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 | { |
c994d613 PZ |
1249 | lockdep_assert_held(&ctx->lock); |
1250 | ||
8a49542c PZ |
1251 | WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); |
1252 | event->attach_state |= PERF_ATTACH_CONTEXT; | |
04289bb9 IM |
1253 | |
1254 | /* | |
8a49542c PZ |
1255 | * If we're a stand alone event or group leader, we go to the context |
1256 | * list, group events are kept attached to the group so that | |
1257 | * perf_group_detach can, at all times, locate all siblings. | |
04289bb9 | 1258 | */ |
8a49542c | 1259 | if (event->group_leader == event) { |
889ff015 FW |
1260 | struct list_head *list; |
1261 | ||
d6f962b5 FW |
1262 | if (is_software_event(event)) |
1263 | event->group_flags |= PERF_GROUP_SOFTWARE; | |
1264 | ||
889ff015 FW |
1265 | list = ctx_group_list(event, ctx); |
1266 | list_add_tail(&event->group_entry, list); | |
5c148194 | 1267 | } |
592903cd | 1268 | |
08309379 | 1269 | if (is_cgroup_event(event)) |
e5d1367f | 1270 | ctx->nr_cgroups++; |
e5d1367f | 1271 | |
cdd6c482 IM |
1272 | list_add_rcu(&event->event_entry, &ctx->event_list); |
1273 | ctx->nr_events++; | |
1274 | if (event->attr.inherit_stat) | |
bfbd3381 | 1275 | ctx->nr_stat++; |
5a3126d4 PZ |
1276 | |
1277 | ctx->generation++; | |
04289bb9 IM |
1278 | } |
1279 | ||
0231bb53 JO |
1280 | /* |
1281 | * Initialize event state based on the perf_event_attr::disabled. | |
1282 | */ | |
1283 | static inline void perf_event__state_init(struct perf_event *event) | |
1284 | { | |
1285 | event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : | |
1286 | PERF_EVENT_STATE_INACTIVE; | |
1287 | } | |
1288 | ||
a723968c | 1289 | static void __perf_event_read_size(struct perf_event *event, int nr_siblings) |
c320c7b7 ACM |
1290 | { |
1291 | int entry = sizeof(u64); /* value */ | |
1292 | int size = 0; | |
1293 | int nr = 1; | |
1294 | ||
1295 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
1296 | size += sizeof(u64); | |
1297 | ||
1298 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
1299 | size += sizeof(u64); | |
1300 | ||
1301 | if (event->attr.read_format & PERF_FORMAT_ID) | |
1302 | entry += sizeof(u64); | |
1303 | ||
1304 | if (event->attr.read_format & PERF_FORMAT_GROUP) { | |
a723968c | 1305 | nr += nr_siblings; |
c320c7b7 ACM |
1306 | size += sizeof(u64); |
1307 | } | |
1308 | ||
1309 | size += entry * nr; | |
1310 | event->read_size = size; | |
1311 | } | |
1312 | ||
a723968c | 1313 | static void __perf_event_header_size(struct perf_event *event, u64 sample_type) |
c320c7b7 ACM |
1314 | { |
1315 | struct perf_sample_data *data; | |
c320c7b7 ACM |
1316 | u16 size = 0; |
1317 | ||
c320c7b7 ACM |
1318 | if (sample_type & PERF_SAMPLE_IP) |
1319 | size += sizeof(data->ip); | |
1320 | ||
6844c09d ACM |
1321 | if (sample_type & PERF_SAMPLE_ADDR) |
1322 | size += sizeof(data->addr); | |
1323 | ||
1324 | if (sample_type & PERF_SAMPLE_PERIOD) | |
1325 | size += sizeof(data->period); | |
1326 | ||
c3feedf2 AK |
1327 | if (sample_type & PERF_SAMPLE_WEIGHT) |
1328 | size += sizeof(data->weight); | |
1329 | ||
6844c09d ACM |
1330 | if (sample_type & PERF_SAMPLE_READ) |
1331 | size += event->read_size; | |
1332 | ||
d6be9ad6 SE |
1333 | if (sample_type & PERF_SAMPLE_DATA_SRC) |
1334 | size += sizeof(data->data_src.val); | |
1335 | ||
fdfbbd07 AK |
1336 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
1337 | size += sizeof(data->txn); | |
1338 | ||
6844c09d ACM |
1339 | event->header_size = size; |
1340 | } | |
1341 | ||
a723968c PZ |
1342 | /* |
1343 | * Called at perf_event creation and when events are attached/detached from a | |
1344 | * group. | |
1345 | */ | |
1346 | static void perf_event__header_size(struct perf_event *event) | |
1347 | { | |
1348 | __perf_event_read_size(event, | |
1349 | event->group_leader->nr_siblings); | |
1350 | __perf_event_header_size(event, event->attr.sample_type); | |
1351 | } | |
1352 | ||
6844c09d ACM |
1353 | static void perf_event__id_header_size(struct perf_event *event) |
1354 | { | |
1355 | struct perf_sample_data *data; | |
1356 | u64 sample_type = event->attr.sample_type; | |
1357 | u16 size = 0; | |
1358 | ||
c320c7b7 ACM |
1359 | if (sample_type & PERF_SAMPLE_TID) |
1360 | size += sizeof(data->tid_entry); | |
1361 | ||
1362 | if (sample_type & PERF_SAMPLE_TIME) | |
1363 | size += sizeof(data->time); | |
1364 | ||
ff3d527c AH |
1365 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
1366 | size += sizeof(data->id); | |
1367 | ||
c320c7b7 ACM |
1368 | if (sample_type & PERF_SAMPLE_ID) |
1369 | size += sizeof(data->id); | |
1370 | ||
1371 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
1372 | size += sizeof(data->stream_id); | |
1373 | ||
1374 | if (sample_type & PERF_SAMPLE_CPU) | |
1375 | size += sizeof(data->cpu_entry); | |
1376 | ||
6844c09d | 1377 | event->id_header_size = size; |
c320c7b7 ACM |
1378 | } |
1379 | ||
a723968c PZ |
1380 | static bool perf_event_validate_size(struct perf_event *event) |
1381 | { | |
1382 | /* | |
1383 | * The values computed here will be over-written when we actually | |
1384 | * attach the event. | |
1385 | */ | |
1386 | __perf_event_read_size(event, event->group_leader->nr_siblings + 1); | |
1387 | __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ); | |
1388 | perf_event__id_header_size(event); | |
1389 | ||
1390 | /* | |
1391 | * Sum the lot; should not exceed the 64k limit we have on records. | |
1392 | * Conservative limit to allow for callchains and other variable fields. | |
1393 | */ | |
1394 | if (event->read_size + event->header_size + | |
1395 | event->id_header_size + sizeof(struct perf_event_header) >= 16*1024) | |
1396 | return false; | |
1397 | ||
1398 | return true; | |
1399 | } | |
1400 | ||
8a49542c PZ |
1401 | static void perf_group_attach(struct perf_event *event) |
1402 | { | |
c320c7b7 | 1403 | struct perf_event *group_leader = event->group_leader, *pos; |
8a49542c | 1404 | |
74c3337c PZ |
1405 | /* |
1406 | * We can have double attach due to group movement in perf_event_open. | |
1407 | */ | |
1408 | if (event->attach_state & PERF_ATTACH_GROUP) | |
1409 | return; | |
1410 | ||
8a49542c PZ |
1411 | event->attach_state |= PERF_ATTACH_GROUP; |
1412 | ||
1413 | if (group_leader == event) | |
1414 | return; | |
1415 | ||
652884fe PZ |
1416 | WARN_ON_ONCE(group_leader->ctx != event->ctx); |
1417 | ||
8a49542c PZ |
1418 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
1419 | !is_software_event(event)) | |
1420 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; | |
1421 | ||
1422 | list_add_tail(&event->group_entry, &group_leader->sibling_list); | |
1423 | group_leader->nr_siblings++; | |
c320c7b7 ACM |
1424 | |
1425 | perf_event__header_size(group_leader); | |
1426 | ||
1427 | list_for_each_entry(pos, &group_leader->sibling_list, group_entry) | |
1428 | perf_event__header_size(pos); | |
8a49542c PZ |
1429 | } |
1430 | ||
a63eaf34 | 1431 | /* |
cdd6c482 | 1432 | * Remove a event from the lists for its context. |
fccc714b | 1433 | * Must be called with ctx->mutex and ctx->lock held. |
a63eaf34 | 1434 | */ |
04289bb9 | 1435 | static void |
cdd6c482 | 1436 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
04289bb9 | 1437 | { |
68cacd29 | 1438 | struct perf_cpu_context *cpuctx; |
652884fe PZ |
1439 | |
1440 | WARN_ON_ONCE(event->ctx != ctx); | |
1441 | lockdep_assert_held(&ctx->lock); | |
1442 | ||
8a49542c PZ |
1443 | /* |
1444 | * We can have double detach due to exit/hot-unplug + close. | |
1445 | */ | |
1446 | if (!(event->attach_state & PERF_ATTACH_CONTEXT)) | |
a63eaf34 | 1447 | return; |
8a49542c PZ |
1448 | |
1449 | event->attach_state &= ~PERF_ATTACH_CONTEXT; | |
1450 | ||
68cacd29 | 1451 | if (is_cgroup_event(event)) { |
e5d1367f | 1452 | ctx->nr_cgroups--; |
68cacd29 SE |
1453 | cpuctx = __get_cpu_context(ctx); |
1454 | /* | |
1455 | * if there are no more cgroup events | |
1456 | * then cler cgrp to avoid stale pointer | |
1457 | * in update_cgrp_time_from_cpuctx() | |
1458 | */ | |
1459 | if (!ctx->nr_cgroups) | |
1460 | cpuctx->cgrp = NULL; | |
1461 | } | |
e5d1367f | 1462 | |
cdd6c482 IM |
1463 | ctx->nr_events--; |
1464 | if (event->attr.inherit_stat) | |
bfbd3381 | 1465 | ctx->nr_stat--; |
8bc20959 | 1466 | |
cdd6c482 | 1467 | list_del_rcu(&event->event_entry); |
04289bb9 | 1468 | |
8a49542c PZ |
1469 | if (event->group_leader == event) |
1470 | list_del_init(&event->group_entry); | |
5c148194 | 1471 | |
96c21a46 | 1472 | update_group_times(event); |
b2e74a26 SE |
1473 | |
1474 | /* | |
1475 | * If event was in error state, then keep it | |
1476 | * that way, otherwise bogus counts will be | |
1477 | * returned on read(). The only way to get out | |
1478 | * of error state is by explicit re-enabling | |
1479 | * of the event | |
1480 | */ | |
1481 | if (event->state > PERF_EVENT_STATE_OFF) | |
1482 | event->state = PERF_EVENT_STATE_OFF; | |
5a3126d4 PZ |
1483 | |
1484 | ctx->generation++; | |
050735b0 PZ |
1485 | } |
1486 | ||
8a49542c | 1487 | static void perf_group_detach(struct perf_event *event) |
050735b0 PZ |
1488 | { |
1489 | struct perf_event *sibling, *tmp; | |
8a49542c PZ |
1490 | struct list_head *list = NULL; |
1491 | ||
1492 | /* | |
1493 | * We can have double detach due to exit/hot-unplug + close. | |
1494 | */ | |
1495 | if (!(event->attach_state & PERF_ATTACH_GROUP)) | |
1496 | return; | |
1497 | ||
1498 | event->attach_state &= ~PERF_ATTACH_GROUP; | |
1499 | ||
1500 | /* | |
1501 | * If this is a sibling, remove it from its group. | |
1502 | */ | |
1503 | if (event->group_leader != event) { | |
1504 | list_del_init(&event->group_entry); | |
1505 | event->group_leader->nr_siblings--; | |
c320c7b7 | 1506 | goto out; |
8a49542c PZ |
1507 | } |
1508 | ||
1509 | if (!list_empty(&event->group_entry)) | |
1510 | list = &event->group_entry; | |
2e2af50b | 1511 | |
04289bb9 | 1512 | /* |
cdd6c482 IM |
1513 | * If this was a group event with sibling events then |
1514 | * upgrade the siblings to singleton events by adding them | |
8a49542c | 1515 | * to whatever list we are on. |
04289bb9 | 1516 | */ |
cdd6c482 | 1517 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
8a49542c PZ |
1518 | if (list) |
1519 | list_move_tail(&sibling->group_entry, list); | |
04289bb9 | 1520 | sibling->group_leader = sibling; |
d6f962b5 FW |
1521 | |
1522 | /* Inherit group flags from the previous leader */ | |
1523 | sibling->group_flags = event->group_flags; | |
652884fe PZ |
1524 | |
1525 | WARN_ON_ONCE(sibling->ctx != event->ctx); | |
04289bb9 | 1526 | } |
c320c7b7 ACM |
1527 | |
1528 | out: | |
1529 | perf_event__header_size(event->group_leader); | |
1530 | ||
1531 | list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry) | |
1532 | perf_event__header_size(tmp); | |
04289bb9 IM |
1533 | } |
1534 | ||
fadfe7be JO |
1535 | /* |
1536 | * User event without the task. | |
1537 | */ | |
1538 | static bool is_orphaned_event(struct perf_event *event) | |
1539 | { | |
1540 | return event && !is_kernel_event(event) && !event->owner; | |
1541 | } | |
1542 | ||
1543 | /* | |
1544 | * Event has a parent but parent's task finished and it's | |
1545 | * alive only because of children holding refference. | |
1546 | */ | |
1547 | static bool is_orphaned_child(struct perf_event *event) | |
1548 | { | |
1549 | return is_orphaned_event(event->parent); | |
1550 | } | |
1551 | ||
1552 | static void orphans_remove_work(struct work_struct *work); | |
1553 | ||
1554 | static void schedule_orphans_remove(struct perf_event_context *ctx) | |
1555 | { | |
1556 | if (!ctx->task || ctx->orphans_remove_sched || !perf_wq) | |
1557 | return; | |
1558 | ||
1559 | if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) { | |
1560 | get_ctx(ctx); | |
1561 | ctx->orphans_remove_sched = true; | |
1562 | } | |
1563 | } | |
1564 | ||
1565 | static int __init perf_workqueue_init(void) | |
1566 | { | |
1567 | perf_wq = create_singlethread_workqueue("perf"); | |
1568 | WARN(!perf_wq, "failed to create perf workqueue\n"); | |
1569 | return perf_wq ? 0 : -1; | |
1570 | } | |
1571 | ||
1572 | core_initcall(perf_workqueue_init); | |
1573 | ||
66eb579e MR |
1574 | static inline int pmu_filter_match(struct perf_event *event) |
1575 | { | |
1576 | struct pmu *pmu = event->pmu; | |
1577 | return pmu->filter_match ? pmu->filter_match(event) : 1; | |
1578 | } | |
1579 | ||
fa66f07a SE |
1580 | static inline int |
1581 | event_filter_match(struct perf_event *event) | |
1582 | { | |
e5d1367f | 1583 | return (event->cpu == -1 || event->cpu == smp_processor_id()) |
66eb579e | 1584 | && perf_cgroup_match(event) && pmu_filter_match(event); |
fa66f07a SE |
1585 | } |
1586 | ||
9ffcfa6f SE |
1587 | static void |
1588 | event_sched_out(struct perf_event *event, | |
3b6f9e5c | 1589 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1590 | struct perf_event_context *ctx) |
3b6f9e5c | 1591 | { |
4158755d | 1592 | u64 tstamp = perf_event_time(event); |
fa66f07a | 1593 | u64 delta; |
652884fe PZ |
1594 | |
1595 | WARN_ON_ONCE(event->ctx != ctx); | |
1596 | lockdep_assert_held(&ctx->lock); | |
1597 | ||
fa66f07a SE |
1598 | /* |
1599 | * An event which could not be activated because of | |
1600 | * filter mismatch still needs to have its timings | |
1601 | * maintained, otherwise bogus information is return | |
1602 | * via read() for time_enabled, time_running: | |
1603 | */ | |
1604 | if (event->state == PERF_EVENT_STATE_INACTIVE | |
1605 | && !event_filter_match(event)) { | |
e5d1367f | 1606 | delta = tstamp - event->tstamp_stopped; |
fa66f07a | 1607 | event->tstamp_running += delta; |
4158755d | 1608 | event->tstamp_stopped = tstamp; |
fa66f07a SE |
1609 | } |
1610 | ||
cdd6c482 | 1611 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
9ffcfa6f | 1612 | return; |
3b6f9e5c | 1613 | |
44377277 AS |
1614 | perf_pmu_disable(event->pmu); |
1615 | ||
cdd6c482 IM |
1616 | event->state = PERF_EVENT_STATE_INACTIVE; |
1617 | if (event->pending_disable) { | |
1618 | event->pending_disable = 0; | |
1619 | event->state = PERF_EVENT_STATE_OFF; | |
970892a9 | 1620 | } |
4158755d | 1621 | event->tstamp_stopped = tstamp; |
a4eaf7f1 | 1622 | event->pmu->del(event, 0); |
cdd6c482 | 1623 | event->oncpu = -1; |
3b6f9e5c | 1624 | |
cdd6c482 | 1625 | if (!is_software_event(event)) |
3b6f9e5c | 1626 | cpuctx->active_oncpu--; |
2fde4f94 MR |
1627 | if (!--ctx->nr_active) |
1628 | perf_event_ctx_deactivate(ctx); | |
0f5a2601 PZ |
1629 | if (event->attr.freq && event->attr.sample_freq) |
1630 | ctx->nr_freq--; | |
cdd6c482 | 1631 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
3b6f9e5c | 1632 | cpuctx->exclusive = 0; |
44377277 | 1633 | |
fadfe7be JO |
1634 | if (is_orphaned_child(event)) |
1635 | schedule_orphans_remove(ctx); | |
1636 | ||
44377277 | 1637 | perf_pmu_enable(event->pmu); |
3b6f9e5c PM |
1638 | } |
1639 | ||
d859e29f | 1640 | static void |
cdd6c482 | 1641 | group_sched_out(struct perf_event *group_event, |
d859e29f | 1642 | struct perf_cpu_context *cpuctx, |
cdd6c482 | 1643 | struct perf_event_context *ctx) |
d859e29f | 1644 | { |
cdd6c482 | 1645 | struct perf_event *event; |
fa66f07a | 1646 | int state = group_event->state; |
d859e29f | 1647 | |
cdd6c482 | 1648 | event_sched_out(group_event, cpuctx, ctx); |
d859e29f PM |
1649 | |
1650 | /* | |
1651 | * Schedule out siblings (if any): | |
1652 | */ | |
cdd6c482 IM |
1653 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
1654 | event_sched_out(event, cpuctx, ctx); | |
d859e29f | 1655 | |
fa66f07a | 1656 | if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) |
d859e29f PM |
1657 | cpuctx->exclusive = 0; |
1658 | } | |
1659 | ||
46ce0fe9 PZ |
1660 | struct remove_event { |
1661 | struct perf_event *event; | |
1662 | bool detach_group; | |
1663 | }; | |
1664 | ||
0017960f PZ |
1665 | static void ___perf_remove_from_context(void *info) |
1666 | { | |
1667 | struct remove_event *re = info; | |
1668 | struct perf_event *event = re->event; | |
1669 | struct perf_event_context *ctx = event->ctx; | |
1670 | ||
1671 | if (re->detach_group) | |
1672 | perf_group_detach(event); | |
1673 | list_del_event(event, ctx); | |
1674 | } | |
1675 | ||
0793a61d | 1676 | /* |
cdd6c482 | 1677 | * Cross CPU call to remove a performance event |
0793a61d | 1678 | * |
cdd6c482 | 1679 | * We disable the event on the hardware level first. After that we |
0793a61d TG |
1680 | * remove it from the context list. |
1681 | */ | |
fe4b04fa | 1682 | static int __perf_remove_from_context(void *info) |
0793a61d | 1683 | { |
46ce0fe9 PZ |
1684 | struct remove_event *re = info; |
1685 | struct perf_event *event = re->event; | |
cdd6c482 | 1686 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1687 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
0793a61d | 1688 | |
e625cce1 | 1689 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 1690 | event_sched_out(event, cpuctx, ctx); |
46ce0fe9 PZ |
1691 | if (re->detach_group) |
1692 | perf_group_detach(event); | |
cdd6c482 | 1693 | list_del_event(event, ctx); |
64ce3126 PZ |
1694 | if (!ctx->nr_events && cpuctx->task_ctx == ctx) { |
1695 | ctx->is_active = 0; | |
1696 | cpuctx->task_ctx = NULL; | |
1697 | } | |
e625cce1 | 1698 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1699 | |
1700 | return 0; | |
0793a61d TG |
1701 | } |
1702 | ||
0793a61d | 1703 | /* |
cdd6c482 | 1704 | * Remove the event from a task's (or a CPU's) list of events. |
0793a61d | 1705 | * |
cdd6c482 | 1706 | * CPU events are removed with a smp call. For task events we only |
0793a61d | 1707 | * call when the task is on a CPU. |
c93f7669 | 1708 | * |
cdd6c482 IM |
1709 | * If event->ctx is a cloned context, callers must make sure that |
1710 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 PM |
1711 | * remains valid. This is OK when called from perf_release since |
1712 | * that only calls us on the top-level context, which can't be a clone. | |
cdd6c482 | 1713 | * When called from perf_event_exit_task, it's OK because the |
c93f7669 | 1714 | * context has been detached from its task. |
0793a61d | 1715 | */ |
46ce0fe9 | 1716 | static void perf_remove_from_context(struct perf_event *event, bool detach_group) |
0793a61d | 1717 | { |
cdd6c482 | 1718 | struct perf_event_context *ctx = event->ctx; |
46ce0fe9 PZ |
1719 | struct remove_event re = { |
1720 | .event = event, | |
1721 | .detach_group = detach_group, | |
1722 | }; | |
0793a61d | 1723 | |
fe4b04fa PZ |
1724 | lockdep_assert_held(&ctx->mutex); |
1725 | ||
0017960f PZ |
1726 | event_function_call(event, __perf_remove_from_context, |
1727 | ___perf_remove_from_context, &re); | |
0793a61d TG |
1728 | } |
1729 | ||
d859e29f | 1730 | /* |
cdd6c482 | 1731 | * Cross CPU call to disable a performance event |
d859e29f | 1732 | */ |
500ad2d8 | 1733 | int __perf_event_disable(void *info) |
d859e29f | 1734 | { |
cdd6c482 | 1735 | struct perf_event *event = info; |
cdd6c482 | 1736 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 1737 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f PM |
1738 | |
1739 | /* | |
cdd6c482 IM |
1740 | * If this is a per-task event, need to check whether this |
1741 | * event's task is the current task on this cpu. | |
fe4b04fa PZ |
1742 | * |
1743 | * Can trigger due to concurrent perf_event_context_sched_out() | |
1744 | * flipping contexts around. | |
d859e29f | 1745 | */ |
665c2142 | 1746 | if (ctx->task && cpuctx->task_ctx != ctx) |
fe4b04fa | 1747 | return -EINVAL; |
d859e29f | 1748 | |
e625cce1 | 1749 | raw_spin_lock(&ctx->lock); |
d859e29f PM |
1750 | |
1751 | /* | |
cdd6c482 | 1752 | * If the event is on, turn it off. |
d859e29f PM |
1753 | * If it is in error state, leave it in error state. |
1754 | */ | |
cdd6c482 | 1755 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
4af4998b | 1756 | update_context_time(ctx); |
e5d1367f | 1757 | update_cgrp_time_from_event(event); |
cdd6c482 IM |
1758 | update_group_times(event); |
1759 | if (event == event->group_leader) | |
1760 | group_sched_out(event, cpuctx, ctx); | |
d859e29f | 1761 | else |
cdd6c482 IM |
1762 | event_sched_out(event, cpuctx, ctx); |
1763 | event->state = PERF_EVENT_STATE_OFF; | |
d859e29f PM |
1764 | } |
1765 | ||
e625cce1 | 1766 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
1767 | |
1768 | return 0; | |
d859e29f PM |
1769 | } |
1770 | ||
7b648018 PZ |
1771 | void ___perf_event_disable(void *info) |
1772 | { | |
1773 | struct perf_event *event = info; | |
1774 | ||
1775 | /* | |
1776 | * Since we have the lock this context can't be scheduled | |
1777 | * in, so we can change the state safely. | |
1778 | */ | |
1779 | if (event->state == PERF_EVENT_STATE_INACTIVE) { | |
1780 | update_group_times(event); | |
1781 | event->state = PERF_EVENT_STATE_OFF; | |
1782 | } | |
1783 | } | |
1784 | ||
d859e29f | 1785 | /* |
cdd6c482 | 1786 | * Disable a event. |
c93f7669 | 1787 | * |
cdd6c482 IM |
1788 | * If event->ctx is a cloned context, callers must make sure that |
1789 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 1790 | * remains valid. This condition is satisifed when called through |
cdd6c482 IM |
1791 | * perf_event_for_each_child or perf_event_for_each because they |
1792 | * hold the top-level event's child_mutex, so any descendant that | |
1793 | * goes to exit will block in sync_child_event. | |
1794 | * When called from perf_pending_event it's OK because event->ctx | |
c93f7669 | 1795 | * is the current context on this CPU and preemption is disabled, |
cdd6c482 | 1796 | * hence we can't get into perf_event_task_sched_out for this context. |
d859e29f | 1797 | */ |
f63a8daa | 1798 | static void _perf_event_disable(struct perf_event *event) |
d859e29f | 1799 | { |
cdd6c482 | 1800 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 1801 | |
e625cce1 | 1802 | raw_spin_lock_irq(&ctx->lock); |
7b648018 | 1803 | if (event->state <= PERF_EVENT_STATE_OFF) { |
e625cce1 | 1804 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 | 1805 | return; |
53cfbf59 | 1806 | } |
e625cce1 | 1807 | raw_spin_unlock_irq(&ctx->lock); |
7b648018 PZ |
1808 | |
1809 | event_function_call(event, __perf_event_disable, | |
1810 | ___perf_event_disable, event); | |
d859e29f | 1811 | } |
f63a8daa PZ |
1812 | |
1813 | /* | |
1814 | * Strictly speaking kernel users cannot create groups and therefore this | |
1815 | * interface does not need the perf_event_ctx_lock() magic. | |
1816 | */ | |
1817 | void perf_event_disable(struct perf_event *event) | |
1818 | { | |
1819 | struct perf_event_context *ctx; | |
1820 | ||
1821 | ctx = perf_event_ctx_lock(event); | |
1822 | _perf_event_disable(event); | |
1823 | perf_event_ctx_unlock(event, ctx); | |
1824 | } | |
dcfce4a0 | 1825 | EXPORT_SYMBOL_GPL(perf_event_disable); |
d859e29f | 1826 | |
e5d1367f SE |
1827 | static void perf_set_shadow_time(struct perf_event *event, |
1828 | struct perf_event_context *ctx, | |
1829 | u64 tstamp) | |
1830 | { | |
1831 | /* | |
1832 | * use the correct time source for the time snapshot | |
1833 | * | |
1834 | * We could get by without this by leveraging the | |
1835 | * fact that to get to this function, the caller | |
1836 | * has most likely already called update_context_time() | |
1837 | * and update_cgrp_time_xx() and thus both timestamp | |
1838 | * are identical (or very close). Given that tstamp is, | |
1839 | * already adjusted for cgroup, we could say that: | |
1840 | * tstamp - ctx->timestamp | |
1841 | * is equivalent to | |
1842 | * tstamp - cgrp->timestamp. | |
1843 | * | |
1844 | * Then, in perf_output_read(), the calculation would | |
1845 | * work with no changes because: | |
1846 | * - event is guaranteed scheduled in | |
1847 | * - no scheduled out in between | |
1848 | * - thus the timestamp would be the same | |
1849 | * | |
1850 | * But this is a bit hairy. | |
1851 | * | |
1852 | * So instead, we have an explicit cgroup call to remain | |
1853 | * within the time time source all along. We believe it | |
1854 | * is cleaner and simpler to understand. | |
1855 | */ | |
1856 | if (is_cgroup_event(event)) | |
1857 | perf_cgroup_set_shadow_time(event, tstamp); | |
1858 | else | |
1859 | event->shadow_ctx_time = tstamp - ctx->timestamp; | |
1860 | } | |
1861 | ||
4fe757dd PZ |
1862 | #define MAX_INTERRUPTS (~0ULL) |
1863 | ||
1864 | static void perf_log_throttle(struct perf_event *event, int enable); | |
ec0d7729 | 1865 | static void perf_log_itrace_start(struct perf_event *event); |
4fe757dd | 1866 | |
235c7fc7 | 1867 | static int |
9ffcfa6f | 1868 | event_sched_in(struct perf_event *event, |
235c7fc7 | 1869 | struct perf_cpu_context *cpuctx, |
6e37738a | 1870 | struct perf_event_context *ctx) |
235c7fc7 | 1871 | { |
4158755d | 1872 | u64 tstamp = perf_event_time(event); |
44377277 | 1873 | int ret = 0; |
4158755d | 1874 | |
63342411 PZ |
1875 | lockdep_assert_held(&ctx->lock); |
1876 | ||
cdd6c482 | 1877 | if (event->state <= PERF_EVENT_STATE_OFF) |
235c7fc7 IM |
1878 | return 0; |
1879 | ||
cdd6c482 | 1880 | event->state = PERF_EVENT_STATE_ACTIVE; |
6e37738a | 1881 | event->oncpu = smp_processor_id(); |
4fe757dd PZ |
1882 | |
1883 | /* | |
1884 | * Unthrottle events, since we scheduled we might have missed several | |
1885 | * ticks already, also for a heavily scheduling task there is little | |
1886 | * guarantee it'll get a tick in a timely manner. | |
1887 | */ | |
1888 | if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) { | |
1889 | perf_log_throttle(event, 1); | |
1890 | event->hw.interrupts = 0; | |
1891 | } | |
1892 | ||
235c7fc7 IM |
1893 | /* |
1894 | * The new state must be visible before we turn it on in the hardware: | |
1895 | */ | |
1896 | smp_wmb(); | |
1897 | ||
44377277 AS |
1898 | perf_pmu_disable(event->pmu); |
1899 | ||
72f669c0 SL |
1900 | perf_set_shadow_time(event, ctx, tstamp); |
1901 | ||
ec0d7729 AS |
1902 | perf_log_itrace_start(event); |
1903 | ||
a4eaf7f1 | 1904 | if (event->pmu->add(event, PERF_EF_START)) { |
cdd6c482 IM |
1905 | event->state = PERF_EVENT_STATE_INACTIVE; |
1906 | event->oncpu = -1; | |
44377277 AS |
1907 | ret = -EAGAIN; |
1908 | goto out; | |
235c7fc7 IM |
1909 | } |
1910 | ||
00a2916f PZ |
1911 | event->tstamp_running += tstamp - event->tstamp_stopped; |
1912 | ||
cdd6c482 | 1913 | if (!is_software_event(event)) |
3b6f9e5c | 1914 | cpuctx->active_oncpu++; |
2fde4f94 MR |
1915 | if (!ctx->nr_active++) |
1916 | perf_event_ctx_activate(ctx); | |
0f5a2601 PZ |
1917 | if (event->attr.freq && event->attr.sample_freq) |
1918 | ctx->nr_freq++; | |
235c7fc7 | 1919 | |
cdd6c482 | 1920 | if (event->attr.exclusive) |
3b6f9e5c PM |
1921 | cpuctx->exclusive = 1; |
1922 | ||
fadfe7be JO |
1923 | if (is_orphaned_child(event)) |
1924 | schedule_orphans_remove(ctx); | |
1925 | ||
44377277 AS |
1926 | out: |
1927 | perf_pmu_enable(event->pmu); | |
1928 | ||
1929 | return ret; | |
235c7fc7 IM |
1930 | } |
1931 | ||
6751b71e | 1932 | static int |
cdd6c482 | 1933 | group_sched_in(struct perf_event *group_event, |
6751b71e | 1934 | struct perf_cpu_context *cpuctx, |
6e37738a | 1935 | struct perf_event_context *ctx) |
6751b71e | 1936 | { |
6bde9b6c | 1937 | struct perf_event *event, *partial_group = NULL; |
4a234593 | 1938 | struct pmu *pmu = ctx->pmu; |
d7842da4 SE |
1939 | u64 now = ctx->time; |
1940 | bool simulate = false; | |
6751b71e | 1941 | |
cdd6c482 | 1942 | if (group_event->state == PERF_EVENT_STATE_OFF) |
6751b71e PM |
1943 | return 0; |
1944 | ||
fbbe0701 | 1945 | pmu->start_txn(pmu, PERF_PMU_TXN_ADD); |
6bde9b6c | 1946 | |
9ffcfa6f | 1947 | if (event_sched_in(group_event, cpuctx, ctx)) { |
ad5133b7 | 1948 | pmu->cancel_txn(pmu); |
272325c4 | 1949 | perf_mux_hrtimer_restart(cpuctx); |
6751b71e | 1950 | return -EAGAIN; |
90151c35 | 1951 | } |
6751b71e PM |
1952 | |
1953 | /* | |
1954 | * Schedule in siblings as one group (if any): | |
1955 | */ | |
cdd6c482 | 1956 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
9ffcfa6f | 1957 | if (event_sched_in(event, cpuctx, ctx)) { |
cdd6c482 | 1958 | partial_group = event; |
6751b71e PM |
1959 | goto group_error; |
1960 | } | |
1961 | } | |
1962 | ||
9ffcfa6f | 1963 | if (!pmu->commit_txn(pmu)) |
6e85158c | 1964 | return 0; |
9ffcfa6f | 1965 | |
6751b71e PM |
1966 | group_error: |
1967 | /* | |
1968 | * Groups can be scheduled in as one unit only, so undo any | |
1969 | * partial group before returning: | |
d7842da4 SE |
1970 | * The events up to the failed event are scheduled out normally, |
1971 | * tstamp_stopped will be updated. | |
1972 | * | |
1973 | * The failed events and the remaining siblings need to have | |
1974 | * their timings updated as if they had gone thru event_sched_in() | |
1975 | * and event_sched_out(). This is required to get consistent timings | |
1976 | * across the group. This also takes care of the case where the group | |
1977 | * could never be scheduled by ensuring tstamp_stopped is set to mark | |
1978 | * the time the event was actually stopped, such that time delta | |
1979 | * calculation in update_event_times() is correct. | |
6751b71e | 1980 | */ |
cdd6c482 IM |
1981 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
1982 | if (event == partial_group) | |
d7842da4 SE |
1983 | simulate = true; |
1984 | ||
1985 | if (simulate) { | |
1986 | event->tstamp_running += now - event->tstamp_stopped; | |
1987 | event->tstamp_stopped = now; | |
1988 | } else { | |
1989 | event_sched_out(event, cpuctx, ctx); | |
1990 | } | |
6751b71e | 1991 | } |
9ffcfa6f | 1992 | event_sched_out(group_event, cpuctx, ctx); |
6751b71e | 1993 | |
ad5133b7 | 1994 | pmu->cancel_txn(pmu); |
90151c35 | 1995 | |
272325c4 | 1996 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 1997 | |
6751b71e PM |
1998 | return -EAGAIN; |
1999 | } | |
2000 | ||
3b6f9e5c | 2001 | /* |
cdd6c482 | 2002 | * Work out whether we can put this event group on the CPU now. |
3b6f9e5c | 2003 | */ |
cdd6c482 | 2004 | static int group_can_go_on(struct perf_event *event, |
3b6f9e5c PM |
2005 | struct perf_cpu_context *cpuctx, |
2006 | int can_add_hw) | |
2007 | { | |
2008 | /* | |
cdd6c482 | 2009 | * Groups consisting entirely of software events can always go on. |
3b6f9e5c | 2010 | */ |
d6f962b5 | 2011 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
3b6f9e5c PM |
2012 | return 1; |
2013 | /* | |
2014 | * If an exclusive group is already on, no other hardware | |
cdd6c482 | 2015 | * events can go on. |
3b6f9e5c PM |
2016 | */ |
2017 | if (cpuctx->exclusive) | |
2018 | return 0; | |
2019 | /* | |
2020 | * If this group is exclusive and there are already | |
cdd6c482 | 2021 | * events on the CPU, it can't go on. |
3b6f9e5c | 2022 | */ |
cdd6c482 | 2023 | if (event->attr.exclusive && cpuctx->active_oncpu) |
3b6f9e5c PM |
2024 | return 0; |
2025 | /* | |
2026 | * Otherwise, try to add it if all previous groups were able | |
2027 | * to go on. | |
2028 | */ | |
2029 | return can_add_hw; | |
2030 | } | |
2031 | ||
cdd6c482 IM |
2032 | static void add_event_to_ctx(struct perf_event *event, |
2033 | struct perf_event_context *ctx) | |
53cfbf59 | 2034 | { |
4158755d SE |
2035 | u64 tstamp = perf_event_time(event); |
2036 | ||
cdd6c482 | 2037 | list_add_event(event, ctx); |
8a49542c | 2038 | perf_group_attach(event); |
4158755d SE |
2039 | event->tstamp_enabled = tstamp; |
2040 | event->tstamp_running = tstamp; | |
2041 | event->tstamp_stopped = tstamp; | |
53cfbf59 PM |
2042 | } |
2043 | ||
2c29ef0f PZ |
2044 | static void task_ctx_sched_out(struct perf_event_context *ctx); |
2045 | static void | |
2046 | ctx_sched_in(struct perf_event_context *ctx, | |
2047 | struct perf_cpu_context *cpuctx, | |
2048 | enum event_type_t event_type, | |
2049 | struct task_struct *task); | |
fe4b04fa | 2050 | |
dce5855b PZ |
2051 | static void perf_event_sched_in(struct perf_cpu_context *cpuctx, |
2052 | struct perf_event_context *ctx, | |
2053 | struct task_struct *task) | |
2054 | { | |
2055 | cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task); | |
2056 | if (ctx) | |
2057 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task); | |
2058 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task); | |
2059 | if (ctx) | |
2060 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task); | |
2061 | } | |
2062 | ||
0017960f PZ |
2063 | static void ___perf_install_in_context(void *info) |
2064 | { | |
2065 | struct perf_event *event = info; | |
2066 | struct perf_event_context *ctx = event->ctx; | |
2067 | ||
2068 | /* | |
2069 | * Since the task isn't running, its safe to add the event, us holding | |
2070 | * the ctx->lock ensures the task won't get scheduled in. | |
2071 | */ | |
2072 | add_event_to_ctx(event, ctx); | |
2073 | } | |
2074 | ||
0793a61d | 2075 | /* |
cdd6c482 | 2076 | * Cross CPU call to install and enable a performance event |
682076ae PZ |
2077 | * |
2078 | * Must be called with ctx->mutex held | |
0793a61d | 2079 | */ |
fe4b04fa | 2080 | static int __perf_install_in_context(void *info) |
0793a61d | 2081 | { |
cdd6c482 IM |
2082 | struct perf_event *event = info; |
2083 | struct perf_event_context *ctx = event->ctx; | |
108b02cf | 2084 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
2c29ef0f PZ |
2085 | struct perf_event_context *task_ctx = cpuctx->task_ctx; |
2086 | struct task_struct *task = current; | |
2087 | ||
b58f6b0d | 2088 | perf_ctx_lock(cpuctx, task_ctx); |
2c29ef0f | 2089 | perf_pmu_disable(cpuctx->ctx.pmu); |
0793a61d TG |
2090 | |
2091 | /* | |
2c29ef0f | 2092 | * If there was an active task_ctx schedule it out. |
0793a61d | 2093 | */ |
b58f6b0d | 2094 | if (task_ctx) |
2c29ef0f | 2095 | task_ctx_sched_out(task_ctx); |
b58f6b0d PZ |
2096 | |
2097 | /* | |
2098 | * If the context we're installing events in is not the | |
2099 | * active task_ctx, flip them. | |
2100 | */ | |
2101 | if (ctx->task && task_ctx != ctx) { | |
2102 | if (task_ctx) | |
2103 | raw_spin_unlock(&task_ctx->lock); | |
2104 | raw_spin_lock(&ctx->lock); | |
2105 | task_ctx = ctx; | |
2106 | } | |
2107 | ||
2108 | if (task_ctx) { | |
2109 | cpuctx->task_ctx = task_ctx; | |
2c29ef0f PZ |
2110 | task = task_ctx->task; |
2111 | } | |
b58f6b0d | 2112 | |
2c29ef0f | 2113 | cpu_ctx_sched_out(cpuctx, EVENT_ALL); |
0793a61d | 2114 | |
4af4998b | 2115 | update_context_time(ctx); |
e5d1367f SE |
2116 | /* |
2117 | * update cgrp time only if current cgrp | |
2118 | * matches event->cgrp. Must be done before | |
2119 | * calling add_event_to_ctx() | |
2120 | */ | |
2121 | update_cgrp_time_from_event(event); | |
0793a61d | 2122 | |
cdd6c482 | 2123 | add_event_to_ctx(event, ctx); |
0793a61d | 2124 | |
d859e29f | 2125 | /* |
2c29ef0f | 2126 | * Schedule everything back in |
d859e29f | 2127 | */ |
dce5855b | 2128 | perf_event_sched_in(cpuctx, task_ctx, task); |
2c29ef0f PZ |
2129 | |
2130 | perf_pmu_enable(cpuctx->ctx.pmu); | |
2131 | perf_ctx_unlock(cpuctx, task_ctx); | |
fe4b04fa PZ |
2132 | |
2133 | return 0; | |
0793a61d TG |
2134 | } |
2135 | ||
2136 | /* | |
cdd6c482 | 2137 | * Attach a performance event to a context |
0793a61d | 2138 | * |
cdd6c482 IM |
2139 | * First we add the event to the list with the hardware enable bit |
2140 | * in event->hw_config cleared. | |
0793a61d | 2141 | * |
cdd6c482 | 2142 | * If the event is attached to a task which is on a CPU we use a smp |
0793a61d TG |
2143 | * call to enable it in the task context. The task might have been |
2144 | * scheduled away, but we check this in the smp call again. | |
2145 | */ | |
2146 | static void | |
cdd6c482 IM |
2147 | perf_install_in_context(struct perf_event_context *ctx, |
2148 | struct perf_event *event, | |
0793a61d TG |
2149 | int cpu) |
2150 | { | |
fe4b04fa PZ |
2151 | lockdep_assert_held(&ctx->mutex); |
2152 | ||
c3f00c70 | 2153 | event->ctx = ctx; |
0cda4c02 YZ |
2154 | if (event->cpu != -1) |
2155 | event->cpu = cpu; | |
c3f00c70 | 2156 | |
0017960f PZ |
2157 | event_function_call(event, __perf_install_in_context, |
2158 | ___perf_install_in_context, event); | |
0793a61d TG |
2159 | } |
2160 | ||
fa289bec | 2161 | /* |
cdd6c482 | 2162 | * Put a event into inactive state and update time fields. |
fa289bec PM |
2163 | * Enabling the leader of a group effectively enables all |
2164 | * the group members that aren't explicitly disabled, so we | |
2165 | * have to update their ->tstamp_enabled also. | |
2166 | * Note: this works for group members as well as group leaders | |
2167 | * since the non-leader members' sibling_lists will be empty. | |
2168 | */ | |
1d9b482e | 2169 | static void __perf_event_mark_enabled(struct perf_event *event) |
fa289bec | 2170 | { |
cdd6c482 | 2171 | struct perf_event *sub; |
4158755d | 2172 | u64 tstamp = perf_event_time(event); |
fa289bec | 2173 | |
cdd6c482 | 2174 | event->state = PERF_EVENT_STATE_INACTIVE; |
4158755d | 2175 | event->tstamp_enabled = tstamp - event->total_time_enabled; |
9ed6060d | 2176 | list_for_each_entry(sub, &event->sibling_list, group_entry) { |
4158755d SE |
2177 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
2178 | sub->tstamp_enabled = tstamp - sub->total_time_enabled; | |
9ed6060d | 2179 | } |
fa289bec PM |
2180 | } |
2181 | ||
d859e29f | 2182 | /* |
cdd6c482 | 2183 | * Cross CPU call to enable a performance event |
d859e29f | 2184 | */ |
fe4b04fa | 2185 | static int __perf_event_enable(void *info) |
04289bb9 | 2186 | { |
cdd6c482 | 2187 | struct perf_event *event = info; |
cdd6c482 IM |
2188 | struct perf_event_context *ctx = event->ctx; |
2189 | struct perf_event *leader = event->group_leader; | |
108b02cf | 2190 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
d859e29f | 2191 | int err; |
04289bb9 | 2192 | |
06f41796 JO |
2193 | /* |
2194 | * There's a time window between 'ctx->is_active' check | |
2195 | * in perf_event_enable function and this place having: | |
2196 | * - IRQs on | |
2197 | * - ctx->lock unlocked | |
2198 | * | |
2199 | * where the task could be killed and 'ctx' deactivated | |
2200 | * by perf_event_exit_task. | |
2201 | */ | |
2202 | if (!ctx->is_active) | |
fe4b04fa | 2203 | return -EINVAL; |
3cbed429 | 2204 | |
e625cce1 | 2205 | raw_spin_lock(&ctx->lock); |
4af4998b | 2206 | update_context_time(ctx); |
d859e29f | 2207 | |
cdd6c482 | 2208 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
d859e29f | 2209 | goto unlock; |
e5d1367f SE |
2210 | |
2211 | /* | |
2212 | * set current task's cgroup time reference point | |
2213 | */ | |
3f7cce3c | 2214 | perf_cgroup_set_timestamp(current, ctx); |
e5d1367f | 2215 | |
1d9b482e | 2216 | __perf_event_mark_enabled(event); |
04289bb9 | 2217 | |
e5d1367f SE |
2218 | if (!event_filter_match(event)) { |
2219 | if (is_cgroup_event(event)) | |
2220 | perf_cgroup_defer_enabled(event); | |
f4c4176f | 2221 | goto unlock; |
e5d1367f | 2222 | } |
f4c4176f | 2223 | |
04289bb9 | 2224 | /* |
cdd6c482 | 2225 | * If the event is in a group and isn't the group leader, |
d859e29f | 2226 | * then don't put it on unless the group is on. |
04289bb9 | 2227 | */ |
cdd6c482 | 2228 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
d859e29f | 2229 | goto unlock; |
3b6f9e5c | 2230 | |
cdd6c482 | 2231 | if (!group_can_go_on(event, cpuctx, 1)) { |
d859e29f | 2232 | err = -EEXIST; |
e758a33d | 2233 | } else { |
cdd6c482 | 2234 | if (event == leader) |
6e37738a | 2235 | err = group_sched_in(event, cpuctx, ctx); |
e758a33d | 2236 | else |
6e37738a | 2237 | err = event_sched_in(event, cpuctx, ctx); |
e758a33d | 2238 | } |
d859e29f PM |
2239 | |
2240 | if (err) { | |
2241 | /* | |
cdd6c482 | 2242 | * If this event can't go on and it's part of a |
d859e29f PM |
2243 | * group, then the whole group has to come off. |
2244 | */ | |
9e630205 | 2245 | if (leader != event) { |
d859e29f | 2246 | group_sched_out(leader, cpuctx, ctx); |
272325c4 | 2247 | perf_mux_hrtimer_restart(cpuctx); |
9e630205 | 2248 | } |
0d48696f | 2249 | if (leader->attr.pinned) { |
53cfbf59 | 2250 | update_group_times(leader); |
cdd6c482 | 2251 | leader->state = PERF_EVENT_STATE_ERROR; |
53cfbf59 | 2252 | } |
d859e29f PM |
2253 | } |
2254 | ||
9ed6060d | 2255 | unlock: |
e625cce1 | 2256 | raw_spin_unlock(&ctx->lock); |
fe4b04fa PZ |
2257 | |
2258 | return 0; | |
d859e29f PM |
2259 | } |
2260 | ||
7b648018 PZ |
2261 | void ___perf_event_enable(void *info) |
2262 | { | |
2263 | __perf_event_mark_enabled((struct perf_event *)info); | |
2264 | } | |
2265 | ||
d859e29f | 2266 | /* |
cdd6c482 | 2267 | * Enable a event. |
c93f7669 | 2268 | * |
cdd6c482 IM |
2269 | * If event->ctx is a cloned context, callers must make sure that |
2270 | * every task struct that event->ctx->task could possibly point to | |
c93f7669 | 2271 | * remains valid. This condition is satisfied when called through |
cdd6c482 IM |
2272 | * perf_event_for_each_child or perf_event_for_each as described |
2273 | * for perf_event_disable. | |
d859e29f | 2274 | */ |
f63a8daa | 2275 | static void _perf_event_enable(struct perf_event *event) |
d859e29f | 2276 | { |
cdd6c482 | 2277 | struct perf_event_context *ctx = event->ctx; |
d859e29f | 2278 | |
7b648018 PZ |
2279 | raw_spin_lock_irq(&ctx->lock); |
2280 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { | |
2281 | raw_spin_unlock_irq(&ctx->lock); | |
d859e29f PM |
2282 | return; |
2283 | } | |
2284 | ||
d859e29f | 2285 | /* |
cdd6c482 | 2286 | * If the event is in error state, clear that first. |
7b648018 PZ |
2287 | * |
2288 | * That way, if we see the event in error state below, we know that it | |
2289 | * has gone back into error state, as distinct from the task having | |
2290 | * been scheduled away before the cross-call arrived. | |
d859e29f | 2291 | */ |
cdd6c482 IM |
2292 | if (event->state == PERF_EVENT_STATE_ERROR) |
2293 | event->state = PERF_EVENT_STATE_OFF; | |
e625cce1 | 2294 | raw_spin_unlock_irq(&ctx->lock); |
fe4b04fa | 2295 | |
7b648018 PZ |
2296 | event_function_call(event, __perf_event_enable, |
2297 | ___perf_event_enable, event); | |
d859e29f | 2298 | } |
f63a8daa PZ |
2299 | |
2300 | /* | |
2301 | * See perf_event_disable(); | |
2302 | */ | |
2303 | void perf_event_enable(struct perf_event *event) | |
2304 | { | |
2305 | struct perf_event_context *ctx; | |
2306 | ||
2307 | ctx = perf_event_ctx_lock(event); | |
2308 | _perf_event_enable(event); | |
2309 | perf_event_ctx_unlock(event, ctx); | |
2310 | } | |
dcfce4a0 | 2311 | EXPORT_SYMBOL_GPL(perf_event_enable); |
d859e29f | 2312 | |
f63a8daa | 2313 | static int _perf_event_refresh(struct perf_event *event, int refresh) |
79f14641 | 2314 | { |
2023b359 | 2315 | /* |
cdd6c482 | 2316 | * not supported on inherited events |
2023b359 | 2317 | */ |
2e939d1d | 2318 | if (event->attr.inherit || !is_sampling_event(event)) |
2023b359 PZ |
2319 | return -EINVAL; |
2320 | ||
cdd6c482 | 2321 | atomic_add(refresh, &event->event_limit); |
f63a8daa | 2322 | _perf_event_enable(event); |
2023b359 PZ |
2323 | |
2324 | return 0; | |
79f14641 | 2325 | } |
f63a8daa PZ |
2326 | |
2327 | /* | |
2328 | * See perf_event_disable() | |
2329 | */ | |
2330 | int perf_event_refresh(struct perf_event *event, int refresh) | |
2331 | { | |
2332 | struct perf_event_context *ctx; | |
2333 | int ret; | |
2334 | ||
2335 | ctx = perf_event_ctx_lock(event); | |
2336 | ret = _perf_event_refresh(event, refresh); | |
2337 | perf_event_ctx_unlock(event, ctx); | |
2338 | ||
2339 | return ret; | |
2340 | } | |
26ca5c11 | 2341 | EXPORT_SYMBOL_GPL(perf_event_refresh); |
79f14641 | 2342 | |
5b0311e1 FW |
2343 | static void ctx_sched_out(struct perf_event_context *ctx, |
2344 | struct perf_cpu_context *cpuctx, | |
2345 | enum event_type_t event_type) | |
235c7fc7 | 2346 | { |
db24d33e | 2347 | int is_active = ctx->is_active; |
c994d613 PZ |
2348 | struct perf_event *event; |
2349 | ||
2350 | lockdep_assert_held(&ctx->lock); | |
235c7fc7 | 2351 | |
db24d33e | 2352 | ctx->is_active &= ~event_type; |
cdd6c482 | 2353 | if (likely(!ctx->nr_events)) |
facc4307 PZ |
2354 | return; |
2355 | ||
4af4998b | 2356 | update_context_time(ctx); |
e5d1367f | 2357 | update_cgrp_time_from_cpuctx(cpuctx); |
5b0311e1 | 2358 | if (!ctx->nr_active) |
facc4307 | 2359 | return; |
5b0311e1 | 2360 | |
075e0b00 | 2361 | perf_pmu_disable(ctx->pmu); |
db24d33e | 2362 | if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) { |
889ff015 FW |
2363 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
2364 | group_sched_out(event, cpuctx, ctx); | |
9ed6060d | 2365 | } |
889ff015 | 2366 | |
db24d33e | 2367 | if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) { |
889ff015 | 2368 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
8c9ed8e1 | 2369 | group_sched_out(event, cpuctx, ctx); |
9ed6060d | 2370 | } |
1b9a644f | 2371 | perf_pmu_enable(ctx->pmu); |
235c7fc7 IM |
2372 | } |
2373 | ||
564c2b21 | 2374 | /* |
5a3126d4 PZ |
2375 | * Test whether two contexts are equivalent, i.e. whether they have both been |
2376 | * cloned from the same version of the same context. | |
2377 | * | |
2378 | * Equivalence is measured using a generation number in the context that is | |
2379 | * incremented on each modification to it; see unclone_ctx(), list_add_event() | |
2380 | * and list_del_event(). | |
564c2b21 | 2381 | */ |
cdd6c482 IM |
2382 | static int context_equiv(struct perf_event_context *ctx1, |
2383 | struct perf_event_context *ctx2) | |
564c2b21 | 2384 | { |
211de6eb PZ |
2385 | lockdep_assert_held(&ctx1->lock); |
2386 | lockdep_assert_held(&ctx2->lock); | |
2387 | ||
5a3126d4 PZ |
2388 | /* Pinning disables the swap optimization */ |
2389 | if (ctx1->pin_count || ctx2->pin_count) | |
2390 | return 0; | |
2391 | ||
2392 | /* If ctx1 is the parent of ctx2 */ | |
2393 | if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) | |
2394 | return 1; | |
2395 | ||
2396 | /* If ctx2 is the parent of ctx1 */ | |
2397 | if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) | |
2398 | return 1; | |
2399 | ||
2400 | /* | |
2401 | * If ctx1 and ctx2 have the same parent; we flatten the parent | |
2402 | * hierarchy, see perf_event_init_context(). | |
2403 | */ | |
2404 | if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && | |
2405 | ctx1->parent_gen == ctx2->parent_gen) | |
2406 | return 1; | |
2407 | ||
2408 | /* Unmatched */ | |
2409 | return 0; | |
564c2b21 PM |
2410 | } |
2411 | ||
cdd6c482 IM |
2412 | static void __perf_event_sync_stat(struct perf_event *event, |
2413 | struct perf_event *next_event) | |
bfbd3381 PZ |
2414 | { |
2415 | u64 value; | |
2416 | ||
cdd6c482 | 2417 | if (!event->attr.inherit_stat) |
bfbd3381 PZ |
2418 | return; |
2419 | ||
2420 | /* | |
cdd6c482 | 2421 | * Update the event value, we cannot use perf_event_read() |
bfbd3381 PZ |
2422 | * because we're in the middle of a context switch and have IRQs |
2423 | * disabled, which upsets smp_call_function_single(), however | |
cdd6c482 | 2424 | * we know the event must be on the current CPU, therefore we |
bfbd3381 PZ |
2425 | * don't need to use it. |
2426 | */ | |
cdd6c482 IM |
2427 | switch (event->state) { |
2428 | case PERF_EVENT_STATE_ACTIVE: | |
3dbebf15 PZ |
2429 | event->pmu->read(event); |
2430 | /* fall-through */ | |
bfbd3381 | 2431 | |
cdd6c482 IM |
2432 | case PERF_EVENT_STATE_INACTIVE: |
2433 | update_event_times(event); | |
bfbd3381 PZ |
2434 | break; |
2435 | ||
2436 | default: | |
2437 | break; | |
2438 | } | |
2439 | ||
2440 | /* | |
cdd6c482 | 2441 | * In order to keep per-task stats reliable we need to flip the event |
bfbd3381 PZ |
2442 | * values when we flip the contexts. |
2443 | */ | |
e7850595 PZ |
2444 | value = local64_read(&next_event->count); |
2445 | value = local64_xchg(&event->count, value); | |
2446 | local64_set(&next_event->count, value); | |
bfbd3381 | 2447 | |
cdd6c482 IM |
2448 | swap(event->total_time_enabled, next_event->total_time_enabled); |
2449 | swap(event->total_time_running, next_event->total_time_running); | |
19d2e755 | 2450 | |
bfbd3381 | 2451 | /* |
19d2e755 | 2452 | * Since we swizzled the values, update the user visible data too. |
bfbd3381 | 2453 | */ |
cdd6c482 IM |
2454 | perf_event_update_userpage(event); |
2455 | perf_event_update_userpage(next_event); | |
bfbd3381 PZ |
2456 | } |
2457 | ||
cdd6c482 IM |
2458 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
2459 | struct perf_event_context *next_ctx) | |
bfbd3381 | 2460 | { |
cdd6c482 | 2461 | struct perf_event *event, *next_event; |
bfbd3381 PZ |
2462 | |
2463 | if (!ctx->nr_stat) | |
2464 | return; | |
2465 | ||
02ffdbc8 PZ |
2466 | update_context_time(ctx); |
2467 | ||
cdd6c482 IM |
2468 | event = list_first_entry(&ctx->event_list, |
2469 | struct perf_event, event_entry); | |
bfbd3381 | 2470 | |
cdd6c482 IM |
2471 | next_event = list_first_entry(&next_ctx->event_list, |
2472 | struct perf_event, event_entry); | |
bfbd3381 | 2473 | |
cdd6c482 IM |
2474 | while (&event->event_entry != &ctx->event_list && |
2475 | &next_event->event_entry != &next_ctx->event_list) { | |
bfbd3381 | 2476 | |
cdd6c482 | 2477 | __perf_event_sync_stat(event, next_event); |
bfbd3381 | 2478 | |
cdd6c482 IM |
2479 | event = list_next_entry(event, event_entry); |
2480 | next_event = list_next_entry(next_event, event_entry); | |
bfbd3381 PZ |
2481 | } |
2482 | } | |
2483 | ||
fe4b04fa PZ |
2484 | static void perf_event_context_sched_out(struct task_struct *task, int ctxn, |
2485 | struct task_struct *next) | |
0793a61d | 2486 | { |
8dc85d54 | 2487 | struct perf_event_context *ctx = task->perf_event_ctxp[ctxn]; |
cdd6c482 | 2488 | struct perf_event_context *next_ctx; |
5a3126d4 | 2489 | struct perf_event_context *parent, *next_parent; |
108b02cf | 2490 | struct perf_cpu_context *cpuctx; |
c93f7669 | 2491 | int do_switch = 1; |
0793a61d | 2492 | |
108b02cf PZ |
2493 | if (likely(!ctx)) |
2494 | return; | |
10989fb2 | 2495 | |
108b02cf PZ |
2496 | cpuctx = __get_cpu_context(ctx); |
2497 | if (!cpuctx->task_ctx) | |
0793a61d TG |
2498 | return; |
2499 | ||
c93f7669 | 2500 | rcu_read_lock(); |
8dc85d54 | 2501 | next_ctx = next->perf_event_ctxp[ctxn]; |
5a3126d4 PZ |
2502 | if (!next_ctx) |
2503 | goto unlock; | |
2504 | ||
2505 | parent = rcu_dereference(ctx->parent_ctx); | |
2506 | next_parent = rcu_dereference(next_ctx->parent_ctx); | |
2507 | ||
2508 | /* If neither context have a parent context; they cannot be clones. */ | |
802c8a61 | 2509 | if (!parent && !next_parent) |
5a3126d4 PZ |
2510 | goto unlock; |
2511 | ||
2512 | if (next_parent == ctx || next_ctx == parent || next_parent == parent) { | |
c93f7669 PM |
2513 | /* |
2514 | * Looks like the two contexts are clones, so we might be | |
2515 | * able to optimize the context switch. We lock both | |
2516 | * contexts and check that they are clones under the | |
2517 | * lock (including re-checking that neither has been | |
2518 | * uncloned in the meantime). It doesn't matter which | |
2519 | * order we take the locks because no other cpu could | |
2520 | * be trying to lock both of these tasks. | |
2521 | */ | |
e625cce1 TG |
2522 | raw_spin_lock(&ctx->lock); |
2523 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); | |
c93f7669 | 2524 | if (context_equiv(ctx, next_ctx)) { |
665c2142 PZ |
2525 | /* |
2526 | * XXX do we need a memory barrier of sorts | |
cdd6c482 | 2527 | * wrt to rcu_dereference() of perf_event_ctxp |
665c2142 | 2528 | */ |
8dc85d54 PZ |
2529 | task->perf_event_ctxp[ctxn] = next_ctx; |
2530 | next->perf_event_ctxp[ctxn] = ctx; | |
c93f7669 PM |
2531 | ctx->task = next; |
2532 | next_ctx->task = task; | |
5a158c3c YZ |
2533 | |
2534 | swap(ctx->task_ctx_data, next_ctx->task_ctx_data); | |
2535 | ||
c93f7669 | 2536 | do_switch = 0; |
bfbd3381 | 2537 | |
cdd6c482 | 2538 | perf_event_sync_stat(ctx, next_ctx); |
c93f7669 | 2539 | } |
e625cce1 TG |
2540 | raw_spin_unlock(&next_ctx->lock); |
2541 | raw_spin_unlock(&ctx->lock); | |
564c2b21 | 2542 | } |
5a3126d4 | 2543 | unlock: |
c93f7669 | 2544 | rcu_read_unlock(); |
564c2b21 | 2545 | |
c93f7669 | 2546 | if (do_switch) { |
facc4307 | 2547 | raw_spin_lock(&ctx->lock); |
5b0311e1 | 2548 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
c93f7669 | 2549 | cpuctx->task_ctx = NULL; |
facc4307 | 2550 | raw_spin_unlock(&ctx->lock); |
c93f7669 | 2551 | } |
0793a61d TG |
2552 | } |
2553 | ||
ba532500 YZ |
2554 | void perf_sched_cb_dec(struct pmu *pmu) |
2555 | { | |
2556 | this_cpu_dec(perf_sched_cb_usages); | |
2557 | } | |
2558 | ||
2559 | void perf_sched_cb_inc(struct pmu *pmu) | |
2560 | { | |
2561 | this_cpu_inc(perf_sched_cb_usages); | |
2562 | } | |
2563 | ||
2564 | /* | |
2565 | * This function provides the context switch callback to the lower code | |
2566 | * layer. It is invoked ONLY when the context switch callback is enabled. | |
2567 | */ | |
2568 | static void perf_pmu_sched_task(struct task_struct *prev, | |
2569 | struct task_struct *next, | |
2570 | bool sched_in) | |
2571 | { | |
2572 | struct perf_cpu_context *cpuctx; | |
2573 | struct pmu *pmu; | |
2574 | unsigned long flags; | |
2575 | ||
2576 | if (prev == next) | |
2577 | return; | |
2578 | ||
2579 | local_irq_save(flags); | |
2580 | ||
2581 | rcu_read_lock(); | |
2582 | ||
2583 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
2584 | if (pmu->sched_task) { | |
2585 | cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); | |
2586 | ||
2587 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); | |
2588 | ||
2589 | perf_pmu_disable(pmu); | |
2590 | ||
2591 | pmu->sched_task(cpuctx->task_ctx, sched_in); | |
2592 | ||
2593 | perf_pmu_enable(pmu); | |
2594 | ||
2595 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
2596 | } | |
2597 | } | |
2598 | ||
2599 | rcu_read_unlock(); | |
2600 | ||
2601 | local_irq_restore(flags); | |
2602 | } | |
2603 | ||
45ac1403 AH |
2604 | static void perf_event_switch(struct task_struct *task, |
2605 | struct task_struct *next_prev, bool sched_in); | |
2606 | ||
8dc85d54 PZ |
2607 | #define for_each_task_context_nr(ctxn) \ |
2608 | for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++) | |
2609 | ||
2610 | /* | |
2611 | * Called from scheduler to remove the events of the current task, | |
2612 | * with interrupts disabled. | |
2613 | * | |
2614 | * We stop each event and update the event value in event->count. | |
2615 | * | |
2616 | * This does not protect us against NMI, but disable() | |
2617 | * sets the disabled bit in the control field of event _before_ | |
2618 | * accessing the event control register. If a NMI hits, then it will | |
2619 | * not restart the event. | |
2620 | */ | |
ab0cce56 JO |
2621 | void __perf_event_task_sched_out(struct task_struct *task, |
2622 | struct task_struct *next) | |
8dc85d54 PZ |
2623 | { |
2624 | int ctxn; | |
2625 | ||
ba532500 YZ |
2626 | if (__this_cpu_read(perf_sched_cb_usages)) |
2627 | perf_pmu_sched_task(task, next, false); | |
2628 | ||
45ac1403 AH |
2629 | if (atomic_read(&nr_switch_events)) |
2630 | perf_event_switch(task, next, false); | |
2631 | ||
8dc85d54 PZ |
2632 | for_each_task_context_nr(ctxn) |
2633 | perf_event_context_sched_out(task, ctxn, next); | |
e5d1367f SE |
2634 | |
2635 | /* | |
2636 | * if cgroup events exist on this CPU, then we need | |
2637 | * to check if we have to switch out PMU state. | |
2638 | * cgroup event are system-wide mode only | |
2639 | */ | |
4a32fea9 | 2640 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) |
a8d757ef | 2641 | perf_cgroup_sched_out(task, next); |
8dc85d54 PZ |
2642 | } |
2643 | ||
04dc2dbb | 2644 | static void task_ctx_sched_out(struct perf_event_context *ctx) |
a08b159f | 2645 | { |
108b02cf | 2646 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
a08b159f | 2647 | |
a63eaf34 PM |
2648 | if (!cpuctx->task_ctx) |
2649 | return; | |
012b84da IM |
2650 | |
2651 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) | |
2652 | return; | |
2653 | ||
04dc2dbb | 2654 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
a08b159f PM |
2655 | cpuctx->task_ctx = NULL; |
2656 | } | |
2657 | ||
5b0311e1 FW |
2658 | /* |
2659 | * Called with IRQs disabled | |
2660 | */ | |
2661 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, | |
2662 | enum event_type_t event_type) | |
2663 | { | |
2664 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); | |
04289bb9 IM |
2665 | } |
2666 | ||
235c7fc7 | 2667 | static void |
5b0311e1 | 2668 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
6e37738a | 2669 | struct perf_cpu_context *cpuctx) |
0793a61d | 2670 | { |
cdd6c482 | 2671 | struct perf_event *event; |
0793a61d | 2672 | |
889ff015 FW |
2673 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
2674 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2675 | continue; |
5632ab12 | 2676 | if (!event_filter_match(event)) |
3b6f9e5c PM |
2677 | continue; |
2678 | ||
e5d1367f SE |
2679 | /* may need to reset tstamp_enabled */ |
2680 | if (is_cgroup_event(event)) | |
2681 | perf_cgroup_mark_enabled(event, ctx); | |
2682 | ||
8c9ed8e1 | 2683 | if (group_can_go_on(event, cpuctx, 1)) |
6e37738a | 2684 | group_sched_in(event, cpuctx, ctx); |
3b6f9e5c PM |
2685 | |
2686 | /* | |
2687 | * If this pinned group hasn't been scheduled, | |
2688 | * put it in error state. | |
2689 | */ | |
cdd6c482 IM |
2690 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2691 | update_group_times(event); | |
2692 | event->state = PERF_EVENT_STATE_ERROR; | |
53cfbf59 | 2693 | } |
3b6f9e5c | 2694 | } |
5b0311e1 FW |
2695 | } |
2696 | ||
2697 | static void | |
2698 | ctx_flexible_sched_in(struct perf_event_context *ctx, | |
6e37738a | 2699 | struct perf_cpu_context *cpuctx) |
5b0311e1 FW |
2700 | { |
2701 | struct perf_event *event; | |
2702 | int can_add_hw = 1; | |
3b6f9e5c | 2703 | |
889ff015 FW |
2704 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
2705 | /* Ignore events in OFF or ERROR state */ | |
2706 | if (event->state <= PERF_EVENT_STATE_OFF) | |
3b6f9e5c | 2707 | continue; |
04289bb9 IM |
2708 | /* |
2709 | * Listen to the 'cpu' scheduling filter constraint | |
cdd6c482 | 2710 | * of events: |
04289bb9 | 2711 | */ |
5632ab12 | 2712 | if (!event_filter_match(event)) |
0793a61d TG |
2713 | continue; |
2714 | ||
e5d1367f SE |
2715 | /* may need to reset tstamp_enabled */ |
2716 | if (is_cgroup_event(event)) | |
2717 | perf_cgroup_mark_enabled(event, ctx); | |
2718 | ||
9ed6060d | 2719 | if (group_can_go_on(event, cpuctx, can_add_hw)) { |
6e37738a | 2720 | if (group_sched_in(event, cpuctx, ctx)) |
dd0e6ba2 | 2721 | can_add_hw = 0; |
9ed6060d | 2722 | } |
0793a61d | 2723 | } |
5b0311e1 FW |
2724 | } |
2725 | ||
2726 | static void | |
2727 | ctx_sched_in(struct perf_event_context *ctx, | |
2728 | struct perf_cpu_context *cpuctx, | |
e5d1367f SE |
2729 | enum event_type_t event_type, |
2730 | struct task_struct *task) | |
5b0311e1 | 2731 | { |
db24d33e | 2732 | int is_active = ctx->is_active; |
c994d613 PZ |
2733 | u64 now; |
2734 | ||
2735 | lockdep_assert_held(&ctx->lock); | |
e5d1367f | 2736 | |
db24d33e | 2737 | ctx->is_active |= event_type; |
5b0311e1 | 2738 | if (likely(!ctx->nr_events)) |
facc4307 | 2739 | return; |
5b0311e1 | 2740 | |
e5d1367f SE |
2741 | now = perf_clock(); |
2742 | ctx->timestamp = now; | |
3f7cce3c | 2743 | perf_cgroup_set_timestamp(task, ctx); |
5b0311e1 FW |
2744 | /* |
2745 | * First go through the list and put on any pinned groups | |
2746 | * in order to give them the best chance of going on. | |
2747 | */ | |
db24d33e | 2748 | if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) |
6e37738a | 2749 | ctx_pinned_sched_in(ctx, cpuctx); |
5b0311e1 FW |
2750 | |
2751 | /* Then walk through the lower prio flexible groups */ | |
db24d33e | 2752 | if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) |
6e37738a | 2753 | ctx_flexible_sched_in(ctx, cpuctx); |
235c7fc7 IM |
2754 | } |
2755 | ||
329c0e01 | 2756 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
e5d1367f SE |
2757 | enum event_type_t event_type, |
2758 | struct task_struct *task) | |
329c0e01 FW |
2759 | { |
2760 | struct perf_event_context *ctx = &cpuctx->ctx; | |
2761 | ||
e5d1367f | 2762 | ctx_sched_in(ctx, cpuctx, event_type, task); |
329c0e01 FW |
2763 | } |
2764 | ||
e5d1367f SE |
2765 | static void perf_event_context_sched_in(struct perf_event_context *ctx, |
2766 | struct task_struct *task) | |
235c7fc7 | 2767 | { |
108b02cf | 2768 | struct perf_cpu_context *cpuctx; |
235c7fc7 | 2769 | |
108b02cf | 2770 | cpuctx = __get_cpu_context(ctx); |
329c0e01 FW |
2771 | if (cpuctx->task_ctx == ctx) |
2772 | return; | |
2773 | ||
facc4307 | 2774 | perf_ctx_lock(cpuctx, ctx); |
1b9a644f | 2775 | perf_pmu_disable(ctx->pmu); |
329c0e01 FW |
2776 | /* |
2777 | * We want to keep the following priority order: | |
2778 | * cpu pinned (that don't need to move), task pinned, | |
2779 | * cpu flexible, task flexible. | |
2780 | */ | |
2781 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); | |
2782 | ||
1d5f003f GN |
2783 | if (ctx->nr_events) |
2784 | cpuctx->task_ctx = ctx; | |
9b33fa6b | 2785 | |
86b47c25 GN |
2786 | perf_event_sched_in(cpuctx, cpuctx->task_ctx, task); |
2787 | ||
facc4307 PZ |
2788 | perf_pmu_enable(ctx->pmu); |
2789 | perf_ctx_unlock(cpuctx, ctx); | |
235c7fc7 IM |
2790 | } |
2791 | ||
8dc85d54 PZ |
2792 | /* |
2793 | * Called from scheduler to add the events of the current task | |
2794 | * with interrupts disabled. | |
2795 | * | |
2796 | * We restore the event value and then enable it. | |
2797 | * | |
2798 | * This does not protect us against NMI, but enable() | |
2799 | * sets the enabled bit in the control field of event _before_ | |
2800 | * accessing the event control register. If a NMI hits, then it will | |
2801 | * keep the event running. | |
2802 | */ | |
ab0cce56 JO |
2803 | void __perf_event_task_sched_in(struct task_struct *prev, |
2804 | struct task_struct *task) | |
8dc85d54 PZ |
2805 | { |
2806 | struct perf_event_context *ctx; | |
2807 | int ctxn; | |
2808 | ||
7e41d177 PZ |
2809 | /* |
2810 | * If cgroup events exist on this CPU, then we need to check if we have | |
2811 | * to switch in PMU state; cgroup event are system-wide mode only. | |
2812 | * | |
2813 | * Since cgroup events are CPU events, we must schedule these in before | |
2814 | * we schedule in the task events. | |
2815 | */ | |
2816 | if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) | |
2817 | perf_cgroup_sched_in(prev, task); | |
2818 | ||
8dc85d54 PZ |
2819 | for_each_task_context_nr(ctxn) { |
2820 | ctx = task->perf_event_ctxp[ctxn]; | |
2821 | if (likely(!ctx)) | |
2822 | continue; | |
2823 | ||
e5d1367f | 2824 | perf_event_context_sched_in(ctx, task); |
8dc85d54 | 2825 | } |
d010b332 | 2826 | |
45ac1403 AH |
2827 | if (atomic_read(&nr_switch_events)) |
2828 | perf_event_switch(task, prev, true); | |
2829 | ||
ba532500 YZ |
2830 | if (__this_cpu_read(perf_sched_cb_usages)) |
2831 | perf_pmu_sched_task(prev, task, true); | |
235c7fc7 IM |
2832 | } |
2833 | ||
abd50713 PZ |
2834 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
2835 | { | |
2836 | u64 frequency = event->attr.sample_freq; | |
2837 | u64 sec = NSEC_PER_SEC; | |
2838 | u64 divisor, dividend; | |
2839 | ||
2840 | int count_fls, nsec_fls, frequency_fls, sec_fls; | |
2841 | ||
2842 | count_fls = fls64(count); | |
2843 | nsec_fls = fls64(nsec); | |
2844 | frequency_fls = fls64(frequency); | |
2845 | sec_fls = 30; | |
2846 | ||
2847 | /* | |
2848 | * We got @count in @nsec, with a target of sample_freq HZ | |
2849 | * the target period becomes: | |
2850 | * | |
2851 | * @count * 10^9 | |
2852 | * period = ------------------- | |
2853 | * @nsec * sample_freq | |
2854 | * | |
2855 | */ | |
2856 | ||
2857 | /* | |
2858 | * Reduce accuracy by one bit such that @a and @b converge | |
2859 | * to a similar magnitude. | |
2860 | */ | |
fe4b04fa | 2861 | #define REDUCE_FLS(a, b) \ |
abd50713 PZ |
2862 | do { \ |
2863 | if (a##_fls > b##_fls) { \ | |
2864 | a >>= 1; \ | |
2865 | a##_fls--; \ | |
2866 | } else { \ | |
2867 | b >>= 1; \ | |
2868 | b##_fls--; \ | |
2869 | } \ | |
2870 | } while (0) | |
2871 | ||
2872 | /* | |
2873 | * Reduce accuracy until either term fits in a u64, then proceed with | |
2874 | * the other, so that finally we can do a u64/u64 division. | |
2875 | */ | |
2876 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { | |
2877 | REDUCE_FLS(nsec, frequency); | |
2878 | REDUCE_FLS(sec, count); | |
2879 | } | |
2880 | ||
2881 | if (count_fls + sec_fls > 64) { | |
2882 | divisor = nsec * frequency; | |
2883 | ||
2884 | while (count_fls + sec_fls > 64) { | |
2885 | REDUCE_FLS(count, sec); | |
2886 | divisor >>= 1; | |
2887 | } | |
2888 | ||
2889 | dividend = count * sec; | |
2890 | } else { | |
2891 | dividend = count * sec; | |
2892 | ||
2893 | while (nsec_fls + frequency_fls > 64) { | |
2894 | REDUCE_FLS(nsec, frequency); | |
2895 | dividend >>= 1; | |
2896 | } | |
2897 | ||
2898 | divisor = nsec * frequency; | |
2899 | } | |
2900 | ||
f6ab91ad PZ |
2901 | if (!divisor) |
2902 | return dividend; | |
2903 | ||
abd50713 PZ |
2904 | return div64_u64(dividend, divisor); |
2905 | } | |
2906 | ||
e050e3f0 SE |
2907 | static DEFINE_PER_CPU(int, perf_throttled_count); |
2908 | static DEFINE_PER_CPU(u64, perf_throttled_seq); | |
2909 | ||
f39d47ff | 2910 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable) |
bd2b5b12 | 2911 | { |
cdd6c482 | 2912 | struct hw_perf_event *hwc = &event->hw; |
f6ab91ad | 2913 | s64 period, sample_period; |
bd2b5b12 PZ |
2914 | s64 delta; |
2915 | ||
abd50713 | 2916 | period = perf_calculate_period(event, nsec, count); |
bd2b5b12 PZ |
2917 | |
2918 | delta = (s64)(period - hwc->sample_period); | |
2919 | delta = (delta + 7) / 8; /* low pass filter */ | |
2920 | ||
2921 | sample_period = hwc->sample_period + delta; | |
2922 | ||
2923 | if (!sample_period) | |
2924 | sample_period = 1; | |
2925 | ||
bd2b5b12 | 2926 | hwc->sample_period = sample_period; |
abd50713 | 2927 | |
e7850595 | 2928 | if (local64_read(&hwc->period_left) > 8*sample_period) { |
f39d47ff SE |
2929 | if (disable) |
2930 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2931 | ||
e7850595 | 2932 | local64_set(&hwc->period_left, 0); |
f39d47ff SE |
2933 | |
2934 | if (disable) | |
2935 | event->pmu->start(event, PERF_EF_RELOAD); | |
abd50713 | 2936 | } |
bd2b5b12 PZ |
2937 | } |
2938 | ||
e050e3f0 SE |
2939 | /* |
2940 | * combine freq adjustment with unthrottling to avoid two passes over the | |
2941 | * events. At the same time, make sure, having freq events does not change | |
2942 | * the rate of unthrottling as that would introduce bias. | |
2943 | */ | |
2944 | static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, | |
2945 | int needs_unthr) | |
60db5e09 | 2946 | { |
cdd6c482 IM |
2947 | struct perf_event *event; |
2948 | struct hw_perf_event *hwc; | |
e050e3f0 | 2949 | u64 now, period = TICK_NSEC; |
abd50713 | 2950 | s64 delta; |
60db5e09 | 2951 | |
e050e3f0 SE |
2952 | /* |
2953 | * only need to iterate over all events iff: | |
2954 | * - context have events in frequency mode (needs freq adjust) | |
2955 | * - there are events to unthrottle on this cpu | |
2956 | */ | |
2957 | if (!(ctx->nr_freq || needs_unthr)) | |
0f5a2601 PZ |
2958 | return; |
2959 | ||
e050e3f0 | 2960 | raw_spin_lock(&ctx->lock); |
f39d47ff | 2961 | perf_pmu_disable(ctx->pmu); |
e050e3f0 | 2962 | |
03541f8b | 2963 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
cdd6c482 | 2964 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
60db5e09 PZ |
2965 | continue; |
2966 | ||
5632ab12 | 2967 | if (!event_filter_match(event)) |
5d27c23d PZ |
2968 | continue; |
2969 | ||
44377277 AS |
2970 | perf_pmu_disable(event->pmu); |
2971 | ||
cdd6c482 | 2972 | hwc = &event->hw; |
6a24ed6c | 2973 | |
ae23bff1 | 2974 | if (hwc->interrupts == MAX_INTERRUPTS) { |
e050e3f0 | 2975 | hwc->interrupts = 0; |
cdd6c482 | 2976 | perf_log_throttle(event, 1); |
a4eaf7f1 | 2977 | event->pmu->start(event, 0); |
a78ac325 PZ |
2978 | } |
2979 | ||
cdd6c482 | 2980 | if (!event->attr.freq || !event->attr.sample_freq) |
44377277 | 2981 | goto next; |
60db5e09 | 2982 | |
e050e3f0 SE |
2983 | /* |
2984 | * stop the event and update event->count | |
2985 | */ | |
2986 | event->pmu->stop(event, PERF_EF_UPDATE); | |
2987 | ||
e7850595 | 2988 | now = local64_read(&event->count); |
abd50713 PZ |
2989 | delta = now - hwc->freq_count_stamp; |
2990 | hwc->freq_count_stamp = now; | |
60db5e09 | 2991 | |
e050e3f0 SE |
2992 | /* |
2993 | * restart the event | |
2994 | * reload only if value has changed | |
f39d47ff SE |
2995 | * we have stopped the event so tell that |
2996 | * to perf_adjust_period() to avoid stopping it | |
2997 | * twice. | |
e050e3f0 | 2998 | */ |
abd50713 | 2999 | if (delta > 0) |
f39d47ff | 3000 | perf_adjust_period(event, period, delta, false); |
e050e3f0 SE |
3001 | |
3002 | event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); | |
44377277 AS |
3003 | next: |
3004 | perf_pmu_enable(event->pmu); | |
60db5e09 | 3005 | } |
e050e3f0 | 3006 | |
f39d47ff | 3007 | perf_pmu_enable(ctx->pmu); |
e050e3f0 | 3008 | raw_spin_unlock(&ctx->lock); |
60db5e09 PZ |
3009 | } |
3010 | ||
235c7fc7 | 3011 | /* |
cdd6c482 | 3012 | * Round-robin a context's events: |
235c7fc7 | 3013 | */ |
cdd6c482 | 3014 | static void rotate_ctx(struct perf_event_context *ctx) |
0793a61d | 3015 | { |
dddd3379 TG |
3016 | /* |
3017 | * Rotate the first entry last of non-pinned groups. Rotation might be | |
3018 | * disabled by the inheritance code. | |
3019 | */ | |
3020 | if (!ctx->rotate_disable) | |
3021 | list_rotate_left(&ctx->flexible_groups); | |
235c7fc7 IM |
3022 | } |
3023 | ||
9e630205 | 3024 | static int perf_rotate_context(struct perf_cpu_context *cpuctx) |
235c7fc7 | 3025 | { |
8dc85d54 | 3026 | struct perf_event_context *ctx = NULL; |
2fde4f94 | 3027 | int rotate = 0; |
7fc23a53 | 3028 | |
b5ab4cd5 | 3029 | if (cpuctx->ctx.nr_events) { |
b5ab4cd5 PZ |
3030 | if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
3031 | rotate = 1; | |
3032 | } | |
235c7fc7 | 3033 | |
8dc85d54 | 3034 | ctx = cpuctx->task_ctx; |
b5ab4cd5 | 3035 | if (ctx && ctx->nr_events) { |
b5ab4cd5 PZ |
3036 | if (ctx->nr_events != ctx->nr_active) |
3037 | rotate = 1; | |
3038 | } | |
9717e6cd | 3039 | |
e050e3f0 | 3040 | if (!rotate) |
0f5a2601 PZ |
3041 | goto done; |
3042 | ||
facc4307 | 3043 | perf_ctx_lock(cpuctx, cpuctx->task_ctx); |
1b9a644f | 3044 | perf_pmu_disable(cpuctx->ctx.pmu); |
60db5e09 | 3045 | |
e050e3f0 SE |
3046 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
3047 | if (ctx) | |
3048 | ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); | |
0793a61d | 3049 | |
e050e3f0 SE |
3050 | rotate_ctx(&cpuctx->ctx); |
3051 | if (ctx) | |
3052 | rotate_ctx(ctx); | |
235c7fc7 | 3053 | |
e050e3f0 | 3054 | perf_event_sched_in(cpuctx, ctx, current); |
235c7fc7 | 3055 | |
0f5a2601 PZ |
3056 | perf_pmu_enable(cpuctx->ctx.pmu); |
3057 | perf_ctx_unlock(cpuctx, cpuctx->task_ctx); | |
b5ab4cd5 | 3058 | done: |
9e630205 SE |
3059 | |
3060 | return rotate; | |
e9d2b064 PZ |
3061 | } |
3062 | ||
026249ef FW |
3063 | #ifdef CONFIG_NO_HZ_FULL |
3064 | bool perf_event_can_stop_tick(void) | |
3065 | { | |
948b26b6 | 3066 | if (atomic_read(&nr_freq_events) || |
d84153d6 | 3067 | __this_cpu_read(perf_throttled_count)) |
026249ef | 3068 | return false; |
d84153d6 FW |
3069 | else |
3070 | return true; | |
026249ef FW |
3071 | } |
3072 | #endif | |
3073 | ||
e9d2b064 PZ |
3074 | void perf_event_task_tick(void) |
3075 | { | |
2fde4f94 MR |
3076 | struct list_head *head = this_cpu_ptr(&active_ctx_list); |
3077 | struct perf_event_context *ctx, *tmp; | |
e050e3f0 | 3078 | int throttled; |
b5ab4cd5 | 3079 | |
e9d2b064 PZ |
3080 | WARN_ON(!irqs_disabled()); |
3081 | ||
e050e3f0 SE |
3082 | __this_cpu_inc(perf_throttled_seq); |
3083 | throttled = __this_cpu_xchg(perf_throttled_count, 0); | |
3084 | ||
2fde4f94 | 3085 | list_for_each_entry_safe(ctx, tmp, head, active_ctx_list) |
e050e3f0 | 3086 | perf_adjust_freq_unthr_context(ctx, throttled); |
0793a61d TG |
3087 | } |
3088 | ||
889ff015 FW |
3089 | static int event_enable_on_exec(struct perf_event *event, |
3090 | struct perf_event_context *ctx) | |
3091 | { | |
3092 | if (!event->attr.enable_on_exec) | |
3093 | return 0; | |
3094 | ||
3095 | event->attr.enable_on_exec = 0; | |
3096 | if (event->state >= PERF_EVENT_STATE_INACTIVE) | |
3097 | return 0; | |
3098 | ||
1d9b482e | 3099 | __perf_event_mark_enabled(event); |
889ff015 FW |
3100 | |
3101 | return 1; | |
3102 | } | |
3103 | ||
57e7986e | 3104 | /* |
cdd6c482 | 3105 | * Enable all of a task's events that have been marked enable-on-exec. |
57e7986e PM |
3106 | * This expects task == current. |
3107 | */ | |
c1274499 | 3108 | static void perf_event_enable_on_exec(int ctxn) |
57e7986e | 3109 | { |
c1274499 | 3110 | struct perf_event_context *ctx, *clone_ctx = NULL; |
cdd6c482 | 3111 | struct perf_event *event; |
57e7986e PM |
3112 | unsigned long flags; |
3113 | int enabled = 0; | |
889ff015 | 3114 | int ret; |
57e7986e PM |
3115 | |
3116 | local_irq_save(flags); | |
c1274499 | 3117 | ctx = current->perf_event_ctxp[ctxn]; |
cdd6c482 | 3118 | if (!ctx || !ctx->nr_events) |
57e7986e PM |
3119 | goto out; |
3120 | ||
e566b76e SE |
3121 | /* |
3122 | * We must ctxsw out cgroup events to avoid conflict | |
3123 | * when invoking perf_task_event_sched_in() later on | |
3124 | * in this function. Otherwise we end up trying to | |
3125 | * ctxswin cgroup events which are already scheduled | |
3126 | * in. | |
3127 | */ | |
a8d757ef | 3128 | perf_cgroup_sched_out(current, NULL); |
57e7986e | 3129 | |
e625cce1 | 3130 | raw_spin_lock(&ctx->lock); |
04dc2dbb | 3131 | task_ctx_sched_out(ctx); |
57e7986e | 3132 | |
b79387ef | 3133 | list_for_each_entry(event, &ctx->event_list, event_entry) { |
889ff015 FW |
3134 | ret = event_enable_on_exec(event, ctx); |
3135 | if (ret) | |
3136 | enabled = 1; | |
57e7986e PM |
3137 | } |
3138 | ||
3139 | /* | |
cdd6c482 | 3140 | * Unclone this context if we enabled any event. |
57e7986e | 3141 | */ |
71a851b4 | 3142 | if (enabled) |
211de6eb | 3143 | clone_ctx = unclone_ctx(ctx); |
57e7986e | 3144 | |
e625cce1 | 3145 | raw_spin_unlock(&ctx->lock); |
57e7986e | 3146 | |
e566b76e SE |
3147 | /* |
3148 | * Also calls ctxswin for cgroup events, if any: | |
3149 | */ | |
e5d1367f | 3150 | perf_event_context_sched_in(ctx, ctx->task); |
9ed6060d | 3151 | out: |
57e7986e | 3152 | local_irq_restore(flags); |
211de6eb PZ |
3153 | |
3154 | if (clone_ctx) | |
3155 | put_ctx(clone_ctx); | |
57e7986e PM |
3156 | } |
3157 | ||
e041e328 PZ |
3158 | void perf_event_exec(void) |
3159 | { | |
e041e328 PZ |
3160 | int ctxn; |
3161 | ||
3162 | rcu_read_lock(); | |
c1274499 PZ |
3163 | for_each_task_context_nr(ctxn) |
3164 | perf_event_enable_on_exec(ctxn); | |
e041e328 PZ |
3165 | rcu_read_unlock(); |
3166 | } | |
3167 | ||
0492d4c5 PZ |
3168 | struct perf_read_data { |
3169 | struct perf_event *event; | |
3170 | bool group; | |
7d88962e | 3171 | int ret; |
0492d4c5 PZ |
3172 | }; |
3173 | ||
0793a61d | 3174 | /* |
cdd6c482 | 3175 | * Cross CPU call to read the hardware event |
0793a61d | 3176 | */ |
cdd6c482 | 3177 | static void __perf_event_read(void *info) |
0793a61d | 3178 | { |
0492d4c5 PZ |
3179 | struct perf_read_data *data = info; |
3180 | struct perf_event *sub, *event = data->event; | |
cdd6c482 | 3181 | struct perf_event_context *ctx = event->ctx; |
108b02cf | 3182 | struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); |
4a00c16e | 3183 | struct pmu *pmu = event->pmu; |
621a01ea | 3184 | |
e1ac3614 PM |
3185 | /* |
3186 | * If this is a task context, we need to check whether it is | |
3187 | * the current task context of this cpu. If not it has been | |
3188 | * scheduled out before the smp call arrived. In that case | |
cdd6c482 IM |
3189 | * event->count would have been updated to a recent sample |
3190 | * when the event was scheduled out. | |
e1ac3614 PM |
3191 | */ |
3192 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3193 | return; | |
3194 | ||
e625cce1 | 3195 | raw_spin_lock(&ctx->lock); |
e5d1367f | 3196 | if (ctx->is_active) { |
542e72fc | 3197 | update_context_time(ctx); |
e5d1367f SE |
3198 | update_cgrp_time_from_event(event); |
3199 | } | |
0492d4c5 | 3200 | |
cdd6c482 | 3201 | update_event_times(event); |
4a00c16e SB |
3202 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
3203 | goto unlock; | |
0492d4c5 | 3204 | |
4a00c16e SB |
3205 | if (!data->group) { |
3206 | pmu->read(event); | |
3207 | data->ret = 0; | |
0492d4c5 | 3208 | goto unlock; |
4a00c16e SB |
3209 | } |
3210 | ||
3211 | pmu->start_txn(pmu, PERF_PMU_TXN_READ); | |
3212 | ||
3213 | pmu->read(event); | |
0492d4c5 PZ |
3214 | |
3215 | list_for_each_entry(sub, &event->sibling_list, group_entry) { | |
3216 | update_event_times(sub); | |
4a00c16e SB |
3217 | if (sub->state == PERF_EVENT_STATE_ACTIVE) { |
3218 | /* | |
3219 | * Use sibling's PMU rather than @event's since | |
3220 | * sibling could be on different (eg: software) PMU. | |
3221 | */ | |
0492d4c5 | 3222 | sub->pmu->read(sub); |
4a00c16e | 3223 | } |
0492d4c5 | 3224 | } |
4a00c16e SB |
3225 | |
3226 | data->ret = pmu->commit_txn(pmu); | |
0492d4c5 PZ |
3227 | |
3228 | unlock: | |
e625cce1 | 3229 | raw_spin_unlock(&ctx->lock); |
0793a61d TG |
3230 | } |
3231 | ||
b5e58793 PZ |
3232 | static inline u64 perf_event_count(struct perf_event *event) |
3233 | { | |
eacd3ecc MF |
3234 | if (event->pmu->count) |
3235 | return event->pmu->count(event); | |
3236 | ||
3237 | return __perf_event_count(event); | |
b5e58793 PZ |
3238 | } |
3239 | ||
ffe8690c KX |
3240 | /* |
3241 | * NMI-safe method to read a local event, that is an event that | |
3242 | * is: | |
3243 | * - either for the current task, or for this CPU | |
3244 | * - does not have inherit set, for inherited task events | |
3245 | * will not be local and we cannot read them atomically | |
3246 | * - must not have a pmu::count method | |
3247 | */ | |
3248 | u64 perf_event_read_local(struct perf_event *event) | |
3249 | { | |
3250 | unsigned long flags; | |
3251 | u64 val; | |
3252 | ||
3253 | /* | |
3254 | * Disabling interrupts avoids all counter scheduling (context | |
3255 | * switches, timer based rotation and IPIs). | |
3256 | */ | |
3257 | local_irq_save(flags); | |
3258 | ||
3259 | /* If this is a per-task event, it must be for current */ | |
3260 | WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && | |
3261 | event->hw.target != current); | |
3262 | ||
3263 | /* If this is a per-CPU event, it must be for this CPU */ | |
3264 | WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && | |
3265 | event->cpu != smp_processor_id()); | |
3266 | ||
3267 | /* | |
3268 | * It must not be an event with inherit set, we cannot read | |
3269 | * all child counters from atomic context. | |
3270 | */ | |
3271 | WARN_ON_ONCE(event->attr.inherit); | |
3272 | ||
3273 | /* | |
3274 | * It must not have a pmu::count method, those are not | |
3275 | * NMI safe. | |
3276 | */ | |
3277 | WARN_ON_ONCE(event->pmu->count); | |
3278 | ||
3279 | /* | |
3280 | * If the event is currently on this CPU, its either a per-task event, | |
3281 | * or local to this CPU. Furthermore it means its ACTIVE (otherwise | |
3282 | * oncpu == -1). | |
3283 | */ | |
3284 | if (event->oncpu == smp_processor_id()) | |
3285 | event->pmu->read(event); | |
3286 | ||
3287 | val = local64_read(&event->count); | |
3288 | local_irq_restore(flags); | |
3289 | ||
3290 | return val; | |
3291 | } | |
3292 | ||
7d88962e | 3293 | static int perf_event_read(struct perf_event *event, bool group) |
0793a61d | 3294 | { |
7d88962e SB |
3295 | int ret = 0; |
3296 | ||
0793a61d | 3297 | /* |
cdd6c482 IM |
3298 | * If event is enabled and currently active on a CPU, update the |
3299 | * value in the event structure: | |
0793a61d | 3300 | */ |
cdd6c482 | 3301 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
0492d4c5 PZ |
3302 | struct perf_read_data data = { |
3303 | .event = event, | |
3304 | .group = group, | |
7d88962e | 3305 | .ret = 0, |
0492d4c5 | 3306 | }; |
cdd6c482 | 3307 | smp_call_function_single(event->oncpu, |
0492d4c5 | 3308 | __perf_event_read, &data, 1); |
7d88962e | 3309 | ret = data.ret; |
cdd6c482 | 3310 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
2b8988c9 PZ |
3311 | struct perf_event_context *ctx = event->ctx; |
3312 | unsigned long flags; | |
3313 | ||
e625cce1 | 3314 | raw_spin_lock_irqsave(&ctx->lock, flags); |
c530ccd9 SE |
3315 | /* |
3316 | * may read while context is not active | |
3317 | * (e.g., thread is blocked), in that case | |
3318 | * we cannot update context time | |
3319 | */ | |
e5d1367f | 3320 | if (ctx->is_active) { |
c530ccd9 | 3321 | update_context_time(ctx); |
e5d1367f SE |
3322 | update_cgrp_time_from_event(event); |
3323 | } | |
0492d4c5 PZ |
3324 | if (group) |
3325 | update_group_times(event); | |
3326 | else | |
3327 | update_event_times(event); | |
e625cce1 | 3328 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
0793a61d | 3329 | } |
7d88962e SB |
3330 | |
3331 | return ret; | |
0793a61d TG |
3332 | } |
3333 | ||
a63eaf34 | 3334 | /* |
cdd6c482 | 3335 | * Initialize the perf_event context in a task_struct: |
a63eaf34 | 3336 | */ |
eb184479 | 3337 | static void __perf_event_init_context(struct perf_event_context *ctx) |
a63eaf34 | 3338 | { |
e625cce1 | 3339 | raw_spin_lock_init(&ctx->lock); |
a63eaf34 | 3340 | mutex_init(&ctx->mutex); |
2fde4f94 | 3341 | INIT_LIST_HEAD(&ctx->active_ctx_list); |
889ff015 FW |
3342 | INIT_LIST_HEAD(&ctx->pinned_groups); |
3343 | INIT_LIST_HEAD(&ctx->flexible_groups); | |
a63eaf34 PM |
3344 | INIT_LIST_HEAD(&ctx->event_list); |
3345 | atomic_set(&ctx->refcount, 1); | |
fadfe7be | 3346 | INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work); |
eb184479 PZ |
3347 | } |
3348 | ||
3349 | static struct perf_event_context * | |
3350 | alloc_perf_context(struct pmu *pmu, struct task_struct *task) | |
3351 | { | |
3352 | struct perf_event_context *ctx; | |
3353 | ||
3354 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); | |
3355 | if (!ctx) | |
3356 | return NULL; | |
3357 | ||
3358 | __perf_event_init_context(ctx); | |
3359 | if (task) { | |
3360 | ctx->task = task; | |
3361 | get_task_struct(task); | |
0793a61d | 3362 | } |
eb184479 PZ |
3363 | ctx->pmu = pmu; |
3364 | ||
3365 | return ctx; | |
a63eaf34 PM |
3366 | } |
3367 | ||
2ebd4ffb MH |
3368 | static struct task_struct * |
3369 | find_lively_task_by_vpid(pid_t vpid) | |
3370 | { | |
3371 | struct task_struct *task; | |
3372 | int err; | |
0793a61d TG |
3373 | |
3374 | rcu_read_lock(); | |
2ebd4ffb | 3375 | if (!vpid) |
0793a61d TG |
3376 | task = current; |
3377 | else | |
2ebd4ffb | 3378 | task = find_task_by_vpid(vpid); |
0793a61d TG |
3379 | if (task) |
3380 | get_task_struct(task); | |
3381 | rcu_read_unlock(); | |
3382 | ||
3383 | if (!task) | |
3384 | return ERR_PTR(-ESRCH); | |
3385 | ||
0793a61d | 3386 | /* Reuse ptrace permission checks for now. */ |
c93f7669 PM |
3387 | err = -EACCES; |
3388 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) | |
3389 | goto errout; | |
3390 | ||
2ebd4ffb MH |
3391 | return task; |
3392 | errout: | |
3393 | put_task_struct(task); | |
3394 | return ERR_PTR(err); | |
3395 | ||
3396 | } | |
3397 | ||
fe4b04fa PZ |
3398 | /* |
3399 | * Returns a matching context with refcount and pincount. | |
3400 | */ | |
108b02cf | 3401 | static struct perf_event_context * |
4af57ef2 YZ |
3402 | find_get_context(struct pmu *pmu, struct task_struct *task, |
3403 | struct perf_event *event) | |
0793a61d | 3404 | { |
211de6eb | 3405 | struct perf_event_context *ctx, *clone_ctx = NULL; |
22a4f650 | 3406 | struct perf_cpu_context *cpuctx; |
4af57ef2 | 3407 | void *task_ctx_data = NULL; |
25346b93 | 3408 | unsigned long flags; |
8dc85d54 | 3409 | int ctxn, err; |
4af57ef2 | 3410 | int cpu = event->cpu; |
0793a61d | 3411 | |
22a4ec72 | 3412 | if (!task) { |
cdd6c482 | 3413 | /* Must be root to operate on a CPU event: */ |
0764771d | 3414 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
0793a61d TG |
3415 | return ERR_PTR(-EACCES); |
3416 | ||
0793a61d | 3417 | /* |
cdd6c482 | 3418 | * We could be clever and allow to attach a event to an |
0793a61d TG |
3419 | * offline CPU and activate it when the CPU comes up, but |
3420 | * that's for later. | |
3421 | */ | |
f6325e30 | 3422 | if (!cpu_online(cpu)) |
0793a61d TG |
3423 | return ERR_PTR(-ENODEV); |
3424 | ||
108b02cf | 3425 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); |
0793a61d | 3426 | ctx = &cpuctx->ctx; |
c93f7669 | 3427 | get_ctx(ctx); |
fe4b04fa | 3428 | ++ctx->pin_count; |
0793a61d | 3429 | |
0793a61d TG |
3430 | return ctx; |
3431 | } | |
3432 | ||
8dc85d54 PZ |
3433 | err = -EINVAL; |
3434 | ctxn = pmu->task_ctx_nr; | |
3435 | if (ctxn < 0) | |
3436 | goto errout; | |
3437 | ||
4af57ef2 YZ |
3438 | if (event->attach_state & PERF_ATTACH_TASK_DATA) { |
3439 | task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); | |
3440 | if (!task_ctx_data) { | |
3441 | err = -ENOMEM; | |
3442 | goto errout; | |
3443 | } | |
3444 | } | |
3445 | ||
9ed6060d | 3446 | retry: |
8dc85d54 | 3447 | ctx = perf_lock_task_context(task, ctxn, &flags); |
c93f7669 | 3448 | if (ctx) { |
211de6eb | 3449 | clone_ctx = unclone_ctx(ctx); |
fe4b04fa | 3450 | ++ctx->pin_count; |
4af57ef2 YZ |
3451 | |
3452 | if (task_ctx_data && !ctx->task_ctx_data) { | |
3453 | ctx->task_ctx_data = task_ctx_data; | |
3454 | task_ctx_data = NULL; | |
3455 | } | |
e625cce1 | 3456 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
211de6eb PZ |
3457 | |
3458 | if (clone_ctx) | |
3459 | put_ctx(clone_ctx); | |
9137fb28 | 3460 | } else { |
eb184479 | 3461 | ctx = alloc_perf_context(pmu, task); |
c93f7669 PM |
3462 | err = -ENOMEM; |
3463 | if (!ctx) | |
3464 | goto errout; | |
eb184479 | 3465 | |
4af57ef2 YZ |
3466 | if (task_ctx_data) { |
3467 | ctx->task_ctx_data = task_ctx_data; | |
3468 | task_ctx_data = NULL; | |
3469 | } | |
3470 | ||
dbe08d82 ON |
3471 | err = 0; |
3472 | mutex_lock(&task->perf_event_mutex); | |
3473 | /* | |
3474 | * If it has already passed perf_event_exit_task(). | |
3475 | * we must see PF_EXITING, it takes this mutex too. | |
3476 | */ | |
3477 | if (task->flags & PF_EXITING) | |
3478 | err = -ESRCH; | |
3479 | else if (task->perf_event_ctxp[ctxn]) | |
3480 | err = -EAGAIN; | |
fe4b04fa | 3481 | else { |
9137fb28 | 3482 | get_ctx(ctx); |
fe4b04fa | 3483 | ++ctx->pin_count; |
dbe08d82 | 3484 | rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx); |
fe4b04fa | 3485 | } |
dbe08d82 ON |
3486 | mutex_unlock(&task->perf_event_mutex); |
3487 | ||
3488 | if (unlikely(err)) { | |
9137fb28 | 3489 | put_ctx(ctx); |
dbe08d82 ON |
3490 | |
3491 | if (err == -EAGAIN) | |
3492 | goto retry; | |
3493 | goto errout; | |
a63eaf34 PM |
3494 | } |
3495 | } | |
3496 | ||
4af57ef2 | 3497 | kfree(task_ctx_data); |
0793a61d | 3498 | return ctx; |
c93f7669 | 3499 | |
9ed6060d | 3500 | errout: |
4af57ef2 | 3501 | kfree(task_ctx_data); |
c93f7669 | 3502 | return ERR_PTR(err); |
0793a61d TG |
3503 | } |
3504 | ||
6fb2915d | 3505 | static void perf_event_free_filter(struct perf_event *event); |
2541517c | 3506 | static void perf_event_free_bpf_prog(struct perf_event *event); |
6fb2915d | 3507 | |
cdd6c482 | 3508 | static void free_event_rcu(struct rcu_head *head) |
592903cd | 3509 | { |
cdd6c482 | 3510 | struct perf_event *event; |
592903cd | 3511 | |
cdd6c482 IM |
3512 | event = container_of(head, struct perf_event, rcu_head); |
3513 | if (event->ns) | |
3514 | put_pid_ns(event->ns); | |
6fb2915d | 3515 | perf_event_free_filter(event); |
cdd6c482 | 3516 | kfree(event); |
592903cd PZ |
3517 | } |
3518 | ||
b69cf536 PZ |
3519 | static void ring_buffer_attach(struct perf_event *event, |
3520 | struct ring_buffer *rb); | |
925d519a | 3521 | |
4beb31f3 | 3522 | static void unaccount_event_cpu(struct perf_event *event, int cpu) |
f1600952 | 3523 | { |
4beb31f3 FW |
3524 | if (event->parent) |
3525 | return; | |
3526 | ||
4beb31f3 FW |
3527 | if (is_cgroup_event(event)) |
3528 | atomic_dec(&per_cpu(perf_cgroup_events, cpu)); | |
3529 | } | |
925d519a | 3530 | |
4beb31f3 FW |
3531 | static void unaccount_event(struct perf_event *event) |
3532 | { | |
3533 | if (event->parent) | |
3534 | return; | |
3535 | ||
3536 | if (event->attach_state & PERF_ATTACH_TASK) | |
3537 | static_key_slow_dec_deferred(&perf_sched_events); | |
3538 | if (event->attr.mmap || event->attr.mmap_data) | |
3539 | atomic_dec(&nr_mmap_events); | |
3540 | if (event->attr.comm) | |
3541 | atomic_dec(&nr_comm_events); | |
3542 | if (event->attr.task) | |
3543 | atomic_dec(&nr_task_events); | |
948b26b6 FW |
3544 | if (event->attr.freq) |
3545 | atomic_dec(&nr_freq_events); | |
45ac1403 AH |
3546 | if (event->attr.context_switch) { |
3547 | static_key_slow_dec_deferred(&perf_sched_events); | |
3548 | atomic_dec(&nr_switch_events); | |
3549 | } | |
4beb31f3 FW |
3550 | if (is_cgroup_event(event)) |
3551 | static_key_slow_dec_deferred(&perf_sched_events); | |
3552 | if (has_branch_stack(event)) | |
3553 | static_key_slow_dec_deferred(&perf_sched_events); | |
3554 | ||
3555 | unaccount_event_cpu(event, event->cpu); | |
3556 | } | |
925d519a | 3557 | |
bed5b25a AS |
3558 | /* |
3559 | * The following implement mutual exclusion of events on "exclusive" pmus | |
3560 | * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled | |
3561 | * at a time, so we disallow creating events that might conflict, namely: | |
3562 | * | |
3563 | * 1) cpu-wide events in the presence of per-task events, | |
3564 | * 2) per-task events in the presence of cpu-wide events, | |
3565 | * 3) two matching events on the same context. | |
3566 | * | |
3567 | * The former two cases are handled in the allocation path (perf_event_alloc(), | |
3568 | * __free_event()), the latter -- before the first perf_install_in_context(). | |
3569 | */ | |
3570 | static int exclusive_event_init(struct perf_event *event) | |
3571 | { | |
3572 | struct pmu *pmu = event->pmu; | |
3573 | ||
3574 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3575 | return 0; | |
3576 | ||
3577 | /* | |
3578 | * Prevent co-existence of per-task and cpu-wide events on the | |
3579 | * same exclusive pmu. | |
3580 | * | |
3581 | * Negative pmu::exclusive_cnt means there are cpu-wide | |
3582 | * events on this "exclusive" pmu, positive means there are | |
3583 | * per-task events. | |
3584 | * | |
3585 | * Since this is called in perf_event_alloc() path, event::ctx | |
3586 | * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK | |
3587 | * to mean "per-task event", because unlike other attach states it | |
3588 | * never gets cleared. | |
3589 | */ | |
3590 | if (event->attach_state & PERF_ATTACH_TASK) { | |
3591 | if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) | |
3592 | return -EBUSY; | |
3593 | } else { | |
3594 | if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) | |
3595 | return -EBUSY; | |
3596 | } | |
3597 | ||
3598 | return 0; | |
3599 | } | |
3600 | ||
3601 | static void exclusive_event_destroy(struct perf_event *event) | |
3602 | { | |
3603 | struct pmu *pmu = event->pmu; | |
3604 | ||
3605 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3606 | return; | |
3607 | ||
3608 | /* see comment in exclusive_event_init() */ | |
3609 | if (event->attach_state & PERF_ATTACH_TASK) | |
3610 | atomic_dec(&pmu->exclusive_cnt); | |
3611 | else | |
3612 | atomic_inc(&pmu->exclusive_cnt); | |
3613 | } | |
3614 | ||
3615 | static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2) | |
3616 | { | |
3617 | if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && | |
3618 | (e1->cpu == e2->cpu || | |
3619 | e1->cpu == -1 || | |
3620 | e2->cpu == -1)) | |
3621 | return true; | |
3622 | return false; | |
3623 | } | |
3624 | ||
3625 | /* Called under the same ctx::mutex as perf_install_in_context() */ | |
3626 | static bool exclusive_event_installable(struct perf_event *event, | |
3627 | struct perf_event_context *ctx) | |
3628 | { | |
3629 | struct perf_event *iter_event; | |
3630 | struct pmu *pmu = event->pmu; | |
3631 | ||
3632 | if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE)) | |
3633 | return true; | |
3634 | ||
3635 | list_for_each_entry(iter_event, &ctx->event_list, event_entry) { | |
3636 | if (exclusive_event_match(iter_event, event)) | |
3637 | return false; | |
3638 | } | |
3639 | ||
3640 | return true; | |
3641 | } | |
3642 | ||
766d6c07 FW |
3643 | static void __free_event(struct perf_event *event) |
3644 | { | |
cdd6c482 | 3645 | if (!event->parent) { |
927c7a9e FW |
3646 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) |
3647 | put_callchain_buffers(); | |
f344011c | 3648 | } |
9ee318a7 | 3649 | |
dead9f29 AS |
3650 | perf_event_free_bpf_prog(event); |
3651 | ||
766d6c07 FW |
3652 | if (event->destroy) |
3653 | event->destroy(event); | |
3654 | ||
3655 | if (event->ctx) | |
3656 | put_ctx(event->ctx); | |
3657 | ||
bed5b25a AS |
3658 | if (event->pmu) { |
3659 | exclusive_event_destroy(event); | |
c464c76e | 3660 | module_put(event->pmu->module); |
bed5b25a | 3661 | } |
c464c76e | 3662 | |
766d6c07 FW |
3663 | call_rcu(&event->rcu_head, free_event_rcu); |
3664 | } | |
683ede43 PZ |
3665 | |
3666 | static void _free_event(struct perf_event *event) | |
f1600952 | 3667 | { |
e360adbe | 3668 | irq_work_sync(&event->pending); |
925d519a | 3669 | |
4beb31f3 | 3670 | unaccount_event(event); |
9ee318a7 | 3671 | |
76369139 | 3672 | if (event->rb) { |
9bb5d40c PZ |
3673 | /* |
3674 | * Can happen when we close an event with re-directed output. | |
3675 | * | |
3676 | * Since we have a 0 refcount, perf_mmap_close() will skip | |
3677 | * over us; possibly making our ring_buffer_put() the last. | |
3678 | */ | |
3679 | mutex_lock(&event->mmap_mutex); | |
b69cf536 | 3680 | ring_buffer_attach(event, NULL); |
9bb5d40c | 3681 | mutex_unlock(&event->mmap_mutex); |
a4be7c27 PZ |
3682 | } |
3683 | ||
e5d1367f SE |
3684 | if (is_cgroup_event(event)) |
3685 | perf_detach_cgroup(event); | |
3686 | ||
766d6c07 | 3687 | __free_event(event); |
f1600952 PZ |
3688 | } |
3689 | ||
683ede43 PZ |
3690 | /* |
3691 | * Used to free events which have a known refcount of 1, such as in error paths | |
3692 | * where the event isn't exposed yet and inherited events. | |
3693 | */ | |
3694 | static void free_event(struct perf_event *event) | |
0793a61d | 3695 | { |
683ede43 PZ |
3696 | if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, |
3697 | "unexpected event refcount: %ld; ptr=%p\n", | |
3698 | atomic_long_read(&event->refcount), event)) { | |
3699 | /* leak to avoid use-after-free */ | |
3700 | return; | |
3701 | } | |
0793a61d | 3702 | |
683ede43 | 3703 | _free_event(event); |
0793a61d TG |
3704 | } |
3705 | ||
a66a3052 | 3706 | /* |
f8697762 | 3707 | * Remove user event from the owner task. |
a66a3052 | 3708 | */ |
f8697762 | 3709 | static void perf_remove_from_owner(struct perf_event *event) |
fb0459d7 | 3710 | { |
8882135b | 3711 | struct task_struct *owner; |
fb0459d7 | 3712 | |
8882135b PZ |
3713 | rcu_read_lock(); |
3714 | owner = ACCESS_ONCE(event->owner); | |
3715 | /* | |
3716 | * Matches the smp_wmb() in perf_event_exit_task(). If we observe | |
3717 | * !owner it means the list deletion is complete and we can indeed | |
3718 | * free this event, otherwise we need to serialize on | |
3719 | * owner->perf_event_mutex. | |
3720 | */ | |
3721 | smp_read_barrier_depends(); | |
3722 | if (owner) { | |
3723 | /* | |
3724 | * Since delayed_put_task_struct() also drops the last | |
3725 | * task reference we can safely take a new reference | |
3726 | * while holding the rcu_read_lock(). | |
3727 | */ | |
3728 | get_task_struct(owner); | |
3729 | } | |
3730 | rcu_read_unlock(); | |
3731 | ||
3732 | if (owner) { | |
f63a8daa PZ |
3733 | /* |
3734 | * If we're here through perf_event_exit_task() we're already | |
3735 | * holding ctx->mutex which would be an inversion wrt. the | |
3736 | * normal lock order. | |
3737 | * | |
3738 | * However we can safely take this lock because its the child | |
3739 | * ctx->mutex. | |
3740 | */ | |
3741 | mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING); | |
3742 | ||
8882135b PZ |
3743 | /* |
3744 | * We have to re-check the event->owner field, if it is cleared | |
3745 | * we raced with perf_event_exit_task(), acquiring the mutex | |
3746 | * ensured they're done, and we can proceed with freeing the | |
3747 | * event. | |
3748 | */ | |
3749 | if (event->owner) | |
3750 | list_del_init(&event->owner_entry); | |
3751 | mutex_unlock(&owner->perf_event_mutex); | |
3752 | put_task_struct(owner); | |
3753 | } | |
f8697762 JO |
3754 | } |
3755 | ||
f8697762 JO |
3756 | static void put_event(struct perf_event *event) |
3757 | { | |
a83fe28e | 3758 | struct perf_event_context *ctx; |
f8697762 JO |
3759 | |
3760 | if (!atomic_long_dec_and_test(&event->refcount)) | |
3761 | return; | |
3762 | ||
3763 | if (!is_kernel_event(event)) | |
3764 | perf_remove_from_owner(event); | |
8882135b | 3765 | |
683ede43 PZ |
3766 | /* |
3767 | * There are two ways this annotation is useful: | |
3768 | * | |
3769 | * 1) there is a lock recursion from perf_event_exit_task | |
3770 | * see the comment there. | |
3771 | * | |
3772 | * 2) there is a lock-inversion with mmap_sem through | |
b15f495b | 3773 | * perf_read_group(), which takes faults while |
683ede43 PZ |
3774 | * holding ctx->mutex, however this is called after |
3775 | * the last filedesc died, so there is no possibility | |
3776 | * to trigger the AB-BA case. | |
3777 | */ | |
a83fe28e PZ |
3778 | ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING); |
3779 | WARN_ON_ONCE(ctx->parent_ctx); | |
683ede43 | 3780 | perf_remove_from_context(event, true); |
d415a7f1 | 3781 | perf_event_ctx_unlock(event, ctx); |
683ede43 PZ |
3782 | |
3783 | _free_event(event); | |
a6fa941d AV |
3784 | } |
3785 | ||
683ede43 PZ |
3786 | int perf_event_release_kernel(struct perf_event *event) |
3787 | { | |
3788 | put_event(event); | |
3789 | return 0; | |
3790 | } | |
3791 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); | |
3792 | ||
8b10c5e2 PZ |
3793 | /* |
3794 | * Called when the last reference to the file is gone. | |
3795 | */ | |
a6fa941d AV |
3796 | static int perf_release(struct inode *inode, struct file *file) |
3797 | { | |
3798 | put_event(file->private_data); | |
3799 | return 0; | |
fb0459d7 | 3800 | } |
fb0459d7 | 3801 | |
fadfe7be JO |
3802 | /* |
3803 | * Remove all orphanes events from the context. | |
3804 | */ | |
3805 | static void orphans_remove_work(struct work_struct *work) | |
3806 | { | |
3807 | struct perf_event_context *ctx; | |
3808 | struct perf_event *event, *tmp; | |
3809 | ||
3810 | ctx = container_of(work, struct perf_event_context, | |
3811 | orphans_remove.work); | |
3812 | ||
3813 | mutex_lock(&ctx->mutex); | |
3814 | list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) { | |
3815 | struct perf_event *parent_event = event->parent; | |
3816 | ||
3817 | if (!is_orphaned_child(event)) | |
3818 | continue; | |
3819 | ||
3820 | perf_remove_from_context(event, true); | |
3821 | ||
3822 | mutex_lock(&parent_event->child_mutex); | |
3823 | list_del_init(&event->child_list); | |
3824 | mutex_unlock(&parent_event->child_mutex); | |
3825 | ||
3826 | free_event(event); | |
3827 | put_event(parent_event); | |
3828 | } | |
3829 | ||
3830 | raw_spin_lock_irq(&ctx->lock); | |
3831 | ctx->orphans_remove_sched = false; | |
3832 | raw_spin_unlock_irq(&ctx->lock); | |
3833 | mutex_unlock(&ctx->mutex); | |
3834 | ||
3835 | put_ctx(ctx); | |
3836 | } | |
3837 | ||
59ed446f | 3838 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
e53c0994 | 3839 | { |
cdd6c482 | 3840 | struct perf_event *child; |
e53c0994 PZ |
3841 | u64 total = 0; |
3842 | ||
59ed446f PZ |
3843 | *enabled = 0; |
3844 | *running = 0; | |
3845 | ||
6f10581a | 3846 | mutex_lock(&event->child_mutex); |
01add3ea | 3847 | |
7d88962e | 3848 | (void)perf_event_read(event, false); |
01add3ea SB |
3849 | total += perf_event_count(event); |
3850 | ||
59ed446f PZ |
3851 | *enabled += event->total_time_enabled + |
3852 | atomic64_read(&event->child_total_time_enabled); | |
3853 | *running += event->total_time_running + | |
3854 | atomic64_read(&event->child_total_time_running); | |
3855 | ||
3856 | list_for_each_entry(child, &event->child_list, child_list) { | |
7d88962e | 3857 | (void)perf_event_read(child, false); |
01add3ea | 3858 | total += perf_event_count(child); |
59ed446f PZ |
3859 | *enabled += child->total_time_enabled; |
3860 | *running += child->total_time_running; | |
3861 | } | |
6f10581a | 3862 | mutex_unlock(&event->child_mutex); |
e53c0994 PZ |
3863 | |
3864 | return total; | |
3865 | } | |
fb0459d7 | 3866 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
e53c0994 | 3867 | |
7d88962e | 3868 | static int __perf_read_group_add(struct perf_event *leader, |
fa8c2693 | 3869 | u64 read_format, u64 *values) |
3dab77fb | 3870 | { |
fa8c2693 PZ |
3871 | struct perf_event *sub; |
3872 | int n = 1; /* skip @nr */ | |
7d88962e | 3873 | int ret; |
f63a8daa | 3874 | |
7d88962e SB |
3875 | ret = perf_event_read(leader, true); |
3876 | if (ret) | |
3877 | return ret; | |
abf4868b | 3878 | |
fa8c2693 PZ |
3879 | /* |
3880 | * Since we co-schedule groups, {enabled,running} times of siblings | |
3881 | * will be identical to those of the leader, so we only publish one | |
3882 | * set. | |
3883 | */ | |
3884 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { | |
3885 | values[n++] += leader->total_time_enabled + | |
3886 | atomic64_read(&leader->child_total_time_enabled); | |
3887 | } | |
3dab77fb | 3888 | |
fa8c2693 PZ |
3889 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
3890 | values[n++] += leader->total_time_running + | |
3891 | atomic64_read(&leader->child_total_time_running); | |
3892 | } | |
3893 | ||
3894 | /* | |
3895 | * Write {count,id} tuples for every sibling. | |
3896 | */ | |
3897 | values[n++] += perf_event_count(leader); | |
abf4868b PZ |
3898 | if (read_format & PERF_FORMAT_ID) |
3899 | values[n++] = primary_event_id(leader); | |
3dab77fb | 3900 | |
fa8c2693 PZ |
3901 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3902 | values[n++] += perf_event_count(sub); | |
3903 | if (read_format & PERF_FORMAT_ID) | |
3904 | values[n++] = primary_event_id(sub); | |
3905 | } | |
7d88962e SB |
3906 | |
3907 | return 0; | |
fa8c2693 | 3908 | } |
3dab77fb | 3909 | |
fa8c2693 PZ |
3910 | static int perf_read_group(struct perf_event *event, |
3911 | u64 read_format, char __user *buf) | |
3912 | { | |
3913 | struct perf_event *leader = event->group_leader, *child; | |
3914 | struct perf_event_context *ctx = leader->ctx; | |
7d88962e | 3915 | int ret; |
fa8c2693 | 3916 | u64 *values; |
3dab77fb | 3917 | |
fa8c2693 | 3918 | lockdep_assert_held(&ctx->mutex); |
3dab77fb | 3919 | |
fa8c2693 PZ |
3920 | values = kzalloc(event->read_size, GFP_KERNEL); |
3921 | if (!values) | |
3922 | return -ENOMEM; | |
3dab77fb | 3923 | |
fa8c2693 PZ |
3924 | values[0] = 1 + leader->nr_siblings; |
3925 | ||
3926 | /* | |
3927 | * By locking the child_mutex of the leader we effectively | |
3928 | * lock the child list of all siblings.. XXX explain how. | |
3929 | */ | |
3930 | mutex_lock(&leader->child_mutex); | |
abf4868b | 3931 | |
7d88962e SB |
3932 | ret = __perf_read_group_add(leader, read_format, values); |
3933 | if (ret) | |
3934 | goto unlock; | |
3935 | ||
3936 | list_for_each_entry(child, &leader->child_list, child_list) { | |
3937 | ret = __perf_read_group_add(child, read_format, values); | |
3938 | if (ret) | |
3939 | goto unlock; | |
3940 | } | |
abf4868b | 3941 | |
fa8c2693 | 3942 | mutex_unlock(&leader->child_mutex); |
abf4868b | 3943 | |
7d88962e | 3944 | ret = event->read_size; |
fa8c2693 PZ |
3945 | if (copy_to_user(buf, values, event->read_size)) |
3946 | ret = -EFAULT; | |
7d88962e | 3947 | goto out; |
fa8c2693 | 3948 | |
7d88962e SB |
3949 | unlock: |
3950 | mutex_unlock(&leader->child_mutex); | |
3951 | out: | |
fa8c2693 | 3952 | kfree(values); |
abf4868b | 3953 | return ret; |
3dab77fb PZ |
3954 | } |
3955 | ||
b15f495b | 3956 | static int perf_read_one(struct perf_event *event, |
3dab77fb PZ |
3957 | u64 read_format, char __user *buf) |
3958 | { | |
59ed446f | 3959 | u64 enabled, running; |
3dab77fb PZ |
3960 | u64 values[4]; |
3961 | int n = 0; | |
3962 | ||
59ed446f PZ |
3963 | values[n++] = perf_event_read_value(event, &enabled, &running); |
3964 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
3965 | values[n++] = enabled; | |
3966 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
3967 | values[n++] = running; | |
3dab77fb | 3968 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 3969 | values[n++] = primary_event_id(event); |
3dab77fb PZ |
3970 | |
3971 | if (copy_to_user(buf, values, n * sizeof(u64))) | |
3972 | return -EFAULT; | |
3973 | ||
3974 | return n * sizeof(u64); | |
3975 | } | |
3976 | ||
dc633982 JO |
3977 | static bool is_event_hup(struct perf_event *event) |
3978 | { | |
3979 | bool no_children; | |
3980 | ||
3981 | if (event->state != PERF_EVENT_STATE_EXIT) | |
3982 | return false; | |
3983 | ||
3984 | mutex_lock(&event->child_mutex); | |
3985 | no_children = list_empty(&event->child_list); | |
3986 | mutex_unlock(&event->child_mutex); | |
3987 | return no_children; | |
3988 | } | |
3989 | ||
0793a61d | 3990 | /* |
cdd6c482 | 3991 | * Read the performance event - simple non blocking version for now |
0793a61d TG |
3992 | */ |
3993 | static ssize_t | |
b15f495b | 3994 | __perf_read(struct perf_event *event, char __user *buf, size_t count) |
0793a61d | 3995 | { |
cdd6c482 | 3996 | u64 read_format = event->attr.read_format; |
3dab77fb | 3997 | int ret; |
0793a61d | 3998 | |
3b6f9e5c | 3999 | /* |
cdd6c482 | 4000 | * Return end-of-file for a read on a event that is in |
3b6f9e5c PM |
4001 | * error state (i.e. because it was pinned but it couldn't be |
4002 | * scheduled on to the CPU at some point). | |
4003 | */ | |
cdd6c482 | 4004 | if (event->state == PERF_EVENT_STATE_ERROR) |
3b6f9e5c PM |
4005 | return 0; |
4006 | ||
c320c7b7 | 4007 | if (count < event->read_size) |
3dab77fb PZ |
4008 | return -ENOSPC; |
4009 | ||
cdd6c482 | 4010 | WARN_ON_ONCE(event->ctx->parent_ctx); |
3dab77fb | 4011 | if (read_format & PERF_FORMAT_GROUP) |
b15f495b | 4012 | ret = perf_read_group(event, read_format, buf); |
3dab77fb | 4013 | else |
b15f495b | 4014 | ret = perf_read_one(event, read_format, buf); |
0793a61d | 4015 | |
3dab77fb | 4016 | return ret; |
0793a61d TG |
4017 | } |
4018 | ||
0793a61d TG |
4019 | static ssize_t |
4020 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
4021 | { | |
cdd6c482 | 4022 | struct perf_event *event = file->private_data; |
f63a8daa PZ |
4023 | struct perf_event_context *ctx; |
4024 | int ret; | |
0793a61d | 4025 | |
f63a8daa | 4026 | ctx = perf_event_ctx_lock(event); |
b15f495b | 4027 | ret = __perf_read(event, buf, count); |
f63a8daa PZ |
4028 | perf_event_ctx_unlock(event, ctx); |
4029 | ||
4030 | return ret; | |
0793a61d TG |
4031 | } |
4032 | ||
4033 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
4034 | { | |
cdd6c482 | 4035 | struct perf_event *event = file->private_data; |
76369139 | 4036 | struct ring_buffer *rb; |
61b67684 | 4037 | unsigned int events = POLLHUP; |
c7138f37 | 4038 | |
e708d7ad | 4039 | poll_wait(file, &event->waitq, wait); |
179033b3 | 4040 | |
dc633982 | 4041 | if (is_event_hup(event)) |
179033b3 | 4042 | return events; |
c7138f37 | 4043 | |
10c6db11 | 4044 | /* |
9bb5d40c PZ |
4045 | * Pin the event->rb by taking event->mmap_mutex; otherwise |
4046 | * perf_event_set_output() can swizzle our rb and make us miss wakeups. | |
10c6db11 PZ |
4047 | */ |
4048 | mutex_lock(&event->mmap_mutex); | |
9bb5d40c PZ |
4049 | rb = event->rb; |
4050 | if (rb) | |
76369139 | 4051 | events = atomic_xchg(&rb->poll, 0); |
10c6db11 | 4052 | mutex_unlock(&event->mmap_mutex); |
0793a61d TG |
4053 | return events; |
4054 | } | |
4055 | ||
f63a8daa | 4056 | static void _perf_event_reset(struct perf_event *event) |
6de6a7b9 | 4057 | { |
7d88962e | 4058 | (void)perf_event_read(event, false); |
e7850595 | 4059 | local64_set(&event->count, 0); |
cdd6c482 | 4060 | perf_event_update_userpage(event); |
3df5edad PZ |
4061 | } |
4062 | ||
c93f7669 | 4063 | /* |
cdd6c482 IM |
4064 | * Holding the top-level event's child_mutex means that any |
4065 | * descendant process that has inherited this event will block | |
4066 | * in sync_child_event if it goes to exit, thus satisfying the | |
4067 | * task existence requirements of perf_event_enable/disable. | |
c93f7669 | 4068 | */ |
cdd6c482 IM |
4069 | static void perf_event_for_each_child(struct perf_event *event, |
4070 | void (*func)(struct perf_event *)) | |
3df5edad | 4071 | { |
cdd6c482 | 4072 | struct perf_event *child; |
3df5edad | 4073 | |
cdd6c482 | 4074 | WARN_ON_ONCE(event->ctx->parent_ctx); |
f63a8daa | 4075 | |
cdd6c482 IM |
4076 | mutex_lock(&event->child_mutex); |
4077 | func(event); | |
4078 | list_for_each_entry(child, &event->child_list, child_list) | |
3df5edad | 4079 | func(child); |
cdd6c482 | 4080 | mutex_unlock(&event->child_mutex); |
3df5edad PZ |
4081 | } |
4082 | ||
cdd6c482 IM |
4083 | static void perf_event_for_each(struct perf_event *event, |
4084 | void (*func)(struct perf_event *)) | |
3df5edad | 4085 | { |
cdd6c482 IM |
4086 | struct perf_event_context *ctx = event->ctx; |
4087 | struct perf_event *sibling; | |
3df5edad | 4088 | |
f63a8daa PZ |
4089 | lockdep_assert_held(&ctx->mutex); |
4090 | ||
cdd6c482 | 4091 | event = event->group_leader; |
75f937f2 | 4092 | |
cdd6c482 | 4093 | perf_event_for_each_child(event, func); |
cdd6c482 | 4094 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
724b6daa | 4095 | perf_event_for_each_child(sibling, func); |
6de6a7b9 PZ |
4096 | } |
4097 | ||
c7999c6f PZ |
4098 | struct period_event { |
4099 | struct perf_event *event; | |
08247e31 | 4100 | u64 value; |
c7999c6f | 4101 | }; |
08247e31 | 4102 | |
0017960f PZ |
4103 | static void ___perf_event_period(void *info) |
4104 | { | |
4105 | struct period_event *pe = info; | |
4106 | struct perf_event *event = pe->event; | |
4107 | u64 value = pe->value; | |
4108 | ||
4109 | if (event->attr.freq) { | |
4110 | event->attr.sample_freq = value; | |
4111 | } else { | |
4112 | event->attr.sample_period = value; | |
4113 | event->hw.sample_period = value; | |
4114 | } | |
4115 | ||
4116 | local64_set(&event->hw.period_left, 0); | |
4117 | } | |
4118 | ||
c7999c6f PZ |
4119 | static int __perf_event_period(void *info) |
4120 | { | |
4121 | struct period_event *pe = info; | |
4122 | struct perf_event *event = pe->event; | |
4123 | struct perf_event_context *ctx = event->ctx; | |
4124 | u64 value = pe->value; | |
4125 | bool active; | |
08247e31 | 4126 | |
c7999c6f | 4127 | raw_spin_lock(&ctx->lock); |
cdd6c482 | 4128 | if (event->attr.freq) { |
cdd6c482 | 4129 | event->attr.sample_freq = value; |
08247e31 | 4130 | } else { |
cdd6c482 IM |
4131 | event->attr.sample_period = value; |
4132 | event->hw.sample_period = value; | |
08247e31 | 4133 | } |
bad7192b PZ |
4134 | |
4135 | active = (event->state == PERF_EVENT_STATE_ACTIVE); | |
4136 | if (active) { | |
4137 | perf_pmu_disable(ctx->pmu); | |
4138 | event->pmu->stop(event, PERF_EF_UPDATE); | |
4139 | } | |
4140 | ||
4141 | local64_set(&event->hw.period_left, 0); | |
4142 | ||
4143 | if (active) { | |
4144 | event->pmu->start(event, PERF_EF_RELOAD); | |
4145 | perf_pmu_enable(ctx->pmu); | |
4146 | } | |
c7999c6f | 4147 | raw_spin_unlock(&ctx->lock); |
bad7192b | 4148 | |
c7999c6f PZ |
4149 | return 0; |
4150 | } | |
4151 | ||
4152 | static int perf_event_period(struct perf_event *event, u64 __user *arg) | |
4153 | { | |
4154 | struct period_event pe = { .event = event, }; | |
c7999c6f PZ |
4155 | u64 value; |
4156 | ||
4157 | if (!is_sampling_event(event)) | |
4158 | return -EINVAL; | |
4159 | ||
4160 | if (copy_from_user(&value, arg, sizeof(value))) | |
4161 | return -EFAULT; | |
4162 | ||
4163 | if (!value) | |
4164 | return -EINVAL; | |
4165 | ||
4166 | if (event->attr.freq && value > sysctl_perf_event_sample_rate) | |
4167 | return -EINVAL; | |
4168 | ||
c7999c6f PZ |
4169 | pe.value = value; |
4170 | ||
0017960f PZ |
4171 | event_function_call(event, __perf_event_period, |
4172 | ___perf_event_period, &pe); | |
08247e31 | 4173 | |
c7999c6f | 4174 | return 0; |
08247e31 PZ |
4175 | } |
4176 | ||
ac9721f3 PZ |
4177 | static const struct file_operations perf_fops; |
4178 | ||
2903ff01 | 4179 | static inline int perf_fget_light(int fd, struct fd *p) |
ac9721f3 | 4180 | { |
2903ff01 AV |
4181 | struct fd f = fdget(fd); |
4182 | if (!f.file) | |
4183 | return -EBADF; | |
ac9721f3 | 4184 | |
2903ff01 AV |
4185 | if (f.file->f_op != &perf_fops) { |
4186 | fdput(f); | |
4187 | return -EBADF; | |
ac9721f3 | 4188 | } |
2903ff01 AV |
4189 | *p = f; |
4190 | return 0; | |
ac9721f3 PZ |
4191 | } |
4192 | ||
4193 | static int perf_event_set_output(struct perf_event *event, | |
4194 | struct perf_event *output_event); | |
6fb2915d | 4195 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
2541517c | 4196 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); |
a4be7c27 | 4197 | |
f63a8daa | 4198 | static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) |
d859e29f | 4199 | { |
cdd6c482 | 4200 | void (*func)(struct perf_event *); |
3df5edad | 4201 | u32 flags = arg; |
d859e29f PM |
4202 | |
4203 | switch (cmd) { | |
cdd6c482 | 4204 | case PERF_EVENT_IOC_ENABLE: |
f63a8daa | 4205 | func = _perf_event_enable; |
d859e29f | 4206 | break; |
cdd6c482 | 4207 | case PERF_EVENT_IOC_DISABLE: |
f63a8daa | 4208 | func = _perf_event_disable; |
79f14641 | 4209 | break; |
cdd6c482 | 4210 | case PERF_EVENT_IOC_RESET: |
f63a8daa | 4211 | func = _perf_event_reset; |
6de6a7b9 | 4212 | break; |
3df5edad | 4213 | |
cdd6c482 | 4214 | case PERF_EVENT_IOC_REFRESH: |
f63a8daa | 4215 | return _perf_event_refresh(event, arg); |
08247e31 | 4216 | |
cdd6c482 IM |
4217 | case PERF_EVENT_IOC_PERIOD: |
4218 | return perf_event_period(event, (u64 __user *)arg); | |
08247e31 | 4219 | |
cf4957f1 JO |
4220 | case PERF_EVENT_IOC_ID: |
4221 | { | |
4222 | u64 id = primary_event_id(event); | |
4223 | ||
4224 | if (copy_to_user((void __user *)arg, &id, sizeof(id))) | |
4225 | return -EFAULT; | |
4226 | return 0; | |
4227 | } | |
4228 | ||
cdd6c482 | 4229 | case PERF_EVENT_IOC_SET_OUTPUT: |
ac9721f3 | 4230 | { |
ac9721f3 | 4231 | int ret; |
ac9721f3 | 4232 | if (arg != -1) { |
2903ff01 AV |
4233 | struct perf_event *output_event; |
4234 | struct fd output; | |
4235 | ret = perf_fget_light(arg, &output); | |
4236 | if (ret) | |
4237 | return ret; | |
4238 | output_event = output.file->private_data; | |
4239 | ret = perf_event_set_output(event, output_event); | |
4240 | fdput(output); | |
4241 | } else { | |
4242 | ret = perf_event_set_output(event, NULL); | |
ac9721f3 | 4243 | } |
ac9721f3 PZ |
4244 | return ret; |
4245 | } | |
a4be7c27 | 4246 | |
6fb2915d LZ |
4247 | case PERF_EVENT_IOC_SET_FILTER: |
4248 | return perf_event_set_filter(event, (void __user *)arg); | |
4249 | ||
2541517c AS |
4250 | case PERF_EVENT_IOC_SET_BPF: |
4251 | return perf_event_set_bpf_prog(event, arg); | |
4252 | ||
d859e29f | 4253 | default: |
3df5edad | 4254 | return -ENOTTY; |
d859e29f | 4255 | } |
3df5edad PZ |
4256 | |
4257 | if (flags & PERF_IOC_FLAG_GROUP) | |
cdd6c482 | 4258 | perf_event_for_each(event, func); |
3df5edad | 4259 | else |
cdd6c482 | 4260 | perf_event_for_each_child(event, func); |
3df5edad PZ |
4261 | |
4262 | return 0; | |
d859e29f PM |
4263 | } |
4264 | ||
f63a8daa PZ |
4265 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
4266 | { | |
4267 | struct perf_event *event = file->private_data; | |
4268 | struct perf_event_context *ctx; | |
4269 | long ret; | |
4270 | ||
4271 | ctx = perf_event_ctx_lock(event); | |
4272 | ret = _perf_ioctl(event, cmd, arg); | |
4273 | perf_event_ctx_unlock(event, ctx); | |
4274 | ||
4275 | return ret; | |
4276 | } | |
4277 | ||
b3f20785 PM |
4278 | #ifdef CONFIG_COMPAT |
4279 | static long perf_compat_ioctl(struct file *file, unsigned int cmd, | |
4280 | unsigned long arg) | |
4281 | { | |
4282 | switch (_IOC_NR(cmd)) { | |
4283 | case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): | |
4284 | case _IOC_NR(PERF_EVENT_IOC_ID): | |
4285 | /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ | |
4286 | if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { | |
4287 | cmd &= ~IOCSIZE_MASK; | |
4288 | cmd |= sizeof(void *) << IOCSIZE_SHIFT; | |
4289 | } | |
4290 | break; | |
4291 | } | |
4292 | return perf_ioctl(file, cmd, arg); | |
4293 | } | |
4294 | #else | |
4295 | # define perf_compat_ioctl NULL | |
4296 | #endif | |
4297 | ||
cdd6c482 | 4298 | int perf_event_task_enable(void) |
771d7cde | 4299 | { |
f63a8daa | 4300 | struct perf_event_context *ctx; |
cdd6c482 | 4301 | struct perf_event *event; |
771d7cde | 4302 | |
cdd6c482 | 4303 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4304 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4305 | ctx = perf_event_ctx_lock(event); | |
4306 | perf_event_for_each_child(event, _perf_event_enable); | |
4307 | perf_event_ctx_unlock(event, ctx); | |
4308 | } | |
cdd6c482 | 4309 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4310 | |
4311 | return 0; | |
4312 | } | |
4313 | ||
cdd6c482 | 4314 | int perf_event_task_disable(void) |
771d7cde | 4315 | { |
f63a8daa | 4316 | struct perf_event_context *ctx; |
cdd6c482 | 4317 | struct perf_event *event; |
771d7cde | 4318 | |
cdd6c482 | 4319 | mutex_lock(¤t->perf_event_mutex); |
f63a8daa PZ |
4320 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { |
4321 | ctx = perf_event_ctx_lock(event); | |
4322 | perf_event_for_each_child(event, _perf_event_disable); | |
4323 | perf_event_ctx_unlock(event, ctx); | |
4324 | } | |
cdd6c482 | 4325 | mutex_unlock(¤t->perf_event_mutex); |
771d7cde PZ |
4326 | |
4327 | return 0; | |
4328 | } | |
4329 | ||
cdd6c482 | 4330 | static int perf_event_index(struct perf_event *event) |
194002b2 | 4331 | { |
a4eaf7f1 PZ |
4332 | if (event->hw.state & PERF_HES_STOPPED) |
4333 | return 0; | |
4334 | ||
cdd6c482 | 4335 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
194002b2 PZ |
4336 | return 0; |
4337 | ||
35edc2a5 | 4338 | return event->pmu->event_idx(event); |
194002b2 PZ |
4339 | } |
4340 | ||
c4794295 | 4341 | static void calc_timer_values(struct perf_event *event, |
e3f3541c | 4342 | u64 *now, |
7f310a5d EM |
4343 | u64 *enabled, |
4344 | u64 *running) | |
c4794295 | 4345 | { |
e3f3541c | 4346 | u64 ctx_time; |
c4794295 | 4347 | |
e3f3541c PZ |
4348 | *now = perf_clock(); |
4349 | ctx_time = event->shadow_ctx_time + *now; | |
c4794295 EM |
4350 | *enabled = ctx_time - event->tstamp_enabled; |
4351 | *running = ctx_time - event->tstamp_running; | |
4352 | } | |
4353 | ||
fa731587 PZ |
4354 | static void perf_event_init_userpage(struct perf_event *event) |
4355 | { | |
4356 | struct perf_event_mmap_page *userpg; | |
4357 | struct ring_buffer *rb; | |
4358 | ||
4359 | rcu_read_lock(); | |
4360 | rb = rcu_dereference(event->rb); | |
4361 | if (!rb) | |
4362 | goto unlock; | |
4363 | ||
4364 | userpg = rb->user_page; | |
4365 | ||
4366 | /* Allow new userspace to detect that bit 0 is deprecated */ | |
4367 | userpg->cap_bit0_is_deprecated = 1; | |
4368 | userpg->size = offsetof(struct perf_event_mmap_page, __reserved); | |
e8c6deac AS |
4369 | userpg->data_offset = PAGE_SIZE; |
4370 | userpg->data_size = perf_data_size(rb); | |
fa731587 PZ |
4371 | |
4372 | unlock: | |
4373 | rcu_read_unlock(); | |
4374 | } | |
4375 | ||
c1317ec2 AL |
4376 | void __weak arch_perf_update_userpage( |
4377 | struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) | |
e3f3541c PZ |
4378 | { |
4379 | } | |
4380 | ||
38ff667b PZ |
4381 | /* |
4382 | * Callers need to ensure there can be no nesting of this function, otherwise | |
4383 | * the seqlock logic goes bad. We can not serialize this because the arch | |
4384 | * code calls this from NMI context. | |
4385 | */ | |
cdd6c482 | 4386 | void perf_event_update_userpage(struct perf_event *event) |
37d81828 | 4387 | { |
cdd6c482 | 4388 | struct perf_event_mmap_page *userpg; |
76369139 | 4389 | struct ring_buffer *rb; |
e3f3541c | 4390 | u64 enabled, running, now; |
38ff667b PZ |
4391 | |
4392 | rcu_read_lock(); | |
5ec4c599 PZ |
4393 | rb = rcu_dereference(event->rb); |
4394 | if (!rb) | |
4395 | goto unlock; | |
4396 | ||
0d641208 EM |
4397 | /* |
4398 | * compute total_time_enabled, total_time_running | |
4399 | * based on snapshot values taken when the event | |
4400 | * was last scheduled in. | |
4401 | * | |
4402 | * we cannot simply called update_context_time() | |
4403 | * because of locking issue as we can be called in | |
4404 | * NMI context | |
4405 | */ | |
e3f3541c | 4406 | calc_timer_values(event, &now, &enabled, &running); |
38ff667b | 4407 | |
76369139 | 4408 | userpg = rb->user_page; |
7b732a75 PZ |
4409 | /* |
4410 | * Disable preemption so as to not let the corresponding user-space | |
4411 | * spin too long if we get preempted. | |
4412 | */ | |
4413 | preempt_disable(); | |
37d81828 | 4414 | ++userpg->lock; |
92f22a38 | 4415 | barrier(); |
cdd6c482 | 4416 | userpg->index = perf_event_index(event); |
b5e58793 | 4417 | userpg->offset = perf_event_count(event); |
365a4038 | 4418 | if (userpg->index) |
e7850595 | 4419 | userpg->offset -= local64_read(&event->hw.prev_count); |
7b732a75 | 4420 | |
0d641208 | 4421 | userpg->time_enabled = enabled + |
cdd6c482 | 4422 | atomic64_read(&event->child_total_time_enabled); |
7f8b4e4e | 4423 | |
0d641208 | 4424 | userpg->time_running = running + |
cdd6c482 | 4425 | atomic64_read(&event->child_total_time_running); |
7f8b4e4e | 4426 | |
c1317ec2 | 4427 | arch_perf_update_userpage(event, userpg, now); |
e3f3541c | 4428 | |
92f22a38 | 4429 | barrier(); |
37d81828 | 4430 | ++userpg->lock; |
7b732a75 | 4431 | preempt_enable(); |
38ff667b | 4432 | unlock: |
7b732a75 | 4433 | rcu_read_unlock(); |
37d81828 PM |
4434 | } |
4435 | ||
906010b2 PZ |
4436 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
4437 | { | |
4438 | struct perf_event *event = vma->vm_file->private_data; | |
76369139 | 4439 | struct ring_buffer *rb; |
906010b2 PZ |
4440 | int ret = VM_FAULT_SIGBUS; |
4441 | ||
4442 | if (vmf->flags & FAULT_FLAG_MKWRITE) { | |
4443 | if (vmf->pgoff == 0) | |
4444 | ret = 0; | |
4445 | return ret; | |
4446 | } | |
4447 | ||
4448 | rcu_read_lock(); | |
76369139 FW |
4449 | rb = rcu_dereference(event->rb); |
4450 | if (!rb) | |
906010b2 PZ |
4451 | goto unlock; |
4452 | ||
4453 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) | |
4454 | goto unlock; | |
4455 | ||
76369139 | 4456 | vmf->page = perf_mmap_to_page(rb, vmf->pgoff); |
906010b2 PZ |
4457 | if (!vmf->page) |
4458 | goto unlock; | |
4459 | ||
4460 | get_page(vmf->page); | |
4461 | vmf->page->mapping = vma->vm_file->f_mapping; | |
4462 | vmf->page->index = vmf->pgoff; | |
4463 | ||
4464 | ret = 0; | |
4465 | unlock: | |
4466 | rcu_read_unlock(); | |
4467 | ||
4468 | return ret; | |
4469 | } | |
4470 | ||
10c6db11 PZ |
4471 | static void ring_buffer_attach(struct perf_event *event, |
4472 | struct ring_buffer *rb) | |
4473 | { | |
b69cf536 | 4474 | struct ring_buffer *old_rb = NULL; |
10c6db11 PZ |
4475 | unsigned long flags; |
4476 | ||
b69cf536 PZ |
4477 | if (event->rb) { |
4478 | /* | |
4479 | * Should be impossible, we set this when removing | |
4480 | * event->rb_entry and wait/clear when adding event->rb_entry. | |
4481 | */ | |
4482 | WARN_ON_ONCE(event->rcu_pending); | |
10c6db11 | 4483 | |
b69cf536 | 4484 | old_rb = event->rb; |
b69cf536 PZ |
4485 | spin_lock_irqsave(&old_rb->event_lock, flags); |
4486 | list_del_rcu(&event->rb_entry); | |
4487 | spin_unlock_irqrestore(&old_rb->event_lock, flags); | |
10c6db11 | 4488 | |
2f993cf0 ON |
4489 | event->rcu_batches = get_state_synchronize_rcu(); |
4490 | event->rcu_pending = 1; | |
b69cf536 | 4491 | } |
10c6db11 | 4492 | |
b69cf536 | 4493 | if (rb) { |
2f993cf0 ON |
4494 | if (event->rcu_pending) { |
4495 | cond_synchronize_rcu(event->rcu_batches); | |
4496 | event->rcu_pending = 0; | |
4497 | } | |
4498 | ||
b69cf536 PZ |
4499 | spin_lock_irqsave(&rb->event_lock, flags); |
4500 | list_add_rcu(&event->rb_entry, &rb->event_list); | |
4501 | spin_unlock_irqrestore(&rb->event_lock, flags); | |
4502 | } | |
4503 | ||
4504 | rcu_assign_pointer(event->rb, rb); | |
4505 | ||
4506 | if (old_rb) { | |
4507 | ring_buffer_put(old_rb); | |
4508 | /* | |
4509 | * Since we detached before setting the new rb, so that we | |
4510 | * could attach the new rb, we could have missed a wakeup. | |
4511 | * Provide it now. | |
4512 | */ | |
4513 | wake_up_all(&event->waitq); | |
4514 | } | |
10c6db11 PZ |
4515 | } |
4516 | ||
4517 | static void ring_buffer_wakeup(struct perf_event *event) | |
4518 | { | |
4519 | struct ring_buffer *rb; | |
4520 | ||
4521 | rcu_read_lock(); | |
4522 | rb = rcu_dereference(event->rb); | |
9bb5d40c PZ |
4523 | if (rb) { |
4524 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) | |
4525 | wake_up_all(&event->waitq); | |
4526 | } | |
10c6db11 PZ |
4527 | rcu_read_unlock(); |
4528 | } | |
4529 | ||
fdc26706 | 4530 | struct ring_buffer *ring_buffer_get(struct perf_event *event) |
7b732a75 | 4531 | { |
76369139 | 4532 | struct ring_buffer *rb; |
7b732a75 | 4533 | |
ac9721f3 | 4534 | rcu_read_lock(); |
76369139 FW |
4535 | rb = rcu_dereference(event->rb); |
4536 | if (rb) { | |
4537 | if (!atomic_inc_not_zero(&rb->refcount)) | |
4538 | rb = NULL; | |
ac9721f3 PZ |
4539 | } |
4540 | rcu_read_unlock(); | |
4541 | ||
76369139 | 4542 | return rb; |
ac9721f3 PZ |
4543 | } |
4544 | ||
fdc26706 | 4545 | void ring_buffer_put(struct ring_buffer *rb) |
ac9721f3 | 4546 | { |
76369139 | 4547 | if (!atomic_dec_and_test(&rb->refcount)) |
ac9721f3 | 4548 | return; |
7b732a75 | 4549 | |
9bb5d40c | 4550 | WARN_ON_ONCE(!list_empty(&rb->event_list)); |
10c6db11 | 4551 | |
76369139 | 4552 | call_rcu(&rb->rcu_head, rb_free_rcu); |
7b732a75 PZ |
4553 | } |
4554 | ||
4555 | static void perf_mmap_open(struct vm_area_struct *vma) | |
4556 | { | |
cdd6c482 | 4557 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4558 | |
cdd6c482 | 4559 | atomic_inc(&event->mmap_count); |
9bb5d40c | 4560 | atomic_inc(&event->rb->mmap_count); |
1e0fb9ec | 4561 | |
45bfb2e5 PZ |
4562 | if (vma->vm_pgoff) |
4563 | atomic_inc(&event->rb->aux_mmap_count); | |
4564 | ||
1e0fb9ec AL |
4565 | if (event->pmu->event_mapped) |
4566 | event->pmu->event_mapped(event); | |
7b732a75 PZ |
4567 | } |
4568 | ||
9bb5d40c PZ |
4569 | /* |
4570 | * A buffer can be mmap()ed multiple times; either directly through the same | |
4571 | * event, or through other events by use of perf_event_set_output(). | |
4572 | * | |
4573 | * In order to undo the VM accounting done by perf_mmap() we need to destroy | |
4574 | * the buffer here, where we still have a VM context. This means we need | |
4575 | * to detach all events redirecting to us. | |
4576 | */ | |
7b732a75 PZ |
4577 | static void perf_mmap_close(struct vm_area_struct *vma) |
4578 | { | |
cdd6c482 | 4579 | struct perf_event *event = vma->vm_file->private_data; |
7b732a75 | 4580 | |
b69cf536 | 4581 | struct ring_buffer *rb = ring_buffer_get(event); |
9bb5d40c PZ |
4582 | struct user_struct *mmap_user = rb->mmap_user; |
4583 | int mmap_locked = rb->mmap_locked; | |
4584 | unsigned long size = perf_data_size(rb); | |
789f90fc | 4585 | |
1e0fb9ec AL |
4586 | if (event->pmu->event_unmapped) |
4587 | event->pmu->event_unmapped(event); | |
4588 | ||
45bfb2e5 PZ |
4589 | /* |
4590 | * rb->aux_mmap_count will always drop before rb->mmap_count and | |
4591 | * event->mmap_count, so it is ok to use event->mmap_mutex to | |
4592 | * serialize with perf_mmap here. | |
4593 | */ | |
4594 | if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && | |
4595 | atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) { | |
4596 | atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); | |
4597 | vma->vm_mm->pinned_vm -= rb->aux_mmap_locked; | |
4598 | ||
4599 | rb_free_aux(rb); | |
4600 | mutex_unlock(&event->mmap_mutex); | |
4601 | } | |
4602 | ||
9bb5d40c PZ |
4603 | atomic_dec(&rb->mmap_count); |
4604 | ||
4605 | if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) | |
b69cf536 | 4606 | goto out_put; |
9bb5d40c | 4607 | |
b69cf536 | 4608 | ring_buffer_attach(event, NULL); |
9bb5d40c PZ |
4609 | mutex_unlock(&event->mmap_mutex); |
4610 | ||
4611 | /* If there's still other mmap()s of this buffer, we're done. */ | |
b69cf536 PZ |
4612 | if (atomic_read(&rb->mmap_count)) |
4613 | goto out_put; | |
ac9721f3 | 4614 | |
9bb5d40c PZ |
4615 | /* |
4616 | * No other mmap()s, detach from all other events that might redirect | |
4617 | * into the now unreachable buffer. Somewhat complicated by the | |
4618 | * fact that rb::event_lock otherwise nests inside mmap_mutex. | |
4619 | */ | |
4620 | again: | |
4621 | rcu_read_lock(); | |
4622 | list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { | |
4623 | if (!atomic_long_inc_not_zero(&event->refcount)) { | |
4624 | /* | |
4625 | * This event is en-route to free_event() which will | |
4626 | * detach it and remove it from the list. | |
4627 | */ | |
4628 | continue; | |
4629 | } | |
4630 | rcu_read_unlock(); | |
789f90fc | 4631 | |
9bb5d40c PZ |
4632 | mutex_lock(&event->mmap_mutex); |
4633 | /* | |
4634 | * Check we didn't race with perf_event_set_output() which can | |
4635 | * swizzle the rb from under us while we were waiting to | |
4636 | * acquire mmap_mutex. | |
4637 | * | |
4638 | * If we find a different rb; ignore this event, a next | |
4639 | * iteration will no longer find it on the list. We have to | |
4640 | * still restart the iteration to make sure we're not now | |
4641 | * iterating the wrong list. | |
4642 | */ | |
b69cf536 PZ |
4643 | if (event->rb == rb) |
4644 | ring_buffer_attach(event, NULL); | |
4645 | ||
cdd6c482 | 4646 | mutex_unlock(&event->mmap_mutex); |
9bb5d40c | 4647 | put_event(event); |
ac9721f3 | 4648 | |
9bb5d40c PZ |
4649 | /* |
4650 | * Restart the iteration; either we're on the wrong list or | |
4651 | * destroyed its integrity by doing a deletion. | |
4652 | */ | |
4653 | goto again; | |
7b732a75 | 4654 | } |
9bb5d40c PZ |
4655 | rcu_read_unlock(); |
4656 | ||
4657 | /* | |
4658 | * It could be there's still a few 0-ref events on the list; they'll | |
4659 | * get cleaned up by free_event() -- they'll also still have their | |
4660 | * ref on the rb and will free it whenever they are done with it. | |
4661 | * | |
4662 | * Aside from that, this buffer is 'fully' detached and unmapped, | |
4663 | * undo the VM accounting. | |
4664 | */ | |
4665 | ||
4666 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm); | |
4667 | vma->vm_mm->pinned_vm -= mmap_locked; | |
4668 | free_uid(mmap_user); | |
4669 | ||
b69cf536 | 4670 | out_put: |
9bb5d40c | 4671 | ring_buffer_put(rb); /* could be last */ |
37d81828 PM |
4672 | } |
4673 | ||
f0f37e2f | 4674 | static const struct vm_operations_struct perf_mmap_vmops = { |
43a21ea8 | 4675 | .open = perf_mmap_open, |
45bfb2e5 | 4676 | .close = perf_mmap_close, /* non mergable */ |
43a21ea8 PZ |
4677 | .fault = perf_mmap_fault, |
4678 | .page_mkwrite = perf_mmap_fault, | |
37d81828 PM |
4679 | }; |
4680 | ||
4681 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) | |
4682 | { | |
cdd6c482 | 4683 | struct perf_event *event = file->private_data; |
22a4f650 | 4684 | unsigned long user_locked, user_lock_limit; |
789f90fc | 4685 | struct user_struct *user = current_user(); |
22a4f650 | 4686 | unsigned long locked, lock_limit; |
45bfb2e5 | 4687 | struct ring_buffer *rb = NULL; |
7b732a75 PZ |
4688 | unsigned long vma_size; |
4689 | unsigned long nr_pages; | |
45bfb2e5 | 4690 | long user_extra = 0, extra = 0; |
d57e34fd | 4691 | int ret = 0, flags = 0; |
37d81828 | 4692 | |
c7920614 PZ |
4693 | /* |
4694 | * Don't allow mmap() of inherited per-task counters. This would | |
4695 | * create a performance issue due to all children writing to the | |
76369139 | 4696 | * same rb. |
c7920614 PZ |
4697 | */ |
4698 | if (event->cpu == -1 && event->attr.inherit) | |
4699 | return -EINVAL; | |
4700 | ||
43a21ea8 | 4701 | if (!(vma->vm_flags & VM_SHARED)) |
37d81828 | 4702 | return -EINVAL; |
7b732a75 PZ |
4703 | |
4704 | vma_size = vma->vm_end - vma->vm_start; | |
45bfb2e5 PZ |
4705 | |
4706 | if (vma->vm_pgoff == 0) { | |
4707 | nr_pages = (vma_size / PAGE_SIZE) - 1; | |
4708 | } else { | |
4709 | /* | |
4710 | * AUX area mapping: if rb->aux_nr_pages != 0, it's already | |
4711 | * mapped, all subsequent mappings should have the same size | |
4712 | * and offset. Must be above the normal perf buffer. | |
4713 | */ | |
4714 | u64 aux_offset, aux_size; | |
4715 | ||
4716 | if (!event->rb) | |
4717 | return -EINVAL; | |
4718 | ||
4719 | nr_pages = vma_size / PAGE_SIZE; | |
4720 | ||
4721 | mutex_lock(&event->mmap_mutex); | |
4722 | ret = -EINVAL; | |
4723 | ||
4724 | rb = event->rb; | |
4725 | if (!rb) | |
4726 | goto aux_unlock; | |
4727 | ||
4728 | aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); | |
4729 | aux_size = ACCESS_ONCE(rb->user_page->aux_size); | |
4730 | ||
4731 | if (aux_offset < perf_data_size(rb) + PAGE_SIZE) | |
4732 | goto aux_unlock; | |
4733 | ||
4734 | if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) | |
4735 | goto aux_unlock; | |
4736 | ||
4737 | /* already mapped with a different offset */ | |
4738 | if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) | |
4739 | goto aux_unlock; | |
4740 | ||
4741 | if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE) | |
4742 | goto aux_unlock; | |
4743 | ||
4744 | /* already mapped with a different size */ | |
4745 | if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) | |
4746 | goto aux_unlock; | |
4747 | ||
4748 | if (!is_power_of_2(nr_pages)) | |
4749 | goto aux_unlock; | |
4750 | ||
4751 | if (!atomic_inc_not_zero(&rb->mmap_count)) | |
4752 | goto aux_unlock; | |
4753 | ||
4754 | if (rb_has_aux(rb)) { | |
4755 | atomic_inc(&rb->aux_mmap_count); | |
4756 | ret = 0; | |
4757 | goto unlock; | |
4758 | } | |
4759 | ||
4760 | atomic_set(&rb->aux_mmap_count, 1); | |
4761 | user_extra = nr_pages; | |
4762 | ||
4763 | goto accounting; | |
4764 | } | |
7b732a75 | 4765 | |
7730d865 | 4766 | /* |
76369139 | 4767 | * If we have rb pages ensure they're a power-of-two number, so we |
7730d865 PZ |
4768 | * can do bitmasks instead of modulo. |
4769 | */ | |
2ed11312 | 4770 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
37d81828 PM |
4771 | return -EINVAL; |
4772 | ||
7b732a75 | 4773 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
37d81828 PM |
4774 | return -EINVAL; |
4775 | ||
cdd6c482 | 4776 | WARN_ON_ONCE(event->ctx->parent_ctx); |
9bb5d40c | 4777 | again: |
cdd6c482 | 4778 | mutex_lock(&event->mmap_mutex); |
76369139 | 4779 | if (event->rb) { |
9bb5d40c | 4780 | if (event->rb->nr_pages != nr_pages) { |
ebb3c4c4 | 4781 | ret = -EINVAL; |
9bb5d40c PZ |
4782 | goto unlock; |
4783 | } | |
4784 | ||
4785 | if (!atomic_inc_not_zero(&event->rb->mmap_count)) { | |
4786 | /* | |
4787 | * Raced against perf_mmap_close() through | |
4788 | * perf_event_set_output(). Try again, hope for better | |
4789 | * luck. | |
4790 | */ | |
4791 | mutex_unlock(&event->mmap_mutex); | |
4792 | goto again; | |
4793 | } | |
4794 | ||
ebb3c4c4 PZ |
4795 | goto unlock; |
4796 | } | |
4797 | ||
789f90fc | 4798 | user_extra = nr_pages + 1; |
45bfb2e5 PZ |
4799 | |
4800 | accounting: | |
cdd6c482 | 4801 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
a3862d3f IM |
4802 | |
4803 | /* | |
4804 | * Increase the limit linearly with more CPUs: | |
4805 | */ | |
4806 | user_lock_limit *= num_online_cpus(); | |
4807 | ||
789f90fc | 4808 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
c5078f78 | 4809 | |
789f90fc PZ |
4810 | if (user_locked > user_lock_limit) |
4811 | extra = user_locked - user_lock_limit; | |
7b732a75 | 4812 | |
78d7d407 | 4813 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
7b732a75 | 4814 | lock_limit >>= PAGE_SHIFT; |
bc3e53f6 | 4815 | locked = vma->vm_mm->pinned_vm + extra; |
7b732a75 | 4816 | |
459ec28a IM |
4817 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
4818 | !capable(CAP_IPC_LOCK)) { | |
ebb3c4c4 PZ |
4819 | ret = -EPERM; |
4820 | goto unlock; | |
4821 | } | |
7b732a75 | 4822 | |
45bfb2e5 | 4823 | WARN_ON(!rb && event->rb); |
906010b2 | 4824 | |
d57e34fd | 4825 | if (vma->vm_flags & VM_WRITE) |
76369139 | 4826 | flags |= RING_BUFFER_WRITABLE; |
d57e34fd | 4827 | |
76369139 | 4828 | if (!rb) { |
45bfb2e5 PZ |
4829 | rb = rb_alloc(nr_pages, |
4830 | event->attr.watermark ? event->attr.wakeup_watermark : 0, | |
4831 | event->cpu, flags); | |
26cb63ad | 4832 | |
45bfb2e5 PZ |
4833 | if (!rb) { |
4834 | ret = -ENOMEM; | |
4835 | goto unlock; | |
4836 | } | |
43a21ea8 | 4837 | |
45bfb2e5 PZ |
4838 | atomic_set(&rb->mmap_count, 1); |
4839 | rb->mmap_user = get_current_user(); | |
4840 | rb->mmap_locked = extra; | |
26cb63ad | 4841 | |
45bfb2e5 | 4842 | ring_buffer_attach(event, rb); |
ac9721f3 | 4843 | |
45bfb2e5 PZ |
4844 | perf_event_init_userpage(event); |
4845 | perf_event_update_userpage(event); | |
4846 | } else { | |
1a594131 AS |
4847 | ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, |
4848 | event->attr.aux_watermark, flags); | |
45bfb2e5 PZ |
4849 | if (!ret) |
4850 | rb->aux_mmap_locked = extra; | |
4851 | } | |
9a0f05cb | 4852 | |
ebb3c4c4 | 4853 | unlock: |
45bfb2e5 PZ |
4854 | if (!ret) { |
4855 | atomic_long_add(user_extra, &user->locked_vm); | |
4856 | vma->vm_mm->pinned_vm += extra; | |
4857 | ||
ac9721f3 | 4858 | atomic_inc(&event->mmap_count); |
45bfb2e5 PZ |
4859 | } else if (rb) { |
4860 | atomic_dec(&rb->mmap_count); | |
4861 | } | |
4862 | aux_unlock: | |
cdd6c482 | 4863 | mutex_unlock(&event->mmap_mutex); |
37d81828 | 4864 | |
9bb5d40c PZ |
4865 | /* |
4866 | * Since pinned accounting is per vm we cannot allow fork() to copy our | |
4867 | * vma. | |
4868 | */ | |
26cb63ad | 4869 | vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; |
37d81828 | 4870 | vma->vm_ops = &perf_mmap_vmops; |
7b732a75 | 4871 | |
1e0fb9ec AL |
4872 | if (event->pmu->event_mapped) |
4873 | event->pmu->event_mapped(event); | |
4874 | ||
7b732a75 | 4875 | return ret; |
37d81828 PM |
4876 | } |
4877 | ||
3c446b3d PZ |
4878 | static int perf_fasync(int fd, struct file *filp, int on) |
4879 | { | |
496ad9aa | 4880 | struct inode *inode = file_inode(filp); |
cdd6c482 | 4881 | struct perf_event *event = filp->private_data; |
3c446b3d PZ |
4882 | int retval; |
4883 | ||
4884 | mutex_lock(&inode->i_mutex); | |
cdd6c482 | 4885 | retval = fasync_helper(fd, filp, on, &event->fasync); |
3c446b3d PZ |
4886 | mutex_unlock(&inode->i_mutex); |
4887 | ||
4888 | if (retval < 0) | |
4889 | return retval; | |
4890 | ||
4891 | return 0; | |
4892 | } | |
4893 | ||
0793a61d | 4894 | static const struct file_operations perf_fops = { |
3326c1ce | 4895 | .llseek = no_llseek, |
0793a61d TG |
4896 | .release = perf_release, |
4897 | .read = perf_read, | |
4898 | .poll = perf_poll, | |
d859e29f | 4899 | .unlocked_ioctl = perf_ioctl, |
b3f20785 | 4900 | .compat_ioctl = perf_compat_ioctl, |
37d81828 | 4901 | .mmap = perf_mmap, |
3c446b3d | 4902 | .fasync = perf_fasync, |
0793a61d TG |
4903 | }; |
4904 | ||
925d519a | 4905 | /* |
cdd6c482 | 4906 | * Perf event wakeup |
925d519a PZ |
4907 | * |
4908 | * If there's data, ensure we set the poll() state and publish everything | |
4909 | * to user-space before waking everybody up. | |
4910 | */ | |
4911 | ||
fed66e2c PZ |
4912 | static inline struct fasync_struct **perf_event_fasync(struct perf_event *event) |
4913 | { | |
4914 | /* only the parent has fasync state */ | |
4915 | if (event->parent) | |
4916 | event = event->parent; | |
4917 | return &event->fasync; | |
4918 | } | |
4919 | ||
cdd6c482 | 4920 | void perf_event_wakeup(struct perf_event *event) |
925d519a | 4921 | { |
10c6db11 | 4922 | ring_buffer_wakeup(event); |
4c9e2542 | 4923 | |
cdd6c482 | 4924 | if (event->pending_kill) { |
fed66e2c | 4925 | kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); |
cdd6c482 | 4926 | event->pending_kill = 0; |
4c9e2542 | 4927 | } |
925d519a PZ |
4928 | } |
4929 | ||
e360adbe | 4930 | static void perf_pending_event(struct irq_work *entry) |
79f14641 | 4931 | { |
cdd6c482 IM |
4932 | struct perf_event *event = container_of(entry, |
4933 | struct perf_event, pending); | |
d525211f PZ |
4934 | int rctx; |
4935 | ||
4936 | rctx = perf_swevent_get_recursion_context(); | |
4937 | /* | |
4938 | * If we 'fail' here, that's OK, it means recursion is already disabled | |
4939 | * and we won't recurse 'further'. | |
4940 | */ | |
79f14641 | 4941 | |
cdd6c482 IM |
4942 | if (event->pending_disable) { |
4943 | event->pending_disable = 0; | |
4944 | __perf_event_disable(event); | |
79f14641 PZ |
4945 | } |
4946 | ||
cdd6c482 IM |
4947 | if (event->pending_wakeup) { |
4948 | event->pending_wakeup = 0; | |
4949 | perf_event_wakeup(event); | |
79f14641 | 4950 | } |
d525211f PZ |
4951 | |
4952 | if (rctx >= 0) | |
4953 | perf_swevent_put_recursion_context(rctx); | |
79f14641 PZ |
4954 | } |
4955 | ||
39447b38 ZY |
4956 | /* |
4957 | * We assume there is only KVM supporting the callbacks. | |
4958 | * Later on, we might change it to a list if there is | |
4959 | * another virtualization implementation supporting the callbacks. | |
4960 | */ | |
4961 | struct perf_guest_info_callbacks *perf_guest_cbs; | |
4962 | ||
4963 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4964 | { | |
4965 | perf_guest_cbs = cbs; | |
4966 | return 0; | |
4967 | } | |
4968 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); | |
4969 | ||
4970 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) | |
4971 | { | |
4972 | perf_guest_cbs = NULL; | |
4973 | return 0; | |
4974 | } | |
4975 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); | |
4976 | ||
4018994f JO |
4977 | static void |
4978 | perf_output_sample_regs(struct perf_output_handle *handle, | |
4979 | struct pt_regs *regs, u64 mask) | |
4980 | { | |
4981 | int bit; | |
4982 | ||
4983 | for_each_set_bit(bit, (const unsigned long *) &mask, | |
4984 | sizeof(mask) * BITS_PER_BYTE) { | |
4985 | u64 val; | |
4986 | ||
4987 | val = perf_reg_value(regs, bit); | |
4988 | perf_output_put(handle, val); | |
4989 | } | |
4990 | } | |
4991 | ||
60e2364e | 4992 | static void perf_sample_regs_user(struct perf_regs *regs_user, |
88a7c26a AL |
4993 | struct pt_regs *regs, |
4994 | struct pt_regs *regs_user_copy) | |
4018994f | 4995 | { |
88a7c26a AL |
4996 | if (user_mode(regs)) { |
4997 | regs_user->abi = perf_reg_abi(current); | |
2565711f | 4998 | regs_user->regs = regs; |
88a7c26a AL |
4999 | } else if (current->mm) { |
5000 | perf_get_regs_user(regs_user, regs, regs_user_copy); | |
2565711f PZ |
5001 | } else { |
5002 | regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; | |
5003 | regs_user->regs = NULL; | |
4018994f JO |
5004 | } |
5005 | } | |
5006 | ||
60e2364e SE |
5007 | static void perf_sample_regs_intr(struct perf_regs *regs_intr, |
5008 | struct pt_regs *regs) | |
5009 | { | |
5010 | regs_intr->regs = regs; | |
5011 | regs_intr->abi = perf_reg_abi(current); | |
5012 | } | |
5013 | ||
5014 | ||
c5ebcedb JO |
5015 | /* |
5016 | * Get remaining task size from user stack pointer. | |
5017 | * | |
5018 | * It'd be better to take stack vma map and limit this more | |
5019 | * precisly, but there's no way to get it safely under interrupt, | |
5020 | * so using TASK_SIZE as limit. | |
5021 | */ | |
5022 | static u64 perf_ustack_task_size(struct pt_regs *regs) | |
5023 | { | |
5024 | unsigned long addr = perf_user_stack_pointer(regs); | |
5025 | ||
5026 | if (!addr || addr >= TASK_SIZE) | |
5027 | return 0; | |
5028 | ||
5029 | return TASK_SIZE - addr; | |
5030 | } | |
5031 | ||
5032 | static u16 | |
5033 | perf_sample_ustack_size(u16 stack_size, u16 header_size, | |
5034 | struct pt_regs *regs) | |
5035 | { | |
5036 | u64 task_size; | |
5037 | ||
5038 | /* No regs, no stack pointer, no dump. */ | |
5039 | if (!regs) | |
5040 | return 0; | |
5041 | ||
5042 | /* | |
5043 | * Check if we fit in with the requested stack size into the: | |
5044 | * - TASK_SIZE | |
5045 | * If we don't, we limit the size to the TASK_SIZE. | |
5046 | * | |
5047 | * - remaining sample size | |
5048 | * If we don't, we customize the stack size to | |
5049 | * fit in to the remaining sample size. | |
5050 | */ | |
5051 | ||
5052 | task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); | |
5053 | stack_size = min(stack_size, (u16) task_size); | |
5054 | ||
5055 | /* Current header size plus static size and dynamic size. */ | |
5056 | header_size += 2 * sizeof(u64); | |
5057 | ||
5058 | /* Do we fit in with the current stack dump size? */ | |
5059 | if ((u16) (header_size + stack_size) < header_size) { | |
5060 | /* | |
5061 | * If we overflow the maximum size for the sample, | |
5062 | * we customize the stack dump size to fit in. | |
5063 | */ | |
5064 | stack_size = USHRT_MAX - header_size - sizeof(u64); | |
5065 | stack_size = round_up(stack_size, sizeof(u64)); | |
5066 | } | |
5067 | ||
5068 | return stack_size; | |
5069 | } | |
5070 | ||
5071 | static void | |
5072 | perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, | |
5073 | struct pt_regs *regs) | |
5074 | { | |
5075 | /* Case of a kernel thread, nothing to dump */ | |
5076 | if (!regs) { | |
5077 | u64 size = 0; | |
5078 | perf_output_put(handle, size); | |
5079 | } else { | |
5080 | unsigned long sp; | |
5081 | unsigned int rem; | |
5082 | u64 dyn_size; | |
5083 | ||
5084 | /* | |
5085 | * We dump: | |
5086 | * static size | |
5087 | * - the size requested by user or the best one we can fit | |
5088 | * in to the sample max size | |
5089 | * data | |
5090 | * - user stack dump data | |
5091 | * dynamic size | |
5092 | * - the actual dumped size | |
5093 | */ | |
5094 | ||
5095 | /* Static size. */ | |
5096 | perf_output_put(handle, dump_size); | |
5097 | ||
5098 | /* Data. */ | |
5099 | sp = perf_user_stack_pointer(regs); | |
5100 | rem = __output_copy_user(handle, (void *) sp, dump_size); | |
5101 | dyn_size = dump_size - rem; | |
5102 | ||
5103 | perf_output_skip(handle, rem); | |
5104 | ||
5105 | /* Dynamic size. */ | |
5106 | perf_output_put(handle, dyn_size); | |
5107 | } | |
5108 | } | |
5109 | ||
c980d109 ACM |
5110 | static void __perf_event_header__init_id(struct perf_event_header *header, |
5111 | struct perf_sample_data *data, | |
5112 | struct perf_event *event) | |
6844c09d ACM |
5113 | { |
5114 | u64 sample_type = event->attr.sample_type; | |
5115 | ||
5116 | data->type = sample_type; | |
5117 | header->size += event->id_header_size; | |
5118 | ||
5119 | if (sample_type & PERF_SAMPLE_TID) { | |
5120 | /* namespace issues */ | |
5121 | data->tid_entry.pid = perf_event_pid(event, current); | |
5122 | data->tid_entry.tid = perf_event_tid(event, current); | |
5123 | } | |
5124 | ||
5125 | if (sample_type & PERF_SAMPLE_TIME) | |
34f43927 | 5126 | data->time = perf_event_clock(event); |
6844c09d | 5127 | |
ff3d527c | 5128 | if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) |
6844c09d ACM |
5129 | data->id = primary_event_id(event); |
5130 | ||
5131 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5132 | data->stream_id = event->id; | |
5133 | ||
5134 | if (sample_type & PERF_SAMPLE_CPU) { | |
5135 | data->cpu_entry.cpu = raw_smp_processor_id(); | |
5136 | data->cpu_entry.reserved = 0; | |
5137 | } | |
5138 | } | |
5139 | ||
76369139 FW |
5140 | void perf_event_header__init_id(struct perf_event_header *header, |
5141 | struct perf_sample_data *data, | |
5142 | struct perf_event *event) | |
c980d109 ACM |
5143 | { |
5144 | if (event->attr.sample_id_all) | |
5145 | __perf_event_header__init_id(header, data, event); | |
5146 | } | |
5147 | ||
5148 | static void __perf_event__output_id_sample(struct perf_output_handle *handle, | |
5149 | struct perf_sample_data *data) | |
5150 | { | |
5151 | u64 sample_type = data->type; | |
5152 | ||
5153 | if (sample_type & PERF_SAMPLE_TID) | |
5154 | perf_output_put(handle, data->tid_entry); | |
5155 | ||
5156 | if (sample_type & PERF_SAMPLE_TIME) | |
5157 | perf_output_put(handle, data->time); | |
5158 | ||
5159 | if (sample_type & PERF_SAMPLE_ID) | |
5160 | perf_output_put(handle, data->id); | |
5161 | ||
5162 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5163 | perf_output_put(handle, data->stream_id); | |
5164 | ||
5165 | if (sample_type & PERF_SAMPLE_CPU) | |
5166 | perf_output_put(handle, data->cpu_entry); | |
ff3d527c AH |
5167 | |
5168 | if (sample_type & PERF_SAMPLE_IDENTIFIER) | |
5169 | perf_output_put(handle, data->id); | |
c980d109 ACM |
5170 | } |
5171 | ||
76369139 FW |
5172 | void perf_event__output_id_sample(struct perf_event *event, |
5173 | struct perf_output_handle *handle, | |
5174 | struct perf_sample_data *sample) | |
c980d109 ACM |
5175 | { |
5176 | if (event->attr.sample_id_all) | |
5177 | __perf_event__output_id_sample(handle, sample); | |
5178 | } | |
5179 | ||
3dab77fb | 5180 | static void perf_output_read_one(struct perf_output_handle *handle, |
eed01528 SE |
5181 | struct perf_event *event, |
5182 | u64 enabled, u64 running) | |
3dab77fb | 5183 | { |
cdd6c482 | 5184 | u64 read_format = event->attr.read_format; |
3dab77fb PZ |
5185 | u64 values[4]; |
5186 | int n = 0; | |
5187 | ||
b5e58793 | 5188 | values[n++] = perf_event_count(event); |
3dab77fb | 5189 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
eed01528 | 5190 | values[n++] = enabled + |
cdd6c482 | 5191 | atomic64_read(&event->child_total_time_enabled); |
3dab77fb PZ |
5192 | } |
5193 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { | |
eed01528 | 5194 | values[n++] = running + |
cdd6c482 | 5195 | atomic64_read(&event->child_total_time_running); |
3dab77fb PZ |
5196 | } |
5197 | if (read_format & PERF_FORMAT_ID) | |
cdd6c482 | 5198 | values[n++] = primary_event_id(event); |
3dab77fb | 5199 | |
76369139 | 5200 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5201 | } |
5202 | ||
5203 | /* | |
cdd6c482 | 5204 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
3dab77fb PZ |
5205 | */ |
5206 | static void perf_output_read_group(struct perf_output_handle *handle, | |
eed01528 SE |
5207 | struct perf_event *event, |
5208 | u64 enabled, u64 running) | |
3dab77fb | 5209 | { |
cdd6c482 IM |
5210 | struct perf_event *leader = event->group_leader, *sub; |
5211 | u64 read_format = event->attr.read_format; | |
3dab77fb PZ |
5212 | u64 values[5]; |
5213 | int n = 0; | |
5214 | ||
5215 | values[n++] = 1 + leader->nr_siblings; | |
5216 | ||
5217 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) | |
eed01528 | 5218 | values[n++] = enabled; |
3dab77fb PZ |
5219 | |
5220 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) | |
eed01528 | 5221 | values[n++] = running; |
3dab77fb | 5222 | |
cdd6c482 | 5223 | if (leader != event) |
3dab77fb PZ |
5224 | leader->pmu->read(leader); |
5225 | ||
b5e58793 | 5226 | values[n++] = perf_event_count(leader); |
3dab77fb | 5227 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5228 | values[n++] = primary_event_id(leader); |
3dab77fb | 5229 | |
76369139 | 5230 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb | 5231 | |
65abc865 | 5232 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
3dab77fb PZ |
5233 | n = 0; |
5234 | ||
6f5ab001 JO |
5235 | if ((sub != event) && |
5236 | (sub->state == PERF_EVENT_STATE_ACTIVE)) | |
3dab77fb PZ |
5237 | sub->pmu->read(sub); |
5238 | ||
b5e58793 | 5239 | values[n++] = perf_event_count(sub); |
3dab77fb | 5240 | if (read_format & PERF_FORMAT_ID) |
cdd6c482 | 5241 | values[n++] = primary_event_id(sub); |
3dab77fb | 5242 | |
76369139 | 5243 | __output_copy(handle, values, n * sizeof(u64)); |
3dab77fb PZ |
5244 | } |
5245 | } | |
5246 | ||
eed01528 SE |
5247 | #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |
5248 | PERF_FORMAT_TOTAL_TIME_RUNNING) | |
5249 | ||
3dab77fb | 5250 | static void perf_output_read(struct perf_output_handle *handle, |
cdd6c482 | 5251 | struct perf_event *event) |
3dab77fb | 5252 | { |
e3f3541c | 5253 | u64 enabled = 0, running = 0, now; |
eed01528 SE |
5254 | u64 read_format = event->attr.read_format; |
5255 | ||
5256 | /* | |
5257 | * compute total_time_enabled, total_time_running | |
5258 | * based on snapshot values taken when the event | |
5259 | * was last scheduled in. | |
5260 | * | |
5261 | * we cannot simply called update_context_time() | |
5262 | * because of locking issue as we are called in | |
5263 | * NMI context | |
5264 | */ | |
c4794295 | 5265 | if (read_format & PERF_FORMAT_TOTAL_TIMES) |
e3f3541c | 5266 | calc_timer_values(event, &now, &enabled, &running); |
eed01528 | 5267 | |
cdd6c482 | 5268 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
eed01528 | 5269 | perf_output_read_group(handle, event, enabled, running); |
3dab77fb | 5270 | else |
eed01528 | 5271 | perf_output_read_one(handle, event, enabled, running); |
3dab77fb PZ |
5272 | } |
5273 | ||
5622f295 MM |
5274 | void perf_output_sample(struct perf_output_handle *handle, |
5275 | struct perf_event_header *header, | |
5276 | struct perf_sample_data *data, | |
cdd6c482 | 5277 | struct perf_event *event) |
5622f295 MM |
5278 | { |
5279 | u64 sample_type = data->type; | |
5280 | ||
5281 | perf_output_put(handle, *header); | |
5282 | ||
ff3d527c AH |
5283 | if (sample_type & PERF_SAMPLE_IDENTIFIER) |
5284 | perf_output_put(handle, data->id); | |
5285 | ||
5622f295 MM |
5286 | if (sample_type & PERF_SAMPLE_IP) |
5287 | perf_output_put(handle, data->ip); | |
5288 | ||
5289 | if (sample_type & PERF_SAMPLE_TID) | |
5290 | perf_output_put(handle, data->tid_entry); | |
5291 | ||
5292 | if (sample_type & PERF_SAMPLE_TIME) | |
5293 | perf_output_put(handle, data->time); | |
5294 | ||
5295 | if (sample_type & PERF_SAMPLE_ADDR) | |
5296 | perf_output_put(handle, data->addr); | |
5297 | ||
5298 | if (sample_type & PERF_SAMPLE_ID) | |
5299 | perf_output_put(handle, data->id); | |
5300 | ||
5301 | if (sample_type & PERF_SAMPLE_STREAM_ID) | |
5302 | perf_output_put(handle, data->stream_id); | |
5303 | ||
5304 | if (sample_type & PERF_SAMPLE_CPU) | |
5305 | perf_output_put(handle, data->cpu_entry); | |
5306 | ||
5307 | if (sample_type & PERF_SAMPLE_PERIOD) | |
5308 | perf_output_put(handle, data->period); | |
5309 | ||
5310 | if (sample_type & PERF_SAMPLE_READ) | |
cdd6c482 | 5311 | perf_output_read(handle, event); |
5622f295 MM |
5312 | |
5313 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { | |
5314 | if (data->callchain) { | |
5315 | int size = 1; | |
5316 | ||
5317 | if (data->callchain) | |
5318 | size += data->callchain->nr; | |
5319 | ||
5320 | size *= sizeof(u64); | |
5321 | ||
76369139 | 5322 | __output_copy(handle, data->callchain, size); |
5622f295 MM |
5323 | } else { |
5324 | u64 nr = 0; | |
5325 | perf_output_put(handle, nr); | |
5326 | } | |
5327 | } | |
5328 | ||
5329 | if (sample_type & PERF_SAMPLE_RAW) { | |
5330 | if (data->raw) { | |
fa128e6a AS |
5331 | u32 raw_size = data->raw->size; |
5332 | u32 real_size = round_up(raw_size + sizeof(u32), | |
5333 | sizeof(u64)) - sizeof(u32); | |
5334 | u64 zero = 0; | |
5335 | ||
5336 | perf_output_put(handle, real_size); | |
5337 | __output_copy(handle, data->raw->data, raw_size); | |
5338 | if (real_size - raw_size) | |
5339 | __output_copy(handle, &zero, real_size - raw_size); | |
5622f295 MM |
5340 | } else { |
5341 | struct { | |
5342 | u32 size; | |
5343 | u32 data; | |
5344 | } raw = { | |
5345 | .size = sizeof(u32), | |
5346 | .data = 0, | |
5347 | }; | |
5348 | perf_output_put(handle, raw); | |
5349 | } | |
5350 | } | |
a7ac67ea | 5351 | |
bce38cd5 SE |
5352 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { |
5353 | if (data->br_stack) { | |
5354 | size_t size; | |
5355 | ||
5356 | size = data->br_stack->nr | |
5357 | * sizeof(struct perf_branch_entry); | |
5358 | ||
5359 | perf_output_put(handle, data->br_stack->nr); | |
5360 | perf_output_copy(handle, data->br_stack->entries, size); | |
5361 | } else { | |
5362 | /* | |
5363 | * we always store at least the value of nr | |
5364 | */ | |
5365 | u64 nr = 0; | |
5366 | perf_output_put(handle, nr); | |
5367 | } | |
5368 | } | |
4018994f JO |
5369 | |
5370 | if (sample_type & PERF_SAMPLE_REGS_USER) { | |
5371 | u64 abi = data->regs_user.abi; | |
5372 | ||
5373 | /* | |
5374 | * If there are no regs to dump, notice it through | |
5375 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5376 | */ | |
5377 | perf_output_put(handle, abi); | |
5378 | ||
5379 | if (abi) { | |
5380 | u64 mask = event->attr.sample_regs_user; | |
5381 | perf_output_sample_regs(handle, | |
5382 | data->regs_user.regs, | |
5383 | mask); | |
5384 | } | |
5385 | } | |
c5ebcedb | 5386 | |
a5cdd40c | 5387 | if (sample_type & PERF_SAMPLE_STACK_USER) { |
c5ebcedb JO |
5388 | perf_output_sample_ustack(handle, |
5389 | data->stack_user_size, | |
5390 | data->regs_user.regs); | |
a5cdd40c | 5391 | } |
c3feedf2 AK |
5392 | |
5393 | if (sample_type & PERF_SAMPLE_WEIGHT) | |
5394 | perf_output_put(handle, data->weight); | |
d6be9ad6 SE |
5395 | |
5396 | if (sample_type & PERF_SAMPLE_DATA_SRC) | |
5397 | perf_output_put(handle, data->data_src.val); | |
a5cdd40c | 5398 | |
fdfbbd07 AK |
5399 | if (sample_type & PERF_SAMPLE_TRANSACTION) |
5400 | perf_output_put(handle, data->txn); | |
5401 | ||
60e2364e SE |
5402 | if (sample_type & PERF_SAMPLE_REGS_INTR) { |
5403 | u64 abi = data->regs_intr.abi; | |
5404 | /* | |
5405 | * If there are no regs to dump, notice it through | |
5406 | * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). | |
5407 | */ | |
5408 | perf_output_put(handle, abi); | |
5409 | ||
5410 | if (abi) { | |
5411 | u64 mask = event->attr.sample_regs_intr; | |
5412 | ||
5413 | perf_output_sample_regs(handle, | |
5414 | data->regs_intr.regs, | |
5415 | mask); | |
5416 | } | |
5417 | } | |
5418 | ||
a5cdd40c PZ |
5419 | if (!event->attr.watermark) { |
5420 | int wakeup_events = event->attr.wakeup_events; | |
5421 | ||
5422 | if (wakeup_events) { | |
5423 | struct ring_buffer *rb = handle->rb; | |
5424 | int events = local_inc_return(&rb->events); | |
5425 | ||
5426 | if (events >= wakeup_events) { | |
5427 | local_sub(wakeup_events, &rb->events); | |
5428 | local_inc(&rb->wakeup); | |
5429 | } | |
5430 | } | |
5431 | } | |
5622f295 MM |
5432 | } |
5433 | ||
5434 | void perf_prepare_sample(struct perf_event_header *header, | |
5435 | struct perf_sample_data *data, | |
cdd6c482 | 5436 | struct perf_event *event, |
5622f295 | 5437 | struct pt_regs *regs) |
7b732a75 | 5438 | { |
cdd6c482 | 5439 | u64 sample_type = event->attr.sample_type; |
7b732a75 | 5440 | |
cdd6c482 | 5441 | header->type = PERF_RECORD_SAMPLE; |
c320c7b7 | 5442 | header->size = sizeof(*header) + event->header_size; |
5622f295 MM |
5443 | |
5444 | header->misc = 0; | |
5445 | header->misc |= perf_misc_flags(regs); | |
6fab0192 | 5446 | |
c980d109 | 5447 | __perf_event_header__init_id(header, data, event); |
6844c09d | 5448 | |
c320c7b7 | 5449 | if (sample_type & PERF_SAMPLE_IP) |
5622f295 MM |
5450 | data->ip = perf_instruction_pointer(regs); |
5451 | ||
b23f3325 | 5452 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
5622f295 | 5453 | int size = 1; |
394ee076 | 5454 | |
e6dab5ff | 5455 | data->callchain = perf_callchain(event, regs); |
5622f295 MM |
5456 | |
5457 | if (data->callchain) | |
5458 | size += data->callchain->nr; | |
5459 | ||
5460 | header->size += size * sizeof(u64); | |
394ee076 PZ |
5461 | } |
5462 | ||
3a43ce68 | 5463 | if (sample_type & PERF_SAMPLE_RAW) { |
a044560c PZ |
5464 | int size = sizeof(u32); |
5465 | ||
5466 | if (data->raw) | |
5467 | size += data->raw->size; | |
5468 | else | |
5469 | size += sizeof(u32); | |
5470 | ||
fa128e6a | 5471 | header->size += round_up(size, sizeof(u64)); |
7f453c24 | 5472 | } |
bce38cd5 SE |
5473 | |
5474 | if (sample_type & PERF_SAMPLE_BRANCH_STACK) { | |
5475 | int size = sizeof(u64); /* nr */ | |
5476 | if (data->br_stack) { | |
5477 | size += data->br_stack->nr | |
5478 | * sizeof(struct perf_branch_entry); | |
5479 | } | |
5480 | header->size += size; | |
5481 | } | |
4018994f | 5482 | |
2565711f | 5483 | if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) |
88a7c26a AL |
5484 | perf_sample_regs_user(&data->regs_user, regs, |
5485 | &data->regs_user_copy); | |
2565711f | 5486 | |
4018994f JO |
5487 | if (sample_type & PERF_SAMPLE_REGS_USER) { |
5488 | /* regs dump ABI info */ | |
5489 | int size = sizeof(u64); | |
5490 | ||
4018994f JO |
5491 | if (data->regs_user.regs) { |
5492 | u64 mask = event->attr.sample_regs_user; | |
5493 | size += hweight64(mask) * sizeof(u64); | |
5494 | } | |
5495 | ||
5496 | header->size += size; | |
5497 | } | |
c5ebcedb JO |
5498 | |
5499 | if (sample_type & PERF_SAMPLE_STACK_USER) { | |
5500 | /* | |
5501 | * Either we need PERF_SAMPLE_STACK_USER bit to be allways | |
5502 | * processed as the last one or have additional check added | |
5503 | * in case new sample type is added, because we could eat | |
5504 | * up the rest of the sample size. | |
5505 | */ | |
c5ebcedb JO |
5506 | u16 stack_size = event->attr.sample_stack_user; |
5507 | u16 size = sizeof(u64); | |
5508 | ||
c5ebcedb | 5509 | stack_size = perf_sample_ustack_size(stack_size, header->size, |
2565711f | 5510 | data->regs_user.regs); |
c5ebcedb JO |
5511 | |
5512 | /* | |
5513 | * If there is something to dump, add space for the dump | |
5514 | * itself and for the field that tells the dynamic size, | |
5515 | * which is how many have been actually dumped. | |
5516 | */ | |
5517 | if (stack_size) | |
5518 | size += sizeof(u64) + stack_size; | |
5519 | ||
5520 | data->stack_user_size = stack_size; | |
5521 | header->size += size; | |
5522 | } | |
60e2364e SE |
5523 | |
5524 | if (sample_type & PERF_SAMPLE_REGS_INTR) { | |
5525 | /* regs dump ABI info */ | |
5526 | int size = sizeof(u64); | |
5527 | ||
5528 | perf_sample_regs_intr(&data->regs_intr, regs); | |
5529 | ||
5530 | if (data->regs_intr.regs) { | |
5531 | u64 mask = event->attr.sample_regs_intr; | |
5532 | ||
5533 | size += hweight64(mask) * sizeof(u64); | |
5534 | } | |
5535 | ||
5536 | header->size += size; | |
5537 | } | |
5622f295 | 5538 | } |
7f453c24 | 5539 | |
21509084 YZ |
5540 | void perf_event_output(struct perf_event *event, |
5541 | struct perf_sample_data *data, | |
5542 | struct pt_regs *regs) | |
5622f295 MM |
5543 | { |
5544 | struct perf_output_handle handle; | |
5545 | struct perf_event_header header; | |
689802b2 | 5546 | |
927c7a9e FW |
5547 | /* protect the callchain buffers */ |
5548 | rcu_read_lock(); | |
5549 | ||
cdd6c482 | 5550 | perf_prepare_sample(&header, data, event, regs); |
5c148194 | 5551 | |
a7ac67ea | 5552 | if (perf_output_begin(&handle, event, header.size)) |
927c7a9e | 5553 | goto exit; |
0322cd6e | 5554 | |
cdd6c482 | 5555 | perf_output_sample(&handle, &header, data, event); |
f413cdb8 | 5556 | |
8a057d84 | 5557 | perf_output_end(&handle); |
927c7a9e FW |
5558 | |
5559 | exit: | |
5560 | rcu_read_unlock(); | |
0322cd6e PZ |
5561 | } |
5562 | ||
38b200d6 | 5563 | /* |
cdd6c482 | 5564 | * read event_id |
38b200d6 PZ |
5565 | */ |
5566 | ||
5567 | struct perf_read_event { | |
5568 | struct perf_event_header header; | |
5569 | ||
5570 | u32 pid; | |
5571 | u32 tid; | |
38b200d6 PZ |
5572 | }; |
5573 | ||
5574 | static void | |
cdd6c482 | 5575 | perf_event_read_event(struct perf_event *event, |
38b200d6 PZ |
5576 | struct task_struct *task) |
5577 | { | |
5578 | struct perf_output_handle handle; | |
c980d109 | 5579 | struct perf_sample_data sample; |
dfc65094 | 5580 | struct perf_read_event read_event = { |
38b200d6 | 5581 | .header = { |
cdd6c482 | 5582 | .type = PERF_RECORD_READ, |
38b200d6 | 5583 | .misc = 0, |
c320c7b7 | 5584 | .size = sizeof(read_event) + event->read_size, |
38b200d6 | 5585 | }, |
cdd6c482 IM |
5586 | .pid = perf_event_pid(event, task), |
5587 | .tid = perf_event_tid(event, task), | |
38b200d6 | 5588 | }; |
3dab77fb | 5589 | int ret; |
38b200d6 | 5590 | |
c980d109 | 5591 | perf_event_header__init_id(&read_event.header, &sample, event); |
a7ac67ea | 5592 | ret = perf_output_begin(&handle, event, read_event.header.size); |
38b200d6 PZ |
5593 | if (ret) |
5594 | return; | |
5595 | ||
dfc65094 | 5596 | perf_output_put(&handle, read_event); |
cdd6c482 | 5597 | perf_output_read(&handle, event); |
c980d109 | 5598 | perf_event__output_id_sample(event, &handle, &sample); |
3dab77fb | 5599 | |
38b200d6 PZ |
5600 | perf_output_end(&handle); |
5601 | } | |
5602 | ||
52d857a8 JO |
5603 | typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data); |
5604 | ||
5605 | static void | |
5606 | perf_event_aux_ctx(struct perf_event_context *ctx, | |
52d857a8 JO |
5607 | perf_event_aux_output_cb output, |
5608 | void *data) | |
5609 | { | |
5610 | struct perf_event *event; | |
5611 | ||
5612 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
5613 | if (event->state < PERF_EVENT_STATE_INACTIVE) | |
5614 | continue; | |
5615 | if (!event_filter_match(event)) | |
5616 | continue; | |
67516844 | 5617 | output(event, data); |
52d857a8 JO |
5618 | } |
5619 | } | |
5620 | ||
4e93ad60 JO |
5621 | static void |
5622 | perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data, | |
5623 | struct perf_event_context *task_ctx) | |
5624 | { | |
5625 | rcu_read_lock(); | |
5626 | preempt_disable(); | |
5627 | perf_event_aux_ctx(task_ctx, output, data); | |
5628 | preempt_enable(); | |
5629 | rcu_read_unlock(); | |
5630 | } | |
5631 | ||
52d857a8 | 5632 | static void |
67516844 | 5633 | perf_event_aux(perf_event_aux_output_cb output, void *data, |
52d857a8 JO |
5634 | struct perf_event_context *task_ctx) |
5635 | { | |
5636 | struct perf_cpu_context *cpuctx; | |
5637 | struct perf_event_context *ctx; | |
5638 | struct pmu *pmu; | |
5639 | int ctxn; | |
5640 | ||
4e93ad60 JO |
5641 | /* |
5642 | * If we have task_ctx != NULL we only notify | |
5643 | * the task context itself. The task_ctx is set | |
5644 | * only for EXIT events before releasing task | |
5645 | * context. | |
5646 | */ | |
5647 | if (task_ctx) { | |
5648 | perf_event_aux_task_ctx(output, data, task_ctx); | |
5649 | return; | |
5650 | } | |
5651 | ||
52d857a8 JO |
5652 | rcu_read_lock(); |
5653 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
5654 | cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); | |
5655 | if (cpuctx->unique_pmu != pmu) | |
5656 | goto next; | |
67516844 | 5657 | perf_event_aux_ctx(&cpuctx->ctx, output, data); |
52d857a8 JO |
5658 | ctxn = pmu->task_ctx_nr; |
5659 | if (ctxn < 0) | |
5660 | goto next; | |
5661 | ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); | |
5662 | if (ctx) | |
67516844 | 5663 | perf_event_aux_ctx(ctx, output, data); |
52d857a8 JO |
5664 | next: |
5665 | put_cpu_ptr(pmu->pmu_cpu_context); | |
5666 | } | |
52d857a8 JO |
5667 | rcu_read_unlock(); |
5668 | } | |
5669 | ||
60313ebe | 5670 | /* |
9f498cc5 PZ |
5671 | * task tracking -- fork/exit |
5672 | * | |
13d7a241 | 5673 | * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task |
60313ebe PZ |
5674 | */ |
5675 | ||
9f498cc5 | 5676 | struct perf_task_event { |
3a80b4a3 | 5677 | struct task_struct *task; |
cdd6c482 | 5678 | struct perf_event_context *task_ctx; |
60313ebe PZ |
5679 | |
5680 | struct { | |
5681 | struct perf_event_header header; | |
5682 | ||
5683 | u32 pid; | |
5684 | u32 ppid; | |
9f498cc5 PZ |
5685 | u32 tid; |
5686 | u32 ptid; | |
393b2ad8 | 5687 | u64 time; |
cdd6c482 | 5688 | } event_id; |
60313ebe PZ |
5689 | }; |
5690 | ||
67516844 JO |
5691 | static int perf_event_task_match(struct perf_event *event) |
5692 | { | |
13d7a241 SE |
5693 | return event->attr.comm || event->attr.mmap || |
5694 | event->attr.mmap2 || event->attr.mmap_data || | |
5695 | event->attr.task; | |
67516844 JO |
5696 | } |
5697 | ||
cdd6c482 | 5698 | static void perf_event_task_output(struct perf_event *event, |
52d857a8 | 5699 | void *data) |
60313ebe | 5700 | { |
52d857a8 | 5701 | struct perf_task_event *task_event = data; |
60313ebe | 5702 | struct perf_output_handle handle; |
c980d109 | 5703 | struct perf_sample_data sample; |
9f498cc5 | 5704 | struct task_struct *task = task_event->task; |
c980d109 | 5705 | int ret, size = task_event->event_id.header.size; |
8bb39f9a | 5706 | |
67516844 JO |
5707 | if (!perf_event_task_match(event)) |
5708 | return; | |
5709 | ||
c980d109 | 5710 | perf_event_header__init_id(&task_event->event_id.header, &sample, event); |
60313ebe | 5711 | |
c980d109 | 5712 | ret = perf_output_begin(&handle, event, |
a7ac67ea | 5713 | task_event->event_id.header.size); |
ef60777c | 5714 | if (ret) |
c980d109 | 5715 | goto out; |
60313ebe | 5716 | |
cdd6c482 IM |
5717 | task_event->event_id.pid = perf_event_pid(event, task); |
5718 | task_event->event_id.ppid = perf_event_pid(event, current); | |
60313ebe | 5719 | |
cdd6c482 IM |
5720 | task_event->event_id.tid = perf_event_tid(event, task); |
5721 | task_event->event_id.ptid = perf_event_tid(event, current); | |
9f498cc5 | 5722 | |
34f43927 PZ |
5723 | task_event->event_id.time = perf_event_clock(event); |
5724 | ||
cdd6c482 | 5725 | perf_output_put(&handle, task_event->event_id); |
393b2ad8 | 5726 | |
c980d109 ACM |
5727 | perf_event__output_id_sample(event, &handle, &sample); |
5728 | ||
60313ebe | 5729 | perf_output_end(&handle); |
c980d109 ACM |
5730 | out: |
5731 | task_event->event_id.header.size = size; | |
60313ebe PZ |
5732 | } |
5733 | ||
cdd6c482 IM |
5734 | static void perf_event_task(struct task_struct *task, |
5735 | struct perf_event_context *task_ctx, | |
3a80b4a3 | 5736 | int new) |
60313ebe | 5737 | { |
9f498cc5 | 5738 | struct perf_task_event task_event; |
60313ebe | 5739 | |
cdd6c482 IM |
5740 | if (!atomic_read(&nr_comm_events) && |
5741 | !atomic_read(&nr_mmap_events) && | |
5742 | !atomic_read(&nr_task_events)) | |
60313ebe PZ |
5743 | return; |
5744 | ||
9f498cc5 | 5745 | task_event = (struct perf_task_event){ |
3a80b4a3 PZ |
5746 | .task = task, |
5747 | .task_ctx = task_ctx, | |
cdd6c482 | 5748 | .event_id = { |
60313ebe | 5749 | .header = { |
cdd6c482 | 5750 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
573402db | 5751 | .misc = 0, |
cdd6c482 | 5752 | .size = sizeof(task_event.event_id), |
60313ebe | 5753 | }, |
573402db PZ |
5754 | /* .pid */ |
5755 | /* .ppid */ | |
9f498cc5 PZ |
5756 | /* .tid */ |
5757 | /* .ptid */ | |
34f43927 | 5758 | /* .time */ |
60313ebe PZ |
5759 | }, |
5760 | }; | |
5761 | ||
67516844 | 5762 | perf_event_aux(perf_event_task_output, |
52d857a8 JO |
5763 | &task_event, |
5764 | task_ctx); | |
9f498cc5 PZ |
5765 | } |
5766 | ||
cdd6c482 | 5767 | void perf_event_fork(struct task_struct *task) |
9f498cc5 | 5768 | { |
cdd6c482 | 5769 | perf_event_task(task, NULL, 1); |
60313ebe PZ |
5770 | } |
5771 | ||
8d1b2d93 PZ |
5772 | /* |
5773 | * comm tracking | |
5774 | */ | |
5775 | ||
5776 | struct perf_comm_event { | |
22a4f650 IM |
5777 | struct task_struct *task; |
5778 | char *comm; | |
8d1b2d93 PZ |
5779 | int comm_size; |
5780 | ||
5781 | struct { | |
5782 | struct perf_event_header header; | |
5783 | ||
5784 | u32 pid; | |
5785 | u32 tid; | |
cdd6c482 | 5786 | } event_id; |
8d1b2d93 PZ |
5787 | }; |
5788 | ||
67516844 JO |
5789 | static int perf_event_comm_match(struct perf_event *event) |
5790 | { | |
5791 | return event->attr.comm; | |
5792 | } | |
5793 | ||
cdd6c482 | 5794 | static void perf_event_comm_output(struct perf_event *event, |
52d857a8 | 5795 | void *data) |
8d1b2d93 | 5796 | { |
52d857a8 | 5797 | struct perf_comm_event *comm_event = data; |
8d1b2d93 | 5798 | struct perf_output_handle handle; |
c980d109 | 5799 | struct perf_sample_data sample; |
cdd6c482 | 5800 | int size = comm_event->event_id.header.size; |
c980d109 ACM |
5801 | int ret; |
5802 | ||
67516844 JO |
5803 | if (!perf_event_comm_match(event)) |
5804 | return; | |
5805 | ||
c980d109 ACM |
5806 | perf_event_header__init_id(&comm_event->event_id.header, &sample, event); |
5807 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5808 | comm_event->event_id.header.size); |
8d1b2d93 PZ |
5809 | |
5810 | if (ret) | |
c980d109 | 5811 | goto out; |
8d1b2d93 | 5812 | |
cdd6c482 IM |
5813 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
5814 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); | |
709e50cf | 5815 | |
cdd6c482 | 5816 | perf_output_put(&handle, comm_event->event_id); |
76369139 | 5817 | __output_copy(&handle, comm_event->comm, |
8d1b2d93 | 5818 | comm_event->comm_size); |
c980d109 ACM |
5819 | |
5820 | perf_event__output_id_sample(event, &handle, &sample); | |
5821 | ||
8d1b2d93 | 5822 | perf_output_end(&handle); |
c980d109 ACM |
5823 | out: |
5824 | comm_event->event_id.header.size = size; | |
8d1b2d93 PZ |
5825 | } |
5826 | ||
cdd6c482 | 5827 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
8d1b2d93 | 5828 | { |
413ee3b4 | 5829 | char comm[TASK_COMM_LEN]; |
8d1b2d93 | 5830 | unsigned int size; |
8d1b2d93 | 5831 | |
413ee3b4 | 5832 | memset(comm, 0, sizeof(comm)); |
96b02d78 | 5833 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
888fcee0 | 5834 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
8d1b2d93 PZ |
5835 | |
5836 | comm_event->comm = comm; | |
5837 | comm_event->comm_size = size; | |
5838 | ||
cdd6c482 | 5839 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
8dc85d54 | 5840 | |
67516844 | 5841 | perf_event_aux(perf_event_comm_output, |
52d857a8 JO |
5842 | comm_event, |
5843 | NULL); | |
8d1b2d93 PZ |
5844 | } |
5845 | ||
82b89778 | 5846 | void perf_event_comm(struct task_struct *task, bool exec) |
8d1b2d93 | 5847 | { |
9ee318a7 PZ |
5848 | struct perf_comm_event comm_event; |
5849 | ||
cdd6c482 | 5850 | if (!atomic_read(&nr_comm_events)) |
9ee318a7 | 5851 | return; |
a63eaf34 | 5852 | |
9ee318a7 | 5853 | comm_event = (struct perf_comm_event){ |
8d1b2d93 | 5854 | .task = task, |
573402db PZ |
5855 | /* .comm */ |
5856 | /* .comm_size */ | |
cdd6c482 | 5857 | .event_id = { |
573402db | 5858 | .header = { |
cdd6c482 | 5859 | .type = PERF_RECORD_COMM, |
82b89778 | 5860 | .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, |
573402db PZ |
5861 | /* .size */ |
5862 | }, | |
5863 | /* .pid */ | |
5864 | /* .tid */ | |
8d1b2d93 PZ |
5865 | }, |
5866 | }; | |
5867 | ||
cdd6c482 | 5868 | perf_event_comm_event(&comm_event); |
8d1b2d93 PZ |
5869 | } |
5870 | ||
0a4a9391 PZ |
5871 | /* |
5872 | * mmap tracking | |
5873 | */ | |
5874 | ||
5875 | struct perf_mmap_event { | |
089dd79d PZ |
5876 | struct vm_area_struct *vma; |
5877 | ||
5878 | const char *file_name; | |
5879 | int file_size; | |
13d7a241 SE |
5880 | int maj, min; |
5881 | u64 ino; | |
5882 | u64 ino_generation; | |
f972eb63 | 5883 | u32 prot, flags; |
0a4a9391 PZ |
5884 | |
5885 | struct { | |
5886 | struct perf_event_header header; | |
5887 | ||
5888 | u32 pid; | |
5889 | u32 tid; | |
5890 | u64 start; | |
5891 | u64 len; | |
5892 | u64 pgoff; | |
cdd6c482 | 5893 | } event_id; |
0a4a9391 PZ |
5894 | }; |
5895 | ||
67516844 JO |
5896 | static int perf_event_mmap_match(struct perf_event *event, |
5897 | void *data) | |
5898 | { | |
5899 | struct perf_mmap_event *mmap_event = data; | |
5900 | struct vm_area_struct *vma = mmap_event->vma; | |
5901 | int executable = vma->vm_flags & VM_EXEC; | |
5902 | ||
5903 | return (!executable && event->attr.mmap_data) || | |
13d7a241 | 5904 | (executable && (event->attr.mmap || event->attr.mmap2)); |
67516844 JO |
5905 | } |
5906 | ||
cdd6c482 | 5907 | static void perf_event_mmap_output(struct perf_event *event, |
52d857a8 | 5908 | void *data) |
0a4a9391 | 5909 | { |
52d857a8 | 5910 | struct perf_mmap_event *mmap_event = data; |
0a4a9391 | 5911 | struct perf_output_handle handle; |
c980d109 | 5912 | struct perf_sample_data sample; |
cdd6c482 | 5913 | int size = mmap_event->event_id.header.size; |
c980d109 | 5914 | int ret; |
0a4a9391 | 5915 | |
67516844 JO |
5916 | if (!perf_event_mmap_match(event, data)) |
5917 | return; | |
5918 | ||
13d7a241 SE |
5919 | if (event->attr.mmap2) { |
5920 | mmap_event->event_id.header.type = PERF_RECORD_MMAP2; | |
5921 | mmap_event->event_id.header.size += sizeof(mmap_event->maj); | |
5922 | mmap_event->event_id.header.size += sizeof(mmap_event->min); | |
5923 | mmap_event->event_id.header.size += sizeof(mmap_event->ino); | |
d008d525 | 5924 | mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); |
f972eb63 PZ |
5925 | mmap_event->event_id.header.size += sizeof(mmap_event->prot); |
5926 | mmap_event->event_id.header.size += sizeof(mmap_event->flags); | |
13d7a241 SE |
5927 | } |
5928 | ||
c980d109 ACM |
5929 | perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); |
5930 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 5931 | mmap_event->event_id.header.size); |
0a4a9391 | 5932 | if (ret) |
c980d109 | 5933 | goto out; |
0a4a9391 | 5934 | |
cdd6c482 IM |
5935 | mmap_event->event_id.pid = perf_event_pid(event, current); |
5936 | mmap_event->event_id.tid = perf_event_tid(event, current); | |
709e50cf | 5937 | |
cdd6c482 | 5938 | perf_output_put(&handle, mmap_event->event_id); |
13d7a241 SE |
5939 | |
5940 | if (event->attr.mmap2) { | |
5941 | perf_output_put(&handle, mmap_event->maj); | |
5942 | perf_output_put(&handle, mmap_event->min); | |
5943 | perf_output_put(&handle, mmap_event->ino); | |
5944 | perf_output_put(&handle, mmap_event->ino_generation); | |
f972eb63 PZ |
5945 | perf_output_put(&handle, mmap_event->prot); |
5946 | perf_output_put(&handle, mmap_event->flags); | |
13d7a241 SE |
5947 | } |
5948 | ||
76369139 | 5949 | __output_copy(&handle, mmap_event->file_name, |
0a4a9391 | 5950 | mmap_event->file_size); |
c980d109 ACM |
5951 | |
5952 | perf_event__output_id_sample(event, &handle, &sample); | |
5953 | ||
78d613eb | 5954 | perf_output_end(&handle); |
c980d109 ACM |
5955 | out: |
5956 | mmap_event->event_id.header.size = size; | |
0a4a9391 PZ |
5957 | } |
5958 | ||
cdd6c482 | 5959 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
0a4a9391 | 5960 | { |
089dd79d PZ |
5961 | struct vm_area_struct *vma = mmap_event->vma; |
5962 | struct file *file = vma->vm_file; | |
13d7a241 SE |
5963 | int maj = 0, min = 0; |
5964 | u64 ino = 0, gen = 0; | |
f972eb63 | 5965 | u32 prot = 0, flags = 0; |
0a4a9391 PZ |
5966 | unsigned int size; |
5967 | char tmp[16]; | |
5968 | char *buf = NULL; | |
2c42cfbf | 5969 | char *name; |
413ee3b4 | 5970 | |
0a4a9391 | 5971 | if (file) { |
13d7a241 SE |
5972 | struct inode *inode; |
5973 | dev_t dev; | |
3ea2f2b9 | 5974 | |
2c42cfbf | 5975 | buf = kmalloc(PATH_MAX, GFP_KERNEL); |
0a4a9391 | 5976 | if (!buf) { |
c7e548b4 ON |
5977 | name = "//enomem"; |
5978 | goto cpy_name; | |
0a4a9391 | 5979 | } |
413ee3b4 | 5980 | /* |
3ea2f2b9 | 5981 | * d_path() works from the end of the rb backwards, so we |
413ee3b4 AB |
5982 | * need to add enough zero bytes after the string to handle |
5983 | * the 64bit alignment we do later. | |
5984 | */ | |
9bf39ab2 | 5985 | name = file_path(file, buf, PATH_MAX - sizeof(u64)); |
0a4a9391 | 5986 | if (IS_ERR(name)) { |
c7e548b4 ON |
5987 | name = "//toolong"; |
5988 | goto cpy_name; | |
0a4a9391 | 5989 | } |
13d7a241 SE |
5990 | inode = file_inode(vma->vm_file); |
5991 | dev = inode->i_sb->s_dev; | |
5992 | ino = inode->i_ino; | |
5993 | gen = inode->i_generation; | |
5994 | maj = MAJOR(dev); | |
5995 | min = MINOR(dev); | |
f972eb63 PZ |
5996 | |
5997 | if (vma->vm_flags & VM_READ) | |
5998 | prot |= PROT_READ; | |
5999 | if (vma->vm_flags & VM_WRITE) | |
6000 | prot |= PROT_WRITE; | |
6001 | if (vma->vm_flags & VM_EXEC) | |
6002 | prot |= PROT_EXEC; | |
6003 | ||
6004 | if (vma->vm_flags & VM_MAYSHARE) | |
6005 | flags = MAP_SHARED; | |
6006 | else | |
6007 | flags = MAP_PRIVATE; | |
6008 | ||
6009 | if (vma->vm_flags & VM_DENYWRITE) | |
6010 | flags |= MAP_DENYWRITE; | |
6011 | if (vma->vm_flags & VM_MAYEXEC) | |
6012 | flags |= MAP_EXECUTABLE; | |
6013 | if (vma->vm_flags & VM_LOCKED) | |
6014 | flags |= MAP_LOCKED; | |
6015 | if (vma->vm_flags & VM_HUGETLB) | |
6016 | flags |= MAP_HUGETLB; | |
6017 | ||
c7e548b4 | 6018 | goto got_name; |
0a4a9391 | 6019 | } else { |
fbe26abe JO |
6020 | if (vma->vm_ops && vma->vm_ops->name) { |
6021 | name = (char *) vma->vm_ops->name(vma); | |
6022 | if (name) | |
6023 | goto cpy_name; | |
6024 | } | |
6025 | ||
2c42cfbf | 6026 | name = (char *)arch_vma_name(vma); |
c7e548b4 ON |
6027 | if (name) |
6028 | goto cpy_name; | |
089dd79d | 6029 | |
32c5fb7e | 6030 | if (vma->vm_start <= vma->vm_mm->start_brk && |
3af9e859 | 6031 | vma->vm_end >= vma->vm_mm->brk) { |
c7e548b4 ON |
6032 | name = "[heap]"; |
6033 | goto cpy_name; | |
32c5fb7e ON |
6034 | } |
6035 | if (vma->vm_start <= vma->vm_mm->start_stack && | |
3af9e859 | 6036 | vma->vm_end >= vma->vm_mm->start_stack) { |
c7e548b4 ON |
6037 | name = "[stack]"; |
6038 | goto cpy_name; | |
089dd79d PZ |
6039 | } |
6040 | ||
c7e548b4 ON |
6041 | name = "//anon"; |
6042 | goto cpy_name; | |
0a4a9391 PZ |
6043 | } |
6044 | ||
c7e548b4 ON |
6045 | cpy_name: |
6046 | strlcpy(tmp, name, sizeof(tmp)); | |
6047 | name = tmp; | |
0a4a9391 | 6048 | got_name: |
2c42cfbf PZ |
6049 | /* |
6050 | * Since our buffer works in 8 byte units we need to align our string | |
6051 | * size to a multiple of 8. However, we must guarantee the tail end is | |
6052 | * zero'd out to avoid leaking random bits to userspace. | |
6053 | */ | |
6054 | size = strlen(name)+1; | |
6055 | while (!IS_ALIGNED(size, sizeof(u64))) | |
6056 | name[size++] = '\0'; | |
0a4a9391 PZ |
6057 | |
6058 | mmap_event->file_name = name; | |
6059 | mmap_event->file_size = size; | |
13d7a241 SE |
6060 | mmap_event->maj = maj; |
6061 | mmap_event->min = min; | |
6062 | mmap_event->ino = ino; | |
6063 | mmap_event->ino_generation = gen; | |
f972eb63 PZ |
6064 | mmap_event->prot = prot; |
6065 | mmap_event->flags = flags; | |
0a4a9391 | 6066 | |
2fe85427 SE |
6067 | if (!(vma->vm_flags & VM_EXEC)) |
6068 | mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; | |
6069 | ||
cdd6c482 | 6070 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
0a4a9391 | 6071 | |
67516844 | 6072 | perf_event_aux(perf_event_mmap_output, |
52d857a8 JO |
6073 | mmap_event, |
6074 | NULL); | |
665c2142 | 6075 | |
0a4a9391 PZ |
6076 | kfree(buf); |
6077 | } | |
6078 | ||
3af9e859 | 6079 | void perf_event_mmap(struct vm_area_struct *vma) |
0a4a9391 | 6080 | { |
9ee318a7 PZ |
6081 | struct perf_mmap_event mmap_event; |
6082 | ||
cdd6c482 | 6083 | if (!atomic_read(&nr_mmap_events)) |
9ee318a7 PZ |
6084 | return; |
6085 | ||
6086 | mmap_event = (struct perf_mmap_event){ | |
089dd79d | 6087 | .vma = vma, |
573402db PZ |
6088 | /* .file_name */ |
6089 | /* .file_size */ | |
cdd6c482 | 6090 | .event_id = { |
573402db | 6091 | .header = { |
cdd6c482 | 6092 | .type = PERF_RECORD_MMAP, |
39447b38 | 6093 | .misc = PERF_RECORD_MISC_USER, |
573402db PZ |
6094 | /* .size */ |
6095 | }, | |
6096 | /* .pid */ | |
6097 | /* .tid */ | |
089dd79d PZ |
6098 | .start = vma->vm_start, |
6099 | .len = vma->vm_end - vma->vm_start, | |
3a0304e9 | 6100 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
0a4a9391 | 6101 | }, |
13d7a241 SE |
6102 | /* .maj (attr_mmap2 only) */ |
6103 | /* .min (attr_mmap2 only) */ | |
6104 | /* .ino (attr_mmap2 only) */ | |
6105 | /* .ino_generation (attr_mmap2 only) */ | |
f972eb63 PZ |
6106 | /* .prot (attr_mmap2 only) */ |
6107 | /* .flags (attr_mmap2 only) */ | |
0a4a9391 PZ |
6108 | }; |
6109 | ||
cdd6c482 | 6110 | perf_event_mmap_event(&mmap_event); |
0a4a9391 PZ |
6111 | } |
6112 | ||
68db7e98 AS |
6113 | void perf_event_aux_event(struct perf_event *event, unsigned long head, |
6114 | unsigned long size, u64 flags) | |
6115 | { | |
6116 | struct perf_output_handle handle; | |
6117 | struct perf_sample_data sample; | |
6118 | struct perf_aux_event { | |
6119 | struct perf_event_header header; | |
6120 | u64 offset; | |
6121 | u64 size; | |
6122 | u64 flags; | |
6123 | } rec = { | |
6124 | .header = { | |
6125 | .type = PERF_RECORD_AUX, | |
6126 | .misc = 0, | |
6127 | .size = sizeof(rec), | |
6128 | }, | |
6129 | .offset = head, | |
6130 | .size = size, | |
6131 | .flags = flags, | |
6132 | }; | |
6133 | int ret; | |
6134 | ||
6135 | perf_event_header__init_id(&rec.header, &sample, event); | |
6136 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6137 | ||
6138 | if (ret) | |
6139 | return; | |
6140 | ||
6141 | perf_output_put(&handle, rec); | |
6142 | perf_event__output_id_sample(event, &handle, &sample); | |
6143 | ||
6144 | perf_output_end(&handle); | |
6145 | } | |
6146 | ||
f38b0dbb KL |
6147 | /* |
6148 | * Lost/dropped samples logging | |
6149 | */ | |
6150 | void perf_log_lost_samples(struct perf_event *event, u64 lost) | |
6151 | { | |
6152 | struct perf_output_handle handle; | |
6153 | struct perf_sample_data sample; | |
6154 | int ret; | |
6155 | ||
6156 | struct { | |
6157 | struct perf_event_header header; | |
6158 | u64 lost; | |
6159 | } lost_samples_event = { | |
6160 | .header = { | |
6161 | .type = PERF_RECORD_LOST_SAMPLES, | |
6162 | .misc = 0, | |
6163 | .size = sizeof(lost_samples_event), | |
6164 | }, | |
6165 | .lost = lost, | |
6166 | }; | |
6167 | ||
6168 | perf_event_header__init_id(&lost_samples_event.header, &sample, event); | |
6169 | ||
6170 | ret = perf_output_begin(&handle, event, | |
6171 | lost_samples_event.header.size); | |
6172 | if (ret) | |
6173 | return; | |
6174 | ||
6175 | perf_output_put(&handle, lost_samples_event); | |
6176 | perf_event__output_id_sample(event, &handle, &sample); | |
6177 | perf_output_end(&handle); | |
6178 | } | |
6179 | ||
45ac1403 AH |
6180 | /* |
6181 | * context_switch tracking | |
6182 | */ | |
6183 | ||
6184 | struct perf_switch_event { | |
6185 | struct task_struct *task; | |
6186 | struct task_struct *next_prev; | |
6187 | ||
6188 | struct { | |
6189 | struct perf_event_header header; | |
6190 | u32 next_prev_pid; | |
6191 | u32 next_prev_tid; | |
6192 | } event_id; | |
6193 | }; | |
6194 | ||
6195 | static int perf_event_switch_match(struct perf_event *event) | |
6196 | { | |
6197 | return event->attr.context_switch; | |
6198 | } | |
6199 | ||
6200 | static void perf_event_switch_output(struct perf_event *event, void *data) | |
6201 | { | |
6202 | struct perf_switch_event *se = data; | |
6203 | struct perf_output_handle handle; | |
6204 | struct perf_sample_data sample; | |
6205 | int ret; | |
6206 | ||
6207 | if (!perf_event_switch_match(event)) | |
6208 | return; | |
6209 | ||
6210 | /* Only CPU-wide events are allowed to see next/prev pid/tid */ | |
6211 | if (event->ctx->task) { | |
6212 | se->event_id.header.type = PERF_RECORD_SWITCH; | |
6213 | se->event_id.header.size = sizeof(se->event_id.header); | |
6214 | } else { | |
6215 | se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; | |
6216 | se->event_id.header.size = sizeof(se->event_id); | |
6217 | se->event_id.next_prev_pid = | |
6218 | perf_event_pid(event, se->next_prev); | |
6219 | se->event_id.next_prev_tid = | |
6220 | perf_event_tid(event, se->next_prev); | |
6221 | } | |
6222 | ||
6223 | perf_event_header__init_id(&se->event_id.header, &sample, event); | |
6224 | ||
6225 | ret = perf_output_begin(&handle, event, se->event_id.header.size); | |
6226 | if (ret) | |
6227 | return; | |
6228 | ||
6229 | if (event->ctx->task) | |
6230 | perf_output_put(&handle, se->event_id.header); | |
6231 | else | |
6232 | perf_output_put(&handle, se->event_id); | |
6233 | ||
6234 | perf_event__output_id_sample(event, &handle, &sample); | |
6235 | ||
6236 | perf_output_end(&handle); | |
6237 | } | |
6238 | ||
6239 | static void perf_event_switch(struct task_struct *task, | |
6240 | struct task_struct *next_prev, bool sched_in) | |
6241 | { | |
6242 | struct perf_switch_event switch_event; | |
6243 | ||
6244 | /* N.B. caller checks nr_switch_events != 0 */ | |
6245 | ||
6246 | switch_event = (struct perf_switch_event){ | |
6247 | .task = task, | |
6248 | .next_prev = next_prev, | |
6249 | .event_id = { | |
6250 | .header = { | |
6251 | /* .type */ | |
6252 | .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, | |
6253 | /* .size */ | |
6254 | }, | |
6255 | /* .next_prev_pid */ | |
6256 | /* .next_prev_tid */ | |
6257 | }, | |
6258 | }; | |
6259 | ||
6260 | perf_event_aux(perf_event_switch_output, | |
6261 | &switch_event, | |
6262 | NULL); | |
6263 | } | |
6264 | ||
a78ac325 PZ |
6265 | /* |
6266 | * IRQ throttle logging | |
6267 | */ | |
6268 | ||
cdd6c482 | 6269 | static void perf_log_throttle(struct perf_event *event, int enable) |
a78ac325 PZ |
6270 | { |
6271 | struct perf_output_handle handle; | |
c980d109 | 6272 | struct perf_sample_data sample; |
a78ac325 PZ |
6273 | int ret; |
6274 | ||
6275 | struct { | |
6276 | struct perf_event_header header; | |
6277 | u64 time; | |
cca3f454 | 6278 | u64 id; |
7f453c24 | 6279 | u64 stream_id; |
a78ac325 PZ |
6280 | } throttle_event = { |
6281 | .header = { | |
cdd6c482 | 6282 | .type = PERF_RECORD_THROTTLE, |
a78ac325 PZ |
6283 | .misc = 0, |
6284 | .size = sizeof(throttle_event), | |
6285 | }, | |
34f43927 | 6286 | .time = perf_event_clock(event), |
cdd6c482 IM |
6287 | .id = primary_event_id(event), |
6288 | .stream_id = event->id, | |
a78ac325 PZ |
6289 | }; |
6290 | ||
966ee4d6 | 6291 | if (enable) |
cdd6c482 | 6292 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
966ee4d6 | 6293 | |
c980d109 ACM |
6294 | perf_event_header__init_id(&throttle_event.header, &sample, event); |
6295 | ||
6296 | ret = perf_output_begin(&handle, event, | |
a7ac67ea | 6297 | throttle_event.header.size); |
a78ac325 PZ |
6298 | if (ret) |
6299 | return; | |
6300 | ||
6301 | perf_output_put(&handle, throttle_event); | |
c980d109 | 6302 | perf_event__output_id_sample(event, &handle, &sample); |
a78ac325 PZ |
6303 | perf_output_end(&handle); |
6304 | } | |
6305 | ||
ec0d7729 AS |
6306 | static void perf_log_itrace_start(struct perf_event *event) |
6307 | { | |
6308 | struct perf_output_handle handle; | |
6309 | struct perf_sample_data sample; | |
6310 | struct perf_aux_event { | |
6311 | struct perf_event_header header; | |
6312 | u32 pid; | |
6313 | u32 tid; | |
6314 | } rec; | |
6315 | int ret; | |
6316 | ||
6317 | if (event->parent) | |
6318 | event = event->parent; | |
6319 | ||
6320 | if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || | |
6321 | event->hw.itrace_started) | |
6322 | return; | |
6323 | ||
ec0d7729 AS |
6324 | rec.header.type = PERF_RECORD_ITRACE_START; |
6325 | rec.header.misc = 0; | |
6326 | rec.header.size = sizeof(rec); | |
6327 | rec.pid = perf_event_pid(event, current); | |
6328 | rec.tid = perf_event_tid(event, current); | |
6329 | ||
6330 | perf_event_header__init_id(&rec.header, &sample, event); | |
6331 | ret = perf_output_begin(&handle, event, rec.header.size); | |
6332 | ||
6333 | if (ret) | |
6334 | return; | |
6335 | ||
6336 | perf_output_put(&handle, rec); | |
6337 | perf_event__output_id_sample(event, &handle, &sample); | |
6338 | ||
6339 | perf_output_end(&handle); | |
6340 | } | |
6341 | ||
f6c7d5fe | 6342 | /* |
cdd6c482 | 6343 | * Generic event overflow handling, sampling. |
f6c7d5fe PZ |
6344 | */ |
6345 | ||
a8b0ca17 | 6346 | static int __perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6347 | int throttle, struct perf_sample_data *data, |
6348 | struct pt_regs *regs) | |
f6c7d5fe | 6349 | { |
cdd6c482 IM |
6350 | int events = atomic_read(&event->event_limit); |
6351 | struct hw_perf_event *hwc = &event->hw; | |
e050e3f0 | 6352 | u64 seq; |
79f14641 PZ |
6353 | int ret = 0; |
6354 | ||
96398826 PZ |
6355 | /* |
6356 | * Non-sampling counters might still use the PMI to fold short | |
6357 | * hardware counters, ignore those. | |
6358 | */ | |
6359 | if (unlikely(!is_sampling_event(event))) | |
6360 | return 0; | |
6361 | ||
e050e3f0 SE |
6362 | seq = __this_cpu_read(perf_throttled_seq); |
6363 | if (seq != hwc->interrupts_seq) { | |
6364 | hwc->interrupts_seq = seq; | |
6365 | hwc->interrupts = 1; | |
6366 | } else { | |
6367 | hwc->interrupts++; | |
6368 | if (unlikely(throttle | |
6369 | && hwc->interrupts >= max_samples_per_tick)) { | |
6370 | __this_cpu_inc(perf_throttled_count); | |
163ec435 PZ |
6371 | hwc->interrupts = MAX_INTERRUPTS; |
6372 | perf_log_throttle(event, 0); | |
d84153d6 | 6373 | tick_nohz_full_kick(); |
a78ac325 PZ |
6374 | ret = 1; |
6375 | } | |
e050e3f0 | 6376 | } |
60db5e09 | 6377 | |
cdd6c482 | 6378 | if (event->attr.freq) { |
def0a9b2 | 6379 | u64 now = perf_clock(); |
abd50713 | 6380 | s64 delta = now - hwc->freq_time_stamp; |
bd2b5b12 | 6381 | |
abd50713 | 6382 | hwc->freq_time_stamp = now; |
bd2b5b12 | 6383 | |
abd50713 | 6384 | if (delta > 0 && delta < 2*TICK_NSEC) |
f39d47ff | 6385 | perf_adjust_period(event, delta, hwc->last_period, true); |
bd2b5b12 PZ |
6386 | } |
6387 | ||
2023b359 PZ |
6388 | /* |
6389 | * XXX event_limit might not quite work as expected on inherited | |
cdd6c482 | 6390 | * events |
2023b359 PZ |
6391 | */ |
6392 | ||
cdd6c482 IM |
6393 | event->pending_kill = POLL_IN; |
6394 | if (events && atomic_dec_and_test(&event->event_limit)) { | |
79f14641 | 6395 | ret = 1; |
cdd6c482 | 6396 | event->pending_kill = POLL_HUP; |
a8b0ca17 PZ |
6397 | event->pending_disable = 1; |
6398 | irq_work_queue(&event->pending); | |
79f14641 PZ |
6399 | } |
6400 | ||
453f19ee | 6401 | if (event->overflow_handler) |
a8b0ca17 | 6402 | event->overflow_handler(event, data, regs); |
453f19ee | 6403 | else |
a8b0ca17 | 6404 | perf_event_output(event, data, regs); |
453f19ee | 6405 | |
fed66e2c | 6406 | if (*perf_event_fasync(event) && event->pending_kill) { |
a8b0ca17 PZ |
6407 | event->pending_wakeup = 1; |
6408 | irq_work_queue(&event->pending); | |
f506b3dc PZ |
6409 | } |
6410 | ||
79f14641 | 6411 | return ret; |
f6c7d5fe PZ |
6412 | } |
6413 | ||
a8b0ca17 | 6414 | int perf_event_overflow(struct perf_event *event, |
5622f295 MM |
6415 | struct perf_sample_data *data, |
6416 | struct pt_regs *regs) | |
850bc73f | 6417 | { |
a8b0ca17 | 6418 | return __perf_event_overflow(event, 1, data, regs); |
850bc73f PZ |
6419 | } |
6420 | ||
15dbf27c | 6421 | /* |
cdd6c482 | 6422 | * Generic software event infrastructure |
15dbf27c PZ |
6423 | */ |
6424 | ||
b28ab83c PZ |
6425 | struct swevent_htable { |
6426 | struct swevent_hlist *swevent_hlist; | |
6427 | struct mutex hlist_mutex; | |
6428 | int hlist_refcount; | |
6429 | ||
6430 | /* Recursion avoidance in each contexts */ | |
6431 | int recursion[PERF_NR_CONTEXTS]; | |
6432 | }; | |
6433 | ||
6434 | static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); | |
6435 | ||
7b4b6658 | 6436 | /* |
cdd6c482 IM |
6437 | * We directly increment event->count and keep a second value in |
6438 | * event->hw.period_left to count intervals. This period event | |
7b4b6658 PZ |
6439 | * is kept in the range [-sample_period, 0] so that we can use the |
6440 | * sign as trigger. | |
6441 | */ | |
6442 | ||
ab573844 | 6443 | u64 perf_swevent_set_period(struct perf_event *event) |
15dbf27c | 6444 | { |
cdd6c482 | 6445 | struct hw_perf_event *hwc = &event->hw; |
7b4b6658 PZ |
6446 | u64 period = hwc->last_period; |
6447 | u64 nr, offset; | |
6448 | s64 old, val; | |
6449 | ||
6450 | hwc->last_period = hwc->sample_period; | |
15dbf27c PZ |
6451 | |
6452 | again: | |
e7850595 | 6453 | old = val = local64_read(&hwc->period_left); |
7b4b6658 PZ |
6454 | if (val < 0) |
6455 | return 0; | |
15dbf27c | 6456 | |
7b4b6658 PZ |
6457 | nr = div64_u64(period + val, period); |
6458 | offset = nr * period; | |
6459 | val -= offset; | |
e7850595 | 6460 | if (local64_cmpxchg(&hwc->period_left, old, val) != old) |
7b4b6658 | 6461 | goto again; |
15dbf27c | 6462 | |
7b4b6658 | 6463 | return nr; |
15dbf27c PZ |
6464 | } |
6465 | ||
0cff784a | 6466 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
a8b0ca17 | 6467 | struct perf_sample_data *data, |
5622f295 | 6468 | struct pt_regs *regs) |
15dbf27c | 6469 | { |
cdd6c482 | 6470 | struct hw_perf_event *hwc = &event->hw; |
850bc73f | 6471 | int throttle = 0; |
15dbf27c | 6472 | |
0cff784a PZ |
6473 | if (!overflow) |
6474 | overflow = perf_swevent_set_period(event); | |
15dbf27c | 6475 | |
7b4b6658 PZ |
6476 | if (hwc->interrupts == MAX_INTERRUPTS) |
6477 | return; | |
15dbf27c | 6478 | |
7b4b6658 | 6479 | for (; overflow; overflow--) { |
a8b0ca17 | 6480 | if (__perf_event_overflow(event, throttle, |
5622f295 | 6481 | data, regs)) { |
7b4b6658 PZ |
6482 | /* |
6483 | * We inhibit the overflow from happening when | |
6484 | * hwc->interrupts == MAX_INTERRUPTS. | |
6485 | */ | |
6486 | break; | |
6487 | } | |
cf450a73 | 6488 | throttle = 1; |
7b4b6658 | 6489 | } |
15dbf27c PZ |
6490 | } |
6491 | ||
a4eaf7f1 | 6492 | static void perf_swevent_event(struct perf_event *event, u64 nr, |
a8b0ca17 | 6493 | struct perf_sample_data *data, |
5622f295 | 6494 | struct pt_regs *regs) |
7b4b6658 | 6495 | { |
cdd6c482 | 6496 | struct hw_perf_event *hwc = &event->hw; |
d6d020e9 | 6497 | |
e7850595 | 6498 | local64_add(nr, &event->count); |
d6d020e9 | 6499 | |
0cff784a PZ |
6500 | if (!regs) |
6501 | return; | |
6502 | ||
6c7e550f | 6503 | if (!is_sampling_event(event)) |
7b4b6658 | 6504 | return; |
d6d020e9 | 6505 | |
5d81e5cf AV |
6506 | if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { |
6507 | data->period = nr; | |
6508 | return perf_swevent_overflow(event, 1, data, regs); | |
6509 | } else | |
6510 | data->period = event->hw.last_period; | |
6511 | ||
0cff784a | 6512 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
a8b0ca17 | 6513 | return perf_swevent_overflow(event, 1, data, regs); |
0cff784a | 6514 | |
e7850595 | 6515 | if (local64_add_negative(nr, &hwc->period_left)) |
7b4b6658 | 6516 | return; |
df1a132b | 6517 | |
a8b0ca17 | 6518 | perf_swevent_overflow(event, 0, data, regs); |
d6d020e9 PZ |
6519 | } |
6520 | ||
f5ffe02e FW |
6521 | static int perf_exclude_event(struct perf_event *event, |
6522 | struct pt_regs *regs) | |
6523 | { | |
a4eaf7f1 | 6524 | if (event->hw.state & PERF_HES_STOPPED) |
91b2f482 | 6525 | return 1; |
a4eaf7f1 | 6526 | |
f5ffe02e FW |
6527 | if (regs) { |
6528 | if (event->attr.exclude_user && user_mode(regs)) | |
6529 | return 1; | |
6530 | ||
6531 | if (event->attr.exclude_kernel && !user_mode(regs)) | |
6532 | return 1; | |
6533 | } | |
6534 | ||
6535 | return 0; | |
6536 | } | |
6537 | ||
cdd6c482 | 6538 | static int perf_swevent_match(struct perf_event *event, |
1c432d89 | 6539 | enum perf_type_id type, |
6fb2915d LZ |
6540 | u32 event_id, |
6541 | struct perf_sample_data *data, | |
6542 | struct pt_regs *regs) | |
15dbf27c | 6543 | { |
cdd6c482 | 6544 | if (event->attr.type != type) |
a21ca2ca | 6545 | return 0; |
f5ffe02e | 6546 | |
cdd6c482 | 6547 | if (event->attr.config != event_id) |
15dbf27c PZ |
6548 | return 0; |
6549 | ||
f5ffe02e FW |
6550 | if (perf_exclude_event(event, regs)) |
6551 | return 0; | |
15dbf27c PZ |
6552 | |
6553 | return 1; | |
6554 | } | |
6555 | ||
76e1d904 FW |
6556 | static inline u64 swevent_hash(u64 type, u32 event_id) |
6557 | { | |
6558 | u64 val = event_id | (type << 32); | |
6559 | ||
6560 | return hash_64(val, SWEVENT_HLIST_BITS); | |
6561 | } | |
6562 | ||
49f135ed FW |
6563 | static inline struct hlist_head * |
6564 | __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) | |
76e1d904 | 6565 | { |
49f135ed FW |
6566 | u64 hash = swevent_hash(type, event_id); |
6567 | ||
6568 | return &hlist->heads[hash]; | |
6569 | } | |
76e1d904 | 6570 | |
49f135ed FW |
6571 | /* For the read side: events when they trigger */ |
6572 | static inline struct hlist_head * | |
b28ab83c | 6573 | find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id) |
49f135ed FW |
6574 | { |
6575 | struct swevent_hlist *hlist; | |
76e1d904 | 6576 | |
b28ab83c | 6577 | hlist = rcu_dereference(swhash->swevent_hlist); |
76e1d904 FW |
6578 | if (!hlist) |
6579 | return NULL; | |
6580 | ||
49f135ed FW |
6581 | return __find_swevent_head(hlist, type, event_id); |
6582 | } | |
6583 | ||
6584 | /* For the event head insertion and removal in the hlist */ | |
6585 | static inline struct hlist_head * | |
b28ab83c | 6586 | find_swevent_head(struct swevent_htable *swhash, struct perf_event *event) |
49f135ed FW |
6587 | { |
6588 | struct swevent_hlist *hlist; | |
6589 | u32 event_id = event->attr.config; | |
6590 | u64 type = event->attr.type; | |
6591 | ||
6592 | /* | |
6593 | * Event scheduling is always serialized against hlist allocation | |
6594 | * and release. Which makes the protected version suitable here. | |
6595 | * The context lock guarantees that. | |
6596 | */ | |
b28ab83c | 6597 | hlist = rcu_dereference_protected(swhash->swevent_hlist, |
49f135ed FW |
6598 | lockdep_is_held(&event->ctx->lock)); |
6599 | if (!hlist) | |
6600 | return NULL; | |
6601 | ||
6602 | return __find_swevent_head(hlist, type, event_id); | |
76e1d904 FW |
6603 | } |
6604 | ||
6605 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, | |
a8b0ca17 | 6606 | u64 nr, |
76e1d904 FW |
6607 | struct perf_sample_data *data, |
6608 | struct pt_regs *regs) | |
15dbf27c | 6609 | { |
4a32fea9 | 6610 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6611 | struct perf_event *event; |
76e1d904 | 6612 | struct hlist_head *head; |
15dbf27c | 6613 | |
76e1d904 | 6614 | rcu_read_lock(); |
b28ab83c | 6615 | head = find_swevent_head_rcu(swhash, type, event_id); |
76e1d904 FW |
6616 | if (!head) |
6617 | goto end; | |
6618 | ||
b67bfe0d | 6619 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
6fb2915d | 6620 | if (perf_swevent_match(event, type, event_id, data, regs)) |
a8b0ca17 | 6621 | perf_swevent_event(event, nr, data, regs); |
15dbf27c | 6622 | } |
76e1d904 FW |
6623 | end: |
6624 | rcu_read_unlock(); | |
15dbf27c PZ |
6625 | } |
6626 | ||
86038c5e PZI |
6627 | DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]); |
6628 | ||
4ed7c92d | 6629 | int perf_swevent_get_recursion_context(void) |
96f6d444 | 6630 | { |
4a32fea9 | 6631 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
96f6d444 | 6632 | |
b28ab83c | 6633 | return get_recursion_context(swhash->recursion); |
96f6d444 | 6634 | } |
645e8cc0 | 6635 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
96f6d444 | 6636 | |
fa9f90be | 6637 | inline void perf_swevent_put_recursion_context(int rctx) |
15dbf27c | 6638 | { |
4a32fea9 | 6639 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
927c7a9e | 6640 | |
b28ab83c | 6641 | put_recursion_context(swhash->recursion, rctx); |
ce71b9df | 6642 | } |
15dbf27c | 6643 | |
86038c5e | 6644 | void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) |
b8e83514 | 6645 | { |
a4234bfc | 6646 | struct perf_sample_data data; |
4ed7c92d | 6647 | |
86038c5e | 6648 | if (WARN_ON_ONCE(!regs)) |
4ed7c92d | 6649 | return; |
a4234bfc | 6650 | |
fd0d000b | 6651 | perf_sample_data_init(&data, addr, 0); |
a8b0ca17 | 6652 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs); |
86038c5e PZI |
6653 | } |
6654 | ||
6655 | void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) | |
6656 | { | |
6657 | int rctx; | |
6658 | ||
6659 | preempt_disable_notrace(); | |
6660 | rctx = perf_swevent_get_recursion_context(); | |
6661 | if (unlikely(rctx < 0)) | |
6662 | goto fail; | |
6663 | ||
6664 | ___perf_sw_event(event_id, nr, regs, addr); | |
4ed7c92d PZ |
6665 | |
6666 | perf_swevent_put_recursion_context(rctx); | |
86038c5e | 6667 | fail: |
1c024eca | 6668 | preempt_enable_notrace(); |
b8e83514 PZ |
6669 | } |
6670 | ||
cdd6c482 | 6671 | static void perf_swevent_read(struct perf_event *event) |
15dbf27c | 6672 | { |
15dbf27c PZ |
6673 | } |
6674 | ||
a4eaf7f1 | 6675 | static int perf_swevent_add(struct perf_event *event, int flags) |
15dbf27c | 6676 | { |
4a32fea9 | 6677 | struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); |
cdd6c482 | 6678 | struct hw_perf_event *hwc = &event->hw; |
76e1d904 FW |
6679 | struct hlist_head *head; |
6680 | ||
6c7e550f | 6681 | if (is_sampling_event(event)) { |
7b4b6658 | 6682 | hwc->last_period = hwc->sample_period; |
cdd6c482 | 6683 | perf_swevent_set_period(event); |
7b4b6658 | 6684 | } |
76e1d904 | 6685 | |
a4eaf7f1 PZ |
6686 | hwc->state = !(flags & PERF_EF_START); |
6687 | ||
b28ab83c | 6688 | head = find_swevent_head(swhash, event); |
12ca6ad2 | 6689 | if (WARN_ON_ONCE(!head)) |
76e1d904 FW |
6690 | return -EINVAL; |
6691 | ||
6692 | hlist_add_head_rcu(&event->hlist_entry, head); | |
6a694a60 | 6693 | perf_event_update_userpage(event); |
76e1d904 | 6694 | |
15dbf27c PZ |
6695 | return 0; |
6696 | } | |
6697 | ||
a4eaf7f1 | 6698 | static void perf_swevent_del(struct perf_event *event, int flags) |
15dbf27c | 6699 | { |
76e1d904 | 6700 | hlist_del_rcu(&event->hlist_entry); |
15dbf27c PZ |
6701 | } |
6702 | ||
a4eaf7f1 | 6703 | static void perf_swevent_start(struct perf_event *event, int flags) |
5c92d124 | 6704 | { |
a4eaf7f1 | 6705 | event->hw.state = 0; |
d6d020e9 | 6706 | } |
aa9c4c0f | 6707 | |
a4eaf7f1 | 6708 | static void perf_swevent_stop(struct perf_event *event, int flags) |
d6d020e9 | 6709 | { |
a4eaf7f1 | 6710 | event->hw.state = PERF_HES_STOPPED; |
bae43c99 IM |
6711 | } |
6712 | ||
49f135ed FW |
6713 | /* Deref the hlist from the update side */ |
6714 | static inline struct swevent_hlist * | |
b28ab83c | 6715 | swevent_hlist_deref(struct swevent_htable *swhash) |
49f135ed | 6716 | { |
b28ab83c PZ |
6717 | return rcu_dereference_protected(swhash->swevent_hlist, |
6718 | lockdep_is_held(&swhash->hlist_mutex)); | |
49f135ed FW |
6719 | } |
6720 | ||
b28ab83c | 6721 | static void swevent_hlist_release(struct swevent_htable *swhash) |
76e1d904 | 6722 | { |
b28ab83c | 6723 | struct swevent_hlist *hlist = swevent_hlist_deref(swhash); |
76e1d904 | 6724 | |
49f135ed | 6725 | if (!hlist) |
76e1d904 FW |
6726 | return; |
6727 | ||
70691d4a | 6728 | RCU_INIT_POINTER(swhash->swevent_hlist, NULL); |
fa4bbc4c | 6729 | kfree_rcu(hlist, rcu_head); |
76e1d904 FW |
6730 | } |
6731 | ||
6732 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) | |
6733 | { | |
b28ab83c | 6734 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 | 6735 | |
b28ab83c | 6736 | mutex_lock(&swhash->hlist_mutex); |
76e1d904 | 6737 | |
b28ab83c PZ |
6738 | if (!--swhash->hlist_refcount) |
6739 | swevent_hlist_release(swhash); | |
76e1d904 | 6740 | |
b28ab83c | 6741 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6742 | } |
6743 | ||
6744 | static void swevent_hlist_put(struct perf_event *event) | |
6745 | { | |
6746 | int cpu; | |
6747 | ||
76e1d904 FW |
6748 | for_each_possible_cpu(cpu) |
6749 | swevent_hlist_put_cpu(event, cpu); | |
6750 | } | |
6751 | ||
6752 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) | |
6753 | { | |
b28ab83c | 6754 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
76e1d904 FW |
6755 | int err = 0; |
6756 | ||
b28ab83c | 6757 | mutex_lock(&swhash->hlist_mutex); |
b28ab83c | 6758 | if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) { |
76e1d904 FW |
6759 | struct swevent_hlist *hlist; |
6760 | ||
6761 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); | |
6762 | if (!hlist) { | |
6763 | err = -ENOMEM; | |
6764 | goto exit; | |
6765 | } | |
b28ab83c | 6766 | rcu_assign_pointer(swhash->swevent_hlist, hlist); |
76e1d904 | 6767 | } |
b28ab83c | 6768 | swhash->hlist_refcount++; |
9ed6060d | 6769 | exit: |
b28ab83c | 6770 | mutex_unlock(&swhash->hlist_mutex); |
76e1d904 FW |
6771 | |
6772 | return err; | |
6773 | } | |
6774 | ||
6775 | static int swevent_hlist_get(struct perf_event *event) | |
6776 | { | |
6777 | int err; | |
6778 | int cpu, failed_cpu; | |
6779 | ||
76e1d904 FW |
6780 | get_online_cpus(); |
6781 | for_each_possible_cpu(cpu) { | |
6782 | err = swevent_hlist_get_cpu(event, cpu); | |
6783 | if (err) { | |
6784 | failed_cpu = cpu; | |
6785 | goto fail; | |
6786 | } | |
6787 | } | |
6788 | put_online_cpus(); | |
6789 | ||
6790 | return 0; | |
9ed6060d | 6791 | fail: |
76e1d904 FW |
6792 | for_each_possible_cpu(cpu) { |
6793 | if (cpu == failed_cpu) | |
6794 | break; | |
6795 | swevent_hlist_put_cpu(event, cpu); | |
6796 | } | |
6797 | ||
6798 | put_online_cpus(); | |
6799 | return err; | |
6800 | } | |
6801 | ||
c5905afb | 6802 | struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
95476b64 | 6803 | |
b0a873eb PZ |
6804 | static void sw_perf_event_destroy(struct perf_event *event) |
6805 | { | |
6806 | u64 event_id = event->attr.config; | |
95476b64 | 6807 | |
b0a873eb PZ |
6808 | WARN_ON(event->parent); |
6809 | ||
c5905afb | 6810 | static_key_slow_dec(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6811 | swevent_hlist_put(event); |
6812 | } | |
6813 | ||
6814 | static int perf_swevent_init(struct perf_event *event) | |
6815 | { | |
8176cced | 6816 | u64 event_id = event->attr.config; |
b0a873eb PZ |
6817 | |
6818 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
6819 | return -ENOENT; | |
6820 | ||
2481c5fa SE |
6821 | /* |
6822 | * no branch sampling for software events | |
6823 | */ | |
6824 | if (has_branch_stack(event)) | |
6825 | return -EOPNOTSUPP; | |
6826 | ||
b0a873eb PZ |
6827 | switch (event_id) { |
6828 | case PERF_COUNT_SW_CPU_CLOCK: | |
6829 | case PERF_COUNT_SW_TASK_CLOCK: | |
6830 | return -ENOENT; | |
6831 | ||
6832 | default: | |
6833 | break; | |
6834 | } | |
6835 | ||
ce677831 | 6836 | if (event_id >= PERF_COUNT_SW_MAX) |
b0a873eb PZ |
6837 | return -ENOENT; |
6838 | ||
6839 | if (!event->parent) { | |
6840 | int err; | |
6841 | ||
6842 | err = swevent_hlist_get(event); | |
6843 | if (err) | |
6844 | return err; | |
6845 | ||
c5905afb | 6846 | static_key_slow_inc(&perf_swevent_enabled[event_id]); |
b0a873eb PZ |
6847 | event->destroy = sw_perf_event_destroy; |
6848 | } | |
6849 | ||
6850 | return 0; | |
6851 | } | |
6852 | ||
6853 | static struct pmu perf_swevent = { | |
89a1e187 | 6854 | .task_ctx_nr = perf_sw_context, |
95476b64 | 6855 | |
34f43927 PZ |
6856 | .capabilities = PERF_PMU_CAP_NO_NMI, |
6857 | ||
b0a873eb | 6858 | .event_init = perf_swevent_init, |
a4eaf7f1 PZ |
6859 | .add = perf_swevent_add, |
6860 | .del = perf_swevent_del, | |
6861 | .start = perf_swevent_start, | |
6862 | .stop = perf_swevent_stop, | |
1c024eca | 6863 | .read = perf_swevent_read, |
1c024eca PZ |
6864 | }; |
6865 | ||
b0a873eb PZ |
6866 | #ifdef CONFIG_EVENT_TRACING |
6867 | ||
1c024eca PZ |
6868 | static int perf_tp_filter_match(struct perf_event *event, |
6869 | struct perf_sample_data *data) | |
6870 | { | |
6871 | void *record = data->raw->data; | |
6872 | ||
b71b437e PZ |
6873 | /* only top level events have filters set */ |
6874 | if (event->parent) | |
6875 | event = event->parent; | |
6876 | ||
1c024eca PZ |
6877 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
6878 | return 1; | |
6879 | return 0; | |
6880 | } | |
6881 | ||
6882 | static int perf_tp_event_match(struct perf_event *event, | |
6883 | struct perf_sample_data *data, | |
6884 | struct pt_regs *regs) | |
6885 | { | |
a0f7d0f7 FW |
6886 | if (event->hw.state & PERF_HES_STOPPED) |
6887 | return 0; | |
580d607c PZ |
6888 | /* |
6889 | * All tracepoints are from kernel-space. | |
6890 | */ | |
6891 | if (event->attr.exclude_kernel) | |
1c024eca PZ |
6892 | return 0; |
6893 | ||
6894 | if (!perf_tp_filter_match(event, data)) | |
6895 | return 0; | |
6896 | ||
6897 | return 1; | |
6898 | } | |
6899 | ||
6900 | void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, | |
e6dab5ff AV |
6901 | struct pt_regs *regs, struct hlist_head *head, int rctx, |
6902 | struct task_struct *task) | |
95476b64 FW |
6903 | { |
6904 | struct perf_sample_data data; | |
1c024eca | 6905 | struct perf_event *event; |
1c024eca | 6906 | |
95476b64 FW |
6907 | struct perf_raw_record raw = { |
6908 | .size = entry_size, | |
6909 | .data = record, | |
6910 | }; | |
6911 | ||
fd0d000b | 6912 | perf_sample_data_init(&data, addr, 0); |
95476b64 FW |
6913 | data.raw = &raw; |
6914 | ||
b67bfe0d | 6915 | hlist_for_each_entry_rcu(event, head, hlist_entry) { |
1c024eca | 6916 | if (perf_tp_event_match(event, &data, regs)) |
a8b0ca17 | 6917 | perf_swevent_event(event, count, &data, regs); |
4f41c013 | 6918 | } |
ecc55f84 | 6919 | |
e6dab5ff AV |
6920 | /* |
6921 | * If we got specified a target task, also iterate its context and | |
6922 | * deliver this event there too. | |
6923 | */ | |
6924 | if (task && task != current) { | |
6925 | struct perf_event_context *ctx; | |
6926 | struct trace_entry *entry = record; | |
6927 | ||
6928 | rcu_read_lock(); | |
6929 | ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]); | |
6930 | if (!ctx) | |
6931 | goto unlock; | |
6932 | ||
6933 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { | |
6934 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6935 | continue; | |
6936 | if (event->attr.config != entry->type) | |
6937 | continue; | |
6938 | if (perf_tp_event_match(event, &data, regs)) | |
6939 | perf_swevent_event(event, count, &data, regs); | |
6940 | } | |
6941 | unlock: | |
6942 | rcu_read_unlock(); | |
6943 | } | |
6944 | ||
ecc55f84 | 6945 | perf_swevent_put_recursion_context(rctx); |
95476b64 FW |
6946 | } |
6947 | EXPORT_SYMBOL_GPL(perf_tp_event); | |
6948 | ||
cdd6c482 | 6949 | static void tp_perf_event_destroy(struct perf_event *event) |
e077df4f | 6950 | { |
1c024eca | 6951 | perf_trace_destroy(event); |
e077df4f PZ |
6952 | } |
6953 | ||
b0a873eb | 6954 | static int perf_tp_event_init(struct perf_event *event) |
e077df4f | 6955 | { |
76e1d904 FW |
6956 | int err; |
6957 | ||
b0a873eb PZ |
6958 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
6959 | return -ENOENT; | |
6960 | ||
2481c5fa SE |
6961 | /* |
6962 | * no branch sampling for tracepoint events | |
6963 | */ | |
6964 | if (has_branch_stack(event)) | |
6965 | return -EOPNOTSUPP; | |
6966 | ||
1c024eca PZ |
6967 | err = perf_trace_init(event); |
6968 | if (err) | |
b0a873eb | 6969 | return err; |
e077df4f | 6970 | |
cdd6c482 | 6971 | event->destroy = tp_perf_event_destroy; |
e077df4f | 6972 | |
b0a873eb PZ |
6973 | return 0; |
6974 | } | |
6975 | ||
6976 | static struct pmu perf_tracepoint = { | |
89a1e187 PZ |
6977 | .task_ctx_nr = perf_sw_context, |
6978 | ||
b0a873eb | 6979 | .event_init = perf_tp_event_init, |
a4eaf7f1 PZ |
6980 | .add = perf_trace_add, |
6981 | .del = perf_trace_del, | |
6982 | .start = perf_swevent_start, | |
6983 | .stop = perf_swevent_stop, | |
b0a873eb | 6984 | .read = perf_swevent_read, |
b0a873eb PZ |
6985 | }; |
6986 | ||
6987 | static inline void perf_tp_register(void) | |
6988 | { | |
2e80a82a | 6989 | perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); |
e077df4f | 6990 | } |
6fb2915d LZ |
6991 | |
6992 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
6993 | { | |
6994 | char *filter_str; | |
6995 | int ret; | |
6996 | ||
6997 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
6998 | return -EINVAL; | |
6999 | ||
7000 | filter_str = strndup_user(arg, PAGE_SIZE); | |
7001 | if (IS_ERR(filter_str)) | |
7002 | return PTR_ERR(filter_str); | |
7003 | ||
7004 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); | |
7005 | ||
7006 | kfree(filter_str); | |
7007 | return ret; | |
7008 | } | |
7009 | ||
7010 | static void perf_event_free_filter(struct perf_event *event) | |
7011 | { | |
7012 | ftrace_profile_free_filter(event); | |
7013 | } | |
7014 | ||
2541517c AS |
7015 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7016 | { | |
7017 | struct bpf_prog *prog; | |
7018 | ||
7019 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
7020 | return -EINVAL; | |
7021 | ||
7022 | if (event->tp_event->prog) | |
7023 | return -EEXIST; | |
7024 | ||
04a22fae WN |
7025 | if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE)) |
7026 | /* bpf programs can only be attached to u/kprobes */ | |
2541517c AS |
7027 | return -EINVAL; |
7028 | ||
7029 | prog = bpf_prog_get(prog_fd); | |
7030 | if (IS_ERR(prog)) | |
7031 | return PTR_ERR(prog); | |
7032 | ||
6c373ca8 | 7033 | if (prog->type != BPF_PROG_TYPE_KPROBE) { |
2541517c AS |
7034 | /* valid fd, but invalid bpf program type */ |
7035 | bpf_prog_put(prog); | |
7036 | return -EINVAL; | |
7037 | } | |
7038 | ||
7039 | event->tp_event->prog = prog; | |
7040 | ||
7041 | return 0; | |
7042 | } | |
7043 | ||
7044 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7045 | { | |
7046 | struct bpf_prog *prog; | |
7047 | ||
7048 | if (!event->tp_event) | |
7049 | return; | |
7050 | ||
7051 | prog = event->tp_event->prog; | |
7052 | if (prog) { | |
7053 | event->tp_event->prog = NULL; | |
7054 | bpf_prog_put(prog); | |
7055 | } | |
7056 | } | |
7057 | ||
e077df4f | 7058 | #else |
6fb2915d | 7059 | |
b0a873eb | 7060 | static inline void perf_tp_register(void) |
e077df4f | 7061 | { |
e077df4f | 7062 | } |
6fb2915d LZ |
7063 | |
7064 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) | |
7065 | { | |
7066 | return -ENOENT; | |
7067 | } | |
7068 | ||
7069 | static void perf_event_free_filter(struct perf_event *event) | |
7070 | { | |
7071 | } | |
7072 | ||
2541517c AS |
7073 | static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) |
7074 | { | |
7075 | return -ENOENT; | |
7076 | } | |
7077 | ||
7078 | static void perf_event_free_bpf_prog(struct perf_event *event) | |
7079 | { | |
7080 | } | |
07b139c8 | 7081 | #endif /* CONFIG_EVENT_TRACING */ |
e077df4f | 7082 | |
24f1e32c | 7083 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
f5ffe02e | 7084 | void perf_bp_event(struct perf_event *bp, void *data) |
24f1e32c | 7085 | { |
f5ffe02e FW |
7086 | struct perf_sample_data sample; |
7087 | struct pt_regs *regs = data; | |
7088 | ||
fd0d000b | 7089 | perf_sample_data_init(&sample, bp->attr.bp_addr, 0); |
f5ffe02e | 7090 | |
a4eaf7f1 | 7091 | if (!bp->hw.state && !perf_exclude_event(bp, regs)) |
a8b0ca17 | 7092 | perf_swevent_event(bp, 1, &sample, regs); |
24f1e32c FW |
7093 | } |
7094 | #endif | |
7095 | ||
b0a873eb PZ |
7096 | /* |
7097 | * hrtimer based swevent callback | |
7098 | */ | |
f29ac756 | 7099 | |
b0a873eb | 7100 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
f29ac756 | 7101 | { |
b0a873eb PZ |
7102 | enum hrtimer_restart ret = HRTIMER_RESTART; |
7103 | struct perf_sample_data data; | |
7104 | struct pt_regs *regs; | |
7105 | struct perf_event *event; | |
7106 | u64 period; | |
f29ac756 | 7107 | |
b0a873eb | 7108 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
ba3dd36c PZ |
7109 | |
7110 | if (event->state != PERF_EVENT_STATE_ACTIVE) | |
7111 | return HRTIMER_NORESTART; | |
7112 | ||
b0a873eb | 7113 | event->pmu->read(event); |
f344011c | 7114 | |
fd0d000b | 7115 | perf_sample_data_init(&data, 0, event->hw.last_period); |
b0a873eb PZ |
7116 | regs = get_irq_regs(); |
7117 | ||
7118 | if (regs && !perf_exclude_event(event, regs)) { | |
77aeeebd | 7119 | if (!(event->attr.exclude_idle && is_idle_task(current))) |
33b07b8b | 7120 | if (__perf_event_overflow(event, 1, &data, regs)) |
b0a873eb PZ |
7121 | ret = HRTIMER_NORESTART; |
7122 | } | |
24f1e32c | 7123 | |
b0a873eb PZ |
7124 | period = max_t(u64, 10000, event->hw.sample_period); |
7125 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); | |
24f1e32c | 7126 | |
b0a873eb | 7127 | return ret; |
f29ac756 PZ |
7128 | } |
7129 | ||
b0a873eb | 7130 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
5c92d124 | 7131 | { |
b0a873eb | 7132 | struct hw_perf_event *hwc = &event->hw; |
5d508e82 FBH |
7133 | s64 period; |
7134 | ||
7135 | if (!is_sampling_event(event)) | |
7136 | return; | |
f5ffe02e | 7137 | |
5d508e82 FBH |
7138 | period = local64_read(&hwc->period_left); |
7139 | if (period) { | |
7140 | if (period < 0) | |
7141 | period = 10000; | |
fa407f35 | 7142 | |
5d508e82 FBH |
7143 | local64_set(&hwc->period_left, 0); |
7144 | } else { | |
7145 | period = max_t(u64, 10000, hwc->sample_period); | |
7146 | } | |
3497d206 TG |
7147 | hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), |
7148 | HRTIMER_MODE_REL_PINNED); | |
24f1e32c | 7149 | } |
b0a873eb PZ |
7150 | |
7151 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) | |
24f1e32c | 7152 | { |
b0a873eb PZ |
7153 | struct hw_perf_event *hwc = &event->hw; |
7154 | ||
6c7e550f | 7155 | if (is_sampling_event(event)) { |
b0a873eb | 7156 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
fa407f35 | 7157 | local64_set(&hwc->period_left, ktime_to_ns(remaining)); |
b0a873eb PZ |
7158 | |
7159 | hrtimer_cancel(&hwc->hrtimer); | |
7160 | } | |
24f1e32c FW |
7161 | } |
7162 | ||
ba3dd36c PZ |
7163 | static void perf_swevent_init_hrtimer(struct perf_event *event) |
7164 | { | |
7165 | struct hw_perf_event *hwc = &event->hw; | |
7166 | ||
7167 | if (!is_sampling_event(event)) | |
7168 | return; | |
7169 | ||
7170 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
7171 | hwc->hrtimer.function = perf_swevent_hrtimer; | |
7172 | ||
7173 | /* | |
7174 | * Since hrtimers have a fixed rate, we can do a static freq->period | |
7175 | * mapping and avoid the whole period adjust feedback stuff. | |
7176 | */ | |
7177 | if (event->attr.freq) { | |
7178 | long freq = event->attr.sample_freq; | |
7179 | ||
7180 | event->attr.sample_period = NSEC_PER_SEC / freq; | |
7181 | hwc->sample_period = event->attr.sample_period; | |
7182 | local64_set(&hwc->period_left, hwc->sample_period); | |
778141e3 | 7183 | hwc->last_period = hwc->sample_period; |
ba3dd36c PZ |
7184 | event->attr.freq = 0; |
7185 | } | |
7186 | } | |
7187 | ||
b0a873eb PZ |
7188 | /* |
7189 | * Software event: cpu wall time clock | |
7190 | */ | |
7191 | ||
7192 | static void cpu_clock_event_update(struct perf_event *event) | |
24f1e32c | 7193 | { |
b0a873eb PZ |
7194 | s64 prev; |
7195 | u64 now; | |
7196 | ||
a4eaf7f1 | 7197 | now = local_clock(); |
b0a873eb PZ |
7198 | prev = local64_xchg(&event->hw.prev_count, now); |
7199 | local64_add(now - prev, &event->count); | |
24f1e32c | 7200 | } |
24f1e32c | 7201 | |
a4eaf7f1 | 7202 | static void cpu_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7203 | { |
a4eaf7f1 | 7204 | local64_set(&event->hw.prev_count, local_clock()); |
b0a873eb | 7205 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7206 | } |
7207 | ||
a4eaf7f1 | 7208 | static void cpu_clock_event_stop(struct perf_event *event, int flags) |
f29ac756 | 7209 | { |
b0a873eb PZ |
7210 | perf_swevent_cancel_hrtimer(event); |
7211 | cpu_clock_event_update(event); | |
7212 | } | |
f29ac756 | 7213 | |
a4eaf7f1 PZ |
7214 | static int cpu_clock_event_add(struct perf_event *event, int flags) |
7215 | { | |
7216 | if (flags & PERF_EF_START) | |
7217 | cpu_clock_event_start(event, flags); | |
6a694a60 | 7218 | perf_event_update_userpage(event); |
a4eaf7f1 PZ |
7219 | |
7220 | return 0; | |
7221 | } | |
7222 | ||
7223 | static void cpu_clock_event_del(struct perf_event *event, int flags) | |
7224 | { | |
7225 | cpu_clock_event_stop(event, flags); | |
7226 | } | |
7227 | ||
b0a873eb PZ |
7228 | static void cpu_clock_event_read(struct perf_event *event) |
7229 | { | |
7230 | cpu_clock_event_update(event); | |
7231 | } | |
f344011c | 7232 | |
b0a873eb PZ |
7233 | static int cpu_clock_event_init(struct perf_event *event) |
7234 | { | |
7235 | if (event->attr.type != PERF_TYPE_SOFTWARE) | |
7236 | return -ENOENT; | |
7237 | ||
7238 | if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) | |
7239 | return -ENOENT; | |
7240 | ||
2481c5fa SE |
7241 | /* |
7242 | * no branch sampling for software events | |
7243 | */ | |
7244 | if (has_branch_stack(event)) | |
7245 | return -EOPNOTSUPP; | |
7246 | ||
ba3dd36c PZ |
7247 | perf_swevent_init_hrtimer(event); |
7248 | ||
b0a873eb | 7249 | return 0; |
f29ac756 PZ |
7250 | } |
7251 | ||
b0a873eb | 7252 | static struct pmu perf_cpu_clock = { |
89a1e187 PZ |
7253 | .task_ctx_nr = perf_sw_context, |
7254 | ||
34f43927 PZ |
7255 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7256 | ||
b0a873eb | 7257 | .event_init = cpu_clock_event_init, |
a4eaf7f1 PZ |
7258 | .add = cpu_clock_event_add, |
7259 | .del = cpu_clock_event_del, | |
7260 | .start = cpu_clock_event_start, | |
7261 | .stop = cpu_clock_event_stop, | |
b0a873eb PZ |
7262 | .read = cpu_clock_event_read, |
7263 | }; | |
7264 | ||
7265 | /* | |
7266 | * Software event: task time clock | |
7267 | */ | |
7268 | ||
7269 | static void task_clock_event_update(struct perf_event *event, u64 now) | |
5c92d124 | 7270 | { |
b0a873eb PZ |
7271 | u64 prev; |
7272 | s64 delta; | |
5c92d124 | 7273 | |
b0a873eb PZ |
7274 | prev = local64_xchg(&event->hw.prev_count, now); |
7275 | delta = now - prev; | |
7276 | local64_add(delta, &event->count); | |
7277 | } | |
5c92d124 | 7278 | |
a4eaf7f1 | 7279 | static void task_clock_event_start(struct perf_event *event, int flags) |
b0a873eb | 7280 | { |
a4eaf7f1 | 7281 | local64_set(&event->hw.prev_count, event->ctx->time); |
b0a873eb | 7282 | perf_swevent_start_hrtimer(event); |
b0a873eb PZ |
7283 | } |
7284 | ||
a4eaf7f1 | 7285 | static void task_clock_event_stop(struct perf_event *event, int flags) |
b0a873eb PZ |
7286 | { |
7287 | perf_swevent_cancel_hrtimer(event); | |
7288 | task_clock_event_update(event, event->ctx->time); | |
a4eaf7f1 PZ |
7289 | } |
7290 | ||
7291 | static int task_clock_event_add(struct perf_event *event, int flags) | |
7292 | { | |
7293 | if (flags & PERF_EF_START) | |
7294 | task_clock_event_start(event, flags); | |
6a694a60 | 7295 | perf_event_update_userpage(event); |
b0a873eb | 7296 | |
a4eaf7f1 PZ |
7297 | return 0; |
7298 | } | |
7299 | ||
7300 | static void task_clock_event_del(struct perf_event *event, int flags) | |
7301 | { | |
7302 | task_clock_event_stop(event, PERF_EF_UPDATE); | |
b0a873eb PZ |
7303 | } |
7304 | ||
7305 | static void task_clock_event_read(struct perf_event *event) | |
7306 | { | |
768a06e2 PZ |
7307 | u64 now = perf_clock(); |
7308 | u64 delta = now - event->ctx->timestamp; | |
7309 | u64 time = event->ctx->time + delta; | |
b0a873eb PZ |
7310 | |
7311 | task_clock_event_update(event, time); | |
7312 | } | |
7313 | ||
7314 | static int task_clock_event_init(struct perf_event *event) | |
6fb2915d | 7315 | { |
b0a873eb PZ |
7316 | if (event->attr.type != PERF_TYPE_SOFTWARE) |
7317 | return -ENOENT; | |
7318 | ||
7319 | if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) | |
7320 | return -ENOENT; | |
7321 | ||
2481c5fa SE |
7322 | /* |
7323 | * no branch sampling for software events | |
7324 | */ | |
7325 | if (has_branch_stack(event)) | |
7326 | return -EOPNOTSUPP; | |
7327 | ||
ba3dd36c PZ |
7328 | perf_swevent_init_hrtimer(event); |
7329 | ||
b0a873eb | 7330 | return 0; |
6fb2915d LZ |
7331 | } |
7332 | ||
b0a873eb | 7333 | static struct pmu perf_task_clock = { |
89a1e187 PZ |
7334 | .task_ctx_nr = perf_sw_context, |
7335 | ||
34f43927 PZ |
7336 | .capabilities = PERF_PMU_CAP_NO_NMI, |
7337 | ||
b0a873eb | 7338 | .event_init = task_clock_event_init, |
a4eaf7f1 PZ |
7339 | .add = task_clock_event_add, |
7340 | .del = task_clock_event_del, | |
7341 | .start = task_clock_event_start, | |
7342 | .stop = task_clock_event_stop, | |
b0a873eb PZ |
7343 | .read = task_clock_event_read, |
7344 | }; | |
6fb2915d | 7345 | |
ad5133b7 | 7346 | static void perf_pmu_nop_void(struct pmu *pmu) |
e077df4f | 7347 | { |
e077df4f | 7348 | } |
6fb2915d | 7349 | |
fbbe0701 SB |
7350 | static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags) |
7351 | { | |
7352 | } | |
7353 | ||
ad5133b7 | 7354 | static int perf_pmu_nop_int(struct pmu *pmu) |
6fb2915d | 7355 | { |
ad5133b7 | 7356 | return 0; |
6fb2915d LZ |
7357 | } |
7358 | ||
18ab2cd3 | 7359 | static DEFINE_PER_CPU(unsigned int, nop_txn_flags); |
fbbe0701 SB |
7360 | |
7361 | static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags) | |
6fb2915d | 7362 | { |
fbbe0701 SB |
7363 | __this_cpu_write(nop_txn_flags, flags); |
7364 | ||
7365 | if (flags & ~PERF_PMU_TXN_ADD) | |
7366 | return; | |
7367 | ||
ad5133b7 | 7368 | perf_pmu_disable(pmu); |
6fb2915d LZ |
7369 | } |
7370 | ||
ad5133b7 PZ |
7371 | static int perf_pmu_commit_txn(struct pmu *pmu) |
7372 | { | |
fbbe0701 SB |
7373 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7374 | ||
7375 | __this_cpu_write(nop_txn_flags, 0); | |
7376 | ||
7377 | if (flags & ~PERF_PMU_TXN_ADD) | |
7378 | return 0; | |
7379 | ||
ad5133b7 PZ |
7380 | perf_pmu_enable(pmu); |
7381 | return 0; | |
7382 | } | |
e077df4f | 7383 | |
ad5133b7 | 7384 | static void perf_pmu_cancel_txn(struct pmu *pmu) |
24f1e32c | 7385 | { |
fbbe0701 SB |
7386 | unsigned int flags = __this_cpu_read(nop_txn_flags); |
7387 | ||
7388 | __this_cpu_write(nop_txn_flags, 0); | |
7389 | ||
7390 | if (flags & ~PERF_PMU_TXN_ADD) | |
7391 | return; | |
7392 | ||
ad5133b7 | 7393 | perf_pmu_enable(pmu); |
24f1e32c FW |
7394 | } |
7395 | ||
35edc2a5 PZ |
7396 | static int perf_event_idx_default(struct perf_event *event) |
7397 | { | |
c719f560 | 7398 | return 0; |
35edc2a5 PZ |
7399 | } |
7400 | ||
8dc85d54 PZ |
7401 | /* |
7402 | * Ensures all contexts with the same task_ctx_nr have the same | |
7403 | * pmu_cpu_context too. | |
7404 | */ | |
9e317041 | 7405 | static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) |
24f1e32c | 7406 | { |
8dc85d54 | 7407 | struct pmu *pmu; |
b326e956 | 7408 | |
8dc85d54 PZ |
7409 | if (ctxn < 0) |
7410 | return NULL; | |
24f1e32c | 7411 | |
8dc85d54 PZ |
7412 | list_for_each_entry(pmu, &pmus, entry) { |
7413 | if (pmu->task_ctx_nr == ctxn) | |
7414 | return pmu->pmu_cpu_context; | |
7415 | } | |
24f1e32c | 7416 | |
8dc85d54 | 7417 | return NULL; |
24f1e32c FW |
7418 | } |
7419 | ||
51676957 | 7420 | static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) |
24f1e32c | 7421 | { |
51676957 PZ |
7422 | int cpu; |
7423 | ||
7424 | for_each_possible_cpu(cpu) { | |
7425 | struct perf_cpu_context *cpuctx; | |
7426 | ||
7427 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7428 | ||
3f1f3320 PZ |
7429 | if (cpuctx->unique_pmu == old_pmu) |
7430 | cpuctx->unique_pmu = pmu; | |
51676957 PZ |
7431 | } |
7432 | } | |
7433 | ||
7434 | static void free_pmu_context(struct pmu *pmu) | |
7435 | { | |
7436 | struct pmu *i; | |
f5ffe02e | 7437 | |
8dc85d54 | 7438 | mutex_lock(&pmus_lock); |
0475f9ea | 7439 | /* |
8dc85d54 | 7440 | * Like a real lame refcount. |
0475f9ea | 7441 | */ |
51676957 PZ |
7442 | list_for_each_entry(i, &pmus, entry) { |
7443 | if (i->pmu_cpu_context == pmu->pmu_cpu_context) { | |
7444 | update_pmu_context(i, pmu); | |
8dc85d54 | 7445 | goto out; |
51676957 | 7446 | } |
8dc85d54 | 7447 | } |
d6d020e9 | 7448 | |
51676957 | 7449 | free_percpu(pmu->pmu_cpu_context); |
8dc85d54 PZ |
7450 | out: |
7451 | mutex_unlock(&pmus_lock); | |
24f1e32c | 7452 | } |
2e80a82a | 7453 | static struct idr pmu_idr; |
d6d020e9 | 7454 | |
abe43400 PZ |
7455 | static ssize_t |
7456 | type_show(struct device *dev, struct device_attribute *attr, char *page) | |
7457 | { | |
7458 | struct pmu *pmu = dev_get_drvdata(dev); | |
7459 | ||
7460 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); | |
7461 | } | |
90826ca7 | 7462 | static DEVICE_ATTR_RO(type); |
abe43400 | 7463 | |
62b85639 SE |
7464 | static ssize_t |
7465 | perf_event_mux_interval_ms_show(struct device *dev, | |
7466 | struct device_attribute *attr, | |
7467 | char *page) | |
7468 | { | |
7469 | struct pmu *pmu = dev_get_drvdata(dev); | |
7470 | ||
7471 | return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); | |
7472 | } | |
7473 | ||
272325c4 PZ |
7474 | static DEFINE_MUTEX(mux_interval_mutex); |
7475 | ||
62b85639 SE |
7476 | static ssize_t |
7477 | perf_event_mux_interval_ms_store(struct device *dev, | |
7478 | struct device_attribute *attr, | |
7479 | const char *buf, size_t count) | |
7480 | { | |
7481 | struct pmu *pmu = dev_get_drvdata(dev); | |
7482 | int timer, cpu, ret; | |
7483 | ||
7484 | ret = kstrtoint(buf, 0, &timer); | |
7485 | if (ret) | |
7486 | return ret; | |
7487 | ||
7488 | if (timer < 1) | |
7489 | return -EINVAL; | |
7490 | ||
7491 | /* same value, noting to do */ | |
7492 | if (timer == pmu->hrtimer_interval_ms) | |
7493 | return count; | |
7494 | ||
272325c4 | 7495 | mutex_lock(&mux_interval_mutex); |
62b85639 SE |
7496 | pmu->hrtimer_interval_ms = timer; |
7497 | ||
7498 | /* update all cpuctx for this PMU */ | |
272325c4 PZ |
7499 | get_online_cpus(); |
7500 | for_each_online_cpu(cpu) { | |
62b85639 SE |
7501 | struct perf_cpu_context *cpuctx; |
7502 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
7503 | cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); | |
7504 | ||
272325c4 PZ |
7505 | cpu_function_call(cpu, |
7506 | (remote_function_f)perf_mux_hrtimer_restart, cpuctx); | |
62b85639 | 7507 | } |
272325c4 PZ |
7508 | put_online_cpus(); |
7509 | mutex_unlock(&mux_interval_mutex); | |
62b85639 SE |
7510 | |
7511 | return count; | |
7512 | } | |
90826ca7 | 7513 | static DEVICE_ATTR_RW(perf_event_mux_interval_ms); |
62b85639 | 7514 | |
90826ca7 GKH |
7515 | static struct attribute *pmu_dev_attrs[] = { |
7516 | &dev_attr_type.attr, | |
7517 | &dev_attr_perf_event_mux_interval_ms.attr, | |
7518 | NULL, | |
abe43400 | 7519 | }; |
90826ca7 | 7520 | ATTRIBUTE_GROUPS(pmu_dev); |
abe43400 PZ |
7521 | |
7522 | static int pmu_bus_running; | |
7523 | static struct bus_type pmu_bus = { | |
7524 | .name = "event_source", | |
90826ca7 | 7525 | .dev_groups = pmu_dev_groups, |
abe43400 PZ |
7526 | }; |
7527 | ||
7528 | static void pmu_dev_release(struct device *dev) | |
7529 | { | |
7530 | kfree(dev); | |
7531 | } | |
7532 | ||
7533 | static int pmu_dev_alloc(struct pmu *pmu) | |
7534 | { | |
7535 | int ret = -ENOMEM; | |
7536 | ||
7537 | pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
7538 | if (!pmu->dev) | |
7539 | goto out; | |
7540 | ||
0c9d42ed | 7541 | pmu->dev->groups = pmu->attr_groups; |
abe43400 PZ |
7542 | device_initialize(pmu->dev); |
7543 | ret = dev_set_name(pmu->dev, "%s", pmu->name); | |
7544 | if (ret) | |
7545 | goto free_dev; | |
7546 | ||
7547 | dev_set_drvdata(pmu->dev, pmu); | |
7548 | pmu->dev->bus = &pmu_bus; | |
7549 | pmu->dev->release = pmu_dev_release; | |
7550 | ret = device_add(pmu->dev); | |
7551 | if (ret) | |
7552 | goto free_dev; | |
7553 | ||
7554 | out: | |
7555 | return ret; | |
7556 | ||
7557 | free_dev: | |
7558 | put_device(pmu->dev); | |
7559 | goto out; | |
7560 | } | |
7561 | ||
547e9fd7 | 7562 | static struct lock_class_key cpuctx_mutex; |
facc4307 | 7563 | static struct lock_class_key cpuctx_lock; |
547e9fd7 | 7564 | |
03d8e80b | 7565 | int perf_pmu_register(struct pmu *pmu, const char *name, int type) |
24f1e32c | 7566 | { |
108b02cf | 7567 | int cpu, ret; |
24f1e32c | 7568 | |
b0a873eb | 7569 | mutex_lock(&pmus_lock); |
33696fc0 PZ |
7570 | ret = -ENOMEM; |
7571 | pmu->pmu_disable_count = alloc_percpu(int); | |
7572 | if (!pmu->pmu_disable_count) | |
7573 | goto unlock; | |
f29ac756 | 7574 | |
2e80a82a PZ |
7575 | pmu->type = -1; |
7576 | if (!name) | |
7577 | goto skip_type; | |
7578 | pmu->name = name; | |
7579 | ||
7580 | if (type < 0) { | |
0e9c3be2 TH |
7581 | type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); |
7582 | if (type < 0) { | |
7583 | ret = type; | |
2e80a82a PZ |
7584 | goto free_pdc; |
7585 | } | |
7586 | } | |
7587 | pmu->type = type; | |
7588 | ||
abe43400 PZ |
7589 | if (pmu_bus_running) { |
7590 | ret = pmu_dev_alloc(pmu); | |
7591 | if (ret) | |
7592 | goto free_idr; | |
7593 | } | |
7594 | ||
2e80a82a | 7595 | skip_type: |
8dc85d54 PZ |
7596 | pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); |
7597 | if (pmu->pmu_cpu_context) | |
7598 | goto got_cpu_context; | |
f29ac756 | 7599 | |
c4814202 | 7600 | ret = -ENOMEM; |
108b02cf PZ |
7601 | pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); |
7602 | if (!pmu->pmu_cpu_context) | |
abe43400 | 7603 | goto free_dev; |
f344011c | 7604 | |
108b02cf PZ |
7605 | for_each_possible_cpu(cpu) { |
7606 | struct perf_cpu_context *cpuctx; | |
7607 | ||
7608 | cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); | |
eb184479 | 7609 | __perf_event_init_context(&cpuctx->ctx); |
547e9fd7 | 7610 | lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); |
facc4307 | 7611 | lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); |
108b02cf | 7612 | cpuctx->ctx.pmu = pmu; |
9e630205 | 7613 | |
272325c4 | 7614 | __perf_mux_hrtimer_init(cpuctx, cpu); |
9e630205 | 7615 | |
3f1f3320 | 7616 | cpuctx->unique_pmu = pmu; |
108b02cf | 7617 | } |
76e1d904 | 7618 | |
8dc85d54 | 7619 | got_cpu_context: |
ad5133b7 PZ |
7620 | if (!pmu->start_txn) { |
7621 | if (pmu->pmu_enable) { | |
7622 | /* | |
7623 | * If we have pmu_enable/pmu_disable calls, install | |
7624 | * transaction stubs that use that to try and batch | |
7625 | * hardware accesses. | |
7626 | */ | |
7627 | pmu->start_txn = perf_pmu_start_txn; | |
7628 | pmu->commit_txn = perf_pmu_commit_txn; | |
7629 | pmu->cancel_txn = perf_pmu_cancel_txn; | |
7630 | } else { | |
fbbe0701 | 7631 | pmu->start_txn = perf_pmu_nop_txn; |
ad5133b7 PZ |
7632 | pmu->commit_txn = perf_pmu_nop_int; |
7633 | pmu->cancel_txn = perf_pmu_nop_void; | |
f344011c | 7634 | } |
5c92d124 | 7635 | } |
15dbf27c | 7636 | |
ad5133b7 PZ |
7637 | if (!pmu->pmu_enable) { |
7638 | pmu->pmu_enable = perf_pmu_nop_void; | |
7639 | pmu->pmu_disable = perf_pmu_nop_void; | |
7640 | } | |
7641 | ||
35edc2a5 PZ |
7642 | if (!pmu->event_idx) |
7643 | pmu->event_idx = perf_event_idx_default; | |
7644 | ||
b0a873eb | 7645 | list_add_rcu(&pmu->entry, &pmus); |
bed5b25a | 7646 | atomic_set(&pmu->exclusive_cnt, 0); |
33696fc0 PZ |
7647 | ret = 0; |
7648 | unlock: | |
b0a873eb PZ |
7649 | mutex_unlock(&pmus_lock); |
7650 | ||
33696fc0 | 7651 | return ret; |
108b02cf | 7652 | |
abe43400 PZ |
7653 | free_dev: |
7654 | device_del(pmu->dev); | |
7655 | put_device(pmu->dev); | |
7656 | ||
2e80a82a PZ |
7657 | free_idr: |
7658 | if (pmu->type >= PERF_TYPE_MAX) | |
7659 | idr_remove(&pmu_idr, pmu->type); | |
7660 | ||
108b02cf PZ |
7661 | free_pdc: |
7662 | free_percpu(pmu->pmu_disable_count); | |
7663 | goto unlock; | |
f29ac756 | 7664 | } |
c464c76e | 7665 | EXPORT_SYMBOL_GPL(perf_pmu_register); |
f29ac756 | 7666 | |
b0a873eb | 7667 | void perf_pmu_unregister(struct pmu *pmu) |
5c92d124 | 7668 | { |
b0a873eb PZ |
7669 | mutex_lock(&pmus_lock); |
7670 | list_del_rcu(&pmu->entry); | |
7671 | mutex_unlock(&pmus_lock); | |
5c92d124 | 7672 | |
0475f9ea | 7673 | /* |
cde8e884 PZ |
7674 | * We dereference the pmu list under both SRCU and regular RCU, so |
7675 | * synchronize against both of those. | |
0475f9ea | 7676 | */ |
b0a873eb | 7677 | synchronize_srcu(&pmus_srcu); |
cde8e884 | 7678 | synchronize_rcu(); |
d6d020e9 | 7679 | |
33696fc0 | 7680 | free_percpu(pmu->pmu_disable_count); |
2e80a82a PZ |
7681 | if (pmu->type >= PERF_TYPE_MAX) |
7682 | idr_remove(&pmu_idr, pmu->type); | |
abe43400 PZ |
7683 | device_del(pmu->dev); |
7684 | put_device(pmu->dev); | |
51676957 | 7685 | free_pmu_context(pmu); |
b0a873eb | 7686 | } |
c464c76e | 7687 | EXPORT_SYMBOL_GPL(perf_pmu_unregister); |
d6d020e9 | 7688 | |
cc34b98b MR |
7689 | static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) |
7690 | { | |
ccd41c86 | 7691 | struct perf_event_context *ctx = NULL; |
cc34b98b MR |
7692 | int ret; |
7693 | ||
7694 | if (!try_module_get(pmu->module)) | |
7695 | return -ENODEV; | |
ccd41c86 PZ |
7696 | |
7697 | if (event->group_leader != event) { | |
8b10c5e2 PZ |
7698 | /* |
7699 | * This ctx->mutex can nest when we're called through | |
7700 | * inheritance. See the perf_event_ctx_lock_nested() comment. | |
7701 | */ | |
7702 | ctx = perf_event_ctx_lock_nested(event->group_leader, | |
7703 | SINGLE_DEPTH_NESTING); | |
ccd41c86 PZ |
7704 | BUG_ON(!ctx); |
7705 | } | |
7706 | ||
cc34b98b MR |
7707 | event->pmu = pmu; |
7708 | ret = pmu->event_init(event); | |
ccd41c86 PZ |
7709 | |
7710 | if (ctx) | |
7711 | perf_event_ctx_unlock(event->group_leader, ctx); | |
7712 | ||
cc34b98b MR |
7713 | if (ret) |
7714 | module_put(pmu->module); | |
7715 | ||
7716 | return ret; | |
7717 | } | |
7718 | ||
18ab2cd3 | 7719 | static struct pmu *perf_init_event(struct perf_event *event) |
b0a873eb PZ |
7720 | { |
7721 | struct pmu *pmu = NULL; | |
7722 | int idx; | |
940c5b29 | 7723 | int ret; |
b0a873eb PZ |
7724 | |
7725 | idx = srcu_read_lock(&pmus_srcu); | |
2e80a82a PZ |
7726 | |
7727 | rcu_read_lock(); | |
7728 | pmu = idr_find(&pmu_idr, event->attr.type); | |
7729 | rcu_read_unlock(); | |
940c5b29 | 7730 | if (pmu) { |
cc34b98b | 7731 | ret = perf_try_init_event(pmu, event); |
940c5b29 LM |
7732 | if (ret) |
7733 | pmu = ERR_PTR(ret); | |
2e80a82a | 7734 | goto unlock; |
940c5b29 | 7735 | } |
2e80a82a | 7736 | |
b0a873eb | 7737 | list_for_each_entry_rcu(pmu, &pmus, entry) { |
cc34b98b | 7738 | ret = perf_try_init_event(pmu, event); |
b0a873eb | 7739 | if (!ret) |
e5f4d339 | 7740 | goto unlock; |
76e1d904 | 7741 | |
b0a873eb PZ |
7742 | if (ret != -ENOENT) { |
7743 | pmu = ERR_PTR(ret); | |
e5f4d339 | 7744 | goto unlock; |
f344011c | 7745 | } |
5c92d124 | 7746 | } |
e5f4d339 PZ |
7747 | pmu = ERR_PTR(-ENOENT); |
7748 | unlock: | |
b0a873eb | 7749 | srcu_read_unlock(&pmus_srcu, idx); |
15dbf27c | 7750 | |
4aeb0b42 | 7751 | return pmu; |
5c92d124 IM |
7752 | } |
7753 | ||
4beb31f3 FW |
7754 | static void account_event_cpu(struct perf_event *event, int cpu) |
7755 | { | |
7756 | if (event->parent) | |
7757 | return; | |
7758 | ||
4beb31f3 FW |
7759 | if (is_cgroup_event(event)) |
7760 | atomic_inc(&per_cpu(perf_cgroup_events, cpu)); | |
7761 | } | |
7762 | ||
766d6c07 FW |
7763 | static void account_event(struct perf_event *event) |
7764 | { | |
4beb31f3 FW |
7765 | if (event->parent) |
7766 | return; | |
7767 | ||
766d6c07 FW |
7768 | if (event->attach_state & PERF_ATTACH_TASK) |
7769 | static_key_slow_inc(&perf_sched_events.key); | |
7770 | if (event->attr.mmap || event->attr.mmap_data) | |
7771 | atomic_inc(&nr_mmap_events); | |
7772 | if (event->attr.comm) | |
7773 | atomic_inc(&nr_comm_events); | |
7774 | if (event->attr.task) | |
7775 | atomic_inc(&nr_task_events); | |
948b26b6 FW |
7776 | if (event->attr.freq) { |
7777 | if (atomic_inc_return(&nr_freq_events) == 1) | |
7778 | tick_nohz_full_kick_all(); | |
7779 | } | |
45ac1403 AH |
7780 | if (event->attr.context_switch) { |
7781 | atomic_inc(&nr_switch_events); | |
7782 | static_key_slow_inc(&perf_sched_events.key); | |
7783 | } | |
4beb31f3 | 7784 | if (has_branch_stack(event)) |
766d6c07 | 7785 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 | 7786 | if (is_cgroup_event(event)) |
766d6c07 | 7787 | static_key_slow_inc(&perf_sched_events.key); |
4beb31f3 FW |
7788 | |
7789 | account_event_cpu(event, event->cpu); | |
766d6c07 FW |
7790 | } |
7791 | ||
0793a61d | 7792 | /* |
cdd6c482 | 7793 | * Allocate and initialize a event structure |
0793a61d | 7794 | */ |
cdd6c482 | 7795 | static struct perf_event * |
c3f00c70 | 7796 | perf_event_alloc(struct perf_event_attr *attr, int cpu, |
d580ff86 PZ |
7797 | struct task_struct *task, |
7798 | struct perf_event *group_leader, | |
7799 | struct perf_event *parent_event, | |
4dc0da86 | 7800 | perf_overflow_handler_t overflow_handler, |
79dff51e | 7801 | void *context, int cgroup_fd) |
0793a61d | 7802 | { |
51b0fe39 | 7803 | struct pmu *pmu; |
cdd6c482 IM |
7804 | struct perf_event *event; |
7805 | struct hw_perf_event *hwc; | |
90983b16 | 7806 | long err = -EINVAL; |
0793a61d | 7807 | |
66832eb4 ON |
7808 | if ((unsigned)cpu >= nr_cpu_ids) { |
7809 | if (!task || cpu != -1) | |
7810 | return ERR_PTR(-EINVAL); | |
7811 | } | |
7812 | ||
c3f00c70 | 7813 | event = kzalloc(sizeof(*event), GFP_KERNEL); |
cdd6c482 | 7814 | if (!event) |
d5d2bc0d | 7815 | return ERR_PTR(-ENOMEM); |
0793a61d | 7816 | |
04289bb9 | 7817 | /* |
cdd6c482 | 7818 | * Single events are their own group leaders, with an |
04289bb9 IM |
7819 | * empty sibling list: |
7820 | */ | |
7821 | if (!group_leader) | |
cdd6c482 | 7822 | group_leader = event; |
04289bb9 | 7823 | |
cdd6c482 IM |
7824 | mutex_init(&event->child_mutex); |
7825 | INIT_LIST_HEAD(&event->child_list); | |
fccc714b | 7826 | |
cdd6c482 IM |
7827 | INIT_LIST_HEAD(&event->group_entry); |
7828 | INIT_LIST_HEAD(&event->event_entry); | |
7829 | INIT_LIST_HEAD(&event->sibling_list); | |
10c6db11 | 7830 | INIT_LIST_HEAD(&event->rb_entry); |
71ad88ef | 7831 | INIT_LIST_HEAD(&event->active_entry); |
f3ae75de SE |
7832 | INIT_HLIST_NODE(&event->hlist_entry); |
7833 | ||
10c6db11 | 7834 | |
cdd6c482 | 7835 | init_waitqueue_head(&event->waitq); |
e360adbe | 7836 | init_irq_work(&event->pending, perf_pending_event); |
0793a61d | 7837 | |
cdd6c482 | 7838 | mutex_init(&event->mmap_mutex); |
7b732a75 | 7839 | |
a6fa941d | 7840 | atomic_long_set(&event->refcount, 1); |
cdd6c482 IM |
7841 | event->cpu = cpu; |
7842 | event->attr = *attr; | |
7843 | event->group_leader = group_leader; | |
7844 | event->pmu = NULL; | |
cdd6c482 | 7845 | event->oncpu = -1; |
a96bbc16 | 7846 | |
cdd6c482 | 7847 | event->parent = parent_event; |
b84fbc9f | 7848 | |
17cf22c3 | 7849 | event->ns = get_pid_ns(task_active_pid_ns(current)); |
cdd6c482 | 7850 | event->id = atomic64_inc_return(&perf_event_id); |
a96bbc16 | 7851 | |
cdd6c482 | 7852 | event->state = PERF_EVENT_STATE_INACTIVE; |
329d876d | 7853 | |
d580ff86 PZ |
7854 | if (task) { |
7855 | event->attach_state = PERF_ATTACH_TASK; | |
d580ff86 | 7856 | /* |
50f16a8b PZ |
7857 | * XXX pmu::event_init needs to know what task to account to |
7858 | * and we cannot use the ctx information because we need the | |
7859 | * pmu before we get a ctx. | |
d580ff86 | 7860 | */ |
50f16a8b | 7861 | event->hw.target = task; |
d580ff86 PZ |
7862 | } |
7863 | ||
34f43927 PZ |
7864 | event->clock = &local_clock; |
7865 | if (parent_event) | |
7866 | event->clock = parent_event->clock; | |
7867 | ||
4dc0da86 | 7868 | if (!overflow_handler && parent_event) { |
b326e956 | 7869 | overflow_handler = parent_event->overflow_handler; |
4dc0da86 AK |
7870 | context = parent_event->overflow_handler_context; |
7871 | } | |
66832eb4 | 7872 | |
b326e956 | 7873 | event->overflow_handler = overflow_handler; |
4dc0da86 | 7874 | event->overflow_handler_context = context; |
97eaf530 | 7875 | |
0231bb53 | 7876 | perf_event__state_init(event); |
a86ed508 | 7877 | |
4aeb0b42 | 7878 | pmu = NULL; |
b8e83514 | 7879 | |
cdd6c482 | 7880 | hwc = &event->hw; |
bd2b5b12 | 7881 | hwc->sample_period = attr->sample_period; |
0d48696f | 7882 | if (attr->freq && attr->sample_freq) |
bd2b5b12 | 7883 | hwc->sample_period = 1; |
eced1dfc | 7884 | hwc->last_period = hwc->sample_period; |
bd2b5b12 | 7885 | |
e7850595 | 7886 | local64_set(&hwc->period_left, hwc->sample_period); |
60db5e09 | 7887 | |
2023b359 | 7888 | /* |
cdd6c482 | 7889 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
2023b359 | 7890 | */ |
3dab77fb | 7891 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
90983b16 | 7892 | goto err_ns; |
a46a2300 YZ |
7893 | |
7894 | if (!has_branch_stack(event)) | |
7895 | event->attr.branch_sample_type = 0; | |
2023b359 | 7896 | |
79dff51e MF |
7897 | if (cgroup_fd != -1) { |
7898 | err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); | |
7899 | if (err) | |
7900 | goto err_ns; | |
7901 | } | |
7902 | ||
b0a873eb | 7903 | pmu = perf_init_event(event); |
4aeb0b42 | 7904 | if (!pmu) |
90983b16 FW |
7905 | goto err_ns; |
7906 | else if (IS_ERR(pmu)) { | |
4aeb0b42 | 7907 | err = PTR_ERR(pmu); |
90983b16 | 7908 | goto err_ns; |
621a01ea | 7909 | } |
d5d2bc0d | 7910 | |
bed5b25a AS |
7911 | err = exclusive_event_init(event); |
7912 | if (err) | |
7913 | goto err_pmu; | |
7914 | ||
cdd6c482 | 7915 | if (!event->parent) { |
927c7a9e FW |
7916 | if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { |
7917 | err = get_callchain_buffers(); | |
90983b16 | 7918 | if (err) |
bed5b25a | 7919 | goto err_per_task; |
d010b332 | 7920 | } |
f344011c | 7921 | } |
9ee318a7 | 7922 | |
cdd6c482 | 7923 | return event; |
90983b16 | 7924 | |
bed5b25a AS |
7925 | err_per_task: |
7926 | exclusive_event_destroy(event); | |
7927 | ||
90983b16 FW |
7928 | err_pmu: |
7929 | if (event->destroy) | |
7930 | event->destroy(event); | |
c464c76e | 7931 | module_put(pmu->module); |
90983b16 | 7932 | err_ns: |
79dff51e MF |
7933 | if (is_cgroup_event(event)) |
7934 | perf_detach_cgroup(event); | |
90983b16 FW |
7935 | if (event->ns) |
7936 | put_pid_ns(event->ns); | |
7937 | kfree(event); | |
7938 | ||
7939 | return ERR_PTR(err); | |
0793a61d TG |
7940 | } |
7941 | ||
cdd6c482 IM |
7942 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
7943 | struct perf_event_attr *attr) | |
974802ea | 7944 | { |
974802ea | 7945 | u32 size; |
cdf8073d | 7946 | int ret; |
974802ea PZ |
7947 | |
7948 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) | |
7949 | return -EFAULT; | |
7950 | ||
7951 | /* | |
7952 | * zero the full structure, so that a short copy will be nice. | |
7953 | */ | |
7954 | memset(attr, 0, sizeof(*attr)); | |
7955 | ||
7956 | ret = get_user(size, &uattr->size); | |
7957 | if (ret) | |
7958 | return ret; | |
7959 | ||
7960 | if (size > PAGE_SIZE) /* silly large */ | |
7961 | goto err_size; | |
7962 | ||
7963 | if (!size) /* abi compat */ | |
7964 | size = PERF_ATTR_SIZE_VER0; | |
7965 | ||
7966 | if (size < PERF_ATTR_SIZE_VER0) | |
7967 | goto err_size; | |
7968 | ||
7969 | /* | |
7970 | * If we're handed a bigger struct than we know of, | |
cdf8073d IS |
7971 | * ensure all the unknown bits are 0 - i.e. new |
7972 | * user-space does not rely on any kernel feature | |
7973 | * extensions we dont know about yet. | |
974802ea PZ |
7974 | */ |
7975 | if (size > sizeof(*attr)) { | |
cdf8073d IS |
7976 | unsigned char __user *addr; |
7977 | unsigned char __user *end; | |
7978 | unsigned char val; | |
974802ea | 7979 | |
cdf8073d IS |
7980 | addr = (void __user *)uattr + sizeof(*attr); |
7981 | end = (void __user *)uattr + size; | |
974802ea | 7982 | |
cdf8073d | 7983 | for (; addr < end; addr++) { |
974802ea PZ |
7984 | ret = get_user(val, addr); |
7985 | if (ret) | |
7986 | return ret; | |
7987 | if (val) | |
7988 | goto err_size; | |
7989 | } | |
b3e62e35 | 7990 | size = sizeof(*attr); |
974802ea PZ |
7991 | } |
7992 | ||
7993 | ret = copy_from_user(attr, uattr, size); | |
7994 | if (ret) | |
7995 | return -EFAULT; | |
7996 | ||
cd757645 | 7997 | if (attr->__reserved_1) |
974802ea PZ |
7998 | return -EINVAL; |
7999 | ||
8000 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) | |
8001 | return -EINVAL; | |
8002 | ||
8003 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) | |
8004 | return -EINVAL; | |
8005 | ||
bce38cd5 SE |
8006 | if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { |
8007 | u64 mask = attr->branch_sample_type; | |
8008 | ||
8009 | /* only using defined bits */ | |
8010 | if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) | |
8011 | return -EINVAL; | |
8012 | ||
8013 | /* at least one branch bit must be set */ | |
8014 | if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) | |
8015 | return -EINVAL; | |
8016 | ||
bce38cd5 SE |
8017 | /* propagate priv level, when not set for branch */ |
8018 | if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) { | |
8019 | ||
8020 | /* exclude_kernel checked on syscall entry */ | |
8021 | if (!attr->exclude_kernel) | |
8022 | mask |= PERF_SAMPLE_BRANCH_KERNEL; | |
8023 | ||
8024 | if (!attr->exclude_user) | |
8025 | mask |= PERF_SAMPLE_BRANCH_USER; | |
8026 | ||
8027 | if (!attr->exclude_hv) | |
8028 | mask |= PERF_SAMPLE_BRANCH_HV; | |
8029 | /* | |
8030 | * adjust user setting (for HW filter setup) | |
8031 | */ | |
8032 | attr->branch_sample_type = mask; | |
8033 | } | |
e712209a SE |
8034 | /* privileged levels capture (kernel, hv): check permissions */ |
8035 | if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) | |
2b923c8f SE |
8036 | && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
8037 | return -EACCES; | |
bce38cd5 | 8038 | } |
4018994f | 8039 | |
c5ebcedb | 8040 | if (attr->sample_type & PERF_SAMPLE_REGS_USER) { |
4018994f | 8041 | ret = perf_reg_validate(attr->sample_regs_user); |
c5ebcedb JO |
8042 | if (ret) |
8043 | return ret; | |
8044 | } | |
8045 | ||
8046 | if (attr->sample_type & PERF_SAMPLE_STACK_USER) { | |
8047 | if (!arch_perf_have_user_stack_dump()) | |
8048 | return -ENOSYS; | |
8049 | ||
8050 | /* | |
8051 | * We have __u32 type for the size, but so far | |
8052 | * we can only use __u16 as maximum due to the | |
8053 | * __u16 sample size limit. | |
8054 | */ | |
8055 | if (attr->sample_stack_user >= USHRT_MAX) | |
8056 | ret = -EINVAL; | |
8057 | else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) | |
8058 | ret = -EINVAL; | |
8059 | } | |
4018994f | 8060 | |
60e2364e SE |
8061 | if (attr->sample_type & PERF_SAMPLE_REGS_INTR) |
8062 | ret = perf_reg_validate(attr->sample_regs_intr); | |
974802ea PZ |
8063 | out: |
8064 | return ret; | |
8065 | ||
8066 | err_size: | |
8067 | put_user(sizeof(*attr), &uattr->size); | |
8068 | ret = -E2BIG; | |
8069 | goto out; | |
8070 | } | |
8071 | ||
ac9721f3 PZ |
8072 | static int |
8073 | perf_event_set_output(struct perf_event *event, struct perf_event *output_event) | |
a4be7c27 | 8074 | { |
b69cf536 | 8075 | struct ring_buffer *rb = NULL; |
a4be7c27 PZ |
8076 | int ret = -EINVAL; |
8077 | ||
ac9721f3 | 8078 | if (!output_event) |
a4be7c27 PZ |
8079 | goto set; |
8080 | ||
ac9721f3 PZ |
8081 | /* don't allow circular references */ |
8082 | if (event == output_event) | |
a4be7c27 PZ |
8083 | goto out; |
8084 | ||
0f139300 PZ |
8085 | /* |
8086 | * Don't allow cross-cpu buffers | |
8087 | */ | |
8088 | if (output_event->cpu != event->cpu) | |
8089 | goto out; | |
8090 | ||
8091 | /* | |
76369139 | 8092 | * If its not a per-cpu rb, it must be the same task. |
0f139300 PZ |
8093 | */ |
8094 | if (output_event->cpu == -1 && output_event->ctx != event->ctx) | |
8095 | goto out; | |
8096 | ||
34f43927 PZ |
8097 | /* |
8098 | * Mixing clocks in the same buffer is trouble you don't need. | |
8099 | */ | |
8100 | if (output_event->clock != event->clock) | |
8101 | goto out; | |
8102 | ||
45bfb2e5 PZ |
8103 | /* |
8104 | * If both events generate aux data, they must be on the same PMU | |
8105 | */ | |
8106 | if (has_aux(event) && has_aux(output_event) && | |
8107 | event->pmu != output_event->pmu) | |
8108 | goto out; | |
8109 | ||
a4be7c27 | 8110 | set: |
cdd6c482 | 8111 | mutex_lock(&event->mmap_mutex); |
ac9721f3 PZ |
8112 | /* Can't redirect output if we've got an active mmap() */ |
8113 | if (atomic_read(&event->mmap_count)) | |
8114 | goto unlock; | |
a4be7c27 | 8115 | |
ac9721f3 | 8116 | if (output_event) { |
76369139 FW |
8117 | /* get the rb we want to redirect to */ |
8118 | rb = ring_buffer_get(output_event); | |
8119 | if (!rb) | |
ac9721f3 | 8120 | goto unlock; |
a4be7c27 PZ |
8121 | } |
8122 | ||
b69cf536 | 8123 | ring_buffer_attach(event, rb); |
9bb5d40c | 8124 | |
a4be7c27 | 8125 | ret = 0; |
ac9721f3 PZ |
8126 | unlock: |
8127 | mutex_unlock(&event->mmap_mutex); | |
8128 | ||
a4be7c27 | 8129 | out: |
a4be7c27 PZ |
8130 | return ret; |
8131 | } | |
8132 | ||
f63a8daa PZ |
8133 | static void mutex_lock_double(struct mutex *a, struct mutex *b) |
8134 | { | |
8135 | if (b < a) | |
8136 | swap(a, b); | |
8137 | ||
8138 | mutex_lock(a); | |
8139 | mutex_lock_nested(b, SINGLE_DEPTH_NESTING); | |
8140 | } | |
8141 | ||
34f43927 PZ |
8142 | static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) |
8143 | { | |
8144 | bool nmi_safe = false; | |
8145 | ||
8146 | switch (clk_id) { | |
8147 | case CLOCK_MONOTONIC: | |
8148 | event->clock = &ktime_get_mono_fast_ns; | |
8149 | nmi_safe = true; | |
8150 | break; | |
8151 | ||
8152 | case CLOCK_MONOTONIC_RAW: | |
8153 | event->clock = &ktime_get_raw_fast_ns; | |
8154 | nmi_safe = true; | |
8155 | break; | |
8156 | ||
8157 | case CLOCK_REALTIME: | |
8158 | event->clock = &ktime_get_real_ns; | |
8159 | break; | |
8160 | ||
8161 | case CLOCK_BOOTTIME: | |
8162 | event->clock = &ktime_get_boot_ns; | |
8163 | break; | |
8164 | ||
8165 | case CLOCK_TAI: | |
8166 | event->clock = &ktime_get_tai_ns; | |
8167 | break; | |
8168 | ||
8169 | default: | |
8170 | return -EINVAL; | |
8171 | } | |
8172 | ||
8173 | if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) | |
8174 | return -EINVAL; | |
8175 | ||
8176 | return 0; | |
8177 | } | |
8178 | ||
0793a61d | 8179 | /** |
cdd6c482 | 8180 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
9f66a381 | 8181 | * |
cdd6c482 | 8182 | * @attr_uptr: event_id type attributes for monitoring/sampling |
0793a61d | 8183 | * @pid: target pid |
9f66a381 | 8184 | * @cpu: target cpu |
cdd6c482 | 8185 | * @group_fd: group leader event fd |
0793a61d | 8186 | */ |
cdd6c482 IM |
8187 | SYSCALL_DEFINE5(perf_event_open, |
8188 | struct perf_event_attr __user *, attr_uptr, | |
2743a5b0 | 8189 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 8190 | { |
b04243ef PZ |
8191 | struct perf_event *group_leader = NULL, *output_event = NULL; |
8192 | struct perf_event *event, *sibling; | |
cdd6c482 | 8193 | struct perf_event_attr attr; |
f63a8daa | 8194 | struct perf_event_context *ctx, *uninitialized_var(gctx); |
cdd6c482 | 8195 | struct file *event_file = NULL; |
2903ff01 | 8196 | struct fd group = {NULL, 0}; |
38a81da2 | 8197 | struct task_struct *task = NULL; |
89a1e187 | 8198 | struct pmu *pmu; |
ea635c64 | 8199 | int event_fd; |
b04243ef | 8200 | int move_group = 0; |
dc86cabe | 8201 | int err; |
a21b0b35 | 8202 | int f_flags = O_RDWR; |
79dff51e | 8203 | int cgroup_fd = -1; |
0793a61d | 8204 | |
2743a5b0 | 8205 | /* for future expandability... */ |
e5d1367f | 8206 | if (flags & ~PERF_FLAG_ALL) |
2743a5b0 PM |
8207 | return -EINVAL; |
8208 | ||
dc86cabe IM |
8209 | err = perf_copy_attr(attr_uptr, &attr); |
8210 | if (err) | |
8211 | return err; | |
eab656ae | 8212 | |
0764771d PZ |
8213 | if (!attr.exclude_kernel) { |
8214 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) | |
8215 | return -EACCES; | |
8216 | } | |
8217 | ||
df58ab24 | 8218 | if (attr.freq) { |
cdd6c482 | 8219 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
df58ab24 | 8220 | return -EINVAL; |
0819b2e3 PZ |
8221 | } else { |
8222 | if (attr.sample_period & (1ULL << 63)) | |
8223 | return -EINVAL; | |
df58ab24 PZ |
8224 | } |
8225 | ||
e5d1367f SE |
8226 | /* |
8227 | * In cgroup mode, the pid argument is used to pass the fd | |
8228 | * opened to the cgroup directory in cgroupfs. The cpu argument | |
8229 | * designates the cpu on which to monitor threads from that | |
8230 | * cgroup. | |
8231 | */ | |
8232 | if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) | |
8233 | return -EINVAL; | |
8234 | ||
a21b0b35 YD |
8235 | if (flags & PERF_FLAG_FD_CLOEXEC) |
8236 | f_flags |= O_CLOEXEC; | |
8237 | ||
8238 | event_fd = get_unused_fd_flags(f_flags); | |
ea635c64 AV |
8239 | if (event_fd < 0) |
8240 | return event_fd; | |
8241 | ||
ac9721f3 | 8242 | if (group_fd != -1) { |
2903ff01 AV |
8243 | err = perf_fget_light(group_fd, &group); |
8244 | if (err) | |
d14b12d7 | 8245 | goto err_fd; |
2903ff01 | 8246 | group_leader = group.file->private_data; |
ac9721f3 PZ |
8247 | if (flags & PERF_FLAG_FD_OUTPUT) |
8248 | output_event = group_leader; | |
8249 | if (flags & PERF_FLAG_FD_NO_GROUP) | |
8250 | group_leader = NULL; | |
8251 | } | |
8252 | ||
e5d1367f | 8253 | if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { |
c6be5a5c PZ |
8254 | task = find_lively_task_by_vpid(pid); |
8255 | if (IS_ERR(task)) { | |
8256 | err = PTR_ERR(task); | |
8257 | goto err_group_fd; | |
8258 | } | |
8259 | } | |
8260 | ||
1f4ee503 PZ |
8261 | if (task && group_leader && |
8262 | group_leader->attr.inherit != attr.inherit) { | |
8263 | err = -EINVAL; | |
8264 | goto err_task; | |
8265 | } | |
8266 | ||
fbfc623f YZ |
8267 | get_online_cpus(); |
8268 | ||
79dff51e MF |
8269 | if (flags & PERF_FLAG_PID_CGROUP) |
8270 | cgroup_fd = pid; | |
8271 | ||
4dc0da86 | 8272 | event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, |
79dff51e | 8273 | NULL, NULL, cgroup_fd); |
d14b12d7 SE |
8274 | if (IS_ERR(event)) { |
8275 | err = PTR_ERR(event); | |
1f4ee503 | 8276 | goto err_cpus; |
d14b12d7 SE |
8277 | } |
8278 | ||
53b25335 VW |
8279 | if (is_sampling_event(event)) { |
8280 | if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { | |
8281 | err = -ENOTSUPP; | |
8282 | goto err_alloc; | |
8283 | } | |
8284 | } | |
8285 | ||
766d6c07 FW |
8286 | account_event(event); |
8287 | ||
89a1e187 PZ |
8288 | /* |
8289 | * Special case software events and allow them to be part of | |
8290 | * any hardware group. | |
8291 | */ | |
8292 | pmu = event->pmu; | |
b04243ef | 8293 | |
34f43927 PZ |
8294 | if (attr.use_clockid) { |
8295 | err = perf_event_set_clock(event, attr.clockid); | |
8296 | if (err) | |
8297 | goto err_alloc; | |
8298 | } | |
8299 | ||
b04243ef PZ |
8300 | if (group_leader && |
8301 | (is_software_event(event) != is_software_event(group_leader))) { | |
8302 | if (is_software_event(event)) { | |
8303 | /* | |
8304 | * If event and group_leader are not both a software | |
8305 | * event, and event is, then group leader is not. | |
8306 | * | |
8307 | * Allow the addition of software events to !software | |
8308 | * groups, this is safe because software events never | |
8309 | * fail to schedule. | |
8310 | */ | |
8311 | pmu = group_leader->pmu; | |
8312 | } else if (is_software_event(group_leader) && | |
8313 | (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { | |
8314 | /* | |
8315 | * In case the group is a pure software group, and we | |
8316 | * try to add a hardware event, move the whole group to | |
8317 | * the hardware context. | |
8318 | */ | |
8319 | move_group = 1; | |
8320 | } | |
8321 | } | |
89a1e187 PZ |
8322 | |
8323 | /* | |
8324 | * Get the target context (task or percpu): | |
8325 | */ | |
4af57ef2 | 8326 | ctx = find_get_context(pmu, task, event); |
89a1e187 PZ |
8327 | if (IS_ERR(ctx)) { |
8328 | err = PTR_ERR(ctx); | |
c6be5a5c | 8329 | goto err_alloc; |
89a1e187 PZ |
8330 | } |
8331 | ||
bed5b25a AS |
8332 | if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) { |
8333 | err = -EBUSY; | |
8334 | goto err_context; | |
8335 | } | |
8336 | ||
fd1edb3a PZ |
8337 | if (task) { |
8338 | put_task_struct(task); | |
8339 | task = NULL; | |
8340 | } | |
8341 | ||
ccff286d | 8342 | /* |
cdd6c482 | 8343 | * Look up the group leader (we will attach this event to it): |
04289bb9 | 8344 | */ |
ac9721f3 | 8345 | if (group_leader) { |
dc86cabe | 8346 | err = -EINVAL; |
04289bb9 | 8347 | |
04289bb9 | 8348 | /* |
ccff286d IM |
8349 | * Do not allow a recursive hierarchy (this new sibling |
8350 | * becoming part of another group-sibling): | |
8351 | */ | |
8352 | if (group_leader->group_leader != group_leader) | |
c3f00c70 | 8353 | goto err_context; |
34f43927 PZ |
8354 | |
8355 | /* All events in a group should have the same clock */ | |
8356 | if (group_leader->clock != event->clock) | |
8357 | goto err_context; | |
8358 | ||
ccff286d IM |
8359 | /* |
8360 | * Do not allow to attach to a group in a different | |
8361 | * task or CPU context: | |
04289bb9 | 8362 | */ |
b04243ef | 8363 | if (move_group) { |
c3c87e77 PZ |
8364 | /* |
8365 | * Make sure we're both on the same task, or both | |
8366 | * per-cpu events. | |
8367 | */ | |
8368 | if (group_leader->ctx->task != ctx->task) | |
8369 | goto err_context; | |
8370 | ||
8371 | /* | |
8372 | * Make sure we're both events for the same CPU; | |
8373 | * grouping events for different CPUs is broken; since | |
8374 | * you can never concurrently schedule them anyhow. | |
8375 | */ | |
8376 | if (group_leader->cpu != event->cpu) | |
b04243ef PZ |
8377 | goto err_context; |
8378 | } else { | |
8379 | if (group_leader->ctx != ctx) | |
8380 | goto err_context; | |
8381 | } | |
8382 | ||
3b6f9e5c PM |
8383 | /* |
8384 | * Only a group leader can be exclusive or pinned | |
8385 | */ | |
0d48696f | 8386 | if (attr.exclusive || attr.pinned) |
c3f00c70 | 8387 | goto err_context; |
ac9721f3 PZ |
8388 | } |
8389 | ||
8390 | if (output_event) { | |
8391 | err = perf_event_set_output(event, output_event); | |
8392 | if (err) | |
c3f00c70 | 8393 | goto err_context; |
ac9721f3 | 8394 | } |
0793a61d | 8395 | |
a21b0b35 YD |
8396 | event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, |
8397 | f_flags); | |
ea635c64 AV |
8398 | if (IS_ERR(event_file)) { |
8399 | err = PTR_ERR(event_file); | |
c3f00c70 | 8400 | goto err_context; |
ea635c64 | 8401 | } |
9b51f66d | 8402 | |
b04243ef | 8403 | if (move_group) { |
f63a8daa | 8404 | gctx = group_leader->ctx; |
f55fc2a5 PZ |
8405 | mutex_lock_double(&gctx->mutex, &ctx->mutex); |
8406 | } else { | |
8407 | mutex_lock(&ctx->mutex); | |
8408 | } | |
8409 | ||
a723968c PZ |
8410 | if (!perf_event_validate_size(event)) { |
8411 | err = -E2BIG; | |
8412 | goto err_locked; | |
8413 | } | |
8414 | ||
f55fc2a5 PZ |
8415 | /* |
8416 | * Must be under the same ctx::mutex as perf_install_in_context(), | |
8417 | * because we need to serialize with concurrent event creation. | |
8418 | */ | |
8419 | if (!exclusive_event_installable(event, ctx)) { | |
8420 | /* exclusive and group stuff are assumed mutually exclusive */ | |
8421 | WARN_ON_ONCE(move_group); | |
f63a8daa | 8422 | |
f55fc2a5 PZ |
8423 | err = -EBUSY; |
8424 | goto err_locked; | |
8425 | } | |
f63a8daa | 8426 | |
f55fc2a5 PZ |
8427 | WARN_ON_ONCE(ctx->parent_ctx); |
8428 | ||
8429 | if (move_group) { | |
f63a8daa PZ |
8430 | /* |
8431 | * See perf_event_ctx_lock() for comments on the details | |
8432 | * of swizzling perf_event::ctx. | |
8433 | */ | |
46ce0fe9 | 8434 | perf_remove_from_context(group_leader, false); |
0231bb53 | 8435 | |
b04243ef PZ |
8436 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8437 | group_entry) { | |
46ce0fe9 | 8438 | perf_remove_from_context(sibling, false); |
b04243ef PZ |
8439 | put_ctx(gctx); |
8440 | } | |
b04243ef | 8441 | |
f63a8daa PZ |
8442 | /* |
8443 | * Wait for everybody to stop referencing the events through | |
8444 | * the old lists, before installing it on new lists. | |
8445 | */ | |
0cda4c02 | 8446 | synchronize_rcu(); |
f63a8daa | 8447 | |
8f95b435 PZI |
8448 | /* |
8449 | * Install the group siblings before the group leader. | |
8450 | * | |
8451 | * Because a group leader will try and install the entire group | |
8452 | * (through the sibling list, which is still in-tact), we can | |
8453 | * end up with siblings installed in the wrong context. | |
8454 | * | |
8455 | * By installing siblings first we NO-OP because they're not | |
8456 | * reachable through the group lists. | |
8457 | */ | |
b04243ef PZ |
8458 | list_for_each_entry(sibling, &group_leader->sibling_list, |
8459 | group_entry) { | |
8f95b435 | 8460 | perf_event__state_init(sibling); |
9fc81d87 | 8461 | perf_install_in_context(ctx, sibling, sibling->cpu); |
b04243ef PZ |
8462 | get_ctx(ctx); |
8463 | } | |
8f95b435 PZI |
8464 | |
8465 | /* | |
8466 | * Removing from the context ends up with disabled | |
8467 | * event. What we want here is event in the initial | |
8468 | * startup state, ready to be add into new context. | |
8469 | */ | |
8470 | perf_event__state_init(group_leader); | |
8471 | perf_install_in_context(ctx, group_leader, group_leader->cpu); | |
8472 | get_ctx(ctx); | |
b04243ef | 8473 | |
f55fc2a5 PZ |
8474 | /* |
8475 | * Now that all events are installed in @ctx, nothing | |
8476 | * references @gctx anymore, so drop the last reference we have | |
8477 | * on it. | |
8478 | */ | |
8479 | put_ctx(gctx); | |
bed5b25a AS |
8480 | } |
8481 | ||
f73e22ab PZ |
8482 | /* |
8483 | * Precalculate sample_data sizes; do while holding ctx::mutex such | |
8484 | * that we're serialized against further additions and before | |
8485 | * perf_install_in_context() which is the point the event is active and | |
8486 | * can use these values. | |
8487 | */ | |
8488 | perf_event__header_size(event); | |
8489 | perf_event__id_header_size(event); | |
8490 | ||
e2d37cd2 | 8491 | perf_install_in_context(ctx, event, event->cpu); |
fe4b04fa | 8492 | perf_unpin_context(ctx); |
f63a8daa | 8493 | |
f55fc2a5 | 8494 | if (move_group) |
f63a8daa | 8495 | mutex_unlock(&gctx->mutex); |
d859e29f | 8496 | mutex_unlock(&ctx->mutex); |
9b51f66d | 8497 | |
fbfc623f YZ |
8498 | put_online_cpus(); |
8499 | ||
cdd6c482 | 8500 | event->owner = current; |
8882135b | 8501 | |
cdd6c482 IM |
8502 | mutex_lock(¤t->perf_event_mutex); |
8503 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); | |
8504 | mutex_unlock(¤t->perf_event_mutex); | |
082ff5a2 | 8505 | |
8a49542c PZ |
8506 | /* |
8507 | * Drop the reference on the group_event after placing the | |
8508 | * new event on the sibling_list. This ensures destruction | |
8509 | * of the group leader will find the pointer to itself in | |
8510 | * perf_group_detach(). | |
8511 | */ | |
2903ff01 | 8512 | fdput(group); |
ea635c64 AV |
8513 | fd_install(event_fd, event_file); |
8514 | return event_fd; | |
0793a61d | 8515 | |
f55fc2a5 PZ |
8516 | err_locked: |
8517 | if (move_group) | |
8518 | mutex_unlock(&gctx->mutex); | |
8519 | mutex_unlock(&ctx->mutex); | |
8520 | /* err_file: */ | |
8521 | fput(event_file); | |
c3f00c70 | 8522 | err_context: |
fe4b04fa | 8523 | perf_unpin_context(ctx); |
ea635c64 | 8524 | put_ctx(ctx); |
c6be5a5c | 8525 | err_alloc: |
ea635c64 | 8526 | free_event(event); |
1f4ee503 | 8527 | err_cpus: |
fbfc623f | 8528 | put_online_cpus(); |
1f4ee503 | 8529 | err_task: |
e7d0bc04 PZ |
8530 | if (task) |
8531 | put_task_struct(task); | |
89a1e187 | 8532 | err_group_fd: |
2903ff01 | 8533 | fdput(group); |
ea635c64 AV |
8534 | err_fd: |
8535 | put_unused_fd(event_fd); | |
dc86cabe | 8536 | return err; |
0793a61d TG |
8537 | } |
8538 | ||
fb0459d7 AV |
8539 | /** |
8540 | * perf_event_create_kernel_counter | |
8541 | * | |
8542 | * @attr: attributes of the counter to create | |
8543 | * @cpu: cpu in which the counter is bound | |
38a81da2 | 8544 | * @task: task to profile (NULL for percpu) |
fb0459d7 AV |
8545 | */ |
8546 | struct perf_event * | |
8547 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, | |
38a81da2 | 8548 | struct task_struct *task, |
4dc0da86 AK |
8549 | perf_overflow_handler_t overflow_handler, |
8550 | void *context) | |
fb0459d7 | 8551 | { |
fb0459d7 | 8552 | struct perf_event_context *ctx; |
c3f00c70 | 8553 | struct perf_event *event; |
fb0459d7 | 8554 | int err; |
d859e29f | 8555 | |
fb0459d7 AV |
8556 | /* |
8557 | * Get the target context (task or percpu): | |
8558 | */ | |
d859e29f | 8559 | |
4dc0da86 | 8560 | event = perf_event_alloc(attr, cpu, task, NULL, NULL, |
79dff51e | 8561 | overflow_handler, context, -1); |
c3f00c70 PZ |
8562 | if (IS_ERR(event)) { |
8563 | err = PTR_ERR(event); | |
8564 | goto err; | |
8565 | } | |
d859e29f | 8566 | |
f8697762 JO |
8567 | /* Mark owner so we could distinguish it from user events. */ |
8568 | event->owner = EVENT_OWNER_KERNEL; | |
8569 | ||
766d6c07 FW |
8570 | account_event(event); |
8571 | ||
4af57ef2 | 8572 | ctx = find_get_context(event->pmu, task, event); |
c6567f64 FW |
8573 | if (IS_ERR(ctx)) { |
8574 | err = PTR_ERR(ctx); | |
c3f00c70 | 8575 | goto err_free; |
d859e29f | 8576 | } |
fb0459d7 | 8577 | |
fb0459d7 AV |
8578 | WARN_ON_ONCE(ctx->parent_ctx); |
8579 | mutex_lock(&ctx->mutex); | |
bed5b25a AS |
8580 | if (!exclusive_event_installable(event, ctx)) { |
8581 | mutex_unlock(&ctx->mutex); | |
8582 | perf_unpin_context(ctx); | |
8583 | put_ctx(ctx); | |
8584 | err = -EBUSY; | |
8585 | goto err_free; | |
8586 | } | |
8587 | ||
fb0459d7 | 8588 | perf_install_in_context(ctx, event, cpu); |
fe4b04fa | 8589 | perf_unpin_context(ctx); |
fb0459d7 AV |
8590 | mutex_unlock(&ctx->mutex); |
8591 | ||
fb0459d7 AV |
8592 | return event; |
8593 | ||
c3f00c70 PZ |
8594 | err_free: |
8595 | free_event(event); | |
8596 | err: | |
c6567f64 | 8597 | return ERR_PTR(err); |
9b51f66d | 8598 | } |
fb0459d7 | 8599 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
9b51f66d | 8600 | |
0cda4c02 YZ |
8601 | void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) |
8602 | { | |
8603 | struct perf_event_context *src_ctx; | |
8604 | struct perf_event_context *dst_ctx; | |
8605 | struct perf_event *event, *tmp; | |
8606 | LIST_HEAD(events); | |
8607 | ||
8608 | src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx; | |
8609 | dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx; | |
8610 | ||
f63a8daa PZ |
8611 | /* |
8612 | * See perf_event_ctx_lock() for comments on the details | |
8613 | * of swizzling perf_event::ctx. | |
8614 | */ | |
8615 | mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex); | |
0cda4c02 YZ |
8616 | list_for_each_entry_safe(event, tmp, &src_ctx->event_list, |
8617 | event_entry) { | |
46ce0fe9 | 8618 | perf_remove_from_context(event, false); |
9a545de0 | 8619 | unaccount_event_cpu(event, src_cpu); |
0cda4c02 | 8620 | put_ctx(src_ctx); |
9886167d | 8621 | list_add(&event->migrate_entry, &events); |
0cda4c02 | 8622 | } |
0cda4c02 | 8623 | |
8f95b435 PZI |
8624 | /* |
8625 | * Wait for the events to quiesce before re-instating them. | |
8626 | */ | |
0cda4c02 YZ |
8627 | synchronize_rcu(); |
8628 | ||
8f95b435 PZI |
8629 | /* |
8630 | * Re-instate events in 2 passes. | |
8631 | * | |
8632 | * Skip over group leaders and only install siblings on this first | |
8633 | * pass, siblings will not get enabled without a leader, however a | |
8634 | * leader will enable its siblings, even if those are still on the old | |
8635 | * context. | |
8636 | */ | |
8637 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { | |
8638 | if (event->group_leader == event) | |
8639 | continue; | |
8640 | ||
8641 | list_del(&event->migrate_entry); | |
8642 | if (event->state >= PERF_EVENT_STATE_OFF) | |
8643 | event->state = PERF_EVENT_STATE_INACTIVE; | |
8644 | account_event_cpu(event, dst_cpu); | |
8645 | perf_install_in_context(dst_ctx, event, dst_cpu); | |
8646 | get_ctx(dst_ctx); | |
8647 | } | |
8648 | ||
8649 | /* | |
8650 | * Once all the siblings are setup properly, install the group leaders | |
8651 | * to make it go. | |
8652 | */ | |
9886167d PZ |
8653 | list_for_each_entry_safe(event, tmp, &events, migrate_entry) { |
8654 | list_del(&event->migrate_entry); | |
0cda4c02 YZ |
8655 | if (event->state >= PERF_EVENT_STATE_OFF) |
8656 | event->state = PERF_EVENT_STATE_INACTIVE; | |
9a545de0 | 8657 | account_event_cpu(event, dst_cpu); |
0cda4c02 YZ |
8658 | perf_install_in_context(dst_ctx, event, dst_cpu); |
8659 | get_ctx(dst_ctx); | |
8660 | } | |
8661 | mutex_unlock(&dst_ctx->mutex); | |
f63a8daa | 8662 | mutex_unlock(&src_ctx->mutex); |
0cda4c02 YZ |
8663 | } |
8664 | EXPORT_SYMBOL_GPL(perf_pmu_migrate_context); | |
8665 | ||
cdd6c482 | 8666 | static void sync_child_event(struct perf_event *child_event, |
38b200d6 | 8667 | struct task_struct *child) |
d859e29f | 8668 | { |
cdd6c482 | 8669 | struct perf_event *parent_event = child_event->parent; |
8bc20959 | 8670 | u64 child_val; |
d859e29f | 8671 | |
cdd6c482 IM |
8672 | if (child_event->attr.inherit_stat) |
8673 | perf_event_read_event(child_event, child); | |
38b200d6 | 8674 | |
b5e58793 | 8675 | child_val = perf_event_count(child_event); |
d859e29f PM |
8676 | |
8677 | /* | |
8678 | * Add back the child's count to the parent's count: | |
8679 | */ | |
a6e6dea6 | 8680 | atomic64_add(child_val, &parent_event->child_count); |
cdd6c482 IM |
8681 | atomic64_add(child_event->total_time_enabled, |
8682 | &parent_event->child_total_time_enabled); | |
8683 | atomic64_add(child_event->total_time_running, | |
8684 | &parent_event->child_total_time_running); | |
d859e29f PM |
8685 | |
8686 | /* | |
cdd6c482 | 8687 | * Remove this event from the parent's list |
d859e29f | 8688 | */ |
cdd6c482 IM |
8689 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
8690 | mutex_lock(&parent_event->child_mutex); | |
8691 | list_del_init(&child_event->child_list); | |
8692 | mutex_unlock(&parent_event->child_mutex); | |
d859e29f | 8693 | |
dc633982 JO |
8694 | /* |
8695 | * Make sure user/parent get notified, that we just | |
8696 | * lost one event. | |
8697 | */ | |
8698 | perf_event_wakeup(parent_event); | |
8699 | ||
d859e29f | 8700 | /* |
cdd6c482 | 8701 | * Release the parent event, if this was the last |
d859e29f PM |
8702 | * reference to it. |
8703 | */ | |
a6fa941d | 8704 | put_event(parent_event); |
d859e29f PM |
8705 | } |
8706 | ||
9b51f66d | 8707 | static void |
cdd6c482 IM |
8708 | __perf_event_exit_task(struct perf_event *child_event, |
8709 | struct perf_event_context *child_ctx, | |
38b200d6 | 8710 | struct task_struct *child) |
9b51f66d | 8711 | { |
1903d50c PZ |
8712 | /* |
8713 | * Do not destroy the 'original' grouping; because of the context | |
8714 | * switch optimization the original events could've ended up in a | |
8715 | * random child task. | |
8716 | * | |
8717 | * If we were to destroy the original group, all group related | |
8718 | * operations would cease to function properly after this random | |
8719 | * child dies. | |
8720 | * | |
8721 | * Do destroy all inherited groups, we don't care about those | |
8722 | * and being thorough is better. | |
8723 | */ | |
8724 | perf_remove_from_context(child_event, !!child_event->parent); | |
0cc0c027 | 8725 | |
9b51f66d | 8726 | /* |
38b435b1 | 8727 | * It can happen that the parent exits first, and has events |
9b51f66d | 8728 | * that are still around due to the child reference. These |
38b435b1 | 8729 | * events need to be zapped. |
9b51f66d | 8730 | */ |
38b435b1 | 8731 | if (child_event->parent) { |
cdd6c482 IM |
8732 | sync_child_event(child_event, child); |
8733 | free_event(child_event); | |
179033b3 JO |
8734 | } else { |
8735 | child_event->state = PERF_EVENT_STATE_EXIT; | |
8736 | perf_event_wakeup(child_event); | |
4bcf349a | 8737 | } |
9b51f66d IM |
8738 | } |
8739 | ||
8dc85d54 | 8740 | static void perf_event_exit_task_context(struct task_struct *child, int ctxn) |
9b51f66d | 8741 | { |
ebf905fc | 8742 | struct perf_event *child_event, *next; |
211de6eb | 8743 | struct perf_event_context *child_ctx, *clone_ctx = NULL; |
a63eaf34 | 8744 | unsigned long flags; |
9b51f66d | 8745 | |
4e93ad60 | 8746 | if (likely(!child->perf_event_ctxp[ctxn])) |
9b51f66d IM |
8747 | return; |
8748 | ||
a63eaf34 | 8749 | local_irq_save(flags); |
ad3a37de PM |
8750 | /* |
8751 | * We can't reschedule here because interrupts are disabled, | |
8752 | * and either child is current or it is a task that can't be | |
8753 | * scheduled, so we are now safe from rescheduling changing | |
8754 | * our context. | |
8755 | */ | |
806839b2 | 8756 | child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]); |
c93f7669 PM |
8757 | |
8758 | /* | |
8759 | * Take the context lock here so that if find_get_context is | |
cdd6c482 | 8760 | * reading child->perf_event_ctxp, we wait until it has |
c93f7669 PM |
8761 | * incremented the context's refcount before we do put_ctx below. |
8762 | */ | |
e625cce1 | 8763 | raw_spin_lock(&child_ctx->lock); |
04dc2dbb | 8764 | task_ctx_sched_out(child_ctx); |
8dc85d54 | 8765 | child->perf_event_ctxp[ctxn] = NULL; |
4a1c0f26 | 8766 | |
71a851b4 PZ |
8767 | /* |
8768 | * If this context is a clone; unclone it so it can't get | |
8769 | * swapped to another process while we're removing all | |
cdd6c482 | 8770 | * the events from it. |
71a851b4 | 8771 | */ |
211de6eb | 8772 | clone_ctx = unclone_ctx(child_ctx); |
5e942bb3 | 8773 | update_context_time(child_ctx); |
e625cce1 | 8774 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
9f498cc5 | 8775 | |
211de6eb PZ |
8776 | if (clone_ctx) |
8777 | put_ctx(clone_ctx); | |
4a1c0f26 | 8778 | |
9f498cc5 | 8779 | /* |
cdd6c482 IM |
8780 | * Report the task dead after unscheduling the events so that we |
8781 | * won't get any samples after PERF_RECORD_EXIT. We can however still | |
8782 | * get a few PERF_RECORD_READ events. | |
9f498cc5 | 8783 | */ |
cdd6c482 | 8784 | perf_event_task(child, child_ctx, 0); |
a63eaf34 | 8785 | |
66fff224 PZ |
8786 | /* |
8787 | * We can recurse on the same lock type through: | |
8788 | * | |
cdd6c482 IM |
8789 | * __perf_event_exit_task() |
8790 | * sync_child_event() | |
a6fa941d AV |
8791 | * put_event() |
8792 | * mutex_lock(&ctx->mutex) | |
66fff224 PZ |
8793 | * |
8794 | * But since its the parent context it won't be the same instance. | |
8795 | */ | |
a0507c84 | 8796 | mutex_lock(&child_ctx->mutex); |
a63eaf34 | 8797 | |
ebf905fc | 8798 | list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) |
cdd6c482 | 8799 | __perf_event_exit_task(child_event, child_ctx, child); |
8bc20959 | 8800 | |
a63eaf34 PM |
8801 | mutex_unlock(&child_ctx->mutex); |
8802 | ||
8803 | put_ctx(child_ctx); | |
9b51f66d IM |
8804 | } |
8805 | ||
8dc85d54 PZ |
8806 | /* |
8807 | * When a child task exits, feed back event values to parent events. | |
8808 | */ | |
8809 | void perf_event_exit_task(struct task_struct *child) | |
8810 | { | |
8882135b | 8811 | struct perf_event *event, *tmp; |
8dc85d54 PZ |
8812 | int ctxn; |
8813 | ||
8882135b PZ |
8814 | mutex_lock(&child->perf_event_mutex); |
8815 | list_for_each_entry_safe(event, tmp, &child->perf_event_list, | |
8816 | owner_entry) { | |
8817 | list_del_init(&event->owner_entry); | |
8818 | ||
8819 | /* | |
8820 | * Ensure the list deletion is visible before we clear | |
8821 | * the owner, closes a race against perf_release() where | |
8822 | * we need to serialize on the owner->perf_event_mutex. | |
8823 | */ | |
8824 | smp_wmb(); | |
8825 | event->owner = NULL; | |
8826 | } | |
8827 | mutex_unlock(&child->perf_event_mutex); | |
8828 | ||
8dc85d54 PZ |
8829 | for_each_task_context_nr(ctxn) |
8830 | perf_event_exit_task_context(child, ctxn); | |
4e93ad60 JO |
8831 | |
8832 | /* | |
8833 | * The perf_event_exit_task_context calls perf_event_task | |
8834 | * with child's task_ctx, which generates EXIT events for | |
8835 | * child contexts and sets child->perf_event_ctxp[] to NULL. | |
8836 | * At this point we need to send EXIT events to cpu contexts. | |
8837 | */ | |
8838 | perf_event_task(child, NULL, 0); | |
8dc85d54 PZ |
8839 | } |
8840 | ||
889ff015 FW |
8841 | static void perf_free_event(struct perf_event *event, |
8842 | struct perf_event_context *ctx) | |
8843 | { | |
8844 | struct perf_event *parent = event->parent; | |
8845 | ||
8846 | if (WARN_ON_ONCE(!parent)) | |
8847 | return; | |
8848 | ||
8849 | mutex_lock(&parent->child_mutex); | |
8850 | list_del_init(&event->child_list); | |
8851 | mutex_unlock(&parent->child_mutex); | |
8852 | ||
a6fa941d | 8853 | put_event(parent); |
889ff015 | 8854 | |
652884fe | 8855 | raw_spin_lock_irq(&ctx->lock); |
8a49542c | 8856 | perf_group_detach(event); |
889ff015 | 8857 | list_del_event(event, ctx); |
652884fe | 8858 | raw_spin_unlock_irq(&ctx->lock); |
889ff015 FW |
8859 | free_event(event); |
8860 | } | |
8861 | ||
bbbee908 | 8862 | /* |
652884fe | 8863 | * Free an unexposed, unused context as created by inheritance by |
8dc85d54 | 8864 | * perf_event_init_task below, used by fork() in case of fail. |
652884fe PZ |
8865 | * |
8866 | * Not all locks are strictly required, but take them anyway to be nice and | |
8867 | * help out with the lockdep assertions. | |
bbbee908 | 8868 | */ |
cdd6c482 | 8869 | void perf_event_free_task(struct task_struct *task) |
bbbee908 | 8870 | { |
8dc85d54 | 8871 | struct perf_event_context *ctx; |
cdd6c482 | 8872 | struct perf_event *event, *tmp; |
8dc85d54 | 8873 | int ctxn; |
bbbee908 | 8874 | |
8dc85d54 PZ |
8875 | for_each_task_context_nr(ctxn) { |
8876 | ctx = task->perf_event_ctxp[ctxn]; | |
8877 | if (!ctx) | |
8878 | continue; | |
bbbee908 | 8879 | |
8dc85d54 | 8880 | mutex_lock(&ctx->mutex); |
bbbee908 | 8881 | again: |
8dc85d54 PZ |
8882 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, |
8883 | group_entry) | |
8884 | perf_free_event(event, ctx); | |
bbbee908 | 8885 | |
8dc85d54 PZ |
8886 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
8887 | group_entry) | |
8888 | perf_free_event(event, ctx); | |
bbbee908 | 8889 | |
8dc85d54 PZ |
8890 | if (!list_empty(&ctx->pinned_groups) || |
8891 | !list_empty(&ctx->flexible_groups)) | |
8892 | goto again; | |
bbbee908 | 8893 | |
8dc85d54 | 8894 | mutex_unlock(&ctx->mutex); |
bbbee908 | 8895 | |
8dc85d54 PZ |
8896 | put_ctx(ctx); |
8897 | } | |
889ff015 FW |
8898 | } |
8899 | ||
4e231c79 PZ |
8900 | void perf_event_delayed_put(struct task_struct *task) |
8901 | { | |
8902 | int ctxn; | |
8903 | ||
8904 | for_each_task_context_nr(ctxn) | |
8905 | WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); | |
8906 | } | |
8907 | ||
ffe8690c KX |
8908 | struct perf_event *perf_event_get(unsigned int fd) |
8909 | { | |
8910 | int err; | |
8911 | struct fd f; | |
8912 | struct perf_event *event; | |
8913 | ||
8914 | err = perf_fget_light(fd, &f); | |
8915 | if (err) | |
8916 | return ERR_PTR(err); | |
8917 | ||
8918 | event = f.file->private_data; | |
8919 | atomic_long_inc(&event->refcount); | |
8920 | fdput(f); | |
8921 | ||
8922 | return event; | |
8923 | } | |
8924 | ||
8925 | const struct perf_event_attr *perf_event_attrs(struct perf_event *event) | |
8926 | { | |
8927 | if (!event) | |
8928 | return ERR_PTR(-EINVAL); | |
8929 | ||
8930 | return &event->attr; | |
8931 | } | |
8932 | ||
97dee4f3 PZ |
8933 | /* |
8934 | * inherit a event from parent task to child task: | |
8935 | */ | |
8936 | static struct perf_event * | |
8937 | inherit_event(struct perf_event *parent_event, | |
8938 | struct task_struct *parent, | |
8939 | struct perf_event_context *parent_ctx, | |
8940 | struct task_struct *child, | |
8941 | struct perf_event *group_leader, | |
8942 | struct perf_event_context *child_ctx) | |
8943 | { | |
1929def9 | 8944 | enum perf_event_active_state parent_state = parent_event->state; |
97dee4f3 | 8945 | struct perf_event *child_event; |
cee010ec | 8946 | unsigned long flags; |
97dee4f3 PZ |
8947 | |
8948 | /* | |
8949 | * Instead of creating recursive hierarchies of events, | |
8950 | * we link inherited events back to the original parent, | |
8951 | * which has a filp for sure, which we use as the reference | |
8952 | * count: | |
8953 | */ | |
8954 | if (parent_event->parent) | |
8955 | parent_event = parent_event->parent; | |
8956 | ||
8957 | child_event = perf_event_alloc(&parent_event->attr, | |
8958 | parent_event->cpu, | |
d580ff86 | 8959 | child, |
97dee4f3 | 8960 | group_leader, parent_event, |
79dff51e | 8961 | NULL, NULL, -1); |
97dee4f3 PZ |
8962 | if (IS_ERR(child_event)) |
8963 | return child_event; | |
a6fa941d | 8964 | |
fadfe7be JO |
8965 | if (is_orphaned_event(parent_event) || |
8966 | !atomic_long_inc_not_zero(&parent_event->refcount)) { | |
a6fa941d AV |
8967 | free_event(child_event); |
8968 | return NULL; | |
8969 | } | |
8970 | ||
97dee4f3 PZ |
8971 | get_ctx(child_ctx); |
8972 | ||
8973 | /* | |
8974 | * Make the child state follow the state of the parent event, | |
8975 | * not its attr.disabled bit. We hold the parent's mutex, | |
8976 | * so we won't race with perf_event_{en, dis}able_family. | |
8977 | */ | |
1929def9 | 8978 | if (parent_state >= PERF_EVENT_STATE_INACTIVE) |
97dee4f3 PZ |
8979 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
8980 | else | |
8981 | child_event->state = PERF_EVENT_STATE_OFF; | |
8982 | ||
8983 | if (parent_event->attr.freq) { | |
8984 | u64 sample_period = parent_event->hw.sample_period; | |
8985 | struct hw_perf_event *hwc = &child_event->hw; | |
8986 | ||
8987 | hwc->sample_period = sample_period; | |
8988 | hwc->last_period = sample_period; | |
8989 | ||
8990 | local64_set(&hwc->period_left, sample_period); | |
8991 | } | |
8992 | ||
8993 | child_event->ctx = child_ctx; | |
8994 | child_event->overflow_handler = parent_event->overflow_handler; | |
4dc0da86 AK |
8995 | child_event->overflow_handler_context |
8996 | = parent_event->overflow_handler_context; | |
97dee4f3 | 8997 | |
614b6780 TG |
8998 | /* |
8999 | * Precalculate sample_data sizes | |
9000 | */ | |
9001 | perf_event__header_size(child_event); | |
6844c09d | 9002 | perf_event__id_header_size(child_event); |
614b6780 | 9003 | |
97dee4f3 PZ |
9004 | /* |
9005 | * Link it up in the child's context: | |
9006 | */ | |
cee010ec | 9007 | raw_spin_lock_irqsave(&child_ctx->lock, flags); |
97dee4f3 | 9008 | add_event_to_ctx(child_event, child_ctx); |
cee010ec | 9009 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
97dee4f3 | 9010 | |
97dee4f3 PZ |
9011 | /* |
9012 | * Link this into the parent event's child list | |
9013 | */ | |
9014 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); | |
9015 | mutex_lock(&parent_event->child_mutex); | |
9016 | list_add_tail(&child_event->child_list, &parent_event->child_list); | |
9017 | mutex_unlock(&parent_event->child_mutex); | |
9018 | ||
9019 | return child_event; | |
9020 | } | |
9021 | ||
9022 | static int inherit_group(struct perf_event *parent_event, | |
9023 | struct task_struct *parent, | |
9024 | struct perf_event_context *parent_ctx, | |
9025 | struct task_struct *child, | |
9026 | struct perf_event_context *child_ctx) | |
9027 | { | |
9028 | struct perf_event *leader; | |
9029 | struct perf_event *sub; | |
9030 | struct perf_event *child_ctr; | |
9031 | ||
9032 | leader = inherit_event(parent_event, parent, parent_ctx, | |
9033 | child, NULL, child_ctx); | |
9034 | if (IS_ERR(leader)) | |
9035 | return PTR_ERR(leader); | |
9036 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { | |
9037 | child_ctr = inherit_event(sub, parent, parent_ctx, | |
9038 | child, leader, child_ctx); | |
9039 | if (IS_ERR(child_ctr)) | |
9040 | return PTR_ERR(child_ctr); | |
9041 | } | |
9042 | return 0; | |
889ff015 FW |
9043 | } |
9044 | ||
9045 | static int | |
9046 | inherit_task_group(struct perf_event *event, struct task_struct *parent, | |
9047 | struct perf_event_context *parent_ctx, | |
8dc85d54 | 9048 | struct task_struct *child, int ctxn, |
889ff015 FW |
9049 | int *inherited_all) |
9050 | { | |
9051 | int ret; | |
8dc85d54 | 9052 | struct perf_event_context *child_ctx; |
889ff015 FW |
9053 | |
9054 | if (!event->attr.inherit) { | |
9055 | *inherited_all = 0; | |
9056 | return 0; | |
bbbee908 PZ |
9057 | } |
9058 | ||
fe4b04fa | 9059 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 FW |
9060 | if (!child_ctx) { |
9061 | /* | |
9062 | * This is executed from the parent task context, so | |
9063 | * inherit events that have been marked for cloning. | |
9064 | * First allocate and initialize a context for the | |
9065 | * child. | |
9066 | */ | |
bbbee908 | 9067 | |
734df5ab | 9068 | child_ctx = alloc_perf_context(parent_ctx->pmu, child); |
889ff015 FW |
9069 | if (!child_ctx) |
9070 | return -ENOMEM; | |
bbbee908 | 9071 | |
8dc85d54 | 9072 | child->perf_event_ctxp[ctxn] = child_ctx; |
889ff015 FW |
9073 | } |
9074 | ||
9075 | ret = inherit_group(event, parent, parent_ctx, | |
9076 | child, child_ctx); | |
9077 | ||
9078 | if (ret) | |
9079 | *inherited_all = 0; | |
9080 | ||
9081 | return ret; | |
bbbee908 PZ |
9082 | } |
9083 | ||
9b51f66d | 9084 | /* |
cdd6c482 | 9085 | * Initialize the perf_event context in task_struct |
9b51f66d | 9086 | */ |
985c8dcb | 9087 | static int perf_event_init_context(struct task_struct *child, int ctxn) |
9b51f66d | 9088 | { |
889ff015 | 9089 | struct perf_event_context *child_ctx, *parent_ctx; |
cdd6c482 IM |
9090 | struct perf_event_context *cloned_ctx; |
9091 | struct perf_event *event; | |
9b51f66d | 9092 | struct task_struct *parent = current; |
564c2b21 | 9093 | int inherited_all = 1; |
dddd3379 | 9094 | unsigned long flags; |
6ab423e0 | 9095 | int ret = 0; |
9b51f66d | 9096 | |
8dc85d54 | 9097 | if (likely(!parent->perf_event_ctxp[ctxn])) |
6ab423e0 PZ |
9098 | return 0; |
9099 | ||
ad3a37de | 9100 | /* |
25346b93 PM |
9101 | * If the parent's context is a clone, pin it so it won't get |
9102 | * swapped under us. | |
ad3a37de | 9103 | */ |
8dc85d54 | 9104 | parent_ctx = perf_pin_task_context(parent, ctxn); |
ffb4ef21 PZ |
9105 | if (!parent_ctx) |
9106 | return 0; | |
25346b93 | 9107 | |
ad3a37de PM |
9108 | /* |
9109 | * No need to check if parent_ctx != NULL here; since we saw | |
9110 | * it non-NULL earlier, the only reason for it to become NULL | |
9111 | * is if we exit, and since we're currently in the middle of | |
9112 | * a fork we can't be exiting at the same time. | |
9113 | */ | |
ad3a37de | 9114 | |
9b51f66d IM |
9115 | /* |
9116 | * Lock the parent list. No need to lock the child - not PID | |
9117 | * hashed yet and not running, so nobody can access it. | |
9118 | */ | |
d859e29f | 9119 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
9120 | |
9121 | /* | |
9122 | * We dont have to disable NMIs - we are only looking at | |
9123 | * the list, not manipulating it: | |
9124 | */ | |
889ff015 | 9125 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
8dc85d54 PZ |
9126 | ret = inherit_task_group(event, parent, parent_ctx, |
9127 | child, ctxn, &inherited_all); | |
889ff015 FW |
9128 | if (ret) |
9129 | break; | |
9130 | } | |
b93f7978 | 9131 | |
dddd3379 TG |
9132 | /* |
9133 | * We can't hold ctx->lock when iterating the ->flexible_group list due | |
9134 | * to allocations, but we need to prevent rotation because | |
9135 | * rotate_ctx() will change the list from interrupt context. | |
9136 | */ | |
9137 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); | |
9138 | parent_ctx->rotate_disable = 1; | |
9139 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); | |
9140 | ||
889ff015 | 9141 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
8dc85d54 PZ |
9142 | ret = inherit_task_group(event, parent, parent_ctx, |
9143 | child, ctxn, &inherited_all); | |
889ff015 | 9144 | if (ret) |
9b51f66d | 9145 | break; |
564c2b21 PM |
9146 | } |
9147 | ||
dddd3379 TG |
9148 | raw_spin_lock_irqsave(&parent_ctx->lock, flags); |
9149 | parent_ctx->rotate_disable = 0; | |
dddd3379 | 9150 | |
8dc85d54 | 9151 | child_ctx = child->perf_event_ctxp[ctxn]; |
889ff015 | 9152 | |
05cbaa28 | 9153 | if (child_ctx && inherited_all) { |
564c2b21 PM |
9154 | /* |
9155 | * Mark the child context as a clone of the parent | |
9156 | * context, or of whatever the parent is a clone of. | |
c5ed5145 PZ |
9157 | * |
9158 | * Note that if the parent is a clone, the holding of | |
9159 | * parent_ctx->lock avoids it from being uncloned. | |
564c2b21 | 9160 | */ |
c5ed5145 | 9161 | cloned_ctx = parent_ctx->parent_ctx; |
ad3a37de PM |
9162 | if (cloned_ctx) { |
9163 | child_ctx->parent_ctx = cloned_ctx; | |
25346b93 | 9164 | child_ctx->parent_gen = parent_ctx->parent_gen; |
564c2b21 PM |
9165 | } else { |
9166 | child_ctx->parent_ctx = parent_ctx; | |
9167 | child_ctx->parent_gen = parent_ctx->generation; | |
9168 | } | |
9169 | get_ctx(child_ctx->parent_ctx); | |
9b51f66d IM |
9170 | } |
9171 | ||
c5ed5145 | 9172 | raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); |
d859e29f | 9173 | mutex_unlock(&parent_ctx->mutex); |
6ab423e0 | 9174 | |
25346b93 | 9175 | perf_unpin_context(parent_ctx); |
fe4b04fa | 9176 | put_ctx(parent_ctx); |
ad3a37de | 9177 | |
6ab423e0 | 9178 | return ret; |
9b51f66d IM |
9179 | } |
9180 | ||
8dc85d54 PZ |
9181 | /* |
9182 | * Initialize the perf_event context in task_struct | |
9183 | */ | |
9184 | int perf_event_init_task(struct task_struct *child) | |
9185 | { | |
9186 | int ctxn, ret; | |
9187 | ||
8550d7cb ON |
9188 | memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); |
9189 | mutex_init(&child->perf_event_mutex); | |
9190 | INIT_LIST_HEAD(&child->perf_event_list); | |
9191 | ||
8dc85d54 PZ |
9192 | for_each_task_context_nr(ctxn) { |
9193 | ret = perf_event_init_context(child, ctxn); | |
6c72e350 PZ |
9194 | if (ret) { |
9195 | perf_event_free_task(child); | |
8dc85d54 | 9196 | return ret; |
6c72e350 | 9197 | } |
8dc85d54 PZ |
9198 | } |
9199 | ||
9200 | return 0; | |
9201 | } | |
9202 | ||
220b140b PM |
9203 | static void __init perf_event_init_all_cpus(void) |
9204 | { | |
b28ab83c | 9205 | struct swevent_htable *swhash; |
220b140b | 9206 | int cpu; |
220b140b PM |
9207 | |
9208 | for_each_possible_cpu(cpu) { | |
b28ab83c PZ |
9209 | swhash = &per_cpu(swevent_htable, cpu); |
9210 | mutex_init(&swhash->hlist_mutex); | |
2fde4f94 | 9211 | INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu)); |
220b140b PM |
9212 | } |
9213 | } | |
9214 | ||
0db0628d | 9215 | static void perf_event_init_cpu(int cpu) |
0793a61d | 9216 | { |
108b02cf | 9217 | struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); |
0793a61d | 9218 | |
b28ab83c | 9219 | mutex_lock(&swhash->hlist_mutex); |
4536e4d1 | 9220 | if (swhash->hlist_refcount > 0) { |
76e1d904 FW |
9221 | struct swevent_hlist *hlist; |
9222 | ||
b28ab83c PZ |
9223 | hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); |
9224 | WARN_ON(!hlist); | |
9225 | rcu_assign_pointer(swhash->swevent_hlist, hlist); | |
76e1d904 | 9226 | } |
b28ab83c | 9227 | mutex_unlock(&swhash->hlist_mutex); |
0793a61d TG |
9228 | } |
9229 | ||
2965faa5 | 9230 | #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE |
108b02cf | 9231 | static void __perf_event_exit_context(void *__info) |
0793a61d | 9232 | { |
226424ee | 9233 | struct remove_event re = { .detach_group = true }; |
108b02cf | 9234 | struct perf_event_context *ctx = __info; |
0793a61d | 9235 | |
e3703f8c | 9236 | rcu_read_lock(); |
46ce0fe9 PZ |
9237 | list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) |
9238 | __perf_remove_from_context(&re); | |
e3703f8c | 9239 | rcu_read_unlock(); |
0793a61d | 9240 | } |
108b02cf PZ |
9241 | |
9242 | static void perf_event_exit_cpu_context(int cpu) | |
9243 | { | |
9244 | struct perf_event_context *ctx; | |
9245 | struct pmu *pmu; | |
9246 | int idx; | |
9247 | ||
9248 | idx = srcu_read_lock(&pmus_srcu); | |
9249 | list_for_each_entry_rcu(pmu, &pmus, entry) { | |
917bdd1c | 9250 | ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx; |
108b02cf PZ |
9251 | |
9252 | mutex_lock(&ctx->mutex); | |
9253 | smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); | |
9254 | mutex_unlock(&ctx->mutex); | |
9255 | } | |
9256 | srcu_read_unlock(&pmus_srcu, idx); | |
108b02cf PZ |
9257 | } |
9258 | ||
cdd6c482 | 9259 | static void perf_event_exit_cpu(int cpu) |
0793a61d | 9260 | { |
e3703f8c | 9261 | perf_event_exit_cpu_context(cpu); |
0793a61d TG |
9262 | } |
9263 | #else | |
cdd6c482 | 9264 | static inline void perf_event_exit_cpu(int cpu) { } |
0793a61d TG |
9265 | #endif |
9266 | ||
c277443c PZ |
9267 | static int |
9268 | perf_reboot(struct notifier_block *notifier, unsigned long val, void *v) | |
9269 | { | |
9270 | int cpu; | |
9271 | ||
9272 | for_each_online_cpu(cpu) | |
9273 | perf_event_exit_cpu(cpu); | |
9274 | ||
9275 | return NOTIFY_OK; | |
9276 | } | |
9277 | ||
9278 | /* | |
9279 | * Run the perf reboot notifier at the very last possible moment so that | |
9280 | * the generic watchdog code runs as long as possible. | |
9281 | */ | |
9282 | static struct notifier_block perf_reboot_notifier = { | |
9283 | .notifier_call = perf_reboot, | |
9284 | .priority = INT_MIN, | |
9285 | }; | |
9286 | ||
0db0628d | 9287 | static int |
0793a61d TG |
9288 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
9289 | { | |
9290 | unsigned int cpu = (long)hcpu; | |
9291 | ||
4536e4d1 | 9292 | switch (action & ~CPU_TASKS_FROZEN) { |
0793a61d TG |
9293 | |
9294 | case CPU_UP_PREPARE: | |
5e11637e | 9295 | case CPU_DOWN_FAILED: |
cdd6c482 | 9296 | perf_event_init_cpu(cpu); |
0793a61d TG |
9297 | break; |
9298 | ||
5e11637e | 9299 | case CPU_UP_CANCELED: |
0793a61d | 9300 | case CPU_DOWN_PREPARE: |
cdd6c482 | 9301 | perf_event_exit_cpu(cpu); |
0793a61d | 9302 | break; |
0793a61d TG |
9303 | default: |
9304 | break; | |
9305 | } | |
9306 | ||
9307 | return NOTIFY_OK; | |
9308 | } | |
9309 | ||
cdd6c482 | 9310 | void __init perf_event_init(void) |
0793a61d | 9311 | { |
3c502e7a JW |
9312 | int ret; |
9313 | ||
2e80a82a PZ |
9314 | idr_init(&pmu_idr); |
9315 | ||
220b140b | 9316 | perf_event_init_all_cpus(); |
b0a873eb | 9317 | init_srcu_struct(&pmus_srcu); |
2e80a82a PZ |
9318 | perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); |
9319 | perf_pmu_register(&perf_cpu_clock, NULL, -1); | |
9320 | perf_pmu_register(&perf_task_clock, NULL, -1); | |
b0a873eb PZ |
9321 | perf_tp_register(); |
9322 | perf_cpu_notifier(perf_cpu_notify); | |
c277443c | 9323 | register_reboot_notifier(&perf_reboot_notifier); |
3c502e7a JW |
9324 | |
9325 | ret = init_hw_breakpoint(); | |
9326 | WARN(ret, "hw_breakpoint initialization failed with: %d", ret); | |
b2029520 GN |
9327 | |
9328 | /* do not patch jump label more than once per second */ | |
9329 | jump_label_rate_limit(&perf_sched_events, HZ); | |
b01c3a00 JO |
9330 | |
9331 | /* | |
9332 | * Build time assertion that we keep the data_head at the intended | |
9333 | * location. IOW, validation we got the __reserved[] size right. | |
9334 | */ | |
9335 | BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) | |
9336 | != 1024); | |
0793a61d | 9337 | } |
abe43400 | 9338 | |
fd979c01 CS |
9339 | ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, |
9340 | char *page) | |
9341 | { | |
9342 | struct perf_pmu_events_attr *pmu_attr = | |
9343 | container_of(attr, struct perf_pmu_events_attr, attr); | |
9344 | ||
9345 | if (pmu_attr->event_str) | |
9346 | return sprintf(page, "%s\n", pmu_attr->event_str); | |
9347 | ||
9348 | return 0; | |
9349 | } | |
9350 | ||
abe43400 PZ |
9351 | static int __init perf_event_sysfs_init(void) |
9352 | { | |
9353 | struct pmu *pmu; | |
9354 | int ret; | |
9355 | ||
9356 | mutex_lock(&pmus_lock); | |
9357 | ||
9358 | ret = bus_register(&pmu_bus); | |
9359 | if (ret) | |
9360 | goto unlock; | |
9361 | ||
9362 | list_for_each_entry(pmu, &pmus, entry) { | |
9363 | if (!pmu->name || pmu->type < 0) | |
9364 | continue; | |
9365 | ||
9366 | ret = pmu_dev_alloc(pmu); | |
9367 | WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); | |
9368 | } | |
9369 | pmu_bus_running = 1; | |
9370 | ret = 0; | |
9371 | ||
9372 | unlock: | |
9373 | mutex_unlock(&pmus_lock); | |
9374 | ||
9375 | return ret; | |
9376 | } | |
9377 | device_initcall(perf_event_sysfs_init); | |
e5d1367f SE |
9378 | |
9379 | #ifdef CONFIG_CGROUP_PERF | |
eb95419b TH |
9380 | static struct cgroup_subsys_state * |
9381 | perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
e5d1367f SE |
9382 | { |
9383 | struct perf_cgroup *jc; | |
e5d1367f | 9384 | |
1b15d055 | 9385 | jc = kzalloc(sizeof(*jc), GFP_KERNEL); |
e5d1367f SE |
9386 | if (!jc) |
9387 | return ERR_PTR(-ENOMEM); | |
9388 | ||
e5d1367f SE |
9389 | jc->info = alloc_percpu(struct perf_cgroup_info); |
9390 | if (!jc->info) { | |
9391 | kfree(jc); | |
9392 | return ERR_PTR(-ENOMEM); | |
9393 | } | |
9394 | ||
e5d1367f SE |
9395 | return &jc->css; |
9396 | } | |
9397 | ||
eb95419b | 9398 | static void perf_cgroup_css_free(struct cgroup_subsys_state *css) |
e5d1367f | 9399 | { |
eb95419b TH |
9400 | struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css); |
9401 | ||
e5d1367f SE |
9402 | free_percpu(jc->info); |
9403 | kfree(jc); | |
9404 | } | |
9405 | ||
9406 | static int __perf_cgroup_move(void *info) | |
9407 | { | |
9408 | struct task_struct *task = info; | |
ddaaf4e2 | 9409 | rcu_read_lock(); |
e5d1367f | 9410 | perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN); |
ddaaf4e2 | 9411 | rcu_read_unlock(); |
e5d1367f SE |
9412 | return 0; |
9413 | } | |
9414 | ||
1f7dd3e5 | 9415 | static void perf_cgroup_attach(struct cgroup_taskset *tset) |
e5d1367f | 9416 | { |
bb9d97b6 | 9417 | struct task_struct *task; |
1f7dd3e5 | 9418 | struct cgroup_subsys_state *css; |
bb9d97b6 | 9419 | |
1f7dd3e5 | 9420 | cgroup_taskset_for_each(task, css, tset) |
bb9d97b6 | 9421 | task_function_call(task, __perf_cgroup_move, task); |
e5d1367f SE |
9422 | } |
9423 | ||
073219e9 | 9424 | struct cgroup_subsys perf_event_cgrp_subsys = { |
92fb9748 TH |
9425 | .css_alloc = perf_cgroup_css_alloc, |
9426 | .css_free = perf_cgroup_css_free, | |
bb9d97b6 | 9427 | .attach = perf_cgroup_attach, |
e5d1367f SE |
9428 | }; |
9429 | #endif /* CONFIG_CGROUP_PERF */ |