current task, or for this CPU | |
3234 | * - does not have inherit set, for inherited task events | |
3235 | * will not be local and we cannot read them atomically | |
3236 | * - must not have a pmu::count method | |
3237 | */ | |
3238 | u64 perf_event_read_local(struct perf_event *event) | |
3239 | { | |
3240 | unsigned long flags; | |
3241 | u64 val; | |
3242 | ||
3243 | /* | |
3244 | * Disabling interrupts avoids all counter scheduling (context | |
3245 | * switches, timer based rotation and IPIs). | |
3246 | */ | |
3247 | local_irq_save(flags); | |
3248 | ||
3249 | /* If this is a per-task event, it must be for current */ | |
3250 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3251 | event->hw.target != current); | |
3252 | ||
3253 | /* If this is a per-CPU event, it must be for this CPU */ | |
3254 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3255 | event->cpu != smp_processor_id()); | |
3256 | ||
3257 | /* | |
3258 | * It must not be an event with inherit set, we cannot read | |
3259 | * all child counters from atomic context. | |
3260 | */ | |
3261 | WARN_ON_ONCE(event->attr.inherit); | |
3262 | ||
3263 | /* | |
3264 | * It must not have a pmu::count method, those are not | |
3265 | * NMI safe. | |
3266 | */ | |
3267 | WARN_ON_ONCE(event->pmu->count); | |
3268 | ||
3269 | /* | |
3270 | * If the event is currently on this CPU, its either a per-task event, | |
3271 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3272 | * oncpu == -1). | |
3273 | */ | |
3274 | if (event->oncpu == smp_processor_id()) | |
3275 | event->pmu->read(event); | |
3276 | ||
3277 | val = local64_read(&event->count); | |
3278 | local_irq_restore(flags); | |
3279 | ||
3280 | return val; | |
3281 | } | |
3282 | ||
7d88962e | 3283 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3284 | { |
7d88962e SB |
3285 | int ret = 0; |
3286 | ||
0793a61d | 3287 | /* |
cdd6c482 IM |
3288 | * If event is enabled and currently active on a CPU, update the |
3289 | * value in the event structure: | |
0793a61d | 3290 | */ |
cdd6c482 | 3291 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3292 | struct perf_read_data data = { |
3293 | .event = event, | |
3294 | .group = group, | |
7d88962e | 3295 | .ret = 0, |
0492d4c5 | 3296 | }; |
cdd6c482 | 3297 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3298 | __perf_event_read, &data, 1); |
7d88962e | 3299 | ret = data.ret; |
cdd6c482 | 3300 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3301 | struct perf_event_context *ctx = event->ctx; |
3302 | unsigned long flags; | |
3303 | ||
e625cce1 | 3304 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3305 | /* |
3306 | * may read while context is not active | |
3307 | * (e.g., thread is blocked), in that case | |
3308 | * we cannot update context time | |
3309 | */ | |
e5d1367f | 3310 | if (ctx->is_active) { |
c530ccd9 | 3311 | update_context_time(ctx); |
e5d1367f SE |
3312 | update_cgrp_time_from_event(event); |
3313 | } | |
0492d4c5 PZ |
3314 | if (group) |
3315 | update_group_times(event); | |
3316 | else | |
3317 | update_event_times(event); | |
e625cce1 | 3318 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3319 | } |
7d88962e SB |
3320 | |
3321 | return ret; | |
0793a61d TG |
3322 | } |
3323 | ||
a63eaf34 | 3324 | /* |
cdd6c482 | 3325 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3326 | */ |
eb184479 | 3327 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3328 | { |
e625cce1 | 3329 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3330 | mutex_init(&ctx->mutex); |
2fde4f94 | 3331 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3332 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3333 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3334 | INIT_LIST_HEAD(&ctx->event_list); |
3335 | atomic_set(&ctx->refcount, 1); | |
fadfe7be | 3336 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); |
eb184479 PZ |
3337 | } |
3338 | ||
3339 | static struct perf_event_context * | |
3340 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3341 | { | |
3342 | struct perf_event_context *ctx; | |
3343 | ||
3344 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3345 | if (!ctx) | |
3346 | return NULL; | |
3347 | ||
3348 | __perf_event_init_context(ctx); | |
3349 | if (task) { | |
3350 | ctx->task = task; | |
3351 | get_task_struct(task); | |
0793a61d | 3352 | } |
eb184479 PZ |
3353 | ctx->pmu = pmu; |
3354 | ||
3355 | return ctx; | |
a63eaf34 PM |
3356 | } |
3357 | ||
2ebd4ffb MH |
3358 | static struct task_struct * |
3359 | find_lively_task_by_vpid(pid_t vpid) | |
3360 | { | |
3361 | struct task_struct *task; | |
3362 | int err; | |
0793a61d TG |
3363 | |
3364 | rcu_read_lock(); | |
2ebd4ffb | 3365 | if (!vpid) |
0793a61d TG |
3366 | task = current; |
3367 | else | |
2ebd4ffb | 3368 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3369 | if (task) |
3370 | get_task_struct(task); | |
3371 | rcu_read_unlock(); | |
3372 | ||
3373 | if (!task) | |
3374 | return ERR_PTR(-ESRCH); | |
3375 | ||
0793a61d | 3376 | /* Reuse ptrace permission checks for now. */ |
c93f7669 PM |
3377 | err = -EACCES; |
3378 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3379 | goto errout; | |
3380 | ||
2ebd4ffb MH |
3381 | return task; |
3382 | errout: | |
3383 | put_task_struct(task); | |
3384 | return ERR_PTR(err); | |
3385 | ||
3386 | } | |
3387 | ||
fe4b04fa PZ |
3388 | /* |
3389 | * Returns a matching context with refcount and pincount. | |
3390 | */ | |
108b02cf | 3391 | static struct perf_event_context * |
4af57ef2 YZ |
3392 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3393 | struct perf_event *event) | |
0793a61d | 3394 | { |
211de6eb | 3395 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3396 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3397 | void *task_ctx_data = NULL; |
25346b93 | 3398 | unsigned long flags; |
8dc85d54 | 3399 | int ctxn, err; |
4af57ef2 | 3400 | int cpu = event->cpu; |
0793a61d | 3401 | |
22a4ec72 | 3402 | if (!task) { |
cdd6c482 | 3403 | /* Must be root to operate on a CPU event: */ |
0764771d | 3404 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3405 | return ERR_PTR(-EACCES); |
3406 | ||
0793a61d | 3407 | /* |
cdd6c482 | 3408 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3409 | * offline CPU and activate it when the CPU comes up, but |
3410 | * that's for later. | |
3411 | */ | |
f6325e30 | 3412 | if (!cpu_online(cpu)) |
0793a61d TG |
3413 | return ERR_PTR(-ENODEV); |
3414 | ||
108b02cf | 3415 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3416 | ctx = &cpuctx->ctx; |
c93f7669 | 3417 | get_ctx(ctx); |
fe4b04fa | 3418 | ++ctx->pin_count; |
0793a61d | 3419 | |
0793a61d TG |
3420 | return ctx; |
3421 | } | |
3422 | ||
8dc85d54 PZ |
3423 | err = -EINVAL; |
3424 | ctxn = pmu->task_ctx_nr; | |
3425 | if (ctxn < 0) | |
3426 | goto errout; | |
3427 | ||
4af57ef2 YZ |
3428 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3429 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3430 | if (!task_ctx_data) { | |
3431 | err = -ENOMEM; | |
3432 | goto errout; | |
3433 | } | |
3434 | } | |
3435 | ||
9ed6060d | 3436 | retry: |
8dc85d54 | 3437 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3438 | if (ctx) { |
211de6eb | 3439 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3440 | ++ctx->pin_count; |
4af57ef2 YZ |
3441 | |
3442 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3443 | ctx->task_ctx_data = task_ctx_data; | |
3444 | task_ctx_data = NULL; | |
3445 | } | |
e625cce1 | 3446 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3447 | |
3448 | if (clone_ctx) | |
3449 | put_ctx(clone_ctx); | |
9137fb28 | 3450 | } else { |
eb184479 | 3451 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3452 | err = -ENOMEM; |
3453 | if (!ctx) | |
3454 | goto errout; | |
eb184479 | 3455 | |
4af57ef2 YZ |
3456 | if (task_ctx_data) { |
3457 | ctx->task_ctx_data = task_ctx_data; | |
3458 | task_ctx_data = NULL; | |
3459 | } | |
3460 | ||
dbe08d82 ON |
3461 | err = 0; |
3462 | mutex_lock(&task->perf_event_mutex); | |
3463 | /* | |
3464 | * If it has already passed perf_event_exit_task(). | |
3465 | * we must see PF_EXITING, it takes this mutex too. | |
3466 | */ | |
3467 | if (task->flags & PF_EXITING) | |
3468 | err = -ESRCH; | |
3469 | else if (task->perf_event_ctxp[ctxn]) | |
3470 | err = -EAGAIN; | |
fe4b04fa | 3471 | else { |
9137fb28 | 3472 | get_ctx(ctx); |
fe4b04fa | 3473 | ++ctx->pin_count; |
dbe08d82 | 3474 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3475 | } |
dbe08d82 ON |
3476 | mutex_unlock(&task->perf_event_mutex); |
3477 | ||
3478 | if (unlikely(err)) { | |
9137fb28 | 3479 | put_ctx(ctx); |
dbe08d82 ON |
3480 | |
3481 | if (err == -EAGAIN) | |
3482 | goto retry; | |
3483 | goto errout; | |
a63eaf34 PM |
3484 | } |
3485 | } | |
3486 | ||
4af57ef2 | 3487 | kfree(task_ctx_data); |
0793a61d | 3488 | return ctx; |
c93f7669 | 3489 | |
9ed6060d | 3490 | errout: |
4af57ef2 | 3491 | kfree(task_ctx_data); |
c93f7669 | 3492 | return ERR_PTR(err); |
0793a61d TG |
3493 | } |
3494 | ||
6fb2915d | 3495 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3496 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3497 | |
cdd6c482 | 3498 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3499 | { |
cdd6c482 | 3500 | struct perf_event *event; |
592903cd | 3501 | |
cdd6c482 IM |
3502 | event = container_of(head, struct perf_event, rcu_head); |
3503 | if (event->ns) | |
3504 | put_pid_ns(event->ns); | |
6fb2915d | 3505 | perf_event_free_filter(event); |
cdd6c482 | 3506 | kfree(event); |
592903cd PZ |
3507 | } |
3508 | ||
b69cf536 PZ |
3509 | static void ring_buffer_attach(struct perf_event *event, |
3510 | struct ring_buffer *rb); | |
925d519a | 3511 | |
4beb31f3 | 3512 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3513 | { |
4beb31f3 FW |
3514 | if (event->parent) |
3515 | return; | |
3516 | ||
4beb31f3 FW |
3517 | if (is_cgroup_event(event)) |
3518 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3519 | } | |
925d519a | 3520 | |
4beb31f3 FW |
3521 | static void unaccount_event(struct perf_event *event) |
3522 | { | |
25432ae9 PZ |
3523 | bool dec = false; |
3524 | ||
4beb31f3 FW |
3525 | if (event->parent) |
3526 | return; | |
3527 | ||
3528 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3529 | dec = true; |
4beb31f3 FW |
3530 | if (event->attr.mmap || event->attr.mmap_data) |
3531 | atomic_dec(&nr_mmap_events); | |
3532 | if (event->attr.comm) | |
3533 | atomic_dec(&nr_comm_events); | |
3534 | if (event->attr.task) | |
3535 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3536 | if (event->attr.freq) |
3537 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3538 | if (event->attr.context_switch) { |
25432ae9 | 3539 | dec = true; |
45ac1403 AH |
3540 | atomic_dec(&nr_switch_events); |
3541 | } | |
4beb31f3 | 3542 | if (is_cgroup_event(event)) |
25432ae9 | 3543 | dec = true; |
4beb31f3 | 3544 | if (has_branch_stack(event)) |
25432ae9 PZ |
3545 | dec = true; |
3546 | ||
3547 | if (dec) | |
4beb31f3 FW |
3548 | static_key_slow_dec_deferred(&perf_sched_events); |
3549 | ||
3550 | unaccount_event_cpu(event, event->cpu); | |
3551 | } | |
925d519a | 3552 | |
bed5b25a AS |
3553 | /* |
3554 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3555 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3556 | * at a time, so we disallow creating events that might conflict, namely: | |
3557 | * | |
3558 | * 1) cpu-wide events in the presence of per-task events, | |
3559 | * 2) per-task events in the presence of cpu-wide events, | |
3560 | * 3) two matching events on the same context. | |
3561 | * | |
3562 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
3563 | * __free_event()), the latter -- before the first perf_install_in_context(). | |
3564 | */ | |
3565 | static int exclusive_event_init(struct perf_event *event) | |
3566 | { | |
3567 | struct pmu *pmu = event->pmu; | |
3568 | ||
3569 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3570 | return 0; | |
3571 | ||
3572 | /* | |
3573 | * Prevent co-existence of per-task and cpu-wide events on the | |
3574 | * same exclusive pmu. | |
3575 | * | |
3576 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3577 | * events on this "exclusive" pmu, positive means there are | |
3578 | * per-task events. | |
3579 | * | |
3580 | * Since this is called in perf_event_alloc() path, event::ctx | |
3581 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3582 | * to mean "per-task event", because unlike other attach states it | |
3583 | * never gets cleared. | |
3584 | */ | |
3585 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3586 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3587 | return -EBUSY; | |
3588 | } else { | |
3589 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3590 | return -EBUSY; | |
3591 | } | |
3592 | ||
3593 | return 0; | |
3594 | } | |
3595 | ||
3596 | static void exclusive_event_destroy(struct perf_event *event) | |
3597 | { | |
3598 | struct pmu *pmu = event->pmu; | |
3599 | ||
3600 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3601 | return; | |
3602 | ||
3603 | /* see comment in exclusive_event_init() */ | |
3604 | if (event->attach_state & PERF_ATTACH_TASK) | |
3605 | atomic_dec(&pmu->exclusive_cnt); | |
3606 | else | |
3607 | atomic_inc(&pmu->exclusive_cnt); | |
3608 | } | |
3609 | ||
3610 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3611 | { | |
3612 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3613 | (e1->cpu == e2->cpu || | |
3614 | e1->cpu == -1 || | |
3615 | e2->cpu == -1)) | |
3616 | return true; | |
3617 | return false; | |
3618 | } | |
3619 | ||
3620 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3621 | static bool exclusive_event_installable(struct perf_event *event, | |
3622 | struct perf_event_context *ctx) | |
3623 | { | |
3624 | struct perf_event *iter_event; | |
3625 | struct pmu *pmu = event->pmu; | |
3626 | ||
3627 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3628 | return true; | |
3629 | ||
3630 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3631 | if (exclusive_event_match(iter_event, event)) | |
3632 | return false; | |
3633 | } | |
3634 | ||
3635 | return true; | |
3636 | } | |
3637 | ||
766d6c07 FW |
3638 | static void __free_event(struct perf_event *event) |
3639 | { | |
cdd6c482 | 3640 | if (!event->parent) { |
927c7a9e FW |
3641 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3642 | put_callchain_buffers(); | |
f344011c | 3643 | } |
9ee318a7 | 3644 | |
dead9f29 AS |
3645 | perf_event_free_bpf_prog(event); |
3646 | ||
766d6c07 FW |
3647 | if (event->destroy) |
3648 | event->destroy(event); | |
3649 | ||
3650 | if (event->ctx) | |
3651 | put_ctx(event->ctx); | |
3652 | ||
bed5b25a AS |
3653 | if (event->pmu) { |
3654 | exclusive_event_destroy(event); | |
c464c76e | 3655 | module_put(event->pmu->module); |
bed5b25a | 3656 | } |
c464c76e | 3657 | |
766d6c07 FW |
3658 | call_rcu(&event->rcu_head, free_event_rcu); |
3659 | } | |
683ede43 PZ |
3660 | |
3661 | static void _free_event(struct perf_event *event) | |
f1600952 | 3662 | { |
e360adbe | 3663 | irq_work_sync(&event->pending); |
925d519a | 3664 | |
4beb31f3 | 3665 | unaccount_event(event); |
9ee318a7 | 3666 | |
76369139 | 3667 | if (event->rb) { |
9bb5d40c PZ |
3668 | /* |
3669 | * Can happen when we close an event with re-directed output. | |
3670 | * | |
3671 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3672 | * over us; possibly making our ring_buffer_put() the last. | |
3673 | */ | |
3674 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3675 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3676 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3677 | } |
3678 | ||
e5d1367f SE |
3679 | if (is_cgroup_event(event)) |
3680 | perf_detach_cgroup(event); | |
3681 | ||
766d6c07 | 3682 | __free_event(event); |
f1600952 PZ |
3683 | } |
3684 | ||
683ede43 PZ |
3685 | /* |
3686 | * Used to free events which have a known refcount of 1, such as in error paths | |
3687 | * where the event isn't exposed yet and inherited events. | |
3688 | */ | |
3689 | static void free_event(struct perf_event *event) | |
0793a61d | 3690 | { |
683ede43 PZ |
3691 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3692 | "unexpected event refcount: %ld; ptr=%p\n", | |
3693 | atomic_long_read(&event->refcount), event)) { | |
3694 | /* leak to avoid use-after-free */ | |
3695 | return; | |
3696 | } | |
0793a61d | 3697 | |
683ede43 | 3698 | _free_event(event); |
0793a61d TG |
3699 | } |
3700 | ||
a66a3052 | 3701 | /* |
f8697762 | 3702 | * Remove user event from the owner task. |
a66a3052 | 3703 | */ |
f8697762 | 3704 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3705 | { |
8882135b | 3706 | struct task_struct *owner; |
fb0459d7 | 3707 | |
8882135b PZ |
3708 | rcu_read_lock(); |
3709 | owner = ACCESS_ONCE(event->owner); | |
3710 | /* | |
3711 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3712 | * !owner it means the list deletion is complete and we can indeed | |
3713 | * free this event, otherwise we need to serialize on | |
3714 | * owner->perf_event_mutex. | |
3715 | */ | |
3716 | smp_read_barrier_depends(); | |
3717 | if (owner) { | |
3718 | /* | |
3719 | * Since delayed_put_task_struct() also drops the last | |
3720 | * task reference we can safely take a new reference | |
3721 | * while holding the rcu_read_lock(). | |
3722 | */ | |
3723 | get_task_struct(owner); | |
3724 | } | |
3725 | rcu_read_unlock(); | |
3726 | ||
3727 | if (owner) { | |
f63a8daa PZ |
3728 | /* |
3729 | * If we're here through perf_event_exit_task() we're already | |
3730 | * holding ctx->mutex which would be an inversion wrt. the | |
3731 | * normal lock order. | |
3732 | * | |
3733 | * However we can safely take this lock because its the child | |
3734 | * ctx->mutex. | |
3735 | */ | |
3736 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3737 | ||
8882135b PZ |
3738 | /* |
3739 | * We have to re-check the event->owner field, if it is cleared | |
3740 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3741 | * ensured they're done, and we can proceed with freeing the | |
3742 | * event. | |
3743 | */ | |
3744 | if (event->owner) | |
3745 | list_del_init(&event->owner_entry); | |
3746 | mutex_unlock(&owner->perf_event_mutex); | |
3747 | put_task_struct(owner); | |
3748 | } | |
f8697762 JO |
3749 | } |
3750 | ||
f8697762 JO |
3751 | static void put_event(struct perf_event *event) |
3752 | { | |
a83fe28e | 3753 | struct perf_event_context *ctx; |
f8697762 JO |
3754 | |
3755 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3756 | return; | |
3757 | ||
3758 | if (!is_kernel_event(event)) | |
3759 | perf_remove_from_owner(event); | |
8882135b | 3760 | |
683ede43 PZ |
3761 | /* |
3762 | * There are two ways this annotation is useful: | |
3763 | * | |
3764 | * 1) there is a lock recursion from perf_event_exit_task | |
3765 | * see the comment there. | |
3766 | * | |
3767 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3768 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3769 | * holding ctx->mutex, however this is called after |
3770 | * the last filedesc died, so there is no possibility | |
3771 | * to trigger the AB-BA case. | |
3772 | */ | |
a83fe28e PZ |
3773 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3774 | WARN_ON_ONCE(ctx->parent_ctx); | |
683ede43 | 3775 | perf_remove_from_context(event, true); |
d415a7f1 | 3776 | perf_event_ctx_unlock(event, ctx); |
683ede43 PZ |
3777 | |
3778 | _free_event(event); | |
a6fa941d AV |
3779 | } |
3780 | ||
683ede43 PZ |
3781 | int perf_event_release_kernel(struct perf_event *event) |
3782 | { | |
3783 | put_event(event); | |
3784 | return 0; | |
3785 | } | |
3786 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3787 | ||
8b10c5e2 PZ |
3788 | /* |
3789 | * Called when the last reference to the file is gone. | |
3790 | */ | |
a6fa941d AV |
3791 | static int perf_release(struct inode *inode, struct file *file) |
3792 | { | |
3793 | put_event(file->private_data); | |
3794 | return 0; | |
fb0459d7 | 3795 | } |
fb0459d7 | 3796 | |
fadfe7be JO |
3797 | /* |
3798 | * Remove all orphanes events from the context. | |
3799 | */ | |
3800 | static void orphans_remove_work(struct work_struct *work) | |
3801 | { | |
3802 | struct perf_event_context *ctx; | |
3803 | struct perf_event *event, *tmp; | |
3804 | ||
3805 | ctx = container_of(work, struct perf_event_context, | |
3806 | orphans_remove.work); | |
3807 | ||
3808 | mutex_lock(&ctx->mutex); | |
3809 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3810 | struct perf_event *parent_event = event->parent; | |
3811 | ||
3812 | if (!is_orphaned_child(event)) | |
3813 | continue; | |
3814 | ||
3815 | perf_remove_from_context(event, true); | |
3816 | ||
3817 | mutex_lock(&parent_event->child_mutex); | |
3818 | list_del_init(&event->child_list); | |
3819 | mutex_unlock(&parent_event->child_mutex); | |
3820 | ||
3821 | free_event(event); | |
3822 | put_event(parent_event); | |
3823 | } | |
3824 | ||
3825 | raw_spin_lock_irq(&ctx->lock); | |
3826 | ctx->orphans_remove_sched = false; | |
3827 | raw_spin_unlock_irq(&ctx->lock); | |
3828 | mutex_unlock(&ctx->mutex); | |
3829 | ||
3830 | put_ctx(ctx); | |
3831 | } | |
3832 | ||
59ed446f | 3833 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3834 | { |
cdd6c482 | 3835 | struct perf_event *child; |
e53c0994 PZ |
3836 | u64 total = 0; |
3837 | ||
59ed446f PZ |
3838 | *enabled = 0; |
3839 | *running = 0; | |
3840 | ||
6f10581a | 3841 | mutex_lock(&event->child_mutex); |
01add3ea | 3842 | |
7d88962e | 3843 | (void)perf_event_read(event, false); |
01add3ea SB |
3844 | total += perf_event_count(event); |
3845 | ||
59ed446f PZ |
3846 | *enabled += event->total_time_enabled + |
3847 | atomic64_read(&event->child_total_time_enabled); | |
3848 | *running += event->total_time_running + | |
3849 | atomic64_read(&event->child_total_time_running); | |
3850 | ||
3851 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3852 | (void)perf_event_read(child, false); |
01add3ea | 3853 | total += perf_event_count(child); |
59ed446f PZ |
3854 | *enabled += child->total_time_enabled; |
3855 | *running += child->total_time_running; | |
3856 | } | |
6f10581a | 3857 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3858 | |
3859 | return total; | |
3860 | } | |
fb0459d7 | 3861 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3862 | |
7d88962e | 3863 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3864 | u64 read_format, u64 *values) |
3dab77fb | 3865 | { |
fa8c2693 PZ |
3866 | struct perf_event *sub; |
3867 | int n = 1; /* skip @nr */ | |
7d88962e | 3868 | int ret; |
f63a8daa | 3869 | |
7d88962e SB |
3870 | ret = perf_event_read(leader, true); |
3871 | if (ret) | |
3872 | return ret; | |
abf4868b | 3873 | |
fa8c2693 PZ |
3874 | /* |
3875 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3876 | * will be identical to those of the leader, so we only publish one | |
3877 | * set. | |
3878 | */ | |
3879 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3880 | values[n++] += leader->total_time_enabled + | |
3881 | atomic64_read(&leader->child_total_time_enabled); | |
3882 | } | |
3dab77fb | 3883 | |
fa8c2693 PZ |
3884 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3885 | values[n++] += leader->total_time_running + | |
3886 | atomic64_read(&leader->child_total_time_running); | |
3887 | } | |
3888 | ||
3889 | /* | |
3890 | * Write {count,id} tuples for every sibling. | |
3891 | */ | |
3892 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3893 | if (read_format & PERF_FORMAT_ID) |
3894 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3895 | |
fa8c2693 PZ |
3896 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3897 | values[n++] += perf_event_count(sub); | |
3898 | if (read_format & PERF_FORMAT_ID) | |
3899 | values[n++] = primary_event_id(sub); | |
3900 | } | |
7d88962e SB |
3901 | |
3902 | return 0; | |
fa8c2693 | 3903 | } |
3dab77fb | 3904 | |
fa8c2693 PZ |
3905 | static int perf_read_group(struct perf_event *event, |
3906 | u64 read_format, char __user *buf) | |
3907 | { | |
3908 | struct perf_event *leader = event->group_leader, *child; | |
3909 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3910 | int ret; |
fa8c2693 | 3911 | u64 *values; |
3dab77fb | 3912 | |
fa8c2693 | 3913 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3914 | |
fa8c2693 PZ |
3915 | values = kzalloc(event->read_size, GFP_KERNEL); |
3916 | if (!values) | |
3917 | return -ENOMEM; | |
3dab77fb | 3918 | |
fa8c2693 PZ |
3919 | values[0] = 1 + leader->nr_siblings; |
3920 | ||
3921 | /* | |
3922 | * By locking the child_mutex of the leader we effectively | |
3923 | * lock the child list of all siblings.. XXX explain how. | |
3924 | */ | |
3925 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3926 | |
7d88962e SB |
3927 | ret = __perf_read_group_add(leader, read_format, values); |
3928 | if (ret) | |
3929 | goto unlock; | |
3930 | ||
3931 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3932 | ret = __perf_read_group_add(child, read_format, values); | |
3933 | if (ret) | |
3934 | goto unlock; | |
3935 | } | |
abf4868b | 3936 | |
fa8c2693 | 3937 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3938 | |
7d88962e | 3939 | ret = event->read_size; |
fa8c2693 PZ |
3940 | if (copy_to_user(buf, values, event->read_size)) |
3941 | ret = -EFAULT; | |
7d88962e | 3942 | goto out; |
fa8c2693 | 3943 | |
7d88962e SB |
3944 | unlock: |
3945 | mutex_unlock(&leader->child_mutex); | |
3946 | out: | |
fa8c2693 | 3947 | kfree(values); |
abf4868b | 3948 | return ret; |
3dab77fb PZ |
3949 | } |
3950 | ||
b15f495b | 3951 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3952 | u64 read_format, char __user *buf) |
3953 | { | |
59ed446f | 3954 | u64 enabled, running; |
3dab77fb PZ |
3955 | u64 values[4]; |
3956 | int n = 0; | |
3957 | ||
59ed446f PZ |
3958 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3959 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3960 | values[n++] = enabled; | |
3961 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3962 | values[n++] = running; | |
3dab77fb | 3963 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3964 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3965 | |
3966 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3967 | return -EFAULT; | |
3968 | ||
3969 | return n * sizeof(u64); | |
3970 | } | |
3971 | ||
dc633982 JO |
3972 | static bool is_event_hup(struct perf_event *event) |
3973 | { | |
3974 | bool no_children; | |
3975 | ||
3976 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3977 | return false; | |
3978 | ||
3979 | mutex_lock(&event->child_mutex); | |
3980 | no_children = list_empty(&event->child_list); | |
3981 | mutex_unlock(&event->child_mutex); | |
3982 | return no_children; | |
3983 | } | |
3984 | ||
0793a61d | 3985 | /* |
cdd6c482 | 3986 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3987 | */ |
3988 | static ssize_t | |
b15f495b | 3989 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3990 | { |
cdd6c482 | 3991 | u64 read_format = event->attr.read_format; |
3dab77fb | 3992 | int ret; |
0793a61d | 3993 | |
3b6f9e5c | 3994 | /* |
cdd6c482 | 3995 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
3996 | * error state (i.e. because it was pinned but it couldn't be |
3997 | * scheduled on to the CPU at some point). | |
3998 | */ | |
cdd6c482 | 3999 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4000 | return 0; |
4001 | ||
c320c7b7 | 4002 | if (count < event->read_size) |
3dab77fb PZ |
4003 | return -ENOSPC; |
4004 | ||
cdd6c482 | 4005 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4006 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4007 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4008 | else |
b15f495b | 4009 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4010 | |
3dab77fb | 4011 | return ret; |
0793a61d TG |
4012 | } |
4013 | ||
0793a61d TG |
4014 | static ssize_t |
4015 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4016 | { | |
cdd6c482 | 4017 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4018 | struct perf_event_context *ctx; |
4019 | int ret; | |
0793a61d | 4020 | |
f63a8daa | 4021 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4022 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4023 | perf_event_ctx_unlock(event, ctx); |
4024 | ||
4025 | return ret; | |
0793a61d TG |
4026 | } |
4027 | ||
4028 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4029 | { | |
cdd6c482 | 4030 | struct perf_event *event = file->private_data; |
76369139 | 4031 | struct ring_buffer *rb; |
61b67684 | 4032 | unsigned int events = POLLHUP; |
c7138f37 | 4033 | |
e708d7ad | 4034 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4035 | |
dc633982 | 4036 | if (is_event_hup(event)) |
179033b3 | 4037 | return events; |
c7138f37 | 4038 | |
10c6db11 | 4039 | /* |
9bb5d40c PZ |
4040 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4041 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4042 | */ |
4043 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4044 | rb = event->rb; |
4045 | if (rb) | |
76369139 | 4046 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4047 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4048 | return events; |
4049 | } | |
4050 | ||
f63a8daa | 4051 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4052 | { |
7d88962e | 4053 | (void)perf_event_read(event, false); |
e7850595 | 4054 | local64_set(&event->count, 0); |
cdd6c482 | 4055 | perf_event_update_userpage(event); |
3df5edad PZ |
4056 | } |
4057 | ||
c93f7669 | 4058 | /* |
cdd6c482 IM |
4059 | * Holding the top-level event's child_mutex means that any |
4060 | * descendant process that has inherited this event will block | |
4061 | * in sync_child_event if it goes to exit, thus satisfying the | |
4062 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 4063 | */ |
cdd6c482 IM |
4064 | static void perf_event_for_each_child(struct perf_event *event, |
4065 | void (*func)(struct perf_event *)) | |
3df5edad | 4066 | { |
cdd6c482 | 4067 | struct perf_event *child; |
3df5edad | 4068 | |
cdd6c482 | 4069 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4070 | |
cdd6c482 IM |
4071 | mutex_lock(&event->child_mutex); |
4072 | func(event); | |
4073 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4074 | func(child); |
cdd6c482 | 4075 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4076 | } |
4077 | ||
cdd6c482 IM |
4078 | static void perf_event_for_each(struct perf_event *event, |
4079 | void (*func)(struct perf_event *)) | |
3df5edad | 4080 | { |
cdd6c482 IM |
4081 | struct perf_event_context *ctx = event->ctx; |
4082 | struct perf_event *sibling; | |
3df5edad | 4083 | |
f63a8daa PZ |
4084 | lockdep_assert_held(&ctx->mutex); |
4085 | ||
cdd6c482 | 4086 | event = event->group_leader; |
75f937f2 | 4087 | |
cdd6c482 | 4088 | perf_event_for_each_child(event, func); |
cdd6c482 | 4089 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4090 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4091 | } |
4092 | ||
fae3fde6 PZ |
4093 | static void __perf_event_period(struct perf_event *event, |
4094 | struct perf_cpu_context *cpuctx, | |
4095 | struct perf_event_context *ctx, | |
4096 | void *info) | |
c7999c6f | 4097 | { |
fae3fde6 | 4098 | u64 value = *((u64 *)info); |
c7999c6f | 4099 | bool active; |
08247e31 | 4100 | |
cdd6c482 | 4101 | if (event->attr.freq) { |
cdd6c482 | 4102 | event->attr.sample_freq = value; |
08247e31 | 4103 | } else { |
cdd6c482 IM |
4104 | event->attr.sample_period = value; |
4105 | event->hw.sample_period = value; | |
08247e31 | 4106 | } |
bad7192b PZ |
4107 | |
4108 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4109 | if (active) { | |
4110 | perf_pmu_disable(ctx->pmu); | |
4111 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4112 | } | |
4113 | ||
4114 | local64_set(&event->hw.period_left, 0); | |
4115 | ||
4116 | if (active) { | |
4117 | event->pmu->start(event, PERF_EF_RELOAD); | |
4118 | perf_pmu_enable(ctx->pmu); | |
4119 | } | |
c7999c6f PZ |
4120 | } |
4121 | ||
4122 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4123 | { | |
c7999c6f PZ |
4124 | u64 value; |
4125 | ||
4126 | if (!is_sampling_event(event)) | |
4127 | return -EINVAL; | |
4128 | ||
4129 | if (copy_from_user(&value, arg, sizeof(value))) | |
4130 | return -EFAULT; | |
4131 | ||
4132 | if (!value) | |
4133 | return -EINVAL; | |
4134 | ||
4135 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4136 | return -EINVAL; | |
4137 | ||
fae3fde6 | 4138 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4139 | |
c7999c6f | 4140 | return 0; |
08247e31 PZ |
4141 | } |
4142 | ||
ac9721f3 PZ |
4143 | static const struct file_operations perf_fops; |
4144 | ||
2903ff01 | 4145 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4146 | { |
2903ff01 AV |
4147 | struct fd f = fdget(fd); |
4148 | if (!f.file) | |
4149 | return -EBADF; | |
ac9721f3 | 4150 | |
2903ff01 AV |
4151 | if (f.file->f_op != &perf_fops) { |
4152 | fdput(f); | |
4153 | return -EBADF; | |
ac9721f3 | 4154 | } |
2903ff01 AV |
4155 | *p = f; |
4156 | return 0; | |
ac9721f3 PZ |
4157 | } |
4158 | ||
4159 | static int perf_event_set_output(struct perf_event *event, | |
4160 | struct perf_event *output_event); | |
6fb2915d | 4161 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4162 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4163 | |
f63a8daa | 4164 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4165 | { |
cdd6c482 | 4166 | void (*func)(struct perf_event *); |
3df5edad | 4167 | u32 flags = arg; |
d859e29f PM |
4168 | |
4169 | switch (cmd) { | |
cdd6c482 | 4170 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4171 | func = _perf_event_enable; |
d859e29f | 4172 | break; |
cdd6c482 | 4173 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4174 | func = _perf_event_disable; |
79f14641 | 4175 | break; |
cdd6c482 | 4176 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4177 | func = _perf_event_reset; |
6de6a7b9 | 4178 | break; |
3df5edad | 4179 | |
cdd6c482 | 4180 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4181 | return _perf_event_refresh(event, arg); |
08247e31 | 4182 | |
cdd6c482 IM |
4183 | case PERF_EVENT_IOC_PERIOD: |
4184 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4185 | |
cf4957f1 JO |
4186 | case PERF_EVENT_IOC_ID: |
4187 | { | |
4188 | u64 id = primary_event_id(event); | |
4189 | ||
4190 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4191 | return -EFAULT; | |
4192 | return 0; | |
4193 | } | |
4194 | ||
cdd6c482 | 4195 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4196 | { |
ac9721f3 | 4197 | int ret; |
ac9721f3 | 4198 | if (arg != -1) { |
2903ff01 AV |
4199 | struct perf_event *output_event; |
4200 | struct fd output; | |
4201 | ret = perf_fget_light(arg, &output); | |
4202 | if (ret) | |
4203 | return ret; | |
4204 | output_event = output.file->private_data; | |
4205 | ret = perf_event_set_output(event, output_event); | |
4206 | fdput(output); | |
4207 | } else { | |
4208 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4209 | } |
ac9721f3 PZ |
4210 | return ret; |
4211 | } | |
a4be7c27 | 4212 | |
6fb2915d LZ |
4213 | case PERF_EVENT_IOC_SET_FILTER: |
4214 | return perf_event_set_filter(event, (void __user *)arg); | |
4215 | ||
2541517c AS |
4216 | case PERF_EVENT_IOC_SET_BPF: |
4217 | return perf_event_set_bpf_prog(event, arg); | |
4218 | ||
d859e29f | 4219 | default: |
3df5edad | 4220 | return -ENOTTY; |
d859e29f | 4221 | } |
3df5edad PZ |
4222 | |
4223 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4224 | perf_event_for_each(event, func); |
3df5edad | 4225 | else |
cdd6c482 | 4226 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4227 | |
4228 | return 0; | |
d859e29f PM |
4229 | } |
4230 | ||
f63a8daa PZ |
4231 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4232 | { | |
4233 | struct perf_event *event = file->private_data; | |
4234 | struct perf_event_context *ctx; | |
4235 | long ret; | |
4236 | ||
4237 | ctx = perf_event_ctx_lock(event); | |
4238 | ret = _perf_ioctl(event, cmd, arg); | |
4239 | perf_event_ctx_unlock(event, ctx); | |
4240 | ||
4241 | return ret; | |
4242 | } | |
4243 | ||
b3f20785 PM |
4244 | #ifdef CONFIG_COMPAT |
4245 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4246 | unsigned long arg) | |
4247 | { | |
4248 | switch (_IOC_NR(cmd)) { | |
4249 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4250 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4251 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4252 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4253 | cmd &= ~IOCSIZE_MASK; | |
4254 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4255 | } | |
4256 | break; | |
4257 | } | |
4258 | return perf_ioctl(file, cmd, arg); | |
4259 | } | |
4260 | #else | |
4261 | # define perf_compat_ioctl NULL | |
4262 | #endif | |
4263 | ||
cdd6c482 | 4264 | int perf_event_task_enable(void) |
771d7cde | 4265 | { |
f63a8daa | 4266 | struct perf_event_context *ctx; |
cdd6c482 | 4267 | struct perf_event *event; |
771d7cde | 4268 | |
cdd6c482 | 4269 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4270 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4271 | ctx = perf_event_ctx_lock(event); | |
4272 | perf_event_for_each_child(event, _perf_event_enable); | |
4273 | perf_event_ctx_unlock(event, ctx); | |
4274 | } | |
cdd6c482 | 4275 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4276 | |
4277 | return 0; | |
4278 | } | |
4279 | ||
cdd6c482 | 4280 | int perf_event_task_disable(void) |
771d7cde | 4281 | { |
f63a8daa | 4282 | struct perf_event_context *ctx; |
cdd6c482 | 4283 | struct perf_event *event; |
771d7cde | 4284 | |
cdd6c482 | 4285 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4286 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4287 | ctx = perf_event_ctx_lock(event); | |
4288 | perf_event_for_each_child(event, _perf_event_disable); | |
4289 | perf_event_ctx_unlock(event, ctx); | |
4290 | } | |
cdd6c482 | 4291 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4292 | |
4293 | return 0; | |
4294 | } | |
4295 | ||
cdd6c482 | 4296 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4297 | { |
a4eaf7f1 PZ |
4298 | if (event->hw.state & PERF_HES_STOPPED) |
4299 | return 0; | |
4300 | ||
cdd6c482 | 4301 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4302 | return 0; |
4303 | ||
35edc2a5 | 4304 | return event->pmu->event_idx(event); |
194002b2 PZ |
4305 | } |
4306 | ||
c4794295 | 4307 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4308 | u64 *now, |
7f310a5d EM |
4309 | u64 *enabled, |
4310 | u64 *running) | |
c4794295 | 4311 | { |
e3f3541c | 4312 | u64 ctx_time; |
c4794295 | 4313 | |
e3f3541c PZ |
4314 | *now = perf_clock(); |
4315 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4316 | *enabled = ctx_time - event->tstamp_enabled; |
4317 | *running = ctx_time - event->tstamp_running; | |
4318 | } | |
4319 | ||
fa731587 PZ |
4320 | static void perf_event_init_userpage(struct perf_event *event) |
4321 | { | |
4322 | struct perf_event_mmap_page *userpg; | |
4323 | struct ring_buffer *rb; | |
4324 | ||
4325 | rcu_read_lock(); | |
4326 | rb = rcu_dereference(event->rb); | |
4327 | if (!rb) | |
4328 | goto unlock; | |
4329 | ||
4330 | userpg = rb->user_page; | |
4331 | ||
4332 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4333 | userpg->cap_bit0_is_deprecated = 1; | |
4334 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4335 | userpg->data_offset = PAGE_SIZE; |
4336 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4337 | |
4338 | unlock: | |
4339 | rcu_read_unlock(); | |
4340 | } | |
4341 | ||
c1317ec2 AL |
4342 | void __weak arch_perf_update_userpage( |
4343 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4344 | { |
4345 | } | |
4346 | ||
38ff667b PZ |
4347 | /* |
4348 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4349 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4350 | * code calls this from NMI context. | |
4351 | */ | |
cdd6c482 | 4352 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4353 | { |
cdd6c482 | 4354 | struct perf_event_mmap_page *userpg; |
76369139 | 4355 | struct ring_buffer *rb; |
e3f3541c | 4356 | u64 enabled, running, now; |
38ff667b PZ |
4357 | |
4358 | rcu_read_lock(); | |
5ec4c599 PZ |
4359 | rb = rcu_dereference(event->rb); |
4360 | if (!rb) | |
4361 | goto unlock; | |
4362 | ||
0d641208 EM |
4363 | /* |
4364 | * compute total_time_enabled, total_time_running | |
4365 | * based on snapshot values taken when the event | |
4366 | * was last scheduled in. | |
4367 | * | |
4368 | * we cannot simply called update_context_time() | |
4369 | * because of locking issue as we can be called in | |
4370 | * NMI context | |
4371 | */ | |
e3f3541c | 4372 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4373 | |
76369139 | 4374 | userpg = rb->user_page; |
7b732a75 PZ |
4375 | /* |
4376 | * Disable preemption so as to not let the corresponding user-space | |
4377 | * spin too long if we get preempted. | |
4378 | */ | |
4379 | preempt_disable(); | |
37d81828 | 4380 | ++userpg->lock; |
92f22a38 | 4381 | barrier(); |
cdd6c482 | 4382 | userpg->index = perf_event_index(event); |
b5e58793 | 4383 | userpg->offset = perf_event_count(event); |
365a4038 | 4384 | if (userpg->index) |
e7850595 | 4385 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4386 | |
0d641208 | 4387 | userpg->time_enabled = enabled + |
cdd6c482 | 4388 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4389 | |
0d641208 | 4390 | userpg->time_running = running + |
cdd6c482 | 4391 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4392 | |
c1317ec2 | 4393 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4394 | |
92f22a38 | 4395 | barrier(); |
37d81828 | 4396 | ++userpg->lock; |
7b732a75 | 4397 | preempt_enable(); |
38ff667b | 4398 | unlock: |
7b732a75 | 4399 | rcu_read_unlock(); |
37d81828 PM |
4400 | } |
4401 | ||
906010b2 PZ |
4402 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4403 | { | |
4404 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4405 | struct ring_buffer *rb; |
906010b2 PZ |
4406 | int ret = VM_FAULT_SIGBUS; |
4407 | ||
4408 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4409 | if (vmf->pgoff == 0) | |
4410 | ret = 0; | |
4411 | return ret; | |
4412 | } | |
4413 | ||
4414 | rcu_read_lock(); | |
76369139 FW |
4415 | rb = rcu_dereference(event->rb); |
4416 | if (!rb) | |
906010b2 PZ |
4417 | goto unlock; |
4418 | ||
4419 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4420 | goto unlock; | |
4421 | ||
76369139 | 4422 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4423 | if (!vmf->page) |
4424 | goto unlock; | |
4425 | ||
4426 | get_page(vmf->page); | |
4427 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4428 | vmf->page->index = vmf->pgoff; | |
4429 | ||
4430 | ret = 0; | |
4431 | unlock: | |
4432 | rcu_read_unlock(); | |
4433 | ||
4434 | return ret; | |
4435 | } | |
4436 | ||
10c6db11 PZ |
4437 | static void ring_buffer_attach(struct perf_event *event, |
4438 | struct ring_buffer *rb) | |
4439 | { | |
b69cf536 | 4440 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4441 | unsigned long flags; |
4442 | ||
b69cf536 PZ |
4443 | if (event->rb) { |
4444 | /* | |
4445 | * Should be impossible, we set this when removing | |
4446 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4447 | */ | |
4448 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4449 | |
b69cf536 | 4450 | old_rb = event->rb; |
b69cf536 PZ |
4451 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4452 | list_del_rcu(&event->rb_entry); | |
4453 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4454 | |
2f993cf0 ON |
4455 | event->rcu_batches = get_state_synchronize_rcu(); |
4456 | event->rcu_pending = 1; | |
b69cf536 | 4457 | } |
10c6db11 | 4458 | |
b69cf536 | 4459 | if (rb) { |
2f993cf0 ON |
4460 | if (event->rcu_pending) { |
4461 | cond_synchronize_rcu(event->rcu_batches); | |
4462 | event->rcu_pending = 0; | |
4463 | } | |
4464 | ||
b69cf536 PZ |
4465 | spin_lock_irqsave(&rb->event_lock, flags); |
4466 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4467 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4468 | } | |
4469 | ||
4470 | rcu_assign_pointer(event->rb, rb); | |
4471 | ||
4472 | if (old_rb) { | |
4473 | ring_buffer_put(old_rb); | |
4474 | /* | |
4475 | * Since we detached before setting the new rb, so that we | |
4476 | * could attach the new rb, we could have missed a wakeup. | |
4477 | * Provide it now. | |
4478 | */ | |
4479 | wake_up_all(&event->waitq); | |
4480 | } | |
10c6db11 PZ |
4481 | } |
4482 | ||
4483 | static void ring_buffer_wakeup(struct perf_event *event) | |
4484 | { | |
4485 | struct ring_buffer *rb; | |
4486 | ||
4487 | rcu_read_lock(); | |
4488 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4489 | if (rb) { |
4490 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4491 | wake_up_all(&event->waitq); | |
4492 | } | |
10c6db11 PZ |
4493 | rcu_read_unlock(); |
4494 | } | |
4495 | ||
fdc26706 | 4496 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4497 | { |
76369139 | 4498 | struct ring_buffer *rb; |
7b732a75 | 4499 | |
ac9721f3 | 4500 | rcu_read_lock(); |
76369139 FW |
4501 | rb = rcu_dereference(event->rb); |
4502 | if (rb) { | |
4503 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4504 | rb = NULL; | |
ac9721f3 PZ |
4505 | } |
4506 | rcu_read_unlock(); | |
4507 | ||
76369139 | 4508 | return rb; |
ac9721f3 PZ |
4509 | } |
4510 | ||
fdc26706 | 4511 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4512 | { |
76369139 | 4513 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4514 | return; |
7b732a75 | 4515 | |
9bb5d40c | 4516 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4517 | |
76369139 | 4518 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4519 | } |
4520 | ||
4521 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4522 | { | |
cdd6c482 | 4523 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4524 | |
cdd6c482 | 4525 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4526 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4527 | |
45bfb2e5 PZ |
4528 | if (vma->vm_pgoff) |
4529 | atomic_inc(&event->rb->aux_mmap_count); | |
4530 | ||
1e0fb9ec AL |
4531 | if (event->pmu->event_mapped) |
4532 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4533 | } |
4534 | ||
9bb5d40c PZ |
4535 | /* |
4536 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4537 | * event, or through other events by use of perf_event_set_output(). | |
4538 | * | |
4539 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4540 | * the buffer here, where we still have a VM context. This means we need | |
4541 | * to detach all events redirecting to us. | |
4542 | */ | |
7b732a75 PZ |
4543 | static void perf_mmap_close(struct vm_area_struct *vma) |
4544 | { | |
cdd6c482 | 4545 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4546 | |
b69cf536 | 4547 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4548 | struct user_struct *mmap_user = rb->mmap_user; |
4549 | int mmap_locked = rb->mmap_locked; | |
4550 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4551 | |
1e0fb9ec AL |
4552 | if (event->pmu->event_unmapped) |
4553 | event->pmu->event_unmapped(event); | |
4554 | ||
45bfb2e5 PZ |
4555 | /* |
4556 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4557 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4558 | * serialize with perf_mmap here. | |
4559 | */ | |
4560 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4561 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4562 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4563 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4564 | ||
4565 | rb_free_aux(rb); | |
4566 | mutex_unlock(&event->mmap_mutex); | |
4567 | } | |
4568 | ||
9bb5d40c PZ |
4569 | atomic_dec(&rb->mmap_count); |
4570 | ||
4571 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4572 | goto out_put; |
9bb5d40c | 4573 | |
b69cf536 | 4574 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4575 | mutex_unlock(&event->mmap_mutex); |
4576 | ||
4577 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4578 | if (atomic_read(&rb->mmap_count)) |
4579 | goto out_put; | |
ac9721f3 | 4580 | |
9bb5d40c PZ |
4581 | /* |
4582 | * No other mmap()s, detach from all other events that might redirect | |
4583 | * into the now unreachable buffer. Somewhat complicated by the | |
4584 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4585 | */ | |
4586 | again: | |
4587 | rcu_read_lock(); | |
4588 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4589 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4590 | /* | |
4591 | * This event is en-route to free_event() which will | |
4592 | * detach it and remove it from the list. | |
4593 | */ | |
4594 | continue; | |
4595 | } | |
4596 | rcu_read_unlock(); | |
789f90fc | 4597 | |
9bb5d40c PZ |
4598 | mutex_lock(&event->mmap_mutex); |
4599 | /* | |
4600 | * Check we didn't race with perf_event_set_output() which can | |
4601 | * swizzle the rb from under us while we were waiting to | |
4602 | * acquire mmap_mutex. | |
4603 | * | |
4604 | * If we find a different rb; ignore this event, a next | |
4605 | * iteration will no longer find it on the list. We have to | |
4606 | * still restart the iteration to make sure we're not now | |
4607 | * iterating the wrong list. | |
4608 | */ | |
b69cf536 PZ |
4609 | if (event->rb == rb) |
4610 | ring_buffer_attach(event, NULL); | |
4611 | ||
cdd6c482 | 4612 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4613 | put_event(event); |
ac9721f3 | 4614 | |
9bb5d40c PZ |
4615 | /* |
4616 | * Restart the iteration; either we're on the wrong list or | |
4617 | * destroyed its integrity by doing a deletion. | |
4618 | */ | |
4619 | goto again; | |
7b732a75 | 4620 | } |
9bb5d40c PZ |
4621 | rcu_read_unlock(); |
4622 | ||
4623 | /* | |
4624 | * It could be there's still a few 0-ref events on the list; they'll | |
4625 | * get cleaned up by free_event() -- they'll also still have their | |
4626 | * ref on the rb and will free it whenever they are done with it. | |
4627 | * | |
4628 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4629 | * undo the VM accounting. | |
4630 | */ | |
4631 | ||
4632 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4633 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4634 | free_uid(mmap_user); | |
4635 | ||
b69cf536 | 4636 | out_put: |
9bb5d40c | 4637 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4638 | } |
4639 | ||
f0f37e2f | 4640 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4641 | .open = perf_mmap_open, |
45bfb2e5 | 4642 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4643 | .fault = perf_mmap_fault, |
4644 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4645 | }; |
4646 | ||
4647 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4648 | { | |
cdd6c482 | 4649 | struct perf_event *event = file->private_data; |
22a4f650 | 4650 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4651 | struct user_struct *user = current_user(); |
22a4f650 | 4652 | unsigned long locked, lock_limit; |
45bfb2e5 | 4653 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4654 | unsigned long vma_size; |
4655 | unsigned long nr_pages; | |
45bfb2e5 | 4656 | long user_extra = 0, extra = 0; |
d57e34fd | 4657 | int ret = 0, flags = 0; |
37d81828 | 4658 | |
c7920614 PZ |
4659 | /* |
4660 | * Don't allow mmap() of inherited per-task counters. This would | |
4661 | * create a performance issue due to all children writing to the | |
76369139 | 4662 | * same rb. |
c7920614 PZ |
4663 | */ |
4664 | if (event->cpu == -1 && event->attr.inherit) | |
4665 | return -EINVAL; | |
4666 | ||
43a21ea8 | 4667 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4668 | return -EINVAL; |
7b732a75 PZ |
4669 | |
4670 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4671 | |
4672 | if (vma->vm_pgoff == 0) { | |
4673 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4674 | } else { | |
4675 | /* | |
4676 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4677 | * mapped, all subsequent mappings should have the same size | |
4678 | * and offset. Must be above the normal perf buffer. | |
4679 | */ | |
4680 | u64 aux_offset, aux_size; | |
4681 | ||
4682 | if (!event->rb) | |
4683 | return -EINVAL; | |
4684 | ||
4685 | nr_pages = vma_size / PAGE_SIZE; | |
4686 | ||
4687 | mutex_lock(&event->mmap_mutex); | |
4688 | ret = -EINVAL; | |
4689 | ||
4690 | rb = event->rb; | |
4691 | if (!rb) | |
4692 | goto aux_unlock; | |
4693 | ||
4694 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4695 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4696 | ||
4697 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4698 | goto aux_unlock; | |
4699 | ||
4700 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4701 | goto aux_unlock; | |
4702 | ||
4703 | /* already mapped with a different offset */ | |
4704 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4705 | goto aux_unlock; | |
4706 | ||
4707 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4708 | goto aux_unlock; | |
4709 | ||
4710 | /* already mapped with a different size */ | |
4711 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4712 | goto aux_unlock; | |
4713 | ||
4714 | if (!is_power_of_2(nr_pages)) | |
4715 | goto aux_unlock; | |
4716 | ||
4717 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4718 | goto aux_unlock; | |
4719 | ||
4720 | if (rb_has_aux(rb)) { | |
4721 | atomic_inc(&rb->aux_mmap_count); | |
4722 | ret = 0; | |
4723 | goto unlock; | |
4724 | } | |
4725 | ||
4726 | atomic_set(&rb->aux_mmap_count, 1); | |
4727 | user_extra = nr_pages; | |
4728 | ||
4729 | goto accounting; | |
4730 | } | |
7b732a75 | 4731 | |
7730d865 | 4732 | /* |
76369139 | 4733 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4734 | * can do bitmasks instead of modulo. |
4735 | */ | |
2ed11312 | 4736 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4737 | return -EINVAL; |
4738 | ||
7b732a75 | 4739 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4740 | return -EINVAL; |
4741 | ||
cdd6c482 | 4742 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4743 | again: |
cdd6c482 | 4744 | mutex_lock(&event->mmap_mutex); |
76369139 | 4745 | if (event->rb) { |
9bb5d40c | 4746 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4747 | ret = -EINVAL; |
9bb5d40c PZ |
4748 | goto unlock; |
4749 | } | |
4750 | ||
4751 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4752 | /* | |
4753 | * Raced against perf_mmap_close() through | |
4754 | * perf_event_set_output(). Try again, hope for better | |
4755 | * luck. | |
4756 | */ | |
4757 | mutex_unlock(&event->mmap_mutex); | |
4758 | goto again; | |
4759 | } | |
4760 | ||
ebb3c4c4 PZ |
4761 | goto unlock; |
4762 | } | |
4763 | ||
789f90fc | 4764 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4765 | |
4766 | accounting: | |
cdd6c482 | 4767 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4768 | |
4769 | /* | |
4770 | * Increase the limit linearly with more CPUs: | |
4771 | */ | |
4772 | user_lock_limit *= num_online_cpus(); | |
4773 | ||
789f90fc | 4774 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4775 | |
789f90fc PZ |
4776 | if (user_locked > user_lock_limit) |
4777 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4778 | |
78d7d407 | 4779 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4780 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4781 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4782 | |
459ec28a IM |
4783 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4784 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4785 | ret = -EPERM; |
4786 | goto unlock; | |
4787 | } | |
7b732a75 | 4788 | |
45bfb2e5 | 4789 | WARN_ON(!rb && event->rb); |
906010b2 | 4790 | |
d57e34fd | 4791 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4792 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4793 | |
76369139 | 4794 | if (!rb) { |
45bfb2e5 PZ |
4795 | rb = rb_alloc(nr_pages, |
4796 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4797 | event->cpu, flags); | |
26cb63ad | 4798 | |
45bfb2e5 PZ |
4799 | if (!rb) { |
4800 | ret = -ENOMEM; | |
4801 | goto unlock; | |
4802 | } | |
43a21ea8 | 4803 | |
45bfb2e5 PZ |
4804 | atomic_set(&rb->mmap_count, 1); |
4805 | rb->mmap_user = get_current_user(); | |
4806 | rb->mmap_locked = extra; | |
26cb63ad | 4807 | |
45bfb2e5 | 4808 | ring_buffer_attach(event, rb); |
ac9721f3 | 4809 | |
45bfb2e5 PZ |
4810 | perf_event_init_userpage(event); |
4811 | perf_event_update_userpage(event); | |
4812 | } else { | |
1a594131 AS |
4813 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4814 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4815 | if (!ret) |
4816 | rb->aux_mmap_locked = extra; | |
4817 | } | |
9a0f05cb | 4818 | |
ebb3c4c4 | 4819 | unlock: |
45bfb2e5 PZ |
4820 | if (!ret) { |
4821 | atomic_long_add(user_extra, &user->locked_vm); | |
4822 | vma->vm_mm->pinned_vm += extra; | |
4823 | ||
ac9721f3 | 4824 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4825 | } else if (rb) { |
4826 | atomic_dec(&rb->mmap_count); | |
4827 | } | |
4828 | aux_unlock: | |
cdd6c482 | 4829 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4830 | |
9bb5d40c PZ |
4831 | /* |
4832 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4833 | * vma. | |
4834 | */ | |
26cb63ad | 4835 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4836 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4837 | |
1e0fb9ec AL |
4838 | if (event->pmu->event_mapped) |
4839 | event->pmu->event_mapped(event); | |
4840 | ||
7b732a75 | 4841 | return ret; |
37d81828 PM |
4842 | } |
4843 | ||
3c446b3d PZ |
4844 | static int perf_fasync(int fd, struct file *filp, int on) |
4845 | { | |
496ad9aa | 4846 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4847 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4848 | int retval; |
4849 | ||
4850 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4851 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4852 | mutex_unlock(&inode->i_mutex); |
4853 | ||
4854 | if (retval < 0) | |
4855 | return retval; | |
4856 | ||
4857 | return 0; | |
4858 | } | |
4859 | ||
0793a61d | 4860 | static const struct file_operations perf_fops = { |
3326c1ce | 4861 | .llseek = no_llseek, |
0793a61d TG |
4862 | .release = perf_release, |
4863 | .read = perf_read, | |
4864 | .poll = perf_poll, | |
d859e29f | 4865 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4866 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4867 | .mmap = perf_mmap, |
3c446b3d | 4868 | .fasync = perf_fasync, |
0793a61d TG |
4869 | }; |
4870 | ||
925d519a | 4871 | /* |
cdd6c482 | 4872 | * Perf event wakeup |
925d519a PZ |
4873 | * |
4874 | * If there's data, ensure we set the poll() state and publish everything | |
4875 | * to user-space before waking everybody up. | |
4876 | */ | |
4877 | ||
fed66e2c PZ |
4878 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4879 | { | |
4880 | /* only the parent has fasync state */ | |
4881 | if (event->parent) | |
4882 | event = event->parent; | |
4883 | return &event->fasync; | |
4884 | } | |
4885 | ||
cdd6c482 | 4886 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4887 | { |
10c6db11 | 4888 | ring_buffer_wakeup(event); |
4c9e2542 | 4889 | |
cdd6c482 | 4890 | if (event->pending_kill) { |
fed66e2c | 4891 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4892 | event->pending_kill = 0; |
4c9e2542 | 4893 | } |
925d519a PZ |
4894 | } |
4895 | ||
e360adbe | 4896 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4897 | { |
cdd6c482 IM |
4898 | struct perf_event *event = container_of(entry, |
4899 | struct perf_event, pending); | |
d525211f PZ |
4900 | int rctx; |
4901 | ||
4902 | rctx = perf_swevent_get_recursion_context(); | |
4903 | /* | |
4904 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4905 | * and we won't recurse 'further'. | |
4906 | */ | |
79f14641 | 4907 | |
cdd6c482 IM |
4908 | if (event->pending_disable) { |
4909 | event->pending_disable = 0; | |
fae3fde6 | 4910 | perf_event_disable_local(event); |
79f14641 PZ |
4911 | } |
4912 | ||
cdd6c482 IM |
4913 | if (event->pending_wakeup) { |
4914 | event->pending_wakeup = 0; | |
4915 | perf_event_wakeup(event); | |
79f14641 | 4916 | } |
d525211f PZ |
4917 | |
4918 | if (rctx >= 0) | |
4919 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4920 | } |
4921 | ||
39447b38 ZY |
4922 | /* |
4923 | * We assume there is only KVM supporting the callbacks. | |
4924 | * Later on, we might change it to a list if there is | |
4925 | * another virtualization implementation supporting the callbacks. | |
4926 | */ | |
4927 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4928 | ||
4929 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4930 | { | |
4931 | perf_guest_cbs = cbs; | |
4932 | return 0; | |
4933 | } | |
4934 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4935 | ||
4936 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4937 | { | |
4938 | perf_guest_cbs = NULL; | |
4939 | return 0; | |
4940 | } | |
4941 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4942 | ||
4018994f JO |
4943 | static void |
4944 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4945 | struct pt_regs *regs, u64 mask) | |
4946 | { | |
4947 | int bit; | |
4948 | ||
4949 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4950 | sizeof(mask) * BITS_PER_BYTE) { | |
4951 | u64 val; | |
4952 | ||
4953 | val = perf_reg_value(regs, bit); | |
4954 | perf_output_put(handle, val); | |
4955 | } | |
4956 | } | |
4957 | ||
60e2364e | 4958 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4959 | struct pt_regs *regs, |
4960 | struct pt_regs *regs_user_copy) | |
4018994f | 4961 | { |
88a7c26a AL |
4962 | if (user_mode(regs)) { |
4963 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4964 | regs_user->regs = regs; |
88a7c26a AL |
4965 | } else if (current->mm) { |
4966 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4967 | } else { |
4968 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4969 | regs_user->regs = NULL; | |
4018994f JO |
4970 | } |
4971 | } | |
4972 | ||
60e2364e SE |
4973 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
4974 | struct pt_regs *regs) | |
4975 | { | |
4976 | regs_intr->regs = regs; | |
4977 | regs_intr->abi = perf_reg_abi(current); | |
4978 | } | |
4979 | ||
4980 | ||
c5ebcedb JO |
4981 | /* |
4982 | * Get remaining task size from user stack pointer. | |
4983 | * | |
4984 | * It'd be better to take stack vma map and limit this more | |
4985 | * precisly, but there's no way to get it safely under interrupt, | |
4986 | * so using TASK_SIZE as limit. | |
4987 | */ | |
4988 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
4989 | { | |
4990 | unsigned long addr = perf_user_stack_pointer(regs); | |
4991 | ||
4992 | if (!addr || addr >= TASK_SIZE) | |
4993 | return 0; | |
4994 | ||
4995 | return TASK_SIZE - addr; | |
4996 | } | |
4997 | ||
4998 | static u16 | |
4999 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5000 | struct pt_regs *regs) | |
5001 | { | |
5002 | u64 task_size; | |
5003 | ||
5004 | /* No regs, no stack pointer, no dump. */ | |
5005 | if (!regs) | |
5006 | return 0; | |
5007 | ||
5008 | /* | |
5009 | * Check if we fit in with the requested stack size into the: | |
5010 | * - TASK_SIZE | |
5011 | * If we don't, we limit the size to the TASK_SIZE. | |
5012 | * | |
5013 | * - remaining sample size | |
5014 | * If we don't, we customize the stack size to | |
5015 | * fit in to the remaining sample size. | |
5016 | */ | |
5017 | ||
5018 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5019 | stack_size = min(stack_size, (u16) task_size); | |
5020 | ||
5021 | /* Current header size plus static size and dynamic size. */ | |
5022 | header_size += 2 * sizeof(u64); | |
5023 | ||
5024 | /* Do we fit in with the current stack dump size? */ | |
5025 | if ((u16) (header_size + stack_size) < header_size) { | |
5026 | /* | |
5027 | * If we overflow the maximum size for the sample, | |
5028 | * we customize the stack dump size to fit in. | |
5029 | */ | |
5030 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5031 | stack_size = round_up(stack_size, sizeof(u64)); | |
5032 | } | |
5033 | ||
5034 | return stack_size; | |
5035 | } | |
5036 | ||
5037 | static void | |
5038 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5039 | struct pt_regs *regs) | |
5040 | { | |
5041 | /* Case of a kernel thread, nothing to dump */ | |
5042 | if (!regs) { | |
5043 | u64 size = 0; | |
5044 | perf_output_put(handle, size); | |
5045 | } else { | |
5046 | unsigned long sp; | |
5047 | unsigned int rem; | |
5048 | u64 dyn_size; | |
5049 | ||
5050 | /* | |
5051 | * We dump: | |
5052 | * static size | |
5053 | * - the size requested by user or the best one we can fit | |
5054 | * in to the sample max size | |
5055 | * data | |
5056 | * - user stack dump data | |
5057 | * dynamic size | |
5058 | * - the actual dumped size | |
5059 | */ | |
5060 | ||
5061 | /* Static size. */ | |
5062 | perf_output_put(handle, dump_size); | |
5063 | ||
5064 | /* Data. */ | |
5065 | sp = perf_user_stack_pointer(regs); | |
5066 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5067 | dyn_size = dump_size - rem; | |
5068 | ||
5069 | perf_output_skip(handle, rem); | |
5070 | ||
5071 | /* Dynamic size. */ | |
5072 | perf_output_put(handle, dyn_size); | |
5073 | } | |
5074 | } | |
5075 | ||
c980d109 ACM |
5076 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5077 | struct perf_sample_data *data, | |
5078 | struct perf_event *event) | |
6844c09d ACM |
5079 | { |
5080 | u64 sample_type = event->attr.sample_type; | |
5081 | ||
5082 | data->type = sample_type; | |
5083 | header->size += event->id_header_size; | |
5084 | ||
5085 | if (sample_type & PERF_SAMPLE_TID) { | |
5086 | /* namespace issues */ | |
5087 | data->tid_entry.pid = perf_event_pid(event, current); | |
5088 | data->tid_entry.tid = perf_event_tid(event, current); | |
5089 | } | |
5090 | ||
5091 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5092 | data->time = perf_event_clock(event); |
6844c09d | 5093 | |
ff3d527c | 5094 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5095 | data->id = primary_event_id(event); |
5096 | ||
5097 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5098 | data->stream_id = event->id; | |
5099 | ||
5100 | if (sample_type & PERF_SAMPLE_CPU) { | |
5101 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5102 | data->cpu_entry.reserved = 0; | |
5103 | } | |
5104 | } | |
5105 | ||
76369139 FW |
5106 | void perf_event_header__init_id(struct perf_event_header *header, |
5107 | struct perf_sample_data *data, | |
5108 | struct perf_event *event) | |
c980d109 ACM |
5109 | { |
5110 | if (event->attr.sample_id_all) | |
5111 | __perf_event_header__init_id(header, data, event); | |
5112 | } | |
5113 | ||
5114 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5115 | struct perf_sample_data *data) | |
5116 | { | |
5117 | u64 sample_type = data->type; | |
5118 | ||
5119 | if (sample_type & PERF_SAMPLE_TID) | |
5120 | perf_output_put(handle, data->tid_entry); | |
5121 | ||
5122 | if (sample_type & PERF_SAMPLE_TIME) | |
5123 | perf_output_put(handle, data->time); | |
5124 | ||
5125 | if (sample_type & PERF_SAMPLE_ID) | |
5126 | perf_output_put(handle, data->id); | |
5127 | ||
5128 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5129 | perf_output_put(handle, data->stream_id); | |
5130 | ||
5131 | if (sample_type & PERF_SAMPLE_CPU) | |
5132 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5133 | |
5134 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5135 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5136 | } |
5137 | ||
76369139 FW |
5138 | void perf_event__output_id_sample(struct perf_event *event, |
5139 | struct perf_output_handle *handle, | |
5140 | struct perf_sample_data *sample) | |
c980d109 ACM |
5141 | { |
5142 | if (event->attr.sample_id_all) | |
5143 | __perf_event__output_id_sample(handle, sample); | |
5144 | } | |
5145 | ||
3dab77fb | 5146 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5147 | struct perf_event *event, |
5148 | u64 enabled, u64 running) | |
3dab77fb | 5149 | { |
cdd6c482 | 5150 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5151 | u64 values[4]; |
5152 | int n = 0; | |
5153 | ||
b5e58793 | 5154 | values[n++] = perf_event_count(event); |
3dab77fb | 5155 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5156 | values[n++] = enabled + |
cdd6c482 | 5157 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5158 | } |
5159 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5160 | values[n++] = running + |
cdd6c482 | 5161 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5162 | } |
5163 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5164 | values[n++] = primary_event_id(event); |
3dab77fb | 5165 | |
76369139 | 5166 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5167 | } |
5168 | ||
5169 | /* | |
cdd6c482 | 5170 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5171 | */ |
5172 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5173 | struct perf_event *event, |
5174 | u64 enabled, u64 running) | |
3dab77fb | 5175 | { |
cdd6c482 IM |
5176 | struct perf_event *leader = event->group_leader, *sub; |
5177 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5178 | u64 values[5]; |
5179 | int n = 0; | |
5180 | ||
5181 | values[n++] = 1 + leader->nr_siblings; | |
5182 | ||
5183 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5184 | values[n++] = enabled; |
3dab77fb PZ |
5185 | |
5186 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5187 | values[n++] = running; |
3dab77fb | 5188 | |
cdd6c482 | 5189 | if (leader != event) |
3dab77fb PZ |
5190 | leader->pmu->read(leader); |
5191 | ||
b5e58793 | 5192 | values[n++] = perf_event_count(leader); |
3dab77fb | 5193 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5194 | values[n++] = primary_event_id(leader); |
3dab77fb | 5195 | |
76369139 | 5196 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5197 | |
65abc865 | 5198 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5199 | n = 0; |
5200 | ||
6f5ab001 JO |
5201 | if ((sub != event) && |
5202 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5203 | sub->pmu->read(sub); |
5204 | ||
b5e58793 | 5205 | values[n++] = perf_event_count(sub); |
3dab77fb | 5206 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5207 | values[n++] = primary_event_id(sub); |
3dab77fb | 5208 | |
76369139 | 5209 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5210 | } |
5211 | } | |
5212 | ||
eed01528 SE |
5213 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5214 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5215 | ||
3dab77fb | 5216 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5217 | struct perf_event *event) |
3dab77fb | 5218 | { |
e3f3541c | 5219 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5220 | u64 read_format = event->attr.read_format; |
5221 | ||
5222 | /* | |
5223 | * compute total_time_enabled, total_time_running | |
5224 | * based on snapshot values taken when the event | |
5225 | * was last scheduled in. | |
5226 | * | |
5227 | * we cannot simply called update_context_time() | |
5228 | * because of locking issue as we are called in | |
5229 | * NMI context | |
5230 | */ | |
c4794295 | 5231 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5232 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5233 | |
cdd6c482 | 5234 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5235 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5236 | else |
eed01528 | 5237 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5238 | } |
5239 | ||
5622f295 MM |
5240 | void perf_output_sample(struct perf_output_handle *handle, |
5241 | struct perf_event_header *header, | |
5242 | struct perf_sample_data *data, | |
cdd6c482 | 5243 | struct perf_event *event) |
5622f295 MM |
5244 | { |
5245 | u64 sample_type = data->type; | |
5246 | ||
5247 | perf_output_put(handle, *header); | |
5248 | ||
ff3d527c AH |
5249 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5250 | perf_output_put(handle, data->id); | |
5251 | ||
5622f295 MM |
5252 | if (sample_type & PERF_SAMPLE_IP) |
5253 | perf_output_put(handle, data->ip); | |
5254 | ||
5255 | if (sample_type & PERF_SAMPLE_TID) | |
5256 | perf_output_put(handle, data->tid_entry); | |
5257 | ||
5258 | if (sample_type & PERF_SAMPLE_TIME) | |
5259 | perf_output_put(handle, data->time); | |
5260 | ||
5261 | if (sample_type & PERF_SAMPLE_ADDR) | |
5262 | perf_output_put(handle, data->addr); | |
5263 | ||
5264 | if (sample_type & PERF_SAMPLE_ID) | |
5265 | perf_output_put(handle, data->id); | |
5266 | ||
5267 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5268 | perf_output_put(handle, data->stream_id); | |
5269 | ||
5270 | if (sample_type & PERF_SAMPLE_CPU) | |
5271 | perf_output_put(handle, data->cpu_entry); | |
5272 | ||
5273 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5274 | perf_output_put(handle, data->period); | |
5275 | ||
5276 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5277 | perf_output_read(handle, event); |
5622f295 MM |
5278 | |
5279 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5280 | if (data->callchain) { | |
5281 | int size = 1; | |
5282 | ||
5283 | if (data->callchain) | |
5284 | size += data->callchain->nr; | |
5285 | ||
5286 | size *= sizeof(u64); | |
5287 | ||
76369139 | 5288 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5289 | } else { |
5290 | u64 nr = 0; | |
5291 | perf_output_put(handle, nr); | |
5292 | } | |
5293 | } | |
5294 | ||
5295 | if (sample_type & PERF_SAMPLE_RAW) { | |
5296 | if (data->raw) { | |
fa128e6a AS |
5297 | u32 raw_size = data->raw->size; |
5298 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5299 | sizeof(u64)) - sizeof(u32); | |
5300 | u64 zero = 0; | |
5301 | ||
5302 | perf_output_put(handle, real_size); | |
5303 | __output_copy(handle, data->raw->data, raw_size); | |
5304 | if (real_size - raw_size) | |
5305 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5306 | } else { |
5307 | struct { | |
5308 | u32 size; | |
5309 | u32 data; | |
5310 | } raw = { | |
5311 | .size = sizeof(u32), | |
5312 | .data = 0, | |
5313 | }; | |
5314 | perf_output_put(handle, raw); | |
5315 | } | |
5316 | } | |
a7ac67ea | 5317 | |
bce38cd5 SE |
5318 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5319 | if (data->br_stack) { | |
5320 | size_t size; | |
5321 | ||
5322 | size = data->br_stack->nr | |
5323 | * sizeof(struct perf_branch_entry); | |
5324 | ||
5325 | perf_output_put(handle, data->br_stack->nr); | |
5326 | perf_output_copy(handle, data->br_stack->entries, size); | |
5327 | } else { | |
5328 | /* | |
5329 | * we always store at least the value of nr | |
5330 | */ | |
5331 | u64 nr = 0; | |
5332 | perf_output_put(handle, nr); | |
5333 | } | |
5334 | } | |
4018994f JO |
5335 | |
5336 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5337 | u64 abi = data->regs_user.abi; | |
5338 | ||
5339 | /* | |
5340 | * If there are no regs to dump, notice it through | |
5341 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5342 | */ | |
5343 | perf_output_put(handle, abi); | |
5344 | ||
5345 | if (abi) { | |
5346 | u64 mask = event->attr.sample_regs_user; | |
5347 | perf_output_sample_regs(handle, | |
5348 | data->regs_user.regs, | |
5349 | mask); | |
5350 | } | |
5351 | } | |
c5ebcedb | 5352 | |
a5cdd40c | 5353 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5354 | perf_output_sample_ustack(handle, |
5355 | data->stack_user_size, | |
5356 | data->regs_user.regs); | |
a5cdd40c | 5357 | } |
c3feedf2 AK |
5358 | |
5359 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5360 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5361 | |
5362 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5363 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5364 | |
fdfbbd07 AK |
5365 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5366 | perf_output_put(handle, data->txn); | |
5367 | ||
60e2364e SE |
5368 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5369 | u64 abi = data->regs_intr.abi; | |
5370 | /* | |
5371 | * If there are no regs to dump, notice it through | |
5372 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5373 | */ | |
5374 | perf_output_put(handle, abi); | |
5375 | ||
5376 | if (abi) { | |
5377 | u64 mask = event->attr.sample_regs_intr; | |
5378 | ||
5379 | perf_output_sample_regs(handle, | |
5380 | data->regs_intr.regs, | |
5381 | mask); | |
5382 | } | |
5383 | } | |
5384 | ||
a5cdd40c PZ |
5385 | if (!event->attr.watermark) { |
5386 | int wakeup_events = event->attr.wakeup_events; | |
5387 | ||
5388 | if (wakeup_events) { | |
5389 | struct ring_buffer *rb = handle->rb; | |
5390 | int events = local_inc_return(&rb->events); | |
5391 | ||
5392 | if (events >= wakeup_events) { | |
5393 | local_sub(wakeup_events, &rb->events); | |
5394 | local_inc(&rb->wakeup); | |
5395 | } | |
5396 | } | |
5397 | } | |
5622f295 MM |
5398 | } |
5399 | ||
5400 | void perf_prepare_sample(struct perf_event_header *header, | |
5401 | struct perf_sample_data *data, | |
cdd6c482 | 5402 | struct perf_event *event, |
5622f295 | 5403 | struct pt_regs *regs) |
7b732a75 | 5404 | { |
cdd6c482 | 5405 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5406 | |
cdd6c482 | 5407 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5408 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5409 | |
5410 | header->misc = 0; | |
5411 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5412 | |
c980d109 | 5413 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5414 | |
c320c7b7 | 5415 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5416 | data->ip = perf_instruction_pointer(regs); |
5417 | ||
b23f3325 | 5418 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5419 | int size = 1; |
394ee076 | 5420 | |
e6dab5ff | 5421 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5422 | |
5423 | if (data->callchain) | |
5424 | size += data->callchain->nr; | |
5425 | ||
5426 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5427 | } |
5428 | ||
3a43ce68 | 5429 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5430 | int size = sizeof(u32); |
5431 | ||
5432 | if (data->raw) | |
5433 | size += data->raw->size; | |
5434 | else | |
5435 | size += sizeof(u32); | |
5436 | ||
fa128e6a | 5437 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5438 | } |
bce38cd5 SE |
5439 | |
5440 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5441 | int size = sizeof(u64); /* nr */ | |
5442 | if (data->br_stack) { | |
5443 | size += data->br_stack->nr | |
5444 | * sizeof(struct perf_branch_entry); | |
5445 | } | |
5446 | header->size += size; | |
5447 | } | |
4018994f | 5448 | |
2565711f | 5449 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5450 | perf_sample_regs_user(&data->regs_user, regs, |
5451 | &data->regs_user_copy); | |
2565711f | 5452 | |
4018994f JO |
5453 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5454 | /* regs dump ABI info */ | |
5455 | int size = sizeof(u64); | |
5456 | ||
4018994f JO |
5457 | if (data->regs_user.regs) { |
5458 | u64 mask = event->attr.sample_regs_user; | |
5459 | size += hweight64(mask) * sizeof(u64); | |
5460 | } | |
5461 | ||
5462 | header->size += size; | |
5463 | } | |
c5ebcedb JO |
5464 | |
5465 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5466 | /* | |
5467 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5468 | * processed as the last one or have additional check added | |
5469 | * in case new sample type is added, because we could eat | |
5470 | * up the rest of the sample size. | |
5471 | */ | |
c5ebcedb JO |
5472 | u16 stack_size = event->attr.sample_stack_user; |
5473 | u16 size = sizeof(u64); | |
5474 | ||
c5ebcedb | 5475 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5476 | data->regs_user.regs); |
c5ebcedb JO |
5477 | |
5478 | /* | |
5479 | * If there is something to dump, add space for the dump | |
5480 | * itself and for the field that tells the dynamic size, | |
5481 | * which is how many have been actually dumped. | |
5482 | */ | |
5483 | if (stack_size) | |
5484 | size += sizeof(u64) + stack_size; | |
5485 | ||
5486 | data->stack_user_size = stack_size; | |
5487 | header->size += size; | |
5488 | } | |
60e2364e SE |
5489 | |
5490 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5491 | /* regs dump ABI info */ | |
5492 | int size = sizeof(u64); | |
5493 | ||
5494 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5495 | ||
5496 | if (data->regs_intr.regs) { | |
5497 | u64 mask = event->attr.sample_regs_intr; | |
5498 | ||
5499 | size += hweight64(mask) * sizeof(u64); | |
5500 | } | |
5501 | ||
5502 | header->size += size; | |
5503 | } | |
5622f295 | 5504 | } |
7f453c24 | 5505 | |
21509084 YZ |
5506 | void perf_event_output(struct perf_event *event, |
5507 | struct perf_sample_data *data, | |
5508 | struct pt_regs *regs) | |
5622f295 MM |
5509 | { |
5510 | struct perf_output_handle handle; | |
5511 | struct perf_event_header header; | |
689802b2 | 5512 | |
927c7a9e FW |
5513 | /* protect the callchain buffers */ |
5514 | rcu_read_lock(); | |
5515 | ||
cdd6c482 | 5516 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5517 | |
a7ac67ea | 5518 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5519 | goto exit; |
0322cd6e | 5520 | |
cdd6c482 | 5521 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5522 | |
8a057d84 | 5523 | perf_output_end(&handle); |
927c7a9e FW |
5524 | |
5525 | exit: | |
5526 | rcu_read_unlock(); | |
0322cd6e PZ |
5527 | } |
5528 | ||
38b200d6 | 5529 | /* |
cdd6c482 | 5530 | * read event_id |
38b200d6 PZ |
5531 | */ |
5532 | ||
5533 | struct perf_read_event { | |
5534 | struct perf_event_header header; | |
5535 | ||
5536 | u32 pid; | |
5537 | u32 tid; | |
38b200d6 PZ |
5538 | }; |
5539 | ||
5540 | static void | |
cdd6c482 | 5541 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5542 | struct task_struct *task) |
5543 | { | |
5544 | struct perf_output_handle handle; | |
c980d109 | 5545 | struct perf_sample_data sample; |
dfc65094 | 5546 | struct perf_read_event read_event = { |
38b200d6 | 5547 | .header = { |
cdd6c482 | 5548 | .type = PERF_RECORD_READ, |
38b200d6 | 5549 | .misc = 0, |
c320c7b7 | 5550 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5551 | }, |
cdd6c482 IM |
5552 | .pid = perf_event_pid(event, task), |
5553 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5554 | }; |
3dab77fb | 5555 | int ret; |
38b200d6 | 5556 | |
c980d109 | 5557 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5558 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5559 | if (ret) |
5560 | return; | |
5561 | ||
dfc65094 | 5562 | perf_output_put(&handle, read_event); |
cdd6c482 | 5563 | perf_output_read(&handle, event); |
c980d109 | 5564 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5565 | |
38b200d6 PZ |
5566 | perf_output_end(&handle); |
5567 | } | |
5568 | ||
52d857a8 JO |
5569 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5570 | ||
5571 | static void | |
5572 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5573 | perf_event_aux_output_cb output, |
5574 | void *data) | |
5575 | { | |
5576 | struct perf_event *event; | |
5577 | ||
5578 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5579 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5580 | continue; | |
5581 | if (!event_filter_match(event)) | |
5582 | continue; | |
67516844 | 5583 | output(event, data); |
52d857a8 JO |
5584 | } |
5585 | } | |
5586 | ||
4e93ad60 JO |
5587 | static void |
5588 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5589 | struct perf_event_context *task_ctx) | |
5590 | { | |
5591 | rcu_read_lock(); | |
5592 | preempt_disable(); | |
5593 | perf_event_aux_ctx(task_ctx, output, data); | |
5594 | preempt_enable(); | |
5595 | rcu_read_unlock(); | |
5596 | } | |
5597 | ||
52d857a8 | 5598 | static void |
67516844 | 5599 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5600 | struct perf_event_context *task_ctx) |
5601 | { | |
5602 | struct perf_cpu_context *cpuctx; | |
5603 | struct perf_event_context *ctx; | |
5604 | struct pmu *pmu; | |
5605 | int ctxn; | |
5606 | ||
4e93ad60 JO |
5607 | /* |
5608 | * If we have task_ctx != NULL we only notify | |
5609 | * the task context itself. The task_ctx is set | |
5610 | * only for EXIT events before releasing task | |
5611 | * context. | |
5612 | */ | |
5613 | if (task_ctx) { | |
5614 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5615 | return; | |
5616 | } | |
5617 | ||
52d857a8 JO |
5618 | rcu_read_lock(); |
5619 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5620 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5621 | if (cpuctx->unique_pmu != pmu) | |
5622 | goto next; | |
67516844 | 5623 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5624 | ctxn = pmu->task_ctx_nr; |
5625 | if (ctxn < 0) | |
5626 | goto next; | |
5627 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5628 | if (ctx) | |
67516844 | 5629 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5630 | next: |
5631 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5632 | } | |
52d857a8 JO |
5633 | rcu_read_unlock(); |
5634 | } | |
5635 | ||
60313ebe | 5636 | /* |
9f498cc5 PZ |
5637 | * task tracking -- fork/exit |
5638 | * | |
13d7a241 | 5639 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5640 | */ |
5641 | ||
9f498cc5 | 5642 | struct perf_task_event { |
3a80b4a3 | 5643 | struct task_struct *task; |
cdd6c482 | 5644 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5645 | |
5646 | struct { | |
5647 | struct perf_event_header header; | |
5648 | ||
5649 | u32 pid; | |
5650 | u32 ppid; | |
9f498cc5 PZ |
5651 | u32 tid; |
5652 | u32 ptid; | |
393b2ad8 | 5653 | u64 time; |
cdd6c482 | 5654 | } event_id; |
60313ebe PZ |
5655 | }; |
5656 | ||
67516844 JO |
5657 | static int perf_event_task_match(struct perf_event *event) |
5658 | { | |
13d7a241 SE |
5659 | return event->attr.comm || event->attr.mmap || |
5660 | event->attr.mmap2 || event->attr.mmap_data || | |
5661 | event->attr.task; | |
67516844 JO |
5662 | } |
5663 | ||
cdd6c482 | 5664 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5665 | void *data) |
60313ebe | 5666 | { |
52d857a8 | 5667 | struct perf_task_event *task_event = data; |
60313ebe | 5668 | struct perf_output_handle handle; |
c980d109 | 5669 | struct perf_sample_data sample; |
9f498cc5 | 5670 | struct task_struct *task = task_event->task; |
c980d109 | 5671 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5672 | |
67516844 JO |
5673 | if (!perf_event_task_match(event)) |
5674 | return; | |
5675 | ||
c980d109 | 5676 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5677 | |
c980d109 | 5678 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5679 | task_event->event_id.header.size); |
ef60777c | 5680 | if (ret) |
c980d109 | 5681 | goto out; |
60313ebe | 5682 | |
cdd6c482 IM |
5683 | task_event->event_id.pid = perf_event_pid(event, task); |
5684 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5685 | |
cdd6c482 IM |
5686 | task_event->event_id.tid = perf_event_tid(event, task); |
5687 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5688 | |
34f43927 PZ |
5689 | task_event->event_id.time = perf_event_clock(event); |
5690 | ||
cdd6c482 | 5691 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5692 | |
c980d109 ACM |
5693 | perf_event__output_id_sample(event, &handle, &sample); |
5694 | ||
60313ebe | 5695 | perf_output_end(&handle); |
c980d109 ACM |
5696 | out: |
5697 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5698 | } |
5699 | ||
cdd6c482 IM |
5700 | static void perf_event_task(struct task_struct *task, |
5701 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5702 | int new) |
60313ebe | 5703 | { |
9f498cc5 | 5704 | struct perf_task_event task_event; |
60313ebe | 5705 | |
cdd6c482 IM |
5706 | if (!atomic_read(&nr_comm_events) && |
5707 | !atomic_read(&nr_mmap_events) && | |
5708 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5709 | return; |
5710 | ||
9f498cc5 | 5711 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5712 | .task = task, |
5713 | .task_ctx = task_ctx, | |
cdd6c482 | 5714 | .event_id = { |
60313ebe | 5715 | .header = { |
cdd6c482 | 5716 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5717 | .misc = 0, |
cdd6c482 | 5718 | .size = sizeof(task_event.event_id), |
60313ebe | 5719 | }, |
573402db PZ |
5720 | /* .pid */ |
5721 | /* .ppid */ | |
9f498cc5 PZ |
5722 | /* .tid */ |
5723 | /* .ptid */ | |
34f43927 | 5724 | /* .time */ |
60313ebe PZ |
5725 | }, |
5726 | }; | |
5727 | ||
67516844 | 5728 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5729 | &task_event, |
5730 | task_ctx); | |
9f498cc5 PZ |
5731 | } |
5732 | ||
cdd6c482 | 5733 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5734 | { |
cdd6c482 | 5735 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5736 | } |
5737 | ||
8d1b2d93 PZ |
5738 | /* |
5739 | * comm tracking | |
5740 | */ | |
5741 | ||
5742 | struct perf_comm_event { | |
22a4f650 IM |
5743 | struct task_struct *task; |
5744 | char *comm; | |
8d1b2d93 PZ |
5745 | int comm_size; |
5746 | ||
5747 | struct { | |
5748 | struct perf_event_header header; | |
5749 | ||
5750 | u32 pid; | |
5751 | u32 tid; | |
cdd6c482 | 5752 | } event_id; |
8d1b2d93 PZ |
5753 | }; |
5754 | ||
67516844 JO |
5755 | static int perf_event_comm_match(struct perf_event *event) |
5756 | { | |
5757 | return event->attr.comm; | |
5758 | } | |
5759 | ||
cdd6c482 | 5760 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5761 | void *data) |
8d1b2d93 | 5762 | { |
52d857a8 | 5763 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5764 | struct perf_output_handle handle; |
c980d109 | 5765 | struct perf_sample_data sample; |
cdd6c482 | 5766 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5767 | int ret; |
5768 | ||
67516844 JO |
5769 | if (!perf_event_comm_match(event)) |
5770 | return; | |
5771 | ||
c980d109 ACM |
5772 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5773 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5774 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5775 | |
5776 | if (ret) | |
c980d109 | 5777 | goto out; |
8d1b2d93 | 5778 | |
cdd6c482 IM |
5779 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5780 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5781 | |
cdd6c482 | 5782 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5783 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5784 | comm_event->comm_size); |
c980d109 ACM |
5785 | |
5786 | perf_event__output_id_sample(event, &handle, &sample); | |
5787 | ||
8d1b2d93 | 5788 | perf_output_end(&handle); |
c980d109 ACM |
5789 | out: |
5790 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5791 | } |
5792 | ||
cdd6c482 | 5793 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5794 | { |
413ee3b4 | 5795 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5796 | unsigned int size; |
8d1b2d93 | 5797 | |
413ee3b4 | 5798 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5799 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5800 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5801 | |
5802 | comm_event->comm = comm; | |
5803 | comm_event->comm_size = size; | |
5804 | ||
cdd6c482 | 5805 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5806 | |
67516844 | 5807 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5808 | comm_event, |
5809 | NULL); | |
8d1b2d93 PZ |
5810 | } |
5811 | ||
82b89778 | 5812 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5813 | { |
9ee318a7 PZ |
5814 | struct perf_comm_event comm_event; |
5815 | ||
cdd6c482 | 5816 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5817 | return; |
a63eaf34 | 5818 | |
9ee318a7 | 5819 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5820 | .task = task, |
573402db PZ |
5821 | /* .comm */ |
5822 | /* .comm_size */ | |
cdd6c482 | 5823 | .event_id = { |
573402db | 5824 | .header = { |
cdd6c482 | 5825 | .type = PERF_RECORD_COMM, |
82b89778 | 5826 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5827 | /* .size */ |
5828 | }, | |
5829 | /* .pid */ | |
5830 | /* .tid */ | |
8d1b2d93 PZ |
5831 | }, |
5832 | }; | |
5833 | ||
cdd6c482 | 5834 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5835 | } |
5836 | ||
0a4a9391 PZ |
5837 | /* |
5838 | * mmap tracking | |
5839 | */ | |
5840 | ||
5841 | struct perf_mmap_event { | |
089dd79d PZ |
5842 | struct vm_area_struct *vma; |
5843 | ||
5844 | const char *file_name; | |
5845 | int file_size; | |
13d7a241 SE |
5846 | int maj, min; |
5847 | u64 ino; | |
5848 | u64 ino_generation; | |
f972eb63 | 5849 | u32 prot, flags; |
0a4a9391 PZ |
5850 | |
5851 | struct { | |
5852 | struct perf_event_header header; | |
5853 | ||
5854 | u32 pid; | |
5855 | u32 tid; | |
5856 | u64 start; | |
5857 | u64 len; | |
5858 | u64 pgoff; | |
cdd6c482 | 5859 | } event_id; |
0a4a9391 PZ |
5860 | }; |
5861 | ||
67516844 JO |
5862 | static int perf_event_mmap_match(struct perf_event *event, |
5863 | void *data) | |
5864 | { | |
5865 | struct perf_mmap_event *mmap_event = data; | |
5866 | struct vm_area_struct *vma = mmap_event->vma; | |
5867 | int executable = vma->vm_flags & VM_EXEC; | |
5868 | ||
5869 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5870 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5871 | } |
5872 | ||
cdd6c482 | 5873 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5874 | void *data) |
0a4a9391 | 5875 | { |
52d857a8 | 5876 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5877 | struct perf_output_handle handle; |
c980d109 | 5878 | struct perf_sample_data sample; |
cdd6c482 | 5879 | int size = mmap_event->event_id.header.size; |
c980d109 | 5880 | int ret; |
0a4a9391 | 5881 | |
67516844 JO |
5882 | if (!perf_event_mmap_match(event, data)) |
5883 | return; | |
5884 | ||
13d7a241 SE |
5885 | if (event->attr.mmap2) { |
5886 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5887 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5888 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5889 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5890 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5891 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5892 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5893 | } |
5894 | ||
c980d109 ACM |
5895 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5896 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5897 | mmap_event->event_id.header.size); |
0a4a9391 | 5898 | if (ret) |
c980d109 | 5899 | goto out; |
0a4a9391 | 5900 | |
cdd6c482 IM |
5901 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5902 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5903 | |
cdd6c482 | 5904 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5905 | |
5906 | if (event->attr.mmap2) { | |
5907 | perf_output_put(&handle, mmap_event->maj); | |
5908 | perf_output_put(&handle, mmap_event->min); | |
5909 | perf_output_put(&handle, mmap_event->ino); | |
5910 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5911 | perf_output_put(&handle, mmap_event->prot); |
5912 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5913 | } |
5914 | ||
76369139 | 5915 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5916 | mmap_event->file_size); |
c980d109 ACM |
5917 | |
5918 | perf_event__output_id_sample(event, &handle, &sample); | |
5919 | ||
78d613eb | 5920 | perf_output_end(&handle); |
c980d109 ACM |
5921 | out: |
5922 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5923 | } |
5924 | ||
cdd6c482 | 5925 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5926 | { |
089dd79d PZ |
5927 | struct vm_area_struct *vma = mmap_event->vma; |
5928 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5929 | int maj = 0, min = 0; |
5930 | u64 ino = 0, gen = 0; | |
f972eb63 | 5931 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5932 | unsigned int size; |
5933 | char tmp[16]; | |
5934 | char *buf = NULL; | |
2c42cfbf | 5935 | char *name; |
413ee3b4 | 5936 | |
0a4a9391 | 5937 | if (file) { |
13d7a241 SE |
5938 | struct inode *inode; |
5939 | dev_t dev; | |
3ea2f2b9 | 5940 | |
2c42cfbf | 5941 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5942 | if (!buf) { |
c7e548b4 ON |
5943 | name = "//enomem"; |
5944 | goto cpy_name; | |
0a4a9391 | 5945 | } |
413ee3b4 | 5946 | /* |
3ea2f2b9 | 5947 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5948 | * need to add enough zero bytes after the string to handle |
5949 | * the 64bit alignment we do later. | |
5950 | */ | |
9bf39ab2 | 5951 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5952 | if (IS_ERR(name)) { |
c7e548b4 ON |
5953 | name = "//toolong"; |
5954 | goto cpy_name; | |
0a4a9391 | 5955 | } |
13d7a241 SE |
5956 | inode = file_inode(vma->vm_file); |
5957 | dev = inode->i_sb->s_dev; | |
5958 | ino = inode->i_ino; | |
5959 | gen = inode->i_generation; | |
5960 | maj = MAJOR(dev); | |
5961 | min = MINOR(dev); | |
f972eb63 PZ |
5962 | |
5963 | if (vma->vm_flags & VM_READ) | |
5964 | prot |= PROT_READ; | |
5965 | if (vma->vm_flags & VM_WRITE) | |
5966 | prot |= PROT_WRITE; | |
5967 | if (vma->vm_flags & VM_EXEC) | |
5968 | prot |= PROT_EXEC; | |
5969 | ||
5970 | if (vma->vm_flags & VM_MAYSHARE) | |
5971 | flags = MAP_SHARED; | |
5972 | else | |
5973 | flags = MAP_PRIVATE; | |
5974 | ||
5975 | if (vma->vm_flags & VM_DENYWRITE) | |
5976 | flags |= MAP_DENYWRITE; | |
5977 | if (vma->vm_flags & VM_MAYEXEC) | |
5978 | flags |= MAP_EXECUTABLE; | |
5979 | if (vma->vm_flags & VM_LOCKED) | |
5980 | flags |= MAP_LOCKED; | |
5981 | if (vma->vm_flags & VM_HUGETLB) | |
5982 | flags |= MAP_HUGETLB; | |
5983 | ||
c7e548b4 | 5984 | goto got_name; |
0a4a9391 | 5985 | } else { |
fbe26abe JO |
5986 | if (vma->vm_ops && vma->vm_ops->name) { |
5987 | name = (char *) vma->vm_ops->name(vma); | |
5988 | if (name) | |
5989 | goto cpy_name; | |
5990 | } | |
5991 | ||
2c42cfbf | 5992 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
5993 | if (name) |
5994 | goto cpy_name; | |
089dd79d | 5995 | |
32c5fb7e | 5996 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 5997 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
5998 | name = "[heap]"; |
5999 | goto cpy_name; | |
32c5fb7e ON |
6000 | } |
6001 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6002 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6003 | name = "[stack]"; |
6004 | goto cpy_name; | |
089dd79d PZ |
6005 | } |
6006 | ||
c7e548b4 ON |
6007 | name = "//anon"; |
6008 | goto cpy_name; | |
0a4a9391 PZ |
6009 | } |
6010 | ||
c7e548b4 ON |
6011 | cpy_name: |
6012 | strlcpy(tmp, name, sizeof(tmp)); | |
6013 | name = tmp; | |
0a4a9391 | 6014 | got_name: |
2c42cfbf PZ |
6015 | /* |
6016 | * Since our buffer works in 8 byte units we need to align our string | |
6017 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6018 | * zero'd out to avoid leaking random bits to userspace. | |
6019 | */ | |
6020 | size = strlen(name)+1; | |
6021 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6022 | name[size++] = '\0'; | |
0a4a9391 PZ |
6023 | |
6024 | mmap_event->file_name = name; | |
6025 | mmap_event->file_size = size; | |
13d7a241 SE |
6026 | mmap_event->maj = maj; |
6027 | mmap_event->min = min; | |
6028 | mmap_event->ino = ino; | |
6029 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6030 | mmap_event->prot = prot; |
6031 | mmap_event->flags = flags; | |
0a4a9391 | 6032 | |
2fe85427 SE |
6033 | if (!(vma->vm_flags & VM_EXEC)) |
6034 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6035 | ||
cdd6c482 | 6036 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6037 | |
67516844 | 6038 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6039 | mmap_event, |
6040 | NULL); | |
665c2142 | 6041 | |
0a4a9391 PZ |
6042 | kfree(buf); |
6043 | } | |
6044 | ||
3af9e859 | 6045 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6046 | { |
9ee318a7 PZ |
6047 | struct perf_mmap_event mmap_event; |
6048 | ||
cdd6c482 | 6049 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6050 | return; |
6051 | ||
6052 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6053 | .vma = vma, |
573402db PZ |
6054 | /* .file_name */ |
6055 | /* .file_size */ | |
cdd6c482 | 6056 | .event_id = { |
573402db | 6057 | .header = { |
cdd6c482 | 6058 | .type = PERF_RECORD_MMAP, |
39447b38 | 6059 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6060 | /* .size */ |
6061 | }, | |
6062 | /* .pid */ | |
6063 | /* .tid */ | |
089dd79d PZ |
6064 | .start = vma->vm_start, |
6065 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6066 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6067 | }, |
13d7a241 SE |
6068 | /* .maj (attr_mmap2 only) */ |
6069 | /* .min (attr_mmap2 only) */ | |
6070 | /* .ino (attr_mmap2 only) */ | |
6071 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6072 | /* .prot (attr_mmap2 only) */ |
6073 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6074 | }; |
6075 | ||
cdd6c482 | 6076 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6077 | } |
6078 | ||
68db7e98 AS |
6079 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6080 | unsigned long size, u64 flags) | |
6081 | { | |
6082 | struct perf_output_handle handle; | |
6083 | struct perf_sample_data sample; | |
6084 | struct perf_aux_event { | |
6085 | struct perf_event_header header; | |
6086 | u64 offset; | |
6087 | u64 size; | |
6088 | u64 flags; | |
6089 | } rec = { | |
6090 | .header = { | |
6091 | .type = PERF_RECORD_AUX, | |
6092 | .misc = 0, | |
6093 | .size = sizeof(rec), | |
6094 | }, | |
6095 | .offset = head, | |
6096 | .size = size, | |
6097 | .flags = flags, | |
6098 | }; | |
6099 | int ret; | |
6100 | ||
6101 | perf_event_header__init_id(&rec.header, &sample, event); | |
6102 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6103 | ||
6104 | if (ret) | |
6105 | return; | |
6106 | ||
6107 | perf_output_put(&handle, rec); | |
6108 | perf_event__output_id_sample(event, &handle, &sample); | |
6109 | ||
6110 | perf_output_end(&handle); | |
6111 | } | |
6112 | ||
f38b0dbb KL |
6113 | /* |
6114 | * Lost/dropped samples logging | |
6115 | */ | |
6116 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6117 | { | |
6118 | struct perf_output_handle handle; | |
6119 | struct perf_sample_data sample; | |
6120 | int ret; | |
6121 | ||
6122 | struct { | |
6123 | struct perf_event_header header; | |
6124 | u64 lost; | |
6125 | } lost_samples_event = { | |
6126 | .header = { | |
6127 | .type = PERF_RECORD_LOST_SAMPLES, | |
6128 | .misc = 0, | |
6129 | .size = sizeof(lost_samples_event), | |
6130 | }, | |
6131 | .lost = lost, | |
6132 | }; | |
6133 | ||
6134 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6135 | ||
6136 | ret = perf_output_begin(&handle, event, | |
6137 | lost_samples_event.header.size); | |
6138 | if (ret) | |
6139 | return; | |
6140 | ||
6141 | perf_output_put(&handle, lost_samples_event); | |
6142 | perf_event__output_id_sample(event, &handle, &sample); | |
6143 | perf_output_end(&handle); | |
6144 | } | |
6145 | ||
45ac1403 AH |
6146 | /* |
6147 | * context_switch tracking | |
6148 | */ | |
6149 | ||
6150 | struct perf_switch_event { | |
6151 | struct task_struct *task; | |
6152 | struct task_struct *next_prev; | |
6153 | ||
6154 | struct { | |
6155 | struct perf_event_header header; | |
6156 | u32 next_prev_pid; | |
6157 | u32 next_prev_tid; | |
6158 | } event_id; | |
6159 | }; | |
6160 | ||
6161 | static int perf_event_switch_match(struct perf_event *event) | |
6162 | { | |
6163 | return event->attr.context_switch; | |
6164 | } | |
6165 | ||
6166 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6167 | { | |
6168 | struct perf_switch_event *se = data; | |
6169 | struct perf_output_handle handle; | |
6170 | struct perf_sample_data sample; | |
6171 | int ret; | |
6172 | ||
6173 | if (!perf_event_switch_match(event)) | |
6174 | return; | |
6175 | ||
6176 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6177 | if (event->ctx->task) { | |
6178 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6179 | se->event_id.header.size = sizeof(se->event_id.header); | |
6180 | } else { | |
6181 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6182 | se->event_id.header.size = sizeof(se->event_id); | |
6183 | se->event_id.next_prev_pid = | |
6184 | perf_event_pid(event, se->next_prev); | |
6185 | se->event_id.next_prev_tid = | |
6186 | perf_event_tid(event, se->next_prev); | |
6187 | } | |
6188 | ||
6189 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6190 | ||
6191 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6192 | if (ret) | |
6193 | return; | |
6194 | ||
6195 | if (event->ctx->task) | |
6196 | perf_output_put(&handle, se->event_id.header); | |
6197 | else | |
6198 | perf_output_put(&handle, se->event_id); | |
6199 | ||
6200 | perf_event__output_id_sample(event, &handle, &sample); | |
6201 | ||
6202 | perf_output_end(&handle); | |
6203 | } | |
6204 | ||
6205 | static void perf_event_switch(struct task_struct *task, | |
6206 | struct task_struct *next_prev, bool sched_in) | |
6207 | { | |
6208 | struct perf_switch_event switch_event; | |
6209 | ||
6210 | /* N.B. caller checks nr_switch_events != 0 */ | |
6211 | ||
6212 | switch_event = (struct perf_switch_event){ | |
6213 | .task = task, | |
6214 | .next_prev = next_prev, | |
6215 | .event_id = { | |
6216 | .header = { | |
6217 | /* .type */ | |
6218 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6219 | /* .size */ | |
6220 | }, | |
6221 | /* .next_prev_pid */ | |
6222 | /* .next_prev_tid */ | |
6223 | }, | |
6224 | }; | |
6225 | ||
6226 | perf_event_aux(perf_event_switch_output, | |
6227 | &switch_event, | |
6228 | NULL); | |
6229 | } | |
6230 | ||
a78ac325 PZ |
6231 | /* |
6232 | * IRQ throttle logging | |
6233 | */ | |
6234 | ||
cdd6c482 | 6235 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6236 | { |
6237 | struct perf_output_handle handle; | |
c980d109 | 6238 | struct perf_sample_data sample; |
a78ac325 PZ |
6239 | int ret; |
6240 | ||
6241 | struct { | |
6242 | struct perf_event_header header; | |
6243 | u64 time; | |
cca3f454 | 6244 | u64 id; |
7f453c24 | 6245 | u64 stream_id; |
a78ac325 PZ |
6246 | } throttle_event = { |
6247 | .header = { | |
cdd6c482 | 6248 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6249 | .misc = 0, |
6250 | .size = sizeof(throttle_event), | |
6251 | }, | |
34f43927 | 6252 | .time = perf_event_clock(event), |
cdd6c482 IM |
6253 | .id = primary_event_id(event), |
6254 | .stream_id = event->id, | |
a78ac325 PZ |
6255 | }; |
6256 | ||
966ee4d6 | 6257 | if (enable) |
cdd6c482 | 6258 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6259 | |
c980d109 ACM |
6260 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6261 | ||
6262 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6263 | throttle_event.header.size); |
a78ac325 PZ |
6264 | if (ret) |
6265 | return; | |
6266 | ||
6267 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6268 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6269 | perf_output_end(&handle); |
6270 | } | |
6271 | ||
ec0d7729 AS |
6272 | static void perf_log_itrace_start(struct perf_event *event) |
6273 | { | |
6274 | struct perf_output_handle handle; | |
6275 | struct perf_sample_data sample; | |
6276 | struct perf_aux_event { | |
6277 | struct perf_event_header header; | |
6278 | u32 pid; | |
6279 | u32 tid; | |
6280 | } rec; | |
6281 | int ret; | |
6282 | ||
6283 | if (event->parent) | |
6284 | event = event->parent; | |
6285 | ||
6286 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6287 | event->hw.itrace_started) | |
6288 | return; | |
6289 | ||
ec0d7729 AS |
6290 | rec.header.type = PERF_RECORD_ITRACE_START; |
6291 | rec.header.misc = 0; | |
6292 | rec.header.size = sizeof(rec); | |
6293 | rec.pid = perf_event_pid(event, current); | |
6294 | rec.tid = perf_event_tid(event, current); | |
6295 | ||
6296 | perf_event_header__init_id(&rec.header, &sample, event); | |
6297 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6298 | ||
6299 | if (ret) | |
6300 | return; | |
6301 | ||
6302 | perf_output_put(&handle, rec); | |
6303 | perf_event__output_id_sample(event, &handle, &sample); | |
6304 | ||
6305 | perf_output_end(&handle); | |
6306 | } | |
6307 | ||
f6c7d5fe | 6308 | /* |
cdd6c482 | 6309 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6310 | */ |
6311 | ||
a8b0ca17 | 6312 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6313 | int throttle, struct perf_sample_data *data, |
6314 | struct pt_regs *regs) | |
f6c7d5fe | 6315 | { |
cdd6c482 IM |
6316 | int events = atomic_read(&event->event_limit); |
6317 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6318 | u64 seq; |
79f14641 PZ |
6319 | int ret = 0; |
6320 | ||
96398826 PZ |
6321 | /* |
6322 | * Non-sampling counters might still use the PMI to fold short | |
6323 | * hardware counters, ignore those. | |
6324 | */ | |
6325 | if (unlikely(!is_sampling_event(event))) | |
6326 | return 0; | |
6327 | ||
e050e3f0 SE |
6328 | seq = __this_cpu_read(perf_throttled_seq); |
6329 | if (seq != hwc->interrupts_seq) { | |
6330 | hwc->interrupts_seq = seq; | |
6331 | hwc->interrupts = 1; | |
6332 | } else { | |
6333 | hwc->interrupts++; | |
6334 | if (unlikely(throttle | |
6335 | && hwc->interrupts >= max_samples_per_tick)) { | |
6336 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6337 | hwc->interrupts = MAX_INTERRUPTS; |
6338 | perf_log_throttle(event, 0); | |
d84153d6 | 6339 | tick_nohz_full_kick(); |
a78ac325 PZ |
6340 | ret = 1; |
6341 | } | |
e050e3f0 | 6342 | } |
60db5e09 | 6343 | |
cdd6c482 | 6344 | if (event->attr.freq) { |
def0a9b2 | 6345 | u64 now = perf_clock(); |
abd50713 | 6346 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6347 | |
abd50713 | 6348 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6349 | |
abd50713 | 6350 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6351 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6352 | } |
6353 | ||
2023b359 PZ |
6354 | /* |
6355 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6356 | * events |
2023b359 PZ |
6357 | */ |
6358 | ||
cdd6c482 IM |
6359 | event->pending_kill = POLL_IN; |
6360 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6361 | ret = 1; |
cdd6c482 | 6362 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6363 | event->pending_disable = 1; |
6364 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6365 | } |
6366 | ||
453f19ee | 6367 | if (event->overflow_handler) |
a8b0ca17 | 6368 | event->overflow_handler(event, data, regs); |
453f19ee | 6369 | else |
a8b0ca17 | 6370 | perf_event_output(event, data, regs); |
453f19ee | 6371 | |
fed66e2c | 6372 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6373 | event->pending_wakeup = 1; |
6374 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6375 | } |
6376 | ||
79f14641 | 6377 | return ret; |
f6c7d5fe PZ |
6378 | } |
6379 | ||
a8b0ca17 | 6380 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6381 | struct perf_sample_data *data, |
6382 | struct pt_regs *regs) | |
850bc73f | 6383 | { |
a8b0ca17 | 6384 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6385 | } |
6386 | ||
15dbf27c | 6387 | /* |
cdd6c482 | 6388 | * Generic software event infrastructure |
15dbf27c PZ |
6389 | */ |
6390 | ||
b28ab83c PZ |
6391 | struct swevent_htable { |
6392 | struct swevent_hlist *swevent_hlist; | |
6393 | struct mutex hlist_mutex; | |
6394 | int hlist_refcount; | |
6395 | ||
6396 | /* Recursion avoidance in each contexts */ | |
6397 | int recursion[PERF_NR_CONTEXTS]; | |
6398 | }; | |
6399 | ||
6400 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6401 | ||
7b4b6658 | 6402 | /* |
cdd6c482 IM |
6403 | * We directly increment event->count and keep a second value in |
6404 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6405 | * is kept in the range [-sample_period, 0] so that we can use the |
6406 | * sign as trigger. | |
6407 | */ | |
6408 | ||
ab573844 | 6409 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6410 | { |
cdd6c482 | 6411 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6412 | u64 period = hwc->last_period; |
6413 | u64 nr, offset; | |
6414 | s64 old, val; | |
6415 | ||
6416 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6417 | |
6418 | again: | |
e7850595 | 6419 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6420 | if (val < 0) |
6421 | return 0; | |
15dbf27c | 6422 | |
7b4b6658 PZ |
6423 | nr = div64_u64(period + val, period); |
6424 | offset = nr * period; | |
6425 | val -= offset; | |
e7850595 | 6426 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6427 | goto again; |
15dbf27c | 6428 | |
7b4b6658 | 6429 | return nr; |
15dbf27c PZ |
6430 | } |
6431 | ||
0cff784a | 6432 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6433 | struct perf_sample_data *data, |
5622f295 | 6434 | struct pt_regs *regs) |
15dbf27c | 6435 | { |
cdd6c482 | 6436 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6437 | int throttle = 0; |
15dbf27c | 6438 | |
0cff784a PZ |
6439 | if (!overflow) |
6440 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6441 | |
7b4b6658 PZ |
6442 | if (hwc->interrupts == MAX_INTERRUPTS) |
6443 | return; | |
15dbf27c | 6444 | |
7b4b6658 | 6445 | for (; overflow; overflow--) { |
a8b0ca17 | 6446 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6447 | data, regs)) { |
7b4b6658 PZ |
6448 | /* |
6449 | * We inhibit the overflow from happening when | |
6450 | * hwc->interrupts == MAX_INTERRUPTS. | |
6451 | */ | |
6452 | break; | |
6453 | } | |
cf450a73 | 6454 | throttle = 1; |
7b4b6658 | 6455 | } |
15dbf27c PZ |
6456 | } |
6457 | ||
a4eaf7f1 | 6458 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6459 | struct perf_sample_data *data, |
5622f295 | 6460 | struct pt_regs *regs) |
7b4b6658 | 6461 | { |
cdd6c482 | 6462 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6463 | |
e7850595 | 6464 | local64_add(nr, &event->count); |
d6d020e9 | 6465 | |
0cff784a PZ |
6466 | if (!regs) |
6467 | return; | |
6468 | ||
6c7e550f | 6469 | if (!is_sampling_event(event)) |
7b4b6658 | 6470 | return; |
d6d020e9 | 6471 | |
5d81e5cf AV |
6472 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6473 | data->period = nr; | |
6474 | return perf_swevent_overflow(event, 1, data, regs); | |
6475 | } else | |
6476 | data->period = event->hw.last_period; | |
6477 | ||
0cff784a | 6478 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6479 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6480 | |
e7850595 | 6481 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6482 | return; |
df1a132b | 6483 | |
a8b0ca17 | 6484 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6485 | } |
6486 | ||
f5ffe02e FW |
6487 | static int perf_exclude_event(struct perf_event *event, |
6488 | struct pt_regs *regs) | |
6489 | { | |
a4eaf7f1 | 6490 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6491 | return 1; |
a4eaf7f1 | 6492 | |
f5ffe02e FW |
6493 | if (regs) { |
6494 | if (event->attr.exclude_user && user_mode(regs)) | |
6495 | return 1; | |
6496 | ||
6497 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6498 | return 1; | |
6499 | } | |
6500 | ||
6501 | return 0; | |
6502 | } | |
6503 | ||
cdd6c482 | 6504 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6505 | enum perf_type_id type, |
6fb2915d LZ |
6506 | u32 event_id, |
6507 | struct perf_sample_data *data, | |
6508 | struct pt_regs *regs) | |
15dbf27c | 6509 | { |
cdd6c482 | 6510 | if (event->attr.type != type) |
a21ca2ca | 6511 | return 0; |
f5ffe02e | 6512 | |
cdd6c482 | 6513 | if (event->attr.config != event_id) |
15dbf27c PZ |
6514 | return 0; |
6515 | ||
f5ffe02e FW |
6516 | if (perf_exclude_event(event, regs)) |
6517 | return 0; | |
15dbf27c PZ |
6518 | |
6519 | return 1; | |
6520 | } | |
6521 | ||
76e1d904 FW |
6522 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6523 | { | |
6524 | u64 val = event_id | (type << 32); | |
6525 | ||
6526 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6527 | } | |
6528 | ||
49f135ed FW |
6529 | static inline struct hlist_head * |
6530 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6531 | { |
49f135ed FW |
6532 | u64 hash = swevent_hash(type, event_id); |
6533 | ||
6534 | return &hlist->heads[hash]; | |
6535 | } | |
76e1d904 | 6536 | |
49f135ed FW |
6537 | /* For the read side: events when they trigger */ |
6538 | static inline struct hlist_head * | |
b28ab83c | 6539 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6540 | { |
6541 | struct swevent_hlist *hlist; | |
76e1d904 | 6542 | |
b28ab83c | 6543 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6544 | if (!hlist) |
6545 | return NULL; | |
6546 | ||
49f135ed FW |
6547 | return __find_swevent_head(hlist, type, event_id); |
6548 | } | |
6549 | ||
6550 | /* For the event head insertion and removal in the hlist */ | |
6551 | static inline struct hlist_head * | |
b28ab83c | 6552 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6553 | { |
6554 | struct swevent_hlist *hlist; | |
6555 | u32 event_id = event->attr.config; | |
6556 | u64 type = event->attr.type; | |
6557 | ||
6558 | /* | |
6559 | * Event scheduling is always serialized against hlist allocation | |
6560 | * and release. Which makes the protected version suitable here. | |
6561 | * The context lock guarantees that. | |
6562 | */ | |
b28ab83c | 6563 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6564 | lockdep_is_held(&event->ctx->lock)); |
6565 | if (!hlist) | |
6566 | return NULL; | |
6567 | ||
6568 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6569 | } |
6570 | ||
6571 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6572 | u64 nr, |
76e1d904 FW |
6573 | struct perf_sample_data *data, |
6574 | struct pt_regs *regs) | |
15dbf27c | 6575 | { |
4a32fea9 | 6576 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6577 | struct perf_event *event; |
76e1d904 | 6578 | struct hlist_head *head; |
15dbf27c | 6579 | |
76e1d904 | 6580 | rcu_read_lock(); |
b28ab83c | 6581 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6582 | if (!head) |
6583 | goto end; | |
6584 | ||
b67bfe0d | 6585 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6586 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6587 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6588 | } |
76e1d904 FW |
6589 | end: |
6590 | rcu_read_unlock(); | |
15dbf27c PZ |
6591 | } |
6592 | ||
86038c5e PZI |
6593 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6594 | ||
4ed7c92d | 6595 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6596 | { |
4a32fea9 | 6597 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6598 | |
b28ab83c | 6599 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6600 | } |
645e8cc0 | 6601 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6602 | |
fa9f90be | 6603 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6604 | { |
4a32fea9 | 6605 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6606 | |
b28ab83c | 6607 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6608 | } |
15dbf27c | 6609 | |
86038c5e | 6610 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6611 | { |
a4234bfc | 6612 | struct perf_sample_data data; |
4ed7c92d | 6613 | |
86038c5e | 6614 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6615 | return; |
a4234bfc | 6616 | |
fd0d000b | 6617 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6618 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6619 | } |
6620 | ||
6621 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6622 | { | |
6623 | int rctx; | |
6624 | ||
6625 | preempt_disable_notrace(); | |
6626 | rctx = perf_swevent_get_recursion_context(); | |
6627 | if (unlikely(rctx < 0)) | |
6628 | goto fail; | |
6629 | ||
6630 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6631 | |
6632 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6633 | fail: |
1c024eca | 6634 | preempt_enable_notrace(); |
b8e83514 PZ |
6635 | } |
6636 | ||
cdd6c482 | 6637 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6638 | { |
15dbf27c PZ |
6639 | } |
6640 | ||
a4eaf7f1 | 6641 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6642 | { |
4a32fea9 | 6643 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6644 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6645 | struct hlist_head *head; |
6646 | ||
6c7e550f | 6647 | if (is_sampling_event(event)) { |
7b4b6658 | 6648 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6649 | perf_swevent_set_period(event); |
7b4b6658 | 6650 | } |
76e1d904 | 6651 | |
a4eaf7f1 PZ |
6652 | hwc->state = !(flags & PERF_EF_START); |
6653 | ||
b28ab83c | 6654 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6655 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6656 | return -EINVAL; |
6657 | ||
6658 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6659 | perf_event_update_userpage(event); |
76e1d904 | 6660 | |
15dbf27c PZ |
6661 | return 0; |
6662 | } | |
6663 | ||
a4eaf7f1 | 6664 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6665 | { |
76e1d904 | 6666 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6667 | } |
6668 | ||
a4eaf7f1 | 6669 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6670 | { |
a4eaf7f1 | 6671 | event->hw.state = 0; |
d6d020e9 | 6672 | } |
aa9c4c0f | 6673 | |
a4eaf7f1 | 6674 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6675 | { |
a4eaf7f1 | 6676 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6677 | } |
6678 | ||
49f135ed FW |
6679 | /* Deref the hlist from the update side */ |
6680 | static inline struct swevent_hlist * | |
b28ab83c | 6681 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6682 | { |
b28ab83c PZ |
6683 | return rcu_dereference_protected(swhash->swevent_hlist, |
6684 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6685 | } |
6686 | ||
b28ab83c | 6687 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6688 | { |
b28ab83c | 6689 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6690 | |
49f135ed | 6691 | if (!hlist) |
76e1d904 FW |
6692 | return; |
6693 | ||
70691d4a | 6694 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6695 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6696 | } |
6697 | ||
6698 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6699 | { | |
b28ab83c | 6700 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6701 | |
b28ab83c | 6702 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6703 | |
b28ab83c PZ |
6704 | if (!--swhash->hlist_refcount) |
6705 | swevent_hlist_release(swhash); | |
76e1d904 | 6706 | |
b28ab83c | 6707 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6708 | } |
6709 | ||
6710 | static void swevent_hlist_put(struct perf_event *event) | |
6711 | { | |
6712 | int cpu; | |
6713 | ||
76e1d904 FW |
6714 | for_each_possible_cpu(cpu) |
6715 | swevent_hlist_put_cpu(event, cpu); | |
6716 | } | |
6717 | ||
6718 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6719 | { | |
b28ab83c | 6720 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6721 | int err = 0; |
6722 | ||
b28ab83c | 6723 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6724 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6725 | struct swevent_hlist *hlist; |
6726 | ||
6727 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6728 | if (!hlist) { | |
6729 | err = -ENOMEM; | |
6730 | goto exit; | |
6731 | } | |
b28ab83c | 6732 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6733 | } |
b28ab83c | 6734 | swhash->hlist_refcount++; |
9ed6060d | 6735 | exit: |
b28ab83c | 6736 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6737 | |
6738 | return err; | |
6739 | } | |
6740 | ||
6741 | static int swevent_hlist_get(struct perf_event *event) | |
6742 | { | |
6743 | int err; | |
6744 | int cpu, failed_cpu; | |
6745 | ||
76e1d904 FW |
6746 | get_online_cpus(); |
6747 | for_each_possible_cpu(cpu) { | |
6748 | err = swevent_hlist_get_cpu(event, cpu); | |
6749 | if (err) { | |
6750 | failed_cpu = cpu; | |
6751 | goto fail; | |
6752 | } | |
6753 | } | |
6754 | put_online_cpus(); | |
6755 | ||
6756 | return 0; | |
9ed6060d | 6757 | fail: |
76e1d904 FW |
6758 | for_each_possible_cpu(cpu) { |
6759 | if (cpu == failed_cpu) | |
6760 | break; | |
6761 | swevent_hlist_put_cpu(event, cpu); | |
6762 | } | |
6763 | ||
6764 | put_online_cpus(); | |
6765 | return err; | |
6766 | } | |
6767 | ||
c5905afb | 6768 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6769 | |
b0a873eb PZ |
6770 | static void sw_perf_event_destroy(struct perf_event *event) |
6771 | { | |
6772 | u64 event_id = event->attr.config; | |
95476b64 | 6773 | |
b0a873eb PZ |
6774 | WARN_ON(event->parent); |
6775 | ||
c5905afb | 6776 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6777 | swevent_hlist_put(event); |
6778 | } | |
6779 | ||
6780 | static int perf_swevent_init(struct perf_event *event) | |
6781 | { | |
8176cced | 6782 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6783 | |
6784 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6785 | return -ENOENT; | |
6786 | ||
2481c5fa SE |
6787 | /* |
6788 | * no branch sampling for software events | |
6789 | */ | |
6790 | if (has_branch_stack(event)) | |
6791 | return -EOPNOTSUPP; | |
6792 | ||
b0a873eb PZ |
6793 | switch (event_id) { |
6794 | case PERF_COUNT_SW_CPU_CLOCK: | |
6795 | case PERF_COUNT_SW_TASK_CLOCK: | |
6796 | return -ENOENT; | |
6797 | ||
6798 | default: | |
6799 | break; | |
6800 | } | |
6801 | ||
ce677831 | 6802 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6803 | return -ENOENT; |
6804 | ||
6805 | if (!event->parent) { | |
6806 | int err; | |
6807 | ||
6808 | err = swevent_hlist_get(event); | |
6809 | if (err) | |
6810 | return err; | |
6811 | ||
c5905afb | 6812 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6813 | event->destroy = sw_perf_event_destroy; |
6814 | } | |
6815 | ||
6816 | return 0; | |
6817 | } | |
6818 | ||
6819 | static struct pmu perf_swevent = { | |
89a1e187 | 6820 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6821 | |
34f43927 PZ |
6822 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6823 | ||
b0a873eb | 6824 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6825 | .add = perf_swevent_add, |
6826 | .del = perf_swevent_del, | |
6827 | .start = perf_swevent_start, | |
6828 | .stop = perf_swevent_stop, | |
1c024eca | 6829 | .read = perf_swevent_read, |
1c024eca PZ |
6830 | }; |
6831 | ||
b0a873eb PZ |
6832 | #ifdef CONFIG_EVENT_TRACING |
6833 | ||
1c024eca PZ |
6834 | static int perf_tp_filter_match(struct perf_event *event, |
6835 | struct perf_sample_data *data) | |
6836 | { | |
6837 | void *record = data->raw->data; | |
6838 | ||
b71b437e PZ |
6839 | /* only top level events have filters set */ |
6840 | if (event->parent) | |
6841 | event = event->parent; | |
6842 | ||
1c024eca PZ |
6843 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6844 | return 1; | |
6845 | return 0; | |
6846 | } | |
6847 | ||
6848 | static int perf_tp_event_match(struct perf_event *event, | |
6849 | struct perf_sample_data *data, | |
6850 | struct pt_regs *regs) | |
6851 | { | |
a0f7d0f7 FW |
6852 | if (event->hw.state & PERF_HES_STOPPED) |
6853 | return 0; | |
580d607c PZ |
6854 | /* |
6855 | * All tracepoints are from kernel-space. | |
6856 | */ | |
6857 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6858 | return 0; |
6859 | ||
6860 | if (!perf_tp_filter_match(event, data)) | |
6861 | return 0; | |
6862 | ||
6863 | return 1; | |
6864 | } | |
6865 | ||
6866 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6867 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6868 | struct task_struct *task) | |
95476b64 FW |
6869 | { |
6870 | struct perf_sample_data data; | |
1c024eca | 6871 | struct perf_event *event; |
1c024eca | 6872 | |
95476b64 FW |
6873 | struct perf_raw_record raw = { |
6874 | .size = entry_size, | |
6875 | .data = record, | |
6876 | }; | |
6877 | ||
fd0d000b | 6878 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6879 | data.raw = &raw; |
6880 | ||
b67bfe0d | 6881 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6882 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6883 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6884 | } |
ecc55f84 | 6885 | |
e6dab5ff AV |
6886 | /* |
6887 | * If we got specified a target task, also iterate its context and | |
6888 | * deliver this event there too. | |
6889 | */ | |
6890 | if (task && task != current) { | |
6891 | struct perf_event_context *ctx; | |
6892 | struct trace_entry *entry = record; | |
6893 | ||
6894 | rcu_read_lock(); | |
6895 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6896 | if (!ctx) | |
6897 | goto unlock; | |
6898 | ||
6899 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6900 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6901 | continue; | |
6902 | if (event->attr.config != entry->type) | |
6903 | continue; | |
6904 | if (perf_tp_event_match(event, &data, regs)) | |
6905 | perf_swevent_event(event, count, &data, regs); | |
6906 | } | |
6907 | unlock: | |
6908 | rcu_read_unlock(); | |
6909 | } | |
6910 | ||
ecc55f84 | 6911 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6912 | } |
6913 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6914 | ||
cdd6c482 | 6915 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6916 | { |
1c024eca | 6917 | perf_trace_destroy(event); |
e077df4f PZ |
6918 | } |
6919 | ||
b0a873eb | 6920 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6921 | { |
76e1d904 FW |
6922 | int err; |
6923 | ||
b0a873eb PZ |
6924 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6925 | return -ENOENT; | |
6926 | ||
2481c5fa SE |
6927 | /* |
6928 | * no branch sampling for tracepoint events | |
6929 | */ | |
6930 | if (has_branch_stack(event)) | |
6931 | return -EOPNOTSUPP; | |
6932 | ||
1c024eca PZ |
6933 | err = perf_trace_init(event); |
6934 | if (err) | |
b0a873eb | 6935 | return err; |
e077df4f | 6936 | |
cdd6c482 | 6937 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6938 | |
b0a873eb PZ |
6939 | return 0; |
6940 | } | |
6941 | ||
6942 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6943 | .task_ctx_nr = perf_sw_context, |
6944 | ||
b0a873eb | 6945 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6946 | .add = perf_trace_add, |
6947 | .del = perf_trace_del, | |
6948 | .start = perf_swevent_start, | |
6949 | .stop = perf_swevent_stop, | |
b0a873eb | 6950 | .read = perf_swevent_read, |
b0a873eb PZ |
6951 | }; |
6952 | ||
6953 | static inline void perf_tp_register(void) | |
6954 | { | |
2e80a82a | 6955 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6956 | } |
6fb2915d LZ |
6957 | |
6958 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6959 | { | |
6960 | char *filter_str; | |
6961 | int ret; | |
6962 | ||
6963 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6964 | return -EINVAL; | |
6965 | ||
6966 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6967 | if (IS_ERR(filter_str)) | |
6968 | return PTR_ERR(filter_str); | |
6969 | ||
6970 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6971 | ||
6972 | kfree(filter_str); | |
6973 | return ret; | |
6974 | } | |
6975 | ||
6976 | static void perf_event_free_filter(struct perf_event *event) | |
6977 | { | |
6978 | ftrace_profile_free_filter(event); | |
6979 | } | |
6980 | ||
2541517c AS |
6981 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
6982 | { | |
6983 | struct bpf_prog *prog; | |
6984 | ||
6985 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6986 | return -EINVAL; | |
6987 | ||
6988 | if (event->tp_event->prog) | |
6989 | return -EEXIST; | |
6990 | ||
04a22fae WN |
6991 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
6992 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
6993 | return -EINVAL; |
6994 | ||
6995 | prog = bpf_prog_get(prog_fd); | |
6996 | if (IS_ERR(prog)) | |
6997 | return PTR_ERR(prog); | |
6998 | ||
6c373ca8 | 6999 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7000 | /* valid fd, but invalid bpf program type */ |
7001 | bpf_prog_put(prog); | |
7002 | return -EINVAL; | |
7003 | } | |
7004 | ||
7005 | event->tp_event->prog = prog; | |
7006 | ||
7007 | return 0; | |
7008 | } | |
7009 | ||
7010 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7011 | { | |
7012 | struct bpf_prog *prog; | |
7013 | ||
7014 | if (!event->tp_event) | |
7015 | return; | |
7016 | ||
7017 | prog = event->tp_event->prog; | |
7018 | if (prog) { | |
7019 | event->tp_event->prog = NULL; | |
7020 | bpf_prog_put(prog); | |
7021 | } | |
7022 | } | |
7023 | ||
e077df4f | 7024 | #else |
6fb2915d | 7025 | |
b0a873eb | 7026 | static inline void perf_tp_register(void) |
e077df4f | 7027 | { |
e077df4f | 7028 | } |
6fb2915d LZ |
7029 | |
7030 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7031 | { | |
7032 | return -ENOENT; | |
7033 | } | |
7034 | ||
7035 | static void perf_event_free_filter(struct perf_event *event) | |
7036 | { | |
7037 | } | |
7038 | ||
2541517c AS |
7039 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7040 | { | |
7041 | return -ENOENT; | |
7042 | } | |
7043 | ||
7044 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7045 | { | |
7046 | } | |
07b139c8 | 7047 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7048 | |
24f1e32c | 7049 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7050 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7051 | { |
f5ffe02e FW |
7052 | struct perf_sample_data sample; |
7053 | struct pt_regs *regs = data; | |
7054 | ||
fd0d000b | 7055 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7056 | |
a4eaf7f1 | 7057 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7058 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7059 | } |
7060 | #endif | |
7061 | ||
b0a873eb PZ |
7062 | /* |
7063 | * hrtimer based swevent callback | |
7064 | */ | |
f29ac756 | 7065 | |
b0a873eb | 7066 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7067 | { |
b0a873eb PZ |
7068 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7069 | struct perf_sample_data data; | |
7070 | struct pt_regs *regs; | |
7071 | struct perf_event *event; | |
7072 | u64 period; | |
f29ac756 | 7073 | |
b0a873eb | 7074 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7075 | |
7076 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7077 | return HRTIMER_NORESTART; | |
7078 | ||
b0a873eb | 7079 | event->pmu->read(event); |
f344011c | 7080 | |
fd0d000b | 7081 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7082 | regs = get_irq_regs(); |
7083 | ||
7084 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7085 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7086 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7087 | ret = HRTIMER_NORESTART; |
7088 | } | |
24f1e32c | 7089 | |
b0a873eb PZ |
7090 | period = max_t(u64, 10000, event->hw.sample_period); |
7091 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7092 | |
b0a873eb | 7093 | return ret; |
f29ac756 PZ |
7094 | } |
7095 | ||
b0a873eb | 7096 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7097 | { |
b0a873eb | 7098 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7099 | s64 period; |
7100 | ||
7101 | if (!is_sampling_event(event)) | |
7102 | return; | |
f5ffe02e | 7103 | |
5d508e82 FBH |
7104 | period = local64_read(&hwc->period_left); |
7105 | if (period) { | |
7106 | if (period < 0) | |
7107 | period = 10000; | |
fa407f35 | 7108 | |
5d508e82 FBH |
7109 | local64_set(&hwc->period_left, 0); |
7110 | } else { | |
7111 | period = max_t(u64, 10000, hwc->sample_period); | |
7112 | } | |
3497d206 TG |
7113 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7114 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7115 | } |
b0a873eb PZ |
7116 | |
7117 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7118 | { |
b0a873eb PZ |
7119 | struct hw_perf_event *hwc = &event->hw; |
7120 | ||
6c7e550f | 7121 | if (is_sampling_event(event)) { |
b0a873eb | 7122 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7123 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7124 | |
7125 | hrtimer_cancel(&hwc->hrtimer); | |
7126 | } | |
24f1e32c FW |
7127 | } |
7128 | ||
ba3dd36c PZ |
7129 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7130 | { | |
7131 | struct hw_perf_event *hwc = &event->hw; | |
7132 | ||
7133 | if (!is_sampling_event(event)) | |
7134 | return; | |
7135 | ||
7136 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7137 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7138 | ||
7139 | /* | |
7140 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7141 | * mapping and avoid the whole period adjust feedback stuff. | |
7142 | */ | |
7143 | if (event->attr.freq) { | |
7144 | long freq = event->attr.sample_freq; | |
7145 | ||
7146 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7147 | hwc->sample_period = event->attr.sample_period; | |
7148 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7149 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7150 | event->attr.freq = 0; |
7151 | } | |
7152 | } | |
7153 | ||
b0a873eb PZ |
7154 | /* |
7155 | * Software event: cpu wall time clock | |
7156 | */ | |
7157 | ||
7158 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7159 | { |
b0a873eb PZ |
7160 | s64 prev; |
7161 | u64 now; | |
7162 | ||
a4eaf7f1 | 7163 | now = local_clock(); |
b0a873eb PZ |
7164 | prev = local64_xchg(&event->hw.prev_count, now); |
7165 | local64_add(now - prev, &event->count); | |
24f1e32c | 7166 | } |
24f1e32c | 7167 | |
a4eaf7f1 | 7168 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7169 | { |
a4eaf7f1 | 7170 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7171 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7172 | } |
7173 | ||
a4eaf7f1 | 7174 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7175 | { |
b0a873eb PZ |
7176 | perf_swevent_cancel_hrtimer(event); |
7177 | cpu_clock_event_update(event); | |
7178 | } | |
f29ac756 | 7179 | |
a4eaf7f1 PZ |
7180 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7181 | { | |
7182 | if (flags & PERF_EF_START) | |
7183 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7184 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7185 | |
7186 | return 0; | |
7187 | } | |
7188 | ||
7189 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7190 | { | |
7191 | cpu_clock_event_stop(event, flags); | |
7192 | } | |
7193 | ||
b0a873eb PZ |
7194 | static void cpu_clock_event_read(struct perf_event *event) |
7195 | { | |
7196 | cpu_clock_event_update(event); | |
7197 | } | |
f344011c | 7198 | |
b0a873eb PZ |
7199 | static int cpu_clock_event_init(struct perf_event *event) |
7200 | { | |
7201 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7202 | return -ENOENT; | |
7203 | ||
7204 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7205 | return -ENOENT; | |
7206 | ||
2481c5fa SE |
7207 | /* |
7208 | * no branch sampling for software events | |
7209 | */ | |
7210 | if (has_branch_stack(event)) | |
7211 | return -EOPNOTSUPP; | |
7212 | ||
ba3dd36c PZ |
7213 | perf_swevent_init_hrtimer(event); |
7214 | ||
b0a873eb | 7215 | return 0; |
f29ac756 PZ |
7216 | } |
7217 | ||
b0a873eb | 7218 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7219 | .task_ctx_nr = perf_sw_context, |
7220 | ||
34f43927 PZ |
7221 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7222 | ||
b0a873eb | 7223 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7224 | .add = cpu_clock_event_add, |
7225 | .del = cpu_clock_event_del, | |
7226 | .start = cpu_clock_event_start, | |
7227 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7228 | .read = cpu_clock_event_read, |
7229 | }; | |
7230 | ||
7231 | /* | |
7232 | * Software event: task time clock | |
7233 | */ | |
7234 | ||
7235 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7236 | { |
b0a873eb PZ |
7237 | u64 prev; |
7238 | s64 delta; | |
5c92d124 | 7239 | |
b0a873eb PZ |
7240 | prev = local64_xchg(&event->hw.prev_count, now); |
7241 | delta = now - prev; | |
7242 | local64_add(delta, &event->count); | |
7243 | } | |
5c92d124 | 7244 | |
a4eaf7f1 | 7245 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7246 | { |
a4eaf7f1 | 7247 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7248 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7249 | } |
7250 | ||
a4eaf7f1 | 7251 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7252 | { |
7253 | perf_swevent_cancel_hrtimer(event); | |
7254 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7255 | } |
7256 | ||
7257 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7258 | { | |
7259 | if (flags & PERF_EF_START) | |
7260 | task_clock_event_start(event, flags); | |
6a694a60 | 7261 | perf_event_update_userpage(event); |
b0a873eb | 7262 | |
a4eaf7f1 PZ |
7263 | return 0; |
7264 | } | |
7265 | ||
7266 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7267 | { | |
7268 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7269 | } |
7270 | ||
7271 | static void task_clock_event_read(struct perf_event *event) | |
7272 | { | |
768a06e2 PZ |
7273 | u64 now = perf_clock(); |
7274 | u64 delta = now - event->ctx->timestamp; | |
7275 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7276 | |
7277 | task_clock_event_update(event, time); | |
7278 | } | |
7279 | ||
7280 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7281 | { |
b0a873eb PZ |
7282 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7283 | return -ENOENT; | |
7284 | ||
7285 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7286 | return -ENOENT; | |
7287 | ||
2481c5fa SE |
7288 | /* |
7289 | * no branch sampling for software events | |
7290 | */ | |
7291 | if (has_branch_stack(event)) | |
7292 | return -EOPNOTSUPP; | |
7293 | ||
ba3dd36c PZ |
7294 | perf_swevent_init_hrtimer(event); |
7295 | ||
b0a873eb | 7296 | return 0; |
6fb2915d LZ |
7297 | } |
7298 | ||
b0a873eb | 7299 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7300 | .task_ctx_nr = perf_sw_context, |
7301 | ||
34f43927 PZ |
7302 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7303 | ||
b0a873eb | 7304 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7305 | .add = task_clock_event_add, |
7306 | .del = task_clock_event_del, | |
7307 | .start = task_clock_event_start, | |
7308 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7309 | .read = task_clock_event_read, |
7310 | }; | |
6fb2915d | 7311 | |
ad5133b7 | 7312 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7313 | { |
e077df4f | 7314 | } |
6fb2915d | 7315 | |
fbbe0701 SB |
7316 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7317 | { | |
7318 | } | |
7319 | ||
ad5133b7 | 7320 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7321 | { |
ad5133b7 | 7322 | return 0; |
6fb2915d LZ |
7323 | } |
7324 | ||
18ab2cd3 | 7325 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7326 | |
7327 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7328 | { |
fbbe0701 SB |
7329 | __this_cpu_write(nop_txn_flags, flags); |
7330 | ||
7331 | if (flags & ~PERF_PMU_TXN_ADD) | |
7332 | return; | |
7333 | ||
ad5133b7 | 7334 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7335 | } |
7336 | ||
ad5133b7 PZ |
7337 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7338 | { | |
fbbe0701 SB |
7339 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7340 | ||
7341 | __this_cpu_write(nop_txn_flags, 0); | |
7342 | ||
7343 | if (flags & ~PERF_PMU_TXN_ADD) | |
7344 | return 0; | |
7345 | ||
ad5133b7 PZ |
7346 | perf_pmu_enable(pmu); |
7347 | return 0; | |
7348 | } | |
e077df4f | 7349 | |
ad5133b7 | 7350 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7351 | { |
fbbe0701 SB |
7352 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7353 | ||
7354 | __this_cpu_write(nop_txn_flags, 0); | |
7355 | ||
7356 | if (flags & ~PERF_PMU_TXN_ADD) | |
7357 | return; | |
7358 | ||
ad5133b7 | 7359 | perf_pmu_enable(pmu); |
24f1e32c FW |
7360 | } |
7361 | ||
35edc2a5 PZ |
7362 | static int perf_event_idx_default(struct perf_event *event) |
7363 | { | |
c719f560 | 7364 | return 0; |
35edc2a5 PZ |
7365 | } |
7366 | ||
8dc85d54 PZ |
7367 | /* |
7368 | * Ensures all contexts with the same task_ctx_nr have the same | |
7369 | * pmu_cpu_context too. | |
7370 | */ | |
9e317041 | 7371 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7372 | { |
8dc85d54 | 7373 | struct pmu *pmu; |
b326e956 | 7374 | |
8dc85d54 PZ |
7375 | if (ctxn < 0) |
7376 | return NULL; | |
24f1e32c | 7377 | |
8dc85d54 PZ |
7378 | list_for_each_entry(pmu, &pmus, entry) { |
7379 | if (pmu->task_ctx_nr == ctxn) | |
7380 | return pmu->pmu_cpu_context; | |
7381 | } | |
24f1e32c | 7382 | |
8dc85d54 | 7383 | return NULL; |
24f1e32c FW |
7384 | } |
7385 | ||
51676957 | 7386 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7387 | { |
51676957 PZ |
7388 | int cpu; |
7389 | ||
7390 | for_each_possible_cpu(cpu) { | |
7391 | struct perf_cpu_context *cpuctx; | |
7392 | ||
7393 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7394 | ||
3f1f3320 PZ |
7395 | if (cpuctx->unique_pmu == old_pmu) |
7396 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7397 | } |
7398 | } | |
7399 | ||
7400 | static void free_pmu_context(struct pmu *pmu) | |
7401 | { | |
7402 | struct pmu *i; | |
f5ffe02e | 7403 | |
8dc85d54 | 7404 | mutex_lock(&pmus_lock); |
0475f9ea | 7405 | /* |
8dc85d54 | 7406 | * Like a real lame refcount. |
0475f9ea | 7407 | */ |
51676957 PZ |
7408 | list_for_each_entry(i, &pmus, entry) { |
7409 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7410 | update_pmu_context(i, pmu); | |
8dc85d54 | 7411 | goto out; |
51676957 | 7412 | } |
8dc85d54 | 7413 | } |
d6d020e9 | 7414 | |
51676957 | 7415 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7416 | out: |
7417 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7418 | } |
2e80a82a | 7419 | static struct idr pmu_idr; |
d6d020e9 | 7420 | |
abe43400 PZ |
7421 | static ssize_t |
7422 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7423 | { | |
7424 | struct pmu *pmu = dev_get_drvdata(dev); | |
7425 | ||
7426 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7427 | } | |
90826ca7 | 7428 | static DEVICE_ATTR_RO(type); |
abe43400 | 7429 | |
62b85639 SE |
7430 | static ssize_t |
7431 | perf_event_mux_interval_ms_show(struct device *dev, | |
7432 | struct device_attribute *attr, | |
7433 | char *page) | |
7434 | { | |
7435 | struct pmu *pmu = dev_get_drvdata(dev); | |
7436 | ||
7437 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7438 | } | |
7439 | ||
272325c4 PZ |
7440 | static DEFINE_MUTEX(mux_interval_mutex); |
7441 | ||
62b85639 SE |
7442 | static ssize_t |
7443 | perf_event_mux_interval_ms_store(struct device *dev, | |
7444 | struct device_attribute *attr, | |
7445 | const char *buf, size_t count) | |
7446 | { | |
7447 | struct pmu *pmu = dev_get_drvdata(dev); | |
7448 | int timer, cpu, ret; | |
7449 | ||
7450 | ret = kstrtoint(buf, 0, &timer); | |
7451 | if (ret) | |
7452 | return ret; | |
7453 | ||
7454 | if (timer < 1) | |
7455 | return -EINVAL; | |
7456 | ||
7457 | /* same value, noting to do */ | |
7458 | if (timer == pmu->hrtimer_interval_ms) | |
7459 | return count; | |
7460 | ||
272325c4 | 7461 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7462 | pmu->hrtimer_interval_ms = timer; |
7463 | ||
7464 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7465 | get_online_cpus(); |
7466 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7467 | struct perf_cpu_context *cpuctx; |
7468 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7469 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7470 | ||
272325c4 PZ |
7471 | cpu_function_call(cpu, |
7472 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7473 | } |
272325c4 PZ |
7474 | put_online_cpus(); |
7475 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7476 | |
7477 | return count; | |
7478 | } | |
90826ca7 | 7479 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7480 | |
90826ca7 GKH |
7481 | static struct attribute *pmu_dev_attrs[] = { |
7482 | &dev_attr_type.attr, | |
7483 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7484 | NULL, | |
abe43400 | 7485 | }; |
90826ca7 | 7486 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7487 | |
7488 | static int pmu_bus_running; | |
7489 | static struct bus_type pmu_bus = { | |
7490 | .name = "event_source", | |
90826ca7 | 7491 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7492 | }; |
7493 | ||
7494 | static void pmu_dev_release(struct device *dev) | |
7495 | { | |
7496 | kfree(dev); | |
7497 | } | |
7498 | ||
7499 | static int pmu_dev_alloc(struct pmu *pmu) | |
7500 | { | |
7501 | int ret = -ENOMEM; | |
7502 | ||
7503 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7504 | if (!pmu->dev) | |
7505 | goto out; | |
7506 | ||
0c9d42ed | 7507 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7508 | device_initialize(pmu->dev); |
7509 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7510 | if (ret) | |
7511 | goto free_dev; | |
7512 | ||
7513 | dev_set_drvdata(pmu->dev, pmu); | |
7514 | pmu->dev->bus = &pmu_bus; | |
7515 | pmu->dev->release = pmu_dev_release; | |
7516 | ret = device_add(pmu->dev); | |
7517 | if (ret) | |
7518 | goto free_dev; | |
7519 | ||
7520 | out: | |
7521 | return ret; | |
7522 | ||
7523 | free_dev: | |
7524 | put_device(pmu->dev); | |
7525 | goto out; | |
7526 | } | |
7527 | ||
547e9fd7 | 7528 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7529 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7530 | |
03d8e80b | 7531 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7532 | { |
108b02cf | 7533 | int cpu, ret; |
24f1e32c | 7534 | |
b0a873eb | 7535 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7536 | ret = -ENOMEM; |
7537 | pmu->pmu_disable_count = alloc_percpu(int); | |
7538 | if (!pmu->pmu_disable_count) | |
7539 | goto unlock; | |
f29ac756 | 7540 | |
2e80a82a PZ |
7541 | pmu->type = -1; |
7542 | if (!name) | |
7543 | goto skip_type; | |
7544 | pmu->name = name; | |
7545 | ||
7546 | if (type < 0) { | |
0e9c3be2 TH |
7547 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7548 | if (type < 0) { | |
7549 | ret = type; | |
2e80a82a PZ |
7550 | goto free_pdc; |
7551 | } | |
7552 | } | |
7553 | pmu->type = type; | |
7554 | ||
abe43400 PZ |
7555 | if (pmu_bus_running) { |
7556 | ret = pmu_dev_alloc(pmu); | |
7557 | if (ret) | |
7558 | goto free_idr; | |
7559 | } | |
7560 | ||
2e80a82a | 7561 | skip_type: |
8dc85d54 PZ |
7562 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7563 | if (pmu->pmu_cpu_context) | |
7564 | goto got_cpu_context; | |
f29ac756 | 7565 | |
c4814202 | 7566 | ret = -ENOMEM; |
108b02cf PZ |
7567 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7568 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7569 | goto free_dev; |
f344011c | 7570 | |
108b02cf PZ |
7571 | for_each_possible_cpu(cpu) { |
7572 | struct perf_cpu_context *cpuctx; | |
7573 | ||
7574 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7575 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7576 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7577 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7578 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7579 | |
272325c4 | 7580 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7581 | |
3f1f3320 | 7582 | cpuctx->unique_pmu = pmu; |
108b02cf | 7583 | } |
76e1d904 | 7584 | |
8dc85d54 | 7585 | got_cpu_context: |
ad5133b7 PZ |
7586 | if (!pmu->start_txn) { |
7587 | if (pmu->pmu_enable) { | |
7588 | /* | |
7589 | * If we have pmu_enable/pmu_disable calls, install | |
7590 | * transaction stubs that use that to try and batch | |
7591 | * hardware accesses. | |
7592 | */ | |
7593 | pmu->start_txn = perf_pmu_start_txn; | |
7594 | pmu->commit_txn = perf_pmu_commit_txn; | |
7595 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7596 | } else { | |
fbbe0701 | 7597 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7598 | pmu->commit_txn = perf_pmu_nop_int; |
7599 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7600 | } |
5c92d124 | 7601 | } |
15dbf27c | 7602 | |
ad5133b7 PZ |
7603 | if (!pmu->pmu_enable) { |
7604 | pmu->pmu_enable = perf_pmu_nop_void; | |
7605 | pmu->pmu_disable = perf_pmu_nop_void; | |
7606 | } | |
7607 | ||
35edc2a5 PZ |
7608 | if (!pmu->event_idx) |
7609 | pmu->event_idx = perf_event_idx_default; | |
7610 | ||
b0a873eb | 7611 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7612 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7613 | ret = 0; |
7614 | unlock: | |
b0a873eb PZ |
7615 | mutex_unlock(&pmus_lock); |
7616 | ||
33696fc0 | 7617 | return ret; |
108b02cf | 7618 | |
abe43400 PZ |
7619 | free_dev: |
7620 | device_del(pmu->dev); | |
7621 | put_device(pmu->dev); | |
7622 | ||
2e80a82a PZ |
7623 | free_idr: |
7624 | if (pmu->type >= PERF_TYPE_MAX) | |
7625 | idr_remove(&pmu_idr, pmu->type); | |
7626 | ||
108b02cf PZ |
7627 | free_pdc: |
7628 | free_percpu(pmu->pmu_disable_count); | |
7629 | goto unlock; | |
f29ac756 | 7630 | } |
c464c76e | 7631 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7632 | |
b0a873eb | 7633 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7634 | { |
b0a873eb PZ |
7635 | mutex_lock(&pmus_lock); |
7636 | list_del_rcu(&pmu->entry); | |
7637 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7638 | |
0475f9ea | 7639 | /* |
cde8e884 PZ |
7640 | * We dereference the pmu list under both SRCU and regular RCU, so |
7641 | * synchronize against both of those. | |
0475f9ea | 7642 | */ |
b0a873eb | 7643 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7644 | synchronize_rcu(); |
d6d020e9 | 7645 | |
33696fc0 | 7646 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7647 | if (pmu->type >= PERF_TYPE_MAX) |
7648 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7649 | device_del(pmu->dev); |
7650 | put_device(pmu->dev); | |
51676957 | 7651 | free_pmu_context(pmu); |
b0a873eb | 7652 | } |
c464c76e | 7653 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7654 | |
cc34b98b MR |
7655 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7656 | { | |
ccd41c86 | 7657 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7658 | int ret; |
7659 | ||
7660 | if (!try_module_get(pmu->module)) | |
7661 | return -ENODEV; | |
ccd41c86 PZ |
7662 | |
7663 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7664 | /* |
7665 | * This ctx->mutex can nest when we're called through | |
7666 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7667 | */ | |
7668 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7669 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7670 | BUG_ON(!ctx); |
7671 | } | |
7672 | ||
cc34b98b MR |
7673 | event->pmu = pmu; |
7674 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7675 | |
7676 | if (ctx) | |
7677 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7678 | ||
cc34b98b MR |
7679 | if (ret) |
7680 | module_put(pmu->module); | |
7681 | ||
7682 | return ret; | |
7683 | } | |
7684 | ||
18ab2cd3 | 7685 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7686 | { |
7687 | struct pmu *pmu = NULL; | |
7688 | int idx; | |
940c5b29 | 7689 | int ret; |
b0a873eb PZ |
7690 | |
7691 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7692 | |
7693 | rcu_read_lock(); | |
7694 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7695 | rcu_read_unlock(); | |
940c5b29 | 7696 | if (pmu) { |
cc34b98b | 7697 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7698 | if (ret) |
7699 | pmu = ERR_PTR(ret); | |
2e80a82a | 7700 | goto unlock; |
940c5b29 | 7701 | } |
2e80a82a | 7702 | |
b0a873eb | 7703 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7704 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7705 | if (!ret) |
e5f4d339 | 7706 | goto unlock; |
76e1d904 | 7707 | |
b0a873eb PZ |
7708 | if (ret != -ENOENT) { |
7709 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7710 | goto unlock; |
f344011c | 7711 | } |
5c92d124 | 7712 | } |
e5f4d339 PZ |
7713 | pmu = ERR_PTR(-ENOENT); |
7714 | unlock: | |
b0a873eb | 7715 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7716 | |
4aeb0b42 | 7717 | return pmu; |
5c92d124 IM |
7718 | } |
7719 | ||
4beb31f3 FW |
7720 | static void account_event_cpu(struct perf_event *event, int cpu) |
7721 | { | |
7722 | if (event->parent) | |
7723 | return; | |
7724 | ||
4beb31f3 FW |
7725 | if (is_cgroup_event(event)) |
7726 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7727 | } | |
7728 | ||
766d6c07 FW |
7729 | static void account_event(struct perf_event *event) |
7730 | { | |
25432ae9 PZ |
7731 | bool inc = false; |
7732 | ||
4beb31f3 FW |
7733 | if (event->parent) |
7734 | return; | |
7735 | ||
766d6c07 | 7736 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7737 | inc = true; |
766d6c07 FW |
7738 | if (event->attr.mmap || event->attr.mmap_data) |
7739 | atomic_inc(&nr_mmap_events); | |
7740 | if (event->attr.comm) | |
7741 | atomic_inc(&nr_comm_events); | |
7742 | if (event->attr.task) | |
7743 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7744 | if (event->attr.freq) { |
7745 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7746 | tick_nohz_full_kick_all(); | |
7747 | } | |
45ac1403 AH |
7748 | if (event->attr.context_switch) { |
7749 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7750 | inc = true; |
45ac1403 | 7751 | } |
4beb31f3 | 7752 | if (has_branch_stack(event)) |
25432ae9 | 7753 | inc = true; |
4beb31f3 | 7754 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7755 | inc = true; |
7756 | ||
7757 | if (inc) | |
766d6c07 | 7758 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7759 | |
7760 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7761 | } |
7762 | ||
0793a61d | 7763 | /* |
cdd6c482 | 7764 | * Allocate and initialize a event structure |
0793a61d | 7765 | */ |
cdd6c482 | 7766 | static struct perf_event * |
c3f00c70 | 7767 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7768 | struct task_struct *task, |
7769 | struct perf_event *group_leader, | |
7770 | struct perf_event *parent_event, | |
4dc0da86 | 7771 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7772 | void *context, int cgroup_fd) |
0793a61d | 7773 | { |
51b0fe39 | 7774 | struct pmu *pmu; |
cdd6c482 IM |
7775 | struct perf_event *event; |
7776 | struct hw_perf_event *hwc; | |
90983b16 | 7777 | long err = -EINVAL; |
0793a61d | 7778 | |
66832eb4 ON |
7779 | if ((unsigned)cpu >= nr_cpu_ids) { |
7780 | if (!task || cpu != -1) | |
7781 | return ERR_PTR(-EINVAL); | |
7782 | } | |
7783 | ||
c3f00c70 | 7784 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7785 | if (!event) |
d5d2bc0d | 7786 | return ERR_PTR(-ENOMEM); |
0793a61d | 7787 | |
04289bb9 | 7788 | /* |
cdd6c482 | 7789 | * Single events are their own group leaders, with an |
04289bb9 IM |
7790 | * empty sibling list: |
7791 | */ | |
7792 | if (!group_leader) | |
cdd6c482 | 7793 | group_leader = event; |
04289bb9 | 7794 | |
cdd6c482 IM |
7795 | mutex_init(&event->child_mutex); |
7796 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7797 | |
cdd6c482 IM |
7798 | INIT_LIST_HEAD(&event->group_entry); |
7799 | INIT_LIST_HEAD(&event->event_entry); | |
7800 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7801 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7802 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7803 | INIT_HLIST_NODE(&event->hlist_entry); |
7804 | ||
10c6db11 | 7805 | |
cdd6c482 | 7806 | init_waitqueue_head(&event->waitq); |
e360adbe | 7807 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7808 | |
cdd6c482 | 7809 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7810 | |
a6fa941d | 7811 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7812 | event->cpu = cpu; |
7813 | event->attr = *attr; | |
7814 | event->group_leader = group_leader; | |
7815 | event->pmu = NULL; | |
cdd6c482 | 7816 | event->oncpu = -1; |
a96bbc16 | 7817 | |
cdd6c482 | 7818 | event->parent = parent_event; |
b84fbc9f | 7819 | |
17cf22c3 | 7820 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7821 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7822 | |
cdd6c482 | 7823 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7824 | |
d580ff86 PZ |
7825 | if (task) { |
7826 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7827 | /* |
50f16a8b PZ |
7828 | * XXX pmu::event_init needs to know what task to account to |
7829 | * and we cannot use the ctx information because we need the | |
7830 | * pmu before we get a ctx. | |
d580ff86 | 7831 | */ |
50f16a8b | 7832 | event->hw.target = task; |
d580ff86 PZ |
7833 | } |
7834 | ||
34f43927 PZ |
7835 | event->clock = &local_clock; |
7836 | if (parent_event) | |
7837 | event->clock = parent_event->clock; | |
7838 | ||
4dc0da86 | 7839 | if (!overflow_handler && parent_event) { |
b326e956 | 7840 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7841 | context = parent_event->overflow_handler_context; |
7842 | } | |
66832eb4 | 7843 | |
b326e956 | 7844 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7845 | event->overflow_handler_context = context; |
97eaf530 | 7846 | |
0231bb53 | 7847 | perf_event__state_init(event); |
a86ed508 | 7848 | |
4aeb0b42 | 7849 | pmu = NULL; |
b8e83514 | 7850 | |
cdd6c482 | 7851 | hwc = &event->hw; |
bd2b5b12 | 7852 | hwc->sample_period = attr->sample_period; |
0d48696f | 7853 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7854 | hwc->sample_period = 1; |
eced1dfc | 7855 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7856 | |
e7850595 | 7857 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7858 | |
2023b359 | 7859 | /* |
cdd6c482 | 7860 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7861 | */ |
3dab77fb | 7862 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7863 | goto err_ns; |
a46a2300 YZ |
7864 | |
7865 | if (!has_branch_stack(event)) | |
7866 | event->attr.branch_sample_type = 0; | |
2023b359 | 7867 | |
79dff51e MF |
7868 | if (cgroup_fd != -1) { |
7869 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7870 | if (err) | |
7871 | goto err_ns; | |
7872 | } | |
7873 | ||
b0a873eb | 7874 | pmu = perf_init_event(event); |
4aeb0b42 | 7875 | if (!pmu) |
90983b16 FW |
7876 | goto err_ns; |
7877 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7878 | err = PTR_ERR(pmu); |
90983b16 | 7879 | goto err_ns; |
621a01ea | 7880 | } |
d5d2bc0d | 7881 | |
bed5b25a AS |
7882 | err = exclusive_event_init(event); |
7883 | if (err) | |
7884 | goto err_pmu; | |
7885 | ||
cdd6c482 | 7886 | if (!event->parent) { |
927c7a9e FW |
7887 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7888 | err = get_callchain_buffers(); | |
90983b16 | 7889 | if (err) |
bed5b25a | 7890 | goto err_per_task; |
d010b332 | 7891 | } |
f344011c | 7892 | } |
9ee318a7 | 7893 | |
cdd6c482 | 7894 | return event; |
90983b16 | 7895 | |
bed5b25a AS |
7896 | err_per_task: |
7897 | exclusive_event_destroy(event); | |
7898 | ||
90983b16 FW |
7899 | err_pmu: |
7900 | if (event->destroy) | |
7901 | event->destroy(event); | |
c464c76e | 7902 | module_put(pmu->module); |
90983b16 | 7903 | err_ns: |
79dff51e MF |
7904 | if (is_cgroup_event(event)) |
7905 | perf_detach_cgroup(event); | |
90983b16 FW |
7906 | if (event->ns) |
7907 | put_pid_ns(event->ns); | |
7908 | kfree(event); | |
7909 | ||
7910 | return ERR_PTR(err); | |
0793a61d TG |
7911 | } |
7912 | ||
cdd6c482 IM |
7913 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7914 | struct perf_event_attr *attr) | |
974802ea | 7915 | { |
974802ea | 7916 | u32 size; |
cdf8073d | 7917 | int ret; |
974802ea PZ |
7918 | |
7919 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7920 | return -EFAULT; | |
7921 | ||
7922 | /* | |
7923 | * zero the full structure, so that a short copy will be nice. | |
7924 | */ | |
7925 | memset(attr, 0, sizeof(*attr)); | |
7926 | ||
7927 | ret = get_user(size, &uattr->size); | |
7928 | if (ret) | |
7929 | return ret; | |
7930 | ||
7931 | if (size > PAGE_SIZE) /* silly large */ | |
7932 | goto err_size; | |
7933 | ||
7934 | if (!size) /* abi compat */ | |
7935 | size = PERF_ATTR_SIZE_VER0; | |
7936 | ||
7937 | if (size < PERF_ATTR_SIZE_VER0) | |
7938 | goto err_size; | |
7939 | ||
7940 | /* | |
7941 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7942 | * ensure all the unknown bits are 0 - i.e. new |
7943 | * user-space does not rely on any kernel feature | |
7944 | * extensions we dont know about yet. | |
974802ea PZ |
7945 | */ |
7946 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7947 | unsigned char __user *addr; |
7948 | unsigned char __user *end; | |
7949 | unsigned char val; | |
974802ea | 7950 | |
cdf8073d IS |
7951 | addr = (void __user *)uattr + sizeof(*attr); |
7952 | end = (void __user *)uattr + size; | |
974802ea | 7953 | |
cdf8073d | 7954 | for (; addr < end; addr++) { |
974802ea PZ |
7955 | ret = get_user(val, addr); |
7956 | if (ret) | |
7957 | return ret; | |
7958 | if (val) | |
7959 | goto err_size; | |
7960 | } | |
b3e62e35 | 7961 | size = sizeof(*attr); |
974802ea PZ |
7962 | } |
7963 | ||
7964 | ret = copy_from_user(attr, uattr, size); | |
7965 | if (ret) | |
7966 | return -EFAULT; | |
7967 | ||
cd757645 | 7968 | if (attr->__reserved_1) |
974802ea PZ |
7969 | return -EINVAL; |
7970 | ||
7971 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7972 | return -EINVAL; | |
7973 | ||
7974 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
7975 | return -EINVAL; | |
7976 | ||
bce38cd5 SE |
7977 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
7978 | u64 mask = attr->branch_sample_type; | |
7979 | ||
7980 | /* only using defined bits */ | |
7981 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
7982 | return -EINVAL; | |
7983 | ||
7984 | /* at least one branch bit must be set */ | |
7985 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
7986 | return -EINVAL; | |
7987 | ||
bce38cd5 SE |
7988 | /* propagate priv level, when not set for branch */ |
7989 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
7990 | ||
7991 | /* exclude_kernel checked on syscall entry */ | |
7992 | if (!attr->exclude_kernel) | |
7993 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
7994 | ||
7995 | if (!attr->exclude_user) | |
7996 | mask |= PERF_SAMPLE_BRANCH_USER; | |
7997 | ||
7998 | if (!attr->exclude_hv) | |
7999 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8000 | /* | |
8001 | * adjust user setting (for HW filter setup) | |
8002 | */ | |
8003 | attr->branch_sample_type = mask; | |
8004 | } | |
e712209a SE |
8005 | /* privileged levels capture (kernel, hv): check permissions */ |
8006 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8007 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8008 | return -EACCES; | |
bce38cd5 | 8009 | } |
4018994f | 8010 | |
c5ebcedb | 8011 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8012 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8013 | if (ret) |
8014 | return ret; | |
8015 | } | |
8016 | ||
8017 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8018 | if (!arch_perf_have_user_stack_dump()) | |
8019 | return -ENOSYS; | |
8020 | ||
8021 | /* | |
8022 | * We have __u32 type for the size, but so far | |
8023 | * we can only use __u16 as maximum due to the | |
8024 | * __u16 sample size limit. | |
8025 | */ | |
8026 | if (attr->sample_stack_user >= USHRT_MAX) | |
8027 | ret = -EINVAL; | |
8028 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8029 | ret = -EINVAL; | |
8030 | } | |
4018994f | 8031 | |
60e2364e SE |
8032 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8033 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8034 | out: |
8035 | return ret; | |
8036 | ||
8037 | err_size: | |
8038 | put_user(sizeof(*attr), &uattr->size); | |
8039 | ret = -E2BIG; | |
8040 | goto out; | |
8041 | } | |
8042 | ||
ac9721f3 PZ |
8043 | static int |
8044 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8045 | { |
b69cf536 | 8046 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8047 | int ret = -EINVAL; |
8048 | ||
ac9721f3 | 8049 | if (!output_event) |
a4be7c27 PZ |
8050 | goto set; |
8051 | ||
ac9721f3 PZ |
8052 | /* don't allow circular references */ |
8053 | if (event == output_event) | |
a4be7c27 PZ |
8054 | goto out; |
8055 | ||
0f139300 PZ |
8056 | /* |
8057 | * Don't allow cross-cpu buffers | |
8058 | */ | |
8059 | if (output_event->cpu != event->cpu) | |
8060 | goto out; | |
8061 | ||
8062 | /* | |
76369139 | 8063 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8064 | */ |
8065 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8066 | goto out; | |
8067 | ||
34f43927 PZ |
8068 | /* |
8069 | * Mixing clocks in the same buffer is trouble you don't need. | |
8070 | */ | |
8071 | if (output_event->clock != event->clock) | |
8072 | goto out; | |
8073 | ||
45bfb2e5 PZ |
8074 | /* |
8075 | * If both events generate aux data, they must be on the same PMU | |
8076 | */ | |
8077 | if (has_aux(event) && has_aux(output_event) && | |
8078 | event->pmu != output_event->pmu) | |
8079 | goto out; | |
8080 | ||
a4be7c27 | 8081 | set: |
cdd6c482 | 8082 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8083 | /* Can't redirect output if we've got an active mmap() */ |
8084 | if (atomic_read(&event->mmap_count)) | |
8085 | goto unlock; | |
a4be7c27 | 8086 | |
ac9721f3 | 8087 | if (output_event) { |
76369139 FW |
8088 | /* get the rb we want to redirect to */ |
8089 | rb = ring_buffer_get(output_event); | |
8090 | if (!rb) | |
ac9721f3 | 8091 | goto unlock; |
a4be7c27 PZ |
8092 | } |
8093 | ||
b69cf536 | 8094 | ring_buffer_attach(event, rb); |
9bb5d40c | 8095 | |
a4be7c27 | 8096 | ret = 0; |
ac9721f3 PZ |
8097 | unlock: |
8098 | mutex_unlock(&event->mmap_mutex); | |
8099 | ||
a4be7c27 | 8100 | out: |
a4be7c27 PZ |
8101 | return ret; |
8102 | } | |
8103 | ||
f63a8daa PZ |
8104 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8105 | { | |
8106 | if (b < a) | |
8107 | swap(a, b); | |
8108 | ||
8109 | mutex_lock(a); | |
8110 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8111 | } | |
8112 | ||
34f43927 PZ |
8113 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8114 | { | |
8115 | bool nmi_safe = false; | |
8116 | ||
8117 | switch (clk_id) { | |
8118 | case CLOCK_MONOTONIC: | |
8119 | event->clock = &ktime_get_mono_fast_ns; | |
8120 | nmi_safe = true; | |
8121 | break; | |
8122 | ||
8123 | case CLOCK_MONOTONIC_RAW: | |
8124 | event->clock = &ktime_get_raw_fast_ns; | |
8125 | nmi_safe = true; | |
8126 | break; | |
8127 | ||
8128 | case CLOCK_REALTIME: | |
8129 | event->clock = &ktime_get_real_ns; | |
8130 | break; | |
8131 | ||
8132 | case CLOCK_BOOTTIME: | |
8133 | event->clock = &ktime_get_boot_ns; | |
8134 | break; | |
8135 | ||
8136 | case CLOCK_TAI: | |
8137 | event->clock = &ktime_get_tai_ns; | |
8138 | break; | |
8139 | ||
8140 | default: | |
8141 | return -EINVAL; | |
8142 | } | |
8143 | ||
8144 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8145 | return -EINVAL; | |
8146 | ||
8147 | return 0; | |
8148 | } | |
8149 | ||
0793a61d | 8150 | /** |
cdd6c482 | 8151 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8152 | * |
cdd6c482 | 8153 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8154 | * @pid: target pid |
9f66a381 | 8155 | * @cpu: target cpu |
cdd6c482 | 8156 | * @group_fd: group leader event fd |
0793a61d | 8157 | */ |
cdd6c482 IM |
8158 | SYSCALL_DEFINE5(perf_event_open, |
8159 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8160 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8161 | { |
b04243ef PZ |
8162 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8163 | struct perf_event *event, *sibling; | |
cdd6c482 | 8164 | struct perf_event_attr attr; |
f63a8daa | 8165 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8166 | struct file *event_file = NULL; |
2903ff01 | 8167 | struct fd group = {NULL, 0}; |
38a81da2 | 8168 | struct task_struct *task = NULL; |
89a1e187 | 8169 | struct pmu *pmu; |
ea635c64 | 8170 | int event_fd; |
b04243ef | 8171 | int move_group = 0; |
dc86cabe | 8172 | int err; |
a21b0b35 | 8173 | int f_flags = O_RDWR; |
79dff51e | 8174 | int cgroup_fd = -1; |
0793a61d | 8175 | |
2743a5b0 | 8176 | /* for future expandability... */ |
e5d1367f | 8177 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8178 | return -EINVAL; |
8179 | ||
dc86cabe IM |
8180 | err = perf_copy_attr(attr_uptr, &attr); |
8181 | if (err) | |
8182 | return err; | |
eab656ae | 8183 | |
0764771d PZ |
8184 | if (!attr.exclude_kernel) { |
8185 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8186 | return -EACCES; | |
8187 | } | |
8188 | ||
df58ab24 | 8189 | if (attr.freq) { |
cdd6c482 | 8190 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8191 | return -EINVAL; |
0819b2e3 PZ |
8192 | } else { |
8193 | if (attr.sample_period & (1ULL << 63)) | |
8194 | return -EINVAL; | |
df58ab24 PZ |
8195 | } |
8196 | ||
e5d1367f SE |
8197 | /* |
8198 | * In cgroup mode, the pid argument is used to pass the fd | |
8199 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8200 | * designates the cpu on which to monitor threads from that | |
8201 | * cgroup. | |
8202 | */ | |
8203 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8204 | return -EINVAL; | |
8205 | ||
a21b0b35 YD |
8206 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8207 | f_flags |= O_CLOEXEC; | |
8208 | ||
8209 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8210 | if (event_fd < 0) |
8211 | return event_fd; | |
8212 | ||
ac9721f3 | 8213 | if (group_fd != -1) { |
2903ff01 AV |
8214 | err = perf_fget_light(group_fd, &group); |
8215 | if (err) | |
d14b12d7 | 8216 | goto err_fd; |
2903ff01 | 8217 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8218 | if (flags & PERF_FLAG_FD_OUTPUT) |
8219 | output_event = group_leader; | |
8220 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8221 | group_leader = NULL; | |
8222 | } | |
8223 | ||
e5d1367f | 8224 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8225 | task = find_lively_task_by_vpid(pid); |
8226 | if (IS_ERR(task)) { | |
8227 | err = PTR_ERR(task); | |
8228 | goto err_group_fd; | |
8229 | } | |
8230 | } | |
8231 | ||
1f4ee503 PZ |
8232 | if (task && group_leader && |
8233 | group_leader->attr.inherit != attr.inherit) { | |
8234 | err = -EINVAL; | |
8235 | goto err_task; | |
8236 | } | |
8237 | ||
fbfc623f YZ |
8238 | get_online_cpus(); |
8239 | ||
79dff51e MF |
8240 | if (flags & PERF_FLAG_PID_CGROUP) |
8241 | cgroup_fd = pid; | |
8242 | ||
4dc0da86 | 8243 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8244 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8245 | if (IS_ERR(event)) { |
8246 | err = PTR_ERR(event); | |
1f4ee503 | 8247 | goto err_cpus; |
d14b12d7 SE |
8248 | } |
8249 | ||
53b25335 VW |
8250 | if (is_sampling_event(event)) { |
8251 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8252 | err = -ENOTSUPP; | |
8253 | goto err_alloc; | |
8254 | } | |
8255 | } | |
8256 | ||
766d6c07 FW |
8257 | account_event(event); |
8258 | ||
89a1e187 PZ |
8259 | /* |
8260 | * Special case software events and allow them to be part of | |
8261 | * any hardware group. | |
8262 | */ | |
8263 | pmu = event->pmu; | |
b04243ef | 8264 | |
34f43927 PZ |
8265 | if (attr.use_clockid) { |
8266 | err = perf_event_set_clock(event, attr.clockid); | |
8267 | if (err) | |
8268 | goto err_alloc; | |
8269 | } | |
8270 | ||
b04243ef PZ |
8271 | if (group_leader && |
8272 | (is_software_event(event) != is_software_event(group_leader))) { | |
8273 | if (is_software_event(event)) { | |
8274 | /* | |
8275 | * If event and group_leader are not both a software | |
8276 | * event, and event is, then group leader is not. | |
8277 | * | |
8278 | * Allow the addition of software events to !software | |
8279 | * groups, this is safe because software events never | |
8280 | * fail to schedule. | |
8281 | */ | |
8282 | pmu = group_leader->pmu; | |
8283 | } else if (is_software_event(group_leader) && | |
8284 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8285 | /* | |
8286 | * In case the group is a pure software group, and we | |
8287 | * try to add a hardware event, move the whole group to | |
8288 | * the hardware context. | |
8289 | */ | |
8290 | move_group = 1; | |
8291 | } | |
8292 | } | |
89a1e187 PZ |
8293 | |
8294 | /* | |
8295 | * Get the target context (task or percpu): | |
8296 | */ | |
4af57ef2 | 8297 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8298 | if (IS_ERR(ctx)) { |
8299 | err = PTR_ERR(ctx); | |
c6be5a5c | 8300 | goto err_alloc; |
89a1e187 PZ |
8301 | } |
8302 | ||
bed5b25a AS |
8303 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8304 | err = -EBUSY; | |
8305 | goto err_context; | |
8306 | } | |
8307 | ||
fd1edb3a PZ |
8308 | if (task) { |
8309 | put_task_struct(task); | |
8310 | task = NULL; | |
8311 | } | |
8312 | ||
ccff286d | 8313 | /* |
cdd6c482 | 8314 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8315 | */ |
ac9721f3 | 8316 | if (group_leader) { |
dc86cabe | 8317 | err = -EINVAL; |
04289bb9 | 8318 | |
04289bb9 | 8319 | /* |
ccff286d IM |
8320 | * Do not allow a recursive hierarchy (this new sibling |
8321 | * becoming part of another group-sibling): | |
8322 | */ | |
8323 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8324 | goto err_context; |
34f43927 PZ |
8325 | |
8326 | /* All events in a group should have the same clock */ | |
8327 | if (group_leader->clock != event->clock) | |
8328 | goto err_context; | |
8329 | ||
ccff286d IM |
8330 | /* |
8331 | * Do not allow to attach to a group in a different | |
8332 | * task or CPU context: | |
04289bb9 | 8333 | */ |
b04243ef | 8334 | if (move_group) { |
c3c87e77 PZ |
8335 | /* |
8336 | * Make sure we're both on the same task, or both | |
8337 | * per-cpu events. | |
8338 | */ | |
8339 | if (group_leader->ctx->task != ctx->task) | |
8340 | goto err_context; | |
8341 | ||
8342 | /* | |
8343 | * Make sure we're both events for the same CPU; | |
8344 | * grouping events for different CPUs is broken; since | |
8345 | * you can never concurrently schedule them anyhow. | |
8346 | */ | |
8347 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8348 | goto err_context; |
8349 | } else { | |
8350 | if (group_leader->ctx != ctx) | |
8351 | goto err_context; | |
8352 | } | |
8353 | ||
3b6f9e5c PM |
8354 | /* |
8355 | * Only a group leader can be exclusive or pinned | |
8356 | */ | |
0d48696f | 8357 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8358 | goto err_context; |
ac9721f3 PZ |
8359 | } |
8360 | ||
8361 | if (output_event) { | |
8362 | err = perf_event_set_output(event, output_event); | |
8363 | if (err) | |
c3f00c70 | 8364 | goto err_context; |
ac9721f3 | 8365 | } |
0793a61d | 8366 | |
a21b0b35 YD |
8367 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8368 | f_flags); | |
ea635c64 AV |
8369 | if (IS_ERR(event_file)) { |
8370 | err = PTR_ERR(event_file); | |
c3f00c70 | 8371 | goto err_context; |
ea635c64 | 8372 | } |
9b51f66d | 8373 | |
b04243ef | 8374 | if (move_group) { |
f63a8daa | 8375 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8376 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8377 | } else { | |
8378 | mutex_lock(&ctx->mutex); | |
8379 | } | |
8380 | ||
a723968c PZ |
8381 | if (!perf_event_validate_size(event)) { |
8382 | err = -E2BIG; | |
8383 | goto err_locked; | |
8384 | } | |
8385 | ||
f55fc2a5 PZ |
8386 | /* |
8387 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8388 | * because we need to serialize with concurrent event creation. | |
8389 | */ | |
8390 | if (!exclusive_event_installable(event, ctx)) { | |
8391 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8392 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8393 | |
f55fc2a5 PZ |
8394 | err = -EBUSY; |
8395 | goto err_locked; | |
8396 | } | |
f63a8daa | 8397 | |
f55fc2a5 PZ |
8398 | WARN_ON_ONCE(ctx->parent_ctx); |
8399 | ||
8400 | if (move_group) { | |
f63a8daa PZ |
8401 | /* |
8402 | * See perf_event_ctx_lock() for comments on the details | |
8403 | * of swizzling perf_event::ctx. | |
8404 | */ | |
46ce0fe9 | 8405 | perf_remove_from_context(group_leader, false); |
0231bb53 | 8406 | |
b04243ef PZ |
8407 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8408 | group_entry) { | |
46ce0fe9 | 8409 | perf_remove_from_context(sibling, false); |
b04243ef PZ |
8410 | put_ctx(gctx); |
8411 | } | |
b04243ef | 8412 | |
f63a8daa PZ |
8413 | /* |
8414 | * Wait for everybody to stop referencing the events through | |
8415 | * the old lists, before installing it on new lists. | |
8416 | */ | |
0cda4c02 | 8417 | synchronize_rcu(); |
f63a8daa | 8418 | |
8f95b435 PZI |
8419 | /* |
8420 | * Install the group siblings before the group leader. | |
8421 | * | |
8422 | * Because a group leader will try and install the entire group | |
8423 | * (through the sibling list, which is still in-tact), we can | |
8424 | * end up with siblings installed in the wrong context. | |
8425 | * | |
8426 | * By installing siblings first we NO-OP because they're not | |
8427 | * reachable through the group lists. | |
8428 | */ | |
b04243ef PZ |
8429 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8430 | group_entry) { | |
8f95b435 | 8431 | perf_event__state_init(sibling); |
9fc81d87 | 8432 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8433 | get_ctx(ctx); |
8434 | } | |
8f95b435 PZI |
8435 | |
8436 | /* | |
8437 | * Removing from the context ends up with disabled | |
8438 | * event. What we want here is event in the initial | |
8439 | * startup state, ready to be add into new context. | |
8440 | */ | |
8441 | perf_event__state_init(group_leader); | |
8442 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8443 | get_ctx(ctx); | |
b04243ef | 8444 | |
f55fc2a5 PZ |
8445 | /* |
8446 | * Now that all events are installed in @ctx, nothing | |
8447 | * references @gctx anymore, so drop the last reference we have | |
8448 | * on it. | |
8449 | */ | |
8450 | put_ctx(gctx); | |
bed5b25a AS |
8451 | } |
8452 | ||
f73e22ab PZ |
8453 | /* |
8454 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8455 | * that we're serialized against further additions and before | |
8456 | * perf_install_in_context() which is the point the event is active and | |
8457 | * can use these values. | |
8458 | */ | |
8459 | perf_event__header_size(event); | |
8460 | perf_event__id_header_size(event); | |
8461 | ||
e2d37cd2 | 8462 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8463 | perf_unpin_context(ctx); |
f63a8daa | 8464 | |
f55fc2a5 | 8465 | if (move_group) |
f63a8daa | 8466 | mutex_unlock(&gctx->mutex); |
d859e29f | 8467 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8468 | |
fbfc623f YZ |
8469 | put_online_cpus(); |
8470 | ||
cdd6c482 | 8471 | event->owner = current; |
8882135b | 8472 | |
cdd6c482 IM |
8473 | mutex_lock(¤t->perf_event_mutex); |
8474 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8475 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8476 | |
8a49542c PZ |
8477 | /* |
8478 | * Drop the reference on the group_event after placing the | |
8479 | * new event on the sibling_list. This ensures destruction | |
8480 | * of the group leader will find the pointer to itself in | |
8481 | * perf_group_detach(). | |
8482 | */ | |
2903ff01 | 8483 | fdput(group); |
ea635c64 AV |
8484 | fd_install(event_fd, event_file); |
8485 | return event_fd; | |
0793a61d | 8486 | |
f55fc2a5 PZ |
8487 | err_locked: |
8488 | if (move_group) | |
8489 | mutex_unlock(&gctx->mutex); | |
8490 | mutex_unlock(&ctx->mutex); | |
8491 | /* err_file: */ | |
8492 | fput(event_file); | |
c3f00c70 | 8493 | err_context: |
fe4b04fa | 8494 | perf_unpin_context(ctx); |
ea635c64 | 8495 | put_ctx(ctx); |
c6be5a5c | 8496 | err_alloc: |
ea635c64 | 8497 | free_event(event); |
1f4ee503 | 8498 | err_cpus: |
fbfc623f | 8499 | put_online_cpus(); |
1f4ee503 | 8500 | err_task: |
e7d0bc04 PZ |
8501 | if (task) |
8502 | put_task_struct(task); | |
89a1e187 | 8503 | err_group_fd: |
2903ff01 | 8504 | fdput(group); |
ea635c64 AV |
8505 | err_fd: |
8506 | put_unused_fd(event_fd); | |
dc86cabe | 8507 | return err; |
0793a61d TG |
8508 | } |
8509 | ||
fb0459d7 AV |
8510 | /** |
8511 | * perf_event_create_kernel_counter | |
8512 | * | |
8513 | * @attr: attributes of the counter to create | |
8514 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8515 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8516 | */ |
8517 | struct perf_event * | |
8518 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8519 | struct task_struct *task, |
4dc0da86 AK |
8520 | perf_overflow_handler_t overflow_handler, |
8521 | void *context) | |
fb0459d7 | 8522 | { |
fb0459d7 | 8523 | struct perf_event_context *ctx; |
c3f00c70 | 8524 | struct perf_event *event; |
fb0459d7 | 8525 | int err; |
d859e29f | 8526 | |
fb0459d7 AV |
8527 | /* |
8528 | * Get the target context (task or percpu): | |
8529 | */ | |
d859e29f | 8530 | |
4dc0da86 | 8531 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8532 | overflow_handler, context, -1); |
c3f00c70 PZ |
8533 | if (IS_ERR(event)) { |
8534 | err = PTR_ERR(event); | |
8535 | goto err; | |
8536 | } | |
d859e29f | 8537 | |
f8697762 JO |
8538 | /* Mark owner so we could distinguish it from user events. */ |
8539 | event->owner = EVENT_OWNER_KERNEL; | |
8540 | ||
766d6c07 FW |
8541 | account_event(event); |
8542 | ||
4af57ef2 | 8543 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8544 | if (IS_ERR(ctx)) { |
8545 | err = PTR_ERR(ctx); | |
c3f00c70 | 8546 | goto err_free; |
d859e29f | 8547 | } |
fb0459d7 | 8548 | |
fb0459d7 AV |
8549 | WARN_ON_ONCE(ctx->parent_ctx); |
8550 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8551 | if (!exclusive_event_installable(event, ctx)) { |
8552 | mutex_unlock(&ctx->mutex); | |
8553 | perf_unpin_context(ctx); | |
8554 | put_ctx(ctx); | |
8555 | err = -EBUSY; | |
8556 | goto err_free; | |
8557 | } | |
8558 | ||
fb0459d7 | 8559 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8560 | perf_unpin_context(ctx); |
fb0459d7 AV |
8561 | mutex_unlock(&ctx->mutex); |
8562 | ||
fb0459d7 AV |
8563 | return event; |
8564 | ||
c3f00c70 PZ |
8565 | err_free: |
8566 | free_event(event); | |
8567 | err: | |
c6567f64 | 8568 | return ERR_PTR(err); |
9b51f66d | 8569 | } |
fb0459d7 | 8570 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8571 | |
0cda4c02 YZ |
8572 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8573 | { | |
8574 | struct perf_event_context *src_ctx; | |
8575 | struct perf_event_context *dst_ctx; | |
8576 | struct perf_event *event, *tmp; | |
8577 | LIST_HEAD(events); | |
8578 | ||
8579 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8580 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8581 | ||
f63a8daa PZ |
8582 | /* |
8583 | * See perf_event_ctx_lock() for comments on the details | |
8584 | * of swizzling perf_event::ctx. | |
8585 | */ | |
8586 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8587 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8588 | event_entry) { | |
46ce0fe9 | 8589 | perf_remove_from_context(event, false); |
9a545de0 | 8590 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8591 | put_ctx(src_ctx); |
9886167d | 8592 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8593 | } |
0cda4c02 | 8594 | |
8f95b435 PZI |
8595 | /* |
8596 | * Wait for the events to quiesce before re-instating them. | |
8597 | */ | |
0cda4c02 YZ |
8598 | synchronize_rcu(); |
8599 | ||
8f95b435 PZI |
8600 | /* |
8601 | * Re-instate events in 2 passes. | |
8602 | * | |
8603 | * Skip over group leaders and only install siblings on this first | |
8604 | * pass, siblings will not get enabled without a leader, however a | |
8605 | * leader will enable its siblings, even if those are still on the old | |
8606 | * context. | |
8607 | */ | |
8608 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8609 | if (event->group_leader == event) | |
8610 | continue; | |
8611 | ||
8612 | list_del(&event->migrate_entry); | |
8613 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8614 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8615 | account_event_cpu(event, dst_cpu); | |
8616 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8617 | get_ctx(dst_ctx); | |
8618 | } | |
8619 | ||
8620 | /* | |
8621 | * Once all the siblings are setup properly, install the group leaders | |
8622 | * to make it go. | |
8623 | */ | |
9886167d PZ |
8624 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8625 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8626 | if (event->state >= PERF_EVENT_STATE_OFF) |
8627 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8628 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8629 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8630 | get_ctx(dst_ctx); | |
8631 | } | |
8632 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8633 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8634 | } |
8635 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8636 | ||
cdd6c482 | 8637 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8638 | struct task_struct *child) |
d859e29f | 8639 | { |
cdd6c482 | 8640 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8641 | u64 child_val; |
d859e29f | 8642 | |
cdd6c482 IM |
8643 | if (child_event->attr.inherit_stat) |
8644 | perf_event_read_event(child_event, child); | |
38b200d6 | 8645 | |
b5e58793 | 8646 | child_val = perf_event_count(child_event); |
d859e29f PM |
8647 | |
8648 | /* | |
8649 | * Add back the child's count to the parent's count: | |
8650 | */ | |
a6e6dea6 | 8651 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8652 | atomic64_add(child_event->total_time_enabled, |
8653 | &parent_event->child_total_time_enabled); | |
8654 | atomic64_add(child_event->total_time_running, | |
8655 | &parent_event->child_total_time_running); | |
d859e29f PM |
8656 | |
8657 | /* | |
cdd6c482 | 8658 | * Remove this event from the parent's list |
d859e29f | 8659 | */ |
cdd6c482 IM |
8660 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
8661 | mutex_lock(&parent_event->child_mutex); | |
8662 | list_del_init(&child_event->child_list); | |
8663 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f | 8664 | |
dc633982 JO |
8665 | /* |
8666 | * Make sure user/parent get notified, that we just | |
8667 | * lost one event. | |
8668 | */ | |
8669 | perf_event_wakeup(parent_event); | |
8670 | ||
d859e29f | 8671 | /* |
cdd6c482 | 8672 | * Release the parent event, if this was the last |
d859e29f PM |
8673 | * reference to it. |
8674 | */ | |
a6fa941d | 8675 | put_event(parent_event); |
d859e29f PM |
8676 | } |
8677 | ||
9b51f66d | 8678 | static void |
cdd6c482 IM |
8679 | __perf_event_exit_task(struct perf_event *child_event, |
8680 | struct perf_event_context *child_ctx, | |
38b200d6 | 8681 | struct task_struct *child) |
9b51f66d | 8682 | { |
1903d50c PZ |
8683 | /* |
8684 | * Do not destroy the 'original' grouping; because of the context | |
8685 | * switch optimization the original events could've ended up in a | |
8686 | * random child task. | |
8687 | * | |
8688 | * If we were to destroy the original group, all group related | |
8689 | * operations would cease to function properly after this random | |
8690 | * child dies. | |
8691 | * | |
8692 | * Do destroy all inherited groups, we don't care about those | |
8693 | * and being thorough is better. | |
8694 | */ | |
32132a3d PZ |
8695 | raw_spin_lock_irq(&child_ctx->lock); |
8696 | WARN_ON_ONCE(child_ctx->is_active); | |
8697 | ||
8698 | if (!!child_event->parent) | |
8699 | perf_group_detach(child_event); | |
8700 | list_del_event(child_event, child_ctx); | |
8701 | raw_spin_unlock_irq(&child_ctx->lock); | |
0cc0c027 | 8702 | |
9b51f66d | 8703 | /* |
38b435b1 | 8704 | * It can happen that the parent exits first, and has events |
9b51f66d | 8705 | * that are still around due to the child reference. These |
38b435b1 | 8706 | * events need to be zapped. |
9b51f66d | 8707 | */ |
38b435b1 | 8708 | if (child_event->parent) { |
cdd6c482 IM |
8709 | sync_child_event(child_event, child); |
8710 | free_event(child_event); | |
179033b3 JO |
8711 | } else { |
8712 | child_event->state = PERF_EVENT_STATE_EXIT; | |
8713 | perf_event_wakeup(child_event); | |
4bcf349a | 8714 | } |
9b51f66d IM |
8715 | } |
8716 | ||
8dc85d54 | 8717 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8718 | { |
ebf905fc | 8719 | struct perf_event *child_event, *next; |
211de6eb | 8720 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
9b51f66d | 8721 | |
4e93ad60 | 8722 | if (likely(!child->perf_event_ctxp[ctxn])) |
9b51f66d IM |
8723 | return; |
8724 | ||
32132a3d PZ |
8725 | local_irq_disable(); |
8726 | WARN_ON_ONCE(child != current); | |
ad3a37de PM |
8727 | /* |
8728 | * We can't reschedule here because interrupts are disabled, | |
32132a3d | 8729 | * and child must be current. |
ad3a37de | 8730 | */ |
806839b2 | 8731 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
8732 | |
8733 | /* | |
8734 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 8735 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
8736 | * incremented the context's refcount before we do put_ctx below. |
8737 | */ | |
e625cce1 | 8738 | raw_spin_lock(&child_ctx->lock); |
3e349507 | 8739 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
8dc85d54 | 8740 | child->perf_event_ctxp[ctxn] = NULL; |
4a1c0f26 | 8741 | |
71a851b4 PZ |
8742 | /* |
8743 | * If this context is a clone; unclone it so it can't get | |
8744 | * swapped to another process while we're removing all | |
cdd6c482 | 8745 | * the events from it. |
71a851b4 | 8746 | */ |
211de6eb | 8747 | clone_ctx = unclone_ctx(child_ctx); |
5e942bb3 | 8748 | update_context_time(child_ctx); |
32132a3d | 8749 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8750 | |
211de6eb PZ |
8751 | if (clone_ctx) |
8752 | put_ctx(clone_ctx); | |
4a1c0f26 | 8753 | |
9f498cc5 | 8754 | /* |
cdd6c482 IM |
8755 | * Report the task dead after unscheduling the events so that we |
8756 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8757 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8758 | */ |
cdd6c482 | 8759 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8760 | |
66fff224 PZ |
8761 | /* |
8762 | * We can recurse on the same lock type through: | |
8763 | * | |
cdd6c482 IM |
8764 | * __perf_event_exit_task() |
8765 | * sync_child_event() | |
a6fa941d AV |
8766 | * put_event() |
8767 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
8768 | * |
8769 | * But since its the parent context it won't be the same instance. | |
8770 | */ | |
a0507c84 | 8771 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 8772 | |
ebf905fc | 8773 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
cdd6c482 | 8774 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 | 8775 | |
a63eaf34 PM |
8776 | mutex_unlock(&child_ctx->mutex); |
8777 | ||
8778 | put_ctx(child_ctx); | |
9b51f66d IM |
8779 | } |
8780 | ||
8dc85d54 PZ |
8781 | /* |
8782 | * When a child task exits, feed back event values to parent events. | |
8783 | */ | |
8784 | void perf_event_exit_task(struct task_struct *child) | |
8785 | { | |
8882135b | 8786 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8787 | int ctxn; |
8788 | ||
8882135b PZ |
8789 | mutex_lock(&child->perf_event_mutex); |
8790 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8791 | owner_entry) { | |
8792 | list_del_init(&event->owner_entry); | |
8793 | ||
8794 | /* | |
8795 | * Ensure the list deletion is visible before we clear | |
8796 | * the owner, closes a race against perf_release() where | |
8797 | * we need to serialize on the owner->perf_event_mutex. | |
8798 | */ | |
8799 | smp_wmb(); | |
8800 | event->owner = NULL; | |
8801 | } | |
8802 | mutex_unlock(&child->perf_event_mutex); | |
8803 | ||
8dc85d54 PZ |
8804 | for_each_task_context_nr(ctxn) |
8805 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8806 | |
8807 | /* | |
8808 | * The perf_event_exit_task_context calls perf_event_task | |
8809 | * with child's task_ctx, which generates EXIT events for | |
8810 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8811 | * At this point we need to send EXIT events to cpu contexts. | |
8812 | */ | |
8813 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8814 | } |
8815 | ||
889ff015 FW |
8816 | static void perf_free_event(struct perf_event *event, |
8817 | struct perf_event_context *ctx) | |
8818 | { | |
8819 | struct perf_event *parent = event->parent; | |
8820 | ||
8821 | if (WARN_ON_ONCE(!parent)) | |
8822 | return; | |
8823 | ||
8824 | mutex_lock(&parent->child_mutex); | |
8825 | list_del_init(&event->child_list); | |
8826 | mutex_unlock(&parent->child_mutex); | |
8827 | ||
a6fa941d | 8828 | put_event(parent); |
889ff015 | 8829 | |
652884fe | 8830 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8831 | perf_group_detach(event); |
889ff015 | 8832 | list_del_event(event, ctx); |
652884fe | 8833 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8834 | free_event(event); |
8835 | } | |
8836 | ||
bbbee908 | 8837 | /* |
652884fe | 8838 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8839 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8840 | * |
8841 | * Not all locks are strictly required, but take them anyway to be nice and | |
8842 | * help out with the lockdep assertions. | |
bbbee908 | 8843 | */ |
cdd6c482 | 8844 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8845 | { |
8dc85d54 | 8846 | struct perf_event_context *ctx; |
cdd6c482 | 8847 | struct perf_event *event, *tmp; |
8dc85d54 | 8848 | int ctxn; |
bbbee908 | 8849 | |
8dc85d54 PZ |
8850 | for_each_task_context_nr(ctxn) { |
8851 | ctx = task->perf_event_ctxp[ctxn]; | |
8852 | if (!ctx) | |
8853 | continue; | |
bbbee908 | 8854 | |
8dc85d54 | 8855 | mutex_lock(&ctx->mutex); |
bbbee908 | 8856 | again: |
8dc85d54 PZ |
8857 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8858 | group_entry) | |
8859 | perf_free_event(event, ctx); | |
bbbee908 | 8860 | |
8dc85d54 PZ |
8861 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8862 | group_entry) | |
8863 | perf_free_event(event, ctx); | |
bbbee908 | 8864 | |
8dc85d54 PZ |
8865 | if (!list_empty(&ctx->pinned_groups) || |
8866 | !list_empty(&ctx->flexible_groups)) | |
8867 | goto again; | |
bbbee908 | 8868 | |
8dc85d54 | 8869 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8870 | |
8dc85d54 PZ |
8871 | put_ctx(ctx); |
8872 | } | |
889ff015 FW |
8873 | } |
8874 | ||
4e231c79 PZ |
8875 | void perf_event_delayed_put(struct task_struct *task) |
8876 | { | |
8877 | int ctxn; | |
8878 | ||
8879 | for_each_task_context_nr(ctxn) | |
8880 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8881 | } | |
8882 | ||
ffe8690c KX |
8883 | struct perf_event *perf_event_get(unsigned int fd) |
8884 | { | |
8885 | int err; | |
8886 | struct fd f; | |
8887 | struct perf_event *event; | |
8888 | ||
8889 | err = perf_fget_light(fd, &f); | |
8890 | if (err) | |
8891 | return ERR_PTR(err); | |
8892 | ||
8893 | event = f.file->private_data; | |
8894 | atomic_long_inc(&event->refcount); | |
8895 | fdput(f); | |
8896 | ||
8897 | return event; | |
8898 | } | |
8899 | ||
8900 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8901 | { | |
8902 | if (!event) | |
8903 | return ERR_PTR(-EINVAL); | |
8904 | ||
8905 | return &event->attr; | |
8906 | } | |
8907 | ||
97dee4f3 PZ |
8908 | /* |
8909 | * inherit a event from parent task to child task: | |
8910 | */ | |
8911 | static struct perf_event * | |
8912 | inherit_event(struct perf_event *parent_event, | |
8913 | struct task_struct *parent, | |
8914 | struct perf_event_context *parent_ctx, | |
8915 | struct task_struct *child, | |
8916 | struct perf_event *group_leader, | |
8917 | struct perf_event_context *child_ctx) | |
8918 | { | |
1929def9 | 8919 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8920 | struct perf_event *child_event; |
cee010ec | 8921 | unsigned long flags; |
97dee4f3 PZ |
8922 | |
8923 | /* | |
8924 | * Instead of creating recursive hierarchies of events, | |
8925 | * we link inherited events back to the original parent, | |
8926 | * which has a filp for sure, which we use as the reference | |
8927 | * count: | |
8928 | */ | |
8929 | if (parent_event->parent) | |
8930 | parent_event = parent_event->parent; | |
8931 | ||
8932 | child_event = perf_event_alloc(&parent_event->attr, | |
8933 | parent_event->cpu, | |
d580ff86 | 8934 | child, |
97dee4f3 | 8935 | group_leader, parent_event, |
79dff51e | 8936 | NULL, NULL, -1); |
97dee4f3 PZ |
8937 | if (IS_ERR(child_event)) |
8938 | return child_event; | |
a6fa941d | 8939 | |
fadfe7be JO |
8940 | if (is_orphaned_event(parent_event) || |
8941 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
a6fa941d AV |
8942 | free_event(child_event); |
8943 | return NULL; | |
8944 | } | |
8945 | ||
97dee4f3 PZ |
8946 | get_ctx(child_ctx); |
8947 | ||
8948 | /* | |
8949 | * Make the child state follow the state of the parent event, | |
8950 | * not its attr.disabled bit. We hold the parent's mutex, | |
8951 | * so we won't race with perf_event_{en, dis}able_family. | |
8952 | */ | |
1929def9 | 8953 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8954 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8955 | else | |
8956 | child_event->state = PERF_EVENT_STATE_OFF; | |
8957 | ||
8958 | if (parent_event->attr.freq) { | |
8959 | u64 sample_period = parent_event->hw.sample_period; | |
8960 | struct hw_perf_event *hwc = &child_event->hw; | |
8961 | ||
8962 | hwc->sample_period = sample_period; | |
8963 | hwc->last_period = sample_period; | |
8964 | ||
8965 | local64_set(&hwc->period_left, sample_period); | |
8966 | } | |
8967 | ||
8968 | child_event->ctx = child_ctx; | |
8969 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
8970 | child_event->overflow_handler_context |
8971 | = parent_event->overflow_handler_context; | |
97dee4f3 | 8972 | |
614b6780 TG |
8973 | /* |
8974 | * Precalculate sample_data sizes | |
8975 | */ | |
8976 | perf_event__header_size(child_event); | |
6844c09d | 8977 | perf_event__id_header_size(child_event); |
614b6780 | 8978 | |
97dee4f3 PZ |
8979 | /* |
8980 | * Link it up in the child's context: | |
8981 | */ | |
cee010ec | 8982 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 8983 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 8984 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 8985 | |
97dee4f3 PZ |
8986 | /* |
8987 | * Link this into the parent event's child list | |
8988 | */ | |
8989 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8990 | mutex_lock(&parent_event->child_mutex); | |
8991 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
8992 | mutex_unlock(&parent_event->child_mutex); | |
8993 | ||
8994 | return child_event; | |
8995 | } | |
8996 | ||
8997 | static int inherit_group(struct perf_event *parent_event, | |
8998 | struct task_struct *parent, | |
8999 | struct perf_event_context *parent_ctx, | |
9000 | struct task_struct *child, | |
9001 | struct perf_event_context *child_ctx) | |
9002 | { | |
9003 | struct perf_event *leader; | |
9004 | struct perf_event *sub; | |
9005 | struct perf_event *child_ctr; | |
9006 | ||
9007 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9008 | child, NULL, child_ctx); | |
9009 | if (IS_ERR(leader)) | |
9010 | return PTR_ERR(leader); | |
9011 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9012 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9013 | child, leader, child_ctx); | |
9014 | if (IS_ERR(child_ctr)) | |
9015 | return PTR_ERR(child_ctr); | |
9016 | } | |
9017 | return 0; | |
889ff015 FW |
9018 | } |
9019 | ||
9020 | static int | |
9021 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9022 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9023 | struct task_struct *child, int ctxn, |
889ff015 FW |
9024 | int *inherited_all) |
9025 | { | |
9026 | int ret; | |
8dc85d54 | 9027 | struct perf_event_context *child_ctx; |
889ff015 FW |
9028 | |
9029 | if (!event->attr.inherit) { | |
9030 | *inherited_all = 0; | |
9031 | return 0; | |
bbbee908 PZ |
9032 | } |
9033 | ||
fe4b04fa | 9034 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9035 | if (!child_ctx) { |
9036 | /* | |
9037 | * This is executed from the parent task context, so | |
9038 | * inherit events that have been marked for cloning. | |
9039 | * First allocate and initialize a context for the | |
9040 | * child. | |
9041 | */ | |
bbbee908 | 9042 | |
734df5ab | 9043 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9044 | if (!child_ctx) |
9045 | return -ENOMEM; | |
bbbee908 | 9046 | |
8dc85d54 | 9047 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9048 | } |
9049 | ||
9050 | ret = inherit_group(event, parent, parent_ctx, | |
9051 | child, child_ctx); | |
9052 | ||
9053 | if (ret) | |
9054 | *inherited_all = 0; | |
9055 | ||
9056 | return ret; | |
bbbee908 PZ |
9057 | } |
9058 | ||
9b51f66d | 9059 | /* |
cdd6c482 | 9060 | * Initialize the perf_event context in task_struct |
9b51f66d | 9061 | */ |
985c8dcb | 9062 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9063 | { |
889ff015 | 9064 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9065 | struct perf_event_context *cloned_ctx; |
9066 | struct perf_event *event; | |
9b51f66d | 9067 | struct task_struct *parent = current; |
564c2b21 | 9068 | int inherited_all = 1; |
dddd3379 | 9069 | unsigned long flags; |
6ab423e0 | 9070 | int ret = 0; |
9b51f66d | 9071 | |
8dc85d54 | 9072 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9073 | return 0; |
9074 | ||
ad3a37de | 9075 | /* |
25346b93 PM |
9076 | * If the parent's context is a clone, pin it so it won't get |
9077 | * swapped under us. | |
ad3a37de | 9078 | */ |
8dc85d54 | 9079 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9080 | if (!parent_ctx) |
9081 | return 0; | |
25346b93 | 9082 | |
ad3a37de PM |
9083 | /* |
9084 | * No need to check if parent_ctx != NULL here; since we saw | |
9085 | * it non-NULL earlier, the only reason for it to become NULL | |
9086 | * is if we exit, and since we're currently in the middle of | |
9087 | * a fork we can't be exiting at the same time. | |
9088 | */ | |
ad3a37de | 9089 | |
9b51f66d IM |
9090 | /* |
9091 | * Lock the parent list. No need to lock the child - not PID | |
9092 | * hashed yet and not running, so nobody can access it. | |
9093 | */ | |
d859e29f | 9094 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9095 | |
9096 | /* | |
9097 | * We dont have to disable NMIs - we are only looking at | |
9098 | * the list, not manipulating it: | |
9099 | */ | |
889ff015 | 9100 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9101 | ret = inherit_task_group(event, parent, parent_ctx, |
9102 | child, ctxn, &inherited_all); | |
889ff015 FW |
9103 | if (ret) |
9104 | break; | |
9105 | } | |
b93f7978 | 9106 | |
dddd3379 TG |
9107 | /* |
9108 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9109 | * to allocations, but we need to prevent rotation because | |
9110 | * rotate_ctx() will change the list from interrupt context. | |
9111 | */ | |
9112 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9113 | parent_ctx->rotate_disable = 1; | |
9114 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9115 | ||
889ff015 | 9116 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9117 | ret = inherit_task_group(event, parent, parent_ctx, |
9118 | child, ctxn, &inherited_all); | |
889ff015 | 9119 | if (ret) |
9b51f66d | 9120 | break; |
564c2b21 PM |
9121 | } |
9122 | ||
dddd3379 TG |
9123 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9124 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9125 | |
8dc85d54 | 9126 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9127 | |
05cbaa28 | 9128 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9129 | /* |
9130 | * Mark the child context as a clone of the parent | |
9131 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9132 | * |
9133 | * Note that if the parent is a clone, the holding of | |
9134 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9135 | */ |
c5ed5145 | 9136 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9137 | if (cloned_ctx) { |
9138 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9139 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9140 | } else { |
9141 | child_ctx->parent_ctx = parent_ctx; | |
9142 | child_ctx->parent_gen = parent_ctx->generation; | |
9143 | } | |
9144 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9145 | } |
9146 | ||
c5ed5145 | 9147 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9148 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9149 | |
25346b93 | 9150 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9151 | put_ctx(parent_ctx); |
ad3a37de | 9152 | |
6ab423e0 | 9153 | return ret; |
9b51f66d IM |
9154 | } |
9155 | ||
8dc85d54 PZ |
9156 | /* |
9157 | * Initialize the perf_event context in task_struct | |
9158 | */ | |
9159 | int perf_event_init_task(struct task_struct *child) | |
9160 | { | |
9161 | int ctxn, ret; | |
9162 | ||
8550d7cb ON |
9163 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9164 | mutex_init(&child->perf_event_mutex); | |
9165 | INIT_LIST_HEAD(&child->perf_event_list); | |
9166 | ||
8dc85d54 PZ |
9167 | for_each_task_context_nr(ctxn) { |
9168 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9169 | if (ret) { |
9170 | perf_event_free_task(child); | |
8dc85d54 | 9171 | return ret; |
6c72e350 | 9172 | } |
8dc85d54 PZ |
9173 | } |
9174 | ||
9175 | return 0; | |
9176 | } | |
9177 | ||
220b140b PM |
9178 | static void __init perf_event_init_all_cpus(void) |
9179 | { | |
b28ab83c | 9180 | struct swevent_htable *swhash; |
220b140b | 9181 | int cpu; |
220b140b PM |
9182 | |
9183 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9184 | swhash = &per_cpu(swevent_htable, cpu); |
9185 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9186 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9187 | } |
9188 | } | |
9189 | ||
0db0628d | 9190 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9191 | { |
108b02cf | 9192 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9193 | |
b28ab83c | 9194 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9195 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9196 | struct swevent_hlist *hlist; |
9197 | ||
b28ab83c PZ |
9198 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9199 | WARN_ON(!hlist); | |
9200 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9201 | } |
b28ab83c | 9202 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9203 | } |
9204 | ||
2965faa5 | 9205 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9206 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9207 | { |
108b02cf | 9208 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9209 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9210 | struct perf_event *event; | |
0793a61d | 9211 | |
fae3fde6 PZ |
9212 | raw_spin_lock(&ctx->lock); |
9213 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
9214 | __perf_remove_from_context(event, cpuctx, ctx, (void *)(unsigned long)true); | |
9215 | raw_spin_unlock(&ctx->lock); | |
0793a61d | 9216 | } |
108b02cf PZ |
9217 | |
9218 | static void perf_event_exit_cpu_context(int cpu) | |
9219 | { | |
9220 | struct perf_event_context *ctx; | |
9221 | struct pmu *pmu; | |
9222 | int idx; | |
9223 | ||
9224 | idx = srcu_read_lock(&pmus_srcu); | |
9225 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9226 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9227 | |
9228 | mutex_lock(&ctx->mutex); | |
9229 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9230 | mutex_unlock(&ctx->mutex); | |
9231 | } | |
9232 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9233 | } |
9234 | ||
cdd6c482 | 9235 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9236 | { |
e3703f8c | 9237 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9238 | } |
9239 | #else | |
cdd6c482 | 9240 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9241 | #endif |
9242 | ||
c277443c PZ |
9243 | static int |
9244 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9245 | { | |
9246 | int cpu; | |
9247 | ||
9248 | for_each_online_cpu(cpu) | |
9249 | perf_event_exit_cpu(cpu); | |
9250 | ||
9251 | return NOTIFY_OK; | |
9252 | } | |
9253 | ||
9254 | /* | |
9255 | * Run the perf reboot notifier at the very last possible moment so that | |
9256 | * the generic watchdog code runs as long as possible. | |
9257 | */ | |
9258 | static struct notifier_block perf_reboot_notifier = { | |
9259 | .notifier_call = perf_reboot, | |
9260 | .priority = INT_MIN, | |
9261 | }; | |
9262 | ||
0db0628d | 9263 | static int |
0793a61d TG |
9264 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9265 | { | |
9266 | unsigned int cpu = (long)hcpu; | |
9267 | ||
4536e4d1 | 9268 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9269 | |
9270 | case CPU_UP_PREPARE: | |
5e11637e | 9271 | case CPU_DOWN_FAILED: |
cdd6c482 | 9272 | perf_event_init_cpu(cpu); |
0793a61d TG |
9273 | break; |
9274 | ||
5e11637e | 9275 | case CPU_UP_CANCELED: |
0793a61d | 9276 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9277 | perf_event_exit_cpu(cpu); |
0793a61d | 9278 | break; |
0793a61d TG |
9279 | default: |
9280 | break; | |
9281 | } | |
9282 | ||
9283 | return NOTIFY_OK; | |
9284 | } | |
9285 | ||
cdd6c482 | 9286 | void __init perf_event_init(void) |
0793a61d | 9287 | { |
3c502e7a JW |
9288 | int ret; |
9289 | ||
2e80a82a PZ |
9290 | idr_init(&pmu_idr); |
9291 | ||
220b140b | 9292 | perf_event_init_all_cpus(); |
b0a873eb | 9293 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9294 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9295 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9296 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9297 | perf_tp_register(); |
9298 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9299 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9300 | |
9301 | ret = init_hw_breakpoint(); | |
9302 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9303 | |
9304 | /* do not patch jump label more than once per second */ | |
9305 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9306 | |
9307 | /* | |
9308 | * Build time assertion that we keep the data_head at the intended | |
9309 | * location. IOW, validation we got the __reserved[] size right. | |
9310 | */ | |
9311 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9312 | != 1024); | |
0793a61d | 9313 | } |
abe43400 | 9314 | |
fd979c01 CS |
9315 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9316 | char *page) | |
9317 | { | |
9318 | struct perf_pmu_events_attr *pmu_attr = | |
9319 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9320 | ||
9321 | if (pmu_attr->event_str) | |
9322 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9323 | ||
9324 | return 0; | |
9325 | } | |
9326 | ||
abe43400 PZ |
9327 | static int __init perf_event_sysfs_init(void) |
9328 | { | |
9329 | struct pmu *pmu; | |
9330 | int ret; | |
9331 | ||
9332 | mutex_lock(&pmus_lock); | |
9333 | ||
9334 | ret = bus_register(&pmu_bus); | |
9335 | if (ret) | |
9336 | goto unlock; | |
9337 | ||
9338 | list_for_each_entry(pmu, &pmus, entry) { | |
9339 | if (!pmu->name || pmu->type < 0) | |
9340 | continue; | |
9341 | ||
9342 | ret = pmu_dev_alloc(pmu); | |
9343 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9344 | } | |
9345 | pmu_bus_running = 1; | |
9346 | ret = 0; | |
9347 | ||
9348 | unlock: | |
9349 | mutex_unlock(&pmus_lock); | |
9350 | ||
9351 | return ret; | |
9352 | } | |
9353 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9354 | |
9355 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9356 | static struct cgroup_subsys_state * |
9357 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9358 | { |
9359 | struct perf_cgroup *jc; | |
e5d1367f | 9360 | |
1b15d055 | 9361 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9362 | if (!jc) |
9363 | return ERR_PTR(-ENOMEM); | |
9364 | ||
e5d1367f SE |
9365 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9366 | if (!jc->info) { | |
9367 | kfree(jc); | |
9368 | return ERR_PTR(-ENOMEM); | |
9369 | } | |
9370 | ||
e5d1367f SE |
9371 | return &jc->css; |
9372 | } | |
9373 | ||
eb95419b | 9374 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9375 | { |
eb95419b TH |
9376 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9377 | ||
e5d1367f SE |
9378 | free_percpu(jc->info); |
9379 | kfree(jc); | |
9380 | } | |
9381 | ||
9382 | static int __perf_cgroup_move(void *info) | |
9383 | { | |
9384 | struct task_struct *task = info; | |
ddaaf4e2 | 9385 | rcu_read_lock(); |
e5d1367f | 9386 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9387 | rcu_read_unlock(); |
e5d1367f SE |
9388 | return 0; |
9389 | } | |
9390 | ||
1f7dd3e5 | 9391 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9392 | { |
bb9d97b6 | 9393 | struct task_struct *task; |
1f7dd3e5 | 9394 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9395 | |
1f7dd3e5 | 9396 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9397 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9398 | } |
9399 | ||
073219e9 | 9400 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9401 | .css_alloc = perf_cgroup_css_alloc, |
9402 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9403 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9404 | }; |
9405 | #endif /* CONFIG_CGROUP_PERF */ |