xref: /linux/tools/perf/util/symbol.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 #include <dirent.h>
2 #include <errno.h>
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <string.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <sys/param.h>
9 #include <fcntl.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 #include "annotate.h"
13 #include "build-id.h"
14 #include "util.h"
15 #include "debug.h"
16 #include "machine.h"
17 #include "symbol.h"
18 #include "strlist.h"
19 #include "intlist.h"
20 #include "header.h"
21 
22 #include <elf.h>
23 #include <limits.h>
24 #include <symbol/kallsyms.h>
25 #include <sys/utsname.h>
26 
27 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
28 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
29 static bool symbol__is_idle(const char *name);
30 
31 int vmlinux_path__nr_entries;
32 char **vmlinux_path;
33 
34 struct symbol_conf symbol_conf = {
35 	.use_modules		= true,
36 	.try_vmlinux_path	= true,
37 	.annotate_src		= true,
38 	.demangle		= true,
39 	.demangle_kernel	= false,
40 	.cumulate_callchain	= true,
41 	.show_hist_headers	= true,
42 	.symfs			= "",
43 	.event_group		= true,
44 };
45 
46 static enum dso_binary_type binary_type_symtab[] = {
47 	DSO_BINARY_TYPE__KALLSYMS,
48 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
49 	DSO_BINARY_TYPE__JAVA_JIT,
50 	DSO_BINARY_TYPE__DEBUGLINK,
51 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
52 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
53 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
54 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
55 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
56 	DSO_BINARY_TYPE__GUEST_KMODULE,
57 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
58 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
59 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
60 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
61 	DSO_BINARY_TYPE__NOT_FOUND,
62 };
63 
64 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
65 
66 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
67 {
68 	symbol_type = toupper(symbol_type);
69 
70 	switch (map_type) {
71 	case MAP__FUNCTION:
72 		return symbol_type == 'T' || symbol_type == 'W';
73 	case MAP__VARIABLE:
74 		return symbol_type == 'D';
75 	default:
76 		return false;
77 	}
78 }
79 
80 static int prefix_underscores_count(const char *str)
81 {
82 	const char *tail = str;
83 
84 	while (*tail == '_')
85 		tail++;
86 
87 	return tail - str;
88 }
89 
90 int __weak arch__choose_best_symbol(struct symbol *syma,
91 				    struct symbol *symb __maybe_unused)
92 {
93 	/* Avoid "SyS" kernel syscall aliases */
94 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
95 		return SYMBOL_B;
96 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
97 		return SYMBOL_B;
98 
99 	return SYMBOL_A;
100 }
101 
102 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
103 {
104 	s64 a;
105 	s64 b;
106 	size_t na, nb;
107 
108 	/* Prefer a symbol with non zero length */
109 	a = syma->end - syma->start;
110 	b = symb->end - symb->start;
111 	if ((b == 0) && (a > 0))
112 		return SYMBOL_A;
113 	else if ((a == 0) && (b > 0))
114 		return SYMBOL_B;
115 
116 	/* Prefer a non weak symbol over a weak one */
117 	a = syma->binding == STB_WEAK;
118 	b = symb->binding == STB_WEAK;
119 	if (b && !a)
120 		return SYMBOL_A;
121 	if (a && !b)
122 		return SYMBOL_B;
123 
124 	/* Prefer a global symbol over a non global one */
125 	a = syma->binding == STB_GLOBAL;
126 	b = symb->binding == STB_GLOBAL;
127 	if (a && !b)
128 		return SYMBOL_A;
129 	if (b && !a)
130 		return SYMBOL_B;
131 
132 	/* Prefer a symbol with less underscores */
133 	a = prefix_underscores_count(syma->name);
134 	b = prefix_underscores_count(symb->name);
135 	if (b > a)
136 		return SYMBOL_A;
137 	else if (a > b)
138 		return SYMBOL_B;
139 
140 	/* Choose the symbol with the longest name */
141 	na = strlen(syma->name);
142 	nb = strlen(symb->name);
143 	if (na > nb)
144 		return SYMBOL_A;
145 	else if (na < nb)
146 		return SYMBOL_B;
147 
148 	return arch__choose_best_symbol(syma, symb);
149 }
150 
151 void symbols__fixup_duplicate(struct rb_root *symbols)
152 {
153 	struct rb_node *nd;
154 	struct symbol *curr, *next;
155 
156 	if (symbol_conf.allow_aliases)
157 		return;
158 
159 	nd = rb_first(symbols);
160 
161 	while (nd) {
162 		curr = rb_entry(nd, struct symbol, rb_node);
163 again:
164 		nd = rb_next(&curr->rb_node);
165 		next = rb_entry(nd, struct symbol, rb_node);
166 
167 		if (!nd)
168 			break;
169 
170 		if (curr->start != next->start)
171 			continue;
172 
173 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
174 			rb_erase(&next->rb_node, symbols);
175 			symbol__delete(next);
176 			goto again;
177 		} else {
178 			nd = rb_next(&curr->rb_node);
179 			rb_erase(&curr->rb_node, symbols);
180 			symbol__delete(curr);
181 		}
182 	}
183 }
184 
185 void symbols__fixup_end(struct rb_root *symbols)
186 {
187 	struct rb_node *nd, *prevnd = rb_first(symbols);
188 	struct symbol *curr, *prev;
189 
190 	if (prevnd == NULL)
191 		return;
192 
193 	curr = rb_entry(prevnd, struct symbol, rb_node);
194 
195 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
196 		prev = curr;
197 		curr = rb_entry(nd, struct symbol, rb_node);
198 
199 		if (prev->end == prev->start && prev->end != curr->start)
200 			prev->end = curr->start;
201 	}
202 
203 	/* Last entry */
204 	if (curr->end == curr->start)
205 		curr->end = roundup(curr->start, 4096);
206 }
207 
208 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
209 {
210 	struct maps *maps = &mg->maps[type];
211 	struct map *next, *curr;
212 
213 	pthread_rwlock_wrlock(&maps->lock);
214 
215 	curr = maps__first(maps);
216 	if (curr == NULL)
217 		goto out_unlock;
218 
219 	for (next = map__next(curr); next; next = map__next(curr)) {
220 		curr->end = next->start;
221 		curr = next;
222 	}
223 
224 	/*
225 	 * We still haven't the actual symbols, so guess the
226 	 * last map final address.
227 	 */
228 	curr->end = ~0ULL;
229 
230 out_unlock:
231 	pthread_rwlock_unlock(&maps->lock);
232 }
233 
234 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
235 {
236 	size_t namelen = strlen(name) + 1;
237 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
238 					sizeof(*sym) + namelen));
239 	if (sym == NULL)
240 		return NULL;
241 
242 	if (symbol_conf.priv_size) {
243 		if (symbol_conf.init_annotation) {
244 			struct annotation *notes = (void *)sym;
245 			pthread_mutex_init(&notes->lock, NULL);
246 		}
247 		sym = ((void *)sym) + symbol_conf.priv_size;
248 	}
249 
250 	sym->start   = start;
251 	sym->end     = len ? start + len : start;
252 	sym->binding = binding;
253 	sym->namelen = namelen - 1;
254 
255 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
256 		  __func__, name, start, sym->end);
257 	memcpy(sym->name, name, namelen);
258 
259 	return sym;
260 }
261 
262 void symbol__delete(struct symbol *sym)
263 {
264 	free(((void *)sym) - symbol_conf.priv_size);
265 }
266 
267 void symbols__delete(struct rb_root *symbols)
268 {
269 	struct symbol *pos;
270 	struct rb_node *next = rb_first(symbols);
271 
272 	while (next) {
273 		pos = rb_entry(next, struct symbol, rb_node);
274 		next = rb_next(&pos->rb_node);
275 		rb_erase(&pos->rb_node, symbols);
276 		symbol__delete(pos);
277 	}
278 }
279 
280 void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel)
281 {
282 	struct rb_node **p = &symbols->rb_node;
283 	struct rb_node *parent = NULL;
284 	const u64 ip = sym->start;
285 	struct symbol *s;
286 
287 	if (kernel) {
288 		const char *name = sym->name;
289 		/*
290 		 * ppc64 uses function descriptors and appends a '.' to the
291 		 * start of every instruction address. Remove it.
292 		 */
293 		if (name[0] == '.')
294 			name++;
295 		sym->idle = symbol__is_idle(name);
296 	}
297 
298 	while (*p != NULL) {
299 		parent = *p;
300 		s = rb_entry(parent, struct symbol, rb_node);
301 		if (ip < s->start)
302 			p = &(*p)->rb_left;
303 		else
304 			p = &(*p)->rb_right;
305 	}
306 	rb_link_node(&sym->rb_node, parent, p);
307 	rb_insert_color(&sym->rb_node, symbols);
308 }
309 
310 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
311 {
312 	__symbols__insert(symbols, sym, false);
313 }
314 
315 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
316 {
317 	struct rb_node *n;
318 
319 	if (symbols == NULL)
320 		return NULL;
321 
322 	n = symbols->rb_node;
323 
324 	while (n) {
325 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
326 
327 		if (ip < s->start)
328 			n = n->rb_left;
329 		else if (ip > s->end || (ip == s->end && ip != s->start))
330 			n = n->rb_right;
331 		else
332 			return s;
333 	}
334 
335 	return NULL;
336 }
337 
338 static struct symbol *symbols__first(struct rb_root *symbols)
339 {
340 	struct rb_node *n = rb_first(symbols);
341 
342 	if (n)
343 		return rb_entry(n, struct symbol, rb_node);
344 
345 	return NULL;
346 }
347 
348 static struct symbol *symbols__last(struct rb_root *symbols)
349 {
350 	struct rb_node *n = rb_last(symbols);
351 
352 	if (n)
353 		return rb_entry(n, struct symbol, rb_node);
354 
355 	return NULL;
356 }
357 
358 static struct symbol *symbols__next(struct symbol *sym)
359 {
360 	struct rb_node *n = rb_next(&sym->rb_node);
361 
362 	if (n)
363 		return rb_entry(n, struct symbol, rb_node);
364 
365 	return NULL;
366 }
367 
368 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
369 {
370 	struct rb_node **p = &symbols->rb_node;
371 	struct rb_node *parent = NULL;
372 	struct symbol_name_rb_node *symn, *s;
373 
374 	symn = container_of(sym, struct symbol_name_rb_node, sym);
375 
376 	while (*p != NULL) {
377 		parent = *p;
378 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
379 		if (strcmp(sym->name, s->sym.name) < 0)
380 			p = &(*p)->rb_left;
381 		else
382 			p = &(*p)->rb_right;
383 	}
384 	rb_link_node(&symn->rb_node, parent, p);
385 	rb_insert_color(&symn->rb_node, symbols);
386 }
387 
388 static void symbols__sort_by_name(struct rb_root *symbols,
389 				  struct rb_root *source)
390 {
391 	struct rb_node *nd;
392 
393 	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
394 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
395 		symbols__insert_by_name(symbols, pos);
396 	}
397 }
398 
399 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
400 					    const char *name)
401 {
402 	struct rb_node *n;
403 	struct symbol_name_rb_node *s = NULL;
404 
405 	if (symbols == NULL)
406 		return NULL;
407 
408 	n = symbols->rb_node;
409 
410 	while (n) {
411 		int cmp;
412 
413 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
414 		cmp = arch__compare_symbol_names(name, s->sym.name);
415 
416 		if (cmp < 0)
417 			n = n->rb_left;
418 		else if (cmp > 0)
419 			n = n->rb_right;
420 		else
421 			break;
422 	}
423 
424 	if (n == NULL)
425 		return NULL;
426 
427 	/* return first symbol that has same name (if any) */
428 	for (n = rb_prev(n); n; n = rb_prev(n)) {
429 		struct symbol_name_rb_node *tmp;
430 
431 		tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
432 		if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
433 			break;
434 
435 		s = tmp;
436 	}
437 
438 	return &s->sym;
439 }
440 
441 void dso__reset_find_symbol_cache(struct dso *dso)
442 {
443 	enum map_type type;
444 
445 	for (type = MAP__FUNCTION; type <= MAP__VARIABLE; ++type) {
446 		dso->last_find_result[type].addr   = 0;
447 		dso->last_find_result[type].symbol = NULL;
448 	}
449 }
450 
451 void dso__insert_symbol(struct dso *dso, enum map_type type, struct symbol *sym)
452 {
453 	__symbols__insert(&dso->symbols[type], sym, dso->kernel);
454 
455 	/* update the symbol cache if necessary */
456 	if (dso->last_find_result[type].addr >= sym->start &&
457 	    (dso->last_find_result[type].addr < sym->end ||
458 	    sym->start == sym->end)) {
459 		dso->last_find_result[type].symbol = sym;
460 	}
461 }
462 
463 struct symbol *dso__find_symbol(struct dso *dso,
464 				enum map_type type, u64 addr)
465 {
466 	if (dso->last_find_result[type].addr != addr) {
467 		dso->last_find_result[type].addr   = addr;
468 		dso->last_find_result[type].symbol = symbols__find(&dso->symbols[type], addr);
469 	}
470 
471 	return dso->last_find_result[type].symbol;
472 }
473 
474 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
475 {
476 	return symbols__first(&dso->symbols[type]);
477 }
478 
479 struct symbol *dso__last_symbol(struct dso *dso, enum map_type type)
480 {
481 	return symbols__last(&dso->symbols[type]);
482 }
483 
484 struct symbol *dso__next_symbol(struct symbol *sym)
485 {
486 	return symbols__next(sym);
487 }
488 
489 struct symbol *symbol__next_by_name(struct symbol *sym)
490 {
491 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
492 	struct rb_node *n = rb_next(&s->rb_node);
493 
494 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
495 }
496 
497  /*
498   * Teturns first symbol that matched with @name.
499   */
500 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
501 					const char *name)
502 {
503 	return symbols__find_by_name(&dso->symbol_names[type], name);
504 }
505 
506 void dso__sort_by_name(struct dso *dso, enum map_type type)
507 {
508 	dso__set_sorted_by_name(dso, type);
509 	return symbols__sort_by_name(&dso->symbol_names[type],
510 				     &dso->symbols[type]);
511 }
512 
513 int modules__parse(const char *filename, void *arg,
514 		   int (*process_module)(void *arg, const char *name,
515 					 u64 start))
516 {
517 	char *line = NULL;
518 	size_t n;
519 	FILE *file;
520 	int err = 0;
521 
522 	file = fopen(filename, "r");
523 	if (file == NULL)
524 		return -1;
525 
526 	while (1) {
527 		char name[PATH_MAX];
528 		u64 start;
529 		char *sep;
530 		ssize_t line_len;
531 
532 		line_len = getline(&line, &n, file);
533 		if (line_len < 0) {
534 			if (feof(file))
535 				break;
536 			err = -1;
537 			goto out;
538 		}
539 
540 		if (!line) {
541 			err = -1;
542 			goto out;
543 		}
544 
545 		line[--line_len] = '\0'; /* \n */
546 
547 		sep = strrchr(line, 'x');
548 		if (sep == NULL)
549 			continue;
550 
551 		hex2u64(sep + 1, &start);
552 
553 		sep = strchr(line, ' ');
554 		if (sep == NULL)
555 			continue;
556 
557 		*sep = '\0';
558 
559 		scnprintf(name, sizeof(name), "[%s]", line);
560 
561 		err = process_module(arg, name, start);
562 		if (err)
563 			break;
564 	}
565 out:
566 	free(line);
567 	fclose(file);
568 	return err;
569 }
570 
571 struct process_kallsyms_args {
572 	struct map *map;
573 	struct dso *dso;
574 };
575 
576 /*
577  * These are symbols in the kernel image, so make sure that
578  * sym is from a kernel DSO.
579  */
580 static bool symbol__is_idle(const char *name)
581 {
582 	const char * const idle_symbols[] = {
583 		"cpu_idle",
584 		"cpu_startup_entry",
585 		"intel_idle",
586 		"default_idle",
587 		"native_safe_halt",
588 		"enter_idle",
589 		"exit_idle",
590 		"mwait_idle",
591 		"mwait_idle_with_hints",
592 		"poll_idle",
593 		"ppc64_runlatch_off",
594 		"pseries_dedicated_idle_sleep",
595 		NULL
596 	};
597 	int i;
598 
599 	for (i = 0; idle_symbols[i]; i++) {
600 		if (!strcmp(idle_symbols[i], name))
601 			return true;
602 	}
603 
604 	return false;
605 }
606 
607 static int map__process_kallsym_symbol(void *arg, const char *name,
608 				       char type, u64 start)
609 {
610 	struct symbol *sym;
611 	struct process_kallsyms_args *a = arg;
612 	struct rb_root *root = &a->dso->symbols[a->map->type];
613 
614 	if (!symbol_type__is_a(type, a->map->type))
615 		return 0;
616 
617 	/*
618 	 * module symbols are not sorted so we add all
619 	 * symbols, setting length to 0, and rely on
620 	 * symbols__fixup_end() to fix it up.
621 	 */
622 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), name);
623 	if (sym == NULL)
624 		return -ENOMEM;
625 	/*
626 	 * We will pass the symbols to the filter later, in
627 	 * map__split_kallsyms, when we have split the maps per module
628 	 */
629 	__symbols__insert(root, sym, !strchr(name, '['));
630 
631 	return 0;
632 }
633 
634 /*
635  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
636  * so that we can in the next step set the symbol ->end address and then
637  * call kernel_maps__split_kallsyms.
638  */
639 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
640 				  struct map *map)
641 {
642 	struct process_kallsyms_args args = { .map = map, .dso = dso, };
643 	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
644 }
645 
646 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map)
647 {
648 	struct map_groups *kmaps = map__kmaps(map);
649 	struct map *curr_map;
650 	struct symbol *pos;
651 	int count = 0;
652 	struct rb_root old_root = dso->symbols[map->type];
653 	struct rb_root *root = &dso->symbols[map->type];
654 	struct rb_node *next = rb_first(root);
655 
656 	if (!kmaps)
657 		return -1;
658 
659 	*root = RB_ROOT;
660 
661 	while (next) {
662 		char *module;
663 
664 		pos = rb_entry(next, struct symbol, rb_node);
665 		next = rb_next(&pos->rb_node);
666 
667 		rb_erase_init(&pos->rb_node, &old_root);
668 
669 		module = strchr(pos->name, '\t');
670 		if (module)
671 			*module = '\0';
672 
673 		curr_map = map_groups__find(kmaps, map->type, pos->start);
674 
675 		if (!curr_map) {
676 			symbol__delete(pos);
677 			continue;
678 		}
679 
680 		pos->start -= curr_map->start - curr_map->pgoff;
681 		if (pos->end)
682 			pos->end -= curr_map->start - curr_map->pgoff;
683 		symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
684 		++count;
685 	}
686 
687 	/* Symbols have been adjusted */
688 	dso->adjust_symbols = 1;
689 
690 	return count;
691 }
692 
693 /*
694  * Split the symbols into maps, making sure there are no overlaps, i.e. the
695  * kernel range is broken in several maps, named [kernel].N, as we don't have
696  * the original ELF section names vmlinux have.
697  */
698 static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta)
699 {
700 	struct map_groups *kmaps = map__kmaps(map);
701 	struct machine *machine;
702 	struct map *curr_map = map;
703 	struct symbol *pos;
704 	int count = 0, moved = 0;
705 	struct rb_root *root = &dso->symbols[map->type];
706 	struct rb_node *next = rb_first(root);
707 	int kernel_range = 0;
708 
709 	if (!kmaps)
710 		return -1;
711 
712 	machine = kmaps->machine;
713 
714 	while (next) {
715 		char *module;
716 
717 		pos = rb_entry(next, struct symbol, rb_node);
718 		next = rb_next(&pos->rb_node);
719 
720 		module = strchr(pos->name, '\t');
721 		if (module) {
722 			if (!symbol_conf.use_modules)
723 				goto discard_symbol;
724 
725 			*module++ = '\0';
726 
727 			if (strcmp(curr_map->dso->short_name, module)) {
728 				if (curr_map != map &&
729 				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
730 				    machine__is_default_guest(machine)) {
731 					/*
732 					 * We assume all symbols of a module are
733 					 * continuous in * kallsyms, so curr_map
734 					 * points to a module and all its
735 					 * symbols are in its kmap. Mark it as
736 					 * loaded.
737 					 */
738 					dso__set_loaded(curr_map->dso,
739 							curr_map->type);
740 				}
741 
742 				curr_map = map_groups__find_by_name(kmaps,
743 							map->type, module);
744 				if (curr_map == NULL) {
745 					pr_debug("%s/proc/{kallsyms,modules} "
746 					         "inconsistency while looking "
747 						 "for \"%s\" module!\n",
748 						 machine->root_dir, module);
749 					curr_map = map;
750 					goto discard_symbol;
751 				}
752 
753 				if (curr_map->dso->loaded &&
754 				    !machine__is_default_guest(machine))
755 					goto discard_symbol;
756 			}
757 			/*
758 			 * So that we look just like we get from .ko files,
759 			 * i.e. not prelinked, relative to map->start.
760 			 */
761 			pos->start = curr_map->map_ip(curr_map, pos->start);
762 			pos->end   = curr_map->map_ip(curr_map, pos->end);
763 		} else if (curr_map != map) {
764 			char dso_name[PATH_MAX];
765 			struct dso *ndso;
766 
767 			if (delta) {
768 				/* Kernel was relocated at boot time */
769 				pos->start -= delta;
770 				pos->end -= delta;
771 			}
772 
773 			if (count == 0) {
774 				curr_map = map;
775 				goto add_symbol;
776 			}
777 
778 			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
779 				snprintf(dso_name, sizeof(dso_name),
780 					"[guest.kernel].%d",
781 					kernel_range++);
782 			else
783 				snprintf(dso_name, sizeof(dso_name),
784 					"[kernel].%d",
785 					kernel_range++);
786 
787 			ndso = dso__new(dso_name);
788 			if (ndso == NULL)
789 				return -1;
790 
791 			ndso->kernel = dso->kernel;
792 
793 			curr_map = map__new2(pos->start, ndso, map->type);
794 			if (curr_map == NULL) {
795 				dso__put(ndso);
796 				return -1;
797 			}
798 
799 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
800 			map_groups__insert(kmaps, curr_map);
801 			++kernel_range;
802 		} else if (delta) {
803 			/* Kernel was relocated at boot time */
804 			pos->start -= delta;
805 			pos->end -= delta;
806 		}
807 add_symbol:
808 		if (curr_map != map) {
809 			rb_erase(&pos->rb_node, root);
810 			symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
811 			++moved;
812 		} else
813 			++count;
814 
815 		continue;
816 discard_symbol:
817 		rb_erase(&pos->rb_node, root);
818 		symbol__delete(pos);
819 	}
820 
821 	if (curr_map != map &&
822 	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
823 	    machine__is_default_guest(kmaps->machine)) {
824 		dso__set_loaded(curr_map->dso, curr_map->type);
825 	}
826 
827 	return count + moved;
828 }
829 
830 bool symbol__restricted_filename(const char *filename,
831 				 const char *restricted_filename)
832 {
833 	bool restricted = false;
834 
835 	if (symbol_conf.kptr_restrict) {
836 		char *r = realpath(filename, NULL);
837 
838 		if (r != NULL) {
839 			restricted = strcmp(r, restricted_filename) == 0;
840 			free(r);
841 			return restricted;
842 		}
843 	}
844 
845 	return restricted;
846 }
847 
848 struct module_info {
849 	struct rb_node rb_node;
850 	char *name;
851 	u64 start;
852 };
853 
854 static void add_module(struct module_info *mi, struct rb_root *modules)
855 {
856 	struct rb_node **p = &modules->rb_node;
857 	struct rb_node *parent = NULL;
858 	struct module_info *m;
859 
860 	while (*p != NULL) {
861 		parent = *p;
862 		m = rb_entry(parent, struct module_info, rb_node);
863 		if (strcmp(mi->name, m->name) < 0)
864 			p = &(*p)->rb_left;
865 		else
866 			p = &(*p)->rb_right;
867 	}
868 	rb_link_node(&mi->rb_node, parent, p);
869 	rb_insert_color(&mi->rb_node, modules);
870 }
871 
872 static void delete_modules(struct rb_root *modules)
873 {
874 	struct module_info *mi;
875 	struct rb_node *next = rb_first(modules);
876 
877 	while (next) {
878 		mi = rb_entry(next, struct module_info, rb_node);
879 		next = rb_next(&mi->rb_node);
880 		rb_erase(&mi->rb_node, modules);
881 		zfree(&mi->name);
882 		free(mi);
883 	}
884 }
885 
886 static struct module_info *find_module(const char *name,
887 				       struct rb_root *modules)
888 {
889 	struct rb_node *n = modules->rb_node;
890 
891 	while (n) {
892 		struct module_info *m;
893 		int cmp;
894 
895 		m = rb_entry(n, struct module_info, rb_node);
896 		cmp = strcmp(name, m->name);
897 		if (cmp < 0)
898 			n = n->rb_left;
899 		else if (cmp > 0)
900 			n = n->rb_right;
901 		else
902 			return m;
903 	}
904 
905 	return NULL;
906 }
907 
908 static int __read_proc_modules(void *arg, const char *name, u64 start)
909 {
910 	struct rb_root *modules = arg;
911 	struct module_info *mi;
912 
913 	mi = zalloc(sizeof(struct module_info));
914 	if (!mi)
915 		return -ENOMEM;
916 
917 	mi->name = strdup(name);
918 	mi->start = start;
919 
920 	if (!mi->name) {
921 		free(mi);
922 		return -ENOMEM;
923 	}
924 
925 	add_module(mi, modules);
926 
927 	return 0;
928 }
929 
930 static int read_proc_modules(const char *filename, struct rb_root *modules)
931 {
932 	if (symbol__restricted_filename(filename, "/proc/modules"))
933 		return -1;
934 
935 	if (modules__parse(filename, modules, __read_proc_modules)) {
936 		delete_modules(modules);
937 		return -1;
938 	}
939 
940 	return 0;
941 }
942 
943 int compare_proc_modules(const char *from, const char *to)
944 {
945 	struct rb_root from_modules = RB_ROOT;
946 	struct rb_root to_modules = RB_ROOT;
947 	struct rb_node *from_node, *to_node;
948 	struct module_info *from_m, *to_m;
949 	int ret = -1;
950 
951 	if (read_proc_modules(from, &from_modules))
952 		return -1;
953 
954 	if (read_proc_modules(to, &to_modules))
955 		goto out_delete_from;
956 
957 	from_node = rb_first(&from_modules);
958 	to_node = rb_first(&to_modules);
959 	while (from_node) {
960 		if (!to_node)
961 			break;
962 
963 		from_m = rb_entry(from_node, struct module_info, rb_node);
964 		to_m = rb_entry(to_node, struct module_info, rb_node);
965 
966 		if (from_m->start != to_m->start ||
967 		    strcmp(from_m->name, to_m->name))
968 			break;
969 
970 		from_node = rb_next(from_node);
971 		to_node = rb_next(to_node);
972 	}
973 
974 	if (!from_node && !to_node)
975 		ret = 0;
976 
977 	delete_modules(&to_modules);
978 out_delete_from:
979 	delete_modules(&from_modules);
980 
981 	return ret;
982 }
983 
984 static int do_validate_kcore_modules(const char *filename, struct map *map,
985 				  struct map_groups *kmaps)
986 {
987 	struct rb_root modules = RB_ROOT;
988 	struct map *old_map;
989 	int err;
990 
991 	err = read_proc_modules(filename, &modules);
992 	if (err)
993 		return err;
994 
995 	old_map = map_groups__first(kmaps, map->type);
996 	while (old_map) {
997 		struct map *next = map_groups__next(old_map);
998 		struct module_info *mi;
999 
1000 		if (old_map == map || old_map->start == map->start) {
1001 			/* The kernel map */
1002 			old_map = next;
1003 			continue;
1004 		}
1005 
1006 		/* Module must be in memory at the same address */
1007 		mi = find_module(old_map->dso->short_name, &modules);
1008 		if (!mi || mi->start != old_map->start) {
1009 			err = -EINVAL;
1010 			goto out;
1011 		}
1012 
1013 		old_map = next;
1014 	}
1015 out:
1016 	delete_modules(&modules);
1017 	return err;
1018 }
1019 
1020 /*
1021  * If kallsyms is referenced by name then we look for filename in the same
1022  * directory.
1023  */
1024 static bool filename_from_kallsyms_filename(char *filename,
1025 					    const char *base_name,
1026 					    const char *kallsyms_filename)
1027 {
1028 	char *name;
1029 
1030 	strcpy(filename, kallsyms_filename);
1031 	name = strrchr(filename, '/');
1032 	if (!name)
1033 		return false;
1034 
1035 	name += 1;
1036 
1037 	if (!strcmp(name, "kallsyms")) {
1038 		strcpy(name, base_name);
1039 		return true;
1040 	}
1041 
1042 	return false;
1043 }
1044 
1045 static int validate_kcore_modules(const char *kallsyms_filename,
1046 				  struct map *map)
1047 {
1048 	struct map_groups *kmaps = map__kmaps(map);
1049 	char modules_filename[PATH_MAX];
1050 
1051 	if (!kmaps)
1052 		return -EINVAL;
1053 
1054 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1055 					     kallsyms_filename))
1056 		return -EINVAL;
1057 
1058 	if (do_validate_kcore_modules(modules_filename, map, kmaps))
1059 		return -EINVAL;
1060 
1061 	return 0;
1062 }
1063 
1064 static int validate_kcore_addresses(const char *kallsyms_filename,
1065 				    struct map *map)
1066 {
1067 	struct kmap *kmap = map__kmap(map);
1068 
1069 	if (!kmap)
1070 		return -EINVAL;
1071 
1072 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1073 		u64 start;
1074 
1075 		start = kallsyms__get_function_start(kallsyms_filename,
1076 						     kmap->ref_reloc_sym->name);
1077 		if (start != kmap->ref_reloc_sym->addr)
1078 			return -EINVAL;
1079 	}
1080 
1081 	return validate_kcore_modules(kallsyms_filename, map);
1082 }
1083 
1084 struct kcore_mapfn_data {
1085 	struct dso *dso;
1086 	enum map_type type;
1087 	struct list_head maps;
1088 };
1089 
1090 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1091 {
1092 	struct kcore_mapfn_data *md = data;
1093 	struct map *map;
1094 
1095 	map = map__new2(start, md->dso, md->type);
1096 	if (map == NULL)
1097 		return -ENOMEM;
1098 
1099 	map->end = map->start + len;
1100 	map->pgoff = pgoff;
1101 
1102 	list_add(&map->node, &md->maps);
1103 
1104 	return 0;
1105 }
1106 
1107 static int dso__load_kcore(struct dso *dso, struct map *map,
1108 			   const char *kallsyms_filename)
1109 {
1110 	struct map_groups *kmaps = map__kmaps(map);
1111 	struct machine *machine;
1112 	struct kcore_mapfn_data md;
1113 	struct map *old_map, *new_map, *replacement_map = NULL;
1114 	bool is_64_bit;
1115 	int err, fd;
1116 	char kcore_filename[PATH_MAX];
1117 	struct symbol *sym;
1118 
1119 	if (!kmaps)
1120 		return -EINVAL;
1121 
1122 	machine = kmaps->machine;
1123 
1124 	/* This function requires that the map is the kernel map */
1125 	if (map != machine->vmlinux_maps[map->type])
1126 		return -EINVAL;
1127 
1128 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1129 					     kallsyms_filename))
1130 		return -EINVAL;
1131 
1132 	/* Modules and kernel must be present at their original addresses */
1133 	if (validate_kcore_addresses(kallsyms_filename, map))
1134 		return -EINVAL;
1135 
1136 	md.dso = dso;
1137 	md.type = map->type;
1138 	INIT_LIST_HEAD(&md.maps);
1139 
1140 	fd = open(kcore_filename, O_RDONLY);
1141 	if (fd < 0) {
1142 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1143 			 kcore_filename);
1144 		return -EINVAL;
1145 	}
1146 
1147 	/* Read new maps into temporary lists */
1148 	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1149 			      &is_64_bit);
1150 	if (err)
1151 		goto out_err;
1152 	dso->is_64_bit = is_64_bit;
1153 
1154 	if (list_empty(&md.maps)) {
1155 		err = -EINVAL;
1156 		goto out_err;
1157 	}
1158 
1159 	/* Remove old maps */
1160 	old_map = map_groups__first(kmaps, map->type);
1161 	while (old_map) {
1162 		struct map *next = map_groups__next(old_map);
1163 
1164 		if (old_map != map)
1165 			map_groups__remove(kmaps, old_map);
1166 		old_map = next;
1167 	}
1168 
1169 	/* Find the kernel map using the first symbol */
1170 	sym = dso__first_symbol(dso, map->type);
1171 	list_for_each_entry(new_map, &md.maps, node) {
1172 		if (sym && sym->start >= new_map->start &&
1173 		    sym->start < new_map->end) {
1174 			replacement_map = new_map;
1175 			break;
1176 		}
1177 	}
1178 
1179 	if (!replacement_map)
1180 		replacement_map = list_entry(md.maps.next, struct map, node);
1181 
1182 	/* Add new maps */
1183 	while (!list_empty(&md.maps)) {
1184 		new_map = list_entry(md.maps.next, struct map, node);
1185 		list_del_init(&new_map->node);
1186 		if (new_map == replacement_map) {
1187 			map->start	= new_map->start;
1188 			map->end	= new_map->end;
1189 			map->pgoff	= new_map->pgoff;
1190 			map->map_ip	= new_map->map_ip;
1191 			map->unmap_ip	= new_map->unmap_ip;
1192 			/* Ensure maps are correctly ordered */
1193 			map__get(map);
1194 			map_groups__remove(kmaps, map);
1195 			map_groups__insert(kmaps, map);
1196 			map__put(map);
1197 		} else {
1198 			map_groups__insert(kmaps, new_map);
1199 		}
1200 
1201 		map__put(new_map);
1202 	}
1203 
1204 	/*
1205 	 * Set the data type and long name so that kcore can be read via
1206 	 * dso__data_read_addr().
1207 	 */
1208 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1209 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1210 	else
1211 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1212 	dso__set_long_name(dso, strdup(kcore_filename), true);
1213 
1214 	close(fd);
1215 
1216 	if (map->type == MAP__FUNCTION)
1217 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1218 	else
1219 		pr_debug("Using %s for kernel data\n", kcore_filename);
1220 
1221 	return 0;
1222 
1223 out_err:
1224 	while (!list_empty(&md.maps)) {
1225 		map = list_entry(md.maps.next, struct map, node);
1226 		list_del_init(&map->node);
1227 		map__put(map);
1228 	}
1229 	close(fd);
1230 	return -EINVAL;
1231 }
1232 
1233 /*
1234  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1235  * delta based on the relocation reference symbol.
1236  */
1237 static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
1238 {
1239 	struct kmap *kmap = map__kmap(map);
1240 	u64 addr;
1241 
1242 	if (!kmap)
1243 		return -1;
1244 
1245 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1246 		return 0;
1247 
1248 	addr = kallsyms__get_function_start(filename,
1249 					    kmap->ref_reloc_sym->name);
1250 	if (!addr)
1251 		return -1;
1252 
1253 	*delta = addr - kmap->ref_reloc_sym->addr;
1254 	return 0;
1255 }
1256 
1257 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1258 			 struct map *map, bool no_kcore)
1259 {
1260 	u64 delta = 0;
1261 
1262 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1263 		return -1;
1264 
1265 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1266 		return -1;
1267 
1268 	if (kallsyms__delta(map, filename, &delta))
1269 		return -1;
1270 
1271 	symbols__fixup_end(&dso->symbols[map->type]);
1272 	symbols__fixup_duplicate(&dso->symbols[map->type]);
1273 
1274 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1275 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1276 	else
1277 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1278 
1279 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1280 		return dso__split_kallsyms_for_kcore(dso, map);
1281 	else
1282 		return dso__split_kallsyms(dso, map, delta);
1283 }
1284 
1285 int dso__load_kallsyms(struct dso *dso, const char *filename,
1286 		       struct map *map)
1287 {
1288 	return __dso__load_kallsyms(dso, filename, map, false);
1289 }
1290 
1291 static int dso__load_perf_map(struct dso *dso, struct map *map)
1292 {
1293 	char *line = NULL;
1294 	size_t n;
1295 	FILE *file;
1296 	int nr_syms = 0;
1297 
1298 	file = fopen(dso->long_name, "r");
1299 	if (file == NULL)
1300 		goto out_failure;
1301 
1302 	while (!feof(file)) {
1303 		u64 start, size;
1304 		struct symbol *sym;
1305 		int line_len, len;
1306 
1307 		line_len = getline(&line, &n, file);
1308 		if (line_len < 0)
1309 			break;
1310 
1311 		if (!line)
1312 			goto out_failure;
1313 
1314 		line[--line_len] = '\0'; /* \n */
1315 
1316 		len = hex2u64(line, &start);
1317 
1318 		len++;
1319 		if (len + 2 >= line_len)
1320 			continue;
1321 
1322 		len += hex2u64(line + len, &size);
1323 
1324 		len++;
1325 		if (len + 2 >= line_len)
1326 			continue;
1327 
1328 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1329 
1330 		if (sym == NULL)
1331 			goto out_delete_line;
1332 
1333 		symbols__insert(&dso->symbols[map->type], sym);
1334 		nr_syms++;
1335 	}
1336 
1337 	free(line);
1338 	fclose(file);
1339 
1340 	return nr_syms;
1341 
1342 out_delete_line:
1343 	free(line);
1344 out_failure:
1345 	return -1;
1346 }
1347 
1348 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1349 					   enum dso_binary_type type)
1350 {
1351 	switch (type) {
1352 	case DSO_BINARY_TYPE__JAVA_JIT:
1353 	case DSO_BINARY_TYPE__DEBUGLINK:
1354 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1355 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1356 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1357 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1358 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1359 		return !kmod && dso->kernel == DSO_TYPE_USER;
1360 
1361 	case DSO_BINARY_TYPE__KALLSYMS:
1362 	case DSO_BINARY_TYPE__VMLINUX:
1363 	case DSO_BINARY_TYPE__KCORE:
1364 		return dso->kernel == DSO_TYPE_KERNEL;
1365 
1366 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1367 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1368 	case DSO_BINARY_TYPE__GUEST_KCORE:
1369 		return dso->kernel == DSO_TYPE_GUEST_KERNEL;
1370 
1371 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1372 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1373 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1374 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1375 		/*
1376 		 * kernel modules know their symtab type - it's set when
1377 		 * creating a module dso in machine__findnew_module_map().
1378 		 */
1379 		return kmod && dso->symtab_type == type;
1380 
1381 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1382 		return true;
1383 
1384 	case DSO_BINARY_TYPE__NOT_FOUND:
1385 	default:
1386 		return false;
1387 	}
1388 }
1389 
1390 int dso__load(struct dso *dso, struct map *map)
1391 {
1392 	char *name;
1393 	int ret = -1;
1394 	u_int i;
1395 	struct machine *machine;
1396 	char *root_dir = (char *) "";
1397 	int ss_pos = 0;
1398 	struct symsrc ss_[2];
1399 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1400 	bool kmod;
1401 	unsigned char build_id[BUILD_ID_SIZE];
1402 
1403 	pthread_mutex_lock(&dso->lock);
1404 
1405 	/* check again under the dso->lock */
1406 	if (dso__loaded(dso, map->type)) {
1407 		ret = 1;
1408 		goto out;
1409 	}
1410 
1411 	if (dso->kernel) {
1412 		if (dso->kernel == DSO_TYPE_KERNEL)
1413 			ret = dso__load_kernel_sym(dso, map);
1414 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1415 			ret = dso__load_guest_kernel_sym(dso, map);
1416 
1417 		goto out;
1418 	}
1419 
1420 	if (map->groups && map->groups->machine)
1421 		machine = map->groups->machine;
1422 	else
1423 		machine = NULL;
1424 
1425 	dso->adjust_symbols = 0;
1426 
1427 	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1428 		struct stat st;
1429 
1430 		if (lstat(dso->name, &st) < 0)
1431 			goto out;
1432 
1433 		if (!symbol_conf.force && st.st_uid && (st.st_uid != geteuid())) {
1434 			pr_warning("File %s not owned by current user or root, "
1435 				   "ignoring it (use -f to override).\n", dso->name);
1436 			goto out;
1437 		}
1438 
1439 		ret = dso__load_perf_map(dso, map);
1440 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1441 					     DSO_BINARY_TYPE__NOT_FOUND;
1442 		goto out;
1443 	}
1444 
1445 	if (machine)
1446 		root_dir = machine->root_dir;
1447 
1448 	name = malloc(PATH_MAX);
1449 	if (!name)
1450 		goto out;
1451 
1452 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1453 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1454 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1455 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1456 
1457 
1458 	/*
1459 	 * Read the build id if possible. This is required for
1460 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1461 	 */
1462 	if (!dso->has_build_id &&
1463 	    is_regular_file(dso->long_name) &&
1464 	    filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0)
1465 		dso__set_build_id(dso, build_id);
1466 
1467 	/*
1468 	 * Iterate over candidate debug images.
1469 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1470 	 * and/or opd section) for processing.
1471 	 */
1472 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1473 		struct symsrc *ss = &ss_[ss_pos];
1474 		bool next_slot = false;
1475 
1476 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1477 
1478 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1479 			continue;
1480 
1481 		if (dso__read_binary_type_filename(dso, symtab_type,
1482 						   root_dir, name, PATH_MAX))
1483 			continue;
1484 
1485 		if (!is_regular_file(name))
1486 			continue;
1487 
1488 		/* Name is now the name of the next image to try */
1489 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1490 			continue;
1491 
1492 		if (!syms_ss && symsrc__has_symtab(ss)) {
1493 			syms_ss = ss;
1494 			next_slot = true;
1495 			if (!dso->symsrc_filename)
1496 				dso->symsrc_filename = strdup(name);
1497 		}
1498 
1499 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1500 			runtime_ss = ss;
1501 			next_slot = true;
1502 		}
1503 
1504 		if (next_slot) {
1505 			ss_pos++;
1506 
1507 			if (syms_ss && runtime_ss)
1508 				break;
1509 		} else {
1510 			symsrc__destroy(ss);
1511 		}
1512 
1513 	}
1514 
1515 	if (!runtime_ss && !syms_ss)
1516 		goto out_free;
1517 
1518 	if (runtime_ss && !syms_ss) {
1519 		syms_ss = runtime_ss;
1520 	}
1521 
1522 	/* We'll have to hope for the best */
1523 	if (!runtime_ss && syms_ss)
1524 		runtime_ss = syms_ss;
1525 
1526 	if (syms_ss && syms_ss->type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
1527 		if (dso__build_id_is_kmod(dso, name, PATH_MAX))
1528 			kmod = true;
1529 
1530 	if (syms_ss)
1531 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1532 	else
1533 		ret = -1;
1534 
1535 	if (ret > 0) {
1536 		int nr_plt;
1537 
1538 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map);
1539 		if (nr_plt > 0)
1540 			ret += nr_plt;
1541 	}
1542 
1543 	for (; ss_pos > 0; ss_pos--)
1544 		symsrc__destroy(&ss_[ss_pos - 1]);
1545 out_free:
1546 	free(name);
1547 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1548 		ret = 0;
1549 out:
1550 	dso__set_loaded(dso, map->type);
1551 	pthread_mutex_unlock(&dso->lock);
1552 
1553 	return ret;
1554 }
1555 
1556 struct map *map_groups__find_by_name(struct map_groups *mg,
1557 				     enum map_type type, const char *name)
1558 {
1559 	struct maps *maps = &mg->maps[type];
1560 	struct map *map;
1561 
1562 	pthread_rwlock_rdlock(&maps->lock);
1563 
1564 	for (map = maps__first(maps); map; map = map__next(map)) {
1565 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1566 			goto out_unlock;
1567 	}
1568 
1569 	map = NULL;
1570 
1571 out_unlock:
1572 	pthread_rwlock_unlock(&maps->lock);
1573 	return map;
1574 }
1575 
1576 int dso__load_vmlinux(struct dso *dso, struct map *map,
1577 		      const char *vmlinux, bool vmlinux_allocated)
1578 {
1579 	int err = -1;
1580 	struct symsrc ss;
1581 	char symfs_vmlinux[PATH_MAX];
1582 	enum dso_binary_type symtab_type;
1583 
1584 	if (vmlinux[0] == '/')
1585 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1586 	else
1587 		symbol__join_symfs(symfs_vmlinux, vmlinux);
1588 
1589 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1590 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1591 	else
1592 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1593 
1594 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1595 		return -1;
1596 
1597 	err = dso__load_sym(dso, map, &ss, &ss, 0);
1598 	symsrc__destroy(&ss);
1599 
1600 	if (err > 0) {
1601 		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1602 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1603 		else
1604 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1605 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1606 		dso__set_loaded(dso, map->type);
1607 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1608 	}
1609 
1610 	return err;
1611 }
1612 
1613 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
1614 {
1615 	int i, err = 0;
1616 	char *filename = NULL;
1617 
1618 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1619 		 vmlinux_path__nr_entries + 1);
1620 
1621 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1622 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
1623 		if (err > 0)
1624 			goto out;
1625 	}
1626 
1627 	if (!symbol_conf.ignore_vmlinux_buildid)
1628 		filename = dso__build_id_filename(dso, NULL, 0);
1629 	if (filename != NULL) {
1630 		err = dso__load_vmlinux(dso, map, filename, true);
1631 		if (err > 0)
1632 			goto out;
1633 		free(filename);
1634 	}
1635 out:
1636 	return err;
1637 }
1638 
1639 static bool visible_dir_filter(const char *name, struct dirent *d)
1640 {
1641 	if (d->d_type != DT_DIR)
1642 		return false;
1643 	return lsdir_no_dot_filter(name, d);
1644 }
1645 
1646 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1647 {
1648 	char kallsyms_filename[PATH_MAX];
1649 	int ret = -1;
1650 	struct strlist *dirs;
1651 	struct str_node *nd;
1652 
1653 	dirs = lsdir(dir, visible_dir_filter);
1654 	if (!dirs)
1655 		return -1;
1656 
1657 	strlist__for_each_entry(nd, dirs) {
1658 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1659 			  "%s/%s/kallsyms", dir, nd->s);
1660 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
1661 			strlcpy(dir, kallsyms_filename, dir_sz);
1662 			ret = 0;
1663 			break;
1664 		}
1665 	}
1666 
1667 	strlist__delete(dirs);
1668 
1669 	return ret;
1670 }
1671 
1672 /*
1673  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
1674  * since access(R_OK) only checks with real UID/GID but open() use effective
1675  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
1676  */
1677 static bool filename__readable(const char *file)
1678 {
1679 	int fd = open(file, O_RDONLY);
1680 	if (fd < 0)
1681 		return false;
1682 	close(fd);
1683 	return true;
1684 }
1685 
1686 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1687 {
1688 	u8 host_build_id[BUILD_ID_SIZE];
1689 	char sbuild_id[SBUILD_ID_SIZE];
1690 	bool is_host = false;
1691 	char path[PATH_MAX];
1692 
1693 	if (!dso->has_build_id) {
1694 		/*
1695 		 * Last resort, if we don't have a build-id and couldn't find
1696 		 * any vmlinux file, try the running kernel kallsyms table.
1697 		 */
1698 		goto proc_kallsyms;
1699 	}
1700 
1701 	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1702 				 sizeof(host_build_id)) == 0)
1703 		is_host = dso__build_id_equal(dso, host_build_id);
1704 
1705 	/* Try a fast path for /proc/kallsyms if possible */
1706 	if (is_host) {
1707 		/*
1708 		 * Do not check the build-id cache, unless we know we cannot use
1709 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
1710 		 * To check readability of /proc/kcore, do not use access(R_OK)
1711 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
1712 		 * can't check it.
1713 		 */
1714 		if (filename__readable("/proc/kcore") &&
1715 		    !validate_kcore_addresses("/proc/kallsyms", map))
1716 			goto proc_kallsyms;
1717 	}
1718 
1719 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1720 
1721 	/* Find kallsyms in build-id cache with kcore */
1722 	scnprintf(path, sizeof(path), "%s/%s/%s",
1723 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
1724 
1725 	if (!find_matching_kcore(map, path, sizeof(path)))
1726 		return strdup(path);
1727 
1728 	/* Use current /proc/kallsyms if possible */
1729 	if (is_host) {
1730 proc_kallsyms:
1731 		return strdup("/proc/kallsyms");
1732 	}
1733 
1734 	/* Finally, find a cache of kallsyms */
1735 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
1736 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1737 		       sbuild_id);
1738 		return NULL;
1739 	}
1740 
1741 	return strdup(path);
1742 }
1743 
1744 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
1745 {
1746 	int err;
1747 	const char *kallsyms_filename = NULL;
1748 	char *kallsyms_allocated_filename = NULL;
1749 	/*
1750 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1751 	 * it and only it, reporting errors to the user if it cannot be used.
1752 	 *
1753 	 * For instance, try to analyse an ARM perf.data file _without_ a
1754 	 * build-id, or if the user specifies the wrong path to the right
1755 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1756 	 * x86_86 one, on the machine where analysis is being performed, say),
1757 	 * or worse, /proc/kallsyms.
1758 	 *
1759 	 * If the specified file _has_ a build-id and there is a build-id
1760 	 * section in the perf.data file, we will still do the expected
1761 	 * validation in dso__load_vmlinux and will bail out if they don't
1762 	 * match.
1763 	 */
1764 	if (symbol_conf.kallsyms_name != NULL) {
1765 		kallsyms_filename = symbol_conf.kallsyms_name;
1766 		goto do_kallsyms;
1767 	}
1768 
1769 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1770 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
1771 	}
1772 
1773 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1774 		err = dso__load_vmlinux_path(dso, map);
1775 		if (err > 0)
1776 			return err;
1777 	}
1778 
1779 	/* do not try local files if a symfs was given */
1780 	if (symbol_conf.symfs[0] != 0)
1781 		return -1;
1782 
1783 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1784 	if (!kallsyms_allocated_filename)
1785 		return -1;
1786 
1787 	kallsyms_filename = kallsyms_allocated_filename;
1788 
1789 do_kallsyms:
1790 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
1791 	if (err > 0)
1792 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1793 	free(kallsyms_allocated_filename);
1794 
1795 	if (err > 0 && !dso__is_kcore(dso)) {
1796 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
1797 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
1798 		map__fixup_start(map);
1799 		map__fixup_end(map);
1800 	}
1801 
1802 	return err;
1803 }
1804 
1805 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
1806 {
1807 	int err;
1808 	const char *kallsyms_filename = NULL;
1809 	struct machine *machine;
1810 	char path[PATH_MAX];
1811 
1812 	if (!map->groups) {
1813 		pr_debug("Guest kernel map hasn't the point to groups\n");
1814 		return -1;
1815 	}
1816 	machine = map->groups->machine;
1817 
1818 	if (machine__is_default_guest(machine)) {
1819 		/*
1820 		 * if the user specified a vmlinux filename, use it and only
1821 		 * it, reporting errors to the user if it cannot be used.
1822 		 * Or use file guest_kallsyms inputted by user on commandline
1823 		 */
1824 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1825 			err = dso__load_vmlinux(dso, map,
1826 						symbol_conf.default_guest_vmlinux_name,
1827 						false);
1828 			return err;
1829 		}
1830 
1831 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
1832 		if (!kallsyms_filename)
1833 			return -1;
1834 	} else {
1835 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1836 		kallsyms_filename = path;
1837 	}
1838 
1839 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
1840 	if (err > 0)
1841 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1842 	if (err > 0 && !dso__is_kcore(dso)) {
1843 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1844 		machine__mmap_name(machine, path, sizeof(path));
1845 		dso__set_long_name(dso, strdup(path), true);
1846 		map__fixup_start(map);
1847 		map__fixup_end(map);
1848 	}
1849 
1850 	return err;
1851 }
1852 
1853 static void vmlinux_path__exit(void)
1854 {
1855 	while (--vmlinux_path__nr_entries >= 0)
1856 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1857 	vmlinux_path__nr_entries = 0;
1858 
1859 	zfree(&vmlinux_path);
1860 }
1861 
1862 static const char * const vmlinux_paths[] = {
1863 	"vmlinux",
1864 	"/boot/vmlinux"
1865 };
1866 
1867 static const char * const vmlinux_paths_upd[] = {
1868 	"/boot/vmlinux-%s",
1869 	"/usr/lib/debug/boot/vmlinux-%s",
1870 	"/lib/modules/%s/build/vmlinux",
1871 	"/usr/lib/debug/lib/modules/%s/vmlinux",
1872 	"/usr/lib/debug/boot/vmlinux-%s.debug"
1873 };
1874 
1875 static int vmlinux_path__add(const char *new_entry)
1876 {
1877 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
1878 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1879 		return -1;
1880 	++vmlinux_path__nr_entries;
1881 
1882 	return 0;
1883 }
1884 
1885 static int vmlinux_path__init(struct perf_env *env)
1886 {
1887 	struct utsname uts;
1888 	char bf[PATH_MAX];
1889 	char *kernel_version;
1890 	unsigned int i;
1891 
1892 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
1893 			      ARRAY_SIZE(vmlinux_paths_upd)));
1894 	if (vmlinux_path == NULL)
1895 		return -1;
1896 
1897 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
1898 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
1899 			goto out_fail;
1900 
1901 	/* only try kernel version if no symfs was given */
1902 	if (symbol_conf.symfs[0] != 0)
1903 		return 0;
1904 
1905 	if (env) {
1906 		kernel_version = env->os_release;
1907 	} else {
1908 		if (uname(&uts) < 0)
1909 			goto out_fail;
1910 
1911 		kernel_version = uts.release;
1912 	}
1913 
1914 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
1915 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
1916 		if (vmlinux_path__add(bf) < 0)
1917 			goto out_fail;
1918 	}
1919 
1920 	return 0;
1921 
1922 out_fail:
1923 	vmlinux_path__exit();
1924 	return -1;
1925 }
1926 
1927 int setup_list(struct strlist **list, const char *list_str,
1928 		      const char *list_name)
1929 {
1930 	if (list_str == NULL)
1931 		return 0;
1932 
1933 	*list = strlist__new(list_str, NULL);
1934 	if (!*list) {
1935 		pr_err("problems parsing %s list\n", list_name);
1936 		return -1;
1937 	}
1938 
1939 	symbol_conf.has_filter = true;
1940 	return 0;
1941 }
1942 
1943 int setup_intlist(struct intlist **list, const char *list_str,
1944 		  const char *list_name)
1945 {
1946 	if (list_str == NULL)
1947 		return 0;
1948 
1949 	*list = intlist__new(list_str);
1950 	if (!*list) {
1951 		pr_err("problems parsing %s list\n", list_name);
1952 		return -1;
1953 	}
1954 	return 0;
1955 }
1956 
1957 static bool symbol__read_kptr_restrict(void)
1958 {
1959 	bool value = false;
1960 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1961 
1962 	if (fp != NULL) {
1963 		char line[8];
1964 
1965 		if (fgets(line, sizeof(line), fp) != NULL)
1966 			value = ((geteuid() != 0) || (getuid() != 0)) ?
1967 					(atoi(line) != 0) :
1968 					(atoi(line) == 2);
1969 
1970 		fclose(fp);
1971 	}
1972 
1973 	return value;
1974 }
1975 
1976 int symbol__annotation_init(void)
1977 {
1978 	if (symbol_conf.initialized) {
1979 		pr_err("Annotation needs to be init before symbol__init()\n");
1980 		return -1;
1981 	}
1982 
1983 	if (symbol_conf.init_annotation) {
1984 		pr_warning("Annotation being initialized multiple times\n");
1985 		return 0;
1986 	}
1987 
1988 	symbol_conf.priv_size += sizeof(struct annotation);
1989 	symbol_conf.init_annotation = true;
1990 	return 0;
1991 }
1992 
1993 int symbol__init(struct perf_env *env)
1994 {
1995 	const char *symfs;
1996 
1997 	if (symbol_conf.initialized)
1998 		return 0;
1999 
2000 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2001 
2002 	symbol__elf_init();
2003 
2004 	if (symbol_conf.sort_by_name)
2005 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2006 					  sizeof(struct symbol));
2007 
2008 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2009 		return -1;
2010 
2011 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2012 		pr_err("'.' is the only non valid --field-separator argument\n");
2013 		return -1;
2014 	}
2015 
2016 	if (setup_list(&symbol_conf.dso_list,
2017 		       symbol_conf.dso_list_str, "dso") < 0)
2018 		return -1;
2019 
2020 	if (setup_list(&symbol_conf.comm_list,
2021 		       symbol_conf.comm_list_str, "comm") < 0)
2022 		goto out_free_dso_list;
2023 
2024 	if (setup_intlist(&symbol_conf.pid_list,
2025 		       symbol_conf.pid_list_str, "pid") < 0)
2026 		goto out_free_comm_list;
2027 
2028 	if (setup_intlist(&symbol_conf.tid_list,
2029 		       symbol_conf.tid_list_str, "tid") < 0)
2030 		goto out_free_pid_list;
2031 
2032 	if (setup_list(&symbol_conf.sym_list,
2033 		       symbol_conf.sym_list_str, "symbol") < 0)
2034 		goto out_free_tid_list;
2035 
2036 	if (setup_list(&symbol_conf.bt_stop_list,
2037 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2038 		goto out_free_sym_list;
2039 
2040 	/*
2041 	 * A path to symbols of "/" is identical to ""
2042 	 * reset here for simplicity.
2043 	 */
2044 	symfs = realpath(symbol_conf.symfs, NULL);
2045 	if (symfs == NULL)
2046 		symfs = symbol_conf.symfs;
2047 	if (strcmp(symfs, "/") == 0)
2048 		symbol_conf.symfs = "";
2049 	if (symfs != symbol_conf.symfs)
2050 		free((void *)symfs);
2051 
2052 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2053 
2054 	symbol_conf.initialized = true;
2055 	return 0;
2056 
2057 out_free_sym_list:
2058 	strlist__delete(symbol_conf.sym_list);
2059 out_free_tid_list:
2060 	intlist__delete(symbol_conf.tid_list);
2061 out_free_pid_list:
2062 	intlist__delete(symbol_conf.pid_list);
2063 out_free_comm_list:
2064 	strlist__delete(symbol_conf.comm_list);
2065 out_free_dso_list:
2066 	strlist__delete(symbol_conf.dso_list);
2067 	return -1;
2068 }
2069 
2070 void symbol__exit(void)
2071 {
2072 	if (!symbol_conf.initialized)
2073 		return;
2074 	strlist__delete(symbol_conf.bt_stop_list);
2075 	strlist__delete(symbol_conf.sym_list);
2076 	strlist__delete(symbol_conf.dso_list);
2077 	strlist__delete(symbol_conf.comm_list);
2078 	intlist__delete(symbol_conf.tid_list);
2079 	intlist__delete(symbol_conf.pid_list);
2080 	vmlinux_path__exit();
2081 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2082 	symbol_conf.bt_stop_list = NULL;
2083 	symbol_conf.initialized = false;
2084 }
2085 
2086 int symbol__config_symfs(const struct option *opt __maybe_unused,
2087 			 const char *dir, int unset __maybe_unused)
2088 {
2089 	char *bf = NULL;
2090 	int ret;
2091 
2092 	symbol_conf.symfs = strdup(dir);
2093 	if (symbol_conf.symfs == NULL)
2094 		return -ENOMEM;
2095 
2096 	/* skip the locally configured cache if a symfs is given, and
2097 	 * config buildid dir to symfs/.debug
2098 	 */
2099 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2100 	if (ret < 0)
2101 		return -ENOMEM;
2102 
2103 	set_buildid_dir(bf);
2104 
2105 	free(bf);
2106 	return 0;
2107 }
2108