xref: /openbmc/linux/tools/perf/util/header.c (revision b6dcefde)
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 "session.h"
12 #include "symbol.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 int perf_header__init(struct perf_header *self)
62 {
63 	self->size = 1;
64 	self->attr = malloc(sizeof(void *));
65 	return self->attr == NULL ? -ENOMEM : 0;
66 }
67 
68 void perf_header__exit(struct perf_header *self)
69 {
70 	int i;
71 	for (i = 0; i < self->attrs; ++i)
72                 perf_header_attr__delete(self->attr[i]);
73 	free(self->attr);
74 }
75 
76 int perf_header__add_attr(struct perf_header *self,
77 			  struct perf_header_attr *attr)
78 {
79 	if (self->frozen)
80 		return -1;
81 
82 	if (self->attrs == self->size) {
83 		int nsize = self->size * 2;
84 		struct perf_header_attr **nattr;
85 
86 		nattr = realloc(self->attr, nsize * sizeof(void *));
87 		if (nattr == NULL)
88 			return -1;
89 
90 		self->size = nsize;
91 		self->attr = nattr;
92 	}
93 
94 	self->attr[self->attrs++] = attr;
95 	return 0;
96 }
97 
98 #define MAX_EVENT_NAME 64
99 
100 struct perf_trace_event_type {
101 	u64	event_id;
102 	char	name[MAX_EVENT_NAME];
103 };
104 
105 static int event_count;
106 static struct perf_trace_event_type *events;
107 
108 void perf_header__push_event(u64 id, const char *name)
109 {
110 	if (strlen(name) > MAX_EVENT_NAME)
111 		pr_warning("Event %s will be truncated\n", name);
112 
113 	if (!events) {
114 		events = malloc(sizeof(struct perf_trace_event_type));
115 		if (!events)
116 			die("nomem");
117 	} else {
118 		events = realloc(events, (event_count + 1) * sizeof(struct perf_trace_event_type));
119 		if (!events)
120 			die("nomem");
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 }
127 
128 char *perf_header__find_event(u64 id)
129 {
130 	int i;
131 	for (i = 0 ; i < event_count; i++) {
132 		if (events[i].event_id == id)
133 			return events[i].name;
134 	}
135 	return NULL;
136 }
137 
138 static const char *__perf_magic = "PERFFILE";
139 
140 #define PERF_MAGIC	(*(u64 *)__perf_magic)
141 
142 struct perf_file_attr {
143 	struct perf_event_attr	attr;
144 	struct perf_file_section	ids;
145 };
146 
147 void perf_header__set_feat(struct perf_header *self, int feat)
148 {
149 	set_bit(feat, self->adds_features);
150 }
151 
152 bool perf_header__has_feat(const struct perf_header *self, int feat)
153 {
154 	return test_bit(feat, self->adds_features);
155 }
156 
157 static int do_write(int fd, const void *buf, size_t size)
158 {
159 	while (size) {
160 		int ret = write(fd, buf, size);
161 
162 		if (ret < 0)
163 			return -errno;
164 
165 		size -= ret;
166 		buf += ret;
167 	}
168 
169 	return 0;
170 }
171 
172 static int __dsos__write_buildid_table(struct list_head *head, int fd)
173 {
174 #define NAME_ALIGN	64
175 	struct dso *pos;
176 	static const char zero_buf[NAME_ALIGN];
177 
178 	list_for_each_entry(pos, head, node) {
179 		int err;
180 		struct build_id_event b;
181 		size_t len;
182 
183 		if (!pos->has_build_id)
184 			continue;
185 		len = pos->long_name_len + 1;
186 		len = ALIGN(len, NAME_ALIGN);
187 		memset(&b, 0, sizeof(b));
188 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
189 		b.header.size = sizeof(b) + len;
190 		err = do_write(fd, &b, sizeof(b));
191 		if (err < 0)
192 			return err;
193 		err = do_write(fd, pos->long_name, pos->long_name_len + 1);
194 		if (err < 0)
195 			return err;
196 		err = do_write(fd, zero_buf, len - pos->long_name_len - 1);
197 		if (err < 0)
198 			return err;
199 	}
200 
201 	return 0;
202 }
203 
204 static int dsos__write_buildid_table(int fd)
205 {
206 	int err = __dsos__write_buildid_table(&dsos__kernel, fd);
207 	if (err == 0)
208 		err = __dsos__write_buildid_table(&dsos__user, fd);
209 	return err;
210 }
211 
212 static int perf_header__adds_write(struct perf_header *self, int fd)
213 {
214 	int nr_sections;
215 	struct perf_file_section *feat_sec;
216 	int sec_size;
217 	u64 sec_start;
218 	int idx = 0, err;
219 
220 	if (dsos__read_build_ids())
221 		perf_header__set_feat(self, HEADER_BUILD_ID);
222 
223 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
224 	if (!nr_sections)
225 		return 0;
226 
227 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
228 	if (feat_sec == NULL)
229 		return -ENOMEM;
230 
231 	sec_size = sizeof(*feat_sec) * nr_sections;
232 
233 	sec_start = self->data_offset + self->data_size;
234 	lseek(fd, sec_start + sec_size, SEEK_SET);
235 
236 	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
237 		struct perf_file_section *trace_sec;
238 
239 		trace_sec = &feat_sec[idx++];
240 
241 		/* Write trace info */
242 		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
243 		read_tracing_data(fd, attrs, nr_counters);
244 		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
245 	}
246 
247 
248 	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
249 		struct perf_file_section *buildid_sec;
250 
251 		buildid_sec = &feat_sec[idx++];
252 
253 		/* Write build-ids */
254 		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
255 		err = dsos__write_buildid_table(fd);
256 		if (err < 0) {
257 			pr_debug("failed to write buildid table\n");
258 			goto out_free;
259 		}
260 		buildid_sec->size = lseek(fd, 0, SEEK_CUR) - buildid_sec->offset;
261 	}
262 
263 	lseek(fd, sec_start, SEEK_SET);
264 	err = do_write(fd, feat_sec, sec_size);
265 	if (err < 0)
266 		pr_debug("failed to write feature section\n");
267 out_free:
268 	free(feat_sec);
269 	return err;
270 }
271 
272 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
273 {
274 	struct perf_file_header f_header;
275 	struct perf_file_attr   f_attr;
276 	struct perf_header_attr	*attr;
277 	int i, err;
278 
279 	lseek(fd, sizeof(f_header), SEEK_SET);
280 
281 
282 	for (i = 0; i < self->attrs; i++) {
283 		attr = self->attr[i];
284 
285 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
286 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
287 		if (err < 0) {
288 			pr_debug("failed to write perf header\n");
289 			return err;
290 		}
291 	}
292 
293 
294 	self->attr_offset = lseek(fd, 0, SEEK_CUR);
295 
296 	for (i = 0; i < self->attrs; i++) {
297 		attr = self->attr[i];
298 
299 		f_attr = (struct perf_file_attr){
300 			.attr = attr->attr,
301 			.ids  = {
302 				.offset = attr->id_offset,
303 				.size   = attr->ids * sizeof(u64),
304 			}
305 		};
306 		err = do_write(fd, &f_attr, sizeof(f_attr));
307 		if (err < 0) {
308 			pr_debug("failed to write perf header attribute\n");
309 			return err;
310 		}
311 	}
312 
313 	self->event_offset = lseek(fd, 0, SEEK_CUR);
314 	self->event_size = event_count * sizeof(struct perf_trace_event_type);
315 	if (events) {
316 		err = do_write(fd, events, self->event_size);
317 		if (err < 0) {
318 			pr_debug("failed to write perf header events\n");
319 			return err;
320 		}
321 	}
322 
323 	self->data_offset = lseek(fd, 0, SEEK_CUR);
324 
325 	if (at_exit) {
326 		err = perf_header__adds_write(self, fd);
327 		if (err < 0)
328 			return err;
329 	}
330 
331 	f_header = (struct perf_file_header){
332 		.magic	   = PERF_MAGIC,
333 		.size	   = sizeof(f_header),
334 		.attr_size = sizeof(f_attr),
335 		.attrs = {
336 			.offset = self->attr_offset,
337 			.size   = self->attrs * sizeof(f_attr),
338 		},
339 		.data = {
340 			.offset = self->data_offset,
341 			.size	= self->data_size,
342 		},
343 		.event_types = {
344 			.offset = self->event_offset,
345 			.size	= self->event_size,
346 		},
347 	};
348 
349 	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
350 
351 	lseek(fd, 0, SEEK_SET);
352 	err = do_write(fd, &f_header, sizeof(f_header));
353 	if (err < 0) {
354 		pr_debug("failed to write perf header\n");
355 		return err;
356 	}
357 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
358 
359 	self->frozen = 1;
360 	return 0;
361 }
362 
363 static void do_read(int fd, void *buf, size_t size)
364 {
365 	while (size) {
366 		int ret = read(fd, buf, size);
367 
368 		if (ret < 0)
369 			die("failed to read");
370 		if (ret == 0)
371 			die("failed to read: missing data");
372 
373 		size -= ret;
374 		buf += ret;
375 	}
376 }
377 
378 int perf_header__process_sections(struct perf_header *self, int fd,
379 				  int (*process)(struct perf_file_section *self,
380 						 int feat, int fd))
381 {
382 	struct perf_file_section *feat_sec;
383 	int nr_sections;
384 	int sec_size;
385 	int idx = 0;
386 	int err = 0, feat = 1;
387 
388 	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
389 	if (!nr_sections)
390 		return 0;
391 
392 	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
393 	if (!feat_sec)
394 		return -1;
395 
396 	sec_size = sizeof(*feat_sec) * nr_sections;
397 
398 	lseek(fd, self->data_offset + self->data_size, SEEK_SET);
399 
400 	do_read(fd, feat_sec, sec_size);
401 
402 	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
403 		if (perf_header__has_feat(self, feat)) {
404 			struct perf_file_section *sec = &feat_sec[idx++];
405 
406 			err = process(sec, feat, fd);
407 			if (err < 0)
408 				break;
409 		}
410 		++feat;
411 	}
412 
413 	free(feat_sec);
414 	return err;
415 };
416 
417 int perf_file_header__read(struct perf_file_header *self,
418 			   struct perf_header *ph, int fd)
419 {
420 	lseek(fd, 0, SEEK_SET);
421 	do_read(fd, self, sizeof(*self));
422 
423 	if (self->magic     != PERF_MAGIC ||
424 	    self->attr_size != sizeof(struct perf_file_attr))
425 		return -1;
426 
427 	if (self->size != sizeof(*self)) {
428 		/* Support the previous format */
429 		if (self->size == offsetof(typeof(*self), adds_features))
430 			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
431 		else
432 			return -1;
433 	}
434 
435 	memcpy(&ph->adds_features, &self->adds_features,
436 	       sizeof(self->adds_features));
437 
438 	ph->event_offset = self->event_types.offset;
439 	ph->event_size	 = self->event_types.size;
440 	ph->data_offset	 = self->data.offset;
441 	ph->data_size	 = self->data.size;
442 	return 0;
443 }
444 
445 static int perf_file_section__process(struct perf_file_section *self,
446 				      int feat, int fd)
447 {
448 	if (lseek(fd, self->offset, SEEK_SET) < 0) {
449 		pr_debug("Failed to lseek to %Ld offset for feature %d, "
450 			 "continuing...\n", self->offset, feat);
451 		return 0;
452 	}
453 
454 	switch (feat) {
455 	case HEADER_TRACE_INFO:
456 		trace_report(fd);
457 		break;
458 
459 	case HEADER_BUILD_ID:
460 		if (perf_header__read_build_ids(fd, self->offset, self->size))
461 			pr_debug("Failed to read buildids, continuing...\n");
462 		break;
463 	default:
464 		pr_debug("unknown feature %d, continuing...\n", feat);
465 	}
466 
467 	return 0;
468 }
469 
470 int perf_header__read(struct perf_header *self, int fd)
471 {
472 	struct perf_file_header f_header;
473 	struct perf_file_attr	f_attr;
474 	u64			f_id;
475 	int nr_attrs, nr_ids, i, j;
476 
477 	if (perf_file_header__read(&f_header, self, fd) < 0) {
478 		pr_debug("incompatible file format\n");
479 		return -EINVAL;
480 	}
481 
482 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
483 	lseek(fd, f_header.attrs.offset, SEEK_SET);
484 
485 	for (i = 0; i < nr_attrs; i++) {
486 		struct perf_header_attr *attr;
487 		off_t tmp;
488 
489 		do_read(fd, &f_attr, sizeof(f_attr));
490 		tmp = lseek(fd, 0, SEEK_CUR);
491 
492 		attr = perf_header_attr__new(&f_attr.attr);
493 		if (attr == NULL)
494 			 return -ENOMEM;
495 
496 		nr_ids = f_attr.ids.size / sizeof(u64);
497 		lseek(fd, f_attr.ids.offset, SEEK_SET);
498 
499 		for (j = 0; j < nr_ids; j++) {
500 			do_read(fd, &f_id, sizeof(f_id));
501 
502 			if (perf_header_attr__add_id(attr, f_id) < 0) {
503 				perf_header_attr__delete(attr);
504 				return -ENOMEM;
505 			}
506 		}
507 		if (perf_header__add_attr(self, attr) < 0) {
508 			perf_header_attr__delete(attr);
509 			return -ENOMEM;
510 		}
511 
512 		lseek(fd, tmp, SEEK_SET);
513 	}
514 
515 	if (f_header.event_types.size) {
516 		lseek(fd, f_header.event_types.offset, SEEK_SET);
517 		events = malloc(f_header.event_types.size);
518 		if (events == NULL)
519 			return -ENOMEM;
520 		do_read(fd, events, f_header.event_types.size);
521 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
522 	}
523 
524 	perf_header__process_sections(self, fd, perf_file_section__process);
525 
526 	lseek(fd, self->data_offset, SEEK_SET);
527 
528 	self->frozen = 1;
529 	return 0;
530 }
531 
532 u64 perf_header__sample_type(struct perf_header *header)
533 {
534 	u64 type = 0;
535 	int i;
536 
537 	for (i = 0; i < header->attrs; i++) {
538 		struct perf_header_attr *attr = header->attr[i];
539 
540 		if (!type)
541 			type = attr->attr.sample_type;
542 		else if (type != attr->attr.sample_type)
543 			die("non matching sample_type");
544 	}
545 
546 	return type;
547 }
548 
549 struct perf_event_attr *
550 perf_header__find_attr(u64 id, struct perf_header *header)
551 {
552 	int i;
553 
554 	for (i = 0; i < header->attrs; i++) {
555 		struct perf_header_attr *attr = header->attr[i];
556 		int j;
557 
558 		for (j = 0; j < attr->ids; j++) {
559 			if (attr->id[j] == id)
560 				return &attr->attr;
561 		}
562 	}
563 
564 	return NULL;
565 }
566