xref: /linux/tools/perf/util/machine.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <dirent.h>
3 #include <errno.h>
4 #include <inttypes.h>
5 #include <regex.h>
6 #include <stdlib.h>
7 #include "callchain.h"
8 #include "debug.h"
9 #include "dso.h"
10 #include "env.h"
11 #include "event.h"
12 #include "evsel.h"
13 #include "hist.h"
14 #include "machine.h"
15 #include "map.h"
16 #include "map_symbol.h"
17 #include "branch.h"
18 #include "mem-events.h"
19 #include "path.h"
20 #include "srcline.h"
21 #include "symbol.h"
22 #include "sort.h"
23 #include "strlist.h"
24 #include "target.h"
25 #include "thread.h"
26 #include "util.h"
27 #include "vdso.h"
28 #include <stdbool.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <unistd.h>
32 #include "unwind.h"
33 #include "linux/hash.h"
34 #include "asm/bug.h"
35 #include "bpf-event.h"
36 #include <internal/lib.h> // page_size
37 #include "cgroup.h"
38 #include "arm64-frame-pointer-unwind-support.h"
39 
40 #include <linux/ctype.h>
41 #include <symbol/kallsyms.h>
42 #include <linux/mman.h>
43 #include <linux/string.h>
44 #include <linux/zalloc.h>
45 
46 static void __machine__remove_thread(struct machine *machine, struct thread_rb_node *nd,
47 				     struct thread *th, bool lock);
48 
49 static struct dso *machine__kernel_dso(struct machine *machine)
50 {
51 	return map__dso(machine->vmlinux_map);
52 }
53 
54 static void dsos__init(struct dsos *dsos)
55 {
56 	INIT_LIST_HEAD(&dsos->head);
57 	dsos->root = RB_ROOT;
58 	init_rwsem(&dsos->lock);
59 }
60 
61 static void machine__threads_init(struct machine *machine)
62 {
63 	int i;
64 
65 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
66 		struct threads *threads = &machine->threads[i];
67 		threads->entries = RB_ROOT_CACHED;
68 		init_rwsem(&threads->lock);
69 		threads->nr = 0;
70 		threads->last_match = NULL;
71 	}
72 }
73 
74 static int thread_rb_node__cmp_tid(const void *key, const struct rb_node *nd)
75 {
76 	int to_find = (int) *((pid_t *)key);
77 
78 	return to_find - (int)thread__tid(rb_entry(nd, struct thread_rb_node, rb_node)->thread);
79 }
80 
81 static struct thread_rb_node *thread_rb_node__find(const struct thread *th,
82 						   struct rb_root *tree)
83 {
84 	pid_t to_find = thread__tid(th);
85 	struct rb_node *nd = rb_find(&to_find, tree, thread_rb_node__cmp_tid);
86 
87 	return rb_entry(nd, struct thread_rb_node, rb_node);
88 }
89 
90 static int machine__set_mmap_name(struct machine *machine)
91 {
92 	if (machine__is_host(machine))
93 		machine->mmap_name = strdup("[kernel.kallsyms]");
94 	else if (machine__is_default_guest(machine))
95 		machine->mmap_name = strdup("[guest.kernel.kallsyms]");
96 	else if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]",
97 			  machine->pid) < 0)
98 		machine->mmap_name = NULL;
99 
100 	return machine->mmap_name ? 0 : -ENOMEM;
101 }
102 
103 static void thread__set_guest_comm(struct thread *thread, pid_t pid)
104 {
105 	char comm[64];
106 
107 	snprintf(comm, sizeof(comm), "[guest/%d]", pid);
108 	thread__set_comm(thread, comm, 0);
109 }
110 
111 int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
112 {
113 	int err = -ENOMEM;
114 
115 	memset(machine, 0, sizeof(*machine));
116 	machine->kmaps = maps__new(machine);
117 	if (machine->kmaps == NULL)
118 		return -ENOMEM;
119 
120 	RB_CLEAR_NODE(&machine->rb_node);
121 	dsos__init(&machine->dsos);
122 
123 	machine__threads_init(machine);
124 
125 	machine->vdso_info = NULL;
126 	machine->env = NULL;
127 
128 	machine->pid = pid;
129 
130 	machine->id_hdr_size = 0;
131 	machine->kptr_restrict_warned = false;
132 	machine->comm_exec = false;
133 	machine->kernel_start = 0;
134 	machine->vmlinux_map = NULL;
135 
136 	machine->root_dir = strdup(root_dir);
137 	if (machine->root_dir == NULL)
138 		goto out;
139 
140 	if (machine__set_mmap_name(machine))
141 		goto out;
142 
143 	if (pid != HOST_KERNEL_ID) {
144 		struct thread *thread = machine__findnew_thread(machine, -1,
145 								pid);
146 
147 		if (thread == NULL)
148 			goto out;
149 
150 		thread__set_guest_comm(thread, pid);
151 		thread__put(thread);
152 	}
153 
154 	machine->current_tid = NULL;
155 	err = 0;
156 
157 out:
158 	if (err) {
159 		zfree(&machine->kmaps);
160 		zfree(&machine->root_dir);
161 		zfree(&machine->mmap_name);
162 	}
163 	return 0;
164 }
165 
166 struct machine *machine__new_host(void)
167 {
168 	struct machine *machine = malloc(sizeof(*machine));
169 
170 	if (machine != NULL) {
171 		machine__init(machine, "", HOST_KERNEL_ID);
172 
173 		if (machine__create_kernel_maps(machine) < 0)
174 			goto out_delete;
175 	}
176 
177 	return machine;
178 out_delete:
179 	free(machine);
180 	return NULL;
181 }
182 
183 struct machine *machine__new_kallsyms(void)
184 {
185 	struct machine *machine = machine__new_host();
186 	/*
187 	 * FIXME:
188 	 * 1) We should switch to machine__load_kallsyms(), i.e. not explicitly
189 	 *    ask for not using the kcore parsing code, once this one is fixed
190 	 *    to create a map per module.
191 	 */
192 	if (machine && machine__load_kallsyms(machine, "/proc/kallsyms") <= 0) {
193 		machine__delete(machine);
194 		machine = NULL;
195 	}
196 
197 	return machine;
198 }
199 
200 static void dsos__purge(struct dsos *dsos)
201 {
202 	struct dso *pos, *n;
203 
204 	down_write(&dsos->lock);
205 
206 	list_for_each_entry_safe(pos, n, &dsos->head, node) {
207 		RB_CLEAR_NODE(&pos->rb_node);
208 		pos->root = NULL;
209 		list_del_init(&pos->node);
210 		dso__put(pos);
211 	}
212 
213 	up_write(&dsos->lock);
214 }
215 
216 static void dsos__exit(struct dsos *dsos)
217 {
218 	dsos__purge(dsos);
219 	exit_rwsem(&dsos->lock);
220 }
221 
222 void machine__delete_threads(struct machine *machine)
223 {
224 	struct rb_node *nd;
225 	int i;
226 
227 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
228 		struct threads *threads = &machine->threads[i];
229 		down_write(&threads->lock);
230 		nd = rb_first_cached(&threads->entries);
231 		while (nd) {
232 			struct thread_rb_node *trb = rb_entry(nd, struct thread_rb_node, rb_node);
233 
234 			nd = rb_next(nd);
235 			__machine__remove_thread(machine, trb, trb->thread, false);
236 		}
237 		up_write(&threads->lock);
238 	}
239 }
240 
241 void machine__exit(struct machine *machine)
242 {
243 	int i;
244 
245 	if (machine == NULL)
246 		return;
247 
248 	machine__destroy_kernel_maps(machine);
249 	maps__zput(machine->kmaps);
250 	dsos__exit(&machine->dsos);
251 	machine__exit_vdso(machine);
252 	zfree(&machine->root_dir);
253 	zfree(&machine->mmap_name);
254 	zfree(&machine->current_tid);
255 	zfree(&machine->kallsyms_filename);
256 
257 	machine__delete_threads(machine);
258 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
259 		struct threads *threads = &machine->threads[i];
260 
261 		exit_rwsem(&threads->lock);
262 	}
263 }
264 
265 void machine__delete(struct machine *machine)
266 {
267 	if (machine) {
268 		machine__exit(machine);
269 		free(machine);
270 	}
271 }
272 
273 void machines__init(struct machines *machines)
274 {
275 	machine__init(&machines->host, "", HOST_KERNEL_ID);
276 	machines->guests = RB_ROOT_CACHED;
277 }
278 
279 void machines__exit(struct machines *machines)
280 {
281 	machine__exit(&machines->host);
282 	/* XXX exit guest */
283 }
284 
285 struct machine *machines__add(struct machines *machines, pid_t pid,
286 			      const char *root_dir)
287 {
288 	struct rb_node **p = &machines->guests.rb_root.rb_node;
289 	struct rb_node *parent = NULL;
290 	struct machine *pos, *machine = malloc(sizeof(*machine));
291 	bool leftmost = true;
292 
293 	if (machine == NULL)
294 		return NULL;
295 
296 	if (machine__init(machine, root_dir, pid) != 0) {
297 		free(machine);
298 		return NULL;
299 	}
300 
301 	while (*p != NULL) {
302 		parent = *p;
303 		pos = rb_entry(parent, struct machine, rb_node);
304 		if (pid < pos->pid)
305 			p = &(*p)->rb_left;
306 		else {
307 			p = &(*p)->rb_right;
308 			leftmost = false;
309 		}
310 	}
311 
312 	rb_link_node(&machine->rb_node, parent, p);
313 	rb_insert_color_cached(&machine->rb_node, &machines->guests, leftmost);
314 
315 	machine->machines = machines;
316 
317 	return machine;
318 }
319 
320 void machines__set_comm_exec(struct machines *machines, bool comm_exec)
321 {
322 	struct rb_node *nd;
323 
324 	machines->host.comm_exec = comm_exec;
325 
326 	for (nd = rb_first_cached(&machines->guests); nd; nd = rb_next(nd)) {
327 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
328 
329 		machine->comm_exec = comm_exec;
330 	}
331 }
332 
333 struct machine *machines__find(struct machines *machines, pid_t pid)
334 {
335 	struct rb_node **p = &machines->guests.rb_root.rb_node;
336 	struct rb_node *parent = NULL;
337 	struct machine *machine;
338 	struct machine *default_machine = NULL;
339 
340 	if (pid == HOST_KERNEL_ID)
341 		return &machines->host;
342 
343 	while (*p != NULL) {
344 		parent = *p;
345 		machine = rb_entry(parent, struct machine, rb_node);
346 		if (pid < machine->pid)
347 			p = &(*p)->rb_left;
348 		else if (pid > machine->pid)
349 			p = &(*p)->rb_right;
350 		else
351 			return machine;
352 		if (!machine->pid)
353 			default_machine = machine;
354 	}
355 
356 	return default_machine;
357 }
358 
359 struct machine *machines__findnew(struct machines *machines, pid_t pid)
360 {
361 	char path[PATH_MAX];
362 	const char *root_dir = "";
363 	struct machine *machine = machines__find(machines, pid);
364 
365 	if (machine && (machine->pid == pid))
366 		goto out;
367 
368 	if ((pid != HOST_KERNEL_ID) &&
369 	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
370 	    (symbol_conf.guestmount)) {
371 		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
372 		if (access(path, R_OK)) {
373 			static struct strlist *seen;
374 
375 			if (!seen)
376 				seen = strlist__new(NULL, NULL);
377 
378 			if (!strlist__has_entry(seen, path)) {
379 				pr_err("Can't access file %s\n", path);
380 				strlist__add(seen, path);
381 			}
382 			machine = NULL;
383 			goto out;
384 		}
385 		root_dir = path;
386 	}
387 
388 	machine = machines__add(machines, pid, root_dir);
389 out:
390 	return machine;
391 }
392 
393 struct machine *machines__find_guest(struct machines *machines, pid_t pid)
394 {
395 	struct machine *machine = machines__find(machines, pid);
396 
397 	if (!machine)
398 		machine = machines__findnew(machines, DEFAULT_GUEST_KERNEL_ID);
399 	return machine;
400 }
401 
402 /*
403  * A common case for KVM test programs is that the test program acts as the
404  * hypervisor, creating, running and destroying the virtual machine, and
405  * providing the guest object code from its own object code. In this case,
406  * the VM is not running an OS, but only the functions loaded into it by the
407  * hypervisor test program, and conveniently, loaded at the same virtual
408  * addresses.
409  *
410  * Normally to resolve addresses, MMAP events are needed to map addresses
411  * back to the object code and debug symbols for that object code.
412  *
413  * Currently, there is no way to get such mapping information from guests
414  * but, in the scenario described above, the guest has the same mappings
415  * as the hypervisor, so support for that scenario can be achieved.
416  *
417  * To support that, copy the host thread's maps to the guest thread's maps.
418  * Note, we do not discover the guest until we encounter a guest event,
419  * which works well because it is not until then that we know that the host
420  * thread's maps have been set up.
421  *
422  * This function returns the guest thread. Apart from keeping the data
423  * structures sane, using a thread belonging to the guest machine, instead
424  * of the host thread, allows it to have its own comm (refer
425  * thread__set_guest_comm()).
426  */
427 static struct thread *findnew_guest_code(struct machine *machine,
428 					 struct machine *host_machine,
429 					 pid_t pid)
430 {
431 	struct thread *host_thread;
432 	struct thread *thread;
433 	int err;
434 
435 	if (!machine)
436 		return NULL;
437 
438 	thread = machine__findnew_thread(machine, -1, pid);
439 	if (!thread)
440 		return NULL;
441 
442 	/* Assume maps are set up if there are any */
443 	if (maps__nr_maps(thread__maps(thread)))
444 		return thread;
445 
446 	host_thread = machine__find_thread(host_machine, -1, pid);
447 	if (!host_thread)
448 		goto out_err;
449 
450 	thread__set_guest_comm(thread, pid);
451 
452 	/*
453 	 * Guest code can be found in hypervisor process at the same address
454 	 * so copy host maps.
455 	 */
456 	err = maps__clone(thread, thread__maps(host_thread));
457 	thread__put(host_thread);
458 	if (err)
459 		goto out_err;
460 
461 	return thread;
462 
463 out_err:
464 	thread__zput(thread);
465 	return NULL;
466 }
467 
468 struct thread *machines__findnew_guest_code(struct machines *machines, pid_t pid)
469 {
470 	struct machine *host_machine = machines__find(machines, HOST_KERNEL_ID);
471 	struct machine *machine = machines__findnew(machines, pid);
472 
473 	return findnew_guest_code(machine, host_machine, pid);
474 }
475 
476 struct thread *machine__findnew_guest_code(struct machine *machine, pid_t pid)
477 {
478 	struct machines *machines = machine->machines;
479 	struct machine *host_machine;
480 
481 	if (!machines)
482 		return NULL;
483 
484 	host_machine = machines__find(machines, HOST_KERNEL_ID);
485 
486 	return findnew_guest_code(machine, host_machine, pid);
487 }
488 
489 void machines__process_guests(struct machines *machines,
490 			      machine__process_t process, void *data)
491 {
492 	struct rb_node *nd;
493 
494 	for (nd = rb_first_cached(&machines->guests); nd; nd = rb_next(nd)) {
495 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
496 		process(pos, data);
497 	}
498 }
499 
500 void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size)
501 {
502 	struct rb_node *node;
503 	struct machine *machine;
504 
505 	machines->host.id_hdr_size = id_hdr_size;
506 
507 	for (node = rb_first_cached(&machines->guests); node;
508 	     node = rb_next(node)) {
509 		machine = rb_entry(node, struct machine, rb_node);
510 		machine->id_hdr_size = id_hdr_size;
511 	}
512 
513 	return;
514 }
515 
516 static void machine__update_thread_pid(struct machine *machine,
517 				       struct thread *th, pid_t pid)
518 {
519 	struct thread *leader;
520 
521 	if (pid == thread__pid(th) || pid == -1 || thread__pid(th) != -1)
522 		return;
523 
524 	thread__set_pid(th, pid);
525 
526 	if (thread__pid(th) == thread__tid(th))
527 		return;
528 
529 	leader = __machine__findnew_thread(machine, thread__pid(th), thread__pid(th));
530 	if (!leader)
531 		goto out_err;
532 
533 	if (!thread__maps(leader))
534 		thread__set_maps(leader, maps__new(machine));
535 
536 	if (!thread__maps(leader))
537 		goto out_err;
538 
539 	if (thread__maps(th) == thread__maps(leader))
540 		goto out_put;
541 
542 	if (thread__maps(th)) {
543 		/*
544 		 * Maps are created from MMAP events which provide the pid and
545 		 * tid.  Consequently there never should be any maps on a thread
546 		 * with an unknown pid.  Just print an error if there are.
547 		 */
548 		if (!maps__empty(thread__maps(th)))
549 			pr_err("Discarding thread maps for %d:%d\n",
550 				thread__pid(th), thread__tid(th));
551 		maps__put(thread__maps(th));
552 	}
553 
554 	thread__set_maps(th, maps__get(thread__maps(leader)));
555 out_put:
556 	thread__put(leader);
557 	return;
558 out_err:
559 	pr_err("Failed to join map groups for %d:%d\n", thread__pid(th), thread__tid(th));
560 	goto out_put;
561 }
562 
563 /*
564  * Front-end cache - TID lookups come in blocks,
565  * so most of the time we dont have to look up
566  * the full rbtree:
567  */
568 static struct thread*
569 __threads__get_last_match(struct threads *threads, struct machine *machine,
570 			  int pid, int tid)
571 {
572 	struct thread *th;
573 
574 	th = threads->last_match;
575 	if (th != NULL) {
576 		if (thread__tid(th) == tid) {
577 			machine__update_thread_pid(machine, th, pid);
578 			return thread__get(th);
579 		}
580 		thread__put(threads->last_match);
581 		threads->last_match = NULL;
582 	}
583 
584 	return NULL;
585 }
586 
587 static struct thread*
588 threads__get_last_match(struct threads *threads, struct machine *machine,
589 			int pid, int tid)
590 {
591 	struct thread *th = NULL;
592 
593 	if (perf_singlethreaded)
594 		th = __threads__get_last_match(threads, machine, pid, tid);
595 
596 	return th;
597 }
598 
599 static void
600 __threads__set_last_match(struct threads *threads, struct thread *th)
601 {
602 	thread__put(threads->last_match);
603 	threads->last_match = thread__get(th);
604 }
605 
606 static void
607 threads__set_last_match(struct threads *threads, struct thread *th)
608 {
609 	if (perf_singlethreaded)
610 		__threads__set_last_match(threads, th);
611 }
612 
613 /*
614  * Caller must eventually drop thread->refcnt returned with a successful
615  * lookup/new thread inserted.
616  */
617 static struct thread *____machine__findnew_thread(struct machine *machine,
618 						  struct threads *threads,
619 						  pid_t pid, pid_t tid,
620 						  bool create)
621 {
622 	struct rb_node **p = &threads->entries.rb_root.rb_node;
623 	struct rb_node *parent = NULL;
624 	struct thread *th;
625 	struct thread_rb_node *nd;
626 	bool leftmost = true;
627 
628 	th = threads__get_last_match(threads, machine, pid, tid);
629 	if (th)
630 		return th;
631 
632 	while (*p != NULL) {
633 		parent = *p;
634 		th = rb_entry(parent, struct thread_rb_node, rb_node)->thread;
635 
636 		if (thread__tid(th) == tid) {
637 			threads__set_last_match(threads, th);
638 			machine__update_thread_pid(machine, th, pid);
639 			return thread__get(th);
640 		}
641 
642 		if (tid < thread__tid(th))
643 			p = &(*p)->rb_left;
644 		else {
645 			p = &(*p)->rb_right;
646 			leftmost = false;
647 		}
648 	}
649 
650 	if (!create)
651 		return NULL;
652 
653 	th = thread__new(pid, tid);
654 	if (th == NULL)
655 		return NULL;
656 
657 	nd = malloc(sizeof(*nd));
658 	if (nd == NULL) {
659 		thread__put(th);
660 		return NULL;
661 	}
662 	nd->thread = th;
663 
664 	rb_link_node(&nd->rb_node, parent, p);
665 	rb_insert_color_cached(&nd->rb_node, &threads->entries, leftmost);
666 	/*
667 	 * We have to initialize maps separately after rb tree is updated.
668 	 *
669 	 * The reason is that we call machine__findnew_thread within
670 	 * thread__init_maps to find the thread leader and that would screwed
671 	 * the rb tree.
672 	 */
673 	if (thread__init_maps(th, machine)) {
674 		pr_err("Thread init failed thread %d\n", pid);
675 		rb_erase_cached(&nd->rb_node, &threads->entries);
676 		RB_CLEAR_NODE(&nd->rb_node);
677 		free(nd);
678 		thread__put(th);
679 		return NULL;
680 	}
681 	/*
682 	 * It is now in the rbtree, get a ref
683 	 */
684 	threads__set_last_match(threads, th);
685 	++threads->nr;
686 
687 	return thread__get(th);
688 }
689 
690 struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
691 {
692 	return ____machine__findnew_thread(machine, machine__threads(machine, tid), pid, tid, true);
693 }
694 
695 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
696 				       pid_t tid)
697 {
698 	struct threads *threads = machine__threads(machine, tid);
699 	struct thread *th;
700 
701 	down_write(&threads->lock);
702 	th = __machine__findnew_thread(machine, pid, tid);
703 	up_write(&threads->lock);
704 	return th;
705 }
706 
707 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
708 				    pid_t tid)
709 {
710 	struct threads *threads = machine__threads(machine, tid);
711 	struct thread *th;
712 
713 	down_read(&threads->lock);
714 	th =  ____machine__findnew_thread(machine, threads, pid, tid, false);
715 	up_read(&threads->lock);
716 	return th;
717 }
718 
719 /*
720  * Threads are identified by pid and tid, and the idle task has pid == tid == 0.
721  * So here a single thread is created for that, but actually there is a separate
722  * idle task per cpu, so there should be one 'struct thread' per cpu, but there
723  * is only 1. That causes problems for some tools, requiring workarounds. For
724  * example get_idle_thread() in builtin-sched.c, or thread_stack__per_cpu().
725  */
726 struct thread *machine__idle_thread(struct machine *machine)
727 {
728 	struct thread *thread = machine__findnew_thread(machine, 0, 0);
729 
730 	if (!thread || thread__set_comm(thread, "swapper", 0) ||
731 	    thread__set_namespaces(thread, 0, NULL))
732 		pr_err("problem inserting idle task for machine pid %d\n", machine->pid);
733 
734 	return thread;
735 }
736 
737 struct comm *machine__thread_exec_comm(struct machine *machine,
738 				       struct thread *thread)
739 {
740 	if (machine->comm_exec)
741 		return thread__exec_comm(thread);
742 	else
743 		return thread__comm(thread);
744 }
745 
746 int machine__process_comm_event(struct machine *machine, union perf_event *event,
747 				struct perf_sample *sample)
748 {
749 	struct thread *thread = machine__findnew_thread(machine,
750 							event->comm.pid,
751 							event->comm.tid);
752 	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;
753 	int err = 0;
754 
755 	if (exec)
756 		machine->comm_exec = true;
757 
758 	if (dump_trace)
759 		perf_event__fprintf_comm(event, stdout);
760 
761 	if (thread == NULL ||
762 	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {
763 		dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
764 		err = -1;
765 	}
766 
767 	thread__put(thread);
768 
769 	return err;
770 }
771 
772 int machine__process_namespaces_event(struct machine *machine __maybe_unused,
773 				      union perf_event *event,
774 				      struct perf_sample *sample __maybe_unused)
775 {
776 	struct thread *thread = machine__findnew_thread(machine,
777 							event->namespaces.pid,
778 							event->namespaces.tid);
779 	int err = 0;
780 
781 	WARN_ONCE(event->namespaces.nr_namespaces > NR_NAMESPACES,
782 		  "\nWARNING: kernel seems to support more namespaces than perf"
783 		  " tool.\nTry updating the perf tool..\n\n");
784 
785 	WARN_ONCE(event->namespaces.nr_namespaces < NR_NAMESPACES,
786 		  "\nWARNING: perf tool seems to support more namespaces than"
787 		  " the kernel.\nTry updating the kernel..\n\n");
788 
789 	if (dump_trace)
790 		perf_event__fprintf_namespaces(event, stdout);
791 
792 	if (thread == NULL ||
793 	    thread__set_namespaces(thread, sample->time, &event->namespaces)) {
794 		dump_printf("problem processing PERF_RECORD_NAMESPACES, skipping event.\n");
795 		err = -1;
796 	}
797 
798 	thread__put(thread);
799 
800 	return err;
801 }
802 
803 int machine__process_cgroup_event(struct machine *machine,
804 				  union perf_event *event,
805 				  struct perf_sample *sample __maybe_unused)
806 {
807 	struct cgroup *cgrp;
808 
809 	if (dump_trace)
810 		perf_event__fprintf_cgroup(event, stdout);
811 
812 	cgrp = cgroup__findnew(machine->env, event->cgroup.id, event->cgroup.path);
813 	if (cgrp == NULL)
814 		return -ENOMEM;
815 
816 	return 0;
817 }
818 
819 int machine__process_lost_event(struct machine *machine __maybe_unused,
820 				union perf_event *event, struct perf_sample *sample __maybe_unused)
821 {
822 	dump_printf(": id:%" PRI_lu64 ": lost:%" PRI_lu64 "\n",
823 		    event->lost.id, event->lost.lost);
824 	return 0;
825 }
826 
827 int machine__process_lost_samples_event(struct machine *machine __maybe_unused,
828 					union perf_event *event, struct perf_sample *sample)
829 {
830 	dump_printf(": id:%" PRIu64 ": lost samples :%" PRI_lu64 "\n",
831 		    sample->id, event->lost_samples.lost);
832 	return 0;
833 }
834 
835 static struct dso *machine__findnew_module_dso(struct machine *machine,
836 					       struct kmod_path *m,
837 					       const char *filename)
838 {
839 	struct dso *dso;
840 
841 	down_write(&machine->dsos.lock);
842 
843 	dso = __dsos__find(&machine->dsos, m->name, true);
844 	if (!dso) {
845 		dso = __dsos__addnew(&machine->dsos, m->name);
846 		if (dso == NULL)
847 			goto out_unlock;
848 
849 		dso__set_module_info(dso, m, machine);
850 		dso__set_long_name(dso, strdup(filename), true);
851 		dso->kernel = DSO_SPACE__KERNEL;
852 	}
853 
854 	dso__get(dso);
855 out_unlock:
856 	up_write(&machine->dsos.lock);
857 	return dso;
858 }
859 
860 int machine__process_aux_event(struct machine *machine __maybe_unused,
861 			       union perf_event *event)
862 {
863 	if (dump_trace)
864 		perf_event__fprintf_aux(event, stdout);
865 	return 0;
866 }
867 
868 int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
869 					union perf_event *event)
870 {
871 	if (dump_trace)
872 		perf_event__fprintf_itrace_start(event, stdout);
873 	return 0;
874 }
875 
876 int machine__process_aux_output_hw_id_event(struct machine *machine __maybe_unused,
877 					    union perf_event *event)
878 {
879 	if (dump_trace)
880 		perf_event__fprintf_aux_output_hw_id(event, stdout);
881 	return 0;
882 }
883 
884 int machine__process_switch_event(struct machine *machine __maybe_unused,
885 				  union perf_event *event)
886 {
887 	if (dump_trace)
888 		perf_event__fprintf_switch(event, stdout);
889 	return 0;
890 }
891 
892 static int machine__process_ksymbol_register(struct machine *machine,
893 					     union perf_event *event,
894 					     struct perf_sample *sample __maybe_unused)
895 {
896 	struct symbol *sym;
897 	struct dso *dso;
898 	struct map *map = maps__find(machine__kernel_maps(machine), event->ksymbol.addr);
899 	bool put_map = false;
900 	int err = 0;
901 
902 	if (!map) {
903 		dso = dso__new(event->ksymbol.name);
904 
905 		if (!dso) {
906 			err = -ENOMEM;
907 			goto out;
908 		}
909 		dso->kernel = DSO_SPACE__KERNEL;
910 		map = map__new2(0, dso);
911 		dso__put(dso);
912 		if (!map) {
913 			err = -ENOMEM;
914 			goto out;
915 		}
916 		/*
917 		 * The inserted map has a get on it, we need to put to release
918 		 * the reference count here, but do it after all accesses are
919 		 * done.
920 		 */
921 		put_map = true;
922 		if (event->ksymbol.ksym_type == PERF_RECORD_KSYMBOL_TYPE_OOL) {
923 			dso->binary_type = DSO_BINARY_TYPE__OOL;
924 			dso->data.file_size = event->ksymbol.len;
925 			dso__set_loaded(dso);
926 		}
927 
928 		map__set_start(map, event->ksymbol.addr);
929 		map__set_end(map, map__start(map) + event->ksymbol.len);
930 		err = maps__insert(machine__kernel_maps(machine), map);
931 		if (err) {
932 			err = -ENOMEM;
933 			goto out;
934 		}
935 
936 		dso__set_loaded(dso);
937 
938 		if (is_bpf_image(event->ksymbol.name)) {
939 			dso->binary_type = DSO_BINARY_TYPE__BPF_IMAGE;
940 			dso__set_long_name(dso, "", false);
941 		}
942 	} else {
943 		dso = map__dso(map);
944 	}
945 
946 	sym = symbol__new(map__map_ip(map, map__start(map)),
947 			  event->ksymbol.len,
948 			  0, 0, event->ksymbol.name);
949 	if (!sym) {
950 		err = -ENOMEM;
951 		goto out;
952 	}
953 	dso__insert_symbol(dso, sym);
954 out:
955 	if (put_map)
956 		map__put(map);
957 	return err;
958 }
959 
960 static int machine__process_ksymbol_unregister(struct machine *machine,
961 					       union perf_event *event,
962 					       struct perf_sample *sample __maybe_unused)
963 {
964 	struct symbol *sym;
965 	struct map *map;
966 
967 	map = maps__find(machine__kernel_maps(machine), event->ksymbol.addr);
968 	if (!map)
969 		return 0;
970 
971 	if (!RC_CHK_EQUAL(map, machine->vmlinux_map))
972 		maps__remove(machine__kernel_maps(machine), map);
973 	else {
974 		struct dso *dso = map__dso(map);
975 
976 		sym = dso__find_symbol(dso, map__map_ip(map, map__start(map)));
977 		if (sym)
978 			dso__delete_symbol(dso, sym);
979 	}
980 
981 	return 0;
982 }
983 
984 int machine__process_ksymbol(struct machine *machine __maybe_unused,
985 			     union perf_event *event,
986 			     struct perf_sample *sample)
987 {
988 	if (dump_trace)
989 		perf_event__fprintf_ksymbol(event, stdout);
990 
991 	if (event->ksymbol.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
992 		return machine__process_ksymbol_unregister(machine, event,
993 							   sample);
994 	return machine__process_ksymbol_register(machine, event, sample);
995 }
996 
997 int machine__process_text_poke(struct machine *machine, union perf_event *event,
998 			       struct perf_sample *sample __maybe_unused)
999 {
1000 	struct map *map = maps__find(machine__kernel_maps(machine), event->text_poke.addr);
1001 	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1002 	struct dso *dso = map ? map__dso(map) : NULL;
1003 
1004 	if (dump_trace)
1005 		perf_event__fprintf_text_poke(event, machine, stdout);
1006 
1007 	if (!event->text_poke.new_len)
1008 		return 0;
1009 
1010 	if (cpumode != PERF_RECORD_MISC_KERNEL) {
1011 		pr_debug("%s: unsupported cpumode - ignoring\n", __func__);
1012 		return 0;
1013 	}
1014 
1015 	if (dso) {
1016 		u8 *new_bytes = event->text_poke.bytes + event->text_poke.old_len;
1017 		int ret;
1018 
1019 		/*
1020 		 * Kernel maps might be changed when loading symbols so loading
1021 		 * must be done prior to using kernel maps.
1022 		 */
1023 		map__load(map);
1024 		ret = dso__data_write_cache_addr(dso, map, machine,
1025 						 event->text_poke.addr,
1026 						 new_bytes,
1027 						 event->text_poke.new_len);
1028 		if (ret != event->text_poke.new_len)
1029 			pr_debug("Failed to write kernel text poke at %#" PRI_lx64 "\n",
1030 				 event->text_poke.addr);
1031 	} else {
1032 		pr_debug("Failed to find kernel text poke address map for %#" PRI_lx64 "\n",
1033 			 event->text_poke.addr);
1034 	}
1035 
1036 	return 0;
1037 }
1038 
1039 static struct map *machine__addnew_module_map(struct machine *machine, u64 start,
1040 					      const char *filename)
1041 {
1042 	struct map *map = NULL;
1043 	struct kmod_path m;
1044 	struct dso *dso;
1045 	int err;
1046 
1047 	if (kmod_path__parse_name(&m, filename))
1048 		return NULL;
1049 
1050 	dso = machine__findnew_module_dso(machine, &m, filename);
1051 	if (dso == NULL)
1052 		goto out;
1053 
1054 	map = map__new2(start, dso);
1055 	if (map == NULL)
1056 		goto out;
1057 
1058 	err = maps__insert(machine__kernel_maps(machine), map);
1059 	/* If maps__insert failed, return NULL. */
1060 	if (err) {
1061 		map__put(map);
1062 		map = NULL;
1063 	}
1064 out:
1065 	/* put the dso here, corresponding to  machine__findnew_module_dso */
1066 	dso__put(dso);
1067 	zfree(&m.name);
1068 	return map;
1069 }
1070 
1071 size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
1072 {
1073 	struct rb_node *nd;
1074 	size_t ret = __dsos__fprintf(&machines->host.dsos.head, fp);
1075 
1076 	for (nd = rb_first_cached(&machines->guests); nd; nd = rb_next(nd)) {
1077 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
1078 		ret += __dsos__fprintf(&pos->dsos.head, fp);
1079 	}
1080 
1081 	return ret;
1082 }
1083 
1084 size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,
1085 				     bool (skip)(struct dso *dso, int parm), int parm)
1086 {
1087 	return __dsos__fprintf_buildid(&m->dsos.head, fp, skip, parm);
1088 }
1089 
1090 size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,
1091 				     bool (skip)(struct dso *dso, int parm), int parm)
1092 {
1093 	struct rb_node *nd;
1094 	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);
1095 
1096 	for (nd = rb_first_cached(&machines->guests); nd; nd = rb_next(nd)) {
1097 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
1098 		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
1099 	}
1100 	return ret;
1101 }
1102 
1103 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
1104 {
1105 	int i;
1106 	size_t printed = 0;
1107 	struct dso *kdso = machine__kernel_dso(machine);
1108 
1109 	if (kdso->has_build_id) {
1110 		char filename[PATH_MAX];
1111 		if (dso__build_id_filename(kdso, filename, sizeof(filename),
1112 					   false))
1113 			printed += fprintf(fp, "[0] %s\n", filename);
1114 	}
1115 
1116 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
1117 		printed += fprintf(fp, "[%d] %s\n",
1118 				   i + kdso->has_build_id, vmlinux_path[i]);
1119 
1120 	return printed;
1121 }
1122 
1123 size_t machine__fprintf(struct machine *machine, FILE *fp)
1124 {
1125 	struct rb_node *nd;
1126 	size_t ret;
1127 	int i;
1128 
1129 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
1130 		struct threads *threads = &machine->threads[i];
1131 
1132 		down_read(&threads->lock);
1133 
1134 		ret = fprintf(fp, "Threads: %u\n", threads->nr);
1135 
1136 		for (nd = rb_first_cached(&threads->entries); nd;
1137 		     nd = rb_next(nd)) {
1138 			struct thread *pos = rb_entry(nd, struct thread_rb_node, rb_node)->thread;
1139 
1140 			ret += thread__fprintf(pos, fp);
1141 		}
1142 
1143 		up_read(&threads->lock);
1144 	}
1145 	return ret;
1146 }
1147 
1148 static struct dso *machine__get_kernel(struct machine *machine)
1149 {
1150 	const char *vmlinux_name = machine->mmap_name;
1151 	struct dso *kernel;
1152 
1153 	if (machine__is_host(machine)) {
1154 		if (symbol_conf.vmlinux_name)
1155 			vmlinux_name = symbol_conf.vmlinux_name;
1156 
1157 		kernel = machine__findnew_kernel(machine, vmlinux_name,
1158 						 "[kernel]", DSO_SPACE__KERNEL);
1159 	} else {
1160 		if (symbol_conf.default_guest_vmlinux_name)
1161 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
1162 
1163 		kernel = machine__findnew_kernel(machine, vmlinux_name,
1164 						 "[guest.kernel]",
1165 						 DSO_SPACE__KERNEL_GUEST);
1166 	}
1167 
1168 	if (kernel != NULL && (!kernel->has_build_id))
1169 		dso__read_running_kernel_build_id(kernel, machine);
1170 
1171 	return kernel;
1172 }
1173 
1174 void machine__get_kallsyms_filename(struct machine *machine, char *buf,
1175 				    size_t bufsz)
1176 {
1177 	if (machine__is_default_guest(machine))
1178 		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
1179 	else
1180 		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
1181 }
1182 
1183 const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
1184 
1185 /* Figure out the start address of kernel map from /proc/kallsyms.
1186  * Returns the name of the start symbol in *symbol_name. Pass in NULL as
1187  * symbol_name if it's not that important.
1188  */
1189 static int machine__get_running_kernel_start(struct machine *machine,
1190 					     const char **symbol_name,
1191 					     u64 *start, u64 *end)
1192 {
1193 	char filename[PATH_MAX];
1194 	int i, err = -1;
1195 	const char *name;
1196 	u64 addr = 0;
1197 
1198 	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
1199 
1200 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1201 		return 0;
1202 
1203 	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
1204 		err = kallsyms__get_function_start(filename, name, &addr);
1205 		if (!err)
1206 			break;
1207 	}
1208 
1209 	if (err)
1210 		return -1;
1211 
1212 	if (symbol_name)
1213 		*symbol_name = name;
1214 
1215 	*start = addr;
1216 
1217 	err = kallsyms__get_symbol_start(filename, "_edata", &addr);
1218 	if (err)
1219 		err = kallsyms__get_function_start(filename, "_etext", &addr);
1220 	if (!err)
1221 		*end = addr;
1222 
1223 	return 0;
1224 }
1225 
1226 int machine__create_extra_kernel_map(struct machine *machine,
1227 				     struct dso *kernel,
1228 				     struct extra_kernel_map *xm)
1229 {
1230 	struct kmap *kmap;
1231 	struct map *map;
1232 	int err;
1233 
1234 	map = map__new2(xm->start, kernel);
1235 	if (!map)
1236 		return -ENOMEM;
1237 
1238 	map__set_end(map, xm->end);
1239 	map__set_pgoff(map, xm->pgoff);
1240 
1241 	kmap = map__kmap(map);
1242 
1243 	strlcpy(kmap->name, xm->name, KMAP_NAME_LEN);
1244 
1245 	err = maps__insert(machine__kernel_maps(machine), map);
1246 
1247 	if (!err) {
1248 		pr_debug2("Added extra kernel map %s %" PRIx64 "-%" PRIx64 "\n",
1249 			kmap->name, map__start(map), map__end(map));
1250 	}
1251 
1252 	map__put(map);
1253 
1254 	return err;
1255 }
1256 
1257 static u64 find_entry_trampoline(struct dso *dso)
1258 {
1259 	/* Duplicates are removed so lookup all aliases */
1260 	const char *syms[] = {
1261 		"_entry_trampoline",
1262 		"__entry_trampoline_start",
1263 		"entry_SYSCALL_64_trampoline",
1264 	};
1265 	struct symbol *sym = dso__first_symbol(dso);
1266 	unsigned int i;
1267 
1268 	for (; sym; sym = dso__next_symbol(sym)) {
1269 		if (sym->binding != STB_GLOBAL)
1270 			continue;
1271 		for (i = 0; i < ARRAY_SIZE(syms); i++) {
1272 			if (!strcmp(sym->name, syms[i]))
1273 				return sym->start;
1274 		}
1275 	}
1276 
1277 	return 0;
1278 }
1279 
1280 /*
1281  * These values can be used for kernels that do not have symbols for the entry
1282  * trampolines in kallsyms.
1283  */
1284 #define X86_64_CPU_ENTRY_AREA_PER_CPU	0xfffffe0000000000ULL
1285 #define X86_64_CPU_ENTRY_AREA_SIZE	0x2c000
1286 #define X86_64_ENTRY_TRAMPOLINE		0x6000
1287 
1288 /* Map x86_64 PTI entry trampolines */
1289 int machine__map_x86_64_entry_trampolines(struct machine *machine,
1290 					  struct dso *kernel)
1291 {
1292 	struct maps *kmaps = machine__kernel_maps(machine);
1293 	int nr_cpus_avail, cpu;
1294 	bool found = false;
1295 	struct map_rb_node *rb_node;
1296 	u64 pgoff;
1297 
1298 	/*
1299 	 * In the vmlinux case, pgoff is a virtual address which must now be
1300 	 * mapped to a vmlinux offset.
1301 	 */
1302 	maps__for_each_entry(kmaps, rb_node) {
1303 		struct map *dest_map, *map = rb_node->map;
1304 		struct kmap *kmap = __map__kmap(map);
1305 
1306 		if (!kmap || !is_entry_trampoline(kmap->name))
1307 			continue;
1308 
1309 		dest_map = maps__find(kmaps, map__pgoff(map));
1310 		if (dest_map != map)
1311 			map__set_pgoff(map, map__map_ip(dest_map, map__pgoff(map)));
1312 		found = true;
1313 	}
1314 	if (found || machine->trampolines_mapped)
1315 		return 0;
1316 
1317 	pgoff = find_entry_trampoline(kernel);
1318 	if (!pgoff)
1319 		return 0;
1320 
1321 	nr_cpus_avail = machine__nr_cpus_avail(machine);
1322 
1323 	/* Add a 1 page map for each CPU's entry trampoline */
1324 	for (cpu = 0; cpu < nr_cpus_avail; cpu++) {
1325 		u64 va = X86_64_CPU_ENTRY_AREA_PER_CPU +
1326 			 cpu * X86_64_CPU_ENTRY_AREA_SIZE +
1327 			 X86_64_ENTRY_TRAMPOLINE;
1328 		struct extra_kernel_map xm = {
1329 			.start = va,
1330 			.end   = va + page_size,
1331 			.pgoff = pgoff,
1332 		};
1333 
1334 		strlcpy(xm.name, ENTRY_TRAMPOLINE_NAME, KMAP_NAME_LEN);
1335 
1336 		if (machine__create_extra_kernel_map(machine, kernel, &xm) < 0)
1337 			return -1;
1338 	}
1339 
1340 	machine->trampolines_mapped = nr_cpus_avail;
1341 
1342 	return 0;
1343 }
1344 
1345 int __weak machine__create_extra_kernel_maps(struct machine *machine __maybe_unused,
1346 					     struct dso *kernel __maybe_unused)
1347 {
1348 	return 0;
1349 }
1350 
1351 static int
1352 __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
1353 {
1354 	/* In case of renewal the kernel map, destroy previous one */
1355 	machine__destroy_kernel_maps(machine);
1356 
1357 	map__put(machine->vmlinux_map);
1358 	machine->vmlinux_map = map__new2(0, kernel);
1359 	if (machine->vmlinux_map == NULL)
1360 		return -ENOMEM;
1361 
1362 	map__set_map_ip(machine->vmlinux_map, identity__map_ip);
1363 	map__set_unmap_ip(machine->vmlinux_map, identity__map_ip);
1364 	return maps__insert(machine__kernel_maps(machine), machine->vmlinux_map);
1365 }
1366 
1367 void machine__destroy_kernel_maps(struct machine *machine)
1368 {
1369 	struct kmap *kmap;
1370 	struct map *map = machine__kernel_map(machine);
1371 
1372 	if (map == NULL)
1373 		return;
1374 
1375 	kmap = map__kmap(map);
1376 	maps__remove(machine__kernel_maps(machine), map);
1377 	if (kmap && kmap->ref_reloc_sym) {
1378 		zfree((char **)&kmap->ref_reloc_sym->name);
1379 		zfree(&kmap->ref_reloc_sym);
1380 	}
1381 
1382 	map__zput(machine->vmlinux_map);
1383 }
1384 
1385 int machines__create_guest_kernel_maps(struct machines *machines)
1386 {
1387 	int ret = 0;
1388 	struct dirent **namelist = NULL;
1389 	int i, items = 0;
1390 	char path[PATH_MAX];
1391 	pid_t pid;
1392 	char *endp;
1393 
1394 	if (symbol_conf.default_guest_vmlinux_name ||
1395 	    symbol_conf.default_guest_modules ||
1396 	    symbol_conf.default_guest_kallsyms) {
1397 		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
1398 	}
1399 
1400 	if (symbol_conf.guestmount) {
1401 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
1402 		if (items <= 0)
1403 			return -ENOENT;
1404 		for (i = 0; i < items; i++) {
1405 			if (!isdigit(namelist[i]->d_name[0])) {
1406 				/* Filter out . and .. */
1407 				continue;
1408 			}
1409 			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
1410 			if ((*endp != '\0') ||
1411 			    (endp == namelist[i]->d_name) ||
1412 			    (errno == ERANGE)) {
1413 				pr_debug("invalid directory (%s). Skipping.\n",
1414 					 namelist[i]->d_name);
1415 				continue;
1416 			}
1417 			sprintf(path, "%s/%s/proc/kallsyms",
1418 				symbol_conf.guestmount,
1419 				namelist[i]->d_name);
1420 			ret = access(path, R_OK);
1421 			if (ret) {
1422 				pr_debug("Can't access file %s\n", path);
1423 				goto failure;
1424 			}
1425 			machines__create_kernel_maps(machines, pid);
1426 		}
1427 failure:
1428 		free(namelist);
1429 	}
1430 
1431 	return ret;
1432 }
1433 
1434 void machines__destroy_kernel_maps(struct machines *machines)
1435 {
1436 	struct rb_node *next = rb_first_cached(&machines->guests);
1437 
1438 	machine__destroy_kernel_maps(&machines->host);
1439 
1440 	while (next) {
1441 		struct machine *pos = rb_entry(next, struct machine, rb_node);
1442 
1443 		next = rb_next(&pos->rb_node);
1444 		rb_erase_cached(&pos->rb_node, &machines->guests);
1445 		machine__delete(pos);
1446 	}
1447 }
1448 
1449 int machines__create_kernel_maps(struct machines *machines, pid_t pid)
1450 {
1451 	struct machine *machine = machines__findnew(machines, pid);
1452 
1453 	if (machine == NULL)
1454 		return -1;
1455 
1456 	return machine__create_kernel_maps(machine);
1457 }
1458 
1459 int machine__load_kallsyms(struct machine *machine, const char *filename)
1460 {
1461 	struct map *map = machine__kernel_map(machine);
1462 	struct dso *dso = map__dso(map);
1463 	int ret = __dso__load_kallsyms(dso, filename, map, true);
1464 
1465 	if (ret > 0) {
1466 		dso__set_loaded(dso);
1467 		/*
1468 		 * Since /proc/kallsyms will have multiple sessions for the
1469 		 * kernel, with modules between them, fixup the end of all
1470 		 * sections.
1471 		 */
1472 		maps__fixup_end(machine__kernel_maps(machine));
1473 	}
1474 
1475 	return ret;
1476 }
1477 
1478 int machine__load_vmlinux_path(struct machine *machine)
1479 {
1480 	struct map *map = machine__kernel_map(machine);
1481 	struct dso *dso = map__dso(map);
1482 	int ret = dso__load_vmlinux_path(dso, map);
1483 
1484 	if (ret > 0)
1485 		dso__set_loaded(dso);
1486 
1487 	return ret;
1488 }
1489 
1490 static char *get_kernel_version(const char *root_dir)
1491 {
1492 	char version[PATH_MAX];
1493 	FILE *file;
1494 	char *name, *tmp;
1495 	const char *prefix = "Linux version ";
1496 
1497 	sprintf(version, "%s/proc/version", root_dir);
1498 	file = fopen(version, "r");
1499 	if (!file)
1500 		return NULL;
1501 
1502 	tmp = fgets(version, sizeof(version), file);
1503 	fclose(file);
1504 	if (!tmp)
1505 		return NULL;
1506 
1507 	name = strstr(version, prefix);
1508 	if (!name)
1509 		return NULL;
1510 	name += strlen(prefix);
1511 	tmp = strchr(name, ' ');
1512 	if (tmp)
1513 		*tmp = '\0';
1514 
1515 	return strdup(name);
1516 }
1517 
1518 static bool is_kmod_dso(struct dso *dso)
1519 {
1520 	return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1521 	       dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
1522 }
1523 
1524 static int maps__set_module_path(struct maps *maps, const char *path, struct kmod_path *m)
1525 {
1526 	char *long_name;
1527 	struct dso *dso;
1528 	struct map *map = maps__find_by_name(maps, m->name);
1529 
1530 	if (map == NULL)
1531 		return 0;
1532 
1533 	long_name = strdup(path);
1534 	if (long_name == NULL)
1535 		return -ENOMEM;
1536 
1537 	dso = map__dso(map);
1538 	dso__set_long_name(dso, long_name, true);
1539 	dso__kernel_module_get_build_id(dso, "");
1540 
1541 	/*
1542 	 * Full name could reveal us kmod compression, so
1543 	 * we need to update the symtab_type if needed.
1544 	 */
1545 	if (m->comp && is_kmod_dso(dso)) {
1546 		dso->symtab_type++;
1547 		dso->comp = m->comp;
1548 	}
1549 
1550 	return 0;
1551 }
1552 
1553 static int maps__set_modules_path_dir(struct maps *maps, const char *dir_name, int depth)
1554 {
1555 	struct dirent *dent;
1556 	DIR *dir = opendir(dir_name);
1557 	int ret = 0;
1558 
1559 	if (!dir) {
1560 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
1561 		return -1;
1562 	}
1563 
1564 	while ((dent = readdir(dir)) != NULL) {
1565 		char path[PATH_MAX];
1566 		struct stat st;
1567 
1568 		/*sshfs might return bad dent->d_type, so we have to stat*/
1569 		path__join(path, sizeof(path), dir_name, dent->d_name);
1570 		if (stat(path, &st))
1571 			continue;
1572 
1573 		if (S_ISDIR(st.st_mode)) {
1574 			if (!strcmp(dent->d_name, ".") ||
1575 			    !strcmp(dent->d_name, ".."))
1576 				continue;
1577 
1578 			/* Do not follow top-level source and build symlinks */
1579 			if (depth == 0) {
1580 				if (!strcmp(dent->d_name, "source") ||
1581 				    !strcmp(dent->d_name, "build"))
1582 					continue;
1583 			}
1584 
1585 			ret = maps__set_modules_path_dir(maps, path, depth + 1);
1586 			if (ret < 0)
1587 				goto out;
1588 		} else {
1589 			struct kmod_path m;
1590 
1591 			ret = kmod_path__parse_name(&m, dent->d_name);
1592 			if (ret)
1593 				goto out;
1594 
1595 			if (m.kmod)
1596 				ret = maps__set_module_path(maps, path, &m);
1597 
1598 			zfree(&m.name);
1599 
1600 			if (ret)
1601 				goto out;
1602 		}
1603 	}
1604 
1605 out:
1606 	closedir(dir);
1607 	return ret;
1608 }
1609 
1610 static int machine__set_modules_path(struct machine *machine)
1611 {
1612 	char *version;
1613 	char modules_path[PATH_MAX];
1614 
1615 	version = get_kernel_version(machine->root_dir);
1616 	if (!version)
1617 		return -1;
1618 
1619 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",
1620 		 machine->root_dir, version);
1621 	free(version);
1622 
1623 	return maps__set_modules_path_dir(machine__kernel_maps(machine), modules_path, 0);
1624 }
1625 int __weak arch__fix_module_text_start(u64 *start __maybe_unused,
1626 				u64 *size __maybe_unused,
1627 				const char *name __maybe_unused)
1628 {
1629 	return 0;
1630 }
1631 
1632 static int machine__create_module(void *arg, const char *name, u64 start,
1633 				  u64 size)
1634 {
1635 	struct machine *machine = arg;
1636 	struct map *map;
1637 
1638 	if (arch__fix_module_text_start(&start, &size, name) < 0)
1639 		return -1;
1640 
1641 	map = machine__addnew_module_map(machine, start, name);
1642 	if (map == NULL)
1643 		return -1;
1644 	map__set_end(map, start + size);
1645 
1646 	dso__kernel_module_get_build_id(map__dso(map), machine->root_dir);
1647 	map__put(map);
1648 	return 0;
1649 }
1650 
1651 static int machine__create_modules(struct machine *machine)
1652 {
1653 	const char *modules;
1654 	char path[PATH_MAX];
1655 
1656 	if (machine__is_default_guest(machine)) {
1657 		modules = symbol_conf.default_guest_modules;
1658 	} else {
1659 		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);
1660 		modules = path;
1661 	}
1662 
1663 	if (symbol__restricted_filename(modules, "/proc/modules"))
1664 		return -1;
1665 
1666 	if (modules__parse(modules, machine, machine__create_module))
1667 		return -1;
1668 
1669 	if (!machine__set_modules_path(machine))
1670 		return 0;
1671 
1672 	pr_debug("Problems setting modules path maps, continuing anyway...\n");
1673 
1674 	return 0;
1675 }
1676 
1677 static void machine__set_kernel_mmap(struct machine *machine,
1678 				     u64 start, u64 end)
1679 {
1680 	map__set_start(machine->vmlinux_map, start);
1681 	map__set_end(machine->vmlinux_map, end);
1682 	/*
1683 	 * Be a bit paranoid here, some perf.data file came with
1684 	 * a zero sized synthesized MMAP event for the kernel.
1685 	 */
1686 	if (start == 0 && end == 0)
1687 		map__set_end(machine->vmlinux_map, ~0ULL);
1688 }
1689 
1690 static int machine__update_kernel_mmap(struct machine *machine,
1691 				     u64 start, u64 end)
1692 {
1693 	struct map *orig, *updated;
1694 	int err;
1695 
1696 	orig = machine->vmlinux_map;
1697 	updated = map__get(orig);
1698 
1699 	machine->vmlinux_map = updated;
1700 	machine__set_kernel_mmap(machine, start, end);
1701 	maps__remove(machine__kernel_maps(machine), orig);
1702 	err = maps__insert(machine__kernel_maps(machine), updated);
1703 	map__put(orig);
1704 
1705 	return err;
1706 }
1707 
1708 int machine__create_kernel_maps(struct machine *machine)
1709 {
1710 	struct dso *kernel = machine__get_kernel(machine);
1711 	const char *name = NULL;
1712 	u64 start = 0, end = ~0ULL;
1713 	int ret;
1714 
1715 	if (kernel == NULL)
1716 		return -1;
1717 
1718 	ret = __machine__create_kernel_maps(machine, kernel);
1719 	if (ret < 0)
1720 		goto out_put;
1721 
1722 	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
1723 		if (machine__is_host(machine))
1724 			pr_debug("Problems creating module maps, "
1725 				 "continuing anyway...\n");
1726 		else
1727 			pr_debug("Problems creating module maps for guest %d, "
1728 				 "continuing anyway...\n", machine->pid);
1729 	}
1730 
1731 	if (!machine__get_running_kernel_start(machine, &name, &start, &end)) {
1732 		if (name &&
1733 		    map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, start)) {
1734 			machine__destroy_kernel_maps(machine);
1735 			ret = -1;
1736 			goto out_put;
1737 		}
1738 
1739 		/*
1740 		 * we have a real start address now, so re-order the kmaps
1741 		 * assume it's the last in the kmaps
1742 		 */
1743 		ret = machine__update_kernel_mmap(machine, start, end);
1744 		if (ret < 0)
1745 			goto out_put;
1746 	}
1747 
1748 	if (machine__create_extra_kernel_maps(machine, kernel))
1749 		pr_debug("Problems creating extra kernel maps, continuing anyway...\n");
1750 
1751 	if (end == ~0ULL) {
1752 		/* update end address of the kernel map using adjacent module address */
1753 		struct map_rb_node *rb_node = maps__find_node(machine__kernel_maps(machine),
1754 							machine__kernel_map(machine));
1755 		struct map_rb_node *next = map_rb_node__next(rb_node);
1756 
1757 		if (next)
1758 			machine__set_kernel_mmap(machine, start, map__start(next->map));
1759 	}
1760 
1761 out_put:
1762 	dso__put(kernel);
1763 	return ret;
1764 }
1765 
1766 static bool machine__uses_kcore(struct machine *machine)
1767 {
1768 	struct dso *dso;
1769 
1770 	list_for_each_entry(dso, &machine->dsos.head, node) {
1771 		if (dso__is_kcore(dso))
1772 			return true;
1773 	}
1774 
1775 	return false;
1776 }
1777 
1778 static bool perf_event__is_extra_kernel_mmap(struct machine *machine,
1779 					     struct extra_kernel_map *xm)
1780 {
1781 	return machine__is(machine, "x86_64") &&
1782 	       is_entry_trampoline(xm->name);
1783 }
1784 
1785 static int machine__process_extra_kernel_map(struct machine *machine,
1786 					     struct extra_kernel_map *xm)
1787 {
1788 	struct dso *kernel = machine__kernel_dso(machine);
1789 
1790 	if (kernel == NULL)
1791 		return -1;
1792 
1793 	return machine__create_extra_kernel_map(machine, kernel, xm);
1794 }
1795 
1796 static int machine__process_kernel_mmap_event(struct machine *machine,
1797 					      struct extra_kernel_map *xm,
1798 					      struct build_id *bid)
1799 {
1800 	enum dso_space_type dso_space;
1801 	bool is_kernel_mmap;
1802 	const char *mmap_name = machine->mmap_name;
1803 
1804 	/* If we have maps from kcore then we do not need or want any others */
1805 	if (machine__uses_kcore(machine))
1806 		return 0;
1807 
1808 	if (machine__is_host(machine))
1809 		dso_space = DSO_SPACE__KERNEL;
1810 	else
1811 		dso_space = DSO_SPACE__KERNEL_GUEST;
1812 
1813 	is_kernel_mmap = memcmp(xm->name, mmap_name, strlen(mmap_name) - 1) == 0;
1814 	if (!is_kernel_mmap && !machine__is_host(machine)) {
1815 		/*
1816 		 * If the event was recorded inside the guest and injected into
1817 		 * the host perf.data file, then it will match a host mmap_name,
1818 		 * so try that - see machine__set_mmap_name().
1819 		 */
1820 		mmap_name = "[kernel.kallsyms]";
1821 		is_kernel_mmap = memcmp(xm->name, mmap_name, strlen(mmap_name) - 1) == 0;
1822 	}
1823 	if (xm->name[0] == '/' ||
1824 	    (!is_kernel_mmap && xm->name[0] == '[')) {
1825 		struct map *map = machine__addnew_module_map(machine, xm->start, xm->name);
1826 
1827 		if (map == NULL)
1828 			goto out_problem;
1829 
1830 		map__set_end(map, map__start(map) + xm->end - xm->start);
1831 
1832 		if (build_id__is_defined(bid))
1833 			dso__set_build_id(map__dso(map), bid);
1834 
1835 		map__put(map);
1836 	} else if (is_kernel_mmap) {
1837 		const char *symbol_name = xm->name + strlen(mmap_name);
1838 		/*
1839 		 * Should be there already, from the build-id table in
1840 		 * the header.
1841 		 */
1842 		struct dso *kernel = NULL;
1843 		struct dso *dso;
1844 
1845 		down_read(&machine->dsos.lock);
1846 
1847 		list_for_each_entry(dso, &machine->dsos.head, node) {
1848 
1849 			/*
1850 			 * The cpumode passed to is_kernel_module is not the
1851 			 * cpumode of *this* event. If we insist on passing
1852 			 * correct cpumode to is_kernel_module, we should
1853 			 * record the cpumode when we adding this dso to the
1854 			 * linked list.
1855 			 *
1856 			 * However we don't really need passing correct
1857 			 * cpumode.  We know the correct cpumode must be kernel
1858 			 * mode (if not, we should not link it onto kernel_dsos
1859 			 * list).
1860 			 *
1861 			 * Therefore, we pass PERF_RECORD_MISC_CPUMODE_UNKNOWN.
1862 			 * is_kernel_module() treats it as a kernel cpumode.
1863 			 */
1864 
1865 			if (!dso->kernel ||
1866 			    is_kernel_module(dso->long_name,
1867 					     PERF_RECORD_MISC_CPUMODE_UNKNOWN))
1868 				continue;
1869 
1870 
1871 			kernel = dso__get(dso);
1872 			break;
1873 		}
1874 
1875 		up_read(&machine->dsos.lock);
1876 
1877 		if (kernel == NULL)
1878 			kernel = machine__findnew_dso(machine, machine->mmap_name);
1879 		if (kernel == NULL)
1880 			goto out_problem;
1881 
1882 		kernel->kernel = dso_space;
1883 		if (__machine__create_kernel_maps(machine, kernel) < 0) {
1884 			dso__put(kernel);
1885 			goto out_problem;
1886 		}
1887 
1888 		if (strstr(kernel->long_name, "vmlinux"))
1889 			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
1890 
1891 		if (machine__update_kernel_mmap(machine, xm->start, xm->end) < 0) {
1892 			dso__put(kernel);
1893 			goto out_problem;
1894 		}
1895 
1896 		if (build_id__is_defined(bid))
1897 			dso__set_build_id(kernel, bid);
1898 
1899 		/*
1900 		 * Avoid using a zero address (kptr_restrict) for the ref reloc
1901 		 * symbol. Effectively having zero here means that at record
1902 		 * time /proc/sys/kernel/kptr_restrict was non zero.
1903 		 */
1904 		if (xm->pgoff != 0) {
1905 			map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map,
1906 							symbol_name,
1907 							xm->pgoff);
1908 		}
1909 
1910 		if (machine__is_default_guest(machine)) {
1911 			/*
1912 			 * preload dso of guest kernel and modules
1913 			 */
1914 			dso__load(kernel, machine__kernel_map(machine));
1915 		}
1916 		dso__put(kernel);
1917 	} else if (perf_event__is_extra_kernel_mmap(machine, xm)) {
1918 		return machine__process_extra_kernel_map(machine, xm);
1919 	}
1920 	return 0;
1921 out_problem:
1922 	return -1;
1923 }
1924 
1925 int machine__process_mmap2_event(struct machine *machine,
1926 				 union perf_event *event,
1927 				 struct perf_sample *sample)
1928 {
1929 	struct thread *thread;
1930 	struct map *map;
1931 	struct dso_id dso_id = {
1932 		.maj = event->mmap2.maj,
1933 		.min = event->mmap2.min,
1934 		.ino = event->mmap2.ino,
1935 		.ino_generation = event->mmap2.ino_generation,
1936 	};
1937 	struct build_id __bid, *bid = NULL;
1938 	int ret = 0;
1939 
1940 	if (dump_trace)
1941 		perf_event__fprintf_mmap2(event, stdout);
1942 
1943 	if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
1944 		bid = &__bid;
1945 		build_id__init(bid, event->mmap2.build_id, event->mmap2.build_id_size);
1946 	}
1947 
1948 	if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
1949 	    sample->cpumode == PERF_RECORD_MISC_KERNEL) {
1950 		struct extra_kernel_map xm = {
1951 			.start = event->mmap2.start,
1952 			.end   = event->mmap2.start + event->mmap2.len,
1953 			.pgoff = event->mmap2.pgoff,
1954 		};
1955 
1956 		strlcpy(xm.name, event->mmap2.filename, KMAP_NAME_LEN);
1957 		ret = machine__process_kernel_mmap_event(machine, &xm, bid);
1958 		if (ret < 0)
1959 			goto out_problem;
1960 		return 0;
1961 	}
1962 
1963 	thread = machine__findnew_thread(machine, event->mmap2.pid,
1964 					event->mmap2.tid);
1965 	if (thread == NULL)
1966 		goto out_problem;
1967 
1968 	map = map__new(machine, event->mmap2.start,
1969 			event->mmap2.len, event->mmap2.pgoff,
1970 			&dso_id, event->mmap2.prot,
1971 			event->mmap2.flags, bid,
1972 			event->mmap2.filename, thread);
1973 
1974 	if (map == NULL)
1975 		goto out_problem_map;
1976 
1977 	ret = thread__insert_map(thread, map);
1978 	if (ret)
1979 		goto out_problem_insert;
1980 
1981 	thread__put(thread);
1982 	map__put(map);
1983 	return 0;
1984 
1985 out_problem_insert:
1986 	map__put(map);
1987 out_problem_map:
1988 	thread__put(thread);
1989 out_problem:
1990 	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
1991 	return 0;
1992 }
1993 
1994 int machine__process_mmap_event(struct machine *machine, union perf_event *event,
1995 				struct perf_sample *sample)
1996 {
1997 	struct thread *thread;
1998 	struct map *map;
1999 	u32 prot = 0;
2000 	int ret = 0;
2001 
2002 	if (dump_trace)
2003 		perf_event__fprintf_mmap(event, stdout);
2004 
2005 	if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
2006 	    sample->cpumode == PERF_RECORD_MISC_KERNEL) {
2007 		struct extra_kernel_map xm = {
2008 			.start = event->mmap.start,
2009 			.end   = event->mmap.start + event->mmap.len,
2010 			.pgoff = event->mmap.pgoff,
2011 		};
2012 
2013 		strlcpy(xm.name, event->mmap.filename, KMAP_NAME_LEN);
2014 		ret = machine__process_kernel_mmap_event(machine, &xm, NULL);
2015 		if (ret < 0)
2016 			goto out_problem;
2017 		return 0;
2018 	}
2019 
2020 	thread = machine__findnew_thread(machine, event->mmap.pid,
2021 					 event->mmap.tid);
2022 	if (thread == NULL)
2023 		goto out_problem;
2024 
2025 	if (!(event->header.misc & PERF_RECORD_MISC_MMAP_DATA))
2026 		prot = PROT_EXEC;
2027 
2028 	map = map__new(machine, event->mmap.start,
2029 			event->mmap.len, event->mmap.pgoff,
2030 			NULL, prot, 0, NULL, event->mmap.filename, thread);
2031 
2032 	if (map == NULL)
2033 		goto out_problem_map;
2034 
2035 	ret = thread__insert_map(thread, map);
2036 	if (ret)
2037 		goto out_problem_insert;
2038 
2039 	thread__put(thread);
2040 	map__put(map);
2041 	return 0;
2042 
2043 out_problem_insert:
2044 	map__put(map);
2045 out_problem_map:
2046 	thread__put(thread);
2047 out_problem:
2048 	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
2049 	return 0;
2050 }
2051 
2052 static void __machine__remove_thread(struct machine *machine, struct thread_rb_node *nd,
2053 				     struct thread *th, bool lock)
2054 {
2055 	struct threads *threads = machine__threads(machine, thread__tid(th));
2056 
2057 	if (!nd)
2058 		nd = thread_rb_node__find(th, &threads->entries.rb_root);
2059 
2060 	if (threads->last_match && RC_CHK_EQUAL(threads->last_match, th))
2061 		threads__set_last_match(threads, NULL);
2062 
2063 	if (lock)
2064 		down_write(&threads->lock);
2065 
2066 	BUG_ON(refcount_read(thread__refcnt(th)) == 0);
2067 
2068 	thread__put(nd->thread);
2069 	rb_erase_cached(&nd->rb_node, &threads->entries);
2070 	RB_CLEAR_NODE(&nd->rb_node);
2071 	--threads->nr;
2072 
2073 	free(nd);
2074 
2075 	if (lock)
2076 		up_write(&threads->lock);
2077 }
2078 
2079 void machine__remove_thread(struct machine *machine, struct thread *th)
2080 {
2081 	return __machine__remove_thread(machine, NULL, th, true);
2082 }
2083 
2084 int machine__process_fork_event(struct machine *machine, union perf_event *event,
2085 				struct perf_sample *sample)
2086 {
2087 	struct thread *thread = machine__find_thread(machine,
2088 						     event->fork.pid,
2089 						     event->fork.tid);
2090 	struct thread *parent = machine__findnew_thread(machine,
2091 							event->fork.ppid,
2092 							event->fork.ptid);
2093 	bool do_maps_clone = true;
2094 	int err = 0;
2095 
2096 	if (dump_trace)
2097 		perf_event__fprintf_task(event, stdout);
2098 
2099 	/*
2100 	 * There may be an existing thread that is not actually the parent,
2101 	 * either because we are processing events out of order, or because the
2102 	 * (fork) event that would have removed the thread was lost. Assume the
2103 	 * latter case and continue on as best we can.
2104 	 */
2105 	if (thread__pid(parent) != (pid_t)event->fork.ppid) {
2106 		dump_printf("removing erroneous parent thread %d/%d\n",
2107 			    thread__pid(parent), thread__tid(parent));
2108 		machine__remove_thread(machine, parent);
2109 		thread__put(parent);
2110 		parent = machine__findnew_thread(machine, event->fork.ppid,
2111 						 event->fork.ptid);
2112 	}
2113 
2114 	/* if a thread currently exists for the thread id remove it */
2115 	if (thread != NULL) {
2116 		machine__remove_thread(machine, thread);
2117 		thread__put(thread);
2118 	}
2119 
2120 	thread = machine__findnew_thread(machine, event->fork.pid,
2121 					 event->fork.tid);
2122 	/*
2123 	 * When synthesizing FORK events, we are trying to create thread
2124 	 * objects for the already running tasks on the machine.
2125 	 *
2126 	 * Normally, for a kernel FORK event, we want to clone the parent's
2127 	 * maps because that is what the kernel just did.
2128 	 *
2129 	 * But when synthesizing, this should not be done.  If we do, we end up
2130 	 * with overlapping maps as we process the synthesized MMAP2 events that
2131 	 * get delivered shortly thereafter.
2132 	 *
2133 	 * Use the FORK event misc flags in an internal way to signal this
2134 	 * situation, so we can elide the map clone when appropriate.
2135 	 */
2136 	if (event->fork.header.misc & PERF_RECORD_MISC_FORK_EXEC)
2137 		do_maps_clone = false;
2138 
2139 	if (thread == NULL || parent == NULL ||
2140 	    thread__fork(thread, parent, sample->time, do_maps_clone) < 0) {
2141 		dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
2142 		err = -1;
2143 	}
2144 	thread__put(thread);
2145 	thread__put(parent);
2146 
2147 	return err;
2148 }
2149 
2150 int machine__process_exit_event(struct machine *machine, union perf_event *event,
2151 				struct perf_sample *sample __maybe_unused)
2152 {
2153 	struct thread *thread = machine__find_thread(machine,
2154 						     event->fork.pid,
2155 						     event->fork.tid);
2156 
2157 	if (dump_trace)
2158 		perf_event__fprintf_task(event, stdout);
2159 
2160 	if (thread != NULL)
2161 		thread__put(thread);
2162 
2163 	return 0;
2164 }
2165 
2166 int machine__process_event(struct machine *machine, union perf_event *event,
2167 			   struct perf_sample *sample)
2168 {
2169 	int ret;
2170 
2171 	switch (event->header.type) {
2172 	case PERF_RECORD_COMM:
2173 		ret = machine__process_comm_event(machine, event, sample); break;
2174 	case PERF_RECORD_MMAP:
2175 		ret = machine__process_mmap_event(machine, event, sample); break;
2176 	case PERF_RECORD_NAMESPACES:
2177 		ret = machine__process_namespaces_event(machine, event, sample); break;
2178 	case PERF_RECORD_CGROUP:
2179 		ret = machine__process_cgroup_event(machine, event, sample); break;
2180 	case PERF_RECORD_MMAP2:
2181 		ret = machine__process_mmap2_event(machine, event, sample); break;
2182 	case PERF_RECORD_FORK:
2183 		ret = machine__process_fork_event(machine, event, sample); break;
2184 	case PERF_RECORD_EXIT:
2185 		ret = machine__process_exit_event(machine, event, sample); break;
2186 	case PERF_RECORD_LOST:
2187 		ret = machine__process_lost_event(machine, event, sample); break;
2188 	case PERF_RECORD_AUX:
2189 		ret = machine__process_aux_event(machine, event); break;
2190 	case PERF_RECORD_ITRACE_START:
2191 		ret = machine__process_itrace_start_event(machine, event); break;
2192 	case PERF_RECORD_LOST_SAMPLES:
2193 		ret = machine__process_lost_samples_event(machine, event, sample); break;
2194 	case PERF_RECORD_SWITCH:
2195 	case PERF_RECORD_SWITCH_CPU_WIDE:
2196 		ret = machine__process_switch_event(machine, event); break;
2197 	case PERF_RECORD_KSYMBOL:
2198 		ret = machine__process_ksymbol(machine, event, sample); break;
2199 	case PERF_RECORD_BPF_EVENT:
2200 		ret = machine__process_bpf(machine, event, sample); break;
2201 	case PERF_RECORD_TEXT_POKE:
2202 		ret = machine__process_text_poke(machine, event, sample); break;
2203 	case PERF_RECORD_AUX_OUTPUT_HW_ID:
2204 		ret = machine__process_aux_output_hw_id_event(machine, event); break;
2205 	default:
2206 		ret = -1;
2207 		break;
2208 	}
2209 
2210 	return ret;
2211 }
2212 
2213 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
2214 {
2215 	return regexec(regex, sym->name, 0, NULL, 0) == 0;
2216 }
2217 
2218 static void ip__resolve_ams(struct thread *thread,
2219 			    struct addr_map_symbol *ams,
2220 			    u64 ip)
2221 {
2222 	struct addr_location al;
2223 
2224 	addr_location__init(&al);
2225 	/*
2226 	 * We cannot use the header.misc hint to determine whether a
2227 	 * branch stack address is user, kernel, guest, hypervisor.
2228 	 * Branches may straddle the kernel/user/hypervisor boundaries.
2229 	 * Thus, we have to try consecutively until we find a match
2230 	 * or else, the symbol is unknown
2231 	 */
2232 	thread__find_cpumode_addr_location(thread, ip, &al);
2233 
2234 	ams->addr = ip;
2235 	ams->al_addr = al.addr;
2236 	ams->al_level = al.level;
2237 	ams->ms.maps = maps__get(al.maps);
2238 	ams->ms.sym = al.sym;
2239 	ams->ms.map = map__get(al.map);
2240 	ams->phys_addr = 0;
2241 	ams->data_page_size = 0;
2242 	addr_location__exit(&al);
2243 }
2244 
2245 static void ip__resolve_data(struct thread *thread,
2246 			     u8 m, struct addr_map_symbol *ams,
2247 			     u64 addr, u64 phys_addr, u64 daddr_page_size)
2248 {
2249 	struct addr_location al;
2250 
2251 	addr_location__init(&al);
2252 
2253 	thread__find_symbol(thread, m, addr, &al);
2254 
2255 	ams->addr = addr;
2256 	ams->al_addr = al.addr;
2257 	ams->al_level = al.level;
2258 	ams->ms.maps = maps__get(al.maps);
2259 	ams->ms.sym = al.sym;
2260 	ams->ms.map = map__get(al.map);
2261 	ams->phys_addr = phys_addr;
2262 	ams->data_page_size = daddr_page_size;
2263 	addr_location__exit(&al);
2264 }
2265 
2266 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
2267 				     struct addr_location *al)
2268 {
2269 	struct mem_info *mi = mem_info__new();
2270 
2271 	if (!mi)
2272 		return NULL;
2273 
2274 	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
2275 	ip__resolve_data(al->thread, al->cpumode, &mi->daddr,
2276 			 sample->addr, sample->phys_addr,
2277 			 sample->data_page_size);
2278 	mi->data_src.val = sample->data_src;
2279 
2280 	return mi;
2281 }
2282 
2283 static char *callchain_srcline(struct map_symbol *ms, u64 ip)
2284 {
2285 	struct map *map = ms->map;
2286 	char *srcline = NULL;
2287 	struct dso *dso;
2288 
2289 	if (!map || callchain_param.key == CCKEY_FUNCTION)
2290 		return srcline;
2291 
2292 	dso = map__dso(map);
2293 	srcline = srcline__tree_find(&dso->srclines, ip);
2294 	if (!srcline) {
2295 		bool show_sym = false;
2296 		bool show_addr = callchain_param.key == CCKEY_ADDRESS;
2297 
2298 		srcline = get_srcline(dso, map__rip_2objdump(map, ip),
2299 				      ms->sym, show_sym, show_addr, ip);
2300 		srcline__tree_insert(&dso->srclines, ip, srcline);
2301 	}
2302 
2303 	return srcline;
2304 }
2305 
2306 struct iterations {
2307 	int nr_loop_iter;
2308 	u64 cycles;
2309 };
2310 
2311 static int add_callchain_ip(struct thread *thread,
2312 			    struct callchain_cursor *cursor,
2313 			    struct symbol **parent,
2314 			    struct addr_location *root_al,
2315 			    u8 *cpumode,
2316 			    u64 ip,
2317 			    bool branch,
2318 			    struct branch_flags *flags,
2319 			    struct iterations *iter,
2320 			    u64 branch_from)
2321 {
2322 	struct map_symbol ms = {};
2323 	struct addr_location al;
2324 	int nr_loop_iter = 0, err = 0;
2325 	u64 iter_cycles = 0;
2326 	const char *srcline = NULL;
2327 
2328 	addr_location__init(&al);
2329 	al.filtered = 0;
2330 	al.sym = NULL;
2331 	al.srcline = NULL;
2332 	if (!cpumode) {
2333 		thread__find_cpumode_addr_location(thread, ip, &al);
2334 	} else {
2335 		if (ip >= PERF_CONTEXT_MAX) {
2336 			switch (ip) {
2337 			case PERF_CONTEXT_HV:
2338 				*cpumode = PERF_RECORD_MISC_HYPERVISOR;
2339 				break;
2340 			case PERF_CONTEXT_KERNEL:
2341 				*cpumode = PERF_RECORD_MISC_KERNEL;
2342 				break;
2343 			case PERF_CONTEXT_USER:
2344 				*cpumode = PERF_RECORD_MISC_USER;
2345 				break;
2346 			default:
2347 				pr_debug("invalid callchain context: "
2348 					 "%"PRId64"\n", (s64) ip);
2349 				/*
2350 				 * It seems the callchain is corrupted.
2351 				 * Discard all.
2352 				 */
2353 				callchain_cursor_reset(cursor);
2354 				err = 1;
2355 				goto out;
2356 			}
2357 			goto out;
2358 		}
2359 		thread__find_symbol(thread, *cpumode, ip, &al);
2360 	}
2361 
2362 	if (al.sym != NULL) {
2363 		if (perf_hpp_list.parent && !*parent &&
2364 		    symbol__match_regex(al.sym, &parent_regex))
2365 			*parent = al.sym;
2366 		else if (have_ignore_callees && root_al &&
2367 		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
2368 			/* Treat this symbol as the root,
2369 			   forgetting its callees. */
2370 			addr_location__copy(root_al, &al);
2371 			callchain_cursor_reset(cursor);
2372 		}
2373 	}
2374 
2375 	if (symbol_conf.hide_unresolved && al.sym == NULL)
2376 		goto out;
2377 
2378 	if (iter) {
2379 		nr_loop_iter = iter->nr_loop_iter;
2380 		iter_cycles = iter->cycles;
2381 	}
2382 
2383 	ms.maps = maps__get(al.maps);
2384 	ms.map = map__get(al.map);
2385 	ms.sym = al.sym;
2386 	srcline = callchain_srcline(&ms, al.addr);
2387 	err = callchain_cursor_append(cursor, ip, &ms,
2388 				      branch, flags, nr_loop_iter,
2389 				      iter_cycles, branch_from, srcline);
2390 out:
2391 	addr_location__exit(&al);
2392 	map_symbol__exit(&ms);
2393 	return err;
2394 }
2395 
2396 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
2397 					   struct addr_location *al)
2398 {
2399 	unsigned int i;
2400 	const struct branch_stack *bs = sample->branch_stack;
2401 	struct branch_entry *entries = perf_sample__branch_entries(sample);
2402 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
2403 
2404 	if (!bi)
2405 		return NULL;
2406 
2407 	for (i = 0; i < bs->nr; i++) {
2408 		ip__resolve_ams(al->thread, &bi[i].to, entries[i].to);
2409 		ip__resolve_ams(al->thread, &bi[i].from, entries[i].from);
2410 		bi[i].flags = entries[i].flags;
2411 	}
2412 	return bi;
2413 }
2414 
2415 static void save_iterations(struct iterations *iter,
2416 			    struct branch_entry *be, int nr)
2417 {
2418 	int i;
2419 
2420 	iter->nr_loop_iter++;
2421 	iter->cycles = 0;
2422 
2423 	for (i = 0; i < nr; i++)
2424 		iter->cycles += be[i].flags.cycles;
2425 }
2426 
2427 #define CHASHSZ 127
2428 #define CHASHBITS 7
2429 #define NO_ENTRY 0xff
2430 
2431 #define PERF_MAX_BRANCH_DEPTH 127
2432 
2433 /* Remove loops. */
2434 static int remove_loops(struct branch_entry *l, int nr,
2435 			struct iterations *iter)
2436 {
2437 	int i, j, off;
2438 	unsigned char chash[CHASHSZ];
2439 
2440 	memset(chash, NO_ENTRY, sizeof(chash));
2441 
2442 	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
2443 
2444 	for (i = 0; i < nr; i++) {
2445 		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
2446 
2447 		/* no collision handling for now */
2448 		if (chash[h] == NO_ENTRY) {
2449 			chash[h] = i;
2450 		} else if (l[chash[h]].from == l[i].from) {
2451 			bool is_loop = true;
2452 			/* check if it is a real loop */
2453 			off = 0;
2454 			for (j = chash[h]; j < i && i + off < nr; j++, off++)
2455 				if (l[j].from != l[i + off].from) {
2456 					is_loop = false;
2457 					break;
2458 				}
2459 			if (is_loop) {
2460 				j = nr - (i + off);
2461 				if (j > 0) {
2462 					save_iterations(iter + i + off,
2463 						l + i, off);
2464 
2465 					memmove(iter + i, iter + i + off,
2466 						j * sizeof(*iter));
2467 
2468 					memmove(l + i, l + i + off,
2469 						j * sizeof(*l));
2470 				}
2471 
2472 				nr -= off;
2473 			}
2474 		}
2475 	}
2476 	return nr;
2477 }
2478 
2479 static int lbr_callchain_add_kernel_ip(struct thread *thread,
2480 				       struct callchain_cursor *cursor,
2481 				       struct perf_sample *sample,
2482 				       struct symbol **parent,
2483 				       struct addr_location *root_al,
2484 				       u64 branch_from,
2485 				       bool callee, int end)
2486 {
2487 	struct ip_callchain *chain = sample->callchain;
2488 	u8 cpumode = PERF_RECORD_MISC_USER;
2489 	int err, i;
2490 
2491 	if (callee) {
2492 		for (i = 0; i < end + 1; i++) {
2493 			err = add_callchain_ip(thread, cursor, parent,
2494 					       root_al, &cpumode, chain->ips[i],
2495 					       false, NULL, NULL, branch_from);
2496 			if (err)
2497 				return err;
2498 		}
2499 		return 0;
2500 	}
2501 
2502 	for (i = end; i >= 0; i--) {
2503 		err = add_callchain_ip(thread, cursor, parent,
2504 				       root_al, &cpumode, chain->ips[i],
2505 				       false, NULL, NULL, branch_from);
2506 		if (err)
2507 			return err;
2508 	}
2509 
2510 	return 0;
2511 }
2512 
2513 static void save_lbr_cursor_node(struct thread *thread,
2514 				 struct callchain_cursor *cursor,
2515 				 int idx)
2516 {
2517 	struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
2518 
2519 	if (!lbr_stitch)
2520 		return;
2521 
2522 	if (cursor->pos == cursor->nr) {
2523 		lbr_stitch->prev_lbr_cursor[idx].valid = false;
2524 		return;
2525 	}
2526 
2527 	if (!cursor->curr)
2528 		cursor->curr = cursor->first;
2529 	else
2530 		cursor->curr = cursor->curr->next;
2531 	memcpy(&lbr_stitch->prev_lbr_cursor[idx], cursor->curr,
2532 	       sizeof(struct callchain_cursor_node));
2533 
2534 	lbr_stitch->prev_lbr_cursor[idx].valid = true;
2535 	cursor->pos++;
2536 }
2537 
2538 static int lbr_callchain_add_lbr_ip(struct thread *thread,
2539 				    struct callchain_cursor *cursor,
2540 				    struct perf_sample *sample,
2541 				    struct symbol **parent,
2542 				    struct addr_location *root_al,
2543 				    u64 *branch_from,
2544 				    bool callee)
2545 {
2546 	struct branch_stack *lbr_stack = sample->branch_stack;
2547 	struct branch_entry *entries = perf_sample__branch_entries(sample);
2548 	u8 cpumode = PERF_RECORD_MISC_USER;
2549 	int lbr_nr = lbr_stack->nr;
2550 	struct branch_flags *flags;
2551 	int err, i;
2552 	u64 ip;
2553 
2554 	/*
2555 	 * The curr and pos are not used in writing session. They are cleared
2556 	 * in callchain_cursor_commit() when the writing session is closed.
2557 	 * Using curr and pos to track the current cursor node.
2558 	 */
2559 	if (thread__lbr_stitch(thread)) {
2560 		cursor->curr = NULL;
2561 		cursor->pos = cursor->nr;
2562 		if (cursor->nr) {
2563 			cursor->curr = cursor->first;
2564 			for (i = 0; i < (int)(cursor->nr - 1); i++)
2565 				cursor->curr = cursor->curr->next;
2566 		}
2567 	}
2568 
2569 	if (callee) {
2570 		/* Add LBR ip from first entries.to */
2571 		ip = entries[0].to;
2572 		flags = &entries[0].flags;
2573 		*branch_from = entries[0].from;
2574 		err = add_callchain_ip(thread, cursor, parent,
2575 				       root_al, &cpumode, ip,
2576 				       true, flags, NULL,
2577 				       *branch_from);
2578 		if (err)
2579 			return err;
2580 
2581 		/*
2582 		 * The number of cursor node increases.
2583 		 * Move the current cursor node.
2584 		 * But does not need to save current cursor node for entry 0.
2585 		 * It's impossible to stitch the whole LBRs of previous sample.
2586 		 */
2587 		if (thread__lbr_stitch(thread) && (cursor->pos != cursor->nr)) {
2588 			if (!cursor->curr)
2589 				cursor->curr = cursor->first;
2590 			else
2591 				cursor->curr = cursor->curr->next;
2592 			cursor->pos++;
2593 		}
2594 
2595 		/* Add LBR ip from entries.from one by one. */
2596 		for (i = 0; i < lbr_nr; i++) {
2597 			ip = entries[i].from;
2598 			flags = &entries[i].flags;
2599 			err = add_callchain_ip(thread, cursor, parent,
2600 					       root_al, &cpumode, ip,
2601 					       true, flags, NULL,
2602 					       *branch_from);
2603 			if (err)
2604 				return err;
2605 			save_lbr_cursor_node(thread, cursor, i);
2606 		}
2607 		return 0;
2608 	}
2609 
2610 	/* Add LBR ip from entries.from one by one. */
2611 	for (i = lbr_nr - 1; i >= 0; i--) {
2612 		ip = entries[i].from;
2613 		flags = &entries[i].flags;
2614 		err = add_callchain_ip(thread, cursor, parent,
2615 				       root_al, &cpumode, ip,
2616 				       true, flags, NULL,
2617 				       *branch_from);
2618 		if (err)
2619 			return err;
2620 		save_lbr_cursor_node(thread, cursor, i);
2621 	}
2622 
2623 	if (lbr_nr > 0) {
2624 		/* Add LBR ip from first entries.to */
2625 		ip = entries[0].to;
2626 		flags = &entries[0].flags;
2627 		*branch_from = entries[0].from;
2628 		err = add_callchain_ip(thread, cursor, parent,
2629 				root_al, &cpumode, ip,
2630 				true, flags, NULL,
2631 				*branch_from);
2632 		if (err)
2633 			return err;
2634 	}
2635 
2636 	return 0;
2637 }
2638 
2639 static int lbr_callchain_add_stitched_lbr_ip(struct thread *thread,
2640 					     struct callchain_cursor *cursor)
2641 {
2642 	struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
2643 	struct callchain_cursor_node *cnode;
2644 	struct stitch_list *stitch_node;
2645 	int err;
2646 
2647 	list_for_each_entry(stitch_node, &lbr_stitch->lists, node) {
2648 		cnode = &stitch_node->cursor;
2649 
2650 		err = callchain_cursor_append(cursor, cnode->ip,
2651 					      &cnode->ms,
2652 					      cnode->branch,
2653 					      &cnode->branch_flags,
2654 					      cnode->nr_loop_iter,
2655 					      cnode->iter_cycles,
2656 					      cnode->branch_from,
2657 					      cnode->srcline);
2658 		if (err)
2659 			return err;
2660 	}
2661 	return 0;
2662 }
2663 
2664 static struct stitch_list *get_stitch_node(struct thread *thread)
2665 {
2666 	struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
2667 	struct stitch_list *stitch_node;
2668 
2669 	if (!list_empty(&lbr_stitch->free_lists)) {
2670 		stitch_node = list_first_entry(&lbr_stitch->free_lists,
2671 					       struct stitch_list, node);
2672 		list_del(&stitch_node->node);
2673 
2674 		return stitch_node;
2675 	}
2676 
2677 	return malloc(sizeof(struct stitch_list));
2678 }
2679 
2680 static bool has_stitched_lbr(struct thread *thread,
2681 			     struct perf_sample *cur,
2682 			     struct perf_sample *prev,
2683 			     unsigned int max_lbr,
2684 			     bool callee)
2685 {
2686 	struct branch_stack *cur_stack = cur->branch_stack;
2687 	struct branch_entry *cur_entries = perf_sample__branch_entries(cur);
2688 	struct branch_stack *prev_stack = prev->branch_stack;
2689 	struct branch_entry *prev_entries = perf_sample__branch_entries(prev);
2690 	struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
2691 	int i, j, nr_identical_branches = 0;
2692 	struct stitch_list *stitch_node;
2693 	u64 cur_base, distance;
2694 
2695 	if (!cur_stack || !prev_stack)
2696 		return false;
2697 
2698 	/* Find the physical index of the base-of-stack for current sample. */
2699 	cur_base = max_lbr - cur_stack->nr + cur_stack->hw_idx + 1;
2700 
2701 	distance = (prev_stack->hw_idx > cur_base) ? (prev_stack->hw_idx - cur_base) :
2702 						     (max_lbr + prev_stack->hw_idx - cur_base);
2703 	/* Previous sample has shorter stack. Nothing can be stitched. */
2704 	if (distance + 1 > prev_stack->nr)
2705 		return false;
2706 
2707 	/*
2708 	 * Check if there are identical LBRs between two samples.
2709 	 * Identical LBRs must have same from, to and flags values. Also,
2710 	 * they have to be saved in the same LBR registers (same physical
2711 	 * index).
2712 	 *
2713 	 * Starts from the base-of-stack of current sample.
2714 	 */
2715 	for (i = distance, j = cur_stack->nr - 1; (i >= 0) && (j >= 0); i--, j--) {
2716 		if ((prev_entries[i].from != cur_entries[j].from) ||
2717 		    (prev_entries[i].to != cur_entries[j].to) ||
2718 		    (prev_entries[i].flags.value != cur_entries[j].flags.value))
2719 			break;
2720 		nr_identical_branches++;
2721 	}
2722 
2723 	if (!nr_identical_branches)
2724 		return false;
2725 
2726 	/*
2727 	 * Save the LBRs between the base-of-stack of previous sample
2728 	 * and the base-of-stack of current sample into lbr_stitch->lists.
2729 	 * These LBRs will be stitched later.
2730 	 */
2731 	for (i = prev_stack->nr - 1; i > (int)distance; i--) {
2732 
2733 		if (!lbr_stitch->prev_lbr_cursor[i].valid)
2734 			continue;
2735 
2736 		stitch_node = get_stitch_node(thread);
2737 		if (!stitch_node)
2738 			return false;
2739 
2740 		memcpy(&stitch_node->cursor, &lbr_stitch->prev_lbr_cursor[i],
2741 		       sizeof(struct callchain_cursor_node));
2742 
2743 		if (callee)
2744 			list_add(&stitch_node->node, &lbr_stitch->lists);
2745 		else
2746 			list_add_tail(&stitch_node->node, &lbr_stitch->lists);
2747 	}
2748 
2749 	return true;
2750 }
2751 
2752 static bool alloc_lbr_stitch(struct thread *thread, unsigned int max_lbr)
2753 {
2754 	if (thread__lbr_stitch(thread))
2755 		return true;
2756 
2757 	thread__set_lbr_stitch(thread, zalloc(sizeof(struct lbr_stitch)));
2758 	if (!thread__lbr_stitch(thread))
2759 		goto err;
2760 
2761 	thread__lbr_stitch(thread)->prev_lbr_cursor =
2762 		calloc(max_lbr + 1, sizeof(struct callchain_cursor_node));
2763 	if (!thread__lbr_stitch(thread)->prev_lbr_cursor)
2764 		goto free_lbr_stitch;
2765 
2766 	INIT_LIST_HEAD(&thread__lbr_stitch(thread)->lists);
2767 	INIT_LIST_HEAD(&thread__lbr_stitch(thread)->free_lists);
2768 
2769 	return true;
2770 
2771 free_lbr_stitch:
2772 	free(thread__lbr_stitch(thread));
2773 	thread__set_lbr_stitch(thread, NULL);
2774 err:
2775 	pr_warning("Failed to allocate space for stitched LBRs. Disable LBR stitch\n");
2776 	thread__set_lbr_stitch_enable(thread, false);
2777 	return false;
2778 }
2779 
2780 /*
2781  * Resolve LBR callstack chain sample
2782  * Return:
2783  * 1 on success get LBR callchain information
2784  * 0 no available LBR callchain information, should try fp
2785  * negative error code on other errors.
2786  */
2787 static int resolve_lbr_callchain_sample(struct thread *thread,
2788 					struct callchain_cursor *cursor,
2789 					struct perf_sample *sample,
2790 					struct symbol **parent,
2791 					struct addr_location *root_al,
2792 					int max_stack,
2793 					unsigned int max_lbr)
2794 {
2795 	bool callee = (callchain_param.order == ORDER_CALLEE);
2796 	struct ip_callchain *chain = sample->callchain;
2797 	int chain_nr = min(max_stack, (int)chain->nr), i;
2798 	struct lbr_stitch *lbr_stitch;
2799 	bool stitched_lbr = false;
2800 	u64 branch_from = 0;
2801 	int err;
2802 
2803 	for (i = 0; i < chain_nr; i++) {
2804 		if (chain->ips[i] == PERF_CONTEXT_USER)
2805 			break;
2806 	}
2807 
2808 	/* LBR only affects the user callchain */
2809 	if (i == chain_nr)
2810 		return 0;
2811 
2812 	if (thread__lbr_stitch_enable(thread) && !sample->no_hw_idx &&
2813 	    (max_lbr > 0) && alloc_lbr_stitch(thread, max_lbr)) {
2814 		lbr_stitch = thread__lbr_stitch(thread);
2815 
2816 		stitched_lbr = has_stitched_lbr(thread, sample,
2817 						&lbr_stitch->prev_sample,
2818 						max_lbr, callee);
2819 
2820 		if (!stitched_lbr && !list_empty(&lbr_stitch->lists)) {
2821 			list_replace_init(&lbr_stitch->lists,
2822 					  &lbr_stitch->free_lists);
2823 		}
2824 		memcpy(&lbr_stitch->prev_sample, sample, sizeof(*sample));
2825 	}
2826 
2827 	if (callee) {
2828 		/* Add kernel ip */
2829 		err = lbr_callchain_add_kernel_ip(thread, cursor, sample,
2830 						  parent, root_al, branch_from,
2831 						  true, i);
2832 		if (err)
2833 			goto error;
2834 
2835 		err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
2836 					       root_al, &branch_from, true);
2837 		if (err)
2838 			goto error;
2839 
2840 		if (stitched_lbr) {
2841 			err = lbr_callchain_add_stitched_lbr_ip(thread, cursor);
2842 			if (err)
2843 				goto error;
2844 		}
2845 
2846 	} else {
2847 		if (stitched_lbr) {
2848 			err = lbr_callchain_add_stitched_lbr_ip(thread, cursor);
2849 			if (err)
2850 				goto error;
2851 		}
2852 		err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
2853 					       root_al, &branch_from, false);
2854 		if (err)
2855 			goto error;
2856 
2857 		/* Add kernel ip */
2858 		err = lbr_callchain_add_kernel_ip(thread, cursor, sample,
2859 						  parent, root_al, branch_from,
2860 						  false, i);
2861 		if (err)
2862 			goto error;
2863 	}
2864 	return 1;
2865 
2866 error:
2867 	return (err < 0) ? err : 0;
2868 }
2869 
2870 static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
2871 			     struct callchain_cursor *cursor,
2872 			     struct symbol **parent,
2873 			     struct addr_location *root_al,
2874 			     u8 *cpumode, int ent)
2875 {
2876 	int err = 0;
2877 
2878 	while (--ent >= 0) {
2879 		u64 ip = chain->ips[ent];
2880 
2881 		if (ip >= PERF_CONTEXT_MAX) {
2882 			err = add_callchain_ip(thread, cursor, parent,
2883 					       root_al, cpumode, ip,
2884 					       false, NULL, NULL, 0);
2885 			break;
2886 		}
2887 	}
2888 	return err;
2889 }
2890 
2891 static u64 get_leaf_frame_caller(struct perf_sample *sample,
2892 		struct thread *thread, int usr_idx)
2893 {
2894 	if (machine__normalized_is(maps__machine(thread__maps(thread)), "arm64"))
2895 		return get_leaf_frame_caller_aarch64(sample, thread, usr_idx);
2896 	else
2897 		return 0;
2898 }
2899 
2900 static int thread__resolve_callchain_sample(struct thread *thread,
2901 					    struct callchain_cursor *cursor,
2902 					    struct evsel *evsel,
2903 					    struct perf_sample *sample,
2904 					    struct symbol **parent,
2905 					    struct addr_location *root_al,
2906 					    int max_stack)
2907 {
2908 	struct branch_stack *branch = sample->branch_stack;
2909 	struct branch_entry *entries = perf_sample__branch_entries(sample);
2910 	struct ip_callchain *chain = sample->callchain;
2911 	int chain_nr = 0;
2912 	u8 cpumode = PERF_RECORD_MISC_USER;
2913 	int i, j, err, nr_entries, usr_idx;
2914 	int skip_idx = -1;
2915 	int first_call = 0;
2916 	u64 leaf_frame_caller;
2917 
2918 	if (chain)
2919 		chain_nr = chain->nr;
2920 
2921 	if (evsel__has_branch_callstack(evsel)) {
2922 		struct perf_env *env = evsel__env(evsel);
2923 
2924 		err = resolve_lbr_callchain_sample(thread, cursor, sample, parent,
2925 						   root_al, max_stack,
2926 						   !env ? 0 : env->max_branches);
2927 		if (err)
2928 			return (err < 0) ? err : 0;
2929 	}
2930 
2931 	/*
2932 	 * Based on DWARF debug information, some architectures skip
2933 	 * a callchain entry saved by the kernel.
2934 	 */
2935 	skip_idx = arch_skip_callchain_idx(thread, chain);
2936 
2937 	/*
2938 	 * Add branches to call stack for easier browsing. This gives
2939 	 * more context for a sample than just the callers.
2940 	 *
2941 	 * This uses individual histograms of paths compared to the
2942 	 * aggregated histograms the normal LBR mode uses.
2943 	 *
2944 	 * Limitations for now:
2945 	 * - No extra filters
2946 	 * - No annotations (should annotate somehow)
2947 	 */
2948 
2949 	if (branch && callchain_param.branch_callstack) {
2950 		int nr = min(max_stack, (int)branch->nr);
2951 		struct branch_entry be[nr];
2952 		struct iterations iter[nr];
2953 
2954 		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
2955 			pr_warning("corrupted branch chain. skipping...\n");
2956 			goto check_calls;
2957 		}
2958 
2959 		for (i = 0; i < nr; i++) {
2960 			if (callchain_param.order == ORDER_CALLEE) {
2961 				be[i] = entries[i];
2962 
2963 				if (chain == NULL)
2964 					continue;
2965 
2966 				/*
2967 				 * Check for overlap into the callchain.
2968 				 * The return address is one off compared to
2969 				 * the branch entry. To adjust for this
2970 				 * assume the calling instruction is not longer
2971 				 * than 8 bytes.
2972 				 */
2973 				if (i == skip_idx ||
2974 				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
2975 					first_call++;
2976 				else if (be[i].from < chain->ips[first_call] &&
2977 				    be[i].from >= chain->ips[first_call] - 8)
2978 					first_call++;
2979 			} else
2980 				be[i] = entries[branch->nr - i - 1];
2981 		}
2982 
2983 		memset(iter, 0, sizeof(struct iterations) * nr);
2984 		nr = remove_loops(be, nr, iter);
2985 
2986 		for (i = 0; i < nr; i++) {
2987 			err = add_callchain_ip(thread, cursor, parent,
2988 					       root_al,
2989 					       NULL, be[i].to,
2990 					       true, &be[i].flags,
2991 					       NULL, be[i].from);
2992 
2993 			if (!err)
2994 				err = add_callchain_ip(thread, cursor, parent, root_al,
2995 						       NULL, be[i].from,
2996 						       true, &be[i].flags,
2997 						       &iter[i], 0);
2998 			if (err == -EINVAL)
2999 				break;
3000 			if (err)
3001 				return err;
3002 		}
3003 
3004 		if (chain_nr == 0)
3005 			return 0;
3006 
3007 		chain_nr -= nr;
3008 	}
3009 
3010 check_calls:
3011 	if (chain && callchain_param.order != ORDER_CALLEE) {
3012 		err = find_prev_cpumode(chain, thread, cursor, parent, root_al,
3013 					&cpumode, chain->nr - first_call);
3014 		if (err)
3015 			return (err < 0) ? err : 0;
3016 	}
3017 	for (i = first_call, nr_entries = 0;
3018 	     i < chain_nr && nr_entries < max_stack; i++) {
3019 		u64 ip;
3020 
3021 		if (callchain_param.order == ORDER_CALLEE)
3022 			j = i;
3023 		else
3024 			j = chain->nr - i - 1;
3025 
3026 #ifdef HAVE_SKIP_CALLCHAIN_IDX
3027 		if (j == skip_idx)
3028 			continue;
3029 #endif
3030 		ip = chain->ips[j];
3031 		if (ip < PERF_CONTEXT_MAX)
3032                        ++nr_entries;
3033 		else if (callchain_param.order != ORDER_CALLEE) {
3034 			err = find_prev_cpumode(chain, thread, cursor, parent,
3035 						root_al, &cpumode, j);
3036 			if (err)
3037 				return (err < 0) ? err : 0;
3038 			continue;
3039 		}
3040 
3041 		/*
3042 		 * PERF_CONTEXT_USER allows us to locate where the user stack ends.
3043 		 * Depending on callchain_param.order and the position of PERF_CONTEXT_USER,
3044 		 * the index will be different in order to add the missing frame
3045 		 * at the right place.
3046 		 */
3047 
3048 		usr_idx = callchain_param.order == ORDER_CALLEE ? j-2 : j-1;
3049 
3050 		if (usr_idx >= 0 && chain->ips[usr_idx] == PERF_CONTEXT_USER) {
3051 
3052 			leaf_frame_caller = get_leaf_frame_caller(sample, thread, usr_idx);
3053 
3054 			/*
3055 			 * check if leaf_frame_Caller != ip to not add the same
3056 			 * value twice.
3057 			 */
3058 
3059 			if (leaf_frame_caller && leaf_frame_caller != ip) {
3060 
3061 				err = add_callchain_ip(thread, cursor, parent,
3062 					       root_al, &cpumode, leaf_frame_caller,
3063 					       false, NULL, NULL, 0);
3064 				if (err)
3065 					return (err < 0) ? err : 0;
3066 			}
3067 		}
3068 
3069 		err = add_callchain_ip(thread, cursor, parent,
3070 				       root_al, &cpumode, ip,
3071 				       false, NULL, NULL, 0);
3072 
3073 		if (err)
3074 			return (err < 0) ? err : 0;
3075 	}
3076 
3077 	return 0;
3078 }
3079 
3080 static int append_inlines(struct callchain_cursor *cursor, struct map_symbol *ms, u64 ip)
3081 {
3082 	struct symbol *sym = ms->sym;
3083 	struct map *map = ms->map;
3084 	struct inline_node *inline_node;
3085 	struct inline_list *ilist;
3086 	struct dso *dso;
3087 	u64 addr;
3088 	int ret = 1;
3089 	struct map_symbol ilist_ms;
3090 
3091 	if (!symbol_conf.inline_name || !map || !sym)
3092 		return ret;
3093 
3094 	addr = map__dso_map_ip(map, ip);
3095 	addr = map__rip_2objdump(map, addr);
3096 	dso = map__dso(map);
3097 
3098 	inline_node = inlines__tree_find(&dso->inlined_nodes, addr);
3099 	if (!inline_node) {
3100 		inline_node = dso__parse_addr_inlines(dso, addr, sym);
3101 		if (!inline_node)
3102 			return ret;
3103 		inlines__tree_insert(&dso->inlined_nodes, inline_node);
3104 	}
3105 
3106 	ilist_ms = (struct map_symbol) {
3107 		.maps = maps__get(ms->maps),
3108 		.map = map__get(map),
3109 	};
3110 	list_for_each_entry(ilist, &inline_node->val, list) {
3111 		ilist_ms.sym = ilist->symbol;
3112 		ret = callchain_cursor_append(cursor, ip, &ilist_ms, false,
3113 					      NULL, 0, 0, 0, ilist->srcline);
3114 
3115 		if (ret != 0)
3116 			return ret;
3117 	}
3118 	map_symbol__exit(&ilist_ms);
3119 
3120 	return ret;
3121 }
3122 
3123 static int unwind_entry(struct unwind_entry *entry, void *arg)
3124 {
3125 	struct callchain_cursor *cursor = arg;
3126 	const char *srcline = NULL;
3127 	u64 addr = entry->ip;
3128 
3129 	if (symbol_conf.hide_unresolved && entry->ms.sym == NULL)
3130 		return 0;
3131 
3132 	if (append_inlines(cursor, &entry->ms, entry->ip) == 0)
3133 		return 0;
3134 
3135 	/*
3136 	 * Convert entry->ip from a virtual address to an offset in
3137 	 * its corresponding binary.
3138 	 */
3139 	if (entry->ms.map)
3140 		addr = map__dso_map_ip(entry->ms.map, entry->ip);
3141 
3142 	srcline = callchain_srcline(&entry->ms, addr);
3143 	return callchain_cursor_append(cursor, entry->ip, &entry->ms,
3144 				       false, NULL, 0, 0, 0, srcline);
3145 }
3146 
3147 static int thread__resolve_callchain_unwind(struct thread *thread,
3148 					    struct callchain_cursor *cursor,
3149 					    struct evsel *evsel,
3150 					    struct perf_sample *sample,
3151 					    int max_stack)
3152 {
3153 	/* Can we do dwarf post unwind? */
3154 	if (!((evsel->core.attr.sample_type & PERF_SAMPLE_REGS_USER) &&
3155 	      (evsel->core.attr.sample_type & PERF_SAMPLE_STACK_USER)))
3156 		return 0;
3157 
3158 	/* Bail out if nothing was captured. */
3159 	if ((!sample->user_regs.regs) ||
3160 	    (!sample->user_stack.size))
3161 		return 0;
3162 
3163 	return unwind__get_entries(unwind_entry, cursor,
3164 				   thread, sample, max_stack, false);
3165 }
3166 
3167 int thread__resolve_callchain(struct thread *thread,
3168 			      struct callchain_cursor *cursor,
3169 			      struct evsel *evsel,
3170 			      struct perf_sample *sample,
3171 			      struct symbol **parent,
3172 			      struct addr_location *root_al,
3173 			      int max_stack)
3174 {
3175 	int ret = 0;
3176 
3177 	if (cursor == NULL)
3178 		return -ENOMEM;
3179 
3180 	callchain_cursor_reset(cursor);
3181 
3182 	if (callchain_param.order == ORDER_CALLEE) {
3183 		ret = thread__resolve_callchain_sample(thread, cursor,
3184 						       evsel, sample,
3185 						       parent, root_al,
3186 						       max_stack);
3187 		if (ret)
3188 			return ret;
3189 		ret = thread__resolve_callchain_unwind(thread, cursor,
3190 						       evsel, sample,
3191 						       max_stack);
3192 	} else {
3193 		ret = thread__resolve_callchain_unwind(thread, cursor,
3194 						       evsel, sample,
3195 						       max_stack);
3196 		if (ret)
3197 			return ret;
3198 		ret = thread__resolve_callchain_sample(thread, cursor,
3199 						       evsel, sample,
3200 						       parent, root_al,
3201 						       max_stack);
3202 	}
3203 
3204 	return ret;
3205 }
3206 
3207 int machine__for_each_thread(struct machine *machine,
3208 			     int (*fn)(struct thread *thread, void *p),
3209 			     void *priv)
3210 {
3211 	struct threads *threads;
3212 	struct rb_node *nd;
3213 	int rc = 0;
3214 	int i;
3215 
3216 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
3217 		threads = &machine->threads[i];
3218 		for (nd = rb_first_cached(&threads->entries); nd;
3219 		     nd = rb_next(nd)) {
3220 			struct thread_rb_node *trb = rb_entry(nd, struct thread_rb_node, rb_node);
3221 
3222 			rc = fn(trb->thread, priv);
3223 			if (rc != 0)
3224 				return rc;
3225 		}
3226 	}
3227 	return rc;
3228 }
3229 
3230 int machines__for_each_thread(struct machines *machines,
3231 			      int (*fn)(struct thread *thread, void *p),
3232 			      void *priv)
3233 {
3234 	struct rb_node *nd;
3235 	int rc = 0;
3236 
3237 	rc = machine__for_each_thread(&machines->host, fn, priv);
3238 	if (rc != 0)
3239 		return rc;
3240 
3241 	for (nd = rb_first_cached(&machines->guests); nd; nd = rb_next(nd)) {
3242 		struct machine *machine = rb_entry(nd, struct machine, rb_node);
3243 
3244 		rc = machine__for_each_thread(machine, fn, priv);
3245 		if (rc != 0)
3246 			return rc;
3247 	}
3248 	return rc;
3249 }
3250 
3251 pid_t machine__get_current_tid(struct machine *machine, int cpu)
3252 {
3253 	if (cpu < 0 || (size_t)cpu >= machine->current_tid_sz)
3254 		return -1;
3255 
3256 	return machine->current_tid[cpu];
3257 }
3258 
3259 int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
3260 			     pid_t tid)
3261 {
3262 	struct thread *thread;
3263 	const pid_t init_val = -1;
3264 
3265 	if (cpu < 0)
3266 		return -EINVAL;
3267 
3268 	if (realloc_array_as_needed(machine->current_tid,
3269 				    machine->current_tid_sz,
3270 				    (unsigned int)cpu,
3271 				    &init_val))
3272 		return -ENOMEM;
3273 
3274 	machine->current_tid[cpu] = tid;
3275 
3276 	thread = machine__findnew_thread(machine, pid, tid);
3277 	if (!thread)
3278 		return -ENOMEM;
3279 
3280 	thread__set_cpu(thread, cpu);
3281 	thread__put(thread);
3282 
3283 	return 0;
3284 }
3285 
3286 /*
3287  * Compares the raw arch string. N.B. see instead perf_env__arch() or
3288  * machine__normalized_is() if a normalized arch is needed.
3289  */
3290 bool machine__is(struct machine *machine, const char *arch)
3291 {
3292 	return machine && !strcmp(perf_env__raw_arch(machine->env), arch);
3293 }
3294 
3295 bool machine__normalized_is(struct machine *machine, const char *arch)
3296 {
3297 	return machine && !strcmp(perf_env__arch(machine->env), arch);
3298 }
3299 
3300 int machine__nr_cpus_avail(struct machine *machine)
3301 {
3302 	return machine ? perf_env__nr_cpus_avail(machine->env) : 0;
3303 }
3304 
3305 int machine__get_kernel_start(struct machine *machine)
3306 {
3307 	struct map *map = machine__kernel_map(machine);
3308 	int err = 0;
3309 
3310 	/*
3311 	 * The only addresses above 2^63 are kernel addresses of a 64-bit
3312 	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
3313 	 * all addresses including kernel addresses are less than 2^32.  In
3314 	 * that case (32-bit system), if the kernel mapping is unknown, all
3315 	 * addresses will be assumed to be in user space - see
3316 	 * machine__kernel_ip().
3317 	 */
3318 	machine->kernel_start = 1ULL << 63;
3319 	if (map) {
3320 		err = map__load(map);
3321 		/*
3322 		 * On x86_64, PTI entry trampolines are less than the
3323 		 * start of kernel text, but still above 2^63. So leave
3324 		 * kernel_start = 1ULL << 63 for x86_64.
3325 		 */
3326 		if (!err && !machine__is(machine, "x86_64"))
3327 			machine->kernel_start = map__start(map);
3328 	}
3329 	return err;
3330 }
3331 
3332 u8 machine__addr_cpumode(struct machine *machine, u8 cpumode, u64 addr)
3333 {
3334 	u8 addr_cpumode = cpumode;
3335 	bool kernel_ip;
3336 
3337 	if (!machine->single_address_space)
3338 		goto out;
3339 
3340 	kernel_ip = machine__kernel_ip(machine, addr);
3341 	switch (cpumode) {
3342 	case PERF_RECORD_MISC_KERNEL:
3343 	case PERF_RECORD_MISC_USER:
3344 		addr_cpumode = kernel_ip ? PERF_RECORD_MISC_KERNEL :
3345 					   PERF_RECORD_MISC_USER;
3346 		break;
3347 	case PERF_RECORD_MISC_GUEST_KERNEL:
3348 	case PERF_RECORD_MISC_GUEST_USER:
3349 		addr_cpumode = kernel_ip ? PERF_RECORD_MISC_GUEST_KERNEL :
3350 					   PERF_RECORD_MISC_GUEST_USER;
3351 		break;
3352 	default:
3353 		break;
3354 	}
3355 out:
3356 	return addr_cpumode;
3357 }
3358 
3359 struct dso *machine__findnew_dso_id(struct machine *machine, const char *filename, struct dso_id *id)
3360 {
3361 	return dsos__findnew_id(&machine->dsos, filename, id);
3362 }
3363 
3364 struct dso *machine__findnew_dso(struct machine *machine, const char *filename)
3365 {
3366 	return machine__findnew_dso_id(machine, filename, NULL);
3367 }
3368 
3369 char *machine__resolve_kernel_addr(void *vmachine, unsigned long long *addrp, char **modp)
3370 {
3371 	struct machine *machine = vmachine;
3372 	struct map *map;
3373 	struct symbol *sym = machine__find_kernel_symbol(machine, *addrp, &map);
3374 
3375 	if (sym == NULL)
3376 		return NULL;
3377 
3378 	*modp = __map__is_kmodule(map) ? (char *)map__dso(map)->short_name : NULL;
3379 	*addrp = map__unmap_ip(map, sym->start);
3380 	return sym->name;
3381 }
3382 
3383 int machine__for_each_dso(struct machine *machine, machine__dso_t fn, void *priv)
3384 {
3385 	struct dso *pos;
3386 	int err = 0;
3387 
3388 	list_for_each_entry(pos, &machine->dsos.head, node) {
3389 		if (fn(pos, machine, priv))
3390 			err = -1;
3391 	}
3392 	return err;
3393 }
3394 
3395 int machine__for_each_kernel_map(struct machine *machine, machine__map_t fn, void *priv)
3396 {
3397 	struct maps *maps = machine__kernel_maps(machine);
3398 	struct map_rb_node *pos;
3399 	int err = 0;
3400 
3401 	maps__for_each_entry(maps, pos) {
3402 		err = fn(pos->map, priv);
3403 		if (err != 0) {
3404 			break;
3405 		}
3406 	}
3407 	return err;
3408 }
3409 
3410 bool machine__is_lock_function(struct machine *machine, u64 addr)
3411 {
3412 	if (!machine->sched.text_start) {
3413 		struct map *kmap;
3414 		struct symbol *sym = machine__find_kernel_symbol_by_name(machine, "__sched_text_start", &kmap);
3415 
3416 		if (!sym) {
3417 			/* to avoid retry */
3418 			machine->sched.text_start = 1;
3419 			return false;
3420 		}
3421 
3422 		machine->sched.text_start = map__unmap_ip(kmap, sym->start);
3423 
3424 		/* should not fail from here */
3425 		sym = machine__find_kernel_symbol_by_name(machine, "__sched_text_end", &kmap);
3426 		machine->sched.text_end = map__unmap_ip(kmap, sym->start);
3427 
3428 		sym = machine__find_kernel_symbol_by_name(machine, "__lock_text_start", &kmap);
3429 		machine->lock.text_start = map__unmap_ip(kmap, sym->start);
3430 
3431 		sym = machine__find_kernel_symbol_by_name(machine, "__lock_text_end", &kmap);
3432 		machine->lock.text_end = map__unmap_ip(kmap, sym->start);
3433 	}
3434 
3435 	/* failed to get kernel symbols */
3436 	if (machine->sched.text_start == 1)
3437 		return false;
3438 
3439 	/* mutex and rwsem functions are in sched text section */
3440 	if (machine->sched.text_start <= addr && addr < machine->sched.text_end)
3441 		return true;
3442 
3443 	/* spinlock functions are in lock text section */
3444 	if (machine->lock.text_start <= addr && addr < machine->lock.text_end)
3445 		return true;
3446 
3447 	return false;
3448 }
3449