xref: /openbmc/linux/tools/perf/util/header.c (revision 565d76cb)
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 "evlist.h"
12 #include "evsel.h"
13 #include "util.h"
14 #include "header.h"
15 #include "../perf.h"
16 #include "trace-event.h"
17 #include "session.h"
18 #include "symbol.h"
19 #include "debug.h"
20 
21 static bool no_buildid_cache = false;
22 
23 static int event_count;
24 static struct perf_trace_event_type *events;
25 
26 int perf_header__push_event(u64 id, const char *name)
27 {
28 	if (strlen(name) > MAX_EVENT_NAME)
29 		pr_warning("Event %s will be truncated\n", name);
30 
31 	if (!events) {
32 		events = malloc(sizeof(struct perf_trace_event_type));
33 		if (events == NULL)
34 			return -ENOMEM;
35 	} else {
36 		struct perf_trace_event_type *nevents;
37 
38 		nevents = realloc(events, (event_count + 1) * sizeof(*events));
39 		if (nevents == NULL)
40 			return -ENOMEM;
41 		events = nevents;
42 	}
43 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
44 	events[event_count].event_id = id;
45 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
46 	event_count++;
47 	return 0;
48 }
49 
50 char *perf_header__find_event(u64 id)
51 {
52 	int i;
53 	for (i = 0 ; i < event_count; i++) {
54 		if (events[i].event_id == id)
55 			return events[i].name;
56 	}
57 	return NULL;
58 }
59 
60 static const char *__perf_magic = "PERFFILE";
61 
62 #define PERF_MAGIC	(*(u64 *)__perf_magic)
63 
64 struct perf_file_attr {
65 	struct perf_event_attr	attr;
66 	struct perf_file_section	ids;
67 };
68 
69 void perf_header__set_feat(struct perf_header *header, int feat)
70 {
71 	set_bit(feat, header->adds_features);
72 }
73 
74 void perf_header__clear_feat(struct perf_header *header, int feat)
75 {
76 	clear_bit(feat, header->adds_features);
77 }
78 
79 bool perf_header__has_feat(const struct perf_header *header, int feat)
80 {
81 	return test_bit(feat, header->adds_features);
82 }
83 
84 static int do_write(int fd, const void *buf, size_t size)
85 {
86 	while (size) {
87 		int ret = write(fd, buf, size);
88 
89 		if (ret < 0)
90 			return -errno;
91 
92 		size -= ret;
93 		buf += ret;
94 	}
95 
96 	return 0;
97 }
98 
99 #define NAME_ALIGN 64
100 
101 static int write_padded(int fd, const void *bf, size_t count,
102 			size_t count_aligned)
103 {
104 	static const char zero_buf[NAME_ALIGN];
105 	int err = do_write(fd, bf, count);
106 
107 	if (!err)
108 		err = do_write(fd, zero_buf, count_aligned - count);
109 
110 	return err;
111 }
112 
113 #define dsos__for_each_with_build_id(pos, head)	\
114 	list_for_each_entry(pos, head, node)	\
115 		if (!pos->has_build_id)		\
116 			continue;		\
117 		else
118 
119 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
120 				u16 misc, int fd)
121 {
122 	struct dso *pos;
123 
124 	dsos__for_each_with_build_id(pos, head) {
125 		int err;
126 		struct build_id_event b;
127 		size_t len;
128 
129 		if (!pos->hit)
130 			continue;
131 		len = pos->long_name_len + 1;
132 		len = ALIGN(len, NAME_ALIGN);
133 		memset(&b, 0, sizeof(b));
134 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
135 		b.pid = pid;
136 		b.header.misc = misc;
137 		b.header.size = sizeof(b) + len;
138 		err = do_write(fd, &b, sizeof(b));
139 		if (err < 0)
140 			return err;
141 		err = write_padded(fd, pos->long_name,
142 				   pos->long_name_len + 1, len);
143 		if (err < 0)
144 			return err;
145 	}
146 
147 	return 0;
148 }
149 
150 static int machine__write_buildid_table(struct machine *machine, int fd)
151 {
152 	int err;
153 	u16 kmisc = PERF_RECORD_MISC_KERNEL,
154 	    umisc = PERF_RECORD_MISC_USER;
155 
156 	if (!machine__is_host(machine)) {
157 		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
158 		umisc = PERF_RECORD_MISC_GUEST_USER;
159 	}
160 
161 	err = __dsos__write_buildid_table(&machine->kernel_dsos, machine->pid,
162 					  kmisc, fd);
163 	if (err == 0)
164 		err = __dsos__write_buildid_table(&machine->user_dsos,
165 						  machine->pid, umisc, fd);
166 	return err;
167 }
168 
169 static int dsos__write_buildid_table(struct perf_header *header, int fd)
170 {
171 	struct perf_session *session = container_of(header,
172 			struct perf_session, header);
173 	struct rb_node *nd;
174 	int err = machine__write_buildid_table(&session->host_machine, fd);
175 
176 	if (err)
177 		return err;
178 
179 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
180 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
181 		err = machine__write_buildid_table(pos, fd);
182 		if (err)
183 			break;
184 	}
185 	return err;
186 }
187 
188 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
189 			  const char *name, bool is_kallsyms)
190 {
191 	const size_t size = PATH_MAX;
192 	char *realname, *filename = malloc(size),
193 	     *linkname = malloc(size), *targetname;
194 	int len, err = -1;
195 
196 	if (is_kallsyms)
197 		realname = (char *)name;
198 	else
199 		realname = realpath(name, NULL);
200 
201 	if (realname == NULL || filename == NULL || linkname == NULL)
202 		goto out_free;
203 
204 	len = snprintf(filename, size, "%s%s%s",
205 		       debugdir, is_kallsyms ? "/" : "", realname);
206 	if (mkdir_p(filename, 0755))
207 		goto out_free;
208 
209 	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
210 
211 	if (access(filename, F_OK)) {
212 		if (is_kallsyms) {
213 			 if (copyfile("/proc/kallsyms", filename))
214 				goto out_free;
215 		} else if (link(realname, filename) && copyfile(name, filename))
216 			goto out_free;
217 	}
218 
219 	len = snprintf(linkname, size, "%s/.build-id/%.2s",
220 		       debugdir, sbuild_id);
221 
222 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
223 		goto out_free;
224 
225 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
226 	targetname = filename + strlen(debugdir) - 5;
227 	memcpy(targetname, "../..", 5);
228 
229 	if (symlink(targetname, linkname) == 0)
230 		err = 0;
231 out_free:
232 	if (!is_kallsyms)
233 		free(realname);
234 	free(filename);
235 	free(linkname);
236 	return err;
237 }
238 
239 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
240 				 const char *name, const char *debugdir,
241 				 bool is_kallsyms)
242 {
243 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
244 
245 	build_id__sprintf(build_id, build_id_size, sbuild_id);
246 
247 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
248 }
249 
250 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
251 {
252 	const size_t size = PATH_MAX;
253 	char *filename = malloc(size),
254 	     *linkname = malloc(size);
255 	int err = -1;
256 
257 	if (filename == NULL || linkname == NULL)
258 		goto out_free;
259 
260 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
261 		 debugdir, sbuild_id, sbuild_id + 2);
262 
263 	if (access(linkname, F_OK))
264 		goto out_free;
265 
266 	if (readlink(linkname, filename, size) < 0)
267 		goto out_free;
268 
269 	if (unlink(linkname))
270 		goto out_free;
271 
272 	/*
273 	 * Since the link is relative, we must make it absolute:
274 	 */
275 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
276 		 debugdir, sbuild_id, filename);
277 
278 	if (unlink(linkname))
279 		goto out_free;
280 
281 	err = 0;
282 out_free:
283 	free(filename);
284 	free(linkname);
285 	return err;
286 }
287 
288 static int dso__cache_build_id(struct dso *dso, const char *debugdir)
289 {
290 	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
291 
292 	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id),
293 				     dso->long_name, debugdir, is_kallsyms);
294 }
295 
296 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
297 {
298 	struct dso *pos;
299 	int err = 0;
300 
301 	dsos__for_each_with_build_id(pos, head)
302 		if (dso__cache_build_id(pos, debugdir))
303 			err = -1;
304 
305 	return err;
306 }
307 
308 static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
309 {
310 	int ret = __dsos__cache_build_ids(&machine->kernel_dsos, debugdir);
311 	ret |= __dsos__cache_build_ids(&machine->user_dsos, debugdir);
312 	return ret;
313 }
314 
315 static int perf_session__cache_build_ids(struct perf_session *session)
316 {
317 	struct rb_node *nd;
318 	int ret;
319 	char debugdir[PATH_MAX];
320 
321 	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
322 
323 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
324 		return -1;
325 
326 	ret = machine__cache_build_ids(&session->host_machine, debugdir);
327 
328 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
329 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
330 		ret |= machine__cache_build_ids(pos, debugdir);
331 	}
332 	return ret ? -1 : 0;
333 }
334 
335 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
336 {
337 	bool ret = __dsos__read_build_ids(&machine->kernel_dsos, with_hits);
338 	ret |= __dsos__read_build_ids(&machine->user_dsos, with_hits);
339 	return ret;
340 }
341 
342 static bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
343 {
344 	struct rb_node *nd;
345 	bool ret = machine__read_build_ids(&session->host_machine, with_hits);
346 
347 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
348 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
349 		ret |= machine__read_build_ids(pos, with_hits);
350 	}
351 
352 	return ret;
353 }
354 
355 static int perf_header__adds_write(struct perf_header *header,
356 				   struct perf_evlist *evlist, int fd)
357 {
358 	int nr_sections;
359 	struct perf_session *session;
360 	struct perf_file_section *feat_sec;
361 	int sec_size;
362 	u64 sec_start;
363 	int idx = 0, err;
364 
365 	session = container_of(header, struct perf_session, header);
366 
367 	if (perf_header__has_feat(header, HEADER_BUILD_ID &&
368 	    !perf_session__read_build_ids(session, true)))
369 		perf_header__clear_feat(header, HEADER_BUILD_ID);
370 
371 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
372 	if (!nr_sections)
373 		return 0;
374 
375 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
376 	if (feat_sec == NULL)
377 		return -ENOMEM;
378 
379 	sec_size = sizeof(*feat_sec) * nr_sections;
380 
381 	sec_start = header->data_offset + header->data_size;
382 	lseek(fd, sec_start + sec_size, SEEK_SET);
383 
384 	if (perf_header__has_feat(header, HEADER_TRACE_INFO)) {
385 		struct perf_file_section *trace_sec;
386 
387 		trace_sec = &feat_sec[idx++];
388 
389 		/* Write trace info */
390 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
391 		read_tracing_data(fd, &evlist->entries);
392 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
393 	}
394 
395 	if (perf_header__has_feat(header, HEADER_BUILD_ID)) {
396 		struct perf_file_section *buildid_sec;
397 
398 		buildid_sec = &feat_sec[idx++];
399 
400 		/* Write build-ids */
401 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
402 		err = dsos__write_buildid_table(header, fd);
403 		if (err < 0) {
404 			pr_debug("failed to write buildid table\n");
405 			goto out_free;
406 		}
407 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
408 					  buildid_sec->offset;
409 		if (!no_buildid_cache)
410 			perf_session__cache_build_ids(session);
411 	}
412 
413 	lseek(fd, sec_start, SEEK_SET);
414 	err = do_write(fd, feat_sec, sec_size);
415 	if (err < 0)
416 		pr_debug("failed to write feature section\n");
417 out_free:
418 	free(feat_sec);
419 	return err;
420 }
421 
422 int perf_header__write_pipe(int fd)
423 {
424 	struct perf_pipe_file_header f_header;
425 	int err;
426 
427 	f_header = (struct perf_pipe_file_header){
428 		.magic	   = PERF_MAGIC,
429 		.size	   = sizeof(f_header),
430 	};
431 
432 	err = do_write(fd, &f_header, sizeof(f_header));
433 	if (err < 0) {
434 		pr_debug("failed to write perf pipe header\n");
435 		return err;
436 	}
437 
438 	return 0;
439 }
440 
441 int perf_session__write_header(struct perf_session *session,
442 			       struct perf_evlist *evlist,
443 			       int fd, bool at_exit)
444 {
445 	struct perf_file_header f_header;
446 	struct perf_file_attr   f_attr;
447 	struct perf_header *header = &session->header;
448 	struct perf_evsel *attr, *pair = NULL;
449 	int err;
450 
451 	lseek(fd, sizeof(f_header), SEEK_SET);
452 
453 	if (session->evlist != evlist)
454 		pair = list_entry(session->evlist->entries.next, struct perf_evsel, node);
455 
456 	list_for_each_entry(attr, &evlist->entries, node) {
457 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
458 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
459 		if (err < 0) {
460 out_err_write:
461 			pr_debug("failed to write perf header\n");
462 			return err;
463 		}
464 		if (session->evlist != evlist) {
465 			err = do_write(fd, pair->id, pair->ids * sizeof(u64));
466 			if (err < 0)
467 				goto out_err_write;
468 			attr->ids += pair->ids;
469 			pair = list_entry(pair->node.next, struct perf_evsel, node);
470 		}
471 	}
472 
473 	header->attr_offset = lseek(fd, 0, SEEK_CUR);
474 
475 	list_for_each_entry(attr, &evlist->entries, node) {
476 		f_attr = (struct perf_file_attr){
477 			.attr = attr->attr,
478 			.ids  = {
479 				.offset = attr->id_offset,
480 				.size   = attr->ids * sizeof(u64),
481 			}
482 		};
483 		err = do_write(fd, &f_attr, sizeof(f_attr));
484 		if (err < 0) {
485 			pr_debug("failed to write perf header attribute\n");
486 			return err;
487 		}
488 	}
489 
490 	header->event_offset = lseek(fd, 0, SEEK_CUR);
491 	header->event_size = event_count * sizeof(struct perf_trace_event_type);
492 	if (events) {
493 		err = do_write(fd, events, header->event_size);
494 		if (err < 0) {
495 			pr_debug("failed to write perf header events\n");
496 			return err;
497 		}
498 	}
499 
500 	header->data_offset = lseek(fd, 0, SEEK_CUR);
501 
502 	if (at_exit) {
503 		err = perf_header__adds_write(header, evlist, fd);
504 		if (err < 0)
505 			return err;
506 	}
507 
508 	f_header = (struct perf_file_header){
509 		.magic	   = PERF_MAGIC,
510 		.size	   = sizeof(f_header),
511 		.attr_size = sizeof(f_attr),
512 		.attrs = {
513 			.offset = header->attr_offset,
514 			.size   = evlist->nr_entries * sizeof(f_attr),
515 		},
516 		.data = {
517 			.offset = header->data_offset,
518 			.size	= header->data_size,
519 		},
520 		.event_types = {
521 			.offset = header->event_offset,
522 			.size	= header->event_size,
523 		},
524 	};
525 
526 	memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));
527 
528 	lseek(fd, 0, SEEK_SET);
529 	err = do_write(fd, &f_header, sizeof(f_header));
530 	if (err < 0) {
531 		pr_debug("failed to write perf header\n");
532 		return err;
533 	}
534 	lseek(fd, header->data_offset + header->data_size, SEEK_SET);
535 
536 	header->frozen = 1;
537 	return 0;
538 }
539 
540 static int perf_header__getbuffer64(struct perf_header *header,
541 				    int fd, void *buf, size_t size)
542 {
543 	if (readn(fd, buf, size) <= 0)
544 		return -1;
545 
546 	if (header->needs_swap)
547 		mem_bswap_64(buf, size);
548 
549 	return 0;
550 }
551 
552 int perf_header__process_sections(struct perf_header *header, int fd,
553 				  int (*process)(struct perf_file_section *section,
554 						 struct perf_header *ph,
555 						 int feat, int fd))
556 {
557 	struct perf_file_section *feat_sec;
558 	int nr_sections;
559 	int sec_size;
560 	int idx = 0;
561 	int err = -1, feat = 1;
562 
563 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
564 	if (!nr_sections)
565 		return 0;
566 
567 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
568 	if (!feat_sec)
569 		return -1;
570 
571 	sec_size = sizeof(*feat_sec) * nr_sections;
572 
573 	lseek(fd, header->data_offset + header->data_size, SEEK_SET);
574 
575 	if (perf_header__getbuffer64(header, fd, feat_sec, sec_size))
576 		goto out_free;
577 
578 	err = 0;
579 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
580 		if (perf_header__has_feat(header, feat)) {
581 			struct perf_file_section *sec = &feat_sec[idx++];
582 
583 			err = process(sec, header, feat, fd);
584 			if (err < 0)
585 				break;
586 		}
587 		++feat;
588 	}
589 out_free:
590 	free(feat_sec);
591 	return err;
592 }
593 
594 int perf_file_header__read(struct perf_file_header *header,
595 			   struct perf_header *ph, int fd)
596 {
597 	lseek(fd, 0, SEEK_SET);
598 
599 	if (readn(fd, header, sizeof(*header)) <= 0 ||
600 	    memcmp(&header->magic, __perf_magic, sizeof(header->magic)))
601 		return -1;
602 
603 	if (header->attr_size != sizeof(struct perf_file_attr)) {
604 		u64 attr_size = bswap_64(header->attr_size);
605 
606 		if (attr_size != sizeof(struct perf_file_attr))
607 			return -1;
608 
609 		mem_bswap_64(header, offsetof(struct perf_file_header,
610 					    adds_features));
611 		ph->needs_swap = true;
612 	}
613 
614 	if (header->size != sizeof(*header)) {
615 		/* Support the previous format */
616 		if (header->size == offsetof(typeof(*header), adds_features))
617 			bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
618 		else
619 			return -1;
620 	}
621 
622 	memcpy(&ph->adds_features, &header->adds_features,
623 	       sizeof(ph->adds_features));
624 	/*
625 	 * FIXME: hack that assumes that if we need swap the perf.data file
626 	 * may be coming from an arch with a different word-size, ergo different
627 	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
628 	 * safe to assume that we have a build-id section. Trace files probably
629 	 * have several other issues in this realm anyway...
630 	 */
631 	if (ph->needs_swap) {
632 		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
633 		perf_header__set_feat(ph, HEADER_BUILD_ID);
634 	}
635 
636 	ph->event_offset = header->event_types.offset;
637 	ph->event_size   = header->event_types.size;
638 	ph->data_offset  = header->data.offset;
639 	ph->data_size	 = header->data.size;
640 	return 0;
641 }
642 
643 static int __event_process_build_id(struct build_id_event *bev,
644 				    char *filename,
645 				    struct perf_session *session)
646 {
647 	int err = -1;
648 	struct list_head *head;
649 	struct machine *machine;
650 	u16 misc;
651 	struct dso *dso;
652 	enum dso_kernel_type dso_type;
653 
654 	machine = perf_session__findnew_machine(session, bev->pid);
655 	if (!machine)
656 		goto out;
657 
658 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
659 
660 	switch (misc) {
661 	case PERF_RECORD_MISC_KERNEL:
662 		dso_type = DSO_TYPE_KERNEL;
663 		head = &machine->kernel_dsos;
664 		break;
665 	case PERF_RECORD_MISC_GUEST_KERNEL:
666 		dso_type = DSO_TYPE_GUEST_KERNEL;
667 		head = &machine->kernel_dsos;
668 		break;
669 	case PERF_RECORD_MISC_USER:
670 	case PERF_RECORD_MISC_GUEST_USER:
671 		dso_type = DSO_TYPE_USER;
672 		head = &machine->user_dsos;
673 		break;
674 	default:
675 		goto out;
676 	}
677 
678 	dso = __dsos__findnew(head, filename);
679 	if (dso != NULL) {
680 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
681 
682 		dso__set_build_id(dso, &bev->build_id);
683 
684 		if (filename[0] == '[')
685 			dso->kernel = dso_type;
686 
687 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
688 				  sbuild_id);
689 		pr_debug("build id event received for %s: %s\n",
690 			 dso->long_name, sbuild_id);
691 	}
692 
693 	err = 0;
694 out:
695 	return err;
696 }
697 
698 static int perf_header__read_build_ids(struct perf_header *header,
699 				       int input, u64 offset, u64 size)
700 {
701 	struct perf_session *session = container_of(header, struct perf_session, header);
702 	struct build_id_event bev;
703 	char filename[PATH_MAX];
704 	u64 limit = offset + size;
705 	int err = -1;
706 
707 	while (offset < limit) {
708 		ssize_t len;
709 
710 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
711 			goto out;
712 
713 		if (header->needs_swap)
714 			perf_event_header__bswap(&bev.header);
715 
716 		len = bev.header.size - sizeof(bev);
717 		if (read(input, filename, len) != len)
718 			goto out;
719 
720 		__event_process_build_id(&bev, filename, session);
721 
722 		offset += bev.header.size;
723 	}
724 	err = 0;
725 out:
726 	return err;
727 }
728 
729 static int perf_file_section__process(struct perf_file_section *section,
730 				      struct perf_header *ph,
731 				      int feat, int fd)
732 {
733 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
734 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
735 			  "%d, continuing...\n", section->offset, feat);
736 		return 0;
737 	}
738 
739 	switch (feat) {
740 	case HEADER_TRACE_INFO:
741 		trace_report(fd, false);
742 		break;
743 
744 	case HEADER_BUILD_ID:
745 		if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
746 			pr_debug("Failed to read buildids, continuing...\n");
747 		break;
748 	default:
749 		pr_debug("unknown feature %d, continuing...\n", feat);
750 	}
751 
752 	return 0;
753 }
754 
755 static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
756 				       struct perf_header *ph, int fd,
757 				       bool repipe)
758 {
759 	if (readn(fd, header, sizeof(*header)) <= 0 ||
760 	    memcmp(&header->magic, __perf_magic, sizeof(header->magic)))
761 		return -1;
762 
763 	if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0)
764 		return -1;
765 
766 	if (header->size != sizeof(*header)) {
767 		u64 size = bswap_64(header->size);
768 
769 		if (size != sizeof(*header))
770 			return -1;
771 
772 		ph->needs_swap = true;
773 	}
774 
775 	return 0;
776 }
777 
778 static int perf_header__read_pipe(struct perf_session *session, int fd)
779 {
780 	struct perf_header *header = &session->header;
781 	struct perf_pipe_file_header f_header;
782 
783 	if (perf_file_header__read_pipe(&f_header, header, fd,
784 					session->repipe) < 0) {
785 		pr_debug("incompatible file format\n");
786 		return -EINVAL;
787 	}
788 
789 	session->fd = fd;
790 
791 	return 0;
792 }
793 
794 int perf_session__read_header(struct perf_session *session, int fd)
795 {
796 	struct perf_header *header = &session->header;
797 	struct perf_file_header	f_header;
798 	struct perf_file_attr	f_attr;
799 	u64			f_id;
800 	int nr_attrs, nr_ids, i, j;
801 
802 	session->evlist = perf_evlist__new(NULL, NULL);
803 	if (session->evlist == NULL)
804 		return -ENOMEM;
805 
806 	if (session->fd_pipe)
807 		return perf_header__read_pipe(session, fd);
808 
809 	if (perf_file_header__read(&f_header, header, fd) < 0) {
810 		pr_debug("incompatible file format\n");
811 		return -EINVAL;
812 	}
813 
814 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
815 	lseek(fd, f_header.attrs.offset, SEEK_SET);
816 
817 	for (i = 0; i < nr_attrs; i++) {
818 		struct perf_evsel *evsel;
819 		off_t tmp;
820 
821 		if (perf_header__getbuffer64(header, fd, &f_attr, sizeof(f_attr)))
822 			goto out_errno;
823 
824 		tmp = lseek(fd, 0, SEEK_CUR);
825 		evsel = perf_evsel__new(&f_attr.attr, i);
826 
827 		if (evsel == NULL)
828 			goto out_delete_evlist;
829 		/*
830 		 * Do it before so that if perf_evsel__alloc_id fails, this
831 		 * entry gets purged too at perf_evlist__delete().
832 		 */
833 		perf_evlist__add(session->evlist, evsel);
834 
835 		nr_ids = f_attr.ids.size / sizeof(u64);
836 		/*
837 		 * We don't have the cpu and thread maps on the header, so
838 		 * for allocating the perf_sample_id table we fake 1 cpu and
839 		 * hattr->ids threads.
840 		 */
841 		if (perf_evsel__alloc_id(evsel, 1, nr_ids))
842 			goto out_delete_evlist;
843 
844 		lseek(fd, f_attr.ids.offset, SEEK_SET);
845 
846 		for (j = 0; j < nr_ids; j++) {
847 			if (perf_header__getbuffer64(header, fd, &f_id, sizeof(f_id)))
848 				goto out_errno;
849 
850 			perf_evlist__id_add(session->evlist, evsel, 0, j, f_id);
851 		}
852 
853 		lseek(fd, tmp, SEEK_SET);
854 	}
855 
856 	if (f_header.event_types.size) {
857 		lseek(fd, f_header.event_types.offset, SEEK_SET);
858 		events = malloc(f_header.event_types.size);
859 		if (events == NULL)
860 			return -ENOMEM;
861 		if (perf_header__getbuffer64(header, fd, events,
862 					     f_header.event_types.size))
863 			goto out_errno;
864 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
865 	}
866 
867 	perf_header__process_sections(header, fd, perf_file_section__process);
868 
869 	lseek(fd, header->data_offset, SEEK_SET);
870 
871 	header->frozen = 1;
872 	return 0;
873 out_errno:
874 	return -errno;
875 
876 out_delete_evlist:
877 	perf_evlist__delete(session->evlist);
878 	session->evlist = NULL;
879 	return -ENOMEM;
880 }
881 
882 u64 perf_evlist__sample_type(struct perf_evlist *evlist)
883 {
884 	struct perf_evsel *pos;
885 	u64 type = 0;
886 
887 	list_for_each_entry(pos, &evlist->entries, node) {
888 		if (!type)
889 			type = pos->attr.sample_type;
890 		else if (type != pos->attr.sample_type)
891 			die("non matching sample_type");
892 	}
893 
894 	return type;
895 }
896 
897 bool perf_evlist__sample_id_all(const struct perf_evlist *evlist)
898 {
899 	bool value = false, first = true;
900 	struct perf_evsel *pos;
901 
902 	list_for_each_entry(pos, &evlist->entries, node) {
903 		if (first) {
904 			value = pos->attr.sample_id_all;
905 			first = false;
906 		} else if (value != pos->attr.sample_id_all)
907 			die("non matching sample_id_all");
908 	}
909 
910 	return value;
911 }
912 
913 int perf_event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
914 				perf_event__handler_t process,
915 				struct perf_session *session)
916 {
917 	union perf_event *ev;
918 	size_t size;
919 	int err;
920 
921 	size = sizeof(struct perf_event_attr);
922 	size = ALIGN(size, sizeof(u64));
923 	size += sizeof(struct perf_event_header);
924 	size += ids * sizeof(u64);
925 
926 	ev = malloc(size);
927 
928 	if (ev == NULL)
929 		return -ENOMEM;
930 
931 	ev->attr.attr = *attr;
932 	memcpy(ev->attr.id, id, ids * sizeof(u64));
933 
934 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
935 	ev->attr.header.size = size;
936 
937 	err = process(ev, NULL, session);
938 
939 	free(ev);
940 
941 	return err;
942 }
943 
944 int perf_session__synthesize_attrs(struct perf_session *session,
945 				   perf_event__handler_t process)
946 {
947 	struct perf_evsel *attr;
948 	int err = 0;
949 
950 	list_for_each_entry(attr, &session->evlist->entries, node) {
951 		err = perf_event__synthesize_attr(&attr->attr, attr->ids,
952 						  attr->id, process, session);
953 		if (err) {
954 			pr_debug("failed to create perf header attribute\n");
955 			return err;
956 		}
957 	}
958 
959 	return err;
960 }
961 
962 int perf_event__process_attr(union perf_event *event,
963 			     struct perf_session *session)
964 {
965 	unsigned int i, ids, n_ids;
966 	struct perf_evsel *evsel;
967 
968 	if (session->evlist == NULL) {
969 		session->evlist = perf_evlist__new(NULL, NULL);
970 		if (session->evlist == NULL)
971 			return -ENOMEM;
972 	}
973 
974 	evsel = perf_evsel__new(&event->attr.attr,
975 				session->evlist->nr_entries);
976 	if (evsel == NULL)
977 		return -ENOMEM;
978 
979 	perf_evlist__add(session->evlist, evsel);
980 
981 	ids = event->header.size;
982 	ids -= (void *)&event->attr.id - (void *)event;
983 	n_ids = ids / sizeof(u64);
984 	/*
985 	 * We don't have the cpu and thread maps on the header, so
986 	 * for allocating the perf_sample_id table we fake 1 cpu and
987 	 * hattr->ids threads.
988 	 */
989 	if (perf_evsel__alloc_id(evsel, 1, n_ids))
990 		return -ENOMEM;
991 
992 	for (i = 0; i < n_ids; i++) {
993 		perf_evlist__id_add(session->evlist, evsel, 0, i,
994 				    event->attr.id[i]);
995 	}
996 
997 	perf_session__update_sample_type(session);
998 
999 	return 0;
1000 }
1001 
1002 int perf_event__synthesize_event_type(u64 event_id, char *name,
1003 				      perf_event__handler_t process,
1004 				      struct perf_session *session)
1005 {
1006 	union perf_event ev;
1007 	size_t size = 0;
1008 	int err = 0;
1009 
1010 	memset(&ev, 0, sizeof(ev));
1011 
1012 	ev.event_type.event_type.event_id = event_id;
1013 	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
1014 	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
1015 
1016 	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
1017 	size = strlen(name);
1018 	size = ALIGN(size, sizeof(u64));
1019 	ev.event_type.header.size = sizeof(ev.event_type) -
1020 		(sizeof(ev.event_type.event_type.name) - size);
1021 
1022 	err = process(&ev, NULL, session);
1023 
1024 	return err;
1025 }
1026 
1027 int perf_event__synthesize_event_types(perf_event__handler_t process,
1028 				       struct perf_session *session)
1029 {
1030 	struct perf_trace_event_type *type;
1031 	int i, err = 0;
1032 
1033 	for (i = 0; i < event_count; i++) {
1034 		type = &events[i];
1035 
1036 		err = perf_event__synthesize_event_type(type->event_id,
1037 							type->name, process,
1038 							session);
1039 		if (err) {
1040 			pr_debug("failed to create perf header event type\n");
1041 			return err;
1042 		}
1043 	}
1044 
1045 	return err;
1046 }
1047 
1048 int perf_event__process_event_type(union perf_event *event,
1049 				   struct perf_session *session __unused)
1050 {
1051 	if (perf_header__push_event(event->event_type.event_type.event_id,
1052 				    event->event_type.event_type.name) < 0)
1053 		return -ENOMEM;
1054 
1055 	return 0;
1056 }
1057 
1058 int perf_event__synthesize_tracing_data(int fd, struct perf_evlist *evlist,
1059 					 perf_event__handler_t process,
1060 				   struct perf_session *session __unused)
1061 {
1062 	union perf_event ev;
1063 	ssize_t size = 0, aligned_size = 0, padding;
1064 	int err __used = 0;
1065 
1066 	memset(&ev, 0, sizeof(ev));
1067 
1068 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
1069 	size = read_tracing_data_size(fd, &evlist->entries);
1070 	if (size <= 0)
1071 		return size;
1072 	aligned_size = ALIGN(size, sizeof(u64));
1073 	padding = aligned_size - size;
1074 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
1075 	ev.tracing_data.size = aligned_size;
1076 
1077 	process(&ev, NULL, session);
1078 
1079 	err = read_tracing_data(fd, &evlist->entries);
1080 	write_padded(fd, NULL, 0, padding);
1081 
1082 	return aligned_size;
1083 }
1084 
1085 int perf_event__process_tracing_data(union perf_event *event,
1086 				     struct perf_session *session)
1087 {
1088 	ssize_t size_read, padding, size = event->tracing_data.size;
1089 	off_t offset = lseek(session->fd, 0, SEEK_CUR);
1090 	char buf[BUFSIZ];
1091 
1092 	/* setup for reading amidst mmap */
1093 	lseek(session->fd, offset + sizeof(struct tracing_data_event),
1094 	      SEEK_SET);
1095 
1096 	size_read = trace_report(session->fd, session->repipe);
1097 
1098 	padding = ALIGN(size_read, sizeof(u64)) - size_read;
1099 
1100 	if (read(session->fd, buf, padding) < 0)
1101 		die("reading input file");
1102 	if (session->repipe) {
1103 		int retw = write(STDOUT_FILENO, buf, padding);
1104 		if (retw <= 0 || retw != padding)
1105 			die("repiping tracing data padding");
1106 	}
1107 
1108 	if (size_read + padding != size)
1109 		die("tracing data size mismatch");
1110 
1111 	return size_read + padding;
1112 }
1113 
1114 int perf_event__synthesize_build_id(struct dso *pos, u16 misc,
1115 				    perf_event__handler_t process,
1116 				    struct machine *machine,
1117 				    struct perf_session *session)
1118 {
1119 	union perf_event ev;
1120 	size_t len;
1121 	int err = 0;
1122 
1123 	if (!pos->hit)
1124 		return err;
1125 
1126 	memset(&ev, 0, sizeof(ev));
1127 
1128 	len = pos->long_name_len + 1;
1129 	len = ALIGN(len, NAME_ALIGN);
1130 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
1131 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
1132 	ev.build_id.header.misc = misc;
1133 	ev.build_id.pid = machine->pid;
1134 	ev.build_id.header.size = sizeof(ev.build_id) + len;
1135 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
1136 
1137 	err = process(&ev, NULL, session);
1138 
1139 	return err;
1140 }
1141 
1142 int perf_event__process_build_id(union perf_event *event,
1143 				 struct perf_session *session)
1144 {
1145 	__event_process_build_id(&event->build_id,
1146 				 event->build_id.filename,
1147 				 session);
1148 	return 0;
1149 }
1150 
1151 void disable_buildid_cache(void)
1152 {
1153 	no_buildid_cache = true;
1154 }
1155