xref: /openbmc/linux/tools/perf/util/session.c (revision 8dc58101f2c838355d44402aa77646649d10dbec)
1 #define _FILE_OFFSET_BITS 64
2 
3 #include <linux/kernel.h>
4 
5 #include <byteswap.h>
6 #include <unistd.h>
7 #include <sys/types.h>
8 
9 #include "session.h"
10 #include "sort.h"
11 #include "util.h"
12 
13 static int perf_session__open(struct perf_session *self, bool force)
14 {
15 	struct stat input_stat;
16 
17 	if (!strcmp(self->filename, "-")) {
18 		self->fd_pipe = true;
19 		self->fd = STDIN_FILENO;
20 
21 		if (perf_header__read(self, self->fd) < 0)
22 			pr_err("incompatible file format");
23 
24 		return 0;
25 	}
26 
27 	self->fd = open(self->filename, O_RDONLY);
28 	if (self->fd < 0) {
29 		pr_err("failed to open file: %s", self->filename);
30 		if (!strcmp(self->filename, "perf.data"))
31 			pr_err("  (try 'perf record' first)");
32 		pr_err("\n");
33 		return -errno;
34 	}
35 
36 	if (fstat(self->fd, &input_stat) < 0)
37 		goto out_close;
38 
39 	if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
40 		pr_err("file %s not owned by current user or root\n",
41 		       self->filename);
42 		goto out_close;
43 	}
44 
45 	if (!input_stat.st_size) {
46 		pr_info("zero-sized file (%s), nothing to do!\n",
47 			self->filename);
48 		goto out_close;
49 	}
50 
51 	if (perf_header__read(self, self->fd) < 0) {
52 		pr_err("incompatible file format");
53 		goto out_close;
54 	}
55 
56 	self->size = input_stat.st_size;
57 	return 0;
58 
59 out_close:
60 	close(self->fd);
61 	self->fd = -1;
62 	return -1;
63 }
64 
65 void perf_session__update_sample_type(struct perf_session *self)
66 {
67 	self->sample_type = perf_header__sample_type(&self->header);
68 }
69 
70 struct perf_session *perf_session__new(const char *filename, int mode, bool force)
71 {
72 	size_t len = filename ? strlen(filename) + 1 : 0;
73 	struct perf_session *self = zalloc(sizeof(*self) + len);
74 
75 	if (self == NULL)
76 		goto out;
77 
78 	if (perf_header__init(&self->header) < 0)
79 		goto out_free;
80 
81 	memcpy(self->filename, filename, len);
82 	self->threads = RB_ROOT;
83 	self->stats_by_id = RB_ROOT;
84 	self->last_match = NULL;
85 	self->mmap_window = 32;
86 	self->cwd = NULL;
87 	self->cwdlen = 0;
88 	self->unknown_events = 0;
89 	map_groups__init(&self->kmaps);
90 
91 	if (mode == O_RDONLY) {
92 		if (perf_session__open(self, force) < 0)
93 			goto out_delete;
94 	} else if (mode == O_WRONLY) {
95 		/*
96 		 * In O_RDONLY mode this will be performed when reading the
97 		 * kernel MMAP event, in event__process_mmap().
98 		 */
99 		if (perf_session__create_kernel_maps(self) < 0)
100 			goto out_delete;
101 	}
102 
103 	perf_session__update_sample_type(self);
104 out:
105 	return self;
106 out_free:
107 	free(self);
108 	return NULL;
109 out_delete:
110 	perf_session__delete(self);
111 	return NULL;
112 }
113 
114 void perf_session__delete(struct perf_session *self)
115 {
116 	perf_header__exit(&self->header);
117 	close(self->fd);
118 	free(self->cwd);
119 	free(self);
120 }
121 
122 static bool symbol__match_parent_regex(struct symbol *sym)
123 {
124 	if (sym->name && !regexec(&parent_regex, sym->name, 0, NULL, 0))
125 		return 1;
126 
127 	return 0;
128 }
129 
130 struct map_symbol *perf_session__resolve_callchain(struct perf_session *self,
131 						   struct thread *thread,
132 						   struct ip_callchain *chain,
133 						   struct symbol **parent)
134 {
135 	u8 cpumode = PERF_RECORD_MISC_USER;
136 	unsigned int i;
137 	struct map_symbol *syms = calloc(chain->nr, sizeof(*syms));
138 
139 	if (!syms)
140 		return NULL;
141 
142 	for (i = 0; i < chain->nr; i++) {
143 		u64 ip = chain->ips[i];
144 		struct addr_location al;
145 
146 		if (ip >= PERF_CONTEXT_MAX) {
147 			switch (ip) {
148 			case PERF_CONTEXT_HV:
149 				cpumode = PERF_RECORD_MISC_HYPERVISOR;	break;
150 			case PERF_CONTEXT_KERNEL:
151 				cpumode = PERF_RECORD_MISC_KERNEL;	break;
152 			case PERF_CONTEXT_USER:
153 				cpumode = PERF_RECORD_MISC_USER;	break;
154 			default:
155 				break;
156 			}
157 			continue;
158 		}
159 
160 		thread__find_addr_location(thread, self, cpumode,
161 					   MAP__FUNCTION, ip, &al, NULL);
162 		if (al.sym != NULL) {
163 			if (sort__has_parent && !*parent &&
164 			    symbol__match_parent_regex(al.sym))
165 				*parent = al.sym;
166 			if (!symbol_conf.use_callchain)
167 				break;
168 			syms[i].map = al.map;
169 			syms[i].sym = al.sym;
170 		}
171 	}
172 
173 	return syms;
174 }
175 
176 static int process_event_stub(event_t *event __used,
177 			      struct perf_session *session __used)
178 {
179 	dump_printf(": unhandled!\n");
180 	return 0;
181 }
182 
183 static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
184 {
185 	if (handler->sample == NULL)
186 		handler->sample = process_event_stub;
187 	if (handler->mmap == NULL)
188 		handler->mmap = process_event_stub;
189 	if (handler->comm == NULL)
190 		handler->comm = process_event_stub;
191 	if (handler->fork == NULL)
192 		handler->fork = process_event_stub;
193 	if (handler->exit == NULL)
194 		handler->exit = process_event_stub;
195 	if (handler->lost == NULL)
196 		handler->lost = process_event_stub;
197 	if (handler->read == NULL)
198 		handler->read = process_event_stub;
199 	if (handler->throttle == NULL)
200 		handler->throttle = process_event_stub;
201 	if (handler->unthrottle == NULL)
202 		handler->unthrottle = process_event_stub;
203 }
204 
205 static const char *event__name[] = {
206 	[0]			 = "TOTAL",
207 	[PERF_RECORD_MMAP]	 = "MMAP",
208 	[PERF_RECORD_LOST]	 = "LOST",
209 	[PERF_RECORD_COMM]	 = "COMM",
210 	[PERF_RECORD_EXIT]	 = "EXIT",
211 	[PERF_RECORD_THROTTLE]	 = "THROTTLE",
212 	[PERF_RECORD_UNTHROTTLE] = "UNTHROTTLE",
213 	[PERF_RECORD_FORK]	 = "FORK",
214 	[PERF_RECORD_READ]	 = "READ",
215 	[PERF_RECORD_SAMPLE]	 = "SAMPLE",
216 };
217 
218 unsigned long event__total[PERF_RECORD_HEADER_MAX];
219 
220 void event__print_totals(void)
221 {
222 	int i;
223 	for (i = 0; i < PERF_RECORD_HEADER_MAX; ++i) {
224 		if (!event__name[i])
225 			continue;
226 		pr_info("%10s events: %10ld\n",
227 			event__name[i], event__total[i]);
228 	}
229 }
230 
231 void mem_bswap_64(void *src, int byte_size)
232 {
233 	u64 *m = src;
234 
235 	while (byte_size > 0) {
236 		*m = bswap_64(*m);
237 		byte_size -= sizeof(u64);
238 		++m;
239 	}
240 }
241 
242 static void event__all64_swap(event_t *self)
243 {
244 	struct perf_event_header *hdr = &self->header;
245 	mem_bswap_64(hdr + 1, self->header.size - sizeof(*hdr));
246 }
247 
248 static void event__comm_swap(event_t *self)
249 {
250 	self->comm.pid = bswap_32(self->comm.pid);
251 	self->comm.tid = bswap_32(self->comm.tid);
252 }
253 
254 static void event__mmap_swap(event_t *self)
255 {
256 	self->mmap.pid	 = bswap_32(self->mmap.pid);
257 	self->mmap.tid	 = bswap_32(self->mmap.tid);
258 	self->mmap.start = bswap_64(self->mmap.start);
259 	self->mmap.len	 = bswap_64(self->mmap.len);
260 	self->mmap.pgoff = bswap_64(self->mmap.pgoff);
261 }
262 
263 static void event__task_swap(event_t *self)
264 {
265 	self->fork.pid	= bswap_32(self->fork.pid);
266 	self->fork.tid	= bswap_32(self->fork.tid);
267 	self->fork.ppid	= bswap_32(self->fork.ppid);
268 	self->fork.ptid	= bswap_32(self->fork.ptid);
269 	self->fork.time	= bswap_64(self->fork.time);
270 }
271 
272 static void event__read_swap(event_t *self)
273 {
274 	self->read.pid		= bswap_32(self->read.pid);
275 	self->read.tid		= bswap_32(self->read.tid);
276 	self->read.value	= bswap_64(self->read.value);
277 	self->read.time_enabled	= bswap_64(self->read.time_enabled);
278 	self->read.time_running	= bswap_64(self->read.time_running);
279 	self->read.id		= bswap_64(self->read.id);
280 }
281 
282 typedef void (*event__swap_op)(event_t *self);
283 
284 static event__swap_op event__swap_ops[] = {
285 	[PERF_RECORD_MMAP]   = event__mmap_swap,
286 	[PERF_RECORD_COMM]   = event__comm_swap,
287 	[PERF_RECORD_FORK]   = event__task_swap,
288 	[PERF_RECORD_EXIT]   = event__task_swap,
289 	[PERF_RECORD_LOST]   = event__all64_swap,
290 	[PERF_RECORD_READ]   = event__read_swap,
291 	[PERF_RECORD_SAMPLE] = event__all64_swap,
292 	[PERF_RECORD_HEADER_MAX]    = NULL,
293 };
294 
295 static int perf_session__process_event(struct perf_session *self,
296 				       event_t *event,
297 				       struct perf_event_ops *ops,
298 				       u64 offset, u64 head)
299 {
300 	trace_event(event);
301 
302 	if (event->header.type < PERF_RECORD_HEADER_MAX) {
303 		dump_printf("%#Lx [%#x]: PERF_RECORD_%s",
304 			    offset + head, event->header.size,
305 			    event__name[event->header.type]);
306 		++event__total[0];
307 		++event__total[event->header.type];
308 	}
309 
310 	if (self->header.needs_swap && event__swap_ops[event->header.type])
311 		event__swap_ops[event->header.type](event);
312 
313 	switch (event->header.type) {
314 	case PERF_RECORD_SAMPLE:
315 		return ops->sample(event, self);
316 	case PERF_RECORD_MMAP:
317 		return ops->mmap(event, self);
318 	case PERF_RECORD_COMM:
319 		return ops->comm(event, self);
320 	case PERF_RECORD_FORK:
321 		return ops->fork(event, self);
322 	case PERF_RECORD_EXIT:
323 		return ops->exit(event, self);
324 	case PERF_RECORD_LOST:
325 		return ops->lost(event, self);
326 	case PERF_RECORD_READ:
327 		return ops->read(event, self);
328 	case PERF_RECORD_THROTTLE:
329 		return ops->throttle(event, self);
330 	case PERF_RECORD_UNTHROTTLE:
331 		return ops->unthrottle(event, self);
332 	default:
333 		self->unknown_events++;
334 		return -1;
335 	}
336 }
337 
338 void perf_event_header__bswap(struct perf_event_header *self)
339 {
340 	self->type = bswap_32(self->type);
341 	self->misc = bswap_16(self->misc);
342 	self->size = bswap_16(self->size);
343 }
344 
345 int perf_header__read_build_ids(struct perf_header *self,
346 				int input, u64 offset, u64 size)
347 {
348 	struct build_id_event bev;
349 	char filename[PATH_MAX];
350 	u64 limit = offset + size;
351 	int err = -1;
352 
353 	while (offset < limit) {
354 		struct dso *dso;
355 		ssize_t len;
356 		struct list_head *head = &dsos__user;
357 
358 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
359 			goto out;
360 
361 		if (self->needs_swap)
362 			perf_event_header__bswap(&bev.header);
363 
364 		len = bev.header.size - sizeof(bev);
365 		if (read(input, filename, len) != len)
366 			goto out;
367 
368 		if (bev.header.misc & PERF_RECORD_MISC_KERNEL)
369 			head = &dsos__kernel;
370 
371 		dso = __dsos__findnew(head, filename);
372 		if (dso != NULL) {
373 			dso__set_build_id(dso, &bev.build_id);
374 			if (head == &dsos__kernel && filename[0] == '[')
375 				dso->kernel = 1;
376 		}
377 
378 		offset += bev.header.size;
379 	}
380 	err = 0;
381 out:
382 	return err;
383 }
384 
385 static struct thread *perf_session__register_idle_thread(struct perf_session *self)
386 {
387 	struct thread *thread = perf_session__findnew(self, 0);
388 
389 	if (thread == NULL || thread__set_comm(thread, "swapper")) {
390 		pr_err("problem inserting idle task.\n");
391 		thread = NULL;
392 	}
393 
394 	return thread;
395 }
396 
397 int do_read(int fd, void *buf, size_t size)
398 {
399 	void *buf_start = buf;
400 
401 	while (size) {
402 		int ret = read(fd, buf, size);
403 
404 		if (ret <= 0)
405 			return ret;
406 
407 		size -= ret;
408 		buf += ret;
409 	}
410 
411 	return buf - buf_start;
412 }
413 
414 #define session_done()	(*(volatile int *)(&session_done))
415 volatile int session_done;
416 
417 static int __perf_session__process_pipe_events(struct perf_session *self,
418 					       struct perf_event_ops *ops)
419 {
420 	event_t event;
421 	uint32_t size;
422 	int skip = 0;
423 	u64 head;
424 	int err;
425 	void *p;
426 
427 	perf_event_ops__fill_defaults(ops);
428 
429 	head = 0;
430 more:
431 	err = do_read(self->fd, &event, sizeof(struct perf_event_header));
432 	if (err <= 0) {
433 		if (err == 0)
434 			goto done;
435 
436 		pr_err("failed to read event header\n");
437 		goto out_err;
438 	}
439 
440 	if (self->header.needs_swap)
441 		perf_event_header__bswap(&event.header);
442 
443 	size = event.header.size;
444 	if (size == 0)
445 		size = 8;
446 
447 	p = &event;
448 	p += sizeof(struct perf_event_header);
449 
450 	err = do_read(self->fd, p, size - sizeof(struct perf_event_header));
451 	if (err <= 0) {
452 		if (err == 0) {
453 			pr_err("unexpected end of event stream\n");
454 			goto done;
455 		}
456 
457 		pr_err("failed to read event data\n");
458 		goto out_err;
459 	}
460 
461 	if (size == 0 ||
462 	    (skip = perf_session__process_event(self, &event, ops,
463 						0, head)) < 0) {
464 		dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
465 			    head, event.header.size, event.header.type);
466 		/*
467 		 * assume we lost track of the stream, check alignment, and
468 		 * increment a single u64 in the hope to catch on again 'soon'.
469 		 */
470 		if (unlikely(head & 7))
471 			head &= ~7ULL;
472 
473 		size = 8;
474 	}
475 
476 	head += size;
477 
478 	dump_printf("\n%#Lx [%#x]: event: %d\n",
479 		    head, event.header.size, event.header.type);
480 
481 	if (skip > 0)
482 		head += skip;
483 
484 	if (!session_done())
485 		goto more;
486 done:
487 	err = 0;
488 out_err:
489 	return err;
490 }
491 
492 int __perf_session__process_events(struct perf_session *self,
493 				   u64 data_offset, u64 data_size,
494 				   u64 file_size, struct perf_event_ops *ops)
495 {
496 	int err, mmap_prot, mmap_flags;
497 	u64 head, shift;
498 	u64 offset = 0;
499 	size_t	page_size;
500 	event_t *event;
501 	uint32_t size;
502 	char *buf;
503 	struct ui_progress *progress = ui_progress__new("Processing events...",
504 							self->size);
505 	if (progress == NULL)
506 		return -1;
507 
508 	perf_event_ops__fill_defaults(ops);
509 
510 	page_size = sysconf(_SC_PAGESIZE);
511 
512 	head = data_offset;
513 	shift = page_size * (head / page_size);
514 	offset += shift;
515 	head -= shift;
516 
517 	mmap_prot  = PROT_READ;
518 	mmap_flags = MAP_SHARED;
519 
520 	if (self->header.needs_swap) {
521 		mmap_prot  |= PROT_WRITE;
522 		mmap_flags = MAP_PRIVATE;
523 	}
524 remap:
525 	buf = mmap(NULL, page_size * self->mmap_window, mmap_prot,
526 		   mmap_flags, self->fd, offset);
527 	if (buf == MAP_FAILED) {
528 		pr_err("failed to mmap file\n");
529 		err = -errno;
530 		goto out_err;
531 	}
532 
533 more:
534 	event = (event_t *)(buf + head);
535 	ui_progress__update(progress, offset);
536 
537 	if (self->header.needs_swap)
538 		perf_event_header__bswap(&event->header);
539 	size = event->header.size;
540 	if (size == 0)
541 		size = 8;
542 
543 	if (head + event->header.size >= page_size * self->mmap_window) {
544 		int munmap_ret;
545 
546 		shift = page_size * (head / page_size);
547 
548 		munmap_ret = munmap(buf, page_size * self->mmap_window);
549 		assert(munmap_ret == 0);
550 
551 		offset += shift;
552 		head -= shift;
553 		goto remap;
554 	}
555 
556 	size = event->header.size;
557 
558 	dump_printf("\n%#Lx [%#x]: event: %d\n",
559 		    offset + head, event->header.size, event->header.type);
560 
561 	if (size == 0 ||
562 	    perf_session__process_event(self, event, ops, offset, head) < 0) {
563 		dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
564 			    offset + head, event->header.size,
565 			    event->header.type);
566 		/*
567 		 * assume we lost track of the stream, check alignment, and
568 		 * increment a single u64 in the hope to catch on again 'soon'.
569 		 */
570 		if (unlikely(head & 7))
571 			head &= ~7ULL;
572 
573 		size = 8;
574 	}
575 
576 	head += size;
577 
578 	if (offset + head >= data_offset + data_size)
579 		goto done;
580 
581 	if (offset + head < file_size)
582 		goto more;
583 done:
584 	err = 0;
585 out_err:
586 	ui_progress__delete(progress);
587 	return err;
588 }
589 
590 int perf_session__process_events(struct perf_session *self,
591 				 struct perf_event_ops *ops)
592 {
593 	int err;
594 
595 	if (perf_session__register_idle_thread(self) == NULL)
596 		return -ENOMEM;
597 
598 	if (!symbol_conf.full_paths) {
599 		char bf[PATH_MAX];
600 
601 		if (getcwd(bf, sizeof(bf)) == NULL) {
602 			err = -errno;
603 out_getcwd_err:
604 			pr_err("failed to get the current directory\n");
605 			goto out_err;
606 		}
607 		self->cwd = strdup(bf);
608 		if (self->cwd == NULL) {
609 			err = -ENOMEM;
610 			goto out_getcwd_err;
611 		}
612 		self->cwdlen = strlen(self->cwd);
613 	}
614 
615 	if (!self->fd_pipe)
616 		err = __perf_session__process_events(self,
617 						     self->header.data_offset,
618 						     self->header.data_size,
619 						     self->size, ops);
620 	else
621 		err = __perf_session__process_pipe_events(self, ops);
622 out_err:
623 	return err;
624 }
625 
626 bool perf_session__has_traces(struct perf_session *self, const char *msg)
627 {
628 	if (!(self->sample_type & PERF_SAMPLE_RAW)) {
629 		pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
630 		return false;
631 	}
632 
633 	return true;
634 }
635 
636 int perf_session__set_kallsyms_ref_reloc_sym(struct perf_session *self,
637 					     const char *symbol_name,
638 					     u64 addr)
639 {
640 	char *bracket;
641 	enum map_type i;
642 
643 	self->ref_reloc_sym.name = strdup(symbol_name);
644 	if (self->ref_reloc_sym.name == NULL)
645 		return -ENOMEM;
646 
647 	bracket = strchr(self->ref_reloc_sym.name, ']');
648 	if (bracket)
649 		*bracket = '\0';
650 
651 	self->ref_reloc_sym.addr = addr;
652 
653 	for (i = 0; i < MAP__NR_TYPES; ++i) {
654 		struct kmap *kmap = map__kmap(self->vmlinux_maps[i]);
655 		kmap->ref_reloc_sym = &self->ref_reloc_sym;
656 	}
657 
658 	return 0;
659 }
660