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Commit | Line | Data |
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0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
fadfe7be JO |
52 | static struct workqueue_struct *perf_wq; |
53 | ||
272325c4 PZ |
54 | typedef int (*remote_function_f)(void *); |
55 | ||
fe4b04fa | 56 | struct remote_function_call { |
e7e7ee2e | 57 | struct task_struct *p; |
272325c4 | 58 | remote_function_f func; |
e7e7ee2e IM |
59 | void *info; |
60 | int ret; | |
fe4b04fa PZ |
61 | }; |
62 | ||
63 | static void remote_function(void *data) | |
64 | { | |
65 | struct remote_function_call *tfc = data; | |
66 | struct task_struct *p = tfc->p; | |
67 | ||
68 | if (p) { | |
69 | tfc->ret = -EAGAIN; | |
70 | if (task_cpu(p) != smp_processor_id() || !task_curr(p)) | |
71 | return; | |
72 | } | |
73 | ||
74 | tfc->ret = tfc->func(tfc->info); | |
75 | } | |
76 | ||
77 | /** | |
78 | * task_function_call - call a function on the cpu on which a task runs | |
79 | * @p: the task to evaluate | |
80 | * @func: the function to be called | |
81 | * @info: the function call argument | |
82 | * | |
83 | * Calls the function @func when the task is currently running. This might | |
84 | * be on the current CPU, which just calls the function directly | |
85 | * | |
86 | * returns: @func return value, or | |
87 | * -ESRCH - when the process isn't running | |
88 | * -EAGAIN - when the process moved away | |
89 | */ | |
90 | static int | |
272325c4 | 91 | task_function_call(struct task_struct *p, remote_function_f func, void *info) |
fe4b04fa PZ |
92 | { |
93 | struct remote_function_call data = { | |
e7e7ee2e IM |
94 | .p = p, |
95 | .func = func, | |
96 | .info = info, | |
97 | .ret = -ESRCH, /* No such (running) process */ | |
fe4b04fa PZ |
98 | }; |
99 | ||
100 | if (task_curr(p)) | |
101 | smp_call_function_single(task_cpu(p), remote_function, &data, 1); | |
102 | ||
103 | return data.ret; | |
104 | } | |
105 | ||
106 | /** | |
107 | * cpu_function_call - call a function on the cpu | |
108 | * @func: the function to be called | |
109 | * @info: the function call argument | |
110 | * | |
111 | * Calls the function @func on the remote cpu. | |
112 | * | |
113 | * returns: @func return value or -ENXIO when the cpu is offline | |
114 | */ | |
272325c4 | 115 | static int cpu_function_call(int cpu, remote_function_f func, void *info) |
fe4b04fa PZ |
116 | { |
117 | struct remote_function_call data = { | |
e7e7ee2e IM |
118 | .p = NULL, |
119 | .func = func, | |
120 | .info = info, | |
121 | .ret = -ENXIO, /* No such CPU */ | |
fe4b04fa PZ |
122 | }; |
123 | ||
124 | smp_call_function_single(cpu, remote_function, &data, 1); | |
125 | ||
126 | return data.ret; | |
127 | } | |
128 | ||
0017960f PZ |
129 | static void event_function_call(struct perf_event *event, |
130 | int (*active)(void *), | |
131 | void (*inactive)(void *), | |
132 | void *data) | |
133 | { | |
134 | struct perf_event_context *ctx = event->ctx; | |
135 | struct task_struct *task = ctx->task; | |
136 | ||
137 | if (!task) { | |
138 | cpu_function_call(event->cpu, active, data); | |
139 | return; | |
140 | } | |
141 | ||
142 | again: | |
143 | if (!task_function_call(task, active, data)) | |
144 | return; | |
145 | ||
146 | raw_spin_lock_irq(&ctx->lock); | |
147 | if (ctx->is_active) { | |
148 | /* | |
149 | * Reload the task pointer, it might have been changed by | |
150 | * a concurrent perf_event_context_sched_out(). | |
151 | */ | |
152 | task = ctx->task; | |
153 | raw_spin_unlock_irq(&ctx->lock); | |
154 | goto again; | |
155 | } | |
156 | inactive(data); | |
157 | raw_spin_unlock_irq(&ctx->lock); | |
158 | } | |
159 | ||
f8697762 JO |
160 | #define EVENT_OWNER_KERNEL ((void *) -1) |
161 | ||
162 | static bool is_kernel_event(struct perf_event *event) | |
163 | { | |
164 | return event->owner == EVENT_OWNER_KERNEL; | |
165 | } | |
166 | ||
e5d1367f SE |
167 | #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ |
168 | PERF_FLAG_FD_OUTPUT |\ | |
a21b0b35 YD |
169 | PERF_FLAG_PID_CGROUP |\ |
170 | PERF_FLAG_FD_CLOEXEC) | |
e5d1367f | 171 | |
bce38cd5 SE |
172 | /* |
173 | * branch priv levels that need permission checks | |
174 | */ | |
175 | #define PERF_SAMPLE_BRANCH_PERM_PLM \ | |
176 | (PERF_SAMPLE_BRANCH_KERNEL |\ | |
177 | PERF_SAMPLE_BRANCH_HV) | |
178 | ||
0b3fcf17 SE |
179 | enum event_type_t { |
180 | EVENT_FLEXIBLE = 0x1, | |
181 | EVENT_PINNED = 0x2, | |
182 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, | |
183 | }; | |
184 | ||
e5d1367f SE |
185 | /* |
186 | * perf_sched_events : >0 events exist | |
187 | * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu | |
188 | */ | |
c5905afb | 189 | struct static_key_deferred perf_sched_events __read_mostly; |
e5d1367f | 190 | static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); |
ba532500 | 191 | static DEFINE_PER_CPU(int, perf_sched_cb_usages); |
e5d1367f | 192 | |
cdd6c482 IM |
193 | static atomic_t nr_mmap_events __read_mostly; |
194 | static atomic_t nr_comm_events __read_mostly; | |
195 | static atomic_t nr_task_events __read_mostly; | |
948b26b6 | 196 | static atomic_t nr_freq_events __read_mostly; |
45ac1403 | 197 | static atomic_t nr_switch_events __read_mostly; |
9ee318a7 | 198 | |
108b02cf PZ |
199 | static LIST_HEAD(pmus); |
200 | static DEFINE_MUTEX(pmus_lock); | |
201 | static struct srcu_struct pmus_srcu; | |
202 | ||
0764771d | 203 | /* |
cdd6c482 | 204 | * perf event paranoia level: |
0fbdea19 IM |
205 | * -1 - not paranoid at all |
206 | * 0 - disallow raw tracepoint access for unpriv | |
cdd6c482 | 207 | * 1 - disallow cpu events for unpriv |
0fbdea19 | 208 | * 2 - disallow kernel profiling for unpriv |
0764771d | 209 | */ |
cdd6c482 | 210 | int sysctl_perf_event_paranoid __read_mostly = 1; |
0764771d | 211 | |
20443384 FW |
212 | /* Minimum for 512 kiB + 1 user control page */ |
213 | int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ | |
df58ab24 PZ |
214 | |
215 | /* | |
cdd6c482 | 216 | * max perf event sample rate |
df58ab24 | 217 | */ |
14c63f17 DH |
218 | #define DEFAULT_MAX_SAMPLE_RATE 100000 |
219 | #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE) | |
220 | #define DEFAULT_CPU_TIME_MAX_PERCENT 25 | |
221 | ||
222 | int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; | |
223 | ||
224 | static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); | |
225 | static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; | |
226 | ||
d9494cb4 PZ |
227 | static int perf_sample_allowed_ns __read_mostly = |
228 | DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100; | |
14c63f17 | 229 | |
18ab2cd3 | 230 | static void update_perf_cpu_limits(void) |
14c63f17 DH |
231 | { |
232 | u64 tmp = perf_sample_period_ns; | |
233 | ||
234 | tmp *= sysctl_perf_cpu_time_max_percent; | |
e5302920 | 235 | do_div(tmp, 100); |
d9494cb4 | 236 | ACCESS_ONCE(perf_sample_allowed_ns) = tmp; |
14c63f17 | 237 | } |
163ec435 | 238 | |
9e630205 SE |
239 | static int perf_rotate_context(struct perf_cpu_context *cpuctx); |
240 | ||
163ec435 PZ |
241 | int perf_proc_update_handler(struct ctl_table *table, int write, |
242 | void __user *buffer, size_t *lenp, | |
243 | loff_t *ppos) | |
244 | { | |
723478c8 | 245 | int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
163ec435 PZ |
246 | |
247 | if (ret || !write) | |
248 | return ret; | |
249 | ||
250 | max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); | |
14c63f17 DH |
251 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; |
252 | update_perf_cpu_limits(); | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; | |
258 | ||
259 | int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, | |
260 | void __user *buffer, size_t *lenp, | |
261 | loff_t *ppos) | |
262 | { | |
263 | int ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
264 | ||
265 | if (ret || !write) | |
266 | return ret; | |
267 | ||
268 | update_perf_cpu_limits(); | |
163ec435 PZ |
269 | |
270 | return 0; | |
271 | } | |
1ccd1549 | 272 | |
14c63f17 DH |
273 | /* |
274 | * perf samples are done in some very critical code paths (NMIs). | |
275 | * If they take too much CPU time, the system can lock up and not | |
276 | * get any real work done. This will drop the sample rate when | |
277 | * we detect that events are taking too long. | |
278 | */ | |
279 | #define NR_ACCUMULATED_SAMPLES 128 | |
d9494cb4 | 280 | static DEFINE_PER_CPU(u64, running_sample_length); |
14c63f17 | 281 | |
6a02ad66 | 282 | static void perf_duration_warn(struct irq_work *w) |
14c63f17 | 283 | { |
6a02ad66 | 284 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
14c63f17 | 285 | u64 avg_local_sample_len; |
e5302920 | 286 | u64 local_samples_len; |
6a02ad66 | 287 | |
4a32fea9 | 288 | local_samples_len = __this_cpu_read(running_sample_length); |
6a02ad66 PZ |
289 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; |
290 | ||
291 | printk_ratelimited(KERN_WARNING | |
292 | "perf interrupt took too long (%lld > %lld), lowering " | |
293 | "kernel.perf_event_max_sample_rate to %d\n", | |
cd578abb | 294 | avg_local_sample_len, allowed_ns >> 1, |
6a02ad66 PZ |
295 | sysctl_perf_event_sample_rate); |
296 | } | |
297 | ||
298 | static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn); | |
299 | ||
300 | void perf_sample_event_took(u64 sample_len_ns) | |
301 | { | |
d9494cb4 | 302 | u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns); |
6a02ad66 PZ |
303 | u64 avg_local_sample_len; |
304 | u64 local_samples_len; | |
14c63f17 | 305 | |
d9494cb4 | 306 | if (allowed_ns == 0) |
14c63f17 DH |
307 | return; |
308 | ||
309 | /* decay the counter by 1 average sample */ | |
4a32fea9 | 310 | local_samples_len = __this_cpu_read(running_sample_length); |
14c63f17 DH |
311 | local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES; |
312 | local_samples_len += sample_len_ns; | |
4a32fea9 | 313 | __this_cpu_write(running_sample_length, local_samples_len); |
14c63f17 DH |
314 | |
315 | /* | |
316 | * note: this will be biased artifically low until we have | |
317 | * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us | |
318 | * from having to maintain a count. | |
319 | */ | |
320 | avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES; | |
321 | ||
d9494cb4 | 322 | if (avg_local_sample_len <= allowed_ns) |
14c63f17 DH |
323 | return; |
324 | ||
325 | if (max_samples_per_tick <= 1) | |
326 | return; | |
327 | ||
328 | max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2); | |
329 | sysctl_perf_event_sample_rate = max_samples_per_tick * HZ; | |
330 | perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; | |
331 | ||
14c63f17 | 332 | update_perf_cpu_limits(); |
6a02ad66 | 333 | |
cd578abb PZ |
334 | if (!irq_work_queue(&perf_duration_work)) { |
335 | early_printk("perf interrupt took too long (%lld > %lld), lowering " | |
336 | "kernel.perf_event_max_sample_rate to %d\n", | |
337 | avg_local_sample_len, allowed_ns >> 1, | |
338 | sysctl_perf_event_sample_rate); | |
339 | } | |
14c63f17 DH |
340 | } |
341 | ||
cdd6c482 | 342 | static atomic64_t perf_event_id; |
a96bbc16 | 343 | |
0b3fcf17 SE |
344 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
345 | enum event_type_t event_type); | |
346 | ||
347 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
348 | enum event_type_t event_type, |
349 | struct task_struct *task); | |
350 | ||
351 | static void update_context_time(struct perf_event_context *ctx); | |
352 | static u64 perf_event_time(struct perf_event *event); | |
0b3fcf17 | 353 | |
cdd6c482 | 354 | void __weak perf_event_print_debug(void) { } |
0793a61d | 355 | |
84c79910 | 356 | extern __weak const char *perf_pmu_name(void) |
0793a61d | 357 | { |
84c79910 | 358 | return "pmu"; |
0793a61d TG |
359 | } |
360 | ||
0b3fcf17 SE |
361 | static inline u64 perf_clock(void) |
362 | { | |
363 | return local_clock(); | |
364 | } | |
365 | ||
34f43927 PZ |
366 | static inline u64 perf_event_clock(struct perf_event *event) |
367 | { | |
368 | return event->clock(); | |
369 | } | |
370 | ||
e5d1367f SE |
371 | static inline struct perf_cpu_context * |
372 | __get_cpu_context(struct perf_event_context *ctx) | |
373 | { | |
374 | return this_cpu_ptr(ctx->pmu->pmu_cpu_context); | |
375 | } | |
376 | ||
facc4307 PZ |
377 | static void perf_ctx_lock(struct perf_cpu_context *cpuctx, |
378 | struct perf_event_context *ctx) | |
379 | { | |
380 | raw_spin_lock(&cpuctx->ctx.lock); | |
381 | if (ctx) | |
382 | raw_spin_lock(&ctx->lock); | |
383 | } | |
384 | ||
385 | static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, | |
386 | struct perf_event_context *ctx) | |
387 | { | |
388 | if (ctx) | |
389 | raw_spin_unlock(&ctx->lock); | |
390 | raw_spin_unlock(&cpuctx->ctx.lock); | |
391 | } | |
392 | ||
e5d1367f SE |
393 | #ifdef CONFIG_CGROUP_PERF |
394 | ||
e5d1367f SE |
395 | static inline bool |
396 | perf_cgroup_match(struct perf_event *event) | |
397 | { | |
398 | struct perf_event_context *ctx = event->ctx; | |
399 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); | |
400 | ||
ef824fa1 TH |
401 | /* @event doesn't care about cgroup */ |
402 | if (!event->cgrp) | |
403 | return true; | |
404 | ||
405 | /* wants specific cgroup scope but @cpuctx isn't associated with any */ | |
406 | if (!cpuctx->cgrp) | |
407 | return false; | |
408 | ||
409 | /* | |
410 | * Cgroup scoping is recursive. An event enabled for a cgroup is | |
411 | * also enabled for all its descendant cgroups. If @cpuctx's | |
412 | * cgroup is a descendant of @event's (the test covers identity | |
413 | * case), it's a match. | |
414 | */ | |
415 | return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, | |
416 | event->cgrp->css.cgroup); | |
e5d1367f SE |
417 | } |
418 | ||
e5d1367f SE |
419 | static inline void perf_detach_cgroup(struct perf_event *event) |
420 | { | |
4e2ba650 | 421 | css_put(&event->cgrp->css); |
e5d1367f SE |
422 | event->cgrp = NULL; |
423 | } | |
424 | ||
425 | static inline int is_cgroup_event(struct perf_event *event) | |
426 | { | |
427 | return event->cgrp != NULL; | |
428 | } | |
429 | ||
430 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
431 | { | |
432 | struct perf_cgroup_info *t; | |
433 | ||
434 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
435 | return t->time; | |
436 | } | |
437 | ||
438 | static inline void __update_cgrp_time(struct perf_cgroup *cgrp) | |
439 | { | |
440 | struct perf_cgroup_info *info; | |
441 | u64 now; | |
442 | ||
443 | now = perf_clock(); | |
444 | ||
445 | info = this_cpu_ptr(cgrp->info); | |
446 | ||
447 | info->time += now - info->timestamp; | |
448 | info->timestamp = now; | |
449 | } | |
450 | ||
451 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
452 | { | |
453 | struct perf_cgroup *cgrp_out = cpuctx->cgrp; | |
454 | if (cgrp_out) | |
455 | __update_cgrp_time(cgrp_out); | |
456 | } | |
457 | ||
458 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
459 | { | |
3f7cce3c SE |
460 | struct perf_cgroup *cgrp; |
461 | ||
e5d1367f | 462 | /* |
3f7cce3c SE |
463 | * ensure we access cgroup data only when needed and |
464 | * when we know the cgroup is pinned (css_get) | |
e5d1367f | 465 | */ |
3f7cce3c | 466 | if (!is_cgroup_event(event)) |
e5d1367f SE |
467 | return; |
468 | ||
614e4c4e | 469 | cgrp = perf_cgroup_from_task(current, event->ctx); |
3f7cce3c SE |
470 | /* |
471 | * Do not update time when cgroup is not active | |
472 | */ | |
473 | if (cgrp == event->cgrp) | |
474 | __update_cgrp_time(event->cgrp); | |
e5d1367f SE |
475 | } |
476 | ||
477 | static inline void | |
3f7cce3c SE |
478 | perf_cgroup_set_timestamp(struct task_struct *task, |
479 | struct perf_event_context *ctx) | |
e5d1367f SE |
480 | { |
481 | struct perf_cgroup *cgrp; | |
482 | struct perf_cgroup_info *info; | |
483 | ||
3f7cce3c SE |
484 | /* |
485 | * ctx->lock held by caller | |
486 | * ensure we do not access cgroup data | |
487 | * unless we have the cgroup pinned (css_get) | |
488 | */ | |
489 | if (!task || !ctx->nr_cgroups) | |
e5d1367f SE |
490 | return; |
491 | ||
614e4c4e | 492 | cgrp = perf_cgroup_from_task(task, ctx); |
e5d1367f | 493 | info = this_cpu_ptr(cgrp->info); |
3f7cce3c | 494 | info->timestamp = ctx->timestamp; |
e5d1367f SE |
495 | } |
496 | ||
497 | #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ | |
498 | #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */ | |
499 | ||
500 | /* | |
501 | * reschedule events based on the cgroup constraint of task. | |
502 | * | |
503 | * mode SWOUT : schedule out everything | |
504 | * mode SWIN : schedule in based on cgroup for next | |
505 | */ | |
18ab2cd3 | 506 | static void perf_cgroup_switch(struct task_struct *task, int mode) |
e5d1367f SE |
507 | { |
508 | struct perf_cpu_context *cpuctx; | |
509 | struct pmu *pmu; | |
510 | unsigned long flags; | |
511 | ||
512 | /* | |
513 | * disable interrupts to avoid geting nr_cgroup | |
514 | * changes via __perf_event_disable(). Also | |
515 | * avoids preemption. | |
516 | */ | |
517 | local_irq_save(flags); | |
518 | ||
519 | /* | |
520 | * we reschedule only in the presence of cgroup | |
521 | * constrained events. | |
522 | */ | |
e5d1367f SE |
523 | |
524 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
e5d1367f | 525 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); |
95cf59ea PZ |
526 | if (cpuctx->unique_pmu != pmu) |
527 | continue; /* ensure we process each cpuctx once */ | |
e5d1367f | 528 | |
e5d1367f SE |
529 | /* |
530 | * perf_cgroup_events says at least one | |
531 | * context on this CPU has cgroup events. | |
532 | * | |
533 | * ctx->nr_cgroups reports the number of cgroup | |
534 | * events for a context. | |
535 | */ | |
536 | if (cpuctx->ctx.nr_cgroups > 0) { | |
facc4307 PZ |
537 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
538 | perf_pmu_disable(cpuctx->ctx.pmu); | |
e5d1367f SE |
539 | |
540 | if (mode & PERF_CGROUP_SWOUT) { | |
541 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
542 | /* | |
543 | * must not be done before ctxswout due | |
544 | * to event_filter_match() in event_sched_out() | |
545 | */ | |
546 | cpuctx->cgrp = NULL; | |
547 | } | |
548 | ||
549 | if (mode & PERF_CGROUP_SWIN) { | |
e566b76e | 550 | WARN_ON_ONCE(cpuctx->cgrp); |
95cf59ea PZ |
551 | /* |
552 | * set cgrp before ctxsw in to allow | |
553 | * event_filter_match() to not have to pass | |
554 | * task around | |
614e4c4e SE |
555 | * we pass the cpuctx->ctx to perf_cgroup_from_task() |
556 | * because cgorup events are only per-cpu | |
e5d1367f | 557 | */ |
614e4c4e | 558 | cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx); |
e5d1367f SE |
559 | cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); |
560 | } | |
facc4307 PZ |
561 | perf_pmu_enable(cpuctx->ctx.pmu); |
562 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
e5d1367f | 563 | } |
e5d1367f SE |
564 | } |
565 | ||
e5d1367f SE |
566 | local_irq_restore(flags); |
567 | } | |
568 | ||
a8d757ef SE |
569 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
570 | struct task_struct *next) | |
e5d1367f | 571 | { |
a8d757ef SE |
572 | struct perf_cgroup *cgrp1; |
573 | struct perf_cgroup *cgrp2 = NULL; | |
574 | ||
ddaaf4e2 | 575 | rcu_read_lock(); |
a8d757ef SE |
576 | /* |
577 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
578 | * we do not need to pass the ctx here because we know |
579 | * we are holding the rcu lock | |
a8d757ef | 580 | */ |
614e4c4e | 581 | cgrp1 = perf_cgroup_from_task(task, NULL); |
70a01657 | 582 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
583 | |
584 | /* | |
585 | * only schedule out current cgroup events if we know | |
586 | * that we are switching to a different cgroup. Otherwise, | |
587 | * do no touch the cgroup events. | |
588 | */ | |
589 | if (cgrp1 != cgrp2) | |
590 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
591 | |
592 | rcu_read_unlock(); | |
e5d1367f SE |
593 | } |
594 | ||
a8d757ef SE |
595 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
596 | struct task_struct *task) | |
e5d1367f | 597 | { |
a8d757ef SE |
598 | struct perf_cgroup *cgrp1; |
599 | struct perf_cgroup *cgrp2 = NULL; | |
600 | ||
ddaaf4e2 | 601 | rcu_read_lock(); |
a8d757ef SE |
602 | /* |
603 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
604 | * we do not need to pass the ctx here because we know |
605 | * we are holding the rcu lock | |
a8d757ef | 606 | */ |
614e4c4e | 607 | cgrp1 = perf_cgroup_from_task(task, NULL); |
614e4c4e | 608 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
609 | |
610 | /* | |
611 | * only need to schedule in cgroup events if we are changing | |
612 | * cgroup during ctxsw. Cgroup events were not scheduled | |
613 | * out of ctxsw out if that was not the case. | |
614 | */ | |
615 | if (cgrp1 != cgrp2) | |
616 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
617 | |
618 | rcu_read_unlock(); | |
e5d1367f SE |
619 | } |
620 | ||
621 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
622 | struct perf_event_attr *attr, | |
623 | struct perf_event *group_leader) | |
624 | { | |
625 | struct perf_cgroup *cgrp; | |
626 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
627 | struct fd f = fdget(fd); |
628 | int ret = 0; | |
e5d1367f | 629 | |
2903ff01 | 630 | if (!f.file) |
e5d1367f SE |
631 | return -EBADF; |
632 | ||
b583043e | 633 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 634 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
635 | if (IS_ERR(css)) { |
636 | ret = PTR_ERR(css); | |
637 | goto out; | |
638 | } | |
e5d1367f SE |
639 | |
640 | cgrp = container_of(css, struct perf_cgroup, css); | |
641 | event->cgrp = cgrp; | |
642 | ||
643 | /* | |
644 | * all events in a group must monitor | |
645 | * the same cgroup because a task belongs | |
646 | * to only one perf cgroup at a time | |
647 | */ | |
648 | if (group_leader && group_leader->cgrp != cgrp) { | |
649 | perf_detach_cgroup(event); | |
650 | ret = -EINVAL; | |
e5d1367f | 651 | } |
3db272c0 | 652 | out: |
2903ff01 | 653 | fdput(f); |
e5d1367f SE |
654 | return ret; |
655 | } | |
656 | ||
657 | static inline void | |
658 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
659 | { | |
660 | struct perf_cgroup_info *t; | |
661 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
662 | event->shadow_ctx_time = now - t->timestamp; | |
663 | } | |
664 | ||
665 | static inline void | |
666 | perf_cgroup_defer_enabled(struct perf_event *event) | |
667 | { | |
668 | /* | |
669 | * when the current task's perf cgroup does not match | |
670 | * the event's, we need to remember to call the | |
671 | * perf_mark_enable() function the first time a task with | |
672 | * a matching perf cgroup is scheduled in. | |
673 | */ | |
674 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
675 | event->cgrp_defer_enabled = 1; | |
676 | } | |
677 | ||
678 | static inline void | |
679 | perf_cgroup_mark_enabled(struct perf_event *event, | |
680 | struct perf_event_context *ctx) | |
681 | { | |
682 | struct perf_event *sub; | |
683 | u64 tstamp = perf_event_time(event); | |
684 | ||
685 | if (!event->cgrp_defer_enabled) | |
686 | return; | |
687 | ||
688 | event->cgrp_defer_enabled = 0; | |
689 | ||
690 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
691 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
692 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
693 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
694 | sub->cgrp_defer_enabled = 0; | |
695 | } | |
696 | } | |
697 | } | |
698 | #else /* !CONFIG_CGROUP_PERF */ | |
699 | ||
700 | static inline bool | |
701 | perf_cgroup_match(struct perf_event *event) | |
702 | { | |
703 | return true; | |
704 | } | |
705 | ||
706 | static inline void perf_detach_cgroup(struct perf_event *event) | |
707 | {} | |
708 | ||
709 | static inline int is_cgroup_event(struct perf_event *event) | |
710 | { | |
711 | return 0; | |
712 | } | |
713 | ||
714 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
715 | { | |
716 | return 0; | |
717 | } | |
718 | ||
719 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
720 | { | |
721 | } | |
722 | ||
723 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
724 | { | |
725 | } | |
726 | ||
a8d757ef SE |
727 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
728 | struct task_struct *next) | |
e5d1367f SE |
729 | { |
730 | } | |
731 | ||
a8d757ef SE |
732 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
733 | struct task_struct *task) | |
e5d1367f SE |
734 | { |
735 | } | |
736 | ||
737 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
738 | struct perf_event_attr *attr, | |
739 | struct perf_event *group_leader) | |
740 | { | |
741 | return -EINVAL; | |
742 | } | |
743 | ||
744 | static inline void | |
3f7cce3c SE |
745 | perf_cgroup_set_timestamp(struct task_struct *task, |
746 | struct perf_event_context *ctx) | |
e5d1367f SE |
747 | { |
748 | } | |
749 | ||
750 | void | |
751 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
752 | { | |
753 | } | |
754 | ||
755 | static inline void | |
756 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
757 | { | |
758 | } | |
759 | ||
760 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
761 | { | |
762 | return 0; | |
763 | } | |
764 | ||
765 | static inline void | |
766 | perf_cgroup_defer_enabled(struct perf_event *event) | |
767 | { | |
768 | } | |
769 | ||
770 | static inline void | |
771 | perf_cgroup_mark_enabled(struct perf_event *event, | |
772 | struct perf_event_context *ctx) | |
773 | { | |
774 | } | |
775 | #endif | |
776 | ||
9e630205 SE |
777 | /* |
778 | * set default to be dependent on timer tick just | |
779 | * like original code | |
780 | */ | |
781 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
782 | /* | |
783 | * function must be called with interrupts disbled | |
784 | */ | |
272325c4 | 785 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
786 | { |
787 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
788 | int rotations = 0; |
789 | ||
790 | WARN_ON(!irqs_disabled()); | |
791 | ||
792 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
793 | rotations = perf_rotate_context(cpuctx); |
794 | ||
4cfafd30 PZ |
795 | raw_spin_lock(&cpuctx->hrtimer_lock); |
796 | if (rotations) | |
9e630205 | 797 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
798 | else |
799 | cpuctx->hrtimer_active = 0; | |
800 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 801 | |
4cfafd30 | 802 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
803 | } |
804 | ||
272325c4 | 805 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 806 | { |
272325c4 | 807 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 808 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 809 | u64 interval; |
9e630205 SE |
810 | |
811 | /* no multiplexing needed for SW PMU */ | |
812 | if (pmu->task_ctx_nr == perf_sw_context) | |
813 | return; | |
814 | ||
62b85639 SE |
815 | /* |
816 | * check default is sane, if not set then force to | |
817 | * default interval (1/tick) | |
818 | */ | |
272325c4 PZ |
819 | interval = pmu->hrtimer_interval_ms; |
820 | if (interval < 1) | |
821 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 822 | |
272325c4 | 823 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 824 | |
4cfafd30 PZ |
825 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
826 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 827 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
828 | } |
829 | ||
272325c4 | 830 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 831 | { |
272325c4 | 832 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 833 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 834 | unsigned long flags; |
9e630205 SE |
835 | |
836 | /* not for SW PMU */ | |
837 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 838 | return 0; |
9e630205 | 839 | |
4cfafd30 PZ |
840 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
841 | if (!cpuctx->hrtimer_active) { | |
842 | cpuctx->hrtimer_active = 1; | |
843 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
844 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
845 | } | |
846 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 847 | |
272325c4 | 848 | return 0; |
9e630205 SE |
849 | } |
850 | ||
33696fc0 | 851 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 852 | { |
33696fc0 PZ |
853 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
854 | if (!(*count)++) | |
855 | pmu->pmu_disable(pmu); | |
9e35ad38 | 856 | } |
9e35ad38 | 857 | |
33696fc0 | 858 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 859 | { |
33696fc0 PZ |
860 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
861 | if (!--(*count)) | |
862 | pmu->pmu_enable(pmu); | |
9e35ad38 | 863 | } |
9e35ad38 | 864 | |
2fde4f94 | 865 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
866 | |
867 | /* | |
2fde4f94 MR |
868 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
869 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
870 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
871 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 872 | */ |
2fde4f94 | 873 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 874 | { |
2fde4f94 | 875 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 876 | |
e9d2b064 | 877 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 878 | |
2fde4f94 MR |
879 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
880 | ||
881 | list_add(&ctx->active_ctx_list, head); | |
882 | } | |
883 | ||
884 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
885 | { | |
886 | WARN_ON(!irqs_disabled()); | |
887 | ||
888 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
889 | ||
890 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 891 | } |
9e35ad38 | 892 | |
cdd6c482 | 893 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 894 | { |
e5289d4a | 895 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
896 | } |
897 | ||
4af57ef2 YZ |
898 | static void free_ctx(struct rcu_head *head) |
899 | { | |
900 | struct perf_event_context *ctx; | |
901 | ||
902 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
903 | kfree(ctx->task_ctx_data); | |
904 | kfree(ctx); | |
905 | } | |
906 | ||
cdd6c482 | 907 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 908 | { |
564c2b21 PM |
909 | if (atomic_dec_and_test(&ctx->refcount)) { |
910 | if (ctx->parent_ctx) | |
911 | put_ctx(ctx->parent_ctx); | |
c93f7669 PM |
912 | if (ctx->task) |
913 | put_task_struct(ctx->task); | |
4af57ef2 | 914 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 915 | } |
a63eaf34 PM |
916 | } |
917 | ||
f63a8daa PZ |
918 | /* |
919 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
920 | * perf_pmu_migrate_context() we need some magic. | |
921 | * | |
922 | * Those places that change perf_event::ctx will hold both | |
923 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
924 | * | |
8b10c5e2 PZ |
925 | * Lock ordering is by mutex address. There are two other sites where |
926 | * perf_event_context::mutex nests and those are: | |
927 | * | |
928 | * - perf_event_exit_task_context() [ child , 0 ] | |
929 | * __perf_event_exit_task() | |
930 | * sync_child_event() | |
931 | * put_event() [ parent, 1 ] | |
932 | * | |
933 | * - perf_event_init_context() [ parent, 0 ] | |
934 | * inherit_task_group() | |
935 | * inherit_group() | |
936 | * inherit_event() | |
937 | * perf_event_alloc() | |
938 | * perf_init_event() | |
939 | * perf_try_init_event() [ child , 1 ] | |
940 | * | |
941 | * While it appears there is an obvious deadlock here -- the parent and child | |
942 | * nesting levels are inverted between the two. This is in fact safe because | |
943 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
944 | * spawning task cannot (yet) exit. | |
945 | * | |
946 | * But remember that that these are parent<->child context relations, and | |
947 | * migration does not affect children, therefore these two orderings should not | |
948 | * interact. | |
f63a8daa PZ |
949 | * |
950 | * The change in perf_event::ctx does not affect children (as claimed above) | |
951 | * because the sys_perf_event_open() case will install a new event and break | |
952 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
953 | * concerned with cpuctx and that doesn't have children. | |
954 | * | |
955 | * The places that change perf_event::ctx will issue: | |
956 | * | |
957 | * perf_remove_from_context(); | |
958 | * synchronize_rcu(); | |
959 | * perf_install_in_context(); | |
960 | * | |
961 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
962 | * quiesce the event, after which we can install it in the new location. This | |
963 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
964 | * while in transit. Therefore all such accessors should also acquire | |
965 | * perf_event_context::mutex to serialize against this. | |
966 | * | |
967 | * However; because event->ctx can change while we're waiting to acquire | |
968 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
969 | * function. | |
970 | * | |
971 | * Lock order: | |
972 | * task_struct::perf_event_mutex | |
973 | * perf_event_context::mutex | |
974 | * perf_event_context::lock | |
975 | * perf_event::child_mutex; | |
976 | * perf_event::mmap_mutex | |
977 | * mmap_sem | |
978 | */ | |
a83fe28e PZ |
979 | static struct perf_event_context * |
980 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
981 | { |
982 | struct perf_event_context *ctx; | |
983 | ||
984 | again: | |
985 | rcu_read_lock(); | |
986 | ctx = ACCESS_ONCE(event->ctx); | |
987 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
988 | rcu_read_unlock(); | |
989 | goto again; | |
990 | } | |
991 | rcu_read_unlock(); | |
992 | ||
a83fe28e | 993 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
994 | if (event->ctx != ctx) { |
995 | mutex_unlock(&ctx->mutex); | |
996 | put_ctx(ctx); | |
997 | goto again; | |
998 | } | |
999 | ||
1000 | return ctx; | |
1001 | } | |
1002 | ||
a83fe28e PZ |
1003 | static inline struct perf_event_context * |
1004 | perf_event_ctx_lock(struct perf_event *event) | |
1005 | { | |
1006 | return perf_event_ctx_lock_nested(event, 0); | |
1007 | } | |
1008 | ||
f63a8daa PZ |
1009 | static void perf_event_ctx_unlock(struct perf_event *event, |
1010 | struct perf_event_context *ctx) | |
1011 | { | |
1012 | mutex_unlock(&ctx->mutex); | |
1013 | put_ctx(ctx); | |
1014 | } | |
1015 | ||
211de6eb PZ |
1016 | /* |
1017 | * This must be done under the ctx->lock, such as to serialize against | |
1018 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1019 | * calling scheduler related locks and ctx->lock nests inside those. | |
1020 | */ | |
1021 | static __must_check struct perf_event_context * | |
1022 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1023 | { |
211de6eb PZ |
1024 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1025 | ||
1026 | lockdep_assert_held(&ctx->lock); | |
1027 | ||
1028 | if (parent_ctx) | |
71a851b4 | 1029 | ctx->parent_ctx = NULL; |
5a3126d4 | 1030 | ctx->generation++; |
211de6eb PZ |
1031 | |
1032 | return parent_ctx; | |
71a851b4 PZ |
1033 | } |
1034 | ||
6844c09d ACM |
1035 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1036 | { | |
1037 | /* | |
1038 | * only top level events have the pid namespace they were created in | |
1039 | */ | |
1040 | if (event->parent) | |
1041 | event = event->parent; | |
1042 | ||
1043 | return task_tgid_nr_ns(p, event->ns); | |
1044 | } | |
1045 | ||
1046 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1047 | { | |
1048 | /* | |
1049 | * only top level events have the pid namespace they were created in | |
1050 | */ | |
1051 | if (event->parent) | |
1052 | event = event->parent; | |
1053 | ||
1054 | return task_pid_nr_ns(p, event->ns); | |
1055 | } | |
1056 | ||
7f453c24 | 1057 | /* |
cdd6c482 | 1058 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1059 | * to userspace. |
1060 | */ | |
cdd6c482 | 1061 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1062 | { |
cdd6c482 | 1063 | u64 id = event->id; |
7f453c24 | 1064 | |
cdd6c482 IM |
1065 | if (event->parent) |
1066 | id = event->parent->id; | |
7f453c24 PZ |
1067 | |
1068 | return id; | |
1069 | } | |
1070 | ||
25346b93 | 1071 | /* |
cdd6c482 | 1072 | * Get the perf_event_context for a task and lock it. |
25346b93 PM |
1073 | * This has to cope with with the fact that until it is locked, |
1074 | * the context could get moved to another task. | |
1075 | */ | |
cdd6c482 | 1076 | static struct perf_event_context * |
8dc85d54 | 1077 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1078 | { |
cdd6c482 | 1079 | struct perf_event_context *ctx; |
25346b93 | 1080 | |
9ed6060d | 1081 | retry: |
058ebd0e PZ |
1082 | /* |
1083 | * One of the few rules of preemptible RCU is that one cannot do | |
1084 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1085 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1086 | * rcu_read_unlock_special(). |
1087 | * | |
1088 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1089 | * side critical section has interrupts disabled. |
058ebd0e | 1090 | */ |
2fd59077 | 1091 | local_irq_save(*flags); |
058ebd0e | 1092 | rcu_read_lock(); |
8dc85d54 | 1093 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1094 | if (ctx) { |
1095 | /* | |
1096 | * If this context is a clone of another, it might | |
1097 | * get swapped for another underneath us by | |
cdd6c482 | 1098 | * perf_event_task_sched_out, though the |
25346b93 PM |
1099 | * rcu_read_lock() protects us from any context |
1100 | * getting freed. Lock the context and check if it | |
1101 | * got swapped before we could get the lock, and retry | |
1102 | * if so. If we locked the right context, then it | |
1103 | * can't get swapped on us any more. | |
1104 | */ | |
2fd59077 | 1105 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1106 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1107 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1108 | rcu_read_unlock(); |
2fd59077 | 1109 | local_irq_restore(*flags); |
25346b93 PM |
1110 | goto retry; |
1111 | } | |
b49a9e7e PZ |
1112 | |
1113 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1114 | raw_spin_unlock(&ctx->lock); |
b49a9e7e PZ |
1115 | ctx = NULL; |
1116 | } | |
25346b93 PM |
1117 | } |
1118 | rcu_read_unlock(); | |
2fd59077 PM |
1119 | if (!ctx) |
1120 | local_irq_restore(*flags); | |
25346b93 PM |
1121 | return ctx; |
1122 | } | |
1123 | ||
1124 | /* | |
1125 | * Get the context for a task and increment its pin_count so it | |
1126 | * can't get swapped to another task. This also increments its | |
1127 | * reference count so that the context can't get freed. | |
1128 | */ | |
8dc85d54 PZ |
1129 | static struct perf_event_context * |
1130 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1131 | { |
cdd6c482 | 1132 | struct perf_event_context *ctx; |
25346b93 PM |
1133 | unsigned long flags; |
1134 | ||
8dc85d54 | 1135 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1136 | if (ctx) { |
1137 | ++ctx->pin_count; | |
e625cce1 | 1138 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1139 | } |
1140 | return ctx; | |
1141 | } | |
1142 | ||
cdd6c482 | 1143 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1144 | { |
1145 | unsigned long flags; | |
1146 | ||
e625cce1 | 1147 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1148 | --ctx->pin_count; |
e625cce1 | 1149 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1150 | } |
1151 | ||
f67218c3 PZ |
1152 | /* |
1153 | * Update the record of the current time in a context. | |
1154 | */ | |
1155 | static void update_context_time(struct perf_event_context *ctx) | |
1156 | { | |
1157 | u64 now = perf_clock(); | |
1158 | ||
1159 | ctx->time += now - ctx->timestamp; | |
1160 | ctx->timestamp = now; | |
1161 | } | |
1162 | ||
4158755d SE |
1163 | static u64 perf_event_time(struct perf_event *event) |
1164 | { | |
1165 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1166 | |
1167 | if (is_cgroup_event(event)) | |
1168 | return perf_cgroup_event_time(event); | |
1169 | ||
4158755d SE |
1170 | return ctx ? ctx->time : 0; |
1171 | } | |
1172 | ||
f67218c3 PZ |
1173 | /* |
1174 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1175 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1176 | */ |
1177 | static void update_event_times(struct perf_event *event) | |
1178 | { | |
1179 | struct perf_event_context *ctx = event->ctx; | |
1180 | u64 run_end; | |
1181 | ||
1182 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1183 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1184 | return; | |
e5d1367f SE |
1185 | /* |
1186 | * in cgroup mode, time_enabled represents | |
1187 | * the time the event was enabled AND active | |
1188 | * tasks were in the monitored cgroup. This is | |
1189 | * independent of the activity of the context as | |
1190 | * there may be a mix of cgroup and non-cgroup events. | |
1191 | * | |
1192 | * That is why we treat cgroup events differently | |
1193 | * here. | |
1194 | */ | |
1195 | if (is_cgroup_event(event)) | |
46cd6a7f | 1196 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1197 | else if (ctx->is_active) |
1198 | run_end = ctx->time; | |
acd1d7c1 PZ |
1199 | else |
1200 | run_end = event->tstamp_stopped; | |
1201 | ||
1202 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1203 | |
1204 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1205 | run_end = event->tstamp_stopped; | |
1206 | else | |
4158755d | 1207 | run_end = perf_event_time(event); |
f67218c3 PZ |
1208 | |
1209 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1210 | |
f67218c3 PZ |
1211 | } |
1212 | ||
96c21a46 PZ |
1213 | /* |
1214 | * Update total_time_enabled and total_time_running for all events in a group. | |
1215 | */ | |
1216 | static void update_group_times(struct perf_event *leader) | |
1217 | { | |
1218 | struct perf_event *event; | |
1219 | ||
1220 | update_event_times(leader); | |
1221 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1222 | update_event_times(event); | |
1223 | } | |
1224 | ||
889ff015 FW |
1225 | static struct list_head * |
1226 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1227 | { | |
1228 | if (event->attr.pinned) | |
1229 | return &ctx->pinned_groups; | |
1230 | else | |
1231 | return &ctx->flexible_groups; | |
1232 | } | |
1233 | ||
fccc714b | 1234 | /* |
cdd6c482 | 1235 | * Add a event from the lists for its context. |
fccc714b PZ |
1236 | * Must be called with ctx->mutex and ctx->lock held. |
1237 | */ | |
04289bb9 | 1238 | static void |
cdd6c482 | 1239 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1240 | { |
c994d613 PZ |
1241 | lockdep_assert_held(&ctx->lock); |
1242 | ||
8a49542c PZ |
1243 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1244 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1245 | |
1246 | /* | |
8a49542c PZ |
1247 | * If we're a stand alone event or group leader, we go to the context |
1248 | * list, group events are kept attached to the group so that | |
1249 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1250 | */ |
8a49542c | 1251 | if (event->group_leader == event) { |
889ff015 FW |
1252 | struct list_head *list; |
1253 | ||
d6f962b5 FW |
1254 | if (is_software_event(event)) |
1255 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1256 | ||
889ff015 FW |
1257 | list = ctx_group_list(event, ctx); |
1258 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1259 | } |
592903cd | 1260 | |
08309379 | 1261 | if (is_cgroup_event(event)) |
e5d1367f | 1262 | ctx->nr_cgroups++; |
e5d1367f | 1263 | |
cdd6c482 IM |
1264 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1265 | ctx->nr_events++; | |
1266 | if (event->attr.inherit_stat) | |
bfbd3381 | 1267 | ctx->nr_stat++; |
5a3126d4 PZ |
1268 | |
1269 | ctx->generation++; | |
04289bb9 IM |
1270 | } |
1271 | ||
0231bb53 JO |
1272 | /* |
1273 | * Initialize event state based on the perf_event_attr::disabled. | |
1274 | */ | |
1275 | static inline void perf_event__state_init(struct perf_event *event) | |
1276 | { | |
1277 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1278 | PERF_EVENT_STATE_INACTIVE; | |
1279 | } | |
1280 | ||
a723968c | 1281 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1282 | { |
1283 | int entry = sizeof(u64); /* value */ | |
1284 | int size = 0; | |
1285 | int nr = 1; | |
1286 | ||
1287 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1288 | size += sizeof(u64); | |
1289 | ||
1290 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1291 | size += sizeof(u64); | |
1292 | ||
1293 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1294 | entry += sizeof(u64); | |
1295 | ||
1296 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1297 | nr += nr_siblings; |
c320c7b7 ACM |
1298 | size += sizeof(u64); |
1299 | } | |
1300 | ||
1301 | size += entry * nr; | |
1302 | event->read_size = size; | |
1303 | } | |
1304 | ||
a723968c | 1305 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1306 | { |
1307 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1308 | u16 size = 0; |
1309 | ||
c320c7b7 ACM |
1310 | if (sample_type & PERF_SAMPLE_IP) |
1311 | size += sizeof(data->ip); | |
1312 | ||
6844c09d ACM |
1313 | if (sample_type & PERF_SAMPLE_ADDR) |
1314 | size += sizeof(data->addr); | |
1315 | ||
1316 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1317 | size += sizeof(data->period); | |
1318 | ||
c3feedf2 AK |
1319 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1320 | size += sizeof(data->weight); | |
1321 | ||
6844c09d ACM |
1322 | if (sample_type & PERF_SAMPLE_READ) |
1323 | size += event->read_size; | |
1324 | ||
d6be9ad6 SE |
1325 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1326 | size += sizeof(data->data_src.val); | |
1327 | ||
fdfbbd07 AK |
1328 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1329 | size += sizeof(data->txn); | |
1330 | ||
6844c09d ACM |
1331 | event->header_size = size; |
1332 | } | |
1333 | ||
a723968c PZ |
1334 | /* |
1335 | * Called at perf_event creation and when events are attached/detached from a | |
1336 | * group. | |
1337 | */ | |
1338 | static void perf_event__header_size(struct perf_event *event) | |
1339 | { | |
1340 | __perf_event_read_size(event, | |
1341 | event->group_leader->nr_siblings); | |
1342 | __perf_event_header_size(event, event->attr.sample_type); | |
1343 | } | |
1344 | ||
6844c09d ACM |
1345 | static void perf_event__id_header_size(struct perf_event *event) |
1346 | { | |
1347 | struct perf_sample_data *data; | |
1348 | u64 sample_type = event->attr.sample_type; | |
1349 | u16 size = 0; | |
1350 | ||
c320c7b7 ACM |
1351 | if (sample_type & PERF_SAMPLE_TID) |
1352 | size += sizeof(data->tid_entry); | |
1353 | ||
1354 | if (sample_type & PERF_SAMPLE_TIME) | |
1355 | size += sizeof(data->time); | |
1356 | ||
ff3d527c AH |
1357 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1358 | size += sizeof(data->id); | |
1359 | ||
c320c7b7 ACM |
1360 | if (sample_type & PERF_SAMPLE_ID) |
1361 | size += sizeof(data->id); | |
1362 | ||
1363 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1364 | size += sizeof(data->stream_id); | |
1365 | ||
1366 | if (sample_type & PERF_SAMPLE_CPU) | |
1367 | size += sizeof(data->cpu_entry); | |
1368 | ||
6844c09d | 1369 | event->id_header_size = size; |
c320c7b7 ACM |
1370 | } |
1371 | ||
a723968c PZ |
1372 | static bool perf_event_validate_size(struct perf_event *event) |
1373 | { | |
1374 | /* | |
1375 | * The values computed here will be over-written when we actually | |
1376 | * attach the event. | |
1377 | */ | |
1378 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1379 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1380 | perf_event__id_header_size(event); | |
1381 | ||
1382 | /* | |
1383 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1384 | * Conservative limit to allow for callchains and other variable fields. | |
1385 | */ | |
1386 | if (event->read_size + event->header_size + | |
1387 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1388 | return false; | |
1389 | ||
1390 | return true; | |
1391 | } | |
1392 | ||
8a49542c PZ |
1393 | static void perf_group_attach(struct perf_event *event) |
1394 | { | |
c320c7b7 | 1395 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1396 | |
74c3337c PZ |
1397 | /* |
1398 | * We can have double attach due to group movement in perf_event_open. | |
1399 | */ | |
1400 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1401 | return; | |
1402 | ||
8a49542c PZ |
1403 | event->attach_state |= PERF_ATTACH_GROUP; |
1404 | ||
1405 | if (group_leader == event) | |
1406 | return; | |
1407 | ||
652884fe PZ |
1408 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1409 | ||
8a49542c PZ |
1410 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1411 | !is_software_event(event)) | |
1412 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1413 | ||
1414 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1415 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1416 | |
1417 | perf_event__header_size(group_leader); | |
1418 | ||
1419 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1420 | perf_event__header_size(pos); | |
8a49542c PZ |
1421 | } |
1422 | ||
a63eaf34 | 1423 | /* |
cdd6c482 | 1424 | * Remove a event from the lists for its context. |
fccc714b | 1425 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1426 | */ |
04289bb9 | 1427 | static void |
cdd6c482 | 1428 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1429 | { |
68cacd29 | 1430 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1431 | |
1432 | WARN_ON_ONCE(event->ctx != ctx); | |
1433 | lockdep_assert_held(&ctx->lock); | |
1434 | ||
8a49542c PZ |
1435 | /* |
1436 | * We can have double detach due to exit/hot-unplug + close. | |
1437 | */ | |
1438 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1439 | return; |
8a49542c PZ |
1440 | |
1441 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1442 | ||
68cacd29 | 1443 | if (is_cgroup_event(event)) { |
e5d1367f | 1444 | ctx->nr_cgroups--; |
70a01657 PZ |
1445 | /* |
1446 | * Because cgroup events are always per-cpu events, this will | |
1447 | * always be called from the right CPU. | |
1448 | */ | |
68cacd29 SE |
1449 | cpuctx = __get_cpu_context(ctx); |
1450 | /* | |
70a01657 PZ |
1451 | * If there are no more cgroup events then clear cgrp to avoid |
1452 | * stale pointer in update_cgrp_time_from_cpuctx(). | |
68cacd29 SE |
1453 | */ |
1454 | if (!ctx->nr_cgroups) | |
1455 | cpuctx->cgrp = NULL; | |
1456 | } | |
e5d1367f | 1457 | |
cdd6c482 IM |
1458 | ctx->nr_events--; |
1459 | if (event->attr.inherit_stat) | |
bfbd3381 | 1460 | ctx->nr_stat--; |
8bc20959 | 1461 | |
cdd6c482 | 1462 | list_del_rcu(&event->event_entry); |
04289bb9 | 1463 | |
8a49542c PZ |
1464 | if (event->group_leader == event) |
1465 | list_del_init(&event->group_entry); | |
5c148194 | 1466 | |
96c21a46 | 1467 | update_group_times(event); |
b2e74a26 SE |
1468 | |
1469 | /* | |
1470 | * If event was in error state, then keep it | |
1471 | * that way, otherwise bogus counts will be | |
1472 | * returned on read(). The only way to get out | |
1473 | * of error state is by explicit re-enabling | |
1474 | * of the event | |
1475 | */ | |
1476 | if (event->state > PERF_EVENT_STATE_OFF) | |
1477 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1478 | |
1479 | ctx->generation++; | |
050735b0 PZ |
1480 | } |
1481 | ||
8a49542c | 1482 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1483 | { |
1484 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1485 | struct list_head *list = NULL; |
1486 | ||
1487 | /* | |
1488 | * We can have double detach due to exit/hot-unplug + close. | |
1489 | */ | |
1490 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1491 | return; | |
1492 | ||
1493 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1494 | ||
1495 | /* | |
1496 | * If this is a sibling, remove it from its group. | |
1497 | */ | |
1498 | if (event->group_leader != event) { | |
1499 | list_del_init(&event->group_entry); | |
1500 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1501 | goto out; |
8a49542c PZ |
1502 | } |
1503 | ||
1504 | if (!list_empty(&event->group_entry)) | |
1505 | list = &event->group_entry; | |
2e2af50b | 1506 | |
04289bb9 | 1507 | /* |
cdd6c482 IM |
1508 | * If this was a group event with sibling events then |
1509 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1510 | * to whatever list we are on. |
04289bb9 | 1511 | */ |
cdd6c482 | 1512 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1513 | if (list) |
1514 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1515 | sibling->group_leader = sibling; |
d6f962b5 FW |
1516 | |
1517 | /* Inherit group flags from the previous leader */ | |
1518 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1519 | |
1520 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1521 | } |
c320c7b7 ACM |
1522 | |
1523 | out: | |
1524 | perf_event__header_size(event->group_leader); | |
1525 | ||
1526 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1527 | perf_event__header_size(tmp); | |
04289bb9 IM |
1528 | } |
1529 | ||
fadfe7be JO |
1530 | /* |
1531 | * User event without the task. | |
1532 | */ | |
1533 | static bool is_orphaned_event(struct perf_event *event) | |
1534 | { | |
1535 | return event && !is_kernel_event(event) && !event->owner; | |
1536 | } | |
1537 | ||
1538 | /* | |
1539 | * Event has a parent but parent's task finished and it's | |
1540 | * alive only because of children holding refference. | |
1541 | */ | |
1542 | static bool is_orphaned_child(struct perf_event *event) | |
1543 | { | |
1544 | return is_orphaned_event(event->parent); | |
1545 | } | |
1546 | ||
1547 | static void orphans_remove_work(struct work_struct *work); | |
1548 | ||
1549 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1550 | { | |
1551 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1552 | return; | |
1553 | ||
1554 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1555 | get_ctx(ctx); | |
1556 | ctx->orphans_remove_sched = true; | |
1557 | } | |
1558 | } | |
1559 | ||
1560 | static int __init perf_workqueue_init(void) | |
1561 | { | |
1562 | perf_wq = create_singlethread_workqueue("perf"); | |
1563 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1564 | return perf_wq ? 0 : -1; | |
1565 | } | |
1566 | ||
1567 | core_initcall(perf_workqueue_init); | |
1568 | ||
66eb579e MR |
1569 | static inline int pmu_filter_match(struct perf_event *event) |
1570 | { | |
1571 | struct pmu *pmu = event->pmu; | |
1572 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1573 | } | |
1574 | ||
fa66f07a SE |
1575 | static inline int |
1576 | event_filter_match(struct perf_event *event) | |
1577 | { | |
e5d1367f | 1578 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1579 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1580 | } |
1581 | ||
9ffcfa6f SE |
1582 | static void |
1583 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1584 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1585 | struct perf_event_context *ctx) |
3b6f9e5c | 1586 | { |
4158755d | 1587 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1588 | u64 delta; |
652884fe PZ |
1589 | |
1590 | WARN_ON_ONCE(event->ctx != ctx); | |
1591 | lockdep_assert_held(&ctx->lock); | |
1592 | ||
fa66f07a SE |
1593 | /* |
1594 | * An event which could not be activated because of | |
1595 | * filter mismatch still needs to have its timings | |
1596 | * maintained, otherwise bogus information is return | |
1597 | * via read() for time_enabled, time_running: | |
1598 | */ | |
1599 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1600 | && !event_filter_match(event)) { | |
e5d1367f | 1601 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1602 | event->tstamp_running += delta; |
4158755d | 1603 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1604 | } |
1605 | ||
cdd6c482 | 1606 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1607 | return; |
3b6f9e5c | 1608 | |
44377277 AS |
1609 | perf_pmu_disable(event->pmu); |
1610 | ||
cdd6c482 IM |
1611 | event->state = PERF_EVENT_STATE_INACTIVE; |
1612 | if (event->pending_disable) { | |
1613 | event->pending_disable = 0; | |
1614 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1615 | } |
4158755d | 1616 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1617 | event->pmu->del(event, 0); |
cdd6c482 | 1618 | event->oncpu = -1; |
3b6f9e5c | 1619 | |
cdd6c482 | 1620 | if (!is_software_event(event)) |
3b6f9e5c | 1621 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1622 | if (!--ctx->nr_active) |
1623 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1624 | if (event->attr.freq && event->attr.sample_freq) |
1625 | ctx->nr_freq--; | |
cdd6c482 | 1626 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1627 | cpuctx->exclusive = 0; |
44377277 | 1628 | |
fadfe7be JO |
1629 | if (is_orphaned_child(event)) |
1630 | schedule_orphans_remove(ctx); | |
1631 | ||
44377277 | 1632 | perf_pmu_enable(event->pmu); |
3b6f9e5c PM |
1633 | } |
1634 | ||
d859e29f | 1635 | static void |
cdd6c482 | 1636 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1637 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1638 | struct perf_event_context *ctx) |
d859e29f | 1639 | { |
cdd6c482 | 1640 | struct perf_event *event; |
fa66f07a | 1641 | int state = group_event->state; |
d859e29f | 1642 | |
cdd6c482 | 1643 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1644 | |
1645 | /* | |
1646 | * Schedule out siblings (if any): | |
1647 | */ | |
cdd6c482 IM |
1648 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1649 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1650 | |
fa66f07a | 1651 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1652 | cpuctx->exclusive = 0; |
1653 | } | |
1654 | ||
46ce0fe9 PZ |
1655 | struct remove_event { |
1656 | struct perf_event *event; | |
1657 | bool detach_group; | |
1658 | }; | |
1659 | ||
0017960f PZ |
1660 | static void ___perf_remove_from_context(void *info) |
1661 | { | |
1662 | struct remove_event *re = info; | |
1663 | struct perf_event *event = re->event; | |
1664 | struct perf_event_context *ctx = event->ctx; | |
1665 | ||
1666 | if (re->detach_group) | |
1667 | perf_group_detach(event); | |
1668 | list_del_event(event, ctx); | |
1669 | } | |
1670 | ||
0793a61d | 1671 | /* |
cdd6c482 | 1672 | * Cross CPU call to remove a performance event |
0793a61d | 1673 | * |
cdd6c482 | 1674 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1675 | * remove it from the context list. |
1676 | */ | |
fe4b04fa | 1677 | static int __perf_remove_from_context(void *info) |
0793a61d | 1678 | { |
46ce0fe9 PZ |
1679 | struct remove_event *re = info; |
1680 | struct perf_event *event = re->event; | |
cdd6c482 | 1681 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1682 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
0793a61d | 1683 | |
e625cce1 | 1684 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 1685 | event_sched_out(event, cpuctx, ctx); |
46ce0fe9 PZ |
1686 | if (re->detach_group) |
1687 | perf_group_detach(event); | |
cdd6c482 | 1688 | list_del_event(event, ctx); |
64ce3126 PZ |
1689 | if (!ctx->nr_events && cpuctx->task_ctx == ctx) { |
1690 | ctx->is_active = 0; | |
1691 | cpuctx->task_ctx = NULL; | |
1692 | } | |
e625cce1 | 1693 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1694 | |
1695 | return 0; | |
0793a61d TG |
1696 | } |
1697 | ||
0793a61d | 1698 | /* |
cdd6c482 | 1699 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1700 | * |
cdd6c482 | 1701 | * CPU events are removed with a smp call. For task events we only |
0793a61d | 1702 | * call when the task is on a CPU. |
c93f7669 | 1703 | * |
cdd6c482 IM |
1704 | * If event->ctx is a cloned context, callers must make sure that |
1705 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1706 | * remains valid. This is OK when called from perf_release since |
1707 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1708 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1709 | * context has been detached from its task. |
0793a61d | 1710 | */ |
46ce0fe9 | 1711 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1712 | { |
cdd6c482 | 1713 | struct perf_event_context *ctx = event->ctx; |
46ce0fe9 PZ |
1714 | struct remove_event re = { |
1715 | .event = event, | |
1716 | .detach_group = detach_group, | |
1717 | }; | |
0793a61d | 1718 | |
fe4b04fa PZ |
1719 | lockdep_assert_held(&ctx->mutex); |
1720 | ||
0017960f PZ |
1721 | event_function_call(event, __perf_remove_from_context, |
1722 | ___perf_remove_from_context, &re); | |
0793a61d TG |
1723 | } |
1724 | ||
d859e29f | 1725 | /* |
cdd6c482 | 1726 | * Cross CPU call to disable a performance event |
d859e29f | 1727 | */ |
500ad2d8 | 1728 | int __perf_event_disable(void *info) |
d859e29f | 1729 | { |
cdd6c482 | 1730 | struct perf_event *event = info; |
cdd6c482 | 1731 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1732 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f PM |
1733 | |
1734 | /* | |
cdd6c482 IM |
1735 | * If this is a per-task event, need to check whether this |
1736 | * event's task is the current task on this cpu. | |
fe4b04fa PZ |
1737 | * |
1738 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1739 | * flipping contexts around. | |
d859e29f | 1740 | */ |
665c2142 | 1741 | if (ctx->task && cpuctx->task_ctx != ctx) |
fe4b04fa | 1742 | return -EINVAL; |
d859e29f | 1743 | |
e625cce1 | 1744 | raw_spin_lock(&ctx->lock); |
d859e29f PM |
1745 | |
1746 | /* | |
cdd6c482 | 1747 | * If the event is on, turn it off. |
d859e29f PM |
1748 | * If it is in error state, leave it in error state. |
1749 | */ | |
cdd6c482 | 1750 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
4af4998b | 1751 | update_context_time(ctx); |
e5d1367f | 1752 | update_cgrp_time_from_event(event); |
cdd6c482 IM |
1753 | update_group_times(event); |
1754 | if (event == event->group_leader) | |
1755 | group_sched_out(event, cpuctx, ctx); | |
d859e29f | 1756 | else |
cdd6c482 IM |
1757 | event_sched_out(event, cpuctx, ctx); |
1758 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f PM |
1759 | } |
1760 | ||
e625cce1 | 1761 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1762 | |
1763 | return 0; | |
d859e29f PM |
1764 | } |
1765 | ||
7b648018 PZ |
1766 | void ___perf_event_disable(void *info) |
1767 | { | |
1768 | struct perf_event *event = info; | |
1769 | ||
1770 | /* | |
1771 | * Since we have the lock this context can't be scheduled | |
1772 | * in, so we can change the state safely. | |
1773 | */ | |
1774 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
1775 | update_group_times(event); | |
1776 | event->state = PERF_EVENT_STATE_OFF; | |
1777 | } | |
1778 | } | |
1779 | ||
d859e29f | 1780 | /* |
cdd6c482 | 1781 | * Disable a event. |
c93f7669 | 1782 | * |
cdd6c482 IM |
1783 | * If event->ctx is a cloned context, callers must make sure that |
1784 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1785 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1786 | * perf_event_for_each_child or perf_event_for_each because they |
1787 | * hold the top-level event's child_mutex, so any descendant that | |
1788 | * goes to exit will block in sync_child_event. | |
1789 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1790 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1791 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1792 | */ |
f63a8daa | 1793 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1794 | { |
cdd6c482 | 1795 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1796 | |
e625cce1 | 1797 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1798 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1799 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1800 | return; |
53cfbf59 | 1801 | } |
e625cce1 | 1802 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 PZ |
1803 | |
1804 | event_function_call(event, __perf_event_disable, | |
1805 | ___perf_event_disable, event); | |
d859e29f | 1806 | } |
f63a8daa PZ |
1807 | |
1808 | /* | |
1809 | * Strictly speaking kernel users cannot create groups and therefore this | |
1810 | * interface does not need the perf_event_ctx_lock() magic. | |
1811 | */ | |
1812 | void perf_event_disable(struct perf_event *event) | |
1813 | { | |
1814 | struct perf_event_context *ctx; | |
1815 | ||
1816 | ctx = perf_event_ctx_lock(event); | |
1817 | _perf_event_disable(event); | |
1818 | perf_event_ctx_unlock(event, ctx); | |
1819 | } | |
dcfce4a0 | 1820 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1821 | |
e5d1367f SE |
1822 | static void perf_set_shadow_time(struct perf_event *event, |
1823 | struct perf_event_context *ctx, | |
1824 | u64 tstamp) | |
1825 | { | |
1826 | /* | |
1827 | * use the correct time source for the time snapshot | |
1828 | * | |
1829 | * We could get by without this by leveraging the | |
1830 | * fact that to get to this function, the caller | |
1831 | * has most likely already called update_context_time() | |
1832 | * and update_cgrp_time_xx() and thus both timestamp | |
1833 | * are identical (or very close). Given that tstamp is, | |
1834 | * already adjusted for cgroup, we could say that: | |
1835 | * tstamp - ctx->timestamp | |
1836 | * is equivalent to | |
1837 | * tstamp - cgrp->timestamp. | |
1838 | * | |
1839 | * Then, in perf_output_read(), the calculation would | |
1840 | * work with no changes because: | |
1841 | * - event is guaranteed scheduled in | |
1842 | * - no scheduled out in between | |
1843 | * - thus the timestamp would be the same | |
1844 | * | |
1845 | * But this is a bit hairy. | |
1846 | * | |
1847 | * So instead, we have an explicit cgroup call to remain | |
1848 | * within the time time source all along. We believe it | |
1849 | * is cleaner and simpler to understand. | |
1850 | */ | |
1851 | if (is_cgroup_event(event)) | |
1852 | perf_cgroup_set_shadow_time(event, tstamp); | |
1853 | else | |
1854 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1855 | } | |
1856 | ||
4fe757dd PZ |
1857 | #define MAX_INTERRUPTS (~0ULL) |
1858 | ||
1859 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1860 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1861 | |
235c7fc7 | 1862 | static int |
9ffcfa6f | 1863 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1864 | struct perf_cpu_context *cpuctx, |
6e37738a | 1865 | struct perf_event_context *ctx) |
235c7fc7 | 1866 | { |
4158755d | 1867 | u64 tstamp = perf_event_time(event); |
44377277 | 1868 | int ret = 0; |
4158755d | 1869 | |
63342411 PZ |
1870 | lockdep_assert_held(&ctx->lock); |
1871 | ||
cdd6c482 | 1872 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1873 | return 0; |
1874 | ||
cdd6c482 | 1875 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1876 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1877 | |
1878 | /* | |
1879 | * Unthrottle events, since we scheduled we might have missed several | |
1880 | * ticks already, also for a heavily scheduling task there is little | |
1881 | * guarantee it'll get a tick in a timely manner. | |
1882 | */ | |
1883 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1884 | perf_log_throttle(event, 1); | |
1885 | event->hw.interrupts = 0; | |
1886 | } | |
1887 | ||
235c7fc7 IM |
1888 | /* |
1889 | * The new state must be visible before we turn it on in the hardware: | |
1890 | */ | |
1891 | smp_wmb(); | |
1892 | ||
44377277 AS |
1893 | perf_pmu_disable(event->pmu); |
1894 | ||
72f669c0 SL |
1895 | perf_set_shadow_time(event, ctx, tstamp); |
1896 | ||
ec0d7729 AS |
1897 | perf_log_itrace_start(event); |
1898 | ||
a4eaf7f1 | 1899 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1900 | event->state = PERF_EVENT_STATE_INACTIVE; |
1901 | event->oncpu = -1; | |
44377277 AS |
1902 | ret = -EAGAIN; |
1903 | goto out; | |
235c7fc7 IM |
1904 | } |
1905 | ||
00a2916f PZ |
1906 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1907 | ||
cdd6c482 | 1908 | if (!is_software_event(event)) |
3b6f9e5c | 1909 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1910 | if (!ctx->nr_active++) |
1911 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1912 | if (event->attr.freq && event->attr.sample_freq) |
1913 | ctx->nr_freq++; | |
235c7fc7 | 1914 | |
cdd6c482 | 1915 | if (event->attr.exclusive) |
3b6f9e5c PM |
1916 | cpuctx->exclusive = 1; |
1917 | ||
fadfe7be JO |
1918 | if (is_orphaned_child(event)) |
1919 | schedule_orphans_remove(ctx); | |
1920 | ||
44377277 AS |
1921 | out: |
1922 | perf_pmu_enable(event->pmu); | |
1923 | ||
1924 | return ret; | |
235c7fc7 IM |
1925 | } |
1926 | ||
6751b71e | 1927 | static int |
cdd6c482 | 1928 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1929 | struct perf_cpu_context *cpuctx, |
6e37738a | 1930 | struct perf_event_context *ctx) |
6751b71e | 1931 | { |
6bde9b6c | 1932 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1933 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1934 | u64 now = ctx->time; |
1935 | bool simulate = false; | |
6751b71e | 1936 | |
cdd6c482 | 1937 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1938 | return 0; |
1939 | ||
fbbe0701 | 1940 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1941 | |
9ffcfa6f | 1942 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1943 | pmu->cancel_txn(pmu); |
272325c4 | 1944 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1945 | return -EAGAIN; |
90151c35 | 1946 | } |
6751b71e PM |
1947 | |
1948 | /* | |
1949 | * Schedule in siblings as one group (if any): | |
1950 | */ | |
cdd6c482 | 1951 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1952 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1953 | partial_group = event; |
6751b71e PM |
1954 | goto group_error; |
1955 | } | |
1956 | } | |
1957 | ||
9ffcfa6f | 1958 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1959 | return 0; |
9ffcfa6f | 1960 | |
6751b71e PM |
1961 | group_error: |
1962 | /* | |
1963 | * Groups can be scheduled in as one unit only, so undo any | |
1964 | * partial group before returning: | |
d7842da4 SE |
1965 | * The events up to the failed event are scheduled out normally, |
1966 | * tstamp_stopped will be updated. | |
1967 | * | |
1968 | * The failed events and the remaining siblings need to have | |
1969 | * their timings updated as if they had gone thru event_sched_in() | |
1970 | * and event_sched_out(). This is required to get consistent timings | |
1971 | * across the group. This also takes care of the case where the group | |
1972 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1973 | * the time the event was actually stopped, such that time delta | |
1974 | * calculation in update_event_times() is correct. | |
6751b71e | 1975 | */ |
cdd6c482 IM |
1976 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
1977 | if (event == partial_group) | |
d7842da4 SE |
1978 | simulate = true; |
1979 | ||
1980 | if (simulate) { | |
1981 | event->tstamp_running += now - event->tstamp_stopped; | |
1982 | event->tstamp_stopped = now; | |
1983 | } else { | |
1984 | event_sched_out(event, cpuctx, ctx); | |
1985 | } | |
6751b71e | 1986 | } |
9ffcfa6f | 1987 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 1988 | |
ad5133b7 | 1989 | pmu->cancel_txn(pmu); |
90151c35 | 1990 | |
272325c4 | 1991 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 1992 | |
6751b71e PM |
1993 | return -EAGAIN; |
1994 | } | |
1995 | ||
3b6f9e5c | 1996 | /* |
cdd6c482 | 1997 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 1998 | */ |
cdd6c482 | 1999 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2000 | struct perf_cpu_context *cpuctx, |
2001 | int can_add_hw) | |
2002 | { | |
2003 | /* | |
cdd6c482 | 2004 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2005 | */ |
d6f962b5 | 2006 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2007 | return 1; |
2008 | /* | |
2009 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2010 | * events can go on. |
3b6f9e5c PM |
2011 | */ |
2012 | if (cpuctx->exclusive) | |
2013 | return 0; | |
2014 | /* | |
2015 | * If this group is exclusive and there are already | |
cdd6c482 | 2016 | * events on the CPU, it can't go on. |
3b6f9e5c | 2017 | */ |
cdd6c482 | 2018 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2019 | return 0; |
2020 | /* | |
2021 | * Otherwise, try to add it if all previous groups were able | |
2022 | * to go on. | |
2023 | */ | |
2024 | return can_add_hw; | |
2025 | } | |
2026 | ||
cdd6c482 IM |
2027 | static void add_event_to_ctx(struct perf_event *event, |
2028 | struct perf_event_context *ctx) | |
53cfbf59 | 2029 | { |
4158755d SE |
2030 | u64 tstamp = perf_event_time(event); |
2031 | ||
cdd6c482 | 2032 | list_add_event(event, ctx); |
8a49542c | 2033 | perf_group_attach(event); |
4158755d SE |
2034 | event->tstamp_enabled = tstamp; |
2035 | event->tstamp_running = tstamp; | |
2036 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2037 | } |
2038 | ||
3e349507 PZ |
2039 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2040 | struct perf_event_context *ctx); | |
2c29ef0f PZ |
2041 | static void |
2042 | ctx_sched_in(struct perf_event_context *ctx, | |
2043 | struct perf_cpu_context *cpuctx, | |
2044 | enum event_type_t event_type, | |
2045 | struct task_struct *task); | |
fe4b04fa | 2046 | |
dce5855b PZ |
2047 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2048 | struct perf_event_context *ctx, | |
2049 | struct task_struct *task) | |
2050 | { | |
2051 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2052 | if (ctx) | |
2053 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2054 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2055 | if (ctx) | |
2056 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2057 | } | |
2058 | ||
0017960f PZ |
2059 | static void ___perf_install_in_context(void *info) |
2060 | { | |
2061 | struct perf_event *event = info; | |
2062 | struct perf_event_context *ctx = event->ctx; | |
2063 | ||
2064 | /* | |
2065 | * Since the task isn't running, its safe to add the event, us holding | |
2066 | * the ctx->lock ensures the task won't get scheduled in. | |
2067 | */ | |
2068 | add_event_to_ctx(event, ctx); | |
2069 | } | |
2070 | ||
3e349507 PZ |
2071 | static void ctx_resched(struct perf_cpu_context *cpuctx, |
2072 | struct perf_event_context *task_ctx) | |
2073 | { | |
2074 | perf_pmu_disable(cpuctx->ctx.pmu); | |
2075 | if (task_ctx) | |
2076 | task_ctx_sched_out(cpuctx, task_ctx); | |
2077 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); | |
2078 | perf_event_sched_in(cpuctx, task_ctx, current); | |
2079 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2080 | } | |
2081 | ||
0793a61d | 2082 | /* |
cdd6c482 | 2083 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2084 | * |
2085 | * Must be called with ctx->mutex held | |
0793a61d | 2086 | */ |
fe4b04fa | 2087 | static int __perf_install_in_context(void *info) |
0793a61d | 2088 | { |
cdd6c482 IM |
2089 | struct perf_event *event = info; |
2090 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2091 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f PZ |
2092 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
2093 | struct task_struct *task = current; | |
2094 | ||
b58f6b0d | 2095 | perf_ctx_lock(cpuctx, task_ctx); |
2c29ef0f | 2096 | perf_pmu_disable(cpuctx->ctx.pmu); |
0793a61d TG |
2097 | |
2098 | /* | |
2c29ef0f | 2099 | * If there was an active task_ctx schedule it out. |
0793a61d | 2100 | */ |
b58f6b0d | 2101 | if (task_ctx) |
3e349507 | 2102 | task_ctx_sched_out(cpuctx, task_ctx); |
b58f6b0d PZ |
2103 | |
2104 | /* | |
2105 | * If the context we're installing events in is not the | |
2106 | * active task_ctx, flip them. | |
2107 | */ | |
2108 | if (ctx->task && task_ctx != ctx) { | |
2109 | if (task_ctx) | |
2110 | raw_spin_unlock(&task_ctx->lock); | |
2111 | raw_spin_lock(&ctx->lock); | |
2112 | task_ctx = ctx; | |
2113 | } | |
2114 | ||
2115 | if (task_ctx) { | |
2116 | cpuctx->task_ctx = task_ctx; | |
2c29ef0f PZ |
2117 | task = task_ctx->task; |
2118 | } | |
b58f6b0d | 2119 | |
2c29ef0f | 2120 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); |
0793a61d | 2121 | |
4af4998b | 2122 | update_context_time(ctx); |
e5d1367f SE |
2123 | /* |
2124 | * update cgrp time only if current cgrp | |
2125 | * matches event->cgrp. Must be done before | |
2126 | * calling add_event_to_ctx() | |
2127 | */ | |
2128 | update_cgrp_time_from_event(event); | |
0793a61d | 2129 | |
cdd6c482 | 2130 | add_event_to_ctx(event, ctx); |
0793a61d | 2131 | |
d859e29f | 2132 | /* |
2c29ef0f | 2133 | * Schedule everything back in |
d859e29f | 2134 | */ |
dce5855b | 2135 | perf_event_sched_in(cpuctx, task_ctx, task); |
2c29ef0f PZ |
2136 | |
2137 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2138 | perf_ctx_unlock(cpuctx, task_ctx); | |
fe4b04fa PZ |
2139 | |
2140 | return 0; | |
0793a61d TG |
2141 | } |
2142 | ||
2143 | /* | |
cdd6c482 | 2144 | * Attach a performance event to a context |
0793a61d TG |
2145 | */ |
2146 | static void | |
cdd6c482 IM |
2147 | perf_install_in_context(struct perf_event_context *ctx, |
2148 | struct perf_event *event, | |
0793a61d TG |
2149 | int cpu) |
2150 | { | |
fe4b04fa PZ |
2151 | lockdep_assert_held(&ctx->mutex); |
2152 | ||
c3f00c70 | 2153 | event->ctx = ctx; |
0cda4c02 YZ |
2154 | if (event->cpu != -1) |
2155 | event->cpu = cpu; | |
c3f00c70 | 2156 | |
0017960f PZ |
2157 | event_function_call(event, __perf_install_in_context, |
2158 | ___perf_install_in_context, event); | |
0793a61d TG |
2159 | } |
2160 | ||
fa289bec | 2161 | /* |
cdd6c482 | 2162 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2163 | * Enabling the leader of a group effectively enables all |
2164 | * the group members that aren't explicitly disabled, so we | |
2165 | * have to update their ->tstamp_enabled also. | |
2166 | * Note: this works for group members as well as group leaders | |
2167 | * since the non-leader members' sibling_lists will be empty. | |
2168 | */ | |
1d9b482e | 2169 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2170 | { |
cdd6c482 | 2171 | struct perf_event *sub; |
4158755d | 2172 | u64 tstamp = perf_event_time(event); |
fa289bec | 2173 | |
cdd6c482 | 2174 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2175 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2176 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2177 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2178 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2179 | } |
fa289bec PM |
2180 | } |
2181 | ||
d859e29f | 2182 | /* |
cdd6c482 | 2183 | * Cross CPU call to enable a performance event |
d859e29f | 2184 | */ |
fe4b04fa | 2185 | static int __perf_event_enable(void *info) |
04289bb9 | 2186 | { |
cdd6c482 | 2187 | struct perf_event *event = info; |
cdd6c482 IM |
2188 | struct perf_event_context *ctx = event->ctx; |
2189 | struct perf_event *leader = event->group_leader; | |
108b02cf | 2190 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
aee7dbc4 | 2191 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
04289bb9 | 2192 | |
06f41796 JO |
2193 | /* |
2194 | * There's a time window between 'ctx->is_active' check | |
2195 | * in perf_event_enable function and this place having: | |
2196 | * - IRQs on | |
2197 | * - ctx->lock unlocked | |
2198 | * | |
2199 | * where the task could be killed and 'ctx' deactivated | |
2200 | * by perf_event_exit_task. | |
2201 | */ | |
2202 | if (!ctx->is_active) | |
fe4b04fa | 2203 | return -EINVAL; |
3cbed429 | 2204 | |
aee7dbc4 PZ |
2205 | perf_ctx_lock(cpuctx, task_ctx); |
2206 | WARN_ON_ONCE(&cpuctx->ctx != ctx && task_ctx != ctx); | |
4af4998b | 2207 | update_context_time(ctx); |
d859e29f | 2208 | |
cdd6c482 | 2209 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f | 2210 | goto unlock; |
e5d1367f SE |
2211 | |
2212 | /* | |
2213 | * set current task's cgroup time reference point | |
2214 | */ | |
3f7cce3c | 2215 | perf_cgroup_set_timestamp(current, ctx); |
e5d1367f | 2216 | |
1d9b482e | 2217 | __perf_event_mark_enabled(event); |
04289bb9 | 2218 | |
e5d1367f SE |
2219 | if (!event_filter_match(event)) { |
2220 | if (is_cgroup_event(event)) | |
2221 | perf_cgroup_defer_enabled(event); | |
f4c4176f | 2222 | goto unlock; |
e5d1367f | 2223 | } |
f4c4176f | 2224 | |
04289bb9 | 2225 | /* |
cdd6c482 | 2226 | * If the event is in a group and isn't the group leader, |
d859e29f | 2227 | * then don't put it on unless the group is on. |
04289bb9 | 2228 | */ |
cdd6c482 | 2229 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
d859e29f | 2230 | goto unlock; |
3b6f9e5c | 2231 | |
aee7dbc4 | 2232 | ctx_resched(cpuctx, task_ctx); |
d859e29f | 2233 | |
9ed6060d | 2234 | unlock: |
aee7dbc4 | 2235 | perf_ctx_unlock(cpuctx, task_ctx); |
fe4b04fa PZ |
2236 | |
2237 | return 0; | |
d859e29f PM |
2238 | } |
2239 | ||
7b648018 PZ |
2240 | void ___perf_event_enable(void *info) |
2241 | { | |
2242 | __perf_event_mark_enabled((struct perf_event *)info); | |
2243 | } | |
2244 | ||
d859e29f | 2245 | /* |
cdd6c482 | 2246 | * Enable a event. |
c93f7669 | 2247 | * |
cdd6c482 IM |
2248 | * If event->ctx is a cloned context, callers must make sure that |
2249 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2250 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2251 | * perf_event_for_each_child or perf_event_for_each as described |
2252 | * for perf_event_disable. | |
d859e29f | 2253 | */ |
f63a8daa | 2254 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2255 | { |
cdd6c482 | 2256 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2257 | |
7b648018 PZ |
2258 | raw_spin_lock_irq(&ctx->lock); |
2259 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
2260 | raw_spin_unlock_irq(&ctx->lock); | |
d859e29f PM |
2261 | return; |
2262 | } | |
2263 | ||
d859e29f | 2264 | /* |
cdd6c482 | 2265 | * If the event is in error state, clear that first. |
7b648018 PZ |
2266 | * |
2267 | * That way, if we see the event in error state below, we know that it | |
2268 | * has gone back into error state, as distinct from the task having | |
2269 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2270 | */ |
cdd6c482 IM |
2271 | if (event->state == PERF_EVENT_STATE_ERROR) |
2272 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2273 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2274 | |
7b648018 PZ |
2275 | event_function_call(event, __perf_event_enable, |
2276 | ___perf_event_enable, event); | |
d859e29f | 2277 | } |
f63a8daa PZ |
2278 | |
2279 | /* | |
2280 | * See perf_event_disable(); | |
2281 | */ | |
2282 | void perf_event_enable(struct perf_event *event) | |
2283 | { | |
2284 | struct perf_event_context *ctx; | |
2285 | ||
2286 | ctx = perf_event_ctx_lock(event); | |
2287 | _perf_event_enable(event); | |
2288 | perf_event_ctx_unlock(event, ctx); | |
2289 | } | |
dcfce4a0 | 2290 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2291 | |
f63a8daa | 2292 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2293 | { |
2023b359 | 2294 | /* |
cdd6c482 | 2295 | * not supported on inherited events |
2023b359 | 2296 | */ |
2e939d1d | 2297 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2298 | return -EINVAL; |
2299 | ||
cdd6c482 | 2300 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2301 | _perf_event_enable(event); |
2023b359 PZ |
2302 | |
2303 | return 0; | |
79f14641 | 2304 | } |
f63a8daa PZ |
2305 | |
2306 | /* | |
2307 | * See perf_event_disable() | |
2308 | */ | |
2309 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2310 | { | |
2311 | struct perf_event_context *ctx; | |
2312 | int ret; | |
2313 | ||
2314 | ctx = perf_event_ctx_lock(event); | |
2315 | ret = _perf_event_refresh(event, refresh); | |
2316 | perf_event_ctx_unlock(event, ctx); | |
2317 | ||
2318 | return ret; | |
2319 | } | |
26ca5c11 | 2320 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2321 | |
5b0311e1 FW |
2322 | static void ctx_sched_out(struct perf_event_context *ctx, |
2323 | struct perf_cpu_context *cpuctx, | |
2324 | enum event_type_t event_type) | |
235c7fc7 | 2325 | { |
db24d33e | 2326 | int is_active = ctx->is_active; |
c994d613 PZ |
2327 | struct perf_event *event; |
2328 | ||
2329 | lockdep_assert_held(&ctx->lock); | |
235c7fc7 | 2330 | |
db24d33e | 2331 | ctx->is_active &= ~event_type; |
63e30d3e PZ |
2332 | if (ctx->task) { |
2333 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2334 | if (!ctx->is_active) | |
2335 | cpuctx->task_ctx = NULL; | |
2336 | } | |
2337 | ||
cdd6c482 | 2338 | if (likely(!ctx->nr_events)) |
facc4307 PZ |
2339 | return; |
2340 | ||
4af4998b | 2341 | update_context_time(ctx); |
e5d1367f | 2342 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2343 | if (!ctx->nr_active) |
facc4307 | 2344 | return; |
5b0311e1 | 2345 | |
075e0b00 | 2346 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2347 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2348 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2349 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2350 | } |
889ff015 | 2351 | |
db24d33e | 2352 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2353 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2354 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2355 | } |
1b9a644f | 2356 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2357 | } |
2358 | ||
564c2b21 | 2359 | /* |
5a3126d4 PZ |
2360 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2361 | * cloned from the same version of the same context. | |
2362 | * | |
2363 | * Equivalence is measured using a generation number in the context that is | |
2364 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2365 | * and list_del_event(). | |
564c2b21 | 2366 | */ |
cdd6c482 IM |
2367 | static int context_equiv(struct perf_event_context *ctx1, |
2368 | struct perf_event_context *ctx2) | |
564c2b21 | 2369 | { |
211de6eb PZ |
2370 | lockdep_assert_held(&ctx1->lock); |
2371 | lockdep_assert_held(&ctx2->lock); | |
2372 | ||
5a3126d4 PZ |
2373 | /* Pinning disables the swap optimization */ |
2374 | if (ctx1->pin_count || ctx2->pin_count) | |
2375 | return 0; | |
2376 | ||
2377 | /* If ctx1 is the parent of ctx2 */ | |
2378 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2379 | return 1; | |
2380 | ||
2381 | /* If ctx2 is the parent of ctx1 */ | |
2382 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2383 | return 1; | |
2384 | ||
2385 | /* | |
2386 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2387 | * hierarchy, see perf_event_init_context(). | |
2388 | */ | |
2389 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2390 | ctx1->parent_gen == ctx2->parent_gen) | |
2391 | return 1; | |
2392 | ||
2393 | /* Unmatched */ | |
2394 | return 0; | |
564c2b21 PM |
2395 | } |
2396 | ||
cdd6c482 IM |
2397 | static void __perf_event_sync_stat(struct perf_event *event, |
2398 | struct perf_event *next_event) | |
bfbd3381 PZ |
2399 | { |
2400 | u64 value; | |
2401 | ||
cdd6c482 | 2402 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2403 | return; |
2404 | ||
2405 | /* | |
cdd6c482 | 2406 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2407 | * because we're in the middle of a context switch and have IRQs |
2408 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2409 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2410 | * don't need to use it. |
2411 | */ | |
cdd6c482 IM |
2412 | switch (event->state) { |
2413 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2414 | event->pmu->read(event); |
2415 | /* fall-through */ | |
bfbd3381 | 2416 | |
cdd6c482 IM |
2417 | case PERF_EVENT_STATE_INACTIVE: |
2418 | update_event_times(event); | |
bfbd3381 PZ |
2419 | break; |
2420 | ||
2421 | default: | |
2422 | break; | |
2423 | } | |
2424 | ||
2425 | /* | |
cdd6c482 | 2426 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2427 | * values when we flip the contexts. |
2428 | */ | |
e7850595 PZ |
2429 | value = local64_read(&next_event->count); |
2430 | value = local64_xchg(&event->count, value); | |
2431 | local64_set(&next_event->count, value); | |
bfbd3381 | 2432 | |
cdd6c482 IM |
2433 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2434 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2435 | |
bfbd3381 | 2436 | /* |
19d2e755 | 2437 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2438 | */ |
cdd6c482 IM |
2439 | perf_event_update_userpage(event); |
2440 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2441 | } |
2442 | ||
cdd6c482 IM |
2443 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2444 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2445 | { |
cdd6c482 | 2446 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2447 | |
2448 | if (!ctx->nr_stat) | |
2449 | return; | |
2450 | ||
02ffdbc8 PZ |
2451 | update_context_time(ctx); |
2452 | ||
cdd6c482 IM |
2453 | event = list_first_entry(&ctx->event_list, |
2454 | struct perf_event, event_entry); | |
bfbd3381 | 2455 | |
cdd6c482 IM |
2456 | next_event = list_first_entry(&next_ctx->event_list, |
2457 | struct perf_event, event_entry); | |
bfbd3381 | 2458 | |
cdd6c482 IM |
2459 | while (&event->event_entry != &ctx->event_list && |
2460 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2461 | |
cdd6c482 | 2462 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2463 | |
cdd6c482 IM |
2464 | event = list_next_entry(event, event_entry); |
2465 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2466 | } |
2467 | } | |
2468 | ||
fe4b04fa PZ |
2469 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2470 | struct task_struct *next) | |
0793a61d | 2471 | { |
8dc85d54 | 2472 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2473 | struct perf_event_context *next_ctx; |
5a3126d4 | 2474 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2475 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2476 | int do_switch = 1; |
0793a61d | 2477 | |
108b02cf PZ |
2478 | if (likely(!ctx)) |
2479 | return; | |
10989fb2 | 2480 | |
108b02cf PZ |
2481 | cpuctx = __get_cpu_context(ctx); |
2482 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2483 | return; |
2484 | ||
c93f7669 | 2485 | rcu_read_lock(); |
8dc85d54 | 2486 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2487 | if (!next_ctx) |
2488 | goto unlock; | |
2489 | ||
2490 | parent = rcu_dereference(ctx->parent_ctx); | |
2491 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2492 | ||
2493 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2494 | if (!parent && !next_parent) |
5a3126d4 PZ |
2495 | goto unlock; |
2496 | ||
2497 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2498 | /* |
2499 | * Looks like the two contexts are clones, so we might be | |
2500 | * able to optimize the context switch. We lock both | |
2501 | * contexts and check that they are clones under the | |
2502 | * lock (including re-checking that neither has been | |
2503 | * uncloned in the meantime). It doesn't matter which | |
2504 | * order we take the locks because no other cpu could | |
2505 | * be trying to lock both of these tasks. | |
2506 | */ | |
e625cce1 TG |
2507 | raw_spin_lock(&ctx->lock); |
2508 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2509 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2510 | /* |
2511 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2512 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2513 | */ |
8dc85d54 PZ |
2514 | task->perf_event_ctxp[ctxn] = next_ctx; |
2515 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2516 | ctx->task = next; |
2517 | next_ctx->task = task; | |
5a158c3c YZ |
2518 | |
2519 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2520 | ||
c93f7669 | 2521 | do_switch = 0; |
bfbd3381 | 2522 | |
cdd6c482 | 2523 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2524 | } |
e625cce1 TG |
2525 | raw_spin_unlock(&next_ctx->lock); |
2526 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2527 | } |
5a3126d4 | 2528 | unlock: |
c93f7669 | 2529 | rcu_read_unlock(); |
564c2b21 | 2530 | |
c93f7669 | 2531 | if (do_switch) { |
facc4307 | 2532 | raw_spin_lock(&ctx->lock); |
8833d0e2 | 2533 | task_ctx_sched_out(cpuctx, ctx); |
facc4307 | 2534 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2535 | } |
0793a61d TG |
2536 | } |
2537 | ||
ba532500 YZ |
2538 | void perf_sched_cb_dec(struct pmu *pmu) |
2539 | { | |
2540 | this_cpu_dec(perf_sched_cb_usages); | |
2541 | } | |
2542 | ||
2543 | void perf_sched_cb_inc(struct pmu *pmu) | |
2544 | { | |
2545 | this_cpu_inc(perf_sched_cb_usages); | |
2546 | } | |
2547 | ||
2548 | /* | |
2549 | * This function provides the context switch callback to the lower code | |
2550 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2551 | */ | |
2552 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2553 | struct task_struct *next, | |
2554 | bool sched_in) | |
2555 | { | |
2556 | struct perf_cpu_context *cpuctx; | |
2557 | struct pmu *pmu; | |
2558 | unsigned long flags; | |
2559 | ||
2560 | if (prev == next) | |
2561 | return; | |
2562 | ||
2563 | local_irq_save(flags); | |
2564 | ||
2565 | rcu_read_lock(); | |
2566 | ||
2567 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2568 | if (pmu->sched_task) { | |
2569 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2570 | ||
2571 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2572 | ||
2573 | perf_pmu_disable(pmu); | |
2574 | ||
2575 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2576 | ||
2577 | perf_pmu_enable(pmu); | |
2578 | ||
2579 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2580 | } | |
2581 | } | |
2582 | ||
2583 | rcu_read_unlock(); | |
2584 | ||
2585 | local_irq_restore(flags); | |
2586 | } | |
2587 | ||
45ac1403 AH |
2588 | static void perf_event_switch(struct task_struct *task, |
2589 | struct task_struct *next_prev, bool sched_in); | |
2590 | ||
8dc85d54 PZ |
2591 | #define for_each_task_context_nr(ctxn) \ |
2592 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2593 | ||
2594 | /* | |
2595 | * Called from scheduler to remove the events of the current task, | |
2596 | * with interrupts disabled. | |
2597 | * | |
2598 | * We stop each event and update the event value in event->count. | |
2599 | * | |
2600 | * This does not protect us against NMI, but disable() | |
2601 | * sets the disabled bit in the control field of event _before_ | |
2602 | * accessing the event control register. If a NMI hits, then it will | |
2603 | * not restart the event. | |
2604 | */ | |
ab0cce56 JO |
2605 | void __perf_event_task_sched_out(struct task_struct *task, |
2606 | struct task_struct *next) | |
8dc85d54 PZ |
2607 | { |
2608 | int ctxn; | |
2609 | ||
ba532500 YZ |
2610 | if (__this_cpu_read(perf_sched_cb_usages)) |
2611 | perf_pmu_sched_task(task, next, false); | |
2612 | ||
45ac1403 AH |
2613 | if (atomic_read(&nr_switch_events)) |
2614 | perf_event_switch(task, next, false); | |
2615 | ||
8dc85d54 PZ |
2616 | for_each_task_context_nr(ctxn) |
2617 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2618 | |
2619 | /* | |
2620 | * if cgroup events exist on this CPU, then we need | |
2621 | * to check if we have to switch out PMU state. | |
2622 | * cgroup event are system-wide mode only | |
2623 | */ | |
4a32fea9 | 2624 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2625 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2626 | } |
2627 | ||
3e349507 PZ |
2628 | static void task_ctx_sched_out(struct perf_cpu_context *cpuctx, |
2629 | struct perf_event_context *ctx) | |
a08b159f | 2630 | { |
a63eaf34 PM |
2631 | if (!cpuctx->task_ctx) |
2632 | return; | |
012b84da IM |
2633 | |
2634 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2635 | return; | |
2636 | ||
04dc2dbb | 2637 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2638 | } |
2639 | ||
5b0311e1 FW |
2640 | /* |
2641 | * Called with IRQs disabled | |
2642 | */ | |
2643 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2644 | enum event_type_t event_type) | |
2645 | { | |
2646 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2647 | } |
2648 | ||
235c7fc7 | 2649 | static void |
5b0311e1 | 2650 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2651 | struct perf_cpu_context *cpuctx) |
0793a61d | 2652 | { |
cdd6c482 | 2653 | struct perf_event *event; |
0793a61d | 2654 | |
889ff015 FW |
2655 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2656 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2657 | continue; |
5632ab12 | 2658 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2659 | continue; |
2660 | ||
e5d1367f SE |
2661 | /* may need to reset tstamp_enabled */ |
2662 | if (is_cgroup_event(event)) | |
2663 | perf_cgroup_mark_enabled(event, ctx); | |
2664 | ||
8c9ed8e1 | 2665 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2666 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2667 | |
2668 | /* | |
2669 | * If this pinned group hasn't been scheduled, | |
2670 | * put it in error state. | |
2671 | */ | |
cdd6c482 IM |
2672 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2673 | update_group_times(event); | |
2674 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2675 | } |
3b6f9e5c | 2676 | } |
5b0311e1 FW |
2677 | } |
2678 | ||
2679 | static void | |
2680 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2681 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2682 | { |
2683 | struct perf_event *event; | |
2684 | int can_add_hw = 1; | |
3b6f9e5c | 2685 | |
889ff015 FW |
2686 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2687 | /* Ignore events in OFF or ERROR state */ | |
2688 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2689 | continue; |
04289bb9 IM |
2690 | /* |
2691 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2692 | * of events: |
04289bb9 | 2693 | */ |
5632ab12 | 2694 | if (!event_filter_match(event)) |
0793a61d TG |
2695 | continue; |
2696 | ||
e5d1367f SE |
2697 | /* may need to reset tstamp_enabled */ |
2698 | if (is_cgroup_event(event)) | |
2699 | perf_cgroup_mark_enabled(event, ctx); | |
2700 | ||
9ed6060d | 2701 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2702 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2703 | can_add_hw = 0; |
9ed6060d | 2704 | } |
0793a61d | 2705 | } |
5b0311e1 FW |
2706 | } |
2707 | ||
2708 | static void | |
2709 | ctx_sched_in(struct perf_event_context *ctx, | |
2710 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2711 | enum event_type_t event_type, |
2712 | struct task_struct *task) | |
5b0311e1 | 2713 | { |
db24d33e | 2714 | int is_active = ctx->is_active; |
c994d613 PZ |
2715 | u64 now; |
2716 | ||
2717 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2718 | |
db24d33e | 2719 | ctx->is_active |= event_type; |
63e30d3e PZ |
2720 | if (ctx->task) { |
2721 | if (!is_active) | |
2722 | cpuctx->task_ctx = ctx; | |
2723 | else | |
2724 | WARN_ON_ONCE(cpuctx->task_ctx != ctx); | |
2725 | } | |
2726 | ||
5b0311e1 | 2727 | if (likely(!ctx->nr_events)) |
facc4307 | 2728 | return; |
5b0311e1 | 2729 | |
e5d1367f SE |
2730 | now = perf_clock(); |
2731 | ctx->timestamp = now; | |
3f7cce3c | 2732 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2733 | /* |
2734 | * First go through the list and put on any pinned groups | |
2735 | * in order to give them the best chance of going on. | |
2736 | */ | |
db24d33e | 2737 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2738 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2739 | |
2740 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2741 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2742 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2743 | } |
2744 | ||
329c0e01 | 2745 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2746 | enum event_type_t event_type, |
2747 | struct task_struct *task) | |
329c0e01 FW |
2748 | { |
2749 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2750 | ||
e5d1367f | 2751 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2752 | } |
2753 | ||
e5d1367f SE |
2754 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2755 | struct task_struct *task) | |
235c7fc7 | 2756 | { |
108b02cf | 2757 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2758 | |
108b02cf | 2759 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2760 | if (cpuctx->task_ctx == ctx) |
2761 | return; | |
2762 | ||
facc4307 | 2763 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2764 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2765 | /* |
2766 | * We want to keep the following priority order: | |
2767 | * cpu pinned (that don't need to move), task pinned, | |
2768 | * cpu flexible, task flexible. | |
2769 | */ | |
2770 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
63e30d3e | 2771 | perf_event_sched_in(cpuctx, ctx, task); |
facc4307 PZ |
2772 | perf_pmu_enable(ctx->pmu); |
2773 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2774 | } |
2775 | ||
8dc85d54 PZ |
2776 | /* |
2777 | * Called from scheduler to add the events of the current task | |
2778 | * with interrupts disabled. | |
2779 | * | |
2780 | * We restore the event value and then enable it. | |
2781 | * | |
2782 | * This does not protect us against NMI, but enable() | |
2783 | * sets the enabled bit in the control field of event _before_ | |
2784 | * accessing the event control register. If a NMI hits, then it will | |
2785 | * keep the event running. | |
2786 | */ | |
ab0cce56 JO |
2787 | void __perf_event_task_sched_in(struct task_struct *prev, |
2788 | struct task_struct *task) | |
8dc85d54 PZ |
2789 | { |
2790 | struct perf_event_context *ctx; | |
2791 | int ctxn; | |
2792 | ||
7e41d177 PZ |
2793 | /* |
2794 | * If cgroup events exist on this CPU, then we need to check if we have | |
2795 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2796 | * | |
2797 | * Since cgroup events are CPU events, we must schedule these in before | |
2798 | * we schedule in the task events. | |
2799 | */ | |
2800 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2801 | perf_cgroup_sched_in(prev, task); | |
2802 | ||
8dc85d54 PZ |
2803 | for_each_task_context_nr(ctxn) { |
2804 | ctx = task->perf_event_ctxp[ctxn]; | |
2805 | if (likely(!ctx)) | |
2806 | continue; | |
2807 | ||
e5d1367f | 2808 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2809 | } |
d010b332 | 2810 | |
45ac1403 AH |
2811 | if (atomic_read(&nr_switch_events)) |
2812 | perf_event_switch(task, prev, true); | |
2813 | ||
ba532500 YZ |
2814 | if (__this_cpu_read(perf_sched_cb_usages)) |
2815 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2816 | } |
2817 | ||
abd50713 PZ |
2818 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2819 | { | |
2820 | u64 frequency = event->attr.sample_freq; | |
2821 | u64 sec = NSEC_PER_SEC; | |
2822 | u64 divisor, dividend; | |
2823 | ||
2824 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2825 | ||
2826 | count_fls = fls64(count); | |
2827 | nsec_fls = fls64(nsec); | |
2828 | frequency_fls = fls64(frequency); | |
2829 | sec_fls = 30; | |
2830 | ||
2831 | /* | |
2832 | * We got @count in @nsec, with a target of sample_freq HZ | |
2833 | * the target period becomes: | |
2834 | * | |
2835 | * @count * 10^9 | |
2836 | * period = ------------------- | |
2837 | * @nsec * sample_freq | |
2838 | * | |
2839 | */ | |
2840 | ||
2841 | /* | |
2842 | * Reduce accuracy by one bit such that @a and @b converge | |
2843 | * to a similar magnitude. | |
2844 | */ | |
fe4b04fa | 2845 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2846 | do { \ |
2847 | if (a##_fls > b##_fls) { \ | |
2848 | a >>= 1; \ | |
2849 | a##_fls--; \ | |
2850 | } else { \ | |
2851 | b >>= 1; \ | |
2852 | b##_fls--; \ | |
2853 | } \ | |
2854 | } while (0) | |
2855 | ||
2856 | /* | |
2857 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2858 | * the other, so that finally we can do a u64/u64 division. | |
2859 | */ | |
2860 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2861 | REDUCE_FLS(nsec, frequency); | |
2862 | REDUCE_FLS(sec, count); | |
2863 | } | |
2864 | ||
2865 | if (count_fls + sec_fls > 64) { | |
2866 | divisor = nsec * frequency; | |
2867 | ||
2868 | while (count_fls + sec_fls > 64) { | |
2869 | REDUCE_FLS(count, sec); | |
2870 | divisor >>= 1; | |
2871 | } | |
2872 | ||
2873 | dividend = count * sec; | |
2874 | } else { | |
2875 | dividend = count * sec; | |
2876 | ||
2877 | while (nsec_fls + frequency_fls > 64) { | |
2878 | REDUCE_FLS(nsec, frequency); | |
2879 | dividend >>= 1; | |
2880 | } | |
2881 | ||
2882 | divisor = nsec * frequency; | |
2883 | } | |
2884 | ||
f6ab91ad PZ |
2885 | if (!divisor) |
2886 | return dividend; | |
2887 | ||
abd50713 PZ |
2888 | return div64_u64(dividend, divisor); |
2889 | } | |
2890 | ||
e050e3f0 SE |
2891 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2892 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2893 | ||
f39d47ff | 2894 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2895 | { |
cdd6c482 | 2896 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2897 | s64 period, sample_period; |
bd2b5b12 PZ |
2898 | s64 delta; |
2899 | ||
abd50713 | 2900 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2901 | |
2902 | delta = (s64)(period - hwc->sample_period); | |
2903 | delta = (delta + 7) / 8; /* low pass filter */ | |
2904 | ||
2905 | sample_period = hwc->sample_period + delta; | |
2906 | ||
2907 | if (!sample_period) | |
2908 | sample_period = 1; | |
2909 | ||
bd2b5b12 | 2910 | hwc->sample_period = sample_period; |
abd50713 | 2911 | |
e7850595 | 2912 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2913 | if (disable) |
2914 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2915 | ||
e7850595 | 2916 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2917 | |
2918 | if (disable) | |
2919 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2920 | } |
bd2b5b12 PZ |
2921 | } |
2922 | ||
e050e3f0 SE |
2923 | /* |
2924 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2925 | * events. At the same time, make sure, having freq events does not change | |
2926 | * the rate of unthrottling as that would introduce bias. | |
2927 | */ | |
2928 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2929 | int needs_unthr) | |
60db5e09 | 2930 | { |
cdd6c482 IM |
2931 | struct perf_event *event; |
2932 | struct hw_perf_event *hwc; | |
e050e3f0 | 2933 | u64 now, period = TICK_NSEC; |
abd50713 | 2934 | s64 delta; |
60db5e09 | 2935 | |
e050e3f0 SE |
2936 | /* |
2937 | * only need to iterate over all events iff: | |
2938 | * - context have events in frequency mode (needs freq adjust) | |
2939 | * - there are events to unthrottle on this cpu | |
2940 | */ | |
2941 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2942 | return; |
2943 | ||
e050e3f0 | 2944 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2945 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2946 | |
03541f8b | 2947 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2948 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2949 | continue; |
2950 | ||
5632ab12 | 2951 | if (!event_filter_match(event)) |
5d27c23d PZ |
2952 | continue; |
2953 | ||
44377277 AS |
2954 | perf_pmu_disable(event->pmu); |
2955 | ||
cdd6c482 | 2956 | hwc = &event->hw; |
6a24ed6c | 2957 | |
ae23bff1 | 2958 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2959 | hwc->interrupts = 0; |
cdd6c482 | 2960 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2961 | event->pmu->start(event, 0); |
a78ac325 PZ |
2962 | } |
2963 | ||
cdd6c482 | 2964 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2965 | goto next; |
60db5e09 | 2966 | |
e050e3f0 SE |
2967 | /* |
2968 | * stop the event and update event->count | |
2969 | */ | |
2970 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2971 | ||
e7850595 | 2972 | now = local64_read(&event->count); |
abd50713 PZ |
2973 | delta = now - hwc->freq_count_stamp; |
2974 | hwc->freq_count_stamp = now; | |
60db5e09 | 2975 | |
e050e3f0 SE |
2976 | /* |
2977 | * restart the event | |
2978 | * reload only if value has changed | |
f39d47ff SE |
2979 | * we have stopped the event so tell that |
2980 | * to perf_adjust_period() to avoid stopping it | |
2981 | * twice. | |
e050e3f0 | 2982 | */ |
abd50713 | 2983 | if (delta > 0) |
f39d47ff | 2984 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
2985 | |
2986 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
2987 | next: |
2988 | perf_pmu_enable(event->pmu); | |
60db5e09 | 2989 | } |
e050e3f0 | 2990 | |
f39d47ff | 2991 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 2992 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
2993 | } |
2994 | ||
235c7fc7 | 2995 | /* |
cdd6c482 | 2996 | * Round-robin a context's events: |
235c7fc7 | 2997 | */ |
cdd6c482 | 2998 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 2999 | { |
dddd3379 TG |
3000 | /* |
3001 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3002 | * disabled by the inheritance code. | |
3003 | */ | |
3004 | if (!ctx->rotate_disable) | |
3005 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3006 | } |
3007 | ||
9e630205 | 3008 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3009 | { |
8dc85d54 | 3010 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3011 | int rotate = 0; |
7fc23a53 | 3012 | |
b5ab4cd5 | 3013 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3014 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3015 | rotate = 1; | |
3016 | } | |
235c7fc7 | 3017 | |
8dc85d54 | 3018 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3019 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3020 | if (ctx->nr_events != ctx->nr_active) |
3021 | rotate = 1; | |
3022 | } | |
9717e6cd | 3023 | |
e050e3f0 | 3024 | if (!rotate) |
0f5a2601 PZ |
3025 | goto done; |
3026 | ||
facc4307 | 3027 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3028 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3029 | |
e050e3f0 SE |
3030 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3031 | if (ctx) | |
3032 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3033 | |
e050e3f0 SE |
3034 | rotate_ctx(&cpuctx->ctx); |
3035 | if (ctx) | |
3036 | rotate_ctx(ctx); | |
235c7fc7 | 3037 | |
e050e3f0 | 3038 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3039 | |
0f5a2601 PZ |
3040 | perf_pmu_enable(cpuctx->ctx.pmu); |
3041 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3042 | done: |
9e630205 SE |
3043 | |
3044 | return rotate; | |
e9d2b064 PZ |
3045 | } |
3046 | ||
026249ef FW |
3047 | #ifdef CONFIG_NO_HZ_FULL |
3048 | bool perf_event_can_stop_tick(void) | |
3049 | { | |
948b26b6 | 3050 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3051 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3052 | return false; |
d84153d6 FW |
3053 | else |
3054 | return true; | |
026249ef FW |
3055 | } |
3056 | #endif | |
3057 | ||
e9d2b064 PZ |
3058 | void perf_event_task_tick(void) |
3059 | { | |
2fde4f94 MR |
3060 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3061 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3062 | int throttled; |
b5ab4cd5 | 3063 | |
e9d2b064 PZ |
3064 | WARN_ON(!irqs_disabled()); |
3065 | ||
e050e3f0 SE |
3066 | __this_cpu_inc(perf_throttled_seq); |
3067 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3068 | ||
2fde4f94 | 3069 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3070 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3071 | } |
3072 | ||
889ff015 FW |
3073 | static int event_enable_on_exec(struct perf_event *event, |
3074 | struct perf_event_context *ctx) | |
3075 | { | |
3076 | if (!event->attr.enable_on_exec) | |
3077 | return 0; | |
3078 | ||
3079 | event->attr.enable_on_exec = 0; | |
3080 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3081 | return 0; | |
3082 | ||
1d9b482e | 3083 | __perf_event_mark_enabled(event); |
889ff015 FW |
3084 | |
3085 | return 1; | |
3086 | } | |
3087 | ||
57e7986e | 3088 | /* |
cdd6c482 | 3089 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3090 | * This expects task == current. |
3091 | */ | |
c1274499 | 3092 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3093 | { |
c1274499 | 3094 | struct perf_event_context *ctx, *clone_ctx = NULL; |
3e349507 | 3095 | struct perf_cpu_context *cpuctx; |
cdd6c482 | 3096 | struct perf_event *event; |
57e7986e PM |
3097 | unsigned long flags; |
3098 | int enabled = 0; | |
3099 | ||
3100 | local_irq_save(flags); | |
c1274499 | 3101 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3102 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3103 | goto out; |
3104 | ||
3e349507 PZ |
3105 | cpuctx = __get_cpu_context(ctx); |
3106 | perf_ctx_lock(cpuctx, ctx); | |
3107 | list_for_each_entry(event, &ctx->event_list, event_entry) | |
3108 | enabled |= event_enable_on_exec(event, ctx); | |
57e7986e PM |
3109 | |
3110 | /* | |
3e349507 | 3111 | * Unclone and reschedule this context if we enabled any event. |
57e7986e | 3112 | */ |
3e349507 | 3113 | if (enabled) { |
211de6eb | 3114 | clone_ctx = unclone_ctx(ctx); |
3e349507 PZ |
3115 | ctx_resched(cpuctx, ctx); |
3116 | } | |
3117 | perf_ctx_unlock(cpuctx, ctx); | |
57e7986e | 3118 | |
9ed6060d | 3119 | out: |
57e7986e | 3120 | local_irq_restore(flags); |
211de6eb PZ |
3121 | |
3122 | if (clone_ctx) | |
3123 | put_ctx(clone_ctx); | |
57e7986e PM |
3124 | } |
3125 | ||
e041e328 PZ |
3126 | void perf_event_exec(void) |
3127 | { | |
e041e328 PZ |
3128 | int ctxn; |
3129 | ||
3130 | rcu_read_lock(); | |
c1274499 PZ |
3131 | for_each_task_context_nr(ctxn) |
3132 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3133 | rcu_read_unlock(); |
3134 | } | |
3135 | ||
0492d4c5 PZ |
3136 | struct perf_read_data { |
3137 | struct perf_event *event; | |
3138 | bool group; | |
7d88962e | 3139 | int ret; |
0492d4c5 PZ |
3140 | }; |
3141 | ||
0793a61d | 3142 | /* |
cdd6c482 | 3143 | * Cross CPU call to read the hardware event |
0793a61d | 3144 | */ |
cdd6c482 | 3145 | static void __perf_event_read(void *info) |
0793a61d | 3146 | { |
0492d4c5 PZ |
3147 | struct perf_read_data *data = info; |
3148 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3149 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3150 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3151 | struct pmu *pmu = event->pmu; |
621a01ea | 3152 | |
e1ac3614 PM |
3153 | /* |
3154 | * If this is a task context, we need to check whether it is | |
3155 | * the current task context of this cpu. If not it has been | |
3156 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3157 | * event->count would have been updated to a recent sample |
3158 | * when the event was scheduled out. | |
e1ac3614 PM |
3159 | */ |
3160 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3161 | return; | |
3162 | ||
e625cce1 | 3163 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3164 | if (ctx->is_active) { |
542e72fc | 3165 | update_context_time(ctx); |
e5d1367f SE |
3166 | update_cgrp_time_from_event(event); |
3167 | } | |
0492d4c5 | 3168 | |
cdd6c482 | 3169 | update_event_times(event); |
4a00c16e SB |
3170 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3171 | goto unlock; | |
0492d4c5 | 3172 | |
4a00c16e SB |
3173 | if (!data->group) { |
3174 | pmu->read(event); | |
3175 | data->ret = 0; | |
0492d4c5 | 3176 | goto unlock; |
4a00c16e SB |
3177 | } |
3178 | ||
3179 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3180 | ||
3181 | pmu->read(event); | |
0492d4c5 PZ |
3182 | |
3183 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3184 | update_event_times(sub); | |
4a00c16e SB |
3185 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3186 | /* | |
3187 | * Use sibling's PMU rather than @event's since | |
3188 | * sibling could be on different (eg: software) PMU. | |
3189 | */ | |
0492d4c5 | 3190 | sub->pmu->read(sub); |
4a00c16e | 3191 | } |
0492d4c5 | 3192 | } |
4a00c16e SB |
3193 | |
3194 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3195 | |
3196 | unlock: | |
e625cce1 | 3197 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3198 | } |
3199 | ||
b5e58793 PZ |
3200 | static inline u64 perf_event_count(struct perf_event *event) |
3201 | { | |
eacd3ecc MF |
3202 | if (event->pmu->count) |
3203 | return event->pmu->count(event); | |
3204 | ||
3205 | return __perf_event_count(event); | |
b5e58793 PZ |
3206 | } |
3207 | ||
ffe8690c KX |
3208 | /* |
3209 | * NMI-safe method to read a local event, that is an event that | |
3210 | * is: | |
3211 | * - either for the current task, or for this CPU | |
3212 | * - does not have inherit set, for inherited task events | |
3213 | * will not be local and we cannot read them atomically | |
3214 | * - must not have a pmu::count method | |
3215 | */ | |
3216 | u64 perf_event_read_local(struct perf_event *event) | |
3217 | { | |
3218 | unsigned long flags; | |
3219 | u64 val; | |
3220 | ||
3221 | /* | |
3222 | * Disabling interrupts avoids all counter scheduling (context | |
3223 | * switches, timer based rotation and IPIs). | |
3224 | */ | |
3225 | local_irq_save(flags); | |
3226 | ||
3227 | /* If this is a per-task event, it must be for current */ | |
3228 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3229 | event->hw.target != current); | |
3230 | ||
3231 | /* If this is a per-CPU event, it must be for this CPU */ | |
3232 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3233 | event->cpu != smp_processor_id()); | |
3234 | ||
3235 | /* | |
3236 | * It must not be an event with inherit set, we cannot read | |
3237 | * all child counters from atomic context. | |
3238 | */ | |
3239 | WARN_ON_ONCE(event->attr.inherit); | |
3240 | ||
3241 | /* | |
3242 | * It must not have a pmu::count method, those are not | |
3243 | * NMI safe. | |
3244 | */ | |
3245 | WARN_ON_ONCE(event->pmu->count); | |
3246 | ||
3247 | /* | |
3248 | * If the event is currently on this CPU, its either a per-task event, | |
3249 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3250 | * oncpu == -1). | |
3251 | */ | |
3252 | if (event->oncpu == smp_processor_id()) | |
3253 | event->pmu->read(event); | |
3254 | ||
3255 | val = local64_read(&event->count); | |
3256 | local_irq_restore(flags); | |
3257 | ||
3258 | return val; | |
3259 | } | |
3260 | ||
7d88962e | 3261 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3262 | { |
7d88962e SB |
3263 | int ret = 0; |
3264 | ||
0793a61d | 3265 | /* |
cdd6c482 IM |
3266 | * If event is enabled and currently active on a CPU, update the |
3267 | * value in the event structure: | |
0793a61d | 3268 | */ |
cdd6c482 | 3269 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3270 | struct perf_read_data data = { |
3271 | .event = event, | |
3272 | .group = group, | |
7d88962e | 3273 | .ret = 0, |
0492d4c5 | 3274 | }; |
cdd6c482 | 3275 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3276 | __perf_event_read, &data, 1); |
7d88962e | 3277 | ret = data.ret; |
cdd6c482 | 3278 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3279 | struct perf_event_context *ctx = event->ctx; |
3280 | unsigned long flags; | |
3281 | ||
e625cce1 | 3282 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3283 | /* |
3284 | * may read while context is not active | |
3285 | * (e.g., thread is blocked), in that case | |
3286 | * we cannot update context time | |
3287 | */ | |
e5d1367f | 3288 | if (ctx->is_active) { |
c530ccd9 | 3289 | update_context_time(ctx); |
e5d1367f SE |
3290 | update_cgrp_time_from_event(event); |
3291 | } | |
0492d4c5 PZ |
3292 | if (group) |
3293 | update_group_times(event); | |
3294 | else | |
3295 | update_event_times(event); | |
e625cce1 | 3296 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3297 | } |
7d88962e SB |
3298 | |
3299 | return ret; | |
0793a61d TG |
3300 | } |
3301 | ||
a63eaf34 | 3302 | /* |
cdd6c482 | 3303 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3304 | */ |
eb184479 | 3305 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3306 | { |
e625cce1 | 3307 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3308 | mutex_init(&ctx->mutex); |
2fde4f94 | 3309 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3310 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3311 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3312 | INIT_LIST_HEAD(&ctx->event_list); |
3313 | atomic_set(&ctx->refcount, 1); | |
fadfe7be | 3314 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); |
eb184479 PZ |
3315 | } |
3316 | ||
3317 | static struct perf_event_context * | |
3318 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3319 | { | |
3320 | struct perf_event_context *ctx; | |
3321 | ||
3322 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3323 | if (!ctx) | |
3324 | return NULL; | |
3325 | ||
3326 | __perf_event_init_context(ctx); | |
3327 | if (task) { | |
3328 | ctx->task = task; | |
3329 | get_task_struct(task); | |
0793a61d | 3330 | } |
eb184479 PZ |
3331 | ctx->pmu = pmu; |
3332 | ||
3333 | return ctx; | |
a63eaf34 PM |
3334 | } |
3335 | ||
2ebd4ffb MH |
3336 | static struct task_struct * |
3337 | find_lively_task_by_vpid(pid_t vpid) | |
3338 | { | |
3339 | struct task_struct *task; | |
3340 | int err; | |
0793a61d TG |
3341 | |
3342 | rcu_read_lock(); | |
2ebd4ffb | 3343 | if (!vpid) |
0793a61d TG |
3344 | task = current; |
3345 | else | |
2ebd4ffb | 3346 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3347 | if (task) |
3348 | get_task_struct(task); | |
3349 | rcu_read_unlock(); | |
3350 | ||
3351 | if (!task) | |
3352 | return ERR_PTR(-ESRCH); | |
3353 | ||
0793a61d | 3354 | /* Reuse ptrace permission checks for now. */ |
c93f7669 PM |
3355 | err = -EACCES; |
3356 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3357 | goto errout; | |
3358 | ||
2ebd4ffb MH |
3359 | return task; |
3360 | errout: | |
3361 | put_task_struct(task); | |
3362 | return ERR_PTR(err); | |
3363 | ||
3364 | } | |
3365 | ||
fe4b04fa PZ |
3366 | /* |
3367 | * Returns a matching context with refcount and pincount. | |
3368 | */ | |
108b02cf | 3369 | static struct perf_event_context * |
4af57ef2 YZ |
3370 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3371 | struct perf_event *event) | |
0793a61d | 3372 | { |
211de6eb | 3373 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3374 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3375 | void *task_ctx_data = NULL; |
25346b93 | 3376 | unsigned long flags; |
8dc85d54 | 3377 | int ctxn, err; |
4af57ef2 | 3378 | int cpu = event->cpu; |
0793a61d | 3379 | |
22a4ec72 | 3380 | if (!task) { |
cdd6c482 | 3381 | /* Must be root to operate on a CPU event: */ |
0764771d | 3382 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3383 | return ERR_PTR(-EACCES); |
3384 | ||
0793a61d | 3385 | /* |
cdd6c482 | 3386 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3387 | * offline CPU and activate it when the CPU comes up, but |
3388 | * that's for later. | |
3389 | */ | |
f6325e30 | 3390 | if (!cpu_online(cpu)) |
0793a61d TG |
3391 | return ERR_PTR(-ENODEV); |
3392 | ||
108b02cf | 3393 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3394 | ctx = &cpuctx->ctx; |
c93f7669 | 3395 | get_ctx(ctx); |
fe4b04fa | 3396 | ++ctx->pin_count; |
0793a61d | 3397 | |
0793a61d TG |
3398 | return ctx; |
3399 | } | |
3400 | ||
8dc85d54 PZ |
3401 | err = -EINVAL; |
3402 | ctxn = pmu->task_ctx_nr; | |
3403 | if (ctxn < 0) | |
3404 | goto errout; | |
3405 | ||
4af57ef2 YZ |
3406 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3407 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3408 | if (!task_ctx_data) { | |
3409 | err = -ENOMEM; | |
3410 | goto errout; | |
3411 | } | |
3412 | } | |
3413 | ||
9ed6060d | 3414 | retry: |
8dc85d54 | 3415 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3416 | if (ctx) { |
211de6eb | 3417 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3418 | ++ctx->pin_count; |
4af57ef2 YZ |
3419 | |
3420 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3421 | ctx->task_ctx_data = task_ctx_data; | |
3422 | task_ctx_data = NULL; | |
3423 | } | |
e625cce1 | 3424 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3425 | |
3426 | if (clone_ctx) | |
3427 | put_ctx(clone_ctx); | |
9137fb28 | 3428 | } else { |
eb184479 | 3429 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3430 | err = -ENOMEM; |
3431 | if (!ctx) | |
3432 | goto errout; | |
eb184479 | 3433 | |
4af57ef2 YZ |
3434 | if (task_ctx_data) { |
3435 | ctx->task_ctx_data = task_ctx_data; | |
3436 | task_ctx_data = NULL; | |
3437 | } | |
3438 | ||
dbe08d82 ON |
3439 | err = 0; |
3440 | mutex_lock(&task->perf_event_mutex); | |
3441 | /* | |
3442 | * If it has already passed perf_event_exit_task(). | |
3443 | * we must see PF_EXITING, it takes this mutex too. | |
3444 | */ | |
3445 | if (task->flags & PF_EXITING) | |
3446 | err = -ESRCH; | |
3447 | else if (task->perf_event_ctxp[ctxn]) | |
3448 | err = -EAGAIN; | |
fe4b04fa | 3449 | else { |
9137fb28 | 3450 | get_ctx(ctx); |
fe4b04fa | 3451 | ++ctx->pin_count; |
dbe08d82 | 3452 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3453 | } |
dbe08d82 ON |
3454 | mutex_unlock(&task->perf_event_mutex); |
3455 | ||
3456 | if (unlikely(err)) { | |
9137fb28 | 3457 | put_ctx(ctx); |
dbe08d82 ON |
3458 | |
3459 | if (err == -EAGAIN) | |
3460 | goto retry; | |
3461 | goto errout; | |
a63eaf34 PM |
3462 | } |
3463 | } | |
3464 | ||
4af57ef2 | 3465 | kfree(task_ctx_data); |
0793a61d | 3466 | return ctx; |
c93f7669 | 3467 | |
9ed6060d | 3468 | errout: |
4af57ef2 | 3469 | kfree(task_ctx_data); |
c93f7669 | 3470 | return ERR_PTR(err); |
0793a61d TG |
3471 | } |
3472 | ||
6fb2915d | 3473 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3474 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3475 | |
cdd6c482 | 3476 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3477 | { |
cdd6c482 | 3478 | struct perf_event *event; |
592903cd | 3479 | |
cdd6c482 IM |
3480 | event = container_of(head, struct perf_event, rcu_head); |
3481 | if (event->ns) | |
3482 | put_pid_ns(event->ns); | |
6fb2915d | 3483 | perf_event_free_filter(event); |
cdd6c482 | 3484 | kfree(event); |
592903cd PZ |
3485 | } |
3486 | ||
b69cf536 PZ |
3487 | static void ring_buffer_attach(struct perf_event *event, |
3488 | struct ring_buffer *rb); | |
925d519a | 3489 | |
4beb31f3 | 3490 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3491 | { |
4beb31f3 FW |
3492 | if (event->parent) |
3493 | return; | |
3494 | ||
4beb31f3 FW |
3495 | if (is_cgroup_event(event)) |
3496 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3497 | } | |
925d519a | 3498 | |
4beb31f3 FW |
3499 | static void unaccount_event(struct perf_event *event) |
3500 | { | |
25432ae9 PZ |
3501 | bool dec = false; |
3502 | ||
4beb31f3 FW |
3503 | if (event->parent) |
3504 | return; | |
3505 | ||
3506 | if (event->attach_state & PERF_ATTACH_TASK) | |
25432ae9 | 3507 | dec = true; |
4beb31f3 FW |
3508 | if (event->attr.mmap || event->attr.mmap_data) |
3509 | atomic_dec(&nr_mmap_events); | |
3510 | if (event->attr.comm) | |
3511 | atomic_dec(&nr_comm_events); | |
3512 | if (event->attr.task) | |
3513 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3514 | if (event->attr.freq) |
3515 | atomic_dec(&nr_freq_events); | |
45ac1403 | 3516 | if (event->attr.context_switch) { |
25432ae9 | 3517 | dec = true; |
45ac1403 AH |
3518 | atomic_dec(&nr_switch_events); |
3519 | } | |
4beb31f3 | 3520 | if (is_cgroup_event(event)) |
25432ae9 | 3521 | dec = true; |
4beb31f3 | 3522 | if (has_branch_stack(event)) |
25432ae9 PZ |
3523 | dec = true; |
3524 | ||
3525 | if (dec) | |
4beb31f3 FW |
3526 | static_key_slow_dec_deferred(&perf_sched_events); |
3527 | ||
3528 | unaccount_event_cpu(event, event->cpu); | |
3529 | } | |
925d519a | 3530 | |
bed5b25a AS |
3531 | /* |
3532 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3533 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3534 | * at a time, so we disallow creating events that might conflict, namely: | |
3535 | * | |
3536 | * 1) cpu-wide events in the presence of per-task events, | |
3537 | * 2) per-task events in the presence of cpu-wide events, | |
3538 | * 3) two matching events on the same context. | |
3539 | * | |
3540 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
3541 | * __free_event()), the latter -- before the first perf_install_in_context(). | |
3542 | */ | |
3543 | static int exclusive_event_init(struct perf_event *event) | |
3544 | { | |
3545 | struct pmu *pmu = event->pmu; | |
3546 | ||
3547 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3548 | return 0; | |
3549 | ||
3550 | /* | |
3551 | * Prevent co-existence of per-task and cpu-wide events on the | |
3552 | * same exclusive pmu. | |
3553 | * | |
3554 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3555 | * events on this "exclusive" pmu, positive means there are | |
3556 | * per-task events. | |
3557 | * | |
3558 | * Since this is called in perf_event_alloc() path, event::ctx | |
3559 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3560 | * to mean "per-task event", because unlike other attach states it | |
3561 | * never gets cleared. | |
3562 | */ | |
3563 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3564 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3565 | return -EBUSY; | |
3566 | } else { | |
3567 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3568 | return -EBUSY; | |
3569 | } | |
3570 | ||
3571 | return 0; | |
3572 | } | |
3573 | ||
3574 | static void exclusive_event_destroy(struct perf_event *event) | |
3575 | { | |
3576 | struct pmu *pmu = event->pmu; | |
3577 | ||
3578 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3579 | return; | |
3580 | ||
3581 | /* see comment in exclusive_event_init() */ | |
3582 | if (event->attach_state & PERF_ATTACH_TASK) | |
3583 | atomic_dec(&pmu->exclusive_cnt); | |
3584 | else | |
3585 | atomic_inc(&pmu->exclusive_cnt); | |
3586 | } | |
3587 | ||
3588 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3589 | { | |
3590 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3591 | (e1->cpu == e2->cpu || | |
3592 | e1->cpu == -1 || | |
3593 | e2->cpu == -1)) | |
3594 | return true; | |
3595 | return false; | |
3596 | } | |
3597 | ||
3598 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3599 | static bool exclusive_event_installable(struct perf_event *event, | |
3600 | struct perf_event_context *ctx) | |
3601 | { | |
3602 | struct perf_event *iter_event; | |
3603 | struct pmu *pmu = event->pmu; | |
3604 | ||
3605 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3606 | return true; | |
3607 | ||
3608 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3609 | if (exclusive_event_match(iter_event, event)) | |
3610 | return false; | |
3611 | } | |
3612 | ||
3613 | return true; | |
3614 | } | |
3615 | ||
766d6c07 FW |
3616 | static void __free_event(struct perf_event *event) |
3617 | { | |
cdd6c482 | 3618 | if (!event->parent) { |
927c7a9e FW |
3619 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3620 | put_callchain_buffers(); | |
f344011c | 3621 | } |
9ee318a7 | 3622 | |
dead9f29 AS |
3623 | perf_event_free_bpf_prog(event); |
3624 | ||
766d6c07 FW |
3625 | if (event->destroy) |
3626 | event->destroy(event); | |
3627 | ||
3628 | if (event->ctx) | |
3629 | put_ctx(event->ctx); | |
3630 | ||
bed5b25a AS |
3631 | if (event->pmu) { |
3632 | exclusive_event_destroy(event); | |
c464c76e | 3633 | module_put(event->pmu->module); |
bed5b25a | 3634 | } |
c464c76e | 3635 | |
766d6c07 FW |
3636 | call_rcu(&event->rcu_head, free_event_rcu); |
3637 | } | |
683ede43 PZ |
3638 | |
3639 | static void _free_event(struct perf_event *event) | |
f1600952 | 3640 | { |
e360adbe | 3641 | irq_work_sync(&event->pending); |
925d519a | 3642 | |
4beb31f3 | 3643 | unaccount_event(event); |
9ee318a7 | 3644 | |
76369139 | 3645 | if (event->rb) { |
9bb5d40c PZ |
3646 | /* |
3647 | * Can happen when we close an event with re-directed output. | |
3648 | * | |
3649 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3650 | * over us; possibly making our ring_buffer_put() the last. | |
3651 | */ | |
3652 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3653 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3654 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3655 | } |
3656 | ||
e5d1367f SE |
3657 | if (is_cgroup_event(event)) |
3658 | perf_detach_cgroup(event); | |
3659 | ||
766d6c07 | 3660 | __free_event(event); |
f1600952 PZ |
3661 | } |
3662 | ||
683ede43 PZ |
3663 | /* |
3664 | * Used to free events which have a known refcount of 1, such as in error paths | |
3665 | * where the event isn't exposed yet and inherited events. | |
3666 | */ | |
3667 | static void free_event(struct perf_event *event) | |
0793a61d | 3668 | { |
683ede43 PZ |
3669 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3670 | "unexpected event refcount: %ld; ptr=%p\n", | |
3671 | atomic_long_read(&event->refcount), event)) { | |
3672 | /* leak to avoid use-after-free */ | |
3673 | return; | |
3674 | } | |
0793a61d | 3675 | |
683ede43 | 3676 | _free_event(event); |
0793a61d TG |
3677 | } |
3678 | ||
a66a3052 | 3679 | /* |
f8697762 | 3680 | * Remove user event from the owner task. |
a66a3052 | 3681 | */ |
f8697762 | 3682 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3683 | { |
8882135b | 3684 | struct task_struct *owner; |
fb0459d7 | 3685 | |
8882135b PZ |
3686 | rcu_read_lock(); |
3687 | owner = ACCESS_ONCE(event->owner); | |
3688 | /* | |
3689 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3690 | * !owner it means the list deletion is complete and we can indeed | |
3691 | * free this event, otherwise we need to serialize on | |
3692 | * owner->perf_event_mutex. | |
3693 | */ | |
3694 | smp_read_barrier_depends(); | |
3695 | if (owner) { | |
3696 | /* | |
3697 | * Since delayed_put_task_struct() also drops the last | |
3698 | * task reference we can safely take a new reference | |
3699 | * while holding the rcu_read_lock(). | |
3700 | */ | |
3701 | get_task_struct(owner); | |
3702 | } | |
3703 | rcu_read_unlock(); | |
3704 | ||
3705 | if (owner) { | |
f63a8daa PZ |
3706 | /* |
3707 | * If we're here through perf_event_exit_task() we're already | |
3708 | * holding ctx->mutex which would be an inversion wrt. the | |
3709 | * normal lock order. | |
3710 | * | |
3711 | * However we can safely take this lock because its the child | |
3712 | * ctx->mutex. | |
3713 | */ | |
3714 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3715 | ||
8882135b PZ |
3716 | /* |
3717 | * We have to re-check the event->owner field, if it is cleared | |
3718 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3719 | * ensured they're done, and we can proceed with freeing the | |
3720 | * event. | |
3721 | */ | |
3722 | if (event->owner) | |
3723 | list_del_init(&event->owner_entry); | |
3724 | mutex_unlock(&owner->perf_event_mutex); | |
3725 | put_task_struct(owner); | |
3726 | } | |
f8697762 JO |
3727 | } |
3728 | ||
f8697762 JO |
3729 | static void put_event(struct perf_event *event) |
3730 | { | |
a83fe28e | 3731 | struct perf_event_context *ctx; |
f8697762 JO |
3732 | |
3733 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3734 | return; | |
3735 | ||
3736 | if (!is_kernel_event(event)) | |
3737 | perf_remove_from_owner(event); | |
8882135b | 3738 | |
683ede43 PZ |
3739 | /* |
3740 | * There are two ways this annotation is useful: | |
3741 | * | |
3742 | * 1) there is a lock recursion from perf_event_exit_task | |
3743 | * see the comment there. | |
3744 | * | |
3745 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3746 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3747 | * holding ctx->mutex, however this is called after |
3748 | * the last filedesc died, so there is no possibility | |
3749 | * to trigger the AB-BA case. | |
3750 | */ | |
a83fe28e PZ |
3751 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3752 | WARN_ON_ONCE(ctx->parent_ctx); | |
683ede43 | 3753 | perf_remove_from_context(event, true); |
d415a7f1 | 3754 | perf_event_ctx_unlock(event, ctx); |
683ede43 PZ |
3755 | |
3756 | _free_event(event); | |
a6fa941d AV |
3757 | } |
3758 | ||
683ede43 PZ |
3759 | int perf_event_release_kernel(struct perf_event *event) |
3760 | { | |
3761 | put_event(event); | |
3762 | return 0; | |
3763 | } | |
3764 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3765 | ||
8b10c5e2 PZ |
3766 | /* |
3767 | * Called when the last reference to the file is gone. | |
3768 | */ | |
a6fa941d AV |
3769 | static int perf_release(struct inode *inode, struct file *file) |
3770 | { | |
3771 | put_event(file->private_data); | |
3772 | return 0; | |
fb0459d7 | 3773 | } |
fb0459d7 | 3774 | |
fadfe7be JO |
3775 | /* |
3776 | * Remove all orphanes events from the context. | |
3777 | */ | |
3778 | static void orphans_remove_work(struct work_struct *work) | |
3779 | { | |
3780 | struct perf_event_context *ctx; | |
3781 | struct perf_event *event, *tmp; | |
3782 | ||
3783 | ctx = container_of(work, struct perf_event_context, | |
3784 | orphans_remove.work); | |
3785 | ||
3786 | mutex_lock(&ctx->mutex); | |
3787 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3788 | struct perf_event *parent_event = event->parent; | |
3789 | ||
3790 | if (!is_orphaned_child(event)) | |
3791 | continue; | |
3792 | ||
3793 | perf_remove_from_context(event, true); | |
3794 | ||
3795 | mutex_lock(&parent_event->child_mutex); | |
3796 | list_del_init(&event->child_list); | |
3797 | mutex_unlock(&parent_event->child_mutex); | |
3798 | ||
3799 | free_event(event); | |
3800 | put_event(parent_event); | |
3801 | } | |
3802 | ||
3803 | raw_spin_lock_irq(&ctx->lock); | |
3804 | ctx->orphans_remove_sched = false; | |
3805 | raw_spin_unlock_irq(&ctx->lock); | |
3806 | mutex_unlock(&ctx->mutex); | |
3807 | ||
3808 | put_ctx(ctx); | |
3809 | } | |
3810 | ||
59ed446f | 3811 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3812 | { |
cdd6c482 | 3813 | struct perf_event *child; |
e53c0994 PZ |
3814 | u64 total = 0; |
3815 | ||
59ed446f PZ |
3816 | *enabled = 0; |
3817 | *running = 0; | |
3818 | ||
6f10581a | 3819 | mutex_lock(&event->child_mutex); |
01add3ea | 3820 | |
7d88962e | 3821 | (void)perf_event_read(event, false); |
01add3ea SB |
3822 | total += perf_event_count(event); |
3823 | ||
59ed446f PZ |
3824 | *enabled += event->total_time_enabled + |
3825 | atomic64_read(&event->child_total_time_enabled); | |
3826 | *running += event->total_time_running + | |
3827 | atomic64_read(&event->child_total_time_running); | |
3828 | ||
3829 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3830 | (void)perf_event_read(child, false); |
01add3ea | 3831 | total += perf_event_count(child); |
59ed446f PZ |
3832 | *enabled += child->total_time_enabled; |
3833 | *running += child->total_time_running; | |
3834 | } | |
6f10581a | 3835 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3836 | |
3837 | return total; | |
3838 | } | |
fb0459d7 | 3839 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3840 | |
7d88962e | 3841 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3842 | u64 read_format, u64 *values) |
3dab77fb | 3843 | { |
fa8c2693 PZ |
3844 | struct perf_event *sub; |
3845 | int n = 1; /* skip @nr */ | |
7d88962e | 3846 | int ret; |
f63a8daa | 3847 | |
7d88962e SB |
3848 | ret = perf_event_read(leader, true); |
3849 | if (ret) | |
3850 | return ret; | |
abf4868b | 3851 | |
fa8c2693 PZ |
3852 | /* |
3853 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3854 | * will be identical to those of the leader, so we only publish one | |
3855 | * set. | |
3856 | */ | |
3857 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3858 | values[n++] += leader->total_time_enabled + | |
3859 | atomic64_read(&leader->child_total_time_enabled); | |
3860 | } | |
3dab77fb | 3861 | |
fa8c2693 PZ |
3862 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3863 | values[n++] += leader->total_time_running + | |
3864 | atomic64_read(&leader->child_total_time_running); | |
3865 | } | |
3866 | ||
3867 | /* | |
3868 | * Write {count,id} tuples for every sibling. | |
3869 | */ | |
3870 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3871 | if (read_format & PERF_FORMAT_ID) |
3872 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3873 | |
fa8c2693 PZ |
3874 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3875 | values[n++] += perf_event_count(sub); | |
3876 | if (read_format & PERF_FORMAT_ID) | |
3877 | values[n++] = primary_event_id(sub); | |
3878 | } | |
7d88962e SB |
3879 | |
3880 | return 0; | |
fa8c2693 | 3881 | } |
3dab77fb | 3882 | |
fa8c2693 PZ |
3883 | static int perf_read_group(struct perf_event *event, |
3884 | u64 read_format, char __user *buf) | |
3885 | { | |
3886 | struct perf_event *leader = event->group_leader, *child; | |
3887 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3888 | int ret; |
fa8c2693 | 3889 | u64 *values; |
3dab77fb | 3890 | |
fa8c2693 | 3891 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3892 | |
fa8c2693 PZ |
3893 | values = kzalloc(event->read_size, GFP_KERNEL); |
3894 | if (!values) | |
3895 | return -ENOMEM; | |
3dab77fb | 3896 | |
fa8c2693 PZ |
3897 | values[0] = 1 + leader->nr_siblings; |
3898 | ||
3899 | /* | |
3900 | * By locking the child_mutex of the leader we effectively | |
3901 | * lock the child list of all siblings.. XXX explain how. | |
3902 | */ | |
3903 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3904 | |
7d88962e SB |
3905 | ret = __perf_read_group_add(leader, read_format, values); |
3906 | if (ret) | |
3907 | goto unlock; | |
3908 | ||
3909 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3910 | ret = __perf_read_group_add(child, read_format, values); | |
3911 | if (ret) | |
3912 | goto unlock; | |
3913 | } | |
abf4868b | 3914 | |
fa8c2693 | 3915 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3916 | |
7d88962e | 3917 | ret = event->read_size; |
fa8c2693 PZ |
3918 | if (copy_to_user(buf, values, event->read_size)) |
3919 | ret = -EFAULT; | |
7d88962e | 3920 | goto out; |
fa8c2693 | 3921 | |
7d88962e SB |
3922 | unlock: |
3923 | mutex_unlock(&leader->child_mutex); | |
3924 | out: | |
fa8c2693 | 3925 | kfree(values); |
abf4868b | 3926 | return ret; |
3dab77fb PZ |
3927 | } |
3928 | ||
b15f495b | 3929 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3930 | u64 read_format, char __user *buf) |
3931 | { | |
59ed446f | 3932 | u64 enabled, running; |
3dab77fb PZ |
3933 | u64 values[4]; |
3934 | int n = 0; | |
3935 | ||
59ed446f PZ |
3936 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3937 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3938 | values[n++] = enabled; | |
3939 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3940 | values[n++] = running; | |
3dab77fb | 3941 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3942 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3943 | |
3944 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3945 | return -EFAULT; | |
3946 | ||
3947 | return n * sizeof(u64); | |
3948 | } | |
3949 | ||
dc633982 JO |
3950 | static bool is_event_hup(struct perf_event *event) |
3951 | { | |
3952 | bool no_children; | |
3953 | ||
3954 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3955 | return false; | |
3956 | ||
3957 | mutex_lock(&event->child_mutex); | |
3958 | no_children = list_empty(&event->child_list); | |
3959 | mutex_unlock(&event->child_mutex); | |
3960 | return no_children; | |
3961 | } | |
3962 | ||
0793a61d | 3963 | /* |
cdd6c482 | 3964 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3965 | */ |
3966 | static ssize_t | |
b15f495b | 3967 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3968 | { |
cdd6c482 | 3969 | u64 read_format = event->attr.read_format; |
3dab77fb | 3970 | int ret; |
0793a61d | 3971 | |
3b6f9e5c | 3972 | /* |
cdd6c482 | 3973 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
3974 | * error state (i.e. because it was pinned but it couldn't be |
3975 | * scheduled on to the CPU at some point). | |
3976 | */ | |
cdd6c482 | 3977 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
3978 | return 0; |
3979 | ||
c320c7b7 | 3980 | if (count < event->read_size) |
3dab77fb PZ |
3981 | return -ENOSPC; |
3982 | ||
cdd6c482 | 3983 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 3984 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 3985 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 3986 | else |
b15f495b | 3987 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 3988 | |
3dab77fb | 3989 | return ret; |
0793a61d TG |
3990 | } |
3991 | ||
0793a61d TG |
3992 | static ssize_t |
3993 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
3994 | { | |
cdd6c482 | 3995 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
3996 | struct perf_event_context *ctx; |
3997 | int ret; | |
0793a61d | 3998 | |
f63a8daa | 3999 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4000 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4001 | perf_event_ctx_unlock(event, ctx); |
4002 | ||
4003 | return ret; | |
0793a61d TG |
4004 | } |
4005 | ||
4006 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4007 | { | |
cdd6c482 | 4008 | struct perf_event *event = file->private_data; |
76369139 | 4009 | struct ring_buffer *rb; |
61b67684 | 4010 | unsigned int events = POLLHUP; |
c7138f37 | 4011 | |
e708d7ad | 4012 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4013 | |
dc633982 | 4014 | if (is_event_hup(event)) |
179033b3 | 4015 | return events; |
c7138f37 | 4016 | |
10c6db11 | 4017 | /* |
9bb5d40c PZ |
4018 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4019 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4020 | */ |
4021 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4022 | rb = event->rb; |
4023 | if (rb) | |
76369139 | 4024 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4025 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4026 | return events; |
4027 | } | |
4028 | ||
f63a8daa | 4029 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4030 | { |
7d88962e | 4031 | (void)perf_event_read(event, false); |
e7850595 | 4032 | local64_set(&event->count, 0); |
cdd6c482 | 4033 | perf_event_update_userpage(event); |
3df5edad PZ |
4034 | } |
4035 | ||
c93f7669 | 4036 | /* |
cdd6c482 IM |
4037 | * Holding the top-level event's child_mutex means that any |
4038 | * descendant process that has inherited this event will block | |
4039 | * in sync_child_event if it goes to exit, thus satisfying the | |
4040 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 4041 | */ |
cdd6c482 IM |
4042 | static void perf_event_for_each_child(struct perf_event *event, |
4043 | void (*func)(struct perf_event *)) | |
3df5edad | 4044 | { |
cdd6c482 | 4045 | struct perf_event *child; |
3df5edad | 4046 | |
cdd6c482 | 4047 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4048 | |
cdd6c482 IM |
4049 | mutex_lock(&event->child_mutex); |
4050 | func(event); | |
4051 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4052 | func(child); |
cdd6c482 | 4053 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4054 | } |
4055 | ||
cdd6c482 IM |
4056 | static void perf_event_for_each(struct perf_event *event, |
4057 | void (*func)(struct perf_event *)) | |
3df5edad | 4058 | { |
cdd6c482 IM |
4059 | struct perf_event_context *ctx = event->ctx; |
4060 | struct perf_event *sibling; | |
3df5edad | 4061 | |
f63a8daa PZ |
4062 | lockdep_assert_held(&ctx->mutex); |
4063 | ||
cdd6c482 | 4064 | event = event->group_leader; |
75f937f2 | 4065 | |
cdd6c482 | 4066 | perf_event_for_each_child(event, func); |
cdd6c482 | 4067 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4068 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4069 | } |
4070 | ||
c7999c6f PZ |
4071 | struct period_event { |
4072 | struct perf_event *event; | |
08247e31 | 4073 | u64 value; |
c7999c6f | 4074 | }; |
08247e31 | 4075 | |
0017960f PZ |
4076 | static void ___perf_event_period(void *info) |
4077 | { | |
4078 | struct period_event *pe = info; | |
4079 | struct perf_event *event = pe->event; | |
4080 | u64 value = pe->value; | |
4081 | ||
4082 | if (event->attr.freq) { | |
4083 | event->attr.sample_freq = value; | |
4084 | } else { | |
4085 | event->attr.sample_period = value; | |
4086 | event->hw.sample_period = value; | |
4087 | } | |
4088 | ||
4089 | local64_set(&event->hw.period_left, 0); | |
4090 | } | |
4091 | ||
c7999c6f PZ |
4092 | static int __perf_event_period(void *info) |
4093 | { | |
4094 | struct period_event *pe = info; | |
4095 | struct perf_event *event = pe->event; | |
4096 | struct perf_event_context *ctx = event->ctx; | |
4097 | u64 value = pe->value; | |
4098 | bool active; | |
08247e31 | 4099 | |
c7999c6f | 4100 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 4101 | if (event->attr.freq) { |
cdd6c482 | 4102 | event->attr.sample_freq = value; |
08247e31 | 4103 | } else { |
cdd6c482 IM |
4104 | event->attr.sample_period = value; |
4105 | event->hw.sample_period = value; | |
08247e31 | 4106 | } |
bad7192b PZ |
4107 | |
4108 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4109 | if (active) { | |
4110 | perf_pmu_disable(ctx->pmu); | |
4111 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4112 | } | |
4113 | ||
4114 | local64_set(&event->hw.period_left, 0); | |
4115 | ||
4116 | if (active) { | |
4117 | event->pmu->start(event, PERF_EF_RELOAD); | |
4118 | perf_pmu_enable(ctx->pmu); | |
4119 | } | |
c7999c6f | 4120 | raw_spin_unlock(&ctx->lock); |
bad7192b | 4121 | |
c7999c6f PZ |
4122 | return 0; |
4123 | } | |
4124 | ||
4125 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4126 | { | |
4127 | struct period_event pe = { .event = event, }; | |
c7999c6f PZ |
4128 | u64 value; |
4129 | ||
4130 | if (!is_sampling_event(event)) | |
4131 | return -EINVAL; | |
4132 | ||
4133 | if (copy_from_user(&value, arg, sizeof(value))) | |
4134 | return -EFAULT; | |
4135 | ||
4136 | if (!value) | |
4137 | return -EINVAL; | |
4138 | ||
4139 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4140 | return -EINVAL; | |
4141 | ||
c7999c6f PZ |
4142 | pe.value = value; |
4143 | ||
0017960f PZ |
4144 | event_function_call(event, __perf_event_period, |
4145 | ___perf_event_period, &pe); | |
08247e31 | 4146 | |
c7999c6f | 4147 | return 0; |
08247e31 PZ |
4148 | } |
4149 | ||
ac9721f3 PZ |
4150 | static const struct file_operations perf_fops; |
4151 | ||
2903ff01 | 4152 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4153 | { |
2903ff01 AV |
4154 | struct fd f = fdget(fd); |
4155 | if (!f.file) | |
4156 | return -EBADF; | |
ac9721f3 | 4157 | |
2903ff01 AV |
4158 | if (f.file->f_op != &perf_fops) { |
4159 | fdput(f); | |
4160 | return -EBADF; | |
ac9721f3 | 4161 | } |
2903ff01 AV |
4162 | *p = f; |
4163 | return 0; | |
ac9721f3 PZ |
4164 | } |
4165 | ||
4166 | static int perf_event_set_output(struct perf_event *event, | |
4167 | struct perf_event *output_event); | |
6fb2915d | 4168 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4169 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4170 | |
f63a8daa | 4171 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4172 | { |
cdd6c482 | 4173 | void (*func)(struct perf_event *); |
3df5edad | 4174 | u32 flags = arg; |
d859e29f PM |
4175 | |
4176 | switch (cmd) { | |
cdd6c482 | 4177 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4178 | func = _perf_event_enable; |
d859e29f | 4179 | break; |
cdd6c482 | 4180 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4181 | func = _perf_event_disable; |
79f14641 | 4182 | break; |
cdd6c482 | 4183 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4184 | func = _perf_event_reset; |
6de6a7b9 | 4185 | break; |
3df5edad | 4186 | |
cdd6c482 | 4187 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4188 | return _perf_event_refresh(event, arg); |
08247e31 | 4189 | |
cdd6c482 IM |
4190 | case PERF_EVENT_IOC_PERIOD: |
4191 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4192 | |
cf4957f1 JO |
4193 | case PERF_EVENT_IOC_ID: |
4194 | { | |
4195 | u64 id = primary_event_id(event); | |
4196 | ||
4197 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4198 | return -EFAULT; | |
4199 | return 0; | |
4200 | } | |
4201 | ||
cdd6c482 | 4202 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4203 | { |
ac9721f3 | 4204 | int ret; |
ac9721f3 | 4205 | if (arg != -1) { |
2903ff01 AV |
4206 | struct perf_event *output_event; |
4207 | struct fd output; | |
4208 | ret = perf_fget_light(arg, &output); | |
4209 | if (ret) | |
4210 | return ret; | |
4211 | output_event = output.file->private_data; | |
4212 | ret = perf_event_set_output(event, output_event); | |
4213 | fdput(output); | |
4214 | } else { | |
4215 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4216 | } |
ac9721f3 PZ |
4217 | return ret; |
4218 | } | |
a4be7c27 | 4219 | |
6fb2915d LZ |
4220 | case PERF_EVENT_IOC_SET_FILTER: |
4221 | return perf_event_set_filter(event, (void __user *)arg); | |
4222 | ||
2541517c AS |
4223 | case PERF_EVENT_IOC_SET_BPF: |
4224 | return perf_event_set_bpf_prog(event, arg); | |
4225 | ||
d859e29f | 4226 | default: |
3df5edad | 4227 | return -ENOTTY; |
d859e29f | 4228 | } |
3df5edad PZ |
4229 | |
4230 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4231 | perf_event_for_each(event, func); |
3df5edad | 4232 | else |
cdd6c482 | 4233 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4234 | |
4235 | return 0; | |
d859e29f PM |
4236 | } |
4237 | ||
f63a8daa PZ |
4238 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4239 | { | |
4240 | struct perf_event *event = file->private_data; | |
4241 | struct perf_event_context *ctx; | |
4242 | long ret; | |
4243 | ||
4244 | ctx = perf_event_ctx_lock(event); | |
4245 | ret = _perf_ioctl(event, cmd, arg); | |
4246 | perf_event_ctx_unlock(event, ctx); | |
4247 | ||
4248 | return ret; | |
4249 | } | |
4250 | ||
b3f20785 PM |
4251 | #ifdef CONFIG_COMPAT |
4252 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4253 | unsigned long arg) | |
4254 | { | |
4255 | switch (_IOC_NR(cmd)) { | |
4256 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4257 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4258 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4259 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4260 | cmd &= ~IOCSIZE_MASK; | |
4261 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4262 | } | |
4263 | break; | |
4264 | } | |
4265 | return perf_ioctl(file, cmd, arg); | |
4266 | } | |
4267 | #else | |
4268 | # define perf_compat_ioctl NULL | |
4269 | #endif | |
4270 | ||
cdd6c482 | 4271 | int perf_event_task_enable(void) |
771d7cde | 4272 | { |
f63a8daa | 4273 | struct perf_event_context *ctx; |
cdd6c482 | 4274 | struct perf_event *event; |
771d7cde | 4275 | |
cdd6c482 | 4276 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4277 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4278 | ctx = perf_event_ctx_lock(event); | |
4279 | perf_event_for_each_child(event, _perf_event_enable); | |
4280 | perf_event_ctx_unlock(event, ctx); | |
4281 | } | |
cdd6c482 | 4282 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4283 | |
4284 | return 0; | |
4285 | } | |
4286 | ||
cdd6c482 | 4287 | int perf_event_task_disable(void) |
771d7cde | 4288 | { |
f63a8daa | 4289 | struct perf_event_context *ctx; |
cdd6c482 | 4290 | struct perf_event *event; |
771d7cde | 4291 | |
cdd6c482 | 4292 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4293 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4294 | ctx = perf_event_ctx_lock(event); | |
4295 | perf_event_for_each_child(event, _perf_event_disable); | |
4296 | perf_event_ctx_unlock(event, ctx); | |
4297 | } | |
cdd6c482 | 4298 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4299 | |
4300 | return 0; | |
4301 | } | |
4302 | ||
cdd6c482 | 4303 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4304 | { |
a4eaf7f1 PZ |
4305 | if (event->hw.state & PERF_HES_STOPPED) |
4306 | return 0; | |
4307 | ||
cdd6c482 | 4308 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4309 | return 0; |
4310 | ||
35edc2a5 | 4311 | return event->pmu->event_idx(event); |
194002b2 PZ |
4312 | } |
4313 | ||
c4794295 | 4314 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4315 | u64 *now, |
7f310a5d EM |
4316 | u64 *enabled, |
4317 | u64 *running) | |
c4794295 | 4318 | { |
e3f3541c | 4319 | u64 ctx_time; |
c4794295 | 4320 | |
e3f3541c PZ |
4321 | *now = perf_clock(); |
4322 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4323 | *enabled = ctx_time - event->tstamp_enabled; |
4324 | *running = ctx_time - event->tstamp_running; | |
4325 | } | |
4326 | ||
fa731587 PZ |
4327 | static void perf_event_init_userpage(struct perf_event *event) |
4328 | { | |
4329 | struct perf_event_mmap_page *userpg; | |
4330 | struct ring_buffer *rb; | |
4331 | ||
4332 | rcu_read_lock(); | |
4333 | rb = rcu_dereference(event->rb); | |
4334 | if (!rb) | |
4335 | goto unlock; | |
4336 | ||
4337 | userpg = rb->user_page; | |
4338 | ||
4339 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4340 | userpg->cap_bit0_is_deprecated = 1; | |
4341 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4342 | userpg->data_offset = PAGE_SIZE; |
4343 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4344 | |
4345 | unlock: | |
4346 | rcu_read_unlock(); | |
4347 | } | |
4348 | ||
c1317ec2 AL |
4349 | void __weak arch_perf_update_userpage( |
4350 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4351 | { |
4352 | } | |
4353 | ||
38ff667b PZ |
4354 | /* |
4355 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4356 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4357 | * code calls this from NMI context. | |
4358 | */ | |
cdd6c482 | 4359 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4360 | { |
cdd6c482 | 4361 | struct perf_event_mmap_page *userpg; |
76369139 | 4362 | struct ring_buffer *rb; |
e3f3541c | 4363 | u64 enabled, running, now; |
38ff667b PZ |
4364 | |
4365 | rcu_read_lock(); | |
5ec4c599 PZ |
4366 | rb = rcu_dereference(event->rb); |
4367 | if (!rb) | |
4368 | goto unlock; | |
4369 | ||
0d641208 EM |
4370 | /* |
4371 | * compute total_time_enabled, total_time_running | |
4372 | * based on snapshot values taken when the event | |
4373 | * was last scheduled in. | |
4374 | * | |
4375 | * we cannot simply called update_context_time() | |
4376 | * because of locking issue as we can be called in | |
4377 | * NMI context | |
4378 | */ | |
e3f3541c | 4379 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4380 | |
76369139 | 4381 | userpg = rb->user_page; |
7b732a75 PZ |
4382 | /* |
4383 | * Disable preemption so as to not let the corresponding user-space | |
4384 | * spin too long if we get preempted. | |
4385 | */ | |
4386 | preempt_disable(); | |
37d81828 | 4387 | ++userpg->lock; |
92f22a38 | 4388 | barrier(); |
cdd6c482 | 4389 | userpg->index = perf_event_index(event); |
b5e58793 | 4390 | userpg->offset = perf_event_count(event); |
365a4038 | 4391 | if (userpg->index) |
e7850595 | 4392 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4393 | |
0d641208 | 4394 | userpg->time_enabled = enabled + |
cdd6c482 | 4395 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4396 | |
0d641208 | 4397 | userpg->time_running = running + |
cdd6c482 | 4398 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4399 | |
c1317ec2 | 4400 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4401 | |
92f22a38 | 4402 | barrier(); |
37d81828 | 4403 | ++userpg->lock; |
7b732a75 | 4404 | preempt_enable(); |
38ff667b | 4405 | unlock: |
7b732a75 | 4406 | rcu_read_unlock(); |
37d81828 PM |
4407 | } |
4408 | ||
906010b2 PZ |
4409 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4410 | { | |
4411 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4412 | struct ring_buffer *rb; |
906010b2 PZ |
4413 | int ret = VM_FAULT_SIGBUS; |
4414 | ||
4415 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4416 | if (vmf->pgoff == 0) | |
4417 | ret = 0; | |
4418 | return ret; | |
4419 | } | |
4420 | ||
4421 | rcu_read_lock(); | |
76369139 FW |
4422 | rb = rcu_dereference(event->rb); |
4423 | if (!rb) | |
906010b2 PZ |
4424 | goto unlock; |
4425 | ||
4426 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4427 | goto unlock; | |
4428 | ||
76369139 | 4429 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4430 | if (!vmf->page) |
4431 | goto unlock; | |
4432 | ||
4433 | get_page(vmf->page); | |
4434 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4435 | vmf->page->index = vmf->pgoff; | |
4436 | ||
4437 | ret = 0; | |
4438 | unlock: | |
4439 | rcu_read_unlock(); | |
4440 | ||
4441 | return ret; | |
4442 | } | |
4443 | ||
10c6db11 PZ |
4444 | static void ring_buffer_attach(struct perf_event *event, |
4445 | struct ring_buffer *rb) | |
4446 | { | |
b69cf536 | 4447 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4448 | unsigned long flags; |
4449 | ||
b69cf536 PZ |
4450 | if (event->rb) { |
4451 | /* | |
4452 | * Should be impossible, we set this when removing | |
4453 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4454 | */ | |
4455 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4456 | |
b69cf536 | 4457 | old_rb = event->rb; |
b69cf536 PZ |
4458 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4459 | list_del_rcu(&event->rb_entry); | |
4460 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4461 | |
2f993cf0 ON |
4462 | event->rcu_batches = get_state_synchronize_rcu(); |
4463 | event->rcu_pending = 1; | |
b69cf536 | 4464 | } |
10c6db11 | 4465 | |
b69cf536 | 4466 | if (rb) { |
2f993cf0 ON |
4467 | if (event->rcu_pending) { |
4468 | cond_synchronize_rcu(event->rcu_batches); | |
4469 | event->rcu_pending = 0; | |
4470 | } | |
4471 | ||
b69cf536 PZ |
4472 | spin_lock_irqsave(&rb->event_lock, flags); |
4473 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4474 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4475 | } | |
4476 | ||
4477 | rcu_assign_pointer(event->rb, rb); | |
4478 | ||
4479 | if (old_rb) { | |
4480 | ring_buffer_put(old_rb); | |
4481 | /* | |
4482 | * Since we detached before setting the new rb, so that we | |
4483 | * could attach the new rb, we could have missed a wakeup. | |
4484 | * Provide it now. | |
4485 | */ | |
4486 | wake_up_all(&event->waitq); | |
4487 | } | |
10c6db11 PZ |
4488 | } |
4489 | ||
4490 | static void ring_buffer_wakeup(struct perf_event *event) | |
4491 | { | |
4492 | struct ring_buffer *rb; | |
4493 | ||
4494 | rcu_read_lock(); | |
4495 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4496 | if (rb) { |
4497 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4498 | wake_up_all(&event->waitq); | |
4499 | } | |
10c6db11 PZ |
4500 | rcu_read_unlock(); |
4501 | } | |
4502 | ||
fdc26706 | 4503 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4504 | { |
76369139 | 4505 | struct ring_buffer *rb; |
7b732a75 | 4506 | |
ac9721f3 | 4507 | rcu_read_lock(); |
76369139 FW |
4508 | rb = rcu_dereference(event->rb); |
4509 | if (rb) { | |
4510 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4511 | rb = NULL; | |
ac9721f3 PZ |
4512 | } |
4513 | rcu_read_unlock(); | |
4514 | ||
76369139 | 4515 | return rb; |
ac9721f3 PZ |
4516 | } |
4517 | ||
fdc26706 | 4518 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4519 | { |
76369139 | 4520 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4521 | return; |
7b732a75 | 4522 | |
9bb5d40c | 4523 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4524 | |
76369139 | 4525 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4526 | } |
4527 | ||
4528 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4529 | { | |
cdd6c482 | 4530 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4531 | |
cdd6c482 | 4532 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4533 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4534 | |
45bfb2e5 PZ |
4535 | if (vma->vm_pgoff) |
4536 | atomic_inc(&event->rb->aux_mmap_count); | |
4537 | ||
1e0fb9ec AL |
4538 | if (event->pmu->event_mapped) |
4539 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4540 | } |
4541 | ||
9bb5d40c PZ |
4542 | /* |
4543 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4544 | * event, or through other events by use of perf_event_set_output(). | |
4545 | * | |
4546 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4547 | * the buffer here, where we still have a VM context. This means we need | |
4548 | * to detach all events redirecting to us. | |
4549 | */ | |
7b732a75 PZ |
4550 | static void perf_mmap_close(struct vm_area_struct *vma) |
4551 | { | |
cdd6c482 | 4552 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4553 | |
b69cf536 | 4554 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4555 | struct user_struct *mmap_user = rb->mmap_user; |
4556 | int mmap_locked = rb->mmap_locked; | |
4557 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4558 | |
1e0fb9ec AL |
4559 | if (event->pmu->event_unmapped) |
4560 | event->pmu->event_unmapped(event); | |
4561 | ||
45bfb2e5 PZ |
4562 | /* |
4563 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4564 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4565 | * serialize with perf_mmap here. | |
4566 | */ | |
4567 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4568 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4569 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4570 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4571 | ||
4572 | rb_free_aux(rb); | |
4573 | mutex_unlock(&event->mmap_mutex); | |
4574 | } | |
4575 | ||
9bb5d40c PZ |
4576 | atomic_dec(&rb->mmap_count); |
4577 | ||
4578 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4579 | goto out_put; |
9bb5d40c | 4580 | |
b69cf536 | 4581 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4582 | mutex_unlock(&event->mmap_mutex); |
4583 | ||
4584 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4585 | if (atomic_read(&rb->mmap_count)) |
4586 | goto out_put; | |
ac9721f3 | 4587 | |
9bb5d40c PZ |
4588 | /* |
4589 | * No other mmap()s, detach from all other events that might redirect | |
4590 | * into the now unreachable buffer. Somewhat complicated by the | |
4591 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4592 | */ | |
4593 | again: | |
4594 | rcu_read_lock(); | |
4595 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4596 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4597 | /* | |
4598 | * This event is en-route to free_event() which will | |
4599 | * detach it and remove it from the list. | |
4600 | */ | |
4601 | continue; | |
4602 | } | |
4603 | rcu_read_unlock(); | |
789f90fc | 4604 | |
9bb5d40c PZ |
4605 | mutex_lock(&event->mmap_mutex); |
4606 | /* | |
4607 | * Check we didn't race with perf_event_set_output() which can | |
4608 | * swizzle the rb from under us while we were waiting to | |
4609 | * acquire mmap_mutex. | |
4610 | * | |
4611 | * If we find a different rb; ignore this event, a next | |
4612 | * iteration will no longer find it on the list. We have to | |
4613 | * still restart the iteration to make sure we're not now | |
4614 | * iterating the wrong list. | |
4615 | */ | |
b69cf536 PZ |
4616 | if (event->rb == rb) |
4617 | ring_buffer_attach(event, NULL); | |
4618 | ||
cdd6c482 | 4619 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4620 | put_event(event); |
ac9721f3 | 4621 | |
9bb5d40c PZ |
4622 | /* |
4623 | * Restart the iteration; either we're on the wrong list or | |
4624 | * destroyed its integrity by doing a deletion. | |
4625 | */ | |
4626 | goto again; | |
7b732a75 | 4627 | } |
9bb5d40c PZ |
4628 | rcu_read_unlock(); |
4629 | ||
4630 | /* | |
4631 | * It could be there's still a few 0-ref events on the list; they'll | |
4632 | * get cleaned up by free_event() -- they'll also still have their | |
4633 | * ref on the rb and will free it whenever they are done with it. | |
4634 | * | |
4635 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4636 | * undo the VM accounting. | |
4637 | */ | |
4638 | ||
4639 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4640 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4641 | free_uid(mmap_user); | |
4642 | ||
b69cf536 | 4643 | out_put: |
9bb5d40c | 4644 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4645 | } |
4646 | ||
f0f37e2f | 4647 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4648 | .open = perf_mmap_open, |
45bfb2e5 | 4649 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4650 | .fault = perf_mmap_fault, |
4651 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4652 | }; |
4653 | ||
4654 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4655 | { | |
cdd6c482 | 4656 | struct perf_event *event = file->private_data; |
22a4f650 | 4657 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4658 | struct user_struct *user = current_user(); |
22a4f650 | 4659 | unsigned long locked, lock_limit; |
45bfb2e5 | 4660 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4661 | unsigned long vma_size; |
4662 | unsigned long nr_pages; | |
45bfb2e5 | 4663 | long user_extra = 0, extra = 0; |
d57e34fd | 4664 | int ret = 0, flags = 0; |
37d81828 | 4665 | |
c7920614 PZ |
4666 | /* |
4667 | * Don't allow mmap() of inherited per-task counters. This would | |
4668 | * create a performance issue due to all children writing to the | |
76369139 | 4669 | * same rb. |
c7920614 PZ |
4670 | */ |
4671 | if (event->cpu == -1 && event->attr.inherit) | |
4672 | return -EINVAL; | |
4673 | ||
43a21ea8 | 4674 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4675 | return -EINVAL; |
7b732a75 PZ |
4676 | |
4677 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4678 | |
4679 | if (vma->vm_pgoff == 0) { | |
4680 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4681 | } else { | |
4682 | /* | |
4683 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4684 | * mapped, all subsequent mappings should have the same size | |
4685 | * and offset. Must be above the normal perf buffer. | |
4686 | */ | |
4687 | u64 aux_offset, aux_size; | |
4688 | ||
4689 | if (!event->rb) | |
4690 | return -EINVAL; | |
4691 | ||
4692 | nr_pages = vma_size / PAGE_SIZE; | |
4693 | ||
4694 | mutex_lock(&event->mmap_mutex); | |
4695 | ret = -EINVAL; | |
4696 | ||
4697 | rb = event->rb; | |
4698 | if (!rb) | |
4699 | goto aux_unlock; | |
4700 | ||
4701 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4702 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4703 | ||
4704 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4705 | goto aux_unlock; | |
4706 | ||
4707 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4708 | goto aux_unlock; | |
4709 | ||
4710 | /* already mapped with a different offset */ | |
4711 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4712 | goto aux_unlock; | |
4713 | ||
4714 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4715 | goto aux_unlock; | |
4716 | ||
4717 | /* already mapped with a different size */ | |
4718 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4719 | goto aux_unlock; | |
4720 | ||
4721 | if (!is_power_of_2(nr_pages)) | |
4722 | goto aux_unlock; | |
4723 | ||
4724 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4725 | goto aux_unlock; | |
4726 | ||
4727 | if (rb_has_aux(rb)) { | |
4728 | atomic_inc(&rb->aux_mmap_count); | |
4729 | ret = 0; | |
4730 | goto unlock; | |
4731 | } | |
4732 | ||
4733 | atomic_set(&rb->aux_mmap_count, 1); | |
4734 | user_extra = nr_pages; | |
4735 | ||
4736 | goto accounting; | |
4737 | } | |
7b732a75 | 4738 | |
7730d865 | 4739 | /* |
76369139 | 4740 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4741 | * can do bitmasks instead of modulo. |
4742 | */ | |
2ed11312 | 4743 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4744 | return -EINVAL; |
4745 | ||
7b732a75 | 4746 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4747 | return -EINVAL; |
4748 | ||
cdd6c482 | 4749 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4750 | again: |
cdd6c482 | 4751 | mutex_lock(&event->mmap_mutex); |
76369139 | 4752 | if (event->rb) { |
9bb5d40c | 4753 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4754 | ret = -EINVAL; |
9bb5d40c PZ |
4755 | goto unlock; |
4756 | } | |
4757 | ||
4758 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4759 | /* | |
4760 | * Raced against perf_mmap_close() through | |
4761 | * perf_event_set_output(). Try again, hope for better | |
4762 | * luck. | |
4763 | */ | |
4764 | mutex_unlock(&event->mmap_mutex); | |
4765 | goto again; | |
4766 | } | |
4767 | ||
ebb3c4c4 PZ |
4768 | goto unlock; |
4769 | } | |
4770 | ||
789f90fc | 4771 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4772 | |
4773 | accounting: | |
cdd6c482 | 4774 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4775 | |
4776 | /* | |
4777 | * Increase the limit linearly with more CPUs: | |
4778 | */ | |
4779 | user_lock_limit *= num_online_cpus(); | |
4780 | ||
789f90fc | 4781 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4782 | |
789f90fc PZ |
4783 | if (user_locked > user_lock_limit) |
4784 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4785 | |
78d7d407 | 4786 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4787 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4788 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4789 | |
459ec28a IM |
4790 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4791 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4792 | ret = -EPERM; |
4793 | goto unlock; | |
4794 | } | |
7b732a75 | 4795 | |
45bfb2e5 | 4796 | WARN_ON(!rb && event->rb); |
906010b2 | 4797 | |
d57e34fd | 4798 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4799 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4800 | |
76369139 | 4801 | if (!rb) { |
45bfb2e5 PZ |
4802 | rb = rb_alloc(nr_pages, |
4803 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4804 | event->cpu, flags); | |
26cb63ad | 4805 | |
45bfb2e5 PZ |
4806 | if (!rb) { |
4807 | ret = -ENOMEM; | |
4808 | goto unlock; | |
4809 | } | |
43a21ea8 | 4810 | |
45bfb2e5 PZ |
4811 | atomic_set(&rb->mmap_count, 1); |
4812 | rb->mmap_user = get_current_user(); | |
4813 | rb->mmap_locked = extra; | |
26cb63ad | 4814 | |
45bfb2e5 | 4815 | ring_buffer_attach(event, rb); |
ac9721f3 | 4816 | |
45bfb2e5 PZ |
4817 | perf_event_init_userpage(event); |
4818 | perf_event_update_userpage(event); | |
4819 | } else { | |
1a594131 AS |
4820 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4821 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4822 | if (!ret) |
4823 | rb->aux_mmap_locked = extra; | |
4824 | } | |
9a0f05cb | 4825 | |
ebb3c4c4 | 4826 | unlock: |
45bfb2e5 PZ |
4827 | if (!ret) { |
4828 | atomic_long_add(user_extra, &user->locked_vm); | |
4829 | vma->vm_mm->pinned_vm += extra; | |
4830 | ||
ac9721f3 | 4831 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4832 | } else if (rb) { |
4833 | atomic_dec(&rb->mmap_count); | |
4834 | } | |
4835 | aux_unlock: | |
cdd6c482 | 4836 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4837 | |
9bb5d40c PZ |
4838 | /* |
4839 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4840 | * vma. | |
4841 | */ | |
26cb63ad | 4842 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4843 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4844 | |
1e0fb9ec AL |
4845 | if (event->pmu->event_mapped) |
4846 | event->pmu->event_mapped(event); | |
4847 | ||
7b732a75 | 4848 | return ret; |
37d81828 PM |
4849 | } |
4850 | ||
3c446b3d PZ |
4851 | static int perf_fasync(int fd, struct file *filp, int on) |
4852 | { | |
496ad9aa | 4853 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4854 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4855 | int retval; |
4856 | ||
4857 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4858 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4859 | mutex_unlock(&inode->i_mutex); |
4860 | ||
4861 | if (retval < 0) | |
4862 | return retval; | |
4863 | ||
4864 | return 0; | |
4865 | } | |
4866 | ||
0793a61d | 4867 | static const struct file_operations perf_fops = { |
3326c1ce | 4868 | .llseek = no_llseek, |
0793a61d TG |
4869 | .release = perf_release, |
4870 | .read = perf_read, | |
4871 | .poll = perf_poll, | |
d859e29f | 4872 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4873 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4874 | .mmap = perf_mmap, |
3c446b3d | 4875 | .fasync = perf_fasync, |
0793a61d TG |
4876 | }; |
4877 | ||
925d519a | 4878 | /* |
cdd6c482 | 4879 | * Perf event wakeup |
925d519a PZ |
4880 | * |
4881 | * If there's data, ensure we set the poll() state and publish everything | |
4882 | * to user-space before waking everybody up. | |
4883 | */ | |
4884 | ||
fed66e2c PZ |
4885 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4886 | { | |
4887 | /* only the parent has fasync state */ | |
4888 | if (event->parent) | |
4889 | event = event->parent; | |
4890 | return &event->fasync; | |
4891 | } | |
4892 | ||
cdd6c482 | 4893 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4894 | { |
10c6db11 | 4895 | ring_buffer_wakeup(event); |
4c9e2542 | 4896 | |
cdd6c482 | 4897 | if (event->pending_kill) { |
fed66e2c | 4898 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4899 | event->pending_kill = 0; |
4c9e2542 | 4900 | } |
925d519a PZ |
4901 | } |
4902 | ||
e360adbe | 4903 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4904 | { |
cdd6c482 IM |
4905 | struct perf_event *event = container_of(entry, |
4906 | struct perf_event, pending); | |
d525211f PZ |
4907 | int rctx; |
4908 | ||
4909 | rctx = perf_swevent_get_recursion_context(); | |
4910 | /* | |
4911 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4912 | * and we won't recurse 'further'. | |
4913 | */ | |
79f14641 | 4914 | |
cdd6c482 IM |
4915 | if (event->pending_disable) { |
4916 | event->pending_disable = 0; | |
4917 | __perf_event_disable(event); | |
79f14641 PZ |
4918 | } |
4919 | ||
cdd6c482 IM |
4920 | if (event->pending_wakeup) { |
4921 | event->pending_wakeup = 0; | |
4922 | perf_event_wakeup(event); | |
79f14641 | 4923 | } |
d525211f PZ |
4924 | |
4925 | if (rctx >= 0) | |
4926 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4927 | } |
4928 | ||
39447b38 ZY |
4929 | /* |
4930 | * We assume there is only KVM supporting the callbacks. | |
4931 | * Later on, we might change it to a list if there is | |
4932 | * another virtualization implementation supporting the callbacks. | |
4933 | */ | |
4934 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4935 | ||
4936 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4937 | { | |
4938 | perf_guest_cbs = cbs; | |
4939 | return 0; | |
4940 | } | |
4941 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4942 | ||
4943 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4944 | { | |
4945 | perf_guest_cbs = NULL; | |
4946 | return 0; | |
4947 | } | |
4948 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4949 | ||
4018994f JO |
4950 | static void |
4951 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4952 | struct pt_regs *regs, u64 mask) | |
4953 | { | |
4954 | int bit; | |
4955 | ||
4956 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4957 | sizeof(mask) * BITS_PER_BYTE) { | |
4958 | u64 val; | |
4959 | ||
4960 | val = perf_reg_value(regs, bit); | |
4961 | perf_output_put(handle, val); | |
4962 | } | |
4963 | } | |
4964 | ||
60e2364e | 4965 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4966 | struct pt_regs *regs, |
4967 | struct pt_regs *regs_user_copy) | |
4018994f | 4968 | { |
88a7c26a AL |
4969 | if (user_mode(regs)) { |
4970 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4971 | regs_user->regs = regs; |
88a7c26a AL |
4972 | } else if (current->mm) { |
4973 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4974 | } else { |
4975 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4976 | regs_user->regs = NULL; | |
4018994f JO |
4977 | } |
4978 | } | |
4979 | ||
60e2364e SE |
4980 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
4981 | struct pt_regs *regs) | |
4982 | { | |
4983 | regs_intr->regs = regs; | |
4984 | regs_intr->abi = perf_reg_abi(current); | |
4985 | } | |
4986 | ||
4987 | ||
c5ebcedb JO |
4988 | /* |
4989 | * Get remaining task size from user stack pointer. | |
4990 | * | |
4991 | * It'd be better to take stack vma map and limit this more | |
4992 | * precisly, but there's no way to get it safely under interrupt, | |
4993 | * so using TASK_SIZE as limit. | |
4994 | */ | |
4995 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
4996 | { | |
4997 | unsigned long addr = perf_user_stack_pointer(regs); | |
4998 | ||
4999 | if (!addr || addr >= TASK_SIZE) | |
5000 | return 0; | |
5001 | ||
5002 | return TASK_SIZE - addr; | |
5003 | } | |
5004 | ||
5005 | static u16 | |
5006 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5007 | struct pt_regs *regs) | |
5008 | { | |
5009 | u64 task_size; | |
5010 | ||
5011 | /* No regs, no stack pointer, no dump. */ | |
5012 | if (!regs) | |
5013 | return 0; | |
5014 | ||
5015 | /* | |
5016 | * Check if we fit in with the requested stack size into the: | |
5017 | * - TASK_SIZE | |
5018 | * If we don't, we limit the size to the TASK_SIZE. | |
5019 | * | |
5020 | * - remaining sample size | |
5021 | * If we don't, we customize the stack size to | |
5022 | * fit in to the remaining sample size. | |
5023 | */ | |
5024 | ||
5025 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5026 | stack_size = min(stack_size, (u16) task_size); | |
5027 | ||
5028 | /* Current header size plus static size and dynamic size. */ | |
5029 | header_size += 2 * sizeof(u64); | |
5030 | ||
5031 | /* Do we fit in with the current stack dump size? */ | |
5032 | if ((u16) (header_size + stack_size) < header_size) { | |
5033 | /* | |
5034 | * If we overflow the maximum size for the sample, | |
5035 | * we customize the stack dump size to fit in. | |
5036 | */ | |
5037 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5038 | stack_size = round_up(stack_size, sizeof(u64)); | |
5039 | } | |
5040 | ||
5041 | return stack_size; | |
5042 | } | |
5043 | ||
5044 | static void | |
5045 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5046 | struct pt_regs *regs) | |
5047 | { | |
5048 | /* Case of a kernel thread, nothing to dump */ | |
5049 | if (!regs) { | |
5050 | u64 size = 0; | |
5051 | perf_output_put(handle, size); | |
5052 | } else { | |
5053 | unsigned long sp; | |
5054 | unsigned int rem; | |
5055 | u64 dyn_size; | |
5056 | ||
5057 | /* | |
5058 | * We dump: | |
5059 | * static size | |
5060 | * - the size requested by user or the best one we can fit | |
5061 | * in to the sample max size | |
5062 | * data | |
5063 | * - user stack dump data | |
5064 | * dynamic size | |
5065 | * - the actual dumped size | |
5066 | */ | |
5067 | ||
5068 | /* Static size. */ | |
5069 | perf_output_put(handle, dump_size); | |
5070 | ||
5071 | /* Data. */ | |
5072 | sp = perf_user_stack_pointer(regs); | |
5073 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5074 | dyn_size = dump_size - rem; | |
5075 | ||
5076 | perf_output_skip(handle, rem); | |
5077 | ||
5078 | /* Dynamic size. */ | |
5079 | perf_output_put(handle, dyn_size); | |
5080 | } | |
5081 | } | |
5082 | ||
c980d109 ACM |
5083 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5084 | struct perf_sample_data *data, | |
5085 | struct perf_event *event) | |
6844c09d ACM |
5086 | { |
5087 | u64 sample_type = event->attr.sample_type; | |
5088 | ||
5089 | data->type = sample_type; | |
5090 | header->size += event->id_header_size; | |
5091 | ||
5092 | if (sample_type & PERF_SAMPLE_TID) { | |
5093 | /* namespace issues */ | |
5094 | data->tid_entry.pid = perf_event_pid(event, current); | |
5095 | data->tid_entry.tid = perf_event_tid(event, current); | |
5096 | } | |
5097 | ||
5098 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5099 | data->time = perf_event_clock(event); |
6844c09d | 5100 | |
ff3d527c | 5101 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5102 | data->id = primary_event_id(event); |
5103 | ||
5104 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5105 | data->stream_id = event->id; | |
5106 | ||
5107 | if (sample_type & PERF_SAMPLE_CPU) { | |
5108 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5109 | data->cpu_entry.reserved = 0; | |
5110 | } | |
5111 | } | |
5112 | ||
76369139 FW |
5113 | void perf_event_header__init_id(struct perf_event_header *header, |
5114 | struct perf_sample_data *data, | |
5115 | struct perf_event *event) | |
c980d109 ACM |
5116 | { |
5117 | if (event->attr.sample_id_all) | |
5118 | __perf_event_header__init_id(header, data, event); | |
5119 | } | |
5120 | ||
5121 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5122 | struct perf_sample_data *data) | |
5123 | { | |
5124 | u64 sample_type = data->type; | |
5125 | ||
5126 | if (sample_type & PERF_SAMPLE_TID) | |
5127 | perf_output_put(handle, data->tid_entry); | |
5128 | ||
5129 | if (sample_type & PERF_SAMPLE_TIME) | |
5130 | perf_output_put(handle, data->time); | |
5131 | ||
5132 | if (sample_type & PERF_SAMPLE_ID) | |
5133 | perf_output_put(handle, data->id); | |
5134 | ||
5135 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5136 | perf_output_put(handle, data->stream_id); | |
5137 | ||
5138 | if (sample_type & PERF_SAMPLE_CPU) | |
5139 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5140 | |
5141 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5142 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5143 | } |
5144 | ||
76369139 FW |
5145 | void perf_event__output_id_sample(struct perf_event *event, |
5146 | struct perf_output_handle *handle, | |
5147 | struct perf_sample_data *sample) | |
c980d109 ACM |
5148 | { |
5149 | if (event->attr.sample_id_all) | |
5150 | __perf_event__output_id_sample(handle, sample); | |
5151 | } | |
5152 | ||
3dab77fb | 5153 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5154 | struct perf_event *event, |
5155 | u64 enabled, u64 running) | |
3dab77fb | 5156 | { |
cdd6c482 | 5157 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5158 | u64 values[4]; |
5159 | int n = 0; | |
5160 | ||
b5e58793 | 5161 | values[n++] = perf_event_count(event); |
3dab77fb | 5162 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5163 | values[n++] = enabled + |
cdd6c482 | 5164 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5165 | } |
5166 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5167 | values[n++] = running + |
cdd6c482 | 5168 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5169 | } |
5170 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5171 | values[n++] = primary_event_id(event); |
3dab77fb | 5172 | |
76369139 | 5173 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5174 | } |
5175 | ||
5176 | /* | |
cdd6c482 | 5177 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5178 | */ |
5179 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5180 | struct perf_event *event, |
5181 | u64 enabled, u64 running) | |
3dab77fb | 5182 | { |
cdd6c482 IM |
5183 | struct perf_event *leader = event->group_leader, *sub; |
5184 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5185 | u64 values[5]; |
5186 | int n = 0; | |
5187 | ||
5188 | values[n++] = 1 + leader->nr_siblings; | |
5189 | ||
5190 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5191 | values[n++] = enabled; |
3dab77fb PZ |
5192 | |
5193 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5194 | values[n++] = running; |
3dab77fb | 5195 | |
cdd6c482 | 5196 | if (leader != event) |
3dab77fb PZ |
5197 | leader->pmu->read(leader); |
5198 | ||
b5e58793 | 5199 | values[n++] = perf_event_count(leader); |
3dab77fb | 5200 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5201 | values[n++] = primary_event_id(leader); |
3dab77fb | 5202 | |
76369139 | 5203 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5204 | |
65abc865 | 5205 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5206 | n = 0; |
5207 | ||
6f5ab001 JO |
5208 | if ((sub != event) && |
5209 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5210 | sub->pmu->read(sub); |
5211 | ||
b5e58793 | 5212 | values[n++] = perf_event_count(sub); |
3dab77fb | 5213 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5214 | values[n++] = primary_event_id(sub); |
3dab77fb | 5215 | |
76369139 | 5216 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5217 | } |
5218 | } | |
5219 | ||
eed01528 SE |
5220 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5221 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5222 | ||
3dab77fb | 5223 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5224 | struct perf_event *event) |
3dab77fb | 5225 | { |
e3f3541c | 5226 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5227 | u64 read_format = event->attr.read_format; |
5228 | ||
5229 | /* | |
5230 | * compute total_time_enabled, total_time_running | |
5231 | * based on snapshot values taken when the event | |
5232 | * was last scheduled in. | |
5233 | * | |
5234 | * we cannot simply called update_context_time() | |
5235 | * because of locking issue as we are called in | |
5236 | * NMI context | |
5237 | */ | |
c4794295 | 5238 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5239 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5240 | |
cdd6c482 | 5241 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5242 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5243 | else |
eed01528 | 5244 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5245 | } |
5246 | ||
5622f295 MM |
5247 | void perf_output_sample(struct perf_output_handle *handle, |
5248 | struct perf_event_header *header, | |
5249 | struct perf_sample_data *data, | |
cdd6c482 | 5250 | struct perf_event *event) |
5622f295 MM |
5251 | { |
5252 | u64 sample_type = data->type; | |
5253 | ||
5254 | perf_output_put(handle, *header); | |
5255 | ||
ff3d527c AH |
5256 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5257 | perf_output_put(handle, data->id); | |
5258 | ||
5622f295 MM |
5259 | if (sample_type & PERF_SAMPLE_IP) |
5260 | perf_output_put(handle, data->ip); | |
5261 | ||
5262 | if (sample_type & PERF_SAMPLE_TID) | |
5263 | perf_output_put(handle, data->tid_entry); | |
5264 | ||
5265 | if (sample_type & PERF_SAMPLE_TIME) | |
5266 | perf_output_put(handle, data->time); | |
5267 | ||
5268 | if (sample_type & PERF_SAMPLE_ADDR) | |
5269 | perf_output_put(handle, data->addr); | |
5270 | ||
5271 | if (sample_type & PERF_SAMPLE_ID) | |
5272 | perf_output_put(handle, data->id); | |
5273 | ||
5274 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5275 | perf_output_put(handle, data->stream_id); | |
5276 | ||
5277 | if (sample_type & PERF_SAMPLE_CPU) | |
5278 | perf_output_put(handle, data->cpu_entry); | |
5279 | ||
5280 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5281 | perf_output_put(handle, data->period); | |
5282 | ||
5283 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5284 | perf_output_read(handle, event); |
5622f295 MM |
5285 | |
5286 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5287 | if (data->callchain) { | |
5288 | int size = 1; | |
5289 | ||
5290 | if (data->callchain) | |
5291 | size += data->callchain->nr; | |
5292 | ||
5293 | size *= sizeof(u64); | |
5294 | ||
76369139 | 5295 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5296 | } else { |
5297 | u64 nr = 0; | |
5298 | perf_output_put(handle, nr); | |
5299 | } | |
5300 | } | |
5301 | ||
5302 | if (sample_type & PERF_SAMPLE_RAW) { | |
5303 | if (data->raw) { | |
fa128e6a AS |
5304 | u32 raw_size = data->raw->size; |
5305 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5306 | sizeof(u64)) - sizeof(u32); | |
5307 | u64 zero = 0; | |
5308 | ||
5309 | perf_output_put(handle, real_size); | |
5310 | __output_copy(handle, data->raw->data, raw_size); | |
5311 | if (real_size - raw_size) | |
5312 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5313 | } else { |
5314 | struct { | |
5315 | u32 size; | |
5316 | u32 data; | |
5317 | } raw = { | |
5318 | .size = sizeof(u32), | |
5319 | .data = 0, | |
5320 | }; | |
5321 | perf_output_put(handle, raw); | |
5322 | } | |
5323 | } | |
a7ac67ea | 5324 | |
bce38cd5 SE |
5325 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5326 | if (data->br_stack) { | |
5327 | size_t size; | |
5328 | ||
5329 | size = data->br_stack->nr | |
5330 | * sizeof(struct perf_branch_entry); | |
5331 | ||
5332 | perf_output_put(handle, data->br_stack->nr); | |
5333 | perf_output_copy(handle, data->br_stack->entries, size); | |
5334 | } else { | |
5335 | /* | |
5336 | * we always store at least the value of nr | |
5337 | */ | |
5338 | u64 nr = 0; | |
5339 | perf_output_put(handle, nr); | |
5340 | } | |
5341 | } | |
4018994f JO |
5342 | |
5343 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5344 | u64 abi = data->regs_user.abi; | |
5345 | ||
5346 | /* | |
5347 | * If there are no regs to dump, notice it through | |
5348 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5349 | */ | |
5350 | perf_output_put(handle, abi); | |
5351 | ||
5352 | if (abi) { | |
5353 | u64 mask = event->attr.sample_regs_user; | |
5354 | perf_output_sample_regs(handle, | |
5355 | data->regs_user.regs, | |
5356 | mask); | |
5357 | } | |
5358 | } | |
c5ebcedb | 5359 | |
a5cdd40c | 5360 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5361 | perf_output_sample_ustack(handle, |
5362 | data->stack_user_size, | |
5363 | data->regs_user.regs); | |
a5cdd40c | 5364 | } |
c3feedf2 AK |
5365 | |
5366 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5367 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5368 | |
5369 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5370 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5371 | |
fdfbbd07 AK |
5372 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5373 | perf_output_put(handle, data->txn); | |
5374 | ||
60e2364e SE |
5375 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5376 | u64 abi = data->regs_intr.abi; | |
5377 | /* | |
5378 | * If there are no regs to dump, notice it through | |
5379 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5380 | */ | |
5381 | perf_output_put(handle, abi); | |
5382 | ||
5383 | if (abi) { | |
5384 | u64 mask = event->attr.sample_regs_intr; | |
5385 | ||
5386 | perf_output_sample_regs(handle, | |
5387 | data->regs_intr.regs, | |
5388 | mask); | |
5389 | } | |
5390 | } | |
5391 | ||
a5cdd40c PZ |
5392 | if (!event->attr.watermark) { |
5393 | int wakeup_events = event->attr.wakeup_events; | |
5394 | ||
5395 | if (wakeup_events) { | |
5396 | struct ring_buffer *rb = handle->rb; | |
5397 | int events = local_inc_return(&rb->events); | |
5398 | ||
5399 | if (events >= wakeup_events) { | |
5400 | local_sub(wakeup_events, &rb->events); | |
5401 | local_inc(&rb->wakeup); | |
5402 | } | |
5403 | } | |
5404 | } | |
5622f295 MM |
5405 | } |
5406 | ||
5407 | void perf_prepare_sample(struct perf_event_header *header, | |
5408 | struct perf_sample_data *data, | |
cdd6c482 | 5409 | struct perf_event *event, |
5622f295 | 5410 | struct pt_regs *regs) |
7b732a75 | 5411 | { |
cdd6c482 | 5412 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5413 | |
cdd6c482 | 5414 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5415 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5416 | |
5417 | header->misc = 0; | |
5418 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5419 | |
c980d109 | 5420 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5421 | |
c320c7b7 | 5422 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5423 | data->ip = perf_instruction_pointer(regs); |
5424 | ||
b23f3325 | 5425 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5426 | int size = 1; |
394ee076 | 5427 | |
e6dab5ff | 5428 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5429 | |
5430 | if (data->callchain) | |
5431 | size += data->callchain->nr; | |
5432 | ||
5433 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5434 | } |
5435 | ||
3a43ce68 | 5436 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5437 | int size = sizeof(u32); |
5438 | ||
5439 | if (data->raw) | |
5440 | size += data->raw->size; | |
5441 | else | |
5442 | size += sizeof(u32); | |
5443 | ||
fa128e6a | 5444 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5445 | } |
bce38cd5 SE |
5446 | |
5447 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5448 | int size = sizeof(u64); /* nr */ | |
5449 | if (data->br_stack) { | |
5450 | size += data->br_stack->nr | |
5451 | * sizeof(struct perf_branch_entry); | |
5452 | } | |
5453 | header->size += size; | |
5454 | } | |
4018994f | 5455 | |
2565711f | 5456 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5457 | perf_sample_regs_user(&data->regs_user, regs, |
5458 | &data->regs_user_copy); | |
2565711f | 5459 | |
4018994f JO |
5460 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5461 | /* regs dump ABI info */ | |
5462 | int size = sizeof(u64); | |
5463 | ||
4018994f JO |
5464 | if (data->regs_user.regs) { |
5465 | u64 mask = event->attr.sample_regs_user; | |
5466 | size += hweight64(mask) * sizeof(u64); | |
5467 | } | |
5468 | ||
5469 | header->size += size; | |
5470 | } | |
c5ebcedb JO |
5471 | |
5472 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5473 | /* | |
5474 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5475 | * processed as the last one or have additional check added | |
5476 | * in case new sample type is added, because we could eat | |
5477 | * up the rest of the sample size. | |
5478 | */ | |
c5ebcedb JO |
5479 | u16 stack_size = event->attr.sample_stack_user; |
5480 | u16 size = sizeof(u64); | |
5481 | ||
c5ebcedb | 5482 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5483 | data->regs_user.regs); |
c5ebcedb JO |
5484 | |
5485 | /* | |
5486 | * If there is something to dump, add space for the dump | |
5487 | * itself and for the field that tells the dynamic size, | |
5488 | * which is how many have been actually dumped. | |
5489 | */ | |
5490 | if (stack_size) | |
5491 | size += sizeof(u64) + stack_size; | |
5492 | ||
5493 | data->stack_user_size = stack_size; | |
5494 | header->size += size; | |
5495 | } | |
60e2364e SE |
5496 | |
5497 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5498 | /* regs dump ABI info */ | |
5499 | int size = sizeof(u64); | |
5500 | ||
5501 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5502 | ||
5503 | if (data->regs_intr.regs) { | |
5504 | u64 mask = event->attr.sample_regs_intr; | |
5505 | ||
5506 | size += hweight64(mask) * sizeof(u64); | |
5507 | } | |
5508 | ||
5509 | header->size += size; | |
5510 | } | |
5622f295 | 5511 | } |
7f453c24 | 5512 | |
21509084 YZ |
5513 | void perf_event_output(struct perf_event *event, |
5514 | struct perf_sample_data *data, | |
5515 | struct pt_regs *regs) | |
5622f295 MM |
5516 | { |
5517 | struct perf_output_handle handle; | |
5518 | struct perf_event_header header; | |
689802b2 | 5519 | |
927c7a9e FW |
5520 | /* protect the callchain buffers */ |
5521 | rcu_read_lock(); | |
5522 | ||
cdd6c482 | 5523 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5524 | |
a7ac67ea | 5525 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5526 | goto exit; |
0322cd6e | 5527 | |
cdd6c482 | 5528 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5529 | |
8a057d84 | 5530 | perf_output_end(&handle); |
927c7a9e FW |
5531 | |
5532 | exit: | |
5533 | rcu_read_unlock(); | |
0322cd6e PZ |
5534 | } |
5535 | ||
38b200d6 | 5536 | /* |
cdd6c482 | 5537 | * read event_id |
38b200d6 PZ |
5538 | */ |
5539 | ||
5540 | struct perf_read_event { | |
5541 | struct perf_event_header header; | |
5542 | ||
5543 | u32 pid; | |
5544 | u32 tid; | |
38b200d6 PZ |
5545 | }; |
5546 | ||
5547 | static void | |
cdd6c482 | 5548 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5549 | struct task_struct *task) |
5550 | { | |
5551 | struct perf_output_handle handle; | |
c980d109 | 5552 | struct perf_sample_data sample; |
dfc65094 | 5553 | struct perf_read_event read_event = { |
38b200d6 | 5554 | .header = { |
cdd6c482 | 5555 | .type = PERF_RECORD_READ, |
38b200d6 | 5556 | .misc = 0, |
c320c7b7 | 5557 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5558 | }, |
cdd6c482 IM |
5559 | .pid = perf_event_pid(event, task), |
5560 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5561 | }; |
3dab77fb | 5562 | int ret; |
38b200d6 | 5563 | |
c980d109 | 5564 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5565 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5566 | if (ret) |
5567 | return; | |
5568 | ||
dfc65094 | 5569 | perf_output_put(&handle, read_event); |
cdd6c482 | 5570 | perf_output_read(&handle, event); |
c980d109 | 5571 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5572 | |
38b200d6 PZ |
5573 | perf_output_end(&handle); |
5574 | } | |
5575 | ||
52d857a8 JO |
5576 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5577 | ||
5578 | static void | |
5579 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5580 | perf_event_aux_output_cb output, |
5581 | void *data) | |
5582 | { | |
5583 | struct perf_event *event; | |
5584 | ||
5585 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5586 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5587 | continue; | |
5588 | if (!event_filter_match(event)) | |
5589 | continue; | |
67516844 | 5590 | output(event, data); |
52d857a8 JO |
5591 | } |
5592 | } | |
5593 | ||
4e93ad60 JO |
5594 | static void |
5595 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5596 | struct perf_event_context *task_ctx) | |
5597 | { | |
5598 | rcu_read_lock(); | |
5599 | preempt_disable(); | |
5600 | perf_event_aux_ctx(task_ctx, output, data); | |
5601 | preempt_enable(); | |
5602 | rcu_read_unlock(); | |
5603 | } | |
5604 | ||
52d857a8 | 5605 | static void |
67516844 | 5606 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5607 | struct perf_event_context *task_ctx) |
5608 | { | |
5609 | struct perf_cpu_context *cpuctx; | |
5610 | struct perf_event_context *ctx; | |
5611 | struct pmu *pmu; | |
5612 | int ctxn; | |
5613 | ||
4e93ad60 JO |
5614 | /* |
5615 | * If we have task_ctx != NULL we only notify | |
5616 | * the task context itself. The task_ctx is set | |
5617 | * only for EXIT events before releasing task | |
5618 | * context. | |
5619 | */ | |
5620 | if (task_ctx) { | |
5621 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5622 | return; | |
5623 | } | |
5624 | ||
52d857a8 JO |
5625 | rcu_read_lock(); |
5626 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5627 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5628 | if (cpuctx->unique_pmu != pmu) | |
5629 | goto next; | |
67516844 | 5630 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5631 | ctxn = pmu->task_ctx_nr; |
5632 | if (ctxn < 0) | |
5633 | goto next; | |
5634 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5635 | if (ctx) | |
67516844 | 5636 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5637 | next: |
5638 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5639 | } | |
52d857a8 JO |
5640 | rcu_read_unlock(); |
5641 | } | |
5642 | ||
60313ebe | 5643 | /* |
9f498cc5 PZ |
5644 | * task tracking -- fork/exit |
5645 | * | |
13d7a241 | 5646 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5647 | */ |
5648 | ||
9f498cc5 | 5649 | struct perf_task_event { |
3a80b4a3 | 5650 | struct task_struct *task; |
cdd6c482 | 5651 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5652 | |
5653 | struct { | |
5654 | struct perf_event_header header; | |
5655 | ||
5656 | u32 pid; | |
5657 | u32 ppid; | |
9f498cc5 PZ |
5658 | u32 tid; |
5659 | u32 ptid; | |
393b2ad8 | 5660 | u64 time; |
cdd6c482 | 5661 | } event_id; |
60313ebe PZ |
5662 | }; |
5663 | ||
67516844 JO |
5664 | static int perf_event_task_match(struct perf_event *event) |
5665 | { | |
13d7a241 SE |
5666 | return event->attr.comm || event->attr.mmap || |
5667 | event->attr.mmap2 || event->attr.mmap_data || | |
5668 | event->attr.task; | |
67516844 JO |
5669 | } |
5670 | ||
cdd6c482 | 5671 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5672 | void *data) |
60313ebe | 5673 | { |
52d857a8 | 5674 | struct perf_task_event *task_event = data; |
60313ebe | 5675 | struct perf_output_handle handle; |
c980d109 | 5676 | struct perf_sample_data sample; |
9f498cc5 | 5677 | struct task_struct *task = task_event->task; |
c980d109 | 5678 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5679 | |
67516844 JO |
5680 | if (!perf_event_task_match(event)) |
5681 | return; | |
5682 | ||
c980d109 | 5683 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5684 | |
c980d109 | 5685 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5686 | task_event->event_id.header.size); |
ef60777c | 5687 | if (ret) |
c980d109 | 5688 | goto out; |
60313ebe | 5689 | |
cdd6c482 IM |
5690 | task_event->event_id.pid = perf_event_pid(event, task); |
5691 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5692 | |
cdd6c482 IM |
5693 | task_event->event_id.tid = perf_event_tid(event, task); |
5694 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5695 | |
34f43927 PZ |
5696 | task_event->event_id.time = perf_event_clock(event); |
5697 | ||
cdd6c482 | 5698 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5699 | |
c980d109 ACM |
5700 | perf_event__output_id_sample(event, &handle, &sample); |
5701 | ||
60313ebe | 5702 | perf_output_end(&handle); |
c980d109 ACM |
5703 | out: |
5704 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5705 | } |
5706 | ||
cdd6c482 IM |
5707 | static void perf_event_task(struct task_struct *task, |
5708 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5709 | int new) |
60313ebe | 5710 | { |
9f498cc5 | 5711 | struct perf_task_event task_event; |
60313ebe | 5712 | |
cdd6c482 IM |
5713 | if (!atomic_read(&nr_comm_events) && |
5714 | !atomic_read(&nr_mmap_events) && | |
5715 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5716 | return; |
5717 | ||
9f498cc5 | 5718 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5719 | .task = task, |
5720 | .task_ctx = task_ctx, | |
cdd6c482 | 5721 | .event_id = { |
60313ebe | 5722 | .header = { |
cdd6c482 | 5723 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5724 | .misc = 0, |
cdd6c482 | 5725 | .size = sizeof(task_event.event_id), |
60313ebe | 5726 | }, |
573402db PZ |
5727 | /* .pid */ |
5728 | /* .ppid */ | |
9f498cc5 PZ |
5729 | /* .tid */ |
5730 | /* .ptid */ | |
34f43927 | 5731 | /* .time */ |
60313ebe PZ |
5732 | }, |
5733 | }; | |
5734 | ||
67516844 | 5735 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5736 | &task_event, |
5737 | task_ctx); | |
9f498cc5 PZ |
5738 | } |
5739 | ||
cdd6c482 | 5740 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5741 | { |
cdd6c482 | 5742 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5743 | } |
5744 | ||
8d1b2d93 PZ |
5745 | /* |
5746 | * comm tracking | |
5747 | */ | |
5748 | ||
5749 | struct perf_comm_event { | |
22a4f650 IM |
5750 | struct task_struct *task; |
5751 | char *comm; | |
8d1b2d93 PZ |
5752 | int comm_size; |
5753 | ||
5754 | struct { | |
5755 | struct perf_event_header header; | |
5756 | ||
5757 | u32 pid; | |
5758 | u32 tid; | |
cdd6c482 | 5759 | } event_id; |
8d1b2d93 PZ |
5760 | }; |
5761 | ||
67516844 JO |
5762 | static int perf_event_comm_match(struct perf_event *event) |
5763 | { | |
5764 | return event->attr.comm; | |
5765 | } | |
5766 | ||
cdd6c482 | 5767 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5768 | void *data) |
8d1b2d93 | 5769 | { |
52d857a8 | 5770 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5771 | struct perf_output_handle handle; |
c980d109 | 5772 | struct perf_sample_data sample; |
cdd6c482 | 5773 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5774 | int ret; |
5775 | ||
67516844 JO |
5776 | if (!perf_event_comm_match(event)) |
5777 | return; | |
5778 | ||
c980d109 ACM |
5779 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5780 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5781 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5782 | |
5783 | if (ret) | |
c980d109 | 5784 | goto out; |
8d1b2d93 | 5785 | |
cdd6c482 IM |
5786 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5787 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5788 | |
cdd6c482 | 5789 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5790 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5791 | comm_event->comm_size); |
c980d109 ACM |
5792 | |
5793 | perf_event__output_id_sample(event, &handle, &sample); | |
5794 | ||
8d1b2d93 | 5795 | perf_output_end(&handle); |
c980d109 ACM |
5796 | out: |
5797 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5798 | } |
5799 | ||
cdd6c482 | 5800 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5801 | { |
413ee3b4 | 5802 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5803 | unsigned int size; |
8d1b2d93 | 5804 | |
413ee3b4 | 5805 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5806 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5807 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5808 | |
5809 | comm_event->comm = comm; | |
5810 | comm_event->comm_size = size; | |
5811 | ||
cdd6c482 | 5812 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5813 | |
67516844 | 5814 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5815 | comm_event, |
5816 | NULL); | |
8d1b2d93 PZ |
5817 | } |
5818 | ||
82b89778 | 5819 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5820 | { |
9ee318a7 PZ |
5821 | struct perf_comm_event comm_event; |
5822 | ||
cdd6c482 | 5823 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5824 | return; |
a63eaf34 | 5825 | |
9ee318a7 | 5826 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5827 | .task = task, |
573402db PZ |
5828 | /* .comm */ |
5829 | /* .comm_size */ | |
cdd6c482 | 5830 | .event_id = { |
573402db | 5831 | .header = { |
cdd6c482 | 5832 | .type = PERF_RECORD_COMM, |
82b89778 | 5833 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5834 | /* .size */ |
5835 | }, | |
5836 | /* .pid */ | |
5837 | /* .tid */ | |
8d1b2d93 PZ |
5838 | }, |
5839 | }; | |
5840 | ||
cdd6c482 | 5841 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5842 | } |
5843 | ||
0a4a9391 PZ |
5844 | /* |
5845 | * mmap tracking | |
5846 | */ | |
5847 | ||
5848 | struct perf_mmap_event { | |
089dd79d PZ |
5849 | struct vm_area_struct *vma; |
5850 | ||
5851 | const char *file_name; | |
5852 | int file_size; | |
13d7a241 SE |
5853 | int maj, min; |
5854 | u64 ino; | |
5855 | u64 ino_generation; | |
f972eb63 | 5856 | u32 prot, flags; |
0a4a9391 PZ |
5857 | |
5858 | struct { | |
5859 | struct perf_event_header header; | |
5860 | ||
5861 | u32 pid; | |
5862 | u32 tid; | |
5863 | u64 start; | |
5864 | u64 len; | |
5865 | u64 pgoff; | |
cdd6c482 | 5866 | } event_id; |
0a4a9391 PZ |
5867 | }; |
5868 | ||
67516844 JO |
5869 | static int perf_event_mmap_match(struct perf_event *event, |
5870 | void *data) | |
5871 | { | |
5872 | struct perf_mmap_event *mmap_event = data; | |
5873 | struct vm_area_struct *vma = mmap_event->vma; | |
5874 | int executable = vma->vm_flags & VM_EXEC; | |
5875 | ||
5876 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5877 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5878 | } |
5879 | ||
cdd6c482 | 5880 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5881 | void *data) |
0a4a9391 | 5882 | { |
52d857a8 | 5883 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5884 | struct perf_output_handle handle; |
c980d109 | 5885 | struct perf_sample_data sample; |
cdd6c482 | 5886 | int size = mmap_event->event_id.header.size; |
c980d109 | 5887 | int ret; |
0a4a9391 | 5888 | |
67516844 JO |
5889 | if (!perf_event_mmap_match(event, data)) |
5890 | return; | |
5891 | ||
13d7a241 SE |
5892 | if (event->attr.mmap2) { |
5893 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5894 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5895 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5896 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5897 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5898 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5899 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5900 | } |
5901 | ||
c980d109 ACM |
5902 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5903 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5904 | mmap_event->event_id.header.size); |
0a4a9391 | 5905 | if (ret) |
c980d109 | 5906 | goto out; |
0a4a9391 | 5907 | |
cdd6c482 IM |
5908 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5909 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5910 | |
cdd6c482 | 5911 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5912 | |
5913 | if (event->attr.mmap2) { | |
5914 | perf_output_put(&handle, mmap_event->maj); | |
5915 | perf_output_put(&handle, mmap_event->min); | |
5916 | perf_output_put(&handle, mmap_event->ino); | |
5917 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5918 | perf_output_put(&handle, mmap_event->prot); |
5919 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5920 | } |
5921 | ||
76369139 | 5922 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5923 | mmap_event->file_size); |
c980d109 ACM |
5924 | |
5925 | perf_event__output_id_sample(event, &handle, &sample); | |
5926 | ||
78d613eb | 5927 | perf_output_end(&handle); |
c980d109 ACM |
5928 | out: |
5929 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5930 | } |
5931 | ||
cdd6c482 | 5932 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5933 | { |
089dd79d PZ |
5934 | struct vm_area_struct *vma = mmap_event->vma; |
5935 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5936 | int maj = 0, min = 0; |
5937 | u64 ino = 0, gen = 0; | |
f972eb63 | 5938 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5939 | unsigned int size; |
5940 | char tmp[16]; | |
5941 | char *buf = NULL; | |
2c42cfbf | 5942 | char *name; |
413ee3b4 | 5943 | |
0a4a9391 | 5944 | if (file) { |
13d7a241 SE |
5945 | struct inode *inode; |
5946 | dev_t dev; | |
3ea2f2b9 | 5947 | |
2c42cfbf | 5948 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5949 | if (!buf) { |
c7e548b4 ON |
5950 | name = "//enomem"; |
5951 | goto cpy_name; | |
0a4a9391 | 5952 | } |
413ee3b4 | 5953 | /* |
3ea2f2b9 | 5954 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5955 | * need to add enough zero bytes after the string to handle |
5956 | * the 64bit alignment we do later. | |
5957 | */ | |
9bf39ab2 | 5958 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5959 | if (IS_ERR(name)) { |
c7e548b4 ON |
5960 | name = "//toolong"; |
5961 | goto cpy_name; | |
0a4a9391 | 5962 | } |
13d7a241 SE |
5963 | inode = file_inode(vma->vm_file); |
5964 | dev = inode->i_sb->s_dev; | |
5965 | ino = inode->i_ino; | |
5966 | gen = inode->i_generation; | |
5967 | maj = MAJOR(dev); | |
5968 | min = MINOR(dev); | |
f972eb63 PZ |
5969 | |
5970 | if (vma->vm_flags & VM_READ) | |
5971 | prot |= PROT_READ; | |
5972 | if (vma->vm_flags & VM_WRITE) | |
5973 | prot |= PROT_WRITE; | |
5974 | if (vma->vm_flags & VM_EXEC) | |
5975 | prot |= PROT_EXEC; | |
5976 | ||
5977 | if (vma->vm_flags & VM_MAYSHARE) | |
5978 | flags = MAP_SHARED; | |
5979 | else | |
5980 | flags = MAP_PRIVATE; | |
5981 | ||
5982 | if (vma->vm_flags & VM_DENYWRITE) | |
5983 | flags |= MAP_DENYWRITE; | |
5984 | if (vma->vm_flags & VM_MAYEXEC) | |
5985 | flags |= MAP_EXECUTABLE; | |
5986 | if (vma->vm_flags & VM_LOCKED) | |
5987 | flags |= MAP_LOCKED; | |
5988 | if (vma->vm_flags & VM_HUGETLB) | |
5989 | flags |= MAP_HUGETLB; | |
5990 | ||
c7e548b4 | 5991 | goto got_name; |
0a4a9391 | 5992 | } else { |
fbe26abe JO |
5993 | if (vma->vm_ops && vma->vm_ops->name) { |
5994 | name = (char *) vma->vm_ops->name(vma); | |
5995 | if (name) | |
5996 | goto cpy_name; | |
5997 | } | |
5998 | ||
2c42cfbf | 5999 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6000 | if (name) |
6001 | goto cpy_name; | |
089dd79d | 6002 | |
32c5fb7e | 6003 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6004 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6005 | name = "[heap]"; |
6006 | goto cpy_name; | |
32c5fb7e ON |
6007 | } |
6008 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6009 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6010 | name = "[stack]"; |
6011 | goto cpy_name; | |
089dd79d PZ |
6012 | } |
6013 | ||
c7e548b4 ON |
6014 | name = "//anon"; |
6015 | goto cpy_name; | |
0a4a9391 PZ |
6016 | } |
6017 | ||
c7e548b4 ON |
6018 | cpy_name: |
6019 | strlcpy(tmp, name, sizeof(tmp)); | |
6020 | name = tmp; | |
0a4a9391 | 6021 | got_name: |
2c42cfbf PZ |
6022 | /* |
6023 | * Since our buffer works in 8 byte units we need to align our string | |
6024 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6025 | * zero'd out to avoid leaking random bits to userspace. | |
6026 | */ | |
6027 | size = strlen(name)+1; | |
6028 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6029 | name[size++] = '\0'; | |
0a4a9391 PZ |
6030 | |
6031 | mmap_event->file_name = name; | |
6032 | mmap_event->file_size = size; | |
13d7a241 SE |
6033 | mmap_event->maj = maj; |
6034 | mmap_event->min = min; | |
6035 | mmap_event->ino = ino; | |
6036 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6037 | mmap_event->prot = prot; |
6038 | mmap_event->flags = flags; | |
0a4a9391 | 6039 | |
2fe85427 SE |
6040 | if (!(vma->vm_flags & VM_EXEC)) |
6041 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6042 | ||
cdd6c482 | 6043 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6044 | |
67516844 | 6045 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6046 | mmap_event, |
6047 | NULL); | |
665c2142 | 6048 | |
0a4a9391 PZ |
6049 | kfree(buf); |
6050 | } | |
6051 | ||
3af9e859 | 6052 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6053 | { |
9ee318a7 PZ |
6054 | struct perf_mmap_event mmap_event; |
6055 | ||
cdd6c482 | 6056 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6057 | return; |
6058 | ||
6059 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6060 | .vma = vma, |
573402db PZ |
6061 | /* .file_name */ |
6062 | /* .file_size */ | |
cdd6c482 | 6063 | .event_id = { |
573402db | 6064 | .header = { |
cdd6c482 | 6065 | .type = PERF_RECORD_MMAP, |
39447b38 | 6066 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6067 | /* .size */ |
6068 | }, | |
6069 | /* .pid */ | |
6070 | /* .tid */ | |
089dd79d PZ |
6071 | .start = vma->vm_start, |
6072 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6073 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6074 | }, |
13d7a241 SE |
6075 | /* .maj (attr_mmap2 only) */ |
6076 | /* .min (attr_mmap2 only) */ | |
6077 | /* .ino (attr_mmap2 only) */ | |
6078 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6079 | /* .prot (attr_mmap2 only) */ |
6080 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6081 | }; |
6082 | ||
cdd6c482 | 6083 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6084 | } |
6085 | ||
68db7e98 AS |
6086 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6087 | unsigned long size, u64 flags) | |
6088 | { | |
6089 | struct perf_output_handle handle; | |
6090 | struct perf_sample_data sample; | |
6091 | struct perf_aux_event { | |
6092 | struct perf_event_header header; | |
6093 | u64 offset; | |
6094 | u64 size; | |
6095 | u64 flags; | |
6096 | } rec = { | |
6097 | .header = { | |
6098 | .type = PERF_RECORD_AUX, | |
6099 | .misc = 0, | |
6100 | .size = sizeof(rec), | |
6101 | }, | |
6102 | .offset = head, | |
6103 | .size = size, | |
6104 | .flags = flags, | |
6105 | }; | |
6106 | int ret; | |
6107 | ||
6108 | perf_event_header__init_id(&rec.header, &sample, event); | |
6109 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6110 | ||
6111 | if (ret) | |
6112 | return; | |
6113 | ||
6114 | perf_output_put(&handle, rec); | |
6115 | perf_event__output_id_sample(event, &handle, &sample); | |
6116 | ||
6117 | perf_output_end(&handle); | |
6118 | } | |
6119 | ||
f38b0dbb KL |
6120 | /* |
6121 | * Lost/dropped samples logging | |
6122 | */ | |
6123 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6124 | { | |
6125 | struct perf_output_handle handle; | |
6126 | struct perf_sample_data sample; | |
6127 | int ret; | |
6128 | ||
6129 | struct { | |
6130 | struct perf_event_header header; | |
6131 | u64 lost; | |
6132 | } lost_samples_event = { | |
6133 | .header = { | |
6134 | .type = PERF_RECORD_LOST_SAMPLES, | |
6135 | .misc = 0, | |
6136 | .size = sizeof(lost_samples_event), | |
6137 | }, | |
6138 | .lost = lost, | |
6139 | }; | |
6140 | ||
6141 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6142 | ||
6143 | ret = perf_output_begin(&handle, event, | |
6144 | lost_samples_event.header.size); | |
6145 | if (ret) | |
6146 | return; | |
6147 | ||
6148 | perf_output_put(&handle, lost_samples_event); | |
6149 | perf_event__output_id_sample(event, &handle, &sample); | |
6150 | perf_output_end(&handle); | |
6151 | } | |
6152 | ||
45ac1403 AH |
6153 | /* |
6154 | * context_switch tracking | |
6155 | */ | |
6156 | ||
6157 | struct perf_switch_event { | |
6158 | struct task_struct *task; | |
6159 | struct task_struct *next_prev; | |
6160 | ||
6161 | struct { | |
6162 | struct perf_event_header header; | |
6163 | u32 next_prev_pid; | |
6164 | u32 next_prev_tid; | |
6165 | } event_id; | |
6166 | }; | |
6167 | ||
6168 | static int perf_event_switch_match(struct perf_event *event) | |
6169 | { | |
6170 | return event->attr.context_switch; | |
6171 | } | |
6172 | ||
6173 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6174 | { | |
6175 | struct perf_switch_event *se = data; | |
6176 | struct perf_output_handle handle; | |
6177 | struct perf_sample_data sample; | |
6178 | int ret; | |
6179 | ||
6180 | if (!perf_event_switch_match(event)) | |
6181 | return; | |
6182 | ||
6183 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6184 | if (event->ctx->task) { | |
6185 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6186 | se->event_id.header.size = sizeof(se->event_id.header); | |
6187 | } else { | |
6188 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6189 | se->event_id.header.size = sizeof(se->event_id); | |
6190 | se->event_id.next_prev_pid = | |
6191 | perf_event_pid(event, se->next_prev); | |
6192 | se->event_id.next_prev_tid = | |
6193 | perf_event_tid(event, se->next_prev); | |
6194 | } | |
6195 | ||
6196 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6197 | ||
6198 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6199 | if (ret) | |
6200 | return; | |
6201 | ||
6202 | if (event->ctx->task) | |
6203 | perf_output_put(&handle, se->event_id.header); | |
6204 | else | |
6205 | perf_output_put(&handle, se->event_id); | |
6206 | ||
6207 | perf_event__output_id_sample(event, &handle, &sample); | |
6208 | ||
6209 | perf_output_end(&handle); | |
6210 | } | |
6211 | ||
6212 | static void perf_event_switch(struct task_struct *task, | |
6213 | struct task_struct *next_prev, bool sched_in) | |
6214 | { | |
6215 | struct perf_switch_event switch_event; | |
6216 | ||
6217 | /* N.B. caller checks nr_switch_events != 0 */ | |
6218 | ||
6219 | switch_event = (struct perf_switch_event){ | |
6220 | .task = task, | |
6221 | .next_prev = next_prev, | |
6222 | .event_id = { | |
6223 | .header = { | |
6224 | /* .type */ | |
6225 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6226 | /* .size */ | |
6227 | }, | |
6228 | /* .next_prev_pid */ | |
6229 | /* .next_prev_tid */ | |
6230 | }, | |
6231 | }; | |
6232 | ||
6233 | perf_event_aux(perf_event_switch_output, | |
6234 | &switch_event, | |
6235 | NULL); | |
6236 | } | |
6237 | ||
a78ac325 PZ |
6238 | /* |
6239 | * IRQ throttle logging | |
6240 | */ | |
6241 | ||
cdd6c482 | 6242 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6243 | { |
6244 | struct perf_output_handle handle; | |
c980d109 | 6245 | struct perf_sample_data sample; |
a78ac325 PZ |
6246 | int ret; |
6247 | ||
6248 | struct { | |
6249 | struct perf_event_header header; | |
6250 | u64 time; | |
cca3f454 | 6251 | u64 id; |
7f453c24 | 6252 | u64 stream_id; |
a78ac325 PZ |
6253 | } throttle_event = { |
6254 | .header = { | |
cdd6c482 | 6255 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6256 | .misc = 0, |
6257 | .size = sizeof(throttle_event), | |
6258 | }, | |
34f43927 | 6259 | .time = perf_event_clock(event), |
cdd6c482 IM |
6260 | .id = primary_event_id(event), |
6261 | .stream_id = event->id, | |
a78ac325 PZ |
6262 | }; |
6263 | ||
966ee4d6 | 6264 | if (enable) |
cdd6c482 | 6265 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6266 | |
c980d109 ACM |
6267 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6268 | ||
6269 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6270 | throttle_event.header.size); |
a78ac325 PZ |
6271 | if (ret) |
6272 | return; | |
6273 | ||
6274 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6275 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6276 | perf_output_end(&handle); |
6277 | } | |
6278 | ||
ec0d7729 AS |
6279 | static void perf_log_itrace_start(struct perf_event *event) |
6280 | { | |
6281 | struct perf_output_handle handle; | |
6282 | struct perf_sample_data sample; | |
6283 | struct perf_aux_event { | |
6284 | struct perf_event_header header; | |
6285 | u32 pid; | |
6286 | u32 tid; | |
6287 | } rec; | |
6288 | int ret; | |
6289 | ||
6290 | if (event->parent) | |
6291 | event = event->parent; | |
6292 | ||
6293 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6294 | event->hw.itrace_started) | |
6295 | return; | |
6296 | ||
ec0d7729 AS |
6297 | rec.header.type = PERF_RECORD_ITRACE_START; |
6298 | rec.header.misc = 0; | |
6299 | rec.header.size = sizeof(rec); | |
6300 | rec.pid = perf_event_pid(event, current); | |
6301 | rec.tid = perf_event_tid(event, current); | |
6302 | ||
6303 | perf_event_header__init_id(&rec.header, &sample, event); | |
6304 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6305 | ||
6306 | if (ret) | |
6307 | return; | |
6308 | ||
6309 | perf_output_put(&handle, rec); | |
6310 | perf_event__output_id_sample(event, &handle, &sample); | |
6311 | ||
6312 | perf_output_end(&handle); | |
6313 | } | |
6314 | ||
f6c7d5fe | 6315 | /* |
cdd6c482 | 6316 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6317 | */ |
6318 | ||
a8b0ca17 | 6319 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6320 | int throttle, struct perf_sample_data *data, |
6321 | struct pt_regs *regs) | |
f6c7d5fe | 6322 | { |
cdd6c482 IM |
6323 | int events = atomic_read(&event->event_limit); |
6324 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6325 | u64 seq; |
79f14641 PZ |
6326 | int ret = 0; |
6327 | ||
96398826 PZ |
6328 | /* |
6329 | * Non-sampling counters might still use the PMI to fold short | |
6330 | * hardware counters, ignore those. | |
6331 | */ | |
6332 | if (unlikely(!is_sampling_event(event))) | |
6333 | return 0; | |
6334 | ||
e050e3f0 SE |
6335 | seq = __this_cpu_read(perf_throttled_seq); |
6336 | if (seq != hwc->interrupts_seq) { | |
6337 | hwc->interrupts_seq = seq; | |
6338 | hwc->interrupts = 1; | |
6339 | } else { | |
6340 | hwc->interrupts++; | |
6341 | if (unlikely(throttle | |
6342 | && hwc->interrupts >= max_samples_per_tick)) { | |
6343 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6344 | hwc->interrupts = MAX_INTERRUPTS; |
6345 | perf_log_throttle(event, 0); | |
d84153d6 | 6346 | tick_nohz_full_kick(); |
a78ac325 PZ |
6347 | ret = 1; |
6348 | } | |
e050e3f0 | 6349 | } |
60db5e09 | 6350 | |
cdd6c482 | 6351 | if (event->attr.freq) { |
def0a9b2 | 6352 | u64 now = perf_clock(); |
abd50713 | 6353 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6354 | |
abd50713 | 6355 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6356 | |
abd50713 | 6357 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6358 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6359 | } |
6360 | ||
2023b359 PZ |
6361 | /* |
6362 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6363 | * events |
2023b359 PZ |
6364 | */ |
6365 | ||
cdd6c482 IM |
6366 | event->pending_kill = POLL_IN; |
6367 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6368 | ret = 1; |
cdd6c482 | 6369 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6370 | event->pending_disable = 1; |
6371 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6372 | } |
6373 | ||
453f19ee | 6374 | if (event->overflow_handler) |
a8b0ca17 | 6375 | event->overflow_handler(event, data, regs); |
453f19ee | 6376 | else |
a8b0ca17 | 6377 | perf_event_output(event, data, regs); |
453f19ee | 6378 | |
fed66e2c | 6379 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6380 | event->pending_wakeup = 1; |
6381 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6382 | } |
6383 | ||
79f14641 | 6384 | return ret; |
f6c7d5fe PZ |
6385 | } |
6386 | ||
a8b0ca17 | 6387 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6388 | struct perf_sample_data *data, |
6389 | struct pt_regs *regs) | |
850bc73f | 6390 | { |
a8b0ca17 | 6391 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6392 | } |
6393 | ||
15dbf27c | 6394 | /* |
cdd6c482 | 6395 | * Generic software event infrastructure |
15dbf27c PZ |
6396 | */ |
6397 | ||
b28ab83c PZ |
6398 | struct swevent_htable { |
6399 | struct swevent_hlist *swevent_hlist; | |
6400 | struct mutex hlist_mutex; | |
6401 | int hlist_refcount; | |
6402 | ||
6403 | /* Recursion avoidance in each contexts */ | |
6404 | int recursion[PERF_NR_CONTEXTS]; | |
6405 | }; | |
6406 | ||
6407 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6408 | ||
7b4b6658 | 6409 | /* |
cdd6c482 IM |
6410 | * We directly increment event->count and keep a second value in |
6411 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6412 | * is kept in the range [-sample_period, 0] so that we can use the |
6413 | * sign as trigger. | |
6414 | */ | |
6415 | ||
ab573844 | 6416 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6417 | { |
cdd6c482 | 6418 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6419 | u64 period = hwc->last_period; |
6420 | u64 nr, offset; | |
6421 | s64 old, val; | |
6422 | ||
6423 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6424 | |
6425 | again: | |
e7850595 | 6426 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6427 | if (val < 0) |
6428 | return 0; | |
15dbf27c | 6429 | |
7b4b6658 PZ |
6430 | nr = div64_u64(period + val, period); |
6431 | offset = nr * period; | |
6432 | val -= offset; | |
e7850595 | 6433 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6434 | goto again; |
15dbf27c | 6435 | |
7b4b6658 | 6436 | return nr; |
15dbf27c PZ |
6437 | } |
6438 | ||
0cff784a | 6439 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6440 | struct perf_sample_data *data, |
5622f295 | 6441 | struct pt_regs *regs) |
15dbf27c | 6442 | { |
cdd6c482 | 6443 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6444 | int throttle = 0; |
15dbf27c | 6445 | |
0cff784a PZ |
6446 | if (!overflow) |
6447 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6448 | |
7b4b6658 PZ |
6449 | if (hwc->interrupts == MAX_INTERRUPTS) |
6450 | return; | |
15dbf27c | 6451 | |
7b4b6658 | 6452 | for (; overflow; overflow--) { |
a8b0ca17 | 6453 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6454 | data, regs)) { |
7b4b6658 PZ |
6455 | /* |
6456 | * We inhibit the overflow from happening when | |
6457 | * hwc->interrupts == MAX_INTERRUPTS. | |
6458 | */ | |
6459 | break; | |
6460 | } | |
cf450a73 | 6461 | throttle = 1; |
7b4b6658 | 6462 | } |
15dbf27c PZ |
6463 | } |
6464 | ||
a4eaf7f1 | 6465 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6466 | struct perf_sample_data *data, |
5622f295 | 6467 | struct pt_regs *regs) |
7b4b6658 | 6468 | { |
cdd6c482 | 6469 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6470 | |
e7850595 | 6471 | local64_add(nr, &event->count); |
d6d020e9 | 6472 | |
0cff784a PZ |
6473 | if (!regs) |
6474 | return; | |
6475 | ||
6c7e550f | 6476 | if (!is_sampling_event(event)) |
7b4b6658 | 6477 | return; |
d6d020e9 | 6478 | |
5d81e5cf AV |
6479 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6480 | data->period = nr; | |
6481 | return perf_swevent_overflow(event, 1, data, regs); | |
6482 | } else | |
6483 | data->period = event->hw.last_period; | |
6484 | ||
0cff784a | 6485 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6486 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6487 | |
e7850595 | 6488 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6489 | return; |
df1a132b | 6490 | |
a8b0ca17 | 6491 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6492 | } |
6493 | ||
f5ffe02e FW |
6494 | static int perf_exclude_event(struct perf_event *event, |
6495 | struct pt_regs *regs) | |
6496 | { | |
a4eaf7f1 | 6497 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6498 | return 1; |
a4eaf7f1 | 6499 | |
f5ffe02e FW |
6500 | if (regs) { |
6501 | if (event->attr.exclude_user && user_mode(regs)) | |
6502 | return 1; | |
6503 | ||
6504 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6505 | return 1; | |
6506 | } | |
6507 | ||
6508 | return 0; | |
6509 | } | |
6510 | ||
cdd6c482 | 6511 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6512 | enum perf_type_id type, |
6fb2915d LZ |
6513 | u32 event_id, |
6514 | struct perf_sample_data *data, | |
6515 | struct pt_regs *regs) | |
15dbf27c | 6516 | { |
cdd6c482 | 6517 | if (event->attr.type != type) |
a21ca2ca | 6518 | return 0; |
f5ffe02e | 6519 | |
cdd6c482 | 6520 | if (event->attr.config != event_id) |
15dbf27c PZ |
6521 | return 0; |
6522 | ||
f5ffe02e FW |
6523 | if (perf_exclude_event(event, regs)) |
6524 | return 0; | |
15dbf27c PZ |
6525 | |
6526 | return 1; | |
6527 | } | |
6528 | ||
76e1d904 FW |
6529 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6530 | { | |
6531 | u64 val = event_id | (type << 32); | |
6532 | ||
6533 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6534 | } | |
6535 | ||
49f135ed FW |
6536 | static inline struct hlist_head * |
6537 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6538 | { |
49f135ed FW |
6539 | u64 hash = swevent_hash(type, event_id); |
6540 | ||
6541 | return &hlist->heads[hash]; | |
6542 | } | |
76e1d904 | 6543 | |
49f135ed FW |
6544 | /* For the read side: events when they trigger */ |
6545 | static inline struct hlist_head * | |
b28ab83c | 6546 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6547 | { |
6548 | struct swevent_hlist *hlist; | |
76e1d904 | 6549 | |
b28ab83c | 6550 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6551 | if (!hlist) |
6552 | return NULL; | |
6553 | ||
49f135ed FW |
6554 | return __find_swevent_head(hlist, type, event_id); |
6555 | } | |
6556 | ||
6557 | /* For the event head insertion and removal in the hlist */ | |
6558 | static inline struct hlist_head * | |
b28ab83c | 6559 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6560 | { |
6561 | struct swevent_hlist *hlist; | |
6562 | u32 event_id = event->attr.config; | |
6563 | u64 type = event->attr.type; | |
6564 | ||
6565 | /* | |
6566 | * Event scheduling is always serialized against hlist allocation | |
6567 | * and release. Which makes the protected version suitable here. | |
6568 | * The context lock guarantees that. | |
6569 | */ | |
b28ab83c | 6570 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6571 | lockdep_is_held(&event->ctx->lock)); |
6572 | if (!hlist) | |
6573 | return NULL; | |
6574 | ||
6575 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6576 | } |
6577 | ||
6578 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6579 | u64 nr, |
76e1d904 FW |
6580 | struct perf_sample_data *data, |
6581 | struct pt_regs *regs) | |
15dbf27c | 6582 | { |
4a32fea9 | 6583 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6584 | struct perf_event *event; |
76e1d904 | 6585 | struct hlist_head *head; |
15dbf27c | 6586 | |
76e1d904 | 6587 | rcu_read_lock(); |
b28ab83c | 6588 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6589 | if (!head) |
6590 | goto end; | |
6591 | ||
b67bfe0d | 6592 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6593 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6594 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6595 | } |
76e1d904 FW |
6596 | end: |
6597 | rcu_read_unlock(); | |
15dbf27c PZ |
6598 | } |
6599 | ||
86038c5e PZI |
6600 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6601 | ||
4ed7c92d | 6602 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6603 | { |
4a32fea9 | 6604 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6605 | |
b28ab83c | 6606 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6607 | } |
645e8cc0 | 6608 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6609 | |
fa9f90be | 6610 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6611 | { |
4a32fea9 | 6612 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6613 | |
b28ab83c | 6614 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6615 | } |
15dbf27c | 6616 | |
86038c5e | 6617 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6618 | { |
a4234bfc | 6619 | struct perf_sample_data data; |
4ed7c92d | 6620 | |
86038c5e | 6621 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6622 | return; |
a4234bfc | 6623 | |
fd0d000b | 6624 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6625 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6626 | } |
6627 | ||
6628 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6629 | { | |
6630 | int rctx; | |
6631 | ||
6632 | preempt_disable_notrace(); | |
6633 | rctx = perf_swevent_get_recursion_context(); | |
6634 | if (unlikely(rctx < 0)) | |
6635 | goto fail; | |
6636 | ||
6637 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6638 | |
6639 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6640 | fail: |
1c024eca | 6641 | preempt_enable_notrace(); |
b8e83514 PZ |
6642 | } |
6643 | ||
cdd6c482 | 6644 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6645 | { |
15dbf27c PZ |
6646 | } |
6647 | ||
a4eaf7f1 | 6648 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6649 | { |
4a32fea9 | 6650 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6651 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6652 | struct hlist_head *head; |
6653 | ||
6c7e550f | 6654 | if (is_sampling_event(event)) { |
7b4b6658 | 6655 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6656 | perf_swevent_set_period(event); |
7b4b6658 | 6657 | } |
76e1d904 | 6658 | |
a4eaf7f1 PZ |
6659 | hwc->state = !(flags & PERF_EF_START); |
6660 | ||
b28ab83c | 6661 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6662 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6663 | return -EINVAL; |
6664 | ||
6665 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6666 | perf_event_update_userpage(event); |
76e1d904 | 6667 | |
15dbf27c PZ |
6668 | return 0; |
6669 | } | |
6670 | ||
a4eaf7f1 | 6671 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6672 | { |
76e1d904 | 6673 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6674 | } |
6675 | ||
a4eaf7f1 | 6676 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6677 | { |
a4eaf7f1 | 6678 | event->hw.state = 0; |
d6d020e9 | 6679 | } |
aa9c4c0f | 6680 | |
a4eaf7f1 | 6681 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6682 | { |
a4eaf7f1 | 6683 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6684 | } |
6685 | ||
49f135ed FW |
6686 | /* Deref the hlist from the update side */ |
6687 | static inline struct swevent_hlist * | |
b28ab83c | 6688 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6689 | { |
b28ab83c PZ |
6690 | return rcu_dereference_protected(swhash->swevent_hlist, |
6691 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6692 | } |
6693 | ||
b28ab83c | 6694 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6695 | { |
b28ab83c | 6696 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6697 | |
49f135ed | 6698 | if (!hlist) |
76e1d904 FW |
6699 | return; |
6700 | ||
70691d4a | 6701 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6702 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6703 | } |
6704 | ||
6705 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6706 | { | |
b28ab83c | 6707 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6708 | |
b28ab83c | 6709 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6710 | |
b28ab83c PZ |
6711 | if (!--swhash->hlist_refcount) |
6712 | swevent_hlist_release(swhash); | |
76e1d904 | 6713 | |
b28ab83c | 6714 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6715 | } |
6716 | ||
6717 | static void swevent_hlist_put(struct perf_event *event) | |
6718 | { | |
6719 | int cpu; | |
6720 | ||
76e1d904 FW |
6721 | for_each_possible_cpu(cpu) |
6722 | swevent_hlist_put_cpu(event, cpu); | |
6723 | } | |
6724 | ||
6725 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6726 | { | |
b28ab83c | 6727 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6728 | int err = 0; |
6729 | ||
b28ab83c | 6730 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6731 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6732 | struct swevent_hlist *hlist; |
6733 | ||
6734 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6735 | if (!hlist) { | |
6736 | err = -ENOMEM; | |
6737 | goto exit; | |
6738 | } | |
b28ab83c | 6739 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6740 | } |
b28ab83c | 6741 | swhash->hlist_refcount++; |
9ed6060d | 6742 | exit: |
b28ab83c | 6743 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6744 | |
6745 | return err; | |
6746 | } | |
6747 | ||
6748 | static int swevent_hlist_get(struct perf_event *event) | |
6749 | { | |
6750 | int err; | |
6751 | int cpu, failed_cpu; | |
6752 | ||
76e1d904 FW |
6753 | get_online_cpus(); |
6754 | for_each_possible_cpu(cpu) { | |
6755 | err = swevent_hlist_get_cpu(event, cpu); | |
6756 | if (err) { | |
6757 | failed_cpu = cpu; | |
6758 | goto fail; | |
6759 | } | |
6760 | } | |
6761 | put_online_cpus(); | |
6762 | ||
6763 | return 0; | |
9ed6060d | 6764 | fail: |
76e1d904 FW |
6765 | for_each_possible_cpu(cpu) { |
6766 | if (cpu == failed_cpu) | |
6767 | break; | |
6768 | swevent_hlist_put_cpu(event, cpu); | |
6769 | } | |
6770 | ||
6771 | put_online_cpus(); | |
6772 | return err; | |
6773 | } | |
6774 | ||
c5905afb | 6775 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6776 | |
b0a873eb PZ |
6777 | static void sw_perf_event_destroy(struct perf_event *event) |
6778 | { | |
6779 | u64 event_id = event->attr.config; | |
95476b64 | 6780 | |
b0a873eb PZ |
6781 | WARN_ON(event->parent); |
6782 | ||
c5905afb | 6783 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6784 | swevent_hlist_put(event); |
6785 | } | |
6786 | ||
6787 | static int perf_swevent_init(struct perf_event *event) | |
6788 | { | |
8176cced | 6789 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6790 | |
6791 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6792 | return -ENOENT; | |
6793 | ||
2481c5fa SE |
6794 | /* |
6795 | * no branch sampling for software events | |
6796 | */ | |
6797 | if (has_branch_stack(event)) | |
6798 | return -EOPNOTSUPP; | |
6799 | ||
b0a873eb PZ |
6800 | switch (event_id) { |
6801 | case PERF_COUNT_SW_CPU_CLOCK: | |
6802 | case PERF_COUNT_SW_TASK_CLOCK: | |
6803 | return -ENOENT; | |
6804 | ||
6805 | default: | |
6806 | break; | |
6807 | } | |
6808 | ||
ce677831 | 6809 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6810 | return -ENOENT; |
6811 | ||
6812 | if (!event->parent) { | |
6813 | int err; | |
6814 | ||
6815 | err = swevent_hlist_get(event); | |
6816 | if (err) | |
6817 | return err; | |
6818 | ||
c5905afb | 6819 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6820 | event->destroy = sw_perf_event_destroy; |
6821 | } | |
6822 | ||
6823 | return 0; | |
6824 | } | |
6825 | ||
6826 | static struct pmu perf_swevent = { | |
89a1e187 | 6827 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6828 | |
34f43927 PZ |
6829 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6830 | ||
b0a873eb | 6831 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6832 | .add = perf_swevent_add, |
6833 | .del = perf_swevent_del, | |
6834 | .start = perf_swevent_start, | |
6835 | .stop = perf_swevent_stop, | |
1c024eca | 6836 | .read = perf_swevent_read, |
1c024eca PZ |
6837 | }; |
6838 | ||
b0a873eb PZ |
6839 | #ifdef CONFIG_EVENT_TRACING |
6840 | ||
1c024eca PZ |
6841 | static int perf_tp_filter_match(struct perf_event *event, |
6842 | struct perf_sample_data *data) | |
6843 | { | |
6844 | void *record = data->raw->data; | |
6845 | ||
b71b437e PZ |
6846 | /* only top level events have filters set */ |
6847 | if (event->parent) | |
6848 | event = event->parent; | |
6849 | ||
1c024eca PZ |
6850 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6851 | return 1; | |
6852 | return 0; | |
6853 | } | |
6854 | ||
6855 | static int perf_tp_event_match(struct perf_event *event, | |
6856 | struct perf_sample_data *data, | |
6857 | struct pt_regs *regs) | |
6858 | { | |
a0f7d0f7 FW |
6859 | if (event->hw.state & PERF_HES_STOPPED) |
6860 | return 0; | |
580d607c PZ |
6861 | /* |
6862 | * All tracepoints are from kernel-space. | |
6863 | */ | |
6864 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6865 | return 0; |
6866 | ||
6867 | if (!perf_tp_filter_match(event, data)) | |
6868 | return 0; | |
6869 | ||
6870 | return 1; | |
6871 | } | |
6872 | ||
6873 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6874 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6875 | struct task_struct *task) | |
95476b64 FW |
6876 | { |
6877 | struct perf_sample_data data; | |
1c024eca | 6878 | struct perf_event *event; |
1c024eca | 6879 | |
95476b64 FW |
6880 | struct perf_raw_record raw = { |
6881 | .size = entry_size, | |
6882 | .data = record, | |
6883 | }; | |
6884 | ||
fd0d000b | 6885 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6886 | data.raw = &raw; |
6887 | ||
b67bfe0d | 6888 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6889 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6890 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6891 | } |
ecc55f84 | 6892 | |
e6dab5ff AV |
6893 | /* |
6894 | * If we got specified a target task, also iterate its context and | |
6895 | * deliver this event there too. | |
6896 | */ | |
6897 | if (task && task != current) { | |
6898 | struct perf_event_context *ctx; | |
6899 | struct trace_entry *entry = record; | |
6900 | ||
6901 | rcu_read_lock(); | |
6902 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6903 | if (!ctx) | |
6904 | goto unlock; | |
6905 | ||
6906 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6907 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6908 | continue; | |
6909 | if (event->attr.config != entry->type) | |
6910 | continue; | |
6911 | if (perf_tp_event_match(event, &data, regs)) | |
6912 | perf_swevent_event(event, count, &data, regs); | |
6913 | } | |
6914 | unlock: | |
6915 | rcu_read_unlock(); | |
6916 | } | |
6917 | ||
ecc55f84 | 6918 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6919 | } |
6920 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6921 | ||
cdd6c482 | 6922 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6923 | { |
1c024eca | 6924 | perf_trace_destroy(event); |
e077df4f PZ |
6925 | } |
6926 | ||
b0a873eb | 6927 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6928 | { |
76e1d904 FW |
6929 | int err; |
6930 | ||
b0a873eb PZ |
6931 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6932 | return -ENOENT; | |
6933 | ||
2481c5fa SE |
6934 | /* |
6935 | * no branch sampling for tracepoint events | |
6936 | */ | |
6937 | if (has_branch_stack(event)) | |
6938 | return -EOPNOTSUPP; | |
6939 | ||
1c024eca PZ |
6940 | err = perf_trace_init(event); |
6941 | if (err) | |
b0a873eb | 6942 | return err; |
e077df4f | 6943 | |
cdd6c482 | 6944 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6945 | |
b0a873eb PZ |
6946 | return 0; |
6947 | } | |
6948 | ||
6949 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6950 | .task_ctx_nr = perf_sw_context, |
6951 | ||
b0a873eb | 6952 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6953 | .add = perf_trace_add, |
6954 | .del = perf_trace_del, | |
6955 | .start = perf_swevent_start, | |
6956 | .stop = perf_swevent_stop, | |
b0a873eb | 6957 | .read = perf_swevent_read, |
b0a873eb PZ |
6958 | }; |
6959 | ||
6960 | static inline void perf_tp_register(void) | |
6961 | { | |
2e80a82a | 6962 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6963 | } |
6fb2915d LZ |
6964 | |
6965 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6966 | { | |
6967 | char *filter_str; | |
6968 | int ret; | |
6969 | ||
6970 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6971 | return -EINVAL; | |
6972 | ||
6973 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6974 | if (IS_ERR(filter_str)) | |
6975 | return PTR_ERR(filter_str); | |
6976 | ||
6977 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6978 | ||
6979 | kfree(filter_str); | |
6980 | return ret; | |
6981 | } | |
6982 | ||
6983 | static void perf_event_free_filter(struct perf_event *event) | |
6984 | { | |
6985 | ftrace_profile_free_filter(event); | |
6986 | } | |
6987 | ||
2541517c AS |
6988 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
6989 | { | |
6990 | struct bpf_prog *prog; | |
6991 | ||
6992 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6993 | return -EINVAL; | |
6994 | ||
6995 | if (event->tp_event->prog) | |
6996 | return -EEXIST; | |
6997 | ||
04a22fae WN |
6998 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
6999 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7000 | return -EINVAL; |
7001 | ||
7002 | prog = bpf_prog_get(prog_fd); | |
7003 | if (IS_ERR(prog)) | |
7004 | return PTR_ERR(prog); | |
7005 | ||
6c373ca8 | 7006 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7007 | /* valid fd, but invalid bpf program type */ |
7008 | bpf_prog_put(prog); | |
7009 | return -EINVAL; | |
7010 | } | |
7011 | ||
7012 | event->tp_event->prog = prog; | |
7013 | ||
7014 | return 0; | |
7015 | } | |
7016 | ||
7017 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7018 | { | |
7019 | struct bpf_prog *prog; | |
7020 | ||
7021 | if (!event->tp_event) | |
7022 | return; | |
7023 | ||
7024 | prog = event->tp_event->prog; | |
7025 | if (prog) { | |
7026 | event->tp_event->prog = NULL; | |
7027 | bpf_prog_put(prog); | |
7028 | } | |
7029 | } | |
7030 | ||
e077df4f | 7031 | #else |
6fb2915d | 7032 | |
b0a873eb | 7033 | static inline void perf_tp_register(void) |
e077df4f | 7034 | { |
e077df4f | 7035 | } |
6fb2915d LZ |
7036 | |
7037 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7038 | { | |
7039 | return -ENOENT; | |
7040 | } | |
7041 | ||
7042 | static void perf_event_free_filter(struct perf_event *event) | |
7043 | { | |
7044 | } | |
7045 | ||
2541517c AS |
7046 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7047 | { | |
7048 | return -ENOENT; | |
7049 | } | |
7050 | ||
7051 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7052 | { | |
7053 | } | |
07b139c8 | 7054 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7055 | |
24f1e32c | 7056 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7057 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7058 | { |
f5ffe02e FW |
7059 | struct perf_sample_data sample; |
7060 | struct pt_regs *regs = data; | |
7061 | ||
fd0d000b | 7062 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7063 | |
a4eaf7f1 | 7064 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7065 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7066 | } |
7067 | #endif | |
7068 | ||
b0a873eb PZ |
7069 | /* |
7070 | * hrtimer based swevent callback | |
7071 | */ | |
f29ac756 | 7072 | |
b0a873eb | 7073 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7074 | { |
b0a873eb PZ |
7075 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7076 | struct perf_sample_data data; | |
7077 | struct pt_regs *regs; | |
7078 | struct perf_event *event; | |
7079 | u64 period; | |
f29ac756 | 7080 | |
b0a873eb | 7081 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7082 | |
7083 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7084 | return HRTIMER_NORESTART; | |
7085 | ||
b0a873eb | 7086 | event->pmu->read(event); |
f344011c | 7087 | |
fd0d000b | 7088 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7089 | regs = get_irq_regs(); |
7090 | ||
7091 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7092 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7093 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7094 | ret = HRTIMER_NORESTART; |
7095 | } | |
24f1e32c | 7096 | |
b0a873eb PZ |
7097 | period = max_t(u64, 10000, event->hw.sample_period); |
7098 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7099 | |
b0a873eb | 7100 | return ret; |
f29ac756 PZ |
7101 | } |
7102 | ||
b0a873eb | 7103 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7104 | { |
b0a873eb | 7105 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7106 | s64 period; |
7107 | ||
7108 | if (!is_sampling_event(event)) | |
7109 | return; | |
f5ffe02e | 7110 | |
5d508e82 FBH |
7111 | period = local64_read(&hwc->period_left); |
7112 | if (period) { | |
7113 | if (period < 0) | |
7114 | period = 10000; | |
fa407f35 | 7115 | |
5d508e82 FBH |
7116 | local64_set(&hwc->period_left, 0); |
7117 | } else { | |
7118 | period = max_t(u64, 10000, hwc->sample_period); | |
7119 | } | |
3497d206 TG |
7120 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7121 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7122 | } |
b0a873eb PZ |
7123 | |
7124 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7125 | { |
b0a873eb PZ |
7126 | struct hw_perf_event *hwc = &event->hw; |
7127 | ||
6c7e550f | 7128 | if (is_sampling_event(event)) { |
b0a873eb | 7129 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7130 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7131 | |
7132 | hrtimer_cancel(&hwc->hrtimer); | |
7133 | } | |
24f1e32c FW |
7134 | } |
7135 | ||
ba3dd36c PZ |
7136 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7137 | { | |
7138 | struct hw_perf_event *hwc = &event->hw; | |
7139 | ||
7140 | if (!is_sampling_event(event)) | |
7141 | return; | |
7142 | ||
7143 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7144 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7145 | ||
7146 | /* | |
7147 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7148 | * mapping and avoid the whole period adjust feedback stuff. | |
7149 | */ | |
7150 | if (event->attr.freq) { | |
7151 | long freq = event->attr.sample_freq; | |
7152 | ||
7153 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7154 | hwc->sample_period = event->attr.sample_period; | |
7155 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7156 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7157 | event->attr.freq = 0; |
7158 | } | |
7159 | } | |
7160 | ||
b0a873eb PZ |
7161 | /* |
7162 | * Software event: cpu wall time clock | |
7163 | */ | |
7164 | ||
7165 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7166 | { |
b0a873eb PZ |
7167 | s64 prev; |
7168 | u64 now; | |
7169 | ||
a4eaf7f1 | 7170 | now = local_clock(); |
b0a873eb PZ |
7171 | prev = local64_xchg(&event->hw.prev_count, now); |
7172 | local64_add(now - prev, &event->count); | |
24f1e32c | 7173 | } |
24f1e32c | 7174 | |
a4eaf7f1 | 7175 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7176 | { |
a4eaf7f1 | 7177 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7178 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7179 | } |
7180 | ||
a4eaf7f1 | 7181 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7182 | { |
b0a873eb PZ |
7183 | perf_swevent_cancel_hrtimer(event); |
7184 | cpu_clock_event_update(event); | |
7185 | } | |
f29ac756 | 7186 | |
a4eaf7f1 PZ |
7187 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7188 | { | |
7189 | if (flags & PERF_EF_START) | |
7190 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7191 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7192 | |
7193 | return 0; | |
7194 | } | |
7195 | ||
7196 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7197 | { | |
7198 | cpu_clock_event_stop(event, flags); | |
7199 | } | |
7200 | ||
b0a873eb PZ |
7201 | static void cpu_clock_event_read(struct perf_event *event) |
7202 | { | |
7203 | cpu_clock_event_update(event); | |
7204 | } | |
f344011c | 7205 | |
b0a873eb PZ |
7206 | static int cpu_clock_event_init(struct perf_event *event) |
7207 | { | |
7208 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7209 | return -ENOENT; | |
7210 | ||
7211 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7212 | return -ENOENT; | |
7213 | ||
2481c5fa SE |
7214 | /* |
7215 | * no branch sampling for software events | |
7216 | */ | |
7217 | if (has_branch_stack(event)) | |
7218 | return -EOPNOTSUPP; | |
7219 | ||
ba3dd36c PZ |
7220 | perf_swevent_init_hrtimer(event); |
7221 | ||
b0a873eb | 7222 | return 0; |
f29ac756 PZ |
7223 | } |
7224 | ||
b0a873eb | 7225 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7226 | .task_ctx_nr = perf_sw_context, |
7227 | ||
34f43927 PZ |
7228 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7229 | ||
b0a873eb | 7230 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7231 | .add = cpu_clock_event_add, |
7232 | .del = cpu_clock_event_del, | |
7233 | .start = cpu_clock_event_start, | |
7234 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7235 | .read = cpu_clock_event_read, |
7236 | }; | |
7237 | ||
7238 | /* | |
7239 | * Software event: task time clock | |
7240 | */ | |
7241 | ||
7242 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7243 | { |
b0a873eb PZ |
7244 | u64 prev; |
7245 | s64 delta; | |
5c92d124 | 7246 | |
b0a873eb PZ |
7247 | prev = local64_xchg(&event->hw.prev_count, now); |
7248 | delta = now - prev; | |
7249 | local64_add(delta, &event->count); | |
7250 | } | |
5c92d124 | 7251 | |
a4eaf7f1 | 7252 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7253 | { |
a4eaf7f1 | 7254 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7255 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7256 | } |
7257 | ||
a4eaf7f1 | 7258 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7259 | { |
7260 | perf_swevent_cancel_hrtimer(event); | |
7261 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7262 | } |
7263 | ||
7264 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7265 | { | |
7266 | if (flags & PERF_EF_START) | |
7267 | task_clock_event_start(event, flags); | |
6a694a60 | 7268 | perf_event_update_userpage(event); |
b0a873eb | 7269 | |
a4eaf7f1 PZ |
7270 | return 0; |
7271 | } | |
7272 | ||
7273 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7274 | { | |
7275 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7276 | } |
7277 | ||
7278 | static void task_clock_event_read(struct perf_event *event) | |
7279 | { | |
768a06e2 PZ |
7280 | u64 now = perf_clock(); |
7281 | u64 delta = now - event->ctx->timestamp; | |
7282 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7283 | |
7284 | task_clock_event_update(event, time); | |
7285 | } | |
7286 | ||
7287 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7288 | { |
b0a873eb PZ |
7289 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7290 | return -ENOENT; | |
7291 | ||
7292 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7293 | return -ENOENT; | |
7294 | ||
2481c5fa SE |
7295 | /* |
7296 | * no branch sampling for software events | |
7297 | */ | |
7298 | if (has_branch_stack(event)) | |
7299 | return -EOPNOTSUPP; | |
7300 | ||
ba3dd36c PZ |
7301 | perf_swevent_init_hrtimer(event); |
7302 | ||
b0a873eb | 7303 | return 0; |
6fb2915d LZ |
7304 | } |
7305 | ||
b0a873eb | 7306 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7307 | .task_ctx_nr = perf_sw_context, |
7308 | ||
34f43927 PZ |
7309 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7310 | ||
b0a873eb | 7311 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7312 | .add = task_clock_event_add, |
7313 | .del = task_clock_event_del, | |
7314 | .start = task_clock_event_start, | |
7315 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7316 | .read = task_clock_event_read, |
7317 | }; | |
6fb2915d | 7318 | |
ad5133b7 | 7319 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7320 | { |
e077df4f | 7321 | } |
6fb2915d | 7322 | |
fbbe0701 SB |
7323 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7324 | { | |
7325 | } | |
7326 | ||
ad5133b7 | 7327 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7328 | { |
ad5133b7 | 7329 | return 0; |
6fb2915d LZ |
7330 | } |
7331 | ||
18ab2cd3 | 7332 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7333 | |
7334 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7335 | { |
fbbe0701 SB |
7336 | __this_cpu_write(nop_txn_flags, flags); |
7337 | ||
7338 | if (flags & ~PERF_PMU_TXN_ADD) | |
7339 | return; | |
7340 | ||
ad5133b7 | 7341 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7342 | } |
7343 | ||
ad5133b7 PZ |
7344 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7345 | { | |
fbbe0701 SB |
7346 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7347 | ||
7348 | __this_cpu_write(nop_txn_flags, 0); | |
7349 | ||
7350 | if (flags & ~PERF_PMU_TXN_ADD) | |
7351 | return 0; | |
7352 | ||
ad5133b7 PZ |
7353 | perf_pmu_enable(pmu); |
7354 | return 0; | |
7355 | } | |
e077df4f | 7356 | |
ad5133b7 | 7357 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7358 | { |
fbbe0701 SB |
7359 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7360 | ||
7361 | __this_cpu_write(nop_txn_flags, 0); | |
7362 | ||
7363 | if (flags & ~PERF_PMU_TXN_ADD) | |
7364 | return; | |
7365 | ||
ad5133b7 | 7366 | perf_pmu_enable(pmu); |
24f1e32c FW |
7367 | } |
7368 | ||
35edc2a5 PZ |
7369 | static int perf_event_idx_default(struct perf_event *event) |
7370 | { | |
c719f560 | 7371 | return 0; |
35edc2a5 PZ |
7372 | } |
7373 | ||
8dc85d54 PZ |
7374 | /* |
7375 | * Ensures all contexts with the same task_ctx_nr have the same | |
7376 | * pmu_cpu_context too. | |
7377 | */ | |
9e317041 | 7378 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7379 | { |
8dc85d54 | 7380 | struct pmu *pmu; |
b326e956 | 7381 | |
8dc85d54 PZ |
7382 | if (ctxn < 0) |
7383 | return NULL; | |
24f1e32c | 7384 | |
8dc85d54 PZ |
7385 | list_for_each_entry(pmu, &pmus, entry) { |
7386 | if (pmu->task_ctx_nr == ctxn) | |
7387 | return pmu->pmu_cpu_context; | |
7388 | } | |
24f1e32c | 7389 | |
8dc85d54 | 7390 | return NULL; |
24f1e32c FW |
7391 | } |
7392 | ||
51676957 | 7393 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7394 | { |
51676957 PZ |
7395 | int cpu; |
7396 | ||
7397 | for_each_possible_cpu(cpu) { | |
7398 | struct perf_cpu_context *cpuctx; | |
7399 | ||
7400 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7401 | ||
3f1f3320 PZ |
7402 | if (cpuctx->unique_pmu == old_pmu) |
7403 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7404 | } |
7405 | } | |
7406 | ||
7407 | static void free_pmu_context(struct pmu *pmu) | |
7408 | { | |
7409 | struct pmu *i; | |
f5ffe02e | 7410 | |
8dc85d54 | 7411 | mutex_lock(&pmus_lock); |
0475f9ea | 7412 | /* |
8dc85d54 | 7413 | * Like a real lame refcount. |
0475f9ea | 7414 | */ |
51676957 PZ |
7415 | list_for_each_entry(i, &pmus, entry) { |
7416 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7417 | update_pmu_context(i, pmu); | |
8dc85d54 | 7418 | goto out; |
51676957 | 7419 | } |
8dc85d54 | 7420 | } |
d6d020e9 | 7421 | |
51676957 | 7422 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7423 | out: |
7424 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7425 | } |
2e80a82a | 7426 | static struct idr pmu_idr; |
d6d020e9 | 7427 | |
abe43400 PZ |
7428 | static ssize_t |
7429 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7430 | { | |
7431 | struct pmu *pmu = dev_get_drvdata(dev); | |
7432 | ||
7433 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7434 | } | |
90826ca7 | 7435 | static DEVICE_ATTR_RO(type); |
abe43400 | 7436 | |
62b85639 SE |
7437 | static ssize_t |
7438 | perf_event_mux_interval_ms_show(struct device *dev, | |
7439 | struct device_attribute *attr, | |
7440 | char *page) | |
7441 | { | |
7442 | struct pmu *pmu = dev_get_drvdata(dev); | |
7443 | ||
7444 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7445 | } | |
7446 | ||
272325c4 PZ |
7447 | static DEFINE_MUTEX(mux_interval_mutex); |
7448 | ||
62b85639 SE |
7449 | static ssize_t |
7450 | perf_event_mux_interval_ms_store(struct device *dev, | |
7451 | struct device_attribute *attr, | |
7452 | const char *buf, size_t count) | |
7453 | { | |
7454 | struct pmu *pmu = dev_get_drvdata(dev); | |
7455 | int timer, cpu, ret; | |
7456 | ||
7457 | ret = kstrtoint(buf, 0, &timer); | |
7458 | if (ret) | |
7459 | return ret; | |
7460 | ||
7461 | if (timer < 1) | |
7462 | return -EINVAL; | |
7463 | ||
7464 | /* same value, noting to do */ | |
7465 | if (timer == pmu->hrtimer_interval_ms) | |
7466 | return count; | |
7467 | ||
272325c4 | 7468 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7469 | pmu->hrtimer_interval_ms = timer; |
7470 | ||
7471 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7472 | get_online_cpus(); |
7473 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7474 | struct perf_cpu_context *cpuctx; |
7475 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7476 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7477 | ||
272325c4 PZ |
7478 | cpu_function_call(cpu, |
7479 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7480 | } |
272325c4 PZ |
7481 | put_online_cpus(); |
7482 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7483 | |
7484 | return count; | |
7485 | } | |
90826ca7 | 7486 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7487 | |
90826ca7 GKH |
7488 | static struct attribute *pmu_dev_attrs[] = { |
7489 | &dev_attr_type.attr, | |
7490 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7491 | NULL, | |
abe43400 | 7492 | }; |
90826ca7 | 7493 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7494 | |
7495 | static int pmu_bus_running; | |
7496 | static struct bus_type pmu_bus = { | |
7497 | .name = "event_source", | |
90826ca7 | 7498 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7499 | }; |
7500 | ||
7501 | static void pmu_dev_release(struct device *dev) | |
7502 | { | |
7503 | kfree(dev); | |
7504 | } | |
7505 | ||
7506 | static int pmu_dev_alloc(struct pmu *pmu) | |
7507 | { | |
7508 | int ret = -ENOMEM; | |
7509 | ||
7510 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7511 | if (!pmu->dev) | |
7512 | goto out; | |
7513 | ||
0c9d42ed | 7514 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7515 | device_initialize(pmu->dev); |
7516 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7517 | if (ret) | |
7518 | goto free_dev; | |
7519 | ||
7520 | dev_set_drvdata(pmu->dev, pmu); | |
7521 | pmu->dev->bus = &pmu_bus; | |
7522 | pmu->dev->release = pmu_dev_release; | |
7523 | ret = device_add(pmu->dev); | |
7524 | if (ret) | |
7525 | goto free_dev; | |
7526 | ||
7527 | out: | |
7528 | return ret; | |
7529 | ||
7530 | free_dev: | |
7531 | put_device(pmu->dev); | |
7532 | goto out; | |
7533 | } | |
7534 | ||
547e9fd7 | 7535 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7536 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7537 | |
03d8e80b | 7538 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7539 | { |
108b02cf | 7540 | int cpu, ret; |
24f1e32c | 7541 | |
b0a873eb | 7542 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7543 | ret = -ENOMEM; |
7544 | pmu->pmu_disable_count = alloc_percpu(int); | |
7545 | if (!pmu->pmu_disable_count) | |
7546 | goto unlock; | |
f29ac756 | 7547 | |
2e80a82a PZ |
7548 | pmu->type = -1; |
7549 | if (!name) | |
7550 | goto skip_type; | |
7551 | pmu->name = name; | |
7552 | ||
7553 | if (type < 0) { | |
0e9c3be2 TH |
7554 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7555 | if (type < 0) { | |
7556 | ret = type; | |
2e80a82a PZ |
7557 | goto free_pdc; |
7558 | } | |
7559 | } | |
7560 | pmu->type = type; | |
7561 | ||
abe43400 PZ |
7562 | if (pmu_bus_running) { |
7563 | ret = pmu_dev_alloc(pmu); | |
7564 | if (ret) | |
7565 | goto free_idr; | |
7566 | } | |
7567 | ||
2e80a82a | 7568 | skip_type: |
8dc85d54 PZ |
7569 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7570 | if (pmu->pmu_cpu_context) | |
7571 | goto got_cpu_context; | |
f29ac756 | 7572 | |
c4814202 | 7573 | ret = -ENOMEM; |
108b02cf PZ |
7574 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7575 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7576 | goto free_dev; |
f344011c | 7577 | |
108b02cf PZ |
7578 | for_each_possible_cpu(cpu) { |
7579 | struct perf_cpu_context *cpuctx; | |
7580 | ||
7581 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7582 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7583 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7584 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7585 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7586 | |
272325c4 | 7587 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7588 | |
3f1f3320 | 7589 | cpuctx->unique_pmu = pmu; |
108b02cf | 7590 | } |
76e1d904 | 7591 | |
8dc85d54 | 7592 | got_cpu_context: |
ad5133b7 PZ |
7593 | if (!pmu->start_txn) { |
7594 | if (pmu->pmu_enable) { | |
7595 | /* | |
7596 | * If we have pmu_enable/pmu_disable calls, install | |
7597 | * transaction stubs that use that to try and batch | |
7598 | * hardware accesses. | |
7599 | */ | |
7600 | pmu->start_txn = perf_pmu_start_txn; | |
7601 | pmu->commit_txn = perf_pmu_commit_txn; | |
7602 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7603 | } else { | |
fbbe0701 | 7604 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7605 | pmu->commit_txn = perf_pmu_nop_int; |
7606 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7607 | } |
5c92d124 | 7608 | } |
15dbf27c | 7609 | |
ad5133b7 PZ |
7610 | if (!pmu->pmu_enable) { |
7611 | pmu->pmu_enable = perf_pmu_nop_void; | |
7612 | pmu->pmu_disable = perf_pmu_nop_void; | |
7613 | } | |
7614 | ||
35edc2a5 PZ |
7615 | if (!pmu->event_idx) |
7616 | pmu->event_idx = perf_event_idx_default; | |
7617 | ||
b0a873eb | 7618 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7619 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7620 | ret = 0; |
7621 | unlock: | |
b0a873eb PZ |
7622 | mutex_unlock(&pmus_lock); |
7623 | ||
33696fc0 | 7624 | return ret; |
108b02cf | 7625 | |
abe43400 PZ |
7626 | free_dev: |
7627 | device_del(pmu->dev); | |
7628 | put_device(pmu->dev); | |
7629 | ||
2e80a82a PZ |
7630 | free_idr: |
7631 | if (pmu->type >= PERF_TYPE_MAX) | |
7632 | idr_remove(&pmu_idr, pmu->type); | |
7633 | ||
108b02cf PZ |
7634 | free_pdc: |
7635 | free_percpu(pmu->pmu_disable_count); | |
7636 | goto unlock; | |
f29ac756 | 7637 | } |
c464c76e | 7638 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7639 | |
b0a873eb | 7640 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7641 | { |
b0a873eb PZ |
7642 | mutex_lock(&pmus_lock); |
7643 | list_del_rcu(&pmu->entry); | |
7644 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7645 | |
0475f9ea | 7646 | /* |
cde8e884 PZ |
7647 | * We dereference the pmu list under both SRCU and regular RCU, so |
7648 | * synchronize against both of those. | |
0475f9ea | 7649 | */ |
b0a873eb | 7650 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7651 | synchronize_rcu(); |
d6d020e9 | 7652 | |
33696fc0 | 7653 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7654 | if (pmu->type >= PERF_TYPE_MAX) |
7655 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7656 | device_del(pmu->dev); |
7657 | put_device(pmu->dev); | |
51676957 | 7658 | free_pmu_context(pmu); |
b0a873eb | 7659 | } |
c464c76e | 7660 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7661 | |
cc34b98b MR |
7662 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7663 | { | |
ccd41c86 | 7664 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7665 | int ret; |
7666 | ||
7667 | if (!try_module_get(pmu->module)) | |
7668 | return -ENODEV; | |
ccd41c86 PZ |
7669 | |
7670 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7671 | /* |
7672 | * This ctx->mutex can nest when we're called through | |
7673 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7674 | */ | |
7675 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7676 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7677 | BUG_ON(!ctx); |
7678 | } | |
7679 | ||
cc34b98b MR |
7680 | event->pmu = pmu; |
7681 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7682 | |
7683 | if (ctx) | |
7684 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7685 | ||
cc34b98b MR |
7686 | if (ret) |
7687 | module_put(pmu->module); | |
7688 | ||
7689 | return ret; | |
7690 | } | |
7691 | ||
18ab2cd3 | 7692 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7693 | { |
7694 | struct pmu *pmu = NULL; | |
7695 | int idx; | |
940c5b29 | 7696 | int ret; |
b0a873eb PZ |
7697 | |
7698 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7699 | |
7700 | rcu_read_lock(); | |
7701 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7702 | rcu_read_unlock(); | |
940c5b29 | 7703 | if (pmu) { |
cc34b98b | 7704 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7705 | if (ret) |
7706 | pmu = ERR_PTR(ret); | |
2e80a82a | 7707 | goto unlock; |
940c5b29 | 7708 | } |
2e80a82a | 7709 | |
b0a873eb | 7710 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7711 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7712 | if (!ret) |
e5f4d339 | 7713 | goto unlock; |
76e1d904 | 7714 | |
b0a873eb PZ |
7715 | if (ret != -ENOENT) { |
7716 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7717 | goto unlock; |
f344011c | 7718 | } |
5c92d124 | 7719 | } |
e5f4d339 PZ |
7720 | pmu = ERR_PTR(-ENOENT); |
7721 | unlock: | |
b0a873eb | 7722 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7723 | |
4aeb0b42 | 7724 | return pmu; |
5c92d124 IM |
7725 | } |
7726 | ||
4beb31f3 FW |
7727 | static void account_event_cpu(struct perf_event *event, int cpu) |
7728 | { | |
7729 | if (event->parent) | |
7730 | return; | |
7731 | ||
4beb31f3 FW |
7732 | if (is_cgroup_event(event)) |
7733 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7734 | } | |
7735 | ||
766d6c07 FW |
7736 | static void account_event(struct perf_event *event) |
7737 | { | |
25432ae9 PZ |
7738 | bool inc = false; |
7739 | ||
4beb31f3 FW |
7740 | if (event->parent) |
7741 | return; | |
7742 | ||
766d6c07 | 7743 | if (event->attach_state & PERF_ATTACH_TASK) |
25432ae9 | 7744 | inc = true; |
766d6c07 FW |
7745 | if (event->attr.mmap || event->attr.mmap_data) |
7746 | atomic_inc(&nr_mmap_events); | |
7747 | if (event->attr.comm) | |
7748 | atomic_inc(&nr_comm_events); | |
7749 | if (event->attr.task) | |
7750 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7751 | if (event->attr.freq) { |
7752 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7753 | tick_nohz_full_kick_all(); | |
7754 | } | |
45ac1403 AH |
7755 | if (event->attr.context_switch) { |
7756 | atomic_inc(&nr_switch_events); | |
25432ae9 | 7757 | inc = true; |
45ac1403 | 7758 | } |
4beb31f3 | 7759 | if (has_branch_stack(event)) |
25432ae9 | 7760 | inc = true; |
4beb31f3 | 7761 | if (is_cgroup_event(event)) |
25432ae9 PZ |
7762 | inc = true; |
7763 | ||
7764 | if (inc) | |
766d6c07 | 7765 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7766 | |
7767 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7768 | } |
7769 | ||
0793a61d | 7770 | /* |
cdd6c482 | 7771 | * Allocate and initialize a event structure |
0793a61d | 7772 | */ |
cdd6c482 | 7773 | static struct perf_event * |
c3f00c70 | 7774 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7775 | struct task_struct *task, |
7776 | struct perf_event *group_leader, | |
7777 | struct perf_event *parent_event, | |
4dc0da86 | 7778 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7779 | void *context, int cgroup_fd) |
0793a61d | 7780 | { |
51b0fe39 | 7781 | struct pmu *pmu; |
cdd6c482 IM |
7782 | struct perf_event *event; |
7783 | struct hw_perf_event *hwc; | |
90983b16 | 7784 | long err = -EINVAL; |
0793a61d | 7785 | |
66832eb4 ON |
7786 | if ((unsigned)cpu >= nr_cpu_ids) { |
7787 | if (!task || cpu != -1) | |
7788 | return ERR_PTR(-EINVAL); | |
7789 | } | |
7790 | ||
c3f00c70 | 7791 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7792 | if (!event) |
d5d2bc0d | 7793 | return ERR_PTR(-ENOMEM); |
0793a61d | 7794 | |
04289bb9 | 7795 | /* |
cdd6c482 | 7796 | * Single events are their own group leaders, with an |
04289bb9 IM |
7797 | * empty sibling list: |
7798 | */ | |
7799 | if (!group_leader) | |
cdd6c482 | 7800 | group_leader = event; |
04289bb9 | 7801 | |
cdd6c482 IM |
7802 | mutex_init(&event->child_mutex); |
7803 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7804 | |
cdd6c482 IM |
7805 | INIT_LIST_HEAD(&event->group_entry); |
7806 | INIT_LIST_HEAD(&event->event_entry); | |
7807 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7808 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7809 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7810 | INIT_HLIST_NODE(&event->hlist_entry); |
7811 | ||
10c6db11 | 7812 | |
cdd6c482 | 7813 | init_waitqueue_head(&event->waitq); |
e360adbe | 7814 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7815 | |
cdd6c482 | 7816 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7817 | |
a6fa941d | 7818 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7819 | event->cpu = cpu; |
7820 | event->attr = *attr; | |
7821 | event->group_leader = group_leader; | |
7822 | event->pmu = NULL; | |
cdd6c482 | 7823 | event->oncpu = -1; |
a96bbc16 | 7824 | |
cdd6c482 | 7825 | event->parent = parent_event; |
b84fbc9f | 7826 | |
17cf22c3 | 7827 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7828 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7829 | |
cdd6c482 | 7830 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7831 | |
d580ff86 PZ |
7832 | if (task) { |
7833 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7834 | /* |
50f16a8b PZ |
7835 | * XXX pmu::event_init needs to know what task to account to |
7836 | * and we cannot use the ctx information because we need the | |
7837 | * pmu before we get a ctx. | |
d580ff86 | 7838 | */ |
50f16a8b | 7839 | event->hw.target = task; |
d580ff86 PZ |
7840 | } |
7841 | ||
34f43927 PZ |
7842 | event->clock = &local_clock; |
7843 | if (parent_event) | |
7844 | event->clock = parent_event->clock; | |
7845 | ||
4dc0da86 | 7846 | if (!overflow_handler && parent_event) { |
b326e956 | 7847 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7848 | context = parent_event->overflow_handler_context; |
7849 | } | |
66832eb4 | 7850 | |
b326e956 | 7851 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7852 | event->overflow_handler_context = context; |
97eaf530 | 7853 | |
0231bb53 | 7854 | perf_event__state_init(event); |
a86ed508 | 7855 | |
4aeb0b42 | 7856 | pmu = NULL; |
b8e83514 | 7857 | |
cdd6c482 | 7858 | hwc = &event->hw; |
bd2b5b12 | 7859 | hwc->sample_period = attr->sample_period; |
0d48696f | 7860 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7861 | hwc->sample_period = 1; |
eced1dfc | 7862 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7863 | |
e7850595 | 7864 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7865 | |
2023b359 | 7866 | /* |
cdd6c482 | 7867 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7868 | */ |
3dab77fb | 7869 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7870 | goto err_ns; |
a46a2300 YZ |
7871 | |
7872 | if (!has_branch_stack(event)) | |
7873 | event->attr.branch_sample_type = 0; | |
2023b359 | 7874 | |
79dff51e MF |
7875 | if (cgroup_fd != -1) { |
7876 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7877 | if (err) | |
7878 | goto err_ns; | |
7879 | } | |
7880 | ||
b0a873eb | 7881 | pmu = perf_init_event(event); |
4aeb0b42 | 7882 | if (!pmu) |
90983b16 FW |
7883 | goto err_ns; |
7884 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7885 | err = PTR_ERR(pmu); |
90983b16 | 7886 | goto err_ns; |
621a01ea | 7887 | } |
d5d2bc0d | 7888 | |
bed5b25a AS |
7889 | err = exclusive_event_init(event); |
7890 | if (err) | |
7891 | goto err_pmu; | |
7892 | ||
cdd6c482 | 7893 | if (!event->parent) { |
927c7a9e FW |
7894 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7895 | err = get_callchain_buffers(); | |
90983b16 | 7896 | if (err) |
bed5b25a | 7897 | goto err_per_task; |
d010b332 | 7898 | } |
f344011c | 7899 | } |
9ee318a7 | 7900 | |
cdd6c482 | 7901 | return event; |
90983b16 | 7902 | |
bed5b25a AS |
7903 | err_per_task: |
7904 | exclusive_event_destroy(event); | |
7905 | ||
90983b16 FW |
7906 | err_pmu: |
7907 | if (event->destroy) | |
7908 | event->destroy(event); | |
c464c76e | 7909 | module_put(pmu->module); |
90983b16 | 7910 | err_ns: |
79dff51e MF |
7911 | if (is_cgroup_event(event)) |
7912 | perf_detach_cgroup(event); | |
90983b16 FW |
7913 | if (event->ns) |
7914 | put_pid_ns(event->ns); | |
7915 | kfree(event); | |
7916 | ||
7917 | return ERR_PTR(err); | |
0793a61d TG |
7918 | } |
7919 | ||
cdd6c482 IM |
7920 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7921 | struct perf_event_attr *attr) | |
974802ea | 7922 | { |
974802ea | 7923 | u32 size; |
cdf8073d | 7924 | int ret; |
974802ea PZ |
7925 | |
7926 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7927 | return -EFAULT; | |
7928 | ||
7929 | /* | |
7930 | * zero the full structure, so that a short copy will be nice. | |
7931 | */ | |
7932 | memset(attr, 0, sizeof(*attr)); | |
7933 | ||
7934 | ret = get_user(size, &uattr->size); | |
7935 | if (ret) | |
7936 | return ret; | |
7937 | ||
7938 | if (size > PAGE_SIZE) /* silly large */ | |
7939 | goto err_size; | |
7940 | ||
7941 | if (!size) /* abi compat */ | |
7942 | size = PERF_ATTR_SIZE_VER0; | |
7943 | ||
7944 | if (size < PERF_ATTR_SIZE_VER0) | |
7945 | goto err_size; | |
7946 | ||
7947 | /* | |
7948 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7949 | * ensure all the unknown bits are 0 - i.e. new |
7950 | * user-space does not rely on any kernel feature | |
7951 | * extensions we dont know about yet. | |
974802ea PZ |
7952 | */ |
7953 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7954 | unsigned char __user *addr; |
7955 | unsigned char __user *end; | |
7956 | unsigned char val; | |
974802ea | 7957 | |
cdf8073d IS |
7958 | addr = (void __user *)uattr + sizeof(*attr); |
7959 | end = (void __user *)uattr + size; | |
974802ea | 7960 | |
cdf8073d | 7961 | for (; addr < end; addr++) { |
974802ea PZ |
7962 | ret = get_user(val, addr); |
7963 | if (ret) | |
7964 | return ret; | |
7965 | if (val) | |
7966 | goto err_size; | |
7967 | } | |
b3e62e35 | 7968 | size = sizeof(*attr); |
974802ea PZ |
7969 | } |
7970 | ||
7971 | ret = copy_from_user(attr, uattr, size); | |
7972 | if (ret) | |
7973 | return -EFAULT; | |
7974 | ||
cd757645 | 7975 | if (attr->__reserved_1) |
974802ea PZ |
7976 | return -EINVAL; |
7977 | ||
7978 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7979 | return -EINVAL; | |
7980 | ||
7981 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
7982 | return -EINVAL; | |
7983 | ||
bce38cd5 SE |
7984 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
7985 | u64 mask = attr->branch_sample_type; | |
7986 | ||
7987 | /* only using defined bits */ | |
7988 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
7989 | return -EINVAL; | |
7990 | ||
7991 | /* at least one branch bit must be set */ | |
7992 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
7993 | return -EINVAL; | |
7994 | ||
bce38cd5 SE |
7995 | /* propagate priv level, when not set for branch */ |
7996 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
7997 | ||
7998 | /* exclude_kernel checked on syscall entry */ | |
7999 | if (!attr->exclude_kernel) | |
8000 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8001 | ||
8002 | if (!attr->exclude_user) | |
8003 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8004 | ||
8005 | if (!attr->exclude_hv) | |
8006 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8007 | /* | |
8008 | * adjust user setting (for HW filter setup) | |
8009 | */ | |
8010 | attr->branch_sample_type = mask; | |
8011 | } | |
e712209a SE |
8012 | /* privileged levels capture (kernel, hv): check permissions */ |
8013 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8014 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8015 | return -EACCES; | |
bce38cd5 | 8016 | } |
4018994f | 8017 | |
c5ebcedb | 8018 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8019 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8020 | if (ret) |
8021 | return ret; | |
8022 | } | |
8023 | ||
8024 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8025 | if (!arch_perf_have_user_stack_dump()) | |
8026 | return -ENOSYS; | |
8027 | ||
8028 | /* | |
8029 | * We have __u32 type for the size, but so far | |
8030 | * we can only use __u16 as maximum due to the | |
8031 | * __u16 sample size limit. | |
8032 | */ | |
8033 | if (attr->sample_stack_user >= USHRT_MAX) | |
8034 | ret = -EINVAL; | |
8035 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8036 | ret = -EINVAL; | |
8037 | } | |
4018994f | 8038 | |
60e2364e SE |
8039 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8040 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8041 | out: |
8042 | return ret; | |
8043 | ||
8044 | err_size: | |
8045 | put_user(sizeof(*attr), &uattr->size); | |
8046 | ret = -E2BIG; | |
8047 | goto out; | |
8048 | } | |
8049 | ||
ac9721f3 PZ |
8050 | static int |
8051 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8052 | { |
b69cf536 | 8053 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8054 | int ret = -EINVAL; |
8055 | ||
ac9721f3 | 8056 | if (!output_event) |
a4be7c27 PZ |
8057 | goto set; |
8058 | ||
ac9721f3 PZ |
8059 | /* don't allow circular references */ |
8060 | if (event == output_event) | |
a4be7c27 PZ |
8061 | goto out; |
8062 | ||
0f139300 PZ |
8063 | /* |
8064 | * Don't allow cross-cpu buffers | |
8065 | */ | |
8066 | if (output_event->cpu != event->cpu) | |
8067 | goto out; | |
8068 | ||
8069 | /* | |
76369139 | 8070 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8071 | */ |
8072 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8073 | goto out; | |
8074 | ||
34f43927 PZ |
8075 | /* |
8076 | * Mixing clocks in the same buffer is trouble you don't need. | |
8077 | */ | |
8078 | if (output_event->clock != event->clock) | |
8079 | goto out; | |
8080 | ||
45bfb2e5 PZ |
8081 | /* |
8082 | * If both events generate aux data, they must be on the same PMU | |
8083 | */ | |
8084 | if (has_aux(event) && has_aux(output_event) && | |
8085 | event->pmu != output_event->pmu) | |
8086 | goto out; | |
8087 | ||
a4be7c27 | 8088 | set: |
cdd6c482 | 8089 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8090 | /* Can't redirect output if we've got an active mmap() */ |
8091 | if (atomic_read(&event->mmap_count)) | |
8092 | goto unlock; | |
a4be7c27 | 8093 | |
ac9721f3 | 8094 | if (output_event) { |
76369139 FW |
8095 | /* get the rb we want to redirect to */ |
8096 | rb = ring_buffer_get(output_event); | |
8097 | if (!rb) | |
ac9721f3 | 8098 | goto unlock; |
a4be7c27 PZ |
8099 | } |
8100 | ||
b69cf536 | 8101 | ring_buffer_attach(event, rb); |
9bb5d40c | 8102 | |
a4be7c27 | 8103 | ret = 0; |
ac9721f3 PZ |
8104 | unlock: |
8105 | mutex_unlock(&event->mmap_mutex); | |
8106 | ||
a4be7c27 | 8107 | out: |
a4be7c27 PZ |
8108 | return ret; |
8109 | } | |
8110 | ||
f63a8daa PZ |
8111 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8112 | { | |
8113 | if (b < a) | |
8114 | swap(a, b); | |
8115 | ||
8116 | mutex_lock(a); | |
8117 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8118 | } | |
8119 | ||
34f43927 PZ |
8120 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8121 | { | |
8122 | bool nmi_safe = false; | |
8123 | ||
8124 | switch (clk_id) { | |
8125 | case CLOCK_MONOTONIC: | |
8126 | event->clock = &ktime_get_mono_fast_ns; | |
8127 | nmi_safe = true; | |
8128 | break; | |
8129 | ||
8130 | case CLOCK_MONOTONIC_RAW: | |
8131 | event->clock = &ktime_get_raw_fast_ns; | |
8132 | nmi_safe = true; | |
8133 | break; | |
8134 | ||
8135 | case CLOCK_REALTIME: | |
8136 | event->clock = &ktime_get_real_ns; | |
8137 | break; | |
8138 | ||
8139 | case CLOCK_BOOTTIME: | |
8140 | event->clock = &ktime_get_boot_ns; | |
8141 | break; | |
8142 | ||
8143 | case CLOCK_TAI: | |
8144 | event->clock = &ktime_get_tai_ns; | |
8145 | break; | |
8146 | ||
8147 | default: | |
8148 | return -EINVAL; | |
8149 | } | |
8150 | ||
8151 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8152 | return -EINVAL; | |
8153 | ||
8154 | return 0; | |
8155 | } | |
8156 | ||
0793a61d | 8157 | /** |
cdd6c482 | 8158 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8159 | * |
cdd6c482 | 8160 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8161 | * @pid: target pid |
9f66a381 | 8162 | * @cpu: target cpu |
cdd6c482 | 8163 | * @group_fd: group leader event fd |
0793a61d | 8164 | */ |
cdd6c482 IM |
8165 | SYSCALL_DEFINE5(perf_event_open, |
8166 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8167 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8168 | { |
b04243ef PZ |
8169 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8170 | struct perf_event *event, *sibling; | |
cdd6c482 | 8171 | struct perf_event_attr attr; |
f63a8daa | 8172 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8173 | struct file *event_file = NULL; |
2903ff01 | 8174 | struct fd group = {NULL, 0}; |
38a81da2 | 8175 | struct task_struct *task = NULL; |
89a1e187 | 8176 | struct pmu *pmu; |
ea635c64 | 8177 | int event_fd; |
b04243ef | 8178 | int move_group = 0; |
dc86cabe | 8179 | int err; |
a21b0b35 | 8180 | int f_flags = O_RDWR; |
79dff51e | 8181 | int cgroup_fd = -1; |
0793a61d | 8182 | |
2743a5b0 | 8183 | /* for future expandability... */ |
e5d1367f | 8184 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8185 | return -EINVAL; |
8186 | ||
dc86cabe IM |
8187 | err = perf_copy_attr(attr_uptr, &attr); |
8188 | if (err) | |
8189 | return err; | |
eab656ae | 8190 | |
0764771d PZ |
8191 | if (!attr.exclude_kernel) { |
8192 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8193 | return -EACCES; | |
8194 | } | |
8195 | ||
df58ab24 | 8196 | if (attr.freq) { |
cdd6c482 | 8197 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8198 | return -EINVAL; |
0819b2e3 PZ |
8199 | } else { |
8200 | if (attr.sample_period & (1ULL << 63)) | |
8201 | return -EINVAL; | |
df58ab24 PZ |
8202 | } |
8203 | ||
e5d1367f SE |
8204 | /* |
8205 | * In cgroup mode, the pid argument is used to pass the fd | |
8206 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8207 | * designates the cpu on which to monitor threads from that | |
8208 | * cgroup. | |
8209 | */ | |
8210 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8211 | return -EINVAL; | |
8212 | ||
a21b0b35 YD |
8213 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8214 | f_flags |= O_CLOEXEC; | |
8215 | ||
8216 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8217 | if (event_fd < 0) |
8218 | return event_fd; | |
8219 | ||
ac9721f3 | 8220 | if (group_fd != -1) { |
2903ff01 AV |
8221 | err = perf_fget_light(group_fd, &group); |
8222 | if (err) | |
d14b12d7 | 8223 | goto err_fd; |
2903ff01 | 8224 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8225 | if (flags & PERF_FLAG_FD_OUTPUT) |
8226 | output_event = group_leader; | |
8227 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8228 | group_leader = NULL; | |
8229 | } | |
8230 | ||
e5d1367f | 8231 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8232 | task = find_lively_task_by_vpid(pid); |
8233 | if (IS_ERR(task)) { | |
8234 | err = PTR_ERR(task); | |
8235 | goto err_group_fd; | |
8236 | } | |
8237 | } | |
8238 | ||
1f4ee503 PZ |
8239 | if (task && group_leader && |
8240 | group_leader->attr.inherit != attr.inherit) { | |
8241 | err = -EINVAL; | |
8242 | goto err_task; | |
8243 | } | |
8244 | ||
fbfc623f YZ |
8245 | get_online_cpus(); |
8246 | ||
79dff51e MF |
8247 | if (flags & PERF_FLAG_PID_CGROUP) |
8248 | cgroup_fd = pid; | |
8249 | ||
4dc0da86 | 8250 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8251 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8252 | if (IS_ERR(event)) { |
8253 | err = PTR_ERR(event); | |
1f4ee503 | 8254 | goto err_cpus; |
d14b12d7 SE |
8255 | } |
8256 | ||
53b25335 VW |
8257 | if (is_sampling_event(event)) { |
8258 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8259 | err = -ENOTSUPP; | |
8260 | goto err_alloc; | |
8261 | } | |
8262 | } | |
8263 | ||
766d6c07 FW |
8264 | account_event(event); |
8265 | ||
89a1e187 PZ |
8266 | /* |
8267 | * Special case software events and allow them to be part of | |
8268 | * any hardware group. | |
8269 | */ | |
8270 | pmu = event->pmu; | |
b04243ef | 8271 | |
34f43927 PZ |
8272 | if (attr.use_clockid) { |
8273 | err = perf_event_set_clock(event, attr.clockid); | |
8274 | if (err) | |
8275 | goto err_alloc; | |
8276 | } | |
8277 | ||
b04243ef PZ |
8278 | if (group_leader && |
8279 | (is_software_event(event) != is_software_event(group_leader))) { | |
8280 | if (is_software_event(event)) { | |
8281 | /* | |
8282 | * If event and group_leader are not both a software | |
8283 | * event, and event is, then group leader is not. | |
8284 | * | |
8285 | * Allow the addition of software events to !software | |
8286 | * groups, this is safe because software events never | |
8287 | * fail to schedule. | |
8288 | */ | |
8289 | pmu = group_leader->pmu; | |
8290 | } else if (is_software_event(group_leader) && | |
8291 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8292 | /* | |
8293 | * In case the group is a pure software group, and we | |
8294 | * try to add a hardware event, move the whole group to | |
8295 | * the hardware context. | |
8296 | */ | |
8297 | move_group = 1; | |
8298 | } | |
8299 | } | |
89a1e187 PZ |
8300 | |
8301 | /* | |
8302 | * Get the target context (task or percpu): | |
8303 | */ | |
4af57ef2 | 8304 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8305 | if (IS_ERR(ctx)) { |
8306 | err = PTR_ERR(ctx); | |
c6be5a5c | 8307 | goto err_alloc; |
89a1e187 PZ |
8308 | } |
8309 | ||
bed5b25a AS |
8310 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8311 | err = -EBUSY; | |
8312 | goto err_context; | |
8313 | } | |
8314 | ||
fd1edb3a PZ |
8315 | if (task) { |
8316 | put_task_struct(task); | |
8317 | task = NULL; | |
8318 | } | |
8319 | ||
ccff286d | 8320 | /* |
cdd6c482 | 8321 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8322 | */ |
ac9721f3 | 8323 | if (group_leader) { |
dc86cabe | 8324 | err = -EINVAL; |
04289bb9 | 8325 | |
04289bb9 | 8326 | /* |
ccff286d IM |
8327 | * Do not allow a recursive hierarchy (this new sibling |
8328 | * becoming part of another group-sibling): | |
8329 | */ | |
8330 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8331 | goto err_context; |
34f43927 PZ |
8332 | |
8333 | /* All events in a group should have the same clock */ | |
8334 | if (group_leader->clock != event->clock) | |
8335 | goto err_context; | |
8336 | ||
ccff286d IM |
8337 | /* |
8338 | * Do not allow to attach to a group in a different | |
8339 | * task or CPU context: | |
04289bb9 | 8340 | */ |
b04243ef | 8341 | if (move_group) { |
c3c87e77 PZ |
8342 | /* |
8343 | * Make sure we're both on the same task, or both | |
8344 | * per-cpu events. | |
8345 | */ | |
8346 | if (group_leader->ctx->task != ctx->task) | |
8347 | goto err_context; | |
8348 | ||
8349 | /* | |
8350 | * Make sure we're both events for the same CPU; | |
8351 | * grouping events for different CPUs is broken; since | |
8352 | * you can never concurrently schedule them anyhow. | |
8353 | */ | |
8354 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8355 | goto err_context; |
8356 | } else { | |
8357 | if (group_leader->ctx != ctx) | |
8358 | goto err_context; | |
8359 | } | |
8360 | ||
3b6f9e5c PM |
8361 | /* |
8362 | * Only a group leader can be exclusive or pinned | |
8363 | */ | |
0d48696f | 8364 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8365 | goto err_context; |
ac9721f3 PZ |
8366 | } |
8367 | ||
8368 | if (output_event) { | |
8369 | err = perf_event_set_output(event, output_event); | |
8370 | if (err) | |
c3f00c70 | 8371 | goto err_context; |
ac9721f3 | 8372 | } |
0793a61d | 8373 | |
a21b0b35 YD |
8374 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8375 | f_flags); | |
ea635c64 AV |
8376 | if (IS_ERR(event_file)) { |
8377 | err = PTR_ERR(event_file); | |
c3f00c70 | 8378 | goto err_context; |
ea635c64 | 8379 | } |
9b51f66d | 8380 | |
b04243ef | 8381 | if (move_group) { |
f63a8daa | 8382 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8383 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8384 | } else { | |
8385 | mutex_lock(&ctx->mutex); | |
8386 | } | |
8387 | ||
a723968c PZ |
8388 | if (!perf_event_validate_size(event)) { |
8389 | err = -E2BIG; | |
8390 | goto err_locked; | |
8391 | } | |
8392 | ||
f55fc2a5 PZ |
8393 | /* |
8394 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8395 | * because we need to serialize with concurrent event creation. | |
8396 | */ | |
8397 | if (!exclusive_event_installable(event, ctx)) { | |
8398 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8399 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8400 | |
f55fc2a5 PZ |
8401 | err = -EBUSY; |
8402 | goto err_locked; | |
8403 | } | |
f63a8daa | 8404 | |
f55fc2a5 PZ |
8405 | WARN_ON_ONCE(ctx->parent_ctx); |
8406 | ||
8407 | if (move_group) { | |
f63a8daa PZ |
8408 | /* |
8409 | * See perf_event_ctx_lock() for comments on the details | |
8410 | * of swizzling perf_event::ctx. | |
8411 | */ | |
46ce0fe9 | 8412 | perf_remove_from_context(group_leader, false); |
0231bb53 | 8413 | |
b04243ef PZ |
8414 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8415 | group_entry) { | |
46ce0fe9 | 8416 | perf_remove_from_context(sibling, false); |
b04243ef PZ |
8417 | put_ctx(gctx); |
8418 | } | |
b04243ef | 8419 | |
f63a8daa PZ |
8420 | /* |
8421 | * Wait for everybody to stop referencing the events through | |
8422 | * the old lists, before installing it on new lists. | |
8423 | */ | |
0cda4c02 | 8424 | synchronize_rcu(); |
f63a8daa | 8425 | |
8f95b435 PZI |
8426 | /* |
8427 | * Install the group siblings before the group leader. | |
8428 | * | |
8429 | * Because a group leader will try and install the entire group | |
8430 | * (through the sibling list, which is still in-tact), we can | |
8431 | * end up with siblings installed in the wrong context. | |
8432 | * | |
8433 | * By installing siblings first we NO-OP because they're not | |
8434 | * reachable through the group lists. | |
8435 | */ | |
b04243ef PZ |
8436 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8437 | group_entry) { | |
8f95b435 | 8438 | perf_event__state_init(sibling); |
9fc81d87 | 8439 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8440 | get_ctx(ctx); |
8441 | } | |
8f95b435 PZI |
8442 | |
8443 | /* | |
8444 | * Removing from the context ends up with disabled | |
8445 | * event. What we want here is event in the initial | |
8446 | * startup state, ready to be add into new context. | |
8447 | */ | |
8448 | perf_event__state_init(group_leader); | |
8449 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8450 | get_ctx(ctx); | |
b04243ef | 8451 | |
f55fc2a5 PZ |
8452 | /* |
8453 | * Now that all events are installed in @ctx, nothing | |
8454 | * references @gctx anymore, so drop the last reference we have | |
8455 | * on it. | |
8456 | */ | |
8457 | put_ctx(gctx); | |
bed5b25a AS |
8458 | } |
8459 | ||
f73e22ab PZ |
8460 | /* |
8461 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8462 | * that we're serialized against further additions and before | |
8463 | * perf_install_in_context() which is the point the event is active and | |
8464 | * can use these values. | |
8465 | */ | |
8466 | perf_event__header_size(event); | |
8467 | perf_event__id_header_size(event); | |
8468 | ||
e2d37cd2 | 8469 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8470 | perf_unpin_context(ctx); |
f63a8daa | 8471 | |
f55fc2a5 | 8472 | if (move_group) |
f63a8daa | 8473 | mutex_unlock(&gctx->mutex); |
d859e29f | 8474 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8475 | |
fbfc623f YZ |
8476 | put_online_cpus(); |
8477 | ||
cdd6c482 | 8478 | event->owner = current; |
8882135b | 8479 | |
cdd6c482 IM |
8480 | mutex_lock(¤t->perf_event_mutex); |
8481 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8482 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8483 | |
8a49542c PZ |
8484 | /* |
8485 | * Drop the reference on the group_event after placing the | |
8486 | * new event on the sibling_list. This ensures destruction | |
8487 | * of the group leader will find the pointer to itself in | |
8488 | * perf_group_detach(). | |
8489 | */ | |
2903ff01 | 8490 | fdput(group); |
ea635c64 AV |
8491 | fd_install(event_fd, event_file); |
8492 | return event_fd; | |
0793a61d | 8493 | |
f55fc2a5 PZ |
8494 | err_locked: |
8495 | if (move_group) | |
8496 | mutex_unlock(&gctx->mutex); | |
8497 | mutex_unlock(&ctx->mutex); | |
8498 | /* err_file: */ | |
8499 | fput(event_file); | |
c3f00c70 | 8500 | err_context: |
fe4b04fa | 8501 | perf_unpin_context(ctx); |
ea635c64 | 8502 | put_ctx(ctx); |
c6be5a5c | 8503 | err_alloc: |
ea635c64 | 8504 | free_event(event); |
1f4ee503 | 8505 | err_cpus: |
fbfc623f | 8506 | put_online_cpus(); |
1f4ee503 | 8507 | err_task: |
e7d0bc04 PZ |
8508 | if (task) |
8509 | put_task_struct(task); | |
89a1e187 | 8510 | err_group_fd: |
2903ff01 | 8511 | fdput(group); |
ea635c64 AV |
8512 | err_fd: |
8513 | put_unused_fd(event_fd); | |
dc86cabe | 8514 | return err; |
0793a61d TG |
8515 | } |
8516 | ||
fb0459d7 AV |
8517 | /** |
8518 | * perf_event_create_kernel_counter | |
8519 | * | |
8520 | * @attr: attributes of the counter to create | |
8521 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8522 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8523 | */ |
8524 | struct perf_event * | |
8525 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8526 | struct task_struct *task, |
4dc0da86 AK |
8527 | perf_overflow_handler_t overflow_handler, |
8528 | void *context) | |
fb0459d7 | 8529 | { |
fb0459d7 | 8530 | struct perf_event_context *ctx; |
c3f00c70 | 8531 | struct perf_event *event; |
fb0459d7 | 8532 | int err; |
d859e29f | 8533 | |
fb0459d7 AV |
8534 | /* |
8535 | * Get the target context (task or percpu): | |
8536 | */ | |
d859e29f | 8537 | |
4dc0da86 | 8538 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8539 | overflow_handler, context, -1); |
c3f00c70 PZ |
8540 | if (IS_ERR(event)) { |
8541 | err = PTR_ERR(event); | |
8542 | goto err; | |
8543 | } | |
d859e29f | 8544 | |
f8697762 JO |
8545 | /* Mark owner so we could distinguish it from user events. */ |
8546 | event->owner = EVENT_OWNER_KERNEL; | |
8547 | ||
766d6c07 FW |
8548 | account_event(event); |
8549 | ||
4af57ef2 | 8550 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8551 | if (IS_ERR(ctx)) { |
8552 | err = PTR_ERR(ctx); | |
c3f00c70 | 8553 | goto err_free; |
d859e29f | 8554 | } |
fb0459d7 | 8555 | |
fb0459d7 AV |
8556 | WARN_ON_ONCE(ctx->parent_ctx); |
8557 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8558 | if (!exclusive_event_installable(event, ctx)) { |
8559 | mutex_unlock(&ctx->mutex); | |
8560 | perf_unpin_context(ctx); | |
8561 | put_ctx(ctx); | |
8562 | err = -EBUSY; | |
8563 | goto err_free; | |
8564 | } | |
8565 | ||
fb0459d7 | 8566 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8567 | perf_unpin_context(ctx); |
fb0459d7 AV |
8568 | mutex_unlock(&ctx->mutex); |
8569 | ||
fb0459d7 AV |
8570 | return event; |
8571 | ||
c3f00c70 PZ |
8572 | err_free: |
8573 | free_event(event); | |
8574 | err: | |
c6567f64 | 8575 | return ERR_PTR(err); |
9b51f66d | 8576 | } |
fb0459d7 | 8577 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8578 | |
0cda4c02 YZ |
8579 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8580 | { | |
8581 | struct perf_event_context *src_ctx; | |
8582 | struct perf_event_context *dst_ctx; | |
8583 | struct perf_event *event, *tmp; | |
8584 | LIST_HEAD(events); | |
8585 | ||
8586 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8587 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8588 | ||
f63a8daa PZ |
8589 | /* |
8590 | * See perf_event_ctx_lock() for comments on the details | |
8591 | * of swizzling perf_event::ctx. | |
8592 | */ | |
8593 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8594 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8595 | event_entry) { | |
46ce0fe9 | 8596 | perf_remove_from_context(event, false); |
9a545de0 | 8597 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8598 | put_ctx(src_ctx); |
9886167d | 8599 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8600 | } |
0cda4c02 | 8601 | |
8f95b435 PZI |
8602 | /* |
8603 | * Wait for the events to quiesce before re-instating them. | |
8604 | */ | |
0cda4c02 YZ |
8605 | synchronize_rcu(); |
8606 | ||
8f95b435 PZI |
8607 | /* |
8608 | * Re-instate events in 2 passes. | |
8609 | * | |
8610 | * Skip over group leaders and only install siblings on this first | |
8611 | * pass, siblings will not get enabled without a leader, however a | |
8612 | * leader will enable its siblings, even if those are still on the old | |
8613 | * context. | |
8614 | */ | |
8615 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8616 | if (event->group_leader == event) | |
8617 | continue; | |
8618 | ||
8619 | list_del(&event->migrate_entry); | |
8620 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8621 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8622 | account_event_cpu(event, dst_cpu); | |
8623 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8624 | get_ctx(dst_ctx); | |
8625 | } | |
8626 | ||
8627 | /* | |
8628 | * Once all the siblings are setup properly, install the group leaders | |
8629 | * to make it go. | |
8630 | */ | |
9886167d PZ |
8631 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8632 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8633 | if (event->state >= PERF_EVENT_STATE_OFF) |
8634 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8635 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8636 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8637 | get_ctx(dst_ctx); | |
8638 | } | |
8639 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8640 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8641 | } |
8642 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8643 | ||
cdd6c482 | 8644 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8645 | struct task_struct *child) |
d859e29f | 8646 | { |
cdd6c482 | 8647 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8648 | u64 child_val; |
d859e29f | 8649 | |
cdd6c482 IM |
8650 | if (child_event->attr.inherit_stat) |
8651 | perf_event_read_event(child_event, child); | |
38b200d6 | 8652 | |
b5e58793 | 8653 | child_val = perf_event_count(child_event); |
d859e29f PM |
8654 | |
8655 | /* | |
8656 | * Add back the child's count to the parent's count: | |
8657 | */ | |
a6e6dea6 | 8658 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8659 | atomic64_add(child_event->total_time_enabled, |
8660 | &parent_event->child_total_time_enabled); | |
8661 | atomic64_add(child_event->total_time_running, | |
8662 | &parent_event->child_total_time_running); | |
d859e29f PM |
8663 | |
8664 | /* | |
cdd6c482 | 8665 | * Remove this event from the parent's list |
d859e29f | 8666 | */ |
cdd6c482 IM |
8667 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
8668 | mutex_lock(&parent_event->child_mutex); | |
8669 | list_del_init(&child_event->child_list); | |
8670 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f | 8671 | |
dc633982 JO |
8672 | /* |
8673 | * Make sure user/parent get notified, that we just | |
8674 | * lost one event. | |
8675 | */ | |
8676 | perf_event_wakeup(parent_event); | |
8677 | ||
d859e29f | 8678 | /* |
cdd6c482 | 8679 | * Release the parent event, if this was the last |
d859e29f PM |
8680 | * reference to it. |
8681 | */ | |
a6fa941d | 8682 | put_event(parent_event); |
d859e29f PM |
8683 | } |
8684 | ||
9b51f66d | 8685 | static void |
cdd6c482 IM |
8686 | __perf_event_exit_task(struct perf_event *child_event, |
8687 | struct perf_event_context *child_ctx, | |
38b200d6 | 8688 | struct task_struct *child) |
9b51f66d | 8689 | { |
1903d50c PZ |
8690 | /* |
8691 | * Do not destroy the 'original' grouping; because of the context | |
8692 | * switch optimization the original events could've ended up in a | |
8693 | * random child task. | |
8694 | * | |
8695 | * If we were to destroy the original group, all group related | |
8696 | * operations would cease to function properly after this random | |
8697 | * child dies. | |
8698 | * | |
8699 | * Do destroy all inherited groups, we don't care about those | |
8700 | * and being thorough is better. | |
8701 | */ | |
8702 | perf_remove_from_context(child_event, !!child_event->parent); | |
0cc0c027 | 8703 | |
9b51f66d | 8704 | /* |
38b435b1 | 8705 | * It can happen that the parent exits first, and has events |
9b51f66d | 8706 | * that are still around due to the child reference. These |
38b435b1 | 8707 | * events need to be zapped. |
9b51f66d | 8708 | */ |
38b435b1 | 8709 | if (child_event->parent) { |
cdd6c482 IM |
8710 | sync_child_event(child_event, child); |
8711 | free_event(child_event); | |
179033b3 JO |
8712 | } else { |
8713 | child_event->state = PERF_EVENT_STATE_EXIT; | |
8714 | perf_event_wakeup(child_event); | |
4bcf349a | 8715 | } |
9b51f66d IM |
8716 | } |
8717 | ||
8dc85d54 | 8718 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8719 | { |
ebf905fc | 8720 | struct perf_event *child_event, *next; |
211de6eb | 8721 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
a63eaf34 | 8722 | unsigned long flags; |
9b51f66d | 8723 | |
4e93ad60 | 8724 | if (likely(!child->perf_event_ctxp[ctxn])) |
9b51f66d IM |
8725 | return; |
8726 | ||
a63eaf34 | 8727 | local_irq_save(flags); |
ad3a37de PM |
8728 | /* |
8729 | * We can't reschedule here because interrupts are disabled, | |
8730 | * and either child is current or it is a task that can't be | |
8731 | * scheduled, so we are now safe from rescheduling changing | |
8732 | * our context. | |
8733 | */ | |
806839b2 | 8734 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
8735 | |
8736 | /* | |
8737 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 8738 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
8739 | * incremented the context's refcount before we do put_ctx below. |
8740 | */ | |
e625cce1 | 8741 | raw_spin_lock(&child_ctx->lock); |
3e349507 | 8742 | task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx); |
8dc85d54 | 8743 | child->perf_event_ctxp[ctxn] = NULL; |
4a1c0f26 | 8744 | |
71a851b4 PZ |
8745 | /* |
8746 | * If this context is a clone; unclone it so it can't get | |
8747 | * swapped to another process while we're removing all | |
cdd6c482 | 8748 | * the events from it. |
71a851b4 | 8749 | */ |
211de6eb | 8750 | clone_ctx = unclone_ctx(child_ctx); |
5e942bb3 | 8751 | update_context_time(child_ctx); |
e625cce1 | 8752 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
9f498cc5 | 8753 | |
211de6eb PZ |
8754 | if (clone_ctx) |
8755 | put_ctx(clone_ctx); | |
4a1c0f26 | 8756 | |
9f498cc5 | 8757 | /* |
cdd6c482 IM |
8758 | * Report the task dead after unscheduling the events so that we |
8759 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8760 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8761 | */ |
cdd6c482 | 8762 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8763 | |
66fff224 PZ |
8764 | /* |
8765 | * We can recurse on the same lock type through: | |
8766 | * | |
cdd6c482 IM |
8767 | * __perf_event_exit_task() |
8768 | * sync_child_event() | |
a6fa941d AV |
8769 | * put_event() |
8770 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
8771 | * |
8772 | * But since its the parent context it won't be the same instance. | |
8773 | */ | |
a0507c84 | 8774 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 8775 | |
ebf905fc | 8776 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
cdd6c482 | 8777 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 | 8778 | |
a63eaf34 PM |
8779 | mutex_unlock(&child_ctx->mutex); |
8780 | ||
8781 | put_ctx(child_ctx); | |
9b51f66d IM |
8782 | } |
8783 | ||
8dc85d54 PZ |
8784 | /* |
8785 | * When a child task exits, feed back event values to parent events. | |
8786 | */ | |
8787 | void perf_event_exit_task(struct task_struct *child) | |
8788 | { | |
8882135b | 8789 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8790 | int ctxn; |
8791 | ||
8882135b PZ |
8792 | mutex_lock(&child->perf_event_mutex); |
8793 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8794 | owner_entry) { | |
8795 | list_del_init(&event->owner_entry); | |
8796 | ||
8797 | /* | |
8798 | * Ensure the list deletion is visible before we clear | |
8799 | * the owner, closes a race against perf_release() where | |
8800 | * we need to serialize on the owner->perf_event_mutex. | |
8801 | */ | |
8802 | smp_wmb(); | |
8803 | event->owner = NULL; | |
8804 | } | |
8805 | mutex_unlock(&child->perf_event_mutex); | |
8806 | ||
8dc85d54 PZ |
8807 | for_each_task_context_nr(ctxn) |
8808 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8809 | |
8810 | /* | |
8811 | * The perf_event_exit_task_context calls perf_event_task | |
8812 | * with child's task_ctx, which generates EXIT events for | |
8813 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8814 | * At this point we need to send EXIT events to cpu contexts. | |
8815 | */ | |
8816 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8817 | } |
8818 | ||
889ff015 FW |
8819 | static void perf_free_event(struct perf_event *event, |
8820 | struct perf_event_context *ctx) | |
8821 | { | |
8822 | struct perf_event *parent = event->parent; | |
8823 | ||
8824 | if (WARN_ON_ONCE(!parent)) | |
8825 | return; | |
8826 | ||
8827 | mutex_lock(&parent->child_mutex); | |
8828 | list_del_init(&event->child_list); | |
8829 | mutex_unlock(&parent->child_mutex); | |
8830 | ||
a6fa941d | 8831 | put_event(parent); |
889ff015 | 8832 | |
652884fe | 8833 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8834 | perf_group_detach(event); |
889ff015 | 8835 | list_del_event(event, ctx); |
652884fe | 8836 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8837 | free_event(event); |
8838 | } | |
8839 | ||
bbbee908 | 8840 | /* |
652884fe | 8841 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8842 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8843 | * |
8844 | * Not all locks are strictly required, but take them anyway to be nice and | |
8845 | * help out with the lockdep assertions. | |
bbbee908 | 8846 | */ |
cdd6c482 | 8847 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8848 | { |
8dc85d54 | 8849 | struct perf_event_context *ctx; |
cdd6c482 | 8850 | struct perf_event *event, *tmp; |
8dc85d54 | 8851 | int ctxn; |
bbbee908 | 8852 | |
8dc85d54 PZ |
8853 | for_each_task_context_nr(ctxn) { |
8854 | ctx = task->perf_event_ctxp[ctxn]; | |
8855 | if (!ctx) | |
8856 | continue; | |
bbbee908 | 8857 | |
8dc85d54 | 8858 | mutex_lock(&ctx->mutex); |
bbbee908 | 8859 | again: |
8dc85d54 PZ |
8860 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8861 | group_entry) | |
8862 | perf_free_event(event, ctx); | |
bbbee908 | 8863 | |
8dc85d54 PZ |
8864 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8865 | group_entry) | |
8866 | perf_free_event(event, ctx); | |
bbbee908 | 8867 | |
8dc85d54 PZ |
8868 | if (!list_empty(&ctx->pinned_groups) || |
8869 | !list_empty(&ctx->flexible_groups)) | |
8870 | goto again; | |
bbbee908 | 8871 | |
8dc85d54 | 8872 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8873 | |
8dc85d54 PZ |
8874 | put_ctx(ctx); |
8875 | } | |
889ff015 FW |
8876 | } |
8877 | ||
4e231c79 PZ |
8878 | void perf_event_delayed_put(struct task_struct *task) |
8879 | { | |
8880 | int ctxn; | |
8881 | ||
8882 | for_each_task_context_nr(ctxn) | |
8883 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8884 | } | |
8885 | ||
ffe8690c KX |
8886 | struct perf_event *perf_event_get(unsigned int fd) |
8887 | { | |
8888 | int err; | |
8889 | struct fd f; | |
8890 | struct perf_event *event; | |
8891 | ||
8892 | err = perf_fget_light(fd, &f); | |
8893 | if (err) | |
8894 | return ERR_PTR(err); | |
8895 | ||
8896 | event = f.file->private_data; | |
8897 | atomic_long_inc(&event->refcount); | |
8898 | fdput(f); | |
8899 | ||
8900 | return event; | |
8901 | } | |
8902 | ||
8903 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8904 | { | |
8905 | if (!event) | |
8906 | return ERR_PTR(-EINVAL); | |
8907 | ||
8908 | return &event->attr; | |
8909 | } | |
8910 | ||
97dee4f3 PZ |
8911 | /* |
8912 | * inherit a event from parent task to child task: | |
8913 | */ | |
8914 | static struct perf_event * | |
8915 | inherit_event(struct perf_event *parent_event, | |
8916 | struct task_struct *parent, | |
8917 | struct perf_event_context *parent_ctx, | |
8918 | struct task_struct *child, | |
8919 | struct perf_event *group_leader, | |
8920 | struct perf_event_context *child_ctx) | |
8921 | { | |
1929def9 | 8922 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8923 | struct perf_event *child_event; |
cee010ec | 8924 | unsigned long flags; |
97dee4f3 PZ |
8925 | |
8926 | /* | |
8927 | * Instead of creating recursive hierarchies of events, | |
8928 | * we link inherited events back to the original parent, | |
8929 | * which has a filp for sure, which we use as the reference | |
8930 | * count: | |
8931 | */ | |
8932 | if (parent_event->parent) | |
8933 | parent_event = parent_event->parent; | |
8934 | ||
8935 | child_event = perf_event_alloc(&parent_event->attr, | |
8936 | parent_event->cpu, | |
d580ff86 | 8937 | child, |
97dee4f3 | 8938 | group_leader, parent_event, |
79dff51e | 8939 | NULL, NULL, -1); |
97dee4f3 PZ |
8940 | if (IS_ERR(child_event)) |
8941 | return child_event; | |
a6fa941d | 8942 | |
fadfe7be JO |
8943 | if (is_orphaned_event(parent_event) || |
8944 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
a6fa941d AV |
8945 | free_event(child_event); |
8946 | return NULL; | |
8947 | } | |
8948 | ||
97dee4f3 PZ |
8949 | get_ctx(child_ctx); |
8950 | ||
8951 | /* | |
8952 | * Make the child state follow the state of the parent event, | |
8953 | * not its attr.disabled bit. We hold the parent's mutex, | |
8954 | * so we won't race with perf_event_{en, dis}able_family. | |
8955 | */ | |
1929def9 | 8956 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8957 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8958 | else | |
8959 | child_event->state = PERF_EVENT_STATE_OFF; | |
8960 | ||
8961 | if (parent_event->attr.freq) { | |
8962 | u64 sample_period = parent_event->hw.sample_period; | |
8963 | struct hw_perf_event *hwc = &child_event->hw; | |
8964 | ||
8965 | hwc->sample_period = sample_period; | |
8966 | hwc->last_period = sample_period; | |
8967 | ||
8968 | local64_set(&hwc->period_left, sample_period); | |
8969 | } | |
8970 | ||
8971 | child_event->ctx = child_ctx; | |
8972 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
8973 | child_event->overflow_handler_context |
8974 | = parent_event->overflow_handler_context; | |
97dee4f3 | 8975 | |
614b6780 TG |
8976 | /* |
8977 | * Precalculate sample_data sizes | |
8978 | */ | |
8979 | perf_event__header_size(child_event); | |
6844c09d | 8980 | perf_event__id_header_size(child_event); |
614b6780 | 8981 | |
97dee4f3 PZ |
8982 | /* |
8983 | * Link it up in the child's context: | |
8984 | */ | |
cee010ec | 8985 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 8986 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 8987 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 8988 | |
97dee4f3 PZ |
8989 | /* |
8990 | * Link this into the parent event's child list | |
8991 | */ | |
8992 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
8993 | mutex_lock(&parent_event->child_mutex); | |
8994 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
8995 | mutex_unlock(&parent_event->child_mutex); | |
8996 | ||
8997 | return child_event; | |
8998 | } | |
8999 | ||
9000 | static int inherit_group(struct perf_event *parent_event, | |
9001 | struct task_struct *parent, | |
9002 | struct perf_event_context *parent_ctx, | |
9003 | struct task_struct *child, | |
9004 | struct perf_event_context *child_ctx) | |
9005 | { | |
9006 | struct perf_event *leader; | |
9007 | struct perf_event *sub; | |
9008 | struct perf_event *child_ctr; | |
9009 | ||
9010 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9011 | child, NULL, child_ctx); | |
9012 | if (IS_ERR(leader)) | |
9013 | return PTR_ERR(leader); | |
9014 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9015 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9016 | child, leader, child_ctx); | |
9017 | if (IS_ERR(child_ctr)) | |
9018 | return PTR_ERR(child_ctr); | |
9019 | } | |
9020 | return 0; | |
889ff015 FW |
9021 | } |
9022 | ||
9023 | static int | |
9024 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9025 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9026 | struct task_struct *child, int ctxn, |
889ff015 FW |
9027 | int *inherited_all) |
9028 | { | |
9029 | int ret; | |
8dc85d54 | 9030 | struct perf_event_context *child_ctx; |
889ff015 FW |
9031 | |
9032 | if (!event->attr.inherit) { | |
9033 | *inherited_all = 0; | |
9034 | return 0; | |
bbbee908 PZ |
9035 | } |
9036 | ||
fe4b04fa | 9037 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9038 | if (!child_ctx) { |
9039 | /* | |
9040 | * This is executed from the parent task context, so | |
9041 | * inherit events that have been marked for cloning. | |
9042 | * First allocate and initialize a context for the | |
9043 | * child. | |
9044 | */ | |
bbbee908 | 9045 | |
734df5ab | 9046 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9047 | if (!child_ctx) |
9048 | return -ENOMEM; | |
bbbee908 | 9049 | |
8dc85d54 | 9050 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9051 | } |
9052 | ||
9053 | ret = inherit_group(event, parent, parent_ctx, | |
9054 | child, child_ctx); | |
9055 | ||
9056 | if (ret) | |
9057 | *inherited_all = 0; | |
9058 | ||
9059 | return ret; | |
bbbee908 PZ |
9060 | } |
9061 | ||
9b51f66d | 9062 | /* |
cdd6c482 | 9063 | * Initialize the perf_event context in task_struct |
9b51f66d | 9064 | */ |
985c8dcb | 9065 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9066 | { |
889ff015 | 9067 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9068 | struct perf_event_context *cloned_ctx; |
9069 | struct perf_event *event; | |
9b51f66d | 9070 | struct task_struct *parent = current; |
564c2b21 | 9071 | int inherited_all = 1; |
dddd3379 | 9072 | unsigned long flags; |
6ab423e0 | 9073 | int ret = 0; |
9b51f66d | 9074 | |
8dc85d54 | 9075 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9076 | return 0; |
9077 | ||
ad3a37de | 9078 | /* |
25346b93 PM |
9079 | * If the parent's context is a clone, pin it so it won't get |
9080 | * swapped under us. | |
ad3a37de | 9081 | */ |
8dc85d54 | 9082 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9083 | if (!parent_ctx) |
9084 | return 0; | |
25346b93 | 9085 | |
ad3a37de PM |
9086 | /* |
9087 | * No need to check if parent_ctx != NULL here; since we saw | |
9088 | * it non-NULL earlier, the only reason for it to become NULL | |
9089 | * is if we exit, and since we're currently in the middle of | |
9090 | * a fork we can't be exiting at the same time. | |
9091 | */ | |
ad3a37de | 9092 | |
9b51f66d IM |
9093 | /* |
9094 | * Lock the parent list. No need to lock the child - not PID | |
9095 | * hashed yet and not running, so nobody can access it. | |
9096 | */ | |
d859e29f | 9097 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9098 | |
9099 | /* | |
9100 | * We dont have to disable NMIs - we are only looking at | |
9101 | * the list, not manipulating it: | |
9102 | */ | |
889ff015 | 9103 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9104 | ret = inherit_task_group(event, parent, parent_ctx, |
9105 | child, ctxn, &inherited_all); | |
889ff015 FW |
9106 | if (ret) |
9107 | break; | |
9108 | } | |
b93f7978 | 9109 | |
dddd3379 TG |
9110 | /* |
9111 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9112 | * to allocations, but we need to prevent rotation because | |
9113 | * rotate_ctx() will change the list from interrupt context. | |
9114 | */ | |
9115 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9116 | parent_ctx->rotate_disable = 1; | |
9117 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9118 | ||
889ff015 | 9119 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9120 | ret = inherit_task_group(event, parent, parent_ctx, |
9121 | child, ctxn, &inherited_all); | |
889ff015 | 9122 | if (ret) |
9b51f66d | 9123 | break; |
564c2b21 PM |
9124 | } |
9125 | ||
dddd3379 TG |
9126 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9127 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9128 | |
8dc85d54 | 9129 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9130 | |
05cbaa28 | 9131 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9132 | /* |
9133 | * Mark the child context as a clone of the parent | |
9134 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9135 | * |
9136 | * Note that if the parent is a clone, the holding of | |
9137 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9138 | */ |
c5ed5145 | 9139 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9140 | if (cloned_ctx) { |
9141 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9142 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9143 | } else { |
9144 | child_ctx->parent_ctx = parent_ctx; | |
9145 | child_ctx->parent_gen = parent_ctx->generation; | |
9146 | } | |
9147 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9148 | } |
9149 | ||
c5ed5145 | 9150 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9151 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9152 | |
25346b93 | 9153 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9154 | put_ctx(parent_ctx); |
ad3a37de | 9155 | |
6ab423e0 | 9156 | return ret; |
9b51f66d IM |
9157 | } |
9158 | ||
8dc85d54 PZ |
9159 | /* |
9160 | * Initialize the perf_event context in task_struct | |
9161 | */ | |
9162 | int perf_event_init_task(struct task_struct *child) | |
9163 | { | |
9164 | int ctxn, ret; | |
9165 | ||
8550d7cb ON |
9166 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9167 | mutex_init(&child->perf_event_mutex); | |
9168 | INIT_LIST_HEAD(&child->perf_event_list); | |
9169 | ||
8dc85d54 PZ |
9170 | for_each_task_context_nr(ctxn) { |
9171 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9172 | if (ret) { |
9173 | perf_event_free_task(child); | |
8dc85d54 | 9174 | return ret; |
6c72e350 | 9175 | } |
8dc85d54 PZ |
9176 | } |
9177 | ||
9178 | return 0; | |
9179 | } | |
9180 | ||
220b140b PM |
9181 | static void __init perf_event_init_all_cpus(void) |
9182 | { | |
b28ab83c | 9183 | struct swevent_htable *swhash; |
220b140b | 9184 | int cpu; |
220b140b PM |
9185 | |
9186 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9187 | swhash = &per_cpu(swevent_htable, cpu); |
9188 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9189 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9190 | } |
9191 | } | |
9192 | ||
0db0628d | 9193 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9194 | { |
108b02cf | 9195 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9196 | |
b28ab83c | 9197 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9198 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9199 | struct swevent_hlist *hlist; |
9200 | ||
b28ab83c PZ |
9201 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9202 | WARN_ON(!hlist); | |
9203 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9204 | } |
b28ab83c | 9205 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9206 | } |
9207 | ||
2965faa5 | 9208 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9209 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9210 | { |
226424ee | 9211 | struct remove_event re = { .detach_group = true }; |
108b02cf | 9212 | struct perf_event_context *ctx = __info; |
0793a61d | 9213 | |
e3703f8c | 9214 | rcu_read_lock(); |
46ce0fe9 PZ |
9215 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) |
9216 | __perf_remove_from_context(&re); | |
e3703f8c | 9217 | rcu_read_unlock(); |
0793a61d | 9218 | } |
108b02cf PZ |
9219 | |
9220 | static void perf_event_exit_cpu_context(int cpu) | |
9221 | { | |
9222 | struct perf_event_context *ctx; | |
9223 | struct pmu *pmu; | |
9224 | int idx; | |
9225 | ||
9226 | idx = srcu_read_lock(&pmus_srcu); | |
9227 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9228 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9229 | |
9230 | mutex_lock(&ctx->mutex); | |
9231 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9232 | mutex_unlock(&ctx->mutex); | |
9233 | } | |
9234 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9235 | } |
9236 | ||
cdd6c482 | 9237 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9238 | { |
e3703f8c | 9239 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9240 | } |
9241 | #else | |
cdd6c482 | 9242 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9243 | #endif |
9244 | ||
c277443c PZ |
9245 | static int |
9246 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9247 | { | |
9248 | int cpu; | |
9249 | ||
9250 | for_each_online_cpu(cpu) | |
9251 | perf_event_exit_cpu(cpu); | |
9252 | ||
9253 | return NOTIFY_OK; | |
9254 | } | |
9255 | ||
9256 | /* | |
9257 | * Run the perf reboot notifier at the very last possible moment so that | |
9258 | * the generic watchdog code runs as long as possible. | |
9259 | */ | |
9260 | static struct notifier_block perf_reboot_notifier = { | |
9261 | .notifier_call = perf_reboot, | |
9262 | .priority = INT_MIN, | |
9263 | }; | |
9264 | ||
0db0628d | 9265 | static int |
0793a61d TG |
9266 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9267 | { | |
9268 | unsigned int cpu = (long)hcpu; | |
9269 | ||
4536e4d1 | 9270 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9271 | |
9272 | case CPU_UP_PREPARE: | |
5e11637e | 9273 | case CPU_DOWN_FAILED: |
cdd6c482 | 9274 | perf_event_init_cpu(cpu); |
0793a61d TG |
9275 | break; |
9276 | ||
5e11637e | 9277 | case CPU_UP_CANCELED: |
0793a61d | 9278 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9279 | perf_event_exit_cpu(cpu); |
0793a61d | 9280 | break; |
0793a61d TG |
9281 | default: |
9282 | break; | |
9283 | } | |
9284 | ||
9285 | return NOTIFY_OK; | |
9286 | } | |
9287 | ||
cdd6c482 | 9288 | void __init perf_event_init(void) |
0793a61d | 9289 | { |
3c502e7a JW |
9290 | int ret; |
9291 | ||
2e80a82a PZ |
9292 | idr_init(&pmu_idr); |
9293 | ||
220b140b | 9294 | perf_event_init_all_cpus(); |
b0a873eb | 9295 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9296 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9297 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9298 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9299 | perf_tp_register(); |
9300 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9301 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9302 | |
9303 | ret = init_hw_breakpoint(); | |
9304 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9305 | |
9306 | /* do not patch jump label more than once per second */ | |
9307 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9308 | |
9309 | /* | |
9310 | * Build time assertion that we keep the data_head at the intended | |
9311 | * location. IOW, validation we got the __reserved[] size right. | |
9312 | */ | |
9313 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9314 | != 1024); | |
0793a61d | 9315 | } |
abe43400 | 9316 | |
fd979c01 CS |
9317 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9318 | char *page) | |
9319 | { | |
9320 | struct perf_pmu_events_attr *pmu_attr = | |
9321 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9322 | ||
9323 | if (pmu_attr->event_str) | |
9324 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9325 | ||
9326 | return 0; | |
9327 | } | |
9328 | ||
abe43400 PZ |
9329 | static int __init perf_event_sysfs_init(void) |
9330 | { | |
9331 | struct pmu *pmu; | |
9332 | int ret; | |
9333 | ||
9334 | mutex_lock(&pmus_lock); | |
9335 | ||
9336 | ret = bus_register(&pmu_bus); | |
9337 | if (ret) | |
9338 | goto unlock; | |
9339 | ||
9340 | list_for_each_entry(pmu, &pmus, entry) { | |
9341 | if (!pmu->name || pmu->type < 0) | |
9342 | continue; | |
9343 | ||
9344 | ret = pmu_dev_alloc(pmu); | |
9345 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9346 | } | |
9347 | pmu_bus_running = 1; | |
9348 | ret = 0; | |
9349 | ||
9350 | unlock: | |
9351 | mutex_unlock(&pmus_lock); | |
9352 | ||
9353 | return ret; | |
9354 | } | |
9355 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9356 | |
9357 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9358 | static struct cgroup_subsys_state * |
9359 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9360 | { |
9361 | struct perf_cgroup *jc; | |
e5d1367f | 9362 | |
1b15d055 | 9363 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9364 | if (!jc) |
9365 | return ERR_PTR(-ENOMEM); | |
9366 | ||
e5d1367f SE |
9367 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9368 | if (!jc->info) { | |
9369 | kfree(jc); | |
9370 | return ERR_PTR(-ENOMEM); | |
9371 | } | |
9372 | ||
e5d1367f SE |
9373 | return &jc->css; |
9374 | } | |
9375 | ||
eb95419b | 9376 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9377 | { |
eb95419b TH |
9378 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9379 | ||
e5d1367f SE |
9380 | free_percpu(jc->info); |
9381 | kfree(jc); | |
9382 | } | |
9383 | ||
9384 | static int __perf_cgroup_move(void *info) | |
9385 | { | |
9386 | struct task_struct *task = info; | |
ddaaf4e2 | 9387 | rcu_read_lock(); |
e5d1367f | 9388 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9389 | rcu_read_unlock(); |
e5d1367f SE |
9390 | return 0; |
9391 | } | |
9392 | ||
1f7dd3e5 | 9393 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9394 | { |
bb9d97b6 | 9395 | struct task_struct *task; |
1f7dd3e5 | 9396 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9397 | |
1f7dd3e5 | 9398 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9399 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9400 | } |
9401 | ||
073219e9 | 9402 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9403 | .css_alloc = perf_cgroup_css_alloc, |
9404 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9405 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9406 | }; |
9407 | #endif /* CONFIG_CGROUP_PERF */ |