xref: /openbmc/linux/tools/perf/util/machine.c (revision 867a0e05)
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 		machine->last_match = th;
393 
394 		/*
395 		 * We have to initialize map_groups separately
396 		 * after rb tree is updated.
397 		 *
398 		 * The reason is that we call machine__findnew_thread
399 		 * within thread__init_map_groups to find the thread
400 		 * leader and that would screwed the rb tree.
401 		 */
402 		if (thread__init_map_groups(th, machine)) {
403 			thread__delete(th);
404 			return NULL;
405 		}
406 	}
407 
408 	return th;
409 }
410 
411 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
412 				       pid_t tid)
413 {
414 	return __machine__findnew_thread(machine, pid, tid, true);
415 }
416 
417 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
418 				    pid_t tid)
419 {
420 	return __machine__findnew_thread(machine, pid, tid, false);
421 }
422 
423 struct comm *machine__thread_exec_comm(struct machine *machine,
424 				       struct thread *thread)
425 {
426 	if (machine->comm_exec)
427 		return thread__exec_comm(thread);
428 	else
429 		return thread__comm(thread);
430 }
431 
432 int machine__process_comm_event(struct machine *machine, union perf_event *event,
433 				struct perf_sample *sample)
434 {
435 	struct thread *thread = machine__findnew_thread(machine,
436 							event->comm.pid,
437 							event->comm.tid);
438 	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;
439 
440 	if (exec)
441 		machine->comm_exec = true;
442 
443 	if (dump_trace)
444 		perf_event__fprintf_comm(event, stdout);
445 
446 	if (thread == NULL ||
447 	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {
448 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
449 		return -1;
450 	}
451 
452 	return 0;
453 }
454 
455 int machine__process_lost_event(struct machine *machine __maybe_unused,
456 				union perf_event *event, struct perf_sample *sample __maybe_unused)
457 {
458 	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
459 		    event->lost.id, event->lost.lost);
460 	return 0;
461 }
462 
463 struct map *machine__new_module(struct machine *machine, u64 start,
464 				const char *filename)
465 {
466 	struct map *map;
467 	struct dso *dso = __dsos__findnew(&machine->kernel_dsos, filename);
468 	bool compressed;
469 
470 	if (dso == NULL)
471 		return NULL;
472 
473 	map = map__new2(start, dso, MAP__FUNCTION);
474 	if (map == NULL)
475 		return NULL;
476 
477 	if (machine__is_host(machine))
478 		dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
479 	else
480 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;
481 
482 	/* _KMODULE_COMP should be next to _KMODULE */
483 	if (is_kernel_module(filename, &compressed) && compressed)
484 		dso->symtab_type++;
485 
486 	map_groups__insert(&machine->kmaps, map);
487 	return map;
488 }
489 
490 size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
491 {
492 	struct rb_node *nd;
493 	size_t ret = __dsos__fprintf(&machines->host.kernel_dsos.head, fp) +
494 		     __dsos__fprintf(&machines->host.user_dsos.head, fp);
495 
496 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
497 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
498 		ret += __dsos__fprintf(&pos->kernel_dsos.head, fp);
499 		ret += __dsos__fprintf(&pos->user_dsos.head, fp);
500 	}
501 
502 	return ret;
503 }
504 
505 size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,
506 				     bool (skip)(struct dso *dso, int parm), int parm)
507 {
508 	return __dsos__fprintf_buildid(&m->kernel_dsos.head, fp, skip, parm) +
509 	       __dsos__fprintf_buildid(&m->user_dsos.head, fp, skip, parm);
510 }
511 
512 size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,
513 				     bool (skip)(struct dso *dso, int parm), int parm)
514 {
515 	struct rb_node *nd;
516 	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);
517 
518 	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
519 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
520 		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
521 	}
522 	return ret;
523 }
524 
525 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
526 {
527 	int i;
528 	size_t printed = 0;
529 	struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
530 
531 	if (kdso->has_build_id) {
532 		char filename[PATH_MAX];
533 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
534 			printed += fprintf(fp, "[0] %s\n", filename);
535 	}
536 
537 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
538 		printed += fprintf(fp, "[%d] %s\n",
539 				   i + kdso->has_build_id, vmlinux_path[i]);
540 
541 	return printed;
542 }
543 
544 size_t machine__fprintf(struct machine *machine, FILE *fp)
545 {
546 	size_t ret = 0;
547 	struct rb_node *nd;
548 
549 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
550 		struct thread *pos = rb_entry(nd, struct thread, rb_node);
551 
552 		ret += thread__fprintf(pos, fp);
553 	}
554 
555 	return ret;
556 }
557 
558 static struct dso *machine__get_kernel(struct machine *machine)
559 {
560 	const char *vmlinux_name = NULL;
561 	struct dso *kernel;
562 
563 	if (machine__is_host(machine)) {
564 		vmlinux_name = symbol_conf.vmlinux_name;
565 		if (!vmlinux_name)
566 			vmlinux_name = "[kernel.kallsyms]";
567 
568 		kernel = dso__kernel_findnew(machine, vmlinux_name,
569 					     "[kernel]",
570 					     DSO_TYPE_KERNEL);
571 	} else {
572 		char bf[PATH_MAX];
573 
574 		if (machine__is_default_guest(machine))
575 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
576 		if (!vmlinux_name)
577 			vmlinux_name = machine__mmap_name(machine, bf,
578 							  sizeof(bf));
579 
580 		kernel = dso__kernel_findnew(machine, vmlinux_name,
581 					     "[guest.kernel]",
582 					     DSO_TYPE_GUEST_KERNEL);
583 	}
584 
585 	if (kernel != NULL && (!kernel->has_build_id))
586 		dso__read_running_kernel_build_id(kernel, machine);
587 
588 	return kernel;
589 }
590 
591 struct process_args {
592 	u64 start;
593 };
594 
595 static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
596 					   size_t bufsz)
597 {
598 	if (machine__is_default_guest(machine))
599 		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
600 	else
601 		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
602 }
603 
604 const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
605 
606 /* Figure out the start address of kernel map from /proc/kallsyms.
607  * Returns the name of the start symbol in *symbol_name. Pass in NULL as
608  * symbol_name if it's not that important.
609  */
610 static u64 machine__get_running_kernel_start(struct machine *machine,
611 					     const char **symbol_name)
612 {
613 	char filename[PATH_MAX];
614 	int i;
615 	const char *name;
616 	u64 addr = 0;
617 
618 	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
619 
620 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
621 		return 0;
622 
623 	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
624 		addr = kallsyms__get_function_start(filename, name);
625 		if (addr)
626 			break;
627 	}
628 
629 	if (symbol_name)
630 		*symbol_name = name;
631 
632 	return addr;
633 }
634 
635 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
636 {
637 	enum map_type type;
638 	u64 start = machine__get_running_kernel_start(machine, NULL);
639 
640 	for (type = 0; type < MAP__NR_TYPES; ++type) {
641 		struct kmap *kmap;
642 
643 		machine->vmlinux_maps[type] = map__new2(start, kernel, type);
644 		if (machine->vmlinux_maps[type] == NULL)
645 			return -1;
646 
647 		machine->vmlinux_maps[type]->map_ip =
648 			machine->vmlinux_maps[type]->unmap_ip =
649 				identity__map_ip;
650 		kmap = map__kmap(machine->vmlinux_maps[type]);
651 		kmap->kmaps = &machine->kmaps;
652 		map_groups__insert(&machine->kmaps,
653 				   machine->vmlinux_maps[type]);
654 	}
655 
656 	return 0;
657 }
658 
659 void machine__destroy_kernel_maps(struct machine *machine)
660 {
661 	enum map_type type;
662 
663 	for (type = 0; type < MAP__NR_TYPES; ++type) {
664 		struct kmap *kmap;
665 
666 		if (machine->vmlinux_maps[type] == NULL)
667 			continue;
668 
669 		kmap = map__kmap(machine->vmlinux_maps[type]);
670 		map_groups__remove(&machine->kmaps,
671 				   machine->vmlinux_maps[type]);
672 		if (kmap->ref_reloc_sym) {
673 			/*
674 			 * ref_reloc_sym is shared among all maps, so free just
675 			 * on one of them.
676 			 */
677 			if (type == MAP__FUNCTION) {
678 				zfree((char **)&kmap->ref_reloc_sym->name);
679 				zfree(&kmap->ref_reloc_sym);
680 			} else
681 				kmap->ref_reloc_sym = NULL;
682 		}
683 
684 		map__delete(machine->vmlinux_maps[type]);
685 		machine->vmlinux_maps[type] = NULL;
686 	}
687 }
688 
689 int machines__create_guest_kernel_maps(struct machines *machines)
690 {
691 	int ret = 0;
692 	struct dirent **namelist = NULL;
693 	int i, items = 0;
694 	char path[PATH_MAX];
695 	pid_t pid;
696 	char *endp;
697 
698 	if (symbol_conf.default_guest_vmlinux_name ||
699 	    symbol_conf.default_guest_modules ||
700 	    symbol_conf.default_guest_kallsyms) {
701 		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
702 	}
703 
704 	if (symbol_conf.guestmount) {
705 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
706 		if (items <= 0)
707 			return -ENOENT;
708 		for (i = 0; i < items; i++) {
709 			if (!isdigit(namelist[i]->d_name[0])) {
710 				/* Filter out . and .. */
711 				continue;
712 			}
713 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
714 			if ((*endp != '\0') ||
715 			    (endp == namelist[i]->d_name) ||
716 			    (errno == ERANGE)) {
717 				pr_debug("invalid directory (%s). Skipping.\n",
718 					 namelist[i]->d_name);
719 				continue;
720 			}
721 			sprintf(path, "%s/%s/proc/kallsyms",
722 				symbol_conf.guestmount,
723 				namelist[i]->d_name);
724 			ret = access(path, R_OK);
725 			if (ret) {
726 				pr_debug("Can't access file %s\n", path);
727 				goto failure;
728 			}
729 			machines__create_kernel_maps(machines, pid);
730 		}
731 failure:
732 		free(namelist);
733 	}
734 
735 	return ret;
736 }
737 
738 void machines__destroy_kernel_maps(struct machines *machines)
739 {
740 	struct rb_node *next = rb_first(&machines->guests);
741 
742 	machine__destroy_kernel_maps(&machines->host);
743 
744 	while (next) {
745 		struct machine *pos = rb_entry(next, struct machine, rb_node);
746 
747 		next = rb_next(&pos->rb_node);
748 		rb_erase(&pos->rb_node, &machines->guests);
749 		machine__delete(pos);
750 	}
751 }
752 
753 int machines__create_kernel_maps(struct machines *machines, pid_t pid)
754 {
755 	struct machine *machine = machines__findnew(machines, pid);
756 
757 	if (machine == NULL)
758 		return -1;
759 
760 	return machine__create_kernel_maps(machine);
761 }
762 
763 int machine__load_kallsyms(struct machine *machine, const char *filename,
764 			   enum map_type type, symbol_filter_t filter)
765 {
766 	struct map *map = machine->vmlinux_maps[type];
767 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
768 
769 	if (ret > 0) {
770 		dso__set_loaded(map->dso, type);
771 		/*
772 		 * Since /proc/kallsyms will have multiple sessions for the
773 		 * kernel, with modules between them, fixup the end of all
774 		 * sections.
775 		 */
776 		__map_groups__fixup_end(&machine->kmaps, type);
777 	}
778 
779 	return ret;
780 }
781 
782 int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
783 			       symbol_filter_t filter)
784 {
785 	struct map *map = machine->vmlinux_maps[type];
786 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
787 
788 	if (ret > 0)
789 		dso__set_loaded(map->dso, type);
790 
791 	return ret;
792 }
793 
794 static void map_groups__fixup_end(struct map_groups *mg)
795 {
796 	int i;
797 	for (i = 0; i < MAP__NR_TYPES; ++i)
798 		__map_groups__fixup_end(mg, i);
799 }
800 
801 static char *get_kernel_version(const char *root_dir)
802 {
803 	char version[PATH_MAX];
804 	FILE *file;
805 	char *name, *tmp;
806 	const char *prefix = "Linux version ";
807 
808 	sprintf(version, "%s/proc/version", root_dir);
809 	file = fopen(version, "r");
810 	if (!file)
811 		return NULL;
812 
813 	version[0] = '\0';
814 	tmp = fgets(version, sizeof(version), file);
815 	fclose(file);
816 
817 	name = strstr(version, prefix);
818 	if (!name)
819 		return NULL;
820 	name += strlen(prefix);
821 	tmp = strchr(name, ' ');
822 	if (tmp)
823 		*tmp = '\0';
824 
825 	return strdup(name);
826 }
827 
828 static int map_groups__set_modules_path_dir(struct map_groups *mg,
829 				const char *dir_name, int depth)
830 {
831 	struct dirent *dent;
832 	DIR *dir = opendir(dir_name);
833 	int ret = 0;
834 
835 	if (!dir) {
836 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
837 		return -1;
838 	}
839 
840 	while ((dent = readdir(dir)) != NULL) {
841 		char path[PATH_MAX];
842 		struct stat st;
843 
844 		/*sshfs might return bad dent->d_type, so we have to stat*/
845 		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
846 		if (stat(path, &st))
847 			continue;
848 
849 		if (S_ISDIR(st.st_mode)) {
850 			if (!strcmp(dent->d_name, ".") ||
851 			    !strcmp(dent->d_name, ".."))
852 				continue;
853 
854 			/* Do not follow top-level source and build symlinks */
855 			if (depth == 0) {
856 				if (!strcmp(dent->d_name, "source") ||
857 				    !strcmp(dent->d_name, "build"))
858 					continue;
859 			}
860 
861 			ret = map_groups__set_modules_path_dir(mg, path,
862 							       depth + 1);
863 			if (ret < 0)
864 				goto out;
865 		} else {
866 			char *dot = strrchr(dent->d_name, '.'),
867 			     dso_name[PATH_MAX];
868 			struct map *map;
869 			char *long_name;
870 
871 			if (dot == NULL)
872 				continue;
873 
874 			/* On some system, modules are compressed like .ko.gz */
875 			if (is_supported_compression(dot + 1) &&
876 			    is_kmodule_extension(dot - 2))
877 				dot -= 3;
878 
879 			snprintf(dso_name, sizeof(dso_name), "[%.*s]",
880 				 (int)(dot - dent->d_name), dent->d_name);
881 
882 			strxfrchar(dso_name, '-', '_');
883 			map = map_groups__find_by_name(mg, MAP__FUNCTION,
884 						       dso_name);
885 			if (map == NULL)
886 				continue;
887 
888 			long_name = strdup(path);
889 			if (long_name == NULL) {
890 				ret = -1;
891 				goto out;
892 			}
893 			dso__set_long_name(map->dso, long_name, true);
894 			dso__kernel_module_get_build_id(map->dso, "");
895 		}
896 	}
897 
898 out:
899 	closedir(dir);
900 	return ret;
901 }
902 
903 static int machine__set_modules_path(struct machine *machine)
904 {
905 	char *version;
906 	char modules_path[PATH_MAX];
907 
908 	version = get_kernel_version(machine->root_dir);
909 	if (!version)
910 		return -1;
911 
912 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",
913 		 machine->root_dir, version);
914 	free(version);
915 
916 	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0);
917 }
918 
919 static int machine__create_module(void *arg, const char *name, u64 start)
920 {
921 	struct machine *machine = arg;
922 	struct map *map;
923 
924 	map = machine__new_module(machine, start, name);
925 	if (map == NULL)
926 		return -1;
927 
928 	dso__kernel_module_get_build_id(map->dso, machine->root_dir);
929 
930 	return 0;
931 }
932 
933 static int machine__create_modules(struct machine *machine)
934 {
935 	const char *modules;
936 	char path[PATH_MAX];
937 
938 	if (machine__is_default_guest(machine)) {
939 		modules = symbol_conf.default_guest_modules;
940 	} else {
941 		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);
942 		modules = path;
943 	}
944 
945 	if (symbol__restricted_filename(modules, "/proc/modules"))
946 		return -1;
947 
948 	if (modules__parse(modules, machine, machine__create_module))
949 		return -1;
950 
951 	if (!machine__set_modules_path(machine))
952 		return 0;
953 
954 	pr_debug("Problems setting modules path maps, continuing anyway...\n");
955 
956 	return 0;
957 }
958 
959 int machine__create_kernel_maps(struct machine *machine)
960 {
961 	struct dso *kernel = machine__get_kernel(machine);
962 	const char *name;
963 	u64 addr = machine__get_running_kernel_start(machine, &name);
964 	if (!addr)
965 		return -1;
966 
967 	if (kernel == NULL ||
968 	    __machine__create_kernel_maps(machine, kernel) < 0)
969 		return -1;
970 
971 	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
972 		if (machine__is_host(machine))
973 			pr_debug("Problems creating module maps, "
974 				 "continuing anyway...\n");
975 		else
976 			pr_debug("Problems creating module maps for guest %d, "
977 				 "continuing anyway...\n", machine->pid);
978 	}
979 
980 	/*
981 	 * Now that we have all the maps created, just set the ->end of them:
982 	 */
983 	map_groups__fixup_end(&machine->kmaps);
984 
985 	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
986 					     addr)) {
987 		machine__destroy_kernel_maps(machine);
988 		return -1;
989 	}
990 
991 	return 0;
992 }
993 
994 static void machine__set_kernel_mmap_len(struct machine *machine,
995 					 union perf_event *event)
996 {
997 	int i;
998 
999 	for (i = 0; i < MAP__NR_TYPES; i++) {
1000 		machine->vmlinux_maps[i]->start = event->mmap.start;
1001 		machine->vmlinux_maps[i]->end   = (event->mmap.start +
1002 						   event->mmap.len);
1003 		/*
1004 		 * Be a bit paranoid here, some perf.data file came with
1005 		 * a zero sized synthesized MMAP event for the kernel.
1006 		 */
1007 		if (machine->vmlinux_maps[i]->end == 0)
1008 			machine->vmlinux_maps[i]->end = ~0ULL;
1009 	}
1010 }
1011 
1012 static bool machine__uses_kcore(struct machine *machine)
1013 {
1014 	struct dso *dso;
1015 
1016 	list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1017 		if (dso__is_kcore(dso))
1018 			return true;
1019 	}
1020 
1021 	return false;
1022 }
1023 
1024 static int machine__process_kernel_mmap_event(struct machine *machine,
1025 					      union perf_event *event)
1026 {
1027 	struct map *map;
1028 	char kmmap_prefix[PATH_MAX];
1029 	enum dso_kernel_type kernel_type;
1030 	bool is_kernel_mmap;
1031 
1032 	/* If we have maps from kcore then we do not need or want any others */
1033 	if (machine__uses_kcore(machine))
1034 		return 0;
1035 
1036 	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
1037 	if (machine__is_host(machine))
1038 		kernel_type = DSO_TYPE_KERNEL;
1039 	else
1040 		kernel_type = DSO_TYPE_GUEST_KERNEL;
1041 
1042 	is_kernel_mmap = memcmp(event->mmap.filename,
1043 				kmmap_prefix,
1044 				strlen(kmmap_prefix) - 1) == 0;
1045 	if (event->mmap.filename[0] == '/' ||
1046 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
1047 
1048 		char short_module_name[1024];
1049 		char *name, *dot;
1050 
1051 		if (event->mmap.filename[0] == '/') {
1052 			name = strrchr(event->mmap.filename, '/');
1053 			if (name == NULL)
1054 				goto out_problem;
1055 
1056 			++name; /* skip / */
1057 			dot = strrchr(name, '.');
1058 			if (dot == NULL)
1059 				goto out_problem;
1060 			/* On some system, modules are compressed like .ko.gz */
1061 			if (is_supported_compression(dot + 1))
1062 				dot -= 3;
1063 			if (!is_kmodule_extension(dot + 1))
1064 				goto out_problem;
1065 			snprintf(short_module_name, sizeof(short_module_name),
1066 					"[%.*s]", (int)(dot - name), name);
1067 			strxfrchar(short_module_name, '-', '_');
1068 		} else
1069 			strcpy(short_module_name, event->mmap.filename);
1070 
1071 		map = machine__new_module(machine, event->mmap.start,
1072 					  event->mmap.filename);
1073 		if (map == NULL)
1074 			goto out_problem;
1075 
1076 		name = strdup(short_module_name);
1077 		if (name == NULL)
1078 			goto out_problem;
1079 
1080 		dso__set_short_name(map->dso, name, true);
1081 		map->end = map->start + event->mmap.len;
1082 	} else if (is_kernel_mmap) {
1083 		const char *symbol_name = (event->mmap.filename +
1084 				strlen(kmmap_prefix));
1085 		/*
1086 		 * Should be there already, from the build-id table in
1087 		 * the header.
1088 		 */
1089 		struct dso *kernel = NULL;
1090 		struct dso *dso;
1091 
1092 		list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
1093 			if (is_kernel_module(dso->long_name, NULL))
1094 				continue;
1095 
1096 			kernel = dso;
1097 			break;
1098 		}
1099 
1100 		if (kernel == NULL)
1101 			kernel = __dsos__findnew(&machine->kernel_dsos,
1102 						 kmmap_prefix);
1103 		if (kernel == NULL)
1104 			goto out_problem;
1105 
1106 		kernel->kernel = kernel_type;
1107 		if (__machine__create_kernel_maps(machine, kernel) < 0)
1108 			goto out_problem;
1109 
1110 		if (strstr(kernel->long_name, "vmlinux"))
1111 			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
1112 
1113 		machine__set_kernel_mmap_len(machine, event);
1114 
1115 		/*
1116 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
1117 		 * symbol. Effectively having zero here means that at record
1118 		 * time /proc/sys/kernel/kptr_restrict was non zero.
1119 		 */
1120 		if (event->mmap.pgoff != 0) {
1121 			maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
1122 							 symbol_name,
1123 							 event->mmap.pgoff);
1124 		}
1125 
1126 		if (machine__is_default_guest(machine)) {
1127 			/*
1128 			 * preload dso of guest kernel and modules
1129 			 */
1130 			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
1131 				  NULL);
1132 		}
1133 	}
1134 	return 0;
1135 out_problem:
1136 	return -1;
1137 }
1138 
1139 int machine__process_mmap2_event(struct machine *machine,
1140 				 union perf_event *event,
1141 				 struct perf_sample *sample __maybe_unused)
1142 {
1143 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1144 	struct thread *thread;
1145 	struct map *map;
1146 	enum map_type type;
1147 	int ret = 0;
1148 
1149 	if (dump_trace)
1150 		perf_event__fprintf_mmap2(event, stdout);
1151 
1152 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1153 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1154 		ret = machine__process_kernel_mmap_event(machine, event);
1155 		if (ret < 0)
1156 			goto out_problem;
1157 		return 0;
1158 	}
1159 
1160 	thread = machine__findnew_thread(machine, event->mmap2.pid,
1161 					event->mmap2.tid);
1162 	if (thread == NULL)
1163 		goto out_problem;
1164 
1165 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1166 		type = MAP__VARIABLE;
1167 	else
1168 		type = MAP__FUNCTION;
1169 
1170 	map = map__new(machine, event->mmap2.start,
1171 			event->mmap2.len, event->mmap2.pgoff,
1172 			event->mmap2.pid, event->mmap2.maj,
1173 			event->mmap2.min, event->mmap2.ino,
1174 			event->mmap2.ino_generation,
1175 			event->mmap2.prot,
1176 			event->mmap2.flags,
1177 			event->mmap2.filename, type, thread);
1178 
1179 	if (map == NULL)
1180 		goto out_problem;
1181 
1182 	thread__insert_map(thread, map);
1183 	return 0;
1184 
1185 out_problem:
1186 	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
1187 	return 0;
1188 }
1189 
1190 int machine__process_mmap_event(struct machine *machine, union perf_event *event,
1191 				struct perf_sample *sample __maybe_unused)
1192 {
1193 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1194 	struct thread *thread;
1195 	struct map *map;
1196 	enum map_type type;
1197 	int ret = 0;
1198 
1199 	if (dump_trace)
1200 		perf_event__fprintf_mmap(event, stdout);
1201 
1202 	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1203 	    cpumode == PERF_RECORD_MISC_KERNEL) {
1204 		ret = machine__process_kernel_mmap_event(machine, event);
1205 		if (ret < 0)
1206 			goto out_problem;
1207 		return 0;
1208 	}
1209 
1210 	thread = machine__findnew_thread(machine, event->mmap.pid,
1211 					 event->mmap.tid);
1212 	if (thread == NULL)
1213 		goto out_problem;
1214 
1215 	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
1216 		type = MAP__VARIABLE;
1217 	else
1218 		type = MAP__FUNCTION;
1219 
1220 	map = map__new(machine, event->mmap.start,
1221 			event->mmap.len, event->mmap.pgoff,
1222 			event->mmap.pid, 0, 0, 0, 0, 0, 0,
1223 			event->mmap.filename,
1224 			type, thread);
1225 
1226 	if (map == NULL)
1227 		goto out_problem;
1228 
1229 	thread__insert_map(thread, map);
1230 	return 0;
1231 
1232 out_problem:
1233 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
1234 	return 0;
1235 }
1236 
1237 static void machine__remove_thread(struct machine *machine, struct thread *th)
1238 {
1239 	machine->last_match = NULL;
1240 	rb_erase(&th->rb_node, &machine->threads);
1241 	/*
1242 	 * We may have references to this thread, for instance in some hist_entry
1243 	 * instances, so just move them to a separate list.
1244 	 */
1245 	list_add_tail(&th->node, &machine->dead_threads);
1246 }
1247 
1248 int machine__process_fork_event(struct machine *machine, union perf_event *event,
1249 				struct perf_sample *sample)
1250 {
1251 	struct thread *thread = machine__find_thread(machine,
1252 						     event->fork.pid,
1253 						     event->fork.tid);
1254 	struct thread *parent = machine__findnew_thread(machine,
1255 							event->fork.ppid,
1256 							event->fork.ptid);
1257 
1258 	/* if a thread currently exists for the thread id remove it */
1259 	if (thread != NULL)
1260 		machine__remove_thread(machine, thread);
1261 
1262 	thread = machine__findnew_thread(machine, event->fork.pid,
1263 					 event->fork.tid);
1264 	if (dump_trace)
1265 		perf_event__fprintf_task(event, stdout);
1266 
1267 	if (thread == NULL || parent == NULL ||
1268 	    thread__fork(thread, parent, sample->time) < 0) {
1269 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
1270 		return -1;
1271 	}
1272 
1273 	return 0;
1274 }
1275 
1276 int machine__process_exit_event(struct machine *machine, union perf_event *event,
1277 				struct perf_sample *sample __maybe_unused)
1278 {
1279 	struct thread *thread = machine__find_thread(machine,
1280 						     event->fork.pid,
1281 						     event->fork.tid);
1282 
1283 	if (dump_trace)
1284 		perf_event__fprintf_task(event, stdout);
1285 
1286 	if (thread != NULL)
1287 		thread__exited(thread);
1288 
1289 	return 0;
1290 }
1291 
1292 int machine__process_event(struct machine *machine, union perf_event *event,
1293 			   struct perf_sample *sample)
1294 {
1295 	int ret;
1296 
1297 	switch (event->header.type) {
1298 	case PERF_RECORD_COMM:
1299 		ret = machine__process_comm_event(machine, event, sample); break;
1300 	case PERF_RECORD_MMAP:
1301 		ret = machine__process_mmap_event(machine, event, sample); break;
1302 	case PERF_RECORD_MMAP2:
1303 		ret = machine__process_mmap2_event(machine, event, sample); break;
1304 	case PERF_RECORD_FORK:
1305 		ret = machine__process_fork_event(machine, event, sample); break;
1306 	case PERF_RECORD_EXIT:
1307 		ret = machine__process_exit_event(machine, event, sample); break;
1308 	case PERF_RECORD_LOST:
1309 		ret = machine__process_lost_event(machine, event, sample); break;
1310 	default:
1311 		ret = -1;
1312 		break;
1313 	}
1314 
1315 	return ret;
1316 }
1317 
1318 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
1319 {
1320 	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
1321 		return 1;
1322 	return 0;
1323 }
1324 
1325 static void ip__resolve_ams(struct thread *thread,
1326 			    struct addr_map_symbol *ams,
1327 			    u64 ip)
1328 {
1329 	struct addr_location al;
1330 
1331 	memset(&al, 0, sizeof(al));
1332 	/*
1333 	 * We cannot use the header.misc hint to determine whether a
1334 	 * branch stack address is user, kernel, guest, hypervisor.
1335 	 * Branches may straddle the kernel/user/hypervisor boundaries.
1336 	 * Thus, we have to try consecutively until we find a match
1337 	 * or else, the symbol is unknown
1338 	 */
1339 	thread__find_cpumode_addr_location(thread, MAP__FUNCTION, ip, &al);
1340 
1341 	ams->addr = ip;
1342 	ams->al_addr = al.addr;
1343 	ams->sym = al.sym;
1344 	ams->map = al.map;
1345 }
1346 
1347 static void ip__resolve_data(struct thread *thread,
1348 			     u8 m, struct addr_map_symbol *ams, u64 addr)
1349 {
1350 	struct addr_location al;
1351 
1352 	memset(&al, 0, sizeof(al));
1353 
1354 	thread__find_addr_location(thread, m, MAP__VARIABLE, addr, &al);
1355 	if (al.map == NULL) {
1356 		/*
1357 		 * some shared data regions have execute bit set which puts
1358 		 * their mapping in the MAP__FUNCTION type array.
1359 		 * Check there as a fallback option before dropping the sample.
1360 		 */
1361 		thread__find_addr_location(thread, m, MAP__FUNCTION, addr, &al);
1362 	}
1363 
1364 	ams->addr = addr;
1365 	ams->al_addr = al.addr;
1366 	ams->sym = al.sym;
1367 	ams->map = al.map;
1368 }
1369 
1370 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
1371 				     struct addr_location *al)
1372 {
1373 	struct mem_info *mi = zalloc(sizeof(*mi));
1374 
1375 	if (!mi)
1376 		return NULL;
1377 
1378 	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
1379 	ip__resolve_data(al->thread, al->cpumode, &mi->daddr, sample->addr);
1380 	mi->data_src.val = sample->data_src;
1381 
1382 	return mi;
1383 }
1384 
1385 static int add_callchain_ip(struct thread *thread,
1386 			    struct symbol **parent,
1387 			    struct addr_location *root_al,
1388 			    bool branch_history,
1389 			    u64 ip)
1390 {
1391 	struct addr_location al;
1392 
1393 	al.filtered = 0;
1394 	al.sym = NULL;
1395 	if (branch_history)
1396 		thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
1397 						   ip, &al);
1398 	else {
1399 		u8 cpumode = PERF_RECORD_MISC_USER;
1400 
1401 		if (ip >= PERF_CONTEXT_MAX) {
1402 			switch (ip) {
1403 			case PERF_CONTEXT_HV:
1404 				cpumode = PERF_RECORD_MISC_HYPERVISOR;
1405 				break;
1406 			case PERF_CONTEXT_KERNEL:
1407 				cpumode = PERF_RECORD_MISC_KERNEL;
1408 				break;
1409 			case PERF_CONTEXT_USER:
1410 				cpumode = PERF_RECORD_MISC_USER;
1411 				break;
1412 			default:
1413 				pr_debug("invalid callchain context: "
1414 					 "%"PRId64"\n", (s64) ip);
1415 				/*
1416 				 * It seems the callchain is corrupted.
1417 				 * Discard all.
1418 				 */
1419 				callchain_cursor_reset(&callchain_cursor);
1420 				return 1;
1421 			}
1422 			return 0;
1423 		}
1424 		thread__find_addr_location(thread, cpumode, MAP__FUNCTION,
1425 				   ip, &al);
1426 	}
1427 
1428 	if (al.sym != NULL) {
1429 		if (sort__has_parent && !*parent &&
1430 		    symbol__match_regex(al.sym, &parent_regex))
1431 			*parent = al.sym;
1432 		else if (have_ignore_callees && root_al &&
1433 		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
1434 			/* Treat this symbol as the root,
1435 			   forgetting its callees. */
1436 			*root_al = al;
1437 			callchain_cursor_reset(&callchain_cursor);
1438 		}
1439 	}
1440 
1441 	return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);
1442 }
1443 
1444 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
1445 					   struct addr_location *al)
1446 {
1447 	unsigned int i;
1448 	const struct branch_stack *bs = sample->branch_stack;
1449 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
1450 
1451 	if (!bi)
1452 		return NULL;
1453 
1454 	for (i = 0; i < bs->nr; i++) {
1455 		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
1456 		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
1457 		bi[i].flags = bs->entries[i].flags;
1458 	}
1459 	return bi;
1460 }
1461 
1462 #define CHASHSZ 127
1463 #define CHASHBITS 7
1464 #define NO_ENTRY 0xff
1465 
1466 #define PERF_MAX_BRANCH_DEPTH 127
1467 
1468 /* Remove loops. */
1469 static int remove_loops(struct branch_entry *l, int nr)
1470 {
1471 	int i, j, off;
1472 	unsigned char chash[CHASHSZ];
1473 
1474 	memset(chash, NO_ENTRY, sizeof(chash));
1475 
1476 	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
1477 
1478 	for (i = 0; i < nr; i++) {
1479 		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
1480 
1481 		/* no collision handling for now */
1482 		if (chash[h] == NO_ENTRY) {
1483 			chash[h] = i;
1484 		} else if (l[chash[h]].from == l[i].from) {
1485 			bool is_loop = true;
1486 			/* check if it is a real loop */
1487 			off = 0;
1488 			for (j = chash[h]; j < i && i + off < nr; j++, off++)
1489 				if (l[j].from != l[i + off].from) {
1490 					is_loop = false;
1491 					break;
1492 				}
1493 			if (is_loop) {
1494 				memmove(l + i, l + i + off,
1495 					(nr - (i + off)) * sizeof(*l));
1496 				nr -= off;
1497 			}
1498 		}
1499 	}
1500 	return nr;
1501 }
1502 
1503 static int thread__resolve_callchain_sample(struct thread *thread,
1504 					     struct ip_callchain *chain,
1505 					     struct branch_stack *branch,
1506 					     struct symbol **parent,
1507 					     struct addr_location *root_al,
1508 					     int max_stack)
1509 {
1510 	int chain_nr = min(max_stack, (int)chain->nr);
1511 	int i, j, err;
1512 	int skip_idx = -1;
1513 	int first_call = 0;
1514 
1515 	/*
1516 	 * Based on DWARF debug information, some architectures skip
1517 	 * a callchain entry saved by the kernel.
1518 	 */
1519 	if (chain->nr < PERF_MAX_STACK_DEPTH)
1520 		skip_idx = arch_skip_callchain_idx(thread, chain);
1521 
1522 	callchain_cursor_reset(&callchain_cursor);
1523 
1524 	/*
1525 	 * Add branches to call stack for easier browsing. This gives
1526 	 * more context for a sample than just the callers.
1527 	 *
1528 	 * This uses individual histograms of paths compared to the
1529 	 * aggregated histograms the normal LBR mode uses.
1530 	 *
1531 	 * Limitations for now:
1532 	 * - No extra filters
1533 	 * - No annotations (should annotate somehow)
1534 	 */
1535 
1536 	if (branch && callchain_param.branch_callstack) {
1537 		int nr = min(max_stack, (int)branch->nr);
1538 		struct branch_entry be[nr];
1539 
1540 		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
1541 			pr_warning("corrupted branch chain. skipping...\n");
1542 			goto check_calls;
1543 		}
1544 
1545 		for (i = 0; i < nr; i++) {
1546 			if (callchain_param.order == ORDER_CALLEE) {
1547 				be[i] = branch->entries[i];
1548 				/*
1549 				 * Check for overlap into the callchain.
1550 				 * The return address is one off compared to
1551 				 * the branch entry. To adjust for this
1552 				 * assume the calling instruction is not longer
1553 				 * than 8 bytes.
1554 				 */
1555 				if (i == skip_idx ||
1556 				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
1557 					first_call++;
1558 				else if (be[i].from < chain->ips[first_call] &&
1559 				    be[i].from >= chain->ips[first_call] - 8)
1560 					first_call++;
1561 			} else
1562 				be[i] = branch->entries[branch->nr - i - 1];
1563 		}
1564 
1565 		nr = remove_loops(be, nr);
1566 
1567 		for (i = 0; i < nr; i++) {
1568 			err = add_callchain_ip(thread, parent, root_al,
1569 					       true, be[i].to);
1570 			if (!err)
1571 				err = add_callchain_ip(thread, parent, root_al,
1572 						       true, be[i].from);
1573 			if (err == -EINVAL)
1574 				break;
1575 			if (err)
1576 				return err;
1577 		}
1578 		chain_nr -= nr;
1579 	}
1580 
1581 check_calls:
1582 	if (chain->nr > PERF_MAX_STACK_DEPTH) {
1583 		pr_warning("corrupted callchain. skipping...\n");
1584 		return 0;
1585 	}
1586 
1587 	for (i = first_call; i < chain_nr; i++) {
1588 		u64 ip;
1589 
1590 		if (callchain_param.order == ORDER_CALLEE)
1591 			j = i;
1592 		else
1593 			j = chain->nr - i - 1;
1594 
1595 #ifdef HAVE_SKIP_CALLCHAIN_IDX
1596 		if (j == skip_idx)
1597 			continue;
1598 #endif
1599 		ip = chain->ips[j];
1600 
1601 		err = add_callchain_ip(thread, parent, root_al, false, ip);
1602 
1603 		if (err)
1604 			return (err < 0) ? err : 0;
1605 	}
1606 
1607 	return 0;
1608 }
1609 
1610 static int unwind_entry(struct unwind_entry *entry, void *arg)
1611 {
1612 	struct callchain_cursor *cursor = arg;
1613 	return callchain_cursor_append(cursor, entry->ip,
1614 				       entry->map, entry->sym);
1615 }
1616 
1617 int thread__resolve_callchain(struct thread *thread,
1618 			      struct perf_evsel *evsel,
1619 			      struct perf_sample *sample,
1620 			      struct symbol **parent,
1621 			      struct addr_location *root_al,
1622 			      int max_stack)
1623 {
1624 	int ret = thread__resolve_callchain_sample(thread, sample->callchain,
1625 						   sample->branch_stack,
1626 						   parent, root_al, max_stack);
1627 	if (ret)
1628 		return ret;
1629 
1630 	/* Can we do dwarf post unwind? */
1631 	if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
1632 	      (evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
1633 		return 0;
1634 
1635 	/* Bail out if nothing was captured. */
1636 	if ((!sample->user_regs.regs) ||
1637 	    (!sample->user_stack.size))
1638 		return 0;
1639 
1640 	return unwind__get_entries(unwind_entry, &callchain_cursor,
1641 				   thread, sample, max_stack);
1642 
1643 }
1644 
1645 int machine__for_each_thread(struct machine *machine,
1646 			     int (*fn)(struct thread *thread, void *p),
1647 			     void *priv)
1648 {
1649 	struct rb_node *nd;
1650 	struct thread *thread;
1651 	int rc = 0;
1652 
1653 	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
1654 		thread = rb_entry(nd, struct thread, rb_node);
1655 		rc = fn(thread, priv);
1656 		if (rc != 0)
1657 			return rc;
1658 	}
1659 
1660 	list_for_each_entry(thread, &machine->dead_threads, node) {
1661 		rc = fn(thread, priv);
1662 		if (rc != 0)
1663 			return rc;
1664 	}
1665 	return rc;
1666 }
1667 
1668 int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
1669 				  struct target *target, struct thread_map *threads,
1670 				  perf_event__handler_t process, bool data_mmap)
1671 {
1672 	if (target__has_task(target))
1673 		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
1674 	else if (target__has_cpu(target))
1675 		return perf_event__synthesize_threads(tool, process, machine, data_mmap);
1676 	/* command specified */
1677 	return 0;
1678 }
1679 
1680 pid_t machine__get_current_tid(struct machine *machine, int cpu)
1681 {
1682 	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
1683 		return -1;
1684 
1685 	return machine->current_tid[cpu];
1686 }
1687 
1688 int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
1689 			     pid_t tid)
1690 {
1691 	struct thread *thread;
1692 
1693 	if (cpu < 0)
1694 		return -EINVAL;
1695 
1696 	if (!machine->current_tid) {
1697 		int i;
1698 
1699 		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
1700 		if (!machine->current_tid)
1701 			return -ENOMEM;
1702 		for (i = 0; i < MAX_NR_CPUS; i++)
1703 			machine->current_tid[i] = -1;
1704 	}
1705 
1706 	if (cpu >= MAX_NR_CPUS) {
1707 		pr_err("Requested CPU %d too large. ", cpu);
1708 		pr_err("Consider raising MAX_NR_CPUS\n");
1709 		return -EINVAL;
1710 	}
1711 
1712 	machine->current_tid[cpu] = tid;
1713 
1714 	thread = machine__findnew_thread(machine, pid, tid);
1715 	if (!thread)
1716 		return -ENOMEM;
1717 
1718 	thread->cpu = cpu;
1719 
1720 	return 0;
1721 }
1722 
1723 int machine__get_kernel_start(struct machine *machine)
1724 {
1725 	struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
1726 	int err = 0;
1727 
1728 	/*
1729 	 * The only addresses above 2^63 are kernel addresses of a 64-bit
1730 	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
1731 	 * all addresses including kernel addresses are less than 2^32.  In
1732 	 * that case (32-bit system), if the kernel mapping is unknown, all
1733 	 * addresses will be assumed to be in user space - see
1734 	 * machine__kernel_ip().
1735 	 */
1736 	machine->kernel_start = 1ULL << 63;
1737 	if (map) {
1738 		err = map__load(map, machine->symbol_filter);
1739 		if (map->start)
1740 			machine->kernel_start = map->start;
1741 	}
1742 	return err;
1743 }
1744