Commit | Line | Data |
---|---|---|
0793a61d | 1 | /* |
57c0c15b | 2 | * Performance events core code: |
0793a61d | 3 | * |
98144511 | 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
e7e7ee2e | 5 | * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar |
90eec103 | 6 | * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra |
d36b6910 | 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
7b732a75 | 8 | * |
57c0c15b | 9 | * For licensing details see kernel-base/COPYING |
0793a61d TG |
10 | */ |
11 | ||
12 | #include <linux/fs.h> | |
b9cacc7b | 13 | #include <linux/mm.h> |
0793a61d TG |
14 | #include <linux/cpu.h> |
15 | #include <linux/smp.h> | |
2e80a82a | 16 | #include <linux/idr.h> |
04289bb9 | 17 | #include <linux/file.h> |
0793a61d | 18 | #include <linux/poll.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
76e1d904 | 20 | #include <linux/hash.h> |
12351ef8 | 21 | #include <linux/tick.h> |
0793a61d | 22 | #include <linux/sysfs.h> |
22a4f650 | 23 | #include <linux/dcache.h> |
0793a61d | 24 | #include <linux/percpu.h> |
22a4f650 | 25 | #include <linux/ptrace.h> |
c277443c | 26 | #include <linux/reboot.h> |
b9cacc7b | 27 | #include <linux/vmstat.h> |
abe43400 | 28 | #include <linux/device.h> |
6e5fdeed | 29 | #include <linux/export.h> |
906010b2 | 30 | #include <linux/vmalloc.h> |
b9cacc7b PZ |
31 | #include <linux/hardirq.h> |
32 | #include <linux/rculist.h> | |
0793a61d TG |
33 | #include <linux/uaccess.h> |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 36 | #include <linux/kernel_stat.h> |
39bed6cb | 37 | #include <linux/cgroup.h> |
cdd6c482 | 38 | #include <linux/perf_event.h> |
af658dca | 39 | #include <linux/trace_events.h> |
3c502e7a | 40 | #include <linux/hw_breakpoint.h> |
c5ebcedb | 41 | #include <linux/mm_types.h> |
c464c76e | 42 | #include <linux/module.h> |
f972eb63 | 43 | #include <linux/mman.h> |
b3f20785 | 44 | #include <linux/compat.h> |
2541517c AS |
45 | #include <linux/bpf.h> |
46 | #include <linux/filter.h> | |
0793a61d | 47 | |
76369139 FW |
48 | #include "internal.h" |
49 | ||
4e193bd4 TB |
50 | #include <asm/irq_regs.h> |
51 | ||
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); |
a8d757ef SE |
582 | |
583 | /* | |
584 | * next is NULL when called from perf_event_enable_on_exec() | |
585 | * that will systematically cause a cgroup_switch() | |
586 | */ | |
587 | if (next) | |
614e4c4e | 588 | cgrp2 = perf_cgroup_from_task(next, NULL); |
a8d757ef SE |
589 | |
590 | /* | |
591 | * only schedule out current cgroup events if we know | |
592 | * that we are switching to a different cgroup. Otherwise, | |
593 | * do no touch the cgroup events. | |
594 | */ | |
595 | if (cgrp1 != cgrp2) | |
596 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT); | |
ddaaf4e2 SE |
597 | |
598 | rcu_read_unlock(); | |
e5d1367f SE |
599 | } |
600 | ||
a8d757ef SE |
601 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
602 | struct task_struct *task) | |
e5d1367f | 603 | { |
a8d757ef SE |
604 | struct perf_cgroup *cgrp1; |
605 | struct perf_cgroup *cgrp2 = NULL; | |
606 | ||
ddaaf4e2 | 607 | rcu_read_lock(); |
a8d757ef SE |
608 | /* |
609 | * we come here when we know perf_cgroup_events > 0 | |
614e4c4e SE |
610 | * we do not need to pass the ctx here because we know |
611 | * we are holding the rcu lock | |
a8d757ef | 612 | */ |
614e4c4e | 613 | cgrp1 = perf_cgroup_from_task(task, NULL); |
a8d757ef SE |
614 | |
615 | /* prev can never be NULL */ | |
614e4c4e | 616 | cgrp2 = perf_cgroup_from_task(prev, NULL); |
a8d757ef SE |
617 | |
618 | /* | |
619 | * only need to schedule in cgroup events if we are changing | |
620 | * cgroup during ctxsw. Cgroup events were not scheduled | |
621 | * out of ctxsw out if that was not the case. | |
622 | */ | |
623 | if (cgrp1 != cgrp2) | |
624 | perf_cgroup_switch(task, PERF_CGROUP_SWIN); | |
ddaaf4e2 SE |
625 | |
626 | rcu_read_unlock(); | |
e5d1367f SE |
627 | } |
628 | ||
629 | static inline int perf_cgroup_connect(int fd, struct perf_event *event, | |
630 | struct perf_event_attr *attr, | |
631 | struct perf_event *group_leader) | |
632 | { | |
633 | struct perf_cgroup *cgrp; | |
634 | struct cgroup_subsys_state *css; | |
2903ff01 AV |
635 | struct fd f = fdget(fd); |
636 | int ret = 0; | |
e5d1367f | 637 | |
2903ff01 | 638 | if (!f.file) |
e5d1367f SE |
639 | return -EBADF; |
640 | ||
b583043e | 641 | css = css_tryget_online_from_dir(f.file->f_path.dentry, |
ec903c0c | 642 | &perf_event_cgrp_subsys); |
3db272c0 LZ |
643 | if (IS_ERR(css)) { |
644 | ret = PTR_ERR(css); | |
645 | goto out; | |
646 | } | |
e5d1367f SE |
647 | |
648 | cgrp = container_of(css, struct perf_cgroup, css); | |
649 | event->cgrp = cgrp; | |
650 | ||
651 | /* | |
652 | * all events in a group must monitor | |
653 | * the same cgroup because a task belongs | |
654 | * to only one perf cgroup at a time | |
655 | */ | |
656 | if (group_leader && group_leader->cgrp != cgrp) { | |
657 | perf_detach_cgroup(event); | |
658 | ret = -EINVAL; | |
e5d1367f | 659 | } |
3db272c0 | 660 | out: |
2903ff01 | 661 | fdput(f); |
e5d1367f SE |
662 | return ret; |
663 | } | |
664 | ||
665 | static inline void | |
666 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
667 | { | |
668 | struct perf_cgroup_info *t; | |
669 | t = per_cpu_ptr(event->cgrp->info, event->cpu); | |
670 | event->shadow_ctx_time = now - t->timestamp; | |
671 | } | |
672 | ||
673 | static inline void | |
674 | perf_cgroup_defer_enabled(struct perf_event *event) | |
675 | { | |
676 | /* | |
677 | * when the current task's perf cgroup does not match | |
678 | * the event's, we need to remember to call the | |
679 | * perf_mark_enable() function the first time a task with | |
680 | * a matching perf cgroup is scheduled in. | |
681 | */ | |
682 | if (is_cgroup_event(event) && !perf_cgroup_match(event)) | |
683 | event->cgrp_defer_enabled = 1; | |
684 | } | |
685 | ||
686 | static inline void | |
687 | perf_cgroup_mark_enabled(struct perf_event *event, | |
688 | struct perf_event_context *ctx) | |
689 | { | |
690 | struct perf_event *sub; | |
691 | u64 tstamp = perf_event_time(event); | |
692 | ||
693 | if (!event->cgrp_defer_enabled) | |
694 | return; | |
695 | ||
696 | event->cgrp_defer_enabled = 0; | |
697 | ||
698 | event->tstamp_enabled = tstamp - event->total_time_enabled; | |
699 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
700 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) { | |
701 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
702 | sub->cgrp_defer_enabled = 0; | |
703 | } | |
704 | } | |
705 | } | |
706 | #else /* !CONFIG_CGROUP_PERF */ | |
707 | ||
708 | static inline bool | |
709 | perf_cgroup_match(struct perf_event *event) | |
710 | { | |
711 | return true; | |
712 | } | |
713 | ||
714 | static inline void perf_detach_cgroup(struct perf_event *event) | |
715 | {} | |
716 | ||
717 | static inline int is_cgroup_event(struct perf_event *event) | |
718 | { | |
719 | return 0; | |
720 | } | |
721 | ||
722 | static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event) | |
723 | { | |
724 | return 0; | |
725 | } | |
726 | ||
727 | static inline void update_cgrp_time_from_event(struct perf_event *event) | |
728 | { | |
729 | } | |
730 | ||
731 | static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) | |
732 | { | |
733 | } | |
734 | ||
a8d757ef SE |
735 | static inline void perf_cgroup_sched_out(struct task_struct *task, |
736 | struct task_struct *next) | |
e5d1367f SE |
737 | { |
738 | } | |
739 | ||
a8d757ef SE |
740 | static inline void perf_cgroup_sched_in(struct task_struct *prev, |
741 | struct task_struct *task) | |
e5d1367f SE |
742 | { |
743 | } | |
744 | ||
745 | static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, | |
746 | struct perf_event_attr *attr, | |
747 | struct perf_event *group_leader) | |
748 | { | |
749 | return -EINVAL; | |
750 | } | |
751 | ||
752 | static inline void | |
3f7cce3c SE |
753 | perf_cgroup_set_timestamp(struct task_struct *task, |
754 | struct perf_event_context *ctx) | |
e5d1367f SE |
755 | { |
756 | } | |
757 | ||
758 | void | |
759 | perf_cgroup_switch(struct task_struct *task, struct task_struct *next) | |
760 | { | |
761 | } | |
762 | ||
763 | static inline void | |
764 | perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) | |
765 | { | |
766 | } | |
767 | ||
768 | static inline u64 perf_cgroup_event_time(struct perf_event *event) | |
769 | { | |
770 | return 0; | |
771 | } | |
772 | ||
773 | static inline void | |
774 | perf_cgroup_defer_enabled(struct perf_event *event) | |
775 | { | |
776 | } | |
777 | ||
778 | static inline void | |
779 | perf_cgroup_mark_enabled(struct perf_event *event, | |
780 | struct perf_event_context *ctx) | |
781 | { | |
782 | } | |
783 | #endif | |
784 | ||
9e630205 SE |
785 | /* |
786 | * set default to be dependent on timer tick just | |
787 | * like original code | |
788 | */ | |
789 | #define PERF_CPU_HRTIMER (1000 / HZ) | |
790 | /* | |
791 | * function must be called with interrupts disbled | |
792 | */ | |
272325c4 | 793 | static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) |
9e630205 SE |
794 | { |
795 | struct perf_cpu_context *cpuctx; | |
9e630205 SE |
796 | int rotations = 0; |
797 | ||
798 | WARN_ON(!irqs_disabled()); | |
799 | ||
800 | cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); | |
9e630205 SE |
801 | rotations = perf_rotate_context(cpuctx); |
802 | ||
4cfafd30 PZ |
803 | raw_spin_lock(&cpuctx->hrtimer_lock); |
804 | if (rotations) | |
9e630205 | 805 | hrtimer_forward_now(hr, cpuctx->hrtimer_interval); |
4cfafd30 PZ |
806 | else |
807 | cpuctx->hrtimer_active = 0; | |
808 | raw_spin_unlock(&cpuctx->hrtimer_lock); | |
9e630205 | 809 | |
4cfafd30 | 810 | return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; |
9e630205 SE |
811 | } |
812 | ||
272325c4 | 813 | static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) |
9e630205 | 814 | { |
272325c4 | 815 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 816 | struct pmu *pmu = cpuctx->ctx.pmu; |
272325c4 | 817 | u64 interval; |
9e630205 SE |
818 | |
819 | /* no multiplexing needed for SW PMU */ | |
820 | if (pmu->task_ctx_nr == perf_sw_context) | |
821 | return; | |
822 | ||
62b85639 SE |
823 | /* |
824 | * check default is sane, if not set then force to | |
825 | * default interval (1/tick) | |
826 | */ | |
272325c4 PZ |
827 | interval = pmu->hrtimer_interval_ms; |
828 | if (interval < 1) | |
829 | interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; | |
62b85639 | 830 | |
272325c4 | 831 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); |
9e630205 | 832 | |
4cfafd30 PZ |
833 | raw_spin_lock_init(&cpuctx->hrtimer_lock); |
834 | hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); | |
272325c4 | 835 | timer->function = perf_mux_hrtimer_handler; |
9e630205 SE |
836 | } |
837 | ||
272325c4 | 838 | static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) |
9e630205 | 839 | { |
272325c4 | 840 | struct hrtimer *timer = &cpuctx->hrtimer; |
9e630205 | 841 | struct pmu *pmu = cpuctx->ctx.pmu; |
4cfafd30 | 842 | unsigned long flags; |
9e630205 SE |
843 | |
844 | /* not for SW PMU */ | |
845 | if (pmu->task_ctx_nr == perf_sw_context) | |
272325c4 | 846 | return 0; |
9e630205 | 847 | |
4cfafd30 PZ |
848 | raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); |
849 | if (!cpuctx->hrtimer_active) { | |
850 | cpuctx->hrtimer_active = 1; | |
851 | hrtimer_forward_now(timer, cpuctx->hrtimer_interval); | |
852 | hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); | |
853 | } | |
854 | raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); | |
9e630205 | 855 | |
272325c4 | 856 | return 0; |
9e630205 SE |
857 | } |
858 | ||
33696fc0 | 859 | void perf_pmu_disable(struct pmu *pmu) |
9e35ad38 | 860 | { |
33696fc0 PZ |
861 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
862 | if (!(*count)++) | |
863 | pmu->pmu_disable(pmu); | |
9e35ad38 | 864 | } |
9e35ad38 | 865 | |
33696fc0 | 866 | void perf_pmu_enable(struct pmu *pmu) |
9e35ad38 | 867 | { |
33696fc0 PZ |
868 | int *count = this_cpu_ptr(pmu->pmu_disable_count); |
869 | if (!--(*count)) | |
870 | pmu->pmu_enable(pmu); | |
9e35ad38 | 871 | } |
9e35ad38 | 872 | |
2fde4f94 | 873 | static DEFINE_PER_CPU(struct list_head, active_ctx_list); |
e9d2b064 PZ |
874 | |
875 | /* | |
2fde4f94 MR |
876 | * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and |
877 | * perf_event_task_tick() are fully serialized because they're strictly cpu | |
878 | * affine and perf_event_ctx{activate,deactivate} are called with IRQs | |
879 | * disabled, while perf_event_task_tick is called from IRQ context. | |
e9d2b064 | 880 | */ |
2fde4f94 | 881 | static void perf_event_ctx_activate(struct perf_event_context *ctx) |
9e35ad38 | 882 | { |
2fde4f94 | 883 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
b5ab4cd5 | 884 | |
e9d2b064 | 885 | WARN_ON(!irqs_disabled()); |
b5ab4cd5 | 886 | |
2fde4f94 MR |
887 | WARN_ON(!list_empty(&ctx->active_ctx_list)); |
888 | ||
889 | list_add(&ctx->active_ctx_list, head); | |
890 | } | |
891 | ||
892 | static void perf_event_ctx_deactivate(struct perf_event_context *ctx) | |
893 | { | |
894 | WARN_ON(!irqs_disabled()); | |
895 | ||
896 | WARN_ON(list_empty(&ctx->active_ctx_list)); | |
897 | ||
898 | list_del_init(&ctx->active_ctx_list); | |
9e35ad38 | 899 | } |
9e35ad38 | 900 | |
cdd6c482 | 901 | static void get_ctx(struct perf_event_context *ctx) |
a63eaf34 | 902 | { |
e5289d4a | 903 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
a63eaf34 PM |
904 | } |
905 | ||
4af57ef2 YZ |
906 | static void free_ctx(struct rcu_head *head) |
907 | { | |
908 | struct perf_event_context *ctx; | |
909 | ||
910 | ctx = container_of(head, struct perf_event_context, rcu_head); | |
911 | kfree(ctx->task_ctx_data); | |
912 | kfree(ctx); | |
913 | } | |
914 | ||
cdd6c482 | 915 | static void put_ctx(struct perf_event_context *ctx) |
a63eaf34 | 916 | { |
564c2b21 PM |
917 | if (atomic_dec_and_test(&ctx->refcount)) { |
918 | if (ctx->parent_ctx) | |
919 | put_ctx(ctx->parent_ctx); | |
c93f7669 PM |
920 | if (ctx->task) |
921 | put_task_struct(ctx->task); | |
4af57ef2 | 922 | call_rcu(&ctx->rcu_head, free_ctx); |
564c2b21 | 923 | } |
a63eaf34 PM |
924 | } |
925 | ||
f63a8daa PZ |
926 | /* |
927 | * Because of perf_event::ctx migration in sys_perf_event_open::move_group and | |
928 | * perf_pmu_migrate_context() we need some magic. | |
929 | * | |
930 | * Those places that change perf_event::ctx will hold both | |
931 | * perf_event_ctx::mutex of the 'old' and 'new' ctx value. | |
932 | * | |
8b10c5e2 PZ |
933 | * Lock ordering is by mutex address. There are two other sites where |
934 | * perf_event_context::mutex nests and those are: | |
935 | * | |
936 | * - perf_event_exit_task_context() [ child , 0 ] | |
937 | * __perf_event_exit_task() | |
938 | * sync_child_event() | |
939 | * put_event() [ parent, 1 ] | |
940 | * | |
941 | * - perf_event_init_context() [ parent, 0 ] | |
942 | * inherit_task_group() | |
943 | * inherit_group() | |
944 | * inherit_event() | |
945 | * perf_event_alloc() | |
946 | * perf_init_event() | |
947 | * perf_try_init_event() [ child , 1 ] | |
948 | * | |
949 | * While it appears there is an obvious deadlock here -- the parent and child | |
950 | * nesting levels are inverted between the two. This is in fact safe because | |
951 | * life-time rules separate them. That is an exiting task cannot fork, and a | |
952 | * spawning task cannot (yet) exit. | |
953 | * | |
954 | * But remember that that these are parent<->child context relations, and | |
955 | * migration does not affect children, therefore these two orderings should not | |
956 | * interact. | |
f63a8daa PZ |
957 | * |
958 | * The change in perf_event::ctx does not affect children (as claimed above) | |
959 | * because the sys_perf_event_open() case will install a new event and break | |
960 | * the ctx parent<->child relation, and perf_pmu_migrate_context() is only | |
961 | * concerned with cpuctx and that doesn't have children. | |
962 | * | |
963 | * The places that change perf_event::ctx will issue: | |
964 | * | |
965 | * perf_remove_from_context(); | |
966 | * synchronize_rcu(); | |
967 | * perf_install_in_context(); | |
968 | * | |
969 | * to affect the change. The remove_from_context() + synchronize_rcu() should | |
970 | * quiesce the event, after which we can install it in the new location. This | |
971 | * means that only external vectors (perf_fops, prctl) can perturb the event | |
972 | * while in transit. Therefore all such accessors should also acquire | |
973 | * perf_event_context::mutex to serialize against this. | |
974 | * | |
975 | * However; because event->ctx can change while we're waiting to acquire | |
976 | * ctx->mutex we must be careful and use the below perf_event_ctx_lock() | |
977 | * function. | |
978 | * | |
979 | * Lock order: | |
980 | * task_struct::perf_event_mutex | |
981 | * perf_event_context::mutex | |
982 | * perf_event_context::lock | |
983 | * perf_event::child_mutex; | |
984 | * perf_event::mmap_mutex | |
985 | * mmap_sem | |
986 | */ | |
a83fe28e PZ |
987 | static struct perf_event_context * |
988 | perf_event_ctx_lock_nested(struct perf_event *event, int nesting) | |
f63a8daa PZ |
989 | { |
990 | struct perf_event_context *ctx; | |
991 | ||
992 | again: | |
993 | rcu_read_lock(); | |
994 | ctx = ACCESS_ONCE(event->ctx); | |
995 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
996 | rcu_read_unlock(); | |
997 | goto again; | |
998 | } | |
999 | rcu_read_unlock(); | |
1000 | ||
a83fe28e | 1001 | mutex_lock_nested(&ctx->mutex, nesting); |
f63a8daa PZ |
1002 | if (event->ctx != ctx) { |
1003 | mutex_unlock(&ctx->mutex); | |
1004 | put_ctx(ctx); | |
1005 | goto again; | |
1006 | } | |
1007 | ||
1008 | return ctx; | |
1009 | } | |
1010 | ||
a83fe28e PZ |
1011 | static inline struct perf_event_context * |
1012 | perf_event_ctx_lock(struct perf_event *event) | |
1013 | { | |
1014 | return perf_event_ctx_lock_nested(event, 0); | |
1015 | } | |
1016 | ||
f63a8daa PZ |
1017 | static void perf_event_ctx_unlock(struct perf_event *event, |
1018 | struct perf_event_context *ctx) | |
1019 | { | |
1020 | mutex_unlock(&ctx->mutex); | |
1021 | put_ctx(ctx); | |
1022 | } | |
1023 | ||
211de6eb PZ |
1024 | /* |
1025 | * This must be done under the ctx->lock, such as to serialize against | |
1026 | * context_equiv(), therefore we cannot call put_ctx() since that might end up | |
1027 | * calling scheduler related locks and ctx->lock nests inside those. | |
1028 | */ | |
1029 | static __must_check struct perf_event_context * | |
1030 | unclone_ctx(struct perf_event_context *ctx) | |
71a851b4 | 1031 | { |
211de6eb PZ |
1032 | struct perf_event_context *parent_ctx = ctx->parent_ctx; |
1033 | ||
1034 | lockdep_assert_held(&ctx->lock); | |
1035 | ||
1036 | if (parent_ctx) | |
71a851b4 | 1037 | ctx->parent_ctx = NULL; |
5a3126d4 | 1038 | ctx->generation++; |
211de6eb PZ |
1039 | |
1040 | return parent_ctx; | |
71a851b4 PZ |
1041 | } |
1042 | ||
6844c09d ACM |
1043 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
1044 | { | |
1045 | /* | |
1046 | * only top level events have the pid namespace they were created in | |
1047 | */ | |
1048 | if (event->parent) | |
1049 | event = event->parent; | |
1050 | ||
1051 | return task_tgid_nr_ns(p, event->ns); | |
1052 | } | |
1053 | ||
1054 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) | |
1055 | { | |
1056 | /* | |
1057 | * only top level events have the pid namespace they were created in | |
1058 | */ | |
1059 | if (event->parent) | |
1060 | event = event->parent; | |
1061 | ||
1062 | return task_pid_nr_ns(p, event->ns); | |
1063 | } | |
1064 | ||
7f453c24 | 1065 | /* |
cdd6c482 | 1066 | * If we inherit events we want to return the parent event id |
7f453c24 PZ |
1067 | * to userspace. |
1068 | */ | |
cdd6c482 | 1069 | static u64 primary_event_id(struct perf_event *event) |
7f453c24 | 1070 | { |
cdd6c482 | 1071 | u64 id = event->id; |
7f453c24 | 1072 | |
cdd6c482 IM |
1073 | if (event->parent) |
1074 | id = event->parent->id; | |
7f453c24 PZ |
1075 | |
1076 | return id; | |
1077 | } | |
1078 | ||
25346b93 | 1079 | /* |
cdd6c482 | 1080 | * Get the perf_event_context for a task and lock it. |
25346b93 PM |
1081 | * This has to cope with with the fact that until it is locked, |
1082 | * the context could get moved to another task. | |
1083 | */ | |
cdd6c482 | 1084 | static struct perf_event_context * |
8dc85d54 | 1085 | perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags) |
25346b93 | 1086 | { |
cdd6c482 | 1087 | struct perf_event_context *ctx; |
25346b93 | 1088 | |
9ed6060d | 1089 | retry: |
058ebd0e PZ |
1090 | /* |
1091 | * One of the few rules of preemptible RCU is that one cannot do | |
1092 | * rcu_read_unlock() while holding a scheduler (or nested) lock when | |
2fd59077 | 1093 | * part of the read side critical section was irqs-enabled -- see |
058ebd0e PZ |
1094 | * rcu_read_unlock_special(). |
1095 | * | |
1096 | * Since ctx->lock nests under rq->lock we must ensure the entire read | |
2fd59077 | 1097 | * side critical section has interrupts disabled. |
058ebd0e | 1098 | */ |
2fd59077 | 1099 | local_irq_save(*flags); |
058ebd0e | 1100 | rcu_read_lock(); |
8dc85d54 | 1101 | ctx = rcu_dereference(task->perf_event_ctxp[ctxn]); |
25346b93 PM |
1102 | if (ctx) { |
1103 | /* | |
1104 | * If this context is a clone of another, it might | |
1105 | * get swapped for another underneath us by | |
cdd6c482 | 1106 | * perf_event_task_sched_out, though the |
25346b93 PM |
1107 | * rcu_read_lock() protects us from any context |
1108 | * getting freed. Lock the context and check if it | |
1109 | * got swapped before we could get the lock, and retry | |
1110 | * if so. If we locked the right context, then it | |
1111 | * can't get swapped on us any more. | |
1112 | */ | |
2fd59077 | 1113 | raw_spin_lock(&ctx->lock); |
8dc85d54 | 1114 | if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) { |
2fd59077 | 1115 | raw_spin_unlock(&ctx->lock); |
058ebd0e | 1116 | rcu_read_unlock(); |
2fd59077 | 1117 | local_irq_restore(*flags); |
25346b93 PM |
1118 | goto retry; |
1119 | } | |
b49a9e7e PZ |
1120 | |
1121 | if (!atomic_inc_not_zero(&ctx->refcount)) { | |
2fd59077 | 1122 | raw_spin_unlock(&ctx->lock); |
b49a9e7e PZ |
1123 | ctx = NULL; |
1124 | } | |
25346b93 PM |
1125 | } |
1126 | rcu_read_unlock(); | |
2fd59077 PM |
1127 | if (!ctx) |
1128 | local_irq_restore(*flags); | |
25346b93 PM |
1129 | return ctx; |
1130 | } | |
1131 | ||
1132 | /* | |
1133 | * Get the context for a task and increment its pin_count so it | |
1134 | * can't get swapped to another task. This also increments its | |
1135 | * reference count so that the context can't get freed. | |
1136 | */ | |
8dc85d54 PZ |
1137 | static struct perf_event_context * |
1138 | perf_pin_task_context(struct task_struct *task, int ctxn) | |
25346b93 | 1139 | { |
cdd6c482 | 1140 | struct perf_event_context *ctx; |
25346b93 PM |
1141 | unsigned long flags; |
1142 | ||
8dc85d54 | 1143 | ctx = perf_lock_task_context(task, ctxn, &flags); |
25346b93 PM |
1144 | if (ctx) { |
1145 | ++ctx->pin_count; | |
e625cce1 | 1146 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1147 | } |
1148 | return ctx; | |
1149 | } | |
1150 | ||
cdd6c482 | 1151 | static void perf_unpin_context(struct perf_event_context *ctx) |
25346b93 PM |
1152 | { |
1153 | unsigned long flags; | |
1154 | ||
e625cce1 | 1155 | raw_spin_lock_irqsave(&ctx->lock, flags); |
25346b93 | 1156 | --ctx->pin_count; |
e625cce1 | 1157 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
25346b93 PM |
1158 | } |
1159 | ||
f67218c3 PZ |
1160 | /* |
1161 | * Update the record of the current time in a context. | |
1162 | */ | |
1163 | static void update_context_time(struct perf_event_context *ctx) | |
1164 | { | |
1165 | u64 now = perf_clock(); | |
1166 | ||
1167 | ctx->time += now - ctx->timestamp; | |
1168 | ctx->timestamp = now; | |
1169 | } | |
1170 | ||
4158755d SE |
1171 | static u64 perf_event_time(struct perf_event *event) |
1172 | { | |
1173 | struct perf_event_context *ctx = event->ctx; | |
e5d1367f SE |
1174 | |
1175 | if (is_cgroup_event(event)) | |
1176 | return perf_cgroup_event_time(event); | |
1177 | ||
4158755d SE |
1178 | return ctx ? ctx->time : 0; |
1179 | } | |
1180 | ||
f67218c3 PZ |
1181 | /* |
1182 | * Update the total_time_enabled and total_time_running fields for a event. | |
b7526f0c | 1183 | * The caller of this function needs to hold the ctx->lock. |
f67218c3 PZ |
1184 | */ |
1185 | static void update_event_times(struct perf_event *event) | |
1186 | { | |
1187 | struct perf_event_context *ctx = event->ctx; | |
1188 | u64 run_end; | |
1189 | ||
1190 | if (event->state < PERF_EVENT_STATE_INACTIVE || | |
1191 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) | |
1192 | return; | |
e5d1367f SE |
1193 | /* |
1194 | * in cgroup mode, time_enabled represents | |
1195 | * the time the event was enabled AND active | |
1196 | * tasks were in the monitored cgroup. This is | |
1197 | * independent of the activity of the context as | |
1198 | * there may be a mix of cgroup and non-cgroup events. | |
1199 | * | |
1200 | * That is why we treat cgroup events differently | |
1201 | * here. | |
1202 | */ | |
1203 | if (is_cgroup_event(event)) | |
46cd6a7f | 1204 | run_end = perf_cgroup_event_time(event); |
e5d1367f SE |
1205 | else if (ctx->is_active) |
1206 | run_end = ctx->time; | |
acd1d7c1 PZ |
1207 | else |
1208 | run_end = event->tstamp_stopped; | |
1209 | ||
1210 | event->total_time_enabled = run_end - event->tstamp_enabled; | |
f67218c3 PZ |
1211 | |
1212 | if (event->state == PERF_EVENT_STATE_INACTIVE) | |
1213 | run_end = event->tstamp_stopped; | |
1214 | else | |
4158755d | 1215 | run_end = perf_event_time(event); |
f67218c3 PZ |
1216 | |
1217 | event->total_time_running = run_end - event->tstamp_running; | |
e5d1367f | 1218 | |
f67218c3 PZ |
1219 | } |
1220 | ||
96c21a46 PZ |
1221 | /* |
1222 | * Update total_time_enabled and total_time_running for all events in a group. | |
1223 | */ | |
1224 | static void update_group_times(struct perf_event *leader) | |
1225 | { | |
1226 | struct perf_event *event; | |
1227 | ||
1228 | update_event_times(leader); | |
1229 | list_for_each_entry(event, &leader->sibling_list, group_entry) | |
1230 | update_event_times(event); | |
1231 | } | |
1232 | ||
889ff015 FW |
1233 | static struct list_head * |
1234 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) | |
1235 | { | |
1236 | if (event->attr.pinned) | |
1237 | return &ctx->pinned_groups; | |
1238 | else | |
1239 | return &ctx->flexible_groups; | |
1240 | } | |
1241 | ||
fccc714b | 1242 | /* |
cdd6c482 | 1243 | * Add a event from the lists for its context. |
fccc714b PZ |
1244 | * Must be called with ctx->mutex and ctx->lock held. |
1245 | */ | |
04289bb9 | 1246 | static void |
cdd6c482 | 1247 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1248 | { |
8a49542c PZ |
1249 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1250 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1251 | |
1252 | /* | |
8a49542c PZ |
1253 | * If we're a stand alone event or group leader, we go to the context |
1254 | * list, group events are kept attached to the group so that | |
1255 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1256 | */ |
8a49542c | 1257 | if (event->group_leader == event) { |
889ff015 FW |
1258 | struct list_head *list; |
1259 | ||
d6f962b5 FW |
1260 | if (is_software_event(event)) |
1261 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1262 | ||
889ff015 FW |
1263 | list = ctx_group_list(event, ctx); |
1264 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1265 | } |
592903cd | 1266 | |
08309379 | 1267 | if (is_cgroup_event(event)) |
e5d1367f | 1268 | ctx->nr_cgroups++; |
e5d1367f | 1269 | |
cdd6c482 IM |
1270 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1271 | ctx->nr_events++; | |
1272 | if (event->attr.inherit_stat) | |
bfbd3381 | 1273 | ctx->nr_stat++; |
5a3126d4 PZ |
1274 | |
1275 | ctx->generation++; | |
04289bb9 IM |
1276 | } |
1277 | ||
0231bb53 JO |
1278 | /* |
1279 | * Initialize event state based on the perf_event_attr::disabled. | |
1280 | */ | |
1281 | static inline void perf_event__state_init(struct perf_event *event) | |
1282 | { | |
1283 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1284 | PERF_EVENT_STATE_INACTIVE; | |
1285 | } | |
1286 | ||
a723968c | 1287 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1288 | { |
1289 | int entry = sizeof(u64); /* value */ | |
1290 | int size = 0; | |
1291 | int nr = 1; | |
1292 | ||
1293 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1294 | size += sizeof(u64); | |
1295 | ||
1296 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1297 | size += sizeof(u64); | |
1298 | ||
1299 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1300 | entry += sizeof(u64); | |
1301 | ||
1302 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1303 | nr += nr_siblings; |
c320c7b7 ACM |
1304 | size += sizeof(u64); |
1305 | } | |
1306 | ||
1307 | size += entry * nr; | |
1308 | event->read_size = size; | |
1309 | } | |
1310 | ||
a723968c | 1311 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1312 | { |
1313 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1314 | u16 size = 0; |
1315 | ||
c320c7b7 ACM |
1316 | if (sample_type & PERF_SAMPLE_IP) |
1317 | size += sizeof(data->ip); | |
1318 | ||
6844c09d ACM |
1319 | if (sample_type & PERF_SAMPLE_ADDR) |
1320 | size += sizeof(data->addr); | |
1321 | ||
1322 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1323 | size += sizeof(data->period); | |
1324 | ||
c3feedf2 AK |
1325 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1326 | size += sizeof(data->weight); | |
1327 | ||
6844c09d ACM |
1328 | if (sample_type & PERF_SAMPLE_READ) |
1329 | size += event->read_size; | |
1330 | ||
d6be9ad6 SE |
1331 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1332 | size += sizeof(data->data_src.val); | |
1333 | ||
fdfbbd07 AK |
1334 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1335 | size += sizeof(data->txn); | |
1336 | ||
6844c09d ACM |
1337 | event->header_size = size; |
1338 | } | |
1339 | ||
a723968c PZ |
1340 | /* |
1341 | * Called at perf_event creation and when events are attached/detached from a | |
1342 | * group. | |
1343 | */ | |
1344 | static void perf_event__header_size(struct perf_event *event) | |
1345 | { | |
1346 | __perf_event_read_size(event, | |
1347 | event->group_leader->nr_siblings); | |
1348 | __perf_event_header_size(event, event->attr.sample_type); | |
1349 | } | |
1350 | ||
6844c09d ACM |
1351 | static void perf_event__id_header_size(struct perf_event *event) |
1352 | { | |
1353 | struct perf_sample_data *data; | |
1354 | u64 sample_type = event->attr.sample_type; | |
1355 | u16 size = 0; | |
1356 | ||
c320c7b7 ACM |
1357 | if (sample_type & PERF_SAMPLE_TID) |
1358 | size += sizeof(data->tid_entry); | |
1359 | ||
1360 | if (sample_type & PERF_SAMPLE_TIME) | |
1361 | size += sizeof(data->time); | |
1362 | ||
ff3d527c AH |
1363 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1364 | size += sizeof(data->id); | |
1365 | ||
c320c7b7 ACM |
1366 | if (sample_type & PERF_SAMPLE_ID) |
1367 | size += sizeof(data->id); | |
1368 | ||
1369 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1370 | size += sizeof(data->stream_id); | |
1371 | ||
1372 | if (sample_type & PERF_SAMPLE_CPU) | |
1373 | size += sizeof(data->cpu_entry); | |
1374 | ||
6844c09d | 1375 | event->id_header_size = size; |
c320c7b7 ACM |
1376 | } |
1377 | ||
a723968c PZ |
1378 | static bool perf_event_validate_size(struct perf_event *event) |
1379 | { | |
1380 | /* | |
1381 | * The values computed here will be over-written when we actually | |
1382 | * attach the event. | |
1383 | */ | |
1384 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1385 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1386 | perf_event__id_header_size(event); | |
1387 | ||
1388 | /* | |
1389 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1390 | * Conservative limit to allow for callchains and other variable fields. | |
1391 | */ | |
1392 | if (event->read_size + event->header_size + | |
1393 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1394 | return false; | |
1395 | ||
1396 | return true; | |
1397 | } | |
1398 | ||
8a49542c PZ |
1399 | static void perf_group_attach(struct perf_event *event) |
1400 | { | |
c320c7b7 | 1401 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1402 | |
74c3337c PZ |
1403 | /* |
1404 | * We can have double attach due to group movement in perf_event_open. | |
1405 | */ | |
1406 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1407 | return; | |
1408 | ||
8a49542c PZ |
1409 | event->attach_state |= PERF_ATTACH_GROUP; |
1410 | ||
1411 | if (group_leader == event) | |
1412 | return; | |
1413 | ||
652884fe PZ |
1414 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1415 | ||
8a49542c PZ |
1416 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1417 | !is_software_event(event)) | |
1418 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1419 | ||
1420 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1421 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1422 | |
1423 | perf_event__header_size(group_leader); | |
1424 | ||
1425 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1426 | perf_event__header_size(pos); | |
8a49542c PZ |
1427 | } |
1428 | ||
a63eaf34 | 1429 | /* |
cdd6c482 | 1430 | * Remove a event from the lists for its context. |
fccc714b | 1431 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1432 | */ |
04289bb9 | 1433 | static void |
cdd6c482 | 1434 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1435 | { |
68cacd29 | 1436 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1437 | |
1438 | WARN_ON_ONCE(event->ctx != ctx); | |
1439 | lockdep_assert_held(&ctx->lock); | |
1440 | ||
8a49542c PZ |
1441 | /* |
1442 | * We can have double detach due to exit/hot-unplug + close. | |
1443 | */ | |
1444 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1445 | return; |
8a49542c PZ |
1446 | |
1447 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1448 | ||
68cacd29 | 1449 | if (is_cgroup_event(event)) { |
e5d1367f | 1450 | ctx->nr_cgroups--; |
68cacd29 SE |
1451 | cpuctx = __get_cpu_context(ctx); |
1452 | /* | |
1453 | * if there are no more cgroup events | |
1454 | * then cler cgrp to avoid stale pointer | |
1455 | * in update_cgrp_time_from_cpuctx() | |
1456 | */ | |
1457 | if (!ctx->nr_cgroups) | |
1458 | cpuctx->cgrp = NULL; | |
1459 | } | |
e5d1367f | 1460 | |
cdd6c482 IM |
1461 | ctx->nr_events--; |
1462 | if (event->attr.inherit_stat) | |
bfbd3381 | 1463 | ctx->nr_stat--; |
8bc20959 | 1464 | |
cdd6c482 | 1465 | list_del_rcu(&event->event_entry); |
04289bb9 | 1466 | |
8a49542c PZ |
1467 | if (event->group_leader == event) |
1468 | list_del_init(&event->group_entry); | |
5c148194 | 1469 | |
96c21a46 | 1470 | update_group_times(event); |
b2e74a26 SE |
1471 | |
1472 | /* | |
1473 | * If event was in error state, then keep it | |
1474 | * that way, otherwise bogus counts will be | |
1475 | * returned on read(). The only way to get out | |
1476 | * of error state is by explicit re-enabling | |
1477 | * of the event | |
1478 | */ | |
1479 | if (event->state > PERF_EVENT_STATE_OFF) | |
1480 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1481 | |
1482 | ctx->generation++; | |
050735b0 PZ |
1483 | } |
1484 | ||
8a49542c | 1485 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1486 | { |
1487 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1488 | struct list_head *list = NULL; |
1489 | ||
1490 | /* | |
1491 | * We can have double detach due to exit/hot-unplug + close. | |
1492 | */ | |
1493 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1494 | return; | |
1495 | ||
1496 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1497 | ||
1498 | /* | |
1499 | * If this is a sibling, remove it from its group. | |
1500 | */ | |
1501 | if (event->group_leader != event) { | |
1502 | list_del_init(&event->group_entry); | |
1503 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1504 | goto out; |
8a49542c PZ |
1505 | } |
1506 | ||
1507 | if (!list_empty(&event->group_entry)) | |
1508 | list = &event->group_entry; | |
2e2af50b | 1509 | |
04289bb9 | 1510 | /* |
cdd6c482 IM |
1511 | * If this was a group event with sibling events then |
1512 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1513 | * to whatever list we are on. |
04289bb9 | 1514 | */ |
cdd6c482 | 1515 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1516 | if (list) |
1517 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1518 | sibling->group_leader = sibling; |
d6f962b5 FW |
1519 | |
1520 | /* Inherit group flags from the previous leader */ | |
1521 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1522 | |
1523 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1524 | } |
c320c7b7 ACM |
1525 | |
1526 | out: | |
1527 | perf_event__header_size(event->group_leader); | |
1528 | ||
1529 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1530 | perf_event__header_size(tmp); | |
04289bb9 IM |
1531 | } |
1532 | ||
fadfe7be JO |
1533 | /* |
1534 | * User event without the task. | |
1535 | */ | |
1536 | static bool is_orphaned_event(struct perf_event *event) | |
1537 | { | |
1538 | return event && !is_kernel_event(event) && !event->owner; | |
1539 | } | |
1540 | ||
1541 | /* | |
1542 | * Event has a parent but parent's task finished and it's | |
1543 | * alive only because of children holding refference. | |
1544 | */ | |
1545 | static bool is_orphaned_child(struct perf_event *event) | |
1546 | { | |
1547 | return is_orphaned_event(event->parent); | |
1548 | } | |
1549 | ||
1550 | static void orphans_remove_work(struct work_struct *work); | |
1551 | ||
1552 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1553 | { | |
1554 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1555 | return; | |
1556 | ||
1557 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1558 | get_ctx(ctx); | |
1559 | ctx->orphans_remove_sched = true; | |
1560 | } | |
1561 | } | |
1562 | ||
1563 | static int __init perf_workqueue_init(void) | |
1564 | { | |
1565 | perf_wq = create_singlethread_workqueue("perf"); | |
1566 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1567 | return perf_wq ? 0 : -1; | |
1568 | } | |
1569 | ||
1570 | core_initcall(perf_workqueue_init); | |
1571 | ||
66eb579e MR |
1572 | static inline int pmu_filter_match(struct perf_event *event) |
1573 | { | |
1574 | struct pmu *pmu = event->pmu; | |
1575 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1576 | } | |
1577 | ||
fa66f07a SE |
1578 | static inline int |
1579 | event_filter_match(struct perf_event *event) | |
1580 | { | |
e5d1367f | 1581 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1582 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1583 | } |
1584 | ||
9ffcfa6f SE |
1585 | static void |
1586 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1587 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1588 | struct perf_event_context *ctx) |
3b6f9e5c | 1589 | { |
4158755d | 1590 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1591 | u64 delta; |
652884fe PZ |
1592 | |
1593 | WARN_ON_ONCE(event->ctx != ctx); | |
1594 | lockdep_assert_held(&ctx->lock); | |
1595 | ||
fa66f07a SE |
1596 | /* |
1597 | * An event which could not be activated because of | |
1598 | * filter mismatch still needs to have its timings | |
1599 | * maintained, otherwise bogus information is return | |
1600 | * via read() for time_enabled, time_running: | |
1601 | */ | |
1602 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1603 | && !event_filter_match(event)) { | |
e5d1367f | 1604 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1605 | event->tstamp_running += delta; |
4158755d | 1606 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1607 | } |
1608 | ||
cdd6c482 | 1609 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1610 | return; |
3b6f9e5c | 1611 | |
44377277 AS |
1612 | perf_pmu_disable(event->pmu); |
1613 | ||
cdd6c482 IM |
1614 | event->state = PERF_EVENT_STATE_INACTIVE; |
1615 | if (event->pending_disable) { | |
1616 | event->pending_disable = 0; | |
1617 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1618 | } |
4158755d | 1619 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1620 | event->pmu->del(event, 0); |
cdd6c482 | 1621 | event->oncpu = -1; |
3b6f9e5c | 1622 | |
cdd6c482 | 1623 | if (!is_software_event(event)) |
3b6f9e5c | 1624 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1625 | if (!--ctx->nr_active) |
1626 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1627 | if (event->attr.freq && event->attr.sample_freq) |
1628 | ctx->nr_freq--; | |
cdd6c482 | 1629 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1630 | cpuctx->exclusive = 0; |
44377277 | 1631 | |
fadfe7be JO |
1632 | if (is_orphaned_child(event)) |
1633 | schedule_orphans_remove(ctx); | |
1634 | ||
44377277 | 1635 | perf_pmu_enable(event->pmu); |
3b6f9e5c PM |
1636 | } |
1637 | ||
d859e29f | 1638 | static void |
cdd6c482 | 1639 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1640 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1641 | struct perf_event_context *ctx) |
d859e29f | 1642 | { |
cdd6c482 | 1643 | struct perf_event *event; |
fa66f07a | 1644 | int state = group_event->state; |
d859e29f | 1645 | |
cdd6c482 | 1646 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1647 | |
1648 | /* | |
1649 | * Schedule out siblings (if any): | |
1650 | */ | |
cdd6c482 IM |
1651 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1652 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1653 | |
fa66f07a | 1654 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1655 | cpuctx->exclusive = 0; |
1656 | } | |
1657 | ||
46ce0fe9 PZ |
1658 | struct remove_event { |
1659 | struct perf_event *event; | |
1660 | bool detach_group; | |
1661 | }; | |
1662 | ||
0017960f PZ |
1663 | static void ___perf_remove_from_context(void *info) |
1664 | { | |
1665 | struct remove_event *re = info; | |
1666 | struct perf_event *event = re->event; | |
1667 | struct perf_event_context *ctx = event->ctx; | |
1668 | ||
1669 | if (re->detach_group) | |
1670 | perf_group_detach(event); | |
1671 | list_del_event(event, ctx); | |
1672 | } | |
1673 | ||
0793a61d | 1674 | /* |
cdd6c482 | 1675 | * Cross CPU call to remove a performance event |
0793a61d | 1676 | * |
cdd6c482 | 1677 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1678 | * remove it from the context list. |
1679 | */ | |
fe4b04fa | 1680 | static int __perf_remove_from_context(void *info) |
0793a61d | 1681 | { |
46ce0fe9 PZ |
1682 | struct remove_event *re = info; |
1683 | struct perf_event *event = re->event; | |
cdd6c482 | 1684 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1685 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
0793a61d | 1686 | |
e625cce1 | 1687 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 1688 | event_sched_out(event, cpuctx, ctx); |
46ce0fe9 PZ |
1689 | if (re->detach_group) |
1690 | perf_group_detach(event); | |
cdd6c482 | 1691 | list_del_event(event, ctx); |
64ce3126 PZ |
1692 | if (!ctx->nr_events && cpuctx->task_ctx == ctx) { |
1693 | ctx->is_active = 0; | |
1694 | cpuctx->task_ctx = NULL; | |
1695 | } | |
e625cce1 | 1696 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1697 | |
1698 | return 0; | |
0793a61d TG |
1699 | } |
1700 | ||
0793a61d | 1701 | /* |
cdd6c482 | 1702 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1703 | * |
cdd6c482 | 1704 | * CPU events are removed with a smp call. For task events we only |
0793a61d | 1705 | * call when the task is on a CPU. |
c93f7669 | 1706 | * |
cdd6c482 IM |
1707 | * If event->ctx is a cloned context, callers must make sure that |
1708 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1709 | * remains valid. This is OK when called from perf_release since |
1710 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1711 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1712 | * context has been detached from its task. |
0793a61d | 1713 | */ |
46ce0fe9 | 1714 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1715 | { |
cdd6c482 | 1716 | struct perf_event_context *ctx = event->ctx; |
46ce0fe9 PZ |
1717 | struct remove_event re = { |
1718 | .event = event, | |
1719 | .detach_group = detach_group, | |
1720 | }; | |
0793a61d | 1721 | |
fe4b04fa PZ |
1722 | lockdep_assert_held(&ctx->mutex); |
1723 | ||
0017960f PZ |
1724 | event_function_call(event, __perf_remove_from_context, |
1725 | ___perf_remove_from_context, &re); | |
0793a61d TG |
1726 | } |
1727 | ||
d859e29f | 1728 | /* |
cdd6c482 | 1729 | * Cross CPU call to disable a performance event |
d859e29f | 1730 | */ |
500ad2d8 | 1731 | int __perf_event_disable(void *info) |
d859e29f | 1732 | { |
cdd6c482 | 1733 | struct perf_event *event = info; |
cdd6c482 | 1734 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1735 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f PM |
1736 | |
1737 | /* | |
cdd6c482 IM |
1738 | * If this is a per-task event, need to check whether this |
1739 | * event's task is the current task on this cpu. | |
fe4b04fa PZ |
1740 | * |
1741 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1742 | * flipping contexts around. | |
d859e29f | 1743 | */ |
665c2142 | 1744 | if (ctx->task && cpuctx->task_ctx != ctx) |
fe4b04fa | 1745 | return -EINVAL; |
d859e29f | 1746 | |
e625cce1 | 1747 | raw_spin_lock(&ctx->lock); |
d859e29f PM |
1748 | |
1749 | /* | |
cdd6c482 | 1750 | * If the event is on, turn it off. |
d859e29f PM |
1751 | * If it is in error state, leave it in error state. |
1752 | */ | |
cdd6c482 | 1753 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
4af4998b | 1754 | update_context_time(ctx); |
e5d1367f | 1755 | update_cgrp_time_from_event(event); |
cdd6c482 IM |
1756 | update_group_times(event); |
1757 | if (event == event->group_leader) | |
1758 | group_sched_out(event, cpuctx, ctx); | |
d859e29f | 1759 | else |
cdd6c482 IM |
1760 | event_sched_out(event, cpuctx, ctx); |
1761 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f PM |
1762 | } |
1763 | ||
e625cce1 | 1764 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1765 | |
1766 | return 0; | |
d859e29f PM |
1767 | } |
1768 | ||
7b648018 PZ |
1769 | void ___perf_event_disable(void *info) |
1770 | { | |
1771 | struct perf_event *event = info; | |
1772 | ||
1773 | /* | |
1774 | * Since we have the lock this context can't be scheduled | |
1775 | * in, so we can change the state safely. | |
1776 | */ | |
1777 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
1778 | update_group_times(event); | |
1779 | event->state = PERF_EVENT_STATE_OFF; | |
1780 | } | |
1781 | } | |
1782 | ||
d859e29f | 1783 | /* |
cdd6c482 | 1784 | * Disable a event. |
c93f7669 | 1785 | * |
cdd6c482 IM |
1786 | * If event->ctx is a cloned context, callers must make sure that |
1787 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1788 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1789 | * perf_event_for_each_child or perf_event_for_each because they |
1790 | * hold the top-level event's child_mutex, so any descendant that | |
1791 | * goes to exit will block in sync_child_event. | |
1792 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1793 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1794 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1795 | */ |
f63a8daa | 1796 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1797 | { |
cdd6c482 | 1798 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1799 | |
e625cce1 | 1800 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1801 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1802 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1803 | return; |
53cfbf59 | 1804 | } |
e625cce1 | 1805 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 PZ |
1806 | |
1807 | event_function_call(event, __perf_event_disable, | |
1808 | ___perf_event_disable, event); | |
d859e29f | 1809 | } |
f63a8daa PZ |
1810 | |
1811 | /* | |
1812 | * Strictly speaking kernel users cannot create groups and therefore this | |
1813 | * interface does not need the perf_event_ctx_lock() magic. | |
1814 | */ | |
1815 | void perf_event_disable(struct perf_event *event) | |
1816 | { | |
1817 | struct perf_event_context *ctx; | |
1818 | ||
1819 | ctx = perf_event_ctx_lock(event); | |
1820 | _perf_event_disable(event); | |
1821 | perf_event_ctx_unlock(event, ctx); | |
1822 | } | |
dcfce4a0 | 1823 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1824 | |
e5d1367f SE |
1825 | static void perf_set_shadow_time(struct perf_event *event, |
1826 | struct perf_event_context *ctx, | |
1827 | u64 tstamp) | |
1828 | { | |
1829 | /* | |
1830 | * use the correct time source for the time snapshot | |
1831 | * | |
1832 | * We could get by without this by leveraging the | |
1833 | * fact that to get to this function, the caller | |
1834 | * has most likely already called update_context_time() | |
1835 | * and update_cgrp_time_xx() and thus both timestamp | |
1836 | * are identical (or very close). Given that tstamp is, | |
1837 | * already adjusted for cgroup, we could say that: | |
1838 | * tstamp - ctx->timestamp | |
1839 | * is equivalent to | |
1840 | * tstamp - cgrp->timestamp. | |
1841 | * | |
1842 | * Then, in perf_output_read(), the calculation would | |
1843 | * work with no changes because: | |
1844 | * - event is guaranteed scheduled in | |
1845 | * - no scheduled out in between | |
1846 | * - thus the timestamp would be the same | |
1847 | * | |
1848 | * But this is a bit hairy. | |
1849 | * | |
1850 | * So instead, we have an explicit cgroup call to remain | |
1851 | * within the time time source all along. We believe it | |
1852 | * is cleaner and simpler to understand. | |
1853 | */ | |
1854 | if (is_cgroup_event(event)) | |
1855 | perf_cgroup_set_shadow_time(event, tstamp); | |
1856 | else | |
1857 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1858 | } | |
1859 | ||
4fe757dd PZ |
1860 | #define MAX_INTERRUPTS (~0ULL) |
1861 | ||
1862 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1863 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1864 | |
235c7fc7 | 1865 | static int |
9ffcfa6f | 1866 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1867 | struct perf_cpu_context *cpuctx, |
6e37738a | 1868 | struct perf_event_context *ctx) |
235c7fc7 | 1869 | { |
4158755d | 1870 | u64 tstamp = perf_event_time(event); |
44377277 | 1871 | int ret = 0; |
4158755d | 1872 | |
63342411 PZ |
1873 | lockdep_assert_held(&ctx->lock); |
1874 | ||
cdd6c482 | 1875 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1876 | return 0; |
1877 | ||
cdd6c482 | 1878 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1879 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1880 | |
1881 | /* | |
1882 | * Unthrottle events, since we scheduled we might have missed several | |
1883 | * ticks already, also for a heavily scheduling task there is little | |
1884 | * guarantee it'll get a tick in a timely manner. | |
1885 | */ | |
1886 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1887 | perf_log_throttle(event, 1); | |
1888 | event->hw.interrupts = 0; | |
1889 | } | |
1890 | ||
235c7fc7 IM |
1891 | /* |
1892 | * The new state must be visible before we turn it on in the hardware: | |
1893 | */ | |
1894 | smp_wmb(); | |
1895 | ||
44377277 AS |
1896 | perf_pmu_disable(event->pmu); |
1897 | ||
72f669c0 SL |
1898 | perf_set_shadow_time(event, ctx, tstamp); |
1899 | ||
ec0d7729 AS |
1900 | perf_log_itrace_start(event); |
1901 | ||
a4eaf7f1 | 1902 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1903 | event->state = PERF_EVENT_STATE_INACTIVE; |
1904 | event->oncpu = -1; | |
44377277 AS |
1905 | ret = -EAGAIN; |
1906 | goto out; | |
235c7fc7 IM |
1907 | } |
1908 | ||
00a2916f PZ |
1909 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1910 | ||
cdd6c482 | 1911 | if (!is_software_event(event)) |
3b6f9e5c | 1912 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1913 | if (!ctx->nr_active++) |
1914 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1915 | if (event->attr.freq && event->attr.sample_freq) |
1916 | ctx->nr_freq++; | |
235c7fc7 | 1917 | |
cdd6c482 | 1918 | if (event->attr.exclusive) |
3b6f9e5c PM |
1919 | cpuctx->exclusive = 1; |
1920 | ||
fadfe7be JO |
1921 | if (is_orphaned_child(event)) |
1922 | schedule_orphans_remove(ctx); | |
1923 | ||
44377277 AS |
1924 | out: |
1925 | perf_pmu_enable(event->pmu); | |
1926 | ||
1927 | return ret; | |
235c7fc7 IM |
1928 | } |
1929 | ||
6751b71e | 1930 | static int |
cdd6c482 | 1931 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1932 | struct perf_cpu_context *cpuctx, |
6e37738a | 1933 | struct perf_event_context *ctx) |
6751b71e | 1934 | { |
6bde9b6c | 1935 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1936 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1937 | u64 now = ctx->time; |
1938 | bool simulate = false; | |
6751b71e | 1939 | |
cdd6c482 | 1940 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1941 | return 0; |
1942 | ||
fbbe0701 | 1943 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1944 | |
9ffcfa6f | 1945 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1946 | pmu->cancel_txn(pmu); |
272325c4 | 1947 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1948 | return -EAGAIN; |
90151c35 | 1949 | } |
6751b71e PM |
1950 | |
1951 | /* | |
1952 | * Schedule in siblings as one group (if any): | |
1953 | */ | |
cdd6c482 | 1954 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1955 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1956 | partial_group = event; |
6751b71e PM |
1957 | goto group_error; |
1958 | } | |
1959 | } | |
1960 | ||
9ffcfa6f | 1961 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1962 | return 0; |
9ffcfa6f | 1963 | |
6751b71e PM |
1964 | group_error: |
1965 | /* | |
1966 | * Groups can be scheduled in as one unit only, so undo any | |
1967 | * partial group before returning: | |
d7842da4 SE |
1968 | * The events up to the failed event are scheduled out normally, |
1969 | * tstamp_stopped will be updated. | |
1970 | * | |
1971 | * The failed events and the remaining siblings need to have | |
1972 | * their timings updated as if they had gone thru event_sched_in() | |
1973 | * and event_sched_out(). This is required to get consistent timings | |
1974 | * across the group. This also takes care of the case where the group | |
1975 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1976 | * the time the event was actually stopped, such that time delta | |
1977 | * calculation in update_event_times() is correct. | |
6751b71e | 1978 | */ |
cdd6c482 IM |
1979 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
1980 | if (event == partial_group) | |
d7842da4 SE |
1981 | simulate = true; |
1982 | ||
1983 | if (simulate) { | |
1984 | event->tstamp_running += now - event->tstamp_stopped; | |
1985 | event->tstamp_stopped = now; | |
1986 | } else { | |
1987 | event_sched_out(event, cpuctx, ctx); | |
1988 | } | |
6751b71e | 1989 | } |
9ffcfa6f | 1990 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 1991 | |
ad5133b7 | 1992 | pmu->cancel_txn(pmu); |
90151c35 | 1993 | |
272325c4 | 1994 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 1995 | |
6751b71e PM |
1996 | return -EAGAIN; |
1997 | } | |
1998 | ||
3b6f9e5c | 1999 | /* |
cdd6c482 | 2000 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2001 | */ |
cdd6c482 | 2002 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2003 | struct perf_cpu_context *cpuctx, |
2004 | int can_add_hw) | |
2005 | { | |
2006 | /* | |
cdd6c482 | 2007 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2008 | */ |
d6f962b5 | 2009 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2010 | return 1; |
2011 | /* | |
2012 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2013 | * events can go on. |
3b6f9e5c PM |
2014 | */ |
2015 | if (cpuctx->exclusive) | |
2016 | return 0; | |
2017 | /* | |
2018 | * If this group is exclusive and there are already | |
cdd6c482 | 2019 | * events on the CPU, it can't go on. |
3b6f9e5c | 2020 | */ |
cdd6c482 | 2021 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2022 | return 0; |
2023 | /* | |
2024 | * Otherwise, try to add it if all previous groups were able | |
2025 | * to go on. | |
2026 | */ | |
2027 | return can_add_hw; | |
2028 | } | |
2029 | ||
cdd6c482 IM |
2030 | static void add_event_to_ctx(struct perf_event *event, |
2031 | struct perf_event_context *ctx) | |
53cfbf59 | 2032 | { |
4158755d SE |
2033 | u64 tstamp = perf_event_time(event); |
2034 | ||
cdd6c482 | 2035 | list_add_event(event, ctx); |
8a49542c | 2036 | perf_group_attach(event); |
4158755d SE |
2037 | event->tstamp_enabled = tstamp; |
2038 | event->tstamp_running = tstamp; | |
2039 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2040 | } |
2041 | ||
2c29ef0f PZ |
2042 | static void task_ctx_sched_out(struct perf_event_context *ctx); |
2043 | static void | |
2044 | ctx_sched_in(struct perf_event_context *ctx, | |
2045 | struct perf_cpu_context *cpuctx, | |
2046 | enum event_type_t event_type, | |
2047 | struct task_struct *task); | |
fe4b04fa | 2048 | |
dce5855b PZ |
2049 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2050 | struct perf_event_context *ctx, | |
2051 | struct task_struct *task) | |
2052 | { | |
2053 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2054 | if (ctx) | |
2055 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2056 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2057 | if (ctx) | |
2058 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2059 | } | |
2060 | ||
0017960f PZ |
2061 | static void ___perf_install_in_context(void *info) |
2062 | { | |
2063 | struct perf_event *event = info; | |
2064 | struct perf_event_context *ctx = event->ctx; | |
2065 | ||
2066 | /* | |
2067 | * Since the task isn't running, its safe to add the event, us holding | |
2068 | * the ctx->lock ensures the task won't get scheduled in. | |
2069 | */ | |
2070 | add_event_to_ctx(event, ctx); | |
2071 | } | |
2072 | ||
0793a61d | 2073 | /* |
cdd6c482 | 2074 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2075 | * |
2076 | * Must be called with ctx->mutex held | |
0793a61d | 2077 | */ |
fe4b04fa | 2078 | static int __perf_install_in_context(void *info) |
0793a61d | 2079 | { |
cdd6c482 IM |
2080 | struct perf_event *event = info; |
2081 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2082 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f PZ |
2083 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
2084 | struct task_struct *task = current; | |
2085 | ||
b58f6b0d | 2086 | perf_ctx_lock(cpuctx, task_ctx); |
2c29ef0f | 2087 | perf_pmu_disable(cpuctx->ctx.pmu); |
0793a61d TG |
2088 | |
2089 | /* | |
2c29ef0f | 2090 | * If there was an active task_ctx schedule it out. |
0793a61d | 2091 | */ |
b58f6b0d | 2092 | if (task_ctx) |
2c29ef0f | 2093 | task_ctx_sched_out(task_ctx); |
b58f6b0d PZ |
2094 | |
2095 | /* | |
2096 | * If the context we're installing events in is not the | |
2097 | * active task_ctx, flip them. | |
2098 | */ | |
2099 | if (ctx->task && task_ctx != ctx) { | |
2100 | if (task_ctx) | |
2101 | raw_spin_unlock(&task_ctx->lock); | |
2102 | raw_spin_lock(&ctx->lock); | |
2103 | task_ctx = ctx; | |
2104 | } | |
2105 | ||
2106 | if (task_ctx) { | |
2107 | cpuctx->task_ctx = task_ctx; | |
2c29ef0f PZ |
2108 | task = task_ctx->task; |
2109 | } | |
b58f6b0d | 2110 | |
2c29ef0f | 2111 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); |
0793a61d | 2112 | |
4af4998b | 2113 | update_context_time(ctx); |
e5d1367f SE |
2114 | /* |
2115 | * update cgrp time only if current cgrp | |
2116 | * matches event->cgrp. Must be done before | |
2117 | * calling add_event_to_ctx() | |
2118 | */ | |
2119 | update_cgrp_time_from_event(event); | |
0793a61d | 2120 | |
cdd6c482 | 2121 | add_event_to_ctx(event, ctx); |
0793a61d | 2122 | |
d859e29f | 2123 | /* |
2c29ef0f | 2124 | * Schedule everything back in |
d859e29f | 2125 | */ |
dce5855b | 2126 | perf_event_sched_in(cpuctx, task_ctx, task); |
2c29ef0f PZ |
2127 | |
2128 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2129 | perf_ctx_unlock(cpuctx, task_ctx); | |
fe4b04fa PZ |
2130 | |
2131 | return 0; | |
0793a61d TG |
2132 | } |
2133 | ||
2134 | /* | |
cdd6c482 | 2135 | * Attach a performance event to a context |
0793a61d | 2136 | * |
cdd6c482 IM |
2137 | * First we add the event to the list with the hardware enable bit |
2138 | * in event->hw_config cleared. | |
0793a61d | 2139 | * |
cdd6c482 | 2140 | * If the event is attached to a task which is on a CPU we use a smp |
0793a61d TG |
2141 | * call to enable it in the task context. The task might have been |
2142 | * scheduled away, but we check this in the smp call again. | |
2143 | */ | |
2144 | static void | |
cdd6c482 IM |
2145 | perf_install_in_context(struct perf_event_context *ctx, |
2146 | struct perf_event *event, | |
0793a61d TG |
2147 | int cpu) |
2148 | { | |
fe4b04fa PZ |
2149 | lockdep_assert_held(&ctx->mutex); |
2150 | ||
c3f00c70 | 2151 | event->ctx = ctx; |
0cda4c02 YZ |
2152 | if (event->cpu != -1) |
2153 | event->cpu = cpu; | |
c3f00c70 | 2154 | |
0017960f PZ |
2155 | event_function_call(event, __perf_install_in_context, |
2156 | ___perf_install_in_context, event); | |
0793a61d TG |
2157 | } |
2158 | ||
fa289bec | 2159 | /* |
cdd6c482 | 2160 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2161 | * Enabling the leader of a group effectively enables all |
2162 | * the group members that aren't explicitly disabled, so we | |
2163 | * have to update their ->tstamp_enabled also. | |
2164 | * Note: this works for group members as well as group leaders | |
2165 | * since the non-leader members' sibling_lists will be empty. | |
2166 | */ | |
1d9b482e | 2167 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2168 | { |
cdd6c482 | 2169 | struct perf_event *sub; |
4158755d | 2170 | u64 tstamp = perf_event_time(event); |
fa289bec | 2171 | |
cdd6c482 | 2172 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2173 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2174 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2175 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2176 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2177 | } |
fa289bec PM |
2178 | } |
2179 | ||
d859e29f | 2180 | /* |
cdd6c482 | 2181 | * Cross CPU call to enable a performance event |
d859e29f | 2182 | */ |
fe4b04fa | 2183 | static int __perf_event_enable(void *info) |
04289bb9 | 2184 | { |
cdd6c482 | 2185 | struct perf_event *event = info; |
cdd6c482 IM |
2186 | struct perf_event_context *ctx = event->ctx; |
2187 | struct perf_event *leader = event->group_leader; | |
108b02cf | 2188 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f | 2189 | int err; |
04289bb9 | 2190 | |
06f41796 JO |
2191 | /* |
2192 | * There's a time window between 'ctx->is_active' check | |
2193 | * in perf_event_enable function and this place having: | |
2194 | * - IRQs on | |
2195 | * - ctx->lock unlocked | |
2196 | * | |
2197 | * where the task could be killed and 'ctx' deactivated | |
2198 | * by perf_event_exit_task. | |
2199 | */ | |
2200 | if (!ctx->is_active) | |
fe4b04fa | 2201 | return -EINVAL; |
3cbed429 | 2202 | |
e625cce1 | 2203 | raw_spin_lock(&ctx->lock); |
4af4998b | 2204 | update_context_time(ctx); |
d859e29f | 2205 | |
cdd6c482 | 2206 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f | 2207 | goto unlock; |
e5d1367f SE |
2208 | |
2209 | /* | |
2210 | * set current task's cgroup time reference point | |
2211 | */ | |
3f7cce3c | 2212 | perf_cgroup_set_timestamp(current, ctx); |
e5d1367f | 2213 | |
1d9b482e | 2214 | __perf_event_mark_enabled(event); |
04289bb9 | 2215 | |
e5d1367f SE |
2216 | if (!event_filter_match(event)) { |
2217 | if (is_cgroup_event(event)) | |
2218 | perf_cgroup_defer_enabled(event); | |
f4c4176f | 2219 | goto unlock; |
e5d1367f | 2220 | } |
f4c4176f | 2221 | |
04289bb9 | 2222 | /* |
cdd6c482 | 2223 | * If the event is in a group and isn't the group leader, |
d859e29f | 2224 | * then don't put it on unless the group is on. |
04289bb9 | 2225 | */ |
cdd6c482 | 2226 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
d859e29f | 2227 | goto unlock; |
3b6f9e5c | 2228 | |
cdd6c482 | 2229 | if (!group_can_go_on(event, cpuctx, 1)) { |
d859e29f | 2230 | err = -EEXIST; |
e758a33d | 2231 | } else { |
cdd6c482 | 2232 | if (event == leader) |
6e37738a | 2233 | err = group_sched_in(event, cpuctx, ctx); |
e758a33d | 2234 | else |
6e37738a | 2235 | err = event_sched_in(event, cpuctx, ctx); |
e758a33d | 2236 | } |
d859e29f PM |
2237 | |
2238 | if (err) { | |
2239 | /* | |
cdd6c482 | 2240 | * If this event can't go on and it's part of a |
d859e29f PM |
2241 | * group, then the whole group has to come off. |
2242 | */ | |
9e630205 | 2243 | if (leader != event) { |
d859e29f | 2244 | group_sched_out(leader, cpuctx, ctx); |
272325c4 | 2245 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2246 | } |
0d48696f | 2247 | if (leader->attr.pinned) { |
53cfbf59 | 2248 | update_group_times(leader); |
cdd6c482 | 2249 | leader->state = PERF_EVENT_STATE_ERROR; |
53cfbf59 | 2250 | } |
d859e29f PM |
2251 | } |
2252 | ||
9ed6060d | 2253 | unlock: |
e625cce1 | 2254 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
2255 | |
2256 | return 0; | |
d859e29f PM |
2257 | } |
2258 | ||
7b648018 PZ |
2259 | void ___perf_event_enable(void *info) |
2260 | { | |
2261 | __perf_event_mark_enabled((struct perf_event *)info); | |
2262 | } | |
2263 | ||
d859e29f | 2264 | /* |
cdd6c482 | 2265 | * Enable a event. |
c93f7669 | 2266 | * |
cdd6c482 IM |
2267 | * If event->ctx is a cloned context, callers must make sure that |
2268 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2269 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2270 | * perf_event_for_each_child or perf_event_for_each as described |
2271 | * for perf_event_disable. | |
d859e29f | 2272 | */ |
f63a8daa | 2273 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2274 | { |
cdd6c482 | 2275 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2276 | |
7b648018 PZ |
2277 | raw_spin_lock_irq(&ctx->lock); |
2278 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
2279 | raw_spin_unlock_irq(&ctx->lock); | |
d859e29f PM |
2280 | return; |
2281 | } | |
2282 | ||
d859e29f | 2283 | /* |
cdd6c482 | 2284 | * If the event is in error state, clear that first. |
7b648018 PZ |
2285 | * |
2286 | * That way, if we see the event in error state below, we know that it | |
2287 | * has gone back into error state, as distinct from the task having | |
2288 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2289 | */ |
cdd6c482 IM |
2290 | if (event->state == PERF_EVENT_STATE_ERROR) |
2291 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2292 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2293 | |
7b648018 PZ |
2294 | event_function_call(event, __perf_event_enable, |
2295 | ___perf_event_enable, event); | |
d859e29f | 2296 | } |
f63a8daa PZ |
2297 | |
2298 | /* | |
2299 | * See perf_event_disable(); | |
2300 | */ | |
2301 | void perf_event_enable(struct perf_event *event) | |
2302 | { | |
2303 | struct perf_event_context *ctx; | |
2304 | ||
2305 | ctx = perf_event_ctx_lock(event); | |
2306 | _perf_event_enable(event); | |
2307 | perf_event_ctx_unlock(event, ctx); | |
2308 | } | |
dcfce4a0 | 2309 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2310 | |
f63a8daa | 2311 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2312 | { |
2023b359 | 2313 | /* |
cdd6c482 | 2314 | * not supported on inherited events |
2023b359 | 2315 | */ |
2e939d1d | 2316 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2317 | return -EINVAL; |
2318 | ||
cdd6c482 | 2319 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2320 | _perf_event_enable(event); |
2023b359 PZ |
2321 | |
2322 | return 0; | |
79f14641 | 2323 | } |
f63a8daa PZ |
2324 | |
2325 | /* | |
2326 | * See perf_event_disable() | |
2327 | */ | |
2328 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2329 | { | |
2330 | struct perf_event_context *ctx; | |
2331 | int ret; | |
2332 | ||
2333 | ctx = perf_event_ctx_lock(event); | |
2334 | ret = _perf_event_refresh(event, refresh); | |
2335 | perf_event_ctx_unlock(event, ctx); | |
2336 | ||
2337 | return ret; | |
2338 | } | |
26ca5c11 | 2339 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2340 | |
5b0311e1 FW |
2341 | static void ctx_sched_out(struct perf_event_context *ctx, |
2342 | struct perf_cpu_context *cpuctx, | |
2343 | enum event_type_t event_type) | |
235c7fc7 | 2344 | { |
cdd6c482 | 2345 | struct perf_event *event; |
db24d33e | 2346 | int is_active = ctx->is_active; |
235c7fc7 | 2347 | |
db24d33e | 2348 | ctx->is_active &= ~event_type; |
cdd6c482 | 2349 | if (likely(!ctx->nr_events)) |
facc4307 PZ |
2350 | return; |
2351 | ||
4af4998b | 2352 | update_context_time(ctx); |
e5d1367f | 2353 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2354 | if (!ctx->nr_active) |
facc4307 | 2355 | return; |
5b0311e1 | 2356 | |
075e0b00 | 2357 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2358 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2359 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2360 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2361 | } |
889ff015 | 2362 | |
db24d33e | 2363 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2364 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2365 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2366 | } |
1b9a644f | 2367 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2368 | } |
2369 | ||
564c2b21 | 2370 | /* |
5a3126d4 PZ |
2371 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2372 | * cloned from the same version of the same context. | |
2373 | * | |
2374 | * Equivalence is measured using a generation number in the context that is | |
2375 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2376 | * and list_del_event(). | |
564c2b21 | 2377 | */ |
cdd6c482 IM |
2378 | static int context_equiv(struct perf_event_context *ctx1, |
2379 | struct perf_event_context *ctx2) | |
564c2b21 | 2380 | { |
211de6eb PZ |
2381 | lockdep_assert_held(&ctx1->lock); |
2382 | lockdep_assert_held(&ctx2->lock); | |
2383 | ||
5a3126d4 PZ |
2384 | /* Pinning disables the swap optimization */ |
2385 | if (ctx1->pin_count || ctx2->pin_count) | |
2386 | return 0; | |
2387 | ||
2388 | /* If ctx1 is the parent of ctx2 */ | |
2389 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2390 | return 1; | |
2391 | ||
2392 | /* If ctx2 is the parent of ctx1 */ | |
2393 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2394 | return 1; | |
2395 | ||
2396 | /* | |
2397 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2398 | * hierarchy, see perf_event_init_context(). | |
2399 | */ | |
2400 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2401 | ctx1->parent_gen == ctx2->parent_gen) | |
2402 | return 1; | |
2403 | ||
2404 | /* Unmatched */ | |
2405 | return 0; | |
564c2b21 PM |
2406 | } |
2407 | ||
cdd6c482 IM |
2408 | static void __perf_event_sync_stat(struct perf_event *event, |
2409 | struct perf_event *next_event) | |
bfbd3381 PZ |
2410 | { |
2411 | u64 value; | |
2412 | ||
cdd6c482 | 2413 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2414 | return; |
2415 | ||
2416 | /* | |
cdd6c482 | 2417 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2418 | * because we're in the middle of a context switch and have IRQs |
2419 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2420 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2421 | * don't need to use it. |
2422 | */ | |
cdd6c482 IM |
2423 | switch (event->state) { |
2424 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2425 | event->pmu->read(event); |
2426 | /* fall-through */ | |
bfbd3381 | 2427 | |
cdd6c482 IM |
2428 | case PERF_EVENT_STATE_INACTIVE: |
2429 | update_event_times(event); | |
bfbd3381 PZ |
2430 | break; |
2431 | ||
2432 | default: | |
2433 | break; | |
2434 | } | |
2435 | ||
2436 | /* | |
cdd6c482 | 2437 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2438 | * values when we flip the contexts. |
2439 | */ | |
e7850595 PZ |
2440 | value = local64_read(&next_event->count); |
2441 | value = local64_xchg(&event->count, value); | |
2442 | local64_set(&next_event->count, value); | |
bfbd3381 | 2443 | |
cdd6c482 IM |
2444 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2445 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2446 | |
bfbd3381 | 2447 | /* |
19d2e755 | 2448 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2449 | */ |
cdd6c482 IM |
2450 | perf_event_update_userpage(event); |
2451 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2452 | } |
2453 | ||
cdd6c482 IM |
2454 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2455 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2456 | { |
cdd6c482 | 2457 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2458 | |
2459 | if (!ctx->nr_stat) | |
2460 | return; | |
2461 | ||
02ffdbc8 PZ |
2462 | update_context_time(ctx); |
2463 | ||
cdd6c482 IM |
2464 | event = list_first_entry(&ctx->event_list, |
2465 | struct perf_event, event_entry); | |
bfbd3381 | 2466 | |
cdd6c482 IM |
2467 | next_event = list_first_entry(&next_ctx->event_list, |
2468 | struct perf_event, event_entry); | |
bfbd3381 | 2469 | |
cdd6c482 IM |
2470 | while (&event->event_entry != &ctx->event_list && |
2471 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2472 | |
cdd6c482 | 2473 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2474 | |
cdd6c482 IM |
2475 | event = list_next_entry(event, event_entry); |
2476 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2477 | } |
2478 | } | |
2479 | ||
fe4b04fa PZ |
2480 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2481 | struct task_struct *next) | |
0793a61d | 2482 | { |
8dc85d54 | 2483 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2484 | struct perf_event_context *next_ctx; |
5a3126d4 | 2485 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2486 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2487 | int do_switch = 1; |
0793a61d | 2488 | |
108b02cf PZ |
2489 | if (likely(!ctx)) |
2490 | return; | |
10989fb2 | 2491 | |
108b02cf PZ |
2492 | cpuctx = __get_cpu_context(ctx); |
2493 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2494 | return; |
2495 | ||
c93f7669 | 2496 | rcu_read_lock(); |
8dc85d54 | 2497 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2498 | if (!next_ctx) |
2499 | goto unlock; | |
2500 | ||
2501 | parent = rcu_dereference(ctx->parent_ctx); | |
2502 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2503 | ||
2504 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2505 | if (!parent && !next_parent) |
5a3126d4 PZ |
2506 | goto unlock; |
2507 | ||
2508 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2509 | /* |
2510 | * Looks like the two contexts are clones, so we might be | |
2511 | * able to optimize the context switch. We lock both | |
2512 | * contexts and check that they are clones under the | |
2513 | * lock (including re-checking that neither has been | |
2514 | * uncloned in the meantime). It doesn't matter which | |
2515 | * order we take the locks because no other cpu could | |
2516 | * be trying to lock both of these tasks. | |
2517 | */ | |
e625cce1 TG |
2518 | raw_spin_lock(&ctx->lock); |
2519 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2520 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2521 | /* |
2522 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2523 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2524 | */ |
8dc85d54 PZ |
2525 | task->perf_event_ctxp[ctxn] = next_ctx; |
2526 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2527 | ctx->task = next; |
2528 | next_ctx->task = task; | |
5a158c3c YZ |
2529 | |
2530 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2531 | ||
c93f7669 | 2532 | do_switch = 0; |
bfbd3381 | 2533 | |
cdd6c482 | 2534 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2535 | } |
e625cce1 TG |
2536 | raw_spin_unlock(&next_ctx->lock); |
2537 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2538 | } |
5a3126d4 | 2539 | unlock: |
c93f7669 | 2540 | rcu_read_unlock(); |
564c2b21 | 2541 | |
c93f7669 | 2542 | if (do_switch) { |
facc4307 | 2543 | raw_spin_lock(&ctx->lock); |
5b0311e1 | 2544 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
c93f7669 | 2545 | cpuctx->task_ctx = NULL; |
facc4307 | 2546 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2547 | } |
0793a61d TG |
2548 | } |
2549 | ||
ba532500 YZ |
2550 | void perf_sched_cb_dec(struct pmu *pmu) |
2551 | { | |
2552 | this_cpu_dec(perf_sched_cb_usages); | |
2553 | } | |
2554 | ||
2555 | void perf_sched_cb_inc(struct pmu *pmu) | |
2556 | { | |
2557 | this_cpu_inc(perf_sched_cb_usages); | |
2558 | } | |
2559 | ||
2560 | /* | |
2561 | * This function provides the context switch callback to the lower code | |
2562 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2563 | */ | |
2564 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2565 | struct task_struct *next, | |
2566 | bool sched_in) | |
2567 | { | |
2568 | struct perf_cpu_context *cpuctx; | |
2569 | struct pmu *pmu; | |
2570 | unsigned long flags; | |
2571 | ||
2572 | if (prev == next) | |
2573 | return; | |
2574 | ||
2575 | local_irq_save(flags); | |
2576 | ||
2577 | rcu_read_lock(); | |
2578 | ||
2579 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2580 | if (pmu->sched_task) { | |
2581 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2582 | ||
2583 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2584 | ||
2585 | perf_pmu_disable(pmu); | |
2586 | ||
2587 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2588 | ||
2589 | perf_pmu_enable(pmu); | |
2590 | ||
2591 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2592 | } | |
2593 | } | |
2594 | ||
2595 | rcu_read_unlock(); | |
2596 | ||
2597 | local_irq_restore(flags); | |
2598 | } | |
2599 | ||
45ac1403 AH |
2600 | static void perf_event_switch(struct task_struct *task, |
2601 | struct task_struct *next_prev, bool sched_in); | |
2602 | ||
8dc85d54 PZ |
2603 | #define for_each_task_context_nr(ctxn) \ |
2604 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2605 | ||
2606 | /* | |
2607 | * Called from scheduler to remove the events of the current task, | |
2608 | * with interrupts disabled. | |
2609 | * | |
2610 | * We stop each event and update the event value in event->count. | |
2611 | * | |
2612 | * This does not protect us against NMI, but disable() | |
2613 | * sets the disabled bit in the control field of event _before_ | |
2614 | * accessing the event control register. If a NMI hits, then it will | |
2615 | * not restart the event. | |
2616 | */ | |
ab0cce56 JO |
2617 | void __perf_event_task_sched_out(struct task_struct *task, |
2618 | struct task_struct *next) | |
8dc85d54 PZ |
2619 | { |
2620 | int ctxn; | |
2621 | ||
ba532500 YZ |
2622 | if (__this_cpu_read(perf_sched_cb_usages)) |
2623 | perf_pmu_sched_task(task, next, false); | |
2624 | ||
45ac1403 AH |
2625 | if (atomic_read(&nr_switch_events)) |
2626 | perf_event_switch(task, next, false); | |
2627 | ||
8dc85d54 PZ |
2628 | for_each_task_context_nr(ctxn) |
2629 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2630 | |
2631 | /* | |
2632 | * if cgroup events exist on this CPU, then we need | |
2633 | * to check if we have to switch out PMU state. | |
2634 | * cgroup event are system-wide mode only | |
2635 | */ | |
4a32fea9 | 2636 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2637 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2638 | } |
2639 | ||
04dc2dbb | 2640 | static void task_ctx_sched_out(struct perf_event_context *ctx) |
a08b159f | 2641 | { |
108b02cf | 2642 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
a08b159f | 2643 | |
a63eaf34 PM |
2644 | if (!cpuctx->task_ctx) |
2645 | return; | |
012b84da IM |
2646 | |
2647 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2648 | return; | |
2649 | ||
04dc2dbb | 2650 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2651 | cpuctx->task_ctx = NULL; |
2652 | } | |
2653 | ||
5b0311e1 FW |
2654 | /* |
2655 | * Called with IRQs disabled | |
2656 | */ | |
2657 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2658 | enum event_type_t event_type) | |
2659 | { | |
2660 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2661 | } |
2662 | ||
235c7fc7 | 2663 | static void |
5b0311e1 | 2664 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2665 | struct perf_cpu_context *cpuctx) |
0793a61d | 2666 | { |
cdd6c482 | 2667 | struct perf_event *event; |
0793a61d | 2668 | |
889ff015 FW |
2669 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2670 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2671 | continue; |
5632ab12 | 2672 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2673 | continue; |
2674 | ||
e5d1367f SE |
2675 | /* may need to reset tstamp_enabled */ |
2676 | if (is_cgroup_event(event)) | |
2677 | perf_cgroup_mark_enabled(event, ctx); | |
2678 | ||
8c9ed8e1 | 2679 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2680 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2681 | |
2682 | /* | |
2683 | * If this pinned group hasn't been scheduled, | |
2684 | * put it in error state. | |
2685 | */ | |
cdd6c482 IM |
2686 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2687 | update_group_times(event); | |
2688 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2689 | } |
3b6f9e5c | 2690 | } |
5b0311e1 FW |
2691 | } |
2692 | ||
2693 | static void | |
2694 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2695 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2696 | { |
2697 | struct perf_event *event; | |
2698 | int can_add_hw = 1; | |
3b6f9e5c | 2699 | |
889ff015 FW |
2700 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2701 | /* Ignore events in OFF or ERROR state */ | |
2702 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2703 | continue; |
04289bb9 IM |
2704 | /* |
2705 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2706 | * of events: |
04289bb9 | 2707 | */ |
5632ab12 | 2708 | if (!event_filter_match(event)) |
0793a61d TG |
2709 | continue; |
2710 | ||
e5d1367f SE |
2711 | /* may need to reset tstamp_enabled */ |
2712 | if (is_cgroup_event(event)) | |
2713 | perf_cgroup_mark_enabled(event, ctx); | |
2714 | ||
9ed6060d | 2715 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2716 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2717 | can_add_hw = 0; |
9ed6060d | 2718 | } |
0793a61d | 2719 | } |
5b0311e1 FW |
2720 | } |
2721 | ||
2722 | static void | |
2723 | ctx_sched_in(struct perf_event_context *ctx, | |
2724 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2725 | enum event_type_t event_type, |
2726 | struct task_struct *task) | |
5b0311e1 | 2727 | { |
e5d1367f | 2728 | u64 now; |
db24d33e | 2729 | int is_active = ctx->is_active; |
e5d1367f | 2730 | |
db24d33e | 2731 | ctx->is_active |= event_type; |
5b0311e1 | 2732 | if (likely(!ctx->nr_events)) |
facc4307 | 2733 | return; |
5b0311e1 | 2734 | |
e5d1367f SE |
2735 | now = perf_clock(); |
2736 | ctx->timestamp = now; | |
3f7cce3c | 2737 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2738 | /* |
2739 | * First go through the list and put on any pinned groups | |
2740 | * in order to give them the best chance of going on. | |
2741 | */ | |
db24d33e | 2742 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2743 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2744 | |
2745 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2746 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2747 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2748 | } |
2749 | ||
329c0e01 | 2750 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2751 | enum event_type_t event_type, |
2752 | struct task_struct *task) | |
329c0e01 FW |
2753 | { |
2754 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2755 | ||
e5d1367f | 2756 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2757 | } |
2758 | ||
e5d1367f SE |
2759 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2760 | struct task_struct *task) | |
235c7fc7 | 2761 | { |
108b02cf | 2762 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2763 | |
108b02cf | 2764 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2765 | if (cpuctx->task_ctx == ctx) |
2766 | return; | |
2767 | ||
facc4307 | 2768 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2769 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2770 | /* |
2771 | * We want to keep the following priority order: | |
2772 | * cpu pinned (that don't need to move), task pinned, | |
2773 | * cpu flexible, task flexible. | |
2774 | */ | |
2775 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2776 | ||
1d5f003f GN |
2777 | if (ctx->nr_events) |
2778 | cpuctx->task_ctx = ctx; | |
9b33fa6b | 2779 | |
86b47c25 GN |
2780 | perf_event_sched_in(cpuctx, cpuctx->task_ctx, task); |
2781 | ||
facc4307 PZ |
2782 | perf_pmu_enable(ctx->pmu); |
2783 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2784 | } |
2785 | ||
8dc85d54 PZ |
2786 | /* |
2787 | * Called from scheduler to add the events of the current task | |
2788 | * with interrupts disabled. | |
2789 | * | |
2790 | * We restore the event value and then enable it. | |
2791 | * | |
2792 | * This does not protect us against NMI, but enable() | |
2793 | * sets the enabled bit in the control field of event _before_ | |
2794 | * accessing the event control register. If a NMI hits, then it will | |
2795 | * keep the event running. | |
2796 | */ | |
ab0cce56 JO |
2797 | void __perf_event_task_sched_in(struct task_struct *prev, |
2798 | struct task_struct *task) | |
8dc85d54 PZ |
2799 | { |
2800 | struct perf_event_context *ctx; | |
2801 | int ctxn; | |
2802 | ||
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 | } |
e5d1367f SE |
2810 | /* |
2811 | * if cgroup events exist on this CPU, then we need | |
2812 | * to check if we have to switch in PMU state. | |
2813 | * cgroup event are system-wide mode only | |
2814 | */ | |
4a32fea9 | 2815 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2816 | perf_cgroup_sched_in(prev, task); |
d010b332 | 2817 | |
45ac1403 AH |
2818 | if (atomic_read(&nr_switch_events)) |
2819 | perf_event_switch(task, prev, true); | |
2820 | ||
ba532500 YZ |
2821 | if (__this_cpu_read(perf_sched_cb_usages)) |
2822 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2823 | } |
2824 | ||
abd50713 PZ |
2825 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2826 | { | |
2827 | u64 frequency = event->attr.sample_freq; | |
2828 | u64 sec = NSEC_PER_SEC; | |
2829 | u64 divisor, dividend; | |
2830 | ||
2831 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2832 | ||
2833 | count_fls = fls64(count); | |
2834 | nsec_fls = fls64(nsec); | |
2835 | frequency_fls = fls64(frequency); | |
2836 | sec_fls = 30; | |
2837 | ||
2838 | /* | |
2839 | * We got @count in @nsec, with a target of sample_freq HZ | |
2840 | * the target period becomes: | |
2841 | * | |
2842 | * @count * 10^9 | |
2843 | * period = ------------------- | |
2844 | * @nsec * sample_freq | |
2845 | * | |
2846 | */ | |
2847 | ||
2848 | /* | |
2849 | * Reduce accuracy by one bit such that @a and @b converge | |
2850 | * to a similar magnitude. | |
2851 | */ | |
fe4b04fa | 2852 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2853 | do { \ |
2854 | if (a##_fls > b##_fls) { \ | |
2855 | a >>= 1; \ | |
2856 | a##_fls--; \ | |
2857 | } else { \ | |
2858 | b >>= 1; \ | |
2859 | b##_fls--; \ | |
2860 | } \ | |
2861 | } while (0) | |
2862 | ||
2863 | /* | |
2864 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2865 | * the other, so that finally we can do a u64/u64 division. | |
2866 | */ | |
2867 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2868 | REDUCE_FLS(nsec, frequency); | |
2869 | REDUCE_FLS(sec, count); | |
2870 | } | |
2871 | ||
2872 | if (count_fls + sec_fls > 64) { | |
2873 | divisor = nsec * frequency; | |
2874 | ||
2875 | while (count_fls + sec_fls > 64) { | |
2876 | REDUCE_FLS(count, sec); | |
2877 | divisor >>= 1; | |
2878 | } | |
2879 | ||
2880 | dividend = count * sec; | |
2881 | } else { | |
2882 | dividend = count * sec; | |
2883 | ||
2884 | while (nsec_fls + frequency_fls > 64) { | |
2885 | REDUCE_FLS(nsec, frequency); | |
2886 | dividend >>= 1; | |
2887 | } | |
2888 | ||
2889 | divisor = nsec * frequency; | |
2890 | } | |
2891 | ||
f6ab91ad PZ |
2892 | if (!divisor) |
2893 | return dividend; | |
2894 | ||
abd50713 PZ |
2895 | return div64_u64(dividend, divisor); |
2896 | } | |
2897 | ||
e050e3f0 SE |
2898 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2899 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2900 | ||
f39d47ff | 2901 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2902 | { |
cdd6c482 | 2903 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2904 | s64 period, sample_period; |
bd2b5b12 PZ |
2905 | s64 delta; |
2906 | ||
abd50713 | 2907 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2908 | |
2909 | delta = (s64)(period - hwc->sample_period); | |
2910 | delta = (delta + 7) / 8; /* low pass filter */ | |
2911 | ||
2912 | sample_period = hwc->sample_period + delta; | |
2913 | ||
2914 | if (!sample_period) | |
2915 | sample_period = 1; | |
2916 | ||
bd2b5b12 | 2917 | hwc->sample_period = sample_period; |
abd50713 | 2918 | |
e7850595 | 2919 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2920 | if (disable) |
2921 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2922 | ||
e7850595 | 2923 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2924 | |
2925 | if (disable) | |
2926 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2927 | } |
bd2b5b12 PZ |
2928 | } |
2929 | ||
e050e3f0 SE |
2930 | /* |
2931 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2932 | * events. At the same time, make sure, having freq events does not change | |
2933 | * the rate of unthrottling as that would introduce bias. | |
2934 | */ | |
2935 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2936 | int needs_unthr) | |
60db5e09 | 2937 | { |
cdd6c482 IM |
2938 | struct perf_event *event; |
2939 | struct hw_perf_event *hwc; | |
e050e3f0 | 2940 | u64 now, period = TICK_NSEC; |
abd50713 | 2941 | s64 delta; |
60db5e09 | 2942 | |
e050e3f0 SE |
2943 | /* |
2944 | * only need to iterate over all events iff: | |
2945 | * - context have events in frequency mode (needs freq adjust) | |
2946 | * - there are events to unthrottle on this cpu | |
2947 | */ | |
2948 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2949 | return; |
2950 | ||
e050e3f0 | 2951 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2952 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2953 | |
03541f8b | 2954 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2955 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2956 | continue; |
2957 | ||
5632ab12 | 2958 | if (!event_filter_match(event)) |
5d27c23d PZ |
2959 | continue; |
2960 | ||
44377277 AS |
2961 | perf_pmu_disable(event->pmu); |
2962 | ||
cdd6c482 | 2963 | hwc = &event->hw; |
6a24ed6c | 2964 | |
ae23bff1 | 2965 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2966 | hwc->interrupts = 0; |
cdd6c482 | 2967 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2968 | event->pmu->start(event, 0); |
a78ac325 PZ |
2969 | } |
2970 | ||
cdd6c482 | 2971 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2972 | goto next; |
60db5e09 | 2973 | |
e050e3f0 SE |
2974 | /* |
2975 | * stop the event and update event->count | |
2976 | */ | |
2977 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2978 | ||
e7850595 | 2979 | now = local64_read(&event->count); |
abd50713 PZ |
2980 | delta = now - hwc->freq_count_stamp; |
2981 | hwc->freq_count_stamp = now; | |
60db5e09 | 2982 | |
e050e3f0 SE |
2983 | /* |
2984 | * restart the event | |
2985 | * reload only if value has changed | |
f39d47ff SE |
2986 | * we have stopped the event so tell that |
2987 | * to perf_adjust_period() to avoid stopping it | |
2988 | * twice. | |
e050e3f0 | 2989 | */ |
abd50713 | 2990 | if (delta > 0) |
f39d47ff | 2991 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
2992 | |
2993 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
2994 | next: |
2995 | perf_pmu_enable(event->pmu); | |
60db5e09 | 2996 | } |
e050e3f0 | 2997 | |
f39d47ff | 2998 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 2999 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3000 | } |
3001 | ||
235c7fc7 | 3002 | /* |
cdd6c482 | 3003 | * Round-robin a context's events: |
235c7fc7 | 3004 | */ |
cdd6c482 | 3005 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3006 | { |
dddd3379 TG |
3007 | /* |
3008 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3009 | * disabled by the inheritance code. | |
3010 | */ | |
3011 | if (!ctx->rotate_disable) | |
3012 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3013 | } |
3014 | ||
9e630205 | 3015 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3016 | { |
8dc85d54 | 3017 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3018 | int rotate = 0; |
7fc23a53 | 3019 | |
b5ab4cd5 | 3020 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3021 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3022 | rotate = 1; | |
3023 | } | |
235c7fc7 | 3024 | |
8dc85d54 | 3025 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3026 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3027 | if (ctx->nr_events != ctx->nr_active) |
3028 | rotate = 1; | |
3029 | } | |
9717e6cd | 3030 | |
e050e3f0 | 3031 | if (!rotate) |
0f5a2601 PZ |
3032 | goto done; |
3033 | ||
facc4307 | 3034 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3035 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3036 | |
e050e3f0 SE |
3037 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3038 | if (ctx) | |
3039 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3040 | |
e050e3f0 SE |
3041 | rotate_ctx(&cpuctx->ctx); |
3042 | if (ctx) | |
3043 | rotate_ctx(ctx); | |
235c7fc7 | 3044 | |
e050e3f0 | 3045 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3046 | |
0f5a2601 PZ |
3047 | perf_pmu_enable(cpuctx->ctx.pmu); |
3048 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3049 | done: |
9e630205 SE |
3050 | |
3051 | return rotate; | |
e9d2b064 PZ |
3052 | } |
3053 | ||
026249ef FW |
3054 | #ifdef CONFIG_NO_HZ_FULL |
3055 | bool perf_event_can_stop_tick(void) | |
3056 | { | |
948b26b6 | 3057 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3058 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3059 | return false; |
d84153d6 FW |
3060 | else |
3061 | return true; | |
026249ef FW |
3062 | } |
3063 | #endif | |
3064 | ||
e9d2b064 PZ |
3065 | void perf_event_task_tick(void) |
3066 | { | |
2fde4f94 MR |
3067 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3068 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3069 | int throttled; |
b5ab4cd5 | 3070 | |
e9d2b064 PZ |
3071 | WARN_ON(!irqs_disabled()); |
3072 | ||
e050e3f0 SE |
3073 | __this_cpu_inc(perf_throttled_seq); |
3074 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3075 | ||
2fde4f94 | 3076 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3077 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3078 | } |
3079 | ||
889ff015 FW |
3080 | static int event_enable_on_exec(struct perf_event *event, |
3081 | struct perf_event_context *ctx) | |
3082 | { | |
3083 | if (!event->attr.enable_on_exec) | |
3084 | return 0; | |
3085 | ||
3086 | event->attr.enable_on_exec = 0; | |
3087 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3088 | return 0; | |
3089 | ||
1d9b482e | 3090 | __perf_event_mark_enabled(event); |
889ff015 FW |
3091 | |
3092 | return 1; | |
3093 | } | |
3094 | ||
57e7986e | 3095 | /* |
cdd6c482 | 3096 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3097 | * This expects task == current. |
3098 | */ | |
c1274499 | 3099 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3100 | { |
c1274499 | 3101 | struct perf_event_context *ctx, *clone_ctx = NULL; |
cdd6c482 | 3102 | struct perf_event *event; |
57e7986e PM |
3103 | unsigned long flags; |
3104 | int enabled = 0; | |
889ff015 | 3105 | int ret; |
57e7986e PM |
3106 | |
3107 | local_irq_save(flags); | |
c1274499 | 3108 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3109 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3110 | goto out; |
3111 | ||
e566b76e SE |
3112 | /* |
3113 | * We must ctxsw out cgroup events to avoid conflict | |
3114 | * when invoking perf_task_event_sched_in() later on | |
3115 | * in this function. Otherwise we end up trying to | |
3116 | * ctxswin cgroup events which are already scheduled | |
3117 | * in. | |
3118 | */ | |
a8d757ef | 3119 | perf_cgroup_sched_out(current, NULL); |
57e7986e | 3120 | |
e625cce1 | 3121 | raw_spin_lock(&ctx->lock); |
04dc2dbb | 3122 | task_ctx_sched_out(ctx); |
57e7986e | 3123 | |
b79387ef | 3124 | list_for_each_entry(event, &ctx->event_list, event_entry) { |
889ff015 FW |
3125 | ret = event_enable_on_exec(event, ctx); |
3126 | if (ret) | |
3127 | enabled = 1; | |
57e7986e PM |
3128 | } |
3129 | ||
3130 | /* | |
cdd6c482 | 3131 | * Unclone this context if we enabled any event. |
57e7986e | 3132 | */ |
71a851b4 | 3133 | if (enabled) |
211de6eb | 3134 | clone_ctx = unclone_ctx(ctx); |
57e7986e | 3135 | |
e625cce1 | 3136 | raw_spin_unlock(&ctx->lock); |
57e7986e | 3137 | |
e566b76e SE |
3138 | /* |
3139 | * Also calls ctxswin for cgroup events, if any: | |
3140 | */ | |
e5d1367f | 3141 | perf_event_context_sched_in(ctx, ctx->task); |
9ed6060d | 3142 | out: |
57e7986e | 3143 | local_irq_restore(flags); |
211de6eb PZ |
3144 | |
3145 | if (clone_ctx) | |
3146 | put_ctx(clone_ctx); | |
57e7986e PM |
3147 | } |
3148 | ||
e041e328 PZ |
3149 | void perf_event_exec(void) |
3150 | { | |
e041e328 PZ |
3151 | int ctxn; |
3152 | ||
3153 | rcu_read_lock(); | |
c1274499 PZ |
3154 | for_each_task_context_nr(ctxn) |
3155 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3156 | rcu_read_unlock(); |
3157 | } | |
3158 | ||
0492d4c5 PZ |
3159 | struct perf_read_data { |
3160 | struct perf_event *event; | |
3161 | bool group; | |
7d88962e | 3162 | int ret; |
0492d4c5 PZ |
3163 | }; |
3164 | ||
0793a61d | 3165 | /* |
cdd6c482 | 3166 | * Cross CPU call to read the hardware event |
0793a61d | 3167 | */ |
cdd6c482 | 3168 | static void __perf_event_read(void *info) |
0793a61d | 3169 | { |
0492d4c5 PZ |
3170 | struct perf_read_data *data = info; |
3171 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3172 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3173 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3174 | struct pmu *pmu = event->pmu; |
621a01ea | 3175 | |
e1ac3614 PM |
3176 | /* |
3177 | * If this is a task context, we need to check whether it is | |
3178 | * the current task context of this cpu. If not it has been | |
3179 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3180 | * event->count would have been updated to a recent sample |
3181 | * when the event was scheduled out. | |
e1ac3614 PM |
3182 | */ |
3183 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3184 | return; | |
3185 | ||
e625cce1 | 3186 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3187 | if (ctx->is_active) { |
542e72fc | 3188 | update_context_time(ctx); |
e5d1367f SE |
3189 | update_cgrp_time_from_event(event); |
3190 | } | |
0492d4c5 | 3191 | |
cdd6c482 | 3192 | update_event_times(event); |
4a00c16e SB |
3193 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3194 | goto unlock; | |
0492d4c5 | 3195 | |
4a00c16e SB |
3196 | if (!data->group) { |
3197 | pmu->read(event); | |
3198 | data->ret = 0; | |
0492d4c5 | 3199 | goto unlock; |
4a00c16e SB |
3200 | } |
3201 | ||
3202 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3203 | ||
3204 | pmu->read(event); | |
0492d4c5 PZ |
3205 | |
3206 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3207 | update_event_times(sub); | |
4a00c16e SB |
3208 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3209 | /* | |
3210 | * Use sibling's PMU rather than @event's since | |
3211 | * sibling could be on different (eg: software) PMU. | |
3212 | */ | |
0492d4c5 | 3213 | sub->pmu->read(sub); |
4a00c16e | 3214 | } |
0492d4c5 | 3215 | } |
4a00c16e SB |
3216 | |
3217 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3218 | |
3219 | unlock: | |
e625cce1 | 3220 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3221 | } |
3222 | ||
b5e58793 PZ |
3223 | static inline u64 perf_event_count(struct perf_event *event) |
3224 | { | |
eacd3ecc MF |
3225 | if (event->pmu->count) |
3226 | return event->pmu->count(event); | |
3227 | ||
3228 | return __perf_event_count(event); | |
b5e58793 PZ |
3229 | } |
3230 | ||
ffe8690c KX |
3231 | /* |
3232 | * NMI-safe method to read a local event, that is an event that | |
3233 | * is: | |
3234 | * - either for the current task, or for this CPU | |
3235 | * - does not have inherit set, for inherited task events | |
3236 | * will not be local and we cannot read them atomically | |
3237 | * - must not have a pmu::count method | |
3238 | */ | |
3239 | u64 perf_event_read_local(struct perf_event *event) | |
3240 | { | |
3241 | unsigned long flags; | |
3242 | u64 val; | |
3243 | ||
3244 | /* | |
3245 | * Disabling interrupts avoids all counter scheduling (context | |
3246 | * switches, timer based rotation and IPIs). | |
3247 | */ | |
3248 | local_irq_save(flags); | |
3249 | ||
3250 | /* If this is a per-task event, it must be for current */ | |
3251 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3252 | event->hw.target != current); | |
3253 | ||
3254 | /* If this is a per-CPU event, it must be for this CPU */ | |
3255 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3256 | event->cpu != smp_processor_id()); | |
3257 | ||
3258 | /* | |
3259 | * It must not be an event with inherit set, we cannot read | |
3260 | * all child counters from atomic context. | |
3261 | */ | |
3262 | WARN_ON_ONCE(event->attr.inherit); | |
3263 | ||
3264 | /* | |
3265 | * It must not have a pmu::count method, those are not | |
3266 | * NMI safe. | |
3267 | */ | |
3268 | WARN_ON_ONCE(event->pmu->count); | |
3269 | ||
3270 | /* | |
3271 | * If the event is currently on this CPU, its either a per-task event, | |
3272 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3273 | * oncpu == -1). | |
3274 | */ | |
3275 | if (event->oncpu == smp_processor_id()) | |
3276 | event->pmu->read(event); | |
3277 | ||
3278 | val = local64_read(&event->count); | |
3279 | local_irq_restore(flags); | |
3280 | ||
3281 | return val; | |
3282 | } | |
3283 | ||
7d88962e | 3284 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3285 | { |
7d88962e SB |
3286 | int ret = 0; |
3287 | ||
0793a61d | 3288 | /* |
cdd6c482 IM |
3289 | * If event is enabled and currently active on a CPU, update the |
3290 | * value in the event structure: | |
0793a61d | 3291 | */ |
cdd6c482 | 3292 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3293 | struct perf_read_data data = { |
3294 | .event = event, | |
3295 | .group = group, | |
7d88962e | 3296 | .ret = 0, |
0492d4c5 | 3297 | }; |
cdd6c482 | 3298 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3299 | __perf_event_read, &data, 1); |
7d88962e | 3300 | ret = data.ret; |
cdd6c482 | 3301 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3302 | struct perf_event_context *ctx = event->ctx; |
3303 | unsigned long flags; | |
3304 | ||
e625cce1 | 3305 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3306 | /* |
3307 | * may read while context is not active | |
3308 | * (e.g., thread is blocked), in that case | |
3309 | * we cannot update context time | |
3310 | */ | |
e5d1367f | 3311 | if (ctx->is_active) { |
c530ccd9 | 3312 | update_context_time(ctx); |
e5d1367f SE |
3313 | update_cgrp_time_from_event(event); |
3314 | } | |
0492d4c5 PZ |
3315 | if (group) |
3316 | update_group_times(event); | |
3317 | else | |
3318 | update_event_times(event); | |
e625cce1 | 3319 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3320 | } |
7d88962e SB |
3321 | |
3322 | return ret; | |
0793a61d TG |
3323 | } |
3324 | ||
a63eaf34 | 3325 | /* |
cdd6c482 | 3326 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3327 | */ |
eb184479 | 3328 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3329 | { |
e625cce1 | 3330 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3331 | mutex_init(&ctx->mutex); |
2fde4f94 | 3332 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3333 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3334 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3335 | INIT_LIST_HEAD(&ctx->event_list); |
3336 | atomic_set(&ctx->refcount, 1); | |
fadfe7be | 3337 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); |
eb184479 PZ |
3338 | } |
3339 | ||
3340 | static struct perf_event_context * | |
3341 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3342 | { | |
3343 | struct perf_event_context *ctx; | |
3344 | ||
3345 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3346 | if (!ctx) | |
3347 | return NULL; | |
3348 | ||
3349 | __perf_event_init_context(ctx); | |
3350 | if (task) { | |
3351 | ctx->task = task; | |
3352 | get_task_struct(task); | |
0793a61d | 3353 | } |
eb184479 PZ |
3354 | ctx->pmu = pmu; |
3355 | ||
3356 | return ctx; | |
a63eaf34 PM |
3357 | } |
3358 | ||
2ebd4ffb MH |
3359 | static struct task_struct * |
3360 | find_lively_task_by_vpid(pid_t vpid) | |
3361 | { | |
3362 | struct task_struct *task; | |
3363 | int err; | |
0793a61d TG |
3364 | |
3365 | rcu_read_lock(); | |
2ebd4ffb | 3366 | if (!vpid) |
0793a61d TG |
3367 | task = current; |
3368 | else | |
2ebd4ffb | 3369 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3370 | if (task) |
3371 | get_task_struct(task); | |
3372 | rcu_read_unlock(); | |
3373 | ||
3374 | if (!task) | |
3375 | return ERR_PTR(-ESRCH); | |
3376 | ||
0793a61d | 3377 | /* Reuse ptrace permission checks for now. */ |
c93f7669 | 3378 | err = -EACCES; |
caaee623 | 3379 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) |
c93f7669 PM |
3380 | goto errout; |
3381 | ||
2ebd4ffb MH |
3382 | return task; |
3383 | errout: | |
3384 | put_task_struct(task); | |
3385 | return ERR_PTR(err); | |
3386 | ||
3387 | } | |
3388 | ||
fe4b04fa PZ |
3389 | /* |
3390 | * Returns a matching context with refcount and pincount. | |
3391 | */ | |
108b02cf | 3392 | static struct perf_event_context * |
4af57ef2 YZ |
3393 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3394 | struct perf_event *event) | |
0793a61d | 3395 | { |
211de6eb | 3396 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3397 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3398 | void *task_ctx_data = NULL; |
25346b93 | 3399 | unsigned long flags; |
8dc85d54 | 3400 | int ctxn, err; |
4af57ef2 | 3401 | int cpu = event->cpu; |
0793a61d | 3402 | |
22a4ec72 | 3403 | if (!task) { |
cdd6c482 | 3404 | /* Must be root to operate on a CPU event: */ |
0764771d | 3405 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3406 | return ERR_PTR(-EACCES); |
3407 | ||
0793a61d | 3408 | /* |
cdd6c482 | 3409 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3410 | * offline CPU and activate it when the CPU comes up, but |
3411 | * that's for later. | |
3412 | */ | |
f6325e30 | 3413 | if (!cpu_online(cpu)) |
0793a61d TG |
3414 | return ERR_PTR(-ENODEV); |
3415 | ||
108b02cf | 3416 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3417 | ctx = &cpuctx->ctx; |
c93f7669 | 3418 | get_ctx(ctx); |
fe4b04fa | 3419 | ++ctx->pin_count; |
0793a61d | 3420 | |
0793a61d TG |
3421 | return ctx; |
3422 | } | |
3423 | ||
8dc85d54 PZ |
3424 | err = -EINVAL; |
3425 | ctxn = pmu->task_ctx_nr; | |
3426 | if (ctxn < 0) | |
3427 | goto errout; | |
3428 | ||
4af57ef2 YZ |
3429 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3430 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3431 | if (!task_ctx_data) { | |
3432 | err = -ENOMEM; | |
3433 | goto errout; | |
3434 | } | |
3435 | } | |
3436 | ||
9ed6060d | 3437 | retry: |
8dc85d54 | 3438 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3439 | if (ctx) { |
211de6eb | 3440 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3441 | ++ctx->pin_count; |
4af57ef2 YZ |
3442 | |
3443 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3444 | ctx->task_ctx_data = task_ctx_data; | |
3445 | task_ctx_data = NULL; | |
3446 | } | |
e625cce1 | 3447 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3448 | |
3449 | if (clone_ctx) | |
3450 | put_ctx(clone_ctx); | |
9137fb28 | 3451 | } else { |
eb184479 | 3452 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3453 | err = -ENOMEM; |
3454 | if (!ctx) | |
3455 | goto errout; | |
eb184479 | 3456 | |
4af57ef2 YZ |
3457 | if (task_ctx_data) { |
3458 | ctx->task_ctx_data = task_ctx_data; | |
3459 | task_ctx_data = NULL; | |
3460 | } | |
3461 | ||
dbe08d82 ON |
3462 | err = 0; |
3463 | mutex_lock(&task->perf_event_mutex); | |
3464 | /* | |
3465 | * If it has already passed perf_event_exit_task(). | |
3466 | * we must see PF_EXITING, it takes this mutex too. | |
3467 | */ | |
3468 | if (task->flags & PF_EXITING) | |
3469 | err = -ESRCH; | |
3470 | else if (task->perf_event_ctxp[ctxn]) | |
3471 | err = -EAGAIN; | |
fe4b04fa | 3472 | else { |
9137fb28 | 3473 | get_ctx(ctx); |
fe4b04fa | 3474 | ++ctx->pin_count; |
dbe08d82 | 3475 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3476 | } |
dbe08d82 ON |
3477 | mutex_unlock(&task->perf_event_mutex); |
3478 | ||
3479 | if (unlikely(err)) { | |
9137fb28 | 3480 | put_ctx(ctx); |
dbe08d82 ON |
3481 | |
3482 | if (err == -EAGAIN) | |
3483 | goto retry; | |
3484 | goto errout; | |
a63eaf34 PM |
3485 | } |
3486 | } | |
3487 | ||
4af57ef2 | 3488 | kfree(task_ctx_data); |
0793a61d | 3489 | return ctx; |
c93f7669 | 3490 | |
9ed6060d | 3491 | errout: |
4af57ef2 | 3492 | kfree(task_ctx_data); |
c93f7669 | 3493 | return ERR_PTR(err); |
0793a61d TG |
3494 | } |
3495 | ||
6fb2915d | 3496 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3497 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3498 | |
cdd6c482 | 3499 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3500 | { |
cdd6c482 | 3501 | struct perf_event *event; |
592903cd | 3502 | |
cdd6c482 IM |
3503 | event = container_of(head, struct perf_event, rcu_head); |
3504 | if (event->ns) | |
3505 | put_pid_ns(event->ns); | |
6fb2915d | 3506 | perf_event_free_filter(event); |
cdd6c482 | 3507 | kfree(event); |
592903cd PZ |
3508 | } |
3509 | ||
b69cf536 PZ |
3510 | static void ring_buffer_attach(struct perf_event *event, |
3511 | struct ring_buffer *rb); | |
925d519a | 3512 | |
4beb31f3 | 3513 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3514 | { |
4beb31f3 FW |
3515 | if (event->parent) |
3516 | return; | |
3517 | ||
4beb31f3 FW |
3518 | if (is_cgroup_event(event)) |
3519 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3520 | } | |
925d519a | 3521 | |
4beb31f3 FW |
3522 | static void unaccount_event(struct perf_event *event) |
3523 | { | |
3524 | if (event->parent) | |
3525 | return; | |
3526 | ||
3527 | if (event->attach_state & PERF_ATTACH_TASK) | |
3528 | static_key_slow_dec_deferred(&perf_sched_events); | |
3529 | if (event->attr.mmap || event->attr.mmap_data) | |
3530 | atomic_dec(&nr_mmap_events); | |
3531 | if (event->attr.comm) | |
3532 | atomic_dec(&nr_comm_events); | |
3533 | if (event->attr.task) | |
3534 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3535 | if (event->attr.freq) |
3536 | atomic_dec(&nr_freq_events); | |
45ac1403 AH |
3537 | if (event->attr.context_switch) { |
3538 | static_key_slow_dec_deferred(&perf_sched_events); | |
3539 | atomic_dec(&nr_switch_events); | |
3540 | } | |
4beb31f3 FW |
3541 | if (is_cgroup_event(event)) |
3542 | static_key_slow_dec_deferred(&perf_sched_events); | |
3543 | if (has_branch_stack(event)) | |
3544 | static_key_slow_dec_deferred(&perf_sched_events); | |
3545 | ||
3546 | unaccount_event_cpu(event, event->cpu); | |
3547 | } | |
925d519a | 3548 | |
bed5b25a AS |
3549 | /* |
3550 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3551 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3552 | * at a time, so we disallow creating events that might conflict, namely: | |
3553 | * | |
3554 | * 1) cpu-wide events in the presence of per-task events, | |
3555 | * 2) per-task events in the presence of cpu-wide events, | |
3556 | * 3) two matching events on the same context. | |
3557 | * | |
3558 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
3559 | * __free_event()), the latter -- before the first perf_install_in_context(). | |
3560 | */ | |
3561 | static int exclusive_event_init(struct perf_event *event) | |
3562 | { | |
3563 | struct pmu *pmu = event->pmu; | |
3564 | ||
3565 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3566 | return 0; | |
3567 | ||
3568 | /* | |
3569 | * Prevent co-existence of per-task and cpu-wide events on the | |
3570 | * same exclusive pmu. | |
3571 | * | |
3572 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3573 | * events on this "exclusive" pmu, positive means there are | |
3574 | * per-task events. | |
3575 | * | |
3576 | * Since this is called in perf_event_alloc() path, event::ctx | |
3577 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3578 | * to mean "per-task event", because unlike other attach states it | |
3579 | * never gets cleared. | |
3580 | */ | |
3581 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3582 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3583 | return -EBUSY; | |
3584 | } else { | |
3585 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3586 | return -EBUSY; | |
3587 | } | |
3588 | ||
3589 | return 0; | |
3590 | } | |
3591 | ||
3592 | static void exclusive_event_destroy(struct perf_event *event) | |
3593 | { | |
3594 | struct pmu *pmu = event->pmu; | |
3595 | ||
3596 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3597 | return; | |
3598 | ||
3599 | /* see comment in exclusive_event_init() */ | |
3600 | if (event->attach_state & PERF_ATTACH_TASK) | |
3601 | atomic_dec(&pmu->exclusive_cnt); | |
3602 | else | |
3603 | atomic_inc(&pmu->exclusive_cnt); | |
3604 | } | |
3605 | ||
3606 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3607 | { | |
3608 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3609 | (e1->cpu == e2->cpu || | |
3610 | e1->cpu == -1 || | |
3611 | e2->cpu == -1)) | |
3612 | return true; | |
3613 | return false; | |
3614 | } | |
3615 | ||
3616 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3617 | static bool exclusive_event_installable(struct perf_event *event, | |
3618 | struct perf_event_context *ctx) | |
3619 | { | |
3620 | struct perf_event *iter_event; | |
3621 | struct pmu *pmu = event->pmu; | |
3622 | ||
3623 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3624 | return true; | |
3625 | ||
3626 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3627 | if (exclusive_event_match(iter_event, event)) | |
3628 | return false; | |
3629 | } | |
3630 | ||
3631 | return true; | |
3632 | } | |
3633 | ||
766d6c07 FW |
3634 | static void __free_event(struct perf_event *event) |
3635 | { | |
cdd6c482 | 3636 | if (!event->parent) { |
927c7a9e FW |
3637 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3638 | put_callchain_buffers(); | |
f344011c | 3639 | } |
9ee318a7 | 3640 | |
dead9f29 AS |
3641 | perf_event_free_bpf_prog(event); |
3642 | ||
766d6c07 FW |
3643 | if (event->destroy) |
3644 | event->destroy(event); | |
3645 | ||
3646 | if (event->ctx) | |
3647 | put_ctx(event->ctx); | |
3648 | ||
bed5b25a AS |
3649 | if (event->pmu) { |
3650 | exclusive_event_destroy(event); | |
c464c76e | 3651 | module_put(event->pmu->module); |
bed5b25a | 3652 | } |
c464c76e | 3653 | |
766d6c07 FW |
3654 | call_rcu(&event->rcu_head, free_event_rcu); |
3655 | } | |
683ede43 PZ |
3656 | |
3657 | static void _free_event(struct perf_event *event) | |
f1600952 | 3658 | { |
e360adbe | 3659 | irq_work_sync(&event->pending); |
925d519a | 3660 | |
4beb31f3 | 3661 | unaccount_event(event); |
9ee318a7 | 3662 | |
76369139 | 3663 | if (event->rb) { |
9bb5d40c PZ |
3664 | /* |
3665 | * Can happen when we close an event with re-directed output. | |
3666 | * | |
3667 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3668 | * over us; possibly making our ring_buffer_put() the last. | |
3669 | */ | |
3670 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3671 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3672 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3673 | } |
3674 | ||
e5d1367f SE |
3675 | if (is_cgroup_event(event)) |
3676 | perf_detach_cgroup(event); | |
3677 | ||
766d6c07 | 3678 | __free_event(event); |
f1600952 PZ |
3679 | } |
3680 | ||
683ede43 PZ |
3681 | /* |
3682 | * Used to free events which have a known refcount of 1, such as in error paths | |
3683 | * where the event isn't exposed yet and inherited events. | |
3684 | */ | |
3685 | static void free_event(struct perf_event *event) | |
0793a61d | 3686 | { |
683ede43 PZ |
3687 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3688 | "unexpected event refcount: %ld; ptr=%p\n", | |
3689 | atomic_long_read(&event->refcount), event)) { | |
3690 | /* leak to avoid use-after-free */ | |
3691 | return; | |
3692 | } | |
0793a61d | 3693 | |
683ede43 | 3694 | _free_event(event); |
0793a61d TG |
3695 | } |
3696 | ||
a66a3052 | 3697 | /* |
f8697762 | 3698 | * Remove user event from the owner task. |
a66a3052 | 3699 | */ |
f8697762 | 3700 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3701 | { |
8882135b | 3702 | struct task_struct *owner; |
fb0459d7 | 3703 | |
8882135b PZ |
3704 | rcu_read_lock(); |
3705 | owner = ACCESS_ONCE(event->owner); | |
3706 | /* | |
3707 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3708 | * !owner it means the list deletion is complete and we can indeed | |
3709 | * free this event, otherwise we need to serialize on | |
3710 | * owner->perf_event_mutex. | |
3711 | */ | |
3712 | smp_read_barrier_depends(); | |
3713 | if (owner) { | |
3714 | /* | |
3715 | * Since delayed_put_task_struct() also drops the last | |
3716 | * task reference we can safely take a new reference | |
3717 | * while holding the rcu_read_lock(). | |
3718 | */ | |
3719 | get_task_struct(owner); | |
3720 | } | |
3721 | rcu_read_unlock(); | |
3722 | ||
3723 | if (owner) { | |
f63a8daa PZ |
3724 | /* |
3725 | * If we're here through perf_event_exit_task() we're already | |
3726 | * holding ctx->mutex which would be an inversion wrt. the | |
3727 | * normal lock order. | |
3728 | * | |
3729 | * However we can safely take this lock because its the child | |
3730 | * ctx->mutex. | |
3731 | */ | |
3732 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3733 | ||
8882135b PZ |
3734 | /* |
3735 | * We have to re-check the event->owner field, if it is cleared | |
3736 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3737 | * ensured they're done, and we can proceed with freeing the | |
3738 | * event. | |
3739 | */ | |
3740 | if (event->owner) | |
3741 | list_del_init(&event->owner_entry); | |
3742 | mutex_unlock(&owner->perf_event_mutex); | |
3743 | put_task_struct(owner); | |
3744 | } | |
f8697762 JO |
3745 | } |
3746 | ||
f8697762 JO |
3747 | static void put_event(struct perf_event *event) |
3748 | { | |
a83fe28e | 3749 | struct perf_event_context *ctx; |
f8697762 JO |
3750 | |
3751 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3752 | return; | |
3753 | ||
3754 | if (!is_kernel_event(event)) | |
3755 | perf_remove_from_owner(event); | |
8882135b | 3756 | |
683ede43 PZ |
3757 | /* |
3758 | * There are two ways this annotation is useful: | |
3759 | * | |
3760 | * 1) there is a lock recursion from perf_event_exit_task | |
3761 | * see the comment there. | |
3762 | * | |
3763 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3764 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3765 | * holding ctx->mutex, however this is called after |
3766 | * the last filedesc died, so there is no possibility | |
3767 | * to trigger the AB-BA case. | |
3768 | */ | |
a83fe28e PZ |
3769 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3770 | WARN_ON_ONCE(ctx->parent_ctx); | |
683ede43 | 3771 | perf_remove_from_context(event, true); |
d415a7f1 | 3772 | perf_event_ctx_unlock(event, ctx); |
683ede43 PZ |
3773 | |
3774 | _free_event(event); | |
a6fa941d AV |
3775 | } |
3776 | ||
683ede43 PZ |
3777 | int perf_event_release_kernel(struct perf_event *event) |
3778 | { | |
3779 | put_event(event); | |
3780 | return 0; | |
3781 | } | |
3782 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3783 | ||
8b10c5e2 PZ |
3784 | /* |
3785 | * Called when the last reference to the file is gone. | |
3786 | */ | |
a6fa941d AV |
3787 | static int perf_release(struct inode *inode, struct file *file) |
3788 | { | |
3789 | put_event(file->private_data); | |
3790 | return 0; | |
fb0459d7 | 3791 | } |
fb0459d7 | 3792 | |
fadfe7be JO |
3793 | /* |
3794 | * Remove all orphanes events from the context. | |
3795 | */ | |
3796 | static void orphans_remove_work(struct work_struct *work) | |
3797 | { | |
3798 | struct perf_event_context *ctx; | |
3799 | struct perf_event *event, *tmp; | |
3800 | ||
3801 | ctx = container_of(work, struct perf_event_context, | |
3802 | orphans_remove.work); | |
3803 | ||
3804 | mutex_lock(&ctx->mutex); | |
3805 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3806 | struct perf_event *parent_event = event->parent; | |
3807 | ||
3808 | if (!is_orphaned_child(event)) | |
3809 | continue; | |
3810 | ||
3811 | perf_remove_from_context(event, true); | |
3812 | ||
3813 | mutex_lock(&parent_event->child_mutex); | |
3814 | list_del_init(&event->child_list); | |
3815 | mutex_unlock(&parent_event->child_mutex); | |
3816 | ||
3817 | free_event(event); | |
3818 | put_event(parent_event); | |
3819 | } | |
3820 | ||
3821 | raw_spin_lock_irq(&ctx->lock); | |
3822 | ctx->orphans_remove_sched = false; | |
3823 | raw_spin_unlock_irq(&ctx->lock); | |
3824 | mutex_unlock(&ctx->mutex); | |
3825 | ||
3826 | put_ctx(ctx); | |
3827 | } | |
3828 | ||
59ed446f | 3829 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3830 | { |
cdd6c482 | 3831 | struct perf_event *child; |
e53c0994 PZ |
3832 | u64 total = 0; |
3833 | ||
59ed446f PZ |
3834 | *enabled = 0; |
3835 | *running = 0; | |
3836 | ||
6f10581a | 3837 | mutex_lock(&event->child_mutex); |
01add3ea | 3838 | |
7d88962e | 3839 | (void)perf_event_read(event, false); |
01add3ea SB |
3840 | total += perf_event_count(event); |
3841 | ||
59ed446f PZ |
3842 | *enabled += event->total_time_enabled + |
3843 | atomic64_read(&event->child_total_time_enabled); | |
3844 | *running += event->total_time_running + | |
3845 | atomic64_read(&event->child_total_time_running); | |
3846 | ||
3847 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3848 | (void)perf_event_read(child, false); |
01add3ea | 3849 | total += perf_event_count(child); |
59ed446f PZ |
3850 | *enabled += child->total_time_enabled; |
3851 | *running += child->total_time_running; | |
3852 | } | |
6f10581a | 3853 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3854 | |
3855 | return total; | |
3856 | } | |
fb0459d7 | 3857 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3858 | |
7d88962e | 3859 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3860 | u64 read_format, u64 *values) |
3dab77fb | 3861 | { |
fa8c2693 PZ |
3862 | struct perf_event *sub; |
3863 | int n = 1; /* skip @nr */ | |
7d88962e | 3864 | int ret; |
f63a8daa | 3865 | |
7d88962e SB |
3866 | ret = perf_event_read(leader, true); |
3867 | if (ret) | |
3868 | return ret; | |
abf4868b | 3869 | |
fa8c2693 PZ |
3870 | /* |
3871 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3872 | * will be identical to those of the leader, so we only publish one | |
3873 | * set. | |
3874 | */ | |
3875 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3876 | values[n++] += leader->total_time_enabled + | |
3877 | atomic64_read(&leader->child_total_time_enabled); | |
3878 | } | |
3dab77fb | 3879 | |
fa8c2693 PZ |
3880 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3881 | values[n++] += leader->total_time_running + | |
3882 | atomic64_read(&leader->child_total_time_running); | |
3883 | } | |
3884 | ||
3885 | /* | |
3886 | * Write {count,id} tuples for every sibling. | |
3887 | */ | |
3888 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3889 | if (read_format & PERF_FORMAT_ID) |
3890 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3891 | |
fa8c2693 PZ |
3892 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3893 | values[n++] += perf_event_count(sub); | |
3894 | if (read_format & PERF_FORMAT_ID) | |
3895 | values[n++] = primary_event_id(sub); | |
3896 | } | |
7d88962e SB |
3897 | |
3898 | return 0; | |
fa8c2693 | 3899 | } |
3dab77fb | 3900 | |
fa8c2693 PZ |
3901 | static int perf_read_group(struct perf_event *event, |
3902 | u64 read_format, char __user *buf) | |
3903 | { | |
3904 | struct perf_event *leader = event->group_leader, *child; | |
3905 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3906 | int ret; |
fa8c2693 | 3907 | u64 *values; |
3dab77fb | 3908 | |
fa8c2693 | 3909 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3910 | |
fa8c2693 PZ |
3911 | values = kzalloc(event->read_size, GFP_KERNEL); |
3912 | if (!values) | |
3913 | return -ENOMEM; | |
3dab77fb | 3914 | |
fa8c2693 PZ |
3915 | values[0] = 1 + leader->nr_siblings; |
3916 | ||
3917 | /* | |
3918 | * By locking the child_mutex of the leader we effectively | |
3919 | * lock the child list of all siblings.. XXX explain how. | |
3920 | */ | |
3921 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3922 | |
7d88962e SB |
3923 | ret = __perf_read_group_add(leader, read_format, values); |
3924 | if (ret) | |
3925 | goto unlock; | |
3926 | ||
3927 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3928 | ret = __perf_read_group_add(child, read_format, values); | |
3929 | if (ret) | |
3930 | goto unlock; | |
3931 | } | |
abf4868b | 3932 | |
fa8c2693 | 3933 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3934 | |
7d88962e | 3935 | ret = event->read_size; |
fa8c2693 PZ |
3936 | if (copy_to_user(buf, values, event->read_size)) |
3937 | ret = -EFAULT; | |
7d88962e | 3938 | goto out; |
fa8c2693 | 3939 | |
7d88962e SB |
3940 | unlock: |
3941 | mutex_unlock(&leader->child_mutex); | |
3942 | out: | |
fa8c2693 | 3943 | kfree(values); |
abf4868b | 3944 | return ret; |
3dab77fb PZ |
3945 | } |
3946 | ||
b15f495b | 3947 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3948 | u64 read_format, char __user *buf) |
3949 | { | |
59ed446f | 3950 | u64 enabled, running; |
3dab77fb PZ |
3951 | u64 values[4]; |
3952 | int n = 0; | |
3953 | ||
59ed446f PZ |
3954 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3955 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3956 | values[n++] = enabled; | |
3957 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3958 | values[n++] = running; | |
3dab77fb | 3959 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3960 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3961 | |
3962 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3963 | return -EFAULT; | |
3964 | ||
3965 | return n * sizeof(u64); | |
3966 | } | |
3967 | ||
dc633982 JO |
3968 | static bool is_event_hup(struct perf_event *event) |
3969 | { | |
3970 | bool no_children; | |
3971 | ||
3972 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3973 | return false; | |
3974 | ||
3975 | mutex_lock(&event->child_mutex); | |
3976 | no_children = list_empty(&event->child_list); | |
3977 | mutex_unlock(&event->child_mutex); | |
3978 | return no_children; | |
3979 | } | |
3980 | ||
0793a61d | 3981 | /* |
cdd6c482 | 3982 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3983 | */ |
3984 | static ssize_t | |
b15f495b | 3985 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3986 | { |
cdd6c482 | 3987 | u64 read_format = event->attr.read_format; |
3dab77fb | 3988 | int ret; |
0793a61d | 3989 | |
3b6f9e5c | 3990 | /* |
cdd6c482 | 3991 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
3992 | * error state (i.e. because it was pinned but it couldn't be |
3993 | * scheduled on to the CPU at some point). | |
3994 | */ | |
cdd6c482 | 3995 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
3996 | return 0; |
3997 | ||
c320c7b7 | 3998 | if (count < event->read_size) |
3dab77fb PZ |
3999 | return -ENOSPC; |
4000 | ||
cdd6c482 | 4001 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4002 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4003 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4004 | else |
b15f495b | 4005 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4006 | |
3dab77fb | 4007 | return ret; |
0793a61d TG |
4008 | } |
4009 | ||
0793a61d TG |
4010 | static ssize_t |
4011 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4012 | { | |
cdd6c482 | 4013 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4014 | struct perf_event_context *ctx; |
4015 | int ret; | |
0793a61d | 4016 | |
f63a8daa | 4017 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4018 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4019 | perf_event_ctx_unlock(event, ctx); |
4020 | ||
4021 | return ret; | |
0793a61d TG |
4022 | } |
4023 | ||
4024 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4025 | { | |
cdd6c482 | 4026 | struct perf_event *event = file->private_data; |
76369139 | 4027 | struct ring_buffer *rb; |
61b67684 | 4028 | unsigned int events = POLLHUP; |
c7138f37 | 4029 | |
e708d7ad | 4030 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4031 | |
dc633982 | 4032 | if (is_event_hup(event)) |
179033b3 | 4033 | return events; |
c7138f37 | 4034 | |
10c6db11 | 4035 | /* |
9bb5d40c PZ |
4036 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4037 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4038 | */ |
4039 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4040 | rb = event->rb; |
4041 | if (rb) | |
76369139 | 4042 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4043 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4044 | return events; |
4045 | } | |
4046 | ||
f63a8daa | 4047 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4048 | { |
7d88962e | 4049 | (void)perf_event_read(event, false); |
e7850595 | 4050 | local64_set(&event->count, 0); |
cdd6c482 | 4051 | perf_event_update_userpage(event); |
3df5edad PZ |
4052 | } |
4053 | ||
c93f7669 | 4054 | /* |
cdd6c482 IM |
4055 | * Holding the top-level event's child_mutex means that any |
4056 | * descendant process that has inherited this event will block | |
4057 | * in sync_child_event if it goes to exit, thus satisfying the | |
4058 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 4059 | */ |
cdd6c482 IM |
4060 | static void perf_event_for_each_child(struct perf_event *event, |
4061 | void (*func)(struct perf_event *)) | |
3df5edad | 4062 | { |
cdd6c482 | 4063 | struct perf_event *child; |
3df5edad | 4064 | |
cdd6c482 | 4065 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4066 | |
cdd6c482 IM |
4067 | mutex_lock(&event->child_mutex); |
4068 | func(event); | |
4069 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4070 | func(child); |
cdd6c482 | 4071 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4072 | } |
4073 | ||
cdd6c482 IM |
4074 | static void perf_event_for_each(struct perf_event *event, |
4075 | void (*func)(struct perf_event *)) | |
3df5edad | 4076 | { |
cdd6c482 IM |
4077 | struct perf_event_context *ctx = event->ctx; |
4078 | struct perf_event *sibling; | |
3df5edad | 4079 | |
f63a8daa PZ |
4080 | lockdep_assert_held(&ctx->mutex); |
4081 | ||
cdd6c482 | 4082 | event = event->group_leader; |
75f937f2 | 4083 | |
cdd6c482 | 4084 | perf_event_for_each_child(event, func); |
cdd6c482 | 4085 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4086 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4087 | } |
4088 | ||
c7999c6f PZ |
4089 | struct period_event { |
4090 | struct perf_event *event; | |
08247e31 | 4091 | u64 value; |
c7999c6f | 4092 | }; |
08247e31 | 4093 | |
0017960f PZ |
4094 | static void ___perf_event_period(void *info) |
4095 | { | |
4096 | struct period_event *pe = info; | |
4097 | struct perf_event *event = pe->event; | |
4098 | u64 value = pe->value; | |
4099 | ||
4100 | if (event->attr.freq) { | |
4101 | event->attr.sample_freq = value; | |
4102 | } else { | |
4103 | event->attr.sample_period = value; | |
4104 | event->hw.sample_period = value; | |
4105 | } | |
4106 | ||
4107 | local64_set(&event->hw.period_left, 0); | |
4108 | } | |
4109 | ||
c7999c6f PZ |
4110 | static int __perf_event_period(void *info) |
4111 | { | |
4112 | struct period_event *pe = info; | |
4113 | struct perf_event *event = pe->event; | |
4114 | struct perf_event_context *ctx = event->ctx; | |
4115 | u64 value = pe->value; | |
4116 | bool active; | |
08247e31 | 4117 | |
c7999c6f | 4118 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 4119 | if (event->attr.freq) { |
cdd6c482 | 4120 | event->attr.sample_freq = value; |
08247e31 | 4121 | } else { |
cdd6c482 IM |
4122 | event->attr.sample_period = value; |
4123 | event->hw.sample_period = value; | |
08247e31 | 4124 | } |
bad7192b PZ |
4125 | |
4126 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4127 | if (active) { | |
4128 | perf_pmu_disable(ctx->pmu); | |
4129 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4130 | } | |
4131 | ||
4132 | local64_set(&event->hw.period_left, 0); | |
4133 | ||
4134 | if (active) { | |
4135 | event->pmu->start(event, PERF_EF_RELOAD); | |
4136 | perf_pmu_enable(ctx->pmu); | |
4137 | } | |
c7999c6f | 4138 | raw_spin_unlock(&ctx->lock); |
bad7192b | 4139 | |
c7999c6f PZ |
4140 | return 0; |
4141 | } | |
4142 | ||
4143 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4144 | { | |
4145 | struct period_event pe = { .event = event, }; | |
c7999c6f PZ |
4146 | u64 value; |
4147 | ||
4148 | if (!is_sampling_event(event)) | |
4149 | return -EINVAL; | |
4150 | ||
4151 | if (copy_from_user(&value, arg, sizeof(value))) | |
4152 | return -EFAULT; | |
4153 | ||
4154 | if (!value) | |
4155 | return -EINVAL; | |
4156 | ||
4157 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4158 | return -EINVAL; | |
4159 | ||
c7999c6f PZ |
4160 | pe.value = value; |
4161 | ||
0017960f PZ |
4162 | event_function_call(event, __perf_event_period, |
4163 | ___perf_event_period, &pe); | |
08247e31 | 4164 | |
c7999c6f | 4165 | return 0; |
08247e31 PZ |
4166 | } |
4167 | ||
ac9721f3 PZ |
4168 | static const struct file_operations perf_fops; |
4169 | ||
2903ff01 | 4170 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4171 | { |
2903ff01 AV |
4172 | struct fd f = fdget(fd); |
4173 | if (!f.file) | |
4174 | return -EBADF; | |
ac9721f3 | 4175 | |
2903ff01 AV |
4176 | if (f.file->f_op != &perf_fops) { |
4177 | fdput(f); | |
4178 | return -EBADF; | |
ac9721f3 | 4179 | } |
2903ff01 AV |
4180 | *p = f; |
4181 | return 0; | |
ac9721f3 PZ |
4182 | } |
4183 | ||
4184 | static int perf_event_set_output(struct perf_event *event, | |
4185 | struct perf_event *output_event); | |
6fb2915d | 4186 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4187 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4188 | |
f63a8daa | 4189 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4190 | { |
cdd6c482 | 4191 | void (*func)(struct perf_event *); |
3df5edad | 4192 | u32 flags = arg; |
d859e29f PM |
4193 | |
4194 | switch (cmd) { | |
cdd6c482 | 4195 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4196 | func = _perf_event_enable; |
d859e29f | 4197 | break; |
cdd6c482 | 4198 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4199 | func = _perf_event_disable; |
79f14641 | 4200 | break; |
cdd6c482 | 4201 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4202 | func = _perf_event_reset; |
6de6a7b9 | 4203 | break; |
3df5edad | 4204 | |
cdd6c482 | 4205 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4206 | return _perf_event_refresh(event, arg); |
08247e31 | 4207 | |
cdd6c482 IM |
4208 | case PERF_EVENT_IOC_PERIOD: |
4209 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4210 | |
cf4957f1 JO |
4211 | case PERF_EVENT_IOC_ID: |
4212 | { | |
4213 | u64 id = primary_event_id(event); | |
4214 | ||
4215 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4216 | return -EFAULT; | |
4217 | return 0; | |
4218 | } | |
4219 | ||
cdd6c482 | 4220 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4221 | { |
ac9721f3 | 4222 | int ret; |
ac9721f3 | 4223 | if (arg != -1) { |
2903ff01 AV |
4224 | struct perf_event *output_event; |
4225 | struct fd output; | |
4226 | ret = perf_fget_light(arg, &output); | |
4227 | if (ret) | |
4228 | return ret; | |
4229 | output_event = output.file->private_data; | |
4230 | ret = perf_event_set_output(event, output_event); | |
4231 | fdput(output); | |
4232 | } else { | |
4233 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4234 | } |
ac9721f3 PZ |
4235 | return ret; |
4236 | } | |
a4be7c27 | 4237 | |
6fb2915d LZ |
4238 | case PERF_EVENT_IOC_SET_FILTER: |
4239 | return perf_event_set_filter(event, (void __user *)arg); | |
4240 | ||
2541517c AS |
4241 | case PERF_EVENT_IOC_SET_BPF: |
4242 | return perf_event_set_bpf_prog(event, arg); | |
4243 | ||
d859e29f | 4244 | default: |
3df5edad | 4245 | return -ENOTTY; |
d859e29f | 4246 | } |
3df5edad PZ |
4247 | |
4248 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4249 | perf_event_for_each(event, func); |
3df5edad | 4250 | else |
cdd6c482 | 4251 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4252 | |
4253 | return 0; | |
d859e29f PM |
4254 | } |
4255 | ||
f63a8daa PZ |
4256 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4257 | { | |
4258 | struct perf_event *event = file->private_data; | |
4259 | struct perf_event_context *ctx; | |
4260 | long ret; | |
4261 | ||
4262 | ctx = perf_event_ctx_lock(event); | |
4263 | ret = _perf_ioctl(event, cmd, arg); | |
4264 | perf_event_ctx_unlock(event, ctx); | |
4265 | ||
4266 | return ret; | |
4267 | } | |
4268 | ||
b3f20785 PM |
4269 | #ifdef CONFIG_COMPAT |
4270 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4271 | unsigned long arg) | |
4272 | { | |
4273 | switch (_IOC_NR(cmd)) { | |
4274 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4275 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4276 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4277 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4278 | cmd &= ~IOCSIZE_MASK; | |
4279 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4280 | } | |
4281 | break; | |
4282 | } | |
4283 | return perf_ioctl(file, cmd, arg); | |
4284 | } | |
4285 | #else | |
4286 | # define perf_compat_ioctl NULL | |
4287 | #endif | |
4288 | ||
cdd6c482 | 4289 | int perf_event_task_enable(void) |
771d7cde | 4290 | { |
f63a8daa | 4291 | struct perf_event_context *ctx; |
cdd6c482 | 4292 | struct perf_event *event; |
771d7cde | 4293 | |
cdd6c482 | 4294 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4295 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4296 | ctx = perf_event_ctx_lock(event); | |
4297 | perf_event_for_each_child(event, _perf_event_enable); | |
4298 | perf_event_ctx_unlock(event, ctx); | |
4299 | } | |
cdd6c482 | 4300 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4301 | |
4302 | return 0; | |
4303 | } | |
4304 | ||
cdd6c482 | 4305 | int perf_event_task_disable(void) |
771d7cde | 4306 | { |
f63a8daa | 4307 | struct perf_event_context *ctx; |
cdd6c482 | 4308 | struct perf_event *event; |
771d7cde | 4309 | |
cdd6c482 | 4310 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4311 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4312 | ctx = perf_event_ctx_lock(event); | |
4313 | perf_event_for_each_child(event, _perf_event_disable); | |
4314 | perf_event_ctx_unlock(event, ctx); | |
4315 | } | |
cdd6c482 | 4316 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4317 | |
4318 | return 0; | |
4319 | } | |
4320 | ||
cdd6c482 | 4321 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4322 | { |
a4eaf7f1 PZ |
4323 | if (event->hw.state & PERF_HES_STOPPED) |
4324 | return 0; | |
4325 | ||
cdd6c482 | 4326 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4327 | return 0; |
4328 | ||
35edc2a5 | 4329 | return event->pmu->event_idx(event); |
194002b2 PZ |
4330 | } |
4331 | ||
c4794295 | 4332 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4333 | u64 *now, |
7f310a5d EM |
4334 | u64 *enabled, |
4335 | u64 *running) | |
c4794295 | 4336 | { |
e3f3541c | 4337 | u64 ctx_time; |
c4794295 | 4338 | |
e3f3541c PZ |
4339 | *now = perf_clock(); |
4340 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4341 | *enabled = ctx_time - event->tstamp_enabled; |
4342 | *running = ctx_time - event->tstamp_running; | |
4343 | } | |
4344 | ||
fa731587 PZ |
4345 | static void perf_event_init_userpage(struct perf_event *event) |
4346 | { | |
4347 | struct perf_event_mmap_page *userpg; | |
4348 | struct ring_buffer *rb; | |
4349 | ||
4350 | rcu_read_lock(); | |
4351 | rb = rcu_dereference(event->rb); | |
4352 | if (!rb) | |
4353 | goto unlock; | |
4354 | ||
4355 | userpg = rb->user_page; | |
4356 | ||
4357 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4358 | userpg->cap_bit0_is_deprecated = 1; | |
4359 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4360 | userpg->data_offset = PAGE_SIZE; |
4361 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4362 | |
4363 | unlock: | |
4364 | rcu_read_unlock(); | |
4365 | } | |
4366 | ||
c1317ec2 AL |
4367 | void __weak arch_perf_update_userpage( |
4368 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4369 | { |
4370 | } | |
4371 | ||
38ff667b PZ |
4372 | /* |
4373 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4374 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4375 | * code calls this from NMI context. | |
4376 | */ | |
cdd6c482 | 4377 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4378 | { |
cdd6c482 | 4379 | struct perf_event_mmap_page *userpg; |
76369139 | 4380 | struct ring_buffer *rb; |
e3f3541c | 4381 | u64 enabled, running, now; |
38ff667b PZ |
4382 | |
4383 | rcu_read_lock(); | |
5ec4c599 PZ |
4384 | rb = rcu_dereference(event->rb); |
4385 | if (!rb) | |
4386 | goto unlock; | |
4387 | ||
0d641208 EM |
4388 | /* |
4389 | * compute total_time_enabled, total_time_running | |
4390 | * based on snapshot values taken when the event | |
4391 | * was last scheduled in. | |
4392 | * | |
4393 | * we cannot simply called update_context_time() | |
4394 | * because of locking issue as we can be called in | |
4395 | * NMI context | |
4396 | */ | |
e3f3541c | 4397 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4398 | |
76369139 | 4399 | userpg = rb->user_page; |
7b732a75 PZ |
4400 | /* |
4401 | * Disable preemption so as to not let the corresponding user-space | |
4402 | * spin too long if we get preempted. | |
4403 | */ | |
4404 | preempt_disable(); | |
37d81828 | 4405 | ++userpg->lock; |
92f22a38 | 4406 | barrier(); |
cdd6c482 | 4407 | userpg->index = perf_event_index(event); |
b5e58793 | 4408 | userpg->offset = perf_event_count(event); |
365a4038 | 4409 | if (userpg->index) |
e7850595 | 4410 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4411 | |
0d641208 | 4412 | userpg->time_enabled = enabled + |
cdd6c482 | 4413 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4414 | |
0d641208 | 4415 | userpg->time_running = running + |
cdd6c482 | 4416 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4417 | |
c1317ec2 | 4418 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4419 | |
92f22a38 | 4420 | barrier(); |
37d81828 | 4421 | ++userpg->lock; |
7b732a75 | 4422 | preempt_enable(); |
38ff667b | 4423 | unlock: |
7b732a75 | 4424 | rcu_read_unlock(); |
37d81828 PM |
4425 | } |
4426 | ||
906010b2 PZ |
4427 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4428 | { | |
4429 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4430 | struct ring_buffer *rb; |
906010b2 PZ |
4431 | int ret = VM_FAULT_SIGBUS; |
4432 | ||
4433 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4434 | if (vmf->pgoff == 0) | |
4435 | ret = 0; | |
4436 | return ret; | |
4437 | } | |
4438 | ||
4439 | rcu_read_lock(); | |
76369139 FW |
4440 | rb = rcu_dereference(event->rb); |
4441 | if (!rb) | |
906010b2 PZ |
4442 | goto unlock; |
4443 | ||
4444 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4445 | goto unlock; | |
4446 | ||
76369139 | 4447 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4448 | if (!vmf->page) |
4449 | goto unlock; | |
4450 | ||
4451 | get_page(vmf->page); | |
4452 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4453 | vmf->page->index = vmf->pgoff; | |
4454 | ||
4455 | ret = 0; | |
4456 | unlock: | |
4457 | rcu_read_unlock(); | |
4458 | ||
4459 | return ret; | |
4460 | } | |
4461 | ||
10c6db11 PZ |
4462 | static void ring_buffer_attach(struct perf_event *event, |
4463 | struct ring_buffer *rb) | |
4464 | { | |
b69cf536 | 4465 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4466 | unsigned long flags; |
4467 | ||
b69cf536 PZ |
4468 | if (event->rb) { |
4469 | /* | |
4470 | * Should be impossible, we set this when removing | |
4471 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4472 | */ | |
4473 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4474 | |
b69cf536 | 4475 | old_rb = event->rb; |
b69cf536 PZ |
4476 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4477 | list_del_rcu(&event->rb_entry); | |
4478 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4479 | |
2f993cf0 ON |
4480 | event->rcu_batches = get_state_synchronize_rcu(); |
4481 | event->rcu_pending = 1; | |
b69cf536 | 4482 | } |
10c6db11 | 4483 | |
b69cf536 | 4484 | if (rb) { |
2f993cf0 ON |
4485 | if (event->rcu_pending) { |
4486 | cond_synchronize_rcu(event->rcu_batches); | |
4487 | event->rcu_pending = 0; | |
4488 | } | |
4489 | ||
b69cf536 PZ |
4490 | spin_lock_irqsave(&rb->event_lock, flags); |
4491 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4492 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4493 | } | |
4494 | ||
4495 | rcu_assign_pointer(event->rb, rb); | |
4496 | ||
4497 | if (old_rb) { | |
4498 | ring_buffer_put(old_rb); | |
4499 | /* | |
4500 | * Since we detached before setting the new rb, so that we | |
4501 | * could attach the new rb, we could have missed a wakeup. | |
4502 | * Provide it now. | |
4503 | */ | |
4504 | wake_up_all(&event->waitq); | |
4505 | } | |
10c6db11 PZ |
4506 | } |
4507 | ||
4508 | static void ring_buffer_wakeup(struct perf_event *event) | |
4509 | { | |
4510 | struct ring_buffer *rb; | |
4511 | ||
4512 | rcu_read_lock(); | |
4513 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4514 | if (rb) { |
4515 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4516 | wake_up_all(&event->waitq); | |
4517 | } | |
10c6db11 PZ |
4518 | rcu_read_unlock(); |
4519 | } | |
4520 | ||
fdc26706 | 4521 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4522 | { |
76369139 | 4523 | struct ring_buffer *rb; |
7b732a75 | 4524 | |
ac9721f3 | 4525 | rcu_read_lock(); |
76369139 FW |
4526 | rb = rcu_dereference(event->rb); |
4527 | if (rb) { | |
4528 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4529 | rb = NULL; | |
ac9721f3 PZ |
4530 | } |
4531 | rcu_read_unlock(); | |
4532 | ||
76369139 | 4533 | return rb; |
ac9721f3 PZ |
4534 | } |
4535 | ||
fdc26706 | 4536 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4537 | { |
76369139 | 4538 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4539 | return; |
7b732a75 | 4540 | |
9bb5d40c | 4541 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4542 | |
76369139 | 4543 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4544 | } |
4545 | ||
4546 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4547 | { | |
cdd6c482 | 4548 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4549 | |
cdd6c482 | 4550 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4551 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4552 | |
45bfb2e5 PZ |
4553 | if (vma->vm_pgoff) |
4554 | atomic_inc(&event->rb->aux_mmap_count); | |
4555 | ||
1e0fb9ec AL |
4556 | if (event->pmu->event_mapped) |
4557 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4558 | } |
4559 | ||
9bb5d40c PZ |
4560 | /* |
4561 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4562 | * event, or through other events by use of perf_event_set_output(). | |
4563 | * | |
4564 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4565 | * the buffer here, where we still have a VM context. This means we need | |
4566 | * to detach all events redirecting to us. | |
4567 | */ | |
7b732a75 PZ |
4568 | static void perf_mmap_close(struct vm_area_struct *vma) |
4569 | { | |
cdd6c482 | 4570 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4571 | |
b69cf536 | 4572 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4573 | struct user_struct *mmap_user = rb->mmap_user; |
4574 | int mmap_locked = rb->mmap_locked; | |
4575 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4576 | |
1e0fb9ec AL |
4577 | if (event->pmu->event_unmapped) |
4578 | event->pmu->event_unmapped(event); | |
4579 | ||
45bfb2e5 PZ |
4580 | /* |
4581 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4582 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4583 | * serialize with perf_mmap here. | |
4584 | */ | |
4585 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4586 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4587 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4588 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4589 | ||
4590 | rb_free_aux(rb); | |
4591 | mutex_unlock(&event->mmap_mutex); | |
4592 | } | |
4593 | ||
9bb5d40c PZ |
4594 | atomic_dec(&rb->mmap_count); |
4595 | ||
4596 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4597 | goto out_put; |
9bb5d40c | 4598 | |
b69cf536 | 4599 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4600 | mutex_unlock(&event->mmap_mutex); |
4601 | ||
4602 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4603 | if (atomic_read(&rb->mmap_count)) |
4604 | goto out_put; | |
ac9721f3 | 4605 | |
9bb5d40c PZ |
4606 | /* |
4607 | * No other mmap()s, detach from all other events that might redirect | |
4608 | * into the now unreachable buffer. Somewhat complicated by the | |
4609 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4610 | */ | |
4611 | again: | |
4612 | rcu_read_lock(); | |
4613 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4614 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4615 | /* | |
4616 | * This event is en-route to free_event() which will | |
4617 | * detach it and remove it from the list. | |
4618 | */ | |
4619 | continue; | |
4620 | } | |
4621 | rcu_read_unlock(); | |
789f90fc | 4622 | |
9bb5d40c PZ |
4623 | mutex_lock(&event->mmap_mutex); |
4624 | /* | |
4625 | * Check we didn't race with perf_event_set_output() which can | |
4626 | * swizzle the rb from under us while we were waiting to | |
4627 | * acquire mmap_mutex. | |
4628 | * | |
4629 | * If we find a different rb; ignore this event, a next | |
4630 | * iteration will no longer find it on the list. We have to | |
4631 | * still restart the iteration to make sure we're not now | |
4632 | * iterating the wrong list. | |
4633 | */ | |
b69cf536 PZ |
4634 | if (event->rb == rb) |
4635 | ring_buffer_attach(event, NULL); | |
4636 | ||
cdd6c482 | 4637 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4638 | put_event(event); |
ac9721f3 | 4639 | |
9bb5d40c PZ |
4640 | /* |
4641 | * Restart the iteration; either we're on the wrong list or | |
4642 | * destroyed its integrity by doing a deletion. | |
4643 | */ | |
4644 | goto again; | |
7b732a75 | 4645 | } |
9bb5d40c PZ |
4646 | rcu_read_unlock(); |
4647 | ||
4648 | /* | |
4649 | * It could be there's still a few 0-ref events on the list; they'll | |
4650 | * get cleaned up by free_event() -- they'll also still have their | |
4651 | * ref on the rb and will free it whenever they are done with it. | |
4652 | * | |
4653 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4654 | * undo the VM accounting. | |
4655 | */ | |
4656 | ||
4657 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4658 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4659 | free_uid(mmap_user); | |
4660 | ||
b69cf536 | 4661 | out_put: |
9bb5d40c | 4662 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4663 | } |
4664 | ||
f0f37e2f | 4665 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4666 | .open = perf_mmap_open, |
45bfb2e5 | 4667 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4668 | .fault = perf_mmap_fault, |
4669 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4670 | }; |
4671 | ||
4672 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4673 | { | |
cdd6c482 | 4674 | struct perf_event *event = file->private_data; |
22a4f650 | 4675 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4676 | struct user_struct *user = current_user(); |
22a4f650 | 4677 | unsigned long locked, lock_limit; |
45bfb2e5 | 4678 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4679 | unsigned long vma_size; |
4680 | unsigned long nr_pages; | |
45bfb2e5 | 4681 | long user_extra = 0, extra = 0; |
d57e34fd | 4682 | int ret = 0, flags = 0; |
37d81828 | 4683 | |
c7920614 PZ |
4684 | /* |
4685 | * Don't allow mmap() of inherited per-task counters. This would | |
4686 | * create a performance issue due to all children writing to the | |
76369139 | 4687 | * same rb. |
c7920614 PZ |
4688 | */ |
4689 | if (event->cpu == -1 && event->attr.inherit) | |
4690 | return -EINVAL; | |
4691 | ||
43a21ea8 | 4692 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4693 | return -EINVAL; |
7b732a75 PZ |
4694 | |
4695 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4696 | |
4697 | if (vma->vm_pgoff == 0) { | |
4698 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4699 | } else { | |
4700 | /* | |
4701 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4702 | * mapped, all subsequent mappings should have the same size | |
4703 | * and offset. Must be above the normal perf buffer. | |
4704 | */ | |
4705 | u64 aux_offset, aux_size; | |
4706 | ||
4707 | if (!event->rb) | |
4708 | return -EINVAL; | |
4709 | ||
4710 | nr_pages = vma_size / PAGE_SIZE; | |
4711 | ||
4712 | mutex_lock(&event->mmap_mutex); | |
4713 | ret = -EINVAL; | |
4714 | ||
4715 | rb = event->rb; | |
4716 | if (!rb) | |
4717 | goto aux_unlock; | |
4718 | ||
4719 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4720 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4721 | ||
4722 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4723 | goto aux_unlock; | |
4724 | ||
4725 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4726 | goto aux_unlock; | |
4727 | ||
4728 | /* already mapped with a different offset */ | |
4729 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4730 | goto aux_unlock; | |
4731 | ||
4732 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4733 | goto aux_unlock; | |
4734 | ||
4735 | /* already mapped with a different size */ | |
4736 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4737 | goto aux_unlock; | |
4738 | ||
4739 | if (!is_power_of_2(nr_pages)) | |
4740 | goto aux_unlock; | |
4741 | ||
4742 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4743 | goto aux_unlock; | |
4744 | ||
4745 | if (rb_has_aux(rb)) { | |
4746 | atomic_inc(&rb->aux_mmap_count); | |
4747 | ret = 0; | |
4748 | goto unlock; | |
4749 | } | |
4750 | ||
4751 | atomic_set(&rb->aux_mmap_count, 1); | |
4752 | user_extra = nr_pages; | |
4753 | ||
4754 | goto accounting; | |
4755 | } | |
7b732a75 | 4756 | |
7730d865 | 4757 | /* |
76369139 | 4758 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4759 | * can do bitmasks instead of modulo. |
4760 | */ | |
2ed11312 | 4761 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4762 | return -EINVAL; |
4763 | ||
7b732a75 | 4764 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4765 | return -EINVAL; |
4766 | ||
cdd6c482 | 4767 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4768 | again: |
cdd6c482 | 4769 | mutex_lock(&event->mmap_mutex); |
76369139 | 4770 | if (event->rb) { |
9bb5d40c | 4771 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4772 | ret = -EINVAL; |
9bb5d40c PZ |
4773 | goto unlock; |
4774 | } | |
4775 | ||
4776 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4777 | /* | |
4778 | * Raced against perf_mmap_close() through | |
4779 | * perf_event_set_output(). Try again, hope for better | |
4780 | * luck. | |
4781 | */ | |
4782 | mutex_unlock(&event->mmap_mutex); | |
4783 | goto again; | |
4784 | } | |
4785 | ||
ebb3c4c4 PZ |
4786 | goto unlock; |
4787 | } | |
4788 | ||
789f90fc | 4789 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4790 | |
4791 | accounting: | |
cdd6c482 | 4792 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4793 | |
4794 | /* | |
4795 | * Increase the limit linearly with more CPUs: | |
4796 | */ | |
4797 | user_lock_limit *= num_online_cpus(); | |
4798 | ||
789f90fc | 4799 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4800 | |
789f90fc PZ |
4801 | if (user_locked > user_lock_limit) |
4802 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4803 | |
78d7d407 | 4804 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4805 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4806 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4807 | |
459ec28a IM |
4808 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4809 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4810 | ret = -EPERM; |
4811 | goto unlock; | |
4812 | } | |
7b732a75 | 4813 | |
45bfb2e5 | 4814 | WARN_ON(!rb && event->rb); |
906010b2 | 4815 | |
d57e34fd | 4816 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4817 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4818 | |
76369139 | 4819 | if (!rb) { |
45bfb2e5 PZ |
4820 | rb = rb_alloc(nr_pages, |
4821 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4822 | event->cpu, flags); | |
26cb63ad | 4823 | |
45bfb2e5 PZ |
4824 | if (!rb) { |
4825 | ret = -ENOMEM; | |
4826 | goto unlock; | |
4827 | } | |
43a21ea8 | 4828 | |
45bfb2e5 PZ |
4829 | atomic_set(&rb->mmap_count, 1); |
4830 | rb->mmap_user = get_current_user(); | |
4831 | rb->mmap_locked = extra; | |
26cb63ad | 4832 | |
45bfb2e5 | 4833 | ring_buffer_attach(event, rb); |
ac9721f3 | 4834 | |
45bfb2e5 PZ |
4835 | perf_event_init_userpage(event); |
4836 | perf_event_update_userpage(event); | |
4837 | } else { | |
1a594131 AS |
4838 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4839 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4840 | if (!ret) |
4841 | rb->aux_mmap_locked = extra; | |
4842 | } | |
9a0f05cb | 4843 | |
ebb3c4c4 | 4844 | unlock: |
45bfb2e5 PZ |
4845 | if (!ret) { |
4846 | atomic_long_add(user_extra, &user->locked_vm); | |
4847 | vma->vm_mm->pinned_vm += extra; | |
4848 | ||
ac9721f3 | 4849 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4850 | } else if (rb) { |
4851 | atomic_dec(&rb->mmap_count); | |
4852 | } | |
4853 | aux_unlock: | |
cdd6c482 | 4854 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4855 | |
9bb5d40c PZ |
4856 | /* |
4857 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4858 | * vma. | |
4859 | */ | |
26cb63ad | 4860 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4861 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4862 | |
1e0fb9ec AL |
4863 | if (event->pmu->event_mapped) |
4864 | event->pmu->event_mapped(event); | |
4865 | ||
7b732a75 | 4866 | return ret; |
37d81828 PM |
4867 | } |
4868 | ||
3c446b3d PZ |
4869 | static int perf_fasync(int fd, struct file *filp, int on) |
4870 | { | |
496ad9aa | 4871 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4872 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4873 | int retval; |
4874 | ||
4875 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4876 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4877 | mutex_unlock(&inode->i_mutex); |
4878 | ||
4879 | if (retval < 0) | |
4880 | return retval; | |
4881 | ||
4882 | return 0; | |
4883 | } | |
4884 | ||
0793a61d | 4885 | static const struct file_operations perf_fops = { |
3326c1ce | 4886 | .llseek = no_llseek, |
0793a61d TG |
4887 | .release = perf_release, |
4888 | .read = perf_read, | |
4889 | .poll = perf_poll, | |
d859e29f | 4890 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4891 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4892 | .mmap = perf_mmap, |
3c446b3d | 4893 | .fasync = perf_fasync, |
0793a61d TG |
4894 | }; |
4895 | ||
925d519a | 4896 | /* |
cdd6c482 | 4897 | * Perf event wakeup |
925d519a PZ |
4898 | * |
4899 | * If there's data, ensure we set the poll() state and publish everything | |
4900 | * to user-space before waking everybody up. | |
4901 | */ | |
4902 | ||
fed66e2c PZ |
4903 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4904 | { | |
4905 | /* only the parent has fasync state */ | |
4906 | if (event->parent) | |
4907 | event = event->parent; | |
4908 | return &event->fasync; | |
4909 | } | |
4910 | ||
cdd6c482 | 4911 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4912 | { |
10c6db11 | 4913 | ring_buffer_wakeup(event); |
4c9e2542 | 4914 | |
cdd6c482 | 4915 | if (event->pending_kill) { |
fed66e2c | 4916 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4917 | event->pending_kill = 0; |
4c9e2542 | 4918 | } |
925d519a PZ |
4919 | } |
4920 | ||
e360adbe | 4921 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4922 | { |
cdd6c482 IM |
4923 | struct perf_event *event = container_of(entry, |
4924 | struct perf_event, pending); | |
d525211f PZ |
4925 | int rctx; |
4926 | ||
4927 | rctx = perf_swevent_get_recursion_context(); | |
4928 | /* | |
4929 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4930 | * and we won't recurse 'further'. | |
4931 | */ | |
79f14641 | 4932 | |
cdd6c482 IM |
4933 | if (event->pending_disable) { |
4934 | event->pending_disable = 0; | |
4935 | __perf_event_disable(event); | |
79f14641 PZ |
4936 | } |
4937 | ||
cdd6c482 IM |
4938 | if (event->pending_wakeup) { |
4939 | event->pending_wakeup = 0; | |
4940 | perf_event_wakeup(event); | |
79f14641 | 4941 | } |
d525211f PZ |
4942 | |
4943 | if (rctx >= 0) | |
4944 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4945 | } |
4946 | ||
39447b38 ZY |
4947 | /* |
4948 | * We assume there is only KVM supporting the callbacks. | |
4949 | * Later on, we might change it to a list if there is | |
4950 | * another virtualization implementation supporting the callbacks. | |
4951 | */ | |
4952 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4953 | ||
4954 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4955 | { | |
4956 | perf_guest_cbs = cbs; | |
4957 | return 0; | |
4958 | } | |
4959 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4960 | ||
4961 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4962 | { | |
4963 | perf_guest_cbs = NULL; | |
4964 | return 0; | |
4965 | } | |
4966 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4967 | ||
4018994f JO |
4968 | static void |
4969 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4970 | struct pt_regs *regs, u64 mask) | |
4971 | { | |
4972 | int bit; | |
4973 | ||
4974 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4975 | sizeof(mask) * BITS_PER_BYTE) { | |
4976 | u64 val; | |
4977 | ||
4978 | val = perf_reg_value(regs, bit); | |
4979 | perf_output_put(handle, val); | |
4980 | } | |
4981 | } | |
4982 | ||
60e2364e | 4983 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4984 | struct pt_regs *regs, |
4985 | struct pt_regs *regs_user_copy) | |
4018994f | 4986 | { |
88a7c26a AL |
4987 | if (user_mode(regs)) { |
4988 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4989 | regs_user->regs = regs; |
88a7c26a AL |
4990 | } else if (current->mm) { |
4991 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
4992 | } else { |
4993 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
4994 | regs_user->regs = NULL; | |
4018994f JO |
4995 | } |
4996 | } | |
4997 | ||
60e2364e SE |
4998 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
4999 | struct pt_regs *regs) | |
5000 | { | |
5001 | regs_intr->regs = regs; | |
5002 | regs_intr->abi = perf_reg_abi(current); | |
5003 | } | |
5004 | ||
5005 | ||
c5ebcedb JO |
5006 | /* |
5007 | * Get remaining task size from user stack pointer. | |
5008 | * | |
5009 | * It'd be better to take stack vma map and limit this more | |
5010 | * precisly, but there's no way to get it safely under interrupt, | |
5011 | * so using TASK_SIZE as limit. | |
5012 | */ | |
5013 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5014 | { | |
5015 | unsigned long addr = perf_user_stack_pointer(regs); | |
5016 | ||
5017 | if (!addr || addr >= TASK_SIZE) | |
5018 | return 0; | |
5019 | ||
5020 | return TASK_SIZE - addr; | |
5021 | } | |
5022 | ||
5023 | static u16 | |
5024 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5025 | struct pt_regs *regs) | |
5026 | { | |
5027 | u64 task_size; | |
5028 | ||
5029 | /* No regs, no stack pointer, no dump. */ | |
5030 | if (!regs) | |
5031 | return 0; | |
5032 | ||
5033 | /* | |
5034 | * Check if we fit in with the requested stack size into the: | |
5035 | * - TASK_SIZE | |
5036 | * If we don't, we limit the size to the TASK_SIZE. | |
5037 | * | |
5038 | * - remaining sample size | |
5039 | * If we don't, we customize the stack size to | |
5040 | * fit in to the remaining sample size. | |
5041 | */ | |
5042 | ||
5043 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5044 | stack_size = min(stack_size, (u16) task_size); | |
5045 | ||
5046 | /* Current header size plus static size and dynamic size. */ | |
5047 | header_size += 2 * sizeof(u64); | |
5048 | ||
5049 | /* Do we fit in with the current stack dump size? */ | |
5050 | if ((u16) (header_size + stack_size) < header_size) { | |
5051 | /* | |
5052 | * If we overflow the maximum size for the sample, | |
5053 | * we customize the stack dump size to fit in. | |
5054 | */ | |
5055 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5056 | stack_size = round_up(stack_size, sizeof(u64)); | |
5057 | } | |
5058 | ||
5059 | return stack_size; | |
5060 | } | |
5061 | ||
5062 | static void | |
5063 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5064 | struct pt_regs *regs) | |
5065 | { | |
5066 | /* Case of a kernel thread, nothing to dump */ | |
5067 | if (!regs) { | |
5068 | u64 size = 0; | |
5069 | perf_output_put(handle, size); | |
5070 | } else { | |
5071 | unsigned long sp; | |
5072 | unsigned int rem; | |
5073 | u64 dyn_size; | |
5074 | ||
5075 | /* | |
5076 | * We dump: | |
5077 | * static size | |
5078 | * - the size requested by user or the best one we can fit | |
5079 | * in to the sample max size | |
5080 | * data | |
5081 | * - user stack dump data | |
5082 | * dynamic size | |
5083 | * - the actual dumped size | |
5084 | */ | |
5085 | ||
5086 | /* Static size. */ | |
5087 | perf_output_put(handle, dump_size); | |
5088 | ||
5089 | /* Data. */ | |
5090 | sp = perf_user_stack_pointer(regs); | |
5091 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5092 | dyn_size = dump_size - rem; | |
5093 | ||
5094 | perf_output_skip(handle, rem); | |
5095 | ||
5096 | /* Dynamic size. */ | |
5097 | perf_output_put(handle, dyn_size); | |
5098 | } | |
5099 | } | |
5100 | ||
c980d109 ACM |
5101 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5102 | struct perf_sample_data *data, | |
5103 | struct perf_event *event) | |
6844c09d ACM |
5104 | { |
5105 | u64 sample_type = event->attr.sample_type; | |
5106 | ||
5107 | data->type = sample_type; | |
5108 | header->size += event->id_header_size; | |
5109 | ||
5110 | if (sample_type & PERF_SAMPLE_TID) { | |
5111 | /* namespace issues */ | |
5112 | data->tid_entry.pid = perf_event_pid(event, current); | |
5113 | data->tid_entry.tid = perf_event_tid(event, current); | |
5114 | } | |
5115 | ||
5116 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5117 | data->time = perf_event_clock(event); |
6844c09d | 5118 | |
ff3d527c | 5119 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5120 | data->id = primary_event_id(event); |
5121 | ||
5122 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5123 | data->stream_id = event->id; | |
5124 | ||
5125 | if (sample_type & PERF_SAMPLE_CPU) { | |
5126 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5127 | data->cpu_entry.reserved = 0; | |
5128 | } | |
5129 | } | |
5130 | ||
76369139 FW |
5131 | void perf_event_header__init_id(struct perf_event_header *header, |
5132 | struct perf_sample_data *data, | |
5133 | struct perf_event *event) | |
c980d109 ACM |
5134 | { |
5135 | if (event->attr.sample_id_all) | |
5136 | __perf_event_header__init_id(header, data, event); | |
5137 | } | |
5138 | ||
5139 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5140 | struct perf_sample_data *data) | |
5141 | { | |
5142 | u64 sample_type = data->type; | |
5143 | ||
5144 | if (sample_type & PERF_SAMPLE_TID) | |
5145 | perf_output_put(handle, data->tid_entry); | |
5146 | ||
5147 | if (sample_type & PERF_SAMPLE_TIME) | |
5148 | perf_output_put(handle, data->time); | |
5149 | ||
5150 | if (sample_type & PERF_SAMPLE_ID) | |
5151 | perf_output_put(handle, data->id); | |
5152 | ||
5153 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5154 | perf_output_put(handle, data->stream_id); | |
5155 | ||
5156 | if (sample_type & PERF_SAMPLE_CPU) | |
5157 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5158 | |
5159 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5160 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5161 | } |
5162 | ||
76369139 FW |
5163 | void perf_event__output_id_sample(struct perf_event *event, |
5164 | struct perf_output_handle *handle, | |
5165 | struct perf_sample_data *sample) | |
c980d109 ACM |
5166 | { |
5167 | if (event->attr.sample_id_all) | |
5168 | __perf_event__output_id_sample(handle, sample); | |
5169 | } | |
5170 | ||
3dab77fb | 5171 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5172 | struct perf_event *event, |
5173 | u64 enabled, u64 running) | |
3dab77fb | 5174 | { |
cdd6c482 | 5175 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5176 | u64 values[4]; |
5177 | int n = 0; | |
5178 | ||
b5e58793 | 5179 | values[n++] = perf_event_count(event); |
3dab77fb | 5180 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5181 | values[n++] = enabled + |
cdd6c482 | 5182 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5183 | } |
5184 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5185 | values[n++] = running + |
cdd6c482 | 5186 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5187 | } |
5188 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5189 | values[n++] = primary_event_id(event); |
3dab77fb | 5190 | |
76369139 | 5191 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5192 | } |
5193 | ||
5194 | /* | |
cdd6c482 | 5195 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5196 | */ |
5197 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5198 | struct perf_event *event, |
5199 | u64 enabled, u64 running) | |
3dab77fb | 5200 | { |
cdd6c482 IM |
5201 | struct perf_event *leader = event->group_leader, *sub; |
5202 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5203 | u64 values[5]; |
5204 | int n = 0; | |
5205 | ||
5206 | values[n++] = 1 + leader->nr_siblings; | |
5207 | ||
5208 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5209 | values[n++] = enabled; |
3dab77fb PZ |
5210 | |
5211 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5212 | values[n++] = running; |
3dab77fb | 5213 | |
cdd6c482 | 5214 | if (leader != event) |
3dab77fb PZ |
5215 | leader->pmu->read(leader); |
5216 | ||
b5e58793 | 5217 | values[n++] = perf_event_count(leader); |
3dab77fb | 5218 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5219 | values[n++] = primary_event_id(leader); |
3dab77fb | 5220 | |
76369139 | 5221 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5222 | |
65abc865 | 5223 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5224 | n = 0; |
5225 | ||
6f5ab001 JO |
5226 | if ((sub != event) && |
5227 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5228 | sub->pmu->read(sub); |
5229 | ||
b5e58793 | 5230 | values[n++] = perf_event_count(sub); |
3dab77fb | 5231 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5232 | values[n++] = primary_event_id(sub); |
3dab77fb | 5233 | |
76369139 | 5234 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5235 | } |
5236 | } | |
5237 | ||
eed01528 SE |
5238 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5239 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5240 | ||
3dab77fb | 5241 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5242 | struct perf_event *event) |
3dab77fb | 5243 | { |
e3f3541c | 5244 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5245 | u64 read_format = event->attr.read_format; |
5246 | ||
5247 | /* | |
5248 | * compute total_time_enabled, total_time_running | |
5249 | * based on snapshot values taken when the event | |
5250 | * was last scheduled in. | |
5251 | * | |
5252 | * we cannot simply called update_context_time() | |
5253 | * because of locking issue as we are called in | |
5254 | * NMI context | |
5255 | */ | |
c4794295 | 5256 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5257 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5258 | |
cdd6c482 | 5259 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5260 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5261 | else |
eed01528 | 5262 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5263 | } |
5264 | ||
5622f295 MM |
5265 | void perf_output_sample(struct perf_output_handle *handle, |
5266 | struct perf_event_header *header, | |
5267 | struct perf_sample_data *data, | |
cdd6c482 | 5268 | struct perf_event *event) |
5622f295 MM |
5269 | { |
5270 | u64 sample_type = data->type; | |
5271 | ||
5272 | perf_output_put(handle, *header); | |
5273 | ||
ff3d527c AH |
5274 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5275 | perf_output_put(handle, data->id); | |
5276 | ||
5622f295 MM |
5277 | if (sample_type & PERF_SAMPLE_IP) |
5278 | perf_output_put(handle, data->ip); | |
5279 | ||
5280 | if (sample_type & PERF_SAMPLE_TID) | |
5281 | perf_output_put(handle, data->tid_entry); | |
5282 | ||
5283 | if (sample_type & PERF_SAMPLE_TIME) | |
5284 | perf_output_put(handle, data->time); | |
5285 | ||
5286 | if (sample_type & PERF_SAMPLE_ADDR) | |
5287 | perf_output_put(handle, data->addr); | |
5288 | ||
5289 | if (sample_type & PERF_SAMPLE_ID) | |
5290 | perf_output_put(handle, data->id); | |
5291 | ||
5292 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5293 | perf_output_put(handle, data->stream_id); | |
5294 | ||
5295 | if (sample_type & PERF_SAMPLE_CPU) | |
5296 | perf_output_put(handle, data->cpu_entry); | |
5297 | ||
5298 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5299 | perf_output_put(handle, data->period); | |
5300 | ||
5301 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5302 | perf_output_read(handle, event); |
5622f295 MM |
5303 | |
5304 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5305 | if (data->callchain) { | |
5306 | int size = 1; | |
5307 | ||
5308 | if (data->callchain) | |
5309 | size += data->callchain->nr; | |
5310 | ||
5311 | size *= sizeof(u64); | |
5312 | ||
76369139 | 5313 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5314 | } else { |
5315 | u64 nr = 0; | |
5316 | perf_output_put(handle, nr); | |
5317 | } | |
5318 | } | |
5319 | ||
5320 | if (sample_type & PERF_SAMPLE_RAW) { | |
5321 | if (data->raw) { | |
fa128e6a AS |
5322 | u32 raw_size = data->raw->size; |
5323 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5324 | sizeof(u64)) - sizeof(u32); | |
5325 | u64 zero = 0; | |
5326 | ||
5327 | perf_output_put(handle, real_size); | |
5328 | __output_copy(handle, data->raw->data, raw_size); | |
5329 | if (real_size - raw_size) | |
5330 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5331 | } else { |
5332 | struct { | |
5333 | u32 size; | |
5334 | u32 data; | |
5335 | } raw = { | |
5336 | .size = sizeof(u32), | |
5337 | .data = 0, | |
5338 | }; | |
5339 | perf_output_put(handle, raw); | |
5340 | } | |
5341 | } | |
a7ac67ea | 5342 | |
bce38cd5 SE |
5343 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5344 | if (data->br_stack) { | |
5345 | size_t size; | |
5346 | ||
5347 | size = data->br_stack->nr | |
5348 | * sizeof(struct perf_branch_entry); | |
5349 | ||
5350 | perf_output_put(handle, data->br_stack->nr); | |
5351 | perf_output_copy(handle, data->br_stack->entries, size); | |
5352 | } else { | |
5353 | /* | |
5354 | * we always store at least the value of nr | |
5355 | */ | |
5356 | u64 nr = 0; | |
5357 | perf_output_put(handle, nr); | |
5358 | } | |
5359 | } | |
4018994f JO |
5360 | |
5361 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5362 | u64 abi = data->regs_user.abi; | |
5363 | ||
5364 | /* | |
5365 | * If there are no regs to dump, notice it through | |
5366 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5367 | */ | |
5368 | perf_output_put(handle, abi); | |
5369 | ||
5370 | if (abi) { | |
5371 | u64 mask = event->attr.sample_regs_user; | |
5372 | perf_output_sample_regs(handle, | |
5373 | data->regs_user.regs, | |
5374 | mask); | |
5375 | } | |
5376 | } | |
c5ebcedb | 5377 | |
a5cdd40c | 5378 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5379 | perf_output_sample_ustack(handle, |
5380 | data->stack_user_size, | |
5381 | data->regs_user.regs); | |
a5cdd40c | 5382 | } |
c3feedf2 AK |
5383 | |
5384 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5385 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5386 | |
5387 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5388 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5389 | |
fdfbbd07 AK |
5390 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5391 | perf_output_put(handle, data->txn); | |
5392 | ||
60e2364e SE |
5393 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5394 | u64 abi = data->regs_intr.abi; | |
5395 | /* | |
5396 | * If there are no regs to dump, notice it through | |
5397 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5398 | */ | |
5399 | perf_output_put(handle, abi); | |
5400 | ||
5401 | if (abi) { | |
5402 | u64 mask = event->attr.sample_regs_intr; | |
5403 | ||
5404 | perf_output_sample_regs(handle, | |
5405 | data->regs_intr.regs, | |
5406 | mask); | |
5407 | } | |
5408 | } | |
5409 | ||
a5cdd40c PZ |
5410 | if (!event->attr.watermark) { |
5411 | int wakeup_events = event->attr.wakeup_events; | |
5412 | ||
5413 | if (wakeup_events) { | |
5414 | struct ring_buffer *rb = handle->rb; | |
5415 | int events = local_inc_return(&rb->events); | |
5416 | ||
5417 | if (events >= wakeup_events) { | |
5418 | local_sub(wakeup_events, &rb->events); | |
5419 | local_inc(&rb->wakeup); | |
5420 | } | |
5421 | } | |
5422 | } | |
5622f295 MM |
5423 | } |
5424 | ||
5425 | void perf_prepare_sample(struct perf_event_header *header, | |
5426 | struct perf_sample_data *data, | |
cdd6c482 | 5427 | struct perf_event *event, |
5622f295 | 5428 | struct pt_regs *regs) |
7b732a75 | 5429 | { |
cdd6c482 | 5430 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5431 | |
cdd6c482 | 5432 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5433 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5434 | |
5435 | header->misc = 0; | |
5436 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5437 | |
c980d109 | 5438 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5439 | |
c320c7b7 | 5440 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5441 | data->ip = perf_instruction_pointer(regs); |
5442 | ||
b23f3325 | 5443 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5444 | int size = 1; |
394ee076 | 5445 | |
e6dab5ff | 5446 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5447 | |
5448 | if (data->callchain) | |
5449 | size += data->callchain->nr; | |
5450 | ||
5451 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5452 | } |
5453 | ||
3a43ce68 | 5454 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5455 | int size = sizeof(u32); |
5456 | ||
5457 | if (data->raw) | |
5458 | size += data->raw->size; | |
5459 | else | |
5460 | size += sizeof(u32); | |
5461 | ||
fa128e6a | 5462 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5463 | } |
bce38cd5 SE |
5464 | |
5465 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5466 | int size = sizeof(u64); /* nr */ | |
5467 | if (data->br_stack) { | |
5468 | size += data->br_stack->nr | |
5469 | * sizeof(struct perf_branch_entry); | |
5470 | } | |
5471 | header->size += size; | |
5472 | } | |
4018994f | 5473 | |
2565711f | 5474 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5475 | perf_sample_regs_user(&data->regs_user, regs, |
5476 | &data->regs_user_copy); | |
2565711f | 5477 | |
4018994f JO |
5478 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5479 | /* regs dump ABI info */ | |
5480 | int size = sizeof(u64); | |
5481 | ||
4018994f JO |
5482 | if (data->regs_user.regs) { |
5483 | u64 mask = event->attr.sample_regs_user; | |
5484 | size += hweight64(mask) * sizeof(u64); | |
5485 | } | |
5486 | ||
5487 | header->size += size; | |
5488 | } | |
c5ebcedb JO |
5489 | |
5490 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5491 | /* | |
5492 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5493 | * processed as the last one or have additional check added | |
5494 | * in case new sample type is added, because we could eat | |
5495 | * up the rest of the sample size. | |
5496 | */ | |
c5ebcedb JO |
5497 | u16 stack_size = event->attr.sample_stack_user; |
5498 | u16 size = sizeof(u64); | |
5499 | ||
c5ebcedb | 5500 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5501 | data->regs_user.regs); |
c5ebcedb JO |
5502 | |
5503 | /* | |
5504 | * If there is something to dump, add space for the dump | |
5505 | * itself and for the field that tells the dynamic size, | |
5506 | * which is how many have been actually dumped. | |
5507 | */ | |
5508 | if (stack_size) | |
5509 | size += sizeof(u64) + stack_size; | |
5510 | ||
5511 | data->stack_user_size = stack_size; | |
5512 | header->size += size; | |
5513 | } | |
60e2364e SE |
5514 | |
5515 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5516 | /* regs dump ABI info */ | |
5517 | int size = sizeof(u64); | |
5518 | ||
5519 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5520 | ||
5521 | if (data->regs_intr.regs) { | |
5522 | u64 mask = event->attr.sample_regs_intr; | |
5523 | ||
5524 | size += hweight64(mask) * sizeof(u64); | |
5525 | } | |
5526 | ||
5527 | header->size += size; | |
5528 | } | |
5622f295 | 5529 | } |
7f453c24 | 5530 | |
21509084 YZ |
5531 | void perf_event_output(struct perf_event *event, |
5532 | struct perf_sample_data *data, | |
5533 | struct pt_regs *regs) | |
5622f295 MM |
5534 | { |
5535 | struct perf_output_handle handle; | |
5536 | struct perf_event_header header; | |
689802b2 | 5537 | |
927c7a9e FW |
5538 | /* protect the callchain buffers */ |
5539 | rcu_read_lock(); | |
5540 | ||
cdd6c482 | 5541 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5542 | |
a7ac67ea | 5543 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5544 | goto exit; |
0322cd6e | 5545 | |
cdd6c482 | 5546 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5547 | |
8a057d84 | 5548 | perf_output_end(&handle); |
927c7a9e FW |
5549 | |
5550 | exit: | |
5551 | rcu_read_unlock(); | |
0322cd6e PZ |
5552 | } |
5553 | ||
38b200d6 | 5554 | /* |
cdd6c482 | 5555 | * read event_id |
38b200d6 PZ |
5556 | */ |
5557 | ||
5558 | struct perf_read_event { | |
5559 | struct perf_event_header header; | |
5560 | ||
5561 | u32 pid; | |
5562 | u32 tid; | |
38b200d6 PZ |
5563 | }; |
5564 | ||
5565 | static void | |
cdd6c482 | 5566 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5567 | struct task_struct *task) |
5568 | { | |
5569 | struct perf_output_handle handle; | |
c980d109 | 5570 | struct perf_sample_data sample; |
dfc65094 | 5571 | struct perf_read_event read_event = { |
38b200d6 | 5572 | .header = { |
cdd6c482 | 5573 | .type = PERF_RECORD_READ, |
38b200d6 | 5574 | .misc = 0, |
c320c7b7 | 5575 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5576 | }, |
cdd6c482 IM |
5577 | .pid = perf_event_pid(event, task), |
5578 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5579 | }; |
3dab77fb | 5580 | int ret; |
38b200d6 | 5581 | |
c980d109 | 5582 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5583 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5584 | if (ret) |
5585 | return; | |
5586 | ||
dfc65094 | 5587 | perf_output_put(&handle, read_event); |
cdd6c482 | 5588 | perf_output_read(&handle, event); |
c980d109 | 5589 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5590 | |
38b200d6 PZ |
5591 | perf_output_end(&handle); |
5592 | } | |
5593 | ||
52d857a8 JO |
5594 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5595 | ||
5596 | static void | |
5597 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5598 | perf_event_aux_output_cb output, |
5599 | void *data) | |
5600 | { | |
5601 | struct perf_event *event; | |
5602 | ||
5603 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5604 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5605 | continue; | |
5606 | if (!event_filter_match(event)) | |
5607 | continue; | |
67516844 | 5608 | output(event, data); |
52d857a8 JO |
5609 | } |
5610 | } | |
5611 | ||
4e93ad60 JO |
5612 | static void |
5613 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5614 | struct perf_event_context *task_ctx) | |
5615 | { | |
5616 | rcu_read_lock(); | |
5617 | preempt_disable(); | |
5618 | perf_event_aux_ctx(task_ctx, output, data); | |
5619 | preempt_enable(); | |
5620 | rcu_read_unlock(); | |
5621 | } | |
5622 | ||
52d857a8 | 5623 | static void |
67516844 | 5624 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5625 | struct perf_event_context *task_ctx) |
5626 | { | |
5627 | struct perf_cpu_context *cpuctx; | |
5628 | struct perf_event_context *ctx; | |
5629 | struct pmu *pmu; | |
5630 | int ctxn; | |
5631 | ||
4e93ad60 JO |
5632 | /* |
5633 | * If we have task_ctx != NULL we only notify | |
5634 | * the task context itself. The task_ctx is set | |
5635 | * only for EXIT events before releasing task | |
5636 | * context. | |
5637 | */ | |
5638 | if (task_ctx) { | |
5639 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5640 | return; | |
5641 | } | |
5642 | ||
52d857a8 JO |
5643 | rcu_read_lock(); |
5644 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5645 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5646 | if (cpuctx->unique_pmu != pmu) | |
5647 | goto next; | |
67516844 | 5648 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5649 | ctxn = pmu->task_ctx_nr; |
5650 | if (ctxn < 0) | |
5651 | goto next; | |
5652 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5653 | if (ctx) | |
67516844 | 5654 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5655 | next: |
5656 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5657 | } | |
52d857a8 JO |
5658 | rcu_read_unlock(); |
5659 | } | |
5660 | ||
60313ebe | 5661 | /* |
9f498cc5 PZ |
5662 | * task tracking -- fork/exit |
5663 | * | |
13d7a241 | 5664 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5665 | */ |
5666 | ||
9f498cc5 | 5667 | struct perf_task_event { |
3a80b4a3 | 5668 | struct task_struct *task; |
cdd6c482 | 5669 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5670 | |
5671 | struct { | |
5672 | struct perf_event_header header; | |
5673 | ||
5674 | u32 pid; | |
5675 | u32 ppid; | |
9f498cc5 PZ |
5676 | u32 tid; |
5677 | u32 ptid; | |
393b2ad8 | 5678 | u64 time; |
cdd6c482 | 5679 | } event_id; |
60313ebe PZ |
5680 | }; |
5681 | ||
67516844 JO |
5682 | static int perf_event_task_match(struct perf_event *event) |
5683 | { | |
13d7a241 SE |
5684 | return event->attr.comm || event->attr.mmap || |
5685 | event->attr.mmap2 || event->attr.mmap_data || | |
5686 | event->attr.task; | |
67516844 JO |
5687 | } |
5688 | ||
cdd6c482 | 5689 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5690 | void *data) |
60313ebe | 5691 | { |
52d857a8 | 5692 | struct perf_task_event *task_event = data; |
60313ebe | 5693 | struct perf_output_handle handle; |
c980d109 | 5694 | struct perf_sample_data sample; |
9f498cc5 | 5695 | struct task_struct *task = task_event->task; |
c980d109 | 5696 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5697 | |
67516844 JO |
5698 | if (!perf_event_task_match(event)) |
5699 | return; | |
5700 | ||
c980d109 | 5701 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5702 | |
c980d109 | 5703 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5704 | task_event->event_id.header.size); |
ef60777c | 5705 | if (ret) |
c980d109 | 5706 | goto out; |
60313ebe | 5707 | |
cdd6c482 IM |
5708 | task_event->event_id.pid = perf_event_pid(event, task); |
5709 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5710 | |
cdd6c482 IM |
5711 | task_event->event_id.tid = perf_event_tid(event, task); |
5712 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5713 | |
34f43927 PZ |
5714 | task_event->event_id.time = perf_event_clock(event); |
5715 | ||
cdd6c482 | 5716 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5717 | |
c980d109 ACM |
5718 | perf_event__output_id_sample(event, &handle, &sample); |
5719 | ||
60313ebe | 5720 | perf_output_end(&handle); |
c980d109 ACM |
5721 | out: |
5722 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5723 | } |
5724 | ||
cdd6c482 IM |
5725 | static void perf_event_task(struct task_struct *task, |
5726 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5727 | int new) |
60313ebe | 5728 | { |
9f498cc5 | 5729 | struct perf_task_event task_event; |
60313ebe | 5730 | |
cdd6c482 IM |
5731 | if (!atomic_read(&nr_comm_events) && |
5732 | !atomic_read(&nr_mmap_events) && | |
5733 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5734 | return; |
5735 | ||
9f498cc5 | 5736 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5737 | .task = task, |
5738 | .task_ctx = task_ctx, | |
cdd6c482 | 5739 | .event_id = { |
60313ebe | 5740 | .header = { |
cdd6c482 | 5741 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5742 | .misc = 0, |
cdd6c482 | 5743 | .size = sizeof(task_event.event_id), |
60313ebe | 5744 | }, |
573402db PZ |
5745 | /* .pid */ |
5746 | /* .ppid */ | |
9f498cc5 PZ |
5747 | /* .tid */ |
5748 | /* .ptid */ | |
34f43927 | 5749 | /* .time */ |
60313ebe PZ |
5750 | }, |
5751 | }; | |
5752 | ||
67516844 | 5753 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5754 | &task_event, |
5755 | task_ctx); | |
9f498cc5 PZ |
5756 | } |
5757 | ||
cdd6c482 | 5758 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5759 | { |
cdd6c482 | 5760 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5761 | } |
5762 | ||
8d1b2d93 PZ |
5763 | /* |
5764 | * comm tracking | |
5765 | */ | |
5766 | ||
5767 | struct perf_comm_event { | |
22a4f650 IM |
5768 | struct task_struct *task; |
5769 | char *comm; | |
8d1b2d93 PZ |
5770 | int comm_size; |
5771 | ||
5772 | struct { | |
5773 | struct perf_event_header header; | |
5774 | ||
5775 | u32 pid; | |
5776 | u32 tid; | |
cdd6c482 | 5777 | } event_id; |
8d1b2d93 PZ |
5778 | }; |
5779 | ||
67516844 JO |
5780 | static int perf_event_comm_match(struct perf_event *event) |
5781 | { | |
5782 | return event->attr.comm; | |
5783 | } | |
5784 | ||
cdd6c482 | 5785 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5786 | void *data) |
8d1b2d93 | 5787 | { |
52d857a8 | 5788 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5789 | struct perf_output_handle handle; |
c980d109 | 5790 | struct perf_sample_data sample; |
cdd6c482 | 5791 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5792 | int ret; |
5793 | ||
67516844 JO |
5794 | if (!perf_event_comm_match(event)) |
5795 | return; | |
5796 | ||
c980d109 ACM |
5797 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5798 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5799 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5800 | |
5801 | if (ret) | |
c980d109 | 5802 | goto out; |
8d1b2d93 | 5803 | |
cdd6c482 IM |
5804 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5805 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5806 | |
cdd6c482 | 5807 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5808 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5809 | comm_event->comm_size); |
c980d109 ACM |
5810 | |
5811 | perf_event__output_id_sample(event, &handle, &sample); | |
5812 | ||
8d1b2d93 | 5813 | perf_output_end(&handle); |
c980d109 ACM |
5814 | out: |
5815 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5816 | } |
5817 | ||
cdd6c482 | 5818 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5819 | { |
413ee3b4 | 5820 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5821 | unsigned int size; |
8d1b2d93 | 5822 | |
413ee3b4 | 5823 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5824 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5825 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5826 | |
5827 | comm_event->comm = comm; | |
5828 | comm_event->comm_size = size; | |
5829 | ||
cdd6c482 | 5830 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5831 | |
67516844 | 5832 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5833 | comm_event, |
5834 | NULL); | |
8d1b2d93 PZ |
5835 | } |
5836 | ||
82b89778 | 5837 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5838 | { |
9ee318a7 PZ |
5839 | struct perf_comm_event comm_event; |
5840 | ||
cdd6c482 | 5841 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5842 | return; |
a63eaf34 | 5843 | |
9ee318a7 | 5844 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5845 | .task = task, |
573402db PZ |
5846 | /* .comm */ |
5847 | /* .comm_size */ | |
cdd6c482 | 5848 | .event_id = { |
573402db | 5849 | .header = { |
cdd6c482 | 5850 | .type = PERF_RECORD_COMM, |
82b89778 | 5851 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5852 | /* .size */ |
5853 | }, | |
5854 | /* .pid */ | |
5855 | /* .tid */ | |
8d1b2d93 PZ |
5856 | }, |
5857 | }; | |
5858 | ||
cdd6c482 | 5859 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5860 | } |
5861 | ||
0a4a9391 PZ |
5862 | /* |
5863 | * mmap tracking | |
5864 | */ | |
5865 | ||
5866 | struct perf_mmap_event { | |
089dd79d PZ |
5867 | struct vm_area_struct *vma; |
5868 | ||
5869 | const char *file_name; | |
5870 | int file_size; | |
13d7a241 SE |
5871 | int maj, min; |
5872 | u64 ino; | |
5873 | u64 ino_generation; | |
f972eb63 | 5874 | u32 prot, flags; |
0a4a9391 PZ |
5875 | |
5876 | struct { | |
5877 | struct perf_event_header header; | |
5878 | ||
5879 | u32 pid; | |
5880 | u32 tid; | |
5881 | u64 start; | |
5882 | u64 len; | |
5883 | u64 pgoff; | |
cdd6c482 | 5884 | } event_id; |
0a4a9391 PZ |
5885 | }; |
5886 | ||
67516844 JO |
5887 | static int perf_event_mmap_match(struct perf_event *event, |
5888 | void *data) | |
5889 | { | |
5890 | struct perf_mmap_event *mmap_event = data; | |
5891 | struct vm_area_struct *vma = mmap_event->vma; | |
5892 | int executable = vma->vm_flags & VM_EXEC; | |
5893 | ||
5894 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5895 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5896 | } |
5897 | ||
cdd6c482 | 5898 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5899 | void *data) |
0a4a9391 | 5900 | { |
52d857a8 | 5901 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5902 | struct perf_output_handle handle; |
c980d109 | 5903 | struct perf_sample_data sample; |
cdd6c482 | 5904 | int size = mmap_event->event_id.header.size; |
c980d109 | 5905 | int ret; |
0a4a9391 | 5906 | |
67516844 JO |
5907 | if (!perf_event_mmap_match(event, data)) |
5908 | return; | |
5909 | ||
13d7a241 SE |
5910 | if (event->attr.mmap2) { |
5911 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5912 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5913 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5914 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5915 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5916 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5917 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5918 | } |
5919 | ||
c980d109 ACM |
5920 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5921 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5922 | mmap_event->event_id.header.size); |
0a4a9391 | 5923 | if (ret) |
c980d109 | 5924 | goto out; |
0a4a9391 | 5925 | |
cdd6c482 IM |
5926 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5927 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5928 | |
cdd6c482 | 5929 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5930 | |
5931 | if (event->attr.mmap2) { | |
5932 | perf_output_put(&handle, mmap_event->maj); | |
5933 | perf_output_put(&handle, mmap_event->min); | |
5934 | perf_output_put(&handle, mmap_event->ino); | |
5935 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5936 | perf_output_put(&handle, mmap_event->prot); |
5937 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5938 | } |
5939 | ||
76369139 | 5940 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5941 | mmap_event->file_size); |
c980d109 ACM |
5942 | |
5943 | perf_event__output_id_sample(event, &handle, &sample); | |
5944 | ||
78d613eb | 5945 | perf_output_end(&handle); |
c980d109 ACM |
5946 | out: |
5947 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5948 | } |
5949 | ||
cdd6c482 | 5950 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5951 | { |
089dd79d PZ |
5952 | struct vm_area_struct *vma = mmap_event->vma; |
5953 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5954 | int maj = 0, min = 0; |
5955 | u64 ino = 0, gen = 0; | |
f972eb63 | 5956 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5957 | unsigned int size; |
5958 | char tmp[16]; | |
5959 | char *buf = NULL; | |
2c42cfbf | 5960 | char *name; |
413ee3b4 | 5961 | |
0a4a9391 | 5962 | if (file) { |
13d7a241 SE |
5963 | struct inode *inode; |
5964 | dev_t dev; | |
3ea2f2b9 | 5965 | |
2c42cfbf | 5966 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5967 | if (!buf) { |
c7e548b4 ON |
5968 | name = "//enomem"; |
5969 | goto cpy_name; | |
0a4a9391 | 5970 | } |
413ee3b4 | 5971 | /* |
3ea2f2b9 | 5972 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5973 | * need to add enough zero bytes after the string to handle |
5974 | * the 64bit alignment we do later. | |
5975 | */ | |
9bf39ab2 | 5976 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5977 | if (IS_ERR(name)) { |
c7e548b4 ON |
5978 | name = "//toolong"; |
5979 | goto cpy_name; | |
0a4a9391 | 5980 | } |
13d7a241 SE |
5981 | inode = file_inode(vma->vm_file); |
5982 | dev = inode->i_sb->s_dev; | |
5983 | ino = inode->i_ino; | |
5984 | gen = inode->i_generation; | |
5985 | maj = MAJOR(dev); | |
5986 | min = MINOR(dev); | |
f972eb63 PZ |
5987 | |
5988 | if (vma->vm_flags & VM_READ) | |
5989 | prot |= PROT_READ; | |
5990 | if (vma->vm_flags & VM_WRITE) | |
5991 | prot |= PROT_WRITE; | |
5992 | if (vma->vm_flags & VM_EXEC) | |
5993 | prot |= PROT_EXEC; | |
5994 | ||
5995 | if (vma->vm_flags & VM_MAYSHARE) | |
5996 | flags = MAP_SHARED; | |
5997 | else | |
5998 | flags = MAP_PRIVATE; | |
5999 | ||
6000 | if (vma->vm_flags & VM_DENYWRITE) | |
6001 | flags |= MAP_DENYWRITE; | |
6002 | if (vma->vm_flags & VM_MAYEXEC) | |
6003 | flags |= MAP_EXECUTABLE; | |
6004 | if (vma->vm_flags & VM_LOCKED) | |
6005 | flags |= MAP_LOCKED; | |
6006 | if (vma->vm_flags & VM_HUGETLB) | |
6007 | flags |= MAP_HUGETLB; | |
6008 | ||
c7e548b4 | 6009 | goto got_name; |
0a4a9391 | 6010 | } else { |
fbe26abe JO |
6011 | if (vma->vm_ops && vma->vm_ops->name) { |
6012 | name = (char *) vma->vm_ops->name(vma); | |
6013 | if (name) | |
6014 | goto cpy_name; | |
6015 | } | |
6016 | ||
2c42cfbf | 6017 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6018 | if (name) |
6019 | goto cpy_name; | |
089dd79d | 6020 | |
32c5fb7e | 6021 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6022 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6023 | name = "[heap]"; |
6024 | goto cpy_name; | |
32c5fb7e ON |
6025 | } |
6026 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6027 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6028 | name = "[stack]"; |
6029 | goto cpy_name; | |
089dd79d PZ |
6030 | } |
6031 | ||
c7e548b4 ON |
6032 | name = "//anon"; |
6033 | goto cpy_name; | |
0a4a9391 PZ |
6034 | } |
6035 | ||
c7e548b4 ON |
6036 | cpy_name: |
6037 | strlcpy(tmp, name, sizeof(tmp)); | |
6038 | name = tmp; | |
0a4a9391 | 6039 | got_name: |
2c42cfbf PZ |
6040 | /* |
6041 | * Since our buffer works in 8 byte units we need to align our string | |
6042 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6043 | * zero'd out to avoid leaking random bits to userspace. | |
6044 | */ | |
6045 | size = strlen(name)+1; | |
6046 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6047 | name[size++] = '\0'; | |
0a4a9391 PZ |
6048 | |
6049 | mmap_event->file_name = name; | |
6050 | mmap_event->file_size = size; | |
13d7a241 SE |
6051 | mmap_event->maj = maj; |
6052 | mmap_event->min = min; | |
6053 | mmap_event->ino = ino; | |
6054 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6055 | mmap_event->prot = prot; |
6056 | mmap_event->flags = flags; | |
0a4a9391 | 6057 | |
2fe85427 SE |
6058 | if (!(vma->vm_flags & VM_EXEC)) |
6059 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6060 | ||
cdd6c482 | 6061 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6062 | |
67516844 | 6063 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6064 | mmap_event, |
6065 | NULL); | |
665c2142 | 6066 | |
0a4a9391 PZ |
6067 | kfree(buf); |
6068 | } | |
6069 | ||
3af9e859 | 6070 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6071 | { |
9ee318a7 PZ |
6072 | struct perf_mmap_event mmap_event; |
6073 | ||
cdd6c482 | 6074 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6075 | return; |
6076 | ||
6077 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6078 | .vma = vma, |
573402db PZ |
6079 | /* .file_name */ |
6080 | /* .file_size */ | |
cdd6c482 | 6081 | .event_id = { |
573402db | 6082 | .header = { |
cdd6c482 | 6083 | .type = PERF_RECORD_MMAP, |
39447b38 | 6084 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6085 | /* .size */ |
6086 | }, | |
6087 | /* .pid */ | |
6088 | /* .tid */ | |
089dd79d PZ |
6089 | .start = vma->vm_start, |
6090 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6091 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6092 | }, |
13d7a241 SE |
6093 | /* .maj (attr_mmap2 only) */ |
6094 | /* .min (attr_mmap2 only) */ | |
6095 | /* .ino (attr_mmap2 only) */ | |
6096 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6097 | /* .prot (attr_mmap2 only) */ |
6098 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6099 | }; |
6100 | ||
cdd6c482 | 6101 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6102 | } |
6103 | ||
68db7e98 AS |
6104 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6105 | unsigned long size, u64 flags) | |
6106 | { | |
6107 | struct perf_output_handle handle; | |
6108 | struct perf_sample_data sample; | |
6109 | struct perf_aux_event { | |
6110 | struct perf_event_header header; | |
6111 | u64 offset; | |
6112 | u64 size; | |
6113 | u64 flags; | |
6114 | } rec = { | |
6115 | .header = { | |
6116 | .type = PERF_RECORD_AUX, | |
6117 | .misc = 0, | |
6118 | .size = sizeof(rec), | |
6119 | }, | |
6120 | .offset = head, | |
6121 | .size = size, | |
6122 | .flags = flags, | |
6123 | }; | |
6124 | int ret; | |
6125 | ||
6126 | perf_event_header__init_id(&rec.header, &sample, event); | |
6127 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6128 | ||
6129 | if (ret) | |
6130 | return; | |
6131 | ||
6132 | perf_output_put(&handle, rec); | |
6133 | perf_event__output_id_sample(event, &handle, &sample); | |
6134 | ||
6135 | perf_output_end(&handle); | |
6136 | } | |
6137 | ||
f38b0dbb KL |
6138 | /* |
6139 | * Lost/dropped samples logging | |
6140 | */ | |
6141 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6142 | { | |
6143 | struct perf_output_handle handle; | |
6144 | struct perf_sample_data sample; | |
6145 | int ret; | |
6146 | ||
6147 | struct { | |
6148 | struct perf_event_header header; | |
6149 | u64 lost; | |
6150 | } lost_samples_event = { | |
6151 | .header = { | |
6152 | .type = PERF_RECORD_LOST_SAMPLES, | |
6153 | .misc = 0, | |
6154 | .size = sizeof(lost_samples_event), | |
6155 | }, | |
6156 | .lost = lost, | |
6157 | }; | |
6158 | ||
6159 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6160 | ||
6161 | ret = perf_output_begin(&handle, event, | |
6162 | lost_samples_event.header.size); | |
6163 | if (ret) | |
6164 | return; | |
6165 | ||
6166 | perf_output_put(&handle, lost_samples_event); | |
6167 | perf_event__output_id_sample(event, &handle, &sample); | |
6168 | perf_output_end(&handle); | |
6169 | } | |
6170 | ||
45ac1403 AH |
6171 | /* |
6172 | * context_switch tracking | |
6173 | */ | |
6174 | ||
6175 | struct perf_switch_event { | |
6176 | struct task_struct *task; | |
6177 | struct task_struct *next_prev; | |
6178 | ||
6179 | struct { | |
6180 | struct perf_event_header header; | |
6181 | u32 next_prev_pid; | |
6182 | u32 next_prev_tid; | |
6183 | } event_id; | |
6184 | }; | |
6185 | ||
6186 | static int perf_event_switch_match(struct perf_event *event) | |
6187 | { | |
6188 | return event->attr.context_switch; | |
6189 | } | |
6190 | ||
6191 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6192 | { | |
6193 | struct perf_switch_event *se = data; | |
6194 | struct perf_output_handle handle; | |
6195 | struct perf_sample_data sample; | |
6196 | int ret; | |
6197 | ||
6198 | if (!perf_event_switch_match(event)) | |
6199 | return; | |
6200 | ||
6201 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6202 | if (event->ctx->task) { | |
6203 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6204 | se->event_id.header.size = sizeof(se->event_id.header); | |
6205 | } else { | |
6206 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6207 | se->event_id.header.size = sizeof(se->event_id); | |
6208 | se->event_id.next_prev_pid = | |
6209 | perf_event_pid(event, se->next_prev); | |
6210 | se->event_id.next_prev_tid = | |
6211 | perf_event_tid(event, se->next_prev); | |
6212 | } | |
6213 | ||
6214 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6215 | ||
6216 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6217 | if (ret) | |
6218 | return; | |
6219 | ||
6220 | if (event->ctx->task) | |
6221 | perf_output_put(&handle, se->event_id.header); | |
6222 | else | |
6223 | perf_output_put(&handle, se->event_id); | |
6224 | ||
6225 | perf_event__output_id_sample(event, &handle, &sample); | |
6226 | ||
6227 | perf_output_end(&handle); | |
6228 | } | |
6229 | ||
6230 | static void perf_event_switch(struct task_struct *task, | |
6231 | struct task_struct *next_prev, bool sched_in) | |
6232 | { | |
6233 | struct perf_switch_event switch_event; | |
6234 | ||
6235 | /* N.B. caller checks nr_switch_events != 0 */ | |
6236 | ||
6237 | switch_event = (struct perf_switch_event){ | |
6238 | .task = task, | |
6239 | .next_prev = next_prev, | |
6240 | .event_id = { | |
6241 | .header = { | |
6242 | /* .type */ | |
6243 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6244 | /* .size */ | |
6245 | }, | |
6246 | /* .next_prev_pid */ | |
6247 | /* .next_prev_tid */ | |
6248 | }, | |
6249 | }; | |
6250 | ||
6251 | perf_event_aux(perf_event_switch_output, | |
6252 | &switch_event, | |
6253 | NULL); | |
6254 | } | |
6255 | ||
a78ac325 PZ |
6256 | /* |
6257 | * IRQ throttle logging | |
6258 | */ | |
6259 | ||
cdd6c482 | 6260 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6261 | { |
6262 | struct perf_output_handle handle; | |
c980d109 | 6263 | struct perf_sample_data sample; |
a78ac325 PZ |
6264 | int ret; |
6265 | ||
6266 | struct { | |
6267 | struct perf_event_header header; | |
6268 | u64 time; | |
cca3f454 | 6269 | u64 id; |
7f453c24 | 6270 | u64 stream_id; |
a78ac325 PZ |
6271 | } throttle_event = { |
6272 | .header = { | |
cdd6c482 | 6273 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6274 | .misc = 0, |
6275 | .size = sizeof(throttle_event), | |
6276 | }, | |
34f43927 | 6277 | .time = perf_event_clock(event), |
cdd6c482 IM |
6278 | .id = primary_event_id(event), |
6279 | .stream_id = event->id, | |
a78ac325 PZ |
6280 | }; |
6281 | ||
966ee4d6 | 6282 | if (enable) |
cdd6c482 | 6283 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6284 | |
c980d109 ACM |
6285 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6286 | ||
6287 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6288 | throttle_event.header.size); |
a78ac325 PZ |
6289 | if (ret) |
6290 | return; | |
6291 | ||
6292 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6293 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6294 | perf_output_end(&handle); |
6295 | } | |
6296 | ||
ec0d7729 AS |
6297 | static void perf_log_itrace_start(struct perf_event *event) |
6298 | { | |
6299 | struct perf_output_handle handle; | |
6300 | struct perf_sample_data sample; | |
6301 | struct perf_aux_event { | |
6302 | struct perf_event_header header; | |
6303 | u32 pid; | |
6304 | u32 tid; | |
6305 | } rec; | |
6306 | int ret; | |
6307 | ||
6308 | if (event->parent) | |
6309 | event = event->parent; | |
6310 | ||
6311 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6312 | event->hw.itrace_started) | |
6313 | return; | |
6314 | ||
ec0d7729 AS |
6315 | rec.header.type = PERF_RECORD_ITRACE_START; |
6316 | rec.header.misc = 0; | |
6317 | rec.header.size = sizeof(rec); | |
6318 | rec.pid = perf_event_pid(event, current); | |
6319 | rec.tid = perf_event_tid(event, current); | |
6320 | ||
6321 | perf_event_header__init_id(&rec.header, &sample, event); | |
6322 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6323 | ||
6324 | if (ret) | |
6325 | return; | |
6326 | ||
6327 | perf_output_put(&handle, rec); | |
6328 | perf_event__output_id_sample(event, &handle, &sample); | |
6329 | ||
6330 | perf_output_end(&handle); | |
6331 | } | |
6332 | ||
f6c7d5fe | 6333 | /* |
cdd6c482 | 6334 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6335 | */ |
6336 | ||
a8b0ca17 | 6337 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6338 | int throttle, struct perf_sample_data *data, |
6339 | struct pt_regs *regs) | |
f6c7d5fe | 6340 | { |
cdd6c482 IM |
6341 | int events = atomic_read(&event->event_limit); |
6342 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6343 | u64 seq; |
79f14641 PZ |
6344 | int ret = 0; |
6345 | ||
96398826 PZ |
6346 | /* |
6347 | * Non-sampling counters might still use the PMI to fold short | |
6348 | * hardware counters, ignore those. | |
6349 | */ | |
6350 | if (unlikely(!is_sampling_event(event))) | |
6351 | return 0; | |
6352 | ||
e050e3f0 SE |
6353 | seq = __this_cpu_read(perf_throttled_seq); |
6354 | if (seq != hwc->interrupts_seq) { | |
6355 | hwc->interrupts_seq = seq; | |
6356 | hwc->interrupts = 1; | |
6357 | } else { | |
6358 | hwc->interrupts++; | |
6359 | if (unlikely(throttle | |
6360 | && hwc->interrupts >= max_samples_per_tick)) { | |
6361 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6362 | hwc->interrupts = MAX_INTERRUPTS; |
6363 | perf_log_throttle(event, 0); | |
d84153d6 | 6364 | tick_nohz_full_kick(); |
a78ac325 PZ |
6365 | ret = 1; |
6366 | } | |
e050e3f0 | 6367 | } |
60db5e09 | 6368 | |
cdd6c482 | 6369 | if (event->attr.freq) { |
def0a9b2 | 6370 | u64 now = perf_clock(); |
abd50713 | 6371 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6372 | |
abd50713 | 6373 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6374 | |
abd50713 | 6375 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6376 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6377 | } |
6378 | ||
2023b359 PZ |
6379 | /* |
6380 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6381 | * events |
2023b359 PZ |
6382 | */ |
6383 | ||
cdd6c482 IM |
6384 | event->pending_kill = POLL_IN; |
6385 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6386 | ret = 1; |
cdd6c482 | 6387 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6388 | event->pending_disable = 1; |
6389 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6390 | } |
6391 | ||
453f19ee | 6392 | if (event->overflow_handler) |
a8b0ca17 | 6393 | event->overflow_handler(event, data, regs); |
453f19ee | 6394 | else |
a8b0ca17 | 6395 | perf_event_output(event, data, regs); |
453f19ee | 6396 | |
fed66e2c | 6397 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6398 | event->pending_wakeup = 1; |
6399 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6400 | } |
6401 | ||
79f14641 | 6402 | return ret; |
f6c7d5fe PZ |
6403 | } |
6404 | ||
a8b0ca17 | 6405 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6406 | struct perf_sample_data *data, |
6407 | struct pt_regs *regs) | |
850bc73f | 6408 | { |
a8b0ca17 | 6409 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6410 | } |
6411 | ||
15dbf27c | 6412 | /* |
cdd6c482 | 6413 | * Generic software event infrastructure |
15dbf27c PZ |
6414 | */ |
6415 | ||
b28ab83c PZ |
6416 | struct swevent_htable { |
6417 | struct swevent_hlist *swevent_hlist; | |
6418 | struct mutex hlist_mutex; | |
6419 | int hlist_refcount; | |
6420 | ||
6421 | /* Recursion avoidance in each contexts */ | |
6422 | int recursion[PERF_NR_CONTEXTS]; | |
6423 | }; | |
6424 | ||
6425 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6426 | ||
7b4b6658 | 6427 | /* |
cdd6c482 IM |
6428 | * We directly increment event->count and keep a second value in |
6429 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6430 | * is kept in the range [-sample_period, 0] so that we can use the |
6431 | * sign as trigger. | |
6432 | */ | |
6433 | ||
ab573844 | 6434 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6435 | { |
cdd6c482 | 6436 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6437 | u64 period = hwc->last_period; |
6438 | u64 nr, offset; | |
6439 | s64 old, val; | |
6440 | ||
6441 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6442 | |
6443 | again: | |
e7850595 | 6444 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6445 | if (val < 0) |
6446 | return 0; | |
15dbf27c | 6447 | |
7b4b6658 PZ |
6448 | nr = div64_u64(period + val, period); |
6449 | offset = nr * period; | |
6450 | val -= offset; | |
e7850595 | 6451 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6452 | goto again; |
15dbf27c | 6453 | |
7b4b6658 | 6454 | return nr; |
15dbf27c PZ |
6455 | } |
6456 | ||
0cff784a | 6457 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6458 | struct perf_sample_data *data, |
5622f295 | 6459 | struct pt_regs *regs) |
15dbf27c | 6460 | { |
cdd6c482 | 6461 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6462 | int throttle = 0; |
15dbf27c | 6463 | |
0cff784a PZ |
6464 | if (!overflow) |
6465 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6466 | |
7b4b6658 PZ |
6467 | if (hwc->interrupts == MAX_INTERRUPTS) |
6468 | return; | |
15dbf27c | 6469 | |
7b4b6658 | 6470 | for (; overflow; overflow--) { |
a8b0ca17 | 6471 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6472 | data, regs)) { |
7b4b6658 PZ |
6473 | /* |
6474 | * We inhibit the overflow from happening when | |
6475 | * hwc->interrupts == MAX_INTERRUPTS. | |
6476 | */ | |
6477 | break; | |
6478 | } | |
cf450a73 | 6479 | throttle = 1; |
7b4b6658 | 6480 | } |
15dbf27c PZ |
6481 | } |
6482 | ||
a4eaf7f1 | 6483 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6484 | struct perf_sample_data *data, |
5622f295 | 6485 | struct pt_regs *regs) |
7b4b6658 | 6486 | { |
cdd6c482 | 6487 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6488 | |
e7850595 | 6489 | local64_add(nr, &event->count); |
d6d020e9 | 6490 | |
0cff784a PZ |
6491 | if (!regs) |
6492 | return; | |
6493 | ||
6c7e550f | 6494 | if (!is_sampling_event(event)) |
7b4b6658 | 6495 | return; |
d6d020e9 | 6496 | |
5d81e5cf AV |
6497 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6498 | data->period = nr; | |
6499 | return perf_swevent_overflow(event, 1, data, regs); | |
6500 | } else | |
6501 | data->period = event->hw.last_period; | |
6502 | ||
0cff784a | 6503 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6504 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6505 | |
e7850595 | 6506 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6507 | return; |
df1a132b | 6508 | |
a8b0ca17 | 6509 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6510 | } |
6511 | ||
f5ffe02e FW |
6512 | static int perf_exclude_event(struct perf_event *event, |
6513 | struct pt_regs *regs) | |
6514 | { | |
a4eaf7f1 | 6515 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6516 | return 1; |
a4eaf7f1 | 6517 | |
f5ffe02e FW |
6518 | if (regs) { |
6519 | if (event->attr.exclude_user && user_mode(regs)) | |
6520 | return 1; | |
6521 | ||
6522 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6523 | return 1; | |
6524 | } | |
6525 | ||
6526 | return 0; | |
6527 | } | |
6528 | ||
cdd6c482 | 6529 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6530 | enum perf_type_id type, |
6fb2915d LZ |
6531 | u32 event_id, |
6532 | struct perf_sample_data *data, | |
6533 | struct pt_regs *regs) | |
15dbf27c | 6534 | { |
cdd6c482 | 6535 | if (event->attr.type != type) |
a21ca2ca | 6536 | return 0; |
f5ffe02e | 6537 | |
cdd6c482 | 6538 | if (event->attr.config != event_id) |
15dbf27c PZ |
6539 | return 0; |
6540 | ||
f5ffe02e FW |
6541 | if (perf_exclude_event(event, regs)) |
6542 | return 0; | |
15dbf27c PZ |
6543 | |
6544 | return 1; | |
6545 | } | |
6546 | ||
76e1d904 FW |
6547 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6548 | { | |
6549 | u64 val = event_id | (type << 32); | |
6550 | ||
6551 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6552 | } | |
6553 | ||
49f135ed FW |
6554 | static inline struct hlist_head * |
6555 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6556 | { |
49f135ed FW |
6557 | u64 hash = swevent_hash(type, event_id); |
6558 | ||
6559 | return &hlist->heads[hash]; | |
6560 | } | |
76e1d904 | 6561 | |
49f135ed FW |
6562 | /* For the read side: events when they trigger */ |
6563 | static inline struct hlist_head * | |
b28ab83c | 6564 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6565 | { |
6566 | struct swevent_hlist *hlist; | |
76e1d904 | 6567 | |
b28ab83c | 6568 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6569 | if (!hlist) |
6570 | return NULL; | |
6571 | ||
49f135ed FW |
6572 | return __find_swevent_head(hlist, type, event_id); |
6573 | } | |
6574 | ||
6575 | /* For the event head insertion and removal in the hlist */ | |
6576 | static inline struct hlist_head * | |
b28ab83c | 6577 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6578 | { |
6579 | struct swevent_hlist *hlist; | |
6580 | u32 event_id = event->attr.config; | |
6581 | u64 type = event->attr.type; | |
6582 | ||
6583 | /* | |
6584 | * Event scheduling is always serialized against hlist allocation | |
6585 | * and release. Which makes the protected version suitable here. | |
6586 | * The context lock guarantees that. | |
6587 | */ | |
b28ab83c | 6588 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6589 | lockdep_is_held(&event->ctx->lock)); |
6590 | if (!hlist) | |
6591 | return NULL; | |
6592 | ||
6593 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6594 | } |
6595 | ||
6596 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6597 | u64 nr, |
76e1d904 FW |
6598 | struct perf_sample_data *data, |
6599 | struct pt_regs *regs) | |
15dbf27c | 6600 | { |
4a32fea9 | 6601 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6602 | struct perf_event *event; |
76e1d904 | 6603 | struct hlist_head *head; |
15dbf27c | 6604 | |
76e1d904 | 6605 | rcu_read_lock(); |
b28ab83c | 6606 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6607 | if (!head) |
6608 | goto end; | |
6609 | ||
b67bfe0d | 6610 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6611 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6612 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6613 | } |
76e1d904 FW |
6614 | end: |
6615 | rcu_read_unlock(); | |
15dbf27c PZ |
6616 | } |
6617 | ||
86038c5e PZI |
6618 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6619 | ||
4ed7c92d | 6620 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6621 | { |
4a32fea9 | 6622 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6623 | |
b28ab83c | 6624 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6625 | } |
645e8cc0 | 6626 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6627 | |
fa9f90be | 6628 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6629 | { |
4a32fea9 | 6630 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6631 | |
b28ab83c | 6632 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6633 | } |
15dbf27c | 6634 | |
86038c5e | 6635 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6636 | { |
a4234bfc | 6637 | struct perf_sample_data data; |
4ed7c92d | 6638 | |
86038c5e | 6639 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6640 | return; |
a4234bfc | 6641 | |
fd0d000b | 6642 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6643 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6644 | } |
6645 | ||
6646 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6647 | { | |
6648 | int rctx; | |
6649 | ||
6650 | preempt_disable_notrace(); | |
6651 | rctx = perf_swevent_get_recursion_context(); | |
6652 | if (unlikely(rctx < 0)) | |
6653 | goto fail; | |
6654 | ||
6655 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6656 | |
6657 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6658 | fail: |
1c024eca | 6659 | preempt_enable_notrace(); |
b8e83514 PZ |
6660 | } |
6661 | ||
cdd6c482 | 6662 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6663 | { |
15dbf27c PZ |
6664 | } |
6665 | ||
a4eaf7f1 | 6666 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6667 | { |
4a32fea9 | 6668 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6669 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6670 | struct hlist_head *head; |
6671 | ||
6c7e550f | 6672 | if (is_sampling_event(event)) { |
7b4b6658 | 6673 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6674 | perf_swevent_set_period(event); |
7b4b6658 | 6675 | } |
76e1d904 | 6676 | |
a4eaf7f1 PZ |
6677 | hwc->state = !(flags & PERF_EF_START); |
6678 | ||
b28ab83c | 6679 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6680 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6681 | return -EINVAL; |
6682 | ||
6683 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6684 | perf_event_update_userpage(event); |
76e1d904 | 6685 | |
15dbf27c PZ |
6686 | return 0; |
6687 | } | |
6688 | ||
a4eaf7f1 | 6689 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6690 | { |
76e1d904 | 6691 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6692 | } |
6693 | ||
a4eaf7f1 | 6694 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6695 | { |
a4eaf7f1 | 6696 | event->hw.state = 0; |
d6d020e9 | 6697 | } |
aa9c4c0f | 6698 | |
a4eaf7f1 | 6699 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6700 | { |
a4eaf7f1 | 6701 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6702 | } |
6703 | ||
49f135ed FW |
6704 | /* Deref the hlist from the update side */ |
6705 | static inline struct swevent_hlist * | |
b28ab83c | 6706 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6707 | { |
b28ab83c PZ |
6708 | return rcu_dereference_protected(swhash->swevent_hlist, |
6709 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6710 | } |
6711 | ||
b28ab83c | 6712 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6713 | { |
b28ab83c | 6714 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6715 | |
49f135ed | 6716 | if (!hlist) |
76e1d904 FW |
6717 | return; |
6718 | ||
70691d4a | 6719 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6720 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6721 | } |
6722 | ||
6723 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6724 | { | |
b28ab83c | 6725 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6726 | |
b28ab83c | 6727 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6728 | |
b28ab83c PZ |
6729 | if (!--swhash->hlist_refcount) |
6730 | swevent_hlist_release(swhash); | |
76e1d904 | 6731 | |
b28ab83c | 6732 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6733 | } |
6734 | ||
6735 | static void swevent_hlist_put(struct perf_event *event) | |
6736 | { | |
6737 | int cpu; | |
6738 | ||
76e1d904 FW |
6739 | for_each_possible_cpu(cpu) |
6740 | swevent_hlist_put_cpu(event, cpu); | |
6741 | } | |
6742 | ||
6743 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6744 | { | |
b28ab83c | 6745 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6746 | int err = 0; |
6747 | ||
b28ab83c | 6748 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6749 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6750 | struct swevent_hlist *hlist; |
6751 | ||
6752 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6753 | if (!hlist) { | |
6754 | err = -ENOMEM; | |
6755 | goto exit; | |
6756 | } | |
b28ab83c | 6757 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6758 | } |
b28ab83c | 6759 | swhash->hlist_refcount++; |
9ed6060d | 6760 | exit: |
b28ab83c | 6761 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6762 | |
6763 | return err; | |
6764 | } | |
6765 | ||
6766 | static int swevent_hlist_get(struct perf_event *event) | |
6767 | { | |
6768 | int err; | |
6769 | int cpu, failed_cpu; | |
6770 | ||
76e1d904 FW |
6771 | get_online_cpus(); |
6772 | for_each_possible_cpu(cpu) { | |
6773 | err = swevent_hlist_get_cpu(event, cpu); | |
6774 | if (err) { | |
6775 | failed_cpu = cpu; | |
6776 | goto fail; | |
6777 | } | |
6778 | } | |
6779 | put_online_cpus(); | |
6780 | ||
6781 | return 0; | |
9ed6060d | 6782 | fail: |
76e1d904 FW |
6783 | for_each_possible_cpu(cpu) { |
6784 | if (cpu == failed_cpu) | |
6785 | break; | |
6786 | swevent_hlist_put_cpu(event, cpu); | |
6787 | } | |
6788 | ||
6789 | put_online_cpus(); | |
6790 | return err; | |
6791 | } | |
6792 | ||
c5905afb | 6793 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6794 | |
b0a873eb PZ |
6795 | static void sw_perf_event_destroy(struct perf_event *event) |
6796 | { | |
6797 | u64 event_id = event->attr.config; | |
95476b64 | 6798 | |
b0a873eb PZ |
6799 | WARN_ON(event->parent); |
6800 | ||
c5905afb | 6801 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6802 | swevent_hlist_put(event); |
6803 | } | |
6804 | ||
6805 | static int perf_swevent_init(struct perf_event *event) | |
6806 | { | |
8176cced | 6807 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6808 | |
6809 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6810 | return -ENOENT; | |
6811 | ||
2481c5fa SE |
6812 | /* |
6813 | * no branch sampling for software events | |
6814 | */ | |
6815 | if (has_branch_stack(event)) | |
6816 | return -EOPNOTSUPP; | |
6817 | ||
b0a873eb PZ |
6818 | switch (event_id) { |
6819 | case PERF_COUNT_SW_CPU_CLOCK: | |
6820 | case PERF_COUNT_SW_TASK_CLOCK: | |
6821 | return -ENOENT; | |
6822 | ||
6823 | default: | |
6824 | break; | |
6825 | } | |
6826 | ||
ce677831 | 6827 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6828 | return -ENOENT; |
6829 | ||
6830 | if (!event->parent) { | |
6831 | int err; | |
6832 | ||
6833 | err = swevent_hlist_get(event); | |
6834 | if (err) | |
6835 | return err; | |
6836 | ||
c5905afb | 6837 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6838 | event->destroy = sw_perf_event_destroy; |
6839 | } | |
6840 | ||
6841 | return 0; | |
6842 | } | |
6843 | ||
6844 | static struct pmu perf_swevent = { | |
89a1e187 | 6845 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6846 | |
34f43927 PZ |
6847 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6848 | ||
b0a873eb | 6849 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6850 | .add = perf_swevent_add, |
6851 | .del = perf_swevent_del, | |
6852 | .start = perf_swevent_start, | |
6853 | .stop = perf_swevent_stop, | |
1c024eca | 6854 | .read = perf_swevent_read, |
1c024eca PZ |
6855 | }; |
6856 | ||
b0a873eb PZ |
6857 | #ifdef CONFIG_EVENT_TRACING |
6858 | ||
1c024eca PZ |
6859 | static int perf_tp_filter_match(struct perf_event *event, |
6860 | struct perf_sample_data *data) | |
6861 | { | |
6862 | void *record = data->raw->data; | |
6863 | ||
b71b437e PZ |
6864 | /* only top level events have filters set */ |
6865 | if (event->parent) | |
6866 | event = event->parent; | |
6867 | ||
1c024eca PZ |
6868 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6869 | return 1; | |
6870 | return 0; | |
6871 | } | |
6872 | ||
6873 | static int perf_tp_event_match(struct perf_event *event, | |
6874 | struct perf_sample_data *data, | |
6875 | struct pt_regs *regs) | |
6876 | { | |
a0f7d0f7 FW |
6877 | if (event->hw.state & PERF_HES_STOPPED) |
6878 | return 0; | |
580d607c PZ |
6879 | /* |
6880 | * All tracepoints are from kernel-space. | |
6881 | */ | |
6882 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6883 | return 0; |
6884 | ||
6885 | if (!perf_tp_filter_match(event, data)) | |
6886 | return 0; | |
6887 | ||
6888 | return 1; | |
6889 | } | |
6890 | ||
6891 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6892 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6893 | struct task_struct *task) | |
95476b64 FW |
6894 | { |
6895 | struct perf_sample_data data; | |
1c024eca | 6896 | struct perf_event *event; |
1c024eca | 6897 | |
95476b64 FW |
6898 | struct perf_raw_record raw = { |
6899 | .size = entry_size, | |
6900 | .data = record, | |
6901 | }; | |
6902 | ||
fd0d000b | 6903 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6904 | data.raw = &raw; |
6905 | ||
b67bfe0d | 6906 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6907 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6908 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6909 | } |
ecc55f84 | 6910 | |
e6dab5ff AV |
6911 | /* |
6912 | * If we got specified a target task, also iterate its context and | |
6913 | * deliver this event there too. | |
6914 | */ | |
6915 | if (task && task != current) { | |
6916 | struct perf_event_context *ctx; | |
6917 | struct trace_entry *entry = record; | |
6918 | ||
6919 | rcu_read_lock(); | |
6920 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6921 | if (!ctx) | |
6922 | goto unlock; | |
6923 | ||
6924 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6925 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6926 | continue; | |
6927 | if (event->attr.config != entry->type) | |
6928 | continue; | |
6929 | if (perf_tp_event_match(event, &data, regs)) | |
6930 | perf_swevent_event(event, count, &data, regs); | |
6931 | } | |
6932 | unlock: | |
6933 | rcu_read_unlock(); | |
6934 | } | |
6935 | ||
ecc55f84 | 6936 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6937 | } |
6938 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6939 | ||
cdd6c482 | 6940 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6941 | { |
1c024eca | 6942 | perf_trace_destroy(event); |
e077df4f PZ |
6943 | } |
6944 | ||
b0a873eb | 6945 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6946 | { |
76e1d904 FW |
6947 | int err; |
6948 | ||
b0a873eb PZ |
6949 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6950 | return -ENOENT; | |
6951 | ||
2481c5fa SE |
6952 | /* |
6953 | * no branch sampling for tracepoint events | |
6954 | */ | |
6955 | if (has_branch_stack(event)) | |
6956 | return -EOPNOTSUPP; | |
6957 | ||
1c024eca PZ |
6958 | err = perf_trace_init(event); |
6959 | if (err) | |
b0a873eb | 6960 | return err; |
e077df4f | 6961 | |
cdd6c482 | 6962 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6963 | |
b0a873eb PZ |
6964 | return 0; |
6965 | } | |
6966 | ||
6967 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6968 | .task_ctx_nr = perf_sw_context, |
6969 | ||
b0a873eb | 6970 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6971 | .add = perf_trace_add, |
6972 | .del = perf_trace_del, | |
6973 | .start = perf_swevent_start, | |
6974 | .stop = perf_swevent_stop, | |
b0a873eb | 6975 | .read = perf_swevent_read, |
b0a873eb PZ |
6976 | }; |
6977 | ||
6978 | static inline void perf_tp_register(void) | |
6979 | { | |
2e80a82a | 6980 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6981 | } |
6fb2915d LZ |
6982 | |
6983 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6984 | { | |
6985 | char *filter_str; | |
6986 | int ret; | |
6987 | ||
6988 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6989 | return -EINVAL; | |
6990 | ||
6991 | filter_str = strndup_user(arg, PAGE_SIZE); | |
6992 | if (IS_ERR(filter_str)) | |
6993 | return PTR_ERR(filter_str); | |
6994 | ||
6995 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
6996 | ||
6997 | kfree(filter_str); | |
6998 | return ret; | |
6999 | } | |
7000 | ||
7001 | static void perf_event_free_filter(struct perf_event *event) | |
7002 | { | |
7003 | ftrace_profile_free_filter(event); | |
7004 | } | |
7005 | ||
2541517c AS |
7006 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7007 | { | |
7008 | struct bpf_prog *prog; | |
7009 | ||
7010 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7011 | return -EINVAL; | |
7012 | ||
7013 | if (event->tp_event->prog) | |
7014 | return -EEXIST; | |
7015 | ||
04a22fae WN |
7016 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7017 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7018 | return -EINVAL; |
7019 | ||
7020 | prog = bpf_prog_get(prog_fd); | |
7021 | if (IS_ERR(prog)) | |
7022 | return PTR_ERR(prog); | |
7023 | ||
6c373ca8 | 7024 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7025 | /* valid fd, but invalid bpf program type */ |
7026 | bpf_prog_put(prog); | |
7027 | return -EINVAL; | |
7028 | } | |
7029 | ||
7030 | event->tp_event->prog = prog; | |
7031 | ||
7032 | return 0; | |
7033 | } | |
7034 | ||
7035 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7036 | { | |
7037 | struct bpf_prog *prog; | |
7038 | ||
7039 | if (!event->tp_event) | |
7040 | return; | |
7041 | ||
7042 | prog = event->tp_event->prog; | |
7043 | if (prog) { | |
7044 | event->tp_event->prog = NULL; | |
7045 | bpf_prog_put(prog); | |
7046 | } | |
7047 | } | |
7048 | ||
e077df4f | 7049 | #else |
6fb2915d | 7050 | |
b0a873eb | 7051 | static inline void perf_tp_register(void) |
e077df4f | 7052 | { |
e077df4f | 7053 | } |
6fb2915d LZ |
7054 | |
7055 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7056 | { | |
7057 | return -ENOENT; | |
7058 | } | |
7059 | ||
7060 | static void perf_event_free_filter(struct perf_event *event) | |
7061 | { | |
7062 | } | |
7063 | ||
2541517c AS |
7064 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7065 | { | |
7066 | return -ENOENT; | |
7067 | } | |
7068 | ||
7069 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7070 | { | |
7071 | } | |
07b139c8 | 7072 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7073 | |
24f1e32c | 7074 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7075 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7076 | { |
f5ffe02e FW |
7077 | struct perf_sample_data sample; |
7078 | struct pt_regs *regs = data; | |
7079 | ||
fd0d000b | 7080 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7081 | |
a4eaf7f1 | 7082 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7083 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7084 | } |
7085 | #endif | |
7086 | ||
b0a873eb PZ |
7087 | /* |
7088 | * hrtimer based swevent callback | |
7089 | */ | |
f29ac756 | 7090 | |
b0a873eb | 7091 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7092 | { |
b0a873eb PZ |
7093 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7094 | struct perf_sample_data data; | |
7095 | struct pt_regs *regs; | |
7096 | struct perf_event *event; | |
7097 | u64 period; | |
f29ac756 | 7098 | |
b0a873eb | 7099 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7100 | |
7101 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7102 | return HRTIMER_NORESTART; | |
7103 | ||
b0a873eb | 7104 | event->pmu->read(event); |
f344011c | 7105 | |
fd0d000b | 7106 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7107 | regs = get_irq_regs(); |
7108 | ||
7109 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7110 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7111 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7112 | ret = HRTIMER_NORESTART; |
7113 | } | |
24f1e32c | 7114 | |
b0a873eb PZ |
7115 | period = max_t(u64, 10000, event->hw.sample_period); |
7116 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7117 | |
b0a873eb | 7118 | return ret; |
f29ac756 PZ |
7119 | } |
7120 | ||
b0a873eb | 7121 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7122 | { |
b0a873eb | 7123 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7124 | s64 period; |
7125 | ||
7126 | if (!is_sampling_event(event)) | |
7127 | return; | |
f5ffe02e | 7128 | |
5d508e82 FBH |
7129 | period = local64_read(&hwc->period_left); |
7130 | if (period) { | |
7131 | if (period < 0) | |
7132 | period = 10000; | |
fa407f35 | 7133 | |
5d508e82 FBH |
7134 | local64_set(&hwc->period_left, 0); |
7135 | } else { | |
7136 | period = max_t(u64, 10000, hwc->sample_period); | |
7137 | } | |
3497d206 TG |
7138 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7139 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7140 | } |
b0a873eb PZ |
7141 | |
7142 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7143 | { |
b0a873eb PZ |
7144 | struct hw_perf_event *hwc = &event->hw; |
7145 | ||
6c7e550f | 7146 | if (is_sampling_event(event)) { |
b0a873eb | 7147 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7148 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7149 | |
7150 | hrtimer_cancel(&hwc->hrtimer); | |
7151 | } | |
24f1e32c FW |
7152 | } |
7153 | ||
ba3dd36c PZ |
7154 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7155 | { | |
7156 | struct hw_perf_event *hwc = &event->hw; | |
7157 | ||
7158 | if (!is_sampling_event(event)) | |
7159 | return; | |
7160 | ||
7161 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7162 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7163 | ||
7164 | /* | |
7165 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7166 | * mapping and avoid the whole period adjust feedback stuff. | |
7167 | */ | |
7168 | if (event->attr.freq) { | |
7169 | long freq = event->attr.sample_freq; | |
7170 | ||
7171 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7172 | hwc->sample_period = event->attr.sample_period; | |
7173 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7174 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7175 | event->attr.freq = 0; |
7176 | } | |
7177 | } | |
7178 | ||
b0a873eb PZ |
7179 | /* |
7180 | * Software event: cpu wall time clock | |
7181 | */ | |
7182 | ||
7183 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7184 | { |
b0a873eb PZ |
7185 | s64 prev; |
7186 | u64 now; | |
7187 | ||
a4eaf7f1 | 7188 | now = local_clock(); |
b0a873eb PZ |
7189 | prev = local64_xchg(&event->hw.prev_count, now); |
7190 | local64_add(now - prev, &event->count); | |
24f1e32c | 7191 | } |
24f1e32c | 7192 | |
a4eaf7f1 | 7193 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7194 | { |
a4eaf7f1 | 7195 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7196 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7197 | } |
7198 | ||
a4eaf7f1 | 7199 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7200 | { |
b0a873eb PZ |
7201 | perf_swevent_cancel_hrtimer(event); |
7202 | cpu_clock_event_update(event); | |
7203 | } | |
f29ac756 | 7204 | |
a4eaf7f1 PZ |
7205 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7206 | { | |
7207 | if (flags & PERF_EF_START) | |
7208 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7209 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7210 | |
7211 | return 0; | |
7212 | } | |
7213 | ||
7214 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7215 | { | |
7216 | cpu_clock_event_stop(event, flags); | |
7217 | } | |
7218 | ||
b0a873eb PZ |
7219 | static void cpu_clock_event_read(struct perf_event *event) |
7220 | { | |
7221 | cpu_clock_event_update(event); | |
7222 | } | |
f344011c | 7223 | |
b0a873eb PZ |
7224 | static int cpu_clock_event_init(struct perf_event *event) |
7225 | { | |
7226 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7227 | return -ENOENT; | |
7228 | ||
7229 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7230 | return -ENOENT; | |
7231 | ||
2481c5fa SE |
7232 | /* |
7233 | * no branch sampling for software events | |
7234 | */ | |
7235 | if (has_branch_stack(event)) | |
7236 | return -EOPNOTSUPP; | |
7237 | ||
ba3dd36c PZ |
7238 | perf_swevent_init_hrtimer(event); |
7239 | ||
b0a873eb | 7240 | return 0; |
f29ac756 PZ |
7241 | } |
7242 | ||
b0a873eb | 7243 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7244 | .task_ctx_nr = perf_sw_context, |
7245 | ||
34f43927 PZ |
7246 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7247 | ||
b0a873eb | 7248 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7249 | .add = cpu_clock_event_add, |
7250 | .del = cpu_clock_event_del, | |
7251 | .start = cpu_clock_event_start, | |
7252 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7253 | .read = cpu_clock_event_read, |
7254 | }; | |
7255 | ||
7256 | /* | |
7257 | * Software event: task time clock | |
7258 | */ | |
7259 | ||
7260 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7261 | { |
b0a873eb PZ |
7262 | u64 prev; |
7263 | s64 delta; | |
5c92d124 | 7264 | |
b0a873eb PZ |
7265 | prev = local64_xchg(&event->hw.prev_count, now); |
7266 | delta = now - prev; | |
7267 | local64_add(delta, &event->count); | |
7268 | } | |
5c92d124 | 7269 | |
a4eaf7f1 | 7270 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7271 | { |
a4eaf7f1 | 7272 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7273 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7274 | } |
7275 | ||
a4eaf7f1 | 7276 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7277 | { |
7278 | perf_swevent_cancel_hrtimer(event); | |
7279 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7280 | } |
7281 | ||
7282 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7283 | { | |
7284 | if (flags & PERF_EF_START) | |
7285 | task_clock_event_start(event, flags); | |
6a694a60 | 7286 | perf_event_update_userpage(event); |
b0a873eb | 7287 | |
a4eaf7f1 PZ |
7288 | return 0; |
7289 | } | |
7290 | ||
7291 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7292 | { | |
7293 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7294 | } |
7295 | ||
7296 | static void task_clock_event_read(struct perf_event *event) | |
7297 | { | |
768a06e2 PZ |
7298 | u64 now = perf_clock(); |
7299 | u64 delta = now - event->ctx->timestamp; | |
7300 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7301 | |
7302 | task_clock_event_update(event, time); | |
7303 | } | |
7304 | ||
7305 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7306 | { |
b0a873eb PZ |
7307 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7308 | return -ENOENT; | |
7309 | ||
7310 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7311 | return -ENOENT; | |
7312 | ||
2481c5fa SE |
7313 | /* |
7314 | * no branch sampling for software events | |
7315 | */ | |
7316 | if (has_branch_stack(event)) | |
7317 | return -EOPNOTSUPP; | |
7318 | ||
ba3dd36c PZ |
7319 | perf_swevent_init_hrtimer(event); |
7320 | ||
b0a873eb | 7321 | return 0; |
6fb2915d LZ |
7322 | } |
7323 | ||
b0a873eb | 7324 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7325 | .task_ctx_nr = perf_sw_context, |
7326 | ||
34f43927 PZ |
7327 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7328 | ||
b0a873eb | 7329 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7330 | .add = task_clock_event_add, |
7331 | .del = task_clock_event_del, | |
7332 | .start = task_clock_event_start, | |
7333 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7334 | .read = task_clock_event_read, |
7335 | }; | |
6fb2915d | 7336 | |
ad5133b7 | 7337 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7338 | { |
e077df4f | 7339 | } |
6fb2915d | 7340 | |
fbbe0701 SB |
7341 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7342 | { | |
7343 | } | |
7344 | ||
ad5133b7 | 7345 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7346 | { |
ad5133b7 | 7347 | return 0; |
6fb2915d LZ |
7348 | } |
7349 | ||
18ab2cd3 | 7350 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7351 | |
7352 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7353 | { |
fbbe0701 SB |
7354 | __this_cpu_write(nop_txn_flags, flags); |
7355 | ||
7356 | if (flags & ~PERF_PMU_TXN_ADD) | |
7357 | return; | |
7358 | ||
ad5133b7 | 7359 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7360 | } |
7361 | ||
ad5133b7 PZ |
7362 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7363 | { | |
fbbe0701 SB |
7364 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7365 | ||
7366 | __this_cpu_write(nop_txn_flags, 0); | |
7367 | ||
7368 | if (flags & ~PERF_PMU_TXN_ADD) | |
7369 | return 0; | |
7370 | ||
ad5133b7 PZ |
7371 | perf_pmu_enable(pmu); |
7372 | return 0; | |
7373 | } | |
e077df4f | 7374 | |
ad5133b7 | 7375 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7376 | { |
fbbe0701 SB |
7377 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7378 | ||
7379 | __this_cpu_write(nop_txn_flags, 0); | |
7380 | ||
7381 | if (flags & ~PERF_PMU_TXN_ADD) | |
7382 | return; | |
7383 | ||
ad5133b7 | 7384 | perf_pmu_enable(pmu); |
24f1e32c FW |
7385 | } |
7386 | ||
35edc2a5 PZ |
7387 | static int perf_event_idx_default(struct perf_event *event) |
7388 | { | |
c719f560 | 7389 | return 0; |
35edc2a5 PZ |
7390 | } |
7391 | ||
8dc85d54 PZ |
7392 | /* |
7393 | * Ensures all contexts with the same task_ctx_nr have the same | |
7394 | * pmu_cpu_context too. | |
7395 | */ | |
9e317041 | 7396 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7397 | { |
8dc85d54 | 7398 | struct pmu *pmu; |
b326e956 | 7399 | |
8dc85d54 PZ |
7400 | if (ctxn < 0) |
7401 | return NULL; | |
24f1e32c | 7402 | |
8dc85d54 PZ |
7403 | list_for_each_entry(pmu, &pmus, entry) { |
7404 | if (pmu->task_ctx_nr == ctxn) | |
7405 | return pmu->pmu_cpu_context; | |
7406 | } | |
24f1e32c | 7407 | |
8dc85d54 | 7408 | return NULL; |
24f1e32c FW |
7409 | } |
7410 | ||
51676957 | 7411 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7412 | { |
51676957 PZ |
7413 | int cpu; |
7414 | ||
7415 | for_each_possible_cpu(cpu) { | |
7416 | struct perf_cpu_context *cpuctx; | |
7417 | ||
7418 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7419 | ||
3f1f3320 PZ |
7420 | if (cpuctx->unique_pmu == old_pmu) |
7421 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7422 | } |
7423 | } | |
7424 | ||
7425 | static void free_pmu_context(struct pmu *pmu) | |
7426 | { | |
7427 | struct pmu *i; | |
f5ffe02e | 7428 | |
8dc85d54 | 7429 | mutex_lock(&pmus_lock); |
0475f9ea | 7430 | /* |
8dc85d54 | 7431 | * Like a real lame refcount. |
0475f9ea | 7432 | */ |
51676957 PZ |
7433 | list_for_each_entry(i, &pmus, entry) { |
7434 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7435 | update_pmu_context(i, pmu); | |
8dc85d54 | 7436 | goto out; |
51676957 | 7437 | } |
8dc85d54 | 7438 | } |
d6d020e9 | 7439 | |
51676957 | 7440 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7441 | out: |
7442 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7443 | } |
2e80a82a | 7444 | static struct idr pmu_idr; |
d6d020e9 | 7445 | |
abe43400 PZ |
7446 | static ssize_t |
7447 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7448 | { | |
7449 | struct pmu *pmu = dev_get_drvdata(dev); | |
7450 | ||
7451 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7452 | } | |
90826ca7 | 7453 | static DEVICE_ATTR_RO(type); |
abe43400 | 7454 | |
62b85639 SE |
7455 | static ssize_t |
7456 | perf_event_mux_interval_ms_show(struct device *dev, | |
7457 | struct device_attribute *attr, | |
7458 | char *page) | |
7459 | { | |
7460 | struct pmu *pmu = dev_get_drvdata(dev); | |
7461 | ||
7462 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7463 | } | |
7464 | ||
272325c4 PZ |
7465 | static DEFINE_MUTEX(mux_interval_mutex); |
7466 | ||
62b85639 SE |
7467 | static ssize_t |
7468 | perf_event_mux_interval_ms_store(struct device *dev, | |
7469 | struct device_attribute *attr, | |
7470 | const char *buf, size_t count) | |
7471 | { | |
7472 | struct pmu *pmu = dev_get_drvdata(dev); | |
7473 | int timer, cpu, ret; | |
7474 | ||
7475 | ret = kstrtoint(buf, 0, &timer); | |
7476 | if (ret) | |
7477 | return ret; | |
7478 | ||
7479 | if (timer < 1) | |
7480 | return -EINVAL; | |
7481 | ||
7482 | /* same value, noting to do */ | |
7483 | if (timer == pmu->hrtimer_interval_ms) | |
7484 | return count; | |
7485 | ||
272325c4 | 7486 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7487 | pmu->hrtimer_interval_ms = timer; |
7488 | ||
7489 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7490 | get_online_cpus(); |
7491 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7492 | struct perf_cpu_context *cpuctx; |
7493 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7494 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7495 | ||
272325c4 PZ |
7496 | cpu_function_call(cpu, |
7497 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7498 | } |
272325c4 PZ |
7499 | put_online_cpus(); |
7500 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7501 | |
7502 | return count; | |
7503 | } | |
90826ca7 | 7504 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7505 | |
90826ca7 GKH |
7506 | static struct attribute *pmu_dev_attrs[] = { |
7507 | &dev_attr_type.attr, | |
7508 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7509 | NULL, | |
abe43400 | 7510 | }; |
90826ca7 | 7511 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7512 | |
7513 | static int pmu_bus_running; | |
7514 | static struct bus_type pmu_bus = { | |
7515 | .name = "event_source", | |
90826ca7 | 7516 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7517 | }; |
7518 | ||
7519 | static void pmu_dev_release(struct device *dev) | |
7520 | { | |
7521 | kfree(dev); | |
7522 | } | |
7523 | ||
7524 | static int pmu_dev_alloc(struct pmu *pmu) | |
7525 | { | |
7526 | int ret = -ENOMEM; | |
7527 | ||
7528 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7529 | if (!pmu->dev) | |
7530 | goto out; | |
7531 | ||
0c9d42ed | 7532 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7533 | device_initialize(pmu->dev); |
7534 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7535 | if (ret) | |
7536 | goto free_dev; | |
7537 | ||
7538 | dev_set_drvdata(pmu->dev, pmu); | |
7539 | pmu->dev->bus = &pmu_bus; | |
7540 | pmu->dev->release = pmu_dev_release; | |
7541 | ret = device_add(pmu->dev); | |
7542 | if (ret) | |
7543 | goto free_dev; | |
7544 | ||
7545 | out: | |
7546 | return ret; | |
7547 | ||
7548 | free_dev: | |
7549 | put_device(pmu->dev); | |
7550 | goto out; | |
7551 | } | |
7552 | ||
547e9fd7 | 7553 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7554 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7555 | |
03d8e80b | 7556 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7557 | { |
108b02cf | 7558 | int cpu, ret; |
24f1e32c | 7559 | |
b0a873eb | 7560 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7561 | ret = -ENOMEM; |
7562 | pmu->pmu_disable_count = alloc_percpu(int); | |
7563 | if (!pmu->pmu_disable_count) | |
7564 | goto unlock; | |
f29ac756 | 7565 | |
2e80a82a PZ |
7566 | pmu->type = -1; |
7567 | if (!name) | |
7568 | goto skip_type; | |
7569 | pmu->name = name; | |
7570 | ||
7571 | if (type < 0) { | |
0e9c3be2 TH |
7572 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7573 | if (type < 0) { | |
7574 | ret = type; | |
2e80a82a PZ |
7575 | goto free_pdc; |
7576 | } | |
7577 | } | |
7578 | pmu->type = type; | |
7579 | ||
abe43400 PZ |
7580 | if (pmu_bus_running) { |
7581 | ret = pmu_dev_alloc(pmu); | |
7582 | if (ret) | |
7583 | goto free_idr; | |
7584 | } | |
7585 | ||
2e80a82a | 7586 | skip_type: |
8dc85d54 PZ |
7587 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7588 | if (pmu->pmu_cpu_context) | |
7589 | goto got_cpu_context; | |
f29ac756 | 7590 | |
c4814202 | 7591 | ret = -ENOMEM; |
108b02cf PZ |
7592 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7593 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7594 | goto free_dev; |
f344011c | 7595 | |
108b02cf PZ |
7596 | for_each_possible_cpu(cpu) { |
7597 | struct perf_cpu_context *cpuctx; | |
7598 | ||
7599 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7600 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7601 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7602 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7603 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7604 | |
272325c4 | 7605 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7606 | |
3f1f3320 | 7607 | cpuctx->unique_pmu = pmu; |
108b02cf | 7608 | } |
76e1d904 | 7609 | |
8dc85d54 | 7610 | got_cpu_context: |
ad5133b7 PZ |
7611 | if (!pmu->start_txn) { |
7612 | if (pmu->pmu_enable) { | |
7613 | /* | |
7614 | * If we have pmu_enable/pmu_disable calls, install | |
7615 | * transaction stubs that use that to try and batch | |
7616 | * hardware accesses. | |
7617 | */ | |
7618 | pmu->start_txn = perf_pmu_start_txn; | |
7619 | pmu->commit_txn = perf_pmu_commit_txn; | |
7620 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7621 | } else { | |
fbbe0701 | 7622 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7623 | pmu->commit_txn = perf_pmu_nop_int; |
7624 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7625 | } |
5c92d124 | 7626 | } |
15dbf27c | 7627 | |
ad5133b7 PZ |
7628 | if (!pmu->pmu_enable) { |
7629 | pmu->pmu_enable = perf_pmu_nop_void; | |
7630 | pmu->pmu_disable = perf_pmu_nop_void; | |
7631 | } | |
7632 | ||
35edc2a5 PZ |
7633 | if (!pmu->event_idx) |
7634 | pmu->event_idx = perf_event_idx_default; | |
7635 | ||
b0a873eb | 7636 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7637 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7638 | ret = 0; |
7639 | unlock: | |
b0a873eb PZ |
7640 | mutex_unlock(&pmus_lock); |
7641 | ||
33696fc0 | 7642 | return ret; |
108b02cf | 7643 | |
abe43400 PZ |
7644 | free_dev: |
7645 | device_del(pmu->dev); | |
7646 | put_device(pmu->dev); | |
7647 | ||
2e80a82a PZ |
7648 | free_idr: |
7649 | if (pmu->type >= PERF_TYPE_MAX) | |
7650 | idr_remove(&pmu_idr, pmu->type); | |
7651 | ||
108b02cf PZ |
7652 | free_pdc: |
7653 | free_percpu(pmu->pmu_disable_count); | |
7654 | goto unlock; | |
f29ac756 | 7655 | } |
c464c76e | 7656 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7657 | |
b0a873eb | 7658 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7659 | { |
b0a873eb PZ |
7660 | mutex_lock(&pmus_lock); |
7661 | list_del_rcu(&pmu->entry); | |
7662 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7663 | |
0475f9ea | 7664 | /* |
cde8e884 PZ |
7665 | * We dereference the pmu list under both SRCU and regular RCU, so |
7666 | * synchronize against both of those. | |
0475f9ea | 7667 | */ |
b0a873eb | 7668 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7669 | synchronize_rcu(); |
d6d020e9 | 7670 | |
33696fc0 | 7671 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7672 | if (pmu->type >= PERF_TYPE_MAX) |
7673 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7674 | device_del(pmu->dev); |
7675 | put_device(pmu->dev); | |
51676957 | 7676 | free_pmu_context(pmu); |
b0a873eb | 7677 | } |
c464c76e | 7678 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7679 | |
cc34b98b MR |
7680 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7681 | { | |
ccd41c86 | 7682 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7683 | int ret; |
7684 | ||
7685 | if (!try_module_get(pmu->module)) | |
7686 | return -ENODEV; | |
ccd41c86 PZ |
7687 | |
7688 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7689 | /* |
7690 | * This ctx->mutex can nest when we're called through | |
7691 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7692 | */ | |
7693 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7694 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7695 | BUG_ON(!ctx); |
7696 | } | |
7697 | ||
cc34b98b MR |
7698 | event->pmu = pmu; |
7699 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7700 | |
7701 | if (ctx) | |
7702 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7703 | ||
cc34b98b MR |
7704 | if (ret) |
7705 | module_put(pmu->module); | |
7706 | ||
7707 | return ret; | |
7708 | } | |
7709 | ||
18ab2cd3 | 7710 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7711 | { |
7712 | struct pmu *pmu = NULL; | |
7713 | int idx; | |
940c5b29 | 7714 | int ret; |
b0a873eb PZ |
7715 | |
7716 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7717 | |
7718 | rcu_read_lock(); | |
7719 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7720 | rcu_read_unlock(); | |
940c5b29 | 7721 | if (pmu) { |
cc34b98b | 7722 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7723 | if (ret) |
7724 | pmu = ERR_PTR(ret); | |
2e80a82a | 7725 | goto unlock; |
940c5b29 | 7726 | } |
2e80a82a | 7727 | |
b0a873eb | 7728 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7729 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7730 | if (!ret) |
e5f4d339 | 7731 | goto unlock; |
76e1d904 | 7732 | |
b0a873eb PZ |
7733 | if (ret != -ENOENT) { |
7734 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7735 | goto unlock; |
f344011c | 7736 | } |
5c92d124 | 7737 | } |
e5f4d339 PZ |
7738 | pmu = ERR_PTR(-ENOENT); |
7739 | unlock: | |
b0a873eb | 7740 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7741 | |
4aeb0b42 | 7742 | return pmu; |
5c92d124 IM |
7743 | } |
7744 | ||
4beb31f3 FW |
7745 | static void account_event_cpu(struct perf_event *event, int cpu) |
7746 | { | |
7747 | if (event->parent) | |
7748 | return; | |
7749 | ||
4beb31f3 FW |
7750 | if (is_cgroup_event(event)) |
7751 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7752 | } | |
7753 | ||
766d6c07 FW |
7754 | static void account_event(struct perf_event *event) |
7755 | { | |
4beb31f3 FW |
7756 | if (event->parent) |
7757 | return; | |
7758 | ||
766d6c07 FW |
7759 | if (event->attach_state & PERF_ATTACH_TASK) |
7760 | static_key_slow_inc(&perf_sched_events.key); | |
7761 | if (event->attr.mmap || event->attr.mmap_data) | |
7762 | atomic_inc(&nr_mmap_events); | |
7763 | if (event->attr.comm) | |
7764 | atomic_inc(&nr_comm_events); | |
7765 | if (event->attr.task) | |
7766 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7767 | if (event->attr.freq) { |
7768 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7769 | tick_nohz_full_kick_all(); | |
7770 | } | |
45ac1403 AH |
7771 | if (event->attr.context_switch) { |
7772 | atomic_inc(&nr_switch_events); | |
7773 | static_key_slow_inc(&perf_sched_events.key); | |
7774 | } | |
4beb31f3 | 7775 | if (has_branch_stack(event)) |
766d6c07 | 7776 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 | 7777 | if (is_cgroup_event(event)) |
766d6c07 | 7778 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7779 | |
7780 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7781 | } |
7782 | ||
0793a61d | 7783 | /* |
cdd6c482 | 7784 | * Allocate and initialize a event structure |
0793a61d | 7785 | */ |
cdd6c482 | 7786 | static struct perf_event * |
c3f00c70 | 7787 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7788 | struct task_struct *task, |
7789 | struct perf_event *group_leader, | |
7790 | struct perf_event *parent_event, | |
4dc0da86 | 7791 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7792 | void *context, int cgroup_fd) |
0793a61d | 7793 | { |
51b0fe39 | 7794 | struct pmu *pmu; |
cdd6c482 IM |
7795 | struct perf_event *event; |
7796 | struct hw_perf_event *hwc; | |
90983b16 | 7797 | long err = -EINVAL; |
0793a61d | 7798 | |
66832eb4 ON |
7799 | if ((unsigned)cpu >= nr_cpu_ids) { |
7800 | if (!task || cpu != -1) | |
7801 | return ERR_PTR(-EINVAL); | |
7802 | } | |
7803 | ||
c3f00c70 | 7804 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7805 | if (!event) |
d5d2bc0d | 7806 | return ERR_PTR(-ENOMEM); |
0793a61d | 7807 | |
04289bb9 | 7808 | /* |
cdd6c482 | 7809 | * Single events are their own group leaders, with an |
04289bb9 IM |
7810 | * empty sibling list: |
7811 | */ | |
7812 | if (!group_leader) | |
cdd6c482 | 7813 | group_leader = event; |
04289bb9 | 7814 | |
cdd6c482 IM |
7815 | mutex_init(&event->child_mutex); |
7816 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7817 | |
cdd6c482 IM |
7818 | INIT_LIST_HEAD(&event->group_entry); |
7819 | INIT_LIST_HEAD(&event->event_entry); | |
7820 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7821 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7822 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7823 | INIT_HLIST_NODE(&event->hlist_entry); |
7824 | ||
10c6db11 | 7825 | |
cdd6c482 | 7826 | init_waitqueue_head(&event->waitq); |
e360adbe | 7827 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7828 | |
cdd6c482 | 7829 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7830 | |
a6fa941d | 7831 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7832 | event->cpu = cpu; |
7833 | event->attr = *attr; | |
7834 | event->group_leader = group_leader; | |
7835 | event->pmu = NULL; | |
cdd6c482 | 7836 | event->oncpu = -1; |
a96bbc16 | 7837 | |
cdd6c482 | 7838 | event->parent = parent_event; |
b84fbc9f | 7839 | |
17cf22c3 | 7840 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7841 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7842 | |
cdd6c482 | 7843 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7844 | |
d580ff86 PZ |
7845 | if (task) { |
7846 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7847 | /* |
50f16a8b PZ |
7848 | * XXX pmu::event_init needs to know what task to account to |
7849 | * and we cannot use the ctx information because we need the | |
7850 | * pmu before we get a ctx. | |
d580ff86 | 7851 | */ |
50f16a8b | 7852 | event->hw.target = task; |
d580ff86 PZ |
7853 | } |
7854 | ||
34f43927 PZ |
7855 | event->clock = &local_clock; |
7856 | if (parent_event) | |
7857 | event->clock = parent_event->clock; | |
7858 | ||
4dc0da86 | 7859 | if (!overflow_handler && parent_event) { |
b326e956 | 7860 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7861 | context = parent_event->overflow_handler_context; |
7862 | } | |
66832eb4 | 7863 | |
b326e956 | 7864 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7865 | event->overflow_handler_context = context; |
97eaf530 | 7866 | |
0231bb53 | 7867 | perf_event__state_init(event); |
a86ed508 | 7868 | |
4aeb0b42 | 7869 | pmu = NULL; |
b8e83514 | 7870 | |
cdd6c482 | 7871 | hwc = &event->hw; |
bd2b5b12 | 7872 | hwc->sample_period = attr->sample_period; |
0d48696f | 7873 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7874 | hwc->sample_period = 1; |
eced1dfc | 7875 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7876 | |
e7850595 | 7877 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7878 | |
2023b359 | 7879 | /* |
cdd6c482 | 7880 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7881 | */ |
3dab77fb | 7882 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7883 | goto err_ns; |
a46a2300 YZ |
7884 | |
7885 | if (!has_branch_stack(event)) | |
7886 | event->attr.branch_sample_type = 0; | |
2023b359 | 7887 | |
79dff51e MF |
7888 | if (cgroup_fd != -1) { |
7889 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7890 | if (err) | |
7891 | goto err_ns; | |
7892 | } | |
7893 | ||
b0a873eb | 7894 | pmu = perf_init_event(event); |
4aeb0b42 | 7895 | if (!pmu) |
90983b16 FW |
7896 | goto err_ns; |
7897 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7898 | err = PTR_ERR(pmu); |
90983b16 | 7899 | goto err_ns; |
621a01ea | 7900 | } |
d5d2bc0d | 7901 | |
bed5b25a AS |
7902 | err = exclusive_event_init(event); |
7903 | if (err) | |
7904 | goto err_pmu; | |
7905 | ||
cdd6c482 | 7906 | if (!event->parent) { |
927c7a9e FW |
7907 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7908 | err = get_callchain_buffers(); | |
90983b16 | 7909 | if (err) |
bed5b25a | 7910 | goto err_per_task; |
d010b332 | 7911 | } |
f344011c | 7912 | } |
9ee318a7 | 7913 | |
cdd6c482 | 7914 | return event; |
90983b16 | 7915 | |
bed5b25a AS |
7916 | err_per_task: |
7917 | exclusive_event_destroy(event); | |
7918 | ||
90983b16 FW |
7919 | err_pmu: |
7920 | if (event->destroy) | |
7921 | event->destroy(event); | |
c464c76e | 7922 | module_put(pmu->module); |
90983b16 | 7923 | err_ns: |
79dff51e MF |
7924 | if (is_cgroup_event(event)) |
7925 | perf_detach_cgroup(event); | |
90983b16 FW |
7926 | if (event->ns) |
7927 | put_pid_ns(event->ns); | |
7928 | kfree(event); | |
7929 | ||
7930 | return ERR_PTR(err); | |
0793a61d TG |
7931 | } |
7932 | ||
cdd6c482 IM |
7933 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7934 | struct perf_event_attr *attr) | |
974802ea | 7935 | { |
974802ea | 7936 | u32 size; |
cdf8073d | 7937 | int ret; |
974802ea PZ |
7938 | |
7939 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7940 | return -EFAULT; | |
7941 | ||
7942 | /* | |
7943 | * zero the full structure, so that a short copy will be nice. | |
7944 | */ | |
7945 | memset(attr, 0, sizeof(*attr)); | |
7946 | ||
7947 | ret = get_user(size, &uattr->size); | |
7948 | if (ret) | |
7949 | return ret; | |
7950 | ||
7951 | if (size > PAGE_SIZE) /* silly large */ | |
7952 | goto err_size; | |
7953 | ||
7954 | if (!size) /* abi compat */ | |
7955 | size = PERF_ATTR_SIZE_VER0; | |
7956 | ||
7957 | if (size < PERF_ATTR_SIZE_VER0) | |
7958 | goto err_size; | |
7959 | ||
7960 | /* | |
7961 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7962 | * ensure all the unknown bits are 0 - i.e. new |
7963 | * user-space does not rely on any kernel feature | |
7964 | * extensions we dont know about yet. | |
974802ea PZ |
7965 | */ |
7966 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7967 | unsigned char __user *addr; |
7968 | unsigned char __user *end; | |
7969 | unsigned char val; | |
974802ea | 7970 | |
cdf8073d IS |
7971 | addr = (void __user *)uattr + sizeof(*attr); |
7972 | end = (void __user *)uattr + size; | |
974802ea | 7973 | |
cdf8073d | 7974 | for (; addr < end; addr++) { |
974802ea PZ |
7975 | ret = get_user(val, addr); |
7976 | if (ret) | |
7977 | return ret; | |
7978 | if (val) | |
7979 | goto err_size; | |
7980 | } | |
b3e62e35 | 7981 | size = sizeof(*attr); |
974802ea PZ |
7982 | } |
7983 | ||
7984 | ret = copy_from_user(attr, uattr, size); | |
7985 | if (ret) | |
7986 | return -EFAULT; | |
7987 | ||
cd757645 | 7988 | if (attr->__reserved_1) |
974802ea PZ |
7989 | return -EINVAL; |
7990 | ||
7991 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
7992 | return -EINVAL; | |
7993 | ||
7994 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
7995 | return -EINVAL; | |
7996 | ||
bce38cd5 SE |
7997 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
7998 | u64 mask = attr->branch_sample_type; | |
7999 | ||
8000 | /* only using defined bits */ | |
8001 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8002 | return -EINVAL; | |
8003 | ||
8004 | /* at least one branch bit must be set */ | |
8005 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8006 | return -EINVAL; | |
8007 | ||
bce38cd5 SE |
8008 | /* propagate priv level, when not set for branch */ |
8009 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8010 | ||
8011 | /* exclude_kernel checked on syscall entry */ | |
8012 | if (!attr->exclude_kernel) | |
8013 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8014 | ||
8015 | if (!attr->exclude_user) | |
8016 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8017 | ||
8018 | if (!attr->exclude_hv) | |
8019 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8020 | /* | |
8021 | * adjust user setting (for HW filter setup) | |
8022 | */ | |
8023 | attr->branch_sample_type = mask; | |
8024 | } | |
e712209a SE |
8025 | /* privileged levels capture (kernel, hv): check permissions */ |
8026 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8027 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8028 | return -EACCES; | |
bce38cd5 | 8029 | } |
4018994f | 8030 | |
c5ebcedb | 8031 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8032 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8033 | if (ret) |
8034 | return ret; | |
8035 | } | |
8036 | ||
8037 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8038 | if (!arch_perf_have_user_stack_dump()) | |
8039 | return -ENOSYS; | |
8040 | ||
8041 | /* | |
8042 | * We have __u32 type for the size, but so far | |
8043 | * we can only use __u16 as maximum due to the | |
8044 | * __u16 sample size limit. | |
8045 | */ | |
8046 | if (attr->sample_stack_user >= USHRT_MAX) | |
8047 | ret = -EINVAL; | |
8048 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8049 | ret = -EINVAL; | |
8050 | } | |
4018994f | 8051 | |
60e2364e SE |
8052 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8053 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8054 | out: |
8055 | return ret; | |
8056 | ||
8057 | err_size: | |
8058 | put_user(sizeof(*attr), &uattr->size); | |
8059 | ret = -E2BIG; | |
8060 | goto out; | |
8061 | } | |
8062 | ||
ac9721f3 PZ |
8063 | static int |
8064 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8065 | { |
b69cf536 | 8066 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8067 | int ret = -EINVAL; |
8068 | ||
ac9721f3 | 8069 | if (!output_event) |
a4be7c27 PZ |
8070 | goto set; |
8071 | ||
ac9721f3 PZ |
8072 | /* don't allow circular references */ |
8073 | if (event == output_event) | |
a4be7c27 PZ |
8074 | goto out; |
8075 | ||
0f139300 PZ |
8076 | /* |
8077 | * Don't allow cross-cpu buffers | |
8078 | */ | |
8079 | if (output_event->cpu != event->cpu) | |
8080 | goto out; | |
8081 | ||
8082 | /* | |
76369139 | 8083 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8084 | */ |
8085 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8086 | goto out; | |
8087 | ||
34f43927 PZ |
8088 | /* |
8089 | * Mixing clocks in the same buffer is trouble you don't need. | |
8090 | */ | |
8091 | if (output_event->clock != event->clock) | |
8092 | goto out; | |
8093 | ||
45bfb2e5 PZ |
8094 | /* |
8095 | * If both events generate aux data, they must be on the same PMU | |
8096 | */ | |
8097 | if (has_aux(event) && has_aux(output_event) && | |
8098 | event->pmu != output_event->pmu) | |
8099 | goto out; | |
8100 | ||
a4be7c27 | 8101 | set: |
cdd6c482 | 8102 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8103 | /* Can't redirect output if we've got an active mmap() */ |
8104 | if (atomic_read(&event->mmap_count)) | |
8105 | goto unlock; | |
a4be7c27 | 8106 | |
ac9721f3 | 8107 | if (output_event) { |
76369139 FW |
8108 | /* get the rb we want to redirect to */ |
8109 | rb = ring_buffer_get(output_event); | |
8110 | if (!rb) | |
ac9721f3 | 8111 | goto unlock; |
a4be7c27 PZ |
8112 | } |
8113 | ||
b69cf536 | 8114 | ring_buffer_attach(event, rb); |
9bb5d40c | 8115 | |
a4be7c27 | 8116 | ret = 0; |
ac9721f3 PZ |
8117 | unlock: |
8118 | mutex_unlock(&event->mmap_mutex); | |
8119 | ||
a4be7c27 | 8120 | out: |
a4be7c27 PZ |
8121 | return ret; |
8122 | } | |
8123 | ||
f63a8daa PZ |
8124 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8125 | { | |
8126 | if (b < a) | |
8127 | swap(a, b); | |
8128 | ||
8129 | mutex_lock(a); | |
8130 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8131 | } | |
8132 | ||
34f43927 PZ |
8133 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8134 | { | |
8135 | bool nmi_safe = false; | |
8136 | ||
8137 | switch (clk_id) { | |
8138 | case CLOCK_MONOTONIC: | |
8139 | event->clock = &ktime_get_mono_fast_ns; | |
8140 | nmi_safe = true; | |
8141 | break; | |
8142 | ||
8143 | case CLOCK_MONOTONIC_RAW: | |
8144 | event->clock = &ktime_get_raw_fast_ns; | |
8145 | nmi_safe = true; | |
8146 | break; | |
8147 | ||
8148 | case CLOCK_REALTIME: | |
8149 | event->clock = &ktime_get_real_ns; | |
8150 | break; | |
8151 | ||
8152 | case CLOCK_BOOTTIME: | |
8153 | event->clock = &ktime_get_boot_ns; | |
8154 | break; | |
8155 | ||
8156 | case CLOCK_TAI: | |
8157 | event->clock = &ktime_get_tai_ns; | |
8158 | break; | |
8159 | ||
8160 | default: | |
8161 | return -EINVAL; | |
8162 | } | |
8163 | ||
8164 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8165 | return -EINVAL; | |
8166 | ||
8167 | return 0; | |
8168 | } | |
8169 | ||
0793a61d | 8170 | /** |
cdd6c482 | 8171 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8172 | * |
cdd6c482 | 8173 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8174 | * @pid: target pid |
9f66a381 | 8175 | * @cpu: target cpu |
cdd6c482 | 8176 | * @group_fd: group leader event fd |
0793a61d | 8177 | */ |
cdd6c482 IM |
8178 | SYSCALL_DEFINE5(perf_event_open, |
8179 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8180 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8181 | { |
b04243ef PZ |
8182 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8183 | struct perf_event *event, *sibling; | |
cdd6c482 | 8184 | struct perf_event_attr attr; |
f63a8daa | 8185 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8186 | struct file *event_file = NULL; |
2903ff01 | 8187 | struct fd group = {NULL, 0}; |
38a81da2 | 8188 | struct task_struct *task = NULL; |
89a1e187 | 8189 | struct pmu *pmu; |
ea635c64 | 8190 | int event_fd; |
b04243ef | 8191 | int move_group = 0; |
dc86cabe | 8192 | int err; |
a21b0b35 | 8193 | int f_flags = O_RDWR; |
79dff51e | 8194 | int cgroup_fd = -1; |
0793a61d | 8195 | |
2743a5b0 | 8196 | /* for future expandability... */ |
e5d1367f | 8197 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8198 | return -EINVAL; |
8199 | ||
dc86cabe IM |
8200 | err = perf_copy_attr(attr_uptr, &attr); |
8201 | if (err) | |
8202 | return err; | |
eab656ae | 8203 | |
0764771d PZ |
8204 | if (!attr.exclude_kernel) { |
8205 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8206 | return -EACCES; | |
8207 | } | |
8208 | ||
df58ab24 | 8209 | if (attr.freq) { |
cdd6c482 | 8210 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8211 | return -EINVAL; |
0819b2e3 PZ |
8212 | } else { |
8213 | if (attr.sample_period & (1ULL << 63)) | |
8214 | return -EINVAL; | |
df58ab24 PZ |
8215 | } |
8216 | ||
e5d1367f SE |
8217 | /* |
8218 | * In cgroup mode, the pid argument is used to pass the fd | |
8219 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8220 | * designates the cpu on which to monitor threads from that | |
8221 | * cgroup. | |
8222 | */ | |
8223 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8224 | return -EINVAL; | |
8225 | ||
a21b0b35 YD |
8226 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8227 | f_flags |= O_CLOEXEC; | |
8228 | ||
8229 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8230 | if (event_fd < 0) |
8231 | return event_fd; | |
8232 | ||
ac9721f3 | 8233 | if (group_fd != -1) { |
2903ff01 AV |
8234 | err = perf_fget_light(group_fd, &group); |
8235 | if (err) | |
d14b12d7 | 8236 | goto err_fd; |
2903ff01 | 8237 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8238 | if (flags & PERF_FLAG_FD_OUTPUT) |
8239 | output_event = group_leader; | |
8240 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8241 | group_leader = NULL; | |
8242 | } | |
8243 | ||
e5d1367f | 8244 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8245 | task = find_lively_task_by_vpid(pid); |
8246 | if (IS_ERR(task)) { | |
8247 | err = PTR_ERR(task); | |
8248 | goto err_group_fd; | |
8249 | } | |
8250 | } | |
8251 | ||
1f4ee503 PZ |
8252 | if (task && group_leader && |
8253 | group_leader->attr.inherit != attr.inherit) { | |
8254 | err = -EINVAL; | |
8255 | goto err_task; | |
8256 | } | |
8257 | ||
fbfc623f YZ |
8258 | get_online_cpus(); |
8259 | ||
79dff51e MF |
8260 | if (flags & PERF_FLAG_PID_CGROUP) |
8261 | cgroup_fd = pid; | |
8262 | ||
4dc0da86 | 8263 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8264 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8265 | if (IS_ERR(event)) { |
8266 | err = PTR_ERR(event); | |
1f4ee503 | 8267 | goto err_cpus; |
d14b12d7 SE |
8268 | } |
8269 | ||
53b25335 VW |
8270 | if (is_sampling_event(event)) { |
8271 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8272 | err = -ENOTSUPP; | |
8273 | goto err_alloc; | |
8274 | } | |
8275 | } | |
8276 | ||
766d6c07 FW |
8277 | account_event(event); |
8278 | ||
89a1e187 PZ |
8279 | /* |
8280 | * Special case software events and allow them to be part of | |
8281 | * any hardware group. | |
8282 | */ | |
8283 | pmu = event->pmu; | |
b04243ef | 8284 | |
34f43927 PZ |
8285 | if (attr.use_clockid) { |
8286 | err = perf_event_set_clock(event, attr.clockid); | |
8287 | if (err) | |
8288 | goto err_alloc; | |
8289 | } | |
8290 | ||
b04243ef PZ |
8291 | if (group_leader && |
8292 | (is_software_event(event) != is_software_event(group_leader))) { | |
8293 | if (is_software_event(event)) { | |
8294 | /* | |
8295 | * If event and group_leader are not both a software | |
8296 | * event, and event is, then group leader is not. | |
8297 | * | |
8298 | * Allow the addition of software events to !software | |
8299 | * groups, this is safe because software events never | |
8300 | * fail to schedule. | |
8301 | */ | |
8302 | pmu = group_leader->pmu; | |
8303 | } else if (is_software_event(group_leader) && | |
8304 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8305 | /* | |
8306 | * In case the group is a pure software group, and we | |
8307 | * try to add a hardware event, move the whole group to | |
8308 | * the hardware context. | |
8309 | */ | |
8310 | move_group = 1; | |
8311 | } | |
8312 | } | |
89a1e187 PZ |
8313 | |
8314 | /* | |
8315 | * Get the target context (task or percpu): | |
8316 | */ | |
4af57ef2 | 8317 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8318 | if (IS_ERR(ctx)) { |
8319 | err = PTR_ERR(ctx); | |
c6be5a5c | 8320 | goto err_alloc; |
89a1e187 PZ |
8321 | } |
8322 | ||
bed5b25a AS |
8323 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8324 | err = -EBUSY; | |
8325 | goto err_context; | |
8326 | } | |
8327 | ||
fd1edb3a PZ |
8328 | if (task) { |
8329 | put_task_struct(task); | |
8330 | task = NULL; | |
8331 | } | |
8332 | ||
ccff286d | 8333 | /* |
cdd6c482 | 8334 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8335 | */ |
ac9721f3 | 8336 | if (group_leader) { |
dc86cabe | 8337 | err = -EINVAL; |
04289bb9 | 8338 | |
04289bb9 | 8339 | /* |
ccff286d IM |
8340 | * Do not allow a recursive hierarchy (this new sibling |
8341 | * becoming part of another group-sibling): | |
8342 | */ | |
8343 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8344 | goto err_context; |
34f43927 PZ |
8345 | |
8346 | /* All events in a group should have the same clock */ | |
8347 | if (group_leader->clock != event->clock) | |
8348 | goto err_context; | |
8349 | ||
ccff286d IM |
8350 | /* |
8351 | * Do not allow to attach to a group in a different | |
8352 | * task or CPU context: | |
04289bb9 | 8353 | */ |
b04243ef | 8354 | if (move_group) { |
c3c87e77 PZ |
8355 | /* |
8356 | * Make sure we're both on the same task, or both | |
8357 | * per-cpu events. | |
8358 | */ | |
8359 | if (group_leader->ctx->task != ctx->task) | |
8360 | goto err_context; | |
8361 | ||
8362 | /* | |
8363 | * Make sure we're both events for the same CPU; | |
8364 | * grouping events for different CPUs is broken; since | |
8365 | * you can never concurrently schedule them anyhow. | |
8366 | */ | |
8367 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8368 | goto err_context; |
8369 | } else { | |
8370 | if (group_leader->ctx != ctx) | |
8371 | goto err_context; | |
8372 | } | |
8373 | ||
3b6f9e5c PM |
8374 | /* |
8375 | * Only a group leader can be exclusive or pinned | |
8376 | */ | |
0d48696f | 8377 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8378 | goto err_context; |
ac9721f3 PZ |
8379 | } |
8380 | ||
8381 | if (output_event) { | |
8382 | err = perf_event_set_output(event, output_event); | |
8383 | if (err) | |
c3f00c70 | 8384 | goto err_context; |
ac9721f3 | 8385 | } |
0793a61d | 8386 | |
a21b0b35 YD |
8387 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8388 | f_flags); | |
ea635c64 AV |
8389 | if (IS_ERR(event_file)) { |
8390 | err = PTR_ERR(event_file); | |
c3f00c70 | 8391 | goto err_context; |
ea635c64 | 8392 | } |
9b51f66d | 8393 | |
b04243ef | 8394 | if (move_group) { |
f63a8daa | 8395 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8396 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8397 | } else { | |
8398 | mutex_lock(&ctx->mutex); | |
8399 | } | |
8400 | ||
a723968c PZ |
8401 | if (!perf_event_validate_size(event)) { |
8402 | err = -E2BIG; | |
8403 | goto err_locked; | |
8404 | } | |
8405 | ||
f55fc2a5 PZ |
8406 | /* |
8407 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8408 | * because we need to serialize with concurrent event creation. | |
8409 | */ | |
8410 | if (!exclusive_event_installable(event, ctx)) { | |
8411 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8412 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8413 | |
f55fc2a5 PZ |
8414 | err = -EBUSY; |
8415 | goto err_locked; | |
8416 | } | |
f63a8daa | 8417 | |
f55fc2a5 PZ |
8418 | WARN_ON_ONCE(ctx->parent_ctx); |
8419 | ||
8420 | if (move_group) { | |
f63a8daa PZ |
8421 | /* |
8422 | * See perf_event_ctx_lock() for comments on the details | |
8423 | * of swizzling perf_event::ctx. | |
8424 | */ | |
46ce0fe9 | 8425 | perf_remove_from_context(group_leader, false); |
0231bb53 | 8426 | |
b04243ef PZ |
8427 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8428 | group_entry) { | |
46ce0fe9 | 8429 | perf_remove_from_context(sibling, false); |
b04243ef PZ |
8430 | put_ctx(gctx); |
8431 | } | |
b04243ef | 8432 | |
f63a8daa PZ |
8433 | /* |
8434 | * Wait for everybody to stop referencing the events through | |
8435 | * the old lists, before installing it on new lists. | |
8436 | */ | |
0cda4c02 | 8437 | synchronize_rcu(); |
f63a8daa | 8438 | |
8f95b435 PZI |
8439 | /* |
8440 | * Install the group siblings before the group leader. | |
8441 | * | |
8442 | * Because a group leader will try and install the entire group | |
8443 | * (through the sibling list, which is still in-tact), we can | |
8444 | * end up with siblings installed in the wrong context. | |
8445 | * | |
8446 | * By installing siblings first we NO-OP because they're not | |
8447 | * reachable through the group lists. | |
8448 | */ | |
b04243ef PZ |
8449 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8450 | group_entry) { | |
8f95b435 | 8451 | perf_event__state_init(sibling); |
9fc81d87 | 8452 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8453 | get_ctx(ctx); |
8454 | } | |
8f95b435 PZI |
8455 | |
8456 | /* | |
8457 | * Removing from the context ends up with disabled | |
8458 | * event. What we want here is event in the initial | |
8459 | * startup state, ready to be add into new context. | |
8460 | */ | |
8461 | perf_event__state_init(group_leader); | |
8462 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8463 | get_ctx(ctx); | |
b04243ef | 8464 | |
f55fc2a5 PZ |
8465 | /* |
8466 | * Now that all events are installed in @ctx, nothing | |
8467 | * references @gctx anymore, so drop the last reference we have | |
8468 | * on it. | |
8469 | */ | |
8470 | put_ctx(gctx); | |
bed5b25a AS |
8471 | } |
8472 | ||
f73e22ab PZ |
8473 | /* |
8474 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8475 | * that we're serialized against further additions and before | |
8476 | * perf_install_in_context() which is the point the event is active and | |
8477 | * can use these values. | |
8478 | */ | |
8479 | perf_event__header_size(event); | |
8480 | perf_event__id_header_size(event); | |
8481 | ||
e2d37cd2 | 8482 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8483 | perf_unpin_context(ctx); |
f63a8daa | 8484 | |
f55fc2a5 | 8485 | if (move_group) |
f63a8daa | 8486 | mutex_unlock(&gctx->mutex); |
d859e29f | 8487 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8488 | |
fbfc623f YZ |
8489 | put_online_cpus(); |
8490 | ||
cdd6c482 | 8491 | event->owner = current; |
8882135b | 8492 | |
cdd6c482 IM |
8493 | mutex_lock(¤t->perf_event_mutex); |
8494 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8495 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8496 | |
8a49542c PZ |
8497 | /* |
8498 | * Drop the reference on the group_event after placing the | |
8499 | * new event on the sibling_list. This ensures destruction | |
8500 | * of the group leader will find the pointer to itself in | |
8501 | * perf_group_detach(). | |
8502 | */ | |
2903ff01 | 8503 | fdput(group); |
ea635c64 AV |
8504 | fd_install(event_fd, event_file); |
8505 | return event_fd; | |
0793a61d | 8506 | |
f55fc2a5 PZ |
8507 | err_locked: |
8508 | if (move_group) | |
8509 | mutex_unlock(&gctx->mutex); | |
8510 | mutex_unlock(&ctx->mutex); | |
8511 | /* err_file: */ | |
8512 | fput(event_file); | |
c3f00c70 | 8513 | err_context: |
fe4b04fa | 8514 | perf_unpin_context(ctx); |
ea635c64 | 8515 | put_ctx(ctx); |
c6be5a5c | 8516 | err_alloc: |
ea635c64 | 8517 | free_event(event); |
1f4ee503 | 8518 | err_cpus: |
fbfc623f | 8519 | put_online_cpus(); |
1f4ee503 | 8520 | err_task: |
e7d0bc04 PZ |
8521 | if (task) |
8522 | put_task_struct(task); | |
89a1e187 | 8523 | err_group_fd: |
2903ff01 | 8524 | fdput(group); |
ea635c64 AV |
8525 | err_fd: |
8526 | put_unused_fd(event_fd); | |
dc86cabe | 8527 | return err; |
0793a61d TG |
8528 | } |
8529 | ||
fb0459d7 AV |
8530 | /** |
8531 | * perf_event_create_kernel_counter | |
8532 | * | |
8533 | * @attr: attributes of the counter to create | |
8534 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8535 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8536 | */ |
8537 | struct perf_event * | |
8538 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8539 | struct task_struct *task, |
4dc0da86 AK |
8540 | perf_overflow_handler_t overflow_handler, |
8541 | void *context) | |
fb0459d7 | 8542 | { |
fb0459d7 | 8543 | struct perf_event_context *ctx; |
c3f00c70 | 8544 | struct perf_event *event; |
fb0459d7 | 8545 | int err; |
d859e29f | 8546 | |
fb0459d7 AV |
8547 | /* |
8548 | * Get the target context (task or percpu): | |
8549 | */ | |
d859e29f | 8550 | |
4dc0da86 | 8551 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8552 | overflow_handler, context, -1); |
c3f00c70 PZ |
8553 | if (IS_ERR(event)) { |
8554 | err = PTR_ERR(event); | |
8555 | goto err; | |
8556 | } | |
d859e29f | 8557 | |
f8697762 JO |
8558 | /* Mark owner so we could distinguish it from user events. */ |
8559 | event->owner = EVENT_OWNER_KERNEL; | |
8560 | ||
766d6c07 FW |
8561 | account_event(event); |
8562 | ||
4af57ef2 | 8563 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8564 | if (IS_ERR(ctx)) { |
8565 | err = PTR_ERR(ctx); | |
c3f00c70 | 8566 | goto err_free; |
d859e29f | 8567 | } |
fb0459d7 | 8568 | |
fb0459d7 AV |
8569 | WARN_ON_ONCE(ctx->parent_ctx); |
8570 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8571 | if (!exclusive_event_installable(event, ctx)) { |
8572 | mutex_unlock(&ctx->mutex); | |
8573 | perf_unpin_context(ctx); | |
8574 | put_ctx(ctx); | |
8575 | err = -EBUSY; | |
8576 | goto err_free; | |
8577 | } | |
8578 | ||
fb0459d7 | 8579 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8580 | perf_unpin_context(ctx); |
fb0459d7 AV |
8581 | mutex_unlock(&ctx->mutex); |
8582 | ||
fb0459d7 AV |
8583 | return event; |
8584 | ||
c3f00c70 PZ |
8585 | err_free: |
8586 | free_event(event); | |
8587 | err: | |
c6567f64 | 8588 | return ERR_PTR(err); |
9b51f66d | 8589 | } |
fb0459d7 | 8590 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8591 | |
0cda4c02 YZ |
8592 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8593 | { | |
8594 | struct perf_event_context *src_ctx; | |
8595 | struct perf_event_context *dst_ctx; | |
8596 | struct perf_event *event, *tmp; | |
8597 | LIST_HEAD(events); | |
8598 | ||
8599 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8600 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8601 | ||
f63a8daa PZ |
8602 | /* |
8603 | * See perf_event_ctx_lock() for comments on the details | |
8604 | * of swizzling perf_event::ctx. | |
8605 | */ | |
8606 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8607 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8608 | event_entry) { | |
46ce0fe9 | 8609 | perf_remove_from_context(event, false); |
9a545de0 | 8610 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8611 | put_ctx(src_ctx); |
9886167d | 8612 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8613 | } |
0cda4c02 | 8614 | |
8f95b435 PZI |
8615 | /* |
8616 | * Wait for the events to quiesce before re-instating them. | |
8617 | */ | |
0cda4c02 YZ |
8618 | synchronize_rcu(); |
8619 | ||
8f95b435 PZI |
8620 | /* |
8621 | * Re-instate events in 2 passes. | |
8622 | * | |
8623 | * Skip over group leaders and only install siblings on this first | |
8624 | * pass, siblings will not get enabled without a leader, however a | |
8625 | * leader will enable its siblings, even if those are still on the old | |
8626 | * context. | |
8627 | */ | |
8628 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8629 | if (event->group_leader == event) | |
8630 | continue; | |
8631 | ||
8632 | list_del(&event->migrate_entry); | |
8633 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8634 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8635 | account_event_cpu(event, dst_cpu); | |
8636 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8637 | get_ctx(dst_ctx); | |
8638 | } | |
8639 | ||
8640 | /* | |
8641 | * Once all the siblings are setup properly, install the group leaders | |
8642 | * to make it go. | |
8643 | */ | |
9886167d PZ |
8644 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8645 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8646 | if (event->state >= PERF_EVENT_STATE_OFF) |
8647 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8648 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8649 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8650 | get_ctx(dst_ctx); | |
8651 | } | |
8652 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8653 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8654 | } |
8655 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8656 | ||
cdd6c482 | 8657 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8658 | struct task_struct *child) |
d859e29f | 8659 | { |
cdd6c482 | 8660 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8661 | u64 child_val; |
d859e29f | 8662 | |
cdd6c482 IM |
8663 | if (child_event->attr.inherit_stat) |
8664 | perf_event_read_event(child_event, child); | |
38b200d6 | 8665 | |
b5e58793 | 8666 | child_val = perf_event_count(child_event); |
d859e29f PM |
8667 | |
8668 | /* | |
8669 | * Add back the child's count to the parent's count: | |
8670 | */ | |
a6e6dea6 | 8671 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8672 | atomic64_add(child_event->total_time_enabled, |
8673 | &parent_event->child_total_time_enabled); | |
8674 | atomic64_add(child_event->total_time_running, | |
8675 | &parent_event->child_total_time_running); | |
d859e29f PM |
8676 | |
8677 | /* | |
cdd6c482 | 8678 | * Remove this event from the parent's list |
d859e29f | 8679 | */ |
cdd6c482 IM |
8680 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
8681 | mutex_lock(&parent_event->child_mutex); | |
8682 | list_del_init(&child_event->child_list); | |
8683 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f | 8684 | |
dc633982 JO |
8685 | /* |
8686 | * Make sure user/parent get notified, that we just | |
8687 | * lost one event. | |
8688 | */ | |
8689 | perf_event_wakeup(parent_event); | |
8690 | ||
d859e29f | 8691 | /* |
cdd6c482 | 8692 | * Release the parent event, if this was the last |
d859e29f PM |
8693 | * reference to it. |
8694 | */ | |
a6fa941d | 8695 | put_event(parent_event); |
d859e29f PM |
8696 | } |
8697 | ||
9b51f66d | 8698 | static void |
cdd6c482 IM |
8699 | __perf_event_exit_task(struct perf_event *child_event, |
8700 | struct perf_event_context *child_ctx, | |
38b200d6 | 8701 | struct task_struct *child) |
9b51f66d | 8702 | { |
1903d50c PZ |
8703 | /* |
8704 | * Do not destroy the 'original' grouping; because of the context | |
8705 | * switch optimization the original events could've ended up in a | |
8706 | * random child task. | |
8707 | * | |
8708 | * If we were to destroy the original group, all group related | |
8709 | * operations would cease to function properly after this random | |
8710 | * child dies. | |
8711 | * | |
8712 | * Do destroy all inherited groups, we don't care about those | |
8713 | * and being thorough is better. | |
8714 | */ | |
8715 | perf_remove_from_context(child_event, !!child_event->parent); | |
0cc0c027 | 8716 | |
9b51f66d | 8717 | /* |
38b435b1 | 8718 | * It can happen that the parent exits first, and has events |
9b51f66d | 8719 | * that are still around due to the child reference. These |
38b435b1 | 8720 | * events need to be zapped. |
9b51f66d | 8721 | */ |
38b435b1 | 8722 | if (child_event->parent) { |
cdd6c482 IM |
8723 | sync_child_event(child_event, child); |
8724 | free_event(child_event); | |
179033b3 JO |
8725 | } else { |
8726 | child_event->state = PERF_EVENT_STATE_EXIT; | |
8727 | perf_event_wakeup(child_event); | |
4bcf349a | 8728 | } |
9b51f66d IM |
8729 | } |
8730 | ||
8dc85d54 | 8731 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8732 | { |
ebf905fc | 8733 | struct perf_event *child_event, *next; |
211de6eb | 8734 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
a63eaf34 | 8735 | unsigned long flags; |
9b51f66d | 8736 | |
4e93ad60 | 8737 | if (likely(!child->perf_event_ctxp[ctxn])) |
9b51f66d IM |
8738 | return; |
8739 | ||
a63eaf34 | 8740 | local_irq_save(flags); |
ad3a37de PM |
8741 | /* |
8742 | * We can't reschedule here because interrupts are disabled, | |
8743 | * and either child is current or it is a task that can't be | |
8744 | * scheduled, so we are now safe from rescheduling changing | |
8745 | * our context. | |
8746 | */ | |
806839b2 | 8747 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
8748 | |
8749 | /* | |
8750 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 8751 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
8752 | * incremented the context's refcount before we do put_ctx below. |
8753 | */ | |
e625cce1 | 8754 | raw_spin_lock(&child_ctx->lock); |
04dc2dbb | 8755 | task_ctx_sched_out(child_ctx); |
8dc85d54 | 8756 | child->perf_event_ctxp[ctxn] = NULL; |
4a1c0f26 | 8757 | |
71a851b4 PZ |
8758 | /* |
8759 | * If this context is a clone; unclone it so it can't get | |
8760 | * swapped to another process while we're removing all | |
cdd6c482 | 8761 | * the events from it. |
71a851b4 | 8762 | */ |
211de6eb | 8763 | clone_ctx = unclone_ctx(child_ctx); |
5e942bb3 | 8764 | update_context_time(child_ctx); |
e625cce1 | 8765 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
9f498cc5 | 8766 | |
211de6eb PZ |
8767 | if (clone_ctx) |
8768 | put_ctx(clone_ctx); | |
4a1c0f26 | 8769 | |
9f498cc5 | 8770 | /* |
cdd6c482 IM |
8771 | * Report the task dead after unscheduling the events so that we |
8772 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8773 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8774 | */ |
cdd6c482 | 8775 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8776 | |
66fff224 PZ |
8777 | /* |
8778 | * We can recurse on the same lock type through: | |
8779 | * | |
cdd6c482 IM |
8780 | * __perf_event_exit_task() |
8781 | * sync_child_event() | |
a6fa941d AV |
8782 | * put_event() |
8783 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
8784 | * |
8785 | * But since its the parent context it won't be the same instance. | |
8786 | */ | |
a0507c84 | 8787 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 8788 | |
ebf905fc | 8789 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
cdd6c482 | 8790 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 | 8791 | |
a63eaf34 PM |
8792 | mutex_unlock(&child_ctx->mutex); |
8793 | ||
8794 | put_ctx(child_ctx); | |
9b51f66d IM |
8795 | } |
8796 | ||
8dc85d54 PZ |
8797 | /* |
8798 | * When a child task exits, feed back event values to parent events. | |
8799 | */ | |
8800 | void perf_event_exit_task(struct task_struct *child) | |
8801 | { | |
8882135b | 8802 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8803 | int ctxn; |
8804 | ||
8882135b PZ |
8805 | mutex_lock(&child->perf_event_mutex); |
8806 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8807 | owner_entry) { | |
8808 | list_del_init(&event->owner_entry); | |
8809 | ||
8810 | /* | |
8811 | * Ensure the list deletion is visible before we clear | |
8812 | * the owner, closes a race against perf_release() where | |
8813 | * we need to serialize on the owner->perf_event_mutex. | |
8814 | */ | |
8815 | smp_wmb(); | |
8816 | event->owner = NULL; | |
8817 | } | |
8818 | mutex_unlock(&child->perf_event_mutex); | |
8819 | ||
8dc85d54 PZ |
8820 | for_each_task_context_nr(ctxn) |
8821 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8822 | |
8823 | /* | |
8824 | * The perf_event_exit_task_context calls perf_event_task | |
8825 | * with child's task_ctx, which generates EXIT events for | |
8826 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8827 | * At this point we need to send EXIT events to cpu contexts. | |
8828 | */ | |
8829 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8830 | } |
8831 | ||
889ff015 FW |
8832 | static void perf_free_event(struct perf_event *event, |
8833 | struct perf_event_context *ctx) | |
8834 | { | |
8835 | struct perf_event *parent = event->parent; | |
8836 | ||
8837 | if (WARN_ON_ONCE(!parent)) | |
8838 | return; | |
8839 | ||
8840 | mutex_lock(&parent->child_mutex); | |
8841 | list_del_init(&event->child_list); | |
8842 | mutex_unlock(&parent->child_mutex); | |
8843 | ||
a6fa941d | 8844 | put_event(parent); |
889ff015 | 8845 | |
652884fe | 8846 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8847 | perf_group_detach(event); |
889ff015 | 8848 | list_del_event(event, ctx); |
652884fe | 8849 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8850 | free_event(event); |
8851 | } | |
8852 | ||
bbbee908 | 8853 | /* |
652884fe | 8854 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8855 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8856 | * |
8857 | * Not all locks are strictly required, but take them anyway to be nice and | |
8858 | * help out with the lockdep assertions. | |
bbbee908 | 8859 | */ |
cdd6c482 | 8860 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8861 | { |
8dc85d54 | 8862 | struct perf_event_context *ctx; |
cdd6c482 | 8863 | struct perf_event *event, *tmp; |
8dc85d54 | 8864 | int ctxn; |
bbbee908 | 8865 | |
8dc85d54 PZ |
8866 | for_each_task_context_nr(ctxn) { |
8867 | ctx = task->perf_event_ctxp[ctxn]; | |
8868 | if (!ctx) | |
8869 | continue; | |
bbbee908 | 8870 | |
8dc85d54 | 8871 | mutex_lock(&ctx->mutex); |
bbbee908 | 8872 | again: |
8dc85d54 PZ |
8873 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8874 | group_entry) | |
8875 | perf_free_event(event, ctx); | |
bbbee908 | 8876 | |
8dc85d54 PZ |
8877 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8878 | group_entry) | |
8879 | perf_free_event(event, ctx); | |
bbbee908 | 8880 | |
8dc85d54 PZ |
8881 | if (!list_empty(&ctx->pinned_groups) || |
8882 | !list_empty(&ctx->flexible_groups)) | |
8883 | goto again; | |
bbbee908 | 8884 | |
8dc85d54 | 8885 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8886 | |
8dc85d54 PZ |
8887 | put_ctx(ctx); |
8888 | } | |
889ff015 FW |
8889 | } |
8890 | ||
4e231c79 PZ |
8891 | void perf_event_delayed_put(struct task_struct *task) |
8892 | { | |
8893 | int ctxn; | |
8894 | ||
8895 | for_each_task_context_nr(ctxn) | |
8896 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8897 | } | |
8898 | ||
ffe8690c KX |
8899 | struct perf_event *perf_event_get(unsigned int fd) |
8900 | { | |
8901 | int err; | |
8902 | struct fd f; | |
8903 | struct perf_event *event; | |
8904 | ||
8905 | err = perf_fget_light(fd, &f); | |
8906 | if (err) | |
8907 | return ERR_PTR(err); | |
8908 | ||
8909 | event = f.file->private_data; | |
8910 | atomic_long_inc(&event->refcount); | |
8911 | fdput(f); | |
8912 | ||
8913 | return event; | |
8914 | } | |
8915 | ||
8916 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8917 | { | |
8918 | if (!event) | |
8919 | return ERR_PTR(-EINVAL); | |
8920 | ||
8921 | return &event->attr; | |
8922 | } | |
8923 | ||
97dee4f3 PZ |
8924 | /* |
8925 | * inherit a event from parent task to child task: | |
8926 | */ | |
8927 | static struct perf_event * | |
8928 | inherit_event(struct perf_event *parent_event, | |
8929 | struct task_struct *parent, | |
8930 | struct perf_event_context *parent_ctx, | |
8931 | struct task_struct *child, | |
8932 | struct perf_event *group_leader, | |
8933 | struct perf_event_context *child_ctx) | |
8934 | { | |
1929def9 | 8935 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8936 | struct perf_event *child_event; |
cee010ec | 8937 | unsigned long flags; |
97dee4f3 PZ |
8938 | |
8939 | /* | |
8940 | * Instead of creating recursive hierarchies of events, | |
8941 | * we link inherited events back to the original parent, | |
8942 | * which has a filp for sure, which we use as the reference | |
8943 | * count: | |
8944 | */ | |
8945 | if (parent_event->parent) | |
8946 | parent_event = parent_event->parent; | |
8947 | ||
8948 | child_event = perf_event_alloc(&parent_event->attr, | |
8949 | parent_event->cpu, | |
d580ff86 | 8950 | child, |
97dee4f3 | 8951 | group_leader, parent_event, |
79dff51e | 8952 | NULL, NULL, -1); |
97dee4f3 PZ |
8953 | if (IS_ERR(child_event)) |
8954 | return child_event; | |
a6fa941d | 8955 | |
fadfe7be JO |
8956 | if (is_orphaned_event(parent_event) || |
8957 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
a6fa941d AV |
8958 | free_event(child_event); |
8959 | return NULL; | |
8960 | } | |
8961 | ||
97dee4f3 PZ |
8962 | get_ctx(child_ctx); |
8963 | ||
8964 | /* | |
8965 | * Make the child state follow the state of the parent event, | |
8966 | * not its attr.disabled bit. We hold the parent's mutex, | |
8967 | * so we won't race with perf_event_{en, dis}able_family. | |
8968 | */ | |
1929def9 | 8969 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8970 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8971 | else | |
8972 | child_event->state = PERF_EVENT_STATE_OFF; | |
8973 | ||
8974 | if (parent_event->attr.freq) { | |
8975 | u64 sample_period = parent_event->hw.sample_period; | |
8976 | struct hw_perf_event *hwc = &child_event->hw; | |
8977 | ||
8978 | hwc->sample_period = sample_period; | |
8979 | hwc->last_period = sample_period; | |
8980 | ||
8981 | local64_set(&hwc->period_left, sample_period); | |
8982 | } | |
8983 | ||
8984 | child_event->ctx = child_ctx; | |
8985 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
8986 | child_event->overflow_handler_context |
8987 | = parent_event->overflow_handler_context; | |
97dee4f3 | 8988 | |
614b6780 TG |
8989 | /* |
8990 | * Precalculate sample_data sizes | |
8991 | */ | |
8992 | perf_event__header_size(child_event); | |
6844c09d | 8993 | perf_event__id_header_size(child_event); |
614b6780 | 8994 | |
97dee4f3 PZ |
8995 | /* |
8996 | * Link it up in the child's context: | |
8997 | */ | |
cee010ec | 8998 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 8999 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9000 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9001 | |
97dee4f3 PZ |
9002 | /* |
9003 | * Link this into the parent event's child list | |
9004 | */ | |
9005 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
9006 | mutex_lock(&parent_event->child_mutex); | |
9007 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
9008 | mutex_unlock(&parent_event->child_mutex); | |
9009 | ||
9010 | return child_event; | |
9011 | } | |
9012 | ||
9013 | static int inherit_group(struct perf_event *parent_event, | |
9014 | struct task_struct *parent, | |
9015 | struct perf_event_context *parent_ctx, | |
9016 | struct task_struct *child, | |
9017 | struct perf_event_context *child_ctx) | |
9018 | { | |
9019 | struct perf_event *leader; | |
9020 | struct perf_event *sub; | |
9021 | struct perf_event *child_ctr; | |
9022 | ||
9023 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9024 | child, NULL, child_ctx); | |
9025 | if (IS_ERR(leader)) | |
9026 | return PTR_ERR(leader); | |
9027 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9028 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9029 | child, leader, child_ctx); | |
9030 | if (IS_ERR(child_ctr)) | |
9031 | return PTR_ERR(child_ctr); | |
9032 | } | |
9033 | return 0; | |
889ff015 FW |
9034 | } |
9035 | ||
9036 | static int | |
9037 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9038 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9039 | struct task_struct *child, int ctxn, |
889ff015 FW |
9040 | int *inherited_all) |
9041 | { | |
9042 | int ret; | |
8dc85d54 | 9043 | struct perf_event_context *child_ctx; |
889ff015 FW |
9044 | |
9045 | if (!event->attr.inherit) { | |
9046 | *inherited_all = 0; | |
9047 | return 0; | |
bbbee908 PZ |
9048 | } |
9049 | ||
fe4b04fa | 9050 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9051 | if (!child_ctx) { |
9052 | /* | |
9053 | * This is executed from the parent task context, so | |
9054 | * inherit events that have been marked for cloning. | |
9055 | * First allocate and initialize a context for the | |
9056 | * child. | |
9057 | */ | |
bbbee908 | 9058 | |
734df5ab | 9059 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9060 | if (!child_ctx) |
9061 | return -ENOMEM; | |
bbbee908 | 9062 | |
8dc85d54 | 9063 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9064 | } |
9065 | ||
9066 | ret = inherit_group(event, parent, parent_ctx, | |
9067 | child, child_ctx); | |
9068 | ||
9069 | if (ret) | |
9070 | *inherited_all = 0; | |
9071 | ||
9072 | return ret; | |
bbbee908 PZ |
9073 | } |
9074 | ||
9b51f66d | 9075 | /* |
cdd6c482 | 9076 | * Initialize the perf_event context in task_struct |
9b51f66d | 9077 | */ |
985c8dcb | 9078 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9079 | { |
889ff015 | 9080 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9081 | struct perf_event_context *cloned_ctx; |
9082 | struct perf_event *event; | |
9b51f66d | 9083 | struct task_struct *parent = current; |
564c2b21 | 9084 | int inherited_all = 1; |
dddd3379 | 9085 | unsigned long flags; |
6ab423e0 | 9086 | int ret = 0; |
9b51f66d | 9087 | |
8dc85d54 | 9088 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9089 | return 0; |
9090 | ||
ad3a37de | 9091 | /* |
25346b93 PM |
9092 | * If the parent's context is a clone, pin it so it won't get |
9093 | * swapped under us. | |
ad3a37de | 9094 | */ |
8dc85d54 | 9095 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9096 | if (!parent_ctx) |
9097 | return 0; | |
25346b93 | 9098 | |
ad3a37de PM |
9099 | /* |
9100 | * No need to check if parent_ctx != NULL here; since we saw | |
9101 | * it non-NULL earlier, the only reason for it to become NULL | |
9102 | * is if we exit, and since we're currently in the middle of | |
9103 | * a fork we can't be exiting at the same time. | |
9104 | */ | |
ad3a37de | 9105 | |
9b51f66d IM |
9106 | /* |
9107 | * Lock the parent list. No need to lock the child - not PID | |
9108 | * hashed yet and not running, so nobody can access it. | |
9109 | */ | |
d859e29f | 9110 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9111 | |
9112 | /* | |
9113 | * We dont have to disable NMIs - we are only looking at | |
9114 | * the list, not manipulating it: | |
9115 | */ | |
889ff015 | 9116 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9117 | ret = inherit_task_group(event, parent, parent_ctx, |
9118 | child, ctxn, &inherited_all); | |
889ff015 FW |
9119 | if (ret) |
9120 | break; | |
9121 | } | |
b93f7978 | 9122 | |
dddd3379 TG |
9123 | /* |
9124 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9125 | * to allocations, but we need to prevent rotation because | |
9126 | * rotate_ctx() will change the list from interrupt context. | |
9127 | */ | |
9128 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9129 | parent_ctx->rotate_disable = 1; | |
9130 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9131 | ||
889ff015 | 9132 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9133 | ret = inherit_task_group(event, parent, parent_ctx, |
9134 | child, ctxn, &inherited_all); | |
889ff015 | 9135 | if (ret) |
9b51f66d | 9136 | break; |
564c2b21 PM |
9137 | } |
9138 | ||
dddd3379 TG |
9139 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9140 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9141 | |
8dc85d54 | 9142 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9143 | |
05cbaa28 | 9144 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9145 | /* |
9146 | * Mark the child context as a clone of the parent | |
9147 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9148 | * |
9149 | * Note that if the parent is a clone, the holding of | |
9150 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9151 | */ |
c5ed5145 | 9152 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9153 | if (cloned_ctx) { |
9154 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9155 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9156 | } else { |
9157 | child_ctx->parent_ctx = parent_ctx; | |
9158 | child_ctx->parent_gen = parent_ctx->generation; | |
9159 | } | |
9160 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9161 | } |
9162 | ||
c5ed5145 | 9163 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9164 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9165 | |
25346b93 | 9166 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9167 | put_ctx(parent_ctx); |
ad3a37de | 9168 | |
6ab423e0 | 9169 | return ret; |
9b51f66d IM |
9170 | } |
9171 | ||
8dc85d54 PZ |
9172 | /* |
9173 | * Initialize the perf_event context in task_struct | |
9174 | */ | |
9175 | int perf_event_init_task(struct task_struct *child) | |
9176 | { | |
9177 | int ctxn, ret; | |
9178 | ||
8550d7cb ON |
9179 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9180 | mutex_init(&child->perf_event_mutex); | |
9181 | INIT_LIST_HEAD(&child->perf_event_list); | |
9182 | ||
8dc85d54 PZ |
9183 | for_each_task_context_nr(ctxn) { |
9184 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9185 | if (ret) { |
9186 | perf_event_free_task(child); | |
8dc85d54 | 9187 | return ret; |
6c72e350 | 9188 | } |
8dc85d54 PZ |
9189 | } |
9190 | ||
9191 | return 0; | |
9192 | } | |
9193 | ||
220b140b PM |
9194 | static void __init perf_event_init_all_cpus(void) |
9195 | { | |
b28ab83c | 9196 | struct swevent_htable *swhash; |
220b140b | 9197 | int cpu; |
220b140b PM |
9198 | |
9199 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9200 | swhash = &per_cpu(swevent_htable, cpu); |
9201 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9202 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9203 | } |
9204 | } | |
9205 | ||
0db0628d | 9206 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9207 | { |
108b02cf | 9208 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9209 | |
b28ab83c | 9210 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9211 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9212 | struct swevent_hlist *hlist; |
9213 | ||
b28ab83c PZ |
9214 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9215 | WARN_ON(!hlist); | |
9216 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9217 | } |
b28ab83c | 9218 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9219 | } |
9220 | ||
2965faa5 | 9221 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9222 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9223 | { |
226424ee | 9224 | struct remove_event re = { .detach_group = true }; |
108b02cf | 9225 | struct perf_event_context *ctx = __info; |
0793a61d | 9226 | |
e3703f8c | 9227 | rcu_read_lock(); |
46ce0fe9 PZ |
9228 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) |
9229 | __perf_remove_from_context(&re); | |
e3703f8c | 9230 | rcu_read_unlock(); |
0793a61d | 9231 | } |
108b02cf PZ |
9232 | |
9233 | static void perf_event_exit_cpu_context(int cpu) | |
9234 | { | |
9235 | struct perf_event_context *ctx; | |
9236 | struct pmu *pmu; | |
9237 | int idx; | |
9238 | ||
9239 | idx = srcu_read_lock(&pmus_srcu); | |
9240 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9241 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9242 | |
9243 | mutex_lock(&ctx->mutex); | |
9244 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9245 | mutex_unlock(&ctx->mutex); | |
9246 | } | |
9247 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9248 | } |
9249 | ||
cdd6c482 | 9250 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9251 | { |
e3703f8c | 9252 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9253 | } |
9254 | #else | |
cdd6c482 | 9255 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9256 | #endif |
9257 | ||
c277443c PZ |
9258 | static int |
9259 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9260 | { | |
9261 | int cpu; | |
9262 | ||
9263 | for_each_online_cpu(cpu) | |
9264 | perf_event_exit_cpu(cpu); | |
9265 | ||
9266 | return NOTIFY_OK; | |
9267 | } | |
9268 | ||
9269 | /* | |
9270 | * Run the perf reboot notifier at the very last possible moment so that | |
9271 | * the generic watchdog code runs as long as possible. | |
9272 | */ | |
9273 | static struct notifier_block perf_reboot_notifier = { | |
9274 | .notifier_call = perf_reboot, | |
9275 | .priority = INT_MIN, | |
9276 | }; | |
9277 | ||
0db0628d | 9278 | static int |
0793a61d TG |
9279 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9280 | { | |
9281 | unsigned int cpu = (long)hcpu; | |
9282 | ||
4536e4d1 | 9283 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9284 | |
9285 | case CPU_UP_PREPARE: | |
5e11637e | 9286 | case CPU_DOWN_FAILED: |
cdd6c482 | 9287 | perf_event_init_cpu(cpu); |
0793a61d TG |
9288 | break; |
9289 | ||
5e11637e | 9290 | case CPU_UP_CANCELED: |
0793a61d | 9291 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9292 | perf_event_exit_cpu(cpu); |
0793a61d | 9293 | break; |
0793a61d TG |
9294 | default: |
9295 | break; | |
9296 | } | |
9297 | ||
9298 | return NOTIFY_OK; | |
9299 | } | |
9300 | ||
cdd6c482 | 9301 | void __init perf_event_init(void) |
0793a61d | 9302 | { |
3c502e7a JW |
9303 | int ret; |
9304 | ||
2e80a82a PZ |
9305 | idr_init(&pmu_idr); |
9306 | ||
220b140b | 9307 | perf_event_init_all_cpus(); |
b0a873eb | 9308 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9309 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9310 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9311 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9312 | perf_tp_register(); |
9313 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9314 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9315 | |
9316 | ret = init_hw_breakpoint(); | |
9317 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9318 | |
9319 | /* do not patch jump label more than once per second */ | |
9320 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9321 | |
9322 | /* | |
9323 | * Build time assertion that we keep the data_head at the intended | |
9324 | * location. IOW, validation we got the __reserved[] size right. | |
9325 | */ | |
9326 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9327 | != 1024); | |
0793a61d | 9328 | } |
abe43400 | 9329 | |
fd979c01 CS |
9330 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9331 | char *page) | |
9332 | { | |
9333 | struct perf_pmu_events_attr *pmu_attr = | |
9334 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9335 | ||
9336 | if (pmu_attr->event_str) | |
9337 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9338 | ||
9339 | return 0; | |
9340 | } | |
9341 | ||
abe43400 PZ |
9342 | static int __init perf_event_sysfs_init(void) |
9343 | { | |
9344 | struct pmu *pmu; | |
9345 | int ret; | |
9346 | ||
9347 | mutex_lock(&pmus_lock); | |
9348 | ||
9349 | ret = bus_register(&pmu_bus); | |
9350 | if (ret) | |
9351 | goto unlock; | |
9352 | ||
9353 | list_for_each_entry(pmu, &pmus, entry) { | |
9354 | if (!pmu->name || pmu->type < 0) | |
9355 | continue; | |
9356 | ||
9357 | ret = pmu_dev_alloc(pmu); | |
9358 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9359 | } | |
9360 | pmu_bus_running = 1; | |
9361 | ret = 0; | |
9362 | ||
9363 | unlock: | |
9364 | mutex_unlock(&pmus_lock); | |
9365 | ||
9366 | return ret; | |
9367 | } | |
9368 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9369 | |
9370 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9371 | static struct cgroup_subsys_state * |
9372 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9373 | { |
9374 | struct perf_cgroup *jc; | |
e5d1367f | 9375 | |
1b15d055 | 9376 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9377 | if (!jc) |
9378 | return ERR_PTR(-ENOMEM); | |
9379 | ||
e5d1367f SE |
9380 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9381 | if (!jc->info) { | |
9382 | kfree(jc); | |
9383 | return ERR_PTR(-ENOMEM); | |
9384 | } | |
9385 | ||
e5d1367f SE |
9386 | return &jc->css; |
9387 | } | |
9388 | ||
eb95419b | 9389 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9390 | { |
eb95419b TH |
9391 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9392 | ||
e5d1367f SE |
9393 | free_percpu(jc->info); |
9394 | kfree(jc); | |
9395 | } | |
9396 | ||
9397 | static int __perf_cgroup_move(void *info) | |
9398 | { | |
9399 | struct task_struct *task = info; | |
ddaaf4e2 | 9400 | rcu_read_lock(); |
e5d1367f | 9401 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9402 | rcu_read_unlock(); |
e5d1367f SE |
9403 | return 0; |
9404 | } | |
9405 | ||
1f7dd3e5 | 9406 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9407 | { |
bb9d97b6 | 9408 | struct task_struct *task; |
1f7dd3e5 | 9409 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9410 | |
1f7dd3e5 | 9411 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9412 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9413 | } |
9414 | ||
073219e9 | 9415 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9416 | .css_alloc = perf_cgroup_css_alloc, |
9417 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9418 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9419 | }; |
9420 | #endif /* CONFIG_CGROUP_PERF */ |