summaryrefslogtreecommitdiffstats
path: root/tools/perf/builtin-record.c
blob: 8ce62ef7f6c387e3e23a18c51b9ec1cf82e2a189 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
/*
 * builtin-record.c
 *
 * Builtin record command: Record the profile of a workload
 * (or a CPU, or a PID) into the perf.data output file - for
 * later analysis via perf report.
 */
#include "builtin.h"

#include "perf.h"

#include "util/build-id.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"

#include "util/header.h"
#include "util/event.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/debug.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/symbol.h"
#include "util/cpumap.h"
#include "util/thread_map.h"
#include "util/data.h"

#include <unistd.h>
#include <sched.h>
#include <sys/mman.h>

#ifndef HAVE_ON_EXIT_SUPPORT
#ifndef ATEXIT_MAX
#define ATEXIT_MAX 32
#endif
static int __on_exit_count = 0;
typedef void (*on_exit_func_t) (int, void *);
static on_exit_func_t __on_exit_funcs[ATEXIT_MAX];
static void *__on_exit_args[ATEXIT_MAX];
static int __exitcode = 0;
static void __handle_on_exit_funcs(void);
static int on_exit(on_exit_func_t function, void *arg);
#define exit(x) (exit)(__exitcode = (x))

static int on_exit(on_exit_func_t function, void *arg)
{
	if (__on_exit_count == ATEXIT_MAX)
		return -ENOMEM;
	else if (__on_exit_count == 0)
		atexit(__handle_on_exit_funcs);
	__on_exit_funcs[__on_exit_count] = function;
	__on_exit_args[__on_exit_count++] = arg;
	return 0;
}

static void __handle_on_exit_funcs(void)
{
	int i;
	for (i = 0; i < __on_exit_count; i++)
		__on_exit_funcs[i] (__exitcode, __on_exit_args[i]);
}
#endif

struct record {
	struct perf_tool	tool;
	struct record_opts	opts;
	u64			bytes_written;
	struct perf_data_file	file;
	struct perf_evlist	*evlist;
	struct perf_session	*session;
	const char		*progname;
	int			realtime_prio;
	bool			no_buildid;
	bool			no_buildid_cache;
	long			samples;
};

static int record__write(struct record *rec, void *bf, size_t size)
{
	if (perf_data_file__write(rec->session->file, bf, size) < 0) {
		pr_err("failed to write perf data, error: %m\n");
		return -1;
	}

	rec->bytes_written += size;
	return 0;
}

static int process_synthesized_event(struct perf_tool *tool,
				     union perf_event *event,
				     struct perf_sample *sample __maybe_unused,
				     struct machine *machine __maybe_unused)
{
	struct record *rec = container_of(tool, struct record, tool);
	return record__write(rec, event, event->header.size);
}

static int record__mmap_read(struct record *rec, struct perf_mmap *md)
{
	unsigned int head = perf_mmap__read_head(md);
	unsigned int old = md->prev;
	unsigned char *data = md->base + page_size;
	unsigned long size;
	void *buf;
	int rc = 0;

	if (old == head)
		return 0;

	rec->samples++;

	size = head - old;

	if ((old & md->mask) + size != (head & md->mask)) {
		buf = &data[old & md->mask];
		size = md->mask + 1 - (old & md->mask);
		old += size;

		if (record__write(rec, buf, size) < 0) {
			rc = -1;
			goto out;
		}
	}

	buf = &data[old & md->mask];
	size = head - old;
	old += size;

	if (record__write(rec, buf, size) < 0) {
		rc = -1;
		goto out;
	}

	md->prev = old;
	perf_mmap__write_tail(md, old);

out:
	return rc;
}

static volatile int done = 0;
static volatile int signr = -1;
static volatile int child_finished = 0;

static void sig_handler(int sig)
{
	if (sig == SIGCHLD)
		child_finished = 1;

	done = 1;
	signr = sig;
}

static void record__sig_exit(int exit_status __maybe_unused, void *arg)
{
	struct record *rec = arg;
	int status;

	if (rec->evlist->workload.pid > 0) {
		if (!child_finished)
			kill(rec->evlist->workload.pid, SIGTERM);

		wait(&status);
		if (WIFSIGNALED(status))
			psignal(WTERMSIG(status), rec->progname);
	}

	if (signr == -1 || signr == SIGUSR1)
		return;

	signal(signr, SIG_DFL);
}

static int record__open(struct record *rec)
{
	char msg[512];
	struct perf_evsel *pos;
	struct perf_evlist *evlist = rec->evlist;
	struct perf_session *session = rec->session;
	struct record_opts *opts = &rec->opts;
	int rc = 0;

	perf_evlist__config(evlist, opts);

	evlist__for_each(evlist, pos) {
try_again:
		if (perf_evsel__open(pos, evlist->cpus, evlist->threads) < 0) {
			if (perf_evsel__fallback(pos, errno, msg, sizeof(msg))) {
				if (verbose)
					ui__warning("%s\n", msg);
				goto try_again;
			}

			rc = -errno;
			perf_evsel__open_strerror(pos, &opts->target,
						  errno, msg, sizeof(msg));
			ui__error("%s\n", msg);
			goto out;
		}
	}

	if (perf_evlist__apply_filters(evlist)) {
		error("failed to set filter with %d (%s)\n", errno,
			strerror(errno));
		rc = -1;
		goto out;
	}

	if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
		if (errno == EPERM) {
			pr_err("Permission error mapping pages.\n"
			       "Consider increasing "
			       "/proc/sys/kernel/perf_event_mlock_kb,\n"
			       "or try again with a smaller value of -m/--mmap_pages.\n"
			       "(current value: %u)\n", opts->mmap_pages);
			rc = -errno;
		} else {
			pr_err("failed to mmap with %d (%s)\n", errno, strerror(errno));
			rc = -errno;
		}
		goto out;
	}

	session->evlist = evlist;
	perf_session__set_id_hdr_size(session);
out:
	return rc;
}

static int process_buildids(struct record *rec)
{
	struct perf_data_file *file  = &rec->file;
	struct perf_session *session = rec->session;
	u64 start = session->header.data_offset;

	u64 size = lseek(file->fd, 0, SEEK_CUR);
	if (size == 0)
		return 0;

	return __perf_session__process_events(session, start,
					      size - start,
					      size, &build_id__mark_dso_hit_ops);
}

static void record__exit(int status, void *arg)
{
	struct record *rec = arg;
	struct perf_data_file *file = &rec->file;

	if (status != 0)
		return;

	if (!file->is_pipe) {
		rec->session->header.data_size += rec->bytes_written;

		if (!rec->no_buildid)
			process_buildids(rec);
		perf_session__write_header(rec->session, rec->evlist,
					   file->fd, true);
		perf_session__delete(rec->session);
		perf_evlist__delete(rec->evlist);
		symbol__exit();
	}
}

static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
{
	int err;
	struct perf_tool *tool = data;
	/*
	 *As for guest kernel when processing subcommand record&report,
	 *we arrange module mmap prior to guest kernel mmap and trigger
	 *a preload dso because default guest module symbols are loaded
	 *from guest kallsyms instead of /lib/modules/XXX/XXX. This
	 *method is used to avoid symbol missing when the first addr is
	 *in module instead of in guest kernel.
	 */
	err = perf_event__synthesize_modules(tool, process_synthesized_event,
					     machine);
	if (err < 0)
		pr_err("Couldn't record guest kernel [%d]'s reference"
		       " relocation symbol.\n", machine->pid);

	/*
	 * We use _stext for guest kernel because guest kernel's /proc/kallsyms
	 * have no _text sometimes.
	 */
	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
						 machine);
	if (err < 0)
		pr_err("Couldn't record guest kernel [%d]'s reference"
		       " relocation symbol.\n", machine->pid);
}

static struct perf_event_header finished_round_event = {
	.size = sizeof(struct perf_event_header),
	.type = PERF_RECORD_FINISHED_ROUND,
};

static int record__mmap_read_all(struct record *rec)
{
	int i;
	int rc = 0;

	for (i = 0; i < rec->evlist->nr_mmaps; i++) {
		if (rec->evlist->mmap[i].base) {
			if (record__mmap_read(rec, &rec->evlist->mmap[i]) != 0) {
				rc = -1;
				goto out;
			}
		}
	}

	if (perf_header__has_feat(&rec->session->header, HEADER_TRACING_DATA))
		rc = record__write(rec, &finished_round_event, sizeof(finished_round_event));

out:
	return rc;
}

static void record__init_features(struct record *rec)
{
	struct perf_session *session = rec->session;
	int feat;

	for (feat = HEADER_FIRST_FEATURE; feat < HEADER_LAST_FEATURE; feat++)
		perf_header__set_feat(&session->header, feat);

	if (rec->no_buildid)
		perf_header__clear_feat(&session->header, HEADER_BUILD_ID);

	if (!have_tracepoints(&rec->evlist->entries))
		perf_header__clear_feat(&session->header, HEADER_TRACING_DATA);

	if (!rec->opts.branch_stack)
		perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK);
}

static volatile int workload_exec_errno;

/*
 * perf_evlist__prepare_workload will send a SIGUSR1
 * if the fork fails, since we asked by setting its
 * want_signal to true.
 */
static void workload_exec_failed_signal(int signo, siginfo_t *info,
					void *ucontext __maybe_unused)
{
	workload_exec_errno = info->si_value.sival_int;
	done = 1;
	signr = signo;
	child_finished = 1;
}

static int __cmd_record(struct record *rec, int argc, const char **argv)
{
	int err;
	unsigned long waking = 0;
	const bool forks = argc > 0;
	struct machine *machine;
	struct perf_tool *tool = &rec->tool;
	struct record_opts *opts = &rec->opts;
	struct perf_data_file *file = &rec->file;
	struct perf_session *session;
	bool disabled = false;

	rec->progname = argv[0];

	on_exit(record__sig_exit, rec);
	signal(SIGCHLD, sig_handler);
	signal(SIGINT, sig_handler);
	signal(SIGTERM, sig_handler);

	session = perf_session__new(file, false, NULL);
	if (session == NULL) {
		pr_err("Perf session creation failed.\n");
		return -1;
	}

	rec->session = session;

	record__init_features(rec);

	if (forks) {
		err = perf_evlist__prepare_workload(rec->evlist, &opts->target,
						    argv, file->is_pipe,
						    workload_exec_failed_signal);
		if (err < 0) {
			pr_err("Couldn't run the workload!\n");
			goto out_delete_session;
		}
	}

	if (record__open(rec) != 0) {
		err = -1;
		goto out_delete_session;
	}

	if (!rec->evlist->nr_groups)
		perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);

	/*
	 * perf_session__delete(session) will be called at record__exit()
	 */
	on_exit(record__exit, rec);

	if (file->is_pipe) {
		err = perf_header__write_pipe(file->fd);
		if (err < 0)
			goto out_delete_session;
	} else {
		err = perf_session__write_header(session, rec->evlist,
						 file->fd, false);
		if (err < 0)
			goto out_delete_session;
	}

	if (!rec->no_buildid
	    && !perf_header__has_feat(&session->header, HEADER_BUILD_ID)) {
		pr_err("Couldn't generate buildids. "
		       "Use --no-buildid to profile anyway.\n");
		err = -1;
		goto out_delete_session;
	}

	machine = &session->machines.host;

	if (file->is_pipe) {
		err = perf_event__synthesize_attrs(tool, session,
						   process_synthesized_event);
		if (err < 0) {
			pr_err("Couldn't synthesize attrs.\n");
			goto out_delete_session;
		}

		if (have_tracepoints(&rec->evlist->entries)) {
			/*
			 * FIXME err <= 0 here actually means that
			 * there were no tracepoints so its not really
			 * an error, just that we don't need to
			 * synthesize anything.  We really have to
			 * return this more properly and also
			 * propagate errors that now are calling die()
			 */
			err = perf_event__synthesize_tracing_data(tool, file->fd, rec->evlist,
								  process_synthesized_event);
			if (err <= 0) {
				pr_err("Couldn't record tracing data.\n");
				goto out_delete_session;
			}
			rec->bytes_written += err;
		}
	}

	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
						 machine);
	if (err < 0)
		pr_err("Couldn't record kernel reference relocation symbol\n"
		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
		       "Check /proc/kallsyms permission or run as root.\n");

	err = perf_event__synthesize_modules(tool, process_synthesized_event,
					     machine);
	if (err < 0)
		pr_err("Couldn't record kernel module information.\n"
		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
		       "Check /proc/modules permission or run as root.\n");

	if (perf_guest) {
		machines__process_guests(&session->machines,
					 perf_event__synthesize_guest_os, tool);
	}

	err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads,
					    process_synthesized_event, opts->sample_address);
	if (err != 0)
		goto out_delete_session;

	if (rec->realtime_prio) {
		struct sched_param param;

		param.sched_priority = rec->realtime_prio;
		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
			pr_err("Could not set realtime priority.\n");
			err = -1;
			goto out_delete_session;
		}
	}

	/*
	 * When perf is starting the traced process, all the events
	 * (apart from group members) have enable_on_exec=1 set,
	 * so don't spoil it by prematurely enabling them.
	 */
	if (!target__none(&opts->target) && !opts->initial_delay)
		perf_evlist__enable(rec->evlist);

	/*
	 * Let the child rip
	 */
	if (forks)
		perf_evlist__start_workload(rec->evlist);

	if (opts->initial_delay) {
		usleep(opts->initial_delay * 1000);
		perf_evlist__enable(rec->evlist);
	}

	for (;;) {
		int hits = rec->samples;

		if (record__mmap_read_all(rec) < 0) {
			err = -1;
			goto out_delete_session;
		}

		if (hits == rec->samples) {
			if (done)
				break;
			err = poll(rec->evlist->pollfd, rec->evlist->nr_fds, -1);
			waking++;
		}

		/*
		 * When perf is starting the traced process, at the end events
		 * die with the process and we wait for that. Thus no need to
		 * disable events in this case.
		 */
		if (done && !disabled && !target__none(&opts->target)) {
			perf_evlist__disable(rec->evlist);
			disabled = true;
		}
	}

	if (forks && workload_exec_errno) {
		char msg[512];
		const char *emsg = strerror_r(workload_exec_errno, msg, sizeof(msg));
		pr_err("Workload failed: %s\n", emsg);
		err = -1;
		goto out_delete_session;
	}

	if (quiet || signr == SIGUSR1)
		return 0;

	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);

	/*
	 * Approximate RIP event size: 24 bytes.
	 */
	fprintf(stderr,
		"[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
		(double)rec->bytes_written / 1024.0 / 1024.0,
		file->path,
		rec->bytes_written / 24);

	return 0;

out_delete_session:
	perf_session__delete(session);
	return err;
}

#define BRANCH_OPT(n, m) \
	{ .name = n, .mode = (m) }

#define BRANCH_END { .name = NULL }

struct branch_mode {
	const char *name;
	int mode;
};

static const struct branch_mode branch_modes[] = {
	BRANCH_OPT("u", PERF_SAMPLE_BRANCH_USER),
	BRANCH_OPT("k", PERF_SAMPLE_BRANCH_KERNEL),
	BRANCH_OPT("hv", PERF_SAMPLE_BRANCH_HV),
	BRANCH_OPT("any", PERF_SAMPLE_BRANCH_ANY),
	BRANCH_OPT("any_call", PERF_SAMPLE_BRANCH_ANY_CALL),
	BRANCH_OPT("any_ret", PERF_SAMPLE_BRANCH_ANY_RETURN),
	BRANCH_OPT("ind_call", PERF_SAMPLE_BRANCH_IND_CALL),
	BRANCH_OPT("abort_tx", PERF_SAMPLE_BRANCH_ABORT_TX),
	BRANCH_OPT("in_tx", PERF_SAMPLE_BRANCH_IN_TX),
	BRANCH_OPT("no_tx", PERF_SAMPLE_BRANCH_NO_TX),
	BRANCH_END
};

static int
parse_branch_stack(const struct option *opt, const char *str, int unset)
{
#define ONLY_PLM \
	(PERF_SAMPLE_BRANCH_USER	|\
	 PERF_SAMPLE_BRANCH_KERNEL	|\
	 PERF_SAMPLE_BRANCH_HV)

	uint64_t *mode = (uint64_t *)opt->value;
	const struct branch_mode *br;
	char *s, *os = NULL, *p;
	int ret = -1;

	if (unset)
		return 0;

	/*
	 * cannot set it twice, -b + --branch-filter for instance
	 */
	if (*mode)
		return -1;

	/* str may be NULL in case no arg is passed to -b */
	if (str) {
		/* because str is read-only */
		s = os = strdup(str);
		if (!s)
			return -1;

		for (;;) {
			p = strchr(s, ',');
			if (p)
				*p = '\0';

			for (br = branch_modes; br->name; br++) {
				if (!strcasecmp(s, br->name))
					break;
			}
			if (!br->name) {
				ui__warning("unknown branch filter %s,"
					    " check man page\n", s);
				goto error;
			}

			*mode |= br->mode;

			if (!p)
				break;

			s = p + 1;
		}
	}
	ret = 0;

	/* default to any branch */
	if ((*mode & ~ONLY_PLM) == 0) {
		*mode = PERF_SAMPLE_BRANCH_ANY;
	}
error:
	free(os);
	return ret;
}

#ifdef HAVE_DWARF_UNWIND_SUPPORT
static int get_stack_size(char *str, unsigned long *_size)
{
	char *endptr;
	unsigned long size;
	unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));

	size = strtoul(str, &endptr, 0);

	do {
		if (*endptr)
			break;

		size = round_up(size, sizeof(u64));
		if (!size || size > max_size)
			break;

		*_size = size;
		return 0;

	} while (0);

	pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
	       max_size, str);
	return -1;
}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */

int record_parse_callchain(const char *arg, struct record_opts *opts)
{
	char *tok, *name, *saveptr = NULL;
	char *buf;
	int ret = -1;

	/* We need buffer that we know we can write to. */
	buf = malloc(strlen(arg) + 1);
	if (!buf)
		return -ENOMEM;

	strcpy(buf, arg);

	tok = strtok_r((char *)buf, ",", &saveptr);
	name = tok ? : (char *)buf;

	do {
		/* Framepointer style */
		if (!strncmp(name, "fp", sizeof("fp"))) {
			if (!strtok_r(NULL, ",", &saveptr)) {
				opts->call_graph = CALLCHAIN_FP;
				ret = 0;
			} else
				pr_err("callchain: No more arguments "
				       "needed for -g fp\n");
			break;

#ifdef HAVE_DWARF_UNWIND_SUPPORT
		/* Dwarf style */
		} else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
			const unsigned long default_stack_dump_size = 8192;

			ret = 0;
			opts->call_graph = CALLCHAIN_DWARF;
			opts->stack_dump_size = default_stack_dump_size;

			tok = strtok_r(NULL, ",", &saveptr);
			if (tok) {
				unsigned long size = 0;

				ret = get_stack_size(tok, &size);
				opts->stack_dump_size = size;
			}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
		} else {
			pr_err("callchain: Unknown --call-graph option "
			       "value: %s\n", arg);
			break;
		}

	} while (0);

	free(buf);
	return ret;
}

static void callchain_debug(struct record_opts *opts)
{
	static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF" };

	pr_debug("callchain: type %s\n", str[opts->call_graph]);

	if (opts->call_graph == CALLCHAIN_DWARF)
		pr_debug("callchain: stack dump size %d\n",
			 opts->stack_dump_size);
}

int record_parse_callchain_opt(const struct option *opt,
			       const char *arg,
			       int unset)
{
	struct record_opts *opts = opt->value;
	int ret;

	opts->call_graph_enabled = !unset;

	/* --no-call-graph */
	if (unset) {
		opts->call_graph = CALLCHAIN_NONE;
		pr_debug("callchain: disabled\n");
		return 0;
	}

	ret = record_parse_callchain(arg, opts);
	if (!ret)
		callchain_debug(opts);

	return ret;
}

int record_callchain_opt(const struct option *opt,
			 const char *arg __maybe_unused,
			 int unset __maybe_unused)
{
	struct record_opts *opts = opt->value;

	opts->call_graph_enabled = !unset;

	if (opts->call_graph == CALLCHAIN_NONE)
		opts->call_graph = CALLCHAIN_FP;

	callchain_debug(opts);
	return 0;
}

static int perf_record_config(const char *var, const char *value, void *cb)
{
	struct record *rec = cb;

	if (!strcmp(var, "record.call-graph"))
		return record_parse_callchain(value, &rec->opts);

	return perf_default_config(var, value, cb);
}

static const char * const record_usage[] = {
	"perf record [<options>] [<command>]",
	"perf record [<options>] -- <command> [<options>]",
	NULL
};

/*
 * XXX Ideally would be local to cmd_record() and passed to a record__new
 * because we need to have access to it in record__exit, that is called
 * after cmd_record() exits, but since record_options need to be accessible to
 * builtin-script, leave it here.
 *
 * At least we don't ouch it in all the other functions here directly.
 *
 * Just say no to tons of global variables, sigh.
 */
static struct record record = {
	.opts = {
		.mmap_pages	     = UINT_MAX,
		.user_freq	     = UINT_MAX,
		.user_interval	     = ULLONG_MAX,
		.freq		     = 4000,
		.target		     = {
			.uses_mmap   = true,
			.default_per_cpu = true,
		},
	},
};

#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace) recording: "

#ifdef HAVE_DWARF_UNWIND_SUPPORT
const char record_callchain_help[] = CALLCHAIN_HELP "fp dwarf";
#else
const char record_callchain_help[] = CALLCHAIN_HELP "fp";
#endif

/*
 * XXX Will stay a global variable till we fix builtin-script.c to stop messing
 * with it and switch to use the library functions in perf_evlist that came
 * from builtin-record.c, i.e. use record_opts,
 * perf_evlist__prepare_workload, etc instead of fork+exec'in 'perf record',
 * using pipes, etc.
 */
const struct option record_options[] = {
	OPT_CALLBACK('e', "event", &record.evlist, "event",
		     "event selector. use 'perf list' to list available events",
		     parse_events_option),
	OPT_CALLBACK(0, "filter", &record.evlist, "filter",
		     "event filter", parse_filter),
	OPT_STRING('p', "pid", &record.opts.target.pid, "pid",
		    "record events on existing process id"),
	OPT_STRING('t', "tid", &record.opts.target.tid, "tid",
		    "record events on existing thread id"),
	OPT_INTEGER('r', "realtime", &record.realtime_prio,
		    "collect data with this RT SCHED_FIFO priority"),
	OPT_BOOLEAN(0, "no-buffering", &record.opts.no_buffering,
		    "collect data without buffering"),
	OPT_BOOLEAN('R', "raw-samples", &record.opts.raw_samples,
		    "collect raw sample records from all opened counters"),
	OPT_BOOLEAN('a', "all-cpus", &record.opts.target.system_wide,
			    "system-wide collection from all CPUs"),
	OPT_STRING('C', "cpu", &record.opts.target.cpu_list, "cpu",
		    "list of cpus to monitor"),
	OPT_U64('c', "count", &record.opts.user_interval, "event period to sample"),
	OPT_STRING('o', "output", &record.file.path, "file",
		    "output file name"),
	OPT_BOOLEAN_SET('i', "no-inherit", &record.opts.no_inherit,
			&record.opts.no_inherit_set,
			"child tasks do not inherit counters"),
	OPT_UINTEGER('F', "freq", &record.opts.user_freq, "profile at this frequency"),
	OPT_CALLBACK('m', "mmap-pages", &record.opts.mmap_pages, "pages",
		     "number of mmap data pages",
		     perf_evlist__parse_mmap_pages),
	OPT_BOOLEAN(0, "group", &record.opts.group,
		    "put the counters into a counter group"),
	OPT_CALLBACK_NOOPT('g', NULL, &record.opts,
			   NULL, "enables call-graph recording" ,
			   &record_callchain_opt),
	OPT_CALLBACK(0, "call-graph", &record.opts,
		     "mode[,dump_size]", record_callchain_help,
		     &record_parse_callchain_opt),
	OPT_INCR('v', "verbose", &verbose,
		    "be more verbose (show counter open errors, etc)"),
	OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
	OPT_BOOLEAN('s', "stat", &record.opts.inherit_stat,
		    "per thread counts"),
	OPT_BOOLEAN('d', "data", &record.opts.sample_address,
		    "Sample addresses"),
	OPT_BOOLEAN('T', "timestamp", &record.opts.sample_time, "Sample timestamps"),
	OPT_BOOLEAN('P', "period", &record.opts.period, "Sample period"),
	OPT_BOOLEAN('n', "no-samples", &record.opts.no_samples,
		    "don't sample"),
	OPT_BOOLEAN('N', "no-buildid-cache", &record.no_buildid_cache,
		    "do not update the buildid cache"),
	OPT_BOOLEAN('B', "no-buildid", &record.no_buildid,
		    "do not collect buildids in perf.data"),
	OPT_CALLBACK('G', "cgroup", &record.evlist, "name",
		     "monitor event in cgroup name only",
		     parse_cgroups),
	OPT_UINTEGER('D', "delay", &record.opts.initial_delay,
		  "ms to wait before starting measurement after program start"),
	OPT_STRING('u', "uid", &record.opts.target.uid_str, "user",
		   "user to profile"),

	OPT_CALLBACK_NOOPT('b', "branch-any", &record.opts.branch_stack,
		     "branch any", "sample any taken branches",
		     parse_branch_stack),

	OPT_CALLBACK('j', "branch-filter", &record.opts.branch_stack,
		     "branch filter mask", "branch stack filter modes",
		     parse_branch_stack),
	OPT_BOOLEAN('W', "weight", &record.opts.sample_weight,
		    "sample by weight (on special events only)"),
	OPT_BOOLEAN(0, "transaction", &record.opts.sample_transaction,
		    "sample transaction flags (special events only)"),
	OPT_BOOLEAN(0, "per-thread", &record.opts.target.per_thread,
		    "use per-thread mmaps"),
	OPT_END()
};

int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
{
	int err = -ENOMEM;
	struct record *rec = &record;
	char errbuf[BUFSIZ];

	rec->evlist = perf_evlist__new();
	if (rec->evlist == NULL)
		return -ENOMEM;

	perf_config(perf_record_config, rec);

	argc = parse_options(argc, argv, record_options, record_usage,
			    PARSE_OPT_STOP_AT_NON_OPTION);
	if (!argc && target__none(&rec->opts.target))
		usage_with_options(record_usage, record_options);

	if (nr_cgroups && !rec->opts.target.system_wide) {
		ui__error("cgroup monitoring only available in"
			  " system-wide mode\n");
		usage_with_options(record_usage, record_options);
	}

	symbol__init();

	if (symbol_conf.kptr_restrict)
		pr_warning(
"WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n"
"check /proc/sys/kernel/kptr_restrict.\n\n"
"Samples in kernel functions may not be resolved if a suitable vmlinux\n"
"file is not found in the buildid cache or in the vmlinux path.\n\n"
"Samples in kernel modules won't be resolved at all.\n\n"
"If some relocation was applied (e.g. kexec) symbols may be misresolved\n"
"even with a suitable vmlinux or kallsyms file.\n\n");

	if (rec->no_buildid_cache || rec->no_buildid)
		disable_buildid_cache();

	if (rec->evlist->nr_entries == 0 &&
	    perf_evlist__add_default(rec->evlist) < 0) {
		pr_err("Not enough memory for event selector list\n");
		goto out_symbol_exit;
	}

	if (rec->opts.target.tid && !rec->opts.no_inherit_set)
		rec->opts.no_inherit = true;

	err = target__validate(&rec->opts.target);
	if (err) {
		target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
		ui__warning("%s", errbuf);
	}

	err = target__parse_uid(&rec->opts.target);
	if (err) {
		int saved_errno = errno;

		target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
		ui__error("%s", errbuf);

		err = -saved_errno;
		goto out_symbol_exit;
	}

	err = -ENOMEM;
	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
		usage_with_options(record_usage, record_options);

	if (record_opts__config(&rec->opts)) {
		err = -EINVAL;
		goto out_symbol_exit;
	}

	err = __cmd_record(&record, argc, argv);
out_symbol_exit:
	symbol__exit();
	return err;
}