xref: /linux/tools/perf/util/header.c (revision 273b281fa22c293963ee3e6eec418f5dda2dbc83)
1 #include <sys/types.h>
2 #include <unistd.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <linux/list.h>
6 
7 #include "util.h"
8 #include "header.h"
9 #include "../perf.h"
10 #include "trace-event.h"
11 #include "symbol.h"
12 #include "data_map.h"
13 #include "debug.h"
14 
15 /*
16  * Create new perf.data header attribute:
17  */
18 struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
19 {
20 	struct perf_header_attr *self = malloc(sizeof(*self));
21 
22 	if (self != NULL) {
23 		self->attr = *attr;
24 		self->ids  = 0;
25 		self->size = 1;
26 		self->id   = malloc(sizeof(u64));
27 		if (self->id == NULL) {
28 			free(self);
29 			self = NULL;
30 		}
31 	}
32 
33 	return self;
34 }
35 
36 void perf_header_attr__delete(struct perf_header_attr *self)
37 {
38 	free(self->id);
39 	free(self);
40 }
41 
42 int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
43 {
44 	int pos = self->ids;
45 
46 	self->ids++;
47 	if (self->ids > self->size) {
48 		int nsize = self->size * 2;
49 		u64 *nid = realloc(self->id, nsize * sizeof(u64));
50 
51 		if (nid == NULL)
52 			return -1;
53 
54 		self->size = nsize;
55 		self->id = nid;
56 	}
57 	self->id[pos] = id;
58 	return 0;
59 }
60 
61 /*
62  * Create new perf.data header:
63  */
64 struct perf_header *perf_header__new(void)
65 {
66 	struct perf_header *self = zalloc(sizeof(*self));
67 
68 	if (self != NULL) {
69 		self->size = 1;
70 		self->attr = malloc(sizeof(void *));
71 
72 		if (self->attr == NULL) {
73 			free(self);
74 			self = NULL;
75 		}
76 	}
77 
78 	return self;
79 }
80 
81 void perf_header__delete(struct perf_header *self)
82 {
83 	int i;
84 
85 	for (i = 0; i < self->attrs; ++i)
86 		perf_header_attr__delete(self->attr[i]);
87 
88 	free(self->attr);
89 	free(self);
90 }
91 
92 int perf_header__add_attr(struct perf_header *self,
93 			  struct perf_header_attr *attr)
94 {
95 	if (self->frozen)
96 		return -1;
97 
98 	if (self->attrs == self->size) {
99 		int nsize = self->size * 2;
100 		struct perf_header_attr **nattr;
101 
102 		nattr = realloc(self->attr, nsize * sizeof(void *));
103 		if (nattr == NULL)
104 			return -1;
105 
106 		self->size = nsize;
107 		self->attr = nattr;
108 	}
109 
110 	self->attr[self->attrs++] = attr;
111 	return 0;
112 }
113 
114 #define MAX_EVENT_NAME 64
115 
116 struct perf_trace_event_type {
117 	u64	event_id;
118 	char	name[MAX_EVENT_NAME];
119 };
120 
121 static int event_count;
122 static struct perf_trace_event_type *events;
123 
124 void perf_header__push_event(u64 id, const char *name)
125 {
126 	if (strlen(name) > MAX_EVENT_NAME)
127 		pr_warning("Event %s will be truncated\n", name);
128 
129 	if (!events) {
130 		events = malloc(sizeof(struct perf_trace_event_type));
131 		if (!events)
132 			die("nomem");
133 	} else {
134 		events = realloc(events, (event_count + 1) * sizeof(struct perf_trace_event_type));
135 		if (!events)
136 			die("nomem");
137 	}
138 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
139 	events[event_count].event_id = id;
140 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
141 	event_count++;
142 }
143 
144 char *perf_header__find_event(u64 id)
145 {
146 	int i;
147 	for (i = 0 ; i < event_count; i++) {
148 		if (events[i].event_id == id)
149 			return events[i].name;
150 	}
151 	return NULL;
152 }
153 
154 static const char *__perf_magic = "PERFFILE";
155 
156 #define PERF_MAGIC	(*(u64 *)__perf_magic)
157 
158 struct perf_file_attr {
159 	struct perf_event_attr	attr;
160 	struct perf_file_section	ids;
161 };
162 
163 void perf_header__set_feat(struct perf_header *self, int feat)
164 {
165 	set_bit(feat, self->adds_features);
166 }
167 
168 bool perf_header__has_feat(const struct perf_header *self, int feat)
169 {
170 	return test_bit(feat, self->adds_features);
171 }
172 
173 static int do_write(int fd, const void *buf, size_t size)
174 {
175 	while (size) {
176 		int ret = write(fd, buf, size);
177 
178 		if (ret < 0)
179 			return -errno;
180 
181 		size -= ret;
182 		buf += ret;
183 	}
184 
185 	return 0;
186 }
187 
188 static int __dsos__write_buildid_table(struct list_head *head, int fd)
189 {
190 #define NAME_ALIGN	64
191 	struct dso *pos;
192 	static const char zero_buf[NAME_ALIGN];
193 
194 	list_for_each_entry(pos, head, node) {
195 		int err;
196 		struct build_id_event b;
197 		size_t len;
198 
199 		if (!pos->has_build_id)
200 			continue;
201 		len = pos->long_name_len + 1;
202 		len = ALIGN(len, NAME_ALIGN);
203 		memset(&b, 0, sizeof(b));
204 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
205 		b.header.size = sizeof(b) + len;
206 		err = do_write(fd, &b, sizeof(b));
207 		if (err < 0)
208 			return err;
209 		err = do_write(fd, pos->long_name, pos->long_name_len + 1);
210 		if (err < 0)
211 			return err;
212 		err = do_write(fd, zero_buf, len - pos->long_name_len - 1);
213 		if (err < 0)
214 			return err;
215 	}
216 
217 	return 0;
218 }
219 
220 static int dsos__write_buildid_table(int fd)
221 {
222 	int err = __dsos__write_buildid_table(&dsos__kernel, fd);
223 	if (err == 0)
224 		err = __dsos__write_buildid_table(&dsos__user, fd);
225 	return err;
226 }
227 
228 static int perf_header__adds_write(struct perf_header *self, int fd)
229 {
230 	int nr_sections;
231 	struct perf_file_section *feat_sec;
232 	int sec_size;
233 	u64 sec_start;
234 	int idx = 0, err;
235 
236 	if (dsos__read_build_ids())
237 		perf_header__set_feat(self, HEADER_BUILD_ID);
238 
239 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
240 	if (!nr_sections)
241 		return 0;
242 
243 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
244 	if (feat_sec == NULL)
245 		return -ENOMEM;
246 
247 	sec_size = sizeof(*feat_sec) * nr_sections;
248 
249 	sec_start = self->data_offset + self->data_size;
250 	lseek(fd, sec_start + sec_size, SEEK_SET);
251 
252 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
253 		struct perf_file_section *trace_sec;
254 
255 		trace_sec = &feat_sec[idx++];
256 
257 		/* Write trace info */
258 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
259 		read_tracing_data(fd, attrs, nr_counters);
260 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
261 	}
262 
263 
264 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
265 		struct perf_file_section *buildid_sec;
266 
267 		buildid_sec = &feat_sec[idx++];
268 
269 		/* Write build-ids */
270 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
271 		err = dsos__write_buildid_table(fd);
272 		if (err < 0) {
273 			pr_debug("failed to write buildid table\n");
274 			goto out_free;
275 		}
276 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) - buildid_sec->offset;
277 	}
278 
279 	lseek(fd, sec_start, SEEK_SET);
280 	err = do_write(fd, feat_sec, sec_size);
281 	if (err < 0)
282 		pr_debug("failed to write feature section\n");
283 out_free:
284 	free(feat_sec);
285 	return err;
286 }
287 
288 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
289 {
290 	struct perf_file_header f_header;
291 	struct perf_file_attr   f_attr;
292 	struct perf_header_attr	*attr;
293 	int i, err;
294 
295 	lseek(fd, sizeof(f_header), SEEK_SET);
296 
297 
298 	for (i = 0; i < self->attrs; i++) {
299 		attr = self->attr[i];
300 
301 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
302 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
303 		if (err < 0) {
304 			pr_debug("failed to write perf header\n");
305 			return err;
306 		}
307 	}
308 
309 
310 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
311 
312 	for (i = 0; i < self->attrs; i++) {
313 		attr = self->attr[i];
314 
315 		f_attr = (struct perf_file_attr){
316 			.attr = attr->attr,
317 			.ids  = {
318 				.offset = attr->id_offset,
319 				.size   = attr->ids * sizeof(u64),
320 			}
321 		};
322 		err = do_write(fd, &f_attr, sizeof(f_attr));
323 		if (err < 0) {
324 			pr_debug("failed to write perf header attribute\n");
325 			return err;
326 		}
327 	}
328 
329 	self->event_offset = lseek(fd, 0, SEEK_CUR);
330 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
331 	if (events) {
332 		err = do_write(fd, events, self->event_size);
333 		if (err < 0) {
334 			pr_debug("failed to write perf header events\n");
335 			return err;
336 		}
337 	}
338 
339 	self->data_offset = lseek(fd, 0, SEEK_CUR);
340 
341 	if (at_exit) {
342 		err = perf_header__adds_write(self, fd);
343 		if (err < 0)
344 			return err;
345 	}
346 
347 	f_header = (struct perf_file_header){
348 		.magic	   = PERF_MAGIC,
349 		.size	   = sizeof(f_header),
350 		.attr_size = sizeof(f_attr),
351 		.attrs = {
352 			.offset = self->attr_offset,
353 			.size   = self->attrs * sizeof(f_attr),
354 		},
355 		.data = {
356 			.offset = self->data_offset,
357 			.size	= self->data_size,
358 		},
359 		.event_types = {
360 			.offset = self->event_offset,
361 			.size	= self->event_size,
362 		},
363 	};
364 
365 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
366 
367 	lseek(fd, 0, SEEK_SET);
368 	err = do_write(fd, &f_header, sizeof(f_header));
369 	if (err < 0) {
370 		pr_debug("failed to write perf header\n");
371 		return err;
372 	}
373 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
374 
375 	self->frozen = 1;
376 	return 0;
377 }
378 
379 static void do_read(int fd, void *buf, size_t size)
380 {
381 	while (size) {
382 		int ret = read(fd, buf, size);
383 
384 		if (ret < 0)
385 			die("failed to read");
386 		if (ret == 0)
387 			die("failed to read: missing data");
388 
389 		size -= ret;
390 		buf += ret;
391 	}
392 }
393 
394 int perf_header__process_sections(struct perf_header *self, int fd,
395 				  int (*process)(struct perf_file_section *self,
396 						 int feat, int fd))
397 {
398 	struct perf_file_section *feat_sec;
399 	int nr_sections;
400 	int sec_size;
401 	int idx = 0;
402 	int err = 0, feat = 1;
403 
404 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
405 	if (!nr_sections)
406 		return 0;
407 
408 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
409 	if (!feat_sec)
410 		return -1;
411 
412 	sec_size = sizeof(*feat_sec) * nr_sections;
413 
414 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
415 
416 	do_read(fd, feat_sec, sec_size);
417 
418 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
419 		if (perf_header__has_feat(self, feat)) {
420 			struct perf_file_section *sec = &feat_sec[idx++];
421 
422 			err = process(sec, feat, fd);
423 			if (err < 0)
424 				break;
425 		}
426 		++feat;
427 	}
428 
429 	free(feat_sec);
430 	return err;
431 };
432 
433 int perf_file_header__read(struct perf_file_header *self,
434 			   struct perf_header *ph, int fd)
435 {
436 	lseek(fd, 0, SEEK_SET);
437 	do_read(fd, self, sizeof(*self));
438 
439 	if (self->magic     != PERF_MAGIC ||
440 	    self->attr_size != sizeof(struct perf_file_attr))
441 		return -1;
442 
443 	if (self->size != sizeof(*self)) {
444 		/* Support the previous format */
445 		if (self->size == offsetof(typeof(*self), adds_features))
446 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
447 		else
448 			return -1;
449 	}
450 
451 	memcpy(&ph->adds_features, &self->adds_features,
452 	       sizeof(self->adds_features));
453 
454 	ph->event_offset = self->event_types.offset;
455 	ph->event_size	 = self->event_types.size;
456 	ph->data_offset	 = self->data.offset;
457 	ph->data_size	 = self->data.size;
458 	return 0;
459 }
460 
461 static int perf_file_section__process(struct perf_file_section *self,
462 				      int feat, int fd)
463 {
464 	if (lseek(fd, self->offset, SEEK_SET) < 0) {
465 		pr_debug("Failed to lseek to %Ld offset for feature %d, "
466 			 "continuing...\n", self->offset, feat);
467 		return 0;
468 	}
469 
470 	switch (feat) {
471 	case HEADER_TRACE_INFO:
472 		trace_report(fd);
473 		break;
474 
475 	case HEADER_BUILD_ID:
476 		if (perf_header__read_build_ids(fd, self->offset, self->size))
477 			pr_debug("Failed to read buildids, continuing...\n");
478 		break;
479 	default:
480 		pr_debug("unknown feature %d, continuing...\n", feat);
481 	}
482 
483 	return 0;
484 }
485 
486 int perf_header__read(struct perf_header *self, int fd)
487 {
488 	struct perf_file_header f_header;
489 	struct perf_file_attr	f_attr;
490 	u64			f_id;
491 	int nr_attrs, nr_ids, i, j;
492 
493 	if (perf_file_header__read(&f_header, self, fd) < 0) {
494 		pr_debug("incompatible file format\n");
495 		return -EINVAL;
496 	}
497 
498 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
499 	lseek(fd, f_header.attrs.offset, SEEK_SET);
500 
501 	for (i = 0; i < nr_attrs; i++) {
502 		struct perf_header_attr *attr;
503 		off_t tmp;
504 
505 		do_read(fd, &f_attr, sizeof(f_attr));
506 		tmp = lseek(fd, 0, SEEK_CUR);
507 
508 		attr = perf_header_attr__new(&f_attr.attr);
509 		if (attr == NULL)
510 			 return -ENOMEM;
511 
512 		nr_ids = f_attr.ids.size / sizeof(u64);
513 		lseek(fd, f_attr.ids.offset, SEEK_SET);
514 
515 		for (j = 0; j < nr_ids; j++) {
516 			do_read(fd, &f_id, sizeof(f_id));
517 
518 			if (perf_header_attr__add_id(attr, f_id) < 0) {
519 				perf_header_attr__delete(attr);
520 				return -ENOMEM;
521 			}
522 		}
523 		if (perf_header__add_attr(self, attr) < 0) {
524 			perf_header_attr__delete(attr);
525 			return -ENOMEM;
526 		}
527 
528 		lseek(fd, tmp, SEEK_SET);
529 	}
530 
531 	if (f_header.event_types.size) {
532 		lseek(fd, f_header.event_types.offset, SEEK_SET);
533 		events = malloc(f_header.event_types.size);
534 		if (events == NULL)
535 			return -ENOMEM;
536 		do_read(fd, events, f_header.event_types.size);
537 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
538 	}
539 
540 	perf_header__process_sections(self, fd, perf_file_section__process);
541 
542 	lseek(fd, self->data_offset, SEEK_SET);
543 
544 	self->frozen = 1;
545 	return 0;
546 }
547 
548 u64 perf_header__sample_type(struct perf_header *header)
549 {
550 	u64 type = 0;
551 	int i;
552 
553 	for (i = 0; i < header->attrs; i++) {
554 		struct perf_header_attr *attr = header->attr[i];
555 
556 		if (!type)
557 			type = attr->attr.sample_type;
558 		else if (type != attr->attr.sample_type)
559 			die("non matching sample_type");
560 	}
561 
562 	return type;
563 }
564 
565 struct perf_event_attr *
566 perf_header__find_attr(u64 id, struct perf_header *header)
567 {
568 	int i;
569 
570 	for (i = 0; i < header->attrs; i++) {
571 		struct perf_header_attr *attr = header->attr[i];
572 		int j;
573 
574 		for (j = 0; j < attr->ids; j++) {
575 			if (attr->id[j] == id)
576 				return &attr->attr;
577 		}
578 	}
579 
580 	return NULL;
581 }
582