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 | ||
272325c4 PZ |
52 | typedef int (*remote_function_f)(void *); |
53 | ||
fe4b04fa | 54 | struct remote_function_call { |
e7e7ee2e | 55 | struct task_struct *p; |
272325c4 | 56 | remote_function_f func; |
e7e7ee2e IM |
57 | void *info; |
58 | int ret; | |
fe4b04fa PZ |
59 | }; |
60 | ||
61 | static void remote_function(void *data) | |
62 | { | |
63 | struct remote_function_call *tfc = data; | |
64 | struct task_struct *p = tfc->p; | |
65 | ||
66 | if (p) { | |
67 | tfc->ret = -EAGAIN; | |
68 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
69 | return; | |
70 | } | |
71 | ||
72 | tfc->ret = tfc->func(tfc->info); | |
73 | } | |
74 | ||
75 | /** | |
76 | * task_function_call - call a function on the cpu on which a task runs | |
77 | * @p: the task to evaluate | |
78 | * @func: the function to be called | |
79 | * @info: the function call argument | |
80 | * | |
81 | * Calls the function @func when the task is currently running. This might | |
82 | * be on the current CPU, which just calls the function directly | |
83 | * | |
84 | * returns: @func return value, or | |
85 | * -ESRCH - when the process isn't running | |
86 | * -EAGAIN - when the process moved away | |
87 | */ | |
88 | static int | |
272325c4 | 89 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
90 | { |
91 | struct remote_function_call data = { | |
e7e7ee2e IM |
92 | .p = p, |
93 | .func = func, | |
94 | .info = info, | |
95 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
96 | }; |
97 | ||
98 | if (task_curr(p)) | |
99 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
100 | ||
101 | return data.ret; | |
102 | } | |
103 | ||
104 | /** | |
105 | * cpu_function_call - call a function on the cpu | |
106 | * @func: the function to be called | |
107 | * @info: the function call argument | |
108 | * | |
109 | * Calls the function @func on the remote cpu. | |
110 | * | |
111 | * returns: @func return value or -ENXIO when the cpu is offline | |
112 | */ | |
272325c4 | 113 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
114 | { |
115 | struct remote_function_call data = { | |
e7e7ee2e IM |
116 | .p = NULL, |
117 | .func = func, | |
118 | .info = info, | |
119 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
120 | }; |
121 | ||
122 | smp_call_function_single(cpu, remote_function, &data, 1); | |
123 | ||
124 | return data.ret; | |
125 | } | |
126 | ||
fae3fde6 PZ |
127 | static inline struct perf_cpu_context * |
128 | __get_cpu_context(struct perf_event_context *ctx) | |
129 | { | |
130 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
131 | } | |
132 | ||
133 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
134 | struct perf_event_context *ctx) | |
0017960f | 135 | { |
fae3fde6 PZ |
136 | raw_spin_lock(&cpuctx->ctx.lock); |
137 | if (ctx) | |
138 | raw_spin_lock(&ctx->lock); | |
139 | } | |
140 | ||
141 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
142 | struct perf_event_context *ctx) | |
143 | { | |
144 | if (ctx) | |
145 | raw_spin_unlock(&ctx->lock); | |
146 | raw_spin_unlock(&cpuctx->ctx.lock); | |
147 | } | |
148 | ||
63b6da39 PZ |
149 | #define TASK_TOMBSTONE ((void *)-1L) |
150 | ||
151 | static bool is_kernel_event(struct perf_event *event) | |
152 | { | |
f47c02c0 | 153 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
154 | } |
155 | ||
39a43640 PZ |
156 | /* |
157 | * On task ctx scheduling... | |
158 | * | |
159 | * When !ctx->nr_events a task context will not be scheduled. This means | |
160 | * we can disable the scheduler hooks (for performance) without leaving | |
161 | * pending task ctx state. | |
162 | * | |
163 | * This however results in two special cases: | |
164 | * | |
165 | * - removing the last event from a task ctx; this is relatively straight | |
166 | * forward and is done in __perf_remove_from_context. | |
167 | * | |
168 | * - adding the first event to a task ctx; this is tricky because we cannot | |
169 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
170 | * See perf_install_in_context(). | |
171 | * | |
172 | * This is because we need a ctx->lock serialized variable (ctx->is_active) | |
173 | * to reliably determine if a particular task/context is scheduled in. The | |
174 | * task_curr() use in task_function_call() is racy in that a remote context | |
175 | * switch is not a single atomic operation. | |
176 | * | |
177 | * As is, the situation is 'safe' because we set rq->curr before we do the | |
178 | * actual context switch. This means that task_curr() will fail early, but | |
179 | * we'll continue spinning on ctx->is_active until we've passed | |
180 | * perf_event_task_sched_out(). | |
181 | * | |
182 | * Without this ctx->lock serialized variable we could have race where we find | |
183 | * the task (and hence the context) would not be active while in fact they are. | |
184 | * | |
185 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. | |
186 | */ | |
187 | ||
fae3fde6 PZ |
188 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
189 | struct perf_event_context *, void *); | |
190 | ||
191 | struct event_function_struct { | |
192 | struct perf_event *event; | |
193 | event_f func; | |
194 | void *data; | |
195 | }; | |
196 | ||
197 | static int event_function(void *info) | |
198 | { | |
199 | struct event_function_struct *efs = info; | |
200 | struct perf_event *event = efs->event; | |
0017960f | 201 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
202 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
203 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 204 | int ret = 0; |
fae3fde6 PZ |
205 | |
206 | WARN_ON_ONCE(!irqs_disabled()); | |
207 | ||
63b6da39 | 208 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
209 | /* |
210 | * Since we do the IPI call without holding ctx->lock things can have | |
211 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
212 | */ |
213 | if (ctx->task) { | |
63b6da39 PZ |
214 | if (ctx->task != current) { |
215 | ret = -EAGAIN; | |
216 | goto unlock; | |
217 | } | |
fae3fde6 | 218 | |
fae3fde6 PZ |
219 | /* |
220 | * We only use event_function_call() on established contexts, | |
221 | * and event_function() is only ever called when active (or | |
222 | * rather, we'll have bailed in task_function_call() or the | |
223 | * above ctx->task != current test), therefore we must have | |
224 | * ctx->is_active here. | |
225 | */ | |
226 | WARN_ON_ONCE(!ctx->is_active); | |
227 | /* | |
228 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
229 | * match. | |
230 | */ | |
63b6da39 PZ |
231 | WARN_ON_ONCE(task_ctx != ctx); |
232 | } else { | |
233 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 234 | } |
63b6da39 | 235 | |
fae3fde6 | 236 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 237 | unlock: |
fae3fde6 PZ |
238 | perf_ctx_unlock(cpuctx, task_ctx); |
239 | ||
63b6da39 | 240 | return ret; |
fae3fde6 PZ |
241 | } |
242 | ||
243 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
244 | { | |
245 | struct event_function_struct efs = { | |
246 | .event = event, | |
247 | .func = func, | |
248 | .data = data, | |
249 | }; | |
250 | ||
251 | int ret = event_function(&efs); | |
252 | WARN_ON_ONCE(ret); | |
253 | } | |
254 | ||
255 | static void event_function_call(struct perf_event *event, event_f func, void *data) | |
0017960f PZ |
256 | { |
257 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 258 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
259 | struct event_function_struct efs = { |
260 | .event = event, | |
261 | .func = func, | |
262 | .data = data, | |
263 | }; | |
0017960f | 264 | |
c97f4736 PZ |
265 | if (!event->parent) { |
266 | /* | |
267 | * If this is a !child event, we must hold ctx::mutex to | |
268 | * stabilize the the event->ctx relation. See | |
269 | * perf_event_ctx_lock(). | |
270 | */ | |
271 | lockdep_assert_held(&ctx->mutex); | |
272 | } | |
0017960f PZ |
273 | |
274 | if (!task) { | |
fae3fde6 | 275 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
276 | return; |
277 | } | |
278 | ||
279 | again: | |
63b6da39 PZ |
280 | if (task == TASK_TOMBSTONE) |
281 | return; | |
282 | ||
fae3fde6 | 283 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
284 | return; |
285 | ||
286 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
287 | /* |
288 | * Reload the task pointer, it might have been changed by | |
289 | * a concurrent perf_event_context_sched_out(). | |
290 | */ | |
291 | task = ctx->task; | |
292 | if (task != TASK_TOMBSTONE) { | |
293 | if (ctx->is_active) { | |
294 | raw_spin_unlock_irq(&ctx->lock); | |
295 | goto again; | |
296 | } | |
297 | func(event, NULL, ctx, data); | |
0017960f | 298 | } |
0017960f PZ |
299 | raw_spin_unlock_irq(&ctx->lock); |
300 | } | |
301 | ||
e5d1367f SE |
302 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
303 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
304 | PERF_FLAG_PID_CGROUP |\ |
305 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 306 | |
bce38cd5 SE |
307 | /* |
308 | * branch priv levels that need permission checks | |
309 | */ | |
310 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
311 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
312 | PERF_SAMPLE_BRANCH_HV) | |
313 | ||
0b3fcf17 SE |
314 | enum event_type_t { |
315 | EVENT_FLEXIBLE = 0x1, | |
316 | EVENT_PINNED = 0x2, | |
3cbaa590 | 317 | EVENT_TIME = 0x4, |
0b3fcf17 SE |
318 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
319 | }; | |
320 | ||
e5d1367f SE |
321 | /* |
322 | * perf_sched_events : >0 events exist | |
323 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
324 | */ | |
9107c89e PZ |
325 | |
326 | static void perf_sched_delayed(struct work_struct *work); | |
327 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
328 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
329 | static DEFINE_MUTEX(perf_sched_mutex); | |
330 | static atomic_t perf_sched_count; | |
331 | ||
e5d1367f | 332 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 333 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 334 | |
cdd6c482 IM |
335 | static atomic_t nr_mmap_events __read_mostly; |
336 | static atomic_t nr_comm_events __read_mostly; | |
337 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 338 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 339 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 340 | |
108b02cf PZ |
341 | static LIST_HEAD(pmus); |
342 | static DEFINE_MUTEX(pmus_lock); | |
343 | static struct srcu_struct pmus_srcu; | |
344 | ||
0764771d | 345 | /* |
cdd6c482 | 346 | * perf event paranoia level: |
0fbdea19 IM |
347 | * -1 - not paranoid at all |
348 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 349 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 350 | * 2 - disallow kernel profiling for unpriv |
0764771d | 351 | */ |
cdd6c482 | 352 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 353 | |
20443384 FW |
354 | /* Minimum for 512 kiB + 1 user control page */ |
355 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
356 | |
357 | /* | |
cdd6c482 | 358 | * max perf event sample rate |
df58ab24 | 359 | */ |
14c63f17 DH |
360 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
361 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
362 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
363 | ||
364 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
365 | ||
366 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
367 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
368 | ||
d9494cb4 PZ |
369 | static int perf_sample_allowed_ns __read_mostly = |
370 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 371 | |
18ab2cd3 | 372 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
373 | { |
374 | u64 tmp = perf_sample_period_ns; | |
375 | ||
376 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 377 | do_div(tmp, 100); |
d9494cb4 | 378 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 379 | } |
163ec435 | 380 | |
9e630205 SE |
381 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
382 | ||
163ec435 PZ |
383 | int perf_proc_update_handler(struct ctl_table *table, int write, |
384 | void __user *buffer, size_t *lenp, | |
385 | loff_t *ppos) | |
386 | { | |
723478c8 | 387 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
388 | |
389 | if (ret || !write) | |
390 | return ret; | |
391 | ||
392 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
393 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
394 | update_perf_cpu_limits(); | |
395 | ||
396 | return 0; | |
397 | } | |
398 | ||
399 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
400 | ||
401 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
402 | void __user *buffer, size_t *lenp, | |
403 | loff_t *ppos) | |
404 | { | |
405 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
406 | ||
407 | if (ret || !write) | |
408 | return ret; | |
409 | ||
410 | update_perf_cpu_limits(); | |
163ec435 PZ |
411 | |
412 | return 0; | |
413 | } | |
1ccd1549 | 414 | |
14c63f17 DH |
415 | /* |
416 | * perf samples are done in some very critical code paths (NMIs). | |
417 | * If they take too much CPU time, the system can lock up and not | |
418 | * get any real work done. This will drop the sample rate when | |
419 | * we detect that events are taking too long. | |
420 | */ | |
421 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 422 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 423 | |
6a02ad66 | 424 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 425 | { |
6a02ad66 | 426 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 427 | u64 avg_local_sample_len; |
e5302920 | 428 | u64 local_samples_len; |
6a02ad66 | 429 | |
4a32fea9 | 430 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
431 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
432 | ||
433 | printk_ratelimited(KERN_WARNING | |
434 | "perf interrupt took too long (%lld > %lld), lowering " | |
435 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 436 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
437 | sysctl_perf_event_sample_rate); |
438 | } | |
439 | ||
440 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
441 | ||
442 | void perf_sample_event_took(u64 sample_len_ns) | |
443 | { | |
d9494cb4 | 444 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
445 | u64 avg_local_sample_len; |
446 | u64 local_samples_len; | |
14c63f17 | 447 | |
d9494cb4 | 448 | if (allowed_ns == 0) |
14c63f17 DH |
449 | return; |
450 | ||
451 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 452 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
453 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
454 | local_samples_len += sample_len_ns; | |
4a32fea9 | 455 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
456 | |
457 | /* | |
458 | * note: this will be biased artifically low until we have | |
459 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
460 | * from having to maintain a count. | |
461 | */ | |
462 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
463 | ||
d9494cb4 | 464 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
465 | return; |
466 | ||
467 | if (max_samples_per_tick <= 1) | |
468 | return; | |
469 | ||
470 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
471 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
472 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
473 | ||
14c63f17 | 474 | update_perf_cpu_limits(); |
6a02ad66 | 475 | |
cd578abb PZ |
476 | if (!irq_work_queue(&perf_duration_work)) { |
477 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
478 | "kernel.perf_event_max_sample_rate to %d\n", | |
479 | avg_local_sample_len, allowed_ns >> 1, | |
480 | sysctl_perf_event_sample_rate); | |
481 | } | |
14c63f17 DH |
482 | } |
483 | ||
cdd6c482 | 484 | static atomic64_t perf_event_id; |
a96bbc16 | 485 | |
0b3fcf17 SE |
486 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
487 | enum event_type_t event_type); | |
488 | ||
489 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
490 | enum event_type_t event_type, |
491 | struct task_struct *task); | |
492 | ||
493 | static void update_context_time(struct perf_event_context *ctx); | |
494 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 495 | |
cdd6c482 | 496 | void __weak perf_event_print_debug(void) { } |
0793a61d | 497 | |
84c79910 | 498 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 499 | { |
84c79910 | 500 | return "pmu"; |
0793a61d TG |
501 | } |
502 | ||
0b3fcf17 SE |
503 | static inline u64 perf_clock(void) |
504 | { | |
505 | return local_clock(); | |
506 | } | |
507 | ||
34f43927 PZ |
508 | static inline u64 perf_event_clock(struct perf_event *event) |
509 | { | |
510 | return event->clock(); | |
511 | } | |
512 | ||
e5d1367f SE |
513 | #ifdef CONFIG_CGROUP_PERF |
514 | ||
e5d1367f SE |
515 | static inline bool |
516 | perf_cgroup_match(struct perf_event *event) | |
517 | { | |
518 | struct perf_event_context *ctx = event->ctx; | |
519 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
520 | ||
ef824fa1 TH |
521 | /* @event doesn't care about cgroup */ |
522 | if (!event->cgrp) | |
523 | return true; | |
524 | ||
525 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
526 | if (!cpuctx->cgrp) | |
527 | return false; | |
528 | ||
529 | /* | |
530 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
531 | * also enabled for all its descendant cgroups. If @cpuctx's | |
532 | * cgroup is a descendant of @event's (the test covers identity | |
533 | * case), it's a match. | |
534 | */ | |
535 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
536 | event->cgrp->css.cgroup); | |
e5d1367f SE |
537 | } |
538 | ||
e5d1367f SE |
539 | static inline void perf_detach_cgroup(struct perf_event *event) |
540 | { | |
4e2ba650 | 541 | css_put(&event->cgrp->css); |
e5d1367f SE |
542 | event->cgrp = NULL; |
543 | } | |
544 | ||
545 | static inline int is_cgroup_event(struct perf_event *event) | |
546 | { | |
547 | return event->cgrp != NULL; | |
548 | } | |
549 | ||
550 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
551 | { | |
552 | struct perf_cgroup_info *t; | |
553 | ||
554 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
555 | return t->time; | |
556 | } | |
557 | ||
558 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
559 | { | |
560 | struct perf_cgroup_info *info; | |
561 | u64 now; | |
562 | ||
563 | now = perf_clock(); | |
564 | ||
565 | info = this_cpu_ptr(cgrp->info); | |
566 | ||
567 | info->time += now - info->timestamp; | |
568 | info->timestamp = now; | |
569 | } | |
570 | ||
571 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
572 | { | |
573 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
574 | if (cgrp_out) | |
575 | __update_cgrp_time(cgrp_out); | |
576 | } | |
577 | ||
578 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
579 | { | |
3f7cce3c SE |
580 | struct perf_cgroup *cgrp; |
581 | ||
e5d1367f | 582 | /* |
3f7cce3c SE |
583 | * ensure we access cgroup data only when needed and |
584 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 585 | */ |
3f7cce3c | 586 | if (!is_cgroup_event(event)) |
e5d1367f SE |
587 | return; |
588 | ||
614e4c4e | 589 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
590 | /* |
591 | * Do not update time when cgroup is not active | |
592 | */ | |
593 | if (cgrp == event->cgrp) | |
594 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
595 | } |
596 | ||
597 | static inline void | |
3f7cce3c SE |
598 | perf_cgroup_set_timestamp(struct task_struct *task, |
599 | struct perf_event_context *ctx) | |
e5d1367f SE |
600 | { |
601 | struct perf_cgroup *cgrp; | |
602 | struct perf_cgroup_info *info; | |
603 | ||
3f7cce3c SE |
604 | /* |
605 | * ctx->lock held by caller | |
606 | * ensure we do not access cgroup data | |
607 | * unless we have the cgroup pinned (css_get) | |
608 | */ | |
609 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
610 | return; |
611 | ||
614e4c4e | 612 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 613 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 614 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
615 | } |
616 | ||
617 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
618 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
619 | ||
620 | /* | |
621 | * reschedule events based on the cgroup constraint of task. | |
622 | * | |
623 | * mode SWOUT : schedule out everything | |
624 | * mode SWIN : schedule in based on cgroup for next | |
625 | */ | |
18ab2cd3 | 626 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
627 | { |
628 | struct perf_cpu_context *cpuctx; | |
629 | struct pmu *pmu; | |
630 | unsigned long flags; | |
631 | ||
632 | /* | |
633 | * disable interrupts to avoid geting nr_cgroup | |
634 | * changes via __perf_event_disable(). Also | |
635 | * avoids preemption. | |
636 | */ | |
637 | local_irq_save(flags); | |
638 | ||
639 | /* | |
640 | * we reschedule only in the presence of cgroup | |
641 | * constrained events. | |
642 | */ | |
e5d1367f SE |
643 | |
644 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 645 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
646 | if (cpuctx->unique_pmu != pmu) |
647 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 648 | |
e5d1367f SE |
649 | /* |
650 | * perf_cgroup_events says at least one | |
651 | * context on this CPU has cgroup events. | |
652 | * | |
653 | * ctx->nr_cgroups reports the number of cgroup | |
654 | * events for a context. | |
655 | */ | |
656 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
657 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
658 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
659 | |
660 | if (mode & PERF_CGROUP_SWOUT) { | |
661 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
662 | /* | |
663 | * must not be done before ctxswout due | |
664 | * to event_filter_match() in event_sched_out() | |
665 | */ | |
666 | cpuctx->cgrp = NULL; | |
667 | } | |
668 | ||
669 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 670 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
671 | /* |
672 | * set cgrp before ctxsw in to allow | |
673 | * event_filter_match() to not have to pass | |
674 | * task around | |
614e4c4e SE |
675 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
676 | * because cgorup events are only per-cpu | |
e5d1367f | 677 | */ |
614e4c4e | 678 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
679 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
680 | } | |
facc4307 PZ |
681 | perf_pmu_enable(cpuctx->ctx.pmu); |
682 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 683 | } |
e5d1367f SE |
684 | } |
685 | ||
e5d1367f SE |
686 | local_irq_restore(flags); |
687 | } | |
688 | ||
a8d757ef SE |
689 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
690 | struct task_struct *next) | |
e5d1367f | 691 | { |
a8d757ef SE |
692 | struct perf_cgroup *cgrp1; |
693 | struct perf_cgroup *cgrp2 = NULL; | |
694 | ||
ddaaf4e2 | 695 | rcu_read_lock(); |
a8d757ef SE |
696 | /* |
697 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
698 | * we do not need to pass the ctx here because we know |
699 | * we are holding the rcu lock | |
a8d757ef | 700 | */ |
614e4c4e | 701 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 702 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
703 | |
704 | /* | |
705 | * only schedule out current cgroup events if we know | |
706 | * that we are switching to a different cgroup. Otherwise, | |
707 | * do no touch the cgroup events. | |
708 | */ | |
709 | if (cgrp1 != cgrp2) | |
710 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
711 | |
712 | rcu_read_unlock(); | |
e5d1367f SE |
713 | } |
714 | ||
a8d757ef SE |
715 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
716 | struct task_struct *task) | |
e5d1367f | 717 | { |
a8d757ef SE |
718 | struct perf_cgroup *cgrp1; |
719 | struct perf_cgroup *cgrp2 = NULL; | |
720 | ||
ddaaf4e2 | 721 | rcu_read_lock(); |
a8d757ef SE |
722 | /* |
723 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
724 | * we do not need to pass the ctx here because we know |
725 | * we are holding the rcu lock | |
a8d757ef | 726 | */ |
614e4c4e | 727 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 728 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
729 | |
730 | /* | |
731 | * only need to schedule in cgroup events if we are changing | |
732 | * cgroup during ctxsw. Cgroup events were not scheduled | |
733 | * out of ctxsw out if that was not the case. | |
734 | */ | |
735 | if (cgrp1 != cgrp2) | |
736 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
737 | |
738 | rcu_read_unlock(); | |
e5d1367f SE |
739 | } |
740 | ||
741 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
742 | struct perf_event_attr *attr, | |
743 | struct perf_event *group_leader) | |
744 | { | |
745 | struct perf_cgroup *cgrp; | |
746 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
747 | struct fd f = fdget(fd); |
748 | int ret = 0; | |
e5d1367f | 749 | |
2903ff01 | 750 | if (!f.file) |
e5d1367f SE |
751 | return -EBADF; |
752 | ||
b583043e | 753 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 754 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
755 | if (IS_ERR(css)) { |
756 | ret = PTR_ERR(css); | |
757 | goto out; | |
758 | } | |
e5d1367f SE |
759 | |
760 | cgrp = container_of(css, struct perf_cgroup, css); | |
761 | event->cgrp = cgrp; | |
762 | ||
763 | /* | |
764 | * all events in a group must monitor | |
765 | * the same cgroup because a task belongs | |
766 | * to only one perf cgroup at a time | |
767 | */ | |
768 | if (group_leader && group_leader->cgrp != cgrp) { | |
769 | perf_detach_cgroup(event); | |
770 | ret = -EINVAL; | |
e5d1367f | 771 | } |
3db272c0 | 772 | out: |
2903ff01 | 773 | fdput(f); |
e5d1367f SE |
774 | return ret; |
775 | } | |
776 | ||
777 | static inline void | |
778 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
779 | { | |
780 | struct perf_cgroup_info *t; | |
781 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
782 | event->shadow_ctx_time = now - t->timestamp; | |
783 | } | |
784 | ||
785 | static inline void | |
786 | perf_cgroup_defer_enabled(struct perf_event *event) | |
787 | { | |
788 | /* | |
789 | * when the current task's perf cgroup does not match | |
790 | * the event's, we need to remember to call the | |
791 | * perf_mark_enable() function the first time a task with | |
792 | * a matching perf cgroup is scheduled in. | |
793 | */ | |
794 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
795 | event->cgrp_defer_enabled = 1; | |
796 | } | |
797 | ||
798 | static inline void | |
799 | perf_cgroup_mark_enabled(struct perf_event *event, | |
800 | struct perf_event_context *ctx) | |
801 | { | |
802 | struct perf_event *sub; | |
803 | u64 tstamp = perf_event_time(event); | |
804 | ||
805 | if (!event->cgrp_defer_enabled) | |
806 | return; | |
807 | ||
808 | event->cgrp_defer_enabled = 0; | |
809 | ||
810 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
811 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
812 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
813 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
814 | sub->cgrp_defer_enabled = 0; | |
815 | } | |
816 | } | |
817 | } | |
818 | #else /* !CONFIG_CGROUP_PERF */ | |
819 | ||
820 | static inline bool | |
821 | perf_cgroup_match(struct perf_event *event) | |
822 | { | |
823 | return true; | |
824 | } | |
825 | ||
826 | static inline void perf_detach_cgroup(struct perf_event *event) | |
827 | {} | |
828 | ||
829 | static inline int is_cgroup_event(struct perf_event *event) | |
830 | { | |
831 | return 0; | |
832 | } | |
833 | ||
834 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
835 | { | |
836 | return 0; | |
837 | } | |
838 | ||
839 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
840 | { | |
841 | } | |
842 | ||
843 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
844 | { | |
845 | } | |
846 | ||
a8d757ef SE |
847 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
848 | struct task_struct *next) | |
e5d1367f SE |
849 | { |
850 | } | |
851 | ||
a8d757ef SE |
852 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
853 | struct task_struct *task) | |
e5d1367f SE |
854 | { |
855 | } | |
856 | ||
857 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
858 | struct perf_event_attr *attr, | |
859 | struct perf_event *group_leader) | |
860 | { | |
861 | return -EINVAL; | |
862 | } | |
863 | ||
864 | static inline void | |
3f7cce3c SE |
865 | perf_cgroup_set_timestamp(struct task_struct *task, |
866 | struct perf_event_context *ctx) | |
e5d1367f SE |
867 | { |
868 | } | |
869 | ||
870 | void | |
871 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
872 | { | |
873 | } | |
874 | ||
875 | static inline void | |
876 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
877 | { | |
878 | } | |
879 | ||
880 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
881 | { | |
882 | return 0; | |
883 | } | |
884 | ||
885 | static inline void | |
886 | perf_cgroup_defer_enabled(struct perf_event *event) | |
887 | { | |
888 | } | |
889 | ||
890 | static inline void | |
891 | perf_cgroup_mark_enabled(struct perf_event *event, | |
892 | struct perf_event_context *ctx) | |
893 | { | |
894 | } | |
895 | #endif | |
896 | ||
9e630205 SE |
897 | /* |
898 | * set default to be dependent on timer tick just | |
899 | * like original code | |
900 | */ | |
901 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
902 | /* | |
903 | * function must be called with interrupts disbled | |
904 | */ | |
272325c4 | 905 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
906 | { |
907 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
908 | int rotations = 0; |
909 | ||
910 | WARN_ON(!irqs_disabled()); | |
911 | ||
912 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
913 | rotations = perf_rotate_context(cpuctx); |
914 | ||
4cfafd30 PZ |
915 | raw_spin_lock(&cpuctx->hrtimer_lock); |
916 | if (rotations) | |
9e630205 | 917 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
918 | else |
919 | cpuctx->hrtimer_active = 0; | |
920 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 921 | |
4cfafd30 | 922 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
923 | } |
924 | ||
272325c4 | 925 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 926 | { |
272325c4 | 927 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 928 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 929 | u64 interval; |
9e630205 SE |
930 | |
931 | /* no multiplexing needed for SW PMU */ | |
932 | if (pmu->task_ctx_nr == perf_sw_context) | |
933 | return; | |
934 | ||
62b85639 SE |
935 | /* |
936 | * check default is sane, if not set then force to | |
937 | * default interval (1/tick) | |
938 | */ | |
272325c4 PZ |
939 | interval = pmu->hrtimer_interval_ms; |
940 | if (interval < 1) | |
941 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 942 | |
272325c4 | 943 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 944 | |
4cfafd30 PZ |
945 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
946 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 947 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
948 | } |
949 | ||
272325c4 | 950 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 951 | { |
272325c4 | 952 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 953 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 954 | unsigned long flags; |
9e630205 SE |
955 | |
956 | /* not for SW PMU */ | |
957 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 958 | return 0; |
9e630205 | 959 | |
4cfafd30 PZ |
960 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
961 | if (!cpuctx->hrtimer_active) { | |
962 | cpuctx->hrtimer_active = 1; | |
963 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
964 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
965 | } | |
966 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 967 | |
272325c4 | 968 | return 0; |
9e630205 SE |
969 | } |
970 | ||
33696fc0 | 971 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 972 | { |
33696fc0 PZ |
973 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
974 | if (!(*count)++) | |
975 | pmu->pmu_disable(pmu); | |
9e35ad38 | 976 | } |
9e35ad38 | 977 | |
33696fc0 | 978 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 979 | { |
33696fc0 PZ |
980 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
981 | if (!--(*count)) | |
982 | pmu->pmu_enable(pmu); | |
9e35ad38 | 983 | } |
9e35ad38 | 984 | |
2fde4f94 | 985 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
986 | |
987 | /* | |
2fde4f94 MR |
988 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
989 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
990 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
991 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 992 | */ |
2fde4f94 | 993 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 994 | { |
2fde4f94 | 995 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 996 | |
e9d2b064 | 997 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 998 | |
2fde4f94 MR |
999 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1000 | ||
1001 | list_add(&ctx->active_ctx_list, head); | |
1002 | } | |
1003 | ||
1004 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1005 | { | |
1006 | WARN_ON(!irqs_disabled()); | |
1007 | ||
1008 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1009 | ||
1010 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1011 | } |
9e35ad38 | 1012 | |
cdd6c482 | 1013 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1014 | { |
e5289d4a | 1015 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1016 | } |
1017 | ||
4af57ef2 YZ |
1018 | static void free_ctx(struct rcu_head *head) |
1019 | { | |
1020 | struct perf_event_context *ctx; | |
1021 | ||
1022 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1023 | kfree(ctx->task_ctx_data); | |
1024 | kfree(ctx); | |
1025 | } | |
1026 | ||
cdd6c482 | 1027 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1028 | { |
564c2b21 PM |
1029 | if (atomic_dec_and_test(&ctx->refcount)) { |
1030 | if (ctx->parent_ctx) | |
1031 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1032 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1033 | put_task_struct(ctx->task); |
4af57ef2 | 1034 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1035 | } |
a63eaf34 PM |
1036 | } |
1037 | ||
f63a8daa PZ |
1038 | /* |
1039 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1040 | * perf_pmu_migrate_context() we need some magic. | |
1041 | * | |
1042 | * Those places that change perf_event::ctx will hold both | |
1043 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1044 | * | |
8b10c5e2 PZ |
1045 | * Lock ordering is by mutex address. There are two other sites where |
1046 | * perf_event_context::mutex nests and those are: | |
1047 | * | |
1048 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1049 | * perf_event_exit_event() |
1050 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1051 | * |
1052 | * - perf_event_init_context() [ parent, 0 ] | |
1053 | * inherit_task_group() | |
1054 | * inherit_group() | |
1055 | * inherit_event() | |
1056 | * perf_event_alloc() | |
1057 | * perf_init_event() | |
1058 | * perf_try_init_event() [ child , 1 ] | |
1059 | * | |
1060 | * While it appears there is an obvious deadlock here -- the parent and child | |
1061 | * nesting levels are inverted between the two. This is in fact safe because | |
1062 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1063 | * spawning task cannot (yet) exit. | |
1064 | * | |
1065 | * But remember that that these are parent<->child context relations, and | |
1066 | * migration does not affect children, therefore these two orderings should not | |
1067 | * interact. | |
f63a8daa PZ |
1068 | * |
1069 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1070 | * because the sys_perf_event_open() case will install a new event and break | |
1071 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1072 | * concerned with cpuctx and that doesn't have children. | |
1073 | * | |
1074 | * The places that change perf_event::ctx will issue: | |
1075 | * | |
1076 | * perf_remove_from_context(); | |
1077 | * synchronize_rcu(); | |
1078 | * perf_install_in_context(); | |
1079 | * | |
1080 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1081 | * quiesce the event, after which we can install it in the new location. This | |
1082 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1083 | * while in transit. Therefore all such accessors should also acquire | |
1084 | * perf_event_context::mutex to serialize against this. | |
1085 | * | |
1086 | * However; because event->ctx can change while we're waiting to acquire | |
1087 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1088 | * function. | |
1089 | * | |
1090 | * Lock order: | |
1091 | * task_struct::perf_event_mutex | |
1092 | * perf_event_context::mutex | |
f63a8daa | 1093 | * perf_event::child_mutex; |
07c4a776 | 1094 | * perf_event_context::lock |
f63a8daa PZ |
1095 | * perf_event::mmap_mutex |
1096 | * mmap_sem | |
1097 | */ | |
a83fe28e PZ |
1098 | static struct perf_event_context * |
1099 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1100 | { |
1101 | struct perf_event_context *ctx; | |
1102 | ||
1103 | again: | |
1104 | rcu_read_lock(); | |
1105 | ctx = ACCESS_ONCE(event->ctx); | |
1106 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1107 | rcu_read_unlock(); | |
1108 | goto again; | |
1109 | } | |
1110 | rcu_read_unlock(); | |
1111 | ||
a83fe28e | 1112 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1113 | if (event->ctx != ctx) { |
1114 | mutex_unlock(&ctx->mutex); | |
1115 | put_ctx(ctx); | |
1116 | goto again; | |
1117 | } | |
1118 | ||
1119 | return ctx; | |
1120 | } | |
1121 | ||
a83fe28e PZ |
1122 | static inline struct perf_event_context * |
1123 | perf_event_ctx_lock(struct perf_event *event) | |
1124 | { | |
1125 | return perf_event_ctx_lock_nested(event, 0); | |
1126 | } | |
1127 | ||
f63a8daa PZ |
1128 | static void perf_event_ctx_unlock(struct perf_event *event, |
1129 | struct perf_event_context *ctx) | |
1130 | { | |
1131 | mutex_unlock(&ctx->mutex); | |
1132 | put_ctx(ctx); | |
1133 | } | |
1134 | ||
211de6eb PZ |
1135 | /* |
1136 | * This must be done under the ctx->lock, such as to serialize against | |
1137 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1138 | * calling scheduler related locks and ctx->lock nests inside those. | |
1139 | */ | |
1140 | static __must_check struct perf_event_context * | |
1141 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1142 | { |
211de6eb PZ |
1143 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1144 | ||
1145 | lockdep_assert_held(&ctx->lock); | |
1146 | ||
1147 | if (parent_ctx) | |
71a851b4 | 1148 | ctx->parent_ctx = NULL; |
5a3126d4 | 1149 | ctx->generation++; |
211de6eb PZ |
1150 | |
1151 | return parent_ctx; | |
71a851b4 PZ |
1152 | } |
1153 | ||
6844c09d ACM |
1154 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1155 | { | |
1156 | /* | |
1157 | * only top level events have the pid namespace they were created in | |
1158 | */ | |
1159 | if (event->parent) | |
1160 | event = event->parent; | |
1161 | ||
1162 | return task_tgid_nr_ns(p, event->ns); | |
1163 | } | |
1164 | ||
1165 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1166 | { | |
1167 | /* | |
1168 | * only top level events have the pid namespace they were created in | |
1169 | */ | |
1170 | if (event->parent) | |
1171 | event = event->parent; | |
1172 | ||
1173 | return task_pid_nr_ns(p, event->ns); | |
1174 | } | |
1175 | ||
7f453c24 | 1176 | /* |
cdd6c482 | 1177 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1178 | * to userspace. |
1179 | */ | |
cdd6c482 | 1180 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1181 | { |
cdd6c482 | 1182 | u64 id = event->id; |
7f453c24 | 1183 | |
cdd6c482 IM |
1184 | if (event->parent) |
1185 | id = event->parent->id; | |
7f453c24 PZ |
1186 | |
1187 | return id; | |
1188 | } | |
1189 | ||
25346b93 | 1190 | /* |
cdd6c482 | 1191 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1192 | * |
25346b93 PM |
1193 | * This has to cope with with the fact that until it is locked, |
1194 | * the context could get moved to another task. | |
1195 | */ | |
cdd6c482 | 1196 | static struct perf_event_context * |
8dc85d54 | 1197 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1198 | { |
cdd6c482 | 1199 | struct perf_event_context *ctx; |
25346b93 | 1200 | |
9ed6060d | 1201 | retry: |
058ebd0e PZ |
1202 | /* |
1203 | * One of the few rules of preemptible RCU is that one cannot do | |
1204 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1205 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1206 | * rcu_read_unlock_special(). |
1207 | * | |
1208 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1209 | * side critical section has interrupts disabled. |
058ebd0e | 1210 | */ |
2fd59077 | 1211 | local_irq_save(*flags); |
058ebd0e | 1212 | rcu_read_lock(); |
8dc85d54 | 1213 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1214 | if (ctx) { |
1215 | /* | |
1216 | * If this context is a clone of another, it might | |
1217 | * get swapped for another underneath us by | |
cdd6c482 | 1218 | * perf_event_task_sched_out, though the |
25346b93 PM |
1219 | * rcu_read_lock() protects us from any context |
1220 | * getting freed. Lock the context and check if it | |
1221 | * got swapped before we could get the lock, and retry | |
1222 | * if so. If we locked the right context, then it | |
1223 | * can't get swapped on us any more. | |
1224 | */ | |
2fd59077 | 1225 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1226 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1227 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1228 | rcu_read_unlock(); |
2fd59077 | 1229 | local_irq_restore(*flags); |
25346b93 PM |
1230 | goto retry; |
1231 | } | |
b49a9e7e | 1232 | |
63b6da39 PZ |
1233 | if (ctx->task == TASK_TOMBSTONE || |
1234 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1235 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1236 | ctx = NULL; |
828b6f0e PZ |
1237 | } else { |
1238 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1239 | } |
25346b93 PM |
1240 | } |
1241 | rcu_read_unlock(); | |
2fd59077 PM |
1242 | if (!ctx) |
1243 | local_irq_restore(*flags); | |
25346b93 PM |
1244 | return ctx; |
1245 | } | |
1246 | ||
1247 | /* | |
1248 | * Get the context for a task and increment its pin_count so it | |
1249 | * can't get swapped to another task. This also increments its | |
1250 | * reference count so that the context can't get freed. | |
1251 | */ | |
8dc85d54 PZ |
1252 | static struct perf_event_context * |
1253 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1254 | { |
cdd6c482 | 1255 | struct perf_event_context *ctx; |
25346b93 PM |
1256 | unsigned long flags; |
1257 | ||
8dc85d54 | 1258 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1259 | if (ctx) { |
1260 | ++ctx->pin_count; | |
e625cce1 | 1261 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1262 | } |
1263 | return ctx; | |
1264 | } | |
1265 | ||
cdd6c482 | 1266 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1267 | { |
1268 | unsigned long flags; | |
1269 | ||
e625cce1 | 1270 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1271 | --ctx->pin_count; |
e625cce1 | 1272 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1273 | } |
1274 | ||
f67218c3 PZ |
1275 | /* |
1276 | * Update the record of the current time in a context. | |
1277 | */ | |
1278 | static void update_context_time(struct perf_event_context *ctx) | |
1279 | { | |
1280 | u64 now = perf_clock(); | |
1281 | ||
1282 | ctx->time += now - ctx->timestamp; | |
1283 | ctx->timestamp = now; | |
1284 | } | |
1285 | ||
4158755d SE |
1286 | static u64 perf_event_time(struct perf_event *event) |
1287 | { | |
1288 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1289 | |
1290 | if (is_cgroup_event(event)) | |
1291 | return perf_cgroup_event_time(event); | |
1292 | ||
4158755d SE |
1293 | return ctx ? ctx->time : 0; |
1294 | } | |
1295 | ||
f67218c3 PZ |
1296 | /* |
1297 | * Update the total_time_enabled and total_time_running fields for a event. | |
1298 | */ | |
1299 | static void update_event_times(struct perf_event *event) | |
1300 | { | |
1301 | struct perf_event_context *ctx = event->ctx; | |
1302 | u64 run_end; | |
1303 | ||
3cbaa590 PZ |
1304 | lockdep_assert_held(&ctx->lock); |
1305 | ||
f67218c3 PZ |
1306 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
1307 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1308 | return; | |
3cbaa590 | 1309 | |
e5d1367f SE |
1310 | /* |
1311 | * in cgroup mode, time_enabled represents | |
1312 | * the time the event was enabled AND active | |
1313 | * tasks were in the monitored cgroup. This is | |
1314 | * independent of the activity of the context as | |
1315 | * there may be a mix of cgroup and non-cgroup events. | |
1316 | * | |
1317 | * That is why we treat cgroup events differently | |
1318 | * here. | |
1319 | */ | |
1320 | if (is_cgroup_event(event)) | |
46cd6a7f | 1321 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1322 | else if (ctx->is_active) |
1323 | run_end = ctx->time; | |
acd1d7c1 PZ |
1324 | else |
1325 | run_end = event->tstamp_stopped; | |
1326 | ||
1327 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1328 | |
1329 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1330 | run_end = event->tstamp_stopped; | |
1331 | else | |
4158755d | 1332 | run_end = perf_event_time(event); |
f67218c3 PZ |
1333 | |
1334 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1335 | |
f67218c3 PZ |
1336 | } |
1337 | ||
96c21a46 PZ |
1338 | /* |
1339 | * Update total_time_enabled and total_time_running for all events in a group. | |
1340 | */ | |
1341 | static void update_group_times(struct perf_event *leader) | |
1342 | { | |
1343 | struct perf_event *event; | |
1344 | ||
1345 | update_event_times(leader); | |
1346 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1347 | update_event_times(event); | |
1348 | } | |
1349 | ||
889ff015 FW |
1350 | static struct list_head * |
1351 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1352 | { | |
1353 | if (event->attr.pinned) | |
1354 | return &ctx->pinned_groups; | |
1355 | else | |
1356 | return &ctx->flexible_groups; | |
1357 | } | |
1358 | ||
fccc714b | 1359 | /* |
cdd6c482 | 1360 | * Add a event from the lists for its context. |
fccc714b PZ |
1361 | * Must be called with ctx->mutex and ctx->lock held. |
1362 | */ | |
04289bb9 | 1363 | static void |
cdd6c482 | 1364 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1365 | { |
c994d613 PZ |
1366 | lockdep_assert_held(&ctx->lock); |
1367 | ||
8a49542c PZ |
1368 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1369 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1370 | |
1371 | /* | |
8a49542c PZ |
1372 | * If we're a stand alone event or group leader, we go to the context |
1373 | * list, group events are kept attached to the group so that | |
1374 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1375 | */ |
8a49542c | 1376 | if (event->group_leader == event) { |
889ff015 FW |
1377 | struct list_head *list; |
1378 | ||
d6f962b5 FW |
1379 | if (is_software_event(event)) |
1380 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1381 | ||
889ff015 FW |
1382 | list = ctx_group_list(event, ctx); |
1383 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1384 | } |
592903cd | 1385 | |
08309379 | 1386 | if (is_cgroup_event(event)) |
e5d1367f | 1387 | ctx->nr_cgroups++; |
e5d1367f | 1388 | |
cdd6c482 IM |
1389 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1390 | ctx->nr_events++; | |
1391 | if (event->attr.inherit_stat) | |
bfbd3381 | 1392 | ctx->nr_stat++; |
5a3126d4 PZ |
1393 | |
1394 | ctx->generation++; | |
04289bb9 IM |
1395 | } |
1396 | ||
0231bb53 JO |
1397 | /* |
1398 | * Initialize event state based on the perf_event_attr::disabled. | |
1399 | */ | |
1400 | static inline void perf_event__state_init(struct perf_event *event) | |
1401 | { | |
1402 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1403 | PERF_EVENT_STATE_INACTIVE; | |
1404 | } | |
1405 | ||
a723968c | 1406 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1407 | { |
1408 | int entry = sizeof(u64); /* value */ | |
1409 | int size = 0; | |
1410 | int nr = 1; | |
1411 | ||
1412 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1413 | size += sizeof(u64); | |
1414 | ||
1415 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1416 | size += sizeof(u64); | |
1417 | ||
1418 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1419 | entry += sizeof(u64); | |
1420 | ||
1421 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1422 | nr += nr_siblings; |
c320c7b7 ACM |
1423 | size += sizeof(u64); |
1424 | } | |
1425 | ||
1426 | size += entry * nr; | |
1427 | event->read_size = size; | |
1428 | } | |
1429 | ||
a723968c | 1430 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1431 | { |
1432 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1433 | u16 size = 0; |
1434 | ||
c320c7b7 ACM |
1435 | if (sample_type & PERF_SAMPLE_IP) |
1436 | size += sizeof(data->ip); | |
1437 | ||
6844c09d ACM |
1438 | if (sample_type & PERF_SAMPLE_ADDR) |
1439 | size += sizeof(data->addr); | |
1440 | ||
1441 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1442 | size += sizeof(data->period); | |
1443 | ||
c3feedf2 AK |
1444 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1445 | size += sizeof(data->weight); | |
1446 | ||
6844c09d ACM |
1447 | if (sample_type & PERF_SAMPLE_READ) |
1448 | size += event->read_size; | |
1449 | ||
d6be9ad6 SE |
1450 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1451 | size += sizeof(data->data_src.val); | |
1452 | ||
fdfbbd07 AK |
1453 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1454 | size += sizeof(data->txn); | |
1455 | ||
6844c09d ACM |
1456 | event->header_size = size; |
1457 | } | |
1458 | ||
a723968c PZ |
1459 | /* |
1460 | * Called at perf_event creation and when events are attached/detached from a | |
1461 | * group. | |
1462 | */ | |
1463 | static void perf_event__header_size(struct perf_event *event) | |
1464 | { | |
1465 | __perf_event_read_size(event, | |
1466 | event->group_leader->nr_siblings); | |
1467 | __perf_event_header_size(event, event->attr.sample_type); | |
1468 | } | |
1469 | ||
6844c09d ACM |
1470 | static void perf_event__id_header_size(struct perf_event *event) |
1471 | { | |
1472 | struct perf_sample_data *data; | |
1473 | u64 sample_type = event->attr.sample_type; | |
1474 | u16 size = 0; | |
1475 | ||
c320c7b7 ACM |
1476 | if (sample_type & PERF_SAMPLE_TID) |
1477 | size += sizeof(data->tid_entry); | |
1478 | ||
1479 | if (sample_type & PERF_SAMPLE_TIME) | |
1480 | size += sizeof(data->time); | |
1481 | ||
ff3d527c AH |
1482 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1483 | size += sizeof(data->id); | |
1484 | ||
c320c7b7 ACM |
1485 | if (sample_type & PERF_SAMPLE_ID) |
1486 | size += sizeof(data->id); | |
1487 | ||
1488 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1489 | size += sizeof(data->stream_id); | |
1490 | ||
1491 | if (sample_type & PERF_SAMPLE_CPU) | |
1492 | size += sizeof(data->cpu_entry); | |
1493 | ||
6844c09d | 1494 | event->id_header_size = size; |
c320c7b7 ACM |
1495 | } |
1496 | ||
a723968c PZ |
1497 | static bool perf_event_validate_size(struct perf_event *event) |
1498 | { | |
1499 | /* | |
1500 | * The values computed here will be over-written when we actually | |
1501 | * attach the event. | |
1502 | */ | |
1503 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1504 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1505 | perf_event__id_header_size(event); | |
1506 | ||
1507 | /* | |
1508 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1509 | * Conservative limit to allow for callchains and other variable fields. | |
1510 | */ | |
1511 | if (event->read_size + event->header_size + | |
1512 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1513 | return false; | |
1514 | ||
1515 | return true; | |
1516 | } | |
1517 | ||
8a49542c PZ |
1518 | static void perf_group_attach(struct perf_event *event) |
1519 | { | |
c320c7b7 | 1520 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1521 | |
74c3337c PZ |
1522 | /* |
1523 | * We can have double attach due to group movement in perf_event_open. | |
1524 | */ | |
1525 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1526 | return; | |
1527 | ||
8a49542c PZ |
1528 | event->attach_state |= PERF_ATTACH_GROUP; |
1529 | ||
1530 | if (group_leader == event) | |
1531 | return; | |
1532 | ||
652884fe PZ |
1533 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1534 | ||
8a49542c PZ |
1535 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1536 | !is_software_event(event)) | |
1537 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1538 | ||
1539 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1540 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1541 | |
1542 | perf_event__header_size(group_leader); | |
1543 | ||
1544 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1545 | perf_event__header_size(pos); | |
8a49542c PZ |
1546 | } |
1547 | ||
a63eaf34 | 1548 | /* |
cdd6c482 | 1549 | * Remove a event from the lists for its context. |
fccc714b | 1550 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1551 | */ |
04289bb9 | 1552 | static void |
cdd6c482 | 1553 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1554 | { |
68cacd29 | 1555 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1556 | |
1557 | WARN_ON_ONCE(event->ctx != ctx); | |
1558 | lockdep_assert_held(&ctx->lock); | |
1559 | ||
8a49542c PZ |
1560 | /* |
1561 | * We can have double detach due to exit/hot-unplug + close. | |
1562 | */ | |
1563 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1564 | return; |
8a49542c PZ |
1565 | |
1566 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1567 | ||
68cacd29 | 1568 | if (is_cgroup_event(event)) { |
e5d1367f | 1569 | ctx->nr_cgroups--; |
70a01657 PZ |
1570 | /* |
1571 | * Because cgroup events are always per-cpu events, this will | |
1572 | * always be called from the right CPU. | |
1573 | */ | |
68cacd29 SE |
1574 | cpuctx = __get_cpu_context(ctx); |
1575 | /* | |
70a01657 PZ |
1576 | * If there are no more cgroup events then clear cgrp to avoid |
1577 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1578 | */ |
1579 | if (!ctx->nr_cgroups) | |
1580 | cpuctx->cgrp = NULL; | |
1581 | } | |
e5d1367f | 1582 | |
cdd6c482 IM |
1583 | ctx->nr_events--; |
1584 | if (event->attr.inherit_stat) | |
bfbd3381 | 1585 | ctx->nr_stat--; |
8bc20959 | 1586 | |
cdd6c482 | 1587 | list_del_rcu(&event->event_entry); |
04289bb9 | 1588 | |
8a49542c PZ |
1589 | if (event->group_leader == event) |
1590 | list_del_init(&event->group_entry); | |
5c148194 | 1591 | |
96c21a46 | 1592 | update_group_times(event); |
b2e74a26 SE |
1593 | |
1594 | /* | |
1595 | * If event was in error state, then keep it | |
1596 | * that way, otherwise bogus counts will be | |
1597 | * returned on read(). The only way to get out | |
1598 | * of error state is by explicit re-enabling | |
1599 | * of the event | |
1600 | */ | |
1601 | if (event->state > PERF_EVENT_STATE_OFF) | |
1602 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1603 | |
1604 | ctx->generation++; | |
050735b0 PZ |
1605 | } |
1606 | ||
8a49542c | 1607 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1608 | { |
1609 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1610 | struct list_head *list = NULL; |
1611 | ||
1612 | /* | |
1613 | * We can have double detach due to exit/hot-unplug + close. | |
1614 | */ | |
1615 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1616 | return; | |
1617 | ||
1618 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1619 | ||
1620 | /* | |
1621 | * If this is a sibling, remove it from its group. | |
1622 | */ | |
1623 | if (event->group_leader != event) { | |
1624 | list_del_init(&event->group_entry); | |
1625 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1626 | goto out; |
8a49542c PZ |
1627 | } |
1628 | ||
1629 | if (!list_empty(&event->group_entry)) | |
1630 | list = &event->group_entry; | |
2e2af50b | 1631 | |
04289bb9 | 1632 | /* |
cdd6c482 IM |
1633 | * If this was a group event with sibling events then |
1634 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1635 | * to whatever list we are on. |
04289bb9 | 1636 | */ |
cdd6c482 | 1637 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1638 | if (list) |
1639 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1640 | sibling->group_leader = sibling; |
d6f962b5 FW |
1641 | |
1642 | /* Inherit group flags from the previous leader */ | |
1643 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1644 | |
1645 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1646 | } |
c320c7b7 ACM |
1647 | |
1648 | out: | |
1649 | perf_event__header_size(event->group_leader); | |
1650 | ||
1651 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1652 | perf_event__header_size(tmp); | |
04289bb9 IM |
1653 | } |
1654 | ||
fadfe7be JO |
1655 | static bool is_orphaned_event(struct perf_event *event) |
1656 | { | |
a69b0ca4 | 1657 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1658 | } |
1659 | ||
66eb579e MR |
1660 | static inline int pmu_filter_match(struct perf_event *event) |
1661 | { | |
1662 | struct pmu *pmu = event->pmu; | |
1663 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1664 | } | |
1665 | ||
fa66f07a SE |
1666 | static inline int |
1667 | event_filter_match(struct perf_event *event) | |
1668 | { | |
e5d1367f | 1669 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1670 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1671 | } |
1672 | ||
9ffcfa6f SE |
1673 | static void |
1674 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1675 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1676 | struct perf_event_context *ctx) |
3b6f9e5c | 1677 | { |
4158755d | 1678 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1679 | u64 delta; |
652884fe PZ |
1680 | |
1681 | WARN_ON_ONCE(event->ctx != ctx); | |
1682 | lockdep_assert_held(&ctx->lock); | |
1683 | ||
fa66f07a SE |
1684 | /* |
1685 | * An event which could not be activated because of | |
1686 | * filter mismatch still needs to have its timings | |
1687 | * maintained, otherwise bogus information is return | |
1688 | * via read() for time_enabled, time_running: | |
1689 | */ | |
1690 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1691 | && !event_filter_match(event)) { | |
e5d1367f | 1692 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1693 | event->tstamp_running += delta; |
4158755d | 1694 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1695 | } |
1696 | ||
cdd6c482 | 1697 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1698 | return; |
3b6f9e5c | 1699 | |
44377277 AS |
1700 | perf_pmu_disable(event->pmu); |
1701 | ||
28a967c3 PZ |
1702 | event->tstamp_stopped = tstamp; |
1703 | event->pmu->del(event, 0); | |
1704 | event->oncpu = -1; | |
cdd6c482 IM |
1705 | event->state = PERF_EVENT_STATE_INACTIVE; |
1706 | if (event->pending_disable) { | |
1707 | event->pending_disable = 0; | |
1708 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1709 | } |
3b6f9e5c | 1710 | |
cdd6c482 | 1711 | if (!is_software_event(event)) |
3b6f9e5c | 1712 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1713 | if (!--ctx->nr_active) |
1714 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1715 | if (event->attr.freq && event->attr.sample_freq) |
1716 | ctx->nr_freq--; | |
cdd6c482 | 1717 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1718 | cpuctx->exclusive = 0; |
44377277 AS |
1719 | |
1720 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1721 | } |
1722 | ||
d859e29f | 1723 | static void |
cdd6c482 | 1724 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1725 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1726 | struct perf_event_context *ctx) |
d859e29f | 1727 | { |
cdd6c482 | 1728 | struct perf_event *event; |
fa66f07a | 1729 | int state = group_event->state; |
d859e29f | 1730 | |
cdd6c482 | 1731 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1732 | |
1733 | /* | |
1734 | * Schedule out siblings (if any): | |
1735 | */ | |
cdd6c482 IM |
1736 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1737 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1738 | |
fa66f07a | 1739 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1740 | cpuctx->exclusive = 0; |
1741 | } | |
1742 | ||
45a0e07a | 1743 | #define DETACH_GROUP 0x01UL |
0017960f | 1744 | |
0793a61d | 1745 | /* |
cdd6c482 | 1746 | * Cross CPU call to remove a performance event |
0793a61d | 1747 | * |
cdd6c482 | 1748 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1749 | * remove it from the context list. |
1750 | */ | |
fae3fde6 PZ |
1751 | static void |
1752 | __perf_remove_from_context(struct perf_event *event, | |
1753 | struct perf_cpu_context *cpuctx, | |
1754 | struct perf_event_context *ctx, | |
1755 | void *info) | |
0793a61d | 1756 | { |
45a0e07a | 1757 | unsigned long flags = (unsigned long)info; |
0793a61d | 1758 | |
cdd6c482 | 1759 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1760 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1761 | perf_group_detach(event); |
cdd6c482 | 1762 | list_del_event(event, ctx); |
39a43640 PZ |
1763 | |
1764 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1765 | ctx->is_active = 0; |
39a43640 PZ |
1766 | if (ctx->task) { |
1767 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1768 | cpuctx->task_ctx = NULL; | |
1769 | } | |
64ce3126 | 1770 | } |
0793a61d TG |
1771 | } |
1772 | ||
0793a61d | 1773 | /* |
cdd6c482 | 1774 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1775 | * |
cdd6c482 IM |
1776 | * If event->ctx is a cloned context, callers must make sure that |
1777 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1778 | * remains valid. This is OK when called from perf_release since |
1779 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1780 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1781 | * context has been detached from its task. |
0793a61d | 1782 | */ |
45a0e07a | 1783 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1784 | { |
fae3fde6 | 1785 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1786 | |
45a0e07a | 1787 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1788 | } |
1789 | ||
d859e29f | 1790 | /* |
cdd6c482 | 1791 | * Cross CPU call to disable a performance event |
d859e29f | 1792 | */ |
fae3fde6 PZ |
1793 | static void __perf_event_disable(struct perf_event *event, |
1794 | struct perf_cpu_context *cpuctx, | |
1795 | struct perf_event_context *ctx, | |
1796 | void *info) | |
7b648018 | 1797 | { |
fae3fde6 PZ |
1798 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1799 | return; | |
7b648018 | 1800 | |
fae3fde6 PZ |
1801 | update_context_time(ctx); |
1802 | update_cgrp_time_from_event(event); | |
1803 | update_group_times(event); | |
1804 | if (event == event->group_leader) | |
1805 | group_sched_out(event, cpuctx, ctx); | |
1806 | else | |
1807 | event_sched_out(event, cpuctx, ctx); | |
1808 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1809 | } |
1810 | ||
d859e29f | 1811 | /* |
cdd6c482 | 1812 | * Disable a event. |
c93f7669 | 1813 | * |
cdd6c482 IM |
1814 | * If event->ctx is a cloned context, callers must make sure that |
1815 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1816 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1817 | * perf_event_for_each_child or perf_event_for_each because they |
1818 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1819 | * goes to exit will block in perf_event_exit_event(). |
1820 | * | |
cdd6c482 | 1821 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1822 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1823 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1824 | */ |
f63a8daa | 1825 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1826 | { |
cdd6c482 | 1827 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1828 | |
e625cce1 | 1829 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1830 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1831 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1832 | return; |
53cfbf59 | 1833 | } |
e625cce1 | 1834 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1835 | |
fae3fde6 PZ |
1836 | event_function_call(event, __perf_event_disable, NULL); |
1837 | } | |
1838 | ||
1839 | void perf_event_disable_local(struct perf_event *event) | |
1840 | { | |
1841 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1842 | } |
f63a8daa PZ |
1843 | |
1844 | /* | |
1845 | * Strictly speaking kernel users cannot create groups and therefore this | |
1846 | * interface does not need the perf_event_ctx_lock() magic. | |
1847 | */ | |
1848 | void perf_event_disable(struct perf_event *event) | |
1849 | { | |
1850 | struct perf_event_context *ctx; | |
1851 | ||
1852 | ctx = perf_event_ctx_lock(event); | |
1853 | _perf_event_disable(event); | |
1854 | perf_event_ctx_unlock(event, ctx); | |
1855 | } | |
dcfce4a0 | 1856 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1857 | |
e5d1367f SE |
1858 | static void perf_set_shadow_time(struct perf_event *event, |
1859 | struct perf_event_context *ctx, | |
1860 | u64 tstamp) | |
1861 | { | |
1862 | /* | |
1863 | * use the correct time source for the time snapshot | |
1864 | * | |
1865 | * We could get by without this by leveraging the | |
1866 | * fact that to get to this function, the caller | |
1867 | * has most likely already called update_context_time() | |
1868 | * and update_cgrp_time_xx() and thus both timestamp | |
1869 | * are identical (or very close). Given that tstamp is, | |
1870 | * already adjusted for cgroup, we could say that: | |
1871 | * tstamp - ctx->timestamp | |
1872 | * is equivalent to | |
1873 | * tstamp - cgrp->timestamp. | |
1874 | * | |
1875 | * Then, in perf_output_read(), the calculation would | |
1876 | * work with no changes because: | |
1877 | * - event is guaranteed scheduled in | |
1878 | * - no scheduled out in between | |
1879 | * - thus the timestamp would be the same | |
1880 | * | |
1881 | * But this is a bit hairy. | |
1882 | * | |
1883 | * So instead, we have an explicit cgroup call to remain | |
1884 | * within the time time source all along. We believe it | |
1885 | * is cleaner and simpler to understand. | |
1886 | */ | |
1887 | if (is_cgroup_event(event)) | |
1888 | perf_cgroup_set_shadow_time(event, tstamp); | |
1889 | else | |
1890 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1891 | } | |
1892 | ||
4fe757dd PZ |
1893 | #define MAX_INTERRUPTS (~0ULL) |
1894 | ||
1895 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1896 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1897 | |
235c7fc7 | 1898 | static int |
9ffcfa6f | 1899 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1900 | struct perf_cpu_context *cpuctx, |
6e37738a | 1901 | struct perf_event_context *ctx) |
235c7fc7 | 1902 | { |
4158755d | 1903 | u64 tstamp = perf_event_time(event); |
44377277 | 1904 | int ret = 0; |
4158755d | 1905 | |
63342411 PZ |
1906 | lockdep_assert_held(&ctx->lock); |
1907 | ||
cdd6c482 | 1908 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1909 | return 0; |
1910 | ||
cdd6c482 | 1911 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1912 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1913 | |
1914 | /* | |
1915 | * Unthrottle events, since we scheduled we might have missed several | |
1916 | * ticks already, also for a heavily scheduling task there is little | |
1917 | * guarantee it'll get a tick in a timely manner. | |
1918 | */ | |
1919 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1920 | perf_log_throttle(event, 1); | |
1921 | event->hw.interrupts = 0; | |
1922 | } | |
1923 | ||
235c7fc7 IM |
1924 | /* |
1925 | * The new state must be visible before we turn it on in the hardware: | |
1926 | */ | |
1927 | smp_wmb(); | |
1928 | ||
44377277 AS |
1929 | perf_pmu_disable(event->pmu); |
1930 | ||
72f669c0 SL |
1931 | perf_set_shadow_time(event, ctx, tstamp); |
1932 | ||
ec0d7729 AS |
1933 | perf_log_itrace_start(event); |
1934 | ||
a4eaf7f1 | 1935 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1936 | event->state = PERF_EVENT_STATE_INACTIVE; |
1937 | event->oncpu = -1; | |
44377277 AS |
1938 | ret = -EAGAIN; |
1939 | goto out; | |
235c7fc7 IM |
1940 | } |
1941 | ||
00a2916f PZ |
1942 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1943 | ||
cdd6c482 | 1944 | if (!is_software_event(event)) |
3b6f9e5c | 1945 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1946 | if (!ctx->nr_active++) |
1947 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1948 | if (event->attr.freq && event->attr.sample_freq) |
1949 | ctx->nr_freq++; | |
235c7fc7 | 1950 | |
cdd6c482 | 1951 | if (event->attr.exclusive) |
3b6f9e5c PM |
1952 | cpuctx->exclusive = 1; |
1953 | ||
44377277 AS |
1954 | out: |
1955 | perf_pmu_enable(event->pmu); | |
1956 | ||
1957 | return ret; | |
235c7fc7 IM |
1958 | } |
1959 | ||
6751b71e | 1960 | static int |
cdd6c482 | 1961 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1962 | struct perf_cpu_context *cpuctx, |
6e37738a | 1963 | struct perf_event_context *ctx) |
6751b71e | 1964 | { |
6bde9b6c | 1965 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1966 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1967 | u64 now = ctx->time; |
1968 | bool simulate = false; | |
6751b71e | 1969 | |
cdd6c482 | 1970 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1971 | return 0; |
1972 | ||
fbbe0701 | 1973 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1974 | |
9ffcfa6f | 1975 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1976 | pmu->cancel_txn(pmu); |
272325c4 | 1977 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1978 | return -EAGAIN; |
90151c35 | 1979 | } |
6751b71e PM |
1980 | |
1981 | /* | |
1982 | * Schedule in siblings as one group (if any): | |
1983 | */ | |
cdd6c482 | 1984 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1985 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1986 | partial_group = event; |
6751b71e PM |
1987 | goto group_error; |
1988 | } | |
1989 | } | |
1990 | ||
9ffcfa6f | 1991 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1992 | return 0; |
9ffcfa6f | 1993 | |
6751b71e PM |
1994 | group_error: |
1995 | /* | |
1996 | * Groups can be scheduled in as one unit only, so undo any | |
1997 | * partial group before returning: | |
d7842da4 SE |
1998 | * The events up to the failed event are scheduled out normally, |
1999 | * tstamp_stopped will be updated. | |
2000 | * | |
2001 | * The failed events and the remaining siblings need to have | |
2002 | * their timings updated as if they had gone thru event_sched_in() | |
2003 | * and event_sched_out(). This is required to get consistent timings | |
2004 | * across the group. This also takes care of the case where the group | |
2005 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2006 | * the time the event was actually stopped, such that time delta | |
2007 | * calculation in update_event_times() is correct. | |
6751b71e | 2008 | */ |
cdd6c482 IM |
2009 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2010 | if (event == partial_group) | |
d7842da4 SE |
2011 | simulate = true; |
2012 | ||
2013 | if (simulate) { | |
2014 | event->tstamp_running += now - event->tstamp_stopped; | |
2015 | event->tstamp_stopped = now; | |
2016 | } else { | |
2017 | event_sched_out(event, cpuctx, ctx); | |
2018 | } | |
6751b71e | 2019 | } |
9ffcfa6f | 2020 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2021 | |
ad5133b7 | 2022 | pmu->cancel_txn(pmu); |
90151c35 | 2023 | |
272325c4 | 2024 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2025 | |
6751b71e PM |
2026 | return -EAGAIN; |
2027 | } | |
2028 | ||
3b6f9e5c | 2029 | /* |
cdd6c482 | 2030 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2031 | */ |
cdd6c482 | 2032 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2033 | struct perf_cpu_context *cpuctx, |
2034 | int can_add_hw) | |
2035 | { | |
2036 | /* | |
cdd6c482 | 2037 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2038 | */ |
d6f962b5 | 2039 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2040 | return 1; |
2041 | /* | |
2042 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2043 | * events can go on. |
3b6f9e5c PM |
2044 | */ |
2045 | if (cpuctx->exclusive) | |
2046 | return 0; | |
2047 | /* | |
2048 | * If this group is exclusive and there are already | |
cdd6c482 | 2049 | * events on the CPU, it can't go on. |
3b6f9e5c | 2050 | */ |
cdd6c482 | 2051 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2052 | return 0; |
2053 | /* | |
2054 | * Otherwise, try to add it if all previous groups were able | |
2055 | * to go on. | |
2056 | */ | |
2057 | return can_add_hw; | |
2058 | } | |
2059 | ||
cdd6c482 IM |
2060 | static void add_event_to_ctx(struct perf_event *event, |
2061 | struct perf_event_context *ctx) | |
53cfbf59 | 2062 | { |
4158755d SE |
2063 | u64 tstamp = perf_event_time(event); |
2064 | ||
cdd6c482 | 2065 | list_add_event(event, ctx); |
8a49542c | 2066 | perf_group_attach(event); |
4158755d SE |
2067 | event->tstamp_enabled = tstamp; |
2068 | event->tstamp_running = tstamp; | |
2069 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2070 | } |
2071 | ||
3e349507 PZ |
2072 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2073 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2074 | static void |
2075 | ctx_sched_in(struct perf_event_context *ctx, | |
2076 | struct perf_cpu_context *cpuctx, | |
2077 | enum event_type_t event_type, | |
2078 | struct task_struct *task); | |
fe4b04fa | 2079 | |
dce5855b PZ |
2080 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2081 | struct perf_event_context *ctx, | |
2082 | struct task_struct *task) | |
2083 | { | |
2084 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2085 | if (ctx) | |
2086 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2087 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2088 | if (ctx) | |
2089 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2090 | } | |
2091 | ||
3e349507 PZ |
2092 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2093 | struct perf_event_context *task_ctx) | |
0017960f | 2094 | { |
3e349507 PZ |
2095 | perf_pmu_disable(cpuctx->ctx.pmu); |
2096 | if (task_ctx) | |
2097 | task_ctx_sched_out(cpuctx, task_ctx); | |
2098 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2099 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2100 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2101 | } |
2102 | ||
0793a61d | 2103 | /* |
cdd6c482 | 2104 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2105 | * |
2106 | * Must be called with ctx->mutex held | |
0793a61d | 2107 | */ |
fe4b04fa | 2108 | static int __perf_install_in_context(void *info) |
0793a61d | 2109 | { |
39a43640 | 2110 | struct perf_event_context *ctx = info; |
108b02cf | 2111 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2112 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
0793a61d | 2113 | |
63b6da39 | 2114 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2115 | if (ctx->task) { |
b58f6b0d | 2116 | raw_spin_lock(&ctx->lock); |
39a43640 PZ |
2117 | /* |
2118 | * If we hit the 'wrong' task, we've since scheduled and | |
2119 | * everything should be sorted, nothing to do! | |
2120 | */ | |
b58f6b0d | 2121 | task_ctx = ctx; |
39a43640 | 2122 | if (ctx->task != current) |
63b6da39 | 2123 | goto unlock; |
b58f6b0d | 2124 | |
39a43640 PZ |
2125 | /* |
2126 | * If task_ctx is set, it had better be to us. | |
2127 | */ | |
2128 | WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx); | |
63b6da39 PZ |
2129 | } else if (task_ctx) { |
2130 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2131 | } |
b58f6b0d | 2132 | |
39a43640 | 2133 | ctx_resched(cpuctx, task_ctx); |
63b6da39 | 2134 | unlock: |
2c29ef0f | 2135 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2136 | |
2137 | return 0; | |
0793a61d TG |
2138 | } |
2139 | ||
2140 | /* | |
cdd6c482 | 2141 | * Attach a performance event to a context |
0793a61d TG |
2142 | */ |
2143 | static void | |
cdd6c482 IM |
2144 | perf_install_in_context(struct perf_event_context *ctx, |
2145 | struct perf_event *event, | |
0793a61d TG |
2146 | int cpu) |
2147 | { | |
39a43640 PZ |
2148 | struct task_struct *task = NULL; |
2149 | ||
fe4b04fa PZ |
2150 | lockdep_assert_held(&ctx->mutex); |
2151 | ||
c3f00c70 | 2152 | event->ctx = ctx; |
0cda4c02 YZ |
2153 | if (event->cpu != -1) |
2154 | event->cpu = cpu; | |
c3f00c70 | 2155 | |
39a43640 PZ |
2156 | /* |
2157 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2158 | * to be set in case this is the nr_events 0 -> 1 transition. | |
2159 | * | |
2160 | * So what we do is we add the event to the list here, which will allow | |
2161 | * a future context switch to DTRT and then send a racy IPI. If the IPI | |
2162 | * fails to hit the right task, this means a context switch must have | |
2163 | * happened and that will have taken care of business. | |
2164 | */ | |
2165 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 | 2166 | task = ctx->task; |
84c4e620 | 2167 | |
63b6da39 | 2168 | /* |
84c4e620 PZ |
2169 | * If between ctx = find_get_context() and mutex_lock(&ctx->mutex) the |
2170 | * ctx gets destroyed, we must not install an event into it. | |
2171 | * | |
2172 | * This is normally tested for after we acquire the mutex, so this is | |
2173 | * a sanity check. | |
63b6da39 | 2174 | */ |
84c4e620 | 2175 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
63b6da39 PZ |
2176 | raw_spin_unlock_irq(&ctx->lock); |
2177 | return; | |
2178 | } | |
6f932e5b PZ |
2179 | |
2180 | if (ctx->is_active) { | |
2181 | update_context_time(ctx); | |
2182 | update_cgrp_time_from_event(event); | |
2183 | } | |
2184 | ||
39a43640 | 2185 | add_event_to_ctx(event, ctx); |
39a43640 PZ |
2186 | raw_spin_unlock_irq(&ctx->lock); |
2187 | ||
2188 | if (task) | |
2189 | task_function_call(task, __perf_install_in_context, ctx); | |
2190 | else | |
2191 | cpu_function_call(cpu, __perf_install_in_context, ctx); | |
0793a61d TG |
2192 | } |
2193 | ||
fa289bec | 2194 | /* |
cdd6c482 | 2195 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2196 | * Enabling the leader of a group effectively enables all |
2197 | * the group members that aren't explicitly disabled, so we | |
2198 | * have to update their ->tstamp_enabled also. | |
2199 | * Note: this works for group members as well as group leaders | |
2200 | * since the non-leader members' sibling_lists will be empty. | |
2201 | */ | |
1d9b482e | 2202 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2203 | { |
cdd6c482 | 2204 | struct perf_event *sub; |
4158755d | 2205 | u64 tstamp = perf_event_time(event); |
fa289bec | 2206 | |
cdd6c482 | 2207 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2208 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2209 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2210 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2211 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2212 | } |
fa289bec PM |
2213 | } |
2214 | ||
d859e29f | 2215 | /* |
cdd6c482 | 2216 | * Cross CPU call to enable a performance event |
d859e29f | 2217 | */ |
fae3fde6 PZ |
2218 | static void __perf_event_enable(struct perf_event *event, |
2219 | struct perf_cpu_context *cpuctx, | |
2220 | struct perf_event_context *ctx, | |
2221 | void *info) | |
04289bb9 | 2222 | { |
cdd6c482 | 2223 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2224 | struct perf_event_context *task_ctx; |
04289bb9 | 2225 | |
6e801e01 PZ |
2226 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2227 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2228 | return; |
3cbed429 | 2229 | |
4af4998b | 2230 | update_context_time(ctx); |
1d9b482e | 2231 | __perf_event_mark_enabled(event); |
04289bb9 | 2232 | |
fae3fde6 PZ |
2233 | if (!ctx->is_active) |
2234 | return; | |
2235 | ||
e5d1367f | 2236 | if (!event_filter_match(event)) { |
fae3fde6 PZ |
2237 | if (is_cgroup_event(event)) { |
2238 | perf_cgroup_set_timestamp(current, ctx); // XXX ? | |
e5d1367f | 2239 | perf_cgroup_defer_enabled(event); |
fae3fde6 PZ |
2240 | } |
2241 | return; | |
e5d1367f | 2242 | } |
f4c4176f | 2243 | |
04289bb9 | 2244 | /* |
cdd6c482 | 2245 | * If the event is in a group and isn't the group leader, |
d859e29f | 2246 | * then don't put it on unless the group is on. |
04289bb9 | 2247 | */ |
cdd6c482 | 2248 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
fae3fde6 | 2249 | return; |
fe4b04fa | 2250 | |
fae3fde6 PZ |
2251 | task_ctx = cpuctx->task_ctx; |
2252 | if (ctx->task) | |
2253 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2254 | |
fae3fde6 | 2255 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2256 | } |
2257 | ||
d859e29f | 2258 | /* |
cdd6c482 | 2259 | * Enable a event. |
c93f7669 | 2260 | * |
cdd6c482 IM |
2261 | * If event->ctx is a cloned context, callers must make sure that |
2262 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2263 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2264 | * perf_event_for_each_child or perf_event_for_each as described |
2265 | * for perf_event_disable. | |
d859e29f | 2266 | */ |
f63a8daa | 2267 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2268 | { |
cdd6c482 | 2269 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2270 | |
7b648018 | 2271 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2272 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2273 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2274 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2275 | return; |
2276 | } | |
2277 | ||
d859e29f | 2278 | /* |
cdd6c482 | 2279 | * If the event is in error state, clear that first. |
7b648018 PZ |
2280 | * |
2281 | * That way, if we see the event in error state below, we know that it | |
2282 | * has gone back into error state, as distinct from the task having | |
2283 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2284 | */ |
cdd6c482 IM |
2285 | if (event->state == PERF_EVENT_STATE_ERROR) |
2286 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2287 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2288 | |
fae3fde6 | 2289 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2290 | } |
f63a8daa PZ |
2291 | |
2292 | /* | |
2293 | * See perf_event_disable(); | |
2294 | */ | |
2295 | void perf_event_enable(struct perf_event *event) | |
2296 | { | |
2297 | struct perf_event_context *ctx; | |
2298 | ||
2299 | ctx = perf_event_ctx_lock(event); | |
2300 | _perf_event_enable(event); | |
2301 | perf_event_ctx_unlock(event, ctx); | |
2302 | } | |
dcfce4a0 | 2303 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2304 | |
f63a8daa | 2305 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2306 | { |
2023b359 | 2307 | /* |
cdd6c482 | 2308 | * not supported on inherited events |
2023b359 | 2309 | */ |
2e939d1d | 2310 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2311 | return -EINVAL; |
2312 | ||
cdd6c482 | 2313 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2314 | _perf_event_enable(event); |
2023b359 PZ |
2315 | |
2316 | return 0; | |
79f14641 | 2317 | } |
f63a8daa PZ |
2318 | |
2319 | /* | |
2320 | * See perf_event_disable() | |
2321 | */ | |
2322 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2323 | { | |
2324 | struct perf_event_context *ctx; | |
2325 | int ret; | |
2326 | ||
2327 | ctx = perf_event_ctx_lock(event); | |
2328 | ret = _perf_event_refresh(event, refresh); | |
2329 | perf_event_ctx_unlock(event, ctx); | |
2330 | ||
2331 | return ret; | |
2332 | } | |
26ca5c11 | 2333 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2334 | |
5b0311e1 FW |
2335 | static void ctx_sched_out(struct perf_event_context *ctx, |
2336 | struct perf_cpu_context *cpuctx, | |
2337 | enum event_type_t event_type) | |
235c7fc7 | 2338 | { |
db24d33e | 2339 | int is_active = ctx->is_active; |
c994d613 | 2340 | struct perf_event *event; |
235c7fc7 | 2341 | |
c994d613 | 2342 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2343 | |
39a43640 PZ |
2344 | if (likely(!ctx->nr_events)) { |
2345 | /* | |
2346 | * See __perf_remove_from_context(). | |
2347 | */ | |
2348 | WARN_ON_ONCE(ctx->is_active); | |
2349 | if (ctx->task) | |
2350 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2351 | return; |
39a43640 PZ |
2352 | } |
2353 | ||
db24d33e | 2354 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2355 | if (!(ctx->is_active & EVENT_ALL)) |
2356 | ctx->is_active = 0; | |
2357 | ||
63e30d3e PZ |
2358 | if (ctx->task) { |
2359 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2360 | if (!ctx->is_active) | |
2361 | cpuctx->task_ctx = NULL; | |
2362 | } | |
facc4307 | 2363 | |
3cbaa590 PZ |
2364 | is_active ^= ctx->is_active; /* changed bits */ |
2365 | ||
2366 | if (is_active & EVENT_TIME) { | |
2367 | /* update (and stop) ctx time */ | |
2368 | update_context_time(ctx); | |
2369 | update_cgrp_time_from_cpuctx(cpuctx); | |
2370 | } | |
2371 | ||
2372 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) | |
facc4307 | 2373 | return; |
5b0311e1 | 2374 | |
075e0b00 | 2375 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2376 | if (is_active & EVENT_PINNED) { |
889ff015 FW |
2377 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2378 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2379 | } |
889ff015 | 2380 | |
3cbaa590 | 2381 | if (is_active & EVENT_FLEXIBLE) { |
889ff015 | 2382 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2383 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2384 | } |
1b9a644f | 2385 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2386 | } |
2387 | ||
564c2b21 | 2388 | /* |
5a3126d4 PZ |
2389 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2390 | * cloned from the same version of the same context. | |
2391 | * | |
2392 | * Equivalence is measured using a generation number in the context that is | |
2393 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2394 | * and list_del_event(). | |
564c2b21 | 2395 | */ |
cdd6c482 IM |
2396 | static int context_equiv(struct perf_event_context *ctx1, |
2397 | struct perf_event_context *ctx2) | |
564c2b21 | 2398 | { |
211de6eb PZ |
2399 | lockdep_assert_held(&ctx1->lock); |
2400 | lockdep_assert_held(&ctx2->lock); | |
2401 | ||
5a3126d4 PZ |
2402 | /* Pinning disables the swap optimization */ |
2403 | if (ctx1->pin_count || ctx2->pin_count) | |
2404 | return 0; | |
2405 | ||
2406 | /* If ctx1 is the parent of ctx2 */ | |
2407 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2408 | return 1; | |
2409 | ||
2410 | /* If ctx2 is the parent of ctx1 */ | |
2411 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2412 | return 1; | |
2413 | ||
2414 | /* | |
2415 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2416 | * hierarchy, see perf_event_init_context(). | |
2417 | */ | |
2418 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2419 | ctx1->parent_gen == ctx2->parent_gen) | |
2420 | return 1; | |
2421 | ||
2422 | /* Unmatched */ | |
2423 | return 0; | |
564c2b21 PM |
2424 | } |
2425 | ||
cdd6c482 IM |
2426 | static void __perf_event_sync_stat(struct perf_event *event, |
2427 | struct perf_event *next_event) | |
bfbd3381 PZ |
2428 | { |
2429 | u64 value; | |
2430 | ||
cdd6c482 | 2431 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2432 | return; |
2433 | ||
2434 | /* | |
cdd6c482 | 2435 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2436 | * because we're in the middle of a context switch and have IRQs |
2437 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2438 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2439 | * don't need to use it. |
2440 | */ | |
cdd6c482 IM |
2441 | switch (event->state) { |
2442 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2443 | event->pmu->read(event); |
2444 | /* fall-through */ | |
bfbd3381 | 2445 | |
cdd6c482 IM |
2446 | case PERF_EVENT_STATE_INACTIVE: |
2447 | update_event_times(event); | |
bfbd3381 PZ |
2448 | break; |
2449 | ||
2450 | default: | |
2451 | break; | |
2452 | } | |
2453 | ||
2454 | /* | |
cdd6c482 | 2455 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2456 | * values when we flip the contexts. |
2457 | */ | |
e7850595 PZ |
2458 | value = local64_read(&next_event->count); |
2459 | value = local64_xchg(&event->count, value); | |
2460 | local64_set(&next_event->count, value); | |
bfbd3381 | 2461 | |
cdd6c482 IM |
2462 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2463 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2464 | |
bfbd3381 | 2465 | /* |
19d2e755 | 2466 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2467 | */ |
cdd6c482 IM |
2468 | perf_event_update_userpage(event); |
2469 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2470 | } |
2471 | ||
cdd6c482 IM |
2472 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2473 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2474 | { |
cdd6c482 | 2475 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2476 | |
2477 | if (!ctx->nr_stat) | |
2478 | return; | |
2479 | ||
02ffdbc8 PZ |
2480 | update_context_time(ctx); |
2481 | ||
cdd6c482 IM |
2482 | event = list_first_entry(&ctx->event_list, |
2483 | struct perf_event, event_entry); | |
bfbd3381 | 2484 | |
cdd6c482 IM |
2485 | next_event = list_first_entry(&next_ctx->event_list, |
2486 | struct perf_event, event_entry); | |
bfbd3381 | 2487 | |
cdd6c482 IM |
2488 | while (&event->event_entry != &ctx->event_list && |
2489 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2490 | |
cdd6c482 | 2491 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2492 | |
cdd6c482 IM |
2493 | event = list_next_entry(event, event_entry); |
2494 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2495 | } |
2496 | } | |
2497 | ||
fe4b04fa PZ |
2498 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2499 | struct task_struct *next) | |
0793a61d | 2500 | { |
8dc85d54 | 2501 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2502 | struct perf_event_context *next_ctx; |
5a3126d4 | 2503 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2504 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2505 | int do_switch = 1; |
0793a61d | 2506 | |
108b02cf PZ |
2507 | if (likely(!ctx)) |
2508 | return; | |
10989fb2 | 2509 | |
108b02cf PZ |
2510 | cpuctx = __get_cpu_context(ctx); |
2511 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2512 | return; |
2513 | ||
c93f7669 | 2514 | rcu_read_lock(); |
8dc85d54 | 2515 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2516 | if (!next_ctx) |
2517 | goto unlock; | |
2518 | ||
2519 | parent = rcu_dereference(ctx->parent_ctx); | |
2520 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2521 | ||
2522 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2523 | if (!parent && !next_parent) |
5a3126d4 PZ |
2524 | goto unlock; |
2525 | ||
2526 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2527 | /* |
2528 | * Looks like the two contexts are clones, so we might be | |
2529 | * able to optimize the context switch. We lock both | |
2530 | * contexts and check that they are clones under the | |
2531 | * lock (including re-checking that neither has been | |
2532 | * uncloned in the meantime). It doesn't matter which | |
2533 | * order we take the locks because no other cpu could | |
2534 | * be trying to lock both of these tasks. | |
2535 | */ | |
e625cce1 TG |
2536 | raw_spin_lock(&ctx->lock); |
2537 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2538 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2539 | WRITE_ONCE(ctx->task, next); |
2540 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2541 | |
2542 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2543 | ||
63b6da39 PZ |
2544 | /* |
2545 | * RCU_INIT_POINTER here is safe because we've not | |
2546 | * modified the ctx and the above modification of | |
2547 | * ctx->task and ctx->task_ctx_data are immaterial | |
2548 | * since those values are always verified under | |
2549 | * ctx->lock which we're now holding. | |
2550 | */ | |
2551 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2552 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2553 | ||
c93f7669 | 2554 | do_switch = 0; |
bfbd3381 | 2555 | |
cdd6c482 | 2556 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2557 | } |
e625cce1 TG |
2558 | raw_spin_unlock(&next_ctx->lock); |
2559 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2560 | } |
5a3126d4 | 2561 | unlock: |
c93f7669 | 2562 | rcu_read_unlock(); |
564c2b21 | 2563 | |
c93f7669 | 2564 | if (do_switch) { |
facc4307 | 2565 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2566 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2567 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2568 | } |
0793a61d TG |
2569 | } |
2570 | ||
ba532500 YZ |
2571 | void perf_sched_cb_dec(struct pmu *pmu) |
2572 | { | |
2573 | this_cpu_dec(perf_sched_cb_usages); | |
2574 | } | |
2575 | ||
2576 | void perf_sched_cb_inc(struct pmu *pmu) | |
2577 | { | |
2578 | this_cpu_inc(perf_sched_cb_usages); | |
2579 | } | |
2580 | ||
2581 | /* | |
2582 | * This function provides the context switch callback to the lower code | |
2583 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2584 | */ | |
2585 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2586 | struct task_struct *next, | |
2587 | bool sched_in) | |
2588 | { | |
2589 | struct perf_cpu_context *cpuctx; | |
2590 | struct pmu *pmu; | |
2591 | unsigned long flags; | |
2592 | ||
2593 | if (prev == next) | |
2594 | return; | |
2595 | ||
2596 | local_irq_save(flags); | |
2597 | ||
2598 | rcu_read_lock(); | |
2599 | ||
2600 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2601 | if (pmu->sched_task) { | |
2602 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2603 | ||
2604 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2605 | ||
2606 | perf_pmu_disable(pmu); | |
2607 | ||
2608 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2609 | ||
2610 | perf_pmu_enable(pmu); | |
2611 | ||
2612 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2613 | } | |
2614 | } | |
2615 | ||
2616 | rcu_read_unlock(); | |
2617 | ||
2618 | local_irq_restore(flags); | |
2619 | } | |
2620 | ||
45ac1403 AH |
2621 | static void perf_event_switch(struct task_struct *task, |
2622 | struct task_struct *next_prev, bool sched_in); | |
2623 | ||
8dc85d54 PZ |
2624 | #define for_each_task_context_nr(ctxn) \ |
2625 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2626 | ||
2627 | /* | |
2628 | * Called from scheduler to remove the events of the current task, | |
2629 | * with interrupts disabled. | |
2630 | * | |
2631 | * We stop each event and update the event value in event->count. | |
2632 | * | |
2633 | * This does not protect us against NMI, but disable() | |
2634 | * sets the disabled bit in the control field of event _before_ | |
2635 | * accessing the event control register. If a NMI hits, then it will | |
2636 | * not restart the event. | |
2637 | */ | |
ab0cce56 JO |
2638 | void __perf_event_task_sched_out(struct task_struct *task, |
2639 | struct task_struct *next) | |
8dc85d54 PZ |
2640 | { |
2641 | int ctxn; | |
2642 | ||
ba532500 YZ |
2643 | if (__this_cpu_read(perf_sched_cb_usages)) |
2644 | perf_pmu_sched_task(task, next, false); | |
2645 | ||
45ac1403 AH |
2646 | if (atomic_read(&nr_switch_events)) |
2647 | perf_event_switch(task, next, false); | |
2648 | ||
8dc85d54 PZ |
2649 | for_each_task_context_nr(ctxn) |
2650 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2651 | |
2652 | /* | |
2653 | * if cgroup events exist on this CPU, then we need | |
2654 | * to check if we have to switch out PMU state. | |
2655 | * cgroup event are system-wide mode only | |
2656 | */ | |
4a32fea9 | 2657 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2658 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2659 | } |
2660 | ||
3e349507 PZ |
2661 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2662 | struct perf_event_context *ctx) | |
a08b159f | 2663 | { |
a63eaf34 PM |
2664 | if (!cpuctx->task_ctx) |
2665 | return; | |
012b84da IM |
2666 | |
2667 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2668 | return; | |
2669 | ||
04dc2dbb | 2670 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2671 | } |
2672 | ||
5b0311e1 FW |
2673 | /* |
2674 | * Called with IRQs disabled | |
2675 | */ | |
2676 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2677 | enum event_type_t event_type) | |
2678 | { | |
2679 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2680 | } |
2681 | ||
235c7fc7 | 2682 | static void |
5b0311e1 | 2683 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2684 | struct perf_cpu_context *cpuctx) |
0793a61d | 2685 | { |
cdd6c482 | 2686 | struct perf_event *event; |
0793a61d | 2687 | |
889ff015 FW |
2688 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2689 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2690 | continue; |
5632ab12 | 2691 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2692 | continue; |
2693 | ||
e5d1367f SE |
2694 | /* may need to reset tstamp_enabled */ |
2695 | if (is_cgroup_event(event)) | |
2696 | perf_cgroup_mark_enabled(event, ctx); | |
2697 | ||
8c9ed8e1 | 2698 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2699 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2700 | |
2701 | /* | |
2702 | * If this pinned group hasn't been scheduled, | |
2703 | * put it in error state. | |
2704 | */ | |
cdd6c482 IM |
2705 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2706 | update_group_times(event); | |
2707 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2708 | } |
3b6f9e5c | 2709 | } |
5b0311e1 FW |
2710 | } |
2711 | ||
2712 | static void | |
2713 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2714 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2715 | { |
2716 | struct perf_event *event; | |
2717 | int can_add_hw = 1; | |
3b6f9e5c | 2718 | |
889ff015 FW |
2719 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2720 | /* Ignore events in OFF or ERROR state */ | |
2721 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2722 | continue; |
04289bb9 IM |
2723 | /* |
2724 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2725 | * of events: |
04289bb9 | 2726 | */ |
5632ab12 | 2727 | if (!event_filter_match(event)) |
0793a61d TG |
2728 | continue; |
2729 | ||
e5d1367f SE |
2730 | /* may need to reset tstamp_enabled */ |
2731 | if (is_cgroup_event(event)) | |
2732 | perf_cgroup_mark_enabled(event, ctx); | |
2733 | ||
9ed6060d | 2734 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2735 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2736 | can_add_hw = 0; |
9ed6060d | 2737 | } |
0793a61d | 2738 | } |
5b0311e1 FW |
2739 | } |
2740 | ||
2741 | static void | |
2742 | ctx_sched_in(struct perf_event_context *ctx, | |
2743 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2744 | enum event_type_t event_type, |
2745 | struct task_struct *task) | |
5b0311e1 | 2746 | { |
db24d33e | 2747 | int is_active = ctx->is_active; |
c994d613 PZ |
2748 | u64 now; |
2749 | ||
2750 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2751 | |
5b0311e1 | 2752 | if (likely(!ctx->nr_events)) |
facc4307 | 2753 | return; |
5b0311e1 | 2754 | |
3cbaa590 | 2755 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
2756 | if (ctx->task) { |
2757 | if (!is_active) | |
2758 | cpuctx->task_ctx = ctx; | |
2759 | else | |
2760 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2761 | } | |
2762 | ||
3cbaa590 PZ |
2763 | is_active ^= ctx->is_active; /* changed bits */ |
2764 | ||
2765 | if (is_active & EVENT_TIME) { | |
2766 | /* start ctx time */ | |
2767 | now = perf_clock(); | |
2768 | ctx->timestamp = now; | |
2769 | perf_cgroup_set_timestamp(task, ctx); | |
2770 | } | |
2771 | ||
5b0311e1 FW |
2772 | /* |
2773 | * First go through the list and put on any pinned groups | |
2774 | * in order to give them the best chance of going on. | |
2775 | */ | |
3cbaa590 | 2776 | if (is_active & EVENT_PINNED) |
6e37738a | 2777 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2778 | |
2779 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 2780 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 2781 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2782 | } |
2783 | ||
329c0e01 | 2784 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2785 | enum event_type_t event_type, |
2786 | struct task_struct *task) | |
329c0e01 FW |
2787 | { |
2788 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2789 | ||
e5d1367f | 2790 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2791 | } |
2792 | ||
e5d1367f SE |
2793 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2794 | struct task_struct *task) | |
235c7fc7 | 2795 | { |
108b02cf | 2796 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2797 | |
108b02cf | 2798 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2799 | if (cpuctx->task_ctx == ctx) |
2800 | return; | |
2801 | ||
facc4307 | 2802 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2803 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2804 | /* |
2805 | * We want to keep the following priority order: | |
2806 | * cpu pinned (that don't need to move), task pinned, | |
2807 | * cpu flexible, task flexible. | |
2808 | */ | |
2809 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2810 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2811 | perf_pmu_enable(ctx->pmu); |
2812 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2813 | } |
2814 | ||
8dc85d54 PZ |
2815 | /* |
2816 | * Called from scheduler to add the events of the current task | |
2817 | * with interrupts disabled. | |
2818 | * | |
2819 | * We restore the event value and then enable it. | |
2820 | * | |
2821 | * This does not protect us against NMI, but enable() | |
2822 | * sets the enabled bit in the control field of event _before_ | |
2823 | * accessing the event control register. If a NMI hits, then it will | |
2824 | * keep the event running. | |
2825 | */ | |
ab0cce56 JO |
2826 | void __perf_event_task_sched_in(struct task_struct *prev, |
2827 | struct task_struct *task) | |
8dc85d54 PZ |
2828 | { |
2829 | struct perf_event_context *ctx; | |
2830 | int ctxn; | |
2831 | ||
7e41d177 PZ |
2832 | /* |
2833 | * If cgroup events exist on this CPU, then we need to check if we have | |
2834 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2835 | * | |
2836 | * Since cgroup events are CPU events, we must schedule these in before | |
2837 | * we schedule in the task events. | |
2838 | */ | |
2839 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2840 | perf_cgroup_sched_in(prev, task); | |
2841 | ||
8dc85d54 PZ |
2842 | for_each_task_context_nr(ctxn) { |
2843 | ctx = task->perf_event_ctxp[ctxn]; | |
2844 | if (likely(!ctx)) | |
2845 | continue; | |
2846 | ||
e5d1367f | 2847 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2848 | } |
d010b332 | 2849 | |
45ac1403 AH |
2850 | if (atomic_read(&nr_switch_events)) |
2851 | perf_event_switch(task, prev, true); | |
2852 | ||
ba532500 YZ |
2853 | if (__this_cpu_read(perf_sched_cb_usages)) |
2854 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2855 | } |
2856 | ||
abd50713 PZ |
2857 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2858 | { | |
2859 | u64 frequency = event->attr.sample_freq; | |
2860 | u64 sec = NSEC_PER_SEC; | |
2861 | u64 divisor, dividend; | |
2862 | ||
2863 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2864 | ||
2865 | count_fls = fls64(count); | |
2866 | nsec_fls = fls64(nsec); | |
2867 | frequency_fls = fls64(frequency); | |
2868 | sec_fls = 30; | |
2869 | ||
2870 | /* | |
2871 | * We got @count in @nsec, with a target of sample_freq HZ | |
2872 | * the target period becomes: | |
2873 | * | |
2874 | * @count * 10^9 | |
2875 | * period = ------------------- | |
2876 | * @nsec * sample_freq | |
2877 | * | |
2878 | */ | |
2879 | ||
2880 | /* | |
2881 | * Reduce accuracy by one bit such that @a and @b converge | |
2882 | * to a similar magnitude. | |
2883 | */ | |
fe4b04fa | 2884 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2885 | do { \ |
2886 | if (a##_fls > b##_fls) { \ | |
2887 | a >>= 1; \ | |
2888 | a##_fls--; \ | |
2889 | } else { \ | |
2890 | b >>= 1; \ | |
2891 | b##_fls--; \ | |
2892 | } \ | |
2893 | } while (0) | |
2894 | ||
2895 | /* | |
2896 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2897 | * the other, so that finally we can do a u64/u64 division. | |
2898 | */ | |
2899 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2900 | REDUCE_FLS(nsec, frequency); | |
2901 | REDUCE_FLS(sec, count); | |
2902 | } | |
2903 | ||
2904 | if (count_fls + sec_fls > 64) { | |
2905 | divisor = nsec * frequency; | |
2906 | ||
2907 | while (count_fls + sec_fls > 64) { | |
2908 | REDUCE_FLS(count, sec); | |
2909 | divisor >>= 1; | |
2910 | } | |
2911 | ||
2912 | dividend = count * sec; | |
2913 | } else { | |
2914 | dividend = count * sec; | |
2915 | ||
2916 | while (nsec_fls + frequency_fls > 64) { | |
2917 | REDUCE_FLS(nsec, frequency); | |
2918 | dividend >>= 1; | |
2919 | } | |
2920 | ||
2921 | divisor = nsec * frequency; | |
2922 | } | |
2923 | ||
f6ab91ad PZ |
2924 | if (!divisor) |
2925 | return dividend; | |
2926 | ||
abd50713 PZ |
2927 | return div64_u64(dividend, divisor); |
2928 | } | |
2929 | ||
e050e3f0 SE |
2930 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2931 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2932 | ||
f39d47ff | 2933 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2934 | { |
cdd6c482 | 2935 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2936 | s64 period, sample_period; |
bd2b5b12 PZ |
2937 | s64 delta; |
2938 | ||
abd50713 | 2939 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2940 | |
2941 | delta = (s64)(period - hwc->sample_period); | |
2942 | delta = (delta + 7) / 8; /* low pass filter */ | |
2943 | ||
2944 | sample_period = hwc->sample_period + delta; | |
2945 | ||
2946 | if (!sample_period) | |
2947 | sample_period = 1; | |
2948 | ||
bd2b5b12 | 2949 | hwc->sample_period = sample_period; |
abd50713 | 2950 | |
e7850595 | 2951 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2952 | if (disable) |
2953 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2954 | ||
e7850595 | 2955 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2956 | |
2957 | if (disable) | |
2958 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2959 | } |
bd2b5b12 PZ |
2960 | } |
2961 | ||
e050e3f0 SE |
2962 | /* |
2963 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2964 | * events. At the same time, make sure, having freq events does not change | |
2965 | * the rate of unthrottling as that would introduce bias. | |
2966 | */ | |
2967 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2968 | int needs_unthr) | |
60db5e09 | 2969 | { |
cdd6c482 IM |
2970 | struct perf_event *event; |
2971 | struct hw_perf_event *hwc; | |
e050e3f0 | 2972 | u64 now, period = TICK_NSEC; |
abd50713 | 2973 | s64 delta; |
60db5e09 | 2974 | |
e050e3f0 SE |
2975 | /* |
2976 | * only need to iterate over all events iff: | |
2977 | * - context have events in frequency mode (needs freq adjust) | |
2978 | * - there are events to unthrottle on this cpu | |
2979 | */ | |
2980 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2981 | return; |
2982 | ||
e050e3f0 | 2983 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2984 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2985 | |
03541f8b | 2986 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2987 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2988 | continue; |
2989 | ||
5632ab12 | 2990 | if (!event_filter_match(event)) |
5d27c23d PZ |
2991 | continue; |
2992 | ||
44377277 AS |
2993 | perf_pmu_disable(event->pmu); |
2994 | ||
cdd6c482 | 2995 | hwc = &event->hw; |
6a24ed6c | 2996 | |
ae23bff1 | 2997 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2998 | hwc->interrupts = 0; |
cdd6c482 | 2999 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3000 | event->pmu->start(event, 0); |
a78ac325 PZ |
3001 | } |
3002 | ||
cdd6c482 | 3003 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3004 | goto next; |
60db5e09 | 3005 | |
e050e3f0 SE |
3006 | /* |
3007 | * stop the event and update event->count | |
3008 | */ | |
3009 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3010 | ||
e7850595 | 3011 | now = local64_read(&event->count); |
abd50713 PZ |
3012 | delta = now - hwc->freq_count_stamp; |
3013 | hwc->freq_count_stamp = now; | |
60db5e09 | 3014 | |
e050e3f0 SE |
3015 | /* |
3016 | * restart the event | |
3017 | * reload only if value has changed | |
f39d47ff SE |
3018 | * we have stopped the event so tell that |
3019 | * to perf_adjust_period() to avoid stopping it | |
3020 | * twice. | |
e050e3f0 | 3021 | */ |
abd50713 | 3022 | if (delta > 0) |
f39d47ff | 3023 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3024 | |
3025 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3026 | next: |
3027 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3028 | } |
e050e3f0 | 3029 | |
f39d47ff | 3030 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3031 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3032 | } |
3033 | ||
235c7fc7 | 3034 | /* |
cdd6c482 | 3035 | * Round-robin a context's events: |
235c7fc7 | 3036 | */ |
cdd6c482 | 3037 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3038 | { |
dddd3379 TG |
3039 | /* |
3040 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3041 | * disabled by the inheritance code. | |
3042 | */ | |
3043 | if (!ctx->rotate_disable) | |
3044 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3045 | } |
3046 | ||
9e630205 | 3047 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3048 | { |
8dc85d54 | 3049 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3050 | int rotate = 0; |
7fc23a53 | 3051 | |
b5ab4cd5 | 3052 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3053 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3054 | rotate = 1; | |
3055 | } | |
235c7fc7 | 3056 | |
8dc85d54 | 3057 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3058 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3059 | if (ctx->nr_events != ctx->nr_active) |
3060 | rotate = 1; | |
3061 | } | |
9717e6cd | 3062 | |
e050e3f0 | 3063 | if (!rotate) |
0f5a2601 PZ |
3064 | goto done; |
3065 | ||
facc4307 | 3066 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3067 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3068 | |
e050e3f0 SE |
3069 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3070 | if (ctx) | |
3071 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3072 | |
e050e3f0 SE |
3073 | rotate_ctx(&cpuctx->ctx); |
3074 | if (ctx) | |
3075 | rotate_ctx(ctx); | |
235c7fc7 | 3076 | |
e050e3f0 | 3077 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3078 | |
0f5a2601 PZ |
3079 | perf_pmu_enable(cpuctx->ctx.pmu); |
3080 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3081 | done: |
9e630205 SE |
3082 | |
3083 | return rotate; | |
e9d2b064 PZ |
3084 | } |
3085 | ||
026249ef FW |
3086 | #ifdef CONFIG_NO_HZ_FULL |
3087 | bool perf_event_can_stop_tick(void) | |
3088 | { | |
948b26b6 | 3089 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3090 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3091 | return false; |
d84153d6 FW |
3092 | else |
3093 | return true; | |
026249ef FW |
3094 | } |
3095 | #endif | |
3096 | ||
e9d2b064 PZ |
3097 | void perf_event_task_tick(void) |
3098 | { | |
2fde4f94 MR |
3099 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3100 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3101 | int throttled; |
b5ab4cd5 | 3102 | |
e9d2b064 PZ |
3103 | WARN_ON(!irqs_disabled()); |
3104 | ||
e050e3f0 SE |
3105 | __this_cpu_inc(perf_throttled_seq); |
3106 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3107 | ||
2fde4f94 | 3108 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3109 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3110 | } |
3111 | ||
889ff015 FW |
3112 | static int event_enable_on_exec(struct perf_event *event, |
3113 | struct perf_event_context *ctx) | |
3114 | { | |
3115 | if (!event->attr.enable_on_exec) | |
3116 | return 0; | |
3117 | ||
3118 | event->attr.enable_on_exec = 0; | |
3119 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3120 | return 0; | |
3121 | ||
1d9b482e | 3122 | __perf_event_mark_enabled(event); |
889ff015 FW |
3123 | |
3124 | return 1; | |
3125 | } | |
3126 | ||
57e7986e | 3127 | /* |
cdd6c482 | 3128 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3129 | * This expects task == current. |
3130 | */ | |
c1274499 | 3131 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3132 | { |
c1274499 | 3133 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3134 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3135 | struct perf_event *event; |
57e7986e PM |
3136 | unsigned long flags; |
3137 | int enabled = 0; | |
3138 | ||
3139 | local_irq_save(flags); | |
c1274499 | 3140 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3141 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3142 | goto out; |
3143 | ||
3e349507 PZ |
3144 | cpuctx = __get_cpu_context(ctx); |
3145 | perf_ctx_lock(cpuctx, ctx); | |
3146 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3147 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3148 | |
3149 | /* | |
3e349507 | 3150 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3151 | */ |
3e349507 | 3152 | if (enabled) { |
211de6eb | 3153 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3154 | ctx_resched(cpuctx, ctx); |
3155 | } | |
3156 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3157 | |
9ed6060d | 3158 | out: |
57e7986e | 3159 | local_irq_restore(flags); |
211de6eb PZ |
3160 | |
3161 | if (clone_ctx) | |
3162 | put_ctx(clone_ctx); | |
57e7986e PM |
3163 | } |
3164 | ||
e041e328 PZ |
3165 | void perf_event_exec(void) |
3166 | { | |
e041e328 PZ |
3167 | int ctxn; |
3168 | ||
3169 | rcu_read_lock(); | |
c1274499 PZ |
3170 | for_each_task_context_nr(ctxn) |
3171 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3172 | rcu_read_unlock(); |
3173 | } | |
3174 | ||
0492d4c5 PZ |
3175 | struct perf_read_data { |
3176 | struct perf_event *event; | |
3177 | bool group; | |
7d88962e | 3178 | int ret; |
0492d4c5 PZ |
3179 | }; |
3180 | ||
0793a61d | 3181 | /* |
cdd6c482 | 3182 | * Cross CPU call to read the hardware event |
0793a61d | 3183 | */ |
cdd6c482 | 3184 | static void __perf_event_read(void *info) |
0793a61d | 3185 | { |
0492d4c5 PZ |
3186 | struct perf_read_data *data = info; |
3187 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3188 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3189 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3190 | struct pmu *pmu = event->pmu; |
621a01ea | 3191 | |
e1ac3614 PM |
3192 | /* |
3193 | * If this is a task context, we need to check whether it is | |
3194 | * the current task context of this cpu. If not it has been | |
3195 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3196 | * event->count would have been updated to a recent sample |
3197 | * when the event was scheduled out. | |
e1ac3614 PM |
3198 | */ |
3199 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3200 | return; | |
3201 | ||
e625cce1 | 3202 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3203 | if (ctx->is_active) { |
542e72fc | 3204 | update_context_time(ctx); |
e5d1367f SE |
3205 | update_cgrp_time_from_event(event); |
3206 | } | |
0492d4c5 | 3207 | |
cdd6c482 | 3208 | update_event_times(event); |
4a00c16e SB |
3209 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3210 | goto unlock; | |
0492d4c5 | 3211 | |
4a00c16e SB |
3212 | if (!data->group) { |
3213 | pmu->read(event); | |
3214 | data->ret = 0; | |
0492d4c5 | 3215 | goto unlock; |
4a00c16e SB |
3216 | } |
3217 | ||
3218 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3219 | ||
3220 | pmu->read(event); | |
0492d4c5 PZ |
3221 | |
3222 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3223 | update_event_times(sub); | |
4a00c16e SB |
3224 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3225 | /* | |
3226 | * Use sibling's PMU rather than @event's since | |
3227 | * sibling could be on different (eg: software) PMU. | |
3228 | */ | |
0492d4c5 | 3229 | sub->pmu->read(sub); |
4a00c16e | 3230 | } |
0492d4c5 | 3231 | } |
4a00c16e SB |
3232 | |
3233 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3234 | |
3235 | unlock: | |
e625cce1 | 3236 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3237 | } |
3238 | ||
b5e58793 PZ |
3239 | static inline u64 perf_event_count(struct perf_event *event) |
3240 | { | |
eacd3ecc MF |
3241 | if (event->pmu->count) |
3242 | return event->pmu->count(event); | |
3243 | ||
3244 | return __perf_event_count(event); | |
b5e58793 PZ |
3245 | } |
3246 | ||
ffe8690c KX |
3247 | /* |
3248 | * NMI-safe method to read a local event, that is an event that | |
3249 | * is: | |
3250 | * - either for the current task, or for this CPU | |
3251 | * - does not have inherit set, for inherited task events | |
3252 | * will not be local and we cannot read them atomically | |
3253 | * - must not have a pmu::count method | |
3254 | */ | |
3255 | u64 perf_event_read_local(struct perf_event *event) | |
3256 | { | |
3257 | unsigned long flags; | |
3258 | u64 val; | |
3259 | ||
3260 | /* | |
3261 | * Disabling interrupts avoids all counter scheduling (context | |
3262 | * switches, timer based rotation and IPIs). | |
3263 | */ | |
3264 | local_irq_save(flags); | |
3265 | ||
3266 | /* If this is a per-task event, it must be for current */ | |
3267 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3268 | event->hw.target != current); | |
3269 | ||
3270 | /* If this is a per-CPU event, it must be for this CPU */ | |
3271 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3272 | event->cpu != smp_processor_id()); | |
3273 | ||
3274 | /* | |
3275 | * It must not be an event with inherit set, we cannot read | |
3276 | * all child counters from atomic context. | |
3277 | */ | |
3278 | WARN_ON_ONCE(event->attr.inherit); | |
3279 | ||
3280 | /* | |
3281 | * It must not have a pmu::count method, those are not | |
3282 | * NMI safe. | |
3283 | */ | |
3284 | WARN_ON_ONCE(event->pmu->count); | |
3285 | ||
3286 | /* | |
3287 | * If the event is currently on this CPU, its either a per-task event, | |
3288 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3289 | * oncpu == -1). | |
3290 | */ | |
3291 | if (event->oncpu == smp_processor_id()) | |
3292 | event->pmu->read(event); | |
3293 | ||
3294 | val = local64_read(&event->count); | |
3295 | local_irq_restore(flags); | |
3296 | ||
3297 | return val; | |
3298 | } | |
3299 | ||
7d88962e | 3300 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3301 | { |
7d88962e SB |
3302 | int ret = 0; |
3303 | ||
0793a61d | 3304 | /* |
cdd6c482 IM |
3305 | * If event is enabled and currently active on a CPU, update the |
3306 | * value in the event structure: | |
0793a61d | 3307 | */ |
cdd6c482 | 3308 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3309 | struct perf_read_data data = { |
3310 | .event = event, | |
3311 | .group = group, | |
7d88962e | 3312 | .ret = 0, |
0492d4c5 | 3313 | }; |
cdd6c482 | 3314 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3315 | __perf_event_read, &data, 1); |
7d88962e | 3316 | ret = data.ret; |
cdd6c482 | 3317 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3318 | struct perf_event_context *ctx = event->ctx; |
3319 | unsigned long flags; | |
3320 | ||
e625cce1 | 3321 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3322 | /* |
3323 | * may read while context is not active | |
3324 | * (e.g., thread is blocked), in that case | |
3325 | * we cannot update context time | |
3326 | */ | |
e5d1367f | 3327 | if (ctx->is_active) { |
c530ccd9 | 3328 | update_context_time(ctx); |
e5d1367f SE |
3329 | update_cgrp_time_from_event(event); |
3330 | } | |
0492d4c5 PZ |
3331 | if (group) |
3332 | update_group_times(event); | |
3333 | else | |
3334 | update_event_times(event); | |
e625cce1 | 3335 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3336 | } |
7d88962e SB |
3337 | |
3338 | return ret; | |
0793a61d TG |
3339 | } |
3340 | ||
a63eaf34 | 3341 | /* |
cdd6c482 | 3342 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3343 | */ |
eb184479 | 3344 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3345 | { |
e625cce1 | 3346 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3347 | mutex_init(&ctx->mutex); |
2fde4f94 | 3348 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3349 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3350 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3351 | INIT_LIST_HEAD(&ctx->event_list); |
3352 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3353 | } |
3354 | ||
3355 | static struct perf_event_context * | |
3356 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3357 | { | |
3358 | struct perf_event_context *ctx; | |
3359 | ||
3360 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3361 | if (!ctx) | |
3362 | return NULL; | |
3363 | ||
3364 | __perf_event_init_context(ctx); | |
3365 | if (task) { | |
3366 | ctx->task = task; | |
3367 | get_task_struct(task); | |
0793a61d | 3368 | } |
eb184479 PZ |
3369 | ctx->pmu = pmu; |
3370 | ||
3371 | return ctx; | |
a63eaf34 PM |
3372 | } |
3373 | ||
2ebd4ffb MH |
3374 | static struct task_struct * |
3375 | find_lively_task_by_vpid(pid_t vpid) | |
3376 | { | |
3377 | struct task_struct *task; | |
3378 | int err; | |
0793a61d TG |
3379 | |
3380 | rcu_read_lock(); | |
2ebd4ffb | 3381 | if (!vpid) |
0793a61d TG |
3382 | task = current; |
3383 | else | |
2ebd4ffb | 3384 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3385 | if (task) |
3386 | get_task_struct(task); | |
3387 | rcu_read_unlock(); | |
3388 | ||
3389 | if (!task) | |
3390 | return ERR_PTR(-ESRCH); | |
3391 | ||
0793a61d | 3392 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3393 | err = -EACCES; |
caaee623 | 3394 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3395 | goto errout; |
3396 | ||
2ebd4ffb MH |
3397 | return task; |
3398 | errout: | |
3399 | put_task_struct(task); | |
3400 | return ERR_PTR(err); | |
3401 | ||
3402 | } | |
3403 | ||
fe4b04fa PZ |
3404 | /* |
3405 | * Returns a matching context with refcount and pincount. | |
3406 | */ | |
108b02cf | 3407 | static struct perf_event_context * |
4af57ef2 YZ |
3408 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3409 | struct perf_event *event) | |
0793a61d | 3410 | { |
211de6eb | 3411 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3412 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3413 | void *task_ctx_data = NULL; |
25346b93 | 3414 | unsigned long flags; |
8dc85d54 | 3415 | int ctxn, err; |
4af57ef2 | 3416 | int cpu = event->cpu; |
0793a61d | 3417 | |
22a4ec72 | 3418 | if (!task) { |
cdd6c482 | 3419 | /* Must be root to operate on a CPU event: */ |
0764771d | 3420 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3421 | return ERR_PTR(-EACCES); |
3422 | ||
0793a61d | 3423 | /* |
cdd6c482 | 3424 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3425 | * offline CPU and activate it when the CPU comes up, but |
3426 | * that's for later. | |
3427 | */ | |
f6325e30 | 3428 | if (!cpu_online(cpu)) |
0793a61d TG |
3429 | return ERR_PTR(-ENODEV); |
3430 | ||
108b02cf | 3431 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3432 | ctx = &cpuctx->ctx; |
c93f7669 | 3433 | get_ctx(ctx); |
fe4b04fa | 3434 | ++ctx->pin_count; |
0793a61d | 3435 | |
0793a61d TG |
3436 | return ctx; |
3437 | } | |
3438 | ||
8dc85d54 PZ |
3439 | err = -EINVAL; |
3440 | ctxn = pmu->task_ctx_nr; | |
3441 | if (ctxn < 0) | |
3442 | goto errout; | |
3443 | ||
4af57ef2 YZ |
3444 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3445 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3446 | if (!task_ctx_data) { | |
3447 | err = -ENOMEM; | |
3448 | goto errout; | |
3449 | } | |
3450 | } | |
3451 | ||
9ed6060d | 3452 | retry: |
8dc85d54 | 3453 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3454 | if (ctx) { |
211de6eb | 3455 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3456 | ++ctx->pin_count; |
4af57ef2 YZ |
3457 | |
3458 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3459 | ctx->task_ctx_data = task_ctx_data; | |
3460 | task_ctx_data = NULL; | |
3461 | } | |
e625cce1 | 3462 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3463 | |
3464 | if (clone_ctx) | |
3465 | put_ctx(clone_ctx); | |
9137fb28 | 3466 | } else { |
eb184479 | 3467 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3468 | err = -ENOMEM; |
3469 | if (!ctx) | |
3470 | goto errout; | |
eb184479 | 3471 | |
4af57ef2 YZ |
3472 | if (task_ctx_data) { |
3473 | ctx->task_ctx_data = task_ctx_data; | |
3474 | task_ctx_data = NULL; | |
3475 | } | |
3476 | ||
dbe08d82 ON |
3477 | err = 0; |
3478 | mutex_lock(&task->perf_event_mutex); | |
3479 | /* | |
3480 | * If it has already passed perf_event_exit_task(). | |
3481 | * we must see PF_EXITING, it takes this mutex too. | |
3482 | */ | |
3483 | if (task->flags & PF_EXITING) | |
3484 | err = -ESRCH; | |
3485 | else if (task->perf_event_ctxp[ctxn]) | |
3486 | err = -EAGAIN; | |
fe4b04fa | 3487 | else { |
9137fb28 | 3488 | get_ctx(ctx); |
fe4b04fa | 3489 | ++ctx->pin_count; |
dbe08d82 | 3490 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3491 | } |
dbe08d82 ON |
3492 | mutex_unlock(&task->perf_event_mutex); |
3493 | ||
3494 | if (unlikely(err)) { | |
9137fb28 | 3495 | put_ctx(ctx); |
dbe08d82 ON |
3496 | |
3497 | if (err == -EAGAIN) | |
3498 | goto retry; | |
3499 | goto errout; | |
a63eaf34 PM |
3500 | } |
3501 | } | |
3502 | ||
4af57ef2 | 3503 | kfree(task_ctx_data); |
0793a61d | 3504 | return ctx; |
c93f7669 | 3505 | |
9ed6060d | 3506 | errout: |
4af57ef2 | 3507 | kfree(task_ctx_data); |
c93f7669 | 3508 | return ERR_PTR(err); |
0793a61d TG |
3509 | } |
3510 | ||
6fb2915d | 3511 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3512 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3513 | |
cdd6c482 | 3514 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3515 | { |
cdd6c482 | 3516 | struct perf_event *event; |
592903cd | 3517 | |
cdd6c482 IM |
3518 | event = container_of(head, struct perf_event, rcu_head); |
3519 | if (event->ns) | |
3520 | put_pid_ns(event->ns); | |
6fb2915d | 3521 | perf_event_free_filter(event); |
cdd6c482 | 3522 | kfree(event); |
592903cd PZ |
3523 | } |
3524 | ||
b69cf536 PZ |
3525 | static void ring_buffer_attach(struct perf_event *event, |
3526 | struct ring_buffer *rb); | |
925d519a | 3527 | |
4beb31f3 | 3528 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3529 | { |
4beb31f3 FW |
3530 | if (event->parent) |
3531 | return; | |
3532 | ||
4beb31f3 FW |
3533 | if (is_cgroup_event(event)) |
3534 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3535 | } | |
925d519a | 3536 | |
4beb31f3 FW |
3537 | static void unaccount_event(struct perf_event *event) |
3538 | { | |
25432ae9 PZ |
3539 | bool dec = false; |
3540 | ||
4beb31f3 FW |
3541 | if (event->parent) |
3542 | return; | |
3543 | ||
3544 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3545 | dec = true; |
4beb31f3 FW |
3546 | if (event->attr.mmap || event->attr.mmap_data) |
3547 | atomic_dec(&nr_mmap_events); | |
3548 | if (event->attr.comm) | |
3549 | atomic_dec(&nr_comm_events); | |
3550 | if (event->attr.task) | |
3551 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3552 | if (event->attr.freq) |
3553 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3554 | if (event->attr.context_switch) { |
25432ae9 | 3555 | dec = true; |
45ac1403 AH |
3556 | atomic_dec(&nr_switch_events); |
3557 | } | |
4beb31f3 | 3558 | if (is_cgroup_event(event)) |
25432ae9 | 3559 | dec = true; |
4beb31f3 | 3560 | if (has_branch_stack(event)) |
25432ae9 PZ |
3561 | dec = true; |
3562 | ||
9107c89e PZ |
3563 | if (dec) { |
3564 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
3565 | schedule_delayed_work(&perf_sched_work, HZ); | |
3566 | } | |
4beb31f3 FW |
3567 | |
3568 | unaccount_event_cpu(event, event->cpu); | |
3569 | } | |
925d519a | 3570 | |
9107c89e PZ |
3571 | static void perf_sched_delayed(struct work_struct *work) |
3572 | { | |
3573 | mutex_lock(&perf_sched_mutex); | |
3574 | if (atomic_dec_and_test(&perf_sched_count)) | |
3575 | static_branch_disable(&perf_sched_events); | |
3576 | mutex_unlock(&perf_sched_mutex); | |
3577 | } | |
3578 | ||
bed5b25a AS |
3579 | /* |
3580 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3581 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3582 | * at a time, so we disallow creating events that might conflict, namely: | |
3583 | * | |
3584 | * 1) cpu-wide events in the presence of per-task events, | |
3585 | * 2) per-task events in the presence of cpu-wide events, | |
3586 | * 3) two matching events on the same context. | |
3587 | * | |
3588 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3589 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3590 | */ |
3591 | static int exclusive_event_init(struct perf_event *event) | |
3592 | { | |
3593 | struct pmu *pmu = event->pmu; | |
3594 | ||
3595 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3596 | return 0; | |
3597 | ||
3598 | /* | |
3599 | * Prevent co-existence of per-task and cpu-wide events on the | |
3600 | * same exclusive pmu. | |
3601 | * | |
3602 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3603 | * events on this "exclusive" pmu, positive means there are | |
3604 | * per-task events. | |
3605 | * | |
3606 | * Since this is called in perf_event_alloc() path, event::ctx | |
3607 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3608 | * to mean "per-task event", because unlike other attach states it | |
3609 | * never gets cleared. | |
3610 | */ | |
3611 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3612 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3613 | return -EBUSY; | |
3614 | } else { | |
3615 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3616 | return -EBUSY; | |
3617 | } | |
3618 | ||
3619 | return 0; | |
3620 | } | |
3621 | ||
3622 | static void exclusive_event_destroy(struct perf_event *event) | |
3623 | { | |
3624 | struct pmu *pmu = event->pmu; | |
3625 | ||
3626 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3627 | return; | |
3628 | ||
3629 | /* see comment in exclusive_event_init() */ | |
3630 | if (event->attach_state & PERF_ATTACH_TASK) | |
3631 | atomic_dec(&pmu->exclusive_cnt); | |
3632 | else | |
3633 | atomic_inc(&pmu->exclusive_cnt); | |
3634 | } | |
3635 | ||
3636 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3637 | { | |
3638 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3639 | (e1->cpu == e2->cpu || | |
3640 | e1->cpu == -1 || | |
3641 | e2->cpu == -1)) | |
3642 | return true; | |
3643 | return false; | |
3644 | } | |
3645 | ||
3646 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3647 | static bool exclusive_event_installable(struct perf_event *event, | |
3648 | struct perf_event_context *ctx) | |
3649 | { | |
3650 | struct perf_event *iter_event; | |
3651 | struct pmu *pmu = event->pmu; | |
3652 | ||
3653 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3654 | return true; | |
3655 | ||
3656 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3657 | if (exclusive_event_match(iter_event, event)) | |
3658 | return false; | |
3659 | } | |
3660 | ||
3661 | return true; | |
3662 | } | |
3663 | ||
683ede43 | 3664 | static void _free_event(struct perf_event *event) |
f1600952 | 3665 | { |
e360adbe | 3666 | irq_work_sync(&event->pending); |
925d519a | 3667 | |
4beb31f3 | 3668 | unaccount_event(event); |
9ee318a7 | 3669 | |
76369139 | 3670 | if (event->rb) { |
9bb5d40c PZ |
3671 | /* |
3672 | * Can happen when we close an event with re-directed output. | |
3673 | * | |
3674 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3675 | * over us; possibly making our ring_buffer_put() the last. | |
3676 | */ | |
3677 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3678 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3679 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3680 | } |
3681 | ||
e5d1367f SE |
3682 | if (is_cgroup_event(event)) |
3683 | perf_detach_cgroup(event); | |
3684 | ||
a0733e69 PZ |
3685 | if (!event->parent) { |
3686 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3687 | put_callchain_buffers(); | |
3688 | } | |
3689 | ||
3690 | perf_event_free_bpf_prog(event); | |
3691 | ||
3692 | if (event->destroy) | |
3693 | event->destroy(event); | |
3694 | ||
3695 | if (event->ctx) | |
3696 | put_ctx(event->ctx); | |
3697 | ||
3698 | if (event->pmu) { | |
3699 | exclusive_event_destroy(event); | |
3700 | module_put(event->pmu->module); | |
3701 | } | |
3702 | ||
3703 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3704 | } |
3705 | ||
683ede43 PZ |
3706 | /* |
3707 | * Used to free events which have a known refcount of 1, such as in error paths | |
3708 | * where the event isn't exposed yet and inherited events. | |
3709 | */ | |
3710 | static void free_event(struct perf_event *event) | |
0793a61d | 3711 | { |
683ede43 PZ |
3712 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3713 | "unexpected event refcount: %ld; ptr=%p\n", | |
3714 | atomic_long_read(&event->refcount), event)) { | |
3715 | /* leak to avoid use-after-free */ | |
3716 | return; | |
3717 | } | |
0793a61d | 3718 | |
683ede43 | 3719 | _free_event(event); |
0793a61d TG |
3720 | } |
3721 | ||
a66a3052 | 3722 | /* |
f8697762 | 3723 | * Remove user event from the owner task. |
a66a3052 | 3724 | */ |
f8697762 | 3725 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3726 | { |
8882135b | 3727 | struct task_struct *owner; |
fb0459d7 | 3728 | |
8882135b | 3729 | rcu_read_lock(); |
8882135b | 3730 | /* |
f47c02c0 PZ |
3731 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3732 | * observe !owner it means the list deletion is complete and we can | |
3733 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3734 | * owner->perf_event_mutex. |
3735 | */ | |
f47c02c0 | 3736 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3737 | if (owner) { |
3738 | /* | |
3739 | * Since delayed_put_task_struct() also drops the last | |
3740 | * task reference we can safely take a new reference | |
3741 | * while holding the rcu_read_lock(). | |
3742 | */ | |
3743 | get_task_struct(owner); | |
3744 | } | |
3745 | rcu_read_unlock(); | |
3746 | ||
3747 | if (owner) { | |
f63a8daa PZ |
3748 | /* |
3749 | * If we're here through perf_event_exit_task() we're already | |
3750 | * holding ctx->mutex which would be an inversion wrt. the | |
3751 | * normal lock order. | |
3752 | * | |
3753 | * However we can safely take this lock because its the child | |
3754 | * ctx->mutex. | |
3755 | */ | |
3756 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3757 | ||
8882135b PZ |
3758 | /* |
3759 | * We have to re-check the event->owner field, if it is cleared | |
3760 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3761 | * ensured they're done, and we can proceed with freeing the | |
3762 | * event. | |
3763 | */ | |
f47c02c0 | 3764 | if (event->owner) { |
8882135b | 3765 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3766 | smp_store_release(&event->owner, NULL); |
3767 | } | |
8882135b PZ |
3768 | mutex_unlock(&owner->perf_event_mutex); |
3769 | put_task_struct(owner); | |
3770 | } | |
f8697762 JO |
3771 | } |
3772 | ||
f8697762 JO |
3773 | static void put_event(struct perf_event *event) |
3774 | { | |
f8697762 JO |
3775 | if (!atomic_long_dec_and_test(&event->refcount)) |
3776 | return; | |
3777 | ||
c6e5b732 PZ |
3778 | _free_event(event); |
3779 | } | |
3780 | ||
3781 | /* | |
3782 | * Kill an event dead; while event:refcount will preserve the event | |
3783 | * object, it will not preserve its functionality. Once the last 'user' | |
3784 | * gives up the object, we'll destroy the thing. | |
3785 | */ | |
3786 | int perf_event_release_kernel(struct perf_event *event) | |
3787 | { | |
a4f4bb6d | 3788 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
3789 | struct perf_event *child, *tmp; |
3790 | ||
a4f4bb6d PZ |
3791 | /* |
3792 | * If we got here through err_file: fput(event_file); we will not have | |
3793 | * attached to a context yet. | |
3794 | */ | |
3795 | if (!ctx) { | |
3796 | WARN_ON_ONCE(event->attach_state & | |
3797 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
3798 | goto no_ctx; | |
3799 | } | |
3800 | ||
f8697762 JO |
3801 | if (!is_kernel_event(event)) |
3802 | perf_remove_from_owner(event); | |
8882135b | 3803 | |
5fa7c8ec | 3804 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3805 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 3806 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 3807 | |
a69b0ca4 | 3808 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 3809 | /* |
a69b0ca4 PZ |
3810 | * Mark this even as STATE_DEAD, there is no external reference to it |
3811 | * anymore. | |
683ede43 | 3812 | * |
a69b0ca4 PZ |
3813 | * Anybody acquiring event->child_mutex after the below loop _must_ |
3814 | * also see this, most importantly inherit_event() which will avoid | |
3815 | * placing more children on the list. | |
683ede43 | 3816 | * |
c6e5b732 PZ |
3817 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3818 | * child events. | |
683ede43 | 3819 | */ |
a69b0ca4 PZ |
3820 | event->state = PERF_EVENT_STATE_DEAD; |
3821 | raw_spin_unlock_irq(&ctx->lock); | |
3822 | ||
3823 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 3824 | |
c6e5b732 PZ |
3825 | again: |
3826 | mutex_lock(&event->child_mutex); | |
3827 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3828 | |
c6e5b732 PZ |
3829 | /* |
3830 | * Cannot change, child events are not migrated, see the | |
3831 | * comment with perf_event_ctx_lock_nested(). | |
3832 | */ | |
3833 | ctx = lockless_dereference(child->ctx); | |
3834 | /* | |
3835 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3836 | * through hoops. We start by grabbing a reference on the ctx. | |
3837 | * | |
3838 | * Since the event cannot get freed while we hold the | |
3839 | * child_mutex, the context must also exist and have a !0 | |
3840 | * reference count. | |
3841 | */ | |
3842 | get_ctx(ctx); | |
3843 | ||
3844 | /* | |
3845 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3846 | * acquire ctx::mutex without fear of it going away. Then we | |
3847 | * can re-acquire child_mutex. | |
3848 | */ | |
3849 | mutex_unlock(&event->child_mutex); | |
3850 | mutex_lock(&ctx->mutex); | |
3851 | mutex_lock(&event->child_mutex); | |
3852 | ||
3853 | /* | |
3854 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3855 | * state, if child is still the first entry, it didn't get freed | |
3856 | * and we can continue doing so. | |
3857 | */ | |
3858 | tmp = list_first_entry_or_null(&event->child_list, | |
3859 | struct perf_event, child_list); | |
3860 | if (tmp == child) { | |
3861 | perf_remove_from_context(child, DETACH_GROUP); | |
3862 | list_del(&child->child_list); | |
3863 | free_event(child); | |
3864 | /* | |
3865 | * This matches the refcount bump in inherit_event(); | |
3866 | * this can't be the last reference. | |
3867 | */ | |
3868 | put_event(event); | |
3869 | } | |
3870 | ||
3871 | mutex_unlock(&event->child_mutex); | |
3872 | mutex_unlock(&ctx->mutex); | |
3873 | put_ctx(ctx); | |
3874 | goto again; | |
3875 | } | |
3876 | mutex_unlock(&event->child_mutex); | |
3877 | ||
a4f4bb6d PZ |
3878 | no_ctx: |
3879 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
3880 | return 0; |
3881 | } | |
3882 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3883 | ||
8b10c5e2 PZ |
3884 | /* |
3885 | * Called when the last reference to the file is gone. | |
3886 | */ | |
a6fa941d AV |
3887 | static int perf_release(struct inode *inode, struct file *file) |
3888 | { | |
c6e5b732 | 3889 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3890 | return 0; |
fb0459d7 | 3891 | } |
fb0459d7 | 3892 | |
59ed446f | 3893 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3894 | { |
cdd6c482 | 3895 | struct perf_event *child; |
e53c0994 PZ |
3896 | u64 total = 0; |
3897 | ||
59ed446f PZ |
3898 | *enabled = 0; |
3899 | *running = 0; | |
3900 | ||
6f10581a | 3901 | mutex_lock(&event->child_mutex); |
01add3ea | 3902 | |
7d88962e | 3903 | (void)perf_event_read(event, false); |
01add3ea SB |
3904 | total += perf_event_count(event); |
3905 | ||
59ed446f PZ |
3906 | *enabled += event->total_time_enabled + |
3907 | atomic64_read(&event->child_total_time_enabled); | |
3908 | *running += event->total_time_running + | |
3909 | atomic64_read(&event->child_total_time_running); | |
3910 | ||
3911 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3912 | (void)perf_event_read(child, false); |
01add3ea | 3913 | total += perf_event_count(child); |
59ed446f PZ |
3914 | *enabled += child->total_time_enabled; |
3915 | *running += child->total_time_running; | |
3916 | } | |
6f10581a | 3917 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3918 | |
3919 | return total; | |
3920 | } | |
fb0459d7 | 3921 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3922 | |
7d88962e | 3923 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3924 | u64 read_format, u64 *values) |
3dab77fb | 3925 | { |
fa8c2693 PZ |
3926 | struct perf_event *sub; |
3927 | int n = 1; /* skip @nr */ | |
7d88962e | 3928 | int ret; |
f63a8daa | 3929 | |
7d88962e SB |
3930 | ret = perf_event_read(leader, true); |
3931 | if (ret) | |
3932 | return ret; | |
abf4868b | 3933 | |
fa8c2693 PZ |
3934 | /* |
3935 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3936 | * will be identical to those of the leader, so we only publish one | |
3937 | * set. | |
3938 | */ | |
3939 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3940 | values[n++] += leader->total_time_enabled + | |
3941 | atomic64_read(&leader->child_total_time_enabled); | |
3942 | } | |
3dab77fb | 3943 | |
fa8c2693 PZ |
3944 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3945 | values[n++] += leader->total_time_running + | |
3946 | atomic64_read(&leader->child_total_time_running); | |
3947 | } | |
3948 | ||
3949 | /* | |
3950 | * Write {count,id} tuples for every sibling. | |
3951 | */ | |
3952 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3953 | if (read_format & PERF_FORMAT_ID) |
3954 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3955 | |
fa8c2693 PZ |
3956 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3957 | values[n++] += perf_event_count(sub); | |
3958 | if (read_format & PERF_FORMAT_ID) | |
3959 | values[n++] = primary_event_id(sub); | |
3960 | } | |
7d88962e SB |
3961 | |
3962 | return 0; | |
fa8c2693 | 3963 | } |
3dab77fb | 3964 | |
fa8c2693 PZ |
3965 | static int perf_read_group(struct perf_event *event, |
3966 | u64 read_format, char __user *buf) | |
3967 | { | |
3968 | struct perf_event *leader = event->group_leader, *child; | |
3969 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3970 | int ret; |
fa8c2693 | 3971 | u64 *values; |
3dab77fb | 3972 | |
fa8c2693 | 3973 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3974 | |
fa8c2693 PZ |
3975 | values = kzalloc(event->read_size, GFP_KERNEL); |
3976 | if (!values) | |
3977 | return -ENOMEM; | |
3dab77fb | 3978 | |
fa8c2693 PZ |
3979 | values[0] = 1 + leader->nr_siblings; |
3980 | ||
3981 | /* | |
3982 | * By locking the child_mutex of the leader we effectively | |
3983 | * lock the child list of all siblings.. XXX explain how. | |
3984 | */ | |
3985 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3986 | |
7d88962e SB |
3987 | ret = __perf_read_group_add(leader, read_format, values); |
3988 | if (ret) | |
3989 | goto unlock; | |
3990 | ||
3991 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3992 | ret = __perf_read_group_add(child, read_format, values); | |
3993 | if (ret) | |
3994 | goto unlock; | |
3995 | } | |
abf4868b | 3996 | |
fa8c2693 | 3997 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3998 | |
7d88962e | 3999 | ret = event->read_size; |
fa8c2693 PZ |
4000 | if (copy_to_user(buf, values, event->read_size)) |
4001 | ret = -EFAULT; | |
7d88962e | 4002 | goto out; |
fa8c2693 | 4003 | |
7d88962e SB |
4004 | unlock: |
4005 | mutex_unlock(&leader->child_mutex); | |
4006 | out: | |
fa8c2693 | 4007 | kfree(values); |
abf4868b | 4008 | return ret; |
3dab77fb PZ |
4009 | } |
4010 | ||
b15f495b | 4011 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4012 | u64 read_format, char __user *buf) |
4013 | { | |
59ed446f | 4014 | u64 enabled, running; |
3dab77fb PZ |
4015 | u64 values[4]; |
4016 | int n = 0; | |
4017 | ||
59ed446f PZ |
4018 | values[n++] = perf_event_read_value(event, &enabled, &running); |
4019 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4020 | values[n++] = enabled; | |
4021 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4022 | values[n++] = running; | |
3dab77fb | 4023 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4024 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4025 | |
4026 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4027 | return -EFAULT; | |
4028 | ||
4029 | return n * sizeof(u64); | |
4030 | } | |
4031 | ||
dc633982 JO |
4032 | static bool is_event_hup(struct perf_event *event) |
4033 | { | |
4034 | bool no_children; | |
4035 | ||
a69b0ca4 | 4036 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4037 | return false; |
4038 | ||
4039 | mutex_lock(&event->child_mutex); | |
4040 | no_children = list_empty(&event->child_list); | |
4041 | mutex_unlock(&event->child_mutex); | |
4042 | return no_children; | |
4043 | } | |
4044 | ||
0793a61d | 4045 | /* |
cdd6c482 | 4046 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4047 | */ |
4048 | static ssize_t | |
b15f495b | 4049 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4050 | { |
cdd6c482 | 4051 | u64 read_format = event->attr.read_format; |
3dab77fb | 4052 | int ret; |
0793a61d | 4053 | |
3b6f9e5c | 4054 | /* |
cdd6c482 | 4055 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4056 | * error state (i.e. because it was pinned but it couldn't be |
4057 | * scheduled on to the CPU at some point). | |
4058 | */ | |
cdd6c482 | 4059 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4060 | return 0; |
4061 | ||
c320c7b7 | 4062 | if (count < event->read_size) |
3dab77fb PZ |
4063 | return -ENOSPC; |
4064 | ||
cdd6c482 | 4065 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4066 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4067 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4068 | else |
b15f495b | 4069 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4070 | |
3dab77fb | 4071 | return ret; |
0793a61d TG |
4072 | } |
4073 | ||
0793a61d TG |
4074 | static ssize_t |
4075 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4076 | { | |
cdd6c482 | 4077 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4078 | struct perf_event_context *ctx; |
4079 | int ret; | |
0793a61d | 4080 | |
f63a8daa | 4081 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4082 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4083 | perf_event_ctx_unlock(event, ctx); |
4084 | ||
4085 | return ret; | |
0793a61d TG |
4086 | } |
4087 | ||
4088 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4089 | { | |
cdd6c482 | 4090 | struct perf_event *event = file->private_data; |
76369139 | 4091 | struct ring_buffer *rb; |
61b67684 | 4092 | unsigned int events = POLLHUP; |
c7138f37 | 4093 | |
e708d7ad | 4094 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4095 | |
dc633982 | 4096 | if (is_event_hup(event)) |
179033b3 | 4097 | return events; |
c7138f37 | 4098 | |
10c6db11 | 4099 | /* |
9bb5d40c PZ |
4100 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4101 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4102 | */ |
4103 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4104 | rb = event->rb; |
4105 | if (rb) | |
76369139 | 4106 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4107 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4108 | return events; |
4109 | } | |
4110 | ||
f63a8daa | 4111 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4112 | { |
7d88962e | 4113 | (void)perf_event_read(event, false); |
e7850595 | 4114 | local64_set(&event->count, 0); |
cdd6c482 | 4115 | perf_event_update_userpage(event); |
3df5edad PZ |
4116 | } |
4117 | ||
c93f7669 | 4118 | /* |
cdd6c482 IM |
4119 | * Holding the top-level event's child_mutex means that any |
4120 | * descendant process that has inherited this event will block | |
8ba289b8 | 4121 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4122 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4123 | */ |
cdd6c482 IM |
4124 | static void perf_event_for_each_child(struct perf_event *event, |
4125 | void (*func)(struct perf_event *)) | |
3df5edad | 4126 | { |
cdd6c482 | 4127 | struct perf_event *child; |
3df5edad | 4128 | |
cdd6c482 | 4129 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4130 | |
cdd6c482 IM |
4131 | mutex_lock(&event->child_mutex); |
4132 | func(event); | |
4133 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4134 | func(child); |
cdd6c482 | 4135 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4136 | } |
4137 | ||
cdd6c482 IM |
4138 | static void perf_event_for_each(struct perf_event *event, |
4139 | void (*func)(struct perf_event *)) | |
3df5edad | 4140 | { |
cdd6c482 IM |
4141 | struct perf_event_context *ctx = event->ctx; |
4142 | struct perf_event *sibling; | |
3df5edad | 4143 | |
f63a8daa PZ |
4144 | lockdep_assert_held(&ctx->mutex); |
4145 | ||
cdd6c482 | 4146 | event = event->group_leader; |
75f937f2 | 4147 | |
cdd6c482 | 4148 | perf_event_for_each_child(event, func); |
cdd6c482 | 4149 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4150 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4151 | } |
4152 | ||
fae3fde6 PZ |
4153 | static void __perf_event_period(struct perf_event *event, |
4154 | struct perf_cpu_context *cpuctx, | |
4155 | struct perf_event_context *ctx, | |
4156 | void *info) | |
c7999c6f | 4157 | { |
fae3fde6 | 4158 | u64 value = *((u64 *)info); |
c7999c6f | 4159 | bool active; |
08247e31 | 4160 | |
cdd6c482 | 4161 | if (event->attr.freq) { |
cdd6c482 | 4162 | event->attr.sample_freq = value; |
08247e31 | 4163 | } else { |
cdd6c482 IM |
4164 | event->attr.sample_period = value; |
4165 | event->hw.sample_period = value; | |
08247e31 | 4166 | } |
bad7192b PZ |
4167 | |
4168 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4169 | if (active) { | |
4170 | perf_pmu_disable(ctx->pmu); | |
4171 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4172 | } | |
4173 | ||
4174 | local64_set(&event->hw.period_left, 0); | |
4175 | ||
4176 | if (active) { | |
4177 | event->pmu->start(event, PERF_EF_RELOAD); | |
4178 | perf_pmu_enable(ctx->pmu); | |
4179 | } | |
c7999c6f PZ |
4180 | } |
4181 | ||
4182 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4183 | { | |
c7999c6f PZ |
4184 | u64 value; |
4185 | ||
4186 | if (!is_sampling_event(event)) | |
4187 | return -EINVAL; | |
4188 | ||
4189 | if (copy_from_user(&value, arg, sizeof(value))) | |
4190 | return -EFAULT; | |
4191 | ||
4192 | if (!value) | |
4193 | return -EINVAL; | |
4194 | ||
4195 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4196 | return -EINVAL; | |
4197 | ||
fae3fde6 | 4198 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4199 | |
c7999c6f | 4200 | return 0; |
08247e31 PZ |
4201 | } |
4202 | ||
ac9721f3 PZ |
4203 | static const struct file_operations perf_fops; |
4204 | ||
2903ff01 | 4205 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4206 | { |
2903ff01 AV |
4207 | struct fd f = fdget(fd); |
4208 | if (!f.file) | |
4209 | return -EBADF; | |
ac9721f3 | 4210 | |
2903ff01 AV |
4211 | if (f.file->f_op != &perf_fops) { |
4212 | fdput(f); | |
4213 | return -EBADF; | |
ac9721f3 | 4214 | } |
2903ff01 AV |
4215 | *p = f; |
4216 | return 0; | |
ac9721f3 PZ |
4217 | } |
4218 | ||
4219 | static int perf_event_set_output(struct perf_event *event, | |
4220 | struct perf_event *output_event); | |
6fb2915d | 4221 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4222 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4223 | |
f63a8daa | 4224 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4225 | { |
cdd6c482 | 4226 | void (*func)(struct perf_event *); |
3df5edad | 4227 | u32 flags = arg; |
d859e29f PM |
4228 | |
4229 | switch (cmd) { | |
cdd6c482 | 4230 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4231 | func = _perf_event_enable; |
d859e29f | 4232 | break; |
cdd6c482 | 4233 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4234 | func = _perf_event_disable; |
79f14641 | 4235 | break; |
cdd6c482 | 4236 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4237 | func = _perf_event_reset; |
6de6a7b9 | 4238 | break; |
3df5edad | 4239 | |
cdd6c482 | 4240 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4241 | return _perf_event_refresh(event, arg); |
08247e31 | 4242 | |
cdd6c482 IM |
4243 | case PERF_EVENT_IOC_PERIOD: |
4244 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4245 | |
cf4957f1 JO |
4246 | case PERF_EVENT_IOC_ID: |
4247 | { | |
4248 | u64 id = primary_event_id(event); | |
4249 | ||
4250 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4251 | return -EFAULT; | |
4252 | return 0; | |
4253 | } | |
4254 | ||
cdd6c482 | 4255 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4256 | { |
ac9721f3 | 4257 | int ret; |
ac9721f3 | 4258 | if (arg != -1) { |
2903ff01 AV |
4259 | struct perf_event *output_event; |
4260 | struct fd output; | |
4261 | ret = perf_fget_light(arg, &output); | |
4262 | if (ret) | |
4263 | return ret; | |
4264 | output_event = output.file->private_data; | |
4265 | ret = perf_event_set_output(event, output_event); | |
4266 | fdput(output); | |
4267 | } else { | |
4268 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4269 | } |
ac9721f3 PZ |
4270 | return ret; |
4271 | } | |
a4be7c27 | 4272 | |
6fb2915d LZ |
4273 | case PERF_EVENT_IOC_SET_FILTER: |
4274 | return perf_event_set_filter(event, (void __user *)arg); | |
4275 | ||
2541517c AS |
4276 | case PERF_EVENT_IOC_SET_BPF: |
4277 | return perf_event_set_bpf_prog(event, arg); | |
4278 | ||
d859e29f | 4279 | default: |
3df5edad | 4280 | return -ENOTTY; |
d859e29f | 4281 | } |
3df5edad PZ |
4282 | |
4283 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4284 | perf_event_for_each(event, func); |
3df5edad | 4285 | else |
cdd6c482 | 4286 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4287 | |
4288 | return 0; | |
d859e29f PM |
4289 | } |
4290 | ||
f63a8daa PZ |
4291 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4292 | { | |
4293 | struct perf_event *event = file->private_data; | |
4294 | struct perf_event_context *ctx; | |
4295 | long ret; | |
4296 | ||
4297 | ctx = perf_event_ctx_lock(event); | |
4298 | ret = _perf_ioctl(event, cmd, arg); | |
4299 | perf_event_ctx_unlock(event, ctx); | |
4300 | ||
4301 | return ret; | |
4302 | } | |
4303 | ||
b3f20785 PM |
4304 | #ifdef CONFIG_COMPAT |
4305 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4306 | unsigned long arg) | |
4307 | { | |
4308 | switch (_IOC_NR(cmd)) { | |
4309 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4310 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4311 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4312 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4313 | cmd &= ~IOCSIZE_MASK; | |
4314 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4315 | } | |
4316 | break; | |
4317 | } | |
4318 | return perf_ioctl(file, cmd, arg); | |
4319 | } | |
4320 | #else | |
4321 | # define perf_compat_ioctl NULL | |
4322 | #endif | |
4323 | ||
cdd6c482 | 4324 | int perf_event_task_enable(void) |
771d7cde | 4325 | { |
f63a8daa | 4326 | struct perf_event_context *ctx; |
cdd6c482 | 4327 | struct perf_event *event; |
771d7cde | 4328 | |
cdd6c482 | 4329 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4330 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4331 | ctx = perf_event_ctx_lock(event); | |
4332 | perf_event_for_each_child(event, _perf_event_enable); | |
4333 | perf_event_ctx_unlock(event, ctx); | |
4334 | } | |
cdd6c482 | 4335 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4336 | |
4337 | return 0; | |
4338 | } | |
4339 | ||
cdd6c482 | 4340 | int perf_event_task_disable(void) |
771d7cde | 4341 | { |
f63a8daa | 4342 | struct perf_event_context *ctx; |
cdd6c482 | 4343 | struct perf_event *event; |
771d7cde | 4344 | |
cdd6c482 | 4345 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4346 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4347 | ctx = perf_event_ctx_lock(event); | |
4348 | perf_event_for_each_child(event, _perf_event_disable); | |
4349 | perf_event_ctx_unlock(event, ctx); | |
4350 | } | |
cdd6c482 | 4351 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4352 | |
4353 | return 0; | |
4354 | } | |
4355 | ||
cdd6c482 | 4356 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4357 | { |
a4eaf7f1 PZ |
4358 | if (event->hw.state & PERF_HES_STOPPED) |
4359 | return 0; | |
4360 | ||
cdd6c482 | 4361 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4362 | return 0; |
4363 | ||
35edc2a5 | 4364 | return event->pmu->event_idx(event); |
194002b2 PZ |
4365 | } |
4366 | ||
c4794295 | 4367 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4368 | u64 *now, |
7f310a5d EM |
4369 | u64 *enabled, |
4370 | u64 *running) | |
c4794295 | 4371 | { |
e3f3541c | 4372 | u64 ctx_time; |
c4794295 | 4373 | |
e3f3541c PZ |
4374 | *now = perf_clock(); |
4375 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4376 | *enabled = ctx_time - event->tstamp_enabled; |
4377 | *running = ctx_time - event->tstamp_running; | |
4378 | } | |
4379 | ||
fa731587 PZ |
4380 | static void perf_event_init_userpage(struct perf_event *event) |
4381 | { | |
4382 | struct perf_event_mmap_page *userpg; | |
4383 | struct ring_buffer *rb; | |
4384 | ||
4385 | rcu_read_lock(); | |
4386 | rb = rcu_dereference(event->rb); | |
4387 | if (!rb) | |
4388 | goto unlock; | |
4389 | ||
4390 | userpg = rb->user_page; | |
4391 | ||
4392 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4393 | userpg->cap_bit0_is_deprecated = 1; | |
4394 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4395 | userpg->data_offset = PAGE_SIZE; |
4396 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4397 | |
4398 | unlock: | |
4399 | rcu_read_unlock(); | |
4400 | } | |
4401 | ||
c1317ec2 AL |
4402 | void __weak arch_perf_update_userpage( |
4403 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4404 | { |
4405 | } | |
4406 | ||
38ff667b PZ |
4407 | /* |
4408 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4409 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4410 | * code calls this from NMI context. | |
4411 | */ | |
cdd6c482 | 4412 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4413 | { |
cdd6c482 | 4414 | struct perf_event_mmap_page *userpg; |
76369139 | 4415 | struct ring_buffer *rb; |
e3f3541c | 4416 | u64 enabled, running, now; |
38ff667b PZ |
4417 | |
4418 | rcu_read_lock(); | |
5ec4c599 PZ |
4419 | rb = rcu_dereference(event->rb); |
4420 | if (!rb) | |
4421 | goto unlock; | |
4422 | ||
0d641208 EM |
4423 | /* |
4424 | * compute total_time_enabled, total_time_running | |
4425 | * based on snapshot values taken when the event | |
4426 | * was last scheduled in. | |
4427 | * | |
4428 | * we cannot simply called update_context_time() | |
4429 | * because of locking issue as we can be called in | |
4430 | * NMI context | |
4431 | */ | |
e3f3541c | 4432 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4433 | |
76369139 | 4434 | userpg = rb->user_page; |
7b732a75 PZ |
4435 | /* |
4436 | * Disable preemption so as to not let the corresponding user-space | |
4437 | * spin too long if we get preempted. | |
4438 | */ | |
4439 | preempt_disable(); | |
37d81828 | 4440 | ++userpg->lock; |
92f22a38 | 4441 | barrier(); |
cdd6c482 | 4442 | userpg->index = perf_event_index(event); |
b5e58793 | 4443 | userpg->offset = perf_event_count(event); |
365a4038 | 4444 | if (userpg->index) |
e7850595 | 4445 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4446 | |
0d641208 | 4447 | userpg->time_enabled = enabled + |
cdd6c482 | 4448 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4449 | |
0d641208 | 4450 | userpg->time_running = running + |
cdd6c482 | 4451 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4452 | |
c1317ec2 | 4453 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4454 | |
92f22a38 | 4455 | barrier(); |
37d81828 | 4456 | ++userpg->lock; |
7b732a75 | 4457 | preempt_enable(); |
38ff667b | 4458 | unlock: |
7b732a75 | 4459 | rcu_read_unlock(); |
37d81828 PM |
4460 | } |
4461 | ||
906010b2 PZ |
4462 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4463 | { | |
4464 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4465 | struct ring_buffer *rb; |
906010b2 PZ |
4466 | int ret = VM_FAULT_SIGBUS; |
4467 | ||
4468 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4469 | if (vmf->pgoff == 0) | |
4470 | ret = 0; | |
4471 | return ret; | |
4472 | } | |
4473 | ||
4474 | rcu_read_lock(); | |
76369139 FW |
4475 | rb = rcu_dereference(event->rb); |
4476 | if (!rb) | |
906010b2 PZ |
4477 | goto unlock; |
4478 | ||
4479 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4480 | goto unlock; | |
4481 | ||
76369139 | 4482 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4483 | if (!vmf->page) |
4484 | goto unlock; | |
4485 | ||
4486 | get_page(vmf->page); | |
4487 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4488 | vmf->page->index = vmf->pgoff; | |
4489 | ||
4490 | ret = 0; | |
4491 | unlock: | |
4492 | rcu_read_unlock(); | |
4493 | ||
4494 | return ret; | |
4495 | } | |
4496 | ||
10c6db11 PZ |
4497 | static void ring_buffer_attach(struct perf_event *event, |
4498 | struct ring_buffer *rb) | |
4499 | { | |
b69cf536 | 4500 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4501 | unsigned long flags; |
4502 | ||
b69cf536 PZ |
4503 | if (event->rb) { |
4504 | /* | |
4505 | * Should be impossible, we set this when removing | |
4506 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4507 | */ | |
4508 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4509 | |
b69cf536 | 4510 | old_rb = event->rb; |
b69cf536 PZ |
4511 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4512 | list_del_rcu(&event->rb_entry); | |
4513 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4514 | |
2f993cf0 ON |
4515 | event->rcu_batches = get_state_synchronize_rcu(); |
4516 | event->rcu_pending = 1; | |
b69cf536 | 4517 | } |
10c6db11 | 4518 | |
b69cf536 | 4519 | if (rb) { |
2f993cf0 ON |
4520 | if (event->rcu_pending) { |
4521 | cond_synchronize_rcu(event->rcu_batches); | |
4522 | event->rcu_pending = 0; | |
4523 | } | |
4524 | ||
b69cf536 PZ |
4525 | spin_lock_irqsave(&rb->event_lock, flags); |
4526 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4527 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4528 | } | |
4529 | ||
4530 | rcu_assign_pointer(event->rb, rb); | |
4531 | ||
4532 | if (old_rb) { | |
4533 | ring_buffer_put(old_rb); | |
4534 | /* | |
4535 | * Since we detached before setting the new rb, so that we | |
4536 | * could attach the new rb, we could have missed a wakeup. | |
4537 | * Provide it now. | |
4538 | */ | |
4539 | wake_up_all(&event->waitq); | |
4540 | } | |
10c6db11 PZ |
4541 | } |
4542 | ||
4543 | static void ring_buffer_wakeup(struct perf_event *event) | |
4544 | { | |
4545 | struct ring_buffer *rb; | |
4546 | ||
4547 | rcu_read_lock(); | |
4548 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4549 | if (rb) { |
4550 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4551 | wake_up_all(&event->waitq); | |
4552 | } | |
10c6db11 PZ |
4553 | rcu_read_unlock(); |
4554 | } | |
4555 | ||
fdc26706 | 4556 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4557 | { |
76369139 | 4558 | struct ring_buffer *rb; |
7b732a75 | 4559 | |
ac9721f3 | 4560 | rcu_read_lock(); |
76369139 FW |
4561 | rb = rcu_dereference(event->rb); |
4562 | if (rb) { | |
4563 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4564 | rb = NULL; | |
ac9721f3 PZ |
4565 | } |
4566 | rcu_read_unlock(); | |
4567 | ||
76369139 | 4568 | return rb; |
ac9721f3 PZ |
4569 | } |
4570 | ||
fdc26706 | 4571 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4572 | { |
76369139 | 4573 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4574 | return; |
7b732a75 | 4575 | |
9bb5d40c | 4576 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4577 | |
76369139 | 4578 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4579 | } |
4580 | ||
4581 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4582 | { | |
cdd6c482 | 4583 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4584 | |
cdd6c482 | 4585 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4586 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4587 | |
45bfb2e5 PZ |
4588 | if (vma->vm_pgoff) |
4589 | atomic_inc(&event->rb->aux_mmap_count); | |
4590 | ||
1e0fb9ec AL |
4591 | if (event->pmu->event_mapped) |
4592 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4593 | } |
4594 | ||
9bb5d40c PZ |
4595 | /* |
4596 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4597 | * event, or through other events by use of perf_event_set_output(). | |
4598 | * | |
4599 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4600 | * the buffer here, where we still have a VM context. This means we need | |
4601 | * to detach all events redirecting to us. | |
4602 | */ | |
7b732a75 PZ |
4603 | static void perf_mmap_close(struct vm_area_struct *vma) |
4604 | { | |
cdd6c482 | 4605 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4606 | |
b69cf536 | 4607 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4608 | struct user_struct *mmap_user = rb->mmap_user; |
4609 | int mmap_locked = rb->mmap_locked; | |
4610 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4611 | |
1e0fb9ec AL |
4612 | if (event->pmu->event_unmapped) |
4613 | event->pmu->event_unmapped(event); | |
4614 | ||
45bfb2e5 PZ |
4615 | /* |
4616 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4617 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4618 | * serialize with perf_mmap here. | |
4619 | */ | |
4620 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4621 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4622 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4623 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4624 | ||
4625 | rb_free_aux(rb); | |
4626 | mutex_unlock(&event->mmap_mutex); | |
4627 | } | |
4628 | ||
9bb5d40c PZ |
4629 | atomic_dec(&rb->mmap_count); |
4630 | ||
4631 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4632 | goto out_put; |
9bb5d40c | 4633 | |
b69cf536 | 4634 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4635 | mutex_unlock(&event->mmap_mutex); |
4636 | ||
4637 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4638 | if (atomic_read(&rb->mmap_count)) |
4639 | goto out_put; | |
ac9721f3 | 4640 | |
9bb5d40c PZ |
4641 | /* |
4642 | * No other mmap()s, detach from all other events that might redirect | |
4643 | * into the now unreachable buffer. Somewhat complicated by the | |
4644 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4645 | */ | |
4646 | again: | |
4647 | rcu_read_lock(); | |
4648 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4649 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4650 | /* | |
4651 | * This event is en-route to free_event() which will | |
4652 | * detach it and remove it from the list. | |
4653 | */ | |
4654 | continue; | |
4655 | } | |
4656 | rcu_read_unlock(); | |
789f90fc | 4657 | |
9bb5d40c PZ |
4658 | mutex_lock(&event->mmap_mutex); |
4659 | /* | |
4660 | * Check we didn't race with perf_event_set_output() which can | |
4661 | * swizzle the rb from under us while we were waiting to | |
4662 | * acquire mmap_mutex. | |
4663 | * | |
4664 | * If we find a different rb; ignore this event, a next | |
4665 | * iteration will no longer find it on the list. We have to | |
4666 | * still restart the iteration to make sure we're not now | |
4667 | * iterating the wrong list. | |
4668 | */ | |
b69cf536 PZ |
4669 | if (event->rb == rb) |
4670 | ring_buffer_attach(event, NULL); | |
4671 | ||
cdd6c482 | 4672 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4673 | put_event(event); |
ac9721f3 | 4674 | |
9bb5d40c PZ |
4675 | /* |
4676 | * Restart the iteration; either we're on the wrong list or | |
4677 | * destroyed its integrity by doing a deletion. | |
4678 | */ | |
4679 | goto again; | |
7b732a75 | 4680 | } |
9bb5d40c PZ |
4681 | rcu_read_unlock(); |
4682 | ||
4683 | /* | |
4684 | * It could be there's still a few 0-ref events on the list; they'll | |
4685 | * get cleaned up by free_event() -- they'll also still have their | |
4686 | * ref on the rb and will free it whenever they are done with it. | |
4687 | * | |
4688 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4689 | * undo the VM accounting. | |
4690 | */ | |
4691 | ||
4692 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4693 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4694 | free_uid(mmap_user); | |
4695 | ||
b69cf536 | 4696 | out_put: |
9bb5d40c | 4697 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4698 | } |
4699 | ||
f0f37e2f | 4700 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4701 | .open = perf_mmap_open, |
45bfb2e5 | 4702 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4703 | .fault = perf_mmap_fault, |
4704 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4705 | }; |
4706 | ||
4707 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4708 | { | |
cdd6c482 | 4709 | struct perf_event *event = file->private_data; |
22a4f650 | 4710 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4711 | struct user_struct *user = current_user(); |
22a4f650 | 4712 | unsigned long locked, lock_limit; |
45bfb2e5 | 4713 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4714 | unsigned long vma_size; |
4715 | unsigned long nr_pages; | |
45bfb2e5 | 4716 | long user_extra = 0, extra = 0; |
d57e34fd | 4717 | int ret = 0, flags = 0; |
37d81828 | 4718 | |
c7920614 PZ |
4719 | /* |
4720 | * Don't allow mmap() of inherited per-task counters. This would | |
4721 | * create a performance issue due to all children writing to the | |
76369139 | 4722 | * same rb. |
c7920614 PZ |
4723 | */ |
4724 | if (event->cpu == -1 && event->attr.inherit) | |
4725 | return -EINVAL; | |
4726 | ||
43a21ea8 | 4727 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4728 | return -EINVAL; |
7b732a75 PZ |
4729 | |
4730 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4731 | |
4732 | if (vma->vm_pgoff == 0) { | |
4733 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4734 | } else { | |
4735 | /* | |
4736 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4737 | * mapped, all subsequent mappings should have the same size | |
4738 | * and offset. Must be above the normal perf buffer. | |
4739 | */ | |
4740 | u64 aux_offset, aux_size; | |
4741 | ||
4742 | if (!event->rb) | |
4743 | return -EINVAL; | |
4744 | ||
4745 | nr_pages = vma_size / PAGE_SIZE; | |
4746 | ||
4747 | mutex_lock(&event->mmap_mutex); | |
4748 | ret = -EINVAL; | |
4749 | ||
4750 | rb = event->rb; | |
4751 | if (!rb) | |
4752 | goto aux_unlock; | |
4753 | ||
4754 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4755 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4756 | ||
4757 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4758 | goto aux_unlock; | |
4759 | ||
4760 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4761 | goto aux_unlock; | |
4762 | ||
4763 | /* already mapped with a different offset */ | |
4764 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4765 | goto aux_unlock; | |
4766 | ||
4767 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4768 | goto aux_unlock; | |
4769 | ||
4770 | /* already mapped with a different size */ | |
4771 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4772 | goto aux_unlock; | |
4773 | ||
4774 | if (!is_power_of_2(nr_pages)) | |
4775 | goto aux_unlock; | |
4776 | ||
4777 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4778 | goto aux_unlock; | |
4779 | ||
4780 | if (rb_has_aux(rb)) { | |
4781 | atomic_inc(&rb->aux_mmap_count); | |
4782 | ret = 0; | |
4783 | goto unlock; | |
4784 | } | |
4785 | ||
4786 | atomic_set(&rb->aux_mmap_count, 1); | |
4787 | user_extra = nr_pages; | |
4788 | ||
4789 | goto accounting; | |
4790 | } | |
7b732a75 | 4791 | |
7730d865 | 4792 | /* |
76369139 | 4793 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4794 | * can do bitmasks instead of modulo. |
4795 | */ | |
2ed11312 | 4796 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4797 | return -EINVAL; |
4798 | ||
7b732a75 | 4799 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4800 | return -EINVAL; |
4801 | ||
cdd6c482 | 4802 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4803 | again: |
cdd6c482 | 4804 | mutex_lock(&event->mmap_mutex); |
76369139 | 4805 | if (event->rb) { |
9bb5d40c | 4806 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4807 | ret = -EINVAL; |
9bb5d40c PZ |
4808 | goto unlock; |
4809 | } | |
4810 | ||
4811 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4812 | /* | |
4813 | * Raced against perf_mmap_close() through | |
4814 | * perf_event_set_output(). Try again, hope for better | |
4815 | * luck. | |
4816 | */ | |
4817 | mutex_unlock(&event->mmap_mutex); | |
4818 | goto again; | |
4819 | } | |
4820 | ||
ebb3c4c4 PZ |
4821 | goto unlock; |
4822 | } | |
4823 | ||
789f90fc | 4824 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4825 | |
4826 | accounting: | |
cdd6c482 | 4827 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4828 | |
4829 | /* | |
4830 | * Increase the limit linearly with more CPUs: | |
4831 | */ | |
4832 | user_lock_limit *= num_online_cpus(); | |
4833 | ||
789f90fc | 4834 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4835 | |
789f90fc PZ |
4836 | if (user_locked > user_lock_limit) |
4837 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4838 | |
78d7d407 | 4839 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4840 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4841 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4842 | |
459ec28a IM |
4843 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4844 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4845 | ret = -EPERM; |
4846 | goto unlock; | |
4847 | } | |
7b732a75 | 4848 | |
45bfb2e5 | 4849 | WARN_ON(!rb && event->rb); |
906010b2 | 4850 | |
d57e34fd | 4851 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4852 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4853 | |
76369139 | 4854 | if (!rb) { |
45bfb2e5 PZ |
4855 | rb = rb_alloc(nr_pages, |
4856 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4857 | event->cpu, flags); | |
26cb63ad | 4858 | |
45bfb2e5 PZ |
4859 | if (!rb) { |
4860 | ret = -ENOMEM; | |
4861 | goto unlock; | |
4862 | } | |
43a21ea8 | 4863 | |
45bfb2e5 PZ |
4864 | atomic_set(&rb->mmap_count, 1); |
4865 | rb->mmap_user = get_current_user(); | |
4866 | rb->mmap_locked = extra; | |
26cb63ad | 4867 | |
45bfb2e5 | 4868 | ring_buffer_attach(event, rb); |
ac9721f3 | 4869 | |
45bfb2e5 PZ |
4870 | perf_event_init_userpage(event); |
4871 | perf_event_update_userpage(event); | |
4872 | } else { | |
1a594131 AS |
4873 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4874 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4875 | if (!ret) |
4876 | rb->aux_mmap_locked = extra; | |
4877 | } | |
9a0f05cb | 4878 | |
ebb3c4c4 | 4879 | unlock: |
45bfb2e5 PZ |
4880 | if (!ret) { |
4881 | atomic_long_add(user_extra, &user->locked_vm); | |
4882 | vma->vm_mm->pinned_vm += extra; | |
4883 | ||
ac9721f3 | 4884 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4885 | } else if (rb) { |
4886 | atomic_dec(&rb->mmap_count); | |
4887 | } | |
4888 | aux_unlock: | |
cdd6c482 | 4889 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4890 | |
9bb5d40c PZ |
4891 | /* |
4892 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4893 | * vma. | |
4894 | */ | |
26cb63ad | 4895 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4896 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4897 | |
1e0fb9ec AL |
4898 | if (event->pmu->event_mapped) |
4899 | event->pmu->event_mapped(event); | |
4900 | ||
7b732a75 | 4901 | return ret; |
37d81828 PM |
4902 | } |
4903 | ||
3c446b3d PZ |
4904 | static int perf_fasync(int fd, struct file *filp, int on) |
4905 | { | |
496ad9aa | 4906 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4907 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4908 | int retval; |
4909 | ||
5955102c | 4910 | inode_lock(inode); |
cdd6c482 | 4911 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 4912 | inode_unlock(inode); |
3c446b3d PZ |
4913 | |
4914 | if (retval < 0) | |
4915 | return retval; | |
4916 | ||
4917 | return 0; | |
4918 | } | |
4919 | ||
0793a61d | 4920 | static const struct file_operations perf_fops = { |
3326c1ce | 4921 | .llseek = no_llseek, |
0793a61d TG |
4922 | .release = perf_release, |
4923 | .read = perf_read, | |
4924 | .poll = perf_poll, | |
d859e29f | 4925 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4926 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4927 | .mmap = perf_mmap, |
3c446b3d | 4928 | .fasync = perf_fasync, |
0793a61d TG |
4929 | }; |
4930 | ||
925d519a | 4931 | /* |
cdd6c482 | 4932 | * Perf event wakeup |
925d519a PZ |
4933 | * |
4934 | * If there's data, ensure we set the poll() state and publish everything | |
4935 | * to user-space before waking everybody up. | |
4936 | */ | |
4937 | ||
fed66e2c PZ |
4938 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4939 | { | |
4940 | /* only the parent has fasync state */ | |
4941 | if (event->parent) | |
4942 | event = event->parent; | |
4943 | return &event->fasync; | |
4944 | } | |
4945 | ||
cdd6c482 | 4946 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4947 | { |
10c6db11 | 4948 | ring_buffer_wakeup(event); |
4c9e2542 | 4949 | |
cdd6c482 | 4950 | if (event->pending_kill) { |
fed66e2c | 4951 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4952 | event->pending_kill = 0; |
4c9e2542 | 4953 | } |
925d519a PZ |
4954 | } |
4955 | ||
e360adbe | 4956 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4957 | { |
cdd6c482 IM |
4958 | struct perf_event *event = container_of(entry, |
4959 | struct perf_event, pending); | |
d525211f PZ |
4960 | int rctx; |
4961 | ||
4962 | rctx = perf_swevent_get_recursion_context(); | |
4963 | /* | |
4964 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4965 | * and we won't recurse 'further'. | |
4966 | */ | |
79f14641 | 4967 | |
cdd6c482 IM |
4968 | if (event->pending_disable) { |
4969 | event->pending_disable = 0; | |
fae3fde6 | 4970 | perf_event_disable_local(event); |
79f14641 PZ |
4971 | } |
4972 | ||
cdd6c482 IM |
4973 | if (event->pending_wakeup) { |
4974 | event->pending_wakeup = 0; | |
4975 | perf_event_wakeup(event); | |
79f14641 | 4976 | } |
d525211f PZ |
4977 | |
4978 | if (rctx >= 0) | |
4979 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4980 | } |
4981 | ||
39447b38 ZY |
4982 | /* |
4983 | * We assume there is only KVM supporting the callbacks. | |
4984 | * Later on, we might change it to a list if there is | |
4985 | * another virtualization implementation supporting the callbacks. | |
4986 | */ | |
4987 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4988 | ||
4989 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4990 | { | |
4991 | perf_guest_cbs = cbs; | |
4992 | return 0; | |
4993 | } | |
4994 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4995 | ||
4996 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4997 | { | |
4998 | perf_guest_cbs = NULL; | |
4999 | return 0; | |
5000 | } | |
5001 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5002 | ||
4018994f JO |
5003 | static void |
5004 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5005 | struct pt_regs *regs, u64 mask) | |
5006 | { | |
5007 | int bit; | |
5008 | ||
5009 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
5010 | sizeof(mask) * BITS_PER_BYTE) { | |
5011 | u64 val; | |
5012 | ||
5013 | val = perf_reg_value(regs, bit); | |
5014 | perf_output_put(handle, val); | |
5015 | } | |
5016 | } | |
5017 | ||
60e2364e | 5018 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5019 | struct pt_regs *regs, |
5020 | struct pt_regs *regs_user_copy) | |
4018994f | 5021 | { |
88a7c26a AL |
5022 | if (user_mode(regs)) { |
5023 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5024 | regs_user->regs = regs; |
88a7c26a AL |
5025 | } else if (current->mm) { |
5026 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5027 | } else { |
5028 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5029 | regs_user->regs = NULL; | |
4018994f JO |
5030 | } |
5031 | } | |
5032 | ||
60e2364e SE |
5033 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5034 | struct pt_regs *regs) | |
5035 | { | |
5036 | regs_intr->regs = regs; | |
5037 | regs_intr->abi = perf_reg_abi(current); | |
5038 | } | |
5039 | ||
5040 | ||
c5ebcedb JO |
5041 | /* |
5042 | * Get remaining task size from user stack pointer. | |
5043 | * | |
5044 | * It'd be better to take stack vma map and limit this more | |
5045 | * precisly, but there's no way to get it safely under interrupt, | |
5046 | * so using TASK_SIZE as limit. | |
5047 | */ | |
5048 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5049 | { | |
5050 | unsigned long addr = perf_user_stack_pointer(regs); | |
5051 | ||
5052 | if (!addr || addr >= TASK_SIZE) | |
5053 | return 0; | |
5054 | ||
5055 | return TASK_SIZE - addr; | |
5056 | } | |
5057 | ||
5058 | static u16 | |
5059 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5060 | struct pt_regs *regs) | |
5061 | { | |
5062 | u64 task_size; | |
5063 | ||
5064 | /* No regs, no stack pointer, no dump. */ | |
5065 | if (!regs) | |
5066 | return 0; | |
5067 | ||
5068 | /* | |
5069 | * Check if we fit in with the requested stack size into the: | |
5070 | * - TASK_SIZE | |
5071 | * If we don't, we limit the size to the TASK_SIZE. | |
5072 | * | |
5073 | * - remaining sample size | |
5074 | * If we don't, we customize the stack size to | |
5075 | * fit in to the remaining sample size. | |
5076 | */ | |
5077 | ||
5078 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5079 | stack_size = min(stack_size, (u16) task_size); | |
5080 | ||
5081 | /* Current header size plus static size and dynamic size. */ | |
5082 | header_size += 2 * sizeof(u64); | |
5083 | ||
5084 | /* Do we fit in with the current stack dump size? */ | |
5085 | if ((u16) (header_size + stack_size) < header_size) { | |
5086 | /* | |
5087 | * If we overflow the maximum size for the sample, | |
5088 | * we customize the stack dump size to fit in. | |
5089 | */ | |
5090 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5091 | stack_size = round_up(stack_size, sizeof(u64)); | |
5092 | } | |
5093 | ||
5094 | return stack_size; | |
5095 | } | |
5096 | ||
5097 | static void | |
5098 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5099 | struct pt_regs *regs) | |
5100 | { | |
5101 | /* Case of a kernel thread, nothing to dump */ | |
5102 | if (!regs) { | |
5103 | u64 size = 0; | |
5104 | perf_output_put(handle, size); | |
5105 | } else { | |
5106 | unsigned long sp; | |
5107 | unsigned int rem; | |
5108 | u64 dyn_size; | |
5109 | ||
5110 | /* | |
5111 | * We dump: | |
5112 | * static size | |
5113 | * - the size requested by user or the best one we can fit | |
5114 | * in to the sample max size | |
5115 | * data | |
5116 | * - user stack dump data | |
5117 | * dynamic size | |
5118 | * - the actual dumped size | |
5119 | */ | |
5120 | ||
5121 | /* Static size. */ | |
5122 | perf_output_put(handle, dump_size); | |
5123 | ||
5124 | /* Data. */ | |
5125 | sp = perf_user_stack_pointer(regs); | |
5126 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5127 | dyn_size = dump_size - rem; | |
5128 | ||
5129 | perf_output_skip(handle, rem); | |
5130 | ||
5131 | /* Dynamic size. */ | |
5132 | perf_output_put(handle, dyn_size); | |
5133 | } | |
5134 | } | |
5135 | ||
c980d109 ACM |
5136 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5137 | struct perf_sample_data *data, | |
5138 | struct perf_event *event) | |
6844c09d ACM |
5139 | { |
5140 | u64 sample_type = event->attr.sample_type; | |
5141 | ||
5142 | data->type = sample_type; | |
5143 | header->size += event->id_header_size; | |
5144 | ||
5145 | if (sample_type & PERF_SAMPLE_TID) { | |
5146 | /* namespace issues */ | |
5147 | data->tid_entry.pid = perf_event_pid(event, current); | |
5148 | data->tid_entry.tid = perf_event_tid(event, current); | |
5149 | } | |
5150 | ||
5151 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5152 | data->time = perf_event_clock(event); |
6844c09d | 5153 | |
ff3d527c | 5154 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5155 | data->id = primary_event_id(event); |
5156 | ||
5157 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5158 | data->stream_id = event->id; | |
5159 | ||
5160 | if (sample_type & PERF_SAMPLE_CPU) { | |
5161 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5162 | data->cpu_entry.reserved = 0; | |
5163 | } | |
5164 | } | |
5165 | ||
76369139 FW |
5166 | void perf_event_header__init_id(struct perf_event_header *header, |
5167 | struct perf_sample_data *data, | |
5168 | struct perf_event *event) | |
c980d109 ACM |
5169 | { |
5170 | if (event->attr.sample_id_all) | |
5171 | __perf_event_header__init_id(header, data, event); | |
5172 | } | |
5173 | ||
5174 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5175 | struct perf_sample_data *data) | |
5176 | { | |
5177 | u64 sample_type = data->type; | |
5178 | ||
5179 | if (sample_type & PERF_SAMPLE_TID) | |
5180 | perf_output_put(handle, data->tid_entry); | |
5181 | ||
5182 | if (sample_type & PERF_SAMPLE_TIME) | |
5183 | perf_output_put(handle, data->time); | |
5184 | ||
5185 | if (sample_type & PERF_SAMPLE_ID) | |
5186 | perf_output_put(handle, data->id); | |
5187 | ||
5188 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5189 | perf_output_put(handle, data->stream_id); | |
5190 | ||
5191 | if (sample_type & PERF_SAMPLE_CPU) | |
5192 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5193 | |
5194 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5195 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5196 | } |
5197 | ||
76369139 FW |
5198 | void perf_event__output_id_sample(struct perf_event *event, |
5199 | struct perf_output_handle *handle, | |
5200 | struct perf_sample_data *sample) | |
c980d109 ACM |
5201 | { |
5202 | if (event->attr.sample_id_all) | |
5203 | __perf_event__output_id_sample(handle, sample); | |
5204 | } | |
5205 | ||
3dab77fb | 5206 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5207 | struct perf_event *event, |
5208 | u64 enabled, u64 running) | |
3dab77fb | 5209 | { |
cdd6c482 | 5210 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5211 | u64 values[4]; |
5212 | int n = 0; | |
5213 | ||
b5e58793 | 5214 | values[n++] = perf_event_count(event); |
3dab77fb | 5215 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5216 | values[n++] = enabled + |
cdd6c482 | 5217 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5218 | } |
5219 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5220 | values[n++] = running + |
cdd6c482 | 5221 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5222 | } |
5223 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5224 | values[n++] = primary_event_id(event); |
3dab77fb | 5225 | |
76369139 | 5226 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5227 | } |
5228 | ||
5229 | /* | |
cdd6c482 | 5230 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5231 | */ |
5232 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5233 | struct perf_event *event, |
5234 | u64 enabled, u64 running) | |
3dab77fb | 5235 | { |
cdd6c482 IM |
5236 | struct perf_event *leader = event->group_leader, *sub; |
5237 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5238 | u64 values[5]; |
5239 | int n = 0; | |
5240 | ||
5241 | values[n++] = 1 + leader->nr_siblings; | |
5242 | ||
5243 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5244 | values[n++] = enabled; |
3dab77fb PZ |
5245 | |
5246 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5247 | values[n++] = running; |
3dab77fb | 5248 | |
cdd6c482 | 5249 | if (leader != event) |
3dab77fb PZ |
5250 | leader->pmu->read(leader); |
5251 | ||
b5e58793 | 5252 | values[n++] = perf_event_count(leader); |
3dab77fb | 5253 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5254 | values[n++] = primary_event_id(leader); |
3dab77fb | 5255 | |
76369139 | 5256 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5257 | |
65abc865 | 5258 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5259 | n = 0; |
5260 | ||
6f5ab001 JO |
5261 | if ((sub != event) && |
5262 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5263 | sub->pmu->read(sub); |
5264 | ||
b5e58793 | 5265 | values[n++] = perf_event_count(sub); |
3dab77fb | 5266 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5267 | values[n++] = primary_event_id(sub); |
3dab77fb | 5268 | |
76369139 | 5269 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5270 | } |
5271 | } | |
5272 | ||
eed01528 SE |
5273 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5274 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5275 | ||
3dab77fb | 5276 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5277 | struct perf_event *event) |
3dab77fb | 5278 | { |
e3f3541c | 5279 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5280 | u64 read_format = event->attr.read_format; |
5281 | ||
5282 | /* | |
5283 | * compute total_time_enabled, total_time_running | |
5284 | * based on snapshot values taken when the event | |
5285 | * was last scheduled in. | |
5286 | * | |
5287 | * we cannot simply called update_context_time() | |
5288 | * because of locking issue as we are called in | |
5289 | * NMI context | |
5290 | */ | |
c4794295 | 5291 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5292 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5293 | |
cdd6c482 | 5294 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5295 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5296 | else |
eed01528 | 5297 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5298 | } |
5299 | ||
5622f295 MM |
5300 | void perf_output_sample(struct perf_output_handle *handle, |
5301 | struct perf_event_header *header, | |
5302 | struct perf_sample_data *data, | |
cdd6c482 | 5303 | struct perf_event *event) |
5622f295 MM |
5304 | { |
5305 | u64 sample_type = data->type; | |
5306 | ||
5307 | perf_output_put(handle, *header); | |
5308 | ||
ff3d527c AH |
5309 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5310 | perf_output_put(handle, data->id); | |
5311 | ||
5622f295 MM |
5312 | if (sample_type & PERF_SAMPLE_IP) |
5313 | perf_output_put(handle, data->ip); | |
5314 | ||
5315 | if (sample_type & PERF_SAMPLE_TID) | |
5316 | perf_output_put(handle, data->tid_entry); | |
5317 | ||
5318 | if (sample_type & PERF_SAMPLE_TIME) | |
5319 | perf_output_put(handle, data->time); | |
5320 | ||
5321 | if (sample_type & PERF_SAMPLE_ADDR) | |
5322 | perf_output_put(handle, data->addr); | |
5323 | ||
5324 | if (sample_type & PERF_SAMPLE_ID) | |
5325 | perf_output_put(handle, data->id); | |
5326 | ||
5327 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5328 | perf_output_put(handle, data->stream_id); | |
5329 | ||
5330 | if (sample_type & PERF_SAMPLE_CPU) | |
5331 | perf_output_put(handle, data->cpu_entry); | |
5332 | ||
5333 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5334 | perf_output_put(handle, data->period); | |
5335 | ||
5336 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5337 | perf_output_read(handle, event); |
5622f295 MM |
5338 | |
5339 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5340 | if (data->callchain) { | |
5341 | int size = 1; | |
5342 | ||
5343 | if (data->callchain) | |
5344 | size += data->callchain->nr; | |
5345 | ||
5346 | size *= sizeof(u64); | |
5347 | ||
76369139 | 5348 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5349 | } else { |
5350 | u64 nr = 0; | |
5351 | perf_output_put(handle, nr); | |
5352 | } | |
5353 | } | |
5354 | ||
5355 | if (sample_type & PERF_SAMPLE_RAW) { | |
5356 | if (data->raw) { | |
fa128e6a AS |
5357 | u32 raw_size = data->raw->size; |
5358 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5359 | sizeof(u64)) - sizeof(u32); | |
5360 | u64 zero = 0; | |
5361 | ||
5362 | perf_output_put(handle, real_size); | |
5363 | __output_copy(handle, data->raw->data, raw_size); | |
5364 | if (real_size - raw_size) | |
5365 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5366 | } else { |
5367 | struct { | |
5368 | u32 size; | |
5369 | u32 data; | |
5370 | } raw = { | |
5371 | .size = sizeof(u32), | |
5372 | .data = 0, | |
5373 | }; | |
5374 | perf_output_put(handle, raw); | |
5375 | } | |
5376 | } | |
a7ac67ea | 5377 | |
bce38cd5 SE |
5378 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5379 | if (data->br_stack) { | |
5380 | size_t size; | |
5381 | ||
5382 | size = data->br_stack->nr | |
5383 | * sizeof(struct perf_branch_entry); | |
5384 | ||
5385 | perf_output_put(handle, data->br_stack->nr); | |
5386 | perf_output_copy(handle, data->br_stack->entries, size); | |
5387 | } else { | |
5388 | /* | |
5389 | * we always store at least the value of nr | |
5390 | */ | |
5391 | u64 nr = 0; | |
5392 | perf_output_put(handle, nr); | |
5393 | } | |
5394 | } | |
4018994f JO |
5395 | |
5396 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5397 | u64 abi = data->regs_user.abi; | |
5398 | ||
5399 | /* | |
5400 | * If there are no regs to dump, notice it through | |
5401 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5402 | */ | |
5403 | perf_output_put(handle, abi); | |
5404 | ||
5405 | if (abi) { | |
5406 | u64 mask = event->attr.sample_regs_user; | |
5407 | perf_output_sample_regs(handle, | |
5408 | data->regs_user.regs, | |
5409 | mask); | |
5410 | } | |
5411 | } | |
c5ebcedb | 5412 | |
a5cdd40c | 5413 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5414 | perf_output_sample_ustack(handle, |
5415 | data->stack_user_size, | |
5416 | data->regs_user.regs); | |
a5cdd40c | 5417 | } |
c3feedf2 AK |
5418 | |
5419 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5420 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5421 | |
5422 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5423 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5424 | |
fdfbbd07 AK |
5425 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5426 | perf_output_put(handle, data->txn); | |
5427 | ||
60e2364e SE |
5428 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5429 | u64 abi = data->regs_intr.abi; | |
5430 | /* | |
5431 | * If there are no regs to dump, notice it through | |
5432 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5433 | */ | |
5434 | perf_output_put(handle, abi); | |
5435 | ||
5436 | if (abi) { | |
5437 | u64 mask = event->attr.sample_regs_intr; | |
5438 | ||
5439 | perf_output_sample_regs(handle, | |
5440 | data->regs_intr.regs, | |
5441 | mask); | |
5442 | } | |
5443 | } | |
5444 | ||
a5cdd40c PZ |
5445 | if (!event->attr.watermark) { |
5446 | int wakeup_events = event->attr.wakeup_events; | |
5447 | ||
5448 | if (wakeup_events) { | |
5449 | struct ring_buffer *rb = handle->rb; | |
5450 | int events = local_inc_return(&rb->events); | |
5451 | ||
5452 | if (events >= wakeup_events) { | |
5453 | local_sub(wakeup_events, &rb->events); | |
5454 | local_inc(&rb->wakeup); | |
5455 | } | |
5456 | } | |
5457 | } | |
5622f295 MM |
5458 | } |
5459 | ||
5460 | void perf_prepare_sample(struct perf_event_header *header, | |
5461 | struct perf_sample_data *data, | |
cdd6c482 | 5462 | struct perf_event *event, |
5622f295 | 5463 | struct pt_regs *regs) |
7b732a75 | 5464 | { |
cdd6c482 | 5465 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5466 | |
cdd6c482 | 5467 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5468 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5469 | |
5470 | header->misc = 0; | |
5471 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5472 | |
c980d109 | 5473 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5474 | |
c320c7b7 | 5475 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5476 | data->ip = perf_instruction_pointer(regs); |
5477 | ||
b23f3325 | 5478 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5479 | int size = 1; |
394ee076 | 5480 | |
e6dab5ff | 5481 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5482 | |
5483 | if (data->callchain) | |
5484 | size += data->callchain->nr; | |
5485 | ||
5486 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5487 | } |
5488 | ||
3a43ce68 | 5489 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5490 | int size = sizeof(u32); |
5491 | ||
5492 | if (data->raw) | |
5493 | size += data->raw->size; | |
5494 | else | |
5495 | size += sizeof(u32); | |
5496 | ||
fa128e6a | 5497 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5498 | } |
bce38cd5 SE |
5499 | |
5500 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5501 | int size = sizeof(u64); /* nr */ | |
5502 | if (data->br_stack) { | |
5503 | size += data->br_stack->nr | |
5504 | * sizeof(struct perf_branch_entry); | |
5505 | } | |
5506 | header->size += size; | |
5507 | } | |
4018994f | 5508 | |
2565711f | 5509 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5510 | perf_sample_regs_user(&data->regs_user, regs, |
5511 | &data->regs_user_copy); | |
2565711f | 5512 | |
4018994f JO |
5513 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5514 | /* regs dump ABI info */ | |
5515 | int size = sizeof(u64); | |
5516 | ||
4018994f JO |
5517 | if (data->regs_user.regs) { |
5518 | u64 mask = event->attr.sample_regs_user; | |
5519 | size += hweight64(mask) * sizeof(u64); | |
5520 | } | |
5521 | ||
5522 | header->size += size; | |
5523 | } | |
c5ebcedb JO |
5524 | |
5525 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5526 | /* | |
5527 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5528 | * processed as the last one or have additional check added | |
5529 | * in case new sample type is added, because we could eat | |
5530 | * up the rest of the sample size. | |
5531 | */ | |
c5ebcedb JO |
5532 | u16 stack_size = event->attr.sample_stack_user; |
5533 | u16 size = sizeof(u64); | |
5534 | ||
c5ebcedb | 5535 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5536 | data->regs_user.regs); |
c5ebcedb JO |
5537 | |
5538 | /* | |
5539 | * If there is something to dump, add space for the dump | |
5540 | * itself and for the field that tells the dynamic size, | |
5541 | * which is how many have been actually dumped. | |
5542 | */ | |
5543 | if (stack_size) | |
5544 | size += sizeof(u64) + stack_size; | |
5545 | ||
5546 | data->stack_user_size = stack_size; | |
5547 | header->size += size; | |
5548 | } | |
60e2364e SE |
5549 | |
5550 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5551 | /* regs dump ABI info */ | |
5552 | int size = sizeof(u64); | |
5553 | ||
5554 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5555 | ||
5556 | if (data->regs_intr.regs) { | |
5557 | u64 mask = event->attr.sample_regs_intr; | |
5558 | ||
5559 | size += hweight64(mask) * sizeof(u64); | |
5560 | } | |
5561 | ||
5562 | header->size += size; | |
5563 | } | |
5622f295 | 5564 | } |
7f453c24 | 5565 | |
21509084 YZ |
5566 | void perf_event_output(struct perf_event *event, |
5567 | struct perf_sample_data *data, | |
5568 | struct pt_regs *regs) | |
5622f295 MM |
5569 | { |
5570 | struct perf_output_handle handle; | |
5571 | struct perf_event_header header; | |
689802b2 | 5572 | |
927c7a9e FW |
5573 | /* protect the callchain buffers */ |
5574 | rcu_read_lock(); | |
5575 | ||
cdd6c482 | 5576 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5577 | |
a7ac67ea | 5578 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5579 | goto exit; |
0322cd6e | 5580 | |
cdd6c482 | 5581 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5582 | |
8a057d84 | 5583 | perf_output_end(&handle); |
927c7a9e FW |
5584 | |
5585 | exit: | |
5586 | rcu_read_unlock(); | |
0322cd6e PZ |
5587 | } |
5588 | ||
38b200d6 | 5589 | /* |
cdd6c482 | 5590 | * read event_id |
38b200d6 PZ |
5591 | */ |
5592 | ||
5593 | struct perf_read_event { | |
5594 | struct perf_event_header header; | |
5595 | ||
5596 | u32 pid; | |
5597 | u32 tid; | |
38b200d6 PZ |
5598 | }; |
5599 | ||
5600 | static void | |
cdd6c482 | 5601 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5602 | struct task_struct *task) |
5603 | { | |
5604 | struct perf_output_handle handle; | |
c980d109 | 5605 | struct perf_sample_data sample; |
dfc65094 | 5606 | struct perf_read_event read_event = { |
38b200d6 | 5607 | .header = { |
cdd6c482 | 5608 | .type = PERF_RECORD_READ, |
38b200d6 | 5609 | .misc = 0, |
c320c7b7 | 5610 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5611 | }, |
cdd6c482 IM |
5612 | .pid = perf_event_pid(event, task), |
5613 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5614 | }; |
3dab77fb | 5615 | int ret; |
38b200d6 | 5616 | |
c980d109 | 5617 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5618 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5619 | if (ret) |
5620 | return; | |
5621 | ||
dfc65094 | 5622 | perf_output_put(&handle, read_event); |
cdd6c482 | 5623 | perf_output_read(&handle, event); |
c980d109 | 5624 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5625 | |
38b200d6 PZ |
5626 | perf_output_end(&handle); |
5627 | } | |
5628 | ||
52d857a8 JO |
5629 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5630 | ||
5631 | static void | |
5632 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5633 | perf_event_aux_output_cb output, |
5634 | void *data) | |
5635 | { | |
5636 | struct perf_event *event; | |
5637 | ||
5638 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5639 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5640 | continue; | |
5641 | if (!event_filter_match(event)) | |
5642 | continue; | |
67516844 | 5643 | output(event, data); |
52d857a8 JO |
5644 | } |
5645 | } | |
5646 | ||
4e93ad60 JO |
5647 | static void |
5648 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5649 | struct perf_event_context *task_ctx) | |
5650 | { | |
5651 | rcu_read_lock(); | |
5652 | preempt_disable(); | |
5653 | perf_event_aux_ctx(task_ctx, output, data); | |
5654 | preempt_enable(); | |
5655 | rcu_read_unlock(); | |
5656 | } | |
5657 | ||
52d857a8 | 5658 | static void |
67516844 | 5659 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5660 | struct perf_event_context *task_ctx) |
5661 | { | |
5662 | struct perf_cpu_context *cpuctx; | |
5663 | struct perf_event_context *ctx; | |
5664 | struct pmu *pmu; | |
5665 | int ctxn; | |
5666 | ||
4e93ad60 JO |
5667 | /* |
5668 | * If we have task_ctx != NULL we only notify | |
5669 | * the task context itself. The task_ctx is set | |
5670 | * only for EXIT events before releasing task | |
5671 | * context. | |
5672 | */ | |
5673 | if (task_ctx) { | |
5674 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5675 | return; | |
5676 | } | |
5677 | ||
52d857a8 JO |
5678 | rcu_read_lock(); |
5679 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5680 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5681 | if (cpuctx->unique_pmu != pmu) | |
5682 | goto next; | |
67516844 | 5683 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5684 | ctxn = pmu->task_ctx_nr; |
5685 | if (ctxn < 0) | |
5686 | goto next; | |
5687 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5688 | if (ctx) | |
67516844 | 5689 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5690 | next: |
5691 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5692 | } | |
52d857a8 JO |
5693 | rcu_read_unlock(); |
5694 | } | |
5695 | ||
60313ebe | 5696 | /* |
9f498cc5 PZ |
5697 | * task tracking -- fork/exit |
5698 | * | |
13d7a241 | 5699 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5700 | */ |
5701 | ||
9f498cc5 | 5702 | struct perf_task_event { |
3a80b4a3 | 5703 | struct task_struct *task; |
cdd6c482 | 5704 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5705 | |
5706 | struct { | |
5707 | struct perf_event_header header; | |
5708 | ||
5709 | u32 pid; | |
5710 | u32 ppid; | |
9f498cc5 PZ |
5711 | u32 tid; |
5712 | u32 ptid; | |
393b2ad8 | 5713 | u64 time; |
cdd6c482 | 5714 | } event_id; |
60313ebe PZ |
5715 | }; |
5716 | ||
67516844 JO |
5717 | static int perf_event_task_match(struct perf_event *event) |
5718 | { | |
13d7a241 SE |
5719 | return event->attr.comm || event->attr.mmap || |
5720 | event->attr.mmap2 || event->attr.mmap_data || | |
5721 | event->attr.task; | |
67516844 JO |
5722 | } |
5723 | ||
cdd6c482 | 5724 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5725 | void *data) |
60313ebe | 5726 | { |
52d857a8 | 5727 | struct perf_task_event *task_event = data; |
60313ebe | 5728 | struct perf_output_handle handle; |
c980d109 | 5729 | struct perf_sample_data sample; |
9f498cc5 | 5730 | struct task_struct *task = task_event->task; |
c980d109 | 5731 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5732 | |
67516844 JO |
5733 | if (!perf_event_task_match(event)) |
5734 | return; | |
5735 | ||
c980d109 | 5736 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5737 | |
c980d109 | 5738 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5739 | task_event->event_id.header.size); |
ef60777c | 5740 | if (ret) |
c980d109 | 5741 | goto out; |
60313ebe | 5742 | |
cdd6c482 IM |
5743 | task_event->event_id.pid = perf_event_pid(event, task); |
5744 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5745 | |
cdd6c482 IM |
5746 | task_event->event_id.tid = perf_event_tid(event, task); |
5747 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5748 | |
34f43927 PZ |
5749 | task_event->event_id.time = perf_event_clock(event); |
5750 | ||
cdd6c482 | 5751 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5752 | |
c980d109 ACM |
5753 | perf_event__output_id_sample(event, &handle, &sample); |
5754 | ||
60313ebe | 5755 | perf_output_end(&handle); |
c980d109 ACM |
5756 | out: |
5757 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5758 | } |
5759 | ||
cdd6c482 IM |
5760 | static void perf_event_task(struct task_struct *task, |
5761 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5762 | int new) |
60313ebe | 5763 | { |
9f498cc5 | 5764 | struct perf_task_event task_event; |
60313ebe | 5765 | |
cdd6c482 IM |
5766 | if (!atomic_read(&nr_comm_events) && |
5767 | !atomic_read(&nr_mmap_events) && | |
5768 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5769 | return; |
5770 | ||
9f498cc5 | 5771 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5772 | .task = task, |
5773 | .task_ctx = task_ctx, | |
cdd6c482 | 5774 | .event_id = { |
60313ebe | 5775 | .header = { |
cdd6c482 | 5776 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5777 | .misc = 0, |
cdd6c482 | 5778 | .size = sizeof(task_event.event_id), |
60313ebe | 5779 | }, |
573402db PZ |
5780 | /* .pid */ |
5781 | /* .ppid */ | |
9f498cc5 PZ |
5782 | /* .tid */ |
5783 | /* .ptid */ | |
34f43927 | 5784 | /* .time */ |
60313ebe PZ |
5785 | }, |
5786 | }; | |
5787 | ||
67516844 | 5788 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5789 | &task_event, |
5790 | task_ctx); | |
9f498cc5 PZ |
5791 | } |
5792 | ||
cdd6c482 | 5793 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5794 | { |
cdd6c482 | 5795 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5796 | } |
5797 | ||
8d1b2d93 PZ |
5798 | /* |
5799 | * comm tracking | |
5800 | */ | |
5801 | ||
5802 | struct perf_comm_event { | |
22a4f650 IM |
5803 | struct task_struct *task; |
5804 | char *comm; | |
8d1b2d93 PZ |
5805 | int comm_size; |
5806 | ||
5807 | struct { | |
5808 | struct perf_event_header header; | |
5809 | ||
5810 | u32 pid; | |
5811 | u32 tid; | |
cdd6c482 | 5812 | } event_id; |
8d1b2d93 PZ |
5813 | }; |
5814 | ||
67516844 JO |
5815 | static int perf_event_comm_match(struct perf_event *event) |
5816 | { | |
5817 | return event->attr.comm; | |
5818 | } | |
5819 | ||
cdd6c482 | 5820 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5821 | void *data) |
8d1b2d93 | 5822 | { |
52d857a8 | 5823 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5824 | struct perf_output_handle handle; |
c980d109 | 5825 | struct perf_sample_data sample; |
cdd6c482 | 5826 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5827 | int ret; |
5828 | ||
67516844 JO |
5829 | if (!perf_event_comm_match(event)) |
5830 | return; | |
5831 | ||
c980d109 ACM |
5832 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5833 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5834 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5835 | |
5836 | if (ret) | |
c980d109 | 5837 | goto out; |
8d1b2d93 | 5838 | |
cdd6c482 IM |
5839 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5840 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5841 | |
cdd6c482 | 5842 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5843 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5844 | comm_event->comm_size); |
c980d109 ACM |
5845 | |
5846 | perf_event__output_id_sample(event, &handle, &sample); | |
5847 | ||
8d1b2d93 | 5848 | perf_output_end(&handle); |
c980d109 ACM |
5849 | out: |
5850 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5851 | } |
5852 | ||
cdd6c482 | 5853 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5854 | { |
413ee3b4 | 5855 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5856 | unsigned int size; |
8d1b2d93 | 5857 | |
413ee3b4 | 5858 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5859 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5860 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5861 | |
5862 | comm_event->comm = comm; | |
5863 | comm_event->comm_size = size; | |
5864 | ||
cdd6c482 | 5865 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5866 | |
67516844 | 5867 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5868 | comm_event, |
5869 | NULL); | |
8d1b2d93 PZ |
5870 | } |
5871 | ||
82b89778 | 5872 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5873 | { |
9ee318a7 PZ |
5874 | struct perf_comm_event comm_event; |
5875 | ||
cdd6c482 | 5876 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5877 | return; |
a63eaf34 | 5878 | |
9ee318a7 | 5879 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5880 | .task = task, |
573402db PZ |
5881 | /* .comm */ |
5882 | /* .comm_size */ | |
cdd6c482 | 5883 | .event_id = { |
573402db | 5884 | .header = { |
cdd6c482 | 5885 | .type = PERF_RECORD_COMM, |
82b89778 | 5886 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5887 | /* .size */ |
5888 | }, | |
5889 | /* .pid */ | |
5890 | /* .tid */ | |
8d1b2d93 PZ |
5891 | }, |
5892 | }; | |
5893 | ||
cdd6c482 | 5894 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5895 | } |
5896 | ||
0a4a9391 PZ |
5897 | /* |
5898 | * mmap tracking | |
5899 | */ | |
5900 | ||
5901 | struct perf_mmap_event { | |
089dd79d PZ |
5902 | struct vm_area_struct *vma; |
5903 | ||
5904 | const char *file_name; | |
5905 | int file_size; | |
13d7a241 SE |
5906 | int maj, min; |
5907 | u64 ino; | |
5908 | u64 ino_generation; | |
f972eb63 | 5909 | u32 prot, flags; |
0a4a9391 PZ |
5910 | |
5911 | struct { | |
5912 | struct perf_event_header header; | |
5913 | ||
5914 | u32 pid; | |
5915 | u32 tid; | |
5916 | u64 start; | |
5917 | u64 len; | |
5918 | u64 pgoff; | |
cdd6c482 | 5919 | } event_id; |
0a4a9391 PZ |
5920 | }; |
5921 | ||
67516844 JO |
5922 | static int perf_event_mmap_match(struct perf_event *event, |
5923 | void *data) | |
5924 | { | |
5925 | struct perf_mmap_event *mmap_event = data; | |
5926 | struct vm_area_struct *vma = mmap_event->vma; | |
5927 | int executable = vma->vm_flags & VM_EXEC; | |
5928 | ||
5929 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5930 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5931 | } |
5932 | ||
cdd6c482 | 5933 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5934 | void *data) |
0a4a9391 | 5935 | { |
52d857a8 | 5936 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5937 | struct perf_output_handle handle; |
c980d109 | 5938 | struct perf_sample_data sample; |
cdd6c482 | 5939 | int size = mmap_event->event_id.header.size; |
c980d109 | 5940 | int ret; |
0a4a9391 | 5941 | |
67516844 JO |
5942 | if (!perf_event_mmap_match(event, data)) |
5943 | return; | |
5944 | ||
13d7a241 SE |
5945 | if (event->attr.mmap2) { |
5946 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5947 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5948 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5949 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5950 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5951 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5952 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5953 | } |
5954 | ||
c980d109 ACM |
5955 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5956 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5957 | mmap_event->event_id.header.size); |
0a4a9391 | 5958 | if (ret) |
c980d109 | 5959 | goto out; |
0a4a9391 | 5960 | |
cdd6c482 IM |
5961 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5962 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5963 | |
cdd6c482 | 5964 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5965 | |
5966 | if (event->attr.mmap2) { | |
5967 | perf_output_put(&handle, mmap_event->maj); | |
5968 | perf_output_put(&handle, mmap_event->min); | |
5969 | perf_output_put(&handle, mmap_event->ino); | |
5970 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5971 | perf_output_put(&handle, mmap_event->prot); |
5972 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5973 | } |
5974 | ||
76369139 | 5975 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5976 | mmap_event->file_size); |
c980d109 ACM |
5977 | |
5978 | perf_event__output_id_sample(event, &handle, &sample); | |
5979 | ||
78d613eb | 5980 | perf_output_end(&handle); |
c980d109 ACM |
5981 | out: |
5982 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5983 | } |
5984 | ||
cdd6c482 | 5985 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5986 | { |
089dd79d PZ |
5987 | struct vm_area_struct *vma = mmap_event->vma; |
5988 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5989 | int maj = 0, min = 0; |
5990 | u64 ino = 0, gen = 0; | |
f972eb63 | 5991 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5992 | unsigned int size; |
5993 | char tmp[16]; | |
5994 | char *buf = NULL; | |
2c42cfbf | 5995 | char *name; |
413ee3b4 | 5996 | |
0a4a9391 | 5997 | if (file) { |
13d7a241 SE |
5998 | struct inode *inode; |
5999 | dev_t dev; | |
3ea2f2b9 | 6000 | |
2c42cfbf | 6001 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 6002 | if (!buf) { |
c7e548b4 ON |
6003 | name = "//enomem"; |
6004 | goto cpy_name; | |
0a4a9391 | 6005 | } |
413ee3b4 | 6006 | /* |
3ea2f2b9 | 6007 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
6008 | * need to add enough zero bytes after the string to handle |
6009 | * the 64bit alignment we do later. | |
6010 | */ | |
9bf39ab2 | 6011 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 6012 | if (IS_ERR(name)) { |
c7e548b4 ON |
6013 | name = "//toolong"; |
6014 | goto cpy_name; | |
0a4a9391 | 6015 | } |
13d7a241 SE |
6016 | inode = file_inode(vma->vm_file); |
6017 | dev = inode->i_sb->s_dev; | |
6018 | ino = inode->i_ino; | |
6019 | gen = inode->i_generation; | |
6020 | maj = MAJOR(dev); | |
6021 | min = MINOR(dev); | |
f972eb63 PZ |
6022 | |
6023 | if (vma->vm_flags & VM_READ) | |
6024 | prot |= PROT_READ; | |
6025 | if (vma->vm_flags & VM_WRITE) | |
6026 | prot |= PROT_WRITE; | |
6027 | if (vma->vm_flags & VM_EXEC) | |
6028 | prot |= PROT_EXEC; | |
6029 | ||
6030 | if (vma->vm_flags & VM_MAYSHARE) | |
6031 | flags = MAP_SHARED; | |
6032 | else | |
6033 | flags = MAP_PRIVATE; | |
6034 | ||
6035 | if (vma->vm_flags & VM_DENYWRITE) | |
6036 | flags |= MAP_DENYWRITE; | |
6037 | if (vma->vm_flags & VM_MAYEXEC) | |
6038 | flags |= MAP_EXECUTABLE; | |
6039 | if (vma->vm_flags & VM_LOCKED) | |
6040 | flags |= MAP_LOCKED; | |
6041 | if (vma->vm_flags & VM_HUGETLB) | |
6042 | flags |= MAP_HUGETLB; | |
6043 | ||
c7e548b4 | 6044 | goto got_name; |
0a4a9391 | 6045 | } else { |
fbe26abe JO |
6046 | if (vma->vm_ops && vma->vm_ops->name) { |
6047 | name = (char *) vma->vm_ops->name(vma); | |
6048 | if (name) | |
6049 | goto cpy_name; | |
6050 | } | |
6051 | ||
2c42cfbf | 6052 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6053 | if (name) |
6054 | goto cpy_name; | |
089dd79d | 6055 | |
32c5fb7e | 6056 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6057 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6058 | name = "[heap]"; |
6059 | goto cpy_name; | |
32c5fb7e ON |
6060 | } |
6061 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6062 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6063 | name = "[stack]"; |
6064 | goto cpy_name; | |
089dd79d PZ |
6065 | } |
6066 | ||
c7e548b4 ON |
6067 | name = "//anon"; |
6068 | goto cpy_name; | |
0a4a9391 PZ |
6069 | } |
6070 | ||
c7e548b4 ON |
6071 | cpy_name: |
6072 | strlcpy(tmp, name, sizeof(tmp)); | |
6073 | name = tmp; | |
0a4a9391 | 6074 | got_name: |
2c42cfbf PZ |
6075 | /* |
6076 | * Since our buffer works in 8 byte units we need to align our string | |
6077 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6078 | * zero'd out to avoid leaking random bits to userspace. | |
6079 | */ | |
6080 | size = strlen(name)+1; | |
6081 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6082 | name[size++] = '\0'; | |
0a4a9391 PZ |
6083 | |
6084 | mmap_event->file_name = name; | |
6085 | mmap_event->file_size = size; | |
13d7a241 SE |
6086 | mmap_event->maj = maj; |
6087 | mmap_event->min = min; | |
6088 | mmap_event->ino = ino; | |
6089 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6090 | mmap_event->prot = prot; |
6091 | mmap_event->flags = flags; | |
0a4a9391 | 6092 | |
2fe85427 SE |
6093 | if (!(vma->vm_flags & VM_EXEC)) |
6094 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6095 | ||
cdd6c482 | 6096 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6097 | |
67516844 | 6098 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6099 | mmap_event, |
6100 | NULL); | |
665c2142 | 6101 | |
0a4a9391 PZ |
6102 | kfree(buf); |
6103 | } | |
6104 | ||
3af9e859 | 6105 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6106 | { |
9ee318a7 PZ |
6107 | struct perf_mmap_event mmap_event; |
6108 | ||
cdd6c482 | 6109 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6110 | return; |
6111 | ||
6112 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6113 | .vma = vma, |
573402db PZ |
6114 | /* .file_name */ |
6115 | /* .file_size */ | |
cdd6c482 | 6116 | .event_id = { |
573402db | 6117 | .header = { |
cdd6c482 | 6118 | .type = PERF_RECORD_MMAP, |
39447b38 | 6119 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6120 | /* .size */ |
6121 | }, | |
6122 | /* .pid */ | |
6123 | /* .tid */ | |
089dd79d PZ |
6124 | .start = vma->vm_start, |
6125 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6126 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6127 | }, |
13d7a241 SE |
6128 | /* .maj (attr_mmap2 only) */ |
6129 | /* .min (attr_mmap2 only) */ | |
6130 | /* .ino (attr_mmap2 only) */ | |
6131 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6132 | /* .prot (attr_mmap2 only) */ |
6133 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6134 | }; |
6135 | ||
cdd6c482 | 6136 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6137 | } |
6138 | ||
68db7e98 AS |
6139 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6140 | unsigned long size, u64 flags) | |
6141 | { | |
6142 | struct perf_output_handle handle; | |
6143 | struct perf_sample_data sample; | |
6144 | struct perf_aux_event { | |
6145 | struct perf_event_header header; | |
6146 | u64 offset; | |
6147 | u64 size; | |
6148 | u64 flags; | |
6149 | } rec = { | |
6150 | .header = { | |
6151 | .type = PERF_RECORD_AUX, | |
6152 | .misc = 0, | |
6153 | .size = sizeof(rec), | |
6154 | }, | |
6155 | .offset = head, | |
6156 | .size = size, | |
6157 | .flags = flags, | |
6158 | }; | |
6159 | int ret; | |
6160 | ||
6161 | perf_event_header__init_id(&rec.header, &sample, event); | |
6162 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6163 | ||
6164 | if (ret) | |
6165 | return; | |
6166 | ||
6167 | perf_output_put(&handle, rec); | |
6168 | perf_event__output_id_sample(event, &handle, &sample); | |
6169 | ||
6170 | perf_output_end(&handle); | |
6171 | } | |
6172 | ||
f38b0dbb KL |
6173 | /* |
6174 | * Lost/dropped samples logging | |
6175 | */ | |
6176 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6177 | { | |
6178 | struct perf_output_handle handle; | |
6179 | struct perf_sample_data sample; | |
6180 | int ret; | |
6181 | ||
6182 | struct { | |
6183 | struct perf_event_header header; | |
6184 | u64 lost; | |
6185 | } lost_samples_event = { | |
6186 | .header = { | |
6187 | .type = PERF_RECORD_LOST_SAMPLES, | |
6188 | .misc = 0, | |
6189 | .size = sizeof(lost_samples_event), | |
6190 | }, | |
6191 | .lost = lost, | |
6192 | }; | |
6193 | ||
6194 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6195 | ||
6196 | ret = perf_output_begin(&handle, event, | |
6197 | lost_samples_event.header.size); | |
6198 | if (ret) | |
6199 | return; | |
6200 | ||
6201 | perf_output_put(&handle, lost_samples_event); | |
6202 | perf_event__output_id_sample(event, &handle, &sample); | |
6203 | perf_output_end(&handle); | |
6204 | } | |
6205 | ||
45ac1403 AH |
6206 | /* |
6207 | * context_switch tracking | |
6208 | */ | |
6209 | ||
6210 | struct perf_switch_event { | |
6211 | struct task_struct *task; | |
6212 | struct task_struct *next_prev; | |
6213 | ||
6214 | struct { | |
6215 | struct perf_event_header header; | |
6216 | u32 next_prev_pid; | |
6217 | u32 next_prev_tid; | |
6218 | } event_id; | |
6219 | }; | |
6220 | ||
6221 | static int perf_event_switch_match(struct perf_event *event) | |
6222 | { | |
6223 | return event->attr.context_switch; | |
6224 | } | |
6225 | ||
6226 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6227 | { | |
6228 | struct perf_switch_event *se = data; | |
6229 | struct perf_output_handle handle; | |
6230 | struct perf_sample_data sample; | |
6231 | int ret; | |
6232 | ||
6233 | if (!perf_event_switch_match(event)) | |
6234 | return; | |
6235 | ||
6236 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6237 | if (event->ctx->task) { | |
6238 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6239 | se->event_id.header.size = sizeof(se->event_id.header); | |
6240 | } else { | |
6241 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6242 | se->event_id.header.size = sizeof(se->event_id); | |
6243 | se->event_id.next_prev_pid = | |
6244 | perf_event_pid(event, se->next_prev); | |
6245 | se->event_id.next_prev_tid = | |
6246 | perf_event_tid(event, se->next_prev); | |
6247 | } | |
6248 | ||
6249 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6250 | ||
6251 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6252 | if (ret) | |
6253 | return; | |
6254 | ||
6255 | if (event->ctx->task) | |
6256 | perf_output_put(&handle, se->event_id.header); | |
6257 | else | |
6258 | perf_output_put(&handle, se->event_id); | |
6259 | ||
6260 | perf_event__output_id_sample(event, &handle, &sample); | |
6261 | ||
6262 | perf_output_end(&handle); | |
6263 | } | |
6264 | ||
6265 | static void perf_event_switch(struct task_struct *task, | |
6266 | struct task_struct *next_prev, bool sched_in) | |
6267 | { | |
6268 | struct perf_switch_event switch_event; | |
6269 | ||
6270 | /* N.B. caller checks nr_switch_events != 0 */ | |
6271 | ||
6272 | switch_event = (struct perf_switch_event){ | |
6273 | .task = task, | |
6274 | .next_prev = next_prev, | |
6275 | .event_id = { | |
6276 | .header = { | |
6277 | /* .type */ | |
6278 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6279 | /* .size */ | |
6280 | }, | |
6281 | /* .next_prev_pid */ | |
6282 | /* .next_prev_tid */ | |
6283 | }, | |
6284 | }; | |
6285 | ||
6286 | perf_event_aux(perf_event_switch_output, | |
6287 | &switch_event, | |
6288 | NULL); | |
6289 | } | |
6290 | ||
a78ac325 PZ |
6291 | /* |
6292 | * IRQ throttle logging | |
6293 | */ | |
6294 | ||
cdd6c482 | 6295 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6296 | { |
6297 | struct perf_output_handle handle; | |
c980d109 | 6298 | struct perf_sample_data sample; |
a78ac325 PZ |
6299 | int ret; |
6300 | ||
6301 | struct { | |
6302 | struct perf_event_header header; | |
6303 | u64 time; | |
cca3f454 | 6304 | u64 id; |
7f453c24 | 6305 | u64 stream_id; |
a78ac325 PZ |
6306 | } throttle_event = { |
6307 | .header = { | |
cdd6c482 | 6308 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6309 | .misc = 0, |
6310 | .size = sizeof(throttle_event), | |
6311 | }, | |
34f43927 | 6312 | .time = perf_event_clock(event), |
cdd6c482 IM |
6313 | .id = primary_event_id(event), |
6314 | .stream_id = event->id, | |
a78ac325 PZ |
6315 | }; |
6316 | ||
966ee4d6 | 6317 | if (enable) |
cdd6c482 | 6318 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6319 | |
c980d109 ACM |
6320 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6321 | ||
6322 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6323 | throttle_event.header.size); |
a78ac325 PZ |
6324 | if (ret) |
6325 | return; | |
6326 | ||
6327 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6328 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6329 | perf_output_end(&handle); |
6330 | } | |
6331 | ||
ec0d7729 AS |
6332 | static void perf_log_itrace_start(struct perf_event *event) |
6333 | { | |
6334 | struct perf_output_handle handle; | |
6335 | struct perf_sample_data sample; | |
6336 | struct perf_aux_event { | |
6337 | struct perf_event_header header; | |
6338 | u32 pid; | |
6339 | u32 tid; | |
6340 | } rec; | |
6341 | int ret; | |
6342 | ||
6343 | if (event->parent) | |
6344 | event = event->parent; | |
6345 | ||
6346 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6347 | event->hw.itrace_started) | |
6348 | return; | |
6349 | ||
ec0d7729 AS |
6350 | rec.header.type = PERF_RECORD_ITRACE_START; |
6351 | rec.header.misc = 0; | |
6352 | rec.header.size = sizeof(rec); | |
6353 | rec.pid = perf_event_pid(event, current); | |
6354 | rec.tid = perf_event_tid(event, current); | |
6355 | ||
6356 | perf_event_header__init_id(&rec.header, &sample, event); | |
6357 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6358 | ||
6359 | if (ret) | |
6360 | return; | |
6361 | ||
6362 | perf_output_put(&handle, rec); | |
6363 | perf_event__output_id_sample(event, &handle, &sample); | |
6364 | ||
6365 | perf_output_end(&handle); | |
6366 | } | |
6367 | ||
f6c7d5fe | 6368 | /* |
cdd6c482 | 6369 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6370 | */ |
6371 | ||
a8b0ca17 | 6372 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6373 | int throttle, struct perf_sample_data *data, |
6374 | struct pt_regs *regs) | |
f6c7d5fe | 6375 | { |
cdd6c482 IM |
6376 | int events = atomic_read(&event->event_limit); |
6377 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6378 | u64 seq; |
79f14641 PZ |
6379 | int ret = 0; |
6380 | ||
96398826 PZ |
6381 | /* |
6382 | * Non-sampling counters might still use the PMI to fold short | |
6383 | * hardware counters, ignore those. | |
6384 | */ | |
6385 | if (unlikely(!is_sampling_event(event))) | |
6386 | return 0; | |
6387 | ||
e050e3f0 SE |
6388 | seq = __this_cpu_read(perf_throttled_seq); |
6389 | if (seq != hwc->interrupts_seq) { | |
6390 | hwc->interrupts_seq = seq; | |
6391 | hwc->interrupts = 1; | |
6392 | } else { | |
6393 | hwc->interrupts++; | |
6394 | if (unlikely(throttle | |
6395 | && hwc->interrupts >= max_samples_per_tick)) { | |
6396 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6397 | hwc->interrupts = MAX_INTERRUPTS; |
6398 | perf_log_throttle(event, 0); | |
d84153d6 | 6399 | tick_nohz_full_kick(); |
a78ac325 PZ |
6400 | ret = 1; |
6401 | } | |
e050e3f0 | 6402 | } |
60db5e09 | 6403 | |
cdd6c482 | 6404 | if (event->attr.freq) { |
def0a9b2 | 6405 | u64 now = perf_clock(); |
abd50713 | 6406 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6407 | |
abd50713 | 6408 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6409 | |
abd50713 | 6410 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6411 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6412 | } |
6413 | ||
2023b359 PZ |
6414 | /* |
6415 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6416 | * events |
2023b359 PZ |
6417 | */ |
6418 | ||
cdd6c482 IM |
6419 | event->pending_kill = POLL_IN; |
6420 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6421 | ret = 1; |
cdd6c482 | 6422 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6423 | event->pending_disable = 1; |
6424 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6425 | } |
6426 | ||
453f19ee | 6427 | if (event->overflow_handler) |
a8b0ca17 | 6428 | event->overflow_handler(event, data, regs); |
453f19ee | 6429 | else |
a8b0ca17 | 6430 | perf_event_output(event, data, regs); |
453f19ee | 6431 | |
fed66e2c | 6432 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6433 | event->pending_wakeup = 1; |
6434 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6435 | } |
6436 | ||
79f14641 | 6437 | return ret; |
f6c7d5fe PZ |
6438 | } |
6439 | ||
a8b0ca17 | 6440 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6441 | struct perf_sample_data *data, |
6442 | struct pt_regs *regs) | |
850bc73f | 6443 | { |
a8b0ca17 | 6444 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6445 | } |
6446 | ||
15dbf27c | 6447 | /* |
cdd6c482 | 6448 | * Generic software event infrastructure |
15dbf27c PZ |
6449 | */ |
6450 | ||
b28ab83c PZ |
6451 | struct swevent_htable { |
6452 | struct swevent_hlist *swevent_hlist; | |
6453 | struct mutex hlist_mutex; | |
6454 | int hlist_refcount; | |
6455 | ||
6456 | /* Recursion avoidance in each contexts */ | |
6457 | int recursion[PERF_NR_CONTEXTS]; | |
6458 | }; | |
6459 | ||
6460 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6461 | ||
7b4b6658 | 6462 | /* |
cdd6c482 IM |
6463 | * We directly increment event->count and keep a second value in |
6464 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6465 | * is kept in the range [-sample_period, 0] so that we can use the |
6466 | * sign as trigger. | |
6467 | */ | |
6468 | ||
ab573844 | 6469 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6470 | { |
cdd6c482 | 6471 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6472 | u64 period = hwc->last_period; |
6473 | u64 nr, offset; | |
6474 | s64 old, val; | |
6475 | ||
6476 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6477 | |
6478 | again: | |
e7850595 | 6479 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6480 | if (val < 0) |
6481 | return 0; | |
15dbf27c | 6482 | |
7b4b6658 PZ |
6483 | nr = div64_u64(period + val, period); |
6484 | offset = nr * period; | |
6485 | val -= offset; | |
e7850595 | 6486 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6487 | goto again; |
15dbf27c | 6488 | |
7b4b6658 | 6489 | return nr; |
15dbf27c PZ |
6490 | } |
6491 | ||
0cff784a | 6492 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6493 | struct perf_sample_data *data, |
5622f295 | 6494 | struct pt_regs *regs) |
15dbf27c | 6495 | { |
cdd6c482 | 6496 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6497 | int throttle = 0; |
15dbf27c | 6498 | |
0cff784a PZ |
6499 | if (!overflow) |
6500 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6501 | |
7b4b6658 PZ |
6502 | if (hwc->interrupts == MAX_INTERRUPTS) |
6503 | return; | |
15dbf27c | 6504 | |
7b4b6658 | 6505 | for (; overflow; overflow--) { |
a8b0ca17 | 6506 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6507 | data, regs)) { |
7b4b6658 PZ |
6508 | /* |
6509 | * We inhibit the overflow from happening when | |
6510 | * hwc->interrupts == MAX_INTERRUPTS. | |
6511 | */ | |
6512 | break; | |
6513 | } | |
cf450a73 | 6514 | throttle = 1; |
7b4b6658 | 6515 | } |
15dbf27c PZ |
6516 | } |
6517 | ||
a4eaf7f1 | 6518 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6519 | struct perf_sample_data *data, |
5622f295 | 6520 | struct pt_regs *regs) |
7b4b6658 | 6521 | { |
cdd6c482 | 6522 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6523 | |
e7850595 | 6524 | local64_add(nr, &event->count); |
d6d020e9 | 6525 | |
0cff784a PZ |
6526 | if (!regs) |
6527 | return; | |
6528 | ||
6c7e550f | 6529 | if (!is_sampling_event(event)) |
7b4b6658 | 6530 | return; |
d6d020e9 | 6531 | |
5d81e5cf AV |
6532 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6533 | data->period = nr; | |
6534 | return perf_swevent_overflow(event, 1, data, regs); | |
6535 | } else | |
6536 | data->period = event->hw.last_period; | |
6537 | ||
0cff784a | 6538 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6539 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6540 | |
e7850595 | 6541 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6542 | return; |
df1a132b | 6543 | |
a8b0ca17 | 6544 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6545 | } |
6546 | ||
f5ffe02e FW |
6547 | static int perf_exclude_event(struct perf_event *event, |
6548 | struct pt_regs *regs) | |
6549 | { | |
a4eaf7f1 | 6550 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6551 | return 1; |
a4eaf7f1 | 6552 | |
f5ffe02e FW |
6553 | if (regs) { |
6554 | if (event->attr.exclude_user && user_mode(regs)) | |
6555 | return 1; | |
6556 | ||
6557 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6558 | return 1; | |
6559 | } | |
6560 | ||
6561 | return 0; | |
6562 | } | |
6563 | ||
cdd6c482 | 6564 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6565 | enum perf_type_id type, |
6fb2915d LZ |
6566 | u32 event_id, |
6567 | struct perf_sample_data *data, | |
6568 | struct pt_regs *regs) | |
15dbf27c | 6569 | { |
cdd6c482 | 6570 | if (event->attr.type != type) |
a21ca2ca | 6571 | return 0; |
f5ffe02e | 6572 | |
cdd6c482 | 6573 | if (event->attr.config != event_id) |
15dbf27c PZ |
6574 | return 0; |
6575 | ||
f5ffe02e FW |
6576 | if (perf_exclude_event(event, regs)) |
6577 | return 0; | |
15dbf27c PZ |
6578 | |
6579 | return 1; | |
6580 | } | |
6581 | ||
76e1d904 FW |
6582 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6583 | { | |
6584 | u64 val = event_id | (type << 32); | |
6585 | ||
6586 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6587 | } | |
6588 | ||
49f135ed FW |
6589 | static inline struct hlist_head * |
6590 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6591 | { |
49f135ed FW |
6592 | u64 hash = swevent_hash(type, event_id); |
6593 | ||
6594 | return &hlist->heads[hash]; | |
6595 | } | |
76e1d904 | 6596 | |
49f135ed FW |
6597 | /* For the read side: events when they trigger */ |
6598 | static inline struct hlist_head * | |
b28ab83c | 6599 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6600 | { |
6601 | struct swevent_hlist *hlist; | |
76e1d904 | 6602 | |
b28ab83c | 6603 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6604 | if (!hlist) |
6605 | return NULL; | |
6606 | ||
49f135ed FW |
6607 | return __find_swevent_head(hlist, type, event_id); |
6608 | } | |
6609 | ||
6610 | /* For the event head insertion and removal in the hlist */ | |
6611 | static inline struct hlist_head * | |
b28ab83c | 6612 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6613 | { |
6614 | struct swevent_hlist *hlist; | |
6615 | u32 event_id = event->attr.config; | |
6616 | u64 type = event->attr.type; | |
6617 | ||
6618 | /* | |
6619 | * Event scheduling is always serialized against hlist allocation | |
6620 | * and release. Which makes the protected version suitable here. | |
6621 | * The context lock guarantees that. | |
6622 | */ | |
b28ab83c | 6623 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6624 | lockdep_is_held(&event->ctx->lock)); |
6625 | if (!hlist) | |
6626 | return NULL; | |
6627 | ||
6628 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6629 | } |
6630 | ||
6631 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6632 | u64 nr, |
76e1d904 FW |
6633 | struct perf_sample_data *data, |
6634 | struct pt_regs *regs) | |
15dbf27c | 6635 | { |
4a32fea9 | 6636 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6637 | struct perf_event *event; |
76e1d904 | 6638 | struct hlist_head *head; |
15dbf27c | 6639 | |
76e1d904 | 6640 | rcu_read_lock(); |
b28ab83c | 6641 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6642 | if (!head) |
6643 | goto end; | |
6644 | ||
b67bfe0d | 6645 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6646 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6647 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6648 | } |
76e1d904 FW |
6649 | end: |
6650 | rcu_read_unlock(); | |
15dbf27c PZ |
6651 | } |
6652 | ||
86038c5e PZI |
6653 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6654 | ||
4ed7c92d | 6655 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6656 | { |
4a32fea9 | 6657 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6658 | |
b28ab83c | 6659 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6660 | } |
645e8cc0 | 6661 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6662 | |
fa9f90be | 6663 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6664 | { |
4a32fea9 | 6665 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6666 | |
b28ab83c | 6667 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6668 | } |
15dbf27c | 6669 | |
86038c5e | 6670 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6671 | { |
a4234bfc | 6672 | struct perf_sample_data data; |
4ed7c92d | 6673 | |
86038c5e | 6674 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6675 | return; |
a4234bfc | 6676 | |
fd0d000b | 6677 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6678 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6679 | } |
6680 | ||
6681 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6682 | { | |
6683 | int rctx; | |
6684 | ||
6685 | preempt_disable_notrace(); | |
6686 | rctx = perf_swevent_get_recursion_context(); | |
6687 | if (unlikely(rctx < 0)) | |
6688 | goto fail; | |
6689 | ||
6690 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6691 | |
6692 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6693 | fail: |
1c024eca | 6694 | preempt_enable_notrace(); |
b8e83514 PZ |
6695 | } |
6696 | ||
cdd6c482 | 6697 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6698 | { |
15dbf27c PZ |
6699 | } |
6700 | ||
a4eaf7f1 | 6701 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6702 | { |
4a32fea9 | 6703 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6704 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6705 | struct hlist_head *head; |
6706 | ||
6c7e550f | 6707 | if (is_sampling_event(event)) { |
7b4b6658 | 6708 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6709 | perf_swevent_set_period(event); |
7b4b6658 | 6710 | } |
76e1d904 | 6711 | |
a4eaf7f1 PZ |
6712 | hwc->state = !(flags & PERF_EF_START); |
6713 | ||
b28ab83c | 6714 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6715 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6716 | return -EINVAL; |
6717 | ||
6718 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6719 | perf_event_update_userpage(event); |
76e1d904 | 6720 | |
15dbf27c PZ |
6721 | return 0; |
6722 | } | |
6723 | ||
a4eaf7f1 | 6724 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6725 | { |
76e1d904 | 6726 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6727 | } |
6728 | ||
a4eaf7f1 | 6729 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6730 | { |
a4eaf7f1 | 6731 | event->hw.state = 0; |
d6d020e9 | 6732 | } |
aa9c4c0f | 6733 | |
a4eaf7f1 | 6734 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6735 | { |
a4eaf7f1 | 6736 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6737 | } |
6738 | ||
49f135ed FW |
6739 | /* Deref the hlist from the update side */ |
6740 | static inline struct swevent_hlist * | |
b28ab83c | 6741 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6742 | { |
b28ab83c PZ |
6743 | return rcu_dereference_protected(swhash->swevent_hlist, |
6744 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6745 | } |
6746 | ||
b28ab83c | 6747 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6748 | { |
b28ab83c | 6749 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6750 | |
49f135ed | 6751 | if (!hlist) |
76e1d904 FW |
6752 | return; |
6753 | ||
70691d4a | 6754 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6755 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6756 | } |
6757 | ||
6758 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6759 | { | |
b28ab83c | 6760 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6761 | |
b28ab83c | 6762 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6763 | |
b28ab83c PZ |
6764 | if (!--swhash->hlist_refcount) |
6765 | swevent_hlist_release(swhash); | |
76e1d904 | 6766 | |
b28ab83c | 6767 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6768 | } |
6769 | ||
6770 | static void swevent_hlist_put(struct perf_event *event) | |
6771 | { | |
6772 | int cpu; | |
6773 | ||
76e1d904 FW |
6774 | for_each_possible_cpu(cpu) |
6775 | swevent_hlist_put_cpu(event, cpu); | |
6776 | } | |
6777 | ||
6778 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6779 | { | |
b28ab83c | 6780 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6781 | int err = 0; |
6782 | ||
b28ab83c | 6783 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6784 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6785 | struct swevent_hlist *hlist; |
6786 | ||
6787 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6788 | if (!hlist) { | |
6789 | err = -ENOMEM; | |
6790 | goto exit; | |
6791 | } | |
b28ab83c | 6792 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6793 | } |
b28ab83c | 6794 | swhash->hlist_refcount++; |
9ed6060d | 6795 | exit: |
b28ab83c | 6796 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6797 | |
6798 | return err; | |
6799 | } | |
6800 | ||
6801 | static int swevent_hlist_get(struct perf_event *event) | |
6802 | { | |
6803 | int err; | |
6804 | int cpu, failed_cpu; | |
6805 | ||
76e1d904 FW |
6806 | get_online_cpus(); |
6807 | for_each_possible_cpu(cpu) { | |
6808 | err = swevent_hlist_get_cpu(event, cpu); | |
6809 | if (err) { | |
6810 | failed_cpu = cpu; | |
6811 | goto fail; | |
6812 | } | |
6813 | } | |
6814 | put_online_cpus(); | |
6815 | ||
6816 | return 0; | |
9ed6060d | 6817 | fail: |
76e1d904 FW |
6818 | for_each_possible_cpu(cpu) { |
6819 | if (cpu == failed_cpu) | |
6820 | break; | |
6821 | swevent_hlist_put_cpu(event, cpu); | |
6822 | } | |
6823 | ||
6824 | put_online_cpus(); | |
6825 | return err; | |
6826 | } | |
6827 | ||
c5905afb | 6828 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6829 | |
b0a873eb PZ |
6830 | static void sw_perf_event_destroy(struct perf_event *event) |
6831 | { | |
6832 | u64 event_id = event->attr.config; | |
95476b64 | 6833 | |
b0a873eb PZ |
6834 | WARN_ON(event->parent); |
6835 | ||
c5905afb | 6836 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6837 | swevent_hlist_put(event); |
6838 | } | |
6839 | ||
6840 | static int perf_swevent_init(struct perf_event *event) | |
6841 | { | |
8176cced | 6842 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6843 | |
6844 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6845 | return -ENOENT; | |
6846 | ||
2481c5fa SE |
6847 | /* |
6848 | * no branch sampling for software events | |
6849 | */ | |
6850 | if (has_branch_stack(event)) | |
6851 | return -EOPNOTSUPP; | |
6852 | ||
b0a873eb PZ |
6853 | switch (event_id) { |
6854 | case PERF_COUNT_SW_CPU_CLOCK: | |
6855 | case PERF_COUNT_SW_TASK_CLOCK: | |
6856 | return -ENOENT; | |
6857 | ||
6858 | default: | |
6859 | break; | |
6860 | } | |
6861 | ||
ce677831 | 6862 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6863 | return -ENOENT; |
6864 | ||
6865 | if (!event->parent) { | |
6866 | int err; | |
6867 | ||
6868 | err = swevent_hlist_get(event); | |
6869 | if (err) | |
6870 | return err; | |
6871 | ||
c5905afb | 6872 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6873 | event->destroy = sw_perf_event_destroy; |
6874 | } | |
6875 | ||
6876 | return 0; | |
6877 | } | |
6878 | ||
6879 | static struct pmu perf_swevent = { | |
89a1e187 | 6880 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6881 | |
34f43927 PZ |
6882 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6883 | ||
b0a873eb | 6884 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6885 | .add = perf_swevent_add, |
6886 | .del = perf_swevent_del, | |
6887 | .start = perf_swevent_start, | |
6888 | .stop = perf_swevent_stop, | |
1c024eca | 6889 | .read = perf_swevent_read, |
1c024eca PZ |
6890 | }; |
6891 | ||
b0a873eb PZ |
6892 | #ifdef CONFIG_EVENT_TRACING |
6893 | ||
1c024eca PZ |
6894 | static int perf_tp_filter_match(struct perf_event *event, |
6895 | struct perf_sample_data *data) | |
6896 | { | |
6897 | void *record = data->raw->data; | |
6898 | ||
b71b437e PZ |
6899 | /* only top level events have filters set */ |
6900 | if (event->parent) | |
6901 | event = event->parent; | |
6902 | ||
1c024eca PZ |
6903 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6904 | return 1; | |
6905 | return 0; | |
6906 | } | |
6907 | ||
6908 | static int perf_tp_event_match(struct perf_event *event, | |
6909 | struct perf_sample_data *data, | |
6910 | struct pt_regs *regs) | |
6911 | { | |
a0f7d0f7 FW |
6912 | if (event->hw.state & PERF_HES_STOPPED) |
6913 | return 0; | |
580d607c PZ |
6914 | /* |
6915 | * All tracepoints are from kernel-space. | |
6916 | */ | |
6917 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6918 | return 0; |
6919 | ||
6920 | if (!perf_tp_filter_match(event, data)) | |
6921 | return 0; | |
6922 | ||
6923 | return 1; | |
6924 | } | |
6925 | ||
6926 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6927 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6928 | struct task_struct *task) | |
95476b64 FW |
6929 | { |
6930 | struct perf_sample_data data; | |
1c024eca | 6931 | struct perf_event *event; |
1c024eca | 6932 | |
95476b64 FW |
6933 | struct perf_raw_record raw = { |
6934 | .size = entry_size, | |
6935 | .data = record, | |
6936 | }; | |
6937 | ||
fd0d000b | 6938 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6939 | data.raw = &raw; |
6940 | ||
b67bfe0d | 6941 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6942 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6943 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6944 | } |
ecc55f84 | 6945 | |
e6dab5ff AV |
6946 | /* |
6947 | * If we got specified a target task, also iterate its context and | |
6948 | * deliver this event there too. | |
6949 | */ | |
6950 | if (task && task != current) { | |
6951 | struct perf_event_context *ctx; | |
6952 | struct trace_entry *entry = record; | |
6953 | ||
6954 | rcu_read_lock(); | |
6955 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6956 | if (!ctx) | |
6957 | goto unlock; | |
6958 | ||
6959 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6960 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6961 | continue; | |
6962 | if (event->attr.config != entry->type) | |
6963 | continue; | |
6964 | if (perf_tp_event_match(event, &data, regs)) | |
6965 | perf_swevent_event(event, count, &data, regs); | |
6966 | } | |
6967 | unlock: | |
6968 | rcu_read_unlock(); | |
6969 | } | |
6970 | ||
ecc55f84 | 6971 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6972 | } |
6973 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6974 | ||
cdd6c482 | 6975 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6976 | { |
1c024eca | 6977 | perf_trace_destroy(event); |
e077df4f PZ |
6978 | } |
6979 | ||
b0a873eb | 6980 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6981 | { |
76e1d904 FW |
6982 | int err; |
6983 | ||
b0a873eb PZ |
6984 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6985 | return -ENOENT; | |
6986 | ||
2481c5fa SE |
6987 | /* |
6988 | * no branch sampling for tracepoint events | |
6989 | */ | |
6990 | if (has_branch_stack(event)) | |
6991 | return -EOPNOTSUPP; | |
6992 | ||
1c024eca PZ |
6993 | err = perf_trace_init(event); |
6994 | if (err) | |
b0a873eb | 6995 | return err; |
e077df4f | 6996 | |
cdd6c482 | 6997 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6998 | |
b0a873eb PZ |
6999 | return 0; |
7000 | } | |
7001 | ||
7002 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
7003 | .task_ctx_nr = perf_sw_context, |
7004 | ||
b0a873eb | 7005 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
7006 | .add = perf_trace_add, |
7007 | .del = perf_trace_del, | |
7008 | .start = perf_swevent_start, | |
7009 | .stop = perf_swevent_stop, | |
b0a873eb | 7010 | .read = perf_swevent_read, |
b0a873eb PZ |
7011 | }; |
7012 | ||
7013 | static inline void perf_tp_register(void) | |
7014 | { | |
2e80a82a | 7015 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 7016 | } |
6fb2915d LZ |
7017 | |
7018 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7019 | { | |
7020 | char *filter_str; | |
7021 | int ret; | |
7022 | ||
7023 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7024 | return -EINVAL; | |
7025 | ||
7026 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7027 | if (IS_ERR(filter_str)) | |
7028 | return PTR_ERR(filter_str); | |
7029 | ||
7030 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
7031 | ||
7032 | kfree(filter_str); | |
7033 | return ret; | |
7034 | } | |
7035 | ||
7036 | static void perf_event_free_filter(struct perf_event *event) | |
7037 | { | |
7038 | ftrace_profile_free_filter(event); | |
7039 | } | |
7040 | ||
2541517c AS |
7041 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7042 | { | |
7043 | struct bpf_prog *prog; | |
7044 | ||
7045 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7046 | return -EINVAL; | |
7047 | ||
7048 | if (event->tp_event->prog) | |
7049 | return -EEXIST; | |
7050 | ||
04a22fae WN |
7051 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7052 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7053 | return -EINVAL; |
7054 | ||
7055 | prog = bpf_prog_get(prog_fd); | |
7056 | if (IS_ERR(prog)) | |
7057 | return PTR_ERR(prog); | |
7058 | ||
6c373ca8 | 7059 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7060 | /* valid fd, but invalid bpf program type */ |
7061 | bpf_prog_put(prog); | |
7062 | return -EINVAL; | |
7063 | } | |
7064 | ||
7065 | event->tp_event->prog = prog; | |
7066 | ||
7067 | return 0; | |
7068 | } | |
7069 | ||
7070 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7071 | { | |
7072 | struct bpf_prog *prog; | |
7073 | ||
7074 | if (!event->tp_event) | |
7075 | return; | |
7076 | ||
7077 | prog = event->tp_event->prog; | |
7078 | if (prog) { | |
7079 | event->tp_event->prog = NULL; | |
7080 | bpf_prog_put(prog); | |
7081 | } | |
7082 | } | |
7083 | ||
e077df4f | 7084 | #else |
6fb2915d | 7085 | |
b0a873eb | 7086 | static inline void perf_tp_register(void) |
e077df4f | 7087 | { |
e077df4f | 7088 | } |
6fb2915d LZ |
7089 | |
7090 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7091 | { | |
7092 | return -ENOENT; | |
7093 | } | |
7094 | ||
7095 | static void perf_event_free_filter(struct perf_event *event) | |
7096 | { | |
7097 | } | |
7098 | ||
2541517c AS |
7099 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7100 | { | |
7101 | return -ENOENT; | |
7102 | } | |
7103 | ||
7104 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7105 | { | |
7106 | } | |
07b139c8 | 7107 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7108 | |
24f1e32c | 7109 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7110 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7111 | { |
f5ffe02e FW |
7112 | struct perf_sample_data sample; |
7113 | struct pt_regs *regs = data; | |
7114 | ||
fd0d000b | 7115 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7116 | |
a4eaf7f1 | 7117 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7118 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7119 | } |
7120 | #endif | |
7121 | ||
b0a873eb PZ |
7122 | /* |
7123 | * hrtimer based swevent callback | |
7124 | */ | |
f29ac756 | 7125 | |
b0a873eb | 7126 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7127 | { |
b0a873eb PZ |
7128 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7129 | struct perf_sample_data data; | |
7130 | struct pt_regs *regs; | |
7131 | struct perf_event *event; | |
7132 | u64 period; | |
f29ac756 | 7133 | |
b0a873eb | 7134 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7135 | |
7136 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7137 | return HRTIMER_NORESTART; | |
7138 | ||
b0a873eb | 7139 | event->pmu->read(event); |
f344011c | 7140 | |
fd0d000b | 7141 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7142 | regs = get_irq_regs(); |
7143 | ||
7144 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7145 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7146 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7147 | ret = HRTIMER_NORESTART; |
7148 | } | |
24f1e32c | 7149 | |
b0a873eb PZ |
7150 | period = max_t(u64, 10000, event->hw.sample_period); |
7151 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7152 | |
b0a873eb | 7153 | return ret; |
f29ac756 PZ |
7154 | } |
7155 | ||
b0a873eb | 7156 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7157 | { |
b0a873eb | 7158 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7159 | s64 period; |
7160 | ||
7161 | if (!is_sampling_event(event)) | |
7162 | return; | |
f5ffe02e | 7163 | |
5d508e82 FBH |
7164 | period = local64_read(&hwc->period_left); |
7165 | if (period) { | |
7166 | if (period < 0) | |
7167 | period = 10000; | |
fa407f35 | 7168 | |
5d508e82 FBH |
7169 | local64_set(&hwc->period_left, 0); |
7170 | } else { | |
7171 | period = max_t(u64, 10000, hwc->sample_period); | |
7172 | } | |
3497d206 TG |
7173 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7174 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7175 | } |
b0a873eb PZ |
7176 | |
7177 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7178 | { |
b0a873eb PZ |
7179 | struct hw_perf_event *hwc = &event->hw; |
7180 | ||
6c7e550f | 7181 | if (is_sampling_event(event)) { |
b0a873eb | 7182 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7183 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7184 | |
7185 | hrtimer_cancel(&hwc->hrtimer); | |
7186 | } | |
24f1e32c FW |
7187 | } |
7188 | ||
ba3dd36c PZ |
7189 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7190 | { | |
7191 | struct hw_perf_event *hwc = &event->hw; | |
7192 | ||
7193 | if (!is_sampling_event(event)) | |
7194 | return; | |
7195 | ||
7196 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7197 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7198 | ||
7199 | /* | |
7200 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7201 | * mapping and avoid the whole period adjust feedback stuff. | |
7202 | */ | |
7203 | if (event->attr.freq) { | |
7204 | long freq = event->attr.sample_freq; | |
7205 | ||
7206 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7207 | hwc->sample_period = event->attr.sample_period; | |
7208 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7209 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7210 | event->attr.freq = 0; |
7211 | } | |
7212 | } | |
7213 | ||
b0a873eb PZ |
7214 | /* |
7215 | * Software event: cpu wall time clock | |
7216 | */ | |
7217 | ||
7218 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7219 | { |
b0a873eb PZ |
7220 | s64 prev; |
7221 | u64 now; | |
7222 | ||
a4eaf7f1 | 7223 | now = local_clock(); |
b0a873eb PZ |
7224 | prev = local64_xchg(&event->hw.prev_count, now); |
7225 | local64_add(now - prev, &event->count); | |
24f1e32c | 7226 | } |
24f1e32c | 7227 | |
a4eaf7f1 | 7228 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7229 | { |
a4eaf7f1 | 7230 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7231 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7232 | } |
7233 | ||
a4eaf7f1 | 7234 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7235 | { |
b0a873eb PZ |
7236 | perf_swevent_cancel_hrtimer(event); |
7237 | cpu_clock_event_update(event); | |
7238 | } | |
f29ac756 | 7239 | |
a4eaf7f1 PZ |
7240 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7241 | { | |
7242 | if (flags & PERF_EF_START) | |
7243 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7244 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7245 | |
7246 | return 0; | |
7247 | } | |
7248 | ||
7249 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7250 | { | |
7251 | cpu_clock_event_stop(event, flags); | |
7252 | } | |
7253 | ||
b0a873eb PZ |
7254 | static void cpu_clock_event_read(struct perf_event *event) |
7255 | { | |
7256 | cpu_clock_event_update(event); | |
7257 | } | |
f344011c | 7258 | |
b0a873eb PZ |
7259 | static int cpu_clock_event_init(struct perf_event *event) |
7260 | { | |
7261 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7262 | return -ENOENT; | |
7263 | ||
7264 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7265 | return -ENOENT; | |
7266 | ||
2481c5fa SE |
7267 | /* |
7268 | * no branch sampling for software events | |
7269 | */ | |
7270 | if (has_branch_stack(event)) | |
7271 | return -EOPNOTSUPP; | |
7272 | ||
ba3dd36c PZ |
7273 | perf_swevent_init_hrtimer(event); |
7274 | ||
b0a873eb | 7275 | return 0; |
f29ac756 PZ |
7276 | } |
7277 | ||
b0a873eb | 7278 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7279 | .task_ctx_nr = perf_sw_context, |
7280 | ||
34f43927 PZ |
7281 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7282 | ||
b0a873eb | 7283 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7284 | .add = cpu_clock_event_add, |
7285 | .del = cpu_clock_event_del, | |
7286 | .start = cpu_clock_event_start, | |
7287 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7288 | .read = cpu_clock_event_read, |
7289 | }; | |
7290 | ||
7291 | /* | |
7292 | * Software event: task time clock | |
7293 | */ | |
7294 | ||
7295 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7296 | { |
b0a873eb PZ |
7297 | u64 prev; |
7298 | s64 delta; | |
5c92d124 | 7299 | |
b0a873eb PZ |
7300 | prev = local64_xchg(&event->hw.prev_count, now); |
7301 | delta = now - prev; | |
7302 | local64_add(delta, &event->count); | |
7303 | } | |
5c92d124 | 7304 | |
a4eaf7f1 | 7305 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7306 | { |
a4eaf7f1 | 7307 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7308 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7309 | } |
7310 | ||
a4eaf7f1 | 7311 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7312 | { |
7313 | perf_swevent_cancel_hrtimer(event); | |
7314 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7315 | } |
7316 | ||
7317 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7318 | { | |
7319 | if (flags & PERF_EF_START) | |
7320 | task_clock_event_start(event, flags); | |
6a694a60 | 7321 | perf_event_update_userpage(event); |
b0a873eb | 7322 | |
a4eaf7f1 PZ |
7323 | return 0; |
7324 | } | |
7325 | ||
7326 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7327 | { | |
7328 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7329 | } |
7330 | ||
7331 | static void task_clock_event_read(struct perf_event *event) | |
7332 | { | |
768a06e2 PZ |
7333 | u64 now = perf_clock(); |
7334 | u64 delta = now - event->ctx->timestamp; | |
7335 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7336 | |
7337 | task_clock_event_update(event, time); | |
7338 | } | |
7339 | ||
7340 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7341 | { |
b0a873eb PZ |
7342 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7343 | return -ENOENT; | |
7344 | ||
7345 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7346 | return -ENOENT; | |
7347 | ||
2481c5fa SE |
7348 | /* |
7349 | * no branch sampling for software events | |
7350 | */ | |
7351 | if (has_branch_stack(event)) | |
7352 | return -EOPNOTSUPP; | |
7353 | ||
ba3dd36c PZ |
7354 | perf_swevent_init_hrtimer(event); |
7355 | ||
b0a873eb | 7356 | return 0; |
6fb2915d LZ |
7357 | } |
7358 | ||
b0a873eb | 7359 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7360 | .task_ctx_nr = perf_sw_context, |
7361 | ||
34f43927 PZ |
7362 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7363 | ||
b0a873eb | 7364 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7365 | .add = task_clock_event_add, |
7366 | .del = task_clock_event_del, | |
7367 | .start = task_clock_event_start, | |
7368 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7369 | .read = task_clock_event_read, |
7370 | }; | |
6fb2915d | 7371 | |
ad5133b7 | 7372 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7373 | { |
e077df4f | 7374 | } |
6fb2915d | 7375 | |
fbbe0701 SB |
7376 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7377 | { | |
7378 | } | |
7379 | ||
ad5133b7 | 7380 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7381 | { |
ad5133b7 | 7382 | return 0; |
6fb2915d LZ |
7383 | } |
7384 | ||
18ab2cd3 | 7385 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7386 | |
7387 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7388 | { |
fbbe0701 SB |
7389 | __this_cpu_write(nop_txn_flags, flags); |
7390 | ||
7391 | if (flags & ~PERF_PMU_TXN_ADD) | |
7392 | return; | |
7393 | ||
ad5133b7 | 7394 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7395 | } |
7396 | ||
ad5133b7 PZ |
7397 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7398 | { | |
fbbe0701 SB |
7399 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7400 | ||
7401 | __this_cpu_write(nop_txn_flags, 0); | |
7402 | ||
7403 | if (flags & ~PERF_PMU_TXN_ADD) | |
7404 | return 0; | |
7405 | ||
ad5133b7 PZ |
7406 | perf_pmu_enable(pmu); |
7407 | return 0; | |
7408 | } | |
e077df4f | 7409 | |
ad5133b7 | 7410 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7411 | { |
fbbe0701 SB |
7412 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7413 | ||
7414 | __this_cpu_write(nop_txn_flags, 0); | |
7415 | ||
7416 | if (flags & ~PERF_PMU_TXN_ADD) | |
7417 | return; | |
7418 | ||
ad5133b7 | 7419 | perf_pmu_enable(pmu); |
24f1e32c FW |
7420 | } |
7421 | ||
35edc2a5 PZ |
7422 | static int perf_event_idx_default(struct perf_event *event) |
7423 | { | |
c719f560 | 7424 | return 0; |
35edc2a5 PZ |
7425 | } |
7426 | ||
8dc85d54 PZ |
7427 | /* |
7428 | * Ensures all contexts with the same task_ctx_nr have the same | |
7429 | * pmu_cpu_context too. | |
7430 | */ | |
9e317041 | 7431 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7432 | { |
8dc85d54 | 7433 | struct pmu *pmu; |
b326e956 | 7434 | |
8dc85d54 PZ |
7435 | if (ctxn < 0) |
7436 | return NULL; | |
24f1e32c | 7437 | |
8dc85d54 PZ |
7438 | list_for_each_entry(pmu, &pmus, entry) { |
7439 | if (pmu->task_ctx_nr == ctxn) | |
7440 | return pmu->pmu_cpu_context; | |
7441 | } | |
24f1e32c | 7442 | |
8dc85d54 | 7443 | return NULL; |
24f1e32c FW |
7444 | } |
7445 | ||
51676957 | 7446 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7447 | { |
51676957 PZ |
7448 | int cpu; |
7449 | ||
7450 | for_each_possible_cpu(cpu) { | |
7451 | struct perf_cpu_context *cpuctx; | |
7452 | ||
7453 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7454 | ||
3f1f3320 PZ |
7455 | if (cpuctx->unique_pmu == old_pmu) |
7456 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7457 | } |
7458 | } | |
7459 | ||
7460 | static void free_pmu_context(struct pmu *pmu) | |
7461 | { | |
7462 | struct pmu *i; | |
f5ffe02e | 7463 | |
8dc85d54 | 7464 | mutex_lock(&pmus_lock); |
0475f9ea | 7465 | /* |
8dc85d54 | 7466 | * Like a real lame refcount. |
0475f9ea | 7467 | */ |
51676957 PZ |
7468 | list_for_each_entry(i, &pmus, entry) { |
7469 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7470 | update_pmu_context(i, pmu); | |
8dc85d54 | 7471 | goto out; |
51676957 | 7472 | } |
8dc85d54 | 7473 | } |
d6d020e9 | 7474 | |
51676957 | 7475 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7476 | out: |
7477 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7478 | } |
2e80a82a | 7479 | static struct idr pmu_idr; |
d6d020e9 | 7480 | |
abe43400 PZ |
7481 | static ssize_t |
7482 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7483 | { | |
7484 | struct pmu *pmu = dev_get_drvdata(dev); | |
7485 | ||
7486 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7487 | } | |
90826ca7 | 7488 | static DEVICE_ATTR_RO(type); |
abe43400 | 7489 | |
62b85639 SE |
7490 | static ssize_t |
7491 | perf_event_mux_interval_ms_show(struct device *dev, | |
7492 | struct device_attribute *attr, | |
7493 | char *page) | |
7494 | { | |
7495 | struct pmu *pmu = dev_get_drvdata(dev); | |
7496 | ||
7497 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7498 | } | |
7499 | ||
272325c4 PZ |
7500 | static DEFINE_MUTEX(mux_interval_mutex); |
7501 | ||
62b85639 SE |
7502 | static ssize_t |
7503 | perf_event_mux_interval_ms_store(struct device *dev, | |
7504 | struct device_attribute *attr, | |
7505 | const char *buf, size_t count) | |
7506 | { | |
7507 | struct pmu *pmu = dev_get_drvdata(dev); | |
7508 | int timer, cpu, ret; | |
7509 | ||
7510 | ret = kstrtoint(buf, 0, &timer); | |
7511 | if (ret) | |
7512 | return ret; | |
7513 | ||
7514 | if (timer < 1) | |
7515 | return -EINVAL; | |
7516 | ||
7517 | /* same value, noting to do */ | |
7518 | if (timer == pmu->hrtimer_interval_ms) | |
7519 | return count; | |
7520 | ||
272325c4 | 7521 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7522 | pmu->hrtimer_interval_ms = timer; |
7523 | ||
7524 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7525 | get_online_cpus(); |
7526 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7527 | struct perf_cpu_context *cpuctx; |
7528 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7529 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7530 | ||
272325c4 PZ |
7531 | cpu_function_call(cpu, |
7532 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7533 | } |
272325c4 PZ |
7534 | put_online_cpus(); |
7535 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7536 | |
7537 | return count; | |
7538 | } | |
90826ca7 | 7539 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7540 | |
90826ca7 GKH |
7541 | static struct attribute *pmu_dev_attrs[] = { |
7542 | &dev_attr_type.attr, | |
7543 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7544 | NULL, | |
abe43400 | 7545 | }; |
90826ca7 | 7546 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7547 | |
7548 | static int pmu_bus_running; | |
7549 | static struct bus_type pmu_bus = { | |
7550 | .name = "event_source", | |
90826ca7 | 7551 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7552 | }; |
7553 | ||
7554 | static void pmu_dev_release(struct device *dev) | |
7555 | { | |
7556 | kfree(dev); | |
7557 | } | |
7558 | ||
7559 | static int pmu_dev_alloc(struct pmu *pmu) | |
7560 | { | |
7561 | int ret = -ENOMEM; | |
7562 | ||
7563 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7564 | if (!pmu->dev) | |
7565 | goto out; | |
7566 | ||
0c9d42ed | 7567 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7568 | device_initialize(pmu->dev); |
7569 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7570 | if (ret) | |
7571 | goto free_dev; | |
7572 | ||
7573 | dev_set_drvdata(pmu->dev, pmu); | |
7574 | pmu->dev->bus = &pmu_bus; | |
7575 | pmu->dev->release = pmu_dev_release; | |
7576 | ret = device_add(pmu->dev); | |
7577 | if (ret) | |
7578 | goto free_dev; | |
7579 | ||
7580 | out: | |
7581 | return ret; | |
7582 | ||
7583 | free_dev: | |
7584 | put_device(pmu->dev); | |
7585 | goto out; | |
7586 | } | |
7587 | ||
547e9fd7 | 7588 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7589 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7590 | |
03d8e80b | 7591 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7592 | { |
108b02cf | 7593 | int cpu, ret; |
24f1e32c | 7594 | |
b0a873eb | 7595 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7596 | ret = -ENOMEM; |
7597 | pmu->pmu_disable_count = alloc_percpu(int); | |
7598 | if (!pmu->pmu_disable_count) | |
7599 | goto unlock; | |
f29ac756 | 7600 | |
2e80a82a PZ |
7601 | pmu->type = -1; |
7602 | if (!name) | |
7603 | goto skip_type; | |
7604 | pmu->name = name; | |
7605 | ||
7606 | if (type < 0) { | |
0e9c3be2 TH |
7607 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7608 | if (type < 0) { | |
7609 | ret = type; | |
2e80a82a PZ |
7610 | goto free_pdc; |
7611 | } | |
7612 | } | |
7613 | pmu->type = type; | |
7614 | ||
abe43400 PZ |
7615 | if (pmu_bus_running) { |
7616 | ret = pmu_dev_alloc(pmu); | |
7617 | if (ret) | |
7618 | goto free_idr; | |
7619 | } | |
7620 | ||
2e80a82a | 7621 | skip_type: |
8dc85d54 PZ |
7622 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7623 | if (pmu->pmu_cpu_context) | |
7624 | goto got_cpu_context; | |
f29ac756 | 7625 | |
c4814202 | 7626 | ret = -ENOMEM; |
108b02cf PZ |
7627 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7628 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7629 | goto free_dev; |
f344011c | 7630 | |
108b02cf PZ |
7631 | for_each_possible_cpu(cpu) { |
7632 | struct perf_cpu_context *cpuctx; | |
7633 | ||
7634 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7635 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7636 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7637 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7638 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7639 | |
272325c4 | 7640 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7641 | |
3f1f3320 | 7642 | cpuctx->unique_pmu = pmu; |
108b02cf | 7643 | } |
76e1d904 | 7644 | |
8dc85d54 | 7645 | got_cpu_context: |
ad5133b7 PZ |
7646 | if (!pmu->start_txn) { |
7647 | if (pmu->pmu_enable) { | |
7648 | /* | |
7649 | * If we have pmu_enable/pmu_disable calls, install | |
7650 | * transaction stubs that use that to try and batch | |
7651 | * hardware accesses. | |
7652 | */ | |
7653 | pmu->start_txn = perf_pmu_start_txn; | |
7654 | pmu->commit_txn = perf_pmu_commit_txn; | |
7655 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7656 | } else { | |
fbbe0701 | 7657 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7658 | pmu->commit_txn = perf_pmu_nop_int; |
7659 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7660 | } |
5c92d124 | 7661 | } |
15dbf27c | 7662 | |
ad5133b7 PZ |
7663 | if (!pmu->pmu_enable) { |
7664 | pmu->pmu_enable = perf_pmu_nop_void; | |
7665 | pmu->pmu_disable = perf_pmu_nop_void; | |
7666 | } | |
7667 | ||
35edc2a5 PZ |
7668 | if (!pmu->event_idx) |
7669 | pmu->event_idx = perf_event_idx_default; | |
7670 | ||
b0a873eb | 7671 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7672 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7673 | ret = 0; |
7674 | unlock: | |
b0a873eb PZ |
7675 | mutex_unlock(&pmus_lock); |
7676 | ||
33696fc0 | 7677 | return ret; |
108b02cf | 7678 | |
abe43400 PZ |
7679 | free_dev: |
7680 | device_del(pmu->dev); | |
7681 | put_device(pmu->dev); | |
7682 | ||
2e80a82a PZ |
7683 | free_idr: |
7684 | if (pmu->type >= PERF_TYPE_MAX) | |
7685 | idr_remove(&pmu_idr, pmu->type); | |
7686 | ||
108b02cf PZ |
7687 | free_pdc: |
7688 | free_percpu(pmu->pmu_disable_count); | |
7689 | goto unlock; | |
f29ac756 | 7690 | } |
c464c76e | 7691 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7692 | |
b0a873eb | 7693 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7694 | { |
b0a873eb PZ |
7695 | mutex_lock(&pmus_lock); |
7696 | list_del_rcu(&pmu->entry); | |
7697 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7698 | |
0475f9ea | 7699 | /* |
cde8e884 PZ |
7700 | * We dereference the pmu list under both SRCU and regular RCU, so |
7701 | * synchronize against both of those. | |
0475f9ea | 7702 | */ |
b0a873eb | 7703 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7704 | synchronize_rcu(); |
d6d020e9 | 7705 | |
33696fc0 | 7706 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7707 | if (pmu->type >= PERF_TYPE_MAX) |
7708 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7709 | device_del(pmu->dev); |
7710 | put_device(pmu->dev); | |
51676957 | 7711 | free_pmu_context(pmu); |
b0a873eb | 7712 | } |
c464c76e | 7713 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7714 | |
cc34b98b MR |
7715 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7716 | { | |
ccd41c86 | 7717 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7718 | int ret; |
7719 | ||
7720 | if (!try_module_get(pmu->module)) | |
7721 | return -ENODEV; | |
ccd41c86 PZ |
7722 | |
7723 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7724 | /* |
7725 | * This ctx->mutex can nest when we're called through | |
7726 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7727 | */ | |
7728 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7729 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7730 | BUG_ON(!ctx); |
7731 | } | |
7732 | ||
cc34b98b MR |
7733 | event->pmu = pmu; |
7734 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7735 | |
7736 | if (ctx) | |
7737 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7738 | ||
cc34b98b MR |
7739 | if (ret) |
7740 | module_put(pmu->module); | |
7741 | ||
7742 | return ret; | |
7743 | } | |
7744 | ||
18ab2cd3 | 7745 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7746 | { |
7747 | struct pmu *pmu = NULL; | |
7748 | int idx; | |
940c5b29 | 7749 | int ret; |
b0a873eb PZ |
7750 | |
7751 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7752 | |
7753 | rcu_read_lock(); | |
7754 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7755 | rcu_read_unlock(); | |
940c5b29 | 7756 | if (pmu) { |
cc34b98b | 7757 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7758 | if (ret) |
7759 | pmu = ERR_PTR(ret); | |
2e80a82a | 7760 | goto unlock; |
940c5b29 | 7761 | } |
2e80a82a | 7762 | |
b0a873eb | 7763 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7764 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7765 | if (!ret) |
e5f4d339 | 7766 | goto unlock; |
76e1d904 | 7767 | |
b0a873eb PZ |
7768 | if (ret != -ENOENT) { |
7769 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7770 | goto unlock; |
f344011c | 7771 | } |
5c92d124 | 7772 | } |
e5f4d339 PZ |
7773 | pmu = ERR_PTR(-ENOENT); |
7774 | unlock: | |
b0a873eb | 7775 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7776 | |
4aeb0b42 | 7777 | return pmu; |
5c92d124 IM |
7778 | } |
7779 | ||
4beb31f3 FW |
7780 | static void account_event_cpu(struct perf_event *event, int cpu) |
7781 | { | |
7782 | if (event->parent) | |
7783 | return; | |
7784 | ||
4beb31f3 FW |
7785 | if (is_cgroup_event(event)) |
7786 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7787 | } | |
7788 | ||
766d6c07 FW |
7789 | static void account_event(struct perf_event *event) |
7790 | { | |
25432ae9 PZ |
7791 | bool inc = false; |
7792 | ||
4beb31f3 FW |
7793 | if (event->parent) |
7794 | return; | |
7795 | ||
766d6c07 | 7796 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7797 | inc = true; |
766d6c07 FW |
7798 | if (event->attr.mmap || event->attr.mmap_data) |
7799 | atomic_inc(&nr_mmap_events); | |
7800 | if (event->attr.comm) | |
7801 | atomic_inc(&nr_comm_events); | |
7802 | if (event->attr.task) | |
7803 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7804 | if (event->attr.freq) { |
7805 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7806 | tick_nohz_full_kick_all(); | |
7807 | } | |
45ac1403 AH |
7808 | if (event->attr.context_switch) { |
7809 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7810 | inc = true; |
45ac1403 | 7811 | } |
4beb31f3 | 7812 | if (has_branch_stack(event)) |
25432ae9 | 7813 | inc = true; |
4beb31f3 | 7814 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7815 | inc = true; |
7816 | ||
9107c89e PZ |
7817 | if (inc) { |
7818 | if (atomic_inc_not_zero(&perf_sched_count)) | |
7819 | goto enabled; | |
7820 | ||
7821 | mutex_lock(&perf_sched_mutex); | |
7822 | if (!atomic_read(&perf_sched_count)) { | |
7823 | static_branch_enable(&perf_sched_events); | |
7824 | /* | |
7825 | * Guarantee that all CPUs observe they key change and | |
7826 | * call the perf scheduling hooks before proceeding to | |
7827 | * install events that need them. | |
7828 | */ | |
7829 | synchronize_sched(); | |
7830 | } | |
7831 | /* | |
7832 | * Now that we have waited for the sync_sched(), allow further | |
7833 | * increments to by-pass the mutex. | |
7834 | */ | |
7835 | atomic_inc(&perf_sched_count); | |
7836 | mutex_unlock(&perf_sched_mutex); | |
7837 | } | |
7838 | enabled: | |
4beb31f3 FW |
7839 | |
7840 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7841 | } |
7842 | ||
0793a61d | 7843 | /* |
cdd6c482 | 7844 | * Allocate and initialize a event structure |
0793a61d | 7845 | */ |
cdd6c482 | 7846 | static struct perf_event * |
c3f00c70 | 7847 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7848 | struct task_struct *task, |
7849 | struct perf_event *group_leader, | |
7850 | struct perf_event *parent_event, | |
4dc0da86 | 7851 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7852 | void *context, int cgroup_fd) |
0793a61d | 7853 | { |
51b0fe39 | 7854 | struct pmu *pmu; |
cdd6c482 IM |
7855 | struct perf_event *event; |
7856 | struct hw_perf_event *hwc; | |
90983b16 | 7857 | long err = -EINVAL; |
0793a61d | 7858 | |
66832eb4 ON |
7859 | if ((unsigned)cpu >= nr_cpu_ids) { |
7860 | if (!task || cpu != -1) | |
7861 | return ERR_PTR(-EINVAL); | |
7862 | } | |
7863 | ||
c3f00c70 | 7864 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7865 | if (!event) |
d5d2bc0d | 7866 | return ERR_PTR(-ENOMEM); |
0793a61d | 7867 | |
04289bb9 | 7868 | /* |
cdd6c482 | 7869 | * Single events are their own group leaders, with an |
04289bb9 IM |
7870 | * empty sibling list: |
7871 | */ | |
7872 | if (!group_leader) | |
cdd6c482 | 7873 | group_leader = event; |
04289bb9 | 7874 | |
cdd6c482 IM |
7875 | mutex_init(&event->child_mutex); |
7876 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7877 | |
cdd6c482 IM |
7878 | INIT_LIST_HEAD(&event->group_entry); |
7879 | INIT_LIST_HEAD(&event->event_entry); | |
7880 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7881 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7882 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7883 | INIT_HLIST_NODE(&event->hlist_entry); |
7884 | ||
10c6db11 | 7885 | |
cdd6c482 | 7886 | init_waitqueue_head(&event->waitq); |
e360adbe | 7887 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7888 | |
cdd6c482 | 7889 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7890 | |
a6fa941d | 7891 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7892 | event->cpu = cpu; |
7893 | event->attr = *attr; | |
7894 | event->group_leader = group_leader; | |
7895 | event->pmu = NULL; | |
cdd6c482 | 7896 | event->oncpu = -1; |
a96bbc16 | 7897 | |
cdd6c482 | 7898 | event->parent = parent_event; |
b84fbc9f | 7899 | |
17cf22c3 | 7900 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7901 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7902 | |
cdd6c482 | 7903 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7904 | |
d580ff86 PZ |
7905 | if (task) { |
7906 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7907 | /* |
50f16a8b PZ |
7908 | * XXX pmu::event_init needs to know what task to account to |
7909 | * and we cannot use the ctx information because we need the | |
7910 | * pmu before we get a ctx. | |
d580ff86 | 7911 | */ |
50f16a8b | 7912 | event->hw.target = task; |
d580ff86 PZ |
7913 | } |
7914 | ||
34f43927 PZ |
7915 | event->clock = &local_clock; |
7916 | if (parent_event) | |
7917 | event->clock = parent_event->clock; | |
7918 | ||
4dc0da86 | 7919 | if (!overflow_handler && parent_event) { |
b326e956 | 7920 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7921 | context = parent_event->overflow_handler_context; |
7922 | } | |
66832eb4 | 7923 | |
b326e956 | 7924 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7925 | event->overflow_handler_context = context; |
97eaf530 | 7926 | |
0231bb53 | 7927 | perf_event__state_init(event); |
a86ed508 | 7928 | |
4aeb0b42 | 7929 | pmu = NULL; |
b8e83514 | 7930 | |
cdd6c482 | 7931 | hwc = &event->hw; |
bd2b5b12 | 7932 | hwc->sample_period = attr->sample_period; |
0d48696f | 7933 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7934 | hwc->sample_period = 1; |
eced1dfc | 7935 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7936 | |
e7850595 | 7937 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7938 | |
2023b359 | 7939 | /* |
cdd6c482 | 7940 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7941 | */ |
3dab77fb | 7942 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7943 | goto err_ns; |
a46a2300 YZ |
7944 | |
7945 | if (!has_branch_stack(event)) | |
7946 | event->attr.branch_sample_type = 0; | |
2023b359 | 7947 | |
79dff51e MF |
7948 | if (cgroup_fd != -1) { |
7949 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7950 | if (err) | |
7951 | goto err_ns; | |
7952 | } | |
7953 | ||
b0a873eb | 7954 | pmu = perf_init_event(event); |
4aeb0b42 | 7955 | if (!pmu) |
90983b16 FW |
7956 | goto err_ns; |
7957 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7958 | err = PTR_ERR(pmu); |
90983b16 | 7959 | goto err_ns; |
621a01ea | 7960 | } |
d5d2bc0d | 7961 | |
bed5b25a AS |
7962 | err = exclusive_event_init(event); |
7963 | if (err) | |
7964 | goto err_pmu; | |
7965 | ||
cdd6c482 | 7966 | if (!event->parent) { |
927c7a9e FW |
7967 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7968 | err = get_callchain_buffers(); | |
90983b16 | 7969 | if (err) |
bed5b25a | 7970 | goto err_per_task; |
d010b332 | 7971 | } |
f344011c | 7972 | } |
9ee318a7 | 7973 | |
cdd6c482 | 7974 | return event; |
90983b16 | 7975 | |
bed5b25a AS |
7976 | err_per_task: |
7977 | exclusive_event_destroy(event); | |
7978 | ||
90983b16 FW |
7979 | err_pmu: |
7980 | if (event->destroy) | |
7981 | event->destroy(event); | |
c464c76e | 7982 | module_put(pmu->module); |
90983b16 | 7983 | err_ns: |
79dff51e MF |
7984 | if (is_cgroup_event(event)) |
7985 | perf_detach_cgroup(event); | |
90983b16 FW |
7986 | if (event->ns) |
7987 | put_pid_ns(event->ns); | |
7988 | kfree(event); | |
7989 | ||
7990 | return ERR_PTR(err); | |
0793a61d TG |
7991 | } |
7992 | ||
cdd6c482 IM |
7993 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7994 | struct perf_event_attr *attr) | |
974802ea | 7995 | { |
974802ea | 7996 | u32 size; |
cdf8073d | 7997 | int ret; |
974802ea PZ |
7998 | |
7999 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
8000 | return -EFAULT; | |
8001 | ||
8002 | /* | |
8003 | * zero the full structure, so that a short copy will be nice. | |
8004 | */ | |
8005 | memset(attr, 0, sizeof(*attr)); | |
8006 | ||
8007 | ret = get_user(size, &uattr->size); | |
8008 | if (ret) | |
8009 | return ret; | |
8010 | ||
8011 | if (size > PAGE_SIZE) /* silly large */ | |
8012 | goto err_size; | |
8013 | ||
8014 | if (!size) /* abi compat */ | |
8015 | size = PERF_ATTR_SIZE_VER0; | |
8016 | ||
8017 | if (size < PERF_ATTR_SIZE_VER0) | |
8018 | goto err_size; | |
8019 | ||
8020 | /* | |
8021 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
8022 | * ensure all the unknown bits are 0 - i.e. new |
8023 | * user-space does not rely on any kernel feature | |
8024 | * extensions we dont know about yet. | |
974802ea PZ |
8025 | */ |
8026 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
8027 | unsigned char __user *addr; |
8028 | unsigned char __user *end; | |
8029 | unsigned char val; | |
974802ea | 8030 | |
cdf8073d IS |
8031 | addr = (void __user *)uattr + sizeof(*attr); |
8032 | end = (void __user *)uattr + size; | |
974802ea | 8033 | |
cdf8073d | 8034 | for (; addr < end; addr++) { |
974802ea PZ |
8035 | ret = get_user(val, addr); |
8036 | if (ret) | |
8037 | return ret; | |
8038 | if (val) | |
8039 | goto err_size; | |
8040 | } | |
b3e62e35 | 8041 | size = sizeof(*attr); |
974802ea PZ |
8042 | } |
8043 | ||
8044 | ret = copy_from_user(attr, uattr, size); | |
8045 | if (ret) | |
8046 | return -EFAULT; | |
8047 | ||
cd757645 | 8048 | if (attr->__reserved_1) |
974802ea PZ |
8049 | return -EINVAL; |
8050 | ||
8051 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8052 | return -EINVAL; | |
8053 | ||
8054 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8055 | return -EINVAL; | |
8056 | ||
bce38cd5 SE |
8057 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8058 | u64 mask = attr->branch_sample_type; | |
8059 | ||
8060 | /* only using defined bits */ | |
8061 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8062 | return -EINVAL; | |
8063 | ||
8064 | /* at least one branch bit must be set */ | |
8065 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8066 | return -EINVAL; | |
8067 | ||
bce38cd5 SE |
8068 | /* propagate priv level, when not set for branch */ |
8069 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8070 | ||
8071 | /* exclude_kernel checked on syscall entry */ | |
8072 | if (!attr->exclude_kernel) | |
8073 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8074 | ||
8075 | if (!attr->exclude_user) | |
8076 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8077 | ||
8078 | if (!attr->exclude_hv) | |
8079 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8080 | /* | |
8081 | * adjust user setting (for HW filter setup) | |
8082 | */ | |
8083 | attr->branch_sample_type = mask; | |
8084 | } | |
e712209a SE |
8085 | /* privileged levels capture (kernel, hv): check permissions */ |
8086 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8087 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8088 | return -EACCES; | |
bce38cd5 | 8089 | } |
4018994f | 8090 | |
c5ebcedb | 8091 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8092 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8093 | if (ret) |
8094 | return ret; | |
8095 | } | |
8096 | ||
8097 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8098 | if (!arch_perf_have_user_stack_dump()) | |
8099 | return -ENOSYS; | |
8100 | ||
8101 | /* | |
8102 | * We have __u32 type for the size, but so far | |
8103 | * we can only use __u16 as maximum due to the | |
8104 | * __u16 sample size limit. | |
8105 | */ | |
8106 | if (attr->sample_stack_user >= USHRT_MAX) | |
8107 | ret = -EINVAL; | |
8108 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8109 | ret = -EINVAL; | |
8110 | } | |
4018994f | 8111 | |
60e2364e SE |
8112 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8113 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8114 | out: |
8115 | return ret; | |
8116 | ||
8117 | err_size: | |
8118 | put_user(sizeof(*attr), &uattr->size); | |
8119 | ret = -E2BIG; | |
8120 | goto out; | |
8121 | } | |
8122 | ||
ac9721f3 PZ |
8123 | static int |
8124 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8125 | { |
b69cf536 | 8126 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8127 | int ret = -EINVAL; |
8128 | ||
ac9721f3 | 8129 | if (!output_event) |
a4be7c27 PZ |
8130 | goto set; |
8131 | ||
ac9721f3 PZ |
8132 | /* don't allow circular references */ |
8133 | if (event == output_event) | |
a4be7c27 PZ |
8134 | goto out; |
8135 | ||
0f139300 PZ |
8136 | /* |
8137 | * Don't allow cross-cpu buffers | |
8138 | */ | |
8139 | if (output_event->cpu != event->cpu) | |
8140 | goto out; | |
8141 | ||
8142 | /* | |
76369139 | 8143 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8144 | */ |
8145 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8146 | goto out; | |
8147 | ||
34f43927 PZ |
8148 | /* |
8149 | * Mixing clocks in the same buffer is trouble you don't need. | |
8150 | */ | |
8151 | if (output_event->clock != event->clock) | |
8152 | goto out; | |
8153 | ||
45bfb2e5 PZ |
8154 | /* |
8155 | * If both events generate aux data, they must be on the same PMU | |
8156 | */ | |
8157 | if (has_aux(event) && has_aux(output_event) && | |
8158 | event->pmu != output_event->pmu) | |
8159 | goto out; | |
8160 | ||
a4be7c27 | 8161 | set: |
cdd6c482 | 8162 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8163 | /* Can't redirect output if we've got an active mmap() */ |
8164 | if (atomic_read(&event->mmap_count)) | |
8165 | goto unlock; | |
a4be7c27 | 8166 | |
ac9721f3 | 8167 | if (output_event) { |
76369139 FW |
8168 | /* get the rb we want to redirect to */ |
8169 | rb = ring_buffer_get(output_event); | |
8170 | if (!rb) | |
ac9721f3 | 8171 | goto unlock; |
a4be7c27 PZ |
8172 | } |
8173 | ||
b69cf536 | 8174 | ring_buffer_attach(event, rb); |
9bb5d40c | 8175 | |
a4be7c27 | 8176 | ret = 0; |
ac9721f3 PZ |
8177 | unlock: |
8178 | mutex_unlock(&event->mmap_mutex); | |
8179 | ||
a4be7c27 | 8180 | out: |
a4be7c27 PZ |
8181 | return ret; |
8182 | } | |
8183 | ||
f63a8daa PZ |
8184 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8185 | { | |
8186 | if (b < a) | |
8187 | swap(a, b); | |
8188 | ||
8189 | mutex_lock(a); | |
8190 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8191 | } | |
8192 | ||
34f43927 PZ |
8193 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8194 | { | |
8195 | bool nmi_safe = false; | |
8196 | ||
8197 | switch (clk_id) { | |
8198 | case CLOCK_MONOTONIC: | |
8199 | event->clock = &ktime_get_mono_fast_ns; | |
8200 | nmi_safe = true; | |
8201 | break; | |
8202 | ||
8203 | case CLOCK_MONOTONIC_RAW: | |
8204 | event->clock = &ktime_get_raw_fast_ns; | |
8205 | nmi_safe = true; | |
8206 | break; | |
8207 | ||
8208 | case CLOCK_REALTIME: | |
8209 | event->clock = &ktime_get_real_ns; | |
8210 | break; | |
8211 | ||
8212 | case CLOCK_BOOTTIME: | |
8213 | event->clock = &ktime_get_boot_ns; | |
8214 | break; | |
8215 | ||
8216 | case CLOCK_TAI: | |
8217 | event->clock = &ktime_get_tai_ns; | |
8218 | break; | |
8219 | ||
8220 | default: | |
8221 | return -EINVAL; | |
8222 | } | |
8223 | ||
8224 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8225 | return -EINVAL; | |
8226 | ||
8227 | return 0; | |
8228 | } | |
8229 | ||
0793a61d | 8230 | /** |
cdd6c482 | 8231 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8232 | * |
cdd6c482 | 8233 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8234 | * @pid: target pid |
9f66a381 | 8235 | * @cpu: target cpu |
cdd6c482 | 8236 | * @group_fd: group leader event fd |
0793a61d | 8237 | */ |
cdd6c482 IM |
8238 | SYSCALL_DEFINE5(perf_event_open, |
8239 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8240 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8241 | { |
b04243ef PZ |
8242 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8243 | struct perf_event *event, *sibling; | |
cdd6c482 | 8244 | struct perf_event_attr attr; |
f63a8daa | 8245 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8246 | struct file *event_file = NULL; |
2903ff01 | 8247 | struct fd group = {NULL, 0}; |
38a81da2 | 8248 | struct task_struct *task = NULL; |
89a1e187 | 8249 | struct pmu *pmu; |
ea635c64 | 8250 | int event_fd; |
b04243ef | 8251 | int move_group = 0; |
dc86cabe | 8252 | int err; |
a21b0b35 | 8253 | int f_flags = O_RDWR; |
79dff51e | 8254 | int cgroup_fd = -1; |
0793a61d | 8255 | |
2743a5b0 | 8256 | /* for future expandability... */ |
e5d1367f | 8257 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8258 | return -EINVAL; |
8259 | ||
dc86cabe IM |
8260 | err = perf_copy_attr(attr_uptr, &attr); |
8261 | if (err) | |
8262 | return err; | |
eab656ae | 8263 | |
0764771d PZ |
8264 | if (!attr.exclude_kernel) { |
8265 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8266 | return -EACCES; | |
8267 | } | |
8268 | ||
df58ab24 | 8269 | if (attr.freq) { |
cdd6c482 | 8270 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8271 | return -EINVAL; |
0819b2e3 PZ |
8272 | } else { |
8273 | if (attr.sample_period & (1ULL << 63)) | |
8274 | return -EINVAL; | |
df58ab24 PZ |
8275 | } |
8276 | ||
e5d1367f SE |
8277 | /* |
8278 | * In cgroup mode, the pid argument is used to pass the fd | |
8279 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8280 | * designates the cpu on which to monitor threads from that | |
8281 | * cgroup. | |
8282 | */ | |
8283 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8284 | return -EINVAL; | |
8285 | ||
a21b0b35 YD |
8286 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8287 | f_flags |= O_CLOEXEC; | |
8288 | ||
8289 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8290 | if (event_fd < 0) |
8291 | return event_fd; | |
8292 | ||
ac9721f3 | 8293 | if (group_fd != -1) { |
2903ff01 AV |
8294 | err = perf_fget_light(group_fd, &group); |
8295 | if (err) | |
d14b12d7 | 8296 | goto err_fd; |
2903ff01 | 8297 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8298 | if (flags & PERF_FLAG_FD_OUTPUT) |
8299 | output_event = group_leader; | |
8300 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8301 | group_leader = NULL; | |
8302 | } | |
8303 | ||
e5d1367f | 8304 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8305 | task = find_lively_task_by_vpid(pid); |
8306 | if (IS_ERR(task)) { | |
8307 | err = PTR_ERR(task); | |
8308 | goto err_group_fd; | |
8309 | } | |
8310 | } | |
8311 | ||
1f4ee503 PZ |
8312 | if (task && group_leader && |
8313 | group_leader->attr.inherit != attr.inherit) { | |
8314 | err = -EINVAL; | |
8315 | goto err_task; | |
8316 | } | |
8317 | ||
fbfc623f YZ |
8318 | get_online_cpus(); |
8319 | ||
79dff51e MF |
8320 | if (flags & PERF_FLAG_PID_CGROUP) |
8321 | cgroup_fd = pid; | |
8322 | ||
4dc0da86 | 8323 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8324 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8325 | if (IS_ERR(event)) { |
8326 | err = PTR_ERR(event); | |
1f4ee503 | 8327 | goto err_cpus; |
d14b12d7 SE |
8328 | } |
8329 | ||
53b25335 VW |
8330 | if (is_sampling_event(event)) { |
8331 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8332 | err = -ENOTSUPP; | |
8333 | goto err_alloc; | |
8334 | } | |
8335 | } | |
8336 | ||
766d6c07 FW |
8337 | account_event(event); |
8338 | ||
89a1e187 PZ |
8339 | /* |
8340 | * Special case software events and allow them to be part of | |
8341 | * any hardware group. | |
8342 | */ | |
8343 | pmu = event->pmu; | |
b04243ef | 8344 | |
34f43927 PZ |
8345 | if (attr.use_clockid) { |
8346 | err = perf_event_set_clock(event, attr.clockid); | |
8347 | if (err) | |
8348 | goto err_alloc; | |
8349 | } | |
8350 | ||
b04243ef PZ |
8351 | if (group_leader && |
8352 | (is_software_event(event) != is_software_event(group_leader))) { | |
8353 | if (is_software_event(event)) { | |
8354 | /* | |
8355 | * If event and group_leader are not both a software | |
8356 | * event, and event is, then group leader is not. | |
8357 | * | |
8358 | * Allow the addition of software events to !software | |
8359 | * groups, this is safe because software events never | |
8360 | * fail to schedule. | |
8361 | */ | |
8362 | pmu = group_leader->pmu; | |
8363 | } else if (is_software_event(group_leader) && | |
8364 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8365 | /* | |
8366 | * In case the group is a pure software group, and we | |
8367 | * try to add a hardware event, move the whole group to | |
8368 | * the hardware context. | |
8369 | */ | |
8370 | move_group = 1; | |
8371 | } | |
8372 | } | |
89a1e187 PZ |
8373 | |
8374 | /* | |
8375 | * Get the target context (task or percpu): | |
8376 | */ | |
4af57ef2 | 8377 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8378 | if (IS_ERR(ctx)) { |
8379 | err = PTR_ERR(ctx); | |
c6be5a5c | 8380 | goto err_alloc; |
89a1e187 PZ |
8381 | } |
8382 | ||
bed5b25a AS |
8383 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8384 | err = -EBUSY; | |
8385 | goto err_context; | |
8386 | } | |
8387 | ||
fd1edb3a PZ |
8388 | if (task) { |
8389 | put_task_struct(task); | |
8390 | task = NULL; | |
8391 | } | |
8392 | ||
ccff286d | 8393 | /* |
cdd6c482 | 8394 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8395 | */ |
ac9721f3 | 8396 | if (group_leader) { |
dc86cabe | 8397 | err = -EINVAL; |
04289bb9 | 8398 | |
04289bb9 | 8399 | /* |
ccff286d IM |
8400 | * Do not allow a recursive hierarchy (this new sibling |
8401 | * becoming part of another group-sibling): | |
8402 | */ | |
8403 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8404 | goto err_context; |
34f43927 PZ |
8405 | |
8406 | /* All events in a group should have the same clock */ | |
8407 | if (group_leader->clock != event->clock) | |
8408 | goto err_context; | |
8409 | ||
ccff286d IM |
8410 | /* |
8411 | * Do not allow to attach to a group in a different | |
8412 | * task or CPU context: | |
04289bb9 | 8413 | */ |
b04243ef | 8414 | if (move_group) { |
c3c87e77 PZ |
8415 | /* |
8416 | * Make sure we're both on the same task, or both | |
8417 | * per-cpu events. | |
8418 | */ | |
8419 | if (group_leader->ctx->task != ctx->task) | |
8420 | goto err_context; | |
8421 | ||
8422 | /* | |
8423 | * Make sure we're both events for the same CPU; | |
8424 | * grouping events for different CPUs is broken; since | |
8425 | * you can never concurrently schedule them anyhow. | |
8426 | */ | |
8427 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8428 | goto err_context; |
8429 | } else { | |
8430 | if (group_leader->ctx != ctx) | |
8431 | goto err_context; | |
8432 | } | |
8433 | ||
3b6f9e5c PM |
8434 | /* |
8435 | * Only a group leader can be exclusive or pinned | |
8436 | */ | |
0d48696f | 8437 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8438 | goto err_context; |
ac9721f3 PZ |
8439 | } |
8440 | ||
8441 | if (output_event) { | |
8442 | err = perf_event_set_output(event, output_event); | |
8443 | if (err) | |
c3f00c70 | 8444 | goto err_context; |
ac9721f3 | 8445 | } |
0793a61d | 8446 | |
a21b0b35 YD |
8447 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8448 | f_flags); | |
ea635c64 AV |
8449 | if (IS_ERR(event_file)) { |
8450 | err = PTR_ERR(event_file); | |
c3f00c70 | 8451 | goto err_context; |
ea635c64 | 8452 | } |
9b51f66d | 8453 | |
b04243ef | 8454 | if (move_group) { |
f63a8daa | 8455 | gctx = group_leader->ctx; |
f55fc2a5 | 8456 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
84c4e620 PZ |
8457 | if (gctx->task == TASK_TOMBSTONE) { |
8458 | err = -ESRCH; | |
8459 | goto err_locked; | |
8460 | } | |
f55fc2a5 PZ |
8461 | } else { |
8462 | mutex_lock(&ctx->mutex); | |
8463 | } | |
8464 | ||
84c4e620 PZ |
8465 | if (ctx->task == TASK_TOMBSTONE) { |
8466 | err = -ESRCH; | |
8467 | goto err_locked; | |
8468 | } | |
8469 | ||
a723968c PZ |
8470 | if (!perf_event_validate_size(event)) { |
8471 | err = -E2BIG; | |
8472 | goto err_locked; | |
8473 | } | |
8474 | ||
f55fc2a5 PZ |
8475 | /* |
8476 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8477 | * because we need to serialize with concurrent event creation. | |
8478 | */ | |
8479 | if (!exclusive_event_installable(event, ctx)) { | |
8480 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8481 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8482 | |
f55fc2a5 PZ |
8483 | err = -EBUSY; |
8484 | goto err_locked; | |
8485 | } | |
f63a8daa | 8486 | |
f55fc2a5 PZ |
8487 | WARN_ON_ONCE(ctx->parent_ctx); |
8488 | ||
8489 | if (move_group) { | |
f63a8daa PZ |
8490 | /* |
8491 | * See perf_event_ctx_lock() for comments on the details | |
8492 | * of swizzling perf_event::ctx. | |
8493 | */ | |
45a0e07a | 8494 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8495 | |
b04243ef PZ |
8496 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8497 | group_entry) { | |
45a0e07a | 8498 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8499 | put_ctx(gctx); |
8500 | } | |
b04243ef | 8501 | |
f63a8daa PZ |
8502 | /* |
8503 | * Wait for everybody to stop referencing the events through | |
8504 | * the old lists, before installing it on new lists. | |
8505 | */ | |
0cda4c02 | 8506 | synchronize_rcu(); |
f63a8daa | 8507 | |
8f95b435 PZI |
8508 | /* |
8509 | * Install the group siblings before the group leader. | |
8510 | * | |
8511 | * Because a group leader will try and install the entire group | |
8512 | * (through the sibling list, which is still in-tact), we can | |
8513 | * end up with siblings installed in the wrong context. | |
8514 | * | |
8515 | * By installing siblings first we NO-OP because they're not | |
8516 | * reachable through the group lists. | |
8517 | */ | |
b04243ef PZ |
8518 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8519 | group_entry) { | |
8f95b435 | 8520 | perf_event__state_init(sibling); |
9fc81d87 | 8521 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8522 | get_ctx(ctx); |
8523 | } | |
8f95b435 PZI |
8524 | |
8525 | /* | |
8526 | * Removing from the context ends up with disabled | |
8527 | * event. What we want here is event in the initial | |
8528 | * startup state, ready to be add into new context. | |
8529 | */ | |
8530 | perf_event__state_init(group_leader); | |
8531 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8532 | get_ctx(ctx); | |
b04243ef | 8533 | |
f55fc2a5 PZ |
8534 | /* |
8535 | * Now that all events are installed in @ctx, nothing | |
8536 | * references @gctx anymore, so drop the last reference we have | |
8537 | * on it. | |
8538 | */ | |
8539 | put_ctx(gctx); | |
bed5b25a AS |
8540 | } |
8541 | ||
f73e22ab PZ |
8542 | /* |
8543 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8544 | * that we're serialized against further additions and before | |
8545 | * perf_install_in_context() which is the point the event is active and | |
8546 | * can use these values. | |
8547 | */ | |
8548 | perf_event__header_size(event); | |
8549 | perf_event__id_header_size(event); | |
8550 | ||
78cd2c74 PZ |
8551 | event->owner = current; |
8552 | ||
e2d37cd2 | 8553 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8554 | perf_unpin_context(ctx); |
f63a8daa | 8555 | |
f55fc2a5 | 8556 | if (move_group) |
f63a8daa | 8557 | mutex_unlock(&gctx->mutex); |
d859e29f | 8558 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8559 | |
fbfc623f YZ |
8560 | put_online_cpus(); |
8561 | ||
cdd6c482 IM |
8562 | mutex_lock(¤t->perf_event_mutex); |
8563 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8564 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8565 | |
8a49542c PZ |
8566 | /* |
8567 | * Drop the reference on the group_event after placing the | |
8568 | * new event on the sibling_list. This ensures destruction | |
8569 | * of the group leader will find the pointer to itself in | |
8570 | * perf_group_detach(). | |
8571 | */ | |
2903ff01 | 8572 | fdput(group); |
ea635c64 AV |
8573 | fd_install(event_fd, event_file); |
8574 | return event_fd; | |
0793a61d | 8575 | |
f55fc2a5 PZ |
8576 | err_locked: |
8577 | if (move_group) | |
8578 | mutex_unlock(&gctx->mutex); | |
8579 | mutex_unlock(&ctx->mutex); | |
8580 | /* err_file: */ | |
8581 | fput(event_file); | |
c3f00c70 | 8582 | err_context: |
fe4b04fa | 8583 | perf_unpin_context(ctx); |
ea635c64 | 8584 | put_ctx(ctx); |
c6be5a5c | 8585 | err_alloc: |
13005627 PZ |
8586 | /* |
8587 | * If event_file is set, the fput() above will have called ->release() | |
8588 | * and that will take care of freeing the event. | |
8589 | */ | |
8590 | if (!event_file) | |
8591 | free_event(event); | |
1f4ee503 | 8592 | err_cpus: |
fbfc623f | 8593 | put_online_cpus(); |
1f4ee503 | 8594 | err_task: |
e7d0bc04 PZ |
8595 | if (task) |
8596 | put_task_struct(task); | |
89a1e187 | 8597 | err_group_fd: |
2903ff01 | 8598 | fdput(group); |
ea635c64 AV |
8599 | err_fd: |
8600 | put_unused_fd(event_fd); | |
dc86cabe | 8601 | return err; |
0793a61d TG |
8602 | } |
8603 | ||
fb0459d7 AV |
8604 | /** |
8605 | * perf_event_create_kernel_counter | |
8606 | * | |
8607 | * @attr: attributes of the counter to create | |
8608 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8609 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8610 | */ |
8611 | struct perf_event * | |
8612 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8613 | struct task_struct *task, |
4dc0da86 AK |
8614 | perf_overflow_handler_t overflow_handler, |
8615 | void *context) | |
fb0459d7 | 8616 | { |
fb0459d7 | 8617 | struct perf_event_context *ctx; |
c3f00c70 | 8618 | struct perf_event *event; |
fb0459d7 | 8619 | int err; |
d859e29f | 8620 | |
fb0459d7 AV |
8621 | /* |
8622 | * Get the target context (task or percpu): | |
8623 | */ | |
d859e29f | 8624 | |
4dc0da86 | 8625 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8626 | overflow_handler, context, -1); |
c3f00c70 PZ |
8627 | if (IS_ERR(event)) { |
8628 | err = PTR_ERR(event); | |
8629 | goto err; | |
8630 | } | |
d859e29f | 8631 | |
f8697762 | 8632 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8633 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8634 | |
766d6c07 FW |
8635 | account_event(event); |
8636 | ||
4af57ef2 | 8637 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8638 | if (IS_ERR(ctx)) { |
8639 | err = PTR_ERR(ctx); | |
c3f00c70 | 8640 | goto err_free; |
d859e29f | 8641 | } |
fb0459d7 | 8642 | |
fb0459d7 AV |
8643 | WARN_ON_ONCE(ctx->parent_ctx); |
8644 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
8645 | if (ctx->task == TASK_TOMBSTONE) { |
8646 | err = -ESRCH; | |
8647 | goto err_unlock; | |
8648 | } | |
8649 | ||
bed5b25a | 8650 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 8651 | err = -EBUSY; |
84c4e620 | 8652 | goto err_unlock; |
bed5b25a AS |
8653 | } |
8654 | ||
fb0459d7 | 8655 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8656 | perf_unpin_context(ctx); |
fb0459d7 AV |
8657 | mutex_unlock(&ctx->mutex); |
8658 | ||
fb0459d7 AV |
8659 | return event; |
8660 | ||
84c4e620 PZ |
8661 | err_unlock: |
8662 | mutex_unlock(&ctx->mutex); | |
8663 | perf_unpin_context(ctx); | |
8664 | put_ctx(ctx); | |
c3f00c70 PZ |
8665 | err_free: |
8666 | free_event(event); | |
8667 | err: | |
c6567f64 | 8668 | return ERR_PTR(err); |
9b51f66d | 8669 | } |
fb0459d7 | 8670 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8671 | |
0cda4c02 YZ |
8672 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8673 | { | |
8674 | struct perf_event_context *src_ctx; | |
8675 | struct perf_event_context *dst_ctx; | |
8676 | struct perf_event *event, *tmp; | |
8677 | LIST_HEAD(events); | |
8678 | ||
8679 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8680 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8681 | ||
f63a8daa PZ |
8682 | /* |
8683 | * See perf_event_ctx_lock() for comments on the details | |
8684 | * of swizzling perf_event::ctx. | |
8685 | */ | |
8686 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8687 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8688 | event_entry) { | |
45a0e07a | 8689 | perf_remove_from_context(event, 0); |
9a545de0 | 8690 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8691 | put_ctx(src_ctx); |
9886167d | 8692 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8693 | } |
0cda4c02 | 8694 | |
8f95b435 PZI |
8695 | /* |
8696 | * Wait for the events to quiesce before re-instating them. | |
8697 | */ | |
0cda4c02 YZ |
8698 | synchronize_rcu(); |
8699 | ||
8f95b435 PZI |
8700 | /* |
8701 | * Re-instate events in 2 passes. | |
8702 | * | |
8703 | * Skip over group leaders and only install siblings on this first | |
8704 | * pass, siblings will not get enabled without a leader, however a | |
8705 | * leader will enable its siblings, even if those are still on the old | |
8706 | * context. | |
8707 | */ | |
8708 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8709 | if (event->group_leader == event) | |
8710 | continue; | |
8711 | ||
8712 | list_del(&event->migrate_entry); | |
8713 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8714 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8715 | account_event_cpu(event, dst_cpu); | |
8716 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8717 | get_ctx(dst_ctx); | |
8718 | } | |
8719 | ||
8720 | /* | |
8721 | * Once all the siblings are setup properly, install the group leaders | |
8722 | * to make it go. | |
8723 | */ | |
9886167d PZ |
8724 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8725 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8726 | if (event->state >= PERF_EVENT_STATE_OFF) |
8727 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8728 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8729 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8730 | get_ctx(dst_ctx); | |
8731 | } | |
8732 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8733 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8734 | } |
8735 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8736 | ||
cdd6c482 | 8737 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8738 | struct task_struct *child) |
d859e29f | 8739 | { |
cdd6c482 | 8740 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8741 | u64 child_val; |
d859e29f | 8742 | |
cdd6c482 IM |
8743 | if (child_event->attr.inherit_stat) |
8744 | perf_event_read_event(child_event, child); | |
38b200d6 | 8745 | |
b5e58793 | 8746 | child_val = perf_event_count(child_event); |
d859e29f PM |
8747 | |
8748 | /* | |
8749 | * Add back the child's count to the parent's count: | |
8750 | */ | |
a6e6dea6 | 8751 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8752 | atomic64_add(child_event->total_time_enabled, |
8753 | &parent_event->child_total_time_enabled); | |
8754 | atomic64_add(child_event->total_time_running, | |
8755 | &parent_event->child_total_time_running); | |
d859e29f PM |
8756 | } |
8757 | ||
9b51f66d | 8758 | static void |
8ba289b8 PZ |
8759 | perf_event_exit_event(struct perf_event *child_event, |
8760 | struct perf_event_context *child_ctx, | |
8761 | struct task_struct *child) | |
9b51f66d | 8762 | { |
8ba289b8 PZ |
8763 | struct perf_event *parent_event = child_event->parent; |
8764 | ||
1903d50c PZ |
8765 | /* |
8766 | * Do not destroy the 'original' grouping; because of the context | |
8767 | * switch optimization the original events could've ended up in a | |
8768 | * random child task. | |
8769 | * | |
8770 | * If we were to destroy the original group, all group related | |
8771 | * operations would cease to function properly after this random | |
8772 | * child dies. | |
8773 | * | |
8774 | * Do destroy all inherited groups, we don't care about those | |
8775 | * and being thorough is better. | |
8776 | */ | |
32132a3d PZ |
8777 | raw_spin_lock_irq(&child_ctx->lock); |
8778 | WARN_ON_ONCE(child_ctx->is_active); | |
8779 | ||
8ba289b8 | 8780 | if (parent_event) |
32132a3d PZ |
8781 | perf_group_detach(child_event); |
8782 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 8783 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 8784 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 8785 | |
9b51f66d | 8786 | /* |
8ba289b8 | 8787 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 8788 | */ |
8ba289b8 | 8789 | if (!parent_event) { |
179033b3 | 8790 | perf_event_wakeup(child_event); |
8ba289b8 | 8791 | return; |
4bcf349a | 8792 | } |
8ba289b8 PZ |
8793 | /* |
8794 | * Child events can be cleaned up. | |
8795 | */ | |
8796 | ||
8797 | sync_child_event(child_event, child); | |
8798 | ||
8799 | /* | |
8800 | * Remove this event from the parent's list | |
8801 | */ | |
8802 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8803 | mutex_lock(&parent_event->child_mutex); | |
8804 | list_del_init(&child_event->child_list); | |
8805 | mutex_unlock(&parent_event->child_mutex); | |
8806 | ||
8807 | /* | |
8808 | * Kick perf_poll() for is_event_hup(). | |
8809 | */ | |
8810 | perf_event_wakeup(parent_event); | |
8811 | free_event(child_event); | |
8812 | put_event(parent_event); | |
9b51f66d IM |
8813 | } |
8814 | ||
8dc85d54 | 8815 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8816 | { |
211de6eb | 8817 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 8818 | struct perf_event *child_event, *next; |
63b6da39 PZ |
8819 | |
8820 | WARN_ON_ONCE(child != current); | |
9b51f66d | 8821 | |
6a3351b6 | 8822 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 8823 | if (!child_ctx) |
9b51f66d IM |
8824 | return; |
8825 | ||
ad3a37de | 8826 | /* |
6a3351b6 PZ |
8827 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
8828 | * ctx::mutex over the entire thing. This serializes against almost | |
8829 | * everything that wants to access the ctx. | |
8830 | * | |
8831 | * The exception is sys_perf_event_open() / | |
8832 | * perf_event_create_kernel_count() which does find_get_context() | |
8833 | * without ctx::mutex (it cannot because of the move_group double mutex | |
8834 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 8835 | */ |
6a3351b6 | 8836 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
8837 | |
8838 | /* | |
6a3351b6 PZ |
8839 | * In a single ctx::lock section, de-schedule the events and detach the |
8840 | * context from the task such that we cannot ever get it scheduled back | |
8841 | * in. | |
c93f7669 | 8842 | */ |
6a3351b6 | 8843 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 8844 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 8845 | |
71a851b4 | 8846 | /* |
63b6da39 PZ |
8847 | * Now that the context is inactive, destroy the task <-> ctx relation |
8848 | * and mark the context dead. | |
71a851b4 | 8849 | */ |
63b6da39 PZ |
8850 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
8851 | put_ctx(child_ctx); /* cannot be last */ | |
8852 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
8853 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 8854 | |
211de6eb | 8855 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 8856 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8857 | |
211de6eb PZ |
8858 | if (clone_ctx) |
8859 | put_ctx(clone_ctx); | |
4a1c0f26 | 8860 | |
9f498cc5 | 8861 | /* |
cdd6c482 IM |
8862 | * Report the task dead after unscheduling the events so that we |
8863 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8864 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8865 | */ |
cdd6c482 | 8866 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8867 | |
ebf905fc | 8868 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 8869 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 8870 | |
a63eaf34 PM |
8871 | mutex_unlock(&child_ctx->mutex); |
8872 | ||
8873 | put_ctx(child_ctx); | |
9b51f66d IM |
8874 | } |
8875 | ||
8dc85d54 PZ |
8876 | /* |
8877 | * When a child task exits, feed back event values to parent events. | |
8878 | */ | |
8879 | void perf_event_exit_task(struct task_struct *child) | |
8880 | { | |
8882135b | 8881 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8882 | int ctxn; |
8883 | ||
8882135b PZ |
8884 | mutex_lock(&child->perf_event_mutex); |
8885 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8886 | owner_entry) { | |
8887 | list_del_init(&event->owner_entry); | |
8888 | ||
8889 | /* | |
8890 | * Ensure the list deletion is visible before we clear | |
8891 | * the owner, closes a race against perf_release() where | |
8892 | * we need to serialize on the owner->perf_event_mutex. | |
8893 | */ | |
f47c02c0 | 8894 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
8895 | } |
8896 | mutex_unlock(&child->perf_event_mutex); | |
8897 | ||
8dc85d54 PZ |
8898 | for_each_task_context_nr(ctxn) |
8899 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8900 | |
8901 | /* | |
8902 | * The perf_event_exit_task_context calls perf_event_task | |
8903 | * with child's task_ctx, which generates EXIT events for | |
8904 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8905 | * At this point we need to send EXIT events to cpu contexts. | |
8906 | */ | |
8907 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8908 | } |
8909 | ||
889ff015 FW |
8910 | static void perf_free_event(struct perf_event *event, |
8911 | struct perf_event_context *ctx) | |
8912 | { | |
8913 | struct perf_event *parent = event->parent; | |
8914 | ||
8915 | if (WARN_ON_ONCE(!parent)) | |
8916 | return; | |
8917 | ||
8918 | mutex_lock(&parent->child_mutex); | |
8919 | list_del_init(&event->child_list); | |
8920 | mutex_unlock(&parent->child_mutex); | |
8921 | ||
a6fa941d | 8922 | put_event(parent); |
889ff015 | 8923 | |
652884fe | 8924 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8925 | perf_group_detach(event); |
889ff015 | 8926 | list_del_event(event, ctx); |
652884fe | 8927 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8928 | free_event(event); |
8929 | } | |
8930 | ||
bbbee908 | 8931 | /* |
652884fe | 8932 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8933 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8934 | * |
8935 | * Not all locks are strictly required, but take them anyway to be nice and | |
8936 | * help out with the lockdep assertions. | |
bbbee908 | 8937 | */ |
cdd6c482 | 8938 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8939 | { |
8dc85d54 | 8940 | struct perf_event_context *ctx; |
cdd6c482 | 8941 | struct perf_event *event, *tmp; |
8dc85d54 | 8942 | int ctxn; |
bbbee908 | 8943 | |
8dc85d54 PZ |
8944 | for_each_task_context_nr(ctxn) { |
8945 | ctx = task->perf_event_ctxp[ctxn]; | |
8946 | if (!ctx) | |
8947 | continue; | |
bbbee908 | 8948 | |
8dc85d54 | 8949 | mutex_lock(&ctx->mutex); |
bbbee908 | 8950 | again: |
8dc85d54 PZ |
8951 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8952 | group_entry) | |
8953 | perf_free_event(event, ctx); | |
bbbee908 | 8954 | |
8dc85d54 PZ |
8955 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8956 | group_entry) | |
8957 | perf_free_event(event, ctx); | |
bbbee908 | 8958 | |
8dc85d54 PZ |
8959 | if (!list_empty(&ctx->pinned_groups) || |
8960 | !list_empty(&ctx->flexible_groups)) | |
8961 | goto again; | |
bbbee908 | 8962 | |
8dc85d54 | 8963 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8964 | |
8dc85d54 PZ |
8965 | put_ctx(ctx); |
8966 | } | |
889ff015 FW |
8967 | } |
8968 | ||
4e231c79 PZ |
8969 | void perf_event_delayed_put(struct task_struct *task) |
8970 | { | |
8971 | int ctxn; | |
8972 | ||
8973 | for_each_task_context_nr(ctxn) | |
8974 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8975 | } | |
8976 | ||
e03e7ee3 | 8977 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 8978 | { |
e03e7ee3 | 8979 | struct file *file; |
ffe8690c | 8980 | |
e03e7ee3 AS |
8981 | file = fget_raw(fd); |
8982 | if (!file) | |
8983 | return ERR_PTR(-EBADF); | |
ffe8690c | 8984 | |
e03e7ee3 AS |
8985 | if (file->f_op != &perf_fops) { |
8986 | fput(file); | |
8987 | return ERR_PTR(-EBADF); | |
8988 | } | |
ffe8690c | 8989 | |
e03e7ee3 | 8990 | return file; |
ffe8690c KX |
8991 | } |
8992 | ||
8993 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8994 | { | |
8995 | if (!event) | |
8996 | return ERR_PTR(-EINVAL); | |
8997 | ||
8998 | return &event->attr; | |
8999 | } | |
9000 | ||
97dee4f3 PZ |
9001 | /* |
9002 | * inherit a event from parent task to child task: | |
9003 | */ | |
9004 | static struct perf_event * | |
9005 | inherit_event(struct perf_event *parent_event, | |
9006 | struct task_struct *parent, | |
9007 | struct perf_event_context *parent_ctx, | |
9008 | struct task_struct *child, | |
9009 | struct perf_event *group_leader, | |
9010 | struct perf_event_context *child_ctx) | |
9011 | { | |
1929def9 | 9012 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 9013 | struct perf_event *child_event; |
cee010ec | 9014 | unsigned long flags; |
97dee4f3 PZ |
9015 | |
9016 | /* | |
9017 | * Instead of creating recursive hierarchies of events, | |
9018 | * we link inherited events back to the original parent, | |
9019 | * which has a filp for sure, which we use as the reference | |
9020 | * count: | |
9021 | */ | |
9022 | if (parent_event->parent) | |
9023 | parent_event = parent_event->parent; | |
9024 | ||
9025 | child_event = perf_event_alloc(&parent_event->attr, | |
9026 | parent_event->cpu, | |
d580ff86 | 9027 | child, |
97dee4f3 | 9028 | group_leader, parent_event, |
79dff51e | 9029 | NULL, NULL, -1); |
97dee4f3 PZ |
9030 | if (IS_ERR(child_event)) |
9031 | return child_event; | |
a6fa941d | 9032 | |
c6e5b732 PZ |
9033 | /* |
9034 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
9035 | * must be under the same lock in order to serialize against | |
9036 | * perf_event_release_kernel(), such that either we must observe | |
9037 | * is_orphaned_event() or they will observe us on the child_list. | |
9038 | */ | |
9039 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
9040 | if (is_orphaned_event(parent_event) || |
9041 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 9042 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
9043 | free_event(child_event); |
9044 | return NULL; | |
9045 | } | |
9046 | ||
97dee4f3 PZ |
9047 | get_ctx(child_ctx); |
9048 | ||
9049 | /* | |
9050 | * Make the child state follow the state of the parent event, | |
9051 | * not its attr.disabled bit. We hold the parent's mutex, | |
9052 | * so we won't race with perf_event_{en, dis}able_family. | |
9053 | */ | |
1929def9 | 9054 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
9055 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
9056 | else | |
9057 | child_event->state = PERF_EVENT_STATE_OFF; | |
9058 | ||
9059 | if (parent_event->attr.freq) { | |
9060 | u64 sample_period = parent_event->hw.sample_period; | |
9061 | struct hw_perf_event *hwc = &child_event->hw; | |
9062 | ||
9063 | hwc->sample_period = sample_period; | |
9064 | hwc->last_period = sample_period; | |
9065 | ||
9066 | local64_set(&hwc->period_left, sample_period); | |
9067 | } | |
9068 | ||
9069 | child_event->ctx = child_ctx; | |
9070 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9071 | child_event->overflow_handler_context |
9072 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9073 | |
614b6780 TG |
9074 | /* |
9075 | * Precalculate sample_data sizes | |
9076 | */ | |
9077 | perf_event__header_size(child_event); | |
6844c09d | 9078 | perf_event__id_header_size(child_event); |
614b6780 | 9079 | |
97dee4f3 PZ |
9080 | /* |
9081 | * Link it up in the child's context: | |
9082 | */ | |
cee010ec | 9083 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9084 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9085 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9086 | |
97dee4f3 PZ |
9087 | /* |
9088 | * Link this into the parent event's child list | |
9089 | */ | |
97dee4f3 PZ |
9090 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9091 | mutex_unlock(&parent_event->child_mutex); | |
9092 | ||
9093 | return child_event; | |
9094 | } | |
9095 | ||
9096 | static int inherit_group(struct perf_event *parent_event, | |
9097 | struct task_struct *parent, | |
9098 | struct perf_event_context *parent_ctx, | |
9099 | struct task_struct *child, | |
9100 | struct perf_event_context *child_ctx) | |
9101 | { | |
9102 | struct perf_event *leader; | |
9103 | struct perf_event *sub; | |
9104 | struct perf_event *child_ctr; | |
9105 | ||
9106 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9107 | child, NULL, child_ctx); | |
9108 | if (IS_ERR(leader)) | |
9109 | return PTR_ERR(leader); | |
9110 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9111 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9112 | child, leader, child_ctx); | |
9113 | if (IS_ERR(child_ctr)) | |
9114 | return PTR_ERR(child_ctr); | |
9115 | } | |
9116 | return 0; | |
889ff015 FW |
9117 | } |
9118 | ||
9119 | static int | |
9120 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9121 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9122 | struct task_struct *child, int ctxn, |
889ff015 FW |
9123 | int *inherited_all) |
9124 | { | |
9125 | int ret; | |
8dc85d54 | 9126 | struct perf_event_context *child_ctx; |
889ff015 FW |
9127 | |
9128 | if (!event->attr.inherit) { | |
9129 | *inherited_all = 0; | |
9130 | return 0; | |
bbbee908 PZ |
9131 | } |
9132 | ||
fe4b04fa | 9133 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9134 | if (!child_ctx) { |
9135 | /* | |
9136 | * This is executed from the parent task context, so | |
9137 | * inherit events that have been marked for cloning. | |
9138 | * First allocate and initialize a context for the | |
9139 | * child. | |
9140 | */ | |
bbbee908 | 9141 | |
734df5ab | 9142 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9143 | if (!child_ctx) |
9144 | return -ENOMEM; | |
bbbee908 | 9145 | |
8dc85d54 | 9146 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9147 | } |
9148 | ||
9149 | ret = inherit_group(event, parent, parent_ctx, | |
9150 | child, child_ctx); | |
9151 | ||
9152 | if (ret) | |
9153 | *inherited_all = 0; | |
9154 | ||
9155 | return ret; | |
bbbee908 PZ |
9156 | } |
9157 | ||
9b51f66d | 9158 | /* |
cdd6c482 | 9159 | * Initialize the perf_event context in task_struct |
9b51f66d | 9160 | */ |
985c8dcb | 9161 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9162 | { |
889ff015 | 9163 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9164 | struct perf_event_context *cloned_ctx; |
9165 | struct perf_event *event; | |
9b51f66d | 9166 | struct task_struct *parent = current; |
564c2b21 | 9167 | int inherited_all = 1; |
dddd3379 | 9168 | unsigned long flags; |
6ab423e0 | 9169 | int ret = 0; |
9b51f66d | 9170 | |
8dc85d54 | 9171 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9172 | return 0; |
9173 | ||
ad3a37de | 9174 | /* |
25346b93 PM |
9175 | * If the parent's context is a clone, pin it so it won't get |
9176 | * swapped under us. | |
ad3a37de | 9177 | */ |
8dc85d54 | 9178 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9179 | if (!parent_ctx) |
9180 | return 0; | |
25346b93 | 9181 | |
ad3a37de PM |
9182 | /* |
9183 | * No need to check if parent_ctx != NULL here; since we saw | |
9184 | * it non-NULL earlier, the only reason for it to become NULL | |
9185 | * is if we exit, and since we're currently in the middle of | |
9186 | * a fork we can't be exiting at the same time. | |
9187 | */ | |
ad3a37de | 9188 | |
9b51f66d IM |
9189 | /* |
9190 | * Lock the parent list. No need to lock the child - not PID | |
9191 | * hashed yet and not running, so nobody can access it. | |
9192 | */ | |
d859e29f | 9193 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9194 | |
9195 | /* | |
9196 | * We dont have to disable NMIs - we are only looking at | |
9197 | * the list, not manipulating it: | |
9198 | */ | |
889ff015 | 9199 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9200 | ret = inherit_task_group(event, parent, parent_ctx, |
9201 | child, ctxn, &inherited_all); | |
889ff015 FW |
9202 | if (ret) |
9203 | break; | |
9204 | } | |
b93f7978 | 9205 | |
dddd3379 TG |
9206 | /* |
9207 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9208 | * to allocations, but we need to prevent rotation because | |
9209 | * rotate_ctx() will change the list from interrupt context. | |
9210 | */ | |
9211 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9212 | parent_ctx->rotate_disable = 1; | |
9213 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9214 | ||
889ff015 | 9215 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9216 | ret = inherit_task_group(event, parent, parent_ctx, |
9217 | child, ctxn, &inherited_all); | |
889ff015 | 9218 | if (ret) |
9b51f66d | 9219 | break; |
564c2b21 PM |
9220 | } |
9221 | ||
dddd3379 TG |
9222 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9223 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9224 | |
8dc85d54 | 9225 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9226 | |
05cbaa28 | 9227 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9228 | /* |
9229 | * Mark the child context as a clone of the parent | |
9230 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9231 | * |
9232 | * Note that if the parent is a clone, the holding of | |
9233 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9234 | */ |
c5ed5145 | 9235 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9236 | if (cloned_ctx) { |
9237 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9238 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9239 | } else { |
9240 | child_ctx->parent_ctx = parent_ctx; | |
9241 | child_ctx->parent_gen = parent_ctx->generation; | |
9242 | } | |
9243 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9244 | } |
9245 | ||
c5ed5145 | 9246 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9247 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9248 | |
25346b93 | 9249 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9250 | put_ctx(parent_ctx); |
ad3a37de | 9251 | |
6ab423e0 | 9252 | return ret; |
9b51f66d IM |
9253 | } |
9254 | ||
8dc85d54 PZ |
9255 | /* |
9256 | * Initialize the perf_event context in task_struct | |
9257 | */ | |
9258 | int perf_event_init_task(struct task_struct *child) | |
9259 | { | |
9260 | int ctxn, ret; | |
9261 | ||
8550d7cb ON |
9262 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9263 | mutex_init(&child->perf_event_mutex); | |
9264 | INIT_LIST_HEAD(&child->perf_event_list); | |
9265 | ||
8dc85d54 PZ |
9266 | for_each_task_context_nr(ctxn) { |
9267 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9268 | if (ret) { |
9269 | perf_event_free_task(child); | |
8dc85d54 | 9270 | return ret; |
6c72e350 | 9271 | } |
8dc85d54 PZ |
9272 | } |
9273 | ||
9274 | return 0; | |
9275 | } | |
9276 | ||
220b140b PM |
9277 | static void __init perf_event_init_all_cpus(void) |
9278 | { | |
b28ab83c | 9279 | struct swevent_htable *swhash; |
220b140b | 9280 | int cpu; |
220b140b PM |
9281 | |
9282 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9283 | swhash = &per_cpu(swevent_htable, cpu); |
9284 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9285 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9286 | } |
9287 | } | |
9288 | ||
0db0628d | 9289 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9290 | { |
108b02cf | 9291 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9292 | |
b28ab83c | 9293 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 9294 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
9295 | struct swevent_hlist *hlist; |
9296 | ||
b28ab83c PZ |
9297 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9298 | WARN_ON(!hlist); | |
9299 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9300 | } |
b28ab83c | 9301 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9302 | } |
9303 | ||
2965faa5 | 9304 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9305 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9306 | { |
108b02cf | 9307 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9308 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9309 | struct perf_event *event; | |
0793a61d | 9310 | |
fae3fde6 PZ |
9311 | raw_spin_lock(&ctx->lock); |
9312 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9313 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9314 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9315 | } |
108b02cf PZ |
9316 | |
9317 | static void perf_event_exit_cpu_context(int cpu) | |
9318 | { | |
9319 | struct perf_event_context *ctx; | |
9320 | struct pmu *pmu; | |
9321 | int idx; | |
9322 | ||
9323 | idx = srcu_read_lock(&pmus_srcu); | |
9324 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9325 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9326 | |
9327 | mutex_lock(&ctx->mutex); | |
9328 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9329 | mutex_unlock(&ctx->mutex); | |
9330 | } | |
9331 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9332 | } |
9333 | ||
cdd6c482 | 9334 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9335 | { |
e3703f8c | 9336 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9337 | } |
9338 | #else | |
cdd6c482 | 9339 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9340 | #endif |
9341 | ||
c277443c PZ |
9342 | static int |
9343 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9344 | { | |
9345 | int cpu; | |
9346 | ||
9347 | for_each_online_cpu(cpu) | |
9348 | perf_event_exit_cpu(cpu); | |
9349 | ||
9350 | return NOTIFY_OK; | |
9351 | } | |
9352 | ||
9353 | /* | |
9354 | * Run the perf reboot notifier at the very last possible moment so that | |
9355 | * the generic watchdog code runs as long as possible. | |
9356 | */ | |
9357 | static struct notifier_block perf_reboot_notifier = { | |
9358 | .notifier_call = perf_reboot, | |
9359 | .priority = INT_MIN, | |
9360 | }; | |
9361 | ||
0db0628d | 9362 | static int |
0793a61d TG |
9363 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9364 | { | |
9365 | unsigned int cpu = (long)hcpu; | |
9366 | ||
4536e4d1 | 9367 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9368 | |
9369 | case CPU_UP_PREPARE: | |
cdd6c482 | 9370 | perf_event_init_cpu(cpu); |
0793a61d TG |
9371 | break; |
9372 | ||
9373 | case CPU_DOWN_PREPARE: | |
cdd6c482 | 9374 | perf_event_exit_cpu(cpu); |
0793a61d | 9375 | break; |
0793a61d TG |
9376 | default: |
9377 | break; | |
9378 | } | |
9379 | ||
9380 | return NOTIFY_OK; | |
9381 | } | |
9382 | ||
cdd6c482 | 9383 | void __init perf_event_init(void) |
0793a61d | 9384 | { |
3c502e7a JW |
9385 | int ret; |
9386 | ||
2e80a82a PZ |
9387 | idr_init(&pmu_idr); |
9388 | ||
220b140b | 9389 | perf_event_init_all_cpus(); |
b0a873eb | 9390 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9391 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9392 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9393 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9394 | perf_tp_register(); |
9395 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9396 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9397 | |
9398 | ret = init_hw_breakpoint(); | |
9399 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 9400 | |
b01c3a00 JO |
9401 | /* |
9402 | * Build time assertion that we keep the data_head at the intended | |
9403 | * location. IOW, validation we got the __reserved[] size right. | |
9404 | */ | |
9405 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9406 | != 1024); | |
0793a61d | 9407 | } |
abe43400 | 9408 | |
fd979c01 CS |
9409 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9410 | char *page) | |
9411 | { | |
9412 | struct perf_pmu_events_attr *pmu_attr = | |
9413 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9414 | ||
9415 | if (pmu_attr->event_str) | |
9416 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9417 | ||
9418 | return 0; | |
9419 | } | |
9420 | ||
abe43400 PZ |
9421 | static int __init perf_event_sysfs_init(void) |
9422 | { | |
9423 | struct pmu *pmu; | |
9424 | int ret; | |
9425 | ||
9426 | mutex_lock(&pmus_lock); | |
9427 | ||
9428 | ret = bus_register(&pmu_bus); | |
9429 | if (ret) | |
9430 | goto unlock; | |
9431 | ||
9432 | list_for_each_entry(pmu, &pmus, entry) { | |
9433 | if (!pmu->name || pmu->type < 0) | |
9434 | continue; | |
9435 | ||
9436 | ret = pmu_dev_alloc(pmu); | |
9437 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9438 | } | |
9439 | pmu_bus_running = 1; | |
9440 | ret = 0; | |
9441 | ||
9442 | unlock: | |
9443 | mutex_unlock(&pmus_lock); | |
9444 | ||
9445 | return ret; | |
9446 | } | |
9447 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9448 | |
9449 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9450 | static struct cgroup_subsys_state * |
9451 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9452 | { |
9453 | struct perf_cgroup *jc; | |
e5d1367f | 9454 | |
1b15d055 | 9455 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9456 | if (!jc) |
9457 | return ERR_PTR(-ENOMEM); | |
9458 | ||
e5d1367f SE |
9459 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9460 | if (!jc->info) { | |
9461 | kfree(jc); | |
9462 | return ERR_PTR(-ENOMEM); | |
9463 | } | |
9464 | ||
e5d1367f SE |
9465 | return &jc->css; |
9466 | } | |
9467 | ||
eb95419b | 9468 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9469 | { |
eb95419b TH |
9470 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9471 | ||
e5d1367f SE |
9472 | free_percpu(jc->info); |
9473 | kfree(jc); | |
9474 | } | |
9475 | ||
9476 | static int __perf_cgroup_move(void *info) | |
9477 | { | |
9478 | struct task_struct *task = info; | |
ddaaf4e2 | 9479 | rcu_read_lock(); |
e5d1367f | 9480 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9481 | rcu_read_unlock(); |
e5d1367f SE |
9482 | return 0; |
9483 | } | |
9484 | ||
1f7dd3e5 | 9485 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9486 | { |
bb9d97b6 | 9487 | struct task_struct *task; |
1f7dd3e5 | 9488 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9489 | |
1f7dd3e5 | 9490 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9491 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9492 | } |
9493 | ||
073219e9 | 9494 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9495 | .css_alloc = perf_cgroup_css_alloc, |
9496 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9497 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9498 | }; |
9499 | #endif /* CONFIG_CGROUP_PERF */ |