xref: /openbmc/linux/tools/perf/util/event.c (revision 79f08d9e)
1 #include <linux/types.h>
2 #include "event.h"
3 #include "debug.h"
4 #include "machine.h"
5 #include "sort.h"
6 #include "string.h"
7 #include "strlist.h"
8 #include "thread.h"
9 #include "thread_map.h"
10 
11 static const char *perf_event__names[] = {
12 	[0]					= "TOTAL",
13 	[PERF_RECORD_MMAP]			= "MMAP",
14 	[PERF_RECORD_MMAP2]			= "MMAP2",
15 	[PERF_RECORD_LOST]			= "LOST",
16 	[PERF_RECORD_COMM]			= "COMM",
17 	[PERF_RECORD_EXIT]			= "EXIT",
18 	[PERF_RECORD_THROTTLE]			= "THROTTLE",
19 	[PERF_RECORD_UNTHROTTLE]		= "UNTHROTTLE",
20 	[PERF_RECORD_FORK]			= "FORK",
21 	[PERF_RECORD_READ]			= "READ",
22 	[PERF_RECORD_SAMPLE]			= "SAMPLE",
23 	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
24 	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
25 	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
26 	[PERF_RECORD_HEADER_BUILD_ID]		= "BUILD_ID",
27 	[PERF_RECORD_FINISHED_ROUND]		= "FINISHED_ROUND",
28 };
29 
30 const char *perf_event__name(unsigned int id)
31 {
32 	if (id >= ARRAY_SIZE(perf_event__names))
33 		return "INVALID";
34 	if (!perf_event__names[id])
35 		return "UNKNOWN";
36 	return perf_event__names[id];
37 }
38 
39 static struct perf_sample synth_sample = {
40 	.pid	   = -1,
41 	.tid	   = -1,
42 	.time	   = -1,
43 	.stream_id = -1,
44 	.cpu	   = -1,
45 	.period	   = 1,
46 };
47 
48 static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
49 {
50 	char filename[PATH_MAX];
51 	char bf[BUFSIZ];
52 	FILE *fp;
53 	size_t size = 0;
54 	pid_t tgid = -1;
55 
56 	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
57 
58 	fp = fopen(filename, "r");
59 	if (fp == NULL) {
60 		pr_debug("couldn't open %s\n", filename);
61 		return 0;
62 	}
63 
64 	while (!comm[0] || (tgid < 0)) {
65 		if (fgets(bf, sizeof(bf), fp) == NULL) {
66 			pr_warning("couldn't get COMM and pgid, malformed %s\n",
67 				   filename);
68 			break;
69 		}
70 
71 		if (memcmp(bf, "Name:", 5) == 0) {
72 			char *name = bf + 5;
73 			while (*name && isspace(*name))
74 				++name;
75 			size = strlen(name) - 1;
76 			if (size >= len)
77 				size = len - 1;
78 			memcpy(comm, name, size);
79 			comm[size] = '\0';
80 
81 		} else if (memcmp(bf, "Tgid:", 5) == 0) {
82 			char *tgids = bf + 5;
83 			while (*tgids && isspace(*tgids))
84 				++tgids;
85 			tgid = atoi(tgids);
86 		}
87 	}
88 
89 	fclose(fp);
90 
91 	return tgid;
92 }
93 
94 static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
95 					 union perf_event *event, pid_t pid,
96 					 int full,
97 					 perf_event__handler_t process,
98 					 struct machine *machine)
99 {
100 	char filename[PATH_MAX];
101 	size_t size;
102 	DIR *tasks;
103 	struct dirent dirent, *next;
104 	pid_t tgid;
105 
106 	memset(&event->comm, 0, sizeof(event->comm));
107 
108 	tgid = perf_event__get_comm_tgid(pid, event->comm.comm,
109 					 sizeof(event->comm.comm));
110 	if (tgid < 0)
111 		goto out;
112 
113 	event->comm.pid = tgid;
114 	event->comm.header.type = PERF_RECORD_COMM;
115 
116 	size = strlen(event->comm.comm) + 1;
117 	size = PERF_ALIGN(size, sizeof(u64));
118 	memset(event->comm.comm + size, 0, machine->id_hdr_size);
119 	event->comm.header.size = (sizeof(event->comm) -
120 				(sizeof(event->comm.comm) - size) +
121 				machine->id_hdr_size);
122 	if (!full) {
123 		event->comm.tid = pid;
124 
125 		if (process(tool, event, &synth_sample, machine) != 0)
126 			return -1;
127 
128 		goto out;
129 	}
130 
131 	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
132 
133 	tasks = opendir(filename);
134 	if (tasks == NULL) {
135 		pr_debug("couldn't open %s\n", filename);
136 		return 0;
137 	}
138 
139 	while (!readdir_r(tasks, &dirent, &next) && next) {
140 		char *end;
141 		pid = strtol(dirent.d_name, &end, 10);
142 		if (*end)
143 			continue;
144 
145 		/* already have tgid; jut want to update the comm */
146 		(void) perf_event__get_comm_tgid(pid, event->comm.comm,
147 					 sizeof(event->comm.comm));
148 
149 		size = strlen(event->comm.comm) + 1;
150 		size = PERF_ALIGN(size, sizeof(u64));
151 		memset(event->comm.comm + size, 0, machine->id_hdr_size);
152 		event->comm.header.size = (sizeof(event->comm) -
153 					  (sizeof(event->comm.comm) - size) +
154 					  machine->id_hdr_size);
155 
156 		event->comm.tid = pid;
157 
158 		if (process(tool, event, &synth_sample, machine) != 0) {
159 			tgid = -1;
160 			break;
161 		}
162 	}
163 
164 	closedir(tasks);
165 out:
166 	return tgid;
167 }
168 
169 static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
170 					      union perf_event *event,
171 					      pid_t pid, pid_t tgid,
172 					      perf_event__handler_t process,
173 					      struct machine *machine,
174 					      bool mmap_data)
175 {
176 	char filename[PATH_MAX];
177 	FILE *fp;
178 	int rc = 0;
179 
180 	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
181 
182 	fp = fopen(filename, "r");
183 	if (fp == NULL) {
184 		/*
185 		 * We raced with a task exiting - just return:
186 		 */
187 		pr_debug("couldn't open %s\n", filename);
188 		return -1;
189 	}
190 
191 	event->header.type = PERF_RECORD_MMAP;
192 
193 	while (1) {
194 		char bf[BUFSIZ];
195 		char prot[5];
196 		char execname[PATH_MAX];
197 		char anonstr[] = "//anon";
198 		size_t size;
199 		ssize_t n;
200 
201 		if (fgets(bf, sizeof(bf), fp) == NULL)
202 			break;
203 
204 		/* ensure null termination since stack will be reused. */
205 		strcpy(execname, "");
206 
207 		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
208 		n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
209 		       &event->mmap.start, &event->mmap.len, prot,
210 		       &event->mmap.pgoff,
211 		       execname);
212 		/*
213  		 * Anon maps don't have the execname.
214  		 */
215 		if (n < 4)
216 			continue;
217 		/*
218 		 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
219 		 */
220 		event->header.misc = PERF_RECORD_MISC_USER;
221 
222 		if (prot[2] != 'x') {
223 			if (!mmap_data || prot[0] != 'r')
224 				continue;
225 
226 			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
227 		}
228 
229 		if (!strcmp(execname, ""))
230 			strcpy(execname, anonstr);
231 
232 		size = strlen(execname) + 1;
233 		memcpy(event->mmap.filename, execname, size);
234 		size = PERF_ALIGN(size, sizeof(u64));
235 		event->mmap.len -= event->mmap.start;
236 		event->mmap.header.size = (sizeof(event->mmap) -
237 					(sizeof(event->mmap.filename) - size));
238 		memset(event->mmap.filename + size, 0, machine->id_hdr_size);
239 		event->mmap.header.size += machine->id_hdr_size;
240 		event->mmap.pid = tgid;
241 		event->mmap.tid = pid;
242 
243 		if (process(tool, event, &synth_sample, machine) != 0) {
244 			rc = -1;
245 			break;
246 		}
247 	}
248 
249 	fclose(fp);
250 	return rc;
251 }
252 
253 int perf_event__synthesize_modules(struct perf_tool *tool,
254 				   perf_event__handler_t process,
255 				   struct machine *machine)
256 {
257 	int rc = 0;
258 	struct rb_node *nd;
259 	struct map_groups *kmaps = &machine->kmaps;
260 	union perf_event *event = zalloc((sizeof(event->mmap) +
261 					  machine->id_hdr_size));
262 	if (event == NULL) {
263 		pr_debug("Not enough memory synthesizing mmap event "
264 			 "for kernel modules\n");
265 		return -1;
266 	}
267 
268 	event->header.type = PERF_RECORD_MMAP;
269 
270 	/*
271 	 * kernel uses 0 for user space maps, see kernel/perf_event.c
272 	 * __perf_event_mmap
273 	 */
274 	if (machine__is_host(machine))
275 		event->header.misc = PERF_RECORD_MISC_KERNEL;
276 	else
277 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
278 
279 	for (nd = rb_first(&kmaps->maps[MAP__FUNCTION]);
280 	     nd; nd = rb_next(nd)) {
281 		size_t size;
282 		struct map *pos = rb_entry(nd, struct map, rb_node);
283 
284 		if (pos->dso->kernel)
285 			continue;
286 
287 		size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
288 		event->mmap.header.type = PERF_RECORD_MMAP;
289 		event->mmap.header.size = (sizeof(event->mmap) -
290 				        (sizeof(event->mmap.filename) - size));
291 		memset(event->mmap.filename + size, 0, machine->id_hdr_size);
292 		event->mmap.header.size += machine->id_hdr_size;
293 		event->mmap.start = pos->start;
294 		event->mmap.len   = pos->end - pos->start;
295 		event->mmap.pid   = machine->pid;
296 
297 		memcpy(event->mmap.filename, pos->dso->long_name,
298 		       pos->dso->long_name_len + 1);
299 		if (process(tool, event, &synth_sample, machine) != 0) {
300 			rc = -1;
301 			break;
302 		}
303 	}
304 
305 	free(event);
306 	return rc;
307 }
308 
309 static int __event__synthesize_thread(union perf_event *comm_event,
310 				      union perf_event *mmap_event,
311 				      pid_t pid, int full,
312 					  perf_event__handler_t process,
313 				      struct perf_tool *tool,
314 				      struct machine *machine, bool mmap_data)
315 {
316 	pid_t tgid = perf_event__synthesize_comm(tool, comm_event, pid, full,
317 						 process, machine);
318 	if (tgid == -1)
319 		return -1;
320 	return perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,
321 						  process, machine, mmap_data);
322 }
323 
324 int perf_event__synthesize_thread_map(struct perf_tool *tool,
325 				      struct thread_map *threads,
326 				      perf_event__handler_t process,
327 				      struct machine *machine,
328 				      bool mmap_data)
329 {
330 	union perf_event *comm_event, *mmap_event;
331 	int err = -1, thread, j;
332 
333 	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
334 	if (comm_event == NULL)
335 		goto out;
336 
337 	mmap_event = malloc(sizeof(mmap_event->mmap) + machine->id_hdr_size);
338 	if (mmap_event == NULL)
339 		goto out_free_comm;
340 
341 	err = 0;
342 	for (thread = 0; thread < threads->nr; ++thread) {
343 		if (__event__synthesize_thread(comm_event, mmap_event,
344 					       threads->map[thread], 0,
345 					       process, tool, machine,
346 					       mmap_data)) {
347 			err = -1;
348 			break;
349 		}
350 
351 		/*
352 		 * comm.pid is set to thread group id by
353 		 * perf_event__synthesize_comm
354 		 */
355 		if ((int) comm_event->comm.pid != threads->map[thread]) {
356 			bool need_leader = true;
357 
358 			/* is thread group leader in thread_map? */
359 			for (j = 0; j < threads->nr; ++j) {
360 				if ((int) comm_event->comm.pid == threads->map[j]) {
361 					need_leader = false;
362 					break;
363 				}
364 			}
365 
366 			/* if not, generate events for it */
367 			if (need_leader &&
368 			    __event__synthesize_thread(comm_event, mmap_event,
369 						       comm_event->comm.pid, 0,
370 						       process, tool, machine,
371 						       mmap_data)) {
372 				err = -1;
373 				break;
374 			}
375 		}
376 	}
377 	free(mmap_event);
378 out_free_comm:
379 	free(comm_event);
380 out:
381 	return err;
382 }
383 
384 int perf_event__synthesize_threads(struct perf_tool *tool,
385 				   perf_event__handler_t process,
386 				   struct machine *machine, bool mmap_data)
387 {
388 	DIR *proc;
389 	struct dirent dirent, *next;
390 	union perf_event *comm_event, *mmap_event;
391 	int err = -1;
392 
393 	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
394 	if (comm_event == NULL)
395 		goto out;
396 
397 	mmap_event = malloc(sizeof(mmap_event->mmap) + machine->id_hdr_size);
398 	if (mmap_event == NULL)
399 		goto out_free_comm;
400 
401 	proc = opendir("/proc");
402 	if (proc == NULL)
403 		goto out_free_mmap;
404 
405 	while (!readdir_r(proc, &dirent, &next) && next) {
406 		char *end;
407 		pid_t pid = strtol(dirent.d_name, &end, 10);
408 
409 		if (*end) /* only interested in proper numerical dirents */
410 			continue;
411 		/*
412  		 * We may race with exiting thread, so don't stop just because
413  		 * one thread couldn't be synthesized.
414  		 */
415 		__event__synthesize_thread(comm_event, mmap_event, pid, 1,
416 					   process, tool, machine, mmap_data);
417 	}
418 
419 	err = 0;
420 	closedir(proc);
421 out_free_mmap:
422 	free(mmap_event);
423 out_free_comm:
424 	free(comm_event);
425 out:
426 	return err;
427 }
428 
429 struct process_symbol_args {
430 	const char *name;
431 	u64	   start;
432 };
433 
434 static int find_symbol_cb(void *arg, const char *name, char type,
435 			  u64 start)
436 {
437 	struct process_symbol_args *args = arg;
438 
439 	/*
440 	 * Must be a function or at least an alias, as in PARISC64, where "_text" is
441 	 * an 'A' to the same address as "_stext".
442 	 */
443 	if (!(symbol_type__is_a(type, MAP__FUNCTION) ||
444 	      type == 'A') || strcmp(name, args->name))
445 		return 0;
446 
447 	args->start = start;
448 	return 1;
449 }
450 
451 int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
452 				       perf_event__handler_t process,
453 				       struct machine *machine,
454 				       const char *symbol_name)
455 {
456 	size_t size;
457 	const char *filename, *mmap_name;
458 	char path[PATH_MAX];
459 	char name_buff[PATH_MAX];
460 	struct map *map;
461 	int err;
462 	/*
463 	 * We should get this from /sys/kernel/sections/.text, but till that is
464 	 * available use this, and after it is use this as a fallback for older
465 	 * kernels.
466 	 */
467 	struct process_symbol_args args = { .name = symbol_name, };
468 	union perf_event *event = zalloc((sizeof(event->mmap) +
469 					  machine->id_hdr_size));
470 	if (event == NULL) {
471 		pr_debug("Not enough memory synthesizing mmap event "
472 			 "for kernel modules\n");
473 		return -1;
474 	}
475 
476 	mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
477 	if (machine__is_host(machine)) {
478 		/*
479 		 * kernel uses PERF_RECORD_MISC_USER for user space maps,
480 		 * see kernel/perf_event.c __perf_event_mmap
481 		 */
482 		event->header.misc = PERF_RECORD_MISC_KERNEL;
483 		filename = "/proc/kallsyms";
484 	} else {
485 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
486 		if (machine__is_default_guest(machine))
487 			filename = (char *) symbol_conf.default_guest_kallsyms;
488 		else {
489 			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
490 			filename = path;
491 		}
492 	}
493 
494 	if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0) {
495 		free(event);
496 		return -ENOENT;
497 	}
498 
499 	map = machine->vmlinux_maps[MAP__FUNCTION];
500 	size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
501 			"%s%s", mmap_name, symbol_name) + 1;
502 	size = PERF_ALIGN(size, sizeof(u64));
503 	event->mmap.header.type = PERF_RECORD_MMAP;
504 	event->mmap.header.size = (sizeof(event->mmap) -
505 			(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
506 	event->mmap.pgoff = args.start;
507 	event->mmap.start = map->start;
508 	event->mmap.len   = map->end - event->mmap.start;
509 	event->mmap.pid   = machine->pid;
510 
511 	err = process(tool, event, &synth_sample, machine);
512 	free(event);
513 
514 	return err;
515 }
516 
517 size_t perf_event__fprintf_comm(union perf_event *event, FILE *fp)
518 {
519 	return fprintf(fp, ": %s:%d\n", event->comm.comm, event->comm.tid);
520 }
521 
522 int perf_event__process_comm(struct perf_tool *tool __maybe_unused,
523 			     union perf_event *event,
524 			     struct perf_sample *sample,
525 			     struct machine *machine)
526 {
527 	return machine__process_comm_event(machine, event, sample);
528 }
529 
530 int perf_event__process_lost(struct perf_tool *tool __maybe_unused,
531 			     union perf_event *event,
532 			     struct perf_sample *sample,
533 			     struct machine *machine)
534 {
535 	return machine__process_lost_event(machine, event, sample);
536 }
537 
538 size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
539 {
540 	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %c %s\n",
541 		       event->mmap.pid, event->mmap.tid, event->mmap.start,
542 		       event->mmap.len, event->mmap.pgoff,
543 		       (event->header.misc & PERF_RECORD_MISC_MMAP_DATA) ? 'r' : 'x',
544 		       event->mmap.filename);
545 }
546 
547 size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp)
548 {
549 	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64
550 			   " %02x:%02x %"PRIu64" %"PRIu64"]: %c %s\n",
551 		       event->mmap2.pid, event->mmap2.tid, event->mmap2.start,
552 		       event->mmap2.len, event->mmap2.pgoff, event->mmap2.maj,
553 		       event->mmap2.min, event->mmap2.ino,
554 		       event->mmap2.ino_generation,
555 		       (event->header.misc & PERF_RECORD_MISC_MMAP_DATA) ? 'r' : 'x',
556 		       event->mmap2.filename);
557 }
558 
559 int perf_event__process_mmap(struct perf_tool *tool __maybe_unused,
560 			     union perf_event *event,
561 			     struct perf_sample *sample,
562 			     struct machine *machine)
563 {
564 	return machine__process_mmap_event(machine, event, sample);
565 }
566 
567 int perf_event__process_mmap2(struct perf_tool *tool __maybe_unused,
568 			     union perf_event *event,
569 			     struct perf_sample *sample,
570 			     struct machine *machine)
571 {
572 	return machine__process_mmap2_event(machine, event, sample);
573 }
574 
575 size_t perf_event__fprintf_task(union perf_event *event, FILE *fp)
576 {
577 	return fprintf(fp, "(%d:%d):(%d:%d)\n",
578 		       event->fork.pid, event->fork.tid,
579 		       event->fork.ppid, event->fork.ptid);
580 }
581 
582 int perf_event__process_fork(struct perf_tool *tool __maybe_unused,
583 			     union perf_event *event,
584 			     struct perf_sample *sample,
585 			     struct machine *machine)
586 {
587 	return machine__process_fork_event(machine, event, sample);
588 }
589 
590 int perf_event__process_exit(struct perf_tool *tool __maybe_unused,
591 			     union perf_event *event,
592 			     struct perf_sample *sample,
593 			     struct machine *machine)
594 {
595 	return machine__process_exit_event(machine, event, sample);
596 }
597 
598 size_t perf_event__fprintf(union perf_event *event, FILE *fp)
599 {
600 	size_t ret = fprintf(fp, "PERF_RECORD_%s",
601 			     perf_event__name(event->header.type));
602 
603 	switch (event->header.type) {
604 	case PERF_RECORD_COMM:
605 		ret += perf_event__fprintf_comm(event, fp);
606 		break;
607 	case PERF_RECORD_FORK:
608 	case PERF_RECORD_EXIT:
609 		ret += perf_event__fprintf_task(event, fp);
610 		break;
611 	case PERF_RECORD_MMAP:
612 		ret += perf_event__fprintf_mmap(event, fp);
613 		break;
614 	case PERF_RECORD_MMAP2:
615 		ret += perf_event__fprintf_mmap2(event, fp);
616 		break;
617 	default:
618 		ret += fprintf(fp, "\n");
619 	}
620 
621 	return ret;
622 }
623 
624 int perf_event__process(struct perf_tool *tool __maybe_unused,
625 			union perf_event *event,
626 			struct perf_sample *sample,
627 			struct machine *machine)
628 {
629 	return machine__process_event(machine, event, sample);
630 }
631 
632 void thread__find_addr_map(struct thread *thread,
633 			   struct machine *machine, u8 cpumode,
634 			   enum map_type type, u64 addr,
635 			   struct addr_location *al)
636 {
637 	struct map_groups *mg = &thread->mg;
638 	bool load_map = false;
639 
640 	al->thread = thread;
641 	al->addr = addr;
642 	al->cpumode = cpumode;
643 	al->filtered = false;
644 
645 	if (machine == NULL) {
646 		al->map = NULL;
647 		return;
648 	}
649 
650 	if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
651 		al->level = 'k';
652 		mg = &machine->kmaps;
653 		load_map = true;
654 	} else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
655 		al->level = '.';
656 	} else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
657 		al->level = 'g';
658 		mg = &machine->kmaps;
659 		load_map = true;
660 	} else {
661 		/*
662 		 * 'u' means guest os user space.
663 		 * TODO: We don't support guest user space. Might support late.
664 		 */
665 		if (cpumode == PERF_RECORD_MISC_GUEST_USER && perf_guest)
666 			al->level = 'u';
667 		else
668 			al->level = 'H';
669 		al->map = NULL;
670 
671 		if ((cpumode == PERF_RECORD_MISC_GUEST_USER ||
672 			cpumode == PERF_RECORD_MISC_GUEST_KERNEL) &&
673 			!perf_guest)
674 			al->filtered = true;
675 		if ((cpumode == PERF_RECORD_MISC_USER ||
676 			cpumode == PERF_RECORD_MISC_KERNEL) &&
677 			!perf_host)
678 			al->filtered = true;
679 
680 		return;
681 	}
682 try_again:
683 	al->map = map_groups__find(mg, type, al->addr);
684 	if (al->map == NULL) {
685 		/*
686 		 * If this is outside of all known maps, and is a negative
687 		 * address, try to look it up in the kernel dso, as it might be
688 		 * a vsyscall or vdso (which executes in user-mode).
689 		 *
690 		 * XXX This is nasty, we should have a symbol list in the
691 		 * "[vdso]" dso, but for now lets use the old trick of looking
692 		 * in the whole kernel symbol list.
693 		 */
694 		if ((long long)al->addr < 0 &&
695 		    cpumode == PERF_RECORD_MISC_USER &&
696 		    machine && mg != &machine->kmaps) {
697 			mg = &machine->kmaps;
698 			goto try_again;
699 		}
700 	} else {
701 		/*
702 		 * Kernel maps might be changed when loading symbols so loading
703 		 * must be done prior to using kernel maps.
704 		 */
705 		if (load_map)
706 			map__load(al->map, machine->symbol_filter);
707 		al->addr = al->map->map_ip(al->map, al->addr);
708 	}
709 }
710 
711 void thread__find_addr_location(struct thread *thread, struct machine *machine,
712 				u8 cpumode, enum map_type type, u64 addr,
713 				struct addr_location *al)
714 {
715 	thread__find_addr_map(thread, machine, cpumode, type, addr, al);
716 	if (al->map != NULL)
717 		al->sym = map__find_symbol(al->map, al->addr,
718 					   machine->symbol_filter);
719 	else
720 		al->sym = NULL;
721 }
722 
723 int perf_event__preprocess_sample(const union perf_event *event,
724 				  struct machine *machine,
725 				  struct addr_location *al,
726 				  struct perf_sample *sample)
727 {
728 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
729 	struct thread *thread = machine__findnew_thread(machine, sample->pid,
730 							sample->pid);
731 
732 	if (thread == NULL)
733 		return -1;
734 
735 	if (symbol_conf.comm_list &&
736 	    !strlist__has_entry(symbol_conf.comm_list, thread__comm_str(thread)))
737 		goto out_filtered;
738 
739 	dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), thread->tid);
740 	/*
741 	 * Have we already created the kernel maps for this machine?
742 	 *
743 	 * This should have happened earlier, when we processed the kernel MMAP
744 	 * events, but for older perf.data files there was no such thing, so do
745 	 * it now.
746 	 */
747 	if (cpumode == PERF_RECORD_MISC_KERNEL &&
748 	    machine->vmlinux_maps[MAP__FUNCTION] == NULL)
749 		machine__create_kernel_maps(machine);
750 
751 	thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
752 			      sample->ip, al);
753 	dump_printf(" ...... dso: %s\n",
754 		    al->map ? al->map->dso->long_name :
755 			al->level == 'H' ? "[hypervisor]" : "<not found>");
756 	al->sym = NULL;
757 	al->cpu = sample->cpu;
758 
759 	if (al->map) {
760 		struct dso *dso = al->map->dso;
761 
762 		if (symbol_conf.dso_list &&
763 		    (!dso || !(strlist__has_entry(symbol_conf.dso_list,
764 						  dso->short_name) ||
765 			       (dso->short_name != dso->long_name &&
766 				strlist__has_entry(symbol_conf.dso_list,
767 						   dso->long_name)))))
768 			goto out_filtered;
769 
770 		al->sym = map__find_symbol(al->map, al->addr,
771 					   machine->symbol_filter);
772 	}
773 
774 	if (symbol_conf.sym_list &&
775 		(!al->sym || !strlist__has_entry(symbol_conf.sym_list,
776 						al->sym->name)))
777 		goto out_filtered;
778 
779 	return 0;
780 
781 out_filtered:
782 	al->filtered = true;
783 	return 0;
784 }
785