xref: /linux/tools/perf/util/machine.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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_dead_threads(struct machine *machine)
93 {
94 	struct thread *n, *t;
95 
96 	list_for_each_entry_safe(t, n, &machine->dead_threads, node) {
97 		list_del(&t->node);
98 		thread__delete(t);
99 	}
100 }
101 
102 void machine__delete_threads(struct machine *machine)
103 {
104 	struct rb_node *nd = rb_first(&machine->threads);
105 
106 	while (nd) {
107 		struct thread *t = rb_entry(nd, struct thread, rb_node);
108 
109 		rb_erase(&t->rb_node, &machine->threads);
110 		nd = rb_next(nd);
111 		thread__delete(t);
112 	}
113 }
114 
115 void machine__exit(struct machine *machine)
116 {
117 	map_groups__exit(&machine->kmaps);
118 	dsos__delete(&machine->user_dsos);
119 	dsos__delete(&machine->kernel_dsos);
120 	vdso__exit(machine);
121 	zfree(&machine->root_dir);
122 	zfree(&machine->current_tid);
123 }
124 
125 void machine__delete(struct machine *machine)
126 {
127 	machine__exit(machine);
128 	free(machine);
129 }
130 
131 void machines__init(struct machines *machines)
132 {
133 	machine__init(&machines->host, "", HOST_KERNEL_ID);
134 	machines->guests = RB_ROOT;
135 	machines->symbol_filter = NULL;
136 }
137 
138 void machines__exit(struct machines *machines)
139 {
140 	machine__exit(&machines->host);
141 	/* XXX exit guest */
142 }
143 
144 struct machine *machines__add(struct machines *machines, pid_t pid,
145 			      const char *root_dir)
146 {
147 	struct rb_node **p = &machines->guests.rb_node;
148 	struct rb_node *parent = NULL;
149 	struct machine *pos, *machine = malloc(sizeof(*machine));
150 
151 	if (machine == NULL)
152 		return NULL;
153 
154 	if (machine__init(machine, root_dir, pid) != 0) {
155 		free(machine);
156 		return NULL;
157 	}
158 
159 	machine->symbol_filter = machines->symbol_filter;
160 
161 	while (*p != NULL) {
162 		parent = *p;
163 		pos = rb_entry(parent, struct machine, rb_node);
164 		if (pid < pos->pid)
165 			p = &(*p)->rb_left;
166 		else
167 			p = &(*p)->rb_right;
168 	}
169 
170 	rb_link_node(&machine->rb_node, parent, p);
171 	rb_insert_color(&machine->rb_node, &machines->guests);
172 
173 	return machine;
174 }
175 
176 void machines__set_symbol_filter(struct machines *machines,
177 				 symbol_filter_t symbol_filter)
178 {
179 	struct rb_node *nd;
180 
181 	machines->symbol_filter = symbol_filter;
182 	machines->host.symbol_filter = symbol_filter;
183 
184 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
185 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
186 
187 		machine->symbol_filter = symbol_filter;
188 	}
189 }
190 
191 void machines__set_comm_exec(struct machines *machines, bool comm_exec)
192 {
193 	struct rb_node *nd;
194 
195 	machines->host.comm_exec = comm_exec;
196 
197 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
198 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
199 
200 		machine->comm_exec = comm_exec;
201 	}
202 }
203 
204 struct machine *machines__find(struct machines *machines, pid_t pid)
205 {
206 	struct rb_node **p = &machines->guests.rb_node;
207 	struct rb_node *parent = NULL;
208 	struct machine *machine;
209 	struct machine *default_machine = NULL;
210 
211 	if (pid == HOST_KERNEL_ID)
212 		return &machines->host;
213 
214 	while (*p != NULL) {
215 		parent = *p;
216 		machine = rb_entry(parent, struct machine, rb_node);
217 		if (pid < machine->pid)
218 			p = &(*p)->rb_left;
219 		else if (pid > machine->pid)
220 			p = &(*p)->rb_right;
221 		else
222 			return machine;
223 		if (!machine->pid)
224 			default_machine = machine;
225 	}
226 
227 	return default_machine;
228 }
229 
230 struct machine *machines__findnew(struct machines *machines, pid_t pid)
231 {
232 	char path[PATH_MAX];
233 	const char *root_dir = "";
234 	struct machine *machine = machines__find(machines, pid);
235 
236 	if (machine && (machine->pid == pid))
237 		goto out;
238 
239 	if ((pid != HOST_KERNEL_ID) &&
240 	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
241 	    (symbol_conf.guestmount)) {
242 		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
243 		if (access(path, R_OK)) {
244 			static struct strlist *seen;
245 
246 			if (!seen)
247 				seen = strlist__new(true, NULL);
248 
249 			if (!strlist__has_entry(seen, path)) {
250 				pr_err("Can't access file %s\n", path);
251 				strlist__add(seen, path);
252 			}
253 			machine = NULL;
254 			goto out;
255 		}
256 		root_dir = path;
257 	}
258 
259 	machine = machines__add(machines, pid, root_dir);
260 out:
261 	return machine;
262 }
263 
264 void machines__process_guests(struct machines *machines,
265 			      machine__process_t process, void *data)
266 {
267 	struct rb_node *nd;
268 
269 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
270 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
271 		process(pos, data);
272 	}
273 }
274 
275 char *machine__mmap_name(struct machine *machine, char *bf, size_t size)
276 {
277 	if (machine__is_host(machine))
278 		snprintf(bf, size, "[%s]", "kernel.kallsyms");
279 	else if (machine__is_default_guest(machine))
280 		snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
281 	else {
282 		snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms",
283 			 machine->pid);
284 	}
285 
286 	return bf;
287 }
288 
289 void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size)
290 {
291 	struct rb_node *node;
292 	struct machine *machine;
293 
294 	machines->host.id_hdr_size = id_hdr_size;
295 
296 	for (node = rb_first(&machines->guests); node; node = rb_next(node)) {
297 		machine = rb_entry(node, struct machine, rb_node);
298 		machine->id_hdr_size = id_hdr_size;
299 	}
300 
301 	return;
302 }
303 
304 static void machine__update_thread_pid(struct machine *machine,
305 				       struct thread *th, pid_t pid)
306 {
307 	struct thread *leader;
308 
309 	if (pid == th->pid_ || pid == -1 || th->pid_ != -1)
310 		return;
311 
312 	th->pid_ = pid;
313 
314 	if (th->pid_ == th->tid)
315 		return;
316 
317 	leader = machine__findnew_thread(machine, th->pid_, th->pid_);
318 	if (!leader)
319 		goto out_err;
320 
321 	if (!leader->mg)
322 		leader->mg = map_groups__new(machine);
323 
324 	if (!leader->mg)
325 		goto out_err;
326 
327 	if (th->mg == leader->mg)
328 		return;
329 
330 	if (th->mg) {
331 		/*
332 		 * Maps are created from MMAP events which provide the pid and
333 		 * tid.  Consequently there never should be any maps on a thread
334 		 * with an unknown pid.  Just print an error if there are.
335 		 */
336 		if (!map_groups__empty(th->mg))
337 			pr_err("Discarding thread maps for %d:%d\n",
338 			       th->pid_, th->tid);
339 		map_groups__delete(th->mg);
340 	}
341 
342 	th->mg = map_groups__get(leader->mg);
343 
344 	return;
345 
346 out_err:
347 	pr_err("Failed to join map groups for %d:%d\n", th->pid_, th->tid);
348 }
349 
350 static struct thread *__machine__findnew_thread(struct machine *machine,
351 						pid_t pid, pid_t tid,
352 						bool create)
353 {
354 	struct rb_node **p = &machine->threads.rb_node;
355 	struct rb_node *parent = NULL;
356 	struct thread *th;
357 
358 	/*
359 	 * Front-end cache - TID lookups come in blocks,
360 	 * so most of the time we dont have to look up
361 	 * the full rbtree:
362 	 */
363 	th = machine->last_match;
364 	if (th && th->tid == tid) {
365 		machine__update_thread_pid(machine, th, pid);
366 		return th;
367 	}
368 
369 	while (*p != NULL) {
370 		parent = *p;
371 		th = rb_entry(parent, struct thread, rb_node);
372 
373 		if (th->tid == tid) {
374 			machine->last_match = th;
375 			machine__update_thread_pid(machine, th, pid);
376 			return th;
377 		}
378 
379 		if (tid < th->tid)
380 			p = &(*p)->rb_left;
381 		else
382 			p = &(*p)->rb_right;
383 	}
384 
385 	if (!create)
386 		return NULL;
387 
388 	th = thread__new(pid, tid);
389 	if (th != NULL) {
390 		rb_link_node(&th->rb_node, parent, p);
391 		rb_insert_color(&th->rb_node, &machine->threads);
392 
393 		/*
394 		 * We have to initialize map_groups separately
395 		 * after rb tree is updated.
396 		 *
397 		 * The reason is that we call machine__findnew_thread
398 		 * within thread__init_map_groups to find the thread
399 		 * leader and that would screwed the rb tree.
400 		 */
401 		if (thread__init_map_groups(th, machine)) {
402 			rb_erase(&th->rb_node, &machine->threads);
403 			thread__delete(th);
404 			return NULL;
405 		}
406 
407 		machine->last_match = th;
408 	}
409 
410 	return th;
411 }
412 
413 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
414 				       pid_t tid)
415 {
416 	return __machine__findnew_thread(machine, pid, tid, true);
417 }
418 
419 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
420 				    pid_t tid)
421 {
422 	return __machine__findnew_thread(machine, pid, tid, false);
423 }
424 
425 struct comm *machine__thread_exec_comm(struct machine *machine,
426 				       struct thread *thread)
427 {
428 	if (machine->comm_exec)
429 		return thread__exec_comm(thread);
430 	else
431 		return thread__comm(thread);
432 }
433 
434 int machine__process_comm_event(struct machine *machine, union perf_event *event,
435 				struct perf_sample *sample)
436 {
437 	struct thread *thread = machine__findnew_thread(machine,
438 							event->comm.pid,
439 							event->comm.tid);
440 	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;
441 
442 	if (exec)
443 		machine->comm_exec = true;
444 
445 	if (dump_trace)
446 		perf_event__fprintf_comm(event, stdout);
447 
448 	if (thread == NULL ||
449 	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {
450 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
451 		return -1;
452 	}
453 
454 	return 0;
455 }
456 
457 int machine__process_lost_event(struct machine *machine __maybe_unused,
458 				union perf_event *event, struct perf_sample *sample __maybe_unused)
459 {
460 	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
461 		    event->lost.id, event->lost.lost);
462 	return 0;
463 }
464 
465 struct map *machine__new_module(struct machine *machine, u64 start,
466 				const char *filename)
467 {
468 	struct map *map;
469 	struct dso *dso = __dsos__findnew(&machine->kernel_dsos, filename);
470 	bool compressed;
471 
472 	if (dso == NULL)
473 		return NULL;
474 
475 	map = map__new2(start, dso, MAP__FUNCTION);
476 	if (map == NULL)
477 		return NULL;
478 
479 	if (machine__is_host(machine))
480 		dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
481 	else
482 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;
483 
484 	/* _KMODULE_COMP should be next to _KMODULE */
485 	if (is_kernel_module(filename, &compressed) && compressed)
486 		dso->symtab_type++;
487 
488 	map_groups__insert(&machine->kmaps, map);
489 	return map;
490 }
491 
492 size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
493 {
494 	struct rb_node *nd;
495 	size_t ret = __dsos__fprintf(&machines->host.kernel_dsos.head, fp) +
496 		     __dsos__fprintf(&machines->host.user_dsos.head, fp);
497 
498 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
499 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
500 		ret += __dsos__fprintf(&pos->kernel_dsos.head, fp);
501 		ret += __dsos__fprintf(&pos->user_dsos.head, fp);
502 	}
503 
504 	return ret;
505 }
506 
507 size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,
508 				     bool (skip)(struct dso *dso, int parm), int parm)
509 {
510 	return __dsos__fprintf_buildid(&m->kernel_dsos.head, fp, skip, parm) +
511 	       __dsos__fprintf_buildid(&m->user_dsos.head, fp, skip, parm);
512 }
513 
514 size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,
515 				     bool (skip)(struct dso *dso, int parm), int parm)
516 {
517 	struct rb_node *nd;
518 	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);
519 
520 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
521 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
522 		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
523 	}
524 	return ret;
525 }
526 
527 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
528 {
529 	int i;
530 	size_t printed = 0;
531 	struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
532 
533 	if (kdso->has_build_id) {
534 		char filename[PATH_MAX];
535 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
536 			printed += fprintf(fp, "[0] %s\n", filename);
537 	}
538 
539 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
540 		printed += fprintf(fp, "[%d] %s\n",
541 				   i + kdso->has_build_id, vmlinux_path[i]);
542 
543 	return printed;
544 }
545 
546 size_t machine__fprintf(struct machine *machine, FILE *fp)
547 {
548 	size_t ret = 0;
549 	struct rb_node *nd;
550 
551 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
552 		struct thread *pos = rb_entry(nd, struct thread, rb_node);
553 
554 		ret += thread__fprintf(pos, fp);
555 	}
556 
557 	return ret;
558 }
559 
560 static struct dso *machine__get_kernel(struct machine *machine)
561 {
562 	const char *vmlinux_name = NULL;
563 	struct dso *kernel;
564 
565 	if (machine__is_host(machine)) {
566 		vmlinux_name = symbol_conf.vmlinux_name;
567 		if (!vmlinux_name)
568 			vmlinux_name = "[kernel.kallsyms]";
569 
570 		kernel = dso__kernel_findnew(machine, vmlinux_name,
571 					     "[kernel]",
572 					     DSO_TYPE_KERNEL);
573 	} else {
574 		char bf[PATH_MAX];
575 
576 		if (machine__is_default_guest(machine))
577 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
578 		if (!vmlinux_name)
579 			vmlinux_name = machine__mmap_name(machine, bf,
580 							  sizeof(bf));
581 
582 		kernel = dso__kernel_findnew(machine, vmlinux_name,
583 					     "[guest.kernel]",
584 					     DSO_TYPE_GUEST_KERNEL);
585 	}
586 
587 	if (kernel != NULL && (!kernel->has_build_id))
588 		dso__read_running_kernel_build_id(kernel, machine);
589 
590 	return kernel;
591 }
592 
593 struct process_args {
594 	u64 start;
595 };
596 
597 static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
598 					   size_t bufsz)
599 {
600 	if (machine__is_default_guest(machine))
601 		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
602 	else
603 		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
604 }
605 
606 const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
607 
608 /* Figure out the start address of kernel map from /proc/kallsyms.
609  * Returns the name of the start symbol in *symbol_name. Pass in NULL as
610  * symbol_name if it's not that important.
611  */
612 static u64 machine__get_running_kernel_start(struct machine *machine,
613 					     const char **symbol_name)
614 {
615 	char filename[PATH_MAX];
616 	int i;
617 	const char *name;
618 	u64 addr = 0;
619 
620 	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
621 
622 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
623 		return 0;
624 
625 	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
626 		addr = kallsyms__get_function_start(filename, name);
627 		if (addr)
628 			break;
629 	}
630 
631 	if (symbol_name)
632 		*symbol_name = name;
633 
634 	return addr;
635 }
636 
637 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
638 {
639 	enum map_type type;
640 	u64 start = machine__get_running_kernel_start(machine, NULL);
641 
642 	for (type = 0; type < MAP__NR_TYPES; ++type) {
643 		struct kmap *kmap;
644 
645 		machine->vmlinux_maps[type] = map__new2(start, kernel, type);
646 		if (machine->vmlinux_maps[type] == NULL)
647 			return -1;
648 
649 		machine->vmlinux_maps[type]->map_ip =
650 			machine->vmlinux_maps[type]->unmap_ip =
651 				identity__map_ip;
652 		kmap = map__kmap(machine->vmlinux_maps[type]);
653 		kmap->kmaps = &machine->kmaps;
654 		map_groups__insert(&machine->kmaps,
655 				   machine->vmlinux_maps[type]);
656 	}
657 
658 	return 0;
659 }
660 
661 void machine__destroy_kernel_maps(struct machine *machine)
662 {
663 	enum map_type type;
664 
665 	for (type = 0; type < MAP__NR_TYPES; ++type) {
666 		struct kmap *kmap;
667 
668 		if (machine->vmlinux_maps[type] == NULL)
669 			continue;
670 
671 		kmap = map__kmap(machine->vmlinux_maps[type]);
672 		map_groups__remove(&machine->kmaps,
673 				   machine->vmlinux_maps[type]);
674 		if (kmap->ref_reloc_sym) {
675 			/*
676 			 * ref_reloc_sym is shared among all maps, so free just
677 			 * on one of them.
678 			 */
679 			if (type == MAP__FUNCTION) {
680 				zfree((char **)&kmap->ref_reloc_sym->name);
681 				zfree(&kmap->ref_reloc_sym);
682 			} else
683 				kmap->ref_reloc_sym = NULL;
684 		}
685 
686 		map__delete(machine->vmlinux_maps[type]);
687 		machine->vmlinux_maps[type] = NULL;
688 	}
689 }
690 
691 int machines__create_guest_kernel_maps(struct machines *machines)
692 {
693 	int ret = 0;
694 	struct dirent **namelist = NULL;
695 	int i, items = 0;
696 	char path[PATH_MAX];
697 	pid_t pid;
698 	char *endp;
699 
700 	if (symbol_conf.default_guest_vmlinux_name ||
701 	    symbol_conf.default_guest_modules ||
702 	    symbol_conf.default_guest_kallsyms) {
703 		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
704 	}
705 
706 	if (symbol_conf.guestmount) {
707 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
708 		if (items <= 0)
709 			return -ENOENT;
710 		for (i = 0; i < items; i++) {
711 			if (!isdigit(namelist[i]->d_name[0])) {
712 				/* Filter out . and .. */
713 				continue;
714 			}
715 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
716 			if ((*endp != '\0') ||
717 			    (endp == namelist[i]->d_name) ||
718 			    (errno == ERANGE)) {
719 				pr_debug("invalid directory (%s). Skipping.\n",
720 					 namelist[i]->d_name);
721 				continue;
722 			}
723 			sprintf(path, "%s/%s/proc/kallsyms",
724 				symbol_conf.guestmount,
725 				namelist[i]->d_name);
726 			ret = access(path, R_OK);
727 			if (ret) {
728 				pr_debug("Can't access file %s\n", path);
729 				goto failure;
730 			}
731 			machines__create_kernel_maps(machines, pid);
732 		}
733 failure:
734 		free(namelist);
735 	}
736 
737 	return ret;
738 }
739 
740 void machines__destroy_kernel_maps(struct machines *machines)
741 {
742 	struct rb_node *next = rb_first(&machines->guests);
743 
744 	machine__destroy_kernel_maps(&machines->host);
745 
746 	while (next) {
747 		struct machine *pos = rb_entry(next, struct machine, rb_node);
748 
749 		next = rb_next(&pos->rb_node);
750 		rb_erase(&pos->rb_node, &machines->guests);
751 		machine__delete(pos);
752 	}
753 }
754 
755 int machines__create_kernel_maps(struct machines *machines, pid_t pid)
756 {
757 	struct machine *machine = machines__findnew(machines, pid);
758 
759 	if (machine == NULL)
760 		return -1;
761 
762 	return machine__create_kernel_maps(machine);
763 }
764 
765 int machine__load_kallsyms(struct machine *machine, const char *filename,
766 			   enum map_type type, symbol_filter_t filter)
767 {
768 	struct map *map = machine->vmlinux_maps[type];
769 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
770 
771 	if (ret > 0) {
772 		dso__set_loaded(map->dso, type);
773 		/*
774 		 * Since /proc/kallsyms will have multiple sessions for the
775 		 * kernel, with modules between them, fixup the end of all
776 		 * sections.
777 		 */
778 		__map_groups__fixup_end(&machine->kmaps, type);
779 	}
780 
781 	return ret;
782 }
783 
784 int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
785 			       symbol_filter_t filter)
786 {
787 	struct map *map = machine->vmlinux_maps[type];
788 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
789 
790 	if (ret > 0)
791 		dso__set_loaded(map->dso, type);
792 
793 	return ret;
794 }
795 
796 static void map_groups__fixup_end(struct map_groups *mg)
797 {
798 	int i;
799 	for (i = 0; i < MAP__NR_TYPES; ++i)
800 		__map_groups__fixup_end(mg, i);
801 }
802 
803 static char *get_kernel_version(const char *root_dir)
804 {
805 	char version[PATH_MAX];
806 	FILE *file;
807 	char *name, *tmp;
808 	const char *prefix = "Linux version ";
809 
810 	sprintf(version, "%s/proc/version", root_dir);
811 	file = fopen(version, "r");
812 	if (!file)
813 		return NULL;
814 
815 	version[0] = '\0';
816 	tmp = fgets(version, sizeof(version), file);
817 	fclose(file);
818 
819 	name = strstr(version, prefix);
820 	if (!name)
821 		return NULL;
822 	name += strlen(prefix);
823 	tmp = strchr(name, ' ');
824 	if (tmp)
825 		*tmp = '\0';
826 
827 	return strdup(name);
828 }
829 
830 static int map_groups__set_modules_path_dir(struct map_groups *mg,
831 				const char *dir_name, int depth)
832 {
833 	struct dirent *dent;
834 	DIR *dir = opendir(dir_name);
835 	int ret = 0;
836 
837 	if (!dir) {
838 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
839 		return -1;
840 	}
841 
842 	while ((dent = readdir(dir)) != NULL) {
843 		char path[PATH_MAX];
844 		struct stat st;
845 
846 		/*sshfs might return bad dent->d_type, so we have to stat*/
847 		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
848 		if (stat(path, &st))
849 			continue;
850 
851 		if (S_ISDIR(st.st_mode)) {
852 			if (!strcmp(dent->d_name, ".") ||
853 			    !strcmp(dent->d_name, ".."))
854 				continue;
855 
856 			/* Do not follow top-level source and build symlinks */
857 			if (depth == 0) {
858 				if (!strcmp(dent->d_name, "source") ||
859 				    !strcmp(dent->d_name, "build"))
860 					continue;
861 			}
862 
863 			ret = map_groups__set_modules_path_dir(mg, path,
864 							       depth + 1);
865 			if (ret < 0)
866 				goto out;
867 		} else {
868 			char *dot = strrchr(dent->d_name, '.'),
869 			     dso_name[PATH_MAX];
870 			struct map *map;
871 			char *long_name;
872 
873 			if (dot == NULL)
874 				continue;
875 
876 			/* On some system, modules are compressed like .ko.gz */
877 			if (is_supported_compression(dot + 1) &&
878 			    is_kmodule_extension(dot - 2))
879 				dot -= 3;
880 
881 			snprintf(dso_name, sizeof(dso_name), "[%.*s]",
882 				 (int)(dot - dent->d_name), dent->d_name);
883 
884 			strxfrchar(dso_name, '-', '_');
885 			map = map_groups__find_by_name(mg, MAP__FUNCTION,
886 						       dso_name);
887 			if (map == NULL)
888 				continue;
889 
890 			long_name = strdup(path);
891 			if (long_name == NULL) {
892 				ret = -1;
893 				goto out;
894 			}
895 			dso__set_long_name(map->dso, long_name, true);
896 			dso__kernel_module_get_build_id(map->dso, "");
897 		}
898 	}
899 
900 out:
901 	closedir(dir);
902 	return ret;
903 }
904 
905 static int machine__set_modules_path(struct machine *machine)
906 {
907 	char *version;
908 	char modules_path[PATH_MAX];
909 
910 	version = get_kernel_version(machine->root_dir);
911 	if (!version)
912 		return -1;
913 
914 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",
915 		 machine->root_dir, version);
916 	free(version);
917 
918 	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0);
919 }
920 
921 static int machine__create_module(void *arg, const char *name, u64 start)
922 {
923 	struct machine *machine = arg;
924 	struct map *map;
925 
926 	map = machine__new_module(machine, start, name);
927 	if (map == NULL)
928 		return -1;
929 
930 	dso__kernel_module_get_build_id(map->dso, machine->root_dir);
931 
932 	return 0;
933 }
934 
935 static int machine__create_modules(struct machine *machine)
936 {
937 	const char *modules;
938 	char path[PATH_MAX];
939 
940 	if (machine__is_default_guest(machine)) {
941 		modules = symbol_conf.default_guest_modules;
942 	} else {
943 		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);
944 		modules = path;
945 	}
946 
947 	if (symbol__restricted_filename(modules, "/proc/modules"))
948 		return -1;
949 
950 	if (modules__parse(modules, machine, machine__create_module))
951 		return -1;
952 
953 	if (!machine__set_modules_path(machine))
954 		return 0;
955 
956 	pr_debug("Problems setting modules path maps, continuing anyway...\n");
957 
958 	return 0;
959 }
960 
961 int machine__create_kernel_maps(struct machine *machine)
962 {
963 	struct dso *kernel = machine__get_kernel(machine);
964 	const char *name;
965 	u64 addr = machine__get_running_kernel_start(machine, &name);
966 	if (!addr)
967 		return -1;
968 
969 	if (kernel == NULL ||
970 	    __machine__create_kernel_maps(machine, kernel) < 0)
971 		return -1;
972 
973 	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
974 		if (machine__is_host(machine))
975 			pr_debug("Problems creating module maps, "
976 				 "continuing anyway...\n");
977 		else
978 			pr_debug("Problems creating module maps for guest %d, "
979 				 "continuing anyway...\n", machine->pid);
980 	}
981 
982 	/*
983 	 * Now that we have all the maps created, just set the ->end of them:
984 	 */
985 	map_groups__fixup_end(&machine->kmaps);
986 
987 	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
988 					     addr)) {
989 		machine__destroy_kernel_maps(machine);
990 		return -1;
991 	}
992 
993 	return 0;
994 }
995 
996 static void machine__set_kernel_mmap_len(struct machine *machine,
997 					 union perf_event *event)
998 {
999 	int i;
1000 
1001 	for (i = 0; i < MAP__NR_TYPES; i++) {
1002 		machine->vmlinux_maps[i]->start = event->mmap.start;
1003 		machine->vmlinux_maps[i]->end   = (event->mmap.start +
1004 						   event->mmap.len);
1005 		/*
1006 		 * Be a bit paranoid here, some perf.data file came with
1007 		 * a zero sized synthesized MMAP event for the kernel.
1008 		 */
1009 		if (machine->vmlinux_maps[i]->end == 0)
1010 			machine->vmlinux_maps[i]->end = ~0ULL;
1011 	}
1012 }
1013 
1014 static bool machine__uses_kcore(struct machine *machine)
1015 {
1016 	struct dso *dso;
1017 
1018 	list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1019 		if (dso__is_kcore(dso))
1020 			return true;
1021 	}
1022 
1023 	return false;
1024 }
1025 
1026 static int machine__process_kernel_mmap_event(struct machine *machine,
1027 					      union perf_event *event)
1028 {
1029 	struct map *map;
1030 	char kmmap_prefix[PATH_MAX];
1031 	enum dso_kernel_type kernel_type;
1032 	bool is_kernel_mmap;
1033 
1034 	/* If we have maps from kcore then we do not need or want any others */
1035 	if (machine__uses_kcore(machine))
1036 		return 0;
1037 
1038 	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
1039 	if (machine__is_host(machine))
1040 		kernel_type = DSO_TYPE_KERNEL;
1041 	else
1042 		kernel_type = DSO_TYPE_GUEST_KERNEL;
1043 
1044 	is_kernel_mmap = memcmp(event->mmap.filename,
1045 				kmmap_prefix,
1046 				strlen(kmmap_prefix) - 1) == 0;
1047 	if (event->mmap.filename[0] == '/' ||
1048 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
1049 
1050 		char short_module_name[1024];
1051 		char *name, *dot;
1052 
1053 		if (event->mmap.filename[0] == '/') {
1054 			name = strrchr(event->mmap.filename, '/');
1055 			if (name == NULL)
1056 				goto out_problem;
1057 
1058 			++name; /* skip / */
1059 			dot = strrchr(name, '.');
1060 			if (dot == NULL)
1061 				goto out_problem;
1062 			/* On some system, modules are compressed like .ko.gz */
1063 			if (is_supported_compression(dot + 1))
1064 				dot -= 3;
1065 			if (!is_kmodule_extension(dot + 1))
1066 				goto out_problem;
1067 			snprintf(short_module_name, sizeof(short_module_name),
1068 					"[%.*s]", (int)(dot - name), name);
1069 			strxfrchar(short_module_name, '-', '_');
1070 		} else
1071 			strcpy(short_module_name, event->mmap.filename);
1072 
1073 		map = machine__new_module(machine, event->mmap.start,
1074 					  event->mmap.filename);
1075 		if (map == NULL)
1076 			goto out_problem;
1077 
1078 		name = strdup(short_module_name);
1079 		if (name == NULL)
1080 			goto out_problem;
1081 
1082 		dso__set_short_name(map->dso, name, true);
1083 		map->end = map->start + event->mmap.len;
1084 	} else if (is_kernel_mmap) {
1085 		const char *symbol_name = (event->mmap.filename +
1086 				strlen(kmmap_prefix));
1087 		/*
1088 		 * Should be there already, from the build-id table in
1089 		 * the header.
1090 		 */
1091 		struct dso *kernel = NULL;
1092 		struct dso *dso;
1093 
1094 		list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1095 			if (is_kernel_module(dso->long_name, NULL))
1096 				continue;
1097 
1098 			kernel = dso;
1099 			break;
1100 		}
1101 
1102 		if (kernel == NULL)
1103 			kernel = __dsos__findnew(&machine->kernel_dsos,
1104 						 kmmap_prefix);
1105 		if (kernel == NULL)
1106 			goto out_problem;
1107 
1108 		kernel->kernel = kernel_type;
1109 		if (__machine__create_kernel_maps(machine, kernel) < 0)
1110 			goto out_problem;
1111 
1112 		if (strstr(kernel->long_name, "vmlinux"))
1113 			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
1114 
1115 		machine__set_kernel_mmap_len(machine, event);
1116 
1117 		/*
1118 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
1119 		 * symbol. Effectively having zero here means that at record
1120 		 * time /proc/sys/kernel/kptr_restrict was non zero.
1121 		 */
1122 		if (event->mmap.pgoff != 0) {
1123 			maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
1124 							 symbol_name,
1125 							 event->mmap.pgoff);
1126 		}
1127 
1128 		if (machine__is_default_guest(machine)) {
1129 			/*
1130 			 * preload dso of guest kernel and modules
1131 			 */
1132 			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
1133 				  NULL);
1134 		}
1135 	}
1136 	return 0;
1137 out_problem:
1138 	return -1;
1139 }
1140 
1141 int machine__process_mmap2_event(struct machine *machine,
1142 				 union perf_event *event,
1143 				 struct perf_sample *sample __maybe_unused)
1144 {
1145 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1146 	struct thread *thread;
1147 	struct map *map;
1148 	enum map_type type;
1149 	int ret = 0;
1150 
1151 	if (dump_trace)
1152 		perf_event__fprintf_mmap2(event, stdout);
1153 
1154 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1155 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1156 		ret = machine__process_kernel_mmap_event(machine, event);
1157 		if (ret < 0)
1158 			goto out_problem;
1159 		return 0;
1160 	}
1161 
1162 	thread = machine__findnew_thread(machine, event->mmap2.pid,
1163 					event->mmap2.tid);
1164 	if (thread == NULL)
1165 		goto out_problem;
1166 
1167 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1168 		type = MAP__VARIABLE;
1169 	else
1170 		type = MAP__FUNCTION;
1171 
1172 	map = map__new(machine, event->mmap2.start,
1173 			event->mmap2.len, event->mmap2.pgoff,
1174 			event->mmap2.pid, event->mmap2.maj,
1175 			event->mmap2.min, event->mmap2.ino,
1176 			event->mmap2.ino_generation,
1177 			event->mmap2.prot,
1178 			event->mmap2.flags,
1179 			event->mmap2.filename, type, thread);
1180 
1181 	if (map == NULL)
1182 		goto out_problem;
1183 
1184 	thread__insert_map(thread, map);
1185 	return 0;
1186 
1187 out_problem:
1188 	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
1189 	return 0;
1190 }
1191 
1192 int machine__process_mmap_event(struct machine *machine, union perf_event *event,
1193 				struct perf_sample *sample __maybe_unused)
1194 {
1195 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1196 	struct thread *thread;
1197 	struct map *map;
1198 	enum map_type type;
1199 	int ret = 0;
1200 
1201 	if (dump_trace)
1202 		perf_event__fprintf_mmap(event, stdout);
1203 
1204 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1205 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1206 		ret = machine__process_kernel_mmap_event(machine, event);
1207 		if (ret < 0)
1208 			goto out_problem;
1209 		return 0;
1210 	}
1211 
1212 	thread = machine__findnew_thread(machine, event->mmap.pid,
1213 					 event->mmap.tid);
1214 	if (thread == NULL)
1215 		goto out_problem;
1216 
1217 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1218 		type = MAP__VARIABLE;
1219 	else
1220 		type = MAP__FUNCTION;
1221 
1222 	map = map__new(machine, event->mmap.start,
1223 			event->mmap.len, event->mmap.pgoff,
1224 			event->mmap.pid, 0, 0, 0, 0, 0, 0,
1225 			event->mmap.filename,
1226 			type, thread);
1227 
1228 	if (map == NULL)
1229 		goto out_problem;
1230 
1231 	thread__insert_map(thread, map);
1232 	return 0;
1233 
1234 out_problem:
1235 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
1236 	return 0;
1237 }
1238 
1239 static void machine__remove_thread(struct machine *machine, struct thread *th)
1240 {
1241 	machine->last_match = NULL;
1242 	rb_erase(&th->rb_node, &machine->threads);
1243 	/*
1244 	 * We may have references to this thread, for instance in some hist_entry
1245 	 * instances, so just move them to a separate list.
1246 	 */
1247 	list_add_tail(&th->node, &machine->dead_threads);
1248 }
1249 
1250 int machine__process_fork_event(struct machine *machine, union perf_event *event,
1251 				struct perf_sample *sample)
1252 {
1253 	struct thread *thread = machine__find_thread(machine,
1254 						     event->fork.pid,
1255 						     event->fork.tid);
1256 	struct thread *parent = machine__findnew_thread(machine,
1257 							event->fork.ppid,
1258 							event->fork.ptid);
1259 
1260 	/* if a thread currently exists for the thread id remove it */
1261 	if (thread != NULL)
1262 		machine__remove_thread(machine, thread);
1263 
1264 	thread = machine__findnew_thread(machine, event->fork.pid,
1265 					 event->fork.tid);
1266 	if (dump_trace)
1267 		perf_event__fprintf_task(event, stdout);
1268 
1269 	if (thread == NULL || parent == NULL ||
1270 	    thread__fork(thread, parent, sample->time) < 0) {
1271 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
1272 		return -1;
1273 	}
1274 
1275 	return 0;
1276 }
1277 
1278 int machine__process_exit_event(struct machine *machine, union perf_event *event,
1279 				struct perf_sample *sample __maybe_unused)
1280 {
1281 	struct thread *thread = machine__find_thread(machine,
1282 						     event->fork.pid,
1283 						     event->fork.tid);
1284 
1285 	if (dump_trace)
1286 		perf_event__fprintf_task(event, stdout);
1287 
1288 	if (thread != NULL)
1289 		thread__exited(thread);
1290 
1291 	return 0;
1292 }
1293 
1294 int machine__process_event(struct machine *machine, union perf_event *event,
1295 			   struct perf_sample *sample)
1296 {
1297 	int ret;
1298 
1299 	switch (event->header.type) {
1300 	case PERF_RECORD_COMM:
1301 		ret = machine__process_comm_event(machine, event, sample); break;
1302 	case PERF_RECORD_MMAP:
1303 		ret = machine__process_mmap_event(machine, event, sample); break;
1304 	case PERF_RECORD_MMAP2:
1305 		ret = machine__process_mmap2_event(machine, event, sample); break;
1306 	case PERF_RECORD_FORK:
1307 		ret = machine__process_fork_event(machine, event, sample); break;
1308 	case PERF_RECORD_EXIT:
1309 		ret = machine__process_exit_event(machine, event, sample); break;
1310 	case PERF_RECORD_LOST:
1311 		ret = machine__process_lost_event(machine, event, sample); break;
1312 	default:
1313 		ret = -1;
1314 		break;
1315 	}
1316 
1317 	return ret;
1318 }
1319 
1320 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
1321 {
1322 	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
1323 		return 1;
1324 	return 0;
1325 }
1326 
1327 static void ip__resolve_ams(struct thread *thread,
1328 			    struct addr_map_symbol *ams,
1329 			    u64 ip)
1330 {
1331 	struct addr_location al;
1332 
1333 	memset(&al, 0, sizeof(al));
1334 	/*
1335 	 * We cannot use the header.misc hint to determine whether a
1336 	 * branch stack address is user, kernel, guest, hypervisor.
1337 	 * Branches may straddle the kernel/user/hypervisor boundaries.
1338 	 * Thus, we have to try consecutively until we find a match
1339 	 * or else, the symbol is unknown
1340 	 */
1341 	thread__find_cpumode_addr_location(thread, MAP__FUNCTION, ip, &al);
1342 
1343 	ams->addr = ip;
1344 	ams->al_addr = al.addr;
1345 	ams->sym = al.sym;
1346 	ams->map = al.map;
1347 }
1348 
1349 static void ip__resolve_data(struct thread *thread,
1350 			     u8 m, struct addr_map_symbol *ams, u64 addr)
1351 {
1352 	struct addr_location al;
1353 
1354 	memset(&al, 0, sizeof(al));
1355 
1356 	thread__find_addr_location(thread, m, MAP__VARIABLE, addr, &al);
1357 	if (al.map == NULL) {
1358 		/*
1359 		 * some shared data regions have execute bit set which puts
1360 		 * their mapping in the MAP__FUNCTION type array.
1361 		 * Check there as a fallback option before dropping the sample.
1362 		 */
1363 		thread__find_addr_location(thread, m, MAP__FUNCTION, addr, &al);
1364 	}
1365 
1366 	ams->addr = addr;
1367 	ams->al_addr = al.addr;
1368 	ams->sym = al.sym;
1369 	ams->map = al.map;
1370 }
1371 
1372 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
1373 				     struct addr_location *al)
1374 {
1375 	struct mem_info *mi = zalloc(sizeof(*mi));
1376 
1377 	if (!mi)
1378 		return NULL;
1379 
1380 	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
1381 	ip__resolve_data(al->thread, al->cpumode, &mi->daddr, sample->addr);
1382 	mi->data_src.val = sample->data_src;
1383 
1384 	return mi;
1385 }
1386 
1387 static int add_callchain_ip(struct thread *thread,
1388 			    struct symbol **parent,
1389 			    struct addr_location *root_al,
1390 			    bool branch_history,
1391 			    u64 ip)
1392 {
1393 	struct addr_location al;
1394 
1395 	al.filtered = 0;
1396 	al.sym = NULL;
1397 	if (branch_history)
1398 		thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
1399 						   ip, &al);
1400 	else {
1401 		u8 cpumode = PERF_RECORD_MISC_USER;
1402 
1403 		if (ip >= PERF_CONTEXT_MAX) {
1404 			switch (ip) {
1405 			case PERF_CONTEXT_HV:
1406 				cpumode = PERF_RECORD_MISC_HYPERVISOR;
1407 				break;
1408 			case PERF_CONTEXT_KERNEL:
1409 				cpumode = PERF_RECORD_MISC_KERNEL;
1410 				break;
1411 			case PERF_CONTEXT_USER:
1412 				cpumode = PERF_RECORD_MISC_USER;
1413 				break;
1414 			default:
1415 				pr_debug("invalid callchain context: "
1416 					 "%"PRId64"\n", (s64) ip);
1417 				/*
1418 				 * It seems the callchain is corrupted.
1419 				 * Discard all.
1420 				 */
1421 				callchain_cursor_reset(&callchain_cursor);
1422 				return 1;
1423 			}
1424 			return 0;
1425 		}
1426 		thread__find_addr_location(thread, cpumode, MAP__FUNCTION,
1427 				   ip, &al);
1428 	}
1429 
1430 	if (al.sym != NULL) {
1431 		if (sort__has_parent && !*parent &&
1432 		    symbol__match_regex(al.sym, &parent_regex))
1433 			*parent = al.sym;
1434 		else if (have_ignore_callees && root_al &&
1435 		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
1436 			/* Treat this symbol as the root,
1437 			   forgetting its callees. */
1438 			*root_al = al;
1439 			callchain_cursor_reset(&callchain_cursor);
1440 		}
1441 	}
1442 
1443 	return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);
1444 }
1445 
1446 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
1447 					   struct addr_location *al)
1448 {
1449 	unsigned int i;
1450 	const struct branch_stack *bs = sample->branch_stack;
1451 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
1452 
1453 	if (!bi)
1454 		return NULL;
1455 
1456 	for (i = 0; i < bs->nr; i++) {
1457 		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
1458 		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
1459 		bi[i].flags = bs->entries[i].flags;
1460 	}
1461 	return bi;
1462 }
1463 
1464 #define CHASHSZ 127
1465 #define CHASHBITS 7
1466 #define NO_ENTRY 0xff
1467 
1468 #define PERF_MAX_BRANCH_DEPTH 127
1469 
1470 /* Remove loops. */
1471 static int remove_loops(struct branch_entry *l, int nr)
1472 {
1473 	int i, j, off;
1474 	unsigned char chash[CHASHSZ];
1475 
1476 	memset(chash, NO_ENTRY, sizeof(chash));
1477 
1478 	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
1479 
1480 	for (i = 0; i < nr; i++) {
1481 		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
1482 
1483 		/* no collision handling for now */
1484 		if (chash[h] == NO_ENTRY) {
1485 			chash[h] = i;
1486 		} else if (l[chash[h]].from == l[i].from) {
1487 			bool is_loop = true;
1488 			/* check if it is a real loop */
1489 			off = 0;
1490 			for (j = chash[h]; j < i && i + off < nr; j++, off++)
1491 				if (l[j].from != l[i + off].from) {
1492 					is_loop = false;
1493 					break;
1494 				}
1495 			if (is_loop) {
1496 				memmove(l + i, l + i + off,
1497 					(nr - (i + off)) * sizeof(*l));
1498 				nr -= off;
1499 			}
1500 		}
1501 	}
1502 	return nr;
1503 }
1504 
1505 static int thread__resolve_callchain_sample(struct thread *thread,
1506 					     struct ip_callchain *chain,
1507 					     struct branch_stack *branch,
1508 					     struct symbol **parent,
1509 					     struct addr_location *root_al,
1510 					     int max_stack)
1511 {
1512 	int chain_nr = min(max_stack, (int)chain->nr);
1513 	int i, j, err;
1514 	int skip_idx = -1;
1515 	int first_call = 0;
1516 
1517 	/*
1518 	 * Based on DWARF debug information, some architectures skip
1519 	 * a callchain entry saved by the kernel.
1520 	 */
1521 	if (chain->nr < PERF_MAX_STACK_DEPTH)
1522 		skip_idx = arch_skip_callchain_idx(thread, chain);
1523 
1524 	callchain_cursor_reset(&callchain_cursor);
1525 
1526 	/*
1527 	 * Add branches to call stack for easier browsing. This gives
1528 	 * more context for a sample than just the callers.
1529 	 *
1530 	 * This uses individual histograms of paths compared to the
1531 	 * aggregated histograms the normal LBR mode uses.
1532 	 *
1533 	 * Limitations for now:
1534 	 * - No extra filters
1535 	 * - No annotations (should annotate somehow)
1536 	 */
1537 
1538 	if (branch && callchain_param.branch_callstack) {
1539 		int nr = min(max_stack, (int)branch->nr);
1540 		struct branch_entry be[nr];
1541 
1542 		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
1543 			pr_warning("corrupted branch chain. skipping...\n");
1544 			goto check_calls;
1545 		}
1546 
1547 		for (i = 0; i < nr; i++) {
1548 			if (callchain_param.order == ORDER_CALLEE) {
1549 				be[i] = branch->entries[i];
1550 				/*
1551 				 * Check for overlap into the callchain.
1552 				 * The return address is one off compared to
1553 				 * the branch entry. To adjust for this
1554 				 * assume the calling instruction is not longer
1555 				 * than 8 bytes.
1556 				 */
1557 				if (i == skip_idx ||
1558 				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
1559 					first_call++;
1560 				else if (be[i].from < chain->ips[first_call] &&
1561 				    be[i].from >= chain->ips[first_call] - 8)
1562 					first_call++;
1563 			} else
1564 				be[i] = branch->entries[branch->nr - i - 1];
1565 		}
1566 
1567 		nr = remove_loops(be, nr);
1568 
1569 		for (i = 0; i < nr; i++) {
1570 			err = add_callchain_ip(thread, parent, root_al,
1571 					       true, be[i].to);
1572 			if (!err)
1573 				err = add_callchain_ip(thread, parent, root_al,
1574 						       true, be[i].from);
1575 			if (err == -EINVAL)
1576 				break;
1577 			if (err)
1578 				return err;
1579 		}
1580 		chain_nr -= nr;
1581 	}
1582 
1583 check_calls:
1584 	if (chain->nr > PERF_MAX_STACK_DEPTH) {
1585 		pr_warning("corrupted callchain. skipping...\n");
1586 		return 0;
1587 	}
1588 
1589 	for (i = first_call; i < chain_nr; i++) {
1590 		u64 ip;
1591 
1592 		if (callchain_param.order == ORDER_CALLEE)
1593 			j = i;
1594 		else
1595 			j = chain->nr - i - 1;
1596 
1597 #ifdef HAVE_SKIP_CALLCHAIN_IDX
1598 		if (j == skip_idx)
1599 			continue;
1600 #endif
1601 		ip = chain->ips[j];
1602 
1603 		err = add_callchain_ip(thread, parent, root_al, false, ip);
1604 
1605 		if (err)
1606 			return (err < 0) ? err : 0;
1607 	}
1608 
1609 	return 0;
1610 }
1611 
1612 static int unwind_entry(struct unwind_entry *entry, void *arg)
1613 {
1614 	struct callchain_cursor *cursor = arg;
1615 	return callchain_cursor_append(cursor, entry->ip,
1616 				       entry->map, entry->sym);
1617 }
1618 
1619 int thread__resolve_callchain(struct thread *thread,
1620 			      struct perf_evsel *evsel,
1621 			      struct perf_sample *sample,
1622 			      struct symbol **parent,
1623 			      struct addr_location *root_al,
1624 			      int max_stack)
1625 {
1626 	int ret = thread__resolve_callchain_sample(thread, sample->callchain,
1627 						   sample->branch_stack,
1628 						   parent, root_al, max_stack);
1629 	if (ret)
1630 		return ret;
1631 
1632 	/* Can we do dwarf post unwind? */
1633 	if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
1634 	      (evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
1635 		return 0;
1636 
1637 	/* Bail out if nothing was captured. */
1638 	if ((!sample->user_regs.regs) ||
1639 	    (!sample->user_stack.size))
1640 		return 0;
1641 
1642 	return unwind__get_entries(unwind_entry, &callchain_cursor,
1643 				   thread, sample, max_stack);
1644 
1645 }
1646 
1647 int machine__for_each_thread(struct machine *machine,
1648 			     int (*fn)(struct thread *thread, void *p),
1649 			     void *priv)
1650 {
1651 	struct rb_node *nd;
1652 	struct thread *thread;
1653 	int rc = 0;
1654 
1655 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
1656 		thread = rb_entry(nd, struct thread, rb_node);
1657 		rc = fn(thread, priv);
1658 		if (rc != 0)
1659 			return rc;
1660 	}
1661 
1662 	list_for_each_entry(thread, &machine->dead_threads, node) {
1663 		rc = fn(thread, priv);
1664 		if (rc != 0)
1665 			return rc;
1666 	}
1667 	return rc;
1668 }
1669 
1670 int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
1671 				  struct target *target, struct thread_map *threads,
1672 				  perf_event__handler_t process, bool data_mmap)
1673 {
1674 	if (target__has_task(target))
1675 		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
1676 	else if (target__has_cpu(target))
1677 		return perf_event__synthesize_threads(tool, process, machine, data_mmap);
1678 	/* command specified */
1679 	return 0;
1680 }
1681 
1682 pid_t machine__get_current_tid(struct machine *machine, int cpu)
1683 {
1684 	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
1685 		return -1;
1686 
1687 	return machine->current_tid[cpu];
1688 }
1689 
1690 int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
1691 			     pid_t tid)
1692 {
1693 	struct thread *thread;
1694 
1695 	if (cpu < 0)
1696 		return -EINVAL;
1697 
1698 	if (!machine->current_tid) {
1699 		int i;
1700 
1701 		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
1702 		if (!machine->current_tid)
1703 			return -ENOMEM;
1704 		for (i = 0; i < MAX_NR_CPUS; i++)
1705 			machine->current_tid[i] = -1;
1706 	}
1707 
1708 	if (cpu >= MAX_NR_CPUS) {
1709 		pr_err("Requested CPU %d too large. ", cpu);
1710 		pr_err("Consider raising MAX_NR_CPUS\n");
1711 		return -EINVAL;
1712 	}
1713 
1714 	machine->current_tid[cpu] = tid;
1715 
1716 	thread = machine__findnew_thread(machine, pid, tid);
1717 	if (!thread)
1718 		return -ENOMEM;
1719 
1720 	thread->cpu = cpu;
1721 
1722 	return 0;
1723 }
1724 
1725 int machine__get_kernel_start(struct machine *machine)
1726 {
1727 	struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
1728 	int err = 0;
1729 
1730 	/*
1731 	 * The only addresses above 2^63 are kernel addresses of a 64-bit
1732 	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
1733 	 * all addresses including kernel addresses are less than 2^32.  In
1734 	 * that case (32-bit system), if the kernel mapping is unknown, all
1735 	 * addresses will be assumed to be in user space - see
1736 	 * machine__kernel_ip().
1737 	 */
1738 	machine->kernel_start = 1ULL << 63;
1739 	if (map) {
1740 		err = map__load(map, machine->symbol_filter);
1741 		if (map->start)
1742 			machine->kernel_start = map->start;
1743 	}
1744 	return err;
1745 }
1746