xref: /openbmc/linux/tools/perf/util/machine.c (revision 0da85d1e)
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 dsos__init(struct dsos *dsos)
18 {
19 	INIT_LIST_HEAD(&dsos->head);
20 	dsos->root = RB_ROOT;
21 }
22 
23 int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
24 {
25 	map_groups__init(&machine->kmaps, machine);
26 	RB_CLEAR_NODE(&machine->rb_node);
27 	dsos__init(&machine->user_dsos);
28 	dsos__init(&machine->kernel_dsos);
29 
30 	machine->threads = RB_ROOT;
31 	INIT_LIST_HEAD(&machine->dead_threads);
32 	machine->last_match = NULL;
33 
34 	machine->vdso_info = NULL;
35 
36 	machine->pid = pid;
37 
38 	machine->symbol_filter = NULL;
39 	machine->id_hdr_size = 0;
40 	machine->comm_exec = false;
41 	machine->kernel_start = 0;
42 
43 	machine->root_dir = strdup(root_dir);
44 	if (machine->root_dir == NULL)
45 		return -ENOMEM;
46 
47 	if (pid != HOST_KERNEL_ID) {
48 		struct thread *thread = machine__findnew_thread(machine, -1,
49 								pid);
50 		char comm[64];
51 
52 		if (thread == NULL)
53 			return -ENOMEM;
54 
55 		snprintf(comm, sizeof(comm), "[guest/%d]", pid);
56 		thread__set_comm(thread, comm, 0);
57 	}
58 
59 	machine->current_tid = NULL;
60 
61 	return 0;
62 }
63 
64 struct machine *machine__new_host(void)
65 {
66 	struct machine *machine = malloc(sizeof(*machine));
67 
68 	if (machine != NULL) {
69 		machine__init(machine, "", HOST_KERNEL_ID);
70 
71 		if (machine__create_kernel_maps(machine) < 0)
72 			goto out_delete;
73 	}
74 
75 	return machine;
76 out_delete:
77 	free(machine);
78 	return NULL;
79 }
80 
81 static void dsos__delete(struct dsos *dsos)
82 {
83 	struct dso *pos, *n;
84 
85 	list_for_each_entry_safe(pos, n, &dsos->head, node) {
86 		RB_CLEAR_NODE(&pos->rb_node);
87 		list_del(&pos->node);
88 		dso__delete(pos);
89 	}
90 }
91 
92 void machine__delete_threads(struct machine *machine)
93 {
94 	struct rb_node *nd = rb_first(&machine->threads);
95 
96 	while (nd) {
97 		struct thread *t = rb_entry(nd, struct thread, rb_node);
98 
99 		nd = rb_next(nd);
100 		machine__remove_thread(machine, t);
101 	}
102 }
103 
104 void machine__exit(struct machine *machine)
105 {
106 	map_groups__exit(&machine->kmaps);
107 	dsos__delete(&machine->user_dsos);
108 	dsos__delete(&machine->kernel_dsos);
109 	vdso__exit(machine);
110 	zfree(&machine->root_dir);
111 	zfree(&machine->current_tid);
112 }
113 
114 void machine__delete(struct machine *machine)
115 {
116 	machine__exit(machine);
117 	free(machine);
118 }
119 
120 void machines__init(struct machines *machines)
121 {
122 	machine__init(&machines->host, "", HOST_KERNEL_ID);
123 	machines->guests = RB_ROOT;
124 	machines->symbol_filter = NULL;
125 }
126 
127 void machines__exit(struct machines *machines)
128 {
129 	machine__exit(&machines->host);
130 	/* XXX exit guest */
131 }
132 
133 struct machine *machines__add(struct machines *machines, pid_t pid,
134 			      const char *root_dir)
135 {
136 	struct rb_node **p = &machines->guests.rb_node;
137 	struct rb_node *parent = NULL;
138 	struct machine *pos, *machine = malloc(sizeof(*machine));
139 
140 	if (machine == NULL)
141 		return NULL;
142 
143 	if (machine__init(machine, root_dir, pid) != 0) {
144 		free(machine);
145 		return NULL;
146 	}
147 
148 	machine->symbol_filter = machines->symbol_filter;
149 
150 	while (*p != NULL) {
151 		parent = *p;
152 		pos = rb_entry(parent, struct machine, rb_node);
153 		if (pid < pos->pid)
154 			p = &(*p)->rb_left;
155 		else
156 			p = &(*p)->rb_right;
157 	}
158 
159 	rb_link_node(&machine->rb_node, parent, p);
160 	rb_insert_color(&machine->rb_node, &machines->guests);
161 
162 	return machine;
163 }
164 
165 void machines__set_symbol_filter(struct machines *machines,
166 				 symbol_filter_t symbol_filter)
167 {
168 	struct rb_node *nd;
169 
170 	machines->symbol_filter = symbol_filter;
171 	machines->host.symbol_filter = symbol_filter;
172 
173 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
174 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
175 
176 		machine->symbol_filter = symbol_filter;
177 	}
178 }
179 
180 void machines__set_comm_exec(struct machines *machines, bool comm_exec)
181 {
182 	struct rb_node *nd;
183 
184 	machines->host.comm_exec = comm_exec;
185 
186 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
187 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
188 
189 		machine->comm_exec = comm_exec;
190 	}
191 }
192 
193 struct machine *machines__find(struct machines *machines, pid_t pid)
194 {
195 	struct rb_node **p = &machines->guests.rb_node;
196 	struct rb_node *parent = NULL;
197 	struct machine *machine;
198 	struct machine *default_machine = NULL;
199 
200 	if (pid == HOST_KERNEL_ID)
201 		return &machines->host;
202 
203 	while (*p != NULL) {
204 		parent = *p;
205 		machine = rb_entry(parent, struct machine, rb_node);
206 		if (pid < machine->pid)
207 			p = &(*p)->rb_left;
208 		else if (pid > machine->pid)
209 			p = &(*p)->rb_right;
210 		else
211 			return machine;
212 		if (!machine->pid)
213 			default_machine = machine;
214 	}
215 
216 	return default_machine;
217 }
218 
219 struct machine *machines__findnew(struct machines *machines, pid_t pid)
220 {
221 	char path[PATH_MAX];
222 	const char *root_dir = "";
223 	struct machine *machine = machines__find(machines, pid);
224 
225 	if (machine && (machine->pid == pid))
226 		goto out;
227 
228 	if ((pid != HOST_KERNEL_ID) &&
229 	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
230 	    (symbol_conf.guestmount)) {
231 		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
232 		if (access(path, R_OK)) {
233 			static struct strlist *seen;
234 
235 			if (!seen)
236 				seen = strlist__new(true, NULL);
237 
238 			if (!strlist__has_entry(seen, path)) {
239 				pr_err("Can't access file %s\n", path);
240 				strlist__add(seen, path);
241 			}
242 			machine = NULL;
243 			goto out;
244 		}
245 		root_dir = path;
246 	}
247 
248 	machine = machines__add(machines, pid, root_dir);
249 out:
250 	return machine;
251 }
252 
253 void machines__process_guests(struct machines *machines,
254 			      machine__process_t process, void *data)
255 {
256 	struct rb_node *nd;
257 
258 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
259 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
260 		process(pos, data);
261 	}
262 }
263 
264 char *machine__mmap_name(struct machine *machine, char *bf, size_t size)
265 {
266 	if (machine__is_host(machine))
267 		snprintf(bf, size, "[%s]", "kernel.kallsyms");
268 	else if (machine__is_default_guest(machine))
269 		snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
270 	else {
271 		snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms",
272 			 machine->pid);
273 	}
274 
275 	return bf;
276 }
277 
278 void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size)
279 {
280 	struct rb_node *node;
281 	struct machine *machine;
282 
283 	machines->host.id_hdr_size = id_hdr_size;
284 
285 	for (node = rb_first(&machines->guests); node; node = rb_next(node)) {
286 		machine = rb_entry(node, struct machine, rb_node);
287 		machine->id_hdr_size = id_hdr_size;
288 	}
289 
290 	return;
291 }
292 
293 static void machine__update_thread_pid(struct machine *machine,
294 				       struct thread *th, pid_t pid)
295 {
296 	struct thread *leader;
297 
298 	if (pid == th->pid_ || pid == -1 || th->pid_ != -1)
299 		return;
300 
301 	th->pid_ = pid;
302 
303 	if (th->pid_ == th->tid)
304 		return;
305 
306 	leader = machine__findnew_thread(machine, th->pid_, th->pid_);
307 	if (!leader)
308 		goto out_err;
309 
310 	if (!leader->mg)
311 		leader->mg = map_groups__new(machine);
312 
313 	if (!leader->mg)
314 		goto out_err;
315 
316 	if (th->mg == leader->mg)
317 		return;
318 
319 	if (th->mg) {
320 		/*
321 		 * Maps are created from MMAP events which provide the pid and
322 		 * tid.  Consequently there never should be any maps on a thread
323 		 * with an unknown pid.  Just print an error if there are.
324 		 */
325 		if (!map_groups__empty(th->mg))
326 			pr_err("Discarding thread maps for %d:%d\n",
327 			       th->pid_, th->tid);
328 		map_groups__delete(th->mg);
329 	}
330 
331 	th->mg = map_groups__get(leader->mg);
332 
333 	return;
334 
335 out_err:
336 	pr_err("Failed to join map groups for %d:%d\n", th->pid_, th->tid);
337 }
338 
339 static struct thread *__machine__findnew_thread(struct machine *machine,
340 						pid_t pid, pid_t tid,
341 						bool create)
342 {
343 	struct rb_node **p = &machine->threads.rb_node;
344 	struct rb_node *parent = NULL;
345 	struct thread *th;
346 
347 	/*
348 	 * Front-end cache - TID lookups come in blocks,
349 	 * so most of the time we dont have to look up
350 	 * the full rbtree:
351 	 */
352 	th = machine->last_match;
353 	if (th != NULL) {
354 		if (th->tid == tid) {
355 			machine__update_thread_pid(machine, th, pid);
356 			return th;
357 		}
358 
359 		thread__zput(machine->last_match);
360 	}
361 
362 	while (*p != NULL) {
363 		parent = *p;
364 		th = rb_entry(parent, struct thread, rb_node);
365 
366 		if (th->tid == tid) {
367 			machine->last_match = thread__get(th);
368 			machine__update_thread_pid(machine, th, pid);
369 			return th;
370 		}
371 
372 		if (tid < th->tid)
373 			p = &(*p)->rb_left;
374 		else
375 			p = &(*p)->rb_right;
376 	}
377 
378 	if (!create)
379 		return NULL;
380 
381 	th = thread__new(pid, tid);
382 	if (th != NULL) {
383 		rb_link_node(&th->rb_node, parent, p);
384 		rb_insert_color(&th->rb_node, &machine->threads);
385 
386 		/*
387 		 * We have to initialize map_groups separately
388 		 * after rb tree is updated.
389 		 *
390 		 * The reason is that we call machine__findnew_thread
391 		 * within thread__init_map_groups to find the thread
392 		 * leader and that would screwed the rb tree.
393 		 */
394 		if (thread__init_map_groups(th, machine)) {
395 			rb_erase(&th->rb_node, &machine->threads);
396 			thread__delete(th);
397 			return NULL;
398 		}
399 		/*
400 		 * It is now in the rbtree, get a ref
401 		 */
402 		thread__get(th);
403 		machine->last_match = thread__get(th);
404 	}
405 
406 	return th;
407 }
408 
409 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
410 				       pid_t tid)
411 {
412 	return __machine__findnew_thread(machine, pid, tid, true);
413 }
414 
415 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
416 				    pid_t tid)
417 {
418 	return __machine__findnew_thread(machine, pid, tid, false);
419 }
420 
421 struct comm *machine__thread_exec_comm(struct machine *machine,
422 				       struct thread *thread)
423 {
424 	if (machine->comm_exec)
425 		return thread__exec_comm(thread);
426 	else
427 		return thread__comm(thread);
428 }
429 
430 int machine__process_comm_event(struct machine *machine, union perf_event *event,
431 				struct perf_sample *sample)
432 {
433 	struct thread *thread = machine__findnew_thread(machine,
434 							event->comm.pid,
435 							event->comm.tid);
436 	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;
437 
438 	if (exec)
439 		machine->comm_exec = true;
440 
441 	if (dump_trace)
442 		perf_event__fprintf_comm(event, stdout);
443 
444 	if (thread == NULL ||
445 	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {
446 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
447 		return -1;
448 	}
449 
450 	return 0;
451 }
452 
453 int machine__process_lost_event(struct machine *machine __maybe_unused,
454 				union perf_event *event, struct perf_sample *sample __maybe_unused)
455 {
456 	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
457 		    event->lost.id, event->lost.lost);
458 	return 0;
459 }
460 
461 static struct dso*
462 machine__module_dso(struct machine *machine, struct kmod_path *m,
463 		    const char *filename)
464 {
465 	struct dso *dso;
466 
467 	dso = dsos__find(&machine->kernel_dsos, m->name, true);
468 	if (!dso) {
469 		dso = dsos__addnew(&machine->kernel_dsos, m->name);
470 		if (dso == NULL)
471 			return NULL;
472 
473 		if (machine__is_host(machine))
474 			dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
475 		else
476 			dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;
477 
478 		/* _KMODULE_COMP should be next to _KMODULE */
479 		if (m->kmod && m->comp)
480 			dso->symtab_type++;
481 
482 		dso__set_short_name(dso, strdup(m->name), true);
483 		dso__set_long_name(dso, strdup(filename), true);
484 	}
485 
486 	return dso;
487 }
488 
489 int machine__process_aux_event(struct machine *machine __maybe_unused,
490 			       union perf_event *event)
491 {
492 	if (dump_trace)
493 		perf_event__fprintf_aux(event, stdout);
494 	return 0;
495 }
496 
497 int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
498 					union perf_event *event)
499 {
500 	if (dump_trace)
501 		perf_event__fprintf_itrace_start(event, stdout);
502 	return 0;
503 }
504 
505 struct map *machine__new_module(struct machine *machine, u64 start,
506 				const char *filename)
507 {
508 	struct map *map = NULL;
509 	struct dso *dso;
510 	struct kmod_path m;
511 
512 	if (kmod_path__parse_name(&m, filename))
513 		return NULL;
514 
515 	map = map_groups__find_by_name(&machine->kmaps, MAP__FUNCTION,
516 				       m.name);
517 	if (map)
518 		goto out;
519 
520 	dso = machine__module_dso(machine, &m, filename);
521 	if (dso == NULL)
522 		goto out;
523 
524 	map = map__new2(start, dso, MAP__FUNCTION);
525 	if (map == NULL)
526 		goto out;
527 
528 	map_groups__insert(&machine->kmaps, map);
529 
530 out:
531 	free(m.name);
532 	return map;
533 }
534 
535 size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
536 {
537 	struct rb_node *nd;
538 	size_t ret = __dsos__fprintf(&machines->host.kernel_dsos.head, fp) +
539 		     __dsos__fprintf(&machines->host.user_dsos.head, fp);
540 
541 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
542 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
543 		ret += __dsos__fprintf(&pos->kernel_dsos.head, fp);
544 		ret += __dsos__fprintf(&pos->user_dsos.head, fp);
545 	}
546 
547 	return ret;
548 }
549 
550 size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,
551 				     bool (skip)(struct dso *dso, int parm), int parm)
552 {
553 	return __dsos__fprintf_buildid(&m->kernel_dsos.head, fp, skip, parm) +
554 	       __dsos__fprintf_buildid(&m->user_dsos.head, fp, skip, parm);
555 }
556 
557 size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,
558 				     bool (skip)(struct dso *dso, int parm), int parm)
559 {
560 	struct rb_node *nd;
561 	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);
562 
563 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
564 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
565 		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
566 	}
567 	return ret;
568 }
569 
570 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
571 {
572 	int i;
573 	size_t printed = 0;
574 	struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
575 
576 	if (kdso->has_build_id) {
577 		char filename[PATH_MAX];
578 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
579 			printed += fprintf(fp, "[0] %s\n", filename);
580 	}
581 
582 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
583 		printed += fprintf(fp, "[%d] %s\n",
584 				   i + kdso->has_build_id, vmlinux_path[i]);
585 
586 	return printed;
587 }
588 
589 size_t machine__fprintf(struct machine *machine, FILE *fp)
590 {
591 	size_t ret = 0;
592 	struct rb_node *nd;
593 
594 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
595 		struct thread *pos = rb_entry(nd, struct thread, rb_node);
596 
597 		ret += thread__fprintf(pos, fp);
598 	}
599 
600 	return ret;
601 }
602 
603 static struct dso *machine__get_kernel(struct machine *machine)
604 {
605 	const char *vmlinux_name = NULL;
606 	struct dso *kernel;
607 
608 	if (machine__is_host(machine)) {
609 		vmlinux_name = symbol_conf.vmlinux_name;
610 		if (!vmlinux_name)
611 			vmlinux_name = "[kernel.kallsyms]";
612 
613 		kernel = dso__kernel_findnew(machine, vmlinux_name,
614 					     "[kernel]",
615 					     DSO_TYPE_KERNEL);
616 	} else {
617 		char bf[PATH_MAX];
618 
619 		if (machine__is_default_guest(machine))
620 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
621 		if (!vmlinux_name)
622 			vmlinux_name = machine__mmap_name(machine, bf,
623 							  sizeof(bf));
624 
625 		kernel = dso__kernel_findnew(machine, vmlinux_name,
626 					     "[guest.kernel]",
627 					     DSO_TYPE_GUEST_KERNEL);
628 	}
629 
630 	if (kernel != NULL && (!kernel->has_build_id))
631 		dso__read_running_kernel_build_id(kernel, machine);
632 
633 	return kernel;
634 }
635 
636 struct process_args {
637 	u64 start;
638 };
639 
640 static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
641 					   size_t bufsz)
642 {
643 	if (machine__is_default_guest(machine))
644 		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
645 	else
646 		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
647 }
648 
649 const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
650 
651 /* Figure out the start address of kernel map from /proc/kallsyms.
652  * Returns the name of the start symbol in *symbol_name. Pass in NULL as
653  * symbol_name if it's not that important.
654  */
655 static u64 machine__get_running_kernel_start(struct machine *machine,
656 					     const char **symbol_name)
657 {
658 	char filename[PATH_MAX];
659 	int i;
660 	const char *name;
661 	u64 addr = 0;
662 
663 	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
664 
665 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
666 		return 0;
667 
668 	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
669 		addr = kallsyms__get_function_start(filename, name);
670 		if (addr)
671 			break;
672 	}
673 
674 	if (symbol_name)
675 		*symbol_name = name;
676 
677 	return addr;
678 }
679 
680 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
681 {
682 	enum map_type type;
683 	u64 start = machine__get_running_kernel_start(machine, NULL);
684 
685 	for (type = 0; type < MAP__NR_TYPES; ++type) {
686 		struct kmap *kmap;
687 
688 		machine->vmlinux_maps[type] = map__new2(start, kernel, type);
689 		if (machine->vmlinux_maps[type] == NULL)
690 			return -1;
691 
692 		machine->vmlinux_maps[type]->map_ip =
693 			machine->vmlinux_maps[type]->unmap_ip =
694 				identity__map_ip;
695 		kmap = map__kmap(machine->vmlinux_maps[type]);
696 		if (!kmap)
697 			return -1;
698 
699 		kmap->kmaps = &machine->kmaps;
700 		map_groups__insert(&machine->kmaps,
701 				   machine->vmlinux_maps[type]);
702 	}
703 
704 	return 0;
705 }
706 
707 void machine__destroy_kernel_maps(struct machine *machine)
708 {
709 	enum map_type type;
710 
711 	for (type = 0; type < MAP__NR_TYPES; ++type) {
712 		struct kmap *kmap;
713 
714 		if (machine->vmlinux_maps[type] == NULL)
715 			continue;
716 
717 		kmap = map__kmap(machine->vmlinux_maps[type]);
718 		map_groups__remove(&machine->kmaps,
719 				   machine->vmlinux_maps[type]);
720 		if (kmap && kmap->ref_reloc_sym) {
721 			/*
722 			 * ref_reloc_sym is shared among all maps, so free just
723 			 * on one of them.
724 			 */
725 			if (type == MAP__FUNCTION) {
726 				zfree((char **)&kmap->ref_reloc_sym->name);
727 				zfree(&kmap->ref_reloc_sym);
728 			} else
729 				kmap->ref_reloc_sym = NULL;
730 		}
731 
732 		map__delete(machine->vmlinux_maps[type]);
733 		machine->vmlinux_maps[type] = NULL;
734 	}
735 }
736 
737 int machines__create_guest_kernel_maps(struct machines *machines)
738 {
739 	int ret = 0;
740 	struct dirent **namelist = NULL;
741 	int i, items = 0;
742 	char path[PATH_MAX];
743 	pid_t pid;
744 	char *endp;
745 
746 	if (symbol_conf.default_guest_vmlinux_name ||
747 	    symbol_conf.default_guest_modules ||
748 	    symbol_conf.default_guest_kallsyms) {
749 		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
750 	}
751 
752 	if (symbol_conf.guestmount) {
753 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
754 		if (items <= 0)
755 			return -ENOENT;
756 		for (i = 0; i < items; i++) {
757 			if (!isdigit(namelist[i]->d_name[0])) {
758 				/* Filter out . and .. */
759 				continue;
760 			}
761 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
762 			if ((*endp != '\0') ||
763 			    (endp == namelist[i]->d_name) ||
764 			    (errno == ERANGE)) {
765 				pr_debug("invalid directory (%s). Skipping.\n",
766 					 namelist[i]->d_name);
767 				continue;
768 			}
769 			sprintf(path, "%s/%s/proc/kallsyms",
770 				symbol_conf.guestmount,
771 				namelist[i]->d_name);
772 			ret = access(path, R_OK);
773 			if (ret) {
774 				pr_debug("Can't access file %s\n", path);
775 				goto failure;
776 			}
777 			machines__create_kernel_maps(machines, pid);
778 		}
779 failure:
780 		free(namelist);
781 	}
782 
783 	return ret;
784 }
785 
786 void machines__destroy_kernel_maps(struct machines *machines)
787 {
788 	struct rb_node *next = rb_first(&machines->guests);
789 
790 	machine__destroy_kernel_maps(&machines->host);
791 
792 	while (next) {
793 		struct machine *pos = rb_entry(next, struct machine, rb_node);
794 
795 		next = rb_next(&pos->rb_node);
796 		rb_erase(&pos->rb_node, &machines->guests);
797 		machine__delete(pos);
798 	}
799 }
800 
801 int machines__create_kernel_maps(struct machines *machines, pid_t pid)
802 {
803 	struct machine *machine = machines__findnew(machines, pid);
804 
805 	if (machine == NULL)
806 		return -1;
807 
808 	return machine__create_kernel_maps(machine);
809 }
810 
811 int machine__load_kallsyms(struct machine *machine, const char *filename,
812 			   enum map_type type, symbol_filter_t filter)
813 {
814 	struct map *map = machine->vmlinux_maps[type];
815 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
816 
817 	if (ret > 0) {
818 		dso__set_loaded(map->dso, type);
819 		/*
820 		 * Since /proc/kallsyms will have multiple sessions for the
821 		 * kernel, with modules between them, fixup the end of all
822 		 * sections.
823 		 */
824 		__map_groups__fixup_end(&machine->kmaps, type);
825 	}
826 
827 	return ret;
828 }
829 
830 int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
831 			       symbol_filter_t filter)
832 {
833 	struct map *map = machine->vmlinux_maps[type];
834 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
835 
836 	if (ret > 0)
837 		dso__set_loaded(map->dso, type);
838 
839 	return ret;
840 }
841 
842 static void map_groups__fixup_end(struct map_groups *mg)
843 {
844 	int i;
845 	for (i = 0; i < MAP__NR_TYPES; ++i)
846 		__map_groups__fixup_end(mg, i);
847 }
848 
849 static char *get_kernel_version(const char *root_dir)
850 {
851 	char version[PATH_MAX];
852 	FILE *file;
853 	char *name, *tmp;
854 	const char *prefix = "Linux version ";
855 
856 	sprintf(version, "%s/proc/version", root_dir);
857 	file = fopen(version, "r");
858 	if (!file)
859 		return NULL;
860 
861 	version[0] = '\0';
862 	tmp = fgets(version, sizeof(version), file);
863 	fclose(file);
864 
865 	name = strstr(version, prefix);
866 	if (!name)
867 		return NULL;
868 	name += strlen(prefix);
869 	tmp = strchr(name, ' ');
870 	if (tmp)
871 		*tmp = '\0';
872 
873 	return strdup(name);
874 }
875 
876 static bool is_kmod_dso(struct dso *dso)
877 {
878 	return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
879 	       dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
880 }
881 
882 static int map_groups__set_module_path(struct map_groups *mg, const char *path,
883 				       struct kmod_path *m)
884 {
885 	struct map *map;
886 	char *long_name;
887 
888 	map = map_groups__find_by_name(mg, MAP__FUNCTION, m->name);
889 	if (map == NULL)
890 		return 0;
891 
892 	long_name = strdup(path);
893 	if (long_name == NULL)
894 		return -ENOMEM;
895 
896 	dso__set_long_name(map->dso, long_name, true);
897 	dso__kernel_module_get_build_id(map->dso, "");
898 
899 	/*
900 	 * Full name could reveal us kmod compression, so
901 	 * we need to update the symtab_type if needed.
902 	 */
903 	if (m->comp && is_kmod_dso(map->dso))
904 		map->dso->symtab_type++;
905 
906 	return 0;
907 }
908 
909 static int map_groups__set_modules_path_dir(struct map_groups *mg,
910 				const char *dir_name, int depth)
911 {
912 	struct dirent *dent;
913 	DIR *dir = opendir(dir_name);
914 	int ret = 0;
915 
916 	if (!dir) {
917 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
918 		return -1;
919 	}
920 
921 	while ((dent = readdir(dir)) != NULL) {
922 		char path[PATH_MAX];
923 		struct stat st;
924 
925 		/*sshfs might return bad dent->d_type, so we have to stat*/
926 		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
927 		if (stat(path, &st))
928 			continue;
929 
930 		if (S_ISDIR(st.st_mode)) {
931 			if (!strcmp(dent->d_name, ".") ||
932 			    !strcmp(dent->d_name, ".."))
933 				continue;
934 
935 			/* Do not follow top-level source and build symlinks */
936 			if (depth == 0) {
937 				if (!strcmp(dent->d_name, "source") ||
938 				    !strcmp(dent->d_name, "build"))
939 					continue;
940 			}
941 
942 			ret = map_groups__set_modules_path_dir(mg, path,
943 							       depth + 1);
944 			if (ret < 0)
945 				goto out;
946 		} else {
947 			struct kmod_path m;
948 
949 			ret = kmod_path__parse_name(&m, dent->d_name);
950 			if (ret)
951 				goto out;
952 
953 			if (m.kmod)
954 				ret = map_groups__set_module_path(mg, path, &m);
955 
956 			free(m.name);
957 
958 			if (ret)
959 				goto out;
960 		}
961 	}
962 
963 out:
964 	closedir(dir);
965 	return ret;
966 }
967 
968 static int machine__set_modules_path(struct machine *machine)
969 {
970 	char *version;
971 	char modules_path[PATH_MAX];
972 
973 	version = get_kernel_version(machine->root_dir);
974 	if (!version)
975 		return -1;
976 
977 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",
978 		 machine->root_dir, version);
979 	free(version);
980 
981 	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0);
982 }
983 
984 static int machine__create_module(void *arg, const char *name, u64 start)
985 {
986 	struct machine *machine = arg;
987 	struct map *map;
988 
989 	map = machine__new_module(machine, start, name);
990 	if (map == NULL)
991 		return -1;
992 
993 	dso__kernel_module_get_build_id(map->dso, machine->root_dir);
994 
995 	return 0;
996 }
997 
998 static int machine__create_modules(struct machine *machine)
999 {
1000 	const char *modules;
1001 	char path[PATH_MAX];
1002 
1003 	if (machine__is_default_guest(machine)) {
1004 		modules = symbol_conf.default_guest_modules;
1005 	} else {
1006 		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);
1007 		modules = path;
1008 	}
1009 
1010 	if (symbol__restricted_filename(modules, "/proc/modules"))
1011 		return -1;
1012 
1013 	if (modules__parse(modules, machine, machine__create_module))
1014 		return -1;
1015 
1016 	if (!machine__set_modules_path(machine))
1017 		return 0;
1018 
1019 	pr_debug("Problems setting modules path maps, continuing anyway...\n");
1020 
1021 	return 0;
1022 }
1023 
1024 int machine__create_kernel_maps(struct machine *machine)
1025 {
1026 	struct dso *kernel = machine__get_kernel(machine);
1027 	const char *name;
1028 	u64 addr = machine__get_running_kernel_start(machine, &name);
1029 	if (!addr)
1030 		return -1;
1031 
1032 	if (kernel == NULL ||
1033 	    __machine__create_kernel_maps(machine, kernel) < 0)
1034 		return -1;
1035 
1036 	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
1037 		if (machine__is_host(machine))
1038 			pr_debug("Problems creating module maps, "
1039 				 "continuing anyway...\n");
1040 		else
1041 			pr_debug("Problems creating module maps for guest %d, "
1042 				 "continuing anyway...\n", machine->pid);
1043 	}
1044 
1045 	/*
1046 	 * Now that we have all the maps created, just set the ->end of them:
1047 	 */
1048 	map_groups__fixup_end(&machine->kmaps);
1049 
1050 	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
1051 					     addr)) {
1052 		machine__destroy_kernel_maps(machine);
1053 		return -1;
1054 	}
1055 
1056 	return 0;
1057 }
1058 
1059 static void machine__set_kernel_mmap_len(struct machine *machine,
1060 					 union perf_event *event)
1061 {
1062 	int i;
1063 
1064 	for (i = 0; i < MAP__NR_TYPES; i++) {
1065 		machine->vmlinux_maps[i]->start = event->mmap.start;
1066 		machine->vmlinux_maps[i]->end   = (event->mmap.start +
1067 						   event->mmap.len);
1068 		/*
1069 		 * Be a bit paranoid here, some perf.data file came with
1070 		 * a zero sized synthesized MMAP event for the kernel.
1071 		 */
1072 		if (machine->vmlinux_maps[i]->end == 0)
1073 			machine->vmlinux_maps[i]->end = ~0ULL;
1074 	}
1075 }
1076 
1077 static bool machine__uses_kcore(struct machine *machine)
1078 {
1079 	struct dso *dso;
1080 
1081 	list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1082 		if (dso__is_kcore(dso))
1083 			return true;
1084 	}
1085 
1086 	return false;
1087 }
1088 
1089 static int machine__process_kernel_mmap_event(struct machine *machine,
1090 					      union perf_event *event)
1091 {
1092 	struct map *map;
1093 	char kmmap_prefix[PATH_MAX];
1094 	enum dso_kernel_type kernel_type;
1095 	bool is_kernel_mmap;
1096 
1097 	/* If we have maps from kcore then we do not need or want any others */
1098 	if (machine__uses_kcore(machine))
1099 		return 0;
1100 
1101 	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
1102 	if (machine__is_host(machine))
1103 		kernel_type = DSO_TYPE_KERNEL;
1104 	else
1105 		kernel_type = DSO_TYPE_GUEST_KERNEL;
1106 
1107 	is_kernel_mmap = memcmp(event->mmap.filename,
1108 				kmmap_prefix,
1109 				strlen(kmmap_prefix) - 1) == 0;
1110 	if (event->mmap.filename[0] == '/' ||
1111 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
1112 		map = machine__new_module(machine, event->mmap.start,
1113 					  event->mmap.filename);
1114 		if (map == NULL)
1115 			goto out_problem;
1116 
1117 		map->end = map->start + event->mmap.len;
1118 	} else if (is_kernel_mmap) {
1119 		const char *symbol_name = (event->mmap.filename +
1120 				strlen(kmmap_prefix));
1121 		/*
1122 		 * Should be there already, from the build-id table in
1123 		 * the header.
1124 		 */
1125 		struct dso *kernel = NULL;
1126 		struct dso *dso;
1127 
1128 		list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1129 			if (is_kernel_module(dso->long_name))
1130 				continue;
1131 
1132 			kernel = dso;
1133 			break;
1134 		}
1135 
1136 		if (kernel == NULL)
1137 			kernel = __dsos__findnew(&machine->kernel_dsos,
1138 						 kmmap_prefix);
1139 		if (kernel == NULL)
1140 			goto out_problem;
1141 
1142 		kernel->kernel = kernel_type;
1143 		if (__machine__create_kernel_maps(machine, kernel) < 0)
1144 			goto out_problem;
1145 
1146 		if (strstr(kernel->long_name, "vmlinux"))
1147 			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
1148 
1149 		machine__set_kernel_mmap_len(machine, event);
1150 
1151 		/*
1152 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
1153 		 * symbol. Effectively having zero here means that at record
1154 		 * time /proc/sys/kernel/kptr_restrict was non zero.
1155 		 */
1156 		if (event->mmap.pgoff != 0) {
1157 			maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
1158 							 symbol_name,
1159 							 event->mmap.pgoff);
1160 		}
1161 
1162 		if (machine__is_default_guest(machine)) {
1163 			/*
1164 			 * preload dso of guest kernel and modules
1165 			 */
1166 			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
1167 				  NULL);
1168 		}
1169 	}
1170 	return 0;
1171 out_problem:
1172 	return -1;
1173 }
1174 
1175 int machine__process_mmap2_event(struct machine *machine,
1176 				 union perf_event *event,
1177 				 struct perf_sample *sample __maybe_unused)
1178 {
1179 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1180 	struct thread *thread;
1181 	struct map *map;
1182 	enum map_type type;
1183 	int ret = 0;
1184 
1185 	if (dump_trace)
1186 		perf_event__fprintf_mmap2(event, stdout);
1187 
1188 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1189 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1190 		ret = machine__process_kernel_mmap_event(machine, event);
1191 		if (ret < 0)
1192 			goto out_problem;
1193 		return 0;
1194 	}
1195 
1196 	thread = machine__findnew_thread(machine, event->mmap2.pid,
1197 					event->mmap2.tid);
1198 	if (thread == NULL)
1199 		goto out_problem;
1200 
1201 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1202 		type = MAP__VARIABLE;
1203 	else
1204 		type = MAP__FUNCTION;
1205 
1206 	map = map__new(machine, event->mmap2.start,
1207 			event->mmap2.len, event->mmap2.pgoff,
1208 			event->mmap2.pid, event->mmap2.maj,
1209 			event->mmap2.min, event->mmap2.ino,
1210 			event->mmap2.ino_generation,
1211 			event->mmap2.prot,
1212 			event->mmap2.flags,
1213 			event->mmap2.filename, type, thread);
1214 
1215 	if (map == NULL)
1216 		goto out_problem;
1217 
1218 	thread__insert_map(thread, map);
1219 	return 0;
1220 
1221 out_problem:
1222 	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
1223 	return 0;
1224 }
1225 
1226 int machine__process_mmap_event(struct machine *machine, union perf_event *event,
1227 				struct perf_sample *sample __maybe_unused)
1228 {
1229 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1230 	struct thread *thread;
1231 	struct map *map;
1232 	enum map_type type;
1233 	int ret = 0;
1234 
1235 	if (dump_trace)
1236 		perf_event__fprintf_mmap(event, stdout);
1237 
1238 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1239 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1240 		ret = machine__process_kernel_mmap_event(machine, event);
1241 		if (ret < 0)
1242 			goto out_problem;
1243 		return 0;
1244 	}
1245 
1246 	thread = machine__findnew_thread(machine, event->mmap.pid,
1247 					 event->mmap.tid);
1248 	if (thread == NULL)
1249 		goto out_problem;
1250 
1251 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1252 		type = MAP__VARIABLE;
1253 	else
1254 		type = MAP__FUNCTION;
1255 
1256 	map = map__new(machine, event->mmap.start,
1257 			event->mmap.len, event->mmap.pgoff,
1258 			event->mmap.pid, 0, 0, 0, 0, 0, 0,
1259 			event->mmap.filename,
1260 			type, thread);
1261 
1262 	if (map == NULL)
1263 		goto out_problem;
1264 
1265 	thread__insert_map(thread, map);
1266 	return 0;
1267 
1268 out_problem:
1269 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
1270 	return 0;
1271 }
1272 
1273 void machine__remove_thread(struct machine *machine, struct thread *th)
1274 {
1275 	if (machine->last_match == th)
1276 		thread__zput(machine->last_match);
1277 
1278 	rb_erase(&th->rb_node, &machine->threads);
1279 	/*
1280 	 * Move it first to the dead_threads list, then drop the reference,
1281 	 * if this is the last reference, then the thread__delete destructor
1282 	 * will be called and we will remove it from the dead_threads list.
1283 	 */
1284 	list_add_tail(&th->node, &machine->dead_threads);
1285 	thread__put(th);
1286 }
1287 
1288 int machine__process_fork_event(struct machine *machine, union perf_event *event,
1289 				struct perf_sample *sample)
1290 {
1291 	struct thread *thread = machine__find_thread(machine,
1292 						     event->fork.pid,
1293 						     event->fork.tid);
1294 	struct thread *parent = machine__findnew_thread(machine,
1295 							event->fork.ppid,
1296 							event->fork.ptid);
1297 
1298 	/* if a thread currently exists for the thread id remove it */
1299 	if (thread != NULL)
1300 		machine__remove_thread(machine, thread);
1301 
1302 	thread = machine__findnew_thread(machine, event->fork.pid,
1303 					 event->fork.tid);
1304 	if (dump_trace)
1305 		perf_event__fprintf_task(event, stdout);
1306 
1307 	if (thread == NULL || parent == NULL ||
1308 	    thread__fork(thread, parent, sample->time) < 0) {
1309 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
1310 		return -1;
1311 	}
1312 
1313 	return 0;
1314 }
1315 
1316 int machine__process_exit_event(struct machine *machine, union perf_event *event,
1317 				struct perf_sample *sample __maybe_unused)
1318 {
1319 	struct thread *thread = machine__find_thread(machine,
1320 						     event->fork.pid,
1321 						     event->fork.tid);
1322 
1323 	if (dump_trace)
1324 		perf_event__fprintf_task(event, stdout);
1325 
1326 	if (thread != NULL)
1327 		thread__exited(thread);
1328 
1329 	return 0;
1330 }
1331 
1332 int machine__process_event(struct machine *machine, union perf_event *event,
1333 			   struct perf_sample *sample)
1334 {
1335 	int ret;
1336 
1337 	switch (event->header.type) {
1338 	case PERF_RECORD_COMM:
1339 		ret = machine__process_comm_event(machine, event, sample); break;
1340 	case PERF_RECORD_MMAP:
1341 		ret = machine__process_mmap_event(machine, event, sample); break;
1342 	case PERF_RECORD_MMAP2:
1343 		ret = machine__process_mmap2_event(machine, event, sample); break;
1344 	case PERF_RECORD_FORK:
1345 		ret = machine__process_fork_event(machine, event, sample); break;
1346 	case PERF_RECORD_EXIT:
1347 		ret = machine__process_exit_event(machine, event, sample); break;
1348 	case PERF_RECORD_LOST:
1349 		ret = machine__process_lost_event(machine, event, sample); break;
1350 	case PERF_RECORD_AUX:
1351 		ret = machine__process_aux_event(machine, event); break;
1352 	case PERF_RECORD_ITRACE_START:
1353 		ret = machine__process_itrace_start_event(machine, event);
1354 		break;
1355 	default:
1356 		ret = -1;
1357 		break;
1358 	}
1359 
1360 	return ret;
1361 }
1362 
1363 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
1364 {
1365 	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
1366 		return 1;
1367 	return 0;
1368 }
1369 
1370 static void ip__resolve_ams(struct thread *thread,
1371 			    struct addr_map_symbol *ams,
1372 			    u64 ip)
1373 {
1374 	struct addr_location al;
1375 
1376 	memset(&al, 0, sizeof(al));
1377 	/*
1378 	 * We cannot use the header.misc hint to determine whether a
1379 	 * branch stack address is user, kernel, guest, hypervisor.
1380 	 * Branches may straddle the kernel/user/hypervisor boundaries.
1381 	 * Thus, we have to try consecutively until we find a match
1382 	 * or else, the symbol is unknown
1383 	 */
1384 	thread__find_cpumode_addr_location(thread, MAP__FUNCTION, ip, &al);
1385 
1386 	ams->addr = ip;
1387 	ams->al_addr = al.addr;
1388 	ams->sym = al.sym;
1389 	ams->map = al.map;
1390 }
1391 
1392 static void ip__resolve_data(struct thread *thread,
1393 			     u8 m, struct addr_map_symbol *ams, u64 addr)
1394 {
1395 	struct addr_location al;
1396 
1397 	memset(&al, 0, sizeof(al));
1398 
1399 	thread__find_addr_location(thread, m, MAP__VARIABLE, addr, &al);
1400 	if (al.map == NULL) {
1401 		/*
1402 		 * some shared data regions have execute bit set which puts
1403 		 * their mapping in the MAP__FUNCTION type array.
1404 		 * Check there as a fallback option before dropping the sample.
1405 		 */
1406 		thread__find_addr_location(thread, m, MAP__FUNCTION, addr, &al);
1407 	}
1408 
1409 	ams->addr = addr;
1410 	ams->al_addr = al.addr;
1411 	ams->sym = al.sym;
1412 	ams->map = al.map;
1413 }
1414 
1415 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
1416 				     struct addr_location *al)
1417 {
1418 	struct mem_info *mi = zalloc(sizeof(*mi));
1419 
1420 	if (!mi)
1421 		return NULL;
1422 
1423 	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
1424 	ip__resolve_data(al->thread, al->cpumode, &mi->daddr, sample->addr);
1425 	mi->data_src.val = sample->data_src;
1426 
1427 	return mi;
1428 }
1429 
1430 static int add_callchain_ip(struct thread *thread,
1431 			    struct symbol **parent,
1432 			    struct addr_location *root_al,
1433 			    u8 *cpumode,
1434 			    u64 ip)
1435 {
1436 	struct addr_location al;
1437 
1438 	al.filtered = 0;
1439 	al.sym = NULL;
1440 	if (!cpumode) {
1441 		thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
1442 						   ip, &al);
1443 	} else {
1444 		if (ip >= PERF_CONTEXT_MAX) {
1445 			switch (ip) {
1446 			case PERF_CONTEXT_HV:
1447 				*cpumode = PERF_RECORD_MISC_HYPERVISOR;
1448 				break;
1449 			case PERF_CONTEXT_KERNEL:
1450 				*cpumode = PERF_RECORD_MISC_KERNEL;
1451 				break;
1452 			case PERF_CONTEXT_USER:
1453 				*cpumode = PERF_RECORD_MISC_USER;
1454 				break;
1455 			default:
1456 				pr_debug("invalid callchain context: "
1457 					 "%"PRId64"\n", (s64) ip);
1458 				/*
1459 				 * It seems the callchain is corrupted.
1460 				 * Discard all.
1461 				 */
1462 				callchain_cursor_reset(&callchain_cursor);
1463 				return 1;
1464 			}
1465 			return 0;
1466 		}
1467 		thread__find_addr_location(thread, *cpumode, MAP__FUNCTION,
1468 					   ip, &al);
1469 	}
1470 
1471 	if (al.sym != NULL) {
1472 		if (sort__has_parent && !*parent &&
1473 		    symbol__match_regex(al.sym, &parent_regex))
1474 			*parent = al.sym;
1475 		else if (have_ignore_callees && root_al &&
1476 		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
1477 			/* Treat this symbol as the root,
1478 			   forgetting its callees. */
1479 			*root_al = al;
1480 			callchain_cursor_reset(&callchain_cursor);
1481 		}
1482 	}
1483 
1484 	return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);
1485 }
1486 
1487 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
1488 					   struct addr_location *al)
1489 {
1490 	unsigned int i;
1491 	const struct branch_stack *bs = sample->branch_stack;
1492 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
1493 
1494 	if (!bi)
1495 		return NULL;
1496 
1497 	for (i = 0; i < bs->nr; i++) {
1498 		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
1499 		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
1500 		bi[i].flags = bs->entries[i].flags;
1501 	}
1502 	return bi;
1503 }
1504 
1505 #define CHASHSZ 127
1506 #define CHASHBITS 7
1507 #define NO_ENTRY 0xff
1508 
1509 #define PERF_MAX_BRANCH_DEPTH 127
1510 
1511 /* Remove loops. */
1512 static int remove_loops(struct branch_entry *l, int nr)
1513 {
1514 	int i, j, off;
1515 	unsigned char chash[CHASHSZ];
1516 
1517 	memset(chash, NO_ENTRY, sizeof(chash));
1518 
1519 	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
1520 
1521 	for (i = 0; i < nr; i++) {
1522 		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
1523 
1524 		/* no collision handling for now */
1525 		if (chash[h] == NO_ENTRY) {
1526 			chash[h] = i;
1527 		} else if (l[chash[h]].from == l[i].from) {
1528 			bool is_loop = true;
1529 			/* check if it is a real loop */
1530 			off = 0;
1531 			for (j = chash[h]; j < i && i + off < nr; j++, off++)
1532 				if (l[j].from != l[i + off].from) {
1533 					is_loop = false;
1534 					break;
1535 				}
1536 			if (is_loop) {
1537 				memmove(l + i, l + i + off,
1538 					(nr - (i + off)) * sizeof(*l));
1539 				nr -= off;
1540 			}
1541 		}
1542 	}
1543 	return nr;
1544 }
1545 
1546 /*
1547  * Recolve LBR callstack chain sample
1548  * Return:
1549  * 1 on success get LBR callchain information
1550  * 0 no available LBR callchain information, should try fp
1551  * negative error code on other errors.
1552  */
1553 static int resolve_lbr_callchain_sample(struct thread *thread,
1554 					struct perf_sample *sample,
1555 					struct symbol **parent,
1556 					struct addr_location *root_al,
1557 					int max_stack)
1558 {
1559 	struct ip_callchain *chain = sample->callchain;
1560 	int chain_nr = min(max_stack, (int)chain->nr);
1561 	u8 cpumode = PERF_RECORD_MISC_USER;
1562 	int i, j, err;
1563 	u64 ip;
1564 
1565 	for (i = 0; i < chain_nr; i++) {
1566 		if (chain->ips[i] == PERF_CONTEXT_USER)
1567 			break;
1568 	}
1569 
1570 	/* LBR only affects the user callchain */
1571 	if (i != chain_nr) {
1572 		struct branch_stack *lbr_stack = sample->branch_stack;
1573 		int lbr_nr = lbr_stack->nr;
1574 		/*
1575 		 * LBR callstack can only get user call chain.
1576 		 * The mix_chain_nr is kernel call chain
1577 		 * number plus LBR user call chain number.
1578 		 * i is kernel call chain number,
1579 		 * 1 is PERF_CONTEXT_USER,
1580 		 * lbr_nr + 1 is the user call chain number.
1581 		 * For details, please refer to the comments
1582 		 * in callchain__printf
1583 		 */
1584 		int mix_chain_nr = i + 1 + lbr_nr + 1;
1585 
1586 		if (mix_chain_nr > PERF_MAX_STACK_DEPTH + PERF_MAX_BRANCH_DEPTH) {
1587 			pr_warning("corrupted callchain. skipping...\n");
1588 			return 0;
1589 		}
1590 
1591 		for (j = 0; j < mix_chain_nr; j++) {
1592 			if (callchain_param.order == ORDER_CALLEE) {
1593 				if (j < i + 1)
1594 					ip = chain->ips[j];
1595 				else if (j > i + 1)
1596 					ip = lbr_stack->entries[j - i - 2].from;
1597 				else
1598 					ip = lbr_stack->entries[0].to;
1599 			} else {
1600 				if (j < lbr_nr)
1601 					ip = lbr_stack->entries[lbr_nr - j - 1].from;
1602 				else if (j > lbr_nr)
1603 					ip = chain->ips[i + 1 - (j - lbr_nr)];
1604 				else
1605 					ip = lbr_stack->entries[0].to;
1606 			}
1607 
1608 			err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
1609 			if (err)
1610 				return (err < 0) ? err : 0;
1611 		}
1612 		return 1;
1613 	}
1614 
1615 	return 0;
1616 }
1617 
1618 static int thread__resolve_callchain_sample(struct thread *thread,
1619 					    struct perf_evsel *evsel,
1620 					    struct perf_sample *sample,
1621 					    struct symbol **parent,
1622 					    struct addr_location *root_al,
1623 					    int max_stack)
1624 {
1625 	struct branch_stack *branch = sample->branch_stack;
1626 	struct ip_callchain *chain = sample->callchain;
1627 	int chain_nr = min(max_stack, (int)chain->nr);
1628 	u8 cpumode = PERF_RECORD_MISC_USER;
1629 	int i, j, err;
1630 	int skip_idx = -1;
1631 	int first_call = 0;
1632 
1633 	callchain_cursor_reset(&callchain_cursor);
1634 
1635 	if (has_branch_callstack(evsel)) {
1636 		err = resolve_lbr_callchain_sample(thread, sample, parent,
1637 						   root_al, max_stack);
1638 		if (err)
1639 			return (err < 0) ? err : 0;
1640 	}
1641 
1642 	/*
1643 	 * Based on DWARF debug information, some architectures skip
1644 	 * a callchain entry saved by the kernel.
1645 	 */
1646 	if (chain->nr < PERF_MAX_STACK_DEPTH)
1647 		skip_idx = arch_skip_callchain_idx(thread, chain);
1648 
1649 	/*
1650 	 * Add branches to call stack for easier browsing. This gives
1651 	 * more context for a sample than just the callers.
1652 	 *
1653 	 * This uses individual histograms of paths compared to the
1654 	 * aggregated histograms the normal LBR mode uses.
1655 	 *
1656 	 * Limitations for now:
1657 	 * - No extra filters
1658 	 * - No annotations (should annotate somehow)
1659 	 */
1660 
1661 	if (branch && callchain_param.branch_callstack) {
1662 		int nr = min(max_stack, (int)branch->nr);
1663 		struct branch_entry be[nr];
1664 
1665 		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
1666 			pr_warning("corrupted branch chain. skipping...\n");
1667 			goto check_calls;
1668 		}
1669 
1670 		for (i = 0; i < nr; i++) {
1671 			if (callchain_param.order == ORDER_CALLEE) {
1672 				be[i] = branch->entries[i];
1673 				/*
1674 				 * Check for overlap into the callchain.
1675 				 * The return address is one off compared to
1676 				 * the branch entry. To adjust for this
1677 				 * assume the calling instruction is not longer
1678 				 * than 8 bytes.
1679 				 */
1680 				if (i == skip_idx ||
1681 				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
1682 					first_call++;
1683 				else if (be[i].from < chain->ips[first_call] &&
1684 				    be[i].from >= chain->ips[first_call] - 8)
1685 					first_call++;
1686 			} else
1687 				be[i] = branch->entries[branch->nr - i - 1];
1688 		}
1689 
1690 		nr = remove_loops(be, nr);
1691 
1692 		for (i = 0; i < nr; i++) {
1693 			err = add_callchain_ip(thread, parent, root_al,
1694 					       NULL, be[i].to);
1695 			if (!err)
1696 				err = add_callchain_ip(thread, parent, root_al,
1697 						       NULL, be[i].from);
1698 			if (err == -EINVAL)
1699 				break;
1700 			if (err)
1701 				return err;
1702 		}
1703 		chain_nr -= nr;
1704 	}
1705 
1706 check_calls:
1707 	if (chain->nr > PERF_MAX_STACK_DEPTH) {
1708 		pr_warning("corrupted callchain. skipping...\n");
1709 		return 0;
1710 	}
1711 
1712 	for (i = first_call; i < chain_nr; i++) {
1713 		u64 ip;
1714 
1715 		if (callchain_param.order == ORDER_CALLEE)
1716 			j = i;
1717 		else
1718 			j = chain->nr - i - 1;
1719 
1720 #ifdef HAVE_SKIP_CALLCHAIN_IDX
1721 		if (j == skip_idx)
1722 			continue;
1723 #endif
1724 		ip = chain->ips[j];
1725 
1726 		err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
1727 
1728 		if (err)
1729 			return (err < 0) ? err : 0;
1730 	}
1731 
1732 	return 0;
1733 }
1734 
1735 static int unwind_entry(struct unwind_entry *entry, void *arg)
1736 {
1737 	struct callchain_cursor *cursor = arg;
1738 	return callchain_cursor_append(cursor, entry->ip,
1739 				       entry->map, entry->sym);
1740 }
1741 
1742 int thread__resolve_callchain(struct thread *thread,
1743 			      struct perf_evsel *evsel,
1744 			      struct perf_sample *sample,
1745 			      struct symbol **parent,
1746 			      struct addr_location *root_al,
1747 			      int max_stack)
1748 {
1749 	int ret = thread__resolve_callchain_sample(thread, evsel,
1750 						   sample, parent,
1751 						   root_al, max_stack);
1752 	if (ret)
1753 		return ret;
1754 
1755 	/* Can we do dwarf post unwind? */
1756 	if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
1757 	      (evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
1758 		return 0;
1759 
1760 	/* Bail out if nothing was captured. */
1761 	if ((!sample->user_regs.regs) ||
1762 	    (!sample->user_stack.size))
1763 		return 0;
1764 
1765 	return unwind__get_entries(unwind_entry, &callchain_cursor,
1766 				   thread, sample, max_stack);
1767 
1768 }
1769 
1770 int machine__for_each_thread(struct machine *machine,
1771 			     int (*fn)(struct thread *thread, void *p),
1772 			     void *priv)
1773 {
1774 	struct rb_node *nd;
1775 	struct thread *thread;
1776 	int rc = 0;
1777 
1778 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
1779 		thread = rb_entry(nd, struct thread, rb_node);
1780 		rc = fn(thread, priv);
1781 		if (rc != 0)
1782 			return rc;
1783 	}
1784 
1785 	list_for_each_entry(thread, &machine->dead_threads, node) {
1786 		rc = fn(thread, priv);
1787 		if (rc != 0)
1788 			return rc;
1789 	}
1790 	return rc;
1791 }
1792 
1793 int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
1794 				  struct target *target, struct thread_map *threads,
1795 				  perf_event__handler_t process, bool data_mmap)
1796 {
1797 	if (target__has_task(target))
1798 		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
1799 	else if (target__has_cpu(target))
1800 		return perf_event__synthesize_threads(tool, process, machine, data_mmap);
1801 	/* command specified */
1802 	return 0;
1803 }
1804 
1805 pid_t machine__get_current_tid(struct machine *machine, int cpu)
1806 {
1807 	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
1808 		return -1;
1809 
1810 	return machine->current_tid[cpu];
1811 }
1812 
1813 int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
1814 			     pid_t tid)
1815 {
1816 	struct thread *thread;
1817 
1818 	if (cpu < 0)
1819 		return -EINVAL;
1820 
1821 	if (!machine->current_tid) {
1822 		int i;
1823 
1824 		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
1825 		if (!machine->current_tid)
1826 			return -ENOMEM;
1827 		for (i = 0; i < MAX_NR_CPUS; i++)
1828 			machine->current_tid[i] = -1;
1829 	}
1830 
1831 	if (cpu >= MAX_NR_CPUS) {
1832 		pr_err("Requested CPU %d too large. ", cpu);
1833 		pr_err("Consider raising MAX_NR_CPUS\n");
1834 		return -EINVAL;
1835 	}
1836 
1837 	machine->current_tid[cpu] = tid;
1838 
1839 	thread = machine__findnew_thread(machine, pid, tid);
1840 	if (!thread)
1841 		return -ENOMEM;
1842 
1843 	thread->cpu = cpu;
1844 
1845 	return 0;
1846 }
1847 
1848 int machine__get_kernel_start(struct machine *machine)
1849 {
1850 	struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
1851 	int err = 0;
1852 
1853 	/*
1854 	 * The only addresses above 2^63 are kernel addresses of a 64-bit
1855 	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
1856 	 * all addresses including kernel addresses are less than 2^32.  In
1857 	 * that case (32-bit system), if the kernel mapping is unknown, all
1858 	 * addresses will be assumed to be in user space - see
1859 	 * machine__kernel_ip().
1860 	 */
1861 	machine->kernel_start = 1ULL << 63;
1862 	if (map) {
1863 		err = map__load(map, machine->symbol_filter);
1864 		if (map->start)
1865 			machine->kernel_start = map->start;
1866 	}
1867 	return err;
1868 }
1869