summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/event.c
blob: 0fe9adf76379ecc02895cfbb46f35dcc8666dcbd (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
#include <linux/types.h>
#include "event.h"
#include "debug.h"
#include "session.h"
#include "sort.h"
#include "string.h"
#include "strlist.h"
#include "thread.h"
#include "thread_map.h"

static const char *perf_event__names[] = {
	[0]					= "TOTAL",
	[PERF_RECORD_MMAP]			= "MMAP",
	[PERF_RECORD_LOST]			= "LOST",
	[PERF_RECORD_COMM]			= "COMM",
	[PERF_RECORD_EXIT]			= "EXIT",
	[PERF_RECORD_THROTTLE]			= "THROTTLE",
	[PERF_RECORD_UNTHROTTLE]		= "UNTHROTTLE",
	[PERF_RECORD_FORK]			= "FORK",
	[PERF_RECORD_READ]			= "READ",
	[PERF_RECORD_SAMPLE]			= "SAMPLE",
	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
	[PERF_RECORD_HEADER_BUILD_ID]		= "BUILD_ID",
	[PERF_RECORD_FINISHED_ROUND]		= "FINISHED_ROUND",
};

const char *perf_event__name(unsigned int id)
{
	if (id >= ARRAY_SIZE(perf_event__names))
		return "INVALID";
	if (!perf_event__names[id])
		return "UNKNOWN";
	return perf_event__names[id];
}

int perf_sample_size(u64 sample_type)
{
	u64 mask = sample_type & PERF_SAMPLE_MASK;
	int size = 0;
	int i;

	for (i = 0; i < 64; i++) {
		if (mask & (1ULL << i))
			size++;
	}

	size *= sizeof(u64);

	return size;
}

static struct perf_sample synth_sample = {
	.pid	   = -1,
	.tid	   = -1,
	.time	   = -1,
	.stream_id = -1,
	.cpu	   = -1,
	.period	   = 1,
};

static pid_t perf_event__synthesize_comm(union perf_event *event, pid_t pid,
					 int full, perf_event__handler_t process,
					 struct perf_session *session)
{
	char filename[PATH_MAX];
	char bf[BUFSIZ];
	FILE *fp;
	size_t size = 0;
	DIR *tasks;
	struct dirent dirent, *next;
	pid_t tgid = 0;

	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);

	fp = fopen(filename, "r");
	if (fp == NULL) {
out_race:
		/*
		 * We raced with a task exiting - just return:
		 */
		pr_debug("couldn't open %s\n", filename);
		return 0;
	}

	memset(&event->comm, 0, sizeof(event->comm));

	while (!event->comm.comm[0] || !event->comm.pid) {
		if (fgets(bf, sizeof(bf), fp) == NULL) {
			pr_warning("couldn't get COMM and pgid, malformed %s\n", filename);
			goto out;
		}

		if (memcmp(bf, "Name:", 5) == 0) {
			char *name = bf + 5;
			while (*name && isspace(*name))
				++name;
			size = strlen(name) - 1;
			memcpy(event->comm.comm, name, size++);
		} else if (memcmp(bf, "Tgid:", 5) == 0) {
			char *tgids = bf + 5;
			while (*tgids && isspace(*tgids))
				++tgids;
			tgid = event->comm.pid = atoi(tgids);
		}
	}

	event->comm.header.type = PERF_RECORD_COMM;
	size = ALIGN(size, sizeof(u64));
	memset(event->comm.comm + size, 0, session->id_hdr_size);
	event->comm.header.size = (sizeof(event->comm) -
				(sizeof(event->comm.comm) - size) +
				session->id_hdr_size);
	if (!full) {
		event->comm.tid = pid;

		process(event, &synth_sample, session);
		goto out;
	}

	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);

	tasks = opendir(filename);
	if (tasks == NULL)
		goto out_race;

	while (!readdir_r(tasks, &dirent, &next) && next) {
		char *end;
		pid = strtol(dirent.d_name, &end, 10);
		if (*end)
			continue;

		event->comm.tid = pid;

		process(event, &synth_sample, session);
	}

	closedir(tasks);
out:
	fclose(fp);

	return tgid;
}

static int perf_event__synthesize_mmap_events(union perf_event *event,
					      pid_t pid, pid_t tgid,
					      perf_event__handler_t process,
					      struct perf_session *session)
{
	char filename[PATH_MAX];
	FILE *fp;

	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);

	fp = fopen(filename, "r");
	if (fp == NULL) {
		/*
		 * We raced with a task exiting - just return:
		 */
		pr_debug("couldn't open %s\n", filename);
		return -1;
	}

	event->header.type = PERF_RECORD_MMAP;
	/*
	 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
	 */
	event->header.misc = PERF_RECORD_MISC_USER;

	while (1) {
		char bf[BUFSIZ], *pbf = bf;
		int n;
		size_t size;
		if (fgets(bf, sizeof(bf), fp) == NULL)
			break;

		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
		n = hex2u64(pbf, &event->mmap.start);
		if (n < 0)
			continue;
		pbf += n + 1;
		n = hex2u64(pbf, &event->mmap.len);
		if (n < 0)
			continue;
		pbf += n + 3;
		if (*pbf == 'x') { /* vm_exec */
			char *execname = strchr(bf, '/');

			/* Catch VDSO */
			if (execname == NULL)
				execname = strstr(bf, "[vdso]");

			if (execname == NULL)
				continue;

			pbf += 3;
			n = hex2u64(pbf, &event->mmap.pgoff);

			size = strlen(execname);
			execname[size - 1] = '\0'; /* Remove \n */
			memcpy(event->mmap.filename, execname, size);
			size = ALIGN(size, sizeof(u64));
			event->mmap.len -= event->mmap.start;
			event->mmap.header.size = (sizeof(event->mmap) -
					        (sizeof(event->mmap.filename) - size));
			memset(event->mmap.filename + size, 0, session->id_hdr_size);
			event->mmap.header.size += session->id_hdr_size;
			event->mmap.pid = tgid;
			event->mmap.tid = pid;

			process(event, &synth_sample, session);
		}
	}

	fclose(fp);
	return 0;
}

int perf_event__synthesize_modules(perf_event__handler_t process,
				   struct perf_session *session,
				   struct machine *machine)
{
	struct rb_node *nd;
	struct map_groups *kmaps = &machine->kmaps;
	union perf_event *event = zalloc((sizeof(event->mmap) +
					  session->id_hdr_size));
	if (event == NULL) {
		pr_debug("Not enough memory synthesizing mmap event "
			 "for kernel modules\n");
		return -1;
	}

	event->header.type = PERF_RECORD_MMAP;

	/*
	 * kernel uses 0 for user space maps, see kernel/perf_event.c
	 * __perf_event_mmap
	 */
	if (machine__is_host(machine))
		event->header.misc = PERF_RECORD_MISC_KERNEL;
	else
		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;

	for (nd = rb_first(&kmaps->maps[MAP__FUNCTION]);
	     nd; nd = rb_next(nd)) {
		size_t size;
		struct map *pos = rb_entry(nd, struct map, rb_node);

		if (pos->dso->kernel)
			continue;

		size = ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
		event->mmap.header.type = PERF_RECORD_MMAP;
		event->mmap.header.size = (sizeof(event->mmap) -
				        (sizeof(event->mmap.filename) - size));
		memset(event->mmap.filename + size, 0, session->id_hdr_size);
		event->mmap.header.size += session->id_hdr_size;
		event->mmap.start = pos->start;
		event->mmap.len   = pos->end - pos->start;
		event->mmap.pid   = machine->pid;

		memcpy(event->mmap.filename, pos->dso->long_name,
		       pos->dso->long_name_len + 1);
		process(event, &synth_sample, session);
	}

	free(event);
	return 0;
}

static int __event__synthesize_thread(union perf_event *comm_event,
				      union perf_event *mmap_event,
				      pid_t pid, perf_event__handler_t process,
				      struct perf_session *session)
{
	pid_t tgid = perf_event__synthesize_comm(comm_event, pid, 1, process,
					    session);
	if (tgid == -1)
		return -1;
	return perf_event__synthesize_mmap_events(mmap_event, pid, tgid,
					     process, session);
}

int perf_event__synthesize_thread_map(struct thread_map *threads,
				      perf_event__handler_t process,
				      struct perf_session *session)
{
	union perf_event *comm_event, *mmap_event;
	int err = -1, thread;

	comm_event = malloc(sizeof(comm_event->comm) + session->id_hdr_size);
	if (comm_event == NULL)
		goto out;

	mmap_event = malloc(sizeof(mmap_event->mmap) + session->id_hdr_size);
	if (mmap_event == NULL)
		goto out_free_comm;

	err = 0;
	for (thread = 0; thread < threads->nr; ++thread) {
		if (__event__synthesize_thread(comm_event, mmap_event,
					       threads->map[thread],
					       process, session)) {
			err = -1;
			break;
		}
	}
	free(mmap_event);
out_free_comm:
	free(comm_event);
out:
	return err;
}

int perf_event__synthesize_threads(perf_event__handler_t process,
				   struct perf_session *session)
{
	DIR *proc;
	struct dirent dirent, *next;
	union perf_event *comm_event, *mmap_event;
	int err = -1;

	comm_event = malloc(sizeof(comm_event->comm) + session->id_hdr_size);
	if (comm_event == NULL)
		goto out;

	mmap_event = malloc(sizeof(mmap_event->mmap) + session->id_hdr_size);
	if (mmap_event == NULL)
		goto out_free_comm;

	proc = opendir("/proc");
	if (proc == NULL)
		goto out_free_mmap;

	while (!readdir_r(proc, &dirent, &next) && next) {
		char *end;
		pid_t pid = strtol(dirent.d_name, &end, 10);

		if (*end) /* only interested in proper numerical dirents */
			continue;

		__event__synthesize_thread(comm_event, mmap_event, pid,
					   process, session);
	}

	closedir(proc);
	err = 0;
out_free_mmap:
	free(mmap_event);
out_free_comm:
	free(comm_event);
out:
	return err;
}

struct process_symbol_args {
	const char *name;
	u64	   start;
};

static int find_symbol_cb(void *arg, const char *name, char type,
			  u64 start, u64 end __used)
{
	struct process_symbol_args *args = arg;

	/*
	 * Must be a function or at least an alias, as in PARISC64, where "_text" is
	 * an 'A' to the same address as "_stext".
	 */
	if (!(symbol_type__is_a(type, MAP__FUNCTION) ||
	      type == 'A') || strcmp(name, args->name))
		return 0;

	args->start = start;
	return 1;
}

int perf_event__synthesize_kernel_mmap(perf_event__handler_t process,
				       struct perf_session *session,
				       struct machine *machine,
				       const char *symbol_name)
{
	size_t size;
	const char *filename, *mmap_name;
	char path[PATH_MAX];
	char name_buff[PATH_MAX];
	struct map *map;
	int err;
	/*
	 * We should get this from /sys/kernel/sections/.text, but till that is
	 * available use this, and after it is use this as a fallback for older
	 * kernels.
	 */
	struct process_symbol_args args = { .name = symbol_name, };
	union perf_event *event = zalloc((sizeof(event->mmap) +
					  session->id_hdr_size));
	if (event == NULL) {
		pr_debug("Not enough memory synthesizing mmap event "
			 "for kernel modules\n");
		return -1;
	}

	mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
	if (machine__is_host(machine)) {
		/*
		 * kernel uses PERF_RECORD_MISC_USER for user space maps,
		 * see kernel/perf_event.c __perf_event_mmap
		 */
		event->header.misc = PERF_RECORD_MISC_KERNEL;
		filename = "/proc/kallsyms";
	} else {
		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
		if (machine__is_default_guest(machine))
			filename = (char *) symbol_conf.default_guest_kallsyms;
		else {
			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
			filename = path;
		}
	}

	if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0)
		return -ENOENT;

	map = machine->vmlinux_maps[MAP__FUNCTION];
	size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
			"%s%s", mmap_name, symbol_name) + 1;
	size = ALIGN(size, sizeof(u64));
	event->mmap.header.type = PERF_RECORD_MMAP;
	event->mmap.header.size = (sizeof(event->mmap) -
			(sizeof(event->mmap.filename) - size) + session->id_hdr_size);
	event->mmap.pgoff = args.start;
	event->mmap.start = map->start;
	event->mmap.len   = map->end - event->mmap.start;
	event->mmap.pid   = machine->pid;

	err = process(event, &synth_sample, session);
	free(event);

	return err;
}

int perf_event__process_comm(union perf_event *event,
			     struct perf_sample *sample __used,
			     struct perf_session *session)
{
	struct thread *thread = perf_session__findnew(session, event->comm.tid);

	dump_printf(": %s:%d\n", event->comm.comm, event->comm.tid);

	if (thread == NULL || thread__set_comm(thread, event->comm.comm)) {
		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
		return -1;
	}

	return 0;
}

int perf_event__process_lost(union perf_event *event,
			     struct perf_sample *sample __used,
			     struct perf_session *session)
{
	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
		    event->lost.id, event->lost.lost);
	session->hists.stats.total_lost += event->lost.lost;
	return 0;
}

static void perf_event__set_kernel_mmap_len(union perf_event *event,
					    struct map **maps)
{
	maps[MAP__FUNCTION]->start = event->mmap.start;
	maps[MAP__FUNCTION]->end   = event->mmap.start + event->mmap.len;
	/*
	 * Be a bit paranoid here, some perf.data file came with
	 * a zero sized synthesized MMAP event for the kernel.
	 */
	if (maps[MAP__FUNCTION]->end == 0)
		maps[MAP__FUNCTION]->end = ~0ULL;
}

static int perf_event__process_kernel_mmap(union perf_event *event,
					   struct perf_session *session)
{
	struct map *map;
	char kmmap_prefix[PATH_MAX];
	struct machine *machine;
	enum dso_kernel_type kernel_type;
	bool is_kernel_mmap;

	machine = perf_session__findnew_machine(session, event->mmap.pid);
	if (!machine) {
		pr_err("Can't find id %d's machine\n", event->mmap.pid);
		goto out_problem;
	}

	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
	if (machine__is_host(machine))
		kernel_type = DSO_TYPE_KERNEL;
	else
		kernel_type = DSO_TYPE_GUEST_KERNEL;

	is_kernel_mmap = memcmp(event->mmap.filename,
				kmmap_prefix,
				strlen(kmmap_prefix)) == 0;
	if (event->mmap.filename[0] == '/' ||
	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {

		char short_module_name[1024];
		char *name, *dot;

		if (event->mmap.filename[0] == '/') {
			name = strrchr(event->mmap.filename, '/');
			if (name == NULL)
				goto out_problem;

			++name; /* skip / */
			dot = strrchr(name, '.');
			if (dot == NULL)
				goto out_problem;
			snprintf(short_module_name, sizeof(short_module_name),
					"[%.*s]", (int)(dot - name), name);
			strxfrchar(short_module_name, '-', '_');
		} else
			strcpy(short_module_name, event->mmap.filename);

		map = machine__new_module(machine, event->mmap.start,
					  event->mmap.filename);
		if (map == NULL)
			goto out_problem;

		name = strdup(short_module_name);
		if (name == NULL)
			goto out_problem;

		map->dso->short_name = name;
		map->dso->sname_alloc = 1;
		map->end = map->start + event->mmap.len;
	} else if (is_kernel_mmap) {
		const char *symbol_name = (event->mmap.filename +
				strlen(kmmap_prefix));
		/*
		 * Should be there already, from the build-id table in
		 * the header.
		 */
		struct dso *kernel = __dsos__findnew(&machine->kernel_dsos,
						     kmmap_prefix);
		if (kernel == NULL)
			goto out_problem;

		kernel->kernel = kernel_type;
		if (__machine__create_kernel_maps(machine, kernel) < 0)
			goto out_problem;

		perf_event__set_kernel_mmap_len(event, machine->vmlinux_maps);

		/*
		 * Avoid using a zero address (kptr_restrict) for the ref reloc
		 * symbol. Effectively having zero here means that at record
		 * time /proc/sys/kernel/kptr_restrict was non zero.
		 */
		if (event->mmap.pgoff != 0) {
			perf_session__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
								 symbol_name,
								 event->mmap.pgoff);
		}

		if (machine__is_default_guest(machine)) {
			/*
			 * preload dso of guest kernel and modules
			 */
			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
				  NULL);
		}
	}
	return 0;
out_problem:
	return -1;
}

int perf_event__process_mmap(union perf_event *event,
			     struct perf_sample *sample __used,
			     struct perf_session *session)
{
	struct machine *machine;
	struct thread *thread;
	struct map *map;
	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
	int ret = 0;

	dump_printf(" %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %s\n",
			event->mmap.pid, event->mmap.tid, event->mmap.start,
			event->mmap.len, event->mmap.pgoff, event->mmap.filename);

	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
	    cpumode == PERF_RECORD_MISC_KERNEL) {
		ret = perf_event__process_kernel_mmap(event, session);
		if (ret < 0)
			goto out_problem;
		return 0;
	}

	machine = perf_session__find_host_machine(session);
	if (machine == NULL)
		goto out_problem;
	thread = perf_session__findnew(session, event->mmap.pid);
	if (thread == NULL)
		goto out_problem;
	map = map__new(&machine->user_dsos, event->mmap.start,
			event->mmap.len, event->mmap.pgoff,
			event->mmap.pid, event->mmap.filename,
			MAP__FUNCTION);
	if (map == NULL)
		goto out_problem;

	thread__insert_map(thread, map);
	return 0;

out_problem:
	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
	return 0;
}

int perf_event__process_task(union perf_event *event,
			     struct perf_sample *sample __used,
			     struct perf_session *session)
{
	struct thread *thread = perf_session__findnew(session, event->fork.tid);
	struct thread *parent = perf_session__findnew(session, event->fork.ptid);

	dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
		    event->fork.ppid, event->fork.ptid);

	if (event->header.type == PERF_RECORD_EXIT) {
		perf_session__remove_thread(session, thread);
		return 0;
	}

	if (thread == NULL || parent == NULL ||
	    thread__fork(thread, parent) < 0) {
		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
		return -1;
	}

	return 0;
}

int perf_event__process(union perf_event *event, struct perf_sample *sample,
			struct perf_session *session)
{
	switch (event->header.type) {
	case PERF_RECORD_COMM:
		perf_event__process_comm(event, sample, session);
		break;
	case PERF_RECORD_MMAP:
		perf_event__process_mmap(event, sample, session);
		break;
	case PERF_RECORD_FORK:
	case PERF_RECORD_EXIT:
		perf_event__process_task(event, sample, session);
		break;
	case PERF_RECORD_LOST:
		perf_event__process_lost(event, sample, session);
	default:
		break;
	}

	return 0;
}

void thread__find_addr_map(struct thread *self,
			   struct perf_session *session, u8 cpumode,
			   enum map_type type, pid_t pid, u64 addr,
			   struct addr_location *al)
{
	struct map_groups *mg = &self->mg;
	struct machine *machine = NULL;

	al->thread = self;
	al->addr = addr;
	al->cpumode = cpumode;
	al->filtered = false;

	if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
		al->level = 'k';
		machine = perf_session__find_host_machine(session);
		if (machine == NULL) {
			al->map = NULL;
			return;
		}
		mg = &machine->kmaps;
	} else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
		al->level = '.';
		machine = perf_session__find_host_machine(session);
	} else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
		al->level = 'g';
		machine = perf_session__find_machine(session, pid);
		if (machine == NULL) {
			al->map = NULL;
			return;
		}
		mg = &machine->kmaps;
	} else {
		/*
		 * 'u' means guest os user space.
		 * TODO: We don't support guest user space. Might support late.
		 */
		if (cpumode == PERF_RECORD_MISC_GUEST_USER && perf_guest)
			al->level = 'u';
		else
			al->level = 'H';
		al->map = NULL;

		if ((cpumode == PERF_RECORD_MISC_GUEST_USER ||
			cpumode == PERF_RECORD_MISC_GUEST_KERNEL) &&
			!perf_guest)
			al->filtered = true;
		if ((cpumode == PERF_RECORD_MISC_USER ||
			cpumode == PERF_RECORD_MISC_KERNEL) &&
			!perf_host)
			al->filtered = true;

		return;
	}
try_again:
	al->map = map_groups__find(mg, type, al->addr);
	if (al->map == NULL) {
		/*
		 * If this is outside of all known maps, and is a negative
		 * address, try to look it up in the kernel dso, as it might be
		 * a vsyscall or vdso (which executes in user-mode).
		 *
		 * XXX This is nasty, we should have a symbol list in the
		 * "[vdso]" dso, but for now lets use the old trick of looking
		 * in the whole kernel symbol list.
		 */
		if ((long long)al->addr < 0 &&
		    cpumode == PERF_RECORD_MISC_USER &&
		    machine && mg != &machine->kmaps) {
			mg = &machine->kmaps;
			goto try_again;
		}
	} else
		al->addr = al->map->map_ip(al->map, al->addr);
}

void thread__find_addr_location(struct thread *self,
				struct perf_session *session, u8 cpumode,
				enum map_type type, pid_t pid, u64 addr,
				struct addr_location *al,
				symbol_filter_t filter)
{
	thread__find_addr_map(self, session, cpumode, type, pid, addr, al);
	if (al->map != NULL)
		al->sym = map__find_symbol(al->map, al->addr, filter);
	else
		al->sym = NULL;
}

int perf_event__preprocess_sample(const union perf_event *event,
				  struct perf_session *session,
				  struct addr_location *al,
				  struct perf_sample *sample,
				  symbol_filter_t filter)
{
	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
	struct thread *thread = perf_session__findnew(session, event->ip.pid);

	if (thread == NULL)
		return -1;

	if (symbol_conf.comm_list &&
	    !strlist__has_entry(symbol_conf.comm_list, thread->comm))
		goto out_filtered;

	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
	/*
	 * Have we already created the kernel maps for the host machine?
	 *
	 * This should have happened earlier, when we processed the kernel MMAP
	 * events, but for older perf.data files there was no such thing, so do
	 * it now.
	 */
	if (cpumode == PERF_RECORD_MISC_KERNEL &&
	    session->host_machine.vmlinux_maps[MAP__FUNCTION] == NULL)
		machine__create_kernel_maps(&session->host_machine);

	thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
			      event->ip.pid, event->ip.ip, al);
	dump_printf(" ...... dso: %s\n",
		    al->map ? al->map->dso->long_name :
			al->level == 'H' ? "[hypervisor]" : "<not found>");
	al->sym = NULL;
	al->cpu = sample->cpu;

	if (al->map) {
		if (symbol_conf.dso_list &&
		    (!al->map || !al->map->dso ||
		     !(strlist__has_entry(symbol_conf.dso_list,
					  al->map->dso->short_name) ||
		       (al->map->dso->short_name != al->map->dso->long_name &&
			strlist__has_entry(symbol_conf.dso_list,
					   al->map->dso->long_name)))))
			goto out_filtered;

		al->sym = map__find_symbol(al->map, al->addr, filter);
	}

	if (symbol_conf.sym_list && al->sym &&
	    !strlist__has_entry(symbol_conf.sym_list, al->sym->name))
		goto out_filtered;

	return 0;

out_filtered:
	al->filtered = true;
	return 0;
}