aboutsummaryrefslogtreecommitdiff
path: root/tools/perf/util/header.c
blob: d7e67b167ea338a28fed519260f1069dd8e92cf9 (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
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
#define _FILE_OFFSET_BITS 64

#include <sys/types.h>
#include <byteswap.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/list.h>
#include <linux/kernel.h>

#include "util.h"
#include "header.h"
#include "../perf.h"
#include "trace-event.h"
#include "session.h"
#include "symbol.h"
#include "debug.h"

static bool no_buildid_cache = false;

/*
 * Create new perf.data header attribute:
 */
struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
{
	struct perf_header_attr *self = malloc(sizeof(*self));

	if (self != NULL) {
		self->attr = *attr;
		self->ids  = 0;
		self->size = 1;
		self->id   = malloc(sizeof(u64));
		if (self->id == NULL) {
			free(self);
			self = NULL;
		}
	}

	return self;
}

void perf_header_attr__delete(struct perf_header_attr *self)
{
	free(self->id);
	free(self);
}

int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
{
	int pos = self->ids;

	self->ids++;
	if (self->ids > self->size) {
		int nsize = self->size * 2;
		u64 *nid = realloc(self->id, nsize * sizeof(u64));

		if (nid == NULL)
			return -1;

		self->size = nsize;
		self->id = nid;
	}
	self->id[pos] = id;
	return 0;
}

int perf_header__init(struct perf_header *self)
{
	self->size = 1;
	self->attr = malloc(sizeof(void *));
	return self->attr == NULL ? -ENOMEM : 0;
}

void perf_header__exit(struct perf_header *self)
{
	int i;
	for (i = 0; i < self->attrs; ++i)
                perf_header_attr__delete(self->attr[i]);
	free(self->attr);
}

int perf_header__add_attr(struct perf_header *self,
			  struct perf_header_attr *attr)
{
	if (self->frozen)
		return -1;

	if (self->attrs == self->size) {
		int nsize = self->size * 2;
		struct perf_header_attr **nattr;

		nattr = realloc(self->attr, nsize * sizeof(void *));
		if (nattr == NULL)
			return -1;

		self->size = nsize;
		self->attr = nattr;
	}

	self->attr[self->attrs++] = attr;
	return 0;
}

static int event_count;
static struct perf_trace_event_type *events;

int perf_header__push_event(u64 id, const char *name)
{
	if (strlen(name) > MAX_EVENT_NAME)
		pr_warning("Event %s will be truncated\n", name);

	if (!events) {
		events = malloc(sizeof(struct perf_trace_event_type));
		if (events == NULL)
			return -ENOMEM;
	} else {
		struct perf_trace_event_type *nevents;

		nevents = realloc(events, (event_count + 1) * sizeof(*events));
		if (nevents == NULL)
			return -ENOMEM;
		events = nevents;
	}
	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
	events[event_count].event_id = id;
	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
	event_count++;
	return 0;
}

char *perf_header__find_event(u64 id)
{
	int i;
	for (i = 0 ; i < event_count; i++) {
		if (events[i].event_id == id)
			return events[i].name;
	}
	return NULL;
}

static const char *__perf_magic = "PERFFILE";

#define PERF_MAGIC	(*(u64 *)__perf_magic)

struct perf_file_attr {
	struct perf_event_attr	attr;
	struct perf_file_section	ids;
};

void perf_header__set_feat(struct perf_header *self, int feat)
{
	set_bit(feat, self->adds_features);
}

bool perf_header__has_feat(const struct perf_header *self, int feat)
{
	return test_bit(feat, self->adds_features);
}

static int do_write(int fd, const void *buf, size_t size)
{
	while (size) {
		int ret = write(fd, buf, size);

		if (ret < 0)
			return -errno;

		size -= ret;
		buf += ret;
	}

	return 0;
}

#define NAME_ALIGN 64

static int write_padded(int fd, const void *bf, size_t count,
			size_t count_aligned)
{
	static const char zero_buf[NAME_ALIGN];
	int err = do_write(fd, bf, count);

	if (!err)
		err = do_write(fd, zero_buf, count_aligned - count);

	return err;
}

#define dsos__for_each_with_build_id(pos, head)	\
	list_for_each_entry(pos, head, node)	\
		if (!pos->has_build_id)		\
			continue;		\
		else

static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
				u16 misc, int fd)
{
	struct dso *pos;

	dsos__for_each_with_build_id(pos, head) {
		int err;
		struct build_id_event b;
		size_t len;

		if (!pos->hit)
			continue;
		len = pos->long_name_len + 1;
		len = ALIGN(len, NAME_ALIGN);
		memset(&b, 0, sizeof(b));
		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
		b.pid = pid;
		b.header.misc = misc;
		b.header.size = sizeof(b) + len;
		err = do_write(fd, &b, sizeof(b));
		if (err < 0)
			return err;
		err = write_padded(fd, pos->long_name,
				   pos->long_name_len + 1, len);
		if (err < 0)
			return err;
	}

	return 0;
}

static int machine__write_buildid_table(struct machine *self, int fd)
{
	int err;
	u16 kmisc = PERF_RECORD_MISC_KERNEL,
	    umisc = PERF_RECORD_MISC_USER;

	if (!machine__is_host(self)) {
		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
		umisc = PERF_RECORD_MISC_GUEST_USER;
	}

	err = __dsos__write_buildid_table(&self->kernel_dsos, self->pid,
					  kmisc, fd);
	if (err == 0)
		err = __dsos__write_buildid_table(&self->user_dsos,
						  self->pid, umisc, fd);
	return err;
}

static int dsos__write_buildid_table(struct perf_header *header, int fd)
{
	struct perf_session *session = container_of(header,
			struct perf_session, header);
	struct rb_node *nd;
	int err = machine__write_buildid_table(&session->host_machine, fd);

	if (err)
		return err;

	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		err = machine__write_buildid_table(pos, fd);
		if (err)
			break;
	}
	return err;
}

int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
			  const char *name, bool is_kallsyms)
{
	const size_t size = PATH_MAX;
	char *filename = malloc(size),
	     *linkname = malloc(size), *targetname;
	int len, err = -1;

	if (filename == NULL || linkname == NULL)
		goto out_free;

	len = snprintf(filename, size, "%s%s%s",
		       debugdir, is_kallsyms ? "/" : "", name);
	if (mkdir_p(filename, 0755))
		goto out_free;

	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);

	if (access(filename, F_OK)) {
		if (is_kallsyms) {
			 if (copyfile("/proc/kallsyms", filename))
				goto out_free;
		} else if (link(name, filename) && copyfile(name, filename))
			goto out_free;
	}

	len = snprintf(linkname, size, "%s/.build-id/%.2s",
		       debugdir, sbuild_id);

	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
		goto out_free;

	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
	targetname = filename + strlen(debugdir) - 5;
	memcpy(targetname, "../..", 5);

	if (symlink(targetname, linkname) == 0)
		err = 0;
out_free:
	free(filename);
	free(linkname);
	return err;
}

static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
				 const char *name, const char *debugdir,
				 bool is_kallsyms)
{
	char sbuild_id[BUILD_ID_SIZE * 2 + 1];

	build_id__sprintf(build_id, build_id_size, sbuild_id);

	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
}

int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
{
	const size_t size = PATH_MAX;
	char *filename = malloc(size),
	     *linkname = malloc(size);
	int err = -1;

	if (filename == NULL || linkname == NULL)
		goto out_free;

	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, sbuild_id + 2);

	if (access(linkname, F_OK))
		goto out_free;

	if (readlink(linkname, filename, size) < 0)
		goto out_free;

	if (unlink(linkname))
		goto out_free;

	/*
	 * Since the link is relative, we must make it absolute:
	 */
	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, filename);

	if (unlink(linkname))
		goto out_free;

	err = 0;
out_free:
	free(filename);
	free(linkname);
	return err;
}

static int dso__cache_build_id(struct dso *self, const char *debugdir)
{
	bool is_kallsyms = self->kernel && self->long_name[0] != '/';

	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
				     self->long_name, debugdir, is_kallsyms);
}

static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
{
	struct dso *pos;
	int err = 0;

	dsos__for_each_with_build_id(pos, head)
		if (dso__cache_build_id(pos, debugdir))
			err = -1;

	return err;
}

static int machine__cache_build_ids(struct machine *self, const char *debugdir)
{
	int ret = __dsos__cache_build_ids(&self->kernel_dsos, debugdir);
	ret |= __dsos__cache_build_ids(&self->user_dsos, debugdir);
	return ret;
}

static int perf_session__cache_build_ids(struct perf_session *self)
{
	struct rb_node *nd;
	int ret;
	char debugdir[PATH_MAX];

	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);

	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
		return -1;

	ret = machine__cache_build_ids(&self->host_machine, debugdir);

	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		ret |= machine__cache_build_ids(pos, debugdir);
	}
	return ret ? -1 : 0;
}

static bool machine__read_build_ids(struct machine *self, bool with_hits)
{
	bool ret = __dsos__read_build_ids(&self->kernel_dsos, with_hits);
	ret |= __dsos__read_build_ids(&self->user_dsos, with_hits);
	return ret;
}

static bool perf_session__read_build_ids(struct perf_session *self, bool with_hits)
{
	struct rb_node *nd;
	bool ret = machine__read_build_ids(&self->host_machine, with_hits);

	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		ret |= machine__read_build_ids(pos, with_hits);
	}

	return ret;
}

static int perf_header__adds_write(struct perf_header *self, int fd)
{
	int nr_sections;
	struct perf_session *session;
	struct perf_file_section *feat_sec;
	int sec_size;
	u64 sec_start;
	int idx = 0, err;

	session = container_of(self, struct perf_session, header);
	if (perf_session__read_build_ids(session, true))
		perf_header__set_feat(self, HEADER_BUILD_ID);

	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
	if (!nr_sections)
		return 0;

	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
	if (feat_sec == NULL)
		return -ENOMEM;

	sec_size = sizeof(*feat_sec) * nr_sections;

	sec_start = self->data_offset + self->data_size;
	lseek(fd, sec_start + sec_size, SEEK_SET);

	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
		struct perf_file_section *trace_sec;

		trace_sec = &feat_sec[idx++];

		/* Write trace info */
		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
		read_tracing_data(fd, attrs, nr_counters);
		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
	}

	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
		struct perf_file_section *buildid_sec;

		buildid_sec = &feat_sec[idx++];

		/* Write build-ids */
		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
		err = dsos__write_buildid_table(self, fd);
		if (err < 0) {
			pr_debug("failed to write buildid table\n");
			goto out_free;
		}
		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
					  buildid_sec->offset;
		if (!no_buildid_cache)
			perf_session__cache_build_ids(session);
	}

	lseek(fd, sec_start, SEEK_SET);
	err = do_write(fd, feat_sec, sec_size);
	if (err < 0)
		pr_debug("failed to write feature section\n");
out_free:
	free(feat_sec);
	return err;
}

int perf_header__write_pipe(int fd)
{
	struct perf_pipe_file_header f_header;
	int err;

	f_header = (struct perf_pipe_file_header){
		.magic	   = PERF_MAGIC,
		.size	   = sizeof(f_header),
	};

	err = do_write(fd, &f_header, sizeof(f_header));
	if (err < 0) {
		pr_debug("failed to write perf pipe header\n");
		return err;
	}

	return 0;
}

int perf_header__write(struct perf_header *self, int fd, bool at_exit)
{
	struct perf_file_header f_header;
	struct perf_file_attr   f_attr;
	struct perf_header_attr	*attr;
	int i, err;

	lseek(fd, sizeof(f_header), SEEK_SET);

	for (i = 0; i < self->attrs; i++) {
		attr = self->attr[i];

		attr->id_offset = lseek(fd, 0, SEEK_CUR);
		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
		if (err < 0) {
			pr_debug("failed to write perf header\n");
			return err;
		}
	}


	self->attr_offset = lseek(fd, 0, SEEK_CUR);

	for (i = 0; i < self->attrs; i++) {
		attr = self->attr[i];

		f_attr = (struct perf_file_attr){
			.attr = attr->attr,
			.ids  = {
				.offset = attr->id_offset,
				.size   = attr->ids * sizeof(u64),
			}
		};
		err = do_write(fd, &f_attr, sizeof(f_attr));
		if (err < 0) {
			pr_debug("failed to write perf header attribute\n");
			return err;
		}
	}

	self->event_offset = lseek(fd, 0, SEEK_CUR);
	self->event_size = event_count * sizeof(struct perf_trace_event_type);
	if (events) {
		err = do_write(fd, events, self->event_size);
		if (err < 0) {
			pr_debug("failed to write perf header events\n");
			return err;
		}
	}

	self->data_offset = lseek(fd, 0, SEEK_CUR);

	if (at_exit) {
		err = perf_header__adds_write(self, fd);
		if (err < 0)
			return err;
	}

	f_header = (struct perf_file_header){
		.magic	   = PERF_MAGIC,
		.size	   = sizeof(f_header),
		.attr_size = sizeof(f_attr),
		.attrs = {
			.offset = self->attr_offset,
			.size   = self->attrs * sizeof(f_attr),
		},
		.data = {
			.offset = self->data_offset,
			.size	= self->data_size,
		},
		.event_types = {
			.offset = self->event_offset,
			.size	= self->event_size,
		},
	};

	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));

	lseek(fd, 0, SEEK_SET);
	err = do_write(fd, &f_header, sizeof(f_header));
	if (err < 0) {
		pr_debug("failed to write perf header\n");
		return err;
	}
	lseek(fd, self->data_offset + self->data_size, SEEK_SET);

	self->frozen = 1;
	return 0;
}

static int perf_header__getbuffer64(struct perf_header *self,
				    int fd, void *buf, size_t size)
{
	if (do_read(fd, buf, size) <= 0)
		return -1;

	if (self->needs_swap)
		mem_bswap_64(buf, size);

	return 0;
}

int perf_header__process_sections(struct perf_header *self, int fd,
				  int (*process)(struct perf_file_section *self,
						 struct perf_header *ph,
						 int feat, int fd))
{
	struct perf_file_section *feat_sec;
	int nr_sections;
	int sec_size;
	int idx = 0;
	int err = -1, feat = 1;

	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
	if (!nr_sections)
		return 0;

	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
	if (!feat_sec)
		return -1;

	sec_size = sizeof(*feat_sec) * nr_sections;

	lseek(fd, self->data_offset + self->data_size, SEEK_SET);

	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
		goto out_free;

	err = 0;
	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
		if (perf_header__has_feat(self, feat)) {
			struct perf_file_section *sec = &feat_sec[idx++];

			err = process(sec, self, feat, fd);
			if (err < 0)
				break;
		}
		++feat;
	}
out_free:
	free(feat_sec);
	return err;
}

int perf_file_header__read(struct perf_file_header *self,
			   struct perf_header *ph, int fd)
{
	lseek(fd, 0, SEEK_SET);

	if (do_read(fd, self, sizeof(*self)) <= 0 ||
	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
		return -1;

	if (self->attr_size != sizeof(struct perf_file_attr)) {
		u64 attr_size = bswap_64(self->attr_size);

		if (attr_size != sizeof(struct perf_file_attr))
			return -1;

		mem_bswap_64(self, offsetof(struct perf_file_header,
					    adds_features));
		ph->needs_swap = true;
	}

	if (self->size != sizeof(*self)) {
		/* Support the previous format */
		if (self->size == offsetof(typeof(*self), adds_features))
			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
		else
			return -1;
	}

	memcpy(&ph->adds_features, &self->adds_features,
	       sizeof(ph->adds_features));
	/*
	 * FIXME: hack that assumes that if we need swap the perf.data file
	 * may be coming from an arch with a different word-size, ergo different
	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
	 * safe to assume that we have a build-id section. Trace files probably
	 * have several other issues in this realm anyway...
	 */
	if (ph->needs_swap) {
		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
		perf_header__set_feat(ph, HEADER_BUILD_ID);
	}

	ph->event_offset = self->event_types.offset;
	ph->event_size   = self->event_types.size;
	ph->data_offset  = self->data.offset;
	ph->data_size	 = self->data.size;
	return 0;
}

static int __event_process_build_id(struct build_id_event *bev,
				    char *filename,
				    struct perf_session *session)
{
	int err = -1;
	struct list_head *head;
	struct machine *machine;
	u16 misc;
	struct dso *dso;
	enum dso_kernel_type dso_type;

	machine = perf_session__findnew_machine(session, bev->pid);
	if (!machine)
		goto out;

	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

	switch (misc) {
	case PERF_RECORD_MISC_KERNEL:
		dso_type = DSO_TYPE_KERNEL;
		head = &machine->kernel_dsos;
		break;
	case PERF_RECORD_MISC_GUEST_KERNEL:
		dso_type = DSO_TYPE_GUEST_KERNEL;
		head = &machine->kernel_dsos;
		break;
	case PERF_RECORD_MISC_USER:
	case PERF_RECORD_MISC_GUEST_USER:
		dso_type = DSO_TYPE_USER;
		head = &machine->user_dsos;
		break;
	default:
		goto out;
	}

	dso = __dsos__findnew(head, filename);
	if (dso != NULL) {
		char sbuild_id[BUILD_ID_SIZE * 2 + 1];

		dso__set_build_id(dso, &bev->build_id);

		if (filename[0] == '[')
			dso->kernel = dso_type;

		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
				  sbuild_id);
		pr_debug("build id event received for %s: %s\n",
			 dso->long_name, sbuild_id);
	}

	err = 0;
out:
	return err;
}

static int perf_header__read_build_ids(struct perf_header *self,
			int input, u64 offset, u64 size)
{
	struct perf_session *session = container_of(self,
			struct perf_session, header);
	struct build_id_event bev;
	char filename[PATH_MAX];
	u64 limit = offset + size;
	int err = -1;

	while (offset < limit) {
		ssize_t len;

		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
			goto out;

		if (self->needs_swap)
			perf_event_header__bswap(&bev.header);

		len = bev.header.size - sizeof(bev);
		if (read(input, filename, len) != len)
			goto out;

		__event_process_build_id(&bev, filename, session);

		offset += bev.header.size;
	}
	err = 0;
out:
	return err;
}

static int perf_file_section__process(struct perf_file_section *self,
				      struct perf_header *ph,
				      int feat, int fd)
{
	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
		pr_debug("Failed to lseek to %Ld offset for feature %d, "
			 "continuing...\n", self->offset, feat);
		return 0;
	}

	switch (feat) {
	case HEADER_TRACE_INFO:
		trace_report(fd, false);
		break;

	case HEADER_BUILD_ID:
		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
			pr_debug("Failed to read buildids, continuing...\n");
		break;
	default:
		pr_debug("unknown feature %d, continuing...\n", feat);
	}

	return 0;
}

static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
				       struct perf_header *ph, int fd,
				       bool repipe)
{
	if (do_read(fd, self, sizeof(*self)) <= 0 ||
	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
		return -1;

	if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
		return -1;

	if (self->size != sizeof(*self)) {
		u64 size = bswap_64(self->size);

		if (size != sizeof(*self))
			return -1;

		ph->needs_swap = true;
	}

	return 0;
}

static int perf_header__read_pipe(struct perf_session *session, int fd)
{
	struct perf_header *self = &session->header;
	struct perf_pipe_file_header f_header;

	if (perf_file_header__read_pipe(&f_header, self, fd,
					session->repipe) < 0) {
		pr_debug("incompatible file format\n");
		return -EINVAL;
	}

	session->fd = fd;

	return 0;
}

int perf_header__read(struct perf_session *session, int fd)
{
	struct perf_header *self = &session->header;
	struct perf_file_header	f_header;
	struct perf_file_attr	f_attr;
	u64			f_id;
	int nr_attrs, nr_ids, i, j;

	if (session->fd_pipe)
		return perf_header__read_pipe(session, fd);

	if (perf_file_header__read(&f_header, self, fd) < 0) {
		pr_debug("incompatible file format\n");
		return -EINVAL;
	}

	nr_attrs = f_header.attrs.size / sizeof(f_attr);
	lseek(fd, f_header.attrs.offset, SEEK_SET);

	for (i = 0; i < nr_attrs; i++) {
		struct perf_header_attr *attr;
		off_t tmp;

		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
			goto out_errno;

		tmp = lseek(fd, 0, SEEK_CUR);

		attr = perf_header_attr__new(&f_attr.attr);
		if (attr == NULL)
			 return -ENOMEM;

		nr_ids = f_attr.ids.size / sizeof(u64);
		lseek(fd, f_attr.ids.offset, SEEK_SET);

		for (j = 0; j < nr_ids; j++) {
			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
				goto out_errno;

			if (perf_header_attr__add_id(attr, f_id) < 0) {
				perf_header_attr__delete(attr);
				return -ENOMEM;
			}
		}
		if (perf_header__add_attr(self, attr) < 0) {
			perf_header_attr__delete(attr);
			return -ENOMEM;
		}

		lseek(fd, tmp, SEEK_SET);
	}

	if (f_header.event_types.size) {
		lseek(fd, f_header.event_types.offset, SEEK_SET);
		events = malloc(f_header.event_types.size);
		if (events == NULL)
			return -ENOMEM;
		if (perf_header__getbuffer64(self, fd, events,
					     f_header.event_types.size))
			goto out_errno;
		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
	}

	perf_header__process_sections(self, fd, perf_file_section__process);

	lseek(fd, self->data_offset, SEEK_SET);

	self->frozen = 1;
	return 0;
out_errno:
	return -errno;
}

u64 perf_header__sample_type(struct perf_header *header)
{
	u64 type = 0;
	int i;

	for (i = 0; i < header->attrs; i++) {
		struct perf_header_attr *attr = header->attr[i];

		if (!type)
			type = attr->attr.sample_type;
		else if (type != attr->attr.sample_type)
			die("non matching sample_type");
	}

	return type;
}

struct perf_event_attr *
perf_header__find_attr(u64 id, struct perf_header *header)
{
	int i;

	/*
	 * We set id to -1 if the data file doesn't contain sample
	 * ids. Check for this and avoid walking through the entire
	 * list of ids which may be large.
	 */
	if (id == -1ULL)
		return NULL;

	for (i = 0; i < header->attrs; i++) {
		struct perf_header_attr *attr = header->attr[i];
		int j;

		for (j = 0; j < attr->ids; j++) {
			if (attr->id[j] == id)
				return &attr->attr;
		}
	}

	return NULL;
}

int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
			   event__handler_t process,
			   struct perf_session *session)
{
	event_t *ev;
	size_t size;
	int err;

	size = sizeof(struct perf_event_attr);
	size = ALIGN(size, sizeof(u64));
	size += sizeof(struct perf_event_header);
	size += ids * sizeof(u64);

	ev = malloc(size);

	ev->attr.attr = *attr;
	memcpy(ev->attr.id, id, ids * sizeof(u64));

	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
	ev->attr.header.size = size;

	err = process(ev, session);

	free(ev);

	return err;
}

int event__synthesize_attrs(struct perf_header *self,
			    event__handler_t process,
			    struct perf_session *session)
{
	struct perf_header_attr	*attr;
	int i, err = 0;

	for (i = 0; i < self->attrs; i++) {
		attr = self->attr[i];

		err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
					     process, session);
		if (err) {
			pr_debug("failed to create perf header attribute\n");
			return err;
		}
	}

	return err;
}

int event__process_attr(event_t *self, struct perf_session *session)
{
	struct perf_header_attr *attr;
	unsigned int i, ids, n_ids;

	attr = perf_header_attr__new(&self->attr.attr);
	if (attr == NULL)
		return -ENOMEM;

	ids = self->header.size;
	ids -= (void *)&self->attr.id - (void *)self;
	n_ids = ids / sizeof(u64);

	for (i = 0; i < n_ids; i++) {
		if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
			perf_header_attr__delete(attr);
			return -ENOMEM;
		}
	}

	if (perf_header__add_attr(&session->header, attr) < 0) {
		perf_header_attr__delete(attr);
		return -ENOMEM;
	}

	perf_session__update_sample_type(session);

	return 0;
}

int event__synthesize_event_type(u64 event_id, char *name,
				 event__handler_t process,
				 struct perf_session *session)
{
	event_t ev;
	size_t size = 0;
	int err = 0;

	memset(&ev, 0, sizeof(ev));

	ev.event_type.event_type.event_id = event_id;
	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);

	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
	size = strlen(name);
	size = ALIGN(size, sizeof(u64));
	ev.event_type.header.size = sizeof(ev.event_type) -
		(sizeof(ev.event_type.event_type.name) - size);

	err = process(&ev, session);

	return err;
}

int event__synthesize_event_types(event__handler_t process,
				  struct perf_session *session)
{
	struct perf_trace_event_type *type;
	int i, err = 0;

	for (i = 0; i < event_count; i++) {
		type = &events[i];

		err = event__synthesize_event_type(type->event_id, type->name,
						   process, session);
		if (err) {
			pr_debug("failed to create perf header event type\n");
			return err;
		}
	}

	return err;
}

int event__process_event_type(event_t *self,
			      struct perf_session *session __unused)
{
	if (perf_header__push_event(self->event_type.event_type.event_id,
				    self->event_type.event_type.name) < 0)
		return -ENOMEM;

	return 0;
}

int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
				   int nb_events,
				   event__handler_t process,
				   struct perf_session *session __unused)
{
	event_t ev;
	ssize_t size = 0, aligned_size = 0, padding;
	int err = 0;

	memset(&ev, 0, sizeof(ev));

	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
	size = read_tracing_data_size(fd, pattrs, nb_events);
	if (size <= 0)
		return size;
	aligned_size = ALIGN(size, sizeof(u64));
	padding = aligned_size - size;
	ev.tracing_data.header.size = sizeof(ev.tracing_data);
	ev.tracing_data.size = aligned_size;

	process(&ev, session);

	err = read_tracing_data(fd, pattrs, nb_events);
	write_padded(fd, NULL, 0, padding);

	return aligned_size;
}

int event__process_tracing_data(event_t *self,
				struct perf_session *session)
{
	ssize_t size_read, padding, size = self->tracing_data.size;
	off_t offset = lseek(session->fd, 0, SEEK_CUR);
	char buf[BUFSIZ];

	/* setup for reading amidst mmap */
	lseek(session->fd, offset + sizeof(struct tracing_data_event),
	      SEEK_SET);

	size_read = trace_report(session->fd, session->repipe);

	padding = ALIGN(size_read, sizeof(u64)) - size_read;

	if (read(session->fd, buf, padding) < 0)
		die("reading input file");
	if (session->repipe) {
		int retw = write(STDOUT_FILENO, buf, padding);
		if (retw <= 0 || retw != padding)
			die("repiping tracing data padding");
	}

	if (size_read + padding != size)
		die("tracing data size mismatch");

	return size_read + padding;
}

int event__synthesize_build_id(struct dso *pos, u16 misc,
			       event__handler_t process,
			       struct machine *machine,
			       struct perf_session *session)
{
	event_t ev;
	size_t len;
	int err = 0;

	if (!pos->hit)
		return err;

	memset(&ev, 0, sizeof(ev));

	len = pos->long_name_len + 1;
	len = ALIGN(len, NAME_ALIGN);
	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
	ev.build_id.header.misc = misc;
	ev.build_id.pid = machine->pid;
	ev.build_id.header.size = sizeof(ev.build_id) + len;
	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);

	err = process(&ev, session);

	return err;
}

int event__process_build_id(event_t *self,
			    struct perf_session *session)
{
	__event_process_build_id(&self->build_id,
				 self->build_id.filename,
				 session);
	return 0;
}

void disable_buildid_cache(void)
{
	no_buildid_cache = true;
}