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) | |
135 | { | |
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; | |
201 | struct perf_event_context *ctx = event->ctx; | |
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 | } | |
273 | ||
0017960f | 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 |
45a0e07a | 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); |
fe4b04fa | 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) | |
2088 | { | |
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); | |
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; |
2c29ef0f | 2107 | |
63b6da39 | 2108 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2109 | if (ctx->task) { |
63b6da39 | 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 | */ | |
63b6da39 | 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); | |
b58f6b0d PZ |
2125 | } |
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; |
d859e29f | 2217 | |
6e801e01 PZ |
2218 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2219 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2220 | return; |
e5d1367f | 2221 | |
fae3fde6 | 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; |
3b6f9e5c | 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 PZ |
2332 | struct perf_event *event; |
2333 | ||
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); | |
2343 | return; | |
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 | } | |
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 | |
39a43640 PZ |
2735 | if (likely(!ctx->nr_events)) |
2736 | return; | |
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 PM |
3370 | err = -EACCES; |
3371 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
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 | |
683ede43 PZ |
3761 | /* |
3762 | * There are two ways this annotation is useful: | |
3763 | * | |
3764 | * 1) there is a lock recursion from perf_event_exit_task | |
3765 | * see the comment there. | |
3766 | * | |
3767 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3768 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3769 | * holding ctx->mutex, however this is called after |
3770 | * the last filedesc died, so there is no possibility | |
3771 | * to trigger the AB-BA case. | |
3772 | */ | |
a83fe28e PZ |
3773 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3774 | WARN_ON_ONCE(ctx->parent_ctx); | |
60beda84 | 3775 | perf_remove_from_context(event, DETACH_GROUP | DETACH_STATE); |
d415a7f1 | 3776 | perf_event_ctx_unlock(event, ctx); |
683ede43 | 3777 | |
60beda84 PZ |
3778 | /* |
3779 | * At this point we must have event->state == PERF_EVENT_STATE_EXIT, | |
3780 | * either from the above perf_remove_from_context() or through | |
3781 | * perf_event_exit_event(). | |
c6e5b732 PZ |
3782 | * |
3783 | * Therefore, anybody acquiring event->child_mutex after the below | |
3784 | * loop _must_ also see this, most importantly inherit_event() which | |
3785 | * will avoid placing more children on the list. | |
3786 | * | |
3787 | * Thus this guarantees that we will in fact observe and kill _ALL_ | |
3788 | * child events. | |
60beda84 PZ |
3789 | */ |
3790 | WARN_ON_ONCE(event->state != PERF_EVENT_STATE_EXIT); | |
3791 | ||
c6e5b732 PZ |
3792 | again: |
3793 | mutex_lock(&event->child_mutex); | |
3794 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3795 | |
c6e5b732 PZ |
3796 | /* |
3797 | * Cannot change, child events are not migrated, see the | |
3798 | * comment with perf_event_ctx_lock_nested(). | |
3799 | */ | |
3800 | ctx = lockless_dereference(child->ctx); | |
3801 | /* | |
3802 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3803 | * through hoops. We start by grabbing a reference on the ctx. | |
3804 | * | |
3805 | * Since the event cannot get freed while we hold the | |
3806 | * child_mutex, the context must also exist and have a !0 | |
3807 | * reference count. | |
3808 | */ | |
3809 | get_ctx(ctx); | |
3810 | ||
3811 | /* | |
3812 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3813 | * acquire ctx::mutex without fear of it going away. Then we | |
3814 | * can re-acquire child_mutex. | |
3815 | */ | |
3816 | mutex_unlock(&event->child_mutex); | |
3817 | mutex_lock(&ctx->mutex); | |
3818 | mutex_lock(&event->child_mutex); | |
3819 | ||
3820 | /* | |
3821 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3822 | * state, if child is still the first entry, it didn't get freed | |
3823 | * and we can continue doing so. | |
3824 | */ | |
3825 | tmp = list_first_entry_or_null(&event->child_list, | |
3826 | struct perf_event, child_list); | |
3827 | if (tmp == child) { | |
3828 | perf_remove_from_context(child, DETACH_GROUP); | |
3829 | list_del(&child->child_list); | |
3830 | free_event(child); | |
3831 | /* | |
3832 | * This matches the refcount bump in inherit_event(); | |
3833 | * this can't be the last reference. | |
3834 | */ | |
3835 | put_event(event); | |
3836 | } | |
3837 | ||
3838 | mutex_unlock(&event->child_mutex); | |
3839 | mutex_unlock(&ctx->mutex); | |
3840 | put_ctx(ctx); | |
3841 | goto again; | |
3842 | } | |
3843 | mutex_unlock(&event->child_mutex); | |
3844 | ||
3845 | /* Must be the last reference */ | |
683ede43 PZ |
3846 | put_event(event); |
3847 | return 0; | |
3848 | } | |
3849 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3850 | ||
8b10c5e2 PZ |
3851 | /* |
3852 | * Called when the last reference to the file is gone. | |
3853 | */ | |
a6fa941d AV |
3854 | static int perf_release(struct inode *inode, struct file *file) |
3855 | { | |
c6e5b732 | 3856 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3857 | return 0; |
fb0459d7 | 3858 | } |
fb0459d7 | 3859 | |
59ed446f | 3860 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3861 | { |
cdd6c482 | 3862 | struct perf_event *child; |
e53c0994 PZ |
3863 | u64 total = 0; |
3864 | ||
59ed446f PZ |
3865 | *enabled = 0; |
3866 | *running = 0; | |
3867 | ||
6f10581a | 3868 | mutex_lock(&event->child_mutex); |
01add3ea | 3869 | |
7d88962e | 3870 | (void)perf_event_read(event, false); |
01add3ea SB |
3871 | total += perf_event_count(event); |
3872 | ||
59ed446f PZ |
3873 | *enabled += event->total_time_enabled + |
3874 | atomic64_read(&event->child_total_time_enabled); | |
3875 | *running += event->total_time_running + | |
3876 | atomic64_read(&event->child_total_time_running); | |
3877 | ||
3878 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3879 | (void)perf_event_read(child, false); |
01add3ea | 3880 | total += perf_event_count(child); |
59ed446f PZ |
3881 | *enabled += child->total_time_enabled; |
3882 | *running += child->total_time_running; | |
3883 | } | |
6f10581a | 3884 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3885 | |
3886 | return total; | |
3887 | } | |
fb0459d7 | 3888 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3889 | |
7d88962e | 3890 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3891 | u64 read_format, u64 *values) |
3dab77fb | 3892 | { |
fa8c2693 PZ |
3893 | struct perf_event *sub; |
3894 | int n = 1; /* skip @nr */ | |
7d88962e | 3895 | int ret; |
f63a8daa | 3896 | |
7d88962e SB |
3897 | ret = perf_event_read(leader, true); |
3898 | if (ret) | |
3899 | return ret; | |
abf4868b | 3900 | |
fa8c2693 PZ |
3901 | /* |
3902 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3903 | * will be identical to those of the leader, so we only publish one | |
3904 | * set. | |
3905 | */ | |
3906 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3907 | values[n++] += leader->total_time_enabled + | |
3908 | atomic64_read(&leader->child_total_time_enabled); | |
3909 | } | |
3dab77fb | 3910 | |
fa8c2693 PZ |
3911 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3912 | values[n++] += leader->total_time_running + | |
3913 | atomic64_read(&leader->child_total_time_running); | |
3914 | } | |
3915 | ||
3916 | /* | |
3917 | * Write {count,id} tuples for every sibling. | |
3918 | */ | |
3919 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3920 | if (read_format & PERF_FORMAT_ID) |
3921 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3922 | |
fa8c2693 PZ |
3923 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3924 | values[n++] += perf_event_count(sub); | |
3925 | if (read_format & PERF_FORMAT_ID) | |
3926 | values[n++] = primary_event_id(sub); | |
3927 | } | |
7d88962e SB |
3928 | |
3929 | return 0; | |
fa8c2693 | 3930 | } |
3dab77fb | 3931 | |
fa8c2693 PZ |
3932 | static int perf_read_group(struct perf_event *event, |
3933 | u64 read_format, char __user *buf) | |
3934 | { | |
3935 | struct perf_event *leader = event->group_leader, *child; | |
3936 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3937 | int ret; |
fa8c2693 | 3938 | u64 *values; |
3dab77fb | 3939 | |
fa8c2693 | 3940 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3941 | |
fa8c2693 PZ |
3942 | values = kzalloc(event->read_size, GFP_KERNEL); |
3943 | if (!values) | |
3944 | return -ENOMEM; | |
3dab77fb | 3945 | |
fa8c2693 PZ |
3946 | values[0] = 1 + leader->nr_siblings; |
3947 | ||
3948 | /* | |
3949 | * By locking the child_mutex of the leader we effectively | |
3950 | * lock the child list of all siblings.. XXX explain how. | |
3951 | */ | |
3952 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3953 | |
7d88962e SB |
3954 | ret = __perf_read_group_add(leader, read_format, values); |
3955 | if (ret) | |
3956 | goto unlock; | |
3957 | ||
3958 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3959 | ret = __perf_read_group_add(child, read_format, values); | |
3960 | if (ret) | |
3961 | goto unlock; | |
3962 | } | |
abf4868b | 3963 | |
fa8c2693 | 3964 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3965 | |
7d88962e | 3966 | ret = event->read_size; |
fa8c2693 PZ |
3967 | if (copy_to_user(buf, values, event->read_size)) |
3968 | ret = -EFAULT; | |
7d88962e | 3969 | goto out; |
fa8c2693 | 3970 | |
7d88962e SB |
3971 | unlock: |
3972 | mutex_unlock(&leader->child_mutex); | |
3973 | out: | |
fa8c2693 | 3974 | kfree(values); |
abf4868b | 3975 | return ret; |
3dab77fb PZ |
3976 | } |
3977 | ||
b15f495b | 3978 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3979 | u64 read_format, char __user *buf) |
3980 | { | |
59ed446f | 3981 | u64 enabled, running; |
3dab77fb PZ |
3982 | u64 values[4]; |
3983 | int n = 0; | |
3984 | ||
59ed446f PZ |
3985 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3986 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3987 | values[n++] = enabled; | |
3988 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3989 | values[n++] = running; | |
3dab77fb | 3990 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3991 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3992 | |
3993 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3994 | return -EFAULT; | |
3995 | ||
3996 | return n * sizeof(u64); | |
3997 | } | |
3998 | ||
dc633982 JO |
3999 | static bool is_event_hup(struct perf_event *event) |
4000 | { | |
4001 | bool no_children; | |
4002 | ||
4003 | if (event->state != PERF_EVENT_STATE_EXIT) | |
4004 | return false; | |
4005 | ||
4006 | mutex_lock(&event->child_mutex); | |
4007 | no_children = list_empty(&event->child_list); | |
4008 | mutex_unlock(&event->child_mutex); | |
4009 | return no_children; | |
4010 | } | |
4011 | ||
0793a61d | 4012 | /* |
cdd6c482 | 4013 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4014 | */ |
4015 | static ssize_t | |
b15f495b | 4016 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4017 | { |
cdd6c482 | 4018 | u64 read_format = event->attr.read_format; |
3dab77fb | 4019 | int ret; |
0793a61d | 4020 | |
3b6f9e5c | 4021 | /* |
cdd6c482 | 4022 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4023 | * error state (i.e. because it was pinned but it couldn't be |
4024 | * scheduled on to the CPU at some point). | |
4025 | */ | |
cdd6c482 | 4026 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4027 | return 0; |
4028 | ||
c320c7b7 | 4029 | if (count < event->read_size) |
3dab77fb PZ |
4030 | return -ENOSPC; |
4031 | ||
cdd6c482 | 4032 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4033 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4034 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4035 | else |
b15f495b | 4036 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4037 | |
3dab77fb | 4038 | return ret; |
0793a61d TG |
4039 | } |
4040 | ||
0793a61d TG |
4041 | static ssize_t |
4042 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4043 | { | |
cdd6c482 | 4044 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4045 | struct perf_event_context *ctx; |
4046 | int ret; | |
0793a61d | 4047 | |
f63a8daa | 4048 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4049 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4050 | perf_event_ctx_unlock(event, ctx); |
4051 | ||
4052 | return ret; | |
0793a61d TG |
4053 | } |
4054 | ||
4055 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4056 | { | |
cdd6c482 | 4057 | struct perf_event *event = file->private_data; |
76369139 | 4058 | struct ring_buffer *rb; |
61b67684 | 4059 | unsigned int events = POLLHUP; |
c7138f37 | 4060 | |
e708d7ad | 4061 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4062 | |
dc633982 | 4063 | if (is_event_hup(event)) |
179033b3 | 4064 | return events; |
c7138f37 | 4065 | |
10c6db11 | 4066 | /* |
9bb5d40c PZ |
4067 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4068 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4069 | */ |
4070 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4071 | rb = event->rb; |
4072 | if (rb) | |
76369139 | 4073 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4074 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4075 | return events; |
4076 | } | |
4077 | ||
f63a8daa | 4078 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4079 | { |
7d88962e | 4080 | (void)perf_event_read(event, false); |
e7850595 | 4081 | local64_set(&event->count, 0); |
cdd6c482 | 4082 | perf_event_update_userpage(event); |
3df5edad PZ |
4083 | } |
4084 | ||
c93f7669 | 4085 | /* |
cdd6c482 IM |
4086 | * Holding the top-level event's child_mutex means that any |
4087 | * descendant process that has inherited this event will block | |
8ba289b8 | 4088 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4089 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4090 | */ |
cdd6c482 IM |
4091 | static void perf_event_for_each_child(struct perf_event *event, |
4092 | void (*func)(struct perf_event *)) | |
3df5edad | 4093 | { |
cdd6c482 | 4094 | struct perf_event *child; |
3df5edad | 4095 | |
cdd6c482 | 4096 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4097 | |
cdd6c482 IM |
4098 | mutex_lock(&event->child_mutex); |
4099 | func(event); | |
4100 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4101 | func(child); |
cdd6c482 | 4102 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4103 | } |
4104 | ||
cdd6c482 IM |
4105 | static void perf_event_for_each(struct perf_event *event, |
4106 | void (*func)(struct perf_event *)) | |
3df5edad | 4107 | { |
cdd6c482 IM |
4108 | struct perf_event_context *ctx = event->ctx; |
4109 | struct perf_event *sibling; | |
3df5edad | 4110 | |
f63a8daa PZ |
4111 | lockdep_assert_held(&ctx->mutex); |
4112 | ||
cdd6c482 | 4113 | event = event->group_leader; |
75f937f2 | 4114 | |
cdd6c482 | 4115 | perf_event_for_each_child(event, func); |
cdd6c482 | 4116 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4117 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4118 | } |
4119 | ||
fae3fde6 PZ |
4120 | static void __perf_event_period(struct perf_event *event, |
4121 | struct perf_cpu_context *cpuctx, | |
4122 | struct perf_event_context *ctx, | |
4123 | void *info) | |
c7999c6f | 4124 | { |
fae3fde6 | 4125 | u64 value = *((u64 *)info); |
c7999c6f | 4126 | bool active; |
08247e31 | 4127 | |
cdd6c482 | 4128 | if (event->attr.freq) { |
cdd6c482 | 4129 | event->attr.sample_freq = value; |
08247e31 | 4130 | } else { |
cdd6c482 IM |
4131 | event->attr.sample_period = value; |
4132 | event->hw.sample_period = value; | |
08247e31 | 4133 | } |
bad7192b PZ |
4134 | |
4135 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4136 | if (active) { | |
4137 | perf_pmu_disable(ctx->pmu); | |
4138 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4139 | } | |
4140 | ||
4141 | local64_set(&event->hw.period_left, 0); | |
4142 | ||
4143 | if (active) { | |
4144 | event->pmu->start(event, PERF_EF_RELOAD); | |
4145 | perf_pmu_enable(ctx->pmu); | |
4146 | } | |
c7999c6f PZ |
4147 | } |
4148 | ||
4149 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4150 | { | |
c7999c6f PZ |
4151 | u64 value; |
4152 | ||
4153 | if (!is_sampling_event(event)) | |
4154 | return -EINVAL; | |
4155 | ||
4156 | if (copy_from_user(&value, arg, sizeof(value))) | |
4157 | return -EFAULT; | |
4158 | ||
4159 | if (!value) | |
4160 | return -EINVAL; | |
4161 | ||
4162 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4163 | return -EINVAL; | |
4164 | ||
fae3fde6 | 4165 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4166 | |
c7999c6f | 4167 | return 0; |
08247e31 PZ |
4168 | } |
4169 | ||
ac9721f3 PZ |
4170 | static const struct file_operations perf_fops; |
4171 | ||
2903ff01 | 4172 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4173 | { |
2903ff01 AV |
4174 | struct fd f = fdget(fd); |
4175 | if (!f.file) | |
4176 | return -EBADF; | |
ac9721f3 | 4177 | |
2903ff01 AV |
4178 | if (f.file->f_op != &perf_fops) { |
4179 | fdput(f); | |
4180 | return -EBADF; | |
ac9721f3 | 4181 | } |
2903ff01 AV |
4182 | *p = f; |
4183 | return 0; | |
ac9721f3 PZ |
4184 | } |
4185 | ||
4186 | static int perf_event_set_output(struct perf_event *event, | |
4187 | struct perf_event *output_event); | |
6fb2915d | 4188 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4189 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4190 | |
f63a8daa | 4191 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4192 | { |
cdd6c482 | 4193 | void (*func)(struct perf_event *); |
3df5edad | 4194 | u32 flags = arg; |
d859e29f PM |
4195 | |
4196 | switch (cmd) { | |
cdd6c482 | 4197 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4198 | func = _perf_event_enable; |
d859e29f | 4199 | break; |
cdd6c482 | 4200 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4201 | func = _perf_event_disable; |
79f14641 | 4202 | break; |
cdd6c482 | 4203 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4204 | func = _perf_event_reset; |
6de6a7b9 | 4205 | break; |
3df5edad | 4206 | |
cdd6c482 | 4207 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4208 | return _perf_event_refresh(event, arg); |
08247e31 | 4209 | |
cdd6c482 IM |
4210 | case PERF_EVENT_IOC_PERIOD: |
4211 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4212 | |
cf4957f1 JO |
4213 | case PERF_EVENT_IOC_ID: |
4214 | { | |
4215 | u64 id = primary_event_id(event); | |
4216 | ||
4217 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4218 | return -EFAULT; | |
4219 | return 0; | |
4220 | } | |
4221 | ||
cdd6c482 | 4222 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4223 | { |
ac9721f3 | 4224 | int ret; |
ac9721f3 | 4225 | if (arg != -1) { |
2903ff01 AV |
4226 | struct perf_event *output_event; |
4227 | struct fd output; | |
4228 | ret = perf_fget_light(arg, &output); | |
4229 | if (ret) | |
4230 | return ret; | |
4231 | output_event = output.file->private_data; | |
4232 | ret = perf_event_set_output(event, output_event); | |
4233 | fdput(output); | |
4234 | } else { | |
4235 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4236 | } |
ac9721f3 PZ |
4237 | return ret; |
4238 | } | |
a4be7c27 | 4239 | |
6fb2915d LZ |
4240 | case PERF_EVENT_IOC_SET_FILTER: |
4241 | return perf_event_set_filter(event, (void __user *)arg); | |
4242 | ||
2541517c AS |
4243 | case PERF_EVENT_IOC_SET_BPF: |
4244 | return perf_event_set_bpf_prog(event, arg); | |
4245 | ||
d859e29f | 4246 | default: |
3df5edad | 4247 | return -ENOTTY; |
d859e29f | 4248 | } |
3df5edad PZ |
4249 | |
4250 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4251 | perf_event_for_each(event, func); |
3df5edad | 4252 | else |
cdd6c482 | 4253 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4254 | |
4255 | return 0; | |
d859e29f PM |
4256 | } |
4257 | ||
f63a8daa PZ |
4258 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4259 | { | |
4260 | struct perf_event *event = file->private_data; | |
4261 | struct perf_event_context *ctx; | |
4262 | long ret; | |
4263 | ||
4264 | ctx = perf_event_ctx_lock(event); | |
4265 | ret = _perf_ioctl(event, cmd, arg); | |
4266 | perf_event_ctx_unlock(event, ctx); | |
4267 | ||
4268 | return ret; | |
4269 | } | |
4270 | ||
b3f20785 PM |
4271 | #ifdef CONFIG_COMPAT |
4272 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4273 | unsigned long arg) | |
4274 | { | |
4275 | switch (_IOC_NR(cmd)) { | |
4276 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4277 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4278 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4279 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4280 | cmd &= ~IOCSIZE_MASK; | |
4281 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4282 | } | |
4283 | break; | |
4284 | } | |
4285 | return perf_ioctl(file, cmd, arg); | |
4286 | } | |
4287 | #else | |
4288 | # define perf_compat_ioctl NULL | |
4289 | #endif | |
4290 | ||
cdd6c482 | 4291 | int perf_event_task_enable(void) |
771d7cde | 4292 | { |
f63a8daa | 4293 | struct perf_event_context *ctx; |
cdd6c482 | 4294 | struct perf_event *event; |
771d7cde | 4295 | |
cdd6c482 | 4296 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4297 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4298 | ctx = perf_event_ctx_lock(event); | |
4299 | perf_event_for_each_child(event, _perf_event_enable); | |
4300 | perf_event_ctx_unlock(event, ctx); | |
4301 | } | |
cdd6c482 | 4302 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4303 | |
4304 | return 0; | |
4305 | } | |
4306 | ||
cdd6c482 | 4307 | int perf_event_task_disable(void) |
771d7cde | 4308 | { |
f63a8daa | 4309 | struct perf_event_context *ctx; |
cdd6c482 | 4310 | struct perf_event *event; |
771d7cde | 4311 | |
cdd6c482 | 4312 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4313 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4314 | ctx = perf_event_ctx_lock(event); | |
4315 | perf_event_for_each_child(event, _perf_event_disable); | |
4316 | perf_event_ctx_unlock(event, ctx); | |
4317 | } | |
cdd6c482 | 4318 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4319 | |
4320 | return 0; | |
4321 | } | |
4322 | ||
cdd6c482 | 4323 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4324 | { |
a4eaf7f1 PZ |
4325 | if (event->hw.state & PERF_HES_STOPPED) |
4326 | return 0; | |
4327 | ||
cdd6c482 | 4328 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4329 | return 0; |
4330 | ||
35edc2a5 | 4331 | return event->pmu->event_idx(event); |
194002b2 PZ |
4332 | } |
4333 | ||
c4794295 | 4334 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4335 | u64 *now, |
7f310a5d EM |
4336 | u64 *enabled, |
4337 | u64 *running) | |
c4794295 | 4338 | { |
e3f3541c | 4339 | u64 ctx_time; |
c4794295 | 4340 | |
e3f3541c PZ |
4341 | *now = perf_clock(); |
4342 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4343 | *enabled = ctx_time - event->tstamp_enabled; |
4344 | *running = ctx_time - event->tstamp_running; | |
4345 | } | |
4346 | ||
fa731587 PZ |
4347 | static void perf_event_init_userpage(struct perf_event *event) |
4348 | { | |
4349 | struct perf_event_mmap_page *userpg; | |
4350 | struct ring_buffer *rb; | |
4351 | ||
4352 | rcu_read_lock(); | |
4353 | rb = rcu_dereference(event->rb); | |
4354 | if (!rb) | |
4355 | goto unlock; | |
4356 | ||
4357 | userpg = rb->user_page; | |
4358 | ||
4359 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4360 | userpg->cap_bit0_is_deprecated = 1; | |
4361 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4362 | userpg->data_offset = PAGE_SIZE; |
4363 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4364 | |
4365 | unlock: | |
4366 | rcu_read_unlock(); | |
4367 | } | |
4368 | ||
c1317ec2 AL |
4369 | void __weak arch_perf_update_userpage( |
4370 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4371 | { |
4372 | } | |
4373 | ||
38ff667b PZ |
4374 | /* |
4375 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4376 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4377 | * code calls this from NMI context. | |
4378 | */ | |
cdd6c482 | 4379 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4380 | { |
cdd6c482 | 4381 | struct perf_event_mmap_page *userpg; |
76369139 | 4382 | struct ring_buffer *rb; |
e3f3541c | 4383 | u64 enabled, running, now; |
38ff667b PZ |
4384 | |
4385 | rcu_read_lock(); | |
5ec4c599 PZ |
4386 | rb = rcu_dereference(event->rb); |
4387 | if (!rb) | |
4388 | goto unlock; | |
4389 | ||
0d641208 EM |
4390 | /* |
4391 | * compute total_time_enabled, total_time_running | |
4392 | * based on snapshot values taken when the event | |
4393 | * was last scheduled in. | |
4394 | * | |
4395 | * we cannot simply called update_context_time() | |
4396 | * because of locking issue as we can be called in | |
4397 | * NMI context | |
4398 | */ | |
e3f3541c | 4399 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4400 | |
76369139 | 4401 | userpg = rb->user_page; |
7b732a75 PZ |
4402 | /* |
4403 | * Disable preemption so as to not let the corresponding user-space | |
4404 | * spin too long if we get preempted. | |
4405 | */ | |
4406 | preempt_disable(); | |
37d81828 | 4407 | ++userpg->lock; |
92f22a38 | 4408 | barrier(); |
cdd6c482 | 4409 | userpg->index = perf_event_index(event); |
b5e58793 | 4410 | userpg->offset = perf_event_count(event); |
365a4038 | 4411 | if (userpg->index) |
e7850595 | 4412 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4413 | |
0d641208 | 4414 | userpg->time_enabled = enabled + |
cdd6c482 | 4415 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4416 | |
0d641208 | 4417 | userpg->time_running = running + |
cdd6c482 | 4418 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4419 | |
c1317ec2 | 4420 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4421 | |
92f22a38 | 4422 | barrier(); |
37d81828 | 4423 | ++userpg->lock; |
7b732a75 | 4424 | preempt_enable(); |
38ff667b | 4425 | unlock: |
7b732a75 | 4426 | rcu_read_unlock(); |
37d81828 PM |
4427 | } |
4428 | ||
906010b2 PZ |
4429 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4430 | { | |
4431 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4432 | struct ring_buffer *rb; |
906010b2 PZ |
4433 | int ret = VM_FAULT_SIGBUS; |
4434 | ||
4435 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4436 | if (vmf->pgoff == 0) | |
4437 | ret = 0; | |
4438 | return ret; | |
4439 | } | |
4440 | ||
4441 | rcu_read_lock(); | |
76369139 FW |
4442 | rb = rcu_dereference(event->rb); |
4443 | if (!rb) | |
906010b2 PZ |
4444 | goto unlock; |
4445 | ||
4446 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4447 | goto unlock; | |
4448 | ||
76369139 | 4449 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4450 | if (!vmf->page) |
4451 | goto unlock; | |
4452 | ||
4453 | get_page(vmf->page); | |
4454 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4455 | vmf->page->index = vmf->pgoff; | |
4456 | ||
4457 | ret = 0; | |
4458 | unlock: | |
4459 | rcu_read_unlock(); | |
4460 | ||
4461 | return ret; | |
4462 | } | |
4463 | ||
10c6db11 PZ |
4464 | static void ring_buffer_attach(struct perf_event *event, |
4465 | struct ring_buffer *rb) | |
4466 | { | |
b69cf536 | 4467 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4468 | unsigned long flags; |
4469 | ||
b69cf536 PZ |
4470 | if (event->rb) { |
4471 | /* | |
4472 | * Should be impossible, we set this when removing | |
4473 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4474 | */ | |
4475 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4476 | |
b69cf536 | 4477 | old_rb = event->rb; |
b69cf536 PZ |
4478 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4479 | list_del_rcu(&event->rb_entry); | |
4480 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4481 | |
2f993cf0 ON |
4482 | event->rcu_batches = get_state_synchronize_rcu(); |
4483 | event->rcu_pending = 1; | |
b69cf536 | 4484 | } |
10c6db11 | 4485 | |
b69cf536 | 4486 | if (rb) { |
2f993cf0 ON |
4487 | if (event->rcu_pending) { |
4488 | cond_synchronize_rcu(event->rcu_batches); | |
4489 | event->rcu_pending = 0; | |
4490 | } | |
4491 | ||
b69cf536 PZ |
4492 | spin_lock_irqsave(&rb->event_lock, flags); |
4493 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4494 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4495 | } | |
4496 | ||
4497 | rcu_assign_pointer(event->rb, rb); | |
4498 | ||
4499 | if (old_rb) { | |
4500 | ring_buffer_put(old_rb); | |
4501 | /* | |
4502 | * Since we detached before setting the new rb, so that we | |
4503 | * could attach the new rb, we could have missed a wakeup. | |
4504 | * Provide it now. | |
4505 | */ | |
4506 | wake_up_all(&event->waitq); | |
4507 | } | |
10c6db11 PZ |
4508 | } |
4509 | ||
4510 | static void ring_buffer_wakeup(struct perf_event *event) | |
4511 | { | |
4512 | struct ring_buffer *rb; | |
4513 | ||
4514 | rcu_read_lock(); | |
4515 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4516 | if (rb) { |
4517 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4518 | wake_up_all(&event->waitq); | |
4519 | } | |
10c6db11 PZ |
4520 | rcu_read_unlock(); |
4521 | } | |
4522 | ||
fdc26706 | 4523 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4524 | { |
76369139 | 4525 | struct ring_buffer *rb; |
7b732a75 | 4526 | |
ac9721f3 | 4527 | rcu_read_lock(); |
76369139 FW |
4528 | rb = rcu_dereference(event->rb); |
4529 | if (rb) { | |
4530 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4531 | rb = NULL; | |
ac9721f3 PZ |
4532 | } |
4533 | rcu_read_unlock(); | |
4534 | ||
76369139 | 4535 | return rb; |
ac9721f3 PZ |
4536 | } |
4537 | ||
fdc26706 | 4538 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4539 | { |
76369139 | 4540 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4541 | return; |
7b732a75 | 4542 | |
9bb5d40c | 4543 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4544 | |
76369139 | 4545 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4546 | } |
4547 | ||
4548 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4549 | { | |
cdd6c482 | 4550 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4551 | |
cdd6c482 | 4552 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4553 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4554 | |
45bfb2e5 PZ |
4555 | if (vma->vm_pgoff) |
4556 | atomic_inc(&event->rb->aux_mmap_count); | |
4557 | ||
1e0fb9ec AL |
4558 | if (event->pmu->event_mapped) |
4559 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4560 | } |
4561 | ||
9bb5d40c PZ |
4562 | /* |
4563 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4564 | * event, or through other events by use of perf_event_set_output(). | |
4565 | * | |
4566 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4567 | * the buffer here, where we still have a VM context. This means we need | |
4568 | * to detach all events redirecting to us. | |
4569 | */ | |
7b732a75 PZ |
4570 | static void perf_mmap_close(struct vm_area_struct *vma) |
4571 | { | |
cdd6c482 | 4572 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4573 | |
b69cf536 | 4574 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4575 | struct user_struct *mmap_user = rb->mmap_user; |
4576 | int mmap_locked = rb->mmap_locked; | |
4577 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4578 | |
1e0fb9ec AL |
4579 | if (event->pmu->event_unmapped) |
4580 | event->pmu->event_unmapped(event); | |
4581 | ||
45bfb2e5 PZ |
4582 | /* |
4583 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4584 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4585 | * serialize with perf_mmap here. | |
4586 | */ | |
4587 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4588 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4589 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4590 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4591 | ||
4592 | rb_free_aux(rb); | |
4593 | mutex_unlock(&event->mmap_mutex); | |
4594 | } | |
4595 | ||
9bb5d40c PZ |
4596 | atomic_dec(&rb->mmap_count); |
4597 | ||
4598 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4599 | goto out_put; |
9bb5d40c | 4600 | |
b69cf536 | 4601 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4602 | mutex_unlock(&event->mmap_mutex); |
4603 | ||
4604 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4605 | if (atomic_read(&rb->mmap_count)) |
4606 | goto out_put; | |
ac9721f3 | 4607 | |
9bb5d40c PZ |
4608 | /* |
4609 | * No other mmap()s, detach from all other events that might redirect | |
4610 | * into the now unreachable buffer. Somewhat complicated by the | |
4611 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4612 | */ | |
4613 | again: | |
4614 | rcu_read_lock(); | |
4615 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4616 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4617 | /* | |
4618 | * This event is en-route to free_event() which will | |
4619 | * detach it and remove it from the list. | |
4620 | */ | |
4621 | continue; | |
4622 | } | |
4623 | rcu_read_unlock(); | |
789f90fc | 4624 | |
9bb5d40c PZ |
4625 | mutex_lock(&event->mmap_mutex); |
4626 | /* | |
4627 | * Check we didn't race with perf_event_set_output() which can | |
4628 | * swizzle the rb from under us while we were waiting to | |
4629 | * acquire mmap_mutex. | |
4630 | * | |
4631 | * If we find a different rb; ignore this event, a next | |
4632 | * iteration will no longer find it on the list. We have to | |
4633 | * still restart the iteration to make sure we're not now | |
4634 | * iterating the wrong list. | |
4635 | */ | |
b69cf536 PZ |
4636 | if (event->rb == rb) |
4637 | ring_buffer_attach(event, NULL); | |
4638 | ||
cdd6c482 | 4639 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4640 | put_event(event); |
ac9721f3 | 4641 | |
9bb5d40c PZ |
4642 | /* |
4643 | * Restart the iteration; either we're on the wrong list or | |
4644 | * destroyed its integrity by doing a deletion. | |
4645 | */ | |
4646 | goto again; | |
7b732a75 | 4647 | } |
9bb5d40c PZ |
4648 | rcu_read_unlock(); |
4649 | ||
4650 | /* | |
4651 | * It could be there's still a few 0-ref events on the list; they'll | |
4652 | * get cleaned up by free_event() -- they'll also still have their | |
4653 | * ref on the rb and will free it whenever they are done with it. | |
4654 | * | |
4655 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4656 | * undo the VM accounting. | |
4657 | */ | |
4658 | ||
4659 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4660 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4661 | free_uid(mmap_user); | |
4662 | ||
b69cf536 | 4663 | out_put: |
9bb5d40c | 4664 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4665 | } |
4666 | ||
f0f37e2f | 4667 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4668 | .open = perf_mmap_open, |
45bfb2e5 | 4669 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4670 | .fault = perf_mmap_fault, |
4671 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4672 | }; |
4673 | ||
4674 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4675 | { | |
cdd6c482 | 4676 | struct perf_event *event = file->private_data; |
22a4f650 | 4677 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4678 | struct user_struct *user = current_user(); |
22a4f650 | 4679 | unsigned long locked, lock_limit; |
45bfb2e5 | 4680 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4681 | unsigned long vma_size; |
4682 | unsigned long nr_pages; | |
45bfb2e5 | 4683 | long user_extra = 0, extra = 0; |
d57e34fd | 4684 | int ret = 0, flags = 0; |
37d81828 | 4685 | |
c7920614 PZ |
4686 | /* |
4687 | * Don't allow mmap() of inherited per-task counters. This would | |
4688 | * create a performance issue due to all children writing to the | |
76369139 | 4689 | * same rb. |
c7920614 PZ |
4690 | */ |
4691 | if (event->cpu == -1 && event->attr.inherit) | |
4692 | return -EINVAL; | |
4693 | ||
43a21ea8 | 4694 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4695 | return -EINVAL; |
7b732a75 PZ |
4696 | |
4697 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4698 | |
4699 | if (vma->vm_pgoff == 0) { | |
4700 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4701 | } else { | |
4702 | /* | |
4703 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4704 | * mapped, all subsequent mappings should have the same size | |
4705 | * and offset. Must be above the normal perf buffer. | |
4706 | */ | |
4707 | u64 aux_offset, aux_size; | |
4708 | ||
4709 | if (!event->rb) | |
4710 | return -EINVAL; | |
4711 | ||
4712 | nr_pages = vma_size / PAGE_SIZE; | |
4713 | ||
4714 | mutex_lock(&event->mmap_mutex); | |
4715 | ret = -EINVAL; | |
4716 | ||
4717 | rb = event->rb; | |
4718 | if (!rb) | |
4719 | goto aux_unlock; | |
4720 | ||
4721 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4722 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4723 | ||
4724 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4725 | goto aux_unlock; | |
4726 | ||
4727 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4728 | goto aux_unlock; | |
4729 | ||
4730 | /* already mapped with a different offset */ | |
4731 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4732 | goto aux_unlock; | |
4733 | ||
4734 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4735 | goto aux_unlock; | |
4736 | ||
4737 | /* already mapped with a different size */ | |
4738 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4739 | goto aux_unlock; | |
4740 | ||
4741 | if (!is_power_of_2(nr_pages)) | |
4742 | goto aux_unlock; | |
4743 | ||
4744 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4745 | goto aux_unlock; | |
4746 | ||
4747 | if (rb_has_aux(rb)) { | |
4748 | atomic_inc(&rb->aux_mmap_count); | |
4749 | ret = 0; | |
4750 | goto unlock; | |
4751 | } | |
4752 | ||
4753 | atomic_set(&rb->aux_mmap_count, 1); | |
4754 | user_extra = nr_pages; | |
4755 | ||
4756 | goto accounting; | |
4757 | } | |
7b732a75 | 4758 | |
7730d865 | 4759 | /* |
76369139 | 4760 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4761 | * can do bitmasks instead of modulo. |
4762 | */ | |
2ed11312 | 4763 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4764 | return -EINVAL; |
4765 | ||
7b732a75 | 4766 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4767 | return -EINVAL; |
4768 | ||
cdd6c482 | 4769 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4770 | again: |
cdd6c482 | 4771 | mutex_lock(&event->mmap_mutex); |
76369139 | 4772 | if (event->rb) { |
9bb5d40c | 4773 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4774 | ret = -EINVAL; |
9bb5d40c PZ |
4775 | goto unlock; |
4776 | } | |
4777 | ||
4778 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4779 | /* | |
4780 | * Raced against perf_mmap_close() through | |
4781 | * perf_event_set_output(). Try again, hope for better | |
4782 | * luck. | |
4783 | */ | |
4784 | mutex_unlock(&event->mmap_mutex); | |
4785 | goto again; | |
4786 | } | |
4787 | ||
ebb3c4c4 PZ |
4788 | goto unlock; |
4789 | } | |
4790 | ||
789f90fc | 4791 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4792 | |
4793 | accounting: | |
cdd6c482 | 4794 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4795 | |
4796 | /* | |
4797 | * Increase the limit linearly with more CPUs: | |
4798 | */ | |
4799 | user_lock_limit *= num_online_cpus(); | |
4800 | ||
789f90fc | 4801 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4802 | |
789f90fc PZ |
4803 | if (user_locked > user_lock_limit) |
4804 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4805 | |
78d7d407 | 4806 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4807 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4808 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4809 | |
459ec28a IM |
4810 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4811 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4812 | ret = -EPERM; |
4813 | goto unlock; | |
4814 | } | |
7b732a75 | 4815 | |
45bfb2e5 | 4816 | WARN_ON(!rb && event->rb); |
906010b2 | 4817 | |
d57e34fd | 4818 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4819 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4820 | |
76369139 | 4821 | if (!rb) { |
45bfb2e5 PZ |
4822 | rb = rb_alloc(nr_pages, |
4823 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4824 | event->cpu, flags); | |
26cb63ad | 4825 | |
45bfb2e5 PZ |
4826 | if (!rb) { |
4827 | ret = -ENOMEM; | |
4828 | goto unlock; | |
4829 | } | |
43a21ea8 | 4830 | |
45bfb2e5 PZ |
4831 | atomic_set(&rb->mmap_count, 1); |
4832 | rb->mmap_user = get_current_user(); | |
4833 | rb->mmap_locked = extra; | |
26cb63ad | 4834 | |
45bfb2e5 | 4835 | ring_buffer_attach(event, rb); |
ac9721f3 | 4836 | |
45bfb2e5 PZ |
4837 | perf_event_init_userpage(event); |
4838 | perf_event_update_userpage(event); | |
4839 | } else { | |
1a594131 AS |
4840 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4841 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4842 | if (!ret) |
4843 | rb->aux_mmap_locked = extra; | |
4844 | } | |
9a0f05cb | 4845 | |
ebb3c4c4 | 4846 | unlock: |
45bfb2e5 PZ |
4847 | if (!ret) { |
4848 | atomic_long_add(user_extra, &user->locked_vm); | |
4849 | vma->vm_mm->pinned_vm += extra; | |
4850 | ||
ac9721f3 | 4851 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4852 | } else if (rb) { |
4853 | atomic_dec(&rb->mmap_count); | |
4854 | } | |
4855 | aux_unlock: | |
cdd6c482 | 4856 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4857 | |
9bb5d40c PZ |
4858 | /* |
4859 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4860 | * vma. | |
4861 | */ | |
26cb63ad | 4862 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4863 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4864 | |
1e0fb9ec AL |
4865 | if (event->pmu->event_mapped) |
4866 | event->pmu->event_mapped(event); | |
4867 | ||
7b732a75 | 4868 | return ret; |
37d81828 PM |
4869 | } |
4870 | ||
3c446b3d PZ |
4871 | static int perf_fasync(int fd, struct file *filp, int on) |
4872 | { | |
496ad9aa | 4873 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4874 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4875 | int retval; |
4876 | ||
4877 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4878 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4879 | mutex_unlock(&inode->i_mutex); |
4880 | ||
4881 | if (retval < 0) | |
4882 | return retval; | |
4883 | ||
4884 | return 0; | |
4885 | } | |
4886 | ||
0793a61d | 4887 | static const struct file_operations perf_fops = { |
3326c1ce | 4888 | .llseek = no_llseek, |
0793a61d TG |
4889 | .release = perf_release, |
4890 | .read = perf_read, | |
4891 | .poll = perf_poll, | |
d859e29f | 4892 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4893 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4894 | .mmap = perf_mmap, |
3c446b3d | 4895 | .fasync = perf_fasync, |
0793a61d TG |
4896 | }; |
4897 | ||
925d519a | 4898 | /* |
cdd6c482 | 4899 | * Perf event wakeup |
925d519a PZ |
4900 | * |
4901 | * If there's data, ensure we set the poll() state and publish everything | |
4902 | * to user-space before waking everybody up. | |
4903 | */ | |
4904 | ||
fed66e2c PZ |
4905 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4906 | { | |
4907 | /* only the parent has fasync state */ | |
4908 | if (event->parent) | |
4909 | event = event->parent; | |
4910 | return &event->fasync; | |
4911 | } | |
4912 | ||
cdd6c482 | 4913 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4914 | { |
10c6db11 | 4915 | ring_buffer_wakeup(event); |
4c9e2542 | 4916 | |
cdd6c482 | 4917 | if (event->pending_kill) { |
fed66e2c | 4918 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4919 | event->pending_kill = 0; |
4c9e2542 | 4920 | } |
925d519a PZ |
4921 | } |
4922 | ||
e360adbe | 4923 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4924 | { |
cdd6c482 IM |
4925 | struct perf_event *event = container_of(entry, |
4926 | struct perf_event, pending); | |
d525211f PZ |
4927 | int rctx; |
4928 | ||
4929 | rctx = perf_swevent_get_recursion_context(); | |
4930 | /* | |
4931 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4932 | * and we won't recurse 'further'. | |
4933 | */ | |
79f14641 | 4934 | |
cdd6c482 IM |
4935 | if (event->pending_disable) { |
4936 | event->pending_disable = 0; | |
fae3fde6 | 4937 | perf_event_disable_local(event); |
79f14641 PZ |
4938 | } |
4939 | ||
cdd6c482 IM |
4940 | if (event->pending_wakeup) { |
4941 | event->pending_wakeup = 0; | |
4942 | perf_event_wakeup(event); | |
79f14641 | 4943 | } |
d525211f PZ |
4944 | |
4945 | if (rctx >= 0) | |
4946 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4947 | } |
4948 | ||
39447b38 ZY |
4949 | /* |
4950 | * We assume there is only KVM supporting the callbacks. | |
4951 | * Later on, we might change it to a list if there is | |
4952 | * another virtualization implementation supporting the callbacks. | |
4953 | */ | |
4954 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4955 | ||
4956 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4957 | { | |
4958 | perf_guest_cbs = cbs; | |
4959 | return 0; | |
4960 | } | |
4961 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4962 | ||
4963 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4964 | { | |
4965 | perf_guest_cbs = NULL; | |
4966 | return 0; | |
4967 | } | |
4968 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4969 | ||
4018994f JO |
4970 | static void |
4971 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4972 | struct pt_regs *regs, u64 mask) | |
4973 | { | |
4974 | int bit; | |
4975 | ||
4976 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4977 | sizeof(mask) * BITS_PER_BYTE) { | |
4978 | u64 val; | |
4979 | ||
4980 | val = perf_reg_value(regs, bit); | |
4981 | perf_output_put(handle, val); | |
4982 | } | |
4983 | } | |
4984 | ||
60e2364e | 4985 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4986 | struct pt_regs *regs, |
4987 | struct pt_regs *regs_user_copy) | |
4018994f | 4988 | { |
88a7c26a AL |
4989 | if (user_mode(regs)) { |
4990 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4991 | regs_user->regs = regs; |
88a7c26a AL |
4992 | } else if (current->mm) { |
4993 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4994 | } else { |
4995 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4996 | regs_user->regs = NULL; | |
4018994f JO |
4997 | } |
4998 | } | |
4999 | ||
60e2364e SE |
5000 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5001 | struct pt_regs *regs) | |
5002 | { | |
5003 | regs_intr->regs = regs; | |
5004 | regs_intr->abi = perf_reg_abi(current); | |
5005 | } | |
5006 | ||
5007 | ||
c5ebcedb JO |
5008 | /* |
5009 | * Get remaining task size from user stack pointer. | |
5010 | * | |
5011 | * It'd be better to take stack vma map and limit this more | |
5012 | * precisly, but there's no way to get it safely under interrupt, | |
5013 | * so using TASK_SIZE as limit. | |
5014 | */ | |
5015 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5016 | { | |
5017 | unsigned long addr = perf_user_stack_pointer(regs); | |
5018 | ||
5019 | if (!addr || addr >= TASK_SIZE) | |
5020 | return 0; | |
5021 | ||
5022 | return TASK_SIZE - addr; | |
5023 | } | |
5024 | ||
5025 | static u16 | |
5026 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5027 | struct pt_regs *regs) | |
5028 | { | |
5029 | u64 task_size; | |
5030 | ||
5031 | /* No regs, no stack pointer, no dump. */ | |
5032 | if (!regs) | |
5033 | return 0; | |
5034 | ||
5035 | /* | |
5036 | * Check if we fit in with the requested stack size into the: | |
5037 | * - TASK_SIZE | |
5038 | * If we don't, we limit the size to the TASK_SIZE. | |
5039 | * | |
5040 | * - remaining sample size | |
5041 | * If we don't, we customize the stack size to | |
5042 | * fit in to the remaining sample size. | |
5043 | */ | |
5044 | ||
5045 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5046 | stack_size = min(stack_size, (u16) task_size); | |
5047 | ||
5048 | /* Current header size plus static size and dynamic size. */ | |
5049 | header_size += 2 * sizeof(u64); | |
5050 | ||
5051 | /* Do we fit in with the current stack dump size? */ | |
5052 | if ((u16) (header_size + stack_size) < header_size) { | |
5053 | /* | |
5054 | * If we overflow the maximum size for the sample, | |
5055 | * we customize the stack dump size to fit in. | |
5056 | */ | |
5057 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5058 | stack_size = round_up(stack_size, sizeof(u64)); | |
5059 | } | |
5060 | ||
5061 | return stack_size; | |
5062 | } | |
5063 | ||
5064 | static void | |
5065 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5066 | struct pt_regs *regs) | |
5067 | { | |
5068 | /* Case of a kernel thread, nothing to dump */ | |
5069 | if (!regs) { | |
5070 | u64 size = 0; | |
5071 | perf_output_put(handle, size); | |
5072 | } else { | |
5073 | unsigned long sp; | |
5074 | unsigned int rem; | |
5075 | u64 dyn_size; | |
5076 | ||
5077 | /* | |
5078 | * We dump: | |
5079 | * static size | |
5080 | * - the size requested by user or the best one we can fit | |
5081 | * in to the sample max size | |
5082 | * data | |
5083 | * - user stack dump data | |
5084 | * dynamic size | |
5085 | * - the actual dumped size | |
5086 | */ | |
5087 | ||
5088 | /* Static size. */ | |
5089 | perf_output_put(handle, dump_size); | |
5090 | ||
5091 | /* Data. */ | |
5092 | sp = perf_user_stack_pointer(regs); | |
5093 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5094 | dyn_size = dump_size - rem; | |
5095 | ||
5096 | perf_output_skip(handle, rem); | |
5097 | ||
5098 | /* Dynamic size. */ | |
5099 | perf_output_put(handle, dyn_size); | |
5100 | } | |
5101 | } | |
5102 | ||
c980d109 ACM |
5103 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5104 | struct perf_sample_data *data, | |
5105 | struct perf_event *event) | |
6844c09d ACM |
5106 | { |
5107 | u64 sample_type = event->attr.sample_type; | |
5108 | ||
5109 | data->type = sample_type; | |
5110 | header->size += event->id_header_size; | |
5111 | ||
5112 | if (sample_type & PERF_SAMPLE_TID) { | |
5113 | /* namespace issues */ | |
5114 | data->tid_entry.pid = perf_event_pid(event, current); | |
5115 | data->tid_entry.tid = perf_event_tid(event, current); | |
5116 | } | |
5117 | ||
5118 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5119 | data->time = perf_event_clock(event); |
6844c09d | 5120 | |
ff3d527c | 5121 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5122 | data->id = primary_event_id(event); |
5123 | ||
5124 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5125 | data->stream_id = event->id; | |
5126 | ||
5127 | if (sample_type & PERF_SAMPLE_CPU) { | |
5128 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5129 | data->cpu_entry.reserved = 0; | |
5130 | } | |
5131 | } | |
5132 | ||
76369139 FW |
5133 | void perf_event_header__init_id(struct perf_event_header *header, |
5134 | struct perf_sample_data *data, | |
5135 | struct perf_event *event) | |
c980d109 ACM |
5136 | { |
5137 | if (event->attr.sample_id_all) | |
5138 | __perf_event_header__init_id(header, data, event); | |
5139 | } | |
5140 | ||
5141 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5142 | struct perf_sample_data *data) | |
5143 | { | |
5144 | u64 sample_type = data->type; | |
5145 | ||
5146 | if (sample_type & PERF_SAMPLE_TID) | |
5147 | perf_output_put(handle, data->tid_entry); | |
5148 | ||
5149 | if (sample_type & PERF_SAMPLE_TIME) | |
5150 | perf_output_put(handle, data->time); | |
5151 | ||
5152 | if (sample_type & PERF_SAMPLE_ID) | |
5153 | perf_output_put(handle, data->id); | |
5154 | ||
5155 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5156 | perf_output_put(handle, data->stream_id); | |
5157 | ||
5158 | if (sample_type & PERF_SAMPLE_CPU) | |
5159 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5160 | |
5161 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5162 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5163 | } |
5164 | ||
76369139 FW |
5165 | void perf_event__output_id_sample(struct perf_event *event, |
5166 | struct perf_output_handle *handle, | |
5167 | struct perf_sample_data *sample) | |
c980d109 ACM |
5168 | { |
5169 | if (event->attr.sample_id_all) | |
5170 | __perf_event__output_id_sample(handle, sample); | |
5171 | } | |
5172 | ||
3dab77fb | 5173 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5174 | struct perf_event *event, |
5175 | u64 enabled, u64 running) | |
3dab77fb | 5176 | { |
cdd6c482 | 5177 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5178 | u64 values[4]; |
5179 | int n = 0; | |
5180 | ||
b5e58793 | 5181 | values[n++] = perf_event_count(event); |
3dab77fb | 5182 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5183 | values[n++] = enabled + |
cdd6c482 | 5184 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5185 | } |
5186 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5187 | values[n++] = running + |
cdd6c482 | 5188 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5189 | } |
5190 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5191 | values[n++] = primary_event_id(event); |
3dab77fb | 5192 | |
76369139 | 5193 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5194 | } |
5195 | ||
5196 | /* | |
cdd6c482 | 5197 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5198 | */ |
5199 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5200 | struct perf_event *event, |
5201 | u64 enabled, u64 running) | |
3dab77fb | 5202 | { |
cdd6c482 IM |
5203 | struct perf_event *leader = event->group_leader, *sub; |
5204 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5205 | u64 values[5]; |
5206 | int n = 0; | |
5207 | ||
5208 | values[n++] = 1 + leader->nr_siblings; | |
5209 | ||
5210 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5211 | values[n++] = enabled; |
3dab77fb PZ |
5212 | |
5213 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5214 | values[n++] = running; |
3dab77fb | 5215 | |
cdd6c482 | 5216 | if (leader != event) |
3dab77fb PZ |
5217 | leader->pmu->read(leader); |
5218 | ||
b5e58793 | 5219 | values[n++] = perf_event_count(leader); |
3dab77fb | 5220 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5221 | values[n++] = primary_event_id(leader); |
3dab77fb | 5222 | |
76369139 | 5223 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5224 | |
65abc865 | 5225 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5226 | n = 0; |
5227 | ||
6f5ab001 JO |
5228 | if ((sub != event) && |
5229 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5230 | sub->pmu->read(sub); |
5231 | ||
b5e58793 | 5232 | values[n++] = perf_event_count(sub); |
3dab77fb | 5233 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5234 | values[n++] = primary_event_id(sub); |
3dab77fb | 5235 | |
76369139 | 5236 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5237 | } |
5238 | } | |
5239 | ||
eed01528 SE |
5240 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5241 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5242 | ||
3dab77fb | 5243 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5244 | struct perf_event *event) |
3dab77fb | 5245 | { |
e3f3541c | 5246 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5247 | u64 read_format = event->attr.read_format; |
5248 | ||
5249 | /* | |
5250 | * compute total_time_enabled, total_time_running | |
5251 | * based on snapshot values taken when the event | |
5252 | * was last scheduled in. | |
5253 | * | |
5254 | * we cannot simply called update_context_time() | |
5255 | * because of locking issue as we are called in | |
5256 | * NMI context | |
5257 | */ | |
c4794295 | 5258 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5259 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5260 | |
cdd6c482 | 5261 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5262 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5263 | else |
eed01528 | 5264 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5265 | } |
5266 | ||
5622f295 MM |
5267 | void perf_output_sample(struct perf_output_handle *handle, |
5268 | struct perf_event_header *header, | |
5269 | struct perf_sample_data *data, | |
cdd6c482 | 5270 | struct perf_event *event) |
5622f295 MM |
5271 | { |
5272 | u64 sample_type = data->type; | |
5273 | ||
5274 | perf_output_put(handle, *header); | |
5275 | ||
ff3d527c AH |
5276 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5277 | perf_output_put(handle, data->id); | |
5278 | ||
5622f295 MM |
5279 | if (sample_type & PERF_SAMPLE_IP) |
5280 | perf_output_put(handle, data->ip); | |
5281 | ||
5282 | if (sample_type & PERF_SAMPLE_TID) | |
5283 | perf_output_put(handle, data->tid_entry); | |
5284 | ||
5285 | if (sample_type & PERF_SAMPLE_TIME) | |
5286 | perf_output_put(handle, data->time); | |
5287 | ||
5288 | if (sample_type & PERF_SAMPLE_ADDR) | |
5289 | perf_output_put(handle, data->addr); | |
5290 | ||
5291 | if (sample_type & PERF_SAMPLE_ID) | |
5292 | perf_output_put(handle, data->id); | |
5293 | ||
5294 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5295 | perf_output_put(handle, data->stream_id); | |
5296 | ||
5297 | if (sample_type & PERF_SAMPLE_CPU) | |
5298 | perf_output_put(handle, data->cpu_entry); | |
5299 | ||
5300 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5301 | perf_output_put(handle, data->period); | |
5302 | ||
5303 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5304 | perf_output_read(handle, event); |
5622f295 MM |
5305 | |
5306 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5307 | if (data->callchain) { | |
5308 | int size = 1; | |
5309 | ||
5310 | if (data->callchain) | |
5311 | size += data->callchain->nr; | |
5312 | ||
5313 | size *= sizeof(u64); | |
5314 | ||
76369139 | 5315 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5316 | } else { |
5317 | u64 nr = 0; | |
5318 | perf_output_put(handle, nr); | |
5319 | } | |
5320 | } | |
5321 | ||
5322 | if (sample_type & PERF_SAMPLE_RAW) { | |
5323 | if (data->raw) { | |
fa128e6a AS |
5324 | u32 raw_size = data->raw->size; |
5325 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5326 | sizeof(u64)) - sizeof(u32); | |
5327 | u64 zero = 0; | |
5328 | ||
5329 | perf_output_put(handle, real_size); | |
5330 | __output_copy(handle, data->raw->data, raw_size); | |
5331 | if (real_size - raw_size) | |
5332 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5333 | } else { |
5334 | struct { | |
5335 | u32 size; | |
5336 | u32 data; | |
5337 | } raw = { | |
5338 | .size = sizeof(u32), | |
5339 | .data = 0, | |
5340 | }; | |
5341 | perf_output_put(handle, raw); | |
5342 | } | |
5343 | } | |
a7ac67ea | 5344 | |
bce38cd5 SE |
5345 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5346 | if (data->br_stack) { | |
5347 | size_t size; | |
5348 | ||
5349 | size = data->br_stack->nr | |
5350 | * sizeof(struct perf_branch_entry); | |
5351 | ||
5352 | perf_output_put(handle, data->br_stack->nr); | |
5353 | perf_output_copy(handle, data->br_stack->entries, size); | |
5354 | } else { | |
5355 | /* | |
5356 | * we always store at least the value of nr | |
5357 | */ | |
5358 | u64 nr = 0; | |
5359 | perf_output_put(handle, nr); | |
5360 | } | |
5361 | } | |
4018994f JO |
5362 | |
5363 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5364 | u64 abi = data->regs_user.abi; | |
5365 | ||
5366 | /* | |
5367 | * If there are no regs to dump, notice it through | |
5368 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5369 | */ | |
5370 | perf_output_put(handle, abi); | |
5371 | ||
5372 | if (abi) { | |
5373 | u64 mask = event->attr.sample_regs_user; | |
5374 | perf_output_sample_regs(handle, | |
5375 | data->regs_user.regs, | |
5376 | mask); | |
5377 | } | |
5378 | } | |
c5ebcedb | 5379 | |
a5cdd40c | 5380 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5381 | perf_output_sample_ustack(handle, |
5382 | data->stack_user_size, | |
5383 | data->regs_user.regs); | |
a5cdd40c | 5384 | } |
c3feedf2 AK |
5385 | |
5386 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5387 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5388 | |
5389 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5390 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5391 | |
fdfbbd07 AK |
5392 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5393 | perf_output_put(handle, data->txn); | |
5394 | ||
60e2364e SE |
5395 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5396 | u64 abi = data->regs_intr.abi; | |
5397 | /* | |
5398 | * If there are no regs to dump, notice it through | |
5399 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5400 | */ | |
5401 | perf_output_put(handle, abi); | |
5402 | ||
5403 | if (abi) { | |
5404 | u64 mask = event->attr.sample_regs_intr; | |
5405 | ||
5406 | perf_output_sample_regs(handle, | |
5407 | data->regs_intr.regs, | |
5408 | mask); | |
5409 | } | |
5410 | } | |
5411 | ||
a5cdd40c PZ |
5412 | if (!event->attr.watermark) { |
5413 | int wakeup_events = event->attr.wakeup_events; | |
5414 | ||
5415 | if (wakeup_events) { | |
5416 | struct ring_buffer *rb = handle->rb; | |
5417 | int events = local_inc_return(&rb->events); | |
5418 | ||
5419 | if (events >= wakeup_events) { | |
5420 | local_sub(wakeup_events, &rb->events); | |
5421 | local_inc(&rb->wakeup); | |
5422 | } | |
5423 | } | |
5424 | } | |
5622f295 MM |
5425 | } |
5426 | ||
5427 | void perf_prepare_sample(struct perf_event_header *header, | |
5428 | struct perf_sample_data *data, | |
cdd6c482 | 5429 | struct perf_event *event, |
5622f295 | 5430 | struct pt_regs *regs) |
7b732a75 | 5431 | { |
cdd6c482 | 5432 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5433 | |
cdd6c482 | 5434 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5435 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5436 | |
5437 | header->misc = 0; | |
5438 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5439 | |
c980d109 | 5440 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5441 | |
c320c7b7 | 5442 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5443 | data->ip = perf_instruction_pointer(regs); |
5444 | ||
b23f3325 | 5445 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5446 | int size = 1; |
394ee076 | 5447 | |
e6dab5ff | 5448 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5449 | |
5450 | if (data->callchain) | |
5451 | size += data->callchain->nr; | |
5452 | ||
5453 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5454 | } |
5455 | ||
3a43ce68 | 5456 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5457 | int size = sizeof(u32); |
5458 | ||
5459 | if (data->raw) | |
5460 | size += data->raw->size; | |
5461 | else | |
5462 | size += sizeof(u32); | |
5463 | ||
fa128e6a | 5464 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5465 | } |
bce38cd5 SE |
5466 | |
5467 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5468 | int size = sizeof(u64); /* nr */ | |
5469 | if (data->br_stack) { | |
5470 | size += data->br_stack->nr | |
5471 | * sizeof(struct perf_branch_entry); | |
5472 | } | |
5473 | header->size += size; | |
5474 | } | |
4018994f | 5475 | |
2565711f | 5476 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5477 | perf_sample_regs_user(&data->regs_user, regs, |
5478 | &data->regs_user_copy); | |
2565711f | 5479 | |
4018994f JO |
5480 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5481 | /* regs dump ABI info */ | |
5482 | int size = sizeof(u64); | |
5483 | ||
4018994f JO |
5484 | if (data->regs_user.regs) { |
5485 | u64 mask = event->attr.sample_regs_user; | |
5486 | size += hweight64(mask) * sizeof(u64); | |
5487 | } | |
5488 | ||
5489 | header->size += size; | |
5490 | } | |
c5ebcedb JO |
5491 | |
5492 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5493 | /* | |
5494 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5495 | * processed as the last one or have additional check added | |
5496 | * in case new sample type is added, because we could eat | |
5497 | * up the rest of the sample size. | |
5498 | */ | |
c5ebcedb JO |
5499 | u16 stack_size = event->attr.sample_stack_user; |
5500 | u16 size = sizeof(u64); | |
5501 | ||
c5ebcedb | 5502 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5503 | data->regs_user.regs); |
c5ebcedb JO |
5504 | |
5505 | /* | |
5506 | * If there is something to dump, add space for the dump | |
5507 | * itself and for the field that tells the dynamic size, | |
5508 | * which is how many have been actually dumped. | |
5509 | */ | |
5510 | if (stack_size) | |
5511 | size += sizeof(u64) + stack_size; | |
5512 | ||
5513 | data->stack_user_size = stack_size; | |
5514 | header->size += size; | |
5515 | } | |
60e2364e SE |
5516 | |
5517 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5518 | /* regs dump ABI info */ | |
5519 | int size = sizeof(u64); | |
5520 | ||
5521 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5522 | ||
5523 | if (data->regs_intr.regs) { | |
5524 | u64 mask = event->attr.sample_regs_intr; | |
5525 | ||
5526 | size += hweight64(mask) * sizeof(u64); | |
5527 | } | |
5528 | ||
5529 | header->size += size; | |
5530 | } | |
5622f295 | 5531 | } |
7f453c24 | 5532 | |
21509084 YZ |
5533 | void perf_event_output(struct perf_event *event, |
5534 | struct perf_sample_data *data, | |
5535 | struct pt_regs *regs) | |
5622f295 MM |
5536 | { |
5537 | struct perf_output_handle handle; | |
5538 | struct perf_event_header header; | |
689802b2 | 5539 | |
927c7a9e FW |
5540 | /* protect the callchain buffers */ |
5541 | rcu_read_lock(); | |
5542 | ||
cdd6c482 | 5543 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5544 | |
a7ac67ea | 5545 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5546 | goto exit; |
0322cd6e | 5547 | |
cdd6c482 | 5548 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5549 | |
8a057d84 | 5550 | perf_output_end(&handle); |
927c7a9e FW |
5551 | |
5552 | exit: | |
5553 | rcu_read_unlock(); | |
0322cd6e PZ |
5554 | } |
5555 | ||
38b200d6 | 5556 | /* |
cdd6c482 | 5557 | * read event_id |
38b200d6 PZ |
5558 | */ |
5559 | ||
5560 | struct perf_read_event { | |
5561 | struct perf_event_header header; | |
5562 | ||
5563 | u32 pid; | |
5564 | u32 tid; | |
38b200d6 PZ |
5565 | }; |
5566 | ||
5567 | static void | |
cdd6c482 | 5568 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5569 | struct task_struct *task) |
5570 | { | |
5571 | struct perf_output_handle handle; | |
c980d109 | 5572 | struct perf_sample_data sample; |
dfc65094 | 5573 | struct perf_read_event read_event = { |
38b200d6 | 5574 | .header = { |
cdd6c482 | 5575 | .type = PERF_RECORD_READ, |
38b200d6 | 5576 | .misc = 0, |
c320c7b7 | 5577 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5578 | }, |
cdd6c482 IM |
5579 | .pid = perf_event_pid(event, task), |
5580 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5581 | }; |
3dab77fb | 5582 | int ret; |
38b200d6 | 5583 | |
c980d109 | 5584 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5585 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5586 | if (ret) |
5587 | return; | |
5588 | ||
dfc65094 | 5589 | perf_output_put(&handle, read_event); |
cdd6c482 | 5590 | perf_output_read(&handle, event); |
c980d109 | 5591 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5592 | |
38b200d6 PZ |
5593 | perf_output_end(&handle); |
5594 | } | |
5595 | ||
52d857a8 JO |
5596 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5597 | ||
5598 | static void | |
5599 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5600 | perf_event_aux_output_cb output, |
5601 | void *data) | |
5602 | { | |
5603 | struct perf_event *event; | |
5604 | ||
5605 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5606 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5607 | continue; | |
5608 | if (!event_filter_match(event)) | |
5609 | continue; | |
67516844 | 5610 | output(event, data); |
52d857a8 JO |
5611 | } |
5612 | } | |
5613 | ||
4e93ad60 JO |
5614 | static void |
5615 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5616 | struct perf_event_context *task_ctx) | |
5617 | { | |
5618 | rcu_read_lock(); | |
5619 | preempt_disable(); | |
5620 | perf_event_aux_ctx(task_ctx, output, data); | |
5621 | preempt_enable(); | |
5622 | rcu_read_unlock(); | |
5623 | } | |
5624 | ||
52d857a8 | 5625 | static void |
67516844 | 5626 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5627 | struct perf_event_context *task_ctx) |
5628 | { | |
5629 | struct perf_cpu_context *cpuctx; | |
5630 | struct perf_event_context *ctx; | |
5631 | struct pmu *pmu; | |
5632 | int ctxn; | |
5633 | ||
4e93ad60 JO |
5634 | /* |
5635 | * If we have task_ctx != NULL we only notify | |
5636 | * the task context itself. The task_ctx is set | |
5637 | * only for EXIT events before releasing task | |
5638 | * context. | |
5639 | */ | |
5640 | if (task_ctx) { | |
5641 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5642 | return; | |
5643 | } | |
5644 | ||
52d857a8 JO |
5645 | rcu_read_lock(); |
5646 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5647 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5648 | if (cpuctx->unique_pmu != pmu) | |
5649 | goto next; | |
67516844 | 5650 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5651 | ctxn = pmu->task_ctx_nr; |
5652 | if (ctxn < 0) | |
5653 | goto next; | |
5654 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5655 | if (ctx) | |
67516844 | 5656 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5657 | next: |
5658 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5659 | } | |
52d857a8 JO |
5660 | rcu_read_unlock(); |
5661 | } | |
5662 | ||
60313ebe | 5663 | /* |
9f498cc5 PZ |
5664 | * task tracking -- fork/exit |
5665 | * | |
13d7a241 | 5666 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5667 | */ |
5668 | ||
9f498cc5 | 5669 | struct perf_task_event { |
3a80b4a3 | 5670 | struct task_struct *task; |
cdd6c482 | 5671 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5672 | |
5673 | struct { | |
5674 | struct perf_event_header header; | |
5675 | ||
5676 | u32 pid; | |
5677 | u32 ppid; | |
9f498cc5 PZ |
5678 | u32 tid; |
5679 | u32 ptid; | |
393b2ad8 | 5680 | u64 time; |
cdd6c482 | 5681 | } event_id; |
60313ebe PZ |
5682 | }; |
5683 | ||
67516844 JO |
5684 | static int perf_event_task_match(struct perf_event *event) |
5685 | { | |
13d7a241 SE |
5686 | return event->attr.comm || event->attr.mmap || |
5687 | event->attr.mmap2 || event->attr.mmap_data || | |
5688 | event->attr.task; | |
67516844 JO |
5689 | } |
5690 | ||
cdd6c482 | 5691 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5692 | void *data) |
60313ebe | 5693 | { |
52d857a8 | 5694 | struct perf_task_event *task_event = data; |
60313ebe | 5695 | struct perf_output_handle handle; |
c980d109 | 5696 | struct perf_sample_data sample; |
9f498cc5 | 5697 | struct task_struct *task = task_event->task; |
c980d109 | 5698 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5699 | |
67516844 JO |
5700 | if (!perf_event_task_match(event)) |
5701 | return; | |
5702 | ||
c980d109 | 5703 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5704 | |
c980d109 | 5705 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5706 | task_event->event_id.header.size); |
ef60777c | 5707 | if (ret) |
c980d109 | 5708 | goto out; |
60313ebe | 5709 | |
cdd6c482 IM |
5710 | task_event->event_id.pid = perf_event_pid(event, task); |
5711 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5712 | |
cdd6c482 IM |
5713 | task_event->event_id.tid = perf_event_tid(event, task); |
5714 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5715 | |
34f43927 PZ |
5716 | task_event->event_id.time = perf_event_clock(event); |
5717 | ||
cdd6c482 | 5718 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5719 | |
c980d109 ACM |
5720 | perf_event__output_id_sample(event, &handle, &sample); |
5721 | ||
60313ebe | 5722 | perf_output_end(&handle); |
c980d109 ACM |
5723 | out: |
5724 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5725 | } |
5726 | ||
cdd6c482 IM |
5727 | static void perf_event_task(struct task_struct *task, |
5728 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5729 | int new) |
60313ebe | 5730 | { |
9f498cc5 | 5731 | struct perf_task_event task_event; |
60313ebe | 5732 | |
cdd6c482 IM |
5733 | if (!atomic_read(&nr_comm_events) && |
5734 | !atomic_read(&nr_mmap_events) && | |
5735 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5736 | return; |
5737 | ||
9f498cc5 | 5738 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5739 | .task = task, |
5740 | .task_ctx = task_ctx, | |
cdd6c482 | 5741 | .event_id = { |
60313ebe | 5742 | .header = { |
cdd6c482 | 5743 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5744 | .misc = 0, |
cdd6c482 | 5745 | .size = sizeof(task_event.event_id), |
60313ebe | 5746 | }, |
573402db PZ |
5747 | /* .pid */ |
5748 | /* .ppid */ | |
9f498cc5 PZ |
5749 | /* .tid */ |
5750 | /* .ptid */ | |
34f43927 | 5751 | /* .time */ |
60313ebe PZ |
5752 | }, |
5753 | }; | |
5754 | ||
67516844 | 5755 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5756 | &task_event, |
5757 | task_ctx); | |
9f498cc5 PZ |
5758 | } |
5759 | ||
cdd6c482 | 5760 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5761 | { |
cdd6c482 | 5762 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5763 | } |
5764 | ||
8d1b2d93 PZ |
5765 | /* |
5766 | * comm tracking | |
5767 | */ | |
5768 | ||
5769 | struct perf_comm_event { | |
22a4f650 IM |
5770 | struct task_struct *task; |
5771 | char *comm; | |
8d1b2d93 PZ |
5772 | int comm_size; |
5773 | ||
5774 | struct { | |
5775 | struct perf_event_header header; | |
5776 | ||
5777 | u32 pid; | |
5778 | u32 tid; | |
cdd6c482 | 5779 | } event_id; |
8d1b2d93 PZ |
5780 | }; |
5781 | ||
67516844 JO |
5782 | static int perf_event_comm_match(struct perf_event *event) |
5783 | { | |
5784 | return event->attr.comm; | |
5785 | } | |
5786 | ||
cdd6c482 | 5787 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5788 | void *data) |
8d1b2d93 | 5789 | { |
52d857a8 | 5790 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5791 | struct perf_output_handle handle; |
c980d109 | 5792 | struct perf_sample_data sample; |
cdd6c482 | 5793 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5794 | int ret; |
5795 | ||
67516844 JO |
5796 | if (!perf_event_comm_match(event)) |
5797 | return; | |
5798 | ||
c980d109 ACM |
5799 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5800 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5801 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5802 | |
5803 | if (ret) | |
c980d109 | 5804 | goto out; |
8d1b2d93 | 5805 | |
cdd6c482 IM |
5806 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5807 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5808 | |
cdd6c482 | 5809 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5810 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5811 | comm_event->comm_size); |
c980d109 ACM |
5812 | |
5813 | perf_event__output_id_sample(event, &handle, &sample); | |
5814 | ||
8d1b2d93 | 5815 | perf_output_end(&handle); |
c980d109 ACM |
5816 | out: |
5817 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5818 | } |
5819 | ||
cdd6c482 | 5820 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5821 | { |
413ee3b4 | 5822 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5823 | unsigned int size; |
8d1b2d93 | 5824 | |
413ee3b4 | 5825 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5826 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5827 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5828 | |
5829 | comm_event->comm = comm; | |
5830 | comm_event->comm_size = size; | |
5831 | ||
cdd6c482 | 5832 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5833 | |
67516844 | 5834 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5835 | comm_event, |
5836 | NULL); | |
8d1b2d93 PZ |
5837 | } |
5838 | ||
82b89778 | 5839 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5840 | { |
9ee318a7 PZ |
5841 | struct perf_comm_event comm_event; |
5842 | ||
cdd6c482 | 5843 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5844 | return; |
a63eaf34 | 5845 | |
9ee318a7 | 5846 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5847 | .task = task, |
573402db PZ |
5848 | /* .comm */ |
5849 | /* .comm_size */ | |
cdd6c482 | 5850 | .event_id = { |
573402db | 5851 | .header = { |
cdd6c482 | 5852 | .type = PERF_RECORD_COMM, |
82b89778 | 5853 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5854 | /* .size */ |
5855 | }, | |
5856 | /* .pid */ | |
5857 | /* .tid */ | |
8d1b2d93 PZ |
5858 | }, |
5859 | }; | |
5860 | ||
cdd6c482 | 5861 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5862 | } |
5863 | ||
0a4a9391 PZ |
5864 | /* |
5865 | * mmap tracking | |
5866 | */ | |
5867 | ||
5868 | struct perf_mmap_event { | |
089dd79d PZ |
5869 | struct vm_area_struct *vma; |
5870 | ||
5871 | const char *file_name; | |
5872 | int file_size; | |
13d7a241 SE |
5873 | int maj, min; |
5874 | u64 ino; | |
5875 | u64 ino_generation; | |
f972eb63 | 5876 | u32 prot, flags; |
0a4a9391 PZ |
5877 | |
5878 | struct { | |
5879 | struct perf_event_header header; | |
5880 | ||
5881 | u32 pid; | |
5882 | u32 tid; | |
5883 | u64 start; | |
5884 | u64 len; | |
5885 | u64 pgoff; | |
cdd6c482 | 5886 | } event_id; |
0a4a9391 PZ |
5887 | }; |
5888 | ||
67516844 JO |
5889 | static int perf_event_mmap_match(struct perf_event *event, |
5890 | void *data) | |
5891 | { | |
5892 | struct perf_mmap_event *mmap_event = data; | |
5893 | struct vm_area_struct *vma = mmap_event->vma; | |
5894 | int executable = vma->vm_flags & VM_EXEC; | |
5895 | ||
5896 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5897 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5898 | } |
5899 | ||
cdd6c482 | 5900 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5901 | void *data) |
0a4a9391 | 5902 | { |
52d857a8 | 5903 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5904 | struct perf_output_handle handle; |
c980d109 | 5905 | struct perf_sample_data sample; |
cdd6c482 | 5906 | int size = mmap_event->event_id.header.size; |
c980d109 | 5907 | int ret; |
0a4a9391 | 5908 | |
67516844 JO |
5909 | if (!perf_event_mmap_match(event, data)) |
5910 | return; | |
5911 | ||
13d7a241 SE |
5912 | if (event->attr.mmap2) { |
5913 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5914 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5915 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5916 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5917 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5918 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5919 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5920 | } |
5921 | ||
c980d109 ACM |
5922 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5923 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5924 | mmap_event->event_id.header.size); |
0a4a9391 | 5925 | if (ret) |
c980d109 | 5926 | goto out; |
0a4a9391 | 5927 | |
cdd6c482 IM |
5928 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5929 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5930 | |
cdd6c482 | 5931 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5932 | |
5933 | if (event->attr.mmap2) { | |
5934 | perf_output_put(&handle, mmap_event->maj); | |
5935 | perf_output_put(&handle, mmap_event->min); | |
5936 | perf_output_put(&handle, mmap_event->ino); | |
5937 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5938 | perf_output_put(&handle, mmap_event->prot); |
5939 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5940 | } |
5941 | ||
76369139 | 5942 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5943 | mmap_event->file_size); |
c980d109 ACM |
5944 | |
5945 | perf_event__output_id_sample(event, &handle, &sample); | |
5946 | ||
78d613eb | 5947 | perf_output_end(&handle); |
c980d109 ACM |
5948 | out: |
5949 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5950 | } |
5951 | ||
cdd6c482 | 5952 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5953 | { |
089dd79d PZ |
5954 | struct vm_area_struct *vma = mmap_event->vma; |
5955 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5956 | int maj = 0, min = 0; |
5957 | u64 ino = 0, gen = 0; | |
f972eb63 | 5958 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5959 | unsigned int size; |
5960 | char tmp[16]; | |
5961 | char *buf = NULL; | |
2c42cfbf | 5962 | char *name; |
413ee3b4 | 5963 | |
0a4a9391 | 5964 | if (file) { |
13d7a241 SE |
5965 | struct inode *inode; |
5966 | dev_t dev; | |
3ea2f2b9 | 5967 | |
2c42cfbf | 5968 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5969 | if (!buf) { |
c7e548b4 ON |
5970 | name = "//enomem"; |
5971 | goto cpy_name; | |
0a4a9391 | 5972 | } |
413ee3b4 | 5973 | /* |
3ea2f2b9 | 5974 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5975 | * need to add enough zero bytes after the string to handle |
5976 | * the 64bit alignment we do later. | |
5977 | */ | |
9bf39ab2 | 5978 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5979 | if (IS_ERR(name)) { |
c7e548b4 ON |
5980 | name = "//toolong"; |
5981 | goto cpy_name; | |
0a4a9391 | 5982 | } |
13d7a241 SE |
5983 | inode = file_inode(vma->vm_file); |
5984 | dev = inode->i_sb->s_dev; | |
5985 | ino = inode->i_ino; | |
5986 | gen = inode->i_generation; | |
5987 | maj = MAJOR(dev); | |
5988 | min = MINOR(dev); | |
f972eb63 PZ |
5989 | |
5990 | if (vma->vm_flags & VM_READ) | |
5991 | prot |= PROT_READ; | |
5992 | if (vma->vm_flags & VM_WRITE) | |
5993 | prot |= PROT_WRITE; | |
5994 | if (vma->vm_flags & VM_EXEC) | |
5995 | prot |= PROT_EXEC; | |
5996 | ||
5997 | if (vma->vm_flags & VM_MAYSHARE) | |
5998 | flags = MAP_SHARED; | |
5999 | else | |
6000 | flags = MAP_PRIVATE; | |
6001 | ||
6002 | if (vma->vm_flags & VM_DENYWRITE) | |
6003 | flags |= MAP_DENYWRITE; | |
6004 | if (vma->vm_flags & VM_MAYEXEC) | |
6005 | flags |= MAP_EXECUTABLE; | |
6006 | if (vma->vm_flags & VM_LOCKED) | |
6007 | flags |= MAP_LOCKED; | |
6008 | if (vma->vm_flags & VM_HUGETLB) | |
6009 | flags |= MAP_HUGETLB; | |
6010 | ||
c7e548b4 | 6011 | goto got_name; |
0a4a9391 | 6012 | } else { |
fbe26abe JO |
6013 | if (vma->vm_ops && vma->vm_ops->name) { |
6014 | name = (char *) vma->vm_ops->name(vma); | |
6015 | if (name) | |
6016 | goto cpy_name; | |
6017 | } | |
6018 | ||
2c42cfbf | 6019 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6020 | if (name) |
6021 | goto cpy_name; | |
089dd79d | 6022 | |
32c5fb7e | 6023 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6024 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6025 | name = "[heap]"; |
6026 | goto cpy_name; | |
32c5fb7e ON |
6027 | } |
6028 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6029 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6030 | name = "[stack]"; |
6031 | goto cpy_name; | |
089dd79d PZ |
6032 | } |
6033 | ||
c7e548b4 ON |
6034 | name = "//anon"; |
6035 | goto cpy_name; | |
0a4a9391 PZ |
6036 | } |
6037 | ||
c7e548b4 ON |
6038 | cpy_name: |
6039 | strlcpy(tmp, name, sizeof(tmp)); | |
6040 | name = tmp; | |
0a4a9391 | 6041 | got_name: |
2c42cfbf PZ |
6042 | /* |
6043 | * Since our buffer works in 8 byte units we need to align our string | |
6044 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6045 | * zero'd out to avoid leaking random bits to userspace. | |
6046 | */ | |
6047 | size = strlen(name)+1; | |
6048 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6049 | name[size++] = '\0'; | |
0a4a9391 PZ |
6050 | |
6051 | mmap_event->file_name = name; | |
6052 | mmap_event->file_size = size; | |
13d7a241 SE |
6053 | mmap_event->maj = maj; |
6054 | mmap_event->min = min; | |
6055 | mmap_event->ino = ino; | |
6056 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6057 | mmap_event->prot = prot; |
6058 | mmap_event->flags = flags; | |
0a4a9391 | 6059 | |
2fe85427 SE |
6060 | if (!(vma->vm_flags & VM_EXEC)) |
6061 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6062 | ||
cdd6c482 | 6063 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6064 | |
67516844 | 6065 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6066 | mmap_event, |
6067 | NULL); | |
665c2142 | 6068 | |
0a4a9391 PZ |
6069 | kfree(buf); |
6070 | } | |
6071 | ||
3af9e859 | 6072 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6073 | { |
9ee318a7 PZ |
6074 | struct perf_mmap_event mmap_event; |
6075 | ||
cdd6c482 | 6076 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6077 | return; |
6078 | ||
6079 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6080 | .vma = vma, |
573402db PZ |
6081 | /* .file_name */ |
6082 | /* .file_size */ | |
cdd6c482 | 6083 | .event_id = { |
573402db | 6084 | .header = { |
cdd6c482 | 6085 | .type = PERF_RECORD_MMAP, |
39447b38 | 6086 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6087 | /* .size */ |
6088 | }, | |
6089 | /* .pid */ | |
6090 | /* .tid */ | |
089dd79d PZ |
6091 | .start = vma->vm_start, |
6092 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6093 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6094 | }, |
13d7a241 SE |
6095 | /* .maj (attr_mmap2 only) */ |
6096 | /* .min (attr_mmap2 only) */ | |
6097 | /* .ino (attr_mmap2 only) */ | |
6098 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6099 | /* .prot (attr_mmap2 only) */ |
6100 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6101 | }; |
6102 | ||
cdd6c482 | 6103 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6104 | } |
6105 | ||
68db7e98 AS |
6106 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6107 | unsigned long size, u64 flags) | |
6108 | { | |
6109 | struct perf_output_handle handle; | |
6110 | struct perf_sample_data sample; | |
6111 | struct perf_aux_event { | |
6112 | struct perf_event_header header; | |
6113 | u64 offset; | |
6114 | u64 size; | |
6115 | u64 flags; | |
6116 | } rec = { | |
6117 | .header = { | |
6118 | .type = PERF_RECORD_AUX, | |
6119 | .misc = 0, | |
6120 | .size = sizeof(rec), | |
6121 | }, | |
6122 | .offset = head, | |
6123 | .size = size, | |
6124 | .flags = flags, | |
6125 | }; | |
6126 | int ret; | |
6127 | ||
6128 | perf_event_header__init_id(&rec.header, &sample, event); | |
6129 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6130 | ||
6131 | if (ret) | |
6132 | return; | |
6133 | ||
6134 | perf_output_put(&handle, rec); | |
6135 | perf_event__output_id_sample(event, &handle, &sample); | |
6136 | ||
6137 | perf_output_end(&handle); | |
6138 | } | |
6139 | ||
f38b0dbb KL |
6140 | /* |
6141 | * Lost/dropped samples logging | |
6142 | */ | |
6143 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6144 | { | |
6145 | struct perf_output_handle handle; | |
6146 | struct perf_sample_data sample; | |
6147 | int ret; | |
6148 | ||
6149 | struct { | |
6150 | struct perf_event_header header; | |
6151 | u64 lost; | |
6152 | } lost_samples_event = { | |
6153 | .header = { | |
6154 | .type = PERF_RECORD_LOST_SAMPLES, | |
6155 | .misc = 0, | |
6156 | .size = sizeof(lost_samples_event), | |
6157 | }, | |
6158 | .lost = lost, | |
6159 | }; | |
6160 | ||
6161 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6162 | ||
6163 | ret = perf_output_begin(&handle, event, | |
6164 | lost_samples_event.header.size); | |
6165 | if (ret) | |
6166 | return; | |
6167 | ||
6168 | perf_output_put(&handle, lost_samples_event); | |
6169 | perf_event__output_id_sample(event, &handle, &sample); | |
6170 | perf_output_end(&handle); | |
6171 | } | |
6172 | ||
45ac1403 AH |
6173 | /* |
6174 | * context_switch tracking | |
6175 | */ | |
6176 | ||
6177 | struct perf_switch_event { | |
6178 | struct task_struct *task; | |
6179 | struct task_struct *next_prev; | |
6180 | ||
6181 | struct { | |
6182 | struct perf_event_header header; | |
6183 | u32 next_prev_pid; | |
6184 | u32 next_prev_tid; | |
6185 | } event_id; | |
6186 | }; | |
6187 | ||
6188 | static int perf_event_switch_match(struct perf_event *event) | |
6189 | { | |
6190 | return event->attr.context_switch; | |
6191 | } | |
6192 | ||
6193 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6194 | { | |
6195 | struct perf_switch_event *se = data; | |
6196 | struct perf_output_handle handle; | |
6197 | struct perf_sample_data sample; | |
6198 | int ret; | |
6199 | ||
6200 | if (!perf_event_switch_match(event)) | |
6201 | return; | |
6202 | ||
6203 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6204 | if (event->ctx->task) { | |
6205 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6206 | se->event_id.header.size = sizeof(se->event_id.header); | |
6207 | } else { | |
6208 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6209 | se->event_id.header.size = sizeof(se->event_id); | |
6210 | se->event_id.next_prev_pid = | |
6211 | perf_event_pid(event, se->next_prev); | |
6212 | se->event_id.next_prev_tid = | |
6213 | perf_event_tid(event, se->next_prev); | |
6214 | } | |
6215 | ||
6216 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6217 | ||
6218 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6219 | if (ret) | |
6220 | return; | |
6221 | ||
6222 | if (event->ctx->task) | |
6223 | perf_output_put(&handle, se->event_id.header); | |
6224 | else | |
6225 | perf_output_put(&handle, se->event_id); | |
6226 | ||
6227 | perf_event__output_id_sample(event, &handle, &sample); | |
6228 | ||
6229 | perf_output_end(&handle); | |
6230 | } | |
6231 | ||
6232 | static void perf_event_switch(struct task_struct *task, | |
6233 | struct task_struct *next_prev, bool sched_in) | |
6234 | { | |
6235 | struct perf_switch_event switch_event; | |
6236 | ||
6237 | /* N.B. caller checks nr_switch_events != 0 */ | |
6238 | ||
6239 | switch_event = (struct perf_switch_event){ | |
6240 | .task = task, | |
6241 | .next_prev = next_prev, | |
6242 | .event_id = { | |
6243 | .header = { | |
6244 | /* .type */ | |
6245 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6246 | /* .size */ | |
6247 | }, | |
6248 | /* .next_prev_pid */ | |
6249 | /* .next_prev_tid */ | |
6250 | }, | |
6251 | }; | |
6252 | ||
6253 | perf_event_aux(perf_event_switch_output, | |
6254 | &switch_event, | |
6255 | NULL); | |
6256 | } | |
6257 | ||
a78ac325 PZ |
6258 | /* |
6259 | * IRQ throttle logging | |
6260 | */ | |
6261 | ||
cdd6c482 | 6262 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6263 | { |
6264 | struct perf_output_handle handle; | |
c980d109 | 6265 | struct perf_sample_data sample; |
a78ac325 PZ |
6266 | int ret; |
6267 | ||
6268 | struct { | |
6269 | struct perf_event_header header; | |
6270 | u64 time; | |
cca3f454 | 6271 | u64 id; |
7f453c24 | 6272 | u64 stream_id; |
a78ac325 PZ |
6273 | } throttle_event = { |
6274 | .header = { | |
cdd6c482 | 6275 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6276 | .misc = 0, |
6277 | .size = sizeof(throttle_event), | |
6278 | }, | |
34f43927 | 6279 | .time = perf_event_clock(event), |
cdd6c482 IM |
6280 | .id = primary_event_id(event), |
6281 | .stream_id = event->id, | |
a78ac325 PZ |
6282 | }; |
6283 | ||
966ee4d6 | 6284 | if (enable) |
cdd6c482 | 6285 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6286 | |
c980d109 ACM |
6287 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6288 | ||
6289 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6290 | throttle_event.header.size); |
a78ac325 PZ |
6291 | if (ret) |
6292 | return; | |
6293 | ||
6294 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6295 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6296 | perf_output_end(&handle); |
6297 | } | |
6298 | ||
ec0d7729 AS |
6299 | static void perf_log_itrace_start(struct perf_event *event) |
6300 | { | |
6301 | struct perf_output_handle handle; | |
6302 | struct perf_sample_data sample; | |
6303 | struct perf_aux_event { | |
6304 | struct perf_event_header header; | |
6305 | u32 pid; | |
6306 | u32 tid; | |
6307 | } rec; | |
6308 | int ret; | |
6309 | ||
6310 | if (event->parent) | |
6311 | event = event->parent; | |
6312 | ||
6313 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6314 | event->hw.itrace_started) | |
6315 | return; | |
6316 | ||
ec0d7729 AS |
6317 | rec.header.type = PERF_RECORD_ITRACE_START; |
6318 | rec.header.misc = 0; | |
6319 | rec.header.size = sizeof(rec); | |
6320 | rec.pid = perf_event_pid(event, current); | |
6321 | rec.tid = perf_event_tid(event, current); | |
6322 | ||
6323 | perf_event_header__init_id(&rec.header, &sample, event); | |
6324 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6325 | ||
6326 | if (ret) | |
6327 | return; | |
6328 | ||
6329 | perf_output_put(&handle, rec); | |
6330 | perf_event__output_id_sample(event, &handle, &sample); | |
6331 | ||
6332 | perf_output_end(&handle); | |
6333 | } | |
6334 | ||
f6c7d5fe | 6335 | /* |
cdd6c482 | 6336 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6337 | */ |
6338 | ||
a8b0ca17 | 6339 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6340 | int throttle, struct perf_sample_data *data, |
6341 | struct pt_regs *regs) | |
f6c7d5fe | 6342 | { |
cdd6c482 IM |
6343 | int events = atomic_read(&event->event_limit); |
6344 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6345 | u64 seq; |
79f14641 PZ |
6346 | int ret = 0; |
6347 | ||
96398826 PZ |
6348 | /* |
6349 | * Non-sampling counters might still use the PMI to fold short | |
6350 | * hardware counters, ignore those. | |
6351 | */ | |
6352 | if (unlikely(!is_sampling_event(event))) | |
6353 | return 0; | |
6354 | ||
e050e3f0 SE |
6355 | seq = __this_cpu_read(perf_throttled_seq); |
6356 | if (seq != hwc->interrupts_seq) { | |
6357 | hwc->interrupts_seq = seq; | |
6358 | hwc->interrupts = 1; | |
6359 | } else { | |
6360 | hwc->interrupts++; | |
6361 | if (unlikely(throttle | |
6362 | && hwc->interrupts >= max_samples_per_tick)) { | |
6363 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6364 | hwc->interrupts = MAX_INTERRUPTS; |
6365 | perf_log_throttle(event, 0); | |
d84153d6 | 6366 | tick_nohz_full_kick(); |
a78ac325 PZ |
6367 | ret = 1; |
6368 | } | |
e050e3f0 | 6369 | } |
60db5e09 | 6370 | |
cdd6c482 | 6371 | if (event->attr.freq) { |
def0a9b2 | 6372 | u64 now = perf_clock(); |
abd50713 | 6373 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6374 | |
abd50713 | 6375 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6376 | |
abd50713 | 6377 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6378 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6379 | } |
6380 | ||
2023b359 PZ |
6381 | /* |
6382 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6383 | * events |
2023b359 PZ |
6384 | */ |
6385 | ||
cdd6c482 IM |
6386 | event->pending_kill = POLL_IN; |
6387 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6388 | ret = 1; |
cdd6c482 | 6389 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6390 | event->pending_disable = 1; |
6391 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6392 | } |
6393 | ||
453f19ee | 6394 | if (event->overflow_handler) |
a8b0ca17 | 6395 | event->overflow_handler(event, data, regs); |
453f19ee | 6396 | else |
a8b0ca17 | 6397 | perf_event_output(event, data, regs); |
453f19ee | 6398 | |
fed66e2c | 6399 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6400 | event->pending_wakeup = 1; |
6401 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6402 | } |
6403 | ||
79f14641 | 6404 | return ret; |
f6c7d5fe PZ |
6405 | } |
6406 | ||
a8b0ca17 | 6407 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6408 | struct perf_sample_data *data, |
6409 | struct pt_regs *regs) | |
850bc73f | 6410 | { |
a8b0ca17 | 6411 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6412 | } |
6413 | ||
15dbf27c | 6414 | /* |
cdd6c482 | 6415 | * Generic software event infrastructure |
15dbf27c PZ |
6416 | */ |
6417 | ||
b28ab83c PZ |
6418 | struct swevent_htable { |
6419 | struct swevent_hlist *swevent_hlist; | |
6420 | struct mutex hlist_mutex; | |
6421 | int hlist_refcount; | |
6422 | ||
6423 | /* Recursion avoidance in each contexts */ | |
6424 | int recursion[PERF_NR_CONTEXTS]; | |
6425 | }; | |
6426 | ||
6427 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6428 | ||
7b4b6658 | 6429 | /* |
cdd6c482 IM |
6430 | * We directly increment event->count and keep a second value in |
6431 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6432 | * is kept in the range [-sample_period, 0] so that we can use the |
6433 | * sign as trigger. | |
6434 | */ | |
6435 | ||
ab573844 | 6436 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6437 | { |
cdd6c482 | 6438 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6439 | u64 period = hwc->last_period; |
6440 | u64 nr, offset; | |
6441 | s64 old, val; | |
6442 | ||
6443 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6444 | |
6445 | again: | |
e7850595 | 6446 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6447 | if (val < 0) |
6448 | return 0; | |
15dbf27c | 6449 | |
7b4b6658 PZ |
6450 | nr = div64_u64(period + val, period); |
6451 | offset = nr * period; | |
6452 | val -= offset; | |
e7850595 | 6453 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6454 | goto again; |
15dbf27c | 6455 | |
7b4b6658 | 6456 | return nr; |
15dbf27c PZ |
6457 | } |
6458 | ||
0cff784a | 6459 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6460 | struct perf_sample_data *data, |
5622f295 | 6461 | struct pt_regs *regs) |
15dbf27c | 6462 | { |
cdd6c482 | 6463 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6464 | int throttle = 0; |
15dbf27c | 6465 | |
0cff784a PZ |
6466 | if (!overflow) |
6467 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6468 | |
7b4b6658 PZ |
6469 | if (hwc->interrupts == MAX_INTERRUPTS) |
6470 | return; | |
15dbf27c | 6471 | |
7b4b6658 | 6472 | for (; overflow; overflow--) { |
a8b0ca17 | 6473 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6474 | data, regs)) { |
7b4b6658 PZ |
6475 | /* |
6476 | * We inhibit the overflow from happening when | |
6477 | * hwc->interrupts == MAX_INTERRUPTS. | |
6478 | */ | |
6479 | break; | |
6480 | } | |
cf450a73 | 6481 | throttle = 1; |
7b4b6658 | 6482 | } |
15dbf27c PZ |
6483 | } |
6484 | ||
a4eaf7f1 | 6485 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6486 | struct perf_sample_data *data, |
5622f295 | 6487 | struct pt_regs *regs) |
7b4b6658 | 6488 | { |
cdd6c482 | 6489 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6490 | |
e7850595 | 6491 | local64_add(nr, &event->count); |
d6d020e9 | 6492 | |
0cff784a PZ |
6493 | if (!regs) |
6494 | return; | |
6495 | ||
6c7e550f | 6496 | if (!is_sampling_event(event)) |
7b4b6658 | 6497 | return; |
d6d020e9 | 6498 | |
5d81e5cf AV |
6499 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6500 | data->period = nr; | |
6501 | return perf_swevent_overflow(event, 1, data, regs); | |
6502 | } else | |
6503 | data->period = event->hw.last_period; | |
6504 | ||
0cff784a | 6505 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6506 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6507 | |
e7850595 | 6508 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6509 | return; |
df1a132b | 6510 | |
a8b0ca17 | 6511 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6512 | } |
6513 | ||
f5ffe02e FW |
6514 | static int perf_exclude_event(struct perf_event *event, |
6515 | struct pt_regs *regs) | |
6516 | { | |
a4eaf7f1 | 6517 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6518 | return 1; |
a4eaf7f1 | 6519 | |
f5ffe02e FW |
6520 | if (regs) { |
6521 | if (event->attr.exclude_user && user_mode(regs)) | |
6522 | return 1; | |
6523 | ||
6524 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6525 | return 1; | |
6526 | } | |
6527 | ||
6528 | return 0; | |
6529 | } | |
6530 | ||
cdd6c482 | 6531 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6532 | enum perf_type_id type, |
6fb2915d LZ |
6533 | u32 event_id, |
6534 | struct perf_sample_data *data, | |
6535 | struct pt_regs *regs) | |
15dbf27c | 6536 | { |
cdd6c482 | 6537 | if (event->attr.type != type) |
a21ca2ca | 6538 | return 0; |
f5ffe02e | 6539 | |
cdd6c482 | 6540 | if (event->attr.config != event_id) |
15dbf27c PZ |
6541 | return 0; |
6542 | ||
f5ffe02e FW |
6543 | if (perf_exclude_event(event, regs)) |
6544 | return 0; | |
15dbf27c PZ |
6545 | |
6546 | return 1; | |
6547 | } | |
6548 | ||
76e1d904 FW |
6549 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6550 | { | |
6551 | u64 val = event_id | (type << 32); | |
6552 | ||
6553 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6554 | } | |
6555 | ||
49f135ed FW |
6556 | static inline struct hlist_head * |
6557 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6558 | { |
49f135ed FW |
6559 | u64 hash = swevent_hash(type, event_id); |
6560 | ||
6561 | return &hlist->heads[hash]; | |
6562 | } | |
76e1d904 | 6563 | |
49f135ed FW |
6564 | /* For the read side: events when they trigger */ |
6565 | static inline struct hlist_head * | |
b28ab83c | 6566 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6567 | { |
6568 | struct swevent_hlist *hlist; | |
76e1d904 | 6569 | |
b28ab83c | 6570 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6571 | if (!hlist) |
6572 | return NULL; | |
6573 | ||
49f135ed FW |
6574 | return __find_swevent_head(hlist, type, event_id); |
6575 | } | |
6576 | ||
6577 | /* For the event head insertion and removal in the hlist */ | |
6578 | static inline struct hlist_head * | |
b28ab83c | 6579 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6580 | { |
6581 | struct swevent_hlist *hlist; | |
6582 | u32 event_id = event->attr.config; | |
6583 | u64 type = event->attr.type; | |
6584 | ||
6585 | /* | |
6586 | * Event scheduling is always serialized against hlist allocation | |
6587 | * and release. Which makes the protected version suitable here. | |
6588 | * The context lock guarantees that. | |
6589 | */ | |
b28ab83c | 6590 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6591 | lockdep_is_held(&event->ctx->lock)); |
6592 | if (!hlist) | |
6593 | return NULL; | |
6594 | ||
6595 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6596 | } |
6597 | ||
6598 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6599 | u64 nr, |
76e1d904 FW |
6600 | struct perf_sample_data *data, |
6601 | struct pt_regs *regs) | |
15dbf27c | 6602 | { |
4a32fea9 | 6603 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6604 | struct perf_event *event; |
76e1d904 | 6605 | struct hlist_head *head; |
15dbf27c | 6606 | |
76e1d904 | 6607 | rcu_read_lock(); |
b28ab83c | 6608 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6609 | if (!head) |
6610 | goto end; | |
6611 | ||
b67bfe0d | 6612 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6613 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6614 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6615 | } |
76e1d904 FW |
6616 | end: |
6617 | rcu_read_unlock(); | |
15dbf27c PZ |
6618 | } |
6619 | ||
86038c5e PZI |
6620 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6621 | ||
4ed7c92d | 6622 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6623 | { |
4a32fea9 | 6624 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6625 | |
b28ab83c | 6626 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6627 | } |
645e8cc0 | 6628 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6629 | |
fa9f90be | 6630 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6631 | { |
4a32fea9 | 6632 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6633 | |
b28ab83c | 6634 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6635 | } |
15dbf27c | 6636 | |
86038c5e | 6637 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6638 | { |
a4234bfc | 6639 | struct perf_sample_data data; |
4ed7c92d | 6640 | |
86038c5e | 6641 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6642 | return; |
a4234bfc | 6643 | |
fd0d000b | 6644 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6645 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6646 | } |
6647 | ||
6648 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6649 | { | |
6650 | int rctx; | |
6651 | ||
6652 | preempt_disable_notrace(); | |
6653 | rctx = perf_swevent_get_recursion_context(); | |
6654 | if (unlikely(rctx < 0)) | |
6655 | goto fail; | |
6656 | ||
6657 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6658 | |
6659 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6660 | fail: |
1c024eca | 6661 | preempt_enable_notrace(); |
b8e83514 PZ |
6662 | } |
6663 | ||
cdd6c482 | 6664 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6665 | { |
15dbf27c PZ |
6666 | } |
6667 | ||
a4eaf7f1 | 6668 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6669 | { |
4a32fea9 | 6670 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6671 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6672 | struct hlist_head *head; |
6673 | ||
6c7e550f | 6674 | if (is_sampling_event(event)) { |
7b4b6658 | 6675 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6676 | perf_swevent_set_period(event); |
7b4b6658 | 6677 | } |
76e1d904 | 6678 | |
a4eaf7f1 PZ |
6679 | hwc->state = !(flags & PERF_EF_START); |
6680 | ||
b28ab83c | 6681 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6682 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6683 | return -EINVAL; |
6684 | ||
6685 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6686 | perf_event_update_userpage(event); |
76e1d904 | 6687 | |
15dbf27c PZ |
6688 | return 0; |
6689 | } | |
6690 | ||
a4eaf7f1 | 6691 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6692 | { |
76e1d904 | 6693 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6694 | } |
6695 | ||
a4eaf7f1 | 6696 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6697 | { |
a4eaf7f1 | 6698 | event->hw.state = 0; |
d6d020e9 | 6699 | } |
aa9c4c0f | 6700 | |
a4eaf7f1 | 6701 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6702 | { |
a4eaf7f1 | 6703 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6704 | } |
6705 | ||
49f135ed FW |
6706 | /* Deref the hlist from the update side */ |
6707 | static inline struct swevent_hlist * | |
b28ab83c | 6708 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6709 | { |
b28ab83c PZ |
6710 | return rcu_dereference_protected(swhash->swevent_hlist, |
6711 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6712 | } |
6713 | ||
b28ab83c | 6714 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6715 | { |
b28ab83c | 6716 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6717 | |
49f135ed | 6718 | if (!hlist) |
76e1d904 FW |
6719 | return; |
6720 | ||
70691d4a | 6721 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6722 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6723 | } |
6724 | ||
6725 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6726 | { | |
b28ab83c | 6727 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6728 | |
b28ab83c | 6729 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6730 | |
b28ab83c PZ |
6731 | if (!--swhash->hlist_refcount) |
6732 | swevent_hlist_release(swhash); | |
76e1d904 | 6733 | |
b28ab83c | 6734 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6735 | } |
6736 | ||
6737 | static void swevent_hlist_put(struct perf_event *event) | |
6738 | { | |
6739 | int cpu; | |
6740 | ||
76e1d904 FW |
6741 | for_each_possible_cpu(cpu) |
6742 | swevent_hlist_put_cpu(event, cpu); | |
6743 | } | |
6744 | ||
6745 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6746 | { | |
b28ab83c | 6747 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6748 | int err = 0; |
6749 | ||
b28ab83c | 6750 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6751 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6752 | struct swevent_hlist *hlist; |
6753 | ||
6754 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6755 | if (!hlist) { | |
6756 | err = -ENOMEM; | |
6757 | goto exit; | |
6758 | } | |
b28ab83c | 6759 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6760 | } |
b28ab83c | 6761 | swhash->hlist_refcount++; |
9ed6060d | 6762 | exit: |
b28ab83c | 6763 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6764 | |
6765 | return err; | |
6766 | } | |
6767 | ||
6768 | static int swevent_hlist_get(struct perf_event *event) | |
6769 | { | |
6770 | int err; | |
6771 | int cpu, failed_cpu; | |
6772 | ||
76e1d904 FW |
6773 | get_online_cpus(); |
6774 | for_each_possible_cpu(cpu) { | |
6775 | err = swevent_hlist_get_cpu(event, cpu); | |
6776 | if (err) { | |
6777 | failed_cpu = cpu; | |
6778 | goto fail; | |
6779 | } | |
6780 | } | |
6781 | put_online_cpus(); | |
6782 | ||
6783 | return 0; | |
9ed6060d | 6784 | fail: |
76e1d904 FW |
6785 | for_each_possible_cpu(cpu) { |
6786 | if (cpu == failed_cpu) | |
6787 | break; | |
6788 | swevent_hlist_put_cpu(event, cpu); | |
6789 | } | |
6790 | ||
6791 | put_online_cpus(); | |
6792 | return err; | |
6793 | } | |
6794 | ||
c5905afb | 6795 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6796 | |
b0a873eb PZ |
6797 | static void sw_perf_event_destroy(struct perf_event *event) |
6798 | { | |
6799 | u64 event_id = event->attr.config; | |
95476b64 | 6800 | |
b0a873eb PZ |
6801 | WARN_ON(event->parent); |
6802 | ||
c5905afb | 6803 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6804 | swevent_hlist_put(event); |
6805 | } | |
6806 | ||
6807 | static int perf_swevent_init(struct perf_event *event) | |
6808 | { | |
8176cced | 6809 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6810 | |
6811 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6812 | return -ENOENT; | |
6813 | ||
2481c5fa SE |
6814 | /* |
6815 | * no branch sampling for software events | |
6816 | */ | |
6817 | if (has_branch_stack(event)) | |
6818 | return -EOPNOTSUPP; | |
6819 | ||
b0a873eb PZ |
6820 | switch (event_id) { |
6821 | case PERF_COUNT_SW_CPU_CLOCK: | |
6822 | case PERF_COUNT_SW_TASK_CLOCK: | |
6823 | return -ENOENT; | |
6824 | ||
6825 | default: | |
6826 | break; | |
6827 | } | |
6828 | ||
ce677831 | 6829 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6830 | return -ENOENT; |
6831 | ||
6832 | if (!event->parent) { | |
6833 | int err; | |
6834 | ||
6835 | err = swevent_hlist_get(event); | |
6836 | if (err) | |
6837 | return err; | |
6838 | ||
c5905afb | 6839 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6840 | event->destroy = sw_perf_event_destroy; |
6841 | } | |
6842 | ||
6843 | return 0; | |
6844 | } | |
6845 | ||
6846 | static struct pmu perf_swevent = { | |
89a1e187 | 6847 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6848 | |
34f43927 PZ |
6849 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6850 | ||
b0a873eb | 6851 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6852 | .add = perf_swevent_add, |
6853 | .del = perf_swevent_del, | |
6854 | .start = perf_swevent_start, | |
6855 | .stop = perf_swevent_stop, | |
1c024eca | 6856 | .read = perf_swevent_read, |
1c024eca PZ |
6857 | }; |
6858 | ||
b0a873eb PZ |
6859 | #ifdef CONFIG_EVENT_TRACING |
6860 | ||
1c024eca PZ |
6861 | static int perf_tp_filter_match(struct perf_event *event, |
6862 | struct perf_sample_data *data) | |
6863 | { | |
6864 | void *record = data->raw->data; | |
6865 | ||
b71b437e PZ |
6866 | /* only top level events have filters set */ |
6867 | if (event->parent) | |
6868 | event = event->parent; | |
6869 | ||
1c024eca PZ |
6870 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6871 | return 1; | |
6872 | return 0; | |
6873 | } | |
6874 | ||
6875 | static int perf_tp_event_match(struct perf_event *event, | |
6876 | struct perf_sample_data *data, | |
6877 | struct pt_regs *regs) | |
6878 | { | |
a0f7d0f7 FW |
6879 | if (event->hw.state & PERF_HES_STOPPED) |
6880 | return 0; | |
580d607c PZ |
6881 | /* |
6882 | * All tracepoints are from kernel-space. | |
6883 | */ | |
6884 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6885 | return 0; |
6886 | ||
6887 | if (!perf_tp_filter_match(event, data)) | |
6888 | return 0; | |
6889 | ||
6890 | return 1; | |
6891 | } | |
6892 | ||
6893 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6894 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6895 | struct task_struct *task) | |
95476b64 FW |
6896 | { |
6897 | struct perf_sample_data data; | |
1c024eca | 6898 | struct perf_event *event; |
1c024eca | 6899 | |
95476b64 FW |
6900 | struct perf_raw_record raw = { |
6901 | .size = entry_size, | |
6902 | .data = record, | |
6903 | }; | |
6904 | ||
fd0d000b | 6905 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6906 | data.raw = &raw; |
6907 | ||
b67bfe0d | 6908 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6909 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6910 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6911 | } |
ecc55f84 | 6912 | |
e6dab5ff AV |
6913 | /* |
6914 | * If we got specified a target task, also iterate its context and | |
6915 | * deliver this event there too. | |
6916 | */ | |
6917 | if (task && task != current) { | |
6918 | struct perf_event_context *ctx; | |
6919 | struct trace_entry *entry = record; | |
6920 | ||
6921 | rcu_read_lock(); | |
6922 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6923 | if (!ctx) | |
6924 | goto unlock; | |
6925 | ||
6926 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6927 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6928 | continue; | |
6929 | if (event->attr.config != entry->type) | |
6930 | continue; | |
6931 | if (perf_tp_event_match(event, &data, regs)) | |
6932 | perf_swevent_event(event, count, &data, regs); | |
6933 | } | |
6934 | unlock: | |
6935 | rcu_read_unlock(); | |
6936 | } | |
6937 | ||
ecc55f84 | 6938 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6939 | } |
6940 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6941 | ||
cdd6c482 | 6942 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6943 | { |
1c024eca | 6944 | perf_trace_destroy(event); |
e077df4f PZ |
6945 | } |
6946 | ||
b0a873eb | 6947 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6948 | { |
76e1d904 FW |
6949 | int err; |
6950 | ||
b0a873eb PZ |
6951 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6952 | return -ENOENT; | |
6953 | ||
2481c5fa SE |
6954 | /* |
6955 | * no branch sampling for tracepoint events | |
6956 | */ | |
6957 | if (has_branch_stack(event)) | |
6958 | return -EOPNOTSUPP; | |
6959 | ||
1c024eca PZ |
6960 | err = perf_trace_init(event); |
6961 | if (err) | |
b0a873eb | 6962 | return err; |
e077df4f | 6963 | |
cdd6c482 | 6964 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6965 | |
b0a873eb PZ |
6966 | return 0; |
6967 | } | |
6968 | ||
6969 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6970 | .task_ctx_nr = perf_sw_context, |
6971 | ||
b0a873eb | 6972 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6973 | .add = perf_trace_add, |
6974 | .del = perf_trace_del, | |
6975 | .start = perf_swevent_start, | |
6976 | .stop = perf_swevent_stop, | |
b0a873eb | 6977 | .read = perf_swevent_read, |
b0a873eb PZ |
6978 | }; |
6979 | ||
6980 | static inline void perf_tp_register(void) | |
6981 | { | |
2e80a82a | 6982 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6983 | } |
6fb2915d LZ |
6984 | |
6985 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6986 | { | |
6987 | char *filter_str; | |
6988 | int ret; | |
6989 | ||
6990 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6991 | return -EINVAL; | |
6992 | ||
6993 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6994 | if (IS_ERR(filter_str)) | |
6995 | return PTR_ERR(filter_str); | |
6996 | ||
6997 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6998 | ||
6999 | kfree(filter_str); | |
7000 | return ret; | |
7001 | } | |
7002 | ||
7003 | static void perf_event_free_filter(struct perf_event *event) | |
7004 | { | |
7005 | ftrace_profile_free_filter(event); | |
7006 | } | |
7007 | ||
2541517c AS |
7008 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7009 | { | |
7010 | struct bpf_prog *prog; | |
7011 | ||
7012 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7013 | return -EINVAL; | |
7014 | ||
7015 | if (event->tp_event->prog) | |
7016 | return -EEXIST; | |
7017 | ||
04a22fae WN |
7018 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7019 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7020 | return -EINVAL; |
7021 | ||
7022 | prog = bpf_prog_get(prog_fd); | |
7023 | if (IS_ERR(prog)) | |
7024 | return PTR_ERR(prog); | |
7025 | ||
6c373ca8 | 7026 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7027 | /* valid fd, but invalid bpf program type */ |
7028 | bpf_prog_put(prog); | |
7029 | return -EINVAL; | |
7030 | } | |
7031 | ||
7032 | event->tp_event->prog = prog; | |
7033 | ||
7034 | return 0; | |
7035 | } | |
7036 | ||
7037 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7038 | { | |
7039 | struct bpf_prog *prog; | |
7040 | ||
7041 | if (!event->tp_event) | |
7042 | return; | |
7043 | ||
7044 | prog = event->tp_event->prog; | |
7045 | if (prog) { | |
7046 | event->tp_event->prog = NULL; | |
7047 | bpf_prog_put(prog); | |
7048 | } | |
7049 | } | |
7050 | ||
e077df4f | 7051 | #else |
6fb2915d | 7052 | |
b0a873eb | 7053 | static inline void perf_tp_register(void) |
e077df4f | 7054 | { |
e077df4f | 7055 | } |
6fb2915d LZ |
7056 | |
7057 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7058 | { | |
7059 | return -ENOENT; | |
7060 | } | |
7061 | ||
7062 | static void perf_event_free_filter(struct perf_event *event) | |
7063 | { | |
7064 | } | |
7065 | ||
2541517c AS |
7066 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7067 | { | |
7068 | return -ENOENT; | |
7069 | } | |
7070 | ||
7071 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7072 | { | |
7073 | } | |
07b139c8 | 7074 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7075 | |
24f1e32c | 7076 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7077 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7078 | { |
f5ffe02e FW |
7079 | struct perf_sample_data sample; |
7080 | struct pt_regs *regs = data; | |
7081 | ||
fd0d000b | 7082 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7083 | |
a4eaf7f1 | 7084 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7085 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7086 | } |
7087 | #endif | |
7088 | ||
b0a873eb PZ |
7089 | /* |
7090 | * hrtimer based swevent callback | |
7091 | */ | |
f29ac756 | 7092 | |
b0a873eb | 7093 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7094 | { |
b0a873eb PZ |
7095 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7096 | struct perf_sample_data data; | |
7097 | struct pt_regs *regs; | |
7098 | struct perf_event *event; | |
7099 | u64 period; | |
f29ac756 | 7100 | |
b0a873eb | 7101 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7102 | |
7103 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7104 | return HRTIMER_NORESTART; | |
7105 | ||
b0a873eb | 7106 | event->pmu->read(event); |
f344011c | 7107 | |
fd0d000b | 7108 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7109 | regs = get_irq_regs(); |
7110 | ||
7111 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7112 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7113 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7114 | ret = HRTIMER_NORESTART; |
7115 | } | |
24f1e32c | 7116 | |
b0a873eb PZ |
7117 | period = max_t(u64, 10000, event->hw.sample_period); |
7118 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7119 | |
b0a873eb | 7120 | return ret; |
f29ac756 PZ |
7121 | } |
7122 | ||
b0a873eb | 7123 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7124 | { |
b0a873eb | 7125 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7126 | s64 period; |
7127 | ||
7128 | if (!is_sampling_event(event)) | |
7129 | return; | |
f5ffe02e | 7130 | |
5d508e82 FBH |
7131 | period = local64_read(&hwc->period_left); |
7132 | if (period) { | |
7133 | if (period < 0) | |
7134 | period = 10000; | |
fa407f35 | 7135 | |
5d508e82 FBH |
7136 | local64_set(&hwc->period_left, 0); |
7137 | } else { | |
7138 | period = max_t(u64, 10000, hwc->sample_period); | |
7139 | } | |
3497d206 TG |
7140 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7141 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7142 | } |
b0a873eb PZ |
7143 | |
7144 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7145 | { |
b0a873eb PZ |
7146 | struct hw_perf_event *hwc = &event->hw; |
7147 | ||
6c7e550f | 7148 | if (is_sampling_event(event)) { |
b0a873eb | 7149 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7150 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7151 | |
7152 | hrtimer_cancel(&hwc->hrtimer); | |
7153 | } | |
24f1e32c FW |
7154 | } |
7155 | ||
ba3dd36c PZ |
7156 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7157 | { | |
7158 | struct hw_perf_event *hwc = &event->hw; | |
7159 | ||
7160 | if (!is_sampling_event(event)) | |
7161 | return; | |
7162 | ||
7163 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7164 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7165 | ||
7166 | /* | |
7167 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7168 | * mapping and avoid the whole period adjust feedback stuff. | |
7169 | */ | |
7170 | if (event->attr.freq) { | |
7171 | long freq = event->attr.sample_freq; | |
7172 | ||
7173 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7174 | hwc->sample_period = event->attr.sample_period; | |
7175 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7176 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7177 | event->attr.freq = 0; |
7178 | } | |
7179 | } | |
7180 | ||
b0a873eb PZ |
7181 | /* |
7182 | * Software event: cpu wall time clock | |
7183 | */ | |
7184 | ||
7185 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7186 | { |
b0a873eb PZ |
7187 | s64 prev; |
7188 | u64 now; | |
7189 | ||
a4eaf7f1 | 7190 | now = local_clock(); |
b0a873eb PZ |
7191 | prev = local64_xchg(&event->hw.prev_count, now); |
7192 | local64_add(now - prev, &event->count); | |
24f1e32c | 7193 | } |
24f1e32c | 7194 | |
a4eaf7f1 | 7195 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7196 | { |
a4eaf7f1 | 7197 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7198 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7199 | } |
7200 | ||
a4eaf7f1 | 7201 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7202 | { |
b0a873eb PZ |
7203 | perf_swevent_cancel_hrtimer(event); |
7204 | cpu_clock_event_update(event); | |
7205 | } | |
f29ac756 | 7206 | |
a4eaf7f1 PZ |
7207 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7208 | { | |
7209 | if (flags & PERF_EF_START) | |
7210 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7211 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7212 | |
7213 | return 0; | |
7214 | } | |
7215 | ||
7216 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7217 | { | |
7218 | cpu_clock_event_stop(event, flags); | |
7219 | } | |
7220 | ||
b0a873eb PZ |
7221 | static void cpu_clock_event_read(struct perf_event *event) |
7222 | { | |
7223 | cpu_clock_event_update(event); | |
7224 | } | |
f344011c | 7225 | |
b0a873eb PZ |
7226 | static int cpu_clock_event_init(struct perf_event *event) |
7227 | { | |
7228 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7229 | return -ENOENT; | |
7230 | ||
7231 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7232 | return -ENOENT; | |
7233 | ||
2481c5fa SE |
7234 | /* |
7235 | * no branch sampling for software events | |
7236 | */ | |
7237 | if (has_branch_stack(event)) | |
7238 | return -EOPNOTSUPP; | |
7239 | ||
ba3dd36c PZ |
7240 | perf_swevent_init_hrtimer(event); |
7241 | ||
b0a873eb | 7242 | return 0; |
f29ac756 PZ |
7243 | } |
7244 | ||
b0a873eb | 7245 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7246 | .task_ctx_nr = perf_sw_context, |
7247 | ||
34f43927 PZ |
7248 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7249 | ||
b0a873eb | 7250 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7251 | .add = cpu_clock_event_add, |
7252 | .del = cpu_clock_event_del, | |
7253 | .start = cpu_clock_event_start, | |
7254 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7255 | .read = cpu_clock_event_read, |
7256 | }; | |
7257 | ||
7258 | /* | |
7259 | * Software event: task time clock | |
7260 | */ | |
7261 | ||
7262 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7263 | { |
b0a873eb PZ |
7264 | u64 prev; |
7265 | s64 delta; | |
5c92d124 | 7266 | |
b0a873eb PZ |
7267 | prev = local64_xchg(&event->hw.prev_count, now); |
7268 | delta = now - prev; | |
7269 | local64_add(delta, &event->count); | |
7270 | } | |
5c92d124 | 7271 | |
a4eaf7f1 | 7272 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7273 | { |
a4eaf7f1 | 7274 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7275 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7276 | } |
7277 | ||
a4eaf7f1 | 7278 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7279 | { |
7280 | perf_swevent_cancel_hrtimer(event); | |
7281 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7282 | } |
7283 | ||
7284 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7285 | { | |
7286 | if (flags & PERF_EF_START) | |
7287 | task_clock_event_start(event, flags); | |
6a694a60 | 7288 | perf_event_update_userpage(event); |
b0a873eb | 7289 | |
a4eaf7f1 PZ |
7290 | return 0; |
7291 | } | |
7292 | ||
7293 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7294 | { | |
7295 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7296 | } |
7297 | ||
7298 | static void task_clock_event_read(struct perf_event *event) | |
7299 | { | |
768a06e2 PZ |
7300 | u64 now = perf_clock(); |
7301 | u64 delta = now - event->ctx->timestamp; | |
7302 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7303 | |
7304 | task_clock_event_update(event, time); | |
7305 | } | |
7306 | ||
7307 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7308 | { |
b0a873eb PZ |
7309 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7310 | return -ENOENT; | |
7311 | ||
7312 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7313 | return -ENOENT; | |
7314 | ||
2481c5fa SE |
7315 | /* |
7316 | * no branch sampling for software events | |
7317 | */ | |
7318 | if (has_branch_stack(event)) | |
7319 | return -EOPNOTSUPP; | |
7320 | ||
ba3dd36c PZ |
7321 | perf_swevent_init_hrtimer(event); |
7322 | ||
b0a873eb | 7323 | return 0; |
6fb2915d LZ |
7324 | } |
7325 | ||
b0a873eb | 7326 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7327 | .task_ctx_nr = perf_sw_context, |
7328 | ||
34f43927 PZ |
7329 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7330 | ||
b0a873eb | 7331 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7332 | .add = task_clock_event_add, |
7333 | .del = task_clock_event_del, | |
7334 | .start = task_clock_event_start, | |
7335 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7336 | .read = task_clock_event_read, |
7337 | }; | |
6fb2915d | 7338 | |
ad5133b7 | 7339 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7340 | { |
e077df4f | 7341 | } |
6fb2915d | 7342 | |
fbbe0701 SB |
7343 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7344 | { | |
7345 | } | |
7346 | ||
ad5133b7 | 7347 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7348 | { |
ad5133b7 | 7349 | return 0; |
6fb2915d LZ |
7350 | } |
7351 | ||
18ab2cd3 | 7352 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7353 | |
7354 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7355 | { |
fbbe0701 SB |
7356 | __this_cpu_write(nop_txn_flags, flags); |
7357 | ||
7358 | if (flags & ~PERF_PMU_TXN_ADD) | |
7359 | return; | |
7360 | ||
ad5133b7 | 7361 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7362 | } |
7363 | ||
ad5133b7 PZ |
7364 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7365 | { | |
fbbe0701 SB |
7366 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7367 | ||
7368 | __this_cpu_write(nop_txn_flags, 0); | |
7369 | ||
7370 | if (flags & ~PERF_PMU_TXN_ADD) | |
7371 | return 0; | |
7372 | ||
ad5133b7 PZ |
7373 | perf_pmu_enable(pmu); |
7374 | return 0; | |
7375 | } | |
e077df4f | 7376 | |
ad5133b7 | 7377 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7378 | { |
fbbe0701 SB |
7379 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7380 | ||
7381 | __this_cpu_write(nop_txn_flags, 0); | |
7382 | ||
7383 | if (flags & ~PERF_PMU_TXN_ADD) | |
7384 | return; | |
7385 | ||
ad5133b7 | 7386 | perf_pmu_enable(pmu); |
24f1e32c FW |
7387 | } |
7388 | ||
35edc2a5 PZ |
7389 | static int perf_event_idx_default(struct perf_event *event) |
7390 | { | |
c719f560 | 7391 | return 0; |
35edc2a5 PZ |
7392 | } |
7393 | ||
8dc85d54 PZ |
7394 | /* |
7395 | * Ensures all contexts with the same task_ctx_nr have the same | |
7396 | * pmu_cpu_context too. | |
7397 | */ | |
9e317041 | 7398 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7399 | { |
8dc85d54 | 7400 | struct pmu *pmu; |
b326e956 | 7401 | |
8dc85d54 PZ |
7402 | if (ctxn < 0) |
7403 | return NULL; | |
24f1e32c | 7404 | |
8dc85d54 PZ |
7405 | list_for_each_entry(pmu, &pmus, entry) { |
7406 | if (pmu->task_ctx_nr == ctxn) | |
7407 | return pmu->pmu_cpu_context; | |
7408 | } | |
24f1e32c | 7409 | |
8dc85d54 | 7410 | return NULL; |
24f1e32c FW |
7411 | } |
7412 | ||
51676957 | 7413 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7414 | { |
51676957 PZ |
7415 | int cpu; |
7416 | ||
7417 | for_each_possible_cpu(cpu) { | |
7418 | struct perf_cpu_context *cpuctx; | |
7419 | ||
7420 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7421 | ||
3f1f3320 PZ |
7422 | if (cpuctx->unique_pmu == old_pmu) |
7423 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7424 | } |
7425 | } | |
7426 | ||
7427 | static void free_pmu_context(struct pmu *pmu) | |
7428 | { | |
7429 | struct pmu *i; | |
f5ffe02e | 7430 | |
8dc85d54 | 7431 | mutex_lock(&pmus_lock); |
0475f9ea | 7432 | /* |
8dc85d54 | 7433 | * Like a real lame refcount. |
0475f9ea | 7434 | */ |
51676957 PZ |
7435 | list_for_each_entry(i, &pmus, entry) { |
7436 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7437 | update_pmu_context(i, pmu); | |
8dc85d54 | 7438 | goto out; |
51676957 | 7439 | } |
8dc85d54 | 7440 | } |
d6d020e9 | 7441 | |
51676957 | 7442 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7443 | out: |
7444 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7445 | } |
2e80a82a | 7446 | static struct idr pmu_idr; |
d6d020e9 | 7447 | |
abe43400 PZ |
7448 | static ssize_t |
7449 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7450 | { | |
7451 | struct pmu *pmu = dev_get_drvdata(dev); | |
7452 | ||
7453 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7454 | } | |
90826ca7 | 7455 | static DEVICE_ATTR_RO(type); |
abe43400 | 7456 | |
62b85639 SE |
7457 | static ssize_t |
7458 | perf_event_mux_interval_ms_show(struct device *dev, | |
7459 | struct device_attribute *attr, | |
7460 | char *page) | |
7461 | { | |
7462 | struct pmu *pmu = dev_get_drvdata(dev); | |
7463 | ||
7464 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7465 | } | |
7466 | ||
272325c4 PZ |
7467 | static DEFINE_MUTEX(mux_interval_mutex); |
7468 | ||
62b85639 SE |
7469 | static ssize_t |
7470 | perf_event_mux_interval_ms_store(struct device *dev, | |
7471 | struct device_attribute *attr, | |
7472 | const char *buf, size_t count) | |
7473 | { | |
7474 | struct pmu *pmu = dev_get_drvdata(dev); | |
7475 | int timer, cpu, ret; | |
7476 | ||
7477 | ret = kstrtoint(buf, 0, &timer); | |
7478 | if (ret) | |
7479 | return ret; | |
7480 | ||
7481 | if (timer < 1) | |
7482 | return -EINVAL; | |
7483 | ||
7484 | /* same value, noting to do */ | |
7485 | if (timer == pmu->hrtimer_interval_ms) | |
7486 | return count; | |
7487 | ||
272325c4 | 7488 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7489 | pmu->hrtimer_interval_ms = timer; |
7490 | ||
7491 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7492 | get_online_cpus(); |
7493 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7494 | struct perf_cpu_context *cpuctx; |
7495 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7496 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7497 | ||
272325c4 PZ |
7498 | cpu_function_call(cpu, |
7499 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7500 | } |
272325c4 PZ |
7501 | put_online_cpus(); |
7502 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7503 | |
7504 | return count; | |
7505 | } | |
90826ca7 | 7506 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7507 | |
90826ca7 GKH |
7508 | static struct attribute *pmu_dev_attrs[] = { |
7509 | &dev_attr_type.attr, | |
7510 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7511 | NULL, | |
abe43400 | 7512 | }; |
90826ca7 | 7513 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7514 | |
7515 | static int pmu_bus_running; | |
7516 | static struct bus_type pmu_bus = { | |
7517 | .name = "event_source", | |
90826ca7 | 7518 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7519 | }; |
7520 | ||
7521 | static void pmu_dev_release(struct device *dev) | |
7522 | { | |
7523 | kfree(dev); | |
7524 | } | |
7525 | ||
7526 | static int pmu_dev_alloc(struct pmu *pmu) | |
7527 | { | |
7528 | int ret = -ENOMEM; | |
7529 | ||
7530 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7531 | if (!pmu->dev) | |
7532 | goto out; | |
7533 | ||
0c9d42ed | 7534 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7535 | device_initialize(pmu->dev); |
7536 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7537 | if (ret) | |
7538 | goto free_dev; | |
7539 | ||
7540 | dev_set_drvdata(pmu->dev, pmu); | |
7541 | pmu->dev->bus = &pmu_bus; | |
7542 | pmu->dev->release = pmu_dev_release; | |
7543 | ret = device_add(pmu->dev); | |
7544 | if (ret) | |
7545 | goto free_dev; | |
7546 | ||
7547 | out: | |
7548 | return ret; | |
7549 | ||
7550 | free_dev: | |
7551 | put_device(pmu->dev); | |
7552 | goto out; | |
7553 | } | |
7554 | ||
547e9fd7 | 7555 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7556 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7557 | |
03d8e80b | 7558 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7559 | { |
108b02cf | 7560 | int cpu, ret; |
24f1e32c | 7561 | |
b0a873eb | 7562 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7563 | ret = -ENOMEM; |
7564 | pmu->pmu_disable_count = alloc_percpu(int); | |
7565 | if (!pmu->pmu_disable_count) | |
7566 | goto unlock; | |
f29ac756 | 7567 | |
2e80a82a PZ |
7568 | pmu->type = -1; |
7569 | if (!name) | |
7570 | goto skip_type; | |
7571 | pmu->name = name; | |
7572 | ||
7573 | if (type < 0) { | |
0e9c3be2 TH |
7574 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7575 | if (type < 0) { | |
7576 | ret = type; | |
2e80a82a PZ |
7577 | goto free_pdc; |
7578 | } | |
7579 | } | |
7580 | pmu->type = type; | |
7581 | ||
abe43400 PZ |
7582 | if (pmu_bus_running) { |
7583 | ret = pmu_dev_alloc(pmu); | |
7584 | if (ret) | |
7585 | goto free_idr; | |
7586 | } | |
7587 | ||
2e80a82a | 7588 | skip_type: |
8dc85d54 PZ |
7589 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7590 | if (pmu->pmu_cpu_context) | |
7591 | goto got_cpu_context; | |
f29ac756 | 7592 | |
c4814202 | 7593 | ret = -ENOMEM; |
108b02cf PZ |
7594 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7595 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7596 | goto free_dev; |
f344011c | 7597 | |
108b02cf PZ |
7598 | for_each_possible_cpu(cpu) { |
7599 | struct perf_cpu_context *cpuctx; | |
7600 | ||
7601 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7602 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7603 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7604 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7605 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7606 | |
272325c4 | 7607 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7608 | |
3f1f3320 | 7609 | cpuctx->unique_pmu = pmu; |
108b02cf | 7610 | } |
76e1d904 | 7611 | |
8dc85d54 | 7612 | got_cpu_context: |
ad5133b7 PZ |
7613 | if (!pmu->start_txn) { |
7614 | if (pmu->pmu_enable) { | |
7615 | /* | |
7616 | * If we have pmu_enable/pmu_disable calls, install | |
7617 | * transaction stubs that use that to try and batch | |
7618 | * hardware accesses. | |
7619 | */ | |
7620 | pmu->start_txn = perf_pmu_start_txn; | |
7621 | pmu->commit_txn = perf_pmu_commit_txn; | |
7622 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7623 | } else { | |
fbbe0701 | 7624 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7625 | pmu->commit_txn = perf_pmu_nop_int; |
7626 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7627 | } |
5c92d124 | 7628 | } |
15dbf27c | 7629 | |
ad5133b7 PZ |
7630 | if (!pmu->pmu_enable) { |
7631 | pmu->pmu_enable = perf_pmu_nop_void; | |
7632 | pmu->pmu_disable = perf_pmu_nop_void; | |
7633 | } | |
7634 | ||
35edc2a5 PZ |
7635 | if (!pmu->event_idx) |
7636 | pmu->event_idx = perf_event_idx_default; | |
7637 | ||
b0a873eb | 7638 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7639 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7640 | ret = 0; |
7641 | unlock: | |
b0a873eb PZ |
7642 | mutex_unlock(&pmus_lock); |
7643 | ||
33696fc0 | 7644 | return ret; |
108b02cf | 7645 | |
abe43400 PZ |
7646 | free_dev: |
7647 | device_del(pmu->dev); | |
7648 | put_device(pmu->dev); | |
7649 | ||
2e80a82a PZ |
7650 | free_idr: |
7651 | if (pmu->type >= PERF_TYPE_MAX) | |
7652 | idr_remove(&pmu_idr, pmu->type); | |
7653 | ||
108b02cf PZ |
7654 | free_pdc: |
7655 | free_percpu(pmu->pmu_disable_count); | |
7656 | goto unlock; | |
f29ac756 | 7657 | } |
c464c76e | 7658 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7659 | |
b0a873eb | 7660 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7661 | { |
b0a873eb PZ |
7662 | mutex_lock(&pmus_lock); |
7663 | list_del_rcu(&pmu->entry); | |
7664 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7665 | |
0475f9ea | 7666 | /* |
cde8e884 PZ |
7667 | * We dereference the pmu list under both SRCU and regular RCU, so |
7668 | * synchronize against both of those. | |
0475f9ea | 7669 | */ |
b0a873eb | 7670 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7671 | synchronize_rcu(); |
d6d020e9 | 7672 | |
33696fc0 | 7673 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7674 | if (pmu->type >= PERF_TYPE_MAX) |
7675 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7676 | device_del(pmu->dev); |
7677 | put_device(pmu->dev); | |
51676957 | 7678 | free_pmu_context(pmu); |
b0a873eb | 7679 | } |
c464c76e | 7680 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7681 | |
cc34b98b MR |
7682 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7683 | { | |
ccd41c86 | 7684 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7685 | int ret; |
7686 | ||
7687 | if (!try_module_get(pmu->module)) | |
7688 | return -ENODEV; | |
ccd41c86 PZ |
7689 | |
7690 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7691 | /* |
7692 | * This ctx->mutex can nest when we're called through | |
7693 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7694 | */ | |
7695 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7696 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7697 | BUG_ON(!ctx); |
7698 | } | |
7699 | ||
cc34b98b MR |
7700 | event->pmu = pmu; |
7701 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7702 | |
7703 | if (ctx) | |
7704 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7705 | ||
cc34b98b MR |
7706 | if (ret) |
7707 | module_put(pmu->module); | |
7708 | ||
7709 | return ret; | |
7710 | } | |
7711 | ||
18ab2cd3 | 7712 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7713 | { |
7714 | struct pmu *pmu = NULL; | |
7715 | int idx; | |
940c5b29 | 7716 | int ret; |
b0a873eb PZ |
7717 | |
7718 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7719 | |
7720 | rcu_read_lock(); | |
7721 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7722 | rcu_read_unlock(); | |
940c5b29 | 7723 | if (pmu) { |
cc34b98b | 7724 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7725 | if (ret) |
7726 | pmu = ERR_PTR(ret); | |
2e80a82a | 7727 | goto unlock; |
940c5b29 | 7728 | } |
2e80a82a | 7729 | |
b0a873eb | 7730 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7731 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7732 | if (!ret) |
e5f4d339 | 7733 | goto unlock; |
76e1d904 | 7734 | |
b0a873eb PZ |
7735 | if (ret != -ENOENT) { |
7736 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7737 | goto unlock; |
f344011c | 7738 | } |
5c92d124 | 7739 | } |
e5f4d339 PZ |
7740 | pmu = ERR_PTR(-ENOENT); |
7741 | unlock: | |
b0a873eb | 7742 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7743 | |
4aeb0b42 | 7744 | return pmu; |
5c92d124 IM |
7745 | } |
7746 | ||
4beb31f3 FW |
7747 | static void account_event_cpu(struct perf_event *event, int cpu) |
7748 | { | |
7749 | if (event->parent) | |
7750 | return; | |
7751 | ||
4beb31f3 FW |
7752 | if (is_cgroup_event(event)) |
7753 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7754 | } | |
7755 | ||
766d6c07 FW |
7756 | static void account_event(struct perf_event *event) |
7757 | { | |
25432ae9 PZ |
7758 | bool inc = false; |
7759 | ||
4beb31f3 FW |
7760 | if (event->parent) |
7761 | return; | |
7762 | ||
766d6c07 | 7763 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7764 | inc = true; |
766d6c07 FW |
7765 | if (event->attr.mmap || event->attr.mmap_data) |
7766 | atomic_inc(&nr_mmap_events); | |
7767 | if (event->attr.comm) | |
7768 | atomic_inc(&nr_comm_events); | |
7769 | if (event->attr.task) | |
7770 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7771 | if (event->attr.freq) { |
7772 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7773 | tick_nohz_full_kick_all(); | |
7774 | } | |
45ac1403 AH |
7775 | if (event->attr.context_switch) { |
7776 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7777 | inc = true; |
45ac1403 | 7778 | } |
4beb31f3 | 7779 | if (has_branch_stack(event)) |
25432ae9 | 7780 | inc = true; |
4beb31f3 | 7781 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7782 | inc = true; |
7783 | ||
7784 | if (inc) | |
766d6c07 | 7785 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7786 | |
7787 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7788 | } |
7789 | ||
0793a61d | 7790 | /* |
cdd6c482 | 7791 | * Allocate and initialize a event structure |
0793a61d | 7792 | */ |
cdd6c482 | 7793 | static struct perf_event * |
c3f00c70 | 7794 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7795 | struct task_struct *task, |
7796 | struct perf_event *group_leader, | |
7797 | struct perf_event *parent_event, | |
4dc0da86 | 7798 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7799 | void *context, int cgroup_fd) |
0793a61d | 7800 | { |
51b0fe39 | 7801 | struct pmu *pmu; |
cdd6c482 IM |
7802 | struct perf_event *event; |
7803 | struct hw_perf_event *hwc; | |
90983b16 | 7804 | long err = -EINVAL; |
0793a61d | 7805 | |
66832eb4 ON |
7806 | if ((unsigned)cpu >= nr_cpu_ids) { |
7807 | if (!task || cpu != -1) | |
7808 | return ERR_PTR(-EINVAL); | |
7809 | } | |
7810 | ||
c3f00c70 | 7811 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7812 | if (!event) |
d5d2bc0d | 7813 | return ERR_PTR(-ENOMEM); |
0793a61d | 7814 | |
04289bb9 | 7815 | /* |
cdd6c482 | 7816 | * Single events are their own group leaders, with an |
04289bb9 IM |
7817 | * empty sibling list: |
7818 | */ | |
7819 | if (!group_leader) | |
cdd6c482 | 7820 | group_leader = event; |
04289bb9 | 7821 | |
cdd6c482 IM |
7822 | mutex_init(&event->child_mutex); |
7823 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7824 | |
cdd6c482 IM |
7825 | INIT_LIST_HEAD(&event->group_entry); |
7826 | INIT_LIST_HEAD(&event->event_entry); | |
7827 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7828 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7829 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7830 | INIT_HLIST_NODE(&event->hlist_entry); |
7831 | ||
10c6db11 | 7832 | |
cdd6c482 | 7833 | init_waitqueue_head(&event->waitq); |
e360adbe | 7834 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7835 | |
cdd6c482 | 7836 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7837 | |
a6fa941d | 7838 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7839 | event->cpu = cpu; |
7840 | event->attr = *attr; | |
7841 | event->group_leader = group_leader; | |
7842 | event->pmu = NULL; | |
cdd6c482 | 7843 | event->oncpu = -1; |
a96bbc16 | 7844 | |
cdd6c482 | 7845 | event->parent = parent_event; |
b84fbc9f | 7846 | |
17cf22c3 | 7847 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7848 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7849 | |
cdd6c482 | 7850 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7851 | |
d580ff86 PZ |
7852 | if (task) { |
7853 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7854 | /* |
50f16a8b PZ |
7855 | * XXX pmu::event_init needs to know what task to account to |
7856 | * and we cannot use the ctx information because we need the | |
7857 | * pmu before we get a ctx. | |
d580ff86 | 7858 | */ |
50f16a8b | 7859 | event->hw.target = task; |
d580ff86 PZ |
7860 | } |
7861 | ||
34f43927 PZ |
7862 | event->clock = &local_clock; |
7863 | if (parent_event) | |
7864 | event->clock = parent_event->clock; | |
7865 | ||
4dc0da86 | 7866 | if (!overflow_handler && parent_event) { |
b326e956 | 7867 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7868 | context = parent_event->overflow_handler_context; |
7869 | } | |
66832eb4 | 7870 | |
b326e956 | 7871 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7872 | event->overflow_handler_context = context; |
97eaf530 | 7873 | |
0231bb53 | 7874 | perf_event__state_init(event); |
a86ed508 | 7875 | |
4aeb0b42 | 7876 | pmu = NULL; |
b8e83514 | 7877 | |
cdd6c482 | 7878 | hwc = &event->hw; |
bd2b5b12 | 7879 | hwc->sample_period = attr->sample_period; |
0d48696f | 7880 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7881 | hwc->sample_period = 1; |
eced1dfc | 7882 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7883 | |
e7850595 | 7884 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7885 | |
2023b359 | 7886 | /* |
cdd6c482 | 7887 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7888 | */ |
3dab77fb | 7889 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7890 | goto err_ns; |
a46a2300 YZ |
7891 | |
7892 | if (!has_branch_stack(event)) | |
7893 | event->attr.branch_sample_type = 0; | |
2023b359 | 7894 | |
79dff51e MF |
7895 | if (cgroup_fd != -1) { |
7896 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7897 | if (err) | |
7898 | goto err_ns; | |
7899 | } | |
7900 | ||
b0a873eb | 7901 | pmu = perf_init_event(event); |
4aeb0b42 | 7902 | if (!pmu) |
90983b16 FW |
7903 | goto err_ns; |
7904 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7905 | err = PTR_ERR(pmu); |
90983b16 | 7906 | goto err_ns; |
621a01ea | 7907 | } |
d5d2bc0d | 7908 | |
bed5b25a AS |
7909 | err = exclusive_event_init(event); |
7910 | if (err) | |
7911 | goto err_pmu; | |
7912 | ||
cdd6c482 | 7913 | if (!event->parent) { |
927c7a9e FW |
7914 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7915 | err = get_callchain_buffers(); | |
90983b16 | 7916 | if (err) |
bed5b25a | 7917 | goto err_per_task; |
d010b332 | 7918 | } |
f344011c | 7919 | } |
9ee318a7 | 7920 | |
cdd6c482 | 7921 | return event; |
90983b16 | 7922 | |
bed5b25a AS |
7923 | err_per_task: |
7924 | exclusive_event_destroy(event); | |
7925 | ||
90983b16 FW |
7926 | err_pmu: |
7927 | if (event->destroy) | |
7928 | event->destroy(event); | |
c464c76e | 7929 | module_put(pmu->module); |
90983b16 | 7930 | err_ns: |
79dff51e MF |
7931 | if (is_cgroup_event(event)) |
7932 | perf_detach_cgroup(event); | |
90983b16 FW |
7933 | if (event->ns) |
7934 | put_pid_ns(event->ns); | |
7935 | kfree(event); | |
7936 | ||
7937 | return ERR_PTR(err); | |
0793a61d TG |
7938 | } |
7939 | ||
cdd6c482 IM |
7940 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7941 | struct perf_event_attr *attr) | |
974802ea | 7942 | { |
974802ea | 7943 | u32 size; |
cdf8073d | 7944 | int ret; |
974802ea PZ |
7945 | |
7946 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7947 | return -EFAULT; | |
7948 | ||
7949 | /* | |
7950 | * zero the full structure, so that a short copy will be nice. | |
7951 | */ | |
7952 | memset(attr, 0, sizeof(*attr)); | |
7953 | ||
7954 | ret = get_user(size, &uattr->size); | |
7955 | if (ret) | |
7956 | return ret; | |
7957 | ||
7958 | if (size > PAGE_SIZE) /* silly large */ | |
7959 | goto err_size; | |
7960 | ||
7961 | if (!size) /* abi compat */ | |
7962 | size = PERF_ATTR_SIZE_VER0; | |
7963 | ||
7964 | if (size < PERF_ATTR_SIZE_VER0) | |
7965 | goto err_size; | |
7966 | ||
7967 | /* | |
7968 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7969 | * ensure all the unknown bits are 0 - i.e. new |
7970 | * user-space does not rely on any kernel feature | |
7971 | * extensions we dont know about yet. | |
974802ea PZ |
7972 | */ |
7973 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7974 | unsigned char __user *addr; |
7975 | unsigned char __user *end; | |
7976 | unsigned char val; | |
974802ea | 7977 | |
cdf8073d IS |
7978 | addr = (void __user *)uattr + sizeof(*attr); |
7979 | end = (void __user *)uattr + size; | |
974802ea | 7980 | |
cdf8073d | 7981 | for (; addr < end; addr++) { |
974802ea PZ |
7982 | ret = get_user(val, addr); |
7983 | if (ret) | |
7984 | return ret; | |
7985 | if (val) | |
7986 | goto err_size; | |
7987 | } | |
b3e62e35 | 7988 | size = sizeof(*attr); |
974802ea PZ |
7989 | } |
7990 | ||
7991 | ret = copy_from_user(attr, uattr, size); | |
7992 | if (ret) | |
7993 | return -EFAULT; | |
7994 | ||
cd757645 | 7995 | if (attr->__reserved_1) |
974802ea PZ |
7996 | return -EINVAL; |
7997 | ||
7998 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7999 | return -EINVAL; | |
8000 | ||
8001 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8002 | return -EINVAL; | |
8003 | ||
bce38cd5 SE |
8004 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8005 | u64 mask = attr->branch_sample_type; | |
8006 | ||
8007 | /* only using defined bits */ | |
8008 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8009 | return -EINVAL; | |
8010 | ||
8011 | /* at least one branch bit must be set */ | |
8012 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8013 | return -EINVAL; | |
8014 | ||
bce38cd5 SE |
8015 | /* propagate priv level, when not set for branch */ |
8016 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8017 | ||
8018 | /* exclude_kernel checked on syscall entry */ | |
8019 | if (!attr->exclude_kernel) | |
8020 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8021 | ||
8022 | if (!attr->exclude_user) | |
8023 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8024 | ||
8025 | if (!attr->exclude_hv) | |
8026 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8027 | /* | |
8028 | * adjust user setting (for HW filter setup) | |
8029 | */ | |
8030 | attr->branch_sample_type = mask; | |
8031 | } | |
e712209a SE |
8032 | /* privileged levels capture (kernel, hv): check permissions */ |
8033 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8034 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8035 | return -EACCES; | |
bce38cd5 | 8036 | } |
4018994f | 8037 | |
c5ebcedb | 8038 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8039 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8040 | if (ret) |
8041 | return ret; | |
8042 | } | |
8043 | ||
8044 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8045 | if (!arch_perf_have_user_stack_dump()) | |
8046 | return -ENOSYS; | |
8047 | ||
8048 | /* | |
8049 | * We have __u32 type for the size, but so far | |
8050 | * we can only use __u16 as maximum due to the | |
8051 | * __u16 sample size limit. | |
8052 | */ | |
8053 | if (attr->sample_stack_user >= USHRT_MAX) | |
8054 | ret = -EINVAL; | |
8055 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8056 | ret = -EINVAL; | |
8057 | } | |
4018994f | 8058 | |
60e2364e SE |
8059 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8060 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8061 | out: |
8062 | return ret; | |
8063 | ||
8064 | err_size: | |
8065 | put_user(sizeof(*attr), &uattr->size); | |
8066 | ret = -E2BIG; | |
8067 | goto out; | |
8068 | } | |
8069 | ||
ac9721f3 PZ |
8070 | static int |
8071 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8072 | { |
b69cf536 | 8073 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8074 | int ret = -EINVAL; |
8075 | ||
ac9721f3 | 8076 | if (!output_event) |
a4be7c27 PZ |
8077 | goto set; |
8078 | ||
ac9721f3 PZ |
8079 | /* don't allow circular references */ |
8080 | if (event == output_event) | |
a4be7c27 PZ |
8081 | goto out; |
8082 | ||
0f139300 PZ |
8083 | /* |
8084 | * Don't allow cross-cpu buffers | |
8085 | */ | |
8086 | if (output_event->cpu != event->cpu) | |
8087 | goto out; | |
8088 | ||
8089 | /* | |
76369139 | 8090 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8091 | */ |
8092 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8093 | goto out; | |
8094 | ||
34f43927 PZ |
8095 | /* |
8096 | * Mixing clocks in the same buffer is trouble you don't need. | |
8097 | */ | |
8098 | if (output_event->clock != event->clock) | |
8099 | goto out; | |
8100 | ||
45bfb2e5 PZ |
8101 | /* |
8102 | * If both events generate aux data, they must be on the same PMU | |
8103 | */ | |
8104 | if (has_aux(event) && has_aux(output_event) && | |
8105 | event->pmu != output_event->pmu) | |
8106 | goto out; | |
8107 | ||
a4be7c27 | 8108 | set: |
cdd6c482 | 8109 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8110 | /* Can't redirect output if we've got an active mmap() */ |
8111 | if (atomic_read(&event->mmap_count)) | |
8112 | goto unlock; | |
a4be7c27 | 8113 | |
ac9721f3 | 8114 | if (output_event) { |
76369139 FW |
8115 | /* get the rb we want to redirect to */ |
8116 | rb = ring_buffer_get(output_event); | |
8117 | if (!rb) | |
ac9721f3 | 8118 | goto unlock; |
a4be7c27 PZ |
8119 | } |
8120 | ||
b69cf536 | 8121 | ring_buffer_attach(event, rb); |
9bb5d40c | 8122 | |
a4be7c27 | 8123 | ret = 0; |
ac9721f3 PZ |
8124 | unlock: |
8125 | mutex_unlock(&event->mmap_mutex); | |
8126 | ||
a4be7c27 | 8127 | out: |
a4be7c27 PZ |
8128 | return ret; |
8129 | } | |
8130 | ||
f63a8daa PZ |
8131 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8132 | { | |
8133 | if (b < a) | |
8134 | swap(a, b); | |
8135 | ||
8136 | mutex_lock(a); | |
8137 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8138 | } | |
8139 | ||
34f43927 PZ |
8140 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8141 | { | |
8142 | bool nmi_safe = false; | |
8143 | ||
8144 | switch (clk_id) { | |
8145 | case CLOCK_MONOTONIC: | |
8146 | event->clock = &ktime_get_mono_fast_ns; | |
8147 | nmi_safe = true; | |
8148 | break; | |
8149 | ||
8150 | case CLOCK_MONOTONIC_RAW: | |
8151 | event->clock = &ktime_get_raw_fast_ns; | |
8152 | nmi_safe = true; | |
8153 | break; | |
8154 | ||
8155 | case CLOCK_REALTIME: | |
8156 | event->clock = &ktime_get_real_ns; | |
8157 | break; | |
8158 | ||
8159 | case CLOCK_BOOTTIME: | |
8160 | event->clock = &ktime_get_boot_ns; | |
8161 | break; | |
8162 | ||
8163 | case CLOCK_TAI: | |
8164 | event->clock = &ktime_get_tai_ns; | |
8165 | break; | |
8166 | ||
8167 | default: | |
8168 | return -EINVAL; | |
8169 | } | |
8170 | ||
8171 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8172 | return -EINVAL; | |
8173 | ||
8174 | return 0; | |
8175 | } | |
8176 | ||
0793a61d | 8177 | /** |
cdd6c482 | 8178 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8179 | * |
cdd6c482 | 8180 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8181 | * @pid: target pid |
9f66a381 | 8182 | * @cpu: target cpu |
cdd6c482 | 8183 | * @group_fd: group leader event fd |
0793a61d | 8184 | */ |
cdd6c482 IM |
8185 | SYSCALL_DEFINE5(perf_event_open, |
8186 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8187 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8188 | { |
b04243ef PZ |
8189 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8190 | struct perf_event *event, *sibling; | |
cdd6c482 | 8191 | struct perf_event_attr attr; |
f63a8daa | 8192 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8193 | struct file *event_file = NULL; |
2903ff01 | 8194 | struct fd group = {NULL, 0}; |
38a81da2 | 8195 | struct task_struct *task = NULL; |
89a1e187 | 8196 | struct pmu *pmu; |
ea635c64 | 8197 | int event_fd; |
b04243ef | 8198 | int move_group = 0; |
dc86cabe | 8199 | int err; |
a21b0b35 | 8200 | int f_flags = O_RDWR; |
79dff51e | 8201 | int cgroup_fd = -1; |
0793a61d | 8202 | |
2743a5b0 | 8203 | /* for future expandability... */ |
e5d1367f | 8204 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8205 | return -EINVAL; |
8206 | ||
dc86cabe IM |
8207 | err = perf_copy_attr(attr_uptr, &attr); |
8208 | if (err) | |
8209 | return err; | |
eab656ae | 8210 | |
0764771d PZ |
8211 | if (!attr.exclude_kernel) { |
8212 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8213 | return -EACCES; | |
8214 | } | |
8215 | ||
df58ab24 | 8216 | if (attr.freq) { |
cdd6c482 | 8217 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8218 | return -EINVAL; |
0819b2e3 PZ |
8219 | } else { |
8220 | if (attr.sample_period & (1ULL << 63)) | |
8221 | return -EINVAL; | |
df58ab24 PZ |
8222 | } |
8223 | ||
e5d1367f SE |
8224 | /* |
8225 | * In cgroup mode, the pid argument is used to pass the fd | |
8226 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8227 | * designates the cpu on which to monitor threads from that | |
8228 | * cgroup. | |
8229 | */ | |
8230 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8231 | return -EINVAL; | |
8232 | ||
a21b0b35 YD |
8233 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8234 | f_flags |= O_CLOEXEC; | |
8235 | ||
8236 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8237 | if (event_fd < 0) |
8238 | return event_fd; | |
8239 | ||
ac9721f3 | 8240 | if (group_fd != -1) { |
2903ff01 AV |
8241 | err = perf_fget_light(group_fd, &group); |
8242 | if (err) | |
d14b12d7 | 8243 | goto err_fd; |
2903ff01 | 8244 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8245 | if (flags & PERF_FLAG_FD_OUTPUT) |
8246 | output_event = group_leader; | |
8247 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8248 | group_leader = NULL; | |
8249 | } | |
8250 | ||
e5d1367f | 8251 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8252 | task = find_lively_task_by_vpid(pid); |
8253 | if (IS_ERR(task)) { | |
8254 | err = PTR_ERR(task); | |
8255 | goto err_group_fd; | |
8256 | } | |
8257 | } | |
8258 | ||
1f4ee503 PZ |
8259 | if (task && group_leader && |
8260 | group_leader->attr.inherit != attr.inherit) { | |
8261 | err = -EINVAL; | |
8262 | goto err_task; | |
8263 | } | |
8264 | ||
fbfc623f YZ |
8265 | get_online_cpus(); |
8266 | ||
79dff51e MF |
8267 | if (flags & PERF_FLAG_PID_CGROUP) |
8268 | cgroup_fd = pid; | |
8269 | ||
4dc0da86 | 8270 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8271 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8272 | if (IS_ERR(event)) { |
8273 | err = PTR_ERR(event); | |
1f4ee503 | 8274 | goto err_cpus; |
d14b12d7 SE |
8275 | } |
8276 | ||
53b25335 VW |
8277 | if (is_sampling_event(event)) { |
8278 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8279 | err = -ENOTSUPP; | |
8280 | goto err_alloc; | |
8281 | } | |
8282 | } | |
8283 | ||
766d6c07 FW |
8284 | account_event(event); |
8285 | ||
89a1e187 PZ |
8286 | /* |
8287 | * Special case software events and allow them to be part of | |
8288 | * any hardware group. | |
8289 | */ | |
8290 | pmu = event->pmu; | |
b04243ef | 8291 | |
34f43927 PZ |
8292 | if (attr.use_clockid) { |
8293 | err = perf_event_set_clock(event, attr.clockid); | |
8294 | if (err) | |
8295 | goto err_alloc; | |
8296 | } | |
8297 | ||
b04243ef PZ |
8298 | if (group_leader && |
8299 | (is_software_event(event) != is_software_event(group_leader))) { | |
8300 | if (is_software_event(event)) { | |
8301 | /* | |
8302 | * If event and group_leader are not both a software | |
8303 | * event, and event is, then group leader is not. | |
8304 | * | |
8305 | * Allow the addition of software events to !software | |
8306 | * groups, this is safe because software events never | |
8307 | * fail to schedule. | |
8308 | */ | |
8309 | pmu = group_leader->pmu; | |
8310 | } else if (is_software_event(group_leader) && | |
8311 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8312 | /* | |
8313 | * In case the group is a pure software group, and we | |
8314 | * try to add a hardware event, move the whole group to | |
8315 | * the hardware context. | |
8316 | */ | |
8317 | move_group = 1; | |
8318 | } | |
8319 | } | |
89a1e187 PZ |
8320 | |
8321 | /* | |
8322 | * Get the target context (task or percpu): | |
8323 | */ | |
4af57ef2 | 8324 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8325 | if (IS_ERR(ctx)) { |
8326 | err = PTR_ERR(ctx); | |
c6be5a5c | 8327 | goto err_alloc; |
89a1e187 PZ |
8328 | } |
8329 | ||
bed5b25a AS |
8330 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8331 | err = -EBUSY; | |
8332 | goto err_context; | |
8333 | } | |
8334 | ||
fd1edb3a PZ |
8335 | if (task) { |
8336 | put_task_struct(task); | |
8337 | task = NULL; | |
8338 | } | |
8339 | ||
ccff286d | 8340 | /* |
cdd6c482 | 8341 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8342 | */ |
ac9721f3 | 8343 | if (group_leader) { |
dc86cabe | 8344 | err = -EINVAL; |
04289bb9 | 8345 | |
04289bb9 | 8346 | /* |
ccff286d IM |
8347 | * Do not allow a recursive hierarchy (this new sibling |
8348 | * becoming part of another group-sibling): | |
8349 | */ | |
8350 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8351 | goto err_context; |
34f43927 PZ |
8352 | |
8353 | /* All events in a group should have the same clock */ | |
8354 | if (group_leader->clock != event->clock) | |
8355 | goto err_context; | |
8356 | ||
ccff286d IM |
8357 | /* |
8358 | * Do not allow to attach to a group in a different | |
8359 | * task or CPU context: | |
04289bb9 | 8360 | */ |
b04243ef | 8361 | if (move_group) { |
c3c87e77 PZ |
8362 | /* |
8363 | * Make sure we're both on the same task, or both | |
8364 | * per-cpu events. | |
8365 | */ | |
8366 | if (group_leader->ctx->task != ctx->task) | |
8367 | goto err_context; | |
8368 | ||
8369 | /* | |
8370 | * Make sure we're both events for the same CPU; | |
8371 | * grouping events for different CPUs is broken; since | |
8372 | * you can never concurrently schedule them anyhow. | |
8373 | */ | |
8374 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8375 | goto err_context; |
8376 | } else { | |
8377 | if (group_leader->ctx != ctx) | |
8378 | goto err_context; | |
8379 | } | |
8380 | ||
3b6f9e5c PM |
8381 | /* |
8382 | * Only a group leader can be exclusive or pinned | |
8383 | */ | |
0d48696f | 8384 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8385 | goto err_context; |
ac9721f3 PZ |
8386 | } |
8387 | ||
8388 | if (output_event) { | |
8389 | err = perf_event_set_output(event, output_event); | |
8390 | if (err) | |
c3f00c70 | 8391 | goto err_context; |
ac9721f3 | 8392 | } |
0793a61d | 8393 | |
a21b0b35 YD |
8394 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8395 | f_flags); | |
ea635c64 AV |
8396 | if (IS_ERR(event_file)) { |
8397 | err = PTR_ERR(event_file); | |
c3f00c70 | 8398 | goto err_context; |
ea635c64 | 8399 | } |
9b51f66d | 8400 | |
b04243ef | 8401 | if (move_group) { |
f63a8daa | 8402 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8403 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8404 | } else { | |
8405 | mutex_lock(&ctx->mutex); | |
8406 | } | |
8407 | ||
a723968c PZ |
8408 | if (!perf_event_validate_size(event)) { |
8409 | err = -E2BIG; | |
8410 | goto err_locked; | |
8411 | } | |
8412 | ||
f55fc2a5 PZ |
8413 | /* |
8414 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8415 | * because we need to serialize with concurrent event creation. | |
8416 | */ | |
8417 | if (!exclusive_event_installable(event, ctx)) { | |
8418 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8419 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8420 | |
f55fc2a5 PZ |
8421 | err = -EBUSY; |
8422 | goto err_locked; | |
8423 | } | |
f63a8daa | 8424 | |
f55fc2a5 PZ |
8425 | WARN_ON_ONCE(ctx->parent_ctx); |
8426 | ||
8427 | if (move_group) { | |
f63a8daa PZ |
8428 | /* |
8429 | * See perf_event_ctx_lock() for comments on the details | |
8430 | * of swizzling perf_event::ctx. | |
8431 | */ | |
45a0e07a | 8432 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8433 | |
b04243ef PZ |
8434 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8435 | group_entry) { | |
45a0e07a | 8436 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8437 | put_ctx(gctx); |
8438 | } | |
b04243ef | 8439 | |
f63a8daa PZ |
8440 | /* |
8441 | * Wait for everybody to stop referencing the events through | |
8442 | * the old lists, before installing it on new lists. | |
8443 | */ | |
0cda4c02 | 8444 | synchronize_rcu(); |
f63a8daa | 8445 | |
8f95b435 PZI |
8446 | /* |
8447 | * Install the group siblings before the group leader. | |
8448 | * | |
8449 | * Because a group leader will try and install the entire group | |
8450 | * (through the sibling list, which is still in-tact), we can | |
8451 | * end up with siblings installed in the wrong context. | |
8452 | * | |
8453 | * By installing siblings first we NO-OP because they're not | |
8454 | * reachable through the group lists. | |
8455 | */ | |
b04243ef PZ |
8456 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8457 | group_entry) { | |
8f95b435 | 8458 | perf_event__state_init(sibling); |
9fc81d87 | 8459 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8460 | get_ctx(ctx); |
8461 | } | |
8f95b435 PZI |
8462 | |
8463 | /* | |
8464 | * Removing from the context ends up with disabled | |
8465 | * event. What we want here is event in the initial | |
8466 | * startup state, ready to be add into new context. | |
8467 | */ | |
8468 | perf_event__state_init(group_leader); | |
8469 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8470 | get_ctx(ctx); | |
b04243ef | 8471 | |
f55fc2a5 PZ |
8472 | /* |
8473 | * Now that all events are installed in @ctx, nothing | |
8474 | * references @gctx anymore, so drop the last reference we have | |
8475 | * on it. | |
8476 | */ | |
8477 | put_ctx(gctx); | |
bed5b25a AS |
8478 | } |
8479 | ||
f73e22ab PZ |
8480 | /* |
8481 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8482 | * that we're serialized against further additions and before | |
8483 | * perf_install_in_context() which is the point the event is active and | |
8484 | * can use these values. | |
8485 | */ | |
8486 | perf_event__header_size(event); | |
8487 | perf_event__id_header_size(event); | |
8488 | ||
78cd2c74 PZ |
8489 | event->owner = current; |
8490 | ||
e2d37cd2 | 8491 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8492 | perf_unpin_context(ctx); |
f63a8daa | 8493 | |
f55fc2a5 | 8494 | if (move_group) |
f63a8daa | 8495 | mutex_unlock(&gctx->mutex); |
d859e29f | 8496 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8497 | |
fbfc623f YZ |
8498 | put_online_cpus(); |
8499 | ||
cdd6c482 IM |
8500 | mutex_lock(¤t->perf_event_mutex); |
8501 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8502 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8503 | |
8a49542c PZ |
8504 | /* |
8505 | * Drop the reference on the group_event after placing the | |
8506 | * new event on the sibling_list. This ensures destruction | |
8507 | * of the group leader will find the pointer to itself in | |
8508 | * perf_group_detach(). | |
8509 | */ | |
2903ff01 | 8510 | fdput(group); |
ea635c64 AV |
8511 | fd_install(event_fd, event_file); |
8512 | return event_fd; | |
0793a61d | 8513 | |
f55fc2a5 PZ |
8514 | err_locked: |
8515 | if (move_group) | |
8516 | mutex_unlock(&gctx->mutex); | |
8517 | mutex_unlock(&ctx->mutex); | |
8518 | /* err_file: */ | |
8519 | fput(event_file); | |
c3f00c70 | 8520 | err_context: |
fe4b04fa | 8521 | perf_unpin_context(ctx); |
ea635c64 | 8522 | put_ctx(ctx); |
c6be5a5c | 8523 | err_alloc: |
ea635c64 | 8524 | free_event(event); |
1f4ee503 | 8525 | err_cpus: |
fbfc623f | 8526 | put_online_cpus(); |
1f4ee503 | 8527 | err_task: |
e7d0bc04 PZ |
8528 | if (task) |
8529 | put_task_struct(task); | |
89a1e187 | 8530 | err_group_fd: |
2903ff01 | 8531 | fdput(group); |
ea635c64 AV |
8532 | err_fd: |
8533 | put_unused_fd(event_fd); | |
dc86cabe | 8534 | return err; |
0793a61d TG |
8535 | } |
8536 | ||
fb0459d7 AV |
8537 | /** |
8538 | * perf_event_create_kernel_counter | |
8539 | * | |
8540 | * @attr: attributes of the counter to create | |
8541 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8542 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8543 | */ |
8544 | struct perf_event * | |
8545 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8546 | struct task_struct *task, |
4dc0da86 AK |
8547 | perf_overflow_handler_t overflow_handler, |
8548 | void *context) | |
fb0459d7 | 8549 | { |
fb0459d7 | 8550 | struct perf_event_context *ctx; |
c3f00c70 | 8551 | struct perf_event *event; |
fb0459d7 | 8552 | int err; |
d859e29f | 8553 | |
fb0459d7 AV |
8554 | /* |
8555 | * Get the target context (task or percpu): | |
8556 | */ | |
d859e29f | 8557 | |
4dc0da86 | 8558 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8559 | overflow_handler, context, -1); |
c3f00c70 PZ |
8560 | if (IS_ERR(event)) { |
8561 | err = PTR_ERR(event); | |
8562 | goto err; | |
8563 | } | |
d859e29f | 8564 | |
f8697762 | 8565 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8566 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8567 | |
766d6c07 FW |
8568 | account_event(event); |
8569 | ||
4af57ef2 | 8570 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8571 | if (IS_ERR(ctx)) { |
8572 | err = PTR_ERR(ctx); | |
c3f00c70 | 8573 | goto err_free; |
d859e29f | 8574 | } |
fb0459d7 | 8575 | |
fb0459d7 AV |
8576 | WARN_ON_ONCE(ctx->parent_ctx); |
8577 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8578 | if (!exclusive_event_installable(event, ctx)) { |
8579 | mutex_unlock(&ctx->mutex); | |
8580 | perf_unpin_context(ctx); | |
8581 | put_ctx(ctx); | |
8582 | err = -EBUSY; | |
8583 | goto err_free; | |
8584 | } | |
8585 | ||
fb0459d7 | 8586 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8587 | perf_unpin_context(ctx); |
fb0459d7 AV |
8588 | mutex_unlock(&ctx->mutex); |
8589 | ||
fb0459d7 AV |
8590 | return event; |
8591 | ||
c3f00c70 PZ |
8592 | err_free: |
8593 | free_event(event); | |
8594 | err: | |
c6567f64 | 8595 | return ERR_PTR(err); |
9b51f66d | 8596 | } |
fb0459d7 | 8597 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8598 | |
0cda4c02 YZ |
8599 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8600 | { | |
8601 | struct perf_event_context *src_ctx; | |
8602 | struct perf_event_context *dst_ctx; | |
8603 | struct perf_event *event, *tmp; | |
8604 | LIST_HEAD(events); | |
8605 | ||
8606 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8607 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8608 | ||
f63a8daa PZ |
8609 | /* |
8610 | * See perf_event_ctx_lock() for comments on the details | |
8611 | * of swizzling perf_event::ctx. | |
8612 | */ | |
8613 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8614 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8615 | event_entry) { | |
45a0e07a | 8616 | perf_remove_from_context(event, 0); |
9a545de0 | 8617 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8618 | put_ctx(src_ctx); |
9886167d | 8619 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8620 | } |
0cda4c02 | 8621 | |
8f95b435 PZI |
8622 | /* |
8623 | * Wait for the events to quiesce before re-instating them. | |
8624 | */ | |
0cda4c02 YZ |
8625 | synchronize_rcu(); |
8626 | ||
8f95b435 PZI |
8627 | /* |
8628 | * Re-instate events in 2 passes. | |
8629 | * | |
8630 | * Skip over group leaders and only install siblings on this first | |
8631 | * pass, siblings will not get enabled without a leader, however a | |
8632 | * leader will enable its siblings, even if those are still on the old | |
8633 | * context. | |
8634 | */ | |
8635 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8636 | if (event->group_leader == event) | |
8637 | continue; | |
8638 | ||
8639 | list_del(&event->migrate_entry); | |
8640 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8641 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8642 | account_event_cpu(event, dst_cpu); | |
8643 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8644 | get_ctx(dst_ctx); | |
8645 | } | |
8646 | ||
8647 | /* | |
8648 | * Once all the siblings are setup properly, install the group leaders | |
8649 | * to make it go. | |
8650 | */ | |
9886167d PZ |
8651 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8652 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8653 | if (event->state >= PERF_EVENT_STATE_OFF) |
8654 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8655 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8656 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8657 | get_ctx(dst_ctx); | |
8658 | } | |
8659 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8660 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8661 | } |
8662 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8663 | ||
cdd6c482 | 8664 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8665 | struct task_struct *child) |
d859e29f | 8666 | { |
cdd6c482 | 8667 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8668 | u64 child_val; |
d859e29f | 8669 | |
cdd6c482 IM |
8670 | if (child_event->attr.inherit_stat) |
8671 | perf_event_read_event(child_event, child); | |
38b200d6 | 8672 | |
b5e58793 | 8673 | child_val = perf_event_count(child_event); |
d859e29f PM |
8674 | |
8675 | /* | |
8676 | * Add back the child's count to the parent's count: | |
8677 | */ | |
a6e6dea6 | 8678 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8679 | atomic64_add(child_event->total_time_enabled, |
8680 | &parent_event->child_total_time_enabled); | |
8681 | atomic64_add(child_event->total_time_running, | |
8682 | &parent_event->child_total_time_running); | |
d859e29f PM |
8683 | } |
8684 | ||
9b51f66d | 8685 | static void |
8ba289b8 PZ |
8686 | perf_event_exit_event(struct perf_event *child_event, |
8687 | struct perf_event_context *child_ctx, | |
8688 | struct task_struct *child) | |
9b51f66d | 8689 | { |
8ba289b8 PZ |
8690 | struct perf_event *parent_event = child_event->parent; |
8691 | ||
1903d50c PZ |
8692 | /* |
8693 | * Do not destroy the 'original' grouping; because of the context | |
8694 | * switch optimization the original events could've ended up in a | |
8695 | * random child task. | |
8696 | * | |
8697 | * If we were to destroy the original group, all group related | |
8698 | * operations would cease to function properly after this random | |
8699 | * child dies. | |
8700 | * | |
8701 | * Do destroy all inherited groups, we don't care about those | |
8702 | * and being thorough is better. | |
8703 | */ | |
32132a3d PZ |
8704 | raw_spin_lock_irq(&child_ctx->lock); |
8705 | WARN_ON_ONCE(child_ctx->is_active); | |
8706 | ||
8ba289b8 | 8707 | if (parent_event) |
32132a3d PZ |
8708 | perf_group_detach(child_event); |
8709 | list_del_event(child_event, child_ctx); | |
c6e5b732 | 8710 | child_event->state = PERF_EVENT_STATE_EXIT; /* see perf_event_release_kernel() */ |
32132a3d | 8711 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 8712 | |
9b51f66d | 8713 | /* |
8ba289b8 | 8714 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 8715 | */ |
8ba289b8 | 8716 | if (!parent_event) { |
179033b3 | 8717 | perf_event_wakeup(child_event); |
8ba289b8 | 8718 | return; |
4bcf349a | 8719 | } |
8ba289b8 PZ |
8720 | /* |
8721 | * Child events can be cleaned up. | |
8722 | */ | |
8723 | ||
8724 | sync_child_event(child_event, child); | |
8725 | ||
8726 | /* | |
8727 | * Remove this event from the parent's list | |
8728 | */ | |
8729 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8730 | mutex_lock(&parent_event->child_mutex); | |
8731 | list_del_init(&child_event->child_list); | |
8732 | mutex_unlock(&parent_event->child_mutex); | |
8733 | ||
8734 | /* | |
8735 | * Kick perf_poll() for is_event_hup(). | |
8736 | */ | |
8737 | perf_event_wakeup(parent_event); | |
8738 | free_event(child_event); | |
8739 | put_event(parent_event); | |
9b51f66d IM |
8740 | } |
8741 | ||
8dc85d54 | 8742 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8743 | { |
211de6eb | 8744 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 8745 | struct perf_event *child_event, *next; |
63b6da39 PZ |
8746 | |
8747 | WARN_ON_ONCE(child != current); | |
9b51f66d | 8748 | |
6a3351b6 | 8749 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 8750 | if (!child_ctx) |
9b51f66d IM |
8751 | return; |
8752 | ||
6a3351b6 PZ |
8753 | /* |
8754 | * In order to reduce the amount of tricky in ctx tear-down, we hold | |
8755 | * ctx::mutex over the entire thing. This serializes against almost | |
8756 | * everything that wants to access the ctx. | |
8757 | * | |
8758 | * The exception is sys_perf_event_open() / | |
8759 | * perf_event_create_kernel_count() which does find_get_context() | |
8760 | * without ctx::mutex (it cannot because of the move_group double mutex | |
8761 | * lock thing). See the comments in perf_install_in_context(). | |
8762 | * | |
8763 | * We can recurse on the same lock type through: | |
8764 | * | |
8ba289b8 PZ |
8765 | * perf_event_exit_event() |
8766 | * put_event() | |
8767 | * mutex_lock(&ctx->mutex) | |
6a3351b6 PZ |
8768 | * |
8769 | * But since its the parent context it won't be the same instance. | |
8770 | */ | |
8771 | mutex_lock(&child_ctx->mutex); | |
8772 | ||
8773 | /* | |
8774 | * In a single ctx::lock section, de-schedule the events and detach the | |
8775 | * context from the task such that we cannot ever get it scheduled back | |
8776 | * in. | |
8777 | */ | |
8778 | raw_spin_lock_irq(&child_ctx->lock); | |
63b6da39 | 8779 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
c93f7669 PM |
8780 | |
8781 | /* | |
63b6da39 PZ |
8782 | * Now that the context is inactive, destroy the task <-> ctx relation |
8783 | * and mark the context dead. | |
c93f7669 | 8784 | */ |
63b6da39 PZ |
8785 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
8786 | put_ctx(child_ctx); /* cannot be last */ | |
8787 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
8788 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 8789 | |
211de6eb | 8790 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 8791 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8792 | |
211de6eb PZ |
8793 | if (clone_ctx) |
8794 | put_ctx(clone_ctx); | |
4a1c0f26 | 8795 | |
9f498cc5 | 8796 | /* |
cdd6c482 IM |
8797 | * Report the task dead after unscheduling the events so that we |
8798 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8799 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8800 | */ |
cdd6c482 | 8801 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8802 | |
ebf905fc | 8803 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 8804 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 8805 | |
a63eaf34 PM |
8806 | mutex_unlock(&child_ctx->mutex); |
8807 | ||
8808 | put_ctx(child_ctx); | |
9b51f66d IM |
8809 | } |
8810 | ||
8dc85d54 PZ |
8811 | /* |
8812 | * When a child task exits, feed back event values to parent events. | |
8813 | */ | |
8814 | void perf_event_exit_task(struct task_struct *child) | |
8815 | { | |
8882135b | 8816 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8817 | int ctxn; |
8818 | ||
8882135b PZ |
8819 | mutex_lock(&child->perf_event_mutex); |
8820 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8821 | owner_entry) { | |
8822 | list_del_init(&event->owner_entry); | |
8823 | ||
8824 | /* | |
8825 | * Ensure the list deletion is visible before we clear | |
8826 | * the owner, closes a race against perf_release() where | |
8827 | * we need to serialize on the owner->perf_event_mutex. | |
8828 | */ | |
f47c02c0 | 8829 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
8830 | } |
8831 | mutex_unlock(&child->perf_event_mutex); | |
8832 | ||
8dc85d54 PZ |
8833 | for_each_task_context_nr(ctxn) |
8834 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8835 | |
8836 | /* | |
8837 | * The perf_event_exit_task_context calls perf_event_task | |
8838 | * with child's task_ctx, which generates EXIT events for | |
8839 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8840 | * At this point we need to send EXIT events to cpu contexts. | |
8841 | */ | |
8842 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8843 | } |
8844 | ||
889ff015 FW |
8845 | static void perf_free_event(struct perf_event *event, |
8846 | struct perf_event_context *ctx) | |
8847 | { | |
8848 | struct perf_event *parent = event->parent; | |
8849 | ||
8850 | if (WARN_ON_ONCE(!parent)) | |
8851 | return; | |
8852 | ||
8853 | mutex_lock(&parent->child_mutex); | |
8854 | list_del_init(&event->child_list); | |
8855 | mutex_unlock(&parent->child_mutex); | |
8856 | ||
a6fa941d | 8857 | put_event(parent); |
889ff015 | 8858 | |
652884fe | 8859 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8860 | perf_group_detach(event); |
889ff015 | 8861 | list_del_event(event, ctx); |
652884fe | 8862 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8863 | free_event(event); |
8864 | } | |
8865 | ||
bbbee908 | 8866 | /* |
652884fe | 8867 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8868 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8869 | * |
8870 | * Not all locks are strictly required, but take them anyway to be nice and | |
8871 | * help out with the lockdep assertions. | |
bbbee908 | 8872 | */ |
cdd6c482 | 8873 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8874 | { |
8dc85d54 | 8875 | struct perf_event_context *ctx; |
cdd6c482 | 8876 | struct perf_event *event, *tmp; |
8dc85d54 | 8877 | int ctxn; |
bbbee908 | 8878 | |
8dc85d54 PZ |
8879 | for_each_task_context_nr(ctxn) { |
8880 | ctx = task->perf_event_ctxp[ctxn]; | |
8881 | if (!ctx) | |
8882 | continue; | |
bbbee908 | 8883 | |
8dc85d54 | 8884 | mutex_lock(&ctx->mutex); |
bbbee908 | 8885 | again: |
8dc85d54 PZ |
8886 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8887 | group_entry) | |
8888 | perf_free_event(event, ctx); | |
bbbee908 | 8889 | |
8dc85d54 PZ |
8890 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8891 | group_entry) | |
8892 | perf_free_event(event, ctx); | |
bbbee908 | 8893 | |
8dc85d54 PZ |
8894 | if (!list_empty(&ctx->pinned_groups) || |
8895 | !list_empty(&ctx->flexible_groups)) | |
8896 | goto again; | |
bbbee908 | 8897 | |
8dc85d54 | 8898 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8899 | |
8dc85d54 PZ |
8900 | put_ctx(ctx); |
8901 | } | |
889ff015 FW |
8902 | } |
8903 | ||
4e231c79 PZ |
8904 | void perf_event_delayed_put(struct task_struct *task) |
8905 | { | |
8906 | int ctxn; | |
8907 | ||
8908 | for_each_task_context_nr(ctxn) | |
8909 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8910 | } | |
8911 | ||
e03e7ee3 | 8912 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 8913 | { |
e03e7ee3 | 8914 | struct file *file; |
ffe8690c | 8915 | |
e03e7ee3 AS |
8916 | file = fget_raw(fd); |
8917 | if (!file) | |
8918 | return ERR_PTR(-EBADF); | |
ffe8690c | 8919 | |
e03e7ee3 AS |
8920 | if (file->f_op != &perf_fops) { |
8921 | fput(file); | |
8922 | return ERR_PTR(-EBADF); | |
8923 | } | |
ffe8690c | 8924 | |
e03e7ee3 | 8925 | return file; |
ffe8690c KX |
8926 | } |
8927 | ||
8928 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8929 | { | |
8930 | if (!event) | |
8931 | return ERR_PTR(-EINVAL); | |
8932 | ||
8933 | return &event->attr; | |
8934 | } | |
8935 | ||
97dee4f3 PZ |
8936 | /* |
8937 | * inherit a event from parent task to child task: | |
8938 | */ | |
8939 | static struct perf_event * | |
8940 | inherit_event(struct perf_event *parent_event, | |
8941 | struct task_struct *parent, | |
8942 | struct perf_event_context *parent_ctx, | |
8943 | struct task_struct *child, | |
8944 | struct perf_event *group_leader, | |
8945 | struct perf_event_context *child_ctx) | |
8946 | { | |
1929def9 | 8947 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8948 | struct perf_event *child_event; |
cee010ec | 8949 | unsigned long flags; |
97dee4f3 PZ |
8950 | |
8951 | /* | |
8952 | * Instead of creating recursive hierarchies of events, | |
8953 | * we link inherited events back to the original parent, | |
8954 | * which has a filp for sure, which we use as the reference | |
8955 | * count: | |
8956 | */ | |
8957 | if (parent_event->parent) | |
8958 | parent_event = parent_event->parent; | |
8959 | ||
8960 | child_event = perf_event_alloc(&parent_event->attr, | |
8961 | parent_event->cpu, | |
d580ff86 | 8962 | child, |
97dee4f3 | 8963 | group_leader, parent_event, |
79dff51e | 8964 | NULL, NULL, -1); |
97dee4f3 PZ |
8965 | if (IS_ERR(child_event)) |
8966 | return child_event; | |
a6fa941d | 8967 | |
c6e5b732 PZ |
8968 | /* |
8969 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
8970 | * must be under the same lock in order to serialize against | |
8971 | * perf_event_release_kernel(), such that either we must observe | |
8972 | * is_orphaned_event() or they will observe us on the child_list. | |
8973 | */ | |
8974 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
8975 | if (is_orphaned_event(parent_event) || |
8976 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 8977 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
8978 | free_event(child_event); |
8979 | return NULL; | |
8980 | } | |
8981 | ||
97dee4f3 PZ |
8982 | get_ctx(child_ctx); |
8983 | ||
8984 | /* | |
8985 | * Make the child state follow the state of the parent event, | |
8986 | * not its attr.disabled bit. We hold the parent's mutex, | |
8987 | * so we won't race with perf_event_{en, dis}able_family. | |
8988 | */ | |
1929def9 | 8989 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8990 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8991 | else | |
8992 | child_event->state = PERF_EVENT_STATE_OFF; | |
8993 | ||
8994 | if (parent_event->attr.freq) { | |
8995 | u64 sample_period = parent_event->hw.sample_period; | |
8996 | struct hw_perf_event *hwc = &child_event->hw; | |
8997 | ||
8998 | hwc->sample_period = sample_period; | |
8999 | hwc->last_period = sample_period; | |
9000 | ||
9001 | local64_set(&hwc->period_left, sample_period); | |
9002 | } | |
9003 | ||
9004 | child_event->ctx = child_ctx; | |
9005 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9006 | child_event->overflow_handler_context |
9007 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9008 | |
614b6780 TG |
9009 | /* |
9010 | * Precalculate sample_data sizes | |
9011 | */ | |
9012 | perf_event__header_size(child_event); | |
6844c09d | 9013 | perf_event__id_header_size(child_event); |
614b6780 | 9014 | |
97dee4f3 PZ |
9015 | /* |
9016 | * Link it up in the child's context: | |
9017 | */ | |
cee010ec | 9018 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9019 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9020 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9021 | |
97dee4f3 PZ |
9022 | /* |
9023 | * Link this into the parent event's child list | |
9024 | */ | |
97dee4f3 PZ |
9025 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9026 | mutex_unlock(&parent_event->child_mutex); | |
9027 | ||
9028 | return child_event; | |
9029 | } | |
9030 | ||
9031 | static int inherit_group(struct perf_event *parent_event, | |
9032 | struct task_struct *parent, | |
9033 | struct perf_event_context *parent_ctx, | |
9034 | struct task_struct *child, | |
9035 | struct perf_event_context *child_ctx) | |
9036 | { | |
9037 | struct perf_event *leader; | |
9038 | struct perf_event *sub; | |
9039 | struct perf_event *child_ctr; | |
9040 | ||
9041 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9042 | child, NULL, child_ctx); | |
9043 | if (IS_ERR(leader)) | |
9044 | return PTR_ERR(leader); | |
9045 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9046 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9047 | child, leader, child_ctx); | |
9048 | if (IS_ERR(child_ctr)) | |
9049 | return PTR_ERR(child_ctr); | |
9050 | } | |
9051 | return 0; | |
889ff015 FW |
9052 | } |
9053 | ||
9054 | static int | |
9055 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9056 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9057 | struct task_struct *child, int ctxn, |
889ff015 FW |
9058 | int *inherited_all) |
9059 | { | |
9060 | int ret; | |
8dc85d54 | 9061 | struct perf_event_context *child_ctx; |
889ff015 FW |
9062 | |
9063 | if (!event->attr.inherit) { | |
9064 | *inherited_all = 0; | |
9065 | return 0; | |
bbbee908 PZ |
9066 | } |
9067 | ||
fe4b04fa | 9068 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9069 | if (!child_ctx) { |
9070 | /* | |
9071 | * This is executed from the parent task context, so | |
9072 | * inherit events that have been marked for cloning. | |
9073 | * First allocate and initialize a context for the | |
9074 | * child. | |
9075 | */ | |
bbbee908 | 9076 | |
734df5ab | 9077 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9078 | if (!child_ctx) |
9079 | return -ENOMEM; | |
bbbee908 | 9080 | |
8dc85d54 | 9081 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9082 | } |
9083 | ||
9084 | ret = inherit_group(event, parent, parent_ctx, | |
9085 | child, child_ctx); | |
9086 | ||
9087 | if (ret) | |
9088 | *inherited_all = 0; | |
9089 | ||
9090 | return ret; | |
bbbee908 PZ |
9091 | } |
9092 | ||
9b51f66d | 9093 | /* |
cdd6c482 | 9094 | * Initialize the perf_event context in task_struct |
9b51f66d | 9095 | */ |
985c8dcb | 9096 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9097 | { |
889ff015 | 9098 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9099 | struct perf_event_context *cloned_ctx; |
9100 | struct perf_event *event; | |
9b51f66d | 9101 | struct task_struct *parent = current; |
564c2b21 | 9102 | int inherited_all = 1; |
dddd3379 | 9103 | unsigned long flags; |
6ab423e0 | 9104 | int ret = 0; |
9b51f66d | 9105 | |
8dc85d54 | 9106 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9107 | return 0; |
9108 | ||
ad3a37de | 9109 | /* |
25346b93 PM |
9110 | * If the parent's context is a clone, pin it so it won't get |
9111 | * swapped under us. | |
ad3a37de | 9112 | */ |
8dc85d54 | 9113 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9114 | if (!parent_ctx) |
9115 | return 0; | |
25346b93 | 9116 | |
ad3a37de PM |
9117 | /* |
9118 | * No need to check if parent_ctx != NULL here; since we saw | |
9119 | * it non-NULL earlier, the only reason for it to become NULL | |
9120 | * is if we exit, and since we're currently in the middle of | |
9121 | * a fork we can't be exiting at the same time. | |
9122 | */ | |
ad3a37de | 9123 | |
9b51f66d IM |
9124 | /* |
9125 | * Lock the parent list. No need to lock the child - not PID | |
9126 | * hashed yet and not running, so nobody can access it. | |
9127 | */ | |
d859e29f | 9128 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9129 | |
9130 | /* | |
9131 | * We dont have to disable NMIs - we are only looking at | |
9132 | * the list, not manipulating it: | |
9133 | */ | |
889ff015 | 9134 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9135 | ret = inherit_task_group(event, parent, parent_ctx, |
9136 | child, ctxn, &inherited_all); | |
889ff015 FW |
9137 | if (ret) |
9138 | break; | |
9139 | } | |
b93f7978 | 9140 | |
dddd3379 TG |
9141 | /* |
9142 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9143 | * to allocations, but we need to prevent rotation because | |
9144 | * rotate_ctx() will change the list from interrupt context. | |
9145 | */ | |
9146 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9147 | parent_ctx->rotate_disable = 1; | |
9148 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9149 | ||
889ff015 | 9150 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9151 | ret = inherit_task_group(event, parent, parent_ctx, |
9152 | child, ctxn, &inherited_all); | |
889ff015 | 9153 | if (ret) |
9b51f66d | 9154 | break; |
564c2b21 PM |
9155 | } |
9156 | ||
dddd3379 TG |
9157 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9158 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9159 | |
8dc85d54 | 9160 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9161 | |
05cbaa28 | 9162 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9163 | /* |
9164 | * Mark the child context as a clone of the parent | |
9165 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9166 | * |
9167 | * Note that if the parent is a clone, the holding of | |
9168 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9169 | */ |
c5ed5145 | 9170 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9171 | if (cloned_ctx) { |
9172 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9173 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9174 | } else { |
9175 | child_ctx->parent_ctx = parent_ctx; | |
9176 | child_ctx->parent_gen = parent_ctx->generation; | |
9177 | } | |
9178 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9179 | } |
9180 | ||
c5ed5145 | 9181 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9182 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9183 | |
25346b93 | 9184 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9185 | put_ctx(parent_ctx); |
ad3a37de | 9186 | |
6ab423e0 | 9187 | return ret; |
9b51f66d IM |
9188 | } |
9189 | ||
8dc85d54 PZ |
9190 | /* |
9191 | * Initialize the perf_event context in task_struct | |
9192 | */ | |
9193 | int perf_event_init_task(struct task_struct *child) | |
9194 | { | |
9195 | int ctxn, ret; | |
9196 | ||
8550d7cb ON |
9197 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9198 | mutex_init(&child->perf_event_mutex); | |
9199 | INIT_LIST_HEAD(&child->perf_event_list); | |
9200 | ||
8dc85d54 PZ |
9201 | for_each_task_context_nr(ctxn) { |
9202 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9203 | if (ret) { |
9204 | perf_event_free_task(child); | |
8dc85d54 | 9205 | return ret; |
6c72e350 | 9206 | } |
8dc85d54 PZ |
9207 | } |
9208 | ||
9209 | return 0; | |
9210 | } | |
9211 | ||
220b140b PM |
9212 | static void __init perf_event_init_all_cpus(void) |
9213 | { | |
b28ab83c | 9214 | struct swevent_htable *swhash; |
220b140b | 9215 | int cpu; |
220b140b PM |
9216 | |
9217 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9218 | swhash = &per_cpu(swevent_htable, cpu); |
9219 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9220 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9221 | } |
9222 | } | |
9223 | ||
0db0628d | 9224 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9225 | { |
108b02cf | 9226 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9227 | |
b28ab83c | 9228 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9229 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9230 | struct swevent_hlist *hlist; |
9231 | ||
b28ab83c PZ |
9232 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9233 | WARN_ON(!hlist); | |
9234 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9235 | } |
b28ab83c | 9236 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9237 | } |
9238 | ||
2965faa5 | 9239 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9240 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9241 | { |
108b02cf | 9242 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9243 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9244 | struct perf_event *event; | |
0793a61d | 9245 | |
fae3fde6 PZ |
9246 | raw_spin_lock(&ctx->lock); |
9247 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9248 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9249 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9250 | } |
108b02cf PZ |
9251 | |
9252 | static void perf_event_exit_cpu_context(int cpu) | |
9253 | { | |
9254 | struct perf_event_context *ctx; | |
9255 | struct pmu *pmu; | |
9256 | int idx; | |
9257 | ||
9258 | idx = srcu_read_lock(&pmus_srcu); | |
9259 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9260 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9261 | |
9262 | mutex_lock(&ctx->mutex); | |
9263 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9264 | mutex_unlock(&ctx->mutex); | |
9265 | } | |
9266 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9267 | } |
9268 | ||
cdd6c482 | 9269 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9270 | { |
e3703f8c | 9271 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9272 | } |
9273 | #else | |
cdd6c482 | 9274 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9275 | #endif |
9276 | ||
c277443c PZ |
9277 | static int |
9278 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9279 | { | |
9280 | int cpu; | |
9281 | ||
9282 | for_each_online_cpu(cpu) | |
9283 | perf_event_exit_cpu(cpu); | |
9284 | ||
9285 | return NOTIFY_OK; | |
9286 | } | |
9287 | ||
9288 | /* | |
9289 | * Run the perf reboot notifier at the very last possible moment so that | |
9290 | * the generic watchdog code runs as long as possible. | |
9291 | */ | |
9292 | static struct notifier_block perf_reboot_notifier = { | |
9293 | .notifier_call = perf_reboot, | |
9294 | .priority = INT_MIN, | |
9295 | }; | |
9296 | ||
0db0628d | 9297 | static int |
0793a61d TG |
9298 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9299 | { | |
9300 | unsigned int cpu = (long)hcpu; | |
9301 | ||
4536e4d1 | 9302 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9303 | |
9304 | case CPU_UP_PREPARE: | |
5e11637e | 9305 | case CPU_DOWN_FAILED: |
cdd6c482 | 9306 | perf_event_init_cpu(cpu); |
0793a61d TG |
9307 | break; |
9308 | ||
5e11637e | 9309 | case CPU_UP_CANCELED: |
0793a61d | 9310 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9311 | perf_event_exit_cpu(cpu); |
0793a61d | 9312 | break; |
0793a61d TG |
9313 | default: |
9314 | break; | |
9315 | } | |
9316 | ||
9317 | return NOTIFY_OK; | |
9318 | } | |
9319 | ||
cdd6c482 | 9320 | void __init perf_event_init(void) |
0793a61d | 9321 | { |
3c502e7a JW |
9322 | int ret; |
9323 | ||
2e80a82a PZ |
9324 | idr_init(&pmu_idr); |
9325 | ||
220b140b | 9326 | perf_event_init_all_cpus(); |
b0a873eb | 9327 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9328 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9329 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9330 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9331 | perf_tp_register(); |
9332 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9333 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9334 | |
9335 | ret = init_hw_breakpoint(); | |
9336 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9337 | |
9338 | /* do not patch jump label more than once per second */ | |
9339 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9340 | |
9341 | /* | |
9342 | * Build time assertion that we keep the data_head at the intended | |
9343 | * location. IOW, validation we got the __reserved[] size right. | |
9344 | */ | |
9345 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9346 | != 1024); | |
0793a61d | 9347 | } |
abe43400 | 9348 | |
fd979c01 CS |
9349 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9350 | char *page) | |
9351 | { | |
9352 | struct perf_pmu_events_attr *pmu_attr = | |
9353 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9354 | ||
9355 | if (pmu_attr->event_str) | |
9356 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9357 | ||
9358 | return 0; | |
9359 | } | |
9360 | ||
abe43400 PZ |
9361 | static int __init perf_event_sysfs_init(void) |
9362 | { | |
9363 | struct pmu *pmu; | |
9364 | int ret; | |
9365 | ||
9366 | mutex_lock(&pmus_lock); | |
9367 | ||
9368 | ret = bus_register(&pmu_bus); | |
9369 | if (ret) | |
9370 | goto unlock; | |
9371 | ||
9372 | list_for_each_entry(pmu, &pmus, entry) { | |
9373 | if (!pmu->name || pmu->type < 0) | |
9374 | continue; | |
9375 | ||
9376 | ret = pmu_dev_alloc(pmu); | |
9377 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9378 | } | |
9379 | pmu_bus_running = 1; | |
9380 | ret = 0; | |
9381 | ||
9382 | unlock: | |
9383 | mutex_unlock(&pmus_lock); | |
9384 | ||
9385 | return ret; | |
9386 | } | |
9387 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9388 | |
9389 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9390 | static struct cgroup_subsys_state * |
9391 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9392 | { |
9393 | struct perf_cgroup *jc; | |
e5d1367f | 9394 | |
1b15d055 | 9395 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9396 | if (!jc) |
9397 | return ERR_PTR(-ENOMEM); | |
9398 | ||
e5d1367f SE |
9399 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9400 | if (!jc->info) { | |
9401 | kfree(jc); | |
9402 | return ERR_PTR(-ENOMEM); | |
9403 | } | |
9404 | ||
e5d1367f SE |
9405 | return &jc->css; |
9406 | } | |
9407 | ||
eb95419b | 9408 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9409 | { |
eb95419b TH |
9410 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9411 | ||
e5d1367f SE |
9412 | free_percpu(jc->info); |
9413 | kfree(jc); | |
9414 | } | |
9415 | ||
9416 | static int __perf_cgroup_move(void *info) | |
9417 | { | |
9418 | struct task_struct *task = info; | |
ddaaf4e2 | 9419 | rcu_read_lock(); |
e5d1367f | 9420 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9421 | rcu_read_unlock(); |
e5d1367f SE |
9422 | return 0; |
9423 | } | |
9424 | ||
1f7dd3e5 | 9425 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9426 | { |
bb9d97b6 | 9427 | struct task_struct *task; |
1f7dd3e5 | 9428 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9429 | |
1f7dd3e5 | 9430 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9431 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9432 | } |
9433 | ||
073219e9 | 9434 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9435 | .css_alloc = perf_cgroup_css_alloc, |
9436 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9437 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9438 | }; |
9439 | #endif /* CONFIG_CGROUP_PERF */ |