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, | |
317 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
318 | }; | |
319 | ||
e5d1367f SE |
320 | /* |
321 | * perf_sched_events : >0 events exist | |
322 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
323 | */ | |
c5905afb | 324 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 325 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 326 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 327 | |
cdd6c482 IM |
328 | static atomic_t nr_mmap_events __read_mostly; |
329 | static atomic_t nr_comm_events __read_mostly; | |
330 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 331 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 332 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 333 | |
108b02cf PZ |
334 | static LIST_HEAD(pmus); |
335 | static DEFINE_MUTEX(pmus_lock); | |
336 | static struct srcu_struct pmus_srcu; | |
337 | ||
0764771d | 338 | /* |
cdd6c482 | 339 | * perf event paranoia level: |
0fbdea19 IM |
340 | * -1 - not paranoid at all |
341 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 342 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 343 | * 2 - disallow kernel profiling for unpriv |
0764771d | 344 | */ |
cdd6c482 | 345 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 346 | |
20443384 FW |
347 | /* Minimum for 512 kiB + 1 user control page */ |
348 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
349 | |
350 | /* | |
cdd6c482 | 351 | * max perf event sample rate |
df58ab24 | 352 | */ |
14c63f17 DH |
353 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
354 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
355 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
356 | ||
357 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
358 | ||
359 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
360 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
361 | ||
d9494cb4 PZ |
362 | static int perf_sample_allowed_ns __read_mostly = |
363 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 364 | |
18ab2cd3 | 365 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
366 | { |
367 | u64 tmp = perf_sample_period_ns; | |
368 | ||
369 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 370 | do_div(tmp, 100); |
d9494cb4 | 371 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 372 | } |
163ec435 | 373 | |
9e630205 SE |
374 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
375 | ||
163ec435 PZ |
376 | int perf_proc_update_handler(struct ctl_table *table, int write, |
377 | void __user *buffer, size_t *lenp, | |
378 | loff_t *ppos) | |
379 | { | |
723478c8 | 380 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
381 | |
382 | if (ret || !write) | |
383 | return ret; | |
384 | ||
385 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
386 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
387 | update_perf_cpu_limits(); | |
388 | ||
389 | return 0; | |
390 | } | |
391 | ||
392 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
393 | ||
394 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
395 | void __user *buffer, size_t *lenp, | |
396 | loff_t *ppos) | |
397 | { | |
398 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
399 | ||
400 | if (ret || !write) | |
401 | return ret; | |
402 | ||
403 | update_perf_cpu_limits(); | |
163ec435 PZ |
404 | |
405 | return 0; | |
406 | } | |
1ccd1549 | 407 | |
14c63f17 DH |
408 | /* |
409 | * perf samples are done in some very critical code paths (NMIs). | |
410 | * If they take too much CPU time, the system can lock up and not | |
411 | * get any real work done. This will drop the sample rate when | |
412 | * we detect that events are taking too long. | |
413 | */ | |
414 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 415 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 416 | |
6a02ad66 | 417 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 418 | { |
6a02ad66 | 419 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 420 | u64 avg_local_sample_len; |
e5302920 | 421 | u64 local_samples_len; |
6a02ad66 | 422 | |
4a32fea9 | 423 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
424 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
425 | ||
426 | printk_ratelimited(KERN_WARNING | |
427 | "perf interrupt took too long (%lld > %lld), lowering " | |
428 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 429 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
430 | sysctl_perf_event_sample_rate); |
431 | } | |
432 | ||
433 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
434 | ||
435 | void perf_sample_event_took(u64 sample_len_ns) | |
436 | { | |
d9494cb4 | 437 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
438 | u64 avg_local_sample_len; |
439 | u64 local_samples_len; | |
14c63f17 | 440 | |
d9494cb4 | 441 | if (allowed_ns == 0) |
14c63f17 DH |
442 | return; |
443 | ||
444 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 445 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
446 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
447 | local_samples_len += sample_len_ns; | |
4a32fea9 | 448 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
449 | |
450 | /* | |
451 | * note: this will be biased artifically low until we have | |
452 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
453 | * from having to maintain a count. | |
454 | */ | |
455 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
456 | ||
d9494cb4 | 457 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
458 | return; |
459 | ||
460 | if (max_samples_per_tick <= 1) | |
461 | return; | |
462 | ||
463 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
464 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
465 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
466 | ||
14c63f17 | 467 | update_perf_cpu_limits(); |
6a02ad66 | 468 | |
cd578abb PZ |
469 | if (!irq_work_queue(&perf_duration_work)) { |
470 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
471 | "kernel.perf_event_max_sample_rate to %d\n", | |
472 | avg_local_sample_len, allowed_ns >> 1, | |
473 | sysctl_perf_event_sample_rate); | |
474 | } | |
14c63f17 DH |
475 | } |
476 | ||
cdd6c482 | 477 | static atomic64_t perf_event_id; |
a96bbc16 | 478 | |
0b3fcf17 SE |
479 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
480 | enum event_type_t event_type); | |
481 | ||
482 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
483 | enum event_type_t event_type, |
484 | struct task_struct *task); | |
485 | ||
486 | static void update_context_time(struct perf_event_context *ctx); | |
487 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 488 | |
cdd6c482 | 489 | void __weak perf_event_print_debug(void) { } |
0793a61d | 490 | |
84c79910 | 491 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 492 | { |
84c79910 | 493 | return "pmu"; |
0793a61d TG |
494 | } |
495 | ||
0b3fcf17 SE |
496 | static inline u64 perf_clock(void) |
497 | { | |
498 | return local_clock(); | |
499 | } | |
500 | ||
34f43927 PZ |
501 | static inline u64 perf_event_clock(struct perf_event *event) |
502 | { | |
503 | return event->clock(); | |
504 | } | |
505 | ||
e5d1367f SE |
506 | #ifdef CONFIG_CGROUP_PERF |
507 | ||
e5d1367f SE |
508 | static inline bool |
509 | perf_cgroup_match(struct perf_event *event) | |
510 | { | |
511 | struct perf_event_context *ctx = event->ctx; | |
512 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
513 | ||
ef824fa1 TH |
514 | /* @event doesn't care about cgroup */ |
515 | if (!event->cgrp) | |
516 | return true; | |
517 | ||
518 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
519 | if (!cpuctx->cgrp) | |
520 | return false; | |
521 | ||
522 | /* | |
523 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
524 | * also enabled for all its descendant cgroups. If @cpuctx's | |
525 | * cgroup is a descendant of @event's (the test covers identity | |
526 | * case), it's a match. | |
527 | */ | |
528 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
529 | event->cgrp->css.cgroup); | |
e5d1367f SE |
530 | } |
531 | ||
e5d1367f SE |
532 | static inline void perf_detach_cgroup(struct perf_event *event) |
533 | { | |
4e2ba650 | 534 | css_put(&event->cgrp->css); |
e5d1367f SE |
535 | event->cgrp = NULL; |
536 | } | |
537 | ||
538 | static inline int is_cgroup_event(struct perf_event *event) | |
539 | { | |
540 | return event->cgrp != NULL; | |
541 | } | |
542 | ||
543 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
544 | { | |
545 | struct perf_cgroup_info *t; | |
546 | ||
547 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
548 | return t->time; | |
549 | } | |
550 | ||
551 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
552 | { | |
553 | struct perf_cgroup_info *info; | |
554 | u64 now; | |
555 | ||
556 | now = perf_clock(); | |
557 | ||
558 | info = this_cpu_ptr(cgrp->info); | |
559 | ||
560 | info->time += now - info->timestamp; | |
561 | info->timestamp = now; | |
562 | } | |
563 | ||
564 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
565 | { | |
566 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
567 | if (cgrp_out) | |
568 | __update_cgrp_time(cgrp_out); | |
569 | } | |
570 | ||
571 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
572 | { | |
3f7cce3c SE |
573 | struct perf_cgroup *cgrp; |
574 | ||
e5d1367f | 575 | /* |
3f7cce3c SE |
576 | * ensure we access cgroup data only when needed and |
577 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 578 | */ |
3f7cce3c | 579 | if (!is_cgroup_event(event)) |
e5d1367f SE |
580 | return; |
581 | ||
614e4c4e | 582 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
583 | /* |
584 | * Do not update time when cgroup is not active | |
585 | */ | |
586 | if (cgrp == event->cgrp) | |
587 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
588 | } |
589 | ||
590 | static inline void | |
3f7cce3c SE |
591 | perf_cgroup_set_timestamp(struct task_struct *task, |
592 | struct perf_event_context *ctx) | |
e5d1367f SE |
593 | { |
594 | struct perf_cgroup *cgrp; | |
595 | struct perf_cgroup_info *info; | |
596 | ||
3f7cce3c SE |
597 | /* |
598 | * ctx->lock held by caller | |
599 | * ensure we do not access cgroup data | |
600 | * unless we have the cgroup pinned (css_get) | |
601 | */ | |
602 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
603 | return; |
604 | ||
614e4c4e | 605 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 606 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 607 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
608 | } |
609 | ||
610 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
611 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
612 | ||
613 | /* | |
614 | * reschedule events based on the cgroup constraint of task. | |
615 | * | |
616 | * mode SWOUT : schedule out everything | |
617 | * mode SWIN : schedule in based on cgroup for next | |
618 | */ | |
18ab2cd3 | 619 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
620 | { |
621 | struct perf_cpu_context *cpuctx; | |
622 | struct pmu *pmu; | |
623 | unsigned long flags; | |
624 | ||
625 | /* | |
626 | * disable interrupts to avoid geting nr_cgroup | |
627 | * changes via __perf_event_disable(). Also | |
628 | * avoids preemption. | |
629 | */ | |
630 | local_irq_save(flags); | |
631 | ||
632 | /* | |
633 | * we reschedule only in the presence of cgroup | |
634 | * constrained events. | |
635 | */ | |
e5d1367f SE |
636 | |
637 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 638 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
639 | if (cpuctx->unique_pmu != pmu) |
640 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 641 | |
e5d1367f SE |
642 | /* |
643 | * perf_cgroup_events says at least one | |
644 | * context on this CPU has cgroup events. | |
645 | * | |
646 | * ctx->nr_cgroups reports the number of cgroup | |
647 | * events for a context. | |
648 | */ | |
649 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
650 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
651 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
652 | |
653 | if (mode & PERF_CGROUP_SWOUT) { | |
654 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
655 | /* | |
656 | * must not be done before ctxswout due | |
657 | * to event_filter_match() in event_sched_out() | |
658 | */ | |
659 | cpuctx->cgrp = NULL; | |
660 | } | |
661 | ||
662 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 663 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
664 | /* |
665 | * set cgrp before ctxsw in to allow | |
666 | * event_filter_match() to not have to pass | |
667 | * task around | |
614e4c4e SE |
668 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
669 | * because cgorup events are only per-cpu | |
e5d1367f | 670 | */ |
614e4c4e | 671 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
672 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
673 | } | |
facc4307 PZ |
674 | perf_pmu_enable(cpuctx->ctx.pmu); |
675 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 676 | } |
e5d1367f SE |
677 | } |
678 | ||
e5d1367f SE |
679 | local_irq_restore(flags); |
680 | } | |
681 | ||
a8d757ef SE |
682 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
683 | struct task_struct *next) | |
e5d1367f | 684 | { |
a8d757ef SE |
685 | struct perf_cgroup *cgrp1; |
686 | struct perf_cgroup *cgrp2 = NULL; | |
687 | ||
ddaaf4e2 | 688 | rcu_read_lock(); |
a8d757ef SE |
689 | /* |
690 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
691 | * we do not need to pass the ctx here because we know |
692 | * we are holding the rcu lock | |
a8d757ef | 693 | */ |
614e4c4e | 694 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 695 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
696 | |
697 | /* | |
698 | * only schedule out current cgroup events if we know | |
699 | * that we are switching to a different cgroup. Otherwise, | |
700 | * do no touch the cgroup events. | |
701 | */ | |
702 | if (cgrp1 != cgrp2) | |
703 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
704 | |
705 | rcu_read_unlock(); | |
e5d1367f SE |
706 | } |
707 | ||
a8d757ef SE |
708 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
709 | struct task_struct *task) | |
e5d1367f | 710 | { |
a8d757ef SE |
711 | struct perf_cgroup *cgrp1; |
712 | struct perf_cgroup *cgrp2 = NULL; | |
713 | ||
ddaaf4e2 | 714 | rcu_read_lock(); |
a8d757ef SE |
715 | /* |
716 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
717 | * we do not need to pass the ctx here because we know |
718 | * we are holding the rcu lock | |
a8d757ef | 719 | */ |
614e4c4e | 720 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 721 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
722 | |
723 | /* | |
724 | * only need to schedule in cgroup events if we are changing | |
725 | * cgroup during ctxsw. Cgroup events were not scheduled | |
726 | * out of ctxsw out if that was not the case. | |
727 | */ | |
728 | if (cgrp1 != cgrp2) | |
729 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
730 | |
731 | rcu_read_unlock(); | |
e5d1367f SE |
732 | } |
733 | ||
734 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
735 | struct perf_event_attr *attr, | |
736 | struct perf_event *group_leader) | |
737 | { | |
738 | struct perf_cgroup *cgrp; | |
739 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
740 | struct fd f = fdget(fd); |
741 | int ret = 0; | |
e5d1367f | 742 | |
2903ff01 | 743 | if (!f.file) |
e5d1367f SE |
744 | return -EBADF; |
745 | ||
b583043e | 746 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 747 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
748 | if (IS_ERR(css)) { |
749 | ret = PTR_ERR(css); | |
750 | goto out; | |
751 | } | |
e5d1367f SE |
752 | |
753 | cgrp = container_of(css, struct perf_cgroup, css); | |
754 | event->cgrp = cgrp; | |
755 | ||
756 | /* | |
757 | * all events in a group must monitor | |
758 | * the same cgroup because a task belongs | |
759 | * to only one perf cgroup at a time | |
760 | */ | |
761 | if (group_leader && group_leader->cgrp != cgrp) { | |
762 | perf_detach_cgroup(event); | |
763 | ret = -EINVAL; | |
e5d1367f | 764 | } |
3db272c0 | 765 | out: |
2903ff01 | 766 | fdput(f); |
e5d1367f SE |
767 | return ret; |
768 | } | |
769 | ||
770 | static inline void | |
771 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
772 | { | |
773 | struct perf_cgroup_info *t; | |
774 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
775 | event->shadow_ctx_time = now - t->timestamp; | |
776 | } | |
777 | ||
778 | static inline void | |
779 | perf_cgroup_defer_enabled(struct perf_event *event) | |
780 | { | |
781 | /* | |
782 | * when the current task's perf cgroup does not match | |
783 | * the event's, we need to remember to call the | |
784 | * perf_mark_enable() function the first time a task with | |
785 | * a matching perf cgroup is scheduled in. | |
786 | */ | |
787 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
788 | event->cgrp_defer_enabled = 1; | |
789 | } | |
790 | ||
791 | static inline void | |
792 | perf_cgroup_mark_enabled(struct perf_event *event, | |
793 | struct perf_event_context *ctx) | |
794 | { | |
795 | struct perf_event *sub; | |
796 | u64 tstamp = perf_event_time(event); | |
797 | ||
798 | if (!event->cgrp_defer_enabled) | |
799 | return; | |
800 | ||
801 | event->cgrp_defer_enabled = 0; | |
802 | ||
803 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
804 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
805 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
806 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
807 | sub->cgrp_defer_enabled = 0; | |
808 | } | |
809 | } | |
810 | } | |
811 | #else /* !CONFIG_CGROUP_PERF */ | |
812 | ||
813 | static inline bool | |
814 | perf_cgroup_match(struct perf_event *event) | |
815 | { | |
816 | return true; | |
817 | } | |
818 | ||
819 | static inline void perf_detach_cgroup(struct perf_event *event) | |
820 | {} | |
821 | ||
822 | static inline int is_cgroup_event(struct perf_event *event) | |
823 | { | |
824 | return 0; | |
825 | } | |
826 | ||
827 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
828 | { | |
829 | return 0; | |
830 | } | |
831 | ||
832 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
833 | { | |
834 | } | |
835 | ||
836 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
837 | { | |
838 | } | |
839 | ||
a8d757ef SE |
840 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
841 | struct task_struct *next) | |
e5d1367f SE |
842 | { |
843 | } | |
844 | ||
a8d757ef SE |
845 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
846 | struct task_struct *task) | |
e5d1367f SE |
847 | { |
848 | } | |
849 | ||
850 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
851 | struct perf_event_attr *attr, | |
852 | struct perf_event *group_leader) | |
853 | { | |
854 | return -EINVAL; | |
855 | } | |
856 | ||
857 | static inline void | |
3f7cce3c SE |
858 | perf_cgroup_set_timestamp(struct task_struct *task, |
859 | struct perf_event_context *ctx) | |
e5d1367f SE |
860 | { |
861 | } | |
862 | ||
863 | void | |
864 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
865 | { | |
866 | } | |
867 | ||
868 | static inline void | |
869 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
870 | { | |
871 | } | |
872 | ||
873 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
874 | { | |
875 | return 0; | |
876 | } | |
877 | ||
878 | static inline void | |
879 | perf_cgroup_defer_enabled(struct perf_event *event) | |
880 | { | |
881 | } | |
882 | ||
883 | static inline void | |
884 | perf_cgroup_mark_enabled(struct perf_event *event, | |
885 | struct perf_event_context *ctx) | |
886 | { | |
887 | } | |
888 | #endif | |
889 | ||
9e630205 SE |
890 | /* |
891 | * set default to be dependent on timer tick just | |
892 | * like original code | |
893 | */ | |
894 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
895 | /* | |
896 | * function must be called with interrupts disbled | |
897 | */ | |
272325c4 | 898 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
899 | { |
900 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
901 | int rotations = 0; |
902 | ||
903 | WARN_ON(!irqs_disabled()); | |
904 | ||
905 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
906 | rotations = perf_rotate_context(cpuctx); |
907 | ||
4cfafd30 PZ |
908 | raw_spin_lock(&cpuctx->hrtimer_lock); |
909 | if (rotations) | |
9e630205 | 910 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
911 | else |
912 | cpuctx->hrtimer_active = 0; | |
913 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 914 | |
4cfafd30 | 915 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
916 | } |
917 | ||
272325c4 | 918 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 919 | { |
272325c4 | 920 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 921 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 922 | u64 interval; |
9e630205 SE |
923 | |
924 | /* no multiplexing needed for SW PMU */ | |
925 | if (pmu->task_ctx_nr == perf_sw_context) | |
926 | return; | |
927 | ||
62b85639 SE |
928 | /* |
929 | * check default is sane, if not set then force to | |
930 | * default interval (1/tick) | |
931 | */ | |
272325c4 PZ |
932 | interval = pmu->hrtimer_interval_ms; |
933 | if (interval < 1) | |
934 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 935 | |
272325c4 | 936 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 937 | |
4cfafd30 PZ |
938 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
939 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 940 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
941 | } |
942 | ||
272325c4 | 943 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 944 | { |
272325c4 | 945 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 946 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 947 | unsigned long flags; |
9e630205 SE |
948 | |
949 | /* not for SW PMU */ | |
950 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 951 | return 0; |
9e630205 | 952 | |
4cfafd30 PZ |
953 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
954 | if (!cpuctx->hrtimer_active) { | |
955 | cpuctx->hrtimer_active = 1; | |
956 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
957 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
958 | } | |
959 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 960 | |
272325c4 | 961 | return 0; |
9e630205 SE |
962 | } |
963 | ||
33696fc0 | 964 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 965 | { |
33696fc0 PZ |
966 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
967 | if (!(*count)++) | |
968 | pmu->pmu_disable(pmu); | |
9e35ad38 | 969 | } |
9e35ad38 | 970 | |
33696fc0 | 971 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 972 | { |
33696fc0 PZ |
973 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
974 | if (!--(*count)) | |
975 | pmu->pmu_enable(pmu); | |
9e35ad38 | 976 | } |
9e35ad38 | 977 | |
2fde4f94 | 978 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
979 | |
980 | /* | |
2fde4f94 MR |
981 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
982 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
983 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
984 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 985 | */ |
2fde4f94 | 986 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 987 | { |
2fde4f94 | 988 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 989 | |
e9d2b064 | 990 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 991 | |
2fde4f94 MR |
992 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
993 | ||
994 | list_add(&ctx->active_ctx_list, head); | |
995 | } | |
996 | ||
997 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
998 | { | |
999 | WARN_ON(!irqs_disabled()); | |
1000 | ||
1001 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1002 | ||
1003 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1004 | } |
9e35ad38 | 1005 | |
cdd6c482 | 1006 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1007 | { |
e5289d4a | 1008 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1009 | } |
1010 | ||
4af57ef2 YZ |
1011 | static void free_ctx(struct rcu_head *head) |
1012 | { | |
1013 | struct perf_event_context *ctx; | |
1014 | ||
1015 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1016 | kfree(ctx->task_ctx_data); | |
1017 | kfree(ctx); | |
1018 | } | |
1019 | ||
cdd6c482 | 1020 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1021 | { |
564c2b21 PM |
1022 | if (atomic_dec_and_test(&ctx->refcount)) { |
1023 | if (ctx->parent_ctx) | |
1024 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1025 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1026 | put_task_struct(ctx->task); |
4af57ef2 | 1027 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1028 | } |
a63eaf34 PM |
1029 | } |
1030 | ||
f63a8daa PZ |
1031 | /* |
1032 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1033 | * perf_pmu_migrate_context() we need some magic. | |
1034 | * | |
1035 | * Those places that change perf_event::ctx will hold both | |
1036 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1037 | * | |
8b10c5e2 PZ |
1038 | * Lock ordering is by mutex address. There are two other sites where |
1039 | * perf_event_context::mutex nests and those are: | |
1040 | * | |
1041 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1042 | * perf_event_exit_event() |
1043 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1044 | * |
1045 | * - perf_event_init_context() [ parent, 0 ] | |
1046 | * inherit_task_group() | |
1047 | * inherit_group() | |
1048 | * inherit_event() | |
1049 | * perf_event_alloc() | |
1050 | * perf_init_event() | |
1051 | * perf_try_init_event() [ child , 1 ] | |
1052 | * | |
1053 | * While it appears there is an obvious deadlock here -- the parent and child | |
1054 | * nesting levels are inverted between the two. This is in fact safe because | |
1055 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1056 | * spawning task cannot (yet) exit. | |
1057 | * | |
1058 | * But remember that that these are parent<->child context relations, and | |
1059 | * migration does not affect children, therefore these two orderings should not | |
1060 | * interact. | |
f63a8daa PZ |
1061 | * |
1062 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1063 | * because the sys_perf_event_open() case will install a new event and break | |
1064 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1065 | * concerned with cpuctx and that doesn't have children. | |
1066 | * | |
1067 | * The places that change perf_event::ctx will issue: | |
1068 | * | |
1069 | * perf_remove_from_context(); | |
1070 | * synchronize_rcu(); | |
1071 | * perf_install_in_context(); | |
1072 | * | |
1073 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1074 | * quiesce the event, after which we can install it in the new location. This | |
1075 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1076 | * while in transit. Therefore all such accessors should also acquire | |
1077 | * perf_event_context::mutex to serialize against this. | |
1078 | * | |
1079 | * However; because event->ctx can change while we're waiting to acquire | |
1080 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1081 | * function. | |
1082 | * | |
1083 | * Lock order: | |
1084 | * task_struct::perf_event_mutex | |
1085 | * perf_event_context::mutex | |
f63a8daa | 1086 | * perf_event::child_mutex; |
07c4a776 | 1087 | * perf_event_context::lock |
f63a8daa PZ |
1088 | * perf_event::mmap_mutex |
1089 | * mmap_sem | |
1090 | */ | |
a83fe28e PZ |
1091 | static struct perf_event_context * |
1092 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1093 | { |
1094 | struct perf_event_context *ctx; | |
1095 | ||
1096 | again: | |
1097 | rcu_read_lock(); | |
1098 | ctx = ACCESS_ONCE(event->ctx); | |
1099 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1100 | rcu_read_unlock(); | |
1101 | goto again; | |
1102 | } | |
1103 | rcu_read_unlock(); | |
1104 | ||
a83fe28e | 1105 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1106 | if (event->ctx != ctx) { |
1107 | mutex_unlock(&ctx->mutex); | |
1108 | put_ctx(ctx); | |
1109 | goto again; | |
1110 | } | |
1111 | ||
1112 | return ctx; | |
1113 | } | |
1114 | ||
a83fe28e PZ |
1115 | static inline struct perf_event_context * |
1116 | perf_event_ctx_lock(struct perf_event *event) | |
1117 | { | |
1118 | return perf_event_ctx_lock_nested(event, 0); | |
1119 | } | |
1120 | ||
f63a8daa PZ |
1121 | static void perf_event_ctx_unlock(struct perf_event *event, |
1122 | struct perf_event_context *ctx) | |
1123 | { | |
1124 | mutex_unlock(&ctx->mutex); | |
1125 | put_ctx(ctx); | |
1126 | } | |
1127 | ||
211de6eb PZ |
1128 | /* |
1129 | * This must be done under the ctx->lock, such as to serialize against | |
1130 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1131 | * calling scheduler related locks and ctx->lock nests inside those. | |
1132 | */ | |
1133 | static __must_check struct perf_event_context * | |
1134 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1135 | { |
211de6eb PZ |
1136 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1137 | ||
1138 | lockdep_assert_held(&ctx->lock); | |
1139 | ||
1140 | if (parent_ctx) | |
71a851b4 | 1141 | ctx->parent_ctx = NULL; |
5a3126d4 | 1142 | ctx->generation++; |
211de6eb PZ |
1143 | |
1144 | return parent_ctx; | |
71a851b4 PZ |
1145 | } |
1146 | ||
6844c09d ACM |
1147 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1148 | { | |
1149 | /* | |
1150 | * only top level events have the pid namespace they were created in | |
1151 | */ | |
1152 | if (event->parent) | |
1153 | event = event->parent; | |
1154 | ||
1155 | return task_tgid_nr_ns(p, event->ns); | |
1156 | } | |
1157 | ||
1158 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1159 | { | |
1160 | /* | |
1161 | * only top level events have the pid namespace they were created in | |
1162 | */ | |
1163 | if (event->parent) | |
1164 | event = event->parent; | |
1165 | ||
1166 | return task_pid_nr_ns(p, event->ns); | |
1167 | } | |
1168 | ||
7f453c24 | 1169 | /* |
cdd6c482 | 1170 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1171 | * to userspace. |
1172 | */ | |
cdd6c482 | 1173 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1174 | { |
cdd6c482 | 1175 | u64 id = event->id; |
7f453c24 | 1176 | |
cdd6c482 IM |
1177 | if (event->parent) |
1178 | id = event->parent->id; | |
7f453c24 PZ |
1179 | |
1180 | return id; | |
1181 | } | |
1182 | ||
25346b93 | 1183 | /* |
cdd6c482 | 1184 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1185 | * |
25346b93 PM |
1186 | * This has to cope with with the fact that until it is locked, |
1187 | * the context could get moved to another task. | |
1188 | */ | |
cdd6c482 | 1189 | static struct perf_event_context * |
8dc85d54 | 1190 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1191 | { |
cdd6c482 | 1192 | struct perf_event_context *ctx; |
25346b93 | 1193 | |
9ed6060d | 1194 | retry: |
058ebd0e PZ |
1195 | /* |
1196 | * One of the few rules of preemptible RCU is that one cannot do | |
1197 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1198 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1199 | * rcu_read_unlock_special(). |
1200 | * | |
1201 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1202 | * side critical section has interrupts disabled. |
058ebd0e | 1203 | */ |
2fd59077 | 1204 | local_irq_save(*flags); |
058ebd0e | 1205 | rcu_read_lock(); |
8dc85d54 | 1206 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1207 | if (ctx) { |
1208 | /* | |
1209 | * If this context is a clone of another, it might | |
1210 | * get swapped for another underneath us by | |
cdd6c482 | 1211 | * perf_event_task_sched_out, though the |
25346b93 PM |
1212 | * rcu_read_lock() protects us from any context |
1213 | * getting freed. Lock the context and check if it | |
1214 | * got swapped before we could get the lock, and retry | |
1215 | * if so. If we locked the right context, then it | |
1216 | * can't get swapped on us any more. | |
1217 | */ | |
2fd59077 | 1218 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1219 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1220 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1221 | rcu_read_unlock(); |
2fd59077 | 1222 | local_irq_restore(*flags); |
25346b93 PM |
1223 | goto retry; |
1224 | } | |
b49a9e7e | 1225 | |
63b6da39 PZ |
1226 | if (ctx->task == TASK_TOMBSTONE || |
1227 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1228 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1229 | ctx = NULL; |
828b6f0e PZ |
1230 | } else { |
1231 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1232 | } |
25346b93 PM |
1233 | } |
1234 | rcu_read_unlock(); | |
2fd59077 PM |
1235 | if (!ctx) |
1236 | local_irq_restore(*flags); | |
25346b93 PM |
1237 | return ctx; |
1238 | } | |
1239 | ||
1240 | /* | |
1241 | * Get the context for a task and increment its pin_count so it | |
1242 | * can't get swapped to another task. This also increments its | |
1243 | * reference count so that the context can't get freed. | |
1244 | */ | |
8dc85d54 PZ |
1245 | static struct perf_event_context * |
1246 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1247 | { |
cdd6c482 | 1248 | struct perf_event_context *ctx; |
25346b93 PM |
1249 | unsigned long flags; |
1250 | ||
8dc85d54 | 1251 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1252 | if (ctx) { |
1253 | ++ctx->pin_count; | |
e625cce1 | 1254 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1255 | } |
1256 | return ctx; | |
1257 | } | |
1258 | ||
cdd6c482 | 1259 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1260 | { |
1261 | unsigned long flags; | |
1262 | ||
e625cce1 | 1263 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1264 | --ctx->pin_count; |
e625cce1 | 1265 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1266 | } |
1267 | ||
f67218c3 PZ |
1268 | /* |
1269 | * Update the record of the current time in a context. | |
1270 | */ | |
1271 | static void update_context_time(struct perf_event_context *ctx) | |
1272 | { | |
1273 | u64 now = perf_clock(); | |
1274 | ||
1275 | ctx->time += now - ctx->timestamp; | |
1276 | ctx->timestamp = now; | |
1277 | } | |
1278 | ||
4158755d SE |
1279 | static u64 perf_event_time(struct perf_event *event) |
1280 | { | |
1281 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1282 | |
1283 | if (is_cgroup_event(event)) | |
1284 | return perf_cgroup_event_time(event); | |
1285 | ||
4158755d SE |
1286 | return ctx ? ctx->time : 0; |
1287 | } | |
1288 | ||
f67218c3 PZ |
1289 | /* |
1290 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1291 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1292 | */ |
1293 | static void update_event_times(struct perf_event *event) | |
1294 | { | |
1295 | struct perf_event_context *ctx = event->ctx; | |
1296 | u64 run_end; | |
1297 | ||
1298 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1299 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1300 | return; | |
e5d1367f SE |
1301 | /* |
1302 | * in cgroup mode, time_enabled represents | |
1303 | * the time the event was enabled AND active | |
1304 | * tasks were in the monitored cgroup. This is | |
1305 | * independent of the activity of the context as | |
1306 | * there may be a mix of cgroup and non-cgroup events. | |
1307 | * | |
1308 | * That is why we treat cgroup events differently | |
1309 | * here. | |
1310 | */ | |
1311 | if (is_cgroup_event(event)) | |
46cd6a7f | 1312 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1313 | else if (ctx->is_active) |
1314 | run_end = ctx->time; | |
acd1d7c1 PZ |
1315 | else |
1316 | run_end = event->tstamp_stopped; | |
1317 | ||
1318 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1319 | |
1320 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1321 | run_end = event->tstamp_stopped; | |
1322 | else | |
4158755d | 1323 | run_end = perf_event_time(event); |
f67218c3 PZ |
1324 | |
1325 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1326 | |
f67218c3 PZ |
1327 | } |
1328 | ||
96c21a46 PZ |
1329 | /* |
1330 | * Update total_time_enabled and total_time_running for all events in a group. | |
1331 | */ | |
1332 | static void update_group_times(struct perf_event *leader) | |
1333 | { | |
1334 | struct perf_event *event; | |
1335 | ||
1336 | update_event_times(leader); | |
1337 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1338 | update_event_times(event); | |
1339 | } | |
1340 | ||
889ff015 FW |
1341 | static struct list_head * |
1342 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1343 | { | |
1344 | if (event->attr.pinned) | |
1345 | return &ctx->pinned_groups; | |
1346 | else | |
1347 | return &ctx->flexible_groups; | |
1348 | } | |
1349 | ||
fccc714b | 1350 | /* |
cdd6c482 | 1351 | * Add a event from the lists for its context. |
fccc714b PZ |
1352 | * Must be called with ctx->mutex and ctx->lock held. |
1353 | */ | |
04289bb9 | 1354 | static void |
cdd6c482 | 1355 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1356 | { |
c994d613 PZ |
1357 | lockdep_assert_held(&ctx->lock); |
1358 | ||
8a49542c PZ |
1359 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1360 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1361 | |
1362 | /* | |
8a49542c PZ |
1363 | * If we're a stand alone event or group leader, we go to the context |
1364 | * list, group events are kept attached to the group so that | |
1365 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1366 | */ |
8a49542c | 1367 | if (event->group_leader == event) { |
889ff015 FW |
1368 | struct list_head *list; |
1369 | ||
d6f962b5 FW |
1370 | if (is_software_event(event)) |
1371 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1372 | ||
889ff015 FW |
1373 | list = ctx_group_list(event, ctx); |
1374 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1375 | } |
592903cd | 1376 | |
08309379 | 1377 | if (is_cgroup_event(event)) |
e5d1367f | 1378 | ctx->nr_cgroups++; |
e5d1367f | 1379 | |
cdd6c482 IM |
1380 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1381 | ctx->nr_events++; | |
1382 | if (event->attr.inherit_stat) | |
bfbd3381 | 1383 | ctx->nr_stat++; |
5a3126d4 PZ |
1384 | |
1385 | ctx->generation++; | |
04289bb9 IM |
1386 | } |
1387 | ||
0231bb53 JO |
1388 | /* |
1389 | * Initialize event state based on the perf_event_attr::disabled. | |
1390 | */ | |
1391 | static inline void perf_event__state_init(struct perf_event *event) | |
1392 | { | |
1393 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1394 | PERF_EVENT_STATE_INACTIVE; | |
1395 | } | |
1396 | ||
a723968c | 1397 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1398 | { |
1399 | int entry = sizeof(u64); /* value */ | |
1400 | int size = 0; | |
1401 | int nr = 1; | |
1402 | ||
1403 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1404 | size += sizeof(u64); | |
1405 | ||
1406 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1407 | size += sizeof(u64); | |
1408 | ||
1409 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1410 | entry += sizeof(u64); | |
1411 | ||
1412 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1413 | nr += nr_siblings; |
c320c7b7 ACM |
1414 | size += sizeof(u64); |
1415 | } | |
1416 | ||
1417 | size += entry * nr; | |
1418 | event->read_size = size; | |
1419 | } | |
1420 | ||
a723968c | 1421 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1422 | { |
1423 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1424 | u16 size = 0; |
1425 | ||
c320c7b7 ACM |
1426 | if (sample_type & PERF_SAMPLE_IP) |
1427 | size += sizeof(data->ip); | |
1428 | ||
6844c09d ACM |
1429 | if (sample_type & PERF_SAMPLE_ADDR) |
1430 | size += sizeof(data->addr); | |
1431 | ||
1432 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1433 | size += sizeof(data->period); | |
1434 | ||
c3feedf2 AK |
1435 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1436 | size += sizeof(data->weight); | |
1437 | ||
6844c09d ACM |
1438 | if (sample_type & PERF_SAMPLE_READ) |
1439 | size += event->read_size; | |
1440 | ||
d6be9ad6 SE |
1441 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1442 | size += sizeof(data->data_src.val); | |
1443 | ||
fdfbbd07 AK |
1444 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1445 | size += sizeof(data->txn); | |
1446 | ||
6844c09d ACM |
1447 | event->header_size = size; |
1448 | } | |
1449 | ||
a723968c PZ |
1450 | /* |
1451 | * Called at perf_event creation and when events are attached/detached from a | |
1452 | * group. | |
1453 | */ | |
1454 | static void perf_event__header_size(struct perf_event *event) | |
1455 | { | |
1456 | __perf_event_read_size(event, | |
1457 | event->group_leader->nr_siblings); | |
1458 | __perf_event_header_size(event, event->attr.sample_type); | |
1459 | } | |
1460 | ||
6844c09d ACM |
1461 | static void perf_event__id_header_size(struct perf_event *event) |
1462 | { | |
1463 | struct perf_sample_data *data; | |
1464 | u64 sample_type = event->attr.sample_type; | |
1465 | u16 size = 0; | |
1466 | ||
c320c7b7 ACM |
1467 | if (sample_type & PERF_SAMPLE_TID) |
1468 | size += sizeof(data->tid_entry); | |
1469 | ||
1470 | if (sample_type & PERF_SAMPLE_TIME) | |
1471 | size += sizeof(data->time); | |
1472 | ||
ff3d527c AH |
1473 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1474 | size += sizeof(data->id); | |
1475 | ||
c320c7b7 ACM |
1476 | if (sample_type & PERF_SAMPLE_ID) |
1477 | size += sizeof(data->id); | |
1478 | ||
1479 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1480 | size += sizeof(data->stream_id); | |
1481 | ||
1482 | if (sample_type & PERF_SAMPLE_CPU) | |
1483 | size += sizeof(data->cpu_entry); | |
1484 | ||
6844c09d | 1485 | event->id_header_size = size; |
c320c7b7 ACM |
1486 | } |
1487 | ||
a723968c PZ |
1488 | static bool perf_event_validate_size(struct perf_event *event) |
1489 | { | |
1490 | /* | |
1491 | * The values computed here will be over-written when we actually | |
1492 | * attach the event. | |
1493 | */ | |
1494 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1495 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1496 | perf_event__id_header_size(event); | |
1497 | ||
1498 | /* | |
1499 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1500 | * Conservative limit to allow for callchains and other variable fields. | |
1501 | */ | |
1502 | if (event->read_size + event->header_size + | |
1503 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1504 | return false; | |
1505 | ||
1506 | return true; | |
1507 | } | |
1508 | ||
8a49542c PZ |
1509 | static void perf_group_attach(struct perf_event *event) |
1510 | { | |
c320c7b7 | 1511 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1512 | |
74c3337c PZ |
1513 | /* |
1514 | * We can have double attach due to group movement in perf_event_open. | |
1515 | */ | |
1516 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1517 | return; | |
1518 | ||
8a49542c PZ |
1519 | event->attach_state |= PERF_ATTACH_GROUP; |
1520 | ||
1521 | if (group_leader == event) | |
1522 | return; | |
1523 | ||
652884fe PZ |
1524 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1525 | ||
8a49542c PZ |
1526 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1527 | !is_software_event(event)) | |
1528 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1529 | ||
1530 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1531 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1532 | |
1533 | perf_event__header_size(group_leader); | |
1534 | ||
1535 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1536 | perf_event__header_size(pos); | |
8a49542c PZ |
1537 | } |
1538 | ||
a63eaf34 | 1539 | /* |
cdd6c482 | 1540 | * Remove a event from the lists for its context. |
fccc714b | 1541 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1542 | */ |
04289bb9 | 1543 | static void |
cdd6c482 | 1544 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1545 | { |
68cacd29 | 1546 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1547 | |
1548 | WARN_ON_ONCE(event->ctx != ctx); | |
1549 | lockdep_assert_held(&ctx->lock); | |
1550 | ||
8a49542c PZ |
1551 | /* |
1552 | * We can have double detach due to exit/hot-unplug + close. | |
1553 | */ | |
1554 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1555 | return; |
8a49542c PZ |
1556 | |
1557 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1558 | ||
68cacd29 | 1559 | if (is_cgroup_event(event)) { |
e5d1367f | 1560 | ctx->nr_cgroups--; |
70a01657 PZ |
1561 | /* |
1562 | * Because cgroup events are always per-cpu events, this will | |
1563 | * always be called from the right CPU. | |
1564 | */ | |
68cacd29 SE |
1565 | cpuctx = __get_cpu_context(ctx); |
1566 | /* | |
70a01657 PZ |
1567 | * If there are no more cgroup events then clear cgrp to avoid |
1568 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1569 | */ |
1570 | if (!ctx->nr_cgroups) | |
1571 | cpuctx->cgrp = NULL; | |
1572 | } | |
e5d1367f | 1573 | |
cdd6c482 IM |
1574 | ctx->nr_events--; |
1575 | if (event->attr.inherit_stat) | |
bfbd3381 | 1576 | ctx->nr_stat--; |
8bc20959 | 1577 | |
cdd6c482 | 1578 | list_del_rcu(&event->event_entry); |
04289bb9 | 1579 | |
8a49542c PZ |
1580 | if (event->group_leader == event) |
1581 | list_del_init(&event->group_entry); | |
5c148194 | 1582 | |
96c21a46 | 1583 | update_group_times(event); |
b2e74a26 SE |
1584 | |
1585 | /* | |
1586 | * If event was in error state, then keep it | |
1587 | * that way, otherwise bogus counts will be | |
1588 | * returned on read(). The only way to get out | |
1589 | * of error state is by explicit re-enabling | |
1590 | * of the event | |
1591 | */ | |
1592 | if (event->state > PERF_EVENT_STATE_OFF) | |
1593 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1594 | |
1595 | ctx->generation++; | |
050735b0 PZ |
1596 | } |
1597 | ||
8a49542c | 1598 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1599 | { |
1600 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1601 | struct list_head *list = NULL; |
1602 | ||
1603 | /* | |
1604 | * We can have double detach due to exit/hot-unplug + close. | |
1605 | */ | |
1606 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1607 | return; | |
1608 | ||
1609 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1610 | ||
1611 | /* | |
1612 | * If this is a sibling, remove it from its group. | |
1613 | */ | |
1614 | if (event->group_leader != event) { | |
1615 | list_del_init(&event->group_entry); | |
1616 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1617 | goto out; |
8a49542c PZ |
1618 | } |
1619 | ||
1620 | if (!list_empty(&event->group_entry)) | |
1621 | list = &event->group_entry; | |
2e2af50b | 1622 | |
04289bb9 | 1623 | /* |
cdd6c482 IM |
1624 | * If this was a group event with sibling events then |
1625 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1626 | * to whatever list we are on. |
04289bb9 | 1627 | */ |
cdd6c482 | 1628 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1629 | if (list) |
1630 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1631 | sibling->group_leader = sibling; |
d6f962b5 FW |
1632 | |
1633 | /* Inherit group flags from the previous leader */ | |
1634 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1635 | |
1636 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1637 | } |
c320c7b7 ACM |
1638 | |
1639 | out: | |
1640 | perf_event__header_size(event->group_leader); | |
1641 | ||
1642 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1643 | perf_event__header_size(tmp); | |
04289bb9 IM |
1644 | } |
1645 | ||
fadfe7be JO |
1646 | static bool is_orphaned_event(struct perf_event *event) |
1647 | { | |
c6e5b732 | 1648 | return event->state == PERF_EVENT_STATE_EXIT; |
fadfe7be JO |
1649 | } |
1650 | ||
66eb579e MR |
1651 | static inline int pmu_filter_match(struct perf_event *event) |
1652 | { | |
1653 | struct pmu *pmu = event->pmu; | |
1654 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1655 | } | |
1656 | ||
fa66f07a SE |
1657 | static inline int |
1658 | event_filter_match(struct perf_event *event) | |
1659 | { | |
e5d1367f | 1660 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1661 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1662 | } |
1663 | ||
9ffcfa6f SE |
1664 | static void |
1665 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1666 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1667 | struct perf_event_context *ctx) |
3b6f9e5c | 1668 | { |
4158755d | 1669 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1670 | u64 delta; |
652884fe PZ |
1671 | |
1672 | WARN_ON_ONCE(event->ctx != ctx); | |
1673 | lockdep_assert_held(&ctx->lock); | |
1674 | ||
fa66f07a SE |
1675 | /* |
1676 | * An event which could not be activated because of | |
1677 | * filter mismatch still needs to have its timings | |
1678 | * maintained, otherwise bogus information is return | |
1679 | * via read() for time_enabled, time_running: | |
1680 | */ | |
1681 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1682 | && !event_filter_match(event)) { | |
e5d1367f | 1683 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1684 | event->tstamp_running += delta; |
4158755d | 1685 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1686 | } |
1687 | ||
cdd6c482 | 1688 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1689 | return; |
3b6f9e5c | 1690 | |
44377277 AS |
1691 | perf_pmu_disable(event->pmu); |
1692 | ||
cdd6c482 IM |
1693 | event->state = PERF_EVENT_STATE_INACTIVE; |
1694 | if (event->pending_disable) { | |
1695 | event->pending_disable = 0; | |
1696 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1697 | } |
4158755d | 1698 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1699 | event->pmu->del(event, 0); |
cdd6c482 | 1700 | event->oncpu = -1; |
3b6f9e5c | 1701 | |
cdd6c482 | 1702 | if (!is_software_event(event)) |
3b6f9e5c | 1703 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1704 | if (!--ctx->nr_active) |
1705 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1706 | if (event->attr.freq && event->attr.sample_freq) |
1707 | ctx->nr_freq--; | |
cdd6c482 | 1708 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1709 | cpuctx->exclusive = 0; |
44377277 AS |
1710 | |
1711 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1712 | } |
1713 | ||
d859e29f | 1714 | static void |
cdd6c482 | 1715 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1716 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1717 | struct perf_event_context *ctx) |
d859e29f | 1718 | { |
cdd6c482 | 1719 | struct perf_event *event; |
fa66f07a | 1720 | int state = group_event->state; |
d859e29f | 1721 | |
cdd6c482 | 1722 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1723 | |
1724 | /* | |
1725 | * Schedule out siblings (if any): | |
1726 | */ | |
cdd6c482 IM |
1727 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1728 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1729 | |
fa66f07a | 1730 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1731 | cpuctx->exclusive = 0; |
1732 | } | |
1733 | ||
45a0e07a | 1734 | #define DETACH_GROUP 0x01UL |
60beda84 | 1735 | #define DETACH_STATE 0x02UL |
0017960f | 1736 | |
0793a61d | 1737 | /* |
cdd6c482 | 1738 | * Cross CPU call to remove a performance event |
0793a61d | 1739 | * |
cdd6c482 | 1740 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1741 | * remove it from the context list. |
1742 | */ | |
fae3fde6 PZ |
1743 | static void |
1744 | __perf_remove_from_context(struct perf_event *event, | |
1745 | struct perf_cpu_context *cpuctx, | |
1746 | struct perf_event_context *ctx, | |
1747 | void *info) | |
0793a61d | 1748 | { |
45a0e07a | 1749 | unsigned long flags = (unsigned long)info; |
0793a61d | 1750 | |
cdd6c482 | 1751 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1752 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1753 | perf_group_detach(event); |
cdd6c482 | 1754 | list_del_event(event, ctx); |
60beda84 PZ |
1755 | if (flags & DETACH_STATE) |
1756 | event->state = PERF_EVENT_STATE_EXIT; | |
39a43640 PZ |
1757 | |
1758 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1759 | ctx->is_active = 0; |
39a43640 PZ |
1760 | if (ctx->task) { |
1761 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1762 | cpuctx->task_ctx = NULL; | |
1763 | } | |
64ce3126 | 1764 | } |
0793a61d TG |
1765 | } |
1766 | ||
0793a61d | 1767 | /* |
cdd6c482 | 1768 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1769 | * |
cdd6c482 IM |
1770 | * If event->ctx is a cloned context, callers must make sure that |
1771 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1772 | * remains valid. This is OK when called from perf_release since |
1773 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1774 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1775 | * context has been detached from its task. |
0793a61d | 1776 | */ |
45a0e07a | 1777 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1778 | { |
fae3fde6 | 1779 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1780 | |
45a0e07a | 1781 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1782 | } |
1783 | ||
d859e29f | 1784 | /* |
cdd6c482 | 1785 | * Cross CPU call to disable a performance event |
d859e29f | 1786 | */ |
fae3fde6 PZ |
1787 | static void __perf_event_disable(struct perf_event *event, |
1788 | struct perf_cpu_context *cpuctx, | |
1789 | struct perf_event_context *ctx, | |
1790 | void *info) | |
7b648018 | 1791 | { |
fae3fde6 PZ |
1792 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1793 | return; | |
7b648018 | 1794 | |
fae3fde6 PZ |
1795 | update_context_time(ctx); |
1796 | update_cgrp_time_from_event(event); | |
1797 | update_group_times(event); | |
1798 | if (event == event->group_leader) | |
1799 | group_sched_out(event, cpuctx, ctx); | |
1800 | else | |
1801 | event_sched_out(event, cpuctx, ctx); | |
1802 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1803 | } |
1804 | ||
d859e29f | 1805 | /* |
cdd6c482 | 1806 | * Disable a event. |
c93f7669 | 1807 | * |
cdd6c482 IM |
1808 | * If event->ctx is a cloned context, callers must make sure that |
1809 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1810 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1811 | * perf_event_for_each_child or perf_event_for_each because they |
1812 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1813 | * goes to exit will block in perf_event_exit_event(). |
1814 | * | |
cdd6c482 | 1815 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1816 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1817 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1818 | */ |
f63a8daa | 1819 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1820 | { |
cdd6c482 | 1821 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1822 | |
e625cce1 | 1823 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1824 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1825 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1826 | return; |
53cfbf59 | 1827 | } |
e625cce1 | 1828 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1829 | |
fae3fde6 PZ |
1830 | event_function_call(event, __perf_event_disable, NULL); |
1831 | } | |
1832 | ||
1833 | void perf_event_disable_local(struct perf_event *event) | |
1834 | { | |
1835 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1836 | } |
f63a8daa PZ |
1837 | |
1838 | /* | |
1839 | * Strictly speaking kernel users cannot create groups and therefore this | |
1840 | * interface does not need the perf_event_ctx_lock() magic. | |
1841 | */ | |
1842 | void perf_event_disable(struct perf_event *event) | |
1843 | { | |
1844 | struct perf_event_context *ctx; | |
1845 | ||
1846 | ctx = perf_event_ctx_lock(event); | |
1847 | _perf_event_disable(event); | |
1848 | perf_event_ctx_unlock(event, ctx); | |
1849 | } | |
dcfce4a0 | 1850 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1851 | |
e5d1367f SE |
1852 | static void perf_set_shadow_time(struct perf_event *event, |
1853 | struct perf_event_context *ctx, | |
1854 | u64 tstamp) | |
1855 | { | |
1856 | /* | |
1857 | * use the correct time source for the time snapshot | |
1858 | * | |
1859 | * We could get by without this by leveraging the | |
1860 | * fact that to get to this function, the caller | |
1861 | * has most likely already called update_context_time() | |
1862 | * and update_cgrp_time_xx() and thus both timestamp | |
1863 | * are identical (or very close). Given that tstamp is, | |
1864 | * already adjusted for cgroup, we could say that: | |
1865 | * tstamp - ctx->timestamp | |
1866 | * is equivalent to | |
1867 | * tstamp - cgrp->timestamp. | |
1868 | * | |
1869 | * Then, in perf_output_read(), the calculation would | |
1870 | * work with no changes because: | |
1871 | * - event is guaranteed scheduled in | |
1872 | * - no scheduled out in between | |
1873 | * - thus the timestamp would be the same | |
1874 | * | |
1875 | * But this is a bit hairy. | |
1876 | * | |
1877 | * So instead, we have an explicit cgroup call to remain | |
1878 | * within the time time source all along. We believe it | |
1879 | * is cleaner and simpler to understand. | |
1880 | */ | |
1881 | if (is_cgroup_event(event)) | |
1882 | perf_cgroup_set_shadow_time(event, tstamp); | |
1883 | else | |
1884 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1885 | } | |
1886 | ||
4fe757dd PZ |
1887 | #define MAX_INTERRUPTS (~0ULL) |
1888 | ||
1889 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1890 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1891 | |
235c7fc7 | 1892 | static int |
9ffcfa6f | 1893 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1894 | struct perf_cpu_context *cpuctx, |
6e37738a | 1895 | struct perf_event_context *ctx) |
235c7fc7 | 1896 | { |
4158755d | 1897 | u64 tstamp = perf_event_time(event); |
44377277 | 1898 | int ret = 0; |
4158755d | 1899 | |
63342411 PZ |
1900 | lockdep_assert_held(&ctx->lock); |
1901 | ||
cdd6c482 | 1902 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1903 | return 0; |
1904 | ||
cdd6c482 | 1905 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1906 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1907 | |
1908 | /* | |
1909 | * Unthrottle events, since we scheduled we might have missed several | |
1910 | * ticks already, also for a heavily scheduling task there is little | |
1911 | * guarantee it'll get a tick in a timely manner. | |
1912 | */ | |
1913 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1914 | perf_log_throttle(event, 1); | |
1915 | event->hw.interrupts = 0; | |
1916 | } | |
1917 | ||
235c7fc7 IM |
1918 | /* |
1919 | * The new state must be visible before we turn it on in the hardware: | |
1920 | */ | |
1921 | smp_wmb(); | |
1922 | ||
44377277 AS |
1923 | perf_pmu_disable(event->pmu); |
1924 | ||
72f669c0 SL |
1925 | perf_set_shadow_time(event, ctx, tstamp); |
1926 | ||
ec0d7729 AS |
1927 | perf_log_itrace_start(event); |
1928 | ||
a4eaf7f1 | 1929 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1930 | event->state = PERF_EVENT_STATE_INACTIVE; |
1931 | event->oncpu = -1; | |
44377277 AS |
1932 | ret = -EAGAIN; |
1933 | goto out; | |
235c7fc7 IM |
1934 | } |
1935 | ||
00a2916f PZ |
1936 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1937 | ||
cdd6c482 | 1938 | if (!is_software_event(event)) |
3b6f9e5c | 1939 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1940 | if (!ctx->nr_active++) |
1941 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1942 | if (event->attr.freq && event->attr.sample_freq) |
1943 | ctx->nr_freq++; | |
235c7fc7 | 1944 | |
cdd6c482 | 1945 | if (event->attr.exclusive) |
3b6f9e5c PM |
1946 | cpuctx->exclusive = 1; |
1947 | ||
44377277 AS |
1948 | out: |
1949 | perf_pmu_enable(event->pmu); | |
1950 | ||
1951 | return ret; | |
235c7fc7 IM |
1952 | } |
1953 | ||
6751b71e | 1954 | static int |
cdd6c482 | 1955 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1956 | struct perf_cpu_context *cpuctx, |
6e37738a | 1957 | struct perf_event_context *ctx) |
6751b71e | 1958 | { |
6bde9b6c | 1959 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1960 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1961 | u64 now = ctx->time; |
1962 | bool simulate = false; | |
6751b71e | 1963 | |
cdd6c482 | 1964 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1965 | return 0; |
1966 | ||
fbbe0701 | 1967 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1968 | |
9ffcfa6f | 1969 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1970 | pmu->cancel_txn(pmu); |
272325c4 | 1971 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1972 | return -EAGAIN; |
90151c35 | 1973 | } |
6751b71e PM |
1974 | |
1975 | /* | |
1976 | * Schedule in siblings as one group (if any): | |
1977 | */ | |
cdd6c482 | 1978 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1979 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1980 | partial_group = event; |
6751b71e PM |
1981 | goto group_error; |
1982 | } | |
1983 | } | |
1984 | ||
9ffcfa6f | 1985 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1986 | return 0; |
9ffcfa6f | 1987 | |
6751b71e PM |
1988 | group_error: |
1989 | /* | |
1990 | * Groups can be scheduled in as one unit only, so undo any | |
1991 | * partial group before returning: | |
d7842da4 SE |
1992 | * The events up to the failed event are scheduled out normally, |
1993 | * tstamp_stopped will be updated. | |
1994 | * | |
1995 | * The failed events and the remaining siblings need to have | |
1996 | * their timings updated as if they had gone thru event_sched_in() | |
1997 | * and event_sched_out(). This is required to get consistent timings | |
1998 | * across the group. This also takes care of the case where the group | |
1999 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2000 | * the time the event was actually stopped, such that time delta | |
2001 | * calculation in update_event_times() is correct. | |
6751b71e | 2002 | */ |
cdd6c482 IM |
2003 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2004 | if (event == partial_group) | |
d7842da4 SE |
2005 | simulate = true; |
2006 | ||
2007 | if (simulate) { | |
2008 | event->tstamp_running += now - event->tstamp_stopped; | |
2009 | event->tstamp_stopped = now; | |
2010 | } else { | |
2011 | event_sched_out(event, cpuctx, ctx); | |
2012 | } | |
6751b71e | 2013 | } |
9ffcfa6f | 2014 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2015 | |
ad5133b7 | 2016 | pmu->cancel_txn(pmu); |
90151c35 | 2017 | |
272325c4 | 2018 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2019 | |
6751b71e PM |
2020 | return -EAGAIN; |
2021 | } | |
2022 | ||
3b6f9e5c | 2023 | /* |
cdd6c482 | 2024 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2025 | */ |
cdd6c482 | 2026 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2027 | struct perf_cpu_context *cpuctx, |
2028 | int can_add_hw) | |
2029 | { | |
2030 | /* | |
cdd6c482 | 2031 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2032 | */ |
d6f962b5 | 2033 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2034 | return 1; |
2035 | /* | |
2036 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2037 | * events can go on. |
3b6f9e5c PM |
2038 | */ |
2039 | if (cpuctx->exclusive) | |
2040 | return 0; | |
2041 | /* | |
2042 | * If this group is exclusive and there are already | |
cdd6c482 | 2043 | * events on the CPU, it can't go on. |
3b6f9e5c | 2044 | */ |
cdd6c482 | 2045 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2046 | return 0; |
2047 | /* | |
2048 | * Otherwise, try to add it if all previous groups were able | |
2049 | * to go on. | |
2050 | */ | |
2051 | return can_add_hw; | |
2052 | } | |
2053 | ||
cdd6c482 IM |
2054 | static void add_event_to_ctx(struct perf_event *event, |
2055 | struct perf_event_context *ctx) | |
53cfbf59 | 2056 | { |
4158755d SE |
2057 | u64 tstamp = perf_event_time(event); |
2058 | ||
cdd6c482 | 2059 | list_add_event(event, ctx); |
8a49542c | 2060 | perf_group_attach(event); |
4158755d SE |
2061 | event->tstamp_enabled = tstamp; |
2062 | event->tstamp_running = tstamp; | |
2063 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2064 | } |
2065 | ||
3e349507 PZ |
2066 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2067 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2068 | static void |
2069 | ctx_sched_in(struct perf_event_context *ctx, | |
2070 | struct perf_cpu_context *cpuctx, | |
2071 | enum event_type_t event_type, | |
2072 | struct task_struct *task); | |
fe4b04fa | 2073 | |
dce5855b PZ |
2074 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2075 | struct perf_event_context *ctx, | |
2076 | struct task_struct *task) | |
2077 | { | |
2078 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2079 | if (ctx) | |
2080 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2081 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2082 | if (ctx) | |
2083 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2084 | } | |
2085 | ||
3e349507 PZ |
2086 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2087 | struct perf_event_context *task_ctx) | |
0017960f | 2088 | { |
3e349507 PZ |
2089 | perf_pmu_disable(cpuctx->ctx.pmu); |
2090 | if (task_ctx) | |
2091 | task_ctx_sched_out(cpuctx, task_ctx); | |
2092 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2093 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2094 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2095 | } |
2096 | ||
0793a61d | 2097 | /* |
cdd6c482 | 2098 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2099 | * |
2100 | * Must be called with ctx->mutex held | |
0793a61d | 2101 | */ |
fe4b04fa | 2102 | static int __perf_install_in_context(void *info) |
0793a61d | 2103 | { |
39a43640 | 2104 | struct perf_event_context *ctx = info; |
108b02cf | 2105 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2106 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
0793a61d | 2107 | |
63b6da39 | 2108 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2109 | if (ctx->task) { |
b58f6b0d | 2110 | raw_spin_lock(&ctx->lock); |
39a43640 PZ |
2111 | /* |
2112 | * If we hit the 'wrong' task, we've since scheduled and | |
2113 | * everything should be sorted, nothing to do! | |
2114 | */ | |
b58f6b0d | 2115 | task_ctx = ctx; |
39a43640 | 2116 | if (ctx->task != current) |
63b6da39 | 2117 | goto unlock; |
b58f6b0d | 2118 | |
39a43640 PZ |
2119 | /* |
2120 | * If task_ctx is set, it had better be to us. | |
2121 | */ | |
2122 | WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx); | |
63b6da39 PZ |
2123 | } else if (task_ctx) { |
2124 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2125 | } |
b58f6b0d | 2126 | |
39a43640 | 2127 | ctx_resched(cpuctx, task_ctx); |
63b6da39 | 2128 | unlock: |
2c29ef0f | 2129 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2130 | |
2131 | return 0; | |
0793a61d TG |
2132 | } |
2133 | ||
2134 | /* | |
cdd6c482 | 2135 | * Attach a performance event to a context |
0793a61d TG |
2136 | */ |
2137 | static void | |
cdd6c482 IM |
2138 | perf_install_in_context(struct perf_event_context *ctx, |
2139 | struct perf_event *event, | |
0793a61d TG |
2140 | int cpu) |
2141 | { | |
39a43640 PZ |
2142 | struct task_struct *task = NULL; |
2143 | ||
fe4b04fa PZ |
2144 | lockdep_assert_held(&ctx->mutex); |
2145 | ||
c3f00c70 | 2146 | event->ctx = ctx; |
0cda4c02 YZ |
2147 | if (event->cpu != -1) |
2148 | event->cpu = cpu; | |
c3f00c70 | 2149 | |
39a43640 PZ |
2150 | /* |
2151 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2152 | * to be set in case this is the nr_events 0 -> 1 transition. | |
2153 | * | |
2154 | * So what we do is we add the event to the list here, which will allow | |
2155 | * a future context switch to DTRT and then send a racy IPI. If the IPI | |
2156 | * fails to hit the right task, this means a context switch must have | |
2157 | * happened and that will have taken care of business. | |
2158 | */ | |
2159 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
2160 | task = ctx->task; |
2161 | /* | |
2162 | * Worse, we cannot even rely on the ctx actually existing anymore. If | |
2163 | * between find_get_context() and perf_install_in_context() the task | |
2164 | * went through perf_event_exit_task() its dead and we should not be | |
2165 | * adding new events. | |
2166 | */ | |
2167 | if (task == TASK_TOMBSTONE) { | |
2168 | raw_spin_unlock_irq(&ctx->lock); | |
2169 | return; | |
2170 | } | |
39a43640 PZ |
2171 | update_context_time(ctx); |
2172 | /* | |
2173 | * Update cgrp time only if current cgrp matches event->cgrp. | |
2174 | * Must be done before calling add_event_to_ctx(). | |
2175 | */ | |
2176 | update_cgrp_time_from_event(event); | |
2177 | add_event_to_ctx(event, ctx); | |
39a43640 PZ |
2178 | raw_spin_unlock_irq(&ctx->lock); |
2179 | ||
2180 | if (task) | |
2181 | task_function_call(task, __perf_install_in_context, ctx); | |
2182 | else | |
2183 | cpu_function_call(cpu, __perf_install_in_context, ctx); | |
0793a61d TG |
2184 | } |
2185 | ||
fa289bec | 2186 | /* |
cdd6c482 | 2187 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2188 | * Enabling the leader of a group effectively enables all |
2189 | * the group members that aren't explicitly disabled, so we | |
2190 | * have to update their ->tstamp_enabled also. | |
2191 | * Note: this works for group members as well as group leaders | |
2192 | * since the non-leader members' sibling_lists will be empty. | |
2193 | */ | |
1d9b482e | 2194 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2195 | { |
cdd6c482 | 2196 | struct perf_event *sub; |
4158755d | 2197 | u64 tstamp = perf_event_time(event); |
fa289bec | 2198 | |
cdd6c482 | 2199 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2200 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2201 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2202 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2203 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2204 | } |
fa289bec PM |
2205 | } |
2206 | ||
d859e29f | 2207 | /* |
cdd6c482 | 2208 | * Cross CPU call to enable a performance event |
d859e29f | 2209 | */ |
fae3fde6 PZ |
2210 | static void __perf_event_enable(struct perf_event *event, |
2211 | struct perf_cpu_context *cpuctx, | |
2212 | struct perf_event_context *ctx, | |
2213 | void *info) | |
04289bb9 | 2214 | { |
cdd6c482 | 2215 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2216 | struct perf_event_context *task_ctx; |
04289bb9 | 2217 | |
6e801e01 PZ |
2218 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2219 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2220 | return; |
3cbed429 | 2221 | |
4af4998b | 2222 | update_context_time(ctx); |
1d9b482e | 2223 | __perf_event_mark_enabled(event); |
04289bb9 | 2224 | |
fae3fde6 PZ |
2225 | if (!ctx->is_active) |
2226 | return; | |
2227 | ||
e5d1367f | 2228 | if (!event_filter_match(event)) { |
fae3fde6 PZ |
2229 | if (is_cgroup_event(event)) { |
2230 | perf_cgroup_set_timestamp(current, ctx); // XXX ? | |
e5d1367f | 2231 | perf_cgroup_defer_enabled(event); |
fae3fde6 PZ |
2232 | } |
2233 | return; | |
e5d1367f | 2234 | } |
f4c4176f | 2235 | |
04289bb9 | 2236 | /* |
cdd6c482 | 2237 | * If the event is in a group and isn't the group leader, |
d859e29f | 2238 | * then don't put it on unless the group is on. |
04289bb9 | 2239 | */ |
cdd6c482 | 2240 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
fae3fde6 | 2241 | return; |
fe4b04fa | 2242 | |
fae3fde6 PZ |
2243 | task_ctx = cpuctx->task_ctx; |
2244 | if (ctx->task) | |
2245 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2246 | |
fae3fde6 | 2247 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2248 | } |
2249 | ||
d859e29f | 2250 | /* |
cdd6c482 | 2251 | * Enable a event. |
c93f7669 | 2252 | * |
cdd6c482 IM |
2253 | * If event->ctx is a cloned context, callers must make sure that |
2254 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2255 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2256 | * perf_event_for_each_child or perf_event_for_each as described |
2257 | * for perf_event_disable. | |
d859e29f | 2258 | */ |
f63a8daa | 2259 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2260 | { |
cdd6c482 | 2261 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2262 | |
7b648018 | 2263 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2264 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2265 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2266 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2267 | return; |
2268 | } | |
2269 | ||
d859e29f | 2270 | /* |
cdd6c482 | 2271 | * If the event is in error state, clear that first. |
7b648018 PZ |
2272 | * |
2273 | * That way, if we see the event in error state below, we know that it | |
2274 | * has gone back into error state, as distinct from the task having | |
2275 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2276 | */ |
cdd6c482 IM |
2277 | if (event->state == PERF_EVENT_STATE_ERROR) |
2278 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2279 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2280 | |
fae3fde6 | 2281 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2282 | } |
f63a8daa PZ |
2283 | |
2284 | /* | |
2285 | * See perf_event_disable(); | |
2286 | */ | |
2287 | void perf_event_enable(struct perf_event *event) | |
2288 | { | |
2289 | struct perf_event_context *ctx; | |
2290 | ||
2291 | ctx = perf_event_ctx_lock(event); | |
2292 | _perf_event_enable(event); | |
2293 | perf_event_ctx_unlock(event, ctx); | |
2294 | } | |
dcfce4a0 | 2295 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2296 | |
f63a8daa | 2297 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2298 | { |
2023b359 | 2299 | /* |
cdd6c482 | 2300 | * not supported on inherited events |
2023b359 | 2301 | */ |
2e939d1d | 2302 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2303 | return -EINVAL; |
2304 | ||
cdd6c482 | 2305 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2306 | _perf_event_enable(event); |
2023b359 PZ |
2307 | |
2308 | return 0; | |
79f14641 | 2309 | } |
f63a8daa PZ |
2310 | |
2311 | /* | |
2312 | * See perf_event_disable() | |
2313 | */ | |
2314 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2315 | { | |
2316 | struct perf_event_context *ctx; | |
2317 | int ret; | |
2318 | ||
2319 | ctx = perf_event_ctx_lock(event); | |
2320 | ret = _perf_event_refresh(event, refresh); | |
2321 | perf_event_ctx_unlock(event, ctx); | |
2322 | ||
2323 | return ret; | |
2324 | } | |
26ca5c11 | 2325 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2326 | |
5b0311e1 FW |
2327 | static void ctx_sched_out(struct perf_event_context *ctx, |
2328 | struct perf_cpu_context *cpuctx, | |
2329 | enum event_type_t event_type) | |
235c7fc7 | 2330 | { |
db24d33e | 2331 | int is_active = ctx->is_active; |
c994d613 | 2332 | struct perf_event *event; |
235c7fc7 | 2333 | |
c994d613 | 2334 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2335 | |
39a43640 PZ |
2336 | if (likely(!ctx->nr_events)) { |
2337 | /* | |
2338 | * See __perf_remove_from_context(). | |
2339 | */ | |
2340 | WARN_ON_ONCE(ctx->is_active); | |
2341 | if (ctx->task) | |
2342 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2343 | return; |
39a43640 PZ |
2344 | } |
2345 | ||
db24d33e | 2346 | ctx->is_active &= ~event_type; |
63e30d3e PZ |
2347 | if (ctx->task) { |
2348 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2349 | if (!ctx->is_active) | |
2350 | cpuctx->task_ctx = NULL; | |
2351 | } | |
facc4307 | 2352 | |
4af4998b | 2353 | update_context_time(ctx); |
e5d1367f | 2354 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2355 | if (!ctx->nr_active) |
facc4307 | 2356 | return; |
5b0311e1 | 2357 | |
075e0b00 | 2358 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2359 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2360 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2361 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2362 | } |
889ff015 | 2363 | |
db24d33e | 2364 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2365 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2366 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2367 | } |
1b9a644f | 2368 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2369 | } |
2370 | ||
564c2b21 | 2371 | /* |
5a3126d4 PZ |
2372 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2373 | * cloned from the same version of the same context. | |
2374 | * | |
2375 | * Equivalence is measured using a generation number in the context that is | |
2376 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2377 | * and list_del_event(). | |
564c2b21 | 2378 | */ |
cdd6c482 IM |
2379 | static int context_equiv(struct perf_event_context *ctx1, |
2380 | struct perf_event_context *ctx2) | |
564c2b21 | 2381 | { |
211de6eb PZ |
2382 | lockdep_assert_held(&ctx1->lock); |
2383 | lockdep_assert_held(&ctx2->lock); | |
2384 | ||
5a3126d4 PZ |
2385 | /* Pinning disables the swap optimization */ |
2386 | if (ctx1->pin_count || ctx2->pin_count) | |
2387 | return 0; | |
2388 | ||
2389 | /* If ctx1 is the parent of ctx2 */ | |
2390 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2391 | return 1; | |
2392 | ||
2393 | /* If ctx2 is the parent of ctx1 */ | |
2394 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2395 | return 1; | |
2396 | ||
2397 | /* | |
2398 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2399 | * hierarchy, see perf_event_init_context(). | |
2400 | */ | |
2401 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2402 | ctx1->parent_gen == ctx2->parent_gen) | |
2403 | return 1; | |
2404 | ||
2405 | /* Unmatched */ | |
2406 | return 0; | |
564c2b21 PM |
2407 | } |
2408 | ||
cdd6c482 IM |
2409 | static void __perf_event_sync_stat(struct perf_event *event, |
2410 | struct perf_event *next_event) | |
bfbd3381 PZ |
2411 | { |
2412 | u64 value; | |
2413 | ||
cdd6c482 | 2414 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2415 | return; |
2416 | ||
2417 | /* | |
cdd6c482 | 2418 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2419 | * because we're in the middle of a context switch and have IRQs |
2420 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2421 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2422 | * don't need to use it. |
2423 | */ | |
cdd6c482 IM |
2424 | switch (event->state) { |
2425 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2426 | event->pmu->read(event); |
2427 | /* fall-through */ | |
bfbd3381 | 2428 | |
cdd6c482 IM |
2429 | case PERF_EVENT_STATE_INACTIVE: |
2430 | update_event_times(event); | |
bfbd3381 PZ |
2431 | break; |
2432 | ||
2433 | default: | |
2434 | break; | |
2435 | } | |
2436 | ||
2437 | /* | |
cdd6c482 | 2438 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2439 | * values when we flip the contexts. |
2440 | */ | |
e7850595 PZ |
2441 | value = local64_read(&next_event->count); |
2442 | value = local64_xchg(&event->count, value); | |
2443 | local64_set(&next_event->count, value); | |
bfbd3381 | 2444 | |
cdd6c482 IM |
2445 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2446 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2447 | |
bfbd3381 | 2448 | /* |
19d2e755 | 2449 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2450 | */ |
cdd6c482 IM |
2451 | perf_event_update_userpage(event); |
2452 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2453 | } |
2454 | ||
cdd6c482 IM |
2455 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2456 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2457 | { |
cdd6c482 | 2458 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2459 | |
2460 | if (!ctx->nr_stat) | |
2461 | return; | |
2462 | ||
02ffdbc8 PZ |
2463 | update_context_time(ctx); |
2464 | ||
cdd6c482 IM |
2465 | event = list_first_entry(&ctx->event_list, |
2466 | struct perf_event, event_entry); | |
bfbd3381 | 2467 | |
cdd6c482 IM |
2468 | next_event = list_first_entry(&next_ctx->event_list, |
2469 | struct perf_event, event_entry); | |
bfbd3381 | 2470 | |
cdd6c482 IM |
2471 | while (&event->event_entry != &ctx->event_list && |
2472 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2473 | |
cdd6c482 | 2474 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2475 | |
cdd6c482 IM |
2476 | event = list_next_entry(event, event_entry); |
2477 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2478 | } |
2479 | } | |
2480 | ||
fe4b04fa PZ |
2481 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2482 | struct task_struct *next) | |
0793a61d | 2483 | { |
8dc85d54 | 2484 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2485 | struct perf_event_context *next_ctx; |
5a3126d4 | 2486 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2487 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2488 | int do_switch = 1; |
0793a61d | 2489 | |
108b02cf PZ |
2490 | if (likely(!ctx)) |
2491 | return; | |
10989fb2 | 2492 | |
108b02cf PZ |
2493 | cpuctx = __get_cpu_context(ctx); |
2494 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2495 | return; |
2496 | ||
c93f7669 | 2497 | rcu_read_lock(); |
8dc85d54 | 2498 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2499 | if (!next_ctx) |
2500 | goto unlock; | |
2501 | ||
2502 | parent = rcu_dereference(ctx->parent_ctx); | |
2503 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2504 | ||
2505 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2506 | if (!parent && !next_parent) |
5a3126d4 PZ |
2507 | goto unlock; |
2508 | ||
2509 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2510 | /* |
2511 | * Looks like the two contexts are clones, so we might be | |
2512 | * able to optimize the context switch. We lock both | |
2513 | * contexts and check that they are clones under the | |
2514 | * lock (including re-checking that neither has been | |
2515 | * uncloned in the meantime). It doesn't matter which | |
2516 | * order we take the locks because no other cpu could | |
2517 | * be trying to lock both of these tasks. | |
2518 | */ | |
e625cce1 TG |
2519 | raw_spin_lock(&ctx->lock); |
2520 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2521 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2522 | WRITE_ONCE(ctx->task, next); |
2523 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2524 | |
2525 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2526 | ||
63b6da39 PZ |
2527 | /* |
2528 | * RCU_INIT_POINTER here is safe because we've not | |
2529 | * modified the ctx and the above modification of | |
2530 | * ctx->task and ctx->task_ctx_data are immaterial | |
2531 | * since those values are always verified under | |
2532 | * ctx->lock which we're now holding. | |
2533 | */ | |
2534 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2535 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2536 | ||
c93f7669 | 2537 | do_switch = 0; |
bfbd3381 | 2538 | |
cdd6c482 | 2539 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2540 | } |
e625cce1 TG |
2541 | raw_spin_unlock(&next_ctx->lock); |
2542 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2543 | } |
5a3126d4 | 2544 | unlock: |
c93f7669 | 2545 | rcu_read_unlock(); |
564c2b21 | 2546 | |
c93f7669 | 2547 | if (do_switch) { |
facc4307 | 2548 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2549 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2550 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2551 | } |
0793a61d TG |
2552 | } |
2553 | ||
ba532500 YZ |
2554 | void perf_sched_cb_dec(struct pmu *pmu) |
2555 | { | |
2556 | this_cpu_dec(perf_sched_cb_usages); | |
2557 | } | |
2558 | ||
2559 | void perf_sched_cb_inc(struct pmu *pmu) | |
2560 | { | |
2561 | this_cpu_inc(perf_sched_cb_usages); | |
2562 | } | |
2563 | ||
2564 | /* | |
2565 | * This function provides the context switch callback to the lower code | |
2566 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2567 | */ | |
2568 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2569 | struct task_struct *next, | |
2570 | bool sched_in) | |
2571 | { | |
2572 | struct perf_cpu_context *cpuctx; | |
2573 | struct pmu *pmu; | |
2574 | unsigned long flags; | |
2575 | ||
2576 | if (prev == next) | |
2577 | return; | |
2578 | ||
2579 | local_irq_save(flags); | |
2580 | ||
2581 | rcu_read_lock(); | |
2582 | ||
2583 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2584 | if (pmu->sched_task) { | |
2585 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2586 | ||
2587 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2588 | ||
2589 | perf_pmu_disable(pmu); | |
2590 | ||
2591 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2592 | ||
2593 | perf_pmu_enable(pmu); | |
2594 | ||
2595 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2596 | } | |
2597 | } | |
2598 | ||
2599 | rcu_read_unlock(); | |
2600 | ||
2601 | local_irq_restore(flags); | |
2602 | } | |
2603 | ||
45ac1403 AH |
2604 | static void perf_event_switch(struct task_struct *task, |
2605 | struct task_struct *next_prev, bool sched_in); | |
2606 | ||
8dc85d54 PZ |
2607 | #define for_each_task_context_nr(ctxn) \ |
2608 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2609 | ||
2610 | /* | |
2611 | * Called from scheduler to remove the events of the current task, | |
2612 | * with interrupts disabled. | |
2613 | * | |
2614 | * We stop each event and update the event value in event->count. | |
2615 | * | |
2616 | * This does not protect us against NMI, but disable() | |
2617 | * sets the disabled bit in the control field of event _before_ | |
2618 | * accessing the event control register. If a NMI hits, then it will | |
2619 | * not restart the event. | |
2620 | */ | |
ab0cce56 JO |
2621 | void __perf_event_task_sched_out(struct task_struct *task, |
2622 | struct task_struct *next) | |
8dc85d54 PZ |
2623 | { |
2624 | int ctxn; | |
2625 | ||
ba532500 YZ |
2626 | if (__this_cpu_read(perf_sched_cb_usages)) |
2627 | perf_pmu_sched_task(task, next, false); | |
2628 | ||
45ac1403 AH |
2629 | if (atomic_read(&nr_switch_events)) |
2630 | perf_event_switch(task, next, false); | |
2631 | ||
8dc85d54 PZ |
2632 | for_each_task_context_nr(ctxn) |
2633 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2634 | |
2635 | /* | |
2636 | * if cgroup events exist on this CPU, then we need | |
2637 | * to check if we have to switch out PMU state. | |
2638 | * cgroup event are system-wide mode only | |
2639 | */ | |
4a32fea9 | 2640 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2641 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2642 | } |
2643 | ||
3e349507 PZ |
2644 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2645 | struct perf_event_context *ctx) | |
a08b159f | 2646 | { |
a63eaf34 PM |
2647 | if (!cpuctx->task_ctx) |
2648 | return; | |
012b84da IM |
2649 | |
2650 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2651 | return; | |
2652 | ||
04dc2dbb | 2653 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2654 | } |
2655 | ||
5b0311e1 FW |
2656 | /* |
2657 | * Called with IRQs disabled | |
2658 | */ | |
2659 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2660 | enum event_type_t event_type) | |
2661 | { | |
2662 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2663 | } |
2664 | ||
235c7fc7 | 2665 | static void |
5b0311e1 | 2666 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2667 | struct perf_cpu_context *cpuctx) |
0793a61d | 2668 | { |
cdd6c482 | 2669 | struct perf_event *event; |
0793a61d | 2670 | |
889ff015 FW |
2671 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2672 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2673 | continue; |
5632ab12 | 2674 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2675 | continue; |
2676 | ||
e5d1367f SE |
2677 | /* may need to reset tstamp_enabled */ |
2678 | if (is_cgroup_event(event)) | |
2679 | perf_cgroup_mark_enabled(event, ctx); | |
2680 | ||
8c9ed8e1 | 2681 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2682 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2683 | |
2684 | /* | |
2685 | * If this pinned group hasn't been scheduled, | |
2686 | * put it in error state. | |
2687 | */ | |
cdd6c482 IM |
2688 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2689 | update_group_times(event); | |
2690 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2691 | } |
3b6f9e5c | 2692 | } |
5b0311e1 FW |
2693 | } |
2694 | ||
2695 | static void | |
2696 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2697 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2698 | { |
2699 | struct perf_event *event; | |
2700 | int can_add_hw = 1; | |
3b6f9e5c | 2701 | |
889ff015 FW |
2702 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2703 | /* Ignore events in OFF or ERROR state */ | |
2704 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2705 | continue; |
04289bb9 IM |
2706 | /* |
2707 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2708 | * of events: |
04289bb9 | 2709 | */ |
5632ab12 | 2710 | if (!event_filter_match(event)) |
0793a61d TG |
2711 | continue; |
2712 | ||
e5d1367f SE |
2713 | /* may need to reset tstamp_enabled */ |
2714 | if (is_cgroup_event(event)) | |
2715 | perf_cgroup_mark_enabled(event, ctx); | |
2716 | ||
9ed6060d | 2717 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2718 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2719 | can_add_hw = 0; |
9ed6060d | 2720 | } |
0793a61d | 2721 | } |
5b0311e1 FW |
2722 | } |
2723 | ||
2724 | static void | |
2725 | ctx_sched_in(struct perf_event_context *ctx, | |
2726 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2727 | enum event_type_t event_type, |
2728 | struct task_struct *task) | |
5b0311e1 | 2729 | { |
db24d33e | 2730 | int is_active = ctx->is_active; |
c994d613 PZ |
2731 | u64 now; |
2732 | ||
2733 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2734 | |
5b0311e1 | 2735 | if (likely(!ctx->nr_events)) |
facc4307 | 2736 | return; |
5b0311e1 | 2737 | |
db24d33e | 2738 | ctx->is_active |= event_type; |
63e30d3e PZ |
2739 | if (ctx->task) { |
2740 | if (!is_active) | |
2741 | cpuctx->task_ctx = ctx; | |
2742 | else | |
2743 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2744 | } | |
2745 | ||
e5d1367f SE |
2746 | now = perf_clock(); |
2747 | ctx->timestamp = now; | |
3f7cce3c | 2748 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2749 | /* |
2750 | * First go through the list and put on any pinned groups | |
2751 | * in order to give them the best chance of going on. | |
2752 | */ | |
db24d33e | 2753 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2754 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2755 | |
2756 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2757 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2758 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2759 | } |
2760 | ||
329c0e01 | 2761 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2762 | enum event_type_t event_type, |
2763 | struct task_struct *task) | |
329c0e01 FW |
2764 | { |
2765 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2766 | ||
e5d1367f | 2767 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2768 | } |
2769 | ||
e5d1367f SE |
2770 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2771 | struct task_struct *task) | |
235c7fc7 | 2772 | { |
108b02cf | 2773 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2774 | |
108b02cf | 2775 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2776 | if (cpuctx->task_ctx == ctx) |
2777 | return; | |
2778 | ||
facc4307 | 2779 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2780 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2781 | /* |
2782 | * We want to keep the following priority order: | |
2783 | * cpu pinned (that don't need to move), task pinned, | |
2784 | * cpu flexible, task flexible. | |
2785 | */ | |
2786 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2787 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2788 | perf_pmu_enable(ctx->pmu); |
2789 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2790 | } |
2791 | ||
8dc85d54 PZ |
2792 | /* |
2793 | * Called from scheduler to add the events of the current task | |
2794 | * with interrupts disabled. | |
2795 | * | |
2796 | * We restore the event value and then enable it. | |
2797 | * | |
2798 | * This does not protect us against NMI, but enable() | |
2799 | * sets the enabled bit in the control field of event _before_ | |
2800 | * accessing the event control register. If a NMI hits, then it will | |
2801 | * keep the event running. | |
2802 | */ | |
ab0cce56 JO |
2803 | void __perf_event_task_sched_in(struct task_struct *prev, |
2804 | struct task_struct *task) | |
8dc85d54 PZ |
2805 | { |
2806 | struct perf_event_context *ctx; | |
2807 | int ctxn; | |
2808 | ||
7e41d177 PZ |
2809 | /* |
2810 | * If cgroup events exist on this CPU, then we need to check if we have | |
2811 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2812 | * | |
2813 | * Since cgroup events are CPU events, we must schedule these in before | |
2814 | * we schedule in the task events. | |
2815 | */ | |
2816 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2817 | perf_cgroup_sched_in(prev, task); | |
2818 | ||
8dc85d54 PZ |
2819 | for_each_task_context_nr(ctxn) { |
2820 | ctx = task->perf_event_ctxp[ctxn]; | |
2821 | if (likely(!ctx)) | |
2822 | continue; | |
2823 | ||
e5d1367f | 2824 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2825 | } |
d010b332 | 2826 | |
45ac1403 AH |
2827 | if (atomic_read(&nr_switch_events)) |
2828 | perf_event_switch(task, prev, true); | |
2829 | ||
ba532500 YZ |
2830 | if (__this_cpu_read(perf_sched_cb_usages)) |
2831 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2832 | } |
2833 | ||
abd50713 PZ |
2834 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2835 | { | |
2836 | u64 frequency = event->attr.sample_freq; | |
2837 | u64 sec = NSEC_PER_SEC; | |
2838 | u64 divisor, dividend; | |
2839 | ||
2840 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2841 | ||
2842 | count_fls = fls64(count); | |
2843 | nsec_fls = fls64(nsec); | |
2844 | frequency_fls = fls64(frequency); | |
2845 | sec_fls = 30; | |
2846 | ||
2847 | /* | |
2848 | * We got @count in @nsec, with a target of sample_freq HZ | |
2849 | * the target period becomes: | |
2850 | * | |
2851 | * @count * 10^9 | |
2852 | * period = ------------------- | |
2853 | * @nsec * sample_freq | |
2854 | * | |
2855 | */ | |
2856 | ||
2857 | /* | |
2858 | * Reduce accuracy by one bit such that @a and @b converge | |
2859 | * to a similar magnitude. | |
2860 | */ | |
fe4b04fa | 2861 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2862 | do { \ |
2863 | if (a##_fls > b##_fls) { \ | |
2864 | a >>= 1; \ | |
2865 | a##_fls--; \ | |
2866 | } else { \ | |
2867 | b >>= 1; \ | |
2868 | b##_fls--; \ | |
2869 | } \ | |
2870 | } while (0) | |
2871 | ||
2872 | /* | |
2873 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2874 | * the other, so that finally we can do a u64/u64 division. | |
2875 | */ | |
2876 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2877 | REDUCE_FLS(nsec, frequency); | |
2878 | REDUCE_FLS(sec, count); | |
2879 | } | |
2880 | ||
2881 | if (count_fls + sec_fls > 64) { | |
2882 | divisor = nsec * frequency; | |
2883 | ||
2884 | while (count_fls + sec_fls > 64) { | |
2885 | REDUCE_FLS(count, sec); | |
2886 | divisor >>= 1; | |
2887 | } | |
2888 | ||
2889 | dividend = count * sec; | |
2890 | } else { | |
2891 | dividend = count * sec; | |
2892 | ||
2893 | while (nsec_fls + frequency_fls > 64) { | |
2894 | REDUCE_FLS(nsec, frequency); | |
2895 | dividend >>= 1; | |
2896 | } | |
2897 | ||
2898 | divisor = nsec * frequency; | |
2899 | } | |
2900 | ||
f6ab91ad PZ |
2901 | if (!divisor) |
2902 | return dividend; | |
2903 | ||
abd50713 PZ |
2904 | return div64_u64(dividend, divisor); |
2905 | } | |
2906 | ||
e050e3f0 SE |
2907 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2908 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2909 | ||
f39d47ff | 2910 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2911 | { |
cdd6c482 | 2912 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2913 | s64 period, sample_period; |
bd2b5b12 PZ |
2914 | s64 delta; |
2915 | ||
abd50713 | 2916 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2917 | |
2918 | delta = (s64)(period - hwc->sample_period); | |
2919 | delta = (delta + 7) / 8; /* low pass filter */ | |
2920 | ||
2921 | sample_period = hwc->sample_period + delta; | |
2922 | ||
2923 | if (!sample_period) | |
2924 | sample_period = 1; | |
2925 | ||
bd2b5b12 | 2926 | hwc->sample_period = sample_period; |
abd50713 | 2927 | |
e7850595 | 2928 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2929 | if (disable) |
2930 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2931 | ||
e7850595 | 2932 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2933 | |
2934 | if (disable) | |
2935 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2936 | } |
bd2b5b12 PZ |
2937 | } |
2938 | ||
e050e3f0 SE |
2939 | /* |
2940 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2941 | * events. At the same time, make sure, having freq events does not change | |
2942 | * the rate of unthrottling as that would introduce bias. | |
2943 | */ | |
2944 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2945 | int needs_unthr) | |
60db5e09 | 2946 | { |
cdd6c482 IM |
2947 | struct perf_event *event; |
2948 | struct hw_perf_event *hwc; | |
e050e3f0 | 2949 | u64 now, period = TICK_NSEC; |
abd50713 | 2950 | s64 delta; |
60db5e09 | 2951 | |
e050e3f0 SE |
2952 | /* |
2953 | * only need to iterate over all events iff: | |
2954 | * - context have events in frequency mode (needs freq adjust) | |
2955 | * - there are events to unthrottle on this cpu | |
2956 | */ | |
2957 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2958 | return; |
2959 | ||
e050e3f0 | 2960 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2961 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2962 | |
03541f8b | 2963 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2964 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2965 | continue; |
2966 | ||
5632ab12 | 2967 | if (!event_filter_match(event)) |
5d27c23d PZ |
2968 | continue; |
2969 | ||
44377277 AS |
2970 | perf_pmu_disable(event->pmu); |
2971 | ||
cdd6c482 | 2972 | hwc = &event->hw; |
6a24ed6c | 2973 | |
ae23bff1 | 2974 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2975 | hwc->interrupts = 0; |
cdd6c482 | 2976 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2977 | event->pmu->start(event, 0); |
a78ac325 PZ |
2978 | } |
2979 | ||
cdd6c482 | 2980 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2981 | goto next; |
60db5e09 | 2982 | |
e050e3f0 SE |
2983 | /* |
2984 | * stop the event and update event->count | |
2985 | */ | |
2986 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2987 | ||
e7850595 | 2988 | now = local64_read(&event->count); |
abd50713 PZ |
2989 | delta = now - hwc->freq_count_stamp; |
2990 | hwc->freq_count_stamp = now; | |
60db5e09 | 2991 | |
e050e3f0 SE |
2992 | /* |
2993 | * restart the event | |
2994 | * reload only if value has changed | |
f39d47ff SE |
2995 | * we have stopped the event so tell that |
2996 | * to perf_adjust_period() to avoid stopping it | |
2997 | * twice. | |
e050e3f0 | 2998 | */ |
abd50713 | 2999 | if (delta > 0) |
f39d47ff | 3000 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3001 | |
3002 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3003 | next: |
3004 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3005 | } |
e050e3f0 | 3006 | |
f39d47ff | 3007 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3008 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3009 | } |
3010 | ||
235c7fc7 | 3011 | /* |
cdd6c482 | 3012 | * Round-robin a context's events: |
235c7fc7 | 3013 | */ |
cdd6c482 | 3014 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3015 | { |
dddd3379 TG |
3016 | /* |
3017 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3018 | * disabled by the inheritance code. | |
3019 | */ | |
3020 | if (!ctx->rotate_disable) | |
3021 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3022 | } |
3023 | ||
9e630205 | 3024 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3025 | { |
8dc85d54 | 3026 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3027 | int rotate = 0; |
7fc23a53 | 3028 | |
b5ab4cd5 | 3029 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3030 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3031 | rotate = 1; | |
3032 | } | |
235c7fc7 | 3033 | |
8dc85d54 | 3034 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3035 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3036 | if (ctx->nr_events != ctx->nr_active) |
3037 | rotate = 1; | |
3038 | } | |
9717e6cd | 3039 | |
e050e3f0 | 3040 | if (!rotate) |
0f5a2601 PZ |
3041 | goto done; |
3042 | ||
facc4307 | 3043 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3044 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3045 | |
e050e3f0 SE |
3046 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3047 | if (ctx) | |
3048 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3049 | |
e050e3f0 SE |
3050 | rotate_ctx(&cpuctx->ctx); |
3051 | if (ctx) | |
3052 | rotate_ctx(ctx); | |
235c7fc7 | 3053 | |
e050e3f0 | 3054 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3055 | |
0f5a2601 PZ |
3056 | perf_pmu_enable(cpuctx->ctx.pmu); |
3057 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3058 | done: |
9e630205 SE |
3059 | |
3060 | return rotate; | |
e9d2b064 PZ |
3061 | } |
3062 | ||
026249ef FW |
3063 | #ifdef CONFIG_NO_HZ_FULL |
3064 | bool perf_event_can_stop_tick(void) | |
3065 | { | |
948b26b6 | 3066 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3067 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3068 | return false; |
d84153d6 FW |
3069 | else |
3070 | return true; | |
026249ef FW |
3071 | } |
3072 | #endif | |
3073 | ||
e9d2b064 PZ |
3074 | void perf_event_task_tick(void) |
3075 | { | |
2fde4f94 MR |
3076 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3077 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3078 | int throttled; |
b5ab4cd5 | 3079 | |
e9d2b064 PZ |
3080 | WARN_ON(!irqs_disabled()); |
3081 | ||
e050e3f0 SE |
3082 | __this_cpu_inc(perf_throttled_seq); |
3083 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3084 | ||
2fde4f94 | 3085 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3086 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3087 | } |
3088 | ||
889ff015 FW |
3089 | static int event_enable_on_exec(struct perf_event *event, |
3090 | struct perf_event_context *ctx) | |
3091 | { | |
3092 | if (!event->attr.enable_on_exec) | |
3093 | return 0; | |
3094 | ||
3095 | event->attr.enable_on_exec = 0; | |
3096 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3097 | return 0; | |
3098 | ||
1d9b482e | 3099 | __perf_event_mark_enabled(event); |
889ff015 FW |
3100 | |
3101 | return 1; | |
3102 | } | |
3103 | ||
57e7986e | 3104 | /* |
cdd6c482 | 3105 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3106 | * This expects task == current. |
3107 | */ | |
c1274499 | 3108 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3109 | { |
c1274499 | 3110 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3111 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3112 | struct perf_event *event; |
57e7986e PM |
3113 | unsigned long flags; |
3114 | int enabled = 0; | |
3115 | ||
3116 | local_irq_save(flags); | |
c1274499 | 3117 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3118 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3119 | goto out; |
3120 | ||
3e349507 PZ |
3121 | cpuctx = __get_cpu_context(ctx); |
3122 | perf_ctx_lock(cpuctx, ctx); | |
3123 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3124 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3125 | |
3126 | /* | |
3e349507 | 3127 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3128 | */ |
3e349507 | 3129 | if (enabled) { |
211de6eb | 3130 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3131 | ctx_resched(cpuctx, ctx); |
3132 | } | |
3133 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3134 | |
9ed6060d | 3135 | out: |
57e7986e | 3136 | local_irq_restore(flags); |
211de6eb PZ |
3137 | |
3138 | if (clone_ctx) | |
3139 | put_ctx(clone_ctx); | |
57e7986e PM |
3140 | } |
3141 | ||
e041e328 PZ |
3142 | void perf_event_exec(void) |
3143 | { | |
e041e328 PZ |
3144 | int ctxn; |
3145 | ||
3146 | rcu_read_lock(); | |
c1274499 PZ |
3147 | for_each_task_context_nr(ctxn) |
3148 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3149 | rcu_read_unlock(); |
3150 | } | |
3151 | ||
0492d4c5 PZ |
3152 | struct perf_read_data { |
3153 | struct perf_event *event; | |
3154 | bool group; | |
7d88962e | 3155 | int ret; |
0492d4c5 PZ |
3156 | }; |
3157 | ||
0793a61d | 3158 | /* |
cdd6c482 | 3159 | * Cross CPU call to read the hardware event |
0793a61d | 3160 | */ |
cdd6c482 | 3161 | static void __perf_event_read(void *info) |
0793a61d | 3162 | { |
0492d4c5 PZ |
3163 | struct perf_read_data *data = info; |
3164 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3165 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3166 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3167 | struct pmu *pmu = event->pmu; |
621a01ea | 3168 | |
e1ac3614 PM |
3169 | /* |
3170 | * If this is a task context, we need to check whether it is | |
3171 | * the current task context of this cpu. If not it has been | |
3172 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3173 | * event->count would have been updated to a recent sample |
3174 | * when the event was scheduled out. | |
e1ac3614 PM |
3175 | */ |
3176 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3177 | return; | |
3178 | ||
e625cce1 | 3179 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3180 | if (ctx->is_active) { |
542e72fc | 3181 | update_context_time(ctx); |
e5d1367f SE |
3182 | update_cgrp_time_from_event(event); |
3183 | } | |
0492d4c5 | 3184 | |
cdd6c482 | 3185 | update_event_times(event); |
4a00c16e SB |
3186 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3187 | goto unlock; | |
0492d4c5 | 3188 | |
4a00c16e SB |
3189 | if (!data->group) { |
3190 | pmu->read(event); | |
3191 | data->ret = 0; | |
0492d4c5 | 3192 | goto unlock; |
4a00c16e SB |
3193 | } |
3194 | ||
3195 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3196 | ||
3197 | pmu->read(event); | |
0492d4c5 PZ |
3198 | |
3199 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3200 | update_event_times(sub); | |
4a00c16e SB |
3201 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3202 | /* | |
3203 | * Use sibling's PMU rather than @event's since | |
3204 | * sibling could be on different (eg: software) PMU. | |
3205 | */ | |
0492d4c5 | 3206 | sub->pmu->read(sub); |
4a00c16e | 3207 | } |
0492d4c5 | 3208 | } |
4a00c16e SB |
3209 | |
3210 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3211 | |
3212 | unlock: | |
e625cce1 | 3213 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3214 | } |
3215 | ||
b5e58793 PZ |
3216 | static inline u64 perf_event_count(struct perf_event *event) |
3217 | { | |
eacd3ecc MF |
3218 | if (event->pmu->count) |
3219 | return event->pmu->count(event); | |
3220 | ||
3221 | return __perf_event_count(event); | |
b5e58793 PZ |
3222 | } |
3223 | ||
ffe8690c KX |
3224 | /* |
3225 | * NMI-safe method to read a local event, that is an event that | |
3226 | * is: | |
3227 | * - either for the current task, or for this CPU | |
3228 | * - does not have inherit set, for inherited task events | |
3229 | * will not be local and we cannot read them atomically | |
3230 | * - must not have a pmu::count method | |
3231 | */ | |
3232 | u64 perf_event_read_local(struct perf_event *event) | |
3233 | { | |
3234 | unsigned long flags; | |
3235 | u64 val; | |
3236 | ||
3237 | /* | |
3238 | * Disabling interrupts avoids all counter scheduling (context | |
3239 | * switches, timer based rotation and IPIs). | |
3240 | */ | |
3241 | local_irq_save(flags); | |
3242 | ||
3243 | /* If this is a per-task event, it must be for current */ | |
3244 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3245 | event->hw.target != current); | |
3246 | ||
3247 | /* If this is a per-CPU event, it must be for this CPU */ | |
3248 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3249 | event->cpu != smp_processor_id()); | |
3250 | ||
3251 | /* | |
3252 | * It must not be an event with inherit set, we cannot read | |
3253 | * all child counters from atomic context. | |
3254 | */ | |
3255 | WARN_ON_ONCE(event->attr.inherit); | |
3256 | ||
3257 | /* | |
3258 | * It must not have a pmu::count method, those are not | |
3259 | * NMI safe. | |
3260 | */ | |
3261 | WARN_ON_ONCE(event->pmu->count); | |
3262 | ||
3263 | /* | |
3264 | * If the event is currently on this CPU, its either a per-task event, | |
3265 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3266 | * oncpu == -1). | |
3267 | */ | |
3268 | if (event->oncpu == smp_processor_id()) | |
3269 | event->pmu->read(event); | |
3270 | ||
3271 | val = local64_read(&event->count); | |
3272 | local_irq_restore(flags); | |
3273 | ||
3274 | return val; | |
3275 | } | |
3276 | ||
7d88962e | 3277 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3278 | { |
7d88962e SB |
3279 | int ret = 0; |
3280 | ||
0793a61d | 3281 | /* |
cdd6c482 IM |
3282 | * If event is enabled and currently active on a CPU, update the |
3283 | * value in the event structure: | |
0793a61d | 3284 | */ |
cdd6c482 | 3285 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3286 | struct perf_read_data data = { |
3287 | .event = event, | |
3288 | .group = group, | |
7d88962e | 3289 | .ret = 0, |
0492d4c5 | 3290 | }; |
cdd6c482 | 3291 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3292 | __perf_event_read, &data, 1); |
7d88962e | 3293 | ret = data.ret; |
cdd6c482 | 3294 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3295 | struct perf_event_context *ctx = event->ctx; |
3296 | unsigned long flags; | |
3297 | ||
e625cce1 | 3298 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3299 | /* |
3300 | * may read while context is not active | |
3301 | * (e.g., thread is blocked), in that case | |
3302 | * we cannot update context time | |
3303 | */ | |
e5d1367f | 3304 | if (ctx->is_active) { |
c530ccd9 | 3305 | update_context_time(ctx); |
e5d1367f SE |
3306 | update_cgrp_time_from_event(event); |
3307 | } | |
0492d4c5 PZ |
3308 | if (group) |
3309 | update_group_times(event); | |
3310 | else | |
3311 | update_event_times(event); | |
e625cce1 | 3312 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3313 | } |
7d88962e SB |
3314 | |
3315 | return ret; | |
0793a61d TG |
3316 | } |
3317 | ||
a63eaf34 | 3318 | /* |
cdd6c482 | 3319 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3320 | */ |
eb184479 | 3321 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3322 | { |
e625cce1 | 3323 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3324 | mutex_init(&ctx->mutex); |
2fde4f94 | 3325 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3326 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3327 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3328 | INIT_LIST_HEAD(&ctx->event_list); |
3329 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3330 | } |
3331 | ||
3332 | static struct perf_event_context * | |
3333 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3334 | { | |
3335 | struct perf_event_context *ctx; | |
3336 | ||
3337 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3338 | if (!ctx) | |
3339 | return NULL; | |
3340 | ||
3341 | __perf_event_init_context(ctx); | |
3342 | if (task) { | |
3343 | ctx->task = task; | |
3344 | get_task_struct(task); | |
0793a61d | 3345 | } |
eb184479 PZ |
3346 | ctx->pmu = pmu; |
3347 | ||
3348 | return ctx; | |
a63eaf34 PM |
3349 | } |
3350 | ||
2ebd4ffb MH |
3351 | static struct task_struct * |
3352 | find_lively_task_by_vpid(pid_t vpid) | |
3353 | { | |
3354 | struct task_struct *task; | |
3355 | int err; | |
0793a61d TG |
3356 | |
3357 | rcu_read_lock(); | |
2ebd4ffb | 3358 | if (!vpid) |
0793a61d TG |
3359 | task = current; |
3360 | else | |
2ebd4ffb | 3361 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3362 | if (task) |
3363 | get_task_struct(task); | |
3364 | rcu_read_unlock(); | |
3365 | ||
3366 | if (!task) | |
3367 | return ERR_PTR(-ESRCH); | |
3368 | ||
0793a61d | 3369 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3370 | err = -EACCES; |
caaee623 | 3371 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3372 | goto errout; |
3373 | ||
2ebd4ffb MH |
3374 | return task; |
3375 | errout: | |
3376 | put_task_struct(task); | |
3377 | return ERR_PTR(err); | |
3378 | ||
3379 | } | |
3380 | ||
fe4b04fa PZ |
3381 | /* |
3382 | * Returns a matching context with refcount and pincount. | |
3383 | */ | |
108b02cf | 3384 | static struct perf_event_context * |
4af57ef2 YZ |
3385 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3386 | struct perf_event *event) | |
0793a61d | 3387 | { |
211de6eb | 3388 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3389 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3390 | void *task_ctx_data = NULL; |
25346b93 | 3391 | unsigned long flags; |
8dc85d54 | 3392 | int ctxn, err; |
4af57ef2 | 3393 | int cpu = event->cpu; |
0793a61d | 3394 | |
22a4ec72 | 3395 | if (!task) { |
cdd6c482 | 3396 | /* Must be root to operate on a CPU event: */ |
0764771d | 3397 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3398 | return ERR_PTR(-EACCES); |
3399 | ||
0793a61d | 3400 | /* |
cdd6c482 | 3401 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3402 | * offline CPU and activate it when the CPU comes up, but |
3403 | * that's for later. | |
3404 | */ | |
f6325e30 | 3405 | if (!cpu_online(cpu)) |
0793a61d TG |
3406 | return ERR_PTR(-ENODEV); |
3407 | ||
108b02cf | 3408 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3409 | ctx = &cpuctx->ctx; |
c93f7669 | 3410 | get_ctx(ctx); |
fe4b04fa | 3411 | ++ctx->pin_count; |
0793a61d | 3412 | |
0793a61d TG |
3413 | return ctx; |
3414 | } | |
3415 | ||
8dc85d54 PZ |
3416 | err = -EINVAL; |
3417 | ctxn = pmu->task_ctx_nr; | |
3418 | if (ctxn < 0) | |
3419 | goto errout; | |
3420 | ||
4af57ef2 YZ |
3421 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3422 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3423 | if (!task_ctx_data) { | |
3424 | err = -ENOMEM; | |
3425 | goto errout; | |
3426 | } | |
3427 | } | |
3428 | ||
9ed6060d | 3429 | retry: |
8dc85d54 | 3430 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3431 | if (ctx) { |
211de6eb | 3432 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3433 | ++ctx->pin_count; |
4af57ef2 YZ |
3434 | |
3435 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3436 | ctx->task_ctx_data = task_ctx_data; | |
3437 | task_ctx_data = NULL; | |
3438 | } | |
e625cce1 | 3439 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3440 | |
3441 | if (clone_ctx) | |
3442 | put_ctx(clone_ctx); | |
9137fb28 | 3443 | } else { |
eb184479 | 3444 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3445 | err = -ENOMEM; |
3446 | if (!ctx) | |
3447 | goto errout; | |
eb184479 | 3448 | |
4af57ef2 YZ |
3449 | if (task_ctx_data) { |
3450 | ctx->task_ctx_data = task_ctx_data; | |
3451 | task_ctx_data = NULL; | |
3452 | } | |
3453 | ||
dbe08d82 ON |
3454 | err = 0; |
3455 | mutex_lock(&task->perf_event_mutex); | |
3456 | /* | |
3457 | * If it has already passed perf_event_exit_task(). | |
3458 | * we must see PF_EXITING, it takes this mutex too. | |
3459 | */ | |
3460 | if (task->flags & PF_EXITING) | |
3461 | err = -ESRCH; | |
3462 | else if (task->perf_event_ctxp[ctxn]) | |
3463 | err = -EAGAIN; | |
fe4b04fa | 3464 | else { |
9137fb28 | 3465 | get_ctx(ctx); |
fe4b04fa | 3466 | ++ctx->pin_count; |
dbe08d82 | 3467 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3468 | } |
dbe08d82 ON |
3469 | mutex_unlock(&task->perf_event_mutex); |
3470 | ||
3471 | if (unlikely(err)) { | |
9137fb28 | 3472 | put_ctx(ctx); |
dbe08d82 ON |
3473 | |
3474 | if (err == -EAGAIN) | |
3475 | goto retry; | |
3476 | goto errout; | |
a63eaf34 PM |
3477 | } |
3478 | } | |
3479 | ||
4af57ef2 | 3480 | kfree(task_ctx_data); |
0793a61d | 3481 | return ctx; |
c93f7669 | 3482 | |
9ed6060d | 3483 | errout: |
4af57ef2 | 3484 | kfree(task_ctx_data); |
c93f7669 | 3485 | return ERR_PTR(err); |
0793a61d TG |
3486 | } |
3487 | ||
6fb2915d | 3488 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3489 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3490 | |
cdd6c482 | 3491 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3492 | { |
cdd6c482 | 3493 | struct perf_event *event; |
592903cd | 3494 | |
cdd6c482 IM |
3495 | event = container_of(head, struct perf_event, rcu_head); |
3496 | if (event->ns) | |
3497 | put_pid_ns(event->ns); | |
6fb2915d | 3498 | perf_event_free_filter(event); |
cdd6c482 | 3499 | kfree(event); |
592903cd PZ |
3500 | } |
3501 | ||
b69cf536 PZ |
3502 | static void ring_buffer_attach(struct perf_event *event, |
3503 | struct ring_buffer *rb); | |
925d519a | 3504 | |
4beb31f3 | 3505 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3506 | { |
4beb31f3 FW |
3507 | if (event->parent) |
3508 | return; | |
3509 | ||
4beb31f3 FW |
3510 | if (is_cgroup_event(event)) |
3511 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3512 | } | |
925d519a | 3513 | |
4beb31f3 FW |
3514 | static void unaccount_event(struct perf_event *event) |
3515 | { | |
25432ae9 PZ |
3516 | bool dec = false; |
3517 | ||
4beb31f3 FW |
3518 | if (event->parent) |
3519 | return; | |
3520 | ||
3521 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3522 | dec = true; |
4beb31f3 FW |
3523 | if (event->attr.mmap || event->attr.mmap_data) |
3524 | atomic_dec(&nr_mmap_events); | |
3525 | if (event->attr.comm) | |
3526 | atomic_dec(&nr_comm_events); | |
3527 | if (event->attr.task) | |
3528 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3529 | if (event->attr.freq) |
3530 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3531 | if (event->attr.context_switch) { |
25432ae9 | 3532 | dec = true; |
45ac1403 AH |
3533 | atomic_dec(&nr_switch_events); |
3534 | } | |
4beb31f3 | 3535 | if (is_cgroup_event(event)) |
25432ae9 | 3536 | dec = true; |
4beb31f3 | 3537 | if (has_branch_stack(event)) |
25432ae9 PZ |
3538 | dec = true; |
3539 | ||
3540 | if (dec) | |
4beb31f3 FW |
3541 | static_key_slow_dec_deferred(&perf_sched_events); |
3542 | ||
3543 | unaccount_event_cpu(event, event->cpu); | |
3544 | } | |
925d519a | 3545 | |
bed5b25a AS |
3546 | /* |
3547 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3548 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3549 | * at a time, so we disallow creating events that might conflict, namely: | |
3550 | * | |
3551 | * 1) cpu-wide events in the presence of per-task events, | |
3552 | * 2) per-task events in the presence of cpu-wide events, | |
3553 | * 3) two matching events on the same context. | |
3554 | * | |
3555 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3556 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3557 | */ |
3558 | static int exclusive_event_init(struct perf_event *event) | |
3559 | { | |
3560 | struct pmu *pmu = event->pmu; | |
3561 | ||
3562 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3563 | return 0; | |
3564 | ||
3565 | /* | |
3566 | * Prevent co-existence of per-task and cpu-wide events on the | |
3567 | * same exclusive pmu. | |
3568 | * | |
3569 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3570 | * events on this "exclusive" pmu, positive means there are | |
3571 | * per-task events. | |
3572 | * | |
3573 | * Since this is called in perf_event_alloc() path, event::ctx | |
3574 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3575 | * to mean "per-task event", because unlike other attach states it | |
3576 | * never gets cleared. | |
3577 | */ | |
3578 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3579 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3580 | return -EBUSY; | |
3581 | } else { | |
3582 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3583 | return -EBUSY; | |
3584 | } | |
3585 | ||
3586 | return 0; | |
3587 | } | |
3588 | ||
3589 | static void exclusive_event_destroy(struct perf_event *event) | |
3590 | { | |
3591 | struct pmu *pmu = event->pmu; | |
3592 | ||
3593 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3594 | return; | |
3595 | ||
3596 | /* see comment in exclusive_event_init() */ | |
3597 | if (event->attach_state & PERF_ATTACH_TASK) | |
3598 | atomic_dec(&pmu->exclusive_cnt); | |
3599 | else | |
3600 | atomic_inc(&pmu->exclusive_cnt); | |
3601 | } | |
3602 | ||
3603 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3604 | { | |
3605 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3606 | (e1->cpu == e2->cpu || | |
3607 | e1->cpu == -1 || | |
3608 | e2->cpu == -1)) | |
3609 | return true; | |
3610 | return false; | |
3611 | } | |
3612 | ||
3613 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3614 | static bool exclusive_event_installable(struct perf_event *event, | |
3615 | struct perf_event_context *ctx) | |
3616 | { | |
3617 | struct perf_event *iter_event; | |
3618 | struct pmu *pmu = event->pmu; | |
3619 | ||
3620 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3621 | return true; | |
3622 | ||
3623 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3624 | if (exclusive_event_match(iter_event, event)) | |
3625 | return false; | |
3626 | } | |
3627 | ||
3628 | return true; | |
3629 | } | |
3630 | ||
683ede43 | 3631 | static void _free_event(struct perf_event *event) |
f1600952 | 3632 | { |
e360adbe | 3633 | irq_work_sync(&event->pending); |
925d519a | 3634 | |
4beb31f3 | 3635 | unaccount_event(event); |
9ee318a7 | 3636 | |
76369139 | 3637 | if (event->rb) { |
9bb5d40c PZ |
3638 | /* |
3639 | * Can happen when we close an event with re-directed output. | |
3640 | * | |
3641 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3642 | * over us; possibly making our ring_buffer_put() the last. | |
3643 | */ | |
3644 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3645 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3646 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3647 | } |
3648 | ||
e5d1367f SE |
3649 | if (is_cgroup_event(event)) |
3650 | perf_detach_cgroup(event); | |
3651 | ||
a0733e69 PZ |
3652 | if (!event->parent) { |
3653 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3654 | put_callchain_buffers(); | |
3655 | } | |
3656 | ||
3657 | perf_event_free_bpf_prog(event); | |
3658 | ||
3659 | if (event->destroy) | |
3660 | event->destroy(event); | |
3661 | ||
3662 | if (event->ctx) | |
3663 | put_ctx(event->ctx); | |
3664 | ||
3665 | if (event->pmu) { | |
3666 | exclusive_event_destroy(event); | |
3667 | module_put(event->pmu->module); | |
3668 | } | |
3669 | ||
3670 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3671 | } |
3672 | ||
683ede43 PZ |
3673 | /* |
3674 | * Used to free events which have a known refcount of 1, such as in error paths | |
3675 | * where the event isn't exposed yet and inherited events. | |
3676 | */ | |
3677 | static void free_event(struct perf_event *event) | |
0793a61d | 3678 | { |
683ede43 PZ |
3679 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3680 | "unexpected event refcount: %ld; ptr=%p\n", | |
3681 | atomic_long_read(&event->refcount), event)) { | |
3682 | /* leak to avoid use-after-free */ | |
3683 | return; | |
3684 | } | |
0793a61d | 3685 | |
683ede43 | 3686 | _free_event(event); |
0793a61d TG |
3687 | } |
3688 | ||
a66a3052 | 3689 | /* |
f8697762 | 3690 | * Remove user event from the owner task. |
a66a3052 | 3691 | */ |
f8697762 | 3692 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3693 | { |
8882135b | 3694 | struct task_struct *owner; |
fb0459d7 | 3695 | |
8882135b | 3696 | rcu_read_lock(); |
8882135b | 3697 | /* |
f47c02c0 PZ |
3698 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3699 | * observe !owner it means the list deletion is complete and we can | |
3700 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3701 | * owner->perf_event_mutex. |
3702 | */ | |
f47c02c0 | 3703 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3704 | if (owner) { |
3705 | /* | |
3706 | * Since delayed_put_task_struct() also drops the last | |
3707 | * task reference we can safely take a new reference | |
3708 | * while holding the rcu_read_lock(). | |
3709 | */ | |
3710 | get_task_struct(owner); | |
3711 | } | |
3712 | rcu_read_unlock(); | |
3713 | ||
3714 | if (owner) { | |
f63a8daa PZ |
3715 | /* |
3716 | * If we're here through perf_event_exit_task() we're already | |
3717 | * holding ctx->mutex which would be an inversion wrt. the | |
3718 | * normal lock order. | |
3719 | * | |
3720 | * However we can safely take this lock because its the child | |
3721 | * ctx->mutex. | |
3722 | */ | |
3723 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3724 | ||
8882135b PZ |
3725 | /* |
3726 | * We have to re-check the event->owner field, if it is cleared | |
3727 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3728 | * ensured they're done, and we can proceed with freeing the | |
3729 | * event. | |
3730 | */ | |
f47c02c0 | 3731 | if (event->owner) { |
8882135b | 3732 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3733 | smp_store_release(&event->owner, NULL); |
3734 | } | |
8882135b PZ |
3735 | mutex_unlock(&owner->perf_event_mutex); |
3736 | put_task_struct(owner); | |
3737 | } | |
f8697762 JO |
3738 | } |
3739 | ||
f8697762 JO |
3740 | static void put_event(struct perf_event *event) |
3741 | { | |
f8697762 JO |
3742 | if (!atomic_long_dec_and_test(&event->refcount)) |
3743 | return; | |
3744 | ||
c6e5b732 PZ |
3745 | _free_event(event); |
3746 | } | |
3747 | ||
3748 | /* | |
3749 | * Kill an event dead; while event:refcount will preserve the event | |
3750 | * object, it will not preserve its functionality. Once the last 'user' | |
3751 | * gives up the object, we'll destroy the thing. | |
3752 | */ | |
3753 | int perf_event_release_kernel(struct perf_event *event) | |
3754 | { | |
3755 | struct perf_event_context *ctx; | |
3756 | struct perf_event *child, *tmp; | |
3757 | ||
f8697762 JO |
3758 | if (!is_kernel_event(event)) |
3759 | perf_remove_from_owner(event); | |
8882135b | 3760 | |
5fa7c8ec | 3761 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3762 | WARN_ON_ONCE(ctx->parent_ctx); |
60beda84 | 3763 | perf_remove_from_context(event, DETACH_GROUP | DETACH_STATE); |
d415a7f1 | 3764 | perf_event_ctx_unlock(event, ctx); |
683ede43 | 3765 | |
683ede43 | 3766 | /* |
60beda84 PZ |
3767 | * At this point we must have event->state == PERF_EVENT_STATE_EXIT, |
3768 | * either from the above perf_remove_from_context() or through | |
3769 | * perf_event_exit_event(). | |
683ede43 | 3770 | * |
c6e5b732 PZ |
3771 | * Therefore, anybody acquiring event->child_mutex after the below |
3772 | * loop _must_ also see this, most importantly inherit_event() which | |
3773 | * will avoid placing more children on the list. | |
683ede43 | 3774 | * |
c6e5b732 PZ |
3775 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3776 | * child events. | |
683ede43 | 3777 | */ |
60beda84 | 3778 | WARN_ON_ONCE(event->state != PERF_EVENT_STATE_EXIT); |
683ede43 | 3779 | |
c6e5b732 PZ |
3780 | again: |
3781 | mutex_lock(&event->child_mutex); | |
3782 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3783 | |
c6e5b732 PZ |
3784 | /* |
3785 | * Cannot change, child events are not migrated, see the | |
3786 | * comment with perf_event_ctx_lock_nested(). | |
3787 | */ | |
3788 | ctx = lockless_dereference(child->ctx); | |
3789 | /* | |
3790 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3791 | * through hoops. We start by grabbing a reference on the ctx. | |
3792 | * | |
3793 | * Since the event cannot get freed while we hold the | |
3794 | * child_mutex, the context must also exist and have a !0 | |
3795 | * reference count. | |
3796 | */ | |
3797 | get_ctx(ctx); | |
3798 | ||
3799 | /* | |
3800 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3801 | * acquire ctx::mutex without fear of it going away. Then we | |
3802 | * can re-acquire child_mutex. | |
3803 | */ | |
3804 | mutex_unlock(&event->child_mutex); | |
3805 | mutex_lock(&ctx->mutex); | |
3806 | mutex_lock(&event->child_mutex); | |
3807 | ||
3808 | /* | |
3809 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3810 | * state, if child is still the first entry, it didn't get freed | |
3811 | * and we can continue doing so. | |
3812 | */ | |
3813 | tmp = list_first_entry_or_null(&event->child_list, | |
3814 | struct perf_event, child_list); | |
3815 | if (tmp == child) { | |
3816 | perf_remove_from_context(child, DETACH_GROUP); | |
3817 | list_del(&child->child_list); | |
3818 | free_event(child); | |
3819 | /* | |
3820 | * This matches the refcount bump in inherit_event(); | |
3821 | * this can't be the last reference. | |
3822 | */ | |
3823 | put_event(event); | |
3824 | } | |
3825 | ||
3826 | mutex_unlock(&event->child_mutex); | |
3827 | mutex_unlock(&ctx->mutex); | |
3828 | put_ctx(ctx); | |
3829 | goto again; | |
3830 | } | |
3831 | mutex_unlock(&event->child_mutex); | |
3832 | ||
3833 | /* Must be the last reference */ | |
683ede43 PZ |
3834 | put_event(event); |
3835 | return 0; | |
3836 | } | |
3837 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3838 | ||
8b10c5e2 PZ |
3839 | /* |
3840 | * Called when the last reference to the file is gone. | |
3841 | */ | |
a6fa941d AV |
3842 | static int perf_release(struct inode *inode, struct file *file) |
3843 | { | |
c6e5b732 | 3844 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3845 | return 0; |
fb0459d7 | 3846 | } |
fb0459d7 | 3847 | |
59ed446f | 3848 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3849 | { |
cdd6c482 | 3850 | struct perf_event *child; |
e53c0994 PZ |
3851 | u64 total = 0; |
3852 | ||
59ed446f PZ |
3853 | *enabled = 0; |
3854 | *running = 0; | |
3855 | ||
6f10581a | 3856 | mutex_lock(&event->child_mutex); |
01add3ea | 3857 | |
7d88962e | 3858 | (void)perf_event_read(event, false); |
01add3ea SB |
3859 | total += perf_event_count(event); |
3860 | ||
59ed446f PZ |
3861 | *enabled += event->total_time_enabled + |
3862 | atomic64_read(&event->child_total_time_enabled); | |
3863 | *running += event->total_time_running + | |
3864 | atomic64_read(&event->child_total_time_running); | |
3865 | ||
3866 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3867 | (void)perf_event_read(child, false); |
01add3ea | 3868 | total += perf_event_count(child); |
59ed446f PZ |
3869 | *enabled += child->total_time_enabled; |
3870 | *running += child->total_time_running; | |
3871 | } | |
6f10581a | 3872 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3873 | |
3874 | return total; | |
3875 | } | |
fb0459d7 | 3876 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3877 | |
7d88962e | 3878 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3879 | u64 read_format, u64 *values) |
3dab77fb | 3880 | { |
fa8c2693 PZ |
3881 | struct perf_event *sub; |
3882 | int n = 1; /* skip @nr */ | |
7d88962e | 3883 | int ret; |
f63a8daa | 3884 | |
7d88962e SB |
3885 | ret = perf_event_read(leader, true); |
3886 | if (ret) | |
3887 | return ret; | |
abf4868b | 3888 | |
fa8c2693 PZ |
3889 | /* |
3890 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3891 | * will be identical to those of the leader, so we only publish one | |
3892 | * set. | |
3893 | */ | |
3894 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3895 | values[n++] += leader->total_time_enabled + | |
3896 | atomic64_read(&leader->child_total_time_enabled); | |
3897 | } | |
3dab77fb | 3898 | |
fa8c2693 PZ |
3899 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3900 | values[n++] += leader->total_time_running + | |
3901 | atomic64_read(&leader->child_total_time_running); | |
3902 | } | |
3903 | ||
3904 | /* | |
3905 | * Write {count,id} tuples for every sibling. | |
3906 | */ | |
3907 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3908 | if (read_format & PERF_FORMAT_ID) |
3909 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3910 | |
fa8c2693 PZ |
3911 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3912 | values[n++] += perf_event_count(sub); | |
3913 | if (read_format & PERF_FORMAT_ID) | |
3914 | values[n++] = primary_event_id(sub); | |
3915 | } | |
7d88962e SB |
3916 | |
3917 | return 0; | |
fa8c2693 | 3918 | } |
3dab77fb | 3919 | |
fa8c2693 PZ |
3920 | static int perf_read_group(struct perf_event *event, |
3921 | u64 read_format, char __user *buf) | |
3922 | { | |
3923 | struct perf_event *leader = event->group_leader, *child; | |
3924 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3925 | int ret; |
fa8c2693 | 3926 | u64 *values; |
3dab77fb | 3927 | |
fa8c2693 | 3928 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3929 | |
fa8c2693 PZ |
3930 | values = kzalloc(event->read_size, GFP_KERNEL); |
3931 | if (!values) | |
3932 | return -ENOMEM; | |
3dab77fb | 3933 | |
fa8c2693 PZ |
3934 | values[0] = 1 + leader->nr_siblings; |
3935 | ||
3936 | /* | |
3937 | * By locking the child_mutex of the leader we effectively | |
3938 | * lock the child list of all siblings.. XXX explain how. | |
3939 | */ | |
3940 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3941 | |
7d88962e SB |
3942 | ret = __perf_read_group_add(leader, read_format, values); |
3943 | if (ret) | |
3944 | goto unlock; | |
3945 | ||
3946 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3947 | ret = __perf_read_group_add(child, read_format, values); | |
3948 | if (ret) | |
3949 | goto unlock; | |
3950 | } | |
abf4868b | 3951 | |
fa8c2693 | 3952 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3953 | |
7d88962e | 3954 | ret = event->read_size; |
fa8c2693 PZ |
3955 | if (copy_to_user(buf, values, event->read_size)) |
3956 | ret = -EFAULT; | |
7d88962e | 3957 | goto out; |
fa8c2693 | 3958 | |
7d88962e SB |
3959 | unlock: |
3960 | mutex_unlock(&leader->child_mutex); | |
3961 | out: | |
fa8c2693 | 3962 | kfree(values); |
abf4868b | 3963 | return ret; |
3dab77fb PZ |
3964 | } |
3965 | ||
b15f495b | 3966 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3967 | u64 read_format, char __user *buf) |
3968 | { | |
59ed446f | 3969 | u64 enabled, running; |
3dab77fb PZ |
3970 | u64 values[4]; |
3971 | int n = 0; | |
3972 | ||
59ed446f PZ |
3973 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3974 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3975 | values[n++] = enabled; | |
3976 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3977 | values[n++] = running; | |
3dab77fb | 3978 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3979 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3980 | |
3981 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3982 | return -EFAULT; | |
3983 | ||
3984 | return n * sizeof(u64); | |
3985 | } | |
3986 | ||
dc633982 JO |
3987 | static bool is_event_hup(struct perf_event *event) |
3988 | { | |
3989 | bool no_children; | |
3990 | ||
3991 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3992 | return false; | |
3993 | ||
3994 | mutex_lock(&event->child_mutex); | |
3995 | no_children = list_empty(&event->child_list); | |
3996 | mutex_unlock(&event->child_mutex); | |
3997 | return no_children; | |
3998 | } | |
3999 | ||
0793a61d | 4000 | /* |
cdd6c482 | 4001 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4002 | */ |
4003 | static ssize_t | |
b15f495b | 4004 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4005 | { |
cdd6c482 | 4006 | u64 read_format = event->attr.read_format; |
3dab77fb | 4007 | int ret; |
0793a61d | 4008 | |
3b6f9e5c | 4009 | /* |
cdd6c482 | 4010 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4011 | * error state (i.e. because it was pinned but it couldn't be |
4012 | * scheduled on to the CPU at some point). | |
4013 | */ | |
cdd6c482 | 4014 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4015 | return 0; |
4016 | ||
c320c7b7 | 4017 | if (count < event->read_size) |
3dab77fb PZ |
4018 | return -ENOSPC; |
4019 | ||
cdd6c482 | 4020 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4021 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4022 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4023 | else |
b15f495b | 4024 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4025 | |
3dab77fb | 4026 | return ret; |
0793a61d TG |
4027 | } |
4028 | ||
0793a61d TG |
4029 | static ssize_t |
4030 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4031 | { | |
cdd6c482 | 4032 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4033 | struct perf_event_context *ctx; |
4034 | int ret; | |
0793a61d | 4035 | |
f63a8daa | 4036 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4037 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4038 | perf_event_ctx_unlock(event, ctx); |
4039 | ||
4040 | return ret; | |
0793a61d TG |
4041 | } |
4042 | ||
4043 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4044 | { | |
cdd6c482 | 4045 | struct perf_event *event = file->private_data; |
76369139 | 4046 | struct ring_buffer *rb; |
61b67684 | 4047 | unsigned int events = POLLHUP; |
c7138f37 | 4048 | |
e708d7ad | 4049 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4050 | |
dc633982 | 4051 | if (is_event_hup(event)) |
179033b3 | 4052 | return events; |
c7138f37 | 4053 | |
10c6db11 | 4054 | /* |
9bb5d40c PZ |
4055 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4056 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4057 | */ |
4058 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4059 | rb = event->rb; |
4060 | if (rb) | |
76369139 | 4061 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4062 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4063 | return events; |
4064 | } | |
4065 | ||
f63a8daa | 4066 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4067 | { |
7d88962e | 4068 | (void)perf_event_read(event, false); |
e7850595 | 4069 | local64_set(&event->count, 0); |
cdd6c482 | 4070 | perf_event_update_userpage(event); |
3df5edad PZ |
4071 | } |
4072 | ||
c93f7669 | 4073 | /* |
cdd6c482 IM |
4074 | * Holding the top-level event's child_mutex means that any |
4075 | * descendant process that has inherited this event will block | |
8ba289b8 | 4076 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4077 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4078 | */ |
cdd6c482 IM |
4079 | static void perf_event_for_each_child(struct perf_event *event, |
4080 | void (*func)(struct perf_event *)) | |
3df5edad | 4081 | { |
cdd6c482 | 4082 | struct perf_event *child; |
3df5edad | 4083 | |
cdd6c482 | 4084 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4085 | |
cdd6c482 IM |
4086 | mutex_lock(&event->child_mutex); |
4087 | func(event); | |
4088 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4089 | func(child); |
cdd6c482 | 4090 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4091 | } |
4092 | ||
cdd6c482 IM |
4093 | static void perf_event_for_each(struct perf_event *event, |
4094 | void (*func)(struct perf_event *)) | |
3df5edad | 4095 | { |
cdd6c482 IM |
4096 | struct perf_event_context *ctx = event->ctx; |
4097 | struct perf_event *sibling; | |
3df5edad | 4098 | |
f63a8daa PZ |
4099 | lockdep_assert_held(&ctx->mutex); |
4100 | ||
cdd6c482 | 4101 | event = event->group_leader; |
75f937f2 | 4102 | |
cdd6c482 | 4103 | perf_event_for_each_child(event, func); |
cdd6c482 | 4104 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4105 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4106 | } |
4107 | ||
fae3fde6 PZ |
4108 | static void __perf_event_period(struct perf_event *event, |
4109 | struct perf_cpu_context *cpuctx, | |
4110 | struct perf_event_context *ctx, | |
4111 | void *info) | |
c7999c6f | 4112 | { |
fae3fde6 | 4113 | u64 value = *((u64 *)info); |
c7999c6f | 4114 | bool active; |
08247e31 | 4115 | |
cdd6c482 | 4116 | if (event->attr.freq) { |
cdd6c482 | 4117 | event->attr.sample_freq = value; |
08247e31 | 4118 | } else { |
cdd6c482 IM |
4119 | event->attr.sample_period = value; |
4120 | event->hw.sample_period = value; | |
08247e31 | 4121 | } |
bad7192b PZ |
4122 | |
4123 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4124 | if (active) { | |
4125 | perf_pmu_disable(ctx->pmu); | |
4126 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4127 | } | |
4128 | ||
4129 | local64_set(&event->hw.period_left, 0); | |
4130 | ||
4131 | if (active) { | |
4132 | event->pmu->start(event, PERF_EF_RELOAD); | |
4133 | perf_pmu_enable(ctx->pmu); | |
4134 | } | |
c7999c6f PZ |
4135 | } |
4136 | ||
4137 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4138 | { | |
c7999c6f PZ |
4139 | u64 value; |
4140 | ||
4141 | if (!is_sampling_event(event)) | |
4142 | return -EINVAL; | |
4143 | ||
4144 | if (copy_from_user(&value, arg, sizeof(value))) | |
4145 | return -EFAULT; | |
4146 | ||
4147 | if (!value) | |
4148 | return -EINVAL; | |
4149 | ||
4150 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4151 | return -EINVAL; | |
4152 | ||
fae3fde6 | 4153 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4154 | |
c7999c6f | 4155 | return 0; |
08247e31 PZ |
4156 | } |
4157 | ||
ac9721f3 PZ |
4158 | static const struct file_operations perf_fops; |
4159 | ||
2903ff01 | 4160 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4161 | { |
2903ff01 AV |
4162 | struct fd f = fdget(fd); |
4163 | if (!f.file) | |
4164 | return -EBADF; | |
ac9721f3 | 4165 | |
2903ff01 AV |
4166 | if (f.file->f_op != &perf_fops) { |
4167 | fdput(f); | |
4168 | return -EBADF; | |
ac9721f3 | 4169 | } |
2903ff01 AV |
4170 | *p = f; |
4171 | return 0; | |
ac9721f3 PZ |
4172 | } |
4173 | ||
4174 | static int perf_event_set_output(struct perf_event *event, | |
4175 | struct perf_event *output_event); | |
6fb2915d | 4176 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4177 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4178 | |
f63a8daa | 4179 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4180 | { |
cdd6c482 | 4181 | void (*func)(struct perf_event *); |
3df5edad | 4182 | u32 flags = arg; |
d859e29f PM |
4183 | |
4184 | switch (cmd) { | |
cdd6c482 | 4185 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4186 | func = _perf_event_enable; |
d859e29f | 4187 | break; |
cdd6c482 | 4188 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4189 | func = _perf_event_disable; |
79f14641 | 4190 | break; |
cdd6c482 | 4191 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4192 | func = _perf_event_reset; |
6de6a7b9 | 4193 | break; |
3df5edad | 4194 | |
cdd6c482 | 4195 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4196 | return _perf_event_refresh(event, arg); |
08247e31 | 4197 | |
cdd6c482 IM |
4198 | case PERF_EVENT_IOC_PERIOD: |
4199 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4200 | |
cf4957f1 JO |
4201 | case PERF_EVENT_IOC_ID: |
4202 | { | |
4203 | u64 id = primary_event_id(event); | |
4204 | ||
4205 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4206 | return -EFAULT; | |
4207 | return 0; | |
4208 | } | |
4209 | ||
cdd6c482 | 4210 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4211 | { |
ac9721f3 | 4212 | int ret; |
ac9721f3 | 4213 | if (arg != -1) { |
2903ff01 AV |
4214 | struct perf_event *output_event; |
4215 | struct fd output; | |
4216 | ret = perf_fget_light(arg, &output); | |
4217 | if (ret) | |
4218 | return ret; | |
4219 | output_event = output.file->private_data; | |
4220 | ret = perf_event_set_output(event, output_event); | |
4221 | fdput(output); | |
4222 | } else { | |
4223 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4224 | } |
ac9721f3 PZ |
4225 | return ret; |
4226 | } | |
a4be7c27 | 4227 | |
6fb2915d LZ |
4228 | case PERF_EVENT_IOC_SET_FILTER: |
4229 | return perf_event_set_filter(event, (void __user *)arg); | |
4230 | ||
2541517c AS |
4231 | case PERF_EVENT_IOC_SET_BPF: |
4232 | return perf_event_set_bpf_prog(event, arg); | |
4233 | ||
d859e29f | 4234 | default: |
3df5edad | 4235 | return -ENOTTY; |
d859e29f | 4236 | } |
3df5edad PZ |
4237 | |
4238 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4239 | perf_event_for_each(event, func); |
3df5edad | 4240 | else |
cdd6c482 | 4241 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4242 | |
4243 | return 0; | |
d859e29f PM |
4244 | } |
4245 | ||
f63a8daa PZ |
4246 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4247 | { | |
4248 | struct perf_event *event = file->private_data; | |
4249 | struct perf_event_context *ctx; | |
4250 | long ret; | |
4251 | ||
4252 | ctx = perf_event_ctx_lock(event); | |
4253 | ret = _perf_ioctl(event, cmd, arg); | |
4254 | perf_event_ctx_unlock(event, ctx); | |
4255 | ||
4256 | return ret; | |
4257 | } | |
4258 | ||
b3f20785 PM |
4259 | #ifdef CONFIG_COMPAT |
4260 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4261 | unsigned long arg) | |
4262 | { | |
4263 | switch (_IOC_NR(cmd)) { | |
4264 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4265 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4266 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4267 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4268 | cmd &= ~IOCSIZE_MASK; | |
4269 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4270 | } | |
4271 | break; | |
4272 | } | |
4273 | return perf_ioctl(file, cmd, arg); | |
4274 | } | |
4275 | #else | |
4276 | # define perf_compat_ioctl NULL | |
4277 | #endif | |
4278 | ||
cdd6c482 | 4279 | int perf_event_task_enable(void) |
771d7cde | 4280 | { |
f63a8daa | 4281 | struct perf_event_context *ctx; |
cdd6c482 | 4282 | struct perf_event *event; |
771d7cde | 4283 | |
cdd6c482 | 4284 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4285 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4286 | ctx = perf_event_ctx_lock(event); | |
4287 | perf_event_for_each_child(event, _perf_event_enable); | |
4288 | perf_event_ctx_unlock(event, ctx); | |
4289 | } | |
cdd6c482 | 4290 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4291 | |
4292 | return 0; | |
4293 | } | |
4294 | ||
cdd6c482 | 4295 | int perf_event_task_disable(void) |
771d7cde | 4296 | { |
f63a8daa | 4297 | struct perf_event_context *ctx; |
cdd6c482 | 4298 | struct perf_event *event; |
771d7cde | 4299 | |
cdd6c482 | 4300 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4301 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4302 | ctx = perf_event_ctx_lock(event); | |
4303 | perf_event_for_each_child(event, _perf_event_disable); | |
4304 | perf_event_ctx_unlock(event, ctx); | |
4305 | } | |
cdd6c482 | 4306 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4307 | |
4308 | return 0; | |
4309 | } | |
4310 | ||
cdd6c482 | 4311 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4312 | { |
a4eaf7f1 PZ |
4313 | if (event->hw.state & PERF_HES_STOPPED) |
4314 | return 0; | |
4315 | ||
cdd6c482 | 4316 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4317 | return 0; |
4318 | ||
35edc2a5 | 4319 | return event->pmu->event_idx(event); |
194002b2 PZ |
4320 | } |
4321 | ||
c4794295 | 4322 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4323 | u64 *now, |
7f310a5d EM |
4324 | u64 *enabled, |
4325 | u64 *running) | |
c4794295 | 4326 | { |
e3f3541c | 4327 | u64 ctx_time; |
c4794295 | 4328 | |
e3f3541c PZ |
4329 | *now = perf_clock(); |
4330 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4331 | *enabled = ctx_time - event->tstamp_enabled; |
4332 | *running = ctx_time - event->tstamp_running; | |
4333 | } | |
4334 | ||
fa731587 PZ |
4335 | static void perf_event_init_userpage(struct perf_event *event) |
4336 | { | |
4337 | struct perf_event_mmap_page *userpg; | |
4338 | struct ring_buffer *rb; | |
4339 | ||
4340 | rcu_read_lock(); | |
4341 | rb = rcu_dereference(event->rb); | |
4342 | if (!rb) | |
4343 | goto unlock; | |
4344 | ||
4345 | userpg = rb->user_page; | |
4346 | ||
4347 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4348 | userpg->cap_bit0_is_deprecated = 1; | |
4349 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4350 | userpg->data_offset = PAGE_SIZE; |
4351 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4352 | |
4353 | unlock: | |
4354 | rcu_read_unlock(); | |
4355 | } | |
4356 | ||
c1317ec2 AL |
4357 | void __weak arch_perf_update_userpage( |
4358 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4359 | { |
4360 | } | |
4361 | ||
38ff667b PZ |
4362 | /* |
4363 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4364 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4365 | * code calls this from NMI context. | |
4366 | */ | |
cdd6c482 | 4367 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4368 | { |
cdd6c482 | 4369 | struct perf_event_mmap_page *userpg; |
76369139 | 4370 | struct ring_buffer *rb; |
e3f3541c | 4371 | u64 enabled, running, now; |
38ff667b PZ |
4372 | |
4373 | rcu_read_lock(); | |
5ec4c599 PZ |
4374 | rb = rcu_dereference(event->rb); |
4375 | if (!rb) | |
4376 | goto unlock; | |
4377 | ||
0d641208 EM |
4378 | /* |
4379 | * compute total_time_enabled, total_time_running | |
4380 | * based on snapshot values taken when the event | |
4381 | * was last scheduled in. | |
4382 | * | |
4383 | * we cannot simply called update_context_time() | |
4384 | * because of locking issue as we can be called in | |
4385 | * NMI context | |
4386 | */ | |
e3f3541c | 4387 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4388 | |
76369139 | 4389 | userpg = rb->user_page; |
7b732a75 PZ |
4390 | /* |
4391 | * Disable preemption so as to not let the corresponding user-space | |
4392 | * spin too long if we get preempted. | |
4393 | */ | |
4394 | preempt_disable(); | |
37d81828 | 4395 | ++userpg->lock; |
92f22a38 | 4396 | barrier(); |
cdd6c482 | 4397 | userpg->index = perf_event_index(event); |
b5e58793 | 4398 | userpg->offset = perf_event_count(event); |
365a4038 | 4399 | if (userpg->index) |
e7850595 | 4400 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4401 | |
0d641208 | 4402 | userpg->time_enabled = enabled + |
cdd6c482 | 4403 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4404 | |
0d641208 | 4405 | userpg->time_running = running + |
cdd6c482 | 4406 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4407 | |
c1317ec2 | 4408 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4409 | |
92f22a38 | 4410 | barrier(); |
37d81828 | 4411 | ++userpg->lock; |
7b732a75 | 4412 | preempt_enable(); |
38ff667b | 4413 | unlock: |
7b732a75 | 4414 | rcu_read_unlock(); |
37d81828 PM |
4415 | } |
4416 | ||
906010b2 PZ |
4417 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4418 | { | |
4419 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4420 | struct ring_buffer *rb; |
906010b2 PZ |
4421 | int ret = VM_FAULT_SIGBUS; |
4422 | ||
4423 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4424 | if (vmf->pgoff == 0) | |
4425 | ret = 0; | |
4426 | return ret; | |
4427 | } | |
4428 | ||
4429 | rcu_read_lock(); | |
76369139 FW |
4430 | rb = rcu_dereference(event->rb); |
4431 | if (!rb) | |
906010b2 PZ |
4432 | goto unlock; |
4433 | ||
4434 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4435 | goto unlock; | |
4436 | ||
76369139 | 4437 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4438 | if (!vmf->page) |
4439 | goto unlock; | |
4440 | ||
4441 | get_page(vmf->page); | |
4442 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4443 | vmf->page->index = vmf->pgoff; | |
4444 | ||
4445 | ret = 0; | |
4446 | unlock: | |
4447 | rcu_read_unlock(); | |
4448 | ||
4449 | return ret; | |
4450 | } | |
4451 | ||
10c6db11 PZ |
4452 | static void ring_buffer_attach(struct perf_event *event, |
4453 | struct ring_buffer *rb) | |
4454 | { | |
b69cf536 | 4455 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4456 | unsigned long flags; |
4457 | ||
b69cf536 PZ |
4458 | if (event->rb) { |
4459 | /* | |
4460 | * Should be impossible, we set this when removing | |
4461 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4462 | */ | |
4463 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4464 | |
b69cf536 | 4465 | old_rb = event->rb; |
b69cf536 PZ |
4466 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4467 | list_del_rcu(&event->rb_entry); | |
4468 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4469 | |
2f993cf0 ON |
4470 | event->rcu_batches = get_state_synchronize_rcu(); |
4471 | event->rcu_pending = 1; | |
b69cf536 | 4472 | } |
10c6db11 | 4473 | |
b69cf536 | 4474 | if (rb) { |
2f993cf0 ON |
4475 | if (event->rcu_pending) { |
4476 | cond_synchronize_rcu(event->rcu_batches); | |
4477 | event->rcu_pending = 0; | |
4478 | } | |
4479 | ||
b69cf536 PZ |
4480 | spin_lock_irqsave(&rb->event_lock, flags); |
4481 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4482 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4483 | } | |
4484 | ||
4485 | rcu_assign_pointer(event->rb, rb); | |
4486 | ||
4487 | if (old_rb) { | |
4488 | ring_buffer_put(old_rb); | |
4489 | /* | |
4490 | * Since we detached before setting the new rb, so that we | |
4491 | * could attach the new rb, we could have missed a wakeup. | |
4492 | * Provide it now. | |
4493 | */ | |
4494 | wake_up_all(&event->waitq); | |
4495 | } | |
10c6db11 PZ |
4496 | } |
4497 | ||
4498 | static void ring_buffer_wakeup(struct perf_event *event) | |
4499 | { | |
4500 | struct ring_buffer *rb; | |
4501 | ||
4502 | rcu_read_lock(); | |
4503 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4504 | if (rb) { |
4505 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4506 | wake_up_all(&event->waitq); | |
4507 | } | |
10c6db11 PZ |
4508 | rcu_read_unlock(); |
4509 | } | |
4510 | ||
fdc26706 | 4511 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4512 | { |
76369139 | 4513 | struct ring_buffer *rb; |
7b732a75 | 4514 | |
ac9721f3 | 4515 | rcu_read_lock(); |
76369139 FW |
4516 | rb = rcu_dereference(event->rb); |
4517 | if (rb) { | |
4518 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4519 | rb = NULL; | |
ac9721f3 PZ |
4520 | } |
4521 | rcu_read_unlock(); | |
4522 | ||
76369139 | 4523 | return rb; |
ac9721f3 PZ |
4524 | } |
4525 | ||
fdc26706 | 4526 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4527 | { |
76369139 | 4528 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4529 | return; |
7b732a75 | 4530 | |
9bb5d40c | 4531 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4532 | |
76369139 | 4533 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4534 | } |
4535 | ||
4536 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4537 | { | |
cdd6c482 | 4538 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4539 | |
cdd6c482 | 4540 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4541 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4542 | |
45bfb2e5 PZ |
4543 | if (vma->vm_pgoff) |
4544 | atomic_inc(&event->rb->aux_mmap_count); | |
4545 | ||
1e0fb9ec AL |
4546 | if (event->pmu->event_mapped) |
4547 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4548 | } |
4549 | ||
9bb5d40c PZ |
4550 | /* |
4551 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4552 | * event, or through other events by use of perf_event_set_output(). | |
4553 | * | |
4554 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4555 | * the buffer here, where we still have a VM context. This means we need | |
4556 | * to detach all events redirecting to us. | |
4557 | */ | |
7b732a75 PZ |
4558 | static void perf_mmap_close(struct vm_area_struct *vma) |
4559 | { | |
cdd6c482 | 4560 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4561 | |
b69cf536 | 4562 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4563 | struct user_struct *mmap_user = rb->mmap_user; |
4564 | int mmap_locked = rb->mmap_locked; | |
4565 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4566 | |
1e0fb9ec AL |
4567 | if (event->pmu->event_unmapped) |
4568 | event->pmu->event_unmapped(event); | |
4569 | ||
45bfb2e5 PZ |
4570 | /* |
4571 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4572 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4573 | * serialize with perf_mmap here. | |
4574 | */ | |
4575 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4576 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4577 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4578 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4579 | ||
4580 | rb_free_aux(rb); | |
4581 | mutex_unlock(&event->mmap_mutex); | |
4582 | } | |
4583 | ||
9bb5d40c PZ |
4584 | atomic_dec(&rb->mmap_count); |
4585 | ||
4586 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4587 | goto out_put; |
9bb5d40c | 4588 | |
b69cf536 | 4589 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4590 | mutex_unlock(&event->mmap_mutex); |
4591 | ||
4592 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4593 | if (atomic_read(&rb->mmap_count)) |
4594 | goto out_put; | |
ac9721f3 | 4595 | |
9bb5d40c PZ |
4596 | /* |
4597 | * No other mmap()s, detach from all other events that might redirect | |
4598 | * into the now unreachable buffer. Somewhat complicated by the | |
4599 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4600 | */ | |
4601 | again: | |
4602 | rcu_read_lock(); | |
4603 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4604 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4605 | /* | |
4606 | * This event is en-route to free_event() which will | |
4607 | * detach it and remove it from the list. | |
4608 | */ | |
4609 | continue; | |
4610 | } | |
4611 | rcu_read_unlock(); | |
789f90fc | 4612 | |
9bb5d40c PZ |
4613 | mutex_lock(&event->mmap_mutex); |
4614 | /* | |
4615 | * Check we didn't race with perf_event_set_output() which can | |
4616 | * swizzle the rb from under us while we were waiting to | |
4617 | * acquire mmap_mutex. | |
4618 | * | |
4619 | * If we find a different rb; ignore this event, a next | |
4620 | * iteration will no longer find it on the list. We have to | |
4621 | * still restart the iteration to make sure we're not now | |
4622 | * iterating the wrong list. | |
4623 | */ | |
b69cf536 PZ |
4624 | if (event->rb == rb) |
4625 | ring_buffer_attach(event, NULL); | |
4626 | ||
cdd6c482 | 4627 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4628 | put_event(event); |
ac9721f3 | 4629 | |
9bb5d40c PZ |
4630 | /* |
4631 | * Restart the iteration; either we're on the wrong list or | |
4632 | * destroyed its integrity by doing a deletion. | |
4633 | */ | |
4634 | goto again; | |
7b732a75 | 4635 | } |
9bb5d40c PZ |
4636 | rcu_read_unlock(); |
4637 | ||
4638 | /* | |
4639 | * It could be there's still a few 0-ref events on the list; they'll | |
4640 | * get cleaned up by free_event() -- they'll also still have their | |
4641 | * ref on the rb and will free it whenever they are done with it. | |
4642 | * | |
4643 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4644 | * undo the VM accounting. | |
4645 | */ | |
4646 | ||
4647 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4648 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4649 | free_uid(mmap_user); | |
4650 | ||
b69cf536 | 4651 | out_put: |
9bb5d40c | 4652 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4653 | } |
4654 | ||
f0f37e2f | 4655 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4656 | .open = perf_mmap_open, |
45bfb2e5 | 4657 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4658 | .fault = perf_mmap_fault, |
4659 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4660 | }; |
4661 | ||
4662 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4663 | { | |
cdd6c482 | 4664 | struct perf_event *event = file->private_data; |
22a4f650 | 4665 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4666 | struct user_struct *user = current_user(); |
22a4f650 | 4667 | unsigned long locked, lock_limit; |
45bfb2e5 | 4668 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4669 | unsigned long vma_size; |
4670 | unsigned long nr_pages; | |
45bfb2e5 | 4671 | long user_extra = 0, extra = 0; |
d57e34fd | 4672 | int ret = 0, flags = 0; |
37d81828 | 4673 | |
c7920614 PZ |
4674 | /* |
4675 | * Don't allow mmap() of inherited per-task counters. This would | |
4676 | * create a performance issue due to all children writing to the | |
76369139 | 4677 | * same rb. |
c7920614 PZ |
4678 | */ |
4679 | if (event->cpu == -1 && event->attr.inherit) | |
4680 | return -EINVAL; | |
4681 | ||
43a21ea8 | 4682 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4683 | return -EINVAL; |
7b732a75 PZ |
4684 | |
4685 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4686 | |
4687 | if (vma->vm_pgoff == 0) { | |
4688 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4689 | } else { | |
4690 | /* | |
4691 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4692 | * mapped, all subsequent mappings should have the same size | |
4693 | * and offset. Must be above the normal perf buffer. | |
4694 | */ | |
4695 | u64 aux_offset, aux_size; | |
4696 | ||
4697 | if (!event->rb) | |
4698 | return -EINVAL; | |
4699 | ||
4700 | nr_pages = vma_size / PAGE_SIZE; | |
4701 | ||
4702 | mutex_lock(&event->mmap_mutex); | |
4703 | ret = -EINVAL; | |
4704 | ||
4705 | rb = event->rb; | |
4706 | if (!rb) | |
4707 | goto aux_unlock; | |
4708 | ||
4709 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4710 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4711 | ||
4712 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4713 | goto aux_unlock; | |
4714 | ||
4715 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4716 | goto aux_unlock; | |
4717 | ||
4718 | /* already mapped with a different offset */ | |
4719 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4720 | goto aux_unlock; | |
4721 | ||
4722 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4723 | goto aux_unlock; | |
4724 | ||
4725 | /* already mapped with a different size */ | |
4726 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4727 | goto aux_unlock; | |
4728 | ||
4729 | if (!is_power_of_2(nr_pages)) | |
4730 | goto aux_unlock; | |
4731 | ||
4732 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4733 | goto aux_unlock; | |
4734 | ||
4735 | if (rb_has_aux(rb)) { | |
4736 | atomic_inc(&rb->aux_mmap_count); | |
4737 | ret = 0; | |
4738 | goto unlock; | |
4739 | } | |
4740 | ||
4741 | atomic_set(&rb->aux_mmap_count, 1); | |
4742 | user_extra = nr_pages; | |
4743 | ||
4744 | goto accounting; | |
4745 | } | |
7b732a75 | 4746 | |
7730d865 | 4747 | /* |
76369139 | 4748 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4749 | * can do bitmasks instead of modulo. |
4750 | */ | |
2ed11312 | 4751 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4752 | return -EINVAL; |
4753 | ||
7b732a75 | 4754 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4755 | return -EINVAL; |
4756 | ||
cdd6c482 | 4757 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4758 | again: |
cdd6c482 | 4759 | mutex_lock(&event->mmap_mutex); |
76369139 | 4760 | if (event->rb) { |
9bb5d40c | 4761 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4762 | ret = -EINVAL; |
9bb5d40c PZ |
4763 | goto unlock; |
4764 | } | |
4765 | ||
4766 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4767 | /* | |
4768 | * Raced against perf_mmap_close() through | |
4769 | * perf_event_set_output(). Try again, hope for better | |
4770 | * luck. | |
4771 | */ | |
4772 | mutex_unlock(&event->mmap_mutex); | |
4773 | goto again; | |
4774 | } | |
4775 | ||
ebb3c4c4 PZ |
4776 | goto unlock; |
4777 | } | |
4778 | ||
789f90fc | 4779 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4780 | |
4781 | accounting: | |
cdd6c482 | 4782 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4783 | |
4784 | /* | |
4785 | * Increase the limit linearly with more CPUs: | |
4786 | */ | |
4787 | user_lock_limit *= num_online_cpus(); | |
4788 | ||
789f90fc | 4789 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4790 | |
789f90fc PZ |
4791 | if (user_locked > user_lock_limit) |
4792 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4793 | |
78d7d407 | 4794 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4795 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4796 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4797 | |
459ec28a IM |
4798 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4799 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4800 | ret = -EPERM; |
4801 | goto unlock; | |
4802 | } | |
7b732a75 | 4803 | |
45bfb2e5 | 4804 | WARN_ON(!rb && event->rb); |
906010b2 | 4805 | |
d57e34fd | 4806 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4807 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4808 | |
76369139 | 4809 | if (!rb) { |
45bfb2e5 PZ |
4810 | rb = rb_alloc(nr_pages, |
4811 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4812 | event->cpu, flags); | |
26cb63ad | 4813 | |
45bfb2e5 PZ |
4814 | if (!rb) { |
4815 | ret = -ENOMEM; | |
4816 | goto unlock; | |
4817 | } | |
43a21ea8 | 4818 | |
45bfb2e5 PZ |
4819 | atomic_set(&rb->mmap_count, 1); |
4820 | rb->mmap_user = get_current_user(); | |
4821 | rb->mmap_locked = extra; | |
26cb63ad | 4822 | |
45bfb2e5 | 4823 | ring_buffer_attach(event, rb); |
ac9721f3 | 4824 | |
45bfb2e5 PZ |
4825 | perf_event_init_userpage(event); |
4826 | perf_event_update_userpage(event); | |
4827 | } else { | |
1a594131 AS |
4828 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4829 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4830 | if (!ret) |
4831 | rb->aux_mmap_locked = extra; | |
4832 | } | |
9a0f05cb | 4833 | |
ebb3c4c4 | 4834 | unlock: |
45bfb2e5 PZ |
4835 | if (!ret) { |
4836 | atomic_long_add(user_extra, &user->locked_vm); | |
4837 | vma->vm_mm->pinned_vm += extra; | |
4838 | ||
ac9721f3 | 4839 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4840 | } else if (rb) { |
4841 | atomic_dec(&rb->mmap_count); | |
4842 | } | |
4843 | aux_unlock: | |
cdd6c482 | 4844 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4845 | |
9bb5d40c PZ |
4846 | /* |
4847 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4848 | * vma. | |
4849 | */ | |
26cb63ad | 4850 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4851 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4852 | |
1e0fb9ec AL |
4853 | if (event->pmu->event_mapped) |
4854 | event->pmu->event_mapped(event); | |
4855 | ||
7b732a75 | 4856 | return ret; |
37d81828 PM |
4857 | } |
4858 | ||
3c446b3d PZ |
4859 | static int perf_fasync(int fd, struct file *filp, int on) |
4860 | { | |
496ad9aa | 4861 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4862 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4863 | int retval; |
4864 | ||
5955102c | 4865 | inode_lock(inode); |
cdd6c482 | 4866 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 4867 | inode_unlock(inode); |
3c446b3d PZ |
4868 | |
4869 | if (retval < 0) | |
4870 | return retval; | |
4871 | ||
4872 | return 0; | |
4873 | } | |
4874 | ||
0793a61d | 4875 | static const struct file_operations perf_fops = { |
3326c1ce | 4876 | .llseek = no_llseek, |
0793a61d TG |
4877 | .release = perf_release, |
4878 | .read = perf_read, | |
4879 | .poll = perf_poll, | |
d859e29f | 4880 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4881 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4882 | .mmap = perf_mmap, |
3c446b3d | 4883 | .fasync = perf_fasync, |
0793a61d TG |
4884 | }; |
4885 | ||
925d519a | 4886 | /* |
cdd6c482 | 4887 | * Perf event wakeup |
925d519a PZ |
4888 | * |
4889 | * If there's data, ensure we set the poll() state and publish everything | |
4890 | * to user-space before waking everybody up. | |
4891 | */ | |
4892 | ||
fed66e2c PZ |
4893 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4894 | { | |
4895 | /* only the parent has fasync state */ | |
4896 | if (event->parent) | |
4897 | event = event->parent; | |
4898 | return &event->fasync; | |
4899 | } | |
4900 | ||
cdd6c482 | 4901 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4902 | { |
10c6db11 | 4903 | ring_buffer_wakeup(event); |
4c9e2542 | 4904 | |
cdd6c482 | 4905 | if (event->pending_kill) { |
fed66e2c | 4906 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4907 | event->pending_kill = 0; |
4c9e2542 | 4908 | } |
925d519a PZ |
4909 | } |
4910 | ||
e360adbe | 4911 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4912 | { |
cdd6c482 IM |
4913 | struct perf_event *event = container_of(entry, |
4914 | struct perf_event, pending); | |
d525211f PZ |
4915 | int rctx; |
4916 | ||
4917 | rctx = perf_swevent_get_recursion_context(); | |
4918 | /* | |
4919 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4920 | * and we won't recurse 'further'. | |
4921 | */ | |
79f14641 | 4922 | |
cdd6c482 IM |
4923 | if (event->pending_disable) { |
4924 | event->pending_disable = 0; | |
fae3fde6 | 4925 | perf_event_disable_local(event); |
79f14641 PZ |
4926 | } |
4927 | ||
cdd6c482 IM |
4928 | if (event->pending_wakeup) { |
4929 | event->pending_wakeup = 0; | |
4930 | perf_event_wakeup(event); | |
79f14641 | 4931 | } |
d525211f PZ |
4932 | |
4933 | if (rctx >= 0) | |
4934 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4935 | } |
4936 | ||
39447b38 ZY |
4937 | /* |
4938 | * We assume there is only KVM supporting the callbacks. | |
4939 | * Later on, we might change it to a list if there is | |
4940 | * another virtualization implementation supporting the callbacks. | |
4941 | */ | |
4942 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4943 | ||
4944 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4945 | { | |
4946 | perf_guest_cbs = cbs; | |
4947 | return 0; | |
4948 | } | |
4949 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4950 | ||
4951 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4952 | { | |
4953 | perf_guest_cbs = NULL; | |
4954 | return 0; | |
4955 | } | |
4956 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4957 | ||
4018994f JO |
4958 | static void |
4959 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4960 | struct pt_regs *regs, u64 mask) | |
4961 | { | |
4962 | int bit; | |
4963 | ||
4964 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4965 | sizeof(mask) * BITS_PER_BYTE) { | |
4966 | u64 val; | |
4967 | ||
4968 | val = perf_reg_value(regs, bit); | |
4969 | perf_output_put(handle, val); | |
4970 | } | |
4971 | } | |
4972 | ||
60e2364e | 4973 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4974 | struct pt_regs *regs, |
4975 | struct pt_regs *regs_user_copy) | |
4018994f | 4976 | { |
88a7c26a AL |
4977 | if (user_mode(regs)) { |
4978 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4979 | regs_user->regs = regs; |
88a7c26a AL |
4980 | } else if (current->mm) { |
4981 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4982 | } else { |
4983 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4984 | regs_user->regs = NULL; | |
4018994f JO |
4985 | } |
4986 | } | |
4987 | ||
60e2364e SE |
4988 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
4989 | struct pt_regs *regs) | |
4990 | { | |
4991 | regs_intr->regs = regs; | |
4992 | regs_intr->abi = perf_reg_abi(current); | |
4993 | } | |
4994 | ||
4995 | ||
c5ebcedb JO |
4996 | /* |
4997 | * Get remaining task size from user stack pointer. | |
4998 | * | |
4999 | * It'd be better to take stack vma map and limit this more | |
5000 | * precisly, but there's no way to get it safely under interrupt, | |
5001 | * so using TASK_SIZE as limit. | |
5002 | */ | |
5003 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5004 | { | |
5005 | unsigned long addr = perf_user_stack_pointer(regs); | |
5006 | ||
5007 | if (!addr || addr >= TASK_SIZE) | |
5008 | return 0; | |
5009 | ||
5010 | return TASK_SIZE - addr; | |
5011 | } | |
5012 | ||
5013 | static u16 | |
5014 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5015 | struct pt_regs *regs) | |
5016 | { | |
5017 | u64 task_size; | |
5018 | ||
5019 | /* No regs, no stack pointer, no dump. */ | |
5020 | if (!regs) | |
5021 | return 0; | |
5022 | ||
5023 | /* | |
5024 | * Check if we fit in with the requested stack size into the: | |
5025 | * - TASK_SIZE | |
5026 | * If we don't, we limit the size to the TASK_SIZE. | |
5027 | * | |
5028 | * - remaining sample size | |
5029 | * If we don't, we customize the stack size to | |
5030 | * fit in to the remaining sample size. | |
5031 | */ | |
5032 | ||
5033 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5034 | stack_size = min(stack_size, (u16) task_size); | |
5035 | ||
5036 | /* Current header size plus static size and dynamic size. */ | |
5037 | header_size += 2 * sizeof(u64); | |
5038 | ||
5039 | /* Do we fit in with the current stack dump size? */ | |
5040 | if ((u16) (header_size + stack_size) < header_size) { | |
5041 | /* | |
5042 | * If we overflow the maximum size for the sample, | |
5043 | * we customize the stack dump size to fit in. | |
5044 | */ | |
5045 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5046 | stack_size = round_up(stack_size, sizeof(u64)); | |
5047 | } | |
5048 | ||
5049 | return stack_size; | |
5050 | } | |
5051 | ||
5052 | static void | |
5053 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5054 | struct pt_regs *regs) | |
5055 | { | |
5056 | /* Case of a kernel thread, nothing to dump */ | |
5057 | if (!regs) { | |
5058 | u64 size = 0; | |
5059 | perf_output_put(handle, size); | |
5060 | } else { | |
5061 | unsigned long sp; | |
5062 | unsigned int rem; | |
5063 | u64 dyn_size; | |
5064 | ||
5065 | /* | |
5066 | * We dump: | |
5067 | * static size | |
5068 | * - the size requested by user or the best one we can fit | |
5069 | * in to the sample max size | |
5070 | * data | |
5071 | * - user stack dump data | |
5072 | * dynamic size | |
5073 | * - the actual dumped size | |
5074 | */ | |
5075 | ||
5076 | /* Static size. */ | |
5077 | perf_output_put(handle, dump_size); | |
5078 | ||
5079 | /* Data. */ | |
5080 | sp = perf_user_stack_pointer(regs); | |
5081 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5082 | dyn_size = dump_size - rem; | |
5083 | ||
5084 | perf_output_skip(handle, rem); | |
5085 | ||
5086 | /* Dynamic size. */ | |
5087 | perf_output_put(handle, dyn_size); | |
5088 | } | |
5089 | } | |
5090 | ||
c980d109 ACM |
5091 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5092 | struct perf_sample_data *data, | |
5093 | struct perf_event *event) | |
6844c09d ACM |
5094 | { |
5095 | u64 sample_type = event->attr.sample_type; | |
5096 | ||
5097 | data->type = sample_type; | |
5098 | header->size += event->id_header_size; | |
5099 | ||
5100 | if (sample_type & PERF_SAMPLE_TID) { | |
5101 | /* namespace issues */ | |
5102 | data->tid_entry.pid = perf_event_pid(event, current); | |
5103 | data->tid_entry.tid = perf_event_tid(event, current); | |
5104 | } | |
5105 | ||
5106 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5107 | data->time = perf_event_clock(event); |
6844c09d | 5108 | |
ff3d527c | 5109 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5110 | data->id = primary_event_id(event); |
5111 | ||
5112 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5113 | data->stream_id = event->id; | |
5114 | ||
5115 | if (sample_type & PERF_SAMPLE_CPU) { | |
5116 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5117 | data->cpu_entry.reserved = 0; | |
5118 | } | |
5119 | } | |
5120 | ||
76369139 FW |
5121 | void perf_event_header__init_id(struct perf_event_header *header, |
5122 | struct perf_sample_data *data, | |
5123 | struct perf_event *event) | |
c980d109 ACM |
5124 | { |
5125 | if (event->attr.sample_id_all) | |
5126 | __perf_event_header__init_id(header, data, event); | |
5127 | } | |
5128 | ||
5129 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5130 | struct perf_sample_data *data) | |
5131 | { | |
5132 | u64 sample_type = data->type; | |
5133 | ||
5134 | if (sample_type & PERF_SAMPLE_TID) | |
5135 | perf_output_put(handle, data->tid_entry); | |
5136 | ||
5137 | if (sample_type & PERF_SAMPLE_TIME) | |
5138 | perf_output_put(handle, data->time); | |
5139 | ||
5140 | if (sample_type & PERF_SAMPLE_ID) | |
5141 | perf_output_put(handle, data->id); | |
5142 | ||
5143 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5144 | perf_output_put(handle, data->stream_id); | |
5145 | ||
5146 | if (sample_type & PERF_SAMPLE_CPU) | |
5147 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5148 | |
5149 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5150 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5151 | } |
5152 | ||
76369139 FW |
5153 | void perf_event__output_id_sample(struct perf_event *event, |
5154 | struct perf_output_handle *handle, | |
5155 | struct perf_sample_data *sample) | |
c980d109 ACM |
5156 | { |
5157 | if (event->attr.sample_id_all) | |
5158 | __perf_event__output_id_sample(handle, sample); | |
5159 | } | |
5160 | ||
3dab77fb | 5161 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5162 | struct perf_event *event, |
5163 | u64 enabled, u64 running) | |
3dab77fb | 5164 | { |
cdd6c482 | 5165 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5166 | u64 values[4]; |
5167 | int n = 0; | |
5168 | ||
b5e58793 | 5169 | values[n++] = perf_event_count(event); |
3dab77fb | 5170 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5171 | values[n++] = enabled + |
cdd6c482 | 5172 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5173 | } |
5174 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5175 | values[n++] = running + |
cdd6c482 | 5176 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5177 | } |
5178 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5179 | values[n++] = primary_event_id(event); |
3dab77fb | 5180 | |
76369139 | 5181 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5182 | } |
5183 | ||
5184 | /* | |
cdd6c482 | 5185 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5186 | */ |
5187 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5188 | struct perf_event *event, |
5189 | u64 enabled, u64 running) | |
3dab77fb | 5190 | { |
cdd6c482 IM |
5191 | struct perf_event *leader = event->group_leader, *sub; |
5192 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5193 | u64 values[5]; |
5194 | int n = 0; | |
5195 | ||
5196 | values[n++] = 1 + leader->nr_siblings; | |
5197 | ||
5198 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5199 | values[n++] = enabled; |
3dab77fb PZ |
5200 | |
5201 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5202 | values[n++] = running; |
3dab77fb | 5203 | |
cdd6c482 | 5204 | if (leader != event) |
3dab77fb PZ |
5205 | leader->pmu->read(leader); |
5206 | ||
b5e58793 | 5207 | values[n++] = perf_event_count(leader); |
3dab77fb | 5208 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5209 | values[n++] = primary_event_id(leader); |
3dab77fb | 5210 | |
76369139 | 5211 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5212 | |
65abc865 | 5213 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5214 | n = 0; |
5215 | ||
6f5ab001 JO |
5216 | if ((sub != event) && |
5217 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5218 | sub->pmu->read(sub); |
5219 | ||
b5e58793 | 5220 | values[n++] = perf_event_count(sub); |
3dab77fb | 5221 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5222 | values[n++] = primary_event_id(sub); |
3dab77fb | 5223 | |
76369139 | 5224 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5225 | } |
5226 | } | |
5227 | ||
eed01528 SE |
5228 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5229 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5230 | ||
3dab77fb | 5231 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5232 | struct perf_event *event) |
3dab77fb | 5233 | { |
e3f3541c | 5234 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5235 | u64 read_format = event->attr.read_format; |
5236 | ||
5237 | /* | |
5238 | * compute total_time_enabled, total_time_running | |
5239 | * based on snapshot values taken when the event | |
5240 | * was last scheduled in. | |
5241 | * | |
5242 | * we cannot simply called update_context_time() | |
5243 | * because of locking issue as we are called in | |
5244 | * NMI context | |
5245 | */ | |
c4794295 | 5246 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5247 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5248 | |
cdd6c482 | 5249 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5250 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5251 | else |
eed01528 | 5252 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5253 | } |
5254 | ||
5622f295 MM |
5255 | void perf_output_sample(struct perf_output_handle *handle, |
5256 | struct perf_event_header *header, | |
5257 | struct perf_sample_data *data, | |
cdd6c482 | 5258 | struct perf_event *event) |
5622f295 MM |
5259 | { |
5260 | u64 sample_type = data->type; | |
5261 | ||
5262 | perf_output_put(handle, *header); | |
5263 | ||
ff3d527c AH |
5264 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5265 | perf_output_put(handle, data->id); | |
5266 | ||
5622f295 MM |
5267 | if (sample_type & PERF_SAMPLE_IP) |
5268 | perf_output_put(handle, data->ip); | |
5269 | ||
5270 | if (sample_type & PERF_SAMPLE_TID) | |
5271 | perf_output_put(handle, data->tid_entry); | |
5272 | ||
5273 | if (sample_type & PERF_SAMPLE_TIME) | |
5274 | perf_output_put(handle, data->time); | |
5275 | ||
5276 | if (sample_type & PERF_SAMPLE_ADDR) | |
5277 | perf_output_put(handle, data->addr); | |
5278 | ||
5279 | if (sample_type & PERF_SAMPLE_ID) | |
5280 | perf_output_put(handle, data->id); | |
5281 | ||
5282 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5283 | perf_output_put(handle, data->stream_id); | |
5284 | ||
5285 | if (sample_type & PERF_SAMPLE_CPU) | |
5286 | perf_output_put(handle, data->cpu_entry); | |
5287 | ||
5288 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5289 | perf_output_put(handle, data->period); | |
5290 | ||
5291 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5292 | perf_output_read(handle, event); |
5622f295 MM |
5293 | |
5294 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5295 | if (data->callchain) { | |
5296 | int size = 1; | |
5297 | ||
5298 | if (data->callchain) | |
5299 | size += data->callchain->nr; | |
5300 | ||
5301 | size *= sizeof(u64); | |
5302 | ||
76369139 | 5303 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5304 | } else { |
5305 | u64 nr = 0; | |
5306 | perf_output_put(handle, nr); | |
5307 | } | |
5308 | } | |
5309 | ||
5310 | if (sample_type & PERF_SAMPLE_RAW) { | |
5311 | if (data->raw) { | |
fa128e6a AS |
5312 | u32 raw_size = data->raw->size; |
5313 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5314 | sizeof(u64)) - sizeof(u32); | |
5315 | u64 zero = 0; | |
5316 | ||
5317 | perf_output_put(handle, real_size); | |
5318 | __output_copy(handle, data->raw->data, raw_size); | |
5319 | if (real_size - raw_size) | |
5320 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5321 | } else { |
5322 | struct { | |
5323 | u32 size; | |
5324 | u32 data; | |
5325 | } raw = { | |
5326 | .size = sizeof(u32), | |
5327 | .data = 0, | |
5328 | }; | |
5329 | perf_output_put(handle, raw); | |
5330 | } | |
5331 | } | |
a7ac67ea | 5332 | |
bce38cd5 SE |
5333 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5334 | if (data->br_stack) { | |
5335 | size_t size; | |
5336 | ||
5337 | size = data->br_stack->nr | |
5338 | * sizeof(struct perf_branch_entry); | |
5339 | ||
5340 | perf_output_put(handle, data->br_stack->nr); | |
5341 | perf_output_copy(handle, data->br_stack->entries, size); | |
5342 | } else { | |
5343 | /* | |
5344 | * we always store at least the value of nr | |
5345 | */ | |
5346 | u64 nr = 0; | |
5347 | perf_output_put(handle, nr); | |
5348 | } | |
5349 | } | |
4018994f JO |
5350 | |
5351 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5352 | u64 abi = data->regs_user.abi; | |
5353 | ||
5354 | /* | |
5355 | * If there are no regs to dump, notice it through | |
5356 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5357 | */ | |
5358 | perf_output_put(handle, abi); | |
5359 | ||
5360 | if (abi) { | |
5361 | u64 mask = event->attr.sample_regs_user; | |
5362 | perf_output_sample_regs(handle, | |
5363 | data->regs_user.regs, | |
5364 | mask); | |
5365 | } | |
5366 | } | |
c5ebcedb | 5367 | |
a5cdd40c | 5368 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5369 | perf_output_sample_ustack(handle, |
5370 | data->stack_user_size, | |
5371 | data->regs_user.regs); | |
a5cdd40c | 5372 | } |
c3feedf2 AK |
5373 | |
5374 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5375 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5376 | |
5377 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5378 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5379 | |
fdfbbd07 AK |
5380 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5381 | perf_output_put(handle, data->txn); | |
5382 | ||
60e2364e SE |
5383 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5384 | u64 abi = data->regs_intr.abi; | |
5385 | /* | |
5386 | * If there are no regs to dump, notice it through | |
5387 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5388 | */ | |
5389 | perf_output_put(handle, abi); | |
5390 | ||
5391 | if (abi) { | |
5392 | u64 mask = event->attr.sample_regs_intr; | |
5393 | ||
5394 | perf_output_sample_regs(handle, | |
5395 | data->regs_intr.regs, | |
5396 | mask); | |
5397 | } | |
5398 | } | |
5399 | ||
a5cdd40c PZ |
5400 | if (!event->attr.watermark) { |
5401 | int wakeup_events = event->attr.wakeup_events; | |
5402 | ||
5403 | if (wakeup_events) { | |
5404 | struct ring_buffer *rb = handle->rb; | |
5405 | int events = local_inc_return(&rb->events); | |
5406 | ||
5407 | if (events >= wakeup_events) { | |
5408 | local_sub(wakeup_events, &rb->events); | |
5409 | local_inc(&rb->wakeup); | |
5410 | } | |
5411 | } | |
5412 | } | |
5622f295 MM |
5413 | } |
5414 | ||
5415 | void perf_prepare_sample(struct perf_event_header *header, | |
5416 | struct perf_sample_data *data, | |
cdd6c482 | 5417 | struct perf_event *event, |
5622f295 | 5418 | struct pt_regs *regs) |
7b732a75 | 5419 | { |
cdd6c482 | 5420 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5421 | |
cdd6c482 | 5422 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5423 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5424 | |
5425 | header->misc = 0; | |
5426 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5427 | |
c980d109 | 5428 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5429 | |
c320c7b7 | 5430 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5431 | data->ip = perf_instruction_pointer(regs); |
5432 | ||
b23f3325 | 5433 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5434 | int size = 1; |
394ee076 | 5435 | |
e6dab5ff | 5436 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5437 | |
5438 | if (data->callchain) | |
5439 | size += data->callchain->nr; | |
5440 | ||
5441 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5442 | } |
5443 | ||
3a43ce68 | 5444 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5445 | int size = sizeof(u32); |
5446 | ||
5447 | if (data->raw) | |
5448 | size += data->raw->size; | |
5449 | else | |
5450 | size += sizeof(u32); | |
5451 | ||
fa128e6a | 5452 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5453 | } |
bce38cd5 SE |
5454 | |
5455 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5456 | int size = sizeof(u64); /* nr */ | |
5457 | if (data->br_stack) { | |
5458 | size += data->br_stack->nr | |
5459 | * sizeof(struct perf_branch_entry); | |
5460 | } | |
5461 | header->size += size; | |
5462 | } | |
4018994f | 5463 | |
2565711f | 5464 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5465 | perf_sample_regs_user(&data->regs_user, regs, |
5466 | &data->regs_user_copy); | |
2565711f | 5467 | |
4018994f JO |
5468 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5469 | /* regs dump ABI info */ | |
5470 | int size = sizeof(u64); | |
5471 | ||
4018994f JO |
5472 | if (data->regs_user.regs) { |
5473 | u64 mask = event->attr.sample_regs_user; | |
5474 | size += hweight64(mask) * sizeof(u64); | |
5475 | } | |
5476 | ||
5477 | header->size += size; | |
5478 | } | |
c5ebcedb JO |
5479 | |
5480 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5481 | /* | |
5482 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5483 | * processed as the last one or have additional check added | |
5484 | * in case new sample type is added, because we could eat | |
5485 | * up the rest of the sample size. | |
5486 | */ | |
c5ebcedb JO |
5487 | u16 stack_size = event->attr.sample_stack_user; |
5488 | u16 size = sizeof(u64); | |
5489 | ||
c5ebcedb | 5490 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5491 | data->regs_user.regs); |
c5ebcedb JO |
5492 | |
5493 | /* | |
5494 | * If there is something to dump, add space for the dump | |
5495 | * itself and for the field that tells the dynamic size, | |
5496 | * which is how many have been actually dumped. | |
5497 | */ | |
5498 | if (stack_size) | |
5499 | size += sizeof(u64) + stack_size; | |
5500 | ||
5501 | data->stack_user_size = stack_size; | |
5502 | header->size += size; | |
5503 | } | |
60e2364e SE |
5504 | |
5505 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5506 | /* regs dump ABI info */ | |
5507 | int size = sizeof(u64); | |
5508 | ||
5509 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5510 | ||
5511 | if (data->regs_intr.regs) { | |
5512 | u64 mask = event->attr.sample_regs_intr; | |
5513 | ||
5514 | size += hweight64(mask) * sizeof(u64); | |
5515 | } | |
5516 | ||
5517 | header->size += size; | |
5518 | } | |
5622f295 | 5519 | } |
7f453c24 | 5520 | |
21509084 YZ |
5521 | void perf_event_output(struct perf_event *event, |
5522 | struct perf_sample_data *data, | |
5523 | struct pt_regs *regs) | |
5622f295 MM |
5524 | { |
5525 | struct perf_output_handle handle; | |
5526 | struct perf_event_header header; | |
689802b2 | 5527 | |
927c7a9e FW |
5528 | /* protect the callchain buffers */ |
5529 | rcu_read_lock(); | |
5530 | ||
cdd6c482 | 5531 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5532 | |
a7ac67ea | 5533 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5534 | goto exit; |
0322cd6e | 5535 | |
cdd6c482 | 5536 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5537 | |
8a057d84 | 5538 | perf_output_end(&handle); |
927c7a9e FW |
5539 | |
5540 | exit: | |
5541 | rcu_read_unlock(); | |
0322cd6e PZ |
5542 | } |
5543 | ||
38b200d6 | 5544 | /* |
cdd6c482 | 5545 | * read event_id |
38b200d6 PZ |
5546 | */ |
5547 | ||
5548 | struct perf_read_event { | |
5549 | struct perf_event_header header; | |
5550 | ||
5551 | u32 pid; | |
5552 | u32 tid; | |
38b200d6 PZ |
5553 | }; |
5554 | ||
5555 | static void | |
cdd6c482 | 5556 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5557 | struct task_struct *task) |
5558 | { | |
5559 | struct perf_output_handle handle; | |
c980d109 | 5560 | struct perf_sample_data sample; |
dfc65094 | 5561 | struct perf_read_event read_event = { |
38b200d6 | 5562 | .header = { |
cdd6c482 | 5563 | .type = PERF_RECORD_READ, |
38b200d6 | 5564 | .misc = 0, |
c320c7b7 | 5565 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5566 | }, |
cdd6c482 IM |
5567 | .pid = perf_event_pid(event, task), |
5568 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5569 | }; |
3dab77fb | 5570 | int ret; |
38b200d6 | 5571 | |
c980d109 | 5572 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5573 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5574 | if (ret) |
5575 | return; | |
5576 | ||
dfc65094 | 5577 | perf_output_put(&handle, read_event); |
cdd6c482 | 5578 | perf_output_read(&handle, event); |
c980d109 | 5579 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5580 | |
38b200d6 PZ |
5581 | perf_output_end(&handle); |
5582 | } | |
5583 | ||
52d857a8 JO |
5584 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5585 | ||
5586 | static void | |
5587 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5588 | perf_event_aux_output_cb output, |
5589 | void *data) | |
5590 | { | |
5591 | struct perf_event *event; | |
5592 | ||
5593 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5594 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5595 | continue; | |
5596 | if (!event_filter_match(event)) | |
5597 | continue; | |
67516844 | 5598 | output(event, data); |
52d857a8 JO |
5599 | } |
5600 | } | |
5601 | ||
4e93ad60 JO |
5602 | static void |
5603 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5604 | struct perf_event_context *task_ctx) | |
5605 | { | |
5606 | rcu_read_lock(); | |
5607 | preempt_disable(); | |
5608 | perf_event_aux_ctx(task_ctx, output, data); | |
5609 | preempt_enable(); | |
5610 | rcu_read_unlock(); | |
5611 | } | |
5612 | ||
52d857a8 | 5613 | static void |
67516844 | 5614 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5615 | struct perf_event_context *task_ctx) |
5616 | { | |
5617 | struct perf_cpu_context *cpuctx; | |
5618 | struct perf_event_context *ctx; | |
5619 | struct pmu *pmu; | |
5620 | int ctxn; | |
5621 | ||
4e93ad60 JO |
5622 | /* |
5623 | * If we have task_ctx != NULL we only notify | |
5624 | * the task context itself. The task_ctx is set | |
5625 | * only for EXIT events before releasing task | |
5626 | * context. | |
5627 | */ | |
5628 | if (task_ctx) { | |
5629 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5630 | return; | |
5631 | } | |
5632 | ||
52d857a8 JO |
5633 | rcu_read_lock(); |
5634 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5635 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5636 | if (cpuctx->unique_pmu != pmu) | |
5637 | goto next; | |
67516844 | 5638 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5639 | ctxn = pmu->task_ctx_nr; |
5640 | if (ctxn < 0) | |
5641 | goto next; | |
5642 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5643 | if (ctx) | |
67516844 | 5644 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5645 | next: |
5646 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5647 | } | |
52d857a8 JO |
5648 | rcu_read_unlock(); |
5649 | } | |
5650 | ||
60313ebe | 5651 | /* |
9f498cc5 PZ |
5652 | * task tracking -- fork/exit |
5653 | * | |
13d7a241 | 5654 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5655 | */ |
5656 | ||
9f498cc5 | 5657 | struct perf_task_event { |
3a80b4a3 | 5658 | struct task_struct *task; |
cdd6c482 | 5659 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5660 | |
5661 | struct { | |
5662 | struct perf_event_header header; | |
5663 | ||
5664 | u32 pid; | |
5665 | u32 ppid; | |
9f498cc5 PZ |
5666 | u32 tid; |
5667 | u32 ptid; | |
393b2ad8 | 5668 | u64 time; |
cdd6c482 | 5669 | } event_id; |
60313ebe PZ |
5670 | }; |
5671 | ||
67516844 JO |
5672 | static int perf_event_task_match(struct perf_event *event) |
5673 | { | |
13d7a241 SE |
5674 | return event->attr.comm || event->attr.mmap || |
5675 | event->attr.mmap2 || event->attr.mmap_data || | |
5676 | event->attr.task; | |
67516844 JO |
5677 | } |
5678 | ||
cdd6c482 | 5679 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5680 | void *data) |
60313ebe | 5681 | { |
52d857a8 | 5682 | struct perf_task_event *task_event = data; |
60313ebe | 5683 | struct perf_output_handle handle; |
c980d109 | 5684 | struct perf_sample_data sample; |
9f498cc5 | 5685 | struct task_struct *task = task_event->task; |
c980d109 | 5686 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5687 | |
67516844 JO |
5688 | if (!perf_event_task_match(event)) |
5689 | return; | |
5690 | ||
c980d109 | 5691 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5692 | |
c980d109 | 5693 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5694 | task_event->event_id.header.size); |
ef60777c | 5695 | if (ret) |
c980d109 | 5696 | goto out; |
60313ebe | 5697 | |
cdd6c482 IM |
5698 | task_event->event_id.pid = perf_event_pid(event, task); |
5699 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5700 | |
cdd6c482 IM |
5701 | task_event->event_id.tid = perf_event_tid(event, task); |
5702 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5703 | |
34f43927 PZ |
5704 | task_event->event_id.time = perf_event_clock(event); |
5705 | ||
cdd6c482 | 5706 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5707 | |
c980d109 ACM |
5708 | perf_event__output_id_sample(event, &handle, &sample); |
5709 | ||
60313ebe | 5710 | perf_output_end(&handle); |
c980d109 ACM |
5711 | out: |
5712 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5713 | } |
5714 | ||
cdd6c482 IM |
5715 | static void perf_event_task(struct task_struct *task, |
5716 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5717 | int new) |
60313ebe | 5718 | { |
9f498cc5 | 5719 | struct perf_task_event task_event; |
60313ebe | 5720 | |
cdd6c482 IM |
5721 | if (!atomic_read(&nr_comm_events) && |
5722 | !atomic_read(&nr_mmap_events) && | |
5723 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5724 | return; |
5725 | ||
9f498cc5 | 5726 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5727 | .task = task, |
5728 | .task_ctx = task_ctx, | |
cdd6c482 | 5729 | .event_id = { |
60313ebe | 5730 | .header = { |
cdd6c482 | 5731 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5732 | .misc = 0, |
cdd6c482 | 5733 | .size = sizeof(task_event.event_id), |
60313ebe | 5734 | }, |
573402db PZ |
5735 | /* .pid */ |
5736 | /* .ppid */ | |
9f498cc5 PZ |
5737 | /* .tid */ |
5738 | /* .ptid */ | |
34f43927 | 5739 | /* .time */ |
60313ebe PZ |
5740 | }, |
5741 | }; | |
5742 | ||
67516844 | 5743 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5744 | &task_event, |
5745 | task_ctx); | |
9f498cc5 PZ |
5746 | } |
5747 | ||
cdd6c482 | 5748 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5749 | { |
cdd6c482 | 5750 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5751 | } |
5752 | ||
8d1b2d93 PZ |
5753 | /* |
5754 | * comm tracking | |
5755 | */ | |
5756 | ||
5757 | struct perf_comm_event { | |
22a4f650 IM |
5758 | struct task_struct *task; |
5759 | char *comm; | |
8d1b2d93 PZ |
5760 | int comm_size; |
5761 | ||
5762 | struct { | |
5763 | struct perf_event_header header; | |
5764 | ||
5765 | u32 pid; | |
5766 | u32 tid; | |
cdd6c482 | 5767 | } event_id; |
8d1b2d93 PZ |
5768 | }; |
5769 | ||
67516844 JO |
5770 | static int perf_event_comm_match(struct perf_event *event) |
5771 | { | |
5772 | return event->attr.comm; | |
5773 | } | |
5774 | ||
cdd6c482 | 5775 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5776 | void *data) |
8d1b2d93 | 5777 | { |
52d857a8 | 5778 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5779 | struct perf_output_handle handle; |
c980d109 | 5780 | struct perf_sample_data sample; |
cdd6c482 | 5781 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5782 | int ret; |
5783 | ||
67516844 JO |
5784 | if (!perf_event_comm_match(event)) |
5785 | return; | |
5786 | ||
c980d109 ACM |
5787 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5788 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5789 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5790 | |
5791 | if (ret) | |
c980d109 | 5792 | goto out; |
8d1b2d93 | 5793 | |
cdd6c482 IM |
5794 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5795 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5796 | |
cdd6c482 | 5797 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5798 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5799 | comm_event->comm_size); |
c980d109 ACM |
5800 | |
5801 | perf_event__output_id_sample(event, &handle, &sample); | |
5802 | ||
8d1b2d93 | 5803 | perf_output_end(&handle); |
c980d109 ACM |
5804 | out: |
5805 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5806 | } |
5807 | ||
cdd6c482 | 5808 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5809 | { |
413ee3b4 | 5810 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5811 | unsigned int size; |
8d1b2d93 | 5812 | |
413ee3b4 | 5813 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5814 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5815 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5816 | |
5817 | comm_event->comm = comm; | |
5818 | comm_event->comm_size = size; | |
5819 | ||
cdd6c482 | 5820 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5821 | |
67516844 | 5822 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5823 | comm_event, |
5824 | NULL); | |
8d1b2d93 PZ |
5825 | } |
5826 | ||
82b89778 | 5827 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5828 | { |
9ee318a7 PZ |
5829 | struct perf_comm_event comm_event; |
5830 | ||
cdd6c482 | 5831 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5832 | return; |
a63eaf34 | 5833 | |
9ee318a7 | 5834 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5835 | .task = task, |
573402db PZ |
5836 | /* .comm */ |
5837 | /* .comm_size */ | |
cdd6c482 | 5838 | .event_id = { |
573402db | 5839 | .header = { |
cdd6c482 | 5840 | .type = PERF_RECORD_COMM, |
82b89778 | 5841 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5842 | /* .size */ |
5843 | }, | |
5844 | /* .pid */ | |
5845 | /* .tid */ | |
8d1b2d93 PZ |
5846 | }, |
5847 | }; | |
5848 | ||
cdd6c482 | 5849 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5850 | } |
5851 | ||
0a4a9391 PZ |
5852 | /* |
5853 | * mmap tracking | |
5854 | */ | |
5855 | ||
5856 | struct perf_mmap_event { | |
089dd79d PZ |
5857 | struct vm_area_struct *vma; |
5858 | ||
5859 | const char *file_name; | |
5860 | int file_size; | |
13d7a241 SE |
5861 | int maj, min; |
5862 | u64 ino; | |
5863 | u64 ino_generation; | |
f972eb63 | 5864 | u32 prot, flags; |
0a4a9391 PZ |
5865 | |
5866 | struct { | |
5867 | struct perf_event_header header; | |
5868 | ||
5869 | u32 pid; | |
5870 | u32 tid; | |
5871 | u64 start; | |
5872 | u64 len; | |
5873 | u64 pgoff; | |
cdd6c482 | 5874 | } event_id; |
0a4a9391 PZ |
5875 | }; |
5876 | ||
67516844 JO |
5877 | static int perf_event_mmap_match(struct perf_event *event, |
5878 | void *data) | |
5879 | { | |
5880 | struct perf_mmap_event *mmap_event = data; | |
5881 | struct vm_area_struct *vma = mmap_event->vma; | |
5882 | int executable = vma->vm_flags & VM_EXEC; | |
5883 | ||
5884 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5885 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5886 | } |
5887 | ||
cdd6c482 | 5888 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5889 | void *data) |
0a4a9391 | 5890 | { |
52d857a8 | 5891 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5892 | struct perf_output_handle handle; |
c980d109 | 5893 | struct perf_sample_data sample; |
cdd6c482 | 5894 | int size = mmap_event->event_id.header.size; |
c980d109 | 5895 | int ret; |
0a4a9391 | 5896 | |
67516844 JO |
5897 | if (!perf_event_mmap_match(event, data)) |
5898 | return; | |
5899 | ||
13d7a241 SE |
5900 | if (event->attr.mmap2) { |
5901 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5902 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5903 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5904 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5905 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5906 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5907 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5908 | } |
5909 | ||
c980d109 ACM |
5910 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5911 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5912 | mmap_event->event_id.header.size); |
0a4a9391 | 5913 | if (ret) |
c980d109 | 5914 | goto out; |
0a4a9391 | 5915 | |
cdd6c482 IM |
5916 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5917 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5918 | |
cdd6c482 | 5919 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5920 | |
5921 | if (event->attr.mmap2) { | |
5922 | perf_output_put(&handle, mmap_event->maj); | |
5923 | perf_output_put(&handle, mmap_event->min); | |
5924 | perf_output_put(&handle, mmap_event->ino); | |
5925 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5926 | perf_output_put(&handle, mmap_event->prot); |
5927 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5928 | } |
5929 | ||
76369139 | 5930 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5931 | mmap_event->file_size); |
c980d109 ACM |
5932 | |
5933 | perf_event__output_id_sample(event, &handle, &sample); | |
5934 | ||
78d613eb | 5935 | perf_output_end(&handle); |
c980d109 ACM |
5936 | out: |
5937 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5938 | } |
5939 | ||
cdd6c482 | 5940 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5941 | { |
089dd79d PZ |
5942 | struct vm_area_struct *vma = mmap_event->vma; |
5943 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5944 | int maj = 0, min = 0; |
5945 | u64 ino = 0, gen = 0; | |
f972eb63 | 5946 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5947 | unsigned int size; |
5948 | char tmp[16]; | |
5949 | char *buf = NULL; | |
2c42cfbf | 5950 | char *name; |
413ee3b4 | 5951 | |
0a4a9391 | 5952 | if (file) { |
13d7a241 SE |
5953 | struct inode *inode; |
5954 | dev_t dev; | |
3ea2f2b9 | 5955 | |
2c42cfbf | 5956 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5957 | if (!buf) { |
c7e548b4 ON |
5958 | name = "//enomem"; |
5959 | goto cpy_name; | |
0a4a9391 | 5960 | } |
413ee3b4 | 5961 | /* |
3ea2f2b9 | 5962 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5963 | * need to add enough zero bytes after the string to handle |
5964 | * the 64bit alignment we do later. | |
5965 | */ | |
9bf39ab2 | 5966 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5967 | if (IS_ERR(name)) { |
c7e548b4 ON |
5968 | name = "//toolong"; |
5969 | goto cpy_name; | |
0a4a9391 | 5970 | } |
13d7a241 SE |
5971 | inode = file_inode(vma->vm_file); |
5972 | dev = inode->i_sb->s_dev; | |
5973 | ino = inode->i_ino; | |
5974 | gen = inode->i_generation; | |
5975 | maj = MAJOR(dev); | |
5976 | min = MINOR(dev); | |
f972eb63 PZ |
5977 | |
5978 | if (vma->vm_flags & VM_READ) | |
5979 | prot |= PROT_READ; | |
5980 | if (vma->vm_flags & VM_WRITE) | |
5981 | prot |= PROT_WRITE; | |
5982 | if (vma->vm_flags & VM_EXEC) | |
5983 | prot |= PROT_EXEC; | |
5984 | ||
5985 | if (vma->vm_flags & VM_MAYSHARE) | |
5986 | flags = MAP_SHARED; | |
5987 | else | |
5988 | flags = MAP_PRIVATE; | |
5989 | ||
5990 | if (vma->vm_flags & VM_DENYWRITE) | |
5991 | flags |= MAP_DENYWRITE; | |
5992 | if (vma->vm_flags & VM_MAYEXEC) | |
5993 | flags |= MAP_EXECUTABLE; | |
5994 | if (vma->vm_flags & VM_LOCKED) | |
5995 | flags |= MAP_LOCKED; | |
5996 | if (vma->vm_flags & VM_HUGETLB) | |
5997 | flags |= MAP_HUGETLB; | |
5998 | ||
c7e548b4 | 5999 | goto got_name; |
0a4a9391 | 6000 | } else { |
fbe26abe JO |
6001 | if (vma->vm_ops && vma->vm_ops->name) { |
6002 | name = (char *) vma->vm_ops->name(vma); | |
6003 | if (name) | |
6004 | goto cpy_name; | |
6005 | } | |
6006 | ||
2c42cfbf | 6007 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6008 | if (name) |
6009 | goto cpy_name; | |
089dd79d | 6010 | |
32c5fb7e | 6011 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6012 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6013 | name = "[heap]"; |
6014 | goto cpy_name; | |
32c5fb7e ON |
6015 | } |
6016 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6017 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6018 | name = "[stack]"; |
6019 | goto cpy_name; | |
089dd79d PZ |
6020 | } |
6021 | ||
c7e548b4 ON |
6022 | name = "//anon"; |
6023 | goto cpy_name; | |
0a4a9391 PZ |
6024 | } |
6025 | ||
c7e548b4 ON |
6026 | cpy_name: |
6027 | strlcpy(tmp, name, sizeof(tmp)); | |
6028 | name = tmp; | |
0a4a9391 | 6029 | got_name: |
2c42cfbf PZ |
6030 | /* |
6031 | * Since our buffer works in 8 byte units we need to align our string | |
6032 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6033 | * zero'd out to avoid leaking random bits to userspace. | |
6034 | */ | |
6035 | size = strlen(name)+1; | |
6036 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6037 | name[size++] = '\0'; | |
0a4a9391 PZ |
6038 | |
6039 | mmap_event->file_name = name; | |
6040 | mmap_event->file_size = size; | |
13d7a241 SE |
6041 | mmap_event->maj = maj; |
6042 | mmap_event->min = min; | |
6043 | mmap_event->ino = ino; | |
6044 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6045 | mmap_event->prot = prot; |
6046 | mmap_event->flags = flags; | |
0a4a9391 | 6047 | |
2fe85427 SE |
6048 | if (!(vma->vm_flags & VM_EXEC)) |
6049 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6050 | ||
cdd6c482 | 6051 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6052 | |
67516844 | 6053 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6054 | mmap_event, |
6055 | NULL); | |
665c2142 | 6056 | |
0a4a9391 PZ |
6057 | kfree(buf); |
6058 | } | |
6059 | ||
3af9e859 | 6060 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6061 | { |
9ee318a7 PZ |
6062 | struct perf_mmap_event mmap_event; |
6063 | ||
cdd6c482 | 6064 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6065 | return; |
6066 | ||
6067 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6068 | .vma = vma, |
573402db PZ |
6069 | /* .file_name */ |
6070 | /* .file_size */ | |
cdd6c482 | 6071 | .event_id = { |
573402db | 6072 | .header = { |
cdd6c482 | 6073 | .type = PERF_RECORD_MMAP, |
39447b38 | 6074 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6075 | /* .size */ |
6076 | }, | |
6077 | /* .pid */ | |
6078 | /* .tid */ | |
089dd79d PZ |
6079 | .start = vma->vm_start, |
6080 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6081 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6082 | }, |
13d7a241 SE |
6083 | /* .maj (attr_mmap2 only) */ |
6084 | /* .min (attr_mmap2 only) */ | |
6085 | /* .ino (attr_mmap2 only) */ | |
6086 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6087 | /* .prot (attr_mmap2 only) */ |
6088 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6089 | }; |
6090 | ||
cdd6c482 | 6091 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6092 | } |
6093 | ||
68db7e98 AS |
6094 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6095 | unsigned long size, u64 flags) | |
6096 | { | |
6097 | struct perf_output_handle handle; | |
6098 | struct perf_sample_data sample; | |
6099 | struct perf_aux_event { | |
6100 | struct perf_event_header header; | |
6101 | u64 offset; | |
6102 | u64 size; | |
6103 | u64 flags; | |
6104 | } rec = { | |
6105 | .header = { | |
6106 | .type = PERF_RECORD_AUX, | |
6107 | .misc = 0, | |
6108 | .size = sizeof(rec), | |
6109 | }, | |
6110 | .offset = head, | |
6111 | .size = size, | |
6112 | .flags = flags, | |
6113 | }; | |
6114 | int ret; | |
6115 | ||
6116 | perf_event_header__init_id(&rec.header, &sample, event); | |
6117 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6118 | ||
6119 | if (ret) | |
6120 | return; | |
6121 | ||
6122 | perf_output_put(&handle, rec); | |
6123 | perf_event__output_id_sample(event, &handle, &sample); | |
6124 | ||
6125 | perf_output_end(&handle); | |
6126 | } | |
6127 | ||
f38b0dbb KL |
6128 | /* |
6129 | * Lost/dropped samples logging | |
6130 | */ | |
6131 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6132 | { | |
6133 | struct perf_output_handle handle; | |
6134 | struct perf_sample_data sample; | |
6135 | int ret; | |
6136 | ||
6137 | struct { | |
6138 | struct perf_event_header header; | |
6139 | u64 lost; | |
6140 | } lost_samples_event = { | |
6141 | .header = { | |
6142 | .type = PERF_RECORD_LOST_SAMPLES, | |
6143 | .misc = 0, | |
6144 | .size = sizeof(lost_samples_event), | |
6145 | }, | |
6146 | .lost = lost, | |
6147 | }; | |
6148 | ||
6149 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6150 | ||
6151 | ret = perf_output_begin(&handle, event, | |
6152 | lost_samples_event.header.size); | |
6153 | if (ret) | |
6154 | return; | |
6155 | ||
6156 | perf_output_put(&handle, lost_samples_event); | |
6157 | perf_event__output_id_sample(event, &handle, &sample); | |
6158 | perf_output_end(&handle); | |
6159 | } | |
6160 | ||
45ac1403 AH |
6161 | /* |
6162 | * context_switch tracking | |
6163 | */ | |
6164 | ||
6165 | struct perf_switch_event { | |
6166 | struct task_struct *task; | |
6167 | struct task_struct *next_prev; | |
6168 | ||
6169 | struct { | |
6170 | struct perf_event_header header; | |
6171 | u32 next_prev_pid; | |
6172 | u32 next_prev_tid; | |
6173 | } event_id; | |
6174 | }; | |
6175 | ||
6176 | static int perf_event_switch_match(struct perf_event *event) | |
6177 | { | |
6178 | return event->attr.context_switch; | |
6179 | } | |
6180 | ||
6181 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6182 | { | |
6183 | struct perf_switch_event *se = data; | |
6184 | struct perf_output_handle handle; | |
6185 | struct perf_sample_data sample; | |
6186 | int ret; | |
6187 | ||
6188 | if (!perf_event_switch_match(event)) | |
6189 | return; | |
6190 | ||
6191 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6192 | if (event->ctx->task) { | |
6193 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6194 | se->event_id.header.size = sizeof(se->event_id.header); | |
6195 | } else { | |
6196 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6197 | se->event_id.header.size = sizeof(se->event_id); | |
6198 | se->event_id.next_prev_pid = | |
6199 | perf_event_pid(event, se->next_prev); | |
6200 | se->event_id.next_prev_tid = | |
6201 | perf_event_tid(event, se->next_prev); | |
6202 | } | |
6203 | ||
6204 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6205 | ||
6206 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6207 | if (ret) | |
6208 | return; | |
6209 | ||
6210 | if (event->ctx->task) | |
6211 | perf_output_put(&handle, se->event_id.header); | |
6212 | else | |
6213 | perf_output_put(&handle, se->event_id); | |
6214 | ||
6215 | perf_event__output_id_sample(event, &handle, &sample); | |
6216 | ||
6217 | perf_output_end(&handle); | |
6218 | } | |
6219 | ||
6220 | static void perf_event_switch(struct task_struct *task, | |
6221 | struct task_struct *next_prev, bool sched_in) | |
6222 | { | |
6223 | struct perf_switch_event switch_event; | |
6224 | ||
6225 | /* N.B. caller checks nr_switch_events != 0 */ | |
6226 | ||
6227 | switch_event = (struct perf_switch_event){ | |
6228 | .task = task, | |
6229 | .next_prev = next_prev, | |
6230 | .event_id = { | |
6231 | .header = { | |
6232 | /* .type */ | |
6233 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6234 | /* .size */ | |
6235 | }, | |
6236 | /* .next_prev_pid */ | |
6237 | /* .next_prev_tid */ | |
6238 | }, | |
6239 | }; | |
6240 | ||
6241 | perf_event_aux(perf_event_switch_output, | |
6242 | &switch_event, | |
6243 | NULL); | |
6244 | } | |
6245 | ||
a78ac325 PZ |
6246 | /* |
6247 | * IRQ throttle logging | |
6248 | */ | |
6249 | ||
cdd6c482 | 6250 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6251 | { |
6252 | struct perf_output_handle handle; | |
c980d109 | 6253 | struct perf_sample_data sample; |
a78ac325 PZ |
6254 | int ret; |
6255 | ||
6256 | struct { | |
6257 | struct perf_event_header header; | |
6258 | u64 time; | |
cca3f454 | 6259 | u64 id; |
7f453c24 | 6260 | u64 stream_id; |
a78ac325 PZ |
6261 | } throttle_event = { |
6262 | .header = { | |
cdd6c482 | 6263 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6264 | .misc = 0, |
6265 | .size = sizeof(throttle_event), | |
6266 | }, | |
34f43927 | 6267 | .time = perf_event_clock(event), |
cdd6c482 IM |
6268 | .id = primary_event_id(event), |
6269 | .stream_id = event->id, | |
a78ac325 PZ |
6270 | }; |
6271 | ||
966ee4d6 | 6272 | if (enable) |
cdd6c482 | 6273 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6274 | |
c980d109 ACM |
6275 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6276 | ||
6277 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6278 | throttle_event.header.size); |
a78ac325 PZ |
6279 | if (ret) |
6280 | return; | |
6281 | ||
6282 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6283 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6284 | perf_output_end(&handle); |
6285 | } | |
6286 | ||
ec0d7729 AS |
6287 | static void perf_log_itrace_start(struct perf_event *event) |
6288 | { | |
6289 | struct perf_output_handle handle; | |
6290 | struct perf_sample_data sample; | |
6291 | struct perf_aux_event { | |
6292 | struct perf_event_header header; | |
6293 | u32 pid; | |
6294 | u32 tid; | |
6295 | } rec; | |
6296 | int ret; | |
6297 | ||
6298 | if (event->parent) | |
6299 | event = event->parent; | |
6300 | ||
6301 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6302 | event->hw.itrace_started) | |
6303 | return; | |
6304 | ||
ec0d7729 AS |
6305 | rec.header.type = PERF_RECORD_ITRACE_START; |
6306 | rec.header.misc = 0; | |
6307 | rec.header.size = sizeof(rec); | |
6308 | rec.pid = perf_event_pid(event, current); | |
6309 | rec.tid = perf_event_tid(event, current); | |
6310 | ||
6311 | perf_event_header__init_id(&rec.header, &sample, event); | |
6312 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6313 | ||
6314 | if (ret) | |
6315 | return; | |
6316 | ||
6317 | perf_output_put(&handle, rec); | |
6318 | perf_event__output_id_sample(event, &handle, &sample); | |
6319 | ||
6320 | perf_output_end(&handle); | |
6321 | } | |
6322 | ||
f6c7d5fe | 6323 | /* |
cdd6c482 | 6324 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6325 | */ |
6326 | ||
a8b0ca17 | 6327 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6328 | int throttle, struct perf_sample_data *data, |
6329 | struct pt_regs *regs) | |
f6c7d5fe | 6330 | { |
cdd6c482 IM |
6331 | int events = atomic_read(&event->event_limit); |
6332 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6333 | u64 seq; |
79f14641 PZ |
6334 | int ret = 0; |
6335 | ||
96398826 PZ |
6336 | /* |
6337 | * Non-sampling counters might still use the PMI to fold short | |
6338 | * hardware counters, ignore those. | |
6339 | */ | |
6340 | if (unlikely(!is_sampling_event(event))) | |
6341 | return 0; | |
6342 | ||
e050e3f0 SE |
6343 | seq = __this_cpu_read(perf_throttled_seq); |
6344 | if (seq != hwc->interrupts_seq) { | |
6345 | hwc->interrupts_seq = seq; | |
6346 | hwc->interrupts = 1; | |
6347 | } else { | |
6348 | hwc->interrupts++; | |
6349 | if (unlikely(throttle | |
6350 | && hwc->interrupts >= max_samples_per_tick)) { | |
6351 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6352 | hwc->interrupts = MAX_INTERRUPTS; |
6353 | perf_log_throttle(event, 0); | |
d84153d6 | 6354 | tick_nohz_full_kick(); |
a78ac325 PZ |
6355 | ret = 1; |
6356 | } | |
e050e3f0 | 6357 | } |
60db5e09 | 6358 | |
cdd6c482 | 6359 | if (event->attr.freq) { |
def0a9b2 | 6360 | u64 now = perf_clock(); |
abd50713 | 6361 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6362 | |
abd50713 | 6363 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6364 | |
abd50713 | 6365 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6366 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6367 | } |
6368 | ||
2023b359 PZ |
6369 | /* |
6370 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6371 | * events |
2023b359 PZ |
6372 | */ |
6373 | ||
cdd6c482 IM |
6374 | event->pending_kill = POLL_IN; |
6375 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6376 | ret = 1; |
cdd6c482 | 6377 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6378 | event->pending_disable = 1; |
6379 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6380 | } |
6381 | ||
453f19ee | 6382 | if (event->overflow_handler) |
a8b0ca17 | 6383 | event->overflow_handler(event, data, regs); |
453f19ee | 6384 | else |
a8b0ca17 | 6385 | perf_event_output(event, data, regs); |
453f19ee | 6386 | |
fed66e2c | 6387 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6388 | event->pending_wakeup = 1; |
6389 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6390 | } |
6391 | ||
79f14641 | 6392 | return ret; |
f6c7d5fe PZ |
6393 | } |
6394 | ||
a8b0ca17 | 6395 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6396 | struct perf_sample_data *data, |
6397 | struct pt_regs *regs) | |
850bc73f | 6398 | { |
a8b0ca17 | 6399 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6400 | } |
6401 | ||
15dbf27c | 6402 | /* |
cdd6c482 | 6403 | * Generic software event infrastructure |
15dbf27c PZ |
6404 | */ |
6405 | ||
b28ab83c PZ |
6406 | struct swevent_htable { |
6407 | struct swevent_hlist *swevent_hlist; | |
6408 | struct mutex hlist_mutex; | |
6409 | int hlist_refcount; | |
6410 | ||
6411 | /* Recursion avoidance in each contexts */ | |
6412 | int recursion[PERF_NR_CONTEXTS]; | |
6413 | }; | |
6414 | ||
6415 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6416 | ||
7b4b6658 | 6417 | /* |
cdd6c482 IM |
6418 | * We directly increment event->count and keep a second value in |
6419 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6420 | * is kept in the range [-sample_period, 0] so that we can use the |
6421 | * sign as trigger. | |
6422 | */ | |
6423 | ||
ab573844 | 6424 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6425 | { |
cdd6c482 | 6426 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6427 | u64 period = hwc->last_period; |
6428 | u64 nr, offset; | |
6429 | s64 old, val; | |
6430 | ||
6431 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6432 | |
6433 | again: | |
e7850595 | 6434 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6435 | if (val < 0) |
6436 | return 0; | |
15dbf27c | 6437 | |
7b4b6658 PZ |
6438 | nr = div64_u64(period + val, period); |
6439 | offset = nr * period; | |
6440 | val -= offset; | |
e7850595 | 6441 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6442 | goto again; |
15dbf27c | 6443 | |
7b4b6658 | 6444 | return nr; |
15dbf27c PZ |
6445 | } |
6446 | ||
0cff784a | 6447 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6448 | struct perf_sample_data *data, |
5622f295 | 6449 | struct pt_regs *regs) |
15dbf27c | 6450 | { |
cdd6c482 | 6451 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6452 | int throttle = 0; |
15dbf27c | 6453 | |
0cff784a PZ |
6454 | if (!overflow) |
6455 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6456 | |
7b4b6658 PZ |
6457 | if (hwc->interrupts == MAX_INTERRUPTS) |
6458 | return; | |
15dbf27c | 6459 | |
7b4b6658 | 6460 | for (; overflow; overflow--) { |
a8b0ca17 | 6461 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6462 | data, regs)) { |
7b4b6658 PZ |
6463 | /* |
6464 | * We inhibit the overflow from happening when | |
6465 | * hwc->interrupts == MAX_INTERRUPTS. | |
6466 | */ | |
6467 | break; | |
6468 | } | |
cf450a73 | 6469 | throttle = 1; |
7b4b6658 | 6470 | } |
15dbf27c PZ |
6471 | } |
6472 | ||
a4eaf7f1 | 6473 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6474 | struct perf_sample_data *data, |
5622f295 | 6475 | struct pt_regs *regs) |
7b4b6658 | 6476 | { |
cdd6c482 | 6477 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6478 | |
e7850595 | 6479 | local64_add(nr, &event->count); |
d6d020e9 | 6480 | |
0cff784a PZ |
6481 | if (!regs) |
6482 | return; | |
6483 | ||
6c7e550f | 6484 | if (!is_sampling_event(event)) |
7b4b6658 | 6485 | return; |
d6d020e9 | 6486 | |
5d81e5cf AV |
6487 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6488 | data->period = nr; | |
6489 | return perf_swevent_overflow(event, 1, data, regs); | |
6490 | } else | |
6491 | data->period = event->hw.last_period; | |
6492 | ||
0cff784a | 6493 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6494 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6495 | |
e7850595 | 6496 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6497 | return; |
df1a132b | 6498 | |
a8b0ca17 | 6499 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6500 | } |
6501 | ||
f5ffe02e FW |
6502 | static int perf_exclude_event(struct perf_event *event, |
6503 | struct pt_regs *regs) | |
6504 | { | |
a4eaf7f1 | 6505 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6506 | return 1; |
a4eaf7f1 | 6507 | |
f5ffe02e FW |
6508 | if (regs) { |
6509 | if (event->attr.exclude_user && user_mode(regs)) | |
6510 | return 1; | |
6511 | ||
6512 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6513 | return 1; | |
6514 | } | |
6515 | ||
6516 | return 0; | |
6517 | } | |
6518 | ||
cdd6c482 | 6519 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6520 | enum perf_type_id type, |
6fb2915d LZ |
6521 | u32 event_id, |
6522 | struct perf_sample_data *data, | |
6523 | struct pt_regs *regs) | |
15dbf27c | 6524 | { |
cdd6c482 | 6525 | if (event->attr.type != type) |
a21ca2ca | 6526 | return 0; |
f5ffe02e | 6527 | |
cdd6c482 | 6528 | if (event->attr.config != event_id) |
15dbf27c PZ |
6529 | return 0; |
6530 | ||
f5ffe02e FW |
6531 | if (perf_exclude_event(event, regs)) |
6532 | return 0; | |
15dbf27c PZ |
6533 | |
6534 | return 1; | |
6535 | } | |
6536 | ||
76e1d904 FW |
6537 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6538 | { | |
6539 | u64 val = event_id | (type << 32); | |
6540 | ||
6541 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6542 | } | |
6543 | ||
49f135ed FW |
6544 | static inline struct hlist_head * |
6545 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6546 | { |
49f135ed FW |
6547 | u64 hash = swevent_hash(type, event_id); |
6548 | ||
6549 | return &hlist->heads[hash]; | |
6550 | } | |
76e1d904 | 6551 | |
49f135ed FW |
6552 | /* For the read side: events when they trigger */ |
6553 | static inline struct hlist_head * | |
b28ab83c | 6554 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6555 | { |
6556 | struct swevent_hlist *hlist; | |
76e1d904 | 6557 | |
b28ab83c | 6558 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6559 | if (!hlist) |
6560 | return NULL; | |
6561 | ||
49f135ed FW |
6562 | return __find_swevent_head(hlist, type, event_id); |
6563 | } | |
6564 | ||
6565 | /* For the event head insertion and removal in the hlist */ | |
6566 | static inline struct hlist_head * | |
b28ab83c | 6567 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6568 | { |
6569 | struct swevent_hlist *hlist; | |
6570 | u32 event_id = event->attr.config; | |
6571 | u64 type = event->attr.type; | |
6572 | ||
6573 | /* | |
6574 | * Event scheduling is always serialized against hlist allocation | |
6575 | * and release. Which makes the protected version suitable here. | |
6576 | * The context lock guarantees that. | |
6577 | */ | |
b28ab83c | 6578 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6579 | lockdep_is_held(&event->ctx->lock)); |
6580 | if (!hlist) | |
6581 | return NULL; | |
6582 | ||
6583 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6584 | } |
6585 | ||
6586 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6587 | u64 nr, |
76e1d904 FW |
6588 | struct perf_sample_data *data, |
6589 | struct pt_regs *regs) | |
15dbf27c | 6590 | { |
4a32fea9 | 6591 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6592 | struct perf_event *event; |
76e1d904 | 6593 | struct hlist_head *head; |
15dbf27c | 6594 | |
76e1d904 | 6595 | rcu_read_lock(); |
b28ab83c | 6596 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6597 | if (!head) |
6598 | goto end; | |
6599 | ||
b67bfe0d | 6600 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6601 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6602 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6603 | } |
76e1d904 FW |
6604 | end: |
6605 | rcu_read_unlock(); | |
15dbf27c PZ |
6606 | } |
6607 | ||
86038c5e PZI |
6608 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6609 | ||
4ed7c92d | 6610 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6611 | { |
4a32fea9 | 6612 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6613 | |
b28ab83c | 6614 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6615 | } |
645e8cc0 | 6616 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6617 | |
fa9f90be | 6618 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6619 | { |
4a32fea9 | 6620 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6621 | |
b28ab83c | 6622 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6623 | } |
15dbf27c | 6624 | |
86038c5e | 6625 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6626 | { |
a4234bfc | 6627 | struct perf_sample_data data; |
4ed7c92d | 6628 | |
86038c5e | 6629 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6630 | return; |
a4234bfc | 6631 | |
fd0d000b | 6632 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6633 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6634 | } |
6635 | ||
6636 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6637 | { | |
6638 | int rctx; | |
6639 | ||
6640 | preempt_disable_notrace(); | |
6641 | rctx = perf_swevent_get_recursion_context(); | |
6642 | if (unlikely(rctx < 0)) | |
6643 | goto fail; | |
6644 | ||
6645 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6646 | |
6647 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6648 | fail: |
1c024eca | 6649 | preempt_enable_notrace(); |
b8e83514 PZ |
6650 | } |
6651 | ||
cdd6c482 | 6652 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6653 | { |
15dbf27c PZ |
6654 | } |
6655 | ||
a4eaf7f1 | 6656 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6657 | { |
4a32fea9 | 6658 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6659 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6660 | struct hlist_head *head; |
6661 | ||
6c7e550f | 6662 | if (is_sampling_event(event)) { |
7b4b6658 | 6663 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6664 | perf_swevent_set_period(event); |
7b4b6658 | 6665 | } |
76e1d904 | 6666 | |
a4eaf7f1 PZ |
6667 | hwc->state = !(flags & PERF_EF_START); |
6668 | ||
b28ab83c | 6669 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6670 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6671 | return -EINVAL; |
6672 | ||
6673 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6674 | perf_event_update_userpage(event); |
76e1d904 | 6675 | |
15dbf27c PZ |
6676 | return 0; |
6677 | } | |
6678 | ||
a4eaf7f1 | 6679 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6680 | { |
76e1d904 | 6681 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6682 | } |
6683 | ||
a4eaf7f1 | 6684 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6685 | { |
a4eaf7f1 | 6686 | event->hw.state = 0; |
d6d020e9 | 6687 | } |
aa9c4c0f | 6688 | |
a4eaf7f1 | 6689 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6690 | { |
a4eaf7f1 | 6691 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6692 | } |
6693 | ||
49f135ed FW |
6694 | /* Deref the hlist from the update side */ |
6695 | static inline struct swevent_hlist * | |
b28ab83c | 6696 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6697 | { |
b28ab83c PZ |
6698 | return rcu_dereference_protected(swhash->swevent_hlist, |
6699 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6700 | } |
6701 | ||
b28ab83c | 6702 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6703 | { |
b28ab83c | 6704 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6705 | |
49f135ed | 6706 | if (!hlist) |
76e1d904 FW |
6707 | return; |
6708 | ||
70691d4a | 6709 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6710 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6711 | } |
6712 | ||
6713 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6714 | { | |
b28ab83c | 6715 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6716 | |
b28ab83c | 6717 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6718 | |
b28ab83c PZ |
6719 | if (!--swhash->hlist_refcount) |
6720 | swevent_hlist_release(swhash); | |
76e1d904 | 6721 | |
b28ab83c | 6722 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6723 | } |
6724 | ||
6725 | static void swevent_hlist_put(struct perf_event *event) | |
6726 | { | |
6727 | int cpu; | |
6728 | ||
76e1d904 FW |
6729 | for_each_possible_cpu(cpu) |
6730 | swevent_hlist_put_cpu(event, cpu); | |
6731 | } | |
6732 | ||
6733 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6734 | { | |
b28ab83c | 6735 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6736 | int err = 0; |
6737 | ||
b28ab83c | 6738 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6739 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6740 | struct swevent_hlist *hlist; |
6741 | ||
6742 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6743 | if (!hlist) { | |
6744 | err = -ENOMEM; | |
6745 | goto exit; | |
6746 | } | |
b28ab83c | 6747 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6748 | } |
b28ab83c | 6749 | swhash->hlist_refcount++; |
9ed6060d | 6750 | exit: |
b28ab83c | 6751 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6752 | |
6753 | return err; | |
6754 | } | |
6755 | ||
6756 | static int swevent_hlist_get(struct perf_event *event) | |
6757 | { | |
6758 | int err; | |
6759 | int cpu, failed_cpu; | |
6760 | ||
76e1d904 FW |
6761 | get_online_cpus(); |
6762 | for_each_possible_cpu(cpu) { | |
6763 | err = swevent_hlist_get_cpu(event, cpu); | |
6764 | if (err) { | |
6765 | failed_cpu = cpu; | |
6766 | goto fail; | |
6767 | } | |
6768 | } | |
6769 | put_online_cpus(); | |
6770 | ||
6771 | return 0; | |
9ed6060d | 6772 | fail: |
76e1d904 FW |
6773 | for_each_possible_cpu(cpu) { |
6774 | if (cpu == failed_cpu) | |
6775 | break; | |
6776 | swevent_hlist_put_cpu(event, cpu); | |
6777 | } | |
6778 | ||
6779 | put_online_cpus(); | |
6780 | return err; | |
6781 | } | |
6782 | ||
c5905afb | 6783 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6784 | |
b0a873eb PZ |
6785 | static void sw_perf_event_destroy(struct perf_event *event) |
6786 | { | |
6787 | u64 event_id = event->attr.config; | |
95476b64 | 6788 | |
b0a873eb PZ |
6789 | WARN_ON(event->parent); |
6790 | ||
c5905afb | 6791 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6792 | swevent_hlist_put(event); |
6793 | } | |
6794 | ||
6795 | static int perf_swevent_init(struct perf_event *event) | |
6796 | { | |
8176cced | 6797 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6798 | |
6799 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6800 | return -ENOENT; | |
6801 | ||
2481c5fa SE |
6802 | /* |
6803 | * no branch sampling for software events | |
6804 | */ | |
6805 | if (has_branch_stack(event)) | |
6806 | return -EOPNOTSUPP; | |
6807 | ||
b0a873eb PZ |
6808 | switch (event_id) { |
6809 | case PERF_COUNT_SW_CPU_CLOCK: | |
6810 | case PERF_COUNT_SW_TASK_CLOCK: | |
6811 | return -ENOENT; | |
6812 | ||
6813 | default: | |
6814 | break; | |
6815 | } | |
6816 | ||
ce677831 | 6817 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6818 | return -ENOENT; |
6819 | ||
6820 | if (!event->parent) { | |
6821 | int err; | |
6822 | ||
6823 | err = swevent_hlist_get(event); | |
6824 | if (err) | |
6825 | return err; | |
6826 | ||
c5905afb | 6827 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6828 | event->destroy = sw_perf_event_destroy; |
6829 | } | |
6830 | ||
6831 | return 0; | |
6832 | } | |
6833 | ||
6834 | static struct pmu perf_swevent = { | |
89a1e187 | 6835 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6836 | |
34f43927 PZ |
6837 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6838 | ||
b0a873eb | 6839 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6840 | .add = perf_swevent_add, |
6841 | .del = perf_swevent_del, | |
6842 | .start = perf_swevent_start, | |
6843 | .stop = perf_swevent_stop, | |
1c024eca | 6844 | .read = perf_swevent_read, |
1c024eca PZ |
6845 | }; |
6846 | ||
b0a873eb PZ |
6847 | #ifdef CONFIG_EVENT_TRACING |
6848 | ||
1c024eca PZ |
6849 | static int perf_tp_filter_match(struct perf_event *event, |
6850 | struct perf_sample_data *data) | |
6851 | { | |
6852 | void *record = data->raw->data; | |
6853 | ||
b71b437e PZ |
6854 | /* only top level events have filters set */ |
6855 | if (event->parent) | |
6856 | event = event->parent; | |
6857 | ||
1c024eca PZ |
6858 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6859 | return 1; | |
6860 | return 0; | |
6861 | } | |
6862 | ||
6863 | static int perf_tp_event_match(struct perf_event *event, | |
6864 | struct perf_sample_data *data, | |
6865 | struct pt_regs *regs) | |
6866 | { | |
a0f7d0f7 FW |
6867 | if (event->hw.state & PERF_HES_STOPPED) |
6868 | return 0; | |
580d607c PZ |
6869 | /* |
6870 | * All tracepoints are from kernel-space. | |
6871 | */ | |
6872 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6873 | return 0; |
6874 | ||
6875 | if (!perf_tp_filter_match(event, data)) | |
6876 | return 0; | |
6877 | ||
6878 | return 1; | |
6879 | } | |
6880 | ||
6881 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6882 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6883 | struct task_struct *task) | |
95476b64 FW |
6884 | { |
6885 | struct perf_sample_data data; | |
1c024eca | 6886 | struct perf_event *event; |
1c024eca | 6887 | |
95476b64 FW |
6888 | struct perf_raw_record raw = { |
6889 | .size = entry_size, | |
6890 | .data = record, | |
6891 | }; | |
6892 | ||
fd0d000b | 6893 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6894 | data.raw = &raw; |
6895 | ||
b67bfe0d | 6896 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6897 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6898 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6899 | } |
ecc55f84 | 6900 | |
e6dab5ff AV |
6901 | /* |
6902 | * If we got specified a target task, also iterate its context and | |
6903 | * deliver this event there too. | |
6904 | */ | |
6905 | if (task && task != current) { | |
6906 | struct perf_event_context *ctx; | |
6907 | struct trace_entry *entry = record; | |
6908 | ||
6909 | rcu_read_lock(); | |
6910 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6911 | if (!ctx) | |
6912 | goto unlock; | |
6913 | ||
6914 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6915 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6916 | continue; | |
6917 | if (event->attr.config != entry->type) | |
6918 | continue; | |
6919 | if (perf_tp_event_match(event, &data, regs)) | |
6920 | perf_swevent_event(event, count, &data, regs); | |
6921 | } | |
6922 | unlock: | |
6923 | rcu_read_unlock(); | |
6924 | } | |
6925 | ||
ecc55f84 | 6926 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6927 | } |
6928 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6929 | ||
cdd6c482 | 6930 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6931 | { |
1c024eca | 6932 | perf_trace_destroy(event); |
e077df4f PZ |
6933 | } |
6934 | ||
b0a873eb | 6935 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6936 | { |
76e1d904 FW |
6937 | int err; |
6938 | ||
b0a873eb PZ |
6939 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6940 | return -ENOENT; | |
6941 | ||
2481c5fa SE |
6942 | /* |
6943 | * no branch sampling for tracepoint events | |
6944 | */ | |
6945 | if (has_branch_stack(event)) | |
6946 | return -EOPNOTSUPP; | |
6947 | ||
1c024eca PZ |
6948 | err = perf_trace_init(event); |
6949 | if (err) | |
b0a873eb | 6950 | return err; |
e077df4f | 6951 | |
cdd6c482 | 6952 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6953 | |
b0a873eb PZ |
6954 | return 0; |
6955 | } | |
6956 | ||
6957 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6958 | .task_ctx_nr = perf_sw_context, |
6959 | ||
b0a873eb | 6960 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6961 | .add = perf_trace_add, |
6962 | .del = perf_trace_del, | |
6963 | .start = perf_swevent_start, | |
6964 | .stop = perf_swevent_stop, | |
b0a873eb | 6965 | .read = perf_swevent_read, |
b0a873eb PZ |
6966 | }; |
6967 | ||
6968 | static inline void perf_tp_register(void) | |
6969 | { | |
2e80a82a | 6970 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6971 | } |
6fb2915d LZ |
6972 | |
6973 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6974 | { | |
6975 | char *filter_str; | |
6976 | int ret; | |
6977 | ||
6978 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6979 | return -EINVAL; | |
6980 | ||
6981 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6982 | if (IS_ERR(filter_str)) | |
6983 | return PTR_ERR(filter_str); | |
6984 | ||
6985 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6986 | ||
6987 | kfree(filter_str); | |
6988 | return ret; | |
6989 | } | |
6990 | ||
6991 | static void perf_event_free_filter(struct perf_event *event) | |
6992 | { | |
6993 | ftrace_profile_free_filter(event); | |
6994 | } | |
6995 | ||
2541517c AS |
6996 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
6997 | { | |
6998 | struct bpf_prog *prog; | |
6999 | ||
7000 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7001 | return -EINVAL; | |
7002 | ||
7003 | if (event->tp_event->prog) | |
7004 | return -EEXIST; | |
7005 | ||
04a22fae WN |
7006 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7007 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7008 | return -EINVAL; |
7009 | ||
7010 | prog = bpf_prog_get(prog_fd); | |
7011 | if (IS_ERR(prog)) | |
7012 | return PTR_ERR(prog); | |
7013 | ||
6c373ca8 | 7014 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7015 | /* valid fd, but invalid bpf program type */ |
7016 | bpf_prog_put(prog); | |
7017 | return -EINVAL; | |
7018 | } | |
7019 | ||
7020 | event->tp_event->prog = prog; | |
7021 | ||
7022 | return 0; | |
7023 | } | |
7024 | ||
7025 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7026 | { | |
7027 | struct bpf_prog *prog; | |
7028 | ||
7029 | if (!event->tp_event) | |
7030 | return; | |
7031 | ||
7032 | prog = event->tp_event->prog; | |
7033 | if (prog) { | |
7034 | event->tp_event->prog = NULL; | |
7035 | bpf_prog_put(prog); | |
7036 | } | |
7037 | } | |
7038 | ||
e077df4f | 7039 | #else |
6fb2915d | 7040 | |
b0a873eb | 7041 | static inline void perf_tp_register(void) |
e077df4f | 7042 | { |
e077df4f | 7043 | } |
6fb2915d LZ |
7044 | |
7045 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7046 | { | |
7047 | return -ENOENT; | |
7048 | } | |
7049 | ||
7050 | static void perf_event_free_filter(struct perf_event *event) | |
7051 | { | |
7052 | } | |
7053 | ||
2541517c AS |
7054 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7055 | { | |
7056 | return -ENOENT; | |
7057 | } | |
7058 | ||
7059 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7060 | { | |
7061 | } | |
07b139c8 | 7062 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7063 | |
24f1e32c | 7064 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7065 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7066 | { |
f5ffe02e FW |
7067 | struct perf_sample_data sample; |
7068 | struct pt_regs *regs = data; | |
7069 | ||
fd0d000b | 7070 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7071 | |
a4eaf7f1 | 7072 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7073 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7074 | } |
7075 | #endif | |
7076 | ||
b0a873eb PZ |
7077 | /* |
7078 | * hrtimer based swevent callback | |
7079 | */ | |
f29ac756 | 7080 | |
b0a873eb | 7081 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7082 | { |
b0a873eb PZ |
7083 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7084 | struct perf_sample_data data; | |
7085 | struct pt_regs *regs; | |
7086 | struct perf_event *event; | |
7087 | u64 period; | |
f29ac756 | 7088 | |
b0a873eb | 7089 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7090 | |
7091 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7092 | return HRTIMER_NORESTART; | |
7093 | ||
b0a873eb | 7094 | event->pmu->read(event); |
f344011c | 7095 | |
fd0d000b | 7096 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7097 | regs = get_irq_regs(); |
7098 | ||
7099 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7100 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7101 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7102 | ret = HRTIMER_NORESTART; |
7103 | } | |
24f1e32c | 7104 | |
b0a873eb PZ |
7105 | period = max_t(u64, 10000, event->hw.sample_period); |
7106 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7107 | |
b0a873eb | 7108 | return ret; |
f29ac756 PZ |
7109 | } |
7110 | ||
b0a873eb | 7111 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7112 | { |
b0a873eb | 7113 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7114 | s64 period; |
7115 | ||
7116 | if (!is_sampling_event(event)) | |
7117 | return; | |
f5ffe02e | 7118 | |
5d508e82 FBH |
7119 | period = local64_read(&hwc->period_left); |
7120 | if (period) { | |
7121 | if (period < 0) | |
7122 | period = 10000; | |
fa407f35 | 7123 | |
5d508e82 FBH |
7124 | local64_set(&hwc->period_left, 0); |
7125 | } else { | |
7126 | period = max_t(u64, 10000, hwc->sample_period); | |
7127 | } | |
3497d206 TG |
7128 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7129 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7130 | } |
b0a873eb PZ |
7131 | |
7132 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7133 | { |
b0a873eb PZ |
7134 | struct hw_perf_event *hwc = &event->hw; |
7135 | ||
6c7e550f | 7136 | if (is_sampling_event(event)) { |
b0a873eb | 7137 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7138 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7139 | |
7140 | hrtimer_cancel(&hwc->hrtimer); | |
7141 | } | |
24f1e32c FW |
7142 | } |
7143 | ||
ba3dd36c PZ |
7144 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7145 | { | |
7146 | struct hw_perf_event *hwc = &event->hw; | |
7147 | ||
7148 | if (!is_sampling_event(event)) | |
7149 | return; | |
7150 | ||
7151 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7152 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7153 | ||
7154 | /* | |
7155 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7156 | * mapping and avoid the whole period adjust feedback stuff. | |
7157 | */ | |
7158 | if (event->attr.freq) { | |
7159 | long freq = event->attr.sample_freq; | |
7160 | ||
7161 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7162 | hwc->sample_period = event->attr.sample_period; | |
7163 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7164 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7165 | event->attr.freq = 0; |
7166 | } | |
7167 | } | |
7168 | ||
b0a873eb PZ |
7169 | /* |
7170 | * Software event: cpu wall time clock | |
7171 | */ | |
7172 | ||
7173 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7174 | { |
b0a873eb PZ |
7175 | s64 prev; |
7176 | u64 now; | |
7177 | ||
a4eaf7f1 | 7178 | now = local_clock(); |
b0a873eb PZ |
7179 | prev = local64_xchg(&event->hw.prev_count, now); |
7180 | local64_add(now - prev, &event->count); | |
24f1e32c | 7181 | } |
24f1e32c | 7182 | |
a4eaf7f1 | 7183 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7184 | { |
a4eaf7f1 | 7185 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7186 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7187 | } |
7188 | ||
a4eaf7f1 | 7189 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7190 | { |
b0a873eb PZ |
7191 | perf_swevent_cancel_hrtimer(event); |
7192 | cpu_clock_event_update(event); | |
7193 | } | |
f29ac756 | 7194 | |
a4eaf7f1 PZ |
7195 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7196 | { | |
7197 | if (flags & PERF_EF_START) | |
7198 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7199 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7200 | |
7201 | return 0; | |
7202 | } | |
7203 | ||
7204 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7205 | { | |
7206 | cpu_clock_event_stop(event, flags); | |
7207 | } | |
7208 | ||
b0a873eb PZ |
7209 | static void cpu_clock_event_read(struct perf_event *event) |
7210 | { | |
7211 | cpu_clock_event_update(event); | |
7212 | } | |
f344011c | 7213 | |
b0a873eb PZ |
7214 | static int cpu_clock_event_init(struct perf_event *event) |
7215 | { | |
7216 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7217 | return -ENOENT; | |
7218 | ||
7219 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7220 | return -ENOENT; | |
7221 | ||
2481c5fa SE |
7222 | /* |
7223 | * no branch sampling for software events | |
7224 | */ | |
7225 | if (has_branch_stack(event)) | |
7226 | return -EOPNOTSUPP; | |
7227 | ||
ba3dd36c PZ |
7228 | perf_swevent_init_hrtimer(event); |
7229 | ||
b0a873eb | 7230 | return 0; |
f29ac756 PZ |
7231 | } |
7232 | ||
b0a873eb | 7233 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7234 | .task_ctx_nr = perf_sw_context, |
7235 | ||
34f43927 PZ |
7236 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7237 | ||
b0a873eb | 7238 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7239 | .add = cpu_clock_event_add, |
7240 | .del = cpu_clock_event_del, | |
7241 | .start = cpu_clock_event_start, | |
7242 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7243 | .read = cpu_clock_event_read, |
7244 | }; | |
7245 | ||
7246 | /* | |
7247 | * Software event: task time clock | |
7248 | */ | |
7249 | ||
7250 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7251 | { |
b0a873eb PZ |
7252 | u64 prev; |
7253 | s64 delta; | |
5c92d124 | 7254 | |
b0a873eb PZ |
7255 | prev = local64_xchg(&event->hw.prev_count, now); |
7256 | delta = now - prev; | |
7257 | local64_add(delta, &event->count); | |
7258 | } | |
5c92d124 | 7259 | |
a4eaf7f1 | 7260 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7261 | { |
a4eaf7f1 | 7262 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7263 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7264 | } |
7265 | ||
a4eaf7f1 | 7266 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7267 | { |
7268 | perf_swevent_cancel_hrtimer(event); | |
7269 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7270 | } |
7271 | ||
7272 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7273 | { | |
7274 | if (flags & PERF_EF_START) | |
7275 | task_clock_event_start(event, flags); | |
6a694a60 | 7276 | perf_event_update_userpage(event); |
b0a873eb | 7277 | |
a4eaf7f1 PZ |
7278 | return 0; |
7279 | } | |
7280 | ||
7281 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7282 | { | |
7283 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7284 | } |
7285 | ||
7286 | static void task_clock_event_read(struct perf_event *event) | |
7287 | { | |
768a06e2 PZ |
7288 | u64 now = perf_clock(); |
7289 | u64 delta = now - event->ctx->timestamp; | |
7290 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7291 | |
7292 | task_clock_event_update(event, time); | |
7293 | } | |
7294 | ||
7295 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7296 | { |
b0a873eb PZ |
7297 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7298 | return -ENOENT; | |
7299 | ||
7300 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7301 | return -ENOENT; | |
7302 | ||
2481c5fa SE |
7303 | /* |
7304 | * no branch sampling for software events | |
7305 | */ | |
7306 | if (has_branch_stack(event)) | |
7307 | return -EOPNOTSUPP; | |
7308 | ||
ba3dd36c PZ |
7309 | perf_swevent_init_hrtimer(event); |
7310 | ||
b0a873eb | 7311 | return 0; |
6fb2915d LZ |
7312 | } |
7313 | ||
b0a873eb | 7314 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7315 | .task_ctx_nr = perf_sw_context, |
7316 | ||
34f43927 PZ |
7317 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7318 | ||
b0a873eb | 7319 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7320 | .add = task_clock_event_add, |
7321 | .del = task_clock_event_del, | |
7322 | .start = task_clock_event_start, | |
7323 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7324 | .read = task_clock_event_read, |
7325 | }; | |
6fb2915d | 7326 | |
ad5133b7 | 7327 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7328 | { |
e077df4f | 7329 | } |
6fb2915d | 7330 | |
fbbe0701 SB |
7331 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7332 | { | |
7333 | } | |
7334 | ||
ad5133b7 | 7335 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7336 | { |
ad5133b7 | 7337 | return 0; |
6fb2915d LZ |
7338 | } |
7339 | ||
18ab2cd3 | 7340 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7341 | |
7342 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7343 | { |
fbbe0701 SB |
7344 | __this_cpu_write(nop_txn_flags, flags); |
7345 | ||
7346 | if (flags & ~PERF_PMU_TXN_ADD) | |
7347 | return; | |
7348 | ||
ad5133b7 | 7349 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7350 | } |
7351 | ||
ad5133b7 PZ |
7352 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7353 | { | |
fbbe0701 SB |
7354 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7355 | ||
7356 | __this_cpu_write(nop_txn_flags, 0); | |
7357 | ||
7358 | if (flags & ~PERF_PMU_TXN_ADD) | |
7359 | return 0; | |
7360 | ||
ad5133b7 PZ |
7361 | perf_pmu_enable(pmu); |
7362 | return 0; | |
7363 | } | |
e077df4f | 7364 | |
ad5133b7 | 7365 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7366 | { |
fbbe0701 SB |
7367 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7368 | ||
7369 | __this_cpu_write(nop_txn_flags, 0); | |
7370 | ||
7371 | if (flags & ~PERF_PMU_TXN_ADD) | |
7372 | return; | |
7373 | ||
ad5133b7 | 7374 | perf_pmu_enable(pmu); |
24f1e32c FW |
7375 | } |
7376 | ||
35edc2a5 PZ |
7377 | static int perf_event_idx_default(struct perf_event *event) |
7378 | { | |
c719f560 | 7379 | return 0; |
35edc2a5 PZ |
7380 | } |
7381 | ||
8dc85d54 PZ |
7382 | /* |
7383 | * Ensures all contexts with the same task_ctx_nr have the same | |
7384 | * pmu_cpu_context too. | |
7385 | */ | |
9e317041 | 7386 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7387 | { |
8dc85d54 | 7388 | struct pmu *pmu; |
b326e956 | 7389 | |
8dc85d54 PZ |
7390 | if (ctxn < 0) |
7391 | return NULL; | |
24f1e32c | 7392 | |
8dc85d54 PZ |
7393 | list_for_each_entry(pmu, &pmus, entry) { |
7394 | if (pmu->task_ctx_nr == ctxn) | |
7395 | return pmu->pmu_cpu_context; | |
7396 | } | |
24f1e32c | 7397 | |
8dc85d54 | 7398 | return NULL; |
24f1e32c FW |
7399 | } |
7400 | ||
51676957 | 7401 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7402 | { |
51676957 PZ |
7403 | int cpu; |
7404 | ||
7405 | for_each_possible_cpu(cpu) { | |
7406 | struct perf_cpu_context *cpuctx; | |
7407 | ||
7408 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7409 | ||
3f1f3320 PZ |
7410 | if (cpuctx->unique_pmu == old_pmu) |
7411 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7412 | } |
7413 | } | |
7414 | ||
7415 | static void free_pmu_context(struct pmu *pmu) | |
7416 | { | |
7417 | struct pmu *i; | |
f5ffe02e | 7418 | |
8dc85d54 | 7419 | mutex_lock(&pmus_lock); |
0475f9ea | 7420 | /* |
8dc85d54 | 7421 | * Like a real lame refcount. |
0475f9ea | 7422 | */ |
51676957 PZ |
7423 | list_for_each_entry(i, &pmus, entry) { |
7424 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7425 | update_pmu_context(i, pmu); | |
8dc85d54 | 7426 | goto out; |
51676957 | 7427 | } |
8dc85d54 | 7428 | } |
d6d020e9 | 7429 | |
51676957 | 7430 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7431 | out: |
7432 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7433 | } |
2e80a82a | 7434 | static struct idr pmu_idr; |
d6d020e9 | 7435 | |
abe43400 PZ |
7436 | static ssize_t |
7437 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7438 | { | |
7439 | struct pmu *pmu = dev_get_drvdata(dev); | |
7440 | ||
7441 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7442 | } | |
90826ca7 | 7443 | static DEVICE_ATTR_RO(type); |
abe43400 | 7444 | |
62b85639 SE |
7445 | static ssize_t |
7446 | perf_event_mux_interval_ms_show(struct device *dev, | |
7447 | struct device_attribute *attr, | |
7448 | char *page) | |
7449 | { | |
7450 | struct pmu *pmu = dev_get_drvdata(dev); | |
7451 | ||
7452 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7453 | } | |
7454 | ||
272325c4 PZ |
7455 | static DEFINE_MUTEX(mux_interval_mutex); |
7456 | ||
62b85639 SE |
7457 | static ssize_t |
7458 | perf_event_mux_interval_ms_store(struct device *dev, | |
7459 | struct device_attribute *attr, | |
7460 | const char *buf, size_t count) | |
7461 | { | |
7462 | struct pmu *pmu = dev_get_drvdata(dev); | |
7463 | int timer, cpu, ret; | |
7464 | ||
7465 | ret = kstrtoint(buf, 0, &timer); | |
7466 | if (ret) | |
7467 | return ret; | |
7468 | ||
7469 | if (timer < 1) | |
7470 | return -EINVAL; | |
7471 | ||
7472 | /* same value, noting to do */ | |
7473 | if (timer == pmu->hrtimer_interval_ms) | |
7474 | return count; | |
7475 | ||
272325c4 | 7476 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7477 | pmu->hrtimer_interval_ms = timer; |
7478 | ||
7479 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7480 | get_online_cpus(); |
7481 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7482 | struct perf_cpu_context *cpuctx; |
7483 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7484 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7485 | ||
272325c4 PZ |
7486 | cpu_function_call(cpu, |
7487 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7488 | } |
272325c4 PZ |
7489 | put_online_cpus(); |
7490 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7491 | |
7492 | return count; | |
7493 | } | |
90826ca7 | 7494 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7495 | |
90826ca7 GKH |
7496 | static struct attribute *pmu_dev_attrs[] = { |
7497 | &dev_attr_type.attr, | |
7498 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7499 | NULL, | |
abe43400 | 7500 | }; |
90826ca7 | 7501 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7502 | |
7503 | static int pmu_bus_running; | |
7504 | static struct bus_type pmu_bus = { | |
7505 | .name = "event_source", | |
90826ca7 | 7506 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7507 | }; |
7508 | ||
7509 | static void pmu_dev_release(struct device *dev) | |
7510 | { | |
7511 | kfree(dev); | |
7512 | } | |
7513 | ||
7514 | static int pmu_dev_alloc(struct pmu *pmu) | |
7515 | { | |
7516 | int ret = -ENOMEM; | |
7517 | ||
7518 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7519 | if (!pmu->dev) | |
7520 | goto out; | |
7521 | ||
0c9d42ed | 7522 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7523 | device_initialize(pmu->dev); |
7524 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7525 | if (ret) | |
7526 | goto free_dev; | |
7527 | ||
7528 | dev_set_drvdata(pmu->dev, pmu); | |
7529 | pmu->dev->bus = &pmu_bus; | |
7530 | pmu->dev->release = pmu_dev_release; | |
7531 | ret = device_add(pmu->dev); | |
7532 | if (ret) | |
7533 | goto free_dev; | |
7534 | ||
7535 | out: | |
7536 | return ret; | |
7537 | ||
7538 | free_dev: | |
7539 | put_device(pmu->dev); | |
7540 | goto out; | |
7541 | } | |
7542 | ||
547e9fd7 | 7543 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7544 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7545 | |
03d8e80b | 7546 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7547 | { |
108b02cf | 7548 | int cpu, ret; |
24f1e32c | 7549 | |
b0a873eb | 7550 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7551 | ret = -ENOMEM; |
7552 | pmu->pmu_disable_count = alloc_percpu(int); | |
7553 | if (!pmu->pmu_disable_count) | |
7554 | goto unlock; | |
f29ac756 | 7555 | |
2e80a82a PZ |
7556 | pmu->type = -1; |
7557 | if (!name) | |
7558 | goto skip_type; | |
7559 | pmu->name = name; | |
7560 | ||
7561 | if (type < 0) { | |
0e9c3be2 TH |
7562 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7563 | if (type < 0) { | |
7564 | ret = type; | |
2e80a82a PZ |
7565 | goto free_pdc; |
7566 | } | |
7567 | } | |
7568 | pmu->type = type; | |
7569 | ||
abe43400 PZ |
7570 | if (pmu_bus_running) { |
7571 | ret = pmu_dev_alloc(pmu); | |
7572 | if (ret) | |
7573 | goto free_idr; | |
7574 | } | |
7575 | ||
2e80a82a | 7576 | skip_type: |
8dc85d54 PZ |
7577 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7578 | if (pmu->pmu_cpu_context) | |
7579 | goto got_cpu_context; | |
f29ac756 | 7580 | |
c4814202 | 7581 | ret = -ENOMEM; |
108b02cf PZ |
7582 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7583 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7584 | goto free_dev; |
f344011c | 7585 | |
108b02cf PZ |
7586 | for_each_possible_cpu(cpu) { |
7587 | struct perf_cpu_context *cpuctx; | |
7588 | ||
7589 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7590 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7591 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7592 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7593 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7594 | |
272325c4 | 7595 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7596 | |
3f1f3320 | 7597 | cpuctx->unique_pmu = pmu; |
108b02cf | 7598 | } |
76e1d904 | 7599 | |
8dc85d54 | 7600 | got_cpu_context: |
ad5133b7 PZ |
7601 | if (!pmu->start_txn) { |
7602 | if (pmu->pmu_enable) { | |
7603 | /* | |
7604 | * If we have pmu_enable/pmu_disable calls, install | |
7605 | * transaction stubs that use that to try and batch | |
7606 | * hardware accesses. | |
7607 | */ | |
7608 | pmu->start_txn = perf_pmu_start_txn; | |
7609 | pmu->commit_txn = perf_pmu_commit_txn; | |
7610 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7611 | } else { | |
fbbe0701 | 7612 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7613 | pmu->commit_txn = perf_pmu_nop_int; |
7614 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7615 | } |
5c92d124 | 7616 | } |
15dbf27c | 7617 | |
ad5133b7 PZ |
7618 | if (!pmu->pmu_enable) { |
7619 | pmu->pmu_enable = perf_pmu_nop_void; | |
7620 | pmu->pmu_disable = perf_pmu_nop_void; | |
7621 | } | |
7622 | ||
35edc2a5 PZ |
7623 | if (!pmu->event_idx) |
7624 | pmu->event_idx = perf_event_idx_default; | |
7625 | ||
b0a873eb | 7626 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7627 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7628 | ret = 0; |
7629 | unlock: | |
b0a873eb PZ |
7630 | mutex_unlock(&pmus_lock); |
7631 | ||
33696fc0 | 7632 | return ret; |
108b02cf | 7633 | |
abe43400 PZ |
7634 | free_dev: |
7635 | device_del(pmu->dev); | |
7636 | put_device(pmu->dev); | |
7637 | ||
2e80a82a PZ |
7638 | free_idr: |
7639 | if (pmu->type >= PERF_TYPE_MAX) | |
7640 | idr_remove(&pmu_idr, pmu->type); | |
7641 | ||
108b02cf PZ |
7642 | free_pdc: |
7643 | free_percpu(pmu->pmu_disable_count); | |
7644 | goto unlock; | |
f29ac756 | 7645 | } |
c464c76e | 7646 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7647 | |
b0a873eb | 7648 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7649 | { |
b0a873eb PZ |
7650 | mutex_lock(&pmus_lock); |
7651 | list_del_rcu(&pmu->entry); | |
7652 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7653 | |
0475f9ea | 7654 | /* |
cde8e884 PZ |
7655 | * We dereference the pmu list under both SRCU and regular RCU, so |
7656 | * synchronize against both of those. | |
0475f9ea | 7657 | */ |
b0a873eb | 7658 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7659 | synchronize_rcu(); |
d6d020e9 | 7660 | |
33696fc0 | 7661 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7662 | if (pmu->type >= PERF_TYPE_MAX) |
7663 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7664 | device_del(pmu->dev); |
7665 | put_device(pmu->dev); | |
51676957 | 7666 | free_pmu_context(pmu); |
b0a873eb | 7667 | } |
c464c76e | 7668 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7669 | |
cc34b98b MR |
7670 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7671 | { | |
ccd41c86 | 7672 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7673 | int ret; |
7674 | ||
7675 | if (!try_module_get(pmu->module)) | |
7676 | return -ENODEV; | |
ccd41c86 PZ |
7677 | |
7678 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7679 | /* |
7680 | * This ctx->mutex can nest when we're called through | |
7681 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7682 | */ | |
7683 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7684 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7685 | BUG_ON(!ctx); |
7686 | } | |
7687 | ||
cc34b98b MR |
7688 | event->pmu = pmu; |
7689 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7690 | |
7691 | if (ctx) | |
7692 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7693 | ||
cc34b98b MR |
7694 | if (ret) |
7695 | module_put(pmu->module); | |
7696 | ||
7697 | return ret; | |
7698 | } | |
7699 | ||
18ab2cd3 | 7700 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7701 | { |
7702 | struct pmu *pmu = NULL; | |
7703 | int idx; | |
940c5b29 | 7704 | int ret; |
b0a873eb PZ |
7705 | |
7706 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7707 | |
7708 | rcu_read_lock(); | |
7709 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7710 | rcu_read_unlock(); | |
940c5b29 | 7711 | if (pmu) { |
cc34b98b | 7712 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7713 | if (ret) |
7714 | pmu = ERR_PTR(ret); | |
2e80a82a | 7715 | goto unlock; |
940c5b29 | 7716 | } |
2e80a82a | 7717 | |
b0a873eb | 7718 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7719 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7720 | if (!ret) |
e5f4d339 | 7721 | goto unlock; |
76e1d904 | 7722 | |
b0a873eb PZ |
7723 | if (ret != -ENOENT) { |
7724 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7725 | goto unlock; |
f344011c | 7726 | } |
5c92d124 | 7727 | } |
e5f4d339 PZ |
7728 | pmu = ERR_PTR(-ENOENT); |
7729 | unlock: | |
b0a873eb | 7730 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7731 | |
4aeb0b42 | 7732 | return pmu; |
5c92d124 IM |
7733 | } |
7734 | ||
4beb31f3 FW |
7735 | static void account_event_cpu(struct perf_event *event, int cpu) |
7736 | { | |
7737 | if (event->parent) | |
7738 | return; | |
7739 | ||
4beb31f3 FW |
7740 | if (is_cgroup_event(event)) |
7741 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7742 | } | |
7743 | ||
766d6c07 FW |
7744 | static void account_event(struct perf_event *event) |
7745 | { | |
25432ae9 PZ |
7746 | bool inc = false; |
7747 | ||
4beb31f3 FW |
7748 | if (event->parent) |
7749 | return; | |
7750 | ||
766d6c07 | 7751 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7752 | inc = true; |
766d6c07 FW |
7753 | if (event->attr.mmap || event->attr.mmap_data) |
7754 | atomic_inc(&nr_mmap_events); | |
7755 | if (event->attr.comm) | |
7756 | atomic_inc(&nr_comm_events); | |
7757 | if (event->attr.task) | |
7758 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7759 | if (event->attr.freq) { |
7760 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7761 | tick_nohz_full_kick_all(); | |
7762 | } | |
45ac1403 AH |
7763 | if (event->attr.context_switch) { |
7764 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7765 | inc = true; |
45ac1403 | 7766 | } |
4beb31f3 | 7767 | if (has_branch_stack(event)) |
25432ae9 | 7768 | inc = true; |
4beb31f3 | 7769 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7770 | inc = true; |
7771 | ||
7772 | if (inc) | |
766d6c07 | 7773 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7774 | |
7775 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7776 | } |
7777 | ||
0793a61d | 7778 | /* |
cdd6c482 | 7779 | * Allocate and initialize a event structure |
0793a61d | 7780 | */ |
cdd6c482 | 7781 | static struct perf_event * |
c3f00c70 | 7782 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7783 | struct task_struct *task, |
7784 | struct perf_event *group_leader, | |
7785 | struct perf_event *parent_event, | |
4dc0da86 | 7786 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7787 | void *context, int cgroup_fd) |
0793a61d | 7788 | { |
51b0fe39 | 7789 | struct pmu *pmu; |
cdd6c482 IM |
7790 | struct perf_event *event; |
7791 | struct hw_perf_event *hwc; | |
90983b16 | 7792 | long err = -EINVAL; |
0793a61d | 7793 | |
66832eb4 ON |
7794 | if ((unsigned)cpu >= nr_cpu_ids) { |
7795 | if (!task || cpu != -1) | |
7796 | return ERR_PTR(-EINVAL); | |
7797 | } | |
7798 | ||
c3f00c70 | 7799 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7800 | if (!event) |
d5d2bc0d | 7801 | return ERR_PTR(-ENOMEM); |
0793a61d | 7802 | |
04289bb9 | 7803 | /* |
cdd6c482 | 7804 | * Single events are their own group leaders, with an |
04289bb9 IM |
7805 | * empty sibling list: |
7806 | */ | |
7807 | if (!group_leader) | |
cdd6c482 | 7808 | group_leader = event; |
04289bb9 | 7809 | |
cdd6c482 IM |
7810 | mutex_init(&event->child_mutex); |
7811 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7812 | |
cdd6c482 IM |
7813 | INIT_LIST_HEAD(&event->group_entry); |
7814 | INIT_LIST_HEAD(&event->event_entry); | |
7815 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7816 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7817 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7818 | INIT_HLIST_NODE(&event->hlist_entry); |
7819 | ||
10c6db11 | 7820 | |
cdd6c482 | 7821 | init_waitqueue_head(&event->waitq); |
e360adbe | 7822 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7823 | |
cdd6c482 | 7824 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7825 | |
a6fa941d | 7826 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7827 | event->cpu = cpu; |
7828 | event->attr = *attr; | |
7829 | event->group_leader = group_leader; | |
7830 | event->pmu = NULL; | |
cdd6c482 | 7831 | event->oncpu = -1; |
a96bbc16 | 7832 | |
cdd6c482 | 7833 | event->parent = parent_event; |
b84fbc9f | 7834 | |
17cf22c3 | 7835 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7836 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7837 | |
cdd6c482 | 7838 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7839 | |
d580ff86 PZ |
7840 | if (task) { |
7841 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7842 | /* |
50f16a8b PZ |
7843 | * XXX pmu::event_init needs to know what task to account to |
7844 | * and we cannot use the ctx information because we need the | |
7845 | * pmu before we get a ctx. | |
d580ff86 | 7846 | */ |
50f16a8b | 7847 | event->hw.target = task; |
d580ff86 PZ |
7848 | } |
7849 | ||
34f43927 PZ |
7850 | event->clock = &local_clock; |
7851 | if (parent_event) | |
7852 | event->clock = parent_event->clock; | |
7853 | ||
4dc0da86 | 7854 | if (!overflow_handler && parent_event) { |
b326e956 | 7855 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7856 | context = parent_event->overflow_handler_context; |
7857 | } | |
66832eb4 | 7858 | |
b326e956 | 7859 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7860 | event->overflow_handler_context = context; |
97eaf530 | 7861 | |
0231bb53 | 7862 | perf_event__state_init(event); |
a86ed508 | 7863 | |
4aeb0b42 | 7864 | pmu = NULL; |
b8e83514 | 7865 | |
cdd6c482 | 7866 | hwc = &event->hw; |
bd2b5b12 | 7867 | hwc->sample_period = attr->sample_period; |
0d48696f | 7868 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7869 | hwc->sample_period = 1; |
eced1dfc | 7870 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7871 | |
e7850595 | 7872 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7873 | |
2023b359 | 7874 | /* |
cdd6c482 | 7875 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7876 | */ |
3dab77fb | 7877 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7878 | goto err_ns; |
a46a2300 YZ |
7879 | |
7880 | if (!has_branch_stack(event)) | |
7881 | event->attr.branch_sample_type = 0; | |
2023b359 | 7882 | |
79dff51e MF |
7883 | if (cgroup_fd != -1) { |
7884 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7885 | if (err) | |
7886 | goto err_ns; | |
7887 | } | |
7888 | ||
b0a873eb | 7889 | pmu = perf_init_event(event); |
4aeb0b42 | 7890 | if (!pmu) |
90983b16 FW |
7891 | goto err_ns; |
7892 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7893 | err = PTR_ERR(pmu); |
90983b16 | 7894 | goto err_ns; |
621a01ea | 7895 | } |
d5d2bc0d | 7896 | |
bed5b25a AS |
7897 | err = exclusive_event_init(event); |
7898 | if (err) | |
7899 | goto err_pmu; | |
7900 | ||
cdd6c482 | 7901 | if (!event->parent) { |
927c7a9e FW |
7902 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7903 | err = get_callchain_buffers(); | |
90983b16 | 7904 | if (err) |
bed5b25a | 7905 | goto err_per_task; |
d010b332 | 7906 | } |
f344011c | 7907 | } |
9ee318a7 | 7908 | |
cdd6c482 | 7909 | return event; |
90983b16 | 7910 | |
bed5b25a AS |
7911 | err_per_task: |
7912 | exclusive_event_destroy(event); | |
7913 | ||
90983b16 FW |
7914 | err_pmu: |
7915 | if (event->destroy) | |
7916 | event->destroy(event); | |
c464c76e | 7917 | module_put(pmu->module); |
90983b16 | 7918 | err_ns: |
79dff51e MF |
7919 | if (is_cgroup_event(event)) |
7920 | perf_detach_cgroup(event); | |
90983b16 FW |
7921 | if (event->ns) |
7922 | put_pid_ns(event->ns); | |
7923 | kfree(event); | |
7924 | ||
7925 | return ERR_PTR(err); | |
0793a61d TG |
7926 | } |
7927 | ||
cdd6c482 IM |
7928 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7929 | struct perf_event_attr *attr) | |
974802ea | 7930 | { |
974802ea | 7931 | u32 size; |
cdf8073d | 7932 | int ret; |
974802ea PZ |
7933 | |
7934 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7935 | return -EFAULT; | |
7936 | ||
7937 | /* | |
7938 | * zero the full structure, so that a short copy will be nice. | |
7939 | */ | |
7940 | memset(attr, 0, sizeof(*attr)); | |
7941 | ||
7942 | ret = get_user(size, &uattr->size); | |
7943 | if (ret) | |
7944 | return ret; | |
7945 | ||
7946 | if (size > PAGE_SIZE) /* silly large */ | |
7947 | goto err_size; | |
7948 | ||
7949 | if (!size) /* abi compat */ | |
7950 | size = PERF_ATTR_SIZE_VER0; | |
7951 | ||
7952 | if (size < PERF_ATTR_SIZE_VER0) | |
7953 | goto err_size; | |
7954 | ||
7955 | /* | |
7956 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7957 | * ensure all the unknown bits are 0 - i.e. new |
7958 | * user-space does not rely on any kernel feature | |
7959 | * extensions we dont know about yet. | |
974802ea PZ |
7960 | */ |
7961 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7962 | unsigned char __user *addr; |
7963 | unsigned char __user *end; | |
7964 | unsigned char val; | |
974802ea | 7965 | |
cdf8073d IS |
7966 | addr = (void __user *)uattr + sizeof(*attr); |
7967 | end = (void __user *)uattr + size; | |
974802ea | 7968 | |
cdf8073d | 7969 | for (; addr < end; addr++) { |
974802ea PZ |
7970 | ret = get_user(val, addr); |
7971 | if (ret) | |
7972 | return ret; | |
7973 | if (val) | |
7974 | goto err_size; | |
7975 | } | |
b3e62e35 | 7976 | size = sizeof(*attr); |
974802ea PZ |
7977 | } |
7978 | ||
7979 | ret = copy_from_user(attr, uattr, size); | |
7980 | if (ret) | |
7981 | return -EFAULT; | |
7982 | ||
cd757645 | 7983 | if (attr->__reserved_1) |
974802ea PZ |
7984 | return -EINVAL; |
7985 | ||
7986 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7987 | return -EINVAL; | |
7988 | ||
7989 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
7990 | return -EINVAL; | |
7991 | ||
bce38cd5 SE |
7992 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
7993 | u64 mask = attr->branch_sample_type; | |
7994 | ||
7995 | /* only using defined bits */ | |
7996 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
7997 | return -EINVAL; | |
7998 | ||
7999 | /* at least one branch bit must be set */ | |
8000 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8001 | return -EINVAL; | |
8002 | ||
bce38cd5 SE |
8003 | /* propagate priv level, when not set for branch */ |
8004 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8005 | ||
8006 | /* exclude_kernel checked on syscall entry */ | |
8007 | if (!attr->exclude_kernel) | |
8008 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8009 | ||
8010 | if (!attr->exclude_user) | |
8011 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8012 | ||
8013 | if (!attr->exclude_hv) | |
8014 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8015 | /* | |
8016 | * adjust user setting (for HW filter setup) | |
8017 | */ | |
8018 | attr->branch_sample_type = mask; | |
8019 | } | |
e712209a SE |
8020 | /* privileged levels capture (kernel, hv): check permissions */ |
8021 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8022 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8023 | return -EACCES; | |
bce38cd5 | 8024 | } |
4018994f | 8025 | |
c5ebcedb | 8026 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8027 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8028 | if (ret) |
8029 | return ret; | |
8030 | } | |
8031 | ||
8032 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8033 | if (!arch_perf_have_user_stack_dump()) | |
8034 | return -ENOSYS; | |
8035 | ||
8036 | /* | |
8037 | * We have __u32 type for the size, but so far | |
8038 | * we can only use __u16 as maximum due to the | |
8039 | * __u16 sample size limit. | |
8040 | */ | |
8041 | if (attr->sample_stack_user >= USHRT_MAX) | |
8042 | ret = -EINVAL; | |
8043 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8044 | ret = -EINVAL; | |
8045 | } | |
4018994f | 8046 | |
60e2364e SE |
8047 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8048 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8049 | out: |
8050 | return ret; | |
8051 | ||
8052 | err_size: | |
8053 | put_user(sizeof(*attr), &uattr->size); | |
8054 | ret = -E2BIG; | |
8055 | goto out; | |
8056 | } | |
8057 | ||
ac9721f3 PZ |
8058 | static int |
8059 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8060 | { |
b69cf536 | 8061 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8062 | int ret = -EINVAL; |
8063 | ||
ac9721f3 | 8064 | if (!output_event) |
a4be7c27 PZ |
8065 | goto set; |
8066 | ||
ac9721f3 PZ |
8067 | /* don't allow circular references */ |
8068 | if (event == output_event) | |
a4be7c27 PZ |
8069 | goto out; |
8070 | ||
0f139300 PZ |
8071 | /* |
8072 | * Don't allow cross-cpu buffers | |
8073 | */ | |
8074 | if (output_event->cpu != event->cpu) | |
8075 | goto out; | |
8076 | ||
8077 | /* | |
76369139 | 8078 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8079 | */ |
8080 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8081 | goto out; | |
8082 | ||
34f43927 PZ |
8083 | /* |
8084 | * Mixing clocks in the same buffer is trouble you don't need. | |
8085 | */ | |
8086 | if (output_event->clock != event->clock) | |
8087 | goto out; | |
8088 | ||
45bfb2e5 PZ |
8089 | /* |
8090 | * If both events generate aux data, they must be on the same PMU | |
8091 | */ | |
8092 | if (has_aux(event) && has_aux(output_event) && | |
8093 | event->pmu != output_event->pmu) | |
8094 | goto out; | |
8095 | ||
a4be7c27 | 8096 | set: |
cdd6c482 | 8097 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8098 | /* Can't redirect output if we've got an active mmap() */ |
8099 | if (atomic_read(&event->mmap_count)) | |
8100 | goto unlock; | |
a4be7c27 | 8101 | |
ac9721f3 | 8102 | if (output_event) { |
76369139 FW |
8103 | /* get the rb we want to redirect to */ |
8104 | rb = ring_buffer_get(output_event); | |
8105 | if (!rb) | |
ac9721f3 | 8106 | goto unlock; |
a4be7c27 PZ |
8107 | } |
8108 | ||
b69cf536 | 8109 | ring_buffer_attach(event, rb); |
9bb5d40c | 8110 | |
a4be7c27 | 8111 | ret = 0; |
ac9721f3 PZ |
8112 | unlock: |
8113 | mutex_unlock(&event->mmap_mutex); | |
8114 | ||
a4be7c27 | 8115 | out: |
a4be7c27 PZ |
8116 | return ret; |
8117 | } | |
8118 | ||
f63a8daa PZ |
8119 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8120 | { | |
8121 | if (b < a) | |
8122 | swap(a, b); | |
8123 | ||
8124 | mutex_lock(a); | |
8125 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8126 | } | |
8127 | ||
34f43927 PZ |
8128 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8129 | { | |
8130 | bool nmi_safe = false; | |
8131 | ||
8132 | switch (clk_id) { | |
8133 | case CLOCK_MONOTONIC: | |
8134 | event->clock = &ktime_get_mono_fast_ns; | |
8135 | nmi_safe = true; | |
8136 | break; | |
8137 | ||
8138 | case CLOCK_MONOTONIC_RAW: | |
8139 | event->clock = &ktime_get_raw_fast_ns; | |
8140 | nmi_safe = true; | |
8141 | break; | |
8142 | ||
8143 | case CLOCK_REALTIME: | |
8144 | event->clock = &ktime_get_real_ns; | |
8145 | break; | |
8146 | ||
8147 | case CLOCK_BOOTTIME: | |
8148 | event->clock = &ktime_get_boot_ns; | |
8149 | break; | |
8150 | ||
8151 | case CLOCK_TAI: | |
8152 | event->clock = &ktime_get_tai_ns; | |
8153 | break; | |
8154 | ||
8155 | default: | |
8156 | return -EINVAL; | |
8157 | } | |
8158 | ||
8159 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8160 | return -EINVAL; | |
8161 | ||
8162 | return 0; | |
8163 | } | |
8164 | ||
0793a61d | 8165 | /** |
cdd6c482 | 8166 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8167 | * |
cdd6c482 | 8168 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8169 | * @pid: target pid |
9f66a381 | 8170 | * @cpu: target cpu |
cdd6c482 | 8171 | * @group_fd: group leader event fd |
0793a61d | 8172 | */ |
cdd6c482 IM |
8173 | SYSCALL_DEFINE5(perf_event_open, |
8174 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8175 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8176 | { |
b04243ef PZ |
8177 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8178 | struct perf_event *event, *sibling; | |
cdd6c482 | 8179 | struct perf_event_attr attr; |
f63a8daa | 8180 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8181 | struct file *event_file = NULL; |
2903ff01 | 8182 | struct fd group = {NULL, 0}; |
38a81da2 | 8183 | struct task_struct *task = NULL; |
89a1e187 | 8184 | struct pmu *pmu; |
ea635c64 | 8185 | int event_fd; |
b04243ef | 8186 | int move_group = 0; |
dc86cabe | 8187 | int err; |
a21b0b35 | 8188 | int f_flags = O_RDWR; |
79dff51e | 8189 | int cgroup_fd = -1; |
0793a61d | 8190 | |
2743a5b0 | 8191 | /* for future expandability... */ |
e5d1367f | 8192 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8193 | return -EINVAL; |
8194 | ||
dc86cabe IM |
8195 | err = perf_copy_attr(attr_uptr, &attr); |
8196 | if (err) | |
8197 | return err; | |
eab656ae | 8198 | |
0764771d PZ |
8199 | if (!attr.exclude_kernel) { |
8200 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8201 | return -EACCES; | |
8202 | } | |
8203 | ||
df58ab24 | 8204 | if (attr.freq) { |
cdd6c482 | 8205 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8206 | return -EINVAL; |
0819b2e3 PZ |
8207 | } else { |
8208 | if (attr.sample_period & (1ULL << 63)) | |
8209 | return -EINVAL; | |
df58ab24 PZ |
8210 | } |
8211 | ||
e5d1367f SE |
8212 | /* |
8213 | * In cgroup mode, the pid argument is used to pass the fd | |
8214 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8215 | * designates the cpu on which to monitor threads from that | |
8216 | * cgroup. | |
8217 | */ | |
8218 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8219 | return -EINVAL; | |
8220 | ||
a21b0b35 YD |
8221 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8222 | f_flags |= O_CLOEXEC; | |
8223 | ||
8224 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8225 | if (event_fd < 0) |
8226 | return event_fd; | |
8227 | ||
ac9721f3 | 8228 | if (group_fd != -1) { |
2903ff01 AV |
8229 | err = perf_fget_light(group_fd, &group); |
8230 | if (err) | |
d14b12d7 | 8231 | goto err_fd; |
2903ff01 | 8232 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8233 | if (flags & PERF_FLAG_FD_OUTPUT) |
8234 | output_event = group_leader; | |
8235 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8236 | group_leader = NULL; | |
8237 | } | |
8238 | ||
e5d1367f | 8239 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8240 | task = find_lively_task_by_vpid(pid); |
8241 | if (IS_ERR(task)) { | |
8242 | err = PTR_ERR(task); | |
8243 | goto err_group_fd; | |
8244 | } | |
8245 | } | |
8246 | ||
1f4ee503 PZ |
8247 | if (task && group_leader && |
8248 | group_leader->attr.inherit != attr.inherit) { | |
8249 | err = -EINVAL; | |
8250 | goto err_task; | |
8251 | } | |
8252 | ||
fbfc623f YZ |
8253 | get_online_cpus(); |
8254 | ||
79dff51e MF |
8255 | if (flags & PERF_FLAG_PID_CGROUP) |
8256 | cgroup_fd = pid; | |
8257 | ||
4dc0da86 | 8258 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8259 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8260 | if (IS_ERR(event)) { |
8261 | err = PTR_ERR(event); | |
1f4ee503 | 8262 | goto err_cpus; |
d14b12d7 SE |
8263 | } |
8264 | ||
53b25335 VW |
8265 | if (is_sampling_event(event)) { |
8266 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8267 | err = -ENOTSUPP; | |
8268 | goto err_alloc; | |
8269 | } | |
8270 | } | |
8271 | ||
766d6c07 FW |
8272 | account_event(event); |
8273 | ||
89a1e187 PZ |
8274 | /* |
8275 | * Special case software events and allow them to be part of | |
8276 | * any hardware group. | |
8277 | */ | |
8278 | pmu = event->pmu; | |
b04243ef | 8279 | |
34f43927 PZ |
8280 | if (attr.use_clockid) { |
8281 | err = perf_event_set_clock(event, attr.clockid); | |
8282 | if (err) | |
8283 | goto err_alloc; | |
8284 | } | |
8285 | ||
b04243ef PZ |
8286 | if (group_leader && |
8287 | (is_software_event(event) != is_software_event(group_leader))) { | |
8288 | if (is_software_event(event)) { | |
8289 | /* | |
8290 | * If event and group_leader are not both a software | |
8291 | * event, and event is, then group leader is not. | |
8292 | * | |
8293 | * Allow the addition of software events to !software | |
8294 | * groups, this is safe because software events never | |
8295 | * fail to schedule. | |
8296 | */ | |
8297 | pmu = group_leader->pmu; | |
8298 | } else if (is_software_event(group_leader) && | |
8299 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8300 | /* | |
8301 | * In case the group is a pure software group, and we | |
8302 | * try to add a hardware event, move the whole group to | |
8303 | * the hardware context. | |
8304 | */ | |
8305 | move_group = 1; | |
8306 | } | |
8307 | } | |
89a1e187 PZ |
8308 | |
8309 | /* | |
8310 | * Get the target context (task or percpu): | |
8311 | */ | |
4af57ef2 | 8312 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8313 | if (IS_ERR(ctx)) { |
8314 | err = PTR_ERR(ctx); | |
c6be5a5c | 8315 | goto err_alloc; |
89a1e187 PZ |
8316 | } |
8317 | ||
bed5b25a AS |
8318 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8319 | err = -EBUSY; | |
8320 | goto err_context; | |
8321 | } | |
8322 | ||
fd1edb3a PZ |
8323 | if (task) { |
8324 | put_task_struct(task); | |
8325 | task = NULL; | |
8326 | } | |
8327 | ||
ccff286d | 8328 | /* |
cdd6c482 | 8329 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8330 | */ |
ac9721f3 | 8331 | if (group_leader) { |
dc86cabe | 8332 | err = -EINVAL; |
04289bb9 | 8333 | |
04289bb9 | 8334 | /* |
ccff286d IM |
8335 | * Do not allow a recursive hierarchy (this new sibling |
8336 | * becoming part of another group-sibling): | |
8337 | */ | |
8338 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8339 | goto err_context; |
34f43927 PZ |
8340 | |
8341 | /* All events in a group should have the same clock */ | |
8342 | if (group_leader->clock != event->clock) | |
8343 | goto err_context; | |
8344 | ||
ccff286d IM |
8345 | /* |
8346 | * Do not allow to attach to a group in a different | |
8347 | * task or CPU context: | |
04289bb9 | 8348 | */ |
b04243ef | 8349 | if (move_group) { |
c3c87e77 PZ |
8350 | /* |
8351 | * Make sure we're both on the same task, or both | |
8352 | * per-cpu events. | |
8353 | */ | |
8354 | if (group_leader->ctx->task != ctx->task) | |
8355 | goto err_context; | |
8356 | ||
8357 | /* | |
8358 | * Make sure we're both events for the same CPU; | |
8359 | * grouping events for different CPUs is broken; since | |
8360 | * you can never concurrently schedule them anyhow. | |
8361 | */ | |
8362 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8363 | goto err_context; |
8364 | } else { | |
8365 | if (group_leader->ctx != ctx) | |
8366 | goto err_context; | |
8367 | } | |
8368 | ||
3b6f9e5c PM |
8369 | /* |
8370 | * Only a group leader can be exclusive or pinned | |
8371 | */ | |
0d48696f | 8372 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8373 | goto err_context; |
ac9721f3 PZ |
8374 | } |
8375 | ||
8376 | if (output_event) { | |
8377 | err = perf_event_set_output(event, output_event); | |
8378 | if (err) | |
c3f00c70 | 8379 | goto err_context; |
ac9721f3 | 8380 | } |
0793a61d | 8381 | |
a21b0b35 YD |
8382 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8383 | f_flags); | |
ea635c64 AV |
8384 | if (IS_ERR(event_file)) { |
8385 | err = PTR_ERR(event_file); | |
c3f00c70 | 8386 | goto err_context; |
ea635c64 | 8387 | } |
9b51f66d | 8388 | |
b04243ef | 8389 | if (move_group) { |
f63a8daa | 8390 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8391 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8392 | } else { | |
8393 | mutex_lock(&ctx->mutex); | |
8394 | } | |
8395 | ||
a723968c PZ |
8396 | if (!perf_event_validate_size(event)) { |
8397 | err = -E2BIG; | |
8398 | goto err_locked; | |
8399 | } | |
8400 | ||
f55fc2a5 PZ |
8401 | /* |
8402 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8403 | * because we need to serialize with concurrent event creation. | |
8404 | */ | |
8405 | if (!exclusive_event_installable(event, ctx)) { | |
8406 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8407 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8408 | |
f55fc2a5 PZ |
8409 | err = -EBUSY; |
8410 | goto err_locked; | |
8411 | } | |
f63a8daa | 8412 | |
f55fc2a5 PZ |
8413 | WARN_ON_ONCE(ctx->parent_ctx); |
8414 | ||
8415 | if (move_group) { | |
f63a8daa PZ |
8416 | /* |
8417 | * See perf_event_ctx_lock() for comments on the details | |
8418 | * of swizzling perf_event::ctx. | |
8419 | */ | |
45a0e07a | 8420 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8421 | |
b04243ef PZ |
8422 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8423 | group_entry) { | |
45a0e07a | 8424 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8425 | put_ctx(gctx); |
8426 | } | |
b04243ef | 8427 | |
f63a8daa PZ |
8428 | /* |
8429 | * Wait for everybody to stop referencing the events through | |
8430 | * the old lists, before installing it on new lists. | |
8431 | */ | |
0cda4c02 | 8432 | synchronize_rcu(); |
f63a8daa | 8433 | |
8f95b435 PZI |
8434 | /* |
8435 | * Install the group siblings before the group leader. | |
8436 | * | |
8437 | * Because a group leader will try and install the entire group | |
8438 | * (through the sibling list, which is still in-tact), we can | |
8439 | * end up with siblings installed in the wrong context. | |
8440 | * | |
8441 | * By installing siblings first we NO-OP because they're not | |
8442 | * reachable through the group lists. | |
8443 | */ | |
b04243ef PZ |
8444 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8445 | group_entry) { | |
8f95b435 | 8446 | perf_event__state_init(sibling); |
9fc81d87 | 8447 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8448 | get_ctx(ctx); |
8449 | } | |
8f95b435 PZI |
8450 | |
8451 | /* | |
8452 | * Removing from the context ends up with disabled | |
8453 | * event. What we want here is event in the initial | |
8454 | * startup state, ready to be add into new context. | |
8455 | */ | |
8456 | perf_event__state_init(group_leader); | |
8457 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8458 | get_ctx(ctx); | |
b04243ef | 8459 | |
f55fc2a5 PZ |
8460 | /* |
8461 | * Now that all events are installed in @ctx, nothing | |
8462 | * references @gctx anymore, so drop the last reference we have | |
8463 | * on it. | |
8464 | */ | |
8465 | put_ctx(gctx); | |
bed5b25a AS |
8466 | } |
8467 | ||
f73e22ab PZ |
8468 | /* |
8469 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8470 | * that we're serialized against further additions and before | |
8471 | * perf_install_in_context() which is the point the event is active and | |
8472 | * can use these values. | |
8473 | */ | |
8474 | perf_event__header_size(event); | |
8475 | perf_event__id_header_size(event); | |
8476 | ||
78cd2c74 PZ |
8477 | event->owner = current; |
8478 | ||
e2d37cd2 | 8479 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8480 | perf_unpin_context(ctx); |
f63a8daa | 8481 | |
f55fc2a5 | 8482 | if (move_group) |
f63a8daa | 8483 | mutex_unlock(&gctx->mutex); |
d859e29f | 8484 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8485 | |
fbfc623f YZ |
8486 | put_online_cpus(); |
8487 | ||
cdd6c482 IM |
8488 | mutex_lock(¤t->perf_event_mutex); |
8489 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8490 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8491 | |
8a49542c PZ |
8492 | /* |
8493 | * Drop the reference on the group_event after placing the | |
8494 | * new event on the sibling_list. This ensures destruction | |
8495 | * of the group leader will find the pointer to itself in | |
8496 | * perf_group_detach(). | |
8497 | */ | |
2903ff01 | 8498 | fdput(group); |
ea635c64 AV |
8499 | fd_install(event_fd, event_file); |
8500 | return event_fd; | |
0793a61d | 8501 | |
f55fc2a5 PZ |
8502 | err_locked: |
8503 | if (move_group) | |
8504 | mutex_unlock(&gctx->mutex); | |
8505 | mutex_unlock(&ctx->mutex); | |
8506 | /* err_file: */ | |
8507 | fput(event_file); | |
c3f00c70 | 8508 | err_context: |
fe4b04fa | 8509 | perf_unpin_context(ctx); |
ea635c64 | 8510 | put_ctx(ctx); |
c6be5a5c | 8511 | err_alloc: |
ea635c64 | 8512 | free_event(event); |
1f4ee503 | 8513 | err_cpus: |
fbfc623f | 8514 | put_online_cpus(); |
1f4ee503 | 8515 | err_task: |
e7d0bc04 PZ |
8516 | if (task) |
8517 | put_task_struct(task); | |
89a1e187 | 8518 | err_group_fd: |
2903ff01 | 8519 | fdput(group); |
ea635c64 AV |
8520 | err_fd: |
8521 | put_unused_fd(event_fd); | |
dc86cabe | 8522 | return err; |
0793a61d TG |
8523 | } |
8524 | ||
fb0459d7 AV |
8525 | /** |
8526 | * perf_event_create_kernel_counter | |
8527 | * | |
8528 | * @attr: attributes of the counter to create | |
8529 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8530 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8531 | */ |
8532 | struct perf_event * | |
8533 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8534 | struct task_struct *task, |
4dc0da86 AK |
8535 | perf_overflow_handler_t overflow_handler, |
8536 | void *context) | |
fb0459d7 | 8537 | { |
fb0459d7 | 8538 | struct perf_event_context *ctx; |
c3f00c70 | 8539 | struct perf_event *event; |
fb0459d7 | 8540 | int err; |
d859e29f | 8541 | |
fb0459d7 AV |
8542 | /* |
8543 | * Get the target context (task or percpu): | |
8544 | */ | |
d859e29f | 8545 | |
4dc0da86 | 8546 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8547 | overflow_handler, context, -1); |
c3f00c70 PZ |
8548 | if (IS_ERR(event)) { |
8549 | err = PTR_ERR(event); | |
8550 | goto err; | |
8551 | } | |
d859e29f | 8552 | |
f8697762 | 8553 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8554 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8555 | |
766d6c07 FW |
8556 | account_event(event); |
8557 | ||
4af57ef2 | 8558 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8559 | if (IS_ERR(ctx)) { |
8560 | err = PTR_ERR(ctx); | |
c3f00c70 | 8561 | goto err_free; |
d859e29f | 8562 | } |
fb0459d7 | 8563 | |
fb0459d7 AV |
8564 | WARN_ON_ONCE(ctx->parent_ctx); |
8565 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8566 | if (!exclusive_event_installable(event, ctx)) { |
8567 | mutex_unlock(&ctx->mutex); | |
8568 | perf_unpin_context(ctx); | |
8569 | put_ctx(ctx); | |
8570 | err = -EBUSY; | |
8571 | goto err_free; | |
8572 | } | |
8573 | ||
fb0459d7 | 8574 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8575 | perf_unpin_context(ctx); |
fb0459d7 AV |
8576 | mutex_unlock(&ctx->mutex); |
8577 | ||
fb0459d7 AV |
8578 | return event; |
8579 | ||
c3f00c70 PZ |
8580 | err_free: |
8581 | free_event(event); | |
8582 | err: | |
c6567f64 | 8583 | return ERR_PTR(err); |
9b51f66d | 8584 | } |
fb0459d7 | 8585 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8586 | |
0cda4c02 YZ |
8587 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8588 | { | |
8589 | struct perf_event_context *src_ctx; | |
8590 | struct perf_event_context *dst_ctx; | |
8591 | struct perf_event *event, *tmp; | |
8592 | LIST_HEAD(events); | |
8593 | ||
8594 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8595 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8596 | ||
f63a8daa PZ |
8597 | /* |
8598 | * See perf_event_ctx_lock() for comments on the details | |
8599 | * of swizzling perf_event::ctx. | |
8600 | */ | |
8601 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8602 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8603 | event_entry) { | |
45a0e07a | 8604 | perf_remove_from_context(event, 0); |
9a545de0 | 8605 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8606 | put_ctx(src_ctx); |
9886167d | 8607 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8608 | } |
0cda4c02 | 8609 | |
8f95b435 PZI |
8610 | /* |
8611 | * Wait for the events to quiesce before re-instating them. | |
8612 | */ | |
0cda4c02 YZ |
8613 | synchronize_rcu(); |
8614 | ||
8f95b435 PZI |
8615 | /* |
8616 | * Re-instate events in 2 passes. | |
8617 | * | |
8618 | * Skip over group leaders and only install siblings on this first | |
8619 | * pass, siblings will not get enabled without a leader, however a | |
8620 | * leader will enable its siblings, even if those are still on the old | |
8621 | * context. | |
8622 | */ | |
8623 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8624 | if (event->group_leader == event) | |
8625 | continue; | |
8626 | ||
8627 | list_del(&event->migrate_entry); | |
8628 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8629 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8630 | account_event_cpu(event, dst_cpu); | |
8631 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8632 | get_ctx(dst_ctx); | |
8633 | } | |
8634 | ||
8635 | /* | |
8636 | * Once all the siblings are setup properly, install the group leaders | |
8637 | * to make it go. | |
8638 | */ | |
9886167d PZ |
8639 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8640 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8641 | if (event->state >= PERF_EVENT_STATE_OFF) |
8642 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8643 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8644 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8645 | get_ctx(dst_ctx); | |
8646 | } | |
8647 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8648 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8649 | } |
8650 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8651 | ||
cdd6c482 | 8652 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8653 | struct task_struct *child) |
d859e29f | 8654 | { |
cdd6c482 | 8655 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8656 | u64 child_val; |
d859e29f | 8657 | |
cdd6c482 IM |
8658 | if (child_event->attr.inherit_stat) |
8659 | perf_event_read_event(child_event, child); | |
38b200d6 | 8660 | |
b5e58793 | 8661 | child_val = perf_event_count(child_event); |
d859e29f PM |
8662 | |
8663 | /* | |
8664 | * Add back the child's count to the parent's count: | |
8665 | */ | |
a6e6dea6 | 8666 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8667 | atomic64_add(child_event->total_time_enabled, |
8668 | &parent_event->child_total_time_enabled); | |
8669 | atomic64_add(child_event->total_time_running, | |
8670 | &parent_event->child_total_time_running); | |
d859e29f PM |
8671 | } |
8672 | ||
9b51f66d | 8673 | static void |
8ba289b8 PZ |
8674 | perf_event_exit_event(struct perf_event *child_event, |
8675 | struct perf_event_context *child_ctx, | |
8676 | struct task_struct *child) | |
9b51f66d | 8677 | { |
8ba289b8 PZ |
8678 | struct perf_event *parent_event = child_event->parent; |
8679 | ||
1903d50c PZ |
8680 | /* |
8681 | * Do not destroy the 'original' grouping; because of the context | |
8682 | * switch optimization the original events could've ended up in a | |
8683 | * random child task. | |
8684 | * | |
8685 | * If we were to destroy the original group, all group related | |
8686 | * operations would cease to function properly after this random | |
8687 | * child dies. | |
8688 | * | |
8689 | * Do destroy all inherited groups, we don't care about those | |
8690 | * and being thorough is better. | |
8691 | */ | |
32132a3d PZ |
8692 | raw_spin_lock_irq(&child_ctx->lock); |
8693 | WARN_ON_ONCE(child_ctx->is_active); | |
8694 | ||
8ba289b8 | 8695 | if (parent_event) |
32132a3d PZ |
8696 | perf_group_detach(child_event); |
8697 | list_del_event(child_event, child_ctx); | |
c6e5b732 | 8698 | child_event->state = PERF_EVENT_STATE_EXIT; /* see perf_event_release_kernel() */ |
32132a3d | 8699 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 8700 | |
9b51f66d | 8701 | /* |
8ba289b8 | 8702 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 8703 | */ |
8ba289b8 | 8704 | if (!parent_event) { |
179033b3 | 8705 | perf_event_wakeup(child_event); |
8ba289b8 | 8706 | return; |
4bcf349a | 8707 | } |
8ba289b8 PZ |
8708 | /* |
8709 | * Child events can be cleaned up. | |
8710 | */ | |
8711 | ||
8712 | sync_child_event(child_event, child); | |
8713 | ||
8714 | /* | |
8715 | * Remove this event from the parent's list | |
8716 | */ | |
8717 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8718 | mutex_lock(&parent_event->child_mutex); | |
8719 | list_del_init(&child_event->child_list); | |
8720 | mutex_unlock(&parent_event->child_mutex); | |
8721 | ||
8722 | /* | |
8723 | * Kick perf_poll() for is_event_hup(). | |
8724 | */ | |
8725 | perf_event_wakeup(parent_event); | |
8726 | free_event(child_event); | |
8727 | put_event(parent_event); | |
9b51f66d IM |
8728 | } |
8729 | ||
8dc85d54 | 8730 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8731 | { |
211de6eb | 8732 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 8733 | struct perf_event *child_event, *next; |
63b6da39 PZ |
8734 | |
8735 | WARN_ON_ONCE(child != current); | |
9b51f66d | 8736 | |
6a3351b6 | 8737 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 8738 | if (!child_ctx) |
9b51f66d IM |
8739 | return; |
8740 | ||
ad3a37de | 8741 | /* |
6a3351b6 PZ |
8742 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
8743 | * ctx::mutex over the entire thing. This serializes against almost | |
8744 | * everything that wants to access the ctx. | |
8745 | * | |
8746 | * The exception is sys_perf_event_open() / | |
8747 | * perf_event_create_kernel_count() which does find_get_context() | |
8748 | * without ctx::mutex (it cannot because of the move_group double mutex | |
8749 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 8750 | */ |
6a3351b6 | 8751 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
8752 | |
8753 | /* | |
6a3351b6 PZ |
8754 | * In a single ctx::lock section, de-schedule the events and detach the |
8755 | * context from the task such that we cannot ever get it scheduled back | |
8756 | * in. | |
c93f7669 | 8757 | */ |
6a3351b6 | 8758 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 8759 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 8760 | |
71a851b4 | 8761 | /* |
63b6da39 PZ |
8762 | * Now that the context is inactive, destroy the task <-> ctx relation |
8763 | * and mark the context dead. | |
71a851b4 | 8764 | */ |
63b6da39 PZ |
8765 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
8766 | put_ctx(child_ctx); /* cannot be last */ | |
8767 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
8768 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 8769 | |
211de6eb | 8770 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 8771 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8772 | |
211de6eb PZ |
8773 | if (clone_ctx) |
8774 | put_ctx(clone_ctx); | |
4a1c0f26 | 8775 | |
9f498cc5 | 8776 | /* |
cdd6c482 IM |
8777 | * Report the task dead after unscheduling the events so that we |
8778 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8779 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8780 | */ |
cdd6c482 | 8781 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8782 | |
ebf905fc | 8783 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 8784 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 8785 | |
a63eaf34 PM |
8786 | mutex_unlock(&child_ctx->mutex); |
8787 | ||
8788 | put_ctx(child_ctx); | |
9b51f66d IM |
8789 | } |
8790 | ||
8dc85d54 PZ |
8791 | /* |
8792 | * When a child task exits, feed back event values to parent events. | |
8793 | */ | |
8794 | void perf_event_exit_task(struct task_struct *child) | |
8795 | { | |
8882135b | 8796 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8797 | int ctxn; |
8798 | ||
8882135b PZ |
8799 | mutex_lock(&child->perf_event_mutex); |
8800 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8801 | owner_entry) { | |
8802 | list_del_init(&event->owner_entry); | |
8803 | ||
8804 | /* | |
8805 | * Ensure the list deletion is visible before we clear | |
8806 | * the owner, closes a race against perf_release() where | |
8807 | * we need to serialize on the owner->perf_event_mutex. | |
8808 | */ | |
f47c02c0 | 8809 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
8810 | } |
8811 | mutex_unlock(&child->perf_event_mutex); | |
8812 | ||
8dc85d54 PZ |
8813 | for_each_task_context_nr(ctxn) |
8814 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8815 | |
8816 | /* | |
8817 | * The perf_event_exit_task_context calls perf_event_task | |
8818 | * with child's task_ctx, which generates EXIT events for | |
8819 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8820 | * At this point we need to send EXIT events to cpu contexts. | |
8821 | */ | |
8822 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8823 | } |
8824 | ||
889ff015 FW |
8825 | static void perf_free_event(struct perf_event *event, |
8826 | struct perf_event_context *ctx) | |
8827 | { | |
8828 | struct perf_event *parent = event->parent; | |
8829 | ||
8830 | if (WARN_ON_ONCE(!parent)) | |
8831 | return; | |
8832 | ||
8833 | mutex_lock(&parent->child_mutex); | |
8834 | list_del_init(&event->child_list); | |
8835 | mutex_unlock(&parent->child_mutex); | |
8836 | ||
a6fa941d | 8837 | put_event(parent); |
889ff015 | 8838 | |
652884fe | 8839 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8840 | perf_group_detach(event); |
889ff015 | 8841 | list_del_event(event, ctx); |
652884fe | 8842 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8843 | free_event(event); |
8844 | } | |
8845 | ||
bbbee908 | 8846 | /* |
652884fe | 8847 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8848 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8849 | * |
8850 | * Not all locks are strictly required, but take them anyway to be nice and | |
8851 | * help out with the lockdep assertions. | |
bbbee908 | 8852 | */ |
cdd6c482 | 8853 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8854 | { |
8dc85d54 | 8855 | struct perf_event_context *ctx; |
cdd6c482 | 8856 | struct perf_event *event, *tmp; |
8dc85d54 | 8857 | int ctxn; |
bbbee908 | 8858 | |
8dc85d54 PZ |
8859 | for_each_task_context_nr(ctxn) { |
8860 | ctx = task->perf_event_ctxp[ctxn]; | |
8861 | if (!ctx) | |
8862 | continue; | |
bbbee908 | 8863 | |
8dc85d54 | 8864 | mutex_lock(&ctx->mutex); |
bbbee908 | 8865 | again: |
8dc85d54 PZ |
8866 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8867 | group_entry) | |
8868 | perf_free_event(event, ctx); | |
bbbee908 | 8869 | |
8dc85d54 PZ |
8870 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8871 | group_entry) | |
8872 | perf_free_event(event, ctx); | |
bbbee908 | 8873 | |
8dc85d54 PZ |
8874 | if (!list_empty(&ctx->pinned_groups) || |
8875 | !list_empty(&ctx->flexible_groups)) | |
8876 | goto again; | |
bbbee908 | 8877 | |
8dc85d54 | 8878 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8879 | |
8dc85d54 PZ |
8880 | put_ctx(ctx); |
8881 | } | |
889ff015 FW |
8882 | } |
8883 | ||
4e231c79 PZ |
8884 | void perf_event_delayed_put(struct task_struct *task) |
8885 | { | |
8886 | int ctxn; | |
8887 | ||
8888 | for_each_task_context_nr(ctxn) | |
8889 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8890 | } | |
8891 | ||
e03e7ee3 | 8892 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 8893 | { |
e03e7ee3 | 8894 | struct file *file; |
ffe8690c | 8895 | |
e03e7ee3 AS |
8896 | file = fget_raw(fd); |
8897 | if (!file) | |
8898 | return ERR_PTR(-EBADF); | |
ffe8690c | 8899 | |
e03e7ee3 AS |
8900 | if (file->f_op != &perf_fops) { |
8901 | fput(file); | |
8902 | return ERR_PTR(-EBADF); | |
8903 | } | |
ffe8690c | 8904 | |
e03e7ee3 | 8905 | return file; |
ffe8690c KX |
8906 | } |
8907 | ||
8908 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8909 | { | |
8910 | if (!event) | |
8911 | return ERR_PTR(-EINVAL); | |
8912 | ||
8913 | return &event->attr; | |
8914 | } | |
8915 | ||
97dee4f3 PZ |
8916 | /* |
8917 | * inherit a event from parent task to child task: | |
8918 | */ | |
8919 | static struct perf_event * | |
8920 | inherit_event(struct perf_event *parent_event, | |
8921 | struct task_struct *parent, | |
8922 | struct perf_event_context *parent_ctx, | |
8923 | struct task_struct *child, | |
8924 | struct perf_event *group_leader, | |
8925 | struct perf_event_context *child_ctx) | |
8926 | { | |
1929def9 | 8927 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8928 | struct perf_event *child_event; |
cee010ec | 8929 | unsigned long flags; |
97dee4f3 PZ |
8930 | |
8931 | /* | |
8932 | * Instead of creating recursive hierarchies of events, | |
8933 | * we link inherited events back to the original parent, | |
8934 | * which has a filp for sure, which we use as the reference | |
8935 | * count: | |
8936 | */ | |
8937 | if (parent_event->parent) | |
8938 | parent_event = parent_event->parent; | |
8939 | ||
8940 | child_event = perf_event_alloc(&parent_event->attr, | |
8941 | parent_event->cpu, | |
d580ff86 | 8942 | child, |
97dee4f3 | 8943 | group_leader, parent_event, |
79dff51e | 8944 | NULL, NULL, -1); |
97dee4f3 PZ |
8945 | if (IS_ERR(child_event)) |
8946 | return child_event; | |
a6fa941d | 8947 | |
c6e5b732 PZ |
8948 | /* |
8949 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
8950 | * must be under the same lock in order to serialize against | |
8951 | * perf_event_release_kernel(), such that either we must observe | |
8952 | * is_orphaned_event() or they will observe us on the child_list. | |
8953 | */ | |
8954 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
8955 | if (is_orphaned_event(parent_event) || |
8956 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 8957 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
8958 | free_event(child_event); |
8959 | return NULL; | |
8960 | } | |
8961 | ||
97dee4f3 PZ |
8962 | get_ctx(child_ctx); |
8963 | ||
8964 | /* | |
8965 | * Make the child state follow the state of the parent event, | |
8966 | * not its attr.disabled bit. We hold the parent's mutex, | |
8967 | * so we won't race with perf_event_{en, dis}able_family. | |
8968 | */ | |
1929def9 | 8969 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8970 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8971 | else | |
8972 | child_event->state = PERF_EVENT_STATE_OFF; | |
8973 | ||
8974 | if (parent_event->attr.freq) { | |
8975 | u64 sample_period = parent_event->hw.sample_period; | |
8976 | struct hw_perf_event *hwc = &child_event->hw; | |
8977 | ||
8978 | hwc->sample_period = sample_period; | |
8979 | hwc->last_period = sample_period; | |
8980 | ||
8981 | local64_set(&hwc->period_left, sample_period); | |
8982 | } | |
8983 | ||
8984 | child_event->ctx = child_ctx; | |
8985 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
8986 | child_event->overflow_handler_context |
8987 | = parent_event->overflow_handler_context; | |
97dee4f3 | 8988 | |
614b6780 TG |
8989 | /* |
8990 | * Precalculate sample_data sizes | |
8991 | */ | |
8992 | perf_event__header_size(child_event); | |
6844c09d | 8993 | perf_event__id_header_size(child_event); |
614b6780 | 8994 | |
97dee4f3 PZ |
8995 | /* |
8996 | * Link it up in the child's context: | |
8997 | */ | |
cee010ec | 8998 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 8999 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9000 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9001 | |
97dee4f3 PZ |
9002 | /* |
9003 | * Link this into the parent event's child list | |
9004 | */ | |
97dee4f3 PZ |
9005 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9006 | mutex_unlock(&parent_event->child_mutex); | |
9007 | ||
9008 | return child_event; | |
9009 | } | |
9010 | ||
9011 | static int inherit_group(struct perf_event *parent_event, | |
9012 | struct task_struct *parent, | |
9013 | struct perf_event_context *parent_ctx, | |
9014 | struct task_struct *child, | |
9015 | struct perf_event_context *child_ctx) | |
9016 | { | |
9017 | struct perf_event *leader; | |
9018 | struct perf_event *sub; | |
9019 | struct perf_event *child_ctr; | |
9020 | ||
9021 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9022 | child, NULL, child_ctx); | |
9023 | if (IS_ERR(leader)) | |
9024 | return PTR_ERR(leader); | |
9025 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9026 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9027 | child, leader, child_ctx); | |
9028 | if (IS_ERR(child_ctr)) | |
9029 | return PTR_ERR(child_ctr); | |
9030 | } | |
9031 | return 0; | |
889ff015 FW |
9032 | } |
9033 | ||
9034 | static int | |
9035 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9036 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9037 | struct task_struct *child, int ctxn, |
889ff015 FW |
9038 | int *inherited_all) |
9039 | { | |
9040 | int ret; | |
8dc85d54 | 9041 | struct perf_event_context *child_ctx; |
889ff015 FW |
9042 | |
9043 | if (!event->attr.inherit) { | |
9044 | *inherited_all = 0; | |
9045 | return 0; | |
bbbee908 PZ |
9046 | } |
9047 | ||
fe4b04fa | 9048 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9049 | if (!child_ctx) { |
9050 | /* | |
9051 | * This is executed from the parent task context, so | |
9052 | * inherit events that have been marked for cloning. | |
9053 | * First allocate and initialize a context for the | |
9054 | * child. | |
9055 | */ | |
bbbee908 | 9056 | |
734df5ab | 9057 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9058 | if (!child_ctx) |
9059 | return -ENOMEM; | |
bbbee908 | 9060 | |
8dc85d54 | 9061 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9062 | } |
9063 | ||
9064 | ret = inherit_group(event, parent, parent_ctx, | |
9065 | child, child_ctx); | |
9066 | ||
9067 | if (ret) | |
9068 | *inherited_all = 0; | |
9069 | ||
9070 | return ret; | |
bbbee908 PZ |
9071 | } |
9072 | ||
9b51f66d | 9073 | /* |
cdd6c482 | 9074 | * Initialize the perf_event context in task_struct |
9b51f66d | 9075 | */ |
985c8dcb | 9076 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9077 | { |
889ff015 | 9078 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9079 | struct perf_event_context *cloned_ctx; |
9080 | struct perf_event *event; | |
9b51f66d | 9081 | struct task_struct *parent = current; |
564c2b21 | 9082 | int inherited_all = 1; |
dddd3379 | 9083 | unsigned long flags; |
6ab423e0 | 9084 | int ret = 0; |
9b51f66d | 9085 | |
8dc85d54 | 9086 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9087 | return 0; |
9088 | ||
ad3a37de | 9089 | /* |
25346b93 PM |
9090 | * If the parent's context is a clone, pin it so it won't get |
9091 | * swapped under us. | |
ad3a37de | 9092 | */ |
8dc85d54 | 9093 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9094 | if (!parent_ctx) |
9095 | return 0; | |
25346b93 | 9096 | |
ad3a37de PM |
9097 | /* |
9098 | * No need to check if parent_ctx != NULL here; since we saw | |
9099 | * it non-NULL earlier, the only reason for it to become NULL | |
9100 | * is if we exit, and since we're currently in the middle of | |
9101 | * a fork we can't be exiting at the same time. | |
9102 | */ | |
ad3a37de | 9103 | |
9b51f66d IM |
9104 | /* |
9105 | * Lock the parent list. No need to lock the child - not PID | |
9106 | * hashed yet and not running, so nobody can access it. | |
9107 | */ | |
d859e29f | 9108 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9109 | |
9110 | /* | |
9111 | * We dont have to disable NMIs - we are only looking at | |
9112 | * the list, not manipulating it: | |
9113 | */ | |
889ff015 | 9114 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9115 | ret = inherit_task_group(event, parent, parent_ctx, |
9116 | child, ctxn, &inherited_all); | |
889ff015 FW |
9117 | if (ret) |
9118 | break; | |
9119 | } | |
b93f7978 | 9120 | |
dddd3379 TG |
9121 | /* |
9122 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9123 | * to allocations, but we need to prevent rotation because | |
9124 | * rotate_ctx() will change the list from interrupt context. | |
9125 | */ | |
9126 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9127 | parent_ctx->rotate_disable = 1; | |
9128 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9129 | ||
889ff015 | 9130 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9131 | ret = inherit_task_group(event, parent, parent_ctx, |
9132 | child, ctxn, &inherited_all); | |
889ff015 | 9133 | if (ret) |
9b51f66d | 9134 | break; |
564c2b21 PM |
9135 | } |
9136 | ||
dddd3379 TG |
9137 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9138 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9139 | |
8dc85d54 | 9140 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9141 | |
05cbaa28 | 9142 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9143 | /* |
9144 | * Mark the child context as a clone of the parent | |
9145 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9146 | * |
9147 | * Note that if the parent is a clone, the holding of | |
9148 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9149 | */ |
c5ed5145 | 9150 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9151 | if (cloned_ctx) { |
9152 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9153 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9154 | } else { |
9155 | child_ctx->parent_ctx = parent_ctx; | |
9156 | child_ctx->parent_gen = parent_ctx->generation; | |
9157 | } | |
9158 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9159 | } |
9160 | ||
c5ed5145 | 9161 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9162 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9163 | |
25346b93 | 9164 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9165 | put_ctx(parent_ctx); |
ad3a37de | 9166 | |
6ab423e0 | 9167 | return ret; |
9b51f66d IM |
9168 | } |
9169 | ||
8dc85d54 PZ |
9170 | /* |
9171 | * Initialize the perf_event context in task_struct | |
9172 | */ | |
9173 | int perf_event_init_task(struct task_struct *child) | |
9174 | { | |
9175 | int ctxn, ret; | |
9176 | ||
8550d7cb ON |
9177 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9178 | mutex_init(&child->perf_event_mutex); | |
9179 | INIT_LIST_HEAD(&child->perf_event_list); | |
9180 | ||
8dc85d54 PZ |
9181 | for_each_task_context_nr(ctxn) { |
9182 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9183 | if (ret) { |
9184 | perf_event_free_task(child); | |
8dc85d54 | 9185 | return ret; |
6c72e350 | 9186 | } |
8dc85d54 PZ |
9187 | } |
9188 | ||
9189 | return 0; | |
9190 | } | |
9191 | ||
220b140b PM |
9192 | static void __init perf_event_init_all_cpus(void) |
9193 | { | |
b28ab83c | 9194 | struct swevent_htable *swhash; |
220b140b | 9195 | int cpu; |
220b140b PM |
9196 | |
9197 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9198 | swhash = &per_cpu(swevent_htable, cpu); |
9199 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9200 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9201 | } |
9202 | } | |
9203 | ||
0db0628d | 9204 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9205 | { |
108b02cf | 9206 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9207 | |
b28ab83c | 9208 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9209 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9210 | struct swevent_hlist *hlist; |
9211 | ||
b28ab83c PZ |
9212 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9213 | WARN_ON(!hlist); | |
9214 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9215 | } |
b28ab83c | 9216 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9217 | } |
9218 | ||
2965faa5 | 9219 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9220 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9221 | { |
108b02cf | 9222 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9223 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9224 | struct perf_event *event; | |
0793a61d | 9225 | |
fae3fde6 PZ |
9226 | raw_spin_lock(&ctx->lock); |
9227 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9228 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9229 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9230 | } |
108b02cf PZ |
9231 | |
9232 | static void perf_event_exit_cpu_context(int cpu) | |
9233 | { | |
9234 | struct perf_event_context *ctx; | |
9235 | struct pmu *pmu; | |
9236 | int idx; | |
9237 | ||
9238 | idx = srcu_read_lock(&pmus_srcu); | |
9239 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9240 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9241 | |
9242 | mutex_lock(&ctx->mutex); | |
9243 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9244 | mutex_unlock(&ctx->mutex); | |
9245 | } | |
9246 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9247 | } |
9248 | ||
cdd6c482 | 9249 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9250 | { |
e3703f8c | 9251 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9252 | } |
9253 | #else | |
cdd6c482 | 9254 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9255 | #endif |
9256 | ||
c277443c PZ |
9257 | static int |
9258 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9259 | { | |
9260 | int cpu; | |
9261 | ||
9262 | for_each_online_cpu(cpu) | |
9263 | perf_event_exit_cpu(cpu); | |
9264 | ||
9265 | return NOTIFY_OK; | |
9266 | } | |
9267 | ||
9268 | /* | |
9269 | * Run the perf reboot notifier at the very last possible moment so that | |
9270 | * the generic watchdog code runs as long as possible. | |
9271 | */ | |
9272 | static struct notifier_block perf_reboot_notifier = { | |
9273 | .notifier_call = perf_reboot, | |
9274 | .priority = INT_MIN, | |
9275 | }; | |
9276 | ||
0db0628d | 9277 | static int |
0793a61d TG |
9278 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9279 | { | |
9280 | unsigned int cpu = (long)hcpu; | |
9281 | ||
4536e4d1 | 9282 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9283 | |
9284 | case CPU_UP_PREPARE: | |
cdd6c482 | 9285 | perf_event_init_cpu(cpu); |
0793a61d TG |
9286 | break; |
9287 | ||
9288 | case CPU_DOWN_PREPARE: | |
cdd6c482 | 9289 | perf_event_exit_cpu(cpu); |
0793a61d | 9290 | break; |
0793a61d TG |
9291 | default: |
9292 | break; | |
9293 | } | |
9294 | ||
9295 | return NOTIFY_OK; | |
9296 | } | |
9297 | ||
cdd6c482 | 9298 | void __init perf_event_init(void) |
0793a61d | 9299 | { |
3c502e7a JW |
9300 | int ret; |
9301 | ||
2e80a82a PZ |
9302 | idr_init(&pmu_idr); |
9303 | ||
220b140b | 9304 | perf_event_init_all_cpus(); |
b0a873eb | 9305 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9306 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9307 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9308 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9309 | perf_tp_register(); |
9310 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9311 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9312 | |
9313 | ret = init_hw_breakpoint(); | |
9314 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9315 | |
9316 | /* do not patch jump label more than once per second */ | |
9317 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9318 | |
9319 | /* | |
9320 | * Build time assertion that we keep the data_head at the intended | |
9321 | * location. IOW, validation we got the __reserved[] size right. | |
9322 | */ | |
9323 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9324 | != 1024); | |
0793a61d | 9325 | } |
abe43400 | 9326 | |
fd979c01 CS |
9327 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9328 | char *page) | |
9329 | { | |
9330 | struct perf_pmu_events_attr *pmu_attr = | |
9331 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9332 | ||
9333 | if (pmu_attr->event_str) | |
9334 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9335 | ||
9336 | return 0; | |
9337 | } | |
9338 | ||
abe43400 PZ |
9339 | static int __init perf_event_sysfs_init(void) |
9340 | { | |
9341 | struct pmu *pmu; | |
9342 | int ret; | |
9343 | ||
9344 | mutex_lock(&pmus_lock); | |
9345 | ||
9346 | ret = bus_register(&pmu_bus); | |
9347 | if (ret) | |
9348 | goto unlock; | |
9349 | ||
9350 | list_for_each_entry(pmu, &pmus, entry) { | |
9351 | if (!pmu->name || pmu->type < 0) | |
9352 | continue; | |
9353 | ||
9354 | ret = pmu_dev_alloc(pmu); | |
9355 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9356 | } | |
9357 | pmu_bus_running = 1; | |
9358 | ret = 0; | |
9359 | ||
9360 | unlock: | |
9361 | mutex_unlock(&pmus_lock); | |
9362 | ||
9363 | return ret; | |
9364 | } | |
9365 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9366 | |
9367 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9368 | static struct cgroup_subsys_state * |
9369 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9370 | { |
9371 | struct perf_cgroup *jc; | |
e5d1367f | 9372 | |
1b15d055 | 9373 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9374 | if (!jc) |
9375 | return ERR_PTR(-ENOMEM); | |
9376 | ||
e5d1367f SE |
9377 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9378 | if (!jc->info) { | |
9379 | kfree(jc); | |
9380 | return ERR_PTR(-ENOMEM); | |
9381 | } | |
9382 | ||
e5d1367f SE |
9383 | return &jc->css; |
9384 | } | |
9385 | ||
eb95419b | 9386 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9387 | { |
eb95419b TH |
9388 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9389 | ||
e5d1367f SE |
9390 | free_percpu(jc->info); |
9391 | kfree(jc); | |
9392 | } | |
9393 | ||
9394 | static int __perf_cgroup_move(void *info) | |
9395 | { | |
9396 | struct task_struct *task = info; | |
ddaaf4e2 | 9397 | rcu_read_lock(); |
e5d1367f | 9398 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9399 | rcu_read_unlock(); |
e5d1367f SE |
9400 | return 0; |
9401 | } | |
9402 | ||
1f7dd3e5 | 9403 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9404 | { |
bb9d97b6 | 9405 | struct task_struct *task; |
1f7dd3e5 | 9406 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9407 | |
1f7dd3e5 | 9408 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9409 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9410 | } |
9411 | ||
073219e9 | 9412 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9413 | .css_alloc = perf_cgroup_css_alloc, |
9414 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9415 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9416 | }; |
9417 | #endif /* CONFIG_CGROUP_PERF */ |