xref: /linux/tools/perf/util/event.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
1 #include <linux/types.h>
2 #include "event.h"
3 #include "debug.h"
4 #include "session.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_LOST]			= "LOST",
15 	[PERF_RECORD_COMM]			= "COMM",
16 	[PERF_RECORD_EXIT]			= "EXIT",
17 	[PERF_RECORD_THROTTLE]			= "THROTTLE",
18 	[PERF_RECORD_UNTHROTTLE]		= "UNTHROTTLE",
19 	[PERF_RECORD_FORK]			= "FORK",
20 	[PERF_RECORD_READ]			= "READ",
21 	[PERF_RECORD_SAMPLE]			= "SAMPLE",
22 	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
23 	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
24 	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
25 	[PERF_RECORD_HEADER_BUILD_ID]		= "BUILD_ID",
26 	[PERF_RECORD_FINISHED_ROUND]		= "FINISHED_ROUND",
27 };
28 
29 const char *perf_event__name(unsigned int id)
30 {
31 	if (id >= ARRAY_SIZE(perf_event__names))
32 		return "INVALID";
33 	if (!perf_event__names[id])
34 		return "UNKNOWN";
35 	return perf_event__names[id];
36 }
37 
38 static struct perf_sample synth_sample = {
39 	.pid	   = -1,
40 	.tid	   = -1,
41 	.time	   = -1,
42 	.stream_id = -1,
43 	.cpu	   = -1,
44 	.period	   = 1,
45 };
46 
47 static pid_t perf_event__synthesize_comm(union perf_event *event, pid_t pid,
48 					 int full, perf_event__handler_t process,
49 					 struct perf_session *session)
50 {
51 	char filename[PATH_MAX];
52 	char bf[BUFSIZ];
53 	FILE *fp;
54 	size_t size = 0;
55 	DIR *tasks;
56 	struct dirent dirent, *next;
57 	pid_t tgid = 0;
58 
59 	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
60 
61 	fp = fopen(filename, "r");
62 	if (fp == NULL) {
63 out_race:
64 		/*
65 		 * We raced with a task exiting - just return:
66 		 */
67 		pr_debug("couldn't open %s\n", filename);
68 		return 0;
69 	}
70 
71 	memset(&event->comm, 0, sizeof(event->comm));
72 
73 	while (!event->comm.comm[0] || !event->comm.pid) {
74 		if (fgets(bf, sizeof(bf), fp) == NULL) {
75 			pr_warning("couldn't get COMM and pgid, malformed %s\n", filename);
76 			goto out;
77 		}
78 
79 		if (memcmp(bf, "Name:", 5) == 0) {
80 			char *name = bf + 5;
81 			while (*name && isspace(*name))
82 				++name;
83 			size = strlen(name) - 1;
84 			memcpy(event->comm.comm, name, size++);
85 		} else if (memcmp(bf, "Tgid:", 5) == 0) {
86 			char *tgids = bf + 5;
87 			while (*tgids && isspace(*tgids))
88 				++tgids;
89 			tgid = event->comm.pid = atoi(tgids);
90 		}
91 	}
92 
93 	event->comm.header.type = PERF_RECORD_COMM;
94 	size = ALIGN(size, sizeof(u64));
95 	memset(event->comm.comm + size, 0, session->id_hdr_size);
96 	event->comm.header.size = (sizeof(event->comm) -
97 				(sizeof(event->comm.comm) - size) +
98 				session->id_hdr_size);
99 	if (!full) {
100 		event->comm.tid = pid;
101 
102 		process(event, &synth_sample, session);
103 		goto out;
104 	}
105 
106 	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
107 
108 	tasks = opendir(filename);
109 	if (tasks == NULL)
110 		goto out_race;
111 
112 	while (!readdir_r(tasks, &dirent, &next) && next) {
113 		char *end;
114 		pid = strtol(dirent.d_name, &end, 10);
115 		if (*end)
116 			continue;
117 
118 		event->comm.tid = pid;
119 
120 		process(event, &synth_sample, session);
121 	}
122 
123 	closedir(tasks);
124 out:
125 	fclose(fp);
126 
127 	return tgid;
128 }
129 
130 static int perf_event__synthesize_mmap_events(union perf_event *event,
131 					      pid_t pid, pid_t tgid,
132 					      perf_event__handler_t process,
133 					      struct perf_session *session)
134 {
135 	char filename[PATH_MAX];
136 	FILE *fp;
137 
138 	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
139 
140 	fp = fopen(filename, "r");
141 	if (fp == NULL) {
142 		/*
143 		 * We raced with a task exiting - just return:
144 		 */
145 		pr_debug("couldn't open %s\n", filename);
146 		return -1;
147 	}
148 
149 	event->header.type = PERF_RECORD_MMAP;
150 	/*
151 	 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
152 	 */
153 	event->header.misc = PERF_RECORD_MISC_USER;
154 
155 	while (1) {
156 		char bf[BUFSIZ], *pbf = bf;
157 		int n;
158 		size_t size;
159 		if (fgets(bf, sizeof(bf), fp) == NULL)
160 			break;
161 
162 		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
163 		n = hex2u64(pbf, &event->mmap.start);
164 		if (n < 0)
165 			continue;
166 		pbf += n + 1;
167 		n = hex2u64(pbf, &event->mmap.len);
168 		if (n < 0)
169 			continue;
170 		pbf += n + 3;
171 		if (*pbf == 'x') { /* vm_exec */
172 			char anonstr[] = "//anon\n";
173 			char *execname = strchr(bf, '/');
174 
175 			/* Catch VDSO */
176 			if (execname == NULL)
177 				execname = strstr(bf, "[vdso]");
178 
179 			/* Catch anonymous mmaps */
180 			if ((execname == NULL) && !strstr(bf, "["))
181 				execname = anonstr;
182 
183 			if (execname == NULL)
184 				continue;
185 
186 			pbf += 3;
187 			n = hex2u64(pbf, &event->mmap.pgoff);
188 
189 			size = strlen(execname);
190 			execname[size - 1] = '\0'; /* Remove \n */
191 			memcpy(event->mmap.filename, execname, size);
192 			size = ALIGN(size, sizeof(u64));
193 			event->mmap.len -= event->mmap.start;
194 			event->mmap.header.size = (sizeof(event->mmap) -
195 					        (sizeof(event->mmap.filename) - size));
196 			memset(event->mmap.filename + size, 0, session->id_hdr_size);
197 			event->mmap.header.size += session->id_hdr_size;
198 			event->mmap.pid = tgid;
199 			event->mmap.tid = pid;
200 
201 			process(event, &synth_sample, session);
202 		}
203 	}
204 
205 	fclose(fp);
206 	return 0;
207 }
208 
209 int perf_event__synthesize_modules(perf_event__handler_t process,
210 				   struct perf_session *session,
211 				   struct machine *machine)
212 {
213 	struct rb_node *nd;
214 	struct map_groups *kmaps = &machine->kmaps;
215 	union perf_event *event = zalloc((sizeof(event->mmap) +
216 					  session->id_hdr_size));
217 	if (event == NULL) {
218 		pr_debug("Not enough memory synthesizing mmap event "
219 			 "for kernel modules\n");
220 		return -1;
221 	}
222 
223 	event->header.type = PERF_RECORD_MMAP;
224 
225 	/*
226 	 * kernel uses 0 for user space maps, see kernel/perf_event.c
227 	 * __perf_event_mmap
228 	 */
229 	if (machine__is_host(machine))
230 		event->header.misc = PERF_RECORD_MISC_KERNEL;
231 	else
232 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
233 
234 	for (nd = rb_first(&kmaps->maps[MAP__FUNCTION]);
235 	     nd; nd = rb_next(nd)) {
236 		size_t size;
237 		struct map *pos = rb_entry(nd, struct map, rb_node);
238 
239 		if (pos->dso->kernel)
240 			continue;
241 
242 		size = ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
243 		event->mmap.header.type = PERF_RECORD_MMAP;
244 		event->mmap.header.size = (sizeof(event->mmap) -
245 				        (sizeof(event->mmap.filename) - size));
246 		memset(event->mmap.filename + size, 0, session->id_hdr_size);
247 		event->mmap.header.size += session->id_hdr_size;
248 		event->mmap.start = pos->start;
249 		event->mmap.len   = pos->end - pos->start;
250 		event->mmap.pid   = machine->pid;
251 
252 		memcpy(event->mmap.filename, pos->dso->long_name,
253 		       pos->dso->long_name_len + 1);
254 		process(event, &synth_sample, session);
255 	}
256 
257 	free(event);
258 	return 0;
259 }
260 
261 static int __event__synthesize_thread(union perf_event *comm_event,
262 				      union perf_event *mmap_event,
263 				      pid_t pid, perf_event__handler_t process,
264 				      struct perf_session *session)
265 {
266 	pid_t tgid = perf_event__synthesize_comm(comm_event, pid, 1, process,
267 					    session);
268 	if (tgid == -1)
269 		return -1;
270 	return perf_event__synthesize_mmap_events(mmap_event, pid, tgid,
271 					     process, session);
272 }
273 
274 int perf_event__synthesize_thread_map(struct thread_map *threads,
275 				      perf_event__handler_t process,
276 				      struct perf_session *session)
277 {
278 	union perf_event *comm_event, *mmap_event;
279 	int err = -1, thread;
280 
281 	comm_event = malloc(sizeof(comm_event->comm) + session->id_hdr_size);
282 	if (comm_event == NULL)
283 		goto out;
284 
285 	mmap_event = malloc(sizeof(mmap_event->mmap) + session->id_hdr_size);
286 	if (mmap_event == NULL)
287 		goto out_free_comm;
288 
289 	err = 0;
290 	for (thread = 0; thread < threads->nr; ++thread) {
291 		if (__event__synthesize_thread(comm_event, mmap_event,
292 					       threads->map[thread],
293 					       process, session)) {
294 			err = -1;
295 			break;
296 		}
297 	}
298 	free(mmap_event);
299 out_free_comm:
300 	free(comm_event);
301 out:
302 	return err;
303 }
304 
305 int perf_event__synthesize_threads(perf_event__handler_t process,
306 				   struct perf_session *session)
307 {
308 	DIR *proc;
309 	struct dirent dirent, *next;
310 	union perf_event *comm_event, *mmap_event;
311 	int err = -1;
312 
313 	comm_event = malloc(sizeof(comm_event->comm) + session->id_hdr_size);
314 	if (comm_event == NULL)
315 		goto out;
316 
317 	mmap_event = malloc(sizeof(mmap_event->mmap) + session->id_hdr_size);
318 	if (mmap_event == NULL)
319 		goto out_free_comm;
320 
321 	proc = opendir("/proc");
322 	if (proc == NULL)
323 		goto out_free_mmap;
324 
325 	while (!readdir_r(proc, &dirent, &next) && next) {
326 		char *end;
327 		pid_t pid = strtol(dirent.d_name, &end, 10);
328 
329 		if (*end) /* only interested in proper numerical dirents */
330 			continue;
331 
332 		__event__synthesize_thread(comm_event, mmap_event, pid,
333 					   process, session);
334 	}
335 
336 	closedir(proc);
337 	err = 0;
338 out_free_mmap:
339 	free(mmap_event);
340 out_free_comm:
341 	free(comm_event);
342 out:
343 	return err;
344 }
345 
346 struct process_symbol_args {
347 	const char *name;
348 	u64	   start;
349 };
350 
351 static int find_symbol_cb(void *arg, const char *name, char type,
352 			  u64 start, u64 end __used)
353 {
354 	struct process_symbol_args *args = arg;
355 
356 	/*
357 	 * Must be a function or at least an alias, as in PARISC64, where "_text" is
358 	 * an 'A' to the same address as "_stext".
359 	 */
360 	if (!(symbol_type__is_a(type, MAP__FUNCTION) ||
361 	      type == 'A') || strcmp(name, args->name))
362 		return 0;
363 
364 	args->start = start;
365 	return 1;
366 }
367 
368 int perf_event__synthesize_kernel_mmap(perf_event__handler_t process,
369 				       struct perf_session *session,
370 				       struct machine *machine,
371 				       const char *symbol_name)
372 {
373 	size_t size;
374 	const char *filename, *mmap_name;
375 	char path[PATH_MAX];
376 	char name_buff[PATH_MAX];
377 	struct map *map;
378 	int err;
379 	/*
380 	 * We should get this from /sys/kernel/sections/.text, but till that is
381 	 * available use this, and after it is use this as a fallback for older
382 	 * kernels.
383 	 */
384 	struct process_symbol_args args = { .name = symbol_name, };
385 	union perf_event *event = zalloc((sizeof(event->mmap) +
386 					  session->id_hdr_size));
387 	if (event == NULL) {
388 		pr_debug("Not enough memory synthesizing mmap event "
389 			 "for kernel modules\n");
390 		return -1;
391 	}
392 
393 	mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
394 	if (machine__is_host(machine)) {
395 		/*
396 		 * kernel uses PERF_RECORD_MISC_USER for user space maps,
397 		 * see kernel/perf_event.c __perf_event_mmap
398 		 */
399 		event->header.misc = PERF_RECORD_MISC_KERNEL;
400 		filename = "/proc/kallsyms";
401 	} else {
402 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
403 		if (machine__is_default_guest(machine))
404 			filename = (char *) symbol_conf.default_guest_kallsyms;
405 		else {
406 			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
407 			filename = path;
408 		}
409 	}
410 
411 	if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0)
412 		return -ENOENT;
413 
414 	map = machine->vmlinux_maps[MAP__FUNCTION];
415 	size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
416 			"%s%s", mmap_name, symbol_name) + 1;
417 	size = ALIGN(size, sizeof(u64));
418 	event->mmap.header.type = PERF_RECORD_MMAP;
419 	event->mmap.header.size = (sizeof(event->mmap) -
420 			(sizeof(event->mmap.filename) - size) + session->id_hdr_size);
421 	event->mmap.pgoff = args.start;
422 	event->mmap.start = map->start;
423 	event->mmap.len   = map->end - event->mmap.start;
424 	event->mmap.pid   = machine->pid;
425 
426 	err = process(event, &synth_sample, session);
427 	free(event);
428 
429 	return err;
430 }
431 
432 int perf_event__process_comm(union perf_event *event,
433 			     struct perf_sample *sample __used,
434 			     struct perf_session *session)
435 {
436 	struct thread *thread = perf_session__findnew(session, event->comm.tid);
437 
438 	dump_printf(": %s:%d\n", event->comm.comm, event->comm.tid);
439 
440 	if (thread == NULL || thread__set_comm(thread, event->comm.comm)) {
441 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
442 		return -1;
443 	}
444 
445 	return 0;
446 }
447 
448 int perf_event__process_lost(union perf_event *event,
449 			     struct perf_sample *sample __used,
450 			     struct perf_session *session)
451 {
452 	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
453 		    event->lost.id, event->lost.lost);
454 	session->hists.stats.total_lost += event->lost.lost;
455 	return 0;
456 }
457 
458 static void perf_event__set_kernel_mmap_len(union perf_event *event,
459 					    struct map **maps)
460 {
461 	maps[MAP__FUNCTION]->start = event->mmap.start;
462 	maps[MAP__FUNCTION]->end   = event->mmap.start + event->mmap.len;
463 	/*
464 	 * Be a bit paranoid here, some perf.data file came with
465 	 * a zero sized synthesized MMAP event for the kernel.
466 	 */
467 	if (maps[MAP__FUNCTION]->end == 0)
468 		maps[MAP__FUNCTION]->end = ~0ULL;
469 }
470 
471 static int perf_event__process_kernel_mmap(union perf_event *event,
472 					   struct perf_session *session)
473 {
474 	struct map *map;
475 	char kmmap_prefix[PATH_MAX];
476 	struct machine *machine;
477 	enum dso_kernel_type kernel_type;
478 	bool is_kernel_mmap;
479 
480 	machine = perf_session__findnew_machine(session, event->mmap.pid);
481 	if (!machine) {
482 		pr_err("Can't find id %d's machine\n", event->mmap.pid);
483 		goto out_problem;
484 	}
485 
486 	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
487 	if (machine__is_host(machine))
488 		kernel_type = DSO_TYPE_KERNEL;
489 	else
490 		kernel_type = DSO_TYPE_GUEST_KERNEL;
491 
492 	is_kernel_mmap = memcmp(event->mmap.filename,
493 				kmmap_prefix,
494 				strlen(kmmap_prefix)) == 0;
495 	if (event->mmap.filename[0] == '/' ||
496 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
497 
498 		char short_module_name[1024];
499 		char *name, *dot;
500 
501 		if (event->mmap.filename[0] == '/') {
502 			name = strrchr(event->mmap.filename, '/');
503 			if (name == NULL)
504 				goto out_problem;
505 
506 			++name; /* skip / */
507 			dot = strrchr(name, '.');
508 			if (dot == NULL)
509 				goto out_problem;
510 			snprintf(short_module_name, sizeof(short_module_name),
511 					"[%.*s]", (int)(dot - name), name);
512 			strxfrchar(short_module_name, '-', '_');
513 		} else
514 			strcpy(short_module_name, event->mmap.filename);
515 
516 		map = machine__new_module(machine, event->mmap.start,
517 					  event->mmap.filename);
518 		if (map == NULL)
519 			goto out_problem;
520 
521 		name = strdup(short_module_name);
522 		if (name == NULL)
523 			goto out_problem;
524 
525 		map->dso->short_name = name;
526 		map->dso->sname_alloc = 1;
527 		map->end = map->start + event->mmap.len;
528 	} else if (is_kernel_mmap) {
529 		const char *symbol_name = (event->mmap.filename +
530 				strlen(kmmap_prefix));
531 		/*
532 		 * Should be there already, from the build-id table in
533 		 * the header.
534 		 */
535 		struct dso *kernel = __dsos__findnew(&machine->kernel_dsos,
536 						     kmmap_prefix);
537 		if (kernel == NULL)
538 			goto out_problem;
539 
540 		kernel->kernel = kernel_type;
541 		if (__machine__create_kernel_maps(machine, kernel) < 0)
542 			goto out_problem;
543 
544 		perf_event__set_kernel_mmap_len(event, machine->vmlinux_maps);
545 
546 		/*
547 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
548 		 * symbol. Effectively having zero here means that at record
549 		 * time /proc/sys/kernel/kptr_restrict was non zero.
550 		 */
551 		if (event->mmap.pgoff != 0) {
552 			perf_session__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
553 								 symbol_name,
554 								 event->mmap.pgoff);
555 		}
556 
557 		if (machine__is_default_guest(machine)) {
558 			/*
559 			 * preload dso of guest kernel and modules
560 			 */
561 			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
562 				  NULL);
563 		}
564 	}
565 	return 0;
566 out_problem:
567 	return -1;
568 }
569 
570 int perf_event__process_mmap(union perf_event *event,
571 			     struct perf_sample *sample __used,
572 			     struct perf_session *session)
573 {
574 	struct machine *machine;
575 	struct thread *thread;
576 	struct map *map;
577 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
578 	int ret = 0;
579 
580 	dump_printf(" %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %s\n",
581 			event->mmap.pid, event->mmap.tid, event->mmap.start,
582 			event->mmap.len, event->mmap.pgoff, event->mmap.filename);
583 
584 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
585 	    cpumode == PERF_RECORD_MISC_KERNEL) {
586 		ret = perf_event__process_kernel_mmap(event, session);
587 		if (ret < 0)
588 			goto out_problem;
589 		return 0;
590 	}
591 
592 	machine = perf_session__find_host_machine(session);
593 	if (machine == NULL)
594 		goto out_problem;
595 	thread = perf_session__findnew(session, event->mmap.pid);
596 	if (thread == NULL)
597 		goto out_problem;
598 	map = map__new(&machine->user_dsos, event->mmap.start,
599 			event->mmap.len, event->mmap.pgoff,
600 			event->mmap.pid, event->mmap.filename,
601 			MAP__FUNCTION);
602 	if (map == NULL)
603 		goto out_problem;
604 
605 	thread__insert_map(thread, map);
606 	return 0;
607 
608 out_problem:
609 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
610 	return 0;
611 }
612 
613 int perf_event__process_task(union perf_event *event,
614 			     struct perf_sample *sample __used,
615 			     struct perf_session *session)
616 {
617 	struct thread *thread = perf_session__findnew(session, event->fork.tid);
618 	struct thread *parent = perf_session__findnew(session, event->fork.ptid);
619 
620 	dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
621 		    event->fork.ppid, event->fork.ptid);
622 
623 	if (event->header.type == PERF_RECORD_EXIT) {
624 		perf_session__remove_thread(session, thread);
625 		return 0;
626 	}
627 
628 	if (thread == NULL || parent == NULL ||
629 	    thread__fork(thread, parent) < 0) {
630 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
631 		return -1;
632 	}
633 
634 	return 0;
635 }
636 
637 int perf_event__process(union perf_event *event, struct perf_sample *sample,
638 			struct perf_session *session)
639 {
640 	switch (event->header.type) {
641 	case PERF_RECORD_COMM:
642 		perf_event__process_comm(event, sample, session);
643 		break;
644 	case PERF_RECORD_MMAP:
645 		perf_event__process_mmap(event, sample, session);
646 		break;
647 	case PERF_RECORD_FORK:
648 	case PERF_RECORD_EXIT:
649 		perf_event__process_task(event, sample, session);
650 		break;
651 	case PERF_RECORD_LOST:
652 		perf_event__process_lost(event, sample, session);
653 	default:
654 		break;
655 	}
656 
657 	return 0;
658 }
659 
660 void thread__find_addr_map(struct thread *self,
661 			   struct perf_session *session, u8 cpumode,
662 			   enum map_type type, pid_t pid, u64 addr,
663 			   struct addr_location *al)
664 {
665 	struct map_groups *mg = &self->mg;
666 	struct machine *machine = NULL;
667 
668 	al->thread = self;
669 	al->addr = addr;
670 	al->cpumode = cpumode;
671 	al->filtered = false;
672 
673 	if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
674 		al->level = 'k';
675 		machine = perf_session__find_host_machine(session);
676 		if (machine == NULL) {
677 			al->map = NULL;
678 			return;
679 		}
680 		mg = &machine->kmaps;
681 	} else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
682 		al->level = '.';
683 		machine = perf_session__find_host_machine(session);
684 	} else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
685 		al->level = 'g';
686 		machine = perf_session__find_machine(session, pid);
687 		if (machine == NULL) {
688 			al->map = NULL;
689 			return;
690 		}
691 		mg = &machine->kmaps;
692 	} else {
693 		/*
694 		 * 'u' means guest os user space.
695 		 * TODO: We don't support guest user space. Might support late.
696 		 */
697 		if (cpumode == PERF_RECORD_MISC_GUEST_USER && perf_guest)
698 			al->level = 'u';
699 		else
700 			al->level = 'H';
701 		al->map = NULL;
702 
703 		if ((cpumode == PERF_RECORD_MISC_GUEST_USER ||
704 			cpumode == PERF_RECORD_MISC_GUEST_KERNEL) &&
705 			!perf_guest)
706 			al->filtered = true;
707 		if ((cpumode == PERF_RECORD_MISC_USER ||
708 			cpumode == PERF_RECORD_MISC_KERNEL) &&
709 			!perf_host)
710 			al->filtered = true;
711 
712 		return;
713 	}
714 try_again:
715 	al->map = map_groups__find(mg, type, al->addr);
716 	if (al->map == NULL) {
717 		/*
718 		 * If this is outside of all known maps, and is a negative
719 		 * address, try to look it up in the kernel dso, as it might be
720 		 * a vsyscall or vdso (which executes in user-mode).
721 		 *
722 		 * XXX This is nasty, we should have a symbol list in the
723 		 * "[vdso]" dso, but for now lets use the old trick of looking
724 		 * in the whole kernel symbol list.
725 		 */
726 		if ((long long)al->addr < 0 &&
727 		    cpumode == PERF_RECORD_MISC_USER &&
728 		    machine && mg != &machine->kmaps) {
729 			mg = &machine->kmaps;
730 			goto try_again;
731 		}
732 	} else
733 		al->addr = al->map->map_ip(al->map, al->addr);
734 }
735 
736 void thread__find_addr_location(struct thread *self,
737 				struct perf_session *session, u8 cpumode,
738 				enum map_type type, pid_t pid, u64 addr,
739 				struct addr_location *al,
740 				symbol_filter_t filter)
741 {
742 	thread__find_addr_map(self, session, cpumode, type, pid, addr, al);
743 	if (al->map != NULL)
744 		al->sym = map__find_symbol(al->map, al->addr, filter);
745 	else
746 		al->sym = NULL;
747 }
748 
749 int perf_event__preprocess_sample(const union perf_event *event,
750 				  struct perf_session *session,
751 				  struct addr_location *al,
752 				  struct perf_sample *sample,
753 				  symbol_filter_t filter)
754 {
755 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
756 	struct thread *thread = perf_session__findnew(session, event->ip.pid);
757 
758 	if (thread == NULL)
759 		return -1;
760 
761 	if (symbol_conf.comm_list &&
762 	    !strlist__has_entry(symbol_conf.comm_list, thread->comm))
763 		goto out_filtered;
764 
765 	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
766 	/*
767 	 * Have we already created the kernel maps for the host machine?
768 	 *
769 	 * This should have happened earlier, when we processed the kernel MMAP
770 	 * events, but for older perf.data files there was no such thing, so do
771 	 * it now.
772 	 */
773 	if (cpumode == PERF_RECORD_MISC_KERNEL &&
774 	    session->host_machine.vmlinux_maps[MAP__FUNCTION] == NULL)
775 		machine__create_kernel_maps(&session->host_machine);
776 
777 	thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
778 			      event->ip.pid, event->ip.ip, al);
779 	dump_printf(" ...... dso: %s\n",
780 		    al->map ? al->map->dso->long_name :
781 			al->level == 'H' ? "[hypervisor]" : "<not found>");
782 	al->sym = NULL;
783 	al->cpu = sample->cpu;
784 
785 	if (al->map) {
786 		if (symbol_conf.dso_list &&
787 		    (!al->map || !al->map->dso ||
788 		     !(strlist__has_entry(symbol_conf.dso_list,
789 					  al->map->dso->short_name) ||
790 		       (al->map->dso->short_name != al->map->dso->long_name &&
791 			strlist__has_entry(symbol_conf.dso_list,
792 					   al->map->dso->long_name)))))
793 			goto out_filtered;
794 
795 		al->sym = map__find_symbol(al->map, al->addr, filter);
796 	}
797 
798 	if (symbol_conf.sym_list && al->sym &&
799 	    !strlist__has_entry(symbol_conf.sym_list, al->sym->name))
800 		goto out_filtered;
801 
802 	return 0;
803 
804 out_filtered:
805 	al->filtered = true;
806 	return 0;
807 }
808