xref: /linux/tools/perf/builtin-record.c (revision 55f3538c4923e9dfca132e99ebec370e8094afda)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * builtin-record.c
4  *
5  * Builtin record command: Record the profile of a workload
6  * (or a CPU, or a PID) into the perf.data output file - for
7  * later analysis via perf report.
8  */
9 #include "builtin.h"
10 
11 #include "perf.h"
12 
13 #include "util/build-id.h"
14 #include "util/util.h"
15 #include <subcmd/parse-options.h>
16 #include "util/parse-events.h"
17 #include "util/config.h"
18 
19 #include "util/callchain.h"
20 #include "util/cgroup.h"
21 #include "util/header.h"
22 #include "util/event.h"
23 #include "util/evlist.h"
24 #include "util/evsel.h"
25 #include "util/debug.h"
26 #include "util/drv_configs.h"
27 #include "util/session.h"
28 #include "util/tool.h"
29 #include "util/symbol.h"
30 #include "util/cpumap.h"
31 #include "util/thread_map.h"
32 #include "util/data.h"
33 #include "util/perf_regs.h"
34 #include "util/auxtrace.h"
35 #include "util/tsc.h"
36 #include "util/parse-branch-options.h"
37 #include "util/parse-regs-options.h"
38 #include "util/llvm-utils.h"
39 #include "util/bpf-loader.h"
40 #include "util/trigger.h"
41 #include "util/perf-hooks.h"
42 #include "util/time-utils.h"
43 #include "util/units.h"
44 #include "asm/bug.h"
45 
46 #include <errno.h>
47 #include <inttypes.h>
48 #include <poll.h>
49 #include <unistd.h>
50 #include <sched.h>
51 #include <signal.h>
52 #include <sys/mman.h>
53 #include <sys/wait.h>
54 #include <linux/time64.h>
55 
56 struct switch_output {
57 	bool		 enabled;
58 	bool		 signal;
59 	unsigned long	 size;
60 	unsigned long	 time;
61 	const char	*str;
62 	bool		 set;
63 };
64 
65 struct record {
66 	struct perf_tool	tool;
67 	struct record_opts	opts;
68 	u64			bytes_written;
69 	struct perf_data	data;
70 	struct auxtrace_record	*itr;
71 	struct perf_evlist	*evlist;
72 	struct perf_session	*session;
73 	const char		*progname;
74 	int			realtime_prio;
75 	bool			no_buildid;
76 	bool			no_buildid_set;
77 	bool			no_buildid_cache;
78 	bool			no_buildid_cache_set;
79 	bool			buildid_all;
80 	bool			timestamp_filename;
81 	bool			timestamp_boundary;
82 	struct switch_output	switch_output;
83 	unsigned long long	samples;
84 };
85 
86 static volatile int auxtrace_record__snapshot_started;
87 static DEFINE_TRIGGER(auxtrace_snapshot_trigger);
88 static DEFINE_TRIGGER(switch_output_trigger);
89 
90 static bool switch_output_signal(struct record *rec)
91 {
92 	return rec->switch_output.signal &&
93 	       trigger_is_ready(&switch_output_trigger);
94 }
95 
96 static bool switch_output_size(struct record *rec)
97 {
98 	return rec->switch_output.size &&
99 	       trigger_is_ready(&switch_output_trigger) &&
100 	       (rec->bytes_written >= rec->switch_output.size);
101 }
102 
103 static bool switch_output_time(struct record *rec)
104 {
105 	return rec->switch_output.time &&
106 	       trigger_is_ready(&switch_output_trigger);
107 }
108 
109 static int record__write(struct record *rec, void *bf, size_t size)
110 {
111 	if (perf_data__write(rec->session->data, bf, size) < 0) {
112 		pr_err("failed to write perf data, error: %m\n");
113 		return -1;
114 	}
115 
116 	rec->bytes_written += size;
117 
118 	if (switch_output_size(rec))
119 		trigger_hit(&switch_output_trigger);
120 
121 	return 0;
122 }
123 
124 static int process_synthesized_event(struct perf_tool *tool,
125 				     union perf_event *event,
126 				     struct perf_sample *sample __maybe_unused,
127 				     struct machine *machine __maybe_unused)
128 {
129 	struct record *rec = container_of(tool, struct record, tool);
130 	return record__write(rec, event, event->header.size);
131 }
132 
133 static int record__pushfn(void *to, void *bf, size_t size)
134 {
135 	struct record *rec = to;
136 
137 	rec->samples++;
138 	return record__write(rec, bf, size);
139 }
140 
141 static volatile int done;
142 static volatile int signr = -1;
143 static volatile int child_finished;
144 
145 static void sig_handler(int sig)
146 {
147 	if (sig == SIGCHLD)
148 		child_finished = 1;
149 	else
150 		signr = sig;
151 
152 	done = 1;
153 }
154 
155 static void sigsegv_handler(int sig)
156 {
157 	perf_hooks__recover();
158 	sighandler_dump_stack(sig);
159 }
160 
161 static void record__sig_exit(void)
162 {
163 	if (signr == -1)
164 		return;
165 
166 	signal(signr, SIG_DFL);
167 	raise(signr);
168 }
169 
170 #ifdef HAVE_AUXTRACE_SUPPORT
171 
172 static int record__process_auxtrace(struct perf_tool *tool,
173 				    union perf_event *event, void *data1,
174 				    size_t len1, void *data2, size_t len2)
175 {
176 	struct record *rec = container_of(tool, struct record, tool);
177 	struct perf_data *data = &rec->data;
178 	size_t padding;
179 	u8 pad[8] = {0};
180 
181 	if (!perf_data__is_pipe(data)) {
182 		off_t file_offset;
183 		int fd = perf_data__fd(data);
184 		int err;
185 
186 		file_offset = lseek(fd, 0, SEEK_CUR);
187 		if (file_offset == -1)
188 			return -1;
189 		err = auxtrace_index__auxtrace_event(&rec->session->auxtrace_index,
190 						     event, file_offset);
191 		if (err)
192 			return err;
193 	}
194 
195 	/* event.auxtrace.size includes padding, see __auxtrace_mmap__read() */
196 	padding = (len1 + len2) & 7;
197 	if (padding)
198 		padding = 8 - padding;
199 
200 	record__write(rec, event, event->header.size);
201 	record__write(rec, data1, len1);
202 	if (len2)
203 		record__write(rec, data2, len2);
204 	record__write(rec, &pad, padding);
205 
206 	return 0;
207 }
208 
209 static int record__auxtrace_mmap_read(struct record *rec,
210 				      struct auxtrace_mmap *mm)
211 {
212 	int ret;
213 
214 	ret = auxtrace_mmap__read(mm, rec->itr, &rec->tool,
215 				  record__process_auxtrace);
216 	if (ret < 0)
217 		return ret;
218 
219 	if (ret)
220 		rec->samples++;
221 
222 	return 0;
223 }
224 
225 static int record__auxtrace_mmap_read_snapshot(struct record *rec,
226 					       struct auxtrace_mmap *mm)
227 {
228 	int ret;
229 
230 	ret = auxtrace_mmap__read_snapshot(mm, rec->itr, &rec->tool,
231 					   record__process_auxtrace,
232 					   rec->opts.auxtrace_snapshot_size);
233 	if (ret < 0)
234 		return ret;
235 
236 	if (ret)
237 		rec->samples++;
238 
239 	return 0;
240 }
241 
242 static int record__auxtrace_read_snapshot_all(struct record *rec)
243 {
244 	int i;
245 	int rc = 0;
246 
247 	for (i = 0; i < rec->evlist->nr_mmaps; i++) {
248 		struct auxtrace_mmap *mm =
249 				&rec->evlist->mmap[i].auxtrace_mmap;
250 
251 		if (!mm->base)
252 			continue;
253 
254 		if (record__auxtrace_mmap_read_snapshot(rec, mm) != 0) {
255 			rc = -1;
256 			goto out;
257 		}
258 	}
259 out:
260 	return rc;
261 }
262 
263 static void record__read_auxtrace_snapshot(struct record *rec)
264 {
265 	pr_debug("Recording AUX area tracing snapshot\n");
266 	if (record__auxtrace_read_snapshot_all(rec) < 0) {
267 		trigger_error(&auxtrace_snapshot_trigger);
268 	} else {
269 		if (auxtrace_record__snapshot_finish(rec->itr))
270 			trigger_error(&auxtrace_snapshot_trigger);
271 		else
272 			trigger_ready(&auxtrace_snapshot_trigger);
273 	}
274 }
275 
276 #else
277 
278 static inline
279 int record__auxtrace_mmap_read(struct record *rec __maybe_unused,
280 			       struct auxtrace_mmap *mm __maybe_unused)
281 {
282 	return 0;
283 }
284 
285 static inline
286 void record__read_auxtrace_snapshot(struct record *rec __maybe_unused)
287 {
288 }
289 
290 static inline
291 int auxtrace_record__snapshot_start(struct auxtrace_record *itr __maybe_unused)
292 {
293 	return 0;
294 }
295 
296 #endif
297 
298 static int record__mmap_evlist(struct record *rec,
299 			       struct perf_evlist *evlist)
300 {
301 	struct record_opts *opts = &rec->opts;
302 	char msg[512];
303 
304 	if (perf_evlist__mmap_ex(evlist, opts->mmap_pages,
305 				 opts->auxtrace_mmap_pages,
306 				 opts->auxtrace_snapshot_mode) < 0) {
307 		if (errno == EPERM) {
308 			pr_err("Permission error mapping pages.\n"
309 			       "Consider increasing "
310 			       "/proc/sys/kernel/perf_event_mlock_kb,\n"
311 			       "or try again with a smaller value of -m/--mmap_pages.\n"
312 			       "(current value: %u,%u)\n",
313 			       opts->mmap_pages, opts->auxtrace_mmap_pages);
314 			return -errno;
315 		} else {
316 			pr_err("failed to mmap with %d (%s)\n", errno,
317 				str_error_r(errno, msg, sizeof(msg)));
318 			if (errno)
319 				return -errno;
320 			else
321 				return -EINVAL;
322 		}
323 	}
324 	return 0;
325 }
326 
327 static int record__mmap(struct record *rec)
328 {
329 	return record__mmap_evlist(rec, rec->evlist);
330 }
331 
332 static int record__open(struct record *rec)
333 {
334 	char msg[BUFSIZ];
335 	struct perf_evsel *pos;
336 	struct perf_evlist *evlist = rec->evlist;
337 	struct perf_session *session = rec->session;
338 	struct record_opts *opts = &rec->opts;
339 	struct perf_evsel_config_term *err_term;
340 	int rc = 0;
341 
342 	/*
343 	 * For initial_delay we need to add a dummy event so that we can track
344 	 * PERF_RECORD_MMAP while we wait for the initial delay to enable the
345 	 * real events, the ones asked by the user.
346 	 */
347 	if (opts->initial_delay) {
348 		if (perf_evlist__add_dummy(evlist))
349 			return -ENOMEM;
350 
351 		pos = perf_evlist__first(evlist);
352 		pos->tracking = 0;
353 		pos = perf_evlist__last(evlist);
354 		pos->tracking = 1;
355 		pos->attr.enable_on_exec = 1;
356 	}
357 
358 	perf_evlist__config(evlist, opts, &callchain_param);
359 
360 	evlist__for_each_entry(evlist, pos) {
361 try_again:
362 		if (perf_evsel__open(pos, pos->cpus, pos->threads) < 0) {
363 			if (perf_evsel__fallback(pos, errno, msg, sizeof(msg))) {
364 				if (verbose > 0)
365 					ui__warning("%s\n", msg);
366 				goto try_again;
367 			}
368 
369 			rc = -errno;
370 			perf_evsel__open_strerror(pos, &opts->target,
371 						  errno, msg, sizeof(msg));
372 			ui__error("%s\n", msg);
373 			goto out;
374 		}
375 
376 		pos->supported = true;
377 	}
378 
379 	if (perf_evlist__apply_filters(evlist, &pos)) {
380 		pr_err("failed to set filter \"%s\" on event %s with %d (%s)\n",
381 			pos->filter, perf_evsel__name(pos), errno,
382 			str_error_r(errno, msg, sizeof(msg)));
383 		rc = -1;
384 		goto out;
385 	}
386 
387 	if (perf_evlist__apply_drv_configs(evlist, &pos, &err_term)) {
388 		pr_err("failed to set config \"%s\" on event %s with %d (%s)\n",
389 		      err_term->val.drv_cfg, perf_evsel__name(pos), errno,
390 		      str_error_r(errno, msg, sizeof(msg)));
391 		rc = -1;
392 		goto out;
393 	}
394 
395 	rc = record__mmap(rec);
396 	if (rc)
397 		goto out;
398 
399 	session->evlist = evlist;
400 	perf_session__set_id_hdr_size(session);
401 out:
402 	return rc;
403 }
404 
405 static int process_sample_event(struct perf_tool *tool,
406 				union perf_event *event,
407 				struct perf_sample *sample,
408 				struct perf_evsel *evsel,
409 				struct machine *machine)
410 {
411 	struct record *rec = container_of(tool, struct record, tool);
412 
413 	if (rec->evlist->first_sample_time == 0)
414 		rec->evlist->first_sample_time = sample->time;
415 
416 	rec->evlist->last_sample_time = sample->time;
417 
418 	if (rec->buildid_all)
419 		return 0;
420 
421 	rec->samples++;
422 	return build_id__mark_dso_hit(tool, event, sample, evsel, machine);
423 }
424 
425 static int process_buildids(struct record *rec)
426 {
427 	struct perf_data *data = &rec->data;
428 	struct perf_session *session = rec->session;
429 
430 	if (data->size == 0)
431 		return 0;
432 
433 	/*
434 	 * During this process, it'll load kernel map and replace the
435 	 * dso->long_name to a real pathname it found.  In this case
436 	 * we prefer the vmlinux path like
437 	 *   /lib/modules/3.16.4/build/vmlinux
438 	 *
439 	 * rather than build-id path (in debug directory).
440 	 *   $HOME/.debug/.build-id/f0/6e17aa50adf4d00b88925e03775de107611551
441 	 */
442 	symbol_conf.ignore_vmlinux_buildid = true;
443 
444 	/*
445 	 * If --buildid-all is given, it marks all DSO regardless of hits,
446 	 * so no need to process samples. But if timestamp_boundary is enabled,
447 	 * it still needs to walk on all samples to get the timestamps of
448 	 * first/last samples.
449 	 */
450 	if (rec->buildid_all && !rec->timestamp_boundary)
451 		rec->tool.sample = NULL;
452 
453 	return perf_session__process_events(session);
454 }
455 
456 static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
457 {
458 	int err;
459 	struct perf_tool *tool = data;
460 	/*
461 	 *As for guest kernel when processing subcommand record&report,
462 	 *we arrange module mmap prior to guest kernel mmap and trigger
463 	 *a preload dso because default guest module symbols are loaded
464 	 *from guest kallsyms instead of /lib/modules/XXX/XXX. This
465 	 *method is used to avoid symbol missing when the first addr is
466 	 *in module instead of in guest kernel.
467 	 */
468 	err = perf_event__synthesize_modules(tool, process_synthesized_event,
469 					     machine);
470 	if (err < 0)
471 		pr_err("Couldn't record guest kernel [%d]'s reference"
472 		       " relocation symbol.\n", machine->pid);
473 
474 	/*
475 	 * We use _stext for guest kernel because guest kernel's /proc/kallsyms
476 	 * have no _text sometimes.
477 	 */
478 	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
479 						 machine);
480 	if (err < 0)
481 		pr_err("Couldn't record guest kernel [%d]'s reference"
482 		       " relocation symbol.\n", machine->pid);
483 }
484 
485 static struct perf_event_header finished_round_event = {
486 	.size = sizeof(struct perf_event_header),
487 	.type = PERF_RECORD_FINISHED_ROUND,
488 };
489 
490 static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evlist,
491 				    bool overwrite)
492 {
493 	u64 bytes_written = rec->bytes_written;
494 	int i;
495 	int rc = 0;
496 	struct perf_mmap *maps;
497 
498 	if (!evlist)
499 		return 0;
500 
501 	maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
502 	if (!maps)
503 		return 0;
504 
505 	if (overwrite && evlist->bkw_mmap_state != BKW_MMAP_DATA_PENDING)
506 		return 0;
507 
508 	for (i = 0; i < evlist->nr_mmaps; i++) {
509 		struct auxtrace_mmap *mm = &maps[i].auxtrace_mmap;
510 
511 		if (maps[i].base) {
512 			if (perf_mmap__push(&maps[i], overwrite, rec, record__pushfn) != 0) {
513 				rc = -1;
514 				goto out;
515 			}
516 		}
517 
518 		if (mm->base && !rec->opts.auxtrace_snapshot_mode &&
519 		    record__auxtrace_mmap_read(rec, mm) != 0) {
520 			rc = -1;
521 			goto out;
522 		}
523 	}
524 
525 	/*
526 	 * Mark the round finished in case we wrote
527 	 * at least one event.
528 	 */
529 	if (bytes_written != rec->bytes_written)
530 		rc = record__write(rec, &finished_round_event, sizeof(finished_round_event));
531 
532 	if (overwrite)
533 		perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_EMPTY);
534 out:
535 	return rc;
536 }
537 
538 static int record__mmap_read_all(struct record *rec)
539 {
540 	int err;
541 
542 	err = record__mmap_read_evlist(rec, rec->evlist, false);
543 	if (err)
544 		return err;
545 
546 	return record__mmap_read_evlist(rec, rec->evlist, true);
547 }
548 
549 static void record__init_features(struct record *rec)
550 {
551 	struct perf_session *session = rec->session;
552 	int feat;
553 
554 	for (feat = HEADER_FIRST_FEATURE; feat < HEADER_LAST_FEATURE; feat++)
555 		perf_header__set_feat(&session->header, feat);
556 
557 	if (rec->no_buildid)
558 		perf_header__clear_feat(&session->header, HEADER_BUILD_ID);
559 
560 	if (!have_tracepoints(&rec->evlist->entries))
561 		perf_header__clear_feat(&session->header, HEADER_TRACING_DATA);
562 
563 	if (!rec->opts.branch_stack)
564 		perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK);
565 
566 	if (!rec->opts.full_auxtrace)
567 		perf_header__clear_feat(&session->header, HEADER_AUXTRACE);
568 
569 	perf_header__clear_feat(&session->header, HEADER_STAT);
570 }
571 
572 static void
573 record__finish_output(struct record *rec)
574 {
575 	struct perf_data *data = &rec->data;
576 	int fd = perf_data__fd(data);
577 
578 	if (data->is_pipe)
579 		return;
580 
581 	rec->session->header.data_size += rec->bytes_written;
582 	data->size = lseek(perf_data__fd(data), 0, SEEK_CUR);
583 
584 	if (!rec->no_buildid) {
585 		process_buildids(rec);
586 
587 		if (rec->buildid_all)
588 			dsos__hit_all(rec->session);
589 	}
590 	perf_session__write_header(rec->session, rec->evlist, fd, true);
591 
592 	return;
593 }
594 
595 static int record__synthesize_workload(struct record *rec, bool tail)
596 {
597 	int err;
598 	struct thread_map *thread_map;
599 
600 	if (rec->opts.tail_synthesize != tail)
601 		return 0;
602 
603 	thread_map = thread_map__new_by_tid(rec->evlist->workload.pid);
604 	if (thread_map == NULL)
605 		return -1;
606 
607 	err = perf_event__synthesize_thread_map(&rec->tool, thread_map,
608 						 process_synthesized_event,
609 						 &rec->session->machines.host,
610 						 rec->opts.sample_address,
611 						 rec->opts.proc_map_timeout);
612 	thread_map__put(thread_map);
613 	return err;
614 }
615 
616 static int record__synthesize(struct record *rec, bool tail);
617 
618 static int
619 record__switch_output(struct record *rec, bool at_exit)
620 {
621 	struct perf_data *data = &rec->data;
622 	int fd, err;
623 
624 	/* Same Size:      "2015122520103046"*/
625 	char timestamp[] = "InvalidTimestamp";
626 
627 	record__synthesize(rec, true);
628 	if (target__none(&rec->opts.target))
629 		record__synthesize_workload(rec, true);
630 
631 	rec->samples = 0;
632 	record__finish_output(rec);
633 	err = fetch_current_timestamp(timestamp, sizeof(timestamp));
634 	if (err) {
635 		pr_err("Failed to get current timestamp\n");
636 		return -EINVAL;
637 	}
638 
639 	fd = perf_data__switch(data, timestamp,
640 				    rec->session->header.data_offset,
641 				    at_exit);
642 	if (fd >= 0 && !at_exit) {
643 		rec->bytes_written = 0;
644 		rec->session->header.data_size = 0;
645 	}
646 
647 	if (!quiet)
648 		fprintf(stderr, "[ perf record: Dump %s.%s ]\n",
649 			data->file.path, timestamp);
650 
651 	/* Output tracking events */
652 	if (!at_exit) {
653 		record__synthesize(rec, false);
654 
655 		/*
656 		 * In 'perf record --switch-output' without -a,
657 		 * record__synthesize() in record__switch_output() won't
658 		 * generate tracking events because there's no thread_map
659 		 * in evlist. Which causes newly created perf.data doesn't
660 		 * contain map and comm information.
661 		 * Create a fake thread_map and directly call
662 		 * perf_event__synthesize_thread_map() for those events.
663 		 */
664 		if (target__none(&rec->opts.target))
665 			record__synthesize_workload(rec, false);
666 	}
667 	return fd;
668 }
669 
670 static volatile int workload_exec_errno;
671 
672 /*
673  * perf_evlist__prepare_workload will send a SIGUSR1
674  * if the fork fails, since we asked by setting its
675  * want_signal to true.
676  */
677 static void workload_exec_failed_signal(int signo __maybe_unused,
678 					siginfo_t *info,
679 					void *ucontext __maybe_unused)
680 {
681 	workload_exec_errno = info->si_value.sival_int;
682 	done = 1;
683 	child_finished = 1;
684 }
685 
686 static void snapshot_sig_handler(int sig);
687 static void alarm_sig_handler(int sig);
688 
689 int __weak
690 perf_event__synth_time_conv(const struct perf_event_mmap_page *pc __maybe_unused,
691 			    struct perf_tool *tool __maybe_unused,
692 			    perf_event__handler_t process __maybe_unused,
693 			    struct machine *machine __maybe_unused)
694 {
695 	return 0;
696 }
697 
698 static const struct perf_event_mmap_page *
699 perf_evlist__pick_pc(struct perf_evlist *evlist)
700 {
701 	if (evlist) {
702 		if (evlist->mmap && evlist->mmap[0].base)
703 			return evlist->mmap[0].base;
704 		if (evlist->overwrite_mmap && evlist->overwrite_mmap[0].base)
705 			return evlist->overwrite_mmap[0].base;
706 	}
707 	return NULL;
708 }
709 
710 static const struct perf_event_mmap_page *record__pick_pc(struct record *rec)
711 {
712 	const struct perf_event_mmap_page *pc;
713 
714 	pc = perf_evlist__pick_pc(rec->evlist);
715 	if (pc)
716 		return pc;
717 	return NULL;
718 }
719 
720 static int record__synthesize(struct record *rec, bool tail)
721 {
722 	struct perf_session *session = rec->session;
723 	struct machine *machine = &session->machines.host;
724 	struct perf_data *data = &rec->data;
725 	struct record_opts *opts = &rec->opts;
726 	struct perf_tool *tool = &rec->tool;
727 	int fd = perf_data__fd(data);
728 	int err = 0;
729 
730 	if (rec->opts.tail_synthesize != tail)
731 		return 0;
732 
733 	if (data->is_pipe) {
734 		err = perf_event__synthesize_features(
735 			tool, session, rec->evlist, process_synthesized_event);
736 		if (err < 0) {
737 			pr_err("Couldn't synthesize features.\n");
738 			return err;
739 		}
740 
741 		err = perf_event__synthesize_attrs(tool, session,
742 						   process_synthesized_event);
743 		if (err < 0) {
744 			pr_err("Couldn't synthesize attrs.\n");
745 			goto out;
746 		}
747 
748 		if (have_tracepoints(&rec->evlist->entries)) {
749 			/*
750 			 * FIXME err <= 0 here actually means that
751 			 * there were no tracepoints so its not really
752 			 * an error, just that we don't need to
753 			 * synthesize anything.  We really have to
754 			 * return this more properly and also
755 			 * propagate errors that now are calling die()
756 			 */
757 			err = perf_event__synthesize_tracing_data(tool,	fd, rec->evlist,
758 								  process_synthesized_event);
759 			if (err <= 0) {
760 				pr_err("Couldn't record tracing data.\n");
761 				goto out;
762 			}
763 			rec->bytes_written += err;
764 		}
765 	}
766 
767 	err = perf_event__synth_time_conv(record__pick_pc(rec), tool,
768 					  process_synthesized_event, machine);
769 	if (err)
770 		goto out;
771 
772 	if (rec->opts.full_auxtrace) {
773 		err = perf_event__synthesize_auxtrace_info(rec->itr, tool,
774 					session, process_synthesized_event);
775 		if (err)
776 			goto out;
777 	}
778 
779 	if (!perf_evlist__exclude_kernel(rec->evlist)) {
780 		err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
781 							 machine);
782 		WARN_ONCE(err < 0, "Couldn't record kernel reference relocation symbol\n"
783 				   "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
784 				   "Check /proc/kallsyms permission or run as root.\n");
785 
786 		err = perf_event__synthesize_modules(tool, process_synthesized_event,
787 						     machine);
788 		WARN_ONCE(err < 0, "Couldn't record kernel module information.\n"
789 				   "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
790 				   "Check /proc/modules permission or run as root.\n");
791 	}
792 
793 	if (perf_guest) {
794 		machines__process_guests(&session->machines,
795 					 perf_event__synthesize_guest_os, tool);
796 	}
797 
798 	err = perf_event__synthesize_extra_attr(&rec->tool,
799 						rec->evlist,
800 						process_synthesized_event,
801 						data->is_pipe);
802 	if (err)
803 		goto out;
804 
805 	err = perf_event__synthesize_thread_map2(&rec->tool, rec->evlist->threads,
806 						 process_synthesized_event,
807 						NULL);
808 	if (err < 0) {
809 		pr_err("Couldn't synthesize thread map.\n");
810 		return err;
811 	}
812 
813 	err = perf_event__synthesize_cpu_map(&rec->tool, rec->evlist->cpus,
814 					     process_synthesized_event, NULL);
815 	if (err < 0) {
816 		pr_err("Couldn't synthesize cpu map.\n");
817 		return err;
818 	}
819 
820 	err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads,
821 					    process_synthesized_event, opts->sample_address,
822 					    opts->proc_map_timeout, 1);
823 out:
824 	return err;
825 }
826 
827 static int __cmd_record(struct record *rec, int argc, const char **argv)
828 {
829 	int err;
830 	int status = 0;
831 	unsigned long waking = 0;
832 	const bool forks = argc > 0;
833 	struct machine *machine;
834 	struct perf_tool *tool = &rec->tool;
835 	struct record_opts *opts = &rec->opts;
836 	struct perf_data *data = &rec->data;
837 	struct perf_session *session;
838 	bool disabled = false, draining = false;
839 	int fd;
840 
841 	rec->progname = argv[0];
842 
843 	atexit(record__sig_exit);
844 	signal(SIGCHLD, sig_handler);
845 	signal(SIGINT, sig_handler);
846 	signal(SIGTERM, sig_handler);
847 	signal(SIGSEGV, sigsegv_handler);
848 
849 	if (rec->opts.record_namespaces)
850 		tool->namespace_events = true;
851 
852 	if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.enabled) {
853 		signal(SIGUSR2, snapshot_sig_handler);
854 		if (rec->opts.auxtrace_snapshot_mode)
855 			trigger_on(&auxtrace_snapshot_trigger);
856 		if (rec->switch_output.enabled)
857 			trigger_on(&switch_output_trigger);
858 	} else {
859 		signal(SIGUSR2, SIG_IGN);
860 	}
861 
862 	session = perf_session__new(data, false, tool);
863 	if (session == NULL) {
864 		pr_err("Perf session creation failed.\n");
865 		return -1;
866 	}
867 
868 	fd = perf_data__fd(data);
869 	rec->session = session;
870 
871 	record__init_features(rec);
872 
873 	if (forks) {
874 		err = perf_evlist__prepare_workload(rec->evlist, &opts->target,
875 						    argv, data->is_pipe,
876 						    workload_exec_failed_signal);
877 		if (err < 0) {
878 			pr_err("Couldn't run the workload!\n");
879 			status = err;
880 			goto out_delete_session;
881 		}
882 	}
883 
884 	if (record__open(rec) != 0) {
885 		err = -1;
886 		goto out_child;
887 	}
888 
889 	err = bpf__apply_obj_config();
890 	if (err) {
891 		char errbuf[BUFSIZ];
892 
893 		bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
894 		pr_err("ERROR: Apply config to BPF failed: %s\n",
895 			 errbuf);
896 		goto out_child;
897 	}
898 
899 	/*
900 	 * Normally perf_session__new would do this, but it doesn't have the
901 	 * evlist.
902 	 */
903 	if (rec->tool.ordered_events && !perf_evlist__sample_id_all(rec->evlist)) {
904 		pr_warning("WARNING: No sample_id_all support, falling back to unordered processing\n");
905 		rec->tool.ordered_events = false;
906 	}
907 
908 	if (!rec->evlist->nr_groups)
909 		perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);
910 
911 	if (data->is_pipe) {
912 		err = perf_header__write_pipe(fd);
913 		if (err < 0)
914 			goto out_child;
915 	} else {
916 		err = perf_session__write_header(session, rec->evlist, fd, false);
917 		if (err < 0)
918 			goto out_child;
919 	}
920 
921 	if (!rec->no_buildid
922 	    && !perf_header__has_feat(&session->header, HEADER_BUILD_ID)) {
923 		pr_err("Couldn't generate buildids. "
924 		       "Use --no-buildid to profile anyway.\n");
925 		err = -1;
926 		goto out_child;
927 	}
928 
929 	machine = &session->machines.host;
930 
931 	err = record__synthesize(rec, false);
932 	if (err < 0)
933 		goto out_child;
934 
935 	if (rec->realtime_prio) {
936 		struct sched_param param;
937 
938 		param.sched_priority = rec->realtime_prio;
939 		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
940 			pr_err("Could not set realtime priority.\n");
941 			err = -1;
942 			goto out_child;
943 		}
944 	}
945 
946 	/*
947 	 * When perf is starting the traced process, all the events
948 	 * (apart from group members) have enable_on_exec=1 set,
949 	 * so don't spoil it by prematurely enabling them.
950 	 */
951 	if (!target__none(&opts->target) && !opts->initial_delay)
952 		perf_evlist__enable(rec->evlist);
953 
954 	/*
955 	 * Let the child rip
956 	 */
957 	if (forks) {
958 		union perf_event *event;
959 		pid_t tgid;
960 
961 		event = malloc(sizeof(event->comm) + machine->id_hdr_size);
962 		if (event == NULL) {
963 			err = -ENOMEM;
964 			goto out_child;
965 		}
966 
967 		/*
968 		 * Some H/W events are generated before COMM event
969 		 * which is emitted during exec(), so perf script
970 		 * cannot see a correct process name for those events.
971 		 * Synthesize COMM event to prevent it.
972 		 */
973 		tgid = perf_event__synthesize_comm(tool, event,
974 						   rec->evlist->workload.pid,
975 						   process_synthesized_event,
976 						   machine);
977 		free(event);
978 
979 		if (tgid == -1)
980 			goto out_child;
981 
982 		event = malloc(sizeof(event->namespaces) +
983 			       (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
984 			       machine->id_hdr_size);
985 		if (event == NULL) {
986 			err = -ENOMEM;
987 			goto out_child;
988 		}
989 
990 		/*
991 		 * Synthesize NAMESPACES event for the command specified.
992 		 */
993 		perf_event__synthesize_namespaces(tool, event,
994 						  rec->evlist->workload.pid,
995 						  tgid, process_synthesized_event,
996 						  machine);
997 		free(event);
998 
999 		perf_evlist__start_workload(rec->evlist);
1000 	}
1001 
1002 	if (opts->initial_delay) {
1003 		usleep(opts->initial_delay * USEC_PER_MSEC);
1004 		perf_evlist__enable(rec->evlist);
1005 	}
1006 
1007 	trigger_ready(&auxtrace_snapshot_trigger);
1008 	trigger_ready(&switch_output_trigger);
1009 	perf_hooks__invoke_record_start();
1010 	for (;;) {
1011 		unsigned long long hits = rec->samples;
1012 
1013 		/*
1014 		 * rec->evlist->bkw_mmap_state is possible to be
1015 		 * BKW_MMAP_EMPTY here: when done == true and
1016 		 * hits != rec->samples in previous round.
1017 		 *
1018 		 * perf_evlist__toggle_bkw_mmap ensure we never
1019 		 * convert BKW_MMAP_EMPTY to BKW_MMAP_DATA_PENDING.
1020 		 */
1021 		if (trigger_is_hit(&switch_output_trigger) || done || draining)
1022 			perf_evlist__toggle_bkw_mmap(rec->evlist, BKW_MMAP_DATA_PENDING);
1023 
1024 		if (record__mmap_read_all(rec) < 0) {
1025 			trigger_error(&auxtrace_snapshot_trigger);
1026 			trigger_error(&switch_output_trigger);
1027 			err = -1;
1028 			goto out_child;
1029 		}
1030 
1031 		if (auxtrace_record__snapshot_started) {
1032 			auxtrace_record__snapshot_started = 0;
1033 			if (!trigger_is_error(&auxtrace_snapshot_trigger))
1034 				record__read_auxtrace_snapshot(rec);
1035 			if (trigger_is_error(&auxtrace_snapshot_trigger)) {
1036 				pr_err("AUX area tracing snapshot failed\n");
1037 				err = -1;
1038 				goto out_child;
1039 			}
1040 		}
1041 
1042 		if (trigger_is_hit(&switch_output_trigger)) {
1043 			/*
1044 			 * If switch_output_trigger is hit, the data in
1045 			 * overwritable ring buffer should have been collected,
1046 			 * so bkw_mmap_state should be set to BKW_MMAP_EMPTY.
1047 			 *
1048 			 * If SIGUSR2 raise after or during record__mmap_read_all(),
1049 			 * record__mmap_read_all() didn't collect data from
1050 			 * overwritable ring buffer. Read again.
1051 			 */
1052 			if (rec->evlist->bkw_mmap_state == BKW_MMAP_RUNNING)
1053 				continue;
1054 			trigger_ready(&switch_output_trigger);
1055 
1056 			/*
1057 			 * Reenable events in overwrite ring buffer after
1058 			 * record__mmap_read_all(): we should have collected
1059 			 * data from it.
1060 			 */
1061 			perf_evlist__toggle_bkw_mmap(rec->evlist, BKW_MMAP_RUNNING);
1062 
1063 			if (!quiet)
1064 				fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n",
1065 					waking);
1066 			waking = 0;
1067 			fd = record__switch_output(rec, false);
1068 			if (fd < 0) {
1069 				pr_err("Failed to switch to new file\n");
1070 				trigger_error(&switch_output_trigger);
1071 				err = fd;
1072 				goto out_child;
1073 			}
1074 
1075 			/* re-arm the alarm */
1076 			if (rec->switch_output.time)
1077 				alarm(rec->switch_output.time);
1078 		}
1079 
1080 		if (hits == rec->samples) {
1081 			if (done || draining)
1082 				break;
1083 			err = perf_evlist__poll(rec->evlist, -1);
1084 			/*
1085 			 * Propagate error, only if there's any. Ignore positive
1086 			 * number of returned events and interrupt error.
1087 			 */
1088 			if (err > 0 || (err < 0 && errno == EINTR))
1089 				err = 0;
1090 			waking++;
1091 
1092 			if (perf_evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
1093 				draining = true;
1094 		}
1095 
1096 		/*
1097 		 * When perf is starting the traced process, at the end events
1098 		 * die with the process and we wait for that. Thus no need to
1099 		 * disable events in this case.
1100 		 */
1101 		if (done && !disabled && !target__none(&opts->target)) {
1102 			trigger_off(&auxtrace_snapshot_trigger);
1103 			perf_evlist__disable(rec->evlist);
1104 			disabled = true;
1105 		}
1106 	}
1107 	trigger_off(&auxtrace_snapshot_trigger);
1108 	trigger_off(&switch_output_trigger);
1109 
1110 	if (forks && workload_exec_errno) {
1111 		char msg[STRERR_BUFSIZE];
1112 		const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg));
1113 		pr_err("Workload failed: %s\n", emsg);
1114 		err = -1;
1115 		goto out_child;
1116 	}
1117 
1118 	if (!quiet)
1119 		fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
1120 
1121 	if (target__none(&rec->opts.target))
1122 		record__synthesize_workload(rec, true);
1123 
1124 out_child:
1125 	if (forks) {
1126 		int exit_status;
1127 
1128 		if (!child_finished)
1129 			kill(rec->evlist->workload.pid, SIGTERM);
1130 
1131 		wait(&exit_status);
1132 
1133 		if (err < 0)
1134 			status = err;
1135 		else if (WIFEXITED(exit_status))
1136 			status = WEXITSTATUS(exit_status);
1137 		else if (WIFSIGNALED(exit_status))
1138 			signr = WTERMSIG(exit_status);
1139 	} else
1140 		status = err;
1141 
1142 	record__synthesize(rec, true);
1143 	/* this will be recalculated during process_buildids() */
1144 	rec->samples = 0;
1145 
1146 	if (!err) {
1147 		if (!rec->timestamp_filename) {
1148 			record__finish_output(rec);
1149 		} else {
1150 			fd = record__switch_output(rec, true);
1151 			if (fd < 0) {
1152 				status = fd;
1153 				goto out_delete_session;
1154 			}
1155 		}
1156 	}
1157 
1158 	perf_hooks__invoke_record_end();
1159 
1160 	if (!err && !quiet) {
1161 		char samples[128];
1162 		const char *postfix = rec->timestamp_filename ?
1163 					".<timestamp>" : "";
1164 
1165 		if (rec->samples && !rec->opts.full_auxtrace)
1166 			scnprintf(samples, sizeof(samples),
1167 				  " (%" PRIu64 " samples)", rec->samples);
1168 		else
1169 			samples[0] = '\0';
1170 
1171 		fprintf(stderr,	"[ perf record: Captured and wrote %.3f MB %s%s%s ]\n",
1172 			perf_data__size(data) / 1024.0 / 1024.0,
1173 			data->file.path, postfix, samples);
1174 	}
1175 
1176 out_delete_session:
1177 	perf_session__delete(session);
1178 	return status;
1179 }
1180 
1181 static void callchain_debug(struct callchain_param *callchain)
1182 {
1183 	static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF", "LBR" };
1184 
1185 	pr_debug("callchain: type %s\n", str[callchain->record_mode]);
1186 
1187 	if (callchain->record_mode == CALLCHAIN_DWARF)
1188 		pr_debug("callchain: stack dump size %d\n",
1189 			 callchain->dump_size);
1190 }
1191 
1192 int record_opts__parse_callchain(struct record_opts *record,
1193 				 struct callchain_param *callchain,
1194 				 const char *arg, bool unset)
1195 {
1196 	int ret;
1197 	callchain->enabled = !unset;
1198 
1199 	/* --no-call-graph */
1200 	if (unset) {
1201 		callchain->record_mode = CALLCHAIN_NONE;
1202 		pr_debug("callchain: disabled\n");
1203 		return 0;
1204 	}
1205 
1206 	ret = parse_callchain_record_opt(arg, callchain);
1207 	if (!ret) {
1208 		/* Enable data address sampling for DWARF unwind. */
1209 		if (callchain->record_mode == CALLCHAIN_DWARF)
1210 			record->sample_address = true;
1211 		callchain_debug(callchain);
1212 	}
1213 
1214 	return ret;
1215 }
1216 
1217 int record_parse_callchain_opt(const struct option *opt,
1218 			       const char *arg,
1219 			       int unset)
1220 {
1221 	return record_opts__parse_callchain(opt->value, &callchain_param, arg, unset);
1222 }
1223 
1224 int record_callchain_opt(const struct option *opt,
1225 			 const char *arg __maybe_unused,
1226 			 int unset __maybe_unused)
1227 {
1228 	struct callchain_param *callchain = opt->value;
1229 
1230 	callchain->enabled = true;
1231 
1232 	if (callchain->record_mode == CALLCHAIN_NONE)
1233 		callchain->record_mode = CALLCHAIN_FP;
1234 
1235 	callchain_debug(callchain);
1236 	return 0;
1237 }
1238 
1239 static int perf_record_config(const char *var, const char *value, void *cb)
1240 {
1241 	struct record *rec = cb;
1242 
1243 	if (!strcmp(var, "record.build-id")) {
1244 		if (!strcmp(value, "cache"))
1245 			rec->no_buildid_cache = false;
1246 		else if (!strcmp(value, "no-cache"))
1247 			rec->no_buildid_cache = true;
1248 		else if (!strcmp(value, "skip"))
1249 			rec->no_buildid = true;
1250 		else
1251 			return -1;
1252 		return 0;
1253 	}
1254 	if (!strcmp(var, "record.call-graph"))
1255 		var = "call-graph.record-mode"; /* fall-through */
1256 
1257 	return perf_default_config(var, value, cb);
1258 }
1259 
1260 struct clockid_map {
1261 	const char *name;
1262 	int clockid;
1263 };
1264 
1265 #define CLOCKID_MAP(n, c)	\
1266 	{ .name = n, .clockid = (c), }
1267 
1268 #define CLOCKID_END	{ .name = NULL, }
1269 
1270 
1271 /*
1272  * Add the missing ones, we need to build on many distros...
1273  */
1274 #ifndef CLOCK_MONOTONIC_RAW
1275 #define CLOCK_MONOTONIC_RAW 4
1276 #endif
1277 #ifndef CLOCK_BOOTTIME
1278 #define CLOCK_BOOTTIME 7
1279 #endif
1280 #ifndef CLOCK_TAI
1281 #define CLOCK_TAI 11
1282 #endif
1283 
1284 static const struct clockid_map clockids[] = {
1285 	/* available for all events, NMI safe */
1286 	CLOCKID_MAP("monotonic", CLOCK_MONOTONIC),
1287 	CLOCKID_MAP("monotonic_raw", CLOCK_MONOTONIC_RAW),
1288 
1289 	/* available for some events */
1290 	CLOCKID_MAP("realtime", CLOCK_REALTIME),
1291 	CLOCKID_MAP("boottime", CLOCK_BOOTTIME),
1292 	CLOCKID_MAP("tai", CLOCK_TAI),
1293 
1294 	/* available for the lazy */
1295 	CLOCKID_MAP("mono", CLOCK_MONOTONIC),
1296 	CLOCKID_MAP("raw", CLOCK_MONOTONIC_RAW),
1297 	CLOCKID_MAP("real", CLOCK_REALTIME),
1298 	CLOCKID_MAP("boot", CLOCK_BOOTTIME),
1299 
1300 	CLOCKID_END,
1301 };
1302 
1303 static int parse_clockid(const struct option *opt, const char *str, int unset)
1304 {
1305 	struct record_opts *opts = (struct record_opts *)opt->value;
1306 	const struct clockid_map *cm;
1307 	const char *ostr = str;
1308 
1309 	if (unset) {
1310 		opts->use_clockid = 0;
1311 		return 0;
1312 	}
1313 
1314 	/* no arg passed */
1315 	if (!str)
1316 		return 0;
1317 
1318 	/* no setting it twice */
1319 	if (opts->use_clockid)
1320 		return -1;
1321 
1322 	opts->use_clockid = true;
1323 
1324 	/* if its a number, we're done */
1325 	if (sscanf(str, "%d", &opts->clockid) == 1)
1326 		return 0;
1327 
1328 	/* allow a "CLOCK_" prefix to the name */
1329 	if (!strncasecmp(str, "CLOCK_", 6))
1330 		str += 6;
1331 
1332 	for (cm = clockids; cm->name; cm++) {
1333 		if (!strcasecmp(str, cm->name)) {
1334 			opts->clockid = cm->clockid;
1335 			return 0;
1336 		}
1337 	}
1338 
1339 	opts->use_clockid = false;
1340 	ui__warning("unknown clockid %s, check man page\n", ostr);
1341 	return -1;
1342 }
1343 
1344 static int record__parse_mmap_pages(const struct option *opt,
1345 				    const char *str,
1346 				    int unset __maybe_unused)
1347 {
1348 	struct record_opts *opts = opt->value;
1349 	char *s, *p;
1350 	unsigned int mmap_pages;
1351 	int ret;
1352 
1353 	if (!str)
1354 		return -EINVAL;
1355 
1356 	s = strdup(str);
1357 	if (!s)
1358 		return -ENOMEM;
1359 
1360 	p = strchr(s, ',');
1361 	if (p)
1362 		*p = '\0';
1363 
1364 	if (*s) {
1365 		ret = __perf_evlist__parse_mmap_pages(&mmap_pages, s);
1366 		if (ret)
1367 			goto out_free;
1368 		opts->mmap_pages = mmap_pages;
1369 	}
1370 
1371 	if (!p) {
1372 		ret = 0;
1373 		goto out_free;
1374 	}
1375 
1376 	ret = __perf_evlist__parse_mmap_pages(&mmap_pages, p + 1);
1377 	if (ret)
1378 		goto out_free;
1379 
1380 	opts->auxtrace_mmap_pages = mmap_pages;
1381 
1382 out_free:
1383 	free(s);
1384 	return ret;
1385 }
1386 
1387 static void switch_output_size_warn(struct record *rec)
1388 {
1389 	u64 wakeup_size = perf_evlist__mmap_size(rec->opts.mmap_pages);
1390 	struct switch_output *s = &rec->switch_output;
1391 
1392 	wakeup_size /= 2;
1393 
1394 	if (s->size < wakeup_size) {
1395 		char buf[100];
1396 
1397 		unit_number__scnprintf(buf, sizeof(buf), wakeup_size);
1398 		pr_warning("WARNING: switch-output data size lower than "
1399 			   "wakeup kernel buffer size (%s) "
1400 			   "expect bigger perf.data sizes\n", buf);
1401 	}
1402 }
1403 
1404 static int switch_output_setup(struct record *rec)
1405 {
1406 	struct switch_output *s = &rec->switch_output;
1407 	static struct parse_tag tags_size[] = {
1408 		{ .tag  = 'B', .mult = 1       },
1409 		{ .tag  = 'K', .mult = 1 << 10 },
1410 		{ .tag  = 'M', .mult = 1 << 20 },
1411 		{ .tag  = 'G', .mult = 1 << 30 },
1412 		{ .tag  = 0 },
1413 	};
1414 	static struct parse_tag tags_time[] = {
1415 		{ .tag  = 's', .mult = 1        },
1416 		{ .tag  = 'm', .mult = 60       },
1417 		{ .tag  = 'h', .mult = 60*60    },
1418 		{ .tag  = 'd', .mult = 60*60*24 },
1419 		{ .tag  = 0 },
1420 	};
1421 	unsigned long val;
1422 
1423 	if (!s->set)
1424 		return 0;
1425 
1426 	if (!strcmp(s->str, "signal")) {
1427 		s->signal = true;
1428 		pr_debug("switch-output with SIGUSR2 signal\n");
1429 		goto enabled;
1430 	}
1431 
1432 	val = parse_tag_value(s->str, tags_size);
1433 	if (val != (unsigned long) -1) {
1434 		s->size = val;
1435 		pr_debug("switch-output with %s size threshold\n", s->str);
1436 		goto enabled;
1437 	}
1438 
1439 	val = parse_tag_value(s->str, tags_time);
1440 	if (val != (unsigned long) -1) {
1441 		s->time = val;
1442 		pr_debug("switch-output with %s time threshold (%lu seconds)\n",
1443 			 s->str, s->time);
1444 		goto enabled;
1445 	}
1446 
1447 	return -1;
1448 
1449 enabled:
1450 	rec->timestamp_filename = true;
1451 	s->enabled              = true;
1452 
1453 	if (s->size && !rec->opts.no_buffering)
1454 		switch_output_size_warn(rec);
1455 
1456 	return 0;
1457 }
1458 
1459 static const char * const __record_usage[] = {
1460 	"perf record [<options>] [<command>]",
1461 	"perf record [<options>] -- <command> [<options>]",
1462 	NULL
1463 };
1464 const char * const *record_usage = __record_usage;
1465 
1466 /*
1467  * XXX Ideally would be local to cmd_record() and passed to a record__new
1468  * because we need to have access to it in record__exit, that is called
1469  * after cmd_record() exits, but since record_options need to be accessible to
1470  * builtin-script, leave it here.
1471  *
1472  * At least we don't ouch it in all the other functions here directly.
1473  *
1474  * Just say no to tons of global variables, sigh.
1475  */
1476 static struct record record = {
1477 	.opts = {
1478 		.sample_time	     = true,
1479 		.mmap_pages	     = UINT_MAX,
1480 		.user_freq	     = UINT_MAX,
1481 		.user_interval	     = ULLONG_MAX,
1482 		.freq		     = 4000,
1483 		.target		     = {
1484 			.uses_mmap   = true,
1485 			.default_per_cpu = true,
1486 		},
1487 		.proc_map_timeout     = 500,
1488 	},
1489 	.tool = {
1490 		.sample		= process_sample_event,
1491 		.fork		= perf_event__process_fork,
1492 		.exit		= perf_event__process_exit,
1493 		.comm		= perf_event__process_comm,
1494 		.namespaces	= perf_event__process_namespaces,
1495 		.mmap		= perf_event__process_mmap,
1496 		.mmap2		= perf_event__process_mmap2,
1497 		.ordered_events	= true,
1498 	},
1499 };
1500 
1501 const char record_callchain_help[] = CALLCHAIN_RECORD_HELP
1502 	"\n\t\t\t\tDefault: fp";
1503 
1504 static bool dry_run;
1505 
1506 /*
1507  * XXX Will stay a global variable till we fix builtin-script.c to stop messing
1508  * with it and switch to use the library functions in perf_evlist that came
1509  * from builtin-record.c, i.e. use record_opts,
1510  * perf_evlist__prepare_workload, etc instead of fork+exec'in 'perf record',
1511  * using pipes, etc.
1512  */
1513 static struct option __record_options[] = {
1514 	OPT_CALLBACK('e', "event", &record.evlist, "event",
1515 		     "event selector. use 'perf list' to list available events",
1516 		     parse_events_option),
1517 	OPT_CALLBACK(0, "filter", &record.evlist, "filter",
1518 		     "event filter", parse_filter),
1519 	OPT_CALLBACK_NOOPT(0, "exclude-perf", &record.evlist,
1520 			   NULL, "don't record events from perf itself",
1521 			   exclude_perf),
1522 	OPT_STRING('p', "pid", &record.opts.target.pid, "pid",
1523 		    "record events on existing process id"),
1524 	OPT_STRING('t', "tid", &record.opts.target.tid, "tid",
1525 		    "record events on existing thread id"),
1526 	OPT_INTEGER('r', "realtime", &record.realtime_prio,
1527 		    "collect data with this RT SCHED_FIFO priority"),
1528 	OPT_BOOLEAN(0, "no-buffering", &record.opts.no_buffering,
1529 		    "collect data without buffering"),
1530 	OPT_BOOLEAN('R', "raw-samples", &record.opts.raw_samples,
1531 		    "collect raw sample records from all opened counters"),
1532 	OPT_BOOLEAN('a', "all-cpus", &record.opts.target.system_wide,
1533 			    "system-wide collection from all CPUs"),
1534 	OPT_STRING('C', "cpu", &record.opts.target.cpu_list, "cpu",
1535 		    "list of cpus to monitor"),
1536 	OPT_U64('c', "count", &record.opts.user_interval, "event period to sample"),
1537 	OPT_STRING('o', "output", &record.data.file.path, "file",
1538 		    "output file name"),
1539 	OPT_BOOLEAN_SET('i', "no-inherit", &record.opts.no_inherit,
1540 			&record.opts.no_inherit_set,
1541 			"child tasks do not inherit counters"),
1542 	OPT_BOOLEAN(0, "tail-synthesize", &record.opts.tail_synthesize,
1543 		    "synthesize non-sample events at the end of output"),
1544 	OPT_BOOLEAN(0, "overwrite", &record.opts.overwrite, "use overwrite mode"),
1545 	OPT_UINTEGER('F', "freq", &record.opts.user_freq, "profile at this frequency"),
1546 	OPT_CALLBACK('m', "mmap-pages", &record.opts, "pages[,pages]",
1547 		     "number of mmap data pages and AUX area tracing mmap pages",
1548 		     record__parse_mmap_pages),
1549 	OPT_BOOLEAN(0, "group", &record.opts.group,
1550 		    "put the counters into a counter group"),
1551 	OPT_CALLBACK_NOOPT('g', NULL, &callchain_param,
1552 			   NULL, "enables call-graph recording" ,
1553 			   &record_callchain_opt),
1554 	OPT_CALLBACK(0, "call-graph", &record.opts,
1555 		     "record_mode[,record_size]", record_callchain_help,
1556 		     &record_parse_callchain_opt),
1557 	OPT_INCR('v', "verbose", &verbose,
1558 		    "be more verbose (show counter open errors, etc)"),
1559 	OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
1560 	OPT_BOOLEAN('s', "stat", &record.opts.inherit_stat,
1561 		    "per thread counts"),
1562 	OPT_BOOLEAN('d', "data", &record.opts.sample_address, "Record the sample addresses"),
1563 	OPT_BOOLEAN(0, "phys-data", &record.opts.sample_phys_addr,
1564 		    "Record the sample physical addresses"),
1565 	OPT_BOOLEAN(0, "sample-cpu", &record.opts.sample_cpu, "Record the sample cpu"),
1566 	OPT_BOOLEAN_SET('T', "timestamp", &record.opts.sample_time,
1567 			&record.opts.sample_time_set,
1568 			"Record the sample timestamps"),
1569 	OPT_BOOLEAN('P', "period", &record.opts.period, "Record the sample period"),
1570 	OPT_BOOLEAN('n', "no-samples", &record.opts.no_samples,
1571 		    "don't sample"),
1572 	OPT_BOOLEAN_SET('N', "no-buildid-cache", &record.no_buildid_cache,
1573 			&record.no_buildid_cache_set,
1574 			"do not update the buildid cache"),
1575 	OPT_BOOLEAN_SET('B', "no-buildid", &record.no_buildid,
1576 			&record.no_buildid_set,
1577 			"do not collect buildids in perf.data"),
1578 	OPT_CALLBACK('G', "cgroup", &record.evlist, "name",
1579 		     "monitor event in cgroup name only",
1580 		     parse_cgroups),
1581 	OPT_UINTEGER('D', "delay", &record.opts.initial_delay,
1582 		  "ms to wait before starting measurement after program start"),
1583 	OPT_STRING('u', "uid", &record.opts.target.uid_str, "user",
1584 		   "user to profile"),
1585 
1586 	OPT_CALLBACK_NOOPT('b', "branch-any", &record.opts.branch_stack,
1587 		     "branch any", "sample any taken branches",
1588 		     parse_branch_stack),
1589 
1590 	OPT_CALLBACK('j', "branch-filter", &record.opts.branch_stack,
1591 		     "branch filter mask", "branch stack filter modes",
1592 		     parse_branch_stack),
1593 	OPT_BOOLEAN('W', "weight", &record.opts.sample_weight,
1594 		    "sample by weight (on special events only)"),
1595 	OPT_BOOLEAN(0, "transaction", &record.opts.sample_transaction,
1596 		    "sample transaction flags (special events only)"),
1597 	OPT_BOOLEAN(0, "per-thread", &record.opts.target.per_thread,
1598 		    "use per-thread mmaps"),
1599 	OPT_CALLBACK_OPTARG('I', "intr-regs", &record.opts.sample_intr_regs, NULL, "any register",
1600 		    "sample selected machine registers on interrupt,"
1601 		    " use -I ? to list register names", parse_regs),
1602 	OPT_CALLBACK_OPTARG(0, "user-regs", &record.opts.sample_user_regs, NULL, "any register",
1603 		    "sample selected machine registers on interrupt,"
1604 		    " use -I ? to list register names", parse_regs),
1605 	OPT_BOOLEAN(0, "running-time", &record.opts.running_time,
1606 		    "Record running/enabled time of read (:S) events"),
1607 	OPT_CALLBACK('k', "clockid", &record.opts,
1608 	"clockid", "clockid to use for events, see clock_gettime()",
1609 	parse_clockid),
1610 	OPT_STRING_OPTARG('S', "snapshot", &record.opts.auxtrace_snapshot_opts,
1611 			  "opts", "AUX area tracing Snapshot Mode", ""),
1612 	OPT_UINTEGER(0, "proc-map-timeout", &record.opts.proc_map_timeout,
1613 			"per thread proc mmap processing timeout in ms"),
1614 	OPT_BOOLEAN(0, "namespaces", &record.opts.record_namespaces,
1615 		    "Record namespaces events"),
1616 	OPT_BOOLEAN(0, "switch-events", &record.opts.record_switch_events,
1617 		    "Record context switch events"),
1618 	OPT_BOOLEAN_FLAG(0, "all-kernel", &record.opts.all_kernel,
1619 			 "Configure all used events to run in kernel space.",
1620 			 PARSE_OPT_EXCLUSIVE),
1621 	OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
1622 			 "Configure all used events to run in user space.",
1623 			 PARSE_OPT_EXCLUSIVE),
1624 	OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
1625 		   "clang binary to use for compiling BPF scriptlets"),
1626 	OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
1627 		   "options passed to clang when compiling BPF scriptlets"),
1628 	OPT_STRING(0, "vmlinux", &symbol_conf.vmlinux_name,
1629 		   "file", "vmlinux pathname"),
1630 	OPT_BOOLEAN(0, "buildid-all", &record.buildid_all,
1631 		    "Record build-id of all DSOs regardless of hits"),
1632 	OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,
1633 		    "append timestamp to output filename"),
1634 	OPT_BOOLEAN(0, "timestamp-boundary", &record.timestamp_boundary,
1635 		    "Record timestamp boundary (time of first/last samples)"),
1636 	OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str,
1637 			  &record.switch_output.set, "signal,size,time",
1638 			  "Switch output when receive SIGUSR2 or cross size,time threshold",
1639 			  "signal"),
1640 	OPT_BOOLEAN(0, "dry-run", &dry_run,
1641 		    "Parse options then exit"),
1642 	OPT_END()
1643 };
1644 
1645 struct option *record_options = __record_options;
1646 
1647 int cmd_record(int argc, const char **argv)
1648 {
1649 	int err;
1650 	struct record *rec = &record;
1651 	char errbuf[BUFSIZ];
1652 
1653 #ifndef HAVE_LIBBPF_SUPPORT
1654 # define set_nobuild(s, l, c) set_option_nobuild(record_options, s, l, "NO_LIBBPF=1", c)
1655 	set_nobuild('\0', "clang-path", true);
1656 	set_nobuild('\0', "clang-opt", true);
1657 # undef set_nobuild
1658 #endif
1659 
1660 #ifndef HAVE_BPF_PROLOGUE
1661 # if !defined (HAVE_DWARF_SUPPORT)
1662 #  define REASON  "NO_DWARF=1"
1663 # elif !defined (HAVE_LIBBPF_SUPPORT)
1664 #  define REASON  "NO_LIBBPF=1"
1665 # else
1666 #  define REASON  "this architecture doesn't support BPF prologue"
1667 # endif
1668 # define set_nobuild(s, l, c) set_option_nobuild(record_options, s, l, REASON, c)
1669 	set_nobuild('\0', "vmlinux", true);
1670 # undef set_nobuild
1671 # undef REASON
1672 #endif
1673 
1674 	rec->evlist = perf_evlist__new();
1675 	if (rec->evlist == NULL)
1676 		return -ENOMEM;
1677 
1678 	err = perf_config(perf_record_config, rec);
1679 	if (err)
1680 		return err;
1681 
1682 	argc = parse_options(argc, argv, record_options, record_usage,
1683 			    PARSE_OPT_STOP_AT_NON_OPTION);
1684 	if (quiet)
1685 		perf_quiet_option();
1686 
1687 	/* Make system wide (-a) the default target. */
1688 	if (!argc && target__none(&rec->opts.target))
1689 		rec->opts.target.system_wide = true;
1690 
1691 	if (nr_cgroups && !rec->opts.target.system_wide) {
1692 		usage_with_options_msg(record_usage, record_options,
1693 			"cgroup monitoring only available in system-wide mode");
1694 
1695 	}
1696 	if (rec->opts.record_switch_events &&
1697 	    !perf_can_record_switch_events()) {
1698 		ui__error("kernel does not support recording context switch events\n");
1699 		parse_options_usage(record_usage, record_options, "switch-events", 0);
1700 		return -EINVAL;
1701 	}
1702 
1703 	if (switch_output_setup(rec)) {
1704 		parse_options_usage(record_usage, record_options, "switch-output", 0);
1705 		return -EINVAL;
1706 	}
1707 
1708 	if (rec->switch_output.time) {
1709 		signal(SIGALRM, alarm_sig_handler);
1710 		alarm(rec->switch_output.time);
1711 	}
1712 
1713 	if (!rec->itr) {
1714 		rec->itr = auxtrace_record__init(rec->evlist, &err);
1715 		if (err)
1716 			goto out;
1717 	}
1718 
1719 	err = auxtrace_parse_snapshot_options(rec->itr, &rec->opts,
1720 					      rec->opts.auxtrace_snapshot_opts);
1721 	if (err)
1722 		goto out;
1723 
1724 	/*
1725 	 * Allow aliases to facilitate the lookup of symbols for address
1726 	 * filters. Refer to auxtrace_parse_filters().
1727 	 */
1728 	symbol_conf.allow_aliases = true;
1729 
1730 	symbol__init(NULL);
1731 
1732 	err = auxtrace_parse_filters(rec->evlist);
1733 	if (err)
1734 		goto out;
1735 
1736 	if (dry_run)
1737 		goto out;
1738 
1739 	err = bpf__setup_stdout(rec->evlist);
1740 	if (err) {
1741 		bpf__strerror_setup_stdout(rec->evlist, err, errbuf, sizeof(errbuf));
1742 		pr_err("ERROR: Setup BPF stdout failed: %s\n",
1743 			 errbuf);
1744 		goto out;
1745 	}
1746 
1747 	err = -ENOMEM;
1748 
1749 	if (symbol_conf.kptr_restrict && !perf_evlist__exclude_kernel(rec->evlist))
1750 		pr_warning(
1751 "WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n"
1752 "check /proc/sys/kernel/kptr_restrict.\n\n"
1753 "Samples in kernel functions may not be resolved if a suitable vmlinux\n"
1754 "file is not found in the buildid cache or in the vmlinux path.\n\n"
1755 "Samples in kernel modules won't be resolved at all.\n\n"
1756 "If some relocation was applied (e.g. kexec) symbols may be misresolved\n"
1757 "even with a suitable vmlinux or kallsyms file.\n\n");
1758 
1759 	if (rec->no_buildid_cache || rec->no_buildid) {
1760 		disable_buildid_cache();
1761 	} else if (rec->switch_output.enabled) {
1762 		/*
1763 		 * In 'perf record --switch-output', disable buildid
1764 		 * generation by default to reduce data file switching
1765 		 * overhead. Still generate buildid if they are required
1766 		 * explicitly using
1767 		 *
1768 		 *  perf record --switch-output --no-no-buildid \
1769 		 *              --no-no-buildid-cache
1770 		 *
1771 		 * Following code equals to:
1772 		 *
1773 		 * if ((rec->no_buildid || !rec->no_buildid_set) &&
1774 		 *     (rec->no_buildid_cache || !rec->no_buildid_cache_set))
1775 		 *         disable_buildid_cache();
1776 		 */
1777 		bool disable = true;
1778 
1779 		if (rec->no_buildid_set && !rec->no_buildid)
1780 			disable = false;
1781 		if (rec->no_buildid_cache_set && !rec->no_buildid_cache)
1782 			disable = false;
1783 		if (disable) {
1784 			rec->no_buildid = true;
1785 			rec->no_buildid_cache = true;
1786 			disable_buildid_cache();
1787 		}
1788 	}
1789 
1790 	if (record.opts.overwrite)
1791 		record.opts.tail_synthesize = true;
1792 
1793 	if (rec->evlist->nr_entries == 0 &&
1794 	    __perf_evlist__add_default(rec->evlist, !record.opts.no_samples) < 0) {
1795 		pr_err("Not enough memory for event selector list\n");
1796 		goto out;
1797 	}
1798 
1799 	if (rec->opts.target.tid && !rec->opts.no_inherit_set)
1800 		rec->opts.no_inherit = true;
1801 
1802 	err = target__validate(&rec->opts.target);
1803 	if (err) {
1804 		target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
1805 		ui__warning("%s", errbuf);
1806 	}
1807 
1808 	err = target__parse_uid(&rec->opts.target);
1809 	if (err) {
1810 		int saved_errno = errno;
1811 
1812 		target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
1813 		ui__error("%s", errbuf);
1814 
1815 		err = -saved_errno;
1816 		goto out;
1817 	}
1818 
1819 	/* Enable ignoring missing threads when -u/-p option is defined. */
1820 	rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;
1821 
1822 	err = -ENOMEM;
1823 	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
1824 		usage_with_options(record_usage, record_options);
1825 
1826 	err = auxtrace_record__options(rec->itr, rec->evlist, &rec->opts);
1827 	if (err)
1828 		goto out;
1829 
1830 	/*
1831 	 * We take all buildids when the file contains
1832 	 * AUX area tracing data because we do not decode the
1833 	 * trace because it would take too long.
1834 	 */
1835 	if (rec->opts.full_auxtrace)
1836 		rec->buildid_all = true;
1837 
1838 	if (record_opts__config(&rec->opts)) {
1839 		err = -EINVAL;
1840 		goto out;
1841 	}
1842 
1843 	err = __cmd_record(&record, argc, argv);
1844 out:
1845 	perf_evlist__delete(rec->evlist);
1846 	symbol__exit();
1847 	auxtrace_record__free(rec->itr);
1848 	return err;
1849 }
1850 
1851 static void snapshot_sig_handler(int sig __maybe_unused)
1852 {
1853 	struct record *rec = &record;
1854 
1855 	if (trigger_is_ready(&auxtrace_snapshot_trigger)) {
1856 		trigger_hit(&auxtrace_snapshot_trigger);
1857 		auxtrace_record__snapshot_started = 1;
1858 		if (auxtrace_record__snapshot_start(record.itr))
1859 			trigger_error(&auxtrace_snapshot_trigger);
1860 	}
1861 
1862 	if (switch_output_signal(rec))
1863 		trigger_hit(&switch_output_trigger);
1864 }
1865 
1866 static void alarm_sig_handler(int sig __maybe_unused)
1867 {
1868 	struct record *rec = &record;
1869 
1870 	if (switch_output_time(rec))
1871 		trigger_hit(&switch_output_trigger);
1872 }
1873