xref: /linux/tools/perf/util/header.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
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 /*
20  * Create new perf.data header attribute:
21  */
22 struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
23 {
24 	struct perf_header_attr *self = malloc(sizeof(*self));
25 
26 	if (self != NULL) {
27 		self->attr = *attr;
28 		self->ids  = 0;
29 		self->size = 1;
30 		self->id   = malloc(sizeof(u64));
31 		if (self->id == NULL) {
32 			free(self);
33 			self = NULL;
34 		}
35 	}
36 
37 	return self;
38 }
39 
40 void perf_header_attr__delete(struct perf_header_attr *self)
41 {
42 	free(self->id);
43 	free(self);
44 }
45 
46 int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
47 {
48 	int pos = self->ids;
49 
50 	self->ids++;
51 	if (self->ids > self->size) {
52 		int nsize = self->size * 2;
53 		u64 *nid = realloc(self->id, nsize * sizeof(u64));
54 
55 		if (nid == NULL)
56 			return -1;
57 
58 		self->size = nsize;
59 		self->id = nid;
60 	}
61 	self->id[pos] = id;
62 	return 0;
63 }
64 
65 int perf_header__init(struct perf_header *self)
66 {
67 	self->size = 1;
68 	self->attr = malloc(sizeof(void *));
69 	return self->attr == NULL ? -ENOMEM : 0;
70 }
71 
72 void perf_header__exit(struct perf_header *self)
73 {
74 	int i;
75 	for (i = 0; i < self->attrs; ++i)
76                 perf_header_attr__delete(self->attr[i]);
77 	free(self->attr);
78 }
79 
80 int perf_header__add_attr(struct perf_header *self,
81 			  struct perf_header_attr *attr)
82 {
83 	if (self->frozen)
84 		return -1;
85 
86 	if (self->attrs == self->size) {
87 		int nsize = self->size * 2;
88 		struct perf_header_attr **nattr;
89 
90 		nattr = realloc(self->attr, nsize * sizeof(void *));
91 		if (nattr == NULL)
92 			return -1;
93 
94 		self->size = nsize;
95 		self->attr = nattr;
96 	}
97 
98 	self->attr[self->attrs++] = attr;
99 	return 0;
100 }
101 
102 static int event_count;
103 static struct perf_trace_event_type *events;
104 
105 int perf_header__push_event(u64 id, const char *name)
106 {
107 	if (strlen(name) > MAX_EVENT_NAME)
108 		pr_warning("Event %s will be truncated\n", name);
109 
110 	if (!events) {
111 		events = malloc(sizeof(struct perf_trace_event_type));
112 		if (events == NULL)
113 			return -ENOMEM;
114 	} else {
115 		struct perf_trace_event_type *nevents;
116 
117 		nevents = realloc(events, (event_count + 1) * sizeof(*events));
118 		if (nevents == NULL)
119 			return -ENOMEM;
120 		events = nevents;
121 	}
122 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
123 	events[event_count].event_id = id;
124 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
125 	event_count++;
126 	return 0;
127 }
128 
129 char *perf_header__find_event(u64 id)
130 {
131 	int i;
132 	for (i = 0 ; i < event_count; i++) {
133 		if (events[i].event_id == id)
134 			return events[i].name;
135 	}
136 	return NULL;
137 }
138 
139 static const char *__perf_magic = "PERFFILE";
140 
141 #define PERF_MAGIC	(*(u64 *)__perf_magic)
142 
143 struct perf_file_attr {
144 	struct perf_event_attr	attr;
145 	struct perf_file_section	ids;
146 };
147 
148 void perf_header__set_feat(struct perf_header *self, int feat)
149 {
150 	set_bit(feat, self->adds_features);
151 }
152 
153 bool perf_header__has_feat(const struct perf_header *self, int feat)
154 {
155 	return test_bit(feat, self->adds_features);
156 }
157 
158 static int do_write(int fd, const void *buf, size_t size)
159 {
160 	while (size) {
161 		int ret = write(fd, buf, size);
162 
163 		if (ret < 0)
164 			return -errno;
165 
166 		size -= ret;
167 		buf += ret;
168 	}
169 
170 	return 0;
171 }
172 
173 #define NAME_ALIGN 64
174 
175 static int write_padded(int fd, const void *bf, size_t count,
176 			size_t count_aligned)
177 {
178 	static const char zero_buf[NAME_ALIGN];
179 	int err = do_write(fd, bf, count);
180 
181 	if (!err)
182 		err = do_write(fd, zero_buf, count_aligned - count);
183 
184 	return err;
185 }
186 
187 #define dsos__for_each_with_build_id(pos, head)	\
188 	list_for_each_entry(pos, head, node)	\
189 		if (!pos->has_build_id)		\
190 			continue;		\
191 		else
192 
193 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
194 				u16 misc, int fd)
195 {
196 	struct dso *pos;
197 
198 	dsos__for_each_with_build_id(pos, head) {
199 		int err;
200 		struct build_id_event b;
201 		size_t len;
202 
203 		if (!pos->hit)
204 			continue;
205 		len = pos->long_name_len + 1;
206 		len = ALIGN(len, NAME_ALIGN);
207 		memset(&b, 0, sizeof(b));
208 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
209 		b.pid = pid;
210 		b.header.misc = misc;
211 		b.header.size = sizeof(b) + len;
212 		err = do_write(fd, &b, sizeof(b));
213 		if (err < 0)
214 			return err;
215 		err = write_padded(fd, pos->long_name,
216 				   pos->long_name_len + 1, len);
217 		if (err < 0)
218 			return err;
219 	}
220 
221 	return 0;
222 }
223 
224 static int dsos__write_buildid_table(struct perf_header *header, int fd)
225 {
226 	struct perf_session *session = container_of(header,
227 			struct perf_session, header);
228 	struct rb_node *nd;
229 	int err = 0;
230 	u16 kmisc, umisc;
231 
232 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
233 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
234 		if (machine__is_host(pos)) {
235 			kmisc = PERF_RECORD_MISC_KERNEL;
236 			umisc = PERF_RECORD_MISC_USER;
237 		} else {
238 			kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
239 			umisc = PERF_RECORD_MISC_GUEST_USER;
240 		}
241 
242 		err = __dsos__write_buildid_table(&pos->kernel_dsos, pos->pid,
243 						  kmisc, fd);
244 		if (err == 0)
245 			err = __dsos__write_buildid_table(&pos->user_dsos,
246 							  pos->pid, umisc, fd);
247 		if (err)
248 			break;
249 	}
250 	return err;
251 }
252 
253 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
254 			  const char *name, bool is_kallsyms)
255 {
256 	const size_t size = PATH_MAX;
257 	char *filename = malloc(size),
258 	     *linkname = malloc(size), *targetname;
259 	int len, err = -1;
260 
261 	if (filename == NULL || linkname == NULL)
262 		goto out_free;
263 
264 	len = snprintf(filename, size, "%s%s%s",
265 		       debugdir, is_kallsyms ? "/" : "", name);
266 	if (mkdir_p(filename, 0755))
267 		goto out_free;
268 
269 	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
270 
271 	if (access(filename, F_OK)) {
272 		if (is_kallsyms) {
273 			 if (copyfile("/proc/kallsyms", filename))
274 				goto out_free;
275 		} else if (link(name, filename) && copyfile(name, filename))
276 			goto out_free;
277 	}
278 
279 	len = snprintf(linkname, size, "%s/.build-id/%.2s",
280 		       debugdir, sbuild_id);
281 
282 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
283 		goto out_free;
284 
285 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
286 	targetname = filename + strlen(debugdir) - 5;
287 	memcpy(targetname, "../..", 5);
288 
289 	if (symlink(targetname, linkname) == 0)
290 		err = 0;
291 out_free:
292 	free(filename);
293 	free(linkname);
294 	return err;
295 }
296 
297 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
298 				 const char *name, const char *debugdir,
299 				 bool is_kallsyms)
300 {
301 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
302 
303 	build_id__sprintf(build_id, build_id_size, sbuild_id);
304 
305 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
306 }
307 
308 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
309 {
310 	const size_t size = PATH_MAX;
311 	char *filename = malloc(size),
312 	     *linkname = malloc(size);
313 	int err = -1;
314 
315 	if (filename == NULL || linkname == NULL)
316 		goto out_free;
317 
318 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
319 		 debugdir, sbuild_id, sbuild_id + 2);
320 
321 	if (access(linkname, F_OK))
322 		goto out_free;
323 
324 	if (readlink(linkname, filename, size) < 0)
325 		goto out_free;
326 
327 	if (unlink(linkname))
328 		goto out_free;
329 
330 	/*
331 	 * Since the link is relative, we must make it absolute:
332 	 */
333 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
334 		 debugdir, sbuild_id, filename);
335 
336 	if (unlink(linkname))
337 		goto out_free;
338 
339 	err = 0;
340 out_free:
341 	free(filename);
342 	free(linkname);
343 	return err;
344 }
345 
346 static int dso__cache_build_id(struct dso *self, const char *debugdir)
347 {
348 	bool is_kallsyms = self->kernel && self->long_name[0] != '/';
349 
350 	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
351 				     self->long_name, debugdir, is_kallsyms);
352 }
353 
354 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
355 {
356 	struct dso *pos;
357 	int err = 0;
358 
359 	dsos__for_each_with_build_id(pos, head)
360 		if (dso__cache_build_id(pos, debugdir))
361 			err = -1;
362 
363 	return err;
364 }
365 
366 static int dsos__cache_build_ids(struct perf_header *self)
367 {
368 	struct perf_session *session = container_of(self,
369 			struct perf_session, header);
370 	struct rb_node *nd;
371 	int ret = 0;
372 	char debugdir[PATH_MAX];
373 
374 	snprintf(debugdir, sizeof(debugdir), "%s/%s", getenv("HOME"),
375 		 DEBUG_CACHE_DIR);
376 
377 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
378 		return -1;
379 
380 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
381 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
382 		ret |= __dsos__cache_build_ids(&pos->kernel_dsos, debugdir);
383 		ret |= __dsos__cache_build_ids(&pos->user_dsos, debugdir);
384 	}
385 	return ret ? -1 : 0;
386 }
387 
388 static bool dsos__read_build_ids(struct perf_header *self, bool with_hits)
389 {
390 	bool ret = false;
391 	struct perf_session *session = container_of(self,
392 			struct perf_session, header);
393 	struct rb_node *nd;
394 
395 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
396 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
397 		ret |= __dsos__read_build_ids(&pos->kernel_dsos, with_hits);
398 		ret |= __dsos__read_build_ids(&pos->user_dsos, with_hits);
399 	}
400 
401 	return ret;
402 }
403 
404 static int perf_header__adds_write(struct perf_header *self, int fd)
405 {
406 	int nr_sections;
407 	struct perf_file_section *feat_sec;
408 	int sec_size;
409 	u64 sec_start;
410 	int idx = 0, err;
411 
412 	if (dsos__read_build_ids(self, true))
413 		perf_header__set_feat(self, HEADER_BUILD_ID);
414 
415 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
416 	if (!nr_sections)
417 		return 0;
418 
419 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
420 	if (feat_sec == NULL)
421 		return -ENOMEM;
422 
423 	sec_size = sizeof(*feat_sec) * nr_sections;
424 
425 	sec_start = self->data_offset + self->data_size;
426 	lseek(fd, sec_start + sec_size, SEEK_SET);
427 
428 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
429 		struct perf_file_section *trace_sec;
430 
431 		trace_sec = &feat_sec[idx++];
432 
433 		/* Write trace info */
434 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
435 		read_tracing_data(fd, attrs, nr_counters);
436 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
437 	}
438 
439 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
440 		struct perf_file_section *buildid_sec;
441 
442 		buildid_sec = &feat_sec[idx++];
443 
444 		/* Write build-ids */
445 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
446 		err = dsos__write_buildid_table(self, fd);
447 		if (err < 0) {
448 			pr_debug("failed to write buildid table\n");
449 			goto out_free;
450 		}
451 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
452 					  buildid_sec->offset;
453 		dsos__cache_build_ids(self);
454 	}
455 
456 	lseek(fd, sec_start, SEEK_SET);
457 	err = do_write(fd, feat_sec, sec_size);
458 	if (err < 0)
459 		pr_debug("failed to write feature section\n");
460 out_free:
461 	free(feat_sec);
462 	return err;
463 }
464 
465 int perf_header__write_pipe(int fd)
466 {
467 	struct perf_pipe_file_header f_header;
468 	int err;
469 
470 	f_header = (struct perf_pipe_file_header){
471 		.magic	   = PERF_MAGIC,
472 		.size	   = sizeof(f_header),
473 	};
474 
475 	err = do_write(fd, &f_header, sizeof(f_header));
476 	if (err < 0) {
477 		pr_debug("failed to write perf pipe header\n");
478 		return err;
479 	}
480 
481 	return 0;
482 }
483 
484 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
485 {
486 	struct perf_file_header f_header;
487 	struct perf_file_attr   f_attr;
488 	struct perf_header_attr	*attr;
489 	int i, err;
490 
491 	lseek(fd, sizeof(f_header), SEEK_SET);
492 
493 
494 	for (i = 0; i < self->attrs; i++) {
495 		attr = self->attr[i];
496 
497 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
498 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
499 		if (err < 0) {
500 			pr_debug("failed to write perf header\n");
501 			return err;
502 		}
503 	}
504 
505 
506 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
507 
508 	for (i = 0; i < self->attrs; i++) {
509 		attr = self->attr[i];
510 
511 		f_attr = (struct perf_file_attr){
512 			.attr = attr->attr,
513 			.ids  = {
514 				.offset = attr->id_offset,
515 				.size   = attr->ids * sizeof(u64),
516 			}
517 		};
518 		err = do_write(fd, &f_attr, sizeof(f_attr));
519 		if (err < 0) {
520 			pr_debug("failed to write perf header attribute\n");
521 			return err;
522 		}
523 	}
524 
525 	self->event_offset = lseek(fd, 0, SEEK_CUR);
526 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
527 	if (events) {
528 		err = do_write(fd, events, self->event_size);
529 		if (err < 0) {
530 			pr_debug("failed to write perf header events\n");
531 			return err;
532 		}
533 	}
534 
535 	self->data_offset = lseek(fd, 0, SEEK_CUR);
536 
537 	if (at_exit) {
538 		err = perf_header__adds_write(self, fd);
539 		if (err < 0)
540 			return err;
541 	}
542 
543 	f_header = (struct perf_file_header){
544 		.magic	   = PERF_MAGIC,
545 		.size	   = sizeof(f_header),
546 		.attr_size = sizeof(f_attr),
547 		.attrs = {
548 			.offset = self->attr_offset,
549 			.size   = self->attrs * sizeof(f_attr),
550 		},
551 		.data = {
552 			.offset = self->data_offset,
553 			.size	= self->data_size,
554 		},
555 		.event_types = {
556 			.offset = self->event_offset,
557 			.size	= self->event_size,
558 		},
559 	};
560 
561 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
562 
563 	lseek(fd, 0, SEEK_SET);
564 	err = do_write(fd, &f_header, sizeof(f_header));
565 	if (err < 0) {
566 		pr_debug("failed to write perf header\n");
567 		return err;
568 	}
569 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
570 
571 	self->frozen = 1;
572 	return 0;
573 }
574 
575 static int perf_header__getbuffer64(struct perf_header *self,
576 				    int fd, void *buf, size_t size)
577 {
578 	if (do_read(fd, buf, size) <= 0)
579 		return -1;
580 
581 	if (self->needs_swap)
582 		mem_bswap_64(buf, size);
583 
584 	return 0;
585 }
586 
587 int perf_header__process_sections(struct perf_header *self, int fd,
588 				  int (*process)(struct perf_file_section *self,
589 						 struct perf_header *ph,
590 						 int feat, int fd))
591 {
592 	struct perf_file_section *feat_sec;
593 	int nr_sections;
594 	int sec_size;
595 	int idx = 0;
596 	int err = -1, feat = 1;
597 
598 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
599 	if (!nr_sections)
600 		return 0;
601 
602 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
603 	if (!feat_sec)
604 		return -1;
605 
606 	sec_size = sizeof(*feat_sec) * nr_sections;
607 
608 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
609 
610 	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
611 		goto out_free;
612 
613 	err = 0;
614 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
615 		if (perf_header__has_feat(self, feat)) {
616 			struct perf_file_section *sec = &feat_sec[idx++];
617 
618 			err = process(sec, self, feat, fd);
619 			if (err < 0)
620 				break;
621 		}
622 		++feat;
623 	}
624 out_free:
625 	free(feat_sec);
626 	return err;
627 }
628 
629 int perf_file_header__read(struct perf_file_header *self,
630 			   struct perf_header *ph, int fd)
631 {
632 	lseek(fd, 0, SEEK_SET);
633 
634 	if (do_read(fd, self, sizeof(*self)) <= 0 ||
635 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
636 		return -1;
637 
638 	if (self->attr_size != sizeof(struct perf_file_attr)) {
639 		u64 attr_size = bswap_64(self->attr_size);
640 
641 		if (attr_size != sizeof(struct perf_file_attr))
642 			return -1;
643 
644 		mem_bswap_64(self, offsetof(struct perf_file_header,
645 					    adds_features));
646 		ph->needs_swap = true;
647 	}
648 
649 	if (self->size != sizeof(*self)) {
650 		/* Support the previous format */
651 		if (self->size == offsetof(typeof(*self), adds_features))
652 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
653 		else
654 			return -1;
655 	}
656 
657 	memcpy(&ph->adds_features, &self->adds_features,
658 	       sizeof(ph->adds_features));
659 	/*
660 	 * FIXME: hack that assumes that if we need swap the perf.data file
661 	 * may be coming from an arch with a different word-size, ergo different
662 	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
663 	 * safe to assume that we have a build-id section. Trace files probably
664 	 * have several other issues in this realm anyway...
665 	 */
666 	if (ph->needs_swap) {
667 		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
668 		perf_header__set_feat(ph, HEADER_BUILD_ID);
669 	}
670 
671 	ph->event_offset = self->event_types.offset;
672 	ph->event_size   = self->event_types.size;
673 	ph->data_offset  = self->data.offset;
674 	ph->data_size	 = self->data.size;
675 	return 0;
676 }
677 
678 static int __event_process_build_id(struct build_id_event *bev,
679 				    char *filename,
680 				    struct perf_session *session)
681 {
682 	int err = -1;
683 	struct list_head *head;
684 	struct machine *machine;
685 	u16 misc;
686 	struct dso *dso;
687 	enum dso_kernel_type dso_type;
688 
689 	machine = perf_session__findnew_machine(session, bev->pid);
690 	if (!machine)
691 		goto out;
692 
693 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
694 
695 	switch (misc) {
696 	case PERF_RECORD_MISC_KERNEL:
697 		dso_type = DSO_TYPE_KERNEL;
698 		head = &machine->kernel_dsos;
699 		break;
700 	case PERF_RECORD_MISC_GUEST_KERNEL:
701 		dso_type = DSO_TYPE_GUEST_KERNEL;
702 		head = &machine->kernel_dsos;
703 		break;
704 	case PERF_RECORD_MISC_USER:
705 	case PERF_RECORD_MISC_GUEST_USER:
706 		dso_type = DSO_TYPE_USER;
707 		head = &machine->user_dsos;
708 		break;
709 	default:
710 		goto out;
711 	}
712 
713 	dso = __dsos__findnew(head, filename);
714 	if (dso != NULL) {
715 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
716 
717 		dso__set_build_id(dso, &bev->build_id);
718 
719 		if (filename[0] == '[')
720 			dso->kernel = dso_type;
721 
722 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
723 				  sbuild_id);
724 		pr_debug("build id event received for %s: %s\n",
725 			 dso->long_name, sbuild_id);
726 	}
727 
728 	err = 0;
729 out:
730 	return err;
731 }
732 
733 static int perf_header__read_build_ids(struct perf_header *self,
734 			int input, u64 offset, u64 size)
735 {
736 	struct perf_session *session = container_of(self,
737 			struct perf_session, header);
738 	struct build_id_event bev;
739 	char filename[PATH_MAX];
740 	u64 limit = offset + size;
741 	int err = -1;
742 
743 	while (offset < limit) {
744 		ssize_t len;
745 
746 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
747 			goto out;
748 
749 		if (self->needs_swap)
750 			perf_event_header__bswap(&bev.header);
751 
752 		len = bev.header.size - sizeof(bev);
753 		if (read(input, filename, len) != len)
754 			goto out;
755 
756 		__event_process_build_id(&bev, filename, session);
757 
758 		offset += bev.header.size;
759 	}
760 	err = 0;
761 out:
762 	return err;
763 }
764 
765 static int perf_file_section__process(struct perf_file_section *self,
766 				      struct perf_header *ph,
767 				      int feat, int fd)
768 {
769 	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
770 		pr_debug("Failed to lseek to %Ld offset for feature %d, "
771 			 "continuing...\n", self->offset, feat);
772 		return 0;
773 	}
774 
775 	switch (feat) {
776 	case HEADER_TRACE_INFO:
777 		trace_report(fd, false);
778 		break;
779 
780 	case HEADER_BUILD_ID:
781 		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
782 			pr_debug("Failed to read buildids, continuing...\n");
783 		break;
784 	default:
785 		pr_debug("unknown feature %d, continuing...\n", feat);
786 	}
787 
788 	return 0;
789 }
790 
791 static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
792 				       struct perf_header *ph, int fd,
793 				       bool repipe)
794 {
795 	if (do_read(fd, self, sizeof(*self)) <= 0 ||
796 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
797 		return -1;
798 
799 	if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
800 		return -1;
801 
802 	if (self->size != sizeof(*self)) {
803 		u64 size = bswap_64(self->size);
804 
805 		if (size != sizeof(*self))
806 			return -1;
807 
808 		ph->needs_swap = true;
809 	}
810 
811 	return 0;
812 }
813 
814 static int perf_header__read_pipe(struct perf_session *session, int fd)
815 {
816 	struct perf_header *self = &session->header;
817 	struct perf_pipe_file_header f_header;
818 
819 	if (perf_file_header__read_pipe(&f_header, self, fd,
820 					session->repipe) < 0) {
821 		pr_debug("incompatible file format\n");
822 		return -EINVAL;
823 	}
824 
825 	session->fd = fd;
826 
827 	return 0;
828 }
829 
830 int perf_header__read(struct perf_session *session, int fd)
831 {
832 	struct perf_header *self = &session->header;
833 	struct perf_file_header	f_header;
834 	struct perf_file_attr	f_attr;
835 	u64			f_id;
836 	int nr_attrs, nr_ids, i, j;
837 
838 	if (session->fd_pipe)
839 		return perf_header__read_pipe(session, fd);
840 
841 	if (perf_file_header__read(&f_header, self, fd) < 0) {
842 		pr_debug("incompatible file format\n");
843 		return -EINVAL;
844 	}
845 
846 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
847 	lseek(fd, f_header.attrs.offset, SEEK_SET);
848 
849 	for (i = 0; i < nr_attrs; i++) {
850 		struct perf_header_attr *attr;
851 		off_t tmp;
852 
853 		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
854 			goto out_errno;
855 
856 		tmp = lseek(fd, 0, SEEK_CUR);
857 
858 		attr = perf_header_attr__new(&f_attr.attr);
859 		if (attr == NULL)
860 			 return -ENOMEM;
861 
862 		nr_ids = f_attr.ids.size / sizeof(u64);
863 		lseek(fd, f_attr.ids.offset, SEEK_SET);
864 
865 		for (j = 0; j < nr_ids; j++) {
866 			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
867 				goto out_errno;
868 
869 			if (perf_header_attr__add_id(attr, f_id) < 0) {
870 				perf_header_attr__delete(attr);
871 				return -ENOMEM;
872 			}
873 		}
874 		if (perf_header__add_attr(self, attr) < 0) {
875 			perf_header_attr__delete(attr);
876 			return -ENOMEM;
877 		}
878 
879 		lseek(fd, tmp, SEEK_SET);
880 	}
881 
882 	if (f_header.event_types.size) {
883 		lseek(fd, f_header.event_types.offset, SEEK_SET);
884 		events = malloc(f_header.event_types.size);
885 		if (events == NULL)
886 			return -ENOMEM;
887 		if (perf_header__getbuffer64(self, fd, events,
888 					     f_header.event_types.size))
889 			goto out_errno;
890 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
891 	}
892 
893 	perf_header__process_sections(self, fd, perf_file_section__process);
894 
895 	lseek(fd, self->data_offset, SEEK_SET);
896 
897 	self->frozen = 1;
898 	return 0;
899 out_errno:
900 	return -errno;
901 }
902 
903 u64 perf_header__sample_type(struct perf_header *header)
904 {
905 	u64 type = 0;
906 	int i;
907 
908 	for (i = 0; i < header->attrs; i++) {
909 		struct perf_header_attr *attr = header->attr[i];
910 
911 		if (!type)
912 			type = attr->attr.sample_type;
913 		else if (type != attr->attr.sample_type)
914 			die("non matching sample_type");
915 	}
916 
917 	return type;
918 }
919 
920 struct perf_event_attr *
921 perf_header__find_attr(u64 id, struct perf_header *header)
922 {
923 	int i;
924 
925 	/*
926 	 * We set id to -1 if the data file doesn't contain sample
927 	 * ids. Check for this and avoid walking through the entire
928 	 * list of ids which may be large.
929 	 */
930 	if (id == -1ULL)
931 		return NULL;
932 
933 	for (i = 0; i < header->attrs; i++) {
934 		struct perf_header_attr *attr = header->attr[i];
935 		int j;
936 
937 		for (j = 0; j < attr->ids; j++) {
938 			if (attr->id[j] == id)
939 				return &attr->attr;
940 		}
941 	}
942 
943 	return NULL;
944 }
945 
946 int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
947 			   event__handler_t process,
948 			   struct perf_session *session)
949 {
950 	event_t *ev;
951 	size_t size;
952 	int err;
953 
954 	size = sizeof(struct perf_event_attr);
955 	size = ALIGN(size, sizeof(u64));
956 	size += sizeof(struct perf_event_header);
957 	size += ids * sizeof(u64);
958 
959 	ev = malloc(size);
960 
961 	ev->attr.attr = *attr;
962 	memcpy(ev->attr.id, id, ids * sizeof(u64));
963 
964 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
965 	ev->attr.header.size = size;
966 
967 	err = process(ev, session);
968 
969 	free(ev);
970 
971 	return err;
972 }
973 
974 int event__synthesize_attrs(struct perf_header *self,
975 			    event__handler_t process,
976 			    struct perf_session *session)
977 {
978 	struct perf_header_attr	*attr;
979 	int i, err = 0;
980 
981 	for (i = 0; i < self->attrs; i++) {
982 		attr = self->attr[i];
983 
984 		err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
985 					     process, session);
986 		if (err) {
987 			pr_debug("failed to create perf header attribute\n");
988 			return err;
989 		}
990 	}
991 
992 	return err;
993 }
994 
995 int event__process_attr(event_t *self, struct perf_session *session)
996 {
997 	struct perf_header_attr *attr;
998 	unsigned int i, ids, n_ids;
999 
1000 	attr = perf_header_attr__new(&self->attr.attr);
1001 	if (attr == NULL)
1002 		return -ENOMEM;
1003 
1004 	ids = self->header.size;
1005 	ids -= (void *)&self->attr.id - (void *)self;
1006 	n_ids = ids / sizeof(u64);
1007 
1008 	for (i = 0; i < n_ids; i++) {
1009 		if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
1010 			perf_header_attr__delete(attr);
1011 			return -ENOMEM;
1012 		}
1013 	}
1014 
1015 	if (perf_header__add_attr(&session->header, attr) < 0) {
1016 		perf_header_attr__delete(attr);
1017 		return -ENOMEM;
1018 	}
1019 
1020 	perf_session__update_sample_type(session);
1021 
1022 	return 0;
1023 }
1024 
1025 int event__synthesize_event_type(u64 event_id, char *name,
1026 				 event__handler_t process,
1027 				 struct perf_session *session)
1028 {
1029 	event_t ev;
1030 	size_t size = 0;
1031 	int err = 0;
1032 
1033 	memset(&ev, 0, sizeof(ev));
1034 
1035 	ev.event_type.event_type.event_id = event_id;
1036 	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
1037 	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
1038 
1039 	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
1040 	size = strlen(name);
1041 	size = ALIGN(size, sizeof(u64));
1042 	ev.event_type.header.size = sizeof(ev.event_type) -
1043 		(sizeof(ev.event_type.event_type.name) - size);
1044 
1045 	err = process(&ev, session);
1046 
1047 	return err;
1048 }
1049 
1050 int event__synthesize_event_types(event__handler_t process,
1051 				  struct perf_session *session)
1052 {
1053 	struct perf_trace_event_type *type;
1054 	int i, err = 0;
1055 
1056 	for (i = 0; i < event_count; i++) {
1057 		type = &events[i];
1058 
1059 		err = event__synthesize_event_type(type->event_id, type->name,
1060 						   process, session);
1061 		if (err) {
1062 			pr_debug("failed to create perf header event type\n");
1063 			return err;
1064 		}
1065 	}
1066 
1067 	return err;
1068 }
1069 
1070 int event__process_event_type(event_t *self,
1071 			      struct perf_session *session __unused)
1072 {
1073 	if (perf_header__push_event(self->event_type.event_type.event_id,
1074 				    self->event_type.event_type.name) < 0)
1075 		return -ENOMEM;
1076 
1077 	return 0;
1078 }
1079 
1080 int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
1081 				   int nb_events,
1082 				   event__handler_t process,
1083 				   struct perf_session *session __unused)
1084 {
1085 	event_t ev;
1086 	ssize_t size = 0, aligned_size = 0, padding;
1087 	int err = 0;
1088 
1089 	memset(&ev, 0, sizeof(ev));
1090 
1091 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
1092 	size = read_tracing_data_size(fd, pattrs, nb_events);
1093 	if (size <= 0)
1094 		return size;
1095 	aligned_size = ALIGN(size, sizeof(u64));
1096 	padding = aligned_size - size;
1097 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
1098 	ev.tracing_data.size = aligned_size;
1099 
1100 	process(&ev, session);
1101 
1102 	err = read_tracing_data(fd, pattrs, nb_events);
1103 	write_padded(fd, NULL, 0, padding);
1104 
1105 	return aligned_size;
1106 }
1107 
1108 int event__process_tracing_data(event_t *self,
1109 				struct perf_session *session)
1110 {
1111 	ssize_t size_read, padding, size = self->tracing_data.size;
1112 	off_t offset = lseek(session->fd, 0, SEEK_CUR);
1113 	char buf[BUFSIZ];
1114 
1115 	/* setup for reading amidst mmap */
1116 	lseek(session->fd, offset + sizeof(struct tracing_data_event),
1117 	      SEEK_SET);
1118 
1119 	size_read = trace_report(session->fd, session->repipe);
1120 
1121 	padding = ALIGN(size_read, sizeof(u64)) - size_read;
1122 
1123 	if (read(session->fd, buf, padding) < 0)
1124 		die("reading input file");
1125 	if (session->repipe) {
1126 		int retw = write(STDOUT_FILENO, buf, padding);
1127 		if (retw <= 0 || retw != padding)
1128 			die("repiping tracing data padding");
1129 	}
1130 
1131 	if (size_read + padding != size)
1132 		die("tracing data size mismatch");
1133 
1134 	return size_read + padding;
1135 }
1136 
1137 int event__synthesize_build_id(struct dso *pos, u16 misc,
1138 			       event__handler_t process,
1139 			       struct machine *machine,
1140 			       struct perf_session *session)
1141 {
1142 	event_t ev;
1143 	size_t len;
1144 	int err = 0;
1145 
1146 	if (!pos->hit)
1147 		return err;
1148 
1149 	memset(&ev, 0, sizeof(ev));
1150 
1151 	len = pos->long_name_len + 1;
1152 	len = ALIGN(len, NAME_ALIGN);
1153 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
1154 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
1155 	ev.build_id.header.misc = misc;
1156 	ev.build_id.pid = machine->pid;
1157 	ev.build_id.header.size = sizeof(ev.build_id) + len;
1158 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
1159 
1160 	err = process(&ev, session);
1161 
1162 	return err;
1163 }
1164 
1165 int event__process_build_id(event_t *self,
1166 			    struct perf_session *session)
1167 {
1168 	__event_process_build_id(&self->build_id,
1169 				 self->build_id.filename,
1170 				 session);
1171 	return 0;
1172 }
1173