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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> | |
375637bc AS |
47 | #include <linux/namei.h> |
48 | #include <linux/parser.h> | |
e6017571 | 49 | #include <linux/sched/clock.h> |
6e84f315 | 50 | #include <linux/sched/mm.h> |
e4222673 HB |
51 | #include <linux/proc_ns.h> |
52 | #include <linux/mount.h> | |
0793a61d | 53 | |
76369139 FW |
54 | #include "internal.h" |
55 | ||
4e193bd4 TB |
56 | #include <asm/irq_regs.h> |
57 | ||
272325c4 PZ |
58 | typedef int (*remote_function_f)(void *); |
59 | ||
fe4b04fa | 60 | struct remote_function_call { |
e7e7ee2e | 61 | struct task_struct *p; |
272325c4 | 62 | remote_function_f func; |
e7e7ee2e IM |
63 | void *info; |
64 | int ret; | |
fe4b04fa PZ |
65 | }; |
66 | ||
67 | static void remote_function(void *data) | |
68 | { | |
69 | struct remote_function_call *tfc = data; | |
70 | struct task_struct *p = tfc->p; | |
71 | ||
72 | if (p) { | |
0da4cf3e PZ |
73 | /* -EAGAIN */ |
74 | if (task_cpu(p) != smp_processor_id()) | |
75 | return; | |
76 | ||
77 | /* | |
78 | * Now that we're on right CPU with IRQs disabled, we can test | |
79 | * if we hit the right task without races. | |
80 | */ | |
81 | ||
82 | tfc->ret = -ESRCH; /* No such (running) process */ | |
83 | if (p != current) | |
fe4b04fa PZ |
84 | return; |
85 | } | |
86 | ||
87 | tfc->ret = tfc->func(tfc->info); | |
88 | } | |
89 | ||
90 | /** | |
91 | * task_function_call - call a function on the cpu on which a task runs | |
92 | * @p: the task to evaluate | |
93 | * @func: the function to be called | |
94 | * @info: the function call argument | |
95 | * | |
96 | * Calls the function @func when the task is currently running. This might | |
97 | * be on the current CPU, which just calls the function directly | |
98 | * | |
99 | * returns: @func return value, or | |
100 | * -ESRCH - when the process isn't running | |
101 | * -EAGAIN - when the process moved away | |
102 | */ | |
103 | static int | |
272325c4 | 104 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
105 | { |
106 | struct remote_function_call data = { | |
e7e7ee2e IM |
107 | .p = p, |
108 | .func = func, | |
109 | .info = info, | |
0da4cf3e | 110 | .ret = -EAGAIN, |
fe4b04fa | 111 | }; |
0da4cf3e | 112 | int ret; |
fe4b04fa | 113 | |
0da4cf3e PZ |
114 | do { |
115 | ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
116 | if (!ret) | |
117 | ret = data.ret; | |
118 | } while (ret == -EAGAIN); | |
fe4b04fa | 119 | |
0da4cf3e | 120 | return ret; |
fe4b04fa PZ |
121 | } |
122 | ||
123 | /** | |
124 | * cpu_function_call - call a function on the cpu | |
125 | * @func: the function to be called | |
126 | * @info: the function call argument | |
127 | * | |
128 | * Calls the function @func on the remote cpu. | |
129 | * | |
130 | * returns: @func return value or -ENXIO when the cpu is offline | |
131 | */ | |
272325c4 | 132 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
133 | { |
134 | struct remote_function_call data = { | |
e7e7ee2e IM |
135 | .p = NULL, |
136 | .func = func, | |
137 | .info = info, | |
138 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
139 | }; |
140 | ||
141 | smp_call_function_single(cpu, remote_function, &data, 1); | |
142 | ||
143 | return data.ret; | |
144 | } | |
145 | ||
fae3fde6 PZ |
146 | static inline struct perf_cpu_context * |
147 | __get_cpu_context(struct perf_event_context *ctx) | |
148 | { | |
149 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
150 | } | |
151 | ||
152 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, | |
153 | struct perf_event_context *ctx) | |
0017960f | 154 | { |
fae3fde6 PZ |
155 | raw_spin_lock(&cpuctx->ctx.lock); |
156 | if (ctx) | |
157 | raw_spin_lock(&ctx->lock); | |
158 | } | |
159 | ||
160 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
161 | struct perf_event_context *ctx) | |
162 | { | |
163 | if (ctx) | |
164 | raw_spin_unlock(&ctx->lock); | |
165 | raw_spin_unlock(&cpuctx->ctx.lock); | |
166 | } | |
167 | ||
63b6da39 PZ |
168 | #define TASK_TOMBSTONE ((void *)-1L) |
169 | ||
170 | static bool is_kernel_event(struct perf_event *event) | |
171 | { | |
f47c02c0 | 172 | return READ_ONCE(event->owner) == TASK_TOMBSTONE; |
63b6da39 PZ |
173 | } |
174 | ||
39a43640 PZ |
175 | /* |
176 | * On task ctx scheduling... | |
177 | * | |
178 | * When !ctx->nr_events a task context will not be scheduled. This means | |
179 | * we can disable the scheduler hooks (for performance) without leaving | |
180 | * pending task ctx state. | |
181 | * | |
182 | * This however results in two special cases: | |
183 | * | |
184 | * - removing the last event from a task ctx; this is relatively straight | |
185 | * forward and is done in __perf_remove_from_context. | |
186 | * | |
187 | * - adding the first event to a task ctx; this is tricky because we cannot | |
188 | * rely on ctx->is_active and therefore cannot use event_function_call(). | |
189 | * See perf_install_in_context(). | |
190 | * | |
39a43640 PZ |
191 | * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. |
192 | */ | |
193 | ||
fae3fde6 PZ |
194 | typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, |
195 | struct perf_event_context *, void *); | |
196 | ||
197 | struct event_function_struct { | |
198 | struct perf_event *event; | |
199 | event_f func; | |
200 | void *data; | |
201 | }; | |
202 | ||
203 | static int event_function(void *info) | |
204 | { | |
205 | struct event_function_struct *efs = info; | |
206 | struct perf_event *event = efs->event; | |
0017960f | 207 | struct perf_event_context *ctx = event->ctx; |
fae3fde6 PZ |
208 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
209 | struct perf_event_context *task_ctx = cpuctx->task_ctx; | |
63b6da39 | 210 | int ret = 0; |
fae3fde6 PZ |
211 | |
212 | WARN_ON_ONCE(!irqs_disabled()); | |
213 | ||
63b6da39 | 214 | perf_ctx_lock(cpuctx, task_ctx); |
fae3fde6 PZ |
215 | /* |
216 | * Since we do the IPI call without holding ctx->lock things can have | |
217 | * changed, double check we hit the task we set out to hit. | |
fae3fde6 PZ |
218 | */ |
219 | if (ctx->task) { | |
63b6da39 | 220 | if (ctx->task != current) { |
0da4cf3e | 221 | ret = -ESRCH; |
63b6da39 PZ |
222 | goto unlock; |
223 | } | |
fae3fde6 | 224 | |
fae3fde6 PZ |
225 | /* |
226 | * We only use event_function_call() on established contexts, | |
227 | * and event_function() is only ever called when active (or | |
228 | * rather, we'll have bailed in task_function_call() or the | |
229 | * above ctx->task != current test), therefore we must have | |
230 | * ctx->is_active here. | |
231 | */ | |
232 | WARN_ON_ONCE(!ctx->is_active); | |
233 | /* | |
234 | * And since we have ctx->is_active, cpuctx->task_ctx must | |
235 | * match. | |
236 | */ | |
63b6da39 PZ |
237 | WARN_ON_ONCE(task_ctx != ctx); |
238 | } else { | |
239 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
fae3fde6 | 240 | } |
63b6da39 | 241 | |
fae3fde6 | 242 | efs->func(event, cpuctx, ctx, efs->data); |
63b6da39 | 243 | unlock: |
fae3fde6 PZ |
244 | perf_ctx_unlock(cpuctx, task_ctx); |
245 | ||
63b6da39 | 246 | return ret; |
fae3fde6 PZ |
247 | } |
248 | ||
fae3fde6 | 249 | static void event_function_call(struct perf_event *event, event_f func, void *data) |
0017960f PZ |
250 | { |
251 | struct perf_event_context *ctx = event->ctx; | |
63b6da39 | 252 | struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ |
fae3fde6 PZ |
253 | struct event_function_struct efs = { |
254 | .event = event, | |
255 | .func = func, | |
256 | .data = data, | |
257 | }; | |
0017960f | 258 | |
c97f4736 PZ |
259 | if (!event->parent) { |
260 | /* | |
261 | * If this is a !child event, we must hold ctx::mutex to | |
262 | * stabilize the the event->ctx relation. See | |
263 | * perf_event_ctx_lock(). | |
264 | */ | |
265 | lockdep_assert_held(&ctx->mutex); | |
266 | } | |
0017960f PZ |
267 | |
268 | if (!task) { | |
fae3fde6 | 269 | cpu_function_call(event->cpu, event_function, &efs); |
0017960f PZ |
270 | return; |
271 | } | |
272 | ||
63b6da39 PZ |
273 | if (task == TASK_TOMBSTONE) |
274 | return; | |
275 | ||
a096309b | 276 | again: |
fae3fde6 | 277 | if (!task_function_call(task, event_function, &efs)) |
0017960f PZ |
278 | return; |
279 | ||
280 | raw_spin_lock_irq(&ctx->lock); | |
63b6da39 PZ |
281 | /* |
282 | * Reload the task pointer, it might have been changed by | |
283 | * a concurrent perf_event_context_sched_out(). | |
284 | */ | |
285 | task = ctx->task; | |
a096309b PZ |
286 | if (task == TASK_TOMBSTONE) { |
287 | raw_spin_unlock_irq(&ctx->lock); | |
288 | return; | |
0017960f | 289 | } |
a096309b PZ |
290 | if (ctx->is_active) { |
291 | raw_spin_unlock_irq(&ctx->lock); | |
292 | goto again; | |
293 | } | |
294 | func(event, NULL, ctx, data); | |
0017960f PZ |
295 | raw_spin_unlock_irq(&ctx->lock); |
296 | } | |
297 | ||
cca20946 PZ |
298 | /* |
299 | * Similar to event_function_call() + event_function(), but hard assumes IRQs | |
300 | * are already disabled and we're on the right CPU. | |
301 | */ | |
302 | static void event_function_local(struct perf_event *event, event_f func, void *data) | |
303 | { | |
304 | struct perf_event_context *ctx = event->ctx; | |
305 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
306 | struct task_struct *task = READ_ONCE(ctx->task); | |
307 | struct perf_event_context *task_ctx = NULL; | |
308 | ||
309 | WARN_ON_ONCE(!irqs_disabled()); | |
310 | ||
311 | if (task) { | |
312 | if (task == TASK_TOMBSTONE) | |
313 | return; | |
314 | ||
315 | task_ctx = ctx; | |
316 | } | |
317 | ||
318 | perf_ctx_lock(cpuctx, task_ctx); | |
319 | ||
320 | task = ctx->task; | |
321 | if (task == TASK_TOMBSTONE) | |
322 | goto unlock; | |
323 | ||
324 | if (task) { | |
325 | /* | |
326 | * We must be either inactive or active and the right task, | |
327 | * otherwise we're screwed, since we cannot IPI to somewhere | |
328 | * else. | |
329 | */ | |
330 | if (ctx->is_active) { | |
331 | if (WARN_ON_ONCE(task != current)) | |
332 | goto unlock; | |
333 | ||
334 | if (WARN_ON_ONCE(cpuctx->task_ctx != ctx)) | |
335 | goto unlock; | |
336 | } | |
337 | } else { | |
338 | WARN_ON_ONCE(&cpuctx->ctx != ctx); | |
339 | } | |
340 | ||
341 | func(event, cpuctx, ctx, data); | |
342 | unlock: | |
343 | perf_ctx_unlock(cpuctx, task_ctx); | |
344 | } | |
345 | ||
e5d1367f SE |
346 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
347 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
348 | PERF_FLAG_PID_CGROUP |\ |
349 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 350 | |
bce38cd5 SE |
351 | /* |
352 | * branch priv levels that need permission checks | |
353 | */ | |
354 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
355 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
356 | PERF_SAMPLE_BRANCH_HV) | |
357 | ||
0b3fcf17 SE |
358 | enum event_type_t { |
359 | EVENT_FLEXIBLE = 0x1, | |
360 | EVENT_PINNED = 0x2, | |
3cbaa590 | 361 | EVENT_TIME = 0x4, |
487f05e1 AS |
362 | /* see ctx_resched() for details */ |
363 | EVENT_CPU = 0x8, | |
0b3fcf17 SE |
364 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
365 | }; | |
366 | ||
e5d1367f SE |
367 | /* |
368 | * perf_sched_events : >0 events exist | |
369 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
370 | */ | |
9107c89e PZ |
371 | |
372 | static void perf_sched_delayed(struct work_struct *work); | |
373 | DEFINE_STATIC_KEY_FALSE(perf_sched_events); | |
374 | static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed); | |
375 | static DEFINE_MUTEX(perf_sched_mutex); | |
376 | static atomic_t perf_sched_count; | |
377 | ||
e5d1367f | 378 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 379 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
f2fb6bef | 380 | static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events); |
e5d1367f | 381 | |
cdd6c482 IM |
382 | static atomic_t nr_mmap_events __read_mostly; |
383 | static atomic_t nr_comm_events __read_mostly; | |
e4222673 | 384 | static atomic_t nr_namespaces_events __read_mostly; |
cdd6c482 | 385 | static atomic_t nr_task_events __read_mostly; |
948b26b6 | 386 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 387 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 388 | |
108b02cf PZ |
389 | static LIST_HEAD(pmus); |
390 | static DEFINE_MUTEX(pmus_lock); | |
391 | static struct srcu_struct pmus_srcu; | |
a63fbed7 | 392 | static cpumask_var_t perf_online_mask; |
108b02cf | 393 | |
0764771d | 394 | /* |
cdd6c482 | 395 | * perf event paranoia level: |
0fbdea19 IM |
396 | * -1 - not paranoid at all |
397 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 398 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 399 | * 2 - disallow kernel profiling for unpriv |
0764771d | 400 | */ |
0161028b | 401 | int sysctl_perf_event_paranoid __read_mostly = 2; |
0764771d | 402 | |
20443384 FW |
403 | /* Minimum for 512 kiB + 1 user control page */ |
404 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
405 | |
406 | /* | |
cdd6c482 | 407 | * max perf event sample rate |
df58ab24 | 408 | */ |
14c63f17 DH |
409 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
410 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
411 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
412 | ||
413 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
414 | ||
415 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
416 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
417 | ||
d9494cb4 PZ |
418 | static int perf_sample_allowed_ns __read_mostly = |
419 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 420 | |
18ab2cd3 | 421 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
422 | { |
423 | u64 tmp = perf_sample_period_ns; | |
424 | ||
425 | tmp *= sysctl_perf_cpu_time_max_percent; | |
91a612ee PZ |
426 | tmp = div_u64(tmp, 100); |
427 | if (!tmp) | |
428 | tmp = 1; | |
429 | ||
430 | WRITE_ONCE(perf_sample_allowed_ns, tmp); | |
14c63f17 | 431 | } |
163ec435 | 432 | |
9e630205 SE |
433 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
434 | ||
163ec435 PZ |
435 | int perf_proc_update_handler(struct ctl_table *table, int write, |
436 | void __user *buffer, size_t *lenp, | |
437 | loff_t *ppos) | |
438 | { | |
723478c8 | 439 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
440 | |
441 | if (ret || !write) | |
442 | return ret; | |
443 | ||
ab7fdefb KL |
444 | /* |
445 | * If throttling is disabled don't allow the write: | |
446 | */ | |
447 | if (sysctl_perf_cpu_time_max_percent == 100 || | |
448 | sysctl_perf_cpu_time_max_percent == 0) | |
449 | return -EINVAL; | |
450 | ||
163ec435 | 451 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); |
14c63f17 DH |
452 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
453 | update_perf_cpu_limits(); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | ||
458 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
459 | ||
460 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
461 | void __user *buffer, size_t *lenp, | |
462 | loff_t *ppos) | |
463 | { | |
1572e45a | 464 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
14c63f17 DH |
465 | |
466 | if (ret || !write) | |
467 | return ret; | |
468 | ||
b303e7c1 PZ |
469 | if (sysctl_perf_cpu_time_max_percent == 100 || |
470 | sysctl_perf_cpu_time_max_percent == 0) { | |
91a612ee PZ |
471 | printk(KERN_WARNING |
472 | "perf: Dynamic interrupt throttling disabled, can hang your system!\n"); | |
473 | WRITE_ONCE(perf_sample_allowed_ns, 0); | |
474 | } else { | |
475 | update_perf_cpu_limits(); | |
476 | } | |
163ec435 PZ |
477 | |
478 | return 0; | |
479 | } | |
1ccd1549 | 480 | |
14c63f17 DH |
481 | /* |
482 | * perf samples are done in some very critical code paths (NMIs). | |
483 | * If they take too much CPU time, the system can lock up and not | |
484 | * get any real work done. This will drop the sample rate when | |
485 | * we detect that events are taking too long. | |
486 | */ | |
487 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 488 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 489 | |
91a612ee PZ |
490 | static u64 __report_avg; |
491 | static u64 __report_allowed; | |
492 | ||
6a02ad66 | 493 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 494 | { |
0d87d7ec | 495 | printk_ratelimited(KERN_INFO |
91a612ee PZ |
496 | "perf: interrupt took too long (%lld > %lld), lowering " |
497 | "kernel.perf_event_max_sample_rate to %d\n", | |
498 | __report_avg, __report_allowed, | |
499 | sysctl_perf_event_sample_rate); | |
6a02ad66 PZ |
500 | } |
501 | ||
502 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
503 | ||
504 | void perf_sample_event_took(u64 sample_len_ns) | |
505 | { | |
91a612ee PZ |
506 | u64 max_len = READ_ONCE(perf_sample_allowed_ns); |
507 | u64 running_len; | |
508 | u64 avg_len; | |
509 | u32 max; | |
14c63f17 | 510 | |
91a612ee | 511 | if (max_len == 0) |
14c63f17 DH |
512 | return; |
513 | ||
91a612ee PZ |
514 | /* Decay the counter by 1 average sample. */ |
515 | running_len = __this_cpu_read(running_sample_length); | |
516 | running_len -= running_len/NR_ACCUMULATED_SAMPLES; | |
517 | running_len += sample_len_ns; | |
518 | __this_cpu_write(running_sample_length, running_len); | |
14c63f17 DH |
519 | |
520 | /* | |
91a612ee PZ |
521 | * Note: this will be biased artifically low until we have |
522 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
14c63f17 DH |
523 | * from having to maintain a count. |
524 | */ | |
91a612ee PZ |
525 | avg_len = running_len/NR_ACCUMULATED_SAMPLES; |
526 | if (avg_len <= max_len) | |
14c63f17 DH |
527 | return; |
528 | ||
91a612ee PZ |
529 | __report_avg = avg_len; |
530 | __report_allowed = max_len; | |
14c63f17 | 531 | |
91a612ee PZ |
532 | /* |
533 | * Compute a throttle threshold 25% below the current duration. | |
534 | */ | |
535 | avg_len += avg_len / 4; | |
536 | max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent; | |
537 | if (avg_len < max) | |
538 | max /= (u32)avg_len; | |
539 | else | |
540 | max = 1; | |
14c63f17 | 541 | |
91a612ee PZ |
542 | WRITE_ONCE(perf_sample_allowed_ns, avg_len); |
543 | WRITE_ONCE(max_samples_per_tick, max); | |
544 | ||
545 | sysctl_perf_event_sample_rate = max * HZ; | |
546 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
6a02ad66 | 547 | |
cd578abb | 548 | if (!irq_work_queue(&perf_duration_work)) { |
91a612ee | 549 | early_printk("perf: interrupt took too long (%lld > %lld), lowering " |
cd578abb | 550 | "kernel.perf_event_max_sample_rate to %d\n", |
91a612ee | 551 | __report_avg, __report_allowed, |
cd578abb PZ |
552 | sysctl_perf_event_sample_rate); |
553 | } | |
14c63f17 DH |
554 | } |
555 | ||
cdd6c482 | 556 | static atomic64_t perf_event_id; |
a96bbc16 | 557 | |
0b3fcf17 SE |
558 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
559 | enum event_type_t event_type); | |
560 | ||
561 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
562 | enum event_type_t event_type, |
563 | struct task_struct *task); | |
564 | ||
565 | static void update_context_time(struct perf_event_context *ctx); | |
566 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 567 | |
cdd6c482 | 568 | void __weak perf_event_print_debug(void) { } |
0793a61d | 569 | |
84c79910 | 570 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 571 | { |
84c79910 | 572 | return "pmu"; |
0793a61d TG |
573 | } |
574 | ||
0b3fcf17 SE |
575 | static inline u64 perf_clock(void) |
576 | { | |
577 | return local_clock(); | |
578 | } | |
579 | ||
34f43927 PZ |
580 | static inline u64 perf_event_clock(struct perf_event *event) |
581 | { | |
582 | return event->clock(); | |
583 | } | |
584 | ||
e5d1367f SE |
585 | #ifdef CONFIG_CGROUP_PERF |
586 | ||
e5d1367f SE |
587 | static inline bool |
588 | perf_cgroup_match(struct perf_event *event) | |
589 | { | |
590 | struct perf_event_context *ctx = event->ctx; | |
591 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
592 | ||
ef824fa1 TH |
593 | /* @event doesn't care about cgroup */ |
594 | if (!event->cgrp) | |
595 | return true; | |
596 | ||
597 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
598 | if (!cpuctx->cgrp) | |
599 | return false; | |
600 | ||
601 | /* | |
602 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
603 | * also enabled for all its descendant cgroups. If @cpuctx's | |
604 | * cgroup is a descendant of @event's (the test covers identity | |
605 | * case), it's a match. | |
606 | */ | |
607 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
608 | event->cgrp->css.cgroup); | |
e5d1367f SE |
609 | } |
610 | ||
e5d1367f SE |
611 | static inline void perf_detach_cgroup(struct perf_event *event) |
612 | { | |
4e2ba650 | 613 | css_put(&event->cgrp->css); |
e5d1367f SE |
614 | event->cgrp = NULL; |
615 | } | |
616 | ||
617 | static inline int is_cgroup_event(struct perf_event *event) | |
618 | { | |
619 | return event->cgrp != NULL; | |
620 | } | |
621 | ||
622 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
623 | { | |
624 | struct perf_cgroup_info *t; | |
625 | ||
626 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
627 | return t->time; | |
628 | } | |
629 | ||
630 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
631 | { | |
632 | struct perf_cgroup_info *info; | |
633 | u64 now; | |
634 | ||
635 | now = perf_clock(); | |
636 | ||
637 | info = this_cpu_ptr(cgrp->info); | |
638 | ||
639 | info->time += now - info->timestamp; | |
640 | info->timestamp = now; | |
641 | } | |
642 | ||
643 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
644 | { | |
645 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
646 | if (cgrp_out) | |
647 | __update_cgrp_time(cgrp_out); | |
648 | } | |
649 | ||
650 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
651 | { | |
3f7cce3c SE |
652 | struct perf_cgroup *cgrp; |
653 | ||
e5d1367f | 654 | /* |
3f7cce3c SE |
655 | * ensure we access cgroup data only when needed and |
656 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 657 | */ |
3f7cce3c | 658 | if (!is_cgroup_event(event)) |
e5d1367f SE |
659 | return; |
660 | ||
614e4c4e | 661 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
662 | /* |
663 | * Do not update time when cgroup is not active | |
664 | */ | |
665 | if (cgrp == event->cgrp) | |
666 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
667 | } |
668 | ||
669 | static inline void | |
3f7cce3c SE |
670 | perf_cgroup_set_timestamp(struct task_struct *task, |
671 | struct perf_event_context *ctx) | |
e5d1367f SE |
672 | { |
673 | struct perf_cgroup *cgrp; | |
674 | struct perf_cgroup_info *info; | |
675 | ||
3f7cce3c SE |
676 | /* |
677 | * ctx->lock held by caller | |
678 | * ensure we do not access cgroup data | |
679 | * unless we have the cgroup pinned (css_get) | |
680 | */ | |
681 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
682 | return; |
683 | ||
614e4c4e | 684 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 685 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 686 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
687 | } |
688 | ||
058fe1c0 DCC |
689 | static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list); |
690 | ||
e5d1367f SE |
691 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ |
692 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
693 | ||
694 | /* | |
695 | * reschedule events based on the cgroup constraint of task. | |
696 | * | |
697 | * mode SWOUT : schedule out everything | |
698 | * mode SWIN : schedule in based on cgroup for next | |
699 | */ | |
18ab2cd3 | 700 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
701 | { |
702 | struct perf_cpu_context *cpuctx; | |
058fe1c0 | 703 | struct list_head *list; |
e5d1367f SE |
704 | unsigned long flags; |
705 | ||
706 | /* | |
058fe1c0 DCC |
707 | * Disable interrupts and preemption to avoid this CPU's |
708 | * cgrp_cpuctx_entry to change under us. | |
e5d1367f SE |
709 | */ |
710 | local_irq_save(flags); | |
711 | ||
058fe1c0 DCC |
712 | list = this_cpu_ptr(&cgrp_cpuctx_list); |
713 | list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) { | |
714 | WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0); | |
e5d1367f | 715 | |
058fe1c0 DCC |
716 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
717 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f | 718 | |
058fe1c0 DCC |
719 | if (mode & PERF_CGROUP_SWOUT) { |
720 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
721 | /* | |
722 | * must not be done before ctxswout due | |
723 | * to event_filter_match() in event_sched_out() | |
724 | */ | |
725 | cpuctx->cgrp = NULL; | |
726 | } | |
e5d1367f | 727 | |
058fe1c0 DCC |
728 | if (mode & PERF_CGROUP_SWIN) { |
729 | WARN_ON_ONCE(cpuctx->cgrp); | |
730 | /* | |
731 | * set cgrp before ctxsw in to allow | |
732 | * event_filter_match() to not have to pass | |
733 | * task around | |
734 | * we pass the cpuctx->ctx to perf_cgroup_from_task() | |
735 | * because cgorup events are only per-cpu | |
736 | */ | |
737 | cpuctx->cgrp = perf_cgroup_from_task(task, | |
738 | &cpuctx->ctx); | |
739 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); | |
e5d1367f | 740 | } |
058fe1c0 DCC |
741 | perf_pmu_enable(cpuctx->ctx.pmu); |
742 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f SE |
743 | } |
744 | ||
e5d1367f SE |
745 | local_irq_restore(flags); |
746 | } | |
747 | ||
a8d757ef SE |
748 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
749 | struct task_struct *next) | |
e5d1367f | 750 | { |
a8d757ef SE |
751 | struct perf_cgroup *cgrp1; |
752 | struct perf_cgroup *cgrp2 = NULL; | |
753 | ||
ddaaf4e2 | 754 | rcu_read_lock(); |
a8d757ef SE |
755 | /* |
756 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
757 | * we do not need to pass the ctx here because we know |
758 | * we are holding the rcu lock | |
a8d757ef | 759 | */ |
614e4c4e | 760 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 761 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
762 | |
763 | /* | |
764 | * only schedule out current cgroup events if we know | |
765 | * that we are switching to a different cgroup. Otherwise, | |
766 | * do no touch the cgroup events. | |
767 | */ | |
768 | if (cgrp1 != cgrp2) | |
769 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
770 | |
771 | rcu_read_unlock(); | |
e5d1367f SE |
772 | } |
773 | ||
a8d757ef SE |
774 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
775 | struct task_struct *task) | |
e5d1367f | 776 | { |
a8d757ef SE |
777 | struct perf_cgroup *cgrp1; |
778 | struct perf_cgroup *cgrp2 = NULL; | |
779 | ||
ddaaf4e2 | 780 | rcu_read_lock(); |
a8d757ef SE |
781 | /* |
782 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
783 | * we do not need to pass the ctx here because we know |
784 | * we are holding the rcu lock | |
a8d757ef | 785 | */ |
614e4c4e | 786 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 787 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
788 | |
789 | /* | |
790 | * only need to schedule in cgroup events if we are changing | |
791 | * cgroup during ctxsw. Cgroup events were not scheduled | |
792 | * out of ctxsw out if that was not the case. | |
793 | */ | |
794 | if (cgrp1 != cgrp2) | |
795 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
796 | |
797 | rcu_read_unlock(); | |
e5d1367f SE |
798 | } |
799 | ||
800 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
801 | struct perf_event_attr *attr, | |
802 | struct perf_event *group_leader) | |
803 | { | |
804 | struct perf_cgroup *cgrp; | |
805 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
806 | struct fd f = fdget(fd); |
807 | int ret = 0; | |
e5d1367f | 808 | |
2903ff01 | 809 | if (!f.file) |
e5d1367f SE |
810 | return -EBADF; |
811 | ||
b583043e | 812 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 813 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
814 | if (IS_ERR(css)) { |
815 | ret = PTR_ERR(css); | |
816 | goto out; | |
817 | } | |
e5d1367f SE |
818 | |
819 | cgrp = container_of(css, struct perf_cgroup, css); | |
820 | event->cgrp = cgrp; | |
821 | ||
822 | /* | |
823 | * all events in a group must monitor | |
824 | * the same cgroup because a task belongs | |
825 | * to only one perf cgroup at a time | |
826 | */ | |
827 | if (group_leader && group_leader->cgrp != cgrp) { | |
828 | perf_detach_cgroup(event); | |
829 | ret = -EINVAL; | |
e5d1367f | 830 | } |
3db272c0 | 831 | out: |
2903ff01 | 832 | fdput(f); |
e5d1367f SE |
833 | return ret; |
834 | } | |
835 | ||
836 | static inline void | |
837 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
838 | { | |
839 | struct perf_cgroup_info *t; | |
840 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
841 | event->shadow_ctx_time = now - t->timestamp; | |
842 | } | |
843 | ||
844 | static inline void | |
845 | perf_cgroup_defer_enabled(struct perf_event *event) | |
846 | { | |
847 | /* | |
848 | * when the current task's perf cgroup does not match | |
849 | * the event's, we need to remember to call the | |
850 | * perf_mark_enable() function the first time a task with | |
851 | * a matching perf cgroup is scheduled in. | |
852 | */ | |
853 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
854 | event->cgrp_defer_enabled = 1; | |
855 | } | |
856 | ||
857 | static inline void | |
858 | perf_cgroup_mark_enabled(struct perf_event *event, | |
859 | struct perf_event_context *ctx) | |
860 | { | |
861 | struct perf_event *sub; | |
862 | u64 tstamp = perf_event_time(event); | |
863 | ||
864 | if (!event->cgrp_defer_enabled) | |
865 | return; | |
866 | ||
867 | event->cgrp_defer_enabled = 0; | |
868 | ||
869 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
870 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
871 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
872 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
873 | sub->cgrp_defer_enabled = 0; | |
874 | } | |
875 | } | |
876 | } | |
db4a8356 DCC |
877 | |
878 | /* | |
879 | * Update cpuctx->cgrp so that it is set when first cgroup event is added and | |
880 | * cleared when last cgroup event is removed. | |
881 | */ | |
882 | static inline void | |
883 | list_update_cgroup_event(struct perf_event *event, | |
884 | struct perf_event_context *ctx, bool add) | |
885 | { | |
886 | struct perf_cpu_context *cpuctx; | |
058fe1c0 | 887 | struct list_head *cpuctx_entry; |
db4a8356 DCC |
888 | |
889 | if (!is_cgroup_event(event)) | |
890 | return; | |
891 | ||
892 | if (add && ctx->nr_cgroups++) | |
893 | return; | |
894 | else if (!add && --ctx->nr_cgroups) | |
895 | return; | |
896 | /* | |
897 | * Because cgroup events are always per-cpu events, | |
898 | * this will always be called from the right CPU. | |
899 | */ | |
900 | cpuctx = __get_cpu_context(ctx); | |
058fe1c0 DCC |
901 | cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; |
902 | /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/ | |
903 | if (add) { | |
904 | list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); | |
905 | if (perf_cgroup_from_task(current, ctx) == event->cgrp) | |
906 | cpuctx->cgrp = event->cgrp; | |
907 | } else { | |
908 | list_del(cpuctx_entry); | |
8fc31ce8 | 909 | cpuctx->cgrp = NULL; |
058fe1c0 | 910 | } |
db4a8356 DCC |
911 | } |
912 | ||
e5d1367f SE |
913 | #else /* !CONFIG_CGROUP_PERF */ |
914 | ||
915 | static inline bool | |
916 | perf_cgroup_match(struct perf_event *event) | |
917 | { | |
918 | return true; | |
919 | } | |
920 | ||
921 | static inline void perf_detach_cgroup(struct perf_event *event) | |
922 | {} | |
923 | ||
924 | static inline int is_cgroup_event(struct perf_event *event) | |
925 | { | |
926 | return 0; | |
927 | } | |
928 | ||
e5d1367f SE |
929 | static inline void update_cgrp_time_from_event(struct perf_event *event) |
930 | { | |
931 | } | |
932 | ||
933 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
934 | { | |
935 | } | |
936 | ||
a8d757ef SE |
937 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
938 | struct task_struct *next) | |
e5d1367f SE |
939 | { |
940 | } | |
941 | ||
a8d757ef SE |
942 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
943 | struct task_struct *task) | |
e5d1367f SE |
944 | { |
945 | } | |
946 | ||
947 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
948 | struct perf_event_attr *attr, | |
949 | struct perf_event *group_leader) | |
950 | { | |
951 | return -EINVAL; | |
952 | } | |
953 | ||
954 | static inline void | |
3f7cce3c SE |
955 | perf_cgroup_set_timestamp(struct task_struct *task, |
956 | struct perf_event_context *ctx) | |
e5d1367f SE |
957 | { |
958 | } | |
959 | ||
960 | void | |
961 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
962 | { | |
963 | } | |
964 | ||
965 | static inline void | |
966 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
967 | { | |
968 | } | |
969 | ||
970 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
971 | { | |
972 | return 0; | |
973 | } | |
974 | ||
975 | static inline void | |
976 | perf_cgroup_defer_enabled(struct perf_event *event) | |
977 | { | |
978 | } | |
979 | ||
980 | static inline void | |
981 | perf_cgroup_mark_enabled(struct perf_event *event, | |
982 | struct perf_event_context *ctx) | |
983 | { | |
984 | } | |
db4a8356 DCC |
985 | |
986 | static inline void | |
987 | list_update_cgroup_event(struct perf_event *event, | |
988 | struct perf_event_context *ctx, bool add) | |
989 | { | |
990 | } | |
991 | ||
e5d1367f SE |
992 | #endif |
993 | ||
9e630205 SE |
994 | /* |
995 | * set default to be dependent on timer tick just | |
996 | * like original code | |
997 | */ | |
998 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
999 | /* | |
8a1115ff | 1000 | * function must be called with interrupts disabled |
9e630205 | 1001 | */ |
272325c4 | 1002 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
1003 | { |
1004 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
1005 | int rotations = 0; |
1006 | ||
1007 | WARN_ON(!irqs_disabled()); | |
1008 | ||
1009 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
1010 | rotations = perf_rotate_context(cpuctx); |
1011 | ||
4cfafd30 PZ |
1012 | raw_spin_lock(&cpuctx->hrtimer_lock); |
1013 | if (rotations) | |
9e630205 | 1014 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
1015 | else |
1016 | cpuctx->hrtimer_active = 0; | |
1017 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 1018 | |
4cfafd30 | 1019 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
1020 | } |
1021 | ||
272325c4 | 1022 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 1023 | { |
272325c4 | 1024 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 1025 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 1026 | u64 interval; |
9e630205 SE |
1027 | |
1028 | /* no multiplexing needed for SW PMU */ | |
1029 | if (pmu->task_ctx_nr == perf_sw_context) | |
1030 | return; | |
1031 | ||
62b85639 SE |
1032 | /* |
1033 | * check default is sane, if not set then force to | |
1034 | * default interval (1/tick) | |
1035 | */ | |
272325c4 PZ |
1036 | interval = pmu->hrtimer_interval_ms; |
1037 | if (interval < 1) | |
1038 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 1039 | |
272325c4 | 1040 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 1041 | |
4cfafd30 PZ |
1042 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
1043 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 1044 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
1045 | } |
1046 | ||
272325c4 | 1047 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 1048 | { |
272325c4 | 1049 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 1050 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 1051 | unsigned long flags; |
9e630205 SE |
1052 | |
1053 | /* not for SW PMU */ | |
1054 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 1055 | return 0; |
9e630205 | 1056 | |
4cfafd30 PZ |
1057 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
1058 | if (!cpuctx->hrtimer_active) { | |
1059 | cpuctx->hrtimer_active = 1; | |
1060 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
1061 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
1062 | } | |
1063 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 1064 | |
272325c4 | 1065 | return 0; |
9e630205 SE |
1066 | } |
1067 | ||
33696fc0 | 1068 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 1069 | { |
33696fc0 PZ |
1070 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
1071 | if (!(*count)++) | |
1072 | pmu->pmu_disable(pmu); | |
9e35ad38 | 1073 | } |
9e35ad38 | 1074 | |
33696fc0 | 1075 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 1076 | { |
33696fc0 PZ |
1077 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
1078 | if (!--(*count)) | |
1079 | pmu->pmu_enable(pmu); | |
9e35ad38 | 1080 | } |
9e35ad38 | 1081 | |
2fde4f94 | 1082 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
1083 | |
1084 | /* | |
2fde4f94 MR |
1085 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
1086 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
1087 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
1088 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 1089 | */ |
2fde4f94 | 1090 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 1091 | { |
2fde4f94 | 1092 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 1093 | |
e9d2b064 | 1094 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 1095 | |
2fde4f94 MR |
1096 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
1097 | ||
1098 | list_add(&ctx->active_ctx_list, head); | |
1099 | } | |
1100 | ||
1101 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
1102 | { | |
1103 | WARN_ON(!irqs_disabled()); | |
1104 | ||
1105 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
1106 | ||
1107 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 1108 | } |
9e35ad38 | 1109 | |
cdd6c482 | 1110 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1111 | { |
e5289d4a | 1112 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
1113 | } |
1114 | ||
4af57ef2 YZ |
1115 | static void free_ctx(struct rcu_head *head) |
1116 | { | |
1117 | struct perf_event_context *ctx; | |
1118 | ||
1119 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
1120 | kfree(ctx->task_ctx_data); | |
1121 | kfree(ctx); | |
1122 | } | |
1123 | ||
cdd6c482 | 1124 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 1125 | { |
564c2b21 PM |
1126 | if (atomic_dec_and_test(&ctx->refcount)) { |
1127 | if (ctx->parent_ctx) | |
1128 | put_ctx(ctx->parent_ctx); | |
63b6da39 | 1129 | if (ctx->task && ctx->task != TASK_TOMBSTONE) |
c93f7669 | 1130 | put_task_struct(ctx->task); |
4af57ef2 | 1131 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 1132 | } |
a63eaf34 PM |
1133 | } |
1134 | ||
f63a8daa PZ |
1135 | /* |
1136 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
1137 | * perf_pmu_migrate_context() we need some magic. | |
1138 | * | |
1139 | * Those places that change perf_event::ctx will hold both | |
1140 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
1141 | * | |
8b10c5e2 PZ |
1142 | * Lock ordering is by mutex address. There are two other sites where |
1143 | * perf_event_context::mutex nests and those are: | |
1144 | * | |
1145 | * - perf_event_exit_task_context() [ child , 0 ] | |
8ba289b8 PZ |
1146 | * perf_event_exit_event() |
1147 | * put_event() [ parent, 1 ] | |
8b10c5e2 PZ |
1148 | * |
1149 | * - perf_event_init_context() [ parent, 0 ] | |
1150 | * inherit_task_group() | |
1151 | * inherit_group() | |
1152 | * inherit_event() | |
1153 | * perf_event_alloc() | |
1154 | * perf_init_event() | |
1155 | * perf_try_init_event() [ child , 1 ] | |
1156 | * | |
1157 | * While it appears there is an obvious deadlock here -- the parent and child | |
1158 | * nesting levels are inverted between the two. This is in fact safe because | |
1159 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
1160 | * spawning task cannot (yet) exit. | |
1161 | * | |
1162 | * But remember that that these are parent<->child context relations, and | |
1163 | * migration does not affect children, therefore these two orderings should not | |
1164 | * interact. | |
f63a8daa PZ |
1165 | * |
1166 | * The change in perf_event::ctx does not affect children (as claimed above) | |
1167 | * because the sys_perf_event_open() case will install a new event and break | |
1168 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
1169 | * concerned with cpuctx and that doesn't have children. | |
1170 | * | |
1171 | * The places that change perf_event::ctx will issue: | |
1172 | * | |
1173 | * perf_remove_from_context(); | |
1174 | * synchronize_rcu(); | |
1175 | * perf_install_in_context(); | |
1176 | * | |
1177 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
1178 | * quiesce the event, after which we can install it in the new location. This | |
1179 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
1180 | * while in transit. Therefore all such accessors should also acquire | |
1181 | * perf_event_context::mutex to serialize against this. | |
1182 | * | |
1183 | * However; because event->ctx can change while we're waiting to acquire | |
1184 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
1185 | * function. | |
1186 | * | |
1187 | * Lock order: | |
79c9ce57 | 1188 | * cred_guard_mutex |
f63a8daa PZ |
1189 | * task_struct::perf_event_mutex |
1190 | * perf_event_context::mutex | |
f63a8daa | 1191 | * perf_event::child_mutex; |
07c4a776 | 1192 | * perf_event_context::lock |
f63a8daa PZ |
1193 | * perf_event::mmap_mutex |
1194 | * mmap_sem | |
1195 | */ | |
a83fe28e PZ |
1196 | static struct perf_event_context * |
1197 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
1198 | { |
1199 | struct perf_event_context *ctx; | |
1200 | ||
1201 | again: | |
1202 | rcu_read_lock(); | |
1203 | ctx = ACCESS_ONCE(event->ctx); | |
1204 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
1205 | rcu_read_unlock(); | |
1206 | goto again; | |
1207 | } | |
1208 | rcu_read_unlock(); | |
1209 | ||
a83fe28e | 1210 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1211 | if (event->ctx != ctx) { |
1212 | mutex_unlock(&ctx->mutex); | |
1213 | put_ctx(ctx); | |
1214 | goto again; | |
1215 | } | |
1216 | ||
1217 | return ctx; | |
1218 | } | |
1219 | ||
a83fe28e PZ |
1220 | static inline struct perf_event_context * |
1221 | perf_event_ctx_lock(struct perf_event *event) | |
1222 | { | |
1223 | return perf_event_ctx_lock_nested(event, 0); | |
1224 | } | |
1225 | ||
f63a8daa PZ |
1226 | static void perf_event_ctx_unlock(struct perf_event *event, |
1227 | struct perf_event_context *ctx) | |
1228 | { | |
1229 | mutex_unlock(&ctx->mutex); | |
1230 | put_ctx(ctx); | |
1231 | } | |
1232 | ||
211de6eb PZ |
1233 | /* |
1234 | * This must be done under the ctx->lock, such as to serialize against | |
1235 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1236 | * calling scheduler related locks and ctx->lock nests inside those. | |
1237 | */ | |
1238 | static __must_check struct perf_event_context * | |
1239 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1240 | { |
211de6eb PZ |
1241 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1242 | ||
1243 | lockdep_assert_held(&ctx->lock); | |
1244 | ||
1245 | if (parent_ctx) | |
71a851b4 | 1246 | ctx->parent_ctx = NULL; |
5a3126d4 | 1247 | ctx->generation++; |
211de6eb PZ |
1248 | |
1249 | return parent_ctx; | |
71a851b4 PZ |
1250 | } |
1251 | ||
6844c09d ACM |
1252 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1253 | { | |
1254 | /* | |
1255 | * only top level events have the pid namespace they were created in | |
1256 | */ | |
1257 | if (event->parent) | |
1258 | event = event->parent; | |
1259 | ||
1260 | return task_tgid_nr_ns(p, event->ns); | |
1261 | } | |
1262 | ||
1263 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1264 | { | |
1265 | /* | |
1266 | * only top level events have the pid namespace they were created in | |
1267 | */ | |
1268 | if (event->parent) | |
1269 | event = event->parent; | |
1270 | ||
1271 | return task_pid_nr_ns(p, event->ns); | |
1272 | } | |
1273 | ||
7f453c24 | 1274 | /* |
cdd6c482 | 1275 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1276 | * to userspace. |
1277 | */ | |
cdd6c482 | 1278 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1279 | { |
cdd6c482 | 1280 | u64 id = event->id; |
7f453c24 | 1281 | |
cdd6c482 IM |
1282 | if (event->parent) |
1283 | id = event->parent->id; | |
7f453c24 PZ |
1284 | |
1285 | return id; | |
1286 | } | |
1287 | ||
25346b93 | 1288 | /* |
cdd6c482 | 1289 | * Get the perf_event_context for a task and lock it. |
63b6da39 | 1290 | * |
25346b93 PM |
1291 | * This has to cope with with the fact that until it is locked, |
1292 | * the context could get moved to another task. | |
1293 | */ | |
cdd6c482 | 1294 | static struct perf_event_context * |
8dc85d54 | 1295 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1296 | { |
cdd6c482 | 1297 | struct perf_event_context *ctx; |
25346b93 | 1298 | |
9ed6060d | 1299 | retry: |
058ebd0e PZ |
1300 | /* |
1301 | * One of the few rules of preemptible RCU is that one cannot do | |
1302 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1303 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1304 | * rcu_read_unlock_special(). |
1305 | * | |
1306 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1307 | * side critical section has interrupts disabled. |
058ebd0e | 1308 | */ |
2fd59077 | 1309 | local_irq_save(*flags); |
058ebd0e | 1310 | rcu_read_lock(); |
8dc85d54 | 1311 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1312 | if (ctx) { |
1313 | /* | |
1314 | * If this context is a clone of another, it might | |
1315 | * get swapped for another underneath us by | |
cdd6c482 | 1316 | * perf_event_task_sched_out, though the |
25346b93 PM |
1317 | * rcu_read_lock() protects us from any context |
1318 | * getting freed. Lock the context and check if it | |
1319 | * got swapped before we could get the lock, and retry | |
1320 | * if so. If we locked the right context, then it | |
1321 | * can't get swapped on us any more. | |
1322 | */ | |
2fd59077 | 1323 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1324 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1325 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1326 | rcu_read_unlock(); |
2fd59077 | 1327 | local_irq_restore(*flags); |
25346b93 PM |
1328 | goto retry; |
1329 | } | |
b49a9e7e | 1330 | |
63b6da39 PZ |
1331 | if (ctx->task == TASK_TOMBSTONE || |
1332 | !atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1333 | raw_spin_unlock(&ctx->lock); |
b49a9e7e | 1334 | ctx = NULL; |
828b6f0e PZ |
1335 | } else { |
1336 | WARN_ON_ONCE(ctx->task != task); | |
b49a9e7e | 1337 | } |
25346b93 PM |
1338 | } |
1339 | rcu_read_unlock(); | |
2fd59077 PM |
1340 | if (!ctx) |
1341 | local_irq_restore(*flags); | |
25346b93 PM |
1342 | return ctx; |
1343 | } | |
1344 | ||
1345 | /* | |
1346 | * Get the context for a task and increment its pin_count so it | |
1347 | * can't get swapped to another task. This also increments its | |
1348 | * reference count so that the context can't get freed. | |
1349 | */ | |
8dc85d54 PZ |
1350 | static struct perf_event_context * |
1351 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1352 | { |
cdd6c482 | 1353 | struct perf_event_context *ctx; |
25346b93 PM |
1354 | unsigned long flags; |
1355 | ||
8dc85d54 | 1356 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1357 | if (ctx) { |
1358 | ++ctx->pin_count; | |
e625cce1 | 1359 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1360 | } |
1361 | return ctx; | |
1362 | } | |
1363 | ||
cdd6c482 | 1364 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1365 | { |
1366 | unsigned long flags; | |
1367 | ||
e625cce1 | 1368 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1369 | --ctx->pin_count; |
e625cce1 | 1370 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1371 | } |
1372 | ||
f67218c3 PZ |
1373 | /* |
1374 | * Update the record of the current time in a context. | |
1375 | */ | |
1376 | static void update_context_time(struct perf_event_context *ctx) | |
1377 | { | |
1378 | u64 now = perf_clock(); | |
1379 | ||
1380 | ctx->time += now - ctx->timestamp; | |
1381 | ctx->timestamp = now; | |
1382 | } | |
1383 | ||
4158755d SE |
1384 | static u64 perf_event_time(struct perf_event *event) |
1385 | { | |
1386 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1387 | |
1388 | if (is_cgroup_event(event)) | |
1389 | return perf_cgroup_event_time(event); | |
1390 | ||
4158755d SE |
1391 | return ctx ? ctx->time : 0; |
1392 | } | |
1393 | ||
f67218c3 PZ |
1394 | /* |
1395 | * Update the total_time_enabled and total_time_running fields for a event. | |
1396 | */ | |
1397 | static void update_event_times(struct perf_event *event) | |
1398 | { | |
1399 | struct perf_event_context *ctx = event->ctx; | |
1400 | u64 run_end; | |
1401 | ||
3cbaa590 PZ |
1402 | lockdep_assert_held(&ctx->lock); |
1403 | ||
f67218c3 PZ |
1404 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
1405 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1406 | return; | |
3cbaa590 | 1407 | |
e5d1367f SE |
1408 | /* |
1409 | * in cgroup mode, time_enabled represents | |
1410 | * the time the event was enabled AND active | |
1411 | * tasks were in the monitored cgroup. This is | |
1412 | * independent of the activity of the context as | |
1413 | * there may be a mix of cgroup and non-cgroup events. | |
1414 | * | |
1415 | * That is why we treat cgroup events differently | |
1416 | * here. | |
1417 | */ | |
1418 | if (is_cgroup_event(event)) | |
46cd6a7f | 1419 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1420 | else if (ctx->is_active) |
1421 | run_end = ctx->time; | |
acd1d7c1 PZ |
1422 | else |
1423 | run_end = event->tstamp_stopped; | |
1424 | ||
1425 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1426 | |
1427 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1428 | run_end = event->tstamp_stopped; | |
1429 | else | |
4158755d | 1430 | run_end = perf_event_time(event); |
f67218c3 PZ |
1431 | |
1432 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1433 | |
f67218c3 PZ |
1434 | } |
1435 | ||
96c21a46 PZ |
1436 | /* |
1437 | * Update total_time_enabled and total_time_running for all events in a group. | |
1438 | */ | |
1439 | static void update_group_times(struct perf_event *leader) | |
1440 | { | |
1441 | struct perf_event *event; | |
1442 | ||
1443 | update_event_times(leader); | |
1444 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1445 | update_event_times(event); | |
1446 | } | |
1447 | ||
487f05e1 AS |
1448 | static enum event_type_t get_event_type(struct perf_event *event) |
1449 | { | |
1450 | struct perf_event_context *ctx = event->ctx; | |
1451 | enum event_type_t event_type; | |
1452 | ||
1453 | lockdep_assert_held(&ctx->lock); | |
1454 | ||
1455 | event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE; | |
1456 | if (!ctx->task) | |
1457 | event_type |= EVENT_CPU; | |
1458 | ||
1459 | return event_type; | |
1460 | } | |
1461 | ||
889ff015 FW |
1462 | static struct list_head * |
1463 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1464 | { | |
1465 | if (event->attr.pinned) | |
1466 | return &ctx->pinned_groups; | |
1467 | else | |
1468 | return &ctx->flexible_groups; | |
1469 | } | |
1470 | ||
fccc714b | 1471 | /* |
cdd6c482 | 1472 | * Add a event from the lists for its context. |
fccc714b PZ |
1473 | * Must be called with ctx->mutex and ctx->lock held. |
1474 | */ | |
04289bb9 | 1475 | static void |
cdd6c482 | 1476 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1477 | { |
c994d613 PZ |
1478 | lockdep_assert_held(&ctx->lock); |
1479 | ||
8a49542c PZ |
1480 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1481 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1482 | |
1483 | /* | |
8a49542c PZ |
1484 | * If we're a stand alone event or group leader, we go to the context |
1485 | * list, group events are kept attached to the group so that | |
1486 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1487 | */ |
8a49542c | 1488 | if (event->group_leader == event) { |
889ff015 FW |
1489 | struct list_head *list; |
1490 | ||
4ff6a8de | 1491 | event->group_caps = event->event_caps; |
d6f962b5 | 1492 | |
889ff015 FW |
1493 | list = ctx_group_list(event, ctx); |
1494 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1495 | } |
592903cd | 1496 | |
db4a8356 | 1497 | list_update_cgroup_event(event, ctx, true); |
e5d1367f | 1498 | |
cdd6c482 IM |
1499 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1500 | ctx->nr_events++; | |
1501 | if (event->attr.inherit_stat) | |
bfbd3381 | 1502 | ctx->nr_stat++; |
5a3126d4 PZ |
1503 | |
1504 | ctx->generation++; | |
04289bb9 IM |
1505 | } |
1506 | ||
0231bb53 JO |
1507 | /* |
1508 | * Initialize event state based on the perf_event_attr::disabled. | |
1509 | */ | |
1510 | static inline void perf_event__state_init(struct perf_event *event) | |
1511 | { | |
1512 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1513 | PERF_EVENT_STATE_INACTIVE; | |
1514 | } | |
1515 | ||
a723968c | 1516 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1517 | { |
1518 | int entry = sizeof(u64); /* value */ | |
1519 | int size = 0; | |
1520 | int nr = 1; | |
1521 | ||
1522 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1523 | size += sizeof(u64); | |
1524 | ||
1525 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1526 | size += sizeof(u64); | |
1527 | ||
1528 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1529 | entry += sizeof(u64); | |
1530 | ||
1531 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1532 | nr += nr_siblings; |
c320c7b7 ACM |
1533 | size += sizeof(u64); |
1534 | } | |
1535 | ||
1536 | size += entry * nr; | |
1537 | event->read_size = size; | |
1538 | } | |
1539 | ||
a723968c | 1540 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1541 | { |
1542 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1543 | u16 size = 0; |
1544 | ||
c320c7b7 ACM |
1545 | if (sample_type & PERF_SAMPLE_IP) |
1546 | size += sizeof(data->ip); | |
1547 | ||
6844c09d ACM |
1548 | if (sample_type & PERF_SAMPLE_ADDR) |
1549 | size += sizeof(data->addr); | |
1550 | ||
1551 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1552 | size += sizeof(data->period); | |
1553 | ||
c3feedf2 AK |
1554 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1555 | size += sizeof(data->weight); | |
1556 | ||
6844c09d ACM |
1557 | if (sample_type & PERF_SAMPLE_READ) |
1558 | size += event->read_size; | |
1559 | ||
d6be9ad6 SE |
1560 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1561 | size += sizeof(data->data_src.val); | |
1562 | ||
fdfbbd07 AK |
1563 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1564 | size += sizeof(data->txn); | |
1565 | ||
6844c09d ACM |
1566 | event->header_size = size; |
1567 | } | |
1568 | ||
a723968c PZ |
1569 | /* |
1570 | * Called at perf_event creation and when events are attached/detached from a | |
1571 | * group. | |
1572 | */ | |
1573 | static void perf_event__header_size(struct perf_event *event) | |
1574 | { | |
1575 | __perf_event_read_size(event, | |
1576 | event->group_leader->nr_siblings); | |
1577 | __perf_event_header_size(event, event->attr.sample_type); | |
1578 | } | |
1579 | ||
6844c09d ACM |
1580 | static void perf_event__id_header_size(struct perf_event *event) |
1581 | { | |
1582 | struct perf_sample_data *data; | |
1583 | u64 sample_type = event->attr.sample_type; | |
1584 | u16 size = 0; | |
1585 | ||
c320c7b7 ACM |
1586 | if (sample_type & PERF_SAMPLE_TID) |
1587 | size += sizeof(data->tid_entry); | |
1588 | ||
1589 | if (sample_type & PERF_SAMPLE_TIME) | |
1590 | size += sizeof(data->time); | |
1591 | ||
ff3d527c AH |
1592 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1593 | size += sizeof(data->id); | |
1594 | ||
c320c7b7 ACM |
1595 | if (sample_type & PERF_SAMPLE_ID) |
1596 | size += sizeof(data->id); | |
1597 | ||
1598 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1599 | size += sizeof(data->stream_id); | |
1600 | ||
1601 | if (sample_type & PERF_SAMPLE_CPU) | |
1602 | size += sizeof(data->cpu_entry); | |
1603 | ||
6844c09d | 1604 | event->id_header_size = size; |
c320c7b7 ACM |
1605 | } |
1606 | ||
a723968c PZ |
1607 | static bool perf_event_validate_size(struct perf_event *event) |
1608 | { | |
1609 | /* | |
1610 | * The values computed here will be over-written when we actually | |
1611 | * attach the event. | |
1612 | */ | |
1613 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1614 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1615 | perf_event__id_header_size(event); | |
1616 | ||
1617 | /* | |
1618 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1619 | * Conservative limit to allow for callchains and other variable fields. | |
1620 | */ | |
1621 | if (event->read_size + event->header_size + | |
1622 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1623 | return false; | |
1624 | ||
1625 | return true; | |
1626 | } | |
1627 | ||
8a49542c PZ |
1628 | static void perf_group_attach(struct perf_event *event) |
1629 | { | |
c320c7b7 | 1630 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1631 | |
a76a82a3 PZ |
1632 | lockdep_assert_held(&event->ctx->lock); |
1633 | ||
74c3337c PZ |
1634 | /* |
1635 | * We can have double attach due to group movement in perf_event_open. | |
1636 | */ | |
1637 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1638 | return; | |
1639 | ||
8a49542c PZ |
1640 | event->attach_state |= PERF_ATTACH_GROUP; |
1641 | ||
1642 | if (group_leader == event) | |
1643 | return; | |
1644 | ||
652884fe PZ |
1645 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1646 | ||
4ff6a8de | 1647 | group_leader->group_caps &= event->event_caps; |
8a49542c PZ |
1648 | |
1649 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1650 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1651 | |
1652 | perf_event__header_size(group_leader); | |
1653 | ||
1654 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1655 | perf_event__header_size(pos); | |
8a49542c PZ |
1656 | } |
1657 | ||
a63eaf34 | 1658 | /* |
cdd6c482 | 1659 | * Remove a event from the lists for its context. |
fccc714b | 1660 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1661 | */ |
04289bb9 | 1662 | static void |
cdd6c482 | 1663 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1664 | { |
652884fe PZ |
1665 | WARN_ON_ONCE(event->ctx != ctx); |
1666 | lockdep_assert_held(&ctx->lock); | |
1667 | ||
8a49542c PZ |
1668 | /* |
1669 | * We can have double detach due to exit/hot-unplug + close. | |
1670 | */ | |
1671 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1672 | return; |
8a49542c PZ |
1673 | |
1674 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1675 | ||
db4a8356 | 1676 | list_update_cgroup_event(event, ctx, false); |
e5d1367f | 1677 | |
cdd6c482 IM |
1678 | ctx->nr_events--; |
1679 | if (event->attr.inherit_stat) | |
bfbd3381 | 1680 | ctx->nr_stat--; |
8bc20959 | 1681 | |
cdd6c482 | 1682 | list_del_rcu(&event->event_entry); |
04289bb9 | 1683 | |
8a49542c PZ |
1684 | if (event->group_leader == event) |
1685 | list_del_init(&event->group_entry); | |
5c148194 | 1686 | |
96c21a46 | 1687 | update_group_times(event); |
b2e74a26 SE |
1688 | |
1689 | /* | |
1690 | * If event was in error state, then keep it | |
1691 | * that way, otherwise bogus counts will be | |
1692 | * returned on read(). The only way to get out | |
1693 | * of error state is by explicit re-enabling | |
1694 | * of the event | |
1695 | */ | |
1696 | if (event->state > PERF_EVENT_STATE_OFF) | |
1697 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1698 | |
1699 | ctx->generation++; | |
050735b0 PZ |
1700 | } |
1701 | ||
8a49542c | 1702 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1703 | { |
1704 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1705 | struct list_head *list = NULL; |
1706 | ||
a76a82a3 PZ |
1707 | lockdep_assert_held(&event->ctx->lock); |
1708 | ||
8a49542c PZ |
1709 | /* |
1710 | * We can have double detach due to exit/hot-unplug + close. | |
1711 | */ | |
1712 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1713 | return; | |
1714 | ||
1715 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1716 | ||
1717 | /* | |
1718 | * If this is a sibling, remove it from its group. | |
1719 | */ | |
1720 | if (event->group_leader != event) { | |
1721 | list_del_init(&event->group_entry); | |
1722 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1723 | goto out; |
8a49542c PZ |
1724 | } |
1725 | ||
1726 | if (!list_empty(&event->group_entry)) | |
1727 | list = &event->group_entry; | |
2e2af50b | 1728 | |
04289bb9 | 1729 | /* |
cdd6c482 IM |
1730 | * If this was a group event with sibling events then |
1731 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1732 | * to whatever list we are on. |
04289bb9 | 1733 | */ |
cdd6c482 | 1734 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1735 | if (list) |
1736 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1737 | sibling->group_leader = sibling; |
d6f962b5 FW |
1738 | |
1739 | /* Inherit group flags from the previous leader */ | |
4ff6a8de | 1740 | sibling->group_caps = event->group_caps; |
652884fe PZ |
1741 | |
1742 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1743 | } |
c320c7b7 ACM |
1744 | |
1745 | out: | |
1746 | perf_event__header_size(event->group_leader); | |
1747 | ||
1748 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1749 | perf_event__header_size(tmp); | |
04289bb9 IM |
1750 | } |
1751 | ||
fadfe7be JO |
1752 | static bool is_orphaned_event(struct perf_event *event) |
1753 | { | |
a69b0ca4 | 1754 | return event->state == PERF_EVENT_STATE_DEAD; |
fadfe7be JO |
1755 | } |
1756 | ||
2c81a647 | 1757 | static inline int __pmu_filter_match(struct perf_event *event) |
66eb579e MR |
1758 | { |
1759 | struct pmu *pmu = event->pmu; | |
1760 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1761 | } | |
1762 | ||
2c81a647 MR |
1763 | /* |
1764 | * Check whether we should attempt to schedule an event group based on | |
1765 | * PMU-specific filtering. An event group can consist of HW and SW events, | |
1766 | * potentially with a SW leader, so we must check all the filters, to | |
1767 | * determine whether a group is schedulable: | |
1768 | */ | |
1769 | static inline int pmu_filter_match(struct perf_event *event) | |
1770 | { | |
1771 | struct perf_event *child; | |
1772 | ||
1773 | if (!__pmu_filter_match(event)) | |
1774 | return 0; | |
1775 | ||
1776 | list_for_each_entry(child, &event->sibling_list, group_entry) { | |
1777 | if (!__pmu_filter_match(child)) | |
1778 | return 0; | |
1779 | } | |
1780 | ||
1781 | return 1; | |
1782 | } | |
1783 | ||
fa66f07a SE |
1784 | static inline int |
1785 | event_filter_match(struct perf_event *event) | |
1786 | { | |
0b8f1e2e PZ |
1787 | return (event->cpu == -1 || event->cpu == smp_processor_id()) && |
1788 | perf_cgroup_match(event) && pmu_filter_match(event); | |
fa66f07a SE |
1789 | } |
1790 | ||
9ffcfa6f SE |
1791 | static void |
1792 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1793 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1794 | struct perf_event_context *ctx) |
3b6f9e5c | 1795 | { |
4158755d | 1796 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1797 | u64 delta; |
652884fe PZ |
1798 | |
1799 | WARN_ON_ONCE(event->ctx != ctx); | |
1800 | lockdep_assert_held(&ctx->lock); | |
1801 | ||
fa66f07a SE |
1802 | /* |
1803 | * An event which could not be activated because of | |
1804 | * filter mismatch still needs to have its timings | |
1805 | * maintained, otherwise bogus information is return | |
1806 | * via read() for time_enabled, time_running: | |
1807 | */ | |
0b8f1e2e PZ |
1808 | if (event->state == PERF_EVENT_STATE_INACTIVE && |
1809 | !event_filter_match(event)) { | |
e5d1367f | 1810 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1811 | event->tstamp_running += delta; |
4158755d | 1812 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1813 | } |
1814 | ||
cdd6c482 | 1815 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1816 | return; |
3b6f9e5c | 1817 | |
44377277 AS |
1818 | perf_pmu_disable(event->pmu); |
1819 | ||
28a967c3 PZ |
1820 | event->tstamp_stopped = tstamp; |
1821 | event->pmu->del(event, 0); | |
1822 | event->oncpu = -1; | |
cdd6c482 IM |
1823 | event->state = PERF_EVENT_STATE_INACTIVE; |
1824 | if (event->pending_disable) { | |
1825 | event->pending_disable = 0; | |
1826 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1827 | } |
3b6f9e5c | 1828 | |
cdd6c482 | 1829 | if (!is_software_event(event)) |
3b6f9e5c | 1830 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1831 | if (!--ctx->nr_active) |
1832 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1833 | if (event->attr.freq && event->attr.sample_freq) |
1834 | ctx->nr_freq--; | |
cdd6c482 | 1835 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1836 | cpuctx->exclusive = 0; |
44377277 AS |
1837 | |
1838 | perf_pmu_enable(event->pmu); | |
3b6f9e5c PM |
1839 | } |
1840 | ||
d859e29f | 1841 | static void |
cdd6c482 | 1842 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1843 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1844 | struct perf_event_context *ctx) |
d859e29f | 1845 | { |
cdd6c482 | 1846 | struct perf_event *event; |
fa66f07a | 1847 | int state = group_event->state; |
d859e29f | 1848 | |
3f005e7d MR |
1849 | perf_pmu_disable(ctx->pmu); |
1850 | ||
cdd6c482 | 1851 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1852 | |
1853 | /* | |
1854 | * Schedule out siblings (if any): | |
1855 | */ | |
cdd6c482 IM |
1856 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1857 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1858 | |
3f005e7d MR |
1859 | perf_pmu_enable(ctx->pmu); |
1860 | ||
fa66f07a | 1861 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1862 | cpuctx->exclusive = 0; |
1863 | } | |
1864 | ||
45a0e07a | 1865 | #define DETACH_GROUP 0x01UL |
0017960f | 1866 | |
0793a61d | 1867 | /* |
cdd6c482 | 1868 | * Cross CPU call to remove a performance event |
0793a61d | 1869 | * |
cdd6c482 | 1870 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1871 | * remove it from the context list. |
1872 | */ | |
fae3fde6 PZ |
1873 | static void |
1874 | __perf_remove_from_context(struct perf_event *event, | |
1875 | struct perf_cpu_context *cpuctx, | |
1876 | struct perf_event_context *ctx, | |
1877 | void *info) | |
0793a61d | 1878 | { |
45a0e07a | 1879 | unsigned long flags = (unsigned long)info; |
0793a61d | 1880 | |
cdd6c482 | 1881 | event_sched_out(event, cpuctx, ctx); |
45a0e07a | 1882 | if (flags & DETACH_GROUP) |
46ce0fe9 | 1883 | perf_group_detach(event); |
cdd6c482 | 1884 | list_del_event(event, ctx); |
39a43640 PZ |
1885 | |
1886 | if (!ctx->nr_events && ctx->is_active) { | |
64ce3126 | 1887 | ctx->is_active = 0; |
39a43640 PZ |
1888 | if (ctx->task) { |
1889 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
1890 | cpuctx->task_ctx = NULL; | |
1891 | } | |
64ce3126 | 1892 | } |
0793a61d TG |
1893 | } |
1894 | ||
0793a61d | 1895 | /* |
cdd6c482 | 1896 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1897 | * |
cdd6c482 IM |
1898 | * If event->ctx is a cloned context, callers must make sure that |
1899 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1900 | * remains valid. This is OK when called from perf_release since |
1901 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1902 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1903 | * context has been detached from its task. |
0793a61d | 1904 | */ |
45a0e07a | 1905 | static void perf_remove_from_context(struct perf_event *event, unsigned long flags) |
0793a61d | 1906 | { |
a76a82a3 PZ |
1907 | struct perf_event_context *ctx = event->ctx; |
1908 | ||
1909 | lockdep_assert_held(&ctx->mutex); | |
0793a61d | 1910 | |
45a0e07a | 1911 | event_function_call(event, __perf_remove_from_context, (void *)flags); |
a76a82a3 PZ |
1912 | |
1913 | /* | |
1914 | * The above event_function_call() can NO-OP when it hits | |
1915 | * TASK_TOMBSTONE. In that case we must already have been detached | |
1916 | * from the context (by perf_event_exit_event()) but the grouping | |
1917 | * might still be in-tact. | |
1918 | */ | |
1919 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); | |
1920 | if ((flags & DETACH_GROUP) && | |
1921 | (event->attach_state & PERF_ATTACH_GROUP)) { | |
1922 | /* | |
1923 | * Since in that case we cannot possibly be scheduled, simply | |
1924 | * detach now. | |
1925 | */ | |
1926 | raw_spin_lock_irq(&ctx->lock); | |
1927 | perf_group_detach(event); | |
1928 | raw_spin_unlock_irq(&ctx->lock); | |
1929 | } | |
0793a61d TG |
1930 | } |
1931 | ||
d859e29f | 1932 | /* |
cdd6c482 | 1933 | * Cross CPU call to disable a performance event |
d859e29f | 1934 | */ |
fae3fde6 PZ |
1935 | static void __perf_event_disable(struct perf_event *event, |
1936 | struct perf_cpu_context *cpuctx, | |
1937 | struct perf_event_context *ctx, | |
1938 | void *info) | |
7b648018 | 1939 | { |
fae3fde6 PZ |
1940 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
1941 | return; | |
7b648018 | 1942 | |
fae3fde6 PZ |
1943 | update_context_time(ctx); |
1944 | update_cgrp_time_from_event(event); | |
1945 | update_group_times(event); | |
1946 | if (event == event->group_leader) | |
1947 | group_sched_out(event, cpuctx, ctx); | |
1948 | else | |
1949 | event_sched_out(event, cpuctx, ctx); | |
1950 | event->state = PERF_EVENT_STATE_OFF; | |
7b648018 PZ |
1951 | } |
1952 | ||
d859e29f | 1953 | /* |
cdd6c482 | 1954 | * Disable a event. |
c93f7669 | 1955 | * |
cdd6c482 IM |
1956 | * If event->ctx is a cloned context, callers must make sure that |
1957 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1958 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1959 | * perf_event_for_each_child or perf_event_for_each because they |
1960 | * hold the top-level event's child_mutex, so any descendant that | |
8ba289b8 PZ |
1961 | * goes to exit will block in perf_event_exit_event(). |
1962 | * | |
cdd6c482 | 1963 | * When called from perf_pending_event it's OK because event->ctx |
c93f7669 | 1964 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1965 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1966 | */ |
f63a8daa | 1967 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1968 | { |
cdd6c482 | 1969 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1970 | |
e625cce1 | 1971 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1972 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1973 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1974 | return; |
53cfbf59 | 1975 | } |
e625cce1 | 1976 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1977 | |
fae3fde6 PZ |
1978 | event_function_call(event, __perf_event_disable, NULL); |
1979 | } | |
1980 | ||
1981 | void perf_event_disable_local(struct perf_event *event) | |
1982 | { | |
1983 | event_function_local(event, __perf_event_disable, NULL); | |
d859e29f | 1984 | } |
f63a8daa PZ |
1985 | |
1986 | /* | |
1987 | * Strictly speaking kernel users cannot create groups and therefore this | |
1988 | * interface does not need the perf_event_ctx_lock() magic. | |
1989 | */ | |
1990 | void perf_event_disable(struct perf_event *event) | |
1991 | { | |
1992 | struct perf_event_context *ctx; | |
1993 | ||
1994 | ctx = perf_event_ctx_lock(event); | |
1995 | _perf_event_disable(event); | |
1996 | perf_event_ctx_unlock(event, ctx); | |
1997 | } | |
dcfce4a0 | 1998 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1999 | |
5aab90ce JO |
2000 | void perf_event_disable_inatomic(struct perf_event *event) |
2001 | { | |
2002 | event->pending_disable = 1; | |
2003 | irq_work_queue(&event->pending); | |
2004 | } | |
2005 | ||
e5d1367f SE |
2006 | static void perf_set_shadow_time(struct perf_event *event, |
2007 | struct perf_event_context *ctx, | |
2008 | u64 tstamp) | |
2009 | { | |
2010 | /* | |
2011 | * use the correct time source for the time snapshot | |
2012 | * | |
2013 | * We could get by without this by leveraging the | |
2014 | * fact that to get to this function, the caller | |
2015 | * has most likely already called update_context_time() | |
2016 | * and update_cgrp_time_xx() and thus both timestamp | |
2017 | * are identical (or very close). Given that tstamp is, | |
2018 | * already adjusted for cgroup, we could say that: | |
2019 | * tstamp - ctx->timestamp | |
2020 | * is equivalent to | |
2021 | * tstamp - cgrp->timestamp. | |
2022 | * | |
2023 | * Then, in perf_output_read(), the calculation would | |
2024 | * work with no changes because: | |
2025 | * - event is guaranteed scheduled in | |
2026 | * - no scheduled out in between | |
2027 | * - thus the timestamp would be the same | |
2028 | * | |
2029 | * But this is a bit hairy. | |
2030 | * | |
2031 | * So instead, we have an explicit cgroup call to remain | |
2032 | * within the time time source all along. We believe it | |
2033 | * is cleaner and simpler to understand. | |
2034 | */ | |
2035 | if (is_cgroup_event(event)) | |
2036 | perf_cgroup_set_shadow_time(event, tstamp); | |
2037 | else | |
2038 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
2039 | } | |
2040 | ||
4fe757dd PZ |
2041 | #define MAX_INTERRUPTS (~0ULL) |
2042 | ||
2043 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 2044 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 2045 | |
235c7fc7 | 2046 | static int |
9ffcfa6f | 2047 | event_sched_in(struct perf_event *event, |
235c7fc7 | 2048 | struct perf_cpu_context *cpuctx, |
6e37738a | 2049 | struct perf_event_context *ctx) |
235c7fc7 | 2050 | { |
4158755d | 2051 | u64 tstamp = perf_event_time(event); |
44377277 | 2052 | int ret = 0; |
4158755d | 2053 | |
63342411 PZ |
2054 | lockdep_assert_held(&ctx->lock); |
2055 | ||
cdd6c482 | 2056 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
2057 | return 0; |
2058 | ||
95ff4ca2 AS |
2059 | WRITE_ONCE(event->oncpu, smp_processor_id()); |
2060 | /* | |
2061 | * Order event::oncpu write to happen before the ACTIVE state | |
2062 | * is visible. | |
2063 | */ | |
2064 | smp_wmb(); | |
2065 | WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE); | |
4fe757dd PZ |
2066 | |
2067 | /* | |
2068 | * Unthrottle events, since we scheduled we might have missed several | |
2069 | * ticks already, also for a heavily scheduling task there is little | |
2070 | * guarantee it'll get a tick in a timely manner. | |
2071 | */ | |
2072 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
2073 | perf_log_throttle(event, 1); | |
2074 | event->hw.interrupts = 0; | |
2075 | } | |
2076 | ||
235c7fc7 IM |
2077 | /* |
2078 | * The new state must be visible before we turn it on in the hardware: | |
2079 | */ | |
2080 | smp_wmb(); | |
2081 | ||
44377277 AS |
2082 | perf_pmu_disable(event->pmu); |
2083 | ||
72f669c0 SL |
2084 | perf_set_shadow_time(event, ctx, tstamp); |
2085 | ||
ec0d7729 AS |
2086 | perf_log_itrace_start(event); |
2087 | ||
a4eaf7f1 | 2088 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
2089 | event->state = PERF_EVENT_STATE_INACTIVE; |
2090 | event->oncpu = -1; | |
44377277 AS |
2091 | ret = -EAGAIN; |
2092 | goto out; | |
235c7fc7 IM |
2093 | } |
2094 | ||
00a2916f PZ |
2095 | event->tstamp_running += tstamp - event->tstamp_stopped; |
2096 | ||
cdd6c482 | 2097 | if (!is_software_event(event)) |
3b6f9e5c | 2098 | cpuctx->active_oncpu++; |
2fde4f94 MR |
2099 | if (!ctx->nr_active++) |
2100 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
2101 | if (event->attr.freq && event->attr.sample_freq) |
2102 | ctx->nr_freq++; | |
235c7fc7 | 2103 | |
cdd6c482 | 2104 | if (event->attr.exclusive) |
3b6f9e5c PM |
2105 | cpuctx->exclusive = 1; |
2106 | ||
44377277 AS |
2107 | out: |
2108 | perf_pmu_enable(event->pmu); | |
2109 | ||
2110 | return ret; | |
235c7fc7 IM |
2111 | } |
2112 | ||
6751b71e | 2113 | static int |
cdd6c482 | 2114 | group_sched_in(struct perf_event *group_event, |
6751b71e | 2115 | struct perf_cpu_context *cpuctx, |
6e37738a | 2116 | struct perf_event_context *ctx) |
6751b71e | 2117 | { |
6bde9b6c | 2118 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 2119 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
2120 | u64 now = ctx->time; |
2121 | bool simulate = false; | |
6751b71e | 2122 | |
cdd6c482 | 2123 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
2124 | return 0; |
2125 | ||
fbbe0701 | 2126 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 2127 | |
9ffcfa6f | 2128 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 2129 | pmu->cancel_txn(pmu); |
272325c4 | 2130 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 2131 | return -EAGAIN; |
90151c35 | 2132 | } |
6751b71e PM |
2133 | |
2134 | /* | |
2135 | * Schedule in siblings as one group (if any): | |
2136 | */ | |
cdd6c482 | 2137 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 2138 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 2139 | partial_group = event; |
6751b71e PM |
2140 | goto group_error; |
2141 | } | |
2142 | } | |
2143 | ||
9ffcfa6f | 2144 | if (!pmu->commit_txn(pmu)) |
6e85158c | 2145 | return 0; |
9ffcfa6f | 2146 | |
6751b71e PM |
2147 | group_error: |
2148 | /* | |
2149 | * Groups can be scheduled in as one unit only, so undo any | |
2150 | * partial group before returning: | |
d7842da4 SE |
2151 | * The events up to the failed event are scheduled out normally, |
2152 | * tstamp_stopped will be updated. | |
2153 | * | |
2154 | * The failed events and the remaining siblings need to have | |
2155 | * their timings updated as if they had gone thru event_sched_in() | |
2156 | * and event_sched_out(). This is required to get consistent timings | |
2157 | * across the group. This also takes care of the case where the group | |
2158 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
2159 | * the time the event was actually stopped, such that time delta | |
2160 | * calculation in update_event_times() is correct. | |
6751b71e | 2161 | */ |
cdd6c482 IM |
2162 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
2163 | if (event == partial_group) | |
d7842da4 SE |
2164 | simulate = true; |
2165 | ||
2166 | if (simulate) { | |
2167 | event->tstamp_running += now - event->tstamp_stopped; | |
2168 | event->tstamp_stopped = now; | |
2169 | } else { | |
2170 | event_sched_out(event, cpuctx, ctx); | |
2171 | } | |
6751b71e | 2172 | } |
9ffcfa6f | 2173 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 2174 | |
ad5133b7 | 2175 | pmu->cancel_txn(pmu); |
90151c35 | 2176 | |
272325c4 | 2177 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2178 | |
6751b71e PM |
2179 | return -EAGAIN; |
2180 | } | |
2181 | ||
3b6f9e5c | 2182 | /* |
cdd6c482 | 2183 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2184 | */ |
cdd6c482 | 2185 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2186 | struct perf_cpu_context *cpuctx, |
2187 | int can_add_hw) | |
2188 | { | |
2189 | /* | |
cdd6c482 | 2190 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2191 | */ |
4ff6a8de | 2192 | if (event->group_caps & PERF_EV_CAP_SOFTWARE) |
3b6f9e5c PM |
2193 | return 1; |
2194 | /* | |
2195 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2196 | * events can go on. |
3b6f9e5c PM |
2197 | */ |
2198 | if (cpuctx->exclusive) | |
2199 | return 0; | |
2200 | /* | |
2201 | * If this group is exclusive and there are already | |
cdd6c482 | 2202 | * events on the CPU, it can't go on. |
3b6f9e5c | 2203 | */ |
cdd6c482 | 2204 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2205 | return 0; |
2206 | /* | |
2207 | * Otherwise, try to add it if all previous groups were able | |
2208 | * to go on. | |
2209 | */ | |
2210 | return can_add_hw; | |
2211 | } | |
2212 | ||
cdd6c482 IM |
2213 | static void add_event_to_ctx(struct perf_event *event, |
2214 | struct perf_event_context *ctx) | |
53cfbf59 | 2215 | { |
4158755d SE |
2216 | u64 tstamp = perf_event_time(event); |
2217 | ||
cdd6c482 | 2218 | list_add_event(event, ctx); |
8a49542c | 2219 | perf_group_attach(event); |
4158755d SE |
2220 | event->tstamp_enabled = tstamp; |
2221 | event->tstamp_running = tstamp; | |
2222 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2223 | } |
2224 | ||
bd2afa49 PZ |
2225 | static void ctx_sched_out(struct perf_event_context *ctx, |
2226 | struct perf_cpu_context *cpuctx, | |
2227 | enum event_type_t event_type); | |
2c29ef0f PZ |
2228 | static void |
2229 | ctx_sched_in(struct perf_event_context *ctx, | |
2230 | struct perf_cpu_context *cpuctx, | |
2231 | enum event_type_t event_type, | |
2232 | struct task_struct *task); | |
fe4b04fa | 2233 | |
bd2afa49 | 2234 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
487f05e1 AS |
2235 | struct perf_event_context *ctx, |
2236 | enum event_type_t event_type) | |
bd2afa49 PZ |
2237 | { |
2238 | if (!cpuctx->task_ctx) | |
2239 | return; | |
2240 | ||
2241 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2242 | return; | |
2243 | ||
487f05e1 | 2244 | ctx_sched_out(ctx, cpuctx, event_type); |
bd2afa49 PZ |
2245 | } |
2246 | ||
dce5855b PZ |
2247 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2248 | struct perf_event_context *ctx, | |
2249 | struct task_struct *task) | |
2250 | { | |
2251 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2252 | if (ctx) | |
2253 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2254 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2255 | if (ctx) | |
2256 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2257 | } | |
2258 | ||
487f05e1 AS |
2259 | /* |
2260 | * We want to maintain the following priority of scheduling: | |
2261 | * - CPU pinned (EVENT_CPU | EVENT_PINNED) | |
2262 | * - task pinned (EVENT_PINNED) | |
2263 | * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE) | |
2264 | * - task flexible (EVENT_FLEXIBLE). | |
2265 | * | |
2266 | * In order to avoid unscheduling and scheduling back in everything every | |
2267 | * time an event is added, only do it for the groups of equal priority and | |
2268 | * below. | |
2269 | * | |
2270 | * This can be called after a batch operation on task events, in which case | |
2271 | * event_type is a bit mask of the types of events involved. For CPU events, | |
2272 | * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE. | |
2273 | */ | |
3e349507 | 2274 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
487f05e1 AS |
2275 | struct perf_event_context *task_ctx, |
2276 | enum event_type_t event_type) | |
0017960f | 2277 | { |
487f05e1 AS |
2278 | enum event_type_t ctx_event_type = event_type & EVENT_ALL; |
2279 | bool cpu_event = !!(event_type & EVENT_CPU); | |
2280 | ||
2281 | /* | |
2282 | * If pinned groups are involved, flexible groups also need to be | |
2283 | * scheduled out. | |
2284 | */ | |
2285 | if (event_type & EVENT_PINNED) | |
2286 | event_type |= EVENT_FLEXIBLE; | |
2287 | ||
3e349507 PZ |
2288 | perf_pmu_disable(cpuctx->ctx.pmu); |
2289 | if (task_ctx) | |
487f05e1 AS |
2290 | task_ctx_sched_out(cpuctx, task_ctx, event_type); |
2291 | ||
2292 | /* | |
2293 | * Decide which cpu ctx groups to schedule out based on the types | |
2294 | * of events that caused rescheduling: | |
2295 | * - EVENT_CPU: schedule out corresponding groups; | |
2296 | * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups; | |
2297 | * - otherwise, do nothing more. | |
2298 | */ | |
2299 | if (cpu_event) | |
2300 | cpu_ctx_sched_out(cpuctx, ctx_event_type); | |
2301 | else if (ctx_event_type & EVENT_PINNED) | |
2302 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2303 | ||
3e349507 PZ |
2304 | perf_event_sched_in(cpuctx, task_ctx, current); |
2305 | perf_pmu_enable(cpuctx->ctx.pmu); | |
0017960f PZ |
2306 | } |
2307 | ||
0793a61d | 2308 | /* |
cdd6c482 | 2309 | * Cross CPU call to install and enable a performance event |
682076ae | 2310 | * |
a096309b PZ |
2311 | * Very similar to remote_function() + event_function() but cannot assume that |
2312 | * things like ctx->is_active and cpuctx->task_ctx are set. | |
0793a61d | 2313 | */ |
fe4b04fa | 2314 | static int __perf_install_in_context(void *info) |
0793a61d | 2315 | { |
a096309b PZ |
2316 | struct perf_event *event = info; |
2317 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2318 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f | 2319 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
63cae12b | 2320 | bool reprogram = true; |
a096309b | 2321 | int ret = 0; |
0793a61d | 2322 | |
63b6da39 | 2323 | raw_spin_lock(&cpuctx->ctx.lock); |
39a43640 | 2324 | if (ctx->task) { |
b58f6b0d PZ |
2325 | raw_spin_lock(&ctx->lock); |
2326 | task_ctx = ctx; | |
a096309b | 2327 | |
63cae12b | 2328 | reprogram = (ctx->task == current); |
b58f6b0d | 2329 | |
39a43640 | 2330 | /* |
63cae12b PZ |
2331 | * If the task is running, it must be running on this CPU, |
2332 | * otherwise we cannot reprogram things. | |
2333 | * | |
2334 | * If its not running, we don't care, ctx->lock will | |
2335 | * serialize against it becoming runnable. | |
39a43640 | 2336 | */ |
63cae12b PZ |
2337 | if (task_curr(ctx->task) && !reprogram) { |
2338 | ret = -ESRCH; | |
2339 | goto unlock; | |
2340 | } | |
a096309b | 2341 | |
63cae12b | 2342 | WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx); |
63b6da39 PZ |
2343 | } else if (task_ctx) { |
2344 | raw_spin_lock(&task_ctx->lock); | |
2c29ef0f | 2345 | } |
b58f6b0d | 2346 | |
63cae12b | 2347 | if (reprogram) { |
a096309b PZ |
2348 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
2349 | add_event_to_ctx(event, ctx); | |
487f05e1 | 2350 | ctx_resched(cpuctx, task_ctx, get_event_type(event)); |
a096309b PZ |
2351 | } else { |
2352 | add_event_to_ctx(event, ctx); | |
2353 | } | |
2354 | ||
63b6da39 | 2355 | unlock: |
2c29ef0f | 2356 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa | 2357 | |
a096309b | 2358 | return ret; |
0793a61d TG |
2359 | } |
2360 | ||
2361 | /* | |
a096309b PZ |
2362 | * Attach a performance event to a context. |
2363 | * | |
2364 | * Very similar to event_function_call, see comment there. | |
0793a61d TG |
2365 | */ |
2366 | static void | |
cdd6c482 IM |
2367 | perf_install_in_context(struct perf_event_context *ctx, |
2368 | struct perf_event *event, | |
0793a61d TG |
2369 | int cpu) |
2370 | { | |
a096309b | 2371 | struct task_struct *task = READ_ONCE(ctx->task); |
39a43640 | 2372 | |
fe4b04fa PZ |
2373 | lockdep_assert_held(&ctx->mutex); |
2374 | ||
0cda4c02 YZ |
2375 | if (event->cpu != -1) |
2376 | event->cpu = cpu; | |
c3f00c70 | 2377 | |
0b8f1e2e PZ |
2378 | /* |
2379 | * Ensures that if we can observe event->ctx, both the event and ctx | |
2380 | * will be 'complete'. See perf_iterate_sb_cpu(). | |
2381 | */ | |
2382 | smp_store_release(&event->ctx, ctx); | |
2383 | ||
a096309b PZ |
2384 | if (!task) { |
2385 | cpu_function_call(cpu, __perf_install_in_context, event); | |
2386 | return; | |
2387 | } | |
2388 | ||
2389 | /* | |
2390 | * Should not happen, we validate the ctx is still alive before calling. | |
2391 | */ | |
2392 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) | |
2393 | return; | |
2394 | ||
39a43640 PZ |
2395 | /* |
2396 | * Installing events is tricky because we cannot rely on ctx->is_active | |
2397 | * to be set in case this is the nr_events 0 -> 1 transition. | |
63cae12b PZ |
2398 | * |
2399 | * Instead we use task_curr(), which tells us if the task is running. | |
2400 | * However, since we use task_curr() outside of rq::lock, we can race | |
2401 | * against the actual state. This means the result can be wrong. | |
2402 | * | |
2403 | * If we get a false positive, we retry, this is harmless. | |
2404 | * | |
2405 | * If we get a false negative, things are complicated. If we are after | |
2406 | * perf_event_context_sched_in() ctx::lock will serialize us, and the | |
2407 | * value must be correct. If we're before, it doesn't matter since | |
2408 | * perf_event_context_sched_in() will program the counter. | |
2409 | * | |
2410 | * However, this hinges on the remote context switch having observed | |
2411 | * our task->perf_event_ctxp[] store, such that it will in fact take | |
2412 | * ctx::lock in perf_event_context_sched_in(). | |
2413 | * | |
2414 | * We do this by task_function_call(), if the IPI fails to hit the task | |
2415 | * we know any future context switch of task must see the | |
2416 | * perf_event_ctpx[] store. | |
39a43640 | 2417 | */ |
63cae12b | 2418 | |
63b6da39 | 2419 | /* |
63cae12b PZ |
2420 | * This smp_mb() orders the task->perf_event_ctxp[] store with the |
2421 | * task_cpu() load, such that if the IPI then does not find the task | |
2422 | * running, a future context switch of that task must observe the | |
2423 | * store. | |
63b6da39 | 2424 | */ |
63cae12b PZ |
2425 | smp_mb(); |
2426 | again: | |
2427 | if (!task_function_call(task, __perf_install_in_context, event)) | |
a096309b PZ |
2428 | return; |
2429 | ||
2430 | raw_spin_lock_irq(&ctx->lock); | |
2431 | task = ctx->task; | |
84c4e620 | 2432 | if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { |
a096309b PZ |
2433 | /* |
2434 | * Cannot happen because we already checked above (which also | |
2435 | * cannot happen), and we hold ctx->mutex, which serializes us | |
2436 | * against perf_event_exit_task_context(). | |
2437 | */ | |
63b6da39 PZ |
2438 | raw_spin_unlock_irq(&ctx->lock); |
2439 | return; | |
2440 | } | |
39a43640 | 2441 | /* |
63cae12b PZ |
2442 | * If the task is not running, ctx->lock will avoid it becoming so, |
2443 | * thus we can safely install the event. | |
39a43640 | 2444 | */ |
63cae12b PZ |
2445 | if (task_curr(task)) { |
2446 | raw_spin_unlock_irq(&ctx->lock); | |
2447 | goto again; | |
2448 | } | |
2449 | add_event_to_ctx(event, ctx); | |
2450 | raw_spin_unlock_irq(&ctx->lock); | |
0793a61d TG |
2451 | } |
2452 | ||
fa289bec | 2453 | /* |
cdd6c482 | 2454 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2455 | * Enabling the leader of a group effectively enables all |
2456 | * the group members that aren't explicitly disabled, so we | |
2457 | * have to update their ->tstamp_enabled also. | |
2458 | * Note: this works for group members as well as group leaders | |
2459 | * since the non-leader members' sibling_lists will be empty. | |
2460 | */ | |
1d9b482e | 2461 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2462 | { |
cdd6c482 | 2463 | struct perf_event *sub; |
4158755d | 2464 | u64 tstamp = perf_event_time(event); |
fa289bec | 2465 | |
cdd6c482 | 2466 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2467 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2468 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2469 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2470 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2471 | } |
fa289bec PM |
2472 | } |
2473 | ||
d859e29f | 2474 | /* |
cdd6c482 | 2475 | * Cross CPU call to enable a performance event |
d859e29f | 2476 | */ |
fae3fde6 PZ |
2477 | static void __perf_event_enable(struct perf_event *event, |
2478 | struct perf_cpu_context *cpuctx, | |
2479 | struct perf_event_context *ctx, | |
2480 | void *info) | |
04289bb9 | 2481 | { |
cdd6c482 | 2482 | struct perf_event *leader = event->group_leader; |
fae3fde6 | 2483 | struct perf_event_context *task_ctx; |
04289bb9 | 2484 | |
6e801e01 PZ |
2485 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2486 | event->state <= PERF_EVENT_STATE_ERROR) | |
fae3fde6 | 2487 | return; |
3cbed429 | 2488 | |
bd2afa49 PZ |
2489 | if (ctx->is_active) |
2490 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); | |
2491 | ||
1d9b482e | 2492 | __perf_event_mark_enabled(event); |
04289bb9 | 2493 | |
fae3fde6 PZ |
2494 | if (!ctx->is_active) |
2495 | return; | |
2496 | ||
e5d1367f | 2497 | if (!event_filter_match(event)) { |
bd2afa49 | 2498 | if (is_cgroup_event(event)) |
e5d1367f | 2499 | perf_cgroup_defer_enabled(event); |
bd2afa49 | 2500 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); |
fae3fde6 | 2501 | return; |
e5d1367f | 2502 | } |
f4c4176f | 2503 | |
04289bb9 | 2504 | /* |
cdd6c482 | 2505 | * If the event is in a group and isn't the group leader, |
d859e29f | 2506 | * then don't put it on unless the group is on. |
04289bb9 | 2507 | */ |
bd2afa49 PZ |
2508 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) { |
2509 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
fae3fde6 | 2510 | return; |
bd2afa49 | 2511 | } |
fe4b04fa | 2512 | |
fae3fde6 PZ |
2513 | task_ctx = cpuctx->task_ctx; |
2514 | if (ctx->task) | |
2515 | WARN_ON_ONCE(task_ctx != ctx); | |
d859e29f | 2516 | |
487f05e1 | 2517 | ctx_resched(cpuctx, task_ctx, get_event_type(event)); |
7b648018 PZ |
2518 | } |
2519 | ||
d859e29f | 2520 | /* |
cdd6c482 | 2521 | * Enable a event. |
c93f7669 | 2522 | * |
cdd6c482 IM |
2523 | * If event->ctx is a cloned context, callers must make sure that |
2524 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2525 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2526 | * perf_event_for_each_child or perf_event_for_each as described |
2527 | * for perf_event_disable. | |
d859e29f | 2528 | */ |
f63a8daa | 2529 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2530 | { |
cdd6c482 | 2531 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2532 | |
7b648018 | 2533 | raw_spin_lock_irq(&ctx->lock); |
6e801e01 PZ |
2534 | if (event->state >= PERF_EVENT_STATE_INACTIVE || |
2535 | event->state < PERF_EVENT_STATE_ERROR) { | |
7b648018 | 2536 | raw_spin_unlock_irq(&ctx->lock); |
d859e29f PM |
2537 | return; |
2538 | } | |
2539 | ||
d859e29f | 2540 | /* |
cdd6c482 | 2541 | * If the event is in error state, clear that first. |
7b648018 PZ |
2542 | * |
2543 | * That way, if we see the event in error state below, we know that it | |
2544 | * has gone back into error state, as distinct from the task having | |
2545 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2546 | */ |
cdd6c482 IM |
2547 | if (event->state == PERF_EVENT_STATE_ERROR) |
2548 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2549 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2550 | |
fae3fde6 | 2551 | event_function_call(event, __perf_event_enable, NULL); |
d859e29f | 2552 | } |
f63a8daa PZ |
2553 | |
2554 | /* | |
2555 | * See perf_event_disable(); | |
2556 | */ | |
2557 | void perf_event_enable(struct perf_event *event) | |
2558 | { | |
2559 | struct perf_event_context *ctx; | |
2560 | ||
2561 | ctx = perf_event_ctx_lock(event); | |
2562 | _perf_event_enable(event); | |
2563 | perf_event_ctx_unlock(event, ctx); | |
2564 | } | |
dcfce4a0 | 2565 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2566 | |
375637bc AS |
2567 | struct stop_event_data { |
2568 | struct perf_event *event; | |
2569 | unsigned int restart; | |
2570 | }; | |
2571 | ||
95ff4ca2 AS |
2572 | static int __perf_event_stop(void *info) |
2573 | { | |
375637bc AS |
2574 | struct stop_event_data *sd = info; |
2575 | struct perf_event *event = sd->event; | |
95ff4ca2 | 2576 | |
375637bc | 2577 | /* if it's already INACTIVE, do nothing */ |
95ff4ca2 AS |
2578 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) |
2579 | return 0; | |
2580 | ||
2581 | /* matches smp_wmb() in event_sched_in() */ | |
2582 | smp_rmb(); | |
2583 | ||
2584 | /* | |
2585 | * There is a window with interrupts enabled before we get here, | |
2586 | * so we need to check again lest we try to stop another CPU's event. | |
2587 | */ | |
2588 | if (READ_ONCE(event->oncpu) != smp_processor_id()) | |
2589 | return -EAGAIN; | |
2590 | ||
2591 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2592 | ||
375637bc AS |
2593 | /* |
2594 | * May race with the actual stop (through perf_pmu_output_stop()), | |
2595 | * but it is only used for events with AUX ring buffer, and such | |
2596 | * events will refuse to restart because of rb::aux_mmap_count==0, | |
2597 | * see comments in perf_aux_output_begin(). | |
2598 | * | |
2599 | * Since this is happening on a event-local CPU, no trace is lost | |
2600 | * while restarting. | |
2601 | */ | |
2602 | if (sd->restart) | |
c9bbdd48 | 2603 | event->pmu->start(event, 0); |
375637bc | 2604 | |
95ff4ca2 AS |
2605 | return 0; |
2606 | } | |
2607 | ||
767ae086 | 2608 | static int perf_event_stop(struct perf_event *event, int restart) |
375637bc AS |
2609 | { |
2610 | struct stop_event_data sd = { | |
2611 | .event = event, | |
767ae086 | 2612 | .restart = restart, |
375637bc AS |
2613 | }; |
2614 | int ret = 0; | |
2615 | ||
2616 | do { | |
2617 | if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) | |
2618 | return 0; | |
2619 | ||
2620 | /* matches smp_wmb() in event_sched_in() */ | |
2621 | smp_rmb(); | |
2622 | ||
2623 | /* | |
2624 | * We only want to restart ACTIVE events, so if the event goes | |
2625 | * inactive here (event->oncpu==-1), there's nothing more to do; | |
2626 | * fall through with ret==-ENXIO. | |
2627 | */ | |
2628 | ret = cpu_function_call(READ_ONCE(event->oncpu), | |
2629 | __perf_event_stop, &sd); | |
2630 | } while (ret == -EAGAIN); | |
2631 | ||
2632 | return ret; | |
2633 | } | |
2634 | ||
2635 | /* | |
2636 | * In order to contain the amount of racy and tricky in the address filter | |
2637 | * configuration management, it is a two part process: | |
2638 | * | |
2639 | * (p1) when userspace mappings change as a result of (1) or (2) or (3) below, | |
2640 | * we update the addresses of corresponding vmas in | |
2641 | * event::addr_filters_offs array and bump the event::addr_filters_gen; | |
2642 | * (p2) when an event is scheduled in (pmu::add), it calls | |
2643 | * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync() | |
2644 | * if the generation has changed since the previous call. | |
2645 | * | |
2646 | * If (p1) happens while the event is active, we restart it to force (p2). | |
2647 | * | |
2648 | * (1) perf_addr_filters_apply(): adjusting filters' offsets based on | |
2649 | * pre-existing mappings, called once when new filters arrive via SET_FILTER | |
2650 | * ioctl; | |
2651 | * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly | |
2652 | * registered mapping, called for every new mmap(), with mm::mmap_sem down | |
2653 | * for reading; | |
2654 | * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process | |
2655 | * of exec. | |
2656 | */ | |
2657 | void perf_event_addr_filters_sync(struct perf_event *event) | |
2658 | { | |
2659 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
2660 | ||
2661 | if (!has_addr_filter(event)) | |
2662 | return; | |
2663 | ||
2664 | raw_spin_lock(&ifh->lock); | |
2665 | if (event->addr_filters_gen != event->hw.addr_filters_gen) { | |
2666 | event->pmu->addr_filters_sync(event); | |
2667 | event->hw.addr_filters_gen = event->addr_filters_gen; | |
2668 | } | |
2669 | raw_spin_unlock(&ifh->lock); | |
2670 | } | |
2671 | EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync); | |
2672 | ||
f63a8daa | 2673 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2674 | { |
2023b359 | 2675 | /* |
cdd6c482 | 2676 | * not supported on inherited events |
2023b359 | 2677 | */ |
2e939d1d | 2678 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2679 | return -EINVAL; |
2680 | ||
cdd6c482 | 2681 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2682 | _perf_event_enable(event); |
2023b359 PZ |
2683 | |
2684 | return 0; | |
79f14641 | 2685 | } |
f63a8daa PZ |
2686 | |
2687 | /* | |
2688 | * See perf_event_disable() | |
2689 | */ | |
2690 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2691 | { | |
2692 | struct perf_event_context *ctx; | |
2693 | int ret; | |
2694 | ||
2695 | ctx = perf_event_ctx_lock(event); | |
2696 | ret = _perf_event_refresh(event, refresh); | |
2697 | perf_event_ctx_unlock(event, ctx); | |
2698 | ||
2699 | return ret; | |
2700 | } | |
26ca5c11 | 2701 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2702 | |
5b0311e1 FW |
2703 | static void ctx_sched_out(struct perf_event_context *ctx, |
2704 | struct perf_cpu_context *cpuctx, | |
2705 | enum event_type_t event_type) | |
235c7fc7 | 2706 | { |
db24d33e | 2707 | int is_active = ctx->is_active; |
c994d613 | 2708 | struct perf_event *event; |
235c7fc7 | 2709 | |
c994d613 | 2710 | lockdep_assert_held(&ctx->lock); |
235c7fc7 | 2711 | |
39a43640 PZ |
2712 | if (likely(!ctx->nr_events)) { |
2713 | /* | |
2714 | * See __perf_remove_from_context(). | |
2715 | */ | |
2716 | WARN_ON_ONCE(ctx->is_active); | |
2717 | if (ctx->task) | |
2718 | WARN_ON_ONCE(cpuctx->task_ctx); | |
facc4307 | 2719 | return; |
39a43640 PZ |
2720 | } |
2721 | ||
db24d33e | 2722 | ctx->is_active &= ~event_type; |
3cbaa590 PZ |
2723 | if (!(ctx->is_active & EVENT_ALL)) |
2724 | ctx->is_active = 0; | |
2725 | ||
63e30d3e PZ |
2726 | if (ctx->task) { |
2727 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2728 | if (!ctx->is_active) | |
2729 | cpuctx->task_ctx = NULL; | |
2730 | } | |
facc4307 | 2731 | |
8fdc6539 PZ |
2732 | /* |
2733 | * Always update time if it was set; not only when it changes. | |
2734 | * Otherwise we can 'forget' to update time for any but the last | |
2735 | * context we sched out. For example: | |
2736 | * | |
2737 | * ctx_sched_out(.event_type = EVENT_FLEXIBLE) | |
2738 | * ctx_sched_out(.event_type = EVENT_PINNED) | |
2739 | * | |
2740 | * would only update time for the pinned events. | |
2741 | */ | |
3cbaa590 PZ |
2742 | if (is_active & EVENT_TIME) { |
2743 | /* update (and stop) ctx time */ | |
2744 | update_context_time(ctx); | |
2745 | update_cgrp_time_from_cpuctx(cpuctx); | |
2746 | } | |
2747 | ||
8fdc6539 PZ |
2748 | is_active ^= ctx->is_active; /* changed bits */ |
2749 | ||
3cbaa590 | 2750 | if (!ctx->nr_active || !(is_active & EVENT_ALL)) |
facc4307 | 2751 | return; |
5b0311e1 | 2752 | |
075e0b00 | 2753 | perf_pmu_disable(ctx->pmu); |
3cbaa590 | 2754 | if (is_active & EVENT_PINNED) { |
889ff015 FW |
2755 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2756 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2757 | } |
889ff015 | 2758 | |
3cbaa590 | 2759 | if (is_active & EVENT_FLEXIBLE) { |
889ff015 | 2760 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2761 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2762 | } |
1b9a644f | 2763 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2764 | } |
2765 | ||
564c2b21 | 2766 | /* |
5a3126d4 PZ |
2767 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2768 | * cloned from the same version of the same context. | |
2769 | * | |
2770 | * Equivalence is measured using a generation number in the context that is | |
2771 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2772 | * and list_del_event(). | |
564c2b21 | 2773 | */ |
cdd6c482 IM |
2774 | static int context_equiv(struct perf_event_context *ctx1, |
2775 | struct perf_event_context *ctx2) | |
564c2b21 | 2776 | { |
211de6eb PZ |
2777 | lockdep_assert_held(&ctx1->lock); |
2778 | lockdep_assert_held(&ctx2->lock); | |
2779 | ||
5a3126d4 PZ |
2780 | /* Pinning disables the swap optimization */ |
2781 | if (ctx1->pin_count || ctx2->pin_count) | |
2782 | return 0; | |
2783 | ||
2784 | /* If ctx1 is the parent of ctx2 */ | |
2785 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2786 | return 1; | |
2787 | ||
2788 | /* If ctx2 is the parent of ctx1 */ | |
2789 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2790 | return 1; | |
2791 | ||
2792 | /* | |
2793 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2794 | * hierarchy, see perf_event_init_context(). | |
2795 | */ | |
2796 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2797 | ctx1->parent_gen == ctx2->parent_gen) | |
2798 | return 1; | |
2799 | ||
2800 | /* Unmatched */ | |
2801 | return 0; | |
564c2b21 PM |
2802 | } |
2803 | ||
cdd6c482 IM |
2804 | static void __perf_event_sync_stat(struct perf_event *event, |
2805 | struct perf_event *next_event) | |
bfbd3381 PZ |
2806 | { |
2807 | u64 value; | |
2808 | ||
cdd6c482 | 2809 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2810 | return; |
2811 | ||
2812 | /* | |
cdd6c482 | 2813 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2814 | * because we're in the middle of a context switch and have IRQs |
2815 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2816 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2817 | * don't need to use it. |
2818 | */ | |
cdd6c482 IM |
2819 | switch (event->state) { |
2820 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2821 | event->pmu->read(event); |
2822 | /* fall-through */ | |
bfbd3381 | 2823 | |
cdd6c482 IM |
2824 | case PERF_EVENT_STATE_INACTIVE: |
2825 | update_event_times(event); | |
bfbd3381 PZ |
2826 | break; |
2827 | ||
2828 | default: | |
2829 | break; | |
2830 | } | |
2831 | ||
2832 | /* | |
cdd6c482 | 2833 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2834 | * values when we flip the contexts. |
2835 | */ | |
e7850595 PZ |
2836 | value = local64_read(&next_event->count); |
2837 | value = local64_xchg(&event->count, value); | |
2838 | local64_set(&next_event->count, value); | |
bfbd3381 | 2839 | |
cdd6c482 IM |
2840 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2841 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2842 | |
bfbd3381 | 2843 | /* |
19d2e755 | 2844 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2845 | */ |
cdd6c482 IM |
2846 | perf_event_update_userpage(event); |
2847 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2848 | } |
2849 | ||
cdd6c482 IM |
2850 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2851 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2852 | { |
cdd6c482 | 2853 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2854 | |
2855 | if (!ctx->nr_stat) | |
2856 | return; | |
2857 | ||
02ffdbc8 PZ |
2858 | update_context_time(ctx); |
2859 | ||
cdd6c482 IM |
2860 | event = list_first_entry(&ctx->event_list, |
2861 | struct perf_event, event_entry); | |
bfbd3381 | 2862 | |
cdd6c482 IM |
2863 | next_event = list_first_entry(&next_ctx->event_list, |
2864 | struct perf_event, event_entry); | |
bfbd3381 | 2865 | |
cdd6c482 IM |
2866 | while (&event->event_entry != &ctx->event_list && |
2867 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2868 | |
cdd6c482 | 2869 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2870 | |
cdd6c482 IM |
2871 | event = list_next_entry(event, event_entry); |
2872 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2873 | } |
2874 | } | |
2875 | ||
fe4b04fa PZ |
2876 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2877 | struct task_struct *next) | |
0793a61d | 2878 | { |
8dc85d54 | 2879 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2880 | struct perf_event_context *next_ctx; |
5a3126d4 | 2881 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2882 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2883 | int do_switch = 1; |
0793a61d | 2884 | |
108b02cf PZ |
2885 | if (likely(!ctx)) |
2886 | return; | |
10989fb2 | 2887 | |
108b02cf PZ |
2888 | cpuctx = __get_cpu_context(ctx); |
2889 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2890 | return; |
2891 | ||
c93f7669 | 2892 | rcu_read_lock(); |
8dc85d54 | 2893 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2894 | if (!next_ctx) |
2895 | goto unlock; | |
2896 | ||
2897 | parent = rcu_dereference(ctx->parent_ctx); | |
2898 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2899 | ||
2900 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2901 | if (!parent && !next_parent) |
5a3126d4 PZ |
2902 | goto unlock; |
2903 | ||
2904 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2905 | /* |
2906 | * Looks like the two contexts are clones, so we might be | |
2907 | * able to optimize the context switch. We lock both | |
2908 | * contexts and check that they are clones under the | |
2909 | * lock (including re-checking that neither has been | |
2910 | * uncloned in the meantime). It doesn't matter which | |
2911 | * order we take the locks because no other cpu could | |
2912 | * be trying to lock both of these tasks. | |
2913 | */ | |
e625cce1 TG |
2914 | raw_spin_lock(&ctx->lock); |
2915 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2916 | if (context_equiv(ctx, next_ctx)) { |
63b6da39 PZ |
2917 | WRITE_ONCE(ctx->task, next); |
2918 | WRITE_ONCE(next_ctx->task, task); | |
5a158c3c YZ |
2919 | |
2920 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2921 | ||
63b6da39 PZ |
2922 | /* |
2923 | * RCU_INIT_POINTER here is safe because we've not | |
2924 | * modified the ctx and the above modification of | |
2925 | * ctx->task and ctx->task_ctx_data are immaterial | |
2926 | * since those values are always verified under | |
2927 | * ctx->lock which we're now holding. | |
2928 | */ | |
2929 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx); | |
2930 | RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx); | |
2931 | ||
c93f7669 | 2932 | do_switch = 0; |
bfbd3381 | 2933 | |
cdd6c482 | 2934 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2935 | } |
e625cce1 TG |
2936 | raw_spin_unlock(&next_ctx->lock); |
2937 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2938 | } |
5a3126d4 | 2939 | unlock: |
c93f7669 | 2940 | rcu_read_unlock(); |
564c2b21 | 2941 | |
c93f7669 | 2942 | if (do_switch) { |
facc4307 | 2943 | raw_spin_lock(&ctx->lock); |
487f05e1 | 2944 | task_ctx_sched_out(cpuctx, ctx, EVENT_ALL); |
facc4307 | 2945 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2946 | } |
0793a61d TG |
2947 | } |
2948 | ||
e48c1788 PZ |
2949 | static DEFINE_PER_CPU(struct list_head, sched_cb_list); |
2950 | ||
ba532500 YZ |
2951 | void perf_sched_cb_dec(struct pmu *pmu) |
2952 | { | |
e48c1788 PZ |
2953 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
2954 | ||
ba532500 | 2955 | this_cpu_dec(perf_sched_cb_usages); |
e48c1788 PZ |
2956 | |
2957 | if (!--cpuctx->sched_cb_usage) | |
2958 | list_del(&cpuctx->sched_cb_entry); | |
ba532500 YZ |
2959 | } |
2960 | ||
e48c1788 | 2961 | |
ba532500 YZ |
2962 | void perf_sched_cb_inc(struct pmu *pmu) |
2963 | { | |
e48c1788 PZ |
2964 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
2965 | ||
2966 | if (!cpuctx->sched_cb_usage++) | |
2967 | list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list)); | |
2968 | ||
ba532500 YZ |
2969 | this_cpu_inc(perf_sched_cb_usages); |
2970 | } | |
2971 | ||
2972 | /* | |
2973 | * This function provides the context switch callback to the lower code | |
2974 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
09e61b4f PZ |
2975 | * |
2976 | * This callback is relevant even to per-cpu events; for example multi event | |
2977 | * PEBS requires this to provide PID/TID information. This requires we flush | |
2978 | * all queued PEBS records before we context switch to a new task. | |
ba532500 YZ |
2979 | */ |
2980 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2981 | struct task_struct *next, | |
2982 | bool sched_in) | |
2983 | { | |
2984 | struct perf_cpu_context *cpuctx; | |
2985 | struct pmu *pmu; | |
ba532500 YZ |
2986 | |
2987 | if (prev == next) | |
2988 | return; | |
2989 | ||
e48c1788 | 2990 | list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) { |
1fd7e416 | 2991 | pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */ |
ba532500 | 2992 | |
e48c1788 PZ |
2993 | if (WARN_ON_ONCE(!pmu->sched_task)) |
2994 | continue; | |
ba532500 | 2995 | |
e48c1788 PZ |
2996 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
2997 | perf_pmu_disable(pmu); | |
ba532500 | 2998 | |
e48c1788 | 2999 | pmu->sched_task(cpuctx->task_ctx, sched_in); |
ba532500 | 3000 | |
e48c1788 PZ |
3001 | perf_pmu_enable(pmu); |
3002 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
ba532500 | 3003 | } |
ba532500 YZ |
3004 | } |
3005 | ||
45ac1403 AH |
3006 | static void perf_event_switch(struct task_struct *task, |
3007 | struct task_struct *next_prev, bool sched_in); | |
3008 | ||
8dc85d54 PZ |
3009 | #define for_each_task_context_nr(ctxn) \ |
3010 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
3011 | ||
3012 | /* | |
3013 | * Called from scheduler to remove the events of the current task, | |
3014 | * with interrupts disabled. | |
3015 | * | |
3016 | * We stop each event and update the event value in event->count. | |
3017 | * | |
3018 | * This does not protect us against NMI, but disable() | |
3019 | * sets the disabled bit in the control field of event _before_ | |
3020 | * accessing the event control register. If a NMI hits, then it will | |
3021 | * not restart the event. | |
3022 | */ | |
ab0cce56 JO |
3023 | void __perf_event_task_sched_out(struct task_struct *task, |
3024 | struct task_struct *next) | |
8dc85d54 PZ |
3025 | { |
3026 | int ctxn; | |
3027 | ||
ba532500 YZ |
3028 | if (__this_cpu_read(perf_sched_cb_usages)) |
3029 | perf_pmu_sched_task(task, next, false); | |
3030 | ||
45ac1403 AH |
3031 | if (atomic_read(&nr_switch_events)) |
3032 | perf_event_switch(task, next, false); | |
3033 | ||
8dc85d54 PZ |
3034 | for_each_task_context_nr(ctxn) |
3035 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
3036 | |
3037 | /* | |
3038 | * if cgroup events exist on this CPU, then we need | |
3039 | * to check if we have to switch out PMU state. | |
3040 | * cgroup event are system-wide mode only | |
3041 | */ | |
4a32fea9 | 3042 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 3043 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
3044 | } |
3045 | ||
5b0311e1 FW |
3046 | /* |
3047 | * Called with IRQs disabled | |
3048 | */ | |
3049 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
3050 | enum event_type_t event_type) | |
3051 | { | |
3052 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
3053 | } |
3054 | ||
235c7fc7 | 3055 | static void |
5b0311e1 | 3056 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 3057 | struct perf_cpu_context *cpuctx) |
0793a61d | 3058 | { |
cdd6c482 | 3059 | struct perf_event *event; |
0793a61d | 3060 | |
889ff015 FW |
3061 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
3062 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 3063 | continue; |
5632ab12 | 3064 | if (!event_filter_match(event)) |
3b6f9e5c PM |
3065 | continue; |
3066 | ||
e5d1367f SE |
3067 | /* may need to reset tstamp_enabled */ |
3068 | if (is_cgroup_event(event)) | |
3069 | perf_cgroup_mark_enabled(event, ctx); | |
3070 | ||
8c9ed8e1 | 3071 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 3072 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
3073 | |
3074 | /* | |
3075 | * If this pinned group hasn't been scheduled, | |
3076 | * put it in error state. | |
3077 | */ | |
cdd6c482 IM |
3078 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
3079 | update_group_times(event); | |
3080 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 3081 | } |
3b6f9e5c | 3082 | } |
5b0311e1 FW |
3083 | } |
3084 | ||
3085 | static void | |
3086 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 3087 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
3088 | { |
3089 | struct perf_event *event; | |
3090 | int can_add_hw = 1; | |
3b6f9e5c | 3091 | |
889ff015 FW |
3092 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
3093 | /* Ignore events in OFF or ERROR state */ | |
3094 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 3095 | continue; |
04289bb9 IM |
3096 | /* |
3097 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 3098 | * of events: |
04289bb9 | 3099 | */ |
5632ab12 | 3100 | if (!event_filter_match(event)) |
0793a61d TG |
3101 | continue; |
3102 | ||
e5d1367f SE |
3103 | /* may need to reset tstamp_enabled */ |
3104 | if (is_cgroup_event(event)) | |
3105 | perf_cgroup_mark_enabled(event, ctx); | |
3106 | ||
9ed6060d | 3107 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 3108 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 3109 | can_add_hw = 0; |
9ed6060d | 3110 | } |
0793a61d | 3111 | } |
5b0311e1 FW |
3112 | } |
3113 | ||
3114 | static void | |
3115 | ctx_sched_in(struct perf_event_context *ctx, | |
3116 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
3117 | enum event_type_t event_type, |
3118 | struct task_struct *task) | |
5b0311e1 | 3119 | { |
db24d33e | 3120 | int is_active = ctx->is_active; |
c994d613 PZ |
3121 | u64 now; |
3122 | ||
3123 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 3124 | |
5b0311e1 | 3125 | if (likely(!ctx->nr_events)) |
facc4307 | 3126 | return; |
5b0311e1 | 3127 | |
3cbaa590 | 3128 | ctx->is_active |= (event_type | EVENT_TIME); |
63e30d3e PZ |
3129 | if (ctx->task) { |
3130 | if (!is_active) | |
3131 | cpuctx->task_ctx = ctx; | |
3132 | else | |
3133 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
3134 | } | |
3135 | ||
3cbaa590 PZ |
3136 | is_active ^= ctx->is_active; /* changed bits */ |
3137 | ||
3138 | if (is_active & EVENT_TIME) { | |
3139 | /* start ctx time */ | |
3140 | now = perf_clock(); | |
3141 | ctx->timestamp = now; | |
3142 | perf_cgroup_set_timestamp(task, ctx); | |
3143 | } | |
3144 | ||
5b0311e1 FW |
3145 | /* |
3146 | * First go through the list and put on any pinned groups | |
3147 | * in order to give them the best chance of going on. | |
3148 | */ | |
3cbaa590 | 3149 | if (is_active & EVENT_PINNED) |
6e37738a | 3150 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
3151 | |
3152 | /* Then walk through the lower prio flexible groups */ | |
3cbaa590 | 3153 | if (is_active & EVENT_FLEXIBLE) |
6e37738a | 3154 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
3155 | } |
3156 | ||
329c0e01 | 3157 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
3158 | enum event_type_t event_type, |
3159 | struct task_struct *task) | |
329c0e01 FW |
3160 | { |
3161 | struct perf_event_context *ctx = &cpuctx->ctx; | |
3162 | ||
e5d1367f | 3163 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
3164 | } |
3165 | ||
e5d1367f SE |
3166 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
3167 | struct task_struct *task) | |
235c7fc7 | 3168 | { |
108b02cf | 3169 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 3170 | |
108b02cf | 3171 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
3172 | if (cpuctx->task_ctx == ctx) |
3173 | return; | |
3174 | ||
facc4307 | 3175 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 3176 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
3177 | /* |
3178 | * We want to keep the following priority order: | |
3179 | * cpu pinned (that don't need to move), task pinned, | |
3180 | * cpu flexible, task flexible. | |
fe45bafb AS |
3181 | * |
3182 | * However, if task's ctx is not carrying any pinned | |
3183 | * events, no need to flip the cpuctx's events around. | |
329c0e01 | 3184 | */ |
fe45bafb AS |
3185 | if (!list_empty(&ctx->pinned_groups)) |
3186 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 3187 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
3188 | perf_pmu_enable(ctx->pmu); |
3189 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
3190 | } |
3191 | ||
8dc85d54 PZ |
3192 | /* |
3193 | * Called from scheduler to add the events of the current task | |
3194 | * with interrupts disabled. | |
3195 | * | |
3196 | * We restore the event value and then enable it. | |
3197 | * | |
3198 | * This does not protect us against NMI, but enable() | |
3199 | * sets the enabled bit in the control field of event _before_ | |
3200 | * accessing the event control register. If a NMI hits, then it will | |
3201 | * keep the event running. | |
3202 | */ | |
ab0cce56 JO |
3203 | void __perf_event_task_sched_in(struct task_struct *prev, |
3204 | struct task_struct *task) | |
8dc85d54 PZ |
3205 | { |
3206 | struct perf_event_context *ctx; | |
3207 | int ctxn; | |
3208 | ||
7e41d177 PZ |
3209 | /* |
3210 | * If cgroup events exist on this CPU, then we need to check if we have | |
3211 | * to switch in PMU state; cgroup event are system-wide mode only. | |
3212 | * | |
3213 | * Since cgroup events are CPU events, we must schedule these in before | |
3214 | * we schedule in the task events. | |
3215 | */ | |
3216 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
3217 | perf_cgroup_sched_in(prev, task); | |
3218 | ||
8dc85d54 PZ |
3219 | for_each_task_context_nr(ctxn) { |
3220 | ctx = task->perf_event_ctxp[ctxn]; | |
3221 | if (likely(!ctx)) | |
3222 | continue; | |
3223 | ||
e5d1367f | 3224 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 3225 | } |
d010b332 | 3226 | |
45ac1403 AH |
3227 | if (atomic_read(&nr_switch_events)) |
3228 | perf_event_switch(task, prev, true); | |
3229 | ||
ba532500 YZ |
3230 | if (__this_cpu_read(perf_sched_cb_usages)) |
3231 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
3232 | } |
3233 | ||
abd50713 PZ |
3234 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
3235 | { | |
3236 | u64 frequency = event->attr.sample_freq; | |
3237 | u64 sec = NSEC_PER_SEC; | |
3238 | u64 divisor, dividend; | |
3239 | ||
3240 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
3241 | ||
3242 | count_fls = fls64(count); | |
3243 | nsec_fls = fls64(nsec); | |
3244 | frequency_fls = fls64(frequency); | |
3245 | sec_fls = 30; | |
3246 | ||
3247 | /* | |
3248 | * We got @count in @nsec, with a target of sample_freq HZ | |
3249 | * the target period becomes: | |
3250 | * | |
3251 | * @count * 10^9 | |
3252 | * period = ------------------- | |
3253 | * @nsec * sample_freq | |
3254 | * | |
3255 | */ | |
3256 | ||
3257 | /* | |
3258 | * Reduce accuracy by one bit such that @a and @b converge | |
3259 | * to a similar magnitude. | |
3260 | */ | |
fe4b04fa | 3261 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
3262 | do { \ |
3263 | if (a##_fls > b##_fls) { \ | |
3264 | a >>= 1; \ | |
3265 | a##_fls--; \ | |
3266 | } else { \ | |
3267 | b >>= 1; \ | |
3268 | b##_fls--; \ | |
3269 | } \ | |
3270 | } while (0) | |
3271 | ||
3272 | /* | |
3273 | * Reduce accuracy until either term fits in a u64, then proceed with | |
3274 | * the other, so that finally we can do a u64/u64 division. | |
3275 | */ | |
3276 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
3277 | REDUCE_FLS(nsec, frequency); | |
3278 | REDUCE_FLS(sec, count); | |
3279 | } | |
3280 | ||
3281 | if (count_fls + sec_fls > 64) { | |
3282 | divisor = nsec * frequency; | |
3283 | ||
3284 | while (count_fls + sec_fls > 64) { | |
3285 | REDUCE_FLS(count, sec); | |
3286 | divisor >>= 1; | |
3287 | } | |
3288 | ||
3289 | dividend = count * sec; | |
3290 | } else { | |
3291 | dividend = count * sec; | |
3292 | ||
3293 | while (nsec_fls + frequency_fls > 64) { | |
3294 | REDUCE_FLS(nsec, frequency); | |
3295 | dividend >>= 1; | |
3296 | } | |
3297 | ||
3298 | divisor = nsec * frequency; | |
3299 | } | |
3300 | ||
f6ab91ad PZ |
3301 | if (!divisor) |
3302 | return dividend; | |
3303 | ||
abd50713 PZ |
3304 | return div64_u64(dividend, divisor); |
3305 | } | |
3306 | ||
e050e3f0 SE |
3307 | static DEFINE_PER_CPU(int, perf_throttled_count); |
3308 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
3309 | ||
f39d47ff | 3310 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 3311 | { |
cdd6c482 | 3312 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 3313 | s64 period, sample_period; |
bd2b5b12 PZ |
3314 | s64 delta; |
3315 | ||
abd50713 | 3316 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
3317 | |
3318 | delta = (s64)(period - hwc->sample_period); | |
3319 | delta = (delta + 7) / 8; /* low pass filter */ | |
3320 | ||
3321 | sample_period = hwc->sample_period + delta; | |
3322 | ||
3323 | if (!sample_period) | |
3324 | sample_period = 1; | |
3325 | ||
bd2b5b12 | 3326 | hwc->sample_period = sample_period; |
abd50713 | 3327 | |
e7850595 | 3328 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
3329 | if (disable) |
3330 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3331 | ||
e7850595 | 3332 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
3333 | |
3334 | if (disable) | |
3335 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 3336 | } |
bd2b5b12 PZ |
3337 | } |
3338 | ||
e050e3f0 SE |
3339 | /* |
3340 | * combine freq adjustment with unthrottling to avoid two passes over the | |
3341 | * events. At the same time, make sure, having freq events does not change | |
3342 | * the rate of unthrottling as that would introduce bias. | |
3343 | */ | |
3344 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
3345 | int needs_unthr) | |
60db5e09 | 3346 | { |
cdd6c482 IM |
3347 | struct perf_event *event; |
3348 | struct hw_perf_event *hwc; | |
e050e3f0 | 3349 | u64 now, period = TICK_NSEC; |
abd50713 | 3350 | s64 delta; |
60db5e09 | 3351 | |
e050e3f0 SE |
3352 | /* |
3353 | * only need to iterate over all events iff: | |
3354 | * - context have events in frequency mode (needs freq adjust) | |
3355 | * - there are events to unthrottle on this cpu | |
3356 | */ | |
3357 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
3358 | return; |
3359 | ||
e050e3f0 | 3360 | raw_spin_lock(&ctx->lock); |
f39d47ff | 3361 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 3362 | |
03541f8b | 3363 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 3364 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
3365 | continue; |
3366 | ||
5632ab12 | 3367 | if (!event_filter_match(event)) |
5d27c23d PZ |
3368 | continue; |
3369 | ||
44377277 AS |
3370 | perf_pmu_disable(event->pmu); |
3371 | ||
cdd6c482 | 3372 | hwc = &event->hw; |
6a24ed6c | 3373 | |
ae23bff1 | 3374 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 3375 | hwc->interrupts = 0; |
cdd6c482 | 3376 | perf_log_throttle(event, 1); |
a4eaf7f1 | 3377 | event->pmu->start(event, 0); |
a78ac325 PZ |
3378 | } |
3379 | ||
cdd6c482 | 3380 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 3381 | goto next; |
60db5e09 | 3382 | |
e050e3f0 SE |
3383 | /* |
3384 | * stop the event and update event->count | |
3385 | */ | |
3386 | event->pmu->stop(event, PERF_EF_UPDATE); | |
3387 | ||
e7850595 | 3388 | now = local64_read(&event->count); |
abd50713 PZ |
3389 | delta = now - hwc->freq_count_stamp; |
3390 | hwc->freq_count_stamp = now; | |
60db5e09 | 3391 | |
e050e3f0 SE |
3392 | /* |
3393 | * restart the event | |
3394 | * reload only if value has changed | |
f39d47ff SE |
3395 | * we have stopped the event so tell that |
3396 | * to perf_adjust_period() to avoid stopping it | |
3397 | * twice. | |
e050e3f0 | 3398 | */ |
abd50713 | 3399 | if (delta > 0) |
f39d47ff | 3400 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3401 | |
3402 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3403 | next: |
3404 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3405 | } |
e050e3f0 | 3406 | |
f39d47ff | 3407 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3408 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3409 | } |
3410 | ||
235c7fc7 | 3411 | /* |
cdd6c482 | 3412 | * Round-robin a context's events: |
235c7fc7 | 3413 | */ |
cdd6c482 | 3414 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3415 | { |
dddd3379 TG |
3416 | /* |
3417 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3418 | * disabled by the inheritance code. | |
3419 | */ | |
3420 | if (!ctx->rotate_disable) | |
3421 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3422 | } |
3423 | ||
9e630205 | 3424 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3425 | { |
8dc85d54 | 3426 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3427 | int rotate = 0; |
7fc23a53 | 3428 | |
b5ab4cd5 | 3429 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3430 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3431 | rotate = 1; | |
3432 | } | |
235c7fc7 | 3433 | |
8dc85d54 | 3434 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3435 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3436 | if (ctx->nr_events != ctx->nr_active) |
3437 | rotate = 1; | |
3438 | } | |
9717e6cd | 3439 | |
e050e3f0 | 3440 | if (!rotate) |
0f5a2601 PZ |
3441 | goto done; |
3442 | ||
facc4307 | 3443 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3444 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3445 | |
e050e3f0 SE |
3446 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3447 | if (ctx) | |
3448 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3449 | |
e050e3f0 SE |
3450 | rotate_ctx(&cpuctx->ctx); |
3451 | if (ctx) | |
3452 | rotate_ctx(ctx); | |
235c7fc7 | 3453 | |
e050e3f0 | 3454 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3455 | |
0f5a2601 PZ |
3456 | perf_pmu_enable(cpuctx->ctx.pmu); |
3457 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3458 | done: |
9e630205 SE |
3459 | |
3460 | return rotate; | |
e9d2b064 PZ |
3461 | } |
3462 | ||
3463 | void perf_event_task_tick(void) | |
3464 | { | |
2fde4f94 MR |
3465 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3466 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3467 | int throttled; |
b5ab4cd5 | 3468 | |
e9d2b064 PZ |
3469 | WARN_ON(!irqs_disabled()); |
3470 | ||
e050e3f0 SE |
3471 | __this_cpu_inc(perf_throttled_seq); |
3472 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
555e0c1e | 3473 | tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
e050e3f0 | 3474 | |
2fde4f94 | 3475 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3476 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3477 | } |
3478 | ||
889ff015 FW |
3479 | static int event_enable_on_exec(struct perf_event *event, |
3480 | struct perf_event_context *ctx) | |
3481 | { | |
3482 | if (!event->attr.enable_on_exec) | |
3483 | return 0; | |
3484 | ||
3485 | event->attr.enable_on_exec = 0; | |
3486 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3487 | return 0; | |
3488 | ||
1d9b482e | 3489 | __perf_event_mark_enabled(event); |
889ff015 FW |
3490 | |
3491 | return 1; | |
3492 | } | |
3493 | ||
57e7986e | 3494 | /* |
cdd6c482 | 3495 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3496 | * This expects task == current. |
3497 | */ | |
c1274499 | 3498 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3499 | { |
c1274499 | 3500 | struct perf_event_context *ctx, *clone_ctx = NULL; |
487f05e1 | 3501 | enum event_type_t event_type = 0; |
3e349507 | 3502 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3503 | struct perf_event *event; |
57e7986e PM |
3504 | unsigned long flags; |
3505 | int enabled = 0; | |
3506 | ||
3507 | local_irq_save(flags); | |
c1274499 | 3508 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3509 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3510 | goto out; |
3511 | ||
3e349507 PZ |
3512 | cpuctx = __get_cpu_context(ctx); |
3513 | perf_ctx_lock(cpuctx, ctx); | |
7fce2509 | 3514 | ctx_sched_out(ctx, cpuctx, EVENT_TIME); |
487f05e1 | 3515 | list_for_each_entry(event, &ctx->event_list, event_entry) { |
3e349507 | 3516 | enabled |= event_enable_on_exec(event, ctx); |
487f05e1 AS |
3517 | event_type |= get_event_type(event); |
3518 | } | |
57e7986e PM |
3519 | |
3520 | /* | |
3e349507 | 3521 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3522 | */ |
3e349507 | 3523 | if (enabled) { |
211de6eb | 3524 | clone_ctx = unclone_ctx(ctx); |
487f05e1 | 3525 | ctx_resched(cpuctx, ctx, event_type); |
7bbba0eb PZ |
3526 | } else { |
3527 | ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); | |
3e349507 PZ |
3528 | } |
3529 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3530 | |
9ed6060d | 3531 | out: |
57e7986e | 3532 | local_irq_restore(flags); |
211de6eb PZ |
3533 | |
3534 | if (clone_ctx) | |
3535 | put_ctx(clone_ctx); | |
57e7986e PM |
3536 | } |
3537 | ||
0492d4c5 PZ |
3538 | struct perf_read_data { |
3539 | struct perf_event *event; | |
3540 | bool group; | |
7d88962e | 3541 | int ret; |
0492d4c5 PZ |
3542 | }; |
3543 | ||
451d24d1 | 3544 | static int __perf_event_read_cpu(struct perf_event *event, int event_cpu) |
d6a2f903 | 3545 | { |
d6a2f903 DCC |
3546 | u16 local_pkg, event_pkg; |
3547 | ||
3548 | if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { | |
451d24d1 PZ |
3549 | int local_cpu = smp_processor_id(); |
3550 | ||
3551 | event_pkg = topology_physical_package_id(event_cpu); | |
3552 | local_pkg = topology_physical_package_id(local_cpu); | |
d6a2f903 DCC |
3553 | |
3554 | if (event_pkg == local_pkg) | |
3555 | return local_cpu; | |
3556 | } | |
3557 | ||
3558 | return event_cpu; | |
3559 | } | |
3560 | ||
0793a61d | 3561 | /* |
cdd6c482 | 3562 | * Cross CPU call to read the hardware event |
0793a61d | 3563 | */ |
cdd6c482 | 3564 | static void __perf_event_read(void *info) |
0793a61d | 3565 | { |
0492d4c5 PZ |
3566 | struct perf_read_data *data = info; |
3567 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3568 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3569 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3570 | struct pmu *pmu = event->pmu; |
621a01ea | 3571 | |
e1ac3614 PM |
3572 | /* |
3573 | * If this is a task context, we need to check whether it is | |
3574 | * the current task context of this cpu. If not it has been | |
3575 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3576 | * event->count would have been updated to a recent sample |
3577 | * when the event was scheduled out. | |
e1ac3614 PM |
3578 | */ |
3579 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3580 | return; | |
3581 | ||
e625cce1 | 3582 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3583 | if (ctx->is_active) { |
542e72fc | 3584 | update_context_time(ctx); |
e5d1367f SE |
3585 | update_cgrp_time_from_event(event); |
3586 | } | |
0492d4c5 | 3587 | |
cdd6c482 | 3588 | update_event_times(event); |
4a00c16e SB |
3589 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3590 | goto unlock; | |
0492d4c5 | 3591 | |
4a00c16e SB |
3592 | if (!data->group) { |
3593 | pmu->read(event); | |
3594 | data->ret = 0; | |
0492d4c5 | 3595 | goto unlock; |
4a00c16e SB |
3596 | } |
3597 | ||
3598 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3599 | ||
3600 | pmu->read(event); | |
0492d4c5 PZ |
3601 | |
3602 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3603 | update_event_times(sub); | |
4a00c16e SB |
3604 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3605 | /* | |
3606 | * Use sibling's PMU rather than @event's since | |
3607 | * sibling could be on different (eg: software) PMU. | |
3608 | */ | |
0492d4c5 | 3609 | sub->pmu->read(sub); |
4a00c16e | 3610 | } |
0492d4c5 | 3611 | } |
4a00c16e SB |
3612 | |
3613 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3614 | |
3615 | unlock: | |
e625cce1 | 3616 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3617 | } |
3618 | ||
b5e58793 PZ |
3619 | static inline u64 perf_event_count(struct perf_event *event) |
3620 | { | |
eacd3ecc MF |
3621 | if (event->pmu->count) |
3622 | return event->pmu->count(event); | |
3623 | ||
3624 | return __perf_event_count(event); | |
b5e58793 PZ |
3625 | } |
3626 | ||
ffe8690c KX |
3627 | /* |
3628 | * NMI-safe method to read a local event, that is an event that | |
3629 | * is: | |
3630 | * - either for the current task, or for this CPU | |
3631 | * - does not have inherit set, for inherited task events | |
3632 | * will not be local and we cannot read them atomically | |
3633 | * - must not have a pmu::count method | |
3634 | */ | |
f91840a3 | 3635 | int perf_event_read_local(struct perf_event *event, u64 *value) |
ffe8690c KX |
3636 | { |
3637 | unsigned long flags; | |
f91840a3 | 3638 | int ret = 0; |
ffe8690c KX |
3639 | |
3640 | /* | |
3641 | * Disabling interrupts avoids all counter scheduling (context | |
3642 | * switches, timer based rotation and IPIs). | |
3643 | */ | |
3644 | local_irq_save(flags); | |
3645 | ||
ffe8690c KX |
3646 | /* |
3647 | * It must not be an event with inherit set, we cannot read | |
3648 | * all child counters from atomic context. | |
3649 | */ | |
f91840a3 AS |
3650 | if (event->attr.inherit) { |
3651 | ret = -EOPNOTSUPP; | |
3652 | goto out; | |
3653 | } | |
ffe8690c KX |
3654 | |
3655 | /* | |
3656 | * It must not have a pmu::count method, those are not | |
3657 | * NMI safe. | |
3658 | */ | |
f91840a3 AS |
3659 | if (event->pmu->count) { |
3660 | ret = -EOPNOTSUPP; | |
3661 | goto out; | |
3662 | } | |
3663 | ||
3664 | /* If this is a per-task event, it must be for current */ | |
3665 | if ((event->attach_state & PERF_ATTACH_TASK) && | |
3666 | event->hw.target != current) { | |
3667 | ret = -EINVAL; | |
3668 | goto out; | |
3669 | } | |
3670 | ||
3671 | /* If this is a per-CPU event, it must be for this CPU */ | |
3672 | if (!(event->attach_state & PERF_ATTACH_TASK) && | |
3673 | event->cpu != smp_processor_id()) { | |
3674 | ret = -EINVAL; | |
3675 | goto out; | |
3676 | } | |
ffe8690c KX |
3677 | |
3678 | /* | |
3679 | * If the event is currently on this CPU, its either a per-task event, | |
3680 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3681 | * oncpu == -1). | |
3682 | */ | |
3683 | if (event->oncpu == smp_processor_id()) | |
3684 | event->pmu->read(event); | |
3685 | ||
f91840a3 AS |
3686 | *value = local64_read(&event->count); |
3687 | out: | |
ffe8690c KX |
3688 | local_irq_restore(flags); |
3689 | ||
f91840a3 | 3690 | return ret; |
ffe8690c KX |
3691 | } |
3692 | ||
7d88962e | 3693 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3694 | { |
451d24d1 | 3695 | int event_cpu, ret = 0; |
7d88962e | 3696 | |
0793a61d | 3697 | /* |
cdd6c482 IM |
3698 | * If event is enabled and currently active on a CPU, update the |
3699 | * value in the event structure: | |
0793a61d | 3700 | */ |
cdd6c482 | 3701 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3702 | struct perf_read_data data = { |
3703 | .event = event, | |
3704 | .group = group, | |
7d88962e | 3705 | .ret = 0, |
0492d4c5 | 3706 | }; |
d6a2f903 | 3707 | |
451d24d1 PZ |
3708 | event_cpu = READ_ONCE(event->oncpu); |
3709 | if ((unsigned)event_cpu >= nr_cpu_ids) | |
3710 | return 0; | |
3711 | ||
3712 | preempt_disable(); | |
3713 | event_cpu = __perf_event_read_cpu(event, event_cpu); | |
d6a2f903 | 3714 | |
58763148 PZ |
3715 | /* |
3716 | * Purposely ignore the smp_call_function_single() return | |
3717 | * value. | |
3718 | * | |
451d24d1 | 3719 | * If event_cpu isn't a valid CPU it means the event got |
58763148 PZ |
3720 | * scheduled out and that will have updated the event count. |
3721 | * | |
3722 | * Therefore, either way, we'll have an up-to-date event count | |
3723 | * after this. | |
3724 | */ | |
451d24d1 PZ |
3725 | (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); |
3726 | preempt_enable(); | |
58763148 | 3727 | ret = data.ret; |
cdd6c482 | 3728 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3729 | struct perf_event_context *ctx = event->ctx; |
3730 | unsigned long flags; | |
3731 | ||
e625cce1 | 3732 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3733 | /* |
3734 | * may read while context is not active | |
3735 | * (e.g., thread is blocked), in that case | |
3736 | * we cannot update context time | |
3737 | */ | |
e5d1367f | 3738 | if (ctx->is_active) { |
c530ccd9 | 3739 | update_context_time(ctx); |
e5d1367f SE |
3740 | update_cgrp_time_from_event(event); |
3741 | } | |
0492d4c5 PZ |
3742 | if (group) |
3743 | update_group_times(event); | |
3744 | else | |
3745 | update_event_times(event); | |
e625cce1 | 3746 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3747 | } |
7d88962e SB |
3748 | |
3749 | return ret; | |
0793a61d TG |
3750 | } |
3751 | ||
a63eaf34 | 3752 | /* |
cdd6c482 | 3753 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3754 | */ |
eb184479 | 3755 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3756 | { |
e625cce1 | 3757 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3758 | mutex_init(&ctx->mutex); |
2fde4f94 | 3759 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3760 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3761 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3762 | INIT_LIST_HEAD(&ctx->event_list); |
3763 | atomic_set(&ctx->refcount, 1); | |
eb184479 PZ |
3764 | } |
3765 | ||
3766 | static struct perf_event_context * | |
3767 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3768 | { | |
3769 | struct perf_event_context *ctx; | |
3770 | ||
3771 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3772 | if (!ctx) | |
3773 | return NULL; | |
3774 | ||
3775 | __perf_event_init_context(ctx); | |
3776 | if (task) { | |
3777 | ctx->task = task; | |
3778 | get_task_struct(task); | |
0793a61d | 3779 | } |
eb184479 PZ |
3780 | ctx->pmu = pmu; |
3781 | ||
3782 | return ctx; | |
a63eaf34 PM |
3783 | } |
3784 | ||
2ebd4ffb MH |
3785 | static struct task_struct * |
3786 | find_lively_task_by_vpid(pid_t vpid) | |
3787 | { | |
3788 | struct task_struct *task; | |
0793a61d TG |
3789 | |
3790 | rcu_read_lock(); | |
2ebd4ffb | 3791 | if (!vpid) |
0793a61d TG |
3792 | task = current; |
3793 | else | |
2ebd4ffb | 3794 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3795 | if (task) |
3796 | get_task_struct(task); | |
3797 | rcu_read_unlock(); | |
3798 | ||
3799 | if (!task) | |
3800 | return ERR_PTR(-ESRCH); | |
3801 | ||
2ebd4ffb | 3802 | return task; |
2ebd4ffb MH |
3803 | } |
3804 | ||
fe4b04fa PZ |
3805 | /* |
3806 | * Returns a matching context with refcount and pincount. | |
3807 | */ | |
108b02cf | 3808 | static struct perf_event_context * |
4af57ef2 YZ |
3809 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3810 | struct perf_event *event) | |
0793a61d | 3811 | { |
211de6eb | 3812 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3813 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3814 | void *task_ctx_data = NULL; |
25346b93 | 3815 | unsigned long flags; |
8dc85d54 | 3816 | int ctxn, err; |
4af57ef2 | 3817 | int cpu = event->cpu; |
0793a61d | 3818 | |
22a4ec72 | 3819 | if (!task) { |
cdd6c482 | 3820 | /* Must be root to operate on a CPU event: */ |
0764771d | 3821 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3822 | return ERR_PTR(-EACCES); |
3823 | ||
108b02cf | 3824 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3825 | ctx = &cpuctx->ctx; |
c93f7669 | 3826 | get_ctx(ctx); |
fe4b04fa | 3827 | ++ctx->pin_count; |
0793a61d | 3828 | |
0793a61d TG |
3829 | return ctx; |
3830 | } | |
3831 | ||
8dc85d54 PZ |
3832 | err = -EINVAL; |
3833 | ctxn = pmu->task_ctx_nr; | |
3834 | if (ctxn < 0) | |
3835 | goto errout; | |
3836 | ||
4af57ef2 YZ |
3837 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3838 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3839 | if (!task_ctx_data) { | |
3840 | err = -ENOMEM; | |
3841 | goto errout; | |
3842 | } | |
3843 | } | |
3844 | ||
9ed6060d | 3845 | retry: |
8dc85d54 | 3846 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3847 | if (ctx) { |
211de6eb | 3848 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3849 | ++ctx->pin_count; |
4af57ef2 YZ |
3850 | |
3851 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3852 | ctx->task_ctx_data = task_ctx_data; | |
3853 | task_ctx_data = NULL; | |
3854 | } | |
e625cce1 | 3855 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3856 | |
3857 | if (clone_ctx) | |
3858 | put_ctx(clone_ctx); | |
9137fb28 | 3859 | } else { |
eb184479 | 3860 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3861 | err = -ENOMEM; |
3862 | if (!ctx) | |
3863 | goto errout; | |
eb184479 | 3864 | |
4af57ef2 YZ |
3865 | if (task_ctx_data) { |
3866 | ctx->task_ctx_data = task_ctx_data; | |
3867 | task_ctx_data = NULL; | |
3868 | } | |
3869 | ||
dbe08d82 ON |
3870 | err = 0; |
3871 | mutex_lock(&task->perf_event_mutex); | |
3872 | /* | |
3873 | * If it has already passed perf_event_exit_task(). | |
3874 | * we must see PF_EXITING, it takes this mutex too. | |
3875 | */ | |
3876 | if (task->flags & PF_EXITING) | |
3877 | err = -ESRCH; | |
3878 | else if (task->perf_event_ctxp[ctxn]) | |
3879 | err = -EAGAIN; | |
fe4b04fa | 3880 | else { |
9137fb28 | 3881 | get_ctx(ctx); |
fe4b04fa | 3882 | ++ctx->pin_count; |
dbe08d82 | 3883 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3884 | } |
dbe08d82 ON |
3885 | mutex_unlock(&task->perf_event_mutex); |
3886 | ||
3887 | if (unlikely(err)) { | |
9137fb28 | 3888 | put_ctx(ctx); |
dbe08d82 ON |
3889 | |
3890 | if (err == -EAGAIN) | |
3891 | goto retry; | |
3892 | goto errout; | |
a63eaf34 PM |
3893 | } |
3894 | } | |
3895 | ||
4af57ef2 | 3896 | kfree(task_ctx_data); |
0793a61d | 3897 | return ctx; |
c93f7669 | 3898 | |
9ed6060d | 3899 | errout: |
4af57ef2 | 3900 | kfree(task_ctx_data); |
c93f7669 | 3901 | return ERR_PTR(err); |
0793a61d TG |
3902 | } |
3903 | ||
6fb2915d | 3904 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3905 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3906 | |
cdd6c482 | 3907 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3908 | { |
cdd6c482 | 3909 | struct perf_event *event; |
592903cd | 3910 | |
cdd6c482 IM |
3911 | event = container_of(head, struct perf_event, rcu_head); |
3912 | if (event->ns) | |
3913 | put_pid_ns(event->ns); | |
6fb2915d | 3914 | perf_event_free_filter(event); |
cdd6c482 | 3915 | kfree(event); |
592903cd PZ |
3916 | } |
3917 | ||
b69cf536 PZ |
3918 | static void ring_buffer_attach(struct perf_event *event, |
3919 | struct ring_buffer *rb); | |
925d519a | 3920 | |
f2fb6bef KL |
3921 | static void detach_sb_event(struct perf_event *event) |
3922 | { | |
3923 | struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu); | |
3924 | ||
3925 | raw_spin_lock(&pel->lock); | |
3926 | list_del_rcu(&event->sb_list); | |
3927 | raw_spin_unlock(&pel->lock); | |
3928 | } | |
3929 | ||
a4f144eb | 3930 | static bool is_sb_event(struct perf_event *event) |
f2fb6bef | 3931 | { |
a4f144eb DCC |
3932 | struct perf_event_attr *attr = &event->attr; |
3933 | ||
f2fb6bef | 3934 | if (event->parent) |
a4f144eb | 3935 | return false; |
f2fb6bef KL |
3936 | |
3937 | if (event->attach_state & PERF_ATTACH_TASK) | |
a4f144eb | 3938 | return false; |
f2fb6bef | 3939 | |
a4f144eb DCC |
3940 | if (attr->mmap || attr->mmap_data || attr->mmap2 || |
3941 | attr->comm || attr->comm_exec || | |
3942 | attr->task || | |
3943 | attr->context_switch) | |
3944 | return true; | |
3945 | return false; | |
3946 | } | |
3947 | ||
3948 | static void unaccount_pmu_sb_event(struct perf_event *event) | |
3949 | { | |
3950 | if (is_sb_event(event)) | |
3951 | detach_sb_event(event); | |
f2fb6bef KL |
3952 | } |
3953 | ||
4beb31f3 | 3954 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3955 | { |
4beb31f3 FW |
3956 | if (event->parent) |
3957 | return; | |
3958 | ||
4beb31f3 FW |
3959 | if (is_cgroup_event(event)) |
3960 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3961 | } | |
925d519a | 3962 | |
555e0c1e FW |
3963 | #ifdef CONFIG_NO_HZ_FULL |
3964 | static DEFINE_SPINLOCK(nr_freq_lock); | |
3965 | #endif | |
3966 | ||
3967 | static void unaccount_freq_event_nohz(void) | |
3968 | { | |
3969 | #ifdef CONFIG_NO_HZ_FULL | |
3970 | spin_lock(&nr_freq_lock); | |
3971 | if (atomic_dec_and_test(&nr_freq_events)) | |
3972 | tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS); | |
3973 | spin_unlock(&nr_freq_lock); | |
3974 | #endif | |
3975 | } | |
3976 | ||
3977 | static void unaccount_freq_event(void) | |
3978 | { | |
3979 | if (tick_nohz_full_enabled()) | |
3980 | unaccount_freq_event_nohz(); | |
3981 | else | |
3982 | atomic_dec(&nr_freq_events); | |
3983 | } | |
3984 | ||
4beb31f3 FW |
3985 | static void unaccount_event(struct perf_event *event) |
3986 | { | |
25432ae9 PZ |
3987 | bool dec = false; |
3988 | ||
4beb31f3 FW |
3989 | if (event->parent) |
3990 | return; | |
3991 | ||
3992 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3993 | dec = true; |
4beb31f3 FW |
3994 | if (event->attr.mmap || event->attr.mmap_data) |
3995 | atomic_dec(&nr_mmap_events); | |
3996 | if (event->attr.comm) | |
3997 | atomic_dec(&nr_comm_events); | |
e4222673 HB |
3998 | if (event->attr.namespaces) |
3999 | atomic_dec(&nr_namespaces_events); | |
4beb31f3 FW |
4000 | if (event->attr.task) |
4001 | atomic_dec(&nr_task_events); | |
948b26b6 | 4002 | if (event->attr.freq) |
555e0c1e | 4003 | unaccount_freq_event(); |
45ac1403 | 4004 | if (event->attr.context_switch) { |
25432ae9 | 4005 | dec = true; |
45ac1403 AH |
4006 | atomic_dec(&nr_switch_events); |
4007 | } | |
4beb31f3 | 4008 | if (is_cgroup_event(event)) |
25432ae9 | 4009 | dec = true; |
4beb31f3 | 4010 | if (has_branch_stack(event)) |
25432ae9 PZ |
4011 | dec = true; |
4012 | ||
9107c89e PZ |
4013 | if (dec) { |
4014 | if (!atomic_add_unless(&perf_sched_count, -1, 1)) | |
4015 | schedule_delayed_work(&perf_sched_work, HZ); | |
4016 | } | |
4beb31f3 FW |
4017 | |
4018 | unaccount_event_cpu(event, event->cpu); | |
f2fb6bef KL |
4019 | |
4020 | unaccount_pmu_sb_event(event); | |
4beb31f3 | 4021 | } |
925d519a | 4022 | |
9107c89e PZ |
4023 | static void perf_sched_delayed(struct work_struct *work) |
4024 | { | |
4025 | mutex_lock(&perf_sched_mutex); | |
4026 | if (atomic_dec_and_test(&perf_sched_count)) | |
4027 | static_branch_disable(&perf_sched_events); | |
4028 | mutex_unlock(&perf_sched_mutex); | |
4029 | } | |
4030 | ||
bed5b25a AS |
4031 | /* |
4032 | * The following implement mutual exclusion of events on "exclusive" pmus | |
4033 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
4034 | * at a time, so we disallow creating events that might conflict, namely: | |
4035 | * | |
4036 | * 1) cpu-wide events in the presence of per-task events, | |
4037 | * 2) per-task events in the presence of cpu-wide events, | |
4038 | * 3) two matching events on the same context. | |
4039 | * | |
4040 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
a0733e69 | 4041 | * _free_event()), the latter -- before the first perf_install_in_context(). |
bed5b25a AS |
4042 | */ |
4043 | static int exclusive_event_init(struct perf_event *event) | |
4044 | { | |
4045 | struct pmu *pmu = event->pmu; | |
4046 | ||
4047 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4048 | return 0; | |
4049 | ||
4050 | /* | |
4051 | * Prevent co-existence of per-task and cpu-wide events on the | |
4052 | * same exclusive pmu. | |
4053 | * | |
4054 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
4055 | * events on this "exclusive" pmu, positive means there are | |
4056 | * per-task events. | |
4057 | * | |
4058 | * Since this is called in perf_event_alloc() path, event::ctx | |
4059 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
4060 | * to mean "per-task event", because unlike other attach states it | |
4061 | * never gets cleared. | |
4062 | */ | |
4063 | if (event->attach_state & PERF_ATTACH_TASK) { | |
4064 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
4065 | return -EBUSY; | |
4066 | } else { | |
4067 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
4068 | return -EBUSY; | |
4069 | } | |
4070 | ||
4071 | return 0; | |
4072 | } | |
4073 | ||
4074 | static void exclusive_event_destroy(struct perf_event *event) | |
4075 | { | |
4076 | struct pmu *pmu = event->pmu; | |
4077 | ||
4078 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4079 | return; | |
4080 | ||
4081 | /* see comment in exclusive_event_init() */ | |
4082 | if (event->attach_state & PERF_ATTACH_TASK) | |
4083 | atomic_dec(&pmu->exclusive_cnt); | |
4084 | else | |
4085 | atomic_inc(&pmu->exclusive_cnt); | |
4086 | } | |
4087 | ||
4088 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
4089 | { | |
3bf6215a | 4090 | if ((e1->pmu == e2->pmu) && |
bed5b25a AS |
4091 | (e1->cpu == e2->cpu || |
4092 | e1->cpu == -1 || | |
4093 | e2->cpu == -1)) | |
4094 | return true; | |
4095 | return false; | |
4096 | } | |
4097 | ||
4098 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
4099 | static bool exclusive_event_installable(struct perf_event *event, | |
4100 | struct perf_event_context *ctx) | |
4101 | { | |
4102 | struct perf_event *iter_event; | |
4103 | struct pmu *pmu = event->pmu; | |
4104 | ||
4105 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
4106 | return true; | |
4107 | ||
4108 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
4109 | if (exclusive_event_match(iter_event, event)) | |
4110 | return false; | |
4111 | } | |
4112 | ||
4113 | return true; | |
4114 | } | |
4115 | ||
375637bc AS |
4116 | static void perf_addr_filters_splice(struct perf_event *event, |
4117 | struct list_head *head); | |
4118 | ||
683ede43 | 4119 | static void _free_event(struct perf_event *event) |
f1600952 | 4120 | { |
e360adbe | 4121 | irq_work_sync(&event->pending); |
925d519a | 4122 | |
4beb31f3 | 4123 | unaccount_event(event); |
9ee318a7 | 4124 | |
76369139 | 4125 | if (event->rb) { |
9bb5d40c PZ |
4126 | /* |
4127 | * Can happen when we close an event with re-directed output. | |
4128 | * | |
4129 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
4130 | * over us; possibly making our ring_buffer_put() the last. | |
4131 | */ | |
4132 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 4133 | ring_buffer_attach(event, NULL); |
9bb5d40c | 4134 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
4135 | } |
4136 | ||
e5d1367f SE |
4137 | if (is_cgroup_event(event)) |
4138 | perf_detach_cgroup(event); | |
4139 | ||
a0733e69 PZ |
4140 | if (!event->parent) { |
4141 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) | |
4142 | put_callchain_buffers(); | |
4143 | } | |
4144 | ||
4145 | perf_event_free_bpf_prog(event); | |
375637bc AS |
4146 | perf_addr_filters_splice(event, NULL); |
4147 | kfree(event->addr_filters_offs); | |
a0733e69 PZ |
4148 | |
4149 | if (event->destroy) | |
4150 | event->destroy(event); | |
4151 | ||
4152 | if (event->ctx) | |
4153 | put_ctx(event->ctx); | |
4154 | ||
62a92c8f AS |
4155 | exclusive_event_destroy(event); |
4156 | module_put(event->pmu->module); | |
a0733e69 PZ |
4157 | |
4158 | call_rcu(&event->rcu_head, free_event_rcu); | |
f1600952 PZ |
4159 | } |
4160 | ||
683ede43 PZ |
4161 | /* |
4162 | * Used to free events which have a known refcount of 1, such as in error paths | |
4163 | * where the event isn't exposed yet and inherited events. | |
4164 | */ | |
4165 | static void free_event(struct perf_event *event) | |
0793a61d | 4166 | { |
683ede43 PZ |
4167 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
4168 | "unexpected event refcount: %ld; ptr=%p\n", | |
4169 | atomic_long_read(&event->refcount), event)) { | |
4170 | /* leak to avoid use-after-free */ | |
4171 | return; | |
4172 | } | |
0793a61d | 4173 | |
683ede43 | 4174 | _free_event(event); |
0793a61d TG |
4175 | } |
4176 | ||
a66a3052 | 4177 | /* |
f8697762 | 4178 | * Remove user event from the owner task. |
a66a3052 | 4179 | */ |
f8697762 | 4180 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 4181 | { |
8882135b | 4182 | struct task_struct *owner; |
fb0459d7 | 4183 | |
8882135b | 4184 | rcu_read_lock(); |
8882135b | 4185 | /* |
f47c02c0 PZ |
4186 | * Matches the smp_store_release() in perf_event_exit_task(). If we |
4187 | * observe !owner it means the list deletion is complete and we can | |
4188 | * indeed free this event, otherwise we need to serialize on | |
8882135b PZ |
4189 | * owner->perf_event_mutex. |
4190 | */ | |
f47c02c0 | 4191 | owner = lockless_dereference(event->owner); |
8882135b PZ |
4192 | if (owner) { |
4193 | /* | |
4194 | * Since delayed_put_task_struct() also drops the last | |
4195 | * task reference we can safely take a new reference | |
4196 | * while holding the rcu_read_lock(). | |
4197 | */ | |
4198 | get_task_struct(owner); | |
4199 | } | |
4200 | rcu_read_unlock(); | |
4201 | ||
4202 | if (owner) { | |
f63a8daa PZ |
4203 | /* |
4204 | * If we're here through perf_event_exit_task() we're already | |
4205 | * holding ctx->mutex which would be an inversion wrt. the | |
4206 | * normal lock order. | |
4207 | * | |
4208 | * However we can safely take this lock because its the child | |
4209 | * ctx->mutex. | |
4210 | */ | |
4211 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
4212 | ||
8882135b PZ |
4213 | /* |
4214 | * We have to re-check the event->owner field, if it is cleared | |
4215 | * we raced with perf_event_exit_task(), acquiring the mutex | |
4216 | * ensured they're done, and we can proceed with freeing the | |
4217 | * event. | |
4218 | */ | |
f47c02c0 | 4219 | if (event->owner) { |
8882135b | 4220 | list_del_init(&event->owner_entry); |
f47c02c0 PZ |
4221 | smp_store_release(&event->owner, NULL); |
4222 | } | |
8882135b PZ |
4223 | mutex_unlock(&owner->perf_event_mutex); |
4224 | put_task_struct(owner); | |
4225 | } | |
f8697762 JO |
4226 | } |
4227 | ||
f8697762 JO |
4228 | static void put_event(struct perf_event *event) |
4229 | { | |
f8697762 JO |
4230 | if (!atomic_long_dec_and_test(&event->refcount)) |
4231 | return; | |
4232 | ||
c6e5b732 PZ |
4233 | _free_event(event); |
4234 | } | |
4235 | ||
4236 | /* | |
4237 | * Kill an event dead; while event:refcount will preserve the event | |
4238 | * object, it will not preserve its functionality. Once the last 'user' | |
4239 | * gives up the object, we'll destroy the thing. | |
4240 | */ | |
4241 | int perf_event_release_kernel(struct perf_event *event) | |
4242 | { | |
a4f4bb6d | 4243 | struct perf_event_context *ctx = event->ctx; |
c6e5b732 PZ |
4244 | struct perf_event *child, *tmp; |
4245 | ||
a4f4bb6d PZ |
4246 | /* |
4247 | * If we got here through err_file: fput(event_file); we will not have | |
4248 | * attached to a context yet. | |
4249 | */ | |
4250 | if (!ctx) { | |
4251 | WARN_ON_ONCE(event->attach_state & | |
4252 | (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); | |
4253 | goto no_ctx; | |
4254 | } | |
4255 | ||
f8697762 JO |
4256 | if (!is_kernel_event(event)) |
4257 | perf_remove_from_owner(event); | |
8882135b | 4258 | |
5fa7c8ec | 4259 | ctx = perf_event_ctx_lock(event); |
a83fe28e | 4260 | WARN_ON_ONCE(ctx->parent_ctx); |
a69b0ca4 | 4261 | perf_remove_from_context(event, DETACH_GROUP); |
683ede43 | 4262 | |
a69b0ca4 | 4263 | raw_spin_lock_irq(&ctx->lock); |
683ede43 | 4264 | /* |
d8a8cfc7 | 4265 | * Mark this event as STATE_DEAD, there is no external reference to it |
a69b0ca4 | 4266 | * anymore. |
683ede43 | 4267 | * |
a69b0ca4 PZ |
4268 | * Anybody acquiring event->child_mutex after the below loop _must_ |
4269 | * also see this, most importantly inherit_event() which will avoid | |
4270 | * placing more children on the list. | |
683ede43 | 4271 | * |
c6e5b732 PZ |
4272 | * Thus this guarantees that we will in fact observe and kill _ALL_ |
4273 | * child events. | |
683ede43 | 4274 | */ |
a69b0ca4 PZ |
4275 | event->state = PERF_EVENT_STATE_DEAD; |
4276 | raw_spin_unlock_irq(&ctx->lock); | |
4277 | ||
4278 | perf_event_ctx_unlock(event, ctx); | |
683ede43 | 4279 | |
c6e5b732 PZ |
4280 | again: |
4281 | mutex_lock(&event->child_mutex); | |
4282 | list_for_each_entry(child, &event->child_list, child_list) { | |
a6fa941d | 4283 | |
c6e5b732 PZ |
4284 | /* |
4285 | * Cannot change, child events are not migrated, see the | |
4286 | * comment with perf_event_ctx_lock_nested(). | |
4287 | */ | |
4288 | ctx = lockless_dereference(child->ctx); | |
4289 | /* | |
4290 | * Since child_mutex nests inside ctx::mutex, we must jump | |
4291 | * through hoops. We start by grabbing a reference on the ctx. | |
4292 | * | |
4293 | * Since the event cannot get freed while we hold the | |
4294 | * child_mutex, the context must also exist and have a !0 | |
4295 | * reference count. | |
4296 | */ | |
4297 | get_ctx(ctx); | |
4298 | ||
4299 | /* | |
4300 | * Now that we have a ctx ref, we can drop child_mutex, and | |
4301 | * acquire ctx::mutex without fear of it going away. Then we | |
4302 | * can re-acquire child_mutex. | |
4303 | */ | |
4304 | mutex_unlock(&event->child_mutex); | |
4305 | mutex_lock(&ctx->mutex); | |
4306 | mutex_lock(&event->child_mutex); | |
4307 | ||
4308 | /* | |
4309 | * Now that we hold ctx::mutex and child_mutex, revalidate our | |
4310 | * state, if child is still the first entry, it didn't get freed | |
4311 | * and we can continue doing so. | |
4312 | */ | |
4313 | tmp = list_first_entry_or_null(&event->child_list, | |
4314 | struct perf_event, child_list); | |
4315 | if (tmp == child) { | |
4316 | perf_remove_from_context(child, DETACH_GROUP); | |
4317 | list_del(&child->child_list); | |
4318 | free_event(child); | |
4319 | /* | |
4320 | * This matches the refcount bump in inherit_event(); | |
4321 | * this can't be the last reference. | |
4322 | */ | |
4323 | put_event(event); | |
4324 | } | |
4325 | ||
4326 | mutex_unlock(&event->child_mutex); | |
4327 | mutex_unlock(&ctx->mutex); | |
4328 | put_ctx(ctx); | |
4329 | goto again; | |
4330 | } | |
4331 | mutex_unlock(&event->child_mutex); | |
4332 | ||
a4f4bb6d PZ |
4333 | no_ctx: |
4334 | put_event(event); /* Must be the 'last' reference */ | |
683ede43 PZ |
4335 | return 0; |
4336 | } | |
4337 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
4338 | ||
8b10c5e2 PZ |
4339 | /* |
4340 | * Called when the last reference to the file is gone. | |
4341 | */ | |
a6fa941d AV |
4342 | static int perf_release(struct inode *inode, struct file *file) |
4343 | { | |
c6e5b732 | 4344 | perf_event_release_kernel(file->private_data); |
a6fa941d | 4345 | return 0; |
fb0459d7 | 4346 | } |
fb0459d7 | 4347 | |
59ed446f | 4348 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 4349 | { |
cdd6c482 | 4350 | struct perf_event *child; |
e53c0994 PZ |
4351 | u64 total = 0; |
4352 | ||
59ed446f PZ |
4353 | *enabled = 0; |
4354 | *running = 0; | |
4355 | ||
6f10581a | 4356 | mutex_lock(&event->child_mutex); |
01add3ea | 4357 | |
7d88962e | 4358 | (void)perf_event_read(event, false); |
01add3ea SB |
4359 | total += perf_event_count(event); |
4360 | ||
59ed446f PZ |
4361 | *enabled += event->total_time_enabled + |
4362 | atomic64_read(&event->child_total_time_enabled); | |
4363 | *running += event->total_time_running + | |
4364 | atomic64_read(&event->child_total_time_running); | |
4365 | ||
4366 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 4367 | (void)perf_event_read(child, false); |
01add3ea | 4368 | total += perf_event_count(child); |
59ed446f PZ |
4369 | *enabled += child->total_time_enabled; |
4370 | *running += child->total_time_running; | |
4371 | } | |
6f10581a | 4372 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
4373 | |
4374 | return total; | |
4375 | } | |
fb0459d7 | 4376 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 4377 | |
7d88962e | 4378 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 4379 | u64 read_format, u64 *values) |
3dab77fb | 4380 | { |
fa8c2693 PZ |
4381 | struct perf_event *sub; |
4382 | int n = 1; /* skip @nr */ | |
7d88962e | 4383 | int ret; |
f63a8daa | 4384 | |
7d88962e SB |
4385 | ret = perf_event_read(leader, true); |
4386 | if (ret) | |
4387 | return ret; | |
abf4868b | 4388 | |
fa8c2693 PZ |
4389 | /* |
4390 | * Since we co-schedule groups, {enabled,running} times of siblings | |
4391 | * will be identical to those of the leader, so we only publish one | |
4392 | * set. | |
4393 | */ | |
4394 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
4395 | values[n++] += leader->total_time_enabled + | |
4396 | atomic64_read(&leader->child_total_time_enabled); | |
4397 | } | |
3dab77fb | 4398 | |
fa8c2693 PZ |
4399 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
4400 | values[n++] += leader->total_time_running + | |
4401 | atomic64_read(&leader->child_total_time_running); | |
4402 | } | |
4403 | ||
4404 | /* | |
4405 | * Write {count,id} tuples for every sibling. | |
4406 | */ | |
4407 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
4408 | if (read_format & PERF_FORMAT_ID) |
4409 | values[n++] = primary_event_id(leader); | |
3dab77fb | 4410 | |
fa8c2693 PZ |
4411 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
4412 | values[n++] += perf_event_count(sub); | |
4413 | if (read_format & PERF_FORMAT_ID) | |
4414 | values[n++] = primary_event_id(sub); | |
4415 | } | |
7d88962e SB |
4416 | |
4417 | return 0; | |
fa8c2693 | 4418 | } |
3dab77fb | 4419 | |
fa8c2693 PZ |
4420 | static int perf_read_group(struct perf_event *event, |
4421 | u64 read_format, char __user *buf) | |
4422 | { | |
4423 | struct perf_event *leader = event->group_leader, *child; | |
4424 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 4425 | int ret; |
fa8c2693 | 4426 | u64 *values; |
3dab77fb | 4427 | |
fa8c2693 | 4428 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 4429 | |
fa8c2693 PZ |
4430 | values = kzalloc(event->read_size, GFP_KERNEL); |
4431 | if (!values) | |
4432 | return -ENOMEM; | |
3dab77fb | 4433 | |
fa8c2693 PZ |
4434 | values[0] = 1 + leader->nr_siblings; |
4435 | ||
4436 | /* | |
4437 | * By locking the child_mutex of the leader we effectively | |
4438 | * lock the child list of all siblings.. XXX explain how. | |
4439 | */ | |
4440 | mutex_lock(&leader->child_mutex); | |
abf4868b | 4441 | |
7d88962e SB |
4442 | ret = __perf_read_group_add(leader, read_format, values); |
4443 | if (ret) | |
4444 | goto unlock; | |
4445 | ||
4446 | list_for_each_entry(child, &leader->child_list, child_list) { | |
4447 | ret = __perf_read_group_add(child, read_format, values); | |
4448 | if (ret) | |
4449 | goto unlock; | |
4450 | } | |
abf4868b | 4451 | |
fa8c2693 | 4452 | mutex_unlock(&leader->child_mutex); |
abf4868b | 4453 | |
7d88962e | 4454 | ret = event->read_size; |
fa8c2693 PZ |
4455 | if (copy_to_user(buf, values, event->read_size)) |
4456 | ret = -EFAULT; | |
7d88962e | 4457 | goto out; |
fa8c2693 | 4458 | |
7d88962e SB |
4459 | unlock: |
4460 | mutex_unlock(&leader->child_mutex); | |
4461 | out: | |
fa8c2693 | 4462 | kfree(values); |
abf4868b | 4463 | return ret; |
3dab77fb PZ |
4464 | } |
4465 | ||
b15f495b | 4466 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
4467 | u64 read_format, char __user *buf) |
4468 | { | |
59ed446f | 4469 | u64 enabled, running; |
3dab77fb PZ |
4470 | u64 values[4]; |
4471 | int n = 0; | |
4472 | ||
59ed446f PZ |
4473 | values[n++] = perf_event_read_value(event, &enabled, &running); |
4474 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
4475 | values[n++] = enabled; | |
4476 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
4477 | values[n++] = running; | |
3dab77fb | 4478 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 4479 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
4480 | |
4481 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
4482 | return -EFAULT; | |
4483 | ||
4484 | return n * sizeof(u64); | |
4485 | } | |
4486 | ||
dc633982 JO |
4487 | static bool is_event_hup(struct perf_event *event) |
4488 | { | |
4489 | bool no_children; | |
4490 | ||
a69b0ca4 | 4491 | if (event->state > PERF_EVENT_STATE_EXIT) |
dc633982 JO |
4492 | return false; |
4493 | ||
4494 | mutex_lock(&event->child_mutex); | |
4495 | no_children = list_empty(&event->child_list); | |
4496 | mutex_unlock(&event->child_mutex); | |
4497 | return no_children; | |
4498 | } | |
4499 | ||
0793a61d | 4500 | /* |
cdd6c482 | 4501 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
4502 | */ |
4503 | static ssize_t | |
b15f495b | 4504 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 4505 | { |
cdd6c482 | 4506 | u64 read_format = event->attr.read_format; |
3dab77fb | 4507 | int ret; |
0793a61d | 4508 | |
3b6f9e5c | 4509 | /* |
cdd6c482 | 4510 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4511 | * error state (i.e. because it was pinned but it couldn't be |
4512 | * scheduled on to the CPU at some point). | |
4513 | */ | |
cdd6c482 | 4514 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4515 | return 0; |
4516 | ||
c320c7b7 | 4517 | if (count < event->read_size) |
3dab77fb PZ |
4518 | return -ENOSPC; |
4519 | ||
cdd6c482 | 4520 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4521 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4522 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4523 | else |
b15f495b | 4524 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4525 | |
3dab77fb | 4526 | return ret; |
0793a61d TG |
4527 | } |
4528 | ||
0793a61d TG |
4529 | static ssize_t |
4530 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4531 | { | |
cdd6c482 | 4532 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4533 | struct perf_event_context *ctx; |
4534 | int ret; | |
0793a61d | 4535 | |
f63a8daa | 4536 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4537 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4538 | perf_event_ctx_unlock(event, ctx); |
4539 | ||
4540 | return ret; | |
0793a61d TG |
4541 | } |
4542 | ||
4543 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4544 | { | |
cdd6c482 | 4545 | struct perf_event *event = file->private_data; |
76369139 | 4546 | struct ring_buffer *rb; |
61b67684 | 4547 | unsigned int events = POLLHUP; |
c7138f37 | 4548 | |
e708d7ad | 4549 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4550 | |
dc633982 | 4551 | if (is_event_hup(event)) |
179033b3 | 4552 | return events; |
c7138f37 | 4553 | |
10c6db11 | 4554 | /* |
9bb5d40c PZ |
4555 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4556 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4557 | */ |
4558 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4559 | rb = event->rb; |
4560 | if (rb) | |
76369139 | 4561 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4562 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4563 | return events; |
4564 | } | |
4565 | ||
f63a8daa | 4566 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4567 | { |
7d88962e | 4568 | (void)perf_event_read(event, false); |
e7850595 | 4569 | local64_set(&event->count, 0); |
cdd6c482 | 4570 | perf_event_update_userpage(event); |
3df5edad PZ |
4571 | } |
4572 | ||
c93f7669 | 4573 | /* |
cdd6c482 IM |
4574 | * Holding the top-level event's child_mutex means that any |
4575 | * descendant process that has inherited this event will block | |
8ba289b8 | 4576 | * in perf_event_exit_event() if it goes to exit, thus satisfying the |
cdd6c482 | 4577 | * task existence requirements of perf_event_enable/disable. |
c93f7669 | 4578 | */ |
cdd6c482 IM |
4579 | static void perf_event_for_each_child(struct perf_event *event, |
4580 | void (*func)(struct perf_event *)) | |
3df5edad | 4581 | { |
cdd6c482 | 4582 | struct perf_event *child; |
3df5edad | 4583 | |
cdd6c482 | 4584 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4585 | |
cdd6c482 IM |
4586 | mutex_lock(&event->child_mutex); |
4587 | func(event); | |
4588 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4589 | func(child); |
cdd6c482 | 4590 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4591 | } |
4592 | ||
cdd6c482 IM |
4593 | static void perf_event_for_each(struct perf_event *event, |
4594 | void (*func)(struct perf_event *)) | |
3df5edad | 4595 | { |
cdd6c482 IM |
4596 | struct perf_event_context *ctx = event->ctx; |
4597 | struct perf_event *sibling; | |
3df5edad | 4598 | |
f63a8daa PZ |
4599 | lockdep_assert_held(&ctx->mutex); |
4600 | ||
cdd6c482 | 4601 | event = event->group_leader; |
75f937f2 | 4602 | |
cdd6c482 | 4603 | perf_event_for_each_child(event, func); |
cdd6c482 | 4604 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4605 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4606 | } |
4607 | ||
fae3fde6 PZ |
4608 | static void __perf_event_period(struct perf_event *event, |
4609 | struct perf_cpu_context *cpuctx, | |
4610 | struct perf_event_context *ctx, | |
4611 | void *info) | |
c7999c6f | 4612 | { |
fae3fde6 | 4613 | u64 value = *((u64 *)info); |
c7999c6f | 4614 | bool active; |
08247e31 | 4615 | |
cdd6c482 | 4616 | if (event->attr.freq) { |
cdd6c482 | 4617 | event->attr.sample_freq = value; |
08247e31 | 4618 | } else { |
cdd6c482 IM |
4619 | event->attr.sample_period = value; |
4620 | event->hw.sample_period = value; | |
08247e31 | 4621 | } |
bad7192b PZ |
4622 | |
4623 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4624 | if (active) { | |
4625 | perf_pmu_disable(ctx->pmu); | |
1e02cd40 PZ |
4626 | /* |
4627 | * We could be throttled; unthrottle now to avoid the tick | |
4628 | * trying to unthrottle while we already re-started the event. | |
4629 | */ | |
4630 | if (event->hw.interrupts == MAX_INTERRUPTS) { | |
4631 | event->hw.interrupts = 0; | |
4632 | perf_log_throttle(event, 1); | |
4633 | } | |
bad7192b PZ |
4634 | event->pmu->stop(event, PERF_EF_UPDATE); |
4635 | } | |
4636 | ||
4637 | local64_set(&event->hw.period_left, 0); | |
4638 | ||
4639 | if (active) { | |
4640 | event->pmu->start(event, PERF_EF_RELOAD); | |
4641 | perf_pmu_enable(ctx->pmu); | |
4642 | } | |
c7999c6f PZ |
4643 | } |
4644 | ||
4645 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4646 | { | |
c7999c6f PZ |
4647 | u64 value; |
4648 | ||
4649 | if (!is_sampling_event(event)) | |
4650 | return -EINVAL; | |
4651 | ||
4652 | if (copy_from_user(&value, arg, sizeof(value))) | |
4653 | return -EFAULT; | |
4654 | ||
4655 | if (!value) | |
4656 | return -EINVAL; | |
4657 | ||
4658 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4659 | return -EINVAL; | |
4660 | ||
fae3fde6 | 4661 | event_function_call(event, __perf_event_period, &value); |
08247e31 | 4662 | |
c7999c6f | 4663 | return 0; |
08247e31 PZ |
4664 | } |
4665 | ||
ac9721f3 PZ |
4666 | static const struct file_operations perf_fops; |
4667 | ||
2903ff01 | 4668 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4669 | { |
2903ff01 AV |
4670 | struct fd f = fdget(fd); |
4671 | if (!f.file) | |
4672 | return -EBADF; | |
ac9721f3 | 4673 | |
2903ff01 AV |
4674 | if (f.file->f_op != &perf_fops) { |
4675 | fdput(f); | |
4676 | return -EBADF; | |
ac9721f3 | 4677 | } |
2903ff01 AV |
4678 | *p = f; |
4679 | return 0; | |
ac9721f3 PZ |
4680 | } |
4681 | ||
4682 | static int perf_event_set_output(struct perf_event *event, | |
4683 | struct perf_event *output_event); | |
6fb2915d | 4684 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4685 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4686 | |
f63a8daa | 4687 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4688 | { |
cdd6c482 | 4689 | void (*func)(struct perf_event *); |
3df5edad | 4690 | u32 flags = arg; |
d859e29f PM |
4691 | |
4692 | switch (cmd) { | |
cdd6c482 | 4693 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4694 | func = _perf_event_enable; |
d859e29f | 4695 | break; |
cdd6c482 | 4696 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4697 | func = _perf_event_disable; |
79f14641 | 4698 | break; |
cdd6c482 | 4699 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4700 | func = _perf_event_reset; |
6de6a7b9 | 4701 | break; |
3df5edad | 4702 | |
cdd6c482 | 4703 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4704 | return _perf_event_refresh(event, arg); |
08247e31 | 4705 | |
cdd6c482 IM |
4706 | case PERF_EVENT_IOC_PERIOD: |
4707 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4708 | |
cf4957f1 JO |
4709 | case PERF_EVENT_IOC_ID: |
4710 | { | |
4711 | u64 id = primary_event_id(event); | |
4712 | ||
4713 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4714 | return -EFAULT; | |
4715 | return 0; | |
4716 | } | |
4717 | ||
cdd6c482 | 4718 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4719 | { |
ac9721f3 | 4720 | int ret; |
ac9721f3 | 4721 | if (arg != -1) { |
2903ff01 AV |
4722 | struct perf_event *output_event; |
4723 | struct fd output; | |
4724 | ret = perf_fget_light(arg, &output); | |
4725 | if (ret) | |
4726 | return ret; | |
4727 | output_event = output.file->private_data; | |
4728 | ret = perf_event_set_output(event, output_event); | |
4729 | fdput(output); | |
4730 | } else { | |
4731 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4732 | } |
ac9721f3 PZ |
4733 | return ret; |
4734 | } | |
a4be7c27 | 4735 | |
6fb2915d LZ |
4736 | case PERF_EVENT_IOC_SET_FILTER: |
4737 | return perf_event_set_filter(event, (void __user *)arg); | |
4738 | ||
2541517c AS |
4739 | case PERF_EVENT_IOC_SET_BPF: |
4740 | return perf_event_set_bpf_prog(event, arg); | |
4741 | ||
86e7972f WN |
4742 | case PERF_EVENT_IOC_PAUSE_OUTPUT: { |
4743 | struct ring_buffer *rb; | |
4744 | ||
4745 | rcu_read_lock(); | |
4746 | rb = rcu_dereference(event->rb); | |
4747 | if (!rb || !rb->nr_pages) { | |
4748 | rcu_read_unlock(); | |
4749 | return -EINVAL; | |
4750 | } | |
4751 | rb_toggle_paused(rb, !!arg); | |
4752 | rcu_read_unlock(); | |
4753 | return 0; | |
4754 | } | |
d859e29f | 4755 | default: |
3df5edad | 4756 | return -ENOTTY; |
d859e29f | 4757 | } |
3df5edad PZ |
4758 | |
4759 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4760 | perf_event_for_each(event, func); |
3df5edad | 4761 | else |
cdd6c482 | 4762 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4763 | |
4764 | return 0; | |
d859e29f PM |
4765 | } |
4766 | ||
f63a8daa PZ |
4767 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4768 | { | |
4769 | struct perf_event *event = file->private_data; | |
4770 | struct perf_event_context *ctx; | |
4771 | long ret; | |
4772 | ||
4773 | ctx = perf_event_ctx_lock(event); | |
4774 | ret = _perf_ioctl(event, cmd, arg); | |
4775 | perf_event_ctx_unlock(event, ctx); | |
4776 | ||
4777 | return ret; | |
4778 | } | |
4779 | ||
b3f20785 PM |
4780 | #ifdef CONFIG_COMPAT |
4781 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4782 | unsigned long arg) | |
4783 | { | |
4784 | switch (_IOC_NR(cmd)) { | |
4785 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4786 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4787 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4788 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4789 | cmd &= ~IOCSIZE_MASK; | |
4790 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4791 | } | |
4792 | break; | |
4793 | } | |
4794 | return perf_ioctl(file, cmd, arg); | |
4795 | } | |
4796 | #else | |
4797 | # define perf_compat_ioctl NULL | |
4798 | #endif | |
4799 | ||
cdd6c482 | 4800 | int perf_event_task_enable(void) |
771d7cde | 4801 | { |
f63a8daa | 4802 | struct perf_event_context *ctx; |
cdd6c482 | 4803 | struct perf_event *event; |
771d7cde | 4804 | |
cdd6c482 | 4805 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4806 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4807 | ctx = perf_event_ctx_lock(event); | |
4808 | perf_event_for_each_child(event, _perf_event_enable); | |
4809 | perf_event_ctx_unlock(event, ctx); | |
4810 | } | |
cdd6c482 | 4811 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4812 | |
4813 | return 0; | |
4814 | } | |
4815 | ||
cdd6c482 | 4816 | int perf_event_task_disable(void) |
771d7cde | 4817 | { |
f63a8daa | 4818 | struct perf_event_context *ctx; |
cdd6c482 | 4819 | struct perf_event *event; |
771d7cde | 4820 | |
cdd6c482 | 4821 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4822 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4823 | ctx = perf_event_ctx_lock(event); | |
4824 | perf_event_for_each_child(event, _perf_event_disable); | |
4825 | perf_event_ctx_unlock(event, ctx); | |
4826 | } | |
cdd6c482 | 4827 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4828 | |
4829 | return 0; | |
4830 | } | |
4831 | ||
cdd6c482 | 4832 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4833 | { |
a4eaf7f1 PZ |
4834 | if (event->hw.state & PERF_HES_STOPPED) |
4835 | return 0; | |
4836 | ||
cdd6c482 | 4837 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4838 | return 0; |
4839 | ||
35edc2a5 | 4840 | return event->pmu->event_idx(event); |
194002b2 PZ |
4841 | } |
4842 | ||
c4794295 | 4843 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4844 | u64 *now, |
7f310a5d EM |
4845 | u64 *enabled, |
4846 | u64 *running) | |
c4794295 | 4847 | { |
e3f3541c | 4848 | u64 ctx_time; |
c4794295 | 4849 | |
e3f3541c PZ |
4850 | *now = perf_clock(); |
4851 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4852 | *enabled = ctx_time - event->tstamp_enabled; |
4853 | *running = ctx_time - event->tstamp_running; | |
4854 | } | |
4855 | ||
fa731587 PZ |
4856 | static void perf_event_init_userpage(struct perf_event *event) |
4857 | { | |
4858 | struct perf_event_mmap_page *userpg; | |
4859 | struct ring_buffer *rb; | |
4860 | ||
4861 | rcu_read_lock(); | |
4862 | rb = rcu_dereference(event->rb); | |
4863 | if (!rb) | |
4864 | goto unlock; | |
4865 | ||
4866 | userpg = rb->user_page; | |
4867 | ||
4868 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4869 | userpg->cap_bit0_is_deprecated = 1; | |
4870 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4871 | userpg->data_offset = PAGE_SIZE; |
4872 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4873 | |
4874 | unlock: | |
4875 | rcu_read_unlock(); | |
4876 | } | |
4877 | ||
c1317ec2 AL |
4878 | void __weak arch_perf_update_userpage( |
4879 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4880 | { |
4881 | } | |
4882 | ||
38ff667b PZ |
4883 | /* |
4884 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4885 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4886 | * code calls this from NMI context. | |
4887 | */ | |
cdd6c482 | 4888 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4889 | { |
cdd6c482 | 4890 | struct perf_event_mmap_page *userpg; |
76369139 | 4891 | struct ring_buffer *rb; |
e3f3541c | 4892 | u64 enabled, running, now; |
38ff667b PZ |
4893 | |
4894 | rcu_read_lock(); | |
5ec4c599 PZ |
4895 | rb = rcu_dereference(event->rb); |
4896 | if (!rb) | |
4897 | goto unlock; | |
4898 | ||
0d641208 EM |
4899 | /* |
4900 | * compute total_time_enabled, total_time_running | |
4901 | * based on snapshot values taken when the event | |
4902 | * was last scheduled in. | |
4903 | * | |
4904 | * we cannot simply called update_context_time() | |
4905 | * because of locking issue as we can be called in | |
4906 | * NMI context | |
4907 | */ | |
e3f3541c | 4908 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4909 | |
76369139 | 4910 | userpg = rb->user_page; |
7b732a75 PZ |
4911 | /* |
4912 | * Disable preemption so as to not let the corresponding user-space | |
4913 | * spin too long if we get preempted. | |
4914 | */ | |
4915 | preempt_disable(); | |
37d81828 | 4916 | ++userpg->lock; |
92f22a38 | 4917 | barrier(); |
cdd6c482 | 4918 | userpg->index = perf_event_index(event); |
b5e58793 | 4919 | userpg->offset = perf_event_count(event); |
365a4038 | 4920 | if (userpg->index) |
e7850595 | 4921 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4922 | |
0d641208 | 4923 | userpg->time_enabled = enabled + |
cdd6c482 | 4924 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4925 | |
0d641208 | 4926 | userpg->time_running = running + |
cdd6c482 | 4927 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4928 | |
c1317ec2 | 4929 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4930 | |
92f22a38 | 4931 | barrier(); |
37d81828 | 4932 | ++userpg->lock; |
7b732a75 | 4933 | preempt_enable(); |
38ff667b | 4934 | unlock: |
7b732a75 | 4935 | rcu_read_unlock(); |
37d81828 PM |
4936 | } |
4937 | ||
11bac800 | 4938 | static int perf_mmap_fault(struct vm_fault *vmf) |
906010b2 | 4939 | { |
11bac800 | 4940 | struct perf_event *event = vmf->vma->vm_file->private_data; |
76369139 | 4941 | struct ring_buffer *rb; |
906010b2 PZ |
4942 | int ret = VM_FAULT_SIGBUS; |
4943 | ||
4944 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4945 | if (vmf->pgoff == 0) | |
4946 | ret = 0; | |
4947 | return ret; | |
4948 | } | |
4949 | ||
4950 | rcu_read_lock(); | |
76369139 FW |
4951 | rb = rcu_dereference(event->rb); |
4952 | if (!rb) | |
906010b2 PZ |
4953 | goto unlock; |
4954 | ||
4955 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4956 | goto unlock; | |
4957 | ||
76369139 | 4958 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4959 | if (!vmf->page) |
4960 | goto unlock; | |
4961 | ||
4962 | get_page(vmf->page); | |
11bac800 | 4963 | vmf->page->mapping = vmf->vma->vm_file->f_mapping; |
906010b2 PZ |
4964 | vmf->page->index = vmf->pgoff; |
4965 | ||
4966 | ret = 0; | |
4967 | unlock: | |
4968 | rcu_read_unlock(); | |
4969 | ||
4970 | return ret; | |
4971 | } | |
4972 | ||
10c6db11 PZ |
4973 | static void ring_buffer_attach(struct perf_event *event, |
4974 | struct ring_buffer *rb) | |
4975 | { | |
b69cf536 | 4976 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4977 | unsigned long flags; |
4978 | ||
b69cf536 PZ |
4979 | if (event->rb) { |
4980 | /* | |
4981 | * Should be impossible, we set this when removing | |
4982 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4983 | */ | |
4984 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4985 | |
b69cf536 | 4986 | old_rb = event->rb; |
b69cf536 PZ |
4987 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4988 | list_del_rcu(&event->rb_entry); | |
4989 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4990 | |
2f993cf0 ON |
4991 | event->rcu_batches = get_state_synchronize_rcu(); |
4992 | event->rcu_pending = 1; | |
b69cf536 | 4993 | } |
10c6db11 | 4994 | |
b69cf536 | 4995 | if (rb) { |
2f993cf0 ON |
4996 | if (event->rcu_pending) { |
4997 | cond_synchronize_rcu(event->rcu_batches); | |
4998 | event->rcu_pending = 0; | |
4999 | } | |
5000 | ||
b69cf536 PZ |
5001 | spin_lock_irqsave(&rb->event_lock, flags); |
5002 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
5003 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
5004 | } | |
5005 | ||
767ae086 AS |
5006 | /* |
5007 | * Avoid racing with perf_mmap_close(AUX): stop the event | |
5008 | * before swizzling the event::rb pointer; if it's getting | |
5009 | * unmapped, its aux_mmap_count will be 0 and it won't | |
5010 | * restart. See the comment in __perf_pmu_output_stop(). | |
5011 | * | |
5012 | * Data will inevitably be lost when set_output is done in | |
5013 | * mid-air, but then again, whoever does it like this is | |
5014 | * not in for the data anyway. | |
5015 | */ | |
5016 | if (has_aux(event)) | |
5017 | perf_event_stop(event, 0); | |
5018 | ||
b69cf536 PZ |
5019 | rcu_assign_pointer(event->rb, rb); |
5020 | ||
5021 | if (old_rb) { | |
5022 | ring_buffer_put(old_rb); | |
5023 | /* | |
5024 | * Since we detached before setting the new rb, so that we | |
5025 | * could attach the new rb, we could have missed a wakeup. | |
5026 | * Provide it now. | |
5027 | */ | |
5028 | wake_up_all(&event->waitq); | |
5029 | } | |
10c6db11 PZ |
5030 | } |
5031 | ||
5032 | static void ring_buffer_wakeup(struct perf_event *event) | |
5033 | { | |
5034 | struct ring_buffer *rb; | |
5035 | ||
5036 | rcu_read_lock(); | |
5037 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
5038 | if (rb) { |
5039 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
5040 | wake_up_all(&event->waitq); | |
5041 | } | |
10c6db11 PZ |
5042 | rcu_read_unlock(); |
5043 | } | |
5044 | ||
fdc26706 | 5045 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 5046 | { |
76369139 | 5047 | struct ring_buffer *rb; |
7b732a75 | 5048 | |
ac9721f3 | 5049 | rcu_read_lock(); |
76369139 FW |
5050 | rb = rcu_dereference(event->rb); |
5051 | if (rb) { | |
5052 | if (!atomic_inc_not_zero(&rb->refcount)) | |
5053 | rb = NULL; | |
ac9721f3 PZ |
5054 | } |
5055 | rcu_read_unlock(); | |
5056 | ||
76369139 | 5057 | return rb; |
ac9721f3 PZ |
5058 | } |
5059 | ||
fdc26706 | 5060 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 5061 | { |
76369139 | 5062 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 5063 | return; |
7b732a75 | 5064 | |
9bb5d40c | 5065 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 5066 | |
76369139 | 5067 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
5068 | } |
5069 | ||
5070 | static void perf_mmap_open(struct vm_area_struct *vma) | |
5071 | { | |
cdd6c482 | 5072 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 5073 | |
cdd6c482 | 5074 | atomic_inc(&event->mmap_count); |
9bb5d40c | 5075 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 5076 | |
45bfb2e5 PZ |
5077 | if (vma->vm_pgoff) |
5078 | atomic_inc(&event->rb->aux_mmap_count); | |
5079 | ||
1e0fb9ec AL |
5080 | if (event->pmu->event_mapped) |
5081 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
5082 | } |
5083 | ||
95ff4ca2 AS |
5084 | static void perf_pmu_output_stop(struct perf_event *event); |
5085 | ||
9bb5d40c PZ |
5086 | /* |
5087 | * A buffer can be mmap()ed multiple times; either directly through the same | |
5088 | * event, or through other events by use of perf_event_set_output(). | |
5089 | * | |
5090 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
5091 | * the buffer here, where we still have a VM context. This means we need | |
5092 | * to detach all events redirecting to us. | |
5093 | */ | |
7b732a75 PZ |
5094 | static void perf_mmap_close(struct vm_area_struct *vma) |
5095 | { | |
cdd6c482 | 5096 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 5097 | |
b69cf536 | 5098 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
5099 | struct user_struct *mmap_user = rb->mmap_user; |
5100 | int mmap_locked = rb->mmap_locked; | |
5101 | unsigned long size = perf_data_size(rb); | |
789f90fc | 5102 | |
1e0fb9ec AL |
5103 | if (event->pmu->event_unmapped) |
5104 | event->pmu->event_unmapped(event); | |
5105 | ||
45bfb2e5 PZ |
5106 | /* |
5107 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
5108 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
5109 | * serialize with perf_mmap here. | |
5110 | */ | |
5111 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
5112 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
95ff4ca2 AS |
5113 | /* |
5114 | * Stop all AUX events that are writing to this buffer, | |
5115 | * so that we can free its AUX pages and corresponding PMU | |
5116 | * data. Note that after rb::aux_mmap_count dropped to zero, | |
5117 | * they won't start any more (see perf_aux_output_begin()). | |
5118 | */ | |
5119 | perf_pmu_output_stop(event); | |
5120 | ||
5121 | /* now it's safe to free the pages */ | |
45bfb2e5 PZ |
5122 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); |
5123 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
5124 | ||
95ff4ca2 | 5125 | /* this has to be the last one */ |
45bfb2e5 | 5126 | rb_free_aux(rb); |
95ff4ca2 AS |
5127 | WARN_ON_ONCE(atomic_read(&rb->aux_refcount)); |
5128 | ||
45bfb2e5 PZ |
5129 | mutex_unlock(&event->mmap_mutex); |
5130 | } | |
5131 | ||
9bb5d40c PZ |
5132 | atomic_dec(&rb->mmap_count); |
5133 | ||
5134 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 5135 | goto out_put; |
9bb5d40c | 5136 | |
b69cf536 | 5137 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
5138 | mutex_unlock(&event->mmap_mutex); |
5139 | ||
5140 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
5141 | if (atomic_read(&rb->mmap_count)) |
5142 | goto out_put; | |
ac9721f3 | 5143 | |
9bb5d40c PZ |
5144 | /* |
5145 | * No other mmap()s, detach from all other events that might redirect | |
5146 | * into the now unreachable buffer. Somewhat complicated by the | |
5147 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
5148 | */ | |
5149 | again: | |
5150 | rcu_read_lock(); | |
5151 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
5152 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
5153 | /* | |
5154 | * This event is en-route to free_event() which will | |
5155 | * detach it and remove it from the list. | |
5156 | */ | |
5157 | continue; | |
5158 | } | |
5159 | rcu_read_unlock(); | |
789f90fc | 5160 | |
9bb5d40c PZ |
5161 | mutex_lock(&event->mmap_mutex); |
5162 | /* | |
5163 | * Check we didn't race with perf_event_set_output() which can | |
5164 | * swizzle the rb from under us while we were waiting to | |
5165 | * acquire mmap_mutex. | |
5166 | * | |
5167 | * If we find a different rb; ignore this event, a next | |
5168 | * iteration will no longer find it on the list. We have to | |
5169 | * still restart the iteration to make sure we're not now | |
5170 | * iterating the wrong list. | |
5171 | */ | |
b69cf536 PZ |
5172 | if (event->rb == rb) |
5173 | ring_buffer_attach(event, NULL); | |
5174 | ||
cdd6c482 | 5175 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 5176 | put_event(event); |
ac9721f3 | 5177 | |
9bb5d40c PZ |
5178 | /* |
5179 | * Restart the iteration; either we're on the wrong list or | |
5180 | * destroyed its integrity by doing a deletion. | |
5181 | */ | |
5182 | goto again; | |
7b732a75 | 5183 | } |
9bb5d40c PZ |
5184 | rcu_read_unlock(); |
5185 | ||
5186 | /* | |
5187 | * It could be there's still a few 0-ref events on the list; they'll | |
5188 | * get cleaned up by free_event() -- they'll also still have their | |
5189 | * ref on the rb and will free it whenever they are done with it. | |
5190 | * | |
5191 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
5192 | * undo the VM accounting. | |
5193 | */ | |
5194 | ||
5195 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
5196 | vma->vm_mm->pinned_vm -= mmap_locked; | |
5197 | free_uid(mmap_user); | |
5198 | ||
b69cf536 | 5199 | out_put: |
9bb5d40c | 5200 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
5201 | } |
5202 | ||
f0f37e2f | 5203 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 5204 | .open = perf_mmap_open, |
45bfb2e5 | 5205 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
5206 | .fault = perf_mmap_fault, |
5207 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
5208 | }; |
5209 | ||
5210 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
5211 | { | |
cdd6c482 | 5212 | struct perf_event *event = file->private_data; |
22a4f650 | 5213 | unsigned long user_locked, user_lock_limit; |
789f90fc | 5214 | struct user_struct *user = current_user(); |
22a4f650 | 5215 | unsigned long locked, lock_limit; |
45bfb2e5 | 5216 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
5217 | unsigned long vma_size; |
5218 | unsigned long nr_pages; | |
45bfb2e5 | 5219 | long user_extra = 0, extra = 0; |
d57e34fd | 5220 | int ret = 0, flags = 0; |
37d81828 | 5221 | |
c7920614 PZ |
5222 | /* |
5223 | * Don't allow mmap() of inherited per-task counters. This would | |
5224 | * create a performance issue due to all children writing to the | |
76369139 | 5225 | * same rb. |
c7920614 PZ |
5226 | */ |
5227 | if (event->cpu == -1 && event->attr.inherit) | |
5228 | return -EINVAL; | |
5229 | ||
43a21ea8 | 5230 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 5231 | return -EINVAL; |
7b732a75 PZ |
5232 | |
5233 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
5234 | |
5235 | if (vma->vm_pgoff == 0) { | |
5236 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
5237 | } else { | |
5238 | /* | |
5239 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
5240 | * mapped, all subsequent mappings should have the same size | |
5241 | * and offset. Must be above the normal perf buffer. | |
5242 | */ | |
5243 | u64 aux_offset, aux_size; | |
5244 | ||
5245 | if (!event->rb) | |
5246 | return -EINVAL; | |
5247 | ||
5248 | nr_pages = vma_size / PAGE_SIZE; | |
5249 | ||
5250 | mutex_lock(&event->mmap_mutex); | |
5251 | ret = -EINVAL; | |
5252 | ||
5253 | rb = event->rb; | |
5254 | if (!rb) | |
5255 | goto aux_unlock; | |
5256 | ||
5257 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
5258 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
5259 | ||
5260 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
5261 | goto aux_unlock; | |
5262 | ||
5263 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
5264 | goto aux_unlock; | |
5265 | ||
5266 | /* already mapped with a different offset */ | |
5267 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
5268 | goto aux_unlock; | |
5269 | ||
5270 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
5271 | goto aux_unlock; | |
5272 | ||
5273 | /* already mapped with a different size */ | |
5274 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
5275 | goto aux_unlock; | |
5276 | ||
5277 | if (!is_power_of_2(nr_pages)) | |
5278 | goto aux_unlock; | |
5279 | ||
5280 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
5281 | goto aux_unlock; | |
5282 | ||
5283 | if (rb_has_aux(rb)) { | |
5284 | atomic_inc(&rb->aux_mmap_count); | |
5285 | ret = 0; | |
5286 | goto unlock; | |
5287 | } | |
5288 | ||
5289 | atomic_set(&rb->aux_mmap_count, 1); | |
5290 | user_extra = nr_pages; | |
5291 | ||
5292 | goto accounting; | |
5293 | } | |
7b732a75 | 5294 | |
7730d865 | 5295 | /* |
76369139 | 5296 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
5297 | * can do bitmasks instead of modulo. |
5298 | */ | |
2ed11312 | 5299 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
5300 | return -EINVAL; |
5301 | ||
7b732a75 | 5302 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
5303 | return -EINVAL; |
5304 | ||
cdd6c482 | 5305 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 5306 | again: |
cdd6c482 | 5307 | mutex_lock(&event->mmap_mutex); |
76369139 | 5308 | if (event->rb) { |
9bb5d40c | 5309 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 5310 | ret = -EINVAL; |
9bb5d40c PZ |
5311 | goto unlock; |
5312 | } | |
5313 | ||
5314 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
5315 | /* | |
5316 | * Raced against perf_mmap_close() through | |
5317 | * perf_event_set_output(). Try again, hope for better | |
5318 | * luck. | |
5319 | */ | |
5320 | mutex_unlock(&event->mmap_mutex); | |
5321 | goto again; | |
5322 | } | |
5323 | ||
ebb3c4c4 PZ |
5324 | goto unlock; |
5325 | } | |
5326 | ||
789f90fc | 5327 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
5328 | |
5329 | accounting: | |
cdd6c482 | 5330 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
5331 | |
5332 | /* | |
5333 | * Increase the limit linearly with more CPUs: | |
5334 | */ | |
5335 | user_lock_limit *= num_online_cpus(); | |
5336 | ||
789f90fc | 5337 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 5338 | |
789f90fc PZ |
5339 | if (user_locked > user_lock_limit) |
5340 | extra = user_locked - user_lock_limit; | |
7b732a75 | 5341 | |
78d7d407 | 5342 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 5343 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 5344 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 5345 | |
459ec28a IM |
5346 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
5347 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
5348 | ret = -EPERM; |
5349 | goto unlock; | |
5350 | } | |
7b732a75 | 5351 | |
45bfb2e5 | 5352 | WARN_ON(!rb && event->rb); |
906010b2 | 5353 | |
d57e34fd | 5354 | if (vma->vm_flags & VM_WRITE) |
76369139 | 5355 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 5356 | |
76369139 | 5357 | if (!rb) { |
45bfb2e5 PZ |
5358 | rb = rb_alloc(nr_pages, |
5359 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
5360 | event->cpu, flags); | |
26cb63ad | 5361 | |
45bfb2e5 PZ |
5362 | if (!rb) { |
5363 | ret = -ENOMEM; | |
5364 | goto unlock; | |
5365 | } | |
43a21ea8 | 5366 | |
45bfb2e5 PZ |
5367 | atomic_set(&rb->mmap_count, 1); |
5368 | rb->mmap_user = get_current_user(); | |
5369 | rb->mmap_locked = extra; | |
26cb63ad | 5370 | |
45bfb2e5 | 5371 | ring_buffer_attach(event, rb); |
ac9721f3 | 5372 | |
45bfb2e5 PZ |
5373 | perf_event_init_userpage(event); |
5374 | perf_event_update_userpage(event); | |
5375 | } else { | |
1a594131 AS |
5376 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
5377 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
5378 | if (!ret) |
5379 | rb->aux_mmap_locked = extra; | |
5380 | } | |
9a0f05cb | 5381 | |
ebb3c4c4 | 5382 | unlock: |
45bfb2e5 PZ |
5383 | if (!ret) { |
5384 | atomic_long_add(user_extra, &user->locked_vm); | |
5385 | vma->vm_mm->pinned_vm += extra; | |
5386 | ||
ac9721f3 | 5387 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
5388 | } else if (rb) { |
5389 | atomic_dec(&rb->mmap_count); | |
5390 | } | |
5391 | aux_unlock: | |
cdd6c482 | 5392 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 5393 | |
9bb5d40c PZ |
5394 | /* |
5395 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
5396 | * vma. | |
5397 | */ | |
26cb63ad | 5398 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 5399 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 5400 | |
1e0fb9ec AL |
5401 | if (event->pmu->event_mapped) |
5402 | event->pmu->event_mapped(event); | |
5403 | ||
7b732a75 | 5404 | return ret; |
37d81828 PM |
5405 | } |
5406 | ||
3c446b3d PZ |
5407 | static int perf_fasync(int fd, struct file *filp, int on) |
5408 | { | |
496ad9aa | 5409 | struct inode *inode = file_inode(filp); |
cdd6c482 | 5410 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
5411 | int retval; |
5412 | ||
5955102c | 5413 | inode_lock(inode); |
cdd6c482 | 5414 | retval = fasync_helper(fd, filp, on, &event->fasync); |
5955102c | 5415 | inode_unlock(inode); |
3c446b3d PZ |
5416 | |
5417 | if (retval < 0) | |
5418 | return retval; | |
5419 | ||
5420 | return 0; | |
5421 | } | |
5422 | ||
0793a61d | 5423 | static const struct file_operations perf_fops = { |
3326c1ce | 5424 | .llseek = no_llseek, |
0793a61d TG |
5425 | .release = perf_release, |
5426 | .read = perf_read, | |
5427 | .poll = perf_poll, | |
d859e29f | 5428 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 5429 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 5430 | .mmap = perf_mmap, |
3c446b3d | 5431 | .fasync = perf_fasync, |
0793a61d TG |
5432 | }; |
5433 | ||
925d519a | 5434 | /* |
cdd6c482 | 5435 | * Perf event wakeup |
925d519a PZ |
5436 | * |
5437 | * If there's data, ensure we set the poll() state and publish everything | |
5438 | * to user-space before waking everybody up. | |
5439 | */ | |
5440 | ||
fed66e2c PZ |
5441 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
5442 | { | |
5443 | /* only the parent has fasync state */ | |
5444 | if (event->parent) | |
5445 | event = event->parent; | |
5446 | return &event->fasync; | |
5447 | } | |
5448 | ||
cdd6c482 | 5449 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 5450 | { |
10c6db11 | 5451 | ring_buffer_wakeup(event); |
4c9e2542 | 5452 | |
cdd6c482 | 5453 | if (event->pending_kill) { |
fed66e2c | 5454 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 5455 | event->pending_kill = 0; |
4c9e2542 | 5456 | } |
925d519a PZ |
5457 | } |
5458 | ||
e360adbe | 5459 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 5460 | { |
cdd6c482 IM |
5461 | struct perf_event *event = container_of(entry, |
5462 | struct perf_event, pending); | |
d525211f PZ |
5463 | int rctx; |
5464 | ||
5465 | rctx = perf_swevent_get_recursion_context(); | |
5466 | /* | |
5467 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
5468 | * and we won't recurse 'further'. | |
5469 | */ | |
79f14641 | 5470 | |
cdd6c482 IM |
5471 | if (event->pending_disable) { |
5472 | event->pending_disable = 0; | |
fae3fde6 | 5473 | perf_event_disable_local(event); |
79f14641 PZ |
5474 | } |
5475 | ||
cdd6c482 IM |
5476 | if (event->pending_wakeup) { |
5477 | event->pending_wakeup = 0; | |
5478 | perf_event_wakeup(event); | |
79f14641 | 5479 | } |
d525211f PZ |
5480 | |
5481 | if (rctx >= 0) | |
5482 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
5483 | } |
5484 | ||
39447b38 ZY |
5485 | /* |
5486 | * We assume there is only KVM supporting the callbacks. | |
5487 | * Later on, we might change it to a list if there is | |
5488 | * another virtualization implementation supporting the callbacks. | |
5489 | */ | |
5490 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
5491 | ||
5492 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5493 | { | |
5494 | perf_guest_cbs = cbs; | |
5495 | return 0; | |
5496 | } | |
5497 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
5498 | ||
5499 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
5500 | { | |
5501 | perf_guest_cbs = NULL; | |
5502 | return 0; | |
5503 | } | |
5504 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
5505 | ||
4018994f JO |
5506 | static void |
5507 | perf_output_sample_regs(struct perf_output_handle *handle, | |
5508 | struct pt_regs *regs, u64 mask) | |
5509 | { | |
5510 | int bit; | |
29dd3288 | 5511 | DECLARE_BITMAP(_mask, 64); |
4018994f | 5512 | |
29dd3288 MS |
5513 | bitmap_from_u64(_mask, mask); |
5514 | for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) { | |
4018994f JO |
5515 | u64 val; |
5516 | ||
5517 | val = perf_reg_value(regs, bit); | |
5518 | perf_output_put(handle, val); | |
5519 | } | |
5520 | } | |
5521 | ||
60e2364e | 5522 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
5523 | struct pt_regs *regs, |
5524 | struct pt_regs *regs_user_copy) | |
4018994f | 5525 | { |
88a7c26a AL |
5526 | if (user_mode(regs)) { |
5527 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 5528 | regs_user->regs = regs; |
88a7c26a AL |
5529 | } else if (current->mm) { |
5530 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5531 | } else { |
5532 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5533 | regs_user->regs = NULL; | |
4018994f JO |
5534 | } |
5535 | } | |
5536 | ||
60e2364e SE |
5537 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5538 | struct pt_regs *regs) | |
5539 | { | |
5540 | regs_intr->regs = regs; | |
5541 | regs_intr->abi = perf_reg_abi(current); | |
5542 | } | |
5543 | ||
5544 | ||
c5ebcedb JO |
5545 | /* |
5546 | * Get remaining task size from user stack pointer. | |
5547 | * | |
5548 | * It'd be better to take stack vma map and limit this more | |
5549 | * precisly, but there's no way to get it safely under interrupt, | |
5550 | * so using TASK_SIZE as limit. | |
5551 | */ | |
5552 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5553 | { | |
5554 | unsigned long addr = perf_user_stack_pointer(regs); | |
5555 | ||
5556 | if (!addr || addr >= TASK_SIZE) | |
5557 | return 0; | |
5558 | ||
5559 | return TASK_SIZE - addr; | |
5560 | } | |
5561 | ||
5562 | static u16 | |
5563 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5564 | struct pt_regs *regs) | |
5565 | { | |
5566 | u64 task_size; | |
5567 | ||
5568 | /* No regs, no stack pointer, no dump. */ | |
5569 | if (!regs) | |
5570 | return 0; | |
5571 | ||
5572 | /* | |
5573 | * Check if we fit in with the requested stack size into the: | |
5574 | * - TASK_SIZE | |
5575 | * If we don't, we limit the size to the TASK_SIZE. | |
5576 | * | |
5577 | * - remaining sample size | |
5578 | * If we don't, we customize the stack size to | |
5579 | * fit in to the remaining sample size. | |
5580 | */ | |
5581 | ||
5582 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5583 | stack_size = min(stack_size, (u16) task_size); | |
5584 | ||
5585 | /* Current header size plus static size and dynamic size. */ | |
5586 | header_size += 2 * sizeof(u64); | |
5587 | ||
5588 | /* Do we fit in with the current stack dump size? */ | |
5589 | if ((u16) (header_size + stack_size) < header_size) { | |
5590 | /* | |
5591 | * If we overflow the maximum size for the sample, | |
5592 | * we customize the stack dump size to fit in. | |
5593 | */ | |
5594 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5595 | stack_size = round_up(stack_size, sizeof(u64)); | |
5596 | } | |
5597 | ||
5598 | return stack_size; | |
5599 | } | |
5600 | ||
5601 | static void | |
5602 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5603 | struct pt_regs *regs) | |
5604 | { | |
5605 | /* Case of a kernel thread, nothing to dump */ | |
5606 | if (!regs) { | |
5607 | u64 size = 0; | |
5608 | perf_output_put(handle, size); | |
5609 | } else { | |
5610 | unsigned long sp; | |
5611 | unsigned int rem; | |
5612 | u64 dyn_size; | |
5613 | ||
5614 | /* | |
5615 | * We dump: | |
5616 | * static size | |
5617 | * - the size requested by user or the best one we can fit | |
5618 | * in to the sample max size | |
5619 | * data | |
5620 | * - user stack dump data | |
5621 | * dynamic size | |
5622 | * - the actual dumped size | |
5623 | */ | |
5624 | ||
5625 | /* Static size. */ | |
5626 | perf_output_put(handle, dump_size); | |
5627 | ||
5628 | /* Data. */ | |
5629 | sp = perf_user_stack_pointer(regs); | |
5630 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5631 | dyn_size = dump_size - rem; | |
5632 | ||
5633 | perf_output_skip(handle, rem); | |
5634 | ||
5635 | /* Dynamic size. */ | |
5636 | perf_output_put(handle, dyn_size); | |
5637 | } | |
5638 | } | |
5639 | ||
c980d109 ACM |
5640 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5641 | struct perf_sample_data *data, | |
5642 | struct perf_event *event) | |
6844c09d ACM |
5643 | { |
5644 | u64 sample_type = event->attr.sample_type; | |
5645 | ||
5646 | data->type = sample_type; | |
5647 | header->size += event->id_header_size; | |
5648 | ||
5649 | if (sample_type & PERF_SAMPLE_TID) { | |
5650 | /* namespace issues */ | |
5651 | data->tid_entry.pid = perf_event_pid(event, current); | |
5652 | data->tid_entry.tid = perf_event_tid(event, current); | |
5653 | } | |
5654 | ||
5655 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5656 | data->time = perf_event_clock(event); |
6844c09d | 5657 | |
ff3d527c | 5658 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5659 | data->id = primary_event_id(event); |
5660 | ||
5661 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5662 | data->stream_id = event->id; | |
5663 | ||
5664 | if (sample_type & PERF_SAMPLE_CPU) { | |
5665 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5666 | data->cpu_entry.reserved = 0; | |
5667 | } | |
5668 | } | |
5669 | ||
76369139 FW |
5670 | void perf_event_header__init_id(struct perf_event_header *header, |
5671 | struct perf_sample_data *data, | |
5672 | struct perf_event *event) | |
c980d109 ACM |
5673 | { |
5674 | if (event->attr.sample_id_all) | |
5675 | __perf_event_header__init_id(header, data, event); | |
5676 | } | |
5677 | ||
5678 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5679 | struct perf_sample_data *data) | |
5680 | { | |
5681 | u64 sample_type = data->type; | |
5682 | ||
5683 | if (sample_type & PERF_SAMPLE_TID) | |
5684 | perf_output_put(handle, data->tid_entry); | |
5685 | ||
5686 | if (sample_type & PERF_SAMPLE_TIME) | |
5687 | perf_output_put(handle, data->time); | |
5688 | ||
5689 | if (sample_type & PERF_SAMPLE_ID) | |
5690 | perf_output_put(handle, data->id); | |
5691 | ||
5692 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5693 | perf_output_put(handle, data->stream_id); | |
5694 | ||
5695 | if (sample_type & PERF_SAMPLE_CPU) | |
5696 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5697 | |
5698 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5699 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5700 | } |
5701 | ||
76369139 FW |
5702 | void perf_event__output_id_sample(struct perf_event *event, |
5703 | struct perf_output_handle *handle, | |
5704 | struct perf_sample_data *sample) | |
c980d109 ACM |
5705 | { |
5706 | if (event->attr.sample_id_all) | |
5707 | __perf_event__output_id_sample(handle, sample); | |
5708 | } | |
5709 | ||
3dab77fb | 5710 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5711 | struct perf_event *event, |
5712 | u64 enabled, u64 running) | |
3dab77fb | 5713 | { |
cdd6c482 | 5714 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5715 | u64 values[4]; |
5716 | int n = 0; | |
5717 | ||
b5e58793 | 5718 | values[n++] = perf_event_count(event); |
3dab77fb | 5719 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5720 | values[n++] = enabled + |
cdd6c482 | 5721 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5722 | } |
5723 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5724 | values[n++] = running + |
cdd6c482 | 5725 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5726 | } |
5727 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5728 | values[n++] = primary_event_id(event); |
3dab77fb | 5729 | |
76369139 | 5730 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5731 | } |
5732 | ||
3dab77fb | 5733 | static void perf_output_read_group(struct perf_output_handle *handle, |
eed01528 SE |
5734 | struct perf_event *event, |
5735 | u64 enabled, u64 running) | |
3dab77fb | 5736 | { |
cdd6c482 IM |
5737 | struct perf_event *leader = event->group_leader, *sub; |
5738 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5739 | u64 values[5]; |
5740 | int n = 0; | |
5741 | ||
5742 | values[n++] = 1 + leader->nr_siblings; | |
5743 | ||
5744 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5745 | values[n++] = enabled; |
3dab77fb PZ |
5746 | |
5747 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5748 | values[n++] = running; |
3dab77fb | 5749 | |
cdd6c482 | 5750 | if (leader != event) |
3dab77fb PZ |
5751 | leader->pmu->read(leader); |
5752 | ||
b5e58793 | 5753 | values[n++] = perf_event_count(leader); |
3dab77fb | 5754 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5755 | values[n++] = primary_event_id(leader); |
3dab77fb | 5756 | |
76369139 | 5757 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5758 | |
65abc865 | 5759 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5760 | n = 0; |
5761 | ||
6f5ab001 JO |
5762 | if ((sub != event) && |
5763 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5764 | sub->pmu->read(sub); |
5765 | ||
b5e58793 | 5766 | values[n++] = perf_event_count(sub); |
3dab77fb | 5767 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5768 | values[n++] = primary_event_id(sub); |
3dab77fb | 5769 | |
76369139 | 5770 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5771 | } |
5772 | } | |
5773 | ||
eed01528 SE |
5774 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5775 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5776 | ||
ba5213ae PZ |
5777 | /* |
5778 | * XXX PERF_SAMPLE_READ vs inherited events seems difficult. | |
5779 | * | |
5780 | * The problem is that its both hard and excessively expensive to iterate the | |
5781 | * child list, not to mention that its impossible to IPI the children running | |
5782 | * on another CPU, from interrupt/NMI context. | |
5783 | */ | |
3dab77fb | 5784 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5785 | struct perf_event *event) |
3dab77fb | 5786 | { |
e3f3541c | 5787 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5788 | u64 read_format = event->attr.read_format; |
5789 | ||
5790 | /* | |
5791 | * compute total_time_enabled, total_time_running | |
5792 | * based on snapshot values taken when the event | |
5793 | * was last scheduled in. | |
5794 | * | |
5795 | * we cannot simply called update_context_time() | |
5796 | * because of locking issue as we are called in | |
5797 | * NMI context | |
5798 | */ | |
c4794295 | 5799 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5800 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5801 | |
cdd6c482 | 5802 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5803 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5804 | else |
eed01528 | 5805 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5806 | } |
5807 | ||
5622f295 MM |
5808 | void perf_output_sample(struct perf_output_handle *handle, |
5809 | struct perf_event_header *header, | |
5810 | struct perf_sample_data *data, | |
cdd6c482 | 5811 | struct perf_event *event) |
5622f295 MM |
5812 | { |
5813 | u64 sample_type = data->type; | |
5814 | ||
5815 | perf_output_put(handle, *header); | |
5816 | ||
ff3d527c AH |
5817 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5818 | perf_output_put(handle, data->id); | |
5819 | ||
5622f295 MM |
5820 | if (sample_type & PERF_SAMPLE_IP) |
5821 | perf_output_put(handle, data->ip); | |
5822 | ||
5823 | if (sample_type & PERF_SAMPLE_TID) | |
5824 | perf_output_put(handle, data->tid_entry); | |
5825 | ||
5826 | if (sample_type & PERF_SAMPLE_TIME) | |
5827 | perf_output_put(handle, data->time); | |
5828 | ||
5829 | if (sample_type & PERF_SAMPLE_ADDR) | |
5830 | perf_output_put(handle, data->addr); | |
5831 | ||
5832 | if (sample_type & PERF_SAMPLE_ID) | |
5833 | perf_output_put(handle, data->id); | |
5834 | ||
5835 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5836 | perf_output_put(handle, data->stream_id); | |
5837 | ||
5838 | if (sample_type & PERF_SAMPLE_CPU) | |
5839 | perf_output_put(handle, data->cpu_entry); | |
5840 | ||
5841 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5842 | perf_output_put(handle, data->period); | |
5843 | ||
5844 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5845 | perf_output_read(handle, event); |
5622f295 MM |
5846 | |
5847 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5848 | if (data->callchain) { | |
5849 | int size = 1; | |
5850 | ||
5851 | if (data->callchain) | |
5852 | size += data->callchain->nr; | |
5853 | ||
5854 | size *= sizeof(u64); | |
5855 | ||
76369139 | 5856 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5857 | } else { |
5858 | u64 nr = 0; | |
5859 | perf_output_put(handle, nr); | |
5860 | } | |
5861 | } | |
5862 | ||
5863 | if (sample_type & PERF_SAMPLE_RAW) { | |
7e3f977e DB |
5864 | struct perf_raw_record *raw = data->raw; |
5865 | ||
5866 | if (raw) { | |
5867 | struct perf_raw_frag *frag = &raw->frag; | |
5868 | ||
5869 | perf_output_put(handle, raw->size); | |
5870 | do { | |
5871 | if (frag->copy) { | |
5872 | __output_custom(handle, frag->copy, | |
5873 | frag->data, frag->size); | |
5874 | } else { | |
5875 | __output_copy(handle, frag->data, | |
5876 | frag->size); | |
5877 | } | |
5878 | if (perf_raw_frag_last(frag)) | |
5879 | break; | |
5880 | frag = frag->next; | |
5881 | } while (1); | |
5882 | if (frag->pad) | |
5883 | __output_skip(handle, NULL, frag->pad); | |
5622f295 MM |
5884 | } else { |
5885 | struct { | |
5886 | u32 size; | |
5887 | u32 data; | |
5888 | } raw = { | |
5889 | .size = sizeof(u32), | |
5890 | .data = 0, | |
5891 | }; | |
5892 | perf_output_put(handle, raw); | |
5893 | } | |
5894 | } | |
a7ac67ea | 5895 | |
bce38cd5 SE |
5896 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5897 | if (data->br_stack) { | |
5898 | size_t size; | |
5899 | ||
5900 | size = data->br_stack->nr | |
5901 | * sizeof(struct perf_branch_entry); | |
5902 | ||
5903 | perf_output_put(handle, data->br_stack->nr); | |
5904 | perf_output_copy(handle, data->br_stack->entries, size); | |
5905 | } else { | |
5906 | /* | |
5907 | * we always store at least the value of nr | |
5908 | */ | |
5909 | u64 nr = 0; | |
5910 | perf_output_put(handle, nr); | |
5911 | } | |
5912 | } | |
4018994f JO |
5913 | |
5914 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5915 | u64 abi = data->regs_user.abi; | |
5916 | ||
5917 | /* | |
5918 | * If there are no regs to dump, notice it through | |
5919 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5920 | */ | |
5921 | perf_output_put(handle, abi); | |
5922 | ||
5923 | if (abi) { | |
5924 | u64 mask = event->attr.sample_regs_user; | |
5925 | perf_output_sample_regs(handle, | |
5926 | data->regs_user.regs, | |
5927 | mask); | |
5928 | } | |
5929 | } | |
c5ebcedb | 5930 | |
a5cdd40c | 5931 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5932 | perf_output_sample_ustack(handle, |
5933 | data->stack_user_size, | |
5934 | data->regs_user.regs); | |
a5cdd40c | 5935 | } |
c3feedf2 AK |
5936 | |
5937 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5938 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5939 | |
5940 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5941 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5942 | |
fdfbbd07 AK |
5943 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5944 | perf_output_put(handle, data->txn); | |
5945 | ||
60e2364e SE |
5946 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5947 | u64 abi = data->regs_intr.abi; | |
5948 | /* | |
5949 | * If there are no regs to dump, notice it through | |
5950 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5951 | */ | |
5952 | perf_output_put(handle, abi); | |
5953 | ||
5954 | if (abi) { | |
5955 | u64 mask = event->attr.sample_regs_intr; | |
5956 | ||
5957 | perf_output_sample_regs(handle, | |
5958 | data->regs_intr.regs, | |
5959 | mask); | |
5960 | } | |
5961 | } | |
5962 | ||
a5cdd40c PZ |
5963 | if (!event->attr.watermark) { |
5964 | int wakeup_events = event->attr.wakeup_events; | |
5965 | ||
5966 | if (wakeup_events) { | |
5967 | struct ring_buffer *rb = handle->rb; | |
5968 | int events = local_inc_return(&rb->events); | |
5969 | ||
5970 | if (events >= wakeup_events) { | |
5971 | local_sub(wakeup_events, &rb->events); | |
5972 | local_inc(&rb->wakeup); | |
5973 | } | |
5974 | } | |
5975 | } | |
5622f295 MM |
5976 | } |
5977 | ||
5978 | void perf_prepare_sample(struct perf_event_header *header, | |
5979 | struct perf_sample_data *data, | |
cdd6c482 | 5980 | struct perf_event *event, |
5622f295 | 5981 | struct pt_regs *regs) |
7b732a75 | 5982 | { |
cdd6c482 | 5983 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5984 | |
cdd6c482 | 5985 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5986 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5987 | |
5988 | header->misc = 0; | |
5989 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5990 | |
c980d109 | 5991 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5992 | |
c320c7b7 | 5993 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5994 | data->ip = perf_instruction_pointer(regs); |
5995 | ||
b23f3325 | 5996 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5997 | int size = 1; |
394ee076 | 5998 | |
e6dab5ff | 5999 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
6000 | |
6001 | if (data->callchain) | |
6002 | size += data->callchain->nr; | |
6003 | ||
6004 | header->size += size * sizeof(u64); | |
394ee076 PZ |
6005 | } |
6006 | ||
3a43ce68 | 6007 | if (sample_type & PERF_SAMPLE_RAW) { |
7e3f977e DB |
6008 | struct perf_raw_record *raw = data->raw; |
6009 | int size; | |
6010 | ||
6011 | if (raw) { | |
6012 | struct perf_raw_frag *frag = &raw->frag; | |
6013 | u32 sum = 0; | |
6014 | ||
6015 | do { | |
6016 | sum += frag->size; | |
6017 | if (perf_raw_frag_last(frag)) | |
6018 | break; | |
6019 | frag = frag->next; | |
6020 | } while (1); | |
6021 | ||
6022 | size = round_up(sum + sizeof(u32), sizeof(u64)); | |
6023 | raw->size = size - sizeof(u32); | |
6024 | frag->pad = raw->size - sum; | |
6025 | } else { | |
6026 | size = sizeof(u64); | |
6027 | } | |
a044560c | 6028 | |
7e3f977e | 6029 | header->size += size; |
7f453c24 | 6030 | } |
bce38cd5 SE |
6031 | |
6032 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
6033 | int size = sizeof(u64); /* nr */ | |
6034 | if (data->br_stack) { | |
6035 | size += data->br_stack->nr | |
6036 | * sizeof(struct perf_branch_entry); | |
6037 | } | |
6038 | header->size += size; | |
6039 | } | |
4018994f | 6040 | |
2565711f | 6041 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
6042 | perf_sample_regs_user(&data->regs_user, regs, |
6043 | &data->regs_user_copy); | |
2565711f | 6044 | |
4018994f JO |
6045 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
6046 | /* regs dump ABI info */ | |
6047 | int size = sizeof(u64); | |
6048 | ||
4018994f JO |
6049 | if (data->regs_user.regs) { |
6050 | u64 mask = event->attr.sample_regs_user; | |
6051 | size += hweight64(mask) * sizeof(u64); | |
6052 | } | |
6053 | ||
6054 | header->size += size; | |
6055 | } | |
c5ebcedb JO |
6056 | |
6057 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
6058 | /* | |
6059 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
6060 | * processed as the last one or have additional check added | |
6061 | * in case new sample type is added, because we could eat | |
6062 | * up the rest of the sample size. | |
6063 | */ | |
c5ebcedb JO |
6064 | u16 stack_size = event->attr.sample_stack_user; |
6065 | u16 size = sizeof(u64); | |
6066 | ||
c5ebcedb | 6067 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 6068 | data->regs_user.regs); |
c5ebcedb JO |
6069 | |
6070 | /* | |
6071 | * If there is something to dump, add space for the dump | |
6072 | * itself and for the field that tells the dynamic size, | |
6073 | * which is how many have been actually dumped. | |
6074 | */ | |
6075 | if (stack_size) | |
6076 | size += sizeof(u64) + stack_size; | |
6077 | ||
6078 | data->stack_user_size = stack_size; | |
6079 | header->size += size; | |
6080 | } | |
60e2364e SE |
6081 | |
6082 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
6083 | /* regs dump ABI info */ | |
6084 | int size = sizeof(u64); | |
6085 | ||
6086 | perf_sample_regs_intr(&data->regs_intr, regs); | |
6087 | ||
6088 | if (data->regs_intr.regs) { | |
6089 | u64 mask = event->attr.sample_regs_intr; | |
6090 | ||
6091 | size += hweight64(mask) * sizeof(u64); | |
6092 | } | |
6093 | ||
6094 | header->size += size; | |
6095 | } | |
5622f295 | 6096 | } |
7f453c24 | 6097 | |
9ecda41a WN |
6098 | static void __always_inline |
6099 | __perf_event_output(struct perf_event *event, | |
6100 | struct perf_sample_data *data, | |
6101 | struct pt_regs *regs, | |
6102 | int (*output_begin)(struct perf_output_handle *, | |
6103 | struct perf_event *, | |
6104 | unsigned int)) | |
5622f295 MM |
6105 | { |
6106 | struct perf_output_handle handle; | |
6107 | struct perf_event_header header; | |
689802b2 | 6108 | |
927c7a9e FW |
6109 | /* protect the callchain buffers */ |
6110 | rcu_read_lock(); | |
6111 | ||
cdd6c482 | 6112 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 6113 | |
9ecda41a | 6114 | if (output_begin(&handle, event, header.size)) |
927c7a9e | 6115 | goto exit; |
0322cd6e | 6116 | |
cdd6c482 | 6117 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 6118 | |
8a057d84 | 6119 | perf_output_end(&handle); |
927c7a9e FW |
6120 | |
6121 | exit: | |
6122 | rcu_read_unlock(); | |
0322cd6e PZ |
6123 | } |
6124 | ||
9ecda41a WN |
6125 | void |
6126 | perf_event_output_forward(struct perf_event *event, | |
6127 | struct perf_sample_data *data, | |
6128 | struct pt_regs *regs) | |
6129 | { | |
6130 | __perf_event_output(event, data, regs, perf_output_begin_forward); | |
6131 | } | |
6132 | ||
6133 | void | |
6134 | perf_event_output_backward(struct perf_event *event, | |
6135 | struct perf_sample_data *data, | |
6136 | struct pt_regs *regs) | |
6137 | { | |
6138 | __perf_event_output(event, data, regs, perf_output_begin_backward); | |
6139 | } | |
6140 | ||
6141 | void | |
6142 | perf_event_output(struct perf_event *event, | |
6143 | struct perf_sample_data *data, | |
6144 | struct pt_regs *regs) | |
6145 | { | |
6146 | __perf_event_output(event, data, regs, perf_output_begin); | |
6147 | } | |
6148 | ||
38b200d6 | 6149 | /* |
cdd6c482 | 6150 | * read event_id |
38b200d6 PZ |
6151 | */ |
6152 | ||
6153 | struct perf_read_event { | |
6154 | struct perf_event_header header; | |
6155 | ||
6156 | u32 pid; | |
6157 | u32 tid; | |
38b200d6 PZ |
6158 | }; |
6159 | ||
6160 | static void | |
cdd6c482 | 6161 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
6162 | struct task_struct *task) |
6163 | { | |
6164 | struct perf_output_handle handle; | |
c980d109 | 6165 | struct perf_sample_data sample; |
dfc65094 | 6166 | struct perf_read_event read_event = { |
38b200d6 | 6167 | .header = { |
cdd6c482 | 6168 | .type = PERF_RECORD_READ, |
38b200d6 | 6169 | .misc = 0, |
c320c7b7 | 6170 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 6171 | }, |
cdd6c482 IM |
6172 | .pid = perf_event_pid(event, task), |
6173 | .tid = perf_event_tid(event, task), | |
38b200d6 | 6174 | }; |
3dab77fb | 6175 | int ret; |
38b200d6 | 6176 | |
c980d109 | 6177 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 6178 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
6179 | if (ret) |
6180 | return; | |
6181 | ||
dfc65094 | 6182 | perf_output_put(&handle, read_event); |
cdd6c482 | 6183 | perf_output_read(&handle, event); |
c980d109 | 6184 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 6185 | |
38b200d6 PZ |
6186 | perf_output_end(&handle); |
6187 | } | |
6188 | ||
aab5b71e | 6189 | typedef void (perf_iterate_f)(struct perf_event *event, void *data); |
52d857a8 JO |
6190 | |
6191 | static void | |
aab5b71e PZ |
6192 | perf_iterate_ctx(struct perf_event_context *ctx, |
6193 | perf_iterate_f output, | |
b73e4fef | 6194 | void *data, bool all) |
52d857a8 JO |
6195 | { |
6196 | struct perf_event *event; | |
6197 | ||
6198 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
b73e4fef AS |
6199 | if (!all) { |
6200 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
6201 | continue; | |
6202 | if (!event_filter_match(event)) | |
6203 | continue; | |
6204 | } | |
6205 | ||
67516844 | 6206 | output(event, data); |
52d857a8 JO |
6207 | } |
6208 | } | |
6209 | ||
aab5b71e | 6210 | static void perf_iterate_sb_cpu(perf_iterate_f output, void *data) |
f2fb6bef KL |
6211 | { |
6212 | struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events); | |
6213 | struct perf_event *event; | |
6214 | ||
6215 | list_for_each_entry_rcu(event, &pel->list, sb_list) { | |
0b8f1e2e PZ |
6216 | /* |
6217 | * Skip events that are not fully formed yet; ensure that | |
6218 | * if we observe event->ctx, both event and ctx will be | |
6219 | * complete enough. See perf_install_in_context(). | |
6220 | */ | |
6221 | if (!smp_load_acquire(&event->ctx)) | |
6222 | continue; | |
6223 | ||
f2fb6bef KL |
6224 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
6225 | continue; | |
6226 | if (!event_filter_match(event)) | |
6227 | continue; | |
6228 | output(event, data); | |
6229 | } | |
6230 | } | |
6231 | ||
aab5b71e PZ |
6232 | /* |
6233 | * Iterate all events that need to receive side-band events. | |
6234 | * | |
6235 | * For new callers; ensure that account_pmu_sb_event() includes | |
6236 | * your event, otherwise it might not get delivered. | |
6237 | */ | |
52d857a8 | 6238 | static void |
aab5b71e | 6239 | perf_iterate_sb(perf_iterate_f output, void *data, |
52d857a8 JO |
6240 | struct perf_event_context *task_ctx) |
6241 | { | |
52d857a8 | 6242 | struct perf_event_context *ctx; |
52d857a8 JO |
6243 | int ctxn; |
6244 | ||
aab5b71e PZ |
6245 | rcu_read_lock(); |
6246 | preempt_disable(); | |
6247 | ||
4e93ad60 | 6248 | /* |
aab5b71e PZ |
6249 | * If we have task_ctx != NULL we only notify the task context itself. |
6250 | * The task_ctx is set only for EXIT events before releasing task | |
4e93ad60 JO |
6251 | * context. |
6252 | */ | |
6253 | if (task_ctx) { | |
aab5b71e PZ |
6254 | perf_iterate_ctx(task_ctx, output, data, false); |
6255 | goto done; | |
4e93ad60 JO |
6256 | } |
6257 | ||
aab5b71e | 6258 | perf_iterate_sb_cpu(output, data); |
f2fb6bef KL |
6259 | |
6260 | for_each_task_context_nr(ctxn) { | |
52d857a8 JO |
6261 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); |
6262 | if (ctx) | |
aab5b71e | 6263 | perf_iterate_ctx(ctx, output, data, false); |
52d857a8 | 6264 | } |
aab5b71e | 6265 | done: |
f2fb6bef | 6266 | preempt_enable(); |
52d857a8 | 6267 | rcu_read_unlock(); |
95ff4ca2 AS |
6268 | } |
6269 | ||
375637bc AS |
6270 | /* |
6271 | * Clear all file-based filters at exec, they'll have to be | |
6272 | * re-instated when/if these objects are mmapped again. | |
6273 | */ | |
6274 | static void perf_event_addr_filters_exec(struct perf_event *event, void *data) | |
6275 | { | |
6276 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
6277 | struct perf_addr_filter *filter; | |
6278 | unsigned int restart = 0, count = 0; | |
6279 | unsigned long flags; | |
6280 | ||
6281 | if (!has_addr_filter(event)) | |
6282 | return; | |
6283 | ||
6284 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
6285 | list_for_each_entry(filter, &ifh->list, entry) { | |
6286 | if (filter->inode) { | |
6287 | event->addr_filters_offs[count] = 0; | |
6288 | restart++; | |
6289 | } | |
6290 | ||
6291 | count++; | |
6292 | } | |
6293 | ||
6294 | if (restart) | |
6295 | event->addr_filters_gen++; | |
6296 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
6297 | ||
6298 | if (restart) | |
767ae086 | 6299 | perf_event_stop(event, 1); |
375637bc AS |
6300 | } |
6301 | ||
6302 | void perf_event_exec(void) | |
6303 | { | |
6304 | struct perf_event_context *ctx; | |
6305 | int ctxn; | |
6306 | ||
6307 | rcu_read_lock(); | |
6308 | for_each_task_context_nr(ctxn) { | |
6309 | ctx = current->perf_event_ctxp[ctxn]; | |
6310 | if (!ctx) | |
6311 | continue; | |
6312 | ||
6313 | perf_event_enable_on_exec(ctxn); | |
6314 | ||
aab5b71e | 6315 | perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, |
375637bc AS |
6316 | true); |
6317 | } | |
6318 | rcu_read_unlock(); | |
6319 | } | |
6320 | ||
95ff4ca2 AS |
6321 | struct remote_output { |
6322 | struct ring_buffer *rb; | |
6323 | int err; | |
6324 | }; | |
6325 | ||
6326 | static void __perf_event_output_stop(struct perf_event *event, void *data) | |
6327 | { | |
6328 | struct perf_event *parent = event->parent; | |
6329 | struct remote_output *ro = data; | |
6330 | struct ring_buffer *rb = ro->rb; | |
375637bc AS |
6331 | struct stop_event_data sd = { |
6332 | .event = event, | |
6333 | }; | |
95ff4ca2 AS |
6334 | |
6335 | if (!has_aux(event)) | |
6336 | return; | |
6337 | ||
6338 | if (!parent) | |
6339 | parent = event; | |
6340 | ||
6341 | /* | |
6342 | * In case of inheritance, it will be the parent that links to the | |
767ae086 AS |
6343 | * ring-buffer, but it will be the child that's actually using it. |
6344 | * | |
6345 | * We are using event::rb to determine if the event should be stopped, | |
6346 | * however this may race with ring_buffer_attach() (through set_output), | |
6347 | * which will make us skip the event that actually needs to be stopped. | |
6348 | * So ring_buffer_attach() has to stop an aux event before re-assigning | |
6349 | * its rb pointer. | |
95ff4ca2 AS |
6350 | */ |
6351 | if (rcu_dereference(parent->rb) == rb) | |
375637bc | 6352 | ro->err = __perf_event_stop(&sd); |
95ff4ca2 AS |
6353 | } |
6354 | ||
6355 | static int __perf_pmu_output_stop(void *info) | |
6356 | { | |
6357 | struct perf_event *event = info; | |
6358 | struct pmu *pmu = event->pmu; | |
8b6a3fe8 | 6359 | struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95ff4ca2 AS |
6360 | struct remote_output ro = { |
6361 | .rb = event->rb, | |
6362 | }; | |
6363 | ||
6364 | rcu_read_lock(); | |
aab5b71e | 6365 | perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false); |
95ff4ca2 | 6366 | if (cpuctx->task_ctx) |
aab5b71e | 6367 | perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop, |
b73e4fef | 6368 | &ro, false); |
95ff4ca2 AS |
6369 | rcu_read_unlock(); |
6370 | ||
6371 | return ro.err; | |
6372 | } | |
6373 | ||
6374 | static void perf_pmu_output_stop(struct perf_event *event) | |
6375 | { | |
6376 | struct perf_event *iter; | |
6377 | int err, cpu; | |
6378 | ||
6379 | restart: | |
6380 | rcu_read_lock(); | |
6381 | list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { | |
6382 | /* | |
6383 | * For per-CPU events, we need to make sure that neither they | |
6384 | * nor their children are running; for cpu==-1 events it's | |
6385 | * sufficient to stop the event itself if it's active, since | |
6386 | * it can't have children. | |
6387 | */ | |
6388 | cpu = iter->cpu; | |
6389 | if (cpu == -1) | |
6390 | cpu = READ_ONCE(iter->oncpu); | |
6391 | ||
6392 | if (cpu == -1) | |
6393 | continue; | |
6394 | ||
6395 | err = cpu_function_call(cpu, __perf_pmu_output_stop, event); | |
6396 | if (err == -EAGAIN) { | |
6397 | rcu_read_unlock(); | |
6398 | goto restart; | |
6399 | } | |
6400 | } | |
6401 | rcu_read_unlock(); | |
52d857a8 JO |
6402 | } |
6403 | ||
60313ebe | 6404 | /* |
9f498cc5 PZ |
6405 | * task tracking -- fork/exit |
6406 | * | |
13d7a241 | 6407 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
6408 | */ |
6409 | ||
9f498cc5 | 6410 | struct perf_task_event { |
3a80b4a3 | 6411 | struct task_struct *task; |
cdd6c482 | 6412 | struct perf_event_context *task_ctx; |
60313ebe PZ |
6413 | |
6414 | struct { | |
6415 | struct perf_event_header header; | |
6416 | ||
6417 | u32 pid; | |
6418 | u32 ppid; | |
9f498cc5 PZ |
6419 | u32 tid; |
6420 | u32 ptid; | |
393b2ad8 | 6421 | u64 time; |
cdd6c482 | 6422 | } event_id; |
60313ebe PZ |
6423 | }; |
6424 | ||
67516844 JO |
6425 | static int perf_event_task_match(struct perf_event *event) |
6426 | { | |
13d7a241 SE |
6427 | return event->attr.comm || event->attr.mmap || |
6428 | event->attr.mmap2 || event->attr.mmap_data || | |
6429 | event->attr.task; | |
67516844 JO |
6430 | } |
6431 | ||
cdd6c482 | 6432 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 6433 | void *data) |
60313ebe | 6434 | { |
52d857a8 | 6435 | struct perf_task_event *task_event = data; |
60313ebe | 6436 | struct perf_output_handle handle; |
c980d109 | 6437 | struct perf_sample_data sample; |
9f498cc5 | 6438 | struct task_struct *task = task_event->task; |
c980d109 | 6439 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 6440 | |
67516844 JO |
6441 | if (!perf_event_task_match(event)) |
6442 | return; | |
6443 | ||
c980d109 | 6444 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 6445 | |
c980d109 | 6446 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 6447 | task_event->event_id.header.size); |
ef60777c | 6448 | if (ret) |
c980d109 | 6449 | goto out; |
60313ebe | 6450 | |
cdd6c482 IM |
6451 | task_event->event_id.pid = perf_event_pid(event, task); |
6452 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 6453 | |
cdd6c482 IM |
6454 | task_event->event_id.tid = perf_event_tid(event, task); |
6455 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 6456 | |
34f43927 PZ |
6457 | task_event->event_id.time = perf_event_clock(event); |
6458 | ||
cdd6c482 | 6459 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 6460 | |
c980d109 ACM |
6461 | perf_event__output_id_sample(event, &handle, &sample); |
6462 | ||
60313ebe | 6463 | perf_output_end(&handle); |
c980d109 ACM |
6464 | out: |
6465 | task_event->event_id.header.size = size; | |
60313ebe PZ |
6466 | } |
6467 | ||
cdd6c482 IM |
6468 | static void perf_event_task(struct task_struct *task, |
6469 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 6470 | int new) |
60313ebe | 6471 | { |
9f498cc5 | 6472 | struct perf_task_event task_event; |
60313ebe | 6473 | |
cdd6c482 IM |
6474 | if (!atomic_read(&nr_comm_events) && |
6475 | !atomic_read(&nr_mmap_events) && | |
6476 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
6477 | return; |
6478 | ||
9f498cc5 | 6479 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
6480 | .task = task, |
6481 | .task_ctx = task_ctx, | |
cdd6c482 | 6482 | .event_id = { |
60313ebe | 6483 | .header = { |
cdd6c482 | 6484 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 6485 | .misc = 0, |
cdd6c482 | 6486 | .size = sizeof(task_event.event_id), |
60313ebe | 6487 | }, |
573402db PZ |
6488 | /* .pid */ |
6489 | /* .ppid */ | |
9f498cc5 PZ |
6490 | /* .tid */ |
6491 | /* .ptid */ | |
34f43927 | 6492 | /* .time */ |
60313ebe PZ |
6493 | }, |
6494 | }; | |
6495 | ||
aab5b71e | 6496 | perf_iterate_sb(perf_event_task_output, |
52d857a8 JO |
6497 | &task_event, |
6498 | task_ctx); | |
9f498cc5 PZ |
6499 | } |
6500 | ||
cdd6c482 | 6501 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 6502 | { |
cdd6c482 | 6503 | perf_event_task(task, NULL, 1); |
e4222673 | 6504 | perf_event_namespaces(task); |
60313ebe PZ |
6505 | } |
6506 | ||
8d1b2d93 PZ |
6507 | /* |
6508 | * comm tracking | |
6509 | */ | |
6510 | ||
6511 | struct perf_comm_event { | |
22a4f650 IM |
6512 | struct task_struct *task; |
6513 | char *comm; | |
8d1b2d93 PZ |
6514 | int comm_size; |
6515 | ||
6516 | struct { | |
6517 | struct perf_event_header header; | |
6518 | ||
6519 | u32 pid; | |
6520 | u32 tid; | |
cdd6c482 | 6521 | } event_id; |
8d1b2d93 PZ |
6522 | }; |
6523 | ||
67516844 JO |
6524 | static int perf_event_comm_match(struct perf_event *event) |
6525 | { | |
6526 | return event->attr.comm; | |
6527 | } | |
6528 | ||
cdd6c482 | 6529 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 6530 | void *data) |
8d1b2d93 | 6531 | { |
52d857a8 | 6532 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 6533 | struct perf_output_handle handle; |
c980d109 | 6534 | struct perf_sample_data sample; |
cdd6c482 | 6535 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
6536 | int ret; |
6537 | ||
67516844 JO |
6538 | if (!perf_event_comm_match(event)) |
6539 | return; | |
6540 | ||
c980d109 ACM |
6541 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
6542 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6543 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
6544 | |
6545 | if (ret) | |
c980d109 | 6546 | goto out; |
8d1b2d93 | 6547 | |
cdd6c482 IM |
6548 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
6549 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 6550 | |
cdd6c482 | 6551 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 6552 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 6553 | comm_event->comm_size); |
c980d109 ACM |
6554 | |
6555 | perf_event__output_id_sample(event, &handle, &sample); | |
6556 | ||
8d1b2d93 | 6557 | perf_output_end(&handle); |
c980d109 ACM |
6558 | out: |
6559 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
6560 | } |
6561 | ||
cdd6c482 | 6562 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 6563 | { |
413ee3b4 | 6564 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 6565 | unsigned int size; |
8d1b2d93 | 6566 | |
413ee3b4 | 6567 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 6568 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 6569 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
6570 | |
6571 | comm_event->comm = comm; | |
6572 | comm_event->comm_size = size; | |
6573 | ||
cdd6c482 | 6574 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 6575 | |
aab5b71e | 6576 | perf_iterate_sb(perf_event_comm_output, |
52d857a8 JO |
6577 | comm_event, |
6578 | NULL); | |
8d1b2d93 PZ |
6579 | } |
6580 | ||
82b89778 | 6581 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 6582 | { |
9ee318a7 PZ |
6583 | struct perf_comm_event comm_event; |
6584 | ||
cdd6c482 | 6585 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 6586 | return; |
a63eaf34 | 6587 | |
9ee318a7 | 6588 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 6589 | .task = task, |
573402db PZ |
6590 | /* .comm */ |
6591 | /* .comm_size */ | |
cdd6c482 | 6592 | .event_id = { |
573402db | 6593 | .header = { |
cdd6c482 | 6594 | .type = PERF_RECORD_COMM, |
82b89778 | 6595 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
6596 | /* .size */ |
6597 | }, | |
6598 | /* .pid */ | |
6599 | /* .tid */ | |
8d1b2d93 PZ |
6600 | }, |
6601 | }; | |
6602 | ||
cdd6c482 | 6603 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
6604 | } |
6605 | ||
e4222673 HB |
6606 | /* |
6607 | * namespaces tracking | |
6608 | */ | |
6609 | ||
6610 | struct perf_namespaces_event { | |
6611 | struct task_struct *task; | |
6612 | ||
6613 | struct { | |
6614 | struct perf_event_header header; | |
6615 | ||
6616 | u32 pid; | |
6617 | u32 tid; | |
6618 | u64 nr_namespaces; | |
6619 | struct perf_ns_link_info link_info[NR_NAMESPACES]; | |
6620 | } event_id; | |
6621 | }; | |
6622 | ||
6623 | static int perf_event_namespaces_match(struct perf_event *event) | |
6624 | { | |
6625 | return event->attr.namespaces; | |
6626 | } | |
6627 | ||
6628 | static void perf_event_namespaces_output(struct perf_event *event, | |
6629 | void *data) | |
6630 | { | |
6631 | struct perf_namespaces_event *namespaces_event = data; | |
6632 | struct perf_output_handle handle; | |
6633 | struct perf_sample_data sample; | |
6634 | int ret; | |
6635 | ||
6636 | if (!perf_event_namespaces_match(event)) | |
6637 | return; | |
6638 | ||
6639 | perf_event_header__init_id(&namespaces_event->event_id.header, | |
6640 | &sample, event); | |
6641 | ret = perf_output_begin(&handle, event, | |
6642 | namespaces_event->event_id.header.size); | |
6643 | if (ret) | |
6644 | return; | |
6645 | ||
6646 | namespaces_event->event_id.pid = perf_event_pid(event, | |
6647 | namespaces_event->task); | |
6648 | namespaces_event->event_id.tid = perf_event_tid(event, | |
6649 | namespaces_event->task); | |
6650 | ||
6651 | perf_output_put(&handle, namespaces_event->event_id); | |
6652 | ||
6653 | perf_event__output_id_sample(event, &handle, &sample); | |
6654 | ||
6655 | perf_output_end(&handle); | |
6656 | } | |
6657 | ||
6658 | static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, | |
6659 | struct task_struct *task, | |
6660 | const struct proc_ns_operations *ns_ops) | |
6661 | { | |
6662 | struct path ns_path; | |
6663 | struct inode *ns_inode; | |
6664 | void *error; | |
6665 | ||
6666 | error = ns_get_path(&ns_path, task, ns_ops); | |
6667 | if (!error) { | |
6668 | ns_inode = ns_path.dentry->d_inode; | |
6669 | ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev); | |
6670 | ns_link_info->ino = ns_inode->i_ino; | |
6671 | } | |
6672 | } | |
6673 | ||
6674 | void perf_event_namespaces(struct task_struct *task) | |
6675 | { | |
6676 | struct perf_namespaces_event namespaces_event; | |
6677 | struct perf_ns_link_info *ns_link_info; | |
6678 | ||
6679 | if (!atomic_read(&nr_namespaces_events)) | |
6680 | return; | |
6681 | ||
6682 | namespaces_event = (struct perf_namespaces_event){ | |
6683 | .task = task, | |
6684 | .event_id = { | |
6685 | .header = { | |
6686 | .type = PERF_RECORD_NAMESPACES, | |
6687 | .misc = 0, | |
6688 | .size = sizeof(namespaces_event.event_id), | |
6689 | }, | |
6690 | /* .pid */ | |
6691 | /* .tid */ | |
6692 | .nr_namespaces = NR_NAMESPACES, | |
6693 | /* .link_info[NR_NAMESPACES] */ | |
6694 | }, | |
6695 | }; | |
6696 | ||
6697 | ns_link_info = namespaces_event.event_id.link_info; | |
6698 | ||
6699 | perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX], | |
6700 | task, &mntns_operations); | |
6701 | ||
6702 | #ifdef CONFIG_USER_NS | |
6703 | perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX], | |
6704 | task, &userns_operations); | |
6705 | #endif | |
6706 | #ifdef CONFIG_NET_NS | |
6707 | perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX], | |
6708 | task, &netns_operations); | |
6709 | #endif | |
6710 | #ifdef CONFIG_UTS_NS | |
6711 | perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX], | |
6712 | task, &utsns_operations); | |
6713 | #endif | |
6714 | #ifdef CONFIG_IPC_NS | |
6715 | perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX], | |
6716 | task, &ipcns_operations); | |
6717 | #endif | |
6718 | #ifdef CONFIG_PID_NS | |
6719 | perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX], | |
6720 | task, &pidns_operations); | |
6721 | #endif | |
6722 | #ifdef CONFIG_CGROUPS | |
6723 | perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX], | |
6724 | task, &cgroupns_operations); | |
6725 | #endif | |
6726 | ||
6727 | perf_iterate_sb(perf_event_namespaces_output, | |
6728 | &namespaces_event, | |
6729 | NULL); | |
6730 | } | |
6731 | ||
0a4a9391 PZ |
6732 | /* |
6733 | * mmap tracking | |
6734 | */ | |
6735 | ||
6736 | struct perf_mmap_event { | |
089dd79d PZ |
6737 | struct vm_area_struct *vma; |
6738 | ||
6739 | const char *file_name; | |
6740 | int file_size; | |
13d7a241 SE |
6741 | int maj, min; |
6742 | u64 ino; | |
6743 | u64 ino_generation; | |
f972eb63 | 6744 | u32 prot, flags; |
0a4a9391 PZ |
6745 | |
6746 | struct { | |
6747 | struct perf_event_header header; | |
6748 | ||
6749 | u32 pid; | |
6750 | u32 tid; | |
6751 | u64 start; | |
6752 | u64 len; | |
6753 | u64 pgoff; | |
cdd6c482 | 6754 | } event_id; |
0a4a9391 PZ |
6755 | }; |
6756 | ||
67516844 JO |
6757 | static int perf_event_mmap_match(struct perf_event *event, |
6758 | void *data) | |
6759 | { | |
6760 | struct perf_mmap_event *mmap_event = data; | |
6761 | struct vm_area_struct *vma = mmap_event->vma; | |
6762 | int executable = vma->vm_flags & VM_EXEC; | |
6763 | ||
6764 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 6765 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
6766 | } |
6767 | ||
cdd6c482 | 6768 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 6769 | void *data) |
0a4a9391 | 6770 | { |
52d857a8 | 6771 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 6772 | struct perf_output_handle handle; |
c980d109 | 6773 | struct perf_sample_data sample; |
cdd6c482 | 6774 | int size = mmap_event->event_id.header.size; |
c980d109 | 6775 | int ret; |
0a4a9391 | 6776 | |
67516844 JO |
6777 | if (!perf_event_mmap_match(event, data)) |
6778 | return; | |
6779 | ||
13d7a241 SE |
6780 | if (event->attr.mmap2) { |
6781 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
6782 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
6783 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
6784 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 6785 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
6786 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
6787 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
6788 | } |
6789 | ||
c980d109 ACM |
6790 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
6791 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6792 | mmap_event->event_id.header.size); |
0a4a9391 | 6793 | if (ret) |
c980d109 | 6794 | goto out; |
0a4a9391 | 6795 | |
cdd6c482 IM |
6796 | mmap_event->event_id.pid = perf_event_pid(event, current); |
6797 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 6798 | |
cdd6c482 | 6799 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
6800 | |
6801 | if (event->attr.mmap2) { | |
6802 | perf_output_put(&handle, mmap_event->maj); | |
6803 | perf_output_put(&handle, mmap_event->min); | |
6804 | perf_output_put(&handle, mmap_event->ino); | |
6805 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
6806 | perf_output_put(&handle, mmap_event->prot); |
6807 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
6808 | } |
6809 | ||
76369139 | 6810 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 6811 | mmap_event->file_size); |
c980d109 ACM |
6812 | |
6813 | perf_event__output_id_sample(event, &handle, &sample); | |
6814 | ||
78d613eb | 6815 | perf_output_end(&handle); |
c980d109 ACM |
6816 | out: |
6817 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
6818 | } |
6819 | ||
cdd6c482 | 6820 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 6821 | { |
089dd79d PZ |
6822 | struct vm_area_struct *vma = mmap_event->vma; |
6823 | struct file *file = vma->vm_file; | |
13d7a241 SE |
6824 | int maj = 0, min = 0; |
6825 | u64 ino = 0, gen = 0; | |
f972eb63 | 6826 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
6827 | unsigned int size; |
6828 | char tmp[16]; | |
6829 | char *buf = NULL; | |
2c42cfbf | 6830 | char *name; |
413ee3b4 | 6831 | |
0b3589be PZ |
6832 | if (vma->vm_flags & VM_READ) |
6833 | prot |= PROT_READ; | |
6834 | if (vma->vm_flags & VM_WRITE) | |
6835 | prot |= PROT_WRITE; | |
6836 | if (vma->vm_flags & VM_EXEC) | |
6837 | prot |= PROT_EXEC; | |
6838 | ||
6839 | if (vma->vm_flags & VM_MAYSHARE) | |
6840 | flags = MAP_SHARED; | |
6841 | else | |
6842 | flags = MAP_PRIVATE; | |
6843 | ||
6844 | if (vma->vm_flags & VM_DENYWRITE) | |
6845 | flags |= MAP_DENYWRITE; | |
6846 | if (vma->vm_flags & VM_MAYEXEC) | |
6847 | flags |= MAP_EXECUTABLE; | |
6848 | if (vma->vm_flags & VM_LOCKED) | |
6849 | flags |= MAP_LOCKED; | |
6850 | if (vma->vm_flags & VM_HUGETLB) | |
6851 | flags |= MAP_HUGETLB; | |
6852 | ||
0a4a9391 | 6853 | if (file) { |
13d7a241 SE |
6854 | struct inode *inode; |
6855 | dev_t dev; | |
3ea2f2b9 | 6856 | |
2c42cfbf | 6857 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 6858 | if (!buf) { |
c7e548b4 ON |
6859 | name = "//enomem"; |
6860 | goto cpy_name; | |
0a4a9391 | 6861 | } |
413ee3b4 | 6862 | /* |
3ea2f2b9 | 6863 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
6864 | * need to add enough zero bytes after the string to handle |
6865 | * the 64bit alignment we do later. | |
6866 | */ | |
9bf39ab2 | 6867 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 6868 | if (IS_ERR(name)) { |
c7e548b4 ON |
6869 | name = "//toolong"; |
6870 | goto cpy_name; | |
0a4a9391 | 6871 | } |
13d7a241 SE |
6872 | inode = file_inode(vma->vm_file); |
6873 | dev = inode->i_sb->s_dev; | |
6874 | ino = inode->i_ino; | |
6875 | gen = inode->i_generation; | |
6876 | maj = MAJOR(dev); | |
6877 | min = MINOR(dev); | |
f972eb63 | 6878 | |
c7e548b4 | 6879 | goto got_name; |
0a4a9391 | 6880 | } else { |
fbe26abe JO |
6881 | if (vma->vm_ops && vma->vm_ops->name) { |
6882 | name = (char *) vma->vm_ops->name(vma); | |
6883 | if (name) | |
6884 | goto cpy_name; | |
6885 | } | |
6886 | ||
2c42cfbf | 6887 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6888 | if (name) |
6889 | goto cpy_name; | |
089dd79d | 6890 | |
32c5fb7e | 6891 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6892 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6893 | name = "[heap]"; |
6894 | goto cpy_name; | |
32c5fb7e ON |
6895 | } |
6896 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6897 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6898 | name = "[stack]"; |
6899 | goto cpy_name; | |
089dd79d PZ |
6900 | } |
6901 | ||
c7e548b4 ON |
6902 | name = "//anon"; |
6903 | goto cpy_name; | |
0a4a9391 PZ |
6904 | } |
6905 | ||
c7e548b4 ON |
6906 | cpy_name: |
6907 | strlcpy(tmp, name, sizeof(tmp)); | |
6908 | name = tmp; | |
0a4a9391 | 6909 | got_name: |
2c42cfbf PZ |
6910 | /* |
6911 | * Since our buffer works in 8 byte units we need to align our string | |
6912 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6913 | * zero'd out to avoid leaking random bits to userspace. | |
6914 | */ | |
6915 | size = strlen(name)+1; | |
6916 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6917 | name[size++] = '\0'; | |
0a4a9391 PZ |
6918 | |
6919 | mmap_event->file_name = name; | |
6920 | mmap_event->file_size = size; | |
13d7a241 SE |
6921 | mmap_event->maj = maj; |
6922 | mmap_event->min = min; | |
6923 | mmap_event->ino = ino; | |
6924 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6925 | mmap_event->prot = prot; |
6926 | mmap_event->flags = flags; | |
0a4a9391 | 6927 | |
2fe85427 SE |
6928 | if (!(vma->vm_flags & VM_EXEC)) |
6929 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6930 | ||
cdd6c482 | 6931 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6932 | |
aab5b71e | 6933 | perf_iterate_sb(perf_event_mmap_output, |
52d857a8 JO |
6934 | mmap_event, |
6935 | NULL); | |
665c2142 | 6936 | |
0a4a9391 PZ |
6937 | kfree(buf); |
6938 | } | |
6939 | ||
375637bc AS |
6940 | /* |
6941 | * Check whether inode and address range match filter criteria. | |
6942 | */ | |
6943 | static bool perf_addr_filter_match(struct perf_addr_filter *filter, | |
6944 | struct file *file, unsigned long offset, | |
6945 | unsigned long size) | |
6946 | { | |
45063097 | 6947 | if (filter->inode != file_inode(file)) |
375637bc AS |
6948 | return false; |
6949 | ||
6950 | if (filter->offset > offset + size) | |
6951 | return false; | |
6952 | ||
6953 | if (filter->offset + filter->size < offset) | |
6954 | return false; | |
6955 | ||
6956 | return true; | |
6957 | } | |
6958 | ||
6959 | static void __perf_addr_filters_adjust(struct perf_event *event, void *data) | |
6960 | { | |
6961 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
6962 | struct vm_area_struct *vma = data; | |
6963 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags; | |
6964 | struct file *file = vma->vm_file; | |
6965 | struct perf_addr_filter *filter; | |
6966 | unsigned int restart = 0, count = 0; | |
6967 | ||
6968 | if (!has_addr_filter(event)) | |
6969 | return; | |
6970 | ||
6971 | if (!file) | |
6972 | return; | |
6973 | ||
6974 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
6975 | list_for_each_entry(filter, &ifh->list, entry) { | |
6976 | if (perf_addr_filter_match(filter, file, off, | |
6977 | vma->vm_end - vma->vm_start)) { | |
6978 | event->addr_filters_offs[count] = vma->vm_start; | |
6979 | restart++; | |
6980 | } | |
6981 | ||
6982 | count++; | |
6983 | } | |
6984 | ||
6985 | if (restart) | |
6986 | event->addr_filters_gen++; | |
6987 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
6988 | ||
6989 | if (restart) | |
767ae086 | 6990 | perf_event_stop(event, 1); |
375637bc AS |
6991 | } |
6992 | ||
6993 | /* | |
6994 | * Adjust all task's events' filters to the new vma | |
6995 | */ | |
6996 | static void perf_addr_filters_adjust(struct vm_area_struct *vma) | |
6997 | { | |
6998 | struct perf_event_context *ctx; | |
6999 | int ctxn; | |
7000 | ||
12b40a23 MP |
7001 | /* |
7002 | * Data tracing isn't supported yet and as such there is no need | |
7003 | * to keep track of anything that isn't related to executable code: | |
7004 | */ | |
7005 | if (!(vma->vm_flags & VM_EXEC)) | |
7006 | return; | |
7007 | ||
375637bc AS |
7008 | rcu_read_lock(); |
7009 | for_each_task_context_nr(ctxn) { | |
7010 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
7011 | if (!ctx) | |
7012 | continue; | |
7013 | ||
aab5b71e | 7014 | perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true); |
375637bc AS |
7015 | } |
7016 | rcu_read_unlock(); | |
7017 | } | |
7018 | ||
3af9e859 | 7019 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 7020 | { |
9ee318a7 PZ |
7021 | struct perf_mmap_event mmap_event; |
7022 | ||
cdd6c482 | 7023 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
7024 | return; |
7025 | ||
7026 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 7027 | .vma = vma, |
573402db PZ |
7028 | /* .file_name */ |
7029 | /* .file_size */ | |
cdd6c482 | 7030 | .event_id = { |
573402db | 7031 | .header = { |
cdd6c482 | 7032 | .type = PERF_RECORD_MMAP, |
39447b38 | 7033 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
7034 | /* .size */ |
7035 | }, | |
7036 | /* .pid */ | |
7037 | /* .tid */ | |
089dd79d PZ |
7038 | .start = vma->vm_start, |
7039 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 7040 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 7041 | }, |
13d7a241 SE |
7042 | /* .maj (attr_mmap2 only) */ |
7043 | /* .min (attr_mmap2 only) */ | |
7044 | /* .ino (attr_mmap2 only) */ | |
7045 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
7046 | /* .prot (attr_mmap2 only) */ |
7047 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
7048 | }; |
7049 | ||
375637bc | 7050 | perf_addr_filters_adjust(vma); |
cdd6c482 | 7051 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
7052 | } |
7053 | ||
68db7e98 AS |
7054 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
7055 | unsigned long size, u64 flags) | |
7056 | { | |
7057 | struct perf_output_handle handle; | |
7058 | struct perf_sample_data sample; | |
7059 | struct perf_aux_event { | |
7060 | struct perf_event_header header; | |
7061 | u64 offset; | |
7062 | u64 size; | |
7063 | u64 flags; | |
7064 | } rec = { | |
7065 | .header = { | |
7066 | .type = PERF_RECORD_AUX, | |
7067 | .misc = 0, | |
7068 | .size = sizeof(rec), | |
7069 | }, | |
7070 | .offset = head, | |
7071 | .size = size, | |
7072 | .flags = flags, | |
7073 | }; | |
7074 | int ret; | |
7075 | ||
7076 | perf_event_header__init_id(&rec.header, &sample, event); | |
7077 | ret = perf_output_begin(&handle, event, rec.header.size); | |
7078 | ||
7079 | if (ret) | |
7080 | return; | |
7081 | ||
7082 | perf_output_put(&handle, rec); | |
7083 | perf_event__output_id_sample(event, &handle, &sample); | |
7084 | ||
7085 | perf_output_end(&handle); | |
7086 | } | |
7087 | ||
f38b0dbb KL |
7088 | /* |
7089 | * Lost/dropped samples logging | |
7090 | */ | |
7091 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
7092 | { | |
7093 | struct perf_output_handle handle; | |
7094 | struct perf_sample_data sample; | |
7095 | int ret; | |
7096 | ||
7097 | struct { | |
7098 | struct perf_event_header header; | |
7099 | u64 lost; | |
7100 | } lost_samples_event = { | |
7101 | .header = { | |
7102 | .type = PERF_RECORD_LOST_SAMPLES, | |
7103 | .misc = 0, | |
7104 | .size = sizeof(lost_samples_event), | |
7105 | }, | |
7106 | .lost = lost, | |
7107 | }; | |
7108 | ||
7109 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
7110 | ||
7111 | ret = perf_output_begin(&handle, event, | |
7112 | lost_samples_event.header.size); | |
7113 | if (ret) | |
7114 | return; | |
7115 | ||
7116 | perf_output_put(&handle, lost_samples_event); | |
7117 | perf_event__output_id_sample(event, &handle, &sample); | |
7118 | perf_output_end(&handle); | |
7119 | } | |
7120 | ||
45ac1403 AH |
7121 | /* |
7122 | * context_switch tracking | |
7123 | */ | |
7124 | ||
7125 | struct perf_switch_event { | |
7126 | struct task_struct *task; | |
7127 | struct task_struct *next_prev; | |
7128 | ||
7129 | struct { | |
7130 | struct perf_event_header header; | |
7131 | u32 next_prev_pid; | |
7132 | u32 next_prev_tid; | |
7133 | } event_id; | |
7134 | }; | |
7135 | ||
7136 | static int perf_event_switch_match(struct perf_event *event) | |
7137 | { | |
7138 | return event->attr.context_switch; | |
7139 | } | |
7140 | ||
7141 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
7142 | { | |
7143 | struct perf_switch_event *se = data; | |
7144 | struct perf_output_handle handle; | |
7145 | struct perf_sample_data sample; | |
7146 | int ret; | |
7147 | ||
7148 | if (!perf_event_switch_match(event)) | |
7149 | return; | |
7150 | ||
7151 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
7152 | if (event->ctx->task) { | |
7153 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
7154 | se->event_id.header.size = sizeof(se->event_id.header); | |
7155 | } else { | |
7156 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
7157 | se->event_id.header.size = sizeof(se->event_id); | |
7158 | se->event_id.next_prev_pid = | |
7159 | perf_event_pid(event, se->next_prev); | |
7160 | se->event_id.next_prev_tid = | |
7161 | perf_event_tid(event, se->next_prev); | |
7162 | } | |
7163 | ||
7164 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
7165 | ||
7166 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
7167 | if (ret) | |
7168 | return; | |
7169 | ||
7170 | if (event->ctx->task) | |
7171 | perf_output_put(&handle, se->event_id.header); | |
7172 | else | |
7173 | perf_output_put(&handle, se->event_id); | |
7174 | ||
7175 | perf_event__output_id_sample(event, &handle, &sample); | |
7176 | ||
7177 | perf_output_end(&handle); | |
7178 | } | |
7179 | ||
7180 | static void perf_event_switch(struct task_struct *task, | |
7181 | struct task_struct *next_prev, bool sched_in) | |
7182 | { | |
7183 | struct perf_switch_event switch_event; | |
7184 | ||
7185 | /* N.B. caller checks nr_switch_events != 0 */ | |
7186 | ||
7187 | switch_event = (struct perf_switch_event){ | |
7188 | .task = task, | |
7189 | .next_prev = next_prev, | |
7190 | .event_id = { | |
7191 | .header = { | |
7192 | /* .type */ | |
7193 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
7194 | /* .size */ | |
7195 | }, | |
7196 | /* .next_prev_pid */ | |
7197 | /* .next_prev_tid */ | |
7198 | }, | |
7199 | }; | |
7200 | ||
aab5b71e | 7201 | perf_iterate_sb(perf_event_switch_output, |
45ac1403 AH |
7202 | &switch_event, |
7203 | NULL); | |
7204 | } | |
7205 | ||
a78ac325 PZ |
7206 | /* |
7207 | * IRQ throttle logging | |
7208 | */ | |
7209 | ||
cdd6c482 | 7210 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
7211 | { |
7212 | struct perf_output_handle handle; | |
c980d109 | 7213 | struct perf_sample_data sample; |
a78ac325 PZ |
7214 | int ret; |
7215 | ||
7216 | struct { | |
7217 | struct perf_event_header header; | |
7218 | u64 time; | |
cca3f454 | 7219 | u64 id; |
7f453c24 | 7220 | u64 stream_id; |
a78ac325 PZ |
7221 | } throttle_event = { |
7222 | .header = { | |
cdd6c482 | 7223 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
7224 | .misc = 0, |
7225 | .size = sizeof(throttle_event), | |
7226 | }, | |
34f43927 | 7227 | .time = perf_event_clock(event), |
cdd6c482 IM |
7228 | .id = primary_event_id(event), |
7229 | .stream_id = event->id, | |
a78ac325 PZ |
7230 | }; |
7231 | ||
966ee4d6 | 7232 | if (enable) |
cdd6c482 | 7233 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 7234 | |
c980d109 ACM |
7235 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
7236 | ||
7237 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 7238 | throttle_event.header.size); |
a78ac325 PZ |
7239 | if (ret) |
7240 | return; | |
7241 | ||
7242 | perf_output_put(&handle, throttle_event); | |
c980d109 | 7243 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
7244 | perf_output_end(&handle); |
7245 | } | |
7246 | ||
ec0d7729 AS |
7247 | static void perf_log_itrace_start(struct perf_event *event) |
7248 | { | |
7249 | struct perf_output_handle handle; | |
7250 | struct perf_sample_data sample; | |
7251 | struct perf_aux_event { | |
7252 | struct perf_event_header header; | |
7253 | u32 pid; | |
7254 | u32 tid; | |
7255 | } rec; | |
7256 | int ret; | |
7257 | ||
7258 | if (event->parent) | |
7259 | event = event->parent; | |
7260 | ||
7261 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
7262 | event->hw.itrace_started) | |
7263 | return; | |
7264 | ||
ec0d7729 AS |
7265 | rec.header.type = PERF_RECORD_ITRACE_START; |
7266 | rec.header.misc = 0; | |
7267 | rec.header.size = sizeof(rec); | |
7268 | rec.pid = perf_event_pid(event, current); | |
7269 | rec.tid = perf_event_tid(event, current); | |
7270 | ||
7271 | perf_event_header__init_id(&rec.header, &sample, event); | |
7272 | ret = perf_output_begin(&handle, event, rec.header.size); | |
7273 | ||
7274 | if (ret) | |
7275 | return; | |
7276 | ||
7277 | perf_output_put(&handle, rec); | |
7278 | perf_event__output_id_sample(event, &handle, &sample); | |
7279 | ||
7280 | perf_output_end(&handle); | |
7281 | } | |
7282 | ||
475113d9 JO |
7283 | static int |
7284 | __perf_event_account_interrupt(struct perf_event *event, int throttle) | |
f6c7d5fe | 7285 | { |
cdd6c482 | 7286 | struct hw_perf_event *hwc = &event->hw; |
79f14641 | 7287 | int ret = 0; |
475113d9 | 7288 | u64 seq; |
96398826 | 7289 | |
e050e3f0 SE |
7290 | seq = __this_cpu_read(perf_throttled_seq); |
7291 | if (seq != hwc->interrupts_seq) { | |
7292 | hwc->interrupts_seq = seq; | |
7293 | hwc->interrupts = 1; | |
7294 | } else { | |
7295 | hwc->interrupts++; | |
7296 | if (unlikely(throttle | |
7297 | && hwc->interrupts >= max_samples_per_tick)) { | |
7298 | __this_cpu_inc(perf_throttled_count); | |
555e0c1e | 7299 | tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); |
163ec435 PZ |
7300 | hwc->interrupts = MAX_INTERRUPTS; |
7301 | perf_log_throttle(event, 0); | |
a78ac325 PZ |
7302 | ret = 1; |
7303 | } | |
e050e3f0 | 7304 | } |
60db5e09 | 7305 | |
cdd6c482 | 7306 | if (event->attr.freq) { |
def0a9b2 | 7307 | u64 now = perf_clock(); |
abd50713 | 7308 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 7309 | |
abd50713 | 7310 | hwc->freq_time_stamp = now; |
bd2b5b12 | 7311 | |
abd50713 | 7312 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 7313 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
7314 | } |
7315 | ||
475113d9 JO |
7316 | return ret; |
7317 | } | |
7318 | ||
7319 | int perf_event_account_interrupt(struct perf_event *event) | |
7320 | { | |
7321 | return __perf_event_account_interrupt(event, 1); | |
7322 | } | |
7323 | ||
cc1582c2 JY |
7324 | static bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs) |
7325 | { | |
7326 | /* | |
7327 | * Due to interrupt latency (AKA "skid"), we may enter the | |
7328 | * kernel before taking an overflow, even if the PMU is only | |
7329 | * counting user events. | |
7330 | * To avoid leaking information to userspace, we must always | |
7331 | * reject kernel samples when exclude_kernel is set. | |
7332 | */ | |
7333 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
7334 | return false; | |
7335 | ||
7336 | return true; | |
7337 | } | |
7338 | ||
475113d9 JO |
7339 | /* |
7340 | * Generic event overflow handling, sampling. | |
7341 | */ | |
7342 | ||
7343 | static int __perf_event_overflow(struct perf_event *event, | |
7344 | int throttle, struct perf_sample_data *data, | |
7345 | struct pt_regs *regs) | |
7346 | { | |
7347 | int events = atomic_read(&event->event_limit); | |
7348 | int ret = 0; | |
7349 | ||
7350 | /* | |
7351 | * Non-sampling counters might still use the PMI to fold short | |
7352 | * hardware counters, ignore those. | |
7353 | */ | |
7354 | if (unlikely(!is_sampling_event(event))) | |
7355 | return 0; | |
7356 | ||
7357 | ret = __perf_event_account_interrupt(event, throttle); | |
7358 | ||
cc1582c2 JY |
7359 | /* |
7360 | * For security, drop the skid kernel samples if necessary. | |
7361 | */ | |
7362 | if (!sample_is_allowed(event, regs)) | |
7363 | return ret; | |
7364 | ||
2023b359 PZ |
7365 | /* |
7366 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 7367 | * events |
2023b359 PZ |
7368 | */ |
7369 | ||
cdd6c482 IM |
7370 | event->pending_kill = POLL_IN; |
7371 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 7372 | ret = 1; |
cdd6c482 | 7373 | event->pending_kill = POLL_HUP; |
5aab90ce JO |
7374 | |
7375 | perf_event_disable_inatomic(event); | |
79f14641 PZ |
7376 | } |
7377 | ||
aa6a5f3c | 7378 | READ_ONCE(event->overflow_handler)(event, data, regs); |
453f19ee | 7379 | |
fed66e2c | 7380 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
7381 | event->pending_wakeup = 1; |
7382 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
7383 | } |
7384 | ||
79f14641 | 7385 | return ret; |
f6c7d5fe PZ |
7386 | } |
7387 | ||
a8b0ca17 | 7388 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
7389 | struct perf_sample_data *data, |
7390 | struct pt_regs *regs) | |
850bc73f | 7391 | { |
a8b0ca17 | 7392 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
7393 | } |
7394 | ||
15dbf27c | 7395 | /* |
cdd6c482 | 7396 | * Generic software event infrastructure |
15dbf27c PZ |
7397 | */ |
7398 | ||
b28ab83c PZ |
7399 | struct swevent_htable { |
7400 | struct swevent_hlist *swevent_hlist; | |
7401 | struct mutex hlist_mutex; | |
7402 | int hlist_refcount; | |
7403 | ||
7404 | /* Recursion avoidance in each contexts */ | |
7405 | int recursion[PERF_NR_CONTEXTS]; | |
7406 | }; | |
7407 | ||
7408 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
7409 | ||
7b4b6658 | 7410 | /* |
cdd6c482 IM |
7411 | * We directly increment event->count and keep a second value in |
7412 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
7413 | * is kept in the range [-sample_period, 0] so that we can use the |
7414 | * sign as trigger. | |
7415 | */ | |
7416 | ||
ab573844 | 7417 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 7418 | { |
cdd6c482 | 7419 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
7420 | u64 period = hwc->last_period; |
7421 | u64 nr, offset; | |
7422 | s64 old, val; | |
7423 | ||
7424 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
7425 | |
7426 | again: | |
e7850595 | 7427 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
7428 | if (val < 0) |
7429 | return 0; | |
15dbf27c | 7430 | |
7b4b6658 PZ |
7431 | nr = div64_u64(period + val, period); |
7432 | offset = nr * period; | |
7433 | val -= offset; | |
e7850595 | 7434 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 7435 | goto again; |
15dbf27c | 7436 | |
7b4b6658 | 7437 | return nr; |
15dbf27c PZ |
7438 | } |
7439 | ||
0cff784a | 7440 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 7441 | struct perf_sample_data *data, |
5622f295 | 7442 | struct pt_regs *regs) |
15dbf27c | 7443 | { |
cdd6c482 | 7444 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 7445 | int throttle = 0; |
15dbf27c | 7446 | |
0cff784a PZ |
7447 | if (!overflow) |
7448 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 7449 | |
7b4b6658 PZ |
7450 | if (hwc->interrupts == MAX_INTERRUPTS) |
7451 | return; | |
15dbf27c | 7452 | |
7b4b6658 | 7453 | for (; overflow; overflow--) { |
a8b0ca17 | 7454 | if (__perf_event_overflow(event, throttle, |
5622f295 | 7455 | data, regs)) { |
7b4b6658 PZ |
7456 | /* |
7457 | * We inhibit the overflow from happening when | |
7458 | * hwc->interrupts == MAX_INTERRUPTS. | |
7459 | */ | |
7460 | break; | |
7461 | } | |
cf450a73 | 7462 | throttle = 1; |
7b4b6658 | 7463 | } |
15dbf27c PZ |
7464 | } |
7465 | ||
a4eaf7f1 | 7466 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 7467 | struct perf_sample_data *data, |
5622f295 | 7468 | struct pt_regs *regs) |
7b4b6658 | 7469 | { |
cdd6c482 | 7470 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 7471 | |
e7850595 | 7472 | local64_add(nr, &event->count); |
d6d020e9 | 7473 | |
0cff784a PZ |
7474 | if (!regs) |
7475 | return; | |
7476 | ||
6c7e550f | 7477 | if (!is_sampling_event(event)) |
7b4b6658 | 7478 | return; |
d6d020e9 | 7479 | |
5d81e5cf AV |
7480 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
7481 | data->period = nr; | |
7482 | return perf_swevent_overflow(event, 1, data, regs); | |
7483 | } else | |
7484 | data->period = event->hw.last_period; | |
7485 | ||
0cff784a | 7486 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 7487 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 7488 | |
e7850595 | 7489 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 7490 | return; |
df1a132b | 7491 | |
a8b0ca17 | 7492 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
7493 | } |
7494 | ||
f5ffe02e FW |
7495 | static int perf_exclude_event(struct perf_event *event, |
7496 | struct pt_regs *regs) | |
7497 | { | |
a4eaf7f1 | 7498 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 7499 | return 1; |
a4eaf7f1 | 7500 | |
f5ffe02e FW |
7501 | if (regs) { |
7502 | if (event->attr.exclude_user && user_mode(regs)) | |
7503 | return 1; | |
7504 | ||
7505 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
7506 | return 1; | |
7507 | } | |
7508 | ||
7509 | return 0; | |
7510 | } | |
7511 | ||
cdd6c482 | 7512 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 7513 | enum perf_type_id type, |
6fb2915d LZ |
7514 | u32 event_id, |
7515 | struct perf_sample_data *data, | |
7516 | struct pt_regs *regs) | |
15dbf27c | 7517 | { |
cdd6c482 | 7518 | if (event->attr.type != type) |
a21ca2ca | 7519 | return 0; |
f5ffe02e | 7520 | |
cdd6c482 | 7521 | if (event->attr.config != event_id) |
15dbf27c PZ |
7522 | return 0; |
7523 | ||
f5ffe02e FW |
7524 | if (perf_exclude_event(event, regs)) |
7525 | return 0; | |
15dbf27c PZ |
7526 | |
7527 | return 1; | |
7528 | } | |
7529 | ||
76e1d904 FW |
7530 | static inline u64 swevent_hash(u64 type, u32 event_id) |
7531 | { | |
7532 | u64 val = event_id | (type << 32); | |
7533 | ||
7534 | return hash_64(val, SWEVENT_HLIST_BITS); | |
7535 | } | |
7536 | ||
49f135ed FW |
7537 | static inline struct hlist_head * |
7538 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 7539 | { |
49f135ed FW |
7540 | u64 hash = swevent_hash(type, event_id); |
7541 | ||
7542 | return &hlist->heads[hash]; | |
7543 | } | |
76e1d904 | 7544 | |
49f135ed FW |
7545 | /* For the read side: events when they trigger */ |
7546 | static inline struct hlist_head * | |
b28ab83c | 7547 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
7548 | { |
7549 | struct swevent_hlist *hlist; | |
76e1d904 | 7550 | |
b28ab83c | 7551 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
7552 | if (!hlist) |
7553 | return NULL; | |
7554 | ||
49f135ed FW |
7555 | return __find_swevent_head(hlist, type, event_id); |
7556 | } | |
7557 | ||
7558 | /* For the event head insertion and removal in the hlist */ | |
7559 | static inline struct hlist_head * | |
b28ab83c | 7560 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
7561 | { |
7562 | struct swevent_hlist *hlist; | |
7563 | u32 event_id = event->attr.config; | |
7564 | u64 type = event->attr.type; | |
7565 | ||
7566 | /* | |
7567 | * Event scheduling is always serialized against hlist allocation | |
7568 | * and release. Which makes the protected version suitable here. | |
7569 | * The context lock guarantees that. | |
7570 | */ | |
b28ab83c | 7571 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
7572 | lockdep_is_held(&event->ctx->lock)); |
7573 | if (!hlist) | |
7574 | return NULL; | |
7575 | ||
7576 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
7577 | } |
7578 | ||
7579 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 7580 | u64 nr, |
76e1d904 FW |
7581 | struct perf_sample_data *data, |
7582 | struct pt_regs *regs) | |
15dbf27c | 7583 | { |
4a32fea9 | 7584 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 7585 | struct perf_event *event; |
76e1d904 | 7586 | struct hlist_head *head; |
15dbf27c | 7587 | |
76e1d904 | 7588 | rcu_read_lock(); |
b28ab83c | 7589 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
7590 | if (!head) |
7591 | goto end; | |
7592 | ||
b67bfe0d | 7593 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 7594 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 7595 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 7596 | } |
76e1d904 FW |
7597 | end: |
7598 | rcu_read_unlock(); | |
15dbf27c PZ |
7599 | } |
7600 | ||
86038c5e PZI |
7601 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
7602 | ||
4ed7c92d | 7603 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 7604 | { |
4a32fea9 | 7605 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 7606 | |
b28ab83c | 7607 | return get_recursion_context(swhash->recursion); |
96f6d444 | 7608 | } |
645e8cc0 | 7609 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 7610 | |
98b5c2c6 | 7611 | void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 7612 | { |
4a32fea9 | 7613 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 7614 | |
b28ab83c | 7615 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 7616 | } |
15dbf27c | 7617 | |
86038c5e | 7618 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 7619 | { |
a4234bfc | 7620 | struct perf_sample_data data; |
4ed7c92d | 7621 | |
86038c5e | 7622 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 7623 | return; |
a4234bfc | 7624 | |
fd0d000b | 7625 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 7626 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
7627 | } |
7628 | ||
7629 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
7630 | { | |
7631 | int rctx; | |
7632 | ||
7633 | preempt_disable_notrace(); | |
7634 | rctx = perf_swevent_get_recursion_context(); | |
7635 | if (unlikely(rctx < 0)) | |
7636 | goto fail; | |
7637 | ||
7638 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
7639 | |
7640 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 7641 | fail: |
1c024eca | 7642 | preempt_enable_notrace(); |
b8e83514 PZ |
7643 | } |
7644 | ||
cdd6c482 | 7645 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 7646 | { |
15dbf27c PZ |
7647 | } |
7648 | ||
a4eaf7f1 | 7649 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 7650 | { |
4a32fea9 | 7651 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 7652 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
7653 | struct hlist_head *head; |
7654 | ||
6c7e550f | 7655 | if (is_sampling_event(event)) { |
7b4b6658 | 7656 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 7657 | perf_swevent_set_period(event); |
7b4b6658 | 7658 | } |
76e1d904 | 7659 | |
a4eaf7f1 PZ |
7660 | hwc->state = !(flags & PERF_EF_START); |
7661 | ||
b28ab83c | 7662 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 7663 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
7664 | return -EINVAL; |
7665 | ||
7666 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 7667 | perf_event_update_userpage(event); |
76e1d904 | 7668 | |
15dbf27c PZ |
7669 | return 0; |
7670 | } | |
7671 | ||
a4eaf7f1 | 7672 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 7673 | { |
76e1d904 | 7674 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
7675 | } |
7676 | ||
a4eaf7f1 | 7677 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 7678 | { |
a4eaf7f1 | 7679 | event->hw.state = 0; |
d6d020e9 | 7680 | } |
aa9c4c0f | 7681 | |
a4eaf7f1 | 7682 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 7683 | { |
a4eaf7f1 | 7684 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
7685 | } |
7686 | ||
49f135ed FW |
7687 | /* Deref the hlist from the update side */ |
7688 | static inline struct swevent_hlist * | |
b28ab83c | 7689 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 7690 | { |
b28ab83c PZ |
7691 | return rcu_dereference_protected(swhash->swevent_hlist, |
7692 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
7693 | } |
7694 | ||
b28ab83c | 7695 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 7696 | { |
b28ab83c | 7697 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 7698 | |
49f135ed | 7699 | if (!hlist) |
76e1d904 FW |
7700 | return; |
7701 | ||
70691d4a | 7702 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 7703 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
7704 | } |
7705 | ||
3b364d7b | 7706 | static void swevent_hlist_put_cpu(int cpu) |
76e1d904 | 7707 | { |
b28ab83c | 7708 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 7709 | |
b28ab83c | 7710 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 7711 | |
b28ab83c PZ |
7712 | if (!--swhash->hlist_refcount) |
7713 | swevent_hlist_release(swhash); | |
76e1d904 | 7714 | |
b28ab83c | 7715 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
7716 | } |
7717 | ||
3b364d7b | 7718 | static void swevent_hlist_put(void) |
76e1d904 FW |
7719 | { |
7720 | int cpu; | |
7721 | ||
76e1d904 | 7722 | for_each_possible_cpu(cpu) |
3b364d7b | 7723 | swevent_hlist_put_cpu(cpu); |
76e1d904 FW |
7724 | } |
7725 | ||
3b364d7b | 7726 | static int swevent_hlist_get_cpu(int cpu) |
76e1d904 | 7727 | { |
b28ab83c | 7728 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
7729 | int err = 0; |
7730 | ||
b28ab83c | 7731 | mutex_lock(&swhash->hlist_mutex); |
a63fbed7 TG |
7732 | if (!swevent_hlist_deref(swhash) && |
7733 | cpumask_test_cpu(cpu, perf_online_mask)) { | |
76e1d904 FW |
7734 | struct swevent_hlist *hlist; |
7735 | ||
7736 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
7737 | if (!hlist) { | |
7738 | err = -ENOMEM; | |
7739 | goto exit; | |
7740 | } | |
b28ab83c | 7741 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 7742 | } |
b28ab83c | 7743 | swhash->hlist_refcount++; |
9ed6060d | 7744 | exit: |
b28ab83c | 7745 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
7746 | |
7747 | return err; | |
7748 | } | |
7749 | ||
3b364d7b | 7750 | static int swevent_hlist_get(void) |
76e1d904 | 7751 | { |
3b364d7b | 7752 | int err, cpu, failed_cpu; |
76e1d904 | 7753 | |
a63fbed7 | 7754 | mutex_lock(&pmus_lock); |
76e1d904 | 7755 | for_each_possible_cpu(cpu) { |
3b364d7b | 7756 | err = swevent_hlist_get_cpu(cpu); |
76e1d904 FW |
7757 | if (err) { |
7758 | failed_cpu = cpu; | |
7759 | goto fail; | |
7760 | } | |
7761 | } | |
a63fbed7 | 7762 | mutex_unlock(&pmus_lock); |
76e1d904 | 7763 | return 0; |
9ed6060d | 7764 | fail: |
76e1d904 FW |
7765 | for_each_possible_cpu(cpu) { |
7766 | if (cpu == failed_cpu) | |
7767 | break; | |
3b364d7b | 7768 | swevent_hlist_put_cpu(cpu); |
76e1d904 | 7769 | } |
a63fbed7 | 7770 | mutex_unlock(&pmus_lock); |
76e1d904 FW |
7771 | return err; |
7772 | } | |
7773 | ||
c5905afb | 7774 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 7775 | |
b0a873eb PZ |
7776 | static void sw_perf_event_destroy(struct perf_event *event) |
7777 | { | |
7778 | u64 event_id = event->attr.config; | |
95476b64 | 7779 | |
b0a873eb PZ |
7780 | WARN_ON(event->parent); |
7781 | ||
c5905afb | 7782 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
3b364d7b | 7783 | swevent_hlist_put(); |
b0a873eb PZ |
7784 | } |
7785 | ||
7786 | static int perf_swevent_init(struct perf_event *event) | |
7787 | { | |
8176cced | 7788 | u64 event_id = event->attr.config; |
b0a873eb PZ |
7789 | |
7790 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7791 | return -ENOENT; | |
7792 | ||
2481c5fa SE |
7793 | /* |
7794 | * no branch sampling for software events | |
7795 | */ | |
7796 | if (has_branch_stack(event)) | |
7797 | return -EOPNOTSUPP; | |
7798 | ||
b0a873eb PZ |
7799 | switch (event_id) { |
7800 | case PERF_COUNT_SW_CPU_CLOCK: | |
7801 | case PERF_COUNT_SW_TASK_CLOCK: | |
7802 | return -ENOENT; | |
7803 | ||
7804 | default: | |
7805 | break; | |
7806 | } | |
7807 | ||
ce677831 | 7808 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
7809 | return -ENOENT; |
7810 | ||
7811 | if (!event->parent) { | |
7812 | int err; | |
7813 | ||
3b364d7b | 7814 | err = swevent_hlist_get(); |
b0a873eb PZ |
7815 | if (err) |
7816 | return err; | |
7817 | ||
c5905afb | 7818 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
7819 | event->destroy = sw_perf_event_destroy; |
7820 | } | |
7821 | ||
7822 | return 0; | |
7823 | } | |
7824 | ||
7825 | static struct pmu perf_swevent = { | |
89a1e187 | 7826 | .task_ctx_nr = perf_sw_context, |
95476b64 | 7827 | |
34f43927 PZ |
7828 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7829 | ||
b0a873eb | 7830 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
7831 | .add = perf_swevent_add, |
7832 | .del = perf_swevent_del, | |
7833 | .start = perf_swevent_start, | |
7834 | .stop = perf_swevent_stop, | |
1c024eca | 7835 | .read = perf_swevent_read, |
1c024eca PZ |
7836 | }; |
7837 | ||
b0a873eb PZ |
7838 | #ifdef CONFIG_EVENT_TRACING |
7839 | ||
1c024eca PZ |
7840 | static int perf_tp_filter_match(struct perf_event *event, |
7841 | struct perf_sample_data *data) | |
7842 | { | |
7e3f977e | 7843 | void *record = data->raw->frag.data; |
1c024eca | 7844 | |
b71b437e PZ |
7845 | /* only top level events have filters set */ |
7846 | if (event->parent) | |
7847 | event = event->parent; | |
7848 | ||
1c024eca PZ |
7849 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
7850 | return 1; | |
7851 | return 0; | |
7852 | } | |
7853 | ||
7854 | static int perf_tp_event_match(struct perf_event *event, | |
7855 | struct perf_sample_data *data, | |
7856 | struct pt_regs *regs) | |
7857 | { | |
a0f7d0f7 FW |
7858 | if (event->hw.state & PERF_HES_STOPPED) |
7859 | return 0; | |
580d607c PZ |
7860 | /* |
7861 | * All tracepoints are from kernel-space. | |
7862 | */ | |
7863 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
7864 | return 0; |
7865 | ||
7866 | if (!perf_tp_filter_match(event, data)) | |
7867 | return 0; | |
7868 | ||
7869 | return 1; | |
7870 | } | |
7871 | ||
85b67bcb AS |
7872 | void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, |
7873 | struct trace_event_call *call, u64 count, | |
7874 | struct pt_regs *regs, struct hlist_head *head, | |
7875 | struct task_struct *task) | |
7876 | { | |
7877 | struct bpf_prog *prog = call->prog; | |
7878 | ||
7879 | if (prog) { | |
7880 | *(struct pt_regs **)raw_data = regs; | |
7881 | if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) { | |
7882 | perf_swevent_put_recursion_context(rctx); | |
7883 | return; | |
7884 | } | |
7885 | } | |
7886 | perf_tp_event(call->event.type, count, raw_data, size, regs, head, | |
7887 | rctx, task); | |
7888 | } | |
7889 | EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit); | |
7890 | ||
1e1dcd93 | 7891 | void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, |
e6dab5ff AV |
7892 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
7893 | struct task_struct *task) | |
95476b64 FW |
7894 | { |
7895 | struct perf_sample_data data; | |
1c024eca | 7896 | struct perf_event *event; |
1c024eca | 7897 | |
95476b64 | 7898 | struct perf_raw_record raw = { |
7e3f977e DB |
7899 | .frag = { |
7900 | .size = entry_size, | |
7901 | .data = record, | |
7902 | }, | |
95476b64 FW |
7903 | }; |
7904 | ||
1e1dcd93 | 7905 | perf_sample_data_init(&data, 0, 0); |
95476b64 FW |
7906 | data.raw = &raw; |
7907 | ||
1e1dcd93 AS |
7908 | perf_trace_buf_update(record, event_type); |
7909 | ||
b67bfe0d | 7910 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 7911 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 7912 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 7913 | } |
ecc55f84 | 7914 | |
e6dab5ff AV |
7915 | /* |
7916 | * If we got specified a target task, also iterate its context and | |
7917 | * deliver this event there too. | |
7918 | */ | |
7919 | if (task && task != current) { | |
7920 | struct perf_event_context *ctx; | |
7921 | struct trace_entry *entry = record; | |
7922 | ||
7923 | rcu_read_lock(); | |
7924 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
7925 | if (!ctx) | |
7926 | goto unlock; | |
7927 | ||
7928 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
7929 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7930 | continue; | |
7931 | if (event->attr.config != entry->type) | |
7932 | continue; | |
7933 | if (perf_tp_event_match(event, &data, regs)) | |
7934 | perf_swevent_event(event, count, &data, regs); | |
7935 | } | |
7936 | unlock: | |
7937 | rcu_read_unlock(); | |
7938 | } | |
7939 | ||
ecc55f84 | 7940 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
7941 | } |
7942 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
7943 | ||
cdd6c482 | 7944 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 7945 | { |
1c024eca | 7946 | perf_trace_destroy(event); |
e077df4f PZ |
7947 | } |
7948 | ||
b0a873eb | 7949 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 7950 | { |
76e1d904 FW |
7951 | int err; |
7952 | ||
b0a873eb PZ |
7953 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
7954 | return -ENOENT; | |
7955 | ||
2481c5fa SE |
7956 | /* |
7957 | * no branch sampling for tracepoint events | |
7958 | */ | |
7959 | if (has_branch_stack(event)) | |
7960 | return -EOPNOTSUPP; | |
7961 | ||
1c024eca PZ |
7962 | err = perf_trace_init(event); |
7963 | if (err) | |
b0a873eb | 7964 | return err; |
e077df4f | 7965 | |
cdd6c482 | 7966 | event->destroy = tp_perf_event_destroy; |
e077df4f | 7967 | |
b0a873eb PZ |
7968 | return 0; |
7969 | } | |
7970 | ||
7971 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
7972 | .task_ctx_nr = perf_sw_context, |
7973 | ||
b0a873eb | 7974 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
7975 | .add = perf_trace_add, |
7976 | .del = perf_trace_del, | |
7977 | .start = perf_swevent_start, | |
7978 | .stop = perf_swevent_stop, | |
b0a873eb | 7979 | .read = perf_swevent_read, |
b0a873eb PZ |
7980 | }; |
7981 | ||
7982 | static inline void perf_tp_register(void) | |
7983 | { | |
2e80a82a | 7984 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 7985 | } |
6fb2915d | 7986 | |
6fb2915d LZ |
7987 | static void perf_event_free_filter(struct perf_event *event) |
7988 | { | |
7989 | ftrace_profile_free_filter(event); | |
7990 | } | |
7991 | ||
aa6a5f3c AS |
7992 | #ifdef CONFIG_BPF_SYSCALL |
7993 | static void bpf_overflow_handler(struct perf_event *event, | |
7994 | struct perf_sample_data *data, | |
7995 | struct pt_regs *regs) | |
7996 | { | |
7997 | struct bpf_perf_event_data_kern ctx = { | |
7998 | .data = data, | |
7999 | .regs = regs, | |
8000 | }; | |
8001 | int ret = 0; | |
8002 | ||
8003 | preempt_disable(); | |
8004 | if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) | |
8005 | goto out; | |
8006 | rcu_read_lock(); | |
88575199 | 8007 | ret = BPF_PROG_RUN(event->prog, &ctx); |
aa6a5f3c AS |
8008 | rcu_read_unlock(); |
8009 | out: | |
8010 | __this_cpu_dec(bpf_prog_active); | |
8011 | preempt_enable(); | |
8012 | if (!ret) | |
8013 | return; | |
8014 | ||
8015 | event->orig_overflow_handler(event, data, regs); | |
8016 | } | |
8017 | ||
8018 | static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) | |
8019 | { | |
8020 | struct bpf_prog *prog; | |
8021 | ||
8022 | if (event->overflow_handler_context) | |
8023 | /* hw breakpoint or kernel counter */ | |
8024 | return -EINVAL; | |
8025 | ||
8026 | if (event->prog) | |
8027 | return -EEXIST; | |
8028 | ||
8029 | prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); | |
8030 | if (IS_ERR(prog)) | |
8031 | return PTR_ERR(prog); | |
8032 | ||
8033 | event->prog = prog; | |
8034 | event->orig_overflow_handler = READ_ONCE(event->overflow_handler); | |
8035 | WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); | |
8036 | return 0; | |
8037 | } | |
8038 | ||
8039 | static void perf_event_free_bpf_handler(struct perf_event *event) | |
8040 | { | |
8041 | struct bpf_prog *prog = event->prog; | |
8042 | ||
8043 | if (!prog) | |
8044 | return; | |
8045 | ||
8046 | WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler); | |
8047 | event->prog = NULL; | |
8048 | bpf_prog_put(prog); | |
8049 | } | |
8050 | #else | |
8051 | static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) | |
8052 | { | |
8053 | return -EOPNOTSUPP; | |
8054 | } | |
8055 | static void perf_event_free_bpf_handler(struct perf_event *event) | |
8056 | { | |
8057 | } | |
8058 | #endif | |
8059 | ||
2541517c AS |
8060 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
8061 | { | |
98b5c2c6 | 8062 | bool is_kprobe, is_tracepoint; |
2541517c AS |
8063 | struct bpf_prog *prog; |
8064 | ||
8065 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
f91840a3 | 8066 | return perf_event_set_bpf_handler(event, prog_fd); |
2541517c AS |
8067 | |
8068 | if (event->tp_event->prog) | |
8069 | return -EEXIST; | |
8070 | ||
98b5c2c6 AS |
8071 | is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; |
8072 | is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; | |
8073 | if (!is_kprobe && !is_tracepoint) | |
8074 | /* bpf programs can only be attached to u/kprobe or tracepoint */ | |
2541517c AS |
8075 | return -EINVAL; |
8076 | ||
8077 | prog = bpf_prog_get(prog_fd); | |
8078 | if (IS_ERR(prog)) | |
8079 | return PTR_ERR(prog); | |
8080 | ||
98b5c2c6 AS |
8081 | if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || |
8082 | (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT)) { | |
2541517c AS |
8083 | /* valid fd, but invalid bpf program type */ |
8084 | bpf_prog_put(prog); | |
8085 | return -EINVAL; | |
8086 | } | |
8087 | ||
32bbe007 AS |
8088 | if (is_tracepoint) { |
8089 | int off = trace_event_get_offsets(event->tp_event); | |
8090 | ||
8091 | if (prog->aux->max_ctx_offset > off) { | |
8092 | bpf_prog_put(prog); | |
8093 | return -EACCES; | |
8094 | } | |
8095 | } | |
2541517c AS |
8096 | event->tp_event->prog = prog; |
8097 | ||
8098 | return 0; | |
8099 | } | |
8100 | ||
8101 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
8102 | { | |
8103 | struct bpf_prog *prog; | |
8104 | ||
aa6a5f3c AS |
8105 | perf_event_free_bpf_handler(event); |
8106 | ||
2541517c AS |
8107 | if (!event->tp_event) |
8108 | return; | |
8109 | ||
8110 | prog = event->tp_event->prog; | |
8111 | if (prog) { | |
8112 | event->tp_event->prog = NULL; | |
1aacde3d | 8113 | bpf_prog_put(prog); |
2541517c AS |
8114 | } |
8115 | } | |
8116 | ||
e077df4f | 8117 | #else |
6fb2915d | 8118 | |
b0a873eb | 8119 | static inline void perf_tp_register(void) |
e077df4f | 8120 | { |
e077df4f | 8121 | } |
6fb2915d | 8122 | |
6fb2915d LZ |
8123 | static void perf_event_free_filter(struct perf_event *event) |
8124 | { | |
8125 | } | |
8126 | ||
2541517c AS |
8127 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
8128 | { | |
8129 | return -ENOENT; | |
8130 | } | |
8131 | ||
8132 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
8133 | { | |
8134 | } | |
07b139c8 | 8135 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 8136 | |
24f1e32c | 8137 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 8138 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 8139 | { |
f5ffe02e FW |
8140 | struct perf_sample_data sample; |
8141 | struct pt_regs *regs = data; | |
8142 | ||
fd0d000b | 8143 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 8144 | |
a4eaf7f1 | 8145 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 8146 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
8147 | } |
8148 | #endif | |
8149 | ||
375637bc AS |
8150 | /* |
8151 | * Allocate a new address filter | |
8152 | */ | |
8153 | static struct perf_addr_filter * | |
8154 | perf_addr_filter_new(struct perf_event *event, struct list_head *filters) | |
8155 | { | |
8156 | int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu); | |
8157 | struct perf_addr_filter *filter; | |
8158 | ||
8159 | filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node); | |
8160 | if (!filter) | |
8161 | return NULL; | |
8162 | ||
8163 | INIT_LIST_HEAD(&filter->entry); | |
8164 | list_add_tail(&filter->entry, filters); | |
8165 | ||
8166 | return filter; | |
8167 | } | |
8168 | ||
8169 | static void free_filters_list(struct list_head *filters) | |
8170 | { | |
8171 | struct perf_addr_filter *filter, *iter; | |
8172 | ||
8173 | list_for_each_entry_safe(filter, iter, filters, entry) { | |
8174 | if (filter->inode) | |
8175 | iput(filter->inode); | |
8176 | list_del(&filter->entry); | |
8177 | kfree(filter); | |
8178 | } | |
8179 | } | |
8180 | ||
8181 | /* | |
8182 | * Free existing address filters and optionally install new ones | |
8183 | */ | |
8184 | static void perf_addr_filters_splice(struct perf_event *event, | |
8185 | struct list_head *head) | |
8186 | { | |
8187 | unsigned long flags; | |
8188 | LIST_HEAD(list); | |
8189 | ||
8190 | if (!has_addr_filter(event)) | |
8191 | return; | |
8192 | ||
8193 | /* don't bother with children, they don't have their own filters */ | |
8194 | if (event->parent) | |
8195 | return; | |
8196 | ||
8197 | raw_spin_lock_irqsave(&event->addr_filters.lock, flags); | |
8198 | ||
8199 | list_splice_init(&event->addr_filters.list, &list); | |
8200 | if (head) | |
8201 | list_splice(head, &event->addr_filters.list); | |
8202 | ||
8203 | raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags); | |
8204 | ||
8205 | free_filters_list(&list); | |
8206 | } | |
8207 | ||
8208 | /* | |
8209 | * Scan through mm's vmas and see if one of them matches the | |
8210 | * @filter; if so, adjust filter's address range. | |
8211 | * Called with mm::mmap_sem down for reading. | |
8212 | */ | |
8213 | static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter, | |
8214 | struct mm_struct *mm) | |
8215 | { | |
8216 | struct vm_area_struct *vma; | |
8217 | ||
8218 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
8219 | struct file *file = vma->vm_file; | |
8220 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT; | |
8221 | unsigned long vma_size = vma->vm_end - vma->vm_start; | |
8222 | ||
8223 | if (!file) | |
8224 | continue; | |
8225 | ||
8226 | if (!perf_addr_filter_match(filter, file, off, vma_size)) | |
8227 | continue; | |
8228 | ||
8229 | return vma->vm_start; | |
8230 | } | |
8231 | ||
8232 | return 0; | |
8233 | } | |
8234 | ||
8235 | /* | |
8236 | * Update event's address range filters based on the | |
8237 | * task's existing mappings, if any. | |
8238 | */ | |
8239 | static void perf_event_addr_filters_apply(struct perf_event *event) | |
8240 | { | |
8241 | struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); | |
8242 | struct task_struct *task = READ_ONCE(event->ctx->task); | |
8243 | struct perf_addr_filter *filter; | |
8244 | struct mm_struct *mm = NULL; | |
8245 | unsigned int count = 0; | |
8246 | unsigned long flags; | |
8247 | ||
8248 | /* | |
8249 | * We may observe TASK_TOMBSTONE, which means that the event tear-down | |
8250 | * will stop on the parent's child_mutex that our caller is also holding | |
8251 | */ | |
8252 | if (task == TASK_TOMBSTONE) | |
8253 | return; | |
8254 | ||
6ce77bfd AS |
8255 | if (!ifh->nr_file_filters) |
8256 | return; | |
8257 | ||
375637bc AS |
8258 | mm = get_task_mm(event->ctx->task); |
8259 | if (!mm) | |
8260 | goto restart; | |
8261 | ||
8262 | down_read(&mm->mmap_sem); | |
8263 | ||
8264 | raw_spin_lock_irqsave(&ifh->lock, flags); | |
8265 | list_for_each_entry(filter, &ifh->list, entry) { | |
8266 | event->addr_filters_offs[count] = 0; | |
8267 | ||
99f5bc9b MP |
8268 | /* |
8269 | * Adjust base offset if the filter is associated to a binary | |
8270 | * that needs to be mapped: | |
8271 | */ | |
8272 | if (filter->inode) | |
375637bc AS |
8273 | event->addr_filters_offs[count] = |
8274 | perf_addr_filter_apply(filter, mm); | |
8275 | ||
8276 | count++; | |
8277 | } | |
8278 | ||
8279 | event->addr_filters_gen++; | |
8280 | raw_spin_unlock_irqrestore(&ifh->lock, flags); | |
8281 | ||
8282 | up_read(&mm->mmap_sem); | |
8283 | ||
8284 | mmput(mm); | |
8285 | ||
8286 | restart: | |
767ae086 | 8287 | perf_event_stop(event, 1); |
375637bc AS |
8288 | } |
8289 | ||
8290 | /* | |
8291 | * Address range filtering: limiting the data to certain | |
8292 | * instruction address ranges. Filters are ioctl()ed to us from | |
8293 | * userspace as ascii strings. | |
8294 | * | |
8295 | * Filter string format: | |
8296 | * | |
8297 | * ACTION RANGE_SPEC | |
8298 | * where ACTION is one of the | |
8299 | * * "filter": limit the trace to this region | |
8300 | * * "start": start tracing from this address | |
8301 | * * "stop": stop tracing at this address/region; | |
8302 | * RANGE_SPEC is | |
8303 | * * for kernel addresses: <start address>[/<size>] | |
8304 | * * for object files: <start address>[/<size>]@</path/to/object/file> | |
8305 | * | |
8306 | * if <size> is not specified, the range is treated as a single address. | |
8307 | */ | |
8308 | enum { | |
e96271f3 | 8309 | IF_ACT_NONE = -1, |
375637bc AS |
8310 | IF_ACT_FILTER, |
8311 | IF_ACT_START, | |
8312 | IF_ACT_STOP, | |
8313 | IF_SRC_FILE, | |
8314 | IF_SRC_KERNEL, | |
8315 | IF_SRC_FILEADDR, | |
8316 | IF_SRC_KERNELADDR, | |
8317 | }; | |
8318 | ||
8319 | enum { | |
8320 | IF_STATE_ACTION = 0, | |
8321 | IF_STATE_SOURCE, | |
8322 | IF_STATE_END, | |
8323 | }; | |
8324 | ||
8325 | static const match_table_t if_tokens = { | |
8326 | { IF_ACT_FILTER, "filter" }, | |
8327 | { IF_ACT_START, "start" }, | |
8328 | { IF_ACT_STOP, "stop" }, | |
8329 | { IF_SRC_FILE, "%u/%u@%s" }, | |
8330 | { IF_SRC_KERNEL, "%u/%u" }, | |
8331 | { IF_SRC_FILEADDR, "%u@%s" }, | |
8332 | { IF_SRC_KERNELADDR, "%u" }, | |
e96271f3 | 8333 | { IF_ACT_NONE, NULL }, |
375637bc AS |
8334 | }; |
8335 | ||
8336 | /* | |
8337 | * Address filter string parser | |
8338 | */ | |
8339 | static int | |
8340 | perf_event_parse_addr_filter(struct perf_event *event, char *fstr, | |
8341 | struct list_head *filters) | |
8342 | { | |
8343 | struct perf_addr_filter *filter = NULL; | |
8344 | char *start, *orig, *filename = NULL; | |
8345 | struct path path; | |
8346 | substring_t args[MAX_OPT_ARGS]; | |
8347 | int state = IF_STATE_ACTION, token; | |
8348 | unsigned int kernel = 0; | |
8349 | int ret = -EINVAL; | |
8350 | ||
8351 | orig = fstr = kstrdup(fstr, GFP_KERNEL); | |
8352 | if (!fstr) | |
8353 | return -ENOMEM; | |
8354 | ||
8355 | while ((start = strsep(&fstr, " ,\n")) != NULL) { | |
8356 | ret = -EINVAL; | |
8357 | ||
8358 | if (!*start) | |
8359 | continue; | |
8360 | ||
8361 | /* filter definition begins */ | |
8362 | if (state == IF_STATE_ACTION) { | |
8363 | filter = perf_addr_filter_new(event, filters); | |
8364 | if (!filter) | |
8365 | goto fail; | |
8366 | } | |
8367 | ||
8368 | token = match_token(start, if_tokens, args); | |
8369 | switch (token) { | |
8370 | case IF_ACT_FILTER: | |
8371 | case IF_ACT_START: | |
8372 | filter->filter = 1; | |
8373 | ||
8374 | case IF_ACT_STOP: | |
8375 | if (state != IF_STATE_ACTION) | |
8376 | goto fail; | |
8377 | ||
8378 | state = IF_STATE_SOURCE; | |
8379 | break; | |
8380 | ||
8381 | case IF_SRC_KERNELADDR: | |
8382 | case IF_SRC_KERNEL: | |
8383 | kernel = 1; | |
8384 | ||
8385 | case IF_SRC_FILEADDR: | |
8386 | case IF_SRC_FILE: | |
8387 | if (state != IF_STATE_SOURCE) | |
8388 | goto fail; | |
8389 | ||
8390 | if (token == IF_SRC_FILE || token == IF_SRC_KERNEL) | |
8391 | filter->range = 1; | |
8392 | ||
8393 | *args[0].to = 0; | |
8394 | ret = kstrtoul(args[0].from, 0, &filter->offset); | |
8395 | if (ret) | |
8396 | goto fail; | |
8397 | ||
8398 | if (filter->range) { | |
8399 | *args[1].to = 0; | |
8400 | ret = kstrtoul(args[1].from, 0, &filter->size); | |
8401 | if (ret) | |
8402 | goto fail; | |
8403 | } | |
8404 | ||
4059ffd0 MP |
8405 | if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) { |
8406 | int fpos = filter->range ? 2 : 1; | |
8407 | ||
8408 | filename = match_strdup(&args[fpos]); | |
375637bc AS |
8409 | if (!filename) { |
8410 | ret = -ENOMEM; | |
8411 | goto fail; | |
8412 | } | |
8413 | } | |
8414 | ||
8415 | state = IF_STATE_END; | |
8416 | break; | |
8417 | ||
8418 | default: | |
8419 | goto fail; | |
8420 | } | |
8421 | ||
8422 | /* | |
8423 | * Filter definition is fully parsed, validate and install it. | |
8424 | * Make sure that it doesn't contradict itself or the event's | |
8425 | * attribute. | |
8426 | */ | |
8427 | if (state == IF_STATE_END) { | |
9ccbfbb1 | 8428 | ret = -EINVAL; |
375637bc AS |
8429 | if (kernel && event->attr.exclude_kernel) |
8430 | goto fail; | |
8431 | ||
8432 | if (!kernel) { | |
8433 | if (!filename) | |
8434 | goto fail; | |
8435 | ||
6ce77bfd AS |
8436 | /* |
8437 | * For now, we only support file-based filters | |
8438 | * in per-task events; doing so for CPU-wide | |
8439 | * events requires additional context switching | |
8440 | * trickery, since same object code will be | |
8441 | * mapped at different virtual addresses in | |
8442 | * different processes. | |
8443 | */ | |
8444 | ret = -EOPNOTSUPP; | |
8445 | if (!event->ctx->task) | |
8446 | goto fail_free_name; | |
8447 | ||
375637bc AS |
8448 | /* look up the path and grab its inode */ |
8449 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
8450 | if (ret) | |
8451 | goto fail_free_name; | |
8452 | ||
8453 | filter->inode = igrab(d_inode(path.dentry)); | |
8454 | path_put(&path); | |
8455 | kfree(filename); | |
8456 | filename = NULL; | |
8457 | ||
8458 | ret = -EINVAL; | |
8459 | if (!filter->inode || | |
8460 | !S_ISREG(filter->inode->i_mode)) | |
8461 | /* free_filters_list() will iput() */ | |
8462 | goto fail; | |
6ce77bfd AS |
8463 | |
8464 | event->addr_filters.nr_file_filters++; | |
375637bc AS |
8465 | } |
8466 | ||
8467 | /* ready to consume more filters */ | |
8468 | state = IF_STATE_ACTION; | |
8469 | filter = NULL; | |
8470 | } | |
8471 | } | |
8472 | ||
8473 | if (state != IF_STATE_ACTION) | |
8474 | goto fail; | |
8475 | ||
8476 | kfree(orig); | |
8477 | ||
8478 | return 0; | |
8479 | ||
8480 | fail_free_name: | |
8481 | kfree(filename); | |
8482 | fail: | |
8483 | free_filters_list(filters); | |
8484 | kfree(orig); | |
8485 | ||
8486 | return ret; | |
8487 | } | |
8488 | ||
8489 | static int | |
8490 | perf_event_set_addr_filter(struct perf_event *event, char *filter_str) | |
8491 | { | |
8492 | LIST_HEAD(filters); | |
8493 | int ret; | |
8494 | ||
8495 | /* | |
8496 | * Since this is called in perf_ioctl() path, we're already holding | |
8497 | * ctx::mutex. | |
8498 | */ | |
8499 | lockdep_assert_held(&event->ctx->mutex); | |
8500 | ||
8501 | if (WARN_ON_ONCE(event->parent)) | |
8502 | return -EINVAL; | |
8503 | ||
375637bc AS |
8504 | ret = perf_event_parse_addr_filter(event, filter_str, &filters); |
8505 | if (ret) | |
6ce77bfd | 8506 | goto fail_clear_files; |
375637bc AS |
8507 | |
8508 | ret = event->pmu->addr_filters_validate(&filters); | |
6ce77bfd AS |
8509 | if (ret) |
8510 | goto fail_free_filters; | |
375637bc AS |
8511 | |
8512 | /* remove existing filters, if any */ | |
8513 | perf_addr_filters_splice(event, &filters); | |
8514 | ||
8515 | /* install new filters */ | |
8516 | perf_event_for_each_child(event, perf_event_addr_filters_apply); | |
8517 | ||
6ce77bfd AS |
8518 | return ret; |
8519 | ||
8520 | fail_free_filters: | |
8521 | free_filters_list(&filters); | |
8522 | ||
8523 | fail_clear_files: | |
8524 | event->addr_filters.nr_file_filters = 0; | |
8525 | ||
375637bc AS |
8526 | return ret; |
8527 | } | |
8528 | ||
c796bbbe AS |
8529 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) |
8530 | { | |
8531 | char *filter_str; | |
8532 | int ret = -EINVAL; | |
8533 | ||
375637bc AS |
8534 | if ((event->attr.type != PERF_TYPE_TRACEPOINT || |
8535 | !IS_ENABLED(CONFIG_EVENT_TRACING)) && | |
8536 | !has_addr_filter(event)) | |
c796bbbe AS |
8537 | return -EINVAL; |
8538 | ||
8539 | filter_str = strndup_user(arg, PAGE_SIZE); | |
8540 | if (IS_ERR(filter_str)) | |
8541 | return PTR_ERR(filter_str); | |
8542 | ||
8543 | if (IS_ENABLED(CONFIG_EVENT_TRACING) && | |
8544 | event->attr.type == PERF_TYPE_TRACEPOINT) | |
8545 | ret = ftrace_profile_set_filter(event, event->attr.config, | |
8546 | filter_str); | |
375637bc AS |
8547 | else if (has_addr_filter(event)) |
8548 | ret = perf_event_set_addr_filter(event, filter_str); | |
c796bbbe AS |
8549 | |
8550 | kfree(filter_str); | |
8551 | return ret; | |
8552 | } | |
8553 | ||
b0a873eb PZ |
8554 | /* |
8555 | * hrtimer based swevent callback | |
8556 | */ | |
f29ac756 | 8557 | |
b0a873eb | 8558 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 8559 | { |
b0a873eb PZ |
8560 | enum hrtimer_restart ret = HRTIMER_RESTART; |
8561 | struct perf_sample_data data; | |
8562 | struct pt_regs *regs; | |
8563 | struct perf_event *event; | |
8564 | u64 period; | |
f29ac756 | 8565 | |
b0a873eb | 8566 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
8567 | |
8568 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
8569 | return HRTIMER_NORESTART; | |
8570 | ||
b0a873eb | 8571 | event->pmu->read(event); |
f344011c | 8572 | |
fd0d000b | 8573 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
8574 | regs = get_irq_regs(); |
8575 | ||
8576 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 8577 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 8578 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
8579 | ret = HRTIMER_NORESTART; |
8580 | } | |
24f1e32c | 8581 | |
b0a873eb PZ |
8582 | period = max_t(u64, 10000, event->hw.sample_period); |
8583 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 8584 | |
b0a873eb | 8585 | return ret; |
f29ac756 PZ |
8586 | } |
8587 | ||
b0a873eb | 8588 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 8589 | { |
b0a873eb | 8590 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
8591 | s64 period; |
8592 | ||
8593 | if (!is_sampling_event(event)) | |
8594 | return; | |
f5ffe02e | 8595 | |
5d508e82 FBH |
8596 | period = local64_read(&hwc->period_left); |
8597 | if (period) { | |
8598 | if (period < 0) | |
8599 | period = 10000; | |
fa407f35 | 8600 | |
5d508e82 FBH |
8601 | local64_set(&hwc->period_left, 0); |
8602 | } else { | |
8603 | period = max_t(u64, 10000, hwc->sample_period); | |
8604 | } | |
3497d206 TG |
8605 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
8606 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 8607 | } |
b0a873eb PZ |
8608 | |
8609 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 8610 | { |
b0a873eb PZ |
8611 | struct hw_perf_event *hwc = &event->hw; |
8612 | ||
6c7e550f | 8613 | if (is_sampling_event(event)) { |
b0a873eb | 8614 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 8615 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
8616 | |
8617 | hrtimer_cancel(&hwc->hrtimer); | |
8618 | } | |
24f1e32c FW |
8619 | } |
8620 | ||
ba3dd36c PZ |
8621 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
8622 | { | |
8623 | struct hw_perf_event *hwc = &event->hw; | |
8624 | ||
8625 | if (!is_sampling_event(event)) | |
8626 | return; | |
8627 | ||
8628 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
8629 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
8630 | ||
8631 | /* | |
8632 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
8633 | * mapping and avoid the whole period adjust feedback stuff. | |
8634 | */ | |
8635 | if (event->attr.freq) { | |
8636 | long freq = event->attr.sample_freq; | |
8637 | ||
8638 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
8639 | hwc->sample_period = event->attr.sample_period; | |
8640 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 8641 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
8642 | event->attr.freq = 0; |
8643 | } | |
8644 | } | |
8645 | ||
b0a873eb PZ |
8646 | /* |
8647 | * Software event: cpu wall time clock | |
8648 | */ | |
8649 | ||
8650 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 8651 | { |
b0a873eb PZ |
8652 | s64 prev; |
8653 | u64 now; | |
8654 | ||
a4eaf7f1 | 8655 | now = local_clock(); |
b0a873eb PZ |
8656 | prev = local64_xchg(&event->hw.prev_count, now); |
8657 | local64_add(now - prev, &event->count); | |
24f1e32c | 8658 | } |
24f1e32c | 8659 | |
a4eaf7f1 | 8660 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 8661 | { |
a4eaf7f1 | 8662 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 8663 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
8664 | } |
8665 | ||
a4eaf7f1 | 8666 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 8667 | { |
b0a873eb PZ |
8668 | perf_swevent_cancel_hrtimer(event); |
8669 | cpu_clock_event_update(event); | |
8670 | } | |
f29ac756 | 8671 | |
a4eaf7f1 PZ |
8672 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
8673 | { | |
8674 | if (flags & PERF_EF_START) | |
8675 | cpu_clock_event_start(event, flags); | |
6a694a60 | 8676 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
8677 | |
8678 | return 0; | |
8679 | } | |
8680 | ||
8681 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
8682 | { | |
8683 | cpu_clock_event_stop(event, flags); | |
8684 | } | |
8685 | ||
b0a873eb PZ |
8686 | static void cpu_clock_event_read(struct perf_event *event) |
8687 | { | |
8688 | cpu_clock_event_update(event); | |
8689 | } | |
f344011c | 8690 | |
b0a873eb PZ |
8691 | static int cpu_clock_event_init(struct perf_event *event) |
8692 | { | |
8693 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
8694 | return -ENOENT; | |
8695 | ||
8696 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
8697 | return -ENOENT; | |
8698 | ||
2481c5fa SE |
8699 | /* |
8700 | * no branch sampling for software events | |
8701 | */ | |
8702 | if (has_branch_stack(event)) | |
8703 | return -EOPNOTSUPP; | |
8704 | ||
ba3dd36c PZ |
8705 | perf_swevent_init_hrtimer(event); |
8706 | ||
b0a873eb | 8707 | return 0; |
f29ac756 PZ |
8708 | } |
8709 | ||
b0a873eb | 8710 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
8711 | .task_ctx_nr = perf_sw_context, |
8712 | ||
34f43927 PZ |
8713 | .capabilities = PERF_PMU_CAP_NO_NMI, |
8714 | ||
b0a873eb | 8715 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
8716 | .add = cpu_clock_event_add, |
8717 | .del = cpu_clock_event_del, | |
8718 | .start = cpu_clock_event_start, | |
8719 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
8720 | .read = cpu_clock_event_read, |
8721 | }; | |
8722 | ||
8723 | /* | |
8724 | * Software event: task time clock | |
8725 | */ | |
8726 | ||
8727 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 8728 | { |
b0a873eb PZ |
8729 | u64 prev; |
8730 | s64 delta; | |
5c92d124 | 8731 | |
b0a873eb PZ |
8732 | prev = local64_xchg(&event->hw.prev_count, now); |
8733 | delta = now - prev; | |
8734 | local64_add(delta, &event->count); | |
8735 | } | |
5c92d124 | 8736 | |
a4eaf7f1 | 8737 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 8738 | { |
a4eaf7f1 | 8739 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 8740 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
8741 | } |
8742 | ||
a4eaf7f1 | 8743 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
8744 | { |
8745 | perf_swevent_cancel_hrtimer(event); | |
8746 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
8747 | } |
8748 | ||
8749 | static int task_clock_event_add(struct perf_event *event, int flags) | |
8750 | { | |
8751 | if (flags & PERF_EF_START) | |
8752 | task_clock_event_start(event, flags); | |
6a694a60 | 8753 | perf_event_update_userpage(event); |
b0a873eb | 8754 | |
a4eaf7f1 PZ |
8755 | return 0; |
8756 | } | |
8757 | ||
8758 | static void task_clock_event_del(struct perf_event *event, int flags) | |
8759 | { | |
8760 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
8761 | } |
8762 | ||
8763 | static void task_clock_event_read(struct perf_event *event) | |
8764 | { | |
768a06e2 PZ |
8765 | u64 now = perf_clock(); |
8766 | u64 delta = now - event->ctx->timestamp; | |
8767 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
8768 | |
8769 | task_clock_event_update(event, time); | |
8770 | } | |
8771 | ||
8772 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 8773 | { |
b0a873eb PZ |
8774 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
8775 | return -ENOENT; | |
8776 | ||
8777 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
8778 | return -ENOENT; | |
8779 | ||
2481c5fa SE |
8780 | /* |
8781 | * no branch sampling for software events | |
8782 | */ | |
8783 | if (has_branch_stack(event)) | |
8784 | return -EOPNOTSUPP; | |
8785 | ||
ba3dd36c PZ |
8786 | perf_swevent_init_hrtimer(event); |
8787 | ||
b0a873eb | 8788 | return 0; |
6fb2915d LZ |
8789 | } |
8790 | ||
b0a873eb | 8791 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
8792 | .task_ctx_nr = perf_sw_context, |
8793 | ||
34f43927 PZ |
8794 | .capabilities = PERF_PMU_CAP_NO_NMI, |
8795 | ||
b0a873eb | 8796 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
8797 | .add = task_clock_event_add, |
8798 | .del = task_clock_event_del, | |
8799 | .start = task_clock_event_start, | |
8800 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
8801 | .read = task_clock_event_read, |
8802 | }; | |
6fb2915d | 8803 | |
ad5133b7 | 8804 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 8805 | { |
e077df4f | 8806 | } |
6fb2915d | 8807 | |
fbbe0701 SB |
8808 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
8809 | { | |
8810 | } | |
8811 | ||
ad5133b7 | 8812 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 8813 | { |
ad5133b7 | 8814 | return 0; |
6fb2915d LZ |
8815 | } |
8816 | ||
18ab2cd3 | 8817 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
8818 | |
8819 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 8820 | { |
fbbe0701 SB |
8821 | __this_cpu_write(nop_txn_flags, flags); |
8822 | ||
8823 | if (flags & ~PERF_PMU_TXN_ADD) | |
8824 | return; | |
8825 | ||
ad5133b7 | 8826 | perf_pmu_disable(pmu); |
6fb2915d LZ |
8827 | } |
8828 | ||
ad5133b7 PZ |
8829 | static int perf_pmu_commit_txn(struct pmu *pmu) |
8830 | { | |
fbbe0701 SB |
8831 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
8832 | ||
8833 | __this_cpu_write(nop_txn_flags, 0); | |
8834 | ||
8835 | if (flags & ~PERF_PMU_TXN_ADD) | |
8836 | return 0; | |
8837 | ||
ad5133b7 PZ |
8838 | perf_pmu_enable(pmu); |
8839 | return 0; | |
8840 | } | |
e077df4f | 8841 | |
ad5133b7 | 8842 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 8843 | { |
fbbe0701 SB |
8844 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
8845 | ||
8846 | __this_cpu_write(nop_txn_flags, 0); | |
8847 | ||
8848 | if (flags & ~PERF_PMU_TXN_ADD) | |
8849 | return; | |
8850 | ||
ad5133b7 | 8851 | perf_pmu_enable(pmu); |
24f1e32c FW |
8852 | } |
8853 | ||
35edc2a5 PZ |
8854 | static int perf_event_idx_default(struct perf_event *event) |
8855 | { | |
c719f560 | 8856 | return 0; |
35edc2a5 PZ |
8857 | } |
8858 | ||
8dc85d54 PZ |
8859 | /* |
8860 | * Ensures all contexts with the same task_ctx_nr have the same | |
8861 | * pmu_cpu_context too. | |
8862 | */ | |
9e317041 | 8863 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 8864 | { |
8dc85d54 | 8865 | struct pmu *pmu; |
b326e956 | 8866 | |
8dc85d54 PZ |
8867 | if (ctxn < 0) |
8868 | return NULL; | |
24f1e32c | 8869 | |
8dc85d54 PZ |
8870 | list_for_each_entry(pmu, &pmus, entry) { |
8871 | if (pmu->task_ctx_nr == ctxn) | |
8872 | return pmu->pmu_cpu_context; | |
8873 | } | |
24f1e32c | 8874 | |
8dc85d54 | 8875 | return NULL; |
24f1e32c FW |
8876 | } |
8877 | ||
51676957 PZ |
8878 | static void free_pmu_context(struct pmu *pmu) |
8879 | { | |
8dc85d54 | 8880 | mutex_lock(&pmus_lock); |
51676957 | 8881 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 | 8882 | mutex_unlock(&pmus_lock); |
24f1e32c | 8883 | } |
6e855cd4 AS |
8884 | |
8885 | /* | |
8886 | * Let userspace know that this PMU supports address range filtering: | |
8887 | */ | |
8888 | static ssize_t nr_addr_filters_show(struct device *dev, | |
8889 | struct device_attribute *attr, | |
8890 | char *page) | |
8891 | { | |
8892 | struct pmu *pmu = dev_get_drvdata(dev); | |
8893 | ||
8894 | return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters); | |
8895 | } | |
8896 | DEVICE_ATTR_RO(nr_addr_filters); | |
8897 | ||
2e80a82a | 8898 | static struct idr pmu_idr; |
d6d020e9 | 8899 | |
abe43400 PZ |
8900 | static ssize_t |
8901 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
8902 | { | |
8903 | struct pmu *pmu = dev_get_drvdata(dev); | |
8904 | ||
8905 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
8906 | } | |
90826ca7 | 8907 | static DEVICE_ATTR_RO(type); |
abe43400 | 8908 | |
62b85639 SE |
8909 | static ssize_t |
8910 | perf_event_mux_interval_ms_show(struct device *dev, | |
8911 | struct device_attribute *attr, | |
8912 | char *page) | |
8913 | { | |
8914 | struct pmu *pmu = dev_get_drvdata(dev); | |
8915 | ||
8916 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
8917 | } | |
8918 | ||
272325c4 PZ |
8919 | static DEFINE_MUTEX(mux_interval_mutex); |
8920 | ||
62b85639 SE |
8921 | static ssize_t |
8922 | perf_event_mux_interval_ms_store(struct device *dev, | |
8923 | struct device_attribute *attr, | |
8924 | const char *buf, size_t count) | |
8925 | { | |
8926 | struct pmu *pmu = dev_get_drvdata(dev); | |
8927 | int timer, cpu, ret; | |
8928 | ||
8929 | ret = kstrtoint(buf, 0, &timer); | |
8930 | if (ret) | |
8931 | return ret; | |
8932 | ||
8933 | if (timer < 1) | |
8934 | return -EINVAL; | |
8935 | ||
8936 | /* same value, noting to do */ | |
8937 | if (timer == pmu->hrtimer_interval_ms) | |
8938 | return count; | |
8939 | ||
272325c4 | 8940 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
8941 | pmu->hrtimer_interval_ms = timer; |
8942 | ||
8943 | /* update all cpuctx for this PMU */ | |
a63fbed7 | 8944 | cpus_read_lock(); |
272325c4 | 8945 | for_each_online_cpu(cpu) { |
62b85639 SE |
8946 | struct perf_cpu_context *cpuctx; |
8947 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
8948 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
8949 | ||
272325c4 PZ |
8950 | cpu_function_call(cpu, |
8951 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 8952 | } |
a63fbed7 | 8953 | cpus_read_unlock(); |
272325c4 | 8954 | mutex_unlock(&mux_interval_mutex); |
62b85639 SE |
8955 | |
8956 | return count; | |
8957 | } | |
90826ca7 | 8958 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 8959 | |
90826ca7 GKH |
8960 | static struct attribute *pmu_dev_attrs[] = { |
8961 | &dev_attr_type.attr, | |
8962 | &dev_attr_perf_event_mux_interval_ms.attr, | |
8963 | NULL, | |
abe43400 | 8964 | }; |
90826ca7 | 8965 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
8966 | |
8967 | static int pmu_bus_running; | |
8968 | static struct bus_type pmu_bus = { | |
8969 | .name = "event_source", | |
90826ca7 | 8970 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
8971 | }; |
8972 | ||
8973 | static void pmu_dev_release(struct device *dev) | |
8974 | { | |
8975 | kfree(dev); | |
8976 | } | |
8977 | ||
8978 | static int pmu_dev_alloc(struct pmu *pmu) | |
8979 | { | |
8980 | int ret = -ENOMEM; | |
8981 | ||
8982 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
8983 | if (!pmu->dev) | |
8984 | goto out; | |
8985 | ||
0c9d42ed | 8986 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
8987 | device_initialize(pmu->dev); |
8988 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
8989 | if (ret) | |
8990 | goto free_dev; | |
8991 | ||
8992 | dev_set_drvdata(pmu->dev, pmu); | |
8993 | pmu->dev->bus = &pmu_bus; | |
8994 | pmu->dev->release = pmu_dev_release; | |
8995 | ret = device_add(pmu->dev); | |
8996 | if (ret) | |
8997 | goto free_dev; | |
8998 | ||
6e855cd4 AS |
8999 | /* For PMUs with address filters, throw in an extra attribute: */ |
9000 | if (pmu->nr_addr_filters) | |
9001 | ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters); | |
9002 | ||
9003 | if (ret) | |
9004 | goto del_dev; | |
9005 | ||
abe43400 PZ |
9006 | out: |
9007 | return ret; | |
9008 | ||
6e855cd4 AS |
9009 | del_dev: |
9010 | device_del(pmu->dev); | |
9011 | ||
abe43400 PZ |
9012 | free_dev: |
9013 | put_device(pmu->dev); | |
9014 | goto out; | |
9015 | } | |
9016 | ||
547e9fd7 | 9017 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 9018 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 9019 | |
03d8e80b | 9020 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 9021 | { |
108b02cf | 9022 | int cpu, ret; |
24f1e32c | 9023 | |
b0a873eb | 9024 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
9025 | ret = -ENOMEM; |
9026 | pmu->pmu_disable_count = alloc_percpu(int); | |
9027 | if (!pmu->pmu_disable_count) | |
9028 | goto unlock; | |
f29ac756 | 9029 | |
2e80a82a PZ |
9030 | pmu->type = -1; |
9031 | if (!name) | |
9032 | goto skip_type; | |
9033 | pmu->name = name; | |
9034 | ||
9035 | if (type < 0) { | |
0e9c3be2 TH |
9036 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
9037 | if (type < 0) { | |
9038 | ret = type; | |
2e80a82a PZ |
9039 | goto free_pdc; |
9040 | } | |
9041 | } | |
9042 | pmu->type = type; | |
9043 | ||
abe43400 PZ |
9044 | if (pmu_bus_running) { |
9045 | ret = pmu_dev_alloc(pmu); | |
9046 | if (ret) | |
9047 | goto free_idr; | |
9048 | } | |
9049 | ||
2e80a82a | 9050 | skip_type: |
26657848 PZ |
9051 | if (pmu->task_ctx_nr == perf_hw_context) { |
9052 | static int hw_context_taken = 0; | |
9053 | ||
5101ef20 MR |
9054 | /* |
9055 | * Other than systems with heterogeneous CPUs, it never makes | |
9056 | * sense for two PMUs to share perf_hw_context. PMUs which are | |
9057 | * uncore must use perf_invalid_context. | |
9058 | */ | |
9059 | if (WARN_ON_ONCE(hw_context_taken && | |
9060 | !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS))) | |
26657848 PZ |
9061 | pmu->task_ctx_nr = perf_invalid_context; |
9062 | ||
9063 | hw_context_taken = 1; | |
9064 | } | |
9065 | ||
8dc85d54 PZ |
9066 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
9067 | if (pmu->pmu_cpu_context) | |
9068 | goto got_cpu_context; | |
f29ac756 | 9069 | |
c4814202 | 9070 | ret = -ENOMEM; |
108b02cf PZ |
9071 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
9072 | if (!pmu->pmu_cpu_context) | |
abe43400 | 9073 | goto free_dev; |
f344011c | 9074 | |
108b02cf PZ |
9075 | for_each_possible_cpu(cpu) { |
9076 | struct perf_cpu_context *cpuctx; | |
9077 | ||
9078 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 9079 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 9080 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 9081 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 9082 | cpuctx->ctx.pmu = pmu; |
a63fbed7 | 9083 | cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask); |
9e630205 | 9084 | |
272325c4 | 9085 | __perf_mux_hrtimer_init(cpuctx, cpu); |
108b02cf | 9086 | } |
76e1d904 | 9087 | |
8dc85d54 | 9088 | got_cpu_context: |
ad5133b7 PZ |
9089 | if (!pmu->start_txn) { |
9090 | if (pmu->pmu_enable) { | |
9091 | /* | |
9092 | * If we have pmu_enable/pmu_disable calls, install | |
9093 | * transaction stubs that use that to try and batch | |
9094 | * hardware accesses. | |
9095 | */ | |
9096 | pmu->start_txn = perf_pmu_start_txn; | |
9097 | pmu->commit_txn = perf_pmu_commit_txn; | |
9098 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
9099 | } else { | |
fbbe0701 | 9100 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
9101 | pmu->commit_txn = perf_pmu_nop_int; |
9102 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 9103 | } |
5c92d124 | 9104 | } |
15dbf27c | 9105 | |
ad5133b7 PZ |
9106 | if (!pmu->pmu_enable) { |
9107 | pmu->pmu_enable = perf_pmu_nop_void; | |
9108 | pmu->pmu_disable = perf_pmu_nop_void; | |
9109 | } | |
9110 | ||
35edc2a5 PZ |
9111 | if (!pmu->event_idx) |
9112 | pmu->event_idx = perf_event_idx_default; | |
9113 | ||
b0a873eb | 9114 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 9115 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
9116 | ret = 0; |
9117 | unlock: | |
b0a873eb PZ |
9118 | mutex_unlock(&pmus_lock); |
9119 | ||
33696fc0 | 9120 | return ret; |
108b02cf | 9121 | |
abe43400 PZ |
9122 | free_dev: |
9123 | device_del(pmu->dev); | |
9124 | put_device(pmu->dev); | |
9125 | ||
2e80a82a PZ |
9126 | free_idr: |
9127 | if (pmu->type >= PERF_TYPE_MAX) | |
9128 | idr_remove(&pmu_idr, pmu->type); | |
9129 | ||
108b02cf PZ |
9130 | free_pdc: |
9131 | free_percpu(pmu->pmu_disable_count); | |
9132 | goto unlock; | |
f29ac756 | 9133 | } |
c464c76e | 9134 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 9135 | |
b0a873eb | 9136 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 9137 | { |
0933840a JO |
9138 | int remove_device; |
9139 | ||
b0a873eb | 9140 | mutex_lock(&pmus_lock); |
0933840a | 9141 | remove_device = pmu_bus_running; |
b0a873eb PZ |
9142 | list_del_rcu(&pmu->entry); |
9143 | mutex_unlock(&pmus_lock); | |
5c92d124 | 9144 | |
0475f9ea | 9145 | /* |
cde8e884 PZ |
9146 | * We dereference the pmu list under both SRCU and regular RCU, so |
9147 | * synchronize against both of those. | |
0475f9ea | 9148 | */ |
b0a873eb | 9149 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 9150 | synchronize_rcu(); |
d6d020e9 | 9151 | |
33696fc0 | 9152 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
9153 | if (pmu->type >= PERF_TYPE_MAX) |
9154 | idr_remove(&pmu_idr, pmu->type); | |
0933840a JO |
9155 | if (remove_device) { |
9156 | if (pmu->nr_addr_filters) | |
9157 | device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); | |
9158 | device_del(pmu->dev); | |
9159 | put_device(pmu->dev); | |
9160 | } | |
51676957 | 9161 | free_pmu_context(pmu); |
b0a873eb | 9162 | } |
c464c76e | 9163 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 9164 | |
cc34b98b MR |
9165 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
9166 | { | |
ccd41c86 | 9167 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
9168 | int ret; |
9169 | ||
9170 | if (!try_module_get(pmu->module)) | |
9171 | return -ENODEV; | |
ccd41c86 PZ |
9172 | |
9173 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
9174 | /* |
9175 | * This ctx->mutex can nest when we're called through | |
9176 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
9177 | */ | |
9178 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
9179 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
9180 | BUG_ON(!ctx); |
9181 | } | |
9182 | ||
cc34b98b MR |
9183 | event->pmu = pmu; |
9184 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
9185 | |
9186 | if (ctx) | |
9187 | perf_event_ctx_unlock(event->group_leader, ctx); | |
9188 | ||
cc34b98b MR |
9189 | if (ret) |
9190 | module_put(pmu->module); | |
9191 | ||
9192 | return ret; | |
9193 | } | |
9194 | ||
18ab2cd3 | 9195 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb | 9196 | { |
85c617ab | 9197 | struct pmu *pmu; |
b0a873eb | 9198 | int idx; |
940c5b29 | 9199 | int ret; |
b0a873eb PZ |
9200 | |
9201 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a | 9202 | |
40999312 KL |
9203 | /* Try parent's PMU first: */ |
9204 | if (event->parent && event->parent->pmu) { | |
9205 | pmu = event->parent->pmu; | |
9206 | ret = perf_try_init_event(pmu, event); | |
9207 | if (!ret) | |
9208 | goto unlock; | |
9209 | } | |
9210 | ||
2e80a82a PZ |
9211 | rcu_read_lock(); |
9212 | pmu = idr_find(&pmu_idr, event->attr.type); | |
9213 | rcu_read_unlock(); | |
940c5b29 | 9214 | if (pmu) { |
cc34b98b | 9215 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
9216 | if (ret) |
9217 | pmu = ERR_PTR(ret); | |
2e80a82a | 9218 | goto unlock; |
940c5b29 | 9219 | } |
2e80a82a | 9220 | |
b0a873eb | 9221 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 9222 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 9223 | if (!ret) |
e5f4d339 | 9224 | goto unlock; |
76e1d904 | 9225 | |
b0a873eb PZ |
9226 | if (ret != -ENOENT) { |
9227 | pmu = ERR_PTR(ret); | |
e5f4d339 | 9228 | goto unlock; |
f344011c | 9229 | } |
5c92d124 | 9230 | } |
e5f4d339 PZ |
9231 | pmu = ERR_PTR(-ENOENT); |
9232 | unlock: | |
b0a873eb | 9233 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 9234 | |
4aeb0b42 | 9235 | return pmu; |
5c92d124 IM |
9236 | } |
9237 | ||
f2fb6bef KL |
9238 | static void attach_sb_event(struct perf_event *event) |
9239 | { | |
9240 | struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu); | |
9241 | ||
9242 | raw_spin_lock(&pel->lock); | |
9243 | list_add_rcu(&event->sb_list, &pel->list); | |
9244 | raw_spin_unlock(&pel->lock); | |
9245 | } | |
9246 | ||
aab5b71e PZ |
9247 | /* |
9248 | * We keep a list of all !task (and therefore per-cpu) events | |
9249 | * that need to receive side-band records. | |
9250 | * | |
9251 | * This avoids having to scan all the various PMU per-cpu contexts | |
9252 | * looking for them. | |
9253 | */ | |
f2fb6bef KL |
9254 | static void account_pmu_sb_event(struct perf_event *event) |
9255 | { | |
a4f144eb | 9256 | if (is_sb_event(event)) |
f2fb6bef KL |
9257 | attach_sb_event(event); |
9258 | } | |
9259 | ||
4beb31f3 FW |
9260 | static void account_event_cpu(struct perf_event *event, int cpu) |
9261 | { | |
9262 | if (event->parent) | |
9263 | return; | |
9264 | ||
4beb31f3 FW |
9265 | if (is_cgroup_event(event)) |
9266 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
9267 | } | |
9268 | ||
555e0c1e FW |
9269 | /* Freq events need the tick to stay alive (see perf_event_task_tick). */ |
9270 | static void account_freq_event_nohz(void) | |
9271 | { | |
9272 | #ifdef CONFIG_NO_HZ_FULL | |
9273 | /* Lock so we don't race with concurrent unaccount */ | |
9274 | spin_lock(&nr_freq_lock); | |
9275 | if (atomic_inc_return(&nr_freq_events) == 1) | |
9276 | tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS); | |
9277 | spin_unlock(&nr_freq_lock); | |
9278 | #endif | |
9279 | } | |
9280 | ||
9281 | static void account_freq_event(void) | |
9282 | { | |
9283 | if (tick_nohz_full_enabled()) | |
9284 | account_freq_event_nohz(); | |
9285 | else | |
9286 | atomic_inc(&nr_freq_events); | |
9287 | } | |
9288 | ||
9289 | ||
766d6c07 FW |
9290 | static void account_event(struct perf_event *event) |
9291 | { | |
25432ae9 PZ |
9292 | bool inc = false; |
9293 | ||
4beb31f3 FW |
9294 | if (event->parent) |
9295 | return; | |
9296 | ||
766d6c07 | 9297 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 9298 | inc = true; |
766d6c07 FW |
9299 | if (event->attr.mmap || event->attr.mmap_data) |
9300 | atomic_inc(&nr_mmap_events); | |
9301 | if (event->attr.comm) | |
9302 | atomic_inc(&nr_comm_events); | |
e4222673 HB |
9303 | if (event->attr.namespaces) |
9304 | atomic_inc(&nr_namespaces_events); | |
766d6c07 FW |
9305 | if (event->attr.task) |
9306 | atomic_inc(&nr_task_events); | |
555e0c1e FW |
9307 | if (event->attr.freq) |
9308 | account_freq_event(); | |
45ac1403 AH |
9309 | if (event->attr.context_switch) { |
9310 | atomic_inc(&nr_switch_events); | |
25432ae9 | 9311 | inc = true; |
45ac1403 | 9312 | } |
4beb31f3 | 9313 | if (has_branch_stack(event)) |
25432ae9 | 9314 | inc = true; |
4beb31f3 | 9315 | if (is_cgroup_event(event)) |
25432ae9 PZ |
9316 | inc = true; |
9317 | ||
9107c89e PZ |
9318 | if (inc) { |
9319 | if (atomic_inc_not_zero(&perf_sched_count)) | |
9320 | goto enabled; | |
9321 | ||
9322 | mutex_lock(&perf_sched_mutex); | |
9323 | if (!atomic_read(&perf_sched_count)) { | |
9324 | static_branch_enable(&perf_sched_events); | |
9325 | /* | |
9326 | * Guarantee that all CPUs observe they key change and | |
9327 | * call the perf scheduling hooks before proceeding to | |
9328 | * install events that need them. | |
9329 | */ | |
9330 | synchronize_sched(); | |
9331 | } | |
9332 | /* | |
9333 | * Now that we have waited for the sync_sched(), allow further | |
9334 | * increments to by-pass the mutex. | |
9335 | */ | |
9336 | atomic_inc(&perf_sched_count); | |
9337 | mutex_unlock(&perf_sched_mutex); | |
9338 | } | |
9339 | enabled: | |
4beb31f3 FW |
9340 | |
9341 | account_event_cpu(event, event->cpu); | |
f2fb6bef KL |
9342 | |
9343 | account_pmu_sb_event(event); | |
766d6c07 FW |
9344 | } |
9345 | ||
0793a61d | 9346 | /* |
cdd6c482 | 9347 | * Allocate and initialize a event structure |
0793a61d | 9348 | */ |
cdd6c482 | 9349 | static struct perf_event * |
c3f00c70 | 9350 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
9351 | struct task_struct *task, |
9352 | struct perf_event *group_leader, | |
9353 | struct perf_event *parent_event, | |
4dc0da86 | 9354 | perf_overflow_handler_t overflow_handler, |
79dff51e | 9355 | void *context, int cgroup_fd) |
0793a61d | 9356 | { |
51b0fe39 | 9357 | struct pmu *pmu; |
cdd6c482 IM |
9358 | struct perf_event *event; |
9359 | struct hw_perf_event *hwc; | |
90983b16 | 9360 | long err = -EINVAL; |
0793a61d | 9361 | |
66832eb4 ON |
9362 | if ((unsigned)cpu >= nr_cpu_ids) { |
9363 | if (!task || cpu != -1) | |
9364 | return ERR_PTR(-EINVAL); | |
9365 | } | |
9366 | ||
c3f00c70 | 9367 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 9368 | if (!event) |
d5d2bc0d | 9369 | return ERR_PTR(-ENOMEM); |
0793a61d | 9370 | |
04289bb9 | 9371 | /* |
cdd6c482 | 9372 | * Single events are their own group leaders, with an |
04289bb9 IM |
9373 | * empty sibling list: |
9374 | */ | |
9375 | if (!group_leader) | |
cdd6c482 | 9376 | group_leader = event; |
04289bb9 | 9377 | |
cdd6c482 IM |
9378 | mutex_init(&event->child_mutex); |
9379 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 9380 | |
cdd6c482 IM |
9381 | INIT_LIST_HEAD(&event->group_entry); |
9382 | INIT_LIST_HEAD(&event->event_entry); | |
9383 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 9384 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 9385 | INIT_LIST_HEAD(&event->active_entry); |
375637bc | 9386 | INIT_LIST_HEAD(&event->addr_filters.list); |
f3ae75de SE |
9387 | INIT_HLIST_NODE(&event->hlist_entry); |
9388 | ||
10c6db11 | 9389 | |
cdd6c482 | 9390 | init_waitqueue_head(&event->waitq); |
e360adbe | 9391 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 9392 | |
cdd6c482 | 9393 | mutex_init(&event->mmap_mutex); |
375637bc | 9394 | raw_spin_lock_init(&event->addr_filters.lock); |
7b732a75 | 9395 | |
a6fa941d | 9396 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
9397 | event->cpu = cpu; |
9398 | event->attr = *attr; | |
9399 | event->group_leader = group_leader; | |
9400 | event->pmu = NULL; | |
cdd6c482 | 9401 | event->oncpu = -1; |
a96bbc16 | 9402 | |
cdd6c482 | 9403 | event->parent = parent_event; |
b84fbc9f | 9404 | |
17cf22c3 | 9405 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 9406 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 9407 | |
cdd6c482 | 9408 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 9409 | |
d580ff86 PZ |
9410 | if (task) { |
9411 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 9412 | /* |
50f16a8b PZ |
9413 | * XXX pmu::event_init needs to know what task to account to |
9414 | * and we cannot use the ctx information because we need the | |
9415 | * pmu before we get a ctx. | |
d580ff86 | 9416 | */ |
50f16a8b | 9417 | event->hw.target = task; |
d580ff86 PZ |
9418 | } |
9419 | ||
34f43927 PZ |
9420 | event->clock = &local_clock; |
9421 | if (parent_event) | |
9422 | event->clock = parent_event->clock; | |
9423 | ||
4dc0da86 | 9424 | if (!overflow_handler && parent_event) { |
b326e956 | 9425 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 | 9426 | context = parent_event->overflow_handler_context; |
f1e4ba5b | 9427 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING) |
aa6a5f3c AS |
9428 | if (overflow_handler == bpf_overflow_handler) { |
9429 | struct bpf_prog *prog = bpf_prog_inc(parent_event->prog); | |
9430 | ||
9431 | if (IS_ERR(prog)) { | |
9432 | err = PTR_ERR(prog); | |
9433 | goto err_ns; | |
9434 | } | |
9435 | event->prog = prog; | |
9436 | event->orig_overflow_handler = | |
9437 | parent_event->orig_overflow_handler; | |
9438 | } | |
9439 | #endif | |
4dc0da86 | 9440 | } |
66832eb4 | 9441 | |
1879445d WN |
9442 | if (overflow_handler) { |
9443 | event->overflow_handler = overflow_handler; | |
9444 | event->overflow_handler_context = context; | |
9ecda41a WN |
9445 | } else if (is_write_backward(event)){ |
9446 | event->overflow_handler = perf_event_output_backward; | |
9447 | event->overflow_handler_context = NULL; | |
1879445d | 9448 | } else { |
9ecda41a | 9449 | event->overflow_handler = perf_event_output_forward; |
1879445d WN |
9450 | event->overflow_handler_context = NULL; |
9451 | } | |
97eaf530 | 9452 | |
0231bb53 | 9453 | perf_event__state_init(event); |
a86ed508 | 9454 | |
4aeb0b42 | 9455 | pmu = NULL; |
b8e83514 | 9456 | |
cdd6c482 | 9457 | hwc = &event->hw; |
bd2b5b12 | 9458 | hwc->sample_period = attr->sample_period; |
0d48696f | 9459 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 9460 | hwc->sample_period = 1; |
eced1dfc | 9461 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 9462 | |
e7850595 | 9463 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 9464 | |
2023b359 | 9465 | /* |
ba5213ae PZ |
9466 | * We currently do not support PERF_SAMPLE_READ on inherited events. |
9467 | * See perf_output_read(). | |
2023b359 | 9468 | */ |
ba5213ae | 9469 | if (attr->inherit && (attr->sample_type & PERF_SAMPLE_READ)) |
90983b16 | 9470 | goto err_ns; |
a46a2300 YZ |
9471 | |
9472 | if (!has_branch_stack(event)) | |
9473 | event->attr.branch_sample_type = 0; | |
2023b359 | 9474 | |
79dff51e MF |
9475 | if (cgroup_fd != -1) { |
9476 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
9477 | if (err) | |
9478 | goto err_ns; | |
9479 | } | |
9480 | ||
b0a873eb | 9481 | pmu = perf_init_event(event); |
85c617ab | 9482 | if (IS_ERR(pmu)) { |
4aeb0b42 | 9483 | err = PTR_ERR(pmu); |
90983b16 | 9484 | goto err_ns; |
621a01ea | 9485 | } |
d5d2bc0d | 9486 | |
bed5b25a AS |
9487 | err = exclusive_event_init(event); |
9488 | if (err) | |
9489 | goto err_pmu; | |
9490 | ||
375637bc AS |
9491 | if (has_addr_filter(event)) { |
9492 | event->addr_filters_offs = kcalloc(pmu->nr_addr_filters, | |
9493 | sizeof(unsigned long), | |
9494 | GFP_KERNEL); | |
36cc2b92 DC |
9495 | if (!event->addr_filters_offs) { |
9496 | err = -ENOMEM; | |
375637bc | 9497 | goto err_per_task; |
36cc2b92 | 9498 | } |
375637bc AS |
9499 | |
9500 | /* force hw sync on the address filters */ | |
9501 | event->addr_filters_gen = 1; | |
9502 | } | |
9503 | ||
cdd6c482 | 9504 | if (!event->parent) { |
927c7a9e | 9505 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
97c79a38 | 9506 | err = get_callchain_buffers(attr->sample_max_stack); |
90983b16 | 9507 | if (err) |
375637bc | 9508 | goto err_addr_filters; |
d010b332 | 9509 | } |
f344011c | 9510 | } |
9ee318a7 | 9511 | |
927a5570 AS |
9512 | /* symmetric to unaccount_event() in _free_event() */ |
9513 | account_event(event); | |
9514 | ||
cdd6c482 | 9515 | return event; |
90983b16 | 9516 | |
375637bc AS |
9517 | err_addr_filters: |
9518 | kfree(event->addr_filters_offs); | |
9519 | ||
bed5b25a AS |
9520 | err_per_task: |
9521 | exclusive_event_destroy(event); | |
9522 | ||
90983b16 FW |
9523 | err_pmu: |
9524 | if (event->destroy) | |
9525 | event->destroy(event); | |
c464c76e | 9526 | module_put(pmu->module); |
90983b16 | 9527 | err_ns: |
79dff51e MF |
9528 | if (is_cgroup_event(event)) |
9529 | perf_detach_cgroup(event); | |
90983b16 FW |
9530 | if (event->ns) |
9531 | put_pid_ns(event->ns); | |
9532 | kfree(event); | |
9533 | ||
9534 | return ERR_PTR(err); | |
0793a61d TG |
9535 | } |
9536 | ||
cdd6c482 IM |
9537 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
9538 | struct perf_event_attr *attr) | |
974802ea | 9539 | { |
974802ea | 9540 | u32 size; |
cdf8073d | 9541 | int ret; |
974802ea PZ |
9542 | |
9543 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
9544 | return -EFAULT; | |
9545 | ||
9546 | /* | |
9547 | * zero the full structure, so that a short copy will be nice. | |
9548 | */ | |
9549 | memset(attr, 0, sizeof(*attr)); | |
9550 | ||
9551 | ret = get_user(size, &uattr->size); | |
9552 | if (ret) | |
9553 | return ret; | |
9554 | ||
9555 | if (size > PAGE_SIZE) /* silly large */ | |
9556 | goto err_size; | |
9557 | ||
9558 | if (!size) /* abi compat */ | |
9559 | size = PERF_ATTR_SIZE_VER0; | |
9560 | ||
9561 | if (size < PERF_ATTR_SIZE_VER0) | |
9562 | goto err_size; | |
9563 | ||
9564 | /* | |
9565 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
9566 | * ensure all the unknown bits are 0 - i.e. new |
9567 | * user-space does not rely on any kernel feature | |
9568 | * extensions we dont know about yet. | |
974802ea PZ |
9569 | */ |
9570 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
9571 | unsigned char __user *addr; |
9572 | unsigned char __user *end; | |
9573 | unsigned char val; | |
974802ea | 9574 | |
cdf8073d IS |
9575 | addr = (void __user *)uattr + sizeof(*attr); |
9576 | end = (void __user *)uattr + size; | |
974802ea | 9577 | |
cdf8073d | 9578 | for (; addr < end; addr++) { |
974802ea PZ |
9579 | ret = get_user(val, addr); |
9580 | if (ret) | |
9581 | return ret; | |
9582 | if (val) | |
9583 | goto err_size; | |
9584 | } | |
b3e62e35 | 9585 | size = sizeof(*attr); |
974802ea PZ |
9586 | } |
9587 | ||
9588 | ret = copy_from_user(attr, uattr, size); | |
9589 | if (ret) | |
9590 | return -EFAULT; | |
9591 | ||
cd757645 | 9592 | if (attr->__reserved_1) |
974802ea PZ |
9593 | return -EINVAL; |
9594 | ||
9595 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
9596 | return -EINVAL; | |
9597 | ||
9598 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
9599 | return -EINVAL; | |
9600 | ||
bce38cd5 SE |
9601 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
9602 | u64 mask = attr->branch_sample_type; | |
9603 | ||
9604 | /* only using defined bits */ | |
9605 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
9606 | return -EINVAL; | |
9607 | ||
9608 | /* at least one branch bit must be set */ | |
9609 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
9610 | return -EINVAL; | |
9611 | ||
bce38cd5 SE |
9612 | /* propagate priv level, when not set for branch */ |
9613 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
9614 | ||
9615 | /* exclude_kernel checked on syscall entry */ | |
9616 | if (!attr->exclude_kernel) | |
9617 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
9618 | ||
9619 | if (!attr->exclude_user) | |
9620 | mask |= PERF_SAMPLE_BRANCH_USER; | |
9621 | ||
9622 | if (!attr->exclude_hv) | |
9623 | mask |= PERF_SAMPLE_BRANCH_HV; | |
9624 | /* | |
9625 | * adjust user setting (for HW filter setup) | |
9626 | */ | |
9627 | attr->branch_sample_type = mask; | |
9628 | } | |
e712209a SE |
9629 | /* privileged levels capture (kernel, hv): check permissions */ |
9630 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
9631 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
9632 | return -EACCES; | |
bce38cd5 | 9633 | } |
4018994f | 9634 | |
c5ebcedb | 9635 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 9636 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
9637 | if (ret) |
9638 | return ret; | |
9639 | } | |
9640 | ||
9641 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
9642 | if (!arch_perf_have_user_stack_dump()) | |
9643 | return -ENOSYS; | |
9644 | ||
9645 | /* | |
9646 | * We have __u32 type for the size, but so far | |
9647 | * we can only use __u16 as maximum due to the | |
9648 | * __u16 sample size limit. | |
9649 | */ | |
9650 | if (attr->sample_stack_user >= USHRT_MAX) | |
9651 | ret = -EINVAL; | |
9652 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
9653 | ret = -EINVAL; | |
9654 | } | |
4018994f | 9655 | |
60e2364e SE |
9656 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
9657 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
9658 | out: |
9659 | return ret; | |
9660 | ||
9661 | err_size: | |
9662 | put_user(sizeof(*attr), &uattr->size); | |
9663 | ret = -E2BIG; | |
9664 | goto out; | |
9665 | } | |
9666 | ||
ac9721f3 PZ |
9667 | static int |
9668 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 9669 | { |
b69cf536 | 9670 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
9671 | int ret = -EINVAL; |
9672 | ||
ac9721f3 | 9673 | if (!output_event) |
a4be7c27 PZ |
9674 | goto set; |
9675 | ||
ac9721f3 PZ |
9676 | /* don't allow circular references */ |
9677 | if (event == output_event) | |
a4be7c27 PZ |
9678 | goto out; |
9679 | ||
0f139300 PZ |
9680 | /* |
9681 | * Don't allow cross-cpu buffers | |
9682 | */ | |
9683 | if (output_event->cpu != event->cpu) | |
9684 | goto out; | |
9685 | ||
9686 | /* | |
76369139 | 9687 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
9688 | */ |
9689 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
9690 | goto out; | |
9691 | ||
34f43927 PZ |
9692 | /* |
9693 | * Mixing clocks in the same buffer is trouble you don't need. | |
9694 | */ | |
9695 | if (output_event->clock != event->clock) | |
9696 | goto out; | |
9697 | ||
9ecda41a WN |
9698 | /* |
9699 | * Either writing ring buffer from beginning or from end. | |
9700 | * Mixing is not allowed. | |
9701 | */ | |
9702 | if (is_write_backward(output_event) != is_write_backward(event)) | |
9703 | goto out; | |
9704 | ||
45bfb2e5 PZ |
9705 | /* |
9706 | * If both events generate aux data, they must be on the same PMU | |
9707 | */ | |
9708 | if (has_aux(event) && has_aux(output_event) && | |
9709 | event->pmu != output_event->pmu) | |
9710 | goto out; | |
9711 | ||
a4be7c27 | 9712 | set: |
cdd6c482 | 9713 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
9714 | /* Can't redirect output if we've got an active mmap() */ |
9715 | if (atomic_read(&event->mmap_count)) | |
9716 | goto unlock; | |
a4be7c27 | 9717 | |
ac9721f3 | 9718 | if (output_event) { |
76369139 FW |
9719 | /* get the rb we want to redirect to */ |
9720 | rb = ring_buffer_get(output_event); | |
9721 | if (!rb) | |
ac9721f3 | 9722 | goto unlock; |
a4be7c27 PZ |
9723 | } |
9724 | ||
b69cf536 | 9725 | ring_buffer_attach(event, rb); |
9bb5d40c | 9726 | |
a4be7c27 | 9727 | ret = 0; |
ac9721f3 PZ |
9728 | unlock: |
9729 | mutex_unlock(&event->mmap_mutex); | |
9730 | ||
a4be7c27 | 9731 | out: |
a4be7c27 PZ |
9732 | return ret; |
9733 | } | |
9734 | ||
f63a8daa PZ |
9735 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
9736 | { | |
9737 | if (b < a) | |
9738 | swap(a, b); | |
9739 | ||
9740 | mutex_lock(a); | |
9741 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
9742 | } | |
9743 | ||
34f43927 PZ |
9744 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
9745 | { | |
9746 | bool nmi_safe = false; | |
9747 | ||
9748 | switch (clk_id) { | |
9749 | case CLOCK_MONOTONIC: | |
9750 | event->clock = &ktime_get_mono_fast_ns; | |
9751 | nmi_safe = true; | |
9752 | break; | |
9753 | ||
9754 | case CLOCK_MONOTONIC_RAW: | |
9755 | event->clock = &ktime_get_raw_fast_ns; | |
9756 | nmi_safe = true; | |
9757 | break; | |
9758 | ||
9759 | case CLOCK_REALTIME: | |
9760 | event->clock = &ktime_get_real_ns; | |
9761 | break; | |
9762 | ||
9763 | case CLOCK_BOOTTIME: | |
9764 | event->clock = &ktime_get_boot_ns; | |
9765 | break; | |
9766 | ||
9767 | case CLOCK_TAI: | |
9768 | event->clock = &ktime_get_tai_ns; | |
9769 | break; | |
9770 | ||
9771 | default: | |
9772 | return -EINVAL; | |
9773 | } | |
9774 | ||
9775 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
9776 | return -EINVAL; | |
9777 | ||
9778 | return 0; | |
9779 | } | |
9780 | ||
321027c1 PZ |
9781 | /* |
9782 | * Variation on perf_event_ctx_lock_nested(), except we take two context | |
9783 | * mutexes. | |
9784 | */ | |
9785 | static struct perf_event_context * | |
9786 | __perf_event_ctx_lock_double(struct perf_event *group_leader, | |
9787 | struct perf_event_context *ctx) | |
9788 | { | |
9789 | struct perf_event_context *gctx; | |
9790 | ||
9791 | again: | |
9792 | rcu_read_lock(); | |
9793 | gctx = READ_ONCE(group_leader->ctx); | |
9794 | if (!atomic_inc_not_zero(&gctx->refcount)) { | |
9795 | rcu_read_unlock(); | |
9796 | goto again; | |
9797 | } | |
9798 | rcu_read_unlock(); | |
9799 | ||
9800 | mutex_lock_double(&gctx->mutex, &ctx->mutex); | |
9801 | ||
9802 | if (group_leader->ctx != gctx) { | |
9803 | mutex_unlock(&ctx->mutex); | |
9804 | mutex_unlock(&gctx->mutex); | |
9805 | put_ctx(gctx); | |
9806 | goto again; | |
9807 | } | |
9808 | ||
9809 | return gctx; | |
9810 | } | |
9811 | ||
0793a61d | 9812 | /** |
cdd6c482 | 9813 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 9814 | * |
cdd6c482 | 9815 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 9816 | * @pid: target pid |
9f66a381 | 9817 | * @cpu: target cpu |
cdd6c482 | 9818 | * @group_fd: group leader event fd |
0793a61d | 9819 | */ |
cdd6c482 IM |
9820 | SYSCALL_DEFINE5(perf_event_open, |
9821 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 9822 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 9823 | { |
b04243ef PZ |
9824 | struct perf_event *group_leader = NULL, *output_event = NULL; |
9825 | struct perf_event *event, *sibling; | |
cdd6c482 | 9826 | struct perf_event_attr attr; |
f63a8daa | 9827 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 9828 | struct file *event_file = NULL; |
2903ff01 | 9829 | struct fd group = {NULL, 0}; |
38a81da2 | 9830 | struct task_struct *task = NULL; |
89a1e187 | 9831 | struct pmu *pmu; |
ea635c64 | 9832 | int event_fd; |
b04243ef | 9833 | int move_group = 0; |
dc86cabe | 9834 | int err; |
a21b0b35 | 9835 | int f_flags = O_RDWR; |
79dff51e | 9836 | int cgroup_fd = -1; |
0793a61d | 9837 | |
2743a5b0 | 9838 | /* for future expandability... */ |
e5d1367f | 9839 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
9840 | return -EINVAL; |
9841 | ||
dc86cabe IM |
9842 | err = perf_copy_attr(attr_uptr, &attr); |
9843 | if (err) | |
9844 | return err; | |
eab656ae | 9845 | |
0764771d PZ |
9846 | if (!attr.exclude_kernel) { |
9847 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
9848 | return -EACCES; | |
9849 | } | |
9850 | ||
e4222673 HB |
9851 | if (attr.namespaces) { |
9852 | if (!capable(CAP_SYS_ADMIN)) | |
9853 | return -EACCES; | |
9854 | } | |
9855 | ||
df58ab24 | 9856 | if (attr.freq) { |
cdd6c482 | 9857 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 9858 | return -EINVAL; |
0819b2e3 PZ |
9859 | } else { |
9860 | if (attr.sample_period & (1ULL << 63)) | |
9861 | return -EINVAL; | |
df58ab24 PZ |
9862 | } |
9863 | ||
97c79a38 ACM |
9864 | if (!attr.sample_max_stack) |
9865 | attr.sample_max_stack = sysctl_perf_event_max_stack; | |
9866 | ||
e5d1367f SE |
9867 | /* |
9868 | * In cgroup mode, the pid argument is used to pass the fd | |
9869 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
9870 | * designates the cpu on which to monitor threads from that | |
9871 | * cgroup. | |
9872 | */ | |
9873 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
9874 | return -EINVAL; | |
9875 | ||
a21b0b35 YD |
9876 | if (flags & PERF_FLAG_FD_CLOEXEC) |
9877 | f_flags |= O_CLOEXEC; | |
9878 | ||
9879 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
9880 | if (event_fd < 0) |
9881 | return event_fd; | |
9882 | ||
ac9721f3 | 9883 | if (group_fd != -1) { |
2903ff01 AV |
9884 | err = perf_fget_light(group_fd, &group); |
9885 | if (err) | |
d14b12d7 | 9886 | goto err_fd; |
2903ff01 | 9887 | group_leader = group.file->private_data; |
ac9721f3 PZ |
9888 | if (flags & PERF_FLAG_FD_OUTPUT) |
9889 | output_event = group_leader; | |
9890 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
9891 | group_leader = NULL; | |
9892 | } | |
9893 | ||
e5d1367f | 9894 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
9895 | task = find_lively_task_by_vpid(pid); |
9896 | if (IS_ERR(task)) { | |
9897 | err = PTR_ERR(task); | |
9898 | goto err_group_fd; | |
9899 | } | |
9900 | } | |
9901 | ||
1f4ee503 PZ |
9902 | if (task && group_leader && |
9903 | group_leader->attr.inherit != attr.inherit) { | |
9904 | err = -EINVAL; | |
9905 | goto err_task; | |
9906 | } | |
9907 | ||
79c9ce57 PZ |
9908 | if (task) { |
9909 | err = mutex_lock_interruptible(&task->signal->cred_guard_mutex); | |
9910 | if (err) | |
e5aeee51 | 9911 | goto err_task; |
79c9ce57 PZ |
9912 | |
9913 | /* | |
9914 | * Reuse ptrace permission checks for now. | |
9915 | * | |
9916 | * We must hold cred_guard_mutex across this and any potential | |
9917 | * perf_install_in_context() call for this new event to | |
9918 | * serialize against exec() altering our credentials (and the | |
9919 | * perf_event_exit_task() that could imply). | |
9920 | */ | |
9921 | err = -EACCES; | |
9922 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) | |
9923 | goto err_cred; | |
9924 | } | |
9925 | ||
79dff51e MF |
9926 | if (flags & PERF_FLAG_PID_CGROUP) |
9927 | cgroup_fd = pid; | |
9928 | ||
4dc0da86 | 9929 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 9930 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
9931 | if (IS_ERR(event)) { |
9932 | err = PTR_ERR(event); | |
79c9ce57 | 9933 | goto err_cred; |
d14b12d7 SE |
9934 | } |
9935 | ||
53b25335 VW |
9936 | if (is_sampling_event(event)) { |
9937 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
a1396555 | 9938 | err = -EOPNOTSUPP; |
53b25335 VW |
9939 | goto err_alloc; |
9940 | } | |
9941 | } | |
9942 | ||
89a1e187 PZ |
9943 | /* |
9944 | * Special case software events and allow them to be part of | |
9945 | * any hardware group. | |
9946 | */ | |
9947 | pmu = event->pmu; | |
b04243ef | 9948 | |
34f43927 PZ |
9949 | if (attr.use_clockid) { |
9950 | err = perf_event_set_clock(event, attr.clockid); | |
9951 | if (err) | |
9952 | goto err_alloc; | |
9953 | } | |
9954 | ||
4ff6a8de DCC |
9955 | if (pmu->task_ctx_nr == perf_sw_context) |
9956 | event->event_caps |= PERF_EV_CAP_SOFTWARE; | |
9957 | ||
b04243ef PZ |
9958 | if (group_leader && |
9959 | (is_software_event(event) != is_software_event(group_leader))) { | |
9960 | if (is_software_event(event)) { | |
9961 | /* | |
9962 | * If event and group_leader are not both a software | |
9963 | * event, and event is, then group leader is not. | |
9964 | * | |
9965 | * Allow the addition of software events to !software | |
9966 | * groups, this is safe because software events never | |
9967 | * fail to schedule. | |
9968 | */ | |
9969 | pmu = group_leader->pmu; | |
9970 | } else if (is_software_event(group_leader) && | |
4ff6a8de | 9971 | (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) { |
b04243ef PZ |
9972 | /* |
9973 | * In case the group is a pure software group, and we | |
9974 | * try to add a hardware event, move the whole group to | |
9975 | * the hardware context. | |
9976 | */ | |
9977 | move_group = 1; | |
9978 | } | |
9979 | } | |
89a1e187 PZ |
9980 | |
9981 | /* | |
9982 | * Get the target context (task or percpu): | |
9983 | */ | |
4af57ef2 | 9984 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
9985 | if (IS_ERR(ctx)) { |
9986 | err = PTR_ERR(ctx); | |
c6be5a5c | 9987 | goto err_alloc; |
89a1e187 PZ |
9988 | } |
9989 | ||
bed5b25a AS |
9990 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
9991 | err = -EBUSY; | |
9992 | goto err_context; | |
9993 | } | |
9994 | ||
ccff286d | 9995 | /* |
cdd6c482 | 9996 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 9997 | */ |
ac9721f3 | 9998 | if (group_leader) { |
dc86cabe | 9999 | err = -EINVAL; |
04289bb9 | 10000 | |
04289bb9 | 10001 | /* |
ccff286d IM |
10002 | * Do not allow a recursive hierarchy (this new sibling |
10003 | * becoming part of another group-sibling): | |
10004 | */ | |
10005 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 10006 | goto err_context; |
34f43927 PZ |
10007 | |
10008 | /* All events in a group should have the same clock */ | |
10009 | if (group_leader->clock != event->clock) | |
10010 | goto err_context; | |
10011 | ||
ccff286d IM |
10012 | /* |
10013 | * Do not allow to attach to a group in a different | |
10014 | * task or CPU context: | |
04289bb9 | 10015 | */ |
b04243ef | 10016 | if (move_group) { |
c3c87e77 PZ |
10017 | /* |
10018 | * Make sure we're both on the same task, or both | |
10019 | * per-cpu events. | |
10020 | */ | |
10021 | if (group_leader->ctx->task != ctx->task) | |
10022 | goto err_context; | |
10023 | ||
10024 | /* | |
10025 | * Make sure we're both events for the same CPU; | |
10026 | * grouping events for different CPUs is broken; since | |
10027 | * you can never concurrently schedule them anyhow. | |
10028 | */ | |
10029 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
10030 | goto err_context; |
10031 | } else { | |
10032 | if (group_leader->ctx != ctx) | |
10033 | goto err_context; | |
10034 | } | |
10035 | ||
3b6f9e5c PM |
10036 | /* |
10037 | * Only a group leader can be exclusive or pinned | |
10038 | */ | |
0d48696f | 10039 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 10040 | goto err_context; |
ac9721f3 PZ |
10041 | } |
10042 | ||
10043 | if (output_event) { | |
10044 | err = perf_event_set_output(event, output_event); | |
10045 | if (err) | |
c3f00c70 | 10046 | goto err_context; |
ac9721f3 | 10047 | } |
0793a61d | 10048 | |
a21b0b35 YD |
10049 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
10050 | f_flags); | |
ea635c64 AV |
10051 | if (IS_ERR(event_file)) { |
10052 | err = PTR_ERR(event_file); | |
201c2f85 | 10053 | event_file = NULL; |
c3f00c70 | 10054 | goto err_context; |
ea635c64 | 10055 | } |
9b51f66d | 10056 | |
b04243ef | 10057 | if (move_group) { |
321027c1 PZ |
10058 | gctx = __perf_event_ctx_lock_double(group_leader, ctx); |
10059 | ||
84c4e620 PZ |
10060 | if (gctx->task == TASK_TOMBSTONE) { |
10061 | err = -ESRCH; | |
10062 | goto err_locked; | |
10063 | } | |
321027c1 PZ |
10064 | |
10065 | /* | |
10066 | * Check if we raced against another sys_perf_event_open() call | |
10067 | * moving the software group underneath us. | |
10068 | */ | |
10069 | if (!(group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) { | |
10070 | /* | |
10071 | * If someone moved the group out from under us, check | |
10072 | * if this new event wound up on the same ctx, if so | |
10073 | * its the regular !move_group case, otherwise fail. | |
10074 | */ | |
10075 | if (gctx != ctx) { | |
10076 | err = -EINVAL; | |
10077 | goto err_locked; | |
10078 | } else { | |
10079 | perf_event_ctx_unlock(group_leader, gctx); | |
10080 | move_group = 0; | |
10081 | } | |
10082 | } | |
f55fc2a5 PZ |
10083 | } else { |
10084 | mutex_lock(&ctx->mutex); | |
10085 | } | |
10086 | ||
84c4e620 PZ |
10087 | if (ctx->task == TASK_TOMBSTONE) { |
10088 | err = -ESRCH; | |
10089 | goto err_locked; | |
10090 | } | |
10091 | ||
a723968c PZ |
10092 | if (!perf_event_validate_size(event)) { |
10093 | err = -E2BIG; | |
10094 | goto err_locked; | |
10095 | } | |
10096 | ||
a63fbed7 TG |
10097 | if (!task) { |
10098 | /* | |
10099 | * Check if the @cpu we're creating an event for is online. | |
10100 | * | |
10101 | * We use the perf_cpu_context::ctx::mutex to serialize against | |
10102 | * the hotplug notifiers. See perf_event_{init,exit}_cpu(). | |
10103 | */ | |
10104 | struct perf_cpu_context *cpuctx = | |
10105 | container_of(ctx, struct perf_cpu_context, ctx); | |
10106 | ||
10107 | if (!cpuctx->online) { | |
10108 | err = -ENODEV; | |
10109 | goto err_locked; | |
10110 | } | |
10111 | } | |
10112 | ||
10113 | ||
f55fc2a5 PZ |
10114 | /* |
10115 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
10116 | * because we need to serialize with concurrent event creation. | |
10117 | */ | |
10118 | if (!exclusive_event_installable(event, ctx)) { | |
10119 | /* exclusive and group stuff are assumed mutually exclusive */ | |
10120 | WARN_ON_ONCE(move_group); | |
f63a8daa | 10121 | |
f55fc2a5 PZ |
10122 | err = -EBUSY; |
10123 | goto err_locked; | |
10124 | } | |
f63a8daa | 10125 | |
f55fc2a5 PZ |
10126 | WARN_ON_ONCE(ctx->parent_ctx); |
10127 | ||
79c9ce57 PZ |
10128 | /* |
10129 | * This is the point on no return; we cannot fail hereafter. This is | |
10130 | * where we start modifying current state. | |
10131 | */ | |
10132 | ||
f55fc2a5 | 10133 | if (move_group) { |
f63a8daa PZ |
10134 | /* |
10135 | * See perf_event_ctx_lock() for comments on the details | |
10136 | * of swizzling perf_event::ctx. | |
10137 | */ | |
45a0e07a | 10138 | perf_remove_from_context(group_leader, 0); |
279b5165 | 10139 | put_ctx(gctx); |
0231bb53 | 10140 | |
b04243ef PZ |
10141 | list_for_each_entry(sibling, &group_leader->sibling_list, |
10142 | group_entry) { | |
45a0e07a | 10143 | perf_remove_from_context(sibling, 0); |
b04243ef PZ |
10144 | put_ctx(gctx); |
10145 | } | |
b04243ef | 10146 | |
f63a8daa PZ |
10147 | /* |
10148 | * Wait for everybody to stop referencing the events through | |
10149 | * the old lists, before installing it on new lists. | |
10150 | */ | |
0cda4c02 | 10151 | synchronize_rcu(); |
f63a8daa | 10152 | |
8f95b435 PZI |
10153 | /* |
10154 | * Install the group siblings before the group leader. | |
10155 | * | |
10156 | * Because a group leader will try and install the entire group | |
10157 | * (through the sibling list, which is still in-tact), we can | |
10158 | * end up with siblings installed in the wrong context. | |
10159 | * | |
10160 | * By installing siblings first we NO-OP because they're not | |
10161 | * reachable through the group lists. | |
10162 | */ | |
b04243ef PZ |
10163 | list_for_each_entry(sibling, &group_leader->sibling_list, |
10164 | group_entry) { | |
8f95b435 | 10165 | perf_event__state_init(sibling); |
9fc81d87 | 10166 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
10167 | get_ctx(ctx); |
10168 | } | |
8f95b435 PZI |
10169 | |
10170 | /* | |
10171 | * Removing from the context ends up with disabled | |
10172 | * event. What we want here is event in the initial | |
10173 | * startup state, ready to be add into new context. | |
10174 | */ | |
10175 | perf_event__state_init(group_leader); | |
10176 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
10177 | get_ctx(ctx); | |
bed5b25a AS |
10178 | } |
10179 | ||
f73e22ab PZ |
10180 | /* |
10181 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
10182 | * that we're serialized against further additions and before | |
10183 | * perf_install_in_context() which is the point the event is active and | |
10184 | * can use these values. | |
10185 | */ | |
10186 | perf_event__header_size(event); | |
10187 | perf_event__id_header_size(event); | |
10188 | ||
78cd2c74 PZ |
10189 | event->owner = current; |
10190 | ||
e2d37cd2 | 10191 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 10192 | perf_unpin_context(ctx); |
f63a8daa | 10193 | |
f55fc2a5 | 10194 | if (move_group) |
321027c1 | 10195 | perf_event_ctx_unlock(group_leader, gctx); |
d859e29f | 10196 | mutex_unlock(&ctx->mutex); |
9b51f66d | 10197 | |
79c9ce57 PZ |
10198 | if (task) { |
10199 | mutex_unlock(&task->signal->cred_guard_mutex); | |
10200 | put_task_struct(task); | |
10201 | } | |
10202 | ||
cdd6c482 IM |
10203 | mutex_lock(¤t->perf_event_mutex); |
10204 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
10205 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 10206 | |
8a49542c PZ |
10207 | /* |
10208 | * Drop the reference on the group_event after placing the | |
10209 | * new event on the sibling_list. This ensures destruction | |
10210 | * of the group leader will find the pointer to itself in | |
10211 | * perf_group_detach(). | |
10212 | */ | |
2903ff01 | 10213 | fdput(group); |
ea635c64 AV |
10214 | fd_install(event_fd, event_file); |
10215 | return event_fd; | |
0793a61d | 10216 | |
f55fc2a5 PZ |
10217 | err_locked: |
10218 | if (move_group) | |
321027c1 | 10219 | perf_event_ctx_unlock(group_leader, gctx); |
f55fc2a5 PZ |
10220 | mutex_unlock(&ctx->mutex); |
10221 | /* err_file: */ | |
10222 | fput(event_file); | |
c3f00c70 | 10223 | err_context: |
fe4b04fa | 10224 | perf_unpin_context(ctx); |
ea635c64 | 10225 | put_ctx(ctx); |
c6be5a5c | 10226 | err_alloc: |
13005627 PZ |
10227 | /* |
10228 | * If event_file is set, the fput() above will have called ->release() | |
10229 | * and that will take care of freeing the event. | |
10230 | */ | |
10231 | if (!event_file) | |
10232 | free_event(event); | |
79c9ce57 PZ |
10233 | err_cred: |
10234 | if (task) | |
10235 | mutex_unlock(&task->signal->cred_guard_mutex); | |
1f4ee503 | 10236 | err_task: |
e7d0bc04 PZ |
10237 | if (task) |
10238 | put_task_struct(task); | |
89a1e187 | 10239 | err_group_fd: |
2903ff01 | 10240 | fdput(group); |
ea635c64 AV |
10241 | err_fd: |
10242 | put_unused_fd(event_fd); | |
dc86cabe | 10243 | return err; |
0793a61d TG |
10244 | } |
10245 | ||
fb0459d7 AV |
10246 | /** |
10247 | * perf_event_create_kernel_counter | |
10248 | * | |
10249 | * @attr: attributes of the counter to create | |
10250 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 10251 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
10252 | */ |
10253 | struct perf_event * | |
10254 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 10255 | struct task_struct *task, |
4dc0da86 AK |
10256 | perf_overflow_handler_t overflow_handler, |
10257 | void *context) | |
fb0459d7 | 10258 | { |
fb0459d7 | 10259 | struct perf_event_context *ctx; |
c3f00c70 | 10260 | struct perf_event *event; |
fb0459d7 | 10261 | int err; |
d859e29f | 10262 | |
fb0459d7 AV |
10263 | /* |
10264 | * Get the target context (task or percpu): | |
10265 | */ | |
d859e29f | 10266 | |
4dc0da86 | 10267 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 10268 | overflow_handler, context, -1); |
c3f00c70 PZ |
10269 | if (IS_ERR(event)) { |
10270 | err = PTR_ERR(event); | |
10271 | goto err; | |
10272 | } | |
d859e29f | 10273 | |
f8697762 | 10274 | /* Mark owner so we could distinguish it from user events. */ |
63b6da39 | 10275 | event->owner = TASK_TOMBSTONE; |
f8697762 | 10276 | |
4af57ef2 | 10277 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
10278 | if (IS_ERR(ctx)) { |
10279 | err = PTR_ERR(ctx); | |
c3f00c70 | 10280 | goto err_free; |
d859e29f | 10281 | } |
fb0459d7 | 10282 | |
fb0459d7 AV |
10283 | WARN_ON_ONCE(ctx->parent_ctx); |
10284 | mutex_lock(&ctx->mutex); | |
84c4e620 PZ |
10285 | if (ctx->task == TASK_TOMBSTONE) { |
10286 | err = -ESRCH; | |
10287 | goto err_unlock; | |
10288 | } | |
10289 | ||
a63fbed7 TG |
10290 | if (!task) { |
10291 | /* | |
10292 | * Check if the @cpu we're creating an event for is online. | |
10293 | * | |
10294 | * We use the perf_cpu_context::ctx::mutex to serialize against | |
10295 | * the hotplug notifiers. See perf_event_{init,exit}_cpu(). | |
10296 | */ | |
10297 | struct perf_cpu_context *cpuctx = | |
10298 | container_of(ctx, struct perf_cpu_context, ctx); | |
10299 | if (!cpuctx->online) { | |
10300 | err = -ENODEV; | |
10301 | goto err_unlock; | |
10302 | } | |
10303 | } | |
10304 | ||
bed5b25a | 10305 | if (!exclusive_event_installable(event, ctx)) { |
bed5b25a | 10306 | err = -EBUSY; |
84c4e620 | 10307 | goto err_unlock; |
bed5b25a AS |
10308 | } |
10309 | ||
fb0459d7 | 10310 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 10311 | perf_unpin_context(ctx); |
fb0459d7 AV |
10312 | mutex_unlock(&ctx->mutex); |
10313 | ||
fb0459d7 AV |
10314 | return event; |
10315 | ||
84c4e620 PZ |
10316 | err_unlock: |
10317 | mutex_unlock(&ctx->mutex); | |
10318 | perf_unpin_context(ctx); | |
10319 | put_ctx(ctx); | |
c3f00c70 PZ |
10320 | err_free: |
10321 | free_event(event); | |
10322 | err: | |
c6567f64 | 10323 | return ERR_PTR(err); |
9b51f66d | 10324 | } |
fb0459d7 | 10325 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 10326 | |
0cda4c02 YZ |
10327 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
10328 | { | |
10329 | struct perf_event_context *src_ctx; | |
10330 | struct perf_event_context *dst_ctx; | |
10331 | struct perf_event *event, *tmp; | |
10332 | LIST_HEAD(events); | |
10333 | ||
10334 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
10335 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
10336 | ||
f63a8daa PZ |
10337 | /* |
10338 | * See perf_event_ctx_lock() for comments on the details | |
10339 | * of swizzling perf_event::ctx. | |
10340 | */ | |
10341 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
10342 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
10343 | event_entry) { | |
45a0e07a | 10344 | perf_remove_from_context(event, 0); |
9a545de0 | 10345 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 10346 | put_ctx(src_ctx); |
9886167d | 10347 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 10348 | } |
0cda4c02 | 10349 | |
8f95b435 PZI |
10350 | /* |
10351 | * Wait for the events to quiesce before re-instating them. | |
10352 | */ | |
0cda4c02 YZ |
10353 | synchronize_rcu(); |
10354 | ||
8f95b435 PZI |
10355 | /* |
10356 | * Re-instate events in 2 passes. | |
10357 | * | |
10358 | * Skip over group leaders and only install siblings on this first | |
10359 | * pass, siblings will not get enabled without a leader, however a | |
10360 | * leader will enable its siblings, even if those are still on the old | |
10361 | * context. | |
10362 | */ | |
10363 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
10364 | if (event->group_leader == event) | |
10365 | continue; | |
10366 | ||
10367 | list_del(&event->migrate_entry); | |
10368 | if (event->state >= PERF_EVENT_STATE_OFF) | |
10369 | event->state = PERF_EVENT_STATE_INACTIVE; | |
10370 | account_event_cpu(event, dst_cpu); | |
10371 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
10372 | get_ctx(dst_ctx); | |
10373 | } | |
10374 | ||
10375 | /* | |
10376 | * Once all the siblings are setup properly, install the group leaders | |
10377 | * to make it go. | |
10378 | */ | |
9886167d PZ |
10379 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
10380 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
10381 | if (event->state >= PERF_EVENT_STATE_OFF) |
10382 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 10383 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
10384 | perf_install_in_context(dst_ctx, event, dst_cpu); |
10385 | get_ctx(dst_ctx); | |
10386 | } | |
10387 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 10388 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
10389 | } |
10390 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
10391 | ||
cdd6c482 | 10392 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 10393 | struct task_struct *child) |
d859e29f | 10394 | { |
cdd6c482 | 10395 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 10396 | u64 child_val; |
d859e29f | 10397 | |
cdd6c482 IM |
10398 | if (child_event->attr.inherit_stat) |
10399 | perf_event_read_event(child_event, child); | |
38b200d6 | 10400 | |
b5e58793 | 10401 | child_val = perf_event_count(child_event); |
d859e29f PM |
10402 | |
10403 | /* | |
10404 | * Add back the child's count to the parent's count: | |
10405 | */ | |
a6e6dea6 | 10406 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
10407 | atomic64_add(child_event->total_time_enabled, |
10408 | &parent_event->child_total_time_enabled); | |
10409 | atomic64_add(child_event->total_time_running, | |
10410 | &parent_event->child_total_time_running); | |
d859e29f PM |
10411 | } |
10412 | ||
9b51f66d | 10413 | static void |
8ba289b8 PZ |
10414 | perf_event_exit_event(struct perf_event *child_event, |
10415 | struct perf_event_context *child_ctx, | |
10416 | struct task_struct *child) | |
9b51f66d | 10417 | { |
8ba289b8 PZ |
10418 | struct perf_event *parent_event = child_event->parent; |
10419 | ||
1903d50c PZ |
10420 | /* |
10421 | * Do not destroy the 'original' grouping; because of the context | |
10422 | * switch optimization the original events could've ended up in a | |
10423 | * random child task. | |
10424 | * | |
10425 | * If we were to destroy the original group, all group related | |
10426 | * operations would cease to function properly after this random | |
10427 | * child dies. | |
10428 | * | |
10429 | * Do destroy all inherited groups, we don't care about those | |
10430 | * and being thorough is better. | |
10431 | */ | |
32132a3d PZ |
10432 | raw_spin_lock_irq(&child_ctx->lock); |
10433 | WARN_ON_ONCE(child_ctx->is_active); | |
10434 | ||
8ba289b8 | 10435 | if (parent_event) |
32132a3d PZ |
10436 | perf_group_detach(child_event); |
10437 | list_del_event(child_event, child_ctx); | |
a69b0ca4 | 10438 | child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ |
32132a3d | 10439 | raw_spin_unlock_irq(&child_ctx->lock); |
0cc0c027 | 10440 | |
9b51f66d | 10441 | /* |
8ba289b8 | 10442 | * Parent events are governed by their filedesc, retain them. |
9b51f66d | 10443 | */ |
8ba289b8 | 10444 | if (!parent_event) { |
179033b3 | 10445 | perf_event_wakeup(child_event); |
8ba289b8 | 10446 | return; |
4bcf349a | 10447 | } |
8ba289b8 PZ |
10448 | /* |
10449 | * Child events can be cleaned up. | |
10450 | */ | |
10451 | ||
10452 | sync_child_event(child_event, child); | |
10453 | ||
10454 | /* | |
10455 | * Remove this event from the parent's list | |
10456 | */ | |
10457 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
10458 | mutex_lock(&parent_event->child_mutex); | |
10459 | list_del_init(&child_event->child_list); | |
10460 | mutex_unlock(&parent_event->child_mutex); | |
10461 | ||
10462 | /* | |
10463 | * Kick perf_poll() for is_event_hup(). | |
10464 | */ | |
10465 | perf_event_wakeup(parent_event); | |
10466 | free_event(child_event); | |
10467 | put_event(parent_event); | |
9b51f66d IM |
10468 | } |
10469 | ||
8dc85d54 | 10470 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 10471 | { |
211de6eb | 10472 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
63b6da39 | 10473 | struct perf_event *child_event, *next; |
63b6da39 PZ |
10474 | |
10475 | WARN_ON_ONCE(child != current); | |
9b51f66d | 10476 | |
6a3351b6 | 10477 | child_ctx = perf_pin_task_context(child, ctxn); |
63b6da39 | 10478 | if (!child_ctx) |
9b51f66d IM |
10479 | return; |
10480 | ||
ad3a37de | 10481 | /* |
6a3351b6 PZ |
10482 | * In order to reduce the amount of tricky in ctx tear-down, we hold |
10483 | * ctx::mutex over the entire thing. This serializes against almost | |
10484 | * everything that wants to access the ctx. | |
10485 | * | |
10486 | * The exception is sys_perf_event_open() / | |
10487 | * perf_event_create_kernel_count() which does find_get_context() | |
10488 | * without ctx::mutex (it cannot because of the move_group double mutex | |
10489 | * lock thing). See the comments in perf_install_in_context(). | |
ad3a37de | 10490 | */ |
6a3351b6 | 10491 | mutex_lock(&child_ctx->mutex); |
c93f7669 PM |
10492 | |
10493 | /* | |
6a3351b6 PZ |
10494 | * In a single ctx::lock section, de-schedule the events and detach the |
10495 | * context from the task such that we cannot ever get it scheduled back | |
10496 | * in. | |
c93f7669 | 10497 | */ |
6a3351b6 | 10498 | raw_spin_lock_irq(&child_ctx->lock); |
487f05e1 | 10499 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx, EVENT_ALL); |
4a1c0f26 | 10500 | |
71a851b4 | 10501 | /* |
63b6da39 PZ |
10502 | * Now that the context is inactive, destroy the task <-> ctx relation |
10503 | * and mark the context dead. | |
71a851b4 | 10504 | */ |
63b6da39 PZ |
10505 | RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL); |
10506 | put_ctx(child_ctx); /* cannot be last */ | |
10507 | WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); | |
10508 | put_task_struct(current); /* cannot be last */ | |
4a1c0f26 | 10509 | |
211de6eb | 10510 | clone_ctx = unclone_ctx(child_ctx); |
6a3351b6 | 10511 | raw_spin_unlock_irq(&child_ctx->lock); |
9f498cc5 | 10512 | |
211de6eb PZ |
10513 | if (clone_ctx) |
10514 | put_ctx(clone_ctx); | |
4a1c0f26 | 10515 | |
9f498cc5 | 10516 | /* |
cdd6c482 IM |
10517 | * Report the task dead after unscheduling the events so that we |
10518 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
10519 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 10520 | */ |
cdd6c482 | 10521 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 10522 | |
ebf905fc | 10523 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
8ba289b8 | 10524 | perf_event_exit_event(child_event, child_ctx, child); |
8bc20959 | 10525 | |
a63eaf34 PM |
10526 | mutex_unlock(&child_ctx->mutex); |
10527 | ||
10528 | put_ctx(child_ctx); | |
9b51f66d IM |
10529 | } |
10530 | ||
8dc85d54 PZ |
10531 | /* |
10532 | * When a child task exits, feed back event values to parent events. | |
79c9ce57 PZ |
10533 | * |
10534 | * Can be called with cred_guard_mutex held when called from | |
10535 | * install_exec_creds(). | |
8dc85d54 PZ |
10536 | */ |
10537 | void perf_event_exit_task(struct task_struct *child) | |
10538 | { | |
8882135b | 10539 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
10540 | int ctxn; |
10541 | ||
8882135b PZ |
10542 | mutex_lock(&child->perf_event_mutex); |
10543 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
10544 | owner_entry) { | |
10545 | list_del_init(&event->owner_entry); | |
10546 | ||
10547 | /* | |
10548 | * Ensure the list deletion is visible before we clear | |
10549 | * the owner, closes a race against perf_release() where | |
10550 | * we need to serialize on the owner->perf_event_mutex. | |
10551 | */ | |
f47c02c0 | 10552 | smp_store_release(&event->owner, NULL); |
8882135b PZ |
10553 | } |
10554 | mutex_unlock(&child->perf_event_mutex); | |
10555 | ||
8dc85d54 PZ |
10556 | for_each_task_context_nr(ctxn) |
10557 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
10558 | |
10559 | /* | |
10560 | * The perf_event_exit_task_context calls perf_event_task | |
10561 | * with child's task_ctx, which generates EXIT events for | |
10562 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
10563 | * At this point we need to send EXIT events to cpu contexts. | |
10564 | */ | |
10565 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
10566 | } |
10567 | ||
889ff015 FW |
10568 | static void perf_free_event(struct perf_event *event, |
10569 | struct perf_event_context *ctx) | |
10570 | { | |
10571 | struct perf_event *parent = event->parent; | |
10572 | ||
10573 | if (WARN_ON_ONCE(!parent)) | |
10574 | return; | |
10575 | ||
10576 | mutex_lock(&parent->child_mutex); | |
10577 | list_del_init(&event->child_list); | |
10578 | mutex_unlock(&parent->child_mutex); | |
10579 | ||
a6fa941d | 10580 | put_event(parent); |
889ff015 | 10581 | |
652884fe | 10582 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 10583 | perf_group_detach(event); |
889ff015 | 10584 | list_del_event(event, ctx); |
652884fe | 10585 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
10586 | free_event(event); |
10587 | } | |
10588 | ||
bbbee908 | 10589 | /* |
652884fe | 10590 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 10591 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
10592 | * |
10593 | * Not all locks are strictly required, but take them anyway to be nice and | |
10594 | * help out with the lockdep assertions. | |
bbbee908 | 10595 | */ |
cdd6c482 | 10596 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 10597 | { |
8dc85d54 | 10598 | struct perf_event_context *ctx; |
cdd6c482 | 10599 | struct perf_event *event, *tmp; |
8dc85d54 | 10600 | int ctxn; |
bbbee908 | 10601 | |
8dc85d54 PZ |
10602 | for_each_task_context_nr(ctxn) { |
10603 | ctx = task->perf_event_ctxp[ctxn]; | |
10604 | if (!ctx) | |
10605 | continue; | |
bbbee908 | 10606 | |
8dc85d54 | 10607 | mutex_lock(&ctx->mutex); |
e552a838 PZ |
10608 | raw_spin_lock_irq(&ctx->lock); |
10609 | /* | |
10610 | * Destroy the task <-> ctx relation and mark the context dead. | |
10611 | * | |
10612 | * This is important because even though the task hasn't been | |
10613 | * exposed yet the context has been (through child_list). | |
10614 | */ | |
10615 | RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], NULL); | |
10616 | WRITE_ONCE(ctx->task, TASK_TOMBSTONE); | |
10617 | put_task_struct(task); /* cannot be last */ | |
10618 | raw_spin_unlock_irq(&ctx->lock); | |
bbbee908 | 10619 | |
15121c78 | 10620 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) |
8dc85d54 | 10621 | perf_free_event(event, ctx); |
bbbee908 | 10622 | |
8dc85d54 | 10623 | mutex_unlock(&ctx->mutex); |
8dc85d54 PZ |
10624 | put_ctx(ctx); |
10625 | } | |
889ff015 FW |
10626 | } |
10627 | ||
4e231c79 PZ |
10628 | void perf_event_delayed_put(struct task_struct *task) |
10629 | { | |
10630 | int ctxn; | |
10631 | ||
10632 | for_each_task_context_nr(ctxn) | |
10633 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
10634 | } | |
10635 | ||
e03e7ee3 | 10636 | struct file *perf_event_get(unsigned int fd) |
ffe8690c | 10637 | { |
e03e7ee3 | 10638 | struct file *file; |
ffe8690c | 10639 | |
e03e7ee3 AS |
10640 | file = fget_raw(fd); |
10641 | if (!file) | |
10642 | return ERR_PTR(-EBADF); | |
ffe8690c | 10643 | |
e03e7ee3 AS |
10644 | if (file->f_op != &perf_fops) { |
10645 | fput(file); | |
10646 | return ERR_PTR(-EBADF); | |
10647 | } | |
ffe8690c | 10648 | |
e03e7ee3 | 10649 | return file; |
ffe8690c KX |
10650 | } |
10651 | ||
10652 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
10653 | { | |
10654 | if (!event) | |
10655 | return ERR_PTR(-EINVAL); | |
10656 | ||
10657 | return &event->attr; | |
10658 | } | |
10659 | ||
97dee4f3 | 10660 | /* |
d8a8cfc7 PZ |
10661 | * Inherit a event from parent task to child task. |
10662 | * | |
10663 | * Returns: | |
10664 | * - valid pointer on success | |
10665 | * - NULL for orphaned events | |
10666 | * - IS_ERR() on error | |
97dee4f3 PZ |
10667 | */ |
10668 | static struct perf_event * | |
10669 | inherit_event(struct perf_event *parent_event, | |
10670 | struct task_struct *parent, | |
10671 | struct perf_event_context *parent_ctx, | |
10672 | struct task_struct *child, | |
10673 | struct perf_event *group_leader, | |
10674 | struct perf_event_context *child_ctx) | |
10675 | { | |
1929def9 | 10676 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 10677 | struct perf_event *child_event; |
cee010ec | 10678 | unsigned long flags; |
97dee4f3 PZ |
10679 | |
10680 | /* | |
10681 | * Instead of creating recursive hierarchies of events, | |
10682 | * we link inherited events back to the original parent, | |
10683 | * which has a filp for sure, which we use as the reference | |
10684 | * count: | |
10685 | */ | |
10686 | if (parent_event->parent) | |
10687 | parent_event = parent_event->parent; | |
10688 | ||
10689 | child_event = perf_event_alloc(&parent_event->attr, | |
10690 | parent_event->cpu, | |
d580ff86 | 10691 | child, |
97dee4f3 | 10692 | group_leader, parent_event, |
79dff51e | 10693 | NULL, NULL, -1); |
97dee4f3 PZ |
10694 | if (IS_ERR(child_event)) |
10695 | return child_event; | |
a6fa941d | 10696 | |
c6e5b732 PZ |
10697 | /* |
10698 | * is_orphaned_event() and list_add_tail(&parent_event->child_list) | |
10699 | * must be under the same lock in order to serialize against | |
10700 | * perf_event_release_kernel(), such that either we must observe | |
10701 | * is_orphaned_event() or they will observe us on the child_list. | |
10702 | */ | |
10703 | mutex_lock(&parent_event->child_mutex); | |
fadfe7be JO |
10704 | if (is_orphaned_event(parent_event) || |
10705 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
c6e5b732 | 10706 | mutex_unlock(&parent_event->child_mutex); |
a6fa941d AV |
10707 | free_event(child_event); |
10708 | return NULL; | |
10709 | } | |
10710 | ||
97dee4f3 PZ |
10711 | get_ctx(child_ctx); |
10712 | ||
10713 | /* | |
10714 | * Make the child state follow the state of the parent event, | |
10715 | * not its attr.disabled bit. We hold the parent's mutex, | |
10716 | * so we won't race with perf_event_{en, dis}able_family. | |
10717 | */ | |
1929def9 | 10718 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
10719 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
10720 | else | |
10721 | child_event->state = PERF_EVENT_STATE_OFF; | |
10722 | ||
10723 | if (parent_event->attr.freq) { | |
10724 | u64 sample_period = parent_event->hw.sample_period; | |
10725 | struct hw_perf_event *hwc = &child_event->hw; | |
10726 | ||
10727 | hwc->sample_period = sample_period; | |
10728 | hwc->last_period = sample_period; | |
10729 | ||
10730 | local64_set(&hwc->period_left, sample_period); | |
10731 | } | |
10732 | ||
10733 | child_event->ctx = child_ctx; | |
10734 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
10735 | child_event->overflow_handler_context |
10736 | = parent_event->overflow_handler_context; | |
97dee4f3 | 10737 | |
614b6780 TG |
10738 | /* |
10739 | * Precalculate sample_data sizes | |
10740 | */ | |
10741 | perf_event__header_size(child_event); | |
6844c09d | 10742 | perf_event__id_header_size(child_event); |
614b6780 | 10743 | |
97dee4f3 PZ |
10744 | /* |
10745 | * Link it up in the child's context: | |
10746 | */ | |
cee010ec | 10747 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 10748 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 10749 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 10750 | |
97dee4f3 PZ |
10751 | /* |
10752 | * Link this into the parent event's child list | |
10753 | */ | |
97dee4f3 PZ |
10754 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
10755 | mutex_unlock(&parent_event->child_mutex); | |
10756 | ||
10757 | return child_event; | |
10758 | } | |
10759 | ||
d8a8cfc7 PZ |
10760 | /* |
10761 | * Inherits an event group. | |
10762 | * | |
10763 | * This will quietly suppress orphaned events; !inherit_event() is not an error. | |
10764 | * This matches with perf_event_release_kernel() removing all child events. | |
10765 | * | |
10766 | * Returns: | |
10767 | * - 0 on success | |
10768 | * - <0 on error | |
10769 | */ | |
97dee4f3 PZ |
10770 | static int inherit_group(struct perf_event *parent_event, |
10771 | struct task_struct *parent, | |
10772 | struct perf_event_context *parent_ctx, | |
10773 | struct task_struct *child, | |
10774 | struct perf_event_context *child_ctx) | |
10775 | { | |
10776 | struct perf_event *leader; | |
10777 | struct perf_event *sub; | |
10778 | struct perf_event *child_ctr; | |
10779 | ||
10780 | leader = inherit_event(parent_event, parent, parent_ctx, | |
10781 | child, NULL, child_ctx); | |
10782 | if (IS_ERR(leader)) | |
10783 | return PTR_ERR(leader); | |
d8a8cfc7 PZ |
10784 | /* |
10785 | * @leader can be NULL here because of is_orphaned_event(). In this | |
10786 | * case inherit_event() will create individual events, similar to what | |
10787 | * perf_group_detach() would do anyway. | |
10788 | */ | |
97dee4f3 PZ |
10789 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { |
10790 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
10791 | child, leader, child_ctx); | |
10792 | if (IS_ERR(child_ctr)) | |
10793 | return PTR_ERR(child_ctr); | |
10794 | } | |
10795 | return 0; | |
889ff015 FW |
10796 | } |
10797 | ||
d8a8cfc7 PZ |
10798 | /* |
10799 | * Creates the child task context and tries to inherit the event-group. | |
10800 | * | |
10801 | * Clears @inherited_all on !attr.inherited or error. Note that we'll leave | |
10802 | * inherited_all set when we 'fail' to inherit an orphaned event; this is | |
10803 | * consistent with perf_event_release_kernel() removing all child events. | |
10804 | * | |
10805 | * Returns: | |
10806 | * - 0 on success | |
10807 | * - <0 on error | |
10808 | */ | |
889ff015 FW |
10809 | static int |
10810 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
10811 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 10812 | struct task_struct *child, int ctxn, |
889ff015 FW |
10813 | int *inherited_all) |
10814 | { | |
10815 | int ret; | |
8dc85d54 | 10816 | struct perf_event_context *child_ctx; |
889ff015 FW |
10817 | |
10818 | if (!event->attr.inherit) { | |
10819 | *inherited_all = 0; | |
10820 | return 0; | |
bbbee908 PZ |
10821 | } |
10822 | ||
fe4b04fa | 10823 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
10824 | if (!child_ctx) { |
10825 | /* | |
10826 | * This is executed from the parent task context, so | |
10827 | * inherit events that have been marked for cloning. | |
10828 | * First allocate and initialize a context for the | |
10829 | * child. | |
10830 | */ | |
734df5ab | 10831 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
10832 | if (!child_ctx) |
10833 | return -ENOMEM; | |
bbbee908 | 10834 | |
8dc85d54 | 10835 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
10836 | } |
10837 | ||
10838 | ret = inherit_group(event, parent, parent_ctx, | |
10839 | child, child_ctx); | |
10840 | ||
10841 | if (ret) | |
10842 | *inherited_all = 0; | |
10843 | ||
10844 | return ret; | |
bbbee908 PZ |
10845 | } |
10846 | ||
9b51f66d | 10847 | /* |
cdd6c482 | 10848 | * Initialize the perf_event context in task_struct |
9b51f66d | 10849 | */ |
985c8dcb | 10850 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 10851 | { |
889ff015 | 10852 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
10853 | struct perf_event_context *cloned_ctx; |
10854 | struct perf_event *event; | |
9b51f66d | 10855 | struct task_struct *parent = current; |
564c2b21 | 10856 | int inherited_all = 1; |
dddd3379 | 10857 | unsigned long flags; |
6ab423e0 | 10858 | int ret = 0; |
9b51f66d | 10859 | |
8dc85d54 | 10860 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
10861 | return 0; |
10862 | ||
ad3a37de | 10863 | /* |
25346b93 PM |
10864 | * If the parent's context is a clone, pin it so it won't get |
10865 | * swapped under us. | |
ad3a37de | 10866 | */ |
8dc85d54 | 10867 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
10868 | if (!parent_ctx) |
10869 | return 0; | |
25346b93 | 10870 | |
ad3a37de PM |
10871 | /* |
10872 | * No need to check if parent_ctx != NULL here; since we saw | |
10873 | * it non-NULL earlier, the only reason for it to become NULL | |
10874 | * is if we exit, and since we're currently in the middle of | |
10875 | * a fork we can't be exiting at the same time. | |
10876 | */ | |
ad3a37de | 10877 | |
9b51f66d IM |
10878 | /* |
10879 | * Lock the parent list. No need to lock the child - not PID | |
10880 | * hashed yet and not running, so nobody can access it. | |
10881 | */ | |
d859e29f | 10882 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
10883 | |
10884 | /* | |
10885 | * We dont have to disable NMIs - we are only looking at | |
10886 | * the list, not manipulating it: | |
10887 | */ | |
889ff015 | 10888 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
10889 | ret = inherit_task_group(event, parent, parent_ctx, |
10890 | child, ctxn, &inherited_all); | |
889ff015 | 10891 | if (ret) |
e7cc4865 | 10892 | goto out_unlock; |
889ff015 | 10893 | } |
b93f7978 | 10894 | |
dddd3379 TG |
10895 | /* |
10896 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
10897 | * to allocations, but we need to prevent rotation because | |
10898 | * rotate_ctx() will change the list from interrupt context. | |
10899 | */ | |
10900 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
10901 | parent_ctx->rotate_disable = 1; | |
10902 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
10903 | ||
889ff015 | 10904 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
10905 | ret = inherit_task_group(event, parent, parent_ctx, |
10906 | child, ctxn, &inherited_all); | |
889ff015 | 10907 | if (ret) |
e7cc4865 | 10908 | goto out_unlock; |
564c2b21 PM |
10909 | } |
10910 | ||
dddd3379 TG |
10911 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
10912 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 10913 | |
8dc85d54 | 10914 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 10915 | |
05cbaa28 | 10916 | if (child_ctx && inherited_all) { |
564c2b21 PM |
10917 | /* |
10918 | * Mark the child context as a clone of the parent | |
10919 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
10920 | * |
10921 | * Note that if the parent is a clone, the holding of | |
10922 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 10923 | */ |
c5ed5145 | 10924 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
10925 | if (cloned_ctx) { |
10926 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 10927 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
10928 | } else { |
10929 | child_ctx->parent_ctx = parent_ctx; | |
10930 | child_ctx->parent_gen = parent_ctx->generation; | |
10931 | } | |
10932 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
10933 | } |
10934 | ||
c5ed5145 | 10935 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
e7cc4865 | 10936 | out_unlock: |
d859e29f | 10937 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 10938 | |
25346b93 | 10939 | perf_unpin_context(parent_ctx); |
fe4b04fa | 10940 | put_ctx(parent_ctx); |
ad3a37de | 10941 | |
6ab423e0 | 10942 | return ret; |
9b51f66d IM |
10943 | } |
10944 | ||
8dc85d54 PZ |
10945 | /* |
10946 | * Initialize the perf_event context in task_struct | |
10947 | */ | |
10948 | int perf_event_init_task(struct task_struct *child) | |
10949 | { | |
10950 | int ctxn, ret; | |
10951 | ||
8550d7cb ON |
10952 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
10953 | mutex_init(&child->perf_event_mutex); | |
10954 | INIT_LIST_HEAD(&child->perf_event_list); | |
10955 | ||
8dc85d54 PZ |
10956 | for_each_task_context_nr(ctxn) { |
10957 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
10958 | if (ret) { |
10959 | perf_event_free_task(child); | |
8dc85d54 | 10960 | return ret; |
6c72e350 | 10961 | } |
8dc85d54 PZ |
10962 | } |
10963 | ||
10964 | return 0; | |
10965 | } | |
10966 | ||
220b140b PM |
10967 | static void __init perf_event_init_all_cpus(void) |
10968 | { | |
b28ab83c | 10969 | struct swevent_htable *swhash; |
220b140b | 10970 | int cpu; |
220b140b | 10971 | |
a63fbed7 TG |
10972 | zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL); |
10973 | ||
220b140b | 10974 | for_each_possible_cpu(cpu) { |
b28ab83c PZ |
10975 | swhash = &per_cpu(swevent_htable, cpu); |
10976 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 10977 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
f2fb6bef KL |
10978 | |
10979 | INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu)); | |
10980 | raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu)); | |
e48c1788 | 10981 | |
058fe1c0 DCC |
10982 | #ifdef CONFIG_CGROUP_PERF |
10983 | INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list, cpu)); | |
10984 | #endif | |
e48c1788 | 10985 | INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu)); |
220b140b PM |
10986 | } |
10987 | } | |
10988 | ||
a63fbed7 | 10989 | void perf_swevent_init_cpu(unsigned int cpu) |
0793a61d | 10990 | { |
108b02cf | 10991 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 10992 | |
b28ab83c | 10993 | mutex_lock(&swhash->hlist_mutex); |
059fcd8c | 10994 | if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { |
76e1d904 FW |
10995 | struct swevent_hlist *hlist; |
10996 | ||
b28ab83c PZ |
10997 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
10998 | WARN_ON(!hlist); | |
10999 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 11000 | } |
b28ab83c | 11001 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
11002 | } |
11003 | ||
2965faa5 | 11004 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 11005 | static void __perf_event_exit_context(void *__info) |
0793a61d | 11006 | { |
108b02cf | 11007 | struct perf_event_context *ctx = __info; |
fae3fde6 PZ |
11008 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
11009 | struct perf_event *event; | |
0793a61d | 11010 | |
fae3fde6 PZ |
11011 | raw_spin_lock(&ctx->lock); |
11012 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
45a0e07a | 11013 | __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); |
fae3fde6 | 11014 | raw_spin_unlock(&ctx->lock); |
0793a61d | 11015 | } |
108b02cf PZ |
11016 | |
11017 | static void perf_event_exit_cpu_context(int cpu) | |
11018 | { | |
a63fbed7 | 11019 | struct perf_cpu_context *cpuctx; |
108b02cf PZ |
11020 | struct perf_event_context *ctx; |
11021 | struct pmu *pmu; | |
108b02cf | 11022 | |
a63fbed7 TG |
11023 | mutex_lock(&pmus_lock); |
11024 | list_for_each_entry(pmu, &pmus, entry) { | |
11025 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
11026 | ctx = &cpuctx->ctx; | |
108b02cf PZ |
11027 | |
11028 | mutex_lock(&ctx->mutex); | |
11029 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
a63fbed7 | 11030 | cpuctx->online = 0; |
108b02cf PZ |
11031 | mutex_unlock(&ctx->mutex); |
11032 | } | |
a63fbed7 TG |
11033 | cpumask_clear_cpu(cpu, perf_online_mask); |
11034 | mutex_unlock(&pmus_lock); | |
108b02cf | 11035 | } |
00e16c3d TG |
11036 | #else |
11037 | ||
11038 | static void perf_event_exit_cpu_context(int cpu) { } | |
11039 | ||
11040 | #endif | |
108b02cf | 11041 | |
a63fbed7 TG |
11042 | int perf_event_init_cpu(unsigned int cpu) |
11043 | { | |
11044 | struct perf_cpu_context *cpuctx; | |
11045 | struct perf_event_context *ctx; | |
11046 | struct pmu *pmu; | |
11047 | ||
11048 | perf_swevent_init_cpu(cpu); | |
11049 | ||
11050 | mutex_lock(&pmus_lock); | |
11051 | cpumask_set_cpu(cpu, perf_online_mask); | |
11052 | list_for_each_entry(pmu, &pmus, entry) { | |
11053 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
11054 | ctx = &cpuctx->ctx; | |
11055 | ||
11056 | mutex_lock(&ctx->mutex); | |
11057 | cpuctx->online = 1; | |
11058 | mutex_unlock(&ctx->mutex); | |
11059 | } | |
11060 | mutex_unlock(&pmus_lock); | |
11061 | ||
11062 | return 0; | |
11063 | } | |
11064 | ||
00e16c3d | 11065 | int perf_event_exit_cpu(unsigned int cpu) |
0793a61d | 11066 | { |
e3703f8c | 11067 | perf_event_exit_cpu_context(cpu); |
00e16c3d | 11068 | return 0; |
0793a61d | 11069 | } |
0793a61d | 11070 | |
c277443c PZ |
11071 | static int |
11072 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
11073 | { | |
11074 | int cpu; | |
11075 | ||
11076 | for_each_online_cpu(cpu) | |
11077 | perf_event_exit_cpu(cpu); | |
11078 | ||
11079 | return NOTIFY_OK; | |
11080 | } | |
11081 | ||
11082 | /* | |
11083 | * Run the perf reboot notifier at the very last possible moment so that | |
11084 | * the generic watchdog code runs as long as possible. | |
11085 | */ | |
11086 | static struct notifier_block perf_reboot_notifier = { | |
11087 | .notifier_call = perf_reboot, | |
11088 | .priority = INT_MIN, | |
11089 | }; | |
11090 | ||
cdd6c482 | 11091 | void __init perf_event_init(void) |
0793a61d | 11092 | { |
3c502e7a JW |
11093 | int ret; |
11094 | ||
2e80a82a PZ |
11095 | idr_init(&pmu_idr); |
11096 | ||
220b140b | 11097 | perf_event_init_all_cpus(); |
b0a873eb | 11098 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
11099 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
11100 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
11101 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb | 11102 | perf_tp_register(); |
00e16c3d | 11103 | perf_event_init_cpu(smp_processor_id()); |
c277443c | 11104 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
11105 | |
11106 | ret = init_hw_breakpoint(); | |
11107 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 | 11108 | |
b01c3a00 JO |
11109 | /* |
11110 | * Build time assertion that we keep the data_head at the intended | |
11111 | * location. IOW, validation we got the __reserved[] size right. | |
11112 | */ | |
11113 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
11114 | != 1024); | |
0793a61d | 11115 | } |
abe43400 | 11116 | |
fd979c01 CS |
11117 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
11118 | char *page) | |
11119 | { | |
11120 | struct perf_pmu_events_attr *pmu_attr = | |
11121 | container_of(attr, struct perf_pmu_events_attr, attr); | |
11122 | ||
11123 | if (pmu_attr->event_str) | |
11124 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
11125 | ||
11126 | return 0; | |
11127 | } | |
675965b0 | 11128 | EXPORT_SYMBOL_GPL(perf_event_sysfs_show); |
fd979c01 | 11129 | |
abe43400 PZ |
11130 | static int __init perf_event_sysfs_init(void) |
11131 | { | |
11132 | struct pmu *pmu; | |
11133 | int ret; | |
11134 | ||
11135 | mutex_lock(&pmus_lock); | |
11136 | ||
11137 | ret = bus_register(&pmu_bus); | |
11138 | if (ret) | |
11139 | goto unlock; | |
11140 | ||
11141 | list_for_each_entry(pmu, &pmus, entry) { | |
11142 | if (!pmu->name || pmu->type < 0) | |
11143 | continue; | |
11144 | ||
11145 | ret = pmu_dev_alloc(pmu); | |
11146 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
11147 | } | |
11148 | pmu_bus_running = 1; | |
11149 | ret = 0; | |
11150 | ||
11151 | unlock: | |
11152 | mutex_unlock(&pmus_lock); | |
11153 | ||
11154 | return ret; | |
11155 | } | |
11156 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
11157 | |
11158 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
11159 | static struct cgroup_subsys_state * |
11160 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
11161 | { |
11162 | struct perf_cgroup *jc; | |
e5d1367f | 11163 | |
1b15d055 | 11164 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
11165 | if (!jc) |
11166 | return ERR_PTR(-ENOMEM); | |
11167 | ||
e5d1367f SE |
11168 | jc->info = alloc_percpu(struct perf_cgroup_info); |
11169 | if (!jc->info) { | |
11170 | kfree(jc); | |
11171 | return ERR_PTR(-ENOMEM); | |
11172 | } | |
11173 | ||
e5d1367f SE |
11174 | return &jc->css; |
11175 | } | |
11176 | ||
eb95419b | 11177 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 11178 | { |
eb95419b TH |
11179 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
11180 | ||
e5d1367f SE |
11181 | free_percpu(jc->info); |
11182 | kfree(jc); | |
11183 | } | |
11184 | ||
11185 | static int __perf_cgroup_move(void *info) | |
11186 | { | |
11187 | struct task_struct *task = info; | |
ddaaf4e2 | 11188 | rcu_read_lock(); |
e5d1367f | 11189 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 11190 | rcu_read_unlock(); |
e5d1367f SE |
11191 | return 0; |
11192 | } | |
11193 | ||
1f7dd3e5 | 11194 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 11195 | { |
bb9d97b6 | 11196 | struct task_struct *task; |
1f7dd3e5 | 11197 | struct cgroup_subsys_state *css; |
bb9d97b6 | 11198 | |
1f7dd3e5 | 11199 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 11200 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
11201 | } |
11202 | ||
073219e9 | 11203 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
11204 | .css_alloc = perf_cgroup_css_alloc, |
11205 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 11206 | .attach = perf_cgroup_attach, |
968ebff1 TH |
11207 | /* |
11208 | * Implicitly enable on dfl hierarchy so that perf events can | |
11209 | * always be filtered by cgroup2 path as long as perf_event | |
11210 | * controller is not mounted on a legacy hierarchy. | |
11211 | */ | |
11212 | .implicit_on_dfl = true, | |
e5d1367f SE |
11213 | }; |
11214 | #endif /* CONFIG_CGROUP_PERF */ |