xref: /linux/tools/perf/util/header.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 #define _FILE_OFFSET_BITS 64
2 
3 #include <sys/types.h>
4 #include <byteswap.h>
5 #include <unistd.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <linux/list.h>
9 #include <linux/kernel.h>
10 
11 #include "util.h"
12 #include "header.h"
13 #include "../perf.h"
14 #include "trace-event.h"
15 #include "session.h"
16 #include "symbol.h"
17 #include "debug.h"
18 
19 static bool no_buildid_cache = false;
20 
21 /*
22  * Create new perf.data header attribute:
23  */
24 struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
25 {
26 	struct perf_header_attr *self = malloc(sizeof(*self));
27 
28 	if (self != NULL) {
29 		self->attr = *attr;
30 		self->ids  = 0;
31 		self->size = 1;
32 		self->id   = malloc(sizeof(u64));
33 		if (self->id == NULL) {
34 			free(self);
35 			self = NULL;
36 		}
37 	}
38 
39 	return self;
40 }
41 
42 void perf_header_attr__delete(struct perf_header_attr *self)
43 {
44 	free(self->id);
45 	free(self);
46 }
47 
48 int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
49 {
50 	int pos = self->ids;
51 
52 	self->ids++;
53 	if (self->ids > self->size) {
54 		int nsize = self->size * 2;
55 		u64 *nid = realloc(self->id, nsize * sizeof(u64));
56 
57 		if (nid == NULL)
58 			return -1;
59 
60 		self->size = nsize;
61 		self->id = nid;
62 	}
63 	self->id[pos] = id;
64 	return 0;
65 }
66 
67 int perf_header__init(struct perf_header *self)
68 {
69 	self->size = 1;
70 	self->attr = malloc(sizeof(void *));
71 	return self->attr == NULL ? -ENOMEM : 0;
72 }
73 
74 void perf_header__exit(struct perf_header *self)
75 {
76 	int i;
77 	for (i = 0; i < self->attrs; ++i)
78                 perf_header_attr__delete(self->attr[i]);
79 	free(self->attr);
80 }
81 
82 int perf_header__add_attr(struct perf_header *self,
83 			  struct perf_header_attr *attr)
84 {
85 	if (self->frozen)
86 		return -1;
87 
88 	if (self->attrs == self->size) {
89 		int nsize = self->size * 2;
90 		struct perf_header_attr **nattr;
91 
92 		nattr = realloc(self->attr, nsize * sizeof(void *));
93 		if (nattr == NULL)
94 			return -1;
95 
96 		self->size = nsize;
97 		self->attr = nattr;
98 	}
99 
100 	self->attr[self->attrs++] = attr;
101 	return 0;
102 }
103 
104 static int event_count;
105 static struct perf_trace_event_type *events;
106 
107 int perf_header__push_event(u64 id, const char *name)
108 {
109 	if (strlen(name) > MAX_EVENT_NAME)
110 		pr_warning("Event %s will be truncated\n", name);
111 
112 	if (!events) {
113 		events = malloc(sizeof(struct perf_trace_event_type));
114 		if (events == NULL)
115 			return -ENOMEM;
116 	} else {
117 		struct perf_trace_event_type *nevents;
118 
119 		nevents = realloc(events, (event_count + 1) * sizeof(*events));
120 		if (nevents == NULL)
121 			return -ENOMEM;
122 		events = nevents;
123 	}
124 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
125 	events[event_count].event_id = id;
126 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
127 	event_count++;
128 	return 0;
129 }
130 
131 char *perf_header__find_event(u64 id)
132 {
133 	int i;
134 	for (i = 0 ; i < event_count; i++) {
135 		if (events[i].event_id == id)
136 			return events[i].name;
137 	}
138 	return NULL;
139 }
140 
141 static const char *__perf_magic = "PERFFILE";
142 
143 #define PERF_MAGIC	(*(u64 *)__perf_magic)
144 
145 struct perf_file_attr {
146 	struct perf_event_attr	attr;
147 	struct perf_file_section	ids;
148 };
149 
150 void perf_header__set_feat(struct perf_header *self, int feat)
151 {
152 	set_bit(feat, self->adds_features);
153 }
154 
155 bool perf_header__has_feat(const struct perf_header *self, int feat)
156 {
157 	return test_bit(feat, self->adds_features);
158 }
159 
160 static int do_write(int fd, const void *buf, size_t size)
161 {
162 	while (size) {
163 		int ret = write(fd, buf, size);
164 
165 		if (ret < 0)
166 			return -errno;
167 
168 		size -= ret;
169 		buf += ret;
170 	}
171 
172 	return 0;
173 }
174 
175 #define NAME_ALIGN 64
176 
177 static int write_padded(int fd, const void *bf, size_t count,
178 			size_t count_aligned)
179 {
180 	static const char zero_buf[NAME_ALIGN];
181 	int err = do_write(fd, bf, count);
182 
183 	if (!err)
184 		err = do_write(fd, zero_buf, count_aligned - count);
185 
186 	return err;
187 }
188 
189 #define dsos__for_each_with_build_id(pos, head)	\
190 	list_for_each_entry(pos, head, node)	\
191 		if (!pos->has_build_id)		\
192 			continue;		\
193 		else
194 
195 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
196 				u16 misc, int fd)
197 {
198 	struct dso *pos;
199 
200 	dsos__for_each_with_build_id(pos, head) {
201 		int err;
202 		struct build_id_event b;
203 		size_t len;
204 
205 		if (!pos->hit)
206 			continue;
207 		len = pos->long_name_len + 1;
208 		len = ALIGN(len, NAME_ALIGN);
209 		memset(&b, 0, sizeof(b));
210 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
211 		b.pid = pid;
212 		b.header.misc = misc;
213 		b.header.size = sizeof(b) + len;
214 		err = do_write(fd, &b, sizeof(b));
215 		if (err < 0)
216 			return err;
217 		err = write_padded(fd, pos->long_name,
218 				   pos->long_name_len + 1, len);
219 		if (err < 0)
220 			return err;
221 	}
222 
223 	return 0;
224 }
225 
226 static int machine__write_buildid_table(struct machine *self, int fd)
227 {
228 	int err;
229 	u16 kmisc = PERF_RECORD_MISC_KERNEL,
230 	    umisc = PERF_RECORD_MISC_USER;
231 
232 	if (!machine__is_host(self)) {
233 		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
234 		umisc = PERF_RECORD_MISC_GUEST_USER;
235 	}
236 
237 	err = __dsos__write_buildid_table(&self->kernel_dsos, self->pid,
238 					  kmisc, fd);
239 	if (err == 0)
240 		err = __dsos__write_buildid_table(&self->user_dsos,
241 						  self->pid, umisc, fd);
242 	return err;
243 }
244 
245 static int dsos__write_buildid_table(struct perf_header *header, int fd)
246 {
247 	struct perf_session *session = container_of(header,
248 			struct perf_session, header);
249 	struct rb_node *nd;
250 	int err = machine__write_buildid_table(&session->host_machine, fd);
251 
252 	if (err)
253 		return err;
254 
255 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
256 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
257 		err = machine__write_buildid_table(pos, fd);
258 		if (err)
259 			break;
260 	}
261 	return err;
262 }
263 
264 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
265 			  const char *name, bool is_kallsyms)
266 {
267 	const size_t size = PATH_MAX;
268 	char *filename = malloc(size),
269 	     *linkname = malloc(size), *targetname;
270 	int len, err = -1;
271 
272 	if (filename == NULL || linkname == NULL)
273 		goto out_free;
274 
275 	len = snprintf(filename, size, "%s%s%s",
276 		       debugdir, is_kallsyms ? "/" : "", name);
277 	if (mkdir_p(filename, 0755))
278 		goto out_free;
279 
280 	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
281 
282 	if (access(filename, F_OK)) {
283 		if (is_kallsyms) {
284 			 if (copyfile("/proc/kallsyms", filename))
285 				goto out_free;
286 		} else if (link(name, filename) && copyfile(name, filename))
287 			goto out_free;
288 	}
289 
290 	len = snprintf(linkname, size, "%s/.build-id/%.2s",
291 		       debugdir, sbuild_id);
292 
293 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
294 		goto out_free;
295 
296 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
297 	targetname = filename + strlen(debugdir) - 5;
298 	memcpy(targetname, "../..", 5);
299 
300 	if (symlink(targetname, linkname) == 0)
301 		err = 0;
302 out_free:
303 	free(filename);
304 	free(linkname);
305 	return err;
306 }
307 
308 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
309 				 const char *name, const char *debugdir,
310 				 bool is_kallsyms)
311 {
312 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
313 
314 	build_id__sprintf(build_id, build_id_size, sbuild_id);
315 
316 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
317 }
318 
319 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
320 {
321 	const size_t size = PATH_MAX;
322 	char *filename = malloc(size),
323 	     *linkname = malloc(size);
324 	int err = -1;
325 
326 	if (filename == NULL || linkname == NULL)
327 		goto out_free;
328 
329 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
330 		 debugdir, sbuild_id, sbuild_id + 2);
331 
332 	if (access(linkname, F_OK))
333 		goto out_free;
334 
335 	if (readlink(linkname, filename, size) < 0)
336 		goto out_free;
337 
338 	if (unlink(linkname))
339 		goto out_free;
340 
341 	/*
342 	 * Since the link is relative, we must make it absolute:
343 	 */
344 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
345 		 debugdir, sbuild_id, filename);
346 
347 	if (unlink(linkname))
348 		goto out_free;
349 
350 	err = 0;
351 out_free:
352 	free(filename);
353 	free(linkname);
354 	return err;
355 }
356 
357 static int dso__cache_build_id(struct dso *self, const char *debugdir)
358 {
359 	bool is_kallsyms = self->kernel && self->long_name[0] != '/';
360 
361 	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
362 				     self->long_name, debugdir, is_kallsyms);
363 }
364 
365 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
366 {
367 	struct dso *pos;
368 	int err = 0;
369 
370 	dsos__for_each_with_build_id(pos, head)
371 		if (dso__cache_build_id(pos, debugdir))
372 			err = -1;
373 
374 	return err;
375 }
376 
377 static int machine__cache_build_ids(struct machine *self, const char *debugdir)
378 {
379 	int ret = __dsos__cache_build_ids(&self->kernel_dsos, debugdir);
380 	ret |= __dsos__cache_build_ids(&self->user_dsos, debugdir);
381 	return ret;
382 }
383 
384 static int perf_session__cache_build_ids(struct perf_session *self)
385 {
386 	struct rb_node *nd;
387 	int ret;
388 	char debugdir[PATH_MAX];
389 
390 	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
391 
392 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
393 		return -1;
394 
395 	ret = machine__cache_build_ids(&self->host_machine, debugdir);
396 
397 	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
398 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
399 		ret |= machine__cache_build_ids(pos, debugdir);
400 	}
401 	return ret ? -1 : 0;
402 }
403 
404 static bool machine__read_build_ids(struct machine *self, bool with_hits)
405 {
406 	bool ret = __dsos__read_build_ids(&self->kernel_dsos, with_hits);
407 	ret |= __dsos__read_build_ids(&self->user_dsos, with_hits);
408 	return ret;
409 }
410 
411 static bool perf_session__read_build_ids(struct perf_session *self, bool with_hits)
412 {
413 	struct rb_node *nd;
414 	bool ret = machine__read_build_ids(&self->host_machine, with_hits);
415 
416 	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
417 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
418 		ret |= machine__read_build_ids(pos, with_hits);
419 	}
420 
421 	return ret;
422 }
423 
424 static int perf_header__adds_write(struct perf_header *self, int fd)
425 {
426 	int nr_sections;
427 	struct perf_session *session;
428 	struct perf_file_section *feat_sec;
429 	int sec_size;
430 	u64 sec_start;
431 	int idx = 0, err;
432 
433 	session = container_of(self, struct perf_session, header);
434 	if (perf_session__read_build_ids(session, true))
435 		perf_header__set_feat(self, HEADER_BUILD_ID);
436 
437 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
438 	if (!nr_sections)
439 		return 0;
440 
441 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
442 	if (feat_sec == NULL)
443 		return -ENOMEM;
444 
445 	sec_size = sizeof(*feat_sec) * nr_sections;
446 
447 	sec_start = self->data_offset + self->data_size;
448 	lseek(fd, sec_start + sec_size, SEEK_SET);
449 
450 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
451 		struct perf_file_section *trace_sec;
452 
453 		trace_sec = &feat_sec[idx++];
454 
455 		/* Write trace info */
456 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
457 		read_tracing_data(fd, attrs, nr_counters);
458 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
459 	}
460 
461 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
462 		struct perf_file_section *buildid_sec;
463 
464 		buildid_sec = &feat_sec[idx++];
465 
466 		/* Write build-ids */
467 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
468 		err = dsos__write_buildid_table(self, fd);
469 		if (err < 0) {
470 			pr_debug("failed to write buildid table\n");
471 			goto out_free;
472 		}
473 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
474 					  buildid_sec->offset;
475 		if (!no_buildid_cache)
476 			perf_session__cache_build_ids(session);
477 	}
478 
479 	lseek(fd, sec_start, SEEK_SET);
480 	err = do_write(fd, feat_sec, sec_size);
481 	if (err < 0)
482 		pr_debug("failed to write feature section\n");
483 out_free:
484 	free(feat_sec);
485 	return err;
486 }
487 
488 int perf_header__write_pipe(int fd)
489 {
490 	struct perf_pipe_file_header f_header;
491 	int err;
492 
493 	f_header = (struct perf_pipe_file_header){
494 		.magic	   = PERF_MAGIC,
495 		.size	   = sizeof(f_header),
496 	};
497 
498 	err = do_write(fd, &f_header, sizeof(f_header));
499 	if (err < 0) {
500 		pr_debug("failed to write perf pipe header\n");
501 		return err;
502 	}
503 
504 	return 0;
505 }
506 
507 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
508 {
509 	struct perf_file_header f_header;
510 	struct perf_file_attr   f_attr;
511 	struct perf_header_attr	*attr;
512 	int i, err;
513 
514 	lseek(fd, sizeof(f_header), SEEK_SET);
515 
516 	for (i = 0; i < self->attrs; i++) {
517 		attr = self->attr[i];
518 
519 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
520 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
521 		if (err < 0) {
522 			pr_debug("failed to write perf header\n");
523 			return err;
524 		}
525 	}
526 
527 
528 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
529 
530 	for (i = 0; i < self->attrs; i++) {
531 		attr = self->attr[i];
532 
533 		f_attr = (struct perf_file_attr){
534 			.attr = attr->attr,
535 			.ids  = {
536 				.offset = attr->id_offset,
537 				.size   = attr->ids * sizeof(u64),
538 			}
539 		};
540 		err = do_write(fd, &f_attr, sizeof(f_attr));
541 		if (err < 0) {
542 			pr_debug("failed to write perf header attribute\n");
543 			return err;
544 		}
545 	}
546 
547 	self->event_offset = lseek(fd, 0, SEEK_CUR);
548 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
549 	if (events) {
550 		err = do_write(fd, events, self->event_size);
551 		if (err < 0) {
552 			pr_debug("failed to write perf header events\n");
553 			return err;
554 		}
555 	}
556 
557 	self->data_offset = lseek(fd, 0, SEEK_CUR);
558 
559 	if (at_exit) {
560 		err = perf_header__adds_write(self, fd);
561 		if (err < 0)
562 			return err;
563 	}
564 
565 	f_header = (struct perf_file_header){
566 		.magic	   = PERF_MAGIC,
567 		.size	   = sizeof(f_header),
568 		.attr_size = sizeof(f_attr),
569 		.attrs = {
570 			.offset = self->attr_offset,
571 			.size   = self->attrs * sizeof(f_attr),
572 		},
573 		.data = {
574 			.offset = self->data_offset,
575 			.size	= self->data_size,
576 		},
577 		.event_types = {
578 			.offset = self->event_offset,
579 			.size	= self->event_size,
580 		},
581 	};
582 
583 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
584 
585 	lseek(fd, 0, SEEK_SET);
586 	err = do_write(fd, &f_header, sizeof(f_header));
587 	if (err < 0) {
588 		pr_debug("failed to write perf header\n");
589 		return err;
590 	}
591 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
592 
593 	self->frozen = 1;
594 	return 0;
595 }
596 
597 static int perf_header__getbuffer64(struct perf_header *self,
598 				    int fd, void *buf, size_t size)
599 {
600 	if (do_read(fd, buf, size) <= 0)
601 		return -1;
602 
603 	if (self->needs_swap)
604 		mem_bswap_64(buf, size);
605 
606 	return 0;
607 }
608 
609 int perf_header__process_sections(struct perf_header *self, int fd,
610 				  int (*process)(struct perf_file_section *self,
611 						 struct perf_header *ph,
612 						 int feat, int fd))
613 {
614 	struct perf_file_section *feat_sec;
615 	int nr_sections;
616 	int sec_size;
617 	int idx = 0;
618 	int err = -1, feat = 1;
619 
620 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
621 	if (!nr_sections)
622 		return 0;
623 
624 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
625 	if (!feat_sec)
626 		return -1;
627 
628 	sec_size = sizeof(*feat_sec) * nr_sections;
629 
630 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
631 
632 	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
633 		goto out_free;
634 
635 	err = 0;
636 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
637 		if (perf_header__has_feat(self, feat)) {
638 			struct perf_file_section *sec = &feat_sec[idx++];
639 
640 			err = process(sec, self, feat, fd);
641 			if (err < 0)
642 				break;
643 		}
644 		++feat;
645 	}
646 out_free:
647 	free(feat_sec);
648 	return err;
649 }
650 
651 int perf_file_header__read(struct perf_file_header *self,
652 			   struct perf_header *ph, int fd)
653 {
654 	lseek(fd, 0, SEEK_SET);
655 
656 	if (do_read(fd, self, sizeof(*self)) <= 0 ||
657 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
658 		return -1;
659 
660 	if (self->attr_size != sizeof(struct perf_file_attr)) {
661 		u64 attr_size = bswap_64(self->attr_size);
662 
663 		if (attr_size != sizeof(struct perf_file_attr))
664 			return -1;
665 
666 		mem_bswap_64(self, offsetof(struct perf_file_header,
667 					    adds_features));
668 		ph->needs_swap = true;
669 	}
670 
671 	if (self->size != sizeof(*self)) {
672 		/* Support the previous format */
673 		if (self->size == offsetof(typeof(*self), adds_features))
674 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
675 		else
676 			return -1;
677 	}
678 
679 	memcpy(&ph->adds_features, &self->adds_features,
680 	       sizeof(ph->adds_features));
681 	/*
682 	 * FIXME: hack that assumes that if we need swap the perf.data file
683 	 * may be coming from an arch with a different word-size, ergo different
684 	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
685 	 * safe to assume that we have a build-id section. Trace files probably
686 	 * have several other issues in this realm anyway...
687 	 */
688 	if (ph->needs_swap) {
689 		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
690 		perf_header__set_feat(ph, HEADER_BUILD_ID);
691 	}
692 
693 	ph->event_offset = self->event_types.offset;
694 	ph->event_size   = self->event_types.size;
695 	ph->data_offset  = self->data.offset;
696 	ph->data_size	 = self->data.size;
697 	return 0;
698 }
699 
700 static int __event_process_build_id(struct build_id_event *bev,
701 				    char *filename,
702 				    struct perf_session *session)
703 {
704 	int err = -1;
705 	struct list_head *head;
706 	struct machine *machine;
707 	u16 misc;
708 	struct dso *dso;
709 	enum dso_kernel_type dso_type;
710 
711 	machine = perf_session__findnew_machine(session, bev->pid);
712 	if (!machine)
713 		goto out;
714 
715 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
716 
717 	switch (misc) {
718 	case PERF_RECORD_MISC_KERNEL:
719 		dso_type = DSO_TYPE_KERNEL;
720 		head = &machine->kernel_dsos;
721 		break;
722 	case PERF_RECORD_MISC_GUEST_KERNEL:
723 		dso_type = DSO_TYPE_GUEST_KERNEL;
724 		head = &machine->kernel_dsos;
725 		break;
726 	case PERF_RECORD_MISC_USER:
727 	case PERF_RECORD_MISC_GUEST_USER:
728 		dso_type = DSO_TYPE_USER;
729 		head = &machine->user_dsos;
730 		break;
731 	default:
732 		goto out;
733 	}
734 
735 	dso = __dsos__findnew(head, filename);
736 	if (dso != NULL) {
737 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
738 
739 		dso__set_build_id(dso, &bev->build_id);
740 
741 		if (filename[0] == '[')
742 			dso->kernel = dso_type;
743 
744 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
745 				  sbuild_id);
746 		pr_debug("build id event received for %s: %s\n",
747 			 dso->long_name, sbuild_id);
748 	}
749 
750 	err = 0;
751 out:
752 	return err;
753 }
754 
755 static int perf_header__read_build_ids(struct perf_header *self,
756 			int input, u64 offset, u64 size)
757 {
758 	struct perf_session *session = container_of(self,
759 			struct perf_session, header);
760 	struct build_id_event bev;
761 	char filename[PATH_MAX];
762 	u64 limit = offset + size;
763 	int err = -1;
764 
765 	while (offset < limit) {
766 		ssize_t len;
767 
768 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
769 			goto out;
770 
771 		if (self->needs_swap)
772 			perf_event_header__bswap(&bev.header);
773 
774 		len = bev.header.size - sizeof(bev);
775 		if (read(input, filename, len) != len)
776 			goto out;
777 
778 		__event_process_build_id(&bev, filename, session);
779 
780 		offset += bev.header.size;
781 	}
782 	err = 0;
783 out:
784 	return err;
785 }
786 
787 static int perf_file_section__process(struct perf_file_section *self,
788 				      struct perf_header *ph,
789 				      int feat, int fd)
790 {
791 	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
792 		pr_debug("Failed to lseek to %Ld offset for feature %d, "
793 			 "continuing...\n", self->offset, feat);
794 		return 0;
795 	}
796 
797 	switch (feat) {
798 	case HEADER_TRACE_INFO:
799 		trace_report(fd, false);
800 		break;
801 
802 	case HEADER_BUILD_ID:
803 		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
804 			pr_debug("Failed to read buildids, continuing...\n");
805 		break;
806 	default:
807 		pr_debug("unknown feature %d, continuing...\n", feat);
808 	}
809 
810 	return 0;
811 }
812 
813 static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
814 				       struct perf_header *ph, int fd,
815 				       bool repipe)
816 {
817 	if (do_read(fd, self, sizeof(*self)) <= 0 ||
818 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
819 		return -1;
820 
821 	if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
822 		return -1;
823 
824 	if (self->size != sizeof(*self)) {
825 		u64 size = bswap_64(self->size);
826 
827 		if (size != sizeof(*self))
828 			return -1;
829 
830 		ph->needs_swap = true;
831 	}
832 
833 	return 0;
834 }
835 
836 static int perf_header__read_pipe(struct perf_session *session, int fd)
837 {
838 	struct perf_header *self = &session->header;
839 	struct perf_pipe_file_header f_header;
840 
841 	if (perf_file_header__read_pipe(&f_header, self, fd,
842 					session->repipe) < 0) {
843 		pr_debug("incompatible file format\n");
844 		return -EINVAL;
845 	}
846 
847 	session->fd = fd;
848 
849 	return 0;
850 }
851 
852 int perf_header__read(struct perf_session *session, int fd)
853 {
854 	struct perf_header *self = &session->header;
855 	struct perf_file_header	f_header;
856 	struct perf_file_attr	f_attr;
857 	u64			f_id;
858 	int nr_attrs, nr_ids, i, j;
859 
860 	if (session->fd_pipe)
861 		return perf_header__read_pipe(session, fd);
862 
863 	if (perf_file_header__read(&f_header, self, fd) < 0) {
864 		pr_debug("incompatible file format\n");
865 		return -EINVAL;
866 	}
867 
868 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
869 	lseek(fd, f_header.attrs.offset, SEEK_SET);
870 
871 	for (i = 0; i < nr_attrs; i++) {
872 		struct perf_header_attr *attr;
873 		off_t tmp;
874 
875 		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
876 			goto out_errno;
877 
878 		tmp = lseek(fd, 0, SEEK_CUR);
879 
880 		attr = perf_header_attr__new(&f_attr.attr);
881 		if (attr == NULL)
882 			 return -ENOMEM;
883 
884 		nr_ids = f_attr.ids.size / sizeof(u64);
885 		lseek(fd, f_attr.ids.offset, SEEK_SET);
886 
887 		for (j = 0; j < nr_ids; j++) {
888 			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
889 				goto out_errno;
890 
891 			if (perf_header_attr__add_id(attr, f_id) < 0) {
892 				perf_header_attr__delete(attr);
893 				return -ENOMEM;
894 			}
895 		}
896 		if (perf_header__add_attr(self, attr) < 0) {
897 			perf_header_attr__delete(attr);
898 			return -ENOMEM;
899 		}
900 
901 		lseek(fd, tmp, SEEK_SET);
902 	}
903 
904 	if (f_header.event_types.size) {
905 		lseek(fd, f_header.event_types.offset, SEEK_SET);
906 		events = malloc(f_header.event_types.size);
907 		if (events == NULL)
908 			return -ENOMEM;
909 		if (perf_header__getbuffer64(self, fd, events,
910 					     f_header.event_types.size))
911 			goto out_errno;
912 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
913 	}
914 
915 	perf_header__process_sections(self, fd, perf_file_section__process);
916 
917 	lseek(fd, self->data_offset, SEEK_SET);
918 
919 	self->frozen = 1;
920 	return 0;
921 out_errno:
922 	return -errno;
923 }
924 
925 u64 perf_header__sample_type(struct perf_header *header)
926 {
927 	u64 type = 0;
928 	int i;
929 
930 	for (i = 0; i < header->attrs; i++) {
931 		struct perf_header_attr *attr = header->attr[i];
932 
933 		if (!type)
934 			type = attr->attr.sample_type;
935 		else if (type != attr->attr.sample_type)
936 			die("non matching sample_type");
937 	}
938 
939 	return type;
940 }
941 
942 struct perf_event_attr *
943 perf_header__find_attr(u64 id, struct perf_header *header)
944 {
945 	int i;
946 
947 	/*
948 	 * We set id to -1 if the data file doesn't contain sample
949 	 * ids. Check for this and avoid walking through the entire
950 	 * list of ids which may be large.
951 	 */
952 	if (id == -1ULL)
953 		return NULL;
954 
955 	for (i = 0; i < header->attrs; i++) {
956 		struct perf_header_attr *attr = header->attr[i];
957 		int j;
958 
959 		for (j = 0; j < attr->ids; j++) {
960 			if (attr->id[j] == id)
961 				return &attr->attr;
962 		}
963 	}
964 
965 	return NULL;
966 }
967 
968 int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
969 			   event__handler_t process,
970 			   struct perf_session *session)
971 {
972 	event_t *ev;
973 	size_t size;
974 	int err;
975 
976 	size = sizeof(struct perf_event_attr);
977 	size = ALIGN(size, sizeof(u64));
978 	size += sizeof(struct perf_event_header);
979 	size += ids * sizeof(u64);
980 
981 	ev = malloc(size);
982 
983 	ev->attr.attr = *attr;
984 	memcpy(ev->attr.id, id, ids * sizeof(u64));
985 
986 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
987 	ev->attr.header.size = size;
988 
989 	err = process(ev, session);
990 
991 	free(ev);
992 
993 	return err;
994 }
995 
996 int event__synthesize_attrs(struct perf_header *self,
997 			    event__handler_t process,
998 			    struct perf_session *session)
999 {
1000 	struct perf_header_attr	*attr;
1001 	int i, err = 0;
1002 
1003 	for (i = 0; i < self->attrs; i++) {
1004 		attr = self->attr[i];
1005 
1006 		err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
1007 					     process, session);
1008 		if (err) {
1009 			pr_debug("failed to create perf header attribute\n");
1010 			return err;
1011 		}
1012 	}
1013 
1014 	return err;
1015 }
1016 
1017 int event__process_attr(event_t *self, struct perf_session *session)
1018 {
1019 	struct perf_header_attr *attr;
1020 	unsigned int i, ids, n_ids;
1021 
1022 	attr = perf_header_attr__new(&self->attr.attr);
1023 	if (attr == NULL)
1024 		return -ENOMEM;
1025 
1026 	ids = self->header.size;
1027 	ids -= (void *)&self->attr.id - (void *)self;
1028 	n_ids = ids / sizeof(u64);
1029 
1030 	for (i = 0; i < n_ids; i++) {
1031 		if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
1032 			perf_header_attr__delete(attr);
1033 			return -ENOMEM;
1034 		}
1035 	}
1036 
1037 	if (perf_header__add_attr(&session->header, attr) < 0) {
1038 		perf_header_attr__delete(attr);
1039 		return -ENOMEM;
1040 	}
1041 
1042 	perf_session__update_sample_type(session);
1043 
1044 	return 0;
1045 }
1046 
1047 int event__synthesize_event_type(u64 event_id, char *name,
1048 				 event__handler_t process,
1049 				 struct perf_session *session)
1050 {
1051 	event_t ev;
1052 	size_t size = 0;
1053 	int err = 0;
1054 
1055 	memset(&ev, 0, sizeof(ev));
1056 
1057 	ev.event_type.event_type.event_id = event_id;
1058 	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
1059 	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
1060 
1061 	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
1062 	size = strlen(name);
1063 	size = ALIGN(size, sizeof(u64));
1064 	ev.event_type.header.size = sizeof(ev.event_type) -
1065 		(sizeof(ev.event_type.event_type.name) - size);
1066 
1067 	err = process(&ev, session);
1068 
1069 	return err;
1070 }
1071 
1072 int event__synthesize_event_types(event__handler_t process,
1073 				  struct perf_session *session)
1074 {
1075 	struct perf_trace_event_type *type;
1076 	int i, err = 0;
1077 
1078 	for (i = 0; i < event_count; i++) {
1079 		type = &events[i];
1080 
1081 		err = event__synthesize_event_type(type->event_id, type->name,
1082 						   process, session);
1083 		if (err) {
1084 			pr_debug("failed to create perf header event type\n");
1085 			return err;
1086 		}
1087 	}
1088 
1089 	return err;
1090 }
1091 
1092 int event__process_event_type(event_t *self,
1093 			      struct perf_session *session __unused)
1094 {
1095 	if (perf_header__push_event(self->event_type.event_type.event_id,
1096 				    self->event_type.event_type.name) < 0)
1097 		return -ENOMEM;
1098 
1099 	return 0;
1100 }
1101 
1102 int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
1103 				   int nb_events,
1104 				   event__handler_t process,
1105 				   struct perf_session *session __unused)
1106 {
1107 	event_t ev;
1108 	ssize_t size = 0, aligned_size = 0, padding;
1109 	int err = 0;
1110 
1111 	memset(&ev, 0, sizeof(ev));
1112 
1113 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
1114 	size = read_tracing_data_size(fd, pattrs, nb_events);
1115 	if (size <= 0)
1116 		return size;
1117 	aligned_size = ALIGN(size, sizeof(u64));
1118 	padding = aligned_size - size;
1119 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
1120 	ev.tracing_data.size = aligned_size;
1121 
1122 	process(&ev, session);
1123 
1124 	err = read_tracing_data(fd, pattrs, nb_events);
1125 	write_padded(fd, NULL, 0, padding);
1126 
1127 	return aligned_size;
1128 }
1129 
1130 int event__process_tracing_data(event_t *self,
1131 				struct perf_session *session)
1132 {
1133 	ssize_t size_read, padding, size = self->tracing_data.size;
1134 	off_t offset = lseek(session->fd, 0, SEEK_CUR);
1135 	char buf[BUFSIZ];
1136 
1137 	/* setup for reading amidst mmap */
1138 	lseek(session->fd, offset + sizeof(struct tracing_data_event),
1139 	      SEEK_SET);
1140 
1141 	size_read = trace_report(session->fd, session->repipe);
1142 
1143 	padding = ALIGN(size_read, sizeof(u64)) - size_read;
1144 
1145 	if (read(session->fd, buf, padding) < 0)
1146 		die("reading input file");
1147 	if (session->repipe) {
1148 		int retw = write(STDOUT_FILENO, buf, padding);
1149 		if (retw <= 0 || retw != padding)
1150 			die("repiping tracing data padding");
1151 	}
1152 
1153 	if (size_read + padding != size)
1154 		die("tracing data size mismatch");
1155 
1156 	return size_read + padding;
1157 }
1158 
1159 int event__synthesize_build_id(struct dso *pos, u16 misc,
1160 			       event__handler_t process,
1161 			       struct machine *machine,
1162 			       struct perf_session *session)
1163 {
1164 	event_t ev;
1165 	size_t len;
1166 	int err = 0;
1167 
1168 	if (!pos->hit)
1169 		return err;
1170 
1171 	memset(&ev, 0, sizeof(ev));
1172 
1173 	len = pos->long_name_len + 1;
1174 	len = ALIGN(len, NAME_ALIGN);
1175 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
1176 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
1177 	ev.build_id.header.misc = misc;
1178 	ev.build_id.pid = machine->pid;
1179 	ev.build_id.header.size = sizeof(ev.build_id) + len;
1180 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
1181 
1182 	err = process(&ev, session);
1183 
1184 	return err;
1185 }
1186 
1187 int event__process_build_id(event_t *self,
1188 			    struct perf_session *session)
1189 {
1190 	__event_process_build_id(&self->build_id,
1191 				 self->build_id.filename,
1192 				 session);
1193 	return 0;
1194 }
1195 
1196 void disable_buildid_cache(void)
1197 {
1198 	no_buildid_cache = true;
1199 }
1200