xref: /linux/tools/perf/util/header.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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 #define MAX_EVENT_NAME 64
103 
104 struct perf_trace_event_type {
105 	u64	event_id;
106 	char	name[MAX_EVENT_NAME];
107 };
108 
109 static int event_count;
110 static struct perf_trace_event_type *events;
111 
112 int perf_header__push_event(u64 id, const char *name)
113 {
114 	if (strlen(name) > MAX_EVENT_NAME)
115 		pr_warning("Event %s will be truncated\n", name);
116 
117 	if (!events) {
118 		events = malloc(sizeof(struct perf_trace_event_type));
119 		if (events == NULL)
120 			return -ENOMEM;
121 	} else {
122 		struct perf_trace_event_type *nevents;
123 
124 		nevents = realloc(events, (event_count + 1) * sizeof(*events));
125 		if (nevents == NULL)
126 			return -ENOMEM;
127 		events = nevents;
128 	}
129 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
130 	events[event_count].event_id = id;
131 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
132 	event_count++;
133 	return 0;
134 }
135 
136 char *perf_header__find_event(u64 id)
137 {
138 	int i;
139 	for (i = 0 ; i < event_count; i++) {
140 		if (events[i].event_id == id)
141 			return events[i].name;
142 	}
143 	return NULL;
144 }
145 
146 static const char *__perf_magic = "PERFFILE";
147 
148 #define PERF_MAGIC	(*(u64 *)__perf_magic)
149 
150 struct perf_file_attr {
151 	struct perf_event_attr	attr;
152 	struct perf_file_section	ids;
153 };
154 
155 void perf_header__set_feat(struct perf_header *self, int feat)
156 {
157 	set_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, u16 misc, int fd)
201 {
202 	struct dso *pos;
203 
204 	dsos__for_each_with_build_id(pos, head) {
205 		int err;
206 		struct build_id_event b;
207 		size_t len;
208 
209 		if (!pos->hit)
210 			continue;
211 		len = pos->long_name_len + 1;
212 		len = ALIGN(len, NAME_ALIGN);
213 		memset(&b, 0, sizeof(b));
214 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
215 		b.header.misc = misc;
216 		b.header.size = sizeof(b) + len;
217 		err = do_write(fd, &b, sizeof(b));
218 		if (err < 0)
219 			return err;
220 		err = write_padded(fd, pos->long_name,
221 				   pos->long_name_len + 1, len);
222 		if (err < 0)
223 			return err;
224 	}
225 
226 	return 0;
227 }
228 
229 static int dsos__write_buildid_table(int fd)
230 {
231 	int err = __dsos__write_buildid_table(&dsos__kernel,
232 					      PERF_RECORD_MISC_KERNEL, fd);
233 	if (err == 0)
234 		err = __dsos__write_buildid_table(&dsos__user,
235 						  PERF_RECORD_MISC_USER, fd);
236 	return err;
237 }
238 
239 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
240 			  const char *name, bool is_kallsyms)
241 {
242 	const size_t size = PATH_MAX;
243 	char *filename = malloc(size),
244 	     *linkname = malloc(size), *targetname;
245 	int len, err = -1;
246 
247 	if (filename == NULL || linkname == NULL)
248 		goto out_free;
249 
250 	len = snprintf(filename, size, "%s%s%s",
251 		       debugdir, is_kallsyms ? "/" : "", name);
252 	if (mkdir_p(filename, 0755))
253 		goto out_free;
254 
255 	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
256 
257 	if (access(filename, F_OK)) {
258 		if (is_kallsyms) {
259 			 if (copyfile("/proc/kallsyms", filename))
260 				goto out_free;
261 		} else if (link(name, filename) && copyfile(name, filename))
262 			goto out_free;
263 	}
264 
265 	len = snprintf(linkname, size, "%s/.build-id/%.2s",
266 		       debugdir, sbuild_id);
267 
268 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
269 		goto out_free;
270 
271 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
272 	targetname = filename + strlen(debugdir) - 5;
273 	memcpy(targetname, "../..", 5);
274 
275 	if (symlink(targetname, linkname) == 0)
276 		err = 0;
277 out_free:
278 	free(filename);
279 	free(linkname);
280 	return err;
281 }
282 
283 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
284 				 const char *name, const char *debugdir,
285 				 bool is_kallsyms)
286 {
287 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
288 
289 	build_id__sprintf(build_id, build_id_size, sbuild_id);
290 
291 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
292 }
293 
294 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
295 {
296 	const size_t size = PATH_MAX;
297 	char *filename = malloc(size),
298 	     *linkname = malloc(size);
299 	int err = -1;
300 
301 	if (filename == NULL || linkname == NULL)
302 		goto out_free;
303 
304 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
305 		 debugdir, sbuild_id, sbuild_id + 2);
306 
307 	if (access(linkname, F_OK))
308 		goto out_free;
309 
310 	if (readlink(linkname, filename, size) < 0)
311 		goto out_free;
312 
313 	if (unlink(linkname))
314 		goto out_free;
315 
316 	/*
317 	 * Since the link is relative, we must make it absolute:
318 	 */
319 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
320 		 debugdir, sbuild_id, filename);
321 
322 	if (unlink(linkname))
323 		goto out_free;
324 
325 	err = 0;
326 out_free:
327 	free(filename);
328 	free(linkname);
329 	return err;
330 }
331 
332 static int dso__cache_build_id(struct dso *self, const char *debugdir)
333 {
334 	bool is_kallsyms = self->kernel && self->long_name[0] != '/';
335 
336 	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
337 				     self->long_name, debugdir, is_kallsyms);
338 }
339 
340 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
341 {
342 	struct dso *pos;
343 	int err = 0;
344 
345 	dsos__for_each_with_build_id(pos, head)
346 		if (dso__cache_build_id(pos, debugdir))
347 			err = -1;
348 
349 	return err;
350 }
351 
352 static int dsos__cache_build_ids(void)
353 {
354 	int err_kernel, err_user;
355 	char debugdir[PATH_MAX];
356 
357 	snprintf(debugdir, sizeof(debugdir), "%s/%s", getenv("HOME"),
358 		 DEBUG_CACHE_DIR);
359 
360 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
361 		return -1;
362 
363 	err_kernel = __dsos__cache_build_ids(&dsos__kernel, debugdir);
364 	err_user   = __dsos__cache_build_ids(&dsos__user, debugdir);
365 	return err_kernel || err_user ? -1 : 0;
366 }
367 
368 static int perf_header__adds_write(struct perf_header *self, int fd)
369 {
370 	int nr_sections;
371 	struct perf_file_section *feat_sec;
372 	int sec_size;
373 	u64 sec_start;
374 	int idx = 0, err;
375 
376 	if (dsos__read_build_ids(true))
377 		perf_header__set_feat(self, HEADER_BUILD_ID);
378 
379 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
380 	if (!nr_sections)
381 		return 0;
382 
383 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
384 	if (feat_sec == NULL)
385 		return -ENOMEM;
386 
387 	sec_size = sizeof(*feat_sec) * nr_sections;
388 
389 	sec_start = self->data_offset + self->data_size;
390 	lseek(fd, sec_start + sec_size, SEEK_SET);
391 
392 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
393 		struct perf_file_section *trace_sec;
394 
395 		trace_sec = &feat_sec[idx++];
396 
397 		/* Write trace info */
398 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
399 		read_tracing_data(fd, attrs, nr_counters);
400 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
401 	}
402 
403 
404 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
405 		struct perf_file_section *buildid_sec;
406 
407 		buildid_sec = &feat_sec[idx++];
408 
409 		/* Write build-ids */
410 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
411 		err = dsos__write_buildid_table(fd);
412 		if (err < 0) {
413 			pr_debug("failed to write buildid table\n");
414 			goto out_free;
415 		}
416 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
417 					  buildid_sec->offset;
418 		dsos__cache_build_ids();
419 	}
420 
421 	lseek(fd, sec_start, SEEK_SET);
422 	err = do_write(fd, feat_sec, sec_size);
423 	if (err < 0)
424 		pr_debug("failed to write feature section\n");
425 out_free:
426 	free(feat_sec);
427 	return err;
428 }
429 
430 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
431 {
432 	struct perf_file_header f_header;
433 	struct perf_file_attr   f_attr;
434 	struct perf_header_attr	*attr;
435 	int i, err;
436 
437 	lseek(fd, sizeof(f_header), SEEK_SET);
438 
439 
440 	for (i = 0; i < self->attrs; i++) {
441 		attr = self->attr[i];
442 
443 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
444 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
445 		if (err < 0) {
446 			pr_debug("failed to write perf header\n");
447 			return err;
448 		}
449 	}
450 
451 
452 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
453 
454 	for (i = 0; i < self->attrs; i++) {
455 		attr = self->attr[i];
456 
457 		f_attr = (struct perf_file_attr){
458 			.attr = attr->attr,
459 			.ids  = {
460 				.offset = attr->id_offset,
461 				.size   = attr->ids * sizeof(u64),
462 			}
463 		};
464 		err = do_write(fd, &f_attr, sizeof(f_attr));
465 		if (err < 0) {
466 			pr_debug("failed to write perf header attribute\n");
467 			return err;
468 		}
469 	}
470 
471 	self->event_offset = lseek(fd, 0, SEEK_CUR);
472 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
473 	if (events) {
474 		err = do_write(fd, events, self->event_size);
475 		if (err < 0) {
476 			pr_debug("failed to write perf header events\n");
477 			return err;
478 		}
479 	}
480 
481 	self->data_offset = lseek(fd, 0, SEEK_CUR);
482 
483 	if (at_exit) {
484 		err = perf_header__adds_write(self, fd);
485 		if (err < 0)
486 			return err;
487 	}
488 
489 	f_header = (struct perf_file_header){
490 		.magic	   = PERF_MAGIC,
491 		.size	   = sizeof(f_header),
492 		.attr_size = sizeof(f_attr),
493 		.attrs = {
494 			.offset = self->attr_offset,
495 			.size   = self->attrs * sizeof(f_attr),
496 		},
497 		.data = {
498 			.offset = self->data_offset,
499 			.size	= self->data_size,
500 		},
501 		.event_types = {
502 			.offset = self->event_offset,
503 			.size	= self->event_size,
504 		},
505 	};
506 
507 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
508 
509 	lseek(fd, 0, SEEK_SET);
510 	err = do_write(fd, &f_header, sizeof(f_header));
511 	if (err < 0) {
512 		pr_debug("failed to write perf header\n");
513 		return err;
514 	}
515 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
516 
517 	self->frozen = 1;
518 	return 0;
519 }
520 
521 static int do_read(int fd, void *buf, size_t size)
522 {
523 	while (size) {
524 		int ret = read(fd, buf, size);
525 
526 		if (ret <= 0)
527 			return -1;
528 
529 		size -= ret;
530 		buf += ret;
531 	}
532 
533 	return 0;
534 }
535 
536 static int perf_header__getbuffer64(struct perf_header *self,
537 				    int fd, void *buf, size_t size)
538 {
539 	if (do_read(fd, buf, size))
540 		return -1;
541 
542 	if (self->needs_swap)
543 		mem_bswap_64(buf, size);
544 
545 	return 0;
546 }
547 
548 int perf_header__process_sections(struct perf_header *self, int fd,
549 				  int (*process)(struct perf_file_section *self,
550 						 struct perf_header *ph,
551 						 int feat, int fd))
552 {
553 	struct perf_file_section *feat_sec;
554 	int nr_sections;
555 	int sec_size;
556 	int idx = 0;
557 	int err = -1, feat = 1;
558 
559 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
560 	if (!nr_sections)
561 		return 0;
562 
563 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
564 	if (!feat_sec)
565 		return -1;
566 
567 	sec_size = sizeof(*feat_sec) * nr_sections;
568 
569 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
570 
571 	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
572 		goto out_free;
573 
574 	err = 0;
575 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
576 		if (perf_header__has_feat(self, feat)) {
577 			struct perf_file_section *sec = &feat_sec[idx++];
578 
579 			err = process(sec, self, feat, fd);
580 			if (err < 0)
581 				break;
582 		}
583 		++feat;
584 	}
585 out_free:
586 	free(feat_sec);
587 	return err;
588 }
589 
590 int perf_file_header__read(struct perf_file_header *self,
591 			   struct perf_header *ph, int fd)
592 {
593 	lseek(fd, 0, SEEK_SET);
594 
595 	if (do_read(fd, self, sizeof(*self)) ||
596 	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
597 		return -1;
598 
599 	if (self->attr_size != sizeof(struct perf_file_attr)) {
600 		u64 attr_size = bswap_64(self->attr_size);
601 
602 		if (attr_size != sizeof(struct perf_file_attr))
603 			return -1;
604 
605 		mem_bswap_64(self, offsetof(struct perf_file_header,
606 					    adds_features));
607 		ph->needs_swap = true;
608 	}
609 
610 	if (self->size != sizeof(*self)) {
611 		/* Support the previous format */
612 		if (self->size == offsetof(typeof(*self), adds_features))
613 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
614 		else
615 			return -1;
616 	}
617 
618 	memcpy(&ph->adds_features, &self->adds_features,
619 	       sizeof(ph->adds_features));
620 	/*
621 	 * FIXME: hack that assumes that if we need swap the perf.data file
622 	 * may be coming from an arch with a different word-size, ergo different
623 	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
624 	 * safe to assume that we have a build-id section. Trace files probably
625 	 * have several other issues in this realm anyway...
626 	 */
627 	if (ph->needs_swap) {
628 		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
629 		perf_header__set_feat(ph, HEADER_BUILD_ID);
630 	}
631 
632 	ph->event_offset = self->event_types.offset;
633 	ph->event_size   = self->event_types.size;
634 	ph->data_offset  = self->data.offset;
635 	ph->data_size	 = self->data.size;
636 	return 0;
637 }
638 
639 static int perf_file_section__process(struct perf_file_section *self,
640 				      struct perf_header *ph,
641 				      int feat, int fd)
642 {
643 	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
644 		pr_debug("Failed to lseek to %Ld offset for feature %d, "
645 			 "continuing...\n", self->offset, feat);
646 		return 0;
647 	}
648 
649 	switch (feat) {
650 	case HEADER_TRACE_INFO:
651 		trace_report(fd);
652 		break;
653 
654 	case HEADER_BUILD_ID:
655 		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
656 			pr_debug("Failed to read buildids, continuing...\n");
657 		break;
658 	default:
659 		pr_debug("unknown feature %d, continuing...\n", feat);
660 	}
661 
662 	return 0;
663 }
664 
665 int perf_header__read(struct perf_header *self, int fd)
666 {
667 	struct perf_file_header	f_header;
668 	struct perf_file_attr	f_attr;
669 	u64			f_id;
670 	int nr_attrs, nr_ids, i, j;
671 
672 	if (perf_file_header__read(&f_header, self, fd) < 0) {
673 		pr_debug("incompatible file format\n");
674 		return -EINVAL;
675 	}
676 
677 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
678 	lseek(fd, f_header.attrs.offset, SEEK_SET);
679 
680 	for (i = 0; i < nr_attrs; i++) {
681 		struct perf_header_attr *attr;
682 		off_t tmp;
683 
684 		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
685 			goto out_errno;
686 
687 		tmp = lseek(fd, 0, SEEK_CUR);
688 
689 		attr = perf_header_attr__new(&f_attr.attr);
690 		if (attr == NULL)
691 			 return -ENOMEM;
692 
693 		nr_ids = f_attr.ids.size / sizeof(u64);
694 		lseek(fd, f_attr.ids.offset, SEEK_SET);
695 
696 		for (j = 0; j < nr_ids; j++) {
697 			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
698 				goto out_errno;
699 
700 			if (perf_header_attr__add_id(attr, f_id) < 0) {
701 				perf_header_attr__delete(attr);
702 				return -ENOMEM;
703 			}
704 		}
705 		if (perf_header__add_attr(self, attr) < 0) {
706 			perf_header_attr__delete(attr);
707 			return -ENOMEM;
708 		}
709 
710 		lseek(fd, tmp, SEEK_SET);
711 	}
712 
713 	if (f_header.event_types.size) {
714 		lseek(fd, f_header.event_types.offset, SEEK_SET);
715 		events = malloc(f_header.event_types.size);
716 		if (events == NULL)
717 			return -ENOMEM;
718 		if (perf_header__getbuffer64(self, fd, events,
719 					     f_header.event_types.size))
720 			goto out_errno;
721 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
722 	}
723 
724 	perf_header__process_sections(self, fd, perf_file_section__process);
725 
726 	lseek(fd, self->data_offset, SEEK_SET);
727 
728 	self->frozen = 1;
729 	return 0;
730 out_errno:
731 	return -errno;
732 }
733 
734 u64 perf_header__sample_type(struct perf_header *header)
735 {
736 	u64 type = 0;
737 	int i;
738 
739 	for (i = 0; i < header->attrs; i++) {
740 		struct perf_header_attr *attr = header->attr[i];
741 
742 		if (!type)
743 			type = attr->attr.sample_type;
744 		else if (type != attr->attr.sample_type)
745 			die("non matching sample_type");
746 	}
747 
748 	return type;
749 }
750 
751 struct perf_event_attr *
752 perf_header__find_attr(u64 id, struct perf_header *header)
753 {
754 	int i;
755 
756 	for (i = 0; i < header->attrs; i++) {
757 		struct perf_header_attr *attr = header->attr[i];
758 		int j;
759 
760 		for (j = 0; j < attr->ids; j++) {
761 			if (attr->id[j] == id)
762 				return &attr->attr;
763 		}
764 	}
765 
766 	return NULL;
767 }
768