xref: /openbmc/linux/tools/perf/util/symbol.c (revision 79f08d9e)
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 "build-id.h"
13 #include "util.h"
14 #include "debug.h"
15 #include "machine.h"
16 #include "symbol.h"
17 #include "strlist.h"
18 
19 #include <elf.h>
20 #include <limits.h>
21 #include <sys/utsname.h>
22 
23 #ifndef KSYM_NAME_LEN
24 #define KSYM_NAME_LEN 256
25 #endif
26 
27 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
28 				symbol_filter_t filter);
29 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
30 			symbol_filter_t filter);
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 	.symfs            = "",
40 };
41 
42 static enum dso_binary_type binary_type_symtab[] = {
43 	DSO_BINARY_TYPE__KALLSYMS,
44 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
45 	DSO_BINARY_TYPE__JAVA_JIT,
46 	DSO_BINARY_TYPE__DEBUGLINK,
47 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
48 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
49 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
50 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
51 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
52 	DSO_BINARY_TYPE__GUEST_KMODULE,
53 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
54 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
55 	DSO_BINARY_TYPE__NOT_FOUND,
56 };
57 
58 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
59 
60 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
61 {
62 	symbol_type = toupper(symbol_type);
63 
64 	switch (map_type) {
65 	case MAP__FUNCTION:
66 		return symbol_type == 'T' || symbol_type == 'W';
67 	case MAP__VARIABLE:
68 		return symbol_type == 'D';
69 	default:
70 		return false;
71 	}
72 }
73 
74 static int prefix_underscores_count(const char *str)
75 {
76 	const char *tail = str;
77 
78 	while (*tail == '_')
79 		tail++;
80 
81 	return tail - str;
82 }
83 
84 #define SYMBOL_A 0
85 #define SYMBOL_B 1
86 
87 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
88 {
89 	s64 a;
90 	s64 b;
91 	size_t na, nb;
92 
93 	/* Prefer a symbol with non zero length */
94 	a = syma->end - syma->start;
95 	b = symb->end - symb->start;
96 	if ((b == 0) && (a > 0))
97 		return SYMBOL_A;
98 	else if ((a == 0) && (b > 0))
99 		return SYMBOL_B;
100 
101 	/* Prefer a non weak symbol over a weak one */
102 	a = syma->binding == STB_WEAK;
103 	b = symb->binding == STB_WEAK;
104 	if (b && !a)
105 		return SYMBOL_A;
106 	if (a && !b)
107 		return SYMBOL_B;
108 
109 	/* Prefer a global symbol over a non global one */
110 	a = syma->binding == STB_GLOBAL;
111 	b = symb->binding == STB_GLOBAL;
112 	if (a && !b)
113 		return SYMBOL_A;
114 	if (b && !a)
115 		return SYMBOL_B;
116 
117 	/* Prefer a symbol with less underscores */
118 	a = prefix_underscores_count(syma->name);
119 	b = prefix_underscores_count(symb->name);
120 	if (b > a)
121 		return SYMBOL_A;
122 	else if (a > b)
123 		return SYMBOL_B;
124 
125 	/* Choose the symbol with the longest name */
126 	na = strlen(syma->name);
127 	nb = strlen(symb->name);
128 	if (na > nb)
129 		return SYMBOL_A;
130 	else if (na < nb)
131 		return SYMBOL_B;
132 
133 	/* Avoid "SyS" kernel syscall aliases */
134 	if (na >= 3 && !strncmp(syma->name, "SyS", 3))
135 		return SYMBOL_B;
136 	if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
137 		return SYMBOL_B;
138 
139 	return SYMBOL_A;
140 }
141 
142 void symbols__fixup_duplicate(struct rb_root *symbols)
143 {
144 	struct rb_node *nd;
145 	struct symbol *curr, *next;
146 
147 	nd = rb_first(symbols);
148 
149 	while (nd) {
150 		curr = rb_entry(nd, struct symbol, rb_node);
151 again:
152 		nd = rb_next(&curr->rb_node);
153 		next = rb_entry(nd, struct symbol, rb_node);
154 
155 		if (!nd)
156 			break;
157 
158 		if (curr->start != next->start)
159 			continue;
160 
161 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
162 			rb_erase(&next->rb_node, symbols);
163 			symbol__delete(next);
164 			goto again;
165 		} else {
166 			nd = rb_next(&curr->rb_node);
167 			rb_erase(&curr->rb_node, symbols);
168 			symbol__delete(curr);
169 		}
170 	}
171 }
172 
173 void symbols__fixup_end(struct rb_root *symbols)
174 {
175 	struct rb_node *nd, *prevnd = rb_first(symbols);
176 	struct symbol *curr, *prev;
177 
178 	if (prevnd == NULL)
179 		return;
180 
181 	curr = rb_entry(prevnd, struct symbol, rb_node);
182 
183 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
184 		prev = curr;
185 		curr = rb_entry(nd, struct symbol, rb_node);
186 
187 		if (prev->end == prev->start && prev->end != curr->start)
188 			prev->end = curr->start - 1;
189 	}
190 
191 	/* Last entry */
192 	if (curr->end == curr->start)
193 		curr->end = roundup(curr->start, 4096);
194 }
195 
196 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
197 {
198 	struct map *prev, *curr;
199 	struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
200 
201 	if (prevnd == NULL)
202 		return;
203 
204 	curr = rb_entry(prevnd, struct map, rb_node);
205 
206 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
207 		prev = curr;
208 		curr = rb_entry(nd, struct map, rb_node);
209 		prev->end = curr->start - 1;
210 	}
211 
212 	/*
213 	 * We still haven't the actual symbols, so guess the
214 	 * last map final address.
215 	 */
216 	curr->end = ~0ULL;
217 }
218 
219 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
220 {
221 	size_t namelen = strlen(name) + 1;
222 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
223 					sizeof(*sym) + namelen));
224 	if (sym == NULL)
225 		return NULL;
226 
227 	if (symbol_conf.priv_size)
228 		sym = ((void *)sym) + symbol_conf.priv_size;
229 
230 	sym->start   = start;
231 	sym->end     = len ? start + len - 1 : start;
232 	sym->binding = binding;
233 	sym->namelen = namelen - 1;
234 
235 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
236 		  __func__, name, start, sym->end);
237 	memcpy(sym->name, name, namelen);
238 
239 	return sym;
240 }
241 
242 void symbol__delete(struct symbol *sym)
243 {
244 	free(((void *)sym) - symbol_conf.priv_size);
245 }
246 
247 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
248 {
249 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
250 		       sym->start, sym->end,
251 		       sym->binding == STB_GLOBAL ? 'g' :
252 		       sym->binding == STB_LOCAL  ? 'l' : 'w',
253 		       sym->name);
254 }
255 
256 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
257 				    const struct addr_location *al, FILE *fp)
258 {
259 	unsigned long offset;
260 	size_t length;
261 
262 	if (sym && sym->name) {
263 		length = fprintf(fp, "%s", sym->name);
264 		if (al) {
265 			if (al->addr < sym->end)
266 				offset = al->addr - sym->start;
267 			else
268 				offset = al->addr - al->map->start - sym->start;
269 			length += fprintf(fp, "+0x%lx", offset);
270 		}
271 		return length;
272 	} else
273 		return fprintf(fp, "[unknown]");
274 }
275 
276 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
277 {
278 	return symbol__fprintf_symname_offs(sym, NULL, fp);
279 }
280 
281 void symbols__delete(struct rb_root *symbols)
282 {
283 	struct symbol *pos;
284 	struct rb_node *next = rb_first(symbols);
285 
286 	while (next) {
287 		pos = rb_entry(next, struct symbol, rb_node);
288 		next = rb_next(&pos->rb_node);
289 		rb_erase(&pos->rb_node, symbols);
290 		symbol__delete(pos);
291 	}
292 }
293 
294 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
295 {
296 	struct rb_node **p = &symbols->rb_node;
297 	struct rb_node *parent = NULL;
298 	const u64 ip = sym->start;
299 	struct symbol *s;
300 
301 	while (*p != NULL) {
302 		parent = *p;
303 		s = rb_entry(parent, struct symbol, rb_node);
304 		if (ip < s->start)
305 			p = &(*p)->rb_left;
306 		else
307 			p = &(*p)->rb_right;
308 	}
309 	rb_link_node(&sym->rb_node, parent, p);
310 	rb_insert_color(&sym->rb_node, symbols);
311 }
312 
313 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
314 {
315 	struct rb_node *n;
316 
317 	if (symbols == NULL)
318 		return NULL;
319 
320 	n = symbols->rb_node;
321 
322 	while (n) {
323 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
324 
325 		if (ip < s->start)
326 			n = n->rb_left;
327 		else if (ip > s->end)
328 			n = n->rb_right;
329 		else
330 			return s;
331 	}
332 
333 	return NULL;
334 }
335 
336 static struct symbol *symbols__first(struct rb_root *symbols)
337 {
338 	struct rb_node *n = rb_first(symbols);
339 
340 	if (n)
341 		return rb_entry(n, struct symbol, rb_node);
342 
343 	return NULL;
344 }
345 
346 struct symbol_name_rb_node {
347 	struct rb_node	rb_node;
348 	struct symbol	sym;
349 };
350 
351 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
352 {
353 	struct rb_node **p = &symbols->rb_node;
354 	struct rb_node *parent = NULL;
355 	struct symbol_name_rb_node *symn, *s;
356 
357 	symn = container_of(sym, struct symbol_name_rb_node, sym);
358 
359 	while (*p != NULL) {
360 		parent = *p;
361 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
362 		if (strcmp(sym->name, s->sym.name) < 0)
363 			p = &(*p)->rb_left;
364 		else
365 			p = &(*p)->rb_right;
366 	}
367 	rb_link_node(&symn->rb_node, parent, p);
368 	rb_insert_color(&symn->rb_node, symbols);
369 }
370 
371 static void symbols__sort_by_name(struct rb_root *symbols,
372 				  struct rb_root *source)
373 {
374 	struct rb_node *nd;
375 
376 	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
377 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
378 		symbols__insert_by_name(symbols, pos);
379 	}
380 }
381 
382 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
383 					    const char *name)
384 {
385 	struct rb_node *n;
386 
387 	if (symbols == NULL)
388 		return NULL;
389 
390 	n = symbols->rb_node;
391 
392 	while (n) {
393 		struct symbol_name_rb_node *s;
394 		int cmp;
395 
396 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
397 		cmp = strcmp(name, s->sym.name);
398 
399 		if (cmp < 0)
400 			n = n->rb_left;
401 		else if (cmp > 0)
402 			n = n->rb_right;
403 		else
404 			return &s->sym;
405 	}
406 
407 	return NULL;
408 }
409 
410 struct symbol *dso__find_symbol(struct dso *dso,
411 				enum map_type type, u64 addr)
412 {
413 	return symbols__find(&dso->symbols[type], addr);
414 }
415 
416 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
417 {
418 	return symbols__first(&dso->symbols[type]);
419 }
420 
421 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
422 					const char *name)
423 {
424 	return symbols__find_by_name(&dso->symbol_names[type], name);
425 }
426 
427 void dso__sort_by_name(struct dso *dso, enum map_type type)
428 {
429 	dso__set_sorted_by_name(dso, type);
430 	return symbols__sort_by_name(&dso->symbol_names[type],
431 				     &dso->symbols[type]);
432 }
433 
434 size_t dso__fprintf_symbols_by_name(struct dso *dso,
435 				    enum map_type type, FILE *fp)
436 {
437 	size_t ret = 0;
438 	struct rb_node *nd;
439 	struct symbol_name_rb_node *pos;
440 
441 	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
442 		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
443 		fprintf(fp, "%s\n", pos->sym.name);
444 	}
445 
446 	return ret;
447 }
448 
449 int kallsyms__parse(const char *filename, void *arg,
450 		    int (*process_symbol)(void *arg, const char *name,
451 					  char type, u64 start))
452 {
453 	char *line = NULL;
454 	size_t n;
455 	int err = -1;
456 	FILE *file = fopen(filename, "r");
457 
458 	if (file == NULL)
459 		goto out_failure;
460 
461 	err = 0;
462 
463 	while (!feof(file)) {
464 		u64 start;
465 		int line_len, len;
466 		char symbol_type;
467 		char *symbol_name;
468 
469 		line_len = getline(&line, &n, file);
470 		if (line_len < 0 || !line)
471 			break;
472 
473 		line[--line_len] = '\0'; /* \n */
474 
475 		len = hex2u64(line, &start);
476 
477 		len++;
478 		if (len + 2 >= line_len)
479 			continue;
480 
481 		symbol_type = line[len];
482 		len += 2;
483 		symbol_name = line + len;
484 		len = line_len - len;
485 
486 		if (len >= KSYM_NAME_LEN) {
487 			err = -1;
488 			break;
489 		}
490 
491 		err = process_symbol(arg, symbol_name,
492 				     symbol_type, start);
493 		if (err)
494 			break;
495 	}
496 
497 	free(line);
498 	fclose(file);
499 	return err;
500 
501 out_failure:
502 	return -1;
503 }
504 
505 int modules__parse(const char *filename, void *arg,
506 		   int (*process_module)(void *arg, const char *name,
507 					 u64 start))
508 {
509 	char *line = NULL;
510 	size_t n;
511 	FILE *file;
512 	int err = 0;
513 
514 	file = fopen(filename, "r");
515 	if (file == NULL)
516 		return -1;
517 
518 	while (1) {
519 		char name[PATH_MAX];
520 		u64 start;
521 		char *sep;
522 		ssize_t line_len;
523 
524 		line_len = getline(&line, &n, file);
525 		if (line_len < 0) {
526 			if (feof(file))
527 				break;
528 			err = -1;
529 			goto out;
530 		}
531 
532 		if (!line) {
533 			err = -1;
534 			goto out;
535 		}
536 
537 		line[--line_len] = '\0'; /* \n */
538 
539 		sep = strrchr(line, 'x');
540 		if (sep == NULL)
541 			continue;
542 
543 		hex2u64(sep + 1, &start);
544 
545 		sep = strchr(line, ' ');
546 		if (sep == NULL)
547 			continue;
548 
549 		*sep = '\0';
550 
551 		scnprintf(name, sizeof(name), "[%s]", line);
552 
553 		err = process_module(arg, name, start);
554 		if (err)
555 			break;
556 	}
557 out:
558 	free(line);
559 	fclose(file);
560 	return err;
561 }
562 
563 struct process_kallsyms_args {
564 	struct map *map;
565 	struct dso *dso;
566 };
567 
568 static u8 kallsyms2elf_type(char type)
569 {
570 	if (type == 'W')
571 		return STB_WEAK;
572 
573 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
574 }
575 
576 static int map__process_kallsym_symbol(void *arg, const char *name,
577 				       char type, u64 start)
578 {
579 	struct symbol *sym;
580 	struct process_kallsyms_args *a = arg;
581 	struct rb_root *root = &a->dso->symbols[a->map->type];
582 
583 	if (!symbol_type__is_a(type, a->map->type))
584 		return 0;
585 
586 	/*
587 	 * module symbols are not sorted so we add all
588 	 * symbols, setting length to 0, and rely on
589 	 * symbols__fixup_end() to fix it up.
590 	 */
591 	sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
592 	if (sym == NULL)
593 		return -ENOMEM;
594 	/*
595 	 * We will pass the symbols to the filter later, in
596 	 * map__split_kallsyms, when we have split the maps per module
597 	 */
598 	symbols__insert(root, sym);
599 
600 	return 0;
601 }
602 
603 /*
604  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
605  * so that we can in the next step set the symbol ->end address and then
606  * call kernel_maps__split_kallsyms.
607  */
608 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
609 				  struct map *map)
610 {
611 	struct process_kallsyms_args args = { .map = map, .dso = dso, };
612 	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
613 }
614 
615 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
616 					 symbol_filter_t filter)
617 {
618 	struct map_groups *kmaps = map__kmap(map)->kmaps;
619 	struct map *curr_map;
620 	struct symbol *pos;
621 	int count = 0, moved = 0;
622 	struct rb_root *root = &dso->symbols[map->type];
623 	struct rb_node *next = rb_first(root);
624 
625 	while (next) {
626 		char *module;
627 
628 		pos = rb_entry(next, struct symbol, rb_node);
629 		next = rb_next(&pos->rb_node);
630 
631 		module = strchr(pos->name, '\t');
632 		if (module)
633 			*module = '\0';
634 
635 		curr_map = map_groups__find(kmaps, map->type, pos->start);
636 
637 		if (!curr_map || (filter && filter(curr_map, pos))) {
638 			rb_erase(&pos->rb_node, root);
639 			symbol__delete(pos);
640 		} else {
641 			pos->start -= curr_map->start - curr_map->pgoff;
642 			if (pos->end)
643 				pos->end -= curr_map->start - curr_map->pgoff;
644 			if (curr_map != map) {
645 				rb_erase(&pos->rb_node, root);
646 				symbols__insert(
647 					&curr_map->dso->symbols[curr_map->type],
648 					pos);
649 				++moved;
650 			} else {
651 				++count;
652 			}
653 		}
654 	}
655 
656 	/* Symbols have been adjusted */
657 	dso->adjust_symbols = 1;
658 
659 	return count + moved;
660 }
661 
662 /*
663  * Split the symbols into maps, making sure there are no overlaps, i.e. the
664  * kernel range is broken in several maps, named [kernel].N, as we don't have
665  * the original ELF section names vmlinux have.
666  */
667 static int dso__split_kallsyms(struct dso *dso, struct map *map,
668 			       symbol_filter_t filter)
669 {
670 	struct map_groups *kmaps = map__kmap(map)->kmaps;
671 	struct machine *machine = kmaps->machine;
672 	struct map *curr_map = map;
673 	struct symbol *pos;
674 	int count = 0, moved = 0;
675 	struct rb_root *root = &dso->symbols[map->type];
676 	struct rb_node *next = rb_first(root);
677 	int kernel_range = 0;
678 
679 	while (next) {
680 		char *module;
681 
682 		pos = rb_entry(next, struct symbol, rb_node);
683 		next = rb_next(&pos->rb_node);
684 
685 		module = strchr(pos->name, '\t');
686 		if (module) {
687 			if (!symbol_conf.use_modules)
688 				goto discard_symbol;
689 
690 			*module++ = '\0';
691 
692 			if (strcmp(curr_map->dso->short_name, module)) {
693 				if (curr_map != map &&
694 				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
695 				    machine__is_default_guest(machine)) {
696 					/*
697 					 * We assume all symbols of a module are
698 					 * continuous in * kallsyms, so curr_map
699 					 * points to a module and all its
700 					 * symbols are in its kmap. Mark it as
701 					 * loaded.
702 					 */
703 					dso__set_loaded(curr_map->dso,
704 							curr_map->type);
705 				}
706 
707 				curr_map = map_groups__find_by_name(kmaps,
708 							map->type, module);
709 				if (curr_map == NULL) {
710 					pr_debug("%s/proc/{kallsyms,modules} "
711 					         "inconsistency while looking "
712 						 "for \"%s\" module!\n",
713 						 machine->root_dir, module);
714 					curr_map = map;
715 					goto discard_symbol;
716 				}
717 
718 				if (curr_map->dso->loaded &&
719 				    !machine__is_default_guest(machine))
720 					goto discard_symbol;
721 			}
722 			/*
723 			 * So that we look just like we get from .ko files,
724 			 * i.e. not prelinked, relative to map->start.
725 			 */
726 			pos->start = curr_map->map_ip(curr_map, pos->start);
727 			pos->end   = curr_map->map_ip(curr_map, pos->end);
728 		} else if (curr_map != map) {
729 			char dso_name[PATH_MAX];
730 			struct dso *ndso;
731 
732 			if (count == 0) {
733 				curr_map = map;
734 				goto filter_symbol;
735 			}
736 
737 			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
738 				snprintf(dso_name, sizeof(dso_name),
739 					"[guest.kernel].%d",
740 					kernel_range++);
741 			else
742 				snprintf(dso_name, sizeof(dso_name),
743 					"[kernel].%d",
744 					kernel_range++);
745 
746 			ndso = dso__new(dso_name);
747 			if (ndso == NULL)
748 				return -1;
749 
750 			ndso->kernel = dso->kernel;
751 
752 			curr_map = map__new2(pos->start, ndso, map->type);
753 			if (curr_map == NULL) {
754 				dso__delete(ndso);
755 				return -1;
756 			}
757 
758 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
759 			map_groups__insert(kmaps, curr_map);
760 			++kernel_range;
761 		}
762 filter_symbol:
763 		if (filter && filter(curr_map, pos)) {
764 discard_symbol:		rb_erase(&pos->rb_node, root);
765 			symbol__delete(pos);
766 		} else {
767 			if (curr_map != map) {
768 				rb_erase(&pos->rb_node, root);
769 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
770 				++moved;
771 			} else
772 				++count;
773 		}
774 	}
775 
776 	if (curr_map != map &&
777 	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
778 	    machine__is_default_guest(kmaps->machine)) {
779 		dso__set_loaded(curr_map->dso, curr_map->type);
780 	}
781 
782 	return count + moved;
783 }
784 
785 bool symbol__restricted_filename(const char *filename,
786 				 const char *restricted_filename)
787 {
788 	bool restricted = false;
789 
790 	if (symbol_conf.kptr_restrict) {
791 		char *r = realpath(filename, NULL);
792 
793 		if (r != NULL) {
794 			restricted = strcmp(r, restricted_filename) == 0;
795 			free(r);
796 			return restricted;
797 		}
798 	}
799 
800 	return restricted;
801 }
802 
803 struct module_info {
804 	struct rb_node rb_node;
805 	char *name;
806 	u64 start;
807 };
808 
809 static void add_module(struct module_info *mi, struct rb_root *modules)
810 {
811 	struct rb_node **p = &modules->rb_node;
812 	struct rb_node *parent = NULL;
813 	struct module_info *m;
814 
815 	while (*p != NULL) {
816 		parent = *p;
817 		m = rb_entry(parent, struct module_info, rb_node);
818 		if (strcmp(mi->name, m->name) < 0)
819 			p = &(*p)->rb_left;
820 		else
821 			p = &(*p)->rb_right;
822 	}
823 	rb_link_node(&mi->rb_node, parent, p);
824 	rb_insert_color(&mi->rb_node, modules);
825 }
826 
827 static void delete_modules(struct rb_root *modules)
828 {
829 	struct module_info *mi;
830 	struct rb_node *next = rb_first(modules);
831 
832 	while (next) {
833 		mi = rb_entry(next, struct module_info, rb_node);
834 		next = rb_next(&mi->rb_node);
835 		rb_erase(&mi->rb_node, modules);
836 		free(mi->name);
837 		free(mi);
838 	}
839 }
840 
841 static struct module_info *find_module(const char *name,
842 				       struct rb_root *modules)
843 {
844 	struct rb_node *n = modules->rb_node;
845 
846 	while (n) {
847 		struct module_info *m;
848 		int cmp;
849 
850 		m = rb_entry(n, struct module_info, rb_node);
851 		cmp = strcmp(name, m->name);
852 		if (cmp < 0)
853 			n = n->rb_left;
854 		else if (cmp > 0)
855 			n = n->rb_right;
856 		else
857 			return m;
858 	}
859 
860 	return NULL;
861 }
862 
863 static int __read_proc_modules(void *arg, const char *name, u64 start)
864 {
865 	struct rb_root *modules = arg;
866 	struct module_info *mi;
867 
868 	mi = zalloc(sizeof(struct module_info));
869 	if (!mi)
870 		return -ENOMEM;
871 
872 	mi->name = strdup(name);
873 	mi->start = start;
874 
875 	if (!mi->name) {
876 		free(mi);
877 		return -ENOMEM;
878 	}
879 
880 	add_module(mi, modules);
881 
882 	return 0;
883 }
884 
885 static int read_proc_modules(const char *filename, struct rb_root *modules)
886 {
887 	if (symbol__restricted_filename(filename, "/proc/modules"))
888 		return -1;
889 
890 	if (modules__parse(filename, modules, __read_proc_modules)) {
891 		delete_modules(modules);
892 		return -1;
893 	}
894 
895 	return 0;
896 }
897 
898 int compare_proc_modules(const char *from, const char *to)
899 {
900 	struct rb_root from_modules = RB_ROOT;
901 	struct rb_root to_modules = RB_ROOT;
902 	struct rb_node *from_node, *to_node;
903 	struct module_info *from_m, *to_m;
904 	int ret = -1;
905 
906 	if (read_proc_modules(from, &from_modules))
907 		return -1;
908 
909 	if (read_proc_modules(to, &to_modules))
910 		goto out_delete_from;
911 
912 	from_node = rb_first(&from_modules);
913 	to_node = rb_first(&to_modules);
914 	while (from_node) {
915 		if (!to_node)
916 			break;
917 
918 		from_m = rb_entry(from_node, struct module_info, rb_node);
919 		to_m = rb_entry(to_node, struct module_info, rb_node);
920 
921 		if (from_m->start != to_m->start ||
922 		    strcmp(from_m->name, to_m->name))
923 			break;
924 
925 		from_node = rb_next(from_node);
926 		to_node = rb_next(to_node);
927 	}
928 
929 	if (!from_node && !to_node)
930 		ret = 0;
931 
932 	delete_modules(&to_modules);
933 out_delete_from:
934 	delete_modules(&from_modules);
935 
936 	return ret;
937 }
938 
939 static int do_validate_kcore_modules(const char *filename, struct map *map,
940 				  struct map_groups *kmaps)
941 {
942 	struct rb_root modules = RB_ROOT;
943 	struct map *old_map;
944 	int err;
945 
946 	err = read_proc_modules(filename, &modules);
947 	if (err)
948 		return err;
949 
950 	old_map = map_groups__first(kmaps, map->type);
951 	while (old_map) {
952 		struct map *next = map_groups__next(old_map);
953 		struct module_info *mi;
954 
955 		if (old_map == map || old_map->start == map->start) {
956 			/* The kernel map */
957 			old_map = next;
958 			continue;
959 		}
960 
961 		/* Module must be in memory at the same address */
962 		mi = find_module(old_map->dso->short_name, &modules);
963 		if (!mi || mi->start != old_map->start) {
964 			err = -EINVAL;
965 			goto out;
966 		}
967 
968 		old_map = next;
969 	}
970 out:
971 	delete_modules(&modules);
972 	return err;
973 }
974 
975 /*
976  * If kallsyms is referenced by name then we look for filename in the same
977  * directory.
978  */
979 static bool filename_from_kallsyms_filename(char *filename,
980 					    const char *base_name,
981 					    const char *kallsyms_filename)
982 {
983 	char *name;
984 
985 	strcpy(filename, kallsyms_filename);
986 	name = strrchr(filename, '/');
987 	if (!name)
988 		return false;
989 
990 	name += 1;
991 
992 	if (!strcmp(name, "kallsyms")) {
993 		strcpy(name, base_name);
994 		return true;
995 	}
996 
997 	return false;
998 }
999 
1000 static int validate_kcore_modules(const char *kallsyms_filename,
1001 				  struct map *map)
1002 {
1003 	struct map_groups *kmaps = map__kmap(map)->kmaps;
1004 	char modules_filename[PATH_MAX];
1005 
1006 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1007 					     kallsyms_filename))
1008 		return -EINVAL;
1009 
1010 	if (do_validate_kcore_modules(modules_filename, map, kmaps))
1011 		return -EINVAL;
1012 
1013 	return 0;
1014 }
1015 
1016 struct kcore_mapfn_data {
1017 	struct dso *dso;
1018 	enum map_type type;
1019 	struct list_head maps;
1020 };
1021 
1022 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1023 {
1024 	struct kcore_mapfn_data *md = data;
1025 	struct map *map;
1026 
1027 	map = map__new2(start, md->dso, md->type);
1028 	if (map == NULL)
1029 		return -ENOMEM;
1030 
1031 	map->end = map->start + len;
1032 	map->pgoff = pgoff;
1033 
1034 	list_add(&map->node, &md->maps);
1035 
1036 	return 0;
1037 }
1038 
1039 static int dso__load_kcore(struct dso *dso, struct map *map,
1040 			   const char *kallsyms_filename)
1041 {
1042 	struct map_groups *kmaps = map__kmap(map)->kmaps;
1043 	struct machine *machine = kmaps->machine;
1044 	struct kcore_mapfn_data md;
1045 	struct map *old_map, *new_map, *replacement_map = NULL;
1046 	bool is_64_bit;
1047 	int err, fd;
1048 	char kcore_filename[PATH_MAX];
1049 	struct symbol *sym;
1050 
1051 	/* This function requires that the map is the kernel map */
1052 	if (map != machine->vmlinux_maps[map->type])
1053 		return -EINVAL;
1054 
1055 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1056 					     kallsyms_filename))
1057 		return -EINVAL;
1058 
1059 	/* All modules must be present at their original addresses */
1060 	if (validate_kcore_modules(kallsyms_filename, map))
1061 		return -EINVAL;
1062 
1063 	md.dso = dso;
1064 	md.type = map->type;
1065 	INIT_LIST_HEAD(&md.maps);
1066 
1067 	fd = open(kcore_filename, O_RDONLY);
1068 	if (fd < 0)
1069 		return -EINVAL;
1070 
1071 	/* Read new maps into temporary lists */
1072 	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1073 			      &is_64_bit);
1074 	if (err)
1075 		goto out_err;
1076 
1077 	if (list_empty(&md.maps)) {
1078 		err = -EINVAL;
1079 		goto out_err;
1080 	}
1081 
1082 	/* Remove old maps */
1083 	old_map = map_groups__first(kmaps, map->type);
1084 	while (old_map) {
1085 		struct map *next = map_groups__next(old_map);
1086 
1087 		if (old_map != map)
1088 			map_groups__remove(kmaps, old_map);
1089 		old_map = next;
1090 	}
1091 
1092 	/* Find the kernel map using the first symbol */
1093 	sym = dso__first_symbol(dso, map->type);
1094 	list_for_each_entry(new_map, &md.maps, node) {
1095 		if (sym && sym->start >= new_map->start &&
1096 		    sym->start < new_map->end) {
1097 			replacement_map = new_map;
1098 			break;
1099 		}
1100 	}
1101 
1102 	if (!replacement_map)
1103 		replacement_map = list_entry(md.maps.next, struct map, node);
1104 
1105 	/* Add new maps */
1106 	while (!list_empty(&md.maps)) {
1107 		new_map = list_entry(md.maps.next, struct map, node);
1108 		list_del(&new_map->node);
1109 		if (new_map == replacement_map) {
1110 			map->start	= new_map->start;
1111 			map->end	= new_map->end;
1112 			map->pgoff	= new_map->pgoff;
1113 			map->map_ip	= new_map->map_ip;
1114 			map->unmap_ip	= new_map->unmap_ip;
1115 			map__delete(new_map);
1116 			/* Ensure maps are correctly ordered */
1117 			map_groups__remove(kmaps, map);
1118 			map_groups__insert(kmaps, map);
1119 		} else {
1120 			map_groups__insert(kmaps, new_map);
1121 		}
1122 	}
1123 
1124 	/*
1125 	 * Set the data type and long name so that kcore can be read via
1126 	 * dso__data_read_addr().
1127 	 */
1128 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1129 		dso->data_type = DSO_BINARY_TYPE__GUEST_KCORE;
1130 	else
1131 		dso->data_type = DSO_BINARY_TYPE__KCORE;
1132 	dso__set_long_name(dso, strdup(kcore_filename));
1133 
1134 	close(fd);
1135 
1136 	if (map->type == MAP__FUNCTION)
1137 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1138 	else
1139 		pr_debug("Using %s for kernel data\n", kcore_filename);
1140 
1141 	return 0;
1142 
1143 out_err:
1144 	while (!list_empty(&md.maps)) {
1145 		map = list_entry(md.maps.next, struct map, node);
1146 		list_del(&map->node);
1147 		map__delete(map);
1148 	}
1149 	close(fd);
1150 	return -EINVAL;
1151 }
1152 
1153 int dso__load_kallsyms(struct dso *dso, const char *filename,
1154 		       struct map *map, symbol_filter_t filter)
1155 {
1156 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1157 		return -1;
1158 
1159 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1160 		return -1;
1161 
1162 	symbols__fixup_duplicate(&dso->symbols[map->type]);
1163 	symbols__fixup_end(&dso->symbols[map->type]);
1164 
1165 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1166 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1167 	else
1168 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1169 
1170 	if (!dso__load_kcore(dso, map, filename))
1171 		return dso__split_kallsyms_for_kcore(dso, map, filter);
1172 	else
1173 		return dso__split_kallsyms(dso, map, filter);
1174 }
1175 
1176 static int dso__load_perf_map(struct dso *dso, struct map *map,
1177 			      symbol_filter_t filter)
1178 {
1179 	char *line = NULL;
1180 	size_t n;
1181 	FILE *file;
1182 	int nr_syms = 0;
1183 
1184 	file = fopen(dso->long_name, "r");
1185 	if (file == NULL)
1186 		goto out_failure;
1187 
1188 	while (!feof(file)) {
1189 		u64 start, size;
1190 		struct symbol *sym;
1191 		int line_len, len;
1192 
1193 		line_len = getline(&line, &n, file);
1194 		if (line_len < 0)
1195 			break;
1196 
1197 		if (!line)
1198 			goto out_failure;
1199 
1200 		line[--line_len] = '\0'; /* \n */
1201 
1202 		len = hex2u64(line, &start);
1203 
1204 		len++;
1205 		if (len + 2 >= line_len)
1206 			continue;
1207 
1208 		len += hex2u64(line + len, &size);
1209 
1210 		len++;
1211 		if (len + 2 >= line_len)
1212 			continue;
1213 
1214 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1215 
1216 		if (sym == NULL)
1217 			goto out_delete_line;
1218 
1219 		if (filter && filter(map, sym))
1220 			symbol__delete(sym);
1221 		else {
1222 			symbols__insert(&dso->symbols[map->type], sym);
1223 			nr_syms++;
1224 		}
1225 	}
1226 
1227 	free(line);
1228 	fclose(file);
1229 
1230 	return nr_syms;
1231 
1232 out_delete_line:
1233 	free(line);
1234 out_failure:
1235 	return -1;
1236 }
1237 
1238 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1239 {
1240 	char *name;
1241 	int ret = -1;
1242 	u_int i;
1243 	struct machine *machine;
1244 	char *root_dir = (char *) "";
1245 	int ss_pos = 0;
1246 	struct symsrc ss_[2];
1247 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1248 
1249 	dso__set_loaded(dso, map->type);
1250 
1251 	if (dso->kernel == DSO_TYPE_KERNEL)
1252 		return dso__load_kernel_sym(dso, map, filter);
1253 	else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1254 		return dso__load_guest_kernel_sym(dso, map, filter);
1255 
1256 	if (map->groups && map->groups->machine)
1257 		machine = map->groups->machine;
1258 	else
1259 		machine = NULL;
1260 
1261 	dso->adjust_symbols = 0;
1262 
1263 	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1264 		struct stat st;
1265 
1266 		if (lstat(dso->name, &st) < 0)
1267 			return -1;
1268 
1269 		if (st.st_uid && (st.st_uid != geteuid())) {
1270 			pr_warning("File %s not owned by current user or root, "
1271 				"ignoring it.\n", dso->name);
1272 			return -1;
1273 		}
1274 
1275 		ret = dso__load_perf_map(dso, map, filter);
1276 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1277 					     DSO_BINARY_TYPE__NOT_FOUND;
1278 		return ret;
1279 	}
1280 
1281 	if (machine)
1282 		root_dir = machine->root_dir;
1283 
1284 	name = malloc(PATH_MAX);
1285 	if (!name)
1286 		return -1;
1287 
1288 	/* Iterate over candidate debug images.
1289 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1290 	 * and/or opd section) for processing.
1291 	 */
1292 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1293 		struct symsrc *ss = &ss_[ss_pos];
1294 		bool next_slot = false;
1295 
1296 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1297 
1298 		if (dso__binary_type_file(dso, symtab_type,
1299 					  root_dir, name, PATH_MAX))
1300 			continue;
1301 
1302 		/* Name is now the name of the next image to try */
1303 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1304 			continue;
1305 
1306 		if (!syms_ss && symsrc__has_symtab(ss)) {
1307 			syms_ss = ss;
1308 			next_slot = true;
1309 		}
1310 
1311 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1312 			runtime_ss = ss;
1313 			next_slot = true;
1314 		}
1315 
1316 		if (next_slot) {
1317 			ss_pos++;
1318 
1319 			if (syms_ss && runtime_ss)
1320 				break;
1321 		}
1322 
1323 	}
1324 
1325 	if (!runtime_ss && !syms_ss)
1326 		goto out_free;
1327 
1328 	if (runtime_ss && !syms_ss) {
1329 		syms_ss = runtime_ss;
1330 	}
1331 
1332 	/* We'll have to hope for the best */
1333 	if (!runtime_ss && syms_ss)
1334 		runtime_ss = syms_ss;
1335 
1336 	if (syms_ss) {
1337 		int km;
1338 
1339 		km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1340 		     dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
1341 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
1342 	} else {
1343 		ret = -1;
1344 	}
1345 
1346 	if (ret > 0) {
1347 		int nr_plt;
1348 
1349 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1350 		if (nr_plt > 0)
1351 			ret += nr_plt;
1352 	}
1353 
1354 	for (; ss_pos > 0; ss_pos--)
1355 		symsrc__destroy(&ss_[ss_pos - 1]);
1356 out_free:
1357 	free(name);
1358 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1359 		return 0;
1360 	return ret;
1361 }
1362 
1363 struct map *map_groups__find_by_name(struct map_groups *mg,
1364 				     enum map_type type, const char *name)
1365 {
1366 	struct rb_node *nd;
1367 
1368 	for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1369 		struct map *map = rb_entry(nd, struct map, rb_node);
1370 
1371 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1372 			return map;
1373 	}
1374 
1375 	return NULL;
1376 }
1377 
1378 int dso__load_vmlinux(struct dso *dso, struct map *map,
1379 		      const char *vmlinux, symbol_filter_t filter)
1380 {
1381 	int err = -1;
1382 	struct symsrc ss;
1383 	char symfs_vmlinux[PATH_MAX];
1384 	enum dso_binary_type symtab_type;
1385 
1386 	if (vmlinux[0] == '/')
1387 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1388 	else
1389 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1390 			 symbol_conf.symfs, vmlinux);
1391 
1392 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1393 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1394 	else
1395 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1396 
1397 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1398 		return -1;
1399 
1400 	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1401 	symsrc__destroy(&ss);
1402 
1403 	if (err > 0) {
1404 		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1405 			dso->data_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1406 		else
1407 			dso->data_type = DSO_BINARY_TYPE__VMLINUX;
1408 		dso__set_long_name(dso, (char *)vmlinux);
1409 		dso__set_loaded(dso, map->type);
1410 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1411 	}
1412 
1413 	return err;
1414 }
1415 
1416 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1417 			   symbol_filter_t filter)
1418 {
1419 	int i, err = 0;
1420 	char *filename;
1421 
1422 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1423 		 vmlinux_path__nr_entries + 1);
1424 
1425 	filename = dso__build_id_filename(dso, NULL, 0);
1426 	if (filename != NULL) {
1427 		err = dso__load_vmlinux(dso, map, filename, filter);
1428 		if (err > 0) {
1429 			dso->lname_alloc = 1;
1430 			goto out;
1431 		}
1432 		free(filename);
1433 	}
1434 
1435 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1436 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
1437 		if (err > 0) {
1438 			dso__set_long_name(dso, strdup(vmlinux_path[i]));
1439 			dso->lname_alloc = 1;
1440 			break;
1441 		}
1442 	}
1443 out:
1444 	return err;
1445 }
1446 
1447 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1448 {
1449 	char kallsyms_filename[PATH_MAX];
1450 	struct dirent *dent;
1451 	int ret = -1;
1452 	DIR *d;
1453 
1454 	d = opendir(dir);
1455 	if (!d)
1456 		return -1;
1457 
1458 	while (1) {
1459 		dent = readdir(d);
1460 		if (!dent)
1461 			break;
1462 		if (dent->d_type != DT_DIR)
1463 			continue;
1464 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1465 			  "%s/%s/kallsyms", dir, dent->d_name);
1466 		if (!validate_kcore_modules(kallsyms_filename, map)) {
1467 			strlcpy(dir, kallsyms_filename, dir_sz);
1468 			ret = 0;
1469 			break;
1470 		}
1471 	}
1472 
1473 	closedir(d);
1474 
1475 	return ret;
1476 }
1477 
1478 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1479 {
1480 	u8 host_build_id[BUILD_ID_SIZE];
1481 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1482 	bool is_host = false;
1483 	char path[PATH_MAX];
1484 
1485 	if (!dso->has_build_id) {
1486 		/*
1487 		 * Last resort, if we don't have a build-id and couldn't find
1488 		 * any vmlinux file, try the running kernel kallsyms table.
1489 		 */
1490 		goto proc_kallsyms;
1491 	}
1492 
1493 	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1494 				 sizeof(host_build_id)) == 0)
1495 		is_host = dso__build_id_equal(dso, host_build_id);
1496 
1497 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1498 
1499 	/* Use /proc/kallsyms if possible */
1500 	if (is_host) {
1501 		DIR *d;
1502 		int fd;
1503 
1504 		/* If no cached kcore go with /proc/kallsyms */
1505 		scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s",
1506 			  buildid_dir, sbuild_id);
1507 		d = opendir(path);
1508 		if (!d)
1509 			goto proc_kallsyms;
1510 		closedir(d);
1511 
1512 		/*
1513 		 * Do not check the build-id cache, until we know we cannot use
1514 		 * /proc/kcore.
1515 		 */
1516 		fd = open("/proc/kcore", O_RDONLY);
1517 		if (fd != -1) {
1518 			close(fd);
1519 			/* If module maps match go with /proc/kallsyms */
1520 			if (!validate_kcore_modules("/proc/kallsyms", map))
1521 				goto proc_kallsyms;
1522 		}
1523 
1524 		/* Find kallsyms in build-id cache with kcore */
1525 		if (!find_matching_kcore(map, path, sizeof(path)))
1526 			return strdup(path);
1527 
1528 		goto proc_kallsyms;
1529 	}
1530 
1531 	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1532 		  buildid_dir, sbuild_id);
1533 
1534 	if (access(path, F_OK)) {
1535 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1536 		       sbuild_id);
1537 		return NULL;
1538 	}
1539 
1540 	return strdup(path);
1541 
1542 proc_kallsyms:
1543 	return strdup("/proc/kallsyms");
1544 }
1545 
1546 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1547 				symbol_filter_t filter)
1548 {
1549 	int err;
1550 	const char *kallsyms_filename = NULL;
1551 	char *kallsyms_allocated_filename = NULL;
1552 	/*
1553 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1554 	 * it and only it, reporting errors to the user if it cannot be used.
1555 	 *
1556 	 * For instance, try to analyse an ARM perf.data file _without_ a
1557 	 * build-id, or if the user specifies the wrong path to the right
1558 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1559 	 * x86_86 one, on the machine where analysis is being performed, say),
1560 	 * or worse, /proc/kallsyms.
1561 	 *
1562 	 * If the specified file _has_ a build-id and there is a build-id
1563 	 * section in the perf.data file, we will still do the expected
1564 	 * validation in dso__load_vmlinux and will bail out if they don't
1565 	 * match.
1566 	 */
1567 	if (symbol_conf.kallsyms_name != NULL) {
1568 		kallsyms_filename = symbol_conf.kallsyms_name;
1569 		goto do_kallsyms;
1570 	}
1571 
1572 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1573 		err = dso__load_vmlinux(dso, map,
1574 					symbol_conf.vmlinux_name, filter);
1575 		if (err > 0) {
1576 			dso__set_long_name(dso,
1577 					   strdup(symbol_conf.vmlinux_name));
1578 			dso->lname_alloc = 1;
1579 			return err;
1580 		}
1581 		return err;
1582 	}
1583 
1584 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1585 		err = dso__load_vmlinux_path(dso, map, filter);
1586 		if (err > 0)
1587 			return err;
1588 	}
1589 
1590 	/* do not try local files if a symfs was given */
1591 	if (symbol_conf.symfs[0] != 0)
1592 		return -1;
1593 
1594 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1595 	if (!kallsyms_allocated_filename)
1596 		return -1;
1597 
1598 	kallsyms_filename = kallsyms_allocated_filename;
1599 
1600 do_kallsyms:
1601 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1602 	if (err > 0)
1603 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1604 	free(kallsyms_allocated_filename);
1605 
1606 	if (err > 0 && !dso__is_kcore(dso)) {
1607 		dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1608 		map__fixup_start(map);
1609 		map__fixup_end(map);
1610 	}
1611 
1612 	return err;
1613 }
1614 
1615 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1616 				      symbol_filter_t filter)
1617 {
1618 	int err;
1619 	const char *kallsyms_filename = NULL;
1620 	struct machine *machine;
1621 	char path[PATH_MAX];
1622 
1623 	if (!map->groups) {
1624 		pr_debug("Guest kernel map hasn't the point to groups\n");
1625 		return -1;
1626 	}
1627 	machine = map->groups->machine;
1628 
1629 	if (machine__is_default_guest(machine)) {
1630 		/*
1631 		 * if the user specified a vmlinux filename, use it and only
1632 		 * it, reporting errors to the user if it cannot be used.
1633 		 * Or use file guest_kallsyms inputted by user on commandline
1634 		 */
1635 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1636 			err = dso__load_vmlinux(dso, map,
1637 				symbol_conf.default_guest_vmlinux_name, filter);
1638 			return err;
1639 		}
1640 
1641 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
1642 		if (!kallsyms_filename)
1643 			return -1;
1644 	} else {
1645 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1646 		kallsyms_filename = path;
1647 	}
1648 
1649 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1650 	if (err > 0)
1651 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1652 	if (err > 0 && !dso__is_kcore(dso)) {
1653 		machine__mmap_name(machine, path, sizeof(path));
1654 		dso__set_long_name(dso, strdup(path));
1655 		map__fixup_start(map);
1656 		map__fixup_end(map);
1657 	}
1658 
1659 	return err;
1660 }
1661 
1662 static void vmlinux_path__exit(void)
1663 {
1664 	while (--vmlinux_path__nr_entries >= 0) {
1665 		free(vmlinux_path[vmlinux_path__nr_entries]);
1666 		vmlinux_path[vmlinux_path__nr_entries] = NULL;
1667 	}
1668 
1669 	free(vmlinux_path);
1670 	vmlinux_path = NULL;
1671 }
1672 
1673 static int vmlinux_path__init(void)
1674 {
1675 	struct utsname uts;
1676 	char bf[PATH_MAX];
1677 
1678 	vmlinux_path = malloc(sizeof(char *) * 5);
1679 	if (vmlinux_path == NULL)
1680 		return -1;
1681 
1682 	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1683 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1684 		goto out_fail;
1685 	++vmlinux_path__nr_entries;
1686 	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1687 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1688 		goto out_fail;
1689 	++vmlinux_path__nr_entries;
1690 
1691 	/* only try running kernel version if no symfs was given */
1692 	if (symbol_conf.symfs[0] != 0)
1693 		return 0;
1694 
1695 	if (uname(&uts) < 0)
1696 		return -1;
1697 
1698 	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1699 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1700 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1701 		goto out_fail;
1702 	++vmlinux_path__nr_entries;
1703 	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1704 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1705 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1706 		goto out_fail;
1707 	++vmlinux_path__nr_entries;
1708 	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1709 		 uts.release);
1710 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1711 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1712 		goto out_fail;
1713 	++vmlinux_path__nr_entries;
1714 
1715 	return 0;
1716 
1717 out_fail:
1718 	vmlinux_path__exit();
1719 	return -1;
1720 }
1721 
1722 static int setup_list(struct strlist **list, const char *list_str,
1723 		      const char *list_name)
1724 {
1725 	if (list_str == NULL)
1726 		return 0;
1727 
1728 	*list = strlist__new(true, list_str);
1729 	if (!*list) {
1730 		pr_err("problems parsing %s list\n", list_name);
1731 		return -1;
1732 	}
1733 	return 0;
1734 }
1735 
1736 static bool symbol__read_kptr_restrict(void)
1737 {
1738 	bool value = false;
1739 
1740 	if (geteuid() != 0) {
1741 		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1742 		if (fp != NULL) {
1743 			char line[8];
1744 
1745 			if (fgets(line, sizeof(line), fp) != NULL)
1746 				value = atoi(line) != 0;
1747 
1748 			fclose(fp);
1749 		}
1750 	}
1751 
1752 	return value;
1753 }
1754 
1755 int symbol__init(void)
1756 {
1757 	const char *symfs;
1758 
1759 	if (symbol_conf.initialized)
1760 		return 0;
1761 
1762 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1763 
1764 	symbol__elf_init();
1765 
1766 	if (symbol_conf.sort_by_name)
1767 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1768 					  sizeof(struct symbol));
1769 
1770 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1771 		return -1;
1772 
1773 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1774 		pr_err("'.' is the only non valid --field-separator argument\n");
1775 		return -1;
1776 	}
1777 
1778 	if (setup_list(&symbol_conf.dso_list,
1779 		       symbol_conf.dso_list_str, "dso") < 0)
1780 		return -1;
1781 
1782 	if (setup_list(&symbol_conf.comm_list,
1783 		       symbol_conf.comm_list_str, "comm") < 0)
1784 		goto out_free_dso_list;
1785 
1786 	if (setup_list(&symbol_conf.sym_list,
1787 		       symbol_conf.sym_list_str, "symbol") < 0)
1788 		goto out_free_comm_list;
1789 
1790 	/*
1791 	 * A path to symbols of "/" is identical to ""
1792 	 * reset here for simplicity.
1793 	 */
1794 	symfs = realpath(symbol_conf.symfs, NULL);
1795 	if (symfs == NULL)
1796 		symfs = symbol_conf.symfs;
1797 	if (strcmp(symfs, "/") == 0)
1798 		symbol_conf.symfs = "";
1799 	if (symfs != symbol_conf.symfs)
1800 		free((void *)symfs);
1801 
1802 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1803 
1804 	symbol_conf.initialized = true;
1805 	return 0;
1806 
1807 out_free_comm_list:
1808 	strlist__delete(symbol_conf.comm_list);
1809 out_free_dso_list:
1810 	strlist__delete(symbol_conf.dso_list);
1811 	return -1;
1812 }
1813 
1814 void symbol__exit(void)
1815 {
1816 	if (!symbol_conf.initialized)
1817 		return;
1818 	strlist__delete(symbol_conf.sym_list);
1819 	strlist__delete(symbol_conf.dso_list);
1820 	strlist__delete(symbol_conf.comm_list);
1821 	vmlinux_path__exit();
1822 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1823 	symbol_conf.initialized = false;
1824 }
1825