xref: /linux/tools/perf/util/evlist.c (revision 31354121bf03dac6498a4236928a38490745d601)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
4  *
5  * Parts came from builtin-{top,stat,record}.c, see those files for further
6  * copyright notes.
7  */
8 #include <api/fs/fs.h>
9 #include <errno.h>
10 #include <inttypes.h>
11 #include <poll.h>
12 #include "cpumap.h"
13 #include "util/mmap.h"
14 #include "thread_map.h"
15 #include "target.h"
16 #include "evlist.h"
17 #include "evsel.h"
18 #include "record.h"
19 #include "debug.h"
20 #include "units.h"
21 #include "bpf_counter.h"
22 #include <internal/lib.h> // page_size
23 #include "affinity.h"
24 #include "../perf.h"
25 #include "asm/bug.h"
26 #include "bpf-event.h"
27 #include "util/string2.h"
28 #include "util/perf_api_probe.h"
29 #include "util/evsel_fprintf.h"
30 #include "util/evlist-hybrid.h"
31 #include "util/pmu.h"
32 #include <signal.h>
33 #include <unistd.h>
34 #include <sched.h>
35 #include <stdlib.h>
36 
37 #include "parse-events.h"
38 #include <subcmd/parse-options.h>
39 
40 #include <fcntl.h>
41 #include <sys/ioctl.h>
42 #include <sys/mman.h>
43 #include <sys/prctl.h>
44 #include <sys/timerfd.h>
45 
46 #include <linux/bitops.h>
47 #include <linux/hash.h>
48 #include <linux/log2.h>
49 #include <linux/err.h>
50 #include <linux/string.h>
51 #include <linux/time64.h>
52 #include <linux/zalloc.h>
53 #include <perf/evlist.h>
54 #include <perf/evsel.h>
55 #include <perf/cpumap.h>
56 #include <perf/mmap.h>
57 
58 #include <internal/xyarray.h>
59 
60 #ifdef LACKS_SIGQUEUE_PROTOTYPE
61 int sigqueue(pid_t pid, int sig, const union sigval value);
62 #endif
63 
64 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
65 #define SID(e, x, y) xyarray__entry(e->core.sample_id, x, y)
66 
67 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
68 		  struct perf_thread_map *threads)
69 {
70 	perf_evlist__init(&evlist->core);
71 	perf_evlist__set_maps(&evlist->core, cpus, threads);
72 	evlist->workload.pid = -1;
73 	evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
74 	evlist->ctl_fd.fd = -1;
75 	evlist->ctl_fd.ack = -1;
76 	evlist->ctl_fd.pos = -1;
77 }
78 
79 struct evlist *evlist__new(void)
80 {
81 	struct evlist *evlist = zalloc(sizeof(*evlist));
82 
83 	if (evlist != NULL)
84 		evlist__init(evlist, NULL, NULL);
85 
86 	return evlist;
87 }
88 
89 struct evlist *evlist__new_default(void)
90 {
91 	struct evlist *evlist = evlist__new();
92 
93 	if (evlist && evlist__add_default(evlist)) {
94 		evlist__delete(evlist);
95 		evlist = NULL;
96 	}
97 
98 	return evlist;
99 }
100 
101 struct evlist *evlist__new_dummy(void)
102 {
103 	struct evlist *evlist = evlist__new();
104 
105 	if (evlist && evlist__add_dummy(evlist)) {
106 		evlist__delete(evlist);
107 		evlist = NULL;
108 	}
109 
110 	return evlist;
111 }
112 
113 /**
114  * evlist__set_id_pos - set the positions of event ids.
115  * @evlist: selected event list
116  *
117  * Events with compatible sample types all have the same id_pos
118  * and is_pos.  For convenience, put a copy on evlist.
119  */
120 void evlist__set_id_pos(struct evlist *evlist)
121 {
122 	struct evsel *first = evlist__first(evlist);
123 
124 	evlist->id_pos = first->id_pos;
125 	evlist->is_pos = first->is_pos;
126 }
127 
128 static void evlist__update_id_pos(struct evlist *evlist)
129 {
130 	struct evsel *evsel;
131 
132 	evlist__for_each_entry(evlist, evsel)
133 		evsel__calc_id_pos(evsel);
134 
135 	evlist__set_id_pos(evlist);
136 }
137 
138 static void evlist__purge(struct evlist *evlist)
139 {
140 	struct evsel *pos, *n;
141 
142 	evlist__for_each_entry_safe(evlist, n, pos) {
143 		list_del_init(&pos->core.node);
144 		pos->evlist = NULL;
145 		evsel__delete(pos);
146 	}
147 
148 	evlist->core.nr_entries = 0;
149 }
150 
151 void evlist__exit(struct evlist *evlist)
152 {
153 	event_enable_timer__exit(&evlist->eet);
154 	zfree(&evlist->mmap);
155 	zfree(&evlist->overwrite_mmap);
156 	perf_evlist__exit(&evlist->core);
157 }
158 
159 void evlist__delete(struct evlist *evlist)
160 {
161 	if (evlist == NULL)
162 		return;
163 
164 	evlist__munmap(evlist);
165 	evlist__close(evlist);
166 	evlist__purge(evlist);
167 	evlist__exit(evlist);
168 	free(evlist);
169 }
170 
171 void evlist__add(struct evlist *evlist, struct evsel *entry)
172 {
173 	perf_evlist__add(&evlist->core, &entry->core);
174 	entry->evlist = evlist;
175 	entry->tracking = !entry->core.idx;
176 
177 	if (evlist->core.nr_entries == 1)
178 		evlist__set_id_pos(evlist);
179 }
180 
181 void evlist__remove(struct evlist *evlist, struct evsel *evsel)
182 {
183 	evsel->evlist = NULL;
184 	perf_evlist__remove(&evlist->core, &evsel->core);
185 }
186 
187 void evlist__splice_list_tail(struct evlist *evlist, struct list_head *list)
188 {
189 	while (!list_empty(list)) {
190 		struct evsel *evsel, *temp, *leader = NULL;
191 
192 		__evlist__for_each_entry_safe(list, temp, evsel) {
193 			list_del_init(&evsel->core.node);
194 			evlist__add(evlist, evsel);
195 			leader = evsel;
196 			break;
197 		}
198 
199 		__evlist__for_each_entry_safe(list, temp, evsel) {
200 			if (evsel__has_leader(evsel, leader)) {
201 				list_del_init(&evsel->core.node);
202 				evlist__add(evlist, evsel);
203 			}
204 		}
205 	}
206 }
207 
208 int __evlist__set_tracepoints_handlers(struct evlist *evlist,
209 				       const struct evsel_str_handler *assocs, size_t nr_assocs)
210 {
211 	size_t i;
212 	int err;
213 
214 	for (i = 0; i < nr_assocs; i++) {
215 		// Adding a handler for an event not in this evlist, just ignore it.
216 		struct evsel *evsel = evlist__find_tracepoint_by_name(evlist, assocs[i].name);
217 		if (evsel == NULL)
218 			continue;
219 
220 		err = -EEXIST;
221 		if (evsel->handler != NULL)
222 			goto out;
223 		evsel->handler = assocs[i].handler;
224 	}
225 
226 	err = 0;
227 out:
228 	return err;
229 }
230 
231 void evlist__set_leader(struct evlist *evlist)
232 {
233 	perf_evlist__set_leader(&evlist->core);
234 }
235 
236 int __evlist__add_default(struct evlist *evlist, bool precise)
237 {
238 	struct evsel *evsel;
239 
240 	evsel = evsel__new_cycles(precise, PERF_TYPE_HARDWARE,
241 				  PERF_COUNT_HW_CPU_CYCLES);
242 	if (evsel == NULL)
243 		return -ENOMEM;
244 
245 	evlist__add(evlist, evsel);
246 	return 0;
247 }
248 
249 static struct evsel *evlist__dummy_event(struct evlist *evlist)
250 {
251 	struct perf_event_attr attr = {
252 		.type	= PERF_TYPE_SOFTWARE,
253 		.config = PERF_COUNT_SW_DUMMY,
254 		.size	= sizeof(attr), /* to capture ABI version */
255 	};
256 
257 	return evsel__new_idx(&attr, evlist->core.nr_entries);
258 }
259 
260 int evlist__add_dummy(struct evlist *evlist)
261 {
262 	struct evsel *evsel = evlist__dummy_event(evlist);
263 
264 	if (evsel == NULL)
265 		return -ENOMEM;
266 
267 	evlist__add(evlist, evsel);
268 	return 0;
269 }
270 
271 struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide)
272 {
273 	struct evsel *evsel = evlist__dummy_event(evlist);
274 
275 	if (!evsel)
276 		return NULL;
277 
278 	evsel->core.attr.exclude_kernel = 1;
279 	evsel->core.attr.exclude_guest = 1;
280 	evsel->core.attr.exclude_hv = 1;
281 	evsel->core.attr.freq = 0;
282 	evsel->core.attr.sample_period = 1;
283 	evsel->core.system_wide = system_wide;
284 	evsel->no_aux_samples = true;
285 	evsel->name = strdup("dummy:u");
286 
287 	evlist__add(evlist, evsel);
288 	return evsel;
289 }
290 
291 struct evsel *evlist__add_sched_switch(struct evlist *evlist, bool system_wide)
292 {
293 	struct evsel *evsel = evsel__newtp_idx("sched", "sched_switch", 0);
294 
295 	if (IS_ERR(evsel))
296 		return evsel;
297 
298 	evsel__set_sample_bit(evsel, CPU);
299 	evsel__set_sample_bit(evsel, TIME);
300 
301 	evsel->core.system_wide = system_wide;
302 	evsel->no_aux_samples = true;
303 
304 	evlist__add(evlist, evsel);
305 	return evsel;
306 };
307 
308 int evlist__add_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
309 {
310 	struct evsel *evsel, *n;
311 	LIST_HEAD(head);
312 	size_t i;
313 
314 	for (i = 0; i < nr_attrs; i++) {
315 		evsel = evsel__new_idx(attrs + i, evlist->core.nr_entries + i);
316 		if (evsel == NULL)
317 			goto out_delete_partial_list;
318 		list_add_tail(&evsel->core.node, &head);
319 	}
320 
321 	evlist__splice_list_tail(evlist, &head);
322 
323 	return 0;
324 
325 out_delete_partial_list:
326 	__evlist__for_each_entry_safe(&head, n, evsel)
327 		evsel__delete(evsel);
328 	return -1;
329 }
330 
331 int __evlist__add_default_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
332 {
333 	size_t i;
334 
335 	for (i = 0; i < nr_attrs; i++)
336 		event_attr_init(attrs + i);
337 
338 	return evlist__add_attrs(evlist, attrs, nr_attrs);
339 }
340 
341 __weak int arch_evlist__add_default_attrs(struct evlist *evlist,
342 					  struct perf_event_attr *attrs,
343 					  size_t nr_attrs)
344 {
345 	if (!nr_attrs)
346 		return 0;
347 
348 	return __evlist__add_default_attrs(evlist, attrs, nr_attrs);
349 }
350 
351 struct evsel *evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
352 {
353 	struct evsel *evsel;
354 
355 	evlist__for_each_entry(evlist, evsel) {
356 		if (evsel->core.attr.type   == PERF_TYPE_TRACEPOINT &&
357 		    (int)evsel->core.attr.config == id)
358 			return evsel;
359 	}
360 
361 	return NULL;
362 }
363 
364 struct evsel *evlist__find_tracepoint_by_name(struct evlist *evlist, const char *name)
365 {
366 	struct evsel *evsel;
367 
368 	evlist__for_each_entry(evlist, evsel) {
369 		if ((evsel->core.attr.type == PERF_TYPE_TRACEPOINT) &&
370 		    (strcmp(evsel->name, name) == 0))
371 			return evsel;
372 	}
373 
374 	return NULL;
375 }
376 
377 int evlist__add_newtp(struct evlist *evlist, const char *sys, const char *name, void *handler)
378 {
379 	struct evsel *evsel = evsel__newtp(sys, name);
380 
381 	if (IS_ERR(evsel))
382 		return -1;
383 
384 	evsel->handler = handler;
385 	evlist__add(evlist, evsel);
386 	return 0;
387 }
388 
389 struct evlist_cpu_iterator evlist__cpu_begin(struct evlist *evlist, struct affinity *affinity)
390 {
391 	struct evlist_cpu_iterator itr = {
392 		.container = evlist,
393 		.evsel = NULL,
394 		.cpu_map_idx = 0,
395 		.evlist_cpu_map_idx = 0,
396 		.evlist_cpu_map_nr = perf_cpu_map__nr(evlist->core.all_cpus),
397 		.cpu = (struct perf_cpu){ .cpu = -1},
398 		.affinity = affinity,
399 	};
400 
401 	if (evlist__empty(evlist)) {
402 		/* Ensure the empty list doesn't iterate. */
403 		itr.evlist_cpu_map_idx = itr.evlist_cpu_map_nr;
404 	} else {
405 		itr.evsel = evlist__first(evlist);
406 		if (itr.affinity) {
407 			itr.cpu = perf_cpu_map__cpu(evlist->core.all_cpus, 0);
408 			affinity__set(itr.affinity, itr.cpu.cpu);
409 			itr.cpu_map_idx = perf_cpu_map__idx(itr.evsel->core.cpus, itr.cpu);
410 			/*
411 			 * If this CPU isn't in the evsel's cpu map then advance
412 			 * through the list.
413 			 */
414 			if (itr.cpu_map_idx == -1)
415 				evlist_cpu_iterator__next(&itr);
416 		}
417 	}
418 	return itr;
419 }
420 
421 void evlist_cpu_iterator__next(struct evlist_cpu_iterator *evlist_cpu_itr)
422 {
423 	while (evlist_cpu_itr->evsel != evlist__last(evlist_cpu_itr->container)) {
424 		evlist_cpu_itr->evsel = evsel__next(evlist_cpu_itr->evsel);
425 		evlist_cpu_itr->cpu_map_idx =
426 			perf_cpu_map__idx(evlist_cpu_itr->evsel->core.cpus,
427 					  evlist_cpu_itr->cpu);
428 		if (evlist_cpu_itr->cpu_map_idx != -1)
429 			return;
430 	}
431 	evlist_cpu_itr->evlist_cpu_map_idx++;
432 	if (evlist_cpu_itr->evlist_cpu_map_idx < evlist_cpu_itr->evlist_cpu_map_nr) {
433 		evlist_cpu_itr->evsel = evlist__first(evlist_cpu_itr->container);
434 		evlist_cpu_itr->cpu =
435 			perf_cpu_map__cpu(evlist_cpu_itr->container->core.all_cpus,
436 					  evlist_cpu_itr->evlist_cpu_map_idx);
437 		if (evlist_cpu_itr->affinity)
438 			affinity__set(evlist_cpu_itr->affinity, evlist_cpu_itr->cpu.cpu);
439 		evlist_cpu_itr->cpu_map_idx =
440 			perf_cpu_map__idx(evlist_cpu_itr->evsel->core.cpus,
441 					  evlist_cpu_itr->cpu);
442 		/*
443 		 * If this CPU isn't in the evsel's cpu map then advance through
444 		 * the list.
445 		 */
446 		if (evlist_cpu_itr->cpu_map_idx == -1)
447 			evlist_cpu_iterator__next(evlist_cpu_itr);
448 	}
449 }
450 
451 bool evlist_cpu_iterator__end(const struct evlist_cpu_iterator *evlist_cpu_itr)
452 {
453 	return evlist_cpu_itr->evlist_cpu_map_idx >= evlist_cpu_itr->evlist_cpu_map_nr;
454 }
455 
456 static int evsel__strcmp(struct evsel *pos, char *evsel_name)
457 {
458 	if (!evsel_name)
459 		return 0;
460 	if (evsel__is_dummy_event(pos))
461 		return 1;
462 	return strcmp(pos->name, evsel_name);
463 }
464 
465 static int evlist__is_enabled(struct evlist *evlist)
466 {
467 	struct evsel *pos;
468 
469 	evlist__for_each_entry(evlist, pos) {
470 		if (!evsel__is_group_leader(pos) || !pos->core.fd)
471 			continue;
472 		/* If at least one event is enabled, evlist is enabled. */
473 		if (!pos->disabled)
474 			return true;
475 	}
476 	return false;
477 }
478 
479 static void __evlist__disable(struct evlist *evlist, char *evsel_name, bool excl_dummy)
480 {
481 	struct evsel *pos;
482 	struct evlist_cpu_iterator evlist_cpu_itr;
483 	struct affinity saved_affinity, *affinity = NULL;
484 	bool has_imm = false;
485 
486 	// See explanation in evlist__close()
487 	if (!cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
488 		if (affinity__setup(&saved_affinity) < 0)
489 			return;
490 		affinity = &saved_affinity;
491 	}
492 
493 	/* Disable 'immediate' events last */
494 	for (int imm = 0; imm <= 1; imm++) {
495 		evlist__for_each_cpu(evlist_cpu_itr, evlist, affinity) {
496 			pos = evlist_cpu_itr.evsel;
497 			if (evsel__strcmp(pos, evsel_name))
498 				continue;
499 			if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
500 				continue;
501 			if (excl_dummy && evsel__is_dummy_event(pos))
502 				continue;
503 			if (pos->immediate)
504 				has_imm = true;
505 			if (pos->immediate != imm)
506 				continue;
507 			evsel__disable_cpu(pos, evlist_cpu_itr.cpu_map_idx);
508 		}
509 		if (!has_imm)
510 			break;
511 	}
512 
513 	affinity__cleanup(affinity);
514 	evlist__for_each_entry(evlist, pos) {
515 		if (evsel__strcmp(pos, evsel_name))
516 			continue;
517 		if (!evsel__is_group_leader(pos) || !pos->core.fd)
518 			continue;
519 		if (excl_dummy && evsel__is_dummy_event(pos))
520 			continue;
521 		pos->disabled = true;
522 	}
523 
524 	/*
525 	 * If we disabled only single event, we need to check
526 	 * the enabled state of the evlist manually.
527 	 */
528 	if (evsel_name)
529 		evlist->enabled = evlist__is_enabled(evlist);
530 	else
531 		evlist->enabled = false;
532 }
533 
534 void evlist__disable(struct evlist *evlist)
535 {
536 	__evlist__disable(evlist, NULL, false);
537 }
538 
539 void evlist__disable_non_dummy(struct evlist *evlist)
540 {
541 	__evlist__disable(evlist, NULL, true);
542 }
543 
544 void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
545 {
546 	__evlist__disable(evlist, evsel_name, false);
547 }
548 
549 static void __evlist__enable(struct evlist *evlist, char *evsel_name, bool excl_dummy)
550 {
551 	struct evsel *pos;
552 	struct evlist_cpu_iterator evlist_cpu_itr;
553 	struct affinity saved_affinity, *affinity = NULL;
554 
555 	// See explanation in evlist__close()
556 	if (!cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
557 		if (affinity__setup(&saved_affinity) < 0)
558 			return;
559 		affinity = &saved_affinity;
560 	}
561 
562 	evlist__for_each_cpu(evlist_cpu_itr, evlist, affinity) {
563 		pos = evlist_cpu_itr.evsel;
564 		if (evsel__strcmp(pos, evsel_name))
565 			continue;
566 		if (!evsel__is_group_leader(pos) || !pos->core.fd)
567 			continue;
568 		if (excl_dummy && evsel__is_dummy_event(pos))
569 			continue;
570 		evsel__enable_cpu(pos, evlist_cpu_itr.cpu_map_idx);
571 	}
572 	affinity__cleanup(affinity);
573 	evlist__for_each_entry(evlist, pos) {
574 		if (evsel__strcmp(pos, evsel_name))
575 			continue;
576 		if (!evsel__is_group_leader(pos) || !pos->core.fd)
577 			continue;
578 		if (excl_dummy && evsel__is_dummy_event(pos))
579 			continue;
580 		pos->disabled = false;
581 	}
582 
583 	/*
584 	 * Even single event sets the 'enabled' for evlist,
585 	 * so the toggle can work properly and toggle to
586 	 * 'disabled' state.
587 	 */
588 	evlist->enabled = true;
589 }
590 
591 void evlist__enable(struct evlist *evlist)
592 {
593 	__evlist__enable(evlist, NULL, false);
594 }
595 
596 void evlist__enable_non_dummy(struct evlist *evlist)
597 {
598 	__evlist__enable(evlist, NULL, true);
599 }
600 
601 void evlist__enable_evsel(struct evlist *evlist, char *evsel_name)
602 {
603 	__evlist__enable(evlist, evsel_name, false);
604 }
605 
606 void evlist__toggle_enable(struct evlist *evlist)
607 {
608 	(evlist->enabled ? evlist__disable : evlist__enable)(evlist);
609 }
610 
611 int evlist__add_pollfd(struct evlist *evlist, int fd)
612 {
613 	return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN, fdarray_flag__default);
614 }
615 
616 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
617 {
618 	return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
619 }
620 
621 #ifdef HAVE_EVENTFD_SUPPORT
622 int evlist__add_wakeup_eventfd(struct evlist *evlist, int fd)
623 {
624 	return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
625 				       fdarray_flag__nonfilterable |
626 				       fdarray_flag__non_perf_event);
627 }
628 #endif
629 
630 int evlist__poll(struct evlist *evlist, int timeout)
631 {
632 	return perf_evlist__poll(&evlist->core, timeout);
633 }
634 
635 struct perf_sample_id *evlist__id2sid(struct evlist *evlist, u64 id)
636 {
637 	struct hlist_head *head;
638 	struct perf_sample_id *sid;
639 	int hash;
640 
641 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
642 	head = &evlist->core.heads[hash];
643 
644 	hlist_for_each_entry(sid, head, node)
645 		if (sid->id == id)
646 			return sid;
647 
648 	return NULL;
649 }
650 
651 struct evsel *evlist__id2evsel(struct evlist *evlist, u64 id)
652 {
653 	struct perf_sample_id *sid;
654 
655 	if (evlist->core.nr_entries == 1 || !id)
656 		return evlist__first(evlist);
657 
658 	sid = evlist__id2sid(evlist, id);
659 	if (sid)
660 		return container_of(sid->evsel, struct evsel, core);
661 
662 	if (!evlist__sample_id_all(evlist))
663 		return evlist__first(evlist);
664 
665 	return NULL;
666 }
667 
668 struct evsel *evlist__id2evsel_strict(struct evlist *evlist, u64 id)
669 {
670 	struct perf_sample_id *sid;
671 
672 	if (!id)
673 		return NULL;
674 
675 	sid = evlist__id2sid(evlist, id);
676 	if (sid)
677 		return container_of(sid->evsel, struct evsel, core);
678 
679 	return NULL;
680 }
681 
682 static int evlist__event2id(struct evlist *evlist, union perf_event *event, u64 *id)
683 {
684 	const __u64 *array = event->sample.array;
685 	ssize_t n;
686 
687 	n = (event->header.size - sizeof(event->header)) >> 3;
688 
689 	if (event->header.type == PERF_RECORD_SAMPLE) {
690 		if (evlist->id_pos >= n)
691 			return -1;
692 		*id = array[evlist->id_pos];
693 	} else {
694 		if (evlist->is_pos > n)
695 			return -1;
696 		n -= evlist->is_pos;
697 		*id = array[n];
698 	}
699 	return 0;
700 }
701 
702 struct evsel *evlist__event2evsel(struct evlist *evlist, union perf_event *event)
703 {
704 	struct evsel *first = evlist__first(evlist);
705 	struct hlist_head *head;
706 	struct perf_sample_id *sid;
707 	int hash;
708 	u64 id;
709 
710 	if (evlist->core.nr_entries == 1)
711 		return first;
712 
713 	if (!first->core.attr.sample_id_all &&
714 	    event->header.type != PERF_RECORD_SAMPLE)
715 		return first;
716 
717 	if (evlist__event2id(evlist, event, &id))
718 		return NULL;
719 
720 	/* Synthesized events have an id of zero */
721 	if (!id)
722 		return first;
723 
724 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
725 	head = &evlist->core.heads[hash];
726 
727 	hlist_for_each_entry(sid, head, node) {
728 		if (sid->id == id)
729 			return container_of(sid->evsel, struct evsel, core);
730 	}
731 	return NULL;
732 }
733 
734 static int evlist__set_paused(struct evlist *evlist, bool value)
735 {
736 	int i;
737 
738 	if (!evlist->overwrite_mmap)
739 		return 0;
740 
741 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
742 		int fd = evlist->overwrite_mmap[i].core.fd;
743 		int err;
744 
745 		if (fd < 0)
746 			continue;
747 		err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
748 		if (err)
749 			return err;
750 	}
751 	return 0;
752 }
753 
754 static int evlist__pause(struct evlist *evlist)
755 {
756 	return evlist__set_paused(evlist, true);
757 }
758 
759 static int evlist__resume(struct evlist *evlist)
760 {
761 	return evlist__set_paused(evlist, false);
762 }
763 
764 static void evlist__munmap_nofree(struct evlist *evlist)
765 {
766 	int i;
767 
768 	if (evlist->mmap)
769 		for (i = 0; i < evlist->core.nr_mmaps; i++)
770 			perf_mmap__munmap(&evlist->mmap[i].core);
771 
772 	if (evlist->overwrite_mmap)
773 		for (i = 0; i < evlist->core.nr_mmaps; i++)
774 			perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
775 }
776 
777 void evlist__munmap(struct evlist *evlist)
778 {
779 	evlist__munmap_nofree(evlist);
780 	zfree(&evlist->mmap);
781 	zfree(&evlist->overwrite_mmap);
782 }
783 
784 static void perf_mmap__unmap_cb(struct perf_mmap *map)
785 {
786 	struct mmap *m = container_of(map, struct mmap, core);
787 
788 	mmap__munmap(m);
789 }
790 
791 static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
792 				       bool overwrite)
793 {
794 	int i;
795 	struct mmap *map;
796 
797 	map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
798 	if (!map)
799 		return NULL;
800 
801 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
802 		struct perf_mmap *prev = i ? &map[i - 1].core : NULL;
803 
804 		/*
805 		 * When the perf_mmap() call is made we grab one refcount, plus
806 		 * one extra to let perf_mmap__consume() get the last
807 		 * events after all real references (perf_mmap__get()) are
808 		 * dropped.
809 		 *
810 		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
811 		 * thus does perf_mmap__get() on it.
812 		 */
813 		perf_mmap__init(&map[i].core, prev, overwrite, perf_mmap__unmap_cb);
814 	}
815 
816 	return map;
817 }
818 
819 static void
820 perf_evlist__mmap_cb_idx(struct perf_evlist *_evlist,
821 			 struct perf_evsel *_evsel,
822 			 struct perf_mmap_param *_mp,
823 			 int idx)
824 {
825 	struct evlist *evlist = container_of(_evlist, struct evlist, core);
826 	struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
827 	struct evsel *evsel = container_of(_evsel, struct evsel, core);
828 
829 	auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, evsel, idx);
830 }
831 
832 static struct perf_mmap*
833 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
834 {
835 	struct evlist *evlist = container_of(_evlist, struct evlist, core);
836 	struct mmap *maps;
837 
838 	maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
839 
840 	if (!maps) {
841 		maps = evlist__alloc_mmap(evlist, overwrite);
842 		if (!maps)
843 			return NULL;
844 
845 		if (overwrite) {
846 			evlist->overwrite_mmap = maps;
847 			if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
848 				evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
849 		} else {
850 			evlist->mmap = maps;
851 		}
852 	}
853 
854 	return &maps[idx].core;
855 }
856 
857 static int
858 perf_evlist__mmap_cb_mmap(struct perf_mmap *_map, struct perf_mmap_param *_mp,
859 			  int output, struct perf_cpu cpu)
860 {
861 	struct mmap *map = container_of(_map, struct mmap, core);
862 	struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
863 
864 	return mmap__mmap(map, mp, output, cpu);
865 }
866 
867 unsigned long perf_event_mlock_kb_in_pages(void)
868 {
869 	unsigned long pages;
870 	int max;
871 
872 	if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
873 		/*
874 		 * Pick a once upon a time good value, i.e. things look
875 		 * strange since we can't read a sysctl value, but lets not
876 		 * die yet...
877 		 */
878 		max = 512;
879 	} else {
880 		max -= (page_size / 1024);
881 	}
882 
883 	pages = (max * 1024) / page_size;
884 	if (!is_power_of_2(pages))
885 		pages = rounddown_pow_of_two(pages);
886 
887 	return pages;
888 }
889 
890 size_t evlist__mmap_size(unsigned long pages)
891 {
892 	if (pages == UINT_MAX)
893 		pages = perf_event_mlock_kb_in_pages();
894 	else if (!is_power_of_2(pages))
895 		return 0;
896 
897 	return (pages + 1) * page_size;
898 }
899 
900 static long parse_pages_arg(const char *str, unsigned long min,
901 			    unsigned long max)
902 {
903 	unsigned long pages, val;
904 	static struct parse_tag tags[] = {
905 		{ .tag  = 'B', .mult = 1       },
906 		{ .tag  = 'K', .mult = 1 << 10 },
907 		{ .tag  = 'M', .mult = 1 << 20 },
908 		{ .tag  = 'G', .mult = 1 << 30 },
909 		{ .tag  = 0 },
910 	};
911 
912 	if (str == NULL)
913 		return -EINVAL;
914 
915 	val = parse_tag_value(str, tags);
916 	if (val != (unsigned long) -1) {
917 		/* we got file size value */
918 		pages = PERF_ALIGN(val, page_size) / page_size;
919 	} else {
920 		/* we got pages count value */
921 		char *eptr;
922 		pages = strtoul(str, &eptr, 10);
923 		if (*eptr != '\0')
924 			return -EINVAL;
925 	}
926 
927 	if (pages == 0 && min == 0) {
928 		/* leave number of pages at 0 */
929 	} else if (!is_power_of_2(pages)) {
930 		char buf[100];
931 
932 		/* round pages up to next power of 2 */
933 		pages = roundup_pow_of_two(pages);
934 		if (!pages)
935 			return -EINVAL;
936 
937 		unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
938 		pr_info("rounding mmap pages size to %s (%lu pages)\n",
939 			buf, pages);
940 	}
941 
942 	if (pages > max)
943 		return -EINVAL;
944 
945 	return pages;
946 }
947 
948 int __evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
949 {
950 	unsigned long max = UINT_MAX;
951 	long pages;
952 
953 	if (max > SIZE_MAX / page_size)
954 		max = SIZE_MAX / page_size;
955 
956 	pages = parse_pages_arg(str, 1, max);
957 	if (pages < 0) {
958 		pr_err("Invalid argument for --mmap_pages/-m\n");
959 		return -1;
960 	}
961 
962 	*mmap_pages = pages;
963 	return 0;
964 }
965 
966 int evlist__parse_mmap_pages(const struct option *opt, const char *str, int unset __maybe_unused)
967 {
968 	return __evlist__parse_mmap_pages(opt->value, str);
969 }
970 
971 /**
972  * evlist__mmap_ex - Create mmaps to receive events.
973  * @evlist: list of events
974  * @pages: map length in pages
975  * @overwrite: overwrite older events?
976  * @auxtrace_pages - auxtrace map length in pages
977  * @auxtrace_overwrite - overwrite older auxtrace data?
978  *
979  * If @overwrite is %false the user needs to signal event consumption using
980  * perf_mmap__write_tail().  Using evlist__mmap_read() does this
981  * automatically.
982  *
983  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
984  * consumption using auxtrace_mmap__write_tail().
985  *
986  * Return: %0 on success, negative error code otherwise.
987  */
988 int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
989 			 unsigned int auxtrace_pages,
990 			 bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
991 			 int comp_level)
992 {
993 	/*
994 	 * Delay setting mp.prot: set it before calling perf_mmap__mmap.
995 	 * Its value is decided by evsel's write_backward.
996 	 * So &mp should not be passed through const pointer.
997 	 */
998 	struct mmap_params mp = {
999 		.nr_cblocks	= nr_cblocks,
1000 		.affinity	= affinity,
1001 		.flush		= flush,
1002 		.comp_level	= comp_level
1003 	};
1004 	struct perf_evlist_mmap_ops ops = {
1005 		.idx  = perf_evlist__mmap_cb_idx,
1006 		.get  = perf_evlist__mmap_cb_get,
1007 		.mmap = perf_evlist__mmap_cb_mmap,
1008 	};
1009 
1010 	evlist->core.mmap_len = evlist__mmap_size(pages);
1011 	pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
1012 
1013 	auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
1014 				   auxtrace_pages, auxtrace_overwrite);
1015 
1016 	return perf_evlist__mmap_ops(&evlist->core, &ops, &mp.core);
1017 }
1018 
1019 int evlist__mmap(struct evlist *evlist, unsigned int pages)
1020 {
1021 	return evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
1022 }
1023 
1024 int evlist__create_maps(struct evlist *evlist, struct target *target)
1025 {
1026 	bool all_threads = (target->per_thread && target->system_wide);
1027 	struct perf_cpu_map *cpus;
1028 	struct perf_thread_map *threads;
1029 
1030 	/*
1031 	 * If specify '-a' and '--per-thread' to perf record, perf record
1032 	 * will override '--per-thread'. target->per_thread = false and
1033 	 * target->system_wide = true.
1034 	 *
1035 	 * If specify '--per-thread' only to perf record,
1036 	 * target->per_thread = true and target->system_wide = false.
1037 	 *
1038 	 * So target->per_thread && target->system_wide is false.
1039 	 * For perf record, thread_map__new_str doesn't call
1040 	 * thread_map__new_all_cpus. That will keep perf record's
1041 	 * current behavior.
1042 	 *
1043 	 * For perf stat, it allows the case that target->per_thread and
1044 	 * target->system_wide are all true. It means to collect system-wide
1045 	 * per-thread data. thread_map__new_str will call
1046 	 * thread_map__new_all_cpus to enumerate all threads.
1047 	 */
1048 	threads = thread_map__new_str(target->pid, target->tid, target->uid,
1049 				      all_threads);
1050 
1051 	if (!threads)
1052 		return -1;
1053 
1054 	if (target__uses_dummy_map(target))
1055 		cpus = perf_cpu_map__dummy_new();
1056 	else
1057 		cpus = perf_cpu_map__new(target->cpu_list);
1058 
1059 	if (!cpus)
1060 		goto out_delete_threads;
1061 
1062 	evlist->core.has_user_cpus = !!target->cpu_list && !target->hybrid;
1063 
1064 	perf_evlist__set_maps(&evlist->core, cpus, threads);
1065 
1066 	/* as evlist now has references, put count here */
1067 	perf_cpu_map__put(cpus);
1068 	perf_thread_map__put(threads);
1069 
1070 	return 0;
1071 
1072 out_delete_threads:
1073 	perf_thread_map__put(threads);
1074 	return -1;
1075 }
1076 
1077 int evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
1078 {
1079 	struct evsel *evsel;
1080 	int err = 0;
1081 
1082 	evlist__for_each_entry(evlist, evsel) {
1083 		if (evsel->filter == NULL)
1084 			continue;
1085 
1086 		/*
1087 		 * filters only work for tracepoint event, which doesn't have cpu limit.
1088 		 * So evlist and evsel should always be same.
1089 		 */
1090 		err = perf_evsel__apply_filter(&evsel->core, evsel->filter);
1091 		if (err) {
1092 			*err_evsel = evsel;
1093 			break;
1094 		}
1095 	}
1096 
1097 	return err;
1098 }
1099 
1100 int evlist__set_tp_filter(struct evlist *evlist, const char *filter)
1101 {
1102 	struct evsel *evsel;
1103 	int err = 0;
1104 
1105 	if (filter == NULL)
1106 		return -1;
1107 
1108 	evlist__for_each_entry(evlist, evsel) {
1109 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1110 			continue;
1111 
1112 		err = evsel__set_filter(evsel, filter);
1113 		if (err)
1114 			break;
1115 	}
1116 
1117 	return err;
1118 }
1119 
1120 int evlist__append_tp_filter(struct evlist *evlist, const char *filter)
1121 {
1122 	struct evsel *evsel;
1123 	int err = 0;
1124 
1125 	if (filter == NULL)
1126 		return -1;
1127 
1128 	evlist__for_each_entry(evlist, evsel) {
1129 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1130 			continue;
1131 
1132 		err = evsel__append_tp_filter(evsel, filter);
1133 		if (err)
1134 			break;
1135 	}
1136 
1137 	return err;
1138 }
1139 
1140 char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
1141 {
1142 	char *filter;
1143 	size_t i;
1144 
1145 	for (i = 0; i < npids; ++i) {
1146 		if (i == 0) {
1147 			if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1148 				return NULL;
1149 		} else {
1150 			char *tmp;
1151 
1152 			if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1153 				goto out_free;
1154 
1155 			free(filter);
1156 			filter = tmp;
1157 		}
1158 	}
1159 
1160 	return filter;
1161 out_free:
1162 	free(filter);
1163 	return NULL;
1164 }
1165 
1166 int evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1167 {
1168 	char *filter = asprintf__tp_filter_pids(npids, pids);
1169 	int ret = evlist__set_tp_filter(evlist, filter);
1170 
1171 	free(filter);
1172 	return ret;
1173 }
1174 
1175 int evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1176 {
1177 	return evlist__set_tp_filter_pids(evlist, 1, &pid);
1178 }
1179 
1180 int evlist__append_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1181 {
1182 	char *filter = asprintf__tp_filter_pids(npids, pids);
1183 	int ret = evlist__append_tp_filter(evlist, filter);
1184 
1185 	free(filter);
1186 	return ret;
1187 }
1188 
1189 int evlist__append_tp_filter_pid(struct evlist *evlist, pid_t pid)
1190 {
1191 	return evlist__append_tp_filter_pids(evlist, 1, &pid);
1192 }
1193 
1194 bool evlist__valid_sample_type(struct evlist *evlist)
1195 {
1196 	struct evsel *pos;
1197 
1198 	if (evlist->core.nr_entries == 1)
1199 		return true;
1200 
1201 	if (evlist->id_pos < 0 || evlist->is_pos < 0)
1202 		return false;
1203 
1204 	evlist__for_each_entry(evlist, pos) {
1205 		if (pos->id_pos != evlist->id_pos ||
1206 		    pos->is_pos != evlist->is_pos)
1207 			return false;
1208 	}
1209 
1210 	return true;
1211 }
1212 
1213 u64 __evlist__combined_sample_type(struct evlist *evlist)
1214 {
1215 	struct evsel *evsel;
1216 
1217 	if (evlist->combined_sample_type)
1218 		return evlist->combined_sample_type;
1219 
1220 	evlist__for_each_entry(evlist, evsel)
1221 		evlist->combined_sample_type |= evsel->core.attr.sample_type;
1222 
1223 	return evlist->combined_sample_type;
1224 }
1225 
1226 u64 evlist__combined_sample_type(struct evlist *evlist)
1227 {
1228 	evlist->combined_sample_type = 0;
1229 	return __evlist__combined_sample_type(evlist);
1230 }
1231 
1232 u64 evlist__combined_branch_type(struct evlist *evlist)
1233 {
1234 	struct evsel *evsel;
1235 	u64 branch_type = 0;
1236 
1237 	evlist__for_each_entry(evlist, evsel)
1238 		branch_type |= evsel->core.attr.branch_sample_type;
1239 	return branch_type;
1240 }
1241 
1242 bool evlist__valid_read_format(struct evlist *evlist)
1243 {
1244 	struct evsel *first = evlist__first(evlist), *pos = first;
1245 	u64 read_format = first->core.attr.read_format;
1246 	u64 sample_type = first->core.attr.sample_type;
1247 
1248 	evlist__for_each_entry(evlist, pos) {
1249 		if (read_format != pos->core.attr.read_format) {
1250 			pr_debug("Read format differs %#" PRIx64 " vs %#" PRIx64 "\n",
1251 				 read_format, (u64)pos->core.attr.read_format);
1252 		}
1253 	}
1254 
1255 	/* PERF_SAMPLE_READ implies PERF_FORMAT_ID. */
1256 	if ((sample_type & PERF_SAMPLE_READ) &&
1257 	    !(read_format & PERF_FORMAT_ID)) {
1258 		return false;
1259 	}
1260 
1261 	return true;
1262 }
1263 
1264 u16 evlist__id_hdr_size(struct evlist *evlist)
1265 {
1266 	struct evsel *first = evlist__first(evlist);
1267 
1268 	return first->core.attr.sample_id_all ? evsel__id_hdr_size(first) : 0;
1269 }
1270 
1271 bool evlist__valid_sample_id_all(struct evlist *evlist)
1272 {
1273 	struct evsel *first = evlist__first(evlist), *pos = first;
1274 
1275 	evlist__for_each_entry_continue(evlist, pos) {
1276 		if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1277 			return false;
1278 	}
1279 
1280 	return true;
1281 }
1282 
1283 bool evlist__sample_id_all(struct evlist *evlist)
1284 {
1285 	struct evsel *first = evlist__first(evlist);
1286 	return first->core.attr.sample_id_all;
1287 }
1288 
1289 void evlist__set_selected(struct evlist *evlist, struct evsel *evsel)
1290 {
1291 	evlist->selected = evsel;
1292 }
1293 
1294 void evlist__close(struct evlist *evlist)
1295 {
1296 	struct evsel *evsel;
1297 	struct evlist_cpu_iterator evlist_cpu_itr;
1298 	struct affinity affinity;
1299 
1300 	/*
1301 	 * With perf record core.user_requested_cpus is usually NULL.
1302 	 * Use the old method to handle this for now.
1303 	 */
1304 	if (!evlist->core.user_requested_cpus ||
1305 	    cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
1306 		evlist__for_each_entry_reverse(evlist, evsel)
1307 			evsel__close(evsel);
1308 		return;
1309 	}
1310 
1311 	if (affinity__setup(&affinity) < 0)
1312 		return;
1313 
1314 	evlist__for_each_cpu(evlist_cpu_itr, evlist, &affinity) {
1315 		perf_evsel__close_cpu(&evlist_cpu_itr.evsel->core,
1316 				      evlist_cpu_itr.cpu_map_idx);
1317 	}
1318 
1319 	affinity__cleanup(&affinity);
1320 	evlist__for_each_entry_reverse(evlist, evsel) {
1321 		perf_evsel__free_fd(&evsel->core);
1322 		perf_evsel__free_id(&evsel->core);
1323 	}
1324 	perf_evlist__reset_id_hash(&evlist->core);
1325 }
1326 
1327 static int evlist__create_syswide_maps(struct evlist *evlist)
1328 {
1329 	struct perf_cpu_map *cpus;
1330 	struct perf_thread_map *threads;
1331 
1332 	/*
1333 	 * Try reading /sys/devices/system/cpu/online to get
1334 	 * an all cpus map.
1335 	 *
1336 	 * FIXME: -ENOMEM is the best we can do here, the cpu_map
1337 	 * code needs an overhaul to properly forward the
1338 	 * error, and we may not want to do that fallback to a
1339 	 * default cpu identity map :-\
1340 	 */
1341 	cpus = perf_cpu_map__new(NULL);
1342 	if (!cpus)
1343 		goto out;
1344 
1345 	threads = perf_thread_map__new_dummy();
1346 	if (!threads)
1347 		goto out_put;
1348 
1349 	perf_evlist__set_maps(&evlist->core, cpus, threads);
1350 
1351 	perf_thread_map__put(threads);
1352 out_put:
1353 	perf_cpu_map__put(cpus);
1354 out:
1355 	return -ENOMEM;
1356 }
1357 
1358 int evlist__open(struct evlist *evlist)
1359 {
1360 	struct evsel *evsel;
1361 	int err;
1362 
1363 	/*
1364 	 * Default: one fd per CPU, all threads, aka systemwide
1365 	 * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1366 	 */
1367 	if (evlist->core.threads == NULL && evlist->core.user_requested_cpus == NULL) {
1368 		err = evlist__create_syswide_maps(evlist);
1369 		if (err < 0)
1370 			goto out_err;
1371 	}
1372 
1373 	evlist__update_id_pos(evlist);
1374 
1375 	evlist__for_each_entry(evlist, evsel) {
1376 		err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1377 		if (err < 0)
1378 			goto out_err;
1379 	}
1380 
1381 	return 0;
1382 out_err:
1383 	evlist__close(evlist);
1384 	errno = -err;
1385 	return err;
1386 }
1387 
1388 int evlist__prepare_workload(struct evlist *evlist, struct target *target, const char *argv[],
1389 			     bool pipe_output, void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1390 {
1391 	int child_ready_pipe[2], go_pipe[2];
1392 	char bf;
1393 
1394 	if (pipe(child_ready_pipe) < 0) {
1395 		perror("failed to create 'ready' pipe");
1396 		return -1;
1397 	}
1398 
1399 	if (pipe(go_pipe) < 0) {
1400 		perror("failed to create 'go' pipe");
1401 		goto out_close_ready_pipe;
1402 	}
1403 
1404 	evlist->workload.pid = fork();
1405 	if (evlist->workload.pid < 0) {
1406 		perror("failed to fork");
1407 		goto out_close_pipes;
1408 	}
1409 
1410 	if (!evlist->workload.pid) {
1411 		int ret;
1412 
1413 		if (pipe_output)
1414 			dup2(2, 1);
1415 
1416 		signal(SIGTERM, SIG_DFL);
1417 
1418 		close(child_ready_pipe[0]);
1419 		close(go_pipe[1]);
1420 		fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1421 
1422 		/*
1423 		 * Change the name of this process not to confuse --exclude-perf users
1424 		 * that sees 'perf' in the window up to the execvp() and thinks that
1425 		 * perf samples are not being excluded.
1426 		 */
1427 		prctl(PR_SET_NAME, "perf-exec");
1428 
1429 		/*
1430 		 * Tell the parent we're ready to go
1431 		 */
1432 		close(child_ready_pipe[1]);
1433 
1434 		/*
1435 		 * Wait until the parent tells us to go.
1436 		 */
1437 		ret = read(go_pipe[0], &bf, 1);
1438 		/*
1439 		 * The parent will ask for the execvp() to be performed by
1440 		 * writing exactly one byte, in workload.cork_fd, usually via
1441 		 * evlist__start_workload().
1442 		 *
1443 		 * For cancelling the workload without actually running it,
1444 		 * the parent will just close workload.cork_fd, without writing
1445 		 * anything, i.e. read will return zero and we just exit()
1446 		 * here.
1447 		 */
1448 		if (ret != 1) {
1449 			if (ret == -1)
1450 				perror("unable to read pipe");
1451 			exit(ret);
1452 		}
1453 
1454 		execvp(argv[0], (char **)argv);
1455 
1456 		if (exec_error) {
1457 			union sigval val;
1458 
1459 			val.sival_int = errno;
1460 			if (sigqueue(getppid(), SIGUSR1, val))
1461 				perror(argv[0]);
1462 		} else
1463 			perror(argv[0]);
1464 		exit(-1);
1465 	}
1466 
1467 	if (exec_error) {
1468 		struct sigaction act = {
1469 			.sa_flags     = SA_SIGINFO,
1470 			.sa_sigaction = exec_error,
1471 		};
1472 		sigaction(SIGUSR1, &act, NULL);
1473 	}
1474 
1475 	if (target__none(target)) {
1476 		if (evlist->core.threads == NULL) {
1477 			fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1478 				__func__, __LINE__);
1479 			goto out_close_pipes;
1480 		}
1481 		perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1482 	}
1483 
1484 	close(child_ready_pipe[1]);
1485 	close(go_pipe[0]);
1486 	/*
1487 	 * wait for child to settle
1488 	 */
1489 	if (read(child_ready_pipe[0], &bf, 1) == -1) {
1490 		perror("unable to read pipe");
1491 		goto out_close_pipes;
1492 	}
1493 
1494 	fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1495 	evlist->workload.cork_fd = go_pipe[1];
1496 	close(child_ready_pipe[0]);
1497 	return 0;
1498 
1499 out_close_pipes:
1500 	close(go_pipe[0]);
1501 	close(go_pipe[1]);
1502 out_close_ready_pipe:
1503 	close(child_ready_pipe[0]);
1504 	close(child_ready_pipe[1]);
1505 	return -1;
1506 }
1507 
1508 int evlist__start_workload(struct evlist *evlist)
1509 {
1510 	if (evlist->workload.cork_fd > 0) {
1511 		char bf = 0;
1512 		int ret;
1513 		/*
1514 		 * Remove the cork, let it rip!
1515 		 */
1516 		ret = write(evlist->workload.cork_fd, &bf, 1);
1517 		if (ret < 0)
1518 			perror("unable to write to pipe");
1519 
1520 		close(evlist->workload.cork_fd);
1521 		return ret;
1522 	}
1523 
1524 	return 0;
1525 }
1526 
1527 int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample)
1528 {
1529 	struct evsel *evsel = evlist__event2evsel(evlist, event);
1530 	int ret;
1531 
1532 	if (!evsel)
1533 		return -EFAULT;
1534 	ret = evsel__parse_sample(evsel, event, sample);
1535 	if (ret)
1536 		return ret;
1537 	if (perf_guest && sample->id) {
1538 		struct perf_sample_id *sid = evlist__id2sid(evlist, sample->id);
1539 
1540 		if (sid) {
1541 			sample->machine_pid = sid->machine_pid;
1542 			sample->vcpu = sid->vcpu.cpu;
1543 		}
1544 	}
1545 	return 0;
1546 }
1547 
1548 int evlist__parse_sample_timestamp(struct evlist *evlist, union perf_event *event, u64 *timestamp)
1549 {
1550 	struct evsel *evsel = evlist__event2evsel(evlist, event);
1551 
1552 	if (!evsel)
1553 		return -EFAULT;
1554 	return evsel__parse_sample_timestamp(evsel, event, timestamp);
1555 }
1556 
1557 int evlist__strerror_open(struct evlist *evlist, int err, char *buf, size_t size)
1558 {
1559 	int printed, value;
1560 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1561 
1562 	switch (err) {
1563 	case EACCES:
1564 	case EPERM:
1565 		printed = scnprintf(buf, size,
1566 				    "Error:\t%s.\n"
1567 				    "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1568 
1569 		value = perf_event_paranoid();
1570 
1571 		printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1572 
1573 		if (value >= 2) {
1574 			printed += scnprintf(buf + printed, size - printed,
1575 					     "For your workloads it needs to be <= 1\nHint:\t");
1576 		}
1577 		printed += scnprintf(buf + printed, size - printed,
1578 				     "For system wide tracing it needs to be set to -1.\n");
1579 
1580 		printed += scnprintf(buf + printed, size - printed,
1581 				    "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1582 				    "Hint:\tThe current value is %d.", value);
1583 		break;
1584 	case EINVAL: {
1585 		struct evsel *first = evlist__first(evlist);
1586 		int max_freq;
1587 
1588 		if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1589 			goto out_default;
1590 
1591 		if (first->core.attr.sample_freq < (u64)max_freq)
1592 			goto out_default;
1593 
1594 		printed = scnprintf(buf, size,
1595 				    "Error:\t%s.\n"
1596 				    "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1597 				    "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1598 				    emsg, max_freq, first->core.attr.sample_freq);
1599 		break;
1600 	}
1601 	default:
1602 out_default:
1603 		scnprintf(buf, size, "%s", emsg);
1604 		break;
1605 	}
1606 
1607 	return 0;
1608 }
1609 
1610 int evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1611 {
1612 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1613 	int pages_attempted = evlist->core.mmap_len / 1024, pages_max_per_user, printed = 0;
1614 
1615 	switch (err) {
1616 	case EPERM:
1617 		sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1618 		printed += scnprintf(buf + printed, size - printed,
1619 				     "Error:\t%s.\n"
1620 				     "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1621 				     "Hint:\tTried using %zd kB.\n",
1622 				     emsg, pages_max_per_user, pages_attempted);
1623 
1624 		if (pages_attempted >= pages_max_per_user) {
1625 			printed += scnprintf(buf + printed, size - printed,
1626 					     "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1627 					     pages_max_per_user + pages_attempted);
1628 		}
1629 
1630 		printed += scnprintf(buf + printed, size - printed,
1631 				     "Hint:\tTry using a smaller -m/--mmap-pages value.");
1632 		break;
1633 	default:
1634 		scnprintf(buf, size, "%s", emsg);
1635 		break;
1636 	}
1637 
1638 	return 0;
1639 }
1640 
1641 void evlist__to_front(struct evlist *evlist, struct evsel *move_evsel)
1642 {
1643 	struct evsel *evsel, *n;
1644 	LIST_HEAD(move);
1645 
1646 	if (move_evsel == evlist__first(evlist))
1647 		return;
1648 
1649 	evlist__for_each_entry_safe(evlist, n, evsel) {
1650 		if (evsel__leader(evsel) == evsel__leader(move_evsel))
1651 			list_move_tail(&evsel->core.node, &move);
1652 	}
1653 
1654 	list_splice(&move, &evlist->core.entries);
1655 }
1656 
1657 struct evsel *evlist__get_tracking_event(struct evlist *evlist)
1658 {
1659 	struct evsel *evsel;
1660 
1661 	evlist__for_each_entry(evlist, evsel) {
1662 		if (evsel->tracking)
1663 			return evsel;
1664 	}
1665 
1666 	return evlist__first(evlist);
1667 }
1668 
1669 void evlist__set_tracking_event(struct evlist *evlist, struct evsel *tracking_evsel)
1670 {
1671 	struct evsel *evsel;
1672 
1673 	if (tracking_evsel->tracking)
1674 		return;
1675 
1676 	evlist__for_each_entry(evlist, evsel) {
1677 		if (evsel != tracking_evsel)
1678 			evsel->tracking = false;
1679 	}
1680 
1681 	tracking_evsel->tracking = true;
1682 }
1683 
1684 struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str)
1685 {
1686 	struct evsel *evsel;
1687 
1688 	evlist__for_each_entry(evlist, evsel) {
1689 		if (!evsel->name)
1690 			continue;
1691 		if (strcmp(str, evsel->name) == 0)
1692 			return evsel;
1693 	}
1694 
1695 	return NULL;
1696 }
1697 
1698 void evlist__toggle_bkw_mmap(struct evlist *evlist, enum bkw_mmap_state state)
1699 {
1700 	enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1701 	enum action {
1702 		NONE,
1703 		PAUSE,
1704 		RESUME,
1705 	} action = NONE;
1706 
1707 	if (!evlist->overwrite_mmap)
1708 		return;
1709 
1710 	switch (old_state) {
1711 	case BKW_MMAP_NOTREADY: {
1712 		if (state != BKW_MMAP_RUNNING)
1713 			goto state_err;
1714 		break;
1715 	}
1716 	case BKW_MMAP_RUNNING: {
1717 		if (state != BKW_MMAP_DATA_PENDING)
1718 			goto state_err;
1719 		action = PAUSE;
1720 		break;
1721 	}
1722 	case BKW_MMAP_DATA_PENDING: {
1723 		if (state != BKW_MMAP_EMPTY)
1724 			goto state_err;
1725 		break;
1726 	}
1727 	case BKW_MMAP_EMPTY: {
1728 		if (state != BKW_MMAP_RUNNING)
1729 			goto state_err;
1730 		action = RESUME;
1731 		break;
1732 	}
1733 	default:
1734 		WARN_ONCE(1, "Shouldn't get there\n");
1735 	}
1736 
1737 	evlist->bkw_mmap_state = state;
1738 
1739 	switch (action) {
1740 	case PAUSE:
1741 		evlist__pause(evlist);
1742 		break;
1743 	case RESUME:
1744 		evlist__resume(evlist);
1745 		break;
1746 	case NONE:
1747 	default:
1748 		break;
1749 	}
1750 
1751 state_err:
1752 	return;
1753 }
1754 
1755 bool evlist__exclude_kernel(struct evlist *evlist)
1756 {
1757 	struct evsel *evsel;
1758 
1759 	evlist__for_each_entry(evlist, evsel) {
1760 		if (!evsel->core.attr.exclude_kernel)
1761 			return false;
1762 	}
1763 
1764 	return true;
1765 }
1766 
1767 /*
1768  * Events in data file are not collect in groups, but we still want
1769  * the group display. Set the artificial group and set the leader's
1770  * forced_leader flag to notify the display code.
1771  */
1772 void evlist__force_leader(struct evlist *evlist)
1773 {
1774 	if (!evlist->core.nr_groups) {
1775 		struct evsel *leader = evlist__first(evlist);
1776 
1777 		evlist__set_leader(evlist);
1778 		leader->forced_leader = true;
1779 	}
1780 }
1781 
1782 struct evsel *evlist__reset_weak_group(struct evlist *evsel_list, struct evsel *evsel, bool close)
1783 {
1784 	struct evsel *c2, *leader;
1785 	bool is_open = true;
1786 
1787 	leader = evsel__leader(evsel);
1788 
1789 	pr_debug("Weak group for %s/%d failed\n",
1790 			leader->name, leader->core.nr_members);
1791 
1792 	/*
1793 	 * for_each_group_member doesn't work here because it doesn't
1794 	 * include the first entry.
1795 	 */
1796 	evlist__for_each_entry(evsel_list, c2) {
1797 		if (c2 == evsel)
1798 			is_open = false;
1799 		if (evsel__has_leader(c2, leader)) {
1800 			if (is_open && close)
1801 				perf_evsel__close(&c2->core);
1802 			/*
1803 			 * We want to close all members of the group and reopen
1804 			 * them. Some events, like Intel topdown, require being
1805 			 * in a group and so keep these in the group.
1806 			 */
1807 			evsel__remove_from_group(c2, leader);
1808 
1809 			/*
1810 			 * Set this for all former members of the group
1811 			 * to indicate they get reopened.
1812 			 */
1813 			c2->reset_group = true;
1814 		}
1815 	}
1816 	/* Reset the leader count if all entries were removed. */
1817 	if (leader->core.nr_members == 1)
1818 		leader->core.nr_members = 0;
1819 	return leader;
1820 }
1821 
1822 static int evlist__parse_control_fifo(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1823 {
1824 	char *s, *p;
1825 	int ret = 0, fd;
1826 
1827 	if (strncmp(str, "fifo:", 5))
1828 		return -EINVAL;
1829 
1830 	str += 5;
1831 	if (!*str || *str == ',')
1832 		return -EINVAL;
1833 
1834 	s = strdup(str);
1835 	if (!s)
1836 		return -ENOMEM;
1837 
1838 	p = strchr(s, ',');
1839 	if (p)
1840 		*p = '\0';
1841 
1842 	/*
1843 	 * O_RDWR avoids POLLHUPs which is necessary to allow the other
1844 	 * end of a FIFO to be repeatedly opened and closed.
1845 	 */
1846 	fd = open(s, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1847 	if (fd < 0) {
1848 		pr_err("Failed to open '%s'\n", s);
1849 		ret = -errno;
1850 		goto out_free;
1851 	}
1852 	*ctl_fd = fd;
1853 	*ctl_fd_close = true;
1854 
1855 	if (p && *++p) {
1856 		/* O_RDWR | O_NONBLOCK means the other end need not be open */
1857 		fd = open(p, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1858 		if (fd < 0) {
1859 			pr_err("Failed to open '%s'\n", p);
1860 			ret = -errno;
1861 			goto out_free;
1862 		}
1863 		*ctl_fd_ack = fd;
1864 	}
1865 
1866 out_free:
1867 	free(s);
1868 	return ret;
1869 }
1870 
1871 int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1872 {
1873 	char *comma = NULL, *endptr = NULL;
1874 
1875 	*ctl_fd_close = false;
1876 
1877 	if (strncmp(str, "fd:", 3))
1878 		return evlist__parse_control_fifo(str, ctl_fd, ctl_fd_ack, ctl_fd_close);
1879 
1880 	*ctl_fd = strtoul(&str[3], &endptr, 0);
1881 	if (endptr == &str[3])
1882 		return -EINVAL;
1883 
1884 	comma = strchr(str, ',');
1885 	if (comma) {
1886 		if (endptr != comma)
1887 			return -EINVAL;
1888 
1889 		*ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
1890 		if (endptr == comma + 1 || *endptr != '\0')
1891 			return -EINVAL;
1892 	}
1893 
1894 	return 0;
1895 }
1896 
1897 void evlist__close_control(int ctl_fd, int ctl_fd_ack, bool *ctl_fd_close)
1898 {
1899 	if (*ctl_fd_close) {
1900 		*ctl_fd_close = false;
1901 		close(ctl_fd);
1902 		if (ctl_fd_ack >= 0)
1903 			close(ctl_fd_ack);
1904 	}
1905 }
1906 
1907 int evlist__initialize_ctlfd(struct evlist *evlist, int fd, int ack)
1908 {
1909 	if (fd == -1) {
1910 		pr_debug("Control descriptor is not initialized\n");
1911 		return 0;
1912 	}
1913 
1914 	evlist->ctl_fd.pos = perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
1915 						     fdarray_flag__nonfilterable |
1916 						     fdarray_flag__non_perf_event);
1917 	if (evlist->ctl_fd.pos < 0) {
1918 		evlist->ctl_fd.pos = -1;
1919 		pr_err("Failed to add ctl fd entry: %m\n");
1920 		return -1;
1921 	}
1922 
1923 	evlist->ctl_fd.fd = fd;
1924 	evlist->ctl_fd.ack = ack;
1925 
1926 	return 0;
1927 }
1928 
1929 bool evlist__ctlfd_initialized(struct evlist *evlist)
1930 {
1931 	return evlist->ctl_fd.pos >= 0;
1932 }
1933 
1934 int evlist__finalize_ctlfd(struct evlist *evlist)
1935 {
1936 	struct pollfd *entries = evlist->core.pollfd.entries;
1937 
1938 	if (!evlist__ctlfd_initialized(evlist))
1939 		return 0;
1940 
1941 	entries[evlist->ctl_fd.pos].fd = -1;
1942 	entries[evlist->ctl_fd.pos].events = 0;
1943 	entries[evlist->ctl_fd.pos].revents = 0;
1944 
1945 	evlist->ctl_fd.pos = -1;
1946 	evlist->ctl_fd.ack = -1;
1947 	evlist->ctl_fd.fd = -1;
1948 
1949 	return 0;
1950 }
1951 
1952 static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
1953 			      char *cmd_data, size_t data_size)
1954 {
1955 	int err;
1956 	char c;
1957 	size_t bytes_read = 0;
1958 
1959 	*cmd = EVLIST_CTL_CMD_UNSUPPORTED;
1960 	memset(cmd_data, 0, data_size);
1961 	data_size--;
1962 
1963 	do {
1964 		err = read(evlist->ctl_fd.fd, &c, 1);
1965 		if (err > 0) {
1966 			if (c == '\n' || c == '\0')
1967 				break;
1968 			cmd_data[bytes_read++] = c;
1969 			if (bytes_read == data_size)
1970 				break;
1971 			continue;
1972 		} else if (err == -1) {
1973 			if (errno == EINTR)
1974 				continue;
1975 			if (errno == EAGAIN || errno == EWOULDBLOCK)
1976 				err = 0;
1977 			else
1978 				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
1979 		}
1980 		break;
1981 	} while (1);
1982 
1983 	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
1984 		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
1985 
1986 	if (bytes_read > 0) {
1987 		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
1988 			     (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
1989 			*cmd = EVLIST_CTL_CMD_ENABLE;
1990 		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
1991 				    (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
1992 			*cmd = EVLIST_CTL_CMD_DISABLE;
1993 		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG,
1994 				    (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {
1995 			*cmd = EVLIST_CTL_CMD_SNAPSHOT;
1996 			pr_debug("is snapshot\n");
1997 		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_EVLIST_TAG,
1998 				    (sizeof(EVLIST_CTL_CMD_EVLIST_TAG)-1))) {
1999 			*cmd = EVLIST_CTL_CMD_EVLIST;
2000 		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_STOP_TAG,
2001 				    (sizeof(EVLIST_CTL_CMD_STOP_TAG)-1))) {
2002 			*cmd = EVLIST_CTL_CMD_STOP;
2003 		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_PING_TAG,
2004 				    (sizeof(EVLIST_CTL_CMD_PING_TAG)-1))) {
2005 			*cmd = EVLIST_CTL_CMD_PING;
2006 		}
2007 	}
2008 
2009 	return bytes_read ? (int)bytes_read : err;
2010 }
2011 
2012 int evlist__ctlfd_ack(struct evlist *evlist)
2013 {
2014 	int err;
2015 
2016 	if (evlist->ctl_fd.ack == -1)
2017 		return 0;
2018 
2019 	err = write(evlist->ctl_fd.ack, EVLIST_CTL_CMD_ACK_TAG,
2020 		    sizeof(EVLIST_CTL_CMD_ACK_TAG));
2021 	if (err == -1)
2022 		pr_err("failed to write to ctl_ack_fd %d: %m\n", evlist->ctl_fd.ack);
2023 
2024 	return err;
2025 }
2026 
2027 static int get_cmd_arg(char *cmd_data, size_t cmd_size, char **arg)
2028 {
2029 	char *data = cmd_data + cmd_size;
2030 
2031 	/* no argument */
2032 	if (!*data)
2033 		return 0;
2034 
2035 	/* there's argument */
2036 	if (*data == ' ') {
2037 		*arg = data + 1;
2038 		return 1;
2039 	}
2040 
2041 	/* malformed */
2042 	return -1;
2043 }
2044 
2045 static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enable)
2046 {
2047 	struct evsel *evsel;
2048 	char *name;
2049 	int err;
2050 
2051 	err = get_cmd_arg(cmd_data,
2052 			  enable ? sizeof(EVLIST_CTL_CMD_ENABLE_TAG) - 1 :
2053 				   sizeof(EVLIST_CTL_CMD_DISABLE_TAG) - 1,
2054 			  &name);
2055 	if (err < 0) {
2056 		pr_info("failed: wrong command\n");
2057 		return -1;
2058 	}
2059 
2060 	if (err) {
2061 		evsel = evlist__find_evsel_by_str(evlist, name);
2062 		if (evsel) {
2063 			if (enable)
2064 				evlist__enable_evsel(evlist, name);
2065 			else
2066 				evlist__disable_evsel(evlist, name);
2067 			pr_info("Event %s %s\n", evsel->name,
2068 				enable ? "enabled" : "disabled");
2069 		} else {
2070 			pr_info("failed: can't find '%s' event\n", name);
2071 		}
2072 	} else {
2073 		if (enable) {
2074 			evlist__enable(evlist);
2075 			pr_info(EVLIST_ENABLED_MSG);
2076 		} else {
2077 			evlist__disable(evlist);
2078 			pr_info(EVLIST_DISABLED_MSG);
2079 		}
2080 	}
2081 
2082 	return 0;
2083 }
2084 
2085 static int evlist__ctlfd_list(struct evlist *evlist, char *cmd_data)
2086 {
2087 	struct perf_attr_details details = { .verbose = false, };
2088 	struct evsel *evsel;
2089 	char *arg;
2090 	int err;
2091 
2092 	err = get_cmd_arg(cmd_data,
2093 			  sizeof(EVLIST_CTL_CMD_EVLIST_TAG) - 1,
2094 			  &arg);
2095 	if (err < 0) {
2096 		pr_info("failed: wrong command\n");
2097 		return -1;
2098 	}
2099 
2100 	if (err) {
2101 		if (!strcmp(arg, "-v")) {
2102 			details.verbose = true;
2103 		} else if (!strcmp(arg, "-g")) {
2104 			details.event_group = true;
2105 		} else if (!strcmp(arg, "-F")) {
2106 			details.freq = true;
2107 		} else {
2108 			pr_info("failed: wrong command\n");
2109 			return -1;
2110 		}
2111 	}
2112 
2113 	evlist__for_each_entry(evlist, evsel)
2114 		evsel__fprintf(evsel, &details, stderr);
2115 
2116 	return 0;
2117 }
2118 
2119 int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
2120 {
2121 	int err = 0;
2122 	char cmd_data[EVLIST_CTL_CMD_MAX_LEN];
2123 	int ctlfd_pos = evlist->ctl_fd.pos;
2124 	struct pollfd *entries = evlist->core.pollfd.entries;
2125 
2126 	if (!evlist__ctlfd_initialized(evlist) || !entries[ctlfd_pos].revents)
2127 		return 0;
2128 
2129 	if (entries[ctlfd_pos].revents & POLLIN) {
2130 		err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
2131 					 EVLIST_CTL_CMD_MAX_LEN);
2132 		if (err > 0) {
2133 			switch (*cmd) {
2134 			case EVLIST_CTL_CMD_ENABLE:
2135 			case EVLIST_CTL_CMD_DISABLE:
2136 				err = evlist__ctlfd_enable(evlist, cmd_data,
2137 							   *cmd == EVLIST_CTL_CMD_ENABLE);
2138 				break;
2139 			case EVLIST_CTL_CMD_EVLIST:
2140 				err = evlist__ctlfd_list(evlist, cmd_data);
2141 				break;
2142 			case EVLIST_CTL_CMD_SNAPSHOT:
2143 			case EVLIST_CTL_CMD_STOP:
2144 			case EVLIST_CTL_CMD_PING:
2145 				break;
2146 			case EVLIST_CTL_CMD_ACK:
2147 			case EVLIST_CTL_CMD_UNSUPPORTED:
2148 			default:
2149 				pr_debug("ctlfd: unsupported %d\n", *cmd);
2150 				break;
2151 			}
2152 			if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED ||
2153 			      *cmd == EVLIST_CTL_CMD_SNAPSHOT))
2154 				evlist__ctlfd_ack(evlist);
2155 		}
2156 	}
2157 
2158 	if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
2159 		evlist__finalize_ctlfd(evlist);
2160 	else
2161 		entries[ctlfd_pos].revents = 0;
2162 
2163 	return err;
2164 }
2165 
2166 /**
2167  * struct event_enable_time - perf record -D/--delay single time range.
2168  * @start: start of time range to enable events in milliseconds
2169  * @end: end of time range to enable events in milliseconds
2170  *
2171  * N.B. this structure is also accessed as an array of int.
2172  */
2173 struct event_enable_time {
2174 	int	start;
2175 	int	end;
2176 };
2177 
2178 static int parse_event_enable_time(const char *str, struct event_enable_time *range, bool first)
2179 {
2180 	const char *fmt = first ? "%u - %u %n" : " , %u - %u %n";
2181 	int ret, start, end, n;
2182 
2183 	ret = sscanf(str, fmt, &start, &end, &n);
2184 	if (ret != 2 || end <= start)
2185 		return -EINVAL;
2186 	if (range) {
2187 		range->start = start;
2188 		range->end = end;
2189 	}
2190 	return n;
2191 }
2192 
2193 static ssize_t parse_event_enable_times(const char *str, struct event_enable_time *range)
2194 {
2195 	int incr = !!range;
2196 	bool first = true;
2197 	ssize_t ret, cnt;
2198 
2199 	for (cnt = 0; *str; cnt++) {
2200 		ret = parse_event_enable_time(str, range, first);
2201 		if (ret < 0)
2202 			return ret;
2203 		/* Check no overlap */
2204 		if (!first && range && range->start <= range[-1].end)
2205 			return -EINVAL;
2206 		str += ret;
2207 		range += incr;
2208 		first = false;
2209 	}
2210 	return cnt;
2211 }
2212 
2213 /**
2214  * struct event_enable_timer - control structure for perf record -D/--delay.
2215  * @evlist: event list
2216  * @times: time ranges that events are enabled (N.B. this is also accessed as an
2217  *         array of int)
2218  * @times_cnt: number of time ranges
2219  * @timerfd: timer file descriptor
2220  * @pollfd_pos: position in @evlist array of file descriptors to poll (fdarray)
2221  * @times_step: current position in (int *)@times)[],
2222  *              refer event_enable_timer__process()
2223  *
2224  * Note, this structure is only used when there are time ranges, not when there
2225  * is only an initial delay.
2226  */
2227 struct event_enable_timer {
2228 	struct evlist *evlist;
2229 	struct event_enable_time *times;
2230 	size_t	times_cnt;
2231 	int	timerfd;
2232 	int	pollfd_pos;
2233 	size_t	times_step;
2234 };
2235 
2236 static int str_to_delay(const char *str)
2237 {
2238 	char *endptr;
2239 	long d;
2240 
2241 	d = strtol(str, &endptr, 10);
2242 	if (*endptr || d > INT_MAX || d < -1)
2243 		return 0;
2244 	return d;
2245 }
2246 
2247 int evlist__parse_event_enable_time(struct evlist *evlist, struct record_opts *opts,
2248 				    const char *str, int unset)
2249 {
2250 	enum fdarray_flags flags = fdarray_flag__nonfilterable | fdarray_flag__non_perf_event;
2251 	struct event_enable_timer *eet;
2252 	ssize_t times_cnt;
2253 	ssize_t ret;
2254 	int err;
2255 
2256 	if (unset)
2257 		return 0;
2258 
2259 	opts->initial_delay = str_to_delay(str);
2260 	if (opts->initial_delay)
2261 		return 0;
2262 
2263 	ret = parse_event_enable_times(str, NULL);
2264 	if (ret < 0)
2265 		return ret;
2266 
2267 	times_cnt = ret;
2268 	if (times_cnt == 0)
2269 		return -EINVAL;
2270 
2271 	eet = zalloc(sizeof(*eet));
2272 	if (!eet)
2273 		return -ENOMEM;
2274 
2275 	eet->times = calloc(times_cnt, sizeof(*eet->times));
2276 	if (!eet->times) {
2277 		err = -ENOMEM;
2278 		goto free_eet;
2279 	}
2280 
2281 	if (parse_event_enable_times(str, eet->times) != times_cnt) {
2282 		err = -EINVAL;
2283 		goto free_eet_times;
2284 	}
2285 
2286 	eet->times_cnt = times_cnt;
2287 
2288 	eet->timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
2289 	if (eet->timerfd == -1) {
2290 		err = -errno;
2291 		pr_err("timerfd_create failed: %s\n", strerror(errno));
2292 		goto free_eet_times;
2293 	}
2294 
2295 	eet->pollfd_pos = perf_evlist__add_pollfd(&evlist->core, eet->timerfd, NULL, POLLIN, flags);
2296 	if (eet->pollfd_pos < 0) {
2297 		err = eet->pollfd_pos;
2298 		goto close_timerfd;
2299 	}
2300 
2301 	eet->evlist = evlist;
2302 	evlist->eet = eet;
2303 	opts->initial_delay = eet->times[0].start;
2304 
2305 	return 0;
2306 
2307 close_timerfd:
2308 	close(eet->timerfd);
2309 free_eet_times:
2310 	free(eet->times);
2311 free_eet:
2312 	free(eet);
2313 	return err;
2314 }
2315 
2316 static int event_enable_timer__set_timer(struct event_enable_timer *eet, int ms)
2317 {
2318 	struct itimerspec its = {
2319 		.it_value.tv_sec = ms / MSEC_PER_SEC,
2320 		.it_value.tv_nsec = (ms % MSEC_PER_SEC) * NSEC_PER_MSEC,
2321 	};
2322 	int err = 0;
2323 
2324 	if (timerfd_settime(eet->timerfd, 0, &its, NULL) < 0) {
2325 		err = -errno;
2326 		pr_err("timerfd_settime failed: %s\n", strerror(errno));
2327 	}
2328 	return err;
2329 }
2330 
2331 int event_enable_timer__start(struct event_enable_timer *eet)
2332 {
2333 	int ms;
2334 
2335 	if (!eet)
2336 		return 0;
2337 
2338 	ms = eet->times[0].end - eet->times[0].start;
2339 	eet->times_step = 1;
2340 
2341 	return event_enable_timer__set_timer(eet, ms);
2342 }
2343 
2344 int event_enable_timer__process(struct event_enable_timer *eet)
2345 {
2346 	struct pollfd *entries;
2347 	short revents;
2348 
2349 	if (!eet)
2350 		return 0;
2351 
2352 	entries = eet->evlist->core.pollfd.entries;
2353 	revents = entries[eet->pollfd_pos].revents;
2354 	entries[eet->pollfd_pos].revents = 0;
2355 
2356 	if (revents & POLLIN) {
2357 		size_t step = eet->times_step;
2358 		size_t pos = step / 2;
2359 
2360 		if (step & 1) {
2361 			evlist__disable_non_dummy(eet->evlist);
2362 			pr_info(EVLIST_DISABLED_MSG);
2363 			if (pos >= eet->times_cnt - 1) {
2364 				/* Disarm timer */
2365 				event_enable_timer__set_timer(eet, 0);
2366 				return 1; /* Stop */
2367 			}
2368 		} else {
2369 			evlist__enable_non_dummy(eet->evlist);
2370 			pr_info(EVLIST_ENABLED_MSG);
2371 		}
2372 
2373 		step += 1;
2374 		pos = step / 2;
2375 
2376 		if (pos < eet->times_cnt) {
2377 			int *times = (int *)eet->times; /* Accessing 'times' as array of int */
2378 			int ms = times[step] - times[step - 1];
2379 
2380 			eet->times_step = step;
2381 			return event_enable_timer__set_timer(eet, ms);
2382 		}
2383 	}
2384 
2385 	return 0;
2386 }
2387 
2388 void event_enable_timer__exit(struct event_enable_timer **ep)
2389 {
2390 	if (!ep || !*ep)
2391 		return;
2392 	free((*ep)->times);
2393 	zfree(ep);
2394 }
2395 
2396 struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
2397 {
2398 	struct evsel *evsel;
2399 
2400 	evlist__for_each_entry(evlist, evsel) {
2401 		if (evsel->core.idx == idx)
2402 			return evsel;
2403 	}
2404 	return NULL;
2405 }
2406 
2407 int evlist__scnprintf_evsels(struct evlist *evlist, size_t size, char *bf)
2408 {
2409 	struct evsel *evsel;
2410 	int printed = 0;
2411 
2412 	evlist__for_each_entry(evlist, evsel) {
2413 		if (evsel__is_dummy_event(evsel))
2414 			continue;
2415 		if (size > (strlen(evsel__name(evsel)) + (printed ? 2 : 1))) {
2416 			printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "," : "", evsel__name(evsel));
2417 		} else {
2418 			printed += scnprintf(bf + printed, size - printed, "%s...", printed ? "," : "");
2419 			break;
2420 		}
2421 	}
2422 
2423 	return printed;
2424 }
2425 
2426 void evlist__check_mem_load_aux(struct evlist *evlist)
2427 {
2428 	struct evsel *leader, *evsel, *pos;
2429 
2430 	/*
2431 	 * For some platforms, the 'mem-loads' event is required to use
2432 	 * together with 'mem-loads-aux' within a group and 'mem-loads-aux'
2433 	 * must be the group leader. Now we disable this group before reporting
2434 	 * because 'mem-loads-aux' is just an auxiliary event. It doesn't carry
2435 	 * any valid memory load information.
2436 	 */
2437 	evlist__for_each_entry(evlist, evsel) {
2438 		leader = evsel__leader(evsel);
2439 		if (leader == evsel)
2440 			continue;
2441 
2442 		if (leader->name && strstr(leader->name, "mem-loads-aux")) {
2443 			for_each_group_evsel(pos, leader) {
2444 				evsel__set_leader(pos, pos);
2445 				pos->core.nr_members = 0;
2446 			}
2447 		}
2448 	}
2449 }
2450