xref: /openbmc/linux/tools/perf/util/header.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 void perf_header__clear_feat(struct perf_header *self, int feat)
156 {
157 	clear_bit(feat, self->adds_features);
158 }
159 
160 bool perf_header__has_feat(const struct perf_header *self, int feat)
161 {
162 	return test_bit(feat, self->adds_features);
163 }
164 
165 static int do_write(int fd, const void *buf, size_t size)
166 {
167 	while (size) {
168 		int ret = write(fd, buf, size);
169 
170 		if (ret < 0)
171 			return -errno;
172 
173 		size -= ret;
174 		buf += ret;
175 	}
176 
177 	return 0;
178 }
179 
180 #define NAME_ALIGN 64
181 
182 static int write_padded(int fd, const void *bf, size_t count,
183 			size_t count_aligned)
184 {
185 	static const char zero_buf[NAME_ALIGN];
186 	int err = do_write(fd, bf, count);
187 
188 	if (!err)
189 		err = do_write(fd, zero_buf, count_aligned - count);
190 
191 	return err;
192 }
193 
194 #define dsos__for_each_with_build_id(pos, head)	\
195 	list_for_each_entry(pos, head, node)	\
196 		if (!pos->has_build_id)		\
197 			continue;		\
198 		else
199 
200 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
201 				u16 misc, int fd)
202 {
203 	struct dso *pos;
204 
205 	dsos__for_each_with_build_id(pos, head) {
206 		int err;
207 		struct build_id_event b;
208 		size_t len;
209 
210 		if (!pos->hit)
211 			continue;
212 		len = pos->long_name_len + 1;
213 		len = ALIGN(len, NAME_ALIGN);
214 		memset(&b, 0, sizeof(b));
215 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
216 		b.pid = pid;
217 		b.header.misc = misc;
218 		b.header.size = sizeof(b) + len;
219 		err = do_write(fd, &b, sizeof(b));
220 		if (err < 0)
221 			return err;
222 		err = write_padded(fd, pos->long_name,
223 				   pos->long_name_len + 1, len);
224 		if (err < 0)
225 			return err;
226 	}
227 
228 	return 0;
229 }
230 
231 static int machine__write_buildid_table(struct machine *self, int fd)
232 {
233 	int err;
234 	u16 kmisc = PERF_RECORD_MISC_KERNEL,
235 	    umisc = PERF_RECORD_MISC_USER;
236 
237 	if (!machine__is_host(self)) {
238 		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
239 		umisc = PERF_RECORD_MISC_GUEST_USER;
240 	}
241 
242 	err = __dsos__write_buildid_table(&self->kernel_dsos, self->pid,
243 					  kmisc, fd);
244 	if (err == 0)
245 		err = __dsos__write_buildid_table(&self->user_dsos,
246 						  self->pid, umisc, fd);
247 	return err;
248 }
249 
250 static int dsos__write_buildid_table(struct perf_header *header, int fd)
251 {
252 	struct perf_session *session = container_of(header,
253 			struct perf_session, header);
254 	struct rb_node *nd;
255 	int err = machine__write_buildid_table(&session->host_machine, fd);
256 
257 	if (err)
258 		return err;
259 
260 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
261 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
262 		err = machine__write_buildid_table(pos, fd);
263 		if (err)
264 			break;
265 	}
266 	return err;
267 }
268 
269 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
270 			  const char *name, bool is_kallsyms)
271 {
272 	const size_t size = PATH_MAX;
273 	char *realname = realpath(name, NULL),
274 	     *filename = malloc(size),
275 	     *linkname = malloc(size), *targetname;
276 	int len, err = -1;
277 
278 	if (realname == NULL || filename == NULL || linkname == NULL)
279 		goto out_free;
280 
281 	len = snprintf(filename, size, "%s%s%s",
282 		       debugdir, is_kallsyms ? "/" : "", realname);
283 	if (mkdir_p(filename, 0755))
284 		goto out_free;
285 
286 	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
287 
288 	if (access(filename, F_OK)) {
289 		if (is_kallsyms) {
290 			 if (copyfile("/proc/kallsyms", filename))
291 				goto out_free;
292 		} else if (link(realname, filename) && copyfile(name, filename))
293 			goto out_free;
294 	}
295 
296 	len = snprintf(linkname, size, "%s/.build-id/%.2s",
297 		       debugdir, sbuild_id);
298 
299 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
300 		goto out_free;
301 
302 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
303 	targetname = filename + strlen(debugdir) - 5;
304 	memcpy(targetname, "../..", 5);
305 
306 	if (symlink(targetname, linkname) == 0)
307 		err = 0;
308 out_free:
309 	free(realname);
310 	free(filename);
311 	free(linkname);
312 	return err;
313 }
314 
315 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
316 				 const char *name, const char *debugdir,
317 				 bool is_kallsyms)
318 {
319 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
320 
321 	build_id__sprintf(build_id, build_id_size, sbuild_id);
322 
323 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
324 }
325 
326 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
327 {
328 	const size_t size = PATH_MAX;
329 	char *filename = malloc(size),
330 	     *linkname = malloc(size);
331 	int err = -1;
332 
333 	if (filename == NULL || linkname == NULL)
334 		goto out_free;
335 
336 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
337 		 debugdir, sbuild_id, sbuild_id + 2);
338 
339 	if (access(linkname, F_OK))
340 		goto out_free;
341 
342 	if (readlink(linkname, filename, size) < 0)
343 		goto out_free;
344 
345 	if (unlink(linkname))
346 		goto out_free;
347 
348 	/*
349 	 * Since the link is relative, we must make it absolute:
350 	 */
351 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
352 		 debugdir, sbuild_id, filename);
353 
354 	if (unlink(linkname))
355 		goto out_free;
356 
357 	err = 0;
358 out_free:
359 	free(filename);
360 	free(linkname);
361 	return err;
362 }
363 
364 static int dso__cache_build_id(struct dso *self, const char *debugdir)
365 {
366 	bool is_kallsyms = self->kernel && self->long_name[0] != '/';
367 
368 	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
369 				     self->long_name, debugdir, is_kallsyms);
370 }
371 
372 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
373 {
374 	struct dso *pos;
375 	int err = 0;
376 
377 	dsos__for_each_with_build_id(pos, head)
378 		if (dso__cache_build_id(pos, debugdir))
379 			err = -1;
380 
381 	return err;
382 }
383 
384 static int machine__cache_build_ids(struct machine *self, const char *debugdir)
385 {
386 	int ret = __dsos__cache_build_ids(&self->kernel_dsos, debugdir);
387 	ret |= __dsos__cache_build_ids(&self->user_dsos, debugdir);
388 	return ret;
389 }
390 
391 static int perf_session__cache_build_ids(struct perf_session *self)
392 {
393 	struct rb_node *nd;
394 	int ret;
395 	char debugdir[PATH_MAX];
396 
397 	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
398 
399 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
400 		return -1;
401 
402 	ret = machine__cache_build_ids(&self->host_machine, debugdir);
403 
404 	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
405 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
406 		ret |= machine__cache_build_ids(pos, debugdir);
407 	}
408 	return ret ? -1 : 0;
409 }
410 
411 static bool machine__read_build_ids(struct machine *self, bool with_hits)
412 {
413 	bool ret = __dsos__read_build_ids(&self->kernel_dsos, with_hits);
414 	ret |= __dsos__read_build_ids(&self->user_dsos, with_hits);
415 	return ret;
416 }
417 
418 static bool perf_session__read_build_ids(struct perf_session *self, bool with_hits)
419 {
420 	struct rb_node *nd;
421 	bool ret = machine__read_build_ids(&self->host_machine, with_hits);
422 
423 	for (nd = rb_first(&self->machines); nd; nd = rb_next(nd)) {
424 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
425 		ret |= machine__read_build_ids(pos, with_hits);
426 	}
427 
428 	return ret;
429 }
430 
431 static int perf_header__adds_write(struct perf_header *self, int fd)
432 {
433 	int nr_sections;
434 	struct perf_session *session;
435 	struct perf_file_section *feat_sec;
436 	int sec_size;
437 	u64 sec_start;
438 	int idx = 0, err;
439 
440 	session = container_of(self, struct perf_session, header);
441 
442 	if (perf_header__has_feat(self, HEADER_BUILD_ID &&
443 	    !perf_session__read_build_ids(session, true)))
444 		perf_header__clear_feat(self, HEADER_BUILD_ID);
445 
446 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
447 	if (!nr_sections)
448 		return 0;
449 
450 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
451 	if (feat_sec == NULL)
452 		return -ENOMEM;
453 
454 	sec_size = sizeof(*feat_sec) * nr_sections;
455 
456 	sec_start = self->data_offset + self->data_size;
457 	lseek(fd, sec_start + sec_size, SEEK_SET);
458 
459 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
460 		struct perf_file_section *trace_sec;
461 
462 		trace_sec = &feat_sec[idx++];
463 
464 		/* Write trace info */
465 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
466 		read_tracing_data(fd, &evsel_list);
467 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
468 	}
469 
470 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
471 		struct perf_file_section *buildid_sec;
472 
473 		buildid_sec = &feat_sec[idx++];
474 
475 		/* Write build-ids */
476 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
477 		err = dsos__write_buildid_table(self, fd);
478 		if (err < 0) {
479 			pr_debug("failed to write buildid table\n");
480 			goto out_free;
481 		}
482 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
483 					  buildid_sec->offset;
484 		if (!no_buildid_cache)
485 			perf_session__cache_build_ids(session);
486 	}
487 
488 	lseek(fd, sec_start, SEEK_SET);
489 	err = do_write(fd, feat_sec, sec_size);
490 	if (err < 0)
491 		pr_debug("failed to write feature section\n");
492 out_free:
493 	free(feat_sec);
494 	return err;
495 }
496 
497 int perf_header__write_pipe(int fd)
498 {
499 	struct perf_pipe_file_header f_header;
500 	int err;
501 
502 	f_header = (struct perf_pipe_file_header){
503 		.magic	   = PERF_MAGIC,
504 		.size	   = sizeof(f_header),
505 	};
506 
507 	err = do_write(fd, &f_header, sizeof(f_header));
508 	if (err < 0) {
509 		pr_debug("failed to write perf pipe header\n");
510 		return err;
511 	}
512 
513 	return 0;
514 }
515 
516 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
517 {
518 	struct perf_file_header f_header;
519 	struct perf_file_attr   f_attr;
520 	struct perf_header_attr	*attr;
521 	int i, err;
522 
523 	lseek(fd, sizeof(f_header), SEEK_SET);
524 
525 	for (i = 0; i < self->attrs; i++) {
526 		attr = self->attr[i];
527 
528 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
529 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
530 		if (err < 0) {
531 			pr_debug("failed to write perf header\n");
532 			return err;
533 		}
534 	}
535 
536 
537 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
538 
539 	for (i = 0; i < self->attrs; i++) {
540 		attr = self->attr[i];
541 
542 		f_attr = (struct perf_file_attr){
543 			.attr = attr->attr,
544 			.ids  = {
545 				.offset = attr->id_offset,
546 				.size   = attr->ids * sizeof(u64),
547 			}
548 		};
549 		err = do_write(fd, &f_attr, sizeof(f_attr));
550 		if (err < 0) {
551 			pr_debug("failed to write perf header attribute\n");
552 			return err;
553 		}
554 	}
555 
556 	self->event_offset = lseek(fd, 0, SEEK_CUR);
557 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
558 	if (events) {
559 		err = do_write(fd, events, self->event_size);
560 		if (err < 0) {
561 			pr_debug("failed to write perf header events\n");
562 			return err;
563 		}
564 	}
565 
566 	self->data_offset = lseek(fd, 0, SEEK_CUR);
567 
568 	if (at_exit) {
569 		err = perf_header__adds_write(self, fd);
570 		if (err < 0)
571 			return err;
572 	}
573 
574 	f_header = (struct perf_file_header){
575 		.magic	   = PERF_MAGIC,
576 		.size	   = sizeof(f_header),
577 		.attr_size = sizeof(f_attr),
578 		.attrs = {
579 			.offset = self->attr_offset,
580 			.size   = self->attrs * sizeof(f_attr),
581 		},
582 		.data = {
583 			.offset = self->data_offset,
584 			.size	= self->data_size,
585 		},
586 		.event_types = {
587 			.offset = self->event_offset,
588 			.size	= self->event_size,
589 		},
590 	};
591 
592 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
593 
594 	lseek(fd, 0, SEEK_SET);
595 	err = do_write(fd, &f_header, sizeof(f_header));
596 	if (err < 0) {
597 		pr_debug("failed to write perf header\n");
598 		return err;
599 	}
600 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
601 
602 	self->frozen = 1;
603 	return 0;
604 }
605 
606 static int perf_header__getbuffer64(struct perf_header *self,
607 				    int fd, void *buf, size_t size)
608 {
609 	if (readn(fd, buf, size) <= 0)
610 		return -1;
611 
612 	if (self->needs_swap)
613 		mem_bswap_64(buf, size);
614 
615 	return 0;
616 }
617 
618 int perf_header__process_sections(struct perf_header *self, int fd,
619 				  int (*process)(struct perf_file_section *self,
620 						 struct perf_header *ph,
621 						 int feat, int fd))
622 {
623 	struct perf_file_section *feat_sec;
624 	int nr_sections;
625 	int sec_size;
626 	int idx = 0;
627 	int err = -1, feat = 1;
628 
629 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
630 	if (!nr_sections)
631 		return 0;
632 
633 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
634 	if (!feat_sec)
635 		return -1;
636 
637 	sec_size = sizeof(*feat_sec) * nr_sections;
638 
639 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
640 
641 	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
642 		goto out_free;
643 
644 	err = 0;
645 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
646 		if (perf_header__has_feat(self, feat)) {
647 			struct perf_file_section *sec = &feat_sec[idx++];
648 
649 			err = process(sec, self, feat, fd);
650 			if (err < 0)
651 				break;
652 		}
653 		++feat;
654 	}
655 out_free:
656 	free(feat_sec);
657 	return err;
658 }
659 
660 int perf_file_header__read(struct perf_file_header *self,
661 			   struct perf_header *ph, int fd)
662 {
663 	lseek(fd, 0, SEEK_SET);
664 
665 	if (readn(fd, self, sizeof(*self)) <= 0 ||
666 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
667 		return -1;
668 
669 	if (self->attr_size != sizeof(struct perf_file_attr)) {
670 		u64 attr_size = bswap_64(self->attr_size);
671 
672 		if (attr_size != sizeof(struct perf_file_attr))
673 			return -1;
674 
675 		mem_bswap_64(self, offsetof(struct perf_file_header,
676 					    adds_features));
677 		ph->needs_swap = true;
678 	}
679 
680 	if (self->size != sizeof(*self)) {
681 		/* Support the previous format */
682 		if (self->size == offsetof(typeof(*self), adds_features))
683 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
684 		else
685 			return -1;
686 	}
687 
688 	memcpy(&ph->adds_features, &self->adds_features,
689 	       sizeof(ph->adds_features));
690 	/*
691 	 * FIXME: hack that assumes that if we need swap the perf.data file
692 	 * may be coming from an arch with a different word-size, ergo different
693 	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
694 	 * safe to assume that we have a build-id section. Trace files probably
695 	 * have several other issues in this realm anyway...
696 	 */
697 	if (ph->needs_swap) {
698 		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
699 		perf_header__set_feat(ph, HEADER_BUILD_ID);
700 	}
701 
702 	ph->event_offset = self->event_types.offset;
703 	ph->event_size   = self->event_types.size;
704 	ph->data_offset  = self->data.offset;
705 	ph->data_size	 = self->data.size;
706 	return 0;
707 }
708 
709 static int __event_process_build_id(struct build_id_event *bev,
710 				    char *filename,
711 				    struct perf_session *session)
712 {
713 	int err = -1;
714 	struct list_head *head;
715 	struct machine *machine;
716 	u16 misc;
717 	struct dso *dso;
718 	enum dso_kernel_type dso_type;
719 
720 	machine = perf_session__findnew_machine(session, bev->pid);
721 	if (!machine)
722 		goto out;
723 
724 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
725 
726 	switch (misc) {
727 	case PERF_RECORD_MISC_KERNEL:
728 		dso_type = DSO_TYPE_KERNEL;
729 		head = &machine->kernel_dsos;
730 		break;
731 	case PERF_RECORD_MISC_GUEST_KERNEL:
732 		dso_type = DSO_TYPE_GUEST_KERNEL;
733 		head = &machine->kernel_dsos;
734 		break;
735 	case PERF_RECORD_MISC_USER:
736 	case PERF_RECORD_MISC_GUEST_USER:
737 		dso_type = DSO_TYPE_USER;
738 		head = &machine->user_dsos;
739 		break;
740 	default:
741 		goto out;
742 	}
743 
744 	dso = __dsos__findnew(head, filename);
745 	if (dso != NULL) {
746 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
747 
748 		dso__set_build_id(dso, &bev->build_id);
749 
750 		if (filename[0] == '[')
751 			dso->kernel = dso_type;
752 
753 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
754 				  sbuild_id);
755 		pr_debug("build id event received for %s: %s\n",
756 			 dso->long_name, sbuild_id);
757 	}
758 
759 	err = 0;
760 out:
761 	return err;
762 }
763 
764 static int perf_header__read_build_ids(struct perf_header *self,
765 			int input, u64 offset, u64 size)
766 {
767 	struct perf_session *session = container_of(self,
768 			struct perf_session, header);
769 	struct build_id_event bev;
770 	char filename[PATH_MAX];
771 	u64 limit = offset + size;
772 	int err = -1;
773 
774 	while (offset < limit) {
775 		ssize_t len;
776 
777 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
778 			goto out;
779 
780 		if (self->needs_swap)
781 			perf_event_header__bswap(&bev.header);
782 
783 		len = bev.header.size - sizeof(bev);
784 		if (read(input, filename, len) != len)
785 			goto out;
786 
787 		__event_process_build_id(&bev, filename, session);
788 
789 		offset += bev.header.size;
790 	}
791 	err = 0;
792 out:
793 	return err;
794 }
795 
796 static int perf_file_section__process(struct perf_file_section *self,
797 				      struct perf_header *ph,
798 				      int feat, int fd)
799 {
800 	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
801 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
802 			  "%d, continuing...\n", self->offset, feat);
803 		return 0;
804 	}
805 
806 	switch (feat) {
807 	case HEADER_TRACE_INFO:
808 		trace_report(fd, false);
809 		break;
810 
811 	case HEADER_BUILD_ID:
812 		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
813 			pr_debug("Failed to read buildids, continuing...\n");
814 		break;
815 	default:
816 		pr_debug("unknown feature %d, continuing...\n", feat);
817 	}
818 
819 	return 0;
820 }
821 
822 static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
823 				       struct perf_header *ph, int fd,
824 				       bool repipe)
825 {
826 	if (readn(fd, self, sizeof(*self)) <= 0 ||
827 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
828 		return -1;
829 
830 	if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
831 		return -1;
832 
833 	if (self->size != sizeof(*self)) {
834 		u64 size = bswap_64(self->size);
835 
836 		if (size != sizeof(*self))
837 			return -1;
838 
839 		ph->needs_swap = true;
840 	}
841 
842 	return 0;
843 }
844 
845 static int perf_header__read_pipe(struct perf_session *session, int fd)
846 {
847 	struct perf_header *self = &session->header;
848 	struct perf_pipe_file_header f_header;
849 
850 	if (perf_file_header__read_pipe(&f_header, self, fd,
851 					session->repipe) < 0) {
852 		pr_debug("incompatible file format\n");
853 		return -EINVAL;
854 	}
855 
856 	session->fd = fd;
857 
858 	return 0;
859 }
860 
861 int perf_header__read(struct perf_session *session, int fd)
862 {
863 	struct perf_header *self = &session->header;
864 	struct perf_file_header	f_header;
865 	struct perf_file_attr	f_attr;
866 	u64			f_id;
867 	int nr_attrs, nr_ids, i, j;
868 
869 	if (session->fd_pipe)
870 		return perf_header__read_pipe(session, fd);
871 
872 	if (perf_file_header__read(&f_header, self, fd) < 0) {
873 		pr_debug("incompatible file format\n");
874 		return -EINVAL;
875 	}
876 
877 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
878 	lseek(fd, f_header.attrs.offset, SEEK_SET);
879 
880 	for (i = 0; i < nr_attrs; i++) {
881 		struct perf_header_attr *attr;
882 		off_t tmp;
883 
884 		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
885 			goto out_errno;
886 
887 		tmp = lseek(fd, 0, SEEK_CUR);
888 
889 		attr = perf_header_attr__new(&f_attr.attr);
890 		if (attr == NULL)
891 			 return -ENOMEM;
892 
893 		nr_ids = f_attr.ids.size / sizeof(u64);
894 		lseek(fd, f_attr.ids.offset, SEEK_SET);
895 
896 		for (j = 0; j < nr_ids; j++) {
897 			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
898 				goto out_errno;
899 
900 			if (perf_header_attr__add_id(attr, f_id) < 0) {
901 				perf_header_attr__delete(attr);
902 				return -ENOMEM;
903 			}
904 		}
905 		if (perf_header__add_attr(self, attr) < 0) {
906 			perf_header_attr__delete(attr);
907 			return -ENOMEM;
908 		}
909 
910 		lseek(fd, tmp, SEEK_SET);
911 	}
912 
913 	if (f_header.event_types.size) {
914 		lseek(fd, f_header.event_types.offset, SEEK_SET);
915 		events = malloc(f_header.event_types.size);
916 		if (events == NULL)
917 			return -ENOMEM;
918 		if (perf_header__getbuffer64(self, fd, events,
919 					     f_header.event_types.size))
920 			goto out_errno;
921 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
922 	}
923 
924 	perf_header__process_sections(self, fd, perf_file_section__process);
925 
926 	lseek(fd, self->data_offset, SEEK_SET);
927 
928 	self->frozen = 1;
929 	return 0;
930 out_errno:
931 	return -errno;
932 }
933 
934 u64 perf_header__sample_type(struct perf_header *header)
935 {
936 	u64 type = 0;
937 	int i;
938 
939 	for (i = 0; i < header->attrs; i++) {
940 		struct perf_header_attr *attr = header->attr[i];
941 
942 		if (!type)
943 			type = attr->attr.sample_type;
944 		else if (type != attr->attr.sample_type)
945 			die("non matching sample_type");
946 	}
947 
948 	return type;
949 }
950 
951 bool perf_header__sample_id_all(const struct perf_header *header)
952 {
953 	bool value = false, first = true;
954 	int i;
955 
956 	for (i = 0; i < header->attrs; i++) {
957 		struct perf_header_attr *attr = header->attr[i];
958 
959 		if (first) {
960 			value = attr->attr.sample_id_all;
961 			first = false;
962 		} else if (value != attr->attr.sample_id_all)
963 			die("non matching sample_id_all");
964 	}
965 
966 	return value;
967 }
968 
969 struct perf_event_attr *
970 perf_header__find_attr(u64 id, struct perf_header *header)
971 {
972 	int i;
973 
974 	/*
975 	 * We set id to -1 if the data file doesn't contain sample
976 	 * ids. This can happen when the data file contains one type
977 	 * of event and in that case, the header can still store the
978 	 * event attribute information. Check for this and avoid
979 	 * walking through the entire list of ids which may be large.
980 	 */
981 	if (id == -1ULL) {
982 		if (header->attrs > 0)
983 			return &header->attr[0]->attr;
984 		return NULL;
985 	}
986 
987 	for (i = 0; i < header->attrs; i++) {
988 		struct perf_header_attr *attr = header->attr[i];
989 		int j;
990 
991 		for (j = 0; j < attr->ids; j++) {
992 			if (attr->id[j] == id)
993 				return &attr->attr;
994 		}
995 	}
996 
997 	return NULL;
998 }
999 
1000 int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
1001 			   event__handler_t process,
1002 			   struct perf_session *session)
1003 {
1004 	event_t *ev;
1005 	size_t size;
1006 	int err;
1007 
1008 	size = sizeof(struct perf_event_attr);
1009 	size = ALIGN(size, sizeof(u64));
1010 	size += sizeof(struct perf_event_header);
1011 	size += ids * sizeof(u64);
1012 
1013 	ev = malloc(size);
1014 
1015 	if (ev == NULL)
1016 		return -ENOMEM;
1017 
1018 	ev->attr.attr = *attr;
1019 	memcpy(ev->attr.id, id, ids * sizeof(u64));
1020 
1021 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
1022 	ev->attr.header.size = size;
1023 
1024 	err = process(ev, NULL, session);
1025 
1026 	free(ev);
1027 
1028 	return err;
1029 }
1030 
1031 int event__synthesize_attrs(struct perf_header *self, event__handler_t process,
1032 			    struct perf_session *session)
1033 {
1034 	struct perf_header_attr	*attr;
1035 	int i, err = 0;
1036 
1037 	for (i = 0; i < self->attrs; i++) {
1038 		attr = self->attr[i];
1039 
1040 		err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
1041 					     process, session);
1042 		if (err) {
1043 			pr_debug("failed to create perf header attribute\n");
1044 			return err;
1045 		}
1046 	}
1047 
1048 	return err;
1049 }
1050 
1051 int event__process_attr(event_t *self, struct perf_session *session)
1052 {
1053 	struct perf_header_attr *attr;
1054 	unsigned int i, ids, n_ids;
1055 
1056 	attr = perf_header_attr__new(&self->attr.attr);
1057 	if (attr == NULL)
1058 		return -ENOMEM;
1059 
1060 	ids = self->header.size;
1061 	ids -= (void *)&self->attr.id - (void *)self;
1062 	n_ids = ids / sizeof(u64);
1063 
1064 	for (i = 0; i < n_ids; i++) {
1065 		if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
1066 			perf_header_attr__delete(attr);
1067 			return -ENOMEM;
1068 		}
1069 	}
1070 
1071 	if (perf_header__add_attr(&session->header, attr) < 0) {
1072 		perf_header_attr__delete(attr);
1073 		return -ENOMEM;
1074 	}
1075 
1076 	perf_session__update_sample_type(session);
1077 
1078 	return 0;
1079 }
1080 
1081 int event__synthesize_event_type(u64 event_id, char *name,
1082 				 event__handler_t process,
1083 				 struct perf_session *session)
1084 {
1085 	event_t ev;
1086 	size_t size = 0;
1087 	int err = 0;
1088 
1089 	memset(&ev, 0, sizeof(ev));
1090 
1091 	ev.event_type.event_type.event_id = event_id;
1092 	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
1093 	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
1094 
1095 	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
1096 	size = strlen(name);
1097 	size = ALIGN(size, sizeof(u64));
1098 	ev.event_type.header.size = sizeof(ev.event_type) -
1099 		(sizeof(ev.event_type.event_type.name) - size);
1100 
1101 	err = process(&ev, NULL, session);
1102 
1103 	return err;
1104 }
1105 
1106 int event__synthesize_event_types(event__handler_t process,
1107 				  struct perf_session *session)
1108 {
1109 	struct perf_trace_event_type *type;
1110 	int i, err = 0;
1111 
1112 	for (i = 0; i < event_count; i++) {
1113 		type = &events[i];
1114 
1115 		err = event__synthesize_event_type(type->event_id, type->name,
1116 						   process, session);
1117 		if (err) {
1118 			pr_debug("failed to create perf header event type\n");
1119 			return err;
1120 		}
1121 	}
1122 
1123 	return err;
1124 }
1125 
1126 int event__process_event_type(event_t *self,
1127 			      struct perf_session *session __unused)
1128 {
1129 	if (perf_header__push_event(self->event_type.event_type.event_id,
1130 				    self->event_type.event_type.name) < 0)
1131 		return -ENOMEM;
1132 
1133 	return 0;
1134 }
1135 
1136 int event__synthesize_tracing_data(int fd, struct list_head *pattrs,
1137 				   event__handler_t process,
1138 				   struct perf_session *session __unused)
1139 {
1140 	event_t ev;
1141 	ssize_t size = 0, aligned_size = 0, padding;
1142 	int err = 0;
1143 
1144 	memset(&ev, 0, sizeof(ev));
1145 
1146 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
1147 	size = read_tracing_data_size(fd, pattrs);
1148 	if (size <= 0)
1149 		return size;
1150 	aligned_size = ALIGN(size, sizeof(u64));
1151 	padding = aligned_size - size;
1152 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
1153 	ev.tracing_data.size = aligned_size;
1154 
1155 	process(&ev, NULL, session);
1156 
1157 	err = read_tracing_data(fd, pattrs);
1158 	write_padded(fd, NULL, 0, padding);
1159 
1160 	return aligned_size;
1161 }
1162 
1163 int event__process_tracing_data(event_t *self,
1164 				struct perf_session *session)
1165 {
1166 	ssize_t size_read, padding, size = self->tracing_data.size;
1167 	off_t offset = lseek(session->fd, 0, SEEK_CUR);
1168 	char buf[BUFSIZ];
1169 
1170 	/* setup for reading amidst mmap */
1171 	lseek(session->fd, offset + sizeof(struct tracing_data_event),
1172 	      SEEK_SET);
1173 
1174 	size_read = trace_report(session->fd, session->repipe);
1175 
1176 	padding = ALIGN(size_read, sizeof(u64)) - size_read;
1177 
1178 	if (read(session->fd, buf, padding) < 0)
1179 		die("reading input file");
1180 	if (session->repipe) {
1181 		int retw = write(STDOUT_FILENO, buf, padding);
1182 		if (retw <= 0 || retw != padding)
1183 			die("repiping tracing data padding");
1184 	}
1185 
1186 	if (size_read + padding != size)
1187 		die("tracing data size mismatch");
1188 
1189 	return size_read + padding;
1190 }
1191 
1192 int event__synthesize_build_id(struct dso *pos, u16 misc,
1193 			       event__handler_t process,
1194 			       struct machine *machine,
1195 			       struct perf_session *session)
1196 {
1197 	event_t ev;
1198 	size_t len;
1199 	int err = 0;
1200 
1201 	if (!pos->hit)
1202 		return err;
1203 
1204 	memset(&ev, 0, sizeof(ev));
1205 
1206 	len = pos->long_name_len + 1;
1207 	len = ALIGN(len, NAME_ALIGN);
1208 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
1209 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
1210 	ev.build_id.header.misc = misc;
1211 	ev.build_id.pid = machine->pid;
1212 	ev.build_id.header.size = sizeof(ev.build_id) + len;
1213 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
1214 
1215 	err = process(&ev, NULL, session);
1216 
1217 	return err;
1218 }
1219 
1220 int event__process_build_id(event_t *self,
1221 			    struct perf_session *session)
1222 {
1223 	__event_process_build_id(&self->build_id,
1224 				 self->build_id.filename,
1225 				 session);
1226 	return 0;
1227 }
1228 
1229 void disable_buildid_cache(void)
1230 {
1231 	no_buildid_cache = true;
1232 }
1233