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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) { | |
0da4cf3e PZ |
67 | /* -EAGAIN */ |
68 | if (task_cpu(p) != smp_processor_id()) | |
69 | return; | |
70 | ||
71 | /* | |
72 | * Now that we're on right CPU with IRQs disabled, we can test | |
73 | * if we hit the right task without races. | |
74 | */ | |
75 | ||
76 | tfc->ret = -ESRCH; /* No such (running) process */ | |
77 | if (p != current) | |
fe4b04fa PZ |
78 | return; |
79 | } | |
80 | ||
81 | tfc->ret = tfc->func(tfc->info); | |
82 | } | |
83 | ||
84 | /** | |
85 | * task_function_call - call a function on the cpu on which a task runs | |
86 | * @p: the task to evaluate | |
87 | * @func: the function to be called | |
88 | * @info: the function call argument | |
89 | * | |
90 | * Calls the function @func when the task is currently running. This might | |
91 | * be on the current CPU, which just calls the function directly | |
92 | * | |
93 | * returns: @func return value, or | |
94 | * -ESRCH - when the process isn't running | |
95 | * -EAGAIN - when the process moved away | |
96 | */ | |
97 | static int | |
272325c4 | 98 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
99 | { |
100 | struct remote_function_call data = { | |
e7e7ee2e IM |
101 | .p = p, |
102 | .func = func, | |
103 | .info = info, | |
0da4cf3e | 104 | .ret = -EAGAIN, |
fe4b04fa | 105 | }; |
0da4cf3e | 106 | int ret; |
fe4b04fa | 107 | |
0da4cf3e PZ |
108 | do { |
109 | ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
110 | if (!ret) | |
111 | ret = data.ret; | |
112 | } while (ret == -EAGAIN); | |
fe4b04fa | 113 | |
0da4cf3e | 114 | return ret; |
fe4b04fa PZ |
115 | } |
116 | ||
117 | /** | |
118 | * cpu_function_call - call a function on the cpu | |
119 | * @func: the function to be called | |
120 | * @info: the function call argument | |
121 | * | |
122 | * Calls the function @func on the remote cpu. | |
123 | * | |
124 | * returns: @func return value or -ENXIO when the cpu is offline | |
125 | */ | |
272325c4 | 126 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
127 | { |
128 | struct remote_function_call data = { | |
e7e7ee2e IM |
129 | .p = NULL, |
130 | .func = func, | |
131 | .info = info, | |
132 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
133 | }; |
134 | ||
135 | smp_call_function_single(cpu, remote_function, &data, 1); | |
136 | ||
137 | return data.ret; | |
138 | } | |
139 | ||
fae3fde6 PZ |
140 | static inline struct perf_cpu_context * |
141 | __get_cpu_context(struct perf_event_context *ctx) | |
142 | { | |
143 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
144 | } | |
145 | ||
146 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
147 | struct perf_event_context *ctx) | |
0017960f | 148 | { |
fae3fde6 PZ |
149 | raw_spin_lock(&cpuctx->ctx.lock); |
150 | if (ctx) | |
151 | raw_spin_lock(&ctx->lock); | |
152 | } | |
153 | ||
154 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
155 | struct perf_event_context *ctx) | |
156 | { | |
157 | if (ctx) | |
158 | raw_spin_unlock(&ctx->lock); | |
159 | raw_spin_unlock(&cpuctx->ctx.lock); | |
160 | } | |
161 | ||
63b6da39 PZ |
162 | #define TASK_TOMBSTONE ((void *)-1L) |
163 | ||
164 | static bool is_kernel_event(struct perf_event *event) | |
165 | { | |
f47c02c0 | 166 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
167 | } |
168 | ||
39a43640 PZ |
169 | /* |
170 | * On task ctx scheduling... | |
171 | * | |
172 | * When !ctx->nr_events a task context will not be scheduled. This means | |
173 | * we can disable the scheduler hooks (for performance) without leaving | |
174 | * pending task ctx state. | |
175 | * | |
176 | * This however results in two special cases: | |
177 | * | |
178 | * - removing the last event from a task ctx; this is relatively straight | |
179 | * forward and is done in __perf_remove_from_context. | |
180 | * | |
181 | * - adding the first event to a task ctx; this is tricky because we cannot | |
182 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
183 | * See perf_install_in_context(). | |
184 | * | |
39a43640 PZ |
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 | 214 | if (ctx->task != current) { |
0da4cf3e | 215 | ret = -ESRCH; |
63b6da39 PZ |
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 | ||
63b6da39 PZ |
279 | if (task == TASK_TOMBSTONE) |
280 | return; | |
281 | ||
a096309b | 282 | again: |
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; | |
a096309b PZ |
292 | if (task == TASK_TOMBSTONE) { |
293 | raw_spin_unlock_irq(&ctx->lock); | |
294 | return; | |
0017960f | 295 | } |
a096309b PZ |
296 | if (ctx->is_active) { |
297 | raw_spin_unlock_irq(&ctx->lock); | |
298 | goto again; | |
299 | } | |
300 | func(event, NULL, ctx, data); | |
0017960f PZ |
301 | raw_spin_unlock_irq(&ctx->lock); |
302 | } | |
303 | ||
e5d1367f SE |
304 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
305 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
306 | PERF_FLAG_PID_CGROUP |\ |
307 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 308 | |
bce38cd5 SE |
309 | /* |
310 | * branch priv levels that need permission checks | |
311 | */ | |
312 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
313 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
314 | PERF_SAMPLE_BRANCH_HV) | |
315 | ||
0b3fcf17 SE |
316 | enum event_type_t { |
317 | EVENT_FLEXIBLE = 0x1, | |
318 | EVENT_PINNED = 0x2, | |
3cbaa590 | 319 | EVENT_TIME = 0x4, |
0b3fcf17 SE |
320 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
321 | }; | |
322 | ||
e5d1367f SE |
323 | /* |
324 | * perf_sched_events : >0 events exist | |
325 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
326 | */ | |
9107c89e PZ |
327 | |
328 | static void perf_sched_delayed(struct work_struct *work); | |
329 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
330 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
331 | static DEFINE_MUTEX(perf_sched_mutex); | |
332 | static atomic_t perf_sched_count; | |
333 | ||
e5d1367f | 334 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 335 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 336 | |
cdd6c482 IM |
337 | static atomic_t nr_mmap_events __read_mostly; |
338 | static atomic_t nr_comm_events __read_mostly; | |
339 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 340 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 341 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 342 | |
108b02cf PZ |
343 | static LIST_HEAD(pmus); |
344 | static DEFINE_MUTEX(pmus_lock); | |
345 | static struct srcu_struct pmus_srcu; | |
346 | ||
0764771d | 347 | /* |
cdd6c482 | 348 | * perf event paranoia level: |
0fbdea19 IM |
349 | * -1 - not paranoid at all |
350 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 351 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 352 | * 2 - disallow kernel profiling for unpriv |
0764771d | 353 | */ |
cdd6c482 | 354 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 355 | |
20443384 FW |
356 | /* Minimum for 512 kiB + 1 user control page */ |
357 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
358 | |
359 | /* | |
cdd6c482 | 360 | * max perf event sample rate |
df58ab24 | 361 | */ |
14c63f17 DH |
362 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
363 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
364 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
365 | ||
366 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
367 | ||
368 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
369 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
370 | ||
d9494cb4 PZ |
371 | static int perf_sample_allowed_ns __read_mostly = |
372 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 373 | |
18ab2cd3 | 374 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
375 | { |
376 | u64 tmp = perf_sample_period_ns; | |
377 | ||
378 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 379 | do_div(tmp, 100); |
d9494cb4 | 380 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 381 | } |
163ec435 | 382 | |
9e630205 SE |
383 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
384 | ||
163ec435 PZ |
385 | int perf_proc_update_handler(struct ctl_table *table, int write, |
386 | void __user *buffer, size_t *lenp, | |
387 | loff_t *ppos) | |
388 | { | |
723478c8 | 389 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
390 | |
391 | if (ret || !write) | |
392 | return ret; | |
393 | ||
394 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
395 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
396 | update_perf_cpu_limits(); | |
397 | ||
398 | return 0; | |
399 | } | |
400 | ||
401 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
402 | ||
403 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
404 | void __user *buffer, size_t *lenp, | |
405 | loff_t *ppos) | |
406 | { | |
407 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
408 | ||
409 | if (ret || !write) | |
410 | return ret; | |
411 | ||
412 | update_perf_cpu_limits(); | |
163ec435 PZ |
413 | |
414 | return 0; | |
415 | } | |
1ccd1549 | 416 | |
14c63f17 DH |
417 | /* |
418 | * perf samples are done in some very critical code paths (NMIs). | |
419 | * If they take too much CPU time, the system can lock up and not | |
420 | * get any real work done. This will drop the sample rate when | |
421 | * we detect that events are taking too long. | |
422 | */ | |
423 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 424 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 425 | |
6a02ad66 | 426 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 427 | { |
6a02ad66 | 428 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 429 | u64 avg_local_sample_len; |
e5302920 | 430 | u64 local_samples_len; |
6a02ad66 | 431 | |
4a32fea9 | 432 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
433 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
434 | ||
435 | printk_ratelimited(KERN_WARNING | |
436 | "perf interrupt took too long (%lld > %lld), lowering " | |
437 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 438 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
439 | sysctl_perf_event_sample_rate); |
440 | } | |
441 | ||
442 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
443 | ||
444 | void perf_sample_event_took(u64 sample_len_ns) | |
445 | { | |
d9494cb4 | 446 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
447 | u64 avg_local_sample_len; |
448 | u64 local_samples_len; | |
14c63f17 | 449 | |
d9494cb4 | 450 | if (allowed_ns == 0) |
14c63f17 DH |
451 | return; |
452 | ||
453 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 454 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
455 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
456 | local_samples_len += sample_len_ns; | |
4a32fea9 | 457 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
458 | |
459 | /* | |
460 | * note: this will be biased artifically low until we have | |
461 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
462 | * from having to maintain a count. | |
463 | */ | |
464 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
465 | ||
d9494cb4 | 466 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
467 | return; |
468 | ||
469 | if (max_samples_per_tick <= 1) | |
470 | return; | |
471 | ||
472 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
473 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
474 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
475 | ||
14c63f17 | 476 | update_perf_cpu_limits(); |
6a02ad66 | 477 | |
cd578abb PZ |
478 | if (!irq_work_queue(&perf_duration_work)) { |
479 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
480 | "kernel.perf_event_max_sample_rate to %d\n", | |
481 | avg_local_sample_len, allowed_ns >> 1, | |
482 | sysctl_perf_event_sample_rate); | |
483 | } | |
14c63f17 DH |
484 | } |
485 | ||
cdd6c482 | 486 | static atomic64_t perf_event_id; |
a96bbc16 | 487 | |
0b3fcf17 SE |
488 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
489 | enum event_type_t event_type); | |
490 | ||
491 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
492 | enum event_type_t event_type, |
493 | struct task_struct *task); | |
494 | ||
495 | static void update_context_time(struct perf_event_context *ctx); | |
496 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 497 | |
cdd6c482 | 498 | void __weak perf_event_print_debug(void) { } |
0793a61d | 499 | |
84c79910 | 500 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 501 | { |
84c79910 | 502 | return "pmu"; |
0793a61d TG |
503 | } |
504 | ||
0b3fcf17 SE |
505 | static inline u64 perf_clock(void) |
506 | { | |
507 | return local_clock(); | |
508 | } | |
509 | ||
34f43927 PZ |
510 | static inline u64 perf_event_clock(struct perf_event *event) |
511 | { | |
512 | return event->clock(); | |
513 | } | |
514 | ||
e5d1367f SE |
515 | #ifdef CONFIG_CGROUP_PERF |
516 | ||
e5d1367f SE |
517 | static inline bool |
518 | perf_cgroup_match(struct perf_event *event) | |
519 | { | |
520 | struct perf_event_context *ctx = event->ctx; | |
521 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
522 | ||
ef824fa1 TH |
523 | /* @event doesn't care about cgroup */ |
524 | if (!event->cgrp) | |
525 | return true; | |
526 | ||
527 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
528 | if (!cpuctx->cgrp) | |
529 | return false; | |
530 | ||
531 | /* | |
532 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
533 | * also enabled for all its descendant cgroups. If @cpuctx's | |
534 | * cgroup is a descendant of @event's (the test covers identity | |
535 | * case), it's a match. | |
536 | */ | |
537 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
538 | event->cgrp->css.cgroup); | |
e5d1367f SE |
539 | } |
540 | ||
e5d1367f SE |
541 | static inline void perf_detach_cgroup(struct perf_event *event) |
542 | { | |
4e2ba650 | 543 | css_put(&event->cgrp->css); |
e5d1367f SE |
544 | event->cgrp = NULL; |
545 | } | |
546 | ||
547 | static inline int is_cgroup_event(struct perf_event *event) | |
548 | { | |
549 | return event->cgrp != NULL; | |
550 | } | |
551 | ||
552 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
553 | { | |
554 | struct perf_cgroup_info *t; | |
555 | ||
556 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
557 | return t->time; | |
558 | } | |
559 | ||
560 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
561 | { | |
562 | struct perf_cgroup_info *info; | |
563 | u64 now; | |
564 | ||
565 | now = perf_clock(); | |
566 | ||
567 | info = this_cpu_ptr(cgrp->info); | |
568 | ||
569 | info->time += now - info->timestamp; | |
570 | info->timestamp = now; | |
571 | } | |
572 | ||
573 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
574 | { | |
575 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
576 | if (cgrp_out) | |
577 | __update_cgrp_time(cgrp_out); | |
578 | } | |
579 | ||
580 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
581 | { | |
3f7cce3c SE |
582 | struct perf_cgroup *cgrp; |
583 | ||
e5d1367f | 584 | /* |
3f7cce3c SE |
585 | * ensure we access cgroup data only when needed and |
586 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 587 | */ |
3f7cce3c | 588 | if (!is_cgroup_event(event)) |
e5d1367f SE |
589 | return; |
590 | ||
614e4c4e | 591 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
592 | /* |
593 | * Do not update time when cgroup is not active | |
594 | */ | |
595 | if (cgrp == event->cgrp) | |
596 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
597 | } |
598 | ||
599 | static inline void | |
3f7cce3c SE |
600 | perf_cgroup_set_timestamp(struct task_struct *task, |
601 | struct perf_event_context *ctx) | |
e5d1367f SE |
602 | { |
603 | struct perf_cgroup *cgrp; | |
604 | struct perf_cgroup_info *info; | |
605 | ||
3f7cce3c SE |
606 | /* |
607 | * ctx->lock held by caller | |
608 | * ensure we do not access cgroup data | |
609 | * unless we have the cgroup pinned (css_get) | |
610 | */ | |
611 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
612 | return; |
613 | ||
614e4c4e | 614 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 615 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 616 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
617 | } |
618 | ||
619 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
620 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
621 | ||
622 | /* | |
623 | * reschedule events based on the cgroup constraint of task. | |
624 | * | |
625 | * mode SWOUT : schedule out everything | |
626 | * mode SWIN : schedule in based on cgroup for next | |
627 | */ | |
18ab2cd3 | 628 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
629 | { |
630 | struct perf_cpu_context *cpuctx; | |
631 | struct pmu *pmu; | |
632 | unsigned long flags; | |
633 | ||
634 | /* | |
635 | * disable interrupts to avoid geting nr_cgroup | |
636 | * changes via __perf_event_disable(). Also | |
637 | * avoids preemption. | |
638 | */ | |
639 | local_irq_save(flags); | |
640 | ||
641 | /* | |
642 | * we reschedule only in the presence of cgroup | |
643 | * constrained events. | |
644 | */ | |
e5d1367f SE |
645 | |
646 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 647 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
648 | if (cpuctx->unique_pmu != pmu) |
649 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 650 | |
e5d1367f SE |
651 | /* |
652 | * perf_cgroup_events says at least one | |
653 | * context on this CPU has cgroup events. | |
654 | * | |
655 | * ctx->nr_cgroups reports the number of cgroup | |
656 | * events for a context. | |
657 | */ | |
658 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
659 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
660 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
661 | |
662 | if (mode & PERF_CGROUP_SWOUT) { | |
663 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
664 | /* | |
665 | * must not be done before ctxswout due | |
666 | * to event_filter_match() in event_sched_out() | |
667 | */ | |
668 | cpuctx->cgrp = NULL; | |
669 | } | |
670 | ||
671 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 672 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
673 | /* |
674 | * set cgrp before ctxsw in to allow | |
675 | * event_filter_match() to not have to pass | |
676 | * task around | |
614e4c4e SE |
677 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
678 | * because cgorup events are only per-cpu | |
e5d1367f | 679 | */ |
614e4c4e | 680 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
681 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
682 | } | |
facc4307 PZ |
683 | perf_pmu_enable(cpuctx->ctx.pmu); |
684 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 685 | } |
e5d1367f SE |
686 | } |
687 | ||
e5d1367f SE |
688 | local_irq_restore(flags); |
689 | } | |
690 | ||
a8d757ef SE |
691 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
692 | struct task_struct *next) | |
e5d1367f | 693 | { |
a8d757ef SE |
694 | struct perf_cgroup *cgrp1; |
695 | struct perf_cgroup *cgrp2 = NULL; | |
696 | ||
ddaaf4e2 | 697 | rcu_read_lock(); |
a8d757ef SE |
698 | /* |
699 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
700 | * we do not need to pass the ctx here because we know |
701 | * we are holding the rcu lock | |
a8d757ef | 702 | */ |
614e4c4e | 703 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 704 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
705 | |
706 | /* | |
707 | * only schedule out current cgroup events if we know | |
708 | * that we are switching to a different cgroup. Otherwise, | |
709 | * do no touch the cgroup events. | |
710 | */ | |
711 | if (cgrp1 != cgrp2) | |
712 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
713 | |
714 | rcu_read_unlock(); | |
e5d1367f SE |
715 | } |
716 | ||
a8d757ef SE |
717 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
718 | struct task_struct *task) | |
e5d1367f | 719 | { |
a8d757ef SE |
720 | struct perf_cgroup *cgrp1; |
721 | struct perf_cgroup *cgrp2 = NULL; | |
722 | ||
ddaaf4e2 | 723 | rcu_read_lock(); |
a8d757ef SE |
724 | /* |
725 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
726 | * we do not need to pass the ctx here because we know |
727 | * we are holding the rcu lock | |
a8d757ef | 728 | */ |
614e4c4e | 729 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 730 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
731 | |
732 | /* | |
733 | * only need to schedule in cgroup events if we are changing | |
734 | * cgroup during ctxsw. Cgroup events were not scheduled | |
735 | * out of ctxsw out if that was not the case. | |
736 | */ | |
737 | if (cgrp1 != cgrp2) | |
738 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
739 | |
740 | rcu_read_unlock(); | |
e5d1367f SE |
741 | } |
742 | ||
743 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
744 | struct perf_event_attr *attr, | |
745 | struct perf_event *group_leader) | |
746 | { | |
747 | struct perf_cgroup *cgrp; | |
748 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
749 | struct fd f = fdget(fd); |
750 | int ret = 0; | |
e5d1367f | 751 | |
2903ff01 | 752 | if (!f.file) |
e5d1367f SE |
753 | return -EBADF; |
754 | ||
b583043e | 755 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 756 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
757 | if (IS_ERR(css)) { |
758 | ret = PTR_ERR(css); | |
759 | goto out; | |
760 | } | |
e5d1367f SE |
761 | |
762 | cgrp = container_of(css, struct perf_cgroup, css); | |
763 | event->cgrp = cgrp; | |
764 | ||
765 | /* | |
766 | * all events in a group must monitor | |
767 | * the same cgroup because a task belongs | |
768 | * to only one perf cgroup at a time | |
769 | */ | |
770 | if (group_leader && group_leader->cgrp != cgrp) { | |
771 | perf_detach_cgroup(event); | |
772 | ret = -EINVAL; | |
e5d1367f | 773 | } |
3db272c0 | 774 | out: |
2903ff01 | 775 | fdput(f); |
e5d1367f SE |
776 | return ret; |
777 | } | |
778 | ||
779 | static inline void | |
780 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
781 | { | |
782 | struct perf_cgroup_info *t; | |
783 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
784 | event->shadow_ctx_time = now - t->timestamp; | |
785 | } | |
786 | ||
787 | static inline void | |
788 | perf_cgroup_defer_enabled(struct perf_event *event) | |
789 | { | |
790 | /* | |
791 | * when the current task's perf cgroup does not match | |
792 | * the event's, we need to remember to call the | |
793 | * perf_mark_enable() function the first time a task with | |
794 | * a matching perf cgroup is scheduled in. | |
795 | */ | |
796 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
797 | event->cgrp_defer_enabled = 1; | |
798 | } | |
799 | ||
800 | static inline void | |
801 | perf_cgroup_mark_enabled(struct perf_event *event, | |
802 | struct perf_event_context *ctx) | |
803 | { | |
804 | struct perf_event *sub; | |
805 | u64 tstamp = perf_event_time(event); | |
806 | ||
807 | if (!event->cgrp_defer_enabled) | |
808 | return; | |
809 | ||
810 | event->cgrp_defer_enabled = 0; | |
811 | ||
812 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
813 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
814 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
815 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
816 | sub->cgrp_defer_enabled = 0; | |
817 | } | |
818 | } | |
819 | } | |
820 | #else /* !CONFIG_CGROUP_PERF */ | |
821 | ||
822 | static inline bool | |
823 | perf_cgroup_match(struct perf_event *event) | |
824 | { | |
825 | return true; | |
826 | } | |
827 | ||
828 | static inline void perf_detach_cgroup(struct perf_event *event) | |
829 | {} | |
830 | ||
831 | static inline int is_cgroup_event(struct perf_event *event) | |
832 | { | |
833 | return 0; | |
834 | } | |
835 | ||
836 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
837 | { | |
838 | return 0; | |
839 | } | |
840 | ||
841 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
842 | { | |
843 | } | |
844 | ||
845 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
846 | { | |
847 | } | |
848 | ||
a8d757ef SE |
849 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
850 | struct task_struct *next) | |
e5d1367f SE |
851 | { |
852 | } | |
853 | ||
a8d757ef SE |
854 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
855 | struct task_struct *task) | |
e5d1367f SE |
856 | { |
857 | } | |
858 | ||
859 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
860 | struct perf_event_attr *attr, | |
861 | struct perf_event *group_leader) | |
862 | { | |
863 | return -EINVAL; | |
864 | } | |
865 | ||
866 | static inline void | |
3f7cce3c SE |
867 | perf_cgroup_set_timestamp(struct task_struct *task, |
868 | struct perf_event_context *ctx) | |
e5d1367f SE |
869 | { |
870 | } | |
871 | ||
872 | void | |
873 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
874 | { | |
875 | } | |
876 | ||
877 | static inline void | |
878 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
879 | { | |
880 | } | |
881 | ||
882 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
883 | { | |
884 | return 0; | |
885 | } | |
886 | ||
887 | static inline void | |
888 | perf_cgroup_defer_enabled(struct perf_event *event) | |
889 | { | |
890 | } | |
891 | ||
892 | static inline void | |
893 | perf_cgroup_mark_enabled(struct perf_event *event, | |
894 | struct perf_event_context *ctx) | |
895 | { | |
896 | } | |
897 | #endif | |
898 | ||
9e630205 SE |
899 | /* |
900 | * set default to be dependent on timer tick just | |
901 | * like original code | |
902 | */ | |
903 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
904 | /* | |
905 | * function must be called with interrupts disbled | |
906 | */ | |
272325c4 | 907 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
908 | { |
909 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
910 | int rotations = 0; |
911 | ||
912 | WARN_ON(!irqs_disabled()); | |
913 | ||
914 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
915 | rotations = perf_rotate_context(cpuctx); |
916 | ||
4cfafd30 PZ |
917 | raw_spin_lock(&cpuctx->hrtimer_lock); |
918 | if (rotations) | |
9e630205 | 919 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
920 | else |
921 | cpuctx->hrtimer_active = 0; | |
922 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 923 | |
4cfafd30 | 924 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
925 | } |
926 | ||
272325c4 | 927 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 928 | { |
272325c4 | 929 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 930 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 931 | u64 interval; |
9e630205 SE |
932 | |
933 | /* no multiplexing needed for SW PMU */ | |
934 | if (pmu->task_ctx_nr == perf_sw_context) | |
935 | return; | |
936 | ||
62b85639 SE |
937 | /* |
938 | * check default is sane, if not set then force to | |
939 | * default interval (1/tick) | |
940 | */ | |
272325c4 PZ |
941 | interval = pmu->hrtimer_interval_ms; |
942 | if (interval < 1) | |
943 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 944 | |
272325c4 | 945 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 946 | |
4cfafd30 PZ |
947 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
948 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 949 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
950 | } |
951 | ||
272325c4 | 952 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 953 | { |
272325c4 | 954 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 955 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 956 | unsigned long flags; |
9e630205 SE |
957 | |
958 | /* not for SW PMU */ | |
959 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 960 | return 0; |
9e630205 | 961 | |
4cfafd30 PZ |
962 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
963 | if (!cpuctx->hrtimer_active) { | |
964 | cpuctx->hrtimer_active = 1; | |
965 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
966 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
967 | } | |
968 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 969 | |
272325c4 | 970 | return 0; |
9e630205 SE |
971 | } |
972 | ||
33696fc0 | 973 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 974 | { |
33696fc0 PZ |
975 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
976 | if (!(*count)++) | |
977 | pmu->pmu_disable(pmu); | |
9e35ad38 | 978 | } |
9e35ad38 | 979 | |
33696fc0 | 980 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 981 | { |
33696fc0 PZ |
982 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
983 | if (!--(*count)) | |
984 | pmu->pmu_enable(pmu); | |
9e35ad38 | 985 | } |
9e35ad38 | 986 | |
2fde4f94 | 987 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
988 | |
989 | /* | |
2fde4f94 MR |
990 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
991 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
992 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
993 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 994 | */ |
2fde4f94 | 995 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 996 | { |
2fde4f94 | 997 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 998 | |
e9d2b064 | 999 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 1000 | |
2fde4f94 MR |
1001 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1002 | ||
1003 | list_add(&ctx->active_ctx_list, head); | |
1004 | } | |
1005 | ||
1006 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1007 | { | |
1008 | WARN_ON(!irqs_disabled()); | |
1009 | ||
1010 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1011 | ||
1012 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1013 | } |
9e35ad38 | 1014 | |
cdd6c482 | 1015 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1016 | { |
e5289d4a | 1017 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1018 | } |
1019 | ||
4af57ef2 YZ |
1020 | static void free_ctx(struct rcu_head *head) |
1021 | { | |
1022 | struct perf_event_context *ctx; | |
1023 | ||
1024 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1025 | kfree(ctx->task_ctx_data); | |
1026 | kfree(ctx); | |
1027 | } | |
1028 | ||
cdd6c482 | 1029 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1030 | { |
564c2b21 PM |
1031 | if (atomic_dec_and_test(&ctx->refcount)) { |
1032 | if (ctx->parent_ctx) | |
1033 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1034 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1035 | put_task_struct(ctx->task); |
4af57ef2 | 1036 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1037 | } |
a63eaf34 PM |
1038 | } |
1039 | ||
f63a8daa PZ |
1040 | /* |
1041 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1042 | * perf_pmu_migrate_context() we need some magic. | |
1043 | * | |
1044 | * Those places that change perf_event::ctx will hold both | |
1045 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1046 | * | |
8b10c5e2 PZ |
1047 | * Lock ordering is by mutex address. There are two other sites where |
1048 | * perf_event_context::mutex nests and those are: | |
1049 | * | |
1050 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1051 | * perf_event_exit_event() |
1052 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1053 | * |
1054 | * - perf_event_init_context() [ parent, 0 ] | |
1055 | * inherit_task_group() | |
1056 | * inherit_group() | |
1057 | * inherit_event() | |
1058 | * perf_event_alloc() | |
1059 | * perf_init_event() | |
1060 | * perf_try_init_event() [ child , 1 ] | |
1061 | * | |
1062 | * While it appears there is an obvious deadlock here -- the parent and child | |
1063 | * nesting levels are inverted between the two. This is in fact safe because | |
1064 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1065 | * spawning task cannot (yet) exit. | |
1066 | * | |
1067 | * But remember that that these are parent<->child context relations, and | |
1068 | * migration does not affect children, therefore these two orderings should not | |
1069 | * interact. | |
f63a8daa PZ |
1070 | * |
1071 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1072 | * because the sys_perf_event_open() case will install a new event and break | |
1073 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1074 | * concerned with cpuctx and that doesn't have children. | |
1075 | * | |
1076 | * The places that change perf_event::ctx will issue: | |
1077 | * | |
1078 | * perf_remove_from_context(); | |
1079 | * synchronize_rcu(); | |
1080 | * perf_install_in_context(); | |
1081 | * | |
1082 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1083 | * quiesce the event, after which we can install it in the new location. This | |
1084 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1085 | * while in transit. Therefore all such accessors should also acquire | |
1086 | * perf_event_context::mutex to serialize against this. | |
1087 | * | |
1088 | * However; because event->ctx can change while we're waiting to acquire | |
1089 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1090 | * function. | |
1091 | * | |
1092 | * Lock order: | |
1093 | * task_struct::perf_event_mutex | |
1094 | * perf_event_context::mutex | |
f63a8daa | 1095 | * perf_event::child_mutex; |
07c4a776 | 1096 | * perf_event_context::lock |
f63a8daa PZ |
1097 | * perf_event::mmap_mutex |
1098 | * mmap_sem | |
1099 | */ | |
a83fe28e PZ |
1100 | static struct perf_event_context * |
1101 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1102 | { |
1103 | struct perf_event_context *ctx; | |
1104 | ||
1105 | again: | |
1106 | rcu_read_lock(); | |
1107 | ctx = ACCESS_ONCE(event->ctx); | |
1108 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1109 | rcu_read_unlock(); | |
1110 | goto again; | |
1111 | } | |
1112 | rcu_read_unlock(); | |
1113 | ||
a83fe28e | 1114 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1115 | if (event->ctx != ctx) { |
1116 | mutex_unlock(&ctx->mutex); | |
1117 | put_ctx(ctx); | |
1118 | goto again; | |
1119 | } | |
1120 | ||
1121 | return ctx; | |
1122 | } | |
1123 | ||
a83fe28e PZ |
1124 | static inline struct perf_event_context * |
1125 | perf_event_ctx_lock(struct perf_event *event) | |
1126 | { | |
1127 | return perf_event_ctx_lock_nested(event, 0); | |
1128 | } | |
1129 | ||
f63a8daa PZ |
1130 | static void perf_event_ctx_unlock(struct perf_event *event, |
1131 | struct perf_event_context *ctx) | |
1132 | { | |
1133 | mutex_unlock(&ctx->mutex); | |
1134 | put_ctx(ctx); | |
1135 | } | |
1136 | ||
211de6eb PZ |
1137 | /* |
1138 | * This must be done under the ctx->lock, such as to serialize against | |
1139 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1140 | * calling scheduler related locks and ctx->lock nests inside those. | |
1141 | */ | |
1142 | static __must_check struct perf_event_context * | |
1143 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1144 | { |
211de6eb PZ |
1145 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1146 | ||
1147 | lockdep_assert_held(&ctx->lock); | |
1148 | ||
1149 | if (parent_ctx) | |
71a851b4 | 1150 | ctx->parent_ctx = NULL; |
5a3126d4 | 1151 | ctx->generation++; |
211de6eb PZ |
1152 | |
1153 | return parent_ctx; | |
71a851b4 PZ |
1154 | } |
1155 | ||
6844c09d ACM |
1156 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1157 | { | |
1158 | /* | |
1159 | * only top level events have the pid namespace they were created in | |
1160 | */ | |
1161 | if (event->parent) | |
1162 | event = event->parent; | |
1163 | ||
1164 | return task_tgid_nr_ns(p, event->ns); | |
1165 | } | |
1166 | ||
1167 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1168 | { | |
1169 | /* | |
1170 | * only top level events have the pid namespace they were created in | |
1171 | */ | |
1172 | if (event->parent) | |
1173 | event = event->parent; | |
1174 | ||
1175 | return task_pid_nr_ns(p, event->ns); | |
1176 | } | |
1177 | ||
7f453c24 | 1178 | /* |
cdd6c482 | 1179 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1180 | * to userspace. |
1181 | */ | |
cdd6c482 | 1182 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1183 | { |
cdd6c482 | 1184 | u64 id = event->id; |
7f453c24 | 1185 | |
cdd6c482 IM |
1186 | if (event->parent) |
1187 | id = event->parent->id; | |
7f453c24 PZ |
1188 | |
1189 | return id; | |
1190 | } | |
1191 | ||
25346b93 | 1192 | /* |
cdd6c482 | 1193 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1194 | * |
25346b93 PM |
1195 | * This has to cope with with the fact that until it is locked, |
1196 | * the context could get moved to another task. | |
1197 | */ | |
cdd6c482 | 1198 | static struct perf_event_context * |
8dc85d54 | 1199 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1200 | { |
cdd6c482 | 1201 | struct perf_event_context *ctx; |
25346b93 | 1202 | |
9ed6060d | 1203 | retry: |
058ebd0e PZ |
1204 | /* |
1205 | * One of the few rules of preemptible RCU is that one cannot do | |
1206 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1207 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1208 | * rcu_read_unlock_special(). |
1209 | * | |
1210 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1211 | * side critical section has interrupts disabled. |
058ebd0e | 1212 | */ |
2fd59077 | 1213 | local_irq_save(*flags); |
058ebd0e | 1214 | rcu_read_lock(); |
8dc85d54 | 1215 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1216 | if (ctx) { |
1217 | /* | |
1218 | * If this context is a clone of another, it might | |
1219 | * get swapped for another underneath us by | |
cdd6c482 | 1220 | * perf_event_task_sched_out, though the |
25346b93 PM |
1221 | * rcu_read_lock() protects us from any context |
1222 | * getting freed. Lock the context and check if it | |
1223 | * got swapped before we could get the lock, and retry | |
1224 | * if so. If we locked the right context, then it | |
1225 | * can't get swapped on us any more. | |
1226 | */ | |
2fd59077 | 1227 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1228 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1229 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1230 | rcu_read_unlock(); |
2fd59077 | 1231 | local_irq_restore(*flags); |
25346b93 PM |
1232 | goto retry; |
1233 | } | |
b49a9e7e | 1234 | |
63b6da39 PZ |
1235 | if (ctx->task == TASK_TOMBSTONE || |
1236 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1237 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1238 | ctx = NULL; |
828b6f0e PZ |
1239 | } else { |
1240 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1241 | } |
25346b93 PM |
1242 | } |
1243 | rcu_read_unlock(); | |
2fd59077 PM |
1244 | if (!ctx) |
1245 | local_irq_restore(*flags); | |
25346b93 PM |
1246 | return ctx; |
1247 | } | |
1248 | ||
1249 | /* | |
1250 | * Get the context for a task and increment its pin_count so it | |
1251 | * can't get swapped to another task. This also increments its | |
1252 | * reference count so that the context can't get freed. | |
1253 | */ | |
8dc85d54 PZ |
1254 | static struct perf_event_context * |
1255 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1256 | { |
cdd6c482 | 1257 | struct perf_event_context *ctx; |
25346b93 PM |
1258 | unsigned long flags; |
1259 | ||
8dc85d54 | 1260 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1261 | if (ctx) { |
1262 | ++ctx->pin_count; | |
e625cce1 | 1263 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1264 | } |
1265 | return ctx; | |
1266 | } | |
1267 | ||
cdd6c482 | 1268 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1269 | { |
1270 | unsigned long flags; | |
1271 | ||
e625cce1 | 1272 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1273 | --ctx->pin_count; |
e625cce1 | 1274 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1275 | } |
1276 | ||
f67218c3 PZ |
1277 | /* |
1278 | * Update the record of the current time in a context. | |
1279 | */ | |
1280 | static void update_context_time(struct perf_event_context *ctx) | |
1281 | { | |
1282 | u64 now = perf_clock(); | |
1283 | ||
1284 | ctx->time += now - ctx->timestamp; | |
1285 | ctx->timestamp = now; | |
1286 | } | |
1287 | ||
4158755d SE |
1288 | static u64 perf_event_time(struct perf_event *event) |
1289 | { | |
1290 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1291 | |
1292 | if (is_cgroup_event(event)) | |
1293 | return perf_cgroup_event_time(event); | |
1294 | ||
4158755d SE |
1295 | return ctx ? ctx->time : 0; |
1296 | } | |
1297 | ||
f67218c3 PZ |
1298 | /* |
1299 | * Update the total_time_enabled and total_time_running fields for a event. | |
1300 | */ | |
1301 | static void update_event_times(struct perf_event *event) | |
1302 | { | |
1303 | struct perf_event_context *ctx = event->ctx; | |
1304 | u64 run_end; | |
1305 | ||
3cbaa590 PZ |
1306 | lockdep_assert_held(&ctx->lock); |
1307 | ||
f67218c3 PZ |
1308 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
1309 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1310 | return; | |
3cbaa590 | 1311 | |
e5d1367f SE |
1312 | /* |
1313 | * in cgroup mode, time_enabled represents | |
1314 | * the time the event was enabled AND active | |
1315 | * tasks were in the monitored cgroup. This is | |
1316 | * independent of the activity of the context as | |
1317 | * there may be a mix of cgroup and non-cgroup events. | |
1318 | * | |
1319 | * That is why we treat cgroup events differently | |
1320 | * here. | |
1321 | */ | |
1322 | if (is_cgroup_event(event)) | |
46cd6a7f | 1323 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1324 | else if (ctx->is_active) |
1325 | run_end = ctx->time; | |
acd1d7c1 PZ |
1326 | else |
1327 | run_end = event->tstamp_stopped; | |
1328 | ||
1329 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1330 | |
1331 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1332 | run_end = event->tstamp_stopped; | |
1333 | else | |
4158755d | 1334 | run_end = perf_event_time(event); |
f67218c3 PZ |
1335 | |
1336 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1337 | |
f67218c3 PZ |
1338 | } |
1339 | ||
96c21a46 PZ |
1340 | /* |
1341 | * Update total_time_enabled and total_time_running for all events in a group. | |
1342 | */ | |
1343 | static void update_group_times(struct perf_event *leader) | |
1344 | { | |
1345 | struct perf_event *event; | |
1346 | ||
1347 | update_event_times(leader); | |
1348 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1349 | update_event_times(event); | |
1350 | } | |
1351 | ||
889ff015 FW |
1352 | static struct list_head * |
1353 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1354 | { | |
1355 | if (event->attr.pinned) | |
1356 | return &ctx->pinned_groups; | |
1357 | else | |
1358 | return &ctx->flexible_groups; | |
1359 | } | |
1360 | ||
fccc714b | 1361 | /* |
cdd6c482 | 1362 | * Add a event from the lists for its context. |
fccc714b PZ |
1363 | * Must be called with ctx->mutex and ctx->lock held. |
1364 | */ | |
04289bb9 | 1365 | static void |
cdd6c482 | 1366 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1367 | { |
c994d613 PZ |
1368 | lockdep_assert_held(&ctx->lock); |
1369 | ||
8a49542c PZ |
1370 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1371 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1372 | |
1373 | /* | |
8a49542c PZ |
1374 | * If we're a stand alone event or group leader, we go to the context |
1375 | * list, group events are kept attached to the group so that | |
1376 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1377 | */ |
8a49542c | 1378 | if (event->group_leader == event) { |
889ff015 FW |
1379 | struct list_head *list; |
1380 | ||
d6f962b5 FW |
1381 | if (is_software_event(event)) |
1382 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1383 | ||
889ff015 FW |
1384 | list = ctx_group_list(event, ctx); |
1385 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1386 | } |
592903cd | 1387 | |
08309379 | 1388 | if (is_cgroup_event(event)) |
e5d1367f | 1389 | ctx->nr_cgroups++; |
e5d1367f | 1390 | |
cdd6c482 IM |
1391 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1392 | ctx->nr_events++; | |
1393 | if (event->attr.inherit_stat) | |
bfbd3381 | 1394 | ctx->nr_stat++; |
5a3126d4 PZ |
1395 | |
1396 | ctx->generation++; | |
04289bb9 IM |
1397 | } |
1398 | ||
0231bb53 JO |
1399 | /* |
1400 | * Initialize event state based on the perf_event_attr::disabled. | |
1401 | */ | |
1402 | static inline void perf_event__state_init(struct perf_event *event) | |
1403 | { | |
1404 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1405 | PERF_EVENT_STATE_INACTIVE; | |
1406 | } | |
1407 | ||
a723968c | 1408 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1409 | { |
1410 | int entry = sizeof(u64); /* value */ | |
1411 | int size = 0; | |
1412 | int nr = 1; | |
1413 | ||
1414 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1415 | size += sizeof(u64); | |
1416 | ||
1417 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1418 | size += sizeof(u64); | |
1419 | ||
1420 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1421 | entry += sizeof(u64); | |
1422 | ||
1423 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1424 | nr += nr_siblings; |
c320c7b7 ACM |
1425 | size += sizeof(u64); |
1426 | } | |
1427 | ||
1428 | size += entry * nr; | |
1429 | event->read_size = size; | |
1430 | } | |
1431 | ||
a723968c | 1432 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1433 | { |
1434 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1435 | u16 size = 0; |
1436 | ||
c320c7b7 ACM |
1437 | if (sample_type & PERF_SAMPLE_IP) |
1438 | size += sizeof(data->ip); | |
1439 | ||
6844c09d ACM |
1440 | if (sample_type & PERF_SAMPLE_ADDR) |
1441 | size += sizeof(data->addr); | |
1442 | ||
1443 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1444 | size += sizeof(data->period); | |
1445 | ||
c3feedf2 AK |
1446 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1447 | size += sizeof(data->weight); | |
1448 | ||
6844c09d ACM |
1449 | if (sample_type & PERF_SAMPLE_READ) |
1450 | size += event->read_size; | |
1451 | ||
d6be9ad6 SE |
1452 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1453 | size += sizeof(data->data_src.val); | |
1454 | ||
fdfbbd07 AK |
1455 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1456 | size += sizeof(data->txn); | |
1457 | ||
6844c09d ACM |
1458 | event->header_size = size; |
1459 | } | |
1460 | ||
a723968c PZ |
1461 | /* |
1462 | * Called at perf_event creation and when events are attached/detached from a | |
1463 | * group. | |
1464 | */ | |
1465 | static void perf_event__header_size(struct perf_event *event) | |
1466 | { | |
1467 | __perf_event_read_size(event, | |
1468 | event->group_leader->nr_siblings); | |
1469 | __perf_event_header_size(event, event->attr.sample_type); | |
1470 | } | |
1471 | ||
6844c09d ACM |
1472 | static void perf_event__id_header_size(struct perf_event *event) |
1473 | { | |
1474 | struct perf_sample_data *data; | |
1475 | u64 sample_type = event->attr.sample_type; | |
1476 | u16 size = 0; | |
1477 | ||
c320c7b7 ACM |
1478 | if (sample_type & PERF_SAMPLE_TID) |
1479 | size += sizeof(data->tid_entry); | |
1480 | ||
1481 | if (sample_type & PERF_SAMPLE_TIME) | |
1482 | size += sizeof(data->time); | |
1483 | ||
ff3d527c AH |
1484 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1485 | size += sizeof(data->id); | |
1486 | ||
c320c7b7 ACM |
1487 | if (sample_type & PERF_SAMPLE_ID) |
1488 | size += sizeof(data->id); | |
1489 | ||
1490 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1491 | size += sizeof(data->stream_id); | |
1492 | ||
1493 | if (sample_type & PERF_SAMPLE_CPU) | |
1494 | size += sizeof(data->cpu_entry); | |
1495 | ||
6844c09d | 1496 | event->id_header_size = size; |
c320c7b7 ACM |
1497 | } |
1498 | ||
a723968c PZ |
1499 | static bool perf_event_validate_size(struct perf_event *event) |
1500 | { | |
1501 | /* | |
1502 | * The values computed here will be over-written when we actually | |
1503 | * attach the event. | |
1504 | */ | |
1505 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1506 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1507 | perf_event__id_header_size(event); | |
1508 | ||
1509 | /* | |
1510 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1511 | * Conservative limit to allow for callchains and other variable fields. | |
1512 | */ | |
1513 | if (event->read_size + event->header_size + | |
1514 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1515 | return false; | |
1516 | ||
1517 | return true; | |
1518 | } | |
1519 | ||
8a49542c PZ |
1520 | static void perf_group_attach(struct perf_event *event) |
1521 | { | |
c320c7b7 | 1522 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1523 | |
74c3337c PZ |
1524 | /* |
1525 | * We can have double attach due to group movement in perf_event_open. | |
1526 | */ | |
1527 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1528 | return; | |
1529 | ||
8a49542c PZ |
1530 | event->attach_state |= PERF_ATTACH_GROUP; |
1531 | ||
1532 | if (group_leader == event) | |
1533 | return; | |
1534 | ||
652884fe PZ |
1535 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1536 | ||
8a49542c PZ |
1537 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1538 | !is_software_event(event)) | |
1539 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1540 | ||
1541 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1542 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1543 | |
1544 | perf_event__header_size(group_leader); | |
1545 | ||
1546 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1547 | perf_event__header_size(pos); | |
8a49542c PZ |
1548 | } |
1549 | ||
a63eaf34 | 1550 | /* |
cdd6c482 | 1551 | * Remove a event from the lists for its context. |
fccc714b | 1552 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1553 | */ |
04289bb9 | 1554 | static void |
cdd6c482 | 1555 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1556 | { |
68cacd29 | 1557 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1558 | |
1559 | WARN_ON_ONCE(event->ctx != ctx); | |
1560 | lockdep_assert_held(&ctx->lock); | |
1561 | ||
8a49542c PZ |
1562 | /* |
1563 | * We can have double detach due to exit/hot-unplug + close. | |
1564 | */ | |
1565 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1566 | return; |
8a49542c PZ |
1567 | |
1568 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1569 | ||
68cacd29 | 1570 | if (is_cgroup_event(event)) { |
e5d1367f | 1571 | ctx->nr_cgroups--; |
70a01657 PZ |
1572 | /* |
1573 | * Because cgroup events are always per-cpu events, this will | |
1574 | * always be called from the right CPU. | |
1575 | */ | |
68cacd29 SE |
1576 | cpuctx = __get_cpu_context(ctx); |
1577 | /* | |
70a01657 PZ |
1578 | * If there are no more cgroup events then clear cgrp to avoid |
1579 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1580 | */ |
1581 | if (!ctx->nr_cgroups) | |
1582 | cpuctx->cgrp = NULL; | |
1583 | } | |
e5d1367f | 1584 | |
cdd6c482 IM |
1585 | ctx->nr_events--; |
1586 | if (event->attr.inherit_stat) | |
bfbd3381 | 1587 | ctx->nr_stat--; |
8bc20959 | 1588 | |
cdd6c482 | 1589 | list_del_rcu(&event->event_entry); |
04289bb9 | 1590 | |
8a49542c PZ |
1591 | if (event->group_leader == event) |
1592 | list_del_init(&event->group_entry); | |
5c148194 | 1593 | |
96c21a46 | 1594 | update_group_times(event); |
b2e74a26 SE |
1595 | |
1596 | /* | |
1597 | * If event was in error state, then keep it | |
1598 | * that way, otherwise bogus counts will be | |
1599 | * returned on read(). The only way to get out | |
1600 | * of error state is by explicit re-enabling | |
1601 | * of the event | |
1602 | */ | |
1603 | if (event->state > PERF_EVENT_STATE_OFF) | |
1604 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1605 | |
1606 | ctx->generation++; | |
050735b0 PZ |
1607 | } |
1608 | ||
8a49542c | 1609 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1610 | { |
1611 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1612 | struct list_head *list = NULL; |
1613 | ||
1614 | /* | |
1615 | * We can have double detach due to exit/hot-unplug + close. | |
1616 | */ | |
1617 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1618 | return; | |
1619 | ||
1620 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1621 | ||
1622 | /* | |
1623 | * If this is a sibling, remove it from its group. | |
1624 | */ | |
1625 | if (event->group_leader != event) { | |
1626 | list_del_init(&event->group_entry); | |
1627 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1628 | goto out; |
8a49542c PZ |
1629 | } |
1630 | ||
1631 | if (!list_empty(&event->group_entry)) | |
1632 | list = &event->group_entry; | |
2e2af50b | 1633 | |
04289bb9 | 1634 | /* |
cdd6c482 IM |
1635 | * If this was a group event with sibling events then |
1636 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1637 | * to whatever list we are on. |
04289bb9 | 1638 | */ |
cdd6c482 | 1639 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1640 | if (list) |
1641 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1642 | sibling->group_leader = sibling; |
d6f962b5 FW |
1643 | |
1644 | /* Inherit group flags from the previous leader */ | |
1645 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1646 | |
1647 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1648 | } |
c320c7b7 ACM |
1649 | |
1650 | out: | |
1651 | perf_event__header_size(event->group_leader); | |
1652 | ||
1653 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1654 | perf_event__header_size(tmp); | |
04289bb9 IM |
1655 | } |
1656 | ||
fadfe7be JO |
1657 | static bool is_orphaned_event(struct perf_event *event) |
1658 | { | |
a69b0ca4 | 1659 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1660 | } |
1661 | ||
66eb579e MR |
1662 | static inline int pmu_filter_match(struct perf_event *event) |
1663 | { | |
1664 | struct pmu *pmu = event->pmu; | |
1665 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1666 | } | |
1667 | ||
fa66f07a SE |
1668 | static inline int |
1669 | event_filter_match(struct perf_event *event) | |
1670 | { | |
e5d1367f | 1671 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1672 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1673 | } |
1674 | ||
9ffcfa6f SE |
1675 | static void |
1676 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1677 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1678 | struct perf_event_context *ctx) |
3b6f9e5c | 1679 | { |
4158755d | 1680 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1681 | u64 delta; |
652884fe PZ |
1682 | |
1683 | WARN_ON_ONCE(event->ctx != ctx); | |
1684 | lockdep_assert_held(&ctx->lock); | |
1685 | ||
fa66f07a SE |
1686 | /* |
1687 | * An event which could not be activated because of | |
1688 | * filter mismatch still needs to have its timings | |
1689 | * maintained, otherwise bogus information is return | |
1690 | * via read() for time_enabled, time_running: | |
1691 | */ | |
1692 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1693 | && !event_filter_match(event)) { | |
e5d1367f | 1694 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1695 | event->tstamp_running += delta; |
4158755d | 1696 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1697 | } |
1698 | ||
cdd6c482 | 1699 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1700 | return; |
3b6f9e5c | 1701 | |
44377277 AS |
1702 | perf_pmu_disable(event->pmu); |
1703 | ||
28a967c3 PZ |
1704 | event->tstamp_stopped = tstamp; |
1705 | event->pmu->del(event, 0); | |
1706 | event->oncpu = -1; | |
cdd6c482 IM |
1707 | event->state = PERF_EVENT_STATE_INACTIVE; |
1708 | if (event->pending_disable) { | |
1709 | event->pending_disable = 0; | |
1710 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1711 | } |
3b6f9e5c | 1712 | |
cdd6c482 | 1713 | if (!is_software_event(event)) |
3b6f9e5c | 1714 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1715 | if (!--ctx->nr_active) |
1716 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1717 | if (event->attr.freq && event->attr.sample_freq) |
1718 | ctx->nr_freq--; | |
cdd6c482 | 1719 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1720 | cpuctx->exclusive = 0; |
44377277 AS |
1721 | |
1722 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1723 | } |
1724 | ||
d859e29f | 1725 | static void |
cdd6c482 | 1726 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1727 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1728 | struct perf_event_context *ctx) |
d859e29f | 1729 | { |
cdd6c482 | 1730 | struct perf_event *event; |
fa66f07a | 1731 | int state = group_event->state; |
d859e29f | 1732 | |
cdd6c482 | 1733 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1734 | |
1735 | /* | |
1736 | * Schedule out siblings (if any): | |
1737 | */ | |
cdd6c482 IM |
1738 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1739 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1740 | |
fa66f07a | 1741 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1742 | cpuctx->exclusive = 0; |
1743 | } | |
1744 | ||
45a0e07a | 1745 | #define DETACH_GROUP 0x01UL |
0017960f | 1746 | |
0793a61d | 1747 | /* |
cdd6c482 | 1748 | * Cross CPU call to remove a performance event |
0793a61d | 1749 | * |
cdd6c482 | 1750 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1751 | * remove it from the context list. |
1752 | */ | |
fae3fde6 PZ |
1753 | static void |
1754 | __perf_remove_from_context(struct perf_event *event, | |
1755 | struct perf_cpu_context *cpuctx, | |
1756 | struct perf_event_context *ctx, | |
1757 | void *info) | |
0793a61d | 1758 | { |
45a0e07a | 1759 | unsigned long flags = (unsigned long)info; |
0793a61d | 1760 | |
cdd6c482 | 1761 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1762 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1763 | perf_group_detach(event); |
cdd6c482 | 1764 | list_del_event(event, ctx); |
39a43640 PZ |
1765 | |
1766 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1767 | ctx->is_active = 0; |
39a43640 PZ |
1768 | if (ctx->task) { |
1769 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1770 | cpuctx->task_ctx = NULL; | |
1771 | } | |
64ce3126 | 1772 | } |
0793a61d TG |
1773 | } |
1774 | ||
0793a61d | 1775 | /* |
cdd6c482 | 1776 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1777 | * |
cdd6c482 IM |
1778 | * If event->ctx is a cloned context, callers must make sure that |
1779 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1780 | * remains valid. This is OK when called from perf_release since |
1781 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1782 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1783 | * context has been detached from its task. |
0793a61d | 1784 | */ |
45a0e07a | 1785 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1786 | { |
fae3fde6 | 1787 | lockdep_assert_held(&event->ctx->mutex); |
0793a61d | 1788 | |
45a0e07a | 1789 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
0793a61d TG |
1790 | } |
1791 | ||
d859e29f | 1792 | /* |
cdd6c482 | 1793 | * Cross CPU call to disable a performance event |
d859e29f | 1794 | */ |
fae3fde6 PZ |
1795 | static void __perf_event_disable(struct perf_event *event, |
1796 | struct perf_cpu_context *cpuctx, | |
1797 | struct perf_event_context *ctx, | |
1798 | void *info) | |
7b648018 | 1799 | { |
fae3fde6 PZ |
1800 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1801 | return; | |
7b648018 | 1802 | |
fae3fde6 PZ |
1803 | update_context_time(ctx); |
1804 | update_cgrp_time_from_event(event); | |
1805 | update_group_times(event); | |
1806 | if (event == event->group_leader) | |
1807 | group_sched_out(event, cpuctx, ctx); | |
1808 | else | |
1809 | event_sched_out(event, cpuctx, ctx); | |
1810 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1811 | } |
1812 | ||
d859e29f | 1813 | /* |
cdd6c482 | 1814 | * Disable a event. |
c93f7669 | 1815 | * |
cdd6c482 IM |
1816 | * If event->ctx is a cloned context, callers must make sure that |
1817 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1818 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1819 | * perf_event_for_each_child or perf_event_for_each because they |
1820 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1821 | * goes to exit will block in perf_event_exit_event(). |
1822 | * | |
cdd6c482 | 1823 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1824 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1825 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1826 | */ |
f63a8daa | 1827 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1828 | { |
cdd6c482 | 1829 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1830 | |
e625cce1 | 1831 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1832 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1833 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1834 | return; |
53cfbf59 | 1835 | } |
e625cce1 | 1836 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1837 | |
fae3fde6 PZ |
1838 | event_function_call(event, __perf_event_disable, NULL); |
1839 | } | |
1840 | ||
1841 | void perf_event_disable_local(struct perf_event *event) | |
1842 | { | |
1843 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1844 | } |
f63a8daa PZ |
1845 | |
1846 | /* | |
1847 | * Strictly speaking kernel users cannot create groups and therefore this | |
1848 | * interface does not need the perf_event_ctx_lock() magic. | |
1849 | */ | |
1850 | void perf_event_disable(struct perf_event *event) | |
1851 | { | |
1852 | struct perf_event_context *ctx; | |
1853 | ||
1854 | ctx = perf_event_ctx_lock(event); | |
1855 | _perf_event_disable(event); | |
1856 | perf_event_ctx_unlock(event, ctx); | |
1857 | } | |
dcfce4a0 | 1858 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1859 | |
e5d1367f SE |
1860 | static void perf_set_shadow_time(struct perf_event *event, |
1861 | struct perf_event_context *ctx, | |
1862 | u64 tstamp) | |
1863 | { | |
1864 | /* | |
1865 | * use the correct time source for the time snapshot | |
1866 | * | |
1867 | * We could get by without this by leveraging the | |
1868 | * fact that to get to this function, the caller | |
1869 | * has most likely already called update_context_time() | |
1870 | * and update_cgrp_time_xx() and thus both timestamp | |
1871 | * are identical (or very close). Given that tstamp is, | |
1872 | * already adjusted for cgroup, we could say that: | |
1873 | * tstamp - ctx->timestamp | |
1874 | * is equivalent to | |
1875 | * tstamp - cgrp->timestamp. | |
1876 | * | |
1877 | * Then, in perf_output_read(), the calculation would | |
1878 | * work with no changes because: | |
1879 | * - event is guaranteed scheduled in | |
1880 | * - no scheduled out in between | |
1881 | * - thus the timestamp would be the same | |
1882 | * | |
1883 | * But this is a bit hairy. | |
1884 | * | |
1885 | * So instead, we have an explicit cgroup call to remain | |
1886 | * within the time time source all along. We believe it | |
1887 | * is cleaner and simpler to understand. | |
1888 | */ | |
1889 | if (is_cgroup_event(event)) | |
1890 | perf_cgroup_set_shadow_time(event, tstamp); | |
1891 | else | |
1892 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1893 | } | |
1894 | ||
4fe757dd PZ |
1895 | #define MAX_INTERRUPTS (~0ULL) |
1896 | ||
1897 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1898 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1899 | |
235c7fc7 | 1900 | static int |
9ffcfa6f | 1901 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1902 | struct perf_cpu_context *cpuctx, |
6e37738a | 1903 | struct perf_event_context *ctx) |
235c7fc7 | 1904 | { |
4158755d | 1905 | u64 tstamp = perf_event_time(event); |
44377277 | 1906 | int ret = 0; |
4158755d | 1907 | |
63342411 PZ |
1908 | lockdep_assert_held(&ctx->lock); |
1909 | ||
cdd6c482 | 1910 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1911 | return 0; |
1912 | ||
cdd6c482 | 1913 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1914 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1915 | |
1916 | /* | |
1917 | * Unthrottle events, since we scheduled we might have missed several | |
1918 | * ticks already, also for a heavily scheduling task there is little | |
1919 | * guarantee it'll get a tick in a timely manner. | |
1920 | */ | |
1921 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1922 | perf_log_throttle(event, 1); | |
1923 | event->hw.interrupts = 0; | |
1924 | } | |
1925 | ||
235c7fc7 IM |
1926 | /* |
1927 | * The new state must be visible before we turn it on in the hardware: | |
1928 | */ | |
1929 | smp_wmb(); | |
1930 | ||
44377277 AS |
1931 | perf_pmu_disable(event->pmu); |
1932 | ||
72f669c0 SL |
1933 | perf_set_shadow_time(event, ctx, tstamp); |
1934 | ||
ec0d7729 AS |
1935 | perf_log_itrace_start(event); |
1936 | ||
a4eaf7f1 | 1937 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1938 | event->state = PERF_EVENT_STATE_INACTIVE; |
1939 | event->oncpu = -1; | |
44377277 AS |
1940 | ret = -EAGAIN; |
1941 | goto out; | |
235c7fc7 IM |
1942 | } |
1943 | ||
00a2916f PZ |
1944 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1945 | ||
cdd6c482 | 1946 | if (!is_software_event(event)) |
3b6f9e5c | 1947 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1948 | if (!ctx->nr_active++) |
1949 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1950 | if (event->attr.freq && event->attr.sample_freq) |
1951 | ctx->nr_freq++; | |
235c7fc7 | 1952 | |
cdd6c482 | 1953 | if (event->attr.exclusive) |
3b6f9e5c PM |
1954 | cpuctx->exclusive = 1; |
1955 | ||
44377277 AS |
1956 | out: |
1957 | perf_pmu_enable(event->pmu); | |
1958 | ||
1959 | return ret; | |
235c7fc7 IM |
1960 | } |
1961 | ||
6751b71e | 1962 | static int |
cdd6c482 | 1963 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1964 | struct perf_cpu_context *cpuctx, |
6e37738a | 1965 | struct perf_event_context *ctx) |
6751b71e | 1966 | { |
6bde9b6c | 1967 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1968 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1969 | u64 now = ctx->time; |
1970 | bool simulate = false; | |
6751b71e | 1971 | |
cdd6c482 | 1972 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1973 | return 0; |
1974 | ||
fbbe0701 | 1975 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1976 | |
9ffcfa6f | 1977 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1978 | pmu->cancel_txn(pmu); |
272325c4 | 1979 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1980 | return -EAGAIN; |
90151c35 | 1981 | } |
6751b71e PM |
1982 | |
1983 | /* | |
1984 | * Schedule in siblings as one group (if any): | |
1985 | */ | |
cdd6c482 | 1986 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1987 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1988 | partial_group = event; |
6751b71e PM |
1989 | goto group_error; |
1990 | } | |
1991 | } | |
1992 | ||
9ffcfa6f | 1993 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1994 | return 0; |
9ffcfa6f | 1995 | |
6751b71e PM |
1996 | group_error: |
1997 | /* | |
1998 | * Groups can be scheduled in as one unit only, so undo any | |
1999 | * partial group before returning: | |
d7842da4 SE |
2000 | * The events up to the failed event are scheduled out normally, |
2001 | * tstamp_stopped will be updated. | |
2002 | * | |
2003 | * The failed events and the remaining siblings need to have | |
2004 | * their timings updated as if they had gone thru event_sched_in() | |
2005 | * and event_sched_out(). This is required to get consistent timings | |
2006 | * across the group. This also takes care of the case where the group | |
2007 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2008 | * the time the event was actually stopped, such that time delta | |
2009 | * calculation in update_event_times() is correct. | |
6751b71e | 2010 | */ |
cdd6c482 IM |
2011 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2012 | if (event == partial_group) | |
d7842da4 SE |
2013 | simulate = true; |
2014 | ||
2015 | if (simulate) { | |
2016 | event->tstamp_running += now - event->tstamp_stopped; | |
2017 | event->tstamp_stopped = now; | |
2018 | } else { | |
2019 | event_sched_out(event, cpuctx, ctx); | |
2020 | } | |
6751b71e | 2021 | } |
9ffcfa6f | 2022 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2023 | |
ad5133b7 | 2024 | pmu->cancel_txn(pmu); |
90151c35 | 2025 | |
272325c4 | 2026 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2027 | |
6751b71e PM |
2028 | return -EAGAIN; |
2029 | } | |
2030 | ||
3b6f9e5c | 2031 | /* |
cdd6c482 | 2032 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2033 | */ |
cdd6c482 | 2034 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2035 | struct perf_cpu_context *cpuctx, |
2036 | int can_add_hw) | |
2037 | { | |
2038 | /* | |
cdd6c482 | 2039 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2040 | */ |
d6f962b5 | 2041 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2042 | return 1; |
2043 | /* | |
2044 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2045 | * events can go on. |
3b6f9e5c PM |
2046 | */ |
2047 | if (cpuctx->exclusive) | |
2048 | return 0; | |
2049 | /* | |
2050 | * If this group is exclusive and there are already | |
cdd6c482 | 2051 | * events on the CPU, it can't go on. |
3b6f9e5c | 2052 | */ |
cdd6c482 | 2053 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2054 | return 0; |
2055 | /* | |
2056 | * Otherwise, try to add it if all previous groups were able | |
2057 | * to go on. | |
2058 | */ | |
2059 | return can_add_hw; | |
2060 | } | |
2061 | ||
cdd6c482 IM |
2062 | static void add_event_to_ctx(struct perf_event *event, |
2063 | struct perf_event_context *ctx) | |
53cfbf59 | 2064 | { |
4158755d SE |
2065 | u64 tstamp = perf_event_time(event); |
2066 | ||
cdd6c482 | 2067 | list_add_event(event, ctx); |
8a49542c | 2068 | perf_group_attach(event); |
4158755d SE |
2069 | event->tstamp_enabled = tstamp; |
2070 | event->tstamp_running = tstamp; | |
2071 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2072 | } |
2073 | ||
bd2afa49 PZ |
2074 | static void ctx_sched_out(struct perf_event_context *ctx, |
2075 | struct perf_cpu_context *cpuctx, | |
2076 | enum event_type_t event_type); | |
2c29ef0f PZ |
2077 | static void |
2078 | ctx_sched_in(struct perf_event_context *ctx, | |
2079 | struct perf_cpu_context *cpuctx, | |
2080 | enum event_type_t event_type, | |
2081 | struct task_struct *task); | |
fe4b04fa | 2082 | |
bd2afa49 PZ |
2083 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2084 | struct perf_event_context *ctx) | |
2085 | { | |
2086 | if (!cpuctx->task_ctx) | |
2087 | return; | |
2088 | ||
2089 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2090 | return; | |
2091 | ||
2092 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); | |
2093 | } | |
2094 | ||
dce5855b PZ |
2095 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2096 | struct perf_event_context *ctx, | |
2097 | struct task_struct *task) | |
2098 | { | |
2099 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2100 | if (ctx) | |
2101 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2102 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2103 | if (ctx) | |
2104 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2105 | } | |
2106 | ||
3e349507 PZ |
2107 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2108 | struct perf_event_context *task_ctx) | |
0017960f | 2109 | { |
3e349507 PZ |
2110 | perf_pmu_disable(cpuctx->ctx.pmu); |
2111 | if (task_ctx) | |
2112 | task_ctx_sched_out(cpuctx, task_ctx); | |
2113 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2114 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2115 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2116 | } |
2117 | ||
0793a61d | 2118 | /* |
cdd6c482 | 2119 | * Cross CPU call to install and enable a performance event |
682076ae | 2120 | * |
a096309b PZ |
2121 | * Very similar to remote_function() + event_function() but cannot assume that |
2122 | * things like ctx->is_active and cpuctx->task_ctx are set. | |
0793a61d | 2123 | */ |
fe4b04fa | 2124 | static int __perf_install_in_context(void *info) |
0793a61d | 2125 | { |
a096309b PZ |
2126 | struct perf_event *event = info; |
2127 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2128 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2129 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
a096309b PZ |
2130 | bool activate = true; |
2131 | int ret = 0; | |
0793a61d | 2132 | |
63b6da39 | 2133 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2134 | if (ctx->task) { |
b58f6b0d PZ |
2135 | raw_spin_lock(&ctx->lock); |
2136 | task_ctx = ctx; | |
a096309b PZ |
2137 | |
2138 | /* If we're on the wrong CPU, try again */ | |
2139 | if (task_cpu(ctx->task) != smp_processor_id()) { | |
2140 | ret = -ESRCH; | |
63b6da39 | 2141 | goto unlock; |
a096309b | 2142 | } |
b58f6b0d | 2143 | |
39a43640 | 2144 | /* |
a096309b PZ |
2145 | * If we're on the right CPU, see if the task we target is |
2146 | * current, if not we don't have to activate the ctx, a future | |
2147 | * context switch will do that for us. | |
39a43640 | 2148 | */ |
a096309b PZ |
2149 | if (ctx->task != current) |
2150 | activate = false; | |
2151 | else | |
2152 | WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx); | |
2153 | ||
63b6da39 PZ |
2154 | } else if (task_ctx) { |
2155 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2156 | } |
b58f6b0d | 2157 | |
a096309b PZ |
2158 | if (activate) { |
2159 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2160 | add_event_to_ctx(event, ctx); | |
2161 | ctx_resched(cpuctx, task_ctx); | |
2162 | } else { | |
2163 | add_event_to_ctx(event, ctx); | |
2164 | } | |
2165 | ||
63b6da39 | 2166 | unlock: |
2c29ef0f | 2167 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa | 2168 | |
a096309b | 2169 | return ret; |
0793a61d TG |
2170 | } |
2171 | ||
2172 | /* | |
a096309b PZ |
2173 | * Attach a performance event to a context. |
2174 | * | |
2175 | * Very similar to event_function_call, see comment there. | |
0793a61d TG |
2176 | */ |
2177 | static void | |
cdd6c482 IM |
2178 | perf_install_in_context(struct perf_event_context *ctx, |
2179 | struct perf_event *event, | |
0793a61d TG |
2180 | int cpu) |
2181 | { | |
a096309b | 2182 | struct task_struct *task = READ_ONCE(ctx->task); |
39a43640 | 2183 | |
fe4b04fa PZ |
2184 | lockdep_assert_held(&ctx->mutex); |
2185 | ||
c3f00c70 | 2186 | event->ctx = ctx; |
0cda4c02 YZ |
2187 | if (event->cpu != -1) |
2188 | event->cpu = cpu; | |
c3f00c70 | 2189 | |
a096309b PZ |
2190 | if (!task) { |
2191 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2192 | return; | |
2193 | } | |
2194 | ||
2195 | /* | |
2196 | * Should not happen, we validate the ctx is still alive before calling. | |
2197 | */ | |
2198 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) | |
2199 | return; | |
2200 | ||
39a43640 PZ |
2201 | /* |
2202 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2203 | * to be set in case this is the nr_events 0 -> 1 transition. | |
39a43640 | 2204 | */ |
a096309b | 2205 | again: |
63b6da39 | 2206 | /* |
a096309b PZ |
2207 | * Cannot use task_function_call() because we need to run on the task's |
2208 | * CPU regardless of whether its current or not. | |
63b6da39 | 2209 | */ |
a096309b PZ |
2210 | if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event)) |
2211 | return; | |
2212 | ||
2213 | raw_spin_lock_irq(&ctx->lock); | |
2214 | task = ctx->task; | |
84c4e620 | 2215 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
a096309b PZ |
2216 | /* |
2217 | * Cannot happen because we already checked above (which also | |
2218 | * cannot happen), and we hold ctx->mutex, which serializes us | |
2219 | * against perf_event_exit_task_context(). | |
2220 | */ | |
63b6da39 PZ |
2221 | raw_spin_unlock_irq(&ctx->lock); |
2222 | return; | |
2223 | } | |
39a43640 | 2224 | raw_spin_unlock_irq(&ctx->lock); |
39a43640 | 2225 | /* |
a096309b PZ |
2226 | * Since !ctx->is_active doesn't mean anything, we must IPI |
2227 | * unconditionally. | |
39a43640 | 2228 | */ |
a096309b | 2229 | goto again; |
0793a61d TG |
2230 | } |
2231 | ||
fa289bec | 2232 | /* |
cdd6c482 | 2233 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2234 | * Enabling the leader of a group effectively enables all |
2235 | * the group members that aren't explicitly disabled, so we | |
2236 | * have to update their ->tstamp_enabled also. | |
2237 | * Note: this works for group members as well as group leaders | |
2238 | * since the non-leader members' sibling_lists will be empty. | |
2239 | */ | |
1d9b482e | 2240 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2241 | { |
cdd6c482 | 2242 | struct perf_event *sub; |
4158755d | 2243 | u64 tstamp = perf_event_time(event); |
fa289bec | 2244 | |
cdd6c482 | 2245 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2246 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2247 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2248 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2249 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2250 | } |
fa289bec PM |
2251 | } |
2252 | ||
d859e29f | 2253 | /* |
cdd6c482 | 2254 | * Cross CPU call to enable a performance event |
d859e29f | 2255 | */ |
fae3fde6 PZ |
2256 | static void __perf_event_enable(struct perf_event *event, |
2257 | struct perf_cpu_context *cpuctx, | |
2258 | struct perf_event_context *ctx, | |
2259 | void *info) | |
04289bb9 | 2260 | { |
cdd6c482 | 2261 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2262 | struct perf_event_context *task_ctx; |
04289bb9 | 2263 | |
6e801e01 PZ |
2264 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2265 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2266 | return; |
3cbed429 | 2267 | |
bd2afa49 PZ |
2268 | if (ctx->is_active) |
2269 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2270 | ||
1d9b482e | 2271 | __perf_event_mark_enabled(event); |
04289bb9 | 2272 | |
fae3fde6 PZ |
2273 | if (!ctx->is_active) |
2274 | return; | |
2275 | ||
e5d1367f | 2276 | if (!event_filter_match(event)) { |
bd2afa49 | 2277 | if (is_cgroup_event(event)) |
e5d1367f | 2278 | perf_cgroup_defer_enabled(event); |
bd2afa49 | 2279 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); |
fae3fde6 | 2280 | return; |
e5d1367f | 2281 | } |
f4c4176f | 2282 | |
04289bb9 | 2283 | /* |
cdd6c482 | 2284 | * If the event is in a group and isn't the group leader, |
d859e29f | 2285 | * then don't put it on unless the group is on. |
04289bb9 | 2286 | */ |
bd2afa49 PZ |
2287 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) { |
2288 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
fae3fde6 | 2289 | return; |
bd2afa49 | 2290 | } |
fe4b04fa | 2291 | |
fae3fde6 PZ |
2292 | task_ctx = cpuctx->task_ctx; |
2293 | if (ctx->task) | |
2294 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2295 | |
fae3fde6 | 2296 | ctx_resched(cpuctx, task_ctx); |
7b648018 PZ |
2297 | } |
2298 | ||
d859e29f | 2299 | /* |
cdd6c482 | 2300 | * Enable a event. |
c93f7669 | 2301 | * |
cdd6c482 IM |
2302 | * If event->ctx is a cloned context, callers must make sure that |
2303 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2304 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2305 | * perf_event_for_each_child or perf_event_for_each as described |
2306 | * for perf_event_disable. | |
d859e29f | 2307 | */ |
f63a8daa | 2308 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2309 | { |
cdd6c482 | 2310 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2311 | |
7b648018 | 2312 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2313 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2314 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2315 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2316 | return; |
2317 | } | |
2318 | ||
d859e29f | 2319 | /* |
cdd6c482 | 2320 | * If the event is in error state, clear that first. |
7b648018 PZ |
2321 | * |
2322 | * That way, if we see the event in error state below, we know that it | |
2323 | * has gone back into error state, as distinct from the task having | |
2324 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2325 | */ |
cdd6c482 IM |
2326 | if (event->state == PERF_EVENT_STATE_ERROR) |
2327 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2328 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2329 | |
fae3fde6 | 2330 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2331 | } |
f63a8daa PZ |
2332 | |
2333 | /* | |
2334 | * See perf_event_disable(); | |
2335 | */ | |
2336 | void perf_event_enable(struct perf_event *event) | |
2337 | { | |
2338 | struct perf_event_context *ctx; | |
2339 | ||
2340 | ctx = perf_event_ctx_lock(event); | |
2341 | _perf_event_enable(event); | |
2342 | perf_event_ctx_unlock(event, ctx); | |
2343 | } | |
dcfce4a0 | 2344 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2345 | |
f63a8daa | 2346 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2347 | { |
2023b359 | 2348 | /* |
cdd6c482 | 2349 | * not supported on inherited events |
2023b359 | 2350 | */ |
2e939d1d | 2351 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2352 | return -EINVAL; |
2353 | ||
cdd6c482 | 2354 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2355 | _perf_event_enable(event); |
2023b359 PZ |
2356 | |
2357 | return 0; | |
79f14641 | 2358 | } |
f63a8daa PZ |
2359 | |
2360 | /* | |
2361 | * See perf_event_disable() | |
2362 | */ | |
2363 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2364 | { | |
2365 | struct perf_event_context *ctx; | |
2366 | int ret; | |
2367 | ||
2368 | ctx = perf_event_ctx_lock(event); | |
2369 | ret = _perf_event_refresh(event, refresh); | |
2370 | perf_event_ctx_unlock(event, ctx); | |
2371 | ||
2372 | return ret; | |
2373 | } | |
26ca5c11 | 2374 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2375 | |
5b0311e1 FW |
2376 | static void ctx_sched_out(struct perf_event_context *ctx, |
2377 | struct perf_cpu_context *cpuctx, | |
2378 | enum event_type_t event_type) | |
235c7fc7 | 2379 | { |
db24d33e | 2380 | int is_active = ctx->is_active; |
c994d613 | 2381 | struct perf_event *event; |
235c7fc7 | 2382 | |
c994d613 | 2383 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2384 | |
39a43640 PZ |
2385 | if (likely(!ctx->nr_events)) { |
2386 | /* | |
2387 | * See __perf_remove_from_context(). | |
2388 | */ | |
2389 | WARN_ON_ONCE(ctx->is_active); | |
2390 | if (ctx->task) | |
2391 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2392 | return; |
39a43640 PZ |
2393 | } |
2394 | ||
db24d33e | 2395 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2396 | if (!(ctx->is_active & EVENT_ALL)) |
2397 | ctx->is_active = 0; | |
2398 | ||
63e30d3e PZ |
2399 | if (ctx->task) { |
2400 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2401 | if (!ctx->is_active) | |
2402 | cpuctx->task_ctx = NULL; | |
2403 | } | |
facc4307 | 2404 | |
3cbaa590 PZ |
2405 | is_active ^= ctx->is_active; /* changed bits */ |
2406 | ||
2407 | if (is_active & EVENT_TIME) { | |
2408 | /* update (and stop) ctx time */ | |
2409 | update_context_time(ctx); | |
2410 | update_cgrp_time_from_cpuctx(cpuctx); | |
2411 | } | |
2412 | ||
2413 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) | |
facc4307 | 2414 | return; |
5b0311e1 | 2415 | |
075e0b00 | 2416 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2417 | if (is_active & EVENT_PINNED) { |
889ff015 FW |
2418 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2419 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2420 | } |
889ff015 | 2421 | |
3cbaa590 | 2422 | if (is_active & EVENT_FLEXIBLE) { |
889ff015 | 2423 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2424 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2425 | } |
1b9a644f | 2426 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2427 | } |
2428 | ||
564c2b21 | 2429 | /* |
5a3126d4 PZ |
2430 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2431 | * cloned from the same version of the same context. | |
2432 | * | |
2433 | * Equivalence is measured using a generation number in the context that is | |
2434 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2435 | * and list_del_event(). | |
564c2b21 | 2436 | */ |
cdd6c482 IM |
2437 | static int context_equiv(struct perf_event_context *ctx1, |
2438 | struct perf_event_context *ctx2) | |
564c2b21 | 2439 | { |
211de6eb PZ |
2440 | lockdep_assert_held(&ctx1->lock); |
2441 | lockdep_assert_held(&ctx2->lock); | |
2442 | ||
5a3126d4 PZ |
2443 | /* Pinning disables the swap optimization */ |
2444 | if (ctx1->pin_count || ctx2->pin_count) | |
2445 | return 0; | |
2446 | ||
2447 | /* If ctx1 is the parent of ctx2 */ | |
2448 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2449 | return 1; | |
2450 | ||
2451 | /* If ctx2 is the parent of ctx1 */ | |
2452 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2453 | return 1; | |
2454 | ||
2455 | /* | |
2456 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2457 | * hierarchy, see perf_event_init_context(). | |
2458 | */ | |
2459 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2460 | ctx1->parent_gen == ctx2->parent_gen) | |
2461 | return 1; | |
2462 | ||
2463 | /* Unmatched */ | |
2464 | return 0; | |
564c2b21 PM |
2465 | } |
2466 | ||
cdd6c482 IM |
2467 | static void __perf_event_sync_stat(struct perf_event *event, |
2468 | struct perf_event *next_event) | |
bfbd3381 PZ |
2469 | { |
2470 | u64 value; | |
2471 | ||
cdd6c482 | 2472 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2473 | return; |
2474 | ||
2475 | /* | |
cdd6c482 | 2476 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2477 | * because we're in the middle of a context switch and have IRQs |
2478 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2479 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2480 | * don't need to use it. |
2481 | */ | |
cdd6c482 IM |
2482 | switch (event->state) { |
2483 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2484 | event->pmu->read(event); |
2485 | /* fall-through */ | |
bfbd3381 | 2486 | |
cdd6c482 IM |
2487 | case PERF_EVENT_STATE_INACTIVE: |
2488 | update_event_times(event); | |
bfbd3381 PZ |
2489 | break; |
2490 | ||
2491 | default: | |
2492 | break; | |
2493 | } | |
2494 | ||
2495 | /* | |
cdd6c482 | 2496 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2497 | * values when we flip the contexts. |
2498 | */ | |
e7850595 PZ |
2499 | value = local64_read(&next_event->count); |
2500 | value = local64_xchg(&event->count, value); | |
2501 | local64_set(&next_event->count, value); | |
bfbd3381 | 2502 | |
cdd6c482 IM |
2503 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2504 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2505 | |
bfbd3381 | 2506 | /* |
19d2e755 | 2507 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2508 | */ |
cdd6c482 IM |
2509 | perf_event_update_userpage(event); |
2510 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2511 | } |
2512 | ||
cdd6c482 IM |
2513 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2514 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2515 | { |
cdd6c482 | 2516 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2517 | |
2518 | if (!ctx->nr_stat) | |
2519 | return; | |
2520 | ||
02ffdbc8 PZ |
2521 | update_context_time(ctx); |
2522 | ||
cdd6c482 IM |
2523 | event = list_first_entry(&ctx->event_list, |
2524 | struct perf_event, event_entry); | |
bfbd3381 | 2525 | |
cdd6c482 IM |
2526 | next_event = list_first_entry(&next_ctx->event_list, |
2527 | struct perf_event, event_entry); | |
bfbd3381 | 2528 | |
cdd6c482 IM |
2529 | while (&event->event_entry != &ctx->event_list && |
2530 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2531 | |
cdd6c482 | 2532 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2533 | |
cdd6c482 IM |
2534 | event = list_next_entry(event, event_entry); |
2535 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2536 | } |
2537 | } | |
2538 | ||
fe4b04fa PZ |
2539 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2540 | struct task_struct *next) | |
0793a61d | 2541 | { |
8dc85d54 | 2542 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2543 | struct perf_event_context *next_ctx; |
5a3126d4 | 2544 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2545 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2546 | int do_switch = 1; |
0793a61d | 2547 | |
108b02cf PZ |
2548 | if (likely(!ctx)) |
2549 | return; | |
10989fb2 | 2550 | |
108b02cf PZ |
2551 | cpuctx = __get_cpu_context(ctx); |
2552 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2553 | return; |
2554 | ||
c93f7669 | 2555 | rcu_read_lock(); |
8dc85d54 | 2556 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2557 | if (!next_ctx) |
2558 | goto unlock; | |
2559 | ||
2560 | parent = rcu_dereference(ctx->parent_ctx); | |
2561 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2562 | ||
2563 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2564 | if (!parent && !next_parent) |
5a3126d4 PZ |
2565 | goto unlock; |
2566 | ||
2567 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2568 | /* |
2569 | * Looks like the two contexts are clones, so we might be | |
2570 | * able to optimize the context switch. We lock both | |
2571 | * contexts and check that they are clones under the | |
2572 | * lock (including re-checking that neither has been | |
2573 | * uncloned in the meantime). It doesn't matter which | |
2574 | * order we take the locks because no other cpu could | |
2575 | * be trying to lock both of these tasks. | |
2576 | */ | |
e625cce1 TG |
2577 | raw_spin_lock(&ctx->lock); |
2578 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2579 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2580 | WRITE_ONCE(ctx->task, next); |
2581 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2582 | |
2583 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2584 | ||
63b6da39 PZ |
2585 | /* |
2586 | * RCU_INIT_POINTER here is safe because we've not | |
2587 | * modified the ctx and the above modification of | |
2588 | * ctx->task and ctx->task_ctx_data are immaterial | |
2589 | * since those values are always verified under | |
2590 | * ctx->lock which we're now holding. | |
2591 | */ | |
2592 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2593 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2594 | ||
c93f7669 | 2595 | do_switch = 0; |
bfbd3381 | 2596 | |
cdd6c482 | 2597 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2598 | } |
e625cce1 TG |
2599 | raw_spin_unlock(&next_ctx->lock); |
2600 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2601 | } |
5a3126d4 | 2602 | unlock: |
c93f7669 | 2603 | rcu_read_unlock(); |
564c2b21 | 2604 | |
c93f7669 | 2605 | if (do_switch) { |
facc4307 | 2606 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2607 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2608 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2609 | } |
0793a61d TG |
2610 | } |
2611 | ||
ba532500 YZ |
2612 | void perf_sched_cb_dec(struct pmu *pmu) |
2613 | { | |
2614 | this_cpu_dec(perf_sched_cb_usages); | |
2615 | } | |
2616 | ||
2617 | void perf_sched_cb_inc(struct pmu *pmu) | |
2618 | { | |
2619 | this_cpu_inc(perf_sched_cb_usages); | |
2620 | } | |
2621 | ||
2622 | /* | |
2623 | * This function provides the context switch callback to the lower code | |
2624 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2625 | */ | |
2626 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2627 | struct task_struct *next, | |
2628 | bool sched_in) | |
2629 | { | |
2630 | struct perf_cpu_context *cpuctx; | |
2631 | struct pmu *pmu; | |
2632 | unsigned long flags; | |
2633 | ||
2634 | if (prev == next) | |
2635 | return; | |
2636 | ||
2637 | local_irq_save(flags); | |
2638 | ||
2639 | rcu_read_lock(); | |
2640 | ||
2641 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2642 | if (pmu->sched_task) { | |
2643 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2644 | ||
2645 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2646 | ||
2647 | perf_pmu_disable(pmu); | |
2648 | ||
2649 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2650 | ||
2651 | perf_pmu_enable(pmu); | |
2652 | ||
2653 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2654 | } | |
2655 | } | |
2656 | ||
2657 | rcu_read_unlock(); | |
2658 | ||
2659 | local_irq_restore(flags); | |
2660 | } | |
2661 | ||
45ac1403 AH |
2662 | static void perf_event_switch(struct task_struct *task, |
2663 | struct task_struct *next_prev, bool sched_in); | |
2664 | ||
8dc85d54 PZ |
2665 | #define for_each_task_context_nr(ctxn) \ |
2666 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2667 | ||
2668 | /* | |
2669 | * Called from scheduler to remove the events of the current task, | |
2670 | * with interrupts disabled. | |
2671 | * | |
2672 | * We stop each event and update the event value in event->count. | |
2673 | * | |
2674 | * This does not protect us against NMI, but disable() | |
2675 | * sets the disabled bit in the control field of event _before_ | |
2676 | * accessing the event control register. If a NMI hits, then it will | |
2677 | * not restart the event. | |
2678 | */ | |
ab0cce56 JO |
2679 | void __perf_event_task_sched_out(struct task_struct *task, |
2680 | struct task_struct *next) | |
8dc85d54 PZ |
2681 | { |
2682 | int ctxn; | |
2683 | ||
ba532500 YZ |
2684 | if (__this_cpu_read(perf_sched_cb_usages)) |
2685 | perf_pmu_sched_task(task, next, false); | |
2686 | ||
45ac1403 AH |
2687 | if (atomic_read(&nr_switch_events)) |
2688 | perf_event_switch(task, next, false); | |
2689 | ||
8dc85d54 PZ |
2690 | for_each_task_context_nr(ctxn) |
2691 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2692 | |
2693 | /* | |
2694 | * if cgroup events exist on this CPU, then we need | |
2695 | * to check if we have to switch out PMU state. | |
2696 | * cgroup event are system-wide mode only | |
2697 | */ | |
4a32fea9 | 2698 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2699 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2700 | } |
2701 | ||
5b0311e1 FW |
2702 | /* |
2703 | * Called with IRQs disabled | |
2704 | */ | |
2705 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2706 | enum event_type_t event_type) | |
2707 | { | |
2708 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2709 | } |
2710 | ||
235c7fc7 | 2711 | static void |
5b0311e1 | 2712 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2713 | struct perf_cpu_context *cpuctx) |
0793a61d | 2714 | { |
cdd6c482 | 2715 | struct perf_event *event; |
0793a61d | 2716 | |
889ff015 FW |
2717 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2718 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2719 | continue; |
5632ab12 | 2720 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2721 | continue; |
2722 | ||
e5d1367f SE |
2723 | /* may need to reset tstamp_enabled */ |
2724 | if (is_cgroup_event(event)) | |
2725 | perf_cgroup_mark_enabled(event, ctx); | |
2726 | ||
8c9ed8e1 | 2727 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2728 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2729 | |
2730 | /* | |
2731 | * If this pinned group hasn't been scheduled, | |
2732 | * put it in error state. | |
2733 | */ | |
cdd6c482 IM |
2734 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2735 | update_group_times(event); | |
2736 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2737 | } |
3b6f9e5c | 2738 | } |
5b0311e1 FW |
2739 | } |
2740 | ||
2741 | static void | |
2742 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2743 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2744 | { |
2745 | struct perf_event *event; | |
2746 | int can_add_hw = 1; | |
3b6f9e5c | 2747 | |
889ff015 FW |
2748 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2749 | /* Ignore events in OFF or ERROR state */ | |
2750 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2751 | continue; |
04289bb9 IM |
2752 | /* |
2753 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2754 | * of events: |
04289bb9 | 2755 | */ |
5632ab12 | 2756 | if (!event_filter_match(event)) |
0793a61d TG |
2757 | continue; |
2758 | ||
e5d1367f SE |
2759 | /* may need to reset tstamp_enabled */ |
2760 | if (is_cgroup_event(event)) | |
2761 | perf_cgroup_mark_enabled(event, ctx); | |
2762 | ||
9ed6060d | 2763 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2764 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2765 | can_add_hw = 0; |
9ed6060d | 2766 | } |
0793a61d | 2767 | } |
5b0311e1 FW |
2768 | } |
2769 | ||
2770 | static void | |
2771 | ctx_sched_in(struct perf_event_context *ctx, | |
2772 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2773 | enum event_type_t event_type, |
2774 | struct task_struct *task) | |
5b0311e1 | 2775 | { |
db24d33e | 2776 | int is_active = ctx->is_active; |
c994d613 PZ |
2777 | u64 now; |
2778 | ||
2779 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2780 | |
5b0311e1 | 2781 | if (likely(!ctx->nr_events)) |
facc4307 | 2782 | return; |
5b0311e1 | 2783 | |
3cbaa590 | 2784 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
2785 | if (ctx->task) { |
2786 | if (!is_active) | |
2787 | cpuctx->task_ctx = ctx; | |
2788 | else | |
2789 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2790 | } | |
2791 | ||
3cbaa590 PZ |
2792 | is_active ^= ctx->is_active; /* changed bits */ |
2793 | ||
2794 | if (is_active & EVENT_TIME) { | |
2795 | /* start ctx time */ | |
2796 | now = perf_clock(); | |
2797 | ctx->timestamp = now; | |
2798 | perf_cgroup_set_timestamp(task, ctx); | |
2799 | } | |
2800 | ||
5b0311e1 FW |
2801 | /* |
2802 | * First go through the list and put on any pinned groups | |
2803 | * in order to give them the best chance of going on. | |
2804 | */ | |
3cbaa590 | 2805 | if (is_active & EVENT_PINNED) |
6e37738a | 2806 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2807 | |
2808 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 2809 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 2810 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2811 | } |
2812 | ||
329c0e01 | 2813 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2814 | enum event_type_t event_type, |
2815 | struct task_struct *task) | |
329c0e01 FW |
2816 | { |
2817 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2818 | ||
e5d1367f | 2819 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2820 | } |
2821 | ||
e5d1367f SE |
2822 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2823 | struct task_struct *task) | |
235c7fc7 | 2824 | { |
108b02cf | 2825 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2826 | |
108b02cf | 2827 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2828 | if (cpuctx->task_ctx == ctx) |
2829 | return; | |
2830 | ||
facc4307 | 2831 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2832 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2833 | /* |
2834 | * We want to keep the following priority order: | |
2835 | * cpu pinned (that don't need to move), task pinned, | |
2836 | * cpu flexible, task flexible. | |
2837 | */ | |
2838 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2839 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2840 | perf_pmu_enable(ctx->pmu); |
2841 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2842 | } |
2843 | ||
8dc85d54 PZ |
2844 | /* |
2845 | * Called from scheduler to add the events of the current task | |
2846 | * with interrupts disabled. | |
2847 | * | |
2848 | * We restore the event value and then enable it. | |
2849 | * | |
2850 | * This does not protect us against NMI, but enable() | |
2851 | * sets the enabled bit in the control field of event _before_ | |
2852 | * accessing the event control register. If a NMI hits, then it will | |
2853 | * keep the event running. | |
2854 | */ | |
ab0cce56 JO |
2855 | void __perf_event_task_sched_in(struct task_struct *prev, |
2856 | struct task_struct *task) | |
8dc85d54 PZ |
2857 | { |
2858 | struct perf_event_context *ctx; | |
2859 | int ctxn; | |
2860 | ||
7e41d177 PZ |
2861 | /* |
2862 | * If cgroup events exist on this CPU, then we need to check if we have | |
2863 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2864 | * | |
2865 | * Since cgroup events are CPU events, we must schedule these in before | |
2866 | * we schedule in the task events. | |
2867 | */ | |
2868 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2869 | perf_cgroup_sched_in(prev, task); | |
2870 | ||
8dc85d54 PZ |
2871 | for_each_task_context_nr(ctxn) { |
2872 | ctx = task->perf_event_ctxp[ctxn]; | |
2873 | if (likely(!ctx)) | |
2874 | continue; | |
2875 | ||
e5d1367f | 2876 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2877 | } |
d010b332 | 2878 | |
45ac1403 AH |
2879 | if (atomic_read(&nr_switch_events)) |
2880 | perf_event_switch(task, prev, true); | |
2881 | ||
ba532500 YZ |
2882 | if (__this_cpu_read(perf_sched_cb_usages)) |
2883 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2884 | } |
2885 | ||
abd50713 PZ |
2886 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2887 | { | |
2888 | u64 frequency = event->attr.sample_freq; | |
2889 | u64 sec = NSEC_PER_SEC; | |
2890 | u64 divisor, dividend; | |
2891 | ||
2892 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2893 | ||
2894 | count_fls = fls64(count); | |
2895 | nsec_fls = fls64(nsec); | |
2896 | frequency_fls = fls64(frequency); | |
2897 | sec_fls = 30; | |
2898 | ||
2899 | /* | |
2900 | * We got @count in @nsec, with a target of sample_freq HZ | |
2901 | * the target period becomes: | |
2902 | * | |
2903 | * @count * 10^9 | |
2904 | * period = ------------------- | |
2905 | * @nsec * sample_freq | |
2906 | * | |
2907 | */ | |
2908 | ||
2909 | /* | |
2910 | * Reduce accuracy by one bit such that @a and @b converge | |
2911 | * to a similar magnitude. | |
2912 | */ | |
fe4b04fa | 2913 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2914 | do { \ |
2915 | if (a##_fls > b##_fls) { \ | |
2916 | a >>= 1; \ | |
2917 | a##_fls--; \ | |
2918 | } else { \ | |
2919 | b >>= 1; \ | |
2920 | b##_fls--; \ | |
2921 | } \ | |
2922 | } while (0) | |
2923 | ||
2924 | /* | |
2925 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2926 | * the other, so that finally we can do a u64/u64 division. | |
2927 | */ | |
2928 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2929 | REDUCE_FLS(nsec, frequency); | |
2930 | REDUCE_FLS(sec, count); | |
2931 | } | |
2932 | ||
2933 | if (count_fls + sec_fls > 64) { | |
2934 | divisor = nsec * frequency; | |
2935 | ||
2936 | while (count_fls + sec_fls > 64) { | |
2937 | REDUCE_FLS(count, sec); | |
2938 | divisor >>= 1; | |
2939 | } | |
2940 | ||
2941 | dividend = count * sec; | |
2942 | } else { | |
2943 | dividend = count * sec; | |
2944 | ||
2945 | while (nsec_fls + frequency_fls > 64) { | |
2946 | REDUCE_FLS(nsec, frequency); | |
2947 | dividend >>= 1; | |
2948 | } | |
2949 | ||
2950 | divisor = nsec * frequency; | |
2951 | } | |
2952 | ||
f6ab91ad PZ |
2953 | if (!divisor) |
2954 | return dividend; | |
2955 | ||
abd50713 PZ |
2956 | return div64_u64(dividend, divisor); |
2957 | } | |
2958 | ||
e050e3f0 SE |
2959 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2960 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2961 | ||
f39d47ff | 2962 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2963 | { |
cdd6c482 | 2964 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2965 | s64 period, sample_period; |
bd2b5b12 PZ |
2966 | s64 delta; |
2967 | ||
abd50713 | 2968 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2969 | |
2970 | delta = (s64)(period - hwc->sample_period); | |
2971 | delta = (delta + 7) / 8; /* low pass filter */ | |
2972 | ||
2973 | sample_period = hwc->sample_period + delta; | |
2974 | ||
2975 | if (!sample_period) | |
2976 | sample_period = 1; | |
2977 | ||
bd2b5b12 | 2978 | hwc->sample_period = sample_period; |
abd50713 | 2979 | |
e7850595 | 2980 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2981 | if (disable) |
2982 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2983 | ||
e7850595 | 2984 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2985 | |
2986 | if (disable) | |
2987 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2988 | } |
bd2b5b12 PZ |
2989 | } |
2990 | ||
e050e3f0 SE |
2991 | /* |
2992 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2993 | * events. At the same time, make sure, having freq events does not change | |
2994 | * the rate of unthrottling as that would introduce bias. | |
2995 | */ | |
2996 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2997 | int needs_unthr) | |
60db5e09 | 2998 | { |
cdd6c482 IM |
2999 | struct perf_event *event; |
3000 | struct hw_perf_event *hwc; | |
e050e3f0 | 3001 | u64 now, period = TICK_NSEC; |
abd50713 | 3002 | s64 delta; |
60db5e09 | 3003 | |
e050e3f0 SE |
3004 | /* |
3005 | * only need to iterate over all events iff: | |
3006 | * - context have events in frequency mode (needs freq adjust) | |
3007 | * - there are events to unthrottle on this cpu | |
3008 | */ | |
3009 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
3010 | return; |
3011 | ||
e050e3f0 | 3012 | raw_spin_lock(&ctx->lock); |
f39d47ff | 3013 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 3014 | |
03541f8b | 3015 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 3016 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
3017 | continue; |
3018 | ||
5632ab12 | 3019 | if (!event_filter_match(event)) |
5d27c23d PZ |
3020 | continue; |
3021 | ||
44377277 AS |
3022 | perf_pmu_disable(event->pmu); |
3023 | ||
cdd6c482 | 3024 | hwc = &event->hw; |
6a24ed6c | 3025 | |
ae23bff1 | 3026 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 3027 | hwc->interrupts = 0; |
cdd6c482 | 3028 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3029 | event->pmu->start(event, 0); |
a78ac325 PZ |
3030 | } |
3031 | ||
cdd6c482 | 3032 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3033 | goto next; |
60db5e09 | 3034 | |
e050e3f0 SE |
3035 | /* |
3036 | * stop the event and update event->count | |
3037 | */ | |
3038 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3039 | ||
e7850595 | 3040 | now = local64_read(&event->count); |
abd50713 PZ |
3041 | delta = now - hwc->freq_count_stamp; |
3042 | hwc->freq_count_stamp = now; | |
60db5e09 | 3043 | |
e050e3f0 SE |
3044 | /* |
3045 | * restart the event | |
3046 | * reload only if value has changed | |
f39d47ff SE |
3047 | * we have stopped the event so tell that |
3048 | * to perf_adjust_period() to avoid stopping it | |
3049 | * twice. | |
e050e3f0 | 3050 | */ |
abd50713 | 3051 | if (delta > 0) |
f39d47ff | 3052 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3053 | |
3054 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3055 | next: |
3056 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3057 | } |
e050e3f0 | 3058 | |
f39d47ff | 3059 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3060 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3061 | } |
3062 | ||
235c7fc7 | 3063 | /* |
cdd6c482 | 3064 | * Round-robin a context's events: |
235c7fc7 | 3065 | */ |
cdd6c482 | 3066 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3067 | { |
dddd3379 TG |
3068 | /* |
3069 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3070 | * disabled by the inheritance code. | |
3071 | */ | |
3072 | if (!ctx->rotate_disable) | |
3073 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3074 | } |
3075 | ||
9e630205 | 3076 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3077 | { |
8dc85d54 | 3078 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3079 | int rotate = 0; |
7fc23a53 | 3080 | |
b5ab4cd5 | 3081 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3082 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3083 | rotate = 1; | |
3084 | } | |
235c7fc7 | 3085 | |
8dc85d54 | 3086 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3087 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3088 | if (ctx->nr_events != ctx->nr_active) |
3089 | rotate = 1; | |
3090 | } | |
9717e6cd | 3091 | |
e050e3f0 | 3092 | if (!rotate) |
0f5a2601 PZ |
3093 | goto done; |
3094 | ||
facc4307 | 3095 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3096 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3097 | |
e050e3f0 SE |
3098 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3099 | if (ctx) | |
3100 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3101 | |
e050e3f0 SE |
3102 | rotate_ctx(&cpuctx->ctx); |
3103 | if (ctx) | |
3104 | rotate_ctx(ctx); | |
235c7fc7 | 3105 | |
e050e3f0 | 3106 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3107 | |
0f5a2601 PZ |
3108 | perf_pmu_enable(cpuctx->ctx.pmu); |
3109 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3110 | done: |
9e630205 SE |
3111 | |
3112 | return rotate; | |
e9d2b064 PZ |
3113 | } |
3114 | ||
026249ef FW |
3115 | #ifdef CONFIG_NO_HZ_FULL |
3116 | bool perf_event_can_stop_tick(void) | |
3117 | { | |
948b26b6 | 3118 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3119 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3120 | return false; |
d84153d6 FW |
3121 | else |
3122 | return true; | |
026249ef FW |
3123 | } |
3124 | #endif | |
3125 | ||
e9d2b064 PZ |
3126 | void perf_event_task_tick(void) |
3127 | { | |
2fde4f94 MR |
3128 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3129 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3130 | int throttled; |
b5ab4cd5 | 3131 | |
e9d2b064 PZ |
3132 | WARN_ON(!irqs_disabled()); |
3133 | ||
e050e3f0 SE |
3134 | __this_cpu_inc(perf_throttled_seq); |
3135 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3136 | ||
2fde4f94 | 3137 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3138 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3139 | } |
3140 | ||
889ff015 FW |
3141 | static int event_enable_on_exec(struct perf_event *event, |
3142 | struct perf_event_context *ctx) | |
3143 | { | |
3144 | if (!event->attr.enable_on_exec) | |
3145 | return 0; | |
3146 | ||
3147 | event->attr.enable_on_exec = 0; | |
3148 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3149 | return 0; | |
3150 | ||
1d9b482e | 3151 | __perf_event_mark_enabled(event); |
889ff015 FW |
3152 | |
3153 | return 1; | |
3154 | } | |
3155 | ||
57e7986e | 3156 | /* |
cdd6c482 | 3157 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3158 | * This expects task == current. |
3159 | */ | |
c1274499 | 3160 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3161 | { |
c1274499 | 3162 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3163 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3164 | struct perf_event *event; |
57e7986e PM |
3165 | unsigned long flags; |
3166 | int enabled = 0; | |
3167 | ||
3168 | local_irq_save(flags); | |
c1274499 | 3169 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3170 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3171 | goto out; |
3172 | ||
3e349507 PZ |
3173 | cpuctx = __get_cpu_context(ctx); |
3174 | perf_ctx_lock(cpuctx, ctx); | |
7fce2509 | 3175 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
3e349507 PZ |
3176 | list_for_each_entry(event, &ctx->event_list, event_entry) |
3177 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3178 | |
3179 | /* | |
3e349507 | 3180 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3181 | */ |
3e349507 | 3182 | if (enabled) { |
211de6eb | 3183 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3184 | ctx_resched(cpuctx, ctx); |
3185 | } | |
3186 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3187 | |
9ed6060d | 3188 | out: |
57e7986e | 3189 | local_irq_restore(flags); |
211de6eb PZ |
3190 | |
3191 | if (clone_ctx) | |
3192 | put_ctx(clone_ctx); | |
57e7986e PM |
3193 | } |
3194 | ||
e041e328 PZ |
3195 | void perf_event_exec(void) |
3196 | { | |
e041e328 PZ |
3197 | int ctxn; |
3198 | ||
3199 | rcu_read_lock(); | |
c1274499 PZ |
3200 | for_each_task_context_nr(ctxn) |
3201 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3202 | rcu_read_unlock(); |
3203 | } | |
3204 | ||
0492d4c5 PZ |
3205 | struct perf_read_data { |
3206 | struct perf_event *event; | |
3207 | bool group; | |
7d88962e | 3208 | int ret; |
0492d4c5 PZ |
3209 | }; |
3210 | ||
0793a61d | 3211 | /* |
cdd6c482 | 3212 | * Cross CPU call to read the hardware event |
0793a61d | 3213 | */ |
cdd6c482 | 3214 | static void __perf_event_read(void *info) |
0793a61d | 3215 | { |
0492d4c5 PZ |
3216 | struct perf_read_data *data = info; |
3217 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3218 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3219 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3220 | struct pmu *pmu = event->pmu; |
621a01ea | 3221 | |
e1ac3614 PM |
3222 | /* |
3223 | * If this is a task context, we need to check whether it is | |
3224 | * the current task context of this cpu. If not it has been | |
3225 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3226 | * event->count would have been updated to a recent sample |
3227 | * when the event was scheduled out. | |
e1ac3614 PM |
3228 | */ |
3229 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3230 | return; | |
3231 | ||
e625cce1 | 3232 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3233 | if (ctx->is_active) { |
542e72fc | 3234 | update_context_time(ctx); |
e5d1367f SE |
3235 | update_cgrp_time_from_event(event); |
3236 | } | |
0492d4c5 | 3237 | |
cdd6c482 | 3238 | update_event_times(event); |
4a00c16e SB |
3239 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3240 | goto unlock; | |
0492d4c5 | 3241 | |
4a00c16e SB |
3242 | if (!data->group) { |
3243 | pmu->read(event); | |
3244 | data->ret = 0; | |
0492d4c5 | 3245 | goto unlock; |
4a00c16e SB |
3246 | } |
3247 | ||
3248 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3249 | ||
3250 | pmu->read(event); | |
0492d4c5 PZ |
3251 | |
3252 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3253 | update_event_times(sub); | |
4a00c16e SB |
3254 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3255 | /* | |
3256 | * Use sibling's PMU rather than @event's since | |
3257 | * sibling could be on different (eg: software) PMU. | |
3258 | */ | |
0492d4c5 | 3259 | sub->pmu->read(sub); |
4a00c16e | 3260 | } |
0492d4c5 | 3261 | } |
4a00c16e SB |
3262 | |
3263 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3264 | |
3265 | unlock: | |
e625cce1 | 3266 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3267 | } |
3268 | ||
b5e58793 PZ |
3269 | static inline u64 perf_event_count(struct perf_event *event) |
3270 | { | |
eacd3ecc MF |
3271 | if (event->pmu->count) |
3272 | return event->pmu->count(event); | |
3273 | ||
3274 | return __perf_event_count(event); | |
b5e58793 PZ |
3275 | } |
3276 | ||
ffe8690c KX |
3277 | /* |
3278 | * NMI-safe method to read a local event, that is an event that | |
3279 | * is: | |
3280 | * - either for the current task, or for this CPU | |
3281 | * - does not have inherit set, for inherited task events | |
3282 | * will not be local and we cannot read them atomically | |
3283 | * - must not have a pmu::count method | |
3284 | */ | |
3285 | u64 perf_event_read_local(struct perf_event *event) | |
3286 | { | |
3287 | unsigned long flags; | |
3288 | u64 val; | |
3289 | ||
3290 | /* | |
3291 | * Disabling interrupts avoids all counter scheduling (context | |
3292 | * switches, timer based rotation and IPIs). | |
3293 | */ | |
3294 | local_irq_save(flags); | |
3295 | ||
3296 | /* If this is a per-task event, it must be for current */ | |
3297 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3298 | event->hw.target != current); | |
3299 | ||
3300 | /* If this is a per-CPU event, it must be for this CPU */ | |
3301 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3302 | event->cpu != smp_processor_id()); | |
3303 | ||
3304 | /* | |
3305 | * It must not be an event with inherit set, we cannot read | |
3306 | * all child counters from atomic context. | |
3307 | */ | |
3308 | WARN_ON_ONCE(event->attr.inherit); | |
3309 | ||
3310 | /* | |
3311 | * It must not have a pmu::count method, those are not | |
3312 | * NMI safe. | |
3313 | */ | |
3314 | WARN_ON_ONCE(event->pmu->count); | |
3315 | ||
3316 | /* | |
3317 | * If the event is currently on this CPU, its either a per-task event, | |
3318 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3319 | * oncpu == -1). | |
3320 | */ | |
3321 | if (event->oncpu == smp_processor_id()) | |
3322 | event->pmu->read(event); | |
3323 | ||
3324 | val = local64_read(&event->count); | |
3325 | local_irq_restore(flags); | |
3326 | ||
3327 | return val; | |
3328 | } | |
3329 | ||
7d88962e | 3330 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3331 | { |
7d88962e SB |
3332 | int ret = 0; |
3333 | ||
0793a61d | 3334 | /* |
cdd6c482 IM |
3335 | * If event is enabled and currently active on a CPU, update the |
3336 | * value in the event structure: | |
0793a61d | 3337 | */ |
cdd6c482 | 3338 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3339 | struct perf_read_data data = { |
3340 | .event = event, | |
3341 | .group = group, | |
7d88962e | 3342 | .ret = 0, |
0492d4c5 | 3343 | }; |
cdd6c482 | 3344 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3345 | __perf_event_read, &data, 1); |
7d88962e | 3346 | ret = data.ret; |
cdd6c482 | 3347 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3348 | struct perf_event_context *ctx = event->ctx; |
3349 | unsigned long flags; | |
3350 | ||
e625cce1 | 3351 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3352 | /* |
3353 | * may read while context is not active | |
3354 | * (e.g., thread is blocked), in that case | |
3355 | * we cannot update context time | |
3356 | */ | |
e5d1367f | 3357 | if (ctx->is_active) { |
c530ccd9 | 3358 | update_context_time(ctx); |
e5d1367f SE |
3359 | update_cgrp_time_from_event(event); |
3360 | } | |
0492d4c5 PZ |
3361 | if (group) |
3362 | update_group_times(event); | |
3363 | else | |
3364 | update_event_times(event); | |
e625cce1 | 3365 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3366 | } |
7d88962e SB |
3367 | |
3368 | return ret; | |
0793a61d TG |
3369 | } |
3370 | ||
a63eaf34 | 3371 | /* |
cdd6c482 | 3372 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3373 | */ |
eb184479 | 3374 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3375 | { |
e625cce1 | 3376 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3377 | mutex_init(&ctx->mutex); |
2fde4f94 | 3378 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3379 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3380 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3381 | INIT_LIST_HEAD(&ctx->event_list); |
3382 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3383 | } |
3384 | ||
3385 | static struct perf_event_context * | |
3386 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3387 | { | |
3388 | struct perf_event_context *ctx; | |
3389 | ||
3390 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3391 | if (!ctx) | |
3392 | return NULL; | |
3393 | ||
3394 | __perf_event_init_context(ctx); | |
3395 | if (task) { | |
3396 | ctx->task = task; | |
3397 | get_task_struct(task); | |
0793a61d | 3398 | } |
eb184479 PZ |
3399 | ctx->pmu = pmu; |
3400 | ||
3401 | return ctx; | |
a63eaf34 PM |
3402 | } |
3403 | ||
2ebd4ffb MH |
3404 | static struct task_struct * |
3405 | find_lively_task_by_vpid(pid_t vpid) | |
3406 | { | |
3407 | struct task_struct *task; | |
3408 | int err; | |
0793a61d TG |
3409 | |
3410 | rcu_read_lock(); | |
2ebd4ffb | 3411 | if (!vpid) |
0793a61d TG |
3412 | task = current; |
3413 | else | |
2ebd4ffb | 3414 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3415 | if (task) |
3416 | get_task_struct(task); | |
3417 | rcu_read_unlock(); | |
3418 | ||
3419 | if (!task) | |
3420 | return ERR_PTR(-ESRCH); | |
3421 | ||
0793a61d | 3422 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3423 | err = -EACCES; |
caaee623 | 3424 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3425 | goto errout; |
3426 | ||
2ebd4ffb MH |
3427 | return task; |
3428 | errout: | |
3429 | put_task_struct(task); | |
3430 | return ERR_PTR(err); | |
3431 | ||
3432 | } | |
3433 | ||
fe4b04fa PZ |
3434 | /* |
3435 | * Returns a matching context with refcount and pincount. | |
3436 | */ | |
108b02cf | 3437 | static struct perf_event_context * |
4af57ef2 YZ |
3438 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3439 | struct perf_event *event) | |
0793a61d | 3440 | { |
211de6eb | 3441 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3442 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3443 | void *task_ctx_data = NULL; |
25346b93 | 3444 | unsigned long flags; |
8dc85d54 | 3445 | int ctxn, err; |
4af57ef2 | 3446 | int cpu = event->cpu; |
0793a61d | 3447 | |
22a4ec72 | 3448 | if (!task) { |
cdd6c482 | 3449 | /* Must be root to operate on a CPU event: */ |
0764771d | 3450 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3451 | return ERR_PTR(-EACCES); |
3452 | ||
0793a61d | 3453 | /* |
cdd6c482 | 3454 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3455 | * offline CPU and activate it when the CPU comes up, but |
3456 | * that's for later. | |
3457 | */ | |
f6325e30 | 3458 | if (!cpu_online(cpu)) |
0793a61d TG |
3459 | return ERR_PTR(-ENODEV); |
3460 | ||
108b02cf | 3461 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3462 | ctx = &cpuctx->ctx; |
c93f7669 | 3463 | get_ctx(ctx); |
fe4b04fa | 3464 | ++ctx->pin_count; |
0793a61d | 3465 | |
0793a61d TG |
3466 | return ctx; |
3467 | } | |
3468 | ||
8dc85d54 PZ |
3469 | err = -EINVAL; |
3470 | ctxn = pmu->task_ctx_nr; | |
3471 | if (ctxn < 0) | |
3472 | goto errout; | |
3473 | ||
4af57ef2 YZ |
3474 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3475 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3476 | if (!task_ctx_data) { | |
3477 | err = -ENOMEM; | |
3478 | goto errout; | |
3479 | } | |
3480 | } | |
3481 | ||
9ed6060d | 3482 | retry: |
8dc85d54 | 3483 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3484 | if (ctx) { |
211de6eb | 3485 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3486 | ++ctx->pin_count; |
4af57ef2 YZ |
3487 | |
3488 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3489 | ctx->task_ctx_data = task_ctx_data; | |
3490 | task_ctx_data = NULL; | |
3491 | } | |
e625cce1 | 3492 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3493 | |
3494 | if (clone_ctx) | |
3495 | put_ctx(clone_ctx); | |
9137fb28 | 3496 | } else { |
eb184479 | 3497 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3498 | err = -ENOMEM; |
3499 | if (!ctx) | |
3500 | goto errout; | |
eb184479 | 3501 | |
4af57ef2 YZ |
3502 | if (task_ctx_data) { |
3503 | ctx->task_ctx_data = task_ctx_data; | |
3504 | task_ctx_data = NULL; | |
3505 | } | |
3506 | ||
dbe08d82 ON |
3507 | err = 0; |
3508 | mutex_lock(&task->perf_event_mutex); | |
3509 | /* | |
3510 | * If it has already passed perf_event_exit_task(). | |
3511 | * we must see PF_EXITING, it takes this mutex too. | |
3512 | */ | |
3513 | if (task->flags & PF_EXITING) | |
3514 | err = -ESRCH; | |
3515 | else if (task->perf_event_ctxp[ctxn]) | |
3516 | err = -EAGAIN; | |
fe4b04fa | 3517 | else { |
9137fb28 | 3518 | get_ctx(ctx); |
fe4b04fa | 3519 | ++ctx->pin_count; |
dbe08d82 | 3520 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3521 | } |
dbe08d82 ON |
3522 | mutex_unlock(&task->perf_event_mutex); |
3523 | ||
3524 | if (unlikely(err)) { | |
9137fb28 | 3525 | put_ctx(ctx); |
dbe08d82 ON |
3526 | |
3527 | if (err == -EAGAIN) | |
3528 | goto retry; | |
3529 | goto errout; | |
a63eaf34 PM |
3530 | } |
3531 | } | |
3532 | ||
4af57ef2 | 3533 | kfree(task_ctx_data); |
0793a61d | 3534 | return ctx; |
c93f7669 | 3535 | |
9ed6060d | 3536 | errout: |
4af57ef2 | 3537 | kfree(task_ctx_data); |
c93f7669 | 3538 | return ERR_PTR(err); |
0793a61d TG |
3539 | } |
3540 | ||
6fb2915d | 3541 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3542 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3543 | |
cdd6c482 | 3544 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3545 | { |
cdd6c482 | 3546 | struct perf_event *event; |
592903cd | 3547 | |
cdd6c482 IM |
3548 | event = container_of(head, struct perf_event, rcu_head); |
3549 | if (event->ns) | |
3550 | put_pid_ns(event->ns); | |
6fb2915d | 3551 | perf_event_free_filter(event); |
cdd6c482 | 3552 | kfree(event); |
592903cd PZ |
3553 | } |
3554 | ||
b69cf536 PZ |
3555 | static void ring_buffer_attach(struct perf_event *event, |
3556 | struct ring_buffer *rb); | |
925d519a | 3557 | |
4beb31f3 | 3558 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3559 | { |
4beb31f3 FW |
3560 | if (event->parent) |
3561 | return; | |
3562 | ||
4beb31f3 FW |
3563 | if (is_cgroup_event(event)) |
3564 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3565 | } | |
925d519a | 3566 | |
4beb31f3 FW |
3567 | static void unaccount_event(struct perf_event *event) |
3568 | { | |
25432ae9 PZ |
3569 | bool dec = false; |
3570 | ||
4beb31f3 FW |
3571 | if (event->parent) |
3572 | return; | |
3573 | ||
3574 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3575 | dec = true; |
4beb31f3 FW |
3576 | if (event->attr.mmap || event->attr.mmap_data) |
3577 | atomic_dec(&nr_mmap_events); | |
3578 | if (event->attr.comm) | |
3579 | atomic_dec(&nr_comm_events); | |
3580 | if (event->attr.task) | |
3581 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3582 | if (event->attr.freq) |
3583 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3584 | if (event->attr.context_switch) { |
25432ae9 | 3585 | dec = true; |
45ac1403 AH |
3586 | atomic_dec(&nr_switch_events); |
3587 | } | |
4beb31f3 | 3588 | if (is_cgroup_event(event)) |
25432ae9 | 3589 | dec = true; |
4beb31f3 | 3590 | if (has_branch_stack(event)) |
25432ae9 PZ |
3591 | dec = true; |
3592 | ||
9107c89e PZ |
3593 | if (dec) { |
3594 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
3595 | schedule_delayed_work(&perf_sched_work, HZ); | |
3596 | } | |
4beb31f3 FW |
3597 | |
3598 | unaccount_event_cpu(event, event->cpu); | |
3599 | } | |
925d519a | 3600 | |
9107c89e PZ |
3601 | static void perf_sched_delayed(struct work_struct *work) |
3602 | { | |
3603 | mutex_lock(&perf_sched_mutex); | |
3604 | if (atomic_dec_and_test(&perf_sched_count)) | |
3605 | static_branch_disable(&perf_sched_events); | |
3606 | mutex_unlock(&perf_sched_mutex); | |
3607 | } | |
3608 | ||
bed5b25a AS |
3609 | /* |
3610 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3611 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3612 | * at a time, so we disallow creating events that might conflict, namely: | |
3613 | * | |
3614 | * 1) cpu-wide events in the presence of per-task events, | |
3615 | * 2) per-task events in the presence of cpu-wide events, | |
3616 | * 3) two matching events on the same context. | |
3617 | * | |
3618 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 3619 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
3620 | */ |
3621 | static int exclusive_event_init(struct perf_event *event) | |
3622 | { | |
3623 | struct pmu *pmu = event->pmu; | |
3624 | ||
3625 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3626 | return 0; | |
3627 | ||
3628 | /* | |
3629 | * Prevent co-existence of per-task and cpu-wide events on the | |
3630 | * same exclusive pmu. | |
3631 | * | |
3632 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3633 | * events on this "exclusive" pmu, positive means there are | |
3634 | * per-task events. | |
3635 | * | |
3636 | * Since this is called in perf_event_alloc() path, event::ctx | |
3637 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3638 | * to mean "per-task event", because unlike other attach states it | |
3639 | * never gets cleared. | |
3640 | */ | |
3641 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3642 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3643 | return -EBUSY; | |
3644 | } else { | |
3645 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3646 | return -EBUSY; | |
3647 | } | |
3648 | ||
3649 | return 0; | |
3650 | } | |
3651 | ||
3652 | static void exclusive_event_destroy(struct perf_event *event) | |
3653 | { | |
3654 | struct pmu *pmu = event->pmu; | |
3655 | ||
3656 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3657 | return; | |
3658 | ||
3659 | /* see comment in exclusive_event_init() */ | |
3660 | if (event->attach_state & PERF_ATTACH_TASK) | |
3661 | atomic_dec(&pmu->exclusive_cnt); | |
3662 | else | |
3663 | atomic_inc(&pmu->exclusive_cnt); | |
3664 | } | |
3665 | ||
3666 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3667 | { | |
3668 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3669 | (e1->cpu == e2->cpu || | |
3670 | e1->cpu == -1 || | |
3671 | e2->cpu == -1)) | |
3672 | return true; | |
3673 | return false; | |
3674 | } | |
3675 | ||
3676 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3677 | static bool exclusive_event_installable(struct perf_event *event, | |
3678 | struct perf_event_context *ctx) | |
3679 | { | |
3680 | struct perf_event *iter_event; | |
3681 | struct pmu *pmu = event->pmu; | |
3682 | ||
3683 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3684 | return true; | |
3685 | ||
3686 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3687 | if (exclusive_event_match(iter_event, event)) | |
3688 | return false; | |
3689 | } | |
3690 | ||
3691 | return true; | |
3692 | } | |
3693 | ||
683ede43 | 3694 | static void _free_event(struct perf_event *event) |
f1600952 | 3695 | { |
e360adbe | 3696 | irq_work_sync(&event->pending); |
925d519a | 3697 | |
4beb31f3 | 3698 | unaccount_event(event); |
9ee318a7 | 3699 | |
76369139 | 3700 | if (event->rb) { |
9bb5d40c PZ |
3701 | /* |
3702 | * Can happen when we close an event with re-directed output. | |
3703 | * | |
3704 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3705 | * over us; possibly making our ring_buffer_put() the last. | |
3706 | */ | |
3707 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3708 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3709 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3710 | } |
3711 | ||
e5d1367f SE |
3712 | if (is_cgroup_event(event)) |
3713 | perf_detach_cgroup(event); | |
3714 | ||
a0733e69 PZ |
3715 | if (!event->parent) { |
3716 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
3717 | put_callchain_buffers(); | |
3718 | } | |
3719 | ||
3720 | perf_event_free_bpf_prog(event); | |
3721 | ||
3722 | if (event->destroy) | |
3723 | event->destroy(event); | |
3724 | ||
3725 | if (event->ctx) | |
3726 | put_ctx(event->ctx); | |
3727 | ||
3728 | if (event->pmu) { | |
3729 | exclusive_event_destroy(event); | |
3730 | module_put(event->pmu->module); | |
3731 | } | |
3732 | ||
3733 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
3734 | } |
3735 | ||
683ede43 PZ |
3736 | /* |
3737 | * Used to free events which have a known refcount of 1, such as in error paths | |
3738 | * where the event isn't exposed yet and inherited events. | |
3739 | */ | |
3740 | static void free_event(struct perf_event *event) | |
0793a61d | 3741 | { |
683ede43 PZ |
3742 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3743 | "unexpected event refcount: %ld; ptr=%p\n", | |
3744 | atomic_long_read(&event->refcount), event)) { | |
3745 | /* leak to avoid use-after-free */ | |
3746 | return; | |
3747 | } | |
0793a61d | 3748 | |
683ede43 | 3749 | _free_event(event); |
0793a61d TG |
3750 | } |
3751 | ||
a66a3052 | 3752 | /* |
f8697762 | 3753 | * Remove user event from the owner task. |
a66a3052 | 3754 | */ |
f8697762 | 3755 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3756 | { |
8882135b | 3757 | struct task_struct *owner; |
fb0459d7 | 3758 | |
8882135b | 3759 | rcu_read_lock(); |
8882135b | 3760 | /* |
f47c02c0 PZ |
3761 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
3762 | * observe !owner it means the list deletion is complete and we can | |
3763 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
3764 | * owner->perf_event_mutex. |
3765 | */ | |
f47c02c0 | 3766 | owner = lockless_dereference(event->owner); |
8882135b PZ |
3767 | if (owner) { |
3768 | /* | |
3769 | * Since delayed_put_task_struct() also drops the last | |
3770 | * task reference we can safely take a new reference | |
3771 | * while holding the rcu_read_lock(). | |
3772 | */ | |
3773 | get_task_struct(owner); | |
3774 | } | |
3775 | rcu_read_unlock(); | |
3776 | ||
3777 | if (owner) { | |
f63a8daa PZ |
3778 | /* |
3779 | * If we're here through perf_event_exit_task() we're already | |
3780 | * holding ctx->mutex which would be an inversion wrt. the | |
3781 | * normal lock order. | |
3782 | * | |
3783 | * However we can safely take this lock because its the child | |
3784 | * ctx->mutex. | |
3785 | */ | |
3786 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3787 | ||
8882135b PZ |
3788 | /* |
3789 | * We have to re-check the event->owner field, if it is cleared | |
3790 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3791 | * ensured they're done, and we can proceed with freeing the | |
3792 | * event. | |
3793 | */ | |
f47c02c0 | 3794 | if (event->owner) { |
8882135b | 3795 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
3796 | smp_store_release(&event->owner, NULL); |
3797 | } | |
8882135b PZ |
3798 | mutex_unlock(&owner->perf_event_mutex); |
3799 | put_task_struct(owner); | |
3800 | } | |
f8697762 JO |
3801 | } |
3802 | ||
f8697762 JO |
3803 | static void put_event(struct perf_event *event) |
3804 | { | |
f8697762 JO |
3805 | if (!atomic_long_dec_and_test(&event->refcount)) |
3806 | return; | |
3807 | ||
c6e5b732 PZ |
3808 | _free_event(event); |
3809 | } | |
3810 | ||
3811 | /* | |
3812 | * Kill an event dead; while event:refcount will preserve the event | |
3813 | * object, it will not preserve its functionality. Once the last 'user' | |
3814 | * gives up the object, we'll destroy the thing. | |
3815 | */ | |
3816 | int perf_event_release_kernel(struct perf_event *event) | |
3817 | { | |
a4f4bb6d | 3818 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
3819 | struct perf_event *child, *tmp; |
3820 | ||
a4f4bb6d PZ |
3821 | /* |
3822 | * If we got here through err_file: fput(event_file); we will not have | |
3823 | * attached to a context yet. | |
3824 | */ | |
3825 | if (!ctx) { | |
3826 | WARN_ON_ONCE(event->attach_state & | |
3827 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
3828 | goto no_ctx; | |
3829 | } | |
3830 | ||
f8697762 JO |
3831 | if (!is_kernel_event(event)) |
3832 | perf_remove_from_owner(event); | |
8882135b | 3833 | |
5fa7c8ec | 3834 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 3835 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 3836 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 3837 | |
a69b0ca4 | 3838 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 3839 | /* |
a69b0ca4 PZ |
3840 | * Mark this even as STATE_DEAD, there is no external reference to it |
3841 | * anymore. | |
683ede43 | 3842 | * |
a69b0ca4 PZ |
3843 | * Anybody acquiring event->child_mutex after the below loop _must_ |
3844 | * also see this, most importantly inherit_event() which will avoid | |
3845 | * placing more children on the list. | |
683ede43 | 3846 | * |
c6e5b732 PZ |
3847 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
3848 | * child events. | |
683ede43 | 3849 | */ |
a69b0ca4 PZ |
3850 | event->state = PERF_EVENT_STATE_DEAD; |
3851 | raw_spin_unlock_irq(&ctx->lock); | |
3852 | ||
3853 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 3854 | |
c6e5b732 PZ |
3855 | again: |
3856 | mutex_lock(&event->child_mutex); | |
3857 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 3858 | |
c6e5b732 PZ |
3859 | /* |
3860 | * Cannot change, child events are not migrated, see the | |
3861 | * comment with perf_event_ctx_lock_nested(). | |
3862 | */ | |
3863 | ctx = lockless_dereference(child->ctx); | |
3864 | /* | |
3865 | * Since child_mutex nests inside ctx::mutex, we must jump | |
3866 | * through hoops. We start by grabbing a reference on the ctx. | |
3867 | * | |
3868 | * Since the event cannot get freed while we hold the | |
3869 | * child_mutex, the context must also exist and have a !0 | |
3870 | * reference count. | |
3871 | */ | |
3872 | get_ctx(ctx); | |
3873 | ||
3874 | /* | |
3875 | * Now that we have a ctx ref, we can drop child_mutex, and | |
3876 | * acquire ctx::mutex without fear of it going away. Then we | |
3877 | * can re-acquire child_mutex. | |
3878 | */ | |
3879 | mutex_unlock(&event->child_mutex); | |
3880 | mutex_lock(&ctx->mutex); | |
3881 | mutex_lock(&event->child_mutex); | |
3882 | ||
3883 | /* | |
3884 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
3885 | * state, if child is still the first entry, it didn't get freed | |
3886 | * and we can continue doing so. | |
3887 | */ | |
3888 | tmp = list_first_entry_or_null(&event->child_list, | |
3889 | struct perf_event, child_list); | |
3890 | if (tmp == child) { | |
3891 | perf_remove_from_context(child, DETACH_GROUP); | |
3892 | list_del(&child->child_list); | |
3893 | free_event(child); | |
3894 | /* | |
3895 | * This matches the refcount bump in inherit_event(); | |
3896 | * this can't be the last reference. | |
3897 | */ | |
3898 | put_event(event); | |
3899 | } | |
3900 | ||
3901 | mutex_unlock(&event->child_mutex); | |
3902 | mutex_unlock(&ctx->mutex); | |
3903 | put_ctx(ctx); | |
3904 | goto again; | |
3905 | } | |
3906 | mutex_unlock(&event->child_mutex); | |
3907 | ||
a4f4bb6d PZ |
3908 | no_ctx: |
3909 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
3910 | return 0; |
3911 | } | |
3912 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3913 | ||
8b10c5e2 PZ |
3914 | /* |
3915 | * Called when the last reference to the file is gone. | |
3916 | */ | |
a6fa941d AV |
3917 | static int perf_release(struct inode *inode, struct file *file) |
3918 | { | |
c6e5b732 | 3919 | perf_event_release_kernel(file->private_data); |
a6fa941d | 3920 | return 0; |
fb0459d7 | 3921 | } |
fb0459d7 | 3922 | |
59ed446f | 3923 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3924 | { |
cdd6c482 | 3925 | struct perf_event *child; |
e53c0994 PZ |
3926 | u64 total = 0; |
3927 | ||
59ed446f PZ |
3928 | *enabled = 0; |
3929 | *running = 0; | |
3930 | ||
6f10581a | 3931 | mutex_lock(&event->child_mutex); |
01add3ea | 3932 | |
7d88962e | 3933 | (void)perf_event_read(event, false); |
01add3ea SB |
3934 | total += perf_event_count(event); |
3935 | ||
59ed446f PZ |
3936 | *enabled += event->total_time_enabled + |
3937 | atomic64_read(&event->child_total_time_enabled); | |
3938 | *running += event->total_time_running + | |
3939 | atomic64_read(&event->child_total_time_running); | |
3940 | ||
3941 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3942 | (void)perf_event_read(child, false); |
01add3ea | 3943 | total += perf_event_count(child); |
59ed446f PZ |
3944 | *enabled += child->total_time_enabled; |
3945 | *running += child->total_time_running; | |
3946 | } | |
6f10581a | 3947 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3948 | |
3949 | return total; | |
3950 | } | |
fb0459d7 | 3951 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3952 | |
7d88962e | 3953 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3954 | u64 read_format, u64 *values) |
3dab77fb | 3955 | { |
fa8c2693 PZ |
3956 | struct perf_event *sub; |
3957 | int n = 1; /* skip @nr */ | |
7d88962e | 3958 | int ret; |
f63a8daa | 3959 | |
7d88962e SB |
3960 | ret = perf_event_read(leader, true); |
3961 | if (ret) | |
3962 | return ret; | |
abf4868b | 3963 | |
fa8c2693 PZ |
3964 | /* |
3965 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3966 | * will be identical to those of the leader, so we only publish one | |
3967 | * set. | |
3968 | */ | |
3969 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3970 | values[n++] += leader->total_time_enabled + | |
3971 | atomic64_read(&leader->child_total_time_enabled); | |
3972 | } | |
3dab77fb | 3973 | |
fa8c2693 PZ |
3974 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3975 | values[n++] += leader->total_time_running + | |
3976 | atomic64_read(&leader->child_total_time_running); | |
3977 | } | |
3978 | ||
3979 | /* | |
3980 | * Write {count,id} tuples for every sibling. | |
3981 | */ | |
3982 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3983 | if (read_format & PERF_FORMAT_ID) |
3984 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3985 | |
fa8c2693 PZ |
3986 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3987 | values[n++] += perf_event_count(sub); | |
3988 | if (read_format & PERF_FORMAT_ID) | |
3989 | values[n++] = primary_event_id(sub); | |
3990 | } | |
7d88962e SB |
3991 | |
3992 | return 0; | |
fa8c2693 | 3993 | } |
3dab77fb | 3994 | |
fa8c2693 PZ |
3995 | static int perf_read_group(struct perf_event *event, |
3996 | u64 read_format, char __user *buf) | |
3997 | { | |
3998 | struct perf_event *leader = event->group_leader, *child; | |
3999 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 4000 | int ret; |
fa8c2693 | 4001 | u64 *values; |
3dab77fb | 4002 | |
fa8c2693 | 4003 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 4004 | |
fa8c2693 PZ |
4005 | values = kzalloc(event->read_size, GFP_KERNEL); |
4006 | if (!values) | |
4007 | return -ENOMEM; | |
3dab77fb | 4008 | |
fa8c2693 PZ |
4009 | values[0] = 1 + leader->nr_siblings; |
4010 | ||
4011 | /* | |
4012 | * By locking the child_mutex of the leader we effectively | |
4013 | * lock the child list of all siblings.. XXX explain how. | |
4014 | */ | |
4015 | mutex_lock(&leader->child_mutex); | |
abf4868b | 4016 | |
7d88962e SB |
4017 | ret = __perf_read_group_add(leader, read_format, values); |
4018 | if (ret) | |
4019 | goto unlock; | |
4020 | ||
4021 | list_for_each_entry(child, &leader->child_list, child_list) { | |
4022 | ret = __perf_read_group_add(child, read_format, values); | |
4023 | if (ret) | |
4024 | goto unlock; | |
4025 | } | |
abf4868b | 4026 | |
fa8c2693 | 4027 | mutex_unlock(&leader->child_mutex); |
abf4868b | 4028 | |
7d88962e | 4029 | ret = event->read_size; |
fa8c2693 PZ |
4030 | if (copy_to_user(buf, values, event->read_size)) |
4031 | ret = -EFAULT; | |
7d88962e | 4032 | goto out; |
fa8c2693 | 4033 | |
7d88962e SB |
4034 | unlock: |
4035 | mutex_unlock(&leader->child_mutex); | |
4036 | out: | |
fa8c2693 | 4037 | kfree(values); |
abf4868b | 4038 | return ret; |
3dab77fb PZ |
4039 | } |
4040 | ||
b15f495b | 4041 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4042 | u64 read_format, char __user *buf) |
4043 | { | |
59ed446f | 4044 | u64 enabled, running; |
3dab77fb PZ |
4045 | u64 values[4]; |
4046 | int n = 0; | |
4047 | ||
59ed446f PZ |
4048 | values[n++] = perf_event_read_value(event, &enabled, &running); |
4049 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4050 | values[n++] = enabled; | |
4051 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4052 | values[n++] = running; | |
3dab77fb | 4053 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4054 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4055 | |
4056 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4057 | return -EFAULT; | |
4058 | ||
4059 | return n * sizeof(u64); | |
4060 | } | |
4061 | ||
dc633982 JO |
4062 | static bool is_event_hup(struct perf_event *event) |
4063 | { | |
4064 | bool no_children; | |
4065 | ||
a69b0ca4 | 4066 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4067 | return false; |
4068 | ||
4069 | mutex_lock(&event->child_mutex); | |
4070 | no_children = list_empty(&event->child_list); | |
4071 | mutex_unlock(&event->child_mutex); | |
4072 | return no_children; | |
4073 | } | |
4074 | ||
0793a61d | 4075 | /* |
cdd6c482 | 4076 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4077 | */ |
4078 | static ssize_t | |
b15f495b | 4079 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4080 | { |
cdd6c482 | 4081 | u64 read_format = event->attr.read_format; |
3dab77fb | 4082 | int ret; |
0793a61d | 4083 | |
3b6f9e5c | 4084 | /* |
cdd6c482 | 4085 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4086 | * error state (i.e. because it was pinned but it couldn't be |
4087 | * scheduled on to the CPU at some point). | |
4088 | */ | |
cdd6c482 | 4089 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4090 | return 0; |
4091 | ||
c320c7b7 | 4092 | if (count < event->read_size) |
3dab77fb PZ |
4093 | return -ENOSPC; |
4094 | ||
cdd6c482 | 4095 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4096 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4097 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4098 | else |
b15f495b | 4099 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4100 | |
3dab77fb | 4101 | return ret; |
0793a61d TG |
4102 | } |
4103 | ||
0793a61d TG |
4104 | static ssize_t |
4105 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4106 | { | |
cdd6c482 | 4107 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4108 | struct perf_event_context *ctx; |
4109 | int ret; | |
0793a61d | 4110 | |
f63a8daa | 4111 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4112 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4113 | perf_event_ctx_unlock(event, ctx); |
4114 | ||
4115 | return ret; | |
0793a61d TG |
4116 | } |
4117 | ||
4118 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4119 | { | |
cdd6c482 | 4120 | struct perf_event *event = file->private_data; |
76369139 | 4121 | struct ring_buffer *rb; |
61b67684 | 4122 | unsigned int events = POLLHUP; |
c7138f37 | 4123 | |
e708d7ad | 4124 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4125 | |
dc633982 | 4126 | if (is_event_hup(event)) |
179033b3 | 4127 | return events; |
c7138f37 | 4128 | |
10c6db11 | 4129 | /* |
9bb5d40c PZ |
4130 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4131 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4132 | */ |
4133 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4134 | rb = event->rb; |
4135 | if (rb) | |
76369139 | 4136 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4137 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4138 | return events; |
4139 | } | |
4140 | ||
f63a8daa | 4141 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4142 | { |
7d88962e | 4143 | (void)perf_event_read(event, false); |
e7850595 | 4144 | local64_set(&event->count, 0); |
cdd6c482 | 4145 | perf_event_update_userpage(event); |
3df5edad PZ |
4146 | } |
4147 | ||
c93f7669 | 4148 | /* |
cdd6c482 IM |
4149 | * Holding the top-level event's child_mutex means that any |
4150 | * descendant process that has inherited this event will block | |
8ba289b8 | 4151 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4152 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4153 | */ |
cdd6c482 IM |
4154 | static void perf_event_for_each_child(struct perf_event *event, |
4155 | void (*func)(struct perf_event *)) | |
3df5edad | 4156 | { |
cdd6c482 | 4157 | struct perf_event *child; |
3df5edad | 4158 | |
cdd6c482 | 4159 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4160 | |
cdd6c482 IM |
4161 | mutex_lock(&event->child_mutex); |
4162 | func(event); | |
4163 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4164 | func(child); |
cdd6c482 | 4165 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4166 | } |
4167 | ||
cdd6c482 IM |
4168 | static void perf_event_for_each(struct perf_event *event, |
4169 | void (*func)(struct perf_event *)) | |
3df5edad | 4170 | { |
cdd6c482 IM |
4171 | struct perf_event_context *ctx = event->ctx; |
4172 | struct perf_event *sibling; | |
3df5edad | 4173 | |
f63a8daa PZ |
4174 | lockdep_assert_held(&ctx->mutex); |
4175 | ||
cdd6c482 | 4176 | event = event->group_leader; |
75f937f2 | 4177 | |
cdd6c482 | 4178 | perf_event_for_each_child(event, func); |
cdd6c482 | 4179 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4180 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4181 | } |
4182 | ||
fae3fde6 PZ |
4183 | static void __perf_event_period(struct perf_event *event, |
4184 | struct perf_cpu_context *cpuctx, | |
4185 | struct perf_event_context *ctx, | |
4186 | void *info) | |
c7999c6f | 4187 | { |
fae3fde6 | 4188 | u64 value = *((u64 *)info); |
c7999c6f | 4189 | bool active; |
08247e31 | 4190 | |
cdd6c482 | 4191 | if (event->attr.freq) { |
cdd6c482 | 4192 | event->attr.sample_freq = value; |
08247e31 | 4193 | } else { |
cdd6c482 IM |
4194 | event->attr.sample_period = value; |
4195 | event->hw.sample_period = value; | |
08247e31 | 4196 | } |
bad7192b PZ |
4197 | |
4198 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4199 | if (active) { | |
4200 | perf_pmu_disable(ctx->pmu); | |
4201 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4202 | } | |
4203 | ||
4204 | local64_set(&event->hw.period_left, 0); | |
4205 | ||
4206 | if (active) { | |
4207 | event->pmu->start(event, PERF_EF_RELOAD); | |
4208 | perf_pmu_enable(ctx->pmu); | |
4209 | } | |
c7999c6f PZ |
4210 | } |
4211 | ||
4212 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4213 | { | |
c7999c6f PZ |
4214 | u64 value; |
4215 | ||
4216 | if (!is_sampling_event(event)) | |
4217 | return -EINVAL; | |
4218 | ||
4219 | if (copy_from_user(&value, arg, sizeof(value))) | |
4220 | return -EFAULT; | |
4221 | ||
4222 | if (!value) | |
4223 | return -EINVAL; | |
4224 | ||
4225 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4226 | return -EINVAL; | |
4227 | ||
fae3fde6 | 4228 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4229 | |
c7999c6f | 4230 | return 0; |
08247e31 PZ |
4231 | } |
4232 | ||
ac9721f3 PZ |
4233 | static const struct file_operations perf_fops; |
4234 | ||
2903ff01 | 4235 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4236 | { |
2903ff01 AV |
4237 | struct fd f = fdget(fd); |
4238 | if (!f.file) | |
4239 | return -EBADF; | |
ac9721f3 | 4240 | |
2903ff01 AV |
4241 | if (f.file->f_op != &perf_fops) { |
4242 | fdput(f); | |
4243 | return -EBADF; | |
ac9721f3 | 4244 | } |
2903ff01 AV |
4245 | *p = f; |
4246 | return 0; | |
ac9721f3 PZ |
4247 | } |
4248 | ||
4249 | static int perf_event_set_output(struct perf_event *event, | |
4250 | struct perf_event *output_event); | |
6fb2915d | 4251 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4252 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4253 | |
f63a8daa | 4254 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4255 | { |
cdd6c482 | 4256 | void (*func)(struct perf_event *); |
3df5edad | 4257 | u32 flags = arg; |
d859e29f PM |
4258 | |
4259 | switch (cmd) { | |
cdd6c482 | 4260 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4261 | func = _perf_event_enable; |
d859e29f | 4262 | break; |
cdd6c482 | 4263 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4264 | func = _perf_event_disable; |
79f14641 | 4265 | break; |
cdd6c482 | 4266 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4267 | func = _perf_event_reset; |
6de6a7b9 | 4268 | break; |
3df5edad | 4269 | |
cdd6c482 | 4270 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4271 | return _perf_event_refresh(event, arg); |
08247e31 | 4272 | |
cdd6c482 IM |
4273 | case PERF_EVENT_IOC_PERIOD: |
4274 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4275 | |
cf4957f1 JO |
4276 | case PERF_EVENT_IOC_ID: |
4277 | { | |
4278 | u64 id = primary_event_id(event); | |
4279 | ||
4280 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4281 | return -EFAULT; | |
4282 | return 0; | |
4283 | } | |
4284 | ||
cdd6c482 | 4285 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4286 | { |
ac9721f3 | 4287 | int ret; |
ac9721f3 | 4288 | if (arg != -1) { |
2903ff01 AV |
4289 | struct perf_event *output_event; |
4290 | struct fd output; | |
4291 | ret = perf_fget_light(arg, &output); | |
4292 | if (ret) | |
4293 | return ret; | |
4294 | output_event = output.file->private_data; | |
4295 | ret = perf_event_set_output(event, output_event); | |
4296 | fdput(output); | |
4297 | } else { | |
4298 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4299 | } |
ac9721f3 PZ |
4300 | return ret; |
4301 | } | |
a4be7c27 | 4302 | |
6fb2915d LZ |
4303 | case PERF_EVENT_IOC_SET_FILTER: |
4304 | return perf_event_set_filter(event, (void __user *)arg); | |
4305 | ||
2541517c AS |
4306 | case PERF_EVENT_IOC_SET_BPF: |
4307 | return perf_event_set_bpf_prog(event, arg); | |
4308 | ||
d859e29f | 4309 | default: |
3df5edad | 4310 | return -ENOTTY; |
d859e29f | 4311 | } |
3df5edad PZ |
4312 | |
4313 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4314 | perf_event_for_each(event, func); |
3df5edad | 4315 | else |
cdd6c482 | 4316 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4317 | |
4318 | return 0; | |
d859e29f PM |
4319 | } |
4320 | ||
f63a8daa PZ |
4321 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4322 | { | |
4323 | struct perf_event *event = file->private_data; | |
4324 | struct perf_event_context *ctx; | |
4325 | long ret; | |
4326 | ||
4327 | ctx = perf_event_ctx_lock(event); | |
4328 | ret = _perf_ioctl(event, cmd, arg); | |
4329 | perf_event_ctx_unlock(event, ctx); | |
4330 | ||
4331 | return ret; | |
4332 | } | |
4333 | ||
b3f20785 PM |
4334 | #ifdef CONFIG_COMPAT |
4335 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4336 | unsigned long arg) | |
4337 | { | |
4338 | switch (_IOC_NR(cmd)) { | |
4339 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4340 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4341 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4342 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4343 | cmd &= ~IOCSIZE_MASK; | |
4344 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4345 | } | |
4346 | break; | |
4347 | } | |
4348 | return perf_ioctl(file, cmd, arg); | |
4349 | } | |
4350 | #else | |
4351 | # define perf_compat_ioctl NULL | |
4352 | #endif | |
4353 | ||
cdd6c482 | 4354 | int perf_event_task_enable(void) |
771d7cde | 4355 | { |
f63a8daa | 4356 | struct perf_event_context *ctx; |
cdd6c482 | 4357 | struct perf_event *event; |
771d7cde | 4358 | |
cdd6c482 | 4359 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4360 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4361 | ctx = perf_event_ctx_lock(event); | |
4362 | perf_event_for_each_child(event, _perf_event_enable); | |
4363 | perf_event_ctx_unlock(event, ctx); | |
4364 | } | |
cdd6c482 | 4365 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4366 | |
4367 | return 0; | |
4368 | } | |
4369 | ||
cdd6c482 | 4370 | int perf_event_task_disable(void) |
771d7cde | 4371 | { |
f63a8daa | 4372 | struct perf_event_context *ctx; |
cdd6c482 | 4373 | struct perf_event *event; |
771d7cde | 4374 | |
cdd6c482 | 4375 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4376 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4377 | ctx = perf_event_ctx_lock(event); | |
4378 | perf_event_for_each_child(event, _perf_event_disable); | |
4379 | perf_event_ctx_unlock(event, ctx); | |
4380 | } | |
cdd6c482 | 4381 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4382 | |
4383 | return 0; | |
4384 | } | |
4385 | ||
cdd6c482 | 4386 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4387 | { |
a4eaf7f1 PZ |
4388 | if (event->hw.state & PERF_HES_STOPPED) |
4389 | return 0; | |
4390 | ||
cdd6c482 | 4391 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4392 | return 0; |
4393 | ||
35edc2a5 | 4394 | return event->pmu->event_idx(event); |
194002b2 PZ |
4395 | } |
4396 | ||
c4794295 | 4397 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4398 | u64 *now, |
7f310a5d EM |
4399 | u64 *enabled, |
4400 | u64 *running) | |
c4794295 | 4401 | { |
e3f3541c | 4402 | u64 ctx_time; |
c4794295 | 4403 | |
e3f3541c PZ |
4404 | *now = perf_clock(); |
4405 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4406 | *enabled = ctx_time - event->tstamp_enabled; |
4407 | *running = ctx_time - event->tstamp_running; | |
4408 | } | |
4409 | ||
fa731587 PZ |
4410 | static void perf_event_init_userpage(struct perf_event *event) |
4411 | { | |
4412 | struct perf_event_mmap_page *userpg; | |
4413 | struct ring_buffer *rb; | |
4414 | ||
4415 | rcu_read_lock(); | |
4416 | rb = rcu_dereference(event->rb); | |
4417 | if (!rb) | |
4418 | goto unlock; | |
4419 | ||
4420 | userpg = rb->user_page; | |
4421 | ||
4422 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4423 | userpg->cap_bit0_is_deprecated = 1; | |
4424 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4425 | userpg->data_offset = PAGE_SIZE; |
4426 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4427 | |
4428 | unlock: | |
4429 | rcu_read_unlock(); | |
4430 | } | |
4431 | ||
c1317ec2 AL |
4432 | void __weak arch_perf_update_userpage( |
4433 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4434 | { |
4435 | } | |
4436 | ||
38ff667b PZ |
4437 | /* |
4438 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4439 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4440 | * code calls this from NMI context. | |
4441 | */ | |
cdd6c482 | 4442 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4443 | { |
cdd6c482 | 4444 | struct perf_event_mmap_page *userpg; |
76369139 | 4445 | struct ring_buffer *rb; |
e3f3541c | 4446 | u64 enabled, running, now; |
38ff667b PZ |
4447 | |
4448 | rcu_read_lock(); | |
5ec4c599 PZ |
4449 | rb = rcu_dereference(event->rb); |
4450 | if (!rb) | |
4451 | goto unlock; | |
4452 | ||
0d641208 EM |
4453 | /* |
4454 | * compute total_time_enabled, total_time_running | |
4455 | * based on snapshot values taken when the event | |
4456 | * was last scheduled in. | |
4457 | * | |
4458 | * we cannot simply called update_context_time() | |
4459 | * because of locking issue as we can be called in | |
4460 | * NMI context | |
4461 | */ | |
e3f3541c | 4462 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4463 | |
76369139 | 4464 | userpg = rb->user_page; |
7b732a75 PZ |
4465 | /* |
4466 | * Disable preemption so as to not let the corresponding user-space | |
4467 | * spin too long if we get preempted. | |
4468 | */ | |
4469 | preempt_disable(); | |
37d81828 | 4470 | ++userpg->lock; |
92f22a38 | 4471 | barrier(); |
cdd6c482 | 4472 | userpg->index = perf_event_index(event); |
b5e58793 | 4473 | userpg->offset = perf_event_count(event); |
365a4038 | 4474 | if (userpg->index) |
e7850595 | 4475 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4476 | |
0d641208 | 4477 | userpg->time_enabled = enabled + |
cdd6c482 | 4478 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4479 | |
0d641208 | 4480 | userpg->time_running = running + |
cdd6c482 | 4481 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4482 | |
c1317ec2 | 4483 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4484 | |
92f22a38 | 4485 | barrier(); |
37d81828 | 4486 | ++userpg->lock; |
7b732a75 | 4487 | preempt_enable(); |
38ff667b | 4488 | unlock: |
7b732a75 | 4489 | rcu_read_unlock(); |
37d81828 PM |
4490 | } |
4491 | ||
906010b2 PZ |
4492 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4493 | { | |
4494 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4495 | struct ring_buffer *rb; |
906010b2 PZ |
4496 | int ret = VM_FAULT_SIGBUS; |
4497 | ||
4498 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4499 | if (vmf->pgoff == 0) | |
4500 | ret = 0; | |
4501 | return ret; | |
4502 | } | |
4503 | ||
4504 | rcu_read_lock(); | |
76369139 FW |
4505 | rb = rcu_dereference(event->rb); |
4506 | if (!rb) | |
906010b2 PZ |
4507 | goto unlock; |
4508 | ||
4509 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4510 | goto unlock; | |
4511 | ||
76369139 | 4512 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4513 | if (!vmf->page) |
4514 | goto unlock; | |
4515 | ||
4516 | get_page(vmf->page); | |
4517 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4518 | vmf->page->index = vmf->pgoff; | |
4519 | ||
4520 | ret = 0; | |
4521 | unlock: | |
4522 | rcu_read_unlock(); | |
4523 | ||
4524 | return ret; | |
4525 | } | |
4526 | ||
10c6db11 PZ |
4527 | static void ring_buffer_attach(struct perf_event *event, |
4528 | struct ring_buffer *rb) | |
4529 | { | |
b69cf536 | 4530 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4531 | unsigned long flags; |
4532 | ||
b69cf536 PZ |
4533 | if (event->rb) { |
4534 | /* | |
4535 | * Should be impossible, we set this when removing | |
4536 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4537 | */ | |
4538 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4539 | |
b69cf536 | 4540 | old_rb = event->rb; |
b69cf536 PZ |
4541 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4542 | list_del_rcu(&event->rb_entry); | |
4543 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4544 | |
2f993cf0 ON |
4545 | event->rcu_batches = get_state_synchronize_rcu(); |
4546 | event->rcu_pending = 1; | |
b69cf536 | 4547 | } |
10c6db11 | 4548 | |
b69cf536 | 4549 | if (rb) { |
2f993cf0 ON |
4550 | if (event->rcu_pending) { |
4551 | cond_synchronize_rcu(event->rcu_batches); | |
4552 | event->rcu_pending = 0; | |
4553 | } | |
4554 | ||
b69cf536 PZ |
4555 | spin_lock_irqsave(&rb->event_lock, flags); |
4556 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4557 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4558 | } | |
4559 | ||
4560 | rcu_assign_pointer(event->rb, rb); | |
4561 | ||
4562 | if (old_rb) { | |
4563 | ring_buffer_put(old_rb); | |
4564 | /* | |
4565 | * Since we detached before setting the new rb, so that we | |
4566 | * could attach the new rb, we could have missed a wakeup. | |
4567 | * Provide it now. | |
4568 | */ | |
4569 | wake_up_all(&event->waitq); | |
4570 | } | |
10c6db11 PZ |
4571 | } |
4572 | ||
4573 | static void ring_buffer_wakeup(struct perf_event *event) | |
4574 | { | |
4575 | struct ring_buffer *rb; | |
4576 | ||
4577 | rcu_read_lock(); | |
4578 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4579 | if (rb) { |
4580 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4581 | wake_up_all(&event->waitq); | |
4582 | } | |
10c6db11 PZ |
4583 | rcu_read_unlock(); |
4584 | } | |
4585 | ||
fdc26706 | 4586 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4587 | { |
76369139 | 4588 | struct ring_buffer *rb; |
7b732a75 | 4589 | |
ac9721f3 | 4590 | rcu_read_lock(); |
76369139 FW |
4591 | rb = rcu_dereference(event->rb); |
4592 | if (rb) { | |
4593 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4594 | rb = NULL; | |
ac9721f3 PZ |
4595 | } |
4596 | rcu_read_unlock(); | |
4597 | ||
76369139 | 4598 | return rb; |
ac9721f3 PZ |
4599 | } |
4600 | ||
fdc26706 | 4601 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4602 | { |
76369139 | 4603 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4604 | return; |
7b732a75 | 4605 | |
9bb5d40c | 4606 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4607 | |
76369139 | 4608 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4609 | } |
4610 | ||
4611 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4612 | { | |
cdd6c482 | 4613 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4614 | |
cdd6c482 | 4615 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4616 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4617 | |
45bfb2e5 PZ |
4618 | if (vma->vm_pgoff) |
4619 | atomic_inc(&event->rb->aux_mmap_count); | |
4620 | ||
1e0fb9ec AL |
4621 | if (event->pmu->event_mapped) |
4622 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4623 | } |
4624 | ||
9bb5d40c PZ |
4625 | /* |
4626 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4627 | * event, or through other events by use of perf_event_set_output(). | |
4628 | * | |
4629 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4630 | * the buffer here, where we still have a VM context. This means we need | |
4631 | * to detach all events redirecting to us. | |
4632 | */ | |
7b732a75 PZ |
4633 | static void perf_mmap_close(struct vm_area_struct *vma) |
4634 | { | |
cdd6c482 | 4635 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4636 | |
b69cf536 | 4637 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4638 | struct user_struct *mmap_user = rb->mmap_user; |
4639 | int mmap_locked = rb->mmap_locked; | |
4640 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4641 | |
1e0fb9ec AL |
4642 | if (event->pmu->event_unmapped) |
4643 | event->pmu->event_unmapped(event); | |
4644 | ||
45bfb2e5 PZ |
4645 | /* |
4646 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4647 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4648 | * serialize with perf_mmap here. | |
4649 | */ | |
4650 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4651 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4652 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4653 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4654 | ||
4655 | rb_free_aux(rb); | |
4656 | mutex_unlock(&event->mmap_mutex); | |
4657 | } | |
4658 | ||
9bb5d40c PZ |
4659 | atomic_dec(&rb->mmap_count); |
4660 | ||
4661 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4662 | goto out_put; |
9bb5d40c | 4663 | |
b69cf536 | 4664 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4665 | mutex_unlock(&event->mmap_mutex); |
4666 | ||
4667 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4668 | if (atomic_read(&rb->mmap_count)) |
4669 | goto out_put; | |
ac9721f3 | 4670 | |
9bb5d40c PZ |
4671 | /* |
4672 | * No other mmap()s, detach from all other events that might redirect | |
4673 | * into the now unreachable buffer. Somewhat complicated by the | |
4674 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4675 | */ | |
4676 | again: | |
4677 | rcu_read_lock(); | |
4678 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4679 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4680 | /* | |
4681 | * This event is en-route to free_event() which will | |
4682 | * detach it and remove it from the list. | |
4683 | */ | |
4684 | continue; | |
4685 | } | |
4686 | rcu_read_unlock(); | |
789f90fc | 4687 | |
9bb5d40c PZ |
4688 | mutex_lock(&event->mmap_mutex); |
4689 | /* | |
4690 | * Check we didn't race with perf_event_set_output() which can | |
4691 | * swizzle the rb from under us while we were waiting to | |
4692 | * acquire mmap_mutex. | |
4693 | * | |
4694 | * If we find a different rb; ignore this event, a next | |
4695 | * iteration will no longer find it on the list. We have to | |
4696 | * still restart the iteration to make sure we're not now | |
4697 | * iterating the wrong list. | |
4698 | */ | |
b69cf536 PZ |
4699 | if (event->rb == rb) |
4700 | ring_buffer_attach(event, NULL); | |
4701 | ||
cdd6c482 | 4702 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4703 | put_event(event); |
ac9721f3 | 4704 | |
9bb5d40c PZ |
4705 | /* |
4706 | * Restart the iteration; either we're on the wrong list or | |
4707 | * destroyed its integrity by doing a deletion. | |
4708 | */ | |
4709 | goto again; | |
7b732a75 | 4710 | } |
9bb5d40c PZ |
4711 | rcu_read_unlock(); |
4712 | ||
4713 | /* | |
4714 | * It could be there's still a few 0-ref events on the list; they'll | |
4715 | * get cleaned up by free_event() -- they'll also still have their | |
4716 | * ref on the rb and will free it whenever they are done with it. | |
4717 | * | |
4718 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4719 | * undo the VM accounting. | |
4720 | */ | |
4721 | ||
4722 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4723 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4724 | free_uid(mmap_user); | |
4725 | ||
b69cf536 | 4726 | out_put: |
9bb5d40c | 4727 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4728 | } |
4729 | ||
f0f37e2f | 4730 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4731 | .open = perf_mmap_open, |
45bfb2e5 | 4732 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4733 | .fault = perf_mmap_fault, |
4734 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4735 | }; |
4736 | ||
4737 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4738 | { | |
cdd6c482 | 4739 | struct perf_event *event = file->private_data; |
22a4f650 | 4740 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4741 | struct user_struct *user = current_user(); |
22a4f650 | 4742 | unsigned long locked, lock_limit; |
45bfb2e5 | 4743 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4744 | unsigned long vma_size; |
4745 | unsigned long nr_pages; | |
45bfb2e5 | 4746 | long user_extra = 0, extra = 0; |
d57e34fd | 4747 | int ret = 0, flags = 0; |
37d81828 | 4748 | |
c7920614 PZ |
4749 | /* |
4750 | * Don't allow mmap() of inherited per-task counters. This would | |
4751 | * create a performance issue due to all children writing to the | |
76369139 | 4752 | * same rb. |
c7920614 PZ |
4753 | */ |
4754 | if (event->cpu == -1 && event->attr.inherit) | |
4755 | return -EINVAL; | |
4756 | ||
43a21ea8 | 4757 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4758 | return -EINVAL; |
7b732a75 PZ |
4759 | |
4760 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4761 | |
4762 | if (vma->vm_pgoff == 0) { | |
4763 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4764 | } else { | |
4765 | /* | |
4766 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4767 | * mapped, all subsequent mappings should have the same size | |
4768 | * and offset. Must be above the normal perf buffer. | |
4769 | */ | |
4770 | u64 aux_offset, aux_size; | |
4771 | ||
4772 | if (!event->rb) | |
4773 | return -EINVAL; | |
4774 | ||
4775 | nr_pages = vma_size / PAGE_SIZE; | |
4776 | ||
4777 | mutex_lock(&event->mmap_mutex); | |
4778 | ret = -EINVAL; | |
4779 | ||
4780 | rb = event->rb; | |
4781 | if (!rb) | |
4782 | goto aux_unlock; | |
4783 | ||
4784 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4785 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4786 | ||
4787 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4788 | goto aux_unlock; | |
4789 | ||
4790 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4791 | goto aux_unlock; | |
4792 | ||
4793 | /* already mapped with a different offset */ | |
4794 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4795 | goto aux_unlock; | |
4796 | ||
4797 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4798 | goto aux_unlock; | |
4799 | ||
4800 | /* already mapped with a different size */ | |
4801 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4802 | goto aux_unlock; | |
4803 | ||
4804 | if (!is_power_of_2(nr_pages)) | |
4805 | goto aux_unlock; | |
4806 | ||
4807 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4808 | goto aux_unlock; | |
4809 | ||
4810 | if (rb_has_aux(rb)) { | |
4811 | atomic_inc(&rb->aux_mmap_count); | |
4812 | ret = 0; | |
4813 | goto unlock; | |
4814 | } | |
4815 | ||
4816 | atomic_set(&rb->aux_mmap_count, 1); | |
4817 | user_extra = nr_pages; | |
4818 | ||
4819 | goto accounting; | |
4820 | } | |
7b732a75 | 4821 | |
7730d865 | 4822 | /* |
76369139 | 4823 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4824 | * can do bitmasks instead of modulo. |
4825 | */ | |
2ed11312 | 4826 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4827 | return -EINVAL; |
4828 | ||
7b732a75 | 4829 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4830 | return -EINVAL; |
4831 | ||
cdd6c482 | 4832 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4833 | again: |
cdd6c482 | 4834 | mutex_lock(&event->mmap_mutex); |
76369139 | 4835 | if (event->rb) { |
9bb5d40c | 4836 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4837 | ret = -EINVAL; |
9bb5d40c PZ |
4838 | goto unlock; |
4839 | } | |
4840 | ||
4841 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4842 | /* | |
4843 | * Raced against perf_mmap_close() through | |
4844 | * perf_event_set_output(). Try again, hope for better | |
4845 | * luck. | |
4846 | */ | |
4847 | mutex_unlock(&event->mmap_mutex); | |
4848 | goto again; | |
4849 | } | |
4850 | ||
ebb3c4c4 PZ |
4851 | goto unlock; |
4852 | } | |
4853 | ||
789f90fc | 4854 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4855 | |
4856 | accounting: | |
cdd6c482 | 4857 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4858 | |
4859 | /* | |
4860 | * Increase the limit linearly with more CPUs: | |
4861 | */ | |
4862 | user_lock_limit *= num_online_cpus(); | |
4863 | ||
789f90fc | 4864 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4865 | |
789f90fc PZ |
4866 | if (user_locked > user_lock_limit) |
4867 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4868 | |
78d7d407 | 4869 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4870 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4871 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4872 | |
459ec28a IM |
4873 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4874 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4875 | ret = -EPERM; |
4876 | goto unlock; | |
4877 | } | |
7b732a75 | 4878 | |
45bfb2e5 | 4879 | WARN_ON(!rb && event->rb); |
906010b2 | 4880 | |
d57e34fd | 4881 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4882 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4883 | |
76369139 | 4884 | if (!rb) { |
45bfb2e5 PZ |
4885 | rb = rb_alloc(nr_pages, |
4886 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4887 | event->cpu, flags); | |
26cb63ad | 4888 | |
45bfb2e5 PZ |
4889 | if (!rb) { |
4890 | ret = -ENOMEM; | |
4891 | goto unlock; | |
4892 | } | |
43a21ea8 | 4893 | |
45bfb2e5 PZ |
4894 | atomic_set(&rb->mmap_count, 1); |
4895 | rb->mmap_user = get_current_user(); | |
4896 | rb->mmap_locked = extra; | |
26cb63ad | 4897 | |
45bfb2e5 | 4898 | ring_buffer_attach(event, rb); |
ac9721f3 | 4899 | |
45bfb2e5 PZ |
4900 | perf_event_init_userpage(event); |
4901 | perf_event_update_userpage(event); | |
4902 | } else { | |
1a594131 AS |
4903 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4904 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4905 | if (!ret) |
4906 | rb->aux_mmap_locked = extra; | |
4907 | } | |
9a0f05cb | 4908 | |
ebb3c4c4 | 4909 | unlock: |
45bfb2e5 PZ |
4910 | if (!ret) { |
4911 | atomic_long_add(user_extra, &user->locked_vm); | |
4912 | vma->vm_mm->pinned_vm += extra; | |
4913 | ||
ac9721f3 | 4914 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4915 | } else if (rb) { |
4916 | atomic_dec(&rb->mmap_count); | |
4917 | } | |
4918 | aux_unlock: | |
cdd6c482 | 4919 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4920 | |
9bb5d40c PZ |
4921 | /* |
4922 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4923 | * vma. | |
4924 | */ | |
26cb63ad | 4925 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4926 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4927 | |
1e0fb9ec AL |
4928 | if (event->pmu->event_mapped) |
4929 | event->pmu->event_mapped(event); | |
4930 | ||
7b732a75 | 4931 | return ret; |
37d81828 PM |
4932 | } |
4933 | ||
3c446b3d PZ |
4934 | static int perf_fasync(int fd, struct file *filp, int on) |
4935 | { | |
496ad9aa | 4936 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4937 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4938 | int retval; |
4939 | ||
5955102c | 4940 | inode_lock(inode); |
cdd6c482 | 4941 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 4942 | inode_unlock(inode); |
3c446b3d PZ |
4943 | |
4944 | if (retval < 0) | |
4945 | return retval; | |
4946 | ||
4947 | return 0; | |
4948 | } | |
4949 | ||
0793a61d | 4950 | static const struct file_operations perf_fops = { |
3326c1ce | 4951 | .llseek = no_llseek, |
0793a61d TG |
4952 | .release = perf_release, |
4953 | .read = perf_read, | |
4954 | .poll = perf_poll, | |
d859e29f | 4955 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4956 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4957 | .mmap = perf_mmap, |
3c446b3d | 4958 | .fasync = perf_fasync, |
0793a61d TG |
4959 | }; |
4960 | ||
925d519a | 4961 | /* |
cdd6c482 | 4962 | * Perf event wakeup |
925d519a PZ |
4963 | * |
4964 | * If there's data, ensure we set the poll() state and publish everything | |
4965 | * to user-space before waking everybody up. | |
4966 | */ | |
4967 | ||
fed66e2c PZ |
4968 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4969 | { | |
4970 | /* only the parent has fasync state */ | |
4971 | if (event->parent) | |
4972 | event = event->parent; | |
4973 | return &event->fasync; | |
4974 | } | |
4975 | ||
cdd6c482 | 4976 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4977 | { |
10c6db11 | 4978 | ring_buffer_wakeup(event); |
4c9e2542 | 4979 | |
cdd6c482 | 4980 | if (event->pending_kill) { |
fed66e2c | 4981 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4982 | event->pending_kill = 0; |
4c9e2542 | 4983 | } |
925d519a PZ |
4984 | } |
4985 | ||
e360adbe | 4986 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4987 | { |
cdd6c482 IM |
4988 | struct perf_event *event = container_of(entry, |
4989 | struct perf_event, pending); | |
d525211f PZ |
4990 | int rctx; |
4991 | ||
4992 | rctx = perf_swevent_get_recursion_context(); | |
4993 | /* | |
4994 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4995 | * and we won't recurse 'further'. | |
4996 | */ | |
79f14641 | 4997 | |
cdd6c482 IM |
4998 | if (event->pending_disable) { |
4999 | event->pending_disable = 0; | |
fae3fde6 | 5000 | perf_event_disable_local(event); |
79f14641 PZ |
5001 | } |
5002 | ||
cdd6c482 IM |
5003 | if (event->pending_wakeup) { |
5004 | event->pending_wakeup = 0; | |
5005 | perf_event_wakeup(event); | |
79f14641 | 5006 | } |
d525211f PZ |
5007 | |
5008 | if (rctx >= 0) | |
5009 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
5010 | } |
5011 | ||
39447b38 ZY |
5012 | /* |
5013 | * We assume there is only KVM supporting the callbacks. | |
5014 | * Later on, we might change it to a list if there is | |
5015 | * another virtualization implementation supporting the callbacks. | |
5016 | */ | |
5017 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
5018 | ||
5019 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5020 | { | |
5021 | perf_guest_cbs = cbs; | |
5022 | return 0; | |
5023 | } | |
5024 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
5025 | ||
5026 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5027 | { | |
5028 | perf_guest_cbs = NULL; | |
5029 | return 0; | |
5030 | } | |
5031 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5032 | ||
4018994f JO |
5033 | static void |
5034 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5035 | struct pt_regs *regs, u64 mask) | |
5036 | { | |
5037 | int bit; | |
5038 | ||
5039 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
5040 | sizeof(mask) * BITS_PER_BYTE) { | |
5041 | u64 val; | |
5042 | ||
5043 | val = perf_reg_value(regs, bit); | |
5044 | perf_output_put(handle, val); | |
5045 | } | |
5046 | } | |
5047 | ||
60e2364e | 5048 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5049 | struct pt_regs *regs, |
5050 | struct pt_regs *regs_user_copy) | |
4018994f | 5051 | { |
88a7c26a AL |
5052 | if (user_mode(regs)) { |
5053 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5054 | regs_user->regs = regs; |
88a7c26a AL |
5055 | } else if (current->mm) { |
5056 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5057 | } else { |
5058 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5059 | regs_user->regs = NULL; | |
4018994f JO |
5060 | } |
5061 | } | |
5062 | ||
60e2364e SE |
5063 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5064 | struct pt_regs *regs) | |
5065 | { | |
5066 | regs_intr->regs = regs; | |
5067 | regs_intr->abi = perf_reg_abi(current); | |
5068 | } | |
5069 | ||
5070 | ||
c5ebcedb JO |
5071 | /* |
5072 | * Get remaining task size from user stack pointer. | |
5073 | * | |
5074 | * It'd be better to take stack vma map and limit this more | |
5075 | * precisly, but there's no way to get it safely under interrupt, | |
5076 | * so using TASK_SIZE as limit. | |
5077 | */ | |
5078 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5079 | { | |
5080 | unsigned long addr = perf_user_stack_pointer(regs); | |
5081 | ||
5082 | if (!addr || addr >= TASK_SIZE) | |
5083 | return 0; | |
5084 | ||
5085 | return TASK_SIZE - addr; | |
5086 | } | |
5087 | ||
5088 | static u16 | |
5089 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5090 | struct pt_regs *regs) | |
5091 | { | |
5092 | u64 task_size; | |
5093 | ||
5094 | /* No regs, no stack pointer, no dump. */ | |
5095 | if (!regs) | |
5096 | return 0; | |
5097 | ||
5098 | /* | |
5099 | * Check if we fit in with the requested stack size into the: | |
5100 | * - TASK_SIZE | |
5101 | * If we don't, we limit the size to the TASK_SIZE. | |
5102 | * | |
5103 | * - remaining sample size | |
5104 | * If we don't, we customize the stack size to | |
5105 | * fit in to the remaining sample size. | |
5106 | */ | |
5107 | ||
5108 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5109 | stack_size = min(stack_size, (u16) task_size); | |
5110 | ||
5111 | /* Current header size plus static size and dynamic size. */ | |
5112 | header_size += 2 * sizeof(u64); | |
5113 | ||
5114 | /* Do we fit in with the current stack dump size? */ | |
5115 | if ((u16) (header_size + stack_size) < header_size) { | |
5116 | /* | |
5117 | * If we overflow the maximum size for the sample, | |
5118 | * we customize the stack dump size to fit in. | |
5119 | */ | |
5120 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5121 | stack_size = round_up(stack_size, sizeof(u64)); | |
5122 | } | |
5123 | ||
5124 | return stack_size; | |
5125 | } | |
5126 | ||
5127 | static void | |
5128 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5129 | struct pt_regs *regs) | |
5130 | { | |
5131 | /* Case of a kernel thread, nothing to dump */ | |
5132 | if (!regs) { | |
5133 | u64 size = 0; | |
5134 | perf_output_put(handle, size); | |
5135 | } else { | |
5136 | unsigned long sp; | |
5137 | unsigned int rem; | |
5138 | u64 dyn_size; | |
5139 | ||
5140 | /* | |
5141 | * We dump: | |
5142 | * static size | |
5143 | * - the size requested by user or the best one we can fit | |
5144 | * in to the sample max size | |
5145 | * data | |
5146 | * - user stack dump data | |
5147 | * dynamic size | |
5148 | * - the actual dumped size | |
5149 | */ | |
5150 | ||
5151 | /* Static size. */ | |
5152 | perf_output_put(handle, dump_size); | |
5153 | ||
5154 | /* Data. */ | |
5155 | sp = perf_user_stack_pointer(regs); | |
5156 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5157 | dyn_size = dump_size - rem; | |
5158 | ||
5159 | perf_output_skip(handle, rem); | |
5160 | ||
5161 | /* Dynamic size. */ | |
5162 | perf_output_put(handle, dyn_size); | |
5163 | } | |
5164 | } | |
5165 | ||
c980d109 ACM |
5166 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5167 | struct perf_sample_data *data, | |
5168 | struct perf_event *event) | |
6844c09d ACM |
5169 | { |
5170 | u64 sample_type = event->attr.sample_type; | |
5171 | ||
5172 | data->type = sample_type; | |
5173 | header->size += event->id_header_size; | |
5174 | ||
5175 | if (sample_type & PERF_SAMPLE_TID) { | |
5176 | /* namespace issues */ | |
5177 | data->tid_entry.pid = perf_event_pid(event, current); | |
5178 | data->tid_entry.tid = perf_event_tid(event, current); | |
5179 | } | |
5180 | ||
5181 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5182 | data->time = perf_event_clock(event); |
6844c09d | 5183 | |
ff3d527c | 5184 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5185 | data->id = primary_event_id(event); |
5186 | ||
5187 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5188 | data->stream_id = event->id; | |
5189 | ||
5190 | if (sample_type & PERF_SAMPLE_CPU) { | |
5191 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5192 | data->cpu_entry.reserved = 0; | |
5193 | } | |
5194 | } | |
5195 | ||
76369139 FW |
5196 | void perf_event_header__init_id(struct perf_event_header *header, |
5197 | struct perf_sample_data *data, | |
5198 | struct perf_event *event) | |
c980d109 ACM |
5199 | { |
5200 | if (event->attr.sample_id_all) | |
5201 | __perf_event_header__init_id(header, data, event); | |
5202 | } | |
5203 | ||
5204 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5205 | struct perf_sample_data *data) | |
5206 | { | |
5207 | u64 sample_type = data->type; | |
5208 | ||
5209 | if (sample_type & PERF_SAMPLE_TID) | |
5210 | perf_output_put(handle, data->tid_entry); | |
5211 | ||
5212 | if (sample_type & PERF_SAMPLE_TIME) | |
5213 | perf_output_put(handle, data->time); | |
5214 | ||
5215 | if (sample_type & PERF_SAMPLE_ID) | |
5216 | perf_output_put(handle, data->id); | |
5217 | ||
5218 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5219 | perf_output_put(handle, data->stream_id); | |
5220 | ||
5221 | if (sample_type & PERF_SAMPLE_CPU) | |
5222 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5223 | |
5224 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5225 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5226 | } |
5227 | ||
76369139 FW |
5228 | void perf_event__output_id_sample(struct perf_event *event, |
5229 | struct perf_output_handle *handle, | |
5230 | struct perf_sample_data *sample) | |
c980d109 ACM |
5231 | { |
5232 | if (event->attr.sample_id_all) | |
5233 | __perf_event__output_id_sample(handle, sample); | |
5234 | } | |
5235 | ||
3dab77fb | 5236 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5237 | struct perf_event *event, |
5238 | u64 enabled, u64 running) | |
3dab77fb | 5239 | { |
cdd6c482 | 5240 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5241 | u64 values[4]; |
5242 | int n = 0; | |
5243 | ||
b5e58793 | 5244 | values[n++] = perf_event_count(event); |
3dab77fb | 5245 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5246 | values[n++] = enabled + |
cdd6c482 | 5247 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5248 | } |
5249 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5250 | values[n++] = running + |
cdd6c482 | 5251 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5252 | } |
5253 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5254 | values[n++] = primary_event_id(event); |
3dab77fb | 5255 | |
76369139 | 5256 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5257 | } |
5258 | ||
5259 | /* | |
cdd6c482 | 5260 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5261 | */ |
5262 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5263 | struct perf_event *event, |
5264 | u64 enabled, u64 running) | |
3dab77fb | 5265 | { |
cdd6c482 IM |
5266 | struct perf_event *leader = event->group_leader, *sub; |
5267 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5268 | u64 values[5]; |
5269 | int n = 0; | |
5270 | ||
5271 | values[n++] = 1 + leader->nr_siblings; | |
5272 | ||
5273 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5274 | values[n++] = enabled; |
3dab77fb PZ |
5275 | |
5276 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5277 | values[n++] = running; |
3dab77fb | 5278 | |
cdd6c482 | 5279 | if (leader != event) |
3dab77fb PZ |
5280 | leader->pmu->read(leader); |
5281 | ||
b5e58793 | 5282 | values[n++] = perf_event_count(leader); |
3dab77fb | 5283 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5284 | values[n++] = primary_event_id(leader); |
3dab77fb | 5285 | |
76369139 | 5286 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5287 | |
65abc865 | 5288 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5289 | n = 0; |
5290 | ||
6f5ab001 JO |
5291 | if ((sub != event) && |
5292 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5293 | sub->pmu->read(sub); |
5294 | ||
b5e58793 | 5295 | values[n++] = perf_event_count(sub); |
3dab77fb | 5296 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5297 | values[n++] = primary_event_id(sub); |
3dab77fb | 5298 | |
76369139 | 5299 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5300 | } |
5301 | } | |
5302 | ||
eed01528 SE |
5303 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5304 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5305 | ||
3dab77fb | 5306 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5307 | struct perf_event *event) |
3dab77fb | 5308 | { |
e3f3541c | 5309 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5310 | u64 read_format = event->attr.read_format; |
5311 | ||
5312 | /* | |
5313 | * compute total_time_enabled, total_time_running | |
5314 | * based on snapshot values taken when the event | |
5315 | * was last scheduled in. | |
5316 | * | |
5317 | * we cannot simply called update_context_time() | |
5318 | * because of locking issue as we are called in | |
5319 | * NMI context | |
5320 | */ | |
c4794295 | 5321 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5322 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5323 | |
cdd6c482 | 5324 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5325 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5326 | else |
eed01528 | 5327 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5328 | } |
5329 | ||
5622f295 MM |
5330 | void perf_output_sample(struct perf_output_handle *handle, |
5331 | struct perf_event_header *header, | |
5332 | struct perf_sample_data *data, | |
cdd6c482 | 5333 | struct perf_event *event) |
5622f295 MM |
5334 | { |
5335 | u64 sample_type = data->type; | |
5336 | ||
5337 | perf_output_put(handle, *header); | |
5338 | ||
ff3d527c AH |
5339 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5340 | perf_output_put(handle, data->id); | |
5341 | ||
5622f295 MM |
5342 | if (sample_type & PERF_SAMPLE_IP) |
5343 | perf_output_put(handle, data->ip); | |
5344 | ||
5345 | if (sample_type & PERF_SAMPLE_TID) | |
5346 | perf_output_put(handle, data->tid_entry); | |
5347 | ||
5348 | if (sample_type & PERF_SAMPLE_TIME) | |
5349 | perf_output_put(handle, data->time); | |
5350 | ||
5351 | if (sample_type & PERF_SAMPLE_ADDR) | |
5352 | perf_output_put(handle, data->addr); | |
5353 | ||
5354 | if (sample_type & PERF_SAMPLE_ID) | |
5355 | perf_output_put(handle, data->id); | |
5356 | ||
5357 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5358 | perf_output_put(handle, data->stream_id); | |
5359 | ||
5360 | if (sample_type & PERF_SAMPLE_CPU) | |
5361 | perf_output_put(handle, data->cpu_entry); | |
5362 | ||
5363 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5364 | perf_output_put(handle, data->period); | |
5365 | ||
5366 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5367 | perf_output_read(handle, event); |
5622f295 MM |
5368 | |
5369 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5370 | if (data->callchain) { | |
5371 | int size = 1; | |
5372 | ||
5373 | if (data->callchain) | |
5374 | size += data->callchain->nr; | |
5375 | ||
5376 | size *= sizeof(u64); | |
5377 | ||
76369139 | 5378 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5379 | } else { |
5380 | u64 nr = 0; | |
5381 | perf_output_put(handle, nr); | |
5382 | } | |
5383 | } | |
5384 | ||
5385 | if (sample_type & PERF_SAMPLE_RAW) { | |
5386 | if (data->raw) { | |
fa128e6a AS |
5387 | u32 raw_size = data->raw->size; |
5388 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5389 | sizeof(u64)) - sizeof(u32); | |
5390 | u64 zero = 0; | |
5391 | ||
5392 | perf_output_put(handle, real_size); | |
5393 | __output_copy(handle, data->raw->data, raw_size); | |
5394 | if (real_size - raw_size) | |
5395 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5396 | } else { |
5397 | struct { | |
5398 | u32 size; | |
5399 | u32 data; | |
5400 | } raw = { | |
5401 | .size = sizeof(u32), | |
5402 | .data = 0, | |
5403 | }; | |
5404 | perf_output_put(handle, raw); | |
5405 | } | |
5406 | } | |
a7ac67ea | 5407 | |
bce38cd5 SE |
5408 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5409 | if (data->br_stack) { | |
5410 | size_t size; | |
5411 | ||
5412 | size = data->br_stack->nr | |
5413 | * sizeof(struct perf_branch_entry); | |
5414 | ||
5415 | perf_output_put(handle, data->br_stack->nr); | |
5416 | perf_output_copy(handle, data->br_stack->entries, size); | |
5417 | } else { | |
5418 | /* | |
5419 | * we always store at least the value of nr | |
5420 | */ | |
5421 | u64 nr = 0; | |
5422 | perf_output_put(handle, nr); | |
5423 | } | |
5424 | } | |
4018994f JO |
5425 | |
5426 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5427 | u64 abi = data->regs_user.abi; | |
5428 | ||
5429 | /* | |
5430 | * If there are no regs to dump, notice it through | |
5431 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5432 | */ | |
5433 | perf_output_put(handle, abi); | |
5434 | ||
5435 | if (abi) { | |
5436 | u64 mask = event->attr.sample_regs_user; | |
5437 | perf_output_sample_regs(handle, | |
5438 | data->regs_user.regs, | |
5439 | mask); | |
5440 | } | |
5441 | } | |
c5ebcedb | 5442 | |
a5cdd40c | 5443 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5444 | perf_output_sample_ustack(handle, |
5445 | data->stack_user_size, | |
5446 | data->regs_user.regs); | |
a5cdd40c | 5447 | } |
c3feedf2 AK |
5448 | |
5449 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5450 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5451 | |
5452 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5453 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5454 | |
fdfbbd07 AK |
5455 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5456 | perf_output_put(handle, data->txn); | |
5457 | ||
60e2364e SE |
5458 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5459 | u64 abi = data->regs_intr.abi; | |
5460 | /* | |
5461 | * If there are no regs to dump, notice it through | |
5462 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5463 | */ | |
5464 | perf_output_put(handle, abi); | |
5465 | ||
5466 | if (abi) { | |
5467 | u64 mask = event->attr.sample_regs_intr; | |
5468 | ||
5469 | perf_output_sample_regs(handle, | |
5470 | data->regs_intr.regs, | |
5471 | mask); | |
5472 | } | |
5473 | } | |
5474 | ||
a5cdd40c PZ |
5475 | if (!event->attr.watermark) { |
5476 | int wakeup_events = event->attr.wakeup_events; | |
5477 | ||
5478 | if (wakeup_events) { | |
5479 | struct ring_buffer *rb = handle->rb; | |
5480 | int events = local_inc_return(&rb->events); | |
5481 | ||
5482 | if (events >= wakeup_events) { | |
5483 | local_sub(wakeup_events, &rb->events); | |
5484 | local_inc(&rb->wakeup); | |
5485 | } | |
5486 | } | |
5487 | } | |
5622f295 MM |
5488 | } |
5489 | ||
5490 | void perf_prepare_sample(struct perf_event_header *header, | |
5491 | struct perf_sample_data *data, | |
cdd6c482 | 5492 | struct perf_event *event, |
5622f295 | 5493 | struct pt_regs *regs) |
7b732a75 | 5494 | { |
cdd6c482 | 5495 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5496 | |
cdd6c482 | 5497 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5498 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5499 | |
5500 | header->misc = 0; | |
5501 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5502 | |
c980d109 | 5503 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5504 | |
c320c7b7 | 5505 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5506 | data->ip = perf_instruction_pointer(regs); |
5507 | ||
b23f3325 | 5508 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5509 | int size = 1; |
394ee076 | 5510 | |
e6dab5ff | 5511 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5512 | |
5513 | if (data->callchain) | |
5514 | size += data->callchain->nr; | |
5515 | ||
5516 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5517 | } |
5518 | ||
3a43ce68 | 5519 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5520 | int size = sizeof(u32); |
5521 | ||
5522 | if (data->raw) | |
5523 | size += data->raw->size; | |
5524 | else | |
5525 | size += sizeof(u32); | |
5526 | ||
fa128e6a | 5527 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5528 | } |
bce38cd5 SE |
5529 | |
5530 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5531 | int size = sizeof(u64); /* nr */ | |
5532 | if (data->br_stack) { | |
5533 | size += data->br_stack->nr | |
5534 | * sizeof(struct perf_branch_entry); | |
5535 | } | |
5536 | header->size += size; | |
5537 | } | |
4018994f | 5538 | |
2565711f | 5539 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5540 | perf_sample_regs_user(&data->regs_user, regs, |
5541 | &data->regs_user_copy); | |
2565711f | 5542 | |
4018994f JO |
5543 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5544 | /* regs dump ABI info */ | |
5545 | int size = sizeof(u64); | |
5546 | ||
4018994f JO |
5547 | if (data->regs_user.regs) { |
5548 | u64 mask = event->attr.sample_regs_user; | |
5549 | size += hweight64(mask) * sizeof(u64); | |
5550 | } | |
5551 | ||
5552 | header->size += size; | |
5553 | } | |
c5ebcedb JO |
5554 | |
5555 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5556 | /* | |
5557 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5558 | * processed as the last one or have additional check added | |
5559 | * in case new sample type is added, because we could eat | |
5560 | * up the rest of the sample size. | |
5561 | */ | |
c5ebcedb JO |
5562 | u16 stack_size = event->attr.sample_stack_user; |
5563 | u16 size = sizeof(u64); | |
5564 | ||
c5ebcedb | 5565 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5566 | data->regs_user.regs); |
c5ebcedb JO |
5567 | |
5568 | /* | |
5569 | * If there is something to dump, add space for the dump | |
5570 | * itself and for the field that tells the dynamic size, | |
5571 | * which is how many have been actually dumped. | |
5572 | */ | |
5573 | if (stack_size) | |
5574 | size += sizeof(u64) + stack_size; | |
5575 | ||
5576 | data->stack_user_size = stack_size; | |
5577 | header->size += size; | |
5578 | } | |
60e2364e SE |
5579 | |
5580 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5581 | /* regs dump ABI info */ | |
5582 | int size = sizeof(u64); | |
5583 | ||
5584 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5585 | ||
5586 | if (data->regs_intr.regs) { | |
5587 | u64 mask = event->attr.sample_regs_intr; | |
5588 | ||
5589 | size += hweight64(mask) * sizeof(u64); | |
5590 | } | |
5591 | ||
5592 | header->size += size; | |
5593 | } | |
5622f295 | 5594 | } |
7f453c24 | 5595 | |
21509084 YZ |
5596 | void perf_event_output(struct perf_event *event, |
5597 | struct perf_sample_data *data, | |
5598 | struct pt_regs *regs) | |
5622f295 MM |
5599 | { |
5600 | struct perf_output_handle handle; | |
5601 | struct perf_event_header header; | |
689802b2 | 5602 | |
927c7a9e FW |
5603 | /* protect the callchain buffers */ |
5604 | rcu_read_lock(); | |
5605 | ||
cdd6c482 | 5606 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5607 | |
a7ac67ea | 5608 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5609 | goto exit; |
0322cd6e | 5610 | |
cdd6c482 | 5611 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5612 | |
8a057d84 | 5613 | perf_output_end(&handle); |
927c7a9e FW |
5614 | |
5615 | exit: | |
5616 | rcu_read_unlock(); | |
0322cd6e PZ |
5617 | } |
5618 | ||
38b200d6 | 5619 | /* |
cdd6c482 | 5620 | * read event_id |
38b200d6 PZ |
5621 | */ |
5622 | ||
5623 | struct perf_read_event { | |
5624 | struct perf_event_header header; | |
5625 | ||
5626 | u32 pid; | |
5627 | u32 tid; | |
38b200d6 PZ |
5628 | }; |
5629 | ||
5630 | static void | |
cdd6c482 | 5631 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5632 | struct task_struct *task) |
5633 | { | |
5634 | struct perf_output_handle handle; | |
c980d109 | 5635 | struct perf_sample_data sample; |
dfc65094 | 5636 | struct perf_read_event read_event = { |
38b200d6 | 5637 | .header = { |
cdd6c482 | 5638 | .type = PERF_RECORD_READ, |
38b200d6 | 5639 | .misc = 0, |
c320c7b7 | 5640 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5641 | }, |
cdd6c482 IM |
5642 | .pid = perf_event_pid(event, task), |
5643 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5644 | }; |
3dab77fb | 5645 | int ret; |
38b200d6 | 5646 | |
c980d109 | 5647 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5648 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5649 | if (ret) |
5650 | return; | |
5651 | ||
dfc65094 | 5652 | perf_output_put(&handle, read_event); |
cdd6c482 | 5653 | perf_output_read(&handle, event); |
c980d109 | 5654 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5655 | |
38b200d6 PZ |
5656 | perf_output_end(&handle); |
5657 | } | |
5658 | ||
52d857a8 JO |
5659 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5660 | ||
5661 | static void | |
5662 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5663 | perf_event_aux_output_cb output, |
5664 | void *data) | |
5665 | { | |
5666 | struct perf_event *event; | |
5667 | ||
5668 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5669 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5670 | continue; | |
5671 | if (!event_filter_match(event)) | |
5672 | continue; | |
67516844 | 5673 | output(event, data); |
52d857a8 JO |
5674 | } |
5675 | } | |
5676 | ||
4e93ad60 JO |
5677 | static void |
5678 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5679 | struct perf_event_context *task_ctx) | |
5680 | { | |
5681 | rcu_read_lock(); | |
5682 | preempt_disable(); | |
5683 | perf_event_aux_ctx(task_ctx, output, data); | |
5684 | preempt_enable(); | |
5685 | rcu_read_unlock(); | |
5686 | } | |
5687 | ||
52d857a8 | 5688 | static void |
67516844 | 5689 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5690 | struct perf_event_context *task_ctx) |
5691 | { | |
5692 | struct perf_cpu_context *cpuctx; | |
5693 | struct perf_event_context *ctx; | |
5694 | struct pmu *pmu; | |
5695 | int ctxn; | |
5696 | ||
4e93ad60 JO |
5697 | /* |
5698 | * If we have task_ctx != NULL we only notify | |
5699 | * the task context itself. The task_ctx is set | |
5700 | * only for EXIT events before releasing task | |
5701 | * context. | |
5702 | */ | |
5703 | if (task_ctx) { | |
5704 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5705 | return; | |
5706 | } | |
5707 | ||
52d857a8 JO |
5708 | rcu_read_lock(); |
5709 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5710 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5711 | if (cpuctx->unique_pmu != pmu) | |
5712 | goto next; | |
67516844 | 5713 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5714 | ctxn = pmu->task_ctx_nr; |
5715 | if (ctxn < 0) | |
5716 | goto next; | |
5717 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5718 | if (ctx) | |
67516844 | 5719 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5720 | next: |
5721 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5722 | } | |
52d857a8 JO |
5723 | rcu_read_unlock(); |
5724 | } | |
5725 | ||
60313ebe | 5726 | /* |
9f498cc5 PZ |
5727 | * task tracking -- fork/exit |
5728 | * | |
13d7a241 | 5729 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5730 | */ |
5731 | ||
9f498cc5 | 5732 | struct perf_task_event { |
3a80b4a3 | 5733 | struct task_struct *task; |
cdd6c482 | 5734 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5735 | |
5736 | struct { | |
5737 | struct perf_event_header header; | |
5738 | ||
5739 | u32 pid; | |
5740 | u32 ppid; | |
9f498cc5 PZ |
5741 | u32 tid; |
5742 | u32 ptid; | |
393b2ad8 | 5743 | u64 time; |
cdd6c482 | 5744 | } event_id; |
60313ebe PZ |
5745 | }; |
5746 | ||
67516844 JO |
5747 | static int perf_event_task_match(struct perf_event *event) |
5748 | { | |
13d7a241 SE |
5749 | return event->attr.comm || event->attr.mmap || |
5750 | event->attr.mmap2 || event->attr.mmap_data || | |
5751 | event->attr.task; | |
67516844 JO |
5752 | } |
5753 | ||
cdd6c482 | 5754 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5755 | void *data) |
60313ebe | 5756 | { |
52d857a8 | 5757 | struct perf_task_event *task_event = data; |
60313ebe | 5758 | struct perf_output_handle handle; |
c980d109 | 5759 | struct perf_sample_data sample; |
9f498cc5 | 5760 | struct task_struct *task = task_event->task; |
c980d109 | 5761 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5762 | |
67516844 JO |
5763 | if (!perf_event_task_match(event)) |
5764 | return; | |
5765 | ||
c980d109 | 5766 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5767 | |
c980d109 | 5768 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5769 | task_event->event_id.header.size); |
ef60777c | 5770 | if (ret) |
c980d109 | 5771 | goto out; |
60313ebe | 5772 | |
cdd6c482 IM |
5773 | task_event->event_id.pid = perf_event_pid(event, task); |
5774 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5775 | |
cdd6c482 IM |
5776 | task_event->event_id.tid = perf_event_tid(event, task); |
5777 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5778 | |
34f43927 PZ |
5779 | task_event->event_id.time = perf_event_clock(event); |
5780 | ||
cdd6c482 | 5781 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5782 | |
c980d109 ACM |
5783 | perf_event__output_id_sample(event, &handle, &sample); |
5784 | ||
60313ebe | 5785 | perf_output_end(&handle); |
c980d109 ACM |
5786 | out: |
5787 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5788 | } |
5789 | ||
cdd6c482 IM |
5790 | static void perf_event_task(struct task_struct *task, |
5791 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5792 | int new) |
60313ebe | 5793 | { |
9f498cc5 | 5794 | struct perf_task_event task_event; |
60313ebe | 5795 | |
cdd6c482 IM |
5796 | if (!atomic_read(&nr_comm_events) && |
5797 | !atomic_read(&nr_mmap_events) && | |
5798 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5799 | return; |
5800 | ||
9f498cc5 | 5801 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5802 | .task = task, |
5803 | .task_ctx = task_ctx, | |
cdd6c482 | 5804 | .event_id = { |
60313ebe | 5805 | .header = { |
cdd6c482 | 5806 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5807 | .misc = 0, |
cdd6c482 | 5808 | .size = sizeof(task_event.event_id), |
60313ebe | 5809 | }, |
573402db PZ |
5810 | /* .pid */ |
5811 | /* .ppid */ | |
9f498cc5 PZ |
5812 | /* .tid */ |
5813 | /* .ptid */ | |
34f43927 | 5814 | /* .time */ |
60313ebe PZ |
5815 | }, |
5816 | }; | |
5817 | ||
67516844 | 5818 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5819 | &task_event, |
5820 | task_ctx); | |
9f498cc5 PZ |
5821 | } |
5822 | ||
cdd6c482 | 5823 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5824 | { |
cdd6c482 | 5825 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5826 | } |
5827 | ||
8d1b2d93 PZ |
5828 | /* |
5829 | * comm tracking | |
5830 | */ | |
5831 | ||
5832 | struct perf_comm_event { | |
22a4f650 IM |
5833 | struct task_struct *task; |
5834 | char *comm; | |
8d1b2d93 PZ |
5835 | int comm_size; |
5836 | ||
5837 | struct { | |
5838 | struct perf_event_header header; | |
5839 | ||
5840 | u32 pid; | |
5841 | u32 tid; | |
cdd6c482 | 5842 | } event_id; |
8d1b2d93 PZ |
5843 | }; |
5844 | ||
67516844 JO |
5845 | static int perf_event_comm_match(struct perf_event *event) |
5846 | { | |
5847 | return event->attr.comm; | |
5848 | } | |
5849 | ||
cdd6c482 | 5850 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5851 | void *data) |
8d1b2d93 | 5852 | { |
52d857a8 | 5853 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5854 | struct perf_output_handle handle; |
c980d109 | 5855 | struct perf_sample_data sample; |
cdd6c482 | 5856 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5857 | int ret; |
5858 | ||
67516844 JO |
5859 | if (!perf_event_comm_match(event)) |
5860 | return; | |
5861 | ||
c980d109 ACM |
5862 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5863 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5864 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5865 | |
5866 | if (ret) | |
c980d109 | 5867 | goto out; |
8d1b2d93 | 5868 | |
cdd6c482 IM |
5869 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5870 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5871 | |
cdd6c482 | 5872 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5873 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5874 | comm_event->comm_size); |
c980d109 ACM |
5875 | |
5876 | perf_event__output_id_sample(event, &handle, &sample); | |
5877 | ||
8d1b2d93 | 5878 | perf_output_end(&handle); |
c980d109 ACM |
5879 | out: |
5880 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5881 | } |
5882 | ||
cdd6c482 | 5883 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5884 | { |
413ee3b4 | 5885 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5886 | unsigned int size; |
8d1b2d93 | 5887 | |
413ee3b4 | 5888 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5889 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5890 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5891 | |
5892 | comm_event->comm = comm; | |
5893 | comm_event->comm_size = size; | |
5894 | ||
cdd6c482 | 5895 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5896 | |
67516844 | 5897 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5898 | comm_event, |
5899 | NULL); | |
8d1b2d93 PZ |
5900 | } |
5901 | ||
82b89778 | 5902 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5903 | { |
9ee318a7 PZ |
5904 | struct perf_comm_event comm_event; |
5905 | ||
cdd6c482 | 5906 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5907 | return; |
a63eaf34 | 5908 | |
9ee318a7 | 5909 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5910 | .task = task, |
573402db PZ |
5911 | /* .comm */ |
5912 | /* .comm_size */ | |
cdd6c482 | 5913 | .event_id = { |
573402db | 5914 | .header = { |
cdd6c482 | 5915 | .type = PERF_RECORD_COMM, |
82b89778 | 5916 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5917 | /* .size */ |
5918 | }, | |
5919 | /* .pid */ | |
5920 | /* .tid */ | |
8d1b2d93 PZ |
5921 | }, |
5922 | }; | |
5923 | ||
cdd6c482 | 5924 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5925 | } |
5926 | ||
0a4a9391 PZ |
5927 | /* |
5928 | * mmap tracking | |
5929 | */ | |
5930 | ||
5931 | struct perf_mmap_event { | |
089dd79d PZ |
5932 | struct vm_area_struct *vma; |
5933 | ||
5934 | const char *file_name; | |
5935 | int file_size; | |
13d7a241 SE |
5936 | int maj, min; |
5937 | u64 ino; | |
5938 | u64 ino_generation; | |
f972eb63 | 5939 | u32 prot, flags; |
0a4a9391 PZ |
5940 | |
5941 | struct { | |
5942 | struct perf_event_header header; | |
5943 | ||
5944 | u32 pid; | |
5945 | u32 tid; | |
5946 | u64 start; | |
5947 | u64 len; | |
5948 | u64 pgoff; | |
cdd6c482 | 5949 | } event_id; |
0a4a9391 PZ |
5950 | }; |
5951 | ||
67516844 JO |
5952 | static int perf_event_mmap_match(struct perf_event *event, |
5953 | void *data) | |
5954 | { | |
5955 | struct perf_mmap_event *mmap_event = data; | |
5956 | struct vm_area_struct *vma = mmap_event->vma; | |
5957 | int executable = vma->vm_flags & VM_EXEC; | |
5958 | ||
5959 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5960 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5961 | } |
5962 | ||
cdd6c482 | 5963 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5964 | void *data) |
0a4a9391 | 5965 | { |
52d857a8 | 5966 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5967 | struct perf_output_handle handle; |
c980d109 | 5968 | struct perf_sample_data sample; |
cdd6c482 | 5969 | int size = mmap_event->event_id.header.size; |
c980d109 | 5970 | int ret; |
0a4a9391 | 5971 | |
67516844 JO |
5972 | if (!perf_event_mmap_match(event, data)) |
5973 | return; | |
5974 | ||
13d7a241 SE |
5975 | if (event->attr.mmap2) { |
5976 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5977 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5978 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5979 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5980 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5981 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5982 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5983 | } |
5984 | ||
c980d109 ACM |
5985 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5986 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5987 | mmap_event->event_id.header.size); |
0a4a9391 | 5988 | if (ret) |
c980d109 | 5989 | goto out; |
0a4a9391 | 5990 | |
cdd6c482 IM |
5991 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5992 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5993 | |
cdd6c482 | 5994 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5995 | |
5996 | if (event->attr.mmap2) { | |
5997 | perf_output_put(&handle, mmap_event->maj); | |
5998 | perf_output_put(&handle, mmap_event->min); | |
5999 | perf_output_put(&handle, mmap_event->ino); | |
6000 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
6001 | perf_output_put(&handle, mmap_event->prot); |
6002 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
6003 | } |
6004 | ||
76369139 | 6005 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 6006 | mmap_event->file_size); |
c980d109 ACM |
6007 | |
6008 | perf_event__output_id_sample(event, &handle, &sample); | |
6009 | ||
78d613eb | 6010 | perf_output_end(&handle); |
c980d109 ACM |
6011 | out: |
6012 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
6013 | } |
6014 | ||
cdd6c482 | 6015 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 6016 | { |
089dd79d PZ |
6017 | struct vm_area_struct *vma = mmap_event->vma; |
6018 | struct file *file = vma->vm_file; | |
13d7a241 SE |
6019 | int maj = 0, min = 0; |
6020 | u64 ino = 0, gen = 0; | |
f972eb63 | 6021 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
6022 | unsigned int size; |
6023 | char tmp[16]; | |
6024 | char *buf = NULL; | |
2c42cfbf | 6025 | char *name; |
413ee3b4 | 6026 | |
0a4a9391 | 6027 | if (file) { |
13d7a241 SE |
6028 | struct inode *inode; |
6029 | dev_t dev; | |
3ea2f2b9 | 6030 | |
2c42cfbf | 6031 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 6032 | if (!buf) { |
c7e548b4 ON |
6033 | name = "//enomem"; |
6034 | goto cpy_name; | |
0a4a9391 | 6035 | } |
413ee3b4 | 6036 | /* |
3ea2f2b9 | 6037 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
6038 | * need to add enough zero bytes after the string to handle |
6039 | * the 64bit alignment we do later. | |
6040 | */ | |
9bf39ab2 | 6041 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 6042 | if (IS_ERR(name)) { |
c7e548b4 ON |
6043 | name = "//toolong"; |
6044 | goto cpy_name; | |
0a4a9391 | 6045 | } |
13d7a241 SE |
6046 | inode = file_inode(vma->vm_file); |
6047 | dev = inode->i_sb->s_dev; | |
6048 | ino = inode->i_ino; | |
6049 | gen = inode->i_generation; | |
6050 | maj = MAJOR(dev); | |
6051 | min = MINOR(dev); | |
f972eb63 PZ |
6052 | |
6053 | if (vma->vm_flags & VM_READ) | |
6054 | prot |= PROT_READ; | |
6055 | if (vma->vm_flags & VM_WRITE) | |
6056 | prot |= PROT_WRITE; | |
6057 | if (vma->vm_flags & VM_EXEC) | |
6058 | prot |= PROT_EXEC; | |
6059 | ||
6060 | if (vma->vm_flags & VM_MAYSHARE) | |
6061 | flags = MAP_SHARED; | |
6062 | else | |
6063 | flags = MAP_PRIVATE; | |
6064 | ||
6065 | if (vma->vm_flags & VM_DENYWRITE) | |
6066 | flags |= MAP_DENYWRITE; | |
6067 | if (vma->vm_flags & VM_MAYEXEC) | |
6068 | flags |= MAP_EXECUTABLE; | |
6069 | if (vma->vm_flags & VM_LOCKED) | |
6070 | flags |= MAP_LOCKED; | |
6071 | if (vma->vm_flags & VM_HUGETLB) | |
6072 | flags |= MAP_HUGETLB; | |
6073 | ||
c7e548b4 | 6074 | goto got_name; |
0a4a9391 | 6075 | } else { |
fbe26abe JO |
6076 | if (vma->vm_ops && vma->vm_ops->name) { |
6077 | name = (char *) vma->vm_ops->name(vma); | |
6078 | if (name) | |
6079 | goto cpy_name; | |
6080 | } | |
6081 | ||
2c42cfbf | 6082 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6083 | if (name) |
6084 | goto cpy_name; | |
089dd79d | 6085 | |
32c5fb7e | 6086 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6087 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6088 | name = "[heap]"; |
6089 | goto cpy_name; | |
32c5fb7e ON |
6090 | } |
6091 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6092 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6093 | name = "[stack]"; |
6094 | goto cpy_name; | |
089dd79d PZ |
6095 | } |
6096 | ||
c7e548b4 ON |
6097 | name = "//anon"; |
6098 | goto cpy_name; | |
0a4a9391 PZ |
6099 | } |
6100 | ||
c7e548b4 ON |
6101 | cpy_name: |
6102 | strlcpy(tmp, name, sizeof(tmp)); | |
6103 | name = tmp; | |
0a4a9391 | 6104 | got_name: |
2c42cfbf PZ |
6105 | /* |
6106 | * Since our buffer works in 8 byte units we need to align our string | |
6107 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6108 | * zero'd out to avoid leaking random bits to userspace. | |
6109 | */ | |
6110 | size = strlen(name)+1; | |
6111 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6112 | name[size++] = '\0'; | |
0a4a9391 PZ |
6113 | |
6114 | mmap_event->file_name = name; | |
6115 | mmap_event->file_size = size; | |
13d7a241 SE |
6116 | mmap_event->maj = maj; |
6117 | mmap_event->min = min; | |
6118 | mmap_event->ino = ino; | |
6119 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6120 | mmap_event->prot = prot; |
6121 | mmap_event->flags = flags; | |
0a4a9391 | 6122 | |
2fe85427 SE |
6123 | if (!(vma->vm_flags & VM_EXEC)) |
6124 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6125 | ||
cdd6c482 | 6126 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6127 | |
67516844 | 6128 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6129 | mmap_event, |
6130 | NULL); | |
665c2142 | 6131 | |
0a4a9391 PZ |
6132 | kfree(buf); |
6133 | } | |
6134 | ||
3af9e859 | 6135 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6136 | { |
9ee318a7 PZ |
6137 | struct perf_mmap_event mmap_event; |
6138 | ||
cdd6c482 | 6139 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6140 | return; |
6141 | ||
6142 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6143 | .vma = vma, |
573402db PZ |
6144 | /* .file_name */ |
6145 | /* .file_size */ | |
cdd6c482 | 6146 | .event_id = { |
573402db | 6147 | .header = { |
cdd6c482 | 6148 | .type = PERF_RECORD_MMAP, |
39447b38 | 6149 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6150 | /* .size */ |
6151 | }, | |
6152 | /* .pid */ | |
6153 | /* .tid */ | |
089dd79d PZ |
6154 | .start = vma->vm_start, |
6155 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6156 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6157 | }, |
13d7a241 SE |
6158 | /* .maj (attr_mmap2 only) */ |
6159 | /* .min (attr_mmap2 only) */ | |
6160 | /* .ino (attr_mmap2 only) */ | |
6161 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6162 | /* .prot (attr_mmap2 only) */ |
6163 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6164 | }; |
6165 | ||
cdd6c482 | 6166 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6167 | } |
6168 | ||
68db7e98 AS |
6169 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6170 | unsigned long size, u64 flags) | |
6171 | { | |
6172 | struct perf_output_handle handle; | |
6173 | struct perf_sample_data sample; | |
6174 | struct perf_aux_event { | |
6175 | struct perf_event_header header; | |
6176 | u64 offset; | |
6177 | u64 size; | |
6178 | u64 flags; | |
6179 | } rec = { | |
6180 | .header = { | |
6181 | .type = PERF_RECORD_AUX, | |
6182 | .misc = 0, | |
6183 | .size = sizeof(rec), | |
6184 | }, | |
6185 | .offset = head, | |
6186 | .size = size, | |
6187 | .flags = flags, | |
6188 | }; | |
6189 | int ret; | |
6190 | ||
6191 | perf_event_header__init_id(&rec.header, &sample, event); | |
6192 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6193 | ||
6194 | if (ret) | |
6195 | return; | |
6196 | ||
6197 | perf_output_put(&handle, rec); | |
6198 | perf_event__output_id_sample(event, &handle, &sample); | |
6199 | ||
6200 | perf_output_end(&handle); | |
6201 | } | |
6202 | ||
f38b0dbb KL |
6203 | /* |
6204 | * Lost/dropped samples logging | |
6205 | */ | |
6206 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6207 | { | |
6208 | struct perf_output_handle handle; | |
6209 | struct perf_sample_data sample; | |
6210 | int ret; | |
6211 | ||
6212 | struct { | |
6213 | struct perf_event_header header; | |
6214 | u64 lost; | |
6215 | } lost_samples_event = { | |
6216 | .header = { | |
6217 | .type = PERF_RECORD_LOST_SAMPLES, | |
6218 | .misc = 0, | |
6219 | .size = sizeof(lost_samples_event), | |
6220 | }, | |
6221 | .lost = lost, | |
6222 | }; | |
6223 | ||
6224 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6225 | ||
6226 | ret = perf_output_begin(&handle, event, | |
6227 | lost_samples_event.header.size); | |
6228 | if (ret) | |
6229 | return; | |
6230 | ||
6231 | perf_output_put(&handle, lost_samples_event); | |
6232 | perf_event__output_id_sample(event, &handle, &sample); | |
6233 | perf_output_end(&handle); | |
6234 | } | |
6235 | ||
45ac1403 AH |
6236 | /* |
6237 | * context_switch tracking | |
6238 | */ | |
6239 | ||
6240 | struct perf_switch_event { | |
6241 | struct task_struct *task; | |
6242 | struct task_struct *next_prev; | |
6243 | ||
6244 | struct { | |
6245 | struct perf_event_header header; | |
6246 | u32 next_prev_pid; | |
6247 | u32 next_prev_tid; | |
6248 | } event_id; | |
6249 | }; | |
6250 | ||
6251 | static int perf_event_switch_match(struct perf_event *event) | |
6252 | { | |
6253 | return event->attr.context_switch; | |
6254 | } | |
6255 | ||
6256 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6257 | { | |
6258 | struct perf_switch_event *se = data; | |
6259 | struct perf_output_handle handle; | |
6260 | struct perf_sample_data sample; | |
6261 | int ret; | |
6262 | ||
6263 | if (!perf_event_switch_match(event)) | |
6264 | return; | |
6265 | ||
6266 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6267 | if (event->ctx->task) { | |
6268 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6269 | se->event_id.header.size = sizeof(se->event_id.header); | |
6270 | } else { | |
6271 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6272 | se->event_id.header.size = sizeof(se->event_id); | |
6273 | se->event_id.next_prev_pid = | |
6274 | perf_event_pid(event, se->next_prev); | |
6275 | se->event_id.next_prev_tid = | |
6276 | perf_event_tid(event, se->next_prev); | |
6277 | } | |
6278 | ||
6279 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6280 | ||
6281 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6282 | if (ret) | |
6283 | return; | |
6284 | ||
6285 | if (event->ctx->task) | |
6286 | perf_output_put(&handle, se->event_id.header); | |
6287 | else | |
6288 | perf_output_put(&handle, se->event_id); | |
6289 | ||
6290 | perf_event__output_id_sample(event, &handle, &sample); | |
6291 | ||
6292 | perf_output_end(&handle); | |
6293 | } | |
6294 | ||
6295 | static void perf_event_switch(struct task_struct *task, | |
6296 | struct task_struct *next_prev, bool sched_in) | |
6297 | { | |
6298 | struct perf_switch_event switch_event; | |
6299 | ||
6300 | /* N.B. caller checks nr_switch_events != 0 */ | |
6301 | ||
6302 | switch_event = (struct perf_switch_event){ | |
6303 | .task = task, | |
6304 | .next_prev = next_prev, | |
6305 | .event_id = { | |
6306 | .header = { | |
6307 | /* .type */ | |
6308 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6309 | /* .size */ | |
6310 | }, | |
6311 | /* .next_prev_pid */ | |
6312 | /* .next_prev_tid */ | |
6313 | }, | |
6314 | }; | |
6315 | ||
6316 | perf_event_aux(perf_event_switch_output, | |
6317 | &switch_event, | |
6318 | NULL); | |
6319 | } | |
6320 | ||
a78ac325 PZ |
6321 | /* |
6322 | * IRQ throttle logging | |
6323 | */ | |
6324 | ||
cdd6c482 | 6325 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6326 | { |
6327 | struct perf_output_handle handle; | |
c980d109 | 6328 | struct perf_sample_data sample; |
a78ac325 PZ |
6329 | int ret; |
6330 | ||
6331 | struct { | |
6332 | struct perf_event_header header; | |
6333 | u64 time; | |
cca3f454 | 6334 | u64 id; |
7f453c24 | 6335 | u64 stream_id; |
a78ac325 PZ |
6336 | } throttle_event = { |
6337 | .header = { | |
cdd6c482 | 6338 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6339 | .misc = 0, |
6340 | .size = sizeof(throttle_event), | |
6341 | }, | |
34f43927 | 6342 | .time = perf_event_clock(event), |
cdd6c482 IM |
6343 | .id = primary_event_id(event), |
6344 | .stream_id = event->id, | |
a78ac325 PZ |
6345 | }; |
6346 | ||
966ee4d6 | 6347 | if (enable) |
cdd6c482 | 6348 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6349 | |
c980d109 ACM |
6350 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6351 | ||
6352 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6353 | throttle_event.header.size); |
a78ac325 PZ |
6354 | if (ret) |
6355 | return; | |
6356 | ||
6357 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6358 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6359 | perf_output_end(&handle); |
6360 | } | |
6361 | ||
ec0d7729 AS |
6362 | static void perf_log_itrace_start(struct perf_event *event) |
6363 | { | |
6364 | struct perf_output_handle handle; | |
6365 | struct perf_sample_data sample; | |
6366 | struct perf_aux_event { | |
6367 | struct perf_event_header header; | |
6368 | u32 pid; | |
6369 | u32 tid; | |
6370 | } rec; | |
6371 | int ret; | |
6372 | ||
6373 | if (event->parent) | |
6374 | event = event->parent; | |
6375 | ||
6376 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6377 | event->hw.itrace_started) | |
6378 | return; | |
6379 | ||
ec0d7729 AS |
6380 | rec.header.type = PERF_RECORD_ITRACE_START; |
6381 | rec.header.misc = 0; | |
6382 | rec.header.size = sizeof(rec); | |
6383 | rec.pid = perf_event_pid(event, current); | |
6384 | rec.tid = perf_event_tid(event, current); | |
6385 | ||
6386 | perf_event_header__init_id(&rec.header, &sample, event); | |
6387 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6388 | ||
6389 | if (ret) | |
6390 | return; | |
6391 | ||
6392 | perf_output_put(&handle, rec); | |
6393 | perf_event__output_id_sample(event, &handle, &sample); | |
6394 | ||
6395 | perf_output_end(&handle); | |
6396 | } | |
6397 | ||
f6c7d5fe | 6398 | /* |
cdd6c482 | 6399 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6400 | */ |
6401 | ||
a8b0ca17 | 6402 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6403 | int throttle, struct perf_sample_data *data, |
6404 | struct pt_regs *regs) | |
f6c7d5fe | 6405 | { |
cdd6c482 IM |
6406 | int events = atomic_read(&event->event_limit); |
6407 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6408 | u64 seq; |
79f14641 PZ |
6409 | int ret = 0; |
6410 | ||
96398826 PZ |
6411 | /* |
6412 | * Non-sampling counters might still use the PMI to fold short | |
6413 | * hardware counters, ignore those. | |
6414 | */ | |
6415 | if (unlikely(!is_sampling_event(event))) | |
6416 | return 0; | |
6417 | ||
e050e3f0 SE |
6418 | seq = __this_cpu_read(perf_throttled_seq); |
6419 | if (seq != hwc->interrupts_seq) { | |
6420 | hwc->interrupts_seq = seq; | |
6421 | hwc->interrupts = 1; | |
6422 | } else { | |
6423 | hwc->interrupts++; | |
6424 | if (unlikely(throttle | |
6425 | && hwc->interrupts >= max_samples_per_tick)) { | |
6426 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6427 | hwc->interrupts = MAX_INTERRUPTS; |
6428 | perf_log_throttle(event, 0); | |
d84153d6 | 6429 | tick_nohz_full_kick(); |
a78ac325 PZ |
6430 | ret = 1; |
6431 | } | |
e050e3f0 | 6432 | } |
60db5e09 | 6433 | |
cdd6c482 | 6434 | if (event->attr.freq) { |
def0a9b2 | 6435 | u64 now = perf_clock(); |
abd50713 | 6436 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6437 | |
abd50713 | 6438 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6439 | |
abd50713 | 6440 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6441 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6442 | } |
6443 | ||
2023b359 PZ |
6444 | /* |
6445 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6446 | * events |
2023b359 PZ |
6447 | */ |
6448 | ||
cdd6c482 IM |
6449 | event->pending_kill = POLL_IN; |
6450 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6451 | ret = 1; |
cdd6c482 | 6452 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6453 | event->pending_disable = 1; |
6454 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6455 | } |
6456 | ||
453f19ee | 6457 | if (event->overflow_handler) |
a8b0ca17 | 6458 | event->overflow_handler(event, data, regs); |
453f19ee | 6459 | else |
a8b0ca17 | 6460 | perf_event_output(event, data, regs); |
453f19ee | 6461 | |
fed66e2c | 6462 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6463 | event->pending_wakeup = 1; |
6464 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6465 | } |
6466 | ||
79f14641 | 6467 | return ret; |
f6c7d5fe PZ |
6468 | } |
6469 | ||
a8b0ca17 | 6470 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6471 | struct perf_sample_data *data, |
6472 | struct pt_regs *regs) | |
850bc73f | 6473 | { |
a8b0ca17 | 6474 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6475 | } |
6476 | ||
15dbf27c | 6477 | /* |
cdd6c482 | 6478 | * Generic software event infrastructure |
15dbf27c PZ |
6479 | */ |
6480 | ||
b28ab83c PZ |
6481 | struct swevent_htable { |
6482 | struct swevent_hlist *swevent_hlist; | |
6483 | struct mutex hlist_mutex; | |
6484 | int hlist_refcount; | |
6485 | ||
6486 | /* Recursion avoidance in each contexts */ | |
6487 | int recursion[PERF_NR_CONTEXTS]; | |
6488 | }; | |
6489 | ||
6490 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6491 | ||
7b4b6658 | 6492 | /* |
cdd6c482 IM |
6493 | * We directly increment event->count and keep a second value in |
6494 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6495 | * is kept in the range [-sample_period, 0] so that we can use the |
6496 | * sign as trigger. | |
6497 | */ | |
6498 | ||
ab573844 | 6499 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6500 | { |
cdd6c482 | 6501 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6502 | u64 period = hwc->last_period; |
6503 | u64 nr, offset; | |
6504 | s64 old, val; | |
6505 | ||
6506 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6507 | |
6508 | again: | |
e7850595 | 6509 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6510 | if (val < 0) |
6511 | return 0; | |
15dbf27c | 6512 | |
7b4b6658 PZ |
6513 | nr = div64_u64(period + val, period); |
6514 | offset = nr * period; | |
6515 | val -= offset; | |
e7850595 | 6516 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6517 | goto again; |
15dbf27c | 6518 | |
7b4b6658 | 6519 | return nr; |
15dbf27c PZ |
6520 | } |
6521 | ||
0cff784a | 6522 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6523 | struct perf_sample_data *data, |
5622f295 | 6524 | struct pt_regs *regs) |
15dbf27c | 6525 | { |
cdd6c482 | 6526 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6527 | int throttle = 0; |
15dbf27c | 6528 | |
0cff784a PZ |
6529 | if (!overflow) |
6530 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6531 | |
7b4b6658 PZ |
6532 | if (hwc->interrupts == MAX_INTERRUPTS) |
6533 | return; | |
15dbf27c | 6534 | |
7b4b6658 | 6535 | for (; overflow; overflow--) { |
a8b0ca17 | 6536 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6537 | data, regs)) { |
7b4b6658 PZ |
6538 | /* |
6539 | * We inhibit the overflow from happening when | |
6540 | * hwc->interrupts == MAX_INTERRUPTS. | |
6541 | */ | |
6542 | break; | |
6543 | } | |
cf450a73 | 6544 | throttle = 1; |
7b4b6658 | 6545 | } |
15dbf27c PZ |
6546 | } |
6547 | ||
a4eaf7f1 | 6548 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6549 | struct perf_sample_data *data, |
5622f295 | 6550 | struct pt_regs *regs) |
7b4b6658 | 6551 | { |
cdd6c482 | 6552 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6553 | |
e7850595 | 6554 | local64_add(nr, &event->count); |
d6d020e9 | 6555 | |
0cff784a PZ |
6556 | if (!regs) |
6557 | return; | |
6558 | ||
6c7e550f | 6559 | if (!is_sampling_event(event)) |
7b4b6658 | 6560 | return; |
d6d020e9 | 6561 | |
5d81e5cf AV |
6562 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6563 | data->period = nr; | |
6564 | return perf_swevent_overflow(event, 1, data, regs); | |
6565 | } else | |
6566 | data->period = event->hw.last_period; | |
6567 | ||
0cff784a | 6568 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6569 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6570 | |
e7850595 | 6571 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6572 | return; |
df1a132b | 6573 | |
a8b0ca17 | 6574 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6575 | } |
6576 | ||
f5ffe02e FW |
6577 | static int perf_exclude_event(struct perf_event *event, |
6578 | struct pt_regs *regs) | |
6579 | { | |
a4eaf7f1 | 6580 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6581 | return 1; |
a4eaf7f1 | 6582 | |
f5ffe02e FW |
6583 | if (regs) { |
6584 | if (event->attr.exclude_user && user_mode(regs)) | |
6585 | return 1; | |
6586 | ||
6587 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6588 | return 1; | |
6589 | } | |
6590 | ||
6591 | return 0; | |
6592 | } | |
6593 | ||
cdd6c482 | 6594 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6595 | enum perf_type_id type, |
6fb2915d LZ |
6596 | u32 event_id, |
6597 | struct perf_sample_data *data, | |
6598 | struct pt_regs *regs) | |
15dbf27c | 6599 | { |
cdd6c482 | 6600 | if (event->attr.type != type) |
a21ca2ca | 6601 | return 0; |
f5ffe02e | 6602 | |
cdd6c482 | 6603 | if (event->attr.config != event_id) |
15dbf27c PZ |
6604 | return 0; |
6605 | ||
f5ffe02e FW |
6606 | if (perf_exclude_event(event, regs)) |
6607 | return 0; | |
15dbf27c PZ |
6608 | |
6609 | return 1; | |
6610 | } | |
6611 | ||
76e1d904 FW |
6612 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6613 | { | |
6614 | u64 val = event_id | (type << 32); | |
6615 | ||
6616 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6617 | } | |
6618 | ||
49f135ed FW |
6619 | static inline struct hlist_head * |
6620 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6621 | { |
49f135ed FW |
6622 | u64 hash = swevent_hash(type, event_id); |
6623 | ||
6624 | return &hlist->heads[hash]; | |
6625 | } | |
76e1d904 | 6626 | |
49f135ed FW |
6627 | /* For the read side: events when they trigger */ |
6628 | static inline struct hlist_head * | |
b28ab83c | 6629 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6630 | { |
6631 | struct swevent_hlist *hlist; | |
76e1d904 | 6632 | |
b28ab83c | 6633 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6634 | if (!hlist) |
6635 | return NULL; | |
6636 | ||
49f135ed FW |
6637 | return __find_swevent_head(hlist, type, event_id); |
6638 | } | |
6639 | ||
6640 | /* For the event head insertion and removal in the hlist */ | |
6641 | static inline struct hlist_head * | |
b28ab83c | 6642 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6643 | { |
6644 | struct swevent_hlist *hlist; | |
6645 | u32 event_id = event->attr.config; | |
6646 | u64 type = event->attr.type; | |
6647 | ||
6648 | /* | |
6649 | * Event scheduling is always serialized against hlist allocation | |
6650 | * and release. Which makes the protected version suitable here. | |
6651 | * The context lock guarantees that. | |
6652 | */ | |
b28ab83c | 6653 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6654 | lockdep_is_held(&event->ctx->lock)); |
6655 | if (!hlist) | |
6656 | return NULL; | |
6657 | ||
6658 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6659 | } |
6660 | ||
6661 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6662 | u64 nr, |
76e1d904 FW |
6663 | struct perf_sample_data *data, |
6664 | struct pt_regs *regs) | |
15dbf27c | 6665 | { |
4a32fea9 | 6666 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6667 | struct perf_event *event; |
76e1d904 | 6668 | struct hlist_head *head; |
15dbf27c | 6669 | |
76e1d904 | 6670 | rcu_read_lock(); |
b28ab83c | 6671 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6672 | if (!head) |
6673 | goto end; | |
6674 | ||
b67bfe0d | 6675 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6676 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6677 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6678 | } |
76e1d904 FW |
6679 | end: |
6680 | rcu_read_unlock(); | |
15dbf27c PZ |
6681 | } |
6682 | ||
86038c5e PZI |
6683 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6684 | ||
4ed7c92d | 6685 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6686 | { |
4a32fea9 | 6687 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6688 | |
b28ab83c | 6689 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6690 | } |
645e8cc0 | 6691 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6692 | |
fa9f90be | 6693 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6694 | { |
4a32fea9 | 6695 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6696 | |
b28ab83c | 6697 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6698 | } |
15dbf27c | 6699 | |
86038c5e | 6700 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6701 | { |
a4234bfc | 6702 | struct perf_sample_data data; |
4ed7c92d | 6703 | |
86038c5e | 6704 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6705 | return; |
a4234bfc | 6706 | |
fd0d000b | 6707 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6708 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6709 | } |
6710 | ||
6711 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6712 | { | |
6713 | int rctx; | |
6714 | ||
6715 | preempt_disable_notrace(); | |
6716 | rctx = perf_swevent_get_recursion_context(); | |
6717 | if (unlikely(rctx < 0)) | |
6718 | goto fail; | |
6719 | ||
6720 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6721 | |
6722 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6723 | fail: |
1c024eca | 6724 | preempt_enable_notrace(); |
b8e83514 PZ |
6725 | } |
6726 | ||
cdd6c482 | 6727 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6728 | { |
15dbf27c PZ |
6729 | } |
6730 | ||
a4eaf7f1 | 6731 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6732 | { |
4a32fea9 | 6733 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6734 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6735 | struct hlist_head *head; |
6736 | ||
6c7e550f | 6737 | if (is_sampling_event(event)) { |
7b4b6658 | 6738 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6739 | perf_swevent_set_period(event); |
7b4b6658 | 6740 | } |
76e1d904 | 6741 | |
a4eaf7f1 PZ |
6742 | hwc->state = !(flags & PERF_EF_START); |
6743 | ||
b28ab83c | 6744 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6745 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6746 | return -EINVAL; |
6747 | ||
6748 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6749 | perf_event_update_userpage(event); |
76e1d904 | 6750 | |
15dbf27c PZ |
6751 | return 0; |
6752 | } | |
6753 | ||
a4eaf7f1 | 6754 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6755 | { |
76e1d904 | 6756 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6757 | } |
6758 | ||
a4eaf7f1 | 6759 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6760 | { |
a4eaf7f1 | 6761 | event->hw.state = 0; |
d6d020e9 | 6762 | } |
aa9c4c0f | 6763 | |
a4eaf7f1 | 6764 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6765 | { |
a4eaf7f1 | 6766 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6767 | } |
6768 | ||
49f135ed FW |
6769 | /* Deref the hlist from the update side */ |
6770 | static inline struct swevent_hlist * | |
b28ab83c | 6771 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6772 | { |
b28ab83c PZ |
6773 | return rcu_dereference_protected(swhash->swevent_hlist, |
6774 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6775 | } |
6776 | ||
b28ab83c | 6777 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6778 | { |
b28ab83c | 6779 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6780 | |
49f135ed | 6781 | if (!hlist) |
76e1d904 FW |
6782 | return; |
6783 | ||
70691d4a | 6784 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6785 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6786 | } |
6787 | ||
3b364d7b | 6788 | static void swevent_hlist_put_cpu(int cpu) |
76e1d904 | 6789 | { |
b28ab83c | 6790 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6791 | |
b28ab83c | 6792 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6793 | |
b28ab83c PZ |
6794 | if (!--swhash->hlist_refcount) |
6795 | swevent_hlist_release(swhash); | |
76e1d904 | 6796 | |
b28ab83c | 6797 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6798 | } |
6799 | ||
3b364d7b | 6800 | static void swevent_hlist_put(void) |
76e1d904 FW |
6801 | { |
6802 | int cpu; | |
6803 | ||
76e1d904 | 6804 | for_each_possible_cpu(cpu) |
3b364d7b | 6805 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
6806 | } |
6807 | ||
3b364d7b | 6808 | static int swevent_hlist_get_cpu(int cpu) |
76e1d904 | 6809 | { |
b28ab83c | 6810 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6811 | int err = 0; |
6812 | ||
b28ab83c | 6813 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6814 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6815 | struct swevent_hlist *hlist; |
6816 | ||
6817 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6818 | if (!hlist) { | |
6819 | err = -ENOMEM; | |
6820 | goto exit; | |
6821 | } | |
b28ab83c | 6822 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6823 | } |
b28ab83c | 6824 | swhash->hlist_refcount++; |
9ed6060d | 6825 | exit: |
b28ab83c | 6826 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6827 | |
6828 | return err; | |
6829 | } | |
6830 | ||
3b364d7b | 6831 | static int swevent_hlist_get(void) |
76e1d904 | 6832 | { |
3b364d7b | 6833 | int err, cpu, failed_cpu; |
76e1d904 | 6834 | |
76e1d904 FW |
6835 | get_online_cpus(); |
6836 | for_each_possible_cpu(cpu) { | |
3b364d7b | 6837 | err = swevent_hlist_get_cpu(cpu); |
76e1d904 FW |
6838 | if (err) { |
6839 | failed_cpu = cpu; | |
6840 | goto fail; | |
6841 | } | |
6842 | } | |
6843 | put_online_cpus(); | |
6844 | ||
6845 | return 0; | |
9ed6060d | 6846 | fail: |
76e1d904 FW |
6847 | for_each_possible_cpu(cpu) { |
6848 | if (cpu == failed_cpu) | |
6849 | break; | |
3b364d7b | 6850 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
6851 | } |
6852 | ||
6853 | put_online_cpus(); | |
6854 | return err; | |
6855 | } | |
6856 | ||
c5905afb | 6857 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6858 | |
b0a873eb PZ |
6859 | static void sw_perf_event_destroy(struct perf_event *event) |
6860 | { | |
6861 | u64 event_id = event->attr.config; | |
95476b64 | 6862 | |
b0a873eb PZ |
6863 | WARN_ON(event->parent); |
6864 | ||
c5905afb | 6865 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
3b364d7b | 6866 | swevent_hlist_put(); |
b0a873eb PZ |
6867 | } |
6868 | ||
6869 | static int perf_swevent_init(struct perf_event *event) | |
6870 | { | |
8176cced | 6871 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6872 | |
6873 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6874 | return -ENOENT; | |
6875 | ||
2481c5fa SE |
6876 | /* |
6877 | * no branch sampling for software events | |
6878 | */ | |
6879 | if (has_branch_stack(event)) | |
6880 | return -EOPNOTSUPP; | |
6881 | ||
b0a873eb PZ |
6882 | switch (event_id) { |
6883 | case PERF_COUNT_SW_CPU_CLOCK: | |
6884 | case PERF_COUNT_SW_TASK_CLOCK: | |
6885 | return -ENOENT; | |
6886 | ||
6887 | default: | |
6888 | break; | |
6889 | } | |
6890 | ||
ce677831 | 6891 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6892 | return -ENOENT; |
6893 | ||
6894 | if (!event->parent) { | |
6895 | int err; | |
6896 | ||
3b364d7b | 6897 | err = swevent_hlist_get(); |
b0a873eb PZ |
6898 | if (err) |
6899 | return err; | |
6900 | ||
c5905afb | 6901 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6902 | event->destroy = sw_perf_event_destroy; |
6903 | } | |
6904 | ||
6905 | return 0; | |
6906 | } | |
6907 | ||
6908 | static struct pmu perf_swevent = { | |
89a1e187 | 6909 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6910 | |
34f43927 PZ |
6911 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6912 | ||
b0a873eb | 6913 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6914 | .add = perf_swevent_add, |
6915 | .del = perf_swevent_del, | |
6916 | .start = perf_swevent_start, | |
6917 | .stop = perf_swevent_stop, | |
1c024eca | 6918 | .read = perf_swevent_read, |
1c024eca PZ |
6919 | }; |
6920 | ||
b0a873eb PZ |
6921 | #ifdef CONFIG_EVENT_TRACING |
6922 | ||
1c024eca PZ |
6923 | static int perf_tp_filter_match(struct perf_event *event, |
6924 | struct perf_sample_data *data) | |
6925 | { | |
6926 | void *record = data->raw->data; | |
6927 | ||
b71b437e PZ |
6928 | /* only top level events have filters set */ |
6929 | if (event->parent) | |
6930 | event = event->parent; | |
6931 | ||
1c024eca PZ |
6932 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6933 | return 1; | |
6934 | return 0; | |
6935 | } | |
6936 | ||
6937 | static int perf_tp_event_match(struct perf_event *event, | |
6938 | struct perf_sample_data *data, | |
6939 | struct pt_regs *regs) | |
6940 | { | |
a0f7d0f7 FW |
6941 | if (event->hw.state & PERF_HES_STOPPED) |
6942 | return 0; | |
580d607c PZ |
6943 | /* |
6944 | * All tracepoints are from kernel-space. | |
6945 | */ | |
6946 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6947 | return 0; |
6948 | ||
6949 | if (!perf_tp_filter_match(event, data)) | |
6950 | return 0; | |
6951 | ||
6952 | return 1; | |
6953 | } | |
6954 | ||
6955 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6956 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6957 | struct task_struct *task) | |
95476b64 FW |
6958 | { |
6959 | struct perf_sample_data data; | |
1c024eca | 6960 | struct perf_event *event; |
1c024eca | 6961 | |
95476b64 FW |
6962 | struct perf_raw_record raw = { |
6963 | .size = entry_size, | |
6964 | .data = record, | |
6965 | }; | |
6966 | ||
fd0d000b | 6967 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6968 | data.raw = &raw; |
6969 | ||
b67bfe0d | 6970 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6971 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6972 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6973 | } |
ecc55f84 | 6974 | |
e6dab5ff AV |
6975 | /* |
6976 | * If we got specified a target task, also iterate its context and | |
6977 | * deliver this event there too. | |
6978 | */ | |
6979 | if (task && task != current) { | |
6980 | struct perf_event_context *ctx; | |
6981 | struct trace_entry *entry = record; | |
6982 | ||
6983 | rcu_read_lock(); | |
6984 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6985 | if (!ctx) | |
6986 | goto unlock; | |
6987 | ||
6988 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6989 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6990 | continue; | |
6991 | if (event->attr.config != entry->type) | |
6992 | continue; | |
6993 | if (perf_tp_event_match(event, &data, regs)) | |
6994 | perf_swevent_event(event, count, &data, regs); | |
6995 | } | |
6996 | unlock: | |
6997 | rcu_read_unlock(); | |
6998 | } | |
6999 | ||
ecc55f84 | 7000 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
7001 | } |
7002 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
7003 | ||
cdd6c482 | 7004 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 7005 | { |
1c024eca | 7006 | perf_trace_destroy(event); |
e077df4f PZ |
7007 | } |
7008 | ||
b0a873eb | 7009 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 7010 | { |
76e1d904 FW |
7011 | int err; |
7012 | ||
b0a873eb PZ |
7013 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
7014 | return -ENOENT; | |
7015 | ||
2481c5fa SE |
7016 | /* |
7017 | * no branch sampling for tracepoint events | |
7018 | */ | |
7019 | if (has_branch_stack(event)) | |
7020 | return -EOPNOTSUPP; | |
7021 | ||
1c024eca PZ |
7022 | err = perf_trace_init(event); |
7023 | if (err) | |
b0a873eb | 7024 | return err; |
e077df4f | 7025 | |
cdd6c482 | 7026 | event->destroy = tp_perf_event_destroy; |
e077df4f | 7027 | |
b0a873eb PZ |
7028 | return 0; |
7029 | } | |
7030 | ||
7031 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
7032 | .task_ctx_nr = perf_sw_context, |
7033 | ||
b0a873eb | 7034 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
7035 | .add = perf_trace_add, |
7036 | .del = perf_trace_del, | |
7037 | .start = perf_swevent_start, | |
7038 | .stop = perf_swevent_stop, | |
b0a873eb | 7039 | .read = perf_swevent_read, |
b0a873eb PZ |
7040 | }; |
7041 | ||
7042 | static inline void perf_tp_register(void) | |
7043 | { | |
2e80a82a | 7044 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 7045 | } |
6fb2915d LZ |
7046 | |
7047 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7048 | { | |
7049 | char *filter_str; | |
7050 | int ret; | |
7051 | ||
7052 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7053 | return -EINVAL; | |
7054 | ||
7055 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7056 | if (IS_ERR(filter_str)) | |
7057 | return PTR_ERR(filter_str); | |
7058 | ||
7059 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
7060 | ||
7061 | kfree(filter_str); | |
7062 | return ret; | |
7063 | } | |
7064 | ||
7065 | static void perf_event_free_filter(struct perf_event *event) | |
7066 | { | |
7067 | ftrace_profile_free_filter(event); | |
7068 | } | |
7069 | ||
2541517c AS |
7070 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7071 | { | |
7072 | struct bpf_prog *prog; | |
7073 | ||
7074 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7075 | return -EINVAL; | |
7076 | ||
7077 | if (event->tp_event->prog) | |
7078 | return -EEXIST; | |
7079 | ||
04a22fae WN |
7080 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7081 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7082 | return -EINVAL; |
7083 | ||
7084 | prog = bpf_prog_get(prog_fd); | |
7085 | if (IS_ERR(prog)) | |
7086 | return PTR_ERR(prog); | |
7087 | ||
6c373ca8 | 7088 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7089 | /* valid fd, but invalid bpf program type */ |
7090 | bpf_prog_put(prog); | |
7091 | return -EINVAL; | |
7092 | } | |
7093 | ||
7094 | event->tp_event->prog = prog; | |
7095 | ||
7096 | return 0; | |
7097 | } | |
7098 | ||
7099 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7100 | { | |
7101 | struct bpf_prog *prog; | |
7102 | ||
7103 | if (!event->tp_event) | |
7104 | return; | |
7105 | ||
7106 | prog = event->tp_event->prog; | |
7107 | if (prog) { | |
7108 | event->tp_event->prog = NULL; | |
7109 | bpf_prog_put(prog); | |
7110 | } | |
7111 | } | |
7112 | ||
e077df4f | 7113 | #else |
6fb2915d | 7114 | |
b0a873eb | 7115 | static inline void perf_tp_register(void) |
e077df4f | 7116 | { |
e077df4f | 7117 | } |
6fb2915d LZ |
7118 | |
7119 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7120 | { | |
7121 | return -ENOENT; | |
7122 | } | |
7123 | ||
7124 | static void perf_event_free_filter(struct perf_event *event) | |
7125 | { | |
7126 | } | |
7127 | ||
2541517c AS |
7128 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7129 | { | |
7130 | return -ENOENT; | |
7131 | } | |
7132 | ||
7133 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7134 | { | |
7135 | } | |
07b139c8 | 7136 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7137 | |
24f1e32c | 7138 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7139 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7140 | { |
f5ffe02e FW |
7141 | struct perf_sample_data sample; |
7142 | struct pt_regs *regs = data; | |
7143 | ||
fd0d000b | 7144 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7145 | |
a4eaf7f1 | 7146 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7147 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7148 | } |
7149 | #endif | |
7150 | ||
b0a873eb PZ |
7151 | /* |
7152 | * hrtimer based swevent callback | |
7153 | */ | |
f29ac756 | 7154 | |
b0a873eb | 7155 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7156 | { |
b0a873eb PZ |
7157 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7158 | struct perf_sample_data data; | |
7159 | struct pt_regs *regs; | |
7160 | struct perf_event *event; | |
7161 | u64 period; | |
f29ac756 | 7162 | |
b0a873eb | 7163 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7164 | |
7165 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7166 | return HRTIMER_NORESTART; | |
7167 | ||
b0a873eb | 7168 | event->pmu->read(event); |
f344011c | 7169 | |
fd0d000b | 7170 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7171 | regs = get_irq_regs(); |
7172 | ||
7173 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7174 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7175 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7176 | ret = HRTIMER_NORESTART; |
7177 | } | |
24f1e32c | 7178 | |
b0a873eb PZ |
7179 | period = max_t(u64, 10000, event->hw.sample_period); |
7180 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7181 | |
b0a873eb | 7182 | return ret; |
f29ac756 PZ |
7183 | } |
7184 | ||
b0a873eb | 7185 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7186 | { |
b0a873eb | 7187 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7188 | s64 period; |
7189 | ||
7190 | if (!is_sampling_event(event)) | |
7191 | return; | |
f5ffe02e | 7192 | |
5d508e82 FBH |
7193 | period = local64_read(&hwc->period_left); |
7194 | if (period) { | |
7195 | if (period < 0) | |
7196 | period = 10000; | |
fa407f35 | 7197 | |
5d508e82 FBH |
7198 | local64_set(&hwc->period_left, 0); |
7199 | } else { | |
7200 | period = max_t(u64, 10000, hwc->sample_period); | |
7201 | } | |
3497d206 TG |
7202 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7203 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7204 | } |
b0a873eb PZ |
7205 | |
7206 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7207 | { |
b0a873eb PZ |
7208 | struct hw_perf_event *hwc = &event->hw; |
7209 | ||
6c7e550f | 7210 | if (is_sampling_event(event)) { |
b0a873eb | 7211 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7212 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7213 | |
7214 | hrtimer_cancel(&hwc->hrtimer); | |
7215 | } | |
24f1e32c FW |
7216 | } |
7217 | ||
ba3dd36c PZ |
7218 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7219 | { | |
7220 | struct hw_perf_event *hwc = &event->hw; | |
7221 | ||
7222 | if (!is_sampling_event(event)) | |
7223 | return; | |
7224 | ||
7225 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7226 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7227 | ||
7228 | /* | |
7229 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7230 | * mapping and avoid the whole period adjust feedback stuff. | |
7231 | */ | |
7232 | if (event->attr.freq) { | |
7233 | long freq = event->attr.sample_freq; | |
7234 | ||
7235 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7236 | hwc->sample_period = event->attr.sample_period; | |
7237 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7238 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7239 | event->attr.freq = 0; |
7240 | } | |
7241 | } | |
7242 | ||
b0a873eb PZ |
7243 | /* |
7244 | * Software event: cpu wall time clock | |
7245 | */ | |
7246 | ||
7247 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7248 | { |
b0a873eb PZ |
7249 | s64 prev; |
7250 | u64 now; | |
7251 | ||
a4eaf7f1 | 7252 | now = local_clock(); |
b0a873eb PZ |
7253 | prev = local64_xchg(&event->hw.prev_count, now); |
7254 | local64_add(now - prev, &event->count); | |
24f1e32c | 7255 | } |
24f1e32c | 7256 | |
a4eaf7f1 | 7257 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7258 | { |
a4eaf7f1 | 7259 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7260 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7261 | } |
7262 | ||
a4eaf7f1 | 7263 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7264 | { |
b0a873eb PZ |
7265 | perf_swevent_cancel_hrtimer(event); |
7266 | cpu_clock_event_update(event); | |
7267 | } | |
f29ac756 | 7268 | |
a4eaf7f1 PZ |
7269 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7270 | { | |
7271 | if (flags & PERF_EF_START) | |
7272 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7273 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7274 | |
7275 | return 0; | |
7276 | } | |
7277 | ||
7278 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7279 | { | |
7280 | cpu_clock_event_stop(event, flags); | |
7281 | } | |
7282 | ||
b0a873eb PZ |
7283 | static void cpu_clock_event_read(struct perf_event *event) |
7284 | { | |
7285 | cpu_clock_event_update(event); | |
7286 | } | |
f344011c | 7287 | |
b0a873eb PZ |
7288 | static int cpu_clock_event_init(struct perf_event *event) |
7289 | { | |
7290 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7291 | return -ENOENT; | |
7292 | ||
7293 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7294 | return -ENOENT; | |
7295 | ||
2481c5fa SE |
7296 | /* |
7297 | * no branch sampling for software events | |
7298 | */ | |
7299 | if (has_branch_stack(event)) | |
7300 | return -EOPNOTSUPP; | |
7301 | ||
ba3dd36c PZ |
7302 | perf_swevent_init_hrtimer(event); |
7303 | ||
b0a873eb | 7304 | return 0; |
f29ac756 PZ |
7305 | } |
7306 | ||
b0a873eb | 7307 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7308 | .task_ctx_nr = perf_sw_context, |
7309 | ||
34f43927 PZ |
7310 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7311 | ||
b0a873eb | 7312 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7313 | .add = cpu_clock_event_add, |
7314 | .del = cpu_clock_event_del, | |
7315 | .start = cpu_clock_event_start, | |
7316 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7317 | .read = cpu_clock_event_read, |
7318 | }; | |
7319 | ||
7320 | /* | |
7321 | * Software event: task time clock | |
7322 | */ | |
7323 | ||
7324 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7325 | { |
b0a873eb PZ |
7326 | u64 prev; |
7327 | s64 delta; | |
5c92d124 | 7328 | |
b0a873eb PZ |
7329 | prev = local64_xchg(&event->hw.prev_count, now); |
7330 | delta = now - prev; | |
7331 | local64_add(delta, &event->count); | |
7332 | } | |
5c92d124 | 7333 | |
a4eaf7f1 | 7334 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7335 | { |
a4eaf7f1 | 7336 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7337 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7338 | } |
7339 | ||
a4eaf7f1 | 7340 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7341 | { |
7342 | perf_swevent_cancel_hrtimer(event); | |
7343 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7344 | } |
7345 | ||
7346 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7347 | { | |
7348 | if (flags & PERF_EF_START) | |
7349 | task_clock_event_start(event, flags); | |
6a694a60 | 7350 | perf_event_update_userpage(event); |
b0a873eb | 7351 | |
a4eaf7f1 PZ |
7352 | return 0; |
7353 | } | |
7354 | ||
7355 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7356 | { | |
7357 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7358 | } |
7359 | ||
7360 | static void task_clock_event_read(struct perf_event *event) | |
7361 | { | |
768a06e2 PZ |
7362 | u64 now = perf_clock(); |
7363 | u64 delta = now - event->ctx->timestamp; | |
7364 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7365 | |
7366 | task_clock_event_update(event, time); | |
7367 | } | |
7368 | ||
7369 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7370 | { |
b0a873eb PZ |
7371 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7372 | return -ENOENT; | |
7373 | ||
7374 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7375 | return -ENOENT; | |
7376 | ||
2481c5fa SE |
7377 | /* |
7378 | * no branch sampling for software events | |
7379 | */ | |
7380 | if (has_branch_stack(event)) | |
7381 | return -EOPNOTSUPP; | |
7382 | ||
ba3dd36c PZ |
7383 | perf_swevent_init_hrtimer(event); |
7384 | ||
b0a873eb | 7385 | return 0; |
6fb2915d LZ |
7386 | } |
7387 | ||
b0a873eb | 7388 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7389 | .task_ctx_nr = perf_sw_context, |
7390 | ||
34f43927 PZ |
7391 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7392 | ||
b0a873eb | 7393 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7394 | .add = task_clock_event_add, |
7395 | .del = task_clock_event_del, | |
7396 | .start = task_clock_event_start, | |
7397 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7398 | .read = task_clock_event_read, |
7399 | }; | |
6fb2915d | 7400 | |
ad5133b7 | 7401 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7402 | { |
e077df4f | 7403 | } |
6fb2915d | 7404 | |
fbbe0701 SB |
7405 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7406 | { | |
7407 | } | |
7408 | ||
ad5133b7 | 7409 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7410 | { |
ad5133b7 | 7411 | return 0; |
6fb2915d LZ |
7412 | } |
7413 | ||
18ab2cd3 | 7414 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7415 | |
7416 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7417 | { |
fbbe0701 SB |
7418 | __this_cpu_write(nop_txn_flags, flags); |
7419 | ||
7420 | if (flags & ~PERF_PMU_TXN_ADD) | |
7421 | return; | |
7422 | ||
ad5133b7 | 7423 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7424 | } |
7425 | ||
ad5133b7 PZ |
7426 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7427 | { | |
fbbe0701 SB |
7428 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7429 | ||
7430 | __this_cpu_write(nop_txn_flags, 0); | |
7431 | ||
7432 | if (flags & ~PERF_PMU_TXN_ADD) | |
7433 | return 0; | |
7434 | ||
ad5133b7 PZ |
7435 | perf_pmu_enable(pmu); |
7436 | return 0; | |
7437 | } | |
e077df4f | 7438 | |
ad5133b7 | 7439 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7440 | { |
fbbe0701 SB |
7441 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7442 | ||
7443 | __this_cpu_write(nop_txn_flags, 0); | |
7444 | ||
7445 | if (flags & ~PERF_PMU_TXN_ADD) | |
7446 | return; | |
7447 | ||
ad5133b7 | 7448 | perf_pmu_enable(pmu); |
24f1e32c FW |
7449 | } |
7450 | ||
35edc2a5 PZ |
7451 | static int perf_event_idx_default(struct perf_event *event) |
7452 | { | |
c719f560 | 7453 | return 0; |
35edc2a5 PZ |
7454 | } |
7455 | ||
8dc85d54 PZ |
7456 | /* |
7457 | * Ensures all contexts with the same task_ctx_nr have the same | |
7458 | * pmu_cpu_context too. | |
7459 | */ | |
9e317041 | 7460 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7461 | { |
8dc85d54 | 7462 | struct pmu *pmu; |
b326e956 | 7463 | |
8dc85d54 PZ |
7464 | if (ctxn < 0) |
7465 | return NULL; | |
24f1e32c | 7466 | |
8dc85d54 PZ |
7467 | list_for_each_entry(pmu, &pmus, entry) { |
7468 | if (pmu->task_ctx_nr == ctxn) | |
7469 | return pmu->pmu_cpu_context; | |
7470 | } | |
24f1e32c | 7471 | |
8dc85d54 | 7472 | return NULL; |
24f1e32c FW |
7473 | } |
7474 | ||
51676957 | 7475 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7476 | { |
51676957 PZ |
7477 | int cpu; |
7478 | ||
7479 | for_each_possible_cpu(cpu) { | |
7480 | struct perf_cpu_context *cpuctx; | |
7481 | ||
7482 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7483 | ||
3f1f3320 PZ |
7484 | if (cpuctx->unique_pmu == old_pmu) |
7485 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7486 | } |
7487 | } | |
7488 | ||
7489 | static void free_pmu_context(struct pmu *pmu) | |
7490 | { | |
7491 | struct pmu *i; | |
f5ffe02e | 7492 | |
8dc85d54 | 7493 | mutex_lock(&pmus_lock); |
0475f9ea | 7494 | /* |
8dc85d54 | 7495 | * Like a real lame refcount. |
0475f9ea | 7496 | */ |
51676957 PZ |
7497 | list_for_each_entry(i, &pmus, entry) { |
7498 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7499 | update_pmu_context(i, pmu); | |
8dc85d54 | 7500 | goto out; |
51676957 | 7501 | } |
8dc85d54 | 7502 | } |
d6d020e9 | 7503 | |
51676957 | 7504 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7505 | out: |
7506 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7507 | } |
2e80a82a | 7508 | static struct idr pmu_idr; |
d6d020e9 | 7509 | |
abe43400 PZ |
7510 | static ssize_t |
7511 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7512 | { | |
7513 | struct pmu *pmu = dev_get_drvdata(dev); | |
7514 | ||
7515 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7516 | } | |
90826ca7 | 7517 | static DEVICE_ATTR_RO(type); |
abe43400 | 7518 | |
62b85639 SE |
7519 | static ssize_t |
7520 | perf_event_mux_interval_ms_show(struct device *dev, | |
7521 | struct device_attribute *attr, | |
7522 | char *page) | |
7523 | { | |
7524 | struct pmu *pmu = dev_get_drvdata(dev); | |
7525 | ||
7526 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7527 | } | |
7528 | ||
272325c4 PZ |
7529 | static DEFINE_MUTEX(mux_interval_mutex); |
7530 | ||
62b85639 SE |
7531 | static ssize_t |
7532 | perf_event_mux_interval_ms_store(struct device *dev, | |
7533 | struct device_attribute *attr, | |
7534 | const char *buf, size_t count) | |
7535 | { | |
7536 | struct pmu *pmu = dev_get_drvdata(dev); | |
7537 | int timer, cpu, ret; | |
7538 | ||
7539 | ret = kstrtoint(buf, 0, &timer); | |
7540 | if (ret) | |
7541 | return ret; | |
7542 | ||
7543 | if (timer < 1) | |
7544 | return -EINVAL; | |
7545 | ||
7546 | /* same value, noting to do */ | |
7547 | if (timer == pmu->hrtimer_interval_ms) | |
7548 | return count; | |
7549 | ||
272325c4 | 7550 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7551 | pmu->hrtimer_interval_ms = timer; |
7552 | ||
7553 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7554 | get_online_cpus(); |
7555 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7556 | struct perf_cpu_context *cpuctx; |
7557 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7558 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7559 | ||
272325c4 PZ |
7560 | cpu_function_call(cpu, |
7561 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7562 | } |
272325c4 PZ |
7563 | put_online_cpus(); |
7564 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7565 | |
7566 | return count; | |
7567 | } | |
90826ca7 | 7568 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7569 | |
90826ca7 GKH |
7570 | static struct attribute *pmu_dev_attrs[] = { |
7571 | &dev_attr_type.attr, | |
7572 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7573 | NULL, | |
abe43400 | 7574 | }; |
90826ca7 | 7575 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7576 | |
7577 | static int pmu_bus_running; | |
7578 | static struct bus_type pmu_bus = { | |
7579 | .name = "event_source", | |
90826ca7 | 7580 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7581 | }; |
7582 | ||
7583 | static void pmu_dev_release(struct device *dev) | |
7584 | { | |
7585 | kfree(dev); | |
7586 | } | |
7587 | ||
7588 | static int pmu_dev_alloc(struct pmu *pmu) | |
7589 | { | |
7590 | int ret = -ENOMEM; | |
7591 | ||
7592 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7593 | if (!pmu->dev) | |
7594 | goto out; | |
7595 | ||
0c9d42ed | 7596 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7597 | device_initialize(pmu->dev); |
7598 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7599 | if (ret) | |
7600 | goto free_dev; | |
7601 | ||
7602 | dev_set_drvdata(pmu->dev, pmu); | |
7603 | pmu->dev->bus = &pmu_bus; | |
7604 | pmu->dev->release = pmu_dev_release; | |
7605 | ret = device_add(pmu->dev); | |
7606 | if (ret) | |
7607 | goto free_dev; | |
7608 | ||
7609 | out: | |
7610 | return ret; | |
7611 | ||
7612 | free_dev: | |
7613 | put_device(pmu->dev); | |
7614 | goto out; | |
7615 | } | |
7616 | ||
547e9fd7 | 7617 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7618 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7619 | |
03d8e80b | 7620 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7621 | { |
108b02cf | 7622 | int cpu, ret; |
24f1e32c | 7623 | |
b0a873eb | 7624 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7625 | ret = -ENOMEM; |
7626 | pmu->pmu_disable_count = alloc_percpu(int); | |
7627 | if (!pmu->pmu_disable_count) | |
7628 | goto unlock; | |
f29ac756 | 7629 | |
2e80a82a PZ |
7630 | pmu->type = -1; |
7631 | if (!name) | |
7632 | goto skip_type; | |
7633 | pmu->name = name; | |
7634 | ||
7635 | if (type < 0) { | |
0e9c3be2 TH |
7636 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7637 | if (type < 0) { | |
7638 | ret = type; | |
2e80a82a PZ |
7639 | goto free_pdc; |
7640 | } | |
7641 | } | |
7642 | pmu->type = type; | |
7643 | ||
abe43400 PZ |
7644 | if (pmu_bus_running) { |
7645 | ret = pmu_dev_alloc(pmu); | |
7646 | if (ret) | |
7647 | goto free_idr; | |
7648 | } | |
7649 | ||
2e80a82a | 7650 | skip_type: |
8dc85d54 PZ |
7651 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7652 | if (pmu->pmu_cpu_context) | |
7653 | goto got_cpu_context; | |
f29ac756 | 7654 | |
c4814202 | 7655 | ret = -ENOMEM; |
108b02cf PZ |
7656 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7657 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7658 | goto free_dev; |
f344011c | 7659 | |
108b02cf PZ |
7660 | for_each_possible_cpu(cpu) { |
7661 | struct perf_cpu_context *cpuctx; | |
7662 | ||
7663 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7664 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7665 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7666 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7667 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7668 | |
272325c4 | 7669 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7670 | |
3f1f3320 | 7671 | cpuctx->unique_pmu = pmu; |
108b02cf | 7672 | } |
76e1d904 | 7673 | |
8dc85d54 | 7674 | got_cpu_context: |
ad5133b7 PZ |
7675 | if (!pmu->start_txn) { |
7676 | if (pmu->pmu_enable) { | |
7677 | /* | |
7678 | * If we have pmu_enable/pmu_disable calls, install | |
7679 | * transaction stubs that use that to try and batch | |
7680 | * hardware accesses. | |
7681 | */ | |
7682 | pmu->start_txn = perf_pmu_start_txn; | |
7683 | pmu->commit_txn = perf_pmu_commit_txn; | |
7684 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7685 | } else { | |
fbbe0701 | 7686 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7687 | pmu->commit_txn = perf_pmu_nop_int; |
7688 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7689 | } |
5c92d124 | 7690 | } |
15dbf27c | 7691 | |
ad5133b7 PZ |
7692 | if (!pmu->pmu_enable) { |
7693 | pmu->pmu_enable = perf_pmu_nop_void; | |
7694 | pmu->pmu_disable = perf_pmu_nop_void; | |
7695 | } | |
7696 | ||
35edc2a5 PZ |
7697 | if (!pmu->event_idx) |
7698 | pmu->event_idx = perf_event_idx_default; | |
7699 | ||
b0a873eb | 7700 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7701 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7702 | ret = 0; |
7703 | unlock: | |
b0a873eb PZ |
7704 | mutex_unlock(&pmus_lock); |
7705 | ||
33696fc0 | 7706 | return ret; |
108b02cf | 7707 | |
abe43400 PZ |
7708 | free_dev: |
7709 | device_del(pmu->dev); | |
7710 | put_device(pmu->dev); | |
7711 | ||
2e80a82a PZ |
7712 | free_idr: |
7713 | if (pmu->type >= PERF_TYPE_MAX) | |
7714 | idr_remove(&pmu_idr, pmu->type); | |
7715 | ||
108b02cf PZ |
7716 | free_pdc: |
7717 | free_percpu(pmu->pmu_disable_count); | |
7718 | goto unlock; | |
f29ac756 | 7719 | } |
c464c76e | 7720 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7721 | |
b0a873eb | 7722 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7723 | { |
b0a873eb PZ |
7724 | mutex_lock(&pmus_lock); |
7725 | list_del_rcu(&pmu->entry); | |
7726 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7727 | |
0475f9ea | 7728 | /* |
cde8e884 PZ |
7729 | * We dereference the pmu list under both SRCU and regular RCU, so |
7730 | * synchronize against both of those. | |
0475f9ea | 7731 | */ |
b0a873eb | 7732 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7733 | synchronize_rcu(); |
d6d020e9 | 7734 | |
33696fc0 | 7735 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7736 | if (pmu->type >= PERF_TYPE_MAX) |
7737 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7738 | device_del(pmu->dev); |
7739 | put_device(pmu->dev); | |
51676957 | 7740 | free_pmu_context(pmu); |
b0a873eb | 7741 | } |
c464c76e | 7742 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7743 | |
cc34b98b MR |
7744 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7745 | { | |
ccd41c86 | 7746 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7747 | int ret; |
7748 | ||
7749 | if (!try_module_get(pmu->module)) | |
7750 | return -ENODEV; | |
ccd41c86 PZ |
7751 | |
7752 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7753 | /* |
7754 | * This ctx->mutex can nest when we're called through | |
7755 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7756 | */ | |
7757 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7758 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7759 | BUG_ON(!ctx); |
7760 | } | |
7761 | ||
cc34b98b MR |
7762 | event->pmu = pmu; |
7763 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7764 | |
7765 | if (ctx) | |
7766 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7767 | ||
cc34b98b MR |
7768 | if (ret) |
7769 | module_put(pmu->module); | |
7770 | ||
7771 | return ret; | |
7772 | } | |
7773 | ||
18ab2cd3 | 7774 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7775 | { |
7776 | struct pmu *pmu = NULL; | |
7777 | int idx; | |
940c5b29 | 7778 | int ret; |
b0a873eb PZ |
7779 | |
7780 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7781 | |
7782 | rcu_read_lock(); | |
7783 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7784 | rcu_read_unlock(); | |
940c5b29 | 7785 | if (pmu) { |
cc34b98b | 7786 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7787 | if (ret) |
7788 | pmu = ERR_PTR(ret); | |
2e80a82a | 7789 | goto unlock; |
940c5b29 | 7790 | } |
2e80a82a | 7791 | |
b0a873eb | 7792 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7793 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7794 | if (!ret) |
e5f4d339 | 7795 | goto unlock; |
76e1d904 | 7796 | |
b0a873eb PZ |
7797 | if (ret != -ENOENT) { |
7798 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7799 | goto unlock; |
f344011c | 7800 | } |
5c92d124 | 7801 | } |
e5f4d339 PZ |
7802 | pmu = ERR_PTR(-ENOENT); |
7803 | unlock: | |
b0a873eb | 7804 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7805 | |
4aeb0b42 | 7806 | return pmu; |
5c92d124 IM |
7807 | } |
7808 | ||
4beb31f3 FW |
7809 | static void account_event_cpu(struct perf_event *event, int cpu) |
7810 | { | |
7811 | if (event->parent) | |
7812 | return; | |
7813 | ||
4beb31f3 FW |
7814 | if (is_cgroup_event(event)) |
7815 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7816 | } | |
7817 | ||
766d6c07 FW |
7818 | static void account_event(struct perf_event *event) |
7819 | { | |
25432ae9 PZ |
7820 | bool inc = false; |
7821 | ||
4beb31f3 FW |
7822 | if (event->parent) |
7823 | return; | |
7824 | ||
766d6c07 | 7825 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7826 | inc = true; |
766d6c07 FW |
7827 | if (event->attr.mmap || event->attr.mmap_data) |
7828 | atomic_inc(&nr_mmap_events); | |
7829 | if (event->attr.comm) | |
7830 | atomic_inc(&nr_comm_events); | |
7831 | if (event->attr.task) | |
7832 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7833 | if (event->attr.freq) { |
7834 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7835 | tick_nohz_full_kick_all(); | |
7836 | } | |
45ac1403 AH |
7837 | if (event->attr.context_switch) { |
7838 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7839 | inc = true; |
45ac1403 | 7840 | } |
4beb31f3 | 7841 | if (has_branch_stack(event)) |
25432ae9 | 7842 | inc = true; |
4beb31f3 | 7843 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7844 | inc = true; |
7845 | ||
9107c89e PZ |
7846 | if (inc) { |
7847 | if (atomic_inc_not_zero(&perf_sched_count)) | |
7848 | goto enabled; | |
7849 | ||
7850 | mutex_lock(&perf_sched_mutex); | |
7851 | if (!atomic_read(&perf_sched_count)) { | |
7852 | static_branch_enable(&perf_sched_events); | |
7853 | /* | |
7854 | * Guarantee that all CPUs observe they key change and | |
7855 | * call the perf scheduling hooks before proceeding to | |
7856 | * install events that need them. | |
7857 | */ | |
7858 | synchronize_sched(); | |
7859 | } | |
7860 | /* | |
7861 | * Now that we have waited for the sync_sched(), allow further | |
7862 | * increments to by-pass the mutex. | |
7863 | */ | |
7864 | atomic_inc(&perf_sched_count); | |
7865 | mutex_unlock(&perf_sched_mutex); | |
7866 | } | |
7867 | enabled: | |
4beb31f3 FW |
7868 | |
7869 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7870 | } |
7871 | ||
0793a61d | 7872 | /* |
cdd6c482 | 7873 | * Allocate and initialize a event structure |
0793a61d | 7874 | */ |
cdd6c482 | 7875 | static struct perf_event * |
c3f00c70 | 7876 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7877 | struct task_struct *task, |
7878 | struct perf_event *group_leader, | |
7879 | struct perf_event *parent_event, | |
4dc0da86 | 7880 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7881 | void *context, int cgroup_fd) |
0793a61d | 7882 | { |
51b0fe39 | 7883 | struct pmu *pmu; |
cdd6c482 IM |
7884 | struct perf_event *event; |
7885 | struct hw_perf_event *hwc; | |
90983b16 | 7886 | long err = -EINVAL; |
0793a61d | 7887 | |
66832eb4 ON |
7888 | if ((unsigned)cpu >= nr_cpu_ids) { |
7889 | if (!task || cpu != -1) | |
7890 | return ERR_PTR(-EINVAL); | |
7891 | } | |
7892 | ||
c3f00c70 | 7893 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7894 | if (!event) |
d5d2bc0d | 7895 | return ERR_PTR(-ENOMEM); |
0793a61d | 7896 | |
04289bb9 | 7897 | /* |
cdd6c482 | 7898 | * Single events are their own group leaders, with an |
04289bb9 IM |
7899 | * empty sibling list: |
7900 | */ | |
7901 | if (!group_leader) | |
cdd6c482 | 7902 | group_leader = event; |
04289bb9 | 7903 | |
cdd6c482 IM |
7904 | mutex_init(&event->child_mutex); |
7905 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7906 | |
cdd6c482 IM |
7907 | INIT_LIST_HEAD(&event->group_entry); |
7908 | INIT_LIST_HEAD(&event->event_entry); | |
7909 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7910 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7911 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7912 | INIT_HLIST_NODE(&event->hlist_entry); |
7913 | ||
10c6db11 | 7914 | |
cdd6c482 | 7915 | init_waitqueue_head(&event->waitq); |
e360adbe | 7916 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7917 | |
cdd6c482 | 7918 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7919 | |
a6fa941d | 7920 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7921 | event->cpu = cpu; |
7922 | event->attr = *attr; | |
7923 | event->group_leader = group_leader; | |
7924 | event->pmu = NULL; | |
cdd6c482 | 7925 | event->oncpu = -1; |
a96bbc16 | 7926 | |
cdd6c482 | 7927 | event->parent = parent_event; |
b84fbc9f | 7928 | |
17cf22c3 | 7929 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7930 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7931 | |
cdd6c482 | 7932 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7933 | |
d580ff86 PZ |
7934 | if (task) { |
7935 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7936 | /* |
50f16a8b PZ |
7937 | * XXX pmu::event_init needs to know what task to account to |
7938 | * and we cannot use the ctx information because we need the | |
7939 | * pmu before we get a ctx. | |
d580ff86 | 7940 | */ |
50f16a8b | 7941 | event->hw.target = task; |
d580ff86 PZ |
7942 | } |
7943 | ||
34f43927 PZ |
7944 | event->clock = &local_clock; |
7945 | if (parent_event) | |
7946 | event->clock = parent_event->clock; | |
7947 | ||
4dc0da86 | 7948 | if (!overflow_handler && parent_event) { |
b326e956 | 7949 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7950 | context = parent_event->overflow_handler_context; |
7951 | } | |
66832eb4 | 7952 | |
b326e956 | 7953 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7954 | event->overflow_handler_context = context; |
97eaf530 | 7955 | |
0231bb53 | 7956 | perf_event__state_init(event); |
a86ed508 | 7957 | |
4aeb0b42 | 7958 | pmu = NULL; |
b8e83514 | 7959 | |
cdd6c482 | 7960 | hwc = &event->hw; |
bd2b5b12 | 7961 | hwc->sample_period = attr->sample_period; |
0d48696f | 7962 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7963 | hwc->sample_period = 1; |
eced1dfc | 7964 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7965 | |
e7850595 | 7966 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7967 | |
2023b359 | 7968 | /* |
cdd6c482 | 7969 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7970 | */ |
3dab77fb | 7971 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7972 | goto err_ns; |
a46a2300 YZ |
7973 | |
7974 | if (!has_branch_stack(event)) | |
7975 | event->attr.branch_sample_type = 0; | |
2023b359 | 7976 | |
79dff51e MF |
7977 | if (cgroup_fd != -1) { |
7978 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7979 | if (err) | |
7980 | goto err_ns; | |
7981 | } | |
7982 | ||
b0a873eb | 7983 | pmu = perf_init_event(event); |
4aeb0b42 | 7984 | if (!pmu) |
90983b16 FW |
7985 | goto err_ns; |
7986 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7987 | err = PTR_ERR(pmu); |
90983b16 | 7988 | goto err_ns; |
621a01ea | 7989 | } |
d5d2bc0d | 7990 | |
bed5b25a AS |
7991 | err = exclusive_event_init(event); |
7992 | if (err) | |
7993 | goto err_pmu; | |
7994 | ||
cdd6c482 | 7995 | if (!event->parent) { |
927c7a9e FW |
7996 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7997 | err = get_callchain_buffers(); | |
90983b16 | 7998 | if (err) |
bed5b25a | 7999 | goto err_per_task; |
d010b332 | 8000 | } |
f344011c | 8001 | } |
9ee318a7 | 8002 | |
cdd6c482 | 8003 | return event; |
90983b16 | 8004 | |
bed5b25a AS |
8005 | err_per_task: |
8006 | exclusive_event_destroy(event); | |
8007 | ||
90983b16 FW |
8008 | err_pmu: |
8009 | if (event->destroy) | |
8010 | event->destroy(event); | |
c464c76e | 8011 | module_put(pmu->module); |
90983b16 | 8012 | err_ns: |
79dff51e MF |
8013 | if (is_cgroup_event(event)) |
8014 | perf_detach_cgroup(event); | |
90983b16 FW |
8015 | if (event->ns) |
8016 | put_pid_ns(event->ns); | |
8017 | kfree(event); | |
8018 | ||
8019 | return ERR_PTR(err); | |
0793a61d TG |
8020 | } |
8021 | ||
cdd6c482 IM |
8022 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
8023 | struct perf_event_attr *attr) | |
974802ea | 8024 | { |
974802ea | 8025 | u32 size; |
cdf8073d | 8026 | int ret; |
974802ea PZ |
8027 | |
8028 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
8029 | return -EFAULT; | |
8030 | ||
8031 | /* | |
8032 | * zero the full structure, so that a short copy will be nice. | |
8033 | */ | |
8034 | memset(attr, 0, sizeof(*attr)); | |
8035 | ||
8036 | ret = get_user(size, &uattr->size); | |
8037 | if (ret) | |
8038 | return ret; | |
8039 | ||
8040 | if (size > PAGE_SIZE) /* silly large */ | |
8041 | goto err_size; | |
8042 | ||
8043 | if (!size) /* abi compat */ | |
8044 | size = PERF_ATTR_SIZE_VER0; | |
8045 | ||
8046 | if (size < PERF_ATTR_SIZE_VER0) | |
8047 | goto err_size; | |
8048 | ||
8049 | /* | |
8050 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
8051 | * ensure all the unknown bits are 0 - i.e. new |
8052 | * user-space does not rely on any kernel feature | |
8053 | * extensions we dont know about yet. | |
974802ea PZ |
8054 | */ |
8055 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
8056 | unsigned char __user *addr; |
8057 | unsigned char __user *end; | |
8058 | unsigned char val; | |
974802ea | 8059 | |
cdf8073d IS |
8060 | addr = (void __user *)uattr + sizeof(*attr); |
8061 | end = (void __user *)uattr + size; | |
974802ea | 8062 | |
cdf8073d | 8063 | for (; addr < end; addr++) { |
974802ea PZ |
8064 | ret = get_user(val, addr); |
8065 | if (ret) | |
8066 | return ret; | |
8067 | if (val) | |
8068 | goto err_size; | |
8069 | } | |
b3e62e35 | 8070 | size = sizeof(*attr); |
974802ea PZ |
8071 | } |
8072 | ||
8073 | ret = copy_from_user(attr, uattr, size); | |
8074 | if (ret) | |
8075 | return -EFAULT; | |
8076 | ||
cd757645 | 8077 | if (attr->__reserved_1) |
974802ea PZ |
8078 | return -EINVAL; |
8079 | ||
8080 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8081 | return -EINVAL; | |
8082 | ||
8083 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8084 | return -EINVAL; | |
8085 | ||
bce38cd5 SE |
8086 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8087 | u64 mask = attr->branch_sample_type; | |
8088 | ||
8089 | /* only using defined bits */ | |
8090 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8091 | return -EINVAL; | |
8092 | ||
8093 | /* at least one branch bit must be set */ | |
8094 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8095 | return -EINVAL; | |
8096 | ||
bce38cd5 SE |
8097 | /* propagate priv level, when not set for branch */ |
8098 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8099 | ||
8100 | /* exclude_kernel checked on syscall entry */ | |
8101 | if (!attr->exclude_kernel) | |
8102 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8103 | ||
8104 | if (!attr->exclude_user) | |
8105 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8106 | ||
8107 | if (!attr->exclude_hv) | |
8108 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8109 | /* | |
8110 | * adjust user setting (for HW filter setup) | |
8111 | */ | |
8112 | attr->branch_sample_type = mask; | |
8113 | } | |
e712209a SE |
8114 | /* privileged levels capture (kernel, hv): check permissions */ |
8115 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8116 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8117 | return -EACCES; | |
bce38cd5 | 8118 | } |
4018994f | 8119 | |
c5ebcedb | 8120 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8121 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8122 | if (ret) |
8123 | return ret; | |
8124 | } | |
8125 | ||
8126 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8127 | if (!arch_perf_have_user_stack_dump()) | |
8128 | return -ENOSYS; | |
8129 | ||
8130 | /* | |
8131 | * We have __u32 type for the size, but so far | |
8132 | * we can only use __u16 as maximum due to the | |
8133 | * __u16 sample size limit. | |
8134 | */ | |
8135 | if (attr->sample_stack_user >= USHRT_MAX) | |
8136 | ret = -EINVAL; | |
8137 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8138 | ret = -EINVAL; | |
8139 | } | |
4018994f | 8140 | |
60e2364e SE |
8141 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8142 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8143 | out: |
8144 | return ret; | |
8145 | ||
8146 | err_size: | |
8147 | put_user(sizeof(*attr), &uattr->size); | |
8148 | ret = -E2BIG; | |
8149 | goto out; | |
8150 | } | |
8151 | ||
ac9721f3 PZ |
8152 | static int |
8153 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8154 | { |
b69cf536 | 8155 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8156 | int ret = -EINVAL; |
8157 | ||
ac9721f3 | 8158 | if (!output_event) |
a4be7c27 PZ |
8159 | goto set; |
8160 | ||
ac9721f3 PZ |
8161 | /* don't allow circular references */ |
8162 | if (event == output_event) | |
a4be7c27 PZ |
8163 | goto out; |
8164 | ||
0f139300 PZ |
8165 | /* |
8166 | * Don't allow cross-cpu buffers | |
8167 | */ | |
8168 | if (output_event->cpu != event->cpu) | |
8169 | goto out; | |
8170 | ||
8171 | /* | |
76369139 | 8172 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8173 | */ |
8174 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8175 | goto out; | |
8176 | ||
34f43927 PZ |
8177 | /* |
8178 | * Mixing clocks in the same buffer is trouble you don't need. | |
8179 | */ | |
8180 | if (output_event->clock != event->clock) | |
8181 | goto out; | |
8182 | ||
45bfb2e5 PZ |
8183 | /* |
8184 | * If both events generate aux data, they must be on the same PMU | |
8185 | */ | |
8186 | if (has_aux(event) && has_aux(output_event) && | |
8187 | event->pmu != output_event->pmu) | |
8188 | goto out; | |
8189 | ||
a4be7c27 | 8190 | set: |
cdd6c482 | 8191 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8192 | /* Can't redirect output if we've got an active mmap() */ |
8193 | if (atomic_read(&event->mmap_count)) | |
8194 | goto unlock; | |
a4be7c27 | 8195 | |
ac9721f3 | 8196 | if (output_event) { |
76369139 FW |
8197 | /* get the rb we want to redirect to */ |
8198 | rb = ring_buffer_get(output_event); | |
8199 | if (!rb) | |
ac9721f3 | 8200 | goto unlock; |
a4be7c27 PZ |
8201 | } |
8202 | ||
b69cf536 | 8203 | ring_buffer_attach(event, rb); |
9bb5d40c | 8204 | |
a4be7c27 | 8205 | ret = 0; |
ac9721f3 PZ |
8206 | unlock: |
8207 | mutex_unlock(&event->mmap_mutex); | |
8208 | ||
a4be7c27 | 8209 | out: |
a4be7c27 PZ |
8210 | return ret; |
8211 | } | |
8212 | ||
f63a8daa PZ |
8213 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8214 | { | |
8215 | if (b < a) | |
8216 | swap(a, b); | |
8217 | ||
8218 | mutex_lock(a); | |
8219 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8220 | } | |
8221 | ||
34f43927 PZ |
8222 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8223 | { | |
8224 | bool nmi_safe = false; | |
8225 | ||
8226 | switch (clk_id) { | |
8227 | case CLOCK_MONOTONIC: | |
8228 | event->clock = &ktime_get_mono_fast_ns; | |
8229 | nmi_safe = true; | |
8230 | break; | |
8231 | ||
8232 | case CLOCK_MONOTONIC_RAW: | |
8233 | event->clock = &ktime_get_raw_fast_ns; | |
8234 | nmi_safe = true; | |
8235 | break; | |
8236 | ||
8237 | case CLOCK_REALTIME: | |
8238 | event->clock = &ktime_get_real_ns; | |
8239 | break; | |
8240 | ||
8241 | case CLOCK_BOOTTIME: | |
8242 | event->clock = &ktime_get_boot_ns; | |
8243 | break; | |
8244 | ||
8245 | case CLOCK_TAI: | |
8246 | event->clock = &ktime_get_tai_ns; | |
8247 | break; | |
8248 | ||
8249 | default: | |
8250 | return -EINVAL; | |
8251 | } | |
8252 | ||
8253 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8254 | return -EINVAL; | |
8255 | ||
8256 | return 0; | |
8257 | } | |
8258 | ||
0793a61d | 8259 | /** |
cdd6c482 | 8260 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8261 | * |
cdd6c482 | 8262 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8263 | * @pid: target pid |
9f66a381 | 8264 | * @cpu: target cpu |
cdd6c482 | 8265 | * @group_fd: group leader event fd |
0793a61d | 8266 | */ |
cdd6c482 IM |
8267 | SYSCALL_DEFINE5(perf_event_open, |
8268 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8269 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8270 | { |
b04243ef PZ |
8271 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8272 | struct perf_event *event, *sibling; | |
cdd6c482 | 8273 | struct perf_event_attr attr; |
f63a8daa | 8274 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8275 | struct file *event_file = NULL; |
2903ff01 | 8276 | struct fd group = {NULL, 0}; |
38a81da2 | 8277 | struct task_struct *task = NULL; |
89a1e187 | 8278 | struct pmu *pmu; |
ea635c64 | 8279 | int event_fd; |
b04243ef | 8280 | int move_group = 0; |
dc86cabe | 8281 | int err; |
a21b0b35 | 8282 | int f_flags = O_RDWR; |
79dff51e | 8283 | int cgroup_fd = -1; |
0793a61d | 8284 | |
2743a5b0 | 8285 | /* for future expandability... */ |
e5d1367f | 8286 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8287 | return -EINVAL; |
8288 | ||
dc86cabe IM |
8289 | err = perf_copy_attr(attr_uptr, &attr); |
8290 | if (err) | |
8291 | return err; | |
eab656ae | 8292 | |
0764771d PZ |
8293 | if (!attr.exclude_kernel) { |
8294 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8295 | return -EACCES; | |
8296 | } | |
8297 | ||
df58ab24 | 8298 | if (attr.freq) { |
cdd6c482 | 8299 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8300 | return -EINVAL; |
0819b2e3 PZ |
8301 | } else { |
8302 | if (attr.sample_period & (1ULL << 63)) | |
8303 | return -EINVAL; | |
df58ab24 PZ |
8304 | } |
8305 | ||
e5d1367f SE |
8306 | /* |
8307 | * In cgroup mode, the pid argument is used to pass the fd | |
8308 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8309 | * designates the cpu on which to monitor threads from that | |
8310 | * cgroup. | |
8311 | */ | |
8312 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8313 | return -EINVAL; | |
8314 | ||
a21b0b35 YD |
8315 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8316 | f_flags |= O_CLOEXEC; | |
8317 | ||
8318 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8319 | if (event_fd < 0) |
8320 | return event_fd; | |
8321 | ||
ac9721f3 | 8322 | if (group_fd != -1) { |
2903ff01 AV |
8323 | err = perf_fget_light(group_fd, &group); |
8324 | if (err) | |
d14b12d7 | 8325 | goto err_fd; |
2903ff01 | 8326 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8327 | if (flags & PERF_FLAG_FD_OUTPUT) |
8328 | output_event = group_leader; | |
8329 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8330 | group_leader = NULL; | |
8331 | } | |
8332 | ||
e5d1367f | 8333 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8334 | task = find_lively_task_by_vpid(pid); |
8335 | if (IS_ERR(task)) { | |
8336 | err = PTR_ERR(task); | |
8337 | goto err_group_fd; | |
8338 | } | |
8339 | } | |
8340 | ||
1f4ee503 PZ |
8341 | if (task && group_leader && |
8342 | group_leader->attr.inherit != attr.inherit) { | |
8343 | err = -EINVAL; | |
8344 | goto err_task; | |
8345 | } | |
8346 | ||
fbfc623f YZ |
8347 | get_online_cpus(); |
8348 | ||
79dff51e MF |
8349 | if (flags & PERF_FLAG_PID_CGROUP) |
8350 | cgroup_fd = pid; | |
8351 | ||
4dc0da86 | 8352 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8353 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8354 | if (IS_ERR(event)) { |
8355 | err = PTR_ERR(event); | |
1f4ee503 | 8356 | goto err_cpus; |
d14b12d7 SE |
8357 | } |
8358 | ||
53b25335 VW |
8359 | if (is_sampling_event(event)) { |
8360 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8361 | err = -ENOTSUPP; | |
8362 | goto err_alloc; | |
8363 | } | |
8364 | } | |
8365 | ||
766d6c07 FW |
8366 | account_event(event); |
8367 | ||
89a1e187 PZ |
8368 | /* |
8369 | * Special case software events and allow them to be part of | |
8370 | * any hardware group. | |
8371 | */ | |
8372 | pmu = event->pmu; | |
b04243ef | 8373 | |
34f43927 PZ |
8374 | if (attr.use_clockid) { |
8375 | err = perf_event_set_clock(event, attr.clockid); | |
8376 | if (err) | |
8377 | goto err_alloc; | |
8378 | } | |
8379 | ||
b04243ef PZ |
8380 | if (group_leader && |
8381 | (is_software_event(event) != is_software_event(group_leader))) { | |
8382 | if (is_software_event(event)) { | |
8383 | /* | |
8384 | * If event and group_leader are not both a software | |
8385 | * event, and event is, then group leader is not. | |
8386 | * | |
8387 | * Allow the addition of software events to !software | |
8388 | * groups, this is safe because software events never | |
8389 | * fail to schedule. | |
8390 | */ | |
8391 | pmu = group_leader->pmu; | |
8392 | } else if (is_software_event(group_leader) && | |
8393 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8394 | /* | |
8395 | * In case the group is a pure software group, and we | |
8396 | * try to add a hardware event, move the whole group to | |
8397 | * the hardware context. | |
8398 | */ | |
8399 | move_group = 1; | |
8400 | } | |
8401 | } | |
89a1e187 PZ |
8402 | |
8403 | /* | |
8404 | * Get the target context (task or percpu): | |
8405 | */ | |
4af57ef2 | 8406 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8407 | if (IS_ERR(ctx)) { |
8408 | err = PTR_ERR(ctx); | |
c6be5a5c | 8409 | goto err_alloc; |
89a1e187 PZ |
8410 | } |
8411 | ||
bed5b25a AS |
8412 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8413 | err = -EBUSY; | |
8414 | goto err_context; | |
8415 | } | |
8416 | ||
fd1edb3a PZ |
8417 | if (task) { |
8418 | put_task_struct(task); | |
8419 | task = NULL; | |
8420 | } | |
8421 | ||
ccff286d | 8422 | /* |
cdd6c482 | 8423 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8424 | */ |
ac9721f3 | 8425 | if (group_leader) { |
dc86cabe | 8426 | err = -EINVAL; |
04289bb9 | 8427 | |
04289bb9 | 8428 | /* |
ccff286d IM |
8429 | * Do not allow a recursive hierarchy (this new sibling |
8430 | * becoming part of another group-sibling): | |
8431 | */ | |
8432 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8433 | goto err_context; |
34f43927 PZ |
8434 | |
8435 | /* All events in a group should have the same clock */ | |
8436 | if (group_leader->clock != event->clock) | |
8437 | goto err_context; | |
8438 | ||
ccff286d IM |
8439 | /* |
8440 | * Do not allow to attach to a group in a different | |
8441 | * task or CPU context: | |
04289bb9 | 8442 | */ |
b04243ef | 8443 | if (move_group) { |
c3c87e77 PZ |
8444 | /* |
8445 | * Make sure we're both on the same task, or both | |
8446 | * per-cpu events. | |
8447 | */ | |
8448 | if (group_leader->ctx->task != ctx->task) | |
8449 | goto err_context; | |
8450 | ||
8451 | /* | |
8452 | * Make sure we're both events for the same CPU; | |
8453 | * grouping events for different CPUs is broken; since | |
8454 | * you can never concurrently schedule them anyhow. | |
8455 | */ | |
8456 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8457 | goto err_context; |
8458 | } else { | |
8459 | if (group_leader->ctx != ctx) | |
8460 | goto err_context; | |
8461 | } | |
8462 | ||
3b6f9e5c PM |
8463 | /* |
8464 | * Only a group leader can be exclusive or pinned | |
8465 | */ | |
0d48696f | 8466 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8467 | goto err_context; |
ac9721f3 PZ |
8468 | } |
8469 | ||
8470 | if (output_event) { | |
8471 | err = perf_event_set_output(event, output_event); | |
8472 | if (err) | |
c3f00c70 | 8473 | goto err_context; |
ac9721f3 | 8474 | } |
0793a61d | 8475 | |
a21b0b35 YD |
8476 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8477 | f_flags); | |
ea635c64 AV |
8478 | if (IS_ERR(event_file)) { |
8479 | err = PTR_ERR(event_file); | |
c3f00c70 | 8480 | goto err_context; |
ea635c64 | 8481 | } |
9b51f66d | 8482 | |
b04243ef | 8483 | if (move_group) { |
f63a8daa | 8484 | gctx = group_leader->ctx; |
f55fc2a5 | 8485 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
84c4e620 PZ |
8486 | if (gctx->task == TASK_TOMBSTONE) { |
8487 | err = -ESRCH; | |
8488 | goto err_locked; | |
8489 | } | |
f55fc2a5 PZ |
8490 | } else { |
8491 | mutex_lock(&ctx->mutex); | |
8492 | } | |
8493 | ||
84c4e620 PZ |
8494 | if (ctx->task == TASK_TOMBSTONE) { |
8495 | err = -ESRCH; | |
8496 | goto err_locked; | |
8497 | } | |
8498 | ||
a723968c PZ |
8499 | if (!perf_event_validate_size(event)) { |
8500 | err = -E2BIG; | |
8501 | goto err_locked; | |
8502 | } | |
8503 | ||
f55fc2a5 PZ |
8504 | /* |
8505 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8506 | * because we need to serialize with concurrent event creation. | |
8507 | */ | |
8508 | if (!exclusive_event_installable(event, ctx)) { | |
8509 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8510 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8511 | |
f55fc2a5 PZ |
8512 | err = -EBUSY; |
8513 | goto err_locked; | |
8514 | } | |
f63a8daa | 8515 | |
f55fc2a5 PZ |
8516 | WARN_ON_ONCE(ctx->parent_ctx); |
8517 | ||
8518 | if (move_group) { | |
f63a8daa PZ |
8519 | /* |
8520 | * See perf_event_ctx_lock() for comments on the details | |
8521 | * of swizzling perf_event::ctx. | |
8522 | */ | |
45a0e07a | 8523 | perf_remove_from_context(group_leader, 0); |
0231bb53 | 8524 | |
b04243ef PZ |
8525 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8526 | group_entry) { | |
45a0e07a | 8527 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
8528 | put_ctx(gctx); |
8529 | } | |
b04243ef | 8530 | |
f63a8daa PZ |
8531 | /* |
8532 | * Wait for everybody to stop referencing the events through | |
8533 | * the old lists, before installing it on new lists. | |
8534 | */ | |
0cda4c02 | 8535 | synchronize_rcu(); |
f63a8daa | 8536 | |
8f95b435 PZI |
8537 | /* |
8538 | * Install the group siblings before the group leader. | |
8539 | * | |
8540 | * Because a group leader will try and install the entire group | |
8541 | * (through the sibling list, which is still in-tact), we can | |
8542 | * end up with siblings installed in the wrong context. | |
8543 | * | |
8544 | * By installing siblings first we NO-OP because they're not | |
8545 | * reachable through the group lists. | |
8546 | */ | |
b04243ef PZ |
8547 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8548 | group_entry) { | |
8f95b435 | 8549 | perf_event__state_init(sibling); |
9fc81d87 | 8550 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8551 | get_ctx(ctx); |
8552 | } | |
8f95b435 PZI |
8553 | |
8554 | /* | |
8555 | * Removing from the context ends up with disabled | |
8556 | * event. What we want here is event in the initial | |
8557 | * startup state, ready to be add into new context. | |
8558 | */ | |
8559 | perf_event__state_init(group_leader); | |
8560 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8561 | get_ctx(ctx); | |
b04243ef | 8562 | |
f55fc2a5 PZ |
8563 | /* |
8564 | * Now that all events are installed in @ctx, nothing | |
8565 | * references @gctx anymore, so drop the last reference we have | |
8566 | * on it. | |
8567 | */ | |
8568 | put_ctx(gctx); | |
bed5b25a AS |
8569 | } |
8570 | ||
f73e22ab PZ |
8571 | /* |
8572 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8573 | * that we're serialized against further additions and before | |
8574 | * perf_install_in_context() which is the point the event is active and | |
8575 | * can use these values. | |
8576 | */ | |
8577 | perf_event__header_size(event); | |
8578 | perf_event__id_header_size(event); | |
8579 | ||
78cd2c74 PZ |
8580 | event->owner = current; |
8581 | ||
e2d37cd2 | 8582 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8583 | perf_unpin_context(ctx); |
f63a8daa | 8584 | |
f55fc2a5 | 8585 | if (move_group) |
f63a8daa | 8586 | mutex_unlock(&gctx->mutex); |
d859e29f | 8587 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8588 | |
fbfc623f YZ |
8589 | put_online_cpus(); |
8590 | ||
cdd6c482 IM |
8591 | mutex_lock(¤t->perf_event_mutex); |
8592 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8593 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8594 | |
8a49542c PZ |
8595 | /* |
8596 | * Drop the reference on the group_event after placing the | |
8597 | * new event on the sibling_list. This ensures destruction | |
8598 | * of the group leader will find the pointer to itself in | |
8599 | * perf_group_detach(). | |
8600 | */ | |
2903ff01 | 8601 | fdput(group); |
ea635c64 AV |
8602 | fd_install(event_fd, event_file); |
8603 | return event_fd; | |
0793a61d | 8604 | |
f55fc2a5 PZ |
8605 | err_locked: |
8606 | if (move_group) | |
8607 | mutex_unlock(&gctx->mutex); | |
8608 | mutex_unlock(&ctx->mutex); | |
8609 | /* err_file: */ | |
8610 | fput(event_file); | |
c3f00c70 | 8611 | err_context: |
fe4b04fa | 8612 | perf_unpin_context(ctx); |
ea635c64 | 8613 | put_ctx(ctx); |
c6be5a5c | 8614 | err_alloc: |
13005627 PZ |
8615 | /* |
8616 | * If event_file is set, the fput() above will have called ->release() | |
8617 | * and that will take care of freeing the event. | |
8618 | */ | |
8619 | if (!event_file) | |
8620 | free_event(event); | |
1f4ee503 | 8621 | err_cpus: |
fbfc623f | 8622 | put_online_cpus(); |
1f4ee503 | 8623 | err_task: |
e7d0bc04 PZ |
8624 | if (task) |
8625 | put_task_struct(task); | |
89a1e187 | 8626 | err_group_fd: |
2903ff01 | 8627 | fdput(group); |
ea635c64 AV |
8628 | err_fd: |
8629 | put_unused_fd(event_fd); | |
dc86cabe | 8630 | return err; |
0793a61d TG |
8631 | } |
8632 | ||
fb0459d7 AV |
8633 | /** |
8634 | * perf_event_create_kernel_counter | |
8635 | * | |
8636 | * @attr: attributes of the counter to create | |
8637 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8638 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8639 | */ |
8640 | struct perf_event * | |
8641 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8642 | struct task_struct *task, |
4dc0da86 AK |
8643 | perf_overflow_handler_t overflow_handler, |
8644 | void *context) | |
fb0459d7 | 8645 | { |
fb0459d7 | 8646 | struct perf_event_context *ctx; |
c3f00c70 | 8647 | struct perf_event *event; |
fb0459d7 | 8648 | int err; |
d859e29f | 8649 | |
fb0459d7 AV |
8650 | /* |
8651 | * Get the target context (task or percpu): | |
8652 | */ | |
d859e29f | 8653 | |
4dc0da86 | 8654 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8655 | overflow_handler, context, -1); |
c3f00c70 PZ |
8656 | if (IS_ERR(event)) { |
8657 | err = PTR_ERR(event); | |
8658 | goto err; | |
8659 | } | |
d859e29f | 8660 | |
f8697762 | 8661 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 8662 | event->owner = TASK_TOMBSTONE; |
f8697762 | 8663 | |
766d6c07 FW |
8664 | account_event(event); |
8665 | ||
4af57ef2 | 8666 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8667 | if (IS_ERR(ctx)) { |
8668 | err = PTR_ERR(ctx); | |
c3f00c70 | 8669 | goto err_free; |
d859e29f | 8670 | } |
fb0459d7 | 8671 | |
fb0459d7 AV |
8672 | WARN_ON_ONCE(ctx->parent_ctx); |
8673 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
8674 | if (ctx->task == TASK_TOMBSTONE) { |
8675 | err = -ESRCH; | |
8676 | goto err_unlock; | |
8677 | } | |
8678 | ||
bed5b25a | 8679 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 8680 | err = -EBUSY; |
84c4e620 | 8681 | goto err_unlock; |
bed5b25a AS |
8682 | } |
8683 | ||
fb0459d7 | 8684 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8685 | perf_unpin_context(ctx); |
fb0459d7 AV |
8686 | mutex_unlock(&ctx->mutex); |
8687 | ||
fb0459d7 AV |
8688 | return event; |
8689 | ||
84c4e620 PZ |
8690 | err_unlock: |
8691 | mutex_unlock(&ctx->mutex); | |
8692 | perf_unpin_context(ctx); | |
8693 | put_ctx(ctx); | |
c3f00c70 PZ |
8694 | err_free: |
8695 | free_event(event); | |
8696 | err: | |
c6567f64 | 8697 | return ERR_PTR(err); |
9b51f66d | 8698 | } |
fb0459d7 | 8699 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8700 | |
0cda4c02 YZ |
8701 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8702 | { | |
8703 | struct perf_event_context *src_ctx; | |
8704 | struct perf_event_context *dst_ctx; | |
8705 | struct perf_event *event, *tmp; | |
8706 | LIST_HEAD(events); | |
8707 | ||
8708 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8709 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8710 | ||
f63a8daa PZ |
8711 | /* |
8712 | * See perf_event_ctx_lock() for comments on the details | |
8713 | * of swizzling perf_event::ctx. | |
8714 | */ | |
8715 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8716 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8717 | event_entry) { | |
45a0e07a | 8718 | perf_remove_from_context(event, 0); |
9a545de0 | 8719 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8720 | put_ctx(src_ctx); |
9886167d | 8721 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8722 | } |
0cda4c02 | 8723 | |
8f95b435 PZI |
8724 | /* |
8725 | * Wait for the events to quiesce before re-instating them. | |
8726 | */ | |
0cda4c02 YZ |
8727 | synchronize_rcu(); |
8728 | ||
8f95b435 PZI |
8729 | /* |
8730 | * Re-instate events in 2 passes. | |
8731 | * | |
8732 | * Skip over group leaders and only install siblings on this first | |
8733 | * pass, siblings will not get enabled without a leader, however a | |
8734 | * leader will enable its siblings, even if those are still on the old | |
8735 | * context. | |
8736 | */ | |
8737 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8738 | if (event->group_leader == event) | |
8739 | continue; | |
8740 | ||
8741 | list_del(&event->migrate_entry); | |
8742 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8743 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8744 | account_event_cpu(event, dst_cpu); | |
8745 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8746 | get_ctx(dst_ctx); | |
8747 | } | |
8748 | ||
8749 | /* | |
8750 | * Once all the siblings are setup properly, install the group leaders | |
8751 | * to make it go. | |
8752 | */ | |
9886167d PZ |
8753 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8754 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8755 | if (event->state >= PERF_EVENT_STATE_OFF) |
8756 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8757 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8758 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8759 | get_ctx(dst_ctx); | |
8760 | } | |
8761 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8762 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8763 | } |
8764 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8765 | ||
cdd6c482 | 8766 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8767 | struct task_struct *child) |
d859e29f | 8768 | { |
cdd6c482 | 8769 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8770 | u64 child_val; |
d859e29f | 8771 | |
cdd6c482 IM |
8772 | if (child_event->attr.inherit_stat) |
8773 | perf_event_read_event(child_event, child); | |
38b200d6 | 8774 | |
b5e58793 | 8775 | child_val = perf_event_count(child_event); |
d859e29f PM |
8776 | |
8777 | /* | |
8778 | * Add back the child's count to the parent's count: | |
8779 | */ | |
a6e6dea6 | 8780 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8781 | atomic64_add(child_event->total_time_enabled, |
8782 | &parent_event->child_total_time_enabled); | |
8783 | atomic64_add(child_event->total_time_running, | |
8784 | &parent_event->child_total_time_running); | |
d859e29f PM |
8785 | } |
8786 | ||
9b51f66d | 8787 | static void |
8ba289b8 PZ |
8788 | perf_event_exit_event(struct perf_event *child_event, |
8789 | struct perf_event_context *child_ctx, | |
8790 | struct task_struct *child) | |
9b51f66d | 8791 | { |
8ba289b8 PZ |
8792 | struct perf_event *parent_event = child_event->parent; |
8793 | ||
1903d50c PZ |
8794 | /* |
8795 | * Do not destroy the 'original' grouping; because of the context | |
8796 | * switch optimization the original events could've ended up in a | |
8797 | * random child task. | |
8798 | * | |
8799 | * If we were to destroy the original group, all group related | |
8800 | * operations would cease to function properly after this random | |
8801 | * child dies. | |
8802 | * | |
8803 | * Do destroy all inherited groups, we don't care about those | |
8804 | * and being thorough is better. | |
8805 | */ | |
32132a3d PZ |
8806 | raw_spin_lock_irq(&child_ctx->lock); |
8807 | WARN_ON_ONCE(child_ctx->is_active); | |
8808 | ||
8ba289b8 | 8809 | if (parent_event) |
32132a3d PZ |
8810 | perf_group_detach(child_event); |
8811 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 8812 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 8813 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 8814 | |
9b51f66d | 8815 | /* |
8ba289b8 | 8816 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 8817 | */ |
8ba289b8 | 8818 | if (!parent_event) { |
179033b3 | 8819 | perf_event_wakeup(child_event); |
8ba289b8 | 8820 | return; |
4bcf349a | 8821 | } |
8ba289b8 PZ |
8822 | /* |
8823 | * Child events can be cleaned up. | |
8824 | */ | |
8825 | ||
8826 | sync_child_event(child_event, child); | |
8827 | ||
8828 | /* | |
8829 | * Remove this event from the parent's list | |
8830 | */ | |
8831 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8832 | mutex_lock(&parent_event->child_mutex); | |
8833 | list_del_init(&child_event->child_list); | |
8834 | mutex_unlock(&parent_event->child_mutex); | |
8835 | ||
8836 | /* | |
8837 | * Kick perf_poll() for is_event_hup(). | |
8838 | */ | |
8839 | perf_event_wakeup(parent_event); | |
8840 | free_event(child_event); | |
8841 | put_event(parent_event); | |
9b51f66d IM |
8842 | } |
8843 | ||
8dc85d54 | 8844 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8845 | { |
211de6eb | 8846 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 8847 | struct perf_event *child_event, *next; |
63b6da39 PZ |
8848 | |
8849 | WARN_ON_ONCE(child != current); | |
9b51f66d | 8850 | |
6a3351b6 | 8851 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 8852 | if (!child_ctx) |
9b51f66d IM |
8853 | return; |
8854 | ||
ad3a37de | 8855 | /* |
6a3351b6 PZ |
8856 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
8857 | * ctx::mutex over the entire thing. This serializes against almost | |
8858 | * everything that wants to access the ctx. | |
8859 | * | |
8860 | * The exception is sys_perf_event_open() / | |
8861 | * perf_event_create_kernel_count() which does find_get_context() | |
8862 | * without ctx::mutex (it cannot because of the move_group double mutex | |
8863 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 8864 | */ |
6a3351b6 | 8865 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
8866 | |
8867 | /* | |
6a3351b6 PZ |
8868 | * In a single ctx::lock section, de-schedule the events and detach the |
8869 | * context from the task such that we cannot ever get it scheduled back | |
8870 | * in. | |
c93f7669 | 8871 | */ |
6a3351b6 | 8872 | raw_spin_lock_irq(&child_ctx->lock); |
63b6da39 | 8873 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
4a1c0f26 | 8874 | |
71a851b4 | 8875 | /* |
63b6da39 PZ |
8876 | * Now that the context is inactive, destroy the task <-> ctx relation |
8877 | * and mark the context dead. | |
71a851b4 | 8878 | */ |
63b6da39 PZ |
8879 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
8880 | put_ctx(child_ctx); /* cannot be last */ | |
8881 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
8882 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 8883 | |
211de6eb | 8884 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 8885 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 8886 | |
211de6eb PZ |
8887 | if (clone_ctx) |
8888 | put_ctx(clone_ctx); | |
4a1c0f26 | 8889 | |
9f498cc5 | 8890 | /* |
cdd6c482 IM |
8891 | * Report the task dead after unscheduling the events so that we |
8892 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8893 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8894 | */ |
cdd6c482 | 8895 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8896 | |
ebf905fc | 8897 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 8898 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 8899 | |
a63eaf34 PM |
8900 | mutex_unlock(&child_ctx->mutex); |
8901 | ||
8902 | put_ctx(child_ctx); | |
9b51f66d IM |
8903 | } |
8904 | ||
8dc85d54 PZ |
8905 | /* |
8906 | * When a child task exits, feed back event values to parent events. | |
8907 | */ | |
8908 | void perf_event_exit_task(struct task_struct *child) | |
8909 | { | |
8882135b | 8910 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8911 | int ctxn; |
8912 | ||
8882135b PZ |
8913 | mutex_lock(&child->perf_event_mutex); |
8914 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8915 | owner_entry) { | |
8916 | list_del_init(&event->owner_entry); | |
8917 | ||
8918 | /* | |
8919 | * Ensure the list deletion is visible before we clear | |
8920 | * the owner, closes a race against perf_release() where | |
8921 | * we need to serialize on the owner->perf_event_mutex. | |
8922 | */ | |
f47c02c0 | 8923 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
8924 | } |
8925 | mutex_unlock(&child->perf_event_mutex); | |
8926 | ||
8dc85d54 PZ |
8927 | for_each_task_context_nr(ctxn) |
8928 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8929 | |
8930 | /* | |
8931 | * The perf_event_exit_task_context calls perf_event_task | |
8932 | * with child's task_ctx, which generates EXIT events for | |
8933 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8934 | * At this point we need to send EXIT events to cpu contexts. | |
8935 | */ | |
8936 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8937 | } |
8938 | ||
889ff015 FW |
8939 | static void perf_free_event(struct perf_event *event, |
8940 | struct perf_event_context *ctx) | |
8941 | { | |
8942 | struct perf_event *parent = event->parent; | |
8943 | ||
8944 | if (WARN_ON_ONCE(!parent)) | |
8945 | return; | |
8946 | ||
8947 | mutex_lock(&parent->child_mutex); | |
8948 | list_del_init(&event->child_list); | |
8949 | mutex_unlock(&parent->child_mutex); | |
8950 | ||
a6fa941d | 8951 | put_event(parent); |
889ff015 | 8952 | |
652884fe | 8953 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8954 | perf_group_detach(event); |
889ff015 | 8955 | list_del_event(event, ctx); |
652884fe | 8956 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8957 | free_event(event); |
8958 | } | |
8959 | ||
bbbee908 | 8960 | /* |
652884fe | 8961 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8962 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8963 | * |
8964 | * Not all locks are strictly required, but take them anyway to be nice and | |
8965 | * help out with the lockdep assertions. | |
bbbee908 | 8966 | */ |
cdd6c482 | 8967 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8968 | { |
8dc85d54 | 8969 | struct perf_event_context *ctx; |
cdd6c482 | 8970 | struct perf_event *event, *tmp; |
8dc85d54 | 8971 | int ctxn; |
bbbee908 | 8972 | |
8dc85d54 PZ |
8973 | for_each_task_context_nr(ctxn) { |
8974 | ctx = task->perf_event_ctxp[ctxn]; | |
8975 | if (!ctx) | |
8976 | continue; | |
bbbee908 | 8977 | |
8dc85d54 | 8978 | mutex_lock(&ctx->mutex); |
bbbee908 | 8979 | again: |
8dc85d54 PZ |
8980 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8981 | group_entry) | |
8982 | perf_free_event(event, ctx); | |
bbbee908 | 8983 | |
8dc85d54 PZ |
8984 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8985 | group_entry) | |
8986 | perf_free_event(event, ctx); | |
bbbee908 | 8987 | |
8dc85d54 PZ |
8988 | if (!list_empty(&ctx->pinned_groups) || |
8989 | !list_empty(&ctx->flexible_groups)) | |
8990 | goto again; | |
bbbee908 | 8991 | |
8dc85d54 | 8992 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8993 | |
8dc85d54 PZ |
8994 | put_ctx(ctx); |
8995 | } | |
889ff015 FW |
8996 | } |
8997 | ||
4e231c79 PZ |
8998 | void perf_event_delayed_put(struct task_struct *task) |
8999 | { | |
9000 | int ctxn; | |
9001 | ||
9002 | for_each_task_context_nr(ctxn) | |
9003 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
9004 | } | |
9005 | ||
e03e7ee3 | 9006 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 9007 | { |
e03e7ee3 | 9008 | struct file *file; |
ffe8690c | 9009 | |
e03e7ee3 AS |
9010 | file = fget_raw(fd); |
9011 | if (!file) | |
9012 | return ERR_PTR(-EBADF); | |
ffe8690c | 9013 | |
e03e7ee3 AS |
9014 | if (file->f_op != &perf_fops) { |
9015 | fput(file); | |
9016 | return ERR_PTR(-EBADF); | |
9017 | } | |
ffe8690c | 9018 | |
e03e7ee3 | 9019 | return file; |
ffe8690c KX |
9020 | } |
9021 | ||
9022 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
9023 | { | |
9024 | if (!event) | |
9025 | return ERR_PTR(-EINVAL); | |
9026 | ||
9027 | return &event->attr; | |
9028 | } | |
9029 | ||
97dee4f3 PZ |
9030 | /* |
9031 | * inherit a event from parent task to child task: | |
9032 | */ | |
9033 | static struct perf_event * | |
9034 | inherit_event(struct perf_event *parent_event, | |
9035 | struct task_struct *parent, | |
9036 | struct perf_event_context *parent_ctx, | |
9037 | struct task_struct *child, | |
9038 | struct perf_event *group_leader, | |
9039 | struct perf_event_context *child_ctx) | |
9040 | { | |
1929def9 | 9041 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 9042 | struct perf_event *child_event; |
cee010ec | 9043 | unsigned long flags; |
97dee4f3 PZ |
9044 | |
9045 | /* | |
9046 | * Instead of creating recursive hierarchies of events, | |
9047 | * we link inherited events back to the original parent, | |
9048 | * which has a filp for sure, which we use as the reference | |
9049 | * count: | |
9050 | */ | |
9051 | if (parent_event->parent) | |
9052 | parent_event = parent_event->parent; | |
9053 | ||
9054 | child_event = perf_event_alloc(&parent_event->attr, | |
9055 | parent_event->cpu, | |
d580ff86 | 9056 | child, |
97dee4f3 | 9057 | group_leader, parent_event, |
79dff51e | 9058 | NULL, NULL, -1); |
97dee4f3 PZ |
9059 | if (IS_ERR(child_event)) |
9060 | return child_event; | |
a6fa941d | 9061 | |
c6e5b732 PZ |
9062 | /* |
9063 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
9064 | * must be under the same lock in order to serialize against | |
9065 | * perf_event_release_kernel(), such that either we must observe | |
9066 | * is_orphaned_event() or they will observe us on the child_list. | |
9067 | */ | |
9068 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
9069 | if (is_orphaned_event(parent_event) || |
9070 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 9071 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
9072 | free_event(child_event); |
9073 | return NULL; | |
9074 | } | |
9075 | ||
97dee4f3 PZ |
9076 | get_ctx(child_ctx); |
9077 | ||
9078 | /* | |
9079 | * Make the child state follow the state of the parent event, | |
9080 | * not its attr.disabled bit. We hold the parent's mutex, | |
9081 | * so we won't race with perf_event_{en, dis}able_family. | |
9082 | */ | |
1929def9 | 9083 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
9084 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
9085 | else | |
9086 | child_event->state = PERF_EVENT_STATE_OFF; | |
9087 | ||
9088 | if (parent_event->attr.freq) { | |
9089 | u64 sample_period = parent_event->hw.sample_period; | |
9090 | struct hw_perf_event *hwc = &child_event->hw; | |
9091 | ||
9092 | hwc->sample_period = sample_period; | |
9093 | hwc->last_period = sample_period; | |
9094 | ||
9095 | local64_set(&hwc->period_left, sample_period); | |
9096 | } | |
9097 | ||
9098 | child_event->ctx = child_ctx; | |
9099 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
9100 | child_event->overflow_handler_context |
9101 | = parent_event->overflow_handler_context; | |
97dee4f3 | 9102 | |
614b6780 TG |
9103 | /* |
9104 | * Precalculate sample_data sizes | |
9105 | */ | |
9106 | perf_event__header_size(child_event); | |
6844c09d | 9107 | perf_event__id_header_size(child_event); |
614b6780 | 9108 | |
97dee4f3 PZ |
9109 | /* |
9110 | * Link it up in the child's context: | |
9111 | */ | |
cee010ec | 9112 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9113 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9114 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9115 | |
97dee4f3 PZ |
9116 | /* |
9117 | * Link this into the parent event's child list | |
9118 | */ | |
97dee4f3 PZ |
9119 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
9120 | mutex_unlock(&parent_event->child_mutex); | |
9121 | ||
9122 | return child_event; | |
9123 | } | |
9124 | ||
9125 | static int inherit_group(struct perf_event *parent_event, | |
9126 | struct task_struct *parent, | |
9127 | struct perf_event_context *parent_ctx, | |
9128 | struct task_struct *child, | |
9129 | struct perf_event_context *child_ctx) | |
9130 | { | |
9131 | struct perf_event *leader; | |
9132 | struct perf_event *sub; | |
9133 | struct perf_event *child_ctr; | |
9134 | ||
9135 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9136 | child, NULL, child_ctx); | |
9137 | if (IS_ERR(leader)) | |
9138 | return PTR_ERR(leader); | |
9139 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9140 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9141 | child, leader, child_ctx); | |
9142 | if (IS_ERR(child_ctr)) | |
9143 | return PTR_ERR(child_ctr); | |
9144 | } | |
9145 | return 0; | |
889ff015 FW |
9146 | } |
9147 | ||
9148 | static int | |
9149 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9150 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9151 | struct task_struct *child, int ctxn, |
889ff015 FW |
9152 | int *inherited_all) |
9153 | { | |
9154 | int ret; | |
8dc85d54 | 9155 | struct perf_event_context *child_ctx; |
889ff015 FW |
9156 | |
9157 | if (!event->attr.inherit) { | |
9158 | *inherited_all = 0; | |
9159 | return 0; | |
bbbee908 PZ |
9160 | } |
9161 | ||
fe4b04fa | 9162 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9163 | if (!child_ctx) { |
9164 | /* | |
9165 | * This is executed from the parent task context, so | |
9166 | * inherit events that have been marked for cloning. | |
9167 | * First allocate and initialize a context for the | |
9168 | * child. | |
9169 | */ | |
bbbee908 | 9170 | |
734df5ab | 9171 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9172 | if (!child_ctx) |
9173 | return -ENOMEM; | |
bbbee908 | 9174 | |
8dc85d54 | 9175 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9176 | } |
9177 | ||
9178 | ret = inherit_group(event, parent, parent_ctx, | |
9179 | child, child_ctx); | |
9180 | ||
9181 | if (ret) | |
9182 | *inherited_all = 0; | |
9183 | ||
9184 | return ret; | |
bbbee908 PZ |
9185 | } |
9186 | ||
9b51f66d | 9187 | /* |
cdd6c482 | 9188 | * Initialize the perf_event context in task_struct |
9b51f66d | 9189 | */ |
985c8dcb | 9190 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9191 | { |
889ff015 | 9192 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9193 | struct perf_event_context *cloned_ctx; |
9194 | struct perf_event *event; | |
9b51f66d | 9195 | struct task_struct *parent = current; |
564c2b21 | 9196 | int inherited_all = 1; |
dddd3379 | 9197 | unsigned long flags; |
6ab423e0 | 9198 | int ret = 0; |
9b51f66d | 9199 | |
8dc85d54 | 9200 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9201 | return 0; |
9202 | ||
ad3a37de | 9203 | /* |
25346b93 PM |
9204 | * If the parent's context is a clone, pin it so it won't get |
9205 | * swapped under us. | |
ad3a37de | 9206 | */ |
8dc85d54 | 9207 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9208 | if (!parent_ctx) |
9209 | return 0; | |
25346b93 | 9210 | |
ad3a37de PM |
9211 | /* |
9212 | * No need to check if parent_ctx != NULL here; since we saw | |
9213 | * it non-NULL earlier, the only reason for it to become NULL | |
9214 | * is if we exit, and since we're currently in the middle of | |
9215 | * a fork we can't be exiting at the same time. | |
9216 | */ | |
ad3a37de | 9217 | |
9b51f66d IM |
9218 | /* |
9219 | * Lock the parent list. No need to lock the child - not PID | |
9220 | * hashed yet and not running, so nobody can access it. | |
9221 | */ | |
d859e29f | 9222 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9223 | |
9224 | /* | |
9225 | * We dont have to disable NMIs - we are only looking at | |
9226 | * the list, not manipulating it: | |
9227 | */ | |
889ff015 | 9228 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9229 | ret = inherit_task_group(event, parent, parent_ctx, |
9230 | child, ctxn, &inherited_all); | |
889ff015 FW |
9231 | if (ret) |
9232 | break; | |
9233 | } | |
b93f7978 | 9234 | |
dddd3379 TG |
9235 | /* |
9236 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9237 | * to allocations, but we need to prevent rotation because | |
9238 | * rotate_ctx() will change the list from interrupt context. | |
9239 | */ | |
9240 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9241 | parent_ctx->rotate_disable = 1; | |
9242 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9243 | ||
889ff015 | 9244 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9245 | ret = inherit_task_group(event, parent, parent_ctx, |
9246 | child, ctxn, &inherited_all); | |
889ff015 | 9247 | if (ret) |
9b51f66d | 9248 | break; |
564c2b21 PM |
9249 | } |
9250 | ||
dddd3379 TG |
9251 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9252 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9253 | |
8dc85d54 | 9254 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9255 | |
05cbaa28 | 9256 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9257 | /* |
9258 | * Mark the child context as a clone of the parent | |
9259 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9260 | * |
9261 | * Note that if the parent is a clone, the holding of | |
9262 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9263 | */ |
c5ed5145 | 9264 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9265 | if (cloned_ctx) { |
9266 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9267 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9268 | } else { |
9269 | child_ctx->parent_ctx = parent_ctx; | |
9270 | child_ctx->parent_gen = parent_ctx->generation; | |
9271 | } | |
9272 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9273 | } |
9274 | ||
c5ed5145 | 9275 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9276 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9277 | |
25346b93 | 9278 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9279 | put_ctx(parent_ctx); |
ad3a37de | 9280 | |
6ab423e0 | 9281 | return ret; |
9b51f66d IM |
9282 | } |
9283 | ||
8dc85d54 PZ |
9284 | /* |
9285 | * Initialize the perf_event context in task_struct | |
9286 | */ | |
9287 | int perf_event_init_task(struct task_struct *child) | |
9288 | { | |
9289 | int ctxn, ret; | |
9290 | ||
8550d7cb ON |
9291 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9292 | mutex_init(&child->perf_event_mutex); | |
9293 | INIT_LIST_HEAD(&child->perf_event_list); | |
9294 | ||
8dc85d54 PZ |
9295 | for_each_task_context_nr(ctxn) { |
9296 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9297 | if (ret) { |
9298 | perf_event_free_task(child); | |
8dc85d54 | 9299 | return ret; |
6c72e350 | 9300 | } |
8dc85d54 PZ |
9301 | } |
9302 | ||
9303 | return 0; | |
9304 | } | |
9305 | ||
220b140b PM |
9306 | static void __init perf_event_init_all_cpus(void) |
9307 | { | |
b28ab83c | 9308 | struct swevent_htable *swhash; |
220b140b | 9309 | int cpu; |
220b140b PM |
9310 | |
9311 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9312 | swhash = &per_cpu(swevent_htable, cpu); |
9313 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9314 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9315 | } |
9316 | } | |
9317 | ||
0db0628d | 9318 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9319 | { |
108b02cf | 9320 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9321 | |
b28ab83c | 9322 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 9323 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
9324 | struct swevent_hlist *hlist; |
9325 | ||
b28ab83c PZ |
9326 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9327 | WARN_ON(!hlist); | |
9328 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9329 | } |
b28ab83c | 9330 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9331 | } |
9332 | ||
2965faa5 | 9333 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9334 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9335 | { |
108b02cf | 9336 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
9337 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
9338 | struct perf_event *event; | |
0793a61d | 9339 | |
fae3fde6 PZ |
9340 | raw_spin_lock(&ctx->lock); |
9341 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 9342 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 9343 | raw_spin_unlock(&ctx->lock); |
0793a61d | 9344 | } |
108b02cf PZ |
9345 | |
9346 | static void perf_event_exit_cpu_context(int cpu) | |
9347 | { | |
9348 | struct perf_event_context *ctx; | |
9349 | struct pmu *pmu; | |
9350 | int idx; | |
9351 | ||
9352 | idx = srcu_read_lock(&pmus_srcu); | |
9353 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9354 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9355 | |
9356 | mutex_lock(&ctx->mutex); | |
9357 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9358 | mutex_unlock(&ctx->mutex); | |
9359 | } | |
9360 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9361 | } |
9362 | ||
cdd6c482 | 9363 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9364 | { |
e3703f8c | 9365 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9366 | } |
9367 | #else | |
cdd6c482 | 9368 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9369 | #endif |
9370 | ||
c277443c PZ |
9371 | static int |
9372 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9373 | { | |
9374 | int cpu; | |
9375 | ||
9376 | for_each_online_cpu(cpu) | |
9377 | perf_event_exit_cpu(cpu); | |
9378 | ||
9379 | return NOTIFY_OK; | |
9380 | } | |
9381 | ||
9382 | /* | |
9383 | * Run the perf reboot notifier at the very last possible moment so that | |
9384 | * the generic watchdog code runs as long as possible. | |
9385 | */ | |
9386 | static struct notifier_block perf_reboot_notifier = { | |
9387 | .notifier_call = perf_reboot, | |
9388 | .priority = INT_MIN, | |
9389 | }; | |
9390 | ||
0db0628d | 9391 | static int |
0793a61d TG |
9392 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9393 | { | |
9394 | unsigned int cpu = (long)hcpu; | |
9395 | ||
4536e4d1 | 9396 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9397 | |
9398 | case CPU_UP_PREPARE: | |
cdd6c482 | 9399 | perf_event_init_cpu(cpu); |
0793a61d TG |
9400 | break; |
9401 | ||
9402 | case CPU_DOWN_PREPARE: | |
cdd6c482 | 9403 | perf_event_exit_cpu(cpu); |
0793a61d | 9404 | break; |
0793a61d TG |
9405 | default: |
9406 | break; | |
9407 | } | |
9408 | ||
9409 | return NOTIFY_OK; | |
9410 | } | |
9411 | ||
cdd6c482 | 9412 | void __init perf_event_init(void) |
0793a61d | 9413 | { |
3c502e7a JW |
9414 | int ret; |
9415 | ||
2e80a82a PZ |
9416 | idr_init(&pmu_idr); |
9417 | ||
220b140b | 9418 | perf_event_init_all_cpus(); |
b0a873eb | 9419 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9420 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9421 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9422 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9423 | perf_tp_register(); |
9424 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9425 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9426 | |
9427 | ret = init_hw_breakpoint(); | |
9428 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 9429 | |
b01c3a00 JO |
9430 | /* |
9431 | * Build time assertion that we keep the data_head at the intended | |
9432 | * location. IOW, validation we got the __reserved[] size right. | |
9433 | */ | |
9434 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9435 | != 1024); | |
0793a61d | 9436 | } |
abe43400 | 9437 | |
fd979c01 CS |
9438 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9439 | char *page) | |
9440 | { | |
9441 | struct perf_pmu_events_attr *pmu_attr = | |
9442 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9443 | ||
9444 | if (pmu_attr->event_str) | |
9445 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9446 | ||
9447 | return 0; | |
9448 | } | |
9449 | ||
abe43400 PZ |
9450 | static int __init perf_event_sysfs_init(void) |
9451 | { | |
9452 | struct pmu *pmu; | |
9453 | int ret; | |
9454 | ||
9455 | mutex_lock(&pmus_lock); | |
9456 | ||
9457 | ret = bus_register(&pmu_bus); | |
9458 | if (ret) | |
9459 | goto unlock; | |
9460 | ||
9461 | list_for_each_entry(pmu, &pmus, entry) { | |
9462 | if (!pmu->name || pmu->type < 0) | |
9463 | continue; | |
9464 | ||
9465 | ret = pmu_dev_alloc(pmu); | |
9466 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9467 | } | |
9468 | pmu_bus_running = 1; | |
9469 | ret = 0; | |
9470 | ||
9471 | unlock: | |
9472 | mutex_unlock(&pmus_lock); | |
9473 | ||
9474 | return ret; | |
9475 | } | |
9476 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9477 | |
9478 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9479 | static struct cgroup_subsys_state * |
9480 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9481 | { |
9482 | struct perf_cgroup *jc; | |
e5d1367f | 9483 | |
1b15d055 | 9484 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9485 | if (!jc) |
9486 | return ERR_PTR(-ENOMEM); | |
9487 | ||
e5d1367f SE |
9488 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9489 | if (!jc->info) { | |
9490 | kfree(jc); | |
9491 | return ERR_PTR(-ENOMEM); | |
9492 | } | |
9493 | ||
e5d1367f SE |
9494 | return &jc->css; |
9495 | } | |
9496 | ||
eb95419b | 9497 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9498 | { |
eb95419b TH |
9499 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9500 | ||
e5d1367f SE |
9501 | free_percpu(jc->info); |
9502 | kfree(jc); | |
9503 | } | |
9504 | ||
9505 | static int __perf_cgroup_move(void *info) | |
9506 | { | |
9507 | struct task_struct *task = info; | |
ddaaf4e2 | 9508 | rcu_read_lock(); |
e5d1367f | 9509 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9510 | rcu_read_unlock(); |
e5d1367f SE |
9511 | return 0; |
9512 | } | |
9513 | ||
1f7dd3e5 | 9514 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9515 | { |
bb9d97b6 | 9516 | struct task_struct *task; |
1f7dd3e5 | 9517 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9518 | |
1f7dd3e5 | 9519 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9520 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9521 | } |
9522 | ||
073219e9 | 9523 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9524 | .css_alloc = perf_cgroup_css_alloc, |
9525 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9526 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9527 | }; |
9528 | #endif /* CONFIG_CGROUP_PERF */ |