xref: /openbmc/linux/tools/perf/util/session.c (revision fe174207)
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 #include <sys/mman.h>
9 
10 #include "session.h"
11 #include "sort.h"
12 #include "util.h"
13 
14 static int perf_session__open(struct perf_session *self, bool force)
15 {
16 	struct stat input_stat;
17 
18 	if (!strcmp(self->filename, "-")) {
19 		self->fd_pipe = true;
20 		self->fd = STDIN_FILENO;
21 
22 		if (perf_header__read(self, self->fd) < 0)
23 			pr_err("incompatible file format");
24 
25 		return 0;
26 	}
27 
28 	self->fd = open(self->filename, O_RDONLY);
29 	if (self->fd < 0) {
30 		int err = errno;
31 
32 		pr_err("failed to open %s: %s", self->filename, strerror(err));
33 		if (err == ENOENT && !strcmp(self->filename, "perf.data"))
34 			pr_err("  (try 'perf record' first)");
35 		pr_err("\n");
36 		return -errno;
37 	}
38 
39 	if (fstat(self->fd, &input_stat) < 0)
40 		goto out_close;
41 
42 	if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
43 		pr_err("file %s not owned by current user or root\n",
44 		       self->filename);
45 		goto out_close;
46 	}
47 
48 	if (!input_stat.st_size) {
49 		pr_info("zero-sized file (%s), nothing to do!\n",
50 			self->filename);
51 		goto out_close;
52 	}
53 
54 	if (perf_header__read(self, self->fd) < 0) {
55 		pr_err("incompatible file format");
56 		goto out_close;
57 	}
58 
59 	self->size = input_stat.st_size;
60 	return 0;
61 
62 out_close:
63 	close(self->fd);
64 	self->fd = -1;
65 	return -1;
66 }
67 
68 void perf_session__update_sample_type(struct perf_session *self)
69 {
70 	self->sample_type = perf_header__sample_type(&self->header);
71 }
72 
73 int perf_session__create_kernel_maps(struct perf_session *self)
74 {
75 	int ret = machine__create_kernel_maps(&self->host_machine);
76 
77 	if (ret >= 0)
78 		ret = machines__create_guest_kernel_maps(&self->machines);
79 	return ret;
80 }
81 
82 static void perf_session__destroy_kernel_maps(struct perf_session *self)
83 {
84 	machine__destroy_kernel_maps(&self->host_machine);
85 	machines__destroy_guest_kernel_maps(&self->machines);
86 }
87 
88 struct perf_session *perf_session__new(const char *filename, int mode, bool force, bool repipe)
89 {
90 	size_t len = filename ? strlen(filename) + 1 : 0;
91 	struct perf_session *self = zalloc(sizeof(*self) + len);
92 
93 	if (self == NULL)
94 		goto out;
95 
96 	if (perf_header__init(&self->header) < 0)
97 		goto out_free;
98 
99 	memcpy(self->filename, filename, len);
100 	self->threads = RB_ROOT;
101 	INIT_LIST_HEAD(&self->dead_threads);
102 	self->hists_tree = RB_ROOT;
103 	self->last_match = NULL;
104 	/*
105 	 * On 64bit we can mmap the data file in one go. No need for tiny mmap
106 	 * slices. On 32bit we use 32MB.
107 	 */
108 #if BITS_PER_LONG == 64
109 	self->mmap_window = ULLONG_MAX;
110 #else
111 	self->mmap_window = 32 * 1024 * 1024ULL;
112 #endif
113 	self->machines = RB_ROOT;
114 	self->repipe = repipe;
115 	INIT_LIST_HEAD(&self->ordered_samples.samples);
116 	machine__init(&self->host_machine, "", HOST_KERNEL_ID);
117 
118 	if (mode == O_RDONLY) {
119 		if (perf_session__open(self, force) < 0)
120 			goto out_delete;
121 	} else if (mode == O_WRONLY) {
122 		/*
123 		 * In O_RDONLY mode this will be performed when reading the
124 		 * kernel MMAP event, in event__process_mmap().
125 		 */
126 		if (perf_session__create_kernel_maps(self) < 0)
127 			goto out_delete;
128 	}
129 
130 	perf_session__update_sample_type(self);
131 out:
132 	return self;
133 out_free:
134 	free(self);
135 	return NULL;
136 out_delete:
137 	perf_session__delete(self);
138 	return NULL;
139 }
140 
141 static void perf_session__delete_dead_threads(struct perf_session *self)
142 {
143 	struct thread *n, *t;
144 
145 	list_for_each_entry_safe(t, n, &self->dead_threads, node) {
146 		list_del(&t->node);
147 		thread__delete(t);
148 	}
149 }
150 
151 static void perf_session__delete_threads(struct perf_session *self)
152 {
153 	struct rb_node *nd = rb_first(&self->threads);
154 
155 	while (nd) {
156 		struct thread *t = rb_entry(nd, struct thread, rb_node);
157 
158 		rb_erase(&t->rb_node, &self->threads);
159 		nd = rb_next(nd);
160 		thread__delete(t);
161 	}
162 }
163 
164 void perf_session__delete(struct perf_session *self)
165 {
166 	perf_header__exit(&self->header);
167 	perf_session__destroy_kernel_maps(self);
168 	perf_session__delete_dead_threads(self);
169 	perf_session__delete_threads(self);
170 	machine__exit(&self->host_machine);
171 	close(self->fd);
172 	free(self);
173 }
174 
175 void perf_session__remove_thread(struct perf_session *self, struct thread *th)
176 {
177 	self->last_match = NULL;
178 	rb_erase(&th->rb_node, &self->threads);
179 	/*
180 	 * We may have references to this thread, for instance in some hist_entry
181 	 * instances, so just move them to a separate list.
182 	 */
183 	list_add_tail(&th->node, &self->dead_threads);
184 }
185 
186 static bool symbol__match_parent_regex(struct symbol *sym)
187 {
188 	if (sym->name && !regexec(&parent_regex, sym->name, 0, NULL, 0))
189 		return 1;
190 
191 	return 0;
192 }
193 
194 struct map_symbol *perf_session__resolve_callchain(struct perf_session *self,
195 						   struct thread *thread,
196 						   struct ip_callchain *chain,
197 						   struct symbol **parent)
198 {
199 	u8 cpumode = PERF_RECORD_MISC_USER;
200 	unsigned int i;
201 	struct map_symbol *syms = calloc(chain->nr, sizeof(*syms));
202 
203 	if (!syms)
204 		return NULL;
205 
206 	for (i = 0; i < chain->nr; i++) {
207 		u64 ip = chain->ips[i];
208 		struct addr_location al;
209 
210 		if (ip >= PERF_CONTEXT_MAX) {
211 			switch (ip) {
212 			case PERF_CONTEXT_HV:
213 				cpumode = PERF_RECORD_MISC_HYPERVISOR;	break;
214 			case PERF_CONTEXT_KERNEL:
215 				cpumode = PERF_RECORD_MISC_KERNEL;	break;
216 			case PERF_CONTEXT_USER:
217 				cpumode = PERF_RECORD_MISC_USER;	break;
218 			default:
219 				break;
220 			}
221 			continue;
222 		}
223 
224 		al.filtered = false;
225 		thread__find_addr_location(thread, self, cpumode,
226 				MAP__FUNCTION, thread->pid, ip, &al, NULL);
227 		if (al.sym != NULL) {
228 			if (sort__has_parent && !*parent &&
229 			    symbol__match_parent_regex(al.sym))
230 				*parent = al.sym;
231 			if (!symbol_conf.use_callchain)
232 				break;
233 			syms[i].map = al.map;
234 			syms[i].sym = al.sym;
235 		}
236 	}
237 
238 	return syms;
239 }
240 
241 static int process_event_stub(event_t *event __used,
242 			      struct perf_session *session __used)
243 {
244 	dump_printf(": unhandled!\n");
245 	return 0;
246 }
247 
248 static int process_finished_round_stub(event_t *event __used,
249 				       struct perf_session *session __used,
250 				       struct perf_event_ops *ops __used)
251 {
252 	dump_printf(": unhandled!\n");
253 	return 0;
254 }
255 
256 static int process_finished_round(event_t *event,
257 				  struct perf_session *session,
258 				  struct perf_event_ops *ops);
259 
260 static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
261 {
262 	if (handler->sample == NULL)
263 		handler->sample = process_event_stub;
264 	if (handler->mmap == NULL)
265 		handler->mmap = process_event_stub;
266 	if (handler->comm == NULL)
267 		handler->comm = process_event_stub;
268 	if (handler->fork == NULL)
269 		handler->fork = process_event_stub;
270 	if (handler->exit == NULL)
271 		handler->exit = process_event_stub;
272 	if (handler->lost == NULL)
273 		handler->lost = event__process_lost;
274 	if (handler->read == NULL)
275 		handler->read = process_event_stub;
276 	if (handler->throttle == NULL)
277 		handler->throttle = process_event_stub;
278 	if (handler->unthrottle == NULL)
279 		handler->unthrottle = process_event_stub;
280 	if (handler->attr == NULL)
281 		handler->attr = process_event_stub;
282 	if (handler->event_type == NULL)
283 		handler->event_type = process_event_stub;
284 	if (handler->tracing_data == NULL)
285 		handler->tracing_data = process_event_stub;
286 	if (handler->build_id == NULL)
287 		handler->build_id = process_event_stub;
288 	if (handler->finished_round == NULL) {
289 		if (handler->ordered_samples)
290 			handler->finished_round = process_finished_round;
291 		else
292 			handler->finished_round = process_finished_round_stub;
293 	}
294 }
295 
296 void mem_bswap_64(void *src, int byte_size)
297 {
298 	u64 *m = src;
299 
300 	while (byte_size > 0) {
301 		*m = bswap_64(*m);
302 		byte_size -= sizeof(u64);
303 		++m;
304 	}
305 }
306 
307 static void event__all64_swap(event_t *self)
308 {
309 	struct perf_event_header *hdr = &self->header;
310 	mem_bswap_64(hdr + 1, self->header.size - sizeof(*hdr));
311 }
312 
313 static void event__comm_swap(event_t *self)
314 {
315 	self->comm.pid = bswap_32(self->comm.pid);
316 	self->comm.tid = bswap_32(self->comm.tid);
317 }
318 
319 static void event__mmap_swap(event_t *self)
320 {
321 	self->mmap.pid	 = bswap_32(self->mmap.pid);
322 	self->mmap.tid	 = bswap_32(self->mmap.tid);
323 	self->mmap.start = bswap_64(self->mmap.start);
324 	self->mmap.len	 = bswap_64(self->mmap.len);
325 	self->mmap.pgoff = bswap_64(self->mmap.pgoff);
326 }
327 
328 static void event__task_swap(event_t *self)
329 {
330 	self->fork.pid	= bswap_32(self->fork.pid);
331 	self->fork.tid	= bswap_32(self->fork.tid);
332 	self->fork.ppid	= bswap_32(self->fork.ppid);
333 	self->fork.ptid	= bswap_32(self->fork.ptid);
334 	self->fork.time	= bswap_64(self->fork.time);
335 }
336 
337 static void event__read_swap(event_t *self)
338 {
339 	self->read.pid		= bswap_32(self->read.pid);
340 	self->read.tid		= bswap_32(self->read.tid);
341 	self->read.value	= bswap_64(self->read.value);
342 	self->read.time_enabled	= bswap_64(self->read.time_enabled);
343 	self->read.time_running	= bswap_64(self->read.time_running);
344 	self->read.id		= bswap_64(self->read.id);
345 }
346 
347 static void event__attr_swap(event_t *self)
348 {
349 	size_t size;
350 
351 	self->attr.attr.type		= bswap_32(self->attr.attr.type);
352 	self->attr.attr.size		= bswap_32(self->attr.attr.size);
353 	self->attr.attr.config		= bswap_64(self->attr.attr.config);
354 	self->attr.attr.sample_period	= bswap_64(self->attr.attr.sample_period);
355 	self->attr.attr.sample_type	= bswap_64(self->attr.attr.sample_type);
356 	self->attr.attr.read_format	= bswap_64(self->attr.attr.read_format);
357 	self->attr.attr.wakeup_events	= bswap_32(self->attr.attr.wakeup_events);
358 	self->attr.attr.bp_type		= bswap_32(self->attr.attr.bp_type);
359 	self->attr.attr.bp_addr		= bswap_64(self->attr.attr.bp_addr);
360 	self->attr.attr.bp_len		= bswap_64(self->attr.attr.bp_len);
361 
362 	size = self->header.size;
363 	size -= (void *)&self->attr.id - (void *)self;
364 	mem_bswap_64(self->attr.id, size);
365 }
366 
367 static void event__event_type_swap(event_t *self)
368 {
369 	self->event_type.event_type.event_id =
370 		bswap_64(self->event_type.event_type.event_id);
371 }
372 
373 static void event__tracing_data_swap(event_t *self)
374 {
375 	self->tracing_data.size = bswap_32(self->tracing_data.size);
376 }
377 
378 typedef void (*event__swap_op)(event_t *self);
379 
380 static event__swap_op event__swap_ops[] = {
381 	[PERF_RECORD_MMAP]   = event__mmap_swap,
382 	[PERF_RECORD_COMM]   = event__comm_swap,
383 	[PERF_RECORD_FORK]   = event__task_swap,
384 	[PERF_RECORD_EXIT]   = event__task_swap,
385 	[PERF_RECORD_LOST]   = event__all64_swap,
386 	[PERF_RECORD_READ]   = event__read_swap,
387 	[PERF_RECORD_SAMPLE] = event__all64_swap,
388 	[PERF_RECORD_HEADER_ATTR]   = event__attr_swap,
389 	[PERF_RECORD_HEADER_EVENT_TYPE]   = event__event_type_swap,
390 	[PERF_RECORD_HEADER_TRACING_DATA]   = event__tracing_data_swap,
391 	[PERF_RECORD_HEADER_BUILD_ID]   = NULL,
392 	[PERF_RECORD_HEADER_MAX]    = NULL,
393 };
394 
395 struct sample_queue {
396 	u64			timestamp;
397 	event_t			*event;
398 	struct list_head	list;
399 };
400 
401 static void flush_sample_queue(struct perf_session *s,
402 			       struct perf_event_ops *ops)
403 {
404 	struct ordered_samples *os = &s->ordered_samples;
405 	struct list_head *head = &os->samples;
406 	struct sample_queue *tmp, *iter;
407 	u64 limit = os->next_flush;
408 	u64 last_ts = os->last_sample ? os->last_sample->timestamp : 0ULL;
409 
410 	if (!ops->ordered_samples || !limit)
411 		return;
412 
413 	list_for_each_entry_safe(iter, tmp, head, list) {
414 		if (iter->timestamp > limit)
415 			break;
416 
417 		ops->sample(iter->event, s);
418 
419 		os->last_flush = iter->timestamp;
420 		list_del(&iter->list);
421 		free(iter);
422 	}
423 
424 	if (list_empty(head)) {
425 		os->last_sample = NULL;
426 	} else if (last_ts <= limit) {
427 		os->last_sample =
428 			list_entry(head->prev, struct sample_queue, list);
429 	}
430 }
431 
432 /*
433  * When perf record finishes a pass on every buffers, it records this pseudo
434  * event.
435  * We record the max timestamp t found in the pass n.
436  * Assuming these timestamps are monotonic across cpus, we know that if
437  * a buffer still has events with timestamps below t, they will be all
438  * available and then read in the pass n + 1.
439  * Hence when we start to read the pass n + 2, we can safely flush every
440  * events with timestamps below t.
441  *
442  *    ============ PASS n =================
443  *       CPU 0         |   CPU 1
444  *                     |
445  *    cnt1 timestamps  |   cnt2 timestamps
446  *          1          |         2
447  *          2          |         3
448  *          -          |         4  <--- max recorded
449  *
450  *    ============ PASS n + 1 ==============
451  *       CPU 0         |   CPU 1
452  *                     |
453  *    cnt1 timestamps  |   cnt2 timestamps
454  *          3          |         5
455  *          4          |         6
456  *          5          |         7 <---- max recorded
457  *
458  *      Flush every events below timestamp 4
459  *
460  *    ============ PASS n + 2 ==============
461  *       CPU 0         |   CPU 1
462  *                     |
463  *    cnt1 timestamps  |   cnt2 timestamps
464  *          6          |         8
465  *          7          |         9
466  *          -          |         10
467  *
468  *      Flush every events below timestamp 7
469  *      etc...
470  */
471 static int process_finished_round(event_t *event __used,
472 				  struct perf_session *session,
473 				  struct perf_event_ops *ops)
474 {
475 	flush_sample_queue(session, ops);
476 	session->ordered_samples.next_flush = session->ordered_samples.max_timestamp;
477 
478 	return 0;
479 }
480 
481 /* The queue is ordered by time */
482 static void __queue_sample_event(struct sample_queue *new,
483 				 struct perf_session *s)
484 {
485 	struct ordered_samples *os = &s->ordered_samples;
486 	struct sample_queue *sample = os->last_sample;
487 	u64 timestamp = new->timestamp;
488 	struct list_head *p;
489 
490 	os->last_sample = new;
491 
492 	if (!sample) {
493 		list_add(&new->list, &os->samples);
494 		os->max_timestamp = timestamp;
495 		return;
496 	}
497 
498 	/*
499 	 * last_sample might point to some random place in the list as it's
500 	 * the last queued event. We expect that the new event is close to
501 	 * this.
502 	 */
503 	if (sample->timestamp <= timestamp) {
504 		while (sample->timestamp <= timestamp) {
505 			p = sample->list.next;
506 			if (p == &os->samples) {
507 				list_add_tail(&new->list, &os->samples);
508 				os->max_timestamp = timestamp;
509 				return;
510 			}
511 			sample = list_entry(p, struct sample_queue, list);
512 		}
513 		list_add_tail(&new->list, &sample->list);
514 	} else {
515 		while (sample->timestamp > timestamp) {
516 			p = sample->list.prev;
517 			if (p == &os->samples) {
518 				list_add(&new->list, &os->samples);
519 				return;
520 			}
521 			sample = list_entry(p, struct sample_queue, list);
522 		}
523 		list_add(&new->list, &sample->list);
524 	}
525 }
526 
527 static int queue_sample_event(event_t *event, struct sample_data *data,
528 			      struct perf_session *s)
529 {
530 	u64 timestamp = data->time;
531 	struct sample_queue *new;
532 
533 	if (timestamp < s->ordered_samples.last_flush) {
534 		printf("Warning: Timestamp below last timeslice flush\n");
535 		return -EINVAL;
536 	}
537 
538 	new = malloc(sizeof(*new));
539 	if (!new)
540 		return -ENOMEM;
541 
542 	new->timestamp = timestamp;
543 	new->event = event;
544 
545 	__queue_sample_event(new, s);
546 
547 	return 0;
548 }
549 
550 static int perf_session__process_sample(event_t *event, struct perf_session *s,
551 					struct perf_event_ops *ops)
552 {
553 	struct sample_data data;
554 
555 	if (!ops->ordered_samples)
556 		return ops->sample(event, s);
557 
558 	bzero(&data, sizeof(struct sample_data));
559 	event__parse_sample(event, s->sample_type, &data);
560 
561 	queue_sample_event(event, &data, s);
562 
563 	return 0;
564 }
565 
566 static int perf_session__process_event(struct perf_session *self,
567 				       event_t *event,
568 				       struct perf_event_ops *ops,
569 				       u64 file_offset)
570 {
571 	trace_event(event);
572 
573 	if (event->header.type < PERF_RECORD_HEADER_MAX) {
574 		dump_printf("%#Lx [%#x]: PERF_RECORD_%s",
575 			    file_offset, event->header.size,
576 			    event__name[event->header.type]);
577 		hists__inc_nr_events(&self->hists, event->header.type);
578 	}
579 
580 	if (self->header.needs_swap && event__swap_ops[event->header.type])
581 		event__swap_ops[event->header.type](event);
582 
583 	switch (event->header.type) {
584 	case PERF_RECORD_SAMPLE:
585 		return perf_session__process_sample(event, self, ops);
586 	case PERF_RECORD_MMAP:
587 		return ops->mmap(event, self);
588 	case PERF_RECORD_COMM:
589 		return ops->comm(event, self);
590 	case PERF_RECORD_FORK:
591 		return ops->fork(event, self);
592 	case PERF_RECORD_EXIT:
593 		return ops->exit(event, self);
594 	case PERF_RECORD_LOST:
595 		return ops->lost(event, self);
596 	case PERF_RECORD_READ:
597 		return ops->read(event, self);
598 	case PERF_RECORD_THROTTLE:
599 		return ops->throttle(event, self);
600 	case PERF_RECORD_UNTHROTTLE:
601 		return ops->unthrottle(event, self);
602 	case PERF_RECORD_HEADER_ATTR:
603 		return ops->attr(event, self);
604 	case PERF_RECORD_HEADER_EVENT_TYPE:
605 		return ops->event_type(event, self);
606 	case PERF_RECORD_HEADER_TRACING_DATA:
607 		/* setup for reading amidst mmap */
608 		lseek(self->fd, file_offset, SEEK_SET);
609 		return ops->tracing_data(event, self);
610 	case PERF_RECORD_HEADER_BUILD_ID:
611 		return ops->build_id(event, self);
612 	case PERF_RECORD_FINISHED_ROUND:
613 		return ops->finished_round(event, self, ops);
614 	default:
615 		++self->hists.stats.nr_unknown_events;
616 		return -1;
617 	}
618 }
619 
620 void perf_event_header__bswap(struct perf_event_header *self)
621 {
622 	self->type = bswap_32(self->type);
623 	self->misc = bswap_16(self->misc);
624 	self->size = bswap_16(self->size);
625 }
626 
627 static struct thread *perf_session__register_idle_thread(struct perf_session *self)
628 {
629 	struct thread *thread = perf_session__findnew(self, 0);
630 
631 	if (thread == NULL || thread__set_comm(thread, "swapper")) {
632 		pr_err("problem inserting idle task.\n");
633 		thread = NULL;
634 	}
635 
636 	return thread;
637 }
638 
639 int do_read(int fd, void *buf, size_t size)
640 {
641 	void *buf_start = buf;
642 
643 	while (size) {
644 		int ret = read(fd, buf, size);
645 
646 		if (ret <= 0)
647 			return ret;
648 
649 		size -= ret;
650 		buf += ret;
651 	}
652 
653 	return buf - buf_start;
654 }
655 
656 #define session_done()	(*(volatile int *)(&session_done))
657 volatile int session_done;
658 
659 static int __perf_session__process_pipe_events(struct perf_session *self,
660 					       struct perf_event_ops *ops)
661 {
662 	event_t event;
663 	uint32_t size;
664 	int skip = 0;
665 	u64 head;
666 	int err;
667 	void *p;
668 
669 	perf_event_ops__fill_defaults(ops);
670 
671 	head = 0;
672 more:
673 	err = do_read(self->fd, &event, sizeof(struct perf_event_header));
674 	if (err <= 0) {
675 		if (err == 0)
676 			goto done;
677 
678 		pr_err("failed to read event header\n");
679 		goto out_err;
680 	}
681 
682 	if (self->header.needs_swap)
683 		perf_event_header__bswap(&event.header);
684 
685 	size = event.header.size;
686 	if (size == 0)
687 		size = 8;
688 
689 	p = &event;
690 	p += sizeof(struct perf_event_header);
691 
692 	if (size - sizeof(struct perf_event_header)) {
693 		err = do_read(self->fd, p,
694 			      size - sizeof(struct perf_event_header));
695 		if (err <= 0) {
696 			if (err == 0) {
697 				pr_err("unexpected end of event stream\n");
698 				goto done;
699 			}
700 
701 			pr_err("failed to read event data\n");
702 			goto out_err;
703 		}
704 	}
705 
706 	if (size == 0 ||
707 	    (skip = perf_session__process_event(self, &event, ops, head)) < 0) {
708 		dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
709 			    head, event.header.size, event.header.type);
710 		/*
711 		 * assume we lost track of the stream, check alignment, and
712 		 * increment a single u64 in the hope to catch on again 'soon'.
713 		 */
714 		if (unlikely(head & 7))
715 			head &= ~7ULL;
716 
717 		size = 8;
718 	}
719 
720 	head += size;
721 
722 	dump_printf("\n%#Lx [%#x]: event: %d\n",
723 		    head, event.header.size, event.header.type);
724 
725 	if (skip > 0)
726 		head += skip;
727 
728 	if (!session_done())
729 		goto more;
730 done:
731 	err = 0;
732 out_err:
733 	return err;
734 }
735 
736 int __perf_session__process_events(struct perf_session *session,
737 				   u64 data_offset, u64 data_size,
738 				   u64 file_size, struct perf_event_ops *ops)
739 {
740 	u64 head, page_offset, file_offset, file_pos, progress_next;
741 	int err, mmap_prot, mmap_flags, map_idx = 0;
742 	struct ui_progress *progress;
743 	size_t	page_size, mmap_size;
744 	char *buf, *mmaps[8];
745 	event_t *event;
746 	uint32_t size;
747 
748 	perf_event_ops__fill_defaults(ops);
749 
750 	page_size = sysconf(_SC_PAGESIZE);
751 
752 	page_offset = page_size * (data_offset / page_size);
753 	file_offset = page_offset;
754 	head = data_offset - page_offset;
755 
756 	if (data_offset + data_size < file_size)
757 		file_size = data_offset + data_size;
758 
759 	progress_next = file_size / 16;
760 	progress = ui_progress__new("Processing events...", file_size);
761 	if (progress == NULL)
762 		return -1;
763 
764 	mmap_size = session->mmap_window;
765 	if (mmap_size > file_size)
766 		mmap_size = file_size;
767 
768 	memset(mmaps, 0, sizeof(mmaps));
769 
770 	mmap_prot  = PROT_READ;
771 	mmap_flags = MAP_SHARED;
772 
773 	if (session->header.needs_swap) {
774 		mmap_prot  |= PROT_WRITE;
775 		mmap_flags = MAP_PRIVATE;
776 	}
777 remap:
778 	buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, session->fd,
779 		   file_offset);
780 	if (buf == MAP_FAILED) {
781 		pr_err("failed to mmap file\n");
782 		err = -errno;
783 		goto out_err;
784 	}
785 	mmaps[map_idx] = buf;
786 	map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
787 	file_pos = file_offset + head;
788 
789 more:
790 	event = (event_t *)(buf + head);
791 
792 	if (session->header.needs_swap)
793 		perf_event_header__bswap(&event->header);
794 	size = event->header.size;
795 	if (size == 0)
796 		size = 8;
797 
798 	if (head + event->header.size >= mmap_size) {
799 		if (mmaps[map_idx]) {
800 			munmap(mmaps[map_idx], mmap_size);
801 			mmaps[map_idx] = NULL;
802 		}
803 
804 		page_offset = page_size * (head / page_size);
805 		file_offset += page_offset;
806 		head -= page_offset;
807 		goto remap;
808 	}
809 
810 	size = event->header.size;
811 
812 	dump_printf("\n%#Lx [%#x]: event: %d\n",
813 		    file_pos, event->header.size, event->header.type);
814 
815 	if (size == 0 ||
816 	    perf_session__process_event(session, event, ops, file_pos) < 0) {
817 		dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
818 			    file_offset + head, event->header.size,
819 			    event->header.type);
820 		/*
821 		 * assume we lost track of the stream, check alignment, and
822 		 * increment a single u64 in the hope to catch on again 'soon'.
823 		 */
824 		if (unlikely(head & 7))
825 			head &= ~7ULL;
826 
827 		size = 8;
828 	}
829 
830 	head += size;
831 	file_pos += size;
832 
833 	if (file_pos >= progress_next) {
834 		progress_next += file_size / 16;
835 		ui_progress__update(progress, file_pos);
836 	}
837 
838 	if (file_pos < file_size)
839 		goto more;
840 
841 	err = 0;
842 	/* do the final flush for ordered samples */
843 	session->ordered_samples.next_flush = ULLONG_MAX;
844 	flush_sample_queue(session, ops);
845 out_err:
846 	ui_progress__delete(progress);
847 
848 	if (ops->lost == event__process_lost &&
849 	    session->hists.stats.total_lost != 0) {
850 		ui__warning("Processed %Lu events and LOST %Lu!\n\n"
851 			    "Check IO/CPU overload!\n\n",
852 			    session->hists.stats.total_period,
853 			    session->hists.stats.total_lost);
854 	}
855 
856 	if (session->hists.stats.nr_unknown_events != 0) {
857 		ui__warning("Found %u unknown events!\n\n"
858 			    "Is this an older tool processing a perf.data "
859 			    "file generated by a more recent tool?\n\n"
860 			    "If that is not the case, consider "
861 			    "reporting to linux-kernel@vger.kernel.org.\n\n",
862 			    session->hists.stats.nr_unknown_events);
863 	}
864 
865 	return err;
866 }
867 
868 int perf_session__process_events(struct perf_session *self,
869 				 struct perf_event_ops *ops)
870 {
871 	int err;
872 
873 	if (perf_session__register_idle_thread(self) == NULL)
874 		return -ENOMEM;
875 
876 	if (!self->fd_pipe)
877 		err = __perf_session__process_events(self,
878 						     self->header.data_offset,
879 						     self->header.data_size,
880 						     self->size, ops);
881 	else
882 		err = __perf_session__process_pipe_events(self, ops);
883 
884 	return err;
885 }
886 
887 bool perf_session__has_traces(struct perf_session *self, const char *msg)
888 {
889 	if (!(self->sample_type & PERF_SAMPLE_RAW)) {
890 		pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
891 		return false;
892 	}
893 
894 	return true;
895 }
896 
897 int perf_session__set_kallsyms_ref_reloc_sym(struct map **maps,
898 					     const char *symbol_name,
899 					     u64 addr)
900 {
901 	char *bracket;
902 	enum map_type i;
903 	struct ref_reloc_sym *ref;
904 
905 	ref = zalloc(sizeof(struct ref_reloc_sym));
906 	if (ref == NULL)
907 		return -ENOMEM;
908 
909 	ref->name = strdup(symbol_name);
910 	if (ref->name == NULL) {
911 		free(ref);
912 		return -ENOMEM;
913 	}
914 
915 	bracket = strchr(ref->name, ']');
916 	if (bracket)
917 		*bracket = '\0';
918 
919 	ref->addr = addr;
920 
921 	for (i = 0; i < MAP__NR_TYPES; ++i) {
922 		struct kmap *kmap = map__kmap(maps[i]);
923 		kmap->ref_reloc_sym = ref;
924 	}
925 
926 	return 0;
927 }
928 
929 size_t perf_session__fprintf_dsos(struct perf_session *self, FILE *fp)
930 {
931 	return __dsos__fprintf(&self->host_machine.kernel_dsos, fp) +
932 	       __dsos__fprintf(&self->host_machine.user_dsos, fp) +
933 	       machines__fprintf_dsos(&self->machines, fp);
934 }
935 
936 size_t perf_session__fprintf_dsos_buildid(struct perf_session *self, FILE *fp,
937 					  bool with_hits)
938 {
939 	size_t ret = machine__fprintf_dsos_buildid(&self->host_machine, fp, with_hits);
940 	return ret + machines__fprintf_dsos_buildid(&self->machines, fp, with_hits);
941 }
942