xref: /linux/tools/perf/util/machine.c (revision 9402e23f90c5a672db7170e4c0f1fc80ca8c009a)
1 #include "callchain.h"
2 #include "debug.h"
3 #include "event.h"
4 #include "evsel.h"
5 #include "hist.h"
6 #include "machine.h"
7 #include "map.h"
8 #include "sort.h"
9 #include "strlist.h"
10 #include "thread.h"
11 #include "vdso.h"
12 #include <stdbool.h>
13 #include <symbol/kallsyms.h>
14 #include "unwind.h"
15 #include "linux/hash.h"
16 
17 static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock);
18 
19 static void dsos__init(struct dsos *dsos)
20 {
21 	INIT_LIST_HEAD(&dsos->head);
22 	dsos->root = RB_ROOT;
23 }
24 
25 int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
26 {
27 	map_groups__init(&machine->kmaps, machine);
28 	RB_CLEAR_NODE(&machine->rb_node);
29 	dsos__init(&machine->user_dsos);
30 	dsos__init(&machine->kernel_dsos);
31 
32 	machine->threads = RB_ROOT;
33 	pthread_rwlock_init(&machine->threads_lock, NULL);
34 	INIT_LIST_HEAD(&machine->dead_threads);
35 	machine->last_match = NULL;
36 
37 	machine->vdso_info = NULL;
38 
39 	machine->pid = pid;
40 
41 	machine->symbol_filter = NULL;
42 	machine->id_hdr_size = 0;
43 	machine->comm_exec = false;
44 	machine->kernel_start = 0;
45 
46 	machine->root_dir = strdup(root_dir);
47 	if (machine->root_dir == NULL)
48 		return -ENOMEM;
49 
50 	if (pid != HOST_KERNEL_ID) {
51 		struct thread *thread = machine__findnew_thread(machine, -1,
52 								pid);
53 		char comm[64];
54 
55 		if (thread == NULL)
56 			return -ENOMEM;
57 
58 		snprintf(comm, sizeof(comm), "[guest/%d]", pid);
59 		thread__set_comm(thread, comm, 0);
60 		thread__put(thread);
61 	}
62 
63 	machine->current_tid = NULL;
64 
65 	return 0;
66 }
67 
68 struct machine *machine__new_host(void)
69 {
70 	struct machine *machine = malloc(sizeof(*machine));
71 
72 	if (machine != NULL) {
73 		machine__init(machine, "", HOST_KERNEL_ID);
74 
75 		if (machine__create_kernel_maps(machine) < 0)
76 			goto out_delete;
77 	}
78 
79 	return machine;
80 out_delete:
81 	free(machine);
82 	return NULL;
83 }
84 
85 static void dsos__delete(struct dsos *dsos)
86 {
87 	struct dso *pos, *n;
88 
89 	list_for_each_entry_safe(pos, n, &dsos->head, node) {
90 		RB_CLEAR_NODE(&pos->rb_node);
91 		list_del(&pos->node);
92 		dso__delete(pos);
93 	}
94 }
95 
96 void machine__delete_threads(struct machine *machine)
97 {
98 	struct rb_node *nd;
99 
100 	pthread_rwlock_wrlock(&machine->threads_lock);
101 	nd = rb_first(&machine->threads);
102 	while (nd) {
103 		struct thread *t = rb_entry(nd, struct thread, rb_node);
104 
105 		nd = rb_next(nd);
106 		__machine__remove_thread(machine, t, false);
107 	}
108 	pthread_rwlock_unlock(&machine->threads_lock);
109 }
110 
111 void machine__exit(struct machine *machine)
112 {
113 	map_groups__exit(&machine->kmaps);
114 	dsos__delete(&machine->user_dsos);
115 	dsos__delete(&machine->kernel_dsos);
116 	vdso__exit(machine);
117 	zfree(&machine->root_dir);
118 	zfree(&machine->current_tid);
119 	pthread_rwlock_destroy(&machine->threads_lock);
120 }
121 
122 void machine__delete(struct machine *machine)
123 {
124 	machine__exit(machine);
125 	free(machine);
126 }
127 
128 void machines__init(struct machines *machines)
129 {
130 	machine__init(&machines->host, "", HOST_KERNEL_ID);
131 	machines->guests = RB_ROOT;
132 	machines->symbol_filter = NULL;
133 }
134 
135 void machines__exit(struct machines *machines)
136 {
137 	machine__exit(&machines->host);
138 	/* XXX exit guest */
139 }
140 
141 struct machine *machines__add(struct machines *machines, pid_t pid,
142 			      const char *root_dir)
143 {
144 	struct rb_node **p = &machines->guests.rb_node;
145 	struct rb_node *parent = NULL;
146 	struct machine *pos, *machine = malloc(sizeof(*machine));
147 
148 	if (machine == NULL)
149 		return NULL;
150 
151 	if (machine__init(machine, root_dir, pid) != 0) {
152 		free(machine);
153 		return NULL;
154 	}
155 
156 	machine->symbol_filter = machines->symbol_filter;
157 
158 	while (*p != NULL) {
159 		parent = *p;
160 		pos = rb_entry(parent, struct machine, rb_node);
161 		if (pid < pos->pid)
162 			p = &(*p)->rb_left;
163 		else
164 			p = &(*p)->rb_right;
165 	}
166 
167 	rb_link_node(&machine->rb_node, parent, p);
168 	rb_insert_color(&machine->rb_node, &machines->guests);
169 
170 	return machine;
171 }
172 
173 void machines__set_symbol_filter(struct machines *machines,
174 				 symbol_filter_t symbol_filter)
175 {
176 	struct rb_node *nd;
177 
178 	machines->symbol_filter = symbol_filter;
179 	machines->host.symbol_filter = symbol_filter;
180 
181 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
182 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
183 
184 		machine->symbol_filter = symbol_filter;
185 	}
186 }
187 
188 void machines__set_comm_exec(struct machines *machines, bool comm_exec)
189 {
190 	struct rb_node *nd;
191 
192 	machines->host.comm_exec = comm_exec;
193 
194 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
195 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
196 
197 		machine->comm_exec = comm_exec;
198 	}
199 }
200 
201 struct machine *machines__find(struct machines *machines, pid_t pid)
202 {
203 	struct rb_node **p = &machines->guests.rb_node;
204 	struct rb_node *parent = NULL;
205 	struct machine *machine;
206 	struct machine *default_machine = NULL;
207 
208 	if (pid == HOST_KERNEL_ID)
209 		return &machines->host;
210 
211 	while (*p != NULL) {
212 		parent = *p;
213 		machine = rb_entry(parent, struct machine, rb_node);
214 		if (pid < machine->pid)
215 			p = &(*p)->rb_left;
216 		else if (pid > machine->pid)
217 			p = &(*p)->rb_right;
218 		else
219 			return machine;
220 		if (!machine->pid)
221 			default_machine = machine;
222 	}
223 
224 	return default_machine;
225 }
226 
227 struct machine *machines__findnew(struct machines *machines, pid_t pid)
228 {
229 	char path[PATH_MAX];
230 	const char *root_dir = "";
231 	struct machine *machine = machines__find(machines, pid);
232 
233 	if (machine && (machine->pid == pid))
234 		goto out;
235 
236 	if ((pid != HOST_KERNEL_ID) &&
237 	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
238 	    (symbol_conf.guestmount)) {
239 		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
240 		if (access(path, R_OK)) {
241 			static struct strlist *seen;
242 
243 			if (!seen)
244 				seen = strlist__new(true, NULL);
245 
246 			if (!strlist__has_entry(seen, path)) {
247 				pr_err("Can't access file %s\n", path);
248 				strlist__add(seen, path);
249 			}
250 			machine = NULL;
251 			goto out;
252 		}
253 		root_dir = path;
254 	}
255 
256 	machine = machines__add(machines, pid, root_dir);
257 out:
258 	return machine;
259 }
260 
261 void machines__process_guests(struct machines *machines,
262 			      machine__process_t process, void *data)
263 {
264 	struct rb_node *nd;
265 
266 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
267 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
268 		process(pos, data);
269 	}
270 }
271 
272 char *machine__mmap_name(struct machine *machine, char *bf, size_t size)
273 {
274 	if (machine__is_host(machine))
275 		snprintf(bf, size, "[%s]", "kernel.kallsyms");
276 	else if (machine__is_default_guest(machine))
277 		snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
278 	else {
279 		snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms",
280 			 machine->pid);
281 	}
282 
283 	return bf;
284 }
285 
286 void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size)
287 {
288 	struct rb_node *node;
289 	struct machine *machine;
290 
291 	machines->host.id_hdr_size = id_hdr_size;
292 
293 	for (node = rb_first(&machines->guests); node; node = rb_next(node)) {
294 		machine = rb_entry(node, struct machine, rb_node);
295 		machine->id_hdr_size = id_hdr_size;
296 	}
297 
298 	return;
299 }
300 
301 static void machine__update_thread_pid(struct machine *machine,
302 				       struct thread *th, pid_t pid)
303 {
304 	struct thread *leader;
305 
306 	if (pid == th->pid_ || pid == -1 || th->pid_ != -1)
307 		return;
308 
309 	th->pid_ = pid;
310 
311 	if (th->pid_ == th->tid)
312 		return;
313 
314 	leader = __machine__findnew_thread(machine, th->pid_, th->pid_);
315 	if (!leader)
316 		goto out_err;
317 
318 	if (!leader->mg)
319 		leader->mg = map_groups__new(machine);
320 
321 	if (!leader->mg)
322 		goto out_err;
323 
324 	if (th->mg == leader->mg)
325 		return;
326 
327 	if (th->mg) {
328 		/*
329 		 * Maps are created from MMAP events which provide the pid and
330 		 * tid.  Consequently there never should be any maps on a thread
331 		 * with an unknown pid.  Just print an error if there are.
332 		 */
333 		if (!map_groups__empty(th->mg))
334 			pr_err("Discarding thread maps for %d:%d\n",
335 			       th->pid_, th->tid);
336 		map_groups__put(th->mg);
337 	}
338 
339 	th->mg = map_groups__get(leader->mg);
340 
341 	return;
342 
343 out_err:
344 	pr_err("Failed to join map groups for %d:%d\n", th->pid_, th->tid);
345 }
346 
347 static struct thread *____machine__findnew_thread(struct machine *machine,
348 						  pid_t pid, pid_t tid,
349 						  bool create)
350 {
351 	struct rb_node **p = &machine->threads.rb_node;
352 	struct rb_node *parent = NULL;
353 	struct thread *th;
354 
355 	/*
356 	 * Front-end cache - TID lookups come in blocks,
357 	 * so most of the time we dont have to look up
358 	 * the full rbtree:
359 	 */
360 	th = machine->last_match;
361 	if (th != NULL) {
362 		if (th->tid == tid) {
363 			machine__update_thread_pid(machine, th, pid);
364 			return th;
365 		}
366 
367 		machine->last_match = NULL;
368 	}
369 
370 	while (*p != NULL) {
371 		parent = *p;
372 		th = rb_entry(parent, struct thread, rb_node);
373 
374 		if (th->tid == tid) {
375 			machine->last_match = th;
376 			machine__update_thread_pid(machine, th, pid);
377 			return th;
378 		}
379 
380 		if (tid < th->tid)
381 			p = &(*p)->rb_left;
382 		else
383 			p = &(*p)->rb_right;
384 	}
385 
386 	if (!create)
387 		return NULL;
388 
389 	th = thread__new(pid, tid);
390 	if (th != NULL) {
391 		rb_link_node(&th->rb_node, parent, p);
392 		rb_insert_color(&th->rb_node, &machine->threads);
393 
394 		/*
395 		 * We have to initialize map_groups separately
396 		 * after rb tree is updated.
397 		 *
398 		 * The reason is that we call machine__findnew_thread
399 		 * within thread__init_map_groups to find the thread
400 		 * leader and that would screwed the rb tree.
401 		 */
402 		if (thread__init_map_groups(th, machine)) {
403 			rb_erase(&th->rb_node, &machine->threads);
404 			RB_CLEAR_NODE(&th->rb_node);
405 			thread__delete(th);
406 			return NULL;
407 		}
408 		/*
409 		 * It is now in the rbtree, get a ref
410 		 */
411 		thread__get(th);
412 		machine->last_match = th;
413 	}
414 
415 	return th;
416 }
417 
418 struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
419 {
420 	return ____machine__findnew_thread(machine, pid, tid, true);
421 }
422 
423 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
424 				       pid_t tid)
425 {
426 	struct thread *th;
427 
428 	pthread_rwlock_wrlock(&machine->threads_lock);
429 	th = thread__get(__machine__findnew_thread(machine, pid, tid));
430 	pthread_rwlock_unlock(&machine->threads_lock);
431 	return th;
432 }
433 
434 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
435 				    pid_t tid)
436 {
437 	struct thread *th;
438 	pthread_rwlock_rdlock(&machine->threads_lock);
439 	th =  thread__get(____machine__findnew_thread(machine, pid, tid, false));
440 	pthread_rwlock_unlock(&machine->threads_lock);
441 	return th;
442 }
443 
444 struct comm *machine__thread_exec_comm(struct machine *machine,
445 				       struct thread *thread)
446 {
447 	if (machine->comm_exec)
448 		return thread__exec_comm(thread);
449 	else
450 		return thread__comm(thread);
451 }
452 
453 int machine__process_comm_event(struct machine *machine, union perf_event *event,
454 				struct perf_sample *sample)
455 {
456 	struct thread *thread = machine__findnew_thread(machine,
457 							event->comm.pid,
458 							event->comm.tid);
459 	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;
460 	int err = 0;
461 
462 	if (exec)
463 		machine->comm_exec = true;
464 
465 	if (dump_trace)
466 		perf_event__fprintf_comm(event, stdout);
467 
468 	if (thread == NULL ||
469 	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {
470 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
471 		err = -1;
472 	}
473 
474 	thread__put(thread);
475 
476 	return err;
477 }
478 
479 int machine__process_lost_event(struct machine *machine __maybe_unused,
480 				union perf_event *event, struct perf_sample *sample __maybe_unused)
481 {
482 	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
483 		    event->lost.id, event->lost.lost);
484 	return 0;
485 }
486 
487 static struct dso*
488 machine__module_dso(struct machine *machine, struct kmod_path *m,
489 		    const char *filename)
490 {
491 	struct dso *dso;
492 
493 	dso = dsos__find(&machine->kernel_dsos, m->name, true);
494 	if (!dso) {
495 		dso = dsos__addnew(&machine->kernel_dsos, m->name);
496 		if (dso == NULL)
497 			return NULL;
498 
499 		if (machine__is_host(machine))
500 			dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
501 		else
502 			dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;
503 
504 		/* _KMODULE_COMP should be next to _KMODULE */
505 		if (m->kmod && m->comp)
506 			dso->symtab_type++;
507 
508 		dso__set_short_name(dso, strdup(m->name), true);
509 		dso__set_long_name(dso, strdup(filename), true);
510 	}
511 
512 	return dso;
513 }
514 
515 int machine__process_aux_event(struct machine *machine __maybe_unused,
516 			       union perf_event *event)
517 {
518 	if (dump_trace)
519 		perf_event__fprintf_aux(event, stdout);
520 	return 0;
521 }
522 
523 int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
524 					union perf_event *event)
525 {
526 	if (dump_trace)
527 		perf_event__fprintf_itrace_start(event, stdout);
528 	return 0;
529 }
530 
531 struct map *machine__new_module(struct machine *machine, u64 start,
532 				const char *filename)
533 {
534 	struct map *map = NULL;
535 	struct dso *dso;
536 	struct kmod_path m;
537 
538 	if (kmod_path__parse_name(&m, filename))
539 		return NULL;
540 
541 	map = map_groups__find_by_name(&machine->kmaps, MAP__FUNCTION,
542 				       m.name);
543 	if (map)
544 		goto out;
545 
546 	dso = machine__module_dso(machine, &m, filename);
547 	if (dso == NULL)
548 		goto out;
549 
550 	map = map__new2(start, dso, MAP__FUNCTION);
551 	if (map == NULL)
552 		goto out;
553 
554 	map_groups__insert(&machine->kmaps, map);
555 
556 out:
557 	free(m.name);
558 	return map;
559 }
560 
561 size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
562 {
563 	struct rb_node *nd;
564 	size_t ret = __dsos__fprintf(&machines->host.kernel_dsos.head, fp) +
565 		     __dsos__fprintf(&machines->host.user_dsos.head, fp);
566 
567 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
568 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
569 		ret += __dsos__fprintf(&pos->kernel_dsos.head, fp);
570 		ret += __dsos__fprintf(&pos->user_dsos.head, fp);
571 	}
572 
573 	return ret;
574 }
575 
576 size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,
577 				     bool (skip)(struct dso *dso, int parm), int parm)
578 {
579 	return __dsos__fprintf_buildid(&m->kernel_dsos.head, fp, skip, parm) +
580 	       __dsos__fprintf_buildid(&m->user_dsos.head, fp, skip, parm);
581 }
582 
583 size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,
584 				     bool (skip)(struct dso *dso, int parm), int parm)
585 {
586 	struct rb_node *nd;
587 	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);
588 
589 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
590 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
591 		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
592 	}
593 	return ret;
594 }
595 
596 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
597 {
598 	int i;
599 	size_t printed = 0;
600 	struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
601 
602 	if (kdso->has_build_id) {
603 		char filename[PATH_MAX];
604 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
605 			printed += fprintf(fp, "[0] %s\n", filename);
606 	}
607 
608 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
609 		printed += fprintf(fp, "[%d] %s\n",
610 				   i + kdso->has_build_id, vmlinux_path[i]);
611 
612 	return printed;
613 }
614 
615 size_t machine__fprintf(struct machine *machine, FILE *fp)
616 {
617 	size_t ret = 0;
618 	struct rb_node *nd;
619 
620 	pthread_rwlock_rdlock(&machine->threads_lock);
621 
622 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
623 		struct thread *pos = rb_entry(nd, struct thread, rb_node);
624 
625 		ret += thread__fprintf(pos, fp);
626 	}
627 
628 	pthread_rwlock_unlock(&machine->threads_lock);
629 
630 	return ret;
631 }
632 
633 static struct dso *machine__get_kernel(struct machine *machine)
634 {
635 	const char *vmlinux_name = NULL;
636 	struct dso *kernel;
637 
638 	if (machine__is_host(machine)) {
639 		vmlinux_name = symbol_conf.vmlinux_name;
640 		if (!vmlinux_name)
641 			vmlinux_name = "[kernel.kallsyms]";
642 
643 		kernel = dso__kernel_findnew(machine, vmlinux_name,
644 					     "[kernel]",
645 					     DSO_TYPE_KERNEL);
646 	} else {
647 		char bf[PATH_MAX];
648 
649 		if (machine__is_default_guest(machine))
650 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
651 		if (!vmlinux_name)
652 			vmlinux_name = machine__mmap_name(machine, bf,
653 							  sizeof(bf));
654 
655 		kernel = dso__kernel_findnew(machine, vmlinux_name,
656 					     "[guest.kernel]",
657 					     DSO_TYPE_GUEST_KERNEL);
658 	}
659 
660 	if (kernel != NULL && (!kernel->has_build_id))
661 		dso__read_running_kernel_build_id(kernel, machine);
662 
663 	return kernel;
664 }
665 
666 struct process_args {
667 	u64 start;
668 };
669 
670 static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
671 					   size_t bufsz)
672 {
673 	if (machine__is_default_guest(machine))
674 		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
675 	else
676 		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
677 }
678 
679 const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
680 
681 /* Figure out the start address of kernel map from /proc/kallsyms.
682  * Returns the name of the start symbol in *symbol_name. Pass in NULL as
683  * symbol_name if it's not that important.
684  */
685 static u64 machine__get_running_kernel_start(struct machine *machine,
686 					     const char **symbol_name)
687 {
688 	char filename[PATH_MAX];
689 	int i;
690 	const char *name;
691 	u64 addr = 0;
692 
693 	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
694 
695 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
696 		return 0;
697 
698 	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
699 		addr = kallsyms__get_function_start(filename, name);
700 		if (addr)
701 			break;
702 	}
703 
704 	if (symbol_name)
705 		*symbol_name = name;
706 
707 	return addr;
708 }
709 
710 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
711 {
712 	enum map_type type;
713 	u64 start = machine__get_running_kernel_start(machine, NULL);
714 
715 	for (type = 0; type < MAP__NR_TYPES; ++type) {
716 		struct kmap *kmap;
717 
718 		machine->vmlinux_maps[type] = map__new2(start, kernel, type);
719 		if (machine->vmlinux_maps[type] == NULL)
720 			return -1;
721 
722 		machine->vmlinux_maps[type]->map_ip =
723 			machine->vmlinux_maps[type]->unmap_ip =
724 				identity__map_ip;
725 		kmap = map__kmap(machine->vmlinux_maps[type]);
726 		if (!kmap)
727 			return -1;
728 
729 		kmap->kmaps = &machine->kmaps;
730 		map_groups__insert(&machine->kmaps,
731 				   machine->vmlinux_maps[type]);
732 	}
733 
734 	return 0;
735 }
736 
737 void machine__destroy_kernel_maps(struct machine *machine)
738 {
739 	enum map_type type;
740 
741 	for (type = 0; type < MAP__NR_TYPES; ++type) {
742 		struct kmap *kmap;
743 
744 		if (machine->vmlinux_maps[type] == NULL)
745 			continue;
746 
747 		kmap = map__kmap(machine->vmlinux_maps[type]);
748 		map_groups__remove(&machine->kmaps,
749 				   machine->vmlinux_maps[type]);
750 		if (kmap && kmap->ref_reloc_sym) {
751 			/*
752 			 * ref_reloc_sym is shared among all maps, so free just
753 			 * on one of them.
754 			 */
755 			if (type == MAP__FUNCTION) {
756 				zfree((char **)&kmap->ref_reloc_sym->name);
757 				zfree(&kmap->ref_reloc_sym);
758 			} else
759 				kmap->ref_reloc_sym = NULL;
760 		}
761 
762 		map__delete(machine->vmlinux_maps[type]);
763 		machine->vmlinux_maps[type] = NULL;
764 	}
765 }
766 
767 int machines__create_guest_kernel_maps(struct machines *machines)
768 {
769 	int ret = 0;
770 	struct dirent **namelist = NULL;
771 	int i, items = 0;
772 	char path[PATH_MAX];
773 	pid_t pid;
774 	char *endp;
775 
776 	if (symbol_conf.default_guest_vmlinux_name ||
777 	    symbol_conf.default_guest_modules ||
778 	    symbol_conf.default_guest_kallsyms) {
779 		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
780 	}
781 
782 	if (symbol_conf.guestmount) {
783 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
784 		if (items <= 0)
785 			return -ENOENT;
786 		for (i = 0; i < items; i++) {
787 			if (!isdigit(namelist[i]->d_name[0])) {
788 				/* Filter out . and .. */
789 				continue;
790 			}
791 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
792 			if ((*endp != '\0') ||
793 			    (endp == namelist[i]->d_name) ||
794 			    (errno == ERANGE)) {
795 				pr_debug("invalid directory (%s). Skipping.\n",
796 					 namelist[i]->d_name);
797 				continue;
798 			}
799 			sprintf(path, "%s/%s/proc/kallsyms",
800 				symbol_conf.guestmount,
801 				namelist[i]->d_name);
802 			ret = access(path, R_OK);
803 			if (ret) {
804 				pr_debug("Can't access file %s\n", path);
805 				goto failure;
806 			}
807 			machines__create_kernel_maps(machines, pid);
808 		}
809 failure:
810 		free(namelist);
811 	}
812 
813 	return ret;
814 }
815 
816 void machines__destroy_kernel_maps(struct machines *machines)
817 {
818 	struct rb_node *next = rb_first(&machines->guests);
819 
820 	machine__destroy_kernel_maps(&machines->host);
821 
822 	while (next) {
823 		struct machine *pos = rb_entry(next, struct machine, rb_node);
824 
825 		next = rb_next(&pos->rb_node);
826 		rb_erase(&pos->rb_node, &machines->guests);
827 		machine__delete(pos);
828 	}
829 }
830 
831 int machines__create_kernel_maps(struct machines *machines, pid_t pid)
832 {
833 	struct machine *machine = machines__findnew(machines, pid);
834 
835 	if (machine == NULL)
836 		return -1;
837 
838 	return machine__create_kernel_maps(machine);
839 }
840 
841 int machine__load_kallsyms(struct machine *machine, const char *filename,
842 			   enum map_type type, symbol_filter_t filter)
843 {
844 	struct map *map = machine->vmlinux_maps[type];
845 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
846 
847 	if (ret > 0) {
848 		dso__set_loaded(map->dso, type);
849 		/*
850 		 * Since /proc/kallsyms will have multiple sessions for the
851 		 * kernel, with modules between them, fixup the end of all
852 		 * sections.
853 		 */
854 		__map_groups__fixup_end(&machine->kmaps, type);
855 	}
856 
857 	return ret;
858 }
859 
860 int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
861 			       symbol_filter_t filter)
862 {
863 	struct map *map = machine->vmlinux_maps[type];
864 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
865 
866 	if (ret > 0)
867 		dso__set_loaded(map->dso, type);
868 
869 	return ret;
870 }
871 
872 static void map_groups__fixup_end(struct map_groups *mg)
873 {
874 	int i;
875 	for (i = 0; i < MAP__NR_TYPES; ++i)
876 		__map_groups__fixup_end(mg, i);
877 }
878 
879 static char *get_kernel_version(const char *root_dir)
880 {
881 	char version[PATH_MAX];
882 	FILE *file;
883 	char *name, *tmp;
884 	const char *prefix = "Linux version ";
885 
886 	sprintf(version, "%s/proc/version", root_dir);
887 	file = fopen(version, "r");
888 	if (!file)
889 		return NULL;
890 
891 	version[0] = '\0';
892 	tmp = fgets(version, sizeof(version), file);
893 	fclose(file);
894 
895 	name = strstr(version, prefix);
896 	if (!name)
897 		return NULL;
898 	name += strlen(prefix);
899 	tmp = strchr(name, ' ');
900 	if (tmp)
901 		*tmp = '\0';
902 
903 	return strdup(name);
904 }
905 
906 static bool is_kmod_dso(struct dso *dso)
907 {
908 	return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
909 	       dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
910 }
911 
912 static int map_groups__set_module_path(struct map_groups *mg, const char *path,
913 				       struct kmod_path *m)
914 {
915 	struct map *map;
916 	char *long_name;
917 
918 	map = map_groups__find_by_name(mg, MAP__FUNCTION, m->name);
919 	if (map == NULL)
920 		return 0;
921 
922 	long_name = strdup(path);
923 	if (long_name == NULL)
924 		return -ENOMEM;
925 
926 	dso__set_long_name(map->dso, long_name, true);
927 	dso__kernel_module_get_build_id(map->dso, "");
928 
929 	/*
930 	 * Full name could reveal us kmod compression, so
931 	 * we need to update the symtab_type if needed.
932 	 */
933 	if (m->comp && is_kmod_dso(map->dso))
934 		map->dso->symtab_type++;
935 
936 	return 0;
937 }
938 
939 static int map_groups__set_modules_path_dir(struct map_groups *mg,
940 				const char *dir_name, int depth)
941 {
942 	struct dirent *dent;
943 	DIR *dir = opendir(dir_name);
944 	int ret = 0;
945 
946 	if (!dir) {
947 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
948 		return -1;
949 	}
950 
951 	while ((dent = readdir(dir)) != NULL) {
952 		char path[PATH_MAX];
953 		struct stat st;
954 
955 		/*sshfs might return bad dent->d_type, so we have to stat*/
956 		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
957 		if (stat(path, &st))
958 			continue;
959 
960 		if (S_ISDIR(st.st_mode)) {
961 			if (!strcmp(dent->d_name, ".") ||
962 			    !strcmp(dent->d_name, ".."))
963 				continue;
964 
965 			/* Do not follow top-level source and build symlinks */
966 			if (depth == 0) {
967 				if (!strcmp(dent->d_name, "source") ||
968 				    !strcmp(dent->d_name, "build"))
969 					continue;
970 			}
971 
972 			ret = map_groups__set_modules_path_dir(mg, path,
973 							       depth + 1);
974 			if (ret < 0)
975 				goto out;
976 		} else {
977 			struct kmod_path m;
978 
979 			ret = kmod_path__parse_name(&m, dent->d_name);
980 			if (ret)
981 				goto out;
982 
983 			if (m.kmod)
984 				ret = map_groups__set_module_path(mg, path, &m);
985 
986 			free(m.name);
987 
988 			if (ret)
989 				goto out;
990 		}
991 	}
992 
993 out:
994 	closedir(dir);
995 	return ret;
996 }
997 
998 static int machine__set_modules_path(struct machine *machine)
999 {
1000 	char *version;
1001 	char modules_path[PATH_MAX];
1002 
1003 	version = get_kernel_version(machine->root_dir);
1004 	if (!version)
1005 		return -1;
1006 
1007 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",
1008 		 machine->root_dir, version);
1009 	free(version);
1010 
1011 	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0);
1012 }
1013 
1014 static int machine__create_module(void *arg, const char *name, u64 start)
1015 {
1016 	struct machine *machine = arg;
1017 	struct map *map;
1018 
1019 	map = machine__new_module(machine, start, name);
1020 	if (map == NULL)
1021 		return -1;
1022 
1023 	dso__kernel_module_get_build_id(map->dso, machine->root_dir);
1024 
1025 	return 0;
1026 }
1027 
1028 static int machine__create_modules(struct machine *machine)
1029 {
1030 	const char *modules;
1031 	char path[PATH_MAX];
1032 
1033 	if (machine__is_default_guest(machine)) {
1034 		modules = symbol_conf.default_guest_modules;
1035 	} else {
1036 		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);
1037 		modules = path;
1038 	}
1039 
1040 	if (symbol__restricted_filename(modules, "/proc/modules"))
1041 		return -1;
1042 
1043 	if (modules__parse(modules, machine, machine__create_module))
1044 		return -1;
1045 
1046 	if (!machine__set_modules_path(machine))
1047 		return 0;
1048 
1049 	pr_debug("Problems setting modules path maps, continuing anyway...\n");
1050 
1051 	return 0;
1052 }
1053 
1054 int machine__create_kernel_maps(struct machine *machine)
1055 {
1056 	struct dso *kernel = machine__get_kernel(machine);
1057 	const char *name;
1058 	u64 addr = machine__get_running_kernel_start(machine, &name);
1059 	if (!addr)
1060 		return -1;
1061 
1062 	if (kernel == NULL ||
1063 	    __machine__create_kernel_maps(machine, kernel) < 0)
1064 		return -1;
1065 
1066 	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
1067 		if (machine__is_host(machine))
1068 			pr_debug("Problems creating module maps, "
1069 				 "continuing anyway...\n");
1070 		else
1071 			pr_debug("Problems creating module maps for guest %d, "
1072 				 "continuing anyway...\n", machine->pid);
1073 	}
1074 
1075 	/*
1076 	 * Now that we have all the maps created, just set the ->end of them:
1077 	 */
1078 	map_groups__fixup_end(&machine->kmaps);
1079 
1080 	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
1081 					     addr)) {
1082 		machine__destroy_kernel_maps(machine);
1083 		return -1;
1084 	}
1085 
1086 	return 0;
1087 }
1088 
1089 static void machine__set_kernel_mmap_len(struct machine *machine,
1090 					 union perf_event *event)
1091 {
1092 	int i;
1093 
1094 	for (i = 0; i < MAP__NR_TYPES; i++) {
1095 		machine->vmlinux_maps[i]->start = event->mmap.start;
1096 		machine->vmlinux_maps[i]->end   = (event->mmap.start +
1097 						   event->mmap.len);
1098 		/*
1099 		 * Be a bit paranoid here, some perf.data file came with
1100 		 * a zero sized synthesized MMAP event for the kernel.
1101 		 */
1102 		if (machine->vmlinux_maps[i]->end == 0)
1103 			machine->vmlinux_maps[i]->end = ~0ULL;
1104 	}
1105 }
1106 
1107 static bool machine__uses_kcore(struct machine *machine)
1108 {
1109 	struct dso *dso;
1110 
1111 	list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1112 		if (dso__is_kcore(dso))
1113 			return true;
1114 	}
1115 
1116 	return false;
1117 }
1118 
1119 static int machine__process_kernel_mmap_event(struct machine *machine,
1120 					      union perf_event *event)
1121 {
1122 	struct map *map;
1123 	char kmmap_prefix[PATH_MAX];
1124 	enum dso_kernel_type kernel_type;
1125 	bool is_kernel_mmap;
1126 
1127 	/* If we have maps from kcore then we do not need or want any others */
1128 	if (machine__uses_kcore(machine))
1129 		return 0;
1130 
1131 	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
1132 	if (machine__is_host(machine))
1133 		kernel_type = DSO_TYPE_KERNEL;
1134 	else
1135 		kernel_type = DSO_TYPE_GUEST_KERNEL;
1136 
1137 	is_kernel_mmap = memcmp(event->mmap.filename,
1138 				kmmap_prefix,
1139 				strlen(kmmap_prefix) - 1) == 0;
1140 	if (event->mmap.filename[0] == '/' ||
1141 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
1142 		map = machine__new_module(machine, event->mmap.start,
1143 					  event->mmap.filename);
1144 		if (map == NULL)
1145 			goto out_problem;
1146 
1147 		map->end = map->start + event->mmap.len;
1148 	} else if (is_kernel_mmap) {
1149 		const char *symbol_name = (event->mmap.filename +
1150 				strlen(kmmap_prefix));
1151 		/*
1152 		 * Should be there already, from the build-id table in
1153 		 * the header.
1154 		 */
1155 		struct dso *kernel = NULL;
1156 		struct dso *dso;
1157 
1158 		list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1159 			if (is_kernel_module(dso->long_name))
1160 				continue;
1161 
1162 			kernel = dso;
1163 			break;
1164 		}
1165 
1166 		if (kernel == NULL)
1167 			kernel = __dsos__findnew(&machine->kernel_dsos,
1168 						 kmmap_prefix);
1169 		if (kernel == NULL)
1170 			goto out_problem;
1171 
1172 		kernel->kernel = kernel_type;
1173 		if (__machine__create_kernel_maps(machine, kernel) < 0)
1174 			goto out_problem;
1175 
1176 		if (strstr(kernel->long_name, "vmlinux"))
1177 			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
1178 
1179 		machine__set_kernel_mmap_len(machine, event);
1180 
1181 		/*
1182 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
1183 		 * symbol. Effectively having zero here means that at record
1184 		 * time /proc/sys/kernel/kptr_restrict was non zero.
1185 		 */
1186 		if (event->mmap.pgoff != 0) {
1187 			maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
1188 							 symbol_name,
1189 							 event->mmap.pgoff);
1190 		}
1191 
1192 		if (machine__is_default_guest(machine)) {
1193 			/*
1194 			 * preload dso of guest kernel and modules
1195 			 */
1196 			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
1197 				  NULL);
1198 		}
1199 	}
1200 	return 0;
1201 out_problem:
1202 	return -1;
1203 }
1204 
1205 int machine__process_mmap2_event(struct machine *machine,
1206 				 union perf_event *event,
1207 				 struct perf_sample *sample __maybe_unused)
1208 {
1209 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1210 	struct thread *thread;
1211 	struct map *map;
1212 	enum map_type type;
1213 	int ret = 0;
1214 
1215 	if (dump_trace)
1216 		perf_event__fprintf_mmap2(event, stdout);
1217 
1218 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1219 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1220 		ret = machine__process_kernel_mmap_event(machine, event);
1221 		if (ret < 0)
1222 			goto out_problem;
1223 		return 0;
1224 	}
1225 
1226 	thread = machine__findnew_thread(machine, event->mmap2.pid,
1227 					event->mmap2.tid);
1228 	if (thread == NULL)
1229 		goto out_problem;
1230 
1231 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1232 		type = MAP__VARIABLE;
1233 	else
1234 		type = MAP__FUNCTION;
1235 
1236 	map = map__new(machine, event->mmap2.start,
1237 			event->mmap2.len, event->mmap2.pgoff,
1238 			event->mmap2.pid, event->mmap2.maj,
1239 			event->mmap2.min, event->mmap2.ino,
1240 			event->mmap2.ino_generation,
1241 			event->mmap2.prot,
1242 			event->mmap2.flags,
1243 			event->mmap2.filename, type, thread);
1244 
1245 	if (map == NULL)
1246 		goto out_problem_map;
1247 
1248 	thread__insert_map(thread, map);
1249 	thread__put(thread);
1250 	return 0;
1251 
1252 out_problem_map:
1253 	thread__put(thread);
1254 out_problem:
1255 	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
1256 	return 0;
1257 }
1258 
1259 int machine__process_mmap_event(struct machine *machine, union perf_event *event,
1260 				struct perf_sample *sample __maybe_unused)
1261 {
1262 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1263 	struct thread *thread;
1264 	struct map *map;
1265 	enum map_type type;
1266 	int ret = 0;
1267 
1268 	if (dump_trace)
1269 		perf_event__fprintf_mmap(event, stdout);
1270 
1271 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1272 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1273 		ret = machine__process_kernel_mmap_event(machine, event);
1274 		if (ret < 0)
1275 			goto out_problem;
1276 		return 0;
1277 	}
1278 
1279 	thread = machine__findnew_thread(machine, event->mmap.pid,
1280 					 event->mmap.tid);
1281 	if (thread == NULL)
1282 		goto out_problem;
1283 
1284 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1285 		type = MAP__VARIABLE;
1286 	else
1287 		type = MAP__FUNCTION;
1288 
1289 	map = map__new(machine, event->mmap.start,
1290 			event->mmap.len, event->mmap.pgoff,
1291 			event->mmap.pid, 0, 0, 0, 0, 0, 0,
1292 			event->mmap.filename,
1293 			type, thread);
1294 
1295 	if (map == NULL)
1296 		goto out_problem_map;
1297 
1298 	thread__insert_map(thread, map);
1299 	thread__put(thread);
1300 	return 0;
1301 
1302 out_problem_map:
1303 	thread__put(thread);
1304 out_problem:
1305 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
1306 	return 0;
1307 }
1308 
1309 static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock)
1310 {
1311 	if (machine->last_match == th)
1312 		machine->last_match = NULL;
1313 
1314 	BUG_ON(atomic_read(&th->refcnt) == 0);
1315 	if (lock)
1316 		pthread_rwlock_wrlock(&machine->threads_lock);
1317 	rb_erase(&th->rb_node, &machine->threads);
1318 	RB_CLEAR_NODE(&th->rb_node);
1319 	/*
1320 	 * Move it first to the dead_threads list, then drop the reference,
1321 	 * if this is the last reference, then the thread__delete destructor
1322 	 * will be called and we will remove it from the dead_threads list.
1323 	 */
1324 	list_add_tail(&th->node, &machine->dead_threads);
1325 	if (lock)
1326 		pthread_rwlock_unlock(&machine->threads_lock);
1327 	thread__put(th);
1328 }
1329 
1330 void machine__remove_thread(struct machine *machine, struct thread *th)
1331 {
1332 	return __machine__remove_thread(machine, th, true);
1333 }
1334 
1335 int machine__process_fork_event(struct machine *machine, union perf_event *event,
1336 				struct perf_sample *sample)
1337 {
1338 	struct thread *thread = machine__find_thread(machine,
1339 						     event->fork.pid,
1340 						     event->fork.tid);
1341 	struct thread *parent = machine__findnew_thread(machine,
1342 							event->fork.ppid,
1343 							event->fork.ptid);
1344 	int err = 0;
1345 
1346 	/* if a thread currently exists for the thread id remove it */
1347 	if (thread != NULL) {
1348 		machine__remove_thread(machine, thread);
1349 		thread__put(thread);
1350 	}
1351 
1352 	thread = machine__findnew_thread(machine, event->fork.pid,
1353 					 event->fork.tid);
1354 	if (dump_trace)
1355 		perf_event__fprintf_task(event, stdout);
1356 
1357 	if (thread == NULL || parent == NULL ||
1358 	    thread__fork(thread, parent, sample->time) < 0) {
1359 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
1360 		err = -1;
1361 	}
1362 	thread__put(thread);
1363 	thread__put(parent);
1364 
1365 	return err;
1366 }
1367 
1368 int machine__process_exit_event(struct machine *machine, union perf_event *event,
1369 				struct perf_sample *sample __maybe_unused)
1370 {
1371 	struct thread *thread = machine__find_thread(machine,
1372 						     event->fork.pid,
1373 						     event->fork.tid);
1374 
1375 	if (dump_trace)
1376 		perf_event__fprintf_task(event, stdout);
1377 
1378 	if (thread != NULL) {
1379 		thread__exited(thread);
1380 		thread__put(thread);
1381 	}
1382 
1383 	return 0;
1384 }
1385 
1386 int machine__process_event(struct machine *machine, union perf_event *event,
1387 			   struct perf_sample *sample)
1388 {
1389 	int ret;
1390 
1391 	switch (event->header.type) {
1392 	case PERF_RECORD_COMM:
1393 		ret = machine__process_comm_event(machine, event, sample); break;
1394 	case PERF_RECORD_MMAP:
1395 		ret = machine__process_mmap_event(machine, event, sample); break;
1396 	case PERF_RECORD_MMAP2:
1397 		ret = machine__process_mmap2_event(machine, event, sample); break;
1398 	case PERF_RECORD_FORK:
1399 		ret = machine__process_fork_event(machine, event, sample); break;
1400 	case PERF_RECORD_EXIT:
1401 		ret = machine__process_exit_event(machine, event, sample); break;
1402 	case PERF_RECORD_LOST:
1403 		ret = machine__process_lost_event(machine, event, sample); break;
1404 	case PERF_RECORD_AUX:
1405 		ret = machine__process_aux_event(machine, event); break;
1406 	case PERF_RECORD_ITRACE_START:
1407 		ret = machine__process_itrace_start_event(machine, event);
1408 		break;
1409 	default:
1410 		ret = -1;
1411 		break;
1412 	}
1413 
1414 	return ret;
1415 }
1416 
1417 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
1418 {
1419 	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
1420 		return 1;
1421 	return 0;
1422 }
1423 
1424 static void ip__resolve_ams(struct thread *thread,
1425 			    struct addr_map_symbol *ams,
1426 			    u64 ip)
1427 {
1428 	struct addr_location al;
1429 
1430 	memset(&al, 0, sizeof(al));
1431 	/*
1432 	 * We cannot use the header.misc hint to determine whether a
1433 	 * branch stack address is user, kernel, guest, hypervisor.
1434 	 * Branches may straddle the kernel/user/hypervisor boundaries.
1435 	 * Thus, we have to try consecutively until we find a match
1436 	 * or else, the symbol is unknown
1437 	 */
1438 	thread__find_cpumode_addr_location(thread, MAP__FUNCTION, ip, &al);
1439 
1440 	ams->addr = ip;
1441 	ams->al_addr = al.addr;
1442 	ams->sym = al.sym;
1443 	ams->map = al.map;
1444 }
1445 
1446 static void ip__resolve_data(struct thread *thread,
1447 			     u8 m, struct addr_map_symbol *ams, u64 addr)
1448 {
1449 	struct addr_location al;
1450 
1451 	memset(&al, 0, sizeof(al));
1452 
1453 	thread__find_addr_location(thread, m, MAP__VARIABLE, addr, &al);
1454 	if (al.map == NULL) {
1455 		/*
1456 		 * some shared data regions have execute bit set which puts
1457 		 * their mapping in the MAP__FUNCTION type array.
1458 		 * Check there as a fallback option before dropping the sample.
1459 		 */
1460 		thread__find_addr_location(thread, m, MAP__FUNCTION, addr, &al);
1461 	}
1462 
1463 	ams->addr = addr;
1464 	ams->al_addr = al.addr;
1465 	ams->sym = al.sym;
1466 	ams->map = al.map;
1467 }
1468 
1469 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
1470 				     struct addr_location *al)
1471 {
1472 	struct mem_info *mi = zalloc(sizeof(*mi));
1473 
1474 	if (!mi)
1475 		return NULL;
1476 
1477 	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
1478 	ip__resolve_data(al->thread, al->cpumode, &mi->daddr, sample->addr);
1479 	mi->data_src.val = sample->data_src;
1480 
1481 	return mi;
1482 }
1483 
1484 static int add_callchain_ip(struct thread *thread,
1485 			    struct symbol **parent,
1486 			    struct addr_location *root_al,
1487 			    u8 *cpumode,
1488 			    u64 ip)
1489 {
1490 	struct addr_location al;
1491 
1492 	al.filtered = 0;
1493 	al.sym = NULL;
1494 	if (!cpumode) {
1495 		thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
1496 						   ip, &al);
1497 	} else {
1498 		if (ip >= PERF_CONTEXT_MAX) {
1499 			switch (ip) {
1500 			case PERF_CONTEXT_HV:
1501 				*cpumode = PERF_RECORD_MISC_HYPERVISOR;
1502 				break;
1503 			case PERF_CONTEXT_KERNEL:
1504 				*cpumode = PERF_RECORD_MISC_KERNEL;
1505 				break;
1506 			case PERF_CONTEXT_USER:
1507 				*cpumode = PERF_RECORD_MISC_USER;
1508 				break;
1509 			default:
1510 				pr_debug("invalid callchain context: "
1511 					 "%"PRId64"\n", (s64) ip);
1512 				/*
1513 				 * It seems the callchain is corrupted.
1514 				 * Discard all.
1515 				 */
1516 				callchain_cursor_reset(&callchain_cursor);
1517 				return 1;
1518 			}
1519 			return 0;
1520 		}
1521 		thread__find_addr_location(thread, *cpumode, MAP__FUNCTION,
1522 					   ip, &al);
1523 	}
1524 
1525 	if (al.sym != NULL) {
1526 		if (sort__has_parent && !*parent &&
1527 		    symbol__match_regex(al.sym, &parent_regex))
1528 			*parent = al.sym;
1529 		else if (have_ignore_callees && root_al &&
1530 		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
1531 			/* Treat this symbol as the root,
1532 			   forgetting its callees. */
1533 			*root_al = al;
1534 			callchain_cursor_reset(&callchain_cursor);
1535 		}
1536 	}
1537 
1538 	return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);
1539 }
1540 
1541 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
1542 					   struct addr_location *al)
1543 {
1544 	unsigned int i;
1545 	const struct branch_stack *bs = sample->branch_stack;
1546 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
1547 
1548 	if (!bi)
1549 		return NULL;
1550 
1551 	for (i = 0; i < bs->nr; i++) {
1552 		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
1553 		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
1554 		bi[i].flags = bs->entries[i].flags;
1555 	}
1556 	return bi;
1557 }
1558 
1559 #define CHASHSZ 127
1560 #define CHASHBITS 7
1561 #define NO_ENTRY 0xff
1562 
1563 #define PERF_MAX_BRANCH_DEPTH 127
1564 
1565 /* Remove loops. */
1566 static int remove_loops(struct branch_entry *l, int nr)
1567 {
1568 	int i, j, off;
1569 	unsigned char chash[CHASHSZ];
1570 
1571 	memset(chash, NO_ENTRY, sizeof(chash));
1572 
1573 	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
1574 
1575 	for (i = 0; i < nr; i++) {
1576 		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
1577 
1578 		/* no collision handling for now */
1579 		if (chash[h] == NO_ENTRY) {
1580 			chash[h] = i;
1581 		} else if (l[chash[h]].from == l[i].from) {
1582 			bool is_loop = true;
1583 			/* check if it is a real loop */
1584 			off = 0;
1585 			for (j = chash[h]; j < i && i + off < nr; j++, off++)
1586 				if (l[j].from != l[i + off].from) {
1587 					is_loop = false;
1588 					break;
1589 				}
1590 			if (is_loop) {
1591 				memmove(l + i, l + i + off,
1592 					(nr - (i + off)) * sizeof(*l));
1593 				nr -= off;
1594 			}
1595 		}
1596 	}
1597 	return nr;
1598 }
1599 
1600 /*
1601  * Recolve LBR callstack chain sample
1602  * Return:
1603  * 1 on success get LBR callchain information
1604  * 0 no available LBR callchain information, should try fp
1605  * negative error code on other errors.
1606  */
1607 static int resolve_lbr_callchain_sample(struct thread *thread,
1608 					struct perf_sample *sample,
1609 					struct symbol **parent,
1610 					struct addr_location *root_al,
1611 					int max_stack)
1612 {
1613 	struct ip_callchain *chain = sample->callchain;
1614 	int chain_nr = min(max_stack, (int)chain->nr);
1615 	u8 cpumode = PERF_RECORD_MISC_USER;
1616 	int i, j, err;
1617 	u64 ip;
1618 
1619 	for (i = 0; i < chain_nr; i++) {
1620 		if (chain->ips[i] == PERF_CONTEXT_USER)
1621 			break;
1622 	}
1623 
1624 	/* LBR only affects the user callchain */
1625 	if (i != chain_nr) {
1626 		struct branch_stack *lbr_stack = sample->branch_stack;
1627 		int lbr_nr = lbr_stack->nr;
1628 		/*
1629 		 * LBR callstack can only get user call chain.
1630 		 * The mix_chain_nr is kernel call chain
1631 		 * number plus LBR user call chain number.
1632 		 * i is kernel call chain number,
1633 		 * 1 is PERF_CONTEXT_USER,
1634 		 * lbr_nr + 1 is the user call chain number.
1635 		 * For details, please refer to the comments
1636 		 * in callchain__printf
1637 		 */
1638 		int mix_chain_nr = i + 1 + lbr_nr + 1;
1639 
1640 		if (mix_chain_nr > PERF_MAX_STACK_DEPTH + PERF_MAX_BRANCH_DEPTH) {
1641 			pr_warning("corrupted callchain. skipping...\n");
1642 			return 0;
1643 		}
1644 
1645 		for (j = 0; j < mix_chain_nr; j++) {
1646 			if (callchain_param.order == ORDER_CALLEE) {
1647 				if (j < i + 1)
1648 					ip = chain->ips[j];
1649 				else if (j > i + 1)
1650 					ip = lbr_stack->entries[j - i - 2].from;
1651 				else
1652 					ip = lbr_stack->entries[0].to;
1653 			} else {
1654 				if (j < lbr_nr)
1655 					ip = lbr_stack->entries[lbr_nr - j - 1].from;
1656 				else if (j > lbr_nr)
1657 					ip = chain->ips[i + 1 - (j - lbr_nr)];
1658 				else
1659 					ip = lbr_stack->entries[0].to;
1660 			}
1661 
1662 			err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
1663 			if (err)
1664 				return (err < 0) ? err : 0;
1665 		}
1666 		return 1;
1667 	}
1668 
1669 	return 0;
1670 }
1671 
1672 static int thread__resolve_callchain_sample(struct thread *thread,
1673 					    struct perf_evsel *evsel,
1674 					    struct perf_sample *sample,
1675 					    struct symbol **parent,
1676 					    struct addr_location *root_al,
1677 					    int max_stack)
1678 {
1679 	struct branch_stack *branch = sample->branch_stack;
1680 	struct ip_callchain *chain = sample->callchain;
1681 	int chain_nr = min(max_stack, (int)chain->nr);
1682 	u8 cpumode = PERF_RECORD_MISC_USER;
1683 	int i, j, err;
1684 	int skip_idx = -1;
1685 	int first_call = 0;
1686 
1687 	callchain_cursor_reset(&callchain_cursor);
1688 
1689 	if (has_branch_callstack(evsel)) {
1690 		err = resolve_lbr_callchain_sample(thread, sample, parent,
1691 						   root_al, max_stack);
1692 		if (err)
1693 			return (err < 0) ? err : 0;
1694 	}
1695 
1696 	/*
1697 	 * Based on DWARF debug information, some architectures skip
1698 	 * a callchain entry saved by the kernel.
1699 	 */
1700 	if (chain->nr < PERF_MAX_STACK_DEPTH)
1701 		skip_idx = arch_skip_callchain_idx(thread, chain);
1702 
1703 	/*
1704 	 * Add branches to call stack for easier browsing. This gives
1705 	 * more context for a sample than just the callers.
1706 	 *
1707 	 * This uses individual histograms of paths compared to the
1708 	 * aggregated histograms the normal LBR mode uses.
1709 	 *
1710 	 * Limitations for now:
1711 	 * - No extra filters
1712 	 * - No annotations (should annotate somehow)
1713 	 */
1714 
1715 	if (branch && callchain_param.branch_callstack) {
1716 		int nr = min(max_stack, (int)branch->nr);
1717 		struct branch_entry be[nr];
1718 
1719 		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
1720 			pr_warning("corrupted branch chain. skipping...\n");
1721 			goto check_calls;
1722 		}
1723 
1724 		for (i = 0; i < nr; i++) {
1725 			if (callchain_param.order == ORDER_CALLEE) {
1726 				be[i] = branch->entries[i];
1727 				/*
1728 				 * Check for overlap into the callchain.
1729 				 * The return address is one off compared to
1730 				 * the branch entry. To adjust for this
1731 				 * assume the calling instruction is not longer
1732 				 * than 8 bytes.
1733 				 */
1734 				if (i == skip_idx ||
1735 				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
1736 					first_call++;
1737 				else if (be[i].from < chain->ips[first_call] &&
1738 				    be[i].from >= chain->ips[first_call] - 8)
1739 					first_call++;
1740 			} else
1741 				be[i] = branch->entries[branch->nr - i - 1];
1742 		}
1743 
1744 		nr = remove_loops(be, nr);
1745 
1746 		for (i = 0; i < nr; i++) {
1747 			err = add_callchain_ip(thread, parent, root_al,
1748 					       NULL, be[i].to);
1749 			if (!err)
1750 				err = add_callchain_ip(thread, parent, root_al,
1751 						       NULL, be[i].from);
1752 			if (err == -EINVAL)
1753 				break;
1754 			if (err)
1755 				return err;
1756 		}
1757 		chain_nr -= nr;
1758 	}
1759 
1760 check_calls:
1761 	if (chain->nr > PERF_MAX_STACK_DEPTH) {
1762 		pr_warning("corrupted callchain. skipping...\n");
1763 		return 0;
1764 	}
1765 
1766 	for (i = first_call; i < chain_nr; i++) {
1767 		u64 ip;
1768 
1769 		if (callchain_param.order == ORDER_CALLEE)
1770 			j = i;
1771 		else
1772 			j = chain->nr - i - 1;
1773 
1774 #ifdef HAVE_SKIP_CALLCHAIN_IDX
1775 		if (j == skip_idx)
1776 			continue;
1777 #endif
1778 		ip = chain->ips[j];
1779 
1780 		err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
1781 
1782 		if (err)
1783 			return (err < 0) ? err : 0;
1784 	}
1785 
1786 	return 0;
1787 }
1788 
1789 static int unwind_entry(struct unwind_entry *entry, void *arg)
1790 {
1791 	struct callchain_cursor *cursor = arg;
1792 	return callchain_cursor_append(cursor, entry->ip,
1793 				       entry->map, entry->sym);
1794 }
1795 
1796 int thread__resolve_callchain(struct thread *thread,
1797 			      struct perf_evsel *evsel,
1798 			      struct perf_sample *sample,
1799 			      struct symbol **parent,
1800 			      struct addr_location *root_al,
1801 			      int max_stack)
1802 {
1803 	int ret = thread__resolve_callchain_sample(thread, evsel,
1804 						   sample, parent,
1805 						   root_al, max_stack);
1806 	if (ret)
1807 		return ret;
1808 
1809 	/* Can we do dwarf post unwind? */
1810 	if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
1811 	      (evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
1812 		return 0;
1813 
1814 	/* Bail out if nothing was captured. */
1815 	if ((!sample->user_regs.regs) ||
1816 	    (!sample->user_stack.size))
1817 		return 0;
1818 
1819 	return unwind__get_entries(unwind_entry, &callchain_cursor,
1820 				   thread, sample, max_stack);
1821 
1822 }
1823 
1824 int machine__for_each_thread(struct machine *machine,
1825 			     int (*fn)(struct thread *thread, void *p),
1826 			     void *priv)
1827 {
1828 	struct rb_node *nd;
1829 	struct thread *thread;
1830 	int rc = 0;
1831 
1832 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
1833 		thread = rb_entry(nd, struct thread, rb_node);
1834 		rc = fn(thread, priv);
1835 		if (rc != 0)
1836 			return rc;
1837 	}
1838 
1839 	list_for_each_entry(thread, &machine->dead_threads, node) {
1840 		rc = fn(thread, priv);
1841 		if (rc != 0)
1842 			return rc;
1843 	}
1844 	return rc;
1845 }
1846 
1847 int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
1848 				  struct target *target, struct thread_map *threads,
1849 				  perf_event__handler_t process, bool data_mmap)
1850 {
1851 	if (target__has_task(target))
1852 		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
1853 	else if (target__has_cpu(target))
1854 		return perf_event__synthesize_threads(tool, process, machine, data_mmap);
1855 	/* command specified */
1856 	return 0;
1857 }
1858 
1859 pid_t machine__get_current_tid(struct machine *machine, int cpu)
1860 {
1861 	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
1862 		return -1;
1863 
1864 	return machine->current_tid[cpu];
1865 }
1866 
1867 int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
1868 			     pid_t tid)
1869 {
1870 	struct thread *thread;
1871 
1872 	if (cpu < 0)
1873 		return -EINVAL;
1874 
1875 	if (!machine->current_tid) {
1876 		int i;
1877 
1878 		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
1879 		if (!machine->current_tid)
1880 			return -ENOMEM;
1881 		for (i = 0; i < MAX_NR_CPUS; i++)
1882 			machine->current_tid[i] = -1;
1883 	}
1884 
1885 	if (cpu >= MAX_NR_CPUS) {
1886 		pr_err("Requested CPU %d too large. ", cpu);
1887 		pr_err("Consider raising MAX_NR_CPUS\n");
1888 		return -EINVAL;
1889 	}
1890 
1891 	machine->current_tid[cpu] = tid;
1892 
1893 	thread = machine__findnew_thread(machine, pid, tid);
1894 	if (!thread)
1895 		return -ENOMEM;
1896 
1897 	thread->cpu = cpu;
1898 	thread__put(thread);
1899 
1900 	return 0;
1901 }
1902 
1903 int machine__get_kernel_start(struct machine *machine)
1904 {
1905 	struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
1906 	int err = 0;
1907 
1908 	/*
1909 	 * The only addresses above 2^63 are kernel addresses of a 64-bit
1910 	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
1911 	 * all addresses including kernel addresses are less than 2^32.  In
1912 	 * that case (32-bit system), if the kernel mapping is unknown, all
1913 	 * addresses will be assumed to be in user space - see
1914 	 * machine__kernel_ip().
1915 	 */
1916 	machine->kernel_start = 1ULL << 63;
1917 	if (map) {
1918 		err = map__load(map, machine->symbol_filter);
1919 		if (map->start)
1920 			machine->kernel_start = map->start;
1921 	}
1922 	return err;
1923 }
1924