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Commit | Line | Data |
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0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
272325c4 PZ |
52 | typedef int (*remote_function_f)(void *); |
53 | ||
fe4b04fa | 54 | struct remote_function_call { |
e7e7ee2e | 55 | struct task_struct *p; |
272325c4 | 56 | remote_function_f func; |
e7e7ee2e IM |
57 | void *info; |
58 | int ret; | |
fe4b04fa PZ |
59 | }; |
60 | ||
61 | static void remote_function(void *data) | |
62 | { | |
63 | struct remote_function_call *tfc = data; | |
64 | struct task_struct *p = tfc->p; | |
65 | ||
66 | if (p) { | |
67 | tfc->ret = -EAGAIN; | |
68 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
69 | return; | |
70 | } | |
71 | ||
72 | tfc->ret = tfc->func(tfc->info); | |
73 | } | |
74 | ||
75 | /** | |
76 | * task_function_call - call a function on the cpu on which a task runs | |
77 | * @p: the task to evaluate | |
78 | * @func: the function to be called | |
79 | * @info: the function call argument | |
80 | * | |
81 | * Calls the function @func when the task is currently running. This might | |
82 | * be on the current CPU, which just calls the function directly | |
83 | * | |
84 | * returns: @func return value, or | |
85 | * -ESRCH - when the process isn't running | |
86 | * -EAGAIN - when the process moved away | |
87 | */ | |
88 | static int | |
272325c4 | 89 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
90 | { |
91 | struct remote_function_call data = { | |
e7e7ee2e IM |
92 | .p = p, |
93 | .func = func, | |
94 | .info = info, | |
95 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
96 | }; |
97 | ||
98 | if (task_curr(p)) | |
99 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
100 | ||
101 | return data.ret; | |
102 | } | |
103 | ||
104 | /** | |
105 | * cpu_function_call - call a function on the cpu | |
106 | * @func: the function to be called | |
107 | * @info: the function call argument | |
108 | * | |
109 | * Calls the function @func on the remote cpu. | |
110 | * | |
111 | * returns: @func return value or -ENXIO when the cpu is offline | |
112 | */ | |
272325c4 | 113 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
114 | { |
115 | struct remote_function_call data = { | |
e7e7ee2e IM |
116 | .p = NULL, |
117 | .func = func, | |
118 | .info = info, | |
119 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
120 | }; |
121 | ||
122 | smp_call_function_single(cpu, remote_function, &data, 1); | |
123 | ||
124 | return data.ret; | |
125 | } | |
126 | ||
fae3fde6 PZ |
127 | static inline struct perf_cpu_context * |
128 | __get_cpu_context(struct perf_event_context *ctx) | |
129 | { | |
130 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
131 | } | |
132 | ||
133 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
134 | struct perf_event_context *ctx) | |
0017960f | 135 | { |
fae3fde6 PZ |
136 | raw_spin_lock(&cpuctx->ctx.lock); |
137 | if (ctx) | |
138 | raw_spin_lock(&ctx->lock); | |
139 | } | |
140 | ||
141 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
142 | struct perf_event_context *ctx) | |
143 | { | |
144 | if (ctx) | |
145 | raw_spin_unlock(&ctx->lock); | |
146 | raw_spin_unlock(&cpuctx->ctx.lock); | |
147 | } | |
148 | ||
63b6da39 PZ |
149 | #define TASK_TOMBSTONE ((void *)-1L) |
150 | ||
151 | static bool is_kernel_event(struct perf_event *event) | |
152 | { | |
f47c02c0 | 153 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
154 | } |
155 | ||
39a43640 PZ |
156 | /* |
157 | * On task ctx scheduling... | |
158 | * | |
159 | * When !ctx->nr_events a task context will not be scheduled. This means | |
160 | * we can disable the scheduler hooks (for performance) without leaving | |
161 | * pending task ctx state. | |
162 | * | |
163 | * This however results in two special cases: | |
164 | * | |
165 | * - removing the last event from a task ctx; this is relatively straight | |
166 | * forward and is done in __perf_remove_from_context. | |
167 | * | |
168 | * - adding the first event to a task ctx; this is tricky because we cannot | |
169 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
170 | * See perf_install_in_context(). | |
171 | * | |
172 | * This is because we need a ctx->lock serialized variable (ctx->is_active) | |
173 | * to reliably determine if a particular task/context is scheduled in. The | |
174 | * task_curr() use in task_function_call() is racy in that a remote context | |
175 | * switch is not a single atomic operation. | |
176 | * | |
177 | * As is, the situation is 'safe' because we set rq->curr before we do the | |
178 | * actual context switch. This means that task_curr() will fail early, but | |
179 | * we'll continue spinning on ctx->is_active until we've passed | |
180 | * perf_event_task_sched_out(). | |
181 | * | |
182 | * Without this ctx->lock serialized variable we could have race where we find | |
183 | * the task (and hence the context) would not be active while in fact they are. | |
184 | * | |
185 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. | |
186 | */ | |
187 | ||
fae3fde6 PZ |
188 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
189 | struct perf_event_context *, void *); | |
190 | ||
191 | struct event_function_struct { | |
192 | struct perf_event *event; | |
193 | event_f func; | |
194 | void *data; | |
195 | }; | |
196 | ||
197 | static int event_function(void *info) | |
198 | { | |
199 | struct event_function_struct *efs = info; | |
200 | struct perf_event *event = efs->event; | |
0017960f | 201 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
202 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
203 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 204 | int ret = 0; |
fae3fde6 PZ |
205 | |
206 | WARN_ON_ONCE(!irqs_disabled()); | |
207 | ||
63b6da39 | 208 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
209 | /* |
210 | * Since we do the IPI call without holding ctx->lock things can have | |
211 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
212 | */ |
213 | if (ctx->task) { | |
63b6da39 PZ |
214 | if (ctx->task != current) { |
215 | ret = -EAGAIN; | |
216 | goto unlock; | |
217 | } | |
fae3fde6 | 218 | |
fae3fde6 PZ |
219 | /* |
220 | * We only use event_function_call() on established contexts, | |
221 | * and event_function() is only ever called when active (or | |
222 | * rather, we'll have bailed in task_function_call() or the | |
223 | * above ctx->task != current test), therefore we must have | |
224 | * ctx->is_active here. | |
225 | */ | |
226 | WARN_ON_ONCE(!ctx->is_active); | |
227 | /* | |
228 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
229 | * match. | |
230 | */ | |
63b6da39 PZ |
231 | WARN_ON_ONCE(task_ctx != ctx); |
232 | } else { | |
233 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 234 | } |
63b6da39 | 235 | |
fae3fde6 | 236 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 237 | unlock: |
fae3fde6 PZ |
238 | perf_ctx_unlock(cpuctx, task_ctx); |
239 | ||
63b6da39 | 240 | return ret; |
fae3fde6 PZ |
241 | } |
242 | ||
243 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
244 | { | |
245 | struct event_function_struct efs = { | |
246 | .event = event, | |
247 | .func = func, | |
248 | .data = data, | |
249 | }; | |
250 | ||
251 | int ret = event_function(&efs); | |
252 | WARN_ON_ONCE(ret); | |
253 | } | |
254 | ||
255 | static void event_function_call(struct perf_event *event, event_f func, void *data) | |
0017960f PZ |
256 | { |
257 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 258 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
259 | struct event_function_struct efs = { |
260 | .event = event, | |
261 | .func = func, | |
262 | .data = data, | |
263 | }; | |
0017960f | 264 | |
c97f4736 PZ |
265 | if (!event->parent) { |
266 | /* | |
267 | * If this is a !child event, we must hold ctx::mutex to | |
268 | * stabilize the the event->ctx relation. See | |
269 | * perf_event_ctx_lock(). | |
270 | */ | |
271 | lockdep_assert_held(&ctx->mutex); | |
272 | } | |
0017960f PZ |
273 | |
274 | if (!task) { | |
fae3fde6 | 275 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
276 | return; |
277 | } | |
278 | ||
279 | again: | |
63b6da39 PZ |
280 | if (task == TASK_TOMBSTONE) |
281 | return; | |
282 | ||
fae3fde6 | 283 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
284 | return; |
285 | ||
286 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
287 | /* |
288 | * Reload the task pointer, it might have been changed by | |
289 | * a concurrent perf_event_context_sched_out(). | |
290 | */ | |
291 | task = ctx->task; | |
292 | if (task != TASK_TOMBSTONE) { | |
293 | if (ctx->is_active) { | |
294 | raw_spin_unlock_irq(&ctx->lock); | |
295 | goto again; | |
296 | } | |
297 | func(event, NULL, ctx, data); | |
0017960f | 298 | } |
0017960f PZ |
299 | raw_spin_unlock_irq(&ctx->lock); |
300 | } | |
301 | ||
e5d1367f SE |
302 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
303 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
304 | PERF_FLAG_PID_CGROUP |\ |
305 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 306 | |
bce38cd5 SE |
307 | /* |
308 | * branch priv levels that need permission checks | |
309 | */ | |
310 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
311 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
312 | PERF_SAMPLE_BRANCH_HV) | |
313 | ||
0b3fcf17 SE |
314 | enum event_type_t { |
315 | EVENT_FLEXIBLE = 0x1, | |
316 | EVENT_PINNED = 0x2, | |
317 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
318 | }; | |
319 | ||
e5d1367f SE |
320 | /* |
321 | * perf_sched_events : >0 events exist | |
322 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
323 | */ | |
c5905afb | 324 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 325 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 326 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 327 | |
cdd6c482 IM |
328 | static atomic_t nr_mmap_events __read_mostly; |
329 | static atomic_t nr_comm_events __read_mostly; | |
330 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 331 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 332 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 333 | |
108b02cf PZ |
334 | static LIST_HEAD(pmus); |
335 | static DEFINE_MUTEX(pmus_lock); | |
336 | static struct srcu_struct pmus_srcu; | |
337 | ||
0764771d | 338 | /* |
cdd6c482 | 339 | * perf event paranoia level: |
0fbdea19 IM |
340 | * -1 - not paranoid at all |
341 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 342 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 343 | * 2 - disallow kernel profiling for unpriv |
0764771d | 344 | */ |
cdd6c482 | 345 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 346 | |
20443384 FW |
347 | /* Minimum for 512 kiB + 1 user control page */ |
348 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
349 | |
350 | /* | |
cdd6c482 | 351 | * max perf event sample rate |
df58ab24 | 352 | */ |
14c63f17 DH |
353 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
354 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
355 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
356 | ||
357 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
358 | ||
359 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
360 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
361 | ||
d9494cb4 PZ |
362 | static int perf_sample_allowed_ns __read_mostly = |
363 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 364 | |
18ab2cd3 | 365 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
366 | { |
367 | u64 tmp = perf_sample_period_ns; | |
368 | ||
369 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 370 | do_div(tmp, 100); |
d9494cb4 | 371 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 372 | } |
163ec435 | 373 | |
9e630205 SE |
374 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
375 | ||
163ec435 PZ |
376 | int perf_proc_update_handler(struct ctl_table *table, int write, |
377 | void __user *buffer, size_t *lenp, | |
378 | loff_t *ppos) | |
379 | { | |
723478c8 | 380 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
381 | |
382 | if (ret || !write) | |
383 | return ret; | |
384 | ||
385 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
386 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
387 | update_perf_cpu_limits(); | |
388 | ||
389 | return 0; | |
390 | } | |
391 | ||
392 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
393 | ||
394 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
395 | void __user *buffer, size_t *lenp, | |
396 | loff_t *ppos) | |
397 | { | |
398 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
399 | ||
400 | if (ret || !write) | |
401 | return ret; | |
402 | ||
403 | update_perf_cpu_limits(); | |
163ec435 PZ |
404 | |
405 | return 0; | |
406 | } | |
1ccd1549 | 407 | |
14c63f17 DH |
408 | /* |
409 | * perf samples are done in some very critical code paths (NMIs). | |
410 | * If they take too much CPU time, the system can lock up and not | |
411 | * get any real work done. This will drop the sample rate when | |
412 | * we detect that events are taking too long. | |
413 | */ | |
414 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 415 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 416 | |
6a02ad66 | 417 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 418 | { |
6a02ad66 | 419 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 420 | u64 avg_local_sample_len; |
e5302920 | 421 | u64 local_samples_len; |
6a02ad66 | 422 | |
4a32fea9 | 423 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
424 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
425 | ||
426 | printk_ratelimited(KERN_WARNING | |
427 | "perf interrupt took too long (%lld > %lld), lowering " | |
428 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 429 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
430 | sysctl_perf_event_sample_rate); |
431 | } | |
432 | ||
433 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
434 | ||
435 | void perf_sample_event_took(u64 sample_len_ns) | |
436 | { | |
d9494cb4 | 437 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
438 | u64 avg_local_sample_len; |
439 | u64 local_samples_len; | |
14c63f17 | 440 | |
d9494cb4 | 441 | if (allowed_ns == 0) |
14c63f17 DH |
442 | return; |
443 | ||
444 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 445 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
446 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
447 | local_samples_len += sample_len_ns; | |
4a32fea9 | 448 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
449 | |
450 | /* | |
451 | * note: this will be biased artifically low until we have | |
452 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
453 | * from having to maintain a count. | |
454 | */ | |
455 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
456 | ||
d9494cb4 | 457 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
458 | return; |
459 | ||
460 | if (max_samples_per_tick <= 1) | |
461 | return; | |
462 | ||
463 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
464 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
465 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
466 | ||
14c63f17 | 467 | update_perf_cpu_limits(); |
6a02ad66 | 468 | |
cd578abb PZ |
469 | if (!irq_work_queue(&perf_duration_work)) { |
470 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
471 | "kernel.perf_event_max_sample_rate to %d\n", | |
472 | avg_local_sample_len, allowed_ns >> 1, | |
473 | sysctl_perf_event_sample_rate); | |
474 | } | |
14c63f17 DH |
475 | } |
476 | ||
cdd6c482 | 477 | static atomic64_t perf_event_id; |
a96bbc16 | 478 | |
0b3fcf17 SE |
479 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
480 | enum event_type_t event_type); | |
481 | ||
482 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
483 | enum event_type_t event_type, |
484 | struct task_struct *task); | |
485 | ||
486 | static void update_context_time(struct perf_event_context *ctx); | |
487 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 488 | |
cdd6c482 | 489 | void __weak perf_event_print_debug(void) { } |
0793a61d | 490 | |
84c79910 | 491 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 492 | { |
84c79910 | 493 | return "pmu"; |
0793a61d TG |
494 | } |
495 | ||
0b3fcf17 SE |
496 | static inline u64 perf_clock(void) |
497 | { | |
498 | return local_clock(); | |
499 | } | |
500 | ||
34f43927 PZ |
501 | static inline u64 perf_event_clock(struct perf_event *event) |
502 | { | |
503 | return event->clock(); | |
504 | } | |
505 | ||
e5d1367f SE |
506 | #ifdef CONFIG_CGROUP_PERF |
507 | ||
e5d1367f SE |
508 | static inline bool |
509 | perf_cgroup_match(struct perf_event *event) | |
510 | { | |
511 | struct perf_event_context *ctx = event->ctx; | |
512 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
513 | ||
ef824fa1 TH |
514 | /* @event doesn't care about cgroup */ |
515 | if (!event->cgrp) | |
516 | return true; | |
517 | ||
518 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
519 | if (!cpuctx->cgrp) | |
520 | return false; | |
521 | ||
522 | /* | |
523 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
524 | * also enabled for all its descendant cgroups. If @cpuctx's | |
525 | * cgroup is a descendant of @event's (the test covers identity | |
526 | * case), it's a match. | |
527 | */ | |
528 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
529 | event->cgrp->css.cgroup); | |
e5d1367f SE |
530 | } |
531 | ||
e5d1367f SE |
532 | static inline void perf_detach_cgroup(struct perf_event *event) |
533 | { | |
4e2ba650 | 534 | css_put(&event->cgrp->css); |
e5d1367f SE |
535 | event->cgrp = NULL; |
536 | } | |
537 | ||
538 | static inline int is_cgroup_event(struct perf_event *event) | |
539 | { | |
540 | return event->cgrp != NULL; | |
541 | } | |
542 | ||
543 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
544 | { | |
545 | struct perf_cgroup_info *t; | |
546 | ||
547 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
548 | return t->time; | |
549 | } | |
550 | ||
551 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
552 | { | |
553 | struct perf_cgroup_info *info; | |
554 | u64 now; | |
555 | ||
556 | now = perf_clock(); | |
557 | ||
558 | info = this_cpu_ptr(cgrp->info); | |
559 | ||
560 | info->time += now - info->timestamp; | |
561 | info->timestamp = now; | |
562 | } | |
563 | ||
564 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
565 | { | |
566 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
567 | if (cgrp_out) | |
568 | __update_cgrp_time(cgrp_out); | |
569 | } | |
570 | ||
571 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
572 | { | |
3f7cce3c SE |
573 | struct perf_cgroup *cgrp; |
574 | ||
e5d1367f | 575 | /* |
3f7cce3c SE |
576 | * ensure we access cgroup data only when needed and |
577 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 578 | */ |
3f7cce3c | 579 | if (!is_cgroup_event(event)) |
e5d1367f SE |
580 | return; |
581 | ||
614e4c4e | 582 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
583 | /* |
584 | * Do not update time when cgroup is not active | |
585 | */ | |
586 | if (cgrp == event->cgrp) | |
587 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
588 | } |
589 | ||
590 | static inline void | |
3f7cce3c SE |
591 | perf_cgroup_set_timestamp(struct task_struct *task, |
592 | struct perf_event_context *ctx) | |
e5d1367f SE |
593 | { |
594 | struct perf_cgroup *cgrp; | |
595 | struct perf_cgroup_info *info; | |
596 | ||
3f7cce3c SE |
597 | /* |
598 | * ctx->lock held by caller | |
599 | * ensure we do not access cgroup data | |
600 | * unless we have the cgroup pinned (css_get) | |
601 | */ | |
602 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
603 | return; |
604 | ||
614e4c4e | 605 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 606 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 607 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
608 | } |
609 | ||
610 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
611 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
612 | ||
613 | /* | |
614 | * reschedule events based on the cgroup constraint of task. | |
615 | * | |
616 | * mode SWOUT : schedule out everything | |
617 | * mode SWIN : schedule in based on cgroup for next | |
618 | */ | |
18ab2cd3 | 619 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
620 | { |
621 | struct perf_cpu_context *cpuctx; | |
622 | struct pmu *pmu; | |
623 | unsigned long flags; | |
624 | ||
625 | /* | |
626 | * disable interrupts to avoid geting nr_cgroup | |
627 | * changes via __perf_event_disable(). Also | |
628 | * avoids preemption. | |
629 | */ | |
630 | local_irq_save(flags); | |
631 | ||
632 | /* | |
633 | * we reschedule only in the presence of cgroup | |
634 | * constrained events. | |
635 | */ | |
e5d1367f SE |
636 | |
637 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 638 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
639 | if (cpuctx->unique_pmu != pmu) |
640 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 641 | |
e5d1367f SE |
642 | /* |
643 | * perf_cgroup_events says at least one | |
644 | * context on this CPU has cgroup events. | |
645 | * | |
646 | * ctx->nr_cgroups reports the number of cgroup | |
647 | * events for a context. | |
648 | */ | |
649 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
650 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
651 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
652 | |
653 | if (mode & PERF_CGROUP_SWOUT) { | |
654 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
655 | /* | |
656 | * must not be done before ctxswout due | |
657 | * to event_filter_match() in event_sched_out() | |
658 | */ | |
659 | cpuctx->cgrp = NULL; | |
660 | } | |
661 | ||
662 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 663 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
664 | /* |
665 | * set cgrp before ctxsw in to allow | |
666 | * event_filter_match() to not have to pass | |
667 | * task around | |
614e4c4e SE |
668 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
669 | * because cgorup events are only per-cpu | |
e5d1367f | 670 | */ |
614e4c4e | 671 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
672 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
673 | } | |
facc4307 PZ |
674 | perf_pmu_enable(cpuctx->ctx.pmu); |
675 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 676 | } |
e5d1367f SE |
677 | } |
678 | ||
e5d1367f SE |
679 | local_irq_restore(flags); |
680 | } | |
681 | ||
a8d757ef SE |
682 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
683 | struct task_struct *next) | |
e5d1367f | 684 | { |
a8d757ef SE |
685 | struct perf_cgroup *cgrp1; |
686 | struct perf_cgroup *cgrp2 = NULL; | |
687 | ||
ddaaf4e2 | 688 | rcu_read_lock(); |
a8d757ef SE |
689 | /* |
690 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
691 | * we do not need to pass the ctx here because we know |
692 | * we are holding the rcu lock | |
a8d757ef | 693 | */ |
614e4c4e | 694 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 695 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
696 | |
697 | /* | |
698 | * only schedule out current cgroup events if we know | |
699 | * that we are switching to a different cgroup. Otherwise, | |
700 | * do no touch the cgroup events. | |
701 | */ | |
702 | if (cgrp1 != cgrp2) | |
703 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
704 | |
705 | rcu_read_unlock(); | |
e5d1367f SE |
706 | } |
707 | ||
a8d757ef SE |
708 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
709 | struct task_struct *task) | |
e5d1367f | 710 | { |
a8d757ef SE |
711 | struct perf_cgroup *cgrp1; |
712 | struct perf_cgroup *cgrp2 = NULL; | |
713 | ||
ddaaf4e2 | 714 | rcu_read_lock(); |
a8d757ef SE |
715 | /* |
716 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
717 | * we do not need to pass the ctx here because we know |
718 | * we are holding the rcu lock | |
a8d757ef | 719 | */ |
614e4c4e | 720 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 721 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
722 | |
723 | /* | |
724 | * only need to schedule in cgroup events if we are changing | |
725 | * cgroup during ctxsw. Cgroup events were not scheduled | |
726 | * out of ctxsw out if that was not the case. | |
727 | */ | |
728 | if (cgrp1 != cgrp2) | |
729 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
730 | |
731 | rcu_read_unlock(); | |
e5d1367f SE |
732 | } |
733 | ||
734 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
735 | struct perf_event_attr *attr, | |
736 | struct perf_event *group_leader) | |
737 | { | |
738 | struct perf_cgroup *cgrp; | |
739 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
740 | struct fd f = fdget(fd); |
741 | int ret = 0; | |
e5d1367f | 742 | |
2903ff01 | 743 | if (!f.file) |
e5d1367f SE |
744 | return -EBADF; |
745 | ||
b583043e | 746 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 747 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
748 | if (IS_ERR(css)) { |
749 | ret = PTR_ERR(css); | |
750 | goto out; | |
751 | } | |
e5d1367f SE |
752 | |
753 | cgrp = container_of(css, struct perf_cgroup, css); | |
754 | event->cgrp = cgrp; | |
755 | ||
756 | /* | |
757 | * all events in a group must monitor | |
758 | * the same cgroup because a task belongs | |
759 | * to only one perf cgroup at a time | |
760 | */ | |
761 | if (group_leader && group_leader->cgrp != cgrp) { | |
762 | perf_detach_cgroup(event); | |
763 | ret = -EINVAL; | |
e5d1367f | 764 | } |
3db272c0 | 765 | out: |
2903ff01 | 766 | fdput(f); |
e5d1367f SE |
767 | return ret; |
768 | } | |
769 | ||
770 | static inline void | |
771 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
772 | { | |
773 | struct perf_cgroup_info *t; | |
774 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
775 | event->shadow_ctx_time = now - t->timestamp; | |
776 | } | |
777 | ||
778 | static inline void | |
779 | perf_cgroup_defer_enabled(struct perf_event *event) | |
780 | { | |
781 | /* | |
782 | * when the current task's perf cgroup does not match | |
783 | * the event's, we need to remember to call the | |
784 | * perf_mark_enable() function the first time a task with | |
785 | * a matching perf cgroup is scheduled in. | |
786 | */ | |
787 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
788 | event->cgrp_defer_enabled = 1; | |
789 | } | |
790 | ||
791 | static inline void | |
792 | perf_cgroup_mark_enabled(struct perf_event *event, | |
793 | struct perf_event_context *ctx) | |
794 | { | |
795 | struct perf_event *sub; | |
796 | u64 tstamp = perf_event_time(event); | |
797 | ||
798 | if (!event->cgrp_defer_enabled) | |
799 | return; | |
800 | ||
801 | event->cgrp_defer_enabled = 0; | |
802 | ||
803 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
804 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
805 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
806 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
807 | sub->cgrp_defer_enabled = 0; | |
808 | } | |
809 | } | |
810 | } | |
811 | #else /* !CONFIG_CGROUP_PERF */ | |
812 | ||
813 | static inline bool | |
814 | perf_cgroup_match(struct perf_event *event) | |
815 | { | |
816 | return true; | |
817 | } | |
818 | ||
819 | static inline void perf_detach_cgroup(struct perf_event *event) | |
820 | {} | |
821 | ||
822 | static inline int is_cgroup_event(struct perf_event *event) | |
823 | { | |
824 | return 0; | |
825 | } | |
826 | ||
827 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
828 | { | |
829 | return 0; | |
830 | } | |
831 | ||
832 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
833 | { | |
834 | } | |
835 | ||
836 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
837 | { | |
838 | } | |
839 | ||
a8d757ef SE |
840 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
841 | struct task_struct *next) | |
e5d1367f SE |
842 | { |
843 | } | |
844 | ||
a8d757ef SE |
845 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
846 | struct task_struct *task) | |
e5d1367f SE |
847 | { |
848 | } | |
849 | ||
850 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
851 | struct perf_event_attr *attr, | |
852 | struct perf_event *group_leader) | |
853 | { | |
854 | return -EINVAL; | |
855 | } | |
856 | ||
857 | static inline void | |
3f7cce3c SE |
858 | perf_cgroup_set_timestamp(struct task_struct *task, |
859 | struct perf_event_context *ctx) | |
e5d1367f SE |
860 | { |
861 | } | |
862 | ||
863 | void | |
864 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
865 | { | |
866 | } | |
867 | ||
868 | static inline void | |
869 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
870 | { | |
871 | } | |
872 | ||
873 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
874 | { | |
875 | return 0; | |
876 | } | |
877 | ||
878 | static inline void | |
879 | perf_cgroup_defer_enabled(struct perf_event *event) | |
880 | { | |
881 | } | |
882 | ||
883 | static inline void | |
884 | perf_cgroup_mark_enabled(struct perf_event *event, | |
885 | struct perf_event_context *ctx) | |
886 | { | |
887 | } | |
888 | #endif | |
889 | ||
9e630205 SE |
890 | /* |
891 | * set default to be dependent on timer tick just | |
892 | * like original code | |
893 | */ | |
894 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
895 | /* | |
896 | * function must be called with interrupts disbled | |
897 | */ | |
272325c4 | 898 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
899 | { |
900 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
901 | int rotations = 0; |
902 | ||
903 | WARN_ON(!irqs_disabled()); | |
904 | ||
905 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
906 | rotations = perf_rotate_context(cpuctx); |
907 | ||
4cfafd30 PZ |
908 | raw_spin_lock(&cpuctx->hrtimer_lock); |
909 | if (rotations) | |
9e630205 | 910 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
911 | else |
912 | cpuctx->hrtimer_active = 0; | |
913 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 914 | |
4cfafd30 | 915 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
916 | } |
917 | ||
272325c4 | 918 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 919 | { |
272325c4 | 920 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 921 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 922 | u64 interval; |
9e630205 SE |
923 | |
924 | /* no multiplexing needed for SW PMU */ | |
925 | if (pmu->task_ctx_nr == perf_sw_context) | |
926 | return; | |
927 | ||
62b85639 SE |
928 | /* |
929 | * check default is sane, if not set then force to | |
930 | * default interval (1/tick) | |
931 | */ | |
272325c4 PZ |
932 | interval = pmu->hrtimer_interval_ms; |
933 | if (interval < 1) | |
934 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 935 | |
272325c4 | 936 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 937 | |
4cfafd30 PZ |
938 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
939 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 940 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
941 | } |
942 | ||
272325c4 | 943 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 944 | { |
272325c4 | 945 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 946 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 947 | unsigned long flags; |
9e630205 SE |
948 | |
949 | /* not for SW PMU */ | |
950 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 951 | return 0; |
9e630205 | 952 | |
4cfafd30 PZ |
953 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
954 | if (!cpuctx->hrtimer_active) { | |
955 | cpuctx->hrtimer_active = 1; | |
956 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
957 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
958 | } | |
959 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 960 | |
272325c4 | 961 | return 0; |
9e630205 SE |
962 | } |
963 | ||
33696fc0 | 964 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 965 | { |
33696fc0 PZ |
966 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
967 | if (!(*count)++) | |
968 | pmu->pmu_disable(pmu); | |
9e35ad38 | 969 | } |
9e35ad38 | 970 | |
33696fc0 | 971 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 972 | { |
33696fc0 PZ |
973 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
974 | if (!--(*count)) | |
975 | pmu->pmu_enable(pmu); | |
9e35ad38 | 976 | } |
9e35ad38 | 977 | |
2fde4f94 | 978 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
979 | |
980 | /* | |
2fde4f94 MR |
981 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
982 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
983 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
984 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 985 | */ |
2fde4f94 | 986 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 987 | { |
2fde4f94 | 988 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 989 | |
e9d2b064 | 990 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 991 | |
2fde4f94 MR |
992 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
993 | ||
994 | list_add(&ctx->active_ctx_list, head); | |
995 | } | |
996 | ||
997 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
998 | { | |
999 | WARN_ON(!irqs_disabled()); | |
1000 | ||
1001 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1002 | ||
1003 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1004 | } |
9e35ad38 | 1005 | |
cdd6c482 | 1006 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1007 | { |
e5289d4a | 1008 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1009 | } |
1010 | ||
4af57ef2 YZ |
1011 | static void free_ctx(struct rcu_head *head) |
1012 | { | |
1013 | struct perf_event_context *ctx; | |
1014 | ||
1015 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1016 | kfree(ctx->task_ctx_data); | |
1017 | kfree(ctx); | |
1018 | } | |
1019 | ||
cdd6c482 | 1020 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1021 | { |
564c2b21 PM |
1022 | if (atomic_dec_and_test(&ctx->refcount)) { |
1023 | if (ctx->parent_ctx) | |
1024 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1025 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1026 | put_task_struct(ctx->task); |
4af57ef2 | 1027 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1028 | } |
a63eaf34 PM |
1029 | } |
1030 | ||
f63a8daa PZ |
1031 | /* |
1032 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1033 | * perf_pmu_migrate_context() we need some magic. | |
1034 | * | |
1035 | * Those places that change perf_event::ctx will hold both | |
1036 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1037 | * | |
8b10c5e2 PZ |
1038 | * Lock ordering is by mutex address. There are two other sites where |
1039 | * perf_event_context::mutex nests and those are: | |
1040 | * | |
1041 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1042 | * perf_event_exit_event() |
1043 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1044 | * |
1045 | * - perf_event_init_context() [ parent, 0 ] | |
1046 | * inherit_task_group() | |
1047 | * inherit_group() | |
1048 | * inherit_event() | |
1049 | * perf_event_alloc() | |
1050 | * perf_init_event() | |
1051 | * perf_try_init_event() [ child , 1 ] | |
1052 | * | |
1053 | * While it appears there is an obvious deadlock here -- the parent and child | |
1054 | * nesting levels are inverted between the two. This is in fact safe because | |
1055 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1056 | * spawning task cannot (yet) exit. | |
1057 | * | |
1058 | * But remember that that these are parent<->child context relations, and | |
1059 | * migration does not affect children, therefore these two orderings should not | |
1060 | * interact. | |
f63a8daa PZ |
1061 | * |
1062 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1063 | * because the sys_perf_event_open() case will install a new event and break | |
1064 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1065 | * concerned with cpuctx and that doesn't have children. | |
1066 | * | |
1067 | * The places that change perf_event::ctx will issue: | |
1068 | * | |
1069 | * perf_remove_from_context(); | |
1070 | * synchronize_rcu(); | |
1071 | * perf_install_in_context(); | |
1072 | * | |
1073 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1074 | * quiesce the event, after which we can install it in the new location. This | |
1075 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1076 | * while in transit. Therefore all such accessors should also acquire | |
1077 | * perf_event_context::mutex to serialize against this. | |
1078 | * | |
1079 | * However; because event->ctx can change while we're waiting to acquire | |
1080 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1081 | * function. | |
1082 | * | |
1083 | * Lock order: | |
1084 | * task_struct::perf_event_mutex | |
1085 | * perf_event_context::mutex | |
f63a8daa | 1086 | * perf_event::child_mutex; |
07c4a776 | 1087 | * perf_event_context::lock |
f63a8daa PZ |
1088 | * perf_event::mmap_mutex |
1089 | * mmap_sem | |
1090 | */ | |
a83fe28e PZ |
1091 | static struct perf_event_context * |
1092 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1093 | { |
1094 | struct perf_event_context *ctx; | |
1095 | ||
1096 | again: | |
1097 | rcu_read_lock(); | |
1098 | ctx = ACCESS_ONCE(event->ctx); | |
1099 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1100 | rcu_read_unlock(); | |
1101 | goto again; | |
1102 | } | |
1103 | rcu_read_unlock(); | |
1104 | ||
a83fe28e | 1105 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1106 | if (event->ctx != ctx) { |
1107 | mutex_unlock(&ctx->mutex); | |
1108 | put_ctx(ctx); | |
1109 | goto again; | |
1110 | } | |
1111 | ||
1112 | return ctx; | |
1113 | } | |
1114 | ||
a83fe28e PZ |
1115 | static inline struct perf_event_context * |
1116 | perf_event_ctx_lock(struct perf_event *event) | |
1117 | { | |
1118 | return perf_event_ctx_lock_nested(event, 0); | |
1119 | } | |
1120 | ||
f63a8daa PZ |
1121 | static void perf_event_ctx_unlock(struct perf_event *event, |
1122 | struct perf_event_context *ctx) | |
1123 | { | |
1124 | mutex_unlock(&ctx->mutex); | |
1125 | put_ctx(ctx); | |
1126 | } | |
1127 | ||
211de6eb PZ |
1128 | /* |
1129 | * This must be done under the ctx->lock, such as to serialize against | |
1130 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1131 | * calling scheduler related locks and ctx->lock nests inside those. | |
1132 | */ | |
1133 | static __must_check struct perf_event_context * | |
1134 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1135 | { |
211de6eb PZ |
1136 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1137 | ||
1138 | lockdep_assert_held(&ctx->lock); | |
1139 | ||
1140 | if (parent_ctx) | |
71a851b4 | 1141 | ctx->parent_ctx = NULL; |
5a3126d4 | 1142 | ctx->generation++; |
211de6eb PZ |
1143 | |
1144 | return parent_ctx; | |
71a851b4 PZ |
1145 | } |
1146 | ||
6844c09d ACM |
1147 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1148 | { | |
1149 | /* | |
1150 | * only top level events have the pid namespace they were created in | |
1151 | */ | |
1152 | if (event->parent) | |
1153 | event = event->parent; | |
1154 | ||
1155 | return task_tgid_nr_ns(p, event->ns); | |
1156 | } | |
1157 | ||
1158 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1159 | { | |
1160 | /* | |
1161 | * only top level events have the pid namespace they were created in | |
1162 | */ | |
1163 | if (event->parent) | |
1164 | event = event->parent; | |
1165 | ||
1166 | return task_pid_nr_ns(p, event->ns); | |
1167 | } | |
1168 | ||
7f453c24 | 1169 | /* |
cdd6c482 | 1170 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1171 | * to userspace. |
1172 | */ | |
cdd6c482 | 1173 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1174 | { |
cdd6c482 | 1175 | u64 id = event->id; |
7f453c24 | 1176 | |
cdd6c482 IM |
1177 | if (event->parent) |
1178 | id = event->parent->id; | |
7f453c24 PZ |
1179 | |
1180 | return id; | |
1181 | } | |
1182 | ||
25346b93 | 1183 | /* |
cdd6c482 | 1184 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1185 | * |
25346b93 PM |
1186 | * This has to cope with with the fact that until it is locked, |
1187 | * the context could get moved to another task. | |
1188 | */ | |
cdd6c482 | 1189 | static struct perf_event_context * |
8dc85d54 | 1190 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1191 | { |
cdd6c482 | 1192 | struct perf_event_context *ctx; |
25346b93 | 1193 | |
9ed6060d | 1194 | retry: |
058ebd0e PZ |
1195 | /* |
1196 | * One of the few rules of preemptible RCU is that one cannot do | |
1197 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1198 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1199 | * rcu_read_unlock_special(). |
1200 | * | |
1201 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1202 | * side critical section has interrupts disabled. |
058ebd0e | 1203 | */ |
2fd59077 | 1204 | local_irq_save(*flags); |
058ebd0e | 1205 | rcu_read_lock(); |
8dc85d54 | 1206 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1207 | if (ctx) { |
1208 | /* | |
1209 | * If this context is a clone of another, it might | |
1210 | * get swapped for another underneath us by | |
cdd6c482 | 1211 | * perf_event_task_sched_out, though the |
25346b93 PM |
1212 | * rcu_read_lock() protects us from any context |
1213 | * getting freed. Lock the context and check if it | |
1214 | * got swapped before we could get the lock, and retry | |
1215 | * if so. If we locked the right context, then it | |
1216 | * can't get swapped on us any more. | |
1217 | */ | |
2fd59077 | 1218 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1219 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1220 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1221 | rcu_read_unlock(); |
2fd59077 | 1222 | local_irq_restore(*flags); |
25346b93 PM |
1223 | goto retry; |
1224 | } | |
b49a9e7e | 1225 | |
63b6da39 PZ |
1226 | if (ctx->task == TASK_TOMBSTONE || |
1227 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1228 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1229 | ctx = NULL; |
828b6f0e PZ |
1230 | } else { |
1231 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1232 | } |
25346b93 PM |
1233 | } |
1234 | rcu_read_unlock(); | |
2fd59077 PM |
1235 | if (!ctx) |
1236 | local_irq_restore(*flags); | |
25346b93 PM |
1237 | return ctx; |
1238 | } | |
1239 | ||
1240 | /* | |
1241 | * Get the context for a task and increment its pin_count so it | |
1242 | * can't get swapped to another task. This also increments its | |
1243 | * reference count so that the context can't get freed. | |
1244 | */ | |
8dc85d54 PZ |
1245 | static struct perf_event_context * |
1246 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1247 | { |
cdd6c482 | 1248 | struct perf_event_context *ctx; |
25346b93 PM |
1249 | unsigned long flags; |
1250 | ||
8dc85d54 | 1251 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1252 | if (ctx) { |
1253 | ++ctx->pin_count; | |
e625cce1 | 1254 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1255 | } |
1256 | return ctx; | |
1257 | } | |
1258 | ||
cdd6c482 | 1259 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1260 | { |
1261 | unsigned long flags; | |
1262 | ||
e625cce1 | 1263 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1264 | --ctx->pin_count; |
e625cce1 | 1265 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1266 | } |
1267 | ||
f67218c3 PZ |
1268 | /* |
1269 | * Update the record of the current time in a context. | |
1270 | */ | |
1271 | static void update_context_time(struct perf_event_context *ctx) | |
1272 | { | |
1273 | u64 now = perf_clock(); | |
1274 | ||
1275 | ctx->time += now - ctx->timestamp; | |
1276 | ctx->timestamp = now; | |
1277 | } | |
1278 | ||
4158755d SE |
1279 | static u64 perf_event_time(struct perf_event *event) |
1280 | { | |
1281 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1282 | |
1283 | if (is_cgroup_event(event)) | |
1284 | return perf_cgroup_event_time(event); | |
1285 | ||
4158755d SE |
1286 | return ctx ? ctx->time : 0; |
1287 | } | |
1288 | ||
f67218c3 PZ |
1289 | /* |
1290 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1291 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1292 | */ |
1293 | static void update_event_times(struct perf_event *event) | |
1294 | { | |
1295 | struct perf_event_context *ctx = event->ctx; | |
1296 | u64 run_end; | |
1297 | ||
1298 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1299 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1300 | return; | |
e5d1367f SE |
1301 | /* |
1302 | * in cgroup mode, time_enabled represents | |
1303 | * the time the event was enabled AND active | |
1304 | * tasks were in the monitored cgroup. This is | |
1305 | * independent of the activity of the context as | |
1306 | * there may be a mix of cgroup and non-cgroup events. | |
1307 | * | |
1308 | * That is why we treat cgroup events differently | |
1309 | * here. | |
1310 | */ | |
1311 | if (is_cgroup_event(event)) | |
46cd6a7f | 1312 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1313 | else if (ctx->is_active) |
1314 | run_end = ctx->time; | |
acd1d7c1 PZ |
1315 | else |
1316 | run_end = event->tstamp_stopped; | |
1317 | ||
1318 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1319 | |
1320 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1321 | run_end = event->tstamp_stopped; | |
1322 | else | |
4158755d | 1323 | run_end = perf_event_time(event); |
f67218c3 PZ |
1324 | |
1325 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1326 | |
f67218c3 PZ |
1327 | } |
1328 | ||
96c21a46 PZ |
1329 | /* |
1330 | * Update total_time_enabled and total_time_running for all events in a group. | |
1331 | */ | |
1332 | static void update_group_times(struct perf_event *leader) | |
1333 | { | |
1334 | struct perf_event *event; | |
1335 | ||
1336 | update_event_times(leader); | |
1337 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1338 | update_event_times(event); | |
1339 | } | |
1340 | ||
889ff015 FW |
1341 | static struct list_head * |
1342 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1343 | { | |
1344 | if (event->attr.pinned) | |
1345 | return &ctx->pinned_groups; | |
1346 | else | |
1347 | return &ctx->flexible_groups; | |
1348 | } | |
1349 | ||
fccc714b | 1350 | /* |
cdd6c482 | 1351 | * Add a event from the lists for its context. |
fccc714b PZ |
1352 | * Must be called with ctx->mutex and ctx->lock held. |
1353 | */ | |
04289bb9 | 1354 | static void |
cdd6c482 | 1355 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1356 | { |
c994d613 PZ |
1357 | lockdep_assert_held(&ctx->lock); |
1358 | ||
8a49542c PZ |
1359 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1360 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1361 | |
1362 | /* | |
8a49542c PZ |
1363 | * If we're a stand alone event or group leader, we go to the context |
1364 | * list, group events are kept attached to the group so that | |
1365 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1366 | */ |
8a49542c | 1367 | if (event->group_leader == event) { |
889ff015 FW |
1368 | struct list_head *list; |
1369 | ||
d6f962b5 FW |
1370 | if (is_software_event(event)) |
1371 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1372 | ||
889ff015 FW |
1373 | list = ctx_group_list(event, ctx); |
1374 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1375 | } |
592903cd | 1376 | |
08309379 | 1377 | if (is_cgroup_event(event)) |
e5d1367f | 1378 | ctx->nr_cgroups++; |
e5d1367f | 1379 | |
cdd6c482 IM |
1380 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1381 | ctx->nr_events++; | |
1382 | if (event->attr.inherit_stat) | |
bfbd3381 | 1383 | ctx->nr_stat++; |
5a3126d4 PZ |
1384 | |
1385 | ctx->generation++; | |
04289bb9 IM |
1386 | } |
1387 | ||
0231bb53 JO |
1388 | /* |
1389 | * Initialize event state based on the perf_event_attr::disabled. | |
1390 | */ | |
1391 | static inline void perf_event__state_init(struct perf_event *event) | |
1392 | { | |
1393 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1394 | PERF_EVENT_STATE_INACTIVE; | |
1395 | } | |
1396 | ||
a723968c | 1397 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1398 | { |
1399 | int entry = sizeof(u64); /* value */ | |
1400 | int size = 0; | |
1401 | int nr = 1; | |
1402 | ||
1403 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1404 | size += sizeof(u64); | |
1405 | ||
1406 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1407 | size += sizeof(u64); | |
1408 | ||
1409 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1410 | entry += sizeof(u64); | |
1411 | ||
1412 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1413 | nr += nr_siblings; |
c320c7b7 ACM |
1414 | size += sizeof(u64); |
1415 | } | |
1416 | ||
1417 | size += entry * nr; | |
1418 | event->read_size = size; | |
1419 | } | |
1420 | ||
a723968c | 1421 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1422 | { |
1423 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1424 | u16 size = 0; |
1425 | ||
c320c7b7 ACM |
1426 | if (sample_type & PERF_SAMPLE_IP) |
1427 | size += sizeof(data->ip); | |
1428 | ||
6844c09d ACM |
1429 | if (sample_type & PERF_SAMPLE_ADDR) |
1430 | size += sizeof(data->addr); | |
1431 | ||
1432 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1433 | size += sizeof(data->period); | |
1434 | ||
c3feedf2 AK |
1435 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1436 | size += sizeof(data->weight); | |
1437 | ||
6844c09d ACM |
1438 | if (sample_type & PERF_SAMPLE_READ) |
1439 | size += event->read_size; | |
1440 | ||
d6be9ad6 SE |
1441 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1442 | size += sizeof(data->data_src.val); | |
1443 | ||
fdfbbd07 AK |
1444 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1445 | size += sizeof(data->txn); | |
1446 | ||
6844c09d ACM |
1447 | event->header_size = size; |
1448 | } | |
1449 | ||
a723968c PZ |
1450 | /* |
1451 | * Called at perf_event creation and when events are attached/detached from a | |
1452 | * group. | |
1453 | */ | |
1454 | static void perf_event__header_size(struct perf_event *event) | |
1455 | { | |
1456 | __perf_event_read_size(event, | |
1457 | event->group_leader->nr_siblings); | |
1458 | __perf_event_header_size(event, event->attr.sample_type); | |
1459 | } | |
1460 | ||
6844c09d ACM |
1461 | static void perf_event__id_header_size(struct perf_event *event) |
1462 | { | |
1463 | struct perf_sample_data *data; | |
1464 | u64 sample_type = event->attr.sample_type; | |
1465 | u16 size = 0; | |
1466 | ||
c320c7b7 ACM |
1467 | if (sample_type & PERF_SAMPLE_TID) |
1468 | size += sizeof(data->tid_entry); | |
1469 | ||
1470 | if (sample_type & PERF_SAMPLE_TIME) | |
1471 | size += sizeof(data->time); | |
1472 | ||
ff3d527c AH |
1473 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1474 | size += sizeof(data->id); | |
1475 | ||
c320c7b7 ACM |
1476 | if (sample_type & PERF_SAMPLE_ID) |
1477 | size += sizeof(data->id); | |
1478 | ||
1479 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1480 | size += sizeof(data->stream_id); | |
1481 | ||
1482 | if (sample_type & PERF_SAMPLE_CPU) | |
1483 | size += sizeof(data->cpu_entry); | |
1484 | ||
6844c09d | 1485 | event->id_header_size = size; |
c320c7b7 ACM |
1486 | } |
1487 | ||
a723968c PZ |
1488 | static bool perf_event_validate_size(struct perf_event *event) |
1489 | { | |
1490 | /* | |
1491 | * The values computed here will be over-written when we actually | |
1492 | * attach the event. | |
1493 | */ | |
1494 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1495 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1496 | perf_event__id_header_size(event); | |
1497 | ||
1498 | /* | |
1499 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1500 | * Conservative limit to allow for callchains and other variable fields. | |
1501 | */ | |
1502 | if (event->read_size + event->header_size + | |
1503 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1504 | return false; | |
1505 | ||
1506 | return true; | |
1507 | } | |
1508 | ||
8a49542c PZ |
1509 | static void perf_group_attach(struct perf_event *event) |
1510 | { | |
c320c7b7 | 1511 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1512 | |
74c3337c PZ |
1513 | /* |
1514 | * We can have double attach due to group movement in perf_event_open. | |
1515 | */ | |
1516 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1517 | return; | |
1518 | ||
8a49542c PZ |
1519 | event->attach_state |= PERF_ATTACH_GROUP; |
1520 | ||
1521 | if (group_leader == event) | |
1522 | return; | |
1523 | ||
652884fe PZ |
1524 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1525 | ||
8a49542c PZ |
1526 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1527 | !is_software_event(event)) | |
1528 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1529 | ||
1530 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1531 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1532 | |
1533 | perf_event__header_size(group_leader); | |
1534 | ||
1535 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1536 | perf_event__header_size(pos); | |
8a49542c PZ |
1537 | } |
1538 | ||
a63eaf34 | 1539 | /* |
cdd6c482 | 1540 | * Remove a event from the lists for its context. |
fccc714b | 1541 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1542 | */ |
04289bb9 | 1543 | static void |
cdd6c482 | 1544 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1545 | { |
68cacd29 | 1546 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1547 | |
1548 | WARN_ON_ONCE(event->ctx != ctx); | |
1549 | lockdep_assert_held(&ctx->lock); | |
1550 | ||
8a49542c PZ |
1551 | /* |
1552 | * We can have double detach due to exit/hot-unplug + close. | |
1553 | */ | |
1554 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1555 | return; |
8a49542c PZ |
1556 | |
1557 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1558 | ||
68cacd29 | 1559 | if (is_cgroup_event(event)) { |
e5d1367f | 1560 | ctx->nr_cgroups--; |
70a01657 PZ |
1561 | /* |
1562 | * Because cgroup events are always per-cpu events, this will | |
1563 | * always be called from the right CPU. | |
1564 | */ | |
68cacd29 SE |
1565 | cpuctx = __get_cpu_context(ctx); |
1566 | /* | |
70a01657 PZ |
1567 | * If there are no more cgroup events then clear cgrp to avoid |
1568 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1569 | */ |
1570 | if (!ctx->nr_cgroups) | |
1571 | cpuctx->cgrp = NULL; | |
1572 | } | |
e5d1367f | 1573 | |
cdd6c482 IM |
1574 | ctx->nr_events--; |
1575 | if (event->attr.inherit_stat) | |
bfbd3381 | 1576 | ctx->nr_stat--; |
8bc20959 | 1577 | |
cdd6c482 | 1578 | list_del_rcu(&event->event_entry); |
04289bb9 | 1579 | |
8a49542c PZ |
1580 | if (event->group_leader == event) |
1581 | list_del_init(&event->group_entry); | |
5c148194 | 1582 | |
96c21a46 | 1583 | update_group_times(event); |
b2e74a26 SE |
1584 | |
1585 | /* | |
1586 | * If event was in error state, then keep it | |
1587 | * that way, otherwise bogus counts will be | |
1588 | * returned on read(). The only way to get out | |
1589 | * of error state is by explicit re-enabling | |
1590 | * of the event | |
1591 | */ | |
1592 | if (event->state > PERF_EVENT_STATE_OFF) | |
1593 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1594 | |
1595 | ctx->generation++; | |
050735b0 PZ |
1596 | } |
1597 | ||
8a49542c | 1598 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1599 | { |
1600 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1601 | struct list_head *list = NULL; |
1602 | ||
1603 | /* | |
1604 | * We can have double detach due to exit/hot-unplug + close. | |
1605 | */ | |
1606 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1607 | return; | |
1608 | ||
1609 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1610 | ||
1611 | /* | |
1612 | * If this is a sibling, remove it from its group. | |
1613 | */ | |
1614 | if (event->group_leader != event) { | |
1615 | list_del_init(&event->group_entry); | |
1616 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1617 | goto out; |
8a49542c PZ |
1618 | } |
1619 | ||
1620 | if (!list_empty(&event->group_entry)) | |
1621 | list = &event->group_entry; | |
2e2af50b | 1622 | |
04289bb9 | 1623 | /* |
cdd6c482 IM |
1624 | * If this was a group event with sibling events then |
1625 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1626 | * to whatever list we are on. |
04289bb9 | 1627 | */ |
cdd6c482 | 1628 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1629 | if (list) |
1630 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1631 | sibling->group_leader = sibling; |
d6f962b5 FW |
1632 | |
1633 | /* Inherit group flags from the previous leader */ | |
1634 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1635 | |
1636 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1637 | } |
c320c7b7 ACM |
1638 | |
1639 | out: | |
1640 | perf_event__header_size(event->group_leader); | |
1641 | ||
1642 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1643 | perf_event__header_size(tmp); | |
04289bb9 IM |
1644 | } |
1645 | ||
fadfe7be JO |
1646 | static bool is_orphaned_event(struct perf_event *event) |
1647 | { | |
a69b0ca4 | 1648 | return event->state == PERF_EVENT_STATE_DEAD; |
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 |
0017960f | 1735 | |
0793a61d | 1736 | /* |
cdd6c482 | 1737 | * Cross CPU call to remove a performance event |
0793a61d | 1738 | * |
cdd6c482 | 1739 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1740 | * remove it from the context list. |
1741 | */ | |
fae3fde6 PZ |
1742 | static void |
1743 | __perf_remove_from_context(struct perf_event *event, | |
1744 | struct perf_cpu_context *cpuctx, | |
1745 | struct perf_event_context *ctx, | |
1746 | void *info) | |
0793a61d | 1747 | { |
45a0e07a | 1748 | unsigned long flags = (unsigned long)info; |
0793a61d | 1749 | |
cdd6c482 | 1750 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1751 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1752 | perf_group_detach(event); |
cdd6c482 | 1753 | list_del_event(event, ctx); |
39a43640 PZ |
1754 | |
1755 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1756 | ctx->is_active = 0; |
39a43640 PZ |
1757 | if (ctx->task) { |
1758 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1759 | cpuctx->task_ctx = NULL; | |
1760 | } | |
64ce3126 | 1761 | } |
0793a61d TG |
1762 | } |
1763 | ||
0793a61d | 1764 | /* |
cdd6c482 | 1765 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1766 | * |
cdd6c482 IM |
1767 | * If event->ctx is a cloned context, callers must make sure that |
1768 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1769 | * remains valid. This is OK when called from perf_release since |
1770 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1771 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1772 | * context has been detached from its task. |
0793a61d | 1773 | */ |
45a0e07a | 1774 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1775 | { |
fae3fde6 | 1776 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1777 | |
45a0e07a | 1778 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1779 | } |
1780 | ||
d859e29f | 1781 | /* |
cdd6c482 | 1782 | * Cross CPU call to disable a performance event |
d859e29f | 1783 | */ |
fae3fde6 PZ |
1784 | static void __perf_event_disable(struct perf_event *event, |
1785 | struct perf_cpu_context *cpuctx, | |
1786 | struct perf_event_context *ctx, | |
1787 | void *info) | |
7b648018 | 1788 | { |
fae3fde6 PZ |
1789 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1790 | return; | |
7b648018 | 1791 | |
fae3fde6 PZ |
1792 | update_context_time(ctx); |
1793 | update_cgrp_time_from_event(event); | |
1794 | update_group_times(event); | |
1795 | if (event == event->group_leader) | |
1796 | group_sched_out(event, cpuctx, ctx); | |
1797 | else | |
1798 | event_sched_out(event, cpuctx, ctx); | |
1799 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1800 | } |
1801 | ||
d859e29f | 1802 | /* |
cdd6c482 | 1803 | * Disable a event. |
c93f7669 | 1804 | * |
cdd6c482 IM |
1805 | * If event->ctx is a cloned context, callers must make sure that |
1806 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1807 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1808 | * perf_event_for_each_child or perf_event_for_each because they |
1809 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1810 | * goes to exit will block in perf_event_exit_event(). |
1811 | * | |
cdd6c482 | 1812 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1813 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1814 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1815 | */ |
f63a8daa | 1816 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1817 | { |
cdd6c482 | 1818 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1819 | |
e625cce1 | 1820 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1821 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1822 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1823 | return; |
53cfbf59 | 1824 | } |
e625cce1 | 1825 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1826 | |
fae3fde6 PZ |
1827 | event_function_call(event, __perf_event_disable, NULL); |
1828 | } | |
1829 | ||
1830 | void perf_event_disable_local(struct perf_event *event) | |
1831 | { | |
1832 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1833 | } |
f63a8daa PZ |
1834 | |
1835 | /* | |
1836 | * Strictly speaking kernel users cannot create groups and therefore this | |
1837 | * interface does not need the perf_event_ctx_lock() magic. | |
1838 | */ | |
1839 | void perf_event_disable(struct perf_event *event) | |
1840 | { | |
1841 | struct perf_event_context *ctx; | |
1842 | ||
1843 | ctx = perf_event_ctx_lock(event); | |
1844 | _perf_event_disable(event); | |
1845 | perf_event_ctx_unlock(event, ctx); | |
1846 | } | |
dcfce4a0 | 1847 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1848 | |
e5d1367f SE |
1849 | static void perf_set_shadow_time(struct perf_event *event, |
1850 | struct perf_event_context *ctx, | |
1851 | u64 tstamp) | |
1852 | { | |
1853 | /* | |
1854 | * use the correct time source for the time snapshot | |
1855 | * | |
1856 | * We could get by without this by leveraging the | |
1857 | * fact that to get to this function, the caller | |
1858 | * has most likely already called update_context_time() | |
1859 | * and update_cgrp_time_xx() and thus both timestamp | |
1860 | * are identical (or very close). Given that tstamp is, | |
1861 | * already adjusted for cgroup, we could say that: | |
1862 | * tstamp - ctx->timestamp | |
1863 | * is equivalent to | |
1864 | * tstamp - cgrp->timestamp. | |
1865 | * | |
1866 | * Then, in perf_output_read(), the calculation would | |
1867 | * work with no changes because: | |
1868 | * - event is guaranteed scheduled in | |
1869 | * - no scheduled out in between | |
1870 | * - thus the timestamp would be the same | |
1871 | * | |
1872 | * But this is a bit hairy. | |
1873 | * | |
1874 | * So instead, we have an explicit cgroup call to remain | |
1875 | * within the time time source all along. We believe it | |
1876 | * is cleaner and simpler to understand. | |
1877 | */ | |
1878 | if (is_cgroup_event(event)) | |
1879 | perf_cgroup_set_shadow_time(event, tstamp); | |
1880 | else | |
1881 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1882 | } | |
1883 | ||
4fe757dd PZ |
1884 | #define MAX_INTERRUPTS (~0ULL) |
1885 | ||
1886 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1887 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1888 | |
235c7fc7 | 1889 | static int |
9ffcfa6f | 1890 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1891 | struct perf_cpu_context *cpuctx, |
6e37738a | 1892 | struct perf_event_context *ctx) |
235c7fc7 | 1893 | { |
4158755d | 1894 | u64 tstamp = perf_event_time(event); |
44377277 | 1895 | int ret = 0; |
4158755d | 1896 | |
63342411 PZ |
1897 | lockdep_assert_held(&ctx->lock); |
1898 | ||
cdd6c482 | 1899 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1900 | return 0; |
1901 | ||
cdd6c482 | 1902 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1903 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1904 | |
1905 | /* | |
1906 | * Unthrottle events, since we scheduled we might have missed several | |
1907 | * ticks already, also for a heavily scheduling task there is little | |
1908 | * guarantee it'll get a tick in a timely manner. | |
1909 | */ | |
1910 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1911 | perf_log_throttle(event, 1); | |
1912 | event->hw.interrupts = 0; | |
1913 | } | |
1914 | ||
235c7fc7 IM |
1915 | /* |
1916 | * The new state must be visible before we turn it on in the hardware: | |
1917 | */ | |
1918 | smp_wmb(); | |
1919 | ||
44377277 AS |
1920 | perf_pmu_disable(event->pmu); |
1921 | ||
72f669c0 SL |
1922 | perf_set_shadow_time(event, ctx, tstamp); |
1923 | ||
ec0d7729 AS |
1924 | perf_log_itrace_start(event); |
1925 | ||
a4eaf7f1 | 1926 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1927 | event->state = PERF_EVENT_STATE_INACTIVE; |
1928 | event->oncpu = -1; | |
44377277 AS |
1929 | ret = -EAGAIN; |
1930 | goto out; | |
235c7fc7 IM |
1931 | } |
1932 | ||
00a2916f PZ |
1933 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1934 | ||
cdd6c482 | 1935 | if (!is_software_event(event)) |
3b6f9e5c | 1936 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1937 | if (!ctx->nr_active++) |
1938 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1939 | if (event->attr.freq && event->attr.sample_freq) |
1940 | ctx->nr_freq++; | |
235c7fc7 | 1941 | |
cdd6c482 | 1942 | if (event->attr.exclusive) |
3b6f9e5c PM |
1943 | cpuctx->exclusive = 1; |
1944 | ||
44377277 AS |
1945 | out: |
1946 | perf_pmu_enable(event->pmu); | |
1947 | ||
1948 | return ret; | |
235c7fc7 IM |
1949 | } |
1950 | ||
6751b71e | 1951 | static int |
cdd6c482 | 1952 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1953 | struct perf_cpu_context *cpuctx, |
6e37738a | 1954 | struct perf_event_context *ctx) |
6751b71e | 1955 | { |
6bde9b6c | 1956 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1957 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1958 | u64 now = ctx->time; |
1959 | bool simulate = false; | |
6751b71e | 1960 | |
cdd6c482 | 1961 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1962 | return 0; |
1963 | ||
fbbe0701 | 1964 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1965 | |
9ffcfa6f | 1966 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1967 | pmu->cancel_txn(pmu); |
272325c4 | 1968 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1969 | return -EAGAIN; |
90151c35 | 1970 | } |
6751b71e PM |
1971 | |
1972 | /* | |
1973 | * Schedule in siblings as one group (if any): | |
1974 | */ | |
cdd6c482 | 1975 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1976 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1977 | partial_group = event; |
6751b71e PM |
1978 | goto group_error; |
1979 | } | |
1980 | } | |
1981 | ||
9ffcfa6f | 1982 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1983 | return 0; |
9ffcfa6f | 1984 | |
6751b71e PM |
1985 | group_error: |
1986 | /* | |
1987 | * Groups can be scheduled in as one unit only, so undo any | |
1988 | * partial group before returning: | |
d7842da4 SE |
1989 | * The events up to the failed event are scheduled out normally, |
1990 | * tstamp_stopped will be updated. | |
1991 | * | |
1992 | * The failed events and the remaining siblings need to have | |
1993 | * their timings updated as if they had gone thru event_sched_in() | |
1994 | * and event_sched_out(). This is required to get consistent timings | |
1995 | * across the group. This also takes care of the case where the group | |
1996 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1997 | * the time the event was actually stopped, such that time delta | |
1998 | * calculation in update_event_times() is correct. | |
6751b71e | 1999 | */ |
cdd6c482 IM |
2000 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2001 | if (event == partial_group) | |
d7842da4 SE |
2002 | simulate = true; |
2003 | ||
2004 | if (simulate) { | |
2005 | event->tstamp_running += now - event->tstamp_stopped; | |
2006 | event->tstamp_stopped = now; | |
2007 | } else { | |
2008 | event_sched_out(event, cpuctx, ctx); | |
2009 | } | |
6751b71e | 2010 | } |
9ffcfa6f | 2011 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2012 | |
ad5133b7 | 2013 | pmu->cancel_txn(pmu); |
90151c35 | 2014 | |
272325c4 | 2015 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2016 | |
6751b71e PM |
2017 | return -EAGAIN; |
2018 | } | |
2019 | ||
3b6f9e5c | 2020 | /* |
cdd6c482 | 2021 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2022 | */ |
cdd6c482 | 2023 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2024 | struct perf_cpu_context *cpuctx, |
2025 | int can_add_hw) | |
2026 | { | |
2027 | /* | |
cdd6c482 | 2028 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2029 | */ |
d6f962b5 | 2030 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2031 | return 1; |
2032 | /* | |
2033 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2034 | * events can go on. |
3b6f9e5c PM |
2035 | */ |
2036 | if (cpuctx->exclusive) | |
2037 | return 0; | |
2038 | /* | |
2039 | * If this group is exclusive and there are already | |
cdd6c482 | 2040 | * events on the CPU, it can't go on. |
3b6f9e5c | 2041 | */ |
cdd6c482 | 2042 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2043 | return 0; |
2044 | /* | |
2045 | * Otherwise, try to add it if all previous groups were able | |
2046 | * to go on. | |
2047 | */ | |
2048 | return can_add_hw; | |
2049 | } | |
2050 | ||
cdd6c482 IM |
2051 | static void add_event_to_ctx(struct perf_event *event, |
2052 | struct perf_event_context *ctx) | |
53cfbf59 | 2053 | { |
4158755d SE |
2054 | u64 tstamp = perf_event_time(event); |
2055 | ||
cdd6c482 | 2056 | list_add_event(event, ctx); |
8a49542c | 2057 | perf_group_attach(event); |
4158755d SE |
2058 | event->tstamp_enabled = tstamp; |
2059 | event->tstamp_running = tstamp; | |
2060 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2061 | } |
2062 | ||
3e349507 PZ |
2063 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2064 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2065 | static void |
2066 | ctx_sched_in(struct perf_event_context *ctx, | |
2067 | struct perf_cpu_context *cpuctx, | |
2068 | enum event_type_t event_type, | |
2069 | struct task_struct *task); | |
fe4b04fa | 2070 | |
dce5855b PZ |
2071 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2072 | struct perf_event_context *ctx, | |
2073 | struct task_struct *task) | |
2074 | { | |
2075 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2076 | if (ctx) | |
2077 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2078 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2079 | if (ctx) | |
2080 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2081 | } | |
2082 | ||
3e349507 PZ |
2083 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2084 | struct perf_event_context *task_ctx) | |
0017960f | 2085 | { |
3e349507 PZ |
2086 | perf_pmu_disable(cpuctx->ctx.pmu); |
2087 | if (task_ctx) | |
2088 | task_ctx_sched_out(cpuctx, task_ctx); | |
2089 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2090 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2091 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2092 | } |
2093 | ||
0793a61d | 2094 | /* |
cdd6c482 | 2095 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2096 | * |
2097 | * Must be called with ctx->mutex held | |
0793a61d | 2098 | */ |
fe4b04fa | 2099 | static int __perf_install_in_context(void *info) |
0793a61d | 2100 | { |
39a43640 | 2101 | struct perf_event_context *ctx = info; |
108b02cf | 2102 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2103 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
0793a61d | 2104 | |
63b6da39 | 2105 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2106 | if (ctx->task) { |
b58f6b0d | 2107 | raw_spin_lock(&ctx->lock); |
39a43640 PZ |
2108 | /* |
2109 | * If we hit the 'wrong' task, we've since scheduled and | |
2110 | * everything should be sorted, nothing to do! | |
2111 | */ | |
b58f6b0d | 2112 | task_ctx = ctx; |
39a43640 | 2113 | if (ctx->task != current) |
63b6da39 | 2114 | goto unlock; |
b58f6b0d | 2115 | |
39a43640 PZ |
2116 | /* |
2117 | * If task_ctx is set, it had better be to us. | |
2118 | */ | |
2119 | WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx); | |
63b6da39 PZ |
2120 | } else if (task_ctx) { |
2121 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2122 | } |
b58f6b0d | 2123 | |
39a43640 | 2124 | ctx_resched(cpuctx, task_ctx); |
63b6da39 | 2125 | unlock: |
2c29ef0f | 2126 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2127 | |
2128 | return 0; | |
0793a61d TG |
2129 | } |
2130 | ||
2131 | /* | |
cdd6c482 | 2132 | * Attach a performance event to a context |
0793a61d TG |
2133 | */ |
2134 | static void | |
cdd6c482 IM |
2135 | perf_install_in_context(struct perf_event_context *ctx, |
2136 | struct perf_event *event, | |
0793a61d TG |
2137 | int cpu) |
2138 | { | |
39a43640 PZ |
2139 | struct task_struct *task = NULL; |
2140 | ||
fe4b04fa PZ |
2141 | lockdep_assert_held(&ctx->mutex); |
2142 | ||
c3f00c70 | 2143 | event->ctx = ctx; |
0cda4c02 YZ |
2144 | if (event->cpu != -1) |
2145 | event->cpu = cpu; | |
c3f00c70 | 2146 | |
39a43640 PZ |
2147 | /* |
2148 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2149 | * to be set in case this is the nr_events 0 -> 1 transition. | |
2150 | * | |
2151 | * So what we do is we add the event to the list here, which will allow | |
2152 | * a future context switch to DTRT and then send a racy IPI. If the IPI | |
2153 | * fails to hit the right task, this means a context switch must have | |
2154 | * happened and that will have taken care of business. | |
2155 | */ | |
2156 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 | 2157 | task = ctx->task; |
84c4e620 | 2158 | |
63b6da39 | 2159 | /* |
84c4e620 PZ |
2160 | * If between ctx = find_get_context() and mutex_lock(&ctx->mutex) the |
2161 | * ctx gets destroyed, we must not install an event into it. | |
2162 | * | |
2163 | * This is normally tested for after we acquire the mutex, so this is | |
2164 | * a sanity check. | |
63b6da39 | 2165 | */ |
84c4e620 | 2166 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
63b6da39 PZ |
2167 | raw_spin_unlock_irq(&ctx->lock); |
2168 | return; | |
2169 | } | |
6f932e5b PZ |
2170 | |
2171 | if (ctx->is_active) { | |
2172 | update_context_time(ctx); | |
2173 | update_cgrp_time_from_event(event); | |
2174 | } | |
2175 | ||
39a43640 | 2176 | add_event_to_ctx(event, ctx); |
39a43640 PZ |
2177 | raw_spin_unlock_irq(&ctx->lock); |
2178 | ||
2179 | if (task) | |
2180 | task_function_call(task, __perf_install_in_context, ctx); | |
2181 | else | |
2182 | cpu_function_call(cpu, __perf_install_in_context, ctx); | |
0793a61d TG |
2183 | } |
2184 | ||
fa289bec | 2185 | /* |
cdd6c482 | 2186 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2187 | * Enabling the leader of a group effectively enables all |
2188 | * the group members that aren't explicitly disabled, so we | |
2189 | * have to update their ->tstamp_enabled also. | |
2190 | * Note: this works for group members as well as group leaders | |
2191 | * since the non-leader members' sibling_lists will be empty. | |
2192 | */ | |
1d9b482e | 2193 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2194 | { |
cdd6c482 | 2195 | struct perf_event *sub; |
4158755d | 2196 | u64 tstamp = perf_event_time(event); |
fa289bec | 2197 | |
cdd6c482 | 2198 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2199 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2200 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2201 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2202 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2203 | } |
fa289bec PM |
2204 | } |
2205 | ||
d859e29f | 2206 | /* |
cdd6c482 | 2207 | * Cross CPU call to enable a performance event |
d859e29f | 2208 | */ |
fae3fde6 PZ |
2209 | static void __perf_event_enable(struct perf_event *event, |
2210 | struct perf_cpu_context *cpuctx, | |
2211 | struct perf_event_context *ctx, | |
2212 | void *info) | |
04289bb9 | 2213 | { |
cdd6c482 | 2214 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2215 | struct perf_event_context *task_ctx; |
04289bb9 | 2216 | |
6e801e01 PZ |
2217 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2218 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2219 | return; |
3cbed429 | 2220 | |
4af4998b | 2221 | update_context_time(ctx); |
1d9b482e | 2222 | __perf_event_mark_enabled(event); |
04289bb9 | 2223 | |
fae3fde6 PZ |
2224 | if (!ctx->is_active) |
2225 | return; | |
2226 | ||
e5d1367f | 2227 | if (!event_filter_match(event)) { |
fae3fde6 PZ |
2228 | if (is_cgroup_event(event)) { |
2229 | perf_cgroup_set_timestamp(current, ctx); // XXX ? | |
e5d1367f | 2230 | perf_cgroup_defer_enabled(event); |
fae3fde6 PZ |
2231 | } |
2232 | return; | |
e5d1367f | 2233 | } |
f4c4176f | 2234 | |
04289bb9 | 2235 | /* |
cdd6c482 | 2236 | * If the event is in a group and isn't the group leader, |
d859e29f | 2237 | * then don't put it on unless the group is on. |
04289bb9 | 2238 | */ |
cdd6c482 | 2239 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
fae3fde6 | 2240 | return; |
fe4b04fa | 2241 | |
fae3fde6 PZ |
2242 | task_ctx = cpuctx->task_ctx; |
2243 | if (ctx->task) | |
2244 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2245 | |
fae3fde6 | 2246 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2247 | } |
2248 | ||
d859e29f | 2249 | /* |
cdd6c482 | 2250 | * Enable a event. |
c93f7669 | 2251 | * |
cdd6c482 IM |
2252 | * If event->ctx is a cloned context, callers must make sure that |
2253 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2254 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2255 | * perf_event_for_each_child or perf_event_for_each as described |
2256 | * for perf_event_disable. | |
d859e29f | 2257 | */ |
f63a8daa | 2258 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2259 | { |
cdd6c482 | 2260 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2261 | |
7b648018 | 2262 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2263 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2264 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2265 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2266 | return; |
2267 | } | |
2268 | ||
d859e29f | 2269 | /* |
cdd6c482 | 2270 | * If the event is in error state, clear that first. |
7b648018 PZ |
2271 | * |
2272 | * That way, if we see the event in error state below, we know that it | |
2273 | * has gone back into error state, as distinct from the task having | |
2274 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2275 | */ |
cdd6c482 IM |
2276 | if (event->state == PERF_EVENT_STATE_ERROR) |
2277 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2278 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2279 | |
fae3fde6 | 2280 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2281 | } |
f63a8daa PZ |
2282 | |
2283 | /* | |
2284 | * See perf_event_disable(); | |
2285 | */ | |
2286 | void perf_event_enable(struct perf_event *event) | |
2287 | { | |
2288 | struct perf_event_context *ctx; | |
2289 | ||
2290 | ctx = perf_event_ctx_lock(event); | |
2291 | _perf_event_enable(event); | |
2292 | perf_event_ctx_unlock(event, ctx); | |
2293 | } | |
dcfce4a0 | 2294 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2295 | |
f63a8daa | 2296 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2297 | { |
2023b359 | 2298 | /* |
cdd6c482 | 2299 | * not supported on inherited events |
2023b359 | 2300 | */ |
2e939d1d | 2301 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2302 | return -EINVAL; |
2303 | ||
cdd6c482 | 2304 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2305 | _perf_event_enable(event); |
2023b359 PZ |
2306 | |
2307 | return 0; | |
79f14641 | 2308 | } |
f63a8daa PZ |
2309 | |
2310 | /* | |
2311 | * See perf_event_disable() | |
2312 | */ | |
2313 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2314 | { | |
2315 | struct perf_event_context *ctx; | |
2316 | int ret; | |
2317 | ||
2318 | ctx = perf_event_ctx_lock(event); | |
2319 | ret = _perf_event_refresh(event, refresh); | |
2320 | perf_event_ctx_unlock(event, ctx); | |
2321 | ||
2322 | return ret; | |
2323 | } | |
26ca5c11 | 2324 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2325 | |
5b0311e1 FW |
2326 | static void ctx_sched_out(struct perf_event_context *ctx, |
2327 | struct perf_cpu_context *cpuctx, | |
2328 | enum event_type_t event_type) | |
235c7fc7 | 2329 | { |
db24d33e | 2330 | int is_active = ctx->is_active; |
c994d613 | 2331 | struct perf_event *event; |
235c7fc7 | 2332 | |
c994d613 | 2333 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2334 | |
39a43640 PZ |
2335 | if (likely(!ctx->nr_events)) { |
2336 | /* | |
2337 | * See __perf_remove_from_context(). | |
2338 | */ | |
2339 | WARN_ON_ONCE(ctx->is_active); | |
2340 | if (ctx->task) | |
2341 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2342 | return; |
39a43640 PZ |
2343 | } |
2344 | ||
db24d33e | 2345 | ctx->is_active &= ~event_type; |
63e30d3e PZ |
2346 | if (ctx->task) { |
2347 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2348 | if (!ctx->is_active) | |
2349 | cpuctx->task_ctx = NULL; | |
2350 | } | |
facc4307 | 2351 | |
4af4998b | 2352 | update_context_time(ctx); |
e5d1367f | 2353 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2354 | if (!ctx->nr_active) |
facc4307 | 2355 | return; |
5b0311e1 | 2356 | |
075e0b00 | 2357 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2358 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2359 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2360 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2361 | } |
889ff015 | 2362 | |
db24d33e | 2363 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2364 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2365 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2366 | } |
1b9a644f | 2367 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2368 | } |
2369 | ||
564c2b21 | 2370 | /* |
5a3126d4 PZ |
2371 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2372 | * cloned from the same version of the same context. | |
2373 | * | |
2374 | * Equivalence is measured using a generation number in the context that is | |
2375 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2376 | * and list_del_event(). | |
564c2b21 | 2377 | */ |
cdd6c482 IM |
2378 | static int context_equiv(struct perf_event_context *ctx1, |
2379 | struct perf_event_context *ctx2) | |
564c2b21 | 2380 | { |
211de6eb PZ |
2381 | lockdep_assert_held(&ctx1->lock); |
2382 | lockdep_assert_held(&ctx2->lock); | |
2383 | ||
5a3126d4 PZ |
2384 | /* Pinning disables the swap optimization */ |
2385 | if (ctx1->pin_count || ctx2->pin_count) | |
2386 | return 0; | |
2387 | ||
2388 | /* If ctx1 is the parent of ctx2 */ | |
2389 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2390 | return 1; | |
2391 | ||
2392 | /* If ctx2 is the parent of ctx1 */ | |
2393 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2394 | return 1; | |
2395 | ||
2396 | /* | |
2397 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2398 | * hierarchy, see perf_event_init_context(). | |
2399 | */ | |
2400 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2401 | ctx1->parent_gen == ctx2->parent_gen) | |
2402 | return 1; | |
2403 | ||
2404 | /* Unmatched */ | |
2405 | return 0; | |
564c2b21 PM |
2406 | } |
2407 | ||
cdd6c482 IM |
2408 | static void __perf_event_sync_stat(struct perf_event *event, |
2409 | struct perf_event *next_event) | |
bfbd3381 PZ |
2410 | { |
2411 | u64 value; | |
2412 | ||
cdd6c482 | 2413 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2414 | return; |
2415 | ||
2416 | /* | |
cdd6c482 | 2417 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2418 | * because we're in the middle of a context switch and have IRQs |
2419 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2420 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2421 | * don't need to use it. |
2422 | */ | |
cdd6c482 IM |
2423 | switch (event->state) { |
2424 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2425 | event->pmu->read(event); |
2426 | /* fall-through */ | |
bfbd3381 | 2427 | |
cdd6c482 IM |
2428 | case PERF_EVENT_STATE_INACTIVE: |
2429 | update_event_times(event); | |
bfbd3381 PZ |
2430 | break; |
2431 | ||
2432 | default: | |
2433 | break; | |
2434 | } | |
2435 | ||
2436 | /* | |
cdd6c482 | 2437 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2438 | * values when we flip the contexts. |
2439 | */ | |
e7850595 PZ |
2440 | value = local64_read(&next_event->count); |
2441 | value = local64_xchg(&event->count, value); | |
2442 | local64_set(&next_event->count, value); | |
bfbd3381 | 2443 | |
cdd6c482 IM |
2444 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2445 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2446 | |
bfbd3381 | 2447 | /* |
19d2e755 | 2448 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2449 | */ |
cdd6c482 IM |
2450 | perf_event_update_userpage(event); |
2451 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2452 | } |
2453 | ||
cdd6c482 IM |
2454 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2455 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2456 | { |
cdd6c482 | 2457 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2458 | |
2459 | if (!ctx->nr_stat) | |
2460 | return; | |
2461 | ||
02ffdbc8 PZ |
2462 | update_context_time(ctx); |
2463 | ||
cdd6c482 IM |
2464 | event = list_first_entry(&ctx->event_list, |
2465 | struct perf_event, event_entry); | |
bfbd3381 | 2466 | |
cdd6c482 IM |
2467 | next_event = list_first_entry(&next_ctx->event_list, |
2468 | struct perf_event, event_entry); | |
bfbd3381 | 2469 | |
cdd6c482 IM |
2470 | while (&event->event_entry != &ctx->event_list && |
2471 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2472 | |
cdd6c482 | 2473 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2474 | |
cdd6c482 IM |
2475 | event = list_next_entry(event, event_entry); |
2476 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2477 | } |
2478 | } | |
2479 | ||
fe4b04fa PZ |
2480 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2481 | struct task_struct *next) | |
0793a61d | 2482 | { |
8dc85d54 | 2483 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2484 | struct perf_event_context *next_ctx; |
5a3126d4 | 2485 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2486 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2487 | int do_switch = 1; |
0793a61d | 2488 | |
108b02cf PZ |
2489 | if (likely(!ctx)) |
2490 | return; | |
10989fb2 | 2491 | |
108b02cf PZ |
2492 | cpuctx = __get_cpu_context(ctx); |
2493 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2494 | return; |
2495 | ||
c93f7669 | 2496 | rcu_read_lock(); |
8dc85d54 | 2497 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2498 | if (!next_ctx) |
2499 | goto unlock; | |
2500 | ||
2501 | parent = rcu_dereference(ctx->parent_ctx); | |
2502 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2503 | ||
2504 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2505 | if (!parent && !next_parent) |
5a3126d4 PZ |
2506 | goto unlock; |
2507 | ||
2508 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2509 | /* |
2510 | * Looks like the two contexts are clones, so we might be | |
2511 | * able to optimize the context switch. We lock both | |
2512 | * contexts and check that they are clones under the | |
2513 | * lock (including re-checking that neither has been | |
2514 | * uncloned in the meantime). It doesn't matter which | |
2515 | * order we take the locks because no other cpu could | |
2516 | * be trying to lock both of these tasks. | |
2517 | */ | |
e625cce1 TG |
2518 | raw_spin_lock(&ctx->lock); |
2519 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2520 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2521 | WRITE_ONCE(ctx->task, next); |
2522 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2523 | |
2524 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2525 | ||
63b6da39 PZ |
2526 | /* |
2527 | * RCU_INIT_POINTER here is safe because we've not | |
2528 | * modified the ctx and the above modification of | |
2529 | * ctx->task and ctx->task_ctx_data are immaterial | |
2530 | * since those values are always verified under | |
2531 | * ctx->lock which we're now holding. | |
2532 | */ | |
2533 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2534 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2535 | ||
c93f7669 | 2536 | do_switch = 0; |
bfbd3381 | 2537 | |
cdd6c482 | 2538 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2539 | } |
e625cce1 TG |
2540 | raw_spin_unlock(&next_ctx->lock); |
2541 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2542 | } |
5a3126d4 | 2543 | unlock: |
c93f7669 | 2544 | rcu_read_unlock(); |
564c2b21 | 2545 | |
c93f7669 | 2546 | if (do_switch) { |
facc4307 | 2547 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2548 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2549 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2550 | } |
0793a61d TG |
2551 | } |
2552 | ||
ba532500 YZ |
2553 | void perf_sched_cb_dec(struct pmu *pmu) |
2554 | { | |
2555 | this_cpu_dec(perf_sched_cb_usages); | |
2556 | } | |
2557 | ||
2558 | void perf_sched_cb_inc(struct pmu *pmu) | |
2559 | { | |
2560 | this_cpu_inc(perf_sched_cb_usages); | |
2561 | } | |
2562 | ||
2563 | /* | |
2564 | * This function provides the context switch callback to the lower code | |
2565 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2566 | */ | |
2567 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2568 | struct task_struct *next, | |
2569 | bool sched_in) | |
2570 | { | |
2571 | struct perf_cpu_context *cpuctx; | |
2572 | struct pmu *pmu; | |
2573 | unsigned long flags; | |
2574 | ||
2575 | if (prev == next) | |
2576 | return; | |
2577 | ||
2578 | local_irq_save(flags); | |
2579 | ||
2580 | rcu_read_lock(); | |
2581 | ||
2582 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2583 | if (pmu->sched_task) { | |
2584 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2585 | ||
2586 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2587 | ||
2588 | perf_pmu_disable(pmu); | |
2589 | ||
2590 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2591 | ||
2592 | perf_pmu_enable(pmu); | |
2593 | ||
2594 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2595 | } | |
2596 | } | |
2597 | ||
2598 | rcu_read_unlock(); | |
2599 | ||
2600 | local_irq_restore(flags); | |
2601 | } | |
2602 | ||
45ac1403 AH |
2603 | static void perf_event_switch(struct task_struct *task, |
2604 | struct task_struct *next_prev, bool sched_in); | |
2605 | ||
8dc85d54 PZ |
2606 | #define for_each_task_context_nr(ctxn) \ |
2607 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2608 | ||
2609 | /* | |
2610 | * Called from scheduler to remove the events of the current task, | |
2611 | * with interrupts disabled. | |
2612 | * | |
2613 | * We stop each event and update the event value in event->count. | |
2614 | * | |
2615 | * This does not protect us against NMI, but disable() | |
2616 | * sets the disabled bit in the control field of event _before_ | |
2617 | * accessing the event control register. If a NMI hits, then it will | |
2618 | * not restart the event. | |
2619 | */ | |
ab0cce56 JO |
2620 | void __perf_event_task_sched_out(struct task_struct *task, |
2621 | struct task_struct *next) | |
8dc85d54 PZ |
2622 | { |
2623 | int ctxn; | |
2624 | ||
ba532500 YZ |
2625 | if (__this_cpu_read(perf_sched_cb_usages)) |
2626 | perf_pmu_sched_task(task, next, false); | |
2627 | ||
45ac1403 AH |
2628 | if (atomic_read(&nr_switch_events)) |
2629 | perf_event_switch(task, next, false); | |
2630 | ||
8dc85d54 PZ |
2631 | for_each_task_context_nr(ctxn) |
2632 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2633 | |
2634 | /* | |
2635 | * if cgroup events exist on this CPU, then we need | |
2636 | * to check if we have to switch out PMU state. | |
2637 | * cgroup event are system-wide mode only | |
2638 | */ | |
4a32fea9 | 2639 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2640 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2641 | } |
2642 | ||
3e349507 PZ |
2643 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2644 | struct perf_event_context *ctx) | |
a08b159f | 2645 | { |
a63eaf34 PM |
2646 | if (!cpuctx->task_ctx) |
2647 | return; | |
012b84da IM |
2648 | |
2649 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2650 | return; | |
2651 | ||
04dc2dbb | 2652 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2653 | } |
2654 | ||
5b0311e1 FW |
2655 | /* |
2656 | * Called with IRQs disabled | |
2657 | */ | |
2658 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2659 | enum event_type_t event_type) | |
2660 | { | |
2661 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2662 | } |
2663 | ||
235c7fc7 | 2664 | static void |
5b0311e1 | 2665 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2666 | struct perf_cpu_context *cpuctx) |
0793a61d | 2667 | { |
cdd6c482 | 2668 | struct perf_event *event; |
0793a61d | 2669 | |
889ff015 FW |
2670 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2671 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2672 | continue; |
5632ab12 | 2673 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2674 | continue; |
2675 | ||
e5d1367f SE |
2676 | /* may need to reset tstamp_enabled */ |
2677 | if (is_cgroup_event(event)) | |
2678 | perf_cgroup_mark_enabled(event, ctx); | |
2679 | ||
8c9ed8e1 | 2680 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2681 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2682 | |
2683 | /* | |
2684 | * If this pinned group hasn't been scheduled, | |
2685 | * put it in error state. | |
2686 | */ | |
cdd6c482 IM |
2687 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2688 | update_group_times(event); | |
2689 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2690 | } |
3b6f9e5c | 2691 | } |
5b0311e1 FW |
2692 | } |
2693 | ||
2694 | static void | |
2695 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2696 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2697 | { |
2698 | struct perf_event *event; | |
2699 | int can_add_hw = 1; | |
3b6f9e5c | 2700 | |
889ff015 FW |
2701 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2702 | /* Ignore events in OFF or ERROR state */ | |
2703 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2704 | continue; |
04289bb9 IM |
2705 | /* |
2706 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2707 | * of events: |
04289bb9 | 2708 | */ |
5632ab12 | 2709 | if (!event_filter_match(event)) |
0793a61d TG |
2710 | continue; |
2711 | ||
e5d1367f SE |
2712 | /* may need to reset tstamp_enabled */ |
2713 | if (is_cgroup_event(event)) | |
2714 | perf_cgroup_mark_enabled(event, ctx); | |
2715 | ||
9ed6060d | 2716 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2717 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2718 | can_add_hw = 0; |
9ed6060d | 2719 | } |
0793a61d | 2720 | } |
5b0311e1 FW |
2721 | } |
2722 | ||
2723 | static void | |
2724 | ctx_sched_in(struct perf_event_context *ctx, | |
2725 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2726 | enum event_type_t event_type, |
2727 | struct task_struct *task) | |
5b0311e1 | 2728 | { |
db24d33e | 2729 | int is_active = ctx->is_active; |
c994d613 PZ |
2730 | u64 now; |
2731 | ||
2732 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2733 | |
5b0311e1 | 2734 | if (likely(!ctx->nr_events)) |
facc4307 | 2735 | return; |
5b0311e1 | 2736 | |
db24d33e | 2737 | ctx->is_active |= event_type; |
63e30d3e PZ |
2738 | if (ctx->task) { |
2739 | if (!is_active) | |
2740 | cpuctx->task_ctx = ctx; | |
2741 | else | |
2742 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2743 | } | |
2744 | ||
e5d1367f SE |
2745 | now = perf_clock(); |
2746 | ctx->timestamp = now; | |
3f7cce3c | 2747 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2748 | /* |
2749 | * First go through the list and put on any pinned groups | |
2750 | * in order to give them the best chance of going on. | |
2751 | */ | |
db24d33e | 2752 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2753 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2754 | |
2755 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2756 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2757 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2758 | } |
2759 | ||
329c0e01 | 2760 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2761 | enum event_type_t event_type, |
2762 | struct task_struct *task) | |
329c0e01 FW |
2763 | { |
2764 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2765 | ||
e5d1367f | 2766 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2767 | } |
2768 | ||
e5d1367f SE |
2769 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2770 | struct task_struct *task) | |
235c7fc7 | 2771 | { |
108b02cf | 2772 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2773 | |
108b02cf | 2774 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2775 | if (cpuctx->task_ctx == ctx) |
2776 | return; | |
2777 | ||
facc4307 | 2778 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2779 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2780 | /* |
2781 | * We want to keep the following priority order: | |
2782 | * cpu pinned (that don't need to move), task pinned, | |
2783 | * cpu flexible, task flexible. | |
2784 | */ | |
2785 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2786 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2787 | perf_pmu_enable(ctx->pmu); |
2788 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2789 | } |
2790 | ||
8dc85d54 PZ |
2791 | /* |
2792 | * Called from scheduler to add the events of the current task | |
2793 | * with interrupts disabled. | |
2794 | * | |
2795 | * We restore the event value and then enable it. | |
2796 | * | |
2797 | * This does not protect us against NMI, but enable() | |
2798 | * sets the enabled bit in the control field of event _before_ | |
2799 | * accessing the event control register. If a NMI hits, then it will | |
2800 | * keep the event running. | |
2801 | */ | |
ab0cce56 JO |
2802 | void __perf_event_task_sched_in(struct task_struct *prev, |
2803 | struct task_struct *task) | |
8dc85d54 PZ |
2804 | { |
2805 | struct perf_event_context *ctx; | |
2806 | int ctxn; | |
2807 | ||
7e41d177 PZ |
2808 | /* |
2809 | * If cgroup events exist on this CPU, then we need to check if we have | |
2810 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2811 | * | |
2812 | * Since cgroup events are CPU events, we must schedule these in before | |
2813 | * we schedule in the task events. | |
2814 | */ | |
2815 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2816 | perf_cgroup_sched_in(prev, task); | |
2817 | ||
8dc85d54 PZ |
2818 | for_each_task_context_nr(ctxn) { |
2819 | ctx = task->perf_event_ctxp[ctxn]; | |
2820 | if (likely(!ctx)) | |
2821 | continue; | |
2822 | ||
e5d1367f | 2823 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2824 | } |
d010b332 | 2825 | |
45ac1403 AH |
2826 | if (atomic_read(&nr_switch_events)) |
2827 | perf_event_switch(task, prev, true); | |
2828 | ||
ba532500 YZ |
2829 | if (__this_cpu_read(perf_sched_cb_usages)) |
2830 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2831 | } |
2832 | ||
abd50713 PZ |
2833 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2834 | { | |
2835 | u64 frequency = event->attr.sample_freq; | |
2836 | u64 sec = NSEC_PER_SEC; | |
2837 | u64 divisor, dividend; | |
2838 | ||
2839 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2840 | ||
2841 | count_fls = fls64(count); | |
2842 | nsec_fls = fls64(nsec); | |
2843 | frequency_fls = fls64(frequency); | |
2844 | sec_fls = 30; | |
2845 | ||
2846 | /* | |
2847 | * We got @count in @nsec, with a target of sample_freq HZ | |
2848 | * the target period becomes: | |
2849 | * | |
2850 | * @count * 10^9 | |
2851 | * period = ------------------- | |
2852 | * @nsec * sample_freq | |
2853 | * | |
2854 | */ | |
2855 | ||
2856 | /* | |
2857 | * Reduce accuracy by one bit such that @a and @b converge | |
2858 | * to a similar magnitude. | |
2859 | */ | |
fe4b04fa | 2860 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2861 | do { \ |
2862 | if (a##_fls > b##_fls) { \ | |
2863 | a >>= 1; \ | |
2864 | a##_fls--; \ | |
2865 | } else { \ | |
2866 | b >>= 1; \ | |
2867 | b##_fls--; \ | |
2868 | } \ | |
2869 | } while (0) | |
2870 | ||
2871 | /* | |
2872 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2873 | * the other, so that finally we can do a u64/u64 division. | |
2874 | */ | |
2875 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2876 | REDUCE_FLS(nsec, frequency); | |
2877 | REDUCE_FLS(sec, count); | |
2878 | } | |
2879 | ||
2880 | if (count_fls + sec_fls > 64) { | |
2881 | divisor = nsec * frequency; | |
2882 | ||
2883 | while (count_fls + sec_fls > 64) { | |
2884 | REDUCE_FLS(count, sec); | |
2885 | divisor >>= 1; | |
2886 | } | |
2887 | ||
2888 | dividend = count * sec; | |
2889 | } else { | |
2890 | dividend = count * sec; | |
2891 | ||
2892 | while (nsec_fls + frequency_fls > 64) { | |
2893 | REDUCE_FLS(nsec, frequency); | |
2894 | dividend >>= 1; | |
2895 | } | |
2896 | ||
2897 | divisor = nsec * frequency; | |
2898 | } | |
2899 | ||
f6ab91ad PZ |
2900 | if (!divisor) |
2901 | return dividend; | |
2902 | ||
abd50713 PZ |
2903 | return div64_u64(dividend, divisor); |
2904 | } | |
2905 | ||
e050e3f0 SE |
2906 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2907 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2908 | ||
f39d47ff | 2909 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2910 | { |
cdd6c482 | 2911 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2912 | s64 period, sample_period; |
bd2b5b12 PZ |
2913 | s64 delta; |
2914 | ||
abd50713 | 2915 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2916 | |
2917 | delta = (s64)(period - hwc->sample_period); | |
2918 | delta = (delta + 7) / 8; /* low pass filter */ | |
2919 | ||
2920 | sample_period = hwc->sample_period + delta; | |
2921 | ||
2922 | if (!sample_period) | |
2923 | sample_period = 1; | |
2924 | ||
bd2b5b12 | 2925 | hwc->sample_period = sample_period; |
abd50713 | 2926 | |
e7850595 | 2927 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2928 | if (disable) |
2929 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2930 | ||
e7850595 | 2931 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2932 | |
2933 | if (disable) | |
2934 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2935 | } |
bd2b5b12 PZ |
2936 | } |
2937 | ||
e050e3f0 SE |
2938 | /* |
2939 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2940 | * events. At the same time, make sure, having freq events does not change | |
2941 | * the rate of unthrottling as that would introduce bias. | |
2942 | */ | |
2943 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2944 | int needs_unthr) | |
60db5e09 | 2945 | { |
cdd6c482 IM |
2946 | struct perf_event *event; |
2947 | struct hw_perf_event *hwc; | |
e050e3f0 | 2948 | u64 now, period = TICK_NSEC; |
abd50713 | 2949 | s64 delta; |
60db5e09 | 2950 | |
e050e3f0 SE |
2951 | /* |
2952 | * only need to iterate over all events iff: | |
2953 | * - context have events in frequency mode (needs freq adjust) | |
2954 | * - there are events to unthrottle on this cpu | |
2955 | */ | |
2956 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2957 | return; |
2958 | ||
e050e3f0 | 2959 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2960 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2961 | |
03541f8b | 2962 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2963 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2964 | continue; |
2965 | ||
5632ab12 | 2966 | if (!event_filter_match(event)) |
5d27c23d PZ |
2967 | continue; |
2968 | ||
44377277 AS |
2969 | perf_pmu_disable(event->pmu); |
2970 | ||
cdd6c482 | 2971 | hwc = &event->hw; |
6a24ed6c | 2972 | |
ae23bff1 | 2973 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2974 | hwc->interrupts = 0; |
cdd6c482 | 2975 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2976 | event->pmu->start(event, 0); |
a78ac325 PZ |
2977 | } |
2978 | ||
cdd6c482 | 2979 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2980 | goto next; |
60db5e09 | 2981 | |
e050e3f0 SE |
2982 | /* |
2983 | * stop the event and update event->count | |
2984 | */ | |
2985 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2986 | ||
e7850595 | 2987 | now = local64_read(&event->count); |
abd50713 PZ |
2988 | delta = now - hwc->freq_count_stamp; |
2989 | hwc->freq_count_stamp = now; | |
60db5e09 | 2990 | |
e050e3f0 SE |
2991 | /* |
2992 | * restart the event | |
2993 | * reload only if value has changed | |
f39d47ff SE |
2994 | * we have stopped the event so tell that |
2995 | * to perf_adjust_period() to avoid stopping it | |
2996 | * twice. | |
e050e3f0 | 2997 | */ |
abd50713 | 2998 | if (delta > 0) |
f39d47ff | 2999 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3000 | |
3001 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3002 | next: |
3003 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3004 | } |
e050e3f0 | 3005 | |
f39d47ff | 3006 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3007 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3008 | } |
3009 | ||
235c7fc7 | 3010 | /* |
cdd6c482 | 3011 | * Round-robin a context's events: |
235c7fc7 | 3012 | */ |
cdd6c482 | 3013 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3014 | { |
dddd3379 TG |
3015 | /* |
3016 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3017 | * disabled by the inheritance code. | |
3018 | */ | |
3019 | if (!ctx->rotate_disable) | |
3020 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3021 | } |
3022 | ||
9e630205 | 3023 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3024 | { |
8dc85d54 | 3025 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3026 | int rotate = 0; |
7fc23a53 | 3027 | |
b5ab4cd5 | 3028 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3029 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3030 | rotate = 1; | |
3031 | } | |
235c7fc7 | 3032 | |
8dc85d54 | 3033 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3034 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3035 | if (ctx->nr_events != ctx->nr_active) |
3036 | rotate = 1; | |
3037 | } | |
9717e6cd | 3038 | |
e050e3f0 | 3039 | if (!rotate) |
0f5a2601 PZ |
3040 | goto done; |
3041 | ||
facc4307 | 3042 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3043 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3044 | |
e050e3f0 SE |
3045 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3046 | if (ctx) | |
3047 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3048 | |
e050e3f0 SE |
3049 | rotate_ctx(&cpuctx->ctx); |
3050 | if (ctx) | |
3051 | rotate_ctx(ctx); | |
235c7fc7 | 3052 | |
e050e3f0 | 3053 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3054 | |
0f5a2601 PZ |
3055 | perf_pmu_enable(cpuctx->ctx.pmu); |
3056 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3057 | done: |
9e630205 SE |
3058 | |
3059 | return rotate; | |
e9d2b064 PZ |
3060 | } |
3061 | ||
026249ef FW |
3062 | #ifdef CONFIG_NO_HZ_FULL |
3063 | bool perf_event_can_stop_tick(void) | |
3064 | { | |
948b26b6 | 3065 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3066 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3067 | return false; |
d84153d6 FW |
3068 | else |
3069 | return true; | |
026249ef FW |
3070 | } |
3071 | #endif | |
3072 | ||
e9d2b064 PZ |
3073 | void perf_event_task_tick(void) |
3074 | { | |
2fde4f94 MR |
3075 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3076 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3077 | int throttled; |
b5ab4cd5 | 3078 | |
e9d2b064 PZ |
3079 | WARN_ON(!irqs_disabled()); |
3080 | ||
e050e3f0 SE |
3081 | __this_cpu_inc(perf_throttled_seq); |
3082 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3083 | ||
2fde4f94 | 3084 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3085 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3086 | } |
3087 | ||
889ff015 FW |
3088 | static int event_enable_on_exec(struct perf_event *event, |
3089 | struct perf_event_context *ctx) | |
3090 | { | |
3091 | if (!event->attr.enable_on_exec) | |
3092 | return 0; | |
3093 | ||
3094 | event->attr.enable_on_exec = 0; | |
3095 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3096 | return 0; | |
3097 | ||
1d9b482e | 3098 | __perf_event_mark_enabled(event); |
889ff015 FW |
3099 | |
3100 | return 1; | |
3101 | } | |
3102 | ||
57e7986e | 3103 | /* |
cdd6c482 | 3104 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3105 | * This expects task == current. |
3106 | */ | |
c1274499 | 3107 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3108 | { |
c1274499 | 3109 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3110 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3111 | struct perf_event *event; |
57e7986e PM |
3112 | unsigned long flags; |
3113 | int enabled = 0; | |
3114 | ||
3115 | local_irq_save(flags); | |
c1274499 | 3116 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3117 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3118 | goto out; |
3119 | ||
3e349507 PZ |
3120 | cpuctx = __get_cpu_context(ctx); |
3121 | perf_ctx_lock(cpuctx, ctx); | |
3122 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3123 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3124 | |
3125 | /* | |
3e349507 | 3126 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3127 | */ |
3e349507 | 3128 | if (enabled) { |
211de6eb | 3129 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3130 | ctx_resched(cpuctx, ctx); |
3131 | } | |
3132 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3133 | |
9ed6060d | 3134 | out: |
57e7986e | 3135 | local_irq_restore(flags); |
211de6eb PZ |
3136 | |
3137 | if (clone_ctx) | |
3138 | put_ctx(clone_ctx); | |
57e7986e PM |
3139 | } |
3140 | ||
e041e328 PZ |
3141 | void perf_event_exec(void) |
3142 | { | |
e041e328 PZ |
3143 | int ctxn; |
3144 | ||
3145 | rcu_read_lock(); | |
c1274499 PZ |
3146 | for_each_task_context_nr(ctxn) |
3147 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3148 | rcu_read_unlock(); |
3149 | } | |
3150 | ||
0492d4c5 PZ |
3151 | struct perf_read_data { |
3152 | struct perf_event *event; | |
3153 | bool group; | |
7d88962e | 3154 | int ret; |
0492d4c5 PZ |
3155 | }; |
3156 | ||
0793a61d | 3157 | /* |
cdd6c482 | 3158 | * Cross CPU call to read the hardware event |
0793a61d | 3159 | */ |
cdd6c482 | 3160 | static void __perf_event_read(void *info) |
0793a61d | 3161 | { |
0492d4c5 PZ |
3162 | struct perf_read_data *data = info; |
3163 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3164 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3165 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3166 | struct pmu *pmu = event->pmu; |
621a01ea | 3167 | |
e1ac3614 PM |
3168 | /* |
3169 | * If this is a task context, we need to check whether it is | |
3170 | * the current task context of this cpu. If not it has been | |
3171 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3172 | * event->count would have been updated to a recent sample |
3173 | * when the event was scheduled out. | |
e1ac3614 PM |
3174 | */ |
3175 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3176 | return; | |
3177 | ||
e625cce1 | 3178 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3179 | if (ctx->is_active) { |
542e72fc | 3180 | update_context_time(ctx); |
e5d1367f SE |
3181 | update_cgrp_time_from_event(event); |
3182 | } | |
0492d4c5 | 3183 | |
cdd6c482 | 3184 | update_event_times(event); |
4a00c16e SB |
3185 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3186 | goto unlock; | |
0492d4c5 | 3187 | |
4a00c16e SB |
3188 | if (!data->group) { |
3189 | pmu->read(event); | |
3190 | data->ret = 0; | |
0492d4c5 | 3191 | goto unlock; |
4a00c16e SB |
3192 | } |
3193 | ||
3194 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3195 | ||
3196 | pmu->read(event); | |
0492d4c5 PZ |
3197 | |
3198 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3199 | update_event_times(sub); | |
4a00c16e SB |
3200 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3201 | /* | |
3202 | * Use sibling's PMU rather than @event's since | |
3203 | * sibling could be on different (eg: software) PMU. | |
3204 | */ | |
0492d4c5 | 3205 | sub->pmu->read(sub); |
4a00c16e | 3206 | } |
0492d4c5 | 3207 | } |
4a00c16e SB |
3208 | |
3209 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3210 | |
3211 | unlock: | |
e625cce1 | 3212 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3213 | } |
3214 | ||
b5e58793 PZ |
3215 | static inline u64 perf_event_count(struct perf_event *event) |
3216 | { | |
eacd3ecc MF |
3217 | if (event->pmu->count) |
3218 | return event->pmu->count(event); | |
3219 | ||
3220 | return __perf_event_count(event); | |
b5e58793 PZ |
3221 | } |
3222 | ||
ffe8690c KX |
3223 | /* |
3224 | * NMI-safe method to read a local event, that is an event that | |
3225 | * is: | |
3226 | * - either for the current task, or for this CPU | |
3227 | * - does not have inherit set, for inherited task events | |
3228 | * will not be local and we cannot read them atomically | |
3229 | * - must not have a pmu::count method | |
3230 | */ | |
3231 | u64 perf_event_read_local(struct perf_event *event) | |
3232 | { | |
3233 | unsigned long flags; | |
3234 | u64 val; | |
3235 | ||
3236 | /* | |
3237 | * Disabling interrupts avoids all counter scheduling (context | |
3238 | * switches, timer based rotation and IPIs). | |
3239 | */ | |
3240 | local_irq_save(flags); | |
3241 | ||
3242 | /* If this is a per-task event, it must be for current */ | |
3243 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3244 | event->hw.target != current); | |
3245 | ||
3246 | /* If this is a per-CPU event, it must be for this CPU */ | |
3247 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3248 | event->cpu != smp_processor_id()); | |
3249 | ||
3250 | /* | |
3251 | * It must not be an event with inherit set, we cannot read | |
3252 | * all child counters from atomic context. | |
3253 | */ | |
3254 | WARN_ON_ONCE(event->attr.inherit); | |
3255 | ||
3256 | /* | |
3257 | * It must not have a pmu::count method, those are not | |
3258 | * NMI safe. | |
3259 | */ | |
3260 | WARN_ON_ONCE(event->pmu->count); | |
3261 | ||
3262 | /* | |
3263 | * If the event is currently on this CPU, its either a per-task event, | |
3264 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3265 | * oncpu == -1). | |
3266 | */ | |
3267 | if (event->oncpu == smp_processor_id()) | |
3268 | event->pmu->read(event); | |
3269 | ||
3270 | val = local64_read(&event->count); | |
3271 | local_irq_restore(flags); | |
3272 | ||
3273 | return val; | |
3274 | } | |
3275 | ||
7d88962e | 3276 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3277 | { |
7d88962e SB |
3278 | int ret = 0; |
3279 | ||
0793a61d | 3280 | /* |
cdd6c482 IM |
3281 | * If event is enabled and currently active on a CPU, update the |
3282 | * value in the event structure: | |
0793a61d | 3283 | */ |
cdd6c482 | 3284 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3285 | struct perf_read_data data = { |
3286 | .event = event, | |
3287 | .group = group, | |
7d88962e | 3288 | .ret = 0, |
0492d4c5 | 3289 | }; |
cdd6c482 | 3290 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3291 | __perf_event_read, &data, 1); |
7d88962e | 3292 | ret = data.ret; |
cdd6c482 | 3293 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3294 | struct perf_event_context *ctx = event->ctx; |
3295 | unsigned long flags; | |
3296 | ||
e625cce1 | 3297 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3298 | /* |
3299 | * may read while context is not active | |
3300 | * (e.g., thread is blocked), in that case | |
3301 | * we cannot update context time | |
3302 | */ | |
e5d1367f | 3303 | if (ctx->is_active) { |
c530ccd9 | 3304 | update_context_time(ctx); |
e5d1367f SE |
3305 | update_cgrp_time_from_event(event); |
3306 | } | |
0492d4c5 PZ |
3307 | if (group) |
3308 | update_group_times(event); | |
3309 | else | |
3310 | update_event_times(event); | |
e625cce1 | 3311 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3312 | } |
7d88962e SB |
3313 | |
3314 | return ret; | |
0793a61d TG |
3315 | } |
3316 | ||
a63eaf34 | 3317 | /* |
cdd6c482 | 3318 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3319 | */ |
eb184479 | 3320 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3321 | { |
e625cce1 | 3322 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3323 | mutex_init(&ctx->mutex); |
2fde4f94 | 3324 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3325 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3326 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3327 | INIT_LIST_HEAD(&ctx->event_list); |
3328 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3329 | } |
3330 | ||
3331 | static struct perf_event_context * | |
3332 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3333 | { | |
3334 | struct perf_event_context *ctx; | |
3335 | ||
3336 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3337 | if (!ctx) | |
3338 | return NULL; | |
3339 | ||
3340 | __perf_event_init_context(ctx); | |
3341 | if (task) { | |
3342 | ctx->task = task; | |
3343 | get_task_struct(task); | |
0793a61d | 3344 | } |
eb184479 PZ |
3345 | ctx->pmu = pmu; |
3346 | ||
3347 | return ctx; | |
a63eaf34 PM |
3348 | } |
3349 | ||
2ebd4ffb MH |
3350 | static struct task_struct * |
3351 | find_lively_task_by_vpid(pid_t vpid) | |
3352 | { | |
3353 | struct task_struct *task; | |
3354 | int err; | |
0793a61d TG |
3355 | |
3356 | rcu_read_lock(); | |
2ebd4ffb | 3357 | if (!vpid) |
0793a61d TG |
3358 | task = current; |
3359 | else | |
2ebd4ffb | 3360 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3361 | if (task) |
3362 | get_task_struct(task); | |
3363 | rcu_read_unlock(); | |
3364 | ||
3365 | if (!task) | |
3366 | return ERR_PTR(-ESRCH); | |
3367 | ||
0793a61d | 3368 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3369 | err = -EACCES; |
caaee623 | 3370 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3371 | goto errout; |
3372 | ||
2ebd4ffb MH |
3373 | return task; |
3374 | errout: | |
3375 | put_task_struct(task); | |
3376 | return ERR_PTR(err); | |
3377 | ||
3378 | } | |
3379 | ||
fe4b04fa PZ |
3380 | /* |
3381 | * Returns a matching context with refcount and pincount. | |
3382 | */ | |
108b02cf | 3383 | static struct perf_event_context * |
4af57ef2 YZ |
3384 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3385 | struct perf_event *event) | |
0793a61d | 3386 | { |
211de6eb | 3387 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3388 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3389 | void *task_ctx_data = NULL; |
25346b93 | 3390 | unsigned long flags; |
8dc85d54 | 3391 | int ctxn, err; |
4af57ef2 | 3392 | int cpu = event->cpu; |
0793a61d | 3393 | |
22a4ec72 | 3394 | if (!task) { |
cdd6c482 | 3395 | /* Must be root to operate on a CPU event: */ |
0764771d | 3396 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3397 | return ERR_PTR(-EACCES); |
3398 | ||
0793a61d | 3399 | /* |
cdd6c482 | 3400 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3401 | * offline CPU and activate it when the CPU comes up, but |
3402 | * that's for later. | |
3403 | */ | |
f6325e30 | 3404 | if (!cpu_online(cpu)) |
0793a61d TG |
3405 | return ERR_PTR(-ENODEV); |
3406 | ||
108b02cf | 3407 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3408 | ctx = &cpuctx->ctx; |
c93f7669 | 3409 | get_ctx(ctx); |
fe4b04fa | 3410 | ++ctx->pin_count; |
0793a61d | 3411 | |
0793a61d TG |
3412 | return ctx; |
3413 | } | |
3414 | ||
8dc85d54 PZ |
3415 | err = -EINVAL; |
3416 | ctxn = pmu->task_ctx_nr; | |
3417 | if (ctxn < 0) | |
3418 | goto errout; | |
3419 | ||
4af57ef2 YZ |
3420 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3421 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3422 | if (!task_ctx_data) { | |
3423 | err = -ENOMEM; | |
3424 | goto errout; | |
3425 | } | |
3426 | } | |
3427 | ||
9ed6060d | 3428 | retry: |
8dc85d54 | 3429 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3430 | if (ctx) { |
211de6eb | 3431 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3432 | ++ctx->pin_count; |
4af57ef2 YZ |
3433 | |
3434 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3435 | ctx->task_ctx_data = task_ctx_data; | |
3436 | task_ctx_data = NULL; | |
3437 | } | |
e625cce1 | 3438 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3439 | |
3440 | if (clone_ctx) | |
3441 | put_ctx(clone_ctx); | |
9137fb28 | 3442 | } else { |
eb184479 | 3443 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3444 | err = -ENOMEM; |
3445 | if (!ctx) | |
3446 | goto errout; | |
eb184479 | 3447 | |
4af57ef2 YZ |
3448 | if (task_ctx_data) { |
3449 | ctx->task_ctx_data = task_ctx_data; | |
3450 | task_ctx_data = NULL; | |
3451 | } | |
3452 | ||
dbe08d82 ON |
3453 | err = 0; |
3454 | mutex_lock(&task->perf_event_mutex); | |
3455 | /* | |
3456 | * If it has already passed perf_event_exit_task(). | |
3457 | * we must see PF_EXITING, it takes this mutex too. | |
3458 | */ | |
3459 | if (task->flags & PF_EXITING) | |
3460 | err = -ESRCH; | |
3461 | else if (task->perf_event_ctxp[ctxn]) | |
3462 | err = -EAGAIN; | |
fe4b04fa | 3463 | else { |
9137fb28 | 3464 | get_ctx(ctx); |
fe4b04fa | 3465 | ++ctx->pin_count; |
dbe08d82 | 3466 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3467 | } |
dbe08d82 ON |
3468 | mutex_unlock(&task->perf_event_mutex); |
3469 | ||
3470 | if (unlikely(err)) { | |
9137fb28 | 3471 | put_ctx(ctx); |
dbe08d82 ON |
3472 | |
3473 | if (err == -EAGAIN) | |
3474 | goto retry; | |
3475 | goto errout; | |
a63eaf34 PM |
3476 | } |
3477 | } | |
3478 | ||
4af57ef2 | 3479 | kfree(task_ctx_data); |
0793a61d | 3480 | return ctx; |
c93f7669 | 3481 | |
9ed6060d | 3482 | errout: |
4af57ef2 | 3483 | kfree(task_ctx_data); |
c93f7669 | 3484 | return ERR_PTR(err); |
0793a61d TG |
3485 | } |
3486 | ||
6fb2915d | 3487 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3488 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3489 | |
cdd6c482 | 3490 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3491 | { |
cdd6c482 | 3492 | struct perf_event *event; |
592903cd | 3493 | |
cdd6c482 IM |
3494 | event = container_of(head, struct perf_event, rcu_head); |
3495 | if (event->ns) | |
3496 | put_pid_ns(event->ns); | |
6fb2915d | 3497 | perf_event_free_filter(event); |
cdd6c482 | 3498 | kfree(event); |
592903cd PZ |
3499 | } |
3500 | ||
b69cf536 PZ |
3501 | static void ring_buffer_attach(struct perf_event *event, |
3502 | struct ring_buffer *rb); | |
925d519a | 3503 | |
4beb31f3 | 3504 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3505 | { |
4beb31f3 FW |
3506 | if (event->parent) |
3507 | return; | |
3508 | ||
4beb31f3 FW |
3509 | if (is_cgroup_event(event)) |
3510 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3511 | } | |
925d519a | 3512 | |
4beb31f3 FW |
3513 | static void unaccount_event(struct perf_event *event) |
3514 | { | |
25432ae9 PZ |
3515 | bool dec = false; |
3516 | ||
4beb31f3 FW |
3517 | if (event->parent) |
3518 | return; | |
3519 | ||
3520 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3521 | dec = true; |
4beb31f3 FW |
3522 | if (event->attr.mmap || event->attr.mmap_data) |
3523 | atomic_dec(&nr_mmap_events); | |
3524 | if (event->attr.comm) | |
3525 | atomic_dec(&nr_comm_events); | |
3526 | if (event->attr.task) | |
3527 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3528 | if (event->attr.freq) |
3529 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3530 | if (event->attr.context_switch) { |
25432ae9 | 3531 | dec = true; |
45ac1403 AH |
3532 | atomic_dec(&nr_switch_events); |
3533 | } | |
4beb31f3 | 3534 | if (is_cgroup_event(event)) |
25432ae9 | 3535 | dec = true; |
4beb31f3 | 3536 | if (has_branch_stack(event)) |
25432ae9 PZ |
3537 | dec = true; |
3538 | ||
3539 | if (dec) | |
4beb31f3 FW |
3540 | static_key_slow_dec_deferred(&perf_sched_events); |
3541 | ||
3542 | unaccount_event_cpu(event, event->cpu); | |
3543 | } | |
925d519a | 3544 | |
bed5b25a AS |
3545 | /* |
3546 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3547 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3548 | * at a time, so we disallow creating events that might conflict, namely: | |
3549 | * | |
3550 | * 1) cpu-wide events in the presence of per-task events, | |
3551 | * 2) per-task events in the presence of cpu-wide events, | |
3552 | * 3) two matching events on the same context. | |
3553 | * | |
3554 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3555 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3556 | */ |
3557 | static int exclusive_event_init(struct perf_event *event) | |
3558 | { | |
3559 | struct pmu *pmu = event->pmu; | |
3560 | ||
3561 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3562 | return 0; | |
3563 | ||
3564 | /* | |
3565 | * Prevent co-existence of per-task and cpu-wide events on the | |
3566 | * same exclusive pmu. | |
3567 | * | |
3568 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3569 | * events on this "exclusive" pmu, positive means there are | |
3570 | * per-task events. | |
3571 | * | |
3572 | * Since this is called in perf_event_alloc() path, event::ctx | |
3573 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3574 | * to mean "per-task event", because unlike other attach states it | |
3575 | * never gets cleared. | |
3576 | */ | |
3577 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3578 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3579 | return -EBUSY; | |
3580 | } else { | |
3581 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3582 | return -EBUSY; | |
3583 | } | |
3584 | ||
3585 | return 0; | |
3586 | } | |
3587 | ||
3588 | static void exclusive_event_destroy(struct perf_event *event) | |
3589 | { | |
3590 | struct pmu *pmu = event->pmu; | |
3591 | ||
3592 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3593 | return; | |
3594 | ||
3595 | /* see comment in exclusive_event_init() */ | |
3596 | if (event->attach_state & PERF_ATTACH_TASK) | |
3597 | atomic_dec(&pmu->exclusive_cnt); | |
3598 | else | |
3599 | atomic_inc(&pmu->exclusive_cnt); | |
3600 | } | |
3601 | ||
3602 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3603 | { | |
3604 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3605 | (e1->cpu == e2->cpu || | |
3606 | e1->cpu == -1 || | |
3607 | e2->cpu == -1)) | |
3608 | return true; | |
3609 | return false; | |
3610 | } | |
3611 | ||
3612 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3613 | static bool exclusive_event_installable(struct perf_event *event, | |
3614 | struct perf_event_context *ctx) | |
3615 | { | |
3616 | struct perf_event *iter_event; | |
3617 | struct pmu *pmu = event->pmu; | |
3618 | ||
3619 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3620 | return true; | |
3621 | ||
3622 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3623 | if (exclusive_event_match(iter_event, event)) | |
3624 | return false; | |
3625 | } | |
3626 | ||
3627 | return true; | |
3628 | } | |
3629 | ||
683ede43 | 3630 | static void _free_event(struct perf_event *event) |
f1600952 | 3631 | { |
e360adbe | 3632 | irq_work_sync(&event->pending); |
925d519a | 3633 | |
4beb31f3 | 3634 | unaccount_event(event); |
9ee318a7 | 3635 | |
76369139 | 3636 | if (event->rb) { |
9bb5d40c PZ |
3637 | /* |
3638 | * Can happen when we close an event with re-directed output. | |
3639 | * | |
3640 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3641 | * over us; possibly making our ring_buffer_put() the last. | |
3642 | */ | |
3643 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3644 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3645 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3646 | } |
3647 | ||
e5d1367f SE |
3648 | if (is_cgroup_event(event)) |
3649 | perf_detach_cgroup(event); | |
3650 | ||
a0733e69 PZ |
3651 | if (!event->parent) { |
3652 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3653 | put_callchain_buffers(); | |
3654 | } | |
3655 | ||
3656 | perf_event_free_bpf_prog(event); | |
3657 | ||
3658 | if (event->destroy) | |
3659 | event->destroy(event); | |
3660 | ||
3661 | if (event->ctx) | |
3662 | put_ctx(event->ctx); | |
3663 | ||
3664 | if (event->pmu) { | |
3665 | exclusive_event_destroy(event); | |
3666 | module_put(event->pmu->module); | |
3667 | } | |
3668 | ||
3669 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3670 | } |
3671 | ||
683ede43 PZ |
3672 | /* |
3673 | * Used to free events which have a known refcount of 1, such as in error paths | |
3674 | * where the event isn't exposed yet and inherited events. | |
3675 | */ | |
3676 | static void free_event(struct perf_event *event) | |
0793a61d | 3677 | { |
683ede43 PZ |
3678 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3679 | "unexpected event refcount: %ld; ptr=%p\n", | |
3680 | atomic_long_read(&event->refcount), event)) { | |
3681 | /* leak to avoid use-after-free */ | |
3682 | return; | |
3683 | } | |
0793a61d | 3684 | |
683ede43 | 3685 | _free_event(event); |
0793a61d TG |
3686 | } |
3687 | ||
a66a3052 | 3688 | /* |
f8697762 | 3689 | * Remove user event from the owner task. |
a66a3052 | 3690 | */ |
f8697762 | 3691 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3692 | { |
8882135b | 3693 | struct task_struct *owner; |
fb0459d7 | 3694 | |
8882135b | 3695 | rcu_read_lock(); |
8882135b | 3696 | /* |
f47c02c0 PZ |
3697 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3698 | * observe !owner it means the list deletion is complete and we can | |
3699 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3700 | * owner->perf_event_mutex. |
3701 | */ | |
f47c02c0 | 3702 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3703 | if (owner) { |
3704 | /* | |
3705 | * Since delayed_put_task_struct() also drops the last | |
3706 | * task reference we can safely take a new reference | |
3707 | * while holding the rcu_read_lock(). | |
3708 | */ | |
3709 | get_task_struct(owner); | |
3710 | } | |
3711 | rcu_read_unlock(); | |
3712 | ||
3713 | if (owner) { | |
f63a8daa PZ |
3714 | /* |
3715 | * If we're here through perf_event_exit_task() we're already | |
3716 | * holding ctx->mutex which would be an inversion wrt. the | |
3717 | * normal lock order. | |
3718 | * | |
3719 | * However we can safely take this lock because its the child | |
3720 | * ctx->mutex. | |
3721 | */ | |
3722 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3723 | ||
8882135b PZ |
3724 | /* |
3725 | * We have to re-check the event->owner field, if it is cleared | |
3726 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3727 | * ensured they're done, and we can proceed with freeing the | |
3728 | * event. | |
3729 | */ | |
f47c02c0 | 3730 | if (event->owner) { |
8882135b | 3731 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3732 | smp_store_release(&event->owner, NULL); |
3733 | } | |
8882135b PZ |
3734 | mutex_unlock(&owner->perf_event_mutex); |
3735 | put_task_struct(owner); | |
3736 | } | |
f8697762 JO |
3737 | } |
3738 | ||
f8697762 JO |
3739 | static void put_event(struct perf_event *event) |
3740 | { | |
f8697762 JO |
3741 | if (!atomic_long_dec_and_test(&event->refcount)) |
3742 | return; | |
3743 | ||
c6e5b732 PZ |
3744 | _free_event(event); |
3745 | } | |
3746 | ||
3747 | /* | |
3748 | * Kill an event dead; while event:refcount will preserve the event | |
3749 | * object, it will not preserve its functionality. Once the last 'user' | |
3750 | * gives up the object, we'll destroy the thing. | |
3751 | */ | |
3752 | int perf_event_release_kernel(struct perf_event *event) | |
3753 | { | |
a4f4bb6d | 3754 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
3755 | struct perf_event *child, *tmp; |
3756 | ||
a4f4bb6d PZ |
3757 | /* |
3758 | * If we got here through err_file: fput(event_file); we will not have | |
3759 | * attached to a context yet. | |
3760 | */ | |
3761 | if (!ctx) { | |
3762 | WARN_ON_ONCE(event->attach_state & | |
3763 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
3764 | goto no_ctx; | |
3765 | } | |
3766 | ||
f8697762 JO |
3767 | if (!is_kernel_event(event)) |
3768 | perf_remove_from_owner(event); | |
8882135b | 3769 | |
5fa7c8ec | 3770 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3771 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 3772 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 3773 | |
a69b0ca4 | 3774 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 3775 | /* |
a69b0ca4 PZ |
3776 | * Mark this even as STATE_DEAD, there is no external reference to it |
3777 | * anymore. | |
683ede43 | 3778 | * |
a69b0ca4 PZ |
3779 | * Anybody acquiring event->child_mutex after the below loop _must_ |
3780 | * also see this, most importantly inherit_event() which will avoid | |
3781 | * placing more children on the list. | |
683ede43 | 3782 | * |
c6e5b732 PZ |
3783 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3784 | * child events. | |
683ede43 | 3785 | */ |
a69b0ca4 PZ |
3786 | event->state = PERF_EVENT_STATE_DEAD; |
3787 | raw_spin_unlock_irq(&ctx->lock); | |
3788 | ||
3789 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 3790 | |
c6e5b732 PZ |
3791 | again: |
3792 | mutex_lock(&event->child_mutex); | |
3793 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3794 | |
c6e5b732 PZ |
3795 | /* |
3796 | * Cannot change, child events are not migrated, see the | |
3797 | * comment with perf_event_ctx_lock_nested(). | |
3798 | */ | |
3799 | ctx = lockless_dereference(child->ctx); | |
3800 | /* | |
3801 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3802 | * through hoops. We start by grabbing a reference on the ctx. | |
3803 | * | |
3804 | * Since the event cannot get freed while we hold the | |
3805 | * child_mutex, the context must also exist and have a !0 | |
3806 | * reference count. | |
3807 | */ | |
3808 | get_ctx(ctx); | |
3809 | ||
3810 | /* | |
3811 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3812 | * acquire ctx::mutex without fear of it going away. Then we | |
3813 | * can re-acquire child_mutex. | |
3814 | */ | |
3815 | mutex_unlock(&event->child_mutex); | |
3816 | mutex_lock(&ctx->mutex); | |
3817 | mutex_lock(&event->child_mutex); | |
3818 | ||
3819 | /* | |
3820 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3821 | * state, if child is still the first entry, it didn't get freed | |
3822 | * and we can continue doing so. | |
3823 | */ | |
3824 | tmp = list_first_entry_or_null(&event->child_list, | |
3825 | struct perf_event, child_list); | |
3826 | if (tmp == child) { | |
3827 | perf_remove_from_context(child, DETACH_GROUP); | |
3828 | list_del(&child->child_list); | |
3829 | free_event(child); | |
3830 | /* | |
3831 | * This matches the refcount bump in inherit_event(); | |
3832 | * this can't be the last reference. | |
3833 | */ | |
3834 | put_event(event); | |
3835 | } | |
3836 | ||
3837 | mutex_unlock(&event->child_mutex); | |
3838 | mutex_unlock(&ctx->mutex); | |
3839 | put_ctx(ctx); | |
3840 | goto again; | |
3841 | } | |
3842 | mutex_unlock(&event->child_mutex); | |
3843 | ||
a4f4bb6d PZ |
3844 | no_ctx: |
3845 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
3846 | return 0; |
3847 | } | |
3848 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3849 | ||
8b10c5e2 PZ |
3850 | /* |
3851 | * Called when the last reference to the file is gone. | |
3852 | */ | |
a6fa941d AV |
3853 | static int perf_release(struct inode *inode, struct file *file) |
3854 | { | |
c6e5b732 | 3855 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3856 | return 0; |
fb0459d7 | 3857 | } |
fb0459d7 | 3858 | |
59ed446f | 3859 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3860 | { |
cdd6c482 | 3861 | struct perf_event *child; |
e53c0994 PZ |
3862 | u64 total = 0; |
3863 | ||
59ed446f PZ |
3864 | *enabled = 0; |
3865 | *running = 0; | |
3866 | ||
6f10581a | 3867 | mutex_lock(&event->child_mutex); |
01add3ea | 3868 | |
7d88962e | 3869 | (void)perf_event_read(event, false); |
01add3ea SB |
3870 | total += perf_event_count(event); |
3871 | ||
59ed446f PZ |
3872 | *enabled += event->total_time_enabled + |
3873 | atomic64_read(&event->child_total_time_enabled); | |
3874 | *running += event->total_time_running + | |
3875 | atomic64_read(&event->child_total_time_running); | |
3876 | ||
3877 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3878 | (void)perf_event_read(child, false); |
01add3ea | 3879 | total += perf_event_count(child); |
59ed446f PZ |
3880 | *enabled += child->total_time_enabled; |
3881 | *running += child->total_time_running; | |
3882 | } | |
6f10581a | 3883 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3884 | |
3885 | return total; | |
3886 | } | |
fb0459d7 | 3887 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3888 | |
7d88962e | 3889 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3890 | u64 read_format, u64 *values) |
3dab77fb | 3891 | { |
fa8c2693 PZ |
3892 | struct perf_event *sub; |
3893 | int n = 1; /* skip @nr */ | |
7d88962e | 3894 | int ret; |
f63a8daa | 3895 | |
7d88962e SB |
3896 | ret = perf_event_read(leader, true); |
3897 | if (ret) | |
3898 | return ret; | |
abf4868b | 3899 | |
fa8c2693 PZ |
3900 | /* |
3901 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3902 | * will be identical to those of the leader, so we only publish one | |
3903 | * set. | |
3904 | */ | |
3905 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3906 | values[n++] += leader->total_time_enabled + | |
3907 | atomic64_read(&leader->child_total_time_enabled); | |
3908 | } | |
3dab77fb | 3909 | |
fa8c2693 PZ |
3910 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3911 | values[n++] += leader->total_time_running + | |
3912 | atomic64_read(&leader->child_total_time_running); | |
3913 | } | |
3914 | ||
3915 | /* | |
3916 | * Write {count,id} tuples for every sibling. | |
3917 | */ | |
3918 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3919 | if (read_format & PERF_FORMAT_ID) |
3920 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3921 | |
fa8c2693 PZ |
3922 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3923 | values[n++] += perf_event_count(sub); | |
3924 | if (read_format & PERF_FORMAT_ID) | |
3925 | values[n++] = primary_event_id(sub); | |
3926 | } | |
7d88962e SB |
3927 | |
3928 | return 0; | |
fa8c2693 | 3929 | } |
3dab77fb | 3930 | |
fa8c2693 PZ |
3931 | static int perf_read_group(struct perf_event *event, |
3932 | u64 read_format, char __user *buf) | |
3933 | { | |
3934 | struct perf_event *leader = event->group_leader, *child; | |
3935 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3936 | int ret; |
fa8c2693 | 3937 | u64 *values; |
3dab77fb | 3938 | |
fa8c2693 | 3939 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3940 | |
fa8c2693 PZ |
3941 | values = kzalloc(event->read_size, GFP_KERNEL); |
3942 | if (!values) | |
3943 | return -ENOMEM; | |
3dab77fb | 3944 | |
fa8c2693 PZ |
3945 | values[0] = 1 + leader->nr_siblings; |
3946 | ||
3947 | /* | |
3948 | * By locking the child_mutex of the leader we effectively | |
3949 | * lock the child list of all siblings.. XXX explain how. | |
3950 | */ | |
3951 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3952 | |
7d88962e SB |
3953 | ret = __perf_read_group_add(leader, read_format, values); |
3954 | if (ret) | |
3955 | goto unlock; | |
3956 | ||
3957 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3958 | ret = __perf_read_group_add(child, read_format, values); | |
3959 | if (ret) | |
3960 | goto unlock; | |
3961 | } | |
abf4868b | 3962 | |
fa8c2693 | 3963 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3964 | |
7d88962e | 3965 | ret = event->read_size; |
fa8c2693 PZ |
3966 | if (copy_to_user(buf, values, event->read_size)) |
3967 | ret = -EFAULT; | |
7d88962e | 3968 | goto out; |
fa8c2693 | 3969 | |
7d88962e SB |
3970 | unlock: |
3971 | mutex_unlock(&leader->child_mutex); | |
3972 | out: | |
fa8c2693 | 3973 | kfree(values); |
abf4868b | 3974 | return ret; |
3dab77fb PZ |
3975 | } |
3976 | ||
b15f495b | 3977 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3978 | u64 read_format, char __user *buf) |
3979 | { | |
59ed446f | 3980 | u64 enabled, running; |
3dab77fb PZ |
3981 | u64 values[4]; |
3982 | int n = 0; | |
3983 | ||
59ed446f PZ |
3984 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3985 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3986 | values[n++] = enabled; | |
3987 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3988 | values[n++] = running; | |
3dab77fb | 3989 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3990 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3991 | |
3992 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3993 | return -EFAULT; | |
3994 | ||
3995 | return n * sizeof(u64); | |
3996 | } | |
3997 | ||
dc633982 JO |
3998 | static bool is_event_hup(struct perf_event *event) |
3999 | { | |
4000 | bool no_children; | |
4001 | ||
a69b0ca4 | 4002 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4003 | return false; |
4004 | ||
4005 | mutex_lock(&event->child_mutex); | |
4006 | no_children = list_empty(&event->child_list); | |
4007 | mutex_unlock(&event->child_mutex); | |
4008 | return no_children; | |
4009 | } | |
4010 | ||
0793a61d | 4011 | /* |
cdd6c482 | 4012 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4013 | */ |
4014 | static ssize_t | |
b15f495b | 4015 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4016 | { |
cdd6c482 | 4017 | u64 read_format = event->attr.read_format; |
3dab77fb | 4018 | int ret; |
0793a61d | 4019 | |
3b6f9e5c | 4020 | /* |
cdd6c482 | 4021 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4022 | * error state (i.e. because it was pinned but it couldn't be |
4023 | * scheduled on to the CPU at some point). | |
4024 | */ | |
cdd6c482 | 4025 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4026 | return 0; |
4027 | ||
c320c7b7 | 4028 | if (count < event->read_size) |
3dab77fb PZ |
4029 | return -ENOSPC; |
4030 | ||
cdd6c482 | 4031 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4032 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4033 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4034 | else |
b15f495b | 4035 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4036 | |
3dab77fb | 4037 | return ret; |
0793a61d TG |
4038 | } |
4039 | ||
0793a61d TG |
4040 | static ssize_t |
4041 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4042 | { | |
cdd6c482 | 4043 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4044 | struct perf_event_context *ctx; |
4045 | int ret; | |
0793a61d | 4046 | |
f63a8daa | 4047 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4048 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4049 | perf_event_ctx_unlock(event, ctx); |
4050 | ||
4051 | return ret; | |
0793a61d TG |
4052 | } |
4053 | ||
4054 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4055 | { | |
cdd6c482 | 4056 | struct perf_event *event = file->private_data; |
76369139 | 4057 | struct ring_buffer *rb; |
61b67684 | 4058 | unsigned int events = POLLHUP; |
c7138f37 | 4059 | |
e708d7ad | 4060 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4061 | |
dc633982 | 4062 | if (is_event_hup(event)) |
179033b3 | 4063 | return events; |
c7138f37 | 4064 | |
10c6db11 | 4065 | /* |
9bb5d40c PZ |
4066 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4067 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4068 | */ |
4069 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4070 | rb = event->rb; |
4071 | if (rb) | |
76369139 | 4072 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4073 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4074 | return events; |
4075 | } | |
4076 | ||
f63a8daa | 4077 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4078 | { |
7d88962e | 4079 | (void)perf_event_read(event, false); |
e7850595 | 4080 | local64_set(&event->count, 0); |
cdd6c482 | 4081 | perf_event_update_userpage(event); |
3df5edad PZ |
4082 | } |
4083 | ||
c93f7669 | 4084 | /* |
cdd6c482 IM |
4085 | * Holding the top-level event's child_mutex means that any |
4086 | * descendant process that has inherited this event will block | |
8ba289b8 | 4087 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4088 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4089 | */ |
cdd6c482 IM |
4090 | static void perf_event_for_each_child(struct perf_event *event, |
4091 | void (*func)(struct perf_event *)) | |
3df5edad | 4092 | { |
cdd6c482 | 4093 | struct perf_event *child; |
3df5edad | 4094 | |
cdd6c482 | 4095 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4096 | |
cdd6c482 IM |
4097 | mutex_lock(&event->child_mutex); |
4098 | func(event); | |
4099 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4100 | func(child); |
cdd6c482 | 4101 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4102 | } |
4103 | ||
cdd6c482 IM |
4104 | static void perf_event_for_each(struct perf_event *event, |
4105 | void (*func)(struct perf_event *)) | |
3df5edad | 4106 | { |
cdd6c482 IM |
4107 | struct perf_event_context *ctx = event->ctx; |
4108 | struct perf_event *sibling; | |
3df5edad | 4109 | |
f63a8daa PZ |
4110 | lockdep_assert_held(&ctx->mutex); |
4111 | ||
cdd6c482 | 4112 | event = event->group_leader; |
75f937f2 | 4113 | |
cdd6c482 | 4114 | perf_event_for_each_child(event, func); |
cdd6c482 | 4115 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4116 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4117 | } |
4118 | ||
fae3fde6 PZ |
4119 | static void __perf_event_period(struct perf_event *event, |
4120 | struct perf_cpu_context *cpuctx, | |
4121 | struct perf_event_context *ctx, | |
4122 | void *info) | |
c7999c6f | 4123 | { |
fae3fde6 | 4124 | u64 value = *((u64 *)info); |
c7999c6f | 4125 | bool active; |
08247e31 | 4126 | |
cdd6c482 | 4127 | if (event->attr.freq) { |
cdd6c482 | 4128 | event->attr.sample_freq = value; |
08247e31 | 4129 | } else { |
cdd6c482 IM |
4130 | event->attr.sample_period = value; |
4131 | event->hw.sample_period = value; | |
08247e31 | 4132 | } |
bad7192b PZ |
4133 | |
4134 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4135 | if (active) { | |
4136 | perf_pmu_disable(ctx->pmu); | |
4137 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4138 | } | |
4139 | ||
4140 | local64_set(&event->hw.period_left, 0); | |
4141 | ||
4142 | if (active) { | |
4143 | event->pmu->start(event, PERF_EF_RELOAD); | |
4144 | perf_pmu_enable(ctx->pmu); | |
4145 | } | |
c7999c6f PZ |
4146 | } |
4147 | ||
4148 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4149 | { | |
c7999c6f PZ |
4150 | u64 value; |
4151 | ||
4152 | if (!is_sampling_event(event)) | |
4153 | return -EINVAL; | |
4154 | ||
4155 | if (copy_from_user(&value, arg, sizeof(value))) | |
4156 | return -EFAULT; | |
4157 | ||
4158 | if (!value) | |
4159 | return -EINVAL; | |
4160 | ||
4161 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4162 | return -EINVAL; | |
4163 | ||
fae3fde6 | 4164 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4165 | |
c7999c6f | 4166 | return 0; |
08247e31 PZ |
4167 | } |
4168 | ||
ac9721f3 PZ |
4169 | static const struct file_operations perf_fops; |
4170 | ||
2903ff01 | 4171 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4172 | { |
2903ff01 AV |
4173 | struct fd f = fdget(fd); |
4174 | if (!f.file) | |
4175 | return -EBADF; | |
ac9721f3 | 4176 | |
2903ff01 AV |
4177 | if (f.file->f_op != &perf_fops) { |
4178 | fdput(f); | |
4179 | return -EBADF; | |
ac9721f3 | 4180 | } |
2903ff01 AV |
4181 | *p = f; |
4182 | return 0; | |
ac9721f3 PZ |
4183 | } |
4184 | ||
4185 | static int perf_event_set_output(struct perf_event *event, | |
4186 | struct perf_event *output_event); | |
6fb2915d | 4187 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4188 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4189 | |
f63a8daa | 4190 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4191 | { |
cdd6c482 | 4192 | void (*func)(struct perf_event *); |
3df5edad | 4193 | u32 flags = arg; |
d859e29f PM |
4194 | |
4195 | switch (cmd) { | |
cdd6c482 | 4196 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4197 | func = _perf_event_enable; |
d859e29f | 4198 | break; |
cdd6c482 | 4199 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4200 | func = _perf_event_disable; |
79f14641 | 4201 | break; |
cdd6c482 | 4202 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4203 | func = _perf_event_reset; |
6de6a7b9 | 4204 | break; |
3df5edad | 4205 | |
cdd6c482 | 4206 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4207 | return _perf_event_refresh(event, arg); |
08247e31 | 4208 | |
cdd6c482 IM |
4209 | case PERF_EVENT_IOC_PERIOD: |
4210 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4211 | |
cf4957f1 JO |
4212 | case PERF_EVENT_IOC_ID: |
4213 | { | |
4214 | u64 id = primary_event_id(event); | |
4215 | ||
4216 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4217 | return -EFAULT; | |
4218 | return 0; | |
4219 | } | |
4220 | ||
cdd6c482 | 4221 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4222 | { |
ac9721f3 | 4223 | int ret; |
ac9721f3 | 4224 | if (arg != -1) { |
2903ff01 AV |
4225 | struct perf_event *output_event; |
4226 | struct fd output; | |
4227 | ret = perf_fget_light(arg, &output); | |
4228 | if (ret) | |
4229 | return ret; | |
4230 | output_event = output.file->private_data; | |
4231 | ret = perf_event_set_output(event, output_event); | |
4232 | fdput(output); | |
4233 | } else { | |
4234 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4235 | } |
ac9721f3 PZ |
4236 | return ret; |
4237 | } | |
a4be7c27 | 4238 | |
6fb2915d LZ |
4239 | case PERF_EVENT_IOC_SET_FILTER: |
4240 | return perf_event_set_filter(event, (void __user *)arg); | |
4241 | ||
2541517c AS |
4242 | case PERF_EVENT_IOC_SET_BPF: |
4243 | return perf_event_set_bpf_prog(event, arg); | |
4244 | ||
d859e29f | 4245 | default: |
3df5edad | 4246 | return -ENOTTY; |
d859e29f | 4247 | } |
3df5edad PZ |
4248 | |
4249 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4250 | perf_event_for_each(event, func); |
3df5edad | 4251 | else |
cdd6c482 | 4252 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4253 | |
4254 | return 0; | |
d859e29f PM |
4255 | } |
4256 | ||
f63a8daa PZ |
4257 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4258 | { | |
4259 | struct perf_event *event = file->private_data; | |
4260 | struct perf_event_context *ctx; | |
4261 | long ret; | |
4262 | ||
4263 | ctx = perf_event_ctx_lock(event); | |
4264 | ret = _perf_ioctl(event, cmd, arg); | |
4265 | perf_event_ctx_unlock(event, ctx); | |
4266 | ||
4267 | return ret; | |
4268 | } | |
4269 | ||
b3f20785 PM |
4270 | #ifdef CONFIG_COMPAT |
4271 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4272 | unsigned long arg) | |
4273 | { | |
4274 | switch (_IOC_NR(cmd)) { | |
4275 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4276 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4277 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4278 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4279 | cmd &= ~IOCSIZE_MASK; | |
4280 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4281 | } | |
4282 | break; | |
4283 | } | |
4284 | return perf_ioctl(file, cmd, arg); | |
4285 | } | |
4286 | #else | |
4287 | # define perf_compat_ioctl NULL | |
4288 | #endif | |
4289 | ||
cdd6c482 | 4290 | int perf_event_task_enable(void) |
771d7cde | 4291 | { |
f63a8daa | 4292 | struct perf_event_context *ctx; |
cdd6c482 | 4293 | struct perf_event *event; |
771d7cde | 4294 | |
cdd6c482 | 4295 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4296 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4297 | ctx = perf_event_ctx_lock(event); | |
4298 | perf_event_for_each_child(event, _perf_event_enable); | |
4299 | perf_event_ctx_unlock(event, ctx); | |
4300 | } | |
cdd6c482 | 4301 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4302 | |
4303 | return 0; | |
4304 | } | |
4305 | ||
cdd6c482 | 4306 | int perf_event_task_disable(void) |
771d7cde | 4307 | { |
f63a8daa | 4308 | struct perf_event_context *ctx; |
cdd6c482 | 4309 | struct perf_event *event; |
771d7cde | 4310 | |
cdd6c482 | 4311 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4312 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4313 | ctx = perf_event_ctx_lock(event); | |
4314 | perf_event_for_each_child(event, _perf_event_disable); | |
4315 | perf_event_ctx_unlock(event, ctx); | |
4316 | } | |
cdd6c482 | 4317 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4318 | |
4319 | return 0; | |
4320 | } | |
4321 | ||
cdd6c482 | 4322 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4323 | { |
a4eaf7f1 PZ |
4324 | if (event->hw.state & PERF_HES_STOPPED) |
4325 | return 0; | |
4326 | ||
cdd6c482 | 4327 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4328 | return 0; |
4329 | ||
35edc2a5 | 4330 | return event->pmu->event_idx(event); |
194002b2 PZ |
4331 | } |
4332 | ||
c4794295 | 4333 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4334 | u64 *now, |
7f310a5d EM |
4335 | u64 *enabled, |
4336 | u64 *running) | |
c4794295 | 4337 | { |
e3f3541c | 4338 | u64 ctx_time; |
c4794295 | 4339 | |
e3f3541c PZ |
4340 | *now = perf_clock(); |
4341 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4342 | *enabled = ctx_time - event->tstamp_enabled; |
4343 | *running = ctx_time - event->tstamp_running; | |
4344 | } | |
4345 | ||
fa731587 PZ |
4346 | static void perf_event_init_userpage(struct perf_event *event) |
4347 | { | |
4348 | struct perf_event_mmap_page *userpg; | |
4349 | struct ring_buffer *rb; | |
4350 | ||
4351 | rcu_read_lock(); | |
4352 | rb = rcu_dereference(event->rb); | |
4353 | if (!rb) | |
4354 | goto unlock; | |
4355 | ||
4356 | userpg = rb->user_page; | |
4357 | ||
4358 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4359 | userpg->cap_bit0_is_deprecated = 1; | |
4360 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4361 | userpg->data_offset = PAGE_SIZE; |
4362 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4363 | |
4364 | unlock: | |
4365 | rcu_read_unlock(); | |
4366 | } | |
4367 | ||
c1317ec2 AL |
4368 | void __weak arch_perf_update_userpage( |
4369 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4370 | { |
4371 | } | |
4372 | ||
38ff667b PZ |
4373 | /* |
4374 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4375 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4376 | * code calls this from NMI context. | |
4377 | */ | |
cdd6c482 | 4378 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4379 | { |
cdd6c482 | 4380 | struct perf_event_mmap_page *userpg; |
76369139 | 4381 | struct ring_buffer *rb; |
e3f3541c | 4382 | u64 enabled, running, now; |
38ff667b PZ |
4383 | |
4384 | rcu_read_lock(); | |
5ec4c599 PZ |
4385 | rb = rcu_dereference(event->rb); |
4386 | if (!rb) | |
4387 | goto unlock; | |
4388 | ||
0d641208 EM |
4389 | /* |
4390 | * compute total_time_enabled, total_time_running | |
4391 | * based on snapshot values taken when the event | |
4392 | * was last scheduled in. | |
4393 | * | |
4394 | * we cannot simply called update_context_time() | |
4395 | * because of locking issue as we can be called in | |
4396 | * NMI context | |
4397 | */ | |
e3f3541c | 4398 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4399 | |
76369139 | 4400 | userpg = rb->user_page; |
7b732a75 PZ |
4401 | /* |
4402 | * Disable preemption so as to not let the corresponding user-space | |
4403 | * spin too long if we get preempted. | |
4404 | */ | |
4405 | preempt_disable(); | |
37d81828 | 4406 | ++userpg->lock; |
92f22a38 | 4407 | barrier(); |
cdd6c482 | 4408 | userpg->index = perf_event_index(event); |
b5e58793 | 4409 | userpg->offset = perf_event_count(event); |
365a4038 | 4410 | if (userpg->index) |
e7850595 | 4411 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4412 | |
0d641208 | 4413 | userpg->time_enabled = enabled + |
cdd6c482 | 4414 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4415 | |
0d641208 | 4416 | userpg->time_running = running + |
cdd6c482 | 4417 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4418 | |
c1317ec2 | 4419 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4420 | |
92f22a38 | 4421 | barrier(); |
37d81828 | 4422 | ++userpg->lock; |
7b732a75 | 4423 | preempt_enable(); |
38ff667b | 4424 | unlock: |
7b732a75 | 4425 | rcu_read_unlock(); |
37d81828 PM |
4426 | } |
4427 | ||
906010b2 PZ |
4428 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4429 | { | |
4430 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4431 | struct ring_buffer *rb; |
906010b2 PZ |
4432 | int ret = VM_FAULT_SIGBUS; |
4433 | ||
4434 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4435 | if (vmf->pgoff == 0) | |
4436 | ret = 0; | |
4437 | return ret; | |
4438 | } | |
4439 | ||
4440 | rcu_read_lock(); | |
76369139 FW |
4441 | rb = rcu_dereference(event->rb); |
4442 | if (!rb) | |
906010b2 PZ |
4443 | goto unlock; |
4444 | ||
4445 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4446 | goto unlock; | |
4447 | ||
76369139 | 4448 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4449 | if (!vmf->page) |
4450 | goto unlock; | |
4451 | ||
4452 | get_page(vmf->page); | |
4453 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4454 | vmf->page->index = vmf->pgoff; | |
4455 | ||
4456 | ret = 0; | |
4457 | unlock: | |
4458 | rcu_read_unlock(); | |
4459 | ||
4460 | return ret; | |
4461 | } | |
4462 | ||
10c6db11 PZ |
4463 | static void ring_buffer_attach(struct perf_event *event, |
4464 | struct ring_buffer *rb) | |
4465 | { | |
b69cf536 | 4466 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4467 | unsigned long flags; |
4468 | ||
b69cf536 PZ |
4469 | if (event->rb) { |
4470 | /* | |
4471 | * Should be impossible, we set this when removing | |
4472 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4473 | */ | |
4474 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4475 | |
b69cf536 | 4476 | old_rb = event->rb; |
b69cf536 PZ |
4477 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4478 | list_del_rcu(&event->rb_entry); | |
4479 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4480 | |
2f993cf0 ON |
4481 | event->rcu_batches = get_state_synchronize_rcu(); |
4482 | event->rcu_pending = 1; | |
b69cf536 | 4483 | } |
10c6db11 | 4484 | |
b69cf536 | 4485 | if (rb) { |
2f993cf0 ON |
4486 | if (event->rcu_pending) { |
4487 | cond_synchronize_rcu(event->rcu_batches); | |
4488 | event->rcu_pending = 0; | |
4489 | } | |
4490 | ||
b69cf536 PZ |
4491 | spin_lock_irqsave(&rb->event_lock, flags); |
4492 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4493 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4494 | } | |
4495 | ||
4496 | rcu_assign_pointer(event->rb, rb); | |
4497 | ||
4498 | if (old_rb) { | |
4499 | ring_buffer_put(old_rb); | |
4500 | /* | |
4501 | * Since we detached before setting the new rb, so that we | |
4502 | * could attach the new rb, we could have missed a wakeup. | |
4503 | * Provide it now. | |
4504 | */ | |
4505 | wake_up_all(&event->waitq); | |
4506 | } | |
10c6db11 PZ |
4507 | } |
4508 | ||
4509 | static void ring_buffer_wakeup(struct perf_event *event) | |
4510 | { | |
4511 | struct ring_buffer *rb; | |
4512 | ||
4513 | rcu_read_lock(); | |
4514 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4515 | if (rb) { |
4516 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4517 | wake_up_all(&event->waitq); | |
4518 | } | |
10c6db11 PZ |
4519 | rcu_read_unlock(); |
4520 | } | |
4521 | ||
fdc26706 | 4522 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4523 | { |
76369139 | 4524 | struct ring_buffer *rb; |
7b732a75 | 4525 | |
ac9721f3 | 4526 | rcu_read_lock(); |
76369139 FW |
4527 | rb = rcu_dereference(event->rb); |
4528 | if (rb) { | |
4529 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4530 | rb = NULL; | |
ac9721f3 PZ |
4531 | } |
4532 | rcu_read_unlock(); | |
4533 | ||
76369139 | 4534 | return rb; |
ac9721f3 PZ |
4535 | } |
4536 | ||
fdc26706 | 4537 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4538 | { |
76369139 | 4539 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4540 | return; |
7b732a75 | 4541 | |
9bb5d40c | 4542 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4543 | |
76369139 | 4544 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4545 | } |
4546 | ||
4547 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4548 | { | |
cdd6c482 | 4549 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4550 | |
cdd6c482 | 4551 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4552 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4553 | |
45bfb2e5 PZ |
4554 | if (vma->vm_pgoff) |
4555 | atomic_inc(&event->rb->aux_mmap_count); | |
4556 | ||
1e0fb9ec AL |
4557 | if (event->pmu->event_mapped) |
4558 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4559 | } |
4560 | ||
9bb5d40c PZ |
4561 | /* |
4562 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4563 | * event, or through other events by use of perf_event_set_output(). | |
4564 | * | |
4565 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4566 | * the buffer here, where we still have a VM context. This means we need | |
4567 | * to detach all events redirecting to us. | |
4568 | */ | |
7b732a75 PZ |
4569 | static void perf_mmap_close(struct vm_area_struct *vma) |
4570 | { | |
cdd6c482 | 4571 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4572 | |
b69cf536 | 4573 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4574 | struct user_struct *mmap_user = rb->mmap_user; |
4575 | int mmap_locked = rb->mmap_locked; | |
4576 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4577 | |
1e0fb9ec AL |
4578 | if (event->pmu->event_unmapped) |
4579 | event->pmu->event_unmapped(event); | |
4580 | ||
45bfb2e5 PZ |
4581 | /* |
4582 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4583 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4584 | * serialize with perf_mmap here. | |
4585 | */ | |
4586 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4587 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4588 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4589 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4590 | ||
4591 | rb_free_aux(rb); | |
4592 | mutex_unlock(&event->mmap_mutex); | |
4593 | } | |
4594 | ||
9bb5d40c PZ |
4595 | atomic_dec(&rb->mmap_count); |
4596 | ||
4597 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4598 | goto out_put; |
9bb5d40c | 4599 | |
b69cf536 | 4600 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4601 | mutex_unlock(&event->mmap_mutex); |
4602 | ||
4603 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4604 | if (atomic_read(&rb->mmap_count)) |
4605 | goto out_put; | |
ac9721f3 | 4606 | |
9bb5d40c PZ |
4607 | /* |
4608 | * No other mmap()s, detach from all other events that might redirect | |
4609 | * into the now unreachable buffer. Somewhat complicated by the | |
4610 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4611 | */ | |
4612 | again: | |
4613 | rcu_read_lock(); | |
4614 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4615 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4616 | /* | |
4617 | * This event is en-route to free_event() which will | |
4618 | * detach it and remove it from the list. | |
4619 | */ | |
4620 | continue; | |
4621 | } | |
4622 | rcu_read_unlock(); | |
789f90fc | 4623 | |
9bb5d40c PZ |
4624 | mutex_lock(&event->mmap_mutex); |
4625 | /* | |
4626 | * Check we didn't race with perf_event_set_output() which can | |
4627 | * swizzle the rb from under us while we were waiting to | |
4628 | * acquire mmap_mutex. | |
4629 | * | |
4630 | * If we find a different rb; ignore this event, a next | |
4631 | * iteration will no longer find it on the list. We have to | |
4632 | * still restart the iteration to make sure we're not now | |
4633 | * iterating the wrong list. | |
4634 | */ | |
b69cf536 PZ |
4635 | if (event->rb == rb) |
4636 | ring_buffer_attach(event, NULL); | |
4637 | ||
cdd6c482 | 4638 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4639 | put_event(event); |
ac9721f3 | 4640 | |
9bb5d40c PZ |
4641 | /* |
4642 | * Restart the iteration; either we're on the wrong list or | |
4643 | * destroyed its integrity by doing a deletion. | |
4644 | */ | |
4645 | goto again; | |
7b732a75 | 4646 | } |
9bb5d40c PZ |
4647 | rcu_read_unlock(); |
4648 | ||
4649 | /* | |
4650 | * It could be there's still a few 0-ref events on the list; they'll | |
4651 | * get cleaned up by free_event() -- they'll also still have their | |
4652 | * ref on the rb and will free it whenever they are done with it. | |
4653 | * | |
4654 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4655 | * undo the VM accounting. | |
4656 | */ | |
4657 | ||
4658 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4659 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4660 | free_uid(mmap_user); | |
4661 | ||
b69cf536 | 4662 | out_put: |
9bb5d40c | 4663 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4664 | } |
4665 | ||
f0f37e2f | 4666 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4667 | .open = perf_mmap_open, |
45bfb2e5 | 4668 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4669 | .fault = perf_mmap_fault, |
4670 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4671 | }; |
4672 | ||
4673 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4674 | { | |
cdd6c482 | 4675 | struct perf_event *event = file->private_data; |
22a4f650 | 4676 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4677 | struct user_struct *user = current_user(); |
22a4f650 | 4678 | unsigned long locked, lock_limit; |
45bfb2e5 | 4679 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4680 | unsigned long vma_size; |
4681 | unsigned long nr_pages; | |
45bfb2e5 | 4682 | long user_extra = 0, extra = 0; |
d57e34fd | 4683 | int ret = 0, flags = 0; |
37d81828 | 4684 | |
c7920614 PZ |
4685 | /* |
4686 | * Don't allow mmap() of inherited per-task counters. This would | |
4687 | * create a performance issue due to all children writing to the | |
76369139 | 4688 | * same rb. |
c7920614 PZ |
4689 | */ |
4690 | if (event->cpu == -1 && event->attr.inherit) | |
4691 | return -EINVAL; | |
4692 | ||
43a21ea8 | 4693 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4694 | return -EINVAL; |
7b732a75 PZ |
4695 | |
4696 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4697 | |
4698 | if (vma->vm_pgoff == 0) { | |
4699 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4700 | } else { | |
4701 | /* | |
4702 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4703 | * mapped, all subsequent mappings should have the same size | |
4704 | * and offset. Must be above the normal perf buffer. | |
4705 | */ | |
4706 | u64 aux_offset, aux_size; | |
4707 | ||
4708 | if (!event->rb) | |
4709 | return -EINVAL; | |
4710 | ||
4711 | nr_pages = vma_size / PAGE_SIZE; | |
4712 | ||
4713 | mutex_lock(&event->mmap_mutex); | |
4714 | ret = -EINVAL; | |
4715 | ||
4716 | rb = event->rb; | |
4717 | if (!rb) | |
4718 | goto aux_unlock; | |
4719 | ||
4720 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4721 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4722 | ||
4723 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4724 | goto aux_unlock; | |
4725 | ||
4726 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4727 | goto aux_unlock; | |
4728 | ||
4729 | /* already mapped with a different offset */ | |
4730 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4731 | goto aux_unlock; | |
4732 | ||
4733 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4734 | goto aux_unlock; | |
4735 | ||
4736 | /* already mapped with a different size */ | |
4737 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4738 | goto aux_unlock; | |
4739 | ||
4740 | if (!is_power_of_2(nr_pages)) | |
4741 | goto aux_unlock; | |
4742 | ||
4743 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4744 | goto aux_unlock; | |
4745 | ||
4746 | if (rb_has_aux(rb)) { | |
4747 | atomic_inc(&rb->aux_mmap_count); | |
4748 | ret = 0; | |
4749 | goto unlock; | |
4750 | } | |
4751 | ||
4752 | atomic_set(&rb->aux_mmap_count, 1); | |
4753 | user_extra = nr_pages; | |
4754 | ||
4755 | goto accounting; | |
4756 | } | |
7b732a75 | 4757 | |
7730d865 | 4758 | /* |
76369139 | 4759 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4760 | * can do bitmasks instead of modulo. |
4761 | */ | |
2ed11312 | 4762 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4763 | return -EINVAL; |
4764 | ||
7b732a75 | 4765 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4766 | return -EINVAL; |
4767 | ||
cdd6c482 | 4768 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4769 | again: |
cdd6c482 | 4770 | mutex_lock(&event->mmap_mutex); |
76369139 | 4771 | if (event->rb) { |
9bb5d40c | 4772 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4773 | ret = -EINVAL; |
9bb5d40c PZ |
4774 | goto unlock; |
4775 | } | |
4776 | ||
4777 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4778 | /* | |
4779 | * Raced against perf_mmap_close() through | |
4780 | * perf_event_set_output(). Try again, hope for better | |
4781 | * luck. | |
4782 | */ | |
4783 | mutex_unlock(&event->mmap_mutex); | |
4784 | goto again; | |
4785 | } | |
4786 | ||
ebb3c4c4 PZ |
4787 | goto unlock; |
4788 | } | |
4789 | ||
789f90fc | 4790 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4791 | |
4792 | accounting: | |
cdd6c482 | 4793 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4794 | |
4795 | /* | |
4796 | * Increase the limit linearly with more CPUs: | |
4797 | */ | |
4798 | user_lock_limit *= num_online_cpus(); | |
4799 | ||
789f90fc | 4800 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4801 | |
789f90fc PZ |
4802 | if (user_locked > user_lock_limit) |
4803 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4804 | |
78d7d407 | 4805 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4806 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4807 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4808 | |
459ec28a IM |
4809 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4810 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4811 | ret = -EPERM; |
4812 | goto unlock; | |
4813 | } | |
7b732a75 | 4814 | |
45bfb2e5 | 4815 | WARN_ON(!rb && event->rb); |
906010b2 | 4816 | |
d57e34fd | 4817 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4818 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4819 | |
76369139 | 4820 | if (!rb) { |
45bfb2e5 PZ |
4821 | rb = rb_alloc(nr_pages, |
4822 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4823 | event->cpu, flags); | |
26cb63ad | 4824 | |
45bfb2e5 PZ |
4825 | if (!rb) { |
4826 | ret = -ENOMEM; | |
4827 | goto unlock; | |
4828 | } | |
43a21ea8 | 4829 | |
45bfb2e5 PZ |
4830 | atomic_set(&rb->mmap_count, 1); |
4831 | rb->mmap_user = get_current_user(); | |
4832 | rb->mmap_locked = extra; | |
26cb63ad | 4833 | |
45bfb2e5 | 4834 | ring_buffer_attach(event, rb); |
ac9721f3 | 4835 | |
45bfb2e5 PZ |
4836 | perf_event_init_userpage(event); |
4837 | perf_event_update_userpage(event); | |
4838 | } else { | |
1a594131 AS |
4839 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4840 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4841 | if (!ret) |
4842 | rb->aux_mmap_locked = extra; | |
4843 | } | |
9a0f05cb | 4844 | |
ebb3c4c4 | 4845 | unlock: |
45bfb2e5 PZ |
4846 | if (!ret) { |
4847 | atomic_long_add(user_extra, &user->locked_vm); | |
4848 | vma->vm_mm->pinned_vm += extra; | |
4849 | ||
ac9721f3 | 4850 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4851 | } else if (rb) { |
4852 | atomic_dec(&rb->mmap_count); | |
4853 | } | |
4854 | aux_unlock: | |
cdd6c482 | 4855 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4856 | |
9bb5d40c PZ |
4857 | /* |
4858 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4859 | * vma. | |
4860 | */ | |
26cb63ad | 4861 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4862 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4863 | |
1e0fb9ec AL |
4864 | if (event->pmu->event_mapped) |
4865 | event->pmu->event_mapped(event); | |
4866 | ||
7b732a75 | 4867 | return ret; |
37d81828 PM |
4868 | } |
4869 | ||
3c446b3d PZ |
4870 | static int perf_fasync(int fd, struct file *filp, int on) |
4871 | { | |
496ad9aa | 4872 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4873 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4874 | int retval; |
4875 | ||
5955102c | 4876 | inode_lock(inode); |
cdd6c482 | 4877 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 4878 | inode_unlock(inode); |
3c446b3d PZ |
4879 | |
4880 | if (retval < 0) | |
4881 | return retval; | |
4882 | ||
4883 | return 0; | |
4884 | } | |
4885 | ||
0793a61d | 4886 | static const struct file_operations perf_fops = { |
3326c1ce | 4887 | .llseek = no_llseek, |
0793a61d TG |
4888 | .release = perf_release, |
4889 | .read = perf_read, | |
4890 | .poll = perf_poll, | |
d859e29f | 4891 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4892 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4893 | .mmap = perf_mmap, |
3c446b3d | 4894 | .fasync = perf_fasync, |
0793a61d TG |
4895 | }; |
4896 | ||
925d519a | 4897 | /* |
cdd6c482 | 4898 | * Perf event wakeup |
925d519a PZ |
4899 | * |
4900 | * If there's data, ensure we set the poll() state and publish everything | |
4901 | * to user-space before waking everybody up. | |
4902 | */ | |
4903 | ||
fed66e2c PZ |
4904 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4905 | { | |
4906 | /* only the parent has fasync state */ | |
4907 | if (event->parent) | |
4908 | event = event->parent; | |
4909 | return &event->fasync; | |
4910 | } | |
4911 | ||
cdd6c482 | 4912 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4913 | { |
10c6db11 | 4914 | ring_buffer_wakeup(event); |
4c9e2542 | 4915 | |
cdd6c482 | 4916 | if (event->pending_kill) { |
fed66e2c | 4917 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4918 | event->pending_kill = 0; |
4c9e2542 | 4919 | } |
925d519a PZ |
4920 | } |
4921 | ||
e360adbe | 4922 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4923 | { |
cdd6c482 IM |
4924 | struct perf_event *event = container_of(entry, |
4925 | struct perf_event, pending); | |
d525211f PZ |
4926 | int rctx; |
4927 | ||
4928 | rctx = perf_swevent_get_recursion_context(); | |
4929 | /* | |
4930 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4931 | * and we won't recurse 'further'. | |
4932 | */ | |
79f14641 | 4933 | |
cdd6c482 IM |
4934 | if (event->pending_disable) { |
4935 | event->pending_disable = 0; | |
fae3fde6 | 4936 | perf_event_disable_local(event); |
79f14641 PZ |
4937 | } |
4938 | ||
cdd6c482 IM |
4939 | if (event->pending_wakeup) { |
4940 | event->pending_wakeup = 0; | |
4941 | perf_event_wakeup(event); | |
79f14641 | 4942 | } |
d525211f PZ |
4943 | |
4944 | if (rctx >= 0) | |
4945 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4946 | } |
4947 | ||
39447b38 ZY |
4948 | /* |
4949 | * We assume there is only KVM supporting the callbacks. | |
4950 | * Later on, we might change it to a list if there is | |
4951 | * another virtualization implementation supporting the callbacks. | |
4952 | */ | |
4953 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4954 | ||
4955 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4956 | { | |
4957 | perf_guest_cbs = cbs; | |
4958 | return 0; | |
4959 | } | |
4960 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4961 | ||
4962 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4963 | { | |
4964 | perf_guest_cbs = NULL; | |
4965 | return 0; | |
4966 | } | |
4967 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4968 | ||
4018994f JO |
4969 | static void |
4970 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4971 | struct pt_regs *regs, u64 mask) | |
4972 | { | |
4973 | int bit; | |
4974 | ||
4975 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4976 | sizeof(mask) * BITS_PER_BYTE) { | |
4977 | u64 val; | |
4978 | ||
4979 | val = perf_reg_value(regs, bit); | |
4980 | perf_output_put(handle, val); | |
4981 | } | |
4982 | } | |
4983 | ||
60e2364e | 4984 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4985 | struct pt_regs *regs, |
4986 | struct pt_regs *regs_user_copy) | |
4018994f | 4987 | { |
88a7c26a AL |
4988 | if (user_mode(regs)) { |
4989 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4990 | regs_user->regs = regs; |
88a7c26a AL |
4991 | } else if (current->mm) { |
4992 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4993 | } else { |
4994 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4995 | regs_user->regs = NULL; | |
4018994f JO |
4996 | } |
4997 | } | |
4998 | ||
60e2364e SE |
4999 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5000 | struct pt_regs *regs) | |
5001 | { | |
5002 | regs_intr->regs = regs; | |
5003 | regs_intr->abi = perf_reg_abi(current); | |
5004 | } | |
5005 | ||
5006 | ||
c5ebcedb JO |
5007 | /* |
5008 | * Get remaining task size from user stack pointer. | |
5009 | * | |
5010 | * It'd be better to take stack vma map and limit this more | |
5011 | * precisly, but there's no way to get it safely under interrupt, | |
5012 | * so using TASK_SIZE as limit. | |
5013 | */ | |
5014 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5015 | { | |
5016 | unsigned long addr = perf_user_stack_pointer(regs); | |
5017 | ||
5018 | if (!addr || addr >= TASK_SIZE) | |
5019 | return 0; | |
5020 | ||
5021 | return TASK_SIZE - addr; | |
5022 | } | |
5023 | ||
5024 | static u16 | |
5025 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5026 | struct pt_regs *regs) | |
5027 | { | |
5028 | u64 task_size; | |
5029 | ||
5030 | /* No regs, no stack pointer, no dump. */ | |
5031 | if (!regs) | |
5032 | return 0; | |
5033 | ||
5034 | /* | |
5035 | * Check if we fit in with the requested stack size into the: | |
5036 | * - TASK_SIZE | |
5037 | * If we don't, we limit the size to the TASK_SIZE. | |
5038 | * | |
5039 | * - remaining sample size | |
5040 | * If we don't, we customize the stack size to | |
5041 | * fit in to the remaining sample size. | |
5042 | */ | |
5043 | ||
5044 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5045 | stack_size = min(stack_size, (u16) task_size); | |
5046 | ||
5047 | /* Current header size plus static size and dynamic size. */ | |
5048 | header_size += 2 * sizeof(u64); | |
5049 | ||
5050 | /* Do we fit in with the current stack dump size? */ | |
5051 | if ((u16) (header_size + stack_size) < header_size) { | |
5052 | /* | |
5053 | * If we overflow the maximum size for the sample, | |
5054 | * we customize the stack dump size to fit in. | |
5055 | */ | |
5056 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5057 | stack_size = round_up(stack_size, sizeof(u64)); | |
5058 | } | |
5059 | ||
5060 | return stack_size; | |
5061 | } | |
5062 | ||
5063 | static void | |
5064 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5065 | struct pt_regs *regs) | |
5066 | { | |
5067 | /* Case of a kernel thread, nothing to dump */ | |
5068 | if (!regs) { | |
5069 | u64 size = 0; | |
5070 | perf_output_put(handle, size); | |
5071 | } else { | |
5072 | unsigned long sp; | |
5073 | unsigned int rem; | |
5074 | u64 dyn_size; | |
5075 | ||
5076 | /* | |
5077 | * We dump: | |
5078 | * static size | |
5079 | * - the size requested by user or the best one we can fit | |
5080 | * in to the sample max size | |
5081 | * data | |
5082 | * - user stack dump data | |
5083 | * dynamic size | |
5084 | * - the actual dumped size | |
5085 | */ | |
5086 | ||
5087 | /* Static size. */ | |
5088 | perf_output_put(handle, dump_size); | |
5089 | ||
5090 | /* Data. */ | |
5091 | sp = perf_user_stack_pointer(regs); | |
5092 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5093 | dyn_size = dump_size - rem; | |
5094 | ||
5095 | perf_output_skip(handle, rem); | |
5096 | ||
5097 | /* Dynamic size. */ | |
5098 | perf_output_put(handle, dyn_size); | |
5099 | } | |
5100 | } | |
5101 | ||
c980d109 ACM |
5102 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5103 | struct perf_sample_data *data, | |
5104 | struct perf_event *event) | |
6844c09d ACM |
5105 | { |
5106 | u64 sample_type = event->attr.sample_type; | |
5107 | ||
5108 | data->type = sample_type; | |
5109 | header->size += event->id_header_size; | |
5110 | ||
5111 | if (sample_type & PERF_SAMPLE_TID) { | |
5112 | /* namespace issues */ | |
5113 | data->tid_entry.pid = perf_event_pid(event, current); | |
5114 | data->tid_entry.tid = perf_event_tid(event, current); | |
5115 | } | |
5116 | ||
5117 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5118 | data->time = perf_event_clock(event); |
6844c09d | 5119 | |
ff3d527c | 5120 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5121 | data->id = primary_event_id(event); |
5122 | ||
5123 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5124 | data->stream_id = event->id; | |
5125 | ||
5126 | if (sample_type & PERF_SAMPLE_CPU) { | |
5127 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5128 | data->cpu_entry.reserved = 0; | |
5129 | } | |
5130 | } | |
5131 | ||
76369139 FW |
5132 | void perf_event_header__init_id(struct perf_event_header *header, |
5133 | struct perf_sample_data *data, | |
5134 | struct perf_event *event) | |
c980d109 ACM |
5135 | { |
5136 | if (event->attr.sample_id_all) | |
5137 | __perf_event_header__init_id(header, data, event); | |
5138 | } | |
5139 | ||
5140 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5141 | struct perf_sample_data *data) | |
5142 | { | |
5143 | u64 sample_type = data->type; | |
5144 | ||
5145 | if (sample_type & PERF_SAMPLE_TID) | |
5146 | perf_output_put(handle, data->tid_entry); | |
5147 | ||
5148 | if (sample_type & PERF_SAMPLE_TIME) | |
5149 | perf_output_put(handle, data->time); | |
5150 | ||
5151 | if (sample_type & PERF_SAMPLE_ID) | |
5152 | perf_output_put(handle, data->id); | |
5153 | ||
5154 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5155 | perf_output_put(handle, data->stream_id); | |
5156 | ||
5157 | if (sample_type & PERF_SAMPLE_CPU) | |
5158 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5159 | |
5160 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5161 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5162 | } |
5163 | ||
76369139 FW |
5164 | void perf_event__output_id_sample(struct perf_event *event, |
5165 | struct perf_output_handle *handle, | |
5166 | struct perf_sample_data *sample) | |
c980d109 ACM |
5167 | { |
5168 | if (event->attr.sample_id_all) | |
5169 | __perf_event__output_id_sample(handle, sample); | |
5170 | } | |
5171 | ||
3dab77fb | 5172 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5173 | struct perf_event *event, |
5174 | u64 enabled, u64 running) | |
3dab77fb | 5175 | { |
cdd6c482 | 5176 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5177 | u64 values[4]; |
5178 | int n = 0; | |
5179 | ||
b5e58793 | 5180 | values[n++] = perf_event_count(event); |
3dab77fb | 5181 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5182 | values[n++] = enabled + |
cdd6c482 | 5183 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5184 | } |
5185 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5186 | values[n++] = running + |
cdd6c482 | 5187 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5188 | } |
5189 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5190 | values[n++] = primary_event_id(event); |
3dab77fb | 5191 | |
76369139 | 5192 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5193 | } |
5194 | ||
5195 | /* | |
cdd6c482 | 5196 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5197 | */ |
5198 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5199 | struct perf_event *event, |
5200 | u64 enabled, u64 running) | |
3dab77fb | 5201 | { |
cdd6c482 IM |
5202 | struct perf_event *leader = event->group_leader, *sub; |
5203 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5204 | u64 values[5]; |
5205 | int n = 0; | |
5206 | ||
5207 | values[n++] = 1 + leader->nr_siblings; | |
5208 | ||
5209 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5210 | values[n++] = enabled; |
3dab77fb PZ |
5211 | |
5212 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5213 | values[n++] = running; |
3dab77fb | 5214 | |
cdd6c482 | 5215 | if (leader != event) |
3dab77fb PZ |
5216 | leader->pmu->read(leader); |
5217 | ||
b5e58793 | 5218 | values[n++] = perf_event_count(leader); |
3dab77fb | 5219 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5220 | values[n++] = primary_event_id(leader); |
3dab77fb | 5221 | |
76369139 | 5222 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5223 | |
65abc865 | 5224 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5225 | n = 0; |
5226 | ||
6f5ab001 JO |
5227 | if ((sub != event) && |
5228 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5229 | sub->pmu->read(sub); |
5230 | ||
b5e58793 | 5231 | values[n++] = perf_event_count(sub); |
3dab77fb | 5232 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5233 | values[n++] = primary_event_id(sub); |
3dab77fb | 5234 | |
76369139 | 5235 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5236 | } |
5237 | } | |
5238 | ||
eed01528 SE |
5239 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5240 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5241 | ||
3dab77fb | 5242 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5243 | struct perf_event *event) |
3dab77fb | 5244 | { |
e3f3541c | 5245 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5246 | u64 read_format = event->attr.read_format; |
5247 | ||
5248 | /* | |
5249 | * compute total_time_enabled, total_time_running | |
5250 | * based on snapshot values taken when the event | |
5251 | * was last scheduled in. | |
5252 | * | |
5253 | * we cannot simply called update_context_time() | |
5254 | * because of locking issue as we are called in | |
5255 | * NMI context | |
5256 | */ | |
c4794295 | 5257 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5258 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5259 | |
cdd6c482 | 5260 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5261 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5262 | else |
eed01528 | 5263 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5264 | } |
5265 | ||
5622f295 MM |
5266 | void perf_output_sample(struct perf_output_handle *handle, |
5267 | struct perf_event_header *header, | |
5268 | struct perf_sample_data *data, | |
cdd6c482 | 5269 | struct perf_event *event) |
5622f295 MM |
5270 | { |
5271 | u64 sample_type = data->type; | |
5272 | ||
5273 | perf_output_put(handle, *header); | |
5274 | ||
ff3d527c AH |
5275 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5276 | perf_output_put(handle, data->id); | |
5277 | ||
5622f295 MM |
5278 | if (sample_type & PERF_SAMPLE_IP) |
5279 | perf_output_put(handle, data->ip); | |
5280 | ||
5281 | if (sample_type & PERF_SAMPLE_TID) | |
5282 | perf_output_put(handle, data->tid_entry); | |
5283 | ||
5284 | if (sample_type & PERF_SAMPLE_TIME) | |
5285 | perf_output_put(handle, data->time); | |
5286 | ||
5287 | if (sample_type & PERF_SAMPLE_ADDR) | |
5288 | perf_output_put(handle, data->addr); | |
5289 | ||
5290 | if (sample_type & PERF_SAMPLE_ID) | |
5291 | perf_output_put(handle, data->id); | |
5292 | ||
5293 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5294 | perf_output_put(handle, data->stream_id); | |
5295 | ||
5296 | if (sample_type & PERF_SAMPLE_CPU) | |
5297 | perf_output_put(handle, data->cpu_entry); | |
5298 | ||
5299 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5300 | perf_output_put(handle, data->period); | |
5301 | ||
5302 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5303 | perf_output_read(handle, event); |
5622f295 MM |
5304 | |
5305 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5306 | if (data->callchain) { | |
5307 | int size = 1; | |
5308 | ||
5309 | if (data->callchain) | |
5310 | size += data->callchain->nr; | |
5311 | ||
5312 | size *= sizeof(u64); | |
5313 | ||
76369139 | 5314 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5315 | } else { |
5316 | u64 nr = 0; | |
5317 | perf_output_put(handle, nr); | |
5318 | } | |
5319 | } | |
5320 | ||
5321 | if (sample_type & PERF_SAMPLE_RAW) { | |
5322 | if (data->raw) { | |
fa128e6a AS |
5323 | u32 raw_size = data->raw->size; |
5324 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5325 | sizeof(u64)) - sizeof(u32); | |
5326 | u64 zero = 0; | |
5327 | ||
5328 | perf_output_put(handle, real_size); | |
5329 | __output_copy(handle, data->raw->data, raw_size); | |
5330 | if (real_size - raw_size) | |
5331 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5332 | } else { |
5333 | struct { | |
5334 | u32 size; | |
5335 | u32 data; | |
5336 | } raw = { | |
5337 | .size = sizeof(u32), | |
5338 | .data = 0, | |
5339 | }; | |
5340 | perf_output_put(handle, raw); | |
5341 | } | |
5342 | } | |
a7ac67ea | 5343 | |
bce38cd5 SE |
5344 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5345 | if (data->br_stack) { | |
5346 | size_t size; | |
5347 | ||
5348 | size = data->br_stack->nr | |
5349 | * sizeof(struct perf_branch_entry); | |
5350 | ||
5351 | perf_output_put(handle, data->br_stack->nr); | |
5352 | perf_output_copy(handle, data->br_stack->entries, size); | |
5353 | } else { | |
5354 | /* | |
5355 | * we always store at least the value of nr | |
5356 | */ | |
5357 | u64 nr = 0; | |
5358 | perf_output_put(handle, nr); | |
5359 | } | |
5360 | } | |
4018994f JO |
5361 | |
5362 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5363 | u64 abi = data->regs_user.abi; | |
5364 | ||
5365 | /* | |
5366 | * If there are no regs to dump, notice it through | |
5367 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5368 | */ | |
5369 | perf_output_put(handle, abi); | |
5370 | ||
5371 | if (abi) { | |
5372 | u64 mask = event->attr.sample_regs_user; | |
5373 | perf_output_sample_regs(handle, | |
5374 | data->regs_user.regs, | |
5375 | mask); | |
5376 | } | |
5377 | } | |
c5ebcedb | 5378 | |
a5cdd40c | 5379 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5380 | perf_output_sample_ustack(handle, |
5381 | data->stack_user_size, | |
5382 | data->regs_user.regs); | |
a5cdd40c | 5383 | } |
c3feedf2 AK |
5384 | |
5385 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5386 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5387 | |
5388 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5389 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5390 | |
fdfbbd07 AK |
5391 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5392 | perf_output_put(handle, data->txn); | |
5393 | ||
60e2364e SE |
5394 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5395 | u64 abi = data->regs_intr.abi; | |
5396 | /* | |
5397 | * If there are no regs to dump, notice it through | |
5398 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5399 | */ | |
5400 | perf_output_put(handle, abi); | |
5401 | ||
5402 | if (abi) { | |
5403 | u64 mask = event->attr.sample_regs_intr; | |
5404 | ||
5405 | perf_output_sample_regs(handle, | |
5406 | data->regs_intr.regs, | |
5407 | mask); | |
5408 | } | |
5409 | } | |
5410 | ||
a5cdd40c PZ |
5411 | if (!event->attr.watermark) { |
5412 | int wakeup_events = event->attr.wakeup_events; | |
5413 | ||
5414 | if (wakeup_events) { | |
5415 | struct ring_buffer *rb = handle->rb; | |
5416 | int events = local_inc_return(&rb->events); | |
5417 | ||
5418 | if (events >= wakeup_events) { | |
5419 | local_sub(wakeup_events, &rb->events); | |
5420 | local_inc(&rb->wakeup); | |
5421 | } | |
5422 | } | |
5423 | } | |
5622f295 MM |
5424 | } |
5425 | ||
5426 | void perf_prepare_sample(struct perf_event_header *header, | |
5427 | struct perf_sample_data *data, | |
cdd6c482 | 5428 | struct perf_event *event, |
5622f295 | 5429 | struct pt_regs *regs) |
7b732a75 | 5430 | { |
cdd6c482 | 5431 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5432 | |
cdd6c482 | 5433 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5434 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5435 | |
5436 | header->misc = 0; | |
5437 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5438 | |
c980d109 | 5439 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5440 | |
c320c7b7 | 5441 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5442 | data->ip = perf_instruction_pointer(regs); |
5443 | ||
b23f3325 | 5444 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5445 | int size = 1; |
394ee076 | 5446 | |
e6dab5ff | 5447 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5448 | |
5449 | if (data->callchain) | |
5450 | size += data->callchain->nr; | |
5451 | ||
5452 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5453 | } |
5454 | ||
3a43ce68 | 5455 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5456 | int size = sizeof(u32); |
5457 | ||
5458 | if (data->raw) | |
5459 | size += data->raw->size; | |
5460 | else | |
5461 | size += sizeof(u32); | |
5462 | ||
fa128e6a | 5463 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5464 | } |
bce38cd5 SE |
5465 | |
5466 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5467 | int size = sizeof(u64); /* nr */ | |
5468 | if (data->br_stack) { | |
5469 | size += data->br_stack->nr | |
5470 | * sizeof(struct perf_branch_entry); | |
5471 | } | |
5472 | header->size += size; | |
5473 | } | |
4018994f | 5474 | |
2565711f | 5475 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5476 | perf_sample_regs_user(&data->regs_user, regs, |
5477 | &data->regs_user_copy); | |
2565711f | 5478 | |
4018994f JO |
5479 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5480 | /* regs dump ABI info */ | |
5481 | int size = sizeof(u64); | |
5482 | ||
4018994f JO |
5483 | if (data->regs_user.regs) { |
5484 | u64 mask = event->attr.sample_regs_user; | |
5485 | size += hweight64(mask) * sizeof(u64); | |
5486 | } | |
5487 | ||
5488 | header->size += size; | |
5489 | } | |
c5ebcedb JO |
5490 | |
5491 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5492 | /* | |
5493 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5494 | * processed as the last one or have additional check added | |
5495 | * in case new sample type is added, because we could eat | |
5496 | * up the rest of the sample size. | |
5497 | */ | |
c5ebcedb JO |
5498 | u16 stack_size = event->attr.sample_stack_user; |
5499 | u16 size = sizeof(u64); | |
5500 | ||
c5ebcedb | 5501 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5502 | data->regs_user.regs); |
c5ebcedb JO |
5503 | |
5504 | /* | |
5505 | * If there is something to dump, add space for the dump | |
5506 | * itself and for the field that tells the dynamic size, | |
5507 | * which is how many have been actually dumped. | |
5508 | */ | |
5509 | if (stack_size) | |
5510 | size += sizeof(u64) + stack_size; | |
5511 | ||
5512 | data->stack_user_size = stack_size; | |
5513 | header->size += size; | |
5514 | } | |
60e2364e SE |
5515 | |
5516 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5517 | /* regs dump ABI info */ | |
5518 | int size = sizeof(u64); | |
5519 | ||
5520 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5521 | ||
5522 | if (data->regs_intr.regs) { | |
5523 | u64 mask = event->attr.sample_regs_intr; | |
5524 | ||
5525 | size += hweight64(mask) * sizeof(u64); | |
5526 | } | |
5527 | ||
5528 | header->size += size; | |
5529 | } | |
5622f295 | 5530 | } |
7f453c24 | 5531 | |
21509084 YZ |
5532 | void perf_event_output(struct perf_event *event, |
5533 | struct perf_sample_data *data, | |
5534 | struct pt_regs *regs) | |
5622f295 MM |
5535 | { |
5536 | struct perf_output_handle handle; | |
5537 | struct perf_event_header header; | |
689802b2 | 5538 | |
927c7a9e FW |
5539 | /* protect the callchain buffers */ |
5540 | rcu_read_lock(); | |
5541 | ||
cdd6c482 | 5542 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5543 | |
a7ac67ea | 5544 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5545 | goto exit; |
0322cd6e | 5546 | |
cdd6c482 | 5547 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5548 | |
8a057d84 | 5549 | perf_output_end(&handle); |
927c7a9e FW |
5550 | |
5551 | exit: | |
5552 | rcu_read_unlock(); | |
0322cd6e PZ |
5553 | } |
5554 | ||
38b200d6 | 5555 | /* |
cdd6c482 | 5556 | * read event_id |
38b200d6 PZ |
5557 | */ |
5558 | ||
5559 | struct perf_read_event { | |
5560 | struct perf_event_header header; | |
5561 | ||
5562 | u32 pid; | |
5563 | u32 tid; | |
38b200d6 PZ |
5564 | }; |
5565 | ||
5566 | static void | |
cdd6c482 | 5567 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5568 | struct task_struct *task) |
5569 | { | |
5570 | struct perf_output_handle handle; | |
c980d109 | 5571 | struct perf_sample_data sample; |
dfc65094 | 5572 | struct perf_read_event read_event = { |
38b200d6 | 5573 | .header = { |
cdd6c482 | 5574 | .type = PERF_RECORD_READ, |
38b200d6 | 5575 | .misc = 0, |
c320c7b7 | 5576 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5577 | }, |
cdd6c482 IM |
5578 | .pid = perf_event_pid(event, task), |
5579 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5580 | }; |
3dab77fb | 5581 | int ret; |
38b200d6 | 5582 | |
c980d109 | 5583 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5584 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5585 | if (ret) |
5586 | return; | |
5587 | ||
dfc65094 | 5588 | perf_output_put(&handle, read_event); |
cdd6c482 | 5589 | perf_output_read(&handle, event); |
c980d109 | 5590 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5591 | |
38b200d6 PZ |
5592 | perf_output_end(&handle); |
5593 | } | |
5594 | ||
52d857a8 JO |
5595 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5596 | ||
5597 | static void | |
5598 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5599 | perf_event_aux_output_cb output, |
5600 | void *data) | |
5601 | { | |
5602 | struct perf_event *event; | |
5603 | ||
5604 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5605 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5606 | continue; | |
5607 | if (!event_filter_match(event)) | |
5608 | continue; | |
67516844 | 5609 | output(event, data); |
52d857a8 JO |
5610 | } |
5611 | } | |
5612 | ||
4e93ad60 JO |
5613 | static void |
5614 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5615 | struct perf_event_context *task_ctx) | |
5616 | { | |
5617 | rcu_read_lock(); | |
5618 | preempt_disable(); | |
5619 | perf_event_aux_ctx(task_ctx, output, data); | |
5620 | preempt_enable(); | |
5621 | rcu_read_unlock(); | |
5622 | } | |
5623 | ||
52d857a8 | 5624 | static void |
67516844 | 5625 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5626 | struct perf_event_context *task_ctx) |
5627 | { | |
5628 | struct perf_cpu_context *cpuctx; | |
5629 | struct perf_event_context *ctx; | |
5630 | struct pmu *pmu; | |
5631 | int ctxn; | |
5632 | ||
4e93ad60 JO |
5633 | /* |
5634 | * If we have task_ctx != NULL we only notify | |
5635 | * the task context itself. The task_ctx is set | |
5636 | * only for EXIT events before releasing task | |
5637 | * context. | |
5638 | */ | |
5639 | if (task_ctx) { | |
5640 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5641 | return; | |
5642 | } | |
5643 | ||
52d857a8 JO |
5644 | rcu_read_lock(); |
5645 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5646 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5647 | if (cpuctx->unique_pmu != pmu) | |
5648 | goto next; | |
67516844 | 5649 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5650 | ctxn = pmu->task_ctx_nr; |
5651 | if (ctxn < 0) | |
5652 | goto next; | |
5653 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5654 | if (ctx) | |
67516844 | 5655 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5656 | next: |
5657 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5658 | } | |
52d857a8 JO |
5659 | rcu_read_unlock(); |
5660 | } | |
5661 | ||
60313ebe | 5662 | /* |
9f498cc5 PZ |
5663 | * task tracking -- fork/exit |
5664 | * | |
13d7a241 | 5665 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5666 | */ |
5667 | ||
9f498cc5 | 5668 | struct perf_task_event { |
3a80b4a3 | 5669 | struct task_struct *task; |
cdd6c482 | 5670 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5671 | |
5672 | struct { | |
5673 | struct perf_event_header header; | |
5674 | ||
5675 | u32 pid; | |
5676 | u32 ppid; | |
9f498cc5 PZ |
5677 | u32 tid; |
5678 | u32 ptid; | |
393b2ad8 | 5679 | u64 time; |
cdd6c482 | 5680 | } event_id; |
60313ebe PZ |
5681 | }; |
5682 | ||
67516844 JO |
5683 | static int perf_event_task_match(struct perf_event *event) |
5684 | { | |
13d7a241 SE |
5685 | return event->attr.comm || event->attr.mmap || |
5686 | event->attr.mmap2 || event->attr.mmap_data || | |
5687 | event->attr.task; | |
67516844 JO |
5688 | } |
5689 | ||
cdd6c482 | 5690 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5691 | void *data) |
60313ebe | 5692 | { |
52d857a8 | 5693 | struct perf_task_event *task_event = data; |
60313ebe | 5694 | struct perf_output_handle handle; |
c980d109 | 5695 | struct perf_sample_data sample; |
9f498cc5 | 5696 | struct task_struct *task = task_event->task; |
c980d109 | 5697 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5698 | |
67516844 JO |
5699 | if (!perf_event_task_match(event)) |
5700 | return; | |
5701 | ||
c980d109 | 5702 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5703 | |
c980d109 | 5704 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5705 | task_event->event_id.header.size); |
ef60777c | 5706 | if (ret) |
c980d109 | 5707 | goto out; |
60313ebe | 5708 | |
cdd6c482 IM |
5709 | task_event->event_id.pid = perf_event_pid(event, task); |
5710 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5711 | |
cdd6c482 IM |
5712 | task_event->event_id.tid = perf_event_tid(event, task); |
5713 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5714 | |
34f43927 PZ |
5715 | task_event->event_id.time = perf_event_clock(event); |
5716 | ||
cdd6c482 | 5717 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5718 | |
c980d109 ACM |
5719 | perf_event__output_id_sample(event, &handle, &sample); |
5720 | ||
60313ebe | 5721 | perf_output_end(&handle); |
c980d109 ACM |
5722 | out: |
5723 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5724 | } |
5725 | ||
cdd6c482 IM |
5726 | static void perf_event_task(struct task_struct *task, |
5727 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5728 | int new) |
60313ebe | 5729 | { |
9f498cc5 | 5730 | struct perf_task_event task_event; |
60313ebe | 5731 | |
cdd6c482 IM |
5732 | if (!atomic_read(&nr_comm_events) && |
5733 | !atomic_read(&nr_mmap_events) && | |
5734 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5735 | return; |
5736 | ||
9f498cc5 | 5737 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5738 | .task = task, |
5739 | .task_ctx = task_ctx, | |
cdd6c482 | 5740 | .event_id = { |
60313ebe | 5741 | .header = { |
cdd6c482 | 5742 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5743 | .misc = 0, |
cdd6c482 | 5744 | .size = sizeof(task_event.event_id), |
60313ebe | 5745 | }, |
573402db PZ |
5746 | /* .pid */ |
5747 | /* .ppid */ | |
9f498cc5 PZ |
5748 | /* .tid */ |
5749 | /* .ptid */ | |
34f43927 | 5750 | /* .time */ |
60313ebe PZ |
5751 | }, |
5752 | }; | |
5753 | ||
67516844 | 5754 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5755 | &task_event, |
5756 | task_ctx); | |
9f498cc5 PZ |
5757 | } |
5758 | ||
cdd6c482 | 5759 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5760 | { |
cdd6c482 | 5761 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5762 | } |
5763 | ||
8d1b2d93 PZ |
5764 | /* |
5765 | * comm tracking | |
5766 | */ | |
5767 | ||
5768 | struct perf_comm_event { | |
22a4f650 IM |
5769 | struct task_struct *task; |
5770 | char *comm; | |
8d1b2d93 PZ |
5771 | int comm_size; |
5772 | ||
5773 | struct { | |
5774 | struct perf_event_header header; | |
5775 | ||
5776 | u32 pid; | |
5777 | u32 tid; | |
cdd6c482 | 5778 | } event_id; |
8d1b2d93 PZ |
5779 | }; |
5780 | ||
67516844 JO |
5781 | static int perf_event_comm_match(struct perf_event *event) |
5782 | { | |
5783 | return event->attr.comm; | |
5784 | } | |
5785 | ||
cdd6c482 | 5786 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5787 | void *data) |
8d1b2d93 | 5788 | { |
52d857a8 | 5789 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5790 | struct perf_output_handle handle; |
c980d109 | 5791 | struct perf_sample_data sample; |
cdd6c482 | 5792 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5793 | int ret; |
5794 | ||
67516844 JO |
5795 | if (!perf_event_comm_match(event)) |
5796 | return; | |
5797 | ||
c980d109 ACM |
5798 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5799 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5800 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5801 | |
5802 | if (ret) | |
c980d109 | 5803 | goto out; |
8d1b2d93 | 5804 | |
cdd6c482 IM |
5805 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5806 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5807 | |
cdd6c482 | 5808 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5809 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5810 | comm_event->comm_size); |
c980d109 ACM |
5811 | |
5812 | perf_event__output_id_sample(event, &handle, &sample); | |
5813 | ||
8d1b2d93 | 5814 | perf_output_end(&handle); |
c980d109 ACM |
5815 | out: |
5816 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5817 | } |
5818 | ||
cdd6c482 | 5819 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5820 | { |
413ee3b4 | 5821 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5822 | unsigned int size; |
8d1b2d93 | 5823 | |
413ee3b4 | 5824 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5825 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5826 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5827 | |
5828 | comm_event->comm = comm; | |
5829 | comm_event->comm_size = size; | |
5830 | ||
cdd6c482 | 5831 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5832 | |
67516844 | 5833 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5834 | comm_event, |
5835 | NULL); | |
8d1b2d93 PZ |
5836 | } |
5837 | ||
82b89778 | 5838 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5839 | { |
9ee318a7 PZ |
5840 | struct perf_comm_event comm_event; |
5841 | ||
cdd6c482 | 5842 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5843 | return; |
a63eaf34 | 5844 | |
9ee318a7 | 5845 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5846 | .task = task, |
573402db PZ |
5847 | /* .comm */ |
5848 | /* .comm_size */ | |
cdd6c482 | 5849 | .event_id = { |
573402db | 5850 | .header = { |
cdd6c482 | 5851 | .type = PERF_RECORD_COMM, |
82b89778 | 5852 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5853 | /* .size */ |
5854 | }, | |
5855 | /* .pid */ | |
5856 | /* .tid */ | |
8d1b2d93 PZ |
5857 | }, |
5858 | }; | |
5859 | ||
cdd6c482 | 5860 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5861 | } |
5862 | ||
0a4a9391 PZ |
5863 | /* |
5864 | * mmap tracking | |
5865 | */ | |
5866 | ||
5867 | struct perf_mmap_event { | |
089dd79d PZ |
5868 | struct vm_area_struct *vma; |
5869 | ||
5870 | const char *file_name; | |
5871 | int file_size; | |
13d7a241 SE |
5872 | int maj, min; |
5873 | u64 ino; | |
5874 | u64 ino_generation; | |
f972eb63 | 5875 | u32 prot, flags; |
0a4a9391 PZ |
5876 | |
5877 | struct { | |
5878 | struct perf_event_header header; | |
5879 | ||
5880 | u32 pid; | |
5881 | u32 tid; | |
5882 | u64 start; | |
5883 | u64 len; | |
5884 | u64 pgoff; | |
cdd6c482 | 5885 | } event_id; |
0a4a9391 PZ |
5886 | }; |
5887 | ||
67516844 JO |
5888 | static int perf_event_mmap_match(struct perf_event *event, |
5889 | void *data) | |
5890 | { | |
5891 | struct perf_mmap_event *mmap_event = data; | |
5892 | struct vm_area_struct *vma = mmap_event->vma; | |
5893 | int executable = vma->vm_flags & VM_EXEC; | |
5894 | ||
5895 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5896 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5897 | } |
5898 | ||
cdd6c482 | 5899 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5900 | void *data) |
0a4a9391 | 5901 | { |
52d857a8 | 5902 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5903 | struct perf_output_handle handle; |
c980d109 | 5904 | struct perf_sample_data sample; |
cdd6c482 | 5905 | int size = mmap_event->event_id.header.size; |
c980d109 | 5906 | int ret; |
0a4a9391 | 5907 | |
67516844 JO |
5908 | if (!perf_event_mmap_match(event, data)) |
5909 | return; | |
5910 | ||
13d7a241 SE |
5911 | if (event->attr.mmap2) { |
5912 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5913 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5914 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5915 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5916 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5917 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5918 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5919 | } |
5920 | ||
c980d109 ACM |
5921 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5922 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5923 | mmap_event->event_id.header.size); |
0a4a9391 | 5924 | if (ret) |
c980d109 | 5925 | goto out; |
0a4a9391 | 5926 | |
cdd6c482 IM |
5927 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5928 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5929 | |
cdd6c482 | 5930 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5931 | |
5932 | if (event->attr.mmap2) { | |
5933 | perf_output_put(&handle, mmap_event->maj); | |
5934 | perf_output_put(&handle, mmap_event->min); | |
5935 | perf_output_put(&handle, mmap_event->ino); | |
5936 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5937 | perf_output_put(&handle, mmap_event->prot); |
5938 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5939 | } |
5940 | ||
76369139 | 5941 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5942 | mmap_event->file_size); |
c980d109 ACM |
5943 | |
5944 | perf_event__output_id_sample(event, &handle, &sample); | |
5945 | ||
78d613eb | 5946 | perf_output_end(&handle); |
c980d109 ACM |
5947 | out: |
5948 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5949 | } |
5950 | ||
cdd6c482 | 5951 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5952 | { |
089dd79d PZ |
5953 | struct vm_area_struct *vma = mmap_event->vma; |
5954 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5955 | int maj = 0, min = 0; |
5956 | u64 ino = 0, gen = 0; | |
f972eb63 | 5957 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5958 | unsigned int size; |
5959 | char tmp[16]; | |
5960 | char *buf = NULL; | |
2c42cfbf | 5961 | char *name; |
413ee3b4 | 5962 | |
0a4a9391 | 5963 | if (file) { |
13d7a241 SE |
5964 | struct inode *inode; |
5965 | dev_t dev; | |
3ea2f2b9 | 5966 | |
2c42cfbf | 5967 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5968 | if (!buf) { |
c7e548b4 ON |
5969 | name = "//enomem"; |
5970 | goto cpy_name; | |
0a4a9391 | 5971 | } |
413ee3b4 | 5972 | /* |
3ea2f2b9 | 5973 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5974 | * need to add enough zero bytes after the string to handle |
5975 | * the 64bit alignment we do later. | |
5976 | */ | |
9bf39ab2 | 5977 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5978 | if (IS_ERR(name)) { |
c7e548b4 ON |
5979 | name = "//toolong"; |
5980 | goto cpy_name; | |
0a4a9391 | 5981 | } |
13d7a241 SE |
5982 | inode = file_inode(vma->vm_file); |
5983 | dev = inode->i_sb->s_dev; | |
5984 | ino = inode->i_ino; | |
5985 | gen = inode->i_generation; | |
5986 | maj = MAJOR(dev); | |
5987 | min = MINOR(dev); | |
f972eb63 PZ |
5988 | |
5989 | if (vma->vm_flags & VM_READ) | |
5990 | prot |= PROT_READ; | |
5991 | if (vma->vm_flags & VM_WRITE) | |
5992 | prot |= PROT_WRITE; | |
5993 | if (vma->vm_flags & VM_EXEC) | |
5994 | prot |= PROT_EXEC; | |
5995 | ||
5996 | if (vma->vm_flags & VM_MAYSHARE) | |
5997 | flags = MAP_SHARED; | |
5998 | else | |
5999 | flags = MAP_PRIVATE; | |
6000 | ||
6001 | if (vma->vm_flags & VM_DENYWRITE) | |
6002 | flags |= MAP_DENYWRITE; | |
6003 | if (vma->vm_flags & VM_MAYEXEC) | |
6004 | flags |= MAP_EXECUTABLE; | |
6005 | if (vma->vm_flags & VM_LOCKED) | |
6006 | flags |= MAP_LOCKED; | |
6007 | if (vma->vm_flags & VM_HUGETLB) | |
6008 | flags |= MAP_HUGETLB; | |
6009 | ||
c7e548b4 | 6010 | goto got_name; |
0a4a9391 | 6011 | } else { |
fbe26abe JO |
6012 | if (vma->vm_ops && vma->vm_ops->name) { |
6013 | name = (char *) vma->vm_ops->name(vma); | |
6014 | if (name) | |
6015 | goto cpy_name; | |
6016 | } | |
6017 | ||
2c42cfbf | 6018 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6019 | if (name) |
6020 | goto cpy_name; | |
089dd79d | 6021 | |
32c5fb7e | 6022 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6023 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6024 | name = "[heap]"; |
6025 | goto cpy_name; | |
32c5fb7e ON |
6026 | } |
6027 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6028 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6029 | name = "[stack]"; |
6030 | goto cpy_name; | |
089dd79d PZ |
6031 | } |
6032 | ||
c7e548b4 ON |
6033 | name = "//anon"; |
6034 | goto cpy_name; | |
0a4a9391 PZ |
6035 | } |
6036 | ||
c7e548b4 ON |
6037 | cpy_name: |
6038 | strlcpy(tmp, name, sizeof(tmp)); | |
6039 | name = tmp; | |
0a4a9391 | 6040 | got_name: |
2c42cfbf PZ |
6041 | /* |
6042 | * Since our buffer works in 8 byte units we need to align our string | |
6043 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6044 | * zero'd out to avoid leaking random bits to userspace. | |
6045 | */ | |
6046 | size = strlen(name)+1; | |
6047 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6048 | name[size++] = '\0'; | |
0a4a9391 PZ |
6049 | |
6050 | mmap_event->file_name = name; | |
6051 | mmap_event->file_size = size; | |
13d7a241 SE |
6052 | mmap_event->maj = maj; |
6053 | mmap_event->min = min; | |
6054 | mmap_event->ino = ino; | |
6055 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6056 | mmap_event->prot = prot; |
6057 | mmap_event->flags = flags; | |
0a4a9391 | 6058 | |
2fe85427 SE |
6059 | if (!(vma->vm_flags & VM_EXEC)) |
6060 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6061 | ||
cdd6c482 | 6062 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6063 | |
67516844 | 6064 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6065 | mmap_event, |
6066 | NULL); | |
665c2142 | 6067 | |
0a4a9391 PZ |
6068 | kfree(buf); |
6069 | } | |
6070 | ||
3af9e859 | 6071 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6072 | { |
9ee318a7 PZ |
6073 | struct perf_mmap_event mmap_event; |
6074 | ||
cdd6c482 | 6075 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6076 | return; |
6077 | ||
6078 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6079 | .vma = vma, |
573402db PZ |
6080 | /* .file_name */ |
6081 | /* .file_size */ | |
cdd6c482 | 6082 | .event_id = { |
573402db | 6083 | .header = { |
cdd6c482 | 6084 | .type = PERF_RECORD_MMAP, |
39447b38 | 6085 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6086 | /* .size */ |
6087 | }, | |
6088 | /* .pid */ | |
6089 | /* .tid */ | |
089dd79d PZ |
6090 | .start = vma->vm_start, |
6091 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6092 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6093 | }, |
13d7a241 SE |
6094 | /* .maj (attr_mmap2 only) */ |
6095 | /* .min (attr_mmap2 only) */ | |
6096 | /* .ino (attr_mmap2 only) */ | |
6097 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6098 | /* .prot (attr_mmap2 only) */ |
6099 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6100 | }; |
6101 | ||
cdd6c482 | 6102 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6103 | } |
6104 | ||
68db7e98 AS |
6105 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6106 | unsigned long size, u64 flags) | |
6107 | { | |
6108 | struct perf_output_handle handle; | |
6109 | struct perf_sample_data sample; | |
6110 | struct perf_aux_event { | |
6111 | struct perf_event_header header; | |
6112 | u64 offset; | |
6113 | u64 size; | |
6114 | u64 flags; | |
6115 | } rec = { | |
6116 | .header = { | |
6117 | .type = PERF_RECORD_AUX, | |
6118 | .misc = 0, | |
6119 | .size = sizeof(rec), | |
6120 | }, | |
6121 | .offset = head, | |
6122 | .size = size, | |
6123 | .flags = flags, | |
6124 | }; | |
6125 | int ret; | |
6126 | ||
6127 | perf_event_header__init_id(&rec.header, &sample, event); | |
6128 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6129 | ||
6130 | if (ret) | |
6131 | return; | |
6132 | ||
6133 | perf_output_put(&handle, rec); | |
6134 | perf_event__output_id_sample(event, &handle, &sample); | |
6135 | ||
6136 | perf_output_end(&handle); | |
6137 | } | |
6138 | ||
f38b0dbb KL |
6139 | /* |
6140 | * Lost/dropped samples logging | |
6141 | */ | |
6142 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6143 | { | |
6144 | struct perf_output_handle handle; | |
6145 | struct perf_sample_data sample; | |
6146 | int ret; | |
6147 | ||
6148 | struct { | |
6149 | struct perf_event_header header; | |
6150 | u64 lost; | |
6151 | } lost_samples_event = { | |
6152 | .header = { | |
6153 | .type = PERF_RECORD_LOST_SAMPLES, | |
6154 | .misc = 0, | |
6155 | .size = sizeof(lost_samples_event), | |
6156 | }, | |
6157 | .lost = lost, | |
6158 | }; | |
6159 | ||
6160 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6161 | ||
6162 | ret = perf_output_begin(&handle, event, | |
6163 | lost_samples_event.header.size); | |
6164 | if (ret) | |
6165 | return; | |
6166 | ||
6167 | perf_output_put(&handle, lost_samples_event); | |
6168 | perf_event__output_id_sample(event, &handle, &sample); | |
6169 | perf_output_end(&handle); | |
6170 | } | |
6171 | ||
45ac1403 AH |
6172 | /* |
6173 | * context_switch tracking | |
6174 | */ | |
6175 | ||
6176 | struct perf_switch_event { | |
6177 | struct task_struct *task; | |
6178 | struct task_struct *next_prev; | |
6179 | ||
6180 | struct { | |
6181 | struct perf_event_header header; | |
6182 | u32 next_prev_pid; | |
6183 | u32 next_prev_tid; | |
6184 | } event_id; | |
6185 | }; | |
6186 | ||
6187 | static int perf_event_switch_match(struct perf_event *event) | |
6188 | { | |
6189 | return event->attr.context_switch; | |
6190 | } | |
6191 | ||
6192 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6193 | { | |
6194 | struct perf_switch_event *se = data; | |
6195 | struct perf_output_handle handle; | |
6196 | struct perf_sample_data sample; | |
6197 | int ret; | |
6198 | ||
6199 | if (!perf_event_switch_match(event)) | |
6200 | return; | |
6201 | ||
6202 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6203 | if (event->ctx->task) { | |
6204 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6205 | se->event_id.header.size = sizeof(se->event_id.header); | |
6206 | } else { | |
6207 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6208 | se->event_id.header.size = sizeof(se->event_id); | |
6209 | se->event_id.next_prev_pid = | |
6210 | perf_event_pid(event, se->next_prev); | |
6211 | se->event_id.next_prev_tid = | |
6212 | perf_event_tid(event, se->next_prev); | |
6213 | } | |
6214 | ||
6215 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6216 | ||
6217 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6218 | if (ret) | |
6219 | return; | |
6220 | ||
6221 | if (event->ctx->task) | |
6222 | perf_output_put(&handle, se->event_id.header); | |
6223 | else | |
6224 | perf_output_put(&handle, se->event_id); | |
6225 | ||
6226 | perf_event__output_id_sample(event, &handle, &sample); | |
6227 | ||
6228 | perf_output_end(&handle); | |
6229 | } | |
6230 | ||
6231 | static void perf_event_switch(struct task_struct *task, | |
6232 | struct task_struct *next_prev, bool sched_in) | |
6233 | { | |
6234 | struct perf_switch_event switch_event; | |
6235 | ||
6236 | /* N.B. caller checks nr_switch_events != 0 */ | |
6237 | ||
6238 | switch_event = (struct perf_switch_event){ | |
6239 | .task = task, | |
6240 | .next_prev = next_prev, | |
6241 | .event_id = { | |
6242 | .header = { | |
6243 | /* .type */ | |
6244 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6245 | /* .size */ | |
6246 | }, | |
6247 | /* .next_prev_pid */ | |
6248 | /* .next_prev_tid */ | |
6249 | }, | |
6250 | }; | |
6251 | ||
6252 | perf_event_aux(perf_event_switch_output, | |
6253 | &switch_event, | |
6254 | NULL); | |
6255 | } | |
6256 | ||
a78ac325 PZ |
6257 | /* |
6258 | * IRQ throttle logging | |
6259 | */ | |
6260 | ||
cdd6c482 | 6261 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6262 | { |
6263 | struct perf_output_handle handle; | |
c980d109 | 6264 | struct perf_sample_data sample; |
a78ac325 PZ |
6265 | int ret; |
6266 | ||
6267 | struct { | |
6268 | struct perf_event_header header; | |
6269 | u64 time; | |
cca3f454 | 6270 | u64 id; |
7f453c24 | 6271 | u64 stream_id; |
a78ac325 PZ |
6272 | } throttle_event = { |
6273 | .header = { | |
cdd6c482 | 6274 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6275 | .misc = 0, |
6276 | .size = sizeof(throttle_event), | |
6277 | }, | |
34f43927 | 6278 | .time = perf_event_clock(event), |
cdd6c482 IM |
6279 | .id = primary_event_id(event), |
6280 | .stream_id = event->id, | |
a78ac325 PZ |
6281 | }; |
6282 | ||
966ee4d6 | 6283 | if (enable) |
cdd6c482 | 6284 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6285 | |
c980d109 ACM |
6286 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6287 | ||
6288 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6289 | throttle_event.header.size); |
a78ac325 PZ |
6290 | if (ret) |
6291 | return; | |
6292 | ||
6293 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6294 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6295 | perf_output_end(&handle); |
6296 | } | |
6297 | ||
ec0d7729 AS |
6298 | static void perf_log_itrace_start(struct perf_event *event) |
6299 | { | |
6300 | struct perf_output_handle handle; | |
6301 | struct perf_sample_data sample; | |
6302 | struct perf_aux_event { | |
6303 | struct perf_event_header header; | |
6304 | u32 pid; | |
6305 | u32 tid; | |
6306 | } rec; | |
6307 | int ret; | |
6308 | ||
6309 | if (event->parent) | |
6310 | event = event->parent; | |
6311 | ||
6312 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6313 | event->hw.itrace_started) | |
6314 | return; | |
6315 | ||
ec0d7729 AS |
6316 | rec.header.type = PERF_RECORD_ITRACE_START; |
6317 | rec.header.misc = 0; | |
6318 | rec.header.size = sizeof(rec); | |
6319 | rec.pid = perf_event_pid(event, current); | |
6320 | rec.tid = perf_event_tid(event, current); | |
6321 | ||
6322 | perf_event_header__init_id(&rec.header, &sample, event); | |
6323 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6324 | ||
6325 | if (ret) | |
6326 | return; | |
6327 | ||
6328 | perf_output_put(&handle, rec); | |
6329 | perf_event__output_id_sample(event, &handle, &sample); | |
6330 | ||
6331 | perf_output_end(&handle); | |
6332 | } | |
6333 | ||
f6c7d5fe | 6334 | /* |
cdd6c482 | 6335 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6336 | */ |
6337 | ||
a8b0ca17 | 6338 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6339 | int throttle, struct perf_sample_data *data, |
6340 | struct pt_regs *regs) | |
f6c7d5fe | 6341 | { |
cdd6c482 IM |
6342 | int events = atomic_read(&event->event_limit); |
6343 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6344 | u64 seq; |
79f14641 PZ |
6345 | int ret = 0; |
6346 | ||
96398826 PZ |
6347 | /* |
6348 | * Non-sampling counters might still use the PMI to fold short | |
6349 | * hardware counters, ignore those. | |
6350 | */ | |
6351 | if (unlikely(!is_sampling_event(event))) | |
6352 | return 0; | |
6353 | ||
e050e3f0 SE |
6354 | seq = __this_cpu_read(perf_throttled_seq); |
6355 | if (seq != hwc->interrupts_seq) { | |
6356 | hwc->interrupts_seq = seq; | |
6357 | hwc->interrupts = 1; | |
6358 | } else { | |
6359 | hwc->interrupts++; | |
6360 | if (unlikely(throttle | |
6361 | && hwc->interrupts >= max_samples_per_tick)) { | |
6362 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6363 | hwc->interrupts = MAX_INTERRUPTS; |
6364 | perf_log_throttle(event, 0); | |
d84153d6 | 6365 | tick_nohz_full_kick(); |
a78ac325 PZ |
6366 | ret = 1; |
6367 | } | |
e050e3f0 | 6368 | } |
60db5e09 | 6369 | |
cdd6c482 | 6370 | if (event->attr.freq) { |
def0a9b2 | 6371 | u64 now = perf_clock(); |
abd50713 | 6372 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6373 | |
abd50713 | 6374 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6375 | |
abd50713 | 6376 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6377 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6378 | } |
6379 | ||
2023b359 PZ |
6380 | /* |
6381 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6382 | * events |
2023b359 PZ |
6383 | */ |
6384 | ||
cdd6c482 IM |
6385 | event->pending_kill = POLL_IN; |
6386 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6387 | ret = 1; |
cdd6c482 | 6388 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6389 | event->pending_disable = 1; |
6390 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6391 | } |
6392 | ||
453f19ee | 6393 | if (event->overflow_handler) |
a8b0ca17 | 6394 | event->overflow_handler(event, data, regs); |
453f19ee | 6395 | else |
a8b0ca17 | 6396 | perf_event_output(event, data, regs); |
453f19ee | 6397 | |
fed66e2c | 6398 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6399 | event->pending_wakeup = 1; |
6400 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6401 | } |
6402 | ||
79f14641 | 6403 | return ret; |
f6c7d5fe PZ |
6404 | } |
6405 | ||
a8b0ca17 | 6406 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6407 | struct perf_sample_data *data, |
6408 | struct pt_regs *regs) | |
850bc73f | 6409 | { |
a8b0ca17 | 6410 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6411 | } |
6412 | ||
15dbf27c | 6413 | /* |
cdd6c482 | 6414 | * Generic software event infrastructure |
15dbf27c PZ |
6415 | */ |
6416 | ||
b28ab83c PZ |
6417 | struct swevent_htable { |
6418 | struct swevent_hlist *swevent_hlist; | |
6419 | struct mutex hlist_mutex; | |
6420 | int hlist_refcount; | |
6421 | ||
6422 | /* Recursion avoidance in each contexts */ | |
6423 | int recursion[PERF_NR_CONTEXTS]; | |
6424 | }; | |
6425 | ||
6426 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6427 | ||
7b4b6658 | 6428 | /* |
cdd6c482 IM |
6429 | * We directly increment event->count and keep a second value in |
6430 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6431 | * is kept in the range [-sample_period, 0] so that we can use the |
6432 | * sign as trigger. | |
6433 | */ | |
6434 | ||
ab573844 | 6435 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6436 | { |
cdd6c482 | 6437 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6438 | u64 period = hwc->last_period; |
6439 | u64 nr, offset; | |
6440 | s64 old, val; | |
6441 | ||
6442 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6443 | |
6444 | again: | |
e7850595 | 6445 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6446 | if (val < 0) |
6447 | return 0; | |
15dbf27c | 6448 | |
7b4b6658 PZ |
6449 | nr = div64_u64(period + val, period); |
6450 | offset = nr * period; | |
6451 | val -= offset; | |
e7850595 | 6452 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6453 | goto again; |
15dbf27c | 6454 | |
7b4b6658 | 6455 | return nr; |
15dbf27c PZ |
6456 | } |
6457 | ||
0cff784a | 6458 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6459 | struct perf_sample_data *data, |
5622f295 | 6460 | struct pt_regs *regs) |
15dbf27c | 6461 | { |
cdd6c482 | 6462 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6463 | int throttle = 0; |
15dbf27c | 6464 | |
0cff784a PZ |
6465 | if (!overflow) |
6466 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6467 | |
7b4b6658 PZ |
6468 | if (hwc->interrupts == MAX_INTERRUPTS) |
6469 | return; | |
15dbf27c | 6470 | |
7b4b6658 | 6471 | for (; overflow; overflow--) { |
a8b0ca17 | 6472 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6473 | data, regs)) { |
7b4b6658 PZ |
6474 | /* |
6475 | * We inhibit the overflow from happening when | |
6476 | * hwc->interrupts == MAX_INTERRUPTS. | |
6477 | */ | |
6478 | break; | |
6479 | } | |
cf450a73 | 6480 | throttle = 1; |
7b4b6658 | 6481 | } |
15dbf27c PZ |
6482 | } |
6483 | ||
a4eaf7f1 | 6484 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6485 | struct perf_sample_data *data, |
5622f295 | 6486 | struct pt_regs *regs) |
7b4b6658 | 6487 | { |
cdd6c482 | 6488 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6489 | |
e7850595 | 6490 | local64_add(nr, &event->count); |
d6d020e9 | 6491 | |
0cff784a PZ |
6492 | if (!regs) |
6493 | return; | |
6494 | ||
6c7e550f | 6495 | if (!is_sampling_event(event)) |
7b4b6658 | 6496 | return; |
d6d020e9 | 6497 | |
5d81e5cf AV |
6498 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6499 | data->period = nr; | |
6500 | return perf_swevent_overflow(event, 1, data, regs); | |
6501 | } else | |
6502 | data->period = event->hw.last_period; | |
6503 | ||
0cff784a | 6504 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6505 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6506 | |
e7850595 | 6507 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6508 | return; |
df1a132b | 6509 | |
a8b0ca17 | 6510 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6511 | } |
6512 | ||
f5ffe02e FW |
6513 | static int perf_exclude_event(struct perf_event *event, |
6514 | struct pt_regs *regs) | |
6515 | { | |
a4eaf7f1 | 6516 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6517 | return 1; |
a4eaf7f1 | 6518 | |
f5ffe02e FW |
6519 | if (regs) { |
6520 | if (event->attr.exclude_user && user_mode(regs)) | |
6521 | return 1; | |
6522 | ||
6523 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6524 | return 1; | |
6525 | } | |
6526 | ||
6527 | return 0; | |
6528 | } | |
6529 | ||
cdd6c482 | 6530 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6531 | enum perf_type_id type, |
6fb2915d LZ |
6532 | u32 event_id, |
6533 | struct perf_sample_data *data, | |
6534 | struct pt_regs *regs) | |
15dbf27c | 6535 | { |
cdd6c482 | 6536 | if (event->attr.type != type) |
a21ca2ca | 6537 | return 0; |
f5ffe02e | 6538 | |
cdd6c482 | 6539 | if (event->attr.config != event_id) |
15dbf27c PZ |
6540 | return 0; |
6541 | ||
f5ffe02e FW |
6542 | if (perf_exclude_event(event, regs)) |
6543 | return 0; | |
15dbf27c PZ |
6544 | |
6545 | return 1; | |
6546 | } | |
6547 | ||
76e1d904 FW |
6548 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6549 | { | |
6550 | u64 val = event_id | (type << 32); | |
6551 | ||
6552 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6553 | } | |
6554 | ||
49f135ed FW |
6555 | static inline struct hlist_head * |
6556 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6557 | { |
49f135ed FW |
6558 | u64 hash = swevent_hash(type, event_id); |
6559 | ||
6560 | return &hlist->heads[hash]; | |
6561 | } | |
76e1d904 | 6562 | |
49f135ed FW |
6563 | /* For the read side: events when they trigger */ |
6564 | static inline struct hlist_head * | |
b28ab83c | 6565 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6566 | { |
6567 | struct swevent_hlist *hlist; | |
76e1d904 | 6568 | |
b28ab83c | 6569 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6570 | if (!hlist) |
6571 | return NULL; | |
6572 | ||
49f135ed FW |
6573 | return __find_swevent_head(hlist, type, event_id); |
6574 | } | |
6575 | ||
6576 | /* For the event head insertion and removal in the hlist */ | |
6577 | static inline struct hlist_head * | |
b28ab83c | 6578 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6579 | { |
6580 | struct swevent_hlist *hlist; | |
6581 | u32 event_id = event->attr.config; | |
6582 | u64 type = event->attr.type; | |
6583 | ||
6584 | /* | |
6585 | * Event scheduling is always serialized against hlist allocation | |
6586 | * and release. Which makes the protected version suitable here. | |
6587 | * The context lock guarantees that. | |
6588 | */ | |
b28ab83c | 6589 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6590 | lockdep_is_held(&event->ctx->lock)); |
6591 | if (!hlist) | |
6592 | return NULL; | |
6593 | ||
6594 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6595 | } |
6596 | ||
6597 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6598 | u64 nr, |
76e1d904 FW |
6599 | struct perf_sample_data *data, |
6600 | struct pt_regs *regs) | |
15dbf27c | 6601 | { |
4a32fea9 | 6602 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6603 | struct perf_event *event; |
76e1d904 | 6604 | struct hlist_head *head; |
15dbf27c | 6605 | |
76e1d904 | 6606 | rcu_read_lock(); |
b28ab83c | 6607 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6608 | if (!head) |
6609 | goto end; | |
6610 | ||
b67bfe0d | 6611 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6612 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6613 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6614 | } |
76e1d904 FW |
6615 | end: |
6616 | rcu_read_unlock(); | |
15dbf27c PZ |
6617 | } |
6618 | ||
86038c5e PZI |
6619 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6620 | ||
4ed7c92d | 6621 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6622 | { |
4a32fea9 | 6623 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6624 | |
b28ab83c | 6625 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6626 | } |
645e8cc0 | 6627 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6628 | |
fa9f90be | 6629 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6630 | { |
4a32fea9 | 6631 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6632 | |
b28ab83c | 6633 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6634 | } |
15dbf27c | 6635 | |
86038c5e | 6636 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6637 | { |
a4234bfc | 6638 | struct perf_sample_data data; |
4ed7c92d | 6639 | |
86038c5e | 6640 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6641 | return; |
a4234bfc | 6642 | |
fd0d000b | 6643 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6644 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6645 | } |
6646 | ||
6647 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6648 | { | |
6649 | int rctx; | |
6650 | ||
6651 | preempt_disable_notrace(); | |
6652 | rctx = perf_swevent_get_recursion_context(); | |
6653 | if (unlikely(rctx < 0)) | |
6654 | goto fail; | |
6655 | ||
6656 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6657 | |
6658 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6659 | fail: |
1c024eca | 6660 | preempt_enable_notrace(); |
b8e83514 PZ |
6661 | } |
6662 | ||
cdd6c482 | 6663 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6664 | { |
15dbf27c PZ |
6665 | } |
6666 | ||
a4eaf7f1 | 6667 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6668 | { |
4a32fea9 | 6669 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6670 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6671 | struct hlist_head *head; |
6672 | ||
6c7e550f | 6673 | if (is_sampling_event(event)) { |
7b4b6658 | 6674 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6675 | perf_swevent_set_period(event); |
7b4b6658 | 6676 | } |
76e1d904 | 6677 | |
a4eaf7f1 PZ |
6678 | hwc->state = !(flags & PERF_EF_START); |
6679 | ||
b28ab83c | 6680 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6681 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6682 | return -EINVAL; |
6683 | ||
6684 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6685 | perf_event_update_userpage(event); |
76e1d904 | 6686 | |
15dbf27c PZ |
6687 | return 0; |
6688 | } | |
6689 | ||
a4eaf7f1 | 6690 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6691 | { |
76e1d904 | 6692 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6693 | } |
6694 | ||
a4eaf7f1 | 6695 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6696 | { |
a4eaf7f1 | 6697 | event->hw.state = 0; |
d6d020e9 | 6698 | } |
aa9c4c0f | 6699 | |
a4eaf7f1 | 6700 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6701 | { |
a4eaf7f1 | 6702 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6703 | } |
6704 | ||
49f135ed FW |
6705 | /* Deref the hlist from the update side */ |
6706 | static inline struct swevent_hlist * | |
b28ab83c | 6707 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6708 | { |
b28ab83c PZ |
6709 | return rcu_dereference_protected(swhash->swevent_hlist, |
6710 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6711 | } |
6712 | ||
b28ab83c | 6713 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6714 | { |
b28ab83c | 6715 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6716 | |
49f135ed | 6717 | if (!hlist) |
76e1d904 FW |
6718 | return; |
6719 | ||
70691d4a | 6720 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6721 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6722 | } |
6723 | ||
6724 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6725 | { | |
b28ab83c | 6726 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6727 | |
b28ab83c | 6728 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6729 | |
b28ab83c PZ |
6730 | if (!--swhash->hlist_refcount) |
6731 | swevent_hlist_release(swhash); | |
76e1d904 | 6732 | |
b28ab83c | 6733 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6734 | } |
6735 | ||
6736 | static void swevent_hlist_put(struct perf_event *event) | |
6737 | { | |
6738 | int cpu; | |
6739 | ||
76e1d904 FW |
6740 | for_each_possible_cpu(cpu) |
6741 | swevent_hlist_put_cpu(event, cpu); | |
6742 | } | |
6743 | ||
6744 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6745 | { | |
b28ab83c | 6746 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6747 | int err = 0; |
6748 | ||
b28ab83c | 6749 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6750 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6751 | struct swevent_hlist *hlist; |
6752 | ||
6753 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6754 | if (!hlist) { | |
6755 | err = -ENOMEM; | |
6756 | goto exit; | |
6757 | } | |
b28ab83c | 6758 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6759 | } |
b28ab83c | 6760 | swhash->hlist_refcount++; |
9ed6060d | 6761 | exit: |
b28ab83c | 6762 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6763 | |
6764 | return err; | |
6765 | } | |
6766 | ||
6767 | static int swevent_hlist_get(struct perf_event *event) | |
6768 | { | |
6769 | int err; | |
6770 | int cpu, failed_cpu; | |
6771 | ||
76e1d904 FW |
6772 | get_online_cpus(); |
6773 | for_each_possible_cpu(cpu) { | |
6774 | err = swevent_hlist_get_cpu(event, cpu); | |
6775 | if (err) { | |
6776 | failed_cpu = cpu; | |
6777 | goto fail; | |
6778 | } | |
6779 | } | |
6780 | put_online_cpus(); | |
6781 | ||
6782 | return 0; | |
9ed6060d | 6783 | fail: |
76e1d904 FW |
6784 | for_each_possible_cpu(cpu) { |
6785 | if (cpu == failed_cpu) | |
6786 | break; | |
6787 | swevent_hlist_put_cpu(event, cpu); | |
6788 | } | |
6789 | ||
6790 | put_online_cpus(); | |
6791 | return err; | |
6792 | } | |
6793 | ||
c5905afb | 6794 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6795 | |
b0a873eb PZ |
6796 | static void sw_perf_event_destroy(struct perf_event *event) |
6797 | { | |
6798 | u64 event_id = event->attr.config; | |
95476b64 | 6799 | |
b0a873eb PZ |
6800 | WARN_ON(event->parent); |
6801 | ||
c5905afb | 6802 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6803 | swevent_hlist_put(event); |
6804 | } | |
6805 | ||
6806 | static int perf_swevent_init(struct perf_event *event) | |
6807 | { | |
8176cced | 6808 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6809 | |
6810 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6811 | return -ENOENT; | |
6812 | ||
2481c5fa SE |
6813 | /* |
6814 | * no branch sampling for software events | |
6815 | */ | |
6816 | if (has_branch_stack(event)) | |
6817 | return -EOPNOTSUPP; | |
6818 | ||
b0a873eb PZ |
6819 | switch (event_id) { |
6820 | case PERF_COUNT_SW_CPU_CLOCK: | |
6821 | case PERF_COUNT_SW_TASK_CLOCK: | |
6822 | return -ENOENT; | |
6823 | ||
6824 | default: | |
6825 | break; | |
6826 | } | |
6827 | ||
ce677831 | 6828 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6829 | return -ENOENT; |
6830 | ||
6831 | if (!event->parent) { | |
6832 | int err; | |
6833 | ||
6834 | err = swevent_hlist_get(event); | |
6835 | if (err) | |
6836 | return err; | |
6837 | ||
c5905afb | 6838 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6839 | event->destroy = sw_perf_event_destroy; |
6840 | } | |
6841 | ||
6842 | return 0; | |
6843 | } | |
6844 | ||
6845 | static struct pmu perf_swevent = { | |
89a1e187 | 6846 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6847 | |
34f43927 PZ |
6848 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6849 | ||
b0a873eb | 6850 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6851 | .add = perf_swevent_add, |
6852 | .del = perf_swevent_del, | |
6853 | .start = perf_swevent_start, | |
6854 | .stop = perf_swevent_stop, | |
1c024eca | 6855 | .read = perf_swevent_read, |
1c024eca PZ |
6856 | }; |
6857 | ||
b0a873eb PZ |
6858 | #ifdef CONFIG_EVENT_TRACING |
6859 | ||
1c024eca PZ |
6860 | static int perf_tp_filter_match(struct perf_event *event, |
6861 | struct perf_sample_data *data) | |
6862 | { | |
6863 | void *record = data->raw->data; | |
6864 | ||
b71b437e PZ |
6865 | /* only top level events have filters set */ |
6866 | if (event->parent) | |
6867 | event = event->parent; | |
6868 | ||
1c024eca PZ |
6869 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6870 | return 1; | |
6871 | return 0; | |
6872 | } | |
6873 | ||
6874 | static int perf_tp_event_match(struct perf_event *event, | |
6875 | struct perf_sample_data *data, | |
6876 | struct pt_regs *regs) | |
6877 | { | |
a0f7d0f7 FW |
6878 | if (event->hw.state & PERF_HES_STOPPED) |
6879 | return 0; | |
580d607c PZ |
6880 | /* |
6881 | * All tracepoints are from kernel-space. | |
6882 | */ | |
6883 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6884 | return 0; |
6885 | ||
6886 | if (!perf_tp_filter_match(event, data)) | |
6887 | return 0; | |
6888 | ||
6889 | return 1; | |
6890 | } | |
6891 | ||
6892 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6893 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6894 | struct task_struct *task) | |
95476b64 FW |
6895 | { |
6896 | struct perf_sample_data data; | |
1c024eca | 6897 | struct perf_event *event; |
1c024eca | 6898 | |
95476b64 FW |
6899 | struct perf_raw_record raw = { |
6900 | .size = entry_size, | |
6901 | .data = record, | |
6902 | }; | |
6903 | ||
fd0d000b | 6904 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6905 | data.raw = &raw; |
6906 | ||
b67bfe0d | 6907 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6908 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6909 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6910 | } |
ecc55f84 | 6911 | |
e6dab5ff AV |
6912 | /* |
6913 | * If we got specified a target task, also iterate its context and | |
6914 | * deliver this event there too. | |
6915 | */ | |
6916 | if (task && task != current) { | |
6917 | struct perf_event_context *ctx; | |
6918 | struct trace_entry *entry = record; | |
6919 | ||
6920 | rcu_read_lock(); | |
6921 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6922 | if (!ctx) | |
6923 | goto unlock; | |
6924 | ||
6925 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6926 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6927 | continue; | |
6928 | if (event->attr.config != entry->type) | |
6929 | continue; | |
6930 | if (perf_tp_event_match(event, &data, regs)) | |
6931 | perf_swevent_event(event, count, &data, regs); | |
6932 | } | |
6933 | unlock: | |
6934 | rcu_read_unlock(); | |
6935 | } | |
6936 | ||
ecc55f84 | 6937 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6938 | } |
6939 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6940 | ||
cdd6c482 | 6941 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6942 | { |
1c024eca | 6943 | perf_trace_destroy(event); |
e077df4f PZ |
6944 | } |
6945 | ||
b0a873eb | 6946 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6947 | { |
76e1d904 FW |
6948 | int err; |
6949 | ||
b0a873eb PZ |
6950 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6951 | return -ENOENT; | |
6952 | ||
2481c5fa SE |
6953 | /* |
6954 | * no branch sampling for tracepoint events | |
6955 | */ | |
6956 | if (has_branch_stack(event)) | |
6957 | return -EOPNOTSUPP; | |
6958 | ||
1c024eca PZ |
6959 | err = perf_trace_init(event); |
6960 | if (err) | |
b0a873eb | 6961 | return err; |
e077df4f | 6962 | |
cdd6c482 | 6963 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6964 | |
b0a873eb PZ |
6965 | return 0; |
6966 | } | |
6967 | ||
6968 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6969 | .task_ctx_nr = perf_sw_context, |
6970 | ||
b0a873eb | 6971 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6972 | .add = perf_trace_add, |
6973 | .del = perf_trace_del, | |
6974 | .start = perf_swevent_start, | |
6975 | .stop = perf_swevent_stop, | |
b0a873eb | 6976 | .read = perf_swevent_read, |
b0a873eb PZ |
6977 | }; |
6978 | ||
6979 | static inline void perf_tp_register(void) | |
6980 | { | |
2e80a82a | 6981 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6982 | } |
6fb2915d LZ |
6983 | |
6984 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6985 | { | |
6986 | char *filter_str; | |
6987 | int ret; | |
6988 | ||
6989 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6990 | return -EINVAL; | |
6991 | ||
6992 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6993 | if (IS_ERR(filter_str)) | |
6994 | return PTR_ERR(filter_str); | |
6995 | ||
6996 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6997 | ||
6998 | kfree(filter_str); | |
6999 | return ret; | |
7000 | } | |
7001 | ||
7002 | static void perf_event_free_filter(struct perf_event *event) | |
7003 | { | |
7004 | ftrace_profile_free_filter(event); | |
7005 | } | |
7006 | ||
2541517c AS |
7007 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7008 | { | |
7009 | struct bpf_prog *prog; | |
7010 | ||
7011 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7012 | return -EINVAL; | |
7013 | ||
7014 | if (event->tp_event->prog) | |
7015 | return -EEXIST; | |
7016 | ||
04a22fae WN |
7017 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7018 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7019 | return -EINVAL; |
7020 | ||
7021 | prog = bpf_prog_get(prog_fd); | |
7022 | if (IS_ERR(prog)) | |
7023 | return PTR_ERR(prog); | |
7024 | ||
6c373ca8 | 7025 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7026 | /* valid fd, but invalid bpf program type */ |
7027 | bpf_prog_put(prog); | |
7028 | return -EINVAL; | |
7029 | } | |
7030 | ||
7031 | event->tp_event->prog = prog; | |
7032 | ||
7033 | return 0; | |
7034 | } | |
7035 | ||
7036 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7037 | { | |
7038 | struct bpf_prog *prog; | |
7039 | ||
7040 | if (!event->tp_event) | |
7041 | return; | |
7042 | ||
7043 | prog = event->tp_event->prog; | |
7044 | if (prog) { | |
7045 | event->tp_event->prog = NULL; | |
7046 | bpf_prog_put(prog); | |
7047 | } | |
7048 | } | |
7049 | ||
e077df4f | 7050 | #else |
6fb2915d | 7051 | |
b0a873eb | 7052 | static inline void perf_tp_register(void) |
e077df4f | 7053 | { |
e077df4f | 7054 | } |
6fb2915d LZ |
7055 | |
7056 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7057 | { | |
7058 | return -ENOENT; | |
7059 | } | |
7060 | ||
7061 | static void perf_event_free_filter(struct perf_event *event) | |
7062 | { | |
7063 | } | |
7064 | ||
2541517c AS |
7065 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7066 | { | |
7067 | return -ENOENT; | |
7068 | } | |
7069 | ||
7070 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7071 | { | |
7072 | } | |
07b139c8 | 7073 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7074 | |
24f1e32c | 7075 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7076 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7077 | { |
f5ffe02e FW |
7078 | struct perf_sample_data sample; |
7079 | struct pt_regs *regs = data; | |
7080 | ||
fd0d000b | 7081 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7082 | |
a4eaf7f1 | 7083 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7084 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7085 | } |
7086 | #endif | |
7087 | ||
b0a873eb PZ |
7088 | /* |
7089 | * hrtimer based swevent callback | |
7090 | */ | |
f29ac756 | 7091 | |
b0a873eb | 7092 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7093 | { |
b0a873eb PZ |
7094 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7095 | struct perf_sample_data data; | |
7096 | struct pt_regs *regs; | |
7097 | struct perf_event *event; | |
7098 | u64 period; | |
f29ac756 | 7099 | |
b0a873eb | 7100 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7101 | |
7102 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7103 | return HRTIMER_NORESTART; | |
7104 | ||
b0a873eb | 7105 | event->pmu->read(event); |
f344011c | 7106 | |
fd0d000b | 7107 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7108 | regs = get_irq_regs(); |
7109 | ||
7110 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7111 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7112 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7113 | ret = HRTIMER_NORESTART; |
7114 | } | |
24f1e32c | 7115 | |
b0a873eb PZ |
7116 | period = max_t(u64, 10000, event->hw.sample_period); |
7117 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7118 | |
b0a873eb | 7119 | return ret; |
f29ac756 PZ |
7120 | } |
7121 | ||
b0a873eb | 7122 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7123 | { |
b0a873eb | 7124 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7125 | s64 period; |
7126 | ||
7127 | if (!is_sampling_event(event)) | |
7128 | return; | |
f5ffe02e | 7129 | |
5d508e82 FBH |
7130 | period = local64_read(&hwc->period_left); |
7131 | if (period) { | |
7132 | if (period < 0) | |
7133 | period = 10000; | |
fa407f35 | 7134 | |
5d508e82 FBH |
7135 | local64_set(&hwc->period_left, 0); |
7136 | } else { | |
7137 | period = max_t(u64, 10000, hwc->sample_period); | |
7138 | } | |
3497d206 TG |
7139 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7140 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7141 | } |
b0a873eb PZ |
7142 | |
7143 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7144 | { |
b0a873eb PZ |
7145 | struct hw_perf_event *hwc = &event->hw; |
7146 | ||
6c7e550f | 7147 | if (is_sampling_event(event)) { |
b0a873eb | 7148 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7149 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7150 | |
7151 | hrtimer_cancel(&hwc->hrtimer); | |
7152 | } | |
24f1e32c FW |
7153 | } |
7154 | ||
ba3dd36c PZ |
7155 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7156 | { | |
7157 | struct hw_perf_event *hwc = &event->hw; | |
7158 | ||
7159 | if (!is_sampling_event(event)) | |
7160 | return; | |
7161 | ||
7162 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7163 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7164 | ||
7165 | /* | |
7166 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7167 | * mapping and avoid the whole period adjust feedback stuff. | |
7168 | */ | |
7169 | if (event->attr.freq) { | |
7170 | long freq = event->attr.sample_freq; | |
7171 | ||
7172 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7173 | hwc->sample_period = event->attr.sample_period; | |
7174 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7175 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7176 | event->attr.freq = 0; |
7177 | } | |
7178 | } | |
7179 | ||
b0a873eb PZ |
7180 | /* |
7181 | * Software event: cpu wall time clock | |
7182 | */ | |
7183 | ||
7184 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7185 | { |
b0a873eb PZ |
7186 | s64 prev; |
7187 | u64 now; | |
7188 | ||
a4eaf7f1 | 7189 | now = local_clock(); |
b0a873eb PZ |
7190 | prev = local64_xchg(&event->hw.prev_count, now); |
7191 | local64_add(now - prev, &event->count); | |
24f1e32c | 7192 | } |
24f1e32c | 7193 | |
a4eaf7f1 | 7194 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7195 | { |
a4eaf7f1 | 7196 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7197 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7198 | } |
7199 | ||
a4eaf7f1 | 7200 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7201 | { |
b0a873eb PZ |
7202 | perf_swevent_cancel_hrtimer(event); |
7203 | cpu_clock_event_update(event); | |
7204 | } | |
f29ac756 | 7205 | |
a4eaf7f1 PZ |
7206 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7207 | { | |
7208 | if (flags & PERF_EF_START) | |
7209 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7210 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7211 | |
7212 | return 0; | |
7213 | } | |
7214 | ||
7215 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7216 | { | |
7217 | cpu_clock_event_stop(event, flags); | |
7218 | } | |
7219 | ||
b0a873eb PZ |
7220 | static void cpu_clock_event_read(struct perf_event *event) |
7221 | { | |
7222 | cpu_clock_event_update(event); | |
7223 | } | |
f344011c | 7224 | |
b0a873eb PZ |
7225 | static int cpu_clock_event_init(struct perf_event *event) |
7226 | { | |
7227 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7228 | return -ENOENT; | |
7229 | ||
7230 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7231 | return -ENOENT; | |
7232 | ||
2481c5fa SE |
7233 | /* |
7234 | * no branch sampling for software events | |
7235 | */ | |
7236 | if (has_branch_stack(event)) | |
7237 | return -EOPNOTSUPP; | |
7238 | ||
ba3dd36c PZ |
7239 | perf_swevent_init_hrtimer(event); |
7240 | ||
b0a873eb | 7241 | return 0; |
f29ac756 PZ |
7242 | } |
7243 | ||
b0a873eb | 7244 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7245 | .task_ctx_nr = perf_sw_context, |
7246 | ||
34f43927 PZ |
7247 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7248 | ||
b0a873eb | 7249 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7250 | .add = cpu_clock_event_add, |
7251 | .del = cpu_clock_event_del, | |
7252 | .start = cpu_clock_event_start, | |
7253 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7254 | .read = cpu_clock_event_read, |
7255 | }; | |
7256 | ||
7257 | /* | |
7258 | * Software event: task time clock | |
7259 | */ | |
7260 | ||
7261 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7262 | { |
b0a873eb PZ |
7263 | u64 prev; |
7264 | s64 delta; | |
5c92d124 | 7265 | |
b0a873eb PZ |
7266 | prev = local64_xchg(&event->hw.prev_count, now); |
7267 | delta = now - prev; | |
7268 | local64_add(delta, &event->count); | |
7269 | } | |
5c92d124 | 7270 | |
a4eaf7f1 | 7271 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7272 | { |
a4eaf7f1 | 7273 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7274 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7275 | } |
7276 | ||
a4eaf7f1 | 7277 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7278 | { |
7279 | perf_swevent_cancel_hrtimer(event); | |
7280 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7281 | } |
7282 | ||
7283 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7284 | { | |
7285 | if (flags & PERF_EF_START) | |
7286 | task_clock_event_start(event, flags); | |
6a694a60 | 7287 | perf_event_update_userpage(event); |
b0a873eb | 7288 | |
a4eaf7f1 PZ |
7289 | return 0; |
7290 | } | |
7291 | ||
7292 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7293 | { | |
7294 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7295 | } |
7296 | ||
7297 | static void task_clock_event_read(struct perf_event *event) | |
7298 | { | |
768a06e2 PZ |
7299 | u64 now = perf_clock(); |
7300 | u64 delta = now - event->ctx->timestamp; | |
7301 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7302 | |
7303 | task_clock_event_update(event, time); | |
7304 | } | |
7305 | ||
7306 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7307 | { |
b0a873eb PZ |
7308 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7309 | return -ENOENT; | |
7310 | ||
7311 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7312 | return -ENOENT; | |
7313 | ||
2481c5fa SE |
7314 | /* |
7315 | * no branch sampling for software events | |
7316 | */ | |
7317 | if (has_branch_stack(event)) | |
7318 | return -EOPNOTSUPP; | |
7319 | ||
ba3dd36c PZ |
7320 | perf_swevent_init_hrtimer(event); |
7321 | ||
b0a873eb | 7322 | return 0; |
6fb2915d LZ |
7323 | } |
7324 | ||
b0a873eb | 7325 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7326 | .task_ctx_nr = perf_sw_context, |
7327 | ||
34f43927 PZ |
7328 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7329 | ||
b0a873eb | 7330 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7331 | .add = task_clock_event_add, |
7332 | .del = task_clock_event_del, | |
7333 | .start = task_clock_event_start, | |
7334 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7335 | .read = task_clock_event_read, |
7336 | }; | |
6fb2915d | 7337 | |
ad5133b7 | 7338 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7339 | { |
e077df4f | 7340 | } |
6fb2915d | 7341 | |
fbbe0701 SB |
7342 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7343 | { | |
7344 | } | |
7345 | ||
ad5133b7 | 7346 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7347 | { |
ad5133b7 | 7348 | return 0; |
6fb2915d LZ |
7349 | } |
7350 | ||
18ab2cd3 | 7351 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7352 | |
7353 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7354 | { |
fbbe0701 SB |
7355 | __this_cpu_write(nop_txn_flags, flags); |
7356 | ||
7357 | if (flags & ~PERF_PMU_TXN_ADD) | |
7358 | return; | |
7359 | ||
ad5133b7 | 7360 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7361 | } |
7362 | ||
ad5133b7 PZ |
7363 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7364 | { | |
fbbe0701 SB |
7365 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7366 | ||
7367 | __this_cpu_write(nop_txn_flags, 0); | |
7368 | ||
7369 | if (flags & ~PERF_PMU_TXN_ADD) | |
7370 | return 0; | |
7371 | ||
ad5133b7 PZ |
7372 | perf_pmu_enable(pmu); |
7373 | return 0; | |
7374 | } | |
e077df4f | 7375 | |
ad5133b7 | 7376 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7377 | { |
fbbe0701 SB |
7378 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7379 | ||
7380 | __this_cpu_write(nop_txn_flags, 0); | |
7381 | ||
7382 | if (flags & ~PERF_PMU_TXN_ADD) | |
7383 | return; | |
7384 | ||
ad5133b7 | 7385 | perf_pmu_enable(pmu); |
24f1e32c FW |
7386 | } |
7387 | ||
35edc2a5 PZ |
7388 | static int perf_event_idx_default(struct perf_event *event) |
7389 | { | |
c719f560 | 7390 | return 0; |
35edc2a5 PZ |
7391 | } |
7392 | ||
8dc85d54 PZ |
7393 | /* |
7394 | * Ensures all contexts with the same task_ctx_nr have the same | |
7395 | * pmu_cpu_context too. | |
7396 | */ | |
9e317041 | 7397 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7398 | { |
8dc85d54 | 7399 | struct pmu *pmu; |
b326e956 | 7400 | |
8dc85d54 PZ |
7401 | if (ctxn < 0) |
7402 | return NULL; | |
24f1e32c | 7403 | |
8dc85d54 PZ |
7404 | list_for_each_entry(pmu, &pmus, entry) { |
7405 | if (pmu->task_ctx_nr == ctxn) | |
7406 | return pmu->pmu_cpu_context; | |
7407 | } | |
24f1e32c | 7408 | |
8dc85d54 | 7409 | return NULL; |
24f1e32c FW |
7410 | } |
7411 | ||
51676957 | 7412 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7413 | { |
51676957 PZ |
7414 | int cpu; |
7415 | ||
7416 | for_each_possible_cpu(cpu) { | |
7417 | struct perf_cpu_context *cpuctx; | |
7418 | ||
7419 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7420 | ||
3f1f3320 PZ |
7421 | if (cpuctx->unique_pmu == old_pmu) |
7422 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7423 | } |
7424 | } | |
7425 | ||
7426 | static void free_pmu_context(struct pmu *pmu) | |
7427 | { | |
7428 | struct pmu *i; | |
f5ffe02e | 7429 | |
8dc85d54 | 7430 | mutex_lock(&pmus_lock); |
0475f9ea | 7431 | /* |
8dc85d54 | 7432 | * Like a real lame refcount. |
0475f9ea | 7433 | */ |
51676957 PZ |
7434 | list_for_each_entry(i, &pmus, entry) { |
7435 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7436 | update_pmu_context(i, pmu); | |
8dc85d54 | 7437 | goto out; |
51676957 | 7438 | } |
8dc85d54 | 7439 | } |
d6d020e9 | 7440 | |
51676957 | 7441 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7442 | out: |
7443 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7444 | } |
2e80a82a | 7445 | static struct idr pmu_idr; |
d6d020e9 | 7446 | |
abe43400 PZ |
7447 | static ssize_t |
7448 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7449 | { | |
7450 | struct pmu *pmu = dev_get_drvdata(dev); | |
7451 | ||
7452 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7453 | } | |
90826ca7 | 7454 | static DEVICE_ATTR_RO(type); |
abe43400 | 7455 | |
62b85639 SE |
7456 | static ssize_t |
7457 | perf_event_mux_interval_ms_show(struct device *dev, | |
7458 | struct device_attribute *attr, | |
7459 | char *page) | |
7460 | { | |
7461 | struct pmu *pmu = dev_get_drvdata(dev); | |
7462 | ||
7463 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7464 | } | |
7465 | ||
272325c4 PZ |
7466 | static DEFINE_MUTEX(mux_interval_mutex); |
7467 | ||
62b85639 SE |
7468 | static ssize_t |
7469 | perf_event_mux_interval_ms_store(struct device *dev, | |
7470 | struct device_attribute *attr, | |
7471 | const char *buf, size_t count) | |
7472 | { | |
7473 | struct pmu *pmu = dev_get_drvdata(dev); | |
7474 | int timer, cpu, ret; | |
7475 | ||
7476 | ret = kstrtoint(buf, 0, &timer); | |
7477 | if (ret) | |
7478 | return ret; | |
7479 | ||
7480 | if (timer < 1) | |
7481 | return -EINVAL; | |
7482 | ||
7483 | /* same value, noting to do */ | |
7484 | if (timer == pmu->hrtimer_interval_ms) | |
7485 | return count; | |
7486 | ||
272325c4 | 7487 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7488 | pmu->hrtimer_interval_ms = timer; |
7489 | ||
7490 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7491 | get_online_cpus(); |
7492 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7493 | struct perf_cpu_context *cpuctx; |
7494 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7495 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7496 | ||
272325c4 PZ |
7497 | cpu_function_call(cpu, |
7498 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7499 | } |
272325c4 PZ |
7500 | put_online_cpus(); |
7501 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7502 | |
7503 | return count; | |
7504 | } | |
90826ca7 | 7505 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7506 | |
90826ca7 GKH |
7507 | static struct attribute *pmu_dev_attrs[] = { |
7508 | &dev_attr_type.attr, | |
7509 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7510 | NULL, | |
abe43400 | 7511 | }; |
90826ca7 | 7512 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7513 | |
7514 | static int pmu_bus_running; | |
7515 | static struct bus_type pmu_bus = { | |
7516 | .name = "event_source", | |
90826ca7 | 7517 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7518 | }; |
7519 | ||
7520 | static void pmu_dev_release(struct device *dev) | |
7521 | { | |
7522 | kfree(dev); | |
7523 | } | |
7524 | ||
7525 | static int pmu_dev_alloc(struct pmu *pmu) | |
7526 | { | |
7527 | int ret = -ENOMEM; | |
7528 | ||
7529 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7530 | if (!pmu->dev) | |
7531 | goto out; | |
7532 | ||
0c9d42ed | 7533 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7534 | device_initialize(pmu->dev); |
7535 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7536 | if (ret) | |
7537 | goto free_dev; | |
7538 | ||
7539 | dev_set_drvdata(pmu->dev, pmu); | |
7540 | pmu->dev->bus = &pmu_bus; | |
7541 | pmu->dev->release = pmu_dev_release; | |
7542 | ret = device_add(pmu->dev); | |
7543 | if (ret) | |
7544 | goto free_dev; | |
7545 | ||
7546 | out: | |
7547 | return ret; | |
7548 | ||
7549 | free_dev: | |
7550 | put_device(pmu->dev); | |
7551 | goto out; | |
7552 | } | |
7553 | ||
547e9fd7 | 7554 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7555 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7556 | |
03d8e80b | 7557 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7558 | { |
108b02cf | 7559 | int cpu, ret; |
24f1e32c | 7560 | |
b0a873eb | 7561 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7562 | ret = -ENOMEM; |
7563 | pmu->pmu_disable_count = alloc_percpu(int); | |
7564 | if (!pmu->pmu_disable_count) | |
7565 | goto unlock; | |
f29ac756 | 7566 | |
2e80a82a PZ |
7567 | pmu->type = -1; |
7568 | if (!name) | |
7569 | goto skip_type; | |
7570 | pmu->name = name; | |
7571 | ||
7572 | if (type < 0) { | |
0e9c3be2 TH |
7573 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7574 | if (type < 0) { | |
7575 | ret = type; | |
2e80a82a PZ |
7576 | goto free_pdc; |
7577 | } | |
7578 | } | |
7579 | pmu->type = type; | |
7580 | ||
abe43400 PZ |
7581 | if (pmu_bus_running) { |
7582 | ret = pmu_dev_alloc(pmu); | |
7583 | if (ret) | |
7584 | goto free_idr; | |
7585 | } | |
7586 | ||
2e80a82a | 7587 | skip_type: |
8dc85d54 PZ |
7588 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7589 | if (pmu->pmu_cpu_context) | |
7590 | goto got_cpu_context; | |
f29ac756 | 7591 | |
c4814202 | 7592 | ret = -ENOMEM; |
108b02cf PZ |
7593 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7594 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7595 | goto free_dev; |
f344011c | 7596 | |
108b02cf PZ |
7597 | for_each_possible_cpu(cpu) { |
7598 | struct perf_cpu_context *cpuctx; | |
7599 | ||
7600 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7601 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7602 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7603 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7604 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7605 | |
272325c4 | 7606 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7607 | |
3f1f3320 | 7608 | cpuctx->unique_pmu = pmu; |
108b02cf | 7609 | } |
76e1d904 | 7610 | |
8dc85d54 | 7611 | got_cpu_context: |
ad5133b7 PZ |
7612 | if (!pmu->start_txn) { |
7613 | if (pmu->pmu_enable) { | |
7614 | /* | |
7615 | * If we have pmu_enable/pmu_disable calls, install | |
7616 | * transaction stubs that use that to try and batch | |
7617 | * hardware accesses. | |
7618 | */ | |
7619 | pmu->start_txn = perf_pmu_start_txn; | |
7620 | pmu->commit_txn = perf_pmu_commit_txn; | |
7621 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7622 | } else { | |
fbbe0701 | 7623 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7624 | pmu->commit_txn = perf_pmu_nop_int; |
7625 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7626 | } |
5c92d124 | 7627 | } |
15dbf27c | 7628 | |
ad5133b7 PZ |
7629 | if (!pmu->pmu_enable) { |
7630 | pmu->pmu_enable = perf_pmu_nop_void; | |
7631 | pmu->pmu_disable = perf_pmu_nop_void; | |
7632 | } | |
7633 | ||
35edc2a5 PZ |
7634 | if (!pmu->event_idx) |
7635 | pmu->event_idx = perf_event_idx_default; | |
7636 | ||
b0a873eb | 7637 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7638 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7639 | ret = 0; |
7640 | unlock: | |
b0a873eb PZ |
7641 | mutex_unlock(&pmus_lock); |
7642 | ||
33696fc0 | 7643 | return ret; |
108b02cf | 7644 | |
abe43400 PZ |
7645 | free_dev: |
7646 | device_del(pmu->dev); | |
7647 | put_device(pmu->dev); | |
7648 | ||
2e80a82a PZ |
7649 | free_idr: |
7650 | if (pmu->type >= PERF_TYPE_MAX) | |
7651 | idr_remove(&pmu_idr, pmu->type); | |
7652 | ||
108b02cf PZ |
7653 | free_pdc: |
7654 | free_percpu(pmu->pmu_disable_count); | |
7655 | goto unlock; | |
f29ac756 | 7656 | } |
c464c76e | 7657 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7658 | |
b0a873eb | 7659 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7660 | { |
b0a873eb PZ |
7661 | mutex_lock(&pmus_lock); |
7662 | list_del_rcu(&pmu->entry); | |
7663 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7664 | |
0475f9ea | 7665 | /* |
cde8e884 PZ |
7666 | * We dereference the pmu list under both SRCU and regular RCU, so |
7667 | * synchronize against both of those. | |
0475f9ea | 7668 | */ |
b0a873eb | 7669 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7670 | synchronize_rcu(); |
d6d020e9 | 7671 | |
33696fc0 | 7672 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7673 | if (pmu->type >= PERF_TYPE_MAX) |
7674 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7675 | device_del(pmu->dev); |
7676 | put_device(pmu->dev); | |
51676957 | 7677 | free_pmu_context(pmu); |
b0a873eb | 7678 | } |
c464c76e | 7679 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7680 | |
cc34b98b MR |
7681 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7682 | { | |
ccd41c86 | 7683 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7684 | int ret; |
7685 | ||
7686 | if (!try_module_get(pmu->module)) | |
7687 | return -ENODEV; | |
ccd41c86 PZ |
7688 | |
7689 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7690 | /* |
7691 | * This ctx->mutex can nest when we're called through | |
7692 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7693 | */ | |
7694 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7695 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7696 | BUG_ON(!ctx); |
7697 | } | |
7698 | ||
cc34b98b MR |
7699 | event->pmu = pmu; |
7700 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7701 | |
7702 | if (ctx) | |
7703 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7704 | ||
cc34b98b MR |
7705 | if (ret) |
7706 | module_put(pmu->module); | |
7707 | ||
7708 | return ret; | |
7709 | } | |
7710 | ||
18ab2cd3 | 7711 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7712 | { |
7713 | struct pmu *pmu = NULL; | |
7714 | int idx; | |
940c5b29 | 7715 | int ret; |
b0a873eb PZ |
7716 | |
7717 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7718 | |
7719 | rcu_read_lock(); | |
7720 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7721 | rcu_read_unlock(); | |
940c5b29 | 7722 | if (pmu) { |
cc34b98b | 7723 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7724 | if (ret) |
7725 | pmu = ERR_PTR(ret); | |
2e80a82a | 7726 | goto unlock; |
940c5b29 | 7727 | } |
2e80a82a | 7728 | |
b0a873eb | 7729 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7730 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7731 | if (!ret) |
e5f4d339 | 7732 | goto unlock; |
76e1d904 | 7733 | |
b0a873eb PZ |
7734 | if (ret != -ENOENT) { |
7735 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7736 | goto unlock; |
f344011c | 7737 | } |
5c92d124 | 7738 | } |
e5f4d339 PZ |
7739 | pmu = ERR_PTR(-ENOENT); |
7740 | unlock: | |
b0a873eb | 7741 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7742 | |
4aeb0b42 | 7743 | return pmu; |
5c92d124 IM |
7744 | } |
7745 | ||
4beb31f3 FW |
7746 | static void account_event_cpu(struct perf_event *event, int cpu) |
7747 | { | |
7748 | if (event->parent) | |
7749 | return; | |
7750 | ||
4beb31f3 FW |
7751 | if (is_cgroup_event(event)) |
7752 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7753 | } | |
7754 | ||
766d6c07 FW |
7755 | static void account_event(struct perf_event *event) |
7756 | { | |
25432ae9 PZ |
7757 | bool inc = false; |
7758 | ||
4beb31f3 FW |
7759 | if (event->parent) |
7760 | return; | |
7761 | ||
766d6c07 | 7762 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7763 | inc = true; |
766d6c07 FW |
7764 | if (event->attr.mmap || event->attr.mmap_data) |
7765 | atomic_inc(&nr_mmap_events); | |
7766 | if (event->attr.comm) | |
7767 | atomic_inc(&nr_comm_events); | |
7768 | if (event->attr.task) | |
7769 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7770 | if (event->attr.freq) { |
7771 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7772 | tick_nohz_full_kick_all(); | |
7773 | } | |
45ac1403 AH |
7774 | if (event->attr.context_switch) { |
7775 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7776 | inc = true; |
45ac1403 | 7777 | } |
4beb31f3 | 7778 | if (has_branch_stack(event)) |
25432ae9 | 7779 | inc = true; |
4beb31f3 | 7780 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7781 | inc = true; |
7782 | ||
7783 | if (inc) | |
766d6c07 | 7784 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7785 | |
7786 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7787 | } |
7788 | ||
0793a61d | 7789 | /* |
cdd6c482 | 7790 | * Allocate and initialize a event structure |
0793a61d | 7791 | */ |
cdd6c482 | 7792 | static struct perf_event * |
c3f00c70 | 7793 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7794 | struct task_struct *task, |
7795 | struct perf_event *group_leader, | |
7796 | struct perf_event *parent_event, | |
4dc0da86 | 7797 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7798 | void *context, int cgroup_fd) |
0793a61d | 7799 | { |
51b0fe39 | 7800 | struct pmu *pmu; |
cdd6c482 IM |
7801 | struct perf_event *event; |
7802 | struct hw_perf_event *hwc; | |
90983b16 | 7803 | long err = -EINVAL; |
0793a61d | 7804 | |
66832eb4 ON |
7805 | if ((unsigned)cpu >= nr_cpu_ids) { |
7806 | if (!task || cpu != -1) | |
7807 | return ERR_PTR(-EINVAL); | |
7808 | } | |
7809 | ||
c3f00c70 | 7810 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7811 | if (!event) |
d5d2bc0d | 7812 | return ERR_PTR(-ENOMEM); |
0793a61d | 7813 | |
04289bb9 | 7814 | /* |
cdd6c482 | 7815 | * Single events are their own group leaders, with an |
04289bb9 IM |
7816 | * empty sibling list: |
7817 | */ | |
7818 | if (!group_leader) | |
cdd6c482 | 7819 | group_leader = event; |
04289bb9 | 7820 | |
cdd6c482 IM |
7821 | mutex_init(&event->child_mutex); |
7822 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7823 | |
cdd6c482 IM |
7824 | INIT_LIST_HEAD(&event->group_entry); |
7825 | INIT_LIST_HEAD(&event->event_entry); | |
7826 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7827 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7828 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7829 | INIT_HLIST_NODE(&event->hlist_entry); |
7830 | ||
10c6db11 | 7831 | |
cdd6c482 | 7832 | init_waitqueue_head(&event->waitq); |
e360adbe | 7833 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7834 | |
cdd6c482 | 7835 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7836 | |
a6fa941d | 7837 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7838 | event->cpu = cpu; |
7839 | event->attr = *attr; | |
7840 | event->group_leader = group_leader; | |
7841 | event->pmu = NULL; | |
cdd6c482 | 7842 | event->oncpu = -1; |
a96bbc16 | 7843 | |
cdd6c482 | 7844 | event->parent = parent_event; |
b84fbc9f | 7845 | |
17cf22c3 | 7846 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7847 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7848 | |
cdd6c482 | 7849 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7850 | |
d580ff86 PZ |
7851 | if (task) { |
7852 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7853 | /* |
50f16a8b PZ |
7854 | * XXX pmu::event_init needs to know what task to account to |
7855 | * and we cannot use the ctx information because we need the | |
7856 | * pmu before we get a ctx. | |
d580ff86 | 7857 | */ |
50f16a8b | 7858 | event->hw.target = task; |
d580ff86 PZ |
7859 | } |
7860 | ||
34f43927 PZ |
7861 | event->clock = &local_clock; |
7862 | if (parent_event) | |
7863 | event->clock = parent_event->clock; | |
7864 | ||
4dc0da86 | 7865 | if (!overflow_handler && parent_event) { |
b326e956 | 7866 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7867 | context = parent_event->overflow_handler_context; |
7868 | } | |
66832eb4 | 7869 | |
b326e956 | 7870 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7871 | event->overflow_handler_context = context; |
97eaf530 | 7872 | |
0231bb53 | 7873 | perf_event__state_init(event); |
a86ed508 | 7874 | |
4aeb0b42 | 7875 | pmu = NULL; |
b8e83514 | 7876 | |
cdd6c482 | 7877 | hwc = &event->hw; |
bd2b5b12 | 7878 | hwc->sample_period = attr->sample_period; |
0d48696f | 7879 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7880 | hwc->sample_period = 1; |
eced1dfc | 7881 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7882 | |
e7850595 | 7883 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7884 | |
2023b359 | 7885 | /* |
cdd6c482 | 7886 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7887 | */ |
3dab77fb | 7888 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7889 | goto err_ns; |
a46a2300 YZ |
7890 | |
7891 | if (!has_branch_stack(event)) | |
7892 | event->attr.branch_sample_type = 0; | |
2023b359 | 7893 | |
79dff51e MF |
7894 | if (cgroup_fd != -1) { |
7895 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7896 | if (err) | |
7897 | goto err_ns; | |
7898 | } | |
7899 | ||
b0a873eb | 7900 | pmu = perf_init_event(event); |
4aeb0b42 | 7901 | if (!pmu) |
90983b16 FW |
7902 | goto err_ns; |
7903 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7904 | err = PTR_ERR(pmu); |
90983b16 | 7905 | goto err_ns; |
621a01ea | 7906 | } |
d5d2bc0d | 7907 | |
bed5b25a AS |
7908 | err = exclusive_event_init(event); |
7909 | if (err) | |
7910 | goto err_pmu; | |
7911 | ||
cdd6c482 | 7912 | if (!event->parent) { |
927c7a9e FW |
7913 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7914 | err = get_callchain_buffers(); | |
90983b16 | 7915 | if (err) |
bed5b25a | 7916 | goto err_per_task; |
d010b332 | 7917 | } |
f344011c | 7918 | } |
9ee318a7 | 7919 | |
cdd6c482 | 7920 | return event; |
90983b16 | 7921 | |
bed5b25a AS |
7922 | err_per_task: |
7923 | exclusive_event_destroy(event); | |
7924 | ||
90983b16 FW |
7925 | err_pmu: |
7926 | if (event->destroy) | |
7927 | event->destroy(event); | |
c464c76e | 7928 | module_put(pmu->module); |
90983b16 | 7929 | err_ns: |
79dff51e MF |
7930 | if (is_cgroup_event(event)) |
7931 | perf_detach_cgroup(event); | |
90983b16 FW |
7932 | if (event->ns) |
7933 | put_pid_ns(event->ns); | |
7934 | kfree(event); | |
7935 | ||
7936 | return ERR_PTR(err); | |
0793a61d TG |
7937 | } |
7938 | ||
cdd6c482 IM |
7939 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7940 | struct perf_event_attr *attr) | |
974802ea | 7941 | { |
974802ea | 7942 | u32 size; |
cdf8073d | 7943 | int ret; |
974802ea PZ |
7944 | |
7945 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7946 | return -EFAULT; | |
7947 | ||
7948 | /* | |
7949 | * zero the full structure, so that a short copy will be nice. | |
7950 | */ | |
7951 | memset(attr, 0, sizeof(*attr)); | |
7952 | ||
7953 | ret = get_user(size, &uattr->size); | |
7954 | if (ret) | |
7955 | return ret; | |
7956 | ||
7957 | if (size > PAGE_SIZE) /* silly large */ | |
7958 | goto err_size; | |
7959 | ||
7960 | if (!size) /* abi compat */ | |
7961 | size = PERF_ATTR_SIZE_VER0; | |
7962 | ||
7963 | if (size < PERF_ATTR_SIZE_VER0) | |
7964 | goto err_size; | |
7965 | ||
7966 | /* | |
7967 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7968 | * ensure all the unknown bits are 0 - i.e. new |
7969 | * user-space does not rely on any kernel feature | |
7970 | * extensions we dont know about yet. | |
974802ea PZ |
7971 | */ |
7972 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7973 | unsigned char __user *addr; |
7974 | unsigned char __user *end; | |
7975 | unsigned char val; | |
974802ea | 7976 | |
cdf8073d IS |
7977 | addr = (void __user *)uattr + sizeof(*attr); |
7978 | end = (void __user *)uattr + size; | |
974802ea | 7979 | |
cdf8073d | 7980 | for (; addr < end; addr++) { |
974802ea PZ |
7981 | ret = get_user(val, addr); |
7982 | if (ret) | |
7983 | return ret; | |
7984 | if (val) | |
7985 | goto err_size; | |
7986 | } | |
b3e62e35 | 7987 | size = sizeof(*attr); |
974802ea PZ |
7988 | } |
7989 | ||
7990 | ret = copy_from_user(attr, uattr, size); | |
7991 | if (ret) | |
7992 | return -EFAULT; | |
7993 | ||
cd757645 | 7994 | if (attr->__reserved_1) |
974802ea PZ |
7995 | return -EINVAL; |
7996 | ||
7997 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7998 | return -EINVAL; | |
7999 | ||
8000 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8001 | return -EINVAL; | |
8002 | ||
bce38cd5 SE |
8003 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8004 | u64 mask = attr->branch_sample_type; | |
8005 | ||
8006 | /* only using defined bits */ | |
8007 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8008 | return -EINVAL; | |
8009 | ||
8010 | /* at least one branch bit must be set */ | |
8011 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8012 | return -EINVAL; | |
8013 | ||
bce38cd5 SE |
8014 | /* propagate priv level, when not set for branch */ |
8015 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8016 | ||
8017 | /* exclude_kernel checked on syscall entry */ | |
8018 | if (!attr->exclude_kernel) | |
8019 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8020 | ||
8021 | if (!attr->exclude_user) | |
8022 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8023 | ||
8024 | if (!attr->exclude_hv) | |
8025 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8026 | /* | |
8027 | * adjust user setting (for HW filter setup) | |
8028 | */ | |
8029 | attr->branch_sample_type = mask; | |
8030 | } | |
e712209a SE |
8031 | /* privileged levels capture (kernel, hv): check permissions */ |
8032 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8033 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8034 | return -EACCES; | |
bce38cd5 | 8035 | } |
4018994f | 8036 | |
c5ebcedb | 8037 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8038 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8039 | if (ret) |
8040 | return ret; | |
8041 | } | |
8042 | ||
8043 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8044 | if (!arch_perf_have_user_stack_dump()) | |
8045 | return -ENOSYS; | |
8046 | ||
8047 | /* | |
8048 | * We have __u32 type for the size, but so far | |
8049 | * we can only use __u16 as maximum due to the | |
8050 | * __u16 sample size limit. | |
8051 | */ | |
8052 | if (attr->sample_stack_user >= USHRT_MAX) | |
8053 | ret = -EINVAL; | |
8054 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8055 | ret = -EINVAL; | |
8056 | } | |
4018994f | 8057 | |
60e2364e SE |
8058 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8059 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8060 | out: |
8061 | return ret; | |
8062 | ||
8063 | err_size: | |
8064 | put_user(sizeof(*attr), &uattr->size); | |
8065 | ret = -E2BIG; | |
8066 | goto out; | |
8067 | } | |
8068 | ||
ac9721f3 PZ |
8069 | static int |
8070 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8071 | { |
b69cf536 | 8072 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8073 | int ret = -EINVAL; |
8074 | ||
ac9721f3 | 8075 | if (!output_event) |
a4be7c27 PZ |
8076 | goto set; |
8077 | ||
ac9721f3 PZ |
8078 | /* don't allow circular references */ |
8079 | if (event == output_event) | |
a4be7c27 PZ |
8080 | goto out; |
8081 | ||
0f139300 PZ |
8082 | /* |
8083 | * Don't allow cross-cpu buffers | |
8084 | */ | |
8085 | if (output_event->cpu != event->cpu) | |
8086 | goto out; | |
8087 | ||
8088 | /* | |
76369139 | 8089 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8090 | */ |
8091 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8092 | goto out; | |
8093 | ||
34f43927 PZ |
8094 | /* |
8095 | * Mixing clocks in the same buffer is trouble you don't need. | |
8096 | */ | |
8097 | if (output_event->clock != event->clock) | |
8098 | goto out; | |
8099 | ||
45bfb2e5 PZ |
8100 | /* |
8101 | * If both events generate aux data, they must be on the same PMU | |
8102 | */ | |
8103 | if (has_aux(event) && has_aux(output_event) && | |
8104 | event->pmu != output_event->pmu) | |
8105 | goto out; | |
8106 | ||
a4be7c27 | 8107 | set: |
cdd6c482 | 8108 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8109 | /* Can't redirect output if we've got an active mmap() */ |
8110 | if (atomic_read(&event->mmap_count)) | |
8111 | goto unlock; | |
a4be7c27 | 8112 | |
ac9721f3 | 8113 | if (output_event) { |
76369139 FW |
8114 | /* get the rb we want to redirect to */ |
8115 | rb = ring_buffer_get(output_event); | |
8116 | if (!rb) | |
ac9721f3 | 8117 | goto unlock; |
a4be7c27 PZ |
8118 | } |
8119 | ||
b69cf536 | 8120 | ring_buffer_attach(event, rb); |
9bb5d40c | 8121 | |
a4be7c27 | 8122 | ret = 0; |
ac9721f3 PZ |
8123 | unlock: |
8124 | mutex_unlock(&event->mmap_mutex); | |
8125 | ||
a4be7c27 | 8126 | out: |
a4be7c27 PZ |
8127 | return ret; |
8128 | } | |
8129 | ||
f63a8daa PZ |
8130 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8131 | { | |
8132 | if (b < a) | |
8133 | swap(a, b); | |
8134 | ||
8135 | mutex_lock(a); | |
8136 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8137 | } | |
8138 | ||
34f43927 PZ |
8139 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8140 | { | |
8141 | bool nmi_safe = false; | |
8142 | ||
8143 | switch (clk_id) { | |
8144 | case CLOCK_MONOTONIC: | |
8145 | event->clock = &ktime_get_mono_fast_ns; | |
8146 | nmi_safe = true; | |
8147 | break; | |
8148 | ||
8149 | case CLOCK_MONOTONIC_RAW: | |
8150 | event->clock = &ktime_get_raw_fast_ns; | |
8151 | nmi_safe = true; | |
8152 | break; | |
8153 | ||
8154 | case CLOCK_REALTIME: | |
8155 | event->clock = &ktime_get_real_ns; | |
8156 | break; | |
8157 | ||
8158 | case CLOCK_BOOTTIME: | |
8159 | event->clock = &ktime_get_boot_ns; | |
8160 | break; | |
8161 | ||
8162 | case CLOCK_TAI: | |
8163 | event->clock = &ktime_get_tai_ns; | |
8164 | break; | |
8165 | ||
8166 | default: | |
8167 | return -EINVAL; | |
8168 | } | |
8169 | ||
8170 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8171 | return -EINVAL; | |
8172 | ||
8173 | return 0; | |
8174 | } | |
8175 | ||
0793a61d | 8176 | /** |
cdd6c482 | 8177 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8178 | * |
cdd6c482 | 8179 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8180 | * @pid: target pid |
9f66a381 | 8181 | * @cpu: target cpu |
cdd6c482 | 8182 | * @group_fd: group leader event fd |
0793a61d | 8183 | */ |
cdd6c482 IM |
8184 | SYSCALL_DEFINE5(perf_event_open, |
8185 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8186 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8187 | { |
b04243ef PZ |
8188 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8189 | struct perf_event *event, *sibling; | |
cdd6c482 | 8190 | struct perf_event_attr attr; |
f63a8daa | 8191 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8192 | struct file *event_file = NULL; |
2903ff01 | 8193 | struct fd group = {NULL, 0}; |
38a81da2 | 8194 | struct task_struct *task = NULL; |
89a1e187 | 8195 | struct pmu *pmu; |
ea635c64 | 8196 | int event_fd; |
b04243ef | 8197 | int move_group = 0; |
dc86cabe | 8198 | int err; |
a21b0b35 | 8199 | int f_flags = O_RDWR; |
79dff51e | 8200 | int cgroup_fd = -1; |
0793a61d | 8201 | |
2743a5b0 | 8202 | /* for future expandability... */ |
e5d1367f | 8203 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8204 | return -EINVAL; |
8205 | ||
dc86cabe IM |
8206 | err = perf_copy_attr(attr_uptr, &attr); |
8207 | if (err) | |
8208 | return err; | |
eab656ae | 8209 | |
0764771d PZ |
8210 | if (!attr.exclude_kernel) { |
8211 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8212 | return -EACCES; | |
8213 | } | |
8214 | ||
df58ab24 | 8215 | if (attr.freq) { |
cdd6c482 | 8216 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8217 | return -EINVAL; |
0819b2e3 PZ |
8218 | } else { |
8219 | if (attr.sample_period & (1ULL << 63)) | |
8220 | return -EINVAL; | |
df58ab24 PZ |
8221 | } |
8222 | ||
e5d1367f SE |
8223 | /* |
8224 | * In cgroup mode, the pid argument is used to pass the fd | |
8225 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8226 | * designates the cpu on which to monitor threads from that | |
8227 | * cgroup. | |
8228 | */ | |
8229 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8230 | return -EINVAL; | |
8231 | ||
a21b0b35 YD |
8232 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8233 | f_flags |= O_CLOEXEC; | |
8234 | ||
8235 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8236 | if (event_fd < 0) |
8237 | return event_fd; | |
8238 | ||
ac9721f3 | 8239 | if (group_fd != -1) { |
2903ff01 AV |
8240 | err = perf_fget_light(group_fd, &group); |
8241 | if (err) | |
d14b12d7 | 8242 | goto err_fd; |
2903ff01 | 8243 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8244 | if (flags & PERF_FLAG_FD_OUTPUT) |
8245 | output_event = group_leader; | |
8246 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8247 | group_leader = NULL; | |
8248 | } | |
8249 | ||
e5d1367f | 8250 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8251 | task = find_lively_task_by_vpid(pid); |
8252 | if (IS_ERR(task)) { | |
8253 | err = PTR_ERR(task); | |
8254 | goto err_group_fd; | |
8255 | } | |
8256 | } | |
8257 | ||
1f4ee503 PZ |
8258 | if (task && group_leader && |
8259 | group_leader->attr.inherit != attr.inherit) { | |
8260 | err = -EINVAL; | |
8261 | goto err_task; | |
8262 | } | |
8263 | ||
fbfc623f YZ |
8264 | get_online_cpus(); |
8265 | ||
79dff51e MF |
8266 | if (flags & PERF_FLAG_PID_CGROUP) |
8267 | cgroup_fd = pid; | |
8268 | ||
4dc0da86 | 8269 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8270 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8271 | if (IS_ERR(event)) { |
8272 | err = PTR_ERR(event); | |
1f4ee503 | 8273 | goto err_cpus; |
d14b12d7 SE |
8274 | } |
8275 | ||
53b25335 VW |
8276 | if (is_sampling_event(event)) { |
8277 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8278 | err = -ENOTSUPP; | |
8279 | goto err_alloc; | |
8280 | } | |
8281 | } | |
8282 | ||
766d6c07 FW |
8283 | account_event(event); |
8284 | ||
89a1e187 PZ |
8285 | /* |
8286 | * Special case software events and allow them to be part of | |
8287 | * any hardware group. | |
8288 | */ | |
8289 | pmu = event->pmu; | |
b04243ef | 8290 | |
34f43927 PZ |
8291 | if (attr.use_clockid) { |
8292 | err = perf_event_set_clock(event, attr.clockid); | |
8293 | if (err) | |
8294 | goto err_alloc; | |
8295 | } | |
8296 | ||
b04243ef PZ |
8297 | if (group_leader && |
8298 | (is_software_event(event) != is_software_event(group_leader))) { | |
8299 | if (is_software_event(event)) { | |
8300 | /* | |
8301 | * If event and group_leader are not both a software | |
8302 | * event, and event is, then group leader is not. | |
8303 | * | |
8304 | * Allow the addition of software events to !software | |
8305 | * groups, this is safe because software events never | |
8306 | * fail to schedule. | |
8307 | */ | |
8308 | pmu = group_leader->pmu; | |
8309 | } else if (is_software_event(group_leader) && | |
8310 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8311 | /* | |
8312 | * In case the group is a pure software group, and we | |
8313 | * try to add a hardware event, move the whole group to | |
8314 | * the hardware context. | |
8315 | */ | |
8316 | move_group = 1; | |
8317 | } | |
8318 | } | |
89a1e187 PZ |
8319 | |
8320 | /* | |
8321 | * Get the target context (task or percpu): | |
8322 | */ | |
4af57ef2 | 8323 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8324 | if (IS_ERR(ctx)) { |
8325 | err = PTR_ERR(ctx); | |
c6be5a5c | 8326 | goto err_alloc; |
89a1e187 PZ |
8327 | } |
8328 | ||
bed5b25a AS |
8329 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8330 | err = -EBUSY; | |
8331 | goto err_context; | |
8332 | } | |
8333 | ||
fd1edb3a PZ |
8334 | if (task) { |
8335 | put_task_struct(task); | |
8336 | task = NULL; | |
8337 | } | |
8338 | ||
ccff286d | 8339 | /* |
cdd6c482 | 8340 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8341 | */ |
ac9721f3 | 8342 | if (group_leader) { |
dc86cabe | 8343 | err = -EINVAL; |
04289bb9 | 8344 | |
04289bb9 | 8345 | /* |
ccff286d IM |
8346 | * Do not allow a recursive hierarchy (this new sibling |
8347 | * becoming part of another group-sibling): | |
8348 | */ | |
8349 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8350 | goto err_context; |
34f43927 PZ |
8351 | |
8352 | /* All events in a group should have the same clock */ | |
8353 | if (group_leader->clock != event->clock) | |
8354 | goto err_context; | |
8355 | ||
ccff286d IM |
8356 | /* |
8357 | * Do not allow to attach to a group in a different | |
8358 | * task or CPU context: | |
04289bb9 | 8359 | */ |
b04243ef | 8360 | if (move_group) { |
c3c87e77 PZ |
8361 | /* |
8362 | * Make sure we're both on the same task, or both | |
8363 | * per-cpu events. | |
8364 | */ | |
8365 | if (group_leader->ctx->task != ctx->task) | |
8366 | goto err_context; | |
8367 | ||
8368 | /* | |
8369 | * Make sure we're both events for the same CPU; | |
8370 | * grouping events for different CPUs is broken; since | |
8371 | * you can never concurrently schedule them anyhow. | |
8372 | */ | |
8373 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8374 | goto err_context; |
8375 | } else { | |
8376 | if (group_leader->ctx != ctx) | |
8377 | goto err_context; | |
8378 | } | |
8379 | ||
3b6f9e5c PM |
8380 | /* |
8381 | * Only a group leader can be exclusive or pinned | |
8382 | */ | |
0d48696f | 8383 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8384 | goto err_context; |
ac9721f3 PZ |
8385 | } |
8386 | ||
8387 | if (output_event) { | |
8388 | err = perf_event_set_output(event, output_event); | |
8389 | if (err) | |
c3f00c70 | 8390 | goto err_context; |
ac9721f3 | 8391 | } |
0793a61d | 8392 | |
a21b0b35 YD |
8393 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8394 | f_flags); | |
ea635c64 AV |
8395 | if (IS_ERR(event_file)) { |
8396 | err = PTR_ERR(event_file); | |
c3f00c70 | 8397 | goto err_context; |
ea635c64 | 8398 | } |
9b51f66d | 8399 | |
b04243ef | 8400 | if (move_group) { |
f63a8daa | 8401 | gctx = group_leader->ctx; |
f55fc2a5 | 8402 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
84c4e620 PZ |
8403 | if (gctx->task == TASK_TOMBSTONE) { |
8404 | err = -ESRCH; | |
8405 | goto err_locked; | |
8406 | } | |
f55fc2a5 PZ |
8407 | } else { |
8408 | mutex_lock(&ctx->mutex); | |
8409 | } | |
8410 | ||
84c4e620 PZ |
8411 | if (ctx->task == TASK_TOMBSTONE) { |
8412 | err = -ESRCH; | |
8413 | goto err_locked; | |
8414 | } | |
8415 | ||
a723968c PZ |
8416 | if (!perf_event_validate_size(event)) { |
8417 | err = -E2BIG; | |
8418 | goto err_locked; | |
8419 | } | |
8420 | ||
f55fc2a5 PZ |
8421 | /* |
8422 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8423 | * because we need to serialize with concurrent event creation. | |
8424 | */ | |
8425 | if (!exclusive_event_installable(event, ctx)) { | |
8426 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8427 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8428 | |
f55fc2a5 PZ |
8429 | err = -EBUSY; |
8430 | goto err_locked; | |
8431 | } | |
f63a8daa | 8432 | |
f55fc2a5 PZ |
8433 | WARN_ON_ONCE(ctx->parent_ctx); |
8434 | ||
8435 | if (move_group) { | |
f63a8daa PZ |
8436 | /* |
8437 | * See perf_event_ctx_lock() for comments on the details | |
8438 | * of swizzling perf_event::ctx. | |
8439 | */ | |
45a0e07a | 8440 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8441 | |
b04243ef PZ |
8442 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8443 | group_entry) { | |
45a0e07a | 8444 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8445 | put_ctx(gctx); |
8446 | } | |
b04243ef | 8447 | |
f63a8daa PZ |
8448 | /* |
8449 | * Wait for everybody to stop referencing the events through | |
8450 | * the old lists, before installing it on new lists. | |
8451 | */ | |
0cda4c02 | 8452 | synchronize_rcu(); |
f63a8daa | 8453 | |
8f95b435 PZI |
8454 | /* |
8455 | * Install the group siblings before the group leader. | |
8456 | * | |
8457 | * Because a group leader will try and install the entire group | |
8458 | * (through the sibling list, which is still in-tact), we can | |
8459 | * end up with siblings installed in the wrong context. | |
8460 | * | |
8461 | * By installing siblings first we NO-OP because they're not | |
8462 | * reachable through the group lists. | |
8463 | */ | |
b04243ef PZ |
8464 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8465 | group_entry) { | |
8f95b435 | 8466 | perf_event__state_init(sibling); |
9fc81d87 | 8467 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8468 | get_ctx(ctx); |
8469 | } | |
8f95b435 PZI |
8470 | |
8471 | /* | |
8472 | * Removing from the context ends up with disabled | |
8473 | * event. What we want here is event in the initial | |
8474 | * startup state, ready to be add into new context. | |
8475 | */ | |
8476 | perf_event__state_init(group_leader); | |
8477 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8478 | get_ctx(ctx); | |
b04243ef | 8479 | |
f55fc2a5 PZ |
8480 | /* |
8481 | * Now that all events are installed in @ctx, nothing | |
8482 | * references @gctx anymore, so drop the last reference we have | |
8483 | * on it. | |
8484 | */ | |
8485 | put_ctx(gctx); | |
bed5b25a AS |
8486 | } |
8487 | ||
f73e22ab PZ |
8488 | /* |
8489 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8490 | * that we're serialized against further additions and before | |
8491 | * perf_install_in_context() which is the point the event is active and | |
8492 | * can use these values. | |
8493 | */ | |
8494 | perf_event__header_size(event); | |
8495 | perf_event__id_header_size(event); | |
8496 | ||
78cd2c74 PZ |
8497 | event->owner = current; |
8498 | ||
e2d37cd2 | 8499 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8500 | perf_unpin_context(ctx); |
f63a8daa | 8501 | |
f55fc2a5 | 8502 | if (move_group) |
f63a8daa | 8503 | mutex_unlock(&gctx->mutex); |
d859e29f | 8504 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8505 | |
fbfc623f YZ |
8506 | put_online_cpus(); |
8507 | ||
cdd6c482 IM |
8508 | mutex_lock(¤t->perf_event_mutex); |
8509 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8510 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8511 | |
8a49542c PZ |
8512 | /* |
8513 | * Drop the reference on the group_event after placing the | |
8514 | * new event on the sibling_list. This ensures destruction | |
8515 | * of the group leader will find the pointer to itself in | |
8516 | * perf_group_detach(). | |
8517 | */ | |
2903ff01 | 8518 | fdput(group); |
ea635c64 AV |
8519 | fd_install(event_fd, event_file); |
8520 | return event_fd; | |
0793a61d | 8521 | |
f55fc2a5 PZ |
8522 | err_locked: |
8523 | if (move_group) | |
8524 | mutex_unlock(&gctx->mutex); | |
8525 | mutex_unlock(&ctx->mutex); | |
8526 | /* err_file: */ | |
8527 | fput(event_file); | |
c3f00c70 | 8528 | err_context: |
fe4b04fa | 8529 | perf_unpin_context(ctx); |
ea635c64 | 8530 | put_ctx(ctx); |
c6be5a5c | 8531 | err_alloc: |
13005627 PZ |
8532 | /* |
8533 | * If event_file is set, the fput() above will have called ->release() | |
8534 | * and that will take care of freeing the event. | |
8535 | */ | |
8536 | if (!event_file) | |
8537 | free_event(event); | |
1f4ee503 | 8538 | err_cpus: |
fbfc623f | 8539 | put_online_cpus(); |
1f4ee503 | 8540 | err_task: |
e7d0bc04 PZ |
8541 | if (task) |
8542 | put_task_struct(task); | |
89a1e187 | 8543 | err_group_fd: |
2903ff01 | 8544 | fdput(group); |
ea635c64 AV |
8545 | err_fd: |
8546 | put_unused_fd(event_fd); | |
dc86cabe | 8547 | return err; |
0793a61d TG |
8548 | } |
8549 | ||
fb0459d7 AV |
8550 | /** |
8551 | * perf_event_create_kernel_counter | |
8552 | * | |
8553 | * @attr: attributes of the counter to create | |
8554 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8555 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8556 | */ |
8557 | struct perf_event * | |
8558 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8559 | struct task_struct *task, |
4dc0da86 AK |
8560 | perf_overflow_handler_t overflow_handler, |
8561 | void *context) | |
fb0459d7 | 8562 | { |
fb0459d7 | 8563 | struct perf_event_context *ctx; |
c3f00c70 | 8564 | struct perf_event *event; |
fb0459d7 | 8565 | int err; |
d859e29f | 8566 | |
fb0459d7 AV |
8567 | /* |
8568 | * Get the target context (task or percpu): | |
8569 | */ | |
d859e29f | 8570 | |
4dc0da86 | 8571 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8572 | overflow_handler, context, -1); |
c3f00c70 PZ |
8573 | if (IS_ERR(event)) { |
8574 | err = PTR_ERR(event); | |
8575 | goto err; | |
8576 | } | |
d859e29f | 8577 | |
f8697762 | 8578 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8579 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8580 | |
766d6c07 FW |
8581 | account_event(event); |
8582 | ||
4af57ef2 | 8583 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8584 | if (IS_ERR(ctx)) { |
8585 | err = PTR_ERR(ctx); | |
c3f00c70 | 8586 | goto err_free; |
d859e29f | 8587 | } |
fb0459d7 | 8588 | |
fb0459d7 AV |
8589 | WARN_ON_ONCE(ctx->parent_ctx); |
8590 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
8591 | if (ctx->task == TASK_TOMBSTONE) { |
8592 | err = -ESRCH; | |
8593 | goto err_unlock; | |
8594 | } | |
8595 | ||
bed5b25a | 8596 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 8597 | err = -EBUSY; |
84c4e620 | 8598 | goto err_unlock; |
bed5b25a AS |
8599 | } |
8600 | ||
fb0459d7 | 8601 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8602 | perf_unpin_context(ctx); |
fb0459d7 AV |
8603 | mutex_unlock(&ctx->mutex); |
8604 | ||
fb0459d7 AV |
8605 | return event; |
8606 | ||
84c4e620 PZ |
8607 | err_unlock: |
8608 | mutex_unlock(&ctx->mutex); | |
8609 | perf_unpin_context(ctx); | |
8610 | put_ctx(ctx); | |
c3f00c70 PZ |
8611 | err_free: |
8612 | free_event(event); | |
8613 | err: | |
c6567f64 | 8614 | return ERR_PTR(err); |
9b51f66d | 8615 | } |
fb0459d7 | 8616 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8617 | |
0cda4c02 YZ |
8618 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8619 | { | |
8620 | struct perf_event_context *src_ctx; | |
8621 | struct perf_event_context *dst_ctx; | |
8622 | struct perf_event *event, *tmp; | |
8623 | LIST_HEAD(events); | |
8624 | ||
8625 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8626 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8627 | ||
f63a8daa PZ |
8628 | /* |
8629 | * See perf_event_ctx_lock() for comments on the details | |
8630 | * of swizzling perf_event::ctx. | |
8631 | */ | |
8632 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8633 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8634 | event_entry) { | |
45a0e07a | 8635 | perf_remove_from_context(event, 0); |
9a545de0 | 8636 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8637 | put_ctx(src_ctx); |
9886167d | 8638 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8639 | } |
0cda4c02 | 8640 | |
8f95b435 PZI |
8641 | /* |
8642 | * Wait for the events to quiesce before re-instating them. | |
8643 | */ | |
0cda4c02 YZ |
8644 | synchronize_rcu(); |
8645 | ||
8f95b435 PZI |
8646 | /* |
8647 | * Re-instate events in 2 passes. | |
8648 | * | |
8649 | * Skip over group leaders and only install siblings on this first | |
8650 | * pass, siblings will not get enabled without a leader, however a | |
8651 | * leader will enable its siblings, even if those are still on the old | |
8652 | * context. | |
8653 | */ | |
8654 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8655 | if (event->group_leader == event) | |
8656 | continue; | |
8657 | ||
8658 | list_del(&event->migrate_entry); | |
8659 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8660 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8661 | account_event_cpu(event, dst_cpu); | |
8662 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8663 | get_ctx(dst_ctx); | |
8664 | } | |
8665 | ||
8666 | /* | |
8667 | * Once all the siblings are setup properly, install the group leaders | |
8668 | * to make it go. | |
8669 | */ | |
9886167d PZ |
8670 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8671 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8672 | if (event->state >= PERF_EVENT_STATE_OFF) |
8673 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8674 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8675 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8676 | get_ctx(dst_ctx); | |
8677 | } | |
8678 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8679 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8680 | } |
8681 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8682 | ||
cdd6c482 | 8683 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8684 | struct task_struct *child) |
d859e29f | 8685 | { |
cdd6c482 | 8686 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8687 | u64 child_val; |
d859e29f | 8688 | |
cdd6c482 IM |
8689 | if (child_event->attr.inherit_stat) |
8690 | perf_event_read_event(child_event, child); | |
38b200d6 | 8691 | |
b5e58793 | 8692 | child_val = perf_event_count(child_event); |
d859e29f PM |
8693 | |
8694 | /* | |
8695 | * Add back the child's count to the parent's count: | |
8696 | */ | |
a6e6dea6 | 8697 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8698 | atomic64_add(child_event->total_time_enabled, |
8699 | &parent_event->child_total_time_enabled); | |
8700 | atomic64_add(child_event->total_time_running, | |
8701 | &parent_event->child_total_time_running); | |
d859e29f PM |
8702 | } |
8703 | ||
9b51f66d | 8704 | static void |
8ba289b8 PZ |
8705 | perf_event_exit_event(struct perf_event *child_event, |
8706 | struct perf_event_context *child_ctx, | |
8707 | struct task_struct *child) | |
9b51f66d | 8708 | { |
8ba289b8 PZ |
8709 | struct perf_event *parent_event = child_event->parent; |
8710 | ||
1903d50c PZ |
8711 | /* |
8712 | * Do not destroy the 'original' grouping; because of the context | |
8713 | * switch optimization the original events could've ended up in a | |
8714 | * random child task. | |
8715 | * | |
8716 | * If we were to destroy the original group, all group related | |
8717 | * operations would cease to function properly after this random | |
8718 | * child dies. | |
8719 | * | |
8720 | * Do destroy all inherited groups, we don't care about those | |
8721 | * and being thorough is better. | |
8722 | */ | |
32132a3d PZ |
8723 | raw_spin_lock_irq(&child_ctx->lock); |
8724 | WARN_ON_ONCE(child_ctx->is_active); | |
8725 | ||
8ba289b8 | 8726 | if (parent_event) |
32132a3d PZ |
8727 | perf_group_detach(child_event); |
8728 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 8729 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 8730 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 8731 | |
9b51f66d | 8732 | /* |
8ba289b8 | 8733 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 8734 | */ |
8ba289b8 | 8735 | if (!parent_event) { |
179033b3 | 8736 | perf_event_wakeup(child_event); |
8ba289b8 | 8737 | return; |
4bcf349a | 8738 | } |
8ba289b8 PZ |
8739 | /* |
8740 | * Child events can be cleaned up. | |
8741 | */ | |
8742 | ||
8743 | sync_child_event(child_event, child); | |
8744 | ||
8745 | /* | |
8746 | * Remove this event from the parent's list | |
8747 | */ | |
8748 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8749 | mutex_lock(&parent_event->child_mutex); | |
8750 | list_del_init(&child_event->child_list); | |
8751 | mutex_unlock(&parent_event->child_mutex); | |
8752 | ||
8753 | /* | |
8754 | * Kick perf_poll() for is_event_hup(). | |
8755 | */ | |
8756 | perf_event_wakeup(parent_event); | |
8757 | free_event(child_event); | |
8758 | put_event(parent_event); | |
9b51f66d IM |
8759 | } |
8760 | ||
8dc85d54 | 8761 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8762 | { |
211de6eb | 8763 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 8764 | struct perf_event *child_event, *next; |
63b6da39 PZ |
8765 | |
8766 | WARN_ON_ONCE(child != current); | |
9b51f66d | 8767 | |
6a3351b6 | 8768 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 8769 | if (!child_ctx) |
9b51f66d IM |
8770 | return; |
8771 | ||
ad3a37de | 8772 | /* |
6a3351b6 PZ |
8773 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
8774 | * ctx::mutex over the entire thing. This serializes against almost | |
8775 | * everything that wants to access the ctx. | |
8776 | * | |
8777 | * The exception is sys_perf_event_open() / | |
8778 | * perf_event_create_kernel_count() which does find_get_context() | |
8779 | * without ctx::mutex (it cannot because of the move_group double mutex | |
8780 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 8781 | */ |
6a3351b6 | 8782 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
8783 | |
8784 | /* | |
6a3351b6 PZ |
8785 | * In a single ctx::lock section, de-schedule the events and detach the |
8786 | * context from the task such that we cannot ever get it scheduled back | |
8787 | * in. | |
c93f7669 | 8788 | */ |
6a3351b6 | 8789 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 8790 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 8791 | |
71a851b4 | 8792 | /* |
63b6da39 PZ |
8793 | * Now that the context is inactive, destroy the task <-> ctx relation |
8794 | * and mark the context dead. | |
71a851b4 | 8795 | */ |
63b6da39 PZ |
8796 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
8797 | put_ctx(child_ctx); /* cannot be last */ | |
8798 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
8799 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 8800 | |
211de6eb | 8801 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 8802 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8803 | |
211de6eb PZ |
8804 | if (clone_ctx) |
8805 | put_ctx(clone_ctx); | |
4a1c0f26 | 8806 | |
9f498cc5 | 8807 | /* |
cdd6c482 IM |
8808 | * Report the task dead after unscheduling the events so that we |
8809 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8810 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8811 | */ |
cdd6c482 | 8812 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8813 | |
ebf905fc | 8814 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 8815 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 8816 | |
a63eaf34 PM |
8817 | mutex_unlock(&child_ctx->mutex); |
8818 | ||
8819 | put_ctx(child_ctx); | |
9b51f66d IM |
8820 | } |
8821 | ||
8dc85d54 PZ |
8822 | /* |
8823 | * When a child task exits, feed back event values to parent events. | |
8824 | */ | |
8825 | void perf_event_exit_task(struct task_struct *child) | |
8826 | { | |
8882135b | 8827 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8828 | int ctxn; |
8829 | ||
8882135b PZ |
8830 | mutex_lock(&child->perf_event_mutex); |
8831 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8832 | owner_entry) { | |
8833 | list_del_init(&event->owner_entry); | |
8834 | ||
8835 | /* | |
8836 | * Ensure the list deletion is visible before we clear | |
8837 | * the owner, closes a race against perf_release() where | |
8838 | * we need to serialize on the owner->perf_event_mutex. | |
8839 | */ | |
f47c02c0 | 8840 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
8841 | } |
8842 | mutex_unlock(&child->perf_event_mutex); | |
8843 | ||
8dc85d54 PZ |
8844 | for_each_task_context_nr(ctxn) |
8845 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8846 | |
8847 | /* | |
8848 | * The perf_event_exit_task_context calls perf_event_task | |
8849 | * with child's task_ctx, which generates EXIT events for | |
8850 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8851 | * At this point we need to send EXIT events to cpu contexts. | |
8852 | */ | |
8853 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8854 | } |
8855 | ||
889ff015 FW |
8856 | static void perf_free_event(struct perf_event *event, |
8857 | struct perf_event_context *ctx) | |
8858 | { | |
8859 | struct perf_event *parent = event->parent; | |
8860 | ||
8861 | if (WARN_ON_ONCE(!parent)) | |
8862 | return; | |
8863 | ||
8864 | mutex_lock(&parent->child_mutex); | |
8865 | list_del_init(&event->child_list); | |
8866 | mutex_unlock(&parent->child_mutex); | |
8867 | ||
a6fa941d | 8868 | put_event(parent); |
889ff015 | 8869 | |
652884fe | 8870 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8871 | perf_group_detach(event); |
889ff015 | 8872 | list_del_event(event, ctx); |
652884fe | 8873 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8874 | free_event(event); |
8875 | } | |
8876 | ||
bbbee908 | 8877 | /* |
652884fe | 8878 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8879 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8880 | * |
8881 | * Not all locks are strictly required, but take them anyway to be nice and | |
8882 | * help out with the lockdep assertions. | |
bbbee908 | 8883 | */ |
cdd6c482 | 8884 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8885 | { |
8dc85d54 | 8886 | struct perf_event_context *ctx; |
cdd6c482 | 8887 | struct perf_event *event, *tmp; |
8dc85d54 | 8888 | int ctxn; |
bbbee908 | 8889 | |
8dc85d54 PZ |
8890 | for_each_task_context_nr(ctxn) { |
8891 | ctx = task->perf_event_ctxp[ctxn]; | |
8892 | if (!ctx) | |
8893 | continue; | |
bbbee908 | 8894 | |
8dc85d54 | 8895 | mutex_lock(&ctx->mutex); |
bbbee908 | 8896 | again: |
8dc85d54 PZ |
8897 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8898 | group_entry) | |
8899 | perf_free_event(event, ctx); | |
bbbee908 | 8900 | |
8dc85d54 PZ |
8901 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8902 | group_entry) | |
8903 | perf_free_event(event, ctx); | |
bbbee908 | 8904 | |
8dc85d54 PZ |
8905 | if (!list_empty(&ctx->pinned_groups) || |
8906 | !list_empty(&ctx->flexible_groups)) | |
8907 | goto again; | |
bbbee908 | 8908 | |
8dc85d54 | 8909 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8910 | |
8dc85d54 PZ |
8911 | put_ctx(ctx); |
8912 | } | |
889ff015 FW |
8913 | } |
8914 | ||
4e231c79 PZ |
8915 | void perf_event_delayed_put(struct task_struct *task) |
8916 | { | |
8917 | int ctxn; | |
8918 | ||
8919 | for_each_task_context_nr(ctxn) | |
8920 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8921 | } | |
8922 | ||
e03e7ee3 | 8923 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 8924 | { |
e03e7ee3 | 8925 | struct file *file; |
ffe8690c | 8926 | |
e03e7ee3 AS |
8927 | file = fget_raw(fd); |
8928 | if (!file) | |
8929 | return ERR_PTR(-EBADF); | |
ffe8690c | 8930 | |
e03e7ee3 AS |
8931 | if (file->f_op != &perf_fops) { |
8932 | fput(file); | |
8933 | return ERR_PTR(-EBADF); | |
8934 | } | |
ffe8690c | 8935 | |
e03e7ee3 | 8936 | return file; |
ffe8690c KX |
8937 | } |
8938 | ||
8939 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8940 | { | |
8941 | if (!event) | |
8942 | return ERR_PTR(-EINVAL); | |
8943 | ||
8944 | return &event->attr; | |
8945 | } | |
8946 | ||
97dee4f3 PZ |
8947 | /* |
8948 | * inherit a event from parent task to child task: | |
8949 | */ | |
8950 | static struct perf_event * | |
8951 | inherit_event(struct perf_event *parent_event, | |
8952 | struct task_struct *parent, | |
8953 | struct perf_event_context *parent_ctx, | |
8954 | struct task_struct *child, | |
8955 | struct perf_event *group_leader, | |
8956 | struct perf_event_context *child_ctx) | |
8957 | { | |
1929def9 | 8958 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8959 | struct perf_event *child_event; |
cee010ec | 8960 | unsigned long flags; |
97dee4f3 PZ |
8961 | |
8962 | /* | |
8963 | * Instead of creating recursive hierarchies of events, | |
8964 | * we link inherited events back to the original parent, | |
8965 | * which has a filp for sure, which we use as the reference | |
8966 | * count: | |
8967 | */ | |
8968 | if (parent_event->parent) | |
8969 | parent_event = parent_event->parent; | |
8970 | ||
8971 | child_event = perf_event_alloc(&parent_event->attr, | |
8972 | parent_event->cpu, | |
d580ff86 | 8973 | child, |
97dee4f3 | 8974 | group_leader, parent_event, |
79dff51e | 8975 | NULL, NULL, -1); |
97dee4f3 PZ |
8976 | if (IS_ERR(child_event)) |
8977 | return child_event; | |
a6fa941d | 8978 | |
c6e5b732 PZ |
8979 | /* |
8980 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
8981 | * must be under the same lock in order to serialize against | |
8982 | * perf_event_release_kernel(), such that either we must observe | |
8983 | * is_orphaned_event() or they will observe us on the child_list. | |
8984 | */ | |
8985 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
8986 | if (is_orphaned_event(parent_event) || |
8987 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 8988 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
8989 | free_event(child_event); |
8990 | return NULL; | |
8991 | } | |
8992 | ||
97dee4f3 PZ |
8993 | get_ctx(child_ctx); |
8994 | ||
8995 | /* | |
8996 | * Make the child state follow the state of the parent event, | |
8997 | * not its attr.disabled bit. We hold the parent's mutex, | |
8998 | * so we won't race with perf_event_{en, dis}able_family. | |
8999 | */ | |
1929def9 | 9000 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
9001 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
9002 | else | |
9003 | child_event->state = PERF_EVENT_STATE_OFF; | |
9004 | ||
9005 | if (parent_event->attr.freq) { | |
9006 | u64 sample_period = parent_event->hw.sample_period; | |
9007 | struct hw_perf_event *hwc = &child_event->hw; | |
9008 | ||
9009 | hwc->sample_period = sample_period; | |
9010 | hwc->last_period = sample_period; | |
9011 | ||
9012 | local64_set(&hwc->period_left, sample_period); | |
9013 | } | |
9014 | ||
9015 | child_event->ctx = child_ctx; | |
9016 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9017 | child_event->overflow_handler_context |
9018 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9019 | |
614b6780 TG |
9020 | /* |
9021 | * Precalculate sample_data sizes | |
9022 | */ | |
9023 | perf_event__header_size(child_event); | |
6844c09d | 9024 | perf_event__id_header_size(child_event); |
614b6780 | 9025 | |
97dee4f3 PZ |
9026 | /* |
9027 | * Link it up in the child's context: | |
9028 | */ | |
cee010ec | 9029 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9030 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9031 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9032 | |
97dee4f3 PZ |
9033 | /* |
9034 | * Link this into the parent event's child list | |
9035 | */ | |
97dee4f3 PZ |
9036 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9037 | mutex_unlock(&parent_event->child_mutex); | |
9038 | ||
9039 | return child_event; | |
9040 | } | |
9041 | ||
9042 | static int inherit_group(struct perf_event *parent_event, | |
9043 | struct task_struct *parent, | |
9044 | struct perf_event_context *parent_ctx, | |
9045 | struct task_struct *child, | |
9046 | struct perf_event_context *child_ctx) | |
9047 | { | |
9048 | struct perf_event *leader; | |
9049 | struct perf_event *sub; | |
9050 | struct perf_event *child_ctr; | |
9051 | ||
9052 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9053 | child, NULL, child_ctx); | |
9054 | if (IS_ERR(leader)) | |
9055 | return PTR_ERR(leader); | |
9056 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9057 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9058 | child, leader, child_ctx); | |
9059 | if (IS_ERR(child_ctr)) | |
9060 | return PTR_ERR(child_ctr); | |
9061 | } | |
9062 | return 0; | |
889ff015 FW |
9063 | } |
9064 | ||
9065 | static int | |
9066 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9067 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9068 | struct task_struct *child, int ctxn, |
889ff015 FW |
9069 | int *inherited_all) |
9070 | { | |
9071 | int ret; | |
8dc85d54 | 9072 | struct perf_event_context *child_ctx; |
889ff015 FW |
9073 | |
9074 | if (!event->attr.inherit) { | |
9075 | *inherited_all = 0; | |
9076 | return 0; | |
bbbee908 PZ |
9077 | } |
9078 | ||
fe4b04fa | 9079 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9080 | if (!child_ctx) { |
9081 | /* | |
9082 | * This is executed from the parent task context, so | |
9083 | * inherit events that have been marked for cloning. | |
9084 | * First allocate and initialize a context for the | |
9085 | * child. | |
9086 | */ | |
bbbee908 | 9087 | |
734df5ab | 9088 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9089 | if (!child_ctx) |
9090 | return -ENOMEM; | |
bbbee908 | 9091 | |
8dc85d54 | 9092 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9093 | } |
9094 | ||
9095 | ret = inherit_group(event, parent, parent_ctx, | |
9096 | child, child_ctx); | |
9097 | ||
9098 | if (ret) | |
9099 | *inherited_all = 0; | |
9100 | ||
9101 | return ret; | |
bbbee908 PZ |
9102 | } |
9103 | ||
9b51f66d | 9104 | /* |
cdd6c482 | 9105 | * Initialize the perf_event context in task_struct |
9b51f66d | 9106 | */ |
985c8dcb | 9107 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9108 | { |
889ff015 | 9109 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9110 | struct perf_event_context *cloned_ctx; |
9111 | struct perf_event *event; | |
9b51f66d | 9112 | struct task_struct *parent = current; |
564c2b21 | 9113 | int inherited_all = 1; |
dddd3379 | 9114 | unsigned long flags; |
6ab423e0 | 9115 | int ret = 0; |
9b51f66d | 9116 | |
8dc85d54 | 9117 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9118 | return 0; |
9119 | ||
ad3a37de | 9120 | /* |
25346b93 PM |
9121 | * If the parent's context is a clone, pin it so it won't get |
9122 | * swapped under us. | |
ad3a37de | 9123 | */ |
8dc85d54 | 9124 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9125 | if (!parent_ctx) |
9126 | return 0; | |
25346b93 | 9127 | |
ad3a37de PM |
9128 | /* |
9129 | * No need to check if parent_ctx != NULL here; since we saw | |
9130 | * it non-NULL earlier, the only reason for it to become NULL | |
9131 | * is if we exit, and since we're currently in the middle of | |
9132 | * a fork we can't be exiting at the same time. | |
9133 | */ | |
ad3a37de | 9134 | |
9b51f66d IM |
9135 | /* |
9136 | * Lock the parent list. No need to lock the child - not PID | |
9137 | * hashed yet and not running, so nobody can access it. | |
9138 | */ | |
d859e29f | 9139 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9140 | |
9141 | /* | |
9142 | * We dont have to disable NMIs - we are only looking at | |
9143 | * the list, not manipulating it: | |
9144 | */ | |
889ff015 | 9145 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9146 | ret = inherit_task_group(event, parent, parent_ctx, |
9147 | child, ctxn, &inherited_all); | |
889ff015 FW |
9148 | if (ret) |
9149 | break; | |
9150 | } | |
b93f7978 | 9151 | |
dddd3379 TG |
9152 | /* |
9153 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9154 | * to allocations, but we need to prevent rotation because | |
9155 | * rotate_ctx() will change the list from interrupt context. | |
9156 | */ | |
9157 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9158 | parent_ctx->rotate_disable = 1; | |
9159 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9160 | ||
889ff015 | 9161 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9162 | ret = inherit_task_group(event, parent, parent_ctx, |
9163 | child, ctxn, &inherited_all); | |
889ff015 | 9164 | if (ret) |
9b51f66d | 9165 | break; |
564c2b21 PM |
9166 | } |
9167 | ||
dddd3379 TG |
9168 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9169 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9170 | |
8dc85d54 | 9171 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9172 | |
05cbaa28 | 9173 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9174 | /* |
9175 | * Mark the child context as a clone of the parent | |
9176 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9177 | * |
9178 | * Note that if the parent is a clone, the holding of | |
9179 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9180 | */ |
c5ed5145 | 9181 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9182 | if (cloned_ctx) { |
9183 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9184 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9185 | } else { |
9186 | child_ctx->parent_ctx = parent_ctx; | |
9187 | child_ctx->parent_gen = parent_ctx->generation; | |
9188 | } | |
9189 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9190 | } |
9191 | ||
c5ed5145 | 9192 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9193 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9194 | |
25346b93 | 9195 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9196 | put_ctx(parent_ctx); |
ad3a37de | 9197 | |
6ab423e0 | 9198 | return ret; |
9b51f66d IM |
9199 | } |
9200 | ||
8dc85d54 PZ |
9201 | /* |
9202 | * Initialize the perf_event context in task_struct | |
9203 | */ | |
9204 | int perf_event_init_task(struct task_struct *child) | |
9205 | { | |
9206 | int ctxn, ret; | |
9207 | ||
8550d7cb ON |
9208 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9209 | mutex_init(&child->perf_event_mutex); | |
9210 | INIT_LIST_HEAD(&child->perf_event_list); | |
9211 | ||
8dc85d54 PZ |
9212 | for_each_task_context_nr(ctxn) { |
9213 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9214 | if (ret) { |
9215 | perf_event_free_task(child); | |
8dc85d54 | 9216 | return ret; |
6c72e350 | 9217 | } |
8dc85d54 PZ |
9218 | } |
9219 | ||
9220 | return 0; | |
9221 | } | |
9222 | ||
220b140b PM |
9223 | static void __init perf_event_init_all_cpus(void) |
9224 | { | |
b28ab83c | 9225 | struct swevent_htable *swhash; |
220b140b | 9226 | int cpu; |
220b140b PM |
9227 | |
9228 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9229 | swhash = &per_cpu(swevent_htable, cpu); |
9230 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9231 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9232 | } |
9233 | } | |
9234 | ||
0db0628d | 9235 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9236 | { |
108b02cf | 9237 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9238 | |
b28ab83c | 9239 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 9240 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
9241 | struct swevent_hlist *hlist; |
9242 | ||
b28ab83c PZ |
9243 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9244 | WARN_ON(!hlist); | |
9245 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9246 | } |
b28ab83c | 9247 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9248 | } |
9249 | ||
2965faa5 | 9250 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9251 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9252 | { |
108b02cf | 9253 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9254 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9255 | struct perf_event *event; | |
0793a61d | 9256 | |
fae3fde6 PZ |
9257 | raw_spin_lock(&ctx->lock); |
9258 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9259 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9260 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9261 | } |
108b02cf PZ |
9262 | |
9263 | static void perf_event_exit_cpu_context(int cpu) | |
9264 | { | |
9265 | struct perf_event_context *ctx; | |
9266 | struct pmu *pmu; | |
9267 | int idx; | |
9268 | ||
9269 | idx = srcu_read_lock(&pmus_srcu); | |
9270 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9271 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9272 | |
9273 | mutex_lock(&ctx->mutex); | |
9274 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9275 | mutex_unlock(&ctx->mutex); | |
9276 | } | |
9277 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9278 | } |
9279 | ||
cdd6c482 | 9280 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9281 | { |
e3703f8c | 9282 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9283 | } |
9284 | #else | |
cdd6c482 | 9285 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9286 | #endif |
9287 | ||
c277443c PZ |
9288 | static int |
9289 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9290 | { | |
9291 | int cpu; | |
9292 | ||
9293 | for_each_online_cpu(cpu) | |
9294 | perf_event_exit_cpu(cpu); | |
9295 | ||
9296 | return NOTIFY_OK; | |
9297 | } | |
9298 | ||
9299 | /* | |
9300 | * Run the perf reboot notifier at the very last possible moment so that | |
9301 | * the generic watchdog code runs as long as possible. | |
9302 | */ | |
9303 | static struct notifier_block perf_reboot_notifier = { | |
9304 | .notifier_call = perf_reboot, | |
9305 | .priority = INT_MIN, | |
9306 | }; | |
9307 | ||
0db0628d | 9308 | static int |
0793a61d TG |
9309 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9310 | { | |
9311 | unsigned int cpu = (long)hcpu; | |
9312 | ||
4536e4d1 | 9313 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9314 | |
9315 | case CPU_UP_PREPARE: | |
cdd6c482 | 9316 | perf_event_init_cpu(cpu); |
0793a61d TG |
9317 | break; |
9318 | ||
9319 | case CPU_DOWN_PREPARE: | |
cdd6c482 | 9320 | perf_event_exit_cpu(cpu); |
0793a61d | 9321 | break; |
0793a61d TG |
9322 | default: |
9323 | break; | |
9324 | } | |
9325 | ||
9326 | return NOTIFY_OK; | |
9327 | } | |
9328 | ||
cdd6c482 | 9329 | void __init perf_event_init(void) |
0793a61d | 9330 | { |
3c502e7a JW |
9331 | int ret; |
9332 | ||
2e80a82a PZ |
9333 | idr_init(&pmu_idr); |
9334 | ||
220b140b | 9335 | perf_event_init_all_cpus(); |
b0a873eb | 9336 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9337 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9338 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9339 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9340 | perf_tp_register(); |
9341 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9342 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9343 | |
9344 | ret = init_hw_breakpoint(); | |
9345 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9346 | |
9347 | /* do not patch jump label more than once per second */ | |
9348 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9349 | |
9350 | /* | |
9351 | * Build time assertion that we keep the data_head at the intended | |
9352 | * location. IOW, validation we got the __reserved[] size right. | |
9353 | */ | |
9354 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9355 | != 1024); | |
0793a61d | 9356 | } |
abe43400 | 9357 | |
fd979c01 CS |
9358 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9359 | char *page) | |
9360 | { | |
9361 | struct perf_pmu_events_attr *pmu_attr = | |
9362 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9363 | ||
9364 | if (pmu_attr->event_str) | |
9365 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9366 | ||
9367 | return 0; | |
9368 | } | |
9369 | ||
abe43400 PZ |
9370 | static int __init perf_event_sysfs_init(void) |
9371 | { | |
9372 | struct pmu *pmu; | |
9373 | int ret; | |
9374 | ||
9375 | mutex_lock(&pmus_lock); | |
9376 | ||
9377 | ret = bus_register(&pmu_bus); | |
9378 | if (ret) | |
9379 | goto unlock; | |
9380 | ||
9381 | list_for_each_entry(pmu, &pmus, entry) { | |
9382 | if (!pmu->name || pmu->type < 0) | |
9383 | continue; | |
9384 | ||
9385 | ret = pmu_dev_alloc(pmu); | |
9386 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9387 | } | |
9388 | pmu_bus_running = 1; | |
9389 | ret = 0; | |
9390 | ||
9391 | unlock: | |
9392 | mutex_unlock(&pmus_lock); | |
9393 | ||
9394 | return ret; | |
9395 | } | |
9396 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9397 | |
9398 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9399 | static struct cgroup_subsys_state * |
9400 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9401 | { |
9402 | struct perf_cgroup *jc; | |
e5d1367f | 9403 | |
1b15d055 | 9404 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9405 | if (!jc) |
9406 | return ERR_PTR(-ENOMEM); | |
9407 | ||
e5d1367f SE |
9408 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9409 | if (!jc->info) { | |
9410 | kfree(jc); | |
9411 | return ERR_PTR(-ENOMEM); | |
9412 | } | |
9413 | ||
e5d1367f SE |
9414 | return &jc->css; |
9415 | } | |
9416 | ||
eb95419b | 9417 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9418 | { |
eb95419b TH |
9419 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9420 | ||
e5d1367f SE |
9421 | free_percpu(jc->info); |
9422 | kfree(jc); | |
9423 | } | |
9424 | ||
9425 | static int __perf_cgroup_move(void *info) | |
9426 | { | |
9427 | struct task_struct *task = info; | |
ddaaf4e2 | 9428 | rcu_read_lock(); |
e5d1367f | 9429 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9430 | rcu_read_unlock(); |
e5d1367f SE |
9431 | return 0; |
9432 | } | |
9433 | ||
1f7dd3e5 | 9434 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9435 | { |
bb9d97b6 | 9436 | struct task_struct *task; |
1f7dd3e5 | 9437 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9438 | |
1f7dd3e5 | 9439 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9440 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9441 | } |
9442 | ||
073219e9 | 9443 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9444 | .css_alloc = perf_cgroup_css_alloc, |
9445 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9446 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9447 | }; |
9448 | #endif /* CONFIG_CGROUP_PERF */ |